WorldWideScience

Sample records for chemical stimulation techniques

  1. Chemical stimulation techniques for geothermal wells: experiments on the three-well EGS system at Soultz-sous-Forêts, France

    OpenAIRE

    Portier, Sandrine; Vuataz, François-David; Nami, Patrick; Sanjuan, Bernard; Gérard, André

    2012-01-01

    Rock matrix stimulation is a method of enhancing well production or injection within a broad range of challenging environments, varying from naturally fractured limestones to sandstones with complex mineralogy. A common and often successful stimulation option, matrix acidizing, utilizes acids that react and remove mineral phases restricting fluid flow. Reviewed is the technology of chemical treatments available for oil, gas and geothermal wells and the key elements and results of the chemical...

  2. Thermoluminescent dosimetry and of optically stimulated luminescence of diamond films grown up by the chemical vapor deposition technique exposed to beta radiation

    International Nuclear Information System (INIS)

    Melendrez A, R.; Barboza F, M.

    2002-01-01

    A study of the dosimetric properties through the thermoluminescence (Tl) and Optically stimulated luminescence (Lobe) in diamond films grown up by the chemical vapor deposition (Dq) techniques was realized.The films under study have thickness of 6, 12, 180 and 500 microns. The dose range was from 0 to 1.5 KGy, observing for the case of the thermoluminescent dosimetry a linear behavior in the range 0-300 Gy and a supra linearity effect in the range from 300-1500 Gy. For the case of the dosimetry by means of LOE a linear behavior in the range (0-300 Gy) without be enough for the saturation was observed, although some samples exhibit a linear behavior until 1500 Gy (6 microns). The irradiation was realized with a source of Strontium 90 of (40 mCi) and the photoestimulation for realizing the measures of LOE was realized using diodes emitting of laser light (470 nm) which generate until 50 MW/cm 2 . The Tl peak which was used to realize the dosimetry such Tl as LOE was that located around 340 C degrees in the brilliance curve which presents another peaks centered around of 110, 190, and 340 C degrees, depending on the film. It was realized a study of the Tl signal drop and it was observed that after 3 hours the signal was stable reaching a decay of 15 %. the analysis of the drop in the Tl signal, immediately after to irradiate and after to photoestimulate with the blue light laser for observing the LOE, indicated that exists a fall in all the Tl peaks, decaying in greater proportion those of more low temperature. (Author)

  3. Chemical Stimulation of Engineered Geothermal Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rose, Peter, E.

    2008-08-08

    The objective of this project is to design, develop and demonstrate methods for the chemical stimulation of candidate EGS reservoirs as well as the chemical treatment of mineral-scaled wellbores. First, a set of candidate chemical compounds capable of dissolving calcite was identified. A series of tests was then performed on each candidate in order to screen it for thermal stability and reactivity towards calcite. A detailed analysis was then performed on each compound that emerged from the screening tests in order to characterize its decay kinetics and reaction kinetics as functions of temperature and chemical composition. From among the compounds emerging from the laboratory studies, one compounds was chosen for a field experiment in order to verify the laboratory predictions.

  4. Transcranial magnetic stimulation techniques in clinical investigation.

    Science.gov (United States)

    Currà, A; Modugno, N; Inghilleri, M; Manfredi, M; Hallett, M; Berardelli, A

    2002-12-24

    Transcranial magnetic stimulation (TMS) is a technique that can activate cortical motor areas and the corticospinal tract without causing the subject discomfort. Since TMS was introduced, numerous applications of the technique have been developed for the evaluation of neurologic diseases. Standard TMS applications (central motor conduction time, threshold and amplitude of motor evoked potentials) allow the evaluation of motor conduction in the CNS. Conduction studies provide specific information in neurologic conditions characterized by clinical and subclinical upper motor neuron involvement. In addition, they have proved useful in monitoring motor abnormalities and the recovery of motor function. TMS also gives information on the pathophysiology of the processes underlying the various clinical conditions. More complex TMS applications (paired-pulse stimulation, silent period, ipsilateral silent period, input-output curve, and evaluation of central fatigue) allow investigation into the mechanisms of diseases causing changes in the excitability of cortical motor areas. These techniques are also useful in monitoring the effects of neurotrophic drugs on cortical activity. TMS applications have an important place among the investigative tools to study patients with motor disorders.

  5. Metallic taste from electrical and chemical stimulation.

    Science.gov (United States)

    Lawless, Harry T; Stevens, David A; Chapman, Kathryn W; Kurtz, Anne

    2005-03-01

    A series of three experiments investigated the nature of metallic taste reports after stimulation with solutions of metal salts and after stimulation with metals and electric currents. To stimulate with electricity, a device was fabricated consisting of a small battery affixed to a plastic handle with the anode side exposed for placement on the tongue or oral tissues. Intensity of taste from metals and batteries was dependent upon the voltage and was more robust in areas dense in fungiform papillae. Metallic taste was reported from stimulation with ferrous sulfate solutions, from metals and from electric stimuli. However, reports of metallic taste were more frequent when the word 'metallic' was presented embedded in a list of choices, as opposed to simple free-choice labeling. Intensity decreased for ferrous sulfate when the nose was occluded, consistent with a decrease in retronasal smell, as previously reported. Intensity of taste evoked by copper metal, bimetallic stimuli (zinc/copper) or small batteries (1.5-3 V) was not affected by nasal occlusion. This difference suggests two distinct mechanisms for evocation of metallic taste reports, one dependent upon retronasal smell and a second mediated by oral chemoreceptors.

  6. Chemical analysis by nuclear techniques

    International Nuclear Information System (INIS)

    Sohn, S. C.; Kim, W. H.; Park, Y. J.; Park, Y. J.; Song, B. C.; Jeon, Y. S.; Jee, K. Y.; Pyo, H. Y.

    2002-01-01

    This state art report consists of four parts, production of micro-particles, analysis of boron, alpha tracking method and development of neutron induced prompt gamma ray spectroscopy (NIPS) system. The various methods for the production of micro-paticles such as mechanical method, electrolysis method, chemical method, spray method were described in the first part. The second part contains sample treatment, separation and concentration, analytical method, and application of boron analysis. The third part contains characteristics of alpha track, track dectectors, pretreatment of sample, neutron irradiation, etching conditions for various detectors, observation of track on the detector, etc. The last part contains basic theory, neutron source, collimator, neutron shields, calibration of NIPS, and application of NIPS system

  7. Chemical analysis by nuclear techniques

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, S. C.; Kim, W. H.; Park, Y. J.; Song, B. C.; Jeon, Y. S.; Jee, K. Y.; Pyo, H. Y

    2002-01-01

    This state art report consists of four parts, production of micro-particles, analysis of boron, alpha tracking method and development of neutron induced prompt gamma ray spectroscopy (NIPS) system. The various methods for the production of micro-paticles such as mechanical method, electrolysis method, chemical method, spray method were described in the first part. The second part contains sample treatment, separation and concentration, analytical method, and application of boron analysis. The third part contains characteristics of alpha track, track dectectors, pretreatment of sample, neutron irradiation, etching conditions for various detectors, observation of track on the detector, etc. The last part contains basic theory, neutron source, collimator, neutron shields, calibration of NIPS, and application of NIPS system.

  8. Nuclear techniques in coal and chemical industries

    International Nuclear Information System (INIS)

    Elbern, A.W.; Leal, C.A.

    1980-01-01

    The use of nuclear techniques for the determination of important parameters in industrial installations is exemplified; advantages of these techniques over other methods conventionally used are pointed out. The use of radiotracers in the study of physical and chemical phenomena occurring in the chemical industry is discussed. It is also shown that, using certain radioisotopes, it is possible to construct devices which enable, for example, the determination of the ash content in coal samples. These devices are economical and easy to be installed for the on-line control during coal transportation. (C.L.B.) [pt

  9. Hybrid chemical and nondestructive-analysis technique

    International Nuclear Information System (INIS)

    Hsue, S.T.; Marsh, S.F.; Marks, T.

    1982-01-01

    A hybrid chemical/NDA technique has been applied at the Los Alamos National Laboratory to the assay of plutonium in ion-exchange effluents. Typical effluent solutions contain low concentrations of plutonium and high concentrations of americium. A simple trioctylphosphine oxide (TOPO) separation can remove 99.9% of the americium. The organic phase that contains the separated plutonium can be accurately assayed by monitoring the uranium L x-ray intensities

  10. Technical review of the high energy gas stimulation technique

    Energy Technology Data Exchange (ETDEWEB)

    Haney, B.; Cuthill, D. [Computalog Ltd., Calgary, AB (Canada)

    1997-08-01

    High Energy Gas Stimulation (HEGS) or propellant stimulation is a process that enhances production of oil wells by decreasing wellbore damage and increasing near wellbore permeability. The technique has been used on about 7,000 wells with varying results. The HEGS tool is a cast cylinder of solid rocket propellant with a central ignition system. The propellant is fired and as it burns it produces a pressure load on the formation, increasing fracture volume which enhances the flow channels. Background information on the development and application of this stimulation technique was provided. The introduction of fractures around a wellbore is dependent on the pressure loading rate and the dynamic response of the rock. Propellant stimulation relies on controlling the pressure-time behaviour to maximize fracture growth by fluid pressurization. The process is composed of 3 sequential phases: (1) wellbore pressurization, (2) fracture initiation, and (3) fracture extension. A full description of each of these phases was provided. Geologic and well-tool factors that have a significant influence on the fracturing process such as in-situ stress, natural fractures and flaws, formation mechanical properties, formation fluid and flow properties, formation thermal properties, and wellbore, tool, and tamp configuration, were also reviewed. The many applications for HEGS were presented. It was emphasized that the success of HEGS is dependent on pre-stimulation problem evaluation and on proper charge design. Since HEGS will decrease near-wellbore restrictions and initiate formation breakdown, it should only be used in cases where this will be beneficial to the well. Careful attention to engineering will optimize results. 21 refs., 13 figs.

  11. Optically stimulated luminescence from quartz measured using the linear modulation technique

    DEFF Research Database (Denmark)

    Bulur, E.; Bøtter-Jensen, L.; Murray, A.S.

    2000-01-01

    The optically stimulated luminescence (OSL) from heated natural quartz has been investigated using the linear modulation technique (LMT), in which the excitation light intensity is increased linearly during stimulation. In contrast to conventional stimulation, which usually produces a monotonical...

  12. Bubble Jet agent release cartridge for chemical single cell stimulation.

    Science.gov (United States)

    Wangler, N; Welsche, M; Blazek, M; Blessing, M; Vervliet-Scheebaum, M; Reski, R; Müller, C; Reinecke, H; Steigert, J; Roth, G; Zengerle, R; Paust, N

    2013-02-01

    We present a new method for the distinct specific chemical stimulation of single cells and small cell clusters within their natural environment. By single-drop release of chemical agents with droplets in size of typical cell diameters (d agent release cartridge with integrated fluidic structures and integrated agent reservoirs are shown, tested, and compared in this publication. The single channel setup features a fluidic structure fabricated by anisotropic etching of silicon. To allow for simultaneous release of different agents even though maintaining the same device size, the second type comprises a double channel fluidic structure, fabricated by photolithographic patterning of TMMF. Dispensed droplet volumes are V = 15 pl and V = 10 pl for the silicon and the TMMF based setups, respectively. Utilizing the agent release cartridges, the application in biological assays was demonstrated by hormone-stimulated premature bud formation in Physcomitrella patens and the individual staining of one single L 929 cell within a confluent grown cell culture.

  13. Identifying irradiated flour by photo-stimulated luminescence technique

    International Nuclear Information System (INIS)

    Ros Anita Ahmad Ramli; Muhammad Samudi Yasir; Zainon Othman; Wan Saffiey Wan Abdullah

    2013-01-01

    Full-text: The photo-stimulated luminescence technique is recommended by European Committee for standardization for the detection food irradiation (EN 13751:2009). This study shows on luminescence technique to identify gamma irradiated five types of flour (corn flour, tapioca flour, wheat flour, glutinos rice flour and rice flour) at three difference dose levels in the range 0.2 - 1 kGy. The signal level is compare with two thresholds (700 and 5000). The majority of irradiated samples produce a strong signal above the upper threshold (5000 counts/ 60 s). All the control samples gave negative screening result while the signals below the lower threshold (700 counts/ 60s) suggest that the sample has not been irradiated. A few samples show the signal levels between the two thresholds (intermediate signals) suggest that further investigation. Reported procedure was also tested over 60 days, confirming the applicability and feasibility of proposed methods. (author)

  14. Development of photo stimulated luminescence technique for detecting irradiated food

    International Nuclear Information System (INIS)

    Ros Anita Ahmad Ramli; Ahmad Zainuri Mohd Dzomir; Zainon Othman; Wan Saffiey Wan Abdullah

    2012-01-01

    The exposure of food to ionizing radiation is being progressively used in many countries to inactivate food pathogens, to eradicate pests and to extend shelf-life of food. To ensure free consumer choice, irradiated food will be labeled. The availability of a reliable method to detect irradiated food is important to enforce legal controls on labeling requirements, ensure proper distribution and increase consumer confidence. This paper reports on the preliminary application of photo stimulated luminescence technique (PSL) as a potential method to detect irradiated food and perhaps be used for monitoring irradiated food on sale locally in the near future. Thus this study will be beneficial and relevant for application of food irradiation towards improving food safety and security in Malaysia. (author)

  15. Identifying irradiated flours by photo-stimulated luminescence technique

    Energy Technology Data Exchange (ETDEWEB)

    Ramli, Ros Anita Ahmad; Yasir, Muhamad Samudi [Faculty of Science and Technology, National University of Malaysia, Bangi, 43000 Kajang, Selangor (Malaysia); Othman, Zainon; Abdullah, Wan Saffiey Wan [Malaysian Nuclear Agency, Bangi 43000 Kajang, Selangor (Malaysia)

    2014-02-12

    Photo-stimulated luminescence (PSL) technique was used in this study to detect gamma irradiation treatment of five types of flours (corn, rice, tapioca, wheat and glutinous rice) at four different doses 0, 0.2, .05 and 1kGy. The signal level was compared with two threshold values (700 and 5000). With the exception of glutinous rice, all irradiated samples produced a strong signal above the upper threshold (5000 counts/60s). All control samples produced negative result with the signals below the lower threshold (700 counts/60s) suggesting that the samples have not been irradiated. Irradiated glutinous rice samples produced intermediate signals (700 - 5000 counts/60s) which were subsequently confirmed using calibrated PSL. The PSL signals remained stable after 90 days of storage. The findings of this study will be useful to facilitate control of food irradiation application in Malaysia.

  16. Identifying irradiated flours by photo-stimulated luminescence technique

    International Nuclear Information System (INIS)

    Ramli, Ros Anita Ahmad; Yasir, Muhamad Samudi; Othman, Zainon; Abdullah, Wan Saffiey Wan

    2014-01-01

    Photo-stimulated luminescence (PSL) technique was used in this study to detect gamma irradiation treatment of five types of flours (corn, rice, tapioca, wheat and glutinous rice) at four different doses 0, 0.2, .05 and 1kGy. The signal level was compared with two threshold values (700 and 5000). With the exception of glutinous rice, all irradiated samples produced a strong signal above the upper threshold (5000 counts/60s). All control samples produced negative result with the signals below the lower threshold (700 counts/60s) suggesting that the samples have not been irradiated. Irradiated glutinous rice samples produced intermediate signals (700 - 5000 counts/60s) which were subsequently confirmed using calibrated PSL. The PSL signals remained stable after 90 days of storage. The findings of this study will be useful to facilitate control of food irradiation application in Malaysia

  17. Superconducting lead particles produced by chemical techniques

    Science.gov (United States)

    Fariss, T. L.; Nixon, W. E.; Bucelot, T. J.; Deaver, B. S., Jr.; Mitchell, J. W.

    1982-09-01

    The superconductivity of extremely small lead particles has been studied as a function of size, surface condition, and connectivity using chemical techniques to produce particles of well-controlled size and shape suspended in insulating media. Approximately monodisperse suspensions of equiaxed, rod, and lath-shaped particles of lead halides and other lead compounds suspended in gelatin, polyacrylamide, polyvinylpyrrolidone, polyvinyl alcohol, methyl cellulose, and hydroxyethyl cellulose have been produced. These particles have been reduced to pseudomorphs of lead in the liquid phase or the suspensions have been coated on substrates and dried before reduction. Reducing solutions containing aminoiminomethanesulfinic acid are effective with particles of lead halides, lead phosphate, lead sulfate, and lead tartrate. Suspensions of smaller discrete lead particles have also been produced by direct reduction of solutions of soluble lead salts containing suitable polymers, chelating, and stabilizing agents. Dispersions with mean particle dimensions between 3 nm and 5 μm, and a narrow size-frequency distribution, have been produced. The superconductivity of the particles has been characterized by measurements of the magnetization as a function of temperature and magnetic field. The larger particles have a transition temperature of 7.2 K, the same as bulk lead; however, for particles of characteristic dimensions less than 20 nm, the transition temperature is lower by ˜0.1 K.

  18. Superconducting lead particles produced by chemical techniques

    International Nuclear Information System (INIS)

    Fariss, T.L.; Nixon, W.E.; Bucelot, T.J.; Deaver, B.S. Jr.; Mitchell, J.W.

    1982-01-01

    The superconductivity of extremely small lead particles has been studied as a function of size, surface condition, and connectivity using chemical techniques to produce particles of well-controlled size and shape suspended in insulating media. Approximately monodisperse suspensions of equiaxed, rod, and lath-shaped particles of lead halides and other lead compounds suspended in gelatin, polyacrylamide, polyvinylpyrrolidone, polyvinyl alcohol, methyl cellulose, and hydroxyethyl cellulose have been produced. These particles have been reduced to pseudomorphs of lead in the liquid phase or the suspensions have been coated on substrates and dried before reduction. Reducing solutions containing aminoiminomethanesulfinic acid are effective with particles of lead halides, lead phosphate, lead sulfate, and lead tartrate. Suspensions of smaller discrete lead particles have also been produced by direct reduction of solutions of soluble lead salts containing suitable polymers, chelating, and stabilizing agents. Dispersions with mean particle dimensions between 3 nm and 5 μm, and a narrow size-frequency distribution, have been produced. The superconductivity of the particles has been characterized by measurements of the magnetization as a function of temperature and magnetic field. The larger particles have a transition temperature of 7.2 K, the same as bulk lead; however, for particles of characteristic dimensions less than 20 nm, the transition temperature is lower by approx.0.1 K

  19. Construction technique for a chemical plant (I)

    International Nuclear Information System (INIS)

    1978-08-01

    This book mentions the order of plant construction, building plant and related regulations, basic engineering design data, provide of equipment, plan and management on building plant, quality control, the budget and contract for building plant, public works for building chemical plant like road construction, basic plan and building for a chemical plant, introduction and principle on foundation improvement method, including pile foundation and design for footing, construction and installation for a chemical plant and a rotary machine for a chemical plant.

  20. Construction technique for a chemical plant (III)

    International Nuclear Information System (INIS)

    1978-08-01

    This book mentions design of instrumentation and construction for a chemical plant, which deals with the change of instrumentation, construction, choice of material test, construction of thermal insulation work for a chemical plant, about classification and main materials, the problems on construction, painting plan and construction for a chemical plant such as paint and painting, safety and hygiene, cleaning of a chemical plant on the time for washing and decision of the way of washing, start up test for a chemical plant such as introduction of the check, construction and repair.

  1. Construction technique for a chemical plant (II)

    International Nuclear Information System (INIS)

    1978-08-01

    This book deals with design and construction for a chemical plant which includes design and building of steel structure for a chemical plant with types, basic regulation, plan, shop fabrication for steel structure and field construction. It explains design and construction of making building for a chemical construction with measurement, types of building and basic rule of the building, design of the building, constructing plumbing for a chemical plant with plan, management of material, checking for construction, construction of electrical installation on plan, know-how to construction and maintenance.

  2. Chemical stimulation in unconventional hydrocarbons extraction in the USA: a preliminary environmental risk assessment.

    Science.gov (United States)

    Sutra, Emilie; Spada, Matteo; Burgherr, Peter

    2016-04-01

    While the exploitation of unconventional resources recently shows an extensive development, the stimulation techniques in use in this domain arouse growing public concerns. Often in the shadow of the disputed hydraulic fracturing process, the matrix acidizing is however a complementary or alternative procedure to enhance the reservoir connectivity. Although acidizing processes are widespread within the traditional hydrocarbons sources exploration, the matrix acidizing does not appear to be commonly used in unconventional hydrocarbons formations due to their low permeability. Nonetheless, this process has been recently applied to the Monterey formation, a shale oil play in California. These stimulation fluids are composed by various chemicals, what represents a matter of concern for public as well as for authorities. As a consequence, a risk assessment implying an exposure and toxicity analysis is needed. Focusing on site surface accidents, e.g., leak of a chemical from a storage tank, we develop in this study concentration scenarios for different exposure pathways to estimate the potential environmental risk associated with the use of specific hazardous substances in the matrix acidizing process for unconventional hydrocarbon reservoirs in the USA. Primary, information about the usage of different hazardous substances have been collected in order to extract the most frequently used chemicals. Afterwards, a probabilistic estimation of the environmental risk associated with the use of these chemicals is carried out by comparing the Predicted Environmental Concentrations (PEC) distribution with the Predicted No Effect Concentrations (PNEC) value. The latter is collected from a literature review, whereas the PEC is estimated as probability distribution concentrations in different environmental compartments (e.g., soil) built upon various predefined accident scenarios. By applying a probabilistic methodology for the concentrations, the level at which the used chemicals

  3. Teaching Chemical Equilibrium with the Jigsaw Technique

    Science.gov (United States)

    Doymus, Kemal

    2008-01-01

    This study investigates the effect of cooperative learning (jigsaw) versus individual learning methods on students' understanding of chemical equilibrium in a first-year general chemistry course. This study was carried out in two different classes in the department of primary science education during the 2005-2006 academic year. One of the classes…

  4. Teaching Chemical Equilibrium with the Jigsaw Technique

    Science.gov (United States)

    Doymus, Kemal

    2008-03-01

    This study investigates the effect of cooperative learning (jigsaw) versus individual learning methods on students’ understanding of chemical equilibrium in a first-year general chemistry course. This study was carried out in two different classes in the department of primary science education during the 2005-2006 academic year. One of the classes was randomly assigned as the non-jigsaw group (control) and other as the jigsaw group (cooperative). Students participating in the jigsaw group were divided into four “home groups” since the topic chemical equilibrium is divided into four subtopics (Modules A, B, C and D). Each of these home groups contained four students. The groups were as follows: (1) Home Group A (HGA), representin g the equilibrium state and quantitative aspects of equilibrium (Module A), (2) Home Group B (HGB), representing the equilibrium constant and relationships involving equilibrium constants (Module B), (3) Home Group C (HGC), representing Altering Equilibrium Conditions: Le Chatelier’s principle (Module C), and (4) Home Group D (HGD), representing calculations with equilibrium constants (Module D). The home groups then broke apart, like pieces of a jigsaw puzzle, and the students moved into jigsaw groups consisting of members from the other home groups who were assigned the same portion of the material. The jigsaw groups were then in charge of teaching their specific subtopic to the rest of the students in their learning group. The main data collection tool was a Chemical Equilibrium Achievement Test (CEAT), which was applied to both the jigsaw and non-jigsaw groups The results indicated that the jigsaw group was more successful than the non-jigsaw group (individual learning method).

  5. Evaluation of boiler chemical cleaning techniques

    International Nuclear Information System (INIS)

    1993-04-01

    The EPRI/SGOG process, which has been selected by Ontario Hydro for use at the Bruce A station, is described. This process consists of alternating iron removal and copper removal steps, the two metals which comprise the bulk of the deposit in the Bruce A SGs. The iron removal solvent consists of ethylenediameinetetraacetic acid (EDTA), hydrazine, ammonium hydroxide and a proprietary corrosion inhibitor CCI-801. The copper removal solvent consists of EDTA, ethylene diamine and hydrogen peroxide. Ontario Hydro proposes to clean a bank of four SGs in parallel employing a total of six copper removal steps and four iron removal steps. Cleaning all eight SGs in a single Bruce A unit will generate 2,200 m 3 of liquid waste which will be treated by a wet air oxidation process. The iron and copper sludges will be buried in a landfill site while the liquid waste will be further treated by the Bruce sewage treatment plant. Some ammonia vapour will be generated through the wet air oxidation process and will be vented through a stack on top of the high bay of the spent solvent treatment plant. With the exception of the proprietary corrosion inhibitor, all chemicals that will be employed in the cleaning and waste treatment operations are standard industrial chemicals which are well characterized. No extraordinary hazards are anticipated with their use as long as adequate safety precautions are taken

  6. New analytical techniques for cuticle chemical analysis

    International Nuclear Information System (INIS)

    Schulten, H.R.

    1994-01-01

    1) The analytical methodology of pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and direct pyrolysis-mass spectrometry (Py-MS) using soft ionization techniques by high electric fields (FL) are briefly described. Recent advances of Py-GC/MS and Py-FIMS for the analyses of complex organic matter such as plant materials, humic substances, dissolved organic matter in water (DOM) and soil organic matter (SOM) in agricultural and forest soils are given to illustrate the potential and limitations of the applied methods. 2) Novel applications of Py-GC/MS and Py-MS in combination with conventional analytical data in an integrated, chemometric approach to investigate the dynamics of plant lipids are reported. This includes multivariate statistical investigations on maturation, senescence, humus genesis, and environmental damages in spruce ecosystems. 3) The focal point is the author's integrated investigations on emission-induced changes of selected conifer plant constituents. Pattern recognition of Py-MS data of desiccated spruce needles provides a method for distinguishing needles damaged in different ways and determining the cause. Spruce needles were collected from both controls and trees treated with sulphur dioxide (acid rain), nitrogen dioxide, and ozone under controlled conditions. Py-MS and chemometric data evaluation are employed to characterize and classify leaves and their epicuticular waxes. Preliminary mass spectrometric evaluations of isolated cuticles of different plants such as spruce, ivy, holly, and philodendron, as well as ivy cuticles treated in vivo with air pollutants such as surfactants and pesticides are given. (orig.)

  7. Functionalized polymer nanofibre membranes for protection from chemical warfare stimulants

    International Nuclear Information System (INIS)

    Ramaseshan, Ramakrishnan; Sundarrajan, Subramanian; Liu, Yingjun; Barhate, R S; Lala, Neeta L; Ramakrishna, S

    2006-01-01

    A catalyst for the detoxification of nerve agents is synthesized from β-cyclodextrin (β-CD) and o-iodosobenzoic acid (IBA). Functionalized polymer nanofibre membranes from PVC polymer are fabricated with β-CD, IBA, a blend of β-CD+IBA, and the synthesized catalyst. These functionalized nanofibres are then tested for the decontamination of paraoxon, a nerve agent stimulant, and it is observed that the stimulant gets hydrolysed. The kinetics of hydrolysis is investigated using UV spectroscopy. The rates of hydrolysis for different organophosphate hydrolyzing agents are compared. The reactivity and amount of adsorption of these catalysts are of higher capacity than the conventionally used activated charcoal. A new design for protective wear is proposed based on the functionalized nanofibre membrane

  8. Functionalized polymer nanofibre membranes for protection from chemical warfare stimulants

    Science.gov (United States)

    Ramaseshan, Ramakrishnan; Sundarrajan, Subramanian; Liu, Yingjun; Barhate, R. S.; Lala, Neeta L.; Ramakrishna, S.

    2006-06-01

    A catalyst for the detoxification of nerve agents is synthesized from β-cyclodextrin (β-CD) and o-iodosobenzoic acid (IBA). Functionalized polymer nanofibre membranes from PVC polymer are fabricated with β-CD, IBA, a blend of β-CD+IBA, and the synthesized catalyst. These functionalized nanofibres are then tested for the decontamination of paraoxon, a nerve agent stimulant, and it is observed that the stimulant gets hydrolysed. The kinetics of hydrolysis is investigated using UV spectroscopy. The rates of hydrolysis for different organophosphate hydrolyzing agents are compared. The reactivity and amount of adsorption of these catalysts are of higher capacity than the conventionally used activated charcoal. A new design for protective wear is proposed based on the functionalized nanofibre membrane.

  9. Functionalized polymer nanofibre membranes for protection from chemical warfare stimulants

    Energy Technology Data Exchange (ETDEWEB)

    Ramaseshan, Ramakrishnan [Nanoscience and Nanotechnology Initiative, National University of Singapore, 2 Engineering Drive 3, Singapore 117576, Singapore (Singapore); Sundarrajan, Subramanian [Nanoscience and Nanotechnology Initiative, National University of Singapore, 2 Engineering Drive 3, Singapore 117576, Singapore (Singapore); Liu, Yingjun [Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576, Singapore (Singapore); Barhate, R S [Nanoscience and Nanotechnology Initiative, National University of Singapore, 2 Engineering Drive 3, Singapore 117576, Singapore (Singapore); Lala, Neeta L [Nanoscience and Nanotechnology Initiative, National University of Singapore, 2 Engineering Drive 3, Singapore 117576, Singapore (Singapore); Ramakrishna, S [Nanoscience and Nanotechnology Initiative, National University of Singapore, 2 Engineering Drive 3, Singapore 117576, Singapore (Singapore)

    2006-06-28

    A catalyst for the detoxification of nerve agents is synthesized from {beta}-cyclodextrin ({beta}-CD) and o-iodosobenzoic acid (IBA). Functionalized polymer nanofibre membranes from PVC polymer are fabricated with {beta}-CD, IBA, a blend of {beta}-CD+IBA, and the synthesized catalyst. These functionalized nanofibres are then tested for the decontamination of paraoxon, a nerve agent stimulant, and it is observed that the stimulant gets hydrolysed. The kinetics of hydrolysis is investigated using UV spectroscopy. The rates of hydrolysis for different organophosphate hydrolyzing agents are compared. The reactivity and amount of adsorption of these catalysts are of higher capacity than the conventionally used activated charcoal. A new design for protective wear is proposed based on the functionalized nanofibre membrane.

  10. Chemical vapor deposition: A technique for applying protective coatings

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, T.C. Sr.; Bowman, M.G.

    1979-01-01

    Chemical vapor deposition is discussed as a technique for applying coatings for materials protection in energy systems. The fundamentals of the process are emphasized in order to establish a basis for understanding the relative advantages and limitations of the technique. Several examples of the successful application of CVD coating are described. 31 refs., and 18 figs.

  11. Erythropoiesis stimulating agents and techniques: a challenge for doping analysts.

    Science.gov (United States)

    Jelkmann, W

    2009-01-01

    Recombinant human erythropoietin (rHuEPO) engineered in Chinese hamster ovary (CHO) cell cultures (Epoetin alfa and Epoetin beta) and its hyperglycosylated analogue Darbepoetin alfa are known to be misused by athletes. The drugs can be detected by isoelectric focusing (IEF) and immunoblotting of urine samples, because "EPO" is in reality a mixture of isoforms and the N-glycans of the recombinant products differ from those of the endogenous hormone. However, there is a plethora of novel erythropoiesis stimulating agents (ESAs). Since the originator Epoetins alfa and beta are no longer protected by patent in the European Union, rHuEPO biosimilars have entered the market. In addition, several companies in Asia, Africa and Latin America produce copied rHuEPOs for clinical purposes. While the amino acid sequence of all Epoetins is identical, the structure of their glycans differs depending on the mode of production. Some products contain more acidic and others more basic EPO isoforms. Epoetin delta is special, as it was engineered by homologous recombination in human fibrosarcoma cells (HT-1080), thus lacking N-glycolylneuraminic acid like native human EPO. ESAs under development include EPO fusion proteins, synthetic erythropoiesis stimulating protein (SEP) and peptidic (Hematide(), CNTO 528) as well as non-peptidic EPO mimetics. Furthermore, preclinical respectively clinical trials have been performed with small orally active drugs that stimulate endogenous EPO production by activating the EPO promoter ("GATA-inhibitors": diazepane derivatives) or enhancer ("HIF-stabilizers": 2-oxoglutarate analogues). The prohibited direct EPO gene transfer may become a problem in sports only in the future.

  12. An advanced technique of the search for the stimulated gamma-ray emission

    International Nuclear Information System (INIS)

    Strilchuk, N.V.; Kirischuk, V.I.

    1999-01-01

    An experiment which is not based on the assumption that the stimulating and stimulated photons are time-coincident, is proposed. The idea is to compare, for the source in the form of a long filament, the number of simple pulses, corresponding to the isomeric transition energy, counted in the axial direction with the number seen off-axis by the same detector. It is interesting that if the stimulating and stimulated photons are time-coincident, such techniques has essential advantages as well. (authors)

  13. Development of techniques for tagging precursor and essential chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Swansiger, W.A.; Shepodd, T.J. [Sandia National Labs., Livermore, CA (United States); Phillips, M.L.F. [Sandia National Labs., Albuquerque, NM (United States)

    1994-01-01

    The ability to identify the manufacturers and distributors of chemicals seized in raids of illicit drug labs would be of great value in controlling the diversion of these chemicals. We developed a tagging scheme based on the addition of sub-ppM concentrations of various combinations of rare-earth elements to the target chemicals and evaluated a number of techniques for detecting the tags. We developed soluble tags for tagging liquids and selected Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) as the preferred detection technique. We developed insoluble tags for tagging solids and developed methods to analyze them and mix them into solid precursors. We have successfully demonstrated the tagging of several solvents and two of the precursor chemicals used in one of the most popular clandestine methamphetamine syntheses (ephedrine reacting with hydriodic acid/red phosphorus). The tagging scheme is capable of yielding tens of thousands of signatures (using holmium as an internal standard and up to 9 rare-earths at up to 3 concentrations yields 3{sup 9} {minus} 1 = 19,682 signatures) and is applicable to most of the chemicals on the precursor and essential chemicals list. In the concentrations employed, the tags are safe enough to be added to pharmaceuticals and cheap enough to tag tanker loads of chemicals.

  14. Characteristics of nanosized zirconia prepared by plasma and chemical technique

    International Nuclear Information System (INIS)

    Kuznetsova, L.; Grabis, J.; Heidemane, G.

    2003-01-01

    The studied preparation method of zirconia using the plasma technique, azeotropic distillation and glycine routes ensure obtaining of nano sized powders with close average particle size but different crystallite size and phase composition. The sinterability of nano sized zirconia particles prepared by plasma technique or wet-chemical methods is similar and depends on the green density of pressed powders, improvement of with can be achieved by using of granulated precursors. (authors)

  15. Fiber break location technique utilizing stimulated Brillouin scattering effects in optical fiber

    International Nuclear Information System (INIS)

    Bakar, A A A; Al-Mansoori, M H; Mahdi, M A; Mohd Azau, M A; Zainal Abidin, M S

    2009-01-01

    A new technique of fiber break detection system in optical communication networks is proposed and experimentally demonstrated in this paper. This technique is based-on continuous wave light source rather than pulsed source that is commonly deployed in existing techniques. The nonlinear effect of stimulated Brillouin scattering is manipulated to locate the fiber-break position in optical communication networks. This technique enables the utilization of a less-sensitive photodetector to detect the Brillouin Stokes line since its intensity increases with the fiber length in the detectable region. The fiber break location can be determined with accuracy of more than 98% for fiber length less than 50 km using this technique

  16. In vivo chemical and structural analysis of plant cuticular waxes using stimulated Raman scattering microscopy.

    Science.gov (United States)

    Littlejohn, George R; Mansfield, Jessica C; Parker, David; Lind, Rob; Perfect, Sarah; Seymour, Mark; Smirnoff, Nicholas; Love, John; Moger, Julian

    2015-05-01

    The cuticle is a ubiquitous, predominantly waxy layer on the aerial parts of higher plants that fulfils a number of essential physiological roles, including regulating evapotranspiration, light reflection, and heat tolerance, control of development, and providing an essential barrier between the organism and environmental agents such as chemicals or some pathogens. The structure and composition of the cuticle are closely associated but are typically investigated separately using a combination of structural imaging and biochemical analysis of extracted waxes. Recently, techniques that combine stain-free imaging and biochemical analysis, including Fourier transform infrared spectroscopy microscopy and coherent anti-Stokes Raman spectroscopy microscopy, have been used to investigate the cuticle, but the detection sensitivity is severely limited by the background signals from plant pigments. We present a new method for label-free, in vivo structural and biochemical analysis of plant cuticles based on stimulated Raman scattering (SRS) microscopy. As a proof of principle, we used SRS microscopy to analyze the cuticles from a variety of plants at different times in development. We demonstrate that the SRS virtually eliminates the background interference compared with coherent anti-Stokes Raman spectroscopy imaging and results in label-free, chemically specific confocal images of cuticle architecture with simultaneous characterization of cuticle composition. This innovative use of the SRS spectroscopy may find applications in agrochemical research and development or in studies of wax deposition during leaf development and, as such, represents an important step in the study of higher plant cuticles. © 2015 American Society of Plant Biologists. All Rights Reserved.

  17. Temperature lowering in cryogenic chemical-synthesis techniques and system

    International Nuclear Information System (INIS)

    Martinez, H.E.; Nelson, T.O.; Vikdal, L.N.

    1993-01-01

    When evaluating a chemical synthesis process for a reaction that occurs on the cryogenically cooled walls, it is sometimes necessary to reduce the wall temperatures to enhance the chemical process. To evaluate the chemical process at lower than atmospheric boiling of liquid nitrogen, we built a system and used it to reduce the temperature of the liquid nitrogen. The technique of lowering the liquid nitrogen temperature by reducing the pressure of the boil-off is established knowledge. This paper presents the engineering aspects of the system, design features, equipment requirements, methods of control, and results of the chemical synthesis. The heat input to the system was ∼400 watts, placing a relatively large demand on the pumping system. Our system is a scale-up of the small laboratory experiment, and it provides the information needed to design an effective system. The major problem encountered was the large quantity of liquid escaping the system during the processing, placing a large gas load on the vacuum system

  18. Optically stimulated luminescence from quartz measured using the linear modulation technique

    International Nuclear Information System (INIS)

    Bulur, E.; Boetter-Jensen, L.; Murray, A.S.

    2000-01-01

    The optically stimulated luminescence (OSL) from heated natural quartz has been investigated using the linear modulation technique (LMT), in which the excitation light intensity is increased linearly during stimulation. In contrast to conventional stimulation, which usually produces a monotonically decreasing signal, linearly increasing the stimulation power gives peaks in the signal as a function of time. In cases where the OSL signal contains more than one component, the linear increase in power of the stimulation light may result in a curve containing overlapping peaks, where the most easily stimulated component occurs at a shorter time. This allows the separation of the overlapping OSL components, which are assumed to originate from different traps. The LM-OSL curve from quartz shows an initial peak followed by a broad one. Deconvolution using curve fitting has shown that the composite OSL curve from quartz can be approximated well by using a linear combination of first-order peaks. In addition to the three known components, i.e. fast, medium and slow components from continuous-wave-OSL studies, an additional slow component is also identified for the first time. The dose responses and thermal stabilities of the various components are also studied

  19. Electrochemical and Chemical Complications Resulting from Yeast Extract Addition to Stimulate Microbial Growth

    Science.gov (United States)

    2016-09-22

    including strains of Saccharomyces cerevisiae grown on molasses-based media, debittered brewers yeasts (strains of Saccharo- myces cerevisiae or...RESPONSIBLE PERSON 19b. TELEPHONE NUMBER (Include area code) Technical Note: Electrochemical and Chemical Complications Resulting from Yeast Extract...Addition to Stimulate Microbial Growth Jason S. Lee‡,* and Brenda J. Little* ABSTRACT Addition of 1 g/L yeast extract (YE) to sterile, aerobic

  20. Thermoluminescence as a complementary technique for the toxicological evaluation of chemicals in photosynthetic organisms

    Energy Technology Data Exchange (ETDEWEB)

    Repetto, Guillermo, E-mail: grepkuh@upo.es [Departamento de Biología Molecular e Ingeniería Bioquímica, Área de Toxicología, Universidad Pablo de Olavide, Carretera de Utrera km. 1, 41013 Seville (Spain); Zurita, Jorge L. [Departamento de Biología Molecular e Ingeniería Bioquímica, Área de Toxicología, Universidad Pablo de Olavide, Carretera de Utrera km. 1, 41013 Seville (Spain); Roncel, Mercedes; Ortega, José M. [Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla-CSIC, Américo Vespucio 49, 41092 Seville (Spain)

    2015-01-15

    Highlights: • There are very few toxicological applications of thermoluminescence. • It is a luminescence emission induced by heating the sample in the dark. • It is useful for study the photosystem II function and the level of lipid peroxidation. - Abstract: Thermoluminescence is a simple technique very useful for studying electron transfer reactions on photosystem II (standard thermoluminescence) or the level of lipid peroxidation in membranes (high temperature thermoluminescence) in photosynthetic organisms. Both techniques were used to investigate the effects produced on Chlorella vulgaris cells by six compounds: the chemical intermediates bromobenzene and diethanolamine, the antioxidant propyl gallate, the semiconductor indium nitrate, the pesticide sodium monofluoroacetate and the antimalarial drug chloroquine. Electron transfer activity of the photosystem II significantly decreased after the exposure of Chlorella cells to all the six chemicals used. Lipid peroxidation was slightly decreased by the antioxidant propyl gallate, not changed by indium nitrate and very potently stimulated by diethanolamine, chloroquine, sodium monofluoroacetate and bromobenzene. For five of the chemicals studied (not bromobenzene) there is a very good correlation between the cytotoxic effects in Chlorella cells measured by the algal growth inhibition test, and the inhibition of photosystem II activity. The results suggest that one very important effect of these chemicals in Chlorella cells is the inhibition of photosynthetic metabolism by the blocking of photosystem II functionality. In the case of sodium monofluoroacetate, diethanolamine and chloroquine this inhibition seems to be related with the induction of high level of lipid peroxidation in cells that may alter the stability of photosystem II. The results obtained by both techniques supply information that can be used as a supplement to the growth inhibition test and allows a more complete assessment of the effects of

  1. Thermoluminescence as a complementary technique for the toxicological evaluation of chemicals in photosynthetic organisms

    International Nuclear Information System (INIS)

    Repetto, Guillermo; Zurita, Jorge L.; Roncel, Mercedes; Ortega, José M.

    2015-01-01

    Highlights: • There are very few toxicological applications of thermoluminescence. • It is a luminescence emission induced by heating the sample in the dark. • It is useful for study the photosystem II function and the level of lipid peroxidation. - Abstract: Thermoluminescence is a simple technique very useful for studying electron transfer reactions on photosystem II (standard thermoluminescence) or the level of lipid peroxidation in membranes (high temperature thermoluminescence) in photosynthetic organisms. Both techniques were used to investigate the effects produced on Chlorella vulgaris cells by six compounds: the chemical intermediates bromobenzene and diethanolamine, the antioxidant propyl gallate, the semiconductor indium nitrate, the pesticide sodium monofluoroacetate and the antimalarial drug chloroquine. Electron transfer activity of the photosystem II significantly decreased after the exposure of Chlorella cells to all the six chemicals used. Lipid peroxidation was slightly decreased by the antioxidant propyl gallate, not changed by indium nitrate and very potently stimulated by diethanolamine, chloroquine, sodium monofluoroacetate and bromobenzene. For five of the chemicals studied (not bromobenzene) there is a very good correlation between the cytotoxic effects in Chlorella cells measured by the algal growth inhibition test, and the inhibition of photosystem II activity. The results suggest that one very important effect of these chemicals in Chlorella cells is the inhibition of photosynthetic metabolism by the blocking of photosystem II functionality. In the case of sodium monofluoroacetate, diethanolamine and chloroquine this inhibition seems to be related with the induction of high level of lipid peroxidation in cells that may alter the stability of photosystem II. The results obtained by both techniques supply information that can be used as a supplement to the growth inhibition test and allows a more complete assessment of the effects of

  2. THE GAME TECHNIQUE NTCHNIQUE STIMULATING LEARNING ACTIVITY OF JUNIOR STUDENTS SPECIALIZING IN ECONOMICS

    Directory of Open Access Journals (Sweden)

    Juri. S. Ezrokh

    2014-01-01

    Full Text Available The research is aimed at specifying and developing the modern control system of current academic achievements of junior university students; and the main task is to find the adequate ways for stimulating the junior students’ learning activities, and estimating their individual achievements.Methods: The author applies his own assessment method for estimating and stimulating students’ learning outcomes, based on the rating-point system of gradually obtained points building up a student’s integrated learning outcomes.Results: The research findings prove that implementation of the given method can increase the motivational, multiplicative and controlling components of the learning process.Scientific novelty: The method in question is based on the new original game approach to controlling procedures and stimulation of learning motivation of the economic profile students.Practical significance: The recommended technique can intensify the incentivebased training activities both in and outside a classroom, developing thereby students’ professional and personal qualities.

  3. MAGNETIC VERSUS ELECTRICAL STIMULATION IN THE INTERPOLATION TWITCH TECHNIQUE OF ELBOW FLEXORS

    Directory of Open Access Journals (Sweden)

    Sofia I. Lampropoulou

    2012-12-01

    Full Text Available The study compared peripheral magnetic with electrical stimulation of the biceps brachii m. (BB in the single pulse Interpolation Twitch Technique (ITT. 14 healthy participants (31±7 years participated in a within-subjects repeated-measures design study. Single, constant-current electrical and magnetic stimuli were delivered over the motor point of BB with supramaximal intensity (20% above maximum at rest and at various levels of voluntary contraction. Force measurements from right elbow isometric flexion and muscle electromyograms (EMG from the BB, the triceps brachii m. (TB and the abductor pollicis brevis m. (APB were obtained. The twitch forces at rest and maximal contractions, the twitch force-voluntary force relationship, the M-waves and the voluntary activation (VA of BB between magnetic and electrical stimulation were compared. The mean amplitude of the twitches evoked at MVC was not significantly different between electrical (0.62 ± 0.49 N and magnetic (0.81 ± 0.49 N stimulation (p > 0.05, and the maximum VA of BB was comparable between electrical (95% and magnetic (93% stimulation (p > 0. 05. No differences (p >0.05 were revealed in the BB M-waves between electrical (13.47 ± 0.49 mV.ms and magnetic (12.61 ± 0.58 mV.ms stimulation. The TB M-waves were also similar (p > 0.05 but electrically evoked APB M-waves were significantly larger than those evoked by magnetic stimulation (p < 0.05. The twitch-voluntary force relationship over the range of MVCs was best described by non-linear functions for both electrical and magnetic stimulation. The electrically evoked resting twitches were consistently larger in amplitude than the magnetically evoked ones (mean difference 3.1 ± 3.34 N, p < 0.05. Reduction of the inter-electrodes distance reduced the twitch amplitude by 6.5 ± 6.2 N (p < 0.05. The fundamental similarities in voluntary activation assessment of BB with peripheral electrical and magnetic stimulation point towards a promising

  4. Two-step tunneling technique of deep brain stimulation extension wires-a description.

    Science.gov (United States)

    Fontaine, Denys; Vandersteen, Clair; Saleh, Christian; von Langsdorff, Daniel; Poissonnet, Gilles

    2013-12-01

    While a significant body of literature exists on the intracranial part of deep brain stimulation surgery, the equally important second part of the intervention related to the subcutaneous tunneling of deep brain stimulation extension wires is rarely described. The tunneling strategy can consist of a single passage of the extension wires from the frontal incision site to the subclavicular area, or of a two-step approach that adds a retro-auricular counter-incision. Each technique harbors the risk of intraoperative and postoperative complications. At our center, we perform a two-step tunneling procedure that we developed based on a cadaveric study. In 125 consecutive patients operated since 2002, we did not encounter any complication related to our tunneling method. Insufficient data exist to fully evaluate the advantages and disadvantages of each tunneling technique. It is of critical importance that authors detail their tunneling modus operandi and report the presence or absence of complications. This gathered data pool may help to formulate a definitive conclusions on the safest method for subcutaneous tunneling of extension wires in deep brain stimulation.

  5. Calculational techniques for estimating population doses from radioactivity in natural gas from nuclearly stimulated wells

    International Nuclear Information System (INIS)

    Barton, C.J.; Moore, R.E.; Rohwer, P.S.; Kaye, S.V.

    1975-01-01

    Techniques for estimating radiation doses from exposure to combustion products of natural gas obtained from wells created by use of nuclear explosives were first developed in the Gasbuggy Project. These techniques were refined and extended by development of a number of computer codes in studies related to the Rulison Project, the second in the series of joint government-industry efforts to demonstrate the feasibility of increasing natural gas production from low-permeability rock formations by use of nuclear explosives. These techniques are described and dose estimates that illustrate their use are given. These dose estimation studies have been primarily theoretical, but we have tried to make our hypothetical exposure conditions correspond as closely as possible with conditions that could exist if nuclearly stimulated natural gas is used commercially. (author)

  6. Active sampling technique to enhance chemical signature of buried explosives

    Science.gov (United States)

    Lovell, John S.; French, Patrick D.

    2004-09-01

    Deminers and dismounted countermine engineers commonly use metal detectors, ground penetrating radar and probes to locate mines. Many modern landmines have a very low metal content, which severely limits the effectiveness of metal detectors. Canines have also been used for landmine detection for decades. Experiments have shown that canines smell the explosives which are known to leak from most types of landmines. The fact that dogs can detect landmines indicates that vapor sensing is a viable approach to landmine detection. Several groups are currently developing systems to detect landmines by "sniffing" for the ultra-trace explosive vapors above the soil. The amount of material that is available to passive vapor sensing systems is limited to no more than the vapor in equilibrium with the explosive related chemicals (ERCs) distributed in the surface soils over and near the landmine. The low equilibrium vapor pressure of TNT in the soil/atmosphere boundary layer and the limited volume of the boundary layer air imply that passive chemical vapor sensing systems require sensitivities in the picogram range, or lower. ADA is working to overcome many of the limitations of passive sampling methods, by the use of an active sampling method that employs a high-powered (1,200+ joules) strobe lamp to create a highly amplified plume of vapor and/or ERC-bearing fine particulates. Initial investigations have demonstrated that this approach can amplify the detectability of TNT by two or three orders of magnitude. This new active sampling technique could be used with any suitable explosive sensor.

  7. New decontamination techniques: chemical gels, electropolishing and abrasives

    International Nuclear Information System (INIS)

    Brunel, G.; Gauchon, J.P.; Kervegant, Y.; Josso, F.

    1991-01-01

    The decommissioning of nuclear installations requires decontamination techniques that are efficient, simple to apply and producing a small amount of wastes, which are easy to process. With a view to this, three decontamination methods, which appear to be particularly suited to decommissioning, have been studied. These three methods are: - spraying of gels carrying chemical decontaminating agents, - electropolishing with a swab device, - abrasives blasting. After parametric tests on non-radioactive and active samples, the industrial application of these methods in the dismantling of installations was studied. These industrial applications concern: - decontamination of pieces coming from the German BWR ISAR by immersion and gel spraying, - decontamination, mainly by gel spraying, and dismantling of the BRENNILIS bituminisation plant, - decontamination of part of the cooling circuit of the graphite gas reactor G2 by gel spraying, - decontamination of a component of the FBR SuperPhenix, using dry abrasives blasting. During the first three applications, generated secondary wastes volume and form were determined. 33 tabs., 16 figs., 12 refs

  8. Detection of irradiated spices using photo-stimulated luminescence technique (PSL)

    Energy Technology Data Exchange (ETDEWEB)

    Ramli, Ros Anita Ahmad; Yasir, Muhamad Samudi [Faculty of Science and Technology, National University of Malaysia, Bangi, 43000 Kajang, Selangor (Malaysia); Othman, Zainon; Abdullah, Wan Saffiey Wan [Malaysian Nuclear Agency, Bangi 43000 Kajang, Selangor (Malaysia)

    2014-09-03

    Photo-stimulated luminescence (PSL) technique was applied to detect irradiated black pepper (Piper nigrum), cinnamon (Cinnamomum verum) and turmeric (Curcuma longa) after dark storage for 1 day, 3 and 6 months. Using screening and calibrated PSL, all samples were correctly discriminated between non-irradiated and spices irradiated with doses 1, 5 and 10 kGy. The PSL photon counts (PCs) of irradiated spices increased with increasing dose, with turmeric showing highest sensitivity index to irradiation compared to black pepper and cinnamon. The differences in response are possibly attributed to the varying quantity and quality of silicate minerals present in each spice sample. PSL signals of all irradiated samples reduced after 3 and 6 months storage. The results of this study provide a useful database on the applicability of PSL technique for the detection of Malaysian irradiated spices.

  9. Effects of pump recycling technique on stimulated Brillouin scattering threshold: a theoretical model.

    Science.gov (United States)

    Al-Asadi, H A; Al-Mansoori, M H; Ajiya, M; Hitam, S; Saripan, M I; Mahdi, M A

    2010-10-11

    We develop a theoretical model that can be used to predict stimulated Brillouin scattering (SBS) threshold in optical fibers that arises through the effect of Brillouin pump recycling technique. Obtained simulation results from our model are in close agreement with our experimental results. The developed model utilizes single mode optical fiber of different lengths as the Brillouin gain media. For 5-km long single mode fiber, the calculated threshold power for SBS is about 16 mW for conventional technique. This value is reduced to about 8 mW when the residual Brillouin pump is recycled at the end of the fiber. The decrement of SBS threshold is due to longer interaction lengths between Brillouin pump and Stokes wave.

  10. Detection of irradiated spices using photo-stimulated luminescence technique (PSL)

    Science.gov (United States)

    Ramli, Ros Anita Ahmad; Yasir, Muhamad Samudi; Othman, Zainon; Abdullah, Wan Saffiey Wan

    2014-09-01

    Photo-stimulated luminescence (PSL) technique was applied to detect irradiated black pepper (Piper nigrum), cinnamon (Cinnamomum verum) and turmeric (Curcuma longa) after dark storage for 1 day, 3 and 6 months. Using screening and calibrated PSL, all samples were correctly discriminated between non-irradiated and spices irradiated with doses 1, 5 and 10 kGy. The PSL photon counts (PCs) of irradiated spices increased with increasing dose, with turmeric showing highest sensitivity index to irradiation compared to black pepper and cinnamon. The differences in response are possibly attributed to the varying quantity and quality of silicate minerals present in each spice sample. PSL signals of all irradiated samples reduced after 3 and 6 months storage. The results of this study provide a useful database on the applicability of PSL technique for the detection of Malaysian irradiated spices.

  11. Detection of irradiated spices using photo-stimulated luminescence technique (PSL)

    International Nuclear Information System (INIS)

    Ramli, Ros Anita Ahmad; Yasir, Muhamad Samudi; Othman, Zainon; Abdullah, Wan Saffiey Wan

    2014-01-01

    Photo-stimulated luminescence (PSL) technique was applied to detect irradiated black pepper (Piper nigrum), cinnamon (Cinnamomum verum) and turmeric (Curcuma longa) after dark storage for 1 day, 3 and 6 months. Using screening and calibrated PSL, all samples were correctly discriminated between non-irradiated and spices irradiated with doses 1, 5 and 10 kGy. The PSL photon counts (PCs) of irradiated spices increased with increasing dose, with turmeric showing highest sensitivity index to irradiation compared to black pepper and cinnamon. The differences in response are possibly attributed to the varying quantity and quality of silicate minerals present in each spice sample. PSL signals of all irradiated samples reduced after 3 and 6 months storage. The results of this study provide a useful database on the applicability of PSL technique for the detection of Malaysian irradiated spices

  12. A new technique of "midline anchoring" in spinal cord stimulation dramatically reduces lead migration.

    Science.gov (United States)

    Mironer, Y Eugene; Brown, Christopher; Satterthwaite, John R; Cohen, Mary; Tonder, Lisa M; Grumman, Steve

    2004-01-01

    Spinal cord stimulation (SCS) is a popular method of treatment of chronic pain. Unfortunately, migration of the lead continues to be a serious complication of this therapy. In an attempt to reduce lateral migration of the SCS lead, we performed a retrospective assessment of a new technique of percutaneous lead placement. This new method of "midline anchoring" of the lead using the plica mediana dorsalis was tested against conventional technique in a retrospective study involving 122 trials and 91 implants of SCS over a period of five years. The use of "midline anchoring" resulted in a decrease in lead migration from 23% to 6% after trial insertion and from 24% to 7% after implantation. We conclude that "midline anchoring" of the SCS lead is an effective method of preventing lead migration.

  13. New Technique for Speciation of Uranium in Sediments Following Acetate-Stimulated Bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    2011-06-22

    Acetate-stimulated bioremediation is a promising new technique for sequestering toxic uranium contamination from groundwater. The speciation of uranium in sediments after such bioremediation attempts remains unknown as a result of low uranium concentration, and is important to analyzing the stability of sequestered uranium. A new technique was developed for investigating the oxidation state and local molecular structure of uranium from field site sediments using X-Ray Absorption Spectroscopy (XAS), and was implemented at the site of a former uranium mill in Rifle, CO. Glass columns filled with bioactive Rifle sediments were deployed in wells in the contaminated Rifle aquifer and amended with a hexavalent uranium (U(VI)) stock solution to increase uranium concentration while maintaining field conditions. This sediment was harvested and XAS was utilized to analyze the oxidation state and local molecular structure of the uranium in sediment samples. Extended X-Ray Absorption Fine Structure (EXAFS) data was collected and compared to known uranium spectra to determine the local molecular structure of the uranium in the sediment. Fitting was used to determine that the field site sediments did not contain uraninite (UO{sub 2}), indicating that models based on bioreduction using pure bacterial cultures are not accurate for bioremediation in the field. Stability tests on the monomeric tetravalent uranium (U(IV)) produced by bioremediation are needed in order to assess the efficacy of acetate-stimulation bioremediation.

  14. Postvagotomy acid secretion and mucosal blood flow during beta-adrenoceptor stimulation and universal chemical sympathectomy in dogs

    DEFF Research Database (Denmark)

    Hovendal, C P

    1983-01-01

    The aim of the present study was to examine the effect of beta-adrenoceptor stimulation, alpha blockade, and elimination of the adrenergic nerve function on mucosal blood flow and acid secretion in parietal-cell-vagotomized (PCV) gastric fistula dogs. Isoprenaline inhibited pentagastrin-stimulate......The aim of the present study was to examine the effect of beta-adrenoceptor stimulation, alpha blockade, and elimination of the adrenergic nerve function on mucosal blood flow and acid secretion in parietal-cell-vagotomized (PCV) gastric fistula dogs. Isoprenaline inhibited pentagastrin...... to chemical sympathectomy with 6-hydroxy-dopamine, a false neurotransmitter that selectively destroys the adrenergic nerve terminals. Chemical sympathectomy increased the pentagastrin-stimulated gastric acid secretion and stabilized the mucosal blood flow at the level before vagotomy, but with an increased...... ratio between blood flow and acid secretion. One may conclude that the sympathetic nerve system influences gastric function after vagotomy....

  15. Chemical solution deposition techniques for epitaxial growth of complex oxides

    NARCIS (Netherlands)

    ten Elshof, Johan E.; Koster, G.; Huijben, Mark; Rijnders, G.

    2015-01-01

    The chemical solution deposition (CSD) process is a wet-chemical process that is employed to fabricate a wide variety of amorphous and crystalline oxide thin films. This chapter describes the typical steps in a CSD process and their influence on the final microstructure and properties of films, and

  16. Multitracer techniques: applications in chemical and life sciences

    International Nuclear Information System (INIS)

    Nayak, Dalia

    2001-01-01

    The scope and approaches of the 'multitracer technique' have briefly been reviewed. The various aspects of the 'multitracer technique' include, the methods of accelerator production of 'multitracers' and their separation, the application of this technique in the study of adsorption of metal ions on solid surfaces and in the study of distribution of trace elements in plants and animals

  17. Comparison of Three Sample Preparation Methods for Analysis of Chemical Warfare Agent Stimulants in Water

    International Nuclear Information System (INIS)

    Alessandro Sassolini

    2015-01-01

    Analytical chemistry in CBRNe (Chemical Biological Radiological Nuclear explosive) context requires not only high quality data; quickness, ruggedness and robustness are also mandatory. In this work, three samples preparation methods were compared using several organophosphorus pesticides as test compounds, used as stimulants of nerve CWA (Chemical Warfare Agents) to choose the one with best characteristics. Result was obtained better with the Dispersive Liquid-Liquid Micro Extraction (DLLME), relatively new in CBRNe field, obtaining uncertainty for different simulants between 8 and 15 % while a quantification limit between 0.01 and 0.08 μg/ l. To optimize this extraction method, different organo chlorinated solvents also tested but not relevant difference in these tests was obtained. In this work, all samples were analyzed by using a gas chromatography coupled with mass spectrometer (GC-MS) and also with Gas Chromatograph coupled with Nitrogen Phosphorous Detector (NPD) for DLLME samples to evaluate a low cost and rugged instrument adapt to field analytical methods with good performance in terms of uncertainty and sensibility even if poorer respect to the mass spectrometry. (author)

  18. Dorsolateral prefrontal cortex, working memory and episodic memory processes: insight through transcranial magnetic stimulation techniques

    Institute of Scientific and Technical Information of China (English)

    Michela Balconi

    2013-01-01

    The ability to recall and recognize facts we experienced in the past is based on a complex mechanism in which several cerebral regions are implicated.Neuroimaging and lesion studies agree in identifying the frontal lobe as a crucial structure for memory processes,and in particular for working memory and episodic memory and their relationships.Furthermore,with the introduction of transcranial magnetic stimulation (TMS) a new way was proposed to investigate the relationships between brain correlates,memory functions and behavior.The aim of this review is to present the main findings that have emerged from experiments which used the TMS technique for memory analysis.They mainly focused on the role of the dorsolateral prefrontal cortex in memory process.Furthermore,we present state-of-the-art evidence supporting a possible use of TMS in the clinic.Specifically we focus on the treatment of memory deficits in depression and anxiety disorders.

  19. Comparison of the shock artifacts induced by tripolar and bipolar electrical stimulation techniques.

    Science.gov (United States)

    Wee, A S; Jiles, K; Brennan, R

    2001-01-01

    Tripolar and bipolar electrical stimulation procedures were performed on the upper limbs of eight subjects. The mid-forearm was stimulated electrically (tripolar or bipolar) by surface electrodes, and the induced stimulus shock artifacts were recorded simultaneously from the wrist and elbow. During tripolar stimulation, two types of stimulating configurations were utilized: with the center electrode designated as the cathode and the two outermost electrodes connected to a common anode, and vice versa. During bipolar stimulation, the center electrode served as one pole of the stimulator, and one of the two outermost electrodes of the tripolar stimulator was disconnected. The stimulus intensity was kept constant in all stimulating procedures. Artifacts were reduced significantly during tripolar compared to bipolar stimulation, if the outermost electrodes of the tripolar stimulator (which were facing the recording electrodes) were also oriented toward the recording sites during bipolar stimulation and had the same stimulus polarity. Artifacts were slightly reduced in amplitude from tripolar stimulation, if the center electrode were oriented toward the recording sites during bipolar stimulation and had the same stimulus polarity as previously used during tripolar stimulation.

  20. Transcranial magnetic stimulation research on reading and dyslexia: a new clinical intervention technique for treating dyslexia?

    Directory of Open Access Journals (Sweden)

    Maurits van den Noort

    2015-01-01

    Full Text Available Nowadays, several noninvasive neuroimaging techniques, including transcranial magnetic stimulation (TMS, exist. The working mechanism behind TMS is a rapidly changing magnetic field that generates an electric current via electromagnetic induction. When the coil is placed on the scalp, the magnetic field generates a physiological reaction in the underlying neural tissue. The TMS-induced change in the participant′s behavior is used by researchers to investigate the causal relations between specific brain areas and cognitive functions such as language. A variant of TMS has been developed, which is called rapid-rate TMS (rTMS. In this review, three databases (Medline, Educational Resources Information Center, and Scopus were searched for rTMS studies on normal reading and dyslexia with a cut-off date of October 31, 2014. rTMS was found to be a valuable tool for investigating questions related to reading research, both on the word and the sentence level. Moreover, it can be successfully used in research on dyslexia. Recently, (high-frequency rTMS has been used as a "clinical" intervention technique for treating dyslexia and for improving reading performance by exciting underactive reading pathways in the brain. Finally, we end the paper with a discussion of future directions in the field of rTMS research and dyslexia, for instance, the promising prospect of combining TMS with simultaneous electroencephalographic imaging.

  1. Comparison of peripheral nerve stimulator versus ultrasonography guided axillary block using multiple injection technique.

    Science.gov (United States)

    Kumar, Alok; Sharma, Dk; Sibi, Maj E; Datta, Barun; Gogoi, Biraj

    2014-01-01

    The established methods of nerve location were based on either proper motor response on nerve stimulation (NS) or ultrasound guidance. In this prospective, randomised, observer-blinded study, we compared ultrasound guidance with NS for axillary brachial plexus block using 0.5% bupivacaine with the multiple injection techniques. A total of 120 patients receiving axillary brachial plexus block with 0.5% bupivacaine, using a multiple injection technique, were randomly allocated to receive either NS (group NS, n = 60), or ultrasound guidance (group US, n = 60) for nerve location. A blinded observer recorded the onset of sensory and motor blocks, skin punctures, needle redirections, procedure-related pain and patient satisfaction. The median (range) number of skin punctures were 2 (2-4) in group US and 3 (2-5) in group NS (P =0.27). Insufficient block was observed in three patient (5%) of group US and four patients (6.67%) of group NS (P > =0.35). Patient acceptance was similarly good in the two groups. Multiple injection axillary blocks with ultrasound guidance provided similar success rates and comparable incidence of complications as compared with NS guidance with 20 ml 0.5% bupivacaine.

  2. Comparison of peripheral nerve stimulator versus ultrasonography guided axillary block using multiple injection technique

    Directory of Open Access Journals (Sweden)

    Alok Kumar

    2014-01-01

    Full Text Available Background: The established methods of nerve location were based on either proper motor response on nerve stimulation (NS or ultrasound guidance. In this prospective, randomised, observer-blinded study, we compared ultrasound guidance with NS for axillary brachial plexus block using 0.5% bupivacaine with the multiple injection techniques. Methods : A total of 120 patients receiving axillary brachial plexus block with 0.5% bupivacaine, using a multiple injection technique, were randomly allocated to receive either NS (group NS, n = 60, or ultrasound guidance (group US, n = 60 for nerve location. A blinded observer recorded the onset of sensory and motor blocks, skin punctures, needle redirections, procedure-related pain and patient satisfaction. Results: The median (range number of skin punctures were 2 (2-4 in group US and 3 (2-5 in group NS (P =0.27. Insufficient block was observed in three patient (5% of group US and four patients (6.67% of group NS (P > =0.35. Patient acceptance was similarly good in the two groups. Conclusion: Multiple injection axillary blocks with ultrasound guidance provided similar success rates and comparable incidence of complications as compared with NS guidance with 20 ml 0.5% bupivacaine.

  3. Current trends in pedicle screw stimulation techniques: lumbosacral, thoracic, and cervical levels.

    Science.gov (United States)

    Isley, Michael R; Zhang, Xiao-Feng; Balzer, Jeffrey R; Leppanen, Ronald E

    2012-06-01

    Unequivocally, pedicle screw instrumentation has evolved as a primary construct for the treatment of both common and complex spinal disorders. However an inevitable and potentially major complication associated with this type of surgery is misplacement of a pedicle screw(s) which may result in neural and vascular complications, as well as impair the biomechanical stability of the spinal instrumentation resulting in loss of fixation. In light of these potential surgical complications, critical reviews of outcome data for treatment of chronic, low-back pain using pedicle screw instrumentation concluded that "pedicle screw fixation improves radiographically demonstrated fusion rates;" however the expense and complication rates for such constructs are considerable in light of the clinical benefit (Resnick et al. 2005a). Currently, neuromonitoring using free-run and evoked (triggered) electromyography (EMG) is widely used and advocated for safer and more accurate placement of pedicle screws during open instrumentation procedures, and more recently, guiding percutaneous placement (minimally invasive) where the pedicle cannot be easily inspected visually. The latter technique, evoked or triggered EMG when applied to pedicle screw instrumentation surgeries, has been referred to as the pedicle screw stimulation technique. As concluded in the Position Statement by the American Society of Neurophysiological Monitoring (ASNM), multimodality neuromonitoring using free-run EMG and the pedicle screw stimulation technique was considered a practice option and not yet a standard of care (Leppanen 2005). Subsequently, the American Association of Neurological Surgeons/Congress of Neurological Surgeons (AANS/CNS) Joint Section on Disorders of the Spine and Peripheral Nerves published their "Guidelines for the Performance of Fusion Procedures for Degenerative Disease of the Lumbar Spine" (Heary 2005, Resnick et al. 2005a, Resnick et al. 2005b). It was concluded that the "primary

  4. Chemical allergens stimulate human epidermal keratinocytes to produce lymphangiogenic vascular endothelial growth factor

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Ok-Nam [College of Pharmacy, Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan 426-791 (Korea, Republic of); Ahn, Seyeon; Jin, Sun Hee; Hong, Soo Hyun; Lee, Jinyoung [College of Pharmacy, Natural Products Research Institute, Seoul National University, Seoul 151-742 (Korea, Republic of); Kim, Eun-Sun [College of Pharmacy, Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan 426-791 (Korea, Republic of); Jeong, Tae Cheon [College of Pharmacy, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Chun, Young-Jin [College of Pharmacy, Chung-Ang University, Seoul 156-756 (Korea, Republic of); Lee, Ai-Young, E-mail: leeay@duih.org [Department of Dermatology, Dongguk University Ilsan Hospital, Goyang 410-773 (Korea, Republic of); Noh, Minsoo, E-mail: minsoo@alum.mit.edu [College of Pharmacy, Natural Products Research Institute, Seoul National University, Seoul 151-742 (Korea, Republic of)

    2015-03-01

    keratinocytes (NHKs). • Chemical allergens stimulate NHKs to produce VEGF. • VEGF production is preceded by IL-8 production in NHKs. • IFNγ, DNCB and formaldehyde increase lymphangiogenic VEGF-C gene transcription. • VEGF production in NHKs may be a biomarker for the prediction of potential contact allergens.

  5. Chemical allergens stimulate human epidermal keratinocytes to produce lymphangiogenic vascular endothelial growth factor

    International Nuclear Information System (INIS)

    Bae, Ok-Nam; Ahn, Seyeon; Jin, Sun Hee; Hong, Soo Hyun; Lee, Jinyoung; Kim, Eun-Sun; Jeong, Tae Cheon; Chun, Young-Jin; Lee, Ai-Young; Noh, Minsoo

    2015-01-01

    keratinocytes (NHKs). • Chemical allergens stimulate NHKs to produce VEGF. • VEGF production is preceded by IL-8 production in NHKs. • IFNγ, DNCB and formaldehyde increase lymphangiogenic VEGF-C gene transcription. • VEGF production in NHKs may be a biomarker for the prediction of potential contact allergens

  6. Chemical fingerprint technique and its application in the ...

    African Journals Online (AJOL)

    The Gastrodia tuber and its active component, gastrodin, have many pharmacological effects. In this study, optimized high performance liquid chromatography (HPLC) parameters were employed to determine the chemical fingerprints and gastrodin content of nine Gastrodia tuber populations. Based on the degree of ...

  7. Silicon doping techniques using chemical vapor dopant deposition

    NARCIS (Netherlands)

    Popadic, M.

    2009-01-01

    Ultrashallow junctions are essential for the achievement of superior transistor performance, both in MOSFET and bipolar transistors. The stringent demands require state-of-the-art fabrication techniques. At the same time, in a different context, the accurate fabrication of various n type doping

  8. Cardiovascular responses to chemical stimulation of the hypothalamic arcuate nucleus in the rat: role of the hypothalamic paraventricular nucleus.

    Directory of Open Access Journals (Sweden)

    Tetsuya Kawabe

    Full Text Available The mechanism of cardiovascular responses to chemical stimulation of the hypothalamic arcuate nucleus (ARCN was studied in urethane-anesthetized adult male Wistar rats. At the baseline mean arterial pressure (BLMAP close to normal, ARCN stimulation elicited decreases in MAP and sympathetic nerve activity (SNA. The decreases in MAP elicited by ARCN stimulation were attenuated by either gamma-aminobutyric acid (GABA, neuropeptide Y (NPY, or beta-endorphin receptor blockade in the ipsilateral hypothalamic paraventricular nucleus (PVN. Combined blockade of GABA-A, NPY1 and opioid receptors in the ipsilateral PVN converted the decreases in MAP and SNA to increases in these variables. Conversion of inhibitory effects on the MAP and SNA to excitatory effects following ARCN stimulation was also observed when the BLMAP was decreased to below normal levels by an infusion of sodium nitroprusside. The pressor and tachycardic responses to ARCN stimulation at below normal BLMAP were attenuated by blockade of melanocortin 3/4 (MC3/4 receptors in the ipsilateral PVN. Unilateral blockade of GABA-A receptors in the ARCN increased the BLMAP and heart rate (HR revealing tonic inhibition of the excitatory neurons in the ARCN. ARCN stimulation elicited tachycardia regardless of the level of BLMAP. ARCN neurons projecting to the PVN were immunoreactive for glutamic acid decarboxylase 67 (GAD67, NPY, and beta-endorphin. These results indicated that: 1 at normal BLMAP, decreases in MAP and SNA induced by ARCN stimulation were mediated via GABA-A, NPY1 and opioid receptors in the PVN, 2 lowering of BLMAP converted decreases in MAP following ARCN stimulation to increases in MAP, and 3 at below normal BLMAP, increases in MAP and HR induced by ARCN stimulation were mediated via MC3/4 receptors in the PVN. These results provide a base for future studies to explore the role of ARCN in cardiovascular diseases.

  9. Rovibrational controlled-NOT gates using optimized stimulated Raman adiabatic passage techniques and optimal control theory

    International Nuclear Information System (INIS)

    Sugny, D.; Bomble, L.; Ribeyre, T.; Dulieu, O.; Desouter-Lecomte, M.

    2009-01-01

    Implementation of quantum controlled-NOT (CNOT) gates in realistic molecular systems is studied using stimulated Raman adiabatic passage (STIRAP) techniques optimized in the time domain by genetic algorithms or coupled with optimal control theory. In the first case, with an adiabatic solution (a series of STIRAP processes) as starting point, we optimize in the time domain different parameters of the pulses to obtain a high fidelity in two realistic cases under consideration. A two-qubit CNOT gate constructed from different assignments in rovibrational states is considered in diatomic (NaCs) or polyatomic (SCCl 2 ) molecules. The difficulty of encoding logical states in pure rotational states with STIRAP processes is illustrated. In such circumstances, the gate can be implemented by optimal control theory and the STIRAP sequence can then be used as an interesting trial field. We discuss the relative merits of the two methods for rovibrational computing (structure of the control field, duration of the control, and efficiency of the optimization).

  10. Laser Stimulated Genomic Exchange in Stem Cells. Laser Non-cloning Techniques

    Science.gov (United States)

    Stefan, V. Alexander

    2012-02-01

    I propose a novel technique for a pluripotent stem cell generation. Genomic exchange is stimulated by the beat-wave free electron laser, (B-W FEL), frequency matching with the frequencies of the DNAootnotetextJ.D. Watson and F. H. C. Crick, Nature, 171, 737-738 (1953). eigen-oscillations. B-W FEL-1ootnotetextV. Stefan, B.I.Cohen, C. Joshi Science, 243,4890, (Jan 27,1989); Stefan, et al., Bull. APS. 32, No. 9, 1713 (1987); Stefan, APS March-2011, #S1.143; APS- March-2009, #K1.276. scans entire stem cell; B-W FEL-2 probes the chromosomes. The scanning and probing lasers: 300-500nm and 100-300nm, respectively; irradiances: the order-of-10s mW/cm^2 (above the threshold value for a particular gene structure); repetition rate of few-100s Hz. A variety of genetic-matching conditions can be arranged. Genomic glitches, (the cell nucleus transferootnotetextScott Noggle et al. Nature, 478, 70-75 (06 October 2011).), can be hedged by the use of lasers.

  11. Recent Microextraction Techniques for Determination and Chemical Speciation of Selenium

    Directory of Open Access Journals (Sweden)

    Ibrahim Ahmed S. A.

    2017-05-01

    Full Text Available Research designed to improve extraction has led to the development of microextraction techniques (ME, which involve simple, low cost, and effective preconcentrationof analytes in various matrices. This review is concerned with the principles and theoretical background of ME, as well as the development of applications for selenium analysis during the period from 2008 to 2016. Among all ME, dispersive liquid-liquid microextraction was found to be most favorable for selenium. On the other hand, atomic absorption spectrometry was the most frequently used instrumentation. Selenium ME have rarely been coupled to spectrophotometry and X-ray spectrophotometry methods, and there is no published application of ME with electrochemical techniques. We strongly support the idea of using a double preconcentration process, which consists of microextraction prior to preconcentration, followed by selenium determination using cathodic stripping voltammetry (ME-CSV. More attention should focus on the development of accurate, precise, and green methods for selenium analysis.

  12. Development of optical techniques for chemical engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Lamadie, F.; Charton, S.; Langlard, M. de; Ouattara, M.; Sentis, M. [CEA, Centre de Marcoule, DEN,DTEC,SGCS, F-30207 Marcoule (France)

    2016-07-01

    The design of separation processes for nuclear spend fuel treatment, dedicated to either research studies or industrial applications, is currently based on a phenomenological approach, relying on Computational Fluid Dynamics, and complemented by validation tests performed at small-scale. Indeed, most of the steps of the Purex process involve multiphasic flows (dissolution, leaching, liquid-liquid extraction, precipitation, filtration, etc.). Therefore an accurate knowledge of the dispersed phase properties is required in order to assess their coupling with the flow features, to predict the process performance and efficiency and to achieve size reduction or extrapolation. Hence, the measurements of particulate flows properties, and especially the particles (or drops or bubbles) size distribution, concentration (i.e. hold-up) and velocity has become a growing issue. Relevant techniques for measuring these flow properties are multiple, from the high-speed video acquisition coupled to image processing to the laser-induced fluorescence, including the particle imaging velocimetry or interferometric techniques (digital in-line holography, rainbow refractometry, etc.). In this communication, different techniques developed at CEA Marcoule for the characterization of multiphase flows, will be introduced. The strong interaction with computational fluid dynamics, in the scope of a multi-scale approach, will be discussed through typical results of gas-liquid, liquid-liquid and solid-liquid flows possibly encountered in nuclear fuel reprocessing process. (authors)

  13. Application of physical and chemical characterization techniques to metallic powders

    International Nuclear Information System (INIS)

    Slotwinski, J. A.; Watson, S. S.; Stutzman, P. E.; Ferraris, C. F.; Peltz, M. A.; Garboczi, E. J.

    2014-01-01

    Systematic studies have been carried out on two different powder materials used for additive manufacturing: stainless steel and cobalt-chrome. The characterization of these powders is important in NIST efforts to develop appropriate measurements and standards for additive materials and to document the property of powders used in a NIST-led additive manufacturing material round robin. An extensive array of characterization techniques was applied to these two powders, in both virgin and recycled states. The physical techniques included laser diffraction particle size analysis, X-ray computed tomography for size and shape analysis, and optical and scanning electron microscopy. Techniques sensitive to chemistry, including X-ray diffraction and energy dispersive analytical X-ray analysis using the X-rays generated during scanning electron microscopy, were also employed. Results of these analyses will be used to shed light on the question: how does virgin powder change after being exposed to and recycled from one or more additive manufacturing build cycles? In addition, these findings can give insight into the actual additive manufacturing process

  14. Investigation of the chemical composition-changes in horticultural plants as a function of x-ray stimulation doses

    International Nuclear Information System (INIS)

    Szabo, A.S.; Tejeda, M.A.J.

    1989-01-01

    In the low dose experiments of radish, lettuce, tomato, paprika, pea and bean the presowing stimulation does not influence the chemical parameters (e.g. protein, fat, fibre, ash, macro and trace elements) of the edible parts of the plants. Stimulation has a favourable effect on vitamin C content of the horticultural vegetables. The irradiation of the seeds was performed using 5-15 Gy dose and a mobile X-ray generator, GIGANT-18, with dose of 2 Gy/min. (author) 11 refs.; 3 tabs

  15. Techniques for chemical characterization of zirconium and its alloys

    International Nuclear Information System (INIS)

    Iyer, K.V.; Bassan, M.K.T.; Sudersanan, M.

    2002-01-01

    Chemical characterization of zirconium and its alloys such as zircaloy, Zr-Nb, etc for minor and trace constituents like Nb, Ti, Fe, Cr, Ni, Sn, Al etc has been carried out. Zirconium, being a major constituent, has been determined by gravimetry as zirconium oxide while other constituents like Nb, Ti, Fe have been determined by spectrophotometric methods. Other metals of importance at trace level have been estimated by AAS or ICPAES. The judicious use of both conventional and modern instrumental methods of analysis helps in the characterization of zirconium and its alloys for various major and minor constituents. The role of matrix effect in the determination was also investigated and methods have been worked out based on a preliminary separation of zirconium by a hydroxide precipitation. (author)

  16. Optically stimulated luminescence techniques in retrospective dosimetry using single grains of quartz extracted from unheated materials

    Energy Technology Data Exchange (ETDEWEB)

    Joerkov Thomsen, Kristina

    2004-02-01

    This work investigates the possibility of applying optically stimulated luminescence (OSL) in retrospective dose determinations using unheated materials. It focuses on identifying materials suitable for use in assessment of doses absorbed as a consequence of radiation accidents (i.e. accident dosimetry). Special attention has been paid to quartz extracted from unheated building materials such as concrete and mortar. The single-aliquot regeneration-dose (SAR) protocol has been used to determine absorbed doses in small aliquots as well as single grains of quartz. It is shown that OSL measurements of single grains of quartz extracted from poorly-bleached building materials can provide useful information on radiation accident doses, even when the luminescence sensitivity is low. Sources of variance in well-bleached single grain dose distributions have been investigated in detail and it is concluded that the observed variability in the data is consistent with the sum (in quadrature) of a component, which depends on the number of photons detected from each grain, and a fixed component independent of light level. Dose depth profiles through laboratory irradiated concrete bricks have successfully been measured and minimum detection limits of less than 100 mGy are derived. Measurements of thermal transfer in single grains of poorly-bleached quartz show that thermal transfer is variable on a grain-to-grain basis and that it can be a source of variance in single-grain dose distributions. Furthermore, the potential of using common household and workplace chemicals, such as table salt, washing powder and water softener, in retrospective dosimetry has been investigated. It is concluded that such materials should be considered as retrospective dosimeters in the event of a radiation accident. (au)

  17. A chemically inert drug can stimulate T cells in vitro by their T cell receptor in non-sensitised individuals

    International Nuclear Information System (INIS)

    Engler, Olivier B.; Strasser, Ingrid; Naisbitt, Dean J.; Cerny, Andreas; Pichler, Werner J.

    2004-01-01

    Drugs can interact with T cell receptors (TCR) after binding to peptide-MHC structures. This binding may involve the formation of a stable, covalent bond between a chemically reactive drug and MHC or the peptide embedded within. Alternatively, if the drug is chemically inert, the binding may be non-covalent and readily reversible. Both types of drug presentation account for a substantial number of adverse side effects to drugs. Presently no tests are available to predict the ability of chemically inert drugs to stimulate an immune response. Here we present data on the successful induction of a primary T cell immune response in vitro against a chemically inert drug using blood from healthy individuals, previously not exposed to the drug. Blood lymphocytes were stimulated by the chemically inert drug sulfamethoxazole and the protein-reactive drug-metabolite sulfamethoxazole-nitroso in the presence of IL-2. 9/10 individuals reacted in response to sulfamethoxazole-nitroso, but only three reacted to the chemically inert compound sulfamethoxazole. Drug reactive T cells could be detected after 14-35 days of cell culture by drug-specific proliferation or cytotoxicity, which was MHC-restricted. These cells were CD4, CD8 positive or CD4/CD8 double positive and T cell clones generated secreted Th0 type cytokines. Drug interaction lead to down-regulation of specific TCR. These data confirm the ability of chemically inert drugs to stimulate certain T cells by their TCR and may provide the opportunity to screen new drugs for their ability to interact with TCRs

  18. Involvement of Subcortical Brain Structures During Olfactory Stimulation in Multiple Chemical Sensitivity.

    Science.gov (United States)

    Alessandrini, Marco; Micarelli, Alessandro; Chiaravalloti, Agostino; Bruno, Ernesto; Danieli, Roberta; Pierantozzi, Mariangela; Genovesi, Giuseppe; Öberg, Johanna; Pagani, Marco; Schillaci, Orazio

    2016-03-01

    Multiple chemical sensitivity (MCS) patients usually react to odour compounds and the majority of neuroimaging studies assessed, especially at the cortical level, many olfactory-related correlates. The purpose of the present study was to depict sub-cortical metabolic changes during a neutral (NC) and pure (OC) olfactory stimulation by using a recently validated (18)F-2-fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography/computer tomography procedure in 26 MCS and 11 healthy (HC) resting subjects undergoing a battery of clinical tests. Twelve subcortical volumes of interest were identified by the automated anatomical labeling library and normalized to thalamus FDG uptake. In both groups, when comparing OC to NC, the within-subjects ANOVA demonstrated a relative decreased metabolism in bilateral putamen and hippocampus and a relative increased metabolism in bilateral amygdala, olfactory cortex (OLF), caudate and pallidum. The between-groups ANOVA demonstrated in MCS a significant higher metabolism in bilateral OLF during NC. As in HC subjects negative correlations were found in OC between FDG uptake in bilateral amygdala and hippocampus and odor pleasantness scale, the latter positively correlated with MCS subjects' bilateral putamen FDG uptake in OC. Besides FDG uptake resemblances in both groups were found, for the first time a relative higher metabolism increase in OLF in MCS subjects at rest with respect to HC was found. When merging this aspect to the different subcortical FDG uptake correlations patterns in the two groups, the present study demonstrated to describe a peculiar metabolic index of behavioral and neurological aspects of MCS complaints.

  19. Comparison of chemical restraint techniques in ostrich (Struthio camelus

    Directory of Open Access Journals (Sweden)

    R Ciboto

    2006-06-01

    Full Text Available Chemical restraint in ostriches is usually required for short-time interventions. Thus, this study established and evaluated intravenous anesthetics formulated from commonly used drugs in order to accomplish total restraint on this species and allow painful procedures to be performed. Thirty male and female ostriches weighing from 40 to 90 kg were randomly distributed into five groups. Animals in Groups I, II and III were given acepromazine (0.25 mg/kg i.m. and those in Groups IV and V were given xylazine (1.0 mg/kg i.m.. The following drugs were administered intravenously 15 to 20 min later: Group I - propofol (4.0 mg/kg, Groups II and IV - ketamine (5.0 mg/kg and diazepam (0.25 mg/kg, Groups III and V - tiletamine-zolazepam (3.0 mg/kg. All protocols have produced satisfactory results regarding total containment, muscular relaxation and maintenance of the evaluated parameters within a normal range.

  20. Chemical reaction on solid surface observed through isotope tracer technique

    International Nuclear Information System (INIS)

    Tanaka, Ken-ichi

    1983-01-01

    In order to know the role of atoms and ions on solid surfaces as the partners participating in elementary processes, the literatures related to the isomerization and hydrogen exchanging reaction of olefines, the hydrogenation of olefines, the metathesis reaction and homologation of olefines based on solid catalysts were reviewed. Various olefines, of which the hydrogen atoms were substituted with deuterium at desired positions, were reacted using various solid catalysts such as ZnO, K 2 CO 3 on C, MoS 2 (single crystal and powder) and molybdenum oxide (with various carriers), and the infra-red spectra of adsorbed olefines on catalysts, the isotope composition of reaction products and the production rate of the reaction products were measured. From the results, the bonding mode of reactant with the atoms and ions on solid surfaces, and the mechanism of the elementary process were considered. The author emphasized that the mechanism of the chemical reaction on solid surfaces and the role of active points or catalysts can be made clear to the considerable extent by combining isotopes suitably. (Yoshitake, I.)

  1. Application of nonliner reduction techniques in chemical process modeling: a review

    International Nuclear Information System (INIS)

    Muhaimin, Z; Aziz, N.; Abd Shukor, S.R.

    2006-01-01

    Model reduction techniques have been used widely in engineering fields for electrical, mechanical as well as chemical engineering. The basic idea of reduction technique is to replace the original system by an approximating system with much smaller state-space dimension. A reduced order model is more beneficial to process and industrial field in terms of control purposes. This paper is to provide a review on application of nonlinear reduction techniques in chemical processes. The advantages and disadvantages of each technique reviewed are also highlighted

  2. Optically stimulated luminescence of ZnO obtained by thermal treatment of ZnS chemically synthesized

    International Nuclear Information System (INIS)

    Cruz V, C.; Burruel I, S.E.; Orante B, V.R.; Grijalva M, H.; Perez S, R.; Bernal, R.

    2005-01-01

    In this work, we report the optically stimulated luminescence (OSL) dosimetry of new nano phosphors of ZnO obtained by thermal annealing of chemically synthesized ZnS powder. The synthesized ZnS nano powder was compressed in order to form pellet shaped pellets, which were afterwards subjected to a thermal annealing at 700 C during 24 h under air atmosphere. X-ray diffraction (XRD) patterns and energy-disperse X-ray Spectrometry (EDS) analyses confirmed the transformation of ZnS to ZnO. Samples were exposed to several doses of beta radiation up to 600 Gy, and the optically stimulated luminescence with 470 nm wavelength light was recorded as a function of dose. The intensity of the OSL signal increases by increasing dose, for what it is concluded that these new phosphor materials are suitable to be used in optically stimulated luminescence dosimetry. (Author)

  3. Swept frequency acoustic interferometry technique for chemical weapons verification and monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, D.N.; Anthony, B.W.; Lizon, D.C.

    1995-03-01

    Nondestructive evaluation (NDE) techniques are important for rapid on-site verification and monitoring of chemical munitions, such as artillery shells and bulk containers. Present NDE techniques provide only limited characterizations of such munitions. This paper describes the development of a novel noninvasive technique, swept-frequency acoustic interferometry (SFAI), that significantly enhances the capability of munitions characterizations. The SFAI technique allows very accurate and simultaneous determination of sound velocity and attenuation of chemical agents over a large frequency range inside artillery shells, in addition to determining agent density. The frequency-dependent sound velocity and attenuation can, in principle, provide molecular relaxation properties of the chemical agent. The same instrument also enables a direct fill-level measurement in bulk containers. Industrial and other applications of this general-purpose technique are also discussed.

  4. Conditioning stimulation techniques for enhancement of transcranially elicited evoked motor responses

    NARCIS (Netherlands)

    Journee, H. -L.; Polak, H. E.; De Kleuver, M.

    2007-01-01

    Introduction. - In spite of the use of multipulse, transcranial electrical stimulation (TES) is still insufficient in a subgroup of patients to elicit motor-evoked potentials during intraoperative neurophysiological monitoring (IONM). Classic facilitation methods used in awake patients are precluded

  5. Postoperative Displacement of Deep Brain Stimulation Electrodes Related to Lead-Anchoring Technique

    NARCIS (Netherlands)

    Contarino, M. Fiorella; Bot, Maarten; Speelman, Johannes D.; de Bie, Rob M. A.; Tijssen, Marina A.; Denys, Damiaan; Bour, Lo J.; Schuurman, P. Richard; van den Munckhof, Pepijn

    2013-01-01

    BACKGROUND: Displacement of deep brain stimulation (DBS) electrodes may occur after surgery, especially due to large subdural air collections, but other factors might contribute. OBJECTIVE: To investigate factors potentially contributing to postoperative electrode displacement, in particular,

  6. Chemical profiling with cytokine stimulating investigations of Sutherlandia frutescens L.R. (Br.) (Fabaceae)

    CSIR Research Space (South Africa)

    Faleschini, MT

    2013-03-01

    Full Text Available gave the best performance in recruiting various inflammatory cytokines to the site of infection upon stimulation with phorbol 12-myristate 13-acetate, where essentially the non-polar compounds present in the ethanol extract contributed to most...

  7. Non-invasive and non-chemical method of stimulating the brain and ...

    African Journals Online (AJOL)

    Locomotor activity in normal rats, measured for 10 seconds, averaged 10.1±4.1 ... method of stimulating the CNS and increasing its levels of catecholamines. ... Keywords: Hypermotility, Noradrenergic pathway, Diazepam, GABA Receptors

  8. Scanning angle Raman spectroscopy: Investigation of Raman scatter enhancement techniques for chemical analysis

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Matthew W. [Iowa State Univ., Ames, IA (United States)

    2013-01-01

    This thesis outlines advancements in Raman scatter enhancement techniques by applying evanescent fields, standing-waves (waveguides) and surface enhancements to increase the generated mean square electric field, which is directly related to the intensity of Raman scattering. These techniques are accomplished by employing scanning angle Raman spectroscopy and surface enhanced Raman spectroscopy. A 1064 nm multichannel Raman spectrometer is discussed for chemical analysis of lignin. Extending dispersive multichannel Raman spectroscopy to 1064 nm reduces the fluorescence interference that can mask the weaker Raman scattering. Overall, these techniques help address the major obstacles in Raman spectroscopy for chemical analysis, which include the inherently weak Raman cross section and susceptibility to fluorescence interference.

  9. Efficacy of bone marrow-stimulating technique in rotator cuff repair.

    Science.gov (United States)

    Bilsel, Kerem; Yildiz, Fatih; Kapicioglu, Mehmet; Uzer, Gokcer; Elmadag, Mehmet; Pulatkan, Anil; Esrefoglu, Mukaddes; Bozdag, Ergun; Milano, Giuseppe

    2017-08-01

    This study used a chronic rotator cuff (RC) tear model to investigate the effect of microfracture as a bone marrow-stimulating (BMS) technique for RC healing. A chronic retracted RC tendon tear model was created bilaterally in the subscapularis tendons of 20 New Zealand rabbits. The tendons were repaired after 8 weeks using a single-row configuration. Tendons in the right shoulder were repaired in standard fashion (control group). Microfractures were performed in the left shoulders before repair (microfracture group). The animals were euthanized 8 and 16 weeks after repair. The repaired tendons were tested biomechanically for their ultimate failure load, linear stiffness, and elongation at failure. Gross and histologic evaluations of the tendon-to-bone healing were evaluated. Macroscopically, subscapularis tendons were attached on the lesser tuberosity. In the microfracture group, collagen fibers were organized in relatively thicker bundles. The mean ultimate failure load of the microfracture group was significantly greater at 8 weeks (148.4 ± 31 N vs. 101.4 ± 26 N, respectively; P = .011) and 16 weeks (155 ± 30 N vs. 114.9 ± 25 N, respectively; P = .017) after repair. There were no significant differences between the groups for linear stiffness at 8 weeks (15.9 ± 2.7 N/mm vs. 15.8 ± 1.3 N/mm, respectively; P = .798) and 16 weeks (16.9 ± 4.3 N/mm vs. 17.1 ± 3.6 N/mm, respectively, P = .848) and elongation at failure at 8 weeks (4.7 ± 1.1 mm vs. 4.7 ± 1.3 mm, respectively; P = .848) and 16 weels (4.8 ± 1.5 mm vs. 4.9 ± 0.9 mm, respectively; P = .749). The microfracture on the tuberosity of the repaired chronic rotator cuff tear promoted dynamic tendon healing with significantly increased ultimate force to failure and with thicker collagen bundles and more fibrocartilage histologically at 8 weeks. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of

  10. Control charts technique - a tool to data analysis for chemical experiments

    International Nuclear Information System (INIS)

    Yadav, M.B.; Venugopal, V.

    1999-01-01

    A procedure using control charts technique has been developed to analyse data of a chemical experiment which was conducted to assign a value to uranium content in Rb 2 U(SO 4 ) 3 . A value of (34.164 ± 0.031)% has been assigned against (34.167 ± 0.042)% already assigned by analysis of variance (ANOVA) technique. These values do not differ significantly. Merits and demerits of the two techniques have been discussed. (author)

  11. Analytical study of nonlinear phase shift through stimulated Brillouin scattering in single mode fiber with the pump power recycling technique

    International Nuclear Information System (INIS)

    Al-Asadi, H A; Mahdi, M A; Bakar, A A A; Adikan, F R Mahamd

    2011-01-01

    We present a theoretical study of nonlinear phase shift through stimulated Brillouin scattering in single mode optical fiber. Analytical expressions describing the nonlinear phase shift for the pump and Stokes waves in the pump power recycling technique have been derived. The dependence of the nonlinear phase shift on the optical fiber length, the reflectivity of the optical mirror and the frequency detuning coefficient have been analyzed for different input pump power values. We found that with the recycling pump technique, the nonlinear phase shift due to stimulated Brillouin scattering reduced to less than 0.1 rad for 5 km optical fiber length and 0.65 reflectivity of the optical mirror, respectively, at an input pump power equal to 30 mW

  12. Medium scale test study of chemical cleaning technique for secondary side of SG in PWR

    International Nuclear Information System (INIS)

    Zhang Mengqin; Zhang Shufeng; Yu Jinghua; Hou Shufeng

    1997-08-01

    The medium scale test study of chemical cleaning technique for removing corrosion product (Fe 3 O 4 ) in secondary side of SG in PWR has been completed. The test has been carried out in a medium scale test loop. The medium scale test evaluated the effect of the chemical cleaning technique (temperature, flow rate, cleaning time, cleaning process), the state of corrosion product deposition on magnetite (Fe 3 O 4 ) solubility and safety of materials of SG in cleaning process. The inhibitor component of chemical cleaning agent has been improved by electrochemical linear polarization method, the effect of inhibitor on corrosion resistance of materials have been examined in the medium scale test loop, the most components of chemical cleaning agent have been obtained, the EDTA is main component in cleaning agent. The electrochemical method for monitor corrosion of materials during cleaning process has been completed in the laboratory. The study of the medium scale test of chemical cleaning technique have had the optimum chemical cleaning technique for remove corrosion product in SG secondary side of PWR. (9 refs., 4 figs., 11 tabs.)

  13. Cortical activity during olfactory stimulation in multiple chemical sensitivity: a 18F-FDG PET/CT study

    International Nuclear Information System (INIS)

    Chiaravalloti, Agostino; Di Pietro, Barbara; Pagani, Marco; Micarelli, Alessandro; Alessandrini, Marco; Genovesi, Giuseppe; Schillaci, Orazio

    2015-01-01

    To investigate the differences in brain glucose consumption during olfactory stimulation between subjects affected by multiple chemical sensitivity (MCS) and a group of healthy individuals. Two 18 F-FDG PET/CT scans were performed in 26 subjects (6 men and 20 women; mean age 46.7 ± 11 years) with a clinical diagnosis of MCS and in 11 healthy controls (6 women and 5 men; mean age 45.7 ± 11 years), the first scan after a neutral olfactory stimulation (NS) and the second after a pure olfactory stimulation (OS). Differences in 18 F-FDG uptake were analysed by statistical parametric mapping (SPM2). In controls OS led to an increase in glucose consumption in BA 18 and 19 and a reduction in glucose metabolism in BA 10, 11, 32 and 47. In MCS subjects, OS led to an increase in glucose consumption in BA 20, 23, 18 and 37 and a reduction in glucose metabolism in BA 8, 9 and 10. The results of our study suggest that cortical activity in subjects with MCS differs from that in healthy individuals during olfactory stimulation. (orig.)

  14. Cortical activity during olfactory stimulation in multiple chemical sensitivity: a {sup 18}F-FDG PET/CT study

    Energy Technology Data Exchange (ETDEWEB)

    Chiaravalloti, Agostino; Di Pietro, Barbara [University Tor Vergata, Department of Biomedicine and Prevention, Rome (Italy); Pagani, Marco [Institute of Cognitive Sciences and Technologies, CNR, Rome (Italy); Department of Nuclear Medicine Karolinska Hospital Stockholm, Stockholm (Sweden); Micarelli, Alessandro; Alessandrini, Marco [University Tor Vergata, Department of Medical Science and Translational Medicine, Rome (Italy); Genovesi, Giuseppe [University La Sapienza, Department of Experimental Medicine, Rome (Italy); University La Sapienza, Regional Center for Diagnosis, Treatment and Prevention of MCS, Rome (Italy); Schillaci, Orazio [University Tor Vergata, Department of Biomedicine and Prevention, Rome (Italy); IRCCS Neuromed, Pozzilli (Italy)

    2015-04-01

    To investigate the differences in brain glucose consumption during olfactory stimulation between subjects affected by multiple chemical sensitivity (MCS) and a group of healthy individuals. Two {sup 18}F-FDG PET/CT scans were performed in 26 subjects (6 men and 20 women; mean age 46.7 ± 11 years) with a clinical diagnosis of MCS and in 11 healthy controls (6 women and 5 men; mean age 45.7 ± 11 years), the first scan after a neutral olfactory stimulation (NS) and the second after a pure olfactory stimulation (OS). Differences in {sup 18}F-FDG uptake were analysed by statistical parametric mapping (SPM2). In controls OS led to an increase in glucose consumption in BA 18 and 19 and a reduction in glucose metabolism in BA 10, 11, 32 and 47. In MCS subjects, OS led to an increase in glucose consumption in BA 20, 23, 18 and 37 and a reduction in glucose metabolism in BA 8, 9 and 10. The results of our study suggest that cortical activity in subjects with MCS differs from that in healthy individuals during olfactory stimulation. (orig.)

  15. Cortical activity during olfactory stimulation in multiple chemical sensitivity: a (18)F-FDG PET/CT study.

    Science.gov (United States)

    Chiaravalloti, Agostino; Pagani, Marco; Micarelli, Alessandro; Di Pietro, Barbara; Genovesi, Giuseppe; Alessandrini, Marco; Schillaci, Orazio

    2015-04-01

    To investigate the differences in brain glucose consumption during olfactory stimulation between subjects affected by multiple chemical sensitivity (MCS) and a group of healthy individuals. Two (18)F-FDG PET/CT scans were performed in 26 subjects (6 men and 20 women; mean age 46.7 ± 11 years) with a clinical diagnosis of MCS and in 11 healthy controls (6 women and 5 men; mean age 45.7 ± 11 years), the first scan after a neutral olfactory stimulation (NS) and the second after a pure olfactory stimulation (OS). Differences in (18)F-FDG uptake were analysed by statistical parametric mapping (SPM2). In controls OS led to an increase in glucose consumption in BA 18 and 19 and a reduction in glucose metabolism in BA 10, 11, 32 and 47. In MCS subjects, OS led to an increase in glucose consumption in BA 20, 23, 18 and 37 and a reduction in glucose metabolism in BA 8, 9 and 10. The results of our study suggest that cortical activity in subjects with MCS differs from that in healthy individuals during olfactory stimulation.

  16. Effects of stimulation technique, anatomical region and time on human sweat lipid mediator profiles.

    Science.gov (United States)

    Few studies compare sampling protocol effect on sweat composition. Here we evaluate the impact of sweat stimulation mode and site of collection on lipid mediator composition. Sweat from healthy males (n = 7) was collected weekly for three weeks from the volar forearm following either pilocarpine ion...

  17. A fast simulation tool for evaluation of novel well stimulation techniques for tight gas reservoirs

    NARCIS (Netherlands)

    Egberts, P.J.P.; Peters, E.

    2015-01-01

    For stimulation of tight fields, alternatives to hydraulic fracturing based on hydraulic jetting are becoming available. With hydraulic jetting many (10 to 20) laterals can be created in a (sub-) vertical well. The laterals are 100 to 200 m long, typically 4 laterals are applied with a small

  18. Techniques for SMM/THz Chemical Analysis: Investigations and Exploitation of the Large Molecule Limit

    Science.gov (United States)

    2014-03-03

    SECURITY CLASSIFICATION OF: It has long been recognized that the SMM /THz has a unique combinations of attributes that make it attractive as a basis for...applicability of SMM chemical sensors; the second is to explore infrared – SMM double resonance as a basis for atmospheric remote sensing; and the third...2014 12-Aug-2009 11-Aug-2013 Approved for Public Release; Distribution Unlimited Techniques for SMM /THz Chemical Analysis: Investigations and

  19. Dosimetric methodology for extremities of individuals occupationally exposed to beta radiation using the optically stimulated luminescence technique

    International Nuclear Information System (INIS)

    Pinto, Teresa Cristina Nathan Outeiro

    2010-01-01

    A dosimetric methodology was established for the determination of extremity doses of individuals occupationally exposed to beta radiation, using Al 2 O 3 :C detectors and the optically stimulated luminescence (OSL) reader system microStar, Landauer. The main parts of the work were: characterization of the dosimetric material Al 2 O 3 :C using the OSL technique; establishment of the dose evaluation methodology; dose rate determination of beta radiation sources; application of the established method in a practical test with individuals occupationally exposed to beta radiation during a calibration simulation of clinical applicators; validation of the methodology by the comparison between the dose results of the practical test using the OSL and the thermoluminescence (TL) techniques. The results show that both the OSL Al-2O 3 :C detectors and the technique may be utilized for individual monitoring of extremities and beta radiation. (author)

  20. Lifetimes of organic photovoltaics: Combining chemical and physical characterisation techniques to study degradation mechanisms

    DEFF Research Database (Denmark)

    Norrman, K.; Larsen, N.B.; Krebs, Frederik C

    2006-01-01

    Degradation mechanisms of a photovoltaic device with an Al/C-60/C-12-PSV/PEDOT:PSS/ITO/glass geometry was studied using a combination of in-plane physical and chemical analysis techniques: TOF-SIMS, AFM, SEM, interference microscopy and fluorescence microscopy. A comparison was made between...

  1. The study of metal sulphide nanomaterials obtained by chemical bath deposition and hot-injection technique

    Science.gov (United States)

    Maraeva, E. V.; Alexandrova, O. A.; Forostyanaya, N. A.; Levitskiy, V. S.; Mazing, D. S.; Maskaeva, L. N.; Markov, V. Ph; Moshnikov, V. A.; Shupta, A. A.; Spivak, Yu M.; Tulenin, S. S.

    2015-11-01

    In this study lead sulphide - cadmium sulphide based layers were obtained through chemical deposition of water solutions and cadmium sulphide quantum dots were formed through hot-injection technique. The article discusses the results of surface investigations with the use of atomic force microscopy, Raman spectroscopy and photoluminescence measurements.

  2. The study of metal sulphide nanomaterials obtained by chemical bath deposition and hot-injection technique

    International Nuclear Information System (INIS)

    Maraeva, E V; Alexandrova, O A; Levitskiy, V S; Mazing, D S; Moshnikov, V A; Shupta, A A; Spivak, Yu M; Forostyanaya, N A; Maskaeva, L N; Markov, V Ph; Tulenin, S S

    2015-01-01

    In this study lead sulphide – cadmium sulphide based layers were obtained through chemical deposition of water solutions and cadmium sulphide quantum dots were formed through hot-injection technique. The article discusses the results of surface investigations with the use of atomic force microscopy, Raman spectroscopy and photoluminescence measurements. (paper)

  3. Systematic Review of Three Electrical Stimulation Techniques for Rehabilitation After Total Knee Arthroplasty.

    Science.gov (United States)

    Yue, Chen; Zhang, Xue; Zhu, Yingjie; Jia, Yudong; Wang, Huichao; Liu, Youwen

    2018-07-01

    The comparative effectiveness of neuromuscular electrical stimulation (NMES), transcutaneous electrical nerve stimulation (TENS), and electroacupuncture (EA) for improving patient rehabilitation following total knee arthroplasty (TKA) is controversial. Therefore we conducted this systematic review to assess the available evidence. The PubMed, OVID, and ScienceDirect databases were comprehensively searched and studies were selected and analyzed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. Data were extracted and qualitatively synthesized for several outcomes. Data were analyzed from 17 randomized controlled trials involving 1285 procedures: 8 NMES studies (608 procedures), 7 TENS studies (560 procedures), and 2 EA studies (117 procedures). Qualitative analysis suggested that NMES was associated with higher quadriceps strength and functional recovery after TKA. Recovery benefits were maximal when the stimulation was performed once or twice a day for 4-6 weeks at an intensity of 100-120 mA and frequency of 30-100 Hz. The electrode should be sufficiently large (100-200 cm 2 ) to reduce discomfort. TENS at an intensity of 15-40 mA and frequency of 70-150 Hz provided effective analgesia after TKA. EA at an intensity of 2 mA and frequency of 2 Hz may also provide postoperative analgesia of TKA. As adjunct modalities, NMES and TENS can effectively improve rehabilitation after TKA without triggering significant intolerance, and maximal benefits depend on optimized parameters and intervention protocols. EA may be an effective adjunct modality for analgesia after TKA. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. Altered Adipogenesis in Zebrafish Larvae Following High Fat Diet and Chemical Exposure Is Visualised by Stimulated Raman Scattering Microscopy

    Directory of Open Access Journals (Sweden)

    Marjo J. den Broeder

    2017-04-01

    Full Text Available Early life stage exposure to environmental chemicals may play a role in obesity by altering adipogenesis; however, robust in vivo methods to quantify these effects are lacking. The goal of this study was to analyze the effects of developmental exposure to chemicals on adipogenesis in the zebrafish (Danio rerio. We used label-free Stimulated Raman Scattering (SRS microscopy for the first time to image zebrafish adipogenesis at 15 days post fertilization (dpf and compared standard feed conditions (StF to a high fat diet (HFD or high glucose diet (HGD. We also exposed zebrafish embryos to a non-toxic concentration of tributyltin (TBT, 1 nM or Tris(1,3-dichloroisopropylphosphate (TDCiPP, 0.5 µM from 0–6 dpf and reared larvae to 15 dpf under StF. Potential molecular mechanisms of altered adipogenesis were examined by qPCR. Diet-dependent modulation of adipogenesis was observed, with HFD resulting in a threefold increase in larvae with adipocytes, compared to StF and HGD. Developmental exposure to TBT but not TDCiPP significantly increased adipocyte differentiation. The expression of adipogenic genes such as pparda, lxr and lepa was altered in response to HFD or chemicals. This study shows that SRS microscopy can be successfully applied to zebrafish to visualize and quantify adipogenesis, and is a powerful approach for identifying obesogenic chemicals in vivo.

  5. Altered Adipogenesis in Zebrafish Larvae Following High Fat Diet and Chemical Exposure Is Visualised by Stimulated Raman Scattering Microscopy

    Science.gov (United States)

    den Broeder, Marjo J.; Moester, Miriam J. B.; Kamstra, Jorke H.; Cenijn, Peter H.; Davidoiu, Valentina; Kamminga, Leonie M.; Ariese, Freek; de Boer, Johannes F.; Legler, Juliette

    2017-01-01

    Early life stage exposure to environmental chemicals may play a role in obesity by altering adipogenesis; however, robust in vivo methods to quantify these effects are lacking. The goal of this study was to analyze the effects of developmental exposure to chemicals on adipogenesis in the zebrafish (Danio rerio). We used label-free Stimulated Raman Scattering (SRS) microscopy for the first time to image zebrafish adipogenesis at 15 days post fertilization (dpf) and compared standard feed conditions (StF) to a high fat diet (HFD) or high glucose diet (HGD). We also exposed zebrafish embryos to a non-toxic concentration of tributyltin (TBT, 1 nM) or Tris(1,3-dichloroisopropyl)phosphate (TDCiPP, 0.5 µM) from 0–6 dpf and reared larvae to 15 dpf under StF. Potential molecular mechanisms of altered adipogenesis were examined by qPCR. Diet-dependent modulation of adipogenesis was observed, with HFD resulting in a threefold increase in larvae with adipocytes, compared to StF and HGD. Developmental exposure to TBT but not TDCiPP significantly increased adipocyte differentiation. The expression of adipogenic genes such as pparda, lxr and lepa was altered in response to HFD or chemicals. This study shows that SRS microscopy can be successfully applied to zebrafish to visualize and quantify adipogenesis, and is a powerful approach for identifying obesogenic chemicals in vivo. PMID:28441764

  6. Evaluating Origin of Electron Traps in Tris(8-hydroxyquinoline) Aluminum Thin Films using Thermally Stimulated Current Technique

    OpenAIRE

    Matsushima, Toshinori; Adachi, Chihaya

    2008-01-01

    We measured the energy distributions and concentrations of electron traps in O_2-unexposed and O_2-exposed tris(8-hydroxyquinoline) aluminum (Alq_3) films using a thermally stimulated current (TSC) technique to investigate how doping O_2 molecules in Alq_3 films affect the films' electron trap and electron transport characteristics. The results of our TSC studies revealed that Alq_3 films have an electron trap distribution with peak depths ranging from 0.075 to 0.1 eV and peak widths ranging ...

  7. Chemically modified tetracyclines stimulate matrix metalloproteinase-s production by periodontal ligament cells

    NARCIS (Netherlands)

    Bildt, M.M.; Snoek-van Beurden, A.M.P.; Groot, J. de; El, B. van; Kuijpers-Jagtman, A.M.; Hoff, J.W. van den

    2006-01-01

    Background and Objective: The purpose of this study was to investigate the effects of chemically modified tetracyclines (CMTs) on the production of gelatinases [matrix metalloproteinase (MMP)-2 and -9] by human periodontal ligament (PDL) cells, and on the activity of recombinant gelatinases.

  8. Studies of ground-state dynamics in isolated species by ionization-detected stimulated Raman techniques

    Energy Technology Data Exchange (ETDEWEB)

    Felker, P.M. [Univ. of California, Los Angeles (United States)

    1993-12-01

    First, the author aims to develop methods of nonlinear Raman spectroscopy for application in studies of sparse samples. Second, the author wishes to apply such methods to structural and dynamical studies of species (molecules, complexes, and clusters) in supersonic molecular beams. In the past year, the author has made progress in several areas. The first pertains to the application of mass-selective ionization-detected stimulated Raman spectroscopies (IDSRS) to the size-specific vibrational spectroscopy of solute-solvent{sub n} clusters. The second involves the application of IDSRS methods to studies of jet-cooled benzene clusters. The third pertains to the use of IDSRS methods in the study of intermolecular vibrational transitions in van der Waals complexes.

  9. Efficiency of modified chemical remediation techniques for soil contaminated by organochlorine pesticides

    Science.gov (United States)

    Correa-Torres, S. N.; Kopytko, M.; Avila, S.

    2016-07-01

    This study reports the optimization of innovation chemical techniques in order to improve the remediation of soils contaminated with organochloride pesticides. The techniques used for remediation were dehalogenation and chemical oxidation in soil contaminated by pesticides. These techniques were applied sequentially and combined to evaluate the design optimize the concentration and contact time variables. The soil of this study was collect in cotton crop zone in Agustin Codazzi municipality, Colombia, and its physical properties was measure. The modified dehalogenation technique of EPA was applied on the contaminated soil by adding Sodium Bicarbonate solution at different concentrations and rates during 4, 7 and 14 days, subsequently oxidation technique was implemented by applying a solution of KMnO4 at different concentration and reaction times. Organochlorine were detected by Gas Chromatography analysis coupled Mass Spectrometry and its removals were between 85.4- 90.0% of compounds such as 4, 4’-DDT, 4,4’-DDD, 4,4-DDE, trans-Clordane y Endrin. These results demonstrate that the technique of dehalogenation with oxidation chemistry can be used for remediation soils contaminated by organochloride pesticides.

  10. Detection of Chemical/Biological Agents and Stimulants using Quadrupole Ion Trap Mass Spectrometry

    International Nuclear Information System (INIS)

    Harmon, S.H.; Hart, K.J.; Vass, A.A.; Wise, M.B.; Wolf, D.A.

    1999-01-01

    Detection of Chemical/Biological Agents and Simulants A new detector for chemical and biological agents is being developed for the U. S. Army under the Chemical and Biological Mass Spectrometer Block II program. The CBMS Block II is designed to optimize detection of both chemical and biological agents through the use of direct sampling inlets[I], a multi- ported sampling valve and a turbo- based vacuum system to support chemical ionization. Unit mass resolution using air as the buffer gas[2] has been obtained using this design. Software to control the instrument and to analyze the data generated from the instrument has also been newly developed. Detection of chemical agents can be accomplished. using the CBMS Block II design via one of two inlets - a l/ I 6'' stainless steel sample line -Chemical Warfare Air (CW Air) or a ground probe with enclosed capillary currently in use by the US Army - CW Ground. The Block II design is capable of both electron ionization and chemical ionization. Ethanol is being used as the Cl reagent based on a study indicating best performance for the Biological Warfare (BW) detection task (31). Data showing good signal to noise for 500 pg of methyl salicylate injected into the CW Air inlet, 50 ng of dimethylmethylphosphonate exposed to the CW Ground probe and 5 ng of methyl stearate analyzed using the pyrolyzer inlet were presented. Biological agents are sampled using a ''bio-concentrator'' unit that is designed to concentrate particles in the low micron range. Particles are collected in the bottom of a quartz pyrolyzer tube. An automated injector is being developed to deliver approximately 2 pL of a methylating reagent, tetramethylamonium- hydroxide to 'the collected particles. Pyrolysis occurs by rapid heating to ca. 55OOC. Biological agents are then characterized by their fatty acid methyl ester profiles and by other biomarkers. A library of ETOH- Cl/ pyrolysis MS data of microorganisms used for a recently published study[3] has been

  11. The effect of electrical stimulation in combination with Bobath techniques in the prevention of shoulder subluxation in acute stroke patients.

    Science.gov (United States)

    Fil, Ayla; Armutlu, Kadriye; Atay, Ahmet Ozgur; Kerimoglu, Ulku; Elibol, Bulent

    2011-01-01

    To examine the efficiency of electrical stimulation in combination with Bobath techniques in the prevention of inferior and anterior shoulder subluxation in acute stroke patients. A prospective randomized controlled trial. Intensive care unit and inpatient clinics of neurology in a university hospital. Forty-eight patients with acute stroke, divided equally into control and study groups. Subjects in both groups were treated in accordance with the Bobath concept during the early hospitalization period. In addition to Bobath techniques, electrical stimulation was also applied to the supraspinatus muscle, mid and posterior portions of the deltoid muscle of patients in the study group. Two radiological methods were used to measure the horizontal, vertical and total asymmetry and vertical distance values of the shoulder joint. Motor functions of the arm were evaluated with the Motor Assessment Scale. The hospitalization period was 12.62 ± 2.24 days for the control group and 11.66 ± 1.88 days for the study group. Shoulder subluxation occurred in 9 (37.5%) subjects in the control group, whereas it was not observed in the study group. All shoulder joint displacement values were higher in the control group than in the study group (horizontal asymmetry P = 0.0001, vertical asymmetry P = 0.0001, total asymmetry P = 0.0001, vertical range P = 0.002). Application of electrical stimulation combined with the Bobath approach proved to be efficient in preventing inferior and anterior shoulder subluxation in the acute stages of stroke.

  12. A multi-technique approach to assess chemical speciation of phosphate in soils

    Science.gov (United States)

    Belchior Abdala, Dalton; Rodrigues, Marcos; Herrera, Wilfrand; Pavinato, Paulo Sergio

    2017-04-01

    Soil scientists see chemical characterization of phosphorus (e.g., chemical speciation) as a winning strategy to increase phosphorus use efficiency in agriculture, to understand the fate of applied P fertilizer in soils and to devise strategies to minimize P losses to the environment. Phosphorus (P) is majorly presented in soils as phosphate, bound to mineral components of soils such as Al-, Ca- and Fe-(hydr)oxides or associated with organic molecules, being thus generally referred to as organic phosphates. In addition, because of the turnover of P between plants and microbes, it delivers P back to soils as a mixture of species with high spatial and chemical heterogeneity, adding complexity to the determination of the P species contained in environmental samples. Therefore, due to the variety of forms that phosphate can present in soils, its precise chemical characterization can only be achieved using a set of analytical techniques. Although established methodologies (e. g., soil test P, sequential chemical fractionation, P isotherms) have been useful to subsidize information for the establishment of policies and guidelines for soil management and P fertilizers use, they have failed to provide detailed information on P chemistry and reactivity in soils in a more satisfactory manner, which are critical to predict P bioavailability to plants and loss potential to the environment. More recently, the association of wet chemistry analysis with spectroscopy and microscopy techniques has arguably represented the most successful means to chemically speciate phosphate in soils. This is because using qualitative (chemical speciation), quantitative (chemical fractionation) and spatial (microscopy) data allows for triangulation of information, thereby reducing bias and increasing validity of the results. The analysis framework that we propose in this study includes the use of (i) sequential chemical fractionation of soil P to determine the partitioning of P within the

  13. Long-Term Evaluation of Changes in Operative Technique and Hardware-Related Complications With Deep Brain Stimulation.

    Science.gov (United States)

    Falowski, Steven M; Ooi, Yinn Cher; Bakay, Roy A E

    2015-12-01

    Deep brain stimulation is the most frequent neurosurgical procedure for movement disorders. While this elective procedure carries a low-risk profile, it is not free of complications. As a new procedure, the pattern of complications changed with experience and modification of surgical technique and equipment. This review analyzes the most common hardware-related complications that may occur and techniques to avoid them. It is a retrospective review of 432 patients undergoing 1077 procedures over a 14-year period by one surgeon with emphasis on the analysis of surgical technique and the changes over time. Comparisons were made pre and postimplementation of different surgical techniques over different time periods. The epochs relate to the learning curve, new equipment, and new techniques. Overall lead revision was observed at 5.7%, extension revision at 3.2%, infection rate at 1.2%, infarct without intracerebral hemorrhage at 0.8%, and intracerebral hemorrhage at 2.5% with a permanent deficit of 0.2%. An analysis and change in surgical technique which involved isolating the lead from the skin surface at both the cranial and retro-auricular incision also demonstrated a substantial decrease in lead fracture rate and infection rate. There was no mortality. This large series of patients and long-term follow-up demonstrates that risks are very low in comparison with other neurosurgical procedures, but DBS is still an elective procedure that necessitates extensive care and precision. In a rapidly evolving field, attention to surgical technique is imperative and will keep rates of complications at a minimum. © 2015 International Neuromodulation Society.

  14. Detection irradiated shallot (Allium Cepa) and spices using technique of Photo Stimulated Luminescence (PSL)

    International Nuclear Information System (INIS)

    Noor Azianti Abd Rashid

    2012-01-01

    This study was carried out to investigate the effectiveness of Photo Stimulated Luminescence (PSL) in detecting the food that has been irradiated qualitatively and quantitatively. The samples used were onions (Allium Cepa) and spices. The shallots which are from India and Thailand was irradiated using Gamma Cell at dose of 0 kGy, 0.2 kGy, 0.4 kGy and 1.0. While for the spices, there were 10 types of spices used such as powder of paprika, parsley, turmeric, tarragon, coriander, mint leaves, basil, rosemary flower, chives and herbs mixture which was irradiated at the dose of 0 kGy and 8.7 kGy respectively. The result shows that the PSL method could differentiate samples which are irradiated and not irradiated. Even though the PSL value increases proportionally to the radiation dose, the relationship between these two means are not that clearly clarified and needed to be studied furthermore.(author)

  15. Wavelet-Based Artifact Identification and Separation Technique for EEG Signals during Galvanic Vestibular Stimulation

    Science.gov (United States)

    Adib, Mani; Cretu, Edmond

    2013-01-01

    We present a new method for removing artifacts in electroencephalography (EEG) records during Galvanic Vestibular Stimulation (GVS). The main challenge in exploiting GVS is to understand how the stimulus acts as an input to brain. We used EEG to monitor the brain and elicit the GVS reflexes. However, GVS current distribution throughout the scalp generates an artifact on EEG signals. We need to eliminate this artifact to be able to analyze the EEG signals during GVS. We propose a novel method to estimate the contribution of the GVS current in the EEG signals at each electrode by combining time-series regression methods with wavelet decomposition methods. We use wavelet transform to project the recorded EEG signal into various frequency bands and then estimate the GVS current distribution in each frequency band. The proposed method was optimized using simulated signals, and its performance was compared to well-accepted artifact removal methods such as ICA-based methods and adaptive filters. The results show that the proposed method has better performance in removing GVS artifacts, compared to the others. Using the proposed method, a higher signal to artifact ratio of −1.625 dB was achieved, which outperformed other methods such as ICA-based methods, regression methods, and adaptive filters. PMID:23956786

  16. Wavelet-Based Artifact Identification and Separation Technique for EEG Signals during Galvanic Vestibular Stimulation

    Directory of Open Access Journals (Sweden)

    Mani Adib

    2013-01-01

    Full Text Available We present a new method for removing artifacts in electroencephalography (EEG records during Galvanic Vestibular Stimulation (GVS. The main challenge in exploiting GVS is to understand how the stimulus acts as an input to brain. We used EEG to monitor the brain and elicit the GVS reflexes. However, GVS current distribution throughout the scalp generates an artifact on EEG signals. We need to eliminate this artifact to be able to analyze the EEG signals during GVS. We propose a novel method to estimate the contribution of the GVS current in the EEG signals at each electrode by combining time-series regression methods with wavelet decomposition methods. We use wavelet transform to project the recorded EEG signal into various frequency bands and then estimate the GVS current distribution in each frequency band. The proposed method was optimized using simulated signals, and its performance was compared to well-accepted artifact removal methods such as ICA-based methods and adaptive filters. The results show that the proposed method has better performance in removing GVS artifacts, compared to the others. Using the proposed method, a higher signal to artifact ratio of −1.625 dB was achieved, which outperformed other methods such as ICA-based methods, regression methods, and adaptive filters.

  17. Possible techniques for decontamination of natural gas from gas wells stimulated by a nuclear explosion

    Energy Technology Data Exchange (ETDEWEB)

    Wethington, Jr, John A [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1970-05-15

    Decontamination of the products from gas wells stimulated by nuclear explosions requires the removal of T, present as HT, CH{sub 3}T, C{sub 2}H{sub 5}T, etc., and {sup 85}Kr from the production stream. Flaring of large volumes of gas from the Gasbuggy well led to the replacement of radioactive cavity gas with inactive formation gas, but this would not be a satisfactory production procedure because it releases T and {sup 85}Kr into the atmosphere and wastes large amounts of product gas. Exchange reactions appear to offer promise for removing the tritium. For example, water or steam flowing countercurrent to tritiated gas in the presence of a suitable catalyst can participate in the exchange reactions CH{sub 3}T + H{sub 2}O {r_reversible} CH{sub 4} + HTO, HT + H{sub 2}O {r_reversible} H{sub 2} + HTO, resulting in the transfer of T from gas into water. Other possibilities for utilizing exchange reactions include exchange of the gas with ethylene glycol used in the gas dryer, with silicate rocks introduced into the gas stream, or with a countercurrent stream of NH{sub 3} or H{sub 2}S. As another approach, use of the contaminated gas for the manufacture of ammonia synthesis gas has potential for removal of both T and {sup 85}Kr. (author)

  18. Chemical allergens stimulate human epidermal keratinocytes to produce lymphangiogenic vascular endothelial growth factor.

    Science.gov (United States)

    Bae, Ok-Nam; Ahn, Seyeon; Jin, Sun Hee; Hong, Soo Hyun; Lee, Jinyoung; Kim, Eun-Sun; Jeong, Tae Cheon; Chun, Young-Jin; Lee, Ai-Young; Noh, Minsoo

    2015-03-01

    Allergic contact dermatitis (ACD) is a cell-mediated immune response that involves skin sensitization in response to contact with various allergens. Angiogenesis and lymphangiogenesis both play roles in the allergic sensitization process. Epidermal keratinocytes can produce vascular endothelial growth factor (VEGF) in response to UV irradiation and during wound healing. However, the effect of haptenic chemical allergens on the VEGF production of human keratinocytes, which is the primary contact site of toxic allergens, has not been thoroughly researched. We systematically investigated whether immune-regulatory cytokines and chemical allergens would lead to the production of VEGF in normal human keratinocytes (NHKs) in culture. VEGF production significantly increased when NHKs were treated with IFNγ, IL-1α, IL-4, IL-6, IL-17A, IL-22 or TNFα. Among the human sensitizers listed in the OECD Test Guideline (TG) 429, we found that CMI/MI, DNCB, 4-phenylenediamine, cobalt chloride, 2-mercaptobenzothiazole, citral, HCA, cinnamic alcohol, imidazolidinyl urea and nickel chloride all significantly upregulated VEGF production in NHKs. In addition, common human haptenic allergens such as avobenzone, formaldehyde and urushiol, also induced the keratinocyte-derived VEGF production. VEGF upregulation by pro-inflammatory stimuli, IFNγ, DNCB or formaldehyde is preceded by the production of IL-8, an acute inflammatory phase cytokine. Lymphangiogenic VEGF-C gene transcription was significantly increased when NHKs were treated with formaldehyde, DNCB or urushiol, while transcription of VEGF-A and VEGF-B did not change. Therefore, the chemical allergen-induced VEGF upregulation is mainly due to the increase in lymphangiogenic VEGF-C transcription in NHKs. These results suggest that keratinocyte-derived VEGF may regulate the lymphangiogenic process during the skin sensitization process of ACD. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. About chemical and biological stimulation of bioleaching of 90Sr from different types of soil

    International Nuclear Information System (INIS)

    Buravlev, E.P.; Trishin, V.V.; Svyatun, O.V.; Berlizov, A.N.; Kim, In.S.; Ivanov, V.N.

    2000-01-01

    The results of investigation carried out in the frame of international cooperation between the NASU and KOSEF on the creation of effective methods of purification of radioactively polluted soil were performed. The influence of methanogenic, surface-reducing, nitrifying and thiobacilli and also their joint activity with different chemical ingredients on bioleaching of 90 Sr from typical South Korea red soil,artificially radioactively polluted by 90 Sr, and technogenically polluted by the radionuclides from influenced zone of ChNPP was studied, The presence of the largest effect of thiobacilli on soil was shown

  20. Mortar and surface dating with Optically Stimulated Luminescence (OSL): Innovative techniques for the age determination of buildings

    International Nuclear Information System (INIS)

    Panzeri, L.

    2013-01-01

    In this work the results of a dating study on bricks and mortars using both Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) are shown. The samples came from the outside walls of the Certosa di Pavia, located in northern Italy and independently dated (XVII-XVIII century). TL dating, applied to bricks using the fine grain technique, allowed to determine the time of manufacture of the bricks (XII century), that resulted therefore re-used. To circumvent this problem the application of two innovative dating techniques, OSL surface dating and mortar dating, was attempted. The first was applied to the light-shielded surfaces of bricks and allowed to successfully determine the edification of the wall (XVII century). Mortar dating gave instead severe age overestimation: the results obtained on coarse grain quartz with the SAR technique both on multi-grains aliquots and with single-grain analyses were highly dispersed indicating an incomplete bleaching of the quartz grains. The shine-down curves were in fact characterized by the absence of the so-called fast component, as confirmed by Linear Modulated OSL technique.

  1. Performance of the In Situ Microcosm Technique for Measuring the Degradation of Organic Chemicals in Aquifers

    DEFF Research Database (Denmark)

    Nielsen, Per H.; Christensen, Thomas Højlund; Albrechtsen, Hans-Jørgen

    1996-01-01

    chemicals in polluted and pristine aquifers representing different redox environments. The ISM technique has great potential for providing field-relevant degradation potentials and rate constants, but care must be taken in using the equipment and interpreting the results. This paper provides details......An in situ microcosm (ISM) consists of a stainless steel cylinder isolating about 2 L of the aquifer and is equipped with valves allowing for loading and sampling from the ground surface. During the last five years, this technique has been used frequently to study the degradation of organic...

  2. SnS thin films deposited by chemical bath deposition, dip coating and SILAR techniques

    Science.gov (United States)

    Chaki, Sunil H.; Chaudhary, Mahesh D.; Deshpande, M. P.

    2016-05-01

    The SnS thin films were synthesized by chemical bath deposition (CBD), dip coating and successive ionic layer adsorption and reaction (SILAR) techniques. In them, the CBD thin films were deposited at two temperatures: ambient and 70 °C. The energy dispersive analysis of X-rays (EDAX), X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and optical spectroscopy techniques were used to characterize the thin films. The electrical transport properties studies on the as-deposited thin films were done by measuring the I-V characteristics, DC electrical resistivity variation with temperature and the room temperature Hall effect. The obtained results are deliberated in this paper.

  3. Advanced chemical quality control techniques for use in the manufacture of (U-Pu) MOX fuels

    International Nuclear Information System (INIS)

    Panakkal, J.P.; Prakash, Amrit

    2010-01-01

    Analytical chemistry plays a very important role for nuclear fuel cycle activities be it fuel fabrication, waste management or reprocessing. Nuclear fuels are selected based on the type of reactor. The nuclear fuel has to conform to various stringent chemical specifications like B, rare earths, H, O/M heavy metal content etc. Selection of technique is very important to determine the true specification. This is important particularly when the analyses has to be performed inside leak tight enclosure. The present paper describes the details of the advanced techniques being developed and used in the manufacture of (U,Pu) MOX fuels. (author)

  4. Roles of Ag in fabricating Si nanowires by the electroless chemical etching technique

    International Nuclear Information System (INIS)

    Wan, X.; Wang, Q. K.; Wangyang, P. H.; Tao, H.

    2012-01-01

    Silicon wafers coated with a film of Ag pattern are used for investigating roles of Ag in the fabrication of silicon nanowire arrays (SiNWs) by the electroless chemical etching technique. The diameter of SiNWs grown in the mixed AgNO 3 /HF solution ranges from 20 to 250 nm. A growth mechanism for such obtained SiNWs is proposed and further experimentally verified. As a comparison as well as to better understand this chemical process, another popular topic on growing SiNWs in the H 2 O 2 /HF solution is also studied. Originating from different chemical reaction mechanisms, Ag film could protect the underneath Si in the AgNO 3 /HF solution and it could, on the contrary, accelerate etching of the underneath Si in the H 2 O 2 /HF solution.

  5. Intralesional Osteophyte Regrowth Following Autologous Chondrocyte Implantation after Previous Treatment with Marrow Stimulation Technique.

    Science.gov (United States)

    Demange, Marco Kawamura; Minas, Tom; von Keudell, Arvind; Sodha, Sonal; Bryant, Tim; Gomoll, Andreas H

    2017-04-01

    Objective Bone marrow stimulation surgeries are frequent in the treatment of cartilage lesions. Autologous chondrocyte implantation (ACI) may be performed after failed microfracture surgery. Alterations to subchondral bone as intralesional osteophytes are commonly seen after previous microfracture and removed during ACI. There have been no reports on potential recurrence. Our purpose was to evaluate the incidence of intralesional osteophyte development in 2 cohorts: existing intralesional osteophytes and without intralesional osteophytes at the time of ACI. Study Design We identified 87 patients (157 lesions) with intralesional osteophytes among a cohort of 497 ACI patients. Osteophyte regrowth was analyzed on magnetic resonance imaging and categorized as small or large (less or more than 50% of the cartilage thickness). Twenty patients (24 defects) without intralesional osteophytes at the time of ACI acted as control. Results Osteophyte regrowth was observed in 39.5% of lesions (34.4% of small osteophytes and 5.1% of large osteophytes). In subgroup analyses, regrowth was observed in 45.8% of periosteal-covered defects and in 18.9% of collagen membrane-covered defects. Large osteophyte regrowth occurred in less than 5% in either group. Periosteal defects showed a significantly higher incidence for regrowth of small osteophytes. In the control group, intralesional osteophytes developed in 16.7% of the lesions. Conclusions Even though intralesional osteophytes may regrow after removal during ACI, most of them are small. Small osteophyte regrowth occurs almost twice in periosteum-covered ACI. Large osteophytes occur only in 5% of patients. Intralesional osteophyte formation is not significantly different in preexisting intralesional osteophytes and control groups.

  6. Recent developments of optically stimulated luminescence materials and techniques for radiation dosimetry and clinical applications

    Directory of Open Access Journals (Sweden)

    Pradhan A

    2008-01-01

    Full Text Available During the last 10 years, optically stimulated luminescence (OSL has emerged as a formidable competitor not only to thermoluminescence dosimetry (TLD but also to several other dosimetry systems. Though a large number of materials have been synthesized and studied for OSL, Al 2 O 3 :C continues to dominate the dosimetric applications. Re-investigations of OSL in BeOindicate that this material might provide an alternative to Al 2 O 3 :C. Study of OSL of electronic components of mobile phones and ID cards appears to have opened up a feasibility of dosimetry and dose reconstruction using the electronic components of gadgets of everyday use in the events of unforeseen situations of radiological accidents, including the event of a dirty bomb by terrorist groups. Among the newly reported materials, a very recent development of NaMgF 3 :Eu 2+ appears fascinating because of its high OSL sensitivity and tolerable tissue equivalence. In clinical dosimetry, an OSL as a passive dosimeter could do all that TLD can do, much faster with a better or at least the same efficiency; and in addition, it provides a possibility of repeated readout unlike TLD, in which all the dose information is lost in a single readout. Of late, OSL has also emerged as a practical real-time dosimeter for in vivo measurements in radiation therapy (for both external beams and brachytherapy and in various diagnostic radiological examinations including mammography and CT dosimetry. For in vivo measurements, a probe of Al 2 O 3 :C of size of a fraction of a millimeter provides the information on both the dose rate and the total dose from the readout of radioluminescence and OSL signals respectively, from the same probe. The availability of OSL dosimeters in various sizes and shapes and their performance characteristics as compared to established dosimeters such as plastic scintillation dosimeters, diode detectors, MOSFET detectors, radiochromic films, etc., shows that OSL may soon become

  7. Electrical and chemical stimulation of the same hypothalamic loci in relation to agressive behaviour in cats: a comparison study.

    Science.gov (United States)

    Bhatia, S C; Manchanda, S K; Kapoor, B K; Aneja, I S

    1995-10-01

    Chemitrodes which permit electrical and chemical stimulation of the same hypothalamic loci were implanted in anterior hypothalamic and preoptic regions. These sites were stimulated electrically using biphasic square wave pulse (1 ms, 60 Hz) at a current strength ranging from 150-800 microA to evoke an aggressive response. At lower current strength of 150-200 micro A, defence response, a sort of non-specific response can be elicited from these regions. Increasing the current strength to 400 microA led to the recruitment of affective and somatic components and changed the response pattern either to affective attack or flight. The loci producing affective attack response were localized more laterally and ventrally while the loci producing flight response were located in the dorsomedial regions of the hypothalamus. In this response the animal made a goal-directed attempt to escape through an escape route. Increasing the current strength to 500 microA in the dorsomedial regions changed the flight response to violent flight, which involved vigorous running with unsheathed claws and attacking objects if obstructed. Similar increase in current strength at loci producing affective attack only led to a decrease in the latency of response and made the attack more vigorous. Microinfusion of carbachol in graded doses of 2-15 microgram at all these loci produced a profound affective display. At lower doses of 2 and 5 microgram, only some components of affective display like alertness, pupillary dilation and ear flatness were exhibited. Increasing the dose to 10 micrograms and 15 micrograms led to the recruitment of other affective components like piloerection, salivation, hissing and baring of teeth. Microinfusion of carbachol at all loci producing affective attack on electrical stimulation produced a prononced affective display while microinfusion of carbachol at loci producing flight response led to the development of defence posture. At six loci a typical flight response was

  8. Compaction stimulates denitrification in an urban park soil using 15N tracing technique

    DEFF Research Database (Denmark)

    Li, Shun; Deng, Huan; Rensing, Christopher Günther T

    2014-01-01

    Soils in urban areas are subjected to compaction with accelerating urbanization. The effects of anthropogenic compaction on urban soil denitrification are largely unknown. We conducted a study on an urban park soil to investigate how compaction impacts denitrification. By using 15N labeling method...... and acetylene inhibition technique, we performed three coherent incubation experiments to quantify denitrification in compacted soil under both aerobic and anaerobic conditions. Uncompacted soil was set as the control treatment. When monitoring soil incubation without extra substrate, higher nitrous oxide (N2O......) flux and denitrification enzyme activity were observed in the compacted soil than in the uncompacted soil. In aerobic incubation with the addition of K15NO3, N2O production in the compacted soil reached 10.11 ng N h-1 g-1 as compared to 0.02 ng N h-1 g-1 in the uncompacted soil. Denitrification...

  9. Application of the optically stimulated luminescence (OSL) technique for mouse dosimetry in micro-CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Vrigneaud, Jean-Marc; Courteau, Alan; Oudot, Alexandra; Collin, Bertrand [Department of Nuclear Medicine, Centre Georges-François Leclerc, 1 rue Professeur Marion, Dijon 21079 Cedex (France); Ranouil, Julien [Landauer Europe, 33 avenue du Général Leclerc, Fontenay-aux-Roses 92266 Cedex (France); Morgand, Loïc; Raguin, Olivier [Oncodesign, 20 rue Jean Mazen, Dijon 21076 Cedex (France); Walker, Paul [LE2i CNRS UMR 5158, Faculty of Medicine, BP 87900, 21079 Dijon Cedex (France); Brunotte, François [Department of Nuclear Medicine, Centre Georges-François Leclerc, 1 rue Professeur Marion, Dijon 21079 Cedex, France and LE2i CNRS UMR 5158, Faculty of Medicine, BP 87900, 21079 Dijon Cedex (France)

    2013-12-15

    Purpose: Micro-CT is considered to be a powerful tool to investigate various models of disease on anesthetized animals. In longitudinal studies, the radiation dose delivered by the micro-CT to the same animal is a major concern as it could potentially induce spurious effects in experimental results. Optically stimulated luminescence dosimeters (OSLDs) are a relatively new kind of detector used in radiation dosimetry for medical applications. The aim of this work was to assess the dose delivered by the CT component of a micro-SPECT (single-photon emission computed tomography)/CT camera during a typical whole-body mouse study, using commercially available OSLDs based on Al{sub 2}O{sub 3}:C crystals.Methods: CTDI (computed tomography dose index) was measured in micro-CT with a properly calibrated pencil ionization chamber using a rat-like phantom (60 mm in diameter) and a mouse-like phantom (30 mm in diameter). OSLDs were checked for reproducibility and linearity in the range of doses delivered by the micro-CT. Dose measurements obtained with OSLDs were compared to those of the ionization chamber to correct for the radiation quality dependence of OSLDs in the low-kV range. Doses to tissue were then investigated in phantoms and cadavers. A 30 mm diameter phantom, specifically designed to insert OSLDs, was used to assess radiation dose over a typical whole-body mouse imaging study. Eighteen healthy female BALB/c mice weighing 27.1 ± 0.8 g (1 SD) were euthanized for small animal measurements. OLSDs were placed externally or implanted internally in nine different locations by an experienced animal technician. Five commonly used micro-CT protocols were investigated.Results: CTDI measurements were between 78.0 ± 2.1 and 110.7 ± 3.0 mGy for the rat-like phantom and between 169.3 ± 4.6 and 203.6 ± 5.5 mGy for the mouse-like phantom. On average, the displayed CTDI at the operator console was underestimated by 1.19 for the rat-like phantom and 2.36 for the mouse

  10. Role of quantitative chemical shift magnetic resonance imaging and chemical shift subtraction technique in discriminating adenomatous from non adenomatous adrenal solid lesions

    Directory of Open Access Journals (Sweden)

    Ahmed H. Afifi

    2017-03-01

    Conclusion: The signal intensity index and adrenal to spleen ratio are the most reliable quantitative chemical shift MRI methods in differentiation of adrenal adenomas from other non-adenomatous adrenal solid lesions. Chemical shift subtraction MRI is a recent technique that gives highly confident discrimination between two categories of pathology without using of any reference organ.

  11. Chemical-Free Technique to Study the Ultrastructure of Primary Cilium.

    Science.gov (United States)

    Mohieldin, Ashraf M; AbouAlaiwi, Wissam A; Gao, Min; Nauli, Surya M

    2015-11-02

    A primary cilium is a hair-like structure with a width of approximately 200 nm. Over the past few decades, the main challenge in the study of the ultrastructure of cilia has been the high sensitivity of cilia to chemical fixation, which is required for many imaging techniques. In this report, we demonstrate a combined high-pressure freezing (HPF) and freeze-fracture transmission electron microscopy (FFTEM) technique to examine the ultrastructure of a cilium. Our objective is to develop an optimal high-resolution imaging approach that preserves cilia structures in their best natural form without alteration of cilia morphology by chemical fixation interference. Our results showed that a cilium has a swelling-like structure (termed bulb), which was previously considered a fixation artifact. The intramembrane particles observed via HPF/FFTEM indicated the presence of integral membrane proteins and soluble matrix proteins along the ciliary bulb, which is part of an integral structure within the ciliary membrane. We propose that HPF/FFTEM is an important and more suitable chemical-free method to study the ultrastructure of primary cilia.

  12. Study of chemical cleaning technique for removing sludge in secondary side of PWR SG

    International Nuclear Information System (INIS)

    Zhang Mengqin; Zhang Shufeng; Pan Qingchun; Yu Jinghua; Hou Shufeng

    1993-12-01

    The effect of components, concentration, pH, temperature, cleaning time and flowrate of chemical cleaning solvent made from EDTA mainly on Fe 3 O 4 solubility and corrosion rate of A3 carbon steel, S271 low alloy steel and 800 alloy are introduced. A small chemical cleaning test loop (30L) was built to study the cleaning technique. The effect of residue of chemical cleaning solvent on anti-corrosion performance of materials has been studied under the simulation condition of PWR (pressure water reactor) SG (steam generator) secondary side. The results show that the chemical solvent (pH = 7, 10% EDTA, 1% assistance solvent and 0.25% inhibitor A) can dissolve Fe 3 O 4 18 ∼23 g/L under the conditions of 93 +- 5 degree C, 8 hours and 112 r/min (1.8 ∼ 2.0 t/h). The corrosion rate of material is low. When the residue of EDTA is less than 0.01% there is no impact on the anti-corrosion performance of materials in PWR SG secondary side at normal operation condition (260 +- 5 degree C)

  13. Direct synthesis of nanocrystalline oxide powders by wet-chemical techniques

    Directory of Open Access Journals (Sweden)

    Vladimir V. Srdić

    2010-09-01

    Full Text Available In a recent period there is a great need for increasing the knowledge of tailoring the innovative procedures for the synthesis of electroceramic nanopowders and materials with improved quality for specific application. In order to produce electroceramics with desirable microstructure and properties, synthesis of stoichiometric, ultra-fine and agglomerate free powders with narrow size distributions is one of the most important steps. Within this scope, in the present paper we summarize our recent results on direct synthesis of some important perovskites and ferrites nanopowders by wet-chemical techniques.

  14. Chemical stability of fluorine-containing coatings of cold drying for radiation - protection technique articles

    International Nuclear Information System (INIS)

    Shigorina, I.I.; Zvyagintseva, N.V.; Egorov, B.N.

    1977-01-01

    The chemical stability of fluorolon coatings, which are not subjected to heat treatment or hot drying during application, has been studied. The test for layer life-time has been performed by submerging specimens in agressive medium. The time for one upper removable layer to fail under steady action of agressive liquid is found to be: > 12 months at 20 deg C, 6-9 months at 40 deg C; at 60 deg C the time of layer stability depends upon medium: 1 month for nitric, 2 months for acetic, 2-3 months for sulphuric and hydrochloric acid. The coatings are recommended for practical application in radiation-protective technique

  15. ZnO nanowall network grown by chemical vapor deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Amrita, E-mail: but.then.perhaps@gmail.com; Dhar, Subhabrata [Department of Physics, Indian Institute of Technology Bombay, Powai, Mumbai-400076 (India)

    2015-06-24

    Network of wedge shaped ZnO nanowalls are grown on c-sapphire by Chemical Vapor Deposition (CVD) technique. Structural studies using x-ray diffraction show much better crystallinity in the nanowall sample as compared to the continuous film. Moreover, the defect related broad green luminescence is found to be suppressed in the nanowall sample. The low temperature photoluminescence study also suggests the quantum confinement of carriers in nanowall sample. Electrical studies performed on the nanowalls show higher conductivity, which has been explained in terms of the reduction of scattering cross-section as a result of 1D quantum confinement of carriers on the tip of the nanowalls.

  16. New radiochemistry techniques monograph: open-quotes Ultrafast chemical separationsclose quotes

    International Nuclear Information System (INIS)

    Ypsilanti, M.I.; Meyer, R.A.; Rengan, K.

    1992-01-01

    Study of decay characteristics of short-lived nuclides has fascinated nuclear chemists ever since the discovery of radioactivity. In the last two decades nuclides with half-lives in the range of several seconds to several tens of seconds have been explored. In addition to manual procedures, several automatic batch (autobatch) as well as continuous separation procedures have been developed for the study of these nuclides. The first part of the radiochemical techniques monograph entitled open-quotes Ultrafast Chemical Separationsclose quotes reviews the techniques used in fast separations. A collection of known fast procedures, arranged according to the name of the element, is presented in the second part. A total of 316 procedures for 75 elements are included

  17. Physical and chemical properties of gels. Application to protein nucleation control in the gel acupuncture technique

    Science.gov (United States)

    Moreno, Abel; Juárez-Martínez, Gabriela; Hernández-Pérez, Tomás; Batina, Nikola; Mundo, Manuel; McPherson, Alexander

    1999-09-01

    In this work, we present a new approach using analytical and optical techniques in order to determine the physical and chemical properties of silica gel, as well as the measurement of the pore size in the network of the gel by scanning electron microscopy. The gel acupuncture technique developed by García-Ruiz et al. (Mater. Res. Bull 28 (1993) 541) García-Ruiz and Moreno (Acta Crystallogr. D 50 (1994) 484) was used throughout the history of crystal growth. Several experiments were done in order to evaluate the nucleation control of model proteins (thaumatin I from Thaumatococcus daniellii, lysozyme from hen egg white and catalase from bovine liver) by the porous network of the gel. Finally, it is shown how the number and the size of the crystals obtained inside X-ray capillaries is controlled by the size of the porous structure of the gel.

  18. Metallographic examination of TD-nickel base alloys. [thermal and chemical etching technique evaluation

    Science.gov (United States)

    Kane, R. D.; Petrovic, J. J.; Ebert, L. J.

    1975-01-01

    Techniques are evaluated for chemical, electrochemical, and thermal etching of thoria dispersed (TD) nickel alloys. An electrochemical etch is described which yielded good results only for large grain sizes of TD-nickel. Two types of thermal etches are assessed for TD-nickel: an oxidation etch and vacuum annealing of a polished specimen to produce an etch. It is shown that the first etch was somewhat dependent on sample orientation with respect to the processing direction, the second technique was not sensitive to specimen orientation or grain size, and neither method appear to alter the innate grain structure when the materials were fully annealed prior to etching. An electrochemical etch is described which was used to observe the microstructures in TD-NiCr, and a thermal-oxidation etch is shown to produce better detail of grain boundaries and to have excellent etching behavior over the entire range of grain sizes of the sample.

  19. Development of optically stimulated luminescence techniques using natural minerals and ceramics, and their application to retrospective dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Boetter-Jensen, L

    2000-09-01

    This thesis summarises research and development of optically stimulated luminescence (OSL) and its applications by the author at Risoe National Laboratory, up to 1999. These developments have been directed primarily at retrospective accident dosimetry and luminescence dating. Experimental investigations include the studies of OSL properties of the natural minerals quartz and feldspars and the artificial materials porcelain and aluminium oxide (Al{sub 2}O{sub 3}). Blue light emitting diodes and infrared laser diodes are shown to provide simple and practical alternatives to broad-band light and visible laser stimulation. The development of OSL apparatus designed for the rapid measurement of single grains of phosphors also opens up a new area of luminescence measurement, allowing the detailed examination of dose distributions within a multiple-grain sample. This is of particular importance to the studies of incompletely reset geological sediments, and to accident dosimetry measurements using unheated materials. Al{sub 2}O{sub 3}:C single crystals are tested as environmental OSL dosemeters for assessing both the natural background photon radiation dose rates in the field and the natural dose rates inside bricks collected for accident dose evaluation. Environmental doses of the order of few {mu}Gy are measured with high precision. UV photo-stimulated luminescence spectra obtained from porcelain samples are used to confirm that the main component responsible for the OSL signal from porcelain is Al{sub 2}O{sub 3}. OSL single-aliquot regenerative-dose (SAR) techniques are used with quartz extracted from Chernobyl bricks to determine the accrued dose after the accident. This has improved the measurement precision significantly, from about 5-6 % using traditional methods to now less than 2 %. Depth-dose profiles measured in Chernobyl bricks are compared with those obtained in the laboratory using different gamma sources and these comparisons show that the average energy of

  20. Development of optically stimulated luminescence techniques using natural minerals and ceramics, and their application to retrospective dosimetry

    International Nuclear Information System (INIS)

    Boetter-Jensen, L.

    2000-09-01

    This thesis summarises research and development of optically stimulated luminescence (OSL) and its applications by the author at Risoe National Laboratory, up to 1999. These developments have been directed primarily at retrospective accident dosimetry and luminescence dating. Experimental investigations include the studies of OSL properties of the natural minerals quartz and feldspars and the artificial materials porcelain and aluminium oxide (Al 2 O 3 ). Blue light emitting diodes and infrared laser diodes are shown to provide simple and practical alternatives to broad-band light and visible laser stimulation. The development of OSL apparatus designed for the rapid measurement of single grains of phosphors also opens up a new area of luminescence measurement, allowing the detailed examination of dose distributions within a multiple-grain sample. This is of particular importance to the studies of incompletely reset geological sediments, and to accident dosimetry measurements using unheated materials. Al 2 O 3 :C single crystals are tested as environmental OSL dosemeters for assessing both the natural background photon radiation dose rates in the field and the natural dose rates inside bricks collected for accident dose evaluation. Environmental doses of the order of few μGy are measured with high precision. UV photo-stimulated luminescence spectra obtained from porcelain samples are used to confirm that the main component responsible for the OSL signal from porcelain is Al 2 O 3 . OSL single-aliquot regenerative-dose (SAR) techniques are used with quartz extracted from Chernobyl bricks to determine the accrued dose after the accident. This has improved the measurement precision significantly, from about 5-6 % using traditional methods to now less than 2 %. Depth-dose profiles measured in Chernobyl bricks are compared with those obtained in the laboratory using different gamma sources and these comparisons show that the average energy of the accident radiation was

  1. Proteomic Analysis of Human Adipose Derived Stem Cells during Small Molecule Chemical Stimulated Pre-neuronal Differentiation.

    Science.gov (United States)

    Santos, Jerran; Milthorpe, Bruce K; Herbert, Benjamin R; Padula, Matthew P

    2017-11-30

    Adipose derived stem cells (ADSCs) are acquired from abdominal liposuction yielding a thousand fold more stem cells per millilitre than those from bone marrow. A large research void exists as to whether ADSCs are capable of transdermal differentiation toward neuronal phenotypes. Previous studies have investigated the use of chemical cocktails with varying inconclusive results. Human ADSCs were treated with a chemical stimulant, beta-mercaptoethanol, to direct them toward a neuronal-like lineage within 24 hours. Quantitative proteomics using iTRAQ was then performed to ascertain protein abundance differences between ADSCs, beta-mercaptoethanol treated ADSCs and a glioblastoma cell line. The soluble proteome of ADSCs differentiated for 12 hours and 24 hours was significantly different from basal ADSCs and control cells, expressing a number of remodeling, neuroprotective and neuroproliferative proteins. However toward the later time point presented stress and shock related proteins were observed to be up regulated with a large down regulation of structural proteins. Cytokine profiles support a large cellular remodeling shift as well indicating cellular distress. The earlier time point indicates an initiation of differentiation. At the latter time point there is a vast loss of cell population during treatment. At 24 hours drastically decreased cytokine profiles and overexpression of stress proteins reveal that exposure to beta-mercaptoethanol beyond 24 hours may not be suitable for clinical application as our results indicate that the cells are in trauma whilst producing neuronal-like morphologies. The shorter treatment time is promising, indicating a reducing agent has fast acting potential to initiate neuronal differentiation of ADSCs.

  2. Analysis techniques of lattice fringe images for quantified evaluation of pyrocarbon by chemical vapor infiltration.

    Science.gov (United States)

    Li, Miaoling; Zhao, Hongxia; Qi, Lehua; Li, Hejun

    2014-10-01

    Some image analysis techniques are developed for simplifying lattice fringe images of deposited pyrocarbon in carbon/carbon composites by chemical vapor infiltration. They are mainly the object counting method for detecting the optimum threshold, the self-adaptive morphological filtering, the node-separation technique for breaking the aggregate fringes, and some post processing algorithms for reconstructing the fringes. The simplified fringes are the foundation for defining and extracting quantitative nanostructure parameters of pyrocarbon. The frequency filter window of a Fourier transform is defined as the circular band that retains only those fringes with interlayer distance between 0.3 and 0.45 nm. Some judge criteria are set to define topological relation between fringes. For example, the aspect ratio and area of fringes are employed to detect aggregate fringes. Fringe coaxality and distance between endpoints are used to judge the disconnected fringes. The optimum values are determined by using the iterative correction techniques. The best cut-off value for the short fringes is chosen only when there is a reasonable match between the mean fringe length and the value measured by X-ray diffraction. The adopted techniques have been verified to be feasible and to have the potential to convert the complex lattice fringe image to a set of distinct fringe structures.

  3. Bioorthogonal chemical imaging of metabolic changes during epithelial-mesenchymal transition of cancer cells by stimulated Raman scattering microscopy

    Science.gov (United States)

    Zhang, Luyuan; Min, Wei

    2017-10-01

    Study of metabolic changes during epithelial-mesenchymal transition (EMT) of cancer cells is important for basic understanding and therapeutic management of cancer progression. We here used metabolic labeling and stimulated Raman scattering (SRS) microscopy, a strategy of bioorthogonal chemical imaging, to directly visualize changes in anabolic metabolism during cancer EMT at a single-cell level. MCF-7 breast cancer cell is employed as a model system. Four types of metabolites (amino acids, glucose, fatty acids, and choline) are labeled with either deuterium or alkyne (C≡C) tag. Their intracellular incorporations into MCF-7 cells before or after EMT are visualized by SRS imaging targeted at the signature vibration frequency of C-D or C≡C bonds. Overall, after EMT, anabolism of amino acids, glucose, and choline is less active, reflecting slower protein and membrane synthesis in mesenchymal cells. Interestingly, we also observed less incorporation of glucose and palmitate acids into membrane lipids, but more of them into lipid droplets in mesenchymal cells. This result indicates that, although mesenchymal cells synthesize fewer membrane lipids, they are actively storing energy into lipid droplets, either through de novo lipogenesis from glucose or direct scavenging of exogenous free fatty acids. Hence, metabolic labeling coupled with SRS can be a straightforward method in imaging cancer metabolism.

  4. Bottom-Up, Wet Chemical Technique for the Continuous Synthesis of Inorganic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Annika Betke

    2014-01-01

    Full Text Available Continuous wet chemical approaches for the production of inorganic nanoparticles are important for large scale production of nanoparticles. Here we describe a bottom-up, wet chemical method applying a microjet reactor. This technique allows the separation between nucleation and growth in a continuous reactor environment. Zinc oxide (ZnO, magnetite (Fe3O4, as well as brushite (CaHPO4·2H2O, particles with a small particle size distribution can be obtained continuously by using the rapid mixing of two precursor solutions and the fast removal of the nuclei from the reaction environment. The final particles were characterized by FT-IR, TGA, DLS, XRD and SEM techniques. Systematic studies on the influence of the different process parameters, such as flow rate and process temperature, show that the particle size can be influenced. Zinc oxide was obtained with particle sizes between 44 nm and 102 nm. The obtained magnetite particles have particle sizes in the range of 46 nm to 132 nm. Brushite behaves differently; the obtained particles were shaped like small plates with edge lengths between 100 nm and 500 nm.

  5. Review of cleaning techniques and their effects on the chemical composition of foliar samples

    Energy Technology Data Exchange (ETDEWEB)

    Rossini Oliva, S.; Raitio, H.

    2003-07-01

    Chemical foliar analysis is a tool widely used to study tree nutrition and to monitor the impact and extent of air pollutants. This paper reviews a number of cleaning methods, and the effects of cleaning on foliar chemistry. Cleaning may include mechanical techniques such as the use of dry or moistened tissues, shaking, blowing, and brushing, or use various washing techniques with water or other solvents. Owing to the diversity of plant species, tissue differences, etc., there is no standard procedure for all kinds of samples. Analysis of uncleaned leaves is considered a good method for assessing the degree of air contamination because it provides an estimate of the element content of the deposits on leaf surfaces or when the analysis is aimed at the investigation of transfer of elements along the food chain. Sample cleaning is recommended in order (1) to investigate the transfer rate of chemical elements from soil to plants, (2) to qualify the washoff of dry deposition from foliage and (3) to separate superficially absorbed and biomass-incorporated elements. Since there is not a standard cleaning procedure for all kinds of samples and aims, it is advised to conduct a pilot study in order to be able to establish a cleaning procedure to provide reliable foliar data. (orig.)

  6. Nanostructured PLD-grown gadolinia doped ceria: Chemical and structural characterization by transmission electron microscopy techniques

    DEFF Research Database (Denmark)

    Rodrigo, Katarzyna Agnieszka; Wang, Hsiang-Jen; Heiroth, Sebastian

    2011-01-01

    The morphology as well as the spatially resolved elemental and chemical characterization of 10 mol% gadolinia doped ceria (CGO10) structures prepared by pulsed laser deposition (PLD) technique are investigated by scanning transmission electron microscopy accompanied with electron energy loss spec......, indicate apparent variation of the ceria valence state across and along the film. No element segregation to the grain boundaries is detected. These results are discussed in the context of solid oxide fuel cell applications.......The morphology as well as the spatially resolved elemental and chemical characterization of 10 mol% gadolinia doped ceria (CGO10) structures prepared by pulsed laser deposition (PLD) technique are investigated by scanning transmission electron microscopy accompanied with electron energy loss...... spectroscopy and energy dispersive X-ray spectroscopy. A dense, columnar and structurally inhomogeneous CGO10 film, i.e. exhibiting grain size refinement across the film thickness, is obtained in the deposition process. The cerium M4,5 edges, used to monitor the local electronic structure of the grains...

  7. A cell-microelectronic sensing technique for profiling cytotoxicity of chemicals

    International Nuclear Information System (INIS)

    Boyd, Jessica M.; Huang, Li; Xie Li; Moe, Birget; Gabos, Stephan; Li Xingfang

    2008-01-01

    A cell-microelectronic sensing technique is developed for profiling chemical cytotoxicity and is used to study different cytotoxic effects of the same class chemicals using nitrosamines as examples. This technique uses three human cell lines (T24 bladder, HepG2 liver, and A549 lung carcinoma cells) and Chinese hamster ovary (CHO-K1) cells in parallel as the living components of the sensors of a real-time cell electronic sensing (RT-CES) method for dynamic monitoring of chemical toxicity. The RT-CES technique measures changes in the impedance of individual microelectronic wells that is correlated linearly with changes in cell numbers during t log phase of cell growth, thus allowing determination of cytotoxicity. Four nitrosamines, N-nitrosodimethylamine (NDMA), N-nitrosodiphenylamine (NDPhA), N-nitrosopiperidine (NPip), and N-nitrosopyrrolidine (NPyr), were examined and unique cytotoxicity profiles were detected for each nitrosamine. In vitro cytotoxicity values (IC 50 ) for NDPhA (ranging from 0.6 to 1.9 mM) were significantly lower than the IC 50 values for the well-known carcinogen NDMA (15-95 mM) in all four cell lines. T24 cells were the most sensitive to nitrosamine exposure among the four cell lines tested (T24 > CHO > A549 > HepG2), suggesting that T24 may serve as a new sensitive model for cytotoxicity screening. Cell staining results confirmed that administration of the IC 50 concentration from the RT-CES experiments inhibited cell growth by 50% compared to the controls, indicating that the RT-CES method provides reliable measures of IC 50 . Staining and cell-cycle analysis confirmed that NDPhA caused cell-cycle arrest at the G0/G1 phase, whereas NDMA did not disrupt the cell cycle but induced cell death, thus explaining the different cytotoxicity profiles detected by the RT-CES method. The parallel cytotoxicity profiling of nitrosamines on the four cell lines by the RT-CES method led to the discovery of the unique cytotoxicity of NDPhA causing cell

  8. A cell-microelectronic sensing technique for profiling cytotoxicity of chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, Jessica M [Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, 10-102 Clinical Sciences Building, Edmonton, Alberta, T6G 2G3 (Canada); Huang, Li [Environmental Health Sciences, Department of Public Health Sciences, School of Public Health, University of Alberta, 10-102 Clinical Sciences Building, Edmonton, Alberta, T6G 2G3 (Canada); Li, Xie; Moe, Birget [Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, 10-102 Clinical Sciences Building, Edmonton, Alberta, T6G 2G3 (Canada); Gabos, Stephan [Public Health Surveillance and Environmental Health, Alberta Health and Wellness, 10025 Jasper Avenue, Box 1360, Edmonton, Alberta, T5J 2N3 (Canada); Xingfang, Li [Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, 10-102 Clinical Sciences Building, Edmonton, Alberta, T6G 2G3 (Canada); Environmental Health Sciences, Department of Public Health Sciences, School of Public Health, University of Alberta, 10-102 Clinical Sciences Building, Edmonton, Alberta, T6G 2G3 (Canada)], E-mail: xingfang.li@ualberta.ca

    2008-05-12

    A cell-microelectronic sensing technique is developed for profiling chemical cytotoxicity and is used to study different cytotoxic effects of the same class chemicals using nitrosamines as examples. This technique uses three human cell lines (T24 bladder, HepG2 liver, and A549 lung carcinoma cells) and Chinese hamster ovary (CHO-K1) cells in parallel as the living components of the sensors of a real-time cell electronic sensing (RT-CES) method for dynamic monitoring of chemical toxicity. The RT-CES technique measures changes in the impedance of individual microelectronic wells that is correlated linearly with changes in cell numbers during t log phase of cell growth, thus allowing determination of cytotoxicity. Four nitrosamines, N-nitrosodimethylamine (NDMA), N-nitrosodiphenylamine (NDPhA), N-nitrosopiperidine (NPip), and N-nitrosopyrrolidine (NPyr), were examined and unique cytotoxicity profiles were detected for each nitrosamine. In vitro cytotoxicity values (IC{sub 50}) for NDPhA (ranging from 0.6 to 1.9 mM) were significantly lower than the IC{sub 50} values for the well-known carcinogen NDMA (15-95 mM) in all four cell lines. T24 cells were the most sensitive to nitrosamine exposure among the four cell lines tested (T24 > CHO > A549 > HepG2), suggesting that T24 may serve as a new sensitive model for cytotoxicity screening. Cell staining results confirmed that administration of the IC{sub 50} concentration from the RT-CES experiments inhibited cell growth by 50% compared to the controls, indicating that the RT-CES method provides reliable measures of IC{sub 50}. Staining and cell-cycle analysis confirmed that NDPhA caused cell-cycle arrest at the G0/G1 phase, whereas NDMA did not disrupt the cell cycle but induced cell death, thus explaining the different cytotoxicity profiles detected by the RT-CES method. The parallel cytotoxicity profiling of nitrosamines on the four cell lines by the RT-CES method led to the discovery of the unique cytotoxicity of NDPh

  9. Identification of cow milk in goat milk by nonlinear chemical fingerprint technique.

    Science.gov (United States)

    Ma, Yong-Jie; Dong, Wen-Bin; Fan, Cheng; Wang, Er-Dan

    2017-10-01

    The objective of this paper was to develop a nonlinear chemical fingerprint technique for identifying and detecting adulteration of goat milk with cow milk. In this study, by taking the Belousov-Zhabotinsky oscillatory chemical reaction using acetone and substrates in goat milk or cow milk as main dissipative substances, when the same dosage of goat milk and cow milk was introduced to the "H +  + Mn 2+  + BrO 3 -  + acetone" oscillating system respectively, nonlinear chemical fingerprints were obtained for goat milk and cow milk from the same origin. The results showed that inductive time value and the content of cow milk in goat milk had a linear relationship in the range of 0-100% and the corresponding regression coefficient was 0.9991. A detection limit of 0.0107 g/g was obtained, and the content of cow milk in mixed milk was calculated. The proposed method in this study was simple, economical and effective. In addition, the method did not need the pretreatment and separation of samples for identifying and evaluating cow milk adulteration in goat milk. Copyright © 2017. Published by Elsevier B.V.

  10. Determination of alpha-naphthol by an oscillating chemical reaction using the analyte pulse perturbation technique

    International Nuclear Information System (INIS)

    Yang Wu; Sun Kanjun; Lv Weilian; Bo Lili; He Xiaoyan; Suo Nan; Gao Jinzhang

    2005-01-01

    An analytical method for the determination of alpha-naphthol (α-NP) is proposed by the sequential perturbation caused by different amounts of alpha-naphthol on the oscillating chemical system involving the Cu(II)-catalyzed oscillating reaction between hydrogen peroxide and sodium thiocyanate in an alkaline medium with the aid of continuous-flow stirred tank reactor (CSTR). The method relies on the linear relationship between the changes in the oscillation amplitude of the chemical system and the concentration of alpha-naphthol. The use of the analyte pulse perturbation technique permits sequential determinations in the same oscillating system owing to the expeditiousness with which the steady state is regained after each perturbation. The calibration curve obeys a linear equation very well when the concentration of alpha-naphthol is over the range 0.034-530 umol/L (r = 0.9991). Influences of temperature, injection points, flow rate and reaction variables on the oscillating system are investigated in detail and the possible mechanism of action of alpha-naphthol to the chemical oscillating system is also discussed. The method has been successfully used for the determination of α-naphthol in carbaryl hydrolysates

  11. Chemical reactions of fission products with ethylene using the gas jet technique

    International Nuclear Information System (INIS)

    Contis, E.T.; Rengan, Krish; Griffin, Henry C.

    1994-01-01

    An understanding of the nature of the chemical reactions taking place between fission products and their carrier gases, and the designing of a fast separation procedure were the purposes of this investigation. Chemical reactions of short-lived (less than one minute half-life) fission products with carrier gases lead to various chemical species which can be separated in the gas phase. The Gas Jet Facility at the Ford Nuclear Reactor was used to study the yields of volatile selenium and bromine fission products of 235 U using a semi-automatic batch solvent extraction technique. Heptane and water were used as organic and inorganic solvents. A carrier gas mixture of ethylene to pre-purified nitrogen (1 : 3) was used to sweep the fission products from the target to the chemistry area for analysis. The results indicated that the volatile selenium products generated by the interaction of selenium fission fragments with ethylene were predominantly organic in nature (84%), possibly organoselenides. The selenium values were used to resolve the fractions of the bromine nuclides, which come from two major sources, viz., directly from fission and from the beta-decay of selenium. The data showed that the fractions of independent bromine fission products in the organic phase were much lower compared to selenium; the bromine values range from 10 to 22% and varied with mass number. Results indicated that the bromine products were inorganic in nature, as possibly hydrogen chloride. ((orig.))

  12. Application and further development of diffusion based 2D chemical imaging techniques in the rhizosphere

    Science.gov (United States)

    Hoefer, Christoph; Santner, Jakob; Borisov, Sergey; Kreuzeder, Andreas; Wenzel, Walter; Puschenreiter, Markus

    2015-04-01

    Two dimensional chemical imaging of root processes refers to novel in situ methods to investigate and map solutes at a high spatial resolution (sub-mm). The visualization of these solutes reveals new insights in soil biogeochemistry and root processes. We derive chemical images by using data from DGT-LA-ICP-MS (Diffusive Gradients in Thin Films and Laser Ablation Inductively Coupled Plasma Mass Spectrometry) and POS (Planar Optode Sensors). Both technologies have shown promising results when applied in aqueous environment but need to be refined and improved for imaging at the soil-plant interface. Co-localized mapping using combined DGT and POS technologies and the development of new gel combinations are in our focus. DGTs are smart and thin (hydrogels; containing a binding resin for the targeted analytes (e.g. trace metals, phosphate, sulphide or radionuclides). The measurement principle is passive and diffusion based. The present analytes are diffusing into the gel and are bound by the resin. Thereby, the resin acts as zero sink. After application, DGTs are retrieved, dried, and analysed using LA-ICP-MS. The data is then normalized by an internal standard (e.g. 13C), calibrated using in-house standards and chemical images of the target area are plotted using imaging software. POS are, similar to DGT, thin sensor foils containing a fluorophore coating depending on the target analyte. The measurement principle is based on excitation of the flourophore by a specific wavelength and emission of the fluorophore depending on the presence of the analyte. The emitted signal is captured using optical filters and a DSLR camera. While DGT analysis is destructive, POS measurements can be performed continuously during the application. Both semi-quantitative techniques allow an in situ application to visualize chemical processes directly at the soil-plant interface. Here, we present a summary of results from rhizotron experiments with different plants in metal contaminated and

  13. Rehabilitation of Motor Function after Stroke: A Multiple Systematic Review Focused on Techniques to Stimulate Upper Extremity Recovery

    Science.gov (United States)

    Hatem, Samar M.; Saussez, Geoffroy; della Faille, Margaux; Prist, Vincent; Zhang, Xue; Dispa, Delphine; Bleyenheuft, Yannick

    2016-01-01

    Stroke is one of the leading causes for disability worldwide. Motor function deficits due to stroke affect the patients' mobility, their limitation in daily life activities, their participation in society and their odds of returning to professional activities. All of these factors contribute to a low overall quality of life. Rehabilitation training is the most effective way to reduce motor impairments in stroke patients. This multiple systematic review focuses both on standard treatment methods and on innovating rehabilitation techniques used to promote upper extremity motor function in stroke patients. A total number of 5712 publications on stroke rehabilitation was systematically reviewed for relevance and quality with regards to upper extremity motor outcome. This procedure yielded 270 publications corresponding to the inclusion criteria of the systematic review. Recent technology-based interventions in stroke rehabilitation including non-invasive brain stimulation, robot-assisted training, and virtual reality immersion are addressed. Finally, a decisional tree based on evidence from the literature and characteristics of stroke patients is proposed. At present, the stroke rehabilitation field faces the challenge to tailor evidence-based treatment strategies to the needs of the individual stroke patient. Interventions can be combined in order to achieve the maximal motor function recovery for each patient. Though the efficacy of some interventions may be under debate, motor skill learning, and some new technological approaches give promising outcome prognosis in stroke motor rehabilitation. PMID:27679565

  14. Rehabilitation of motor function after stroke: a multiple systematic review focused on techniques to stimulate upper extremity recovery

    Directory of Open Access Journals (Sweden)

    Samar M Hatem

    2016-09-01

    Full Text Available Stroke is one of the leading causes for disability worldwide. Motor function deficits due to stroke affect the patients’ mobility, their limitation in daily life activities, their participation in society and their odds of returning to professional activities. All of these factors contribute to a low overall quality of life. Rehabilitation training is the most effective way to reduce motor impairments in stroke patients. This multiple systematic review focuses both on standard treatment methods and on innovating rehabilitation techniques used to promote upper extremity motor function in stroke patients. A total number of 5712 publications on stroke rehabilitation was systematically reviewed for relevance and quality with regards to upper extremity motor outcome. This procedure yielded 270 publications corresponding to the inclusion criteria of the systematic review. Recent technology-based interventions in stroke rehabilitation including non-invasive brain stimulation, robot-assisted training and virtual reality immersion are addressed. Finally, a decisional tree based on evidence from the literature and characteristics of stroke patients is proposed.At present, the stroke rehabilitation field faces the challenge to tailor evidence-based treatment strategies to the needs of the individual stroke patient. Interventions can be combined in order to achieve the maximal motor function recovery for each patient. Though the efficacy of some interventions may be under debate, motor skill learning and some new technological approaches give promising outcome prognosis in stroke motor rehabilitation.

  15. Treating Stress-Related Pain with the Flotation Restricted Environmental Stimulation Technique: Are There Differences between Women and Men?

    Directory of Open Access Journals (Sweden)

    Sven Å Bood

    2009-01-01

    Full Text Available The aim of the present study was to explore, for the first time, sex differences among patients diagnosed with stress-related pain before and after flotation restricted environmental stimulation technique (REST treatment, delivered 12 times during seven weeks. The present study included 88 patients (69 women, 19 men from three different studies (post hoc analysis. They had been diagnosed by a physician as having chronic stress-related muscle tension pain. The analyses indicated that the flotation-REST treatment had beneficial effects on stress, anxiety, depression, sleep quality and pain and that there were few sex differences. Women were more depressed than men before treatment, but after treatment there was no difference between sexes. However, there was a sex difference in the ability to endure experimentally induced pain, suggesting that men exhibited greater endurance both before and after the flotation-REST treatment. The results also showed, for the first time, that both sexes improved their ability to endure experimentally induced pain (higher scores for upper pain threshold following the successful flotation-REST pain treatment.

  16. Dry-plasma-free chemical etch technique for variability reduction in multi-patterning (Conference Presentation)

    Science.gov (United States)

    Kal, Subhadeep; Mohanty, Nihar; Farrell, Richard A.; Franke, Elliott; Raley, Angelique; Thibaut, Sophie; Pereira, Cheryl; Pillai, Karthik; Ko, Akiteru; Mosden, Aelan; Biolsi, Peter

    2017-04-01

    Scaling beyond the 7nm technology node demands significant control over the variability down to a few angstroms, in order to achieve reasonable yield. For example, to meet the current scaling targets it is highly desirable to achieve sub 30nm pitch line/space features at back-end of the line (BEOL) or front end of line (FEOL); uniform and precise contact/hole patterning at middle of line (MOL). One of the quintessential requirements for such precise and possibly self-aligned patterning strategies is superior etch selectivity between the target films while other masks/films are exposed. The need to achieve high etch selectivity becomes more evident for unit process development at MOL and BEOL, as a result of low density films choices (compared to FEOL film choices) due to lower temperature budget. Low etch selectivity with conventional plasma and wet chemical etch techniques, causes significant gouging (un-intended etching of etch stop layer, as shown in Fig 1), high line edge roughness (LER)/line width roughness (LWR), non-uniformity, etc. In certain circumstances this may lead to added downstream process stochastics. Furthermore, conventional plasma etches may also have the added disadvantage of plasma VUV damage and corner rounding (Fig. 1). Finally, the above mentioned factors can potentially compromise edge placement error (EPE) and/or yield. Therefore a process flow enabled with extremely high selective etches inherent to film properties and/or etch chemistries is a significant advantage. To improve this etch selectivity for certain etch steps during a process flow, we have to implement alternate highly selective, plasma free techniques in conjunction with conventional plasma etches (Fig 2.). In this article, we will present our plasma free, chemical gas phase etch technique using chemistries that have high selectivity towards a spectrum of films owing to the reaction mechanism ( as shown Fig 1). Gas phase etches also help eliminate plasma damage to the

  17. Studying Chemical Reactions, One Bond at a Time, with Single Molecule AFM Techniques

    Science.gov (United States)

    Fernandez, Julio M.

    2008-03-01

    atomic force microscopy (AFM) techniques, as shown here, can probe dynamic rearrangements within an enzyme's active site which cannot be resolved with any other current structural biological technique. Furthermore, our work at the single bond level directly demonstrates that thiol/disulfide exchange in proteins is a force-dependent chemical reaction. Our findings suggest that mechanical force plays a role in disulfide reduction in vivo, a property which has never been explored by traditional biochemistry. 1.-Wiita, A.P., Ainavarapu, S.R.K., Huang, H.H. and Julio M. Fernandez (2006) Force-dependent chemical kinetics of disulfide bond reduction observed with single molecule techniques. Proc Natl Acad Sci U S A. 103(19):7222-7 2.-Wiita, A.P., Perez-Jimenez, R., Walther, K.A., Gräter, F. Berne, B.J., Holmgren, A., Sanchez-Ruiz, J.M., and Fernandez, J.M. (2007) Probing the chemistry of thioredoxin catalysis with force. Nature, 450:124-7.

  18. Separation and sampling technique of light element isotopes by chemical exchange process

    International Nuclear Information System (INIS)

    Kato, Shunsaku; Oi, Kenta; Takagi, Norio; Hirotsu, Takafumi; Kano, Hirofumi; Sonoda, Akinari; Makita, Yoji

    2000-01-01

    Lithium and boron isotope separation technique were studied. Granulation of lithium isotope separation agent was carried out by cure covering in solution. Separation of lithium isotope was stepped up by ammonium carbonate used as elusion agent. Styrene and ester resin derived three kinds of agents such as 2-amino-1, 3-propanediol (1, 3-PD), 2-amino-2-methyl-1, 3-propanediol (Me-1,3-PD) and tris(2-hydroxyethyl)amine (Tris) were used as absorbent.The ester resin with Tris showed larger amount of adsorption (1.4 mmol/g) than other resins. However, all resins with agent indicated more large adsorption volume of boron than the objective value (0.5 mmol/g). Large isotope shift was shown by the unsymmetrical vibration mode of lithium ion on the basis of quantum chemical calculation of isotope effect on dehydration of hydrated lithium ion. (S.Y.)

  19. Advancement in solar evaporation techniques for volume reduction of chemical effluents

    Energy Technology Data Exchange (ETDEWEB)

    Parakasamurthy, K S [Nuclear Fuel Complex, Hyderabad (India); Pande, D P [Process Engineering and Systems Development Division, Bhabha Atomic Research Centre, Mumbai (India)

    1994-06-01

    A typical example of advancement of a unit operation for the given requirement is described. The solar evaporation ponds (SEP) have technical and economic advantages compared to other evaporation methods for concentrating chemical effluents. The operation of SEP is strongly dependent on the environmental and site conditions. Tropical conditions with high solar incidence, good wind speed along with hot and dry weather provide suitable climate for efficient operation of solar evaporation ponds. The particular site selected for the ponds at Nuclear Fuel Complex (NFC) has a rocky terrain with murrum over sheet with very low water table and small velocity of groundwater. During the past twenty five years extensive theoretical and experimental investigations have been carried out for advancement of solar evaporation technique. (author). 7 refs.

  20. Advancement in solar evaporation techniques for volume reduction of chemical effluents

    International Nuclear Information System (INIS)

    Parakasamurthy, K.S.; Pande, D.P.

    1994-01-01

    A typical example of advancement of a unit operation for the given requirement is described. The solar evaporation ponds (SEP) have technical and economic advantages compared to other evaporation methods for concentrating chemical effluents. The operation of SEP is strongly dependent on the environmental and site conditions. Tropical conditions with high solar incidence, good wind speed along with hot and dry weather provide suitable climate for efficient operation of solar evaporation ponds. The particular site selected for the ponds at Nuclear Fuel Complex (NFC) has a rocky terrain with murrum over sheet with very low water table and small velocity of groundwater. During the past twenty five years extensive theoretical and experimental investigations have been carried out for advancement of solar evaporation technique. (author)

  1. Diameter Tuning of β-Ga2O3 Nanowires Using Chemical Vapor Deposition Technique.

    Science.gov (United States)

    Kumar, Mukesh; Kumar, Vikram; Singh, R

    2017-12-01

    Diameter tuning of [Formula: see text]-Ga 2 O 3 nanowires using chemical vapor deposition technique have been investigated under various experimental conditions. Diameter of root grown [Formula: see text]-Ga 2 O 3 nanowires having monoclinic crystal structure is tuned by varying separation distance between metal source and substrate. Effect of gas flow rate and mixer ratio on the morphology and diameter of nanowires has been studied. Nanowire diameter depends on growth temperature, and it is independent of catalyst nanoparticle size at higher growth temperature (850-900 °C) as compared to lower growth temperature (800 °C). These nanowires show changes in structural strain value with change in diameter. Band-gap of nanowires increases with decrease in the diameter.

  2. Use of chemical and biological adjuvants to achieve the optimum application of radiological techniques

    International Nuclear Information System (INIS)

    Azab, K.S.

    2010-01-01

    Nowadays, the optimization and attainment of maximum guarantee are representing the real challenge for the nuclear technology exercise. The Adjuvant techniques might be considered one of the available tactics for the developing, reducing risk and facilitating secure clearing of nuclear waste in the field of radiation technology applications. The history describes the belief that an adjuvant is required for immunity because the immune system evolved to respond to dangerous situations such as infections, and the presence of an adjuvant is the mechanism used to identify these situations. In immunology, an adjuvant is an agent that may stimulate the immune system and increase the response to a vaccine, without having any specific antigenic effect. Adjuvants are coming increasingly into focus for vaccine developers since many novel split and subunit vaccines are insufficiently immunogenic on their own. Among the used today are alum (aluminum hydroxide) and Glycosyl ceramides. It is worth mentioning that manufacturers already had produced thousands of different adjuvants, for both industrial and agricultural purposes. Today, the agricultural and horticultural industries are being overwhelmed by adjuvant choices. Complete Freunds adjuvant is the adjuvant used in animal research studies of basic and applied immunology. (author)

  3. Evaluation of electrode surface modification techniques for the development of chemical sensors

    International Nuclear Information System (INIS)

    Galiatsatos, C.

    1988-01-01

    This thesis covers several aspects of electrode surface modification techniques. The successful application of gamma-radiation to create polymer-coated electrodes, where the polymers can be ion exchangers and consequently of great analytical interest by themselves (such as the polymer poly(diallyl) dimethyl ammonium chloride) or where some other neutral polymers can function as convenient matrices for the introduction of biomolecules and/or other electrochemically interesting species is reported. This is demonstrated by using the neutral polymer poly(vinyl alcohol) (PVAL) as a matrix for immobilization of the enzyme glucose oxidase and the mediator methyl viologen. The effect of γ-radiation on PVAL is discussed, as well as swelling properties of the irradiated polymers and specific characteristics of the created chemical sensors. Results of an experiment where the various kinds of interactions between the ion-exchange polymer Nafion and some positively charged species are explored are reported, and a model system for competition (methyl viologen vs. ruthenium hexaamine) which increases significantly our understanding of the interaction is mentioned. The effect of γ-radiation on Nafion and its ion-exchange compabilities is discussed also. A system of conduction polymers primarily polypyrrole, used as a detector of electroinactive anions due to their doping-undergoing in the film is discussed. Preliminary results on a new method that involves chemical cross-linking of a triisocyane molecule with -OH containing polymers in the presence of enzymes are reported

  4. Early detection and identification of anomalies in chemical regime based on computational intelligence techniques

    International Nuclear Information System (INIS)

    Figedy, Stefan; Smiesko, Ivan

    2012-01-01

    This article provides brief information about the fundamental features of a newly-developed diagnostic system for early detection and identification of anomalies being generated in water chemistry regime of the primary and secondary circuit of the VVER-440 reactor. This system, which is called SACHER (System of Analysis of CHEmical Regime), was installed within the major modernization project at the NPP-V2 Bohunice in the Slovak Republic. The SACHER system has been fully developed on MATLAB environment. It is based on computational intelligence techniques and inserts various elements of intelligent data processing modules for clustering, diagnosing, future prediction, signal validation, etc, into the overall chemical information system. The application of SACHER would essentially assist chemists to identify the current situation regarding anomalies being generated in the primary and secondary circuit water chemistry. This system is to be used for diagnostics and data handling, however it is not intended to fully replace the presence of experienced chemists to decide upon corrective actions. (author)

  5. Use of Modern Chemical Protein Synthesis and Advanced Fluorescent Assay Techniques to Experimentally Validate the Functional Annotation of Microbial Genomes

    Energy Technology Data Exchange (ETDEWEB)

    Kent, Stephen [University of Chicago

    2012-07-20

    The objective of this research program was to prototype methods for the chemical synthesis of predicted protein molecules in annotated microbial genomes. High throughput chemical methods were to be used to make large numbers of predicted proteins and protein domains, based on microbial genome sequences. Microscale chemical synthesis methods for the parallel preparation of peptide-thioester building blocks were developed; these peptide segments are used for the parallel chemical synthesis of proteins and protein domains. Ultimately, it is envisaged that these synthetic molecules would be ‘printed’ in spatially addressable arrays. The unique ability of total synthesis to precision label protein molecules with dyes and with chemical or biochemical ‘tags’ can be used to facilitate novel assay technologies adapted from state-of-the art single molecule fluorescence detection techniques. In the future, in conjunction with modern laboratory automation this integrated set of techniques will enable high throughput experimental validation of the functional annotation of microbial genomes.

  6. Construction of an experimental simplified model for determining of flow parameters in chemical reactors, using nuclear techniques

    International Nuclear Information System (INIS)

    Araujo Paiva, J.A. de.

    1981-03-01

    The development of a simplified experimental model for investigation of nuclear techniques to determine the solid phase parameters in gas-solid flows is presented. A method for the measurement of the solid phase residence time inside a chemical reactor of the type utilised in the cracking process of catalytic fluids is described. An appropriate radioactive labelling technique of the solid phase and the construction of an eletronic timing circuit were the principal stages in the definition of measurement technique. (Author) [pt

  7. Use of spectroscopic techniques for the chemical analysis of biomorphic silicon carbide ceramics

    International Nuclear Information System (INIS)

    Pavon, J.M. Cano; Alonso, E. Vereda; Cordero, M.T. Siles; Torres, A. Garcia de; Lopez-Cepero, J.M.

    2005-01-01

    Biomorphic silicon carbide ceramics are a new class of materials prepared by several complex processing steps including pre-processing (shaping, drying, high-temperature pyrolysis in an inert atmosphere) and reaction with liquid silicon to obtain silicon-carbide. The results of industrial process of synthesis (measured by the SiC content) must be evaluated by means of fast analytical methods. In the present work, diverse samples of biomorphic ceramics derived from wood are studied for to evaluate the capability of the different analytical techniques (XPS, LIBS, FT-IR and also atomic spectroscopy applied to previously dissolved samples) for the analysis of these materials. XPS and LIBS gives information about the major components, whereas XPS and FT-IR can be used to evaluate the content of SiC. On the other hand, .the use of atomic techniques (as ICP-MS and ETA-AAS) is more adequate for the analysis of metal ions, specially at trace level. The properties of ceramics depend decisively of the content of chemical elements. Major components found were C, Si, Al, S, B and Na in all cases. Previous dissolution of the samples was optimised by acid attack in an oven under microwave irradiation

  8. Chronic changes in pituitary adenylate cyclase-activating polypeptide and related receptors in response to repeated chemical dural stimulation in rats.

    Science.gov (United States)

    Han, Xun; Ran, Ye; Su, Min; Liu, Yinglu; Tang, Wenjing; Dong, Zhao; Yu, Shengyuan

    2017-01-01

    Background Preclinical experimental studies revealed an acute alteration of pituitary adenylate cyclase-activating polypeptide in response to a single activation of the trigeminovascular system, which suggests a potential role of pituitary adenylate cyclase-activating polypeptide in the pathogenesis of migraine. However, changes in pituitary adenylate cyclase-activating polypeptide after repeated migraine-like attacks in chronic migraine are not clear. Therefore, the present study investigated chronic changes in pituitary adenylate cyclase-activating polypeptide and related receptors in response to repeated chemical dural stimulations in the rat. Methods A rat model of chronic migraine was established by repeated chemical dural stimulations using an inflammatory soup for a different numbers of days. The pituitary adenylate cyclase-activating polypeptide levels were quantified in plasma, the trigeminal ganglia, and the trigeminal nucleus caudalis using radioimmunoassay and Western blotting in trigeminal ganglia and trigeminal nucleus caudalis tissues. Western blot analysis and real-time polymerase chain reaction were used to measure the protein and mRNA expression of pituitary adenylate cyclase-activating polypeptide-related receptors (PAC1, VPAC1, and VPAC2) in the trigeminal ganglia and trigeminal nucleus caudalis to identify changes associated with repetitive applications of chemical dural stimulations. Results All rats exhibited significantly decreased periorbital nociceptive thresholds to repeated inflammatory soup stimulations. Radioimmunoassay and Western blot analysis demonstrated significantly decreased pituitary adenylate cyclase-activating polypeptide levels in plasma and trigeminal ganglia after repetitive chronic inflammatory soup stimulation. Protein and mRNA analyses of pituitary adenylate cyclase-activating polypeptide-related receptors demonstrated significantly increased PAC1 receptor protein and mRNA expression in the trigeminal ganglia, but not

  9. Comparative analysis of the aroma chemicals of Melissa officinalis using hydrodistillation and HS-SPME techniques

    Directory of Open Access Journals (Sweden)

    Shakeel-u- Rehman

    2017-05-01

    Full Text Available Headspace solid-phase micro extraction (HS-SPME coupled with gas chromatography–mass spectrometry (GC–MS has been used for the chemical analysis of Melissa officinalis (leaves cultivated in Institute Germplasm. The HS-SPME analysis led to the identification of 22 components constituting 99.1% of the total volatile constituents present in the leaves whereas its hydrodistillate led to the identification of 24 volatile constituents constituting 98.1% of the volatile material. The chemical composition of the SPME and hydrodistilled extract of M. officinalis leaves comprised mainly of oxygenated monoterpenes (78.5% and 57.8% respectively and sesquiterpene hydrocarbons (14.9% and 29.7% respectively. The major components identified in the HS-SPME extract were citronellal (31.1%, citronellol (18.3%, β-caryophyllene (12.0%, (E-citral (11.9%, (Z-citral (9.6%, geraniol (3.6%, (Z-β-ocimene (3.1% and 1-octen-3-ol (2.0% whereas hydrodistilled essential oil was rich in (Z-citral (19.6%, β-caryophyllene (13.2%, (E-citral (11.2%, citronellal (10.2%, germacrene-d (8.3%, δ-3-carene (5.0%, 6-methyl-5-hepten-2-one (3.7% and citronellyl acetate (3.7%. The comparative analysis of volatile constituents of M. officinalis leaf extract using HS-SPME and hydrodistillation techniques shows both qualitative as well as quantitative differences. The current study is the first report involving rapid analysis of volatile components of M. officinalis by HS-SPME.

  10. Synthesis of carbon nanotubes using the cobalt nanocatalyst by thermal chemical vapor deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Madani, S.S. [Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Zare, K. [Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Department of Chemistry, Shahid Beheshti University, Tehran (Iran, Islamic Republic of); Ghoranneviss, M. [Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Salar Elahi, A., E-mail: Salari_phy@yahoo.com [Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)

    2015-11-05

    The three main synthesis methods of Carbon nanotubes (CNTs) are the arc discharge, the laser ablation and the chemical vapour deposition (CVD) with a special regard to the latter one. CNTs were produced on a silicon wafer by Thermal Chemical Vapor Deposition (TCVD) using acetylene as a carbon source, cobalt as a catalyst and ammonia as a reactive gas. The DC-sputtering system was used to prepare cobalt thin films on Si substrates. A series of experiments was carried out to investigate the effects of reaction temperature and deposition time on the synthesis of the nanotubes. The deposition time was selected as 15 and 25 min for all growth temperatures. Energy Dispersive X-ray (EDX) measurements were used to investigate the elemental composition of the Co nanocatalyst deposited on Si substrates. Atomic Force Microscopy (AFM) was used to characterize the surface topography of the Co nanocatalyst deposited on Si substrates. The as-grown CNTs were characterized under Field Emission Scanning Electron Microscopy (FESEM) to study the morphological properties of CNTs. Also, the grown CNTs have been investigated by High Resolution Transmission Electron Microscopy (HRTEM) and Raman spectroscopy. The results demonstrated that increasing the temperature leads to increasing the diameter of CNTs. The ideal reaction temperature was 850 °C and the deposition time was 15 min. - Graphical abstract: FESEM images of CNTs grown on the cobalt catalyst at growth temperatures of (a) 850 °C, (b) 900 °C, (c) 950 °C and (d) 1000 °C during the deposition time of 15 min. - Highlights: • Carbon nanotubes (CNTs) were produced on a silicon wafer by TCVD technique. • EDX and AFM were used to investigate the elemental composition and surface topography. • FESEM was used to study the morphological properties of CNTs. • The grown CNTs have been investigated by HRTEM and Raman spectroscopy.

  11. MAKSIMA-CHEMIST: a program for Mass Action Kinetics Simulation by Automatic Chemical Equation Manipulation and Integration using Stiff Techniques

    International Nuclear Information System (INIS)

    Carver, M.B.; Hanley, D.V.; Chaplin, K.R.

    1979-02-01

    MAKSIMA-CHEMIST was written to compute the kinetics of simultaneous chemical reactions. The ordinary differential equations, which are automatically derived from the stated chemical equations, are difficult to integrate, as they are coupled in a highly nonlinear manner and frequently involve a large range in the magnitude of the reaction rates. They form a classic 'stiff' differential equaton set which can be integrated efficiently only by recently developed advanced techniques. The new program also contains provision for higher order chemical reactions, and has a dynamic storage and decision feature. This permits it to accept any number of chemical reactions and species, and choose an integraton scheme which will perform most efficiently within the available memory. Sparse matrix techniques are used when the size and structure of the equation set is suitable. Finally, a number of post-analysis options are available, including printer and Calcomp plots of transient response of selected species, and graphical representation of the reaction matrix. (auth)

  12. The composition-explicit distillation curve technique: Relating chemical analysis and physical properties of complex fluids.

    Science.gov (United States)

    Bruno, Thomas J; Ott, Lisa S; Lovestead, Tara M; Huber, Marcia L

    2010-04-16

    The analysis of complex fluids such as crude oils, fuels, vegetable oils and mixed waste streams poses significant challenges arising primarily from the multiplicity of components, the different properties of the components (polarity, polarizability, etc.) and matrix properties. We have recently introduced an analytical strategy that simplifies many of these analyses, and provides the added potential of linking compositional information with physical property information. This aspect can be used to facilitate equation of state development for the complex fluids. In addition to chemical characterization, the approach provides the ability to calculate thermodynamic properties for such complex heterogeneous streams. The technique is based on the advanced distillation curve (ADC) metrology, which separates a complex fluid by distillation into fractions that are sampled, and for which thermodynamically consistent temperatures are measured at atmospheric pressure. The collected sample fractions can be analyzed by any method that is appropriate. The analytical methods we have applied include gas chromatography (with flame ionization, mass spectrometric and sulfur chemiluminescence detection), thin layer chromatography, FTIR, corrosivity analysis, neutron activation analysis and cold neutron prompt gamma activation analysis. By far, the most widely used analytical technique we have used with the ADC is gas chromatography. This has enabled us to study finished fuels (gasoline, diesel fuels, aviation fuels, rocket propellants), crude oils (including a crude oil made from swine manure) and waste oils streams (used automotive and transformer oils). In this special issue of the Journal of Chromatography, specifically dedicated to extraction technologies, we describe the essential features of the advanced distillation curve metrology as an analytical strategy for complex fluids. Published by Elsevier B.V.

  13. Quantum chemical approaches: semiempirical molecular orbital and hybrid quantum mechanical/molecular mechanical techniques.

    Science.gov (United States)

    Bryce, Richard A; Hillier, Ian H

    2014-01-01

    The use of computational quantum chemical methods to aid drug discovery is surveyed. An overview of the various computational models spanning ab initio, density function theory, semiempirical molecular orbital (MO), and hybrid quantum mechanical (QM)/molecular mechanical (MM) methods is given and their strengths and weaknesses are highlighted, focussing on the challenge of obtaining the accuracy essential for them to make a meaningful contribution to drug discovery. Particular attention is given to hybrid QM/MM and semiempirical MO methods which have the potential to yield the necessary accurate predictions of macromolecular structure and reactivity. These methods are shown to have advanced the study of many aspects of substrate-ligand interactions relevant to drug discovery. Thus, the successful parametrization of semiempirical MO methods and QM/MM methods can be used to model noncovalent substrate-protein interactions, and to lead to improved scoring functions. QM/MM methods can be used in crystal structure refinement and are particularly valuable for modelling covalent protein-ligand interactions and can thus aid the design of transition state analogues. An extensive collection of examples from the areas of metalloenzyme structure, enzyme inhibition, and ligand binding affinities and scoring functions are used to illustrate the power of these techniques.

  14. Preparation of high surface area and high conductivity polyaniline nanoparticles using chemical oxidation polymerization technique

    Science.gov (United States)

    Budi, S.; Yusmaniar; Juliana, A.; Cahyana, U.; Purwanto, A.; Imaduddin, A.; Handoko, E.

    2018-03-01

    In this work, polyaniline nanoparticles were synthesized using a chemical oxidation polymerization technique. The ammonium peroxydisulfate (APS)/aniline ratio, APS dropping time, and polymerization temperature were optimized to increase the surface area and conductivity of the polyaniline.The Fourier-transform infrared (FTIR) spectrum confirmed the formation of emeraldine salt polyaniline. X-ray diffraction (XRD) patterns indicated that amorphous and crystalline phases of the polyaniline were formed with crystallinity less than 40%. Scanning electron microscope (SEM) micrographs showed that the finest nanoparticles with uniform size distribution were obtained at the polymerization temperature of 0°C. A surface area analyzer (SAA) showed that the highest Brunauer-Emmett-Teller surface area (SBET ) of 42.14 m2/gwas obtained from an APS/aniline ratio of 0.75 with a dropping time of 0 s at a polymerization temperature of 0°C. A four-point probe measurement conducted at 75–300K indicated relatively high conductivity of the semiconductor characteristic of the polyaniline.

  15. Studies on the remediation of environment contaminated with radioactive pollutants using the chemical separation technique

    Energy Technology Data Exchange (ETDEWEB)

    Kurotaki, Katsumi; Yonehara, Hidenori; Sahoo, S.K. [National Inst. of Radiological Sciences, Chiba (Japan); Ishii, Toshiaki [National Inst. of Radiological Sciences, Hitachinaka, Ibaraki (Japan). Lab. for Radioecology

    2001-12-01

    Remediation of soil and drinking water contaminated with radioactive nuclides is important for the mitigation of radiation exposure. Then we attempted to construct the remediation system including the dose estimation system using the chemical separation technique to remove pollutants from the environment. The information on air dose rate is important for assessment of risk from the radiation exposure. Then we measured the air dose rate and analysed the relationship between air dose rate and the contamination of soil at the area in Russia (Bryansk district) contaminated by Chernobyl Nuclear Power Plant accident. Moreover, we analysed the soil of Bryansk district on the concentration of rare earth elements, thorium and uranium and on the isotope ratio of strontium. On the other hand, we tried to develop the rapid measurement method of radioactivity of Sr-90 which is one of the dangerous radionuclides, because the method of radioactivity measurement in the literature is too time-consuming. It was reported recently that the molecules containing SH group form the covalent bond with gold atoms at the surface of gold plate and that crown ether compounds have strong affinity to strontium. Then we attempted to synthesize the crown ether containing SH group. In addition, we search the inorganic elements accumulated to special organisms of fishes and other animals in sea in order to find out new reagent for trace elements. Transition metal such as Co, Fe, Ni, Ti, V and Zn were detected from the intracellular granules in the bronchial heart of octopus. (author)

  16. Evaluating chemical extraction techniques for the determination of uranium oxidation state in reduced aquifer sediments

    Science.gov (United States)

    Stoliker, Deborah L.; Campbell, Kate M.; Fox, Patricia M.; Singer, David M.; Kaviani, Nazila; Carey, Minna; Peck, Nicole E.; Barger, John R.; Kent, Douglas B.; Davis, James A.

    2013-01-01

    Extraction techniques utilizing high pH and (bi)carbonate concentrations were evaluated for their efficacy in determining the oxidation state of uranium (U) in reduced sediments collected from Rifle, CO. Differences in dissolved concentrations between oxic and anoxic extractions have been proposed as a means to quantify the U(VI) and U(IV) content of sediments. An additional step was added to anoxic extractions using a strong anion exchange resin to separate dissolved U(IV) and U(VI). X-ray spectroscopy showed that U(IV) in the sediments was present as polymerized precipitates similar to uraninite and/or less ordered U(IV), referred to as non-uraninite U(IV) species associated with biomass (NUSAB). Extractions of sediment containing both uraninite and NUSAB displayed higher dissolved uranium concentrations under oxic than anoxic conditions while extractions of sediment dominated by NUSAB resulted in identical dissolved U concentrations. Dissolved U(IV) was rapidly oxidized under anoxic conditions in all experiments. Uraninite reacted minimally under anoxic conditions but thermodynamic calculations show that its propensity to oxidize is sensitive to solution chemistry and sediment mineralogy. A universal method for quantification of U(IV) and U(VI) in sediments has not yet been developed but the chemical extractions, when combined with solid-phase characterization, have a narrow range of applicability for sediments without U(VI).

  17. Precession technique and electron diffractometry as new tools for crystal structure analysis and chemical bonding determination

    International Nuclear Information System (INIS)

    Avilov, A.; Kuligin, K.; Nicolopoulos, S.; Nickolskiy, M.; Boulahya, K.; Portillo, J.; Lepeshov, G.; Sobolev, B.; Collette, J.P.; Martin, N.; Robins, A.C.; Fischione, P.

    2007-01-01

    We have developed a new fast electron diffractometer working with high dynamic range and linearity for crystal structure determinations. Electron diffraction (ED) patterns can be scanned serially in front of a Faraday cage detector; the total measurement time for several hundred ED reflections can be tens of seconds having high statistical accuracy for all measured intensities (1-2%). This new tool can be installed to any type of TEM without any column modification and is linked to a specially developed electron beam precession 'Spinning Star' system. Precession of the electron beam (Vincent-Midgley technique) reduces dynamical effects allowing also use of accurate intensities for crystal structure analysis. We describe the technical characteristics of this new tool together with the first experimental results. Accurate measurement of electron diffraction intensities by electron diffractometer opens new possibilities not only for revealing unknown structures, but also for electrostatic potential determination and chemical bonding investigation. As an example, we present detailed atomic bonding information of CaF 2 as revealed for the first time by precise electron diffractometry

  18. Tuning the morphology of metastable MnS films by simple chemical bath deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Dhandayuthapani, T. [Directorate of Distance Education, Alagappa University, Karaikudi 630004 (India); Girish, M. [Department of Physics, Alagappa University, Karaikudi 630004 (India); Sivakumar, R., E-mail: krsivakumar1979@yahoo.com [Directorate of Distance Education, Alagappa University, Karaikudi 630004 (India); Sanjeeviraja, C. [Department of Physics, Alagappa Chettiar College of Engineering and Technology, Karaikudi 630004 (India); Gopalakrishnan, R. [Department of Physics, Anna University, Chennai 600025 (India)

    2015-10-30

    Graphical abstract: - Highlights: • MnS films with diverse morphological features were prepared without any complexing agent. • The change in morphology of MnS films may be due to the “oriented aggregation”. • The dual role (as sulfur source and structure directing agent) of thiourea was observed. • Sulfur source concentration induced enhancement in the crystallization of films. - Abstract: In the present investigation, we have prepared the spherical particles, almond-like, and cauliflower-like morphological structures of metastable MnS films on glass substrate by chemical bath deposition technique at low temperature without using any complexing or chelating agent. The morphological change of MnS films with molar ratio may be due to the oriented aggregation of adjacent particles. The compositional purity of deposited film was confirmed by the EDAX study. X-ray diffraction and micro-Raman studies confirm the sulfur source concentration induced enhancement in the crystallization of films with metastable MnS phase (zinc-blende β-MnS, and wurtzite γ-MnS). The shift in PL emission peak with molar ratio may be due to the change in optical energy band gap of the MnS, which was further confirmed by the optical absorbance study. The paramagnetic behavior of the sample was confirmed by the M–H plot.

  19. Comparison of the Chemical Composition of “Cystoseira sedoides (Desfontaines C. Agardh” Volatile Compounds Obtained by Different Extraction Techniques

    Directory of Open Access Journals (Sweden)

    Naima Bouzidi

    2016-01-01

    Full Text Available The volatile fraction of the brown alga Cystoseira sedoides (Desfontaines C.Agardh is prepared from the crude extract through the following three extraction methods: Hydrodistillation (HD, focused microwave assisted hydrodistillation (FMAHD and supercritical fluid extraction (SFE. The volatile fractions are analyzed by gas chromatography-flame ionization detector-mass spectrometry (GC-FID-MS, the chemical components are identified on the basis of the comparison of their retention indices with literature and their mass spectra with those reported in commercial databases. The chemical composition of the volatile fractions obtained by different extraction techniques fall into three major chemical classes: fatty acids and derivatives, sesquiterpenes, and hydrocarbons and derivatives. Others Compounds belonging to different chemical classes are found in that chemical composition.

  20. Photoluminescence of nc-Si:Er thin films obtained by physical and chemical vapour deposition techniques: The effects of microstructure and chemical composition

    Energy Technology Data Exchange (ETDEWEB)

    Cerqueira, M.F., E-mail: fcerqueira@fisica.uminho.p [Departamento de Fisica, Universidade do Minho, Campus de Gualtar 4710-057 Braga (Portugal); Losurdo, M. [Institute of Inorganic Methodologies and of Plasmas, IMIP-CNR, Via Orabona n.4-70126 Bari (Italy); Stepikhova, M. [Institute for Physics of Microstructures RAS, 603600 Nizhnij Novgorod GSP-105 (Russian Federation); Alpuim, P.; Andres, G. [Departamento de Fisica, Universidade do Minho, Campus de Gualtar 4710-057 Braga (Portugal); Kozanecki, A. [Polish Academy of Sciences, Institute of Physics, PL-02668, Warsaw (Poland); Soares, M.J.; Peres, M. [Departamento de Fisica, Universidade de Aveiro, Campus de Santiago, 3700 Aveiro (Portugal)

    2009-08-31

    Erbium doped nanocrystalline silicon (nc-Si:Er) thin films were produced by reactive magnetron rf sputtering and by Er ion implantation into chemical vapor deposited Si films. The structure and chemical composition of films obtained by the two approaches were studied by micro-Raman scattering, spectroscopic ellipsometry and Rutherford backscattering techniques. Variation of deposition parameters was used to deposit films with different crystalline fraction and crystallite size. Photoluminescence measurements revealed a correlation between film microstructure and the Er{sup 3+} photoluminescence efficiency.

  1. Association of Odor Thresholds and Responses in Cerebral Blood Flow of the Prefrontal Area during Olfactory Stimulation in Patients with Multiple Chemical Sensitivity.

    Directory of Open Access Journals (Sweden)

    Kenichi Azuma

    Full Text Available Multiple chemical sensitivity (MCS is a disorder characterized by nonspecific and recurrent symptoms from various organ systems associated with exposure to low levels of chemicals. Patients with MCS process odors differently than controls do. Previously, we suggested that this odor processing was associated with increased regional cerebral blood flow (rCBF in the prefrontal area during olfactory stimulation using near-infrared spectroscopic (NIRS imaging. The aim of this study was to investigate the association of odor thresholds and changes in rCBF during olfactory stimulation at odor threshold levels in patients with MCS. We investigated changes in the prefrontal area using NIRS imaging and a T&T olfactometer during olfactory stimulation with two different odorants (sweet and fecal at three concentrations (zero, odor recognition threshold, and normal perceived odor level in 10 patients with MCS and six controls. The T&T olfactometer threshold test and subjective assessment of irritating and hedonic odors were also performed. The results indicated that the scores for both unpleasant and pungent odors were significantly higher for those for sweet odors at the normal perceived level in patients with MCS than in controls. The brain responses at the recognition threshold (fecal odor and normal perceived levels (sweet and fecal odors were stronger in patients with MCS than in controls. However, significant differences in the odor detection and recognition thresholds and odor intensity score between the two groups were not observed. These brain responses may involve cognitive and memory processing systems during past exposure to chemicals. Further research regarding the cognitive features of sensory perception and memory due to past exposure to chemicals and their associations with MCS symptoms is needed.

  2. Considerations Regarding the Opportunity of Using Psychological Techniques to Stimulate Solutions Characterized by Novelty and Inventive Step in TISR Transformers and Electric Motors with Shorted Moving Coil

    Directory of Open Access Journals (Sweden)

    Georgescu Daniel Ștefan

    2014-09-01

    Full Text Available This paper presents the appreciations and contributions regarding the use of psychological techniques to stimulate technical creativity with special reference to consonant association technique and inversion technique. The study is performed in the field of TISR transformers and electric motors with limited movement, starting from the analogy between a transformer and an electric motor with shorted coil. It approached a particular aspect of inversion technique in relation with the transformation of negative effects and results of laws, phenomena and processes into useful applications. The matter reffered to is related to the question: ,,why disadvantages and no advantages ?". At the end of the paper are presented and discussed some experimental models produced and studied by the authors in the Research Laboratory of Machines, Equipment and Drives at the University of Suceava and are exposed conclusions drawn from the experimental study and directions for future research.

  3. Anglo-Saxon animal husbandry techniques revealed though isotope and chemical variations in cattle teeth

    International Nuclear Information System (INIS)

    Evans, J.A.; Tatham, S.; Chenery, S.R.; Chenery, C.A.

    2007-01-01

    The Sr concentration and isotope composition of tooth enamel from domesticated animals from two neighbouring Anglo-Saxon settlements, at Empingham (6-7th century) and Ketton (10-12th century) in Rutland, central England, are compared both with each other, and with associated human populations. Data from the Empingham II site form discrete fields in Sr concentration and isotope composition space for cattle, pig and sheep with a partial overlap of the human and pig fields. By contrast there is significant overlap in all the animal and human data fields from the Ketton site. The differences in data distribution between the two sites are attributed to animal husbandry techniques, as the surface geology of the two areas is very similar, implying geological factors are an unlikely cause of the difference. It is suggested that the grazing and feeding patterns of animals at the Empingham II site were controlled and restricted, whereas at the Ketton site the animals grazed and foraged freely over a common area. Strontium isotope variation within cattle molars from the two settlements show marked differences that reflect the nature of their feeding and rearing. The enamel from a cattle molar from the Empingham II site has a well-defined, systematic variation of Sr isotope composition with Sr concentration, whereas no such patterns exist in a comparable cattle molar from Ketton. Chemical and O isotope variations in the cattle tooth from Empingham II show sympathetic variation of Sr and Ba concentrations with Sr isotope composition from cusp to cervix. The cusp has higher Sr and Ba concentrations log (Sr/Ca) ratio of -3.1 and 87 Sr/ 86 Sr ratio of 0.71151 where as the cervical region of the enamel has log (Sr/Ca) = -3.3 and 87 Sr/ 86 Sr = 0.71061

  4. Anglo-Saxon animal husbandry techniques revealed though isotope and chemical variations in cattle teeth

    Energy Technology Data Exchange (ETDEWEB)

    Evans, J.A. [NERC Isotope Geosciences Laboratory, BGS, Keyworth, Nottingham NG12 5GG (United Kingdom)], E-mail: je@nigl.nerc.ac.uk; Tatham, S. [School of Archaeology and Ancient History, University of Leicester, Leicester LE1 7RH (United Kingdom); Chenery, S.R. [British Geological Survey, Keyworth, Nottingham NG12 5GG (United Kingdom); Chenery, C.A. [NERC Isotope Geosciences Laboratory, BGS, Keyworth, Nottingham NG12 5GG (United Kingdom)

    2007-09-15

    The Sr concentration and isotope composition of tooth enamel from domesticated animals from two neighbouring Anglo-Saxon settlements, at Empingham (6-7th century) and Ketton (10-12th century) in Rutland, central England, are compared both with each other, and with associated human populations. Data from the Empingham II site form discrete fields in Sr concentration and isotope composition space for cattle, pig and sheep with a partial overlap of the human and pig fields. By contrast there is significant overlap in all the animal and human data fields from the Ketton site. The differences in data distribution between the two sites are attributed to animal husbandry techniques, as the surface geology of the two areas is very similar, implying geological factors are an unlikely cause of the difference. It is suggested that the grazing and feeding patterns of animals at the Empingham II site were controlled and restricted, whereas at the Ketton site the animals grazed and foraged freely over a common area. Strontium isotope variation within cattle molars from the two settlements show marked differences that reflect the nature of their feeding and rearing. The enamel from a cattle molar from the Empingham II site has a well-defined, systematic variation of Sr isotope composition with Sr concentration, whereas no such patterns exist in a comparable cattle molar from Ketton. Chemical and O isotope variations in the cattle tooth from Empingham II show sympathetic variation of Sr and Ba concentrations with Sr isotope composition from cusp to cervix. The cusp has higher Sr and Ba concentrations log (Sr/Ca) ratio of -3.1 and {sup 87}Sr/{sup 86}Sr ratio of 0.71151 where as the cervical region of the enamel has log (Sr/Ca) = -3.3 and {sup 87}Sr/{sup 86}Sr = 0.71061.

  5. Changes in cerebral blood flow during olfactory stimulation in patients with multiple chemical sensitivity: a multi-channel near-infrared spectroscopic study.

    Directory of Open Access Journals (Sweden)

    Kenichi Azuma

    Full Text Available Multiple chemical sensitivity (MCS is characterized by somatic distress upon exposure to odors. Patients with MCS process odors differently from controls. This odor-processing may be associated with activation in the prefrontal area connecting to the anterior cingulate cortex, which has been suggested as an area of odorant-related activation in MCS patients. In this study, activation was defined as a significant increase in regional cerebral blood flow (rCBF because of odorant stimulation. Using the well-designed card-type olfactory test kit, changes in rCBF in the prefrontal cortex (PFC were investigated after olfactory stimulation with several different odorants. Near-infrared spectroscopic (NIRS imaging was performed in 12 MCS patients and 11 controls. The olfactory stimulation test was continuously repeated 10 times. The study also included subjective assessment of physical and psychological status and the perception of irritating and hedonic odors. Significant changes in rCBF were observed in the PFC of MCS patients on both the right and left sides, as distinct from the center of the PFC, compared with controls. MCS patients adequately distinguished the non-odorant in 10 odor repetitions during the early stage of the olfactory stimulation test, but not in the late stage. In comparison to controls, autonomic perception and negative affectivity were poorer in MCS patients. These results suggest that prefrontal information processing associated with odor-processing neuronal circuits and memory and cognition processes from past experience of chemical exposure play significant roles in the pathology of this disorder.

  6. Microfluidic culture chamber for the long-term perfusion and precise chemical stimulation of organotypic brain tissue slices

    DEFF Research Database (Denmark)

    Caicedo, H. H.; Vignes, M.; Brugg, B.

    2010-01-01

    We have developed a microfluidic perfusion-based culture system to study long-term in-vitro responses of organo-typic brain slices exposed to localized neurochemical stimulation. Using this microperfusion chamber we show that hip-pocampal organotypic brain slices cultures grown on nitrocellulose ...

  7. Nanolithography and nanochemistry: probe-related patterning techniques and chemical modification for nanometer-sized devices

    NARCIS (Netherlands)

    Wouters, D.; Schubert, U.S.

    2004-01-01

    The size regime for devices produced by photolithographic techniques is limited. Therefore, other patterning techniques have been intensively studied to create smaller structures. Scanning-probe-based patterning techniques, such as dip-pen lithography, local force-induced patterning, and local-probe

  8. Review of analytical techniques to determine the chemical forms of vapours and aerosols released from overheated fuel

    International Nuclear Information System (INIS)

    Bowsher, B.R.; Nichols, A.L.

    1989-12-01

    A comprehensive review has been undertaken of appropriate analytical techniques to monitor and measure the chemical effects that occur in large-scale tests designed to study severe reactor accidents. Various methods have been developed to determine the chemical forms of the vapours, aerosols and deposits generated during and after such integral experiments. Other specific techniques have the long-term potential to provide some of the desired data in greater detail, although considerable efforts are still required to apply these techniques to the study of radioactive debris. Such in-situ and post-test methods of analysis have been also assessed in terms of their applicability to the analysis of samples from the Phebus-FP tests. The recommended in-situ methods of analysis are gamma-ray spectroscopy, potentiometry, mass spectrometry, and Raman/UV-visible absorption spectroscopy. Vapour/aerosol and deposition samples should also be obtained at well-defined time intervals during each experiment for subsequent post-test analysis. No single technique can provide all the necessary chemical data from these samples, and the most appropriate method of analysis involves a complementary combination of autoradiography, AES, IR, MRS, SEMS/EDS, SIMS/LMIS, XPS and XRD

  9. Does vagal nerve stimulation affect body composition and metabolism? Experimental study of a new potential technique in bariatric surgery.

    Science.gov (United States)

    Sobocki, Jacek; Fourtanier, Gilles; Estany, Joan; Otal, Phillipe

    2006-02-01

    It has been shown that vagal nerve stimulation (VNS) can affect body mass. The aim of this study was to evaluate effect of VNS on body mass, body composition, metabolic rate, and plasma leptin and IGF-I levels. Eight female pigs were included in the study. Under general anesthesia, a bipolar electrode was implanted on the anterior vagal nerve by laparoscopy. Group A was treated by VNS, and group B was the control. After 4 weeks, stimulation was discontinued in group A and started in group B. The following parameters were evaluated: body mass, body composition, metabolic rate, plasma leptin and IGF-1 levels and intramuscular fat content (IMF). VNS attenuated body weight gain (2.28 +/- 3.47 kg vs 14.04 +/- 6.75 kg; P = .0112, for stimulation and nonstimulation periods, respectively), backfat gain (0.04 +/- 0.26 mm vs 2.31 +/- 1.12 mm) and IMF gain (-3.76 +/- 6.06 mg/g MS vs 7.24 +/- 12.90 mg/g MS; P = .0281). VNS resulted in lower backfat depth/loin muscle area ratio (0.33 +/- 0.017 vs 0.38 +/- 0.35; P = .0476). Lower plasma IGF-I concentration was found after VNS (-3.67 +/- -11.55 ng/mL vs 9.86 +/- 10.74 ng/mL; P = .0312). No significant changes in other parameters were observed. VNS affects body weight mainly at the expense of body fat resources; however, metabolic rate is not affected.

  10. Laser speckle technique to study the effect of chemical pre-treatment on the quality of minimally processed apples

    International Nuclear Information System (INIS)

    Minz, Preeti D; Nirala, A K

    2016-01-01

    In the present study, the laser speckle technique has been used for the quality evaluation of chemically treated cut apples. Chemical pre-treatment includes 1% (w/v) solution of citric acid (CA), sodium chloride (SC), and a combination of CA and sodium chloride (CS). The variation in weight loss, respiration rate, total soluble solids (TSS), titratable acidity (TA), and absorbance of chemically treated cut apples stored at 5 °C was monitored for 11 d. The speckle grain size was calculated by an autocovariance method from the speckled images of freshly cut chemically treated apples. The effect of chemicals on TSS and the TA content variation of the cut apples were well correlated to the linear speckle grain size. Circular degree of polarization confirms the presence of a small scatterer and hence Rayleigh diffusion region. For all the treated cut apples, a decrease in the concentration of small particles nearly after the mid-period of storage results in the fast decay of circular degree of polarization. For non-invasive and fast analysis of the chemical constituent of fruits during minimal processing, the laser speckle can be practically used in the food industry. (paper)

  11. Laser speckle technique to study the effect of chemical pre-treatment on the quality of minimally processed apples

    Science.gov (United States)

    Minz, Preeti D.; Nirala, A. K.

    2016-04-01

    In the present study, the laser speckle technique has been used for the quality evaluation of chemically treated cut apples. Chemical pre-treatment includes 1% (w/v) solution of citric acid (CA), sodium chloride (SC), and a combination of CA and sodium chloride (CS). The variation in weight loss, respiration rate, total soluble solids (TSS), titratable acidity (TA), and absorbance of chemically treated cut apples stored at 5 °C was monitored for 11 d. The speckle grain size was calculated by an autocovariance method from the speckled images of freshly cut chemically treated apples. The effect of chemicals on TSS and the TA content variation of the cut apples were well correlated to the linear speckle grain size. Circular degree of polarization confirms the presence of a small scatterer and hence Rayleigh diffusion region. For all the treated cut apples, a decrease in the concentration of small particles nearly after the mid-period of storage results in the fast decay of circular degree of polarization. For non-invasive and fast analysis of the chemical constituent of fruits during minimal processing, the laser speckle can be practically used in the food industry.

  12. Analytical technique to address terrorist threats by chemical weapons of mass destruction

    Science.gov (United States)

    Dempsey, Patrick M.

    1997-01-01

    Terrorism is no longer an issue without effect on the American mind. We now live with the same concerns and fears that have been commonplace in other developed and third world countries for a long time. Citizens of other countries have long lived with the specter of terrorism and now the U.S. needs to be concerned and prepared for terrorist activities.T he terrorist has the ability to cause great destructive effects by focusing their effort on unaware and unprepared civilian populations. Attacks can range from simple explosives to sophisticated nuclear, chemical and biological weapons. Intentional chemical releases of hazardous chemicals or chemical warfare agents pose a great threat because of their ready availability and/or ease of production, and their ability to cause widespread damage. As this battlefront changes from defined conflicts and enemies to unnamed terrorists, we must implement the proper analytical tools to provide a fast and efficient response. Each chemical uses in a terrorists weapon leaves behind a chemical signature that can be used to identify the materials involved and possibly lead investigators to the source and to those responsible. New tools to provide fast and accurate detection for battlefield chemical and biological agent attack are emerging. Gas chromatography/mass spectrometry (GC/MS) is one of these tools that has found increasing use by the military to respond to chemical agent attacks. As the technology becomes smaller and more portable, it can be used by law enforcement personnel to identify suspected terrorist releases and to help prepare the response; define contaminated areas for evacuation and safety concerns, identify the proper treatment of exposed or affected civilians, and suggest decontamination and cleanup procedures.

  13. Yield of Peas Treated with Compost and Chemical Fertilizer Using 15N Technique

    International Nuclear Information System (INIS)

    El-Degwy, S.M.A.

    2011-01-01

    A field experiment was carried out to evaluate the yield of peas treated with organic compost and mineral N fertilizer under sandy soil conditions. The obtained results showed that all the tested vegetative growth parameters, i.e. fresh and dry weight of leaves, root and pods of pea plants, were significantly increased with increasing the levels of mineral N fertilizer from 20 up to 50 kg N ha-1 either solely or in combination with compost. Nitrogen, phosphorus and potassium uptake by pea plants were ranked as follow: chemical N fertilize > compost + chemical N fertilize > compost. Organic additives either alone or in combination with chemical fertilizer had enhanced Ndff uptake by pods over aerial parts and roots while reversible trend was noticed with sole application of chemical fertilizer. Nitrogen derived from compost (Ndfc) and uptake by aerial parts followed by pods were enhanced by addition of organic plus chemical fertilizers comparable to sole addition of organic compost. In other term, chemical fertilizer had enhanced the portion of N derived from organic compost

  14. CHEMICALS

    CERN Multimedia

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  15. [Construction of chemical information database based on optical structure recognition technique].

    Science.gov (United States)

    Lv, C Y; Li, M N; Zhang, L R; Liu, Z M

    2018-04-18

    To create a protocol that could be used to construct chemical information database from scientific literature quickly and automatically. Scientific literature, patents and technical reports from different chemical disciplines were collected and stored in PDF format as fundamental datasets. Chemical structures were transformed from published documents and images to machine-readable data by using the name conversion technology and optical structure recognition tool CLiDE. In the process of molecular structure information extraction, Markush structures were enumerated into well-defined monomer molecules by means of QueryTools in molecule editor ChemDraw. Document management software EndNote X8 was applied to acquire bibliographical references involving title, author, journal and year of publication. Text mining toolkit ChemDataExtractor was adopted to retrieve information that could be used to populate structured chemical database from figures, tables, and textual paragraphs. After this step, detailed manual revision and annotation were conducted in order to ensure the accuracy and completeness of the data. In addition to the literature data, computing simulation platform Pipeline Pilot 7.5 was utilized to calculate the physical and chemical properties and predict molecular attributes. Furthermore, open database ChEMBL was linked to fetch known bioactivities, such as indications and targets. After information extraction and data expansion, five separate metadata files were generated, including molecular structure data file, molecular information, bibliographical references, predictable attributes and known bioactivities. Canonical simplified molecular input line entry specification as primary key, metadata files were associated through common key nodes including molecular number and PDF number to construct an integrated chemical information database. A reasonable construction protocol of chemical information database was created successfully. A total of 174 research

  16. Chemical composition of a yellowish rainfall by the application of PIXE and micro-PIXE technique

    International Nuclear Information System (INIS)

    Ma, C.-J.

    2006-01-01

    Information of the chemical properties of rain fallen during the Asian dust (AD) event will help us to better understand the wet scavenging processes of dust particles. In this study, the chemical characteristics of rainwater and individual raindrops fallen during the AD storm have been investigated. The yellowish rainwater and individual raindrops were collected simultaneously in Kyoto, Japan on 7 April 2001. Particle induced X-ray emission (PIXE) was employed in the determination of chemical properties of soluble and insoluble fractions of rainwater. In addition, micro-PIXE was applied to the chemical analysis of residual materials retained in the initial individual raindrops. The pH level of yellowish rainwater was measured around 6.7. In compliance with the general expectation, major components in rainwater were of soil-origin such as Si, K, Ca, Ti and Fe. These soil-related components contributed to as much as 92% of total elemental composition in both soluble and insoluble fractions. By scanning a micro-beam, the residual particle cluster in individual raindrops was reconstructed in terms of an elemental map. This visualized elemental map in fact enabled us not only to estimate the chemical mixing state of raindrop residual particles but also to presume the wet scavenging of dust particles by rainfall

  17. Investigation of geothermal fields in himalayan range in pakistan using isotope and chemical techniques

    International Nuclear Information System (INIS)

    Ahmad, M.; Sheikh, M.R.; Akram, W.; Tasneem, M.A.; Iqbal, N.; Latif, Z.

    2007-07-01

    There are many geothermal sites in Himalayan belt of Pakistan having low to high temperatures(boiling water). Isotopes and geochemical techniques were applied to investigate the origin, subsurface history and reservoir temperatures of geothermal fields at Tatta Pani and Tato lying along Main Mantle Thrust, Murtazabad along Main Karakoram Thrust and Kotli in the area of overlapping thrusts: Punjal Thrust, Main Boundary Thrust and the Himalaya Frontal Thrust. Discharge of the springs varies from 30 to 2000 liters per minute with the surface temperature from 47.3 to 92 degree C. Two sets of water samples were collected from these fields. The samples were analyzed for various isotopes (O/sup 18/, H/sup 2/ and H/sup 3/ of water; C/sup 13/ of dissolved inorganic carbon; S/sup 34/ and O/sup 18/ of dissolved sulphates); and water chemistry. The thermal waters of the Northern Areas of Pakistan are generally neutral to slightly alkaline and have low dissolved contents. Sodium is the dominant cation in all the cases. In terms of anions, HCO/sub 3/ is dominating. Source of recharge is meteoric water (rains and/or snow-melt). The dominant process of cooling is conduction at Tatta Pani, Tato, and Murtazabad. Shallow groundwater is mixing with the thermal springs in different proportions at Murtazabad, while there is no mixing in the thermal waters of Tatta Pani and Tato. The equilibrium temperature of the thermal end-member at Murtazabad is in the range of 185- 225 degree C and the isochemical-mixing model based on the Na-K and quartz geothermometers estimates 227 degree C temperature. O/sup 18/ (SO/sub 4/-H/sub 2/O) geothermometer indicates equilibrium temperatures (before mixing) above I85 degree C. The dissolved silica vs. enthalpy plot suggests heat losses through conduction from the original temperature about 245 degree C. The reservoir temperatures of Tatta Pani (100-130 degree C) determined by the Na-K, K-Mg and quartz geothermometers are in good agreement. O/sup 18/ (SO

  18. Use of radioactive double labelling technique in the chemical analysis of the mediators of cellular immunity

    International Nuclear Information System (INIS)

    Sorg, C.

    1978-01-01

    Radioactive double labelling was adapted for the analysis of mediators of cellular immunity. Two identical lymphocyte cultures were simultaneously labelled with [ 3 H]- or [ 14 C] leucine. Each of the cultures was stimulated with antigen or mitogen. The combined supernatants were then subjected to various fractionation procedures. By determining the isotope ratio in each fraction it is possible to identify those products of activated lymphocytes that have been produced either de novo or in increased amounts. The method proved sensitive enough to detect lymphocyte activation products in supernatants of activated lymphocyte cultures from guinea pig, mouse, and man

  19. Chemically intuited, large-scale screening of MOFs by machine learning techniques

    Science.gov (United States)

    Borboudakis, Giorgos; Stergiannakos, Taxiarchis; Frysali, Maria; Klontzas, Emmanuel; Tsamardinos, Ioannis; Froudakis, George E.

    2017-10-01

    A novel computational methodology for large-scale screening of MOFs is applied to gas storage with the use of machine learning technologies. This approach is a promising trade-off between the accuracy of ab initio methods and the speed of classical approaches, strategically combined with chemical intuition. The results demonstrate that the chemical properties of MOFs are indeed predictable (stochastically, not deterministically) using machine learning methods and automated analysis protocols, with the accuracy of predictions increasing with sample size. Our initial results indicate that this methodology is promising to apply not only to gas storage in MOFs but in many other material science projects.

  20. Heterogeneous chemical kinetics by modulated molecular beam mass spectrometry: limitations of technique

    International Nuclear Information System (INIS)

    Olander, D.R.

    1977-01-01

    The advantages and limitations of modulated molecular beam, mass spectrometry as applied to the study of heterogeneous chemical kinetics are reviewed. The process of deducing a model of the surface reaction from experimental data is illustrated by analysis of the hydrogen reduction of uranium dioxide

  1. From Technique of Tattooing to Biokinetics and Toxicology of Injected Tattoo Ink Particles and Chemicals

    DEFF Research Database (Denmark)

    Serup, Jørgen

    2017-01-01

    by banning potentially critical chemicals hitherto has been unsuccessful due to lacking documentation of clinical and epidemiological relevance and because the tattoo industry is already internationally established, free, and in the ownership of the people. Doctors treating patients with tattoo complications...

  2. Chemical or electrochemical techniques, followed by ion exchange, for recycle of textile dye wastewater.

    Science.gov (United States)

    Raghu, S; Ahmed Basha, C

    2007-10-22

    This paper examines the use of chemical or electrocoagulation treatment process followed by ion-exchange process of the textile dye effluent. The dye effluent was treated using polymeric coagulant (cationic dye-fixing agent) or electrocoagulation (iron and aluminum electrode) process under various conditions such as various current densities and effect of pH. Efficiencies of COD reduction, colour removal and power consumption were studied for each process. The chemical or electrochemical treatment are indented primarily to remove colour and COD of wastewater while ion exchange is used to further improve the removal efficiency of the colour, COD, Fe concentration, conductivity, alkalinity and total dissolved solids (TDS). From the results chemical coagulation, maximum COD reduction of about 81.3% was obtained at 300 mg/l of coagulant whereas in electrocoagulation process, maximum COD removal of about 92.31% (0.25 A/dm2) was achieved with energy consumption of about 19.29 k Wh/kg of COD and 80% (1A/dm(2)) COD removal was obtained with energy consumption of about 130.095 k Wh/kg of COD at iron and aluminum electrodes, respectively. All the experimental results, throughout the present study, have indicated that chemical or electrocoagulation treatment followed by ion-exchange methods were very effective and were capable of elevating quality of the treated wastewater effluent to the reuse standard of the textile industry.

  3. Effects of flotation-restricted environmental stimulation technique on stress-related muscle pain: what makes the difference in therapy--attention-placebo or the relaxation response?

    Science.gov (United States)

    Bood, Sven A; Sundequist, Ulf; Kjellgren, Anette; Nordstrom, Gun; Norlander, Torsten

    2005-01-01

    The purpose of the present study was to examine the potential effects of attention-placebo on flotation tank therapy. Flotation-restricted environmental stimulation technique is a method whereby an individual lies in a floating tank and all stimuli are reduced to a minimum. Thirty-two patients were diagnosed as having stress-related muscular pain. In addition, 16 of the participants had received the diagnosis of burnout depression. The patients were treated with flotation-restricted environmental stimulation technique for six weeks. One-half of the patients were also given special attention for 12 weeks (high attention), while the remainder received attention for only six weeks (normal attention). The participants exhibited lowered blood pressure, reduced pain, anxiety, depression, stress and negative affectivity, as well as increased optimism, energy and positive affectivity. The results were largely unaffected by the degree of attention-placebo or diagnosis. It was concluded that flotation therapy is an effective, noninvasive method for treating stress-related pain, and that the method is not more affected by placebo than by other methods currently used in pain treatment. The treatment of both burnout depression and pain related to muscle tension constitutes a major challenge for the patient as well as the care provider, an area in which great gains can be made if the treatment is effective. Flotation therapy may constitute an integral part of such treatment.

  4. Evaluation and Optimization Study on a Hybrid EOR Technique Named as Chemical-Alternating-Foam Floods

    Directory of Open Access Journals (Sweden)

    Xu Xingguang

    2017-01-01

    Full Text Available This work presents a novel Enhanced Oil Recovery (EOR method called Chemical-Alternating-Foam (CAF floods in order to overcome the drawbacks of the conventional foam flooding such as insufficient amount of in-situ foams, severe foam collapse and surfactant retention. The first part of this research focused on the comparison of conventional foam floods and CAF floods both of which had the same amount of gas and chemicals. It showed that: (1 CAF floods possessed the much greater Residual Resistance Factor (RRF at elevated temperature; (2 the accumulative oil recovery of the CAF floods was 10%-15% higher than that of the conventional foam flooding. After 1.8 Pore Volume (PV injection, the oil recovery reached the plateau for both methods; (3 CAF floods yielded the most amount of incremental oil at the 98% water cut (water content in the effluent, while the continuous foam floods achieved the best performance at 60% water cut. The second part of this work determined the optimal foam quality (gas/liquid ratio or the volume percent gas within foam, chemical/foam slug size ratio, cycle number and injection sequence for the CAF floods. It was found that the CAF was endowed with the peak performance if the foam quality, chemical/foam slug size ratio, cycle number was fixed at 80%, 1:1 and 3 respectively with the chemical slug being introduced ahead of the foam slug. Through systematic and thorough research, the proposed hybrid process has been approved to be a viable and effective method significantly strengthening the conventional foam flooding.

  5. Groundwater recharge studies using isotope-chemical techniques in wadi gharandal, sinai peninsula(E G))

    International Nuclear Information System (INIS)

    Awad, M.A.A.; Salem, W.M.; Ezzeldin

    1999-01-01

    Wadi Gharandal lies on southwestern part of sinai peninsula with its outlets into the Gulf of suez. Eight groundwater samples were collected from quaternary aquifer in wadi gharandal to identify the sources of replenishment and evaluation of its water quality. The variation in chemical composition of water samples is due to water-rock interaction and the effect of sea spray. The distribution of chemical species in the examined groundwater samples is controlled by geography and climate conditions prevailing in the area of study. The salinity increase towards the gulf of suez. The isotopic data indicate that precipitation and floods are considered to be the main sources of recharge in this area. The investigated groundwater samples are found to be suitable for irrigation purposes based on sodium adsorption ratio (SAR) and unsuitable for domestic usages due to high salinity and hardness values

  6. Implementing systematic review techniques in chemical risk assessment: Challenges, opportunities and recommendations.

    Science.gov (United States)

    Whaley, Paul; Halsall, Crispin; Ågerstrand, Marlene; Aiassa, Elisa; Benford, Diane; Bilotta, Gary; Coggon, David; Collins, Chris; Dempsey, Ciara; Duarte-Davidson, Raquel; FitzGerald, Rex; Galay-Burgos, Malyka; Gee, David; Hoffmann, Sebastian; Lam, Juleen; Lasserson, Toby; Levy, Len; Lipworth, Steven; Ross, Sarah Mackenzie; Martin, Olwenn; Meads, Catherine; Meyer-Baron, Monika; Miller, James; Pease, Camilla; Rooney, Andrew; Sapiets, Alison; Stewart, Gavin; Taylor, David

    2016-01-01

    Systematic review (SR) is a rigorous, protocol-driven approach designed to minimise error and bias when summarising the body of research evidence relevant to a specific scientific question. Taking as a comparator the use of SR in synthesising research in healthcare, we argue that SR methods could also pave the way for a "step change" in the transparency, objectivity and communication of chemical risk assessments (CRA) in Europe and elsewhere. We suggest that current controversies around the safety of certain chemicals are partly due to limitations in current CRA procedures which have contributed to ambiguity about the health risks posed by these substances. We present an overview of how SR methods can be applied to the assessment of risks from chemicals, and indicate how challenges in adapting SR methods from healthcare research to the CRA context might be overcome. Regarding the latter, we report the outcomes from a workshop exploring how to increase uptake of SR methods, attended by experts representing a wide range of fields related to chemical toxicology, risk analysis and SR. Priorities which were identified include: the conduct of CRA-focused prototype SRs; the development of a recognised standard of reporting and conduct for SRs in toxicology and CRA; and establishing a network to facilitate research, communication and training in SR methods. We see this paper as a milestone in the creation of a research climate that fosters communication between experts in CRA and SR and facilitates wider uptake of SR methods into CRA. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Quantitative chemical analysis of lead in canned chillis by spectrophotometric and nuclear techniques

    International Nuclear Information System (INIS)

    Sanchez Paz, L.A.

    1991-01-01

    The objectives of this work are the quantification of lead contents in two types of canned chilli of three trademarks, determining its inside of maximum permissible level (2 ppm), comparing moreover two trademarks that have flask and canned presentation for to determine the filling effect in the final content of lead, moreover make a comparative study of the techniques using on base to exactitude, linearity and sensibility. The techniques used were atomic absorption spectrophotometry, plasma emission spectrometry and x-ray fluorescence. The preliminary treatment of the samples was by calcination, continued of the ashes dissolution in acid medium, for later gauge a determinate volume for analyze by atomic absorption and plasma emission. For the analysis by x-ray fluorescence, after solubilyzing ashes, its precipitate the lead with PCDA (Pyrrolidine carbodithioic ammonium acid) then its filtered, filter paper is dried and counted directly. The standards preparation is made following the same procedure as in samples using lead titrisol solution. For each technique the recovery percent is determined by the addition of enough know amount. For each technique calibration curves are plotted been determined that the three are lineal in the established range of work. The recovery percent in three cases is superior to ninety five percent. By means of a variance analysis it was determined that lead contain in samples do not exceed two ppm., and the lead content in canned chillis is superior to contained in glass containers (1.7, 0.4 ppm respectively). X-ray fluorescence analysis is different to the attained results by the other two techniques due to its sensibility is less. The most advisable techniques for this kind of analysis are atomic absorption spectrophotometry and plasma emission. (Author)

  8. New radioimmunoassay for follicle-stimulating hormone in macaques: ovulatory menstrual cycles. [/sup 125/I tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Hodgen, G.D.; Wilks, J.W.; Vaitukaitis, J.L.; Chen, H.C.; Papkoff, H.; Ross, G.

    1976-07-01

    A sensitive and specific radioimmunoassay system for macaque follicle-stimulating hormone (mFSH) was developed utilizing an antiserum (H-31) prepared in a rabbit against purified ovine FSH as the immunogen. Sera from castrated female, adult male, and juvenile rhesus monkeys, as well as urinary extracts from castrated rhesus and bonnet monkeys, were used to demonstrate parallelism with a standard of partially purified monkey pituitary gonadotropins (LER-M-907-D). An extract of baboon pituitary tissue also showed parallelism with the reference standard. A highly purified pituitary extract (WP-X-105-28), containing approximately 75 percent macaque luteinizing hormone (mLH) and 1 percent mFSH, was used to demonstrate the specificity of this mFSH assay system. Sera and urinary extracts obtained from hypophysectomized monkeys did not show cross-reactivity in the assay. Macaque chorionic gonadotropin (mCG) did not produce an inhibition curve in the assay, as determined from serum samples and urinary extracts collected from pregnant monkeys at the time of peak mCG secretion. Serum concentrations of mFSH were suppressed in ovariectomized monkeys by the administration of ethinyl estradiol for 3 days, but returned to near pretreatment values by 96 h after the last estradiol administration. The determination of serum mFSH concentrations in daily blood samples obtained from 20 rhesus monkeys throughout ovulatory menstrual cycles revealed a pattern similar to that previously reported for the rhesus monkey and the woman. The peak value of serum mFSH during the menstrual cycle coincided with the midcycle surge of mLH in each case. The gonadotropin peaks were preceded by increasing serum concentrations of estradiol and followed by rises in the serum concentrations of progesterone.

  9. Combining QSAR Modeling and Text-Mining Techniques to Link Chemical Structures and Carcinogenic Modes of Action.

    Science.gov (United States)

    Papamokos, George; Silins, Ilona

    2016-01-01

    There is an increasing need for new reliable non-animal based methods to predict and test toxicity of chemicals. Quantitative structure-activity relationship (QSAR), a computer-based method linking chemical structures with biological activities, is used in predictive toxicology. In this study, we tested the approach to combine QSAR data with literature profiles of carcinogenic modes of action automatically generated by a text-mining tool. The aim was to generate data patterns to identify associations between chemical structures and biological mechanisms related to carcinogenesis. Using these two methods, individually and combined, we evaluated 96 rat carcinogens of the hematopoietic system, liver, lung, and skin. We found that skin and lung rat carcinogens were mainly mutagenic, while the group of carcinogens affecting the hematopoietic system and the liver also included a large proportion of non-mutagens. The automatic literature analysis showed that mutagenicity was a frequently reported endpoint in the literature of these carcinogens, however, less common endpoints such as immunosuppression and hormonal receptor-mediated effects were also found in connection with some of the carcinogens, results of potential importance for certain target organs. The combined approach, using QSAR and text-mining techniques, could be useful for identifying more detailed information on biological mechanisms and the relation with chemical structures. The method can be particularly useful in increasing the understanding of structure and activity relationships for non-mutagens.

  10. Combining QSAR Modeling and Text-Mining Techniques to Link Chemical Structures and Carcinogenic Modes of Action

    Science.gov (United States)

    Papamokos, George; Silins, Ilona

    2016-01-01

    There is an increasing need for new reliable non-animal based methods to predict and test toxicity of chemicals. Quantitative structure-activity relationship (QSAR), a computer-based method linking chemical structures with biological activities, is used in predictive toxicology. In this study, we tested the approach to combine QSAR data with literature profiles of carcinogenic modes of action automatically generated by a text-mining tool. The aim was to generate data patterns to identify associations between chemical structures and biological mechanisms related to carcinogenesis. Using these two methods, individually and combined, we evaluated 96 rat carcinogens of the hematopoietic system, liver, lung, and skin. We found that skin and lung rat carcinogens were mainly mutagenic, while the group of carcinogens affecting the hematopoietic system and the liver also included a large proportion of non-mutagens. The automatic literature analysis showed that mutagenicity was a frequently reported endpoint in the literature of these carcinogens, however, less common endpoints such as immunosuppression and hormonal receptor-mediated effects were also found in connection with some of the carcinogens, results of potential importance for certain target organs. The combined approach, using QSAR and text-mining techniques, could be useful for identifying more detailed information on biological mechanisms and the relation with chemical structures. The method can be particularly useful in increasing the understanding of structure and activity relationships for non-mutagens. PMID:27625608

  11. Growth and characterization of yttrium iron garnet films on Si substrates by Chemical Solution Deposition (CSD) technique

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Xin; Chen, Ying; Wang, Genshui [Key Laboratory of Inorganic Function Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 1295 Dingxi Rd., Shanghai 200050 (China); Zhang, Yuanyuan [Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, 500 Dongchuan Rd., Shanghai 200241 (China); Ge, Jun [Key Laboratory of Inorganic Function Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 1295 Dingxi Rd., Shanghai 200050 (China); Tang, Xiaodong [Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, 500 Dongchuan Rd., Shanghai 200241 (China); Ponchel, Freddy; Rémiens, Denis [Institute of Electronics, Microelectronics and Nanotechnology (IEMN)–DOAE, UMR CNRS 8520, Université des Sciences et Technologies de Lille, 59652 Villeneuve d’Ascq Cedex (France); Dong, Xianlin, E-mail: xldong@mail.sic.ac.cn [Key Laboratory of Inorganic Function Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 1295 Dingxi Rd., Shanghai 200050 (China)

    2016-06-25

    Yttrium Iron Garnet (YIG) films were prepared on Si substrates by Chemical Solution Deposition (CSD) technique using acetic acid and deionized water as solvents. Well-crystallized and crack-free YIG films were obtained when annealed at 750 °C and 850 °C respectively, showing a low surface roughness of several nanometers. When annealed at 750 °C for 30 min, the saturated magnetization (Ms) and coercive field (Hc) of YIG films were 0.121 emu/mm{sup 3} (4πMs = 1.52 kGs) and 7 Oe respectively, which were similar to that prepared by PLD technique. The peak-to-peak linewidth of ferromagnetic resonance (FMR) was 220 Oe at 9.10 GHz. The results demonstrated that CSD was an excellent technique to prepare high quality yttrium iron garnet (YIG) films on silicon, which could provide a lower-cost way for large-scale production on Si-based integrated devices. - Highlights: • The preparation of YIG films by Chemical Solution Deposition are demonstrated. • Well-crystallized and crack-free YIG films can be obtained on Si substrate by CSD. • YIG films can be crystallized in 750 °C with good magnetic performances. • It's beneficial to large-scale production of YIG films on Si integrated devices.

  12. A comparison of partial order technique with three methods of multi-criteria analysis for ranking of chemical substances.

    Science.gov (United States)

    Lerche, Dorte; Brüggemann, Rainer; Sørensen, Peter; Carlsen, Lars; Nielsen, Ole John

    2002-01-01

    An alternative to the often cumbersome and time-consuming risk assessments of chemical substances could be more reliable and advanced priority setting methods. An elaboration of the simple scoring methods is provided by Hasse Diagram Technique (HDT) and/or Multi-Criteria Analysis (MCA). The present study provides an in depth evaluation of HDT relative to three MCA techniques. The new and main methodological step in the comparison is the use of probability concepts based on mathematical tools such as linear extensions of partially ordered sets and Monte Carlo simulations. A data set consisting of 12 High Production Volume Chemicals (HPVCs) is used for illustration. It is a paradigm in this investigation to claim that the need of external input (often subjective weightings of criteria) should be minimized and that the transparency should be maximized in any multicriteria prioritisation. The study illustrates that the Hasse diagram technique (HDT) needs least external input, is most transparent and is least subjective. However, HDT has some weaknesses if there are criteria which exclude each other. Then weighting is needed. Multi-Criteria Analysis (i.e. Utility Function approach, PROMETHEE and concordance analysis) can deal with such mutual exclusions because their formalisms to quantify preferences allow participation e.g. weighting of criteria. Consequently MCA include more subjectivity and loose transparency. The recommendation which arises from this study is that the first step in decision making is to run HDT and as the second step possibly is to run one of the MCA algorithms.

  13. [Aging Law of PAHs in Contaminated Soil and Their Enrichment in Earthworms Characterized by Chemical Extraction Techniques].

    Science.gov (United States)

    Zhang, Ya-nan; Yang, Xing-lun; Bian, Yong-rong; Gu, Cheng-gang; Liu, Zong-tang; Li, Jiao; Wang, Dai-zhang; Jiang, Xin

    2015-12-01

    To evaluate the effect of aging on the availability of PAHs, chemical extraction by exhaustive ( ASE extraction) and nonexhaustive techniques (Tenax-TA extraction, hydroxypropyl-p-cyclodextrin ( HPCD ) extraction, n-butyl alcohol ( BuOH) extraction) as well as PAHs accumulation in earthworms (Eisenia fetida) were conducted in yellow soil from Baguazhou, Nanjing, China, and red soil from Hainan, China, spiked with phenanthrene, pryene and benzo(a) pyrene and aged 0, 7, 15, 30 and 60 days. The results showed that the concentration of PAHs extracted by ASE and three nonexhaustive techniques and accumulated by earthworms significantly decreased with aging time, except the ASE extracted concentration between 30-and 60-day aging time. Furthermore, the relationships were studied in this experiment between chemical extracted PAHs concentration and accumulated concentration in earthworms. PAHs accumulated concentration in earthworms was not significantly correlated with the exhaustive extracted concentration of PAHs in soil (R² 0.44-0.56), which indicated that ASE extraction techniques could not predict PAHs bioavailability to earthworms because it overestimated the risk of PAHs. However, the PAHs accumulated concentration in earthworms was significantly correlated with the three nonexhaustive extracted concentrations of PAHs in soil, which indicated that all the three nonexhaustive techniques could predict PAHs bioavailability to earthworm to some extent, among which, HPCD extraction (R² 0.94-0.99) was better than Tenax-TA extraction (R² 0.62-0.87) and BuOH extraction (R² 0.69-0.94). So HPCD extraction was a more appropriate and reliable technique to predict bioavailability of PAHs in soil.

  14. Nuclear and radiochemical techniques in chemical analysis. Progress report, 1 June 1974--31 May 1975

    International Nuclear Information System (INIS)

    Finston, H.L.; Williams, E.T.

    1975-01-01

    Progress on the project to determine the neutron-absorption cross section of 22 Na is described. Upper limits for the thermal-neutron cross sections of 88 Y and 139 Ce have been set at 100 barns. The experiment to search for a change in the ratio of electron capture to positron emission due to difference in chemical environment is underway. The mechanical aspects of the system for analysis by proton-induced x-ray emission are described. Recent results on solvent extraction of mercury by pure solvents and propylene carbonate are described. Recent measurements in a study of an acid-base hypothesis are described. (U.S.)

  15. A study of essential elements in ancient Thai fighting swords by chemical and nuclear techniques

    International Nuclear Information System (INIS)

    Janposri, K.

    1980-01-01

    Four ancient Thai fighting swords from the Bangkok National Museum and iron ore from Kao Tab Kwai, Lopburi were studied by neutron activation analysis, metallography and chemical analysis. The results of these scientific studies show that all of these four swords are made of plain carbon steel, containing trace elements which have no effect on the physical and mechanical properties of the steel. The trace elements which were found in the iron ore are quite similar to those found in one of these swords. This means that the iron in one of the swords may have come from ore found at Kao Tab Kwai, Lopburi

  16. TPR system: a powerful technique to monitor carbon nanotube formation during chemical vapour deposition

    International Nuclear Information System (INIS)

    Tristao, Juliana Cristina; Moura, Flavia Cristina Camilo; Lago, Rochel Montero; Sapag, Karim

    2010-01-01

    In this work, a TPR (Temperature Programmed Reduction) system is used as a powerful tool to monitor carbon nanotubes production during CVD (Chemical Vapour Deposition), The experiments were carried out using catalyst precursors based on Fe-Mo supported on Al 2 O 3 and methane as carbon source. As methane reacts on the Fe metal surface, carbon is deposited and H2 is produced. TPR is very sensitive to the presence of H2 and affords information on the temperature where catalyst is active to form different forms of carbon, the reaction kinetics, the catalyst deactivation and carbon yields. (author)

  17. Moessbauer spectroscopy-nuclear hyperfine technique for studying dynamic chemical states of iron complexes

    International Nuclear Information System (INIS)

    Maeda, Y.

    2005-01-01

    A brief introduction of Moessbauer spectroscopy will be presented, followed by a discussion of the Moessbauer parameters, isomer shifts, quadrupole splittings, and spectral shapes of complexes in the presence of relaxation of the electronic states of the iron atoms. The usefulness of Moessbauer spectroscopy to demonstrate the dynamic phenomena of electronic states will be discussed in this lecture. (1) The Moessbauer spectra of mixed valence dinuclear and trinuclear iron complexes will be discussed in connection with the chemical structure of the complexes: The values of the quadrupole splittings and isomer shifts of [Fe II Fe III (bpmp) (ppa) 2 ](BF 4 ) 2 increase on raising the temperature, where Hbpmp represents 2,6-bis[bis(2- pyridylmethyl)aminoethyl]-4-methylphenol and ppa is 3-n-phenylpropionic acid. The spectra can be accounted for by postulating intramolecular electron exchange between two energetically inequivalent vibronic states Fe A 2+ Fe B 3+ and Fe A 3+ Fe B 2+ : The apparent time averaged valence states of the iron atoms are 2.2 and 2.8 on the Moessbauer time scale at 293 K. (2) The Moessbauer spectra of iron(III) spin-crossover complexes will be discussed in connection with the spin-transition rate and chemical structure of the complexes. The Moessbauer spectra of spin-crossover iron(III) complexes with LIESST (Light Induced Electronic Spin-State Transition) and of metallomesogens will be discussed to illustrate the extension of this research area by the use of Moessbauer spectroscopy.

  18. Chemical methods and techniques to monitor early Maillard reaction in milk products; A review.

    Science.gov (United States)

    Aalaei, Kataneh; Rayner, Marilyn; Sjöholm, Ingegerd

    2018-01-23

    Maillard reaction is an extensively studied, yet unresolved chemical reaction that occurs as a result of application of the heat and during the storage of foods. The formation of advanced glycation end products (AGEs) has been the focus of several investigations recently. These molecules which are formed at the advanced stage of the Maillard reaction, are suspected to be involved in autoimmune diseases in humans. Therefore, understanding to which extent this reaction occurs in foods, is of vital significance. Because of their composition, milk products are ideal media for this reaction, especially when application of heat and prolonged storage are considered. Thus, in this work several chemical approaches to monitor this reaction in an early stage are reviewed. This is mostly done regarding available lysine blockage which takes place in the very beginning of the reaction. The most popular methods and their applications to various products are reviewed. The methods including their modifications are described in detail and their findings are discussed. The present paper provides an insight into the history of the most frequently-used methods and provides an overview on the indicators of the Maillard reaction in the early stage with its focus on milk products and especially milk powders.

  19. Optimal parameters determination of the orbital weld technique using microstructural and chemical properties of welded joint

    International Nuclear Information System (INIS)

    Miranda, A.; Echevarria, J.F.; Rondon, S.; Leiva, P.; Sendoya, F.A.; Amalfi, J.; Lopez, M.; Dominguez, H.

    1999-01-01

    The paper deals with the study of the main parameters of thermal cycle in Orbital Automatic Weld, as a particular process of the GTAW Weld technique. Also is concerned with the investigation of microstructural and mechanical properties of welded joints made with Orbital Technique in SA 210 Steel, a particular alloy widely use during the construction of Economizers of Power Plants. A number of PC software were used in this sense in order to anticipate the main mechanical and structural characteristics of Weld metal and the Heat Affected Zone (HAZ). The papers also might be of great value during selection of optimal Weld parameters to produce sound and high quality Welds during the construction / assembling of structural components in high requirements industrial sectors and also to make a reliable prediction of weld properties

  20. Characterization of CuS nanocrystalline thin films synthesized by chemical bath deposition and dip coating techniques

    International Nuclear Information System (INIS)

    Chaki, Sunil H.; Deshpande, M.P.; Tailor, Jiten P.

    2014-01-01

    CuS thin films were synthesized by chemical bath deposition and dip coating techniques at ambient temperature. The energy dispersive analysis of X-rays of the thin films confirmed that both the as synthesized thin films are stoichiometric. The X-ray diffraction of the chemical bath deposited and dip coating deposited thin films showed that the films possess hexagonal structure having lattice parameters, a = b = 3.79 A and c = 16.34 A. The crystallite sizes determined from the X-ray diffraction data using Scherrer's formula for the chemical bath deposition and dip coating deposition thin films came out to be nearly 11 nm and 13 nm, respectively. The optical microscopy of the as deposited thin films surfaces showed that the substrates are well covered in both the deposited films. The scanning electron microscopy of the thin films clearly showed that in chemical bath deposited thin films the grain size varies from few μm to nm, while in dip coating deposited films the grain size ranges in nm. The optical bandgap determined from the optical absorbance spectrum analysis showed, chemical bath deposited thin films possess direct bandgap of 2.2 eV and indirect bandgap of 1.8 eV. In the case of dip coating deposited thin films, the direct bandgap is 2.5 eV and indirect bandgap is 1.9 eV. The d.c. electrical resistivity variation with temperature for both the deposited films showed that the resistivity decreases with temperature thus confirming the semiconducting nature. The thermoelectric power variations with temperature and the room temperature Hall Effect study of both the synthesized CuS thin films showed them to be of p-type conductivity. The obtained results are discussed in details. - Highlights: • CuS thin films were synthesized by chemical bath deposition and dip coating techniques. • The films possessed hexagonal structure. • The optical absorption showed that the films had direct and indirect bandgap. • Study of electrical transport properties

  1. Stimulation and inhibition of bacterial growth by caffeine dependent on chloramphenicol and a phenolic uncoupler--a ternary toxicity study using microfluid segment technique.

    Science.gov (United States)

    Cao, Jialan; Kürsten, Dana; Schneider, Steffen; Köhler, J Michael

    2012-10-01

    A droplet-based microfluidic technique for the fast generation of three dimensional concentration spaces within nanoliter segments was introduced. The technique was applied for the evaluation of the effect of two selected antibiotic substances on the toxicity and activation of bacterial growth by caffeine. Therefore a three-dimensional concentration space was completely addressed by generating large sequences with about 1150 well separated microdroplets containing 216 different combinations of concentrations. To evaluate the toxicity of the ternary mixtures a time-resolved miniaturized optical double endpoint detection unit using a microflow-through fluorimeter and a two channel microflow-through photometer was used for the simultaneous analysis of changes on the endogenous cellular fluorescence signal and on the cell density of E. coli cultivated inside 500 nL microfluid segments. Both endpoints supplied similar results for the dose related cellular response. Strong non-linear combination effects, concentration dependent stimulation and the formation of activity summits on bolographic maps were determined. The results reflect a complex response of growing bacterial cultures in dependence on the combined effectors. A strong caffeine induced enhancement of bacterial growth was found at sublethal chloramphenicol and sublethal 2,4-dinitrophenol concentrations. The reliability of the method was proved by a high redundancy of fluidic experiments. The results indicate the importance of multi-parameter investigations for toxicological studies and prove the potential of the microsegmented flow technique for such requirements.

  2. Elemental chemical characterization of coins of currently national circulating by X-ray fluorescence non-destructive techniques

    International Nuclear Information System (INIS)

    Olivera, Paula; Calcina, Esly

    2013-01-01

    Given the frequent counterfeit bills and coins is proposed in this paper to identify the elemental chemical composition; for now, the current official currencies circulating in our country, by Energy Dispersive X-ray Fluorescence technique and non-destructive methods, the goal is to compare with the false and establish the differences that could help identify them immediately taking advantage of the fast response of this technique. Have been identified the elements Al in the coins of 5 cents, Cu and Zn for 10 and 20 cents, Ni, Cu and Zn for 50 cents and a Un Nuevo Sol and Cr, Cu and Zn 2 coins 5 Nuevos Soles. 57 Peruvian coins of different production years and a counterfeit coin of 5 Nuevos Soles have been analyzed, finding Cu and Zn in central part and Fe in circulating edge ring, looking for this one the absence of Ni and Cr, which in the official currency was found. (authors).

  3. Nuclear and radiochemical techniques in chemical analysis. Progress report, June 1, 1975--July 31, 1976

    International Nuclear Information System (INIS)

    Finston, H.L.; Williams, E.T.

    1976-01-01

    There has been significant progress on the project to measure the neutron-capture cross sections of reactor produced radionuclides, in particular, centering on the problems with nuclides such as 22 Na which may have a resonance for thermal-neutron capture. The thermal capture cross section of less than 40 b has been verified for 54 Mn, and cadmium ratios have been determined for 184 Re in the V-11 and V-14 positions in the HFBR. Lutetium has been used as a neutron temperature monitor for the Brookhaven reactors. Preliminary results on the project to determine the effect of chemical state on the branching ratio in 58 Co are reported. Procedures for aerosol collection and analysis by proton-induced x-ray emission (PIXE) are reported. A program to analyze aerosols for polycyclic aromatic hydrocarbons has been initiated. Progress is reported on the experimental verification of the proposed acid-base hypothesis

  4. Chemical intermediate detection following corona discharge on volatile organic compounds: general method using molecular beam techniques

    International Nuclear Information System (INIS)

    He Luning; Sulkes, Mark

    2011-01-01

    Nonthermal plasma (NTP)-based treatments of volatile organic compounds (VOCs) have potential for effective environmental remediation. Theory and experiment that consider the basic science pertaining to discharge events have helped improve NTP remediation outcomes. If direct information on early post-discharge chemical intermediates were also available, it would likely lead to additional improvement in NTP remediation outcomes. To this point, however, experiments yielding direct information on post-NTP VOC intermediates have been limited. An approach using supersonic expansion molecular beam methods offers general promise for detection of post-discharge VOC intermediates. To illustrate the potential utility of these methods, we present mass spectra showing the growth of early products formed when pulsed corona discharges were carried out on toluene in He and then in He with added O 2 . Good general detection of neutral post-discharge species was obtained using 800 nm 150 fs photoionization pulses.

  5. A Study on an Executive Technique and Activation of Clean Production in Chemical Industry

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Seong Yong; Lee, Hee Seok; Kim, Kang Seok [Korea Environment Institute, Seoul (Korea)

    2000-12-01

    Clean production does not only make the sustainable development possible through preventing the deterioration of the environmental pollution from the expansion of industrialization but also enhance the company's competitiveness. Clean production is required by all industrial fields but is the most important in chemical industry. The Government has made efforts to change the domestic industrial structure to the environmental-friendly structure through developing the research. However, the domestic industry has not yet activated overall except some large companies, which has concretized the activation of clean production. Especially, the medium and small companies are more sluggish due to the inferiority of capital and technology. With recognizing that the main body of clean production is a company, the effort based on the Government and the academic world, without companies' positive, will cannot help being limited in effects. Therefore, it is necessary to trigger the schemes that urge the companies' motivation to show the effects from the support that have concentrated in hardware like technology until now. It seems to be very important that the guidebook for clean production, which a company can easily adopt, is developed and spread. This report provides the guidebook for clean production that managers and engineers can easily understand and approach in a producing field and presents the scheme to promote clean production, for chemical industry that is seriously required clean production. Even if the presented contents are not perfect, they can be applied to the development of the Government's policy and the administrative activities of companies for clean production as a useful data. 53 refs., 5 figs., 30 tabs.

  6. From Technique of Tattooing to Biokinetics and Toxicology of Injected Tattoo Ink Particles and Chemicals.

    Science.gov (United States)

    Serup, Jørgen

    2017-01-01

    Tattoo colourants are colourful nano- and microparticles, which are practically insoluble and thus permanent once installed in the dermis by the tattooist. Tattoo ink also has soluble ingredients and contaminants. Pigments can distribute via the lymph and possibly also directly to the blood, and a minute fraction may over time undergo metabolic breakdown and as hapten(s) induce allergic reactions of red tattoos. Carbon black of black tattoos has a tendency to agglomerate and form larger bodies that can elicit foreign body reactions in black tattoos and even granuloma formation with overlap to sarcoidosis in the clinic. Very little is known about the biokinetics and safety profile of the many tattoo pigments in use, and no specific pigment-related chemical of tattoo ink causing identified adverse reactions in humans has been depicted. Inks have many ingredients and contaminants. Insoluble and soluble ingredients of inks supposedly have very different characteristics of absorption, distribution, metabolism, and excretion, with pigments being extremely slowly excreted, contrasting soluble ingredients with fast elimination. Tattoos are a single-dose exposure. Controlling the safety of tattoo inks by banning potentially critical chemicals hitherto has been unsuccessful due to lacking documentation of clinical and epidemiological relevance and because the tattoo industry is already internationally established, free, and in the ownership of the people. Doctors treating patients with tattoo complications consequently have a key role in identifying risk situations and local outbreaks, which needs clarification, therapy, and the intervention of authorities. In the treatment of complications, as seen in general practice and in other specialties, basic insight into the fate of tattoo pigments in the body is necessary. Tattoo complications are complicated and facetted with many entities and disease mechanisms; they are a new subspecialty in medicine and dermatology. © 2017 S

  7. Radioactive tracer technique in process optimization: applications in the chemical industry

    International Nuclear Information System (INIS)

    Charlton, J.S.

    1989-01-01

    Process optimization is concerned with the selection of the most appropriate technological design of the process and with controlling its operation to obtain maximum benefit. The role of radioactive tracers in process optimization is discussed and the various circumstances under which such techniques may be beneficially applied are identified. Case studies are presented which illustrate how radioisotopes may be used to monitor plant performance under dynamic conditions to improve production efficiency and to investigate the cause of production limitations. In addition, the use of sealed sources to provide information complementary to the tracer study is described. (author)

  8. Norepinephrine stimulates progesterone production in highly estrogenic bovine granulosa cells cultured under serum-free, chemically defined conditions

    Directory of Open Access Journals (Sweden)

    Piccinato Carla A

    2012-11-01

    Full Text Available Abstract Background Since noradrenergic innervation was described in the ovarian follicle, the actions of the intraovarian catecholaminergic system have been the focus of a variety of studies. We aimed to determine the gonadotropin-independent effects of the catecholamine norepinephrine (NE in the steroid hormone profile of a serum-free granulosa cell (GC culture system in the context of follicular development and dominance. Methods Primary bovine GCs were cultivated in a serum-free, chemically defined culture system supplemented with 0.1% polyvinyl alcohol. The culture features were assessed by hormone measurements and ultrastructural characteristics of GCs. Results GCs produced increasing amounts of estradiol and pregnenolone for 144h and maintained ultrastructural features of healthy steroidogenic cells. Progesterone production was also detected, although it significantly increased only after 96h of culture. There was a highly significant positive correlation between estradiol and pregnenolone production in high E2-producing cultures. The effects of NE were further evaluated in a dose–response study. The highest tested concentration of NE (10 (−7 M resulted in a significant increase in progesterone production, but not in estradiol or pregnenolone production. The specificity of NE effects on progesterone productio n was further investigated by incubating GCs with propranolol (10 (−8 M, a non-selective beta-adrenergic antagonist. Conclusions The present culture system represents a robust model to study the impact of intrafollicular factors, such as catecholamines, in ovarian steroidogenesis and follicular development. The results of noradrenergic effects in the steroidogenesis of GC have implications on physiological follicular fate and on certain pathological ovarian conditions such as cyst formation and anovulation.

  9. Norepinephrine stimulates progesterone production in highly estrogenic bovine granulosa cells cultured under serum-free, chemically defined conditions.

    Science.gov (United States)

    Piccinato, Carla A; Montrezor, Luis H; Collares, Cristhianna A V; Vireque, Alessandra A; Rosa e Silva, Alzira A M

    2012-11-22

    Since noradrenergic innervation was described in the ovarian follicle, the actions of the intraovarian catecholaminergic system have been the focus of a variety of studies. We aimed to determine the gonadotropin-independent effects of the catecholamine norepinephrine (NE) in the steroid hormone profile of a serum-free granulosa cell (GC) culture system in the context of follicular development and dominance. Primary bovine GCs were cultivated in a serum-free, chemically defined culture system supplemented with 0.1% polyvinyl alcohol. The culture features were assessed by hormone measurements and ultrastructural characteristics of GCs. GCs produced increasing amounts of estradiol and pregnenolone for 144h and maintained ultrastructural features of healthy steroidogenic cells. Progesterone production was also detected, although it significantly increased only after 96h of culture. There was a highly significant positive correlation between estradiol and pregnenolone production in high E2-producing cultures. The effects of NE were further evaluated in a dose-response study. The highest tested concentration of NE (10 (-7) M) resulted in a significant increase in progesterone production, but not in estradiol or pregnenolone production. The specificity of NE effects on progesterone production was further investigated by incubating GCs with propranolol (10 (-8) M), a non-selective beta-adrenergic antagonist. The present culture system represents a robust model to study the impact of intrafollicular factors, such as catecholamines, in ovarian steroidogenesis and follicular development. The results of noradrenergic effects in the steroidogenesis of GC have implications on physiological follicular fate and on certain pathological ovarian conditions such as cyst formation and anovulation.

  10. Development of method to chemical separation of gallium-67 by thermal diffusion technique

    International Nuclear Information System (INIS)

    Martins, Patricia de Andrade

    2012-01-01

    Radioisotopes of gallium have been studied and evaluated for medical applications since 1949. Over the past 50 years 67 Ga has been widely used in the diagnosis of various diseases, including acute and chronic inflammatory lesions, bacterial or sterile and several types of tumors. In Brazil 30% of clinics that provide services for Nuclear Medicine use 67 Ga citrate and the demand for 67 G a at IPEN-CNEN/SP is 37 GBq (1 Ci)/week. The 67 Ga presents physical half-life of 3.26 days (78 hours) and decays 100% by electron capture to stable 67 Zn. Its decay includes the emission of γ rays with energies of 93.3 keV (37%), 184.6 keV (20.4%), 300.2 keV (16.6%) and 888 keV (26%). In the past 67 Ga was produced by the reaction 68 Zn (p, 2n) 67 Ga at IPEN-CNEN/SP. After irradiation, the target was dissolved in concentrated HCl and the solution percolated through a cationic resin DOWEX 50W-X8, 200-400 mesh, conditioned with 10 mol L -1 HCl. Zinc, nickel and copper were eluted in 10 mol L -1 HCl and 67 Ga 3.5 mol L -1 HCl. The final product was obtained as 67 Ga citrate. This work presents a new, fast, direct and efficient method for the chemical separation of 67 G a by thermal diffusion (heating of the target) combined with concentrated acetic acid extraction. Purification was performed by ion exchange chromatography. Natural zinc electrodeposition was performed on nickel/copper plates as substrate and the zinc deposits were adherent to the substrate, slightly shiny and uniform. The targets were irradiated with 26 MeV protons and integrated current of 10 μA.h. After irradiation, the targets were heated at 300 deg C for 2 hours and placed in contact with concentrated acetic acid for 1 hour. The average yield of extraction of 67 Ga was (72 ± 10)%. This solution was evaporated and the residue was taken up in 0.5 mol L -1 NH 4 OH. The 67 G a was purified on cationic resin Dowex 50WX8 in NH 4 OH medium. The 67 Ga recovery was (98 ± 2)%. This solution was evaporated and taken up

  11. Construction of a technique plan repository and evaluation system based on AHP group decision-making for emergency treatment and disposal in chemical pollution accidents

    International Nuclear Information System (INIS)

    Shi, Shenggang; Cao, Jingcan; Feng, Li; Liang, Wenyan; Zhang, Liqiu

    2014-01-01

    Highlights: • Different chemical pollution accidents were simplified using the event tree analysis. • Emergency disposal technique plan repository of chemicals accidents was constructed. • The technique evaluation index system of chemicals accidents disposal was developed. • A combination of group decision and analytical hierarchy process (AHP) was employed. • Group decision introducing similarity and diversity factor was used for data analysis. - Abstract: The environmental pollution resulting from chemical accidents has caused increasingly serious concerns. Therefore, it is very important to be able to determine in advance the appropriate emergency treatment and disposal technology for different types of chemical accidents. However, the formulation of an emergency plan for chemical pollution accidents is considerably difficult due to the substantial uncertainty and complexity of such accidents. This paper explains how the event tree method was used to create 54 different scenarios for chemical pollution accidents, based on the polluted medium, dangerous characteristics and properties of chemicals involved. For each type of chemical accident, feasible emergency treatment and disposal technology schemes were established, considering the areas of pollution source control, pollutant non-proliferation, contaminant elimination and waste disposal. Meanwhile, in order to obtain the optimum emergency disposal technology schemes as soon as the chemical pollution accident occurs from the plan repository, the technique evaluation index system was developed based on group decision-improved analytical hierarchy process (AHP), and has been tested by using a sudden aniline pollution accident that occurred in a river in December 2012

  12. Construction of a technique plan repository and evaluation system based on AHP group decision-making for emergency treatment and disposal in chemical pollution accidents

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Shenggang [College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083 (China); College of Chemistry, Baotou Teachers’ College, Baotou 014030 (China); Cao, Jingcan; Feng, Li; Liang, Wenyan [College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083 (China); Zhang, Liqiu, E-mail: zhangliqiu@163.com [College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083 (China)

    2014-07-15

    Highlights: • Different chemical pollution accidents were simplified using the event tree analysis. • Emergency disposal technique plan repository of chemicals accidents was constructed. • The technique evaluation index system of chemicals accidents disposal was developed. • A combination of group decision and analytical hierarchy process (AHP) was employed. • Group decision introducing similarity and diversity factor was used for data analysis. - Abstract: The environmental pollution resulting from chemical accidents has caused increasingly serious concerns. Therefore, it is very important to be able to determine in advance the appropriate emergency treatment and disposal technology for different types of chemical accidents. However, the formulation of an emergency plan for chemical pollution accidents is considerably difficult due to the substantial uncertainty and complexity of such accidents. This paper explains how the event tree method was used to create 54 different scenarios for chemical pollution accidents, based on the polluted medium, dangerous characteristics and properties of chemicals involved. For each type of chemical accident, feasible emergency treatment and disposal technology schemes were established, considering the areas of pollution source control, pollutant non-proliferation, contaminant elimination and waste disposal. Meanwhile, in order to obtain the optimum emergency disposal technology schemes as soon as the chemical pollution accident occurs from the plan repository, the technique evaluation index system was developed based on group decision-improved analytical hierarchy process (AHP), and has been tested by using a sudden aniline pollution accident that occurred in a river in December 2012.

  13. Comparison of results analysis of chemical composition of alloys inside the U-Zr-Nb by XRF and AAS techniques

    International Nuclear Information System (INIS)

    Masrukan; Tri Yulianto; Anwar Muchsin

    2011-01-01

    U-Zr-Nb alloy chemical composition analysis using X Ray Fluorescence (XRF) and Atomic Absorption Spectroscopy (AAS) techniques have been conducted, where U-Zr- Nb alloy was chosen as candidates for new high-density fuel for future research reactors . Composition analysis is necessary because the composition of elements in the fuel will determine the characteristics of fuel during the fabrication process and in the reactor. The use of two kinds of analysis techniques were designed to obtain accurate analysis results. The experiment was conducted to determine the major element composition and impurities in the alloy U-Zr-Nb. First U-Zr-Nb varying alloy composition Nb were respectively 1%, 4%, 7% (U10% Zr1% Nb, U10% Zr4% Nb and U10% 7% Nb) as results of the melting process of measuring the diameter of 120 mm crushed on the surface bottom. Once on the bottom surface is smooth, then analyzed using XRF techniques. To analyze the elements using AAS techniques, alloy U-Zr-Nb cut into 10 mm x 5 mm then dissolved using HF and nitric acid. Solution that occurred were analyzed using AAS technique. From the analysis using the XRF technique is obtained the alloy U-10% Zr-1% Nb, U-10% Zr-4% Nb and Zr-10% U-7% Nb) had a content of each element as follows: U (87.8858%), Zr (2.6097%) and Nb (0.2206%), U (87.8556%), Zr (2.6302%), and Nb (0.6573%); U (84.6334%), Zr (2.5773%), and Nb (1.0940) weight. Results of analysis using AAS techniques on samples obtained third consecutive Zr content of 9.25%, 8.90% and 9.80% while the content of Nb was not detected. Meanwhile, the results of elemental analysis of impurities in all three samples showed that almost all the elements are still qualify as fuel except Zn element. Element Zn at the three samples of each alloys U-10% Zr-1% Nb, U-10% Zr-4% Nb and U-10% Zr-7%Nb is 1.3266%, 3.2756% and 1.0927% weight. It could be concluded that the results of analysis of elemental content and impurities in the alloy U-Nb-Zr using both XRF and AAS visible

  14. Molecular structure and spectroscopic characterization of Carbamazepine with experimental techniques and DFT quantum chemical calculations

    Science.gov (United States)

    Suhasini, M.; Sailatha, E.; Gunasekaran, S.; Ramkumaar, G. R.

    2015-04-01

    A systematic vibrational spectroscopic assignment and analysis of Carbamazepine has been carried out by using FT-IR, FT-Raman and UV spectral data. The vibrational analysis were aided by electronic structure calculations - ab initio (RHF) and hybrid density functional methods (B3LYP) performed with standard basis set 6-31G(d,p). Molecular equilibrium geometries, electronic energies, natural bond order analysis, harmonic vibrational frequencies and IR intensities have been computed. A detailed interpretation of the vibrational spectra of the molecule has been made on the basis of the calculated Potential Energy Distribution (PED) by VEDA program. UV-visible spectrum of the compound was also recorded and the electronic properties, such as HOMO and LUMO energies and λmax were determined by HF/6-311++G(d,p) Time-Dependent method. The thermodynamic functions of the title molecule were also performed using the RHF and DFT methods. The restricted Hartree-Fock and density functional theory-based nuclear magnetic resonance (NMR) calculation procedure was also performed, and it was used for assigning the 13C and 1H NMR chemical shifts of Carbamazepine.

  15. A physico-chemical characterisation technique for determining the pore-water chemistry in argillaceous rocks

    International Nuclear Information System (INIS)

    Baeyens, B.; Bradbury, M.H.

    1991-09-01

    A prerequisite for carrying out credible sorption studies is the definition of an aqueous phase composition which is in equilibrium with the solid phase. Experimental methods and data analysis procedures are described which enable an equilibrium water composition to be produced for argillaceous rocks which is not dependent on liquid to solid (L:S) ratios. Since a Valanginian marl formation is under consideration by Nagra as a potential rock for the disposal of low and short-lived medium level radioactive waste in Switzerland, samples of this material were chosen for this investigation. Aqueous phase and nickel ethylenediamine extraction experiments were carried out at different L:S ratios under controlled atmosphere conditions (P CO 2 =10 -2 bar, O 2 ≤ 5 ppm ). The results from these tests and petrographical examinations were combined to define the system in terms of the physico-chemical characteristics of the clay mineral component (CEC and cation occupancies) and the identities of highly soluble and solubility limited phases in the marl. The geochemical code PHREEQE was used in conjunction with the Gapon equations to calculate the pore water composition. This work clearly showed that pore water chemistries obtained from aqueous extracts alone may lead to an arbitrary water chemistry in argillaceous rock systems, particularly with respect to ionic composition and ionic strength, which may have important consequences for radionuclide speciation and sorption studies. (author) 11 figs., 12 tabs., 25 refs

  16. Equatorial F region neutral winds and shears near sunset measured with chemical release techniques

    Science.gov (United States)

    Kiene, A.; Larsen, M. F.; Kudeki, E.

    2015-10-01

    The period near sunset is a dynamic and critical time for the daily development of the equatorial nighttime ionosphere and the instabilities that occur there. It is during these hours that the preconditions necessary for the later development of Equatorial Spread F (ESF) plasma instabilities occur. The neutral dynamics of the sunset ionosphere are also of critical importance to the generation of currents and electric fields; however, the behavior of the neutrals is experimentally understood primarily through very limited single-altitude measurements or measurements that provide weighted altitude means of the winds as a function of time. To date, there have been very few vertically resolved neutral wind measurements in the F region at sunset. We present two sets of sounding rocket chemical release measurements, one from a launch in the Marshall Islands on Kwajalein atoll and one from Alcantara, Brazil. Analysis of the release motions has yielded vertically resolved neutral wind profiles that show both the mean horizontal winds and the vertical shears in the winds. In both experiments, we observe significant vertical gradients in the zonal wind that are unexpected by classical assumptions about the behavior of the neutral wind at these altitudes at sunset near the geomagnetic equator.

  17. Nuclear and radiochemical techniques in chemical analysis. Progress report, August 1, 1977--July 31, 1978

    International Nuclear Information System (INIS)

    Finston, H.L.; Williams, E.T.

    1978-07-01

    The study of neutron-absorption cross sections of reactor-produced radionuclides has been completed, and results are reported for 22 Na, 126 I, 139 Ce, 88 Y, 184 Re, 182 Ta, 54 Mn, and 94 Zr. The results for 22 Na indicate the existence of a resonance in the thermal region which could explain the discrepancies in the published values for the thermal cross section. The results of air-sampling experiments are described as is the proton-induced x-ray emission system developed at Brooklyn College. Work on sample preparation and applications of the PIXE technique are given. Progress on a nuclear method to determine fluorine-containing gaseous compounds is reported. Work on solvent extraction with propylene carbonate and experiments involving an acid-base hypothesis are described

  18. Irradiation of dates: insect disinfestation, microbial and chemical assessments, and use of thermoluminescence technique

    Energy Technology Data Exchange (ETDEWEB)

    Al-Kahtani, Hassan A.; Abu-Tarboush, Hamza M.; Ahmed, Mohamed A.; Bajaber, Adnan S. [Food Science and Nutrition Department, College of Agriculture, King Saud University, Riyadh (Saudi Arabia); Al-Dryhim, Yousif N.; Adam, El-Shami E. [Plant Protection Department, College of Agriculture, King Saud University, Riyadh (Saudi Arabia); El-Mojaddidi, Mohamed A. [King Faisal Specialist Hospital and Research Center, Riyadh (Saudi Arabia)

    1998-08-01

    Irradiation of dates (Khalas variety) at 0.9 kGy was sufficient to eliminate single insect infestation (Oryzaephilus surinamensis) and mixed infestation (O. surinamensis and Tribolium castaneum), whereas 0.3 kGy was effective only in controlling single infestation. Sensory properties were not affected but irradiation contributed to some reduction in microbial counts immediately after irradiation and counts remained low till the end of 6 months storage period. All sugars were significantly reduced immediately after irradiation but they increased gradually with increasing storage time. Thermoluminescence (TL) technique was useful in discriminating between irradiated and unirradiated dates during the entire storage period but was less sensitive as far as the dose estimation is concerned.

  19. Irradiation of dates: insect disinfestation, microbial and chemical assessments, and use of thermoluminescence technique

    International Nuclear Information System (INIS)

    Al-Kahtani, Hassan A.; Abu-Tarboush, Hamza M.; Ahmed, Mohamed A.; Bajaber, Adnan S.; Al-Dryhim, Yousif N.; Adam, El-Shami E.; El-Mojaddidi, Mohamed A.

    1998-01-01

    Irradiation of dates (Khalas variety) at 0.9 kGy was sufficient to eliminate single insect infestation (Oryzaephilus surinamensis) and mixed infestation (O. surinamensis and Tribolium castaneum), whereas 0.3 kGy was effective only in controlling single infestation. Sensory properties were not affected but irradiation contributed to some reduction in microbial counts immediately after irradiation and counts remained low till the end of 6 months storage period. All sugars were significantly reduced immediately after irradiation but they increased gradually with increasing storage time. Thermoluminescence (TL) technique was useful in discriminating between irradiated and unirradiated dates during the entire storage period but was less sensitive as far as the dose estimation is concerned

  20. Nuclear and radiochemical techniques in chemical analysis. Progress report, August 1, 1978-July 31, 1979

    International Nuclear Information System (INIS)

    Finston, H.L.; Williams, E.T.

    1979-07-01

    Studies of homogeneous liquid-liquid extraction have been extended to include (1) a detailed determination of the phase diagram of the system propylene carbonate-water, (2) the extraction of a large variety of both monodentate and bidentate iron complexes, (3) the solvent extraction characteristics of analogues of propylene carbonate, (4) the behavior under pressure of the propylene carbonate water system, and (5) the extraction behavior of alkaline earth - TTA chelates. One consequence of these studies was the observation that the addition of ethanol to propylene carbonate-water or to isobutylene carbonate-water yields a single homogeneous phase. Subsequent evaporation of the ethanol restores the two immiscible phases. Past neutron activation analysis has been attempted for the heavy elements Pb, Bi, Tl at the Brookhaven HFBR (in- or near-core position) and at the Brookhaven CLIF facility. The latter appears more promising and we have initiated a collaborative program to use the CLIF facility. A milking system which can provide ca. 16 μCi of carrier-free 212 Pb was developed for use in an isotope dilution technique for lead. Collaboration with laboratories already determining trace lead by flameless Atomic Absorption or by concentration by electrodeposition into a hanging drop followed by Anodic stripping will be proposed. The Proton X-Ray Emission system has undergone marked improvement with the acquisition of a new high resolution Si(Li) detector and a new multi-channel analyzer system. Various techniques have been explored to dissolve and prepare samples for PIXE analysis and also for verification by Atomic Absorption analysis

  1. Nuclear and radiochemical techniques in chemical analysis. Progress report, August 1, 1978-July 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Finston, H. L.; Williams, E. T.

    1979-07-01

    Studies of homogeneous liquid-liquid extraction have been extended to include (1) a detailed determination of the phase diagram of the system propylene carbonate-water, (2) the extraction of a large variety of both monodentate and bidentate iron complexes, (3) the solvent extraction characteristics of analogues of propylene carbonate, (4) the behavior under pressure of the propylene carbonate water system, and (5) the extraction behavior of alkaline earth - TTA chelates. One consequence of these studies was the observation that the addition of ethanol to propylene carbonate-water or to isobutylene carbonate-water yields a single homogeneous phase. Subsequent evaporation of the ethanol restores the two immiscible phases. Past neutron activation analysis has been attempted for the heavy elements Pb, Bi, Tl at the Brookhaven HFBR (in- or near-core position) and at the Brookhaven CLIF facility. The latter appears more promising and we have initiated a collaborative program to use the CLIF facility. A milking system which can provide ca. 16 ..mu..Ci of carrier-free /sup 212/Pb was developed for use in an isotope dilution technique for lead. Collaboration with laboratories already determining trace lead by flameless Atomic Absorption or by concentration by electrodeposition into a hanging drop followed by Anodic stripping will be proposed. The Proton X-Ray Emission system has undergone marked improvement with the acquisition of a new high resolution Si(Li) detector and a new multi-channel analyzer system. Various techniques have been explored to dissolve and prepare samples for PIXE analysis and also for verification by Atomic Absorption analysis.

  2. Experimental setup for producing tungsten coated graphite tiles using plasma enhanced chemical vapor deposition technique for fusion plasma applications

    International Nuclear Information System (INIS)

    Chauhan, Sachin Singh; Sharma, Uttam; Choudhary, K.K.; Sanyasi, A.K.; Ghosh, J.; Sharma, Jayshree

    2013-01-01

    Plasma wall interaction (PWI) in fusion grade machines puts stringent demands on the choice of materials in terms of high heat load handling capabilities and low sputtering yields. Choice of suitable material still remains a challenge and open topic of research for the PWI community. Carbon fibre composites (CFC), Beryllium (Be), and Tungsten (W) are now being considered as first runners for the first wall components of future fusion machines. Tungsten is considered to be one of the suitable materials for the job because of its superior properties than carbon like low physical sputtering yield and high sputter energy threshold, high melting point, fairly high re-crystallization temperature, low fuel retention capabilities, low chemical sputtering with hydrogen and its isotopes and most importantly the reparability with various plasma techniques both ex-situ and in-situ. Plasma assisted chemical vapour deposition is considered among various techniques as the most preferable technique for fabricating tungsten coated graphite tiles to be used as tokamak first wall and target components. These coated tiles are more favourable compared to pure tungsten due to their light weight and easier machining. A system has been designed, fabricated and installed at SVITS, Indore for producing tungsten coated graphite tiles using Plasma Enhanced Chemical Vapor Deposition (PE-CVD) technique for Fusion plasma applications. The system contains a vacuum chamber, a turbo-molecular pump, two electrodes, vacuum gauges, mass analyzer, mass flow controllers and a RF power supply for producing the plasma using hydrogen gas. The graphite tiles will be put on one of the electrodes and WF6 gas will be inserted in a controlled manner in the hydrogen plasma to achieve the tungsten-coating with WF6 dissociation. The system is integrated at SVITS, Indore and a vacuum of the order of 3*10 -6 is achieved and glow discharge plasma has been created to test all the sub-systems. The system design with

  3. Recycling of wastes from fish beneficiation by composting: chemical characteristics of the compost and efficiency of their humic acids in stimulating the growth of lettuce.

    Science.gov (United States)

    Busato, Jader Galba; de Carvalho, Caroline Moreira; Zandonadi, Daniel Basilio; Sodré, Fernando Fabriz; Mol, Alan Ribeiro; de Oliveira, Aline Lima; Navarro, Rodrigo Diana

    2017-11-23

    Waste from the beneficiation of fish was composted with crushed grass aiming to characterize their chemical composition and investigate the possibility of the use of the final compost as source of humic acids (HA) able to stimulate the growth of lettuce. Compost presented pH value, C/N ratio, and electrical conductivity that allow its use as an organic fertilizer. The element content was present in the following order of abundance in the compost: P > Ca > N > Mg > K > Fe > Zn > Mn > Mo > Cu, and the humus composition was similar to that observed in others kind of organic residues composted. The high content of oxygen pointed out a high level of oxidation of HA, in line with the predominance of phenolic acidity in the functional groups. The 13 C-NMR spectra showed marked resonances due to the presence of lipids and other materials resistant to degradation as methoxy substituent and N-alkyl groups. A concentration of 20 mg L -1 HA increased significantly both dry and wet root matter in lettuce but the CO 2 assimilation, stomatal conductance, and number of lateral roots of the plants were not affected. However, increases of 64% in the water-use efficiency was observed due to the HA addition, probably related to the root morphology alteration which resulted in 1.6-fold increase of lateral root average length and due to the higher H + extrusion activity. Reuse of residues from the fish beneficiation activity by composting may represent a safe tool to increase the value of recycled organic residues and generate HA with potential use as plant growth stimulants.

  4. Low-impact chemical weed control techniques in UNESCO World Heritage Sites of Cuba.

    Science.gov (United States)

    Hernandez-Enriquez, O; Alvarez, R; Morelli, F; Bastida, F; Camacho, D; Menendez, J

    2012-01-01

    Dichrostachys cinerea is a thorny, acacia-like, fast-growing woody bush which invades fields, wasteland, road sides and other disturbed areas. This gregarious species has become a very aggressive invasive weed in Cuba, where no native predators or pathogens are found. It often encroaches in fallows, overgrazed areas and mismanaged veld. D. cinerea is a very difficult weed to eliminate because of its active suckering, and is liable to produce dense thickets which are quite impenetrable on account of the density and abundance of its long, stiff, sharp thorns. In the Valle de los Ingenios area (Cuba Central), the tree is unchecked and forms veritable forests in areas on which cane growing has been discontinued. Physical management by cutting and burning the plants is not a very efficient control method, since the seeds survive in the soil, and they grow very fast. Therefore, chemical methods via the use of herbicides are often necessary to eradicate this weed. A preliminary study using glyphosate and auxin-like herbicides (2,4-D + picloram, MCPA, and MCPA + 2,4-D) plus adjuvants has been carried out in order to elucidate the best mixtures rendering maximum weed control with minimum herbicide rate and environmental stress. None of the herbicides used except glyphosate and 2,4-D + picloram showed acceptable mortality rates (75-80%) at the recommended doses tested. In the failed herbicide treatments, only the use of double herbicide rates succeeded in controlling marabou. The herbicide mixture of 2,4-D + picloram formulated with either a non-ionic surfactant or a mixture of fatty acid esters was the best option to control D. cinerea in terms of maximum effectiveness and minimum environmental stress, as the reduction in active ingredients applied to the environment was x3 in these two adjuvant-amended formulations compared to 2,4-D + picloram alone.

  5. Comparison of the incidence of intracranial hemorrhage in two different planning techniques for stereotactic electrode placement in the deep brain stimulation.

    Science.gov (United States)

    Piacentino, M; Zambon, G; Pilleri, M; Bartolomei, L

    2013-03-01

    Intracranial hemorrhage is an infrequent but potentially devastating complication associated with the placement of electrodes for deep brain stimulation (DBS). The objective of this retrospective review is to compare the risk of hemorrhage before and after the introduction of image-guided neuronavigation for the implant of electrodes for DBS. We reviewed all DBS implant performed at our Institute between 1998 and 2010. In 63 of the 106 patients, the targeting was based on ventriculography and merge of CT/MRI. After 2006, in the latter 43 procedures, we introduced targeting based on the merging of angio CT and MRI.. In both implant techniques, microelectrode recording (MER) was used to better define the target. All DBS procedures were performed by a single surgeon (M.P.). Patients had postoperative imaging (MRI or CT) 4-24 h following surgery. In the group of patients implanted with the first targeting technique, 3 hematomas occurred and all of them solved with sequelae (one residual weakness and two hemiplegias.) After the introduction of neuronavigator, 2 hemorrhages occurred, one solved without sequelae while the second resulted in epileptic seizures. Although the incidence of hemorrhage occurred before and after the use of neuronavigation is the same, the severity is lower in the neuronavigated procedures. Targeting based on the merging of CT angiography and MRI T1/T2 seemed to increase the safety of the lead placement reducing the risk of sequelae related to bleeding. The use of MER was not found to be correlated with an increased hemorrhage rate.

  6. A multi-technique chemical characterization of a Stradivari decorated violin top plate

    Science.gov (United States)

    Malagodi, M.; Canevari, C.; Bonizzoni, L.; Galli, A.; Maspero, F.; Martini, M.

    2013-08-01

    This paper focuses on the characterization of the materials of a violin top plate made by Antonio Stradivari (17th century), with different diagnostic techniques and with an integrated and non-destructive analytical methodology to study surface coatings and decorations. The UV-induced visible fluorescence, optical digital microscopy, ED-XRF associated with micro-FTIR spectroscopy analysis, and dendrochronology were performed. The investigations were aimed to identify the presence of original varnish layers and to characterize the composition of the decorations, either the inlaid purflings or the composite false-inlay strip between them. Several results were achieved: (i) evidence of the absence of varnish layers on the surface as a result of extended and inappropriate restoring; (ii) identification of the dye used for the black layers of the purflings; (iii) characterization of the black matrix and the white elements of the decoration. Furthermore, a dendrochronological dating was performed. A copy of the top plate was realized with materials similar to those identified on the Stradivari original; the same analyses performed on the original model were carried out on the same areas of the copy.

  7. Zinc phthalocyanine thin film and chemical analyte interaction studies by density functional theory and vibrational techniques

    International Nuclear Information System (INIS)

    Saini, G S S; Singh, Sukhwinder; Kumar, Ranjan; Tripathi, S K; Kaur, Sarvpreet; Sathe, Vasant

    2009-01-01

    Thin films of zinc phthalocyanine have been deposited on KBr and glass substrates by the thermal evaporation method and characterized by the x-ray diffraction, optical, infrared and Raman techniques. The observed x-ray diffraction and infrared absorption spectra of as-deposited thin films suggest the presence of an α crystalline phase. Infrared and Raman spectra of thin films after exposure to vapours of ammonia and methanol have also been recorded. Shifts in the position of some IR and Raman bands in the spectra of exposed films have been observed. Some bands also show changes in their intensity on exposure. Increased charge on the phthalocyanine ring and out-of-plane distortion of the core due to interaction between zinc phthalocyanine and vapour molecules involving the fifth coordination site of the central metal ion may be responsible for the band shifts. Changes in the intensity of bands are interpreted in terms of the lowering of molecular symmetry from D 4h to C 4v due to doming of the core. Molecular parameters and Mulliken atomic charges of zinc phthalocyanine and its complexes with methanol and ammonia have been calculated from density functional theory. The binding energy of the complexes have also been calculated. Calculated values of the energy for different complexes suggest that axially coordinated vapour molecules form the most stable complex. Calculated Mulliken atomic charges show net charge transfer from vapour molecules to the phthalocyanine ring for the most stable complex.

  8. Chemical Separation Technique of Strontium-90 in the Soil Water as theStandard Methods for Environmental Radioactivity Analysis

    International Nuclear Information System (INIS)

    Ngasifudin-Hamdani; Suratman; Djoko-Sardjono, Ign; Winduanto-Wahyu SP

    2000-01-01

    Research about separation technique of strontium-90 from its materialmatrix using chemical precipitation method has been done. That technique wasapplied on the detection of radionuclide strontium-90 containing in the soilwater of near nuclear reactor facility P3TM BATAN in three location. The twoimportant parameters used in this technique were growth time of Y-90 andstirring time. The result shown that activity of strontium-90 in the pos-01was between 1.801x10 -19 - 9.616x10 -17 μCi/cm 3 , pos-02 was8.448x10 -19 - 1.003x X 10 -16 μCi/cm 3 and pos-03 was 6.719x10 -19 - 11.644x10 -16 μCi/cm 3 . From those data shown that activity of Sr-90in the soil water of near nuclear reactor facility P3TM BATAN was still belowthe limit value of maximum concentration permitted i.e. 4.0x10 -7 -3.5x10 -6 μCi/cm 3 . The statistic test using analysis of varian twofactorial with random block design shown that the activity of Sr-90 in thesoil water was influenced by the interaction which take place between growthlong time of Y-90 and stirring long time. (author)

  9. Chemical Variability and Biological Activities of Brassica rapa var. rapifera Parts Essential Oils Depending on Geographic Variation and Extraction Technique.

    Science.gov (United States)

    Saka, Boualem; Djouahri, Abderrahmane; Djerrad, Zineb; Terfi, Souhila; Aberrane, Sihem; Sabaou, Nasserdine; Baaliouamer, Aoumeur; Boudarene, Lynda

    2017-06-01

    In the present work, the Brassica rapa var. rapifera parts essential oils and their antioxidant and antimicrobial activities were investigated for the first time depending on geographic origin and extraction technique. Gas-chromatography (GC) and GC/mass spectrometry (MS) analyses showed several constituents, including alcohols, aldehydes, esters, ketones, norisoprenoids, terpenic, nitrogen and sulphur compounds, totalizing 38 and 41 compounds in leaves and root essential oils, respectively. Nitrogen compounds were the main volatiles in leaves essential oils and sulphur compounds were the main volatiles in root essential oils. Qualitative and quantitative differences were found among B. rapa var. rapifera parts essential oils collected from different locations and extracted by hydrodistillation and microwave-assisted hydrodistillation techniques. Furthermore, our findings showed a high variability for both antioxidant and antimicrobial activities. The highlighted variability reflects the high impact of plant part, geographic variation and extraction technique on chemical composition and biological activities, which led to conclude that we should select essential oils to be investigated carefully depending on these factors, in order to isolate the bioactive components or to have the best quality of essential oil in terms of biological activities and preventive effects in food. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  10. Speciation of trace elements in biological samples by nuclear analytical and related techniques coupled with chemical and biochemical separation

    International Nuclear Information System (INIS)

    Chen, C.Y.; Gao, Y.X.; Li, B.; Yu, H.W.; Li, Y.F.; Sun, J.; Chai, Z.F.

    2005-01-01

    In the past, most analytical problems relating to biological systems were addressed by measuring the total concentrations of elements. Now there is increasing interest of the importance of their chemical forms, in which an element is present in biological systems, e.g., the oxidation state, the binding state with macromolecules, or even the molecular structure. The biological effects of chromium, which is classified as an essential nutrient, are dependent upon its oxidation. state. In general, trivalent chromium is biochemically active, whereas hexavalent chromium is considered to be toxic. Mercury is one of serious environmental persistent pollutants. However, organic forms of mercury are known to possess much higher toxicity than inorganic mercury. Therefore, information on speciation is critically required in order to better understanding of their bioavailability, metabolism, transformation, and toxicity in vivo. Recently, chemical speciation of selenium, mercury, copper, zinc, iron, and so on, has been investigated by INAA, ICP-MS, XRF, EXAFS and related techniques combined with chemical and biochemical separation (extraction, chromatography, gel electrophoresis, etc.). INAA, XRF, and ICP-MS have superior advantages in aspect of multielemental analysis with high accuracy and sensitivity, which render the possibility of analyzing various elements of interest simultaneously. These offline or online techniques have been flexibly applied to different biological matrixes, such as human hair, serum, urine, various tissues and organs in our researches. In addition, EXAFS provides structural information about the moiety of metal centers up to a distance of approximately 4-5 Anstrom. For instance, hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. Imbalance of elements, such as Se, Zn, Fe, Cu, Cd, Ca, etc., has been found in the whole blood or serum of patients with HCC. We found that the profiles of Se, Cd, Fe, Zn and Cu-containing proteins

  11. Evaluation of three different decontamination techniques on biofilm formation, and on physical and chemical properties of resin composites.

    Science.gov (United States)

    André, Carolina Bosso; Dos Santos, Andressa; Pfeifer, Carmem Silvia; Giannini, Marcelo; Girotto, Emerson Marcelo; Ferracane, Jack Liborio

    2018-04-01

    This study evaluated three different sterilization/disinfection techniques for resin composites on bacterial growth and surface modification after decontamination. Two resin composites were sterilized/disinfected with three different techniques: UV light, 1% chloramine T, and 70% ethanol. Four different times were used for each technique to determine the shortest time that the solution or UV light was effective. The influence of sterilization/disinfection technique on bacterial growth was evaluated by analyzing the metabolic activity, using the AlamarBlue™ assay, bacterial viability, and SEM images from biofilms of Streptococcus mutans. The surface change, after the process, was analyzed with ATR/FTIR and SEM images. The solutions used for decontamination (1% chloramine-T and 70% ethanol) were analyzed with 1 H-NMR to identify any resin compounds leached during the process. One minute of decontamination was efficient for all three methods tested. Chloramine-T increased the surface porosity on resin composites, no changes were observed for UV light and 70% ethanol, however, 1 H-NMR identified leached monomers only when 70% ethanol was used. No chemical change of the materials was found under ATR/FTIR analyses after the decontamination process. Chloramine-T, with no previous wash, increased the bacterial viability for both resin composites and increased the bacterial metabolism for the resin composite without fluoride. UV light had no interference on the resin composites properties tested using 1 min of exposure compared to the other decontamination methods. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 945-953, 2018. © 2017 Wiley Periodicals, Inc.

  12. Proficiency Testing for Determination of Water Content in Toluene of Chemical Reagents by iteration robust statistic technique

    Science.gov (United States)

    Wang, Hao; Wang, Qunwei; He, Ming

    2018-05-01

    In order to investigate and improve the level of detection technology of water content in liquid chemical reagents of domestic laboratories, proficiency testing provider PT0031 (CNAS) has organized proficiency testing program of water content in toluene, 48 laboratories from 18 provinces/cities/municipals took part in the PT. This paper introduces the implementation process of proficiency testing for determination of water content in toluene, including sample preparation, homogeneity and stability test, the results of statistics of iteration robust statistic technique and analysis, summarized and analyzed those of the different test standards which are widely used in the laboratories, put forward the technological suggestions for the improvement of the test quality of water content. Satisfactory results were obtained by 43 laboratories, amounting to 89.6% of the total participating laboratories.

  13. Density-controllable nonvolatile memory devices having metal nanocrystals through chemical synthesis and assembled by spin-coating technique

    International Nuclear Information System (INIS)

    Wang Guangli; Chen Yubin; Shi Yi; Pu Lin; Pan Lijia; Zhang Rong; Zheng Youdou

    2010-01-01

    A novel two-step method is employed, for the first time, to fabricate nonvolatile memory devices that have metal nanocrystals. First, size-averaged Au nanocrystals are synthesized chemically; second, they are assembled into memory devices by a spin-coating technique at room temperature. This attractive approach makes it possible to tailor the diameter and control the density of nanocrystals individually. In addition, processes at room temperature prevent Au diffusion, which is a main concern for the application of metal nanocrystal-based memory. The experimental results, both the morphology characterization and the electrical measurements, reveal that there is an optimum density of nanocrystal monolayer to balance between long data retention and a large hysteresis memory window. At the same time, density-controllable devices could also feed the preferential emphasis on either memory window or retention time. All these facts confirm the advantages and novelty of our two-step method. (semiconductor devices)

  14. Chemical composition and the nutritive value of pistachio epicarp (in situ degradation and in vitro gas production techniques

    Directory of Open Access Journals (Sweden)

    Somayeh Bakhshizadeh

    2014-04-01

    Full Text Available The nutritive value of pistachio epicarp (PE was evaluated by in situ and in vitro techniques. Chemical analysis indicated that PE was high in crude protein (11.30% and low in neutral detergent fiber (26.20%. Total phenols, total tannins, condensed tannins and hydrolysable tannins contents in PE were 8.29%, 4.48%, 0.49% and 3.79%, respectively. Ruminal dry matter and crude protein degradation after 48 hr incubation were 75.21% and 82.52%, respectively. The gas production volume at 48 hr for PE was 122.47 mL g-1DM. As a whole, adding polyethylene glycol (PEG to PE increased (p < 0.05 gas production volumes, organic matter digestibility and the metabolizable energy that illustrated inhibitory effect of phenolics on rumen microbial fermentation and the positive influence of PEG on digestion PE. The results showed that PE possessed potentials to being used as feed supplements.

  15. Chemically durable iron phosphate glasses for vitrifying sodium bearing waste (SBW) using conventional and cold crucible induction melting (CCIM) techniques

    Energy Technology Data Exchange (ETDEWEB)

    Kim, C.W. E-mail: cheol@umr.edu; Ray, C.S.; Zhu, D.; Day, D.E.; Gombert, D.; Aloy, A.; Mogus-Milankovic, A.; Karabulut, M

    2003-11-01

    A simulated sodium bearing waste (SBW) was successfully vitrified in iron phosphate glasses (IPG) at a maximum waste loading of 40 wt% using conventional and cold crucible induction melting (CCIM) techniques. No sulfate segregation or crystalline phases were detectable in the IPG when examined by SEM and XRD. The IPG wasteforms containing 40 wt% SBW satisfy current DOE requirements for aqueous chemical durability as evaluated from their bulk dissolution rate (D{sub R}), product consistency test, and vapor hydration test. The fluid IPG wasteforms can be melted at a relatively low temperature (1000 deg. C) and for short times (<6 h). These properties combined with a significantly higher waste loading, and the feasibility of CCIM melting offer considerable savings in time, energy, and cost for vitrifying the SBW stored at the Idaho National Engineering and Environmental Laboratory in iron phosphate glasses.

  16. Characterizations on the microstructures of LiMn2O4 prepared by a simple soft-chemical technique

    International Nuclear Information System (INIS)

    Wei Yingjin; Kim, Kwang Bum; Chen Gang; Park, Chul W.

    2008-01-01

    LiMn 2 O 4 powders were prepared by a simple soft-chemical technique at different temperatures. X-ray diffraction and thermogravimetric analysis suggested that the material prepared at 800 deg. C was stoichiometric LiMn 2 O 4 , whereas those prepared at 600 and 700 deg. C were Li[Mn 0.77 3+ Mn 1.23 4+ ]O 4.115 and Li[Mn 0.85 3+ Mn 1.15 4+ ]O 4.075 . Several typical XRD peaks of the compounds were investigated with an aim to elucidate (i) the Li immigration to the 16d octahedral sites, (ii) the partial tetragonal phase transition of the material and (iii) the mean coherent domain size and microstrain. SEM study showed that the particle size of the materials increased with heating temperature. The activation energy for the material particle growth was determined as 30.4 kJ mol -1

  17. Speciation of Fe(II) and Fe(III) in Contaminated Aquifer Sediments Using Chemical Extraction Techniques

    DEFF Research Database (Denmark)

    Heron, Gorm; Crouzet, Catherine.; Bourg, Alain C. M.

    1994-01-01

    The iron mineralogy of aquifer sediments was described by chemical extraction techniques. Single-step extractions including 1 M CaC12, NaAc, oxalate, dithionite, Ti(II1)- EDTA, 0.5 M HC1,5 M HC1, hot 6 M HC1, and a sequential extraction by HI and CrIIHC1 were tested on standard iron minerals...... species are distinguished as AVS (acid volatile sulfide, hot 6 M HC1 extraction) and pyrite (sequential HI and CrIIHC1 extraction). By including a cold 5 M HC1 extraction, the total distribution of the major reactive Fe(I1) and Fe(II1) fractions in aquifer sediments can be assessed....

  18. Chemical composition and the nutritive value of pistachio epicarp (in situ degradation and in vitro gas production techniques).

    Science.gov (United States)

    Bakhshizadeh, Somayeh; Taghizadeh, Akbar; Janmohammadi, Hossein; Alijani, Sadegh

    2014-01-01

    The nutritive value of pistachio epicarp (PE) was evaluated by in situ and in vitro techniques. Chemical analysis indicated that PE was high in crude protein (11.30%) and low in neutral detergent fiber (26.20%). Total phenols, total tannins, condensed tannins and hydrolysable tannins contents in PE were 8.29%, 4.48%, 0.49% and 3.79%, respectively. Ruminal dry matter and crude protein degradation after 48 hr incubation were 75.21% and 82.52%, respectively. The gas production volume at 48 hr for PE was 122.47 mL g(-1)DM. As a whole, adding polyethylene glycol (PEG) to PE increased (p gas production volumes, organic matter digestibility and the metabolizable energy that illustrated inhibitory effect of phenolics on rumen microbial fermentation and the positive influence of PEG on digestion PE. The results showed that PE possessed potentials to being used as feed supplements.

  19. Controlling the quality of nanocrystalline silicon made by hot-wire chemical vapor deposition by using a reverse H2 profiling technique

    NARCIS (Netherlands)

    Li, H. B. T.; Franken, R.H.; Stolk, R.L.; van der Werf, C.H.M.; Rath, J.K.; Schropp, R.E.I.

    2008-01-01

    Hydrogen profiling, i.e., decreasing the H2 dilution during deposition, is a well-known technique to maintain a proper crystalline ratio of the nanocrystalline (nc-Si:H) absorber layers of plasma-enhanced chemical vapor-deposited (PECVD) thin film solar cells. With this technique a large increase in

  20. Traditional versus commercial food processing techniques - A comparative study based on chemical analysis of selected foods consumed in rural Zimbabwe.

    Directory of Open Access Journals (Sweden)

    Abraham I. C. Mwadiwa

    2012-01-01

    Full Text Available With the advent of industrialisation, food processors are constantly looking for ways to cut costs, increase production and maximise profits at the expense of quality. Commercial food processors have since shifted their focus from endogenous ways of processing food to more profitable commercial food processing techniques. The aim of this study was to investigate the holistic impact of commercial food processing techniques on nutrition by comparing commercially (industrially processed food products and endogenously processed food products through chemical analysis of selected foods. Eight food samples which included commercially processed peanut butter, mealie-meal, dried vegetables (mufushwa and rice and endogenously processed peanut butter, mealie-meal, dried vegetables (mufushwa and rice were randomly sampled from rural communities in the south-eastern and central provinces of Zimbabwe. They were analysed for ash, zinc, iron, copper, magnesium, protein, fat, carbohydrates, energy, crude fibre, vitamin C and moisture contents. The results of chemical analysis indicate that endogenously processed mealie-meal, dried vegetables and rice contained higher ash values of 2.00g/100g, 17.83g/100g, and 3.28g/100g respectively than commercially processed mealie-meal, dried vegetables and rice, which had ash values of 1.56g/100g, 15.25g/100g and 1.46g/100g respectively. The results also show that endogenously processed foods have correspondingly higher iron, zinc and magnesium contents and, on the whole, a higher protein content. The results also indicate that commercially processed foods have higher fat and energy contents. The result led to the conclusion that the foods are likely to pose a higher risk of causing adverse conditions to health, such as obesity and cardiovascular diseases to susceptible individuals. Based on these findings, it can, therefore, be concluded that endogenously processed foods have a better nutrient value and health implications

  1. Plasmonic metamaterial-based chemical converted graphene/TiO2/Ag thin films by a simple spray pyrolysis technique

    Science.gov (United States)

    Kumar, Promod; Swart, H. C.

    2018-04-01

    Graphene based hybrid nanostructures have received special attention in both the scientific and technological development due to their unique physicochemical behavior, which make them attractive in various applications such as, batteries, supercapacitors, fuel cells, solar cells, photovoltaic devices and bio-sensors. In the present study, the role of plasmonic metamaterials in light trapping photovoltaics for inorganic semiconducting materials by a simple and low cost spray pyrolysis technique has been studied. The plasmonic metamaterials thin film has been fabricated by depositing chemically converted graphene (CCG) onto TiO2-Ag nanoparticles which has a low resistivity and a low electron-hole recombination probability. The localized surface plasmon resonance at the metal-dielectric interface for the Ag nanoparticles has been observed at 403 nm after depositing chemical converted graphene (CCG) on the TiO2-Ag thin film. The results suggest that the stacking order of the CCG/TiO2/Ag plasmonic metamaterials samples did not change the band gap of TiO2 while it changed the conductivity of the film. Thus the diffusion of the noble metals in the glass and TiO2 matrices based thin films can trap the light of a particular wavelength by mean of plasmonic resonance and may be useful for superior photovoltaic and optoelectronic applications.

  2. Effects of Chemical and Physical Enhancement Techniques on Transdermal Delivery of Cyanocobalamin (Vitamin B12 In Vitro

    Directory of Open Access Journals (Sweden)

    Ajay K. Banga

    2011-08-01

    Full Text Available Vitamin B12 deficiency, which may result in anemia and nerve damage if left untreated, is currently treated by administration of cyanocobalamin via oral or intramuscular routes. However, these routes are associated with absorption and compliance issues which have prompted us to investigate skin as an alternative site of administration. Delivery through skin, however, is restricted to small and moderately lipophilic molecules due to the outermost barrier, the stratum corneum (SC. In this study, we have investigated the effect of different enhancement techniques, chemical enhancers (ethanol, oleic acid, propylene glycol, iontophoresis (anodal iontophoresis and microneedles (soluble maltose microneedles, which may overcome this barrier and improve cyanocobalamin delivery. Studies with different chemical enhancer formulations indicated that ethanol and oleic acid decreased the lag time while propylene glycol based formulations increased the lag time. The formulation with ethanol (50%, oleic acid (10% and propylene glycol (40% showed the maximum improvement in delivery. Iontophoresis and microneedle treatments resulted in enhanced permeation levels compared to passive controls. These enhancement approaches can be explored further to develop alternative treatment regimens.

  3. In vitro evaluation of the chemical and morphological changes of the enamel surface using different bleaching techniques

    International Nuclear Information System (INIS)

    Mattos, Alessandra de Siervi

    2003-01-01

    'In vitro' evaluation through MEV and EDS of the morphological and chemical changes, respectively, of the bovine enamel, submitted to different bleaching techniques. For the MEV evaluation eighteen apical thirds were pigmented and divided into two parts. One half of each sample was the control and the other half was bleached according to the protocol of each test group (n= 6). Group I - home bleaching with a 10% carbamide peroxide; group II bleaching with 35% hydrogen peroxide and LED; group III - bleaching with 35% hydrogen peroxide with diode laser bleaching. The same procedure was done with the eighteen samples which were analyzed through EDS and which had their buccal surface grinded and polished before the bleaching procedure in order to obtain more precise values of the fraction of calcium and phosphorus. The results showed no morphological changes among the analyzed control halves and the bleached halves. There was not a statistical significant difference about Ca and P values, among the control halves and the bleached halves regarding the chemical components (p< 0,05). (author)

  4. Microscopy and Chemical Inversing Techniques to Determine the Photonic Crystal Structure of Iridescent Beetle Scales in the Cerambycidae Family

    Science.gov (United States)

    Richey, Lauren; Gardner, John; Standing, Michael; Jorgensen, Matthew; Bartl, Michael

    2010-10-01

    Photonic crystals (PCs) are periodic structures that manipulate electromagnetic waves by defining allowed and forbidden frequency bands known as photonic band gaps. Despite production of PC structures operating at infrared wavelengths, visible counterparts are difficult to fabricate because periodicities must satisfy the diffraction criteria. As part of an ongoing search for naturally occurring PCs [1], a three-dimensional array of nanoscopic spheres in the iridescent scales of the Cerambycidae insects A. elegans and G. celestis has been found. Such arrays are similar to opal gemstones and self-assembled colloidal spheres which can be chemically inverted to create a lattice-like PC. Through a chemical replication process [2], scanning electron microscopy analysis, sequential focused ion beam slicing and three-dimensional modeling, we analyzed the structural arrangement of the nanoscopic spheres. The study of naturally occurring structures and their inversing techniques into PCs allows for diversity in optical PC fabrication. [1] J.W. Galusha et al., Phys. Rev. E 77 (2008) 050904. [2] J.W. Galusha et al., J. Mater. Chem. 20 (2010) 1277.

  5. Measurements of the aerosol chemical composition and mixing state in the Po Valley using multiple spectroscopic techniques

    Science.gov (United States)

    Decesari, S.; Allan, J.; Plass-Duelmer, C.; Williams, B. J.; Paglione, M.; Facchini, M. C.; O'Dowd, C.; Harrison, R. M.; Gietl, J. K.; Coe, H.; Giulianelli, L.; Gobbi, G. P.; Lanconelli, C.; Carbone, C.; Worsnop, D.; Lambe, A. T.; Ahern, A. T.; Moretti, F.; Tagliavini, E.; Elste, T.; Gilge, S.; Zhang, Y.; Dall'Osto, M.

    2014-11-01

    The use of co-located multiple spectroscopic techniques can provide detailed information on the atmospheric processes regulating aerosol chemical composition and mixing state. So far, field campaigns heavily equipped with aerosol mass spectrometers have been carried out mainly in large conurbations and in areas directly affected by their outflow, whereas lesser efforts have been dedicated to continental areas characterised by a less dense urbanisation. We present here the results obtained at a background site in the Po Valley, Italy, in summer 2009. For the first time in Europe, six state-of-the-art spectrometric techniques were used in parallel: aerosol time-of-flight mass spectrometer (ATOFMS), two aerosol mass spectrometers (high-resolution time-of-flight aerosol mass spectrometer - HR-ToF-AMS and soot particle aerosol mass spectrometer - SP-AMS), thermal desorption aerosol gas chromatography (TAG), chemical ionisation mass spectrometry (CIMS) and (offline) proton nuclear magnetic resonance (1H-NMR) spectroscopy. The results indicate that, under high-pressure conditions, atmospheric stratification at night and early morning hours led to the accumulation of aerosols produced by anthropogenic sources distributed over the Po Valley plain. Such aerosols include primary components such as black carbon (BC), secondary semivolatile compounds such as ammonium nitrate and amines and a class of monocarboxylic acids which correspond to the AMS cooking organic aerosol (COA) already identified in urban areas. In daytime, the entrainment of aged air masses in the mixing layer is responsible for the accumulation of low-volatility oxygenated organic aerosol (LV-OOA) and also for the recycling of non-volatile primary species such as black carbon. According to organic aerosol source apportionment, anthropogenic aerosols accumulating in the lower layers overnight accounted for 38% of organic aerosol mass on average, another 21% was accounted for by aerosols recirculated in

  6. Effect of Different Catalyst Deposition Technique on Aligned Multiwalled Carbon Nanotubes Grown by Thermal Chemical Vapor Deposition

    Directory of Open Access Journals (Sweden)

    Mohamed Shuaib Mohamed Saheed

    2014-01-01

    Full Text Available The paper reported the investigation of the substrate preparation technique involving deposition of iron catalyst by electron beam evaporation and ferrocene vaporization in order to produce vertically aligned multiwalled carbon nanotubes array needed for fabrication of tailored devices. Prior to the growth at 700°C in ethylene, silicon dioxide coated silicon substrate was prepared by depositing alumina followed by iron using two different methods as described earlier. Characterization analysis revealed that aligned multiwalled carbon nanotubes array of 107.9 µm thickness grown by thermal chemical vapor deposition technique can only be achieved for the sample with iron deposited using ferrocene vaporization. The thick layer of partially oxidized iron film can prevent the deactivation of catalyst and thus is able to sustain the growth. It also increases the rate of permeation of the hydrocarbon gas into the catalyst particles and prevents agglomeration at the growth temperature. Combination of alumina-iron layer provides an efficient growth of high density multiwalled carbon nanotubes array with the steady growth rate of 3.6 µm per minute for the first 12 minutes and dropped by half after 40 minutes. Thicker and uniform iron catalyst film obtained from ferrocene vaporization is attributed to the multidirectional deposition of particles in the gaseous form.

  7. Correlated analysis of 2 MeV proton-induced radiation damage in CdZnTe crystals using photoluminescence and thermally stimulated current techniques

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Yaxu [State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072 (China); Key Laboratory of Radiation Detection Materials and Devices of Ministry of Industry and Information Technology, Northwestern Polytechnical University, Xi’an 710072 (China); Jie, Wanqi, E-mail: jwq@nwpu.edu.cn [State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072 (China); Key Laboratory of Radiation Detection Materials and Devices of Ministry of Industry and Information Technology, Northwestern Polytechnical University, Xi’an 710072 (China); Rong, Caicai [Institute of Modern Physics, Applied Ion Beam Physics Laboratory, Fudan University, Shanghai 200433 (China); Wang, Yuhan; Xu, Lingyan; Xu, Yadong [State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072 (China); Key Laboratory of Radiation Detection Materials and Devices of Ministry of Industry and Information Technology, Northwestern Polytechnical University, Xi’an 710072 (China); Lv, Haoyan; Shen, Hao [Institute of Modern Physics, Applied Ion Beam Physics Laboratory, Fudan University, Shanghai 200433 (China); Du, Guanghua [Materials Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Fu, Xu [State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072 (China); Key Laboratory of Radiation Detection Materials and Devices of Ministry of Industry and Information Technology, Northwestern Polytechnical University, Xi’an 710072 (China); and others

    2016-11-01

    Highlights: • 2 MeV proton-induced radiation damage in CdZnTe crystals is investigated by PL and TSC techniques. • The influence of radiation damage on the luminescent and electrical properties of CdZnTe crystals is studied. • Intensity of PL spectrum is found to decrease significantly in irradiated regions, suggesting the increase of non-radiative recombination centers. • A correlated analysis of PL and TSC spectra suggests that the density of dislocations and A-centers increase after proton irradiation. - Abstract: Radiation damage induced by 2 MeV protons in CdZnTe crystals has been studied by means of photoluminescence (PL) and thermally stimulated current (TSC) techniques. A notable quenching of PL intensity is observed in the regions irradiated with a fluence of 6 × 10{sup 13} p/cm{sup 2}, suggesting the increase of non-radiative recombination centers. Moreover, the intensity of emission peak D{sub complex} centered at 1.48 eV dominates in the PL spectrum obtained from irradiated regions, ascribed to the increase of interstitial dislocation loops and A centers. The intensity of TSC spectra in irradiated regions decreases compared to the virgin regions, resulting from the charge collection inefficiency caused by proton-induced recombination centers. By comparing the intensity of identified traps obtained from numerical fitting using simultaneous multiple peak analysis (SIMPA) method, it suggests that proton irradiation under such dose can introduce high density of dislocation and A-centers in CdZnTe crystals, consistent with PL results.

  8. Comparison of Bispectral Index™ values during the flotation restricted environmental stimulation technique and results for stage I sleep: a prospective pilot investigation.

    Science.gov (United States)

    Dunham, C Michael; McClain, Jesse V; Burger, Amanda

    2017-11-29

    To determine whether Bispectral Index™ values obtained during flotation-restricted environment stimulation technique have a similar profile in a single observation compared to literature-derived results found during sleep and other relaxation-induction interventions. Bispectral Index™ values were as follows: awake-state, 96.6; float session-1, 84.3; float session-2, 82.3; relaxation-induction, 82.8; stage I sleep, 86.0; stage II sleep, 66.2; and stages III-IV sleep, 45.1. Awake-state values differed from float session-1 (%difference 12.7%; Cohen's d = 3.6) and float session-2 (%difference 14.8%; Cohen's d = 4.6). Relaxation-induction values were similar to float session-1 (%difference 1.8%; Cohen's d = 0.3) and float session-2 (%difference 0.5%; Cohen's d = 0.1). Stage I sleep values were similar to float session-1 (%difference 1.9%; Cohen's d = 0.4) and float session-2 (%difference 4.3%; Cohen's d = 1.0). Stage II sleep values differed from float session-1 (%difference 21.5%; Cohen's d = 4.3) and float session-2 (%difference 19.6%; Cohen's d = 4.0). Stages III-IV sleep values differed from float session-1 (%difference 46.5%; Cohen's d = 5.6) and float session-2 (%difference 45.2%; Cohen's d = 5.4). Bispectral Index™ values during flotation were comparable to those found in stage I sleep and nadir values described with other relaxation-induction techniques.

  9. A technique for estimating the probability of radiation-stimulated failures of integrated microcircuits in low-intensity radiation fields: Application to the Spektr-R spacecraft

    Science.gov (United States)

    Popov, V. D.; Khamidullina, N. M.

    2006-10-01

    In developing radio-electronic devices (RED) of spacecraft operating in the fields of ionizing radiation in space, one of the most important problems is the correct estimation of their radiation tolerance. The “weakest link” in the element base of onboard microelectronic devices under radiation effect is the integrated microcircuits (IMC), especially of large scale (LSI) and very large scale (VLSI) degree of integration. The main characteristic of IMC, which is taken into account when making decisions on using some particular type of IMC in the onboard RED, is the probability of non-failure operation (NFO) at the end of the spacecraft’s lifetime. It should be noted that, until now, the NFO has been calculated only from the reliability characteristics, disregarding the radiation effect. This paper presents the so-called “reliability” approach to determination of radiation tolerance of IMC, which allows one to estimate the probability of non-failure operation of various types of IMC with due account of radiation-stimulated dose failures. The described technique is applied to RED onboard the Spektr-R spacecraft to be launched in 2007.

  10. Differential sensitivity to the antifouling chemical medetomidine between wood frog and American toad tadpoles with evidence for low-dose stimulation and high-dose inhibition of metamorphosis.

    Science.gov (United States)

    Fong, Peter P; Lambert, Olivia J; Hoagland, Margot L; Kurtz, Emily R

    2018-05-05

    Antifouling chemicals are legacy contaminants in aquatic ecosystems. Previous experiments have shown that a 14-day exposure to the antifouling chemical medetomidine delays metamorphosis and reduces body mass in wood frog tadpoles. In the present study, we exposed wood frog tadpoles to medetomidine for 3, 7, and 10 days at 100 nM, 1 μM, and 10 μM. We also exposed American toad tadpoles to medetomidine for 3 days at four concentrations (10 nM, 100 nM, 1 μM, and 10 μM) in static renewal experiments. In each experiment, we measured growth, frequency and time to metamorphosis, and mass at metamorphosis. In both species, medetomidine significantly slowed development as measured by the Gosner stage. After 34 days in culture, wood frog tadpoles exposed to 1 and 10 μM medetomidine for as few as 3 days were significantly less developed compared to controls. Toads exposed to 1 μM medetomidine for 3 days were also significantly less developed on day 27, but by day 34, there was no difference from controls. For wood frogs, medetomidine significantly affected time to metamorphosis with a trend for tadpoles at lower concentrations metamorphosing sooner than those at higher concentrations. While medetomidine affected time to metamorphosis in wood frogs, it did not affect fresh mass, dry mass, or mortality compared to controls. Wood frog tadpoles that did not metamorphose after over 90 days in culture were more frequent in high-concentration groups than in the control. In toads, 10 μM medetomidine was 100% lethal within 23 days, but at the same concentration and duration, no wood frog tadpoles died. Lower concentrations were also significantly lethal to toads compared to controls, but tadpoles that survived in 10 and 100 nM metamorphosed sooner than those in 1 μM. Fresh mass of toad tadpoles exposed to 1 μm was significantly smaller at metamorphosis compared to that of controls. Medetomidine also affected the behavior of tadpoles. In toads, medetomidine

  11. Geothermal Reservoir Well Stimulation Program: technology transfer

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-01

    Each of the following types of well stimulation techniques are summarized and explained: hydraulic fracturing; thermal; mechanical, jetting, and drainhole drilling; explosive and implosive; and injection methods. Current stimulation techniques, stimulation techniques for geothermal wells, areas of needed investigation, and engineering calculations for various techniques. (MHR)

  12. The Combination of DGT Technique and Traditional Chemical Methods for Evaluation of Cadmium Bioavailability in Contaminated Soils with Organic Amendment

    Science.gov (United States)

    Yao, Yu; Sun, Qin; Wang, Chao; Wang, Pei-Fang; Miao, Ling-Zhan; Ding, Shi-Ming

    2016-01-01

    Organic amendments have been proposed as a means of remediation for Cd-contaminated soils. However, understanding the inhibitory effects of organic materials on metal immobilization requires further research. In this study colza cake, a typical organic amendment material, was investigated in order to elucidate the ability of this material to reduce toxicity of Cd-contaminated soil. Available concentrations of Cd in soils were measured using an in situ diffusive gradients in thin films (DGT) technique in combination with traditional chemical methods, such as HOAc (aqua regia), EDTA (ethylene diamine tetraacetic acid), NaOAc (sodium acetate), CaCl2, and labile Cd in pore water. These results were applied to predict the Cd bioavailability after the addition of colza cake to Cd-contaminated soil. Two commonly grown cash crops, wheat and maize, were selected for Cd accumulation studies, and were found to be sensitive to Cd bioavailability. Results showed that the addition of colza cake may inhibit the growth of wheat and maize. Furthermore, the addition of increasing colza cake doses led to decreasing shoot and root biomass accumulation. However, increasing colza cake doses did lead to the reduction of Cd accumulation in plant tissues, as indicated by the decreasing Cd concentrations in shoots and roots. The labile concentration of Cd obtained by DGT measurements and the traditional chemical extraction methods, showed the clear decrease of Cd with the addition of increasing colza cake doses. All indicators showed significant positive correlations (p soil solution decreased with increasing colza cake doses. This was reflected by the decreases in the ratio (R) value of CDGT to Csol. Our study suggests that the sharp decrease in R values could not only reflect the extremely low capability of labile Cd to be released from its solid phase, but may also be applied to evaluate the abnormal growth of the plants. PMID:27314376

  13. The Combination of DGT Technique and Traditional Chemical Methods for Evaluation of Cadmium Bioavailability in Contaminated Soils with Organic Amendment.

    Science.gov (United States)

    Yao, Yu; Sun, Qin; Wang, Chao; Wang, Pei-Fang; Miao, Ling-Zhan; Ding, Shi-Ming

    2016-06-15

    Organic amendments have been proposed as a means of remediation for Cd-contaminated soils. However, understanding the inhibitory effects of organic materials on metal immobilization requires further research. In this study colza cake, a typical organic amendment material, was investigated in order to elucidate the ability of this material to reduce toxicity of Cd-contaminated soil. Available concentrations of Cd in soils were measured using an in situ diffusive gradients in thin films (DGT) technique in combination with traditional chemical methods, such as HOAc (aqua regia), EDTA (ethylene diamine tetraacetic acid), NaOAc (sodium acetate), CaCl₂, and labile Cd in pore water. These results were applied to predict the Cd bioavailability after the addition of colza cake to Cd-contaminated soil. Two commonly grown cash crops, wheat and maize, were selected for Cd accumulation studies, and were found to be sensitive to Cd bioavailability. Results showed that the addition of colza cake may inhibit the growth of wheat and maize. Furthermore, the addition of increasing colza cake doses led to decreasing shoot and root biomass accumulation. However, increasing colza cake doses did lead to the reduction of Cd accumulation in plant tissues, as indicated by the decreasing Cd concentrations in shoots and roots. The labile concentration of Cd obtained by DGT measurements and the traditional chemical extraction methods, showed the clear decrease of Cd with the addition of increasing colza cake doses. All indicators showed significant positive correlations (p soil solution decreased with increasing colza cake doses. This was reflected by the decreases in the ratio (R) value of CDGT to Csol. Our study suggests that the sharp decrease in R values could not only reflect the extremely low capability of labile Cd to be released from its solid phase, but may also be applied to evaluate the abnormal growth of the plants.

  14. Optically stimulated luminescence of ZnO obtained by thermal treatment of ZnS chemically synthesized; Luminiscencia opticamente estimulada de ZnO obtenido por tratamiento termico de ZnS sintetizado quimicamente

    Energy Technology Data Exchange (ETDEWEB)

    Cruz V, C.; Burruel I, S.E.; Orante B, V.R.; Grijalva M, H.; Perez S, R.; Bernal, R. [Universidad de Sonora, A.P. 130, Hermosillo (Mexico)

    2005-07-01

    In this work, we report the optically stimulated luminescence (OSL) dosimetry of new nano phosphors of ZnO obtained by thermal annealing of chemically synthesized ZnS powder. The synthesized ZnS nano powder was compressed in order to form pellet shaped pellets, which were afterwards subjected to a thermal annealing at 700 C during 24 h under air atmosphere. X-ray diffraction (XRD) patterns and energy-disperse X-ray Spectrometry (EDS) analyses confirmed the transformation of ZnS to ZnO. Samples were exposed to several doses of beta radiation up to 600 Gy, and the optically stimulated luminescence with 470 nm wavelength light was recorded as a function of dose. The intensity of the OSL signal increases by increasing dose, for what it is concluded that these new phosphor materials are suitable to be used in optically stimulated luminescence dosimetry. (Author)

  15. Wet chemical synthesis of quantum confined nanostructured tin oxide thin films by successive ionic layer adsorption and reaction technique

    Energy Technology Data Exchange (ETDEWEB)

    Murali, K.V., E-mail: kvmuralikv@gmail.com [School of Pure and Applied Physics, Department of Physics, Kannur University, Kerala 670327 (India); Department of Physics, Nehru Arts and Science College, Kanhangad, Kerala 671314 (India); Ragina, A.J. [School of Pure and Applied Physics, Department of Physics, Kannur University, Kerala 670327 (India); Department of Physics, Nehru Arts and Science College, Kanhangad, Kerala 671314 (India); Preetha, K.C. [School of Pure and Applied Physics, Department of Physics, Kannur University, Kerala 670327 (India); Department of Physics, Sree Narayana College, Kannur, Kerala 670007 (India); Deepa, K.; Remadevi, T.L. [School of Pure and Applied Physics, Department of Physics, Kannur University, Kerala 670327 (India); Department of Physics, Pazhassi Raja N.S.S. College, Mattannur, Kerala 670702 (India)

    2013-09-01

    Graphical abstract: - Highlights: • Quantum confined SnO{sub 2} thin films were synthesized at 80 °C by SILAR technique. • Film formation mechanism is discussed. • Films with snow like crystallite morphology offer high specific surface area. • The blue-shifted value of band gap confirmed the quantum confinement effect. • Present synthesis has advantages – low cost, low temperature and green friendly. - Abstract: Quantum confined nanostructured SnO{sub 2} thin films were synthesized at 353 K using ammonium chloride (NH{sub 4}Cl) and other chemicals by successive ionic layer adsorption and reaction technique. Film formation mechanism is discussed. Structural, morphological, optical and electrical properties were investigated and compared with the as-grown and annealed films fabricated without NH{sub 4}Cl solution. SnO{sub 2} films were polycrystalline with crystallites of tetragonal structure with grain sizes lie in the 5–8 nm range. Films with snow like crystallite morphology offer high specific surface area. The blue-shifted value of band gap of as-grown films confirmed the quantum confinement effect of grains. Refractive index of the films lies in the 2.1–2.3 range. Films prepared with NH{sub 4}Cl exhibit relatively lower resistivity of the order of 10{sup 0}–10{sup −1} Ω cm. The present synthesis has advantages such as low cost, low temperature and green friendly, which yields small particle size, large surface–volume ratio, and high crystallinity SnO{sub 2} films.

  16. A review of the new minimally invasive brain stimulation techniques in psychiatry Revisão de novas técnicas minimamente invasivas de estimulação cerebral em psiquiatria

    Directory of Open Access Journals (Sweden)

    Jeong-Ho Chae

    2001-06-01

    Full Text Available New knowledge about the specific brain regions involved in neuropsychiatric disorders is rapidly evolving due to recent advances in functional neuroimaging techniques. The ability to stimulate the brain in awake alert adults without neurosurgery is a real advance that neuroscientists have long dreamed for. Several novel and minimally invasive techniques to stimulate the brain have recently developed. Among these newer somatic interventions, transcranial magnetic stimulation (TMS, vagus nerve stimulation (VNS and deep brain stimulation (DBS show promise as therapeutic tools in the treatment of neuropsychiatric disorders. This article reviews the history, methodology, and the future of these minimally invasive brain stimulation (MIBS techniques and their emerging research and therapeutic applications in psychiatryO conhecimento acerca de regiões específicas do cérebro envolvidas em transtornos psiquiátricos está em franca expansão como resultado dos avanços recentes em técnicas de neuroimagem funcional. A capacidade de estimular o cérebro em adultos despertos em estado de alerta, sem necessidade de neurocirurgia, é um avanço real sonhado havia muito pelos neurocientistas. Recentemente, desenvolveram-se várias novas técnicas minimamente invasivas para estimular o cérebro. Entre essas novas intervenções somáticas, a estimulação transcraniana magnética (ETM, a estimulação do nervo vago (ENV e a estimulação cerebral profunda (ECP revelam-se promissoras ferramentas terapêuticas no tratamento de transtornos neuropsiquiátricos. Neste artigo se faz uma revisão da história, da metodologia e das perspectivas futuras das técnicas minimamente invasivas de estimulação cerebral (ECMI e das pesquisas e aplicações terapêuticas em psiquiatria

  17. Elucidating Adverse Nutritional Implications of Exposure to Endocrine-Disrupting Chemicals and Mycotoxins through Stable Isotope Techniques.

    Science.gov (United States)

    Owino, Victor O; Cornelius, Carolin; Loechl, Cornelia U

    2018-03-23

    Multiple drivers of the double burden of malnutrition (DBM) include a rapid shift from predominantly plant-based diets to energy-dense foods based on meats, milk, animal fats and vegetable oils. The shift to overweight and obesity is driven by increased exposure to mass media, urbanization, technological advances in food processing, rising income and increased population density associated with increased access to cheap foods. At the same time, undernutrition persists mainly due to food insecurity and lack of access to safe water, sanitation and adequate health care. All known nutrition interventions result in only one third reduction in stunting. Little consideration has been given to hazardous exposure to endocrine disrupting chemicals (EDCs) and microbial toxins as major components of the malnutrition-causal framework. These hazards include microbial toxins, for example, mycotoxins, and environmental pollutants such as persistent organic pollutants (POPs), some of which are known to disrupt the endocrine system. These hazards sit at the cross road of undernutrition and overweight and obesity since the exposure cuts across the critical window of opportunity (the first 1000 days). In this review, we update on the role of food and environmental contaminants, especially EDCs and aflatoxins, in child growth and on the implications for metabolic dysfunction and disease risk in later life, and discuss potential applications of nuclear and isotopic techniques to elucidate the underlying biological mechanisms, outcome indicators, as well as occurrence levels.

  18. Growth of InAs Quantum Dots on Germanium Substrate Using Metal Organic Chemical Vapor Deposition Technique

    Directory of Open Access Journals (Sweden)

    Tyagi Renu

    2009-01-01

    Full Text Available Abstract Self-assembled InAs quantum dots (QDs were grown on germanium substrates by metal organic chemical vapor deposition technique. Effects of growth temperature and InAs coverage on the size, density, and height of quantum dots were investigated. Growth temperature was varied from 400 to 450 °C and InAs coverage was varied between 1.40 and 2.35 monolayers (MLs. The surface morphology and structural characteristics of the quantum dots analyzed by atomic force microscope revealed that the density of the InAs quantum dots first increased and then decreased with the amount of InAs coverage; whereas density decreased with increase in growth temperature. It was observed that the size and height of InAs quantum dots increased with increase in both temperature and InAs coverage. The density of QDs was effectively controlled by growth temperature and InAs coverage on GaAs buffer layer.

  19. Optical and electrical properties of ZrSe3 single crystals grown by chemical vapour transport technique

    International Nuclear Information System (INIS)

    Patel, Kaushik; Prajapati, Jagdish; Vaidya, Rajiv; Patel, S.G.

    2005-01-01

    Single crystals of the lamellar compound, ZrSe 3 , were grown by chemical vapour transport technique using iodine as a transporting agent. The grown crystals were characterized with the help of energy dispersive analysis by X-ray (EDAX), which gave confirmation about the stoichiometry. The optical band gap measurement of as grown crystals was carried out with the help of optical absorption spectra in the range 700-1450 nm. The indirect as well as direct band gap of ZrSe 3 were found to be 1.1 eV and 1.47 eV, respectively. The resistivity of the as grown crystals was measured using van der Pauw method. The Hall parameters of the grown crystals were determined at room temperature from Hall effect measurements. Electrical resistivity measurements were performed on this crystal in the temperature range 303-423 K. The crystals were found to exhibit semiconducting nature in this range. The activation energy and anisotropy measurements were carried out for this crystal. Pressure dependence of electrical resistance was studied using Bridgman opposed anvils set up up to 8 GPa. The semiconducting nature of ZrSe 3 single crystal was inferred from the graph of resistance vs pressure. The results obtained are discussed in detail. (author)

  20. A Comparative Study of Three Different Chemical Vapor Deposition Techniques of Carbon Nanotube Growth on Diamond Films

    Directory of Open Access Journals (Sweden)

    Betty T. Quinton

    2013-01-01

    Full Text Available This paper compares between the methods of growing carbon nanotubes (CNTs on diamond substrates and evaluates the quality of the CNTs and the interfacial strength. One potential application for these materials is a heat sink/spreader for high-power electronic devices. The CNTs and diamond substrates have a significantly higher specific thermal conductivity than traditional heat sink/spreader materials making them good replacement candidates. Only limited research has been performed on these CNT/diamond structures and their suitability of different growth methods. This study investigates three potential chemical vapor deposition (CVD techniques for growing CNTs on diamond: thermal CVD (T-CVD, microwave plasma-enhanced CVD (MPE-CVD, and floating catalyst thermal CVD (FCT-CVD. Scanning electron microscopy (SEM and high-resolution transmission electron microscopy (TEM were used to analyze the morphology and topology of the CNTs. Raman spectroscopy was used to assess the quality of the CNTs by determining the ID/IG peak intensity ratios. Additionally, the CNT/diamond samples were sonicated for qualitative comparisons of the durability of the CNT forests. T-CVD provided the largest diameter tubes, with catalysts residing mainly at the CNT/diamond interface. The MPE-CVD process yielded non uniform defective CNTs, and FCT-CVD resulted in the smallest diameter CNTs with catalyst particles imbedded throughout the length of the nanotubes.

  1. Application of industrial hygiene techniques for work-place exposure assessment protocols related to petro-chemical exploration and production field activities

    International Nuclear Information System (INIS)

    Koehn, J.

    1995-01-01

    Standard industrial hygiene techniques for recognition, evaluation, and control can be directly applied to development of technical protocols for workplace exposure assessment activities for a variety of field site locations. Categories of occupational hazards include chemical and physical agents. Examples of these types of hazards directly related to oil and gas exploration and production workplaces include hydrocarbons, benzene, oil mist, hydrogen sulfide, Naturally Occurring Radioactive Materials (NORM), asbestos-containing materials, and noise. Specific components of well process chemicals include potential hazardous chemical substances such as methanol, acrolein, chlorine dioxide, and hydrochloric acid. Other types of exposure hazards may result from non-routine conduct of sandblasting and painting operations

  2. Modern sample preparation techniques for gas chromatography-mass spectrometry analysis of environmental markers of chemical warfare agents use

    NARCIS (Netherlands)

    Terzic, O.; de Voogt, P.; Banoub, J.

    2014-01-01

    The chapter introduces problematics of on-site chemical analysis in the investigations of past chemical warfare agents (CWA) events. An overview of primary environmental degradation pathways of CWA leading to formation of chemical markers of their use is given. Conventional and modern sample

  3. The Combination of DGT Technique and Traditional Chemical Methods for Evaluation of Cadmium Bioavailability in Contaminated Soils with Organic Amendment

    Directory of Open Access Journals (Sweden)

    Yu Yao

    2016-06-01

    Full Text Available Organic amendments have been proposed as a means of remediation for Cd-contaminated soils. However, understanding the inhibitory effects of organic materials on metal immobilization requires further research. In this study colza cake, a typical organic amendment material, was investigated in order to elucidate the ability of this material to reduce toxicity of Cd-contaminated soil. Available concentrations of Cd in soils were measured using an in situ diffusive gradients in thin films (DGT technique in combination with traditional chemical methods, such as HOAc (aqua regia, EDTA (ethylene diamine tetraacetic acid, NaOAc (sodium acetate, CaCl2, and labile Cd in pore water. These results were applied to predict the Cd bioavailability after the addition of colza cake to Cd-contaminated soil. Two commonly grown cash crops, wheat and maize, were selected for Cd accumulation studies, and were found to be sensitive to Cd bioavailability. Results showed that the addition of colza cake may inhibit the growth of wheat and maize. Furthermore, the addition of increasing colza cake doses led to decreasing shoot and root biomass accumulation. However, increasing colza cake doses did lead to the reduction of Cd accumulation in plant tissues, as indicated by the decreasing Cd concentrations in shoots and roots. The labile concentration of Cd obtained by DGT measurements and the traditional chemical extraction methods, showed the clear decrease of Cd with the addition of increasing colza cake doses. All indicators showed significant positive correlations (p < 0.01 with the accumulation of Cd in plant tissues, however, all of the methods could not reflect plant growth status. Additionally, the capability of Cd to change from solid phase to become available in a soil solution decreased with increasing colza cake doses. This was reflected by the decreases in the ratio (R value of CDGT to Csol. Our study suggests that the sharp decrease in R values could not only

  4. Transfer RNA species in human lymphocytes stimulated by mitogens and in leukemic cells. [/sup 3/H, /sup 14/C, /sup 32/P tracer techniques

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, G.D.; Yang, W.K.; Novelli, G.D.

    1976-01-01

    Transfer ribonucleic acid (tRNA) profiles in human lymphocytes stimulated by various mitogens have been compared with profiles from nonstimulated cells and from leukemic cells using reversed-phase chromatography. Comparisons of (/sup 3/H)- or (/sup 11/C)uridine- or (/sup 32/P)phosphate-labeled tRNAs showed that the greatest changes in tRNA composition upon phytohemagglutinin (PHA) stimulation occurred in the first 8 h after mitogen addition. Stimulation of lymphocytes by pokeweed mitogen, anti-human immunoglobulin, or bacterial lipopolysaccharide resulted in tRNA species which showed distinct differences from each other and also from the tRNAs produced by phytohemagglutinin stimulation. Leukemic lymphocyte tRNAs showed the most extensive differences in profile when compared with chromatograms from non-neoplastic cells stimulated by a variety of mitogens. Specific isoaccepting species of tyrosyl-, aspartyl-, and phenylalanyl-tRNAs were also compared in PHA-stimulated and resting lymphocytes and no differences were found. When these same species were studied in leukemic cells, tyrosyl-tRNA profiles were shifted to elute at a lower salt concentration, while the aspartyl-tRNA profile showed a new peak not present in noncancerous cells.

  5. Thyroid stimulating hormone levels in newborns and early life exposure to endocrine disrupting chemicals - analysis of three European mother-child cohorts

    NARCIS (Netherlands)

    de Cock, Marijke; de Boer, Michiel R; Govarts, Eva; Iszatt, Nina; Palkovicova, Lubica; Lamoree, Marja H; Schoeters, Greet; Eggesbø, Merete; Trnovec, Tomas; Legler, Juliette; van de Bor, Margot

    2017-01-01

    BACKGROUND: Various studies report interactions between thyroid hormones and early life chemical exposure. Our objective was to analyse associations between markers of endocrine disrupting chemical exposure and thyroid function in newborns, determined in heel prick blood spots. METHODS: Three

  6. Determination of Methylmercury Traces in Biological Matrix: Chemical Extraction and Nuclear Quantification with the Neutron Activation Analysis Technique

    International Nuclear Information System (INIS)

    Soldati, A.L.

    2002-01-01

    Mercury is present in the environment as a result of the human and natural activities.The total amount of Hg present in the biosphere has been incremented three times since the industrial era, and now it is affecting in a global sense all the ecosystem.One of the main entrance of Hg in the human diet is the consumption of fish and other marine creatures.Most of the ingested Hg is mono methylmercury (MeHg), which is one of the most toxic forms in which this element could be found because it crosses membranes.Since the toxicity levels are low, the determination of concentrations of total Hg and Me Hg require very careful sampling, sample conditioning and analytical procedures to prevent either losses or contamination, or the degradation of the Hg species.In this work, we implemented a chemical Me Hg extraction procedure, using a ionic exchange resin, with three different types of fish tissue: muscle, liver and hepato pancreas.After Me Hg extraction, the determination and quantification was made by Instrumental Neutron Activation Analysis, by measuring the 197 Au, y el 203 Tl deexcitation s, created through the radioactive decay of the isotopes 197 Hg y 203 Hg.The influence of several parameters on the overall extraction process, such as velocity of passage through the ionic exchange column and the acid concentration used in the extraction was evaluated.Regarding the INAA determinations, a choice was made for the irradiation, decay and counting times, neutron and gamma doses, and the counting geometry The detection limit found for this technique (dry weight) is 140 pg MeHg/g. The Hg contents of the muscle samples were measured with the 279 keV emission of the product of the 202 Hg(n,g) 203 Hg reaction, with a recovery of (100 ± 13)%. Liver and Hepato pancreas samples were measured with the 77 keV gamma emission of the 197 Hg, checking this result with the 67 y 69 keV X emissions from the same isotope.The liver samples needed an extra vacuum filtering process during

  7. Construction of a technique plan repository and evaluation system based on AHP group decision-making for emergency treatment and disposal in chemical pollution accidents.

    Science.gov (United States)

    Shi, Shenggang; Cao, Jingcan; Feng, Li; Liang, Wenyan; Zhang, Liqiu

    2014-07-15

    The environmental pollution resulting from chemical accidents has caused increasingly serious concerns. Therefore, it is very important to be able to determine in advance the appropriate emergency treatment and disposal technology for different types of chemical accidents. However, the formulation of an emergency plan for chemical pollution accidents is considerably difficult due to the substantial uncertainty and complexity of such accidents. This paper explains how the event tree method was used to create 54 different scenarios for chemical pollution accidents, based on the polluted medium, dangerous characteristics and properties of chemicals involved. For each type of chemical accident, feasible emergency treatment and disposal technology schemes were established, considering the areas of pollution source control, pollutant non-proliferation, contaminant elimination and waste disposal. Meanwhile, in order to obtain the optimum emergency disposal technology schemes as soon as the chemical pollution accident occurs from the plan repository, the technique evaluation index system was developed based on group decision-improved analytical hierarchy process (AHP), and has been tested by using a sudden aniline pollution accident that occurred in a river in December 2012. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Effects of Jigsaw Cooperative Learning and Animation Techniques on Students' Understanding of Chemical Bonding and Their Conceptions of the Particulate Nature of Matter

    Science.gov (United States)

    Karacop, Ataman; Doymus, Kemal

    2013-04-01

    The aim of this study was to determine the effect of jigsaw cooperative learning and computer animation techniques on academic achievements of first year university students attending classes in which the unit of chemical bonding is taught within the general chemistry course and these students' learning of the particulate nature of matter of this unit. The sample of this study consisted of 115 first-year science education students who attended the classes in which the unit of chemical bonding was taught in a university faculty of education during the 2009-2010 academic year. The data collection instruments used were the Test of Scientific Reasoning, the Purdue Spatial Visualization Test: Rotations, the Chemical Bonding Academic Achievement Test, and the Particulate Nature of Matter Test in Chemical Bonding (CbPNMT). The study was carried out in three different groups. One of the groups was randomly assigned to the jigsaw group, the second was assigned to the animation group (AG), and the third was assigned to the control group, in which the traditional teaching method was applied. The data obtained with the instruments were evaluated using descriptive statistics, one-way ANOVA, and MANCOVA. The results indicate that the teaching of chemical bonding via the animation and jigsaw techniques was more effective than the traditional teaching method in increasing academic achievement. In addition, according to findings from the CbPNMT, the students from the AG were more successful in terms of correct understanding of the particulate nature of matter.

  9. Impacts of fire, fire-fighting chemicals and post-fire stabilization techniques on the soil-plant system

    OpenAIRE

    Fernández Fernández, María

    2017-01-01

    Forest fires, as well as fire-fighting chemicals, greatly affect the soil-plant system causing vegetation loss, alterations of soil properties and nutrient losses through volatilization, leaching and erosion. Soil recovery after fires depends on the regeneration of the vegetation cover, which protects the soil and prevents erosion. Fire-fighting chemicals contain compounds potentially toxic for plants and soil organisms, and thus their use might hamper the regeneration of burnt ecosystems. In...

  10. Morphology-controlled SWCNT/polymeric microsphere arrays by a wet chemical self-assembly technique and their application for sensors

    International Nuclear Information System (INIS)

    Huang Xingjiu; Li Yue; Im, Hyung-Soon; Yarimaga, Oktay; Kim, Ju-Hyun; Jang, Doon-Yoon; Cho, Sung-Oh; Cai Weiping; Choi, Yang-Kyu

    2006-01-01

    Large-scale morphology-controlled SWCNT/polymeric microsphere arrays can be obtained by a wet chemical self-assembly technique. The loading of SWCNTs, the length of SWCNTs, and the size and nature of polymeric microspheres can easily be controlled. Similar results can also be reached using this method for MWCNTs. In both types of CNTs, they form an interesting interactive 'net' structure on spheres and sphere joints. The SWCNT/PS-modified Au electrode was used for detection of uric acid by cyclic voltammetry and single-potential time-based techniques. The preliminary results show that the modified electrode presents good sensitivity and stability to uric acid

  11. Dependence between fusion temperatures and chemical components of a certain type of coal using classical, non-parametric and bootstrap techniques

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Manteiga, W.; Prada-Sanchez, J.M.; Fiestras-Janeiro, M.G.; Garcia-Jurado, I. (Universidad de Santiago de Compostela, Santiago de Compostela (Spain). Dept. de Estadistica e Investigacion Operativa)

    1990-11-01

    A statistical study of the dependence between various critical fusion temperatures of a certain kind of coal and its chemical components is carried out. As well as using classical dependence techniques (multiple, stepwise and PLS regression, principal components, canonical correlation, etc.) together with the corresponding inference on the parameters of interest, non-parametric regression and bootstrap inference are also performed. 11 refs., 3 figs., 8 tabs.

  12. Chemical and biological evaluation of the nutritive value of Algerian green seaweed Ulva lactuca using in vitro gas production technique fior ruminant animals

    OpenAIRE

    Zitouni, Hind; Arhab, Rabah; Boudry, Christelle; Bousseboua, Hacène; Beckers, Yves

    2014-01-01

    This study aimed to determine the nutritive value of seaweed Ulva lactuca collected from the Algerian coast by estimation of its chemical composition and fermentation characteristics, comparatively to vetch-oat hay (control), using in vitro gas production technique. Seaweed and control were incubated with rumen liquor taken from fistulated and non lactating cows. Gas production was recorded at: 2, 4, 6, 8, 12, 24, 48 and 72h. The in vitro rumen fermentation parameters were measured after 24h ...

  13. Analysis of High Quality Agar wood Oil Chemical Compounds By Means Of SPME/ GC-MS and Z-Score Technique

    International Nuclear Information System (INIS)

    Nurlaila Ismail; Mohd Ali Nor Azah; Mailina Jamil; Saiful Nizam Tajuddin; Mohd Nasir Taib

    2013-01-01

    Currently, the grading of the agar wood oil to the high and low quality is done using manually such as human trained grader. It was performed based on the agar wood oil physical properties such as human experience and perception and the oil colour, odor and long lasting aroma. Several researchers found that chemical profiles of the oil should be utilized to overcome the problem facing by manual techniques for example human nose cannot tolerate with the many oils at the same time, so that accurate result can be obtained in grading the agar wood oil. The analysis involved of SPME/ GC-MS and Z-score techniques have been proposed in this study to analyze the chemical compounds especially from the high quality samples of agar wood oil (Aquilariamalaccensis) from Malaysia. Two SPME fibers were used such as divinylbenzene-carbogen-polydimethylsiloxane (DVB-CAR-PDMS) and polydimethylsiloxane (PDMS) in extracting the oils compound under three different sampling temperature conditions such as 40, 60 and 80 degree Celsius. The chemical compounds extracted by SPME/ GC-MS were analyzed. The chemical compounds as identified by Z-score as significant compounds were discussed before the conclusion is made. It was found that 10-epi-γ-eudesmol, aromadendrene, β-agar ofuran, α-agar ofuran and γ-eudesmol were highlighted as significant for high quality agar wood oil and can be used as a marker compounds in classifying the agar wood oil. (author)

  14. Combination of chemical suppression techniques for dual suppression of fat and silicone at diffusion-weighted MR imaging in women with breast implants

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Dow-Mu; Hughes, J. [Royal Marsden Hospital, Department of Radiology, Sutton (United Kingdom); Blackledge, M.; Leach, M.O.; Collins, D.J. [Institute of Cancer Research, CR UK-EPSRC Cancer Imaging Centre, Sutton (United Kingdom); Burns, S. [Nuada 3T MRI Centre, London (United Kingdom); Stemmer, A.; Kiefer, B. [Siemens Healthcare, Erlangen (Germany)

    2012-12-15

    Silicone breast prostheses prove technically challenging when performing diffusion-weighted MR imaging in the breasts. We describe a combined fat and chemical suppression scheme to achieve dual suppression of fat and silicone, thereby improving the quality of diffusion-weighted images in women with breast implants. MR imaging was performed at 3.0 and 1.5 T in women with silicone breast implants using short-tau inversion recovery (STIR) fat-suppressed echo-planar (EPI) diffusion-weighted MR imaging (DWI) on its own and combined with the slice-select gradient-reversal (SSGR) technique. Imaging was performed using dedicated breast imaging coils. Complete suppression of the fat and silicone signal was possible at 3.0 T using EPI DWI with STIR and SSGR, evaluated with dedicated breast coils. However, a residual silicone signal was still perceptible at 1.5 T using this combined approach. Nevertheless, a further reduction in silicone signal at 1.5 T could be achieved by employing thinner slice partitions and the addition of the chemical-selective fat-suppression (CHESS) technique. DWI using combined STIR and SSGR chemical suppression techniques is feasible to eliminate or reduce silicone signal from prosthetic breast implants. (orig.)

  15. HIGHLY SELECTIVE SENSORS FOR CHEMICAL AND BIOLOGICAL WARFARE AGENTS, INSECTICIDES AND VOCS BASED ON A MOLECULAR SURFACE IMPRINTING TECHNIQUE

    Science.gov (United States)

    Abstract was given as an oral platform presentation at the Pittsburgh Conference, Orlando FL (March 5-9, 2006). Research described is the development of sensors based on molecular surface imprinting. Applications include the monitoring of chemical and biological agents and inse...

  16. Evaluation of the laser-induced breakdown spectroscopy technique for determination of the chemical composition of copper concentrates

    Energy Technology Data Exchange (ETDEWEB)

    Łazarek, Łukasz, E-mail: lukasz.lazarek@pwr.wroc.pl [Laser and Fiber Electronics Group, Faculty of Electronics, Wroclaw University of Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw (Poland); Antończak, Arkadiusz J.; Wójcik, Michał R. [Laser and Fiber Electronics Group, Faculty of Electronics, Wroclaw University of Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw (Poland); Drzymała, Jan [Faculty of Geoengineering, Mining and Geology, Wroclaw University of Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw (Poland); Abramski, Krzysztof M. [Laser and Fiber Electronics Group, Faculty of Electronics, Wroclaw University of Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw (Poland)

    2014-07-01

    Laser-induced breakdown spectroscopy (LIBS), like many other spectroscopic techniques, is a comparative method. Typically, in qualitative analysis, synthetic certified standard with a well-known elemental composition is used to calibrate the system. Nevertheless, in all laser-induced techniques, such calibration can affect the accuracy through differences in the overall composition of the chosen standard. There are also some intermediate factors, which can cause imprecision in measurements, such as optical absorption, surface structure and thermal conductivity. In this work the calibration performed for the LIBS technique utilizes pellets made directly from the tested materials (old well-characterized samples). This choice produces a considerable improvement in the accuracy of the method. This technique was adopted for the determination of trace elements in industrial copper concentrates, standardized by conventional atomic absorption spectroscopy with a flame atomizer. A series of copper flotation concentrate samples was analyzed for three elements: silver, cobalt and vanadium. We also proposed a method of post-processing the measurement data to minimize matrix effects and permit reliable analysis. It has been shown that the described technique can be used in qualitative and quantitative analyses of complex inorganic materials, such as copper flotation concentrates. It was noted that the final validation of such methodology is limited mainly by the accuracy of the characterization of the standards. - Highlights: • A laser-induced breakdown spectroscopy technique is introduced for composition monitoring in industrial copper concentrates. • Calibration samples consisted of pellets produced from the tested materials. • The proposed method of post-processing significantly minimizes matrix effects. • The possible uses of this technique are limited mainly by accurate characterization of the standard samples.

  17. Evaluation of the laser-induced breakdown spectroscopy technique for determination of the chemical composition of copper concentrates

    International Nuclear Information System (INIS)

    Łazarek, Łukasz; Antończak, Arkadiusz J.; Wójcik, Michał R.; Drzymała, Jan; Abramski, Krzysztof M.

    2014-01-01

    Laser-induced breakdown spectroscopy (LIBS), like many other spectroscopic techniques, is a comparative method. Typically, in qualitative analysis, synthetic certified standard with a well-known elemental composition is used to calibrate the system. Nevertheless, in all laser-induced techniques, such calibration can affect the accuracy through differences in the overall composition of the chosen standard. There are also some intermediate factors, which can cause imprecision in measurements, such as optical absorption, surface structure and thermal conductivity. In this work the calibration performed for the LIBS technique utilizes pellets made directly from the tested materials (old well-characterized samples). This choice produces a considerable improvement in the accuracy of the method. This technique was adopted for the determination of trace elements in industrial copper concentrates, standardized by conventional atomic absorption spectroscopy with a flame atomizer. A series of copper flotation concentrate samples was analyzed for three elements: silver, cobalt and vanadium. We also proposed a method of post-processing the measurement data to minimize matrix effects and permit reliable analysis. It has been shown that the described technique can be used in qualitative and quantitative analyses of complex inorganic materials, such as copper flotation concentrates. It was noted that the final validation of such methodology is limited mainly by the accuracy of the characterization of the standards. - Highlights: • A laser-induced breakdown spectroscopy technique is introduced for composition monitoring in industrial copper concentrates. • Calibration samples consisted of pellets produced from the tested materials. • The proposed method of post-processing significantly minimizes matrix effects. • The possible uses of this technique are limited mainly by accurate characterization of the standard samples

  18. Concurrent reduction and distillation: an improved technique for the recovery and chemical refinement of the isotopes of cadmium and zinc

    International Nuclear Information System (INIS)

    Caudill, H.H.; McBride, L.E.; McDaniel, E.W.

    1982-01-01

    The Electromagnetic Isotope Separations Program of the Oak Ridge National Laboratory has been involved in the separation, chemical recovery, and refinement of the stable isotopes of cadmium and zinc since 1946. Traditionally, the chemical refinement procedures for these elements consisted of ion exchange separations using anion exchange resins followed by pH-controlled hydrogen sulfide precipitations. The procedures were quite time-consuming and made it difficult to remove trace quantities of sulfur which interferes in subsequent attempts to prepare rolled metal foils. As demands for 113 Cd and 68 Zn (a precursor for the production of the radiopharmaceutical 67 Ga) increased, it became evident that a quicker, more efficient refinement procedure was needed. Details of an improved method, which employs concurrent hydrogen reduction and distillation in the recovery and refinement of isotopically enriched zinc, are described. Modifications of the procedure suitable for the refinement of cadmium isotopes are also described. 3 figures, 1 table

  19. Evaluation of the laser-induced breakdown spectroscopy technique for determination of the chemical composition of copper concentrates

    Science.gov (United States)

    Łazarek, Łukasz; Antończak, Arkadiusz J.; Wójcik, Michał R.; Drzymała, Jan; Abramski, Krzysztof M.

    2014-07-01

    Laser-induced breakdown spectroscopy (LIBS), like many other spectroscopic techniques, is a comparative method. Typically, in qualitative analysis, synthetic certified standard with a well-known elemental composition is used to calibrate the system. Nevertheless, in all laser-induced techniques, such calibration can affect the accuracy through differences in the overall composition of the chosen standard. There are also some intermediate factors, which can cause imprecision in measurements, such as optical absorption, surface structure and thermal conductivity. In this work the calibration performed for the LIBS technique utilizes pellets made directly from the tested materials (old well-characterized samples). This choice produces a considerable improvement in the accuracy of the method. This technique was adopted for the determination of trace elements in industrial copper concentrates, standardized by conventional atomic absorption spectroscopy with a flame atomizer. A series of copper flotation concentrate samples was analyzed for three elements: silver, cobalt and vanadium. We also proposed a method of post-processing the measurement data to minimize matrix effects and permit reliable analysis. It has been shown that the described technique can be used in qualitative and quantitative analyses of complex inorganic materials, such as copper flotation concentrates. It was noted that the final validation of such methodology is limited mainly by the accuracy of the characterization of the standards.

  20. growth stimulant

    African Journals Online (AJOL)

    Effects of timing and duration of supplementation of LIVFIT VET ® (growth stimulant) as substitute for fish meal on the growth performance, haematology and clinical enzymes concentration of growing pigs.

  1. Noninvasive Transcranial Brain Stimulation and Pain

    OpenAIRE

    Rosen, Allyson C.; Ramkumar, Mukund; Nguyen, Tam; Hoeft, Fumiko

    2009-01-01

    Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) are two noninvasive brain stimulation techniques that can modulate activity in specific regions of the cortex. At this point, their use in brain stimulation is primarily investigational; however, there is clear evidence that these tools can reduce pain and modify neurophysiologic correlates of the pain experience. TMS has also been used to predict response to surgically implanted stimulation for the tre...

  2. Chemical vs. electrochemical extraction of lithium from the Li-excess Li(1.10)Mn(1.90)O4 spinel followed by NMR and DRX techniques.

    Science.gov (United States)

    Martinez, S; Sobrados, I; Tonti, D; Amarilla, J M; Sanz, J

    2014-02-21

    Lithium extraction from the Li-excess Li1.10Mn1.90O4 spinel has been performed by chemical and electrochemical methods in aqueous and in organic media, respectively. De-lithiated samples have been investigated by XRD, SEM, TG, (7)Li and (1)H MAS-NMR techniques. The comparative study has allowed demonstrating that the intermediate de-intercalated samples prepared during the chemical extraction by acid titration are similar to those prepared by the electrochemical way in a non-aqueous electrolyte. LiMn2O4 based spinel with a tailored de-lithiation degree can be prepared as a single phase by controlling the pH used in chemical extraction. (7)Li MAS-NMR spectroscopy has been used to follow the influence of the manganese oxidation state on tetra and octahedral Li-signals detected in Li-extracted samples. The oxidation of Mn(III) ions goes parallel to the partial dissolution of the spinel, following Hunter's mechanism. Based on this mechanism, a generalized chemical reaction has been proposed to explain the formation of intermediate Li(+) de-intercalated samples during acid treatment in aqueous media. By the (1)H MAS NMR study, no evidence of Li-H topotactic exchange in the bulk of the acid treated material was found.

  3. Environmental monitoring of selected pesticides and organic chemicals in urban stormwater recycling systems using passive sampling techniques.

    Science.gov (United States)

    Page, Declan; Miotliński, Konrad; Gonzalez, Dennis; Barry, Karen; Dillon, Peter; Gallen, Christie

    2014-03-01

    Water recycling via aquifers has become a valuable tool to augment urban water supplies in many countries. This study reports the first use of passive samplers for monitoring of organic micropollutants in Managed Aquifer Recharge (MAR). Five different configurations of passive samplers were deployed in a stormwater treatment wetland, groundwater monitoring wells and a recovery tank to capture a range of polar and non-polar micropollutants present in the system. The passive samplers were analysed for a suite of pesticides, polycyclic aromatic hydrocarbons (PAHs) and other chemicals. As a result, 17 pesticides and pesticide degradation products, 5 PAHs and 8 other organic chemicals including flame retardants and fragrances were detected in urban stormwater recharging Aquifer Storage and Recovery (ASR) and an Aquifer Storage Transfer and Recovery (ASTR) system. Of the pesticides detected, diuron, metolachlor and chlorpyrifos were generally detected at the highest concentrations in one or more passive samplers, whereas chlorpyrifos, diuron, metolachlor, simazine, galaxolide and triallate were detected in multiple samplers. Fluorene was the PAH detected at the highest concentration and the flame retardant Tris(1-chloro-2-propyl)phosphate was the chemical detected in the greatest abundance at all sites. The passive samplers showed different efficiencies for capture of micropollutants with the Empore disc samplers giving the most reliable results. The results indicate generally low levels of organic micropollutants in the stormwater, as the contaminants detected were present at very low ng/L levels, generally two to four orders of magnitude below the drinking water guidelines (NHMRC, 2011). The efficiency of attenuation of these organic micropollutants during MAR was difficult to determine due to variations in the source water concentrations. Comparisons were made between different samplers, to give a field-based calibration where existing lab-based calibrations were

  4. Chemical imaging techniques for the analysis of complex mixtures: New application to the characterization of ritual matters on African wooden statuettes

    International Nuclear Information System (INIS)

    Mazel, Vincent; Richardin, Pascale; Touboul, David; Brunelle, Alain; Walter, Philippe; Laprevote, Olivier

    2006-01-01

    Chemical imaging techniques, based on the combination of microscopy and spectroscopy, are well suited to study both the composition and the spatial organization of heterogeneous complex mixtures of organic and mineral matter. Time-of-flight secondary ion mass spectrometry (ToF-SIMS), followed by scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX) and Fourier transform infrared microscopy (FTIR microscopy) have been applied to non-destructive analysis of micro-samplings of ritual matters deposited on the surface of African wooden statuettes. With a very careful preparation, using ultramicrotomy on embedded samples, it was possible to perform successively all the measurements on a single fragment. Comparison and superposition of the different chemical images, obtained on a sample from a significant actual artefact, have allowed us to identify minerals (clays, quartz and calcium carbonate), proteins, starch, urate salts and lipids and to map their spatial distribution

  5. Study of the Chemical Mechanism Involved in the Formation of Tungstite in Benzyl Alcohol by the Advanced QEXAFS Technique

    DEFF Research Database (Denmark)

    Olliges‐Stadler, Inga; Stötzel, Jan; Koziej, Dorota

    2012-01-01

    Insight into the complex chemical mechanism for the formation of tungstite nanoparticles obtained by the reaction of tungsten hexachloride with benzyl alcohol is presented herein. The organic and inorganic species involved in the formation of the nanoparticles were studied by time‐dependent gas......‐scanning extended X‐ray absorption fine structure spectroscopy enabled the time‐dependent evolution of the starting compound, the intermediates and the product to be monitored over the full reaction period. The reaction starts with fast chlorine substitution and partial reduction during the dissolution...

  6. Comparison of three aerosol chemical characterization techniques utilizing PTR-ToF-MS: a study on freshly formed and aged biogenic SOA

    Science.gov (United States)

    Gkatzelis, Georgios I.; Tillmann, Ralf; Hohaus, Thorsten; Müller, Markus; Eichler, Philipp; Xu, Kang-Ming; Schlag, Patrick; Schmitt, Sebastian H.; Wegener, Robert; Kaminski, Martin; Holzinger, Rupert; Wisthaler, Armin; Kiendler-Scharr, Astrid

    2018-03-01

    An intercomparison of different aerosol chemical characterization techniques has been performed as part of a chamber study of biogenic secondary organic aerosol (BSOA) formation and aging at the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction chamber). Three different aerosol sampling techniques - the aerosol collection module (ACM), the chemical analysis of aerosol online (CHARON) and the collection thermal-desorption unit (TD) were connected to proton transfer reaction time-of-flight mass spectrometers (PTR-ToF-MSs) to provide chemical characterization of the SOA. The techniques were compared among each other and to results from an aerosol mass spectrometer (AMS) and a scanning mobility particle sizer (SMPS). The experiments investigated SOA formation from the ozonolysis of β-pinene, limonene, a β-pinene-limonene mix and real plant emissions from Pinus sylvestris L. (Scots pine). The SOA was subsequently aged by photo-oxidation, except for limonene SOA, which was aged by NO3 oxidation. Despite significant differences in the aerosol collection and desorption methods of the PTR-based techniques, the determined chemical composition, i.e. the same major contributing signals, was found by all instruments for the different chemical systems studied. These signals could be attributed to known products expected from the oxidation of the examined monoterpenes. The sampling and desorption method of ACM and TD provided additional information on the volatility of individual compounds and showed relatively good agreement. Averaged over all experiments, the total aerosol mass recovery compared to an SMPS varied within 80 ± 10, 51 ± 5 and 27 ± 3 % for CHARON, ACM and TD, respectively. Comparison to the oxygen-to-carbon ratios (O : C) obtained by AMS showed that all PTR-based techniques observed lower O : C ratios, indicating a loss of molecular oxygen either during aerosol sampling or detection. The differences in total

  7. Comparison of three aerosol chemical characterization techniques utilizing PTR-ToF-MS: a study on freshly formed and aged biogenic SOA

    Directory of Open Access Journals (Sweden)

    G. I. Gkatzelis

    2018-03-01

    Full Text Available An intercomparison of different aerosol chemical characterization techniques has been performed as part of a chamber study of biogenic secondary organic aerosol (BSOA formation and aging at the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction chamber. Three different aerosol sampling techniques – the aerosol collection module (ACM, the chemical analysis of aerosol online (CHARON and the collection thermal-desorption unit (TD were connected to proton transfer reaction time-of-flight mass spectrometers (PTR-ToF-MSs to provide chemical characterization of the SOA. The techniques were compared among each other and to results from an aerosol mass spectrometer (AMS and a scanning mobility particle sizer (SMPS. The experiments investigated SOA formation from the ozonolysis of β-pinene, limonene, a β-pinene–limonene mix and real plant emissions from Pinus sylvestris L. (Scots pine. The SOA was subsequently aged by photo-oxidation, except for limonene SOA, which was aged by NO3 oxidation. Despite significant differences in the aerosol collection and desorption methods of the PTR-based techniques, the determined chemical composition, i.e. the same major contributing signals, was found by all instruments for the different chemical systems studied. These signals could be attributed to known products expected from the oxidation of the examined monoterpenes. The sampling and desorption method of ACM and TD provided additional information on the volatility of individual compounds and showed relatively good agreement. Averaged over all experiments, the total aerosol mass recovery compared to an SMPS varied within 80 ± 10, 51 ± 5 and 27 ± 3 % for CHARON, ACM and TD, respectively. Comparison to the oxygen-to-carbon ratios (O : C obtained by AMS showed that all PTR-based techniques observed lower O : C ratios, indicating a loss of molecular oxygen either during aerosol sampling or

  8. Using non-invasive molecular spectroscopic techniques to detect unique aspects of protein Amide functional groups and chemical properties of modeled forage from different sourced-origins.

    Science.gov (United States)

    Ji, Cuiying; Zhang, Xuewei; Yu, Peiqiang

    2016-03-05

    The non-invasive molecular spectroscopic technique-FT/IR is capable to detect the molecular structure spectral features that are associated with biological, nutritional and biodegradation functions. However, to date, few researches have been conducted to use these non-invasive molecular spectroscopic techniques to study forage internal protein structures associated with biodegradation and biological functions. The objectives of this study were to detect unique aspects and association of protein Amide functional groups in terms of protein Amide I and II spectral profiles and chemical properties in the alfalfa forage (Medicago sativa L.) from different sourced-origins. In this study, alfalfa hay with two different origins was used as modeled forage for molecular structure and chemical property study. In each forage origin, five to seven sources were analyzed. The molecular spectral profiles were determined using FT/IR non-invasive molecular spectroscopy. The parameters of protein spectral profiles included functional groups of Amide I, Amide II and Amide I to II ratio. The results show that the modeled forage Amide I and Amide II were centered at 1653 cm(-1) and 1545 cm(-1), respectively. The Amide I spectral height and area intensities were from 0.02 to 0.03 and 2.67 to 3.36 AI, respectively. The Amide II spectral height and area intensities were from 0.01 to 0.02 and 0.71 to 0.93 AI, respectively. The Amide I to II spectral peak height and area ratios were from 1.86 to 1.88 and 3.68 to 3.79, respectively. Our results show that the non-invasive molecular spectroscopic techniques are capable to detect forage internal protein structure features which are associated with forage chemical properties. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Pipelines for New Chemicals: a strategy to create new value chains and stimulate innovation-based economic revival in Southern European countries.

    Science.gov (United States)

    Timmis, Kenneth; de Lorenzo, Victor; Verstraete, Willy; Garcia, Jose Luis; Ramos, Juan Luis; Santos, Helena; Economidis, Ioannis; Nogales, Balbina; Timmis, James Kenneth; Fonseca, César; Pruzzo, Carla; Karagouni, Amalia; Panopoulos, Nickolas; Dixon, Bernard

    2014-01-01

    Countries of Southern Europe are currently suffering from severe socio-economic pain resulting from high debt levels and austerity measures which constrain investment in innovation-based recovery strategies that are essential for entry into a long-term sustainable period of increasing employment and wealth creation. Young university-educated people are particularly innovative, and hence vital to the development of such strategies, but employment opportunities are poor and many are forced to seek employment that neither profits from their training nor satisfies their justified career expectations, or to emigrate. They are the 'lost generation'. A strategy is proposed here for the creation of Pipelines for New Chemicals, national centre-network partnerships for the discovery-synthesis of new chemicals obtained though harvesting new biological diversity, and their exploitation to develop new medicines, agrochemicals, materials, and other products and applications. The goal is to create new regional motors of economic growth and development, by harnessing the knowledge, motivation and innovation potential of the excellently educated young people of Europe to catalyse the development of new small, medium and large enterprises centred around novel chemicals, and the value chains that will evolve with them, and thereby develop a powerful sector of sustainable growth in employment and social and economic prosperity in Southern Europe. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  10. Laser-induced breakdown spectroscopy (LIBS) technique for the determination of the chemical composition of complex inorganic materials

    Science.gov (United States)

    Łazarek, Łukasz; Antończak, Arkadiusz J.; Wójcik, Michał R.; Kozioł, Paweł E.; Stepak, Bogusz; Abramski, Krzysztof M.

    2014-08-01

    Laser-induced breakdown spectroscopy (LIBS) is a fast, fully optical method, that needs little or no sample preparation. In this technique qualitative and quantitative analysis is based on comparison. The determination of composition is generally based on the construction of a calibration curve namely the LIBS signal versus the concentration of the analyte. Typically, to calibrate the system, certified reference materials with known elemental composition are used. Nevertheless, such samples due to differences in the overall composition with respect to the used complex inorganic materials can influence significantly on the accuracy. There are also some intermediate factors which can cause imprecision in measurements, such as optical absorption, surface structure, thermal conductivity etc. This paper presents the calibration procedure performed with especially prepared pellets from the tested materials, which composition was previously defined. We also proposed methods of post-processing which allowed for mitigation of the matrix effects and for a reliable and accurate analysis. This technique was implemented for determination of trace elements in industrial copper concentrates standardized by conventional atomic absorption spectroscopy with a flame atomizer. A series of copper flotation concentrate samples was analyzed for contents of three elements, that is silver, cobalt and vanadium. It has been shown that the described technique can be used to qualitative and quantitative analyses of complex inorganic materials, such as copper flotation concentrates.

  11. New York Canyon Stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Raemy, Bernard

    2012-06-21

    The New York Canyon Stimulation Project was to demonstrate the commercial application of Enhanced Geothermal System techniques in Buena Vista Valley area of Pershing County, Nevada. From October 2009 to early 2012, TGP Development Company aggressively implemented Phase I of Pre-Stimulation and Site/Wellbore readiness. This included: geological studies; water studies and analyses and procurement of initial permits for drilling. Oversubscription of water rights and lack of water needed for implementation of EGS were identified and remained primary obstacles. Despite extended efforts to find alternative solutions, the water supply circumstances could not be overcome and led TGP to determine a "No Go" decision and initiate project termination in April 2012.

  12. Chemical and canine analysis as complimentary techniques for the identification of active odors of the invasive fungus, Raffaelea lauricola.

    Science.gov (United States)

    Simon, Alison G; Mills, DeEtta K; Furton, Kenneth G

    2017-06-01

    Raffaelea lauricola, a fungus causing a vascular wilt (laurel wilt) in Lauraceae trees, was introduced into the United States in the early 2000s. It has devastated forests in the Southeast and has now moved into the commercial avocado groves in southern Florida. Trained detection canines are currently one of the few successful methods for early detection of pre-symptomatic diseased trees. In order to achieve the universal and frequent training required to have successful detection canines, it is desirable to create accessible, safe, and long-lasting training aids. However, identification of odorants and compounds is limited by several factors, including both the availability of chemicals and the need to present chemicals individually and in combination to detection canines. A method for the separation and identification of volatile organic compounds (VOCs) from environmental substances for the creation of such a canine training aid is presented here. Headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to identify the odors present in avocado trees infected with the R. lauricola phytopathogen. Twenty-eight compounds were detected using this method, with nine present in greater than 80% of samples. The majority of these compounds were not commercially available as standard reference materials, and a canine trial was designed to identify the active odors without the need of pure chemical compounds. To facilitate the creation of a canine training aid, the VOCs above R. lauricola were separated by venting a 0.53mm ID solgel-wax gas chromatography column to the atmosphere. Ten minute fractions of the odor profile were collected on cotton gauze in glass vials and presented to the detection canines in a series of field trials. The canines alerted to the VOCs from the vials that correspond to a portion of the chromatogram containing the most volatile species from R. lauricola. This innovative fractionation and collection

  13. Improving Chinese nursing students' communication skills by utilizing video-stimulated recall and role-play case scenarios to introduce them to the SBAR technique.

    Science.gov (United States)

    Wang, Weiwen; Liang, Zhan; Blazeck, Alice; Greene, Brian

    2015-07-01

    Effective communication among healthcare workers is critically important for patient safety and quality care. The purpose of this pilot study was to evaluate outcomes of a workshop designed to teach Chinese nursing students to use the Situation-Background-Assessment-Recommendation (SBAR) communication tool and examine their attitudes toward utilizing SBAR as a communication tool. A convenience sample of 18 master's degree nursing students at a Chinese university was introduced to SBAR through a workshop. The workshop combined the SBAR tool, video-stimulated recall and role-play case scenarios to illustrate potential positive and negative communication-related patient outcomes. Students completed a 12-item questionnaire before and after participating in the workshop. Four of the items examined the four elements of the SBAR tool (situation, background, assessment, recommendation, score range 0-20), and eight of the items evaluated students' self-perceived attitudes towards utilizing the SBAR tool in their clinical practice (score range 0-40). Pre- and post-workshop scores on the four elements of the SBAR tool demonstrate significant improvement in knowledge of SBAR (14.0±2.9 vs. 16.6±2.2, respectively; p=0.009). Pre- and post-workshop scores on the items testing students' self-perceived abilities also demonstrate significant improvement (26.9±3.5 vs. 32.6±4.5, respectively; p<0.01) in using SBAR. Total scores increased significantly from 40.9±5.0 to 49.2±5.9 (p<0.01). Moreover, 93.8% of the students agreed and strongly agreed that they would use SBAR during clinical practice. Participating in the SBAR workshop in combination with video-stimulated recall and role-play case scenarios significantly improved the Chinese nursing students' knowledge of SBAR and their self-perceived attitudes towards using SBAR tool. Future studies using a larger sample size and longer post-workshop follow-up are needed to confirm the long-term benefits of the workshop. Copyright

  14. Application of the thermoluminescent (TL) and optically stimulated luminescence (OSL) dosimetry techniques to determinate the isodose curves in a cancer treatment planning simulation using Volumetric Modulated Arc Therapy - VMAT

    International Nuclear Information System (INIS)

    Bravim, Amanda

    2015-01-01

    The Volumetric Modulated Arc Therapy (VMAT) is an advance technique of Intensity Modulated Radiation Therapy (IMRT). This progress is due to the continuous gantry rotation with the radiation beam modulation providing lower time of the patient treatment. This research aimed the verification of the isodose curves in a simulation of a vertebra treatment with spinal cord protection using the thermoluminescent (TL) and optically stimulated luminescence (OSL) dosimetry techniques and the LiF:Mg,Ti (TLD-100), CaS0 4 :Dy and Al 2 0 3 :C dosimeters and LiF:Mg,Ti micro dosimeters (TLD-100). The dosimeters were characterized using PMMA plates of 30 x 30 x 30 cm 3 and different thickness. All irradiations were done using Truebeam STx linear accelerator of Hospital Israelita Albert Einstein, with 6 MV photons beam. After the dosimeter characterization, they were irradiated according the specific planning simulation and using a PMMA phantom developed to VMAT measurements. This irradiation aimed to verify the isodose curves of the treatment simulation using the two dosimetry techniques. All types of dosimeters showed satisfactory results to determine the dose distribution but analysing the complexity of the isodose curves and the proximity of them, the LiF:Mg,Ti micro dosimeter showed the most appropriate for use due to its small dimensions. Regarding the best technique, as both technique showed satisfactory results, the TL technique presents less complex to be used because the most of the radiotherapy departments already have a TL laboratory. The OSL technique requires more care and greater investment in the hospital. (author)

  15. Chemical characterization of particulate material at Piracicaba and Atibaia rivers, SP, Brazil, through X-ray fluorescence technique

    International Nuclear Information System (INIS)

    Valencia, Edwin Pastor Espinoza; Nascimento Filho, Virgilio F.; Sao Paulo Univ., Piracicaba, SP

    2000-01-01

    Samples of the particulate materials from Piracicaba and Atibaia rivers were collected on the period form winter(dry period) to summer(wet period) of 1996, at locations on the Piracicaba river bay, SP, by using cellulose acetate membrane of 0.45μm of pore diameter. The analysis have been done by using the energy dispersion instrumental x-ray fluorescence technique, activating those samples with x-ray tubes (target of Mo and filter of Zr on 25 kV - 20 mA) and quantifying the elements K, Ca, Ti, Mn, Cr, Fe, Ni, Cu and Zn by film methodology

  16. Improved techniques for outgoing wave variational principle calculations of converged state-to-state transition probabilities for chemical reactions

    Science.gov (United States)

    Mielke, Steven L.; Truhlar, Donald G.; Schwenke, David W.

    1991-01-01

    Improved techniques and well-optimized basis sets are presented for application of the outgoing wave variational principle to calculate converged quantum mechanical reaction probabilities. They are illustrated with calculations for the reactions D + H2 yields HD + H with total angular momentum J = 3 and F + H2 yields HF + H with J = 0 and 3. The optimization involves the choice of distortion potential, the grid for calculating half-integrated Green's functions, the placement, width, and number of primitive distributed Gaussians, and the computationally most efficient partition between dynamically adapted and primitive basis functions. Benchmark calculations with 224-1064 channels are presented.

  17. Comparison between neurostimulation techniques repetitive transcranial magnetic stimulation vs electroconvulsive therapy for the treatment of resistant depression: patient preference and cost-effectiveness.

    Science.gov (United States)

    Magnezi, Racheli; Aminov, Emanuel; Shmuel, Dikla; Dreifuss, Merav; Dannon, Pinhas

    2016-01-01

    Major depressive disorder (MDD) is a common disorder, widely distributed in the population, and is often associated with severe symptoms and functional impairment. It has been estimated that 30% of MDD patients do not benefit adequately from therapeutic interventions, including pharmacotherapy and psychotherapy. Treatment-resistant depression (TRD) is generally defined as a failure to achieve remission, despite therapeutic interventions. The most effective treatment alternatives for TRD are hospitalization, electroconvulsive therapy (ECT), and transcranial magnetic stimulation (TMS). Here we compared the clinical effectiveness of ECT and TMS, including success rates, patient responses, side-effect profiles, and financial worthiness. We found that ECT (P<0.0001) was more effective than TMS (P<0.012) (not statistically significant in group effect) in TRD patients. However, ECT patients reported a higher percentage of side effects (P<0.01) and the TMS treatment scored better in terms of patient preference. The cost benefit of ECT was higher than that of TMS (US$2075 vs US$814). Patient's preferences for treatment could be more intense in the TMS, if the TMS is included in the Health Maintenance Organization's service list. We propose that both of these treatment options should be available in psychiatric wards, thus expanding the therapeutic toolkit for TRD.

  18. Determination of Ni{sup 2+} using an equilibrium ion exchange technique: Important chemical factors and applicability to environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Worms, Isabelle A.M. [CABE - Analytical and Biophysical Environmental Chemistry, University of Geneva, 30 quai Ernest Ansermet 1211 Geneva 4 (Switzerland); Wilkinson, Kevin J. [Department of Chemistry, University of Montreal C.P. 6128, succursale Centre-ville Montreal, H3C 3J7 (Canada)], E-mail: KJ.Wilkinson@umontreal.ca

    2008-05-26

    In natural waters, the determination of free metal concentrations is a key parameter for studying bioavailability. Unfortunately, few analytical tools are available for determining Ni speciation at the low concentrations found in natural waters. In this paper, an ion exchange technique (IET) that employs a Dowex resin is evaluated for its applicability to measure [Ni{sup 2+}] in freshwaters. The presence of major cations (e.g. Na, Ca and Mg) reduced both the times that were required for equilibration and the partition coefficient to the resin ({lambda}{sup '}{sub Ni}). IET measurements of [Ni{sup 2+}] in the presence of known ligands (citrate, diglycolate, sulfoxine, oxine and diethyldithiocarbamate) were verified by thermodynamic speciation models (MINEQL{sup +} and VisualMINTEQ). Results indicated that the presence of hydrophobic complexes (e.g. Ni(DDC){sub 2}{sup 0}) lead to an overestimation of the Ni{sup 2+} fraction. On the other hand, [Ni{sup 2+}] measurements that were made in the presence of amphiphilic complexes formed with humic substances (standard aquatic humic acid (SRHA) and standard aquatic fulvic acid (SRFA)) were well correlated to free ion concentrations that were calculated using a NICA-DONNAN model. An analytical method is also presented here to reduce the complexity of the calibration (due to the presence of many other cations) for the use of Dowex equilibrium ion exchange technique in natural waters.

  19. Synthesis and self-assembly of dumbbell shaped ZnO sub-micron structures using low temperature chemical bath deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Borade, P. [National Centre for Nanoscience and Nanotechnology, University of Mumbai, Kalina Campus, Santacruz (E), Mumbai 400098 (India); Joshi, K.U. [Anton-Paar India Pvt. Ltd., Thane (W), 400607 (India); Gokarna, A.; Lerondel, G. [Laboratoire de Nanotechnologie et D' Instrumentation Optique, Institut Charles Delaunay, CNRS UMR 6281, Université de Technologie de Troyes, 12 Rue Marie Curie, BP 2060, 10010 Troyes (France); Walke, P. [National Centre for Nanoscience and Nanotechnology, University of Mumbai, Kalina Campus, Santacruz (E), Mumbai 400098 (India); Late, D. [National Chemical Laboratory (NCL), Pune 400027 (India); Jejurikar, S.M., E-mail: jejusuhas@gmail.com [National Centre for Nanoscience and Nanotechnology, University of Mumbai, Kalina Campus, Santacruz (E), Mumbai 400098 (India)

    2016-02-01

    We report well dispersed horizontal growth of ZnO sub-micron structures using simplest technique ever known i.e. chemical bath deposition (CBD). A set of samples were prepared under two different cases A) dumbbell shaped ZnO grown in CBD bath and B) tubular ZnO structures evolved from dumbbell shaped structures by dissolution mechanism. Single phase wurtzite ZnO formation is confirmed using X-ray diffraction (XRD) technique in both cases. From the morphological investigations performed using scanning electron microscopy (SEM), sample prepared under case A indicate formation of hex bit tool (HBT) shaped ZnO crystals, which observed to self-organize to form dumbbell structures. Further these microstructures are then converted into tubular structures as a fragment of post CBD process. The possible mechanism responsible for the self-assembly of HBT units to form dumbbell structures is discussed. Observed free excitonic peak located at 370 nm in photoluminescence (PL) spectra recorded at 18 K indicate that the micro/nanostructures synthesized using CBD are of high optical quality. - Highlights: • Controlled growth of Dumbbell shaped ZnO using Chemical Bath Deposition (CBD). • Growth mechanism of dumbbell shaped ZnO by self-assembling was discussed. • Quick Transformation of ZnO dumbbell structures in to tubular structures by dissolution. • Sharp UV Emission at 370 nm from both dumbbell and tubular structures.

  20. Thermally stimulated nonlinear refraction in gelatin stabilized Cu-PVP nanocomposite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Tamgadge, Y. S., E-mail: ystamgadge@gmail.com; Atkare, D. V. [Department of Physics, Mahatma Fule Arts, Commerce & SitaramjiChoudhari Science College, Warud, Dist. Amravati (MS), India-444906 (India); Pahurkar, V. G.; Muley, G. G., E-mail: gajananggm@yahoo.co.in [Department of Physics, SantGadge Baba Amravati University, Amravati (MS), India-444602 (India); Talwatkar, S. S. [Department of Physics, D K Marathe and N G Acharya College, Chembur, Mumbai (MS), India-440071 (India); Sunatkari, A. L. [Department of Physics, Siddharth College of Arts, Science and Commerce, Fort, Mumbai (MS), India-440001 (India)

    2016-05-06

    This article illustrates investigations on thermally stimulated third order nonlinear refraction of Cu-PVP nanocomposite thin films. Cu nanoparticles have been synthesized using chemical reduction method and thin films in PVP matrix have been obtained using spin coating technique. Thin films have been characterized by X-ray diffraction (XRD) and Ultraviolet-visible (UV-vis) spectroscopyfor structural and linear optical studies. Third order nonlinear refraction studies have been performed using closed aperture z-scan technique under continuous wave (CW) He-Ne laser. Cu-PVP nanocomposites are found to exhibit strong nonlinear refractive index stimulated by thermal lensing effect.

  1. Mass Spectrometric Study of Some Fluoroquinolone Drugs Using Electron Ionization and Chemical Ionization Techniques in Combination With Semi-Empirical Calculations

    International Nuclear Information System (INIS)

    Abd EL Kareem, M.S.M.

    2013-01-01

    A mass spectrometer of the type QMS (SSQ710) is used to record the electron ionization mass spectra of some 6-fluoroquinolones molecules, namely: Norfloxacin, Pefloxacin, Ciprofloxacin and Levofloxacin.While the chemical ionization mass spectra of these compounds are recorded using Thermo Finnigan TRACE DSQ GC/MS system.In EI mass spectra, the relative intensities for the molecular ions [M] +. of the studied compounds and the prominent fragment ions are reported and discussed. Furthermore, fragmentation patterns for the four compounds have been suggested and discussed and the most important fragmentation processes such as [M-CO 2 ] +. , [M-C 2 H 4 N] + and [M-CO 2 -C 2 H 4 N] + are investigated.On the other hand, the chemical ionization (CI) mass spectra of the compounds have been recorded using methane as the reagent gas. These spectra are discussed in terms of the structure of the compounds, with particular reference to their conventional electron ionization mass spectra. The protonated molecules [M + H] + are more relatively intense than [M] +. ions in the recorded EI mass spectra indicating higher stability in the case of [M + H] + .Also, fragmentation patterns for the four compounds have been suggested and discussed (using chemical ionization technique) and the most important fragmentation processes such as [MH-CO 2 ] +. , [MH-C 2 H 4 N] + and [MH-H 2 O] + are investigated.

  2. Some Examples of Residence-Time Distribution Studies in Large-Scale Chemical Processes by Using Radiotracer Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Bullock, R. M.; Johnson, P.; Whiston, J. [Imperial Chemical Industries Ltd., Billingham, Co., Durham (United Kingdom)

    1967-06-15

    The application of radiotracers to determine flow patterns in chemical processes is discussed with particular reference to the derivation of design data from model reactors for translation to large-scale units, the study of operating efficiency and design attainment in established plant and the rapid identification of various types of process malfunction. The requirements governing the selection of tracers for various types of media are considered and an example is given of the testing of the behaviour of a typical tracer before use in a particular large-scale process operating at 250 atm and 200 Degree-Sign C. Information which may be derived from flow patterns is discussed including the determination of mixing parameters, gas hold-up in gas/liquid reactions and the detection of channelling and stagnant regions. Practical results and their interpretation are given in relation to an define hydroformylation reaction system, a process for the conversion of propylene to isopropanol, a moving bed catalyst system for the isomerization of xylenes and a three-stage gas-liquid reaction system. The use of mean residence-time data for the detection of leakage between reaction vessels and a heat interchanger system is given as an example of the identification of process malfunction. (author)

  3. Structural and optical studied of nano structured lead sulfide thin films prepared by the chemical bath deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Al Din, Nasser Saad, E-mail: nsaadaldin@yahoo.com; Hussain, Nabiha, E-mail: nabihahssin@yahoo.com [Damascus University Faculty of Science, Department of physics, Homs (Syrian Arab Republic); Jandow, Nidhal, E-mail: nidhaljandow@yahoo.com [Al –Mustansiriyah University, College of Education, Department of physics, Baghdad (Iraq)

    2016-07-25

    Lead (II) Sulfide PbS thin films were deposited on glass substrates at 25°C by chemical bath deposition (CBD) method. The structural properties of the films were studied as a function of the concentration of Thiourea (CS (NH{sub 2}){sub 2}) as Source of Sulfide and deposition time. The surface morphology of the films was characterized by X-ray diffraction and SEM. The obtained results showed that the as-deposited films Polycrystalline had cubic crystalline phase that belong to S.G: Fm3m. We found that they have preferred orientation [200]. Also the thickness of thin films decrease with deposition time after certain value and, it observed free sulfide had orthorhombic phase. Optical properties showed that the thin films have high transmission at visible range and low transmission at UV, IR range. The films of PbS have direct band gap (I.68 - 2.32 ev) at 300 K the values of band energy decreases with increases thickness of the Lead (II) Sulfide films.

  4. A simple method to deposit palladium doped SnO2 thin films using plasma enhanced chemical vapor deposition technique

    International Nuclear Information System (INIS)

    Kim, Young Soon; Wahab, Rizwan; Shin, Hyung-Shik; Ansari, S. G.; Ansari, Z. A.

    2010-01-01

    This work presents a simple method to deposit palladium doped tin oxide (SnO 2 ) thin films using modified plasma enhanced chemical vapor deposition as a function of deposition temperature at a radio frequency plasma power of 150 W. Stannic chloride (SnCl 4 ) was used as precursor and oxygen (O 2 , 100 SCCM) (SCCM denotes cubic centimeter per minute at STP) as reactant gas. Palladium hexafluroacetyleacetonate (Pd(C 5 HF 6 O 2 ) 2 ) was used as a precursor for palladium. Fine granular morphology was observed with tetragonal rutile structure. A peak related to Pd 2 Sn is observed, whose intensity increases slightly with deposition temperature. Electrical resistivity value decreased from 8.6 to 0.9 mΩ cm as a function of deposition temperature from 400 to 600 deg. C. Photoelectron peaks related to Sn 3d, Sn 3p3, Sn 4d, O 1s, and C 1s were detected with varying intensities as a function of deposition temperature.

  5. Influence of extraction techniques on physical-chemical characteristics and volatile compounds of extra virgin olive oil.

    Science.gov (United States)

    Volpe, Maria Grazia; De Cunzo, Fausta; Siano, Francesco; Paolucci, Marina; Barbarisi, Costantina; Cammarota, Giancarlo

    2014-01-01

    The purpose of this study was to investigate three types of extraction methods of extra virgin olive oil (EVOO) from the same cultivar (Ortice olive cultivar): traditional or pressing (T) system, decanter centrifugation (DC) system and a patented horizontal axis decanter centrifugation (HADC) system. Oil samples were subjected to chemical analyses: free acidity, peroxide value, ultraviolet light absorption K232 and K270, total polyphenols, antioxidant capacity, volatile compounds and olfactory characteristics by electronic nose. The two centrifugation systems showed better free acidity and peroxides value but total polyphenol content was particularly high in extra virgin olive oil produced by patented HADC system. Same volatile substances that positively characterize the oil aroma were found in higher amount in the two centrifugation systems, although some differences have been detected between DC and HADC system, other were found in higher amount in extra virgin olive oil produced by T system. The electronic nose analysis confirmed these results, principal component analysis (PCA) and correlation matrix showed the major differences between EVOO produced by T and HADC system. Taken together the results showed that DC and HADC systems produce EVOO with better characteristics than T system and patented HADC is the best extraction system.

  6. Comparison between neurostimulation techniques rapid transcranial magnetic stimulation vs electroconvulsive therapy for the treatment of resistant depression: patient preference and cost-effectiveness

    Directory of Open Access Journals (Sweden)

    Magnezi R

    2016-08-01

    Full Text Available Racheli Magnezi,1 Emanuel Aminov,1 Dikla Shmuel,2 Merav Dreifuss,1 Pinhas Dannon1,2 1Public Health and Health Systems Management Program, Department of Management, Bar-Ilan University, Ramat Gan, 2Beer Yaakov Mental Health Center affiliated to Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel Objectives: Major depressive disorder (MDD is a common disorder, widely distributed in the population, and is often associated with severe symptoms and functional impairment. It has been estimated that 30% of MDD patients do not benefit adequately from therapeutic interventions, including pharmacotherapy and psychotherapy. Treatment-resistant depression (TRD is generally defined as a failure to achieve remission, despite therapeutic interventions. Aim: The most effective treatment alternatives for TRD are hospitalization, electroconvulsive therapy (ECT, and transcranial magnetic stimulation (TMS. Here we compared the clinical effectiveness of ECT and TMS, including success rates, patient responses, side-effect profiles, and financial worthiness. Results: We found that ECT (P<0.0001 was more effective than TMS (P<0.012 (not statistically significant in group effect in TRD patients. However, ECT patients reported a higher percentage of side effects (P<0.01 and the TMS treatment scored better in terms of patient preference. The cost benefit of ECT was higher than that of TMS (US$2075 vs US$814. Patient’s preferences for treatment could be more intense in the TMS, if the TMS is included in the Health Maintenance Organization’s service list. Conclusion: We propose that both of these treatment options should be available in psychiatric wards, thus expanding the therapeutic toolkit for TRD. Keywords: ECT, TMS, treatment-resistant depression, cost benefit, patient preference

  7. Does transcutaneous electrical nerve stimulation (TENS) alleviate the pain experienced during bone marrow sampling in addition to standard techniques? A randomised, double-blinded, controlled trial.

    Science.gov (United States)

    Tucker, David L; Rockett, Mark; Hasan, Mehedi; Poplar, Sarah; Rule, Simon A

    2015-06-01

    Bone marrow aspiration and trephine (BMAT) biopsies remain important tests in haematology. However, the procedures can be moderately to severely painful despite standard methods of pain relief. To test the efficacy of transcutaneous electrical nerve stimulation (TENS) in alleviating the pain from BMAT in addition to standard analgesia using a numerical pain rating scale (NRS). 70 patients requiring BMAT were randomised (1:1) in a double-blind, placebo-controlled trial. -35 patients received TENS impulses at a strong but comfortable amplitude (intervention group) and 35 patients received TENS impulses just above the sensory threshold (control group) (median pulse amplitude 20 and 7 mA, respectively). Patients and operators were blinded to group allocation. Pain assessments were made using a numerical pain scale completed after the procedure. No significant difference in NRS pain recalled after the procedure was detected (median pain score 5.7 (95% CI 4.8 to 6.6) in control vs 5.6 (95% CI 4.8 to 6.4) in the intervention group). However, 100% of patients who had previous experience of BMAT and >94% of participants overall felt they benefited from using TENS and would recommend it to others for this procedure. There were no side effects from the TENS device, and it was well tolerated. TENS is a safe, non-invasive adjunct to analgesia for reducing pain during bone marrow biopsy and provides a subjective benefit to most users; however, no objective difference in pain scores was detected when using TENS in this randomised controlled study. NCT02005354. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  8. Analysis of the chemical elements behavior in leaves infected with fumagina employing X-ray fluorescence technique

    International Nuclear Information System (INIS)

    Blonski, Maria Selia

    2002-02-01

    Fumagina is produced by the Capnodium fungi, a mushroom from Dothideales order, that lives associated with the yellow aphid (Monelliopsis pecanis), excreting a heavy load of a sugared substance that provides the sooty fungus development, covering, in some cases the totality, of leaves, fruits and branches surfaces. One of the big problems caused by this disease is the physic photosynthesis stuckness, reducing in 98% the active photosynthesis radiation and in 70% the net photosynthesis. This photosynthesis reduction affects the plants carbohydrate reservoirs, resulting in reduced and bad qualified crops. It was employed the Energy Dispersion X-Ray Fluorescence Technique (EDXRF) to study the fumagina disease. The measurements were realized with infected and healthy leaves of citric plants (orange and lemon trees), collected at the Farm School of the State University of Londrina, and also leaves of icsora plant from Piracicaba-SP. Through this technique it was observed a metabolic disorder related to Fe and Ca elements. By comparing the EDXRF spectra of the healthy plant leaves with the infected ones, it was verified that the concentration of Ca is higher than the concentration Fe in leaves of healthy plants, while for the leaves of plants infected with fumagina, it was observed a higher concentration of Fe. Employing EDXRF and the emission/transmission method for the matrix effect correction, samples of the citric plants were also analysed in pellet. The elements K, Ca, Ti, Mn , Fe, Cu and Zn were quantified. It was verified a higher Fe concentration in fumagina samples compared to the samples without fumagina. For all the elements of interest the minimum level of detection found was at the order of μg g -1 . (author)

  9. Brain Stimulation Therapies

    Science.gov (United States)

    ... Magnetic Seizure Therapy Deep Brain Stimulation Additional Resources Brain Stimulation Therapies Overview Brain stimulation therapies can play ... for a shorter recovery time than ECT Deep Brain Stimulation Deep brain stimulation (DBS) was first developed ...

  10. Chemical exchange saturation transfer (CEST) MR technique for in-vivo liver imaging at 3.0 tesla

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shu-Zhong; Deng, Min; Wang, Yi-Xiang J. [Chinese University of Hong Kong, Prince of Wales Hospital, Department of Imaging and Interventional Radiology, Faculty of Medicine (China); Yuan, Jing [Hong Kong Sanatorium and Hospital, Medical Physics and Research Department, Happy Valley, Hong Kong (China); Wei, Juan [Philips Healthcare Asia, Shanghai (China); Zhou, Jinyuan [Johns Hopkins University, Department of Radiology, Baltimore, MD (United States); Kennedy Krieger Institute, F.M. Kirby Research Center for Functional Brain Imaging, Baltimore, MD (United States)

    2016-06-15

    To evaluate Chemical Exchange Saturation Transfer (CEST) MRI for liver imaging at 3.0-T. Images were acquired at offsets (n = 41, increment = 0.25 ppm) from -5 to 5 ppm using a TSE sequence with a continuous rectangular saturation pulse. Amide proton transfer-weighted (APTw) and GlycoCEST signals were quantified as the asymmetric magnetization transfer ratio (MTR{sub asym}) at 3.5 ppm and the total MTR{sub asym} integrated from 0.5 to 1.5 ppm, respectively, from the corrected Z-spectrum. Reproducibility was assessed for rats and humans. Eight rats were devoid of chow for 24 hours and scanned before and after fasting. Eleven rats were scanned before and after one-time CCl4 intoxication. For reproducibility, rat liver APTw and GlycoCEST measurements had 95 % limits of agreement of -1.49 % to 1.28 % and -0.317 % to 0.345 %. Human liver APTw and GlycoCEST measurements had 95 % limits of agreement of -0.842 % to 0.899 % and -0.344 % to 0.164 %. After 24 hours, fasting rat liver APTw and GlycoCEST signals decreased from 2.38 ± 0.86 % to 0.67 ± 1.12 % and from 0.34 ± 0.26 % to -0.18 ± 0.37 % respectively (p < 0.05). After CCl4 intoxication rat liver APTw and GlycoCEST signals decreased from 2.46 ± 0.48 % to 1.10 ± 0.77 %, and from 0.34 ± 0.23 % to -0.16 ± 0.51 % respectively (p < 0.05). CEST liver imaging at 3.0-T showed high sensitivity for fasting as well as CCl4 intoxication. (orig.)

  11. Brain stimulation in migraine.

    Science.gov (United States)

    Brighina, Filippo; Cosentino, Giuseppe; Fierro, Brigida

    2013-01-01

    Migraine is a very prevalent disease with great individual disability and socioeconomic burden. Despite intensive research effort in recent years, the etiopathogenesis of the disease remains to be elucidated. Recently, much importance has been given to mechanisms underlying the cortical excitability that has been suggested to be dysfunctional in migraine. In recent years, noninvasive brain stimulation techniques based on magnetic fields (transcranial magnetic stimulation, TMS) and on direct electrical currents (transcranial direct current stimulation, tDCS) have been shown to be safe and effective tools to explore the issue of cortical excitability, activation, and plasticity in migraine. Moreover, TMS, repetitive TMS (rTMS), and tDCS, thanks to their ability to interfere with and/or modulate cortical activity inducing plastic, persistent effects, have been also explored as potential therapeutic approaches, opening an interesting perspective for noninvasive neurostimulation for both symptomatic and preventive treatment of migraine and other types of headache. In this chapter we critically review evidence regarding the role of noninvasive brain stimulation in the pathophysiology and treatment of migraine, delineating the advantages and limits of these techniques together with potential development and future application. © 2013 Elsevier B.V. All rights reserved.

  12. The potential of organic (electrospray- and atmospheric pressure chemical ionisation) mass spectrometric techniques coupled to liquid-phase separation for speciation analysis.

    Science.gov (United States)

    Rosenberg, Erwin

    2003-06-06

    The use of mass spectrometry based on atmospheric pressure ionisation techniques (atmospheric pressure chemical ionisation, APCI, and electrospray ionisation, ESI) for speciation analysis is reviewed with emphasis on the literature published in and after 1999. This report accounts for the increasing interest that atmospheric pressure ionisation techniques, and in particular ESI, have found in the past years for qualitative and quantitative speciation analysis. In contrast to element-selective detectors, organic mass spectrometric techniques provide information on the intact metal species which can be used for the identification of unknown species (particularly with MS-MS detection) or the confirmation of the actual presence of species in a given sample. Due to the complexity of real samples, it is inevitable in all but the simplest cases to couple atmospheric pressure MS detection to a separation technique. Separation in the liquid phase (capillary electrophoresis or liquid chromatography in reversed phase, ion chromatographic or size-exclusion mode) is particularly suitable since the available techniques cover a very wide range of analyte polarities and molecular mass. Moreover, derivatisation can normally be avoided in liquid-phase separation. Particularly in complex environmental or biological samples, separation in one dimension is not sufficient for obtaining adequate resolution for all relevant species. In this case, multi-dimensional separation, based on orthogonal separation techniques, has proven successful. ESI-MS is also often used in parallel with inductively coupled plasma MS detection. This review is structured in two parts. In the first, the fundamentals of atmospheric pressure ionisation techniques are briefly reviewed. The second part of the review discusses recent applications including redox species, use of ESI-MS for structural elucidation of metal complexes, characterisation and quantification of small organometallic species with relevance to

  13. Chemical exchange saturation transfer (CEST) MR technique for in-vivo liver imaging at 3.0 tesla.

    Science.gov (United States)

    Chen, Shu-Zhong; Yuan, Jing; Deng, Min; Wei, Juan; Zhou, Jinyuan; Wáng, Yì-Xiáng J

    2016-06-01

    To evaluate Chemical Exchange Saturation Transfer (CEST) MRI for liver imaging at 3.0-T. Images were acquired at offsets (n = 41, increment = 0.25 ppm) from -5 to 5 ppm using a TSE sequence with a continuous rectangular saturation pulse. Amide proton transfer-weighted (APTw) and GlycoCEST signals were quantified as the asymmetric magnetization transfer ratio (MTRasym) at 3.5 ppm and the total MTRasym integrated from 0.5 to 1.5 ppm, respectively, from the corrected Z-spectrum. Reproducibility was assessed for rats and humans. Eight rats were devoid of chow for 24 hours and scanned before and after fasting. Eleven rats were scanned before and after one-time CCl4 intoxication. For reproducibility, rat liver APTw and GlycoCEST measurements had 95 % limits of agreement of -1.49 % to 1.28 % and -0.317 % to 0.345 %. Human liver APTw and GlycoCEST measurements had 95 % limits of agreement of -0.842 % to 0.899 % and -0.344 % to 0.164 %. After 24 hours, fasting rat liver APTw and GlycoCEST signals decreased from 2.38 ± 0.86 % to 0.67 ± 1.12 % and from 0.34 ± 0.26 % to -0.18 ± 0.37 % respectively (p 3.0-T showed high sensitivity for fasting as well as CCl4 intoxication. • CEST MRI of in-vivo liver was demonstrated at clinical 3 T field strength. • After 24-hour fasting, rat liver APTw and GlycoCEST signals decreased significantly. • After CCl4 intoxication both rat liver APTw and GlycoCEST signals decreased significantly. • Good scan-rescan reproducibility of liver CEST MRI was shown in healthy volunteers.

  14. Effects of pH and temperature on the deposition properties of stannate chemical conversion coatings formed by the potentiostatic technique on AZ91 D magnesium alloy

    International Nuclear Information System (INIS)

    Elsentriecy, Hassan H.; Azumi, Kazuhisa; Konno, Hidetaka

    2008-01-01

    The effects of pH and temperature of a stannate bath on the quality of stannate chemical conversion coatings formed on AZ91 D magnesium alloy by using the potentiostatic polarization technique at E = -1.1 V were investigated in order to improve uniformity and corrosion protection performance of the coating films. It was found that the uniformity and corrosion resistance of coating films deposited by potentiostatic polarization were closely associated with pH and temperature of the coating bath. The pH and temperature to obtain the best coating film were investigated as a function of corrosion protection performance evaluated by curves of potentiodynamic anodic polarization conducted in borate buffer solution. Scanning electron microscope observation and electrochemical corrosion tests of the stannate-coated samples confirmed significant improvement in uniformity and corrosion resistivity of coating films deposited by the potentiostatic technique by modifying the pH and temperature of the coating bath. It was also found that uniformity and corrosion resistivity of the coating films deposited by the potentiostatic technique were considerably improved compared to those of coatings deposited by the simple immersion method at the best conditions of pH and temperature of the coating bath

  15. Supercritical fluid extraction of grape seeds: extract chemical composition, antioxidant activity and inhibition of nitrite production in LPS-stimulated Raw 264.7 cells.

    Science.gov (United States)

    Pérez, Concepción; Ruiz del Castillo, María Luisa; Gil, Carmen; Blanch, Gracia Patricia; Flores, Gema

    2015-08-01

    Grape by-products are a rich source of bioactive compounds having broad medicinal properties, but are usually wasted from juice/wine processing industries. The present study investigates the use of supercritical fluid extraction (SFE) for obtaining an extract rich in bioactive compounds. First, some variables involved in the extraction were applied. SFE conditions were selected based on the oil mass yield, fatty acid profile and total phenolic composition. As a result, 40 °C and 300 bar were selected as operational conditions. The phenolic composition of the grape seed oil was determined using LC-DAD. The antioxidant activity was determined by ABTS and DPPH assays. For the anti-inflammatory activity the inhibition of nitrite production was assessed. The grape seed oil extracted was rich in phenolic compounds and fatty acids with significant antioxidant and anti-inflammatory activities. From these results, added economic value to this agroindustrial residue is proposed using environmentally friendly techniques.

  16. Detection of irradiated foods with the photo-stimulated luminescence technique. Selection of a glass fiber filter for evaluating the performance of the PSL detectors

    International Nuclear Information System (INIS)

    Sekiguchi, Masayuki; Yamazaki, Masao; Goto, Michiko

    2008-01-01

    The PSL method is useful as a screening technique of irradiated foods to support efficient uses of TL analysis. Recently, there has been the growing need for the system check or calibration using the standard materials with spread of domestically -produced PSL detector. In this research, we characterized the PSL of several types of glass fiber filters and compared the cumulate photon counts of a selected filter of them (GA-100) with those of the SUERC paprika standard for PSL measurements. GA-100 filter showed a linear relationship between cumulate photon counts and irradiation doses, and the cumulate photon counts in the first 2 months after gamma rays irradiation (261Gy) were markedly decreased and reduced to about 5000 counts (the upper threshold of PSL) after 4 months. However, further long-term storage and dose increase was necessary to produce the filter with more adequate PSI property as a standard material. Light exposure (630Lux) within 3 minutes to GA-100 had little effect on the cumulate photon counts. GA-100 showed relatively less variation in cumulate photon counts compared with the paprika standard in a series of studies. (author)

  17. Evidence of chemical stimulation of hepatic metabolism by an experimental acetanilide (FOE 5043) indirectly mediating reductions in circulating thyroid hormone levels in the male rat.

    Science.gov (United States)

    Christenson, W R; Becker, B D; Wahle, B S; Moore, K D; Dass, P D; Lake, S G; Van Goethem, D L; Stuart, B P; Sangha, G K; Thyssen, J H

    1996-02-01

    N-(4-Fluorophenyl)-N-(1-methylethyl)-2-[[5-(trifluoromethyl)-1,3, 4-thiadiazol-2-yl]oxy]acetamide (FOE 5043) is a new acetanilide-type herbicide undergoing regulatory testing. Previous work in this laboratory suggested that FOE 5043-induced reductions in serum thyroxine (T4) levels were mediated via an extrathyroidal site of action. The possibility that the alterations in circulating T4 levels were due to chemical induction of hepatic thyroid hormone metabolism was investigated. Treatment with FOE 5043 at a rate of 1000 ppm as a dietary admixture was found to significantly increase the clearance of [125I]T4 from the serum, suggesting an enhanced excretion of the hormone. In the liver, the activity of hepatic uridine glucuronosyl transferase, a major pathway of thyroid hormone biotransformation in the rat, increased in a statistically significant and dose-dependent manner; conversely, hepatic 5'-monodeiodinase activity trended downward with dose. Bile flow as well as the hepatic uptake and biliary excretion of [125I]T4 were increased following exposure to FOE 5043. Thyroidal function, as measured by the discharge of iodide ion in response to perchlorate, and pituitary function, as measured by the capacity of the pituitary to secrete thyrotropin in response to an exogenous challenge by hypothalamic thyrotropin releasing hormone, were both unchanged from the controlled response. These data suggest that the functional status of the thyroid and pituitary glands has not been altered by treatment with FOE 5043 and that reductions in circulating levels of T4 are being mediated indirectly through an increase in the biotransformation and excretion of thyroid hormone in the liver.

  18. Computationally Developed Sham Stimulation Protocol for Multichannel Desynchronizing Stimulation

    Directory of Open Access Journals (Sweden)

    Magteld Zeitler

    2018-05-01

    our computational findings we propose a multichannel sham (i.e., inactive stimulation protocol as control condition for phase 2 and phase 3 studies with desynchronizing multichannel stimulation techniques.

  19. Investigation of chemical vapour deposition diamond detectors by X-ray micro-beam induced current and X-ray micro-beam induced luminescence techniques

    International Nuclear Information System (INIS)

    Olivero, P.; Manfredotti, C.; Vittone, E.; Fizzotti, F.; Paolini, C.; Lo Giudice, A.; Barrett, R.; Tucoulou, R.

    2004-01-01

    Tracking detectors have become an important ingredient in high-energy physics experiments. In order to survive the harsh detection environment of the large hadron collider (LHC), trackers need to have special properties. They must be radiation hard, provide fast collection of charge, be as thin as possible and remove heat from readout electronics. The unique properties of diamond allow it to fulfill these requirements. In this work we present an investigation of the charge transport and luminescence properties of 'detector grade' artificial chemical vapour deposition (CVD) diamond devices developed within the CERN RD42 collaboration, performed by means of X-ray micro-beam induced current collection (XBICC) and X-ray micro-beam induced luminescence (XBIL) techniques. XBICC technique allows quantitative estimates of the transport parameters of the material to be evaluated and mapped with micrometric spatial resolution. In particular, the high resolution and sensitivity of the technique has allowed a quantitative study of the inhomogeneity of the charge transport parameter defined as the product of mobility and lifetime for both electron and holes. XBIL represents a technique complementary to ion beam induced luminescence (IBIL), which has already been used by our group, since X-ray energy loss profile in the material is different from that of MeV ions. X-ray induced luminescence maps have been performed simultaneously with induced photocurrent maps, to correlate charge transport and induced luminescence properties of diamond. Simultaneous XBICC and XBIL maps exhibit features of partial complementarity that have been interpreted on the basis of considerations on radiative and non-radiative recombination processes which compete with charge transport efficiency

  20. Structural and electronic properties of InN epitaxial layer grown on c-plane sapphire by chemical vapor deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Barick, Barun Kumar, E-mail: bkbarick@gmail.com; Prasad, Nivedita; Saroj, Rajendra Kumar; Dhar, Subhabrata [Department of Physics, Indian Institute of Technology, Bombay, Mumbai 400076 (India)

    2016-09-15

    Growth of InN epilayers on c-plane sapphire substrate by chemical vapor deposition technique using pure indium metal and ammonia as precursors has been systematically explored. It has been found that [0001] oriented indium nitride epitaxial layers with smooth surface morphology can be grown on c-plane sapphire substrates by optimizing the growth conditions. Bandgap of the film is observed to be Burstein–Moss shifted likely to be due to high background electron concentration. It has been found that the concentration of this unintentional doping decreases with the increase in the growth temperature and the ammonia flux. Epitaxial quality on the other hand deteriorates as the growth temperature increases. Moreover, the morphology of the deposited layer has been found to change from flat top islands to faceted mounds as the flow rate of ammonia increases. This phenomenon is expected to be related to the difference in surface termination character at low and high ammonia flow rates.

  1. Studies of CdS/CdTe interface: Comparison of CdS films deposited by close space sublimation and chemical bath deposition techniques

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jun-feng, E-mail: pkuhjf@bit.edu.cn [Institut des Matériaux Jean Rouxel (IMN), Université de Nantes, UMR CNRS 6502, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France); Institute of Materials Science, Darmstadt University of Technology, Petersenstr. 23, 64287 Darmstadt (Germany); School of Physics, Beijing Institute of Technology, Beijing 100081 (China); Fu, Gan-hua; Krishnakumar, V.; Schimper, Hermann-Josef [Institute of Materials Science, Darmstadt University of Technology, Petersenstr. 23, 64287 Darmstadt (Germany); Liao, Cheng [Department of Physics, Peking University, Beijing 100871 (China); Jaegermann, Wolfram [Institute of Materials Science, Darmstadt University of Technology, Petersenstr. 23, 64287 Darmstadt (Germany); Besland, M.P. [Institut des Matériaux Jean Rouxel (IMN), Université de Nantes, UMR CNRS 6502, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France)

    2015-05-01

    The CdS layers were deposited by two different methods, close space sublimation (CSS) and chemical bath deposition (CBD) technique. The CdS/CdTe interface properties were investigated by transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). The TEM images showed a large CSS-CdS grain size in the range of 70-80 nm. The interface between CSS-CdS and CdTe were clear and sharp, indicating an abrupt hetero-junction. On the other hand, CBD-CdS layer had much smaller grain size in the 5-10 nm range. The interface between CBD-CdS and CdTe was not as clear as CSS-CdS. With the stepwise coverage of CdTe layer, the XPS core levels of Cd 3d and S 2p in CSS-CdS had a sudden shift to lower binding energies, while those core levels shifted gradually in CBD-CdS. In addition, XPS depth profile analyses indicated a strong diffusion in the interface between CBD-CdS and CdTe. The solar cells prepared using CSS-CdS yielded better device performance than the CBD-CdS layer. The relationships between the solar cell performances and properties of CdS/CdTe interfaces were discussed. - Highlights: • Studies of CdS deposited by close space sublimation and chemical bath deposition • An observation of CdS/CdTe interface by transmission electron microscope • A careful investigation of CdS/CdTe interface by X ray photoelectron spectra • An easier diffusion at the chemical bath deposition CdS and CdTe interface.

  2. Effect of three pretreatment techniques on the chemical composition and on the methane yields of Opuntia ficus-indica (prickly pear) biomass.

    Science.gov (United States)

    Calabrò, P S; Catalán, E; Folino, A; Sánchez, A; Komilis, D

    2018-01-01

    Opuntia ficus-indica (OFI) is an emerging biomass that has the potential to be used as substrate in anaerobic digestion. The goal of this work was to investigate the effect of three pretreatment techniques (thermal, alkaline, acidic) on the chemical composition and the methane yield of OFI biomass. A composite experimental design with three factors and two to three levels was implemented, and regression modelling was employed using a total of 10 biochemical methane potential (BMP) tests. The measured methane yields ranged from 289 to 604 NmL/gVS added ; according to the results, only the acidic pretreatment (HCl) was found to significantly increase methane generation. However, as the experimental values were quite high with regards to the theoretical methane yield of the substrate, this effect still needs to be confirmed via further research. The alkaline pretreatment (NaOH) did not noticeably affect methane yields (an average reduction of 8% was recorded), despite the fact that it did significantly reduce the lignin content. Thermal pretreatment had no effect on the methane yields or the chemical composition. Scanning electron microscopy images revealed changes in the chemical structure after the addition of NaOH and HCl. Modelling of the cumulated methane production by the Gompertz modified equation was successful and aided in understanding kinetic advantages linked to some of the pretreatments. For example, the alkaline treatment (at the 20% dosage) at room temperature resulted to a μ max (maximum specific methane production rate [NmLCH 4 /(gVS added ·d)]) equal to 36.3 against 18.6 for the control.

  3. A study of some neutron-rich isotopes of lanthanum, cerium and praseodymium by means of fast chemical on-line separation technique SISAK

    International Nuclear Information System (INIS)

    Skarnemark, G.

    1977-01-01

    The fast on-line chemical separation technique SISAK has been utilized to study the decay properties of neutron-rich isotopes of La, Ce and Pr. The results include partial decay schemes and γ-ray intensity data for 14 min 143 La, 42 s 144 La, 25 s 145 La, 9 s 146 La, 3 min 145 Ce, 14 min 146 Ce, 56 s 147 Ce, 50 s 148 Ce, 12 min 147 Pr, 2 min 148 Pr, 3 min 149 Pr and 6 s 150 Pr. Half-lives and γ-ray energies are reported for the previously unknown nuclides 147 La (Tsub(1/2) = 2.2 s), 148 La (Tsub(1/2) approximately 1 s), 149 Ce (Tsub(1/2) = 5.7 s) and 150 Ce (Tsub(1/2) = 4.1 s). The nuclides were formed in thermal neutron-induced fission of 235 U. The fission products were transferred to the SISAK system via a gas jet recoil transportation (GJRT) system. The combination of the GJRT system with SISAK is discussed, as well as the chemical separation systems used for the isolation of La, Ce and Pr. The appendices I - IX contain previously published material which is included in the thesis. (Auth.)

  4. Analysis of chemical bond states and electrical properties of stacked AlON/HfO{sub 2} gate oxides formed by using a layer-by-layer technique

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Wonjoon; Lee, Jonghyun; Yang, Jungyup; Kim, Chaeok; Hong, Jinpyo; Nahm, Tschanguh; Byun, Byungsub; Kim, Moseok [Hanyang University, Seoul (Korea, Republic of)

    2006-06-15

    Stacked AlON/HfO{sub 2} thin films for gate oxides in metal-oxide-semiconductor devices are successfully prepared on Si substrates by utilizing a layer-by-layer technique integrated with an off-axis RF remote plasma sputtering process at room temperature. This off-axis structure is designed to improve the uniformity and the quality of gate oxide films. Also, a layer-by-layer technique is used to control the interface layer between the gate oxide and the Si substrate. The electrical properties of our stacked films are characterized by using capacitance versus voltage and leakage current versus voltage measurements. The stacked AlON/HfO{sub 2} gate oxide exhibits a low leakage current of about 10{sup -6} A/cm{sup 2} and a high dielectric constant value of 14.26 by effectively suppressing the interface layer between gate oxide and Si substrate. In addition, the chemical bond states and the optimum thickness of each AlON and HfO{sub 2} thin film are analyzed using X-ray photoemission spectroscopy and transmission electron microscopy measurement.

  5. Molecular activation analysis for chemical speciation studies

    International Nuclear Information System (INIS)

    Chai-Chifang

    1998-01-01

    The term of Molecular Activation Analysis (MAA) refers to an activation analysis method that is able to provide information about the chemical species of elements in system of interests, though its definition has remained to be assigned. Its development is strongly stimulated by the urgent need to know the chemical species of elements, because the total concentrations are often without any meaning when assessing health or environmental risks of trace elements.In practice, the MAA is a combination of conventional instrumental or radiochemical activation analysis and physical, chemical or biochemical separation techniques. The MAA is able to play a particular role in speciation studies. However, the critical point in the MAA is that it is not permitted to change the primitive chemical species of elements in systems, or the change has to be under control; in the meantime it is not allowed to form the 'new artifact' originally not present in systems. Some practical examples of MAA for chemical species research performed recently in our laboratory will be presented as follows: Chemical species of platinum group elements in sediment; Chemical species of iodine in marine algae; Chemical species of mercury in human tissues; Chemical species of selenium in corn; Chemical species of rare earth elements in natural plant, etc. The merits and limitations of MAA will be described as well. (author)

  6. MR-sialography: optimisation and evaluation of an ultra-fast sequence in parallel acquisition technique and different functional conditions of salivary glands; MR-Sialographie: Optimierung und Bewertung ultraschneller Sequenzen mit paralleler Bildgebung und oraler Stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Habermann, C.R.; Cramer, M.C.; Aldefeld, D.; Weiss, F.; Kaul, M.G.; Adam, G. [Radiologisches Zentrum, Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Universitaetsklinikum Hamburg-Eppendorf (Germany); Graessner, J. [Siemens Medical Systems, Hamburg (Germany); Reitmeier, F.; Jaehne, M. [Kopf- und Hautzentrum, Klinik und Poliklinik fuer Hals-, Nasen- und Ohrenheilkunde, Universitaetsklinikum Hamburg-Eppendorf (Germany); Petersen, K.U. [Zentrum fuer Psychosoziale Medizin, Klinik und Poliklinik fuer Psychiatrie und Psychotherapie, Universitaetsklinikum Hamburg-Eppendorf (Germany)

    2005-04-01

    Purpose: To optimise a fast sequence for MR-sialography and to compare a parallel and non-parallel acquisition technique. Additionally, the effect of oral stimulation regarding the image quality was evaluated. Material and Methods: All examinations were performed by using a 1.5-T superconducting system. After developing a sufficient sequence for MR-sialography, a single-shot turbo-spin-echo sequence (ss-TSE) with an acquisition time of 2.8 sec was used in transverse and oblique sagittal orientation in 27 healthy volunteers. All images were performed with and without parallel imaging technique. The assessment of the ductal system of the submandibular and parotid gland was performed using a 1 to 5 visual scale for each side separately. Images were evaluated by four independent experienced radiologists. For statistical evaluation, an ANOVA with post-hoc comparisons was used with an overall two-tailed significance level of P=.05. For evaluation of interobserver variability, an intraclass correlation was computed and correlation >.08 was determined to indicate a high correlation. Results: All parts of salivary excretal ducts could be visualised in all volunteers, with an overall rating for all ducts of 2.26 (SD{+-}1.09). Between the four observers a high correlation could be obtained with an intraclass correlation of 0.9475. A significant influence regarding the slice angulations could not be obtained (p=0.74). In all healthy volunteers the visibility of excretory ducts improved significantly after oral application of a Sialogogum (p<0.001; {eta}{sup 2}=0.049). The use of a parallel imaging technique did not lead to an improvement of visualisation, showing a significant loss of image quality compared to an acquistion technique without parallel imaging (p<0.001; {eta}{sup 2}=0.013). Conclusion: The optimised ss-TSE MR-sialography seems to be a fast and sufficient technique for visualisation of excretory ducts of the main salivary glands, with no elaborate post

  7. Stimulated Raman scattering: old physics, new applications.

    Science.gov (United States)

    Yakovlev, Vladislav V; Petrov, Georgi I; Zhang, Hao F; Noojin, Gary D; Denton, Michael L; Thomas, Robert J; Scully, Marlan O

    2009-10-01

    Stimulated Raman scattering as a promising way of expanding the tunability of ultrafast lasers and as an exciting new biomedical imaging modality capable of selective excitation and chemically-specific diagnostics of molecular species.

  8. Noninvasive transcranial brain stimulation and pain.

    Science.gov (United States)

    Rosen, Allyson C; Ramkumar, Mukund; Nguyen, Tam; Hoeft, Fumiko

    2009-02-01

    Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) are two noninvasive brain stimulation techniques that can modulate activity in specific regions of the cortex. At this point, their use in brain stimulation is primarily investigational; however, there is clear evidence that these tools can reduce pain and modify neurophysiologic correlates of the pain experience. TMS has also been used to predict response to surgically implanted stimulation for the treatment of chronic pain. Furthermore, TMS and tDCS can be applied with other techniques, such as event-related potentials and pharmacologic manipulation, to illuminate the underlying physiologic mechanisms of normal and pathological pain. This review presents a description and overview of the uses of two major brain stimulation techniques and a listing of useful references for further study.

  9. New electrical stimulation techniques in dynamic myopasty

    NARCIS (Netherlands)

    Zonnevylle, Erik Dirk Hendrik

    2002-01-01

    It has become common practice in reconstructive surgery to transpose or transplant a variety of autologous tissues to fill defects at a recipient site. Using muscle tissue, it becomes possible to dynamically assist or replace an impaired or lost function. For these procedures the term ‘dynamic

  10. Stimulating Deep Learning Using Active Learning Techniques

    Science.gov (United States)

    Yew, Tee Meng; Dawood, Fauziah K. P.; a/p S. Narayansany, Kannaki; a/p Palaniappa Manickam, M. Kamala; Jen, Leong Siok; Hoay, Kuan Chin

    2016-01-01

    When students and teachers behave in ways that reinforce learning as a spectator sport, the result can often be a classroom and overall learning environment that is mostly limited to transmission of information and rote learning rather than deep approaches towards meaningful construction and application of knowledge. A group of college instructors…

  11. Control of cell behaviour through nanovibrational stimulation: nanokicking

    Science.gov (United States)

    Robertson, Shaun N.; Campsie, Paul; Childs, Peter G.; Madsen, Fiona; Donnelly, Hannah; Henriquez, Fiona L.; Mackay, William G.; Salmerón-Sánchez, Manuel; Tsimbouri, Monica P.; Williams, Craig; Dalby, Matthew J.; Reid, Stuart

    2018-05-01

    Mechanical signals are ubiquitous in our everyday life and the process of converting these mechanical signals into a biological signalling response is known as mechanotransduction. Our understanding of mechanotransduction, and its contribution to vital cellular responses, is a rapidly expanding field of research involving complex processes that are still not clearly understood. The use of mechanical vibration as a stimulus of mechanotransduction, including variation of frequency and amplitude, allows an alternative method to control specific cell behaviour without chemical stimulation (e.g. growth factors). Chemical-independent control of cell behaviour could be highly advantageous for fields including drug discovery and clinical tissue engineering. In this review, a novel technique is described based on nanoscale sinusoidal vibration. Using finite-element analysis in conjunction with laser interferometry, techniques that are used within the field of gravitational wave detection, optimization of apparatus design and calibration of vibration application have been performed. We further discuss the application of nanovibrational stimulation, or `nanokicking', to eukaryotic and prokaryotic cells including the differentiation of mesenchymal stem cells towards an osteoblast cell lineage. Mechanotransductive mechanisms are discussed including mediation through the Rho-A kinase signalling pathway. Optimization of this technique was first performed in two-dimensional culture using a simple vibration platform with an optimal frequency and amplitude of 1 kHz and 22 nm. A novel bioreactor was developed to scale up cell production, with recent research demonstrating that mesenchymal stem cell differentiation can be efficiently triggered in soft gel constructs. This important step provides first evidence that clinically relevant (three-dimensional) volumes of osteoblasts can be produced for the purpose of bone grafting, without complex scaffolds and/or chemical induction

  12. Geothermal Reservoir Well Stimulation Program: technology transfer

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-01

    A literature search on reservoir and/or well stimulation techniques suitable for application in geothermal fields is presented. The literature on stimulation techniques in oil and gas field applications was also searched and evaluated as to its relevancy to geothermal operations. The equivalent low-temperature work documented in the open literature is cited, and an attempt is made to evaluate the relevance of this information as far as high-temperature stimulation work is concerned. Clays play an important role in any stimulation work. Therefore, special emphasis has been placed on clay behavior anticipated in geothermal operations. (MHR)

  13. Atmospheric pressure chemical ionization studies of non-polar isomeric hydrocarbons using ion mobility spectrometry and mass spectrometry with different ionization techniques

    Science.gov (United States)

    Borsdorf, H.; Nazarov, E. G.; Eiceman, G. A.

    2002-01-01

    The ionization pathways were determined for sets of isomeric non-polar hydrocarbons (structural isomers, cis/trans isomers) using ion mobility spectrometry and mass spectrometry with different techniques of atmospheric pressure chemical ionization to assess the influence of structural features on ion formation. Depending on the structural features, different ions were observed using mass spectrometry. Unsaturated hydrocarbons formed mostly [M - 1]+ and [(M - 1)2H]+ ions while mainly [M - 3]+ and [(M - 3)H2O]+ ions were found for saturated cis/trans isomers using photoionization and 63Ni ionization. These ionization methods and corona discharge ionization were used for ion mobility measurements of these compounds. Different ions were detected for compounds with different structural features. 63Ni ionization and photoionization provide comparable ions for every set of isomers. The product ions formed can be clearly attributed to the structures identified. However, differences in relative abundance of product ions were found. Although corona discharge ionization permits the most sensitive detection of non-polar hydrocarbons, the spectra detected are complex and differ from those obtained with 63Ni ionization and photoionization. c. 2002 American Society for Mass Spectrometry.

  14. The effect of thermal annealing on the optical band gap of cadmium sulphide thin films, prepared by the chemical bath deposition technique

    International Nuclear Information System (INIS)

    Ampong, F. K.; Boakye, F.; Asare Donkor, N. K.

    2010-01-01

    Cadmium sulphide thin films have been prepared by the chemical bath deposition technique (ph 11, 70 degree centigrade). Two different sets of films were prepared under varied conditions and concentrations of their ions sources (Cd 2+ from cadmium nitrate, S 2- from thiourea) and Na 2 EDTA as a complexing agent. A UV mini-Schimazu UV-VIS Spectrophotometer was used to determine the optical absorbance of the films as a function of wavelength at room temperature over the wavelength range 200 - 600 nm. The samples were then thermally annealed for thirty minutes, at temperatures of 100 degree centigrade, and 200 degree centigrade, after which the absorbance of the films were again recorded. The band gap values obtained for the sample with 0.5 M CdS as deposited, annealed at 100 degree centigrade and 200 degree centigrade were 2.1 eV, 2.2 eV and 2.3 eV respectively. Whilst the values obtained for the sample 0.15 CdS as deposited, annealed at 100 degree centigrade and annealed at 200 degree centigrade were 2.0 eV, 2.01 eV and 2.02 eV respectively. The increase in band gap with annealing temperature might be attributed to the improvement in crystallinity in the films. (au)

  15. Analysis of chemical dissolution of the barrier layer of porous oxide on aluminum thin films using a re-anodizing technique

    Energy Technology Data Exchange (ETDEWEB)

    Vrublevsky, I. [Department of Microelectronics, Belarusian State University of Informatics and Radioelectronics, 6 Brovka street, Minsk 220013 (Belarus)]. E-mail: nil-4-2@bsuir.edu.by; Parkoun, V. [Department of Microelectronics, Belarusian State University of Informatics and Radioelectronics, 6 Brovka street, Minsk 220013 (Belarus); Sokol, V. [Department of Microelectronics, Belarusian State University of Informatics and Radioelectronics, 6 Brovka street, Minsk 220013 (Belarus); Schreckenbach, J. [Institut fuer Chemie, Technische Universitaet Chemnitz, Chemnitz D-09107 (Germany)

    2005-09-30

    Chemical dissolution of the barrier layer of porous oxide formed on thin aluminum films (99.9% purity) in the 4% oxalic acid after immersion in 2 mol dm{sup -3} sulphuric acid at 50 deg. C has been studied. The barrier layer thickness before and after dissolution was calculated using a re-anodizing technique. It has been shown that above 57 V the change in the growth mechanism of porous alumina films takes place. As a result, the change in the amount of regions in the barrier oxide with different dissolution rates is observed. The barrier oxide contains two layers at 50 V: the outer layer with the highest dissolution rate and the inner layer with a low dissolution rate. Above 60 V the barrier oxide contains three layers: the outer layer with a high dissolution rate, the middle layer with the highest dissolution rate and the inner layer with a low dissolution rate. We suggest that the formation of the outer layer of barrier oxide with a high dissolution rate is linked with the injection of protons or H{sub 3}O{sup +} ions from the electrolyte into the oxide film at the anodizing voltages above 57 V.

  16. Improvement of the optical quality of site-controlled InAs quantum dots by a double stack growth technique in wet-chemically etched holes

    Energy Technology Data Exchange (ETDEWEB)

    Pfau, Tino Johannes; Gushterov, Aleksander; Reithmaier, Johann-Peter [Technische Physik, INA, Universitaet Kassel (Germany); Cestier, Isabelle; Eisenstein, Gadi [Electrical Engineering Dept., Technion, Haifa (Israel); Linder, Evgany; Gershoni, David [Solid State Institute and Physics Dept., Technion, Haifa (Israel)

    2010-07-01

    The optimization of the wet-chemically etching of holes and a special MBE growth stack technique allows enlarging the site-control of low density InAs QDs on GaAs substrates up to a buffer layer thickness of 55 nm. The strain of InAs QDs, grown in the etched holes, reduces the hole closing, so that a pre-patterned surface is conserved for the second QD layer. The distance of 50 nm GaAs between the two QD layers exceeds drastically the maximum vertical alignment based on pure strain coupling (20 nm). Compared to stacks with several QD layers, this method avoids electronic coupling between the different QD layers and reduces the problems to distinguish the dots of different layers optically. Confocal microphotoluminescence reveals a significant diminution of the low temperature photoluminescence linewidth of the second InAs QD layer to an average value of 505{+-}53 {mu}eV and a minimum width of 460 {mu}eV compared to 2 to 4 meV for QDs grown on thin buffer layers. The increase of the buffer layer thickness decreases the influence of the surface defects caused by prepatterning.

  17. Effects of Surface Modification of Nanodiamond Particles for Nucleation Enhancement during Its Film Growth by Microwave Plasma Jet Chemical Vapour Deposition Technique

    Directory of Open Access Journals (Sweden)

    Chii-Ruey Lin

    2014-01-01

    Full Text Available The seedings of the substrate with a suspension of nanodiamond particles (NDPs were widely used as nucleation seeds to enhance the growth of nanostructured diamond films. The formation of agglomerates in the suspension of NDPs, however, may have adverse impact on the initial growth period. Therefore, this paper was aimed at the surface modification of the NDPs to enhance the diamond nucleation for the growth of nanocrystalline diamond films which could be used in photovoltaic applications. Hydrogen plasma, thermal, and surfactant treatment techniques were employed to improve the dispersion characteristics of detonation nanodiamond particles in aqueous media. The seeding of silicon substrate was then carried out with an optimized spin-coating method. The results of both Fourier transform infrared spectroscopy and dynamic light scattering measurements demonstrated that plasma treated diamond nanoparticles possessed polar surface functional groups and attained high dispersion in methanol. The nanocrystalline diamond films deposited by microwave plasma jet chemical vapour deposition exhibited extremely fine grain and high smooth surfaces (~6.4 nm rms on the whole film. These results indeed open up a prospect of nanocrystalline diamond films in solar cell applications.

  18. The influence of charge effect on the growth of hydrogenated amorphous silicon by the hot-wire chemical vapor deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Q.; Nelson, B.P.; Iwaniczko, E.; Mahan, A.H.; Crandall, R.S.; Benner, J. [National Renewable Energy Lab., Golden, CO (United States)

    1998-09-01

    The authors observe at lower substrate temperatures that the scatter in the dark conductivity on hydrogenated amorphous silicon (a-Si:H) films grown on insulating substrates (e.g., Corning 7059 glass) by the hot-wire chemical vapor deposition technique (HWCVD) can be five orders of magnitude or more. This is especially true at deposition temperatures below 350 C. However, when the authors grow the same materials on substrates with a conductive grid, virtually all of their films have acceptable dark conductivity (< 5 {times} 10{sup {minus}10} S/cm) at all deposition temperatures below 425 C. This is in contrast to only about 20% of the materials grown in this same temperature range on insulating substrates having an acceptable dark conductivity. The authors estimated an average energy of 5 eV electrons reaching the growing surface in vacuum, and did additional experiments to see the influence of both the electron flux and the energy of the electrons on the film growth. Although these effects do not seem to be important for growing a-Si:H by HWCVD on conductive substrates, they help better understand the important parameters for a-Si:H growth, and thus, to optimize these parameters in other applications of HWCVD technology.

  19. Estimating representative background PM2.5 concentration in heavily polluted areas using baseline separation technique and chemical mass balance model

    Science.gov (United States)

    Gao, Shuang; Yang, Wen; Zhang, Hui; Sun, Yanling; Mao, Jian; Ma, Zhenxing; Cong, Zhiyuan; Zhang, Xian; Tian, Shasha; Azzi, Merched; Chen, Li; Bai, Zhipeng

    2018-02-01

    The determination of background concentration of PM2.5 is important to understand the contribution of local emission sources to total PM2.5 concentration. The purpose of this study was to exam the performance of baseline separation techniques to estimate PM2.5 background concentration. Five separation methods, which included recursive digital filters (Lyne-Hollick, one-parameter algorithm, and Boughton two-parameter algorithm), sliding interval and smoothed minima, were applied to one-year PM2.5 time-series data in two heavily polluted cities, Tianjin and Jinan. To obtain the proper filter parameters and recession constants for the separation techniques, we conducted regression analysis at a background site during the emission reduction period enforced by the Government for the 2014 Asia-Pacific Economic Cooperation (APEC) meeting in Beijing. Background concentrations in Tianjin and Jinan were then estimated by applying the determined filter parameters and recession constants. The chemical mass balance (CMB) model was also applied to ascertain the effectiveness of the new approach. Our results showed that the contribution of background PM concentration to ambient pollution was at a comparable level to the contribution obtained from the previous study. The best performance was achieved using the Boughton two-parameter algorithm. The background concentrations were estimated at (27 ± 2) μg/m3 for the whole year, (34 ± 4) μg/m3 for the heating period (winter), (21 ± 2) μg/m3 for the non-heating period (summer), and (25 ± 2) μg/m3 for the sandstorm period in Tianjin. The corresponding values in Jinan were (30 ± 3) μg/m3, (40 ± 4) μg/m3, (24 ± 5) μg/m3, and (26 ± 2) μg/m3, respectively. The study revealed that these baseline separation techniques are valid for estimating levels of PM2.5 air pollution, and that our proposed method has great potential for estimating the background level of other air pollutants.

  20. Electrical stimulation in exercise training

    Science.gov (United States)

    Kroll, Walter

    1994-01-01

    Electrical stimulation has a long history of use in medicine dating back to 46 A.D. when the Roman physician Largus found the electrical discharge of torpedo fishes useful in the treatment of pain produced by headache and gout. A rival Greek physician, Dioscorides, discounted the value of the torpedo fish for headache relief but did recommend its use in the treatment of hemorrhoids. In 1745, the Leyden jar and various sized electrostatic generators were used to treat angina pectoris, epilepsy, hemiplegia, kidney stones, and sciatica. Benjamin Franklin used an electrical device to treat successfully a young woman suffering from convulsive fits. In the late 1800's battery powered hydroelectric baths were used to treat chronic inflammation of the uterus while electrified athletic supporters were advertised for the treatment of male problems. Fortunately, such an amusing early history of the simple beginnings of electrical stimulation did not prevent eventual development of a variety of useful therapeutic and rehabilitative applications of electrical stimulation. Over the centuries electrical stimulation has survived as a modality in the treatment of various medical disorders with its primary application being in the rehabilitation area. Recently, a surge of new interest in electrical stimulation has been kindled by the work of a Russian sport scientist who reported remarkable muscle strength and endurance improvements in elite athletes. Yakov Kots reported his research on electric stimulation and strength improvements in 1977 at a Canadian-Soviet Exchange Symposium held at Concordia University in Montreal. Since then an explosion of new studies has been seen in both sport science and in medicine. Based upon the reported works of Kots and the present surge of new investigations, one could be misled as to the origin of electrical stimulation as a technique to increase muscle strength. As a matter of fact, electric stimulation has been used as a technique to improve

  1. Difficult Decisions: Chemical Warfare.

    Science.gov (United States)

    Slesnick, Irwin L.; Miller, John A.

    1988-01-01

    Gives the background history and chemistry of modern day chemical warfare from World War I to the present. Provides discussion questions to stimulate deeper thinking on the issue. Contains a discussion activity called "Can New Chemical Weapons Lead to Humane Warfare?" (CW)

  2. A comparative quantitative analysis of the IDEAL (iterative decomposition of water and fat with echo asymmetry and least-squares estimation) and the CHESS (chemical shift selection suppression) techniques in 3.0 T L-spine MRI

    Science.gov (United States)

    Kim, Eng-Chan; Cho, Jae-Hwan; Kim, Min-Hye; Kim, Ki-Hong; Choi, Cheon-Woong; Seok, Jong-min; Na, Kil-Ju; Han, Man-Seok

    2013-03-01

    This study was conducted on 20 patients who had undergone pedicle screw fixation between March and December 2010 to quantitatively compare a conventional fat suppression technique, CHESS (chemical shift selection suppression), and a new technique, IDEAL (iterative decomposition of water and fat with echo asymmetry and least squares estimation). The general efficacy and usefulness of the IDEAL technique was also evaluated. Fat-suppressed transverse-relaxation-weighed images and longitudinal-relaxation-weighted images were obtained before and after contrast injection by using these two techniques with a 1.5T MR (magnetic resonance) scanner. The obtained images were analyzed for image distortion, susceptibility artifacts and homogenous fat removal in the target region. The results showed that the image distortion due to the susceptibility artifacts caused by implanted metal was lower in the images obtained using the IDEAL technique compared to those obtained using the CHESS technique. The results of a qualitative analysis also showed that compared to the CHESS technique, fewer susceptibility artifacts and more homogenous fat removal were found in the images obtained using the IDEAL technique in a comparative image evaluation of the axial plane images before and after contrast injection. In summary, compared to the CHESS technique, the IDEAL technique showed a lower occurrence of susceptibility artifacts caused by metal and lower image distortion. In addition, more homogenous fat removal was shown in the IDEAL technique.

  3. From the coupling between ion beam analysis techniques and physico-chemical characterization methods to the study of irradiation effects on materials behaviour

    International Nuclear Information System (INIS)

    Millard-Pinard, N.

    2003-01-01

    The general purpose of my research work is to follow and to interpret the surface evolution of materials, which have received several treatments. During my PhD and my post-doc work, my field of research was tribology. Since I arrived in the 'Aval du Cycle Electronucleaire' group of the Institut de Physique Nucleaire de Lyon, my research activities are in line with the CNRS program 'PACE ' (Programme sur l'Aval du Cycle Electronucleaire) within the ACTINET network. They are coordinated by the PARIS (Physico-chimie des actinides et autres radioelements en solution et aux interfaces) and NOMADE (NOuveaux MAteriaux pour les DEchets) GDR with ANDRA (Agence Nationale pour la gestion des Dechets RAdioactifs), EDF and IRSN (Institut de Radioprotection et de Surete Nucleaire) as partner organisations. My work focused on the study of fission products and actinides migration in barrier materials, which may be capable of assuring the long term safety of deep geological repositories. Until now, it was necessary to use the coupling of ion beam analysis techniques and physico-chemical characterization techniques. During the last few months, I have became interested in understanding radiolytic effects. This new orientation has led us to use ion beams as an irradiating tool. These irradiation experiments are pursued in three major projects. The study of cobalt sulfide inhibition effects of radiolysis gas production during the irradiation of model organic molecules. This is a collaboration with the IRSN, the Institut de Recherche sur la Catalyse and the Ecole Nationale Superieure des Mines de Saint-Etienne. A PhD, co-directed by M. Pijolat from ENSMSE and myself, concerning this study will start in October 2003. Water radiolysis effects on iron corrosion are also studied in the particular case of vitrified nuclear waste containers, which will be stored in deep geological repositories. One ANDRA financed PhD, co-directed by Nathalie Moncoffre and myself, is dedicated to this study

  4. Enteral feeding without pancreatic stimulation

    DEFF Research Database (Denmark)

    Kaushik, Neeraj; Pietraszewski, Marie; Holst, Jens Juul

    2005-01-01

    OBJECTIVE: All forms of commonly practiced enteral feeding techniques stimulate pancreatic secretion, and only intravenous feeding avoids it. In this study, we explored the possibility of more distal enteral infusions of tube feeds to see whether activation of the ileal brake mechanism can result...

  5. Proceedings of the national seminar on significant advancements in plasma/flame/associated techniques and their applications in chemical characterisation of atomic minerals and materials: souvenir

    International Nuclear Information System (INIS)

    Chakrapani, G.; Premdas, A.; Bangroo, P.N.

    2013-01-01

    AAS techniques, novel decomposition methods, plasma techniques, separation, preconcentration, ICP-OPEs, ICP-OES/MS, ICP/other techniques, uranium, review articles and plasma techniques are some of the topics covered in this symposium. Papers relevant to INIS are indexed separately

  6. Ultra-thin silicon oxide layers on crystalline silicon wafers: Comparison of advanced oxidation techniques with respect to chemically abrupt SiO{sub 2}/Si interfaces with low defect densities

    Energy Technology Data Exchange (ETDEWEB)

    Stegemann, Bert, E-mail: bert.stegemann@htw-berlin.de [HTW Berlin - University of Applied Sciences, 12459 Berlin (Germany); Gad, Karim M. [University of Freiburg, Department of Microsystems Engineering - IMTEK, 79110 Freiburg (Germany); Balamou, Patrice [HTW Berlin - University of Applied Sciences, 12459 Berlin (Germany); Helmholtz Center Berlin for Materials and Energy (HZB), 12489 Berlin (Germany); Sixtensson, Daniel [Helmholtz Center Berlin for Materials and Energy (HZB), 12489 Berlin (Germany); Vössing, Daniel; Kasemann, Martin [University of Freiburg, Department of Microsystems Engineering - IMTEK, 79110 Freiburg (Germany); Angermann, Heike [Helmholtz Center Berlin for Materials and Energy (HZB), 12489 Berlin (Germany)

    2017-02-15

    Highlights: • Fabrication of ultrathin SiO{sub 2} tunnel layers on c-Si. • Correlation of electronic and chemical SiO{sub 2}/Si interface properties revealed by XPS/SPV. • Chemically abrupt SiO{sub 2}/Si interfaces generate less interface defect states considerable. - Abstract: Six advanced oxidation techniques were analyzed, evaluated and compared with respect to the preparation of high-quality ultra-thin oxide layers on crystalline silicon. The resulting electronic and chemical SiO{sub 2}/Si interface properties were determined by a combined x-ray photoemission (XPS) and surface photovoltage (SPV) investigation. Depending on the oxidation technique, chemically abrupt SiO{sub 2}/Si interfaces with low densities of interface states were fabricated on c-Si either at low temperatures, at short times, or in wet-chemical environment, resulting in each case in excellent interface passivation. Moreover, the beneficial effect of a subsequent forming gas annealing (FGA) step for the passivation of the SiO{sub 2}/Si interface of ultra-thin oxide layers has been proven. Chemically abrupt SiO{sub 2}/Si interfaces have been shown to generate less interface defect states.

  7. The study and the realization of radiation detectors made from polycrystalline diamond films grown by microwave plasma enhanced chemical vapour deposition technique

    International Nuclear Information System (INIS)

    Jany, Ch.

    1998-01-01

    The aim of this work was to develop radiation detectors made from polycrystalline diamond films grown by microwave plasma enhanced chemical vapour deposition technique. The influence of surface treatments, contact technology and diamond growth parameters on the diamond detectors characteristics was investigated in order to optimise the detector response to alpha particles. The first part of the study focused on the electrical behaviour of as-deposited diamond surface, showing a p type conduction and its influence on the leakage current of the device. A surface preparation process was established in order to reduce the leakage current of the device by surface dehydrogenation using an oxidising step. Several methods to form and treat electrical contacts were also investigated showing that the collection efficiency of the device decreases after contact annealing. In the second part, we reported the influence of the diamond deposition parameters on the characteristics of the detectors. The increase of the deposition temperature and/or methane concentration was shown to lead η to decrease. In contrast, η was found to increase with the micro-wave power. The evolution of the diamond detector characteristics results from the variation in sp 2 phases incorporation and in the crystallography quality of the films. These defects increase the leakage current and reduce the carrier mobility and lifetime. Measurements carried out on detectors with different thicknesses showed that the physical properties varies along the growth direction, improving with the film thickness. Finally, the addition of nitrogen (> 10 ppm) in the gas mixture during diamond deposition was found to strongly reduce the collection efficiency of the detectors. To conclude the study, we fabricated and characterised diamond devices which were used for thermal neutron detection and for the intensity and shape measurement of VUV and soft X-ray pulses. (author)

  8. Assessing the nutritional value of agroindustrial co-products and feed through chemical composition, in vitro digestibility, and gas production technique

    Directory of Open Access Journals (Sweden)

    Paula Martins Olivo

    2017-07-01

    Full Text Available Agroindustrial co-products are a viable alternative for use in animal nutrition. Tests were conducted using eight different types of co-products and feed to evaluate the chemical composition, in vitro digestibility of dry matter, crude protein and neutral detergent fiber, and gas production by them. The co-products tested were: coffee hulls; pelleted citrus pulp; grape residue; soybean hulls; cottonseed; cassava foliage; and foods usually supplied to ruminants: corn silage and ground corn concentrate. Data of in vitro digestibility of dry matter, crude protein and neutral detergent fiber were tested by analysis of variance using the least square method; the results of gas production were interpreted by a non-linear regression by the Gauss-Newton method; and the effects of treatments were evaluated by the Tukey’s test. The coefficients of in vitro digestibility of dry matter, crude protein and neutral detergent fiber of co-products were different. Gas production was also different between co-products and feeds evaluated for the volume of gas produced from the fast and slow degradation fractions, degradation rate, bacterial colonization time, and the total volume of gas produced. The evaluated co-products exhibited greater in vitro dry matter digestibility compared to corn silage, except for cottonseed, grape residue, and cassava foliage. Co-products showed higher values of in vitro crude protein digestibility compared to corn silage, and a reduced in vitro digestibility of neutral detergent fiber, except for pelleted citrus pulp and soybean hulls. Corn silage produced larger volume of gas from the fast degradation fraction compared to the co-products and corn concentrate. Co-products analyzed had appropriate nutritional characteristics according to the techniques applied and can be included in ruminant diets.

  9. Toward the first study of chemical reaction dynamics of Mu with vibrational-state-selected reactants in the gas phase: The Mu+H2*(v=1) reaction by stimulated Raman pumping

    International Nuclear Information System (INIS)

    Bakule, Pavel; Sukhorukov, Oleksandr; Matsuda, Yasuyuki; Pratt, Francis; Gumplinger, Peter; Momose, Takamasa; Torikai, Eiko; Fleming, Donald

    2009-01-01

    Stimulated Raman pumping (SRP) is used to produce H 2 in its first vibrational state, in order to measure, for the first time, the Mu+H 2 *(v=1)→MuH+H reaction rate at room temperature, as a prototypical example of new directions in gas-phase muonium chemistry, utilizing the pulsed muon beam and a new dedicated laser system at the RIKEN/RAL Laboratory. Reported here is a preliminary result but the final results are expected to provide definitive new tests of reaction rate theory on the highly accurate H 3 potential energy surface. The major difficulty in this experiment, compared to the standard SRP process, is to ensure a homogeneous excitation over a volume of several cm 3 and of sufficient intensity to ensure a measurable Mu relaxation rate. The techniques used to accomplish this are described. The experiment utilizes the 2nd harmonic output of a Nd:YAG laser (532 nm) with pulse energies up to 500 mJ at a repetition rate of 25 Hz. Different optical setups have been constructed and tested in order to optimize the number of laser-pumped H 2 molecules and their overlap with the stopping profile of the muon beam in the reaction cell (total volume ∼100x40x4mm 3 ). The first result of this experiment gives a measured relaxation rate due to laser excitation of λ*=0.085±0.051μs -1 , consistent with theory but limited by both low statistics and particularly a high background relaxation rate.

  10. Motor cortex stimulation: role of computer modeling

    NARCIS (Netherlands)

    Manola, L.; Holsheimer, J.; Sakas, D.E.; Simpson, B.A

    Motor cortex stimulation (MCS) is a promising clinical technique used to treat chronic, otherwise intractable pain. However, the mechanisms by which the neural elements that are stimulated during MCS induce pain relief are not understood. Neither is it known which neural elements (fibers (parallel

  11. Development of Femtosecond Stimulated Raman Spectroscopy: Stimulated Raman Gain via Elimination of Cross Phase Modulation

    International Nuclear Information System (INIS)

    Jin, Seung Min; Lee, Young Jong; Yu, Jong Wan; Kim, Seong Keun

    2004-01-01

    We have developed a new femtosecond probe technique by using stimulated Raman spectroscopy. The cross phase modulation in femtosecond time scale associated with off-resonant interaction was shown to be eliminated by integrating the transient gain/loss signal over the time delay between the Raman pump pulse and the continuum pulse. The stimulated Raman gain of neat cyclohexane was obtained to demonstrate the feasibility of the technique. Spectral and temporal widths of stimulated Raman spectra were controlled by using a narrow band pass filter. Femtosecond stimulated Raman spectroscopy was proposed as a highly useful probe in time-resolved vibrational spectroscopy

  12. EOR by stimulated microflora

    Energy Technology Data Exchange (ETDEWEB)

    Svarovskaya, L.I.; Altunina, L.K.; Rozhenkova, Z.A.; Bulavin, V.D. [Institute of Petroleum Chemistry, Tomsk (Russian Federation)

    1995-12-31

    A combined microbiological and physico-chemical method for EOR has been developed for flooded West Siberia oil fields with formation temperature of 45{degrees}-95{degrees}C (318-365K). Formation water includes rich and various biocenoses numbering up to 2 x 10{sup 7} cells per ml. Representatives of genera, i.e, Pseudomonas, Bacillus, Actinomyces, Micrococcus, Mycobacterium, Sarcina, etc. were found to be the most widely distributed microorganisms. The method is based on injection of systems exhibiting high oil displacing capacity and at the same time being an additional nitrous nutrient for endemic populations of microorganisms. Their injection into formation water favors biomass growth by 4-6 orders and promotes syntheses of biosurfactants, biopolymers, acids, etc., and gaseous products. The features of residual oil displacement have been studied on laboratory models using a combined microbiological and physico-chemical method. A curve for the yield of residual oil is presented by two peaks. The first peak is stipulated by the washing action of oil displacement system, and the second one by the effect of metabolites produced at stimulation of biogenic processes. Oil displacement index increases by 15%-30%.

  13. Bioorthogonal Chemical Imaging for Biomedicine

    Science.gov (United States)

    Min, Wei

    2017-06-01

    Innovations in light microscopy have tremendously revolutionized the way researchers study biological systems with subcellular resolution. Although fluorescence microscopy is currently the method of choice for cellular imaging, it faces fundamental limitations for studying the vast number of small biomolecules. This is because relatively bulky fluorescent labels could introduce considerable perturbation to or even completely alter the native functions of vital small biomolecules. Hence, despite their immense functional importance, these small biomolecules remain largely undetectable by fluorescence microscopy. To address this challenge, we have developed a bioorthogonal chemical imaging platform. By coupling stimulated Raman scattering (SRS) microscopy, an emerging nonlinear Raman microscopy technique, with tiny and Raman-active vibrational probes (e.g., alkynes, nitriles and stable isotopes including 2H and 13C), bioorthogonal chemical imaging exhibits superb sensitivity, specificity, multiplicity and biocompatibility for imaging small biomolecules in live systems including tissues and organisms. Exciting biomedical applications such as imaging fatty acid metabolism related to lipotoxicity, glucose uptake and metabolism, drug trafficking, protein synthesis, DNA replication, protein degradation, RNA synthesis and tumor metabolism will be presented. This bioorthogonal chemical imaging platform is compatible with live-cell biology, thus allowing real-time imaging of small-molecule dynamics. Moreover, further chemical and spectroscopic strategies allow for multicolor bioorthogonal chemical imaging, a valuable technique in the era of "omics". We envision that the coupling of SRS microscopy with vibrational probes would do for small biomolecules what fluorescence microscopy of fluorophores has done for larger molecular species, bringing small molecules under the illumination of modern light microscopy.

  14. New Approach to Evaluate the Antennal Response of an Adult Predator Insect to Different Volatile Chemical Compounds by using Electroantennogram Technique

    Science.gov (United States)

    Shonouda, Mourad L.

    The antennal response of adult syrphid flies to selected plant volatile chemical compounds was investigated in the present study. The main chemical classes and their chemical compounds were aldehydes (nonanal and benzaldehyde), monoterpene-alcohols (linalool and alpha-terpineol), ketones (6-methyl-5-heptene-2-one and 2-undecanone), hydrocarbons (tetradecane) and benzoids (methyl salicylate). Electroantennogram (EAG) records showed that the syrphid antennae were strongly responded to linalool, 6-methyl-5-heptene-2-one and methyl salicylate even at low concentrations, in addition to the high dose concentration of nonanal comparably to the other chemical compounds. The antennae of old syrphid adults were more responsive and elicited higher levels of responses to all compounds rather than young syrphid adults. The antennal sensitivity may differ from one compound to another according to the sex. The difference in responses could be attributed to the sensitivity of olfactory receptors and/or the characterization of binding protein(s). The quality of biocontrol agent could be improved if the chemical interaction between beneficial natural enemies and the surrounding environment is intensively studied and we clearly understand the chemical ecology of each natural enemy.

  15. Consensus paper: combining transcranial stimulation with neuroimaging

    DEFF Research Database (Denmark)

    Siebner, Hartwig R; Bergmann, Til O; Bestmann, Sven

    2009-01-01

    neuroimaging (online approach), TMS can be used to test how focal cortex stimulation acutely modifies the activity and connectivity in the stimulated neuronal circuits. TMS and neuroimaging can also be separated in time (offline approach). A conditioning session of repetitive TMS (rTMS) may be used to induce...... information obtained by neuroimaging can be used to define the optimal site and time point of stimulation in a subsequent experiment in which TMS is used to probe the functional contribution of the stimulated area to a specific task. In this review, we first address some general methodologic issues that need......In the last decade, combined transcranial magnetic stimulation (TMS)-neuroimaging studies have greatly stimulated research in the field of TMS and neuroimaging. Here, we review how TMS can be combined with various neuroimaging techniques to investigate human brain function. When applied during...

  16. A new digestion and chemical separation technique for rapid and highly reproducible determination of Lu/Hf and Hf isotope ratios in geological materials by mc-ICP-MS

    DEFF Research Database (Denmark)

    Bizzarro, Martin; Baker, J.A.; Ulfbeck, D.

    2003-01-01

    for isotopic analysis of the Sm-Nd system and/or the other HFSE (Ti, Zr). Total procedural blanks for this technique are 5 g) samples. We present data from replicate digestions of international rock reference materials which....... The relative simplicity of this technique, coupled with the ease of digestion (and samplespike equilibration) of large difficult-to-dissolve samples, and the speed (2 days) with which samples can be digested and processed through the chemical separation scheme makes it an attractive new method for preparing...

  17. Optically stimulated luminescence in retrospective dosimetry

    International Nuclear Information System (INIS)

    Boetter-Jensen, L.; Murray, A.S.

    2002-01-01

    Since the beginning of the 1990s the exploration of optically stimulated luminescence in retrospective accident dosimetry has driven an intensive investigation and development programme at Ris deg. into measurement facilities and techniques. This paper reviews some of the outcomes of this programme, including the evaluation of the single-aliquot regenerative-dose measurement protocol with brick quartz and the determination of dose-depth profiles in building materials as a guide to determining the mean energy of the incident radiation. Investigations into heated materials are most advanced, and a lower detection limit for quartz extracted from Chernobyl bricks was determined to be <10 mGy. The first results from the measurement of doses in unheated building materials such as mortar and concrete are also discussed. Both small-aliquot and single-grain techniques have been used to assess accident doses in these cement based building materials more commonly found in workplaces. Finally some results of a preliminary investigation of the OSL properties of household chemicals are discussed with reference to their potential as accident dosemeters. (author)

  18. Meeting on risk and monitoring analysis techniques for food safety - RLA/5/060/ARCAL Project (ARCAL CXXVIII): sampling plans and introduction to chemical risk assessment in food innocuousness

    International Nuclear Information System (INIS)

    2013-03-01

    Some of the Latinoamerican countries such us Bolivia, Colombia, Uruguay and Venezuela participant in the meeting gave an exposition about the risk analysis and monitoring techniques in food safety in their countyries. With the aim to study components of risk analysis, food innocuousness, evaluation and chemical dangers, toxicity, exposure, change of paradigms in the global food system, data sources, study in animals and in vitro, sensitivity analysis, risk assessment in health it carried out the meeting

  19. Evoked Electromyographically Controlled Electrical Stimulation

    Directory of Open Access Journals (Sweden)

    Mitsuhiro Hayashibe

    2016-07-01

    Full Text Available Time-variant muscle responses under electrical stimulation (ES are often problematic for all the applications of neuroprosthetic muscle control. This situation limits the range of ES usage in relevant areas, mainly due to muscle fatigue and also to changes in stimulation electrode contact conditions, especially in transcutaneous ES. Surface electrodes are still the most widely used in noninvasive applications.Electrical field variations caused by changes in the stimulation contact condition markedly affect the resulting total muscle activation levels. Fatigue phenomena under functional electrical stimulation (FES are also well known source of time-varying characteristics coming from muscle response under ES. Therefore it is essential to monitor the actual muscle state and assess the expected muscle response by ES so as to improve the current ES system in favour of adaptive muscle-response-aware FES control. To deal with this issue, we have been studying a novel control technique using evoked electromyography (eEMG signals to compensate for these muscle time-variances under ES for stable neuroprosthetic muscle control. In this perspective article, I overview the background of this topic and highlight important points to be aware of when using ES to induce the desired muscle activation regardless of the time-variance. I also demonstrate how to deal with the common critical problem of ES to move toward robust neuroprosthetic muscle control with the Evoked Electromyographically Controlled Electrical Stimulation paradigm.

  20. Decomposition techniques

    Science.gov (United States)

    Chao, T.T.; Sanzolone, R.F.

    1992-01-01

    Sample decomposition is a fundamental and integral step in the procedure of geochemical analysis. It is often the limiting factor to sample throughput, especially with the recent application of the fast and modern multi-element measurement instrumentation. The complexity of geological materials makes it necessary to choose the sample decomposition technique that is compatible with the specific objective of the analysis. When selecting a decomposition technique, consideration should be given to the chemical and mineralogical characteristics of the sample, elements to be determined, precision and accuracy requirements, sample throughput, technical capability of personnel, and time constraints. This paper addresses these concerns and discusses the attributes and limitations of many techniques of sample decomposition along with examples of their application to geochemical analysis. The chemical properties of reagents as to their function as decomposition agents are also reviewed. The section on acid dissolution techniques addresses the various inorganic acids that are used individually or in combination in both open and closed systems. Fluxes used in sample fusion are discussed. The promising microwave-oven technology and the emerging field of automation are also examined. A section on applications highlights the use of decomposition techniques for the determination of Au, platinum group elements (PGEs), Hg, U, hydride-forming elements, rare earth elements (REEs), and multi-elements in geological materials. Partial dissolution techniques used for geochemical exploration which have been treated in detail elsewhere are not discussed here; nor are fire-assaying for noble metals and decomposition techniques for X-ray fluorescence or nuclear methods be discussed. ?? 1992.

  1. Addictive drugs and brain stimulation reward.

    Science.gov (United States)

    Wise, R A

    1996-01-01

    Direct electrical or chemical stimulation of specific brain regions can establish response habits similar to those established by natural rewards such as food or sexual contact. Cocaine, mu and delta opiates, nicotine, phencyclidine, and cannabis each have actions that summate with rewarding electrical stimulation of the medial forebrain bundle (MFB). The reward-potentiating effects of amphetamine and opiates are associated with central sites of action where these drugs also have their direct rewarding effects, suggesting common mechanisms for drug reward per se and for drug potentiation of brain stimulation reward. The central sites at which these and perhaps other drugs of abuse potentiate brain stimulation reward and are rewarding in their own right are consistent with the hypothesis that the laboratory reward of brain stimulation and the pharmacological rewards of addictive drugs are habit forming because they act in the brain circuits that subserve more natural and biologically significant rewards.

  2. The Use of Atmospheric Pressure Chemical Ionization Mass Spectrometry with High Performance Liquid Chromatography and Other Separation Techniques for Identification of Triacylglycerols

    Czech Academy of Sciences Publication Activity Database

    Řezanka, Tomáš; Sigler, Karel

    2007-01-01

    Roč. 3, - (2007), s. 252-271 ISSN 1573-4110 R&D Projects: GA ČR GA203/06/0219 Institutional research plan: CEZ:AV0Z50200510 Keywords : triacylglycerols * atmospheric presssure chemical ionization * mass spectrometry Subject RIV: EE - Microbiology, Virology Impact factor: 1.815, year: 2007

  3. Different scale experimental techniques to approach the problem of substances generated in the loss of control of chemical systems: a study on ethyl diazoacetate decomposition

    NARCIS (Netherlands)

    Marsanich, K.; Barontini, F.; Cozzani, V.; Creemers, A.F.L.; Kersten, R.J.A.

    2004-01-01

    Article 2 of European Community Directive 96/82/EC (known as 'Seveso-II' Directive) also requires consideration in the plant inventory of the dangerous substances 'which it is believed may be generated in the loss of control of an industrial chemical process'. The present study was directed to the

  4. Optical stimulated luminescence (OSL) dating

    International Nuclear Information System (INIS)

    Banerjee, D.

    1999-01-01

    Since the pioneering work by Huntley et al. (1985), optical dating is being increasingly recognised as an important technique for establishing a time frame of deposition of sediments (Aitken, 1998). Optical dating differs from thermoluminescence (TL) dating in that visible/infrared light from lasers or LEDs (light-emitting-diodes) is used as a means of stimulation, in contrast to thermal stimulation. It has several advantages over TL dating: (i) the resetting of the OSL (optically stimulated luminescence) clock is more effective than that of TL clock; for sediments transported under water or in other situations where the sediment grains have undergone inhomogeneous bleaching, this property ensures that ages based on optical dating are generally more reliable than TL ages, (ii) the optical dating technique is non-destructive, and multiple readouts of the optical signal is possible; this feature has resulted in the development of single-aliquot and single-grain protocols (Murray and Wintle, 1999; Banerjee et al. 1999), (iii) the sample is not heated as in TL; thus, spurious luminescence is avoided and there is a significant reduction in blackbody radiation. Dating of materials which change phase on heating is also practical, and finally, (iv) thermal quenching of luminescence is negligible, allowing accurate estimation of kinetic parameters using standard techniques and providing access to deep OSL traps. This characteristic may be helpful in extending the limits of optical dating beyond the last 150 ka from a global point of view

  5. Spinal cord stimulation

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007560.htm Spinal cord stimulation To use the sharing features on this page, please enable JavaScript. Spinal cord stimulation is a treatment for pain that uses ...

  6. Feldspar, Infrared Stimulated Luminescence

    DEFF Research Database (Denmark)

    Jain, Mayank

    2014-01-01

    This entry primarily concerns the characteristics and the origins of infrared-stimulated luminescence in feldspars.......This entry primarily concerns the characteristics and the origins of infrared-stimulated luminescence in feldspars....

  7. Growth hormone stimulation test

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003377.htm Growth hormone stimulation test To use the sharing features on this page, please enable JavaScript. The growth hormone (GH) stimulation test measures the ability of ...

  8. Application of fisheries management techniques to assessing impacts: task I report. [Assessment of chemical, radiological, and thermal impacts of nuclear power plants on fish populations

    Energy Technology Data Exchange (ETDEWEB)

    McKenzie, D.H.; Baker, K.S.; Fickeisen, D.H.; Metzger, R.M.; Skalski, J.R.

    1979-03-01

    Task I efforts examined the available fisheries management techniques and assessed their potential application in a confirmatory monitoring program. The objective of such monitoring programs is to confirm that the prediction of an insignificant impact (usually made in the FES) was correct. Fisheries resource managers have developed several tools for assessing the fish population response to stress (exploitation) and they were thought potentially useful for detecting nuclear power plant impacts. Techniques in three categories were examined; catch removal, population dynamics, and nondestructive censuses, and the report contains their description, examples of application, advantages, and disadvantages. The techniques applied at nuclear power plant sites were examined in detail to provide information on implementation and variability of specific approaches. The most suitable techniques to incorporate into a monitoring program confirming no impact appear to be those based on Catch Per Unity Effort (CPUE) and hydroacoustic data. In some specific cases, age and growth studies and indirect census techniques may be beneficial. Recommendations for task II efforts to incorporate these techniques into monitoring program designs are presented. These include development of guidelines for; (1) designing and implementing a data collection program; (2) interpreting these data and assessing the occurrence of impact, and (3) establishment of the monitoring program's ability to detect changes in the affected populations.

  9. Optical stimulation of peripheral nerves in vivo

    Science.gov (United States)

    Wells, Jonathon D.

    This dissertation documents the emergence and validation of a new clinical tool that bridges the fields of biomedical optics and neuroscience. The research herein describes an innovative method for direct neurostimulation with pulsed infrared laser light. Safety and effectiveness of this technique are first demonstrated through functional stimulation of the rat sciatic nerve in vivo. The Holmium:YAG laser (lambda = 2.12 mum) is shown to operate at an optimal wavelength for peripheral nerve stimulation with advantages over standard electrical neural stimulation; including contact-free stimulation, high spatial selectivity, and lack of a stimulation artifact. The underlying biophysical mechanism responsible for transient optical nerve stimulation appears to be a small, absorption driven thermal gradient sustained at the axonal layer of nerve. Results explicitly prove that low frequency optical stimulation can reliably stimulate without resulting in tissue thermal damage. Based on the positive results from animal studies, these optimal laser parameters were utilized to move this research into the clinic with a combined safety and efficacy study in human subjects undergoing selective dorsal rhizotomy. The clinical Holmium:YAG laser was used to effectively stimulate human dorsal spinal roots and elicit functional muscle responses recorded during surgery without evidence of nerve damage. Overall these results predict that this technology can be a valuable clinical tool in various neurosurgical applications.

  10. Improvement of the preparation processes of oligoalginate by irradiation method combining with proper chemical treatment and applying the products on vegetables grown by hydroponics techniques

    International Nuclear Information System (INIS)

    Nguyen Huynh Phuong Uyen; Le Quang Luan; Le Thi Thuy Trang; Nguyen Thi Vang; Vo Thi Thu Ha; To Van Loi; Nguyen Hong An

    2015-01-01

    Degraded alginate extracted from brown seaweed compounds with molecular weights of 14.5 kDa was obtained by the Co-60 gamma ray irradiation at the absorbed dose of 5 kGy in presence of 0.5% H_2O_2. It was observed that the obtained oligo alginate promoted the growth of mustard greens and lettuce at an optimal concentration of 75 ppm and stimulated the plant height, root length, fresh biomass and dried matter content of the tested vegetables. The oligoalginate prepared by the irradiation under the presence of hydrogen peroxide showed growth promotion effects in the same level as the oligoalginate prepared by only irradiation. Note that the oligoalginate exhibited as a potential, safety and high effective product for plant growth promoter. (author)

  11. Fiber-reinforced ceramic matrix composites processed by a hybrid technique based on chemical vapor infiltration, slurry impregnation and spark plasma sintering

    International Nuclear Information System (INIS)

    Magnant, J.; Pailler, R.; Le Petitcorps, Y.; Maille, L.; Guette, A.; Marthe, J.

    2013-01-01

    Fabrication of multidirectional continuous carbon and silicon carbide fiber reinforced ceramic matrix composites (CMC) by a new short time hybrid process was studied. This process is based, first, on the deposition of fiber interphase and coating by chemical vapor infiltration, next, on the introduction of silicon nitride powders into the fibrous preform by slurry impregnation and, finally, on the densification of the composite by liquid phase spark plasma sintering (LP-SPS). The homogeneous introduction of the ceramic charges into the multidirectional fiber pre-forms was realized by slurry impregnation from highly concentrated and well-dispersed aqueous colloid suspensions. The chemical degradation of the carbon fibers during the fabrication was prevented by adapting the sintering pressure cycle. The composites manufactured are dense. Microstructural analyses were conducted to explain the mechanical properties achieved. One main important result of this study is that LP-SPS can be used in some hybrid processes to densify fiber reinforced CMC. (authors)

  12. An Innovative Approach to Balancing Chemical-Reaction Equations: A Simplified Matrix-Inversion Technique for Determining The Matrix Null Space

    OpenAIRE

    Thorne, Lawrence R.

    2011-01-01

    I propose a novel approach to balancing equations that is applicable to all chemical-reaction equations; it is readily accessible to students via scientific calculators and basic computer spreadsheets that have a matrix-inversion application. The new approach utilizes the familiar matrix-inversion operation in an unfamiliar and innovative way; its purpose is not to identify undetermined coefficients as usual, but, instead, to compute a matrix null space (or matrix kernel). The null space then...

  13. Dual-directional regulation of drug permeating amount by combining the technique of ion-pair complexation with chemical enhancers for the synchronous permeation of indapamide and bisoprolol in their compound patch through rabbit skin.

    Science.gov (United States)

    Song, Wenting; Cun, Dongmei; Quan, Peng; Liu, Nannan; Chen, Yang; Cui, Hongxia; Xiang, Rongwu; Fang, Liang

    2015-04-01

    To achieve the synchronous skin permeation of indapamide (IND) and bisoprolol (BSP) in their compound patch, the techniques of ion-pair complexation and chemical enhancers were combined to dual-directionally regulate drug permeating amounts. Ion-pair complexes of BSP and various organic acids were formed by the technique of ion-pair complexation. Among the complexes formed, bisoprolol tartrate (BSP.T) down-regulated the permeating amount of BSP to the same extent as that of IND. Then, to simultaneously up-regulate the amounts of the two drugs, an enhancer combination of 15.8% Span80 (SP), 6.0% Azone (AZ) and 2.2% N-methyl pyrrolidone (NMP) was obtained by central composite design and exhibited an outstanding and simultaneous enhancement on IND and BSP with enhancing ratio (ER) of 4.52 and 3.49, respectively. The effect of the dual-directional regulation was evaluated by in vitro permeation experiments and in vivo pharmacokinetic studies. For IND and BSP, their observed permeation profiles were comparable and their MAT (mean absorption time) showed no significant difference, which both demonstrated these two drugs achieved the synchronous skin permeation in their compound patch by the dual-directional regulation strategy of combining the technique of ion-pair complexation with chemical enhancers. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Chemical Peels

    Science.gov (United States)

    ... care Kids’ zone Video library Find a dermatologist Chemical peels Overview Chemical peels: Overview Also called chemexfoliation , derma peeling Do ... Overview Chemical peels: FAQs Chemical peels: Preparation FAQs Chemical peels: FAQs To help you decide whether this ...

  15. CHEMICAL PROFILES OF HONEYS ORIGINATING FROM DIFFERENT FLORAL SOURCES AND GEOGRAPHIC LOCATIONS EXAMINED BY A COMBINATION OF THREE EXTRACTION AND ANALYSIS TECHNIQUES

    Directory of Open Access Journals (Sweden)

    D. M. Meloncelli

    2015-05-01

    Full Text Available The chemical profiles of Tasmanian Leatherwood and Manuka honeys from Tasmania and New Zealand have been compared by a combination of GC-MS analysis of volatiles and semi-volatiles, RP-HPLC-DAD analysis of phenolics and flavonoids and HPLC-DAD analysis of derivatised dihydroxyacetone, hydroxymethylfurfural and methylglyoxal. This study found that Tasmanian and New Zealand Manuka honeys have high concentrations of methylglyoxal. However, syringic acid was only detected in Manuka honeys grown in New Zealand. The Tasmanian honeys can be distinguished by the higher concentration of 3-phenyllactic acid in Manuka compared to Leatherwood floral sources.

  16. CHEMICAL PROFILES OF HONEYS ORIGINATING FROM DIFFERENT FLORAL SOURCES AND GEOGRAPHIC LOCATIONS EXAMINED BY A COMBINATION OF THREE EXTRACTION AND ANALYSIS TECHNIQUES

    Directory of Open Access Journals (Sweden)

    D. M. Meloncelli,

    2015-02-01

    Full Text Available The chemical profiles of Tasmanian Leatherwood and Manuka honeys from Tasmania and New Zealand have been compared by a combination of GC-MS analysis of volatiles and semi-volatiles, RP-HPLC-DAD analysis of phenolics and flavonoids and HPLC-DAD analysis of derivatised dihydroxyacetone, hydroxymethylfurfural and methylglyoxal. This study found that Tasmanian and New Zealand Manuka honeys have high concentrations of methylglyoxal. However, syringic acid was only detected in Manuka honeys grown in New Zealand. The Tasmanian honeys can be distinguished by the higher concentration of 3-phenyllactic acid in Manuka compared to Leatherwood floral sources.

  17. Performance Enhancement by Brain Stimulation

    Directory of Open Access Journals (Sweden)

    Parisa Gazerani

    2017-09-01

    Full Text Available Number of substances and strategies are available to increase performance in sport (Catlin and Murray, 1996. Since 2004, the World Anti-Doping Agency (WADA posts an updated list of substances and methods prohibited to athletes. Drugs (e.g., steroids, stimulants are a major part of this list; however, technologies and methods (e.g., gene doping are increasingly being identified and added (WADA, 2017. Among technologies and methods that might exert a potential effect on athletic performance, brain stimulation has recently been subjected to extensive discussion. Neuro-enhancement for doping purposes has been termed “neurodoping” in the literature (Davis, 2013; however, this concept needs further documentation before the term “neurodoping” can be used properly. Two major non-invasive techniques of brain stimulations are transcranial magnetic stimulation (TMS (Hallett, 2007; Rossi et al., 2009, and transcranial direct current stimulation (tDCS (Stagg and Nitsche, 2011. In TMS, an electric coil held over the head applies magnetic pulses to create currents in the brain. In tDCS, a low, continuous electrical current is delivered to the brain by using surface electrodes attached on the scalp. TMS and tDCS have been used in both research and clinic (Shin and Pelled, 2017 for example to examine alterations in cognitive function or motor skills or to assist in recovering motor function after a stroke (Gomez Palacio Schjetnan et al., 2013 or reducing fatigue in patients with multiple sclerosis (Saiote et al., 2014. In an opinion paper, it was proposed that use of emerging brain stimulation techniques might also enhance physical and mental performance in sports (Davis, 2013. The assumption was based on several reports. For example some studies have shown that TMS could shorten reaction times to visual, auditory and touch stimuli, reduce tremor, and enhance the acquisition of complex motor skills. Based on the current evidence, a recent review (Colzato

  18. Research and development on chemical reactors made of industrial structural materials and hydriodic acid concentration technique for thermochemical hydrogen production IS process

    International Nuclear Information System (INIS)

    Kubo, Shinji; Iwatsuki, Jin; Takegami, Hiroaki; Kasahara, Seiji; Tanaka, Nobuyuki; Noguchi, Hiroki; Kamiji, Yu; Onuki, Kaoru

    2015-10-01

    Japan Atomic Energy Agency has been conducting a study on IS process for thermochemical hydrogen production in order to develop massive hydrogen production technology for hydrogen society. Integrity of the chemical reactors and concentration technology of hydrogen iodide in HIx solution were studied. In the former study, the chemical reactors were trial-fabricated using industrial materials. A test of 30 times of thermal cycle test under circulating condition of the Bunsen reaction solution showed integrity of the Bunsen reactor made of fluororesin lined steel. Also, 100 hours of reaction tests showed integrity of the sulfuric acid decomposer made of silicon carbide and of the hydrogen iodide decomposer made of Hastelloy C-276. In the latter study, concerning electro-electrodialysis using cation-exchange membrane, sulfuric acid in the anolyte had little influence on the concentration performance. These results suggest the purification system of HIx solution can be simplified. Based on the Nernst-Planck equation and the Smoluchowski equation, proton transport number, water permeance, and IR drop of the cation exchange membrane were formulated. The derived equations enable quantitative estimation for the performance indexes of Nafion ® membrane and, also, of ETFE-St membranes made by radiation-induced graft polymerization method. (author)

  19. Towards a Switched-Capacitor Based Stimulator for Efficient Deep-Brain Stimulation

    Science.gov (United States)

    Vidal, Jose; Ghovanloo, Maysam

    2013-01-01

    We have developed a novel 4-channel prototype stimulation circuit for implantable neurological stimulators (INS). This Switched-Capacitor based Stimulator (SCS) aims to utilize charge storage and charge injection techniques to take advantage of both the efficiency of conventional voltage-controlled stimulators (VCS) and the safety and controllability of current-controlled stimulators (CCS). The discrete SCS prototype offers fine control over stimulation parameters such as voltage, current, pulse width, frequency, and active electrode channel via a LabVIEW graphical user interface (GUI) when connected to a PC through USB. Furthermore, the prototype utilizes a floating current sensor to provide charge-balanced biphasic stimulation and ensure safety. The stimulator was analyzed using an electrode-electrolyte interface (EEI) model as well as with a pair of pacing electrodes in saline. The primary motivation of this research is to test the feasibility and functionality of a safe, effective, and power-efficient switched-capacitor based stimulator for use in Deep Brain Stimulation. PMID:21095987

  20. Effect of different drying techniques on flowability characteristics and chemical properties of natural carbohydrate-protein Gum from durian fruit seed

    Directory of Open Access Journals (Sweden)

    Mirhosseini Hamed

    2013-01-01

    Full Text Available Abstract Background A natural carbohydrate biopolymer was extracted from the agricultural biomass waste (durian seed. Subsequently, the crude biopolymer was purified by using the saturated barium hydroxide to minimize the impurities. Finally, the effect of different drying techniques on the flow characteristics and functional properties of the purified biopolymer was investigated. The present study elucidated the main functional characteristics such as flow characteristics, water- and oil-holding capacity, solubility, and foaming capacity. Results In most cases except for oven drying, the bulk density decreased, thus increasing the porosity. This might be attributed to the increase in the inter-particle voids of smaller sized particles with larger contact surface areas per unit volume. The current study revealed that oven-dried gum and freeze-dried gum had the highest and lowest compressibility index, thus indicating the weakest and strongest flowability among all samples. In the present work, the freeze-dried gum showed the lowest angle of repose, bulk, tapped and true density. This indicates the highest porosity degree of freeze dried gum among dried seed gums. It also exhibited the highest solubility, and foaming capacity thus providing the most desirable functional properties and flow characteristics among all drying techniques. Conclusion The present study revealed that freeze drying among all drying techniques provided the most desirable functional properties and flow characteristics for durian seed gum.

  1. Chemical Waste Management and Disposal.

    Science.gov (United States)

    Armour, Margaret-Ann

    1988-01-01

    Describes simple, efficient techniques for treating hazardous chemicals so that nontoxic and nonhazardous residues are formed. Discusses general rules for management of waste chemicals from school laboratories and general techniques for the disposal of waste or surplus chemicals. Lists specific disposal reactions. (CW)

  2. Somato stimulation and acupuncture therapy.

    Science.gov (United States)

    Zhao, Jing-Jun; Rong, Pei-Jing; Shi, Li; Ben, Hui; Zhu, Bing

    2016-05-01

    Acupuncture is an oldest somato stimulus medical technique. As the most representative peripheral nerve stimulation therapy, it has a complete system of theory and application and is applicable to a large population. This paper expounds the bionic origins of acupuncture and analyzes the physiological mechanism by which acupuncture works. For living creatures, functionally sound viscera and effective endurance of pain are essential for survival. This paper discusses the way in which acupuncture increases the pain threshold of living creatures and the underlying mechanism from the perspective of bionics. Acupuncture can also help to adjust visceral functions and works most effectively in facilitating the process of digestion and restraining visceral pain. This paper makes an in-depth overview of peripheral nerve stimulation therapy represented by acupuncture. We look forward to the revival of acupuncture, a long-standing somato stimulus medicine, in the modern medical systems.

  3. Femtosecond Broadband Stimulated Raman Spectroscopy

    International Nuclear Information System (INIS)

    Lee, Soo-Y; Yoon, Sagwoon; Mathies, Richard A

    2006-01-01

    Femtosecond broadband stimulated Raman spectroscopy (FSRS) is a new technique where a narrow bandwidth picosecond Raman pump pulse and a red-shifted broadband femtosecond Stokes probe pulse (with or without time delay between the pulses) act on a sample to produce a high resolution Raman gain spectrum with high efficiency and speed, free from fluorescence background interference. It can reveal vibrational structural information and dynamics of stationary or transient states. Here, the quantum picture for femtosecond broadband stimulated Raman spectroscopy (FSRS) is used to develop the semiclassical coupled wave theory of the phenomenon and to derive an expression for the measurable Raman gain in FSRS. The semiclassical theory is applied to study the dependence of lineshapes in FSRS on the pump-probe time delay and to deduce vibrational dephasing times in cyclohexane in the ground state

  4. Cortical stimulation and neuropathic pain

    Directory of Open Access Journals (Sweden)

    Cristiane Cagnoni Ramos

    2015-02-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2015v28n2p1 This paper is a review of physiological and behavioral data on motor cortex stimulation (MCS and its role in persistent neuropathic pain. MCS has been widely used in clinical medicine as a tool for the management of pain that does not respond satisfactorily to any kind of conventional analgesia. Some important mechanisms involved in nociceptive modulation still remains unclear. The aim of this study was to describe the mechanisms involved in neuropathic pain and introduce the effectiveness of electrical stimulation of the motor cortex used in the treatment of this disease. The ascending pain pathways are activated by peripheral receptors, in which there is the transduction of a chemical, physical or mechanical stimulus as a nerve impulse, where this impulse is transmitted to the dorsal horn of the spinal cord, which connects with second-order neurons and ascends to different locations in the central nervous system where the stimulus is perceived as pain. Because MCS has been proved to modulate this pathway in the motor cortex, it has been studied to mimic its effects in clinical practice and improve the treatments used for chronic pain. MCS has gained much attention in recent years due to its action in reversing chronic neuropathic pain, this being more effective than electrical stimulation at different locations and related pain nuclei.

  5. Cortical stimulation and neuropathic pain

    Directory of Open Access Journals (Sweden)

    Cristiane Cagnoni Ramos

    2015-05-01

    Full Text Available This paper is a review of physiological and behavioral data on motor cortex stimulation (MCS and its role in persistent neuropathic pain. MCS has been widely used in clinical medicine as a tool for the management of pain that does not respond satisfactorily to any kind of conventional analgesia. Some important mechanisms involved in nociceptive modulation still remains unclear. The aim of this study was to describe the mechanisms involved in neuropathic pain and introduce the effectiveness of electrical stimulation of the motor cortex used in the treatment of this disease. The ascending pain pathways are activated by peripheral receptors, in which there is the transduction of a chemical, physical or mechanical stimulus as a nerve impulse, where this impulse is transmitted to the dorsal horn of the spinal cord, which connects with second-order neurons and ascends to different locations in the central nervous system where the stimulus is perceived as pain. Because MCS has been proved to modulate this pathway in the motor cortex, it has been studied to mimic its effects in clinical practice and improve the treatments used for chronic pain. MCS has gained much attention in recent years due to its action in reversing chronic neuropathic pain, this being more effective than electrical stimulation at different locations and related pain nuclei.

  6. High frequency oscillations evoked by peripheral magnetic stimulation.

    Science.gov (United States)

    Biller, S; Simon, L; Fiedler, P; Strohmeier, D; Haueisen, J

    2011-01-01

    The analysis of somatosensory evoked potentials (SEP) and / or fields (SEF) is a well-established and important tool for investigating the functioning of the peripheral and central human nervous system. A standard technique to evoke SEPs / SEFs is the stimulation of the median nerve by using a bipolar electrical stimulus. We aim at an alternative stimulation technique enabling stimulation of deep nerve structures while reducing patient stress and error susceptibility. In the current study, we apply a commercial transcranial magnetic stimulation system for peripheral magnetic stimulation of the median nerve. We compare the results of simultaneously recorded EEG signals to prove applicability of our technique to evoke SEPs including low frequency components (LFC) as well as high frequency oscillations (HFO). Therefore, we compare amplitude, latency and time-frequency characteristics of the SEP of 14 healthy volunteers after electric and magnetic stimulation. Both low frequency components and high frequency oscillations were detected. The HFOs were superimposed onto the primary cortical response N20. Statistical analysis revealed significantly lower amplitudes and increased latencies for LFC and HFO components after magnetic stimulation. The differences indicate the inability of magnetic stimulation to elicit supramaximal responses. A psycho-perceptual evaluation showed that magnetic stimulation was less unpleasant for 12 out of the 14 volunteers. In conclusion, we showed that LFC and HFO components related to median nerve stimulation can be evoked by peripheral magnetic stimulation.

  7. dependent/calmodulin- stimulated protein kinase from moss

    Indian Academy of Sciences (India)

    Unknown

    stimulated protein kinase; CDPK, calmodulin domain-like protein kinase; KM14, 14 amino acid synthetic peptide; .... used were obtained from Sigma Chemical Company, USA, ..... Plant chimeric Ca2+/Calmodulin-dependent protein kinase.

  8. Zero bias thermally stimulated currents in synthetic diamond

    Science.gov (United States)

    Mori, R.; Miglio, S.; Bruzzi, M.; Bogani, F.; De Sio, A.; Pace, E.

    2009-06-01

    Zero bias thermally stimulated currents (ZBTSCs) have been observed in single crystal high pressure high temperature (HPHT) and polycrystalline chemical vapor deposited (pCVD) diamond films. The ZBTSC technique is characterized by an increased sensitivity with respect to a standard TSC analysis. Due to the absence of the thermally activated background current, new TSC peaks have been observed in both HPHT and pCVD diamond films, related to shallow activation energies usually obscured by the emission of the dominant impurities. The ZBTSC peaks are explained in terms of defect discharge in the nonequilibrium potential distribution created by a nonuniform traps filling at the metal-diamond junctions. The electric field due to the charged defects has been estimated in a quasizero bias TSC experiment by applying an external bias.

  9. Combining X-ray Absorption and X-ray Diffraction Techniques for in Situ Studies of Chemical Transformations in Heterogeneous Catalysis: Advantages and Limitations

    International Nuclear Information System (INIS)

    Frenkel, A.I.; Hanson, J.; Wang, Q.; Marinkovic, N.; Chen, J.G.; Barrio, L.; Si, R.; Lopez Camara, A.; Estrella, A.M.; Rodriguez, J.A.

    2011-01-01

    Recent advances in catalysis instrumentations include synchrotron-based facilities where time-resolved X-ray scattering and absorption techniques are combined in the same in situ or operando experiment to study catalysts at work. To evaluate the advances and limitations of this method, we performed a series of experiments at the new XAFS/XRD instrument in the National Synchrotron Light Source. Nearly simultaneous X-ray diffraction (XRD) and X-ray absorption fine-structure (XAFS) measurements of structure and kinetics of several catalysts under reducing or oxidizing conditions have been performed and carefully analyzed. For CuFe 2 O 4 under reducing conditions, the combined use of the two techniques allowed us to obtain accurate data on kinetics of nucleation and growth of metallic Cu. For the inverse catalyst CuO/CeO 2 that underwent isothermal reduction (with CO) and oxidation (with O 2 ), the XAFS data measured in the same experiment with XRD revealed strongly disordered Cu species that went undetected by diffraction. These and other examples emphasize the unique sensitivity of these two complementary methods to follow catalytic processes in the broad ranges of length and time scales.

  10. Investigation on the chemically fixing technique of carbon dioxide utilizing solar energy; Taiyo energy riyo ni yoru nisanka tanso no kagakuteki koteika gijutsu ni kansuru chosa

    Energy Technology Data Exchange (ETDEWEB)

    1993-03-01

    This report describes the results of effective fixing technique of CO2 by utilizing solar energy. First of all, the investigation was directed to the technique for synthesizing ethylene, hydrocarbons and alcohol by electrochemical reduction of CO2. The power required for this process is supplied by photovoltaic power generation. Development of excellent electrode catalyst is needed because the reduction of CO2 requires a high overvoltage. It is desirable to enhance the selectivity of the reaction for specific material and improve the transport process in the electrolytic cell. Next, designing of material and reaction of photocatalysts using semiconductor electrode and semiconductor particulate was examined. A semiconductor electrode made of FeS2 is inexpensive and has a high ability of collecting solar light. In the category of photocatalysis system, a photocatalytic system in which semiconductor particles are embedded in vesicle and a photpocatalyst based on potassium niobate are noteworthy. As biosystem, the method of reducing CO2 by calcareous algae which simultaneously advances fixing and calcification of CO2 by photosynthesis is noteworthy. 129 refs., 45 figs., 20 tabs.

  11. Development of method to chemical separation of gallium-67 by thermal diffusion technique; Desenvolvimento de metodo para separacao quimica de galio-67 pela tecnica de difusao termica

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Patricia de Andrade

    2012-07-01

    Radioisotopes of gallium have been studied and evaluated for medical applications since 1949. Over the past 50 years {sup 67}Ga has been widely used in the diagnosis of various diseases, including acute and chronic inflammatory lesions, bacterial or sterile and several types of tumors. In Brazil 30% of clinics that provide services for Nuclear Medicine use {sup 67}Ga citrate and the demand for 67{sup G}a at IPEN-CNEN/SP is 37 GBq (1 Ci)/week. The {sup 67}Ga presents physical half-life of 3.26 days (78 hours) and decays 100% by electron capture to stable {sup 67}Zn. Its decay includes the emission of {gamma} rays with energies of 93.3 keV (37%), 184.6 keV (20.4%), 300.2 keV (16.6%) and 888 keV (26%). In the past {sup 67}Ga was produced by the reaction {sup 68}Zn (p, 2n) {sup 67}Ga at IPEN-CNEN/SP. After irradiation, the target was dissolved in concentrated HCl and the solution percolated through a cationic resin DOWEX 50W-X8, 200-400 mesh, conditioned with 10 mol L{sup -1} HCl. Zinc, nickel and copper were eluted in 10 mol L{sup -1} HCl and {sup 67}Ga 3.5 mol L{sup -1} HCl. The final product was obtained as {sup 67}Ga citrate. This work presents a new, fast, direct and efficient method for the chemical separation of 67{sup G}a by thermal diffusion (heating of the target) combined with concentrated acetic acid extraction. Purification was performed by ion exchange chromatography. Natural zinc electrodeposition was performed on nickel/copper plates as substrate and the zinc deposits were adherent to the substrate, slightly shiny and uniform. The targets were irradiated with 26 MeV protons and integrated current of 10 {mu}A.h. After irradiation, the targets were heated at 300 deg C for 2 hours and placed in contact with concentrated acetic acid for 1 hour. The average yield of extraction of {sup 67}Ga was (72 {+-} 10)%. This solution was evaporated and the residue was taken up in 0.5 mol L{sup -1} NH{sub 4}OH. The 67{sup G}a was purified on cationic resin Dowex 50WX8

  12. Applying Data Mining Techniques to Chemical Analyses of Pre-drill Groundwater Samples within the Marcellus Formation Shale Play in Bradford County, Pennsylvania

    Science.gov (United States)

    Wen, T.; Niu, X.; Gonzales, M. S.; Li, Z.; Brantley, S.

    2017-12-01

    Groundwater samples are collected for chemical analyses by shale gas industry consultants in the vicinity of proposed gas wells in Pennsylvania. These data sets are archived so that the chemistry of water from homeowner wells can be compared to chemistry after gas-well drilling. Improved public awareness of groundwater quality issues will contribute to designing strategies for both water resource management and hydrocarbon exploration. We have received water analyses for 11,000 groundwater samples from PA Department of Environmental Protection (PA DEP) in the Marcellus Shale footprint in Bradford County, PA for the years ranging from 2010 to 2016. The PA DEP has investigated these analyses to determine whether gas well drilling or other activities affected water quality. We are currently investigating these analyses to look for patterns in chemistry throughout the study area (related or unrelated to gas drilling activities) and to look for evidence of analytes that may be present at concentrations higher than the advised standards for drinking water. Our preliminary results reveal that dissolved methane concentrations tend to be higher along fault lines in Bradford County [1]. Lead (Pb), arsenic (As), and barium (Ba) are sometimes present at levels above the EPA maximum contaminant level (MCL). Iron (Fe) and manganese (Mn) more frequently violate the EPA standard. We find that concentrations of some chemical analytes (e.g., Ba and Mn) are dependent on bedrock formations (i.e., Catskill vs. Lock Haven) while concentrations of other analytes (e.g., Pb) are not statistically significantly distinct between different bedrock formations. Our investigations are also focused on looking for correlations that might explain water quality patterns with respect to human activities such as gas drilling. However, percentages of water samples failing EPA MCL with respect to Pb, As, and Ba have decreased from previous USGS and PSU studies in the 1990s and 2000s. Public access to

  13. Determination of nitrate pollution sources by using isotopes and hydro-chemical techniques in the shallow Aquifer of Bara basin Northern Kordofan State Sudan

    International Nuclear Information System (INIS)

    Alamien, S. A. A.

    2010-10-01

    This study investigates the nature of the nitrate concentration and its effect on the quality of groundwater in the Bara basin in North Kordofan State Sudan. The principal objective of this study is to: detect possible NO 3 sources affecting groundwater quality. The δ 15 N results included two range of values, which suggested two different nitrogen sources in different parts of the study area. The data used in this study includes lithological logs, pumping and recovery data and chemical analysis. Rock ware, surfer, aquitest and aquichem software programs were used to analyze the data. which is the based on the lithological logs from nine shallow wells and seven deep boreholes. The geological formation was found to be the Umm Ruwaba formation which consists of two aquifers an upper shallow one and the other deep aquifer. The transmissivity of the upper aquifer was found to be 0.528m 2 / day, which is good and the average of hydraulic conductivity was found to be 0.08 4 m/ day, which is high and the storativity is 0.08 1 . The direction of flow of groundwater was found to be from North West to North East over all the area. Chemical analysis showed that the TDS concentration in the study area is within the permissible limits of the Sudanese and the WHO standards. The calcium concentration in the study area also found to be within the permissible limits of the Sudanese and the WHO standards. The nitrate concentration in the upper aquifer ranges between 9.68 and 891 mg/1 which is above the permissible limit of the Sudanese and the WHO standards. The water type in the upper aquifer was found to be calcium-nitrate-chloride-bicarbonate. It appears that the source of the calcium is either for the decay of dead animal bones or the dissolution of calcareous deposits within the upper aquifer. It can be concluded that the quality of groundwater in the study area is good for the human consumption. (Author)

  14. Sulfinylated Azadecalins act as functional mimics of a pollen germination stimulant in Arabidopsis pistils

    Science.gov (United States)

    Qin, Yuan; Wysocki, Ronald J; Somogyi, Arpad; Feinstein, Yelena; Franco, Jessica Y; Tsukamoto, Tatsuya; Dunatunga, Damayanthi; Levy, Clara; Smith, Steven; Simpson, Robert; Gang, David; Johnson, Mark A; Palanivelu, Ravishankar

    2011-01-01

    SUMMARY Polarized cell elongation is triggered by small molecule cues during development of diverse organisms. During plant reproduction, pollen interactions with the stigma result in the polar outgrowth of a pollen tube, which delivers sperm cells to the female gametophyte to effect double fertilization. In many plants, pistils stimulate pollen germination. However, in Arabidopsis, the effect of pistils on pollen germination and the pistil factors that stimulate pollen germination remain poorly characterized. Here, we demonstrate that stigma, style, and ovules in Arabidopsis pistils stimulate pollen germination. We isolated an Arabidopsis pistil extract fraction that stimulates Arabidopsis pollen germination, and employed ultrahigh resolution ESI FT-ICR and MS/MS techniques to accurately determine the mass (202.126 daltons) of a compound that is specifically present in this pistil extract fraction. Using the molecular formula (C10H19NOS) and tandem mass spectral fragmentation patterns of the m/z (mass to charge ratio) 202.126 ion, we postulated chemical structures, devised protocols, synthesized N-Methanesulfinyl 1- and 2-azadecalins that are close structural mimics of the m/z 202.126 ion, and showed that they are sufficient to stimulate Arabidopsis pollen germination in vitro (30 µM stimulated ~50% germination) and elicit accession-specific response. Although N-Methanesulfinyl 2-azadecalin stimulated pollen germination in three species of Lineage I of Brassicaceae, it did not induce a germination response in Sisymbrium irio (Lineage II of Brassicaceae) and tobacco, indicating that activity of the compound is not random. Our results show that Arabidopsis pistils promote germination by producing azadecalin-like molecules to ensure rapid fertilization by the appropriate pollen. PMID:21801250

  15. Predictive analysis of the influence of the chemical composition and pre-processing regimen on structural properties of steel alloys using machine learning techniques

    Science.gov (United States)

    Krishnamurthy, Narayanan; Maddali, Siddharth; Romanov, Vyacheslav; Hawk, Jeffrey

    We present some structural properties of multi-component steel alloys as predicted by a random forest machine-learning model. These non-parametric models are trained on high-dimensional data sets defined by features such as chemical composition, pre-processing temperatures and environmental influences, the latter of which are based upon standardized testing procedures for tensile, creep and rupture properties as defined by the American Society of Testing and Materials (ASTM). We quantify the goodness of fit of these models as well as the inferred relative importance of each of these features, all with a conveniently defined metric and scale. The models are tested with synthetic data points, generated subject to the appropriate mathematical constraints for the various features. By this we highlight possible trends in the increase or degradation of the structural properties with perturbations in the features of importance. This work is presented as part of the Data Science Initiative at the National Energy Technology Laboratory, directed specifically towards the computational design of steel alloys.

  16. Exploring a physico-chemical multi-array explanatory model with a new multiple covariance-based technique: structural equation exploratory regression.

    Science.gov (United States)

    Bry, X; Verron, T; Cazes, P

    2009-05-29

    In this work, we consider chemical and physical variable groups describing a common set of observations (cigarettes). One of the groups, minor smoke compounds (minSC), is assumed to depend on the others (minSC predictors). PLS regression (PLSR) of m inSC on the set of all predictors appears not to lead to a satisfactory analytic model, because it does not take into account the expert's knowledge. PLS path modeling (PLSPM) does not use the multidimensional structure of predictor groups. Indeed, the expert needs to separate the influence of several pre-designed predictor groups on minSC, in order to see what dimensions this influence involves. To meet these needs, we consider a multi-group component-regression model, and propose a method to extract from each group several strong uncorrelated components that fit the model. Estimation is based on a global multiple covariance criterion, used in combination with an appropriate nesting approach. Compared to PLSR and PLSPM, the structural equation exploratory regression (SEER) we propose fully uses predictor group complementarity, both conceptually and statistically, to predict the dependent group.

  17. On the sub-band gap optical absorption in heat treated cadmium sulphide thin film deposited on glass by chemical bath deposition technique

    International Nuclear Information System (INIS)

    Chattopadhyay, P.; Karim, B.; Guha Roy, S.

    2013-01-01

    The sub-band gap optical absorption in chemical bath deposited cadmium sulphide thin films annealed at different temperatures has been critically analyzed with special reference to Urbach relation. It has been found that the absorption co-efficient of the material in the sub-band gap region is nearly constant up to a certain critical value of the photon energy. However, as the photon energy exceeds the critical value, the absorption coefficient increases exponentially indicating the dominance of Urbach rule. The absorption coefficients in the constant absorption region and the Urbach region have been found to be sensitive to annealing temperature. A critical examination of the temperature dependence of the absorption coefficient indicates two different kinds of optical transitions to be operative in the sub-band gap region. After a careful analyses of SEM images, energy dispersive x-ray spectra, and the dc current-voltage characteristics, we conclude that the absorption spectra in the sub-band gap domain is possibly associated with optical transition processes involving deep levels and the grain boundary states of the material

  18. On the sub-band gap optical absorption in heat treated cadmium sulphide thin film deposited on glass by chemical bath deposition technique

    Science.gov (United States)

    Chattopadhyay, P.; Karim, B.; Guha Roy, S.

    2013-12-01

    The sub-band gap optical absorption in chemical bath deposited cadmium sulphide thin films annealed at different temperatures has been critically analyzed with special reference to Urbach relation. It has been found that the absorption co-efficient of the material in the sub-band gap region is nearly constant up to a certain critical value of the photon energy. However, as the photon energy exceeds the critical value, the absorption coefficient increases exponentially indicating the dominance of Urbach rule. The absorption coefficients in the constant absorption region and the Urbach region have been found to be sensitive to annealing temperature. A critical examination of the temperature dependence of the absorption coefficient indicates two different kinds of optical transitions to be operative in the sub-band gap region. After a careful analyses of SEM images, energy dispersive x-ray spectra, and the dc current-voltage characteristics, we conclude that the absorption spectra in the sub-band gap domain is possibly associated with optical transition processes involving deep levels and the grain boundary states of the material.

  19. Electro-oxidation of methanol on gold in alkaline media: Adsorption characteristics of reaction intermediates studied using time resolved electro-chemical impedance and surface plasmon resonance techniques

    Science.gov (United States)

    Assiongbon, K. A.; Roy, D.

    2005-12-01

    Electro-catalytic oxidation of methanol is the anode reaction in direct methanol fuel cells. We have studied the adsorption characteristics of the intermediate reactants of this multistep reaction on a gold film electrode in alkaline solutions by combining surface plasmon resonance (SPR) measurements with Fourier transform electro-chemical impedance spectroscopy (FT-EIS). Methanol oxidation in this system shows no significant effects of "site poisoning" by chemisorbed CO. Our results suggest that OH - chemisorbed onto Au acts as a stabilizing agent for the surface species of electro-active methanol. Double layer charging/discharging and adsorption/desorption of OH - show more pronounced effects than adsorption/oxidation of methanol in controlling the surface charge density of the Au substrate. These effects are manifested in both the EIS and the SPR data, and serve as key indicators of the surface reaction kinetics. The data presented here describe the important role of adsorbed OH - in electro-catalysis of methanol on Au, and demonstrate how SPR and FT-EIS can be combined for quantitative probing of catalytically active metal-solution interfaces.

  20. New fabrication technique using side-wall-type plasma-enhanced chemical-vapor deposition for a floating gate memory with a Si nanodot

    Energy Technology Data Exchange (ETDEWEB)

    Ichikawa, Kazunori; Punchaipetch, Prakaipetch; Yano, Hiroshi; Hatayama, Tomoaki; Uraoka, Yukiharu; Fuyuki, Takashi [Nara Institute of Science and Techonology, Ikoma, Nara (Japan); Tomyo, Atsushi; Takahashi, Eiji; Hayashi, Tsukasa; Ogata, Kiyoshi [Nissin Electric Co., Ltd., Kyoto (Japan)

    2006-08-15

    We have used side-wall-type plasma-enhanced chemical-vapor deposition (PECVD)to fabricate a floating gate memory using a Si nano-crystal dot on thermal SiO{sub 2} at a low temperature of 430 .deg. C. Atomic and radical hydrogen plays an important role in the low-temperature formation of the dot. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) analyses revealed that the average dot size and density were approximately 5 nm and 8.5 X 10{sup 11} cm{sup -2}, respectively. The electronic properties were investigated with metal-oxide-semiconductor-field-effect transistors (MOSFETs) by embedding the nanocrystal dots into SiO{sub 2} fabricated using CVD. Electron charging and discharging were clearly confirmed at room temperature by the transient behavior of the capacitance and the transfer curve. The number of electrons confined in a single dot was approximately one. Furthermore, we evaluated the electronic behavior by varying the bias condition or the operating temperature. The critical charge density could be confirmed to be independent of the injection condition.

  1. A Stimulator ASIC Featuring Versatile Management for Vestibular Prostheses.

    Science.gov (United States)

    Dai Jiang; Demosthenous, Andreas; Perkins, Timothy; Xiao Liu; Donaldson, Nick

    2011-04-01

    This paper presents a multichannel stimulator ASIC for an implantable vestibular prosthesis. The system features versatile stimulation management which allows fine setting of the parameters for biphasic stimulation pulses. To address the problem of charge imbalance due to rounding errors, the digital processor can calculate and provide accurate charge correction. A technique to reduce the data rate to the stimulator is described. The stimulator ASIC was implemented in 0.6-μ m high-voltage CMOS technology occupying an area of 2.27 mm(2). The measured performance of the ASIC has been verified using vestibular electrodes in saline.

  2. Greek Salvia sclarea L. Essential Oils: Effect of Hydrodistillation Time, Comparison of the Aroma Chemicals Using Hydrodistillation and HS-SPME Techniques

    Directory of Open Access Journals (Sweden)

    Aikaterini Koutsaviti

    2016-05-01

    Full Text Available Since the essential oil of Salvia sclarea is used as a flavouring agent, the effect of different extraction techniques (hydrodistillation & HS-SPME and duration of hydrodistillation (2, 3 and 4 h with respect to yield, composition and identification rate of extracted essential oils from Greek cultivated S. sclarea aerial blooming parts were investigated. Linalool and linalyl acetate levels seemed to decrease with increasing duration of hydrodistillation, while diterpenes increased dramatically, while the head space analysis showed significantly lower levels of linalool in comparison to its ester. Thus, linalool (5.1-35.8%, linalyl acetate (11.3-37.6% and sclareol (0.0-41.8%, concerning the oils obtained by hydrodistillation, were the most important metabolites. Solid-phase microextraction yielded mainly oxygenated monoterpenes, especially linalyl acetate (59.3%, followed by cis-linalool oxide (8.6% and linalool (7.8%.

  3. Control in the Chemical Industry

    Science.gov (United States)

    Jones, R. G.

    1974-01-01

    Discusses various control techniques used in chemical processes, including measuring devices, controller functions, control valves, and feedforward and feedback actions. Applications of control to a real chemical plant are exemplified. (CC)

  4. Chemical Emergencies

    Science.gov (United States)

    When a hazardous chemical has been released, it may harm people's health. Chemical releases can be unintentional, as in the case of an ... the case of a terrorist attack with a chemical weapon. Some hazardous chemicals have been developed by ...

  5. [Transcranial magnetic stimulation].

    Science.gov (United States)

    Tormos, J M; Catalá, M D; Pascual-Leone, A

    Transcranial magnetic stimulation (TMS) permits stimulation of the cerebral cortex in humans without requiring open access to the brain and is one of the newest tools available in neuroscience. There are two main types of application: single-pulse TMS and repetitive TMS. The magnetic stimulator is composed of a series of capacitors that store the voltage necessary to generate a stimulus of the sufficient intensity of generate an electric field in the stimulation coil. The safety of TMS is supported by the considerable experience derived from studies involving electrical stimulation of the cortex in animals and humans, and also specific studies on the safety of TMS in humans. In this article we review historical and technical aspects of TMS, describe its adverse effects and how to avoid them, summarize the applications of TMS in the investigation of different cerebral functions, and discuss the possibility of using TMS for the treatment of neuropsychiatric disorders.

  6. Continuous and semicontinuous monitoring techniques for particulate matter mass and chemical components: a synthesis of findings from EPA's Particulate Matter Supersites Program and related studies.

    Science.gov (United States)

    Solomon, Paul A; Sioutas, Constantinos

    2008-02-01

    The U.S. Environmental Protection Agency (EPA) established the Particulate Matter (PM) Supersites Program to provide key stakeholders (government and private sector) with significantly improved information needed to develop effective and efficient strategies for reducing PM on urban and regional scales. All Supersites projects developed and evaluated methods and instruments, and significant advances have been made and applied within these programs to yield new insights to our understanding of PM accumulation in air as well as improved source-receptor relationships. The tested methods include a variety of continuous and semicontinuous instruments typically with a time resolution of an hour or less. These methods often overcome many of the limitations associated with measuring atmospheric PM mass concentrations by daily filter-based methods (e.g., potential positive or negative sampling artifacts). Semicontinuous coarse and ultrafine mass measurement methods also were developed and evaluated. Other semicontinuous monitors tested measured the major components of PM such as nitrate, sulfate, ammonium, organic and elemental carbon, trace elements, and water content of the aerosol as well as methods for other physical properties of PM, such as number concentration, size distribution, and particle density. Particle mass spectrometers, although unlikely to be used in national routine monitoring networks in the foreseeable future because of their complex technical requirements and cost, are mentioned here because of the wealth of new information they provide on the size-resolved chemical composition of atmospheric particles on a near continuous basis. Particle mass spectrometers likely represent the greatest advancement in PM measurement technology during the last decade. The improvements in time resolution achieved by the reported semicontinuous methods have proven to be especially useful in characterizing ambient PM, and are becoming essential in allowing scientists to

  7. Depleting high-abundant and enriching low-abundant proteins in human serum: An evaluation of sample preparation methods using magnetic nanoparticle, chemical depletion and immunoaffinity techniques.

    Science.gov (United States)

    de Jesus, Jemmyson Romário; da Silva Fernandes, Rafael; de Souza Pessôa, Gustavo; Raimundo, Ivo Milton; Arruda, Marco Aurélio Zezzi

    2017-08-01

    The efficiency of three different depletion methods to remove the most abundant proteins, enriching those human serum proteins with low abundance is checked to make more efficient the search and discovery of biomarkers. These methods utilize magnetic nanoparticles (MNPs), chemical reagents (sequential application of dithiothreitol and acetonitrile, DTT/ACN), and commercial apparatus based on immunoaffinity (ProteoMiner, PM). The comparison between methods shows significant removal of abundant protein, remaining in the supernatant at concentrations of 4.6±0.2, 3.6±0.1, and 3.3±0.2µgµL -1 (n=3) for MNPs, DTT/ACN and PM respectively, from a total protein content of 54µgµL -1 . Using GeLC-MS/MS analysis, MNPs depletion shows good efficiency in removing high molecular weight proteins (>80kDa). Due to the synergic effect between the reagents DTT and ACN, DTT/ACN-based depletion offers good performance in the depletion of thiol-rich proteins, such as albumin and transferrin (DTT action), as well as of high molecular weight proteins (ACN action). Furthermore, PM equalization confirms its efficiency in concentrating low-abundant proteins, decreasing the dynamic range of protein levels in human serum. Direct comparison between the treatments reveals 72 proteins identified when using MNP depletion (43 of them exclusively by this method), but only 20 proteins using DTT/ACN (seven exclusively by this method). Additionally, after PM treatment 30 proteins were identified, seven exclusively by this method. Thus, MNPs and DTT/ACN depletion can be simple, quick, cheap, and robust alternatives for immunochemistry-based protein depletion, providing a potential strategy in the search for disease biomarkers. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Molecular structure, electronic properties, NLO, NBO analysis and spectroscopic characterization of Gabapentin with experimental (FT-IR and FT-Raman) techniques and quantum chemical calculations

    Science.gov (United States)

    Sinha, Leena; Karabacak, Mehmet; Narayan, V.; Cinar, Mehmet; Prasad, Onkar

    2013-05-01

    Gabapentin (GP), structurally related to the neurotransmitter GABA (gamma-aminobutyric acid), mimics the activity of GABA and is also widely used in neurology for the treatment of peripheral neuropathic pain. It exists in zwitterionic form in solid state. The present communication deals with the quantum chemical calculations of energies, geometrical structure and vibrational wavenumbers of GP using density functional (DFT/B3LYP) method with 6-311++G(d,p) basis set. In view of the fact that amino acids exist as zwitterions as well as in the neutral form depending on the environment (solvent, pH, etc.), molecular properties of both the zwitterionic and neutral form of GP have been analyzed. The fundamental vibrational wavenumbers as well as their intensities were calculated and compared with experimental FT-IR and FT-Raman spectra. The fundamental assignments were done on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanical (SQM) method. The electric dipole moment, polarizability and the first hyperpolarizability values of the GP have been calculated at the same level of theory and basis set. The nonlinear optical (NLO) behavior of zwitterionic and neutral form has been compared. Stability of the molecule arising from hyper-conjugative interactions and charge delocalization has been analyzed using natural bond orbital analysis. Ultraviolet-visible (UV-Vis) spectrum of the title molecule has also been calculated using TD-DFT method. The thermodynamic properties of both the zwitterionic and neutral form of GP at different temperatures have been calculated.

  9. A wireless wearable surface functional electrical stimulator

    Science.gov (United States)

    Wang, Hai-Peng; Guo, Ai-Wen; Zhou, Yu-Xuan; Xia, Yang; Huang, Jia; Xu, Chong-Yao; Huang, Zong-Hao; Lü, Xiao-Ying; Wang, Zhi-Gong

    2017-09-01

    In this paper, a wireless wearable functional electrical stimulator controlled by Android phone with real-time-varying stimulation parameters for multichannel surface functional electrical stimulation application has been developed. It can help post-stroke patients using more conveniently. This study focuses on the prototype design, including the specific wristband concept, circuits and stimulation pulse-generation algorithm. A novel stimulator circuit with a driving stage using a complementary current source technique is proposed to achieve a high-voltage compliance, a large output impedance and an accurate linear voltage-to-current conversion. The size of the prototype has been significantly decreased to 17 × 7.5 × 1 cm3. The performance of the prototype has been tested with a loaded resistor and wrist extension/flexion movement of three hemiplegic patients. According to the experiments, the stimulator can generate four-channel charge-balanced biphasic stimulation with a voltage amplitude up to 60 V, and the pulse frequency and width can be adjusted in real time with a range of 100-600 μs and 20-80 Hz, respectively.

  10. Numerical dosimetry of transcranial magnetic stimulation coils

    Science.gov (United States)

    Crowther, Lawrence; Hadimani, Ravi; Jiles, David

    2014-03-01

    Transcranial magnetic stimulation (TMS) is a non-invasive neuromodulation technique capable of stimulating neurons by means of electromagnetic induction. TMS can be used to map brain function and shows promise for the diagnosis and treatment of neurological and psychiatric disorders. Calculation of fields induced in the brain are necessary to accurately identify stimulated neural tissue during TMS. This allows the development of novel TMS coil designs capable of stimulating deeper brain regions and increasing the localization of stimulation that can be achieved. We have performed numerical calculations of magnetic and electric field with high-resolution anatomically realistic human head models to find these stimulated brain regions for a variety of proposed TMS coil designs. The realistic head models contain heterogeneous tissue structures and electrical conductivities, yielding superior results to those obtained from the simplified homogeneous head models that are commonly employed. The attenuation of electric field as a function of depth in the brain and the localization of stimulating field have been methodically investigated. In addition to providing a quantitative comparison of different TMS coil designs the variation of induced field between subjects has been investigated. We also show the differences in induced fields between adult, adolescent and child head models to preemptively identify potential safety issues in the application of pediatric TMS.

  11. Network of vertically c-oriented prismatic InN nanowalls grown on c-GaN/sapphire template by chemical vapor deposition technique

    Science.gov (United States)

    Barick, B. K.; Saroj, Rajendra Kumar; Prasad, Nivedita; Sutar, D. S.; Dhar, S.

    2018-05-01

    Networks of vertically c-oriented prism shaped InN nanowalls, are grown on c-GaN/sapphire templates using a CVD technique, where pure indium and ammonia are used as metal and nitrogen precursors. A systematic study of the growth, structural and electronic properties of these samples shows a preferential growth of the islands along [ 1 1 2 bar 0 ] and [0 0 0 1] directions leading to the formation of such a network structure, where the vertically [0 0 0 1] oriented tapered walls are laterally align along one of the three [ 1 1 2 bar 0 ] directions. Inclined facets of these walls are identified as semipolar (1 1 2 bar 2) -planes of wurtzite InN. Onset of absorption for these samples is observed to be higher than the band gap of InN suggesting a high background carrier concentration in this material. Study of the valence band edge through XPS indicates the formation of positive depletion regions below the surface of the side facets [(1 1 2 bar 2) -planes] of the walls. This is in contrast with the observation for c-plane InN epilayers, where electron accumulation is often reported below the top surface.

  12. Chemical Equation Balancing.

    Science.gov (United States)

    Blakley, G. R.

    1982-01-01

    Reviews mathematical techniques for solving systems of homogeneous linear equations and demonstrates that the algebraic method of balancing chemical equations is a matter of solving a system of homogeneous linear equations. FORTRAN programs using this matrix method to chemical equation balancing are available from the author. (JN)

  13. Evidence for a central 5-hydroxytryptamine receptor stimulation by lysergic acid diethylamide

    Science.gov (United States)

    Andén, N.-E.; Corrodi, H.; Fuxe, K.; Hökfelt, T.

    1968-01-01

    1. Lysergic acid diethylamide (LSD) and the 5-hydroxytryptamine (5-HT) precursor, 5-hydroxytryptophan produced similar functional effects in rat spinal cord and brain to the 5-hydroxytryptamine precursor 5-hydroxytryptophan, which indicates that LSD stimulates central 5-HT receptors. 2. By means of combined histochemical and biochemical techniques it was found that LSD reduced the turnover rate of brain and spinal cord 5-HT, studied after inhibition of the tryptophan hydroxylase by α-propyldopacetamide. The turnover of brain noradrenaline but not dopamine was somewhat accelerated. 3. The functional and chemical effects by LSD were related to dose and to time. They were not observed after the LSD analogues 2-bromo-LSD and methylsergide. 4. The retardation of the 5-HT turnover by LSD may be due to negative feed-back mechanisms evoked by direct stimulation of the central 5-HT receptors. ImagesFIG. 1FIG. 2 PMID:5302837

  14. Electrical Stimulation Elicit Neural Stem Cells Activation:New Perspectives in CNS Repair

    Directory of Open Access Journals (Sweden)

    Ratrel eHuang

    2015-10-01

    Full Text Available Researchers are enthusiastically concerned about neural stem cell (NSC therapy in a wide array of diseases, including stroke, neurodegenerative disease, spinal cord injury (SCI and depression. Although enormous evidences have demonstrated that neurobehavioral improvement may benefit from NSC-supporting regeneration in animal models, approaches to endogenous and transplanted NSCs are blocked by hurdles of migration, proliferation, maturation and integration of NSCs. Electrical stimulation (ES may be a selective nondrug approach for mobilizing NSCs in the central nervous system (CNS. This technique is suitable for clinic application, because it is well established and its potential complications are manageable. Here, we provide a comprehensive review of the emerging positive role of different electrical cues in regulating NSC biology in vitro and in vivo, as well as biomaterial-based and chemical stimulation of NSCs. In the future, ES combined with stem cell therapy or other cues probably becomes an approach for promoting brain repair.

  15. Music acupuncture stimulation method.

    Science.gov (United States)

    Brătilă, F; Moldovan, C

    2007-01-01

    Harmonic Medicine is the model using the theory that the body rhythms synchronize to an outer rhythm applied for therapeutic purpose, can restores the energy balance in acupuncture channels and organs and the condition of well-being. The purpose of this scientific work was to demonstrate the role played by harmonic sounds in the stimulation of the Lung (LU) Meridian (Shoutaiyin Feijing) and of the Kidney (KI) Meridian (Zushaoyin Shenjing). It was used an original method that included: measurement and electronic sound stimulation of the Meridian Entry Point, measurement of Meridian Exit Point, computer data processing, bio feed-back adjustment of the music stimulation parameters. After data processing, it was found that the sound stimulation of the Lung Meridian Frequency is optimal between 122 Hz and 128 Hz, with an average of 124 Hz (87% of the subjects) and for Kidney Meridian from 118 Hz to 121 Hz, with an average of 120 Hz (67% of the subjects). The acupuncture stimulation was more intense for female subjects (> 7%) than for the male ones. We preliminarily consider that an informational resonance phenomenon can be developed between the acupuncture music stimulation frequency and the cellular dipole frequency, being a really "resonant frequency signature" of an acupoint. The harmonic generation and the electronic excitation or low-excitation status of an acupuncture point may be considered as a resonance mechanism. By this kind of acupunctural stimulation, a symphony may act and play a healer role.

  16. Brain stimulation methods to treat tobacco addiction.

    Science.gov (United States)

    Wing, Victoria C; Barr, Mera S; Wass, Caroline E; Lipsman, Nir; Lozano, Andres M; Daskalakis, Zafiris J; George, Tony P

    2013-05-01

    Tobacco smoking is the leading cause of preventable deaths worldwide, but many smokers are simply unable to quit. Psychosocial and pharmaceutical treatments have shown modest results on smoking cessation rates, but there is an urgent need to develop treatments with greater efficacy. Brain stimulation methods are gaining increasing interest as possible addiction therapeutics. The purpose of this paper is to review the studies that have evaluated brain stimulation techniques on tobacco addiction, and discuss future directions for research in this novel area of addiction interventions. Electronic and manual literature searches identified fifteen studies that administered repetitive transcranial magnetic stimulation (rTMS), cranial electrostimulation (CES), transcranial direct current stimulation (tDCS) or deep brain stimulation (DBS). rTMS was found to be the most well studied method with respect to tobacco addiction. Results indicate that rTMS and tDCS targeted to the dorsolateral prefrontal cortex (DLPFC) were the most efficacious in reducing tobacco cravings, an effect that may be mediated through the brain reward system involved in tobacco addiction. While rTMS was shown to reduce consumption of cigarettes, as yet no brain stimulation technique has been shown to significantly increase abstinence rates. It is possible that the therapeutic effects of rTMS and tDCS may be improved by optimization of stimulation parameters and increasing the duration of treatment. Although further studies are needed to confirm the ability of brain stimulation methods to treat tobacco addiction, this review indicates that rTMS and tDCS both represent potentially novel treatment modalities. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. CHEMICAL ENGINEERING DIVISION SUMMARY REPORT

    Energy Technology Data Exchange (ETDEWEB)

    Lawroski, S.; Vogel, R. C.; Levenson, Milton; Munnecke, V. H.

    1963-07-01

    Work reported includes: Chemical-Metallurgical Processing; Fuel Cycle Applications of Volatility and Fluidization Techniques; Calorimetry; Reactor Safety; Energy Conversion; and Determination of Nuclear Constants.

  18. Laser induced pyrolysis techniques

    International Nuclear Information System (INIS)

    Vanderborgh, N.E.

    1976-01-01

    The application of laser pyrolysis techniques to the problems of chemical analysis is discussed. The processes occurring during laser pyrolysis are first briefly reviewed. The problems encountered in laser pyrolysis gas chromatography are discussed using the analysis of phenanthrene and binary hydrocarbons. The application of this technique to the characterization of naturally occurring carbonaceous material such as oil shales and coal is illustrated

  19. Creation of an Enhanced Geothermal System through Hydraulic and Thermal Stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Rose, Peter Eugene [Energy and Geoscience Institute at the University of Utah

    2013-04-15

    This report describes a 10-year DOE-funded project to design, characterize and create an Engineered Geothermal System (EGS) through a combination of hydraulic, thermal and chemical stimulation techniques. Volume 1 describes a four-year Phase 1 campaign, which focused on the east compartment of the Coso geothermal field. It includes a description of the geomechanical, geophysical, hydraulic, and geochemical studies that were conducted to characterize the reservoir in anticipation of the hydraulic stimulation experiment. Phase 1 ended prematurely when the drill bit intersected a very permeable fault zone during the redrilling of target stimulation well 34-9RD2. A hydraulic stimulation was inadvertently achieved, however, since the flow of drill mud from the well into the formation created an earthquake swarm near the wellbore that was recorded, located, analyzed and interpreted by project seismologists. Upon completion of Phase 1, the project shifted focus to a new target well, which was located within the southwest compartment of the Coso geothermal field. Volume 2 describes the Phase 2 studies on the geomechanical, geophysical, hydraulic, and geochemical aspects of the reservoir in and around target-stimulation well 46A-19RD, which is the deepest and hottest well ever drilled at Coso. Its total measured depth exceeding 12,000 ft. It spite of its great depth, this well is largely impermeable below a depth of about 9,000 ft, thus providing an excellent target for stimulation. In order to prepare 46A-19RD for stimulation, however, it was necessary to pull the slotted liner. This proved to be unachievable under the budget allocated by the Coso Operating Company partners, and this aspect of the project was abandoned, ending the program at Coso. The program then shifted to the EGS project at Desert Peak, which had a goal similar to the one at Coso of creating an EGS on the periphery of an existing geothermal reservoir. Volume 3 describes the activities that the Coso team

  20. Using KrF ELA to Improve Gate-Stacked LaAlO₃/ZrO₂ Indium Gallium Zinc Oxide Thin-Film Transistors with Novel Atmospheric Pressure Plasma-Enhanced Chemical Vapor Deposition Technique.

    Science.gov (United States)

    Wu, Chien-Hung; Chang, Kow-Ming; Chen, Yi-Ming; Huang, Bo-Wen; Zhang, Yu-Xin; Wang, Shui-Jinn

    2018-03-01

    Atmospheric pressure plasma-enhanced chemical vapor deposition (AP-PECVD) technique and KrF excimer laser annealing (ELA) were employed for the fabrication of indium gallium zinc oxide thin-film transistors (IGZO-TFTs). Device with a 150 mJ/cm2 laser annealing densities demonstrated excellent electrical characteristics with improved on/off current ratio of 4.7×107, high channel mobility of 10 cm2/V-s, and low subthreshold swing of 0.15 V/dec. The improvements are attributed to the adjustment of oxygen vacancies in the IGZO channel to an appropriate range of around 28.3% and the reduction of traps at the high-k/IGZO interface.

  1. Clinical Applications of Transcranial Magnetic Stimulation in Pediatric Neurology.

    Science.gov (United States)

    Narayana, Shalini; Papanicolaou, Andrew C; McGregor, Amy; Boop, Frederick A; Wheless, James W

    2015-08-01

    Noninvasive brain stimulation is now an accepted technique that is used as a diagnostic aid and in the treatment of neuropsychiatric disorders in adults, and is being increasingly used in children. In this review, we will discuss the basic principles and safety of one noninvasive brain stimulation method, transcranial magnetic stimulation. Improvements in the spatial accuracy of transcranial magnetic stimulation are described in the context of image-guided transcranial magnetic stimulation. The article describes and provides examples of the current clinical applications of transcranial magnetic stimulation in children as an aid in the diagnosis and treatment of neuropsychiatric disorders and discusses future potential applications. Transcranial magnetic stimulation is a noninvasive tool that is safe for use in children and adolescents for functional mapping and treatment, and for many children it aids in the preoperative evaluation and the risk-benefit decision making. © The Author(s) 2014.

  2. In vitro evaluation of the chemical and morphological changes of the enamel surface using different bleaching techniques; Avaliacao in vitro das alteracoes quimica e morfologica da superficie do esmalte utilizando diferentes tecnicas de clareamento dental

    Energy Technology Data Exchange (ETDEWEB)

    Mattos, Alessandra de Siervi

    2003-07-01

    'In vitro' evaluation through MEV and EDS of the morphological and chemical changes, respectively, of the bovine enamel, submitted to different bleaching techniques. For the MEV evaluation eighteen apical thirds were pigmented and divided into two parts. One half of each sample was the control and the other half was bleached according to the protocol of each test group (n= 6). Group I - home bleaching with a 10% carbamide peroxide; group II bleaching with 35% hydrogen peroxide and LED; group III - bleaching with 35% hydrogen peroxide with diode laser bleaching. The same procedure was done with the eighteen samples which were analyzed through EDS and which had their buccal surface grinded and polished before the bleaching procedure in order to obtain more precise values of the fraction of calcium and phosphorus. The results showed no morphological changes among the analyzed control halves and the bleached halves. There was not a statistical significant difference about Ca and P values, among the control halves and the bleached halves regarding the chemical components (p< 0,05). (author)

  3. In vitro evaluation of the chemical and morphological changes of the enamel surface using different bleaching techniques; Avaliacao in vitro das alteracoes quimica e morfologica da superficie do esmalte utilizando diferentes tecnicas de clareamento dental

    Energy Technology Data Exchange (ETDEWEB)

    Mattos, Alessandra de Siervi

    2003-07-01

    'In vitro' evaluation through MEV and EDS of the morphological and chemical changes, respectively, of the bovine enamel, submitted to different bleaching techniques. For the MEV evaluation eighteen apical thirds were pigmented and divided into two parts. One half of each sample was the control and the other half was bleached according to the protocol of each test group (n= 6). Group I - home bleaching with a 10% carbamide peroxide; group II bleaching with 35% hydrogen peroxide and LED; group III - bleaching with 35% hydrogen peroxide with diode laser bleaching. The same procedure was done with the eighteen samples which were analyzed through EDS and which had their buccal surface grinded and polished before the bleaching procedure in order to obtain more precise values of the fraction of calcium and phosphorus. The results showed no morphological changes among the analyzed control halves and the bleached halves. There was not a statistical significant difference about Ca and P values, among the control halves and the bleached halves regarding the chemical components (p< 0,05). (author)

  4. Electro-chemical grinding

    Science.gov (United States)

    Feagans, P. L.

    1972-01-01

    Electro-chemical grinding technique has rotation speed control, constant feed rates, and contour control. Hypersonic engine parts of nickel alloys can be almost 100% machined, keeping tool pressure at virtual zero. Technique eliminates galling and permits constant surface finish and burr-free interrupted cutting.

  5. Biomass chemicals: improvement in quality and quantity with physiological regulators

    Energy Technology Data Exchange (ETDEWEB)

    Kossuth, S.V.

    1984-01-01

    The search for alternative biomass energy forms has centered on two approaches: (1) production of cellulose fiber in biomass of low net energy value per unit weight, such as wood and bagasse, and (2) hydrocarbons of high net energy value per unit weight for use as chemical feedstocks and substitutes for petroleum. Major plant chemical products include oleoresin from pine (Pinus elliottii Engelm., P. palustris Mill.) rubber from the rubber tree (Hevea brasiliensis Muell.), and guayule shrub (Parthenium argentatum Gray) and sugar from sugarcane (Saccharum species). Ethylene may be a unifying natural bioregulator that can increase deposition of biomass chemicals in all four of these systems. Examples of bioregulators include the use of paraquat, diquat, and 2-chloroethylphosphonic acid (CEPA) for stimulating the synthesis of oleoresin, CEPA for prolonging the flow of rubber and increasing rubber synthesis in the rubber tree, and triethylamines of chlorinated phenoxy compounds for stimulating rubber production in guayule. In sugarcane, gibberellic acid (GA3) increases internodal elongation. Glyphosate, CEPA and other regulators increase the deposition of sucrose, diquat and CEPA inhibit flowering, and paraquat desiccates leaves to facilitate leaf removal or burning just prior to harvest. The cellular compartmentalization for the synthesis of these plant chemicals is unique for each species, and dictates cultural and harvest techniques. The mode of action and pathways for the success of these physiological regulators are discussed. 42 references.

  6. Technological Advances in Deep Brain Stimulation.

    Science.gov (United States)

    Ughratdar, Ismail; Samuel, Michael; Ashkan, Keyoumars

    2015-01-01

    Functional and stereotactic neurosurgery has always been regarded as a subspecialty based on and driven by technological advances. However until recently, the fundamentals of deep brain stimulation (DBS) hardware and software design had largely remained stagnant since its inception almost three decades ago. Recent improved understanding of disease processes in movement disorders as well clinician and patient demands has resulted in new avenues of development for DBS technology. This review describes new advances both related to hardware and software for neuromodulation. New electrode designs with segmented contacts now enable sophisticated shaping and sculpting of the field of stimulation, potentially allowing multi-target stimulation and avoidance of side effects. To avoid lengthy programming sessions utilising multiple lead contacts, new user-friendly software allows for computational modelling and individualised directed programming. Therapy delivery is being improved with the next generation of smaller profile, longer-lasting, re-chargeable implantable pulse generators (IPGs). These include IPGs capable of delivering constant current stimulation or personalised closed-loop adaptive stimulation. Post-implantation Magnetic Resonance Imaging (MRI) has long been an issue which has been partially overcome with 'MRI conditional devices' and has enabled verification of DBS lead location. Surgical technique is considering a shift from frame-based to frameless stereotaxy or greater role for robot assisted implantation. The challenge for these contemporary techniques however, will be in demonstrating equivalent safety and accuracy to conventional methods. We also discuss potential future direction utilising wireless technology allowing for miniaturisation of hardware.

  7. Influence of electrical stimulation on carcass and meat quality of ...

    African Journals Online (AJOL)

    In a previous study regarding the effects of Kosher and conventional slaughter techniques on carcass and meat quality of cattle, it was speculated that electrical stimulation may have affected some of the meat qualities. Therefore, the objective of this study was to investigate the effects of electrical stimulation (ES) and ...

  8. Cooled optically stimulated luminescence in CaF2:Mn

    International Nuclear Information System (INIS)

    Miller, S.D.; Endres, G.W.R.; McDonald, J.C.; Swinth, K.L.

    1988-01-01

    A new optically stimulated luminescence technique has been developed for the readout of CaF 2 :Mn thermoluminescent material. Minimum detectable gamma exposures may potentially be measured at 10 nC.kg -1 using the 254 nm line of a mercury lamp. Additional studies were done on CaF 2 :Mn using 351 nm excimer laser stimulation. (author)

  9. Effects of Electrical and Optogenetic Deep Brain Stimulation on Synchronized Oscillatory Activity in Parkinsonian Basal Ganglia.

    Science.gov (United States)

    Ratnadurai-Giridharan, Shivakeshavan; Cheung, Chung C; Rubchinsky, Leonid L

    2017-11-01

    Conventional deep brain stimulation of basal ganglia uses high-frequency regular electrical pulses to treat Parkinsonian motor symptoms but has a series of limitations. Relatively new and not yet clinically tested, optogenetic stimulation is an effective experimental stimulation technique to affect pathological network dynamics. We compared the effects of electrical and optogenetic stimulation of the basal gangliaon the pathologicalParkinsonian rhythmic neural activity. We studied the network response to electrical stimulation and excitatory and inhibitory optogenetic stimulations. Different stimulations exhibit different interactions with pathological activity in the network. We studied these interactions for different network and stimulation parameter values. Optogenetic stimulation was found to be more efficient than electrical stimulation in suppressing pathological rhythmicity. Our findings indicate that optogenetic control of neural synchrony may be more efficacious than electrical control because of the different ways of how stimulations interact with network dynamics.

  10. A comparative study of the electrodeposition and the aqueous chemical growth techniques for the utilization of ZnO nanorods on p-GaN for white light emitting diodes

    Science.gov (United States)

    Kishwar, S.; ul Hasan, K.; Alvi, N. H.; Klason, P.; Nur, O.; Willander, M.

    2011-01-01

    Vertically well aligned zinc oxide nanorods (ZnO NRs) were grown on p-GaN by electrodeposition (ED) and aqueous chemical growth (ACG) techniques and the structures were employed to fabricate white light emitting diodes (LEDs). Room temperature current voltage ( I-V), photoluminescence (PL), and electroluminescence (EL) measurements were performed to investigate and compare both LEDs. In general, the I-V characteristics and the PL spectra of both LEDs were rather similar. Nevertheless, the EL of the ED samples showed an extra emission peak shoulder at 730 nm. Moreover, at the same injection current, the EL spectrum of the ED light emitting diode showed a small UV shift of 12 nm and its white peak was found to be broader when compared to the ACG grown LED. The broadening of the EL spectrum of the LED grown by ED is due to the introduction of more radiative deep level defects. The presented LEDs have shown excellent color rendering indexes reaching a value as high as 95. These results indicate that the ZnO nanorods grown by both techniques possess very interesting electrical and optical properties but the ED is found to be faster and more suitable for the fabrication of white LEDs.

  11. Rapid chemical separations

    CERN Document Server

    Trautmann, N

    1976-01-01

    A survey is given on the progress of fast chemical separation procedures during the last few years. Fast, discontinuous separation techniques are illustrated by a procedure for niobium. The use of such techniques for the chemical characterization of the heaviest known elements is described. Other rapid separation methods from aqueous solutions are summarized. The application of the high speed liquid chromatography to the separation of chemically similar elements is outlined. The use of the gas jet recoil transport method for nuclear reaction products and its combination with a continuous solvent extraction technique and with a thermochromatographic separation is presented. Different separation methods in the gas phase are briefly discussed and the attachment of a thermochromatographic technique to an on-line mass separator is shown. (45 refs).

  12. Electrical stimulation superimposed onto voluntary muscular contraction.

    Science.gov (United States)

    Paillard, Thierry; Noé, Frédéric; Passelergue, Philippe; Dupui, Philippe

    2005-01-01

    Electrical stimulation (ES) reverses the order of recruitment of motor units (MU) observed with voluntary muscular contraction (VOL) since under ES, large MU are recruited before small MU. The superimposition of ES onto VOL (superimposed technique: application of an electrical stimulus during a voluntary muscle action) can theoretically activate more motor units than VOL performed alone, which can engender an increase of the contraction force. Two superimposed techniques can be used: (i) the twitch interpolation technique (ITT), which consists of interjecting an electrical stimulus onto the muscle nerve; and (ii) the percutaneous superimposed electrical stimulation technique (PST), where the stimulation is applied to the muscle belly. These two superimposed techniques can be used to evaluate the ability to fully activate a muscle. They can thus be employed to distinguish the central or peripheral nature of fatigue after exhausting exercise. In general, whatever the technique employed, the superimposition of ES onto volitional exercise does not recruit more MU than VOL, except with eccentric actions. Nevertheless, the neuromuscular response associated with the use of the superimposed technique (ITT and PST) depends on the parameter of the superimposed current. The sex and the training level of the subjects can also modify the physiological impact of the superimposed technique. Although the motor control differs drastically between training with ES and VOL, the integration of the superimposed technique in training programmes with healthy subjects does not reveal significant benefits compared with programmes performed only with voluntary exercises. Nevertheless, in a therapeutic context, training programmes using ES superimposition compensate volume and muscle strength deficit with more efficiency than programmes using VOL or ES separately.

  13. Neutron dosimetry using optically stimulated luminescence

    International Nuclear Information System (INIS)

    Miller, S.D.; Eschbach, P.A.

    1991-06-01

    The addition of thermoluminescent (TL) materials within hydrogenous matrices to detect neutron-induced proton recoils for radiation dosimetry is a well-known concept. Previous attempts to implement this technique have met with limited success, primarily due to the high temperatures required for TL readout and the low melting temperatures of hydrogen-rich plastics. Research in recent years at Pacific Northwest laboratories (PNL) has produced a new Optically Stimulated Luminescence (OSL) technique known as the Cooled Optically Stimulated Luminescence (COSL) that offers, for the first time, the capability of performing extremely sensitive radiation dosimetry at low temperatures. In addition to its extreme sensitivity, the COSL technique offers multiple readout capability, limited fading in a one-year period, and the capability of analyzing single grains within a hydrogenous matrix. 4 refs., 10 figs

  14. Closing the loop of deep brain stimulation.

    Science.gov (United States)

    Carron, Romain; Chaillet, Antoine; Filipchuk, Anton; Pasillas-Lépine, William; Hammond, Constance

    2013-12-20

    High-frequency deep brain stimulation is used to treat a wide range of brain disorders, like Parkinson's disease. The stimulated networks usually share common electrophysiological signatures, including hyperactivity and/or dysrhythmia. From a clinical perspective, HFS is expected to alleviate clinical signs without generating adverse effects. Here, we consider whether the classical open-loop HFS fulfills these criteria and outline current experimental or theoretical research on the different types of closed-loop DBS that could provide better clinical outcomes. In the first part of the review, the two routes followed by HFS-evoked axonal spikes are explored. In one direction, orthodromic spikes functionally de-afferent the stimulated nucleus from its downstream target networks. In the opposite direction, antidromic spikes prevent this nucleus from being influenced by its afferent networks. As a result, the pathological synchronized activity no longer propagates from the cortical networks to the stimulated nucleus. The overall result can be described as a reversible functional de-afferentation of the stimulated nucleus from its upstream and downstream nuclei. In the second part of the review, the latest advances in closed-loop DBS are considered. Some of the proposed approaches are based on mathematical models, which emphasize different aspects of the parkinsonian basal ganglia: excessive synchronization, abnormal firing-rate rhythms, and a deficient thalamo-cortical relay. The stimulation strategies are classified depending on the control-theory techniques on which they are based: adaptive and on-demand stimulation schemes, delayed and multi-site approaches, stimulations based on proportional and/or derivative control actions, optimal control strategies. Some of these strategies have been validated experimentally, but there is still a large reservoir of theoretical work that may point to ways of improving practical treatment.

  15. Closing the loop of deep brain stimulation

    Directory of Open Access Journals (Sweden)

    Romain eCARRON

    2013-12-01

    Full Text Available High-frequency deep brain stimulation is used to treat a wide range of brain disorders, like Parkinson's disease. The stimulated networks usually share common electrophysiological signatures, including hyperactivity and/or dysrhythmia. From a clinical perspective, HFS is expected to alleviate clinical signs without generating adverse effects. Here, we consider whether the classical open-loop HFS fulfils these criteria and outline current experimental or theoretical research on the different types of closed-loop DBS that could provide better clinical outcomes. In the first part of the review, the two routes followed by HFS-evoked axonal spikes are explored. In one direction, orthodromic spikes functionally de-afferent the stimulated nucleus from its downstream target networks. In the opposite direction, antidromic spikes prevent this nucleus from being influenced by its afferent networks. As a result, the pathological synchronized activity no longer propagates from the cortical networks to the stimulated nucleus. The overall result can be described as a reversible functional de-afferentation of the stimulated nucleus from its upstream and downstream nuclei. In the second part of the review, the latest advances in closed-loop DBS are considered. Some of the proposed approaches are based on mathematical models, which emphasize different aspects of the parkinsonian basal ganglia: excessive synchronization, abnormal firing-rate rhythms, and a deficient thalamo-cortical relay. The stimulation strategies are classified depending on the control-theory techniques on which they are based: adaptive and on-demand stimulation schemes, delayed and multi-site approaches, stimulations based on proportional and/or derivative control actions, optimal control strategies. Some of these strategies have been validated experimentally, but there is still a large reservoir of theoretical work that may point to ways of improving practical treatment.

  16. Closing the loop of deep brain stimulation

    Science.gov (United States)

    Carron, Romain; Chaillet, Antoine; Filipchuk, Anton; Pasillas-Lépine, William; Hammond, Constance

    2013-01-01

    High-frequency deep brain stimulation is used to treat a wide range of brain disorders, like Parkinson's disease. The stimulated networks usually share common electrophysiological signatures, including hyperactivity and/or dysrhythmia. From a clinical perspective, HFS is expected to alleviate clinical signs without generating adverse effects. Here, we consider whether the classical open-loop HFS fulfills these criteria and outline current experimental or theoretical research on the different types of closed-loop DBS that could provide better clinical outcomes. In the first part of the review, the two routes followed by HFS-evoked axonal spikes are explored. In one direction, orthodromic spikes functionally de-afferent the stimulated nucleus from its downstream target networks. In the opposite direction, antidromic spikes prevent this nucleus from being influenced by its afferent networks. As a result, the pathological synchronized activity no longer propagates from the cortical networks to the stimulated nucleus. The overall result can be described as a reversible functional de-afferentation of the stimulated nucleus from its upstream and downstream nuclei. In the second part of the review, the latest advances in closed-loop DBS are considered. Some of the proposed approaches are based on mathematical models, which emphasize different aspects of the parkinsonian basal ganglia: excessive synchronization, abnormal firing-rate rhythms, and a deficient thalamo-cortical relay. The stimulation strategies are classified depending on the control-theory techniques on which they are based: adaptive and on-demand stimulation schemes, delayed and multi-site approaches, stimulations based on proportional and/or derivative control actions, optimal control strategies. Some of these strategies have been validated experimentally, but there is still a large reservoir of theoretical work that may point to ways of improving practical treatment. PMID:24391555

  17. Stimulating thought: a functional MRI study of transcranial direct current stimulation in schizophrenia.

    Science.gov (United States)

    Orlov, Natasza D; O'Daly, Owen; Tracy, Derek K; Daniju, Yusuf; Hodsoll, John; Valdearenas, Lorena; Rothwell, John; Shergill, Sukhi S

    2017-09-01

    Individuals with schizophrenia typically suffer a range of cognitive deficits, including prominent deficits in working memory and executive function. These difficulties are strongly predictive of functional outcomes, but there is a paucity of effective therapeutic interventions targeting these deficits. Transcranial direct current stimulation is a novel neuromodulatory technique with emerging evidence of potential pro-cognitive effects; however, there is limited understanding of its mechanism. This was a double-blind randomized sham controlled pilot study of transcranial direct current stimulation on a working memory (n-back) and executive function (Stroop) task in 28 individuals with schizophrenia using functional magnetic resonance imaging. Study participants received 30 min of real or sham transcranial direct current stimulation applied to the left frontal cortex. The 'real' and 'sham' groups did not differ in online working memory task performance, but the transcranial direct current stimulation group demonstrated significant improvement in performance at 24 h post-transcranial direct current stimulation. Transcranial direct current stimulation was associated with increased activation in the medial frontal cortex beneath the anode; showing a positive correlation with consolidated working memory performance 24 h post-stimulation. There was reduced activation in the left cerebellum in the transcranial direct current stimulation group, with no change in the middle frontal gyrus or parietal cortices. Improved performance on the executive function task was associated with reduced activity in the anterior cingulate cortex. Transcranial direct current stimulation modulated functional activation in local task-related regions, and in more distal nodes in the network. Transcranial direct current stimulation offers a potential novel approach to altering frontal cortical activity and exerting pro-cognitive effects in schizophrenia. © The Author (2017). Published by Oxford

  18. Ion-stimulated Gas Desorption Yields of Electropolished, Chemically Etched, and Coated (Au, Ag, Pd, TiZrV) Stainless Steel Vacuum Chambers and St707 Getter Strips Irradiated with 4.2 MeV/u lead ions

    CERN Document Server

    Mahner, E; Küchler, D; Malabaila, M; Taborelli, M

    2005-01-01

    The ion-induced desorption experiment, installed in the CERN Heavy Ion Accelerator LINAC 3, has been used to measure molecular desorption yields for 4.2 MeV/u lead ions impacting under grazing incidence on different accelerator-type vacuum chambers. Desorption yields for H2, CH4, CO, and CO2, which are of fundamental interest for future accelerator applications, are reported for different stainless steel surface treatments. In order to study the effect of the surface oxide layer on the gas desorption, gold-, silver-, palladium-, and getter-coated 316 LN stainless steel chambers and similarly prepared samples were tested for desorption at LINAC 3 and analysed for chemical composition by X-ray Photoemission Spectroscopy (XPS). The large effective desorption yield of 2 x 104 molecules/Pb53+ ion, previously measured for uncoated, vacuum fired stainless steel, was reduced after noble-metal coating by up to 2 orders of magnitude. In addition, pressure rise measurements, the effectiveness of beam scrubbing with le...

  19. Development of chemical analysis techniques: pt. 3

    International Nuclear Information System (INIS)

    Kim, K.J.; Chi, K.Y.; Choi, G.C.

    1981-01-01

    For the purpose of determining trace rare earths a spectrofluorimetric method has been studied. Except Ce and Tb, the fluorescence intensities are not enough to allow satisfactory analysis. Complexing agents such as tungstate and hexafluoroacetylacetone should be employed to increase fluorescence intensities. As a preliminary experiment for the separation of individual rare earth element and uranium, the distribution coefficient, % S here, are obtained on the Dowex 50 W against HCl concentration by a batch method. These % S data are utilized to obtain elution curves. The % S data showed a minimum at around 4 M HCl. To understand this previously known phenomenon the adsorption of Cl - on Dowex 50 W is examined as a function of HCl concentration and found to be decreasing while % S of rare earths increasing. It is interpreted that Cl - and rare earth ions are moved into the resin phase separately and that the charge and the charge densities of these ions are responsible for the different % S curves. Dehydration appears to play an important role in the upturn of the % S curves at higher HCl concentrations

  20. Chemical analysis: modern instrumentation methods and techniques

    National Research Council Canada - National Science Library

    Rouessac, Francis; Rouessac, Annick

    2007-01-01

    ... regulation 2.3 Sample introduction and the injection chamber 2.4 Thermostatically controlled oven 2.5 Columns 2.6 Stationary phases 2.7 Principal gas chromatographic detectors 2.8 Detectors provi...

  1. Transcranial magnetic stimulation: language function.

    Science.gov (United States)

    Epstein, C M

    1998-07-01

    Studies of language using transcranial magnetic stimulation (TMS) have focused both on identification of language areas and on elucidation of function. TMS may result in either inhibition or facilitation of language processes and may operate directly at a presumptive site of language cortex or indirectly through intracortical networks. TMS has been used to create reversible "temporary lesions," similar to those produced by Wada tests and direct cortical electrical stimulation, in cerebral cortical areas subserving language function. Rapid-rate TMS over the left inferior frontal region blocks speech output in most subjects. However, the results are not those predicted from classic models of language organization. Speech arrest is obtained most easily over facial motor cortex, and true aphasia is rare, whereas right hemisphere or bilateral lateralization is unexpectedly prominent. A clinical role for these techniques is not yet fully established. Interfering with language comprehension and verbal memory is currently more difficult than blocking speech output, but numerous TMS studies have demonstrated facilitation of language-related tasks, including oral word association, story recall, digit span, and picture naming. Conversely, speech output also facilitates motor responses to TMS in the dominant hemisphere. Such new and often-unexpected findings may provide important insights into the organization of language.

  2. A new brain stimulation method: Noninvasive transcranial magneto–acoustical stimulation

    International Nuclear Information System (INIS)

    Yuan Yi; Chen Yu-Dong; Li Xiao-Li

    2016-01-01

    We investigate transcranial magneto–acoustical stimulation (TMAS) for noninvasive brain neuromodulation in vivo. TMAS as a novel technique uses an ultrasound wave to induce an electric current in the brain tissue in the static magnetic field. It has the advantage of high spatial resolution and penetration depth. The mechanism of TMAS onto a neuron is analyzed by combining the TMAS principle and Hodgkin–Huxley neuron model. The anesthetized rats are stimulated by TMAS, resulting in the local field potentials which are recorded and analyzed. The simulation results show that TMAS can induce neuronal action potential. The experimental results indicate that TMAS can not only increase the amplitude of local field potentials but also enhance the effect of focused ultrasound stimulation on the neuromodulation. In summary, TMAS can accomplish brain neuromodulation, suggesting a potentially powerful noninvasive stimulation method to interfere with brain rhythms for diagnostic and therapeutic purposes. (paper)

  3. Modulating the brain at work using noninvasive transcranial stimulation.

    Science.gov (United States)

    McKinley, R Andy; Bridges, Nathaniel; Walters, Craig M; Nelson, Jeremy

    2012-01-02

    This paper proposes a shift in the way researchers currently view and use transcranial brain stimulation technologies. From a neuroscience perspective, the standard application of both transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) has been mainly to explore the function of various brain regions. These tools allow for noninvasive and painless modulation of cortical tissue. In the course of studying the function of an area, many studies often report enhanced performance of a task during or following the stimulation. However, little follow-up research is typically done to further explore these effects. Approaching this growing pool of cognitive neuroscience literature with a neuroergonomics mindset (i.e., studying the brain at work), the possibilities of using these stimulation techniques for more than simply investigating the function of cortical areas become evident. In this paper, we discuss how cognitive neuroscience brain stimulation studies may complement neuroergonomics research on human performance optimization. And, through this discussion, we hope to shift the mindset of viewing transcranial stimulation techniques as solely investigatory basic science tools or possible clinical therapeutic devices to viewing transcranial stimulation techniques as interventional tools to be incorporated in applied science research and systems for the augmentation and enhancement of human operator performance. Published by Elsevier Inc.

  4. Evaluation of laser diode thermal desorption (LDTD) coupled with tandem mass spectrometry (MS/MS) for support of in vitro drug discovery assays: increasing scope, robustness and throughput of the LDTD technique for use with chemically diverse compound libraries.

    Science.gov (United States)

    Beattie, Iain; Smith, Aaron; Weston, Daniel J; White, Peter; Szwandt, Simon; Sealey, Laura

    2012-02-05

    Within the drug discovery environment, the key process in optimising the chemistry of a structural series toward a potential drug candidate is the design, make and test cycle, in which the primary screens consist of a number of in vitro assays, including metabolic stability, cytochrome P450 inhibition, and time-dependent inhibition assays. These assays are often carried out using multiple drug compounds with chemically diverse structural features, often in a 96 well-plate format for maximum time-efficiency, and are supported using rapid liquid chromatographic (LC) sample introduction with a tandem mass spectrometry (MS/MS) selected reaction monitoring (SRM) endpoint, taking around 6.5 h per plate. To provide a faster time-to-decision at this critical point, there exists a requirement for higher sample throughput and a robust, well-characterized analytical alternative. This paper presents a detailed evaluation of laser diode thermal desorption (LDTD), a relatively new ambient sample ionization technique, for compound screening assays. By systematic modification of typical LDTD instrumentation and workflow, and providing deeper understanding around overcoming a number of key issues, this work establishes LDTD as a practical, rapid alternative to conventional LC-MS/MS in drug discovery, without need for extensive sample preparation or expensive, scope-limiting internal standards. Analysis of both the five and three cytochrome P450 competitive inhibition assay samples by LDTD gave improved sample throughput (0.75 h per plate) and provided comparable data quality as the IC₅₀ values obtained were within 3 fold of those calculated from the LC-MS/MS data. Additionally when applied generically to a chemically diverse library of over 250 proprietary compounds from the AstraZeneca design, make and test cycle, LDTD demonstrated a success rate of 98%. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Magnetic fields in noninvasive brain stimulation.

    Science.gov (United States)

    Vidal-Dourado, Marcos; Conforto, Adriana Bastos; Caboclo, Luis Otávio Sales Ferreira; Scaff, Milberto; Guilhoto, Laura Maria de Figueiredo Ferreira; Yacubian, Elza Márcia Targas

    2014-04-01

    The idea that magnetic fields could be used therapeutically arose 2000 years ago. These therapeutic possibilities were expanded after the discovery of electromagnetic induction by the Englishman Michael Faraday and the American Joseph Henry. In 1896, Arsène d'Arsonval reported his experience with noninvasive brain magnetic stimulation to the scientific French community. In the second half of the 20th century, changing magnetic fields emerged as a noninvasive tool to study the nervous system and to modulate neural function. In 1985, Barker, Jalinous, and Freeston presented transcranial magnetic stimulation, a relatively focal and painless technique. Transcranial magnetic stimulation has been proposed as a clinical neurophysiology tool and as a potential adjuvant treatment for psychiatric and neurologic conditions. This article aims to contextualize the progress of use of magnetic fields in the history of neuroscience and medical sciences, until 1985.

  6. Transcranial direct-current stimulation as treatment in epilepsy.

    Science.gov (United States)

    Gschwind, Markus; Seeck, Margitta

    2016-12-01

    Neuromodulation (NM) is a complementary therapy for patients with drug-resistant epilepsy. Vagal nerve stimulation and deep brain stimulation of the anterior thalamus are established techniques and have shown their efficacy in lowering seizure frequency, but they are invasive and rarely render patients seizure-free. Non-invasive NM techniques are therefore increasingly investigated in a clinical context. Areas covered: Current knowledge about transcranial direct-current stimulation (tDCS) and other non-invasive NM in patients with epilepsy, based on the available animal and clinical studies from PubMed search. Expert commentary: tDCS modulates neuronal membrane potentials, and consequently alters cortical excitability. Cathodal stimulation leads to cortical inhibition, which is of particular importance in epilepsy treatment. The antiepileptic efficacy is promising but still lacks systematic studies. The beneficial effect, seen in ~20%, outlasts the duration of stimulation, indicating neuronal plasticity and is therefore of great interest to obtain long-term effects.

  7. IDEA: Stimulating Oral Production.

    Science.gov (United States)

    Easley, Jacob J.

    1995-01-01

    Presents daily activities that facilitate complete sentence response, promote oral production, and aid the learning of vocabulary in foreign-language classes. Because speech is the primary form of communication in the foreign-language classroom, it is important to stimulate students to converse as soon as possible. (Author/CK)

  8. stimulated BV2 Microglial

    African Journals Online (AJOL)

    2012-03-26

    Mar 26, 2012 ... 2), in LPS-stimulated BV2 microglial cells. The level of NO production was analyzed using Griess reaction. The release of PGE2 was determined using sandwich enzyme-linked immunosorbent assay. The DNA-binding activity of nuclear factor-κB (NF-κB) was measured by electrophoretic mobility shift assay ...

  9. Experimental techniques; Techniques experimentales

    Energy Technology Data Exchange (ETDEWEB)

    Roussel-Chomaz, P. [GANIL CNRS/IN2P3, CEA/DSM, 14 - Caen (France)

    2007-07-01

    This lecture presents the experimental techniques, developed in the last 10 or 15 years, in order to perform a new class of experiments with exotic nuclei, where the reactions induced by these nuclei allow to get information on their structure. A brief review of the secondary beams production methods will be given, with some examples of facilities in operation or under project. The important developments performed recently on cryogenic targets will be presented. The different detection systems will be reviewed, both the beam detectors before the targets, and the many kind of detectors necessary to detect all outgoing particles after the reaction: magnetic spectrometer for the heavy fragment, detection systems for the target recoil nucleus, {gamma} detectors. Finally, several typical examples of experiments will be detailed, in order to illustrate the use of each detector either alone, or in coincidence with others. (author)

  10. Computer modeling of Motor Cortex Stimulation: Effects of Anodal, Cathodal and Bipolar Stimulation

    NARCIS (Netherlands)

    Manola, L.; Holsheimer, J.; Buitenweg, Jan R.; Veltink, Petrus H.

    2007-01-01

    Motor cortex stimulation (MCS) is a promising clinical technique for treatment of chronic pain. However, optimization of the therapeutic efficacy is hampered since it is not known how electrically activated neural structures in the motor cortex can induce pain relief. Furthermore, multiple neural

  11. Palatoglossus coupling in selective upper airway stimulation.

    Science.gov (United States)

    Heiser, Clemens; Edenharter, Günther; Bas, Murat; Wirth, Markus; Hofauer, Benedikt

    2017-10-01

    Selective upper airway stimulation (sUAS) of the hypoglossal nerve is a useful therapy to treat patients with obstructive sleep apnea. Is it known that multiple obstructions can be solved by this stimulation technique, even at the retropalatal region. The aim of this study was to verify the palatoglossus coupling at the soft palate during stimulation. Single-center, prospective clinical trail. Twenty patients who received an sUAS implant from April 2015 to April 2016 were included. A drug-induced sedated endoscopy (DISE) was performed before surgery. Six to 12 months after activation of the system, patients' tongue motions were recorded, an awake transnasal endoscopy was performed with stimulation turned on, and a DISE with stimulation off and on was done. Patients with a bilateral protrusion of the tongue base showed a significantly increased opening at the retropalatal level compared to ipsilateral protrusions. Furthermore, patients with a clear activation of the geniohyoid muscle showed a better reduction in apnea-hypopnea index. A bilateral protrusion of the tongue base during sUAS seems to be accompanied with a better opening of the soft palate. This effect can be explained by the palatoglossal coupling, due to its linkage of the muscles within the soft palate to those of the lateral tongue body. 4 Laryngoscope, 127:E378-E383, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  12. Interspecies interactions stimulate diversification of the Streptomyces coelicolor secreted metabolome.

    Science.gov (United States)

    Traxler, Matthew F; Watrous, Jeramie D; Alexandrov, Theodore; Dorrestein, Pieter C; Kolter, Roberto

    2013-08-20

    Soils host diverse microbial communities that include filamentous actinobacteria (actinomycetes). These bacteria have been a rich source of useful metabolites, including antimicrobials, antifungals, anticancer agents, siderophores, and immunosuppressants. While humans have long exploited these compounds for therapeutic purposes, the role these natural products may play in mediating interactions between actinomycetes has been difficult to ascertain. As an initial step toward understanding these chemical interactions at a systems level, we employed the emerging techniques of nanospray desorption electrospray ionization (NanoDESI) and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) imaging mass spectrometry to gain a global chemical view of the model bacterium Streptomyces coelicolor interacting with five other actinomycetes. In each interaction, the majority of secreted compounds associated with S. coelicolor colonies were unique, suggesting an idiosyncratic response from S. coelicolor. Spectral networking revealed a family of unknown compounds produced by S. coelicolor during several interactions. These compounds constitute an extended suite of at least 12 different desferrioxamines with acyl side chains of various lengths; their production was triggered by siderophores made by neighboring strains. Taken together, these results illustrate that chemical interactions between actinomycete bacteria exhibit high complexity and specificity and can drive differential secondary metabolite production. Actinomycetes, filamentous actinobacteria from the soil, are the deepest natural source of useful medicinal compounds, including antibiotics, antifungals, and anticancer agents. There is great interest in developing new strategies that increase the diversity of metabolites secreted by actinomycetes in the laboratory. Here we used several metabolomic approaches to examine the chemicals made by these bacteria when grown in pairwise coculture. We found that

  13. Neutron stimulated emission computed tomography: Background corrections

    International Nuclear Information System (INIS)

    Floyd, Carey E.; Sharma, Amy C.; Bender, Janelle E.; Kapadia, Anuj J.; Xia, Jessie Q.; Harrawood, Brian P.; Tourassi, Georgia D.; Lo, Joseph Y.; Kiser, Matthew R.; Crowell, Alexander S.; Pedroni, Ronald S.; Macri, Robert A.; Tajima, Shigeyuki; Howell, Calvin R.

    2007-01-01

    Neutron stimulated emission computed tomography (NSECT) is an imaging technique that provides an in-vivo tomographic spectroscopic image of the distribution of elements in a body. To achieve this, a neutron beam illuminates the body. Nuclei in the body along the path of the beam are stimulated by inelastic scattering of the neutrons in the beam and emit characteristic gamma photons whose unique energy identifies the element. The emitted gammas are collected in a spectrometer and form a projection intensity for each spectral line at the projection orientation of the neutron beam. Rotating and translating either the body or the beam will allow a tomographic projection set to be acquired. Images are reconstructed to represent the spatial distribution of elements in the body. Critical to this process is the appropriate removal of background gamma events from the spectrum. Here we demonstrate the equivalence of two background correction techniques and discuss the appropriate application of each

  14. Chemical warfare agents

    Directory of Open Access Journals (Sweden)

    Vijayaraghavan R

    2010-01-01

    Full Text Available Among the Weapons of Mass Destruction, chemical warfare (CW is probably one of the most brutal created by mankind in comparison with biological and nuclear warfare. Chemical weapons are inexpensive and are relatively easy to produce, even by small terrorist groups, to create mass casualties with small quantities. The characteristics of various CW agents, general information relevant to current physical as well as medical protection methods, detection equipment available and decontamination techniques are discussed in this review article. A brief note on Chemical Weapons Convention is also provided.

  15. Chemical warfare agents

    Science.gov (United States)

    Ganesan, K.; Raza, S. K.; Vijayaraghavan, R.

    2010-01-01

    Among the Weapons of Mass Destruction, chemical warfare (CW) is probably one of the most brutal created by mankind in comparison with biological and nuclear warfare. Chemical weapons are inexpensive and are relatively easy to produce, even by small terrorist groups, to create mass casualties with small quantities. The characteristics of various CW agents, general information relevant to current physical as well as medical protection methods, detection equipment available and decontamination techniques are discussed in this review article. A brief note on Chemical Weapons Convention is also provided. PMID:21829312

  16. [Transcranial magnetic stimulation and motor cortex stimulation in neuropathic pain].

    Science.gov (United States)

    Mylius, V; Ayache, S S; Teepker, M; Kappus, C; Kolodziej, M; Rosenow, F; Nimsky, C; Oertel, W H; Lefaucheur, J P

    2012-12-01

    Non-invasive and invasive cortical stimulation allows the modulation of therapy-refractory neuropathic pain. High-frequency repetitive transcranial magnetic stimulation (rTMS) of the contralateral motor cortex yields therapeutic effects at short-term and predicts the benefits of epidural motor cortex stimulation (MCS). The present article summarizes the findings on application, mechanisms and therapeutic effects of cortical stimulation in neuropathic pain.

  17. Repetitive transcranial magnetic stimulation to improve mood and motor function in Parkinson's disease.

    NARCIS (Netherlands)

    Helmich, R.C.G.; Siebner, H.R.; Bakker, M.; Munchau, A.; Bloem, B.R.

    2006-01-01

    Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique that can produce lasting changes in excitability and activity in cortical regions underneath the stimulation coil (local effect), but also within functionally connected cortical or subcortical regions

  18. Considering the influence of stimulation parameters on the effect of conventional and high-definition transcranial direct current stimulation.

    Science.gov (United States)

    To, Wing Ting; Hart, John; De Ridder, Dirk; Vanneste, Sven

    2016-01-01

    Recently, techniques to non-invasively modulate specific brain areas gained popularity in the form of transcranial direct current stimulation (tDCS) and high-definition transcranial direct current stimulation. These non-invasive techniques have already shown promising outcomes in various studies with healthy subjects as well as patient populations. Despite widespread dissemination of tDCS, there remain significant unknowns about the influence of a diverse number of tDCS parameters (e.g. polarity, size, position of electrodes & duration of stimulation) in inducing neurophysiological and behavioral effects. This article explores both techniques starting with the history of tDCS, to the differences between conventional tDCS and high-definition transcranial direct current stimulation, the underlying physiological mechanism, the (in)direct effects, the applications of tDCS with varying parameters, the efficacy, the safety issues and the opportunities for future research.

  19. Chemical Peels

    Science.gov (United States)

    ... for Every Season How to Choose the Best Skin Care Products In This Section Dermatologic Surgery What is dermatologic ... for Every Season How to Choose the Best Skin Care Products Chemical Peels Uses for Chemical Peels Learn more ...

  20. Chemical Oscillations

    Indian Academy of Sciences (India)

    IMTECH),. Chandigarh. Praveen Kumar is pursuing his PhD in chemical dynamics at. Panjab University,. Chandigarh. Keywords. Chemical oscillations, autoca-. talYSis, Lotka-Volterra model, bistability, hysteresis, Briggs-. Rauscher reaction.

  1. Stimulated emission depletion following two photon excitation

    OpenAIRE

    Marsh, R. J.; Armoogum, D. A.; Bain, A. J.

    2002-01-01

    The technique of stimulated emission depletion of fluorescence (STED) from a two photon excited molecular population is demonstrated in the S, excited state of fluorescein in ethylene glycol and methanol. Two photon excitation (pump) is achieved using the partial output of a regeneratively amplified Ti:Sapphire laser in conjunction with an optical parametric amplifier whose tuneable output provides a synchronous depletion (dump) pulse. Time resolved fluorescence intensity and anisotropy measu...

  2. Chemical ecotoxicology

    International Nuclear Information System (INIS)

    Paasivirta, J.

    1991-01-01

    This book discusses risk assessment, chemical cycles, structure-activity relations, organohalogens, oil residues, mercury, sampling and analysis of trace chemicals, and emissions from the forestry industry. Topics include: Cycles of chemicals in the environment. Rick assessment and management, strucuture and toxicity, sampling and analysis of trace chemicals in environment, interpretation of the environmental analysis results, mercury in the environment, organohalogen compounds in the environment, emissions from forestry industry, oil residues in the environment: oil spills in the marine environment

  3. Grating stimulated echo

    International Nuclear Information System (INIS)

    Dubetsky, B.; Berman, P.R.; Sleator, T.

    1992-01-01

    A theory of a grating simulated echo (GTE) is developed. The GSE involves the sequential excitation of atoms by two counterpropagating traveling waves, a standing wave, and a third traveling wave. It is shown that the echo signal is very sensitive to small changes in atomic velocity, much more sensitive than the normal stimulated echo. Use of the GSE as a collisional probe or accelerometer is discussed

  4. Thyroid Stimulating Hormone Receptor

    Directory of Open Access Journals (Sweden)

    Murat Tuncel

    2017-02-01

    Full Text Available Thyroid stimulating hormone receptor (TSHR plays a pivotal role in thyroid hormone metabolism. It is a major controller of thyroid cell function and growth. Mutations in TSHR may lead to several thyroid diseases, most commonly hyperthyroidism. Although its genetic and epigenetic alterations do not directly lead to carcinogenesis, it has a crucial role in tumor growth, which is initiated by several oncogenes. This article will provide a brief review of TSHR and related diseases.

  5. Chemical sensor

    Science.gov (United States)

    Rauh, R. David (Inventor)

    1990-01-01

    A sensor for detecting a chemical substance includes an insertion element having a structure which enables insertion of the chemical substance with a resulting change in the bulk electrical characteristics of the insertion element under conditions sufficient to permit effective insertion; the change in the bulk electrical characteristics of the insertion element is detected as an indication of the presence of the chemical substance.

  6. Nuclear techniques for the determination of protein content in plant material

    International Nuclear Information System (INIS)

    Niemann, E.G.

    1980-01-01

    Elemental analysis for nitrogen has gained in importance over the last decade, as protein improvement and protein control in food and feed has come to be recognized as one of the most promising ways of overcoming deficiencies in food production and distribution. The need for fast and reliable screening methods has stimulated the improvement and automation of classic chemical methods for protein and nitrogen determination and, on the other hand, the development and adaptation of physical and nuclear analysis procedures. After about ten years of work this process has come to a stage where a critical evaluation of the existing methods seems necessary and justified. The present review describes and compares nuclear techniques for nitrogen determination in plant material. These include activation analysis techniques, based on various nuclear reactions, initiated by fast and thermal neutrons, energetic photons, protons, deuterons and α-particles. Other nuclear methods have been applied for nitrogen or protein determination, like ESCA, PIXE, NMR, NQR and Moessbauer spectroscopy, some of which possess good potential as screening methods. Depending on the needs, such as sample size, analysis rate and postulated accuracy, different nuclear techniques may be selected today for nitrogen screening. Some of the techniques discussed have additional potential for carbon or oxygen determination, for measuring depth or lateral N distribution, or for the recognition of the type of chemical N binding. Though most if not all techniques need further development for routine application, they are able to compete with chemical techniques in cost, rate and accuracy. (author)

  7. Low intensity transcranial electric stimulation

    DEFF Research Database (Denmark)

    Antal, Andrea; Alekseichuk, I; Bikson, M

    2017-01-01

    Low intensity transcranial electrical stimulation (TES) in humans, encompassing transcranial direct current (tDCS), transcutaneous spinal Direct Current Stimulation (tsDCS), transcranial alternating current (tACS), and transcranial random noise (tRNS) stimulation or their combinations, appears...

  8. Geophysical Monitoring of Coupled Microbial and Geochemical Processes During Stimulated Subsurface Bioremediation

    International Nuclear Information System (INIS)

    Williams, Kenneth H.; Kemna, Andreas; Wilkins, Michael J.; Druhan, Jennifer L.; Arntzen, Evan V.; N'Guessan, A. Lucie; Long, Philip E.; Hubbard, Susan S.; Banfield, Jillian F.

    2009-01-01

    Understanding how microorganisms alter their physical and chemical environment during bioremediation is hindered by our inability to resolve subsurface microbial activity with high spatial resolution. Here we demonstrate the use of a minimally invasive geophysical technique to monitor stimulated microbial activity during acetate amendment in an aquifer near Rifle, Colorado. During electrical induced polarization (IP) measurements, spatiotemporal variations in the phase response between imposed electric current and the resultant electric field correlated with changes in groundwater geochemistry accompanying stimulated iron and sulfate reduction and sulfide mineral precipitation. The magnitude of the phase response varied with measurement frequency (0.125 and 1 Hz) and was dependent upon the dominant metabolic process. The spectral effect was corroborated using a biostimulated column experiment containing Rifle sediments and groundwater. Fluids and sediments recovered from regions exhibiting an anomalous phase response were enriched in Fe(II), dissolved sulfide, and cell-associated FeS nanoparticles. The accumulation of mineral precipitates and electroactive ions altered the ability of pore fluids to conduct electrical charge, accounting for the anomalous IP response and revealing the usefulness of multifrequency IP measurements for monitoring mineralogical and geochemical changes accompanying stimulated subsurface bioremediation

  9. Determination of Methylmercury Traces in Biological Matrix: Chemical Extraction and Nuclear Quantification with the Neutron Activation Analysis Technique; Determinacion de Trazas de Metilmercurio en Matriz Biologica: Extracion Quimica y Cuantificacion Mediante la Tecnica Nuclear de Analisis por Activacion Neutronica (AANI)

    Energy Technology Data Exchange (ETDEWEB)

    Soldati, A L [Instituto Balseiro, Universidad Nacional de Cuyo, Centro Atomico Bariloche (Argentina)

    2002-07-01

    Mercury is present in the environment as a result of the human and natural activities.The total amount of Hg present in the biosphere has been incremented three times since the industrial era, and now it is affecting in a global sense all the ecosystem.One of the main entrance of Hg in the human diet is the consumption of fish and other marine creatures.Most of the ingested Hg is mono methylmercury (MeHg), which is one of the most toxic forms in which this element could be found because it crosses membranes.Since the toxicity levels are low, the determination of concentrations of total Hg and Me Hg require very careful sampling, sample conditioning and analytical procedures to prevent either losses or contamination, or the degradation of the Hg species.In this work, we implemented a chemical Me Hg extraction procedure, using a ionic exchange resin, with three different types of fish tissue: muscle, liver and hepato pancreas.After Me Hg extraction, the determination and quantification was made by Instrumental Neutron Activation Analysis, by measuring the {sup 197} Au, y el {sup 203} Tl deexcitation s, created through the radioactive decay of the isotopes {sup 197} Hg y {sup 203} Hg.The influence of several parameters on the overall extraction process, such as velocity of passage through the ionic exchange column and the acid concentration used in the extraction was evaluated.Regarding the INAA determinations, a choice was made for the irradiation, decay and counting times, neutron and gamma doses, and the counting geometry The detection limit found for this technique (dry weight) is 140 pg MeHg/g. The Hg contents of the muscle samples were measured with the 279 keV emission of the product of the {sup 202} Hg(n,g){sup 203} Hg reaction, with a recovery of (100 {+-} 13)%. Liver and Hepato pancreas samples were measured with the 77 keV gamma emission of the {sup 197} Hg, checking this result with the 67 y 69 keV X emissions from the same isotope.The liver samples needed

  10. Detection of chemicals in the sea - phase 2. Acustic technique for localization of sunken pollutants. Final report; Chemikaliennachweis im Meer - Phase 2. Teilvorhaben: Akustisches Verfahren zur Auffindung gesunkener Schadstoffe. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Mellert, V.; Harms, H.; Matuschek, R.

    2001-08-24

    Detecting thin layers of chemicals covering the sea bottom with existing techniques is not feasible. Scanning an area for possible polluted sea bottom eg. with SONAR-based acoustical measurements requires a pointwise operation. The acoustical measurement technique proposed here scans the sediment surface and allows for the qualitative contamination estimation for distances up to approx. 100 m away from the sensor. Experiments in the laboratory as well as field experiments have been undertaken, where a comparable but riskless contamination method was used. Both scenarios show the same change in the acoustical transmission when thin layers of pollutants cover the sediment. A numerical verification of the observed effects was done. The prototype of the detector system consists of a autonomous acoustical transponder to be deployed separately from the acoustical sensor equipped with an array of hydrophones that can be mounted on a ROV (remotely operated vehicle). Newly developed hydrophones provide an optimalized shielding of ambient noise. The system was designed for a mobile operation on board a ship. A stationary operation eg. in endangered harbor areas or rivers is possible, where a permanent supervision of the sediment layer is required. The necessary modification of the sensor system for this task can be done without additional development. (orig.) [German] Auf dem SONAR-Prinzip beruhende akustische Messverfahren zur Detektion duenner Schadstoffschichten auf dem Meeresboden existieren nicht. Insbesondere die flaechenhafte Sondierung, die Aussagen ueber die Kontamination groesserer Flaechen durch wasserunloesliche Sinker erlaubt, erfordert bei den im Unterwasserbereich bisher bekannten Fernerkundungsverfahren das mehr oder minder punktweise Abscannen der gesamten zu beurteilenden Flaeche. Demgegenueber bietet das hier vorgeschlagene akustische Messverfahren die Moeglichkeit der qualitativen Beurteilung der Kontamination im Abstand bis ca. 100 m vom eigentlichen

  11. Radiation technique for the destruction of plutella

    International Nuclear Information System (INIS)

    1980-01-01

    Plutella can be destroyed by cultivation technique where cabbage is grown interchangebly with other plants, biological technique where the natural enemy of plutella is used, and chemical technique where insecticide is used. Those method do not better results than the sterile male technique which can be either nuclear or chemical in nature. Laboratory, semifield research, and research in a limited field have been carried out when applying the sterile male technique. (SMN)

  12. Mineralogical and physico-chemical study of slags from municipal wastes incineration with a view to a use in road making technique; Etude mineralogique et physico-chimique des machefers d'incineration des ordures menageres (M.I.O.M.) en vue d'une utilisation en technique routiere

    Energy Technology Data Exchange (ETDEWEB)

    Delville, N.

    2003-01-01

    The evolution of waste management regulations now urges to valorize the slags resulting from municipal wastes incineration. However, their long-term environmental and mechanical behaviour is not always well-controlled and some reserve still exist about their use in roadway techniques. A mineralogical and physico-chemical characterization of the slags from Rosiers d'Egletons has been carried out in order to determine the way of formation of their constituents and to understand their nature and evolution. These slags, assimilated to a D{sub 22} soil-type, can be used as backfilling or foundation layer material but their hydric characteristics make their comparison with natural soils delicate. It is a siliceous material (50%) containing calcium (15%), aluminium (10%), iron (7%) and sodium (6%) and characterized by a significant enrichment in lead, copper and zinc (x 100) but showing a satisfactory behaviour with respect to leaching. Its chemical behaviour does not change much with seasons and remains close to other French and European slags coming from grid furnaces. It is made of 35% of relict phases, 40% of primary phases and 25% of secondary phases. The heavy metals are distributed in these three families and with various shapes. An experimental study of the primary phases has permitted to establish a model of crystallisation at the equilibrium to which any slag can be compared in order to know its conditions of making inside the furnace. The high temperature blending present in the Rosiers d'Egletons slags come from the partial fusion of the wastes but are equivalent to experimental blending and seems to crystallize in reductive conditions. An experimental roadway has been made with the Rosiers d'Egletons slag as foundation bed and followed up during two years in order to study the mineralogical, chemical and geo-technical evolution of the material. No deformation of the roadway has been noticed and a hardening seems to develop with time. No noxious

  13. Chemical analysis report 2014

    International Nuclear Information System (INIS)

    Elbouzidi, Saliha; Elyahyaoui, Adil; Ghassan, Acil; Marah, Hamid

    2014-01-01

    This report highlights the results of chemical analyzes related to Major elements, traces and heavy metals carried out at the CNESTEN DASTE in Rabat (Morocco), on behalf of Senegal. These analyzes cover 120 samples. The report presents the analytical techniques used (parameters and methods), a legend and the results tables.

  14. Chemical analysis report 2015

    International Nuclear Information System (INIS)

    2015-01-01

    This report highlights the results of chemical analyzes of fluorides, bromides, lithium and boron carried out at the CNESTEN DASTE in Rabat (Morocco), on behalf of Senegal. These analyzes cover 120 samples. The report presents the analytical techniques used (parameters and methods), a legend and the results tables.

  15. Spinal Cord Stimulation

    DEFF Research Database (Denmark)

    Meier, Kaare

    2014-01-01

    Spinal cord stimulation (SCS) is a surgical treatment for chronic neuropathic pain that is refractory to other treatment. Originally described by Shealy et al. in 1967(1), it is used to treat a range of conditions such as complex regional pain syndrome (CRPS I)(2), angina pectoris(3), radicular...... pain after failed back surgery syndrome (FBSS)(4), pain due to peripheral nerve injury, stump pain(5), peripheral vascular disease(6) and diabetic neuropathy(7,8); whereas phantom pain(9), postherpetic neuralgia(10), chronic visceral pain(11), and pain after partial spinal cord injury(12) remain more...

  16. [Chemical weapons and ch