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Sample records for bulk in-situ gamma-spectrometry

  1. Source term estimation based on in-situ gamma spectrometry using a high purity germanium detector

    Energy Technology Data Exchange (ETDEWEB)

    Pauly, J.; Rojas-Palma, C.; Sohier, A.

    1997-06-01

    An alternative method to reconstruct the source term of a nuclear accident is proposed. The technique discussed here involves the use of in-situ gamma spectrometry. The validation of the applied methodology has been possible through the monitoring of routine releases of Ar-41 originating at a Belgian site from an air cooled graphite research reactor. This technique provides a quick nuclide specific decomposition of the source term and therefore will be have an enormous potential if implemented in nuclear emergency preparedness and radiological assessments of nuclear accidents during the early phase.

  2. In-situ ground gamma spectrometry — an effective tool for geological mapping (the Male Karpaty Mts., Slovakia

    Directory of Open Access Journals (Sweden)

    Mojzeš Andrej

    2016-06-01

    Full Text Available This contribution presents the results of profile in-situ gamma spectrometry measurements that sought to determine the content of natural radionuclides 40K, 238U and 232Th in a near surface horizon of rocks, their weathering cover and soils in the area of the Malé Karpaty Mts. It is widely established that the exploration of radioactivity of bedrocks and cover rocks can be a very effective and useful tool for both geological mapping, for identifying deposits of mineral resources, and even addressing the issues of structural and tectonic geology. This assertion is equally confirmed by the ground gamma spectrometry measurements carried out as part of this case study on larger scales, seeking more detailed geological structure solutions. The results obtained provide a welcome addition to an already existing database, which monitors the content of naturally occurring radionuclides individually for every rock lithotype of the Western Carpathians, by elaborating on the data collected by previous research and by updating this database for any future needs. The presented results confirmed the low to medium radioactivity levels of rocks and soils in the studied area. The highest values were detected in granitoids and metamorfic phyllitic rocks of the Malé Karpaty Mts. core; the lowest values were detected in carbonates, arenaceous sediments and, above all, amphibolite bodies. In this way, the presented results of the interpreted profile (P5 confirm the model of local geological structure as represented on the most up-to-date edition of the geological map of the Male Karpaty Mts. (Polak et al. 2011.

  3. Air Kerma Rate estimation by means of in-situ gamma spectrometry: a Bayesian approach.

    Science.gov (United States)

    Cabal, Gonzalo; Kluson, Jaroslav

    2010-01-01

    Bayesian inference is used to determine the Air Kerma Rate based on in-situ gamma spectrum measurement performed with an NaI(Tl) scintillation detector. The procedure accounts for uncertainties in the measurement and in the mass energy transfer coefficients needed for the calculation. The WinBUGS program (Spiegelhalter et al., 1999) was used. The results show that the relative uncertainties in the Air Kerma estimate are of about 1%, and that the choice of unfolding procedure may lead to an estimate systematic error of 3%.

  4. Air Kerma Rate estimation by means of in-situ gamma spectrometry: A Bayesian approach

    Energy Technology Data Exchange (ETDEWEB)

    Cabal, Gonzalo [Department of Dosimetry and Applications of Ionizing Radiation, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Brehova 7, 115 19 Prague 1 (Czech Republic); Department of Radiation Dosimetry, Nuclear Physics Institute, Academy of Sciences of the Czech Republic, Na Truhlarce 39/64, 180 86 Prague 8 (Czech Republic)], E-mail: cabal@ujf.cas.cz; Kluson, Jaroslav [Department of Dosimetry and Applications of Ionizing Radiation, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Brehova 7, 115 19 Prague 1 (Czech Republic)

    2010-04-15

    Bayesian inference is used to determine the Air Kerma Rate based on in-situ gamma spectrum measurement performed with an NaI(Tl) scintillation detector. The procedure accounts for uncertainties in the measurement and in the mass energy transfer coefficients needed for the calculation. The WinBUGS program () was used. The results show that the relative uncertainties in the Air Kerma estimate are of about 1%, and that the choice of unfolding procedure may lead to an estimate systematic error of 3%.

  5. In-situ gamma spectrometry measurements of time-dependent Xenon-135 inventory in the TRIGA Mark II reactor Vienna

    CERN Document Server

    Riede, Julia

    2013-01-01

    In this work, it has been shown that the time dependent Xe-135 inventory in the TRIGA Mark II reactor in Vienna, Austria can be measured via gamma spectrometry even in the presence of strong background radiation. It is focussing on the measurement of (but not limited to) the nuclide Xe-135. The time dependent Xe-135 inventory of the TRIGA Mark II reactor Vienna has been measured using a temporary beam line between one fuel element of the core placed onto the thermal column after shutdown and a detector system located just above the water surface of the reactor tank. For the duration of one week, multiple gamma ray spectra were recorded automatically, starting each afternoon after reactor shutdown until the next morning. One measurement series has been recorded over the weekend. The Xe-135 peaks were extracted from a total of 1227 recorded spectra using an automated peak search algorithm and analyzed for their time-dependent properties. Although the background gamma radiation present in the core after shutdown...

  6. Determination of Th and U by neutron activation for gamma spectrometry calibration in situ; Determinacion de Th y U por activacion neutronica para calibracion de espectrometria gamma in situ

    Energy Technology Data Exchange (ETDEWEB)

    Nava M, F.; Rios M, C.; Mireles G, F.; Saucedo A, S.; Davila R, I.; Pinedo, J. L. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98060 Zacatecas (Mexico); Landsberger, S., E-mail: iqnava@hotmail.com [University of Texas at Austin, Nuclear Engineering Teaching Laboratory, Pickle Research Campus, R9000 Austin, Texas 78712 (United States)

    2012-10-15

    Using the analysis by neutron activation to determine the profile of the thorium and uranium concentration calibration factors were obtained for their use in the gamma spectrometry in situ. Three sites were selected (San Ramon, Villa de Cos y la Zacatecana) and the analysis by activation was development in the Laboratory of Nuclear Engineering Teaching of the Texas University in Austin with the nuclear reactor Ut-TRIGA. Starting from the gamma spectra in situ, the areas of normalized photo-pick of the radioisotopes were: {sup 208}Tl and {sup 228}Ac for the thorium series and {sup 214}Pb and {sup 214}Bi for the uranium series. The averages of the factors found in units of (cpm/Bq/Kg) are of 105.63{+-}8.32 and 75.87{+-}4.61 for the thorium and uranium, respectively. (Author)

  7. In Situ Formation of Carbon Nanomaterials on Bulk Metallic Materials

    Directory of Open Access Journals (Sweden)

    J. Y. Xu

    2014-01-01

    Full Text Available Carbon nanomaterials were synthesized in situ on bulk 316L stainless steel, pure cobalt, and pure nickel by hybrid surface mechanical attrition treatment (SMAT. The microstructures of the treated samples and the resulted carbon nanomaterials were investigated by SEM and TEM characterizations. Different substrates resulted in different morphologies of products. The diameter of carbon nanomaterials is related to the size of the nanograins on the surface layer of substrates. The possible growth mechanism was discussed. Effects of the main parameters of the synthesis, including the carbon source and gas reactant composition, hydrogen, and the reaction temperature, were studied. Using hybrid SMAT is proved to be an effective way to synthesize carbon nanomaterials in situ on surfaces of metallic materials.

  8. Urban gamma spectrometry. Report 2

    Energy Technology Data Exchange (ETDEWEB)

    Aage, H.K. (Technical Univ. of Denmark, Kgs. Lyngby (Denmark)); Kuukankorpi, S.; Moring, M.; Smolander, P.; Toivonen, H. (Radiation and Nuclear Safety Authority, Helsinki (Finland))

    2009-06-15

    Urban gamma spectrometry has been given only minor attention with the focus being on rural gamma spectrometry. However, in recent years the Nordic emergency management authorities have turned focus towards border control and lost or stolen sources. Gamma spectra measured in urban areas are characterized by a wide variety of spectrum shapes and very fast changes in environmental background. In 2004 a Danish CGS (Carborne Gamma Spectrometry) survey took place in Copenhagen. It was found that gamma spectrometry in urban areas is far more complicated to interpret than had previously been thought and a new method 'Fitting with Spectral Components', FSC, based on NASVD, was tested with some success. In Finland, a database 'LINSSI' has been developed for spectral data management. In CGS search mode a 'peak hypothesis test' is applied to the measured spectra. This system was tested during the Helsinki 2005 Athletics World Championship and it provides fast and reliable automated alarms for intermediate and high level signals. In Sweden mobile detector systems are used for border controls and problems are encountered when making measurement in harbour, container areas. The methods for handling data and for interpretation of urban gamma spectrometry measurements were compared and tested on the same data sets from Copenhagen and Helsinki. Software tools were developed for converting data between the Finnish LINSSI database and the binary file formats used in Denmark and Sweden. The Processing methods used at DTU and STUK have different goals. The ASSS and FSC methods are designed to optimize the overall detection capability of the system, while sacrificing speed, usability and to a certain level robustness. These methods cannot always be used for real time analysis. The Peak Significance method is designed to give robust alarms in real time, while sacrificing some of the detection capability. Thus these methods are not interchangeable, but rather

  9. Bulk Copper Electrodeposition on Gold Imaged by In Situ STM

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Bech-Nielsen, Gregers; Møller, Per

    1996-01-01

    Electrochemical measurements were carried out simultaneously with acquisition of in situ STM images of copper electrodeposition at low cathodic overpotentials and subsequent dissolution from the underlying polycrystalline gold surfaces. The morphologies of the copper deposits were examined....... After the first cycle of copper deposition and dissolution the morphology of the polycrystalline gold surface had apparently changed into a recrystallized phase of a copper-gold alloy. At a given stage of the cycle the potential of the electrode was found to depend linearly on the tip potential....... In a wide range of tip potentials the onset of copper deposition and end of dissolution showed a potential separation of 59 4- 5 mV indicating a single electron process....

  10. Urban gamma spectrometry. Report 1

    Energy Technology Data Exchange (ETDEWEB)

    Aage, H.K. (Technical Univ. of Denmark, Kgs. Lyngby (Denmark)); Kuukankorpi, S.; Moring, M.; Smolander, P.; Toivonen, H. (Radiation and Nuclear Safety Authority, Helsinki (Finland))

    2009-06-15

    This report contains the present status and results for the NKS UGS-project per 1 June 2006 for NKS partners DTU, Denmark, and STUK, Finland. The Danish and Finnish CGS (Carborne Gamma Spectrometry) systems are not of similar types. The Danish CGS system(s) only make use of one NaI(Tl) detector whereas the Finnish CGS system consists of several detectors, NaI(Tl) and HPGe both and as an additional feature the Finnish detectors have position dependent different fields of view. Furthermore, the Finnish system is equipped with an air sampling system. In terms of operation, the Danish detector is located on the rooftop where as the Finnish detectors are located inside the vehicle. The Finnish and the Danish team use different methods for data processing. STUK uses a hypothesis test method to get robust real time alarms (within 10 seconds) when significant peaks from a previously defined set of nuclides are detected. An alarm for a significantly elevated total pulse rate is sent if none of the predefined nuclides is identified. All data are stored to the LINSSI database, which facilitates easy data retrieval for post processing. DEMA/DTU bases their calculations on full spectrum fitting using NASVD and the Danish software NucSpec. Source signals are found from spectrum fitting residuals or from stripping of energy windows - either by the standard 4-windows method or by a measurement based method where stripping factors for any window of interest can be derived from the measurements themselves. A thorough description of the two systems and data processing methods (including mathematics) are described in this report. For the Danish methods of data processing some comparisons have been made, but no final conclusion has been reached yet. Raw urban data has been investigated along with urban data sets to which source signals have been added and searched for. For the Finnish method calibration plots of the minimum detection limits for two different detector types have been

  11. In-Situ Observation of SiC Bulk Single Crystal Growth by XRD System

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In-situ analysis for SiC bulk single crystal growth was reported using vertical X-ray diffractometer system. A furnace for SiC sublimation growth combined with the XRD system which possessed three kinds of functions including topography, rocking curve measurement and crystal growth rate monitoring was developed. These functions could contribute as a powerful tool finding the optimum growth condition by dynamic observation in the crucible. In this study, the in-situ X-ray topographs succeeded to capture dynamic elongation of defects and dislocation generated in the SiC growing crystals. The in-situ rocking curve measurement reviled appearance of mosaic structure in the SiC crystal grown with high growth rate. The in-situ growth rate monitoring also succeeded very precisely using the direct X-ray beam absorption. On the base of findings and facts obtained by the in-situ observations, the importance for the SiC growth was discussed.

  12. The in situ physiology of "Nostocoida limicola" II, a filamentous bacterial morphotype in bulking activated sludge, using fluorescence in situ hybridization and microautoradiography.

    Science.gov (United States)

    Seviour, E M; Eales, K; Izzard, L; Beer, M; Carr, E L; Seviour, R J

    2006-01-01

    The in situ physiology of the actinobacterial bulking and foaming filamentous bacterium "Nostocoida limicola" II was studied by fluorescence in situ hybridization/microautoradiography. Substrate assimilation patterns of pure cultures of this bacterium were different to those seen in activated sludge biomass samples. There was no evidence to suggest that "N. limicola" II preferred hydrophobic substrates, but evidence was produced to support the view that it is metabolically active under anaerobic conditions in activated sludge.

  13. In situ neutron scattering study of nanostructured PbTe-PbS bulk thermoelectric material

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Fei [Temple University; Schmidt, Robert D [ORNL; Case, Eldon D [Michigan State University, East Lansing; An, Ke [ORNL

    2016-01-01

    Nanostructures play an important role in thermoelectric materials. Their thermal stability, such as phase change and evolution at elevated temperatures, is thus of great interest to the thermoelectric community. In this study, in situ neutron diffraction was used to examine the phase evolution of nanostructured bulk PbTe-PbS materials fabricated using hot pressing and pulsed electrical current sintering (PECS). The PbS second phase was observed in all samples in the as-pressed condition. The temperature dependent lattice parameter and phase composition data show an initial formation of PbS precipitates followed by a redissolution during heating. The redissolution process started around 570 600 K, and completed at approximately 780 K. During cooling, the PECS sample followed a reversible curve while the heating/cooling behavior of the hot pressed sample was irreversible.

  14. Novel in situ device for investigating the tensile and fatigue behaviors of bulk materials

    Science.gov (United States)

    Ma, Zhichao; Zhao, Hongwei; Li, Qinchao; Wang, Kaiting; Zhou, Xiaoqin; Hu, Xiaoli; Cheng, Hongbing; Lu, Shuai

    2013-04-01

    For investigating the static tensile and dynamic fatigue behaviors of bulk materials, a miniaturized device with separate modular tensile and fatigue actuators was developed. The fatigue actuator presented good compatibility with the tensile actuator and mainly consisted of a special flexure hinge and piezoelectric stack. In situ fatigue tests under scanning electron microscope or metallographic microscope could be carried out due to the miniaturized dimensions of the device. A displacement correction method of tensile actuator based on load sensor compliance was investigated, and the feasibility of the method was verified by the comparison tests with a commercial tensile instrument. The application of testing the storage and loss modulus as a function of frequency was explained, and the temperature rises of both the piezoelectric stack and specimen were obtained as a function of frequency. Output characteristics of the fatigue actuator were also investigated. Additionally, the discharge performance of piezoelectric stack based on various initial voltages and fatigue tests on C11000 copper was carried out. This paper shows a modularized example that combines a servo motor with a piezoelectric actuator attached to the specimen grip to realize the in situ fatigue tests.

  15. In-situ measurement of annealing kinetics of individual bulk grains in nanostructured aluminium

    DEFF Research Database (Denmark)

    Wu, G.L.; Juul Jensen, Dorte

    2012-01-01

    Non-destructive three-dimensional X-ray diffraction (3DXRD) was used to characterise the coarsening and growth of bulk crystallites in very heavily deformed aluminium in-situ during isothermal annealing. It was found that initially during the annealing, coarsening by recovery dominates. Later...... response of nanometals and thus also for instructing thermal treatment for optimal mechanical properties....

  16. Characterization of silver/polystyrene nanocomposites prepared by in situ bulk radical polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Vukoje, Ivana D., E-mail: ivanav@vinca.rs [Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Vodnik, Vesna V., E-mail: vodves@vinca.rs [Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Džunuzović, Jasna V., E-mail: jasnav2002@googlemail.com [Institute of Chemistry, Technology and Metallurgy (ICTM)-Center of Chemistry, University of Belgrade, Studentski trg 12-16, 11000 Belgrade (Serbia); Džunuzović, Enis S., E-mail: edzunuzovic@tmf.bg.ac.rs [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11120 Belgrade (Serbia); Marinović-Cincović, Milena T., E-mail: milena@vinca.rs [Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Jeremić, Katarina, E-mail: kjeremic@tmf.bg.ac.rs [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11120 Belgrade (Serbia); Nedeljković, Jovan M., E-mail: jovned@vinca.rs [Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia)

    2014-01-01

    Graphical abstract: - Highlights: • Synthesis and characterization of polystyrene nanocomposites based on Ag nanoparticles. • The glass transition temperature decreased in nanocomposites with respect to the pure polymer. • Resistance of the polymer to thermal degradation enhanced with Ag nanoparticles content. - Abstract: Nanocomposites (NCs) with different content of silver nanoparticles (Ag NPs) embeded in polystyrene (PS) matrix were prepared by in situ bulk radical polymerization. The nearly monodisperse Ag NPs protected with oleylamine were synthesized via organic solvo-thermal method and further used as a filler. The as-prepared spherical Ag NPs with diameter of 7.0 ± 1.5 nm were well dispersed in the PS matrix. The structural properties of the resulting Ag/PS NCs were characterized by transmission electron microscope (TEM) and Fourier transform infrared (FTIR) spectroscopy, while optical properties were characterized using optical absorption measurements. The gel permeation chromatography (GPC) measurements showed that the presence of Ag NPs stabilized with oleylamine has no influence on the molecular weight and polydispersity of the PS matrix. The influence of silver content on the thermal properties of Ag/PS NCs was investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results indicated that resistance of PS to thermal degradation was improved upon incorporation of Ag NPs. The Ag/PS NCs have lower glass transition temperatures than neat PS because loosely packed oleylamine molecules at the interface caused the increase of free volume and chain segments mobility near the surface of Ag NPs.

  17. Wear behaviour of Zr-based in situ bulk metallic glass matrix composites

    Indian Academy of Sciences (India)

    X F WU; G A ZHANG; F F WU

    2016-06-01

    Zr-based bulk metallic glass (BMG) and its in situ BMG matrix composites with diameter of 3 mm were fabricated by conventional Cu-mould casting method and the dry sliding wear behaviour of the BMG and composites was investigated. Compared to the pure BMG, the composites exhibited a markedly improved wear resistance from 10 to 48% due to the existence of various volume fractions of the ductile $\\beta$-Zr dendritic phase embedded in the glassy matrix. The composites showed lower friction coefficient and wear rate than the pure BMG. Meanwhile, the surface wearing of the composite with a proper amount of $\\beta$-Zr dendrites was less severe compared to that of the pure BMG. The worn surface of the composite was covered with mild grooves and some fine wear debris, which exhibited the characteristic of a mild abrasive wear. The improvement of the wear resistance of the composite with the proper amount of $\\beta$-Zr crystalline phase is attributed to the fact that the $\\beta$-Zr crystalline phase distributed in the amorphous matrix has some effective load bearing, plastic deformation and work hardening ability to decrease strain accumulation and the release of strain energy in the glassy matrix, restrict the expanding of shear bands and cracks, and occur plastic deformation homogeneously.

  18. High-field flux mapping of (RE)BCO bulk superconductors-Development of an in situ scanning system

    Energy Technology Data Exchange (ETDEWEB)

    Withnell, T.D. [Superconductivity Group, Cambridge University Engineering Department, Trumpington Street, Cambridge CB2 1PZ (United Kingdom)], E-mail: tdw25@cantab.net; Hari-Babu, N.; Ganney, I.; Dennis, A.; Cardwell, D.A. [Superconductivity Group, Cambridge University Engineering Department, Trumpington Street, Cambridge CB2 1PZ (United Kingdom)

    2008-06-15

    Flux mapping of Y-Ba-Cu-O (YBCO) melt-processed, bulk high-temperature superconductors (HTS) is used to visualise the profile of trapped magnetic field on a magnetised sample and to measure the extent of current flow, and hence field penetration, within the bulk microstructure. Grain structure and defects below the sample surface are observed non-destructively by this technique. This paper outlines the design, development and construction of a novel, in situ Hall scanning system using an 8 T magnet and variable temperature insert (VTI). This system is then used to characterise the field trapping properties of bulk samples for different applied field history.

  19. Use of Gamma Spectrometry Method for Environmental Monitoring in the area of NPP

    Energy Technology Data Exchange (ETDEWEB)

    Thinova, L; Cechak, T; Kluson, J; Trojek, T [CTU in Prague, Faculty of Nuclear Sciences and Physical Engineering, Brehova 7, 115 19 Prague 1 (Czech Republic)

    2006-05-15

    It is generally not possible to correctly determine the long and short term impact of human activity upon the environment, without thorough processing of data, obtained through monitoring. It was confirmed that such impact on the environment must be monitored over a long time period. The data obtained must be of high quality, an attribute assured by present state of scientific knowledge. One of the well established methods for monitoring atmospheric deposition of radionuclides in the environment is laboratory and in situ gamma spectrometry. With the aim to monitor an occurrence of a one-time escape or persistent release of fission products into the air, resulting from an operation of a nuclear plant, two types of monitoring are performed: i/ measurement of samples from the environment (Schreber moss, forest humus, pine bark, mushrooms and forest berries) using laboratory gamma spectrometry method in the range up to 3 MeV (those data are used for the trend analysis and for the construction of the contaminationmaps); ii/ in situ gama spectrometry for assessment dosimetry and spectrometry characteristic of photon-fields (those data are used for the dose rate calculation)

  20. Use of Gamma Spectrometry Method for Environmental Monitoring in the area of NPP

    Science.gov (United States)

    Thinova, L.; Cechak, T.; Kluson, J.; Trojek, T.

    2006-05-01

    It is generally not possible to correctly determine the long and short term impact of human activity upon the environment, without thorough processing of data, obtained through monitoring. It was confirmed that such impact on the environment must be monitored over a long time period. The data obtained must be of high quality, an attribute assured by present state of scientific knowledge. One of the well established methods for monitoring atmospheric deposition of radionuclides in the environment is laboratory and in situ gamma spectrometry. With the aim to monitor an occurrence of a one-time escape or persistent release of fission products into the air, resulting from an operation of a nuclear plant, two types of monitoring are performed: i/ measurement of samples from the environment (Schreber moss, forest humus, pine bark, mushrooms and forest berries) using laboratory gamma spectrometry method in the range up to 3 MeV (those data are used for the trend analysis and for the construction of the contaminationmaps); ii/ in situ gama spectrometry for assessment dosimetry and spectrometry characteristic of photon-fields (those data are used for the dose rate calculation).

  1. Gamma spectrometry for chronology of recent sediments

    Energy Technology Data Exchange (ETDEWEB)

    Pittauerova, Daniela

    2013-12-17

    This thesis deals with several aspects of gamma spectrometric analysis of natural and artificial isotopes in sediments and their use as tracers for qualification and quantification of accumulation and mixing processes in different aquatic environments. Sediment cores from three distinct areas including terrigenous sediments deposited on the continental slope off NW Africa, deep sea sediments off Sumba Island and five stations from the Gulf of Eilat in the Red Sea area were measured and interpreted within this dissertation. The main concern in gamma spectrometry of voluminous environmental samples is a reliable efficiency calibration. This is specially relevant for the analysis of low energy gamma emitters (<100 keV). {sup 210}Pb, an important isotopic tracer to cover the period of the last century, is one of them. Within this work mathematical efficiency calibration was applied using a commercial software package. A series of validation tests was performed and evaluated for point and voluminous samples. When using {sup 210}Pb as a tracer it is necessary to determine its excess portion, which is not supported by ingrowth from the parent nuclide {sup 226}Ra. Its analysis is mostly performed via short lived daughter isotopes that follow after the intermediate gaseous member {sup 222}Rn. Preventing the escape of radon from the sample is a critical step before analysis due to a negative effect of supported {sup 210}Pb underestimation on the chronology, which was also documented in this thesis. Time series registering ingrowth of {sup 214}Pb and {sup 214}Bi towards radioactive equilibrium with {sup 226}Ra in different containers were evaluated for analyses of {sup 226}Ra. Direct analyses of {sup 226}Ra was compared to its detection via daughter products. A method for aligning parallel radionuclide depth profiles was described and applied successfully in two case studies from the continental slope off NW Africa and off Sumba Island, Indonesia. This is primarily important

  2. Synthesis and Characterization of the in Situ Bulk Polymerization of PMMA Containing Graphene Sheets Using Microwave Irradiation

    Directory of Open Access Journals (Sweden)

    Mohammad A. Aldosari

    2013-03-01

    Full Text Available Polymethylmethacrylate–graphene (PMMA/RGO nanocomposites were prepared via in situ bulk polymerization using two different preparation techniques. In the first approach, a mixture of graphite oxide (GO and methylmethacrylate monomers (MMA were polymerized using a bulk polymerization method with a free radical initiator. After the addition of the reducing agent hydrazine hydrate (HH, the product was reduced via microwave irradiation (MWI to obtain R-(GO-PMMA composites. In the second approach, a mixture of graphite sheets (RGO and MMA monomers were polymerized using a bulk polymerization method with a free radical initiator to obtain RGO-(PMMA composites. The composites were characterized by FTIR, 1H-NMR and Raman spectroscopy and XRD, SEM, TEM, TGA and DSC. The results indicate that the composite obtained using the first approach, which involved MWI, had a better morphology and dispersion with enhanced thermal stability compared with the composites prepared without MWI.

  3. In situ scanning tunneling microscopy study of Ca-modified rutile TiO2(110 in bulk water

    Directory of Open Access Journals (Sweden)

    Giulia Serrano

    2015-02-01

    Full Text Available Despite the rising technological interest in the use of calcium-modified TiO2 surfaces in biomedical implants, the Ca/TiO2 interface has not been studied in an aqueous environment. This investigation is the first report on the use of in situ scanning tunneling microscopy (STM to study calcium-modified rutile TiO2(110 surfaces immersed in high purity water. The TiO2 surface was prepared under ultrahigh vacuum (UHV with repeated sputtering/annealing cycles. Low energy electron diffraction (LEED analysis shows a pattern typical for the surface segregation of calcium, which is present as an impurity on the TiO2 bulk. In situ STM images of the surface in bulk water exhibit one-dimensional rows of segregated calcium regularly aligned with the [001] crystal direction. The in situ-characterized morphology and structure of this Ca-modified TiO2 surface are discussed and compared with UHV-STM results from the literature. Prolonged immersion (two days in the liquid leads to degradation of the overlayer, resulting in a disordered surface. X-ray photoelectron spectroscopy, performed after immersion in water, confirms the presence of calcium.

  4. Structural Characterization of Carbon Nanomaterial Film In Situ Synthesized on Various Bulk Metals

    Directory of Open Access Journals (Sweden)

    J. Y. Xu

    2014-01-01

    Full Text Available Carbon nanofiber films were prepared via a simple chemical vapor deposition (CVD method on various bulk metal substrates including bulk 316 L stainless steel, pure cobalt, and pure nickel treated by surface mechanical attrition treatment (SMAT. The microstructures of the carbon nanomaterial film were studied by SEM, TEM, XRD, and Raman spectroscopy. In this paper, bulk metallic materials treated by SMAT served as substrates as well as catalysts for carbon nanomaterial film formation. The results indicate that the carbon nanofiber films are formed concerning the catalytic effects of the refined metallic particles during CVD on the surface of SMAT-treated bulk metal substrates. However, distinguished morphologies of carbon nanomaterial film are displayed in the case of the diverse bulk metal substrates.

  5. In-situ study of crystallization kinetics in ternary bulk metallic glass alloys with different glass forming abilities

    Science.gov (United States)

    Lan, Si; Wei, Xiaoya; Zhou, Jie; Lu, Zhaoping; Wu, Xuelian; Feygenson, Mikhail; Neuefeind, Jörg; Wang, Xun-Li

    2014-11-01

    In-situ transmission electron microcopy and time-resolved neutron diffraction were used to study crystallization kinetics of two ternary bulk metallic glasses during isothermal annealing in the supercooled liquid region. It is found that the crystallization of Zr56Cu36Al8, an average glass former, follows continuous nucleation and growth, while that of Zr46Cu46Al8, a better glass former, is characterized by site-saturated nucleation, followed by slow growth. Possible mechanisms for the observed differences and the relationship to the glass forming ability are discussed.

  6. In-situ study of crystallization kinetics in ternary bulk metallic glass alloys with different glass forming abilities

    Energy Technology Data Exchange (ETDEWEB)

    Lan, Si; Wei, Xiaoya; Wu, Xuelian; Wang, Xun-Li, E-mail: xlwang@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong, 83 Tat Chee Ave., Kowloon (Hong Kong); Zhou, Jie; Lu, Zhaoping [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing (China); Feygenson, Mikhail; Neuefeind, Jörg [Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2014-11-17

    In-situ transmission electron microcopy and time-resolved neutron diffraction were used to study crystallization kinetics of two ternary bulk metallic glasses during isothermal annealing in the supercooled liquid region. It is found that the crystallization of Zr{sub 56}Cu{sub 36}Al{sub 8}, an average glass former, follows continuous nucleation and growth, while that of Zr{sub 46}Cu{sub 46}Al{sub 8}, a better glass former, is characterized by site-saturated nucleation, followed by slow growth. Possible mechanisms for the observed differences and the relationship to the glass forming ability are discussed.

  7. Crystalline phase transition information induced by high temperature susceptibility transformations in bulk PMP-YBCO superconductor growth in-situ

    Science.gov (United States)

    Zhang, C. P.; Chaud, X.; Beaugnon, E.; Zhou, L.

    2015-01-01

    The dynamic susceptibility transformations of bulk HTSC PMP-YBCO growth have been investigated from 200 °C up to 1060 °C by the Faraday Balance in-situ. It revealed that the crystalline phase transitions of bulk PMP-YBCO growth in process. A new discovery of Y123 phase pre-formed then melted in heating stage has been found. It also discovered that Y123 crystal solidification started at 1004 °C in cooling stage. Before Y123 solidification the liquid phase CuO change to Cu2O reciprocally as well as the copper ion valence changed between divalent Cu2+ and trivalent Cu1+ each other. It was essential to keep quantities of CuO phase instead of the Cu2O for Y123 crystal solidification.

  8. Genomic and in situ investigations of the novel uncultured Chloroflexi associated with 0092 morphotype filamentous bulking in activated sludge.

    Science.gov (United States)

    McIlroy, Simon Jon; Karst, Søren Michael; Nierychlo, Marta; Dueholm, Morten Simonsen; Albertsen, Mads; Kirkegaard, Rasmus Hansen; Seviour, Robert James; Nielsen, Per Halkjær

    2016-09-01

    Overgrowth of filamentous bacteria in activated sludge wastewater treatment plants (WWTPs) leads to impaired sludge settleability, a condition known as bulking, which is a common operational problem worldwide. Filaments with the Eikelboom 0092 morphotype are commonly associated with such bulking episodes. Members of the uncultured B45 phylotype, which is embraced within the phylum Chloroflexi, were recently shown to exhibit this morphology. Although these organisms are among the most abundant populations recorded in activated sludge processes, nothing is known about their metabolic characteristics. In this study, a genome sequence, representing the B45 phylotype, was retrieved from a metagenome generated from an activated sludge WWTP. The genome consisted of two chromosomes and one plasmid, which were 4.0, 1.0 and 0.04 Mbps in size, respectively. A metabolic model was constructed for this organism, based on annotation of its genome, showing its ability to generate energy by respiration, utilizing oxygen, nitrite or nitrous oxide as electron acceptors, or by fermentation of sugars. The ability of B45 members to ferment sugars under anaerobic conditions was validated in situ with microautoradiography-fluorescence in situ hybridization. The provisional name of 'Candidatus Promineofilum breve' is proposed for this species. This study represents the first detailed information on an uncultured genus of filamentous organisms from activated sludge.

  9. Crystalline phase transition information induced by high temperature susceptibility transformations in bulk PMP-YBCO superconductor growth in-situ

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, C.P., E-mail: zhangcp6813@126.com [SMRC, Northwest Institute for Non-ferrous Metal Research, Xi’an (China); Physics Department, Université Joseph Fourier, Grenoble (France); State Key Lab of Solidification Processing, Northwest Polytechnical University, Xi’an (China); Chaud, X. [CRETA/CNRS, 25 avenue des martyrs, 38042 Grenoble Cedex 9 (France); Beaugnon, E. [Physics Department, Université Joseph Fourier, Grenoble (France); CRETA/CNRS, 25 avenue des martyrs, 38042 Grenoble Cedex 9 (France); Zhou, L. [SMRC, Northwest Institute for Non-ferrous Metal Research, Xi’an (China); State Key Lab of Solidification Processing, Northwest Polytechnical University, Xi’an (China)

    2015-01-15

    Highlights: • It was the first time we measured the susceptibility of bulk YBCO in powder-melting-process at high temperature up to 1060 °C. • It revealed that the crystalline phase transition of bulk PMP-YBCO growth in process. • A new discovery of Y123 phase pre-formed then melted in heating stage has been found. • It discovered that Y123 crystal solidification started at 1004 °C in cooling stage in PMP route. - Abstract: The dynamic susceptibility transformations of bulk HTSC PMP-YBCO growth have been investigated from 200 °C up to 1060 °C by the Faraday Balance in-situ. It revealed that the crystalline phase transitions of bulk PMP-YBCO growth in process. A new discovery of Y123 phase pre-formed then melted in heating stage has been found. It also discovered that Y123 crystal solidification started at 1004 °C in cooling stage. Before Y123 solidification the liquid phase CuO change to Cu{sub 2}O reciprocally as well as the copper ion valence changed between divalent Cu{sup 2+} and trivalent Cu{sup 1+} each other. It was essential to keep quantities of CuO phase instead of the Cu{sub 2}O for Y123 crystal solidification.

  10. Bulk conductivity measurement of paper by a new in situ pressure cell

    Science.gov (United States)

    Josefowicz, Jack Y.; Anczurowski, Edward; Jones, Arthur Y.; Deslandes, Yves

    1981-06-01

    In this report a new bulk conductivity cell design is described which can be used to characterize both conductivized and nonconductive paper. By the use of optically flat stainless steel electrodes under a pressure of 115 bars during the conductivity measurement, it is shown that the contact resistance between the paper sample and the electrodes is reduced to negligible proportions. The effect of paper surface morphology on the contact resistance during the measurement of bulk conductivity was studied by a comparison between the polished stainless steel electrodes and electrodes composed of liquid Galium Indium, which make intimate contact with the paper surface. Bulk conductivity measurements were determined for paper samples having different basis weights and different degrees of calendering. The results obtained with the pressurized stainless steel electrodes for these paper samples indicate that the contact resistance is essentially eliminated for all the papers studied by using an applied pressure of 115 bars.

  11. Decoupling Bulk and Surface Contributions in Water- Splitting Photocatalysts by In Situ Ultrafast Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Appavoo, Kannatassen [Brookhaven National Lab. (BNL), Upton, NY (United States). Center for Functional Nanomaterials; Mingzhao, Liu [Brookhaven National Lab. (BNL), Upton, NY (United States). Center for Functional Nanomaterials; Black, Charles T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Center for Functional Nanomaterials; Sfeir, Matthew Y. [Brookhaven National Lab. (BNL), Upton, NY (United States). Center for Functional Nanomaterials

    2015-05-10

    By performing ultrafast emission spectroscopy in an operating, bias-controlled photoelectrochemical cell, we distinguish between bulk (charge transport) and surface (chemical reaction) recombination processes in a nanostructured photocatalyst and correlate its electronic properties directly with its incident-photon-to-current efficiency.

  12. In-situ studies of bulk deformation structures: Static properties under load and dynamics during deformation

    DEFF Research Database (Denmark)

    Jakobsen, Bo

    2006-01-01

    The main goal of the study presented in this thesis was to perform in-situ investigations on deformation structures in plastically deformed polycrystalline copper at low degrees of tensile deformation (metals. Anovel synchrotron...... grains in polycrystalline samples during tensile deformation. We have shown that the resulting 3D reciprocal space maps from tensile deformed copper comprise a pronounced structure, consisting of bright sharp peaks superimposed on a cloud of enhanced intensity. Based on the integrated intensity......, the width of the peaks, and spatial scanning experiments it is concluded that the individual peaks arise from individual dislocation-free regions (the subgrains) in the dislocation structure. The cloud is attributed to the dislocation rich walls. Samples deformed to 2% tensile strain were investigated under...

  13. A novel in situ device based on a bionic piezoelectric actuator to study tensile and fatigue properties of bulk materials

    Science.gov (United States)

    Wang, Shupeng; Zhang, Zhihui; Ren, Luquan; Zhao, Hongwei; Liang, Yunhong; Zhu, Bing

    2014-06-01

    In this work, a miniaturized device based on a bionic piezoelectric actuator was developed to investigate the static tensile and dynamic fatigue properties of bulk materials. The device mainly consists of a bionic stepping piezoelectric actuator based on wedge block clamping, a pair of grippers, and a set of precise signal test system. Tensile and fatigue examinations share a set of driving system and a set of signal test system. In situ tensile and fatigue examinations under scanning electron microscope or metallographic microscope could be carried out due to the miniaturized dimensions of the device. The structure and working principle of the device were discussed and the effects of output difference between two piezoelectric stacks on the device were theoretically analyzed. The tensile and fatigue examinations on ordinary copper were carried out using this device and its feasibility was verified through the comparison tests with a commercial tensile examination instrument.

  14. Enhanced plasticity of Zr-based bulk metallic glass composite by in situ formed β-Zr dendritics

    Institute of Scientific and Technical Information of China (English)

    SUN Guoyuan; CHEN Guang; CHEN Guoliang

    2007-01-01

    A Zr56.2Ti13.8Nb5.0Cu6.9Ni5.6Be12.5 bulk metallic glasscomposite with enhanced plasticity by in situ formed bcc β-Zr solid solution was prepared by water quenching.The ductile βphase with a volume fraction of about 30% possesses a developed dendritic morphology.The composite exhibits a pure plastic strain of 10.2% combined with a large elastic strain limit of 2% and a high ultimate strength of 1778 Mpa upon room-temperature compression.Microscopic observa- tion shows numbers of wave-like shear bands distributed on the surface of the compressive samples.

  15. Ferroferric oxide/polystyrene (Fe3O4/PS superparamagnetic nanocomposite via facile in situ bulk radical polymerization

    Directory of Open Access Journals (Sweden)

    2010-03-01

    Full Text Available Organo-modified ferroferric oxide superparamagnetic nanoparticles, synthesized by the coprecipitation of superparamagnetic nanoparticles in presence of oleic acid (OA, were incorporated in polystyrene (PS by the facile in situ bulk radical polymerization by using 2,2-azobisisobutyronitrile (AIBN as initiator. The transmission electron microscopy (TEM analysis of the resultant uniform ferroferric oxide/polystyrene superparamagnetic nanocomposite (Fe3O4/PS showed that the superparamagnetic nanoparticles had been dispersed homogeneously in the polymer matrix due to the surface grafted polystyrene, confirmed by Fourier transform infrared (FT-IR spectroscopy and thermogravimetric analysis (TGA. The superparamagnetic property of the Fe3O4/PS nanocomposite was testified by the vibrating sample magnetometer (VSM analysis. The strategy developed is expected to be applied for the large-scale industrial manufacturing of the superparamagnetic polymer nanocomposite.

  16. A novel in situ device based on a bionic piezoelectric actuator to study tensile and fatigue properties of bulk materials

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shupeng; Zhang, Zhihui, E-mail: zhzh@jlu.edu.cn; Ren, Luquan; Liang, Yunhong [The Key Laboratory of Engineering Bionics (Ministry of Education) and the College of Biological and Agricultural Engineering, Jilin University (Nanling Campus), 5988 Renmin Street, Changchun 130025 (China); Zhao, Hongwei [College of Mechanical Science and Engineering, Jilin University (Nanling Campus), 5988 Renmin Street, Changchun 130025 (China); Zhu, Bing [College of Automotive Engineering, Jilin University (Nanling Campus), 5988 Renmin Street, Changchun 130025 (China)

    2014-06-15

    In this work, a miniaturized device based on a bionic piezoelectric actuator was developed to investigate the static tensile and dynamic fatigue properties of bulk materials. The device mainly consists of a bionic stepping piezoelectric actuator based on wedge block clamping, a pair of grippers, and a set of precise signal test system. Tensile and fatigue examinations share a set of driving system and a set of signal test system. In situ tensile and fatigue examinations under scanning electron microscope or metallographic microscope could be carried out due to the miniaturized dimensions of the device. The structure and working principle of the device were discussed and the effects of output difference between two piezoelectric stacks on the device were theoretically analyzed. The tensile and fatigue examinations on ordinary copper were carried out using this device and its feasibility was verified through the comparison tests with a commercial tensile examination instrument.

  17. A novel in situ device based on a bionic piezoelectric actuator to study tensile and fatigue properties of bulk materials.

    Science.gov (United States)

    Wang, Shupeng; Zhang, Zhihui; Ren, Luquan; Zhao, Hongwei; Liang, Yunhong; Zhu, Bing

    2014-06-01

    In this work, a miniaturized device based on a bionic piezoelectric actuator was developed to investigate the static tensile and dynamic fatigue properties of bulk materials. The device mainly consists of a bionic stepping piezoelectric actuator based on wedge block clamping, a pair of grippers, and a set of precise signal test system. Tensile and fatigue examinations share a set of driving system and a set of signal test system. In situ tensile and fatigue examinations under scanning electron microscope or metallographic microscope could be carried out due to the miniaturized dimensions of the device. The structure and working principle of the device were discussed and the effects of output difference between two piezoelectric stacks on the device were theoretically analyzed. The tensile and fatigue examinations on ordinary copper were carried out using this device and its feasibility was verified through the comparison tests with a commercial tensile examination instrument.

  18. In situ synthesis of TiC reinforced Cu47Ti34Zr11Ni8 bulk metallic glass composites

    Institute of Scientific and Technical Information of China (English)

    SUN Yufeng; ZHANG Guosheng; WEI Bingchen; LI Weihuo; WANG Yuren

    2004-01-01

    In situ synthesized TiC particles and β-Ti dendrites reinforced Cu47Ti34Zr11 Ni8 bulk metallic glass (BMG)composite ingots were prepared by the suction casting method. The ingots with diameters from 1 up to 4 mm were successfully obtained. It was shown that introducing TiC micro-sized particles into the amorphous matrix did not disturb the glass forming ability (GFA) of the matrix, while the yield strength and ductility could be well improved. The phase constitution, microstructure and elements distribution in the composites were studied by OM, XRD, SEM and EDS.It was shown that the in situ synthesized TiC particles acting as heterogeneous nucleation sites promoted the precipitation of β-Ti dendrites, resulting in the formation of the TiC particles and β-Ti dendrites co-reinforced BMG composites. The compressive tests were employed to probe the yield strength and ductility of BMG composites.

  19. In-situ visualization of stress-dependent bulk magnetic domain formation by neutron grating interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Betz, B. [Paul Scherrer Institut, Laboratory for Neutron Scattering and Imaging, CH-5232 Villigen (Switzerland); École Polytechnique Fédérale de Lausanne, NXMM Laboratory, IMX, CH-1015 Lausanne (Switzerland); Rauscher, P. [Fraunhofer IWS Dresden, Laser Ablation and Cutting, D-01277 Dresden (Germany); Harti, R. P.; Kaestner, A.; Hovind, J.; Lehmann, E.; Grünzweig, C. [Paul Scherrer Institut, Laboratory for Neutron Scattering and Imaging, CH-5232 Villigen (Switzerland); Schäfer, R. [Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Helmholzstr.20, D-01069 Dresden, Germany and Institute for Materials Science, University of Technology, D-01069 Dresden (Germany); Van Swygenhoven, H. [École Polytechnique Fédérale de Lausanne, NXMM Laboratory, IMX, CH-1015 Lausanne (Switzerland); Paul Scherrer Institut, Photons for Engineering and Manufacturing, CH-5232 Villigen (Switzerland)

    2016-01-04

    The performance and degree of efficiency of industrial transformers are directly influenced by the magnetic properties of high-permeability steel laminations (HPSLs). Industrial transformer cores are built of stacks of single HPSLs. While the insulating coating on each HPSL reduces eddy-current losses in the transformer core, the coating also induces favorable inter-granular tensile stresses that significantly influence the underlying magnetic domain structure. Here, we show that the neutron dark-field image can be used to analyze the influence of the coating on the volume and supplementary surface magnetic domain structures. To visualize the stress effect of the coating on the bulk domain formation, we used an uncoated HPSL and stepwise increased the applied external tensile stress up to 20 MPa. We imaged the domain configuration of the intermediate stress states and were able to reproduce the original domain structure of the coated state. Furthermore, we were able to visualize how the applied stresses lead to a refinement of the volume domain structure and the suppression and reoccurrence of supplementary domains.

  20. Endoscopic fringe projection for in-situ inspection of a sheet-bulk metal forming process

    Science.gov (United States)

    Matthias, Steffen; Kästner, Markus; Reithmeier, Eduard

    2015-05-01

    Sheet-bulk metal forming is a new production process capable of performing deep-drawing and massive forming steps in a single operation. However, due to the high forming forces of the forming process, continuous process control is required in order to detect wear on the forming tool before production quality is impacted. To be able to measure the geometry of the forming tool in the limited space of forming presses, a new inspection system is being developed within the SFB/TR 73 collaborative research center. In addition to the limited space, the process restricts the amount of time available for inspection. Existing areal optical measurement systems suffer from shadowing when measuring the tool's inner elements, as they cannot be placed in the limited space next to the tool, while tactile measurement systems cannot meet the time restrictions for measuring the areal geometries. The new inspection system uses the fringe projection optical measurement principle to capture areal geometry data from relevant parts of the forming tool in short time. Highresolution image fibers are used to connect the system's compact sensor head to a base unit containing both camera and projector of the fringe projection system, which can be positioned outside of the moving parts of the press. To enable short measurement times, a high intensity laser source is used in the projector in combination with a digital micro-mirror device. Gradient index lenses are featured in the sensor head to allow for a very compact design that can be used in the narrow space above the forming tool inside the press. The sensor head is attached to an extended arm, which also guides the image fibers to the base unit. A rotation stage offers the possibility to capture measurements of different functional elements on the circular forming tool by changing the orientation of the sensor head next to the forming tool. During operation of the press, the arm can be travelled out of the moving parts of the forming press

  1. Airborne gamma spectrometry--towards integration of European operational capability.

    Science.gov (United States)

    Toivonen, Harri

    2004-01-01

    Airborne gamma spectrometry is an excellent tool for finding out in a timely manner the extent and magnitude of the dispersion of radioactive materials resulting from a nuclear disaster. To utilise existing European airborne monitoring capabilities for multilateral assistance in an accident is a complex administrative and technical matter. Several international exercises have been organised demonstrating the capability to cooperate. However, efficient mutual assistance between European countries requires conceptual work, standards and harmonisation of software. A unified radiological vocabulary and data exchange format in XML need to be developed. A comprehensive database is essential for data assimilation. An operations centre is needed for management and planning of surveys.

  2. Isotope dilution gamma spectrometry for Pu using low energy photons

    Energy Technology Data Exchange (ETDEWEB)

    Paul, S.; Sarkar, A.; Alamelu, D.; Shah, R.V.; Aggarwal, S.K. [Bhabha Atomic Reseach Centre, Mumbai (India). Fuel Chemistry Div.

    2012-07-01

    Isotope dilution gamma spectrometry (IDGS) for determination of the Pu concentration, using high resolution gamma-ray spectrometry (HRGS) in the 40-150 keV energy range, is developed and described. The methodology involves purification of Pu by an anion exchange procedure, followed by the determination of Pu isotopic composition using HRGS. For isotope dilution, a pre-calibrated power reactor grade Pu ({proportional_to} 70 at. % {sup 239}Pu) solution from an Indian PHWR was used as a spike for research reactor grade Pu ({proportional_to} 95 at. % {sup 239}Pu) samples and vice versa. Changes in {sup 240}Pu/{sup 239}Pu (45.24 keV/51.62 keV) and {sup 241}Pu/{sup 239}Pu (148.57 keV/129.29 keV) activity ratios in the spiked samples were determined by gamma spectrometry. Using the atom ratios calculated from the measured activity ratios, the concentration of Pu in the sample was calculated using two different efficiency calibration methods. The isotopic composition and concentration of Pu samples both from power reactor and research reactor grade agreed well with the values obtained by isotope dilution-thermal ionization mass spectrometry. The present method also shows the superiority of using the {sup 240}Pu/{sup 239}Pu atom ratio against the {sup 241}Pu/{sup 239}Pu atom ratio in IDGS with respect to the accuracy and precision. (orig.)

  3. Layered double hydroxides as fillers in poly(l-lactide nanocomposites, obtained by in situ bulk polymerization

    Directory of Open Access Journals (Sweden)

    Telma Nogueira

    2016-01-01

    Full Text Available Abstract In this study in situ bulk polymerization of L-lactide filled with layered double hydroxides (LDH was investigated. Four different LDHs intercalated with two different organic anions (salicylate and sebacate were synthesized and characterized. After characterization, these synthetic layered compounds were used as fillers in poly(L-lactide (PLLA nanocomposites with two different fillers’s loadings (1 wt% and 2 wt%. PLLA and PLLA nanocomposites were evaluated by X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, ultraviolet and visible spectroscopy, thermogravimetric analysis (TGA, dynamical mechanical analysis (DMA, flexural testing and differential scanning calorimetry (DSC. The results demonstrated that, compared to PLLA, the nanocomposite containing 1 wt% of Zn/Al salicylate transmitted less UVA and UVB light, while keeping a similar transparency in the visible region. Thermogravimetric analysis revealed that the nanocomposite with 1 wt% of Zn/Al salicylate exhibited the highest thermal stability. In general the flexural and dynamical mechanical properties were reduced in compassion to neat PLLA. DSC results, demonstrated that, compared to PLLA, all the nanocomposites exhibited lower glass transition temperature and melting temperature values.

  4. Layered double hydroxides as fillers in poly(l-lactide nanocomposites, obtained by in situ bulk polymerization

    Directory of Open Access Journals (Sweden)

    Telma Nogueira

    Full Text Available Abstract In this study in situ bulk polymerization of L-lactide filled with layered double hydroxides (LDH was investigated. Four different LDHs intercalated with two different organic anions (salicylate and sebacate were synthesized and characterized. After characterization, these synthetic layered compounds were used as fillers in poly(L-lactide (PLLA nanocomposites with two different fillers’s loadings (1 wt% and 2 wt%. PLLA and PLLA nanocomposites were evaluated by X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, ultraviolet and visible spectroscopy, thermogravimetric analysis (TGA, dynamical mechanical analysis (DMA, flexural testing and differential scanning calorimetry (DSC. The results demonstrated that, compared to PLLA, the nanocomposite containing 1 wt% of Zn/Al salicylate transmitted less UVA and UVB light, while keeping a similar transparency in the visible region. Thermogravimetric analysis revealed that the nanocomposite with 1 wt% of Zn/Al salicylate exhibited the highest thermal stability. In general the flexural and dynamical mechanical properties were reduced in compassion to neat PLLA. DSC results, demonstrated that, compared to PLLA, all the nanocomposites exhibited lower glass transition temperature and melting temperature values.

  5. A new system for sodium flux growth of bulk GaN. Part II: in situ investigation of growth processes

    Science.gov (United States)

    Von Dollen, Paul; Pimputkar, Siddha; Alreesh, Mohammed Abo; Nakamura, Shuji; Speck, James S.

    2016-12-01

    We report recent results of bulk GaN crystal growth using the sodium flux method in a new crucible-free growth system. We observed a (0001) Ga face (+c-plane) growth rate >50 μm/h for growth at a N2 overpressure of 5 MPa and 860 °C, which is the highest crystal growth rate reported for this technique to date. Omega X-ray rocking curve (ω-XRC) measurements indicated the presence of multiple grains, though full width at half maximum (FWHM) values for individual peaks were 100 arcseconds. Oxygen impurity concentrations as measured by secondary ion mass spectroscopy (SIMS) were >1020 atoms/cm3. By monitoring the nitrogen pressure decay over the course of the crystal growth, we developed an in situ method that correlates gas phase changes with precipitation of GaN from the sodium-gallium melt. Based on this analysis, the growth rate may have actually been as high as 90 μm/h, as it would suggest GaN growth ceased prior to the end of the run. We also observed gas phase behavior identified as likely characteristic of GaN polynucleation.

  6. In-situ investigation of the hydrogen release mechanism in bulk Mg2NiH4

    Science.gov (United States)

    Tran, Xuan Quy; McDonald, Stuart D.; Gu, Qinfen; Yamamoto, Tomokazu; Shigematsu, Koji; Aso, Kohei; Tanaka, Eishi; Matsumura, Syo; Nogita, Kazuhiro

    2017-02-01

    Hydrogen storage is an important aspect to enable the so-called hydrogen economy. Mg-Ni alloys are among the most promising candidates for solid-state hydrogen storage systems yet many questions remain unanswered regarding the hydriding/dehydriding mechanism of the alloys. Mg2NiH4 particularly has received much attention both for its potential as a hydrogen storage medium and also exhibits interesting properties relating to its different polymorphs. Here, the dehydriding mechanism in bulk Mg2NiH4 is investigated using in-situ ultra-high voltage transmission electron microscopy (TEM) combined with Synchrotron powder X-ray diffraction (XRPD) and differential scanning calorimetry (DSC). We find that the hydrogen release is based on a mechanism of nucleation and growth of Mg2NiHx (x∼0-0.3) solid solution grains and is greatly enhanced in the presence of crystal defects occurring as a result of the polymorphic phase transformation. Also importantly, with atomic resolution TEM imaging a high density of stacking faults is identified in the dehydrided Mg2NiHx (x∼0-0.3) lattices.

  7. Improved properties of chemically modified graphene/poly(methyl methacrylate nanocomposites via a facile in-situ bulk polymerization

    Directory of Open Access Journals (Sweden)

    X. Y. Yuan

    2012-10-01

    Full Text Available The nanosheet of graphene was chemically modified by long alkyl chain for enhanced compatibility with polymer matrix and graphene/poly(methyl methacrylate (PMMA nanocomposites with homogeneous dispersion of the nanosheets and enhanced nanofiller-matrix interfacial interaction were fabricated via a facile in-situ bulk polymerization. The nanocomposites were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Scanning electron microscopy and thermogravimetry. The results showed that the graphene nanosheets were fully exfoliated in PMMA matrix and the thermal and mechanical properties of the nanocomposites were significantly improved at low graphene loadings. Large shifts of 15°C in the glass transition temperature and 27°C improvement of onset thermal degradation temperature were achieved with graphene loading as low as 0.07 wt%. A 67% increase in tensile strength was also observed by the addition of only 0.5 wt% graphene. The method used in this study provided a novel route to other graphene-based polymers.

  8. In situ morphology studies of the mechanism for solution additive effects on the formation of bulk heterojunction films

    KAUST Repository

    Richter, Lee J.

    2014-09-29

    The most successful active film morphology in organic photovoltaics is the bulk heterojunction (BHJ). The performance of a BHJ arises from a complex interplay of the spatial organization of the segregated donor and acceptor phases and the local order/quality of the respective phases. These critical morphological features develop dynamically during film formation, and it has become common practice to control them by the introduction of processing additives. Here, in situ grazing incidence X-ray diffraction (GIXD) and grazing incidence small angle X-ray scattering (GISAXS) studies of the development of order in BHJ films formed from the donor polymer poly(3-hexylthiophene) and acceptor phenyl-C61-butyric acid methyl ester under the influence of two common additives, 1,8-octanedithiol and 1-chloronaphthalene, are reported. By comparing optical aggregation to crystallization and using GISAXS to determine the number and nature of phases present during drying, two common mechanisms by which the additives increase P3HT crystallinity are identified. Additives accelerate the appearance of pre-crystalline nuclei by controlling solvent quality and allow for extended crystal growth by delaying the onset of PCBM-induced vitrification. The glass transition effects vary system-to-system and may be correlated to the number and composition of phases present during drying. Synchrotron X-ray scattering measurements of nanoscale structure evolution during the drying of polymer-fullerene photovoltaic films are described. Changes in the number and nature of phases, as well as the order within them, reveals the mechanisms by which formulation additives promote structural characteristics leading to higher power conversion efficiencies.

  9. A simple gamma spectrometry method for evaluating the burnup of MTR-type HEU fuel elements

    Science.gov (United States)

    Makmal, T.; Aviv, O.; Gilad, E.

    2016-10-01

    A simple method for the evaluation of the burnup of a materials testing reactor (MTR) fuel element by gamma spectrometry is presented. The method was applied to a highly enriched uranium MTR nuclear fuel element that was irradiated in a 5 MW pool-type research reactor for a total period of 34 years. The experimental approach is based on in-situ measurements of the MTR fuel element in the reactor pool by a portable high-purity germanium detector located in a gamma cell. To corroborate the method, analytical calculations (based on the irradiation history of the fuel element) and computer simulations using a dedicated fuel cycle burnup code ORIGEN2 were performed. The burnup of the MTR fuel element was found to be 52.4±8.8%, which is in good agreement with the analytical calculations and the computer simulations. The method presented here is suitable for research reactors with either a regular or an irregular irradiation regime and for reactors with limited infrastructure and/or resources. In addition, its simplicity and the enhanced safety it confers may render this method suitable for IAEA inspectors in fuel element burnup assessments during on-site inspections.

  10. Mapping strain fields induced in Zr-based bulk metallic glasses during in-situ nanoindentation by X-ray nanodiffraction

    Energy Technology Data Exchange (ETDEWEB)

    Gamcová, J.; Bednarčík, J.; Franz, H. [DESY, Notkestraße 85, Hamburg 22547 (Germany); Mohanty, G.; Wehrs, J.; Michler, J. [Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Mechanics of Materials and Nanostructures, Feuerwerkerstraße 39, Thun 3602 (Switzerland); Michalik, Š. [Institute of Physics ASCR, Na Slovance 2, Praha 18221 (Czech Republic); Krywka, C. [HZG, Institut für Werkstoffforschung, Notkestraße 85, Hamburg 22547 (Germany); Breguet, J. M. [Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Mechanics of Materials and Nanostructures, Feuerwerkerstraße 39, Thun 3602 (Switzerland); Alemnis GmbH, Feuerwerkerstraße 39, Thun 3602 (Switzerland)

    2016-01-18

    A pioneer in-situ synchrotron X-ray nanodiffraction approach for characterization and visualization of strain fields induced by nanoindentation in amorphous materials is introduced. In-situ nanoindentation experiments were performed in transmission mode using a monochromatic and highly focused sub-micron X-ray beam on 40 μm thick Zr-based bulk metallic glass under two loading conditions. Spatially resolved X-ray diffraction scans in the deformed volume of Zr-based bulk metallic glass covering an area of 40 × 40 μm{sup 2} beneath the pyramidal indenter revealed two-dimensional map of elastic strains. The largest value of compressive elastic strain calculated from diffraction data at 1 N load was −0.65%. The region of high elastic compressive strains (<−0.3%) is located beneath the indenter tip and has radius of 7 μm.

  11. Quantitative radiological characterization of waste. Integration of gamma spectrometry and passive/active neutron assay

    Energy Technology Data Exchange (ETDEWEB)

    Simone, Gianluca; Mauro, Egidio; Gagliardi, Filippo; Gorello, Edoardo [Nucleco S.p.A., Rome (Italy)

    2016-06-15

    The radiological characterization of drums through Non-Destructive Assay (NDA) techniques commonly relies on gamma spectrometry. This paper introduces the procedure developed in Nucleco for the NDA radiological characterization of drums when the presence of Special Nuclear Material (SNM) is expected/observed. The procedure is based on the integration of a gamma spectrometry in SGS mode (Segmented Gamma Scanner) and a passive/active neutron assay. The application of this procedure is discussed on a real case of drums. The extension of the integration procedure to other gamma spectrometry systems is also discussed.

  12. Genomic and in situ investigations of the novel uncultured Chloroflexi associated with 0092 morphotype filamentous bulking in activated sludge

    DEFF Research Database (Denmark)

    McIlroy, Simon Jon; Karst, Søren Michael; Nierychlo, Marta;

    2016-01-01

    Overgrowth of filamentous bacteria in activated sludge wastewater treatment plants (WWTPs) leads to impaired sludge settleability, a condition known as bulking, which is a common operational problem worldwide. Filaments with the Eikelboom 0092 morphotype are commonly associated with such bulking...

  13. A Field Test of the New Portable Gamma Spectrometry System

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jung-Ki; Park, Uk Ryang; Park, Seunghoon; Chung, Heejun; Kwak, Sung-Woo [Korea Institute of Nuclear Non-proliferation and Control, Daejeon (Korea, Republic of); Kim, Yongkwn [NuCare Medical Systems, Inc., Incheon (Korea, Republic of)

    2015-10-15

    In order to perform a field test of the system, the measurement of U-235 enrichment for nuclear fuel pellets was conducted along with the IAEA Physical Inventory Verification (PIV) inspection at the KEPCO Nuclear Fuel (KNF). The enrichment value of U-235 was calculated based on the total counts of the 185.7 keV photopeak and compared with the reference line, drawn by certified sources. The goal of this study is to experimentally evaluate the system performance of the developed system. In this study, the new portable gamma spectrometry system showed a good linearity (R{sup 2}=1) but overestimated the enrichment values than IAEA inspection device. It could be caused by the stability of the new system since it found, right after this measurement, that the accuracy of the system gradually increases and becomes stable over time. Further steps will optimize the design parameter based on these results and repeat measurement with the same samples under the same environment.

  14. Results from the RESUME-95 exercise. In-situ gamma spectrometry performed at Vesivehmaa Airport, Finland

    Energy Technology Data Exchange (ETDEWEB)

    Raeaef, C.L. [Univ. Hospital MAS, Lund Univ., Dept. of Radiation Physics, Malmoe (Sweden)

    1997-12-31

    The Department of Radiation Physics in Malmoe has an agreement with the Swedish Radiation Protection Institute, in which we are obliged to perform instantaneous field measurements of gamma-emitting radionuclides in case of a major release of radionuclides in the environment. The department possesses a High Purity Germanium detector system (35 % commercial at 1.33 MeV) with a PC software spectrum analyser that was purchased and calibrated for this reason. The aim of our participation in the RESUME-95{sup 1} exercise, which took place in Vaeaexsy, Finland, in August 1995, was both to obtain efficiency values for different source geometries (both artificial and natural radionuclides) in field and to compare our results with those of other groups. Furthermore, this exercise was an ideal opportunity to test the full equipment under field conditions. (au).

  15. GammaSem Proceedings - A Nordic seminar for users of gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Nunez, P. (ed.) (Institute for Energy Technology (IFE) (Norway)); Klemola, S. (Radiation and Nuclear Safety Authority (STUK) (Finland)); Nielsen, Sven P. (Technical Univ. of Denmark, Risoe National Lab. for Sustainable Energy. Roskilde (Denmark)); Palsson, S.E. (Icelandic Radiation Safety Authority (IS)); Israelson, C. (National Institute of Radiation Protection (Denmark))

    2010-03-15

    The project GammaSem was proposed to provide a forum for discussions and sharing of information on practical issues concerning gamma spectrometry and to establish a network of users of gamma spectrometry in the Nordic countries, thereby strengthening the collaboration and improving all participants' competence in practical gamma spectrometry. The seminars' focus was practical challenges met by the users themselves, rather than theoretical matters. Scientists and users of gamma spectrometry from all five Nordic countries were invited to the seminar, as well as scientist from the Baltic countries. A total of 75 people participated; representing 34 different universities, commercial companies, research institutes and also all Nordic authorities. During the seminar several key issues for follow-up were identified and working groups for addressing the identified problems were established. The working groups were: 1) Uncertainties and detections of limits 2) True summing coincidence 3) Monte Carlo simulations and efficiency transfer 4) Absorption (density corrections and geometries) 5) Mobile gamma spectrometry systems 6) Nuclear forensics (on special samples and special parts of the spectra). The identified topics will form the basis for the agenda of the next seminar in 2010. There, the different working groups will be invited to present their ideas/solutions to the relevant problems. (author)

  16. GammaSem Proceedings. A Nordic seminar for users of gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Straalberg, E. (ed.) (Institute for Energy Technolgy (Norway)); Berg, K. (National Institute of Radiation Protection (Denmark)); Dowdall, M. (Norwegian Radiation Protection Authority (Norway)) (and others)

    2010-11-15

    The project GammaSem was proposed to the NKS in 2008. The aim of the project was to arrange two seminars for users of gamma spectrometry, in 2009 and 2010. The seminars were meant to provide a forum for discussions and sharing of information on practical issues concerning gamma spectrometry and initiate a network of gamma spectrometry users in the Nordic countries. Such a Nordic network should strengthen the collaboration between laboratories and improve all participants' competence in practical gamma spectrometry. Both seminars' focus was practical challenges met by the users themselves, rather than theoretical matters. Scientists and users of gamma spectrometry from all five Nordic countries were invited to the seminar, as well as scientist from the Baltic countries. A total of 65 people signed up for GammaSem 2010; representing 30 different universities, commercial companies, research institutes and authorities. The working group concept as presented at last year's GammaSem, has not worked out as intended. The reason for this is probably because most of the laboratories that signed up to join the working groups, signed up because they wanted to learn more about the different subjects. In combination with the fact that no funding was made available for the working groups, it was difficult to establish goals on what to achieve. None of the working groups applied for funding from the NKS (or elsewhere) to establish separate projects. There is a big need for more cooperation and for training within the field of gamma spectrometry. This fact has been proved through these two seminars, both by the many different topics that have been discussed, but also by the huge interest for participating in the suggested series of workshop. The GammaSem seminars have thus provided a much welcomed starting point for a broader Nordic collaboration. (Author)

  17. Growth of a Copper-Gold Alloy Phase by Bulk Copper Electrodeposition on Gold Investigated by In Situ STM

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Møller, Per

    1995-01-01

    the potential in the double-layer charging region from 500 to -100 mV and back to 500 mV at a sweep rate of 1 mV/s in an acidified copper sulfate electrolyte (0.01M H2SO4, 0.01M CuSO4, and Millipore water). After completion of the first cycle the gold surface had recrystallized and nuclei of an alloy phase were...... in peak potential for the anodic current transient from E = 20 mV to E = -2 mV was observed after completion of four subsequent cycles of copper electrodeposition/dissolution. The shift is suggested to be equal to the change in potential of the working electrode owing to the formation of the alloy phase.......Simultaneous in situ scanning tunneling microscopy measurements and recordings of voltammograms were used to study in real time the initial cycles of potentiostatic copper electrodeposition and subsequent dissolution on a clean gold polycrystalline electrode. The cycles were carried out by sweeping...

  18. Mechanical properties and structure of zirconia-mullite ceramics prepared by in-situ controlled crystallization of Si-Al-Zr-O amorphous bulk

    Institute of Scientific and Technical Information of China (English)

    LIANG Shu-quan; ZHONG Jie; TAN Xiao-ping; TANG Yan

    2008-01-01

    Zirconia-mullite nano-composite ceramics were fabricated by in-situ controlled crystallization of Si-Al-Zr-O amorphous bulk, which were first treated at 900-1 000 ℃ for nucleation, then treated at higher temperature for crystallization to obtain ultra-fine zirconia-mullite composite ceramics. The effects of treating temperature and ZrO2 addition on mechanical properties and microstructure were analyzed. A unique structure in which there are a lot of near equiaxed t-ZrO2 grains and fine yield-cracks has been developed in the samples with 15% zirconia addition treated at 1 150 ℃. This specific microstructure is much more effective in toughening ceramics matrix and results in the best mechanical properties. The flexural strength and fracture toughness are 520 MPa and 5.13 MPa·m1/2, respectively. Either higher zirconia addition or higher crystallization temperature will produce large size rod-like ZrO2 and mullite grains, which are of negative effect on mechanical properties of this new composite ceramics.

  19. Magnetization Response of the Bulk and Supplementary Magnetic Domain Structure in High-Permeability Steel Laminations Visualized In Situ by Neutron Dark-Field Imaging

    Science.gov (United States)

    Betz, B.; Rauscher, P.; Harti, R. P.; Schäfer, R.; Irastorza-Landa, A.; Van Swygenhoven, H.; Kaestner, A.; Hovind, J.; Pomjakushina, E.; Lehmann, E.; Grünzweig, C.

    2016-08-01

    Industrial transformer cores are composed of stacked high-permeability steel laminations (HPSLs). The performance and degree of efficiency of transformers are directly determined by the magnetic properties of each HPSL. In this article, we show how the neutron dark-field image (DFI) allows for the in situ visualization of the locally resolved response of the bulk and supplementary magnetic domain structures in HPSLs under the influence of externally applied magnetic fields. In particular, we investigate the domain formation and growth along the initial magnetization curve up to the saturated state. For decreasing field, we visualize the recurrence of the hysteretic domain structure down to the remanent state. Additionally, the DFI allows us to derive a correlation between the grain orientation and the corresponding volume and supplementary domain structure. Furthermore, we visualize the influence of the insulation coating, introducing desired tensile stresses on the domain structures. To compare our DFI findings to traditional methods, we perform complementary surface-sensitive magneto-optical Kerr-microscopy investigations.

  20. A simple method for the absolute determination of uranium enrichment by high-resolution {gamma} spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Korob, R.O. [Unidad de Actividad Radioquimica y Quimica de las Radiaciones, Comision Nacional de Energia Atomica, Centro Atomico Ezeiza, Presbitero Juan Gonzalez y Aragon No. 15 Partido de Ezeiza, Provincia de Buenos Aires (Argentina)]. E-mail: korob@cae.cnea.gov.ar; Blasiyh Nuno, G.A. [Unidad de Actividad Gestion de Residuos Radiactivos, Comision Nacional de Energia Atomica, Centro Atomico Ezeiza, Presbitero Juan Gonzalez y Aragon No. 15 Partido de Ezeiza, Provincia de Buenos Aires (Argentina)

    2006-05-15

    A simple method for the determination of uranium enrichment using high-resolution {gamma} spectrometry is presented in this paper. The method relies solely on the {gamma}-ray emission probabilities of {sup 235}U and {sup 234m}Pa, and an iterative procedure for the least squares fit of a polynomial to a set of experimentally determined data. To ensure the reliability of the {sup 234m}Pa {gamma}-ray emission probabilities employed, a new determination of these probabilities was carried out using a combination of {gamma} spectrometry and Cerenkov counting of a purified {sup 234}Th solution. Using these new data, a maximum difference of {approx}5% has been found between the experimental and declared uranium enrichment in a set of solid and liquid samples containing uranium compounds.

  1. Y-Spect: A Multi-Method Gamma Spectrometry Analysis Program

    OpenAIRE

    P.I.Yazid

    2013-01-01

    To accomplish a more accurate, precise and correct interpretation and analysis of spectrum data collecting from a gamma spectrometry counting system, a fully interactive computer code, named Y-Spect, has been developed by using the Delphi 7.0 programming language. The code combines several popular methods for peak search, i.e.: Mariscotti, Phillips-Marlow, Robertson et al., Routti-Prussin, Black, Sterlinski, Savitzky-Golay and Block et al. Any combinations of those methods can be chosen durin...

  2. Gamma spectrometry inspection of TRIGA MARK II fuel using caesium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Karimzadeh, S., E-mail: sam.karimzadeh@ati.ac.a [Vienna University of Technology, Institute of Atomic and Subatomic Physics (ATI), Stadionallee 2, A-1020 Vienna (Austria); Khan, R.; Boeck, H. [Vienna University of Technology, Institute of Atomic and Subatomic Physics (ATI), Stadionallee 2, A-1020 Vienna (Austria)

    2011-01-15

    Research highlights: Cs isotopes are the best choices for the burn up determination of spent fuel. Gamma spectrometer calibration using MCNP5. Cs-ratio can be applied by relative calibration method. - Abstract: Gamma spectrometry is one of the common methods to inspect the spent fuel from research reactors. This method has been applied to in-pool measurements of the Spent Fuel Elements (SPEs) of the TRIGA Mark II research reactor. Due to mixed nature of the reactor core and complicated irradiation history of the fuel elements (FEs), the gamma spectrometry of the FE establishes improvements in the calculation and measurement of the SPE. In order to inspect the TRIGA SPE from dry storage and cooled fuel from the reactor pool, the selected spend fuels are scanned and measured using the fuel-scanning machine. Gamma spectrometry is performed by HPGe detector for spend fuel inspection and determination of the {sup 137}Cs activity and {sup 134}Cs/{sup 137}Cs ratio. In this work, the steps of the detector calibration and the use of the Monte Carlo radiation transport code (MCNP5) have been described. In addition, the fuel-scanning machine and the gamma spectrometer are modelled by MCNP5 to simulate the gamma transport from fuel to detector. It also simulate the gamma spectrometer calibration for the burn up determination of the spend fuel. The results from MCNP5 simulation are applied to spectroscopic measurements and compared with the theoretical predictions of the neutronics code ORIGEN2 in this research work.

  3. Laboratory of High resolution gamma spectrometry; Laboratorio de espectrometria gamma de alta resolucion

    Energy Technology Data Exchange (ETDEWEB)

    Mendez G, A.; Giber F, J.; Rivas C, I.; Reyes A, B

    1992-01-15

    The Department of Nuclear Experimentation of the Nuclear Systems Management requests the collaboration of the Engineering unit for the supervision of the execution of the work of the High resolution Gamma spectrometry and low bottom laboratory, using the hut of the sub critic reactor of the Nuclear Center of Mexico. This laboratory has the purpose of determining the activity of special materials irradiated in nuclear power plants. In this report the architecture development, concepts, materials and diagrams for the realization of this type of work are presented. (Author)

  4. Determination of {sup 7}BE in soil sample by gamma spectrometry for erosion researchs

    Energy Technology Data Exchange (ETDEWEB)

    Esquivel, Alexander D., E-mail: alexander.esquivel@utp.ac.pa [Centro de Investigaciones Hidraulicas e Hidrotecnicas (CIHH/UTP-PA), Universidad Tecnologica de Panama (Panama); Kastner, Geraldo F.; Amaral, Angela M.; Monteiro, Roberto Pellacani G.; Moreira, Rubens M., E-mail: gfk@cdtn.br, E-mail: ama@cdtn.br, E-mail: rpgm@cdtn.br, E-mail: rubens@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-07-01

    Cosmogenic {sup 7}Be is a natural radiotracer produced in the stratosphere and troposphere and reached to the Earth surface via wet and dry fallout and hence its measurement for research of erosion in soils is very significant. The {sup 7}Be radio analyse based on gamma spectrometry technique has been a routine methodology for decades and although is the reference procedure is not free of analytical interference. {sup 7}Be is a β-γ emitting radionuclide (Eγ = 477.59 keV, T½ = 53.12d) and depending on the chemical profile of the soil its determination is susceptible to {sup 228}Ac (E{sub γ} = 478.40 keV, T½ = 6.15h) interference. The aim of this work was to establish an analytical protocol for the {sup 7}Be determination in soil samples from Juatuba-Mg region in different sampling periods of dry and rainy seasons for erosion studies and to establish some methodologies for evaluating and correcting the interference level of {sup 228}Ac in the {sup 7}Be activity measurements by gamma spectrometry. (author)

  5. Preparation of Transparent Bulk TiO2/PMMA Hybrids with Improved Refractive Indices via an in Situ Polymerization Process Using TiO2 Nanoparticles Bearing PMMA Chains Grown by Surface-Initiated Atom Transfer Radical Polymerization.

    Science.gov (United States)

    Maeda, Satoshi; Fujita, Masato; Idota, Naokazu; Matsukawa, Kimihiro; Sugahara, Yoshiyuki

    2016-12-21

    Transparent TiO2/PMMA hybrids with a thickness of 5 mm and improved refractive indices were prepared by in situ polymerization of methyl methacrylate (MMA) in the presence of TiO2 nanoparticles bearing poly(methyl methacrylate) (PMMA) chains grown using surface-initiated atom transfer radical polymerization (SI-ATRP), and the effect of the chain length of modified PMMA on the dispersibility of modified TiO2 nanoparticles in the bulk hybrids was investigated. The surfaces of TiO2 nanoparticles were modified with both m-(chloromethyl)phenylmethanoyloxymethylphosphonic acid bearing a terminal ATRP initiator and isodecyl phosphate with a high affinity for common organic solvents, leading to sufficient dispersibility of the surface-modified particles in toluene. Subsequently, SI-ATRP of MMA was achieved from the modified surfaces of the TiO2 nanoparticles without aggregation of the nanoparticles in toluene. The molecular weights of the PMMA chains cleaved from the modified TiO2 nanoparticles increased with increases in the prolonging of the polymerization period, and these exhibited a narrow distribution, indicating chain growth controlled by SI-ATRP. The nanoparticles bearing PMMA chains were well-dispersed in MMA regardless of the polymerization period. Bulk PMMA hybrids containing modified TiO2 nanoparticles with a thickness of 5 mm were prepared by in situ polymerization of the MMA dispersion. The transparency of the hybrids depended significantly on the chain length of the modified PMMA on the nanoparticles, because the modified PMMA of low molecular weight induced aggregation of the TiO2 nanoparticles during the in situ polymerization process. The refractive indices of the bulk hybrids could be controlled by adjusting the TiO2 content and could be increased up to 1.566 for 6.3 vol % TiO2 content (1.492 for pristine PMMA).

  6. A rapid dissolution procedure to aid initial nuclear forensics investigations of chemically refractory compounds and particles prior to gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Reading, David G., E-mail: d.reading@noc.soton.ac.uk [GAU-Radioanalytical Laboratories, Ocean and Earth Science, University of Southampton, National Oceanography Centre, European Way, Southampton SO14 3ZH (United Kingdom); Croudace, Ian W.; Warwick, Phillip E. [GAU-Radioanalytical Laboratories, Ocean and Earth Science, University of Southampton, National Oceanography Centre, European Way, Southampton SO14 3ZH (United Kingdom); Britton, Richard [AWE plc, Aldermaston, Reading, Berkshire, RG7 4PR (United Kingdom)

    2015-11-05

    A rapid and effective preparative procedure has been evaluated for the accurate determination of low-energy (40–200 keV) gamma-emitting radionuclides ({sup 210}Pb, {sup 234}Th, {sup 226}Ra, {sup 235}U) in uranium ores and uranium ore concentrates (UOCs) using high-resolution gamma ray spectrometry. The measurement of low-energy gamma photons is complicated in heterogeneous samples containing high-density mineral phases and in such situations activity concentrations will be underestimated. This is because attenuation corrections, calculated based on sample mean density, do not properly correct where dense grains are dispersed within a less dense matrix (analogous to a nugget effect). The current method overcomes these problems using a lithium tetraborate fusion that readily dissolves all components including high-density, self-attenuating minerals/compounds. This is the ideal method for dissolving complex, non-volatile components in soils, rocks, mineral concentrates, and other materials where density reduction is required. Lithium borate fusion avoids the need for theoretical efficiency corrections or measurement of matrix matched calibration standards. The resulting homogeneous quenched glass produced can be quickly dissolved in nitric acid producing low-density solutions that can be counted by gamma spectrometry. The effectiveness of the technique is demonstrated using uranium-bearing Certified Reference Materials and provides accurate activity concentration determinations compared to the underestimated activity concentrations derived from direct measurements of a bulk sample. The procedure offers an effective solution for initial nuclear forensic studies where complex refractory minerals or matrices exist. It is also significantly faster, safer and simpler than alternative approaches. - Highlights: • Low energy gamma photons (<200 keV) are attenuated in U-bearing compounds. • Corrections based on bulk density do not yield accurate activity

  7. Two low-level gamma spectrometry systems of the IAEA Safeguards Analytical Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Parus, J.L. [IAEA, SAL, Vienna (Austria); Raab, W. [IAEA, SAL, Vienna (Austria); Donohue, D. [IAEA, SAL, Vienna (Austria); Jansta, V. [IAEA, SAL, Vienna (Austria); Kierzek, J. [IAEA, SAL, Vienna (Austria)

    1997-03-01

    A gamma spectrometry system designed for the measurement of samples with low and medium radioactivity (activity from a few to about 10{sup 4} Bq in the energy range from 25 to 2700 keV) has been installed at the IAEA Safeguards Analytical Laboratory in Seibersdorf. The system consists of 3 low level detectors: (1) n-type coaxial Ge with 42.4% relative efficiency, 1.85 keV FWHM at 1.33 MeV (2) planar Ge with 2000 mm{sup 2} area and 20 mm thickness, 562 eV FWHM at 122 keV (3) NaI(Tl) annulus of 25.4 cm diameter and 25.4 cm height, hole diameter 90 mm. (orig./DG)

  8. Study of different filtering techniques applied to spectra from airborne gamma spectrometry.

    Science.gov (United States)

    Wilhelm, Emilien; Gutierrez, Sébastien; Arbor, Nicolas; Ménard, Stéphanie; Nourreddine, Abdel-Mjid

    2016-11-01

    One of the features of the spectra obtained by airborne gamma spectrometry is the low counting statistics due to a short acquisition time (1 s) and a large source-detector distance (40 m) which leads to large statistical fluctuations. These fluctuations bring large uncertainty in radionuclide identification and determination of their respective activities from the window method recommended by the IAEA, especially for low-level radioactivity. Different types of filter could be used on spectra in order to remove these statistical fluctuations. The present work compares the results obtained with filters in terms of errors over the whole gamma energy range of the filtered spectra with the window method. These results are used to determine which filtering technique is the most suitable in combination with some method for total stripping of the spectrum.

  9. Determination of the self-attenuation correction factor for environmental samples analysis in gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Talita O.; Rocha, Zildete; Knupp, Eliana A.N.; Kastner, Geraldo F.; Oliveira, Arno H. de, E-mail: talitaolsantos@yahoo.com.br, E-mail: rochaz@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Oliveira, Arno H. de, E-mail: arnoheeren@gmail.com [Universidade Federal de Minas Gerais (PCTN/DEN/UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

    2015-07-01

    Gamma spectrometry technique has been used in order to obtain the activity concentrations of natural and artificial radionuclides in environmental samples of different origins, compositions and densities. These samples characteristics may influence the calibration condition by the self-attenuation effect. The sample density has been considered the most important factor. For reliable results, it is necessary to determine self-attenuation correction factor which has been subject of great interest due to its effect on activity concentration. In this context, the aim of this work is to show the calibration process considering the correction by self-attenuation in the evaluation of the concentration of each radionuclide to a gamma HPGEe detector spectrometry system. (author)

  10. The use of difference spectra with a filtered rolling average background in mobile gamma spectrometry measurements

    Energy Technology Data Exchange (ETDEWEB)

    Cresswell, A.J. [Scottish Universities Environmental Research Centre, Rankine Avenue, Scottish Enterprise Technology Park, East Kilbride, Glasgow G75 0QF (United Kingdom)], E-mail: a.cresswell@suerc.gla.ac.uk; Sanderson, D.C.W. [Scottish Universities Environmental Research Centre, Rankine Avenue, Scottish Enterprise Technology Park, East Kilbride, Glasgow G75 0QF (United Kingdom)

    2009-08-21

    The use of difference spectra, with a filtering of a rolling average background, as a variation of the more common rainbow plots to aid in the visual identification of radiation anomalies in mobile gamma spectrometry systems is presented. This method requires minimal assumptions about the radiation environment, and is not computationally intensive. Some case studies are presented to illustrate the method. It is shown that difference spectra produced in this manner can improve signal to background, estimate shielding or mass depth using scattered spectral components, and locate point sources. This approach could be a useful addition to the methods available for locating point sources and mapping dispersed activity in real time. Further possible developments of the procedure utilising more intelligent filters and spatial averaging of the background are identified.

  11. Programmer for automatic gamma spectrometry; Ordonnateur de sequence pour spectrometrie gamma automatique

    Energy Technology Data Exchange (ETDEWEB)

    Romanetti, R. [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

    1968-04-01

    With this apparatus, which is constructed of logical integrated circuits, it is possible both to synchronize an automatic gamma spectrometry assembly and to record the spectra on punched cards. An IBM terminal will make it possible with the help of analysis by the least squares method and by a direct dialogue with an IBM 360 computer to obtain analytical results almost instantaneously. (author) [French] Cet appareil, realise en circuits integres logiques, permet d'une part de synchroniser un ensemble automatique de spectrometrie gamma et d'autre part d'enregistrer les spectres sur cartes perforees. Un terminal IBM permettra, a l'aide d'un programme d'analyse par la methode des moindres carres et par un dialogue direct avec un ordinateur IBM 360, de disposer presque intanstanement des resultats des analyses. (auteur)

  12. Car-borne gamma spectrometry: a virtual exercise in emergency response

    DEFF Research Database (Denmark)

    Dowdall, M.; Smethurst, M.A.; Watson, R.;

    2012-01-01

    a local fire involving radioactive material were added to real car-borne data, participants being asked to produce maps identifying and characterising the regions of contamination. Fourteen individual organisations from seven different countries supplied results which indicated that for strong sources......In recent years car-borne gamma spectrometry has expanded from its role as a geological survey platform to being a useful asset in searching for orphan sources and for surveying in the aftermath of an incident involving the release of radioactive materials. The opportunities for gaining practical...... experience in the field however are limited by cost considerations and practicability. These limitations are exacerbated by the fact that field data can differ significantly from data generated in the laboratory. As a means of exercising existing emergency measuring/surveying capability and introducing car...

  13. First in situ determination of gas transport coefficients (DO2, DAr and DN2) from bulk gas concentration measurements (O2, N2, Ar) in natural sea ice

    DEFF Research Database (Denmark)

    Crabeck, O.; Delille, B.; Rysgaard, Søren

    2014-01-01

    bubbles escaping from the brine to the atmosphere—as the ice gets more permeable during melt—could be responsible for the previously reported high transport coefficients. These results underline that when there is no convective transport within the sea ice, the transport of gas by diffusion through......We report bulk gas concentrations of O2, N2, and Ar, as well as their transport coefficients, in natural landfast subarctic sea ice in southwest Greenland. The observed bulk ice gas composition was 27.5% O2, 71.4% N2, and 1.09% Ar. Most previous studies suggest that convective transport is the main...... driver of gas displacement in sea ice and have neglected diffusion processes. According to our data, brines were stratified within the ice, so that no convective transport could occur within the brine system. There- fore, diffusive transport was the main driver of gas migration. By analyzing the temporal...

  14. Characterization of radioactive orphan sources by gamma spectrometry; Caracterizacion de fuentes huerfanas radiactivas por espectrometria gamma

    Energy Technology Data Exchange (ETDEWEB)

    Cruz W, H., E-mail: wcruz@ipen.gob.pe [Instituto Peruano de Energia Nuclear (PGRR/IPEN), Lima (Peru). Planta de Gestion de Residuos Radiactivos

    2013-07-01

    The sealed radioactive sources are widely applicable in industry. They must have a permanent control and must be registered with the Technical Office of the National Authority (OTAN). However, at times it has identified the presence of abandoned sealed sources unknown to the owner. These sources are called 'orphan sources'. Of course these sources represent a high potential risk because accidents can trigger dire consequences depending on your activity and chemical form in which it presents the radioisotope. This paper describes the process and the actions taken to characterize two orphan radioactive sources from the smelter a Aceros Arequipa. For characterization we used a gamma spectrometry system using a detector NaI(Tl) 3″ x 3″ with a multichannel analyzer Nucleus PCA-II. The radioisotope identified was cesium - 137 ({sup 137}Cs) in both cases. Fortunately, the sources maintained their integrity would otherwise have generated significant pollution considering the chemical form of the radioisotope and easy dispersion. (author)

  15. Cosmic veto gamma-spectrometry for Comprehensive Nuclear-Test-Ban Treaty samples

    Energy Technology Data Exchange (ETDEWEB)

    Burnett, J.L., E-mail: jonathan.burnett@awe.co.uk; Davies, A.V.

    2014-05-21

    The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is supported by a global network of monitoring stations that perform high-resolution gamma-spectrometry on air filter samples for the identification of 85 radionuclides. At the UK CTBT Radionuclide Laboratory (GBL15), a novel cosmic veto gamma-spectrometer has been developed to improve the sensitivity of station measurements, providing a mean background reduction of 80.8% with mean MDA improvements of 45.6%. The CTBT laboratory requirement for a {sup 140}Ba MDA is achievable after 1.5 days counting compared to 5–7 days using conventional systems. The system consists of plastic scintillation plates that detect coincident cosmic-ray interactions within an HPGe gamma-spectrometer using the Canberra Lynx{sup TM} multi-channel analyser. The detector is remotely configurable using a TCP/IP interface and requires no dedicated coincidence electronics. It would be especially useful in preventing false-positives at remote station locations (e.g. Halley, Antarctica) where sample transfer to certified laboratories is logistically difficult. The improved sensitivity has been demonstrated for a CTBT air filter sample collected after the Fukushima incident.

  16. The {sup 124}Sb activity standardization by gamma spectrometry for medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, M.C.M. de, E-mail: marcandida@yahoo.com.b [Laboratorio Nacional de Metrologia das Radiacoes Ionizantes, Instituto de Radioprotecao e Dosimetria, Comissao Nacional de Energia Nuclear (SEMRA/LNMRI/IRD/CNEN), Av. Salvador Allende s/n, Recreio, Rio de Janeiro, RJ, CEP 22780-160 (Brazil); Iwahara, A.; Delgado, J.U.; Poledna, R.; Silva, R.L. da [Laboratorio Nacional de Metrologia das Radiacoes Ionizantes, Instituto de Radioprotecao e Dosimetria, Comissao Nacional de Energia Nuclear (SEMRA/LNMRI/IRD/CNEN), Av. Salvador Allende s/n, Recreio, Rio de Janeiro, RJ, CEP 22780-160 (Brazil)

    2010-07-21

    This work describes a metrological activity determination of {sup 124}Sb, which can be used as radiotracer, applying gamma spectrometry methods with hyper pure germanium detector and efficiency curves. This isotope with good activity and high radionuclidic purity is employed in the form of meglumine antimoniate (Glucantime) or sodium stibogluconate (Pentostam) to treat leishmaniasis. {sup 124}Sb is also applied in animal organ distribution studies to solve some questions in pharmacology. {sup 124}Sb decays by {beta}-emission and it produces several photons (X and gamma rays) with energy varying from 27 to 2700 keV. Efficiency curves to measure point {sup 124}Sb solid sources were obtained from a {sup 166m}Ho standard that is a multi-gamma reference source. These curves depend on radiation energy, sample geometry, photon attenuation, dead time and sample-detector position. Results for activity determination of {sup 124}Sb samples using efficiency curves and a high purity coaxial germanium detector were consistent in different counting geometries. Also uncertainties of about 2% (k=2) were obtained.

  17. Analysis of interferences from full energy peaks in gamma spectrometry of NORM and TENORM samples

    Directory of Open Access Journals (Sweden)

    Živanović Miloš Z.

    2012-01-01

    Full Text Available A considerable number of primordial radioisotopes are present in almost all the samples extracted from the Earth’s crust, such as oil, rock, soil or other materials. Their concentrations are often determined by gamma spectrometry. Although the relative concentrations of isotopes often fluctuate within a narrow range, it is not always the case. Some natural materials (such as naturally occurring radioactive material show unusual activity ratio between 238U and 232Th, while technologically processed materials (technologically enhanced naturally occurring radioactive material might also introduce significant disequilibrium in radioactive chains. Knowing that primordial radioisotopes emit in total more than a thousand gamma and characteristic X-ray photons and that many of them interfere with each other, a question arises whether for some activity ratios commonly used photopeaks become useless for quantitative analysis, due to interferences with other photopeaks. A computer program was developed in order to calculate full energy photon interferences for any chosen photopeak. The calculations are based on the inputs in the form of isotope activities and detector calibration equations and its characteristics are presented in this paper. [Projekat Ministarstva nauke Republike Srbije, br. III43009

  18. Y-Spect: A Multi-Method Gamma Spectrometry Analysis Program

    Directory of Open Access Journals (Sweden)

    P.I. Yazid

    2013-04-01

    Full Text Available To accomplish a more accurate, precise and correct interpretation and analysis of spectrum data collecting from a gamma spectrometry counting system, a fully interactive computer code, named Y-Spect, has been developed by using the Delphi 7.0 programming language. The code combines several popular methods for peak search, i.e.: Mariscotti, Phillips-Marlow, Robertson et al., Routti-Prussin, Black, Sterlinski, Savitzky-Golay and Block et al. Any combinations of those methods can be chosen during a peak searching process, which can be performed in automatic or manual mode. Moving Window Average- and Savitzky-Golay-methods are available for spectrum data smoothing. Peak fitting is done by using a non-linear least square method of Levenberg-Marquardt for either a pure Gaussian peak shape or one with an additional Right/Left Tail function. Other than standard features, such as: peak identification and determination of: continuum, region of interest (ROI, and peak area, etc., Y-Spect has also a special feature which can predict the existence of escape- and/or sum peaks that belong to a certain radioisotope. Aside from displaying the complete spectrum graph, including: singlet or multiplet ROIs and peak identifications, Y-Spect can also display the first- or second-derivative of the spectrum data. Data evaluation is given as: isotope names, peak energy, Net-Count(-Rate, etc. Y-Spect is provided with a complete ENDF/B-VII.0 gamma-ray library file that contains of 16089 gamma energy lines from 1420 different radioisotopes. Other general specifications are: maximum number of: spectrum's channels = 16*1024; ROIs = 2*1024; ROI’s width = 2*1024 channels; Overlapping peaks (multiplet = 20; Identified isotopes = 3*1024, and Isotope library's energy lines = 16*1024

  19. Detection and evaluation of uranium in different minerals by gamma spectrometry and laser induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Sergani, F.M.; Khedr, M.A.; Harith, M.A. [National Inst. of Laser Enhanced Sciences (NILES), Cairo Univ. (Egypt); El Mongy, S.A. [National Center for Nuclear Safety, Atomic Energy Authority, Nasr City, Cairo (Egypt)

    2004-07-01

    Analysis, detection and evaluation of source nuclear materials (e.g. uranium) in different minerals by sensitive techniques are a vital objective for uranium exploration, nuclear materials extraction, processing and verification. In this work, uranium in different geological formations was determined using gamma spectrometry and laser induced breakdown spectroscopy (LIBS). The investigated samples were collected from different regions distributed all over Egypt. The samples were then prepared for non-destructive analysis. A hyper pure germanium detector was used to measure the emitted gamma rays of uranium and its daughters in the samples. The concentrations of uranium in ppm ({mu}g/g) in the investigated samples are given and discussed in this work. The highest uranium concentration (4354.9 ppm) was found in uranophane samples of Gattar rocks. In Laser induced breakdown spectroscopy (LIBS) technique, plasma was formed by irradiating the rock surface with focused Q-switched Nd:Yag laser pulses of 7 ns pulse duration at the fundamental wavelength (1064 nm). Atoms and ions originating from the rock surface are excited and ionized in the laser produced hot plasma ({proportional_to}10 000 K). The plasma emission spectral line is characteristic of the elements present in the plasma and allows identification of the uranium in the uranophane mineral. The strong atomic line at 424.2 nm is used for the qualitative identification of uranium. It can be mentioned that the elevated levels of uranium in some of the investigated uranophane samples are of great economic feasibility to be extracted. (orig.)

  20. The radioactivity measurements in soils and fertilizers using gamma spectrometry technique.

    Science.gov (United States)

    Boukhenfouf, Wassila; Boucenna, Ahmed

    2011-04-01

    Because of their mineral content, soils are naturally radioactive and one of the sources of radioactivity other than those of natural origin is mainly due to the extensive use of fertilizers. The main aim of this paper is to evaluate the fluxes of natural radionuclides in local production of phosphate fertilizers to determine the content of radioactivity in several commercial fertilizers produced in Algeria and to estimate their radiological impact in a cultivated soil even for the long-term exposure due to their application. For these purposes, virgin and fertilized soils were collected from outlying Setif region in Algeria and from phosphate fertilizers used in this area. Gamma spectrometry was exploited to determine activity concentration due to naturally occurring (226)Ra, (232)Th and (40)K in five types of samples (two different sorts of fertilizers, virgin and fertilized soils and well water used for irrigation) taken from Setif's areas. The results show that these radionuclides were present in an average concentration of 134.7 ± 24.1, 131.8 ± 16.7, 11644 ± 550 Bq/kg for the first fertilizer NPK and 190.3 ± 30, 117.2 ± 10.3, 5312 ± 249 Bq/kg for the second fertilizer (NPKs). For the virgin and the fertilized soils, the corresponding values were respectively 47.01 ± 7.3, 33 ± 7, 329.4 ± 19.7 Bq/kg and 53.2 ± 10.6, 50.0 ± 7, 311.4 ± 18.7 Bq/kg. For well water, the values were 1.93 and 0.12 Bq/kg; however the third value was below the Minimum Detectable Activity (MDA). The radium equivalent activity (Raeq) and the representative level index I(γr) for all samples were also calculated. The data were discussed and compared with those given in the literature.

  1. Efficiency transfer using the GEANT4 code of CERN for HPGe gamma spectrometry.

    Science.gov (United States)

    Chagren, S; Ben Tekaya, M; Reguigui, N; Gharbi, F

    2016-01-01

    In this work we apply the GEANT4 code of CERN to calculate the peak efficiency in High Pure Germanium (HPGe) gamma spectrometry using three different procedures. The first is a direct calculation. The second corresponds to the usual case of efficiency transfer between two different configurations at constant emission energy assuming a reference point detection configuration and the third, a new procedure, consists on the transfer of the peak efficiency between two detection configurations emitting the gamma ray in different energies assuming a "virtual" reference point detection configuration. No pre-optimization of the detector geometrical characteristics was performed before the transfer to test the ability of the efficiency transfer to reduce the effect of the ignorance on their real magnitude on the quality of the transferred efficiency. The obtained and measured efficiencies were found in good agreement for the two investigated methods of efficiency transfer. The obtained agreement proves that Monte Carlo method and especially the GEANT4 code constitute an efficient tool to obtain accurate detection efficiency values. The second investigated efficiency transfer procedure is useful to calibrate the HPGe gamma detector for any emission energy value for a voluminous source using one point source detection efficiency emitting in a different energy as a reference efficiency. The calculations preformed in this work were applied to the measurement exercise of the EUROMET428 project. A measurement exercise where an evaluation of the full energy peak efficiencies in the energy range 60-2000 keV for a typical coaxial p-type HpGe detector and several types of source configuration: point sources located at various distances from the detector and a cylindrical box containing three matrices was performed.

  2. Analysis of the 40K levels in soil using gamma spectrometry

    Directory of Open Access Journals (Sweden)

    José Araújo dos Santos Júnior

    2005-10-01

    Full Text Available Potassium-40 was determined in soil in an area with 40,000 m² situated in the western State of Pernambuco, Brazil. For radiometric measurements, the gamma spectrometry method with a high purity germanium (HPGe detector was used. Sampling of 78 soil samples has been performed at intervals of 25 m. The specific activities of 40K were calculated based on the photopeak of 1.46 MeV. Values from 541 to 3,572 Bq kg-1 were obtained (mean of 1,827 Bq kg-1. These values allowed the determination of the elemental concentrations as well as the absorbed dose rates in air, 1 m above the ground. The values varied from 1.7 to 11.5% (mean of 6% and from 23.4 to 154.3 nGy h-1 (mean of 79 nGy h-1, respectively.A radioatividade do 40K foi determinada em solo em uma área de aproximadamente 40.000 m² localizada no Estado de Pernambuco, Brasil. Para as medidas radiométricas foi usado o método de espectrometria gama com detector de germânio de alta pureza (HPGe. A amostragem perfaz um total de setenta e oito amostras de solo coletadas em intervalos de 25 m. As atividades específicas do 40K foram calculadas com base no fotopico gama de 1,46 MeV. Foram obtidos valores que variaram de 541 a 3.572 Bq kg-1 (média aritmética de 1.827 Bq kg-1. Com base nestes cálculos, obteve-se concentrações elementares e doses absorvidas no ar a 1 m, derivadas da contribuição do 40K no solo, onde os valores obtidos variaram respectivamente de 1,7 a 11,5% (média 6% e 23,4 a 154,3 nGy h-1 (média 79 nGy h-1.

  3. Application of in situ measurement for site remediation and final status survey of decommissioning KRR site

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sang Bum; Nam, Jong Soo; Choi, Yong Suk; Seo, Bum Kyoung; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-06-15

    In situ gamma spectrometry has been used to measure environmental radiation, assumptions are usually made about the depth distribution of the radionuclides of interest in the soil. The main limitation of in situ gamma spectrometry lies in determining the depth distribution of radionuclides. The objective of this study is to develop a method for subsurface characterization by in situ measurement. The peak to valley method based on the ratio of counting rate between the photoelectric peak and Compton region was applied to identify the depth distribution. The peak to valley method could be applied to establish the relation between the spectrally derived coefficients (Q) with relaxation mass per unit area (β) for various depth distribution in soil. The in situ measurement results were verified by MCNP simulation and calculated correlation equation. In order to compare the depth distributions and contamination levels in decommissioning KRR site, in situ measurement and sampling results were compared. The in situ measurement results and MCNP simulation results show a good correlation for laboratory measurement. The simulation relationship between Q and source burial for the source layers have exponential relationship for a variety depth distributions. We applied the peak to valley method to contaminated decommissioning KRR site to determine a depth distribution and initial activity without sampling. The observed results has a good correlation, relative error between in situ measurement with sampling result is around 7% for depth distribution and 4% for initial activity. In this study, the vertical activity distribution and initial activity of {sup 137}Cs could be identifying directly through in situ measurement. Therefore, the peak to valley method demonstrated good potential for assessment of the residual radioactivity for site remediation in decommissioning and contaminated site.

  4. Integrated evaluation of the geology, aero gamma spectrometry and aero magnetometry of the Sul-Riograndense Shield, southernmost Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, Leo A.; Savian, Jairo F., E-mail: leo.hartmann@ufrgs.br [Universidade Federal do Rio Grande do Sul (UFRS), Porto Alegre, RS (Brazil). Instituto de Geociencias; Lopes, William R. [Servico Geologico do Brasil (CPRM), Porto Alegre, RS (Brazil). Gerencia de Geologia e Mineracao

    2016-03-15

    An integrated evaluation of geology, aero gamma spectrometry and aero magnetometry of the Sul-Riograndense Shield is permitted by the advanced stage of understanding of the geology and geochronology of the southern Brazilian Shield and a 2010 airborne geophysical survey. Gamma rays are registered from the rocks near the surface and thus describe the distribution of major units in the shield, such as the Pelotas batholith, the juvenile São Gabriel terrane, the granulite-amphibolite facies Taquarembo terrane and the numerous granite intrusions in the foreland. Major structures are also observed, e.g., the Dorsal de Cangucu shear. Magnetic signals register near surface crustal compositions (analytic signal) and total crust composition (total magnetic signal), so their variation as measured indicates either shallow or whole crustal structures. The Cacapava shear is outstanding on the images as is the magnetic low along the N-S central portion of the shield. These integrated observations lead to the deepening of the understanding of the largest and even detailed structures of the Sul-Riograndense Shield, some to be correlated to field geology in future studies. Most significant is the presence of different provinces and their limits depending on the method used for data acquisition - geology, aero gamma spectrometry or aero magnetometry. (author)

  5. Dating of sediments from four Swiss prealpine lakes with (210)Pb determined by gamma-spectrometry: progress and problems.

    Science.gov (United States)

    Putyrskaya, V; Klemt, E; Röllin, S; Astner, M; Sahli, H

    2015-07-01

    In this paper the most important problems in dating lake sediments with unsupported (210)Pb are summarized and the progress in gamma-spectrometry of the unsupported (210)Pb is discussed. The main topics of these studies concern sediment samples preparation for gamma-spectrometry, measurement techniques and data analysis, as well as understanding of accumulation and sedimentation processes in lakes. The vertical distributions of artificial ((137)Cs, (241)Am, (239)Pu) and natural radionuclides ((40)K, (210,214)Pb, (214)Bi) as well as stable trace elements (Fe, Mn, Pb) in sediment cores from four Swiss lakes were used as examples for the interpretation, inter-comparison and validation of depth-age relations established by three (210)Pb-based models (CF-CSR, CRS and SIT). The identification of turbidite layers and the influence of the turbidity flows on the accuracy of sediment dating is demonstrated. Time-dependent mass sedimentation rates in lakes Brienz, Thun, Biel and Lucerne are discussed and compared with published data.

  6. Methodology for determination of activity of radionuclides by gamma spectrometry; Metodologia para determinacao da atividade de radionuclideos por sistema de espectrometria gama

    Energy Technology Data Exchange (ETDEWEB)

    Fragoso, Maria da Conceicao de Farias; Oliveira, Victor Rogerio S. de; Oliveira, Mercia L.; Lima, Fernando Roberto de Andrade, E-mail: mariacc05@gmail.com [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-NE), Recife, PE (Brazil)

    2014-07-01

    Due to the growth in the number of procedures that make use of the positron emission tomography (PET), there is a need for standard solutions for the calibration of the systems used for the measurement of the PET radiopharmaceutical (activimeter) in radiopharmacies and in nuclear medicine services. Among the existing alternatives for the standardization of radioactive sources, the method known as gamma spectrometry is widely used for short-lived radionuclides. The purpose of this study was to implement the methodology for standardization of the {sup 18}F solutions by gamma spectrometry at the Regional Center for Nuclear Sciences of the Northeast (CRCN-NE/CNEN-NE), Brazil. (author)

  7. Determination of {sup 238}U and {sup 232}Th in geological samples by alpha and gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Farias, Emerson E.G. de; Hazin, Clovis A., E-mail: chazin@cnen.gov.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Honorato, Eliane V.; Franca, Elvis J. De, E-mail: valentim@cnen.gov.br, E-mail: ejfranca@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2011-07-01

    Alpha and gamma spectrometry are analytical techniques of great importance for the determination of natural radionuclides, especially for radioisotopes of the {sup 238}U and {sup 232}Th series. Due to the presence of completely different chemical elements in these series, with different gamma-ray abundances and decay branches, it is quite relevant to define consistent analytical approaches to be adopted in an environmental analysis routine basis. For the establishment of such protocol for the radiometric analysis of geological samples routinely analyzed in the Environmental Monitoring Division of the Northeastern Regional Center for Nuclear Sciences (CRCN-NE), reference materials of different geologic matrices prepared by the International Atomic Energy Agency - IAEA were analyzed through high resolution gamma-ray spectrometry by means of a Hyper Pure Germanium (HPGe) detector and high resolution alpha spectrometry using a surface barrier detector. Test portions of 2.5 g (for alpha analysis) and 50.0 g (for gamma analysis) of the reference materials IAEA-312 (soil), IAEA-314 (stream sediment), IAEA-375 (soil), and IAEA-135 (sea sediment) were analyzed. The concordance between the obtained values and the reference values for the specific activities of {sup 238}U and {sup 232}Th determined in the certified materials was considered quite satisfactory for both analytical techniques, since the relative errors were lower than 20 %, except for the results of gamma spectrometry using the line 93 keV, in which interference from the 93,35 keV gamma line of {sup 228}Ac (from the {sup 232}Th series) was detected. The results indicated a good degree of comparability for the radiometric analysis of geological samples. (author)

  8. A review of the nationwide proficiency test on natural radioactivity measurements by gamma spectrometry.

    Science.gov (United States)

    Şahin, N K; Yeltepe, E; Yücel, Ü

    2016-03-01

    This study is the review of the first proficiency test on radioactivity measurement organized in Turkey by Sarayköy Nuclear Research and Training Center (SANAEM) of Turkish Atomic Energy Authority (TAEK) in 2013. The objective of the test was to determine (226)Ra, (232)Th and (40)K activity concentrations in natural soil samples using gamma-ray spectrometry. The bulk material consisting of uranium- and thorium-rich soil and sand was milled, mixed thoroughly and sieved. Homogeneity of the final mix was tested with 6 randomly taken samples. 16 proficiency test samples were distributed to 16 participating laboratories. 12 laboratories reported results. The results were evaluated on the accuracy and precision criteria adopted by the IAEA Proficiency Testing Group. The percentage of acceptable scores was 49%. Some recommendations have been provided to the laboratories to improve the quality of their results. It is planned to extend these proficiency tests periodically for various radionuclides in various matrices.

  9. Scientific rationale of Saturn's in situ exploration

    CERN Document Server

    Mousis, O; Lebreton, J -P; Wurz, P; Cavalié, T; Coustenis, A; Courtin, R; Gautier, D; Helled, R; Irwin, P G J; Morse, A D; Nettelmann, N; Marty, B; Rousselot, P; Venot, O; Atkinson, D H; Waite, J H; Reh, K R; Simon-Miller, A; Atreya, S; André, N; Blanc, M; Daglis, I A; Fischer, G; Geppert, W D; Guillot, T; Hedman, M M; Hueso, R; Lellouch, E; Lunine, J I; Murray, C D; O'Donoghue, J; Rengel, M; Sanchez-Lavega, A; Schmider, F -X; Spiga, A; Spilker, T; Petit, J -M; Tiscareno, M S; Ali-Dib, M; Altwegg, K; Bouquet, A; Briois, C; Fouchet, T; Guerlet, S; Kostiuk, T; Lebleu, D; Moreno, R; Orton, G S; Poncy, J

    2014-01-01

    Remote sensing observations meet some limitations when used to study the bulk atmospheric composition of the giant planets of our solar system. A remarkable example of the superiority of in situ probe measurements is illustrated by the exploration of Jupiter, where key measurements such as the determination of the noble gases abundances and the precise measurement of the helium mixing ratio have only been made available through in situ measurements by the Galileo probe. This paper describes the main scientific goals to be addressed by the future in situ exploration of Saturn placing the Galileo probe exploration of Jupiter in a broader context and before the future probe exploration of the more remote ice giants. In situ exploration of Saturn's atmosphere addresses two broad themes that are discussed throughout this paper: first, the formation history of our solar system and second, the processes at play in planetary atmospheres. In this context, we detail the reasons why measurements of Saturn's bulk element...

  10. Precise determination of HPGe detector efficiency for gamma spectrometry measurements of environmental samples with variable geometry and density

    Directory of Open Access Journals (Sweden)

    Barrera Manuel

    2017-03-01

    Full Text Available A methodology to determine the full energy peak efficiency (FEPE for precise gamma spectrometry measurements of environmental samples with high-purity germanium (HPGe detector, valid when this efficiency depends on the energy of the radiation E, the height of the cylindrical sample H, and its density ρ, is introduced. The methodology consists of an initial calibration as a function of E and H and the application of a self-attenuation factor, depending on the density of the sample ρ, in order to correct for the different attenuation of the generic sample in relation to the measured standard. The obtained efficiency can be used in the whole range of interest studied, E = 120–2000 keV, H = 1–5 cm, and ρ = 0.8–1.7 g/cm3, being its uncertainty below 5%. The efficiency has been checked by the measurement of standards, resulting in a good agreement between experimental and expected activities. The described methodology can be extended to similar situations when samples show geometric and compaction differences.

  11. Measurement of short-lived radon progenies by simultaneous alpha gamma-spectrometry at the German radon reference chamber

    CERN Document Server

    Paul, A; Honig, A; Sulima, T; Buchholz, A; Keyser, U

    1999-01-01

    In the German radon reference chamber, the short-lived radon progenies are separated by a sample tube according to the attached or unattached fraction, while their activity concentration is afterwards measured by simultaneous alpha- and gamma-spectrometry. The results are expressed by the equilibrium factor F and the unattached fraction f sub p (International Commission on Radiological Protection, ICRP Publication 50, Ann. ICRP 17 (1987) 1). Both F and f sub p , can be therefore studied with respect to the full set of environmental parameters, e.g. temperature, humidity, air pressure and aerosol concentration (Honig et al., Nucl. Instr. and Meth. A 416 (1998) 525). Up to now, well-defined and stable equilibrium factors in the interval from 0.1 to 1.0 have been established. In correlation with this, the unattached fraction can be varied from 0.01 to 0.9. The sample and measuring technique for the short-lived radon progenies described in this work is the basis for fundamental studies with regard to the equilibr...

  12. Study on the natural radioactivity from the region of Presidente Figueiredo (AM), Brazil, using gamma spectrometry; Estudo da radioatividade natural da regiao de Presidente Figueiredo (AM) utilizando espectrometria gama

    Energy Technology Data Exchange (ETDEWEB)

    Da Silva, Jose Ribamar Silveira

    1999-07-01

    A gamma spectrometry profile was carried out along BR174 highway, that crosses some lithostratigraphic units of the North portion of the Sedimentary Basin of Amazon. Measurements in situ were realized in 116 points, 1 km apart, using a GAD-6 gamma-spectrometer and samples of rocks and soils were collected in geologically representative points, for gamma measurements using a shielded detector of NaI(Tl) available in the Nuclear Geophysics Laboratory of IAG/USP. The criterion used for evaluating the reliability degree of the concentration values of eU (ppm), eTh (ppm) and %K was to establish mathematically detection limits, for all measurement points. Every these points had been located using GPS with accuracy of 50 m to become possible a future detailed study. The purpose of matching portable gamma spectrometer and laboratory determinations was to compare the 2 techniques, using the criterion of detectability limits, and to verify the influence of {sup 222} Rn atmospheric radioactive gas in field measurements. In the case of portable detector, it allows fast measurements and the sensor 'sees' a big volume of material (rock, soil...), that makes it more representative. In some situations where atmospheric phenomena of thermal inversion occurs, measurement can be affected by the {sup 222} Rn cosmic background. Presence of radon daughter elements, associated with aerosols, in this tropical environment (high values of temperature and humidity), where the speed of the wind that could exhaust this gas is practically zero. It is observed that the values of concentration in the some points, got with these 2 techniques, have the same trend, and the stretches where peaks of concentration of K also occur and U and Th are associated with the presence of granite out corps, great boulders, and clay soils from weathering of these rocks. (author)

  13. A Case Study Correlating Innovative Gamma Ray Scanning Detection Systems Data to Surface Soil Gamma Spectrometry Results - 13580

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Shannon; Rodriguez, Rene; Billock, Paul [HydroGeoLogic, Inc., 11107 Sunset Hills Road, Suite 400, Reston, VA 20190 (United States); Lit, Peter [Nomad Science Group, 7738 Nautilus Shell Street, Las Vegas, NV 89139 (United States)

    2013-07-01

    HydroGeoLogic (HGL), Inc. completed a United States Environmental Protection Agency (USEPA) study to characterize radiological contamination at a site near Canoga Park, California. The characterized area contained 470 acres including the site of a prototype commercial nuclear reactor and other nuclear design, testing, and support operations from the 1950's until 1988 [1]. The site history included radiological releases during operation followed by D and D activities. The characterization was conducted under an accelerated schedule and the results will support the project remediation. The project has a rigorous cleanup to background agenda and does not allow for comparison to risk-based guidelines. To target soil sample locations, multiple lines of evidence were evaluated including a gamma radiation survey, geophysical surveys, historical site assessment, aerial photographs, and former worker interviews. Due to the time since production and decay, the primary gamma emitting radionuclide remaining is cesium-137 (Cs-137). The gamma ray survey covered diverse, rugged terrain using custom designed sodium iodide thallium-activated (NaI(Tl)) scintillation detection systems. The survey goals included attaining 100% ground surface coverage and detecting gamma radiation as sensitively as possible. The effectiveness of innovative gamma ray detection systems was tested by correlating field Cs-137 static count ratios to Cs-137 laboratory gamma spectrometry results. As a case study, the area encompassing the former location of the first nuclear power station in the U. S. was scanned, and second by second global positioning system (GPS)-linked gamma spectral data were evaluated by examining total count rate and nuclide-specific regions of interest. To compensate for Compton scattering from higher energy naturally occurring radionuclides (U-238, Th-232 and their progeny, and K-40), count rate ratios of anthropogenic nuclide-specific regions of interest to the total count rate

  14. 原位本体聚合制备聚甲基丙烯酸甲酯/量子点纳米复合材料及其性能%Synthesis and characterization of PMMA/CdSe nanocomposites parpared by in situ bulk polymerization

    Institute of Scientific and Technical Information of China (English)

    张旺喜; 张倩; 龚兴厚; 蒋久信; 王小涛; 刘嘉宁

    2012-01-01

    For preparing semiconductor nanocrystal with steady luminescence and good processability, poly methy lmecrylate(PMMA)/CdSe -ZnS nanocomposites were prepared by in situ bulk polymerization. Fourier transform infrared spectrometer,transmission electron microscopy,thermal gravimetric analysis and fluorospectro photometer were used to characterize the nanocomposites. The results indicate that the transparent PMMA/CdSe -ZnS nanocomposites can be fabricated by in situ bulk polymerization,quantum dots with steady luminescence are uniform distribution in polymer, the emission wavelength has a slight red shift, additionally, the thermal property of PMMA is improved by adding CdSe -ZnS QDs.%为了得到易于加工成型、且具有稳定发光性能的半导体纳米晶体材料,采用原位本体聚合的方法制备了聚甲基丙烯酸甲酯/硒化镉-硫化锌核壳量子点(PMMA/CdSe-ZnS)纳米复合材料,并对其进行了傅立叶变换红外光谱仪(FT-IR)、透射电镜(TEM)、热重分析(TGA)和光致发光光谱的测试.研究结果表明:经原位本体聚合能成功制备透明PMMA/CdSe-ZnS纳米复合材料,硒化镉-硫化锌核壳量子点(CdSe-ZnS)在聚甲基丙烯酸甲酯(PMMA)基体中分散性好,粒径均一,且能长时间稳定发光,发光波长出现了少量的红移.另外,量子点的加入对聚合物的热性能有一定的改善.

  15. Low-energy X-ray and gamma spectrometry using silicon photodiodes; Espectrometria de raios X e gama de baixa energia utilizando fotodiodos de silicio

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Iran Jose Oliveira da

    2000-08-01

    The use of semiconductor detectors for radiation detection has increased in recent years due to advantages they present in comparison to other types of detectors. As the working principle of commercially available photodiodes is similar to the semiconductor detector, this study was carried out to evaluate the use of Si photodiodes for low energy x-ray and gamma spectrometry. The photodiodes investigated were SFH-205, SFH-206, BPW-34 and XRA-50 which have the following characteristics: active area of 0,07 cm{sup 2} and 0,25 cm{sup 2}, thickness of the depletion ranging from 100 to 200 {mu}m and junction capacitance of 72 pF. The photodiode was polarized with a reverse bias and connected to a charge sensitive pre-amplifier, followed by a amplifier and multichannel pulse analyzer. Standard radiation source used in this experiment were {sup 241} Am, {sup 109} Cd, {sup 57} Co and {sup 133} Ba. The X-ray fluorescence of lead and silver were also measured through K- and L-lines. All the measurements were made with the photodiodes at room temperature.The results show that the responses of the photodiodes very linear by the x-ray energy and that the energy resolution in FWHM varied between 1.9 keV and 4.4 keV for peaks corresponding to 11.9 keV to 59 keV. The BPW-34 showed the best energy resolution and the lower dark current. The full-energy peak efficiency was also determined and it was observed that the peak efficiency decreases rapidly above 50 keV. The resolution and efficiency are similar to the values obtained with other semiconductor detectors, evidencing that the photodiodes used in that study can be used as a good performance detector for low energy X-ray and gamma spectrometry. (author)

  16. In situ groundwater bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Hazen, Terry C.

    2009-02-01

    In situ groundwater bioremediation of hydrocarbons has been used for more than 40 years. Most strategies involve biostimulation; however, recently bioaugmentation have been used for dehalorespiration. Aquifer and contaminant profiles are critical to determining the feasibility and strategy for in situ groundwater bioremediation. Hydraulic conductivity and redox conditions, including concentrations of terminal electron acceptors are critical to determine the feasibility and strategy for potential bioremediation applications. Conceptual models followed by characterization and subsequent numerical models are critical for efficient and cost effective bioremediation. Critical research needs in this area include better modeling and integration of remediation strategies with natural attenuation.

  17. A method for determining the analytical form of a radionuclide depth distribution using multiple gamma spectrometry measurements

    Energy Technology Data Exchange (ETDEWEB)

    Dewey, Steven Clifford, E-mail: sdewey001@gmail.com [United States Air Force School of Aerospace Medicine, Occupational Environmental Health Division, Health Physics Branch, Radiation Analysis Laboratories, 2350 Gillingham Drive, Brooks City-Base, TX 78235 (United States); Whetstone, Zachary David, E-mail: zacwhets@umich.edu [Radiological Health Engineering Laboratory, Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, 1906 Cooley Building, Ann Arbor, MI 48109-2104 (United States); Kearfott, Kimberlee Jane, E-mail: kearfott@umich.edu [Radiological Health Engineering Laboratory, Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, 1906 Cooley Building, Ann Arbor, MI 48109-2104 (United States)

    2011-06-15

    When characterizing environmental radioactivity, whether in the soil or within concrete building structures undergoing remediation or decommissioning, it is highly desirable to know the radionuclide depth distribution. This is typically modeled using continuous analytical expressions, whose forms are believed to best represent the true source distributions. In situ gamma ray spectroscopic measurements are combined with these models to fully describe the source. Currently, the choice of analytical expressions is based upon prior experimental core sampling results at similar locations, any known site history, or radionuclide transport models. This paper presents a method, employing multiple in situ measurements at a single site, for determining the analytical form that best represents the true depth distribution present. The measurements can be made using a variety of geometries, each of which has a different sensitivity variation with source spatial distribution. Using non-linear least squares numerical optimization methods, the results can be fit to a collection of analytical models and the parameters of each model determined. The analytical expression that results in the fit with the lowest residual is selected as the most accurate representation. A cursory examination is made of the effects of measurement errors on the method. - Highlights: > A new method for determining radionuclide distribution as a function of depth is presented. > Multiple measurements are used, with enough measurements to determine the unknowns in analytical functions that might describe the distribution. > The measurements must be as independent as possible, which is achieved through special collimation of the detector. > Although the effects of measurements errors may be significant on the results, an improvement over other methods is anticipated.

  18. In Situ Mass Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The In Situ Mass Spectrometer projects focuses on a specific subsystem to leverage advanced research for laser-based in situ mass spectrometer development...

  19. Evaluating airborne and ground based gamma spectrometry methods for detecting particulate radioactivity in the environment: A case study of Irish Sea beaches

    Energy Technology Data Exchange (ETDEWEB)

    Cresswell, A.J., E-mail: Alan.Cresswell@glasgow.ac.uk; Sanderson, D.C.W.

    2012-10-15

    In several places, programmes are in place to locate and recover radioactive particles that have the potential to cause detrimental health effects in any member of the public who may encounter them. A model has been developed to evaluate the use of mobile gamma spectrometry systems within such programmes, with particular emphasis on large volume (16 l) NaI(Tl) detectors mounted in low flying helicopters. This model uses a validated Monte Carlo code with assessment of local geochemistry and natural and anthropogenic background radiation concentrations and distributions. The results of the model, applied to the example of particles recovered from beaches in the vicinity of Sellafield, clearly show the ability of rapid airborne surveys conducted at 75 m ground clearance and 120 kph speeds to demonstrate the absence of sources greater than 5 MBq {sup 137}Cs within large areas (10-20 km{sup 2} h{sup -1}), and identify areas requiring further ground based investigation. Lowering ground clearance for airborne surveys to 15 m whilst maintaining speeds covering 1-2 km{sup 2} h{sup -1} can detect buried {sup 137}Cs sources of 0.5 MBq or greater activity. A survey design to detect 100 kBq {sup 137}Cs sources at 10 cm depth has also been defined, requiring surveys at < 15 m ground clearance and < 2 m s{sup -1} ground speed. The response of airborne systems to the Sellafield particles recovered to date has also been simulated, and the proportion of the existing radiocaesium background in the vicinity of the nuclear site has been established. Finally the rates of area coverage and sensitivities of both airborne and ground based approaches are compared, demonstrating the ability of airborne systems to increase the rate of particle recovery in a cost effective manner. The potential for equipment and methodological developments to improve performance are discussed. -- Highlights: Black-Right-Pointing-Pointer Validated Monte Carlo simulations used to model mobile gamma spectrometry

  20. Development and calibration automatic equipment's measuring in real time of the environmental radioactivity by gamma spectrometry; Desarrollo y calibracion de equipos automaticos de medida en tiempo real de la radiactividad ambiental mediante espectrometria gamma

    Energy Technology Data Exchange (ETDEWEB)

    Casanovas, R.; Morant, J. J.; Salvado, M.

    2013-07-01

    In this paper, we describe the general aspects of the implementation of gamma spectrometry in water, as well as the development of two measuring devices based on this technique: aerosol monitor (RARM-F) and a monitor direct measurement (RARMD2) , both patent applications. Furthermore, they described in detail the aspects of calibration of equipment, which has been made by combining experimental measurements with Monte Carlo simulations. (Author)

  1. Measurement of radon concentration in water by means of {alpha}, {gamma} spectrometry. Radon concentration in ground and spring water in Hiroshima Prefecture

    Energy Technology Data Exchange (ETDEWEB)

    Shizuma, Kiyoshi [Hiroshima Univ. (Japan)

    1997-02-01

    Radon ({sup 222}Rn, T{sub 1/2}=3.8235{+-}0.0003d) is {alpha}-ray releasing nuclide, so that it can not be detected by {gamma}-ray measurement. But, the daughter nuclides {sup 214}Pb (T{sub 1/2}=26.8 min) and {sup 214}Bi (T{sub 1/2}=19.9 min) release {gamma}-ray, accordingly they are measured by Ge detector. Their radioactive equilibrium is kept in the closed vessel, because their half-lives are shorter than that of radon. We developed a measurement method of radon concentration by means of {gamma}-spectrometry. We applied this method to catch radon in the atmosphere by active carbon. The same principle can be applied to radon in water. Radon concentrations in the ground water were measured in 22 points in the Higashi-Hiroshima city and 82 points in the Hiroshima prefecture. The efficiencies of {gamma}-ray were determined. The radon concentration showed between 11 and 459 Bq/l and the average was 123 Bq/l. The high concentration of radon was distributed in the spring of granitic layer and higher concentration of radon were observed in the ground water of fault. (S.Y.)

  2. Analysis of the gamma spectrometry {sup 210}Pb radioisotope in river bottom sediments of the hydrographic sub-basins around the UTM-Caldas

    Energy Technology Data Exchange (ETDEWEB)

    Dutra, Pedro H.; Carvalho Filho, Carlos A.; Moreira, Rubens M.; Menezes, Maria Angela B.C.; Oliveira, Aline F.G. de, E-mail: pedrohenrique.dutra@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Silva, Nivaldo C., E-mail: ncsilva@cnen.gov.br [Comissao Nacional de Energia Nuclear (LAPOC/CNEN-MG), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas; Viana, Valquiria F.L., E-mail: valquiria.flviana@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Instituto de Ciencias Biologicas

    2015-07-01

    The uranium mine of Caldas, currently named Ore Treatment Unit (UTM-Caldas), is sited at the Pocos de Caldas Plateau (Minas Gerais State) and was the first uranium mineral-industrial complex in Brazil. It has been installed since 1982 and now it is under decommissioning process. Taking into account the potential sources of contamination and the assessment of the impact of the mine, based on the presence of radionuclides from the radioactive decay series of natural {sup 238}U, the aim of the article is to present the distribution of {sup 210}Pb in the stream bottom sediments of the study area that consists of the Taquari watershed, sub-divided by its three major sub-basins: Consulta stream, Soberbo stream and Taquari river. The radionuclide activity concentrations were measured in sediment samples that were collected in twelve collecting points, during four sampling campaigns, carried out in the dry and rainy seasons of 2010 and 2011. The results of the {sup 210}Pb concentration activity were obtained by gamma spectrometry performed in both high and low energy CANBERRA detectors. The results point out that the UTM-Caldas is influencing on the bottom sediment distribution of {sup 210}Pb activity in its neighborhood. However, a more detailed study should be done in order to identify if there is another source of {sup 210}Pb in the study area, such as a geogenic anomaly, that may contributing to the local increment of {sup 210}Pb activity. (author)

  3. Determination of (241)Pu by the method of disturbed radioactive equilibrium using 2πα-counting and precision gamma-spectrometry.

    Science.gov (United States)

    Alekseev, I; Kuzmina, T

    2016-04-01

    A simple technique is proposed for the determination of the content of (241)Pu, which is based on disturbance of radioactive equilibrium in the genetically related (237)U←(241)Pu→(241)Am decay chain of radionuclides, with the subsequent use of 2πα-counting and precision gamma-spectroscopy for monitoring the process of restoration of that equilibrium. It has been shown that the data on dynamics of accumulation of the daughter (241)Am, which were obtained from the results of measurements of α- and γ-spectra of the samples, correspond to the estimates calculated for the chain of two genetically related radionuclides, the differences in the estimates of (241)Pu radioactivity not exceeding 2%. Combining the different methods of registration (2πα-counting, semiconductor alpha- and gamma-spectrometry) enables the proposed method to be efficiently applied both for calibration of (241)Pu-sources (from several hundreds of kBq and higher) and for radioisotopic analysis of plutonium mixtures. In doing so, there is a deep purification of (241)Pu from its daughter decay products required due to unavailability of commercial detectors that could make it possible, based only on analysis of alpha-spectra, to conduct quantitative analysis of the content of (238)Pu and (241)Am.

  4. In-Situ Simulation

    DEFF Research Database (Denmark)

    Bjerregaard, Anders Thais; Slot, Susanne; Paltved, Charlotte

    2015-01-01

    . In situ simulation in continuing medical education for the health care professions: a systematic review. J Contin Educ Health Prof 2012;32:243-254 (2) Sexton JB, Helmreich RL, Neilands TB, Rowan K, Vella K. The Safety Attitudes Questionnaire: Psychometric properties, benchmarking data, and emerging...... research. BMC Health service research 2006;6:1472-6963 (3) Cooper S. et al. Team Emergency Assessment Measure (TEAM). Resuscitation. 2010;81:446-452 (4) Flanagan JC. The critical incident technique. Psychological bulletin 1954;51:327-359 (5) Haig KM, Sutton RC, Whittington J. SBAR: A shared Mental Model...... emergencies. It contains 12 questions, which are rated using a five-point scale, and covers four categories; leadership, teamwork and task management, and an overall score on team performance. Results: 16 simulations were conducted with 16 different teams of 10 doctors and 32 nurses. First, this study took...

  5. γ谱法监测环境中放射性气溶胶%Radioactive Aerosol in the Monitoring Environment by Gamma Spectrometry

    Institute of Scientific and Technical Information of China (English)

    张枫; 屈国普; 陈祥磊; 龚玉巍

    2015-01-01

    In order to monitor the radioactive aerosols in the environment more effectively , the method of meas-uring the radioactive aerosol by using the gamma spectrometry is discussed .To filter environment aerosol parti-cles on the membrane filter , a gamma spectrometer with a scintillation detector to measure the gamma energy spectra of gamma radioactive aerosol particles is used .The type and activity of radionuclides in environmental samples were obtained by the analysis of the gamma energy spectra .Experimental results show that this method can effectively monitor the radioactive aerosol and has a good ability to identify radionuclides in environmental samples .%为了更有效地对环境中放射性气溶胶进行监测,探讨了γ谱法测量放射性气溶胶的监测方法。该方法将环境中气溶胶颗粒过滤到滤膜之上,利用配以闪烁体探测器的γ谱仪测量过滤膜上的γ放射性气溶胶颗粒的γ能谱,通过γ能谱解析来获得环境样品中放射性核素类型及其活度。实验结果表明:该方法可有效地监测放射性气溶胶,对环境样品中放射性核素具有一定的鉴别能力。

  6. Methodology for measuring surfaces using in situ gamma spectrometry in nuclear and radiological emergencies; Metodologia de medida de superficies mediante espectrometria gamma in sit en emergencias radiologicas y nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Yague, L.; Navarro, N.; Perez, C.; Perez-Cejuela, P.; Vico, A.; Maquez, J. L.; Alvarez, A.

    2013-07-01

    CIEMAT has an environmental mobile unit for measurements of ambient dose rate and activity concentration in air. In addition, recently it included the ability to surface concentration measurement. This measure is particularly useful for making decisions about emergency decontaminate surfaces according to the criteria of the DBRR. (Author)

  7. Determination and quantification of impurities found in samples of {sup 124}I using gamma spectrometry; Determinacao e quantificacao de impurezas encontradas em amostra de {sup 124}I usando a espectrometria gama

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ronaldo Lins da; Delgado, Jose Ubiratan; Araujo, Miriam Taina Ferreira de; Laranjeira, Adilson da Silva; Poledna, Roberto; Veras, Eduardo de; Almeida, Maria Candida M. [Instituto de Radioprotecao e Dosimetria, (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Braghirolli, Ana Maria S. [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    {sup 124}I, positron emitter is produced in the IEN/CNEN-RJ and used in diagnosis image of tumors. In this radioisotope production process impurities appear and health agency requires that the level of these characteristics is quantified. These radionuclides emit gamma and X-radiation, allowing the identification and quantitation by gamma spectrometry. With the use of HPGE detector, coupled with the efficiency curve, was identified {sup 125}I and {sup 126}I. The impurity levels measured in the sample were in the range of 0.5% to 90%, respectively, indicating the feasibility of the method for controlling the quality of the radiopharmaceutical.

  8. Analysis of 226Ra, 232Th 40К and 137Cs in samples of soil from some areas of Republic of Macedonia by using gamma spectrometry

    Directory of Open Access Journals (Sweden)

    Todorovik Aleksandra

    2012-01-01

    Full Text Available Taking into consideration the importance of the distribution and transfer of radio nuclides in soil, an attempt was made in this work to determine the concentration of 226Ra, 232Th 40К and 137Cs in the same. The concentrations of activity in the gamma-absorbed dose rates of the terrestrial naturally occurring radio nuclides, as follows, 226Ra, 232Th and 40K were determined in samples of soil collected from some parts of Republic of Macedonia, i.e. from three major cities in the Republic of Macedonia. The samples are taken by means of a special dosage dispenser which enables sampling of samples at a depth of 0-5 cm, 5-10cm and 10-15cm, thus disabling the sampling above these layers of soil. An identification of radio nuclides and assessment of their activity has been performed by applying gamma spectrometry. The time of counting for each sample was 65000 s. in order to obtain statistically small mistake. The spectrums were analyzed by a commercially available software GENIE-2000 received from Canberra, Austria. The activity of soil had wide range of values: 20.3 to 82.9 Bq kg-1for 226Ra, 16.1 to 82.5 Bq kg-1 for 232Th, 325 to 799.0 Bq kg-1for 40К and 9.1 to 24.3 Bq kg-1for 137Cs, respectively. The concentrations of these radio nuclides have been compared with the available data from the other countries. Natural environmental radioactivity and the associated external exposure due to gamma radiation depend primarily on the geological and geographical conditions. Namely, the specific levels of terrestrial environmental radiation are related to the type of rocks from which the soils originate. The obtained data indicate that the average value of activity of 232Th is about higher than the one of 226Ra The concentration of activity of 40К in the soil has greater value than 32Th and 226Ra in all soils. The causes for the existence of 137Cs in these soils are the nuclear explosions, waste radioactive materials and other incidents. It reaches the

  9. Statistical signal processing for gamma spectrometry: application for a pileup correction method; Traitement statistique du signal spectrometrique: etude du desempilement de spectre en energie pour la spectrometrie gamma

    Energy Technology Data Exchange (ETDEWEB)

    Trigano, T

    2005-12-15

    The main objective of gamma spectrometry is to characterize the radioactive elements of an unknown source by studying the energy of the emitted photons. When a photon interacts with a detector, its energy is converted into an electrical pulse. The histogram obtained by collecting the energies can be used to identify radioactive elements and measure their activity. However, at high counting rates, perturbations which are due to the stochastic aspect of the temporal signal can cripple the identification of the radioactive elements. More specifically, since the detector has a finite resolution, close arrival times of photons which can be modeled as an homogeneous Poisson process cause pile-ups of individual pulses. This phenomenon distorts energy spectra by introducing multiple fake spikes and prolonging artificially the Compton continuum, which can mask spikes of low intensity. The objective of this thesis is to correct the distortion caused by the pile-up phenomenon in the energy spectra. Since the shape of photonic pulses depends on many physical parameters, we consider this problem in a nonparametric framework. By introducing an adapted model based on two marked point processes, we establish a nonlinear relation between the probability measure associated to the observations and the probability density function we wish to estimate. This relation is derived both for continuous and for discrete time signals, and therefore can be used on a large set of detectors and from an analog or digital point of view. It also provides a framework to this problem, which can be considered as a problem of nonlinear density deconvolution and nonparametric density estimation from indirect measurements. Using these considerations, we propose an estimator obtained by direct inversion. We show that this estimator is consistent and almost achieves the usual rate of convergence obtained in classical nonparametric density estimation in the L{sup 2} sense. We have applied our method to a set

  10. The metrological activity determination of {sup 238} U and {sup 230} Th by gamma spectrometry to industrial fuel-cycle application

    Energy Technology Data Exchange (ETDEWEB)

    Almeida M, M.C. de; Delgado, J.U.; Poledna, R. [Instituto de Radioprotecao e Dosimetria- IRD/SEMRA, CNEN, Av. Salvador Allende s/n, Recreio, CEP 22780-160, Rio de Janeiro (Brazil)]. e-mail: marcandida@yahoo.com.br

    2006-07-01

    This work describes the difficulty for determining the activity of {sup 238} U and {sup 230} Th using gamma spectrometry due to the low gamma-ray emission probabilities of 92 and 67 keV, and, mainly, the associated high uncertainties about 13 and 11%, respectively. {sup 230} Th is a {sup 238} U daughter and it is product from uranium mills and refineries. {sup 230} Th decays to {sup 226} Ra and this decay has to be measured because these radionuclides are not in secular equilibrium with their daughter products, besides the gamma-energies have high uncertainties in the emission probabilities. These radionuclides, mostly {sup 238} U, are important in the nuclear fuel-cycle, since the mining of uranium ore, where the nominal isotopic content of natural uranium is 99.27% of {sup 238} U, until the irradiated fuel reprocessing, where this isotope, a fertile material, is recovered to be used again. The uranium and thorium are considered safeguarded nuclear materials and the metrology tries to calibrate and standardize these materials to improve the activity determination techniques applied in different fuel-cycle scopes. The essential characteristics of the safeguarded materials are low gamma energies (less than 100 keV) and emission probabilities but with high uncertainties. In this way, the metrology can contribute to homeland security defense against illicit nuclear trafficking with the identification and quantification of the safeguarded radionuclides such as uranium and thorium, using specific gamma window energy and high resolution planar or coaxial germanium detector. The efficiency curve is obtained from the reference source spectrum considering the photopeak areas corresponding the standard activities. This curve depends on radiation energy, sample geometry, photon attenuation (sample absorption and material absorption between sample-detector), dead time and sample-detector position. The metrological activity determinations of {sup 238} U solid sources, and of

  11. In Situ Aerosol Detector Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA is developing new platform systems that have the potential to benefit Earth science research activities, which include in situ instruments for atmospheric...

  12. Determination of {sup 226}Ra by gamma spectrometry: study of packaging vial of sample for analysis; Determinacao de {sup 226}Ra por espectrometria gama: estudo do recipiente de acondicionamento de amostra para analise

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, Andre Cavalcanti

    2015-07-01

    Determination of radioactivity levels of {sup 226}Ra by gamma spectrometry in a sample is based on measurements of {sup 214}Pb and {sup 214}Bi, daughters of {sup 222}Rn. Because radon is a gas, it can leak from the sample vial or accumulate on the upper empty it. If the vial has any crack, there will be loss of gas, which will cause error in determining the {sup 226}Ra concentration. One possible cause of cracks in the vials, that houses standards and samples, is the radiolysis action in the vial material, usually a polymer. As the demand {sup 226}Ra analysis in different matrices (geological samples, food, plants, etc.) is increasing, it was decided to study some polymer vials available on the market, to verify the feasibility to be used when is applied the analysis method using gamma spectrometry. Four types of polymer vials have been studied. The radiation doses in walls of the vials caused by natural radionuclides present in the sample were simulated using gamma irradiation. Tests, such as compressive strength test and tightness, were applied to the irradiated and non-irradiated vials. First, to verify the effect of radiolysis on the vial material and also if there was {sup 222}Rn diffusion in their walls. These preliminary results pointed out that the acrylic vials are the best option of packaging samples for analysis. This study should be repeated in a larger number of samples for a better evaluation. (author)

  13. Decision Threshold and Detection Limit in Spectrometric Measurements. Part 1: Application to Gamma Spectrometry; Umbral de Decision y Limite de Deteccion en Medidas Espectrometricas. Parte 1: Aplicacion a la Espectrometria Gamma

    Energy Technology Data Exchange (ETDEWEB)

    Perez, C.; Gasco, C.; Lopez, M.A.

    2010-03-03

    This report summarised the author's lecture of the advanced gamma spectrometry course organised by CIEMAT. The characteristic limits determination in gamma spectrometry generally is obtained through the programming that the trade marks offers to the client with the objective of the automatic calculation of the activity concentrations existing in a sample. In this report, the examples shown in the ISO 11929 standard are compared to the programming realised by Genie 2k for determining characteristic limits. The main difference of both is located in the uncertainty calculations due to the efficiency calibration that is considered by ISO and not by Genie 2K. Through implementation in the software developed by trade marks will be possible to introduce this uncertainty and to assimilate to the calculation done by ISO 11929. In the second part of this report will be analyzed the more complicated samples of this application as counting in a whole body counter (following ISO-28218 about Performance Criteria for radio bioassay), multiplet, overlapping, addition of several peaks for obtaining the activity concentration, etc. (Author) 19 refs.

  14. Study of Raman and IR Spectra for Si-Al-Zr-O Amorphous Bulk In-Situ Crystallization%Si-Al-Zr-O系非晶原位晶化过程中的拉曼光谱和红外光谱研究

    Institute of Scientific and Technical Information of China (English)

    谭小平; 梁叔全; 柴立元; 张国威; 张勇

    2011-01-01

    The structural changes in the in-situ controlled crystallizing process of Si-AI-Zr-O(SAZ) amorphous bulk were investigated by laser Ram. an (LRa), infrared (IR) and X-ray diffraction (XRD) techniques. The structure of the amorphous network apparently reorganized at about 920 ℃, resulting in the formation of Si-rich and Al, Zr-rich regions. The t-ZrO2 was crystallized from the Zr-rich region at 920~950 ℃ and poorly defined Al-Si spinel was formed from the Al-rich regions. With the increase in temperature, the peak of Al-Si spinel was enhanced and then disappeared in the XRD pattern, and the characteristic IR band groups of mullite centered in the 1 200~1 100, 1 000~700 and 650~400 em-1 could be observed. At 1 100~1 150 ℃,the Raman bands at 179 and 193 cm-1 typical for the m-ZrO2 occurred and cristobalite was detected, and the main crystalline phases were identified as t-ZrO2 and mullite. These results indicated that mullite was formed by reaction between amorphous silica and the Al-Si spinel which was metastable phase. During the heating process, t-ZrO2 was crystallized firstly and a portion was transformed to m-ZrO2 at high temperature, and the left amorphous silica was transformed to cristobalite.%借助Raman,IR和XRD等技术探讨了Si-Al-Zr-O系非晶在原位受控晶化过程中微结构变化.结果表明,Si-Al-Zr-O系非晶在920℃左右出现网络结构重整,形成了富Si区和富Zr和Al区.在920~950℃间,从富Zr区析出初晶相四方氧化锆,并从富Al区形成Al-Si尖晶石相.随着温度进一步升高,Al-Si尖晶石衍射峰先增强随后消失,同时在1 200~1 100,1 000~700和650~400cm-1观察到莫来石的红外特征峰;当温度升高至1 100~1 150℃,出现了单斜氧化锆的拉曼特征峰179和193cm1,同时形成了方石英,四方氧化锆和莫来石成为主晶相.说明在热处理过程中,Al不是以三氧化二铝形式析出而是先形成过渡AL-Si尖晶石相,随后与非晶二氧化硅反应

  15. Anatomy and histophysiology of the periosteum: quantification of the periosteal blood supply to the adjacent bone with 85Sr and gamma spectrometry.

    Science.gov (United States)

    Chanavaz, M

    1995-01-01

    The periosteum or periosteal membrane is a continuous composite fibroelastic covering membrane of the bone to which it is intimately linked. Although the bone cortex is the main beneficiary of the principal anatomical and physiological functions of the periosteal membrane, the behavior of the entire bone remains closely influenced by periosteal activity. These principal functions are related to the cortical blood supply, osteogenesis, and muscle and ligament attachments. Through its elastic and contractile nature, it participates in the maintenance of bone shape, and plays an important role in metabolic ionic exchange and physiologic distribution of electro-chemical potential differences across its membranous structure. It has also been suggested that the periosteum may have its own specific proprioceptive property. This paper presents a study of the anatomy and histophysiology of the periosteum, and discusses in detail its main functions of cortical blood supply and osteogenesis. It also presents the third intermediary report on a current study of the quantification of cortical vascularization of femoral bone via the periosteum, using an isotonic salt solution containing 85 Strontium. The afferent-efferent (arterio-venous) flows of this solution in the thigh vascular system of guinea pigs were measured by gamma spectrometry after a series of selective macro- and micro-injections of radioactive salt into the femoral arterial system was carried out. Each vascular territory was meticulously selected and the injections were made according to size, starting with the larger vessels, with or without ligatures of neighboring vessels, going progressively to smaller and smaller vessels with diameters not exceeding 100 microns. The principal technical difficulty at this stage of experimentation was related to the identifying and acquiring of appropriate microcatheters. The study also includes a series of measurements after blockage of the transmuscular blood flow and the

  16. In situ microbial filter used for bioremediation

    Science.gov (United States)

    Carman, M. Leslie; Taylor, Robert T.

    2000-01-01

    An improved method for in situ microbial filter bioremediation having increasingly operational longevity of an in situ microbial filter emplaced into an aquifer. A method for generating a microbial filter of sufficient catalytic density and thickness, which has increased replenishment interval, improved bacteria attachment and detachment characteristics and the endogenous stability under in situ conditions. A system for in situ field water remediation.

  17. Comparison of results at area 1 and area 2 between different Swedish in-situ teams in the RESUME-95 exercise

    Energy Technology Data Exchange (ETDEWEB)

    Raeaef, C.L. [Malmoe Univ. Hospital, Lund Univ., Dept. of Radiation Physics (Sweden)

    1997-12-31

    In the beginning of 1996 the Department of Radiation Physics in Malmoe was commissioned by the Swedish Radiation Protection Institute to perform a compilation of the results obtained by the Swedish in-situ teams that participated in the RESUME-95 exercise. The aim of this survey is to study the coherence in the reported activity data between the groups. It is not the purpose to see this comparison as a performance ranking of individual laboratories. Any such comparison must be made with precaution since the teams generally have collected their data with different equipment and by different methods. In this work, all in-situ teams have been given code-names, where each team has been labelled a number from 1 to 5. For more details, the interested reader is referred to the internal reports made by each team that (supposedly) also are to be included in the major compilation of the in-situ gamma spectrometry in the RESUME-95 exercise by Danish Emergency Management Agency. (au).

  18. Determination of activity by gamma spectrometry of radionuclides present in drums of residues generated in nuclear centrals; Determinacion de actividad por espectrometria gamma de radionucleidos presentes en tambores de residuos generados en centrales nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, J.C.; Fernandez, J. [Autoridad Regulatoria Nuclear, Av. Del Libertador 8250, Ciudad Autonoma de Buenos Aires (Argentina)]. e-mail: jaguiar@cae.arn.gov.ar

    2006-07-01

    The generation of radioactive residuals in nuclear centrals as CNA I (Atucha I Nuclear Central) and CNE (Embalse Nuclear Central) makes that the measurement of those radionuclides has been a previous stage to the waste management. A method used in those nuclear centrals it is the gamma spectrometry with HPGe detectors, previous to the immobilization of the residual in a cemented matrix, with this the contact with the external agents and its possible dispersion to the atmosphere in the short term is avoided. The ARN (Nuclear Regulatory Authority) of Argentina it carries out periodically intercomparisons and evaluations of the measurement and procedures systems used in the nuclear power stations for the correct measurement and determination of activity of radioactive residuals by gamma spectrometry. In this work an independent method of measurement is exposed to the nuclear power stations. To determine the activity of the residuals by gamma spectrometry deposited in drums, it is required of the precise knowledge of the efficiency curve for such geometry and matrix. Due to the RNA doesn't have a pattern of these characteristics, a mathematical model has been used to obtain this efficiency curve. For it, it is necessary to determine previously: 1) the geometric efficiency or solid angle sustained by the source-detector system (drum-detector) applying a mathematical model described in this work. 2) To estimate the auto-attenuation factor that present the photons in the cemented matrix, these calculations are carried out with a simple equation and its are verified with the Micro Shield 6.10 program. The container commonly used by these nuclear power stations its are drums for 220 liters constructed with SAE 1010 steel and with a thickness of 0.127 cm, with an approximate weight 7.73 Kg., internal diameter of 57.1 cm, and height: 87 cm. The results obtained until the moment register a discrepancy from 5 to 10% with relationship to the measurements carried out by the

  19. In situ bypass og diabetes

    DEFF Research Database (Denmark)

    Jensen, Leif Panduro; Schroeder, T V; Lorentzen, J E

    1993-01-01

    From 1986 through to 1990 a total of 483 in situ bypass procedures were performed in 444 patients. Preoperative risk-factors were equally distributed among diabetic (DM) and non-diabetic (NDM) patients, except for smoking habits (DM:48%, NDM:64%, p = 0.002) and cardiac disease (DM:45%, NDM:29%, p...

  20. In situ dehydration of yugawaralite

    DEFF Research Database (Denmark)

    Artioli, G.; Ståhl, Kenny; Cruciani, G.;

    2001-01-01

    The structural response of the natural zeolite yugawaralite (CaAl2Si6O16. 4H(2)O) upon thermally induced dehydration has been studied by Rietveld analysis of temperature-resolved powder diffraction data collected in situ in the temperature range 315-791 K using synchrotron radiation. The room-tem...

  1. In situ vadose zone bioremediation.

    Science.gov (United States)

    Höhener, Patrick; Ponsin, Violaine

    2014-06-01

    Contamination of the vadose zone with various pollutants is a world-wide problem, and often technical or economic constraints impose remediation without excavation. In situ bioremediation in the vadose zone by bioventing has become a standard remediation technology for light spilled petroleum products. In this review, focus is given on new in situ bioremediation strategies in the vadose zone targeting a variety of other pollutants such as perchlorate, nitrate, uranium, chromium, halogenated solvents, explosives and pesticides. The techniques for biostimulation of either oxidative or reductive degradation pathways are presented, and biotransformations to immobile pollutants are discussed in cases of non-degradable pollutants. Furthermore, research on natural attenuation in the vadose zone is presented.

  2. In Situ TEM Electrical Measurements

    DEFF Research Database (Denmark)

    Canepa, Silvia; Alam, Sardar Bilal; Ngo, Duc-The

    2016-01-01

    Transmission electron microscopy (TEM) offers high spatial and temporal resolution that provides unique information for understanding the function and properties of nanostructures on their characteristic length scales. Under controlled environmental conditions and with the ability to dynamically...... influence the sample by external stimuli, e.g. through electrical connections, the TEM becomes a powerful laboratory for performing quantitative real time in situ experiments. Such TEM setups enable the characterization of nanostructures and nanodevices under working conditions, thereby providing a deeper...... materials and devices with the specimen being contacted by electrical, mechanical or other means, with emphasis on in situ electrical measurements performed in a gaseous or liquid environment. We will describe the challenges and prospects of electrical characterization of devices and processes induced...

  3. Oldest biliary endoprosthesis in situ

    Science.gov (United States)

    Consolo, Pierluigi; Scalisi, Giuseppe; Crinò, Stefano F; Tortora, Andrea; Giacobbe, Giuseppa; Cintolo, Marcello; Familiari, Luigi; Pallio, Socrate

    2013-01-01

    The advantages of endoscopic retrograde cholangiopancreatography over open surgery have made it the predominant method of treating patients with choledocholithiasis. After sphincterotomy, however, 10%-15% of common bile duct stones cannot be removed with a basket or balloon. The methods for managing “irretrievable stones” include surgery, mechanical lithotripsy, intraductal or extracorporeal shock wave lithotripsy and biliary stenting. The case presented was a referred 82-year-old Caucasian woman with a 7-year-old plastic biliary endoprosthesis in situ. To the best of our knowledge the examined endoprosthesis is the oldest endoprosthesis in situ reported in the literature. Endoscopic biliary endoprosthesis placement remains a simple and safe procedure for patients with stones that are difficult to manage by conventional endoscopic methods and for patients who are unfit for surgery or who are high surgical risks. To date no consensus has been reached regarding how long a biliary prosthesis should remain in situ. Long-term biliary stenting may have a role in selected elderly patients if stones extraction has failed because the procedure may prevent stones impaction and cholangitis. PMID:23858381

  4. Noise canceling in-situ detection

    Science.gov (United States)

    Walsh, David O.

    2014-08-26

    Technologies applicable to noise canceling in-situ NMR detection and imaging are disclosed. An example noise canceling in-situ NMR detection apparatus may comprise one or more of a static magnetic field generator, an alternating magnetic field generator, an in-situ NMR detection device, an auxiliary noise detection device, and a computer.

  5. In Situ Instrumentation for Sub-Surface Planetary Geochemistry

    Science.gov (United States)

    Bodnarik, J.; Evans, L.; Floyd, S.; Lim, L.; McClanahan, T.; Namkung, M.; Parsons, A.; Schweitzer, J.; Starr, R.; Trombka, J.

    2010-01-01

    Novel instrumentation is under development at NASA's Goddard Space Flight Center, building upon earth-based techniques for hostile environments, to infer geochemical processes important to formation and evolution of solid bodies in our Solar System. A prototype instrument, the Pulsed Neutron Generator Gamma Ray and Neutron Detectors (PNG-GRAND), has a 14 MeV pulsed neutron generator coupled with gamma ray and neutron detectors to measure quantitative elemental concentrations and bulk densities of a number of major, minor and trace elements at or below the surfaces with approximately a meter-sized spatial resolution down to depths of about 50 cm without the need to drill. PNG-GRAND's in situ a meter-scale measurements and adaptability to a variety of extreme space environments will complement orbital kilometer-scale and in-situ millimeter scale elemental and mineralogical measurements to provide a more complete picture of the geochemistry of planets, moons, asteroids and comets.

  6. Bulk Superconductors in Mobile Application

    Science.gov (United States)

    Werfel, F. N.; Delor, U. Floegel-; Rothfeld, R.; Riedel, T.; Wippich, D.; Goebel, B.; Schirrmeister, P.

    We investigate and review concepts of multi - seeded REBCO bulk superconductors in mobile application. ATZ's compact HTS bulk magnets can trap routinely 1 T@77 K. Except of magnetization, flux creep and hysteresis, industrial - like properties as compactness, power density, and robustness are of major device interest if mobility and light-weight construction is in focus. For mobile application in levitated trains or demonstrator magnets we examine the performance of on-board cryogenics either by LN2 or cryo-cooler application. The mechanical, electric and thermodynamical requirements of compact vacuum cryostats for Maglev train operation were studied systematically. More than 30 units are manufactured and tested. The attractive load to weight ratio is more than 10 and favours group module device constructions up to 5 t load on permanent magnet (PM) track. A transportable and compact YBCO bulk magnet cooled with in-situ 4 Watt Stirling cryo-cooler for 50 - 80 K operation is investigated. Low cooling power and effective HTS cold mass drives the system construction to a minimum - thermal loss and light-weight design.

  7. Experimental Measurement of In Situ Stress

    Science.gov (United States)

    Tibbo, Maria; Milkereit, Bernd; Nasseri, Farzine; Schmitt, Douglas; Young, Paul

    2016-04-01

    The World Stress Map data is determined by stress indicators including earthquake focal mechanisms, in situ measurement in mining, oil and gas boreholes as well as the borehole cores, and geologic data. Unfortunately, these measurements are not only infrequent but sometimes infeasible, and do not provide nearly enough data points with high accuracy to correctly infer stress fields in deep mines around the world. Improvements in stress measurements of Earth's crust is fundamental to several industries such as oil and gas, mining, nuclear waste management, and enhanced geothermal systems. Quantifying the state of stress and the geophysical properties of different rock types is a major complication in geophysical monitoring of deep mines. Most stress measurement techniques involve either the boreholes or their cores, however these measurements usually only give stress along one axis, not the complete stress tensor. The goal of this project is to investigate a new method of acquiring a complete stress tensor of the in situ stress in the Earth's crust. This project is part of a comprehensive, exploration geophysical study in a deep, highly stressed mine located in Sudbury, Ontario, Canada, and focuses on two boreholes located in this mine. These boreholes are approximately 400 m long with NQ diameters and are located at depths of about 1300 - 1600 m and 1700 - 2000 m. Two borehole logging surveys were performed on both boreholes, October 2013 and July 2015, in order to perform a time-lapse analysis of the geophysical changes in the mine. These multi-parameter surveys include caliper, full waveform sonic, televiewer, chargeability (IP), and resistivity. Laboratory experiments have been performed on borehole core samples of varying geologies from each borehole. These experiments have measured the geophysical properties including elastic modulus, bulk modulus, P- and S-wave velocities, and density. The apparatus' used for this project are geophysical imaging cells capable

  8. Comparison of optimised germanium gamma spectrometry and multicollector inductively coupled plasma mass spectrometry for the determination of 134Cs, 137Cs and 154Eu single ratios in highly burnt UO 2

    Science.gov (United States)

    Caruso, S.; Günther-Leopold, I.; Murphy, M. F.; Jatuff, F.; Chawla, R.

    2008-05-01

    Non-destructive and destructive methods have been compared to validate their corresponding assessed accuracies in the measurement of 134Cs/137Cs and 154Eu/137Cs isotopic concentration ratios in four spent UO2 fuel samples with very high (52 and 71 GWd/t) and ultra-high (91 and 126 GWd/t) burnup values, and about 10 (in the first three samples) and 4 years (in the latter sample) cooling time. The non-destructive technique tested was high-resolution gamma spectrometry using a high-purity germanium detector (HPGe) and a special tomographic station for the handling of highly radioactive 400 mm spent fuel segments that included a tungsten collimator, lead filter (to enhance the signal to Compton background ratio and reduce the dead time) and paraffin wax (to reduce neutron damage). The non-destructive determination of these isotopic concentration ratios has been particularly challenging for these segments because of the need to properly derive non-Gaussian gamma-peak areas and subtract the background from perturbing capture gammas produced by the intrinsic high-intensity neutron emissions from the spent fuel. Additionally, the activity distribution within each pin was determined tomographically to correct appropriately for self-attenuation and geometrical effects. The ratios obtained non-destructively showed a 1σ statistical error in the range 1.9-2.9%. The destructive technique used was a high-performance liquid chromatographic separation system, combined online to a multicollector inductively coupled plasma mass spectrometer (HPLC-MC-ICP-MS), for the analysis of dissolved fuel solutions. During the mass spectrometric analyses, special care was taken in the optimisation of the chromatographic separation for Eu and the interfering element Gd, as also in the mathematical correction of the 154Gd background from the 154Eu signal. The ratios obtained destructively are considerably more precise (1σ statistical error in the range 0.4-0.8% for most of the samples, but up to

  9. Estimating Upper Mantle Hydration from In Situ Electrical Conductivity

    Science.gov (United States)

    Behrens, J.; Constable, S.; Heinson, G.; Everett, M.; Weiss, C.; Key, K.

    2004-12-01

    The electrical conductivity of 35-40 Ma Pacific plate has been measured in situ; one robust result is the presence of bulk anisotropy in the lithospheric upper mantle. We interpret this anisotropy to be a result of hydrothermal circulation into the upper mantle along spreading-ridge-parallel normal faults: the associated zones of serpentinized peridotite provide the pathways of enhanced electrical conductivity required by the data. Our modeling bounds the range of possible anisotropic ratios, which are then used to estimate the amount of water required to serpentinize the requisite amounts of peridotite. These data sets, however, do not indicate anisotropy in the bulk conductivity of the crust, nor in the asthenospheric mantle. This second point is significant, as recent measurements of sub-continental asthenospheric conductivity have been interpreted to indicate anisotropy aligned with present plate motion, with the diffusion of hydrogen through olivine advanced as an explanation.

  10. In-situ measurement of the electrical conductivity of aluminum oxide in HFIR

    Energy Technology Data Exchange (ETDEWEB)

    Zinkle, S.J.; White, D.P.; Snead, L.L. [Oak Ridge National Lab., TN (United States)] [and others

    1996-10-01

    A collaborative DOE/Monbusho irradiation experiment has been completed which measured the in-situ electrical resistivity of 12 different grades of aluminum oxide during HFIR neutron irradiation at 450{degrees}C. No evidence for bulk RIED was observed following irradiation to a maximum dose of 3 dpa with an applied dc electric field of 200 V/mm.

  11. In situ Raman spectroscopy of topological insulator BiTe films with varying thickness

    DEFF Research Database (Denmark)

    Wang, C.; Zhu, X.; Nilsson, Louis;

    2013-01-01

    Topological insulators (TIs) are a new state of quantum matter with a band gap in bulk and conducting surface states. In this work, the Raman spectra of topological insulator Bi2Te3 films prepared by molecular beam epitaxy (MBE) have been measured by an in situ ultrahigh vacuum (UHV...

  12. In Situ Soil Venting - Full Scale Test Hill AFB, Guidance Document, Literature Review. Volume 1

    Science.gov (United States)

    1991-08-01

    high bulk density to reduce diffusive path length. AWARE, Inc., (now Eckenfelder , Inc.) has performed experimental and theoretical work on in situ soil...operating guidance. The Eckenfelder work has continued with a one-year field study (Reference 33), consisting of a single 4-inch vent 20-foot-deep

  13. Radiological Mapping of the Alkaline Intrusive Complex of Jombo, South Coastal Kenya by In-Situ Gamma-Ray Spectrometry

    Science.gov (United States)

    Kaniu, Ian; Darby, Iain G.; Kalambuka Angeyo, Hudson

    2016-04-01

    Carbonatites and alkaline intrusive complexes are rich in a variety of mineral deposits such as rare earth elements (REEs), including Nb, Zr and Mn. These are often associated with U and Th bearing minerals, including monazite, samarskite and pyrochlore. Mining waste resulting from mineral processing activities can be highly radioactive and therefore poses a risk to human health and environment. The Jombo complex located in Kenya's south coastal region is potentially one of the richest sources of Nb and REEs in the world. It consists of the main intrusion at Jombo hill, three associated satellite intrusions at Mrima, Kiruku and Nguluku hills, and several dykes. The complex is highly heterogeneous with regard to its geological formation as it is characterized by alkaline igneous rocks and carbonatites which also influence its radio-ecological dynamics. In-situ gamma spectrometry offers a low-cost, rapid and spatially representative radioactivity estimate across a range of landscapes compared to conventional radiometric techniques. In this work, a wide ranging radiological survey was conducted in the Jombo complex as follow up on previous studies[1,2], to determine radiation exposure levels and source distributions, and perform radiological risk assessments. The in-situ measurements were carried out using a 2.0 l NaI(Tl) PGIS-2 portable detector from Pico Envirotec Inc integrated with GPS, deployed for ground (back-pack) and vehicular gamma-ray spectrometry. Preliminary results of radiological distribution and mapping will be presented. [1] Patel, J. P. (1991). Discovery and Innovation, 3(3): 31-35. [2] Kebwaro, J. M. et. al. (2011). J. Phys. Sci., 6(13): 3105-3110.

  14. The Tensions of In Situ Visualization.

    Science.gov (United States)

    Moreland, Kenneth

    2016-01-01

    In situ visualization is the coupling of visualization software with a simulation or other data producer to process the data "in memory" before the data are offloaded to a storage system. Although in situ visualization provides superior analysis, it has implementation tradeoffs resulting from conflicts with some traditional expected requirements. Numerous conflicting requirements create tensions that lead to difficult implementation tradeoffs. This article takes a look at the most prevailing tensions of in situ visualization.

  15. Calibration of the High Resolution Gamma Spectrometry Detection Systems from the Environmental Radioactivity Unit and Radiological Surveillance (ARU and RV); Calibracion de los Sistemas Detectores de Espectrometria Gamma de Alta Resolucion de la Unidad de Radiactividad Ambiental y Vigilancia Radiologica (URA y VR)

    Energy Technology Data Exchange (ETDEWEB)

    Suarez-Navarro, J. A.; Gasco, C.; Arana, M.; Suanez, A.

    2012-11-01

    In accordance with international regulations and with the quality criteria imposed by the internal quality system of the laboratory of gamma spectrometry, which belongs to the Unit of Environmental Radioactivity and Radiation Monitoring (URA y VR), it is necessary to perform a periodic calibration of the measurement systems of gamma spectrometry. The equipment calibration carries with the need for the preparation of the geometries of measurement and calibration in energy and in efficiencies. This report reflects the procedures for the preparation of the wide range of geometries available in the laboratory, as well as the different calibrations performed with those geometries in almost all the laboratory gamma detectors using the CANBERRA software Genie 2k. (Author) 9 refs.

  16. In situ nanoindentation in a transmission electron microscope

    Science.gov (United States)

    Minor, Andrew Murphy

    This dissertation presents the development of the novel mechanical testing technique of in situ nanoindentation in a transmission electron microscope (TEM). This technique makes it possible to simultaneously observe and quantify the mechanical behavior of nano-scale volumes of solids. Chapter 2 details the unique specimen preparation techniques employed to meet the geometrical constraints of the in situ experiments. These techniques include bulk silicon micromachining and the use of a focused ion beam. In section 2.4 a method of voltage-controlled mechanical testing is derived theoretically and proven experimentally. This method enables the quantification of the mechanical behavior during in situ nanoindentation experiments. Three classes of material systems were studied with this new technique: (1) bulk single crystal, (2) a soft thin film on a harder substrate and (3) a hard thin film on a softer substrate. Section 3.2 provides the first direct evidence of dislocation nucleation in single crystal silicon at room temperature. In contrast to the observation of phase transformations during conventional indentation experiments, the unique geometry employed for the in situ experiments resulted in dislocation plasticity. In section 3.3 results from in situ nanoindentation of Al films on Si substrates are presented. These results include the correlation of the microstructural deformation behavior with load vs. displacement data. It is shown that a sharp change in the force-displacement response at the elastic-to-plastic transition signifies the nucleation of dislocations. Additionally, the softening of sub-micron grains with size is observed. Section 3.4 discussed the influence of the substrate on the indentation response of two thin film/substrate systems where the films were harder than the substrate. Amorphous diamond on Si and epitaxial TiN on MgO (001) systems were studied. It was found that the deformation in the harder films was controlled by the deformation in

  17. Calibration of a Gamma Spectrometry System Used for the Determination of Cs-137 in Spanish Soils; Puesta a Punto de un sistema de Expectrometria Gamma para la Determinacion de Cs-137 en Suelos Espanoles

    Energy Technology Data Exchange (ETDEWEB)

    Barreraa, M.; Romero, M. L.; Valino, F.

    2008-07-01

    The document describes the methodology used at CIEMAT in order to determine, by gamma spectrometry, the background levels of the radionuclide Cs-137 in soils of the Spanish peninsular territory. the work is a part of an extensive research project developed jointly by the University of the Basque Country (UPV-EHU) and the CIEMAT, endellite Content and migration of radiocaesium and radiostrontium in Spanish soils, which is funded by the Plan I+D of the Spanish Nuclear Security Council (CSN). The objective of the project is to establish the reference levels of man-made radionuclides in Spanish soils, with respect to which the evaluation of a possible posterior accidental release of radioactive material could be appraised. The activity concentration of the fission products Cs-137 has been determined in 34 soil cores extracted from representative Spanish soils type zones. This publication describes the experimental system employed, its calibration, the particular conditions applied to perform the measurements, as well as the experimental validation of the methodology. The activity profiles and inventories of the radioactive element so obtained are also presented. The estimation of the background Cs-137 reference levels, will provide a basis for later applications as the study of the spatial distribution in the region, the determination of the correlation between the deposited activity and the meteorological conditions, or the calculation of the specific migration parameters of the radioactive elements in Mediterranean conditions. (Author) 15 refs.

  18. [Study of "living" radical polymerization by FTIR in situ].

    Science.gov (United States)

    Chen, J; Hua, F; Qiu, J; Yang, Y

    2001-02-01

    Three types of living radical polymerization processes were monitored by means of FTIR spectrometer with handful diamond detector called as Dicomp in situ. It was found that both styrene and styrene/hydroxylpropyl methyacrylate (HPMA) could polymerize according to stable free radical polymerization (SFRP) mechanism in presence of 4-hydroxyl tetramethypiperidiyl-1-oxy(HTEMPO). For styrene/HPMA system, the styrene and HPMA conversion monitored by FTIR were linear with increase of molecular weight, but it gave longer induction period compared with that for St bulk polymerization. It was related to the hydrogen-transfer reaction between the propagating radicals with the end HPMA unit and HTEMPO. Furthermore, This following method in situ could be introduced into monitoring heterogeneous polymerization of styrene during atom transfer radical polymerization (ATRP). The apparent kinetics was found to be about zero order and not 1.0 order, due to propagating on the complex including radicals, CuX and bpy in heterogeneous interface. The polymerization rate will be not related to the St in bulk St phase.

  19. Chemically enhanced in situ recovery

    Energy Technology Data Exchange (ETDEWEB)

    Sale, T. [CH2M Hill, Denver, CO (United States); Pitts, M.; Wyatt, K. [Surtek, Inc., Golden, CO (United States)] [and others

    1996-08-01

    Chemically enhanced recovery is a promising alternative to current technologies for management of subsurface releases of organic liquids. Through the inclusion of surfactants, solvents, polymers, and/or alkaline agents to a waterflood, the transport of targeted organic compounds can be increased and rates of recovery enhanced. By far, the vast majority of work done in the field of chemically enhanced recovery has been at a laboratory scale. The following text focuses on chemically enhanced recovery from a field application perspective with emphasis given to chlorinated solvents in a low permeability setting. While chlorinated solvents are emphasized, issues discussed are also relevant to organic liquids less dense than water such as petroleum products. Topics reviewed include: (1) Description of technology; (2) General technology considerations; (3) Low permeability media considerations; (4) Cost and reliability considerations; (5) Commercial availability; and (6) Case histories. Through this paper an appreciation is developed of both the potential and limitations of chemically enhanced recovery. Excluded from the scope of this paper is the in situ destruction of organic compounds through processes such as chemical or biological oxidation, chemically enhanced recovery of inorganic compounds, and ex situ soil treatment processes. 11 refs., 2 figs., 1 tab.

  20. Four Models of In Situ Simulation

    DEFF Research Database (Denmark)

    Musaeus, Peter; Krogh, Kristian; Paltved, Charlotte

    2014-01-01

    that there are four fruitful approaches to in situ simulation: (1) In situ simulation informed by reported critical incidents and adverse events from emergency departments (ED) in which team training is about to be conducted to write scenarios. (2) In situ simulation through ethnographic studies at the ED. (3) Using...... prewritten scenarios from the simulation lab and transferring them to in situ simulation. (4) Action research – insider or participant action research to obtain in-depth understanding of team processes to guide scenario design. We evaluate the approach relying on Marks’ et al. taxonomy that posits...... the following processes: Transition processes, Action processes and Interpersonal processes. Design and purpose This abstract suggests four approaches to in situ simulation. A pilot study will evaluate the different approaches in two emergency departments in the Central Region of Denmark. Methods The typology...

  1. Usefulness of systematic in situ gamma-ray surveys in the radiometric characterization of natural systems with poorly contrasting geological features (examples from NE of Portugal)

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, Pedro [Instituto Tecnologico e Nuclear, Unidade de Proteccao e Seguranca Radiologica, Estrada Nacional no10, Apartado 21, 2686-953 Sacavem (Portugal); Departamento de Geologia e CeGUL, Faculdade de Ciencias da Universidade de Lisboa, Campo Grande, Edificio C6, 1749-016 Lisboa (Portugal); Mateus, Antonio [Departamento de Geologia e CeGUL, Faculdade de Ciencias da Universidade de Lisboa, Campo Grande, Edificio C6, 1749-016 Lisboa (Portugal); Paiva, Isabel, E-mail: ipaiva@itn.p [Instituto Tecnologico e Nuclear, Unidade de Proteccao e Seguranca Radiologica, Estrada Nacional no10, Apartado 21, 2686-953 Sacavem (Portugal); Trindade, Romao [Instituto Tecnologico e Nuclear, Unidade de Proteccao e Seguranca Radiologica, Estrada Nacional no10, Apartado 21, 2686-953 Sacavem (Portugal); Santos, Pedro [Instituto Tecnologico e Nuclear, Unidade de Proteccao e Seguranca Radiologica, Estrada Nacional no10, Apartado 21, 2686-953 Sacavem (Portugal); Departamento de Geologia e CeGUL, Faculdade de Ciencias da Universidade de Lisboa, Campo Grande, Edificio C6, 1749-016 Lisboa (Portugal)

    2011-02-15

    This paper focuses on the starting point of various studies that are being carried out in two possible locations being considered to host a hypothetical site for a repository for low and intermediate level radioactive waste (LILW) produced in Portugal in compliance with international requirements on the long-term safety of this kind of repository. Previous studies concerning the geology of the much larger geographical areas where these locations are included were fundamental in the choice of these locations and for the design of the survey strategy. One of the fundamental assessment studies during the site-selection is the overall radiological characterization of the locations and its relation to the geology. This paper pretends to show the adequability of using a fast and reasonably inexpensive survey technique such as in situ gamma-ray portable detectors, to access the radiometric response of the systems in study by providing the radiometric mapping of the areas. The existence of adequate radiometric maps represents a critical pre-requisite to constrain both the number and spatial distribution of samples to be collected for further analysis, sustaining as well the subsequent extrapolation of results needed to fully characterise the surveyed system. Both areas were surveyed using portable gamma-ray spectrometers with NaI(Tl) detectors. In situ gamma-ray measurements have clearly shown not only the poorly contrasting geological features, but also their differences representing: (i) a deformed/metamorphosed ophiolite complex and (ii) a monotonous meta-sedimentary sequence. The radiometric maps obtained have show heterogeneities that reflect mostly changes in rock-forming mineral assemblages, even in the presence of small variations of gamma radiation. These maps support objective criteria about the number/distribution of samples to be collected for subsequent comprehensive studies and reinforce the valuable contribution of in situ gamma spectrometry to assess, in

  2. in situ Calcite Precipitation for Contaminant Immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Yoshiko Fujita; Robert W. Smith

    2009-08-01

    in situ Calcite Precipitation for Contaminant Immobilization Yoshiko Fujita (Yoshiko.fujita@inl.gov) (Idaho National Laboratory, Idaho Falls, Idaho, USA) Robert W. Smith (University of Idaho-Idaho Falls, Idaho Falls, Idaho, USA) Subsurface radionuclide and trace metal contaminants throughout the U.S. Department of Energy (DOE) complex pose one of DOE’s greatest challenges for long-term stewardship. One promising stabilization mechanism for divalent trace ions, such as the short-lived radionuclide strontium-90, is co-precipitation in calcite. Calcite, a common mineral in the arid western U.S., can form solid solutions with trace metals. The rate of trace metal incorporation is susceptible to manipulation using either abiotic or biotic means. We have previously demonstrated that increasing the calcite precipitation rate by stimulating the activity of urea hydrolyzing microorganisms can result in significantly enhanced Sr uptake. Urea hydrolysis causes the acceleration of calcium carbonate precipitation (and trace metal co-precipitation) by increasing pH and alkalinity, and also by liberating the reactive cations from the aquifer matrix via exchange reactions involving the ammonium ion derived from urea: H2NCONH2 + 3H2O ? 2NH4+ + HCO3- + OH- urea hydrolysis >X:2Ca + 2NH4+ ? 2>X:NH4 + Ca2+ ion exchange Ca2+ + HCO3- + OH- ? CaCO3(s) + H2O calcite precipitation where >X: is a cation exchange site on the aquifer matrix. This contaminant immobilization approach has several attractive features. Urea hydrolysis is catalyzed by the urease enzyme, which is produced by many indigenous subsurface microorganisms. Addition of foreign microbes is unnecessary. In turn the involvement of the native microbes and the consequent in situ generation of reactive components in the aqueous phase (e.g., carbonate and Ca or Sr) can allow dissemination of the reaction over a larger volume and/or farther away from an amendment injection point, as compared to direct addition of the reactants at

  3. In Situ TEM Creation of Nanowire Devices

    DEFF Research Database (Denmark)

    Alam, Sardar Bilal

    Integration of silicon nanowires (SiNWs) as active components in devices requires that desired mechanical, thermal and electrical interfaces can be established between the nanoscale geometry of the SiNW and the microscale architecture of the device. In situ transmission electron microscopy (TEM...... of SiNW were also investigated in situ. SiNWs were grown on silicon microcantilever heaters using the VLS mechanism. When grown across a gap between adjacent cantilevers, contact was formed when the SiNW impinged on the sidewall of an adjacent cantilever. Using in situ TEM, SiNW contact formation...

  4. Observatory Magnetometer In-Situ Calibration

    Directory of Open Access Journals (Sweden)

    A Marusenkov

    2011-07-01

    Full Text Available An experimental validation of the in-situ calibration procedure, which allows estimating parameters of observatory magnetometers (scale factors, sensor misalignment without its operation interruption, is presented. In order to control the validity of the procedure, the records provided by two magnetometers calibrated independently in a coil system have been processed. The in-situ estimations of the parameters are in very good agreement with the values provided by the coil system calibration.

  5. In-situ characterization of heterogeneous catalysts

    CERN Document Server

    Rodriguez, Jose A; Chupas, Peter J

    2013-01-01

    Helps researchers develop new catalysts for sustainable fuel and chemical production Reviewing the latest developments in the field, this book explores the in-situ characterization of heterogeneous catalysts, enabling readers to take full advantage of the sophisticated techniques used to study heterogeneous catalysts and reaction mechanisms. In using these techniques, readers can learn to improve the selectivity and the performance of catalysts and how to prepare catalysts as efficiently as possible, with minimum waste. In-situ Characterization of Heterogeneous Catalysts feat

  6. A MEMS Device for in-situ TEM Test of SCS Nanobeam

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In-situ tensile testing in TEM (transmission electron microscopy) is a useful tool for studying mechanical properties of nano-structures because it can provide quanti-tative information on sample deformation at atomic scale. To facilitate in-situ TEM tensile tests of SCS (single crystal silicon) nanobeam, a MEMS tensile-testing chip was designed and fabricated. The chip was fabricated by means of bulk micro-machining and wafer bonding techniques. An SCS nanobeam, a comb drive ac-tuator, a force sensor beam and an electron beam window were integrated into the chip. With the on-chip comb-drive-actuator stretching the nanobeam and in-situ TEM observation, tensile test on a 90 nm-thick nanobeam was performed and the strain-stress relationship was obtained. The Young’s modulus was fitted to be 161 GPa and did not show the size effect.

  7. A MEMS Device for in-situ TEM Test of SCS Nanobeam

    Institute of Scientific and Technical Information of China (English)

    JIN QinHua; WANG YueLin; LI Tie; LI XinXin; XU FangFang

    2008-01-01

    In-situ tensile testing in TEM (transmission electron microscopy) is a useful tool for studying mechanical properties of nano-structures because it can provide quanti- tative information on sample deformation at atomic scale. To facilitate in-situ TEM tensile testa of SCS (single crystal silicon) nanobeam, a MEMS tensile-testing chip was designed and fabricated. The chip was fabricated by means of bulk micro- machining and wafer bonding techniques. An SCS nanobeam, a comb drive ac- tuator, a force sensor beam and an electron beam window were integrated into the chip. With the on-chip comb-drive-actuator stretching the nanobeam and in-situ TEM observation, tensile test on a 90 nm-thick nanobeam was performed and the strain-stress relationship was obtained. The Young's modulus was fitted to be 161 GPa and did not show the size effect.

  8. In situ microcosms in aquifer bioremediation studies.

    Science.gov (United States)

    Mandelbaum, R T; Shati, M R; Ronen, D

    1997-07-01

    The extent to which aquifer microbiota can be studied under laboratory or simulated conditions is limited by our inability to authentically duplicate natural conditions in the laboratory. Therefore, extrapolation of laboratory results to real aquifer situations is often criticized, unless validation of the data is performed in situ. Reliable data acquisition is critical for the estimation of chemical and biological reaction rates of biodegradation processes in groundwater and as input data for mathematical models. Typically, in situ geobiochemical studies relied on the injection of groundwater spiked with compounds or bacteria of interest into the aquifer, followed by monitoring the changes over time and space. In situ microcosms provide a more confined study site for measurements of microbial reactions, yet closer to natural conditions than laboratory microcosms. Two basic types of in situ aquifer microcosm have been described in recent years, and both originated from in situ instruments initially designed for geochemical measurements. Gillham et al. [Ground Water 28 (1990) 858-862] constructed an instrument that isolates a portion of an aquifer for in situ biochemical rate measurements. More recently Shati et al. [Environ. Sci. Technol. 30 (1996) 2646-2653] modified a multilayer sampler for studying the activity of inoculated bacteria in a contaminated aquifer Keeping in mind recent advances in environmental microbiology methodologies such as immunofluorescence direct counts, oligonucleotide and PCR probes, fatty acid methyl esther analysis for the detection and characterization of bacterial communities, measurement of mRNA and expression of proteins, it is evident that much new information can now be gained from in situ work. Using in situ microcosms to study bioremediation efficiencies, the fate of introduced microorganisms and general geobiochemical aquifer processes can shed more realistic light on the microbial underworld. The aim of this paper is to

  9. Petrologic and In Situ Geochemical Constraints on Diogenite Genesis

    Science.gov (United States)

    Mittlefehldt, David W.; Peng, Z. X.

    2013-01-01

    Diogenites, members of the howardite, eucrite and diogenite (HED) clan, are orthopyroxenite, harzburgite and dunite meteorites [1-3]. Most are breccias, but remnant textures indicate they were originally coarse-grained rocks, with grain sizes of order of cm. Their petrography and compositions support an origin as crustal cumulates from a differentiated asteroid. Astronomical observations, and surface mineralogy and composition of Vesta determined by the Dawn spacecraft suggest that asteroid (4) Vesta is the parent object for HED meteorites [4-6]. The origin of diogenites is an unsettled issue. It is difficult to fit their bulk compositional characteristics into global magma ocean models that successfully describe the compositions of basaltic and cumulate eucrites [7]. Compositional analyses of acid-leached bulk samples have led to the hypothesis that many diogenites were formed late by interaction of their parent melts with a eucritic crust [8]. Those observations may alternatively be explained by subsolidus equilibration of trace elements between orthopyroxene and minor/ accessory phases in the rocks such as plagioclase and phosphate [7]. These competing hypotheses can be tested through in situ measurements of trace and minor elements in orthopyroxene. Our new petrologic observations and in situ minor and trace element data for a suite of diogenites are used to discuss the petrologic evolution of diogenites. Our preliminary data on two diogenites are consistent with the hypothesis that subsolidus element mobilization processes caused unusual trace element signatures seen in some diogenites [7]. We cannot stress strongly enough, however, that the sample set is too small and that additional data are required before definitive conclusions can be made.

  10. Structure and properties of nanocrystalline rare earth bulks prepared by spark plasma sintering

    Institute of Scientific and Technical Information of China (English)

    卢年端; 宋晓艳; 刘雪梅; 张久兴

    2009-01-01

    A series of rare earth bulks with the ultrafine nanocrystalline structure were prepared by applying an "oxygen-free" (an environmental oxygen concentration less than 0.5 ppm) in-situ synthesis system, where the inert-gas condensation was combined with the spark plasma sintering technology into an entirely closed system. The thermal and mechanical properties of the prepared ultrafine nanocrystalline bulks were characterized and compared with those of the raw polycrystalline bulks. It was found that the speci...

  11. Detection of colony-stimulating factor messenger RNA in single T cells by in situ hybridization

    DEFF Research Database (Denmark)

    Williamson, D J; Owens, T; Pearse, M

    1989-01-01

    In situ hybridization has been used to study the accumulation of colony-stimulating factor (CSF) mRNA in single cells of a T lymphocyte clone (E9.D4) following antibody-mediated (F23.1) activation via the Ti-T3 complex in filler-independent bulk cultures. The specificity of hybridization for cell......In situ hybridization has been used to study the accumulation of colony-stimulating factor (CSF) mRNA in single cells of a T lymphocyte clone (E9.D4) following antibody-mediated (F23.1) activation via the Ti-T3 complex in filler-independent bulk cultures. The specificity of hybridization...

  12. In Situ Surface X-Ray Scattering of Metal Monolayers Adsorbed at Solid-Liquid Interfaces

    Science.gov (United States)

    1991-11-09

    important experimental aspects of’ these in-situ experiments are described, and after this, we explain underpotential electrochemical deposition (MPI...subtracted from the data in the calculation Of Qad" 3. UNDERPOTENTIAL DEPOSITION The electrochemical deposition of metal layers onto a foreign netal...for bulk deposition .1 5. 16 This process is termed underpotential deposition (UiPl)), and on single crystals, these initial deposits have been

  13. In Situ Monitoring and Mechanism of the Mechanochemical Formation of a Microporous MOF-74 Framework.

    Science.gov (United States)

    Julien, Patrick A; Užarević, Krunoslav; Katsenis, Athanassios D; Kimber, Simon A J; Wang, Timothy; Farha, Omar K; Zhang, Yuancheng; Casaban, José; Germann, Luzia S; Etter, Martin; Dinnebier, Robert E; James, Stuart L; Halasz, Ivan; Friščić, Tomislav

    2016-03-09

    Mechanochemistry provides a rapid, efficient route to metal-organic framework Zn-MOF-74 directly from a metal oxide and without bulk solvent. In situ synchrotron X-ray diffraction monitoring of the reaction course reveals two new phases and an unusual stepwise process in which a close-packed intermediate reacts to form the open framework. The reaction can be performed on a gram scale to yield a highly porous material after activation.

  14. Pulse Plating on Gold Surfaces Studied by In Situ Scanning Tunneling Microscopy

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Bech-Nielsen, Gregers; Møller, Per

    1994-01-01

    Deposition of bulk copper on thin film gold surfaces is carried out by computer-aided pulse plating. It is demonstrated that the morphology of the copper deposit can be studied by in situ scanning tunnelling microscopy both in potentiostatic experiments and in galvanostatic experiments. Optimized...... procedures for obtaining smooth deposits by pulse plating are explained in terms of a levelling effect. Possible non-faradaic processes observed in measurements with high frequency pulse plating are discussed....

  15. In situ solid-state NMR for heterogeneous catalysis: a joint experimental and theoretical approach.

    Science.gov (United States)

    Zhang, Weiping; Xu, Shutao; Han, Xiuwen; Bao, Xinhe

    2012-01-07

    In situ solid-state NMR is a well-established tool for investigations of the structures of the adsorbed reactants, intermediates and products on the surface of solid catalysts. The techniques allow identifications of both the active sites such as acidic sites and reaction processes after introduction of adsorbates and reactants inside an NMR rotor under magic angle spinning (MAS). The in situ solid-state NMR studies of the reactions can be achieved in two ways, i.e. under batch-like or continuous-flow conditions. The former technique is low cost and accessible to the commercial instrument while the latter one is close to the real catalytic reactions on the solids. This critical review describes the research progress on the in situ solid-state NMR techniques and the applications in heterogeneous catalysis under batch-like and continuous-flow conditions in recent years. Some typical probe molecules are summarized here to detect the Brønsted and Lewis acidic sites by MAS NMR. The catalytic reactions discussed in this review include methane aromatization, olefin selective oxidation and olefin metathesis on the metal oxide-containing zeolites. With combining the in situ MAS NMR spectroscopy and the density functional theoretical (DFT) calculations, the intermediates on the catalyst can be identified, and the reaction mechanism is revealed. Reaction kinetic analysis in the nanospace instead of in the bulk state can also be performed by employing laser-enhanced MAS NMR techniques in the in situ flow mode (163 references).

  16. An In-situ XPS study of non-evaporable ZrVFe getter material

    Directory of Open Access Journals (Sweden)

    Jang-Hee Yoon

    2010-03-01

    Full Text Available To investigate the temperature dependence of a synthesized Zr57V36Fe7 non evaporable vacuum getter material, the in-situ temperature x-ray photoelectron spectroscopy (in-situ XPS were performed in a UHV chamber equipped with a programmable ceramic sample heating system. The surface and bulk composition of Zr, V, and Ti was determined in the as-received state and after in-situ heating from 50℃ to 600℃ at 50℃per step. The peak fitting results for O 1s, C 1s, Zr 3d, V 2p, and Fe 2p high resolution spectra were acquired and the chemical state of the elements were then characterized as a function of heating temperature. In-situ XPS investigations showed that oxide reduction proceeds via the formation of sub-oxides with the simultaneous formation of carbides in the region near the surface. The activation temperature for completion of the Zr57V36Fe7 alloy, which approximates the XPS peaks changed from oxide to metallic state(20 % of the oxide peak, was determined around 480℃. The findings suggest that the in-situ temperature XPS technique is a useful analytical tool for evaluating activation characteristics of NEG materials.

  17. In situ macromolecular crystallography using microbeams.

    Science.gov (United States)

    Axford, Danny; Owen, Robin L; Aishima, Jun; Foadi, James; Morgan, Ann W; Robinson, James I; Nettleship, Joanne E; Owens, Raymond J; Moraes, Isabel; Fry, Elizabeth E; Grimes, Jonathan M; Harlos, Karl; Kotecha, Abhay; Ren, Jingshan; Sutton, Geoff; Walter, Thomas S; Stuart, David I; Evans, Gwyndaf

    2012-05-01

    Despite significant progress in high-throughput methods in macromolecular crystallography, the production of diffraction-quality crystals remains a major bottleneck. By recording diffraction in situ from crystals in their crystallization plates at room temperature, a number of problems associated with crystal handling and cryoprotection can be side-stepped. Using a dedicated goniometer installed on the microfocus macromolecular crystallography beamline I24 at Diamond Light Source, crystals have been studied in situ with an intense and flexible microfocus beam, allowing weakly diffracting samples to be assessed without a manual crystal-handling step but with good signal to noise, despite the background scatter from the plate. A number of case studies are reported: the structure solution of bovine enterovirus 2, crystallization screening of membrane proteins and complexes, and structure solution from crystallization hits produced via a high-throughput pipeline. These demonstrate the potential for in situ data collection and structure solution with microbeams.

  18. In situ viscometry by optical trapping interferometry

    DEFF Research Database (Denmark)

    Guzmán, C.; Flyvbjerg, Henrik; Köszali, R.

    2008-01-01

    We demonstrate quantitative in situ viscosity measurements by tracking the thermal fluctuations of an optically trapped microsphere subjected to a small oscillatory flow. The measured power spectral density of the sphere's positions displays a characteristic peak at the driving frequency of the f......We demonstrate quantitative in situ viscosity measurements by tracking the thermal fluctuations of an optically trapped microsphere subjected to a small oscillatory flow. The measured power spectral density of the sphere's positions displays a characteristic peak at the driving frequency...

  19. In situ preparation of Nanoparticles/polymer composites

    Institute of Scientific and Technical Information of China (English)

    SUN HaiZhu; YANG Bai

    2008-01-01

    Nanoparticle (NP) is the matter between molecule and bulk material. It has attracted much attention in catalysis, optoelectronics and biology due to its unique physical and chemical properties. Incorporation of these NPs into the polymer matrix is one of the best methods to display their special functions, which not only stabilize the NPs but also realize the functional assembly of NPs and polymers. However, reali-zation of this idea depends largely on the compatibility of NPs and polymers as well as the interaction between them. Therefore, many methods have been developed to prepare the composites of NPs and polymers in order to obtain the function ex-pected. In this review, we mainly focus on the combination of in situ method with other methods to synthesize different functional one-dimension, two-dimension as well as bulk composites, which has been recently developed by our group. The most striking character of our method is the excellent compatibility between NPs and polymers which ensures a homogeneous distribution of NPs in the polymer matrix. The existence of the polymer network makes the NPs more stable, and is significant for displaying their functions.

  20. In situ preparation of Nanoparticles/polymer composites

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Nanoparticle (NP) is the matter between molecule and bulk material. It has attracted much attention in catalysis, optoelectronics and biology due to its unique physical and chemical properties. Incorporation of these NPs into the polymer matrix is one of the best methods to display their special functions, which not only stabilize the NPs but also realize the functional assembly of NPs and polymers. However, reali- zation of this idea depends largely on the compatibility of NPs and polymers as well as the interaction between them. Therefore, many methods have been developed to prepare the composites of NPs and polymers in order to obtain the function ex- pected. In this review, we mainly focus on the combination of in situ method with other methods to synthesize different functional one-dimension, two-dimension as well as bulk composites, which has been recently developed by our group. The most striking character of our method is the excellent compatibility between NPs and polymers which ensures a homogeneous distribution of NPs in the polymer matrix. The existence of the polymer network makes the NPs more stable, and is significant for displaying their functions.

  1. Large area bulk superconductors

    Science.gov (United States)

    Miller, Dean J.; Field, Michael B.

    2002-01-01

    A bulk superconductor having a thickness of not less than about 100 microns is carried by a polycrystalline textured substrate having misorientation angles at the surface thereof not greater than about 15.degree.; the bulk superconductor may have a thickness of not less than about 100 microns and a surface area of not less than about 50 cm.sup.2. The textured substrate may have a thickness not less than about 10 microns and misorientation angles at the surface thereof not greater than about 15.degree.. Also disclosed is a process of manufacturing the bulk superconductor and the polycrystalline biaxially textured substrate material.

  2. Treatment options for carcinoma in situ testis

    DEFF Research Database (Denmark)

    Mortensen, M S; Gundgaard, M.G.; Daugaard, G

    2011-01-01

    Carcinoma in situ testis (CIS) is known as the precursor of germ cell cancer of the testis. International guidelines on diagnosis and treatment are inconsistent. Some countries offer routine biopsies of the contralateral testicle in relation to orchidectomy for testicular cancer, whereas other...

  3. Carcinoma in situ in the testis

    DEFF Research Database (Denmark)

    Rørth, M; Rajpert-De Meyts, E; Andersson, L;

    2000-01-01

    Carcinoma in situ (CIS) of the testis is a common precursor of germ-cell tumours in adults and adolescents, with the exception of spermatocytic seminoma. This article reviews existing knowledge on the pathobiology, genetic aspects and epidemiology of CIS, discusses current hypotheses concerning...

  4. Unannounced in situ simulation of obstetric emergencies

    DEFF Research Database (Denmark)

    Sørensen, Jette Led; Lottrup, Pernille; van der Vleuten, Cees;

    2014-01-01

    AIM: To describe how unannounced in situ simulation (ISS) was perceived by healthcare professionals before and after its implementation, and to describe the organisational impact of ISS. STUDY DESIGN: Ten unannounced ISS involving all staff were scheduled March-August 2007. Questionnaire surveys ...

  5. In Situ Remediation Integrated Program: Technology summary

    Energy Technology Data Exchange (ETDEWEB)

    1994-02-01

    The In Situ Remediation Integrated Program (ISR IP) was instituted out of recognition that in situ remediation could fulfill three important criteria: significant cost reduction of cleanup by eliminating or minimizing excavation, transportation, and disposal of wastes; reduced health impacts on workers and the public by minimizing exposure to wastes during excavation and processing; and remediation of inaccessible sites, including: deep subsurfaces, in, under, and around buildings. Buried waste, contaminated soils and groundwater, and containerized wastes are all candidates for in situ remediation. Contaminants include radioactive wastes, volatile and non-volatile organics, heavy metals, nitrates, and explosive materials. The ISR IP intends to facilitate development of in situ remediation technologies for hazardous, radioactive, and mixed wastes in soils, groundwater, and storage tanks. Near-term focus is on containment of the wastes, with treatment receiving greater effort in future years. ISR IP is an applied research and development program broadly addressing known DOE environmental restoration needs. Analysis of a sample of 334 representative sites by the Office of Environmental Restoration has shown how many sites are amenable to in situ remediation: containment--243 sites; manipulation--244 sites; bioremediation--154 sites; and physical/chemical methods--236 sites. This needs assessment is focused on near-term restoration problems (FY93--FY99). Many other remediations will be required in the next century. The major focus of the ISR EP is on the long term development of permanent solutions to these problems. Current needs for interim actions to protect human health and the environment are also being addressed.

  6. Elastic properties of Pd40Cu30Ni10P20 bulk glass in supercooled liquid region

    DEFF Research Database (Denmark)

    Nishiyama, N.; Inoue, A.; Jiang, Jianzhong

    2001-01-01

    In situ ultrasonic measurements for the Pd40Cu30Ni10P20 bulk glass in three states: Glassy solid, supercooled liquid, and crystalline, have been performed. It is found that velocities of both longitudinal and transverse waves and elastic moduli (shear modulus, bulk modulus, Young's modulus, and L...

  7. New in situ crosslinking chemistries for hydrogelation

    Science.gov (United States)

    Roberts, Meredith Colleen

    Over the last half century, hydrogels have found immense value as biomaterials in a vast number of biomedical and pharmaceutical applications. One subset of hydrogels receiving increased attention is in situ forming gels. Gelling by either bioresponsive self-assembly or mixing of binary crosslinking systems, these technologies are useful in minimally invasive applications as well as drug delivery systems in which the sol-to-gel transition aids the formulation's performance. Thus far, the field of in situ crosslinking hydrogels has received limited attention in the development of new crosslinking chemistries. Moreover, not only does the chemical nature of the crosslinking moieties allow these systems to perform in situ, but they contribute dramatically to the mechanical properties of the hydrogel networks. For example, reversible crosslinks with finite lifetimes generate dynamic viscoelastic gels with time-dependent properties, whereas irreversible crosslinks form highly elastic networks. The aim of this dissertation is to explore two new covalent chemistries for their ability to crosslink hydrogels in situ under physiological conditions. First, reversible phenylboronate-salicylhydroxamate crosslinking was implemented in a binary, multivalent polymeric system. These gels formed rapidly and generated hydrogel networks with frequency-dependent dynamic rheological properties. Analysis of the composition-structure-property relationships of these hydrogels---specifically considering the effects of pH, degree of polymer functionality, charge of the polymer backbone and polymer concentration on dynamic theological properties---was performed. These gels demonstrate diverse mechanical properties, due to adjustments in the binding equilibrium of the pH-sensitive crosslinks, and thus have the potential to perform in a range of dynamic or bioresponsive applications. Second, irreversible catalyst-free "click" chemistry was employed in the hydrogelation of multivalent azide

  8. In situ SU-8 silver nanocomposites

    DEFF Research Database (Denmark)

    Fischer, Søren Vang; Uthuppu, Basil; Jakobsen, Mogens Havsteen

    2015-01-01

    to this problem, an easy new method of fabricating silver nanocomposites by an in situ reduction of precursors within the epoxy-based photoresist SU-8 has been developed. AgNO3 dissolved in acetonitrile and mixed with the epoxy-based photoresist SU-8 forms silver nanoparticles primarily during the pre- and post......Nanocomposite materials containing metal nanoparticles are of considerable interest in photonics and optoelectronics applications. However, device fabrication of such materials always encounters the challenge of incorporation of preformed nanoparticles into photoresist materials. As a solution......-exposure soft bake steps at 95 degrees C. A further high-temperature treatment at 300 degrees C resulted in the formation of densely homogeneously distributed silver nanoparticles in the photoresist matrix. No particle growth or agglomeration of nanoparticles is observed at this point. The reported new in situ...

  9. Inherently safe in situ uranium recovery

    Science.gov (United States)

    Krumhansl, James L; Brady, Patrick V

    2014-04-29

    An in situ recovery of uranium operation involves circulating reactive fluids through an underground uranium deposit. These fluids contain chemicals that dissolve the uranium ore. Uranium is recovered from the fluids after they are pumped back to the surface. Chemicals used to accomplish this include complexing agents that are organic, readily degradable, and/or have a predictable lifetime in an aquifer. Efficiency is increased through development of organic agents targeted to complexing tetravalent uranium rather than hexavalent uranium. The operation provides for in situ immobilization of some oxy-anion pollutants under oxidizing conditions as well as reducing conditions. The operation also artificially reestablishes reducing conditions on the aquifer after uranium recovery is completed. With the ability to have the impacted aquifer reliably remediated, the uranium recovery operation can be considered inherently safe.

  10. In situ health monitoring of piezoelectric sensors

    Science.gov (United States)

    Jensen, Scott L. (Inventor); Drouant, George J. (Inventor)

    2013-01-01

    An in situ health monitoring apparatus may include an exciter circuit that applies a pulse to a piezoelectric transducer and a data processing system that determines the piezoelectric transducer's dynamic response to the first pulse. The dynamic response can be used to evaluate the operating range, health, and as-mounted resonance frequency of the transducer, as well as the strength of a coupling between the transducer and a structure and the health of the structure.

  11. Squamous cell carcinoma in situ after irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kambara, Takeshi; Nishiyama, Takafumi; Yamada, Rie; Nagatani, Tetsuo; Nakajima, Hiroshi [Yokohama City Univ. (Japan). School of Medicine; Sugiyama, Asami

    1997-12-31

    We report two cases with Squamous Cell Carcinoma (SCC) in situ caused by irradiation to hand eczemas, resistant to any topical therapies. Both of our cases clinically show palmer sclerosis and flexor restriction of the fingers, compatible to chronic radiation dermatitis. Although SCC arising in chronic radiation dermatitis is usually developed ten to twenty years after irradiation, in our cases SCC were found more than forty years after irradiation. (author)

  12. In situ models, physico-chemical aspects.

    Science.gov (United States)

    ten Cate, J M

    1994-07-01

    In situ (intra-oral) caries models are used for two purposes. First, they provide information about oral physiological processes. Such information helps to detail our knowledge of the oral ecosystem and to verify conclusions from in vitro experiments. Second, in situ models are utilized to test preventive agents in the phase between laboratory testing and clinical trials. Most investigations involving enamel inserts have been aimed at testing new dentifrices. The experimental designs of such studies usually do not allow one to draw conclusions on physico-chemical processes, e.g., because of single point measurements. Studies of model parameters (lesion type, lesion severity, and de/remineralization in time) constitute only a minority of the research reports. The most striking observation obtained with in situ models has been the significant differences in de/remineralization observed among individuals and, more importantly, within one individual during different time periods and between different sites in the same mouth (for review, see ten Cate et al., 1992). Regardless of this, some general findings can be inferred: During in situ demineralization, up to 62 vol% microns/day may be removed from enamel. For dentin specimens, this value may be as high as 89 vol% microns/day. For remineralization, during fluoride dentifrice treatment, a median deposition rate of 0.7%/day (for lesions with integrated mineral loss values between 2000 and 4000 vol% microns) is found. The rate of deposition seems to be correlated with the extent of the pre-formed lesion. This suggests that the number of sites (crystallite surface) available for calcium phosphate precipitation is an important parameter.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. In situ hybridization-theory and practice.

    Science.gov (United States)

    Kadkol, S S; Gage, W R; Pasternack, G R

    1999-09-01

    In situ hybridization is a technique to determine and localize target nucleic acids in morphologically preserved tissue sections. Recent advances in methods have greatly increased the sensitivity of the technique, and it is currently possible to detect extremely few copies of any given target sequence with nonisotopic methods. In this teaching review, we integrate theoretical background, technical considerations, and guidelines for usage for this important component of molecular diagnosis.

  14. In situ Raman mapping of art objects

    Science.gov (United States)

    Lauwers, D.; Brondeel, Ph.; Moens, L.; Vandenabeele, P.

    2016-12-01

    Raman spectroscopy has grown to be one of the techniques of interest for the investigation of art objects. The approach has several advantageous properties, and the non-destructive character of the technique allowed it to be used for in situ investigations. However, compared with laboratory approaches, it would be useful to take advantage of the small spectral footprint of the technique, and use Raman spectroscopy to study the spatial distribution of different compounds. In this work, an in situ Raman mapping system is developed to be able to relate chemical information with its spatial distribution. Challenges for the development are discussed, including the need for stable positioning and proper data treatment. To avoid focusing problems, nineteenth century porcelain cards are used to test the system. This work focuses mainly on the post-processing of the large dataset which consists of four steps: (i) importing the data into the software; (ii) visualization of the dataset; (iii) extraction of the variables; and (iv) creation of a Raman image. It is shown that despite the challenging task of the development of the full in situ Raman mapping system, the first steps are very promising. This article is part of the themed issue "Raman spectroscopy in art and archaeology".

  15. In situ ion irradiation of zirconium carbide

    Science.gov (United States)

    Ulmer, Christopher J.; Motta, Arthur T.; Kirk, Mark A.

    2015-11-01

    Zirconium carbide (ZrC) is a candidate material for use in one of the layers of TRISO coated fuel particles to be used in the Generation IV high-temperature, gas-cooled reactor, and thus it is necessary to study the effects of radiation damage on its structure. The microstructural evolution of ZrCx under irradiation was studied in situ using the Intermediate Voltage Electron Microscope (IVEM) at Argonne National Laboratory. Samples of nominal stoichiometries ZrC0.8 and ZrC0.9 were irradiated in situ using 1 MeV Kr2+ ions at various irradiation temperatures (T = 20 K-1073 K). In situ experiments made it possible to continuously follow the evolution of the microstructure during irradiation using diffraction contrast imaging. Images and diffraction patterns were systematically recorded at selected dose points. After a threshold dose during irradiations conducted at room temperature and below, black-dot defects were observed which accumulated until saturation. Once created, the defect clusters did not move or get destroyed during irradiation so that at the final dose the low temperature microstructure consisted only of a saturation density of small defect clusters. No long-range migration of the visible defects or dynamic defect creation and elimination were observed during irradiation, but some coarsening of the microstructure with the formation of dislocation loops was observed at higher temperatures. The irradiated microstructure was found to be only weakly dependent on the stoichiometry.

  16. Bulk chemicals from biomass

    NARCIS (Netherlands)

    Haveren, van J.; Scott, E.L.; Sanders, J.P.M.

    2008-01-01

    Given the current robust forces driving sustainable production, and available biomass conversion technologies, biomass-based routes are expected to make a significant impact on the production of bulk chemicals within 10 years, and a huge impact within 20-30 years. In the Port of Rotterdam there is a

  17. In situ synthesis studies of silicon clathrates

    Science.gov (United States)

    Hutchins, Peter Thomas

    Solid state clathrates have shown considerable potential as a new class of materials over the past 30 years. Experimental and theoretical studies have shown that precise tuning and synthetic control of these materials, may lead to desirable properties. Very little is known about the mechanism of formation of the clathrates and so the desire to have accurate synthetic control was, until now, unrealistic. This thesis address the problem using in situ synchrotron x-ray techniques. In this study, experiments were designed to utilise time-resolved in situ diffraction techniques and high temperature 23Na NMR, in efforts to understand the mechanism of formation for this class of expanded framework materials. A complex high vacuum capillary synthesis cell was designed for loading under inert conditions and operation under high vacuum at station 6.2 of the SRS Daresbury. The cell was designed to operate in conjunction with a custom made furnace capable of temperatures in excess of 1000 C, as well as a vacuum system capable of 10"5 bar. The clathrate system was studied in situ, using rapid data collection to elucidate the mechanism of formation. The data were analysed using Rietveld methods and showed a structural link between the monoclinic, C2/c, Zintl precursors and the cubic, Pm3n, clathrate I phase. The phases were found to be linked by relation of the sodium planes in the silicide and the sodium atoms resident at cages centres in the clathrate system. This evidence suggests the guest species is instrumental in formation of the clathrate structure by templating the formation of the cages in the structure. Solid state 23Na NMR was utilised to complete specially design experiments, similar to those complete in situ using synchrotron x-ray techniques. The experiments showed increased spherical symmetry of the alkali metal sites and suggested increased mobility of the guest atoms during heating. In addition, cyclic heating experiments using in situ diffraction showed

  18. 30 CFR 828.12 - In situ processing: Monitoring.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false In situ processing: Monitoring. 828.12 Section 828.12 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE... PROCESSING § 828.12 In situ processing: Monitoring. (a) Each person who conducts in situ...

  19. 30 CFR 828.11 - In situ processing: Performance standards.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false In situ processing: Performance standards. 828.11 Section 828.11 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT... STANDARDS-IN SITU PROCESSING § 828.11 In situ processing: Performance standards. (a) The person who...

  20. Enhanced magnetic moment of ultrathin Co films measured by in situ electrodeposition in a SQUID

    Science.gov (United States)

    Topolovec, Stefan; Krenn, Heinz; Würschum, Roland

    2016-01-01

    A special electrochemical cell enabling in situ electrodeposition in a SQUID magnetometer is applied to study the magnetic moment of ultrathin Co films during growth on an Au(111) substrate. The in situ electrodeposition approach allows a total elimination of the magnetic background signal of the substrate, thus the magnetic moment which arises exclusively from the deposited Co film could be measured with monolayer sensitivity. The average thickness of the deposited Co films dav as determined from the transferred charge can be adjusted easily by varying the parameters of the electrodeposition. Hence, the magnetic moment of Co thin films could be determined in absolute terms as a function of the film thickness dav. For the first few atomic layers an enhancement of the magnetic moment per Co atom compared to the bulk could be observed, which increases steadily with lowering dav, reaching up to 40%.

  1. An in-situ heater for the XAS beamline (12-ID) in Australia

    Science.gov (United States)

    Johannessen, B.; Hussain, Z. S.; East, D. R.; Gibson, M. A.

    2013-04-01

    To accommodate for a growing number of requests by our user community an in-situ heater has been commissioned for the X-ray absorption spectroscopy (XAS) beamline 12-ID at the Australian Synchrotron. Here, we present an in-situ method for calibrating the temperature of the heating stage based on an anharmonic, correlated Einstein model. Specifically, we show that a temperature-dependant study of a bulk metallic foil (7.5 μm Cu) can be used to accurately calibrate the temperature of the heater. We also present the temperature-dependant coordination number, bond length, Debye-Waller factor, and third order cumulant to the bond length distribution function of the material from 18K to 1074K. At the higher temperatures we find that the atomic structure is comparable to that of an amorphous or liquid material indicating a gradual transition from crystalline to disordered atomic structure.

  2. Characterization of Gas-Solid Reactions using In Situ Powder X-ray Diffraction

    DEFF Research Database (Denmark)

    Møller, Kasper Trans; Hansen, Bjarne Rosenlund Søndertoft; Dippel, Ann-Christin;

    2014-01-01

    X-ray diffraction is a superior technique for structural characterization of crystalline matter. Here we review the use of in situ powder X-ray diffraction (PXD) mainly for real-time studies of solid/gas reactions, data analysis and the extraction of valuable knowledge of structural, chemical...... and physical properties. Furthermore, the diffraction data may also provide knowledge on reaction mechanisms, kinetics and thermodynamic properties. Thus, in situ PXD simultaneously provides properties as a function of pressure, temperature and/or time at different length scales, i.e. nanoscale structural data...... and bulk sample properties. Initially, a brief description of experimental and methodological details is provided, followed by a variety of examples of different designs of experiments and methods of data analysis. Additionally, it is discussed how a range of physical properties can be accessed...

  3. Bulk fabrication and properties of solar grade silicon microwires

    Directory of Open Access Journals (Sweden)

    F. A. Martinsen

    2014-11-01

    Full Text Available We demonstrate a substrate-free novel route for fabrication of solar grade silicon microwires for photovoltaic applications. The microwires are fabricated from low purity starting material via a bulk molten-core fibre drawing method. In-situ segregation of impurities during the directional solidification of the fibres yields solar grade silicon cores (microwires where the concentration of electrically detrimental transition metals has been reduced between one and two orders of magnitude. The microwires show bulk minority carrier diffusion lengths measuring ∼40 μm, and mobilities comparable to those of single-crystal silicon. Microwires passivated with amorphous silicon yield diffusion lengths comparable to those in the bulk.

  4. In-situ polymerization behaviour of bone cements.

    Science.gov (United States)

    Maffezzoli, A; Ronca, D; Guida, G; Pochini, I; Nicolais, L

    1997-02-01

    The polymerization behaviour of bone cements during total hip replacements is characterized by a fast and highly non-isothermal bulk reaction. In the first part of this paper the reaction kinetics are analysed by calorimetric analysis in order to determine the rates of polymerization in isothermal and non-isothermal conditions. A phenomenological kinetic model, accounting for the effects of autoacceleration and vitrification, is presented. This model, integrated with an energy balance, is capable of predicting the temperature across the prosthesis, the cement and the bone and the degree of reaction in the cement, during in situ polymerization. The temperature and the degree of reaction profiles are calculated, as a function of the setting time, taking into account the system geometry, the thermal diffusivity of bone, prosthesis and cement, and the heat rate generated by the reaction according to the kinetic model. Material properties, boundary and initial conditions are the input data of the heat transfer model. Kinetic and heat transfer models are coupled and a numerical solution method is used. The model is applied in order to study the effects of different application procedures on temperature and degree of reaction profiles across the bone-cement-prosthesis system.

  5. Detection of denitrification genes by in situ rolling circle amplification - fluorescence in situ hybridization (in situ RCA-FISH) to link metabolic potential with identity inside bacterial cells

    DEFF Research Database (Denmark)

    Hoshino, Tatsuhiko; Schramm, Andreas

    2010-01-01

    A target-primed in situ rolling circle amplification (in situ RCA) protocol was developed for detection of single-copy genes inside bacterial cells and optimized with Pseudomonas stutzeri, targeting nitrite and nitrous oxide reductase genes (nirS and nosZ). Two padlock probes were designed per gene...... as Candidatus Accumulibacter phosphatis by combining in situ RCA-FISH with 16S rRNA-targeted FISH. While not suitable for quantification because of its low detection frequency, in situ RCA-FISH will allow to link metabolic potential with 16S rRNA (gene)-based identification of single microbial cells....

  6. Radiative Bulk Viscosity

    CERN Document Server

    Chen, X

    2001-01-01

    Viscous resistance to changes in the volume of a gas arises when different degrees of freedom have different relaxation times. Collisions tend to oppose the resulting departures from equilibrium and, in so doing, generate entropy. Even for a classical gas of hard spheres, when the mean free paths or mean flight times of constituent particles are long, we find a nonvanishing bulk viscosity. Here we apply a method recently used to uncover this result for a classical rarefied gas to radiative transfer theory and derive an expression for the radiative stress tensor for a gray medium with absorption and Thomson scattering. We determine the transport coefficients through the calculation of the comoving entropy generation. When scattering dominates absorption, the bulk viscosity becomes much larger than either the shear viscosity or the thermal conductivity.

  7. In-situ thermal testing program strategy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    In the past year the Yucca Mountain Site Characterization Project has implemented a new Program Approach to the licensing process. The Program Approach suggests a step-wise approach to licensing in which the early phases will require less site information than previously planned and necessitate a lesser degree of confidence in the longer-term performance of the repository. Under the Program Approach, the thermal test program is divided into two principal phases: (1) short-term in situ tests (in the 1996 to 2000 time period) and laboratory thermal tests to obtain preclosure information, parameters, and data along with bounding information for postclosure performance; and (2) longer-term in situ tests to obtain additional data regarding postclosure performance. This effort necessitates a rethinking of the testing program because the amount of information needed for the initial licensing phase is less than previously planned. This document proposes a revised and consolidated in situ thermal test program (including supporting laboratory tests) that is structured to meet the needs of the Program Approach. A customer-supplier model is used to define the Project data needs. These data needs, along with other requirements, were then used to define a set of conceptual experiments that will provide the required data within the constraints of the Program Approach schedule. The conceptual thermal tests presented in this document represent a consolidation and update of previously defined tests that should result in a more efficient use of Project resources. This document focuses on defining the requirements and tests needed to satisfy the goal of a successful license application in 2001, should the site be found suitable.

  8. Design Games for In-Situ Design

    DEFF Research Database (Denmark)

    Kristiansen, Erik

    2013-01-01

    The mobile culture has spawned a host of context-based products, like location-based and tag-based applications. This presents a new challenge for the designer. There is a need of design methods that acknowledge the context and allows it to influence the design ideas. This article focuses...... on a design problem where an in-situ design practice may further the early design process: the case of designing a pervasive game. Pervasive games are computer games, played using the city as a game board and often using mobile phones with GPS. Some contextual design methods exist, but we propose an approach...

  9. Ekstrauterin graviditet med gestagenspiral in situ

    DEFF Research Database (Denmark)

    Mikkelsen, Mette Schou; Bor, Isil Pinar; Højgaard, Astrid Ditte

    2010-01-01

    The levonorgestrel-releasing intrauterine device (IUD) (Mirena) is a frequently used and effective method of contraception, with a Pearl index of 0.1. The ectopic pregnancy rate is 0.02 per 100 woman-years. Special attention is needed in situations where pregnancy is detected with a levonorgestrel......-releasing IUD in situ, because almost two thirds of these pregnancies are ectopic. We describe one of these rare cases of ectopic pregnancy in a woman aged 37 years, who was admitted to hospital with abdominal pain and vaginal bleeding....

  10. Computer Aided in situ Cognitive Behavioral Therapy

    DEFF Research Database (Denmark)

    Chongtay, Rocio A.; Hansen, John Paulin; Decker, Lone

    2006-01-01

    . One of the most common and successfully used treatments for phobic conditions has been Cognitive Behavioral Therapy (CBT), which helps people learn to detect thinking patterns that trigger the irrational fear and to replace them with more realistic ideas. The health and financial impacts in society...... presented here is being designed in a modular and scalable fashion. The web-based module can be accessed anywhere any time from a PC connected to the internet and can be used alone or as supplement for a location-based module for in situ gradual exposure therapy....

  11. In situ rheology of yeast biofilms.

    Science.gov (United States)

    Brugnoni, Lorena I; Tarifa, María C; Lozano, Jorge E; Genovese, Diego

    2014-01-01

    The aim of the present work was to investigate the in situ rheological behavior of yeast biofilms growing on stainless steel under static and turbulent flow. The species used (Rhodototula mucilaginosa, Candida krusei, Candida kefyr and Candida tropicalis) were isolated from a clarified apple juice industry. The flow conditions impacted biofilm composition over time, with a predominance of C. krusei under static and turbulent flow. Likewise, structural variations occurred, with a tighter appearance under dynamic flow. Under turbulent flow there was an increase of 112 μm in biofilm thickness at 11 weeks (p rheology and contribute to a thin body of knowledge about fungal biofilm formation.

  12. In situ viscometry by optical trapping interferometry

    Science.gov (United States)

    Guzmán, Camilo; Flyvbjerg, Henrik; Köszali, Roland; Ecoffet, Carole; Forró, László; Jeney, Sylvia

    2008-11-01

    We demonstrate quantitative in situ viscosity measurements by tracking the thermal fluctuations of an optically trapped microsphere subjected to a small oscillatory flow. The measured power spectral density of the sphere's positions displays a characteristic peak at the driving frequency of the flow, which is simply proportional to the viscosity, when measured in units of the thermal power spectral density at the same frequency. Measurements are validated on different water-glycerol mixtures, as well as in a glycerol gradient, where no a priori knowledge of the solution is used to determine the glycerol concentration.

  13. In Situ Preservation of Historic Spacecraft

    Science.gov (United States)

    Barclay, R.; Brooks, R.

    The loss of the Mir space station is shown to symbolize a new consciousness of the value of space artefacts. The reasons why such artefacts as Mir become historic objects worthy of preservation are examined. Preservation of space vehicles in situ is discussed, with particular reference to safety, monitoring and long term costs. An argument is made for a wider definition for World Heritage designations to include material beyond the surface of the Earth, and for international bodies to assess, monitor and oversee these projects. Such heritage sites are seen as an economic driver for the development of space tourism in the 21st century.

  14. Polypropylene/graphite nanocomposites by in situ polymerization; Nanocompositos polipropileno/grafite via polimerizacao in situ

    Energy Technology Data Exchange (ETDEWEB)

    Milani, Marceo A.; Galland, Giselda B., E-mail: griselda@iq.ufrgs.br [Instituto de Quimica, UFRGS, Porto Alegre, RS (Brazil); Quijada, Raul [Universidade de Chile, Santiago (Chile). Centro de Ciencias de los Materiales; Basso, Nara R.S. [Fac. de Quimica, PUCRS, Porto Alegre, RS (Brazil)

    2011-07-01

    This work presents the synthesis of nanocomposites of polypropylene/graphite by in situ polymerization using metallocene catalyst and graphene nanosheets. Initially was analyzed which of the metallocene catalysts rac-Et(Ind){sub 2}ZrCl{sub 2} or rac-Me{sub 2}Si(Ind){sub 2}ZrCl{sub 2} produces polypropylene with mechanical properties more relevant. Then it were performed the in situ polymerization reactions to obtain the nanocomposites. The polymeric materials were characterized by XRD, DSC, GPC and DMTA. (author)

  15. High-order harmonic generation in a plasma plume of in situ laser-produced silver nanoparticles

    Science.gov (United States)

    Singhal, H.; Ganeev, R. A.; Naik, P. A.; Chakera, J. A.; Chakravarty, U.; Vora, H. S.; Srivastava, A. K.; Mukherjee, C.; Navathe, C. P.; Deb, S. K.; Gupta, P. D.

    2010-10-01

    The results of the experimental study of high-order harmonic generation (HHG) from the interaction of 45-fs Ti:sapphire laser pulses with plasma plumes of Ag nanoparticles produced in situ are presented in this article. The nanoparticles were generated by the interaction of 300-ps, 20-mJ laser pulses with bulk silver targets at an intensity of ~1×1013W/cm2. The spectral characteristics of the HHG from nanoparticles produced in situ are compared with the HHG from monoparticle plasma plumes and with the HHG from preformed nanoparticle-containing plasma plumes. The cutoff harmonic order generated using the in situ silver nanoparticles is at the 21st harmonic order.

  16. Size-induced enhancement of bulk modulus and transition pressure of nanocrystalline Ge

    DEFF Research Database (Denmark)

    Wang, Hua; Liu, J.F.; He, Yongqi;

    2007-01-01

    In situ energy dispersive X-ray diffraction measurements with synchrotron radiation source have been performed on nanocrystalline Ge with particle sizes 13, 49 and 100 nm by using diamond anvil cell. Whereas the percentage volume collapse at the transition is almost constant, the values of the bulk...

  17. Watching the growth of bulk grains during recrystallization of deformed metals

    DEFF Research Database (Denmark)

    Schmidt, Søren; Fæster Nielsen, Søren; Gundlach, C.;

    2004-01-01

    We observed the in situ growth of a grain during recrystallization in the bulk of a deformed sample. We used the three-dimensional x-ray diffraction microscope located at the European Synchrotron Radiation Facility in Grenoble, France. The results showed a very heterogeneous growth pattern...

  18. In Situ Flash Pyrolysis of Straw

    DEFF Research Database (Denmark)

    Bech, Niels

    aske og reducere logistikomkostningerne ville gøre denne alternative energikilde betydelig mere attraktiv. Disse mål kan nås med in situ flash pyrolyse, hvor halm bliver omdannet til bio-olie i marken og koks efterlades på jorden for at forbedre jordstrukturen og tilføre mineraler. Hovedformålene med...... dette Innovations Ph.d. projekt var at understøtte udviklingen af en reaktor til in situ flash pyrolyse, konstruere et mindre stationært pilotanlæg, karakterisere og teste halm bio-olie som flydende brændstof samt udvikle en forretningsplan for kommercialisering af de opnåede resultater. Yderligere var...... det ønsket at undersøge flash pyrolyse af halm generelt og udvikle et værktøj, der kunne modellere den udviklede reaktors opførsel. De eksperimentelle resultater udgør den første rapporterede systematiske undersøgelse af halm flash pyrolyse i en ablativ (solid convective) reaktor. Modellering af...

  19. Molecular cytogenetics using fluorescence in situ hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Gray, J.W.; Kuo, Wen-Lin; Lucas, J.; Pinkel, D.; Weier, H-U.; Yu, Loh-Chung.

    1990-12-07

    Fluorescence in situ hybridization (FISH) with chromosome-specific probes enables several new areas of cytogenetic investigation by allowing visual determination of the presence and normality of specific genetic sequences in single metaphase or interphase cells. in this approach, termed molecular cytogenetics, the genetic loci to be analyzed are made microscopically visible in single cells using in situ hybridization with nucleic acid probes specific to these loci. To accomplish this, the DNA in the target cells is made single stranded by thermal denaturation and incubated with single-stranded, chemically modified probe under conditions where the probe will anneal only with DNA sequences to which it has high DNA sequence homology. The bound probe is then made visible by treatment with a fluorescent reagent such as fluorescein that binds to the chemical modification carried by the probe. The DNA to which the probe does not bind is made visible by staining with a dye such as propidium iodide that fluoresces at a wavelength different from that of the reagent used for probe visualization. We show in this report that probes are now available that make this technique useful for biological dosimetry, prenatal diagnosis and cancer biology. 31 refs., 3 figs.

  20. In situ SU-8 silver nanocomposites

    Directory of Open Access Journals (Sweden)

    Søren V. Fischer

    2015-07-01

    Full Text Available Nanocomposite materials containing metal nanoparticles are of considerable interest in photonics and optoelectronics applications. However, device fabrication of such materials always encounters the challenge of incorporation of preformed nanoparticles into photoresist materials. As a solution to this problem, an easy new method of fabricating silver nanocomposites by an in situ reduction of precursors within the epoxy-based photoresist SU-8 has been developed. AgNO3 dissolved in acetonitrile and mixed with the epoxy-based photoresist SU-8 forms silver nanoparticles primarily during the pre- and post-exposure soft bake steps at 95 °C. A further high-temperature treatment at 300 °C resulted in the formation of densely homogeneously distributed silver nanoparticles in the photoresist matrix. No particle growth or agglomeration of nanoparticles is observed at this point. The reported new in situ silver nanocomposite materials can be spin coated as homogeneous thin films and structured by using UV lithography. A resolution of 5 µm is achieved in the lithographic process. The UV exposure time is found to be independent of the nanoparticle concentration. The fabricated silver nanocomposites exhibit high plasmonic responses suitable for the development of new optoelectronic and optical sensing devices.

  1. Inherently safe in situ uranium recovery.

    Energy Technology Data Exchange (ETDEWEB)

    Krumhansl, James Lee; Beauheim, Richard Louis; Brady, Patrick Vane; Arnold, Bill Walter; Kanney, Joseph F.; McKenna, Sean Andrew

    2009-05-01

    Expansion of uranium mining in the United States is a concern to some environmental groups and sovereign Native American Nations. An approach which may alleviate some problems is to develop inherently safe in situ uranium recovery ('ISR') technologies. Current ISR technology relies on chemical extraction of trace levels of uranium from aquifers that, once mined, can still contain dissolved uranium and other trace metals that are a health concern. Existing ISR operations are few in number; however, high uranium prices are driving the industry to consider expanding operations nation-wide. Environmental concerns and enforcement of the new 30 ppb uranium drinking water standard may make opening new mining operations more difficult and costly. Here we propose a technological fix: the development of inherently safe in situ recovery (ISISR) methods. The four central features of an ISISR approach are: (1) New 'green' leachants that break down predictably in the subsurface, leaving uranium, and associated trace metals, in an immobile form; (2) Post-leachant uranium/metals-immobilizing washes that provide a backup decontamination process; (3) An optimized well-field design that increases uranium recovery efficiency and minimizes excursions of contaminated water; and (4) A combined hydrologic/geochemical protocol for designing low-cost post-extraction long-term monitoring. ISISR would bring larger amounts of uranium to the surface, leave fewer toxic metals in the aquifer, and cost less to monitor safely - thus providing a 'win-win-win' solution to all stakeholders.

  2. GAS TURBINE REHEAT USING IN SITU COMBUSTION

    Energy Technology Data Exchange (ETDEWEB)

    D.M. Bachovchin; T.E. Lippert; R.A. Newby P.G.A. Cizmas

    2004-05-17

    In situ reheat is an alternative to traditional gas turbine reheat design in which fuel is fed through airfoils rather than in a bulky discrete combustor separating HP and LP turbines. The goals are to achieve increased power output and/or efficiency without higher emissions. In this program the scientific basis for achieving burnout with low emissions has been explored. In Task 1, Blade Path Aerodynamics, design options were evaluated using CFD in terms of burnout, increase of power output, and possible hot streaking. It was concluded that Vane 1 injection in a conventional 4-stage turbine was preferred. Vane 2 injection after vane 1 injection was possible, but of marginal benefit. In Task 2, Combustion and Emissions, detailed chemical kinetics modeling, validated by Task 3, Sub-Scale Testing, experiments, resulted in the same conclusions, with the added conclusion that some increase in emissions was expected. In Task 4, Conceptual Design and Development Plan, Siemens Westinghouse power cycle analysis software was used to evaluate alternative in situ reheat design options. Only single stage reheat, via vane 1, was found to have merit, consistent with prior Tasks. Unifying the results of all the tasks, a conceptual design for single stage reheat utilizing 24 holes, 1.8 mm diameter, at the trailing edge of vane 1 is presented. A development plan is presented.

  3. In situ combustion field experiences in Venezuela

    Energy Technology Data Exchange (ETDEWEB)

    Villalba, M.; Estrada, M.; Bolivar, J. [INTEVEP, Caracas (Venezuela)

    1995-02-01

    A literature review of four in situ combustion projects: in Miga, Tia Juana, Melones and Morichal fields in Venezuela was made, and a summary of these projects is presented. Reservoir description and project performance data were analyzed. The behavior of the four in situ combustion field tests can be summarized as follows: The problems most often encountered were corrosion and high temperature producing wells. The direction in which the burning front moved was guided essentially by reservoir characteristics. The produced oil was upgraded by about 4{degrees} API, and viscosity was substantially reduced. For Mirochal and Miga fields, the analyses of available information from the combustion projects indicated that the process has been successful in the affected region. Conclusions from this review indicate that the two most frequent problems encountered were operational problems in producing wells and the direction of the burning front. The heterogeneous nature of the sands probably resulted in the burning front moving in a preferential direction, hence reducing areal sweep efficiency.

  4. An in situ study of resin-assisted solvothermal metal-organic framework synthesis

    Science.gov (United States)

    Moorhouse, Saul J.; Wu, Yue; O'Hare, Dermot

    2016-04-01

    A newly developed in situ monochromatic high-energy X-ray diffraction setup was used to investigate the synthesis of MOFs using cation-impregnated polymer resin beads as a ion source. The Co-NDC-DMF (NDC=2,6-naphthalenedicarboxylate; DMF=dimethylformamide) system was investigated, a system which is known to produce at least three distinct frameworks. It was found that the resin-assisted synthesis results in the preferential formation of a topology previously impossible to synthesise in bulk, while the comparable nitrate-salt synthesis appeared to form an alternative phases. It was also found that the resin-assisted synthesis is highly diffusion-controlled.

  5. Characterization of the in situ ecophysiology of novel phylotypes in nutrient removal activated sludge treatment plants

    DEFF Research Database (Denmark)

    McIlroy, Simon Jon; Awata, Takanori; Nierychlo, Marta

    2015-01-01

    An in depth understanding of the ecology of activated sludge nutrient removal wastewater treatment systems requires detailed knowledge of the community composition and metabolic activities of individual members. Recent 16S rRNA gene amplicon surveys of activated sludge wastewater treatment plants...... with nutrient removal indicate the presence of a core set of bacterial genera. These organisms are likely responsible for the bulk of nutrient transformations underpinning the functions of these plants. While the basic activities of some of these genera in situ are known, there is little to no information...

  6. Sphingomyelinase D activity in model membranes: structural effects of in situ generation of ceramide-1-phosphate

    DEFF Research Database (Denmark)

    Stock, Roberto; Brewer, Jonathan R.; Wagner, Kerstin;

    2012-01-01

    The toxicity of Loxosceles spider venom has been attributed to a rare enzyme, sphingomyelinase D, which transforms sphingomyelin to ceramide-1-phosphate. The bases of its inflammatory and dermonecrotic activity, however, remain unclear. In this work the effects of ceramide-1-phosphate on model...... membranes were studied both by in situ generation of this lipid using a recombinant sphingomyelinase D from the spider Loxosceles laeta and by pre-mixing it with sphingomyelin and cholesterol. The systems of choice were large unilamellar vesicles for bulk studies (enzyme kinetics, fluorescence spectroscopy...

  7. In Situ Chemical Characterization of Mineral Phases in Lunar Granulite Meteorite Northwest Africa 5744

    Science.gov (United States)

    Kent, J. J.; Brandon, A. D.; Lapen, T. J.; Peslier, A. H.; Irving, A. J.; Coleff, D. M.

    2012-01-01

    Northwest Africa (NWA) 5744 meteorite is a granulitic and troctolitic lunar breccia which may represent nearly pristine lunar crust (Fig. 1). NWA 5744 is unusually magnesian compared to other lunar breccias, with bulk [Mg/(Mg+Fe)] 0.79 [1, 2]. Inspection shows impactor content is likely to be very minor, with low Ni content and a lack of metal grains. Some terrestrial contamination is present, evidenced by calcite within cracks. NWA 5744 has notably low concentrations of incompatible trace elements (ITEs) [2]. The goal of this study is to attempt to classify this lunar granulite through analyses of in situ phases.

  8. Artificial solid electrolyte interphase with in-situ formed porosity for enhancing lithiation of silicon wafer

    Science.gov (United States)

    Lin, Jie; Guo, Jianlai; Liu, Chang; Guo, Hang

    2016-12-01

    In order to utilize silicon wafer as electrode and substrate for integrated lithium-ion batteries, a composite film with in-situ formed porosity (lithium phosphorous oxynitride/tin oxide, LiPON/SnO2) is fabricated and directly exploited as the artificial solid electrolyte interphase film. Without the compromise of Coulombic efficiency, the capacity and cycle performance of silicon wafer are both developed, resulting from the reduced resistance and the dynamically stable coating. This work provides guidance to enhance the lithiation of bulk silicon, and the strategy of surface modification can be applied to other advanced materials or fields.

  9. The effect of strain path change on subgrain volume fraction determined from in situ X-ray measurements

    DEFF Research Database (Denmark)

    Wejdemann, Christian; Poulsen, Henning Friis; Lienert, U.;

    2009-01-01

    The evolution of dislocation structures in individual bulk grains in copper during strain path changes is studied with a new in situ synchrotron technique which combines high angular resolution with fast three-dimensional reciprocal space mapping. Deformed copper contains regions with vanishing...... dislocation density called subgrains bounded by dislocation rich walls. With the new technique reciprocal space maps, consisting of sharp peaks arising from the subgrains superimposed on a cloud of lower intensity arising from the dislocation walls, are obtained, which allows properties such as subgrain...... to additional 5% strain is performed in situ while mapping a selected X-ray reflection from one particular bulk grain with high angular resolution. The reciprocal space maps are analyzed with a recently developed fitting method, and a correlation is found between the evolution of the subgrain volume fraction...

  10. Alternatieve in situ bodemsaneringstechnieken; literatuuronderzoek bij het project "In Situ Biorestauratie" Asten

    NARCIS (Netherlands)

    Scheuter AJ; LBG

    1997-01-01

    In developing in situ remediation most of the focus used to be on techniques using infiltration water to supply oxygen to the location. Later, techniques were developed in which soil was flushed with air to enhance the oxygen availability to microorganisms. The aim of the study reported here was to

  11. In situ oxygen conditioning of /001/ MgO thin film substrates for film growth studies by electron microscopy

    Science.gov (United States)

    Moorhead, R. D.; Poppa, H.

    1979-01-01

    It was found that the in situ treatment of 001-plane single-crystal films of MgO (prepared by epitaxial growth from the vapor phase) at high temperatures with a jet of oxygen will produce a surface that is almost equivalent, for epitaxial studies, to surfaces with the same orientation prepared by vacuum cleavage of bulk single crystals. The effectiveness of the process is demonstrated by its impact on the epitaxy of silver.

  12. DUCTAL CARCINOMA IN SITU OF THE BREAST

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To investigate the clinical characteristics, treatment and prognosis of ductal carcinoma in situ (DCIS) of the breast. Methods: Clinicopathological and follow-up data were collected in 52 patients with DCIS. Results: The clinic data showed that 50 patients had signs of breast lumps or/and nipple discharges, 2 patients presented abnormal mammography; 2 patients had lymph node involved; and 14 patients were accompanied with intraductal papillomatosis. All patients were Received surgical therapy. The follow-up data showed 1 patient locally recurred after lumpectomy, and was underwent mastectomy again, then cured. There were no patients died of DCIS. Conclusion: Mastectomy should be a standard surgical mode, and the prognosis of DCIS was favorable, but mammography for screening of asymptomatic women should be strengthened to find DCIS.

  13. IN SITU URANIUM STABILIZATION BY MICROBIAL METABOLITES

    Energy Technology Data Exchange (ETDEWEB)

    Turick, C; Anna Knox, A; Chad L Leverette,C; Yianne Kritzas, Y

    2006-11-29

    Soil contaminated with U was the focus of this study in order to develop in-situ, U bio-immobilization technology. We have demonstrated microbial production of a metal chelating biopolymer, pyomelanin, in U contaminated soil from the Tims Branch area of the Department of Energy (DOE) Savannah River Site (SRS) as a result of tyrosine amendments. Bacterial densities of pyomelanin producers were >106 cells/g wet soil. Pyomelanin demonstrated U chelating and mineral binding capacities at pH 4 and 7. In laboratory studies, in the presence of goethite or illite, pyomelanin enhanced U sequestration by these minerals. Tyrosine amended soils in field tests demonstrated increased U sequestration capacity following pyomelanin production up to 13 months after tyrosine treatments.

  14. In-situ trainable intrusion detection system

    Energy Technology Data Exchange (ETDEWEB)

    Symons, Christopher T.; Beaver, Justin M.; Gillen, Rob; Potok, Thomas E.

    2016-11-15

    A computer implemented method detects intrusions using a computer by analyzing network traffic. The method includes a semi-supervised learning module connected to a network node. The learning module uses labeled and unlabeled data to train a semi-supervised machine learning sensor. The method records events that include a feature set made up of unauthorized intrusions and benign computer requests. The method identifies at least some of the benign computer requests that occur during the recording of the events while treating the remainder of the data as unlabeled. The method trains the semi-supervised learning module at the network node in-situ, such that the semi-supervised learning modules may identify malicious traffic without relying on specific rules, signatures, or anomaly detection.

  15. In-situ SEM electrochemistry and radiolysis

    DEFF Research Database (Denmark)

    Møller-Nilsen, Rolf Erling Robberstad; Norby, Poul

    Electron microscopy is a ubiquitous technique to see effects which are too small to see with traditional optical microscopes. Recently it has become possible to also image liquid samples by encapsulating them from the vacuum of the microscope and a natural evolution from that has been to include...... microelectrodes on the windows to enable studies of electrohcemical processes. In this way it is possible to perform in-situ electrochemical experiments such as electroplating and charge and discharge analysis of battery electrodes. In a typical liquid cell, electrons are accelerated to sufficiently high energies...... to traverse a thin window made by a silicon nitride membrane, and interact with the sample immersed in liquid. In transmission electron microscopy (TEM) the majority of the electrons continue through the sample to form an image. In scanning electron microscopy (SEM) a fraction of the electrons...

  16. Overview of In - Situ Biodegradation and Enhancement

    Institute of Scientific and Technical Information of China (English)

    DONG Jun; Anthony ADZOMANI; ZHAO Yongsheng

    2002-01-01

    Microbial degradation technologies have been developed to restore ground water quality in aquifers polluted by organic contaminants effectively in recent years. However, in course of the degradation, the formation of biofilms in ground water remediation technology can be detrimental to the effectiveness of a ground water remediation project. Several alternatives are available to a remedial design engineer, such as Permeable Reactive Barriers (PRBs) and in -situ bioremediation, Hydrogen Releasing Compounds (HRCs) barrier, Oxygen Releasing Compounds (ORCs) barrier etc. which are efficient and cost- effective technologies. Excessive biomass formation renders a barrier ineffective in degrading the contaminants, Efforts are made to develop kinetics models which accurately determine bio - fouling and bio - filn formation and to control excessive biomass formation.

  17. Support Routines for In Situ Image Processing

    Science.gov (United States)

    Deen, Robert G.; Pariser, Oleg; Yeates, Matthew C.; Lee, Hyun H.; Lorre, Jean

    2013-01-01

    This software consists of a set of application programs that support ground-based image processing for in situ missions. These programs represent a collection of utility routines that perform miscellaneous functions in the context of the ground data system. Each one fulfills some specific need as determined via operational experience. The most unique aspect to these programs is that they are integrated into the large, in situ image processing system via the PIG (Planetary Image Geometry) library. They work directly with space in situ data, understanding the appropriate image meta-data fields and updating them properly. The programs themselves are completely multimission; all mission dependencies are handled by PIG. This suite of programs consists of: (1)marscahv: Generates a linearized, epi-polar aligned image given a stereo pair of images. These images are optimized for 1-D stereo correlations, (2) marscheckcm: Compares the camera model in an image label with one derived via kinematics modeling on the ground, (3) marschkovl: Checks the overlaps between a list of images in order to determine which might be stereo pairs. This is useful for non-traditional stereo images like long-baseline or those from an articulating arm camera, (4) marscoordtrans: Translates mosaic coordinates from one form into another, (5) marsdispcompare: Checks a Left Right stereo disparity image against a Right Left disparity image to ensure they are consistent with each other, (6) marsdispwarp: Takes one image of a stereo pair and warps it through a disparity map to create a synthetic opposite- eye image. For example, a right eye image could be transformed to look like it was taken from the left eye via this program, (7) marsfidfinder: Finds fiducial markers in an image by projecting their approximate location and then using correlation to locate the markers to subpixel accuracy. These fiducial markets are small targets attached to the spacecraft surface. This helps verify, or improve, the

  18. Fungal biodegradation of phthalate plasticizer in situ.

    Science.gov (United States)

    Pradeep, S; Faseela, P; Josh, M K Sarath; Balachandran, S; Devi, R Sudha; Benjamin, Sailas

    2013-04-01

    This unique study describes how Aspergillus japonicus, Penicillium brocae and Purpureocillium lilacinum, three novel isolates of our laboratory from heavily plastics-contaminated soil completely utilized the plasticizer di(2-ethylhexyl)phthalate (DEHP) bound to PVC blood storage bags (BB) in simple basal salt medium (BSM) by static submerged growth (28 °C). Initial quantification as well as percentage utilization of DEHP blended to BB were estimated periodically by extracting it into n-hexane. A two-stage cultivation strategy was employed for the complete mycoremediation of DEHP from BB in situ. During the first growth stage, about two-third parts of total (33.5% w/w) DEHP bound to BB were utilized in two weeks, accompanied by increased fungal biomass (~0.15-0.32 g per g BB) and sharp declining (to ~3) of initial pH (7.2). At this stagnant growth state (low pH), spent medium was replaced by fresh BSM (pH, 7.2), and thus in the second stage the remaining DEHP (one-third) in BB was utilized completely. The ditches and furrows seen from the topology of the BB as seen by the 3D AFM image further confirmed the bioremediation of DEHP physically bound to BB in situ. Of the three mycelial fungi employed, P. lilacinum independently showed highest efficiency for the complete utilization of DEHP bound to BB, whose activity was comparable to that of the consortium comprising all the three fungi described herein. To sum up, the two-stage cultivation strategy demonstrated in this study shows that a batch process would efficiently remediate the phthalic acid esters blended in plastics on a large scale, and thus it offers potentials for the management of plastics wastes.

  19. In Situ Field Testing of Processes

    Energy Technology Data Exchange (ETDEWEB)

    J. Wang

    2001-12-14

    The purpose of this Analysis/Model Report (AMR) is to update and document the data and subsequent analyses from ambient field-testing activities performed in underground drifts of the Yucca Mountain Site Characterization Project (YMP). This revision updates data and analyses presented in the initial issue of this AMR. This AMR was developed in accordance with the ''Technical Work Plan for Unsaturated Zone (UZ) Flow and Transport Process Model Report'' and ''Technical Work Plan for UZ Flow, Transport, and Coupled Processes Process Model Report. These activities were performed to investigate in situ flow and transport processes. The evaluations provide the necessary framework to: (1) refine and confirm the conceptual model of matrix and fracture processes in the unsaturated zone (UZ) and (2) analyze the impact of excavation (including use of construction water and effect of ventilation) on the UZ flow and transport processes. This AMR is intended to support revisions to ''Conceptual and Numerical Models for UZ Flow and Transport'' and ''Unsaturated Zone Flow and Transport Model Process Model Report''. In general, the results discussed in this AMR are from studies conducted using a combination or a subset of the following three approaches: (1) air-injection tests, (2) liquid-release tests, and (3) moisture monitoring using in-drift sensors or in-borehole sensors, to evaluate the impact of excavation, ventilation, and construction-water usage on the surrounding rocks. The liquid-release tests and air-injection tests provide an evaluation of in situ fracture flow and the competing processes of matrix imbibition. Only the findings from testing and data not covered in the ''Seepage Calibration Model and Seepage Testing Data'' are analyzed in detail in the AMR.

  20. In-situ gelling polymers for biomedical applications

    CERN Document Server

    2015-01-01

    This book presents the research involving in situ gelling polymers and can be used as a guidebook for academics, industrialists and postgraduates interested in this area. This work summaries the academic contributions from the top authorities in the field and explore the fundamental principles of in situ gelling polymeric networks, along with examples of their major applications. This book aims to provide an up-to-date resource of in situ gelling polymer research.

  1. TEM in situ micropillar compression tests of ion irradiated oxide dispersion strengthened alloy

    Science.gov (United States)

    Yano, K. H.; Swenson, M. J.; Wu, Y.; Wharry, J. P.

    2017-01-01

    The growing role of charged particle irradiation in the evaluation of nuclear reactor candidate materials requires the development of novel methods to assess mechanical properties in near-surface irradiation damage layers just a few micrometers thick. In situ transmission electron microscopic (TEM) mechanical testing is one such promising method. In this work, microcompression pillars are fabricated from a Fe2+ ion irradiated bulk specimen of a model Fe-9%Cr oxide dispersion strengthened (ODS) alloy. Yield strengths measured directly from TEM in situ compression tests are within expected values, and are consistent with predictions based on the irradiated microstructure. Measured elastic modulus values, once adjusted for the amount of deformation and deflection in the base material, are also within the expected range. A pillar size effect is only observed in samples with minimum dimension ≤100 nm due to the low inter-obstacle spacing in the as received and irradiated material. TEM in situ micropillar compression tests hold great promise for quantitatively determining mechanical properties of shallow ion-irradiated layers.

  2. In situ fluid typing and quantification with 1D and 2D NMR logging.

    Science.gov (United States)

    Sun, Boqin

    2007-05-01

    In situ nuclear magnetic resonance (NMR) fluid typing has recently gained momentum due to data acquisition and inversion algorithm enhancement of NMR logging tools. T(2) distributions derived from NMR logging contain information on bulk fluids and pore size distributions. However, the accuracy of fluid typing is greatly overshadowed by the overlap between T(2) peaks arising from different fluids with similar apparent T(2) relaxation times. Nevertheless, the shapes of T(2) distributions from different fluid components are often different and can be predetermined. Inversion with predetermined T(2) distributions allows us to perform fluid component decomposition to yield individual fluid volume ratios. Another effective method for in situ fluid typing is two-dimensional (2D) NMR logging, which results in proton population distribution as a function of T(2) relaxation time and fluid diffusion coefficient (or T(1) relaxation time). Since diffusion coefficients (or T(1) relaxation time) for different fluid components can be very different, it is relatively easy to separate oil (especially heavy oil) from water signal in a 2D NMR map and to perform accurate fluid typing. Combining NMR logging with resistivity and/or neutron/density logs provides a third method for in situ fluid typing. We shall describe these techniques with field examples.

  3. Determination of the initial oxidation behavior of Zircaloy-4 by in-situ TEM

    Science.gov (United States)

    Harlow, Wayne; Ghassemi, Hessam; Taheri, Mitra L.

    2016-06-01

    The corrosion behavior of Zircaloy-4 (Zry-4), specifically by oxidation, is a problem of great importance as this material is critical for current nuclear reactor cladding. The early formation behavior and structure of the oxide layer during oxidation was studied using in-situ TEM techniques that allowed for Zry-4 to be monitored during corrosion. These environmental exposure experiments were coupled with precession electron diffraction to identify and quantify the phases present in the samples before and after the oxidation. Following short-term, high temperature oxidation, the dominant phase was revealed to be monoclinic ZrO2 in a columnar structure. These samples oxidized in-situ contained structures that correlated well with bulk Zry-4 subjected to autoclave treatment, which were used for comparison and validation of this technique. By using in-situ TEM the effect of microstructure features, such as grain boundaries, on oxidation behavior of an alloy can be studied. The technique presented herein holds the potential to be applied any alloy system to study these effects.

  4. Ultrafast laser processing of transparent materials supported by in-situ diagnostics

    Science.gov (United States)

    Kumkar, M.; Kaiser, M.; Kleiner, J.; Grossmann, D.; Flamm, D.; Bergner, K.; Nolte, S.

    2016-03-01

    For the development of industrial NIR ultrafast laser processing of transparent materials, the absorption inside the bulk material has to be controlled. Applications we aim for are front and rear side ablation, drilling and inscription of modifications for cleaving and selective laser etching of glass and sapphire in sheet geometry. We applied pump probe technology and in situ stress birefringence microscopy for fundamental studies on the influence of energy and duration (100 fs - 20 ps), temporal and spatial spacing, focusing and beam shaping of the laser pulses. Applying pump probe technique we are able to visualize differences of spatio-temporal build up of absorption, self focusing, shock wave generation for standard, multispot and beam shaped focusing. Incubation effects and disturbance of beam propagation due to modifications or ablation can be observed. In-situ imaging of stress birefringence gained insight in transient build up of stress with and without translation. The results achieved so far, demonstrate that transient stress has to be taken into account in scaling the laser machining throughput of brittle materials. Furthermore it points out that transient stress birefringence is a good indicator for accumulation effects, supporting tailored processing strategies. Cutting results achieved for selective laser etching by single pass laser modification exemplifies the benefits of process development supported by in situ diagnostics.

  5. A review of in-situ EBSD experiments

    Institute of Scientific and Technical Information of China (English)

    Stuart I. WRIGHT; Matthew M. NOWELL

    2005-01-01

    Automated EBSD or Orientation Imaging Microscopy (OIM) systems are being used in combination with other equipment within the scanning electron microscope (SEM) to perform in-situ measurements. This paper briefly reviews OIM studies of in-situ experiments performed using tensile and heating stages as well as in-situ serial sectioning. In particular, in-situ OIM scan results on an aluminum alloy sample deformed in tension; phase transformations in a cobalt sample, recrystallization and grain growth in a copper sample and serial sectioning of a nickel super-alloy sample are reviewed.

  6. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Havndrup-Pedersen, Cæcilie; Honoré, Daniel;

    2015-01-01

    the restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization...... for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and three low......-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low-viscosity bulk...

  7. The Incredible Bulk

    CERN Document Server

    Fukushima, Keita; Kumar, Jason; Sandick, Pearl; Yamamoto, Takahiro

    2014-01-01

    Recent experimental results from the LHC have placed strong constraints on the masses of colored superpartners. The MSSM parameter space is also constrained by the measurement of the Higgs boson mass, and the requirement that the relic density of lightest neutralinos be consistent with observations. Although large regions of the MSSM parameter space can be excluded by these combined bounds, leptophilic versions of the MSSM can survive these constraints. In this paper we consider a scenario in which the requirements of minimal flavor violation, vanishing $CP$-violation, and mass universality are relaxed, specifically focusing on scenarios with light sleptons. We find a large region of parameter space, analogous to the original bulk region, for which the lightest neutralino is a thermal relic with an abundance consistent with that of dark matter. We find that these leptophilic models are constrained by measurements of the magnetic and electric dipole moments of the electron and muon, and that these models have ...

  8. Creating bulk nanocrystalline metal.

    Energy Technology Data Exchange (ETDEWEB)

    Fredenburg, D. Anthony (Georgia Institute of Technology, Atlanta, GA); Saldana, Christopher J. (Purdue University, West Lafayette, IN); Gill, David D.; Hall, Aaron Christopher; Roemer, Timothy John (Ktech Corporation, Albuquerque, NM); Vogler, Tracy John; Yang, Pin

    2008-10-01

    Nanocrystalline and nanostructured materials offer unique microstructure-dependent properties that are superior to coarse-grained materials. These materials have been shown to have very high hardness, strength, and wear resistance. However, most current methods of producing nanostructured materials in weapons-relevant materials create powdered metal that must be consolidated into bulk form to be useful. Conventional consolidation methods are not appropriate due to the need to maintain the nanocrystalline structure. This research investigated new ways of creating nanocrystalline material, new methods of consolidating nanocrystalline material, and an analysis of these different methods of creation and consolidation to evaluate their applicability to mesoscale weapons applications where part features are often under 100 {micro}m wide and the material's microstructure must be very small to give homogeneous properties across the feature.

  9. Explosive bulk charge

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Jacob Lee

    2015-04-21

    An explosive bulk charge, including: a first contact surface configured to be selectively disposed substantially adjacent to a structure or material; a second end surface configured to selectively receive a detonator; and a curvilinear side surface joining the first contact surface and the second end surface. The first contact surface, the second end surface, and the curvilinear side surface form a bi-truncated hemispherical structure. The first contact surface, the second end surface, and the curvilinear side surface are formed from an explosive material. Optionally, the first contact surface and the second end surface each have a substantially circular shape. Optionally, the first contact surface and the second end surface consist of planar structures that are aligned substantially parallel or slightly tilted with respect to one another. The curvilinear side surface has one of a smooth curved geometry, an elliptical geometry, and a parabolic geometry.

  10. Elastic Moduli Inheritance and Weakest Link in Bulk Metallic Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Stoica, Alexandru Dan [ORNL; Wang, Xun-Li [ORNL; Lu, Z.P. [University of Science and Technology, Beijing; Clausen, Bjorn [Los Alamos National Laboratory (LANL); Brown, Donald [Los Alamos National Laboratory (LANL)

    2012-01-01

    We show that a variety of bulk metallic glasses (BMGs) inherit their Young s modulus and shear modulus from the solvent components. This is attributed to preferential straining of locally solvent-rich configurations among tightly bonded atomic clusters, which constitute the weakest link in an amorphous structure. This aspect of inhomogeneous deformation, also revealed by our in-situ neutron diffraction studies of an elastically deformed BMG, suggests a scenario of rubber-like viscoelasticity owing to a hierarchy of atomic bonds in BMGs.

  11. Preparation of Cu-based Bulk Metallic Glass Matrix Composites

    Institute of Scientific and Technical Information of China (English)

    Yufeng SUN; Yuren WANG; Bingchen WEI; Weihuo LI

    2006-01-01

    Cu47Ti34Zr11Ni8 bulk metallic glass (BMG) matrix composites containing in situ formed TiC particles and δ-TiCu dendrite phase were developed by copper mold cast. The thermal stability and microstructure of the composites are investigated. Room temperature compression tests reveal that the composite samples exhibit higher fracture strength and distinct plastic strain of 0.2%~0.5%, comparing with that of the corresponding Cu47Ti34Zr11 Ni8 monolithic BMG.

  12. Ultraviolet-visible bulk optical properties of randomly distributed soot.

    Science.gov (United States)

    Renard, J B; Hadamcik, E; Brogniez, C; Berthet, G; Worms, J C; Chartier, M; Pirre, M; Ovarlez, J; Ovarlez, H

    2001-12-20

    The presence of soot in the lower stratosphere was recently established by in situ measurements. To isolate their contribution to optical measurements from that of background aerosol, the soot's bulk optical properties must be determined. Laboratory measurements of extinction and polarization of randomly distributed soot were conducted. For all soot, measurements show a slight reddening extinction between 400 and 700 nm and exhibit a maximum of 100% polarization at a scattering angle of 75 +/- 5 degrees. Such results cannot be reproduced by use of Mie theory assumptions. The different optical properties of soot and background stratospheric aerosol could allow isolation of soot in future analyses of stratospheric measurements.

  13. Calibration and study of the measurement capabilities of real-time gamma spectrometry equipment developed for the renewal of the network of stations automatic monitoring environmental radiation of the Generalitat of Catalunya; Calibracion y estudio de las capacidades de medida de los equipos de espectrometria gamma en tiempo real desarrollados para la renovacion de la Red de Estaciones Automaticas de vigilancia radiologia ambiental de la Generalitat de Catalunya

    Energy Technology Data Exchange (ETDEWEB)

    Casanovas, R.; Prieto, E.; Salvado, M.

    2014-10-01

    The renewal of the automatic environmental radiation surveillance network of the Generalitat of Catalunya has been carried out through the development and implementation of gamma-spectrometry-based equipment. the monitors use scintillation crystals, either Na(TI) or LaBr{sub 3}(Ce) and currently, there are 3 types of equipment water radioactivity monitors, aerosols on a particulate filter monitors and direct measurement monitors. In this paper, we expose the basic features of its operation, the details of their calibration and the minimum detectable activity concentration for some isotopes. (Author)

  14. Calibration and study of the measurement capabilities of real-time gamma spectrometry equipment, developed for the renewal of the network of automatic stations for environmental radiological surveillance of the Generalitat de Catalunya; Calibracion y estudio de las capacidades de medida de loes equipos de espectrometria gamma en tiempo real desarrollados para la renovacion de la Red de Estaciones Automaticas de vigencia radiologica ambiental de la generalitat de Catalunya

    Energy Technology Data Exchange (ETDEWEB)

    Casanovas, R.; Prieto, E.; Salvado, M.

    2013-07-01

    The renewal of the automatic environmental radiation surveillance network of the Gereralitat of Catalunya has been carried out through the development and implementation of gamma-spectrometry-based equipment. The monitors use scintillation cristals, either NaI(Tl) or LaBr{sub 3}(Ce) and currently, there are 3 types of equipment: water radioactivity monitors, aerosols on a particulate filter monitors and direct measurement monitors. In this paper, we expose the basic features of its operation, the details of their calibration and the minimum detectable activity concentrations for some isotopes.

  15. Melanoma "in situ" tratado con Imiquimod Melanoma in situ treated with Imiquimod

    Directory of Open Access Journals (Sweden)

    RE Achenbach

    Full Text Available Comunicamos un caso con dos melanomas "in situ", en un varón de 86 años, localizados en ambos lados de la cara con alto riesgo quirúrgico, quien fuera tratado con imiquimod al 5% una vez al día durante dos meses; los resultados hasta el momento, clínicos e histológicos han sido satisfactorios.A 86 years-old man with two melanomas "in situ" at both sides of his face, treated with imiquimod 5% are presented. The patient has a cardiovascular high risk due to isquemic heart disease, for that reason we start the treatment with imiquimod once a day for two months. The clinical and histological response was good and a follow up will be as long as we can.

  16. In situ observations from STEREO/PLASTIC: a test for L5 space weather monitors

    Directory of Open Access Journals (Sweden)

    K. D. C. Simunac

    2009-10-01

    Full Text Available Stream interaction regions (SIRs that corotate with the Sun (corotating interaction regions, or CIRs are known to cause recurrent geomagnetic storms. The Earth's L5 Lagrange point, separated from the Earth by 60 degrees in heliographic longitude, is a logical location for a solar wind monitor – nearly all SIRs/CIRs will be observed at L5 several days prior to their arrival at Earth. Because the Sun's heliographic equator is tilted about 7 degrees with respect to the ecliptic plane, the separation in heliographic latitude between L5 and Earth can be more than 5 degrees. In July 2008, during the period of minimal solar activity at the end of solar cycle 23, the two STEREO observatories were separated by about 60 degrees in longitude and more than 4 degrees in heliographic latitude. This time period affords a timely test for the practical application of a solar wind monitor at L5. We compare in situ observations from PLASTIC/AHEAD and PLASTIC/BEHIND, and report on how well the BEHIND data can be used as a forecasting tool for in situ conditions at the AHEAD spacecraft with the assumptions of ideal corotation and minimal source evolution. Preliminary results show the bulk proton parameters (density and bulk speed are not in quantitative agreement from one observatory to the next, but the qualitative profiles are similar.

  17. In situ X-ray investigations of oxygen precipitation in semiconductor silicon; In-situ-Roentgenuntersuchungen der Sauerstoffpraezipitation in Halbleitersilizium

    Energy Technology Data Exchange (ETDEWEB)

    Grillenberger, Hannes

    2011-03-04

    The precipitation of oxygen in Czochralski grown semiconductor silicon is investigated in situ during thermal treatments up to 1000 C with high energy X-rays. All investigations are performed with a focusing Laue diffractometer. The parameters of the diffraction curve are the relative full width at half maximum (rFHWM) and the enhancement of the integral intensity (EII). A readout software has been developed to extract these automatically from the detector image for the measured 220, -220 and 040 Bragg peaks. The sample thickness is set to 15 mm as this enhances the sensitivity of the method and the samples are processed after the strain-field diffraction (SFD) experiments to wafers for an ex situ characterization demanding wafers. Three experimental series with a total of 21 in situ SFD experiments with different thermal treatments have been performed. The slope of the initial temperature ramp is set to 1 K/min in the first and the third series to generate a high precipitate (Bulk Micro Defect, BMD) density. In the second series the slope is chosen as 10 K/min to generate a lower density in the same silicon material. It is shown with all experiments and with preliminary works that the built up of strain during the heat treatment is caused by BMDs during the high temperature period of the treatment. The detection limit of series 1 is found at 7 nm at a density of 10{sup 13}/cm{sup 3}, of series 2 at 40 nm at a density of 2 x 10{sup 8}/cm{sup 3}, and at 8 nm at a density of 4.8 x 10{sup 12}/cm{sup 3} for series 3. The local maximum of the EII at 450 C, which emerges coincident with a local minimum of the rFWHM in series 2 may be caused by thermal donors (TD). With the experiments is shown that SFD operates in the infrared-laser scattering tomography detection range, but also reaches in a region covered only by transmission electron microscopy (TEM) so far. In contrast to these methods SFD is not limited to low temperatures and in situ experiments can be done. Thus

  18. Chromogenic in situ hybridization: a multicenter study comparing silver in situ hybridization with FISH.

    Science.gov (United States)

    Bartlett, J M S; Campbell, Fiona M; Ibrahim, Merdol; Wencyk, Peter; Ellis, Ian; Kay, Elaine; Connolly, Yvonne; O'Grady, Anthony; Di Palma, Silvana; Starczynski, Jane; Morgan, John M; Jasani, Bharat; Miller, Keith

    2009-10-01

    Our purposes were to perform a robust assessment of a new HER2 chromogenic in situ hybridization test and report on concordance of silver in situ hybridization (SISH) data with fluorescence in situ hybridization (FISH) data and on intraobserver and interlaboratory scoring consistency. HER2 results were scored from 45 breast cancers in 7 laboratories using the Ventana (Tucson, AZ) INFORM HER-2 SISH assay and in 1 central laboratory using a standard FISH assay. Overall, 94.8% of cases were successfully analyzed by SISH across the 6 participating laboratories that reported data. Concordance for diagnosis of HER2 amplification by SISH compared with FISH was high (96.0% overall). Intraobserver variability (8.0%) and intersite variability (12.66%) of absolute HER2/chromosome 17 ratios appear to be tightly controlled across all 6 participating laboratories. The Ventana INFORM HER-2 SISH assay is robust and reproducible, shows good concordance with a standard FISH assay, and complies with requirements in national guidelines for performance of diagnostic tests.

  19. In Situ Observations of Phase Transitions in Metastable Nickel (Carbide)/Carbon Nanocomposites

    Science.gov (United States)

    2016-01-01

    Nanocomposite thin films comprised of metastable metal carbides in a carbon matrix have a wide variety of applications ranging from hard coatings to magnetics and energy storage and conversion. While their deposition using nonequilibrium techniques is established, the understanding of the dynamic evolution of such metastable nanocomposites under thermal equilibrium conditions at elevated temperatures during processing and during device operation remains limited. Here, we investigate sputter-deposited nanocomposites of metastable nickel carbide (Ni3C) nanocrystals in an amorphous carbon (a-C) matrix during thermal postdeposition processing via complementary in situ X-ray diffractometry, in situ Raman spectroscopy, and in situ X-ray photoelectron spectroscopy. At low annealing temperatures (300 °C) we observe isothermal Ni3C decomposition into face-centered-cubic Ni and amorphous carbon, however, without changes to the initial finely structured nanocomposite morphology. Only for higher temperatures (400–800 °C) Ni-catalyzed isothermal graphitization of the amorphous carbon matrix sets in, which we link to bulk-diffusion-mediated phase separation of the nanocomposite into coarser Ni and graphite grains. Upon natural cooling, only minimal precipitation of additional carbon from the Ni is observed, showing that even for highly carbon saturated systems precipitation upon cooling can be kinetically quenched. Our findings demonstrate that phase transformations of the filler and morphology modifications of the nanocomposite can be decoupled, which is advantageous from a manufacturing perspective. Our in situ study also identifies the high carbon content of the Ni filler crystallites at all stages of processing as the key hallmark feature of such metal–carbon nanocomposites that governs their entire thermal evolution. In a wider context, we also discuss our findings with regard to the much debated potential role of metastable Ni3C as a catalyst phase in graphene and

  20. In situ silica-EPDM nanocomposites obtained via reactive processing

    NARCIS (Netherlands)

    Miloskovska, Elena; Hristova-Bogaerds, Denka; van Duin, Martin; de With, Gijsbertus

    2015-01-01

    In situ rubber nanocomposites prepared via reactive batch mixing and via reactive extrusion were studied. Materials produced via reactive batch mixing showed a significantly higher silica content for a similar reaction time as compared to previously prepared in situ nanocomposites using a diffusion

  1. In-situ tensile testing of propellant samples within SEM

    NARCIS (Netherlands)

    Benedetto, G.L. di; Ramshorst, M.C.J. van; Duvalois, W.; Hooijmeijer, P.A.; Heijden, A.E.D.M. van der; Klerk, W.P.C. de

    2015-01-01

    A tensile module system placed within a FEI NovaNanoSEM 650 Scanning Electron Microscope (SEM) was utilized in this work to conduct in-situ tensile testing of propellant material samples. This tensile module system allows for real-time in-situ SEM analysis of the samples to determine the failure mec

  2. CGS and In Situ Measurements in Gävle 1999

    DEFF Research Database (Denmark)

    Aage, Helle Karina; Korsbech, Uffe C C; Bargholz, Kim

    1999-01-01

    Calibration of CGS-equipment.In situ measuremts with HPGe-detector (and dose rate meter)in Gävle Sweden as part of the Nordic exercise RESUME99.......Calibration of CGS-equipment.In situ measuremts with HPGe-detector (and dose rate meter)in Gävle Sweden as part of the Nordic exercise RESUME99....

  3. In Situ Immobilization of Selenium in Sediment

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Robert C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stewart, Thomas Austin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    This project focused on the use of a sorbent, carbonated apatite, to immobilize selenium in the environment. It is know that apatite will sorb selenium and based on the mechanism of sorption it is theorized that carbonated apatite will be more effective that pure apatite. Immobilization of selenium in the environment is through the use of a sorbent in a permeable reactive barrier (PRB). A PRB can be constructed by trenching and backfill with the sorbent or in the case of apatite as the sorbent formed in situ using the apatite forming solution of Moore (2003, 2004). There is very little data on selenium sorption by carbonated apatite in the literature. Therefore, in this work, the basic sorptive properties of carbonated apatite were investigated. Carbonated apatite was synthesized by a precipitation method and characterized. Batch selenium kinetic and equilibrium experiments were performed. The results indicate the carbonated apatite contained 9.4% carbonate and uptake of selenium as selenite was rapid; 5 hours for complete uptake of selenium vs. more than 100 hours for pure hydroxyapatite reported in the literature. Additionally, the carbonated apatite exhibited significantly higher distribution coefficients in equilibrium experiments than pure apatite under similar experimental conditions. The next phase of this work will be to seek additional funds to continue the research with the goal of eventually demonstrating the technology in a field application.

  4. Visualizing T cell migration in-situ

    Directory of Open Access Journals (Sweden)

    Alexandre P Benechet

    2014-07-01

    Full Text Available Mounting a protective immune response is critically dependent on the orchestrated movement of cells within lymphoid tissues. The structure of secondary lymphoid organs regulates immune responses by promoting optimal cell-cell and cell-extracellular matrix interactions. Naïve T cells are initially activated by antigen presenting cells in secondary lymphoid organs. Following priming, effector T cells migrate to the site of infection to exert their functions. Majority of the effector cells die while a small population of antigen specific T cells persist as memory cells in distinct anatomical locations. The persistence and location of memory cells in lymphoid and non-lymphoid tissues is critical to protect the host from re-infection. The localization of memory T cells is carefully regulated by several factors including the highly organized secondary lymphoid structure, the cellular expression of chemokine receptors and compartmentalized secretion of their cognate ligands. This balance between the anatomy and the ordered expression of cell surface and soluble proteins regulates the subtle choreography of T cell migration. In recent years, our understanding of cellular dynamics of T cells has been advanced by the development of new imaging techniques allowing in-situ visualization of T cell responses. Here we review the past and more recent studies that have utilized sophisticated imaging technologies to investigate the migration dynamics of naive, effector and memory T cells.

  5. Cubesat in-situ degradation detector (CIDD)

    Science.gov (United States)

    Rievers, Benny; Milke, Alexander; Salden, Daniel

    2015-07-01

    The design of the thermal control and management system (TCS) is a central task in satellite design. In order to evaluate and dimensionize the properties of the TCS, material parameters specifying the conductive and radiative properties of the different TCS components have to be known including their respective variations within the mission lifetime. In particular the thermo-optical properties of the outer surfaces including critical TCS components such as radiators and thermal insulation are subject to degradation caused by interaction with the space environment. The evaluation of these material parameters by means of ground testing is a time-consuming and expensive endeavor. Long-term in-situ measurements on board the ISS or large satellites not only realize a better implementation of the influence of the space environment but also imply high costs. Motivated by this we propose the utilization of low-cost nano-satellite systems to realize material tests within space at a considerably reduced cost. We present a nanosat-scale degradation sensor concept which realizes low power consumption and data rates compatible with nanosat boundaries at UHF radio. By means of a predefined measurement and messaging cycle temperature curves are measured and evaluated on ground to extract the change of absorptivity and emissivity over mission lifetime.

  6. In situ containment and stabilization of buried waste

    Energy Technology Data Exchange (ETDEWEB)

    Allan, M.L.; Kukacka, L.E.; Heiser, J.H.

    1992-11-01

    The objective of the project was to develop, demonstrate and implement advanced grouting materials for the in-situ installation of impermeable, durable subsurface barriers and caps around waste sites and for the in-situ stabilization of contaminated soils. Specifically, the work was aimed at remediation of the Chemical Waste (CWL) and Mixed Waste Landfills (MWL) at Sandia National Laboratories (SNL) as part of the Mixed Waste Landfill Integrated Demonstration (MWLID). This report documents this project, which was conducted in two subtasks. These were (1) Capping and Barrier Grouts, and (2) In-situ Stabilization of Contaminated Soils. Subtask 1 examined materials and placement methods for in-situ containment of contaminated sites by subsurface barriers and surface caps. In Subtask 2 materials and techniques were evaluated for in-situ chemical stabilization of chromium in soil.

  7. In situ chemical functionalization of gallium nitride with phosphonic acid derivatives during etching.

    Science.gov (United States)

    Wilkins, Stewart J; Greenough, Michelle; Arellano, Consuelo; Paskova, Tania; Ivanisevic, Albena

    2014-03-04

    In situ functionalization of polar (c plane) and nonpolar (a plane) gallium nitride (GaN) was performed by adding (3-bromopropyl) phosphonic acid or propyl phosphonic acid to a phosphoric acid etch. The target was to modulate the emission properties and oxide formation of GaN, which was explored through surface characterization with atomic force microscopy, X-ray photoelectron spectroscopy, photoluminescence (PL), inductively coupled plasma-mass spectrometry, and water contact angle. The use of (3-bromopropyl) phosphonic acid and propyl phosphonic acid in phosphoric acid demonstrated lower amounts of gallium oxide formation and greater hydrophobicity for both sample sets, while also improving PL emission of polar GaN samples. In addition to crystal orientation, growth-related factors such as defect density in bulk GaN versus thin GaN films residing on sapphire substrates were investigated as well as their responses to in situ functionalization. Thin nonpolar GaN layers were the most sensitive to etching treatments due in part to higher defect densities (stacking faults and threading dislocations), which accounts for large surface depressions. High-quality GaN (both free-standing bulk polar and bulk nonpolar) demonstrated increased sensitivity to oxide formation. Room-temperature PL stands out as an excellent technique to identify nonradiative recombination as observed in the spectra of heteroepitaxially grown GaN samples. The chemical methods applied to tune optical and physical properties of GaN provide a quantitative framework for future novel chemical and biochemical sensor development.

  8. Critical insights into the effect of shear on in situ reduction of graphene oxide in PVDF: assessing by rheo-dielectric measurements

    Science.gov (United States)

    Sharma, Maya; Madras, Giridhar; Bose, Suryasarathi

    2016-06-01

    In situ reduction of graphene oxide (GO) during the preparation of conducting polymeric nanocomposites has been explored recently. In this study, the in situ reduction of GO in poly (vinylidene fluoride) (PVDF) under different conditions like quiescent, high and low shear, pre-shear has been investigated in detail. To accomplish this, PVDF/GO composites were prepared by both melt and solution blending. The bulk electrical conductivity of melt mixed composites, which had undergone extensive shear during preparation, was monitored by a rheo-dielectric setup and compared with the composites which experienced low shear. In addition, the bulk electric conductivity was also measured in situ for the composites that had undergone quiescent compositing. Comprehensive characterization of the composites reveals that GO is in situ reducing under all processes but the improvement in conductivity is dependent on the adopted process. Compression molded samples, which were annealed for 45 min, showed highest melt conductivity among all the adopted processes. The intense shearing of composites at high temperature in melt extrusion led to re-stacking of graphene sheets and resulted in decreased bulk electrical conductivity. Surprisingly, melt conductivity decreases with shear and time in all composites. This study can help in understanding the reduction of GO during intense shearing of composites.

  9. Study of the artificial radioactivity of the marine medium using gamma spectrometry (1962-1966); Etude de la radioactivite artificielle du milieu marin par spectrometrie gamma (1962-1966)

    Energy Technology Data Exchange (ETDEWEB)

    Chesselet, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    The results described in this study are relative to the artificial radioactivity of such elements as zirconium-95, niobium-95, ruthenium-103, ruthenium-106, cerium-141, cerium-144 and praseodymium-144 which were present in the atmospheric fallout between 1962 and 1964, and their incidence in superficial marine waters. Various physical, chemical or biological processes are studied by a high sensitivity gamma ray spectrometry technic, using those radioelements as 'tracers'. The change of state in sea water of an important fraction (about 50 per cent) of the radioactive particles going into the soluble phase - this phenomenon was not expected for those radioelements - controls the processes of accumulation in the planktonic biomass and the diffusion towards deeper waters. On the other hand, an 'in situ' spectrometry method is described. It enables the direct measurement in the sea of very low concentrations of some gamma ray emitters. The application of this method has made possible to carry out numerous observations in the surface waters of the Western Mediterranean sea and in the Bay of Biscay. It is shown that the mixing depth is closely connected to the depth of the thermocline. An accumulation process at this level is observed. The diffusion coefficients are similar to the thermal turbulent coefficient. The existence during several months of 'compartments' is established for the surface waters of the Bay of Biscay. From the establishment of the budget of fall-out, a comparative study shows that the rate of radioactive fallout on the maritime zone considered is always two to three times higher than on the neighbouring continental regions. Several explanations of this phenomenon are discussed. (author) [French] Les resultats decrits dans cette etude concernent la radioactivite artificielle sous forme de zirconium-95, niobium-95, ruthenium-103, ruthenium-106, cerium-141, cerium-144 et praseodyme-144 apportee par la retombee

  10. MENDING THE IN SITU MANIPULATION BARRIER

    Energy Technology Data Exchange (ETDEWEB)

    PETERSEN, S.W.

    2006-02-06

    In early 2004, the U.S. Department of Energy (DOE) Richland and Fluor Hanford requested technical assistance from the DOE Headquarters EM-23 Technical Assistance Program to provide a team of technical experts to develop recommendations for mending the In Situ Redox Manipulation (ISRM) Barrier in the 100-D Area of the Hanford Site in Washington State. To accommodate this request, EM-23 provided support to convene a group of technical experts from industry, a national laboratory, and a DOE site to participate in a 2 1/2-day workshop with the objective of identifying and recommending options to enhance the performance of the 100-D Area reactive barrier and of a planned extension to the northeast. This report provides written documentation of the team's findings and recommendations. In 1995, a plume of dissolved hexavalent chromium [Cr(VI)], which resulted from operation of the D/DR Reactors at the Hanford site, was discovered along the Columbia River shoreline and in the 100-D Area. Between 1999 and 2003, a reactive barrier using the In Situ Redox Manipulation (ISRM) technology, was installed a distance of 680 meters along the river to reduce the Cr(VI) in the groundwater. The ISRM technology creates a treatment zone within the aquifer by injection of sodium dithionite, a strong reducing agent that scavenges dissolved oxygen (DO) from the aquifer and reduces ferric iron [Fe(III)], related metals, and oxy-ions. The reduction of Fe(III) to ferrous [Fe(II)] iron provides the primary reduction capacity to reduce Cr(VI) to the +3 state, which is less mobile and less toxic. Bench-scale and field-scale treatability tests were initially conducted to demonstrate proof-of principle and to provide data for estimation of barrier longevity. These calculations estimated barrier longevity in excess of twenty years. However, several years after initial and secondary treatment, groundwater in a number of wells has been found to contain elevated chromium (Cr) concentrations

  11. In-situ bioassays using caged bivalves

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, M.H.; Salazar, S.M.

    1995-12-31

    It is important to make the distinction between chemical measurements to assess bioaccumulation potential versus biological measurements to assess potential bioeffects because bioaccumulation is not a bioeffect. Caging provides a unique opportunity to make synoptic measurements of each and facilitates making these measurements over space and time. Measuring bioaccumulation in resident and transplanted bivalves has probably been the most frequently used form of an in-situ bioassay because bivalves concentrate chemicals in their tissues. They are also easy to collect, cage, and measure. The authors have refined bivalve bioassay methods by minimizing the size range of test animals, making repetitive measurements of the same individuals, and standardizing test protocols for a variety of applications. They are now attempting to standardize criteria for accepting and interpreting data in the same way that laboratory bioassays have been standardized. Growth measurements can serve two purposes in this assessment strategy: (1) An integrated biological response endpoint that is easily quantifiable and with significance to the population, and (2) A means of calibrating bioaccumulation by assessing the relative health and physiological state of tissues that have accumulated the chemicals. In general, the authors have found the highest bioconcentration factors associated with the highest growth rates, the highest concentrations ({micro}g/g) of chemicals in juvenile mussels, and the highest chemical content ({micro}g/animal) in adult mussels. Without accounting for possible dilution of chemical concentrations by tissue growth or magnification through degrowth, contaminant concentrations can be misleading. Examples are provided for the Sudbury River in Massachusetts (Elliptio complanata), San Diego Bay (Mytilus galloprovincialis), and the Harbor Island Superfund Site in Puget Sound (Mytilus trossulus).

  12. Ductal carcinoma in situ: a challenging disease

    Directory of Open Access Journals (Sweden)

    Sevilay Altintas

    2011-12-01

    Full Text Available Ductal carcinoma in situ (DCIS represents a heterogenous group of lesions with variable malignant potential. Although it is clearly pre-invasive, not all lesions progress to an invasive malignant disease. The significant increase in the frequency of diagnosis is the result of both widespread use of screening mammography and better recognition among pathologists. Treatment is controversial, but for several decades total mastectomy has been considered as the appropriate treatment. The tendency to be less aggressive in terms of surgery has followed the pattern of events observed in the treatment of invasive breast carcinomas. More recently, it has become clear that breastconserving procedures could be applied and selected on the basis of diagnostics and risk factors. When all patients with DCIS are considered, the overall mortality is extremely low, only about 1–2%. On the other hand, breast-conserving surgery is only curative in 75–85%; 50% of the local recurrences have proven to be invasive with a mortality rate of 12–15%. There is no place for axillary node dissection, adjuvant hormonal treatment or chemotherapy in the treatment. Important factors in predicting local recurrence are age, family history, nuclear grade, comedo-type necrosis, tumor size and margin width. With the addition of radiation therapy to excisional surgery, there is a 50% reduction in the overall local recurrence rate. The Van Nuys Prognostic Index (VNPI, recently updated, is a tool that quantifies measurable prognostic factors that can be used in the decision-making process of treatment. Recent data from large cohort studies and randomized trials have emerged to guide treatment. DCIS is now understood to have diverse malignant potential and it is unlikely that there will be a single treatment for this wide range of lesions. Advances in molecular biology and gene expression profiling of human breast tumors have been providing important insights into the relationship

  13. Retinal detachment after laser In Situ keratomileusis

    Directory of Open Access Journals (Sweden)

    Saba Al-Rashaed

    2011-01-01

    Full Text Available Purpose : To report characteristics and outcome of rhegmatogenous retinal detachment (RRD after laser in situ keratomileusis (LASIK for myopia. Materials and Methods : A retrospective chart review of patients who presented with RRD after myopic LASIK over a 10-year period. Results : Fourteen eyes were identified with RRD. Of these, two of 6112 LASIK procedures were from our center. The mean age of patients with RRD was 35.43 years. The mean interval of RRD after LASIK was 37.71 months (range, 4 months to 10 years. The macula was involved in eight eyes and spared in six eyes. Retinal breaks included a macular hole in two eyes, and giant tear in two eyes. Multiple breaks (>2 breaks occurred in 6 cases. Pars plana vitrectomy (PPV was performed in 3 (21.4% eyes, a scleral buckle (SB was performed in 4 (28.5% eyes and 7 (50% eyes underwent combined PPV and SB. Mean follow-up was 15.18 months (range, 1 month to 7 years. The retina was successfully attached in all cases. The final visual acuity was 20/40 or better in 7 (50% eyes, 20/40 to 20/60 in 4 (28.5% eyes, and 20/200 or less in 3 (21.4% eyes. Poor visual outcome was secondary to proliferative vitreoretinopathy, epiretinal membrane, macular scar and amblyopia. Conclusion : The prevalence of RRD after LASIK was low at our institute. Anatomical and visual outcomes were acceptable in eyes that were managed promptly. Although there is no cause-effect relationship between LASIK and RRD, a dilated fundus examination is highly recommended before and after LASIK for myopia.

  14. Powder metallurgy processing and deformation characteristics of bulk multimodal nickel

    Energy Technology Data Exchange (ETDEWEB)

    Farbaniec, L., E-mail: lfarban1@jhu.edu [Université Paris 13, Sorbonne Paris Cité, LSPM, CNRS, 99 Avenue J.B. Clément, 93430 Villetaneuse (France); Dirras, G., E-mail: dirras@univ-paris13.fr [Université Paris 13, Sorbonne Paris Cité, LSPM, CNRS, 99 Avenue J.B. Clément, 93430 Villetaneuse (France); Krawczynska, A.; Mompiou, F. [Université Paul Sabatier, CEMES, CNRS, 29 rue Jeanne Marvig 31055 Toulouse (France); Couque, H. [Nexter Munitions, 7 route de Guerry, 18200 Bourges (France); Naimi, F.; Bernard, F. [Institut Carnot de Bourgogne, UMR 6303 CNRS, Université de Bourgogne, BP 47870, 21078 Dijon (France); Tingaud, D. [Université Paris 13, Sorbonne Paris Cité, LSPM, CNRS, 99 Avenue J.B. Clément, 93430 Villetaneuse (France)

    2014-08-15

    Spark plasma sintering was used to process bulk nickel samples from a blend of three powder types. The resulting multimodal microstructure was made of coarse (average size ∼ 135 μm) spherical microcrystalline entities (the core) surrounded by a fine-grained matrix (average grain size ∼ 1.5 μm) or a thick rim (the shell) distinguishable from the matrix. Tensile tests revealed yield strength of ∼ 470 MPa that was accompanied by limited ductility (∼ 2.8% plastic strain). Microstructure observation after testing showed debonding at interfaces between the matrix and the coarse entities, but in many instances, shallow dimples within the rim were observed indicating local ductile events in the shell. Dislocation emission and annihilation at grain boundaries and twinning at crack tip were the main deformation mechanisms taking place within the fine-grained matrix as revealed by in-situ transmission electron microscopy. Estimation of the stress from loop's curvature and dislocation pile-up indicates that dislocation emission from grain boundaries and grain boundary overcoming largely contributes to the flow stress. - Highlights: • Bulk multi-modal Ni was processed by SPS from a powder blend. • Ultrafine-grained matrix or rim observed around spherical microcrystalline entities • Yield strength (470 MPa) and ductility (2.8% plastic strain) were measured. • Debonding was found at the matrix/microcrystalline entity interfaces. • In-situ TEM showed twinning, dislocation emission and annihilation at grain boundaries.

  15. Can bulk viscosity drive inflation

    Energy Technology Data Exchange (ETDEWEB)

    Pacher, T.; Stein-Schabes, J.A.; Turner, M.S.

    1987-09-15

    Contrary to other claims, we argue that bulk viscosity associated with the interactions of non- relativistic particles with relativistic particles around the time of the grand unified theory (GUT) phase transition cannot lead to inflation. Simply put, the key ingredient for inflation, negative pressure, cannot arise due to the bulk-viscosity effects of a weakly interacting mixture of relativistic and nonrelativistic particles.

  16. Brane Couplings from Bulk Loops

    OpenAIRE

    Georgi, Howard; Grant, Aaron K.; Hailu, Girma

    2000-01-01

    We compute loop corrections to the effective action of a field theory on a five-dimensional $S_1/Z_2$ orbifold. We find that the quantum loop effects of interactions in the bulk produce infinite contributions that require renormalization by four-dimensional couplings on the orbifold fixed planes. Thus bulk couplings give rise to renormalization group running of brane couplings.

  17. Order-disorder transformation in Fe-Pd alloy nanoparticles studied by in situ transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Kazuhisa, E-mail: ksato@imr.tohoku.ac.j [Institute of Scientific and Industrial Research, Osaka University, Ibaraki 567-0047 (Japan); Kovacs, Andras; Hirotsu, Yoshihiko [Institute of Scientific and Industrial Research, Osaka University, Ibaraki 567-0047 (Japan)

    2011-03-01

    We have studied order-disorder transformation in Fe-Pd alloy nanoparticles by in situ transmission electron microscopy (TEM) and electron diffraction. The transformation is size-dependent, and the transformation temperatures are lower than those of the bulk alloys. The transformation proceeds continuously but rather steeply as the temperature increases, which differs from the first-order transformation observed in a bulk alloy or gradual transformation predicted by simulations for nanoparticles. Experimental results indicated that the continuous nature can be attributed to the distribution of the transformation temperature due to the distributions of both particle size and alloy composition. Quantitative intensity analyses of nanobeam electron diffraction (NBD) patterns indicated the existence of short-range order (SRO) inside disordered nanoparticles. The SRO as well as particle size distribution are responsible for the remaining weak superlattice reflections above the transformation temperature. In situ high-resolution TEM (HRTEM) observation revealed the existence of the SRO, which was consistent with the results obtained by NBD. We show that the disorder may not necessarily proceed continuously from the surface toward the center of the nanoparticle. Ordering from the disordered phase upon cooling was also observed by in situ HRTEM, which can be attributed to growth of the SRO.

  18. In situ Raman spectroscopy of LiFePO4: size and morphology dependence during charge and self-discharge.

    Science.gov (United States)

    Wu, Jing; Dathar, Gopi Krishna Phani; Sun, Chunwen; Theivanayagam, Murali G; Applestone, Danielle; Dylla, Anthony G; Manthiram, Arumugam; Henkelman, Graeme; Goodenough, John B; Stevenson, Keith J

    2013-10-25

    Previous studies of the size dependent properties of LiFePO4 have focused on the diffusion rate or phase transformation pathways by bulk analysis techniques such as x-ray diffraction (XRD), neutron diffraction and electrochemistry. In this work, in situ Raman spectroscopy was used to study the surface phase change during charge and self-discharge on a more localized scale for three morphologies of LiFePO4: (1) 25 ± 6 nm width nanorods, (2) 225 ± 6 nm width nanorods and (3) ∼2 μm porous microspheres. Both the large nanorod and microsphere geometries showed incomplete delithiation at the end of charge, which was most likely caused by anti-site defects along the 1D diffusion channels in the bulk of the larger particles. Based on the in situ Raman measurements, all of the morphologies studied exhibited self-discharge with time. Among them, the smallest FePO4 particles self-discharged (lithiated) the fastest. While nanostructuring LiFePO4 can offer advantages in terms of lowering anti-site defects within particles, it also creates new problems due to high surface energies that allow self-discharge. The in situ Raman spectroscopy also showed that carbon coating did not provide significant improvement to the stability of the lithiated particles.

  19. In situ metalorganic growth control of GaAlAs thick layers using 1.32 μm laser reflectometry

    Science.gov (United States)

    Kuszelewicz, R.; Rafflé, Y.; Azoulay, R.; Dugrand, L.; Le Roux, G.

    1995-02-01

    We report on the use of in situ reflectometry using 1.32 μm laser light to monitor the metalorganic growth of thick GaAlAs layers. With respect to the particular growth conditions, the calibration of effective indices was carried out for bulk as well as multi quantum well layers. This allowed in situ measurements of large thickness layers, Al concentration determination of AlGaAS layers, and metal-semiconductor-field effect transistor (MESFET) structure monitoring with highly improved precision and reproducibility.

  20. Correlations between the in situ acoustic properties and geotechnical parameters of sediments in the Yellow Sea, China

    Science.gov (United States)

    Liu, Baohua; Han, Tongcheng; Kan, Guangming; Li, Guanbao

    2013-11-01

    Knowledge about the marine sediment acoustic properties is a key to understanding wave propagation in sediments and is very important for military oceanography and ocean engineering. We developed a hydraulic-drived self-contained in situ sediment acoustic measurement system, and measured for the first time the in situ acoustic properties of sediments on 78 stations in the Yellow Sea, China, by employing this system. The relationships between the in situ measured acoustic properties and the onboard or laboratory determined geotechnical parameters were analyzed. Porosity was found to be the dominant factor in reducing velocity in a quadratic fashion; velocity showed an increment with bulk density and a decrement with mean grain size and clay content both with a nonlinear dependence; acoustic attenuation showed a bell-shaped correlation with porosity and mean grain size but reduced with clay content of the sediments. The attenuation results indicate that intergrain friction rather than viscous interactions between pore fluid and solid grains is the dominant loss mechanism in our marine sediments. The relationships established would be used to predict the geotechnical parameters from in situ measured acoustic properties and vice versa, as well as being an indicator of the seafloor processes, potential gas bubbles hazard and gas hydrates resources or other suitable targets of acoustic surveys.

  1. NOVEL IN-SITU METAL AND MINERAL EXTRACTION TECHNOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    Glenn O' Gorman; Hans von Michaelis; Gregory J. Olson

    2004-09-22

    This white paper summarizes the state of art of in-situ leaching of metals and minerals, and describes a new technology concept employing improved fragmentation of ores underground in order to prepare the ore for more efficient in-situ leaching, combined with technology to continuously improve solution flow patterns through the ore during the leaching process. The process parameters and economic benefits of combining the new concept with chemical and biological leaching are described. A summary is provided of the next steps required to demonstrate the technology with the goal of enabling more widespread use of in-situ leaching.

  2. In Situ Probe Science at Saturn

    Science.gov (United States)

    Atkinson, D.H.; Lunine, J.I.; Simon-Miller, A. A.; Atreya, S. K.; Brinckerhoff, W.; Colaprete, A.; Coustenis, A.; Fletcher, L. N.; Guillot, T.; Lebreton, J.-P.; Mahaffy, P.; Mousis, O.; Orton, G. S.; Reh, K.; Spilker, L. J.; Spilker, T. R.; Webster, C.

    2014-01-01

    A fundamental goal of solar system exploration is to understand the origin of the solar sys-tem, the initial stages, conditions, and processes by which the solar system formed, how the formation pro-cess was initiated, and the nature of the interstellar seed material from which the solar system was born. Key to understanding solar system formation and subsequent dynamical and chemical evolution is the origin and evolution of the giant planets and their atmospheres. Several theories have been put forward to explain the process of solar system formation, and the origin and evolution of the giant planets and their atmospheres. Each theory offers quantifiable predictions of the abundances of noble gases He, Ne, Ar, Kr, and Xe, and abundances of key isotopic ratios 4He3He, DH, 15N14N, 18O16O, and 13C12C. Detection of certain dis-equilibrium species, diagnostic of deeper internal pro-cesses and dynamics of the atmosphere, would also help discriminate between competing theories. Measurements of the critical abundance profiles of these key constituents into the deeper well-mixed at-mosphere must be complemented by measurements of the profiles of atmospheric structure and dynamics at high vertical resolution and also require in situ explora-tion. The atmospheres of the giant planets can also serve as laboratories to better understand the atmospheric chem-istries, dynamics, processes, and climates on all planets including Earth, and offer a context and provide a ground truth for exoplanets and exoplanetary systems. Additionally, Giant planets have long been thought to play a critical role in the development of potentially habitable planetary systems. In the context of giant planet science provided by the Galileo, Juno, and Cassini missions to Jupiter and Sat-urn, a small, relatively shallow Saturn probe capable of measuring abundances and isotopic ratios of key at-mospheric constituents, and atmospheric structure in-cluding pressures, temperatures, dynamics, and cloud

  3. satellite and in-situ measurements

    Directory of Open Access Journals (Sweden)

    José de Jesús Salas Pérez

    2005-01-01

    Full Text Available La distribución espacial y temporal de la circulación superficial de la Bahía de Banderas se obtuvo con el empleo de series temporales de rapidez de viento, temperatura superficial del mar (AVHR radiómetro y un termógrafo, nivel del mar y trazas ascendentes y descendentes del radar altimétrico ERS-2. El período que abarca dichos datos es de cuatro años, ya que comenzó en el verano de 1997 y finalizó en el invierno de 2002. La marea en la Bahía es mixta (F=0.25 con predominio del armónico M2. La bahía no muestra características de resonancia con la marea del mar abierto. Amplitudes promedio de 30 cms., resultan en corrientes de marea de pocos cms./s. Las bajas frecuencias (periodos mayores a tres días parecen ser los principales generadores de la circulación marina en esta área, en la que predomina el periodo estacional sobre los otros periodos. FEOs fueron aplicadas a las componentes de velocidad, calculadas con observaciones de altimetría medidas en la boca de la Bahía, las cuales mostraron dos principales distribuciones espaciales. El primer periodo de distribución, que se extendió desde febrero hasta julio, muestra un flujo de entrada por la porción norte/sur de la bahía, con un flujo de salida por su boca (distribución anticiclónica. El segundo periodo se extiende desde agosto hasta diciembre y es opuesto al primero (distribución ciclónica. Las características de la circulación aquí presentadas son hipotéticas y observaciones de velocidad medidas in-situ deben confirmarlas

  4. Structural behavior of Pd40Cu30Ni10P20 bulk metallic glass below and above the glass transition

    DEFF Research Database (Denmark)

    Mattern, N.; Hermann, H.; Roth, S.;

    2003-01-01

    The thermal behavior of the structure of Pd40Cu30Ni10P20 bulk metallic glass has been investigated in situ through the glass transition by means of high-temperature x-ray synchrotron diffraction. The dependence of the x-ray structure factor S(q) of the Pd40Cu30Ni10P20 glass on temperature follows...

  5. Interplay between nanoscale reactivity and bulk performance of H-ZSM-5 catalysts during the methanol-to-hydrocarbons reaction

    NARCIS (Netherlands)

    Aramburo, Luis R.; Teketel, Shewangizaw; Svelle, Stian; Bare, Simon R.; Arstad, Bjornar; Zandbergen, Henny W.; Olsbye, Unni; de Groot, Frank M. F.; Weckhuysen, Bert M.

    2013-01-01

    H-ZSM-5 catalyst powders before and after a steaming post-treatment have been investigated during the Methanol-To-Hydrocarbons (MTH) process at 350 degrees C. Bulk and surface characterization techniques have been combined with in situ Scanning Transmission X-ray Microscopy (STXM) at the aluminum an

  6. Fast optical in situ spectroscopy in III-V MOVPE

    Energy Technology Data Exchange (ETDEWEB)

    Kaspari, C.

    2007-09-29

    This work describes the application of optical in situ measurement techniques (reflectance anisotropy spectroscopy, RAS, and spectroscopic ellipsometry, SE) to processes that are important for the growth of III-V semiconductors like GaAs, InP, InAs and GaP in metal-organic vapour phase epitaxy (MOVPE). Special emphasis is placed on the determination of the free carrier concentration (doping level) and the study of the thermal desorption properties of III-V oxides. A large part of this work is concerned with the development and the construction of a multichannel RAS setup that allows the recording of RAS spectra within fractions of a second. On the basis of benchmark measurements it was shown that the spectral resolution is sufficiently accurate for application in epitaxy. To demonstrate the recording of spectra with high temporal resolution, RAS monolayer oscillations during growth of GaAs were studied and it was shown that the surface changes periodically between a relatively smooth morphology with adsorbed methyl groups (type III) and a stepped, gallium-rich surface (type II). Furthermore the non-reversible process of growing InAs quantum dots on GaAs was studied. It was shown that the multichannel RAS is capable of detecting the 2D-3D transition as well as the following morphological change of the surface at high temporal resolution. For the measurement of the doping level, the relationship between the doping-induced internal electric field and the anisotropy of the sample was studied. To understand the effect of the so-called doping oscillations, a theoretical model was developed. For the investigation of the thermal desorption of the III-V oxides in MOVPE, a number of test series were realised. It was also found that the formation of the reconstructed surface is finished a considerable time after the SE transient indicates stable conditions (no further reduction of the oxide layer). The activation energy for oxide desorption from InAs, GaAs and InP was

  7. In-situ grown silica sinters in Icelandic geothermal areas.

    Science.gov (United States)

    Tobler, Dominique J; Stefánsson, Andri; Benning, Liane G

    2008-12-01

    Field in-situ sinter growth studies have been carried out in five geochemically very different Icelandic geothermal areas with the aim to quantify the effects of water chemistry, (e.g. silica content (250 to 695 p.p.m. SiO(2)), salinity (meteoric to seawater), pH (7.5 to 10)), temperature (42-96 degrees C) and microbial abundance (prevalence, density) on the growth rates, textures and structures of sinters forming within and around geothermal waters. At each location, sinter growth was monitored over time periods between 30 min and 25 months using glass slides that acted as precipitation substrates from which sinter growth rates were derived. In geothermal areas like Svartsengi and Reykjanes, subaqueous sinters developed rapidly with growth rates of 10 and 304 kg year(-1 )m(-2), respectively, and this was attributed primarily to the near neutral pH, high salinity and medium to high silica content within these geothermal waters. The porous and homogeneous precipitates that formed at these sites were dominated by aggregates of amorphous silica and they contained few if any microorganisms. At Hveragerdi and Geysir, the geothermal waters were characterized by slightly alkaline pH, low salinity and moderate silica contents, resulting in substantially lower rates of sinter growth (0.2-1.4 kg year(-1 )m(-2)). At these sites sinter formation was restricted to the vicinity of the air-water interface (AWI) where evaporation and condensation processes predominated, with sinter textures being governed by the formation of dense and heterogeneous crusts with well-defined spicules and silica terraces. In contrast, the subaqueous sinters at these sites were characterized by extensive biofilms, which, with time, became fully silicified and thus well preserved within the sinter edifices. Finally, at Krafla, the geothermal waters exhibited high sinter growth rates (19.5 kg year(-1 )m(-2)) despite being considerably undersaturated with respect to amorphous silica. However, the bulk of

  8. EBSD coupled to SEM in situ annealing for assessing recrystallization and grain growth mechanisms in pure tantalum.

    Science.gov (United States)

    Kerisit, C; Logé, R E; Jacomet, S; Llorca, V; Bozzolo, N

    2013-06-01

    An in situ annealing stage has been developed in-house and integrated in the chamber of a Scanning Electron Microscope equipped with an Electron BackScattered Diffraction system. Based on the Joule effect, this device can reach the temperature of 1200°C at heating rates up to 100°C/s, avoiding microstructural evolutions during heating. A high-purity tantalum deformed sample has been annealed at variable temperature in the range 750°C-1030°C, and classical mechanisms of microstructural evolutions such as recrystallization and grain coarsening phenomena have been observed. Quantitative measurements of grain growth rates provide an estimate of the mean grain boundary mobility, which is consistent with the value estimated from physical parameters reported for that material. In situ annealing therefore appears to be suited for complementing bulk measurements at relatively high temperatures, in the context of recrystallization and grain growth in such a single-phase material.

  9. A NOVEL EOR POLYMER (Ⅱ) INVESTIGATION ON IN-SITU GELATION OF SMRF SYSTEM IN BEREA CORE

    Institute of Scientific and Technical Information of China (English)

    ZHUANG Yinfeng; Stanley McCool; G. Paul Willhite; Don W. Green

    1995-01-01

    In-situ gelation of aqueous sulfomethylated resorcinol formaldehyde (SMRF) system in Berea core has been investigated. Two sets of displacement experiments were conducted with this system (containing 5% NaCl, 0.036% CaCl2 · 2H2O). The brine permeabilities of the cores were reduced significantly from about 600 to 0.1 md. The in-situ gelation in Berea core-occurred a little bit earlier than gelation anticipated from bulk test in the experiments. The gel time was easier to control at initial pH between 6 and 8. During injection of SMRF system, the apparent viscosity was less than 1 mpa · s at 41℃.

  10. In situ quantification of genomic instability in breast cancer progression

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz de Solorzano, Carlos; Chin, Koei; Gray, Joe W.; Lockett, Stephen J.

    2003-05-15

    Genomic instability is a hallmark of breast and other solid cancers. Presumably caused by critical telomere reduction, GI is responsible for providing the genetic diversity required in the multi-step progression of the disease. We have used multicolor fluorescence in situ hybridization and 3D image analysis to quantify genomic instability cell-by-cell in thick, intact tissue sections of normal breast epithelium, preneoplastic lesions (usual ductal hyperplasia), ductal carcinona is situ or invasive carcinoma of the breast. Our in situ-cell by cell-analysis of genomic instability shows an important increase of genomic instability in the transition from hyperplasia to in situ carcinoma, followed by a reduction of instability in invasive carcinoma. This pattern suggests that the transition from hyperplasia to in situ carcinoma corresponds to telomere crisis and invasive carcinoma is a consequence of telomerase reactivation afertelomere crisis.

  11. In Situ Oxygen Production from Lunar and Martian Regolith Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In situ oxygen production is of immense importance to NASA in the support of the NASA initiative to sustain man's permanent presence in space. The oxygen produced...

  12. In Situ Instrument to Detect Prebiotic Compounds in Planetary Ices

    Science.gov (United States)

    Getty, Stephanie A.; Dworkin, Jason; Glavin, Daniel P.; Southard, Adrian; Balvin, Manuel; Kotecki, Carl; Ferrance, Jerome

    2013-01-01

    The development of an in situ LC-MS instrument for future planetary science missions to icy surfaces that are of high astrobiology and astrochemistry potential will advance our understanding of organics in the solar system.

  13. Novel Instrumentation for In Situ Combustion Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the Phase I is to develop, demonstrate and test a novel instrument based on laser absorption diagnostics for fast, in situ measurements of important...

  14. Epoxy nanodielectrics fabricated with in situ and ex situ techniques

    Energy Technology Data Exchange (ETDEWEB)

    Tuncer, Enis [ORNL; Polyzos, Georgios [ORNL; Sauers, Isidor [ORNL; James, David Randy [ORNL; Ellis, Alvin R [ORNL; More, Karren Leslie [ORNL

    2012-01-01

    In this study, we report fabrication and characterisation of a nanocomposite system composed of a commercial resin and extremely small (several nanometres in diameter) titanium dioxide particles. Nanoparticles were synthesised in situ with particle nucleation occurring inside the resin matrix. In this nanodielectric fabrication method, the nanoparticle precursor was mixed to the resin solution, and the nanoparticles were in situ precipitated. Note that no high shear mixing equipment was needed to improve particle dispersion - nanoparticles were distributed in the polymer matrix uniformly since particle nucleation occurs uniformly throughout the matrix. The properties of in situ nanodielectrics are compared to the unfilled resin and an ex situ nanocomposite. We anticipate that the presented in situ nanocomposite would be employed in high-temperature superconductivity applications. In additions, the improvement shown in the dielectric breakdown indicates that conventional high-voltage components and systems can be reduced in size with novel nanodielectrics.

  15. Novel Instrumentation for In Situ Combustion Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the Phase I is to develop, demonstrate and test a novel instrument based on laser absorption diagnostics for fast, in situ measurements of...

  16. Fathead minnow whole-mount in situ hybridization (WISH)

    Data.gov (United States)

    U.S. Environmental Protection Agency — This study demonstrates the potential of whole-mount in situ hybridization (WISH), in conjunction with quantitative real-time polymerase chain reaction (QPCR)...

  17. An Efficient Heat Exchanger for In Situ Resource Utilization Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In situ resource utilization (ISRU) is essential for several of NASA's future flagship missions. Currently envisioned ISRU plants include production of oxygen from...

  18. Real-Time In Situ Landing Site Assessment

    Science.gov (United States)

    Adams, D.; Hibbard, K.; McGee, T.

    2017-02-01

    Landing spacecraft on other objects in the solar system provides a unique opportunity to make direct in situ science measurements, but extraterrestrial environments create unique challenges for the design and testing of the system.

  19. In-situ Airborne Sampler for Advanced Guided Dropsonde Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is a low-cost, retrievable and reusable, autonomously guided dropsonde capable of in-situ atmospheric measurements. The proposed effort will...

  20. In situ guided tissue regeneration in musculoskeletal diseases and aging

    OpenAIRE

    Jakob, Franz; Ebert, Regina; Rudert, Maximilian; Nöth, Ulrich; Walles, Heike; Docheva, Denitsa; Schieker, Matthias; Meinel, Lorenz; Groll, Jürgen

    2016-01-01

    In situ guided tissue regeneration, also addressed as in situ tissue engineering or endogenous regeneration, has a great potential for population-wide “minimal invasive” applications. During the last two decades, tissue engineering has been developed with remarkable in vitro and preclinical success but still the number of applications in clinical routine is extremely small. Moreover, the vision of population-wide applications of ex vivo tissue engineered constructs based on cells, growth and ...

  1. Characterization of VPO ammoxidation catalysts by in situ methods

    Energy Technology Data Exchange (ETDEWEB)

    Martin, A.; Luecke, B.; Brueckner, A.; Steinike, U. [Institut fuer Angewandte Chemie Berlin-Adlershof e.V., Berlin (Germany); Brzezinka, K.W. [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany); Meisel, M. [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Chemie

    1998-12-31

    In-situ methods are well known as powerful tools in studying catalyst formation processes, their solid state properties under working conditions and the interaction with the feed, intermediates and products to reveal reaction mechanisms. This paper gives a short overview on results of intense studies using in-situ techniques to reveal VPO catalyst generation processes, interaction of educts, intermediates and products with VPO catalyst surfaces and mechanistic insights. Catalytic data of the ammoxidation of toluene on different VPOs complete these findings. The precursor-catalyst transformation processes were preferently investigated by in-situ XRD, in-situ Raman and in-situ ESR spectroscopy. The interaction of aromatic molecules and intermediates, resp., and VPO solid surfaces was followed by in-situ ESR and in-situ FTIR spectroscopy. Mechanistic information was mainly obtained using in-situ FTIR spectroscopy and the temporal-analysis-of-products (TAP) technique. Catalytic studies were carried out in a fixed-bed microreactor on pure (NH{sub 4}){sub 2}(VO){sub 3}(P{sub 2}O{sub 7}){sub 2}, generated [(NH{sub 4}){sub 2}(VO{sub 3})(P{sub 2}O{sub 7}){sub 2}+V{sub x}O{sub y}] catalysts, having different V{sub x}O{sub y} proportions by use of VOHPO{sub 4} x 1/2H{sub 2}O (V/P=1) and recently studied (VO){sub 3}(PO{sub 4}){sub 2} x 7 H{sub 2}O (V/P=1.5) precursors; the well-known (VO){sub 2}P{sub 2}O{sub 7} was used for comparison. (orig.)

  2. Matrix diffusion model. In situ tests using natural analogues

    Energy Technology Data Exchange (ETDEWEB)

    Rasilainen, K. [VTT Energy, Espoo (Finland)

    1997-11-01

    Matrix diffusion is an important retarding and dispersing mechanism for substances carried by groundwater in fractured bedrock. Natural analogues provide, unlike laboratory or field experiments, a possibility to test the model of matrix diffusion in situ over long periods of time. This thesis documents quantitative model tests against in situ observations, done to support modelling of matrix diffusion in performance assessments of nuclear waste repositories. 98 refs. The thesis includes also eight previous publications by author.

  3. In situ primary production in young Antarctic sea ice

    OpenAIRE

    Mock, Thomas

    2002-01-01

    An in situ incubation technique used successfully to measure the photosynthetic carbon assimilation of internal algal assemblages within thick multiyear Arctic sea ice was developed and improved to measure the photosynthetic carbon assimilation within young sea ice only 50 cm thick (Eastern Weddell Sea, Antarctica). The new device enabled some of the first precise measurements of in situ photosynthetic carbon assimilation in newly formed Antarctic sea ice.

  4. Advanced and In Situ Analytical Methods for Solar Fuel Materials.

    Science.gov (United States)

    Chan, Candace K; Tüysüz, Harun; Braun, Artur; Ranjan, Chinmoy; La Mantia, Fabio; Miller, Benjamin K; Zhang, Liuxian; Crozier, Peter A; Haber, Joel A; Gregoire, John M; Park, Hyun S; Batchellor, Adam S; Trotochaud, Lena; Boettcher, Shannon W

    2016-01-01

    In situ and operando techniques can play important roles in the development of better performing photoelectrodes, photocatalysts, and electrocatalysts by helping to elucidate crucial intermediates and mechanistic steps. The development of high throughput screening methods has also accelerated the evaluation of relevant photoelectrochemical and electrochemical properties for new solar fuel materials. In this chapter, several in situ and high throughput characterization tools are discussed in detail along with their impact on our understanding of solar fuel materials.

  5. IN SITU FIELD TESTING OF PROCESSES

    Energy Technology Data Exchange (ETDEWEB)

    J.S.Y. YANG

    2004-11-08

    The purpose of this scientific analysis report is to update and document the data and subsequent analyses from ambient field-testing activities performed in underground drifts and surface-based boreholes through unsaturated zone (UZ) tuff rock units. In situ testing, monitoring, and associated laboratory studies are conducted to directly assess and evaluate the waste emplacement environment and the natural barriers to radionuclide transport at Yucca Mountain. This scientific analysis report supports and provides data to UZ flow and transport model reports, which in turn contribute to the Total System Performance Assessment (TSPA) of Yucca Mountain, an important document for the license application (LA). The objectives of ambient field-testing activities are described in Section 1.1. This report is the third revision (REV 03), which supercedes REV 02. The scientific analysis of data for inputs to model calibration and validation as documented in REV 02 were developed in accordance with the Technical Work Plan (TWP) ''Technical Work Plan for: Performance Assessment Unsaturated Zone'' (BSC 2004 [DIRS 167969]). This revision was developed in accordance with the ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Section 1.2.4) for better integrated, consistent, transparent, traceable, and more complete documentation in this scientific analysis report and associated UZ flow and transport model reports. No additional testing or analyses were performed as part of this revision. The list of relevant acceptance criteria is provided by ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654]), Table 3-1. Additional deviations from the TWP regarding the features, events, and processes (FEPs) list are discussed in Section 1.3. Documentation in this report includes descriptions of how, and under what

  6. Characterizing In Situ Uranium and Groundwater Flux

    Science.gov (United States)

    Cho, J.; Newman, M. A.; Stucker, V.; Peacock, A.; Ranville, J.; Cabaniss, S.; Hatfield, K.; Annable, M. D.; Klammler, H.; Perminova, I. V.

    2010-12-01

    The goal of this project is to develop a new sensor that incorporates the field-tested concepts of the passive flux meter to provide direct in situ measures of uranium and groundwater fluxes. The sensor uses two sorbents and resident tracers to measure uranium flux and specific discharge directly; but, sensor principles and design should also apply to fluxes of other radionuclides. Flux measurements will assist with obtaining field-scale quantification of subsurface processes affecting uranium transport (e.g., advection) and transformation (e.g., uranium attenuation) and further advance conceptual and computational models for field scale simulations. Project efforts will expand our current understanding of how field-scale spatial variations in uranium fluxes and those for salient electron donor/acceptors, and groundwater are coupled to spatial variations in measured microbial biomass/community composition, effective field-scale uranium mass balances, attenuation, and stability. The new sensor uses an anion exchange resin to measure uranium fluxes and activated carbon with resident tracers to measure water fluxes. Several anion-exchange resins including Dowex 21K and 21K XLT, Purolite A500, and Lewatit S6328 were tested as sorbents for capturing uranium on the sensor and Lewatit S6328 was determined to be the most effective over the widest pH range. Four branched alcohols proved useful as resident tracers for measuring groundwater flows using activated carbon for both laboratory and field conditions. The flux sensor was redesigned to prevent the discharge of tracers to the environment, and the new design was tested in laboratory box aquifers and the field. Geochemical modeling of equilibrium speciation using Visual Minteq and an up-to-date thermodynamic data base suggested Ca-tricarbonato-uranyl complexes predominate under field conditions, while calculated uranyl ion activities were sensitive to changes in pH, dissolved inorganic carbon (DIC) and alkaline earth

  7. Can bulk viscosity drive inflation

    Energy Technology Data Exchange (ETDEWEB)

    Pacher, T.; Stein-Schabes, J.A.; Turner, M.S.

    1987-04-01

    Contrary to other claims, we argue that, bulk viscosity associated with the interactions of nonrelativistic particles with relativistic particles around the time of the grand unified theory (GUT) phase transition cannot lead to inflation. Simply put, the key ingredient for inflation, negative pressure, cannot arise due to the bulk viscosity effects of a weakly-interacting mixture of relativistic and nonrelativistic particles. 13 refs., 1 fig.

  8. Transitions of amorphous- crystalline-amorphous in bulk metallic glass under HP and HT

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In-situ SR-XRD measurements revealed that the crystallization process in Zr41.2Ti13.sCu12.5Ni10Be22.5 bulk metallic glass is significantly different from that in traditional glasses. Subsequent heating at 10 GPa converts the sample from amorphous phase into the metastable fcc phase and then leads to the fcc phase back to the amorphous phase,nomena in the material under high pressure and high temperature.``

  9. Assessment of Shape Memory Alloys - From Atoms To Actuators - Via In Situ Neutron Diffraction

    Science.gov (United States)

    Benafan, Othmane

    2014-01-01

    As shape memory alloys (SMAs) become an established actuator technology, it is important to identify the fundamental mechanisms responsible for their performance by understanding microstructure performance relationships from processing to final form. Yet, microstructural examination of SMAs at stress and temperature is often a challenge since structural changes occur with stress and temperature and microstructures cannot be preserved through quenching or after stress removal, as would be the case for conventional materials. One solution to this dilemma is in situ neutron diffraction, which has been applied to the investigation of SMAs and has offered a unique approach to reveal the fundamental micromechanics and microstructural aspects of bulk SMAs in a non-destructive setting. Through this technique, it is possible to directly correlate the micromechanical responses (e.g., internal residual stresses, lattice strains), microstructural evolutions (e.g., texture, defects) and phase transformation properties (e.g., phase fractions, kinetics) to the macroscopic actuator behavior. In this work, in situ neutron diffraction was systematically employed to evaluate the deformation and transformation behavior of SMAs under typical actuator conditions. Austenite and martensite phases, yield behavior, variant selection and transformation temperatures were characterized for a polycrystalline NiTi (49.9 at. Ni). As the alloy transforms under thermomechanical loading, the measured textures and lattice plane-level variations were directly related to the cyclic actuation-strain characteristics and the dimensional instability (strain ratcheting) commonly observed in this alloy. The effect of training on the shape memory characteristics of the alloy and the development of two-way shape memory effect (TWSME) were also assessed. The final conversion from a material to a useful actuator, typically termed shape setting, was also investigated in situ during constrained heatingcooling and

  10. Optically transparent polymer devices for in situ assessment of cell electroporation.

    Science.gov (United States)

    Majhi, Amit Kumar; Thrivikraman, Greeshma; Basu, Bikramjit; Venkataraman, V

    2015-02-01

    In order to study cell electroporation in situ, polymer devices have been fabricated from poly-dimethyl siloxane with transparent indium tin oxide parallel plate electrodes in horizontal geometry. This geometry with cells located on a single focal plane at the interface of the bottom electrode allows a longer observation time in both transmitted bright-field and reflected fluorescence microscopy modes. Using propidium iodide (PI) as a marker dye, the number of electroporated cells in a typical culture volume of 10-100 μl was quantified in situ as a function of applied voltage from 10 to 90 V in a series of ~2-ms pulses across 0.5-mm electrode spacing. The electric field at the interface and device current was calculated using a model that takes into account bulk screening of the transient pulse. The voltage dependence of the number of electroporated cells could be explained using a stochastic model for the electroporation kinetics, and the free energy for pore formation was found to be 45.6 ± 0.5 kT at room temperature. With this device, the optimum electroporation conditions can be quickly determined by monitoring the uptake of PI marker dye in situ under the application of millisecond voltage pulses. The electroporation efficiency was also quantified using an ex situ fluorescence-assisted cell sorter, and the morphology of cultured cells was evaluated after the pulsing experiment. Importantly, the efficacy of the developed device was tested independently using two cell lines (C2C12 mouse myoblast cells and yeast cells) as well as in three different electroporation buffers (phosphate buffer saline, electroporation buffer and 10% glycerol).

  11. An in situ measurement of the radio-frequency attenuation in ice at Summit Station, Greenland

    CERN Document Server

    Avva, J; Miki, C; Saltzberg, D; Vieregg, A G

    2014-01-01

    We report an in situ measurement of the electric field attenuation length at radio frequencies for the bulk ice at Summit Station, Greenland, made by broadcasting radio-frequency signals vertically through the ice and measuring the relative power in the return ground bounce signal. We find the depth-averaged field attenuation length to be 947 +92/-85 meters at 75 MHz. While this measurement has clear radioglaciological applications, the radio clarity of the ice also has implications for the detection of ultra-high energy (UHE) astrophysical particles via their radio emission in dielectric media such as ice. The measured attenuation length at Summit Station is comparable to previously measured radio-frequency attenuation lengths at candidate particle detector sites around the world, and strengthens the case for Summit Station as the most promising northern site for UHE neutrino detection.

  12. In situ probing of surface hydrides on hydrogenated amorphous silicon using attenuated total reflection infrared spectroscopy

    CERN Document Server

    Kessels, W M M; Sanden, M C M; Aydil, E S

    2002-01-01

    An in situ method based on attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) is presented for detecting surface silicon hydrides on plasma deposited hydrogenated amorphous silicon (a-Si:H) films and for determining their surface concentrations. Surface silicon hydrides are desorbed by exposing the a-Si:H films to low energy ions from a low density Ar plasma and by comparing the infrared spectrum before and after this low energy ion bombardment, the absorptions by surface hydrides can sensitively be separated from absorptions by bulk hydrides incorporated into the film. An experimental comparison with other methods that utilize isotope exchange of the surface hydrogen with deuterium showed good agreement and the advantages and disadvantages of the different methods are discussed. Furthermore, the determination of the composition of the surface hydrogen bondings on the basis of the literature data on hydrogenated crystalline silicon surfaces is presented, and quantification of the h...

  13. Solution spectroelectrochemical cell for in situ X-ray absorption fine structure

    Energy Technology Data Exchange (ETDEWEB)

    Antonio, M.R.; Soderholm, L. [Argonne National Lab., IL (United States). Chemistry Div.; Song, I. [Case Western Reserve Univ., Cleveland, OH (United States)

    1995-06-12

    A purpose-built spectroelectrochemical cell for in situ fluorescence XAFS (X-ray Absorption Fine Structure) measurements of bulk solution species during constant-potential electrolysis is described. The cell performance was demonstrated by the collection of europium L{sub 3}-edge XANES (X-ray Absorption Near Edge Structure) throughout the course of electrolysis of an aqueous solution of EuCl{sub 3}{center_dot}6H{sub 2}O in 1 M H{sub 2}SO{sub 4}. The europium L{sub 3}-edge resonances reported here for the Eu{sup III} and Eu{sup II} ions demonstrate that their 2p{sub 3/2} {yields} 5d electronic transition probabilities are not the same.

  14. Titanium boride equation of state determined by in-situ X-ray diffraction.

    Science.gov (United States)

    Ono, Shigeaki; Kikegawa, Takumi

    2016-12-01

    The equation of state (EOS) of titanium boride, TiB2, was investigated by in situ X-ray diffraction in a diamond anvil cell and multianvil high-pressure apparatus. The pressure-volume-temperature (P-V-T) data were collected at up to 111 GPa and room temperature for the diamond-anvil cell experiments and at up to 15 GPa and 1300 K for the multianvil experiments. No phase transition was observed through the entire range of experimental conditions. The pressure-volume data at room temperature were fitted using a Vinet EOS to obtain the isothermal bulk modulus, BT0 = 256.7 GPa, and its pressure derivative, B' T0 = 3.83. When fitting a thermal EOS using the P-V-T data for the multianvil experiments, we find that [Formula: see text] = 0.095 (GPa/K) and α 0 = 2.49 × 10(-5) K(-1).

  15. SYNTHESIS OF POLY(VINYL ACETATE)-INTERCALATED GRAPHITE OXIDE BY AN IN SITU INTERCALATIVE POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Ping-gui Liu; Peng Xiao; Min Xiao; Ke-cheng Gong

    2000-01-01

    Graphite oxide, a pseudo-two-dimensional solid in bulk form, was synthesized from natural graphite powder by oxidization with KMnO4 in concentrated H2SO4. The poly(vinyl acetate)-intercalated graphite oxide nano-composite was prepared by an in situ intercalative polymerization reaction, in which n-octanol-graphite oxide intercalation compounds were first obtained, vinyl acetate monomer was then dispersed into the interlayer of modified graphite oxide, followed by thermal polymerization of the monomer. It was experimentally shown that the c-axis space ofpoly(vinyl acetate)-intercalated graphite oxide was increased to 0.115 nm, which suggested there existed a monolayer of poly(vinyl acetate) chain between the layers of graphite oxide. The nanocomposite was also characterized with thermal analysis and FT-IR spectrometry.

  16. In Situ XRD Studies of the Process Dynamics During Annealing in Cold-Rolled Copper

    Science.gov (United States)

    Dey, Santu; Gayathri, N.; Bhattacharya, M.; Mukherjee, P.

    2016-09-01

    The dynamics of the release of stored energy during annealing along two different crystallographic planes, i.e., {111} and {220}, in deformed copper have been investigated using in situ X-ray diffraction measurements at 458 K and 473 K (185 °C and 200 °C). The study has been carried out on 50 and 80 pct cold-rolled Cu sheets. The microstructures of the rolled samples have been characterized using optical microscopy and electron backscattered diffraction measurements. The microstructural parameters were evaluated from the X-ray diffractogram using the Scherrer equation and the modified Rietveld method. The stored energy along different planes was determined using the modified Stibitz formula from the X-ray peak broadening, and the bulk stored energy was evaluated using differential scanning calorimetry. The process dynamics of recovery and recrystallization as observed through the release of stored energy have been modeled as the second-order and first-order processes, respectively.

  17. Controlling the work function of molybdenum disulfide by in situ metal deposition.

    Science.gov (United States)

    Zhou, Peng; Song, Xiongfei; Yan, Xiao; Liu, Chunsen; Chen, Lin; Sun, Qingqing; Zhang, David Wei

    2016-08-26

    Control of the work function of molybdenum disulfide (MoS2) under ultrathin metal was investigated using in situ metal deposition and direct ultraviolet photoelectron spectroscopy measurement in an ultra-high vacuum system. When the metal thickness turned from two dimensional into bulk, the work function was also raised up at the nickel-MoS2 interface, barely changed at the titanium-MoS2 interface and lowered at the hafnium-MoS2 interface. Meanwhile, the mechanisms of charge transfer and band alignment with metal deposition were also discussed. The Schottky barrier at metal-MoS2 interfaces could be tailored by both types and thicknesses of deposited metal. The low work function metal was a good indicator for MoS2 contact electrodes. It paved the way towards future high performance MoS2 device applications.

  18. Challenges (and Promise) of In-Situ Lithospheric Rheology from Isostatic Strength Analyses

    Science.gov (United States)

    Lowry, Anthony R.; Becker, Thorsten W.; Buehler, Janine S.; Miller, Meghan S.; Pérez-Gussinyé, Marta; Schutt, Derek L.; Seunarine, Lisa L.

    2013-04-01

    Measurements of effective elastic thickness, Te, from flexural isostatic modeling are sensitive to flow rheology of the lithosphere. Nevertheless Te has not been widely used to estimate in-situ rheology, partly owing to methodological questions regarding the measurement of Te and partly because of uncertainties in other in-situ properties of temperature, composition, water content and state-of-stress of the lithosphere. Dense seismic and other geophysical arrays such as EarthScope's USArray are providing a wealth of new information about physical state of the lithosphere, however, and the relationships of these data to Te promises new insights into lithospheric rheology and deformation processes. For example, new estimates of subsurface mass distributions derived from seismic data enable us to examine various controversial assumptions about the nature of lithospheric loads. Variations in crustal composition evident in bulk crustal velocity ratio, vP-vS, contribute a surprisingly large fraction of total loading, and elevation models better match observations if Moho flexure is not forced to match surface flexure, indicating that lower crustal flow and other crustal mass transfer processes are significant. Perhaps the most interesting new information on physical state derives from imaging of uppermost mantle velocities using refracted mantle phases, Pn and Sn, and depths to negative velocity gradients imaged as converted phases in receiver functions (seismic lithosphere-asthenosphere boundary, "LAB"). We will compare Te measurements to thermal models derived from these seismic fields, and discuss their implications for lithospheric rheological controls and thermal processes.

  19. RBS study of in situ grown BiSrCaCuO films

    Energy Technology Data Exchange (ETDEWEB)

    Ranno, L.; Perriere, J.; Enard, J.P.; Kerherve, F.; Laurent, A.; Casero, R.P. (Paris-6 Univ., 75 (France). Lab. de Physique des Solides)

    1992-07-01

    BiSrCaCuO thin films have been grown in situ on MgO single crystals by pulsed laser deposition under 0.1 mbar oxygen pressure, the substrate temperature being around 700{sup o}C. These films are nearly pure 2212 phase, highly textured with a full c-axis orientation, and Rutherford backscattering spectrometry (RBS) in channeling geometry has been used to obtain precise information on their crystallinity. Although the X{sub min} values were found higher (about 35%) than those measured on bulk single crystals, they show partial epitaxy of the films, which was not observed with post annealed films. The comparison of backscattering yield in random and aligned orientations evidences the fact that all the cationic elements behave in a similar way in the channeling experiments, while differences are observed for the oxygen species according to their precise location in the network. These in situ grown films were found very sensitive to the ion irradiation, and showed a large dechanneling effect with increasing ion doses. (author).

  20. In-situ hydrogen and oxygen plasma purification of carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Mi Hyun; Kim, Yang Do; Jeon, Hyeong Tag [Hanyang Univ., Seoul (Korea, Republic of)

    2001-12-01

    Bulk bundles, which are obtained after purification of carbon soot containing nanotubes (CNTs), are commonly used as electron emitters. However, CNTs grown by chemical vapor deposition (CVD) at low temperature using a nickel (Ni) catalyst still contain impurities, such as amorphous carbon and catalytic metal particles, and need to be purified. We grew CNTs on silicon substrates with native oxides by using a Ni catalyst and plasma-enhanced CVD at 600 .deg. C with a mixture of CH{sub 4}, NH{sub 3}, and H{sub 2} gases. CNTs were observed to have multi-wall structures with large inside hollow cores containing Ni. CNTs with a typical dimension of a few tens of nm in diameter and several m in length were observed. In-situ hydrogen plasma treatment successfully removed the residual carbonaceous particles and metallic impurities without significant structural damage to the individual CNTs. This study demonstrated a simple and efficient in-situ plasma purification process for CNTs grown by using plasma-enhanced CVD.

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

    DEFF Research Database (Denmark)

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

    2009-01-01

    We have used L-Cysteine (Cys) as a model system to study the surface electronic structures of single molecules at the submolecular level in aqueous buffer solution by a combination of electrochemical scanning tunneling microscopy (in situ STM), electrochemistry including voltammetry and chronocou......We have used L-Cysteine (Cys) as a model system to study the surface electronic structures of single molecules at the submolecular level in aqueous buffer solution by a combination of electrochemical scanning tunneling microscopy (in situ STM), electrochemistry including voltammetry...... and tip. The computational images recast as constant-current-height profiles show that the most favorable molecular orientation is the adsorption of cysteine as a radical in zwitterionic form located on the bridge between the Au(I 10) atomic rows and with the amine and carboxyl group toward the solution...... bulk. The correlation between physical location and electronic contrast of the adsorbed molecules was also revealed by the computational data. The present study shows that cysteine packing in the adlayer on Au(110) from the liquid environment is in contrast to that from the ultrahigh-vacuum environment...

  2. In situ X-ray diffraction studies on the piezoelectric response of PZT thin films

    Energy Technology Data Exchange (ETDEWEB)

    Davydok, A., E-mail: davydok@mpie.de [Aix Marseille Université, CNRS, Université de Toulon, IM2NP UMR 7334, 13397 Marseille (France); Max-Planck-Institut für Eisenforschung, Department Structure and Nano-/Micromechanics of Materials, D-40237 Düsseldorf (Germany); Cornelius, T.W. [Aix Marseille Université, CNRS, Université de Toulon, IM2NP UMR 7334, 13397 Marseille (France); Mocuta, C. [SOLEIL Synchrotron, DiffAbs beamline, L' Orme des Merisiers, Saint-Aubin - BP 48, 91192 Gif-sur-Yvette Cedex (France); Lima, E.C. [Universidade Federal do Tocantins, 77500-000 Porto Nacional, TO (Brazil); Araujo, E.B. [Departamento de Fisica e Quimica, Universidade Estadual Paulista, Av. Brasil, 56 Centro, 15385-000 Ilha Solteira, SP (Brazil); Thomas, O. [Aix Marseille Université, CNRS, Université de Toulon, IM2NP UMR 7334, 13397 Marseille (France)

    2016-03-31

    Piezoelectric properties of randomly oriented self-polarized PbZr{sub 0.50}Ti{sub 0.50}O{sub 3} (PZT) thin films were investigated using in situ synchrotron X-ray diffraction. Possibilities for investigating the piezoelectric effect using micro-sized hard X-ray beams are demonstrated and perspectives for future dynamical measurements on PZT samples with variety of compositions and thicknesses are given. Studies performed on the crystalline [100, 110] directions evidenced piezoelectric anisotropy. The piezoelectric coefficient d{sub 33} was calculated in terms of the lab reference frame (d{sub perp}) and found to be two times larger along the [100] direction than along the [110] direction. The absolute values for the d{sub perp} amount to 120 and 230 pm/V being in good agreement with experimental and theoretical values found in literature for bulk PZT ceramics. - Highlights: • We performed in situ synchrotron X-ray diffraction studies on (PZT) thin films. • We discuss anisotropy of piezo effect in different crystallographic directions. • Perpendicular component Piezo coefficient of thin PZT layer is defined.

  3. In situ observations of waves in Venus’s polar lower thermosphere with Venus Express aerobraking

    Science.gov (United States)

    Müller-Wodarg, Ingo C. F.; Bruinsma, Sean; Marty, Jean-Charles; Svedhem, Håkan

    2016-08-01

    Waves are ubiquitous phenomena found in oceans and atmospheres alike. From the earliest formal studies of waves in the Earth’s atmosphere to more recent studies on other planets, waves have been shown to play a key role in shaping atmospheric bulk structure, dynamics and variability. Yet, waves are difficult to characterize as they ideally require in situ measurements of atmospheric properties that are difficult to obtain away from Earth. Thus, we have incomplete knowledge of atmospheric waves on planets other than our own, and we are thereby limited in our ability to understand and predict planetary atmospheres. Here we report the first ever in situ observations of atmospheric waves in Venus’s thermosphere (130-140 km) at high latitudes (71.5°-79.0°). These measurements were made by the Venus Express Atmospheric Drag Experiment (VExADE) during aerobraking from 24 June to 11 July 2014. As the spacecraft flew through Venus’s atmosphere, deceleration by atmospheric drag was sufficient to obtain from accelerometer readings a total of 18 vertical density profiles. We infer an average temperature of T = 114 +/- 23 K and find horizontal wave-like density perturbations and mean temperatures being modulated at a quasi-5-day period.

  4. Antitumor activity of TNF-α after intratumoral injection using an in situ thermosensitive hydrogel.

    Science.gov (United States)

    Xu, Yourui; Shen, Yan; Ouahab, Ammar; Li, Chang; Xiong, Yerong; Tu, Jiasheng

    2015-03-01

    Local drug delivery strategies based on nanoparticles, gels, polymeric films, rods and wafers are increasingly used in cancer chemotherapy in order to enhance therapeutic effect and reduce systemic toxicity. Herein, a biodegradable and biocompatible in situ thermosensitive hydrogel was designed and employed to deliver tumor necrosis factor-α (TNF-α) locally by intratumoral injection. The triblock copolymer was synthesized by ring-opening polymerization (ROP) of β-butyrolactone (β-BL) and lactide (LA) in bulk using polyethylene glycol (PEG) as an initiator and Sn(Oct)2 as the catalyst, the polymer was characterized by NMR, gel permeation chromatography and differential scanning calorimetry. Blood and tumor pharmacokinetics and in vivo antitumor activity of TNF-α after intratumoral administration in hydrogel or solution with the same dose were evaluated on S180 tumor-bearing mice. Compared with TNF-α solution, TNF-α hydrogel exhibited a longer T1/2 (4-fold) and higher AUCtumor (19-fold), but Cmax was lower (0.5-fold), which means that the hydrogel formulation improved the efficacy with a lower systhemic exposure than the solution formation. In addition, TNF-α hydrogel improved the antitumor activity and survival due to lower systemic exposure than the solution. These results demonstrate that the in situ thermosensitive hydrogel-based local delivery system by intratumoral injection is well suited for the administration of TNF-α.

  5. Charge collection in Si detectors irradiated in situ at superfluid helium temperature

    Science.gov (United States)

    Verbitskaya, Elena; Eremin, Vladimir; Zabrodskii, Andrei; Dehning, Bernd; Kurfürst, Christoph; Sapinski, Mariusz; Bartosik, Marcin R.; Egorov, Nicolai; Härkönen, Jaakko

    2015-10-01

    Silicon and diamond detectors operated in a superfluid helium bath are currently being considered for the upgrade of the LHC beam loss monitoring system. The detectors would be installed in immediate proximity of the superconducting coils of the triplet magnets. We present here the results of the in situ irradiation test for silicon detectors using 23 GeV protons while keeping the detectors at a temperature of 1.9 K. Red laser (630 nm) Transient Current Technique and DC current measurements were used to study the pulse response and collected charge for silicon detectors irradiated to a maximum radiation fluence of 1×1016 p/cm2. The dependence between collected charge and irradiation fluence was parameterized using the Hecht equation and assumption of a uniform electric field distribution. The collected charge was found to degrade with particle fluence for both bias polarities. We observed that the main factor responsible for this degradation was related to trapping of holes on the donor-type radiation-induced defects. In contrast to expectations, along with formation of donors, acceptor-type defects (electron traps) are introduced into the silicon bulk. This suggests that the current models describing charge collection in irradiated silicon detectors require an extension for taking into account trapping at low temperatures with a contribution of shallow levels. New in situ irradiation tests are needed and planned now to extend statistics of the results and gain a deeper insight into the physics of low temperature detector operation in harsh radiation environment.

  6. Sphingomyelinase D activity in model membranes: structural effects of in situ generation of ceramide-1-phosphate.

    Directory of Open Access Journals (Sweden)

    Roberto P Stock

    Full Text Available The toxicity of Loxosceles spider venom has been attributed to a rare enzyme, sphingomyelinase D, which transforms sphingomyelin to ceramide-1-phosphate. The bases of its inflammatory and dermonecrotic activity, however, remain unclear. In this work the effects of ceramide-1-phosphate on model membranes were studied both by in situ generation of this lipid using a recombinant sphingomyelinase D from the spider Loxosceles laeta and by pre-mixing it with sphingomyelin and cholesterol. The systems of choice were large unilamellar vesicles for bulk studies (enzyme kinetics, fluorescence spectroscopy and dynamic light scattering and giant unilamellar vesicles for fluorescence microscopy examination using a variety of fluorescent probes. The influence of membrane lateral structure on the kinetics of enzyme activity and the consequences of enzyme activity on the structure of target membranes containing sphingomyelin were examined. The findings indicate that: 1 ceramide-1-phosphate (particularly lauroyl ceramide-1-phosphate can be incorporated into sphingomyelin bilayers in a concentration-dependent manner and generates coexistence of liquid disordered/solid ordered domains, 2 the activity of sphingomyelinase D is clearly influenced by the supramolecular organization of its substrate in membranes and, 3 in situ ceramide-1-phosphate generation by enzymatic activity profoundly alters the lateral structure and morphology of the target membranes.

  7. Ivabradine Hydrochloride (S-Mandelic Acid Co-Crystal: In Situ Preparation during Formulation

    Directory of Open Access Journals (Sweden)

    Veronika Sládková

    2017-01-01

    Full Text Available The pharmaceutical salt ivabradine hydrochloride is indicated for the symptomatic treatment of chronic stable angina pectoris and chronic heart failure. It exhibits extensive polymorphism and co-crystallization, which could be a way to provide an alternative solid form. We conducted a co-crystal screen, from which two hits were identified: with (S-mandelic and (R-mandelic acid. Both structures were determined from single-crystal X-ray diffraction data as co-crystals. The co-crystals were further characterized by common solid-state techniques, such as X-ray powder diffraction (XRPD, differential scanning calorimetry (DSC, solid-state NMR, IR and Raman spectroscopy, and dynamic vapor sorption (DVS. The co-crystal with (S-mandelic acid was selected for further development; its physical and chemical stability was compared with two different polymorphs of the hydrochloride salt. The co-crystal exhibited a similar stability with the polymorph used in the original drug product and was, therefore, selected for formulation into the drug product. During the pre-formulation experiments, the in situ formation of the co-crystal was achieved during the wet granulation process. The following formulation experiments showed no influence of in situ prepared co-crystal on the overall stability of the bulk, when compared with pre-prepared co-crystal formulation.

  8. An Asynchronous Many-Task Implementation of In-Situ Statistical Analysis using Legion.

    Energy Technology Data Exchange (ETDEWEB)

    Pebay, Philippe Pierre [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Bennett, Janine Camille [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2015-11-01

    In this report, we propose a framework for the design and implementation of in-situ analy- ses using an asynchronous many-task (AMT) model, using the Legion programming model together with the MiniAero mini-application as a surrogate for full-scale parallel scientific computing applications. The bulk of this work consists of converting the Learn/Derive/Assess model which we had initially developed for parallel statistical analysis using MPI [PTBM11], from a SPMD to an AMT model. In this goal, we propose an original use of the concept of Legion logical regions as a replacement for the parallel communication schemes used for the only operation of the statistics engines that require explicit communication. We then evaluate this proposed scheme in a shared memory environment, using the Legion port of MiniAero as a proxy for a full-scale scientific application, as a means to provide input data sets of variable size for the in-situ statistical analyses in an AMT context. We demonstrate in particular that the approach has merit, and warrants further investigation, in collaboration with ongoing efforts to improve the overall parallel performance of the Legion system.

  9. Customizable in situ TEM devices fabricated in freestanding membranes by focused ion beam milling.

    Science.gov (United States)

    Lei, Anders; Petersen, Dirch Hjorth; Booth, Timothy John; Homann, Lasse Vinther; Kallesoe, Christian; Sukas, Ozlem Sardan; Gyrsting, Yvonne; Molhave, Kristian; Boggild, Peter

    2010-10-08

    Nano- and microelectromechanical structures for in situ operation in a transmission electron microscope (TEM) were fabricated with a turnaround time of 20 min and a resolution better than 100 nm. The structures are defined by focused ion beam (FIB) milling in 135 nm thin membranes of single crystalline silicon extending over the edge of a pre-fabricated silicon microchip. Four-terminal resistance measurements of FIB-defined nanowires showed at least two orders of magnitude increase in resistivity compared to bulk. We show that the initial high resistance is due to amorphization of silicon, and that current annealing recrystallizes the structure, causing the electrical properties to partly recover to the pristine bulk resistivity. In situ imaging of the annealing process revealed both continuous and abrupt changes in the crystal structure, accompanied by instant changes of the electrical conductivity. The membrane structures provide a simple way to design electron-transparent nanodevices with high local temperature gradients within the field of view of the TEM, allowing detailed studies of surface diffusion processes. We show two examples of heat-induced coarsening of gold on a narrow freestanding bridge, where local temperature gradients are controlled via the electrical current paths. The separation of device processing into a one-time batch-level fabrication of identical, generic membrane templates, and subsequent device-specific customization by FIB milling, provides unparalleled freedom in device layout combined with very short effective fabrication time. This approach significantly speeds up prototyping of nanodevices such as resonators, actuators, sensors and scanning probes with state-of-art resolution.

  10. Customizable in situ TEM devices fabricated in freestanding membranes by focused ion beam milling

    Energy Technology Data Exchange (ETDEWEB)

    Lei, Anders; Petersen, Dirch Hjorth; Booth, Timothy John; Homann, Lasse Vinther; Kallesoe, Christian; Sukas, Ozlem Sardan; Molhave, Kristian; Boggild, Peter [DTU Nanotech, Department of Nano- and Microtechnology, Technical University of Denmark, DK-2800 Kongens Lyngby (Denmark); Gyrsting, Yvonne, E-mail: Anders.Lei@nanotech.dtu.dk [DTU Danchip, National Center for Micro- and Nanofabrication, Technical University of Denmark, DK-2800 Kongens Lyngby (Denmark)

    2010-10-08

    Nano- and microelectromechanical structures for in situ operation in a transmission electron microscope (TEM) were fabricated with a turnaround time of 20 min and a resolution better than 100 nm. The structures are defined by focused ion beam (FIB) milling in 135 nm thin membranes of single crystalline silicon extending over the edge of a pre-fabricated silicon microchip. Four-terminal resistance measurements of FIB-defined nanowires showed at least two orders of magnitude increase in resistivity compared to bulk. We show that the initial high resistance is due to amorphization of silicon, and that current annealing recrystallizes the structure, causing the electrical properties to partly recover to the pristine bulk resistivity. In situ imaging of the annealing process revealed both continuous and abrupt changes in the crystal structure, accompanied by instant changes of the electrical conductivity. The membrane structures provide a simple way to design electron-transparent nanodevices with high local temperature gradients within the field of view of the TEM, allowing detailed studies of surface diffusion processes. We show two examples of heat-induced coarsening of gold on a narrow freestanding bridge, where local temperature gradients are controlled via the electrical current paths. The separation of device processing into a one-time batch-level fabrication of identical, generic membrane templates, and subsequent device-specific customization by FIB milling, provides unparalleled freedom in device layout combined with very short effective fabrication time. This approach significantly speeds up prototyping of nanodevices such as resonators, actuators, sensors and scanning probes with state-of-art resolution.

  11. In situ structural study on underpotential deposition of Ag on Au(111) electrode using surface X-ray scattering technique

    OpenAIRE

    KONDO, Toshihiro; Morita, Jun; Okamura, Masayuki; Saito, Toshiya; Uosaki, Kohei

    2002-01-01

    In situ surface X-ray scattering (SXS) measurements were carried out to study the structure of a Ag layer on a Au(111) electrode formed by underpotential deposition (upd) in sulfuric acid solution. Specular rod profiles showed that a monolayer of Ag was formed at a potential between the second and third upd peaks, and a bilayer of Ag was formed at a potential between the third upd peak and bulk deposition. Non-specular rod profiles demonstrated that electrochemically deposited Ag atoms both i...

  12. In situ vitrification: application analysis for stabilization of transuranic waste

    Energy Technology Data Exchange (ETDEWEB)

    Oma, K.H.; Farnsworth, R.K.; Rusin, J.M.

    1982-09-01

    The in situ vitrification process builds upon the electric melter technology previously developed for high-level waste immobilization. In situ vitrification converts buried wastes and contaminated soil to an extremely durable glass and crystalline waste form by melting the materials, in place, using joule heating. Once the waste materials have been solidified, the high integrity waste form should not cause future ground subsidence. Environmental transport of the waste due to water or wind erosion, and plant or animal intrusion, is minimized. Environmental studies are currently being conducted to determine whether additional stabilization is required for certain in-ground transuranic waste sites. An applications analysis has been performed to identify several in situ vitrification process limitations which may exist at transuranic waste sites. Based on the process limit analysis, in situ vitrification is well suited for solidification of most in-ground transuranic wastes. The process is best suited for liquid disposal sites. A site-specific performance analysis, based on safety, health, environmental, and economic assessments, will be required to determine for which sites in situ vitrification is an acceptable disposal technique. Process economics of in situ vitrification compare favorably with other in-situ solidification processes and are an order of magnitude less than the costs for exhumation and disposal in a repository. Leachability of the vitrified product compares closely with that of Pyrex glass and is significantly better than granite, marble, or bottle glass. Total release to the environment from a vitrified waste site is estimated to be less than 10/sup -5/ parts per year. 32 figures, 30 tables.

  13. In-Situ Spectrometry of Neutrons

    Science.gov (United States)

    Maurer, Richard H.

    1999-01-01

    less damaging, but more prevalent, thermal and epithermal neutrons and to make the structure of the spectrum more accurate in the 20 KeV-2 MeV range; or a pair of tubes, one shielded and one unshielded, can be combined so that the difference in their counts yields the thermal neutron contribution. The spectrometer also uses a 5mm lithium drifted bulk silicon solid state detector in the medium energy range of 2-20 Mev and two standard silicon surface barrier detectors separated by tens of millimeters behind a I cm thick polyethylene moderator in a stack or telescope arrangement for the high energy neutrons (>20 MeV). In the medium and high energy regions equivalent damage factors are lower but hits from one or a small number of neutrons may prove to be important. The silicon detector systems for medium and high energy neutrons will discriminate against charged particles by using a plastic cesium iodide scintillator of an appropriate geometry monitored by a silicon PIN photodiode.

  14. Nanoparticles laden in situ gelling system for ocular drug targeting

    Directory of Open Access Journals (Sweden)

    Divya Kumar

    2013-01-01

    Full Text Available Designing an ophthalmic drug delivery system is one of the most difficult challenges for the researchers. The anatomy and physiology of eye create barriers like blinking which leads to the poor retention time and penetration of drug moiety. Some conventional ocular drug delivery systems show shortcomings such as enhanced pre-corneal elimination, high variability in efficiency, and blurred vision. To overcome these problems, several novel drug delivery systems such as liposomes, nanoparticles, hydrogels, and in situ gels have been developed. In situ-forming hydrogels are liquid upon instillation and undergo phase transition in the ocular cul-de-sac to form viscoelastic gel and this provides a response to environmental changes. In the past few years, an impressive number of novel temperature, pH, and ion-induced in situ-forming systems have been reported for sustain ophthalmic drug delivery. Each system has its own advantages and drawbacks. Thus, a combination of two drug delivery systems, i.e., nanoparticles and in situ gel, has been developed which is known as nanoparticle laden in situ gel. This review describes every aspects of this novel formulation, which present the readers an exhaustive detail and might contribute to research and development.

  15. In situ Measurements of Phytoplankton Fluorescence Using Low Cost Electronics

    Directory of Open Access Journals (Sweden)

    Dana L. Wright

    2013-06-01

    Full Text Available Chlorophyll a fluorometry has long been used as a method to study phytoplankton in the ocean. In situ fluorometry is used frequently in oceanography to provide depth-resolved estimates of phytoplankton biomass. However, the high price of commercially manufactured in situ fluorometers has made them unavailable to some individuals and institutions. Presented here is an investigation into building an in situ fluorometer using low cost electronics. The goal was to construct an easily reproducible in situ fluorometer from simple and widely available electronic components. The simplicity and modest cost of the sensor makes it valuable to students and professionals alike. Open source sharing of architecture and software will allow students to reconstruct and customize the sensor on a small budget. Research applications that require numerous in situ fluorometers or expendable fluorometers can also benefit from this study. The sensor costs US$150.00 and can be constructed with little to no previous experience. The sensor uses a blue LED to excite chlorophyll a and measures fluorescence using a silicon photodiode. The sensor is controlled by an Arduino microcontroller that also serves as a data logger.

  16. Nanoparticles laden in situ gel for sustained ocular drug delivery

    Directory of Open Access Journals (Sweden)

    Himanshu Gupta

    2013-01-01

    Full Text Available Proper availability of drug on to corneal surface is a challenging task. However, due to ocular physiological barriers, conventional eye drops display poor ocular bioavailability of drugs (< 1%. To improve precorneal residence time and ocular penetration, earlier our group developed and evaluated in situ gel and nanoparticles for ocular delivery. In interest to evaluate the combined effect of in situ gel and nanoparticles on ocular retention, we combined them. We are the first to term this combination as "nanoparticle laden in situ gel", that is, poly lactic co glycolic acid nanoparticle incorporated in chitosan in situ gel for sparfloxacin ophthalmic delivery. The formulation was tested for various physicochemical properties. It showed gelation pH near pH 7.2. The observation of acquired gamma camera images showed good retention over the entire precorneal area for sparfloxacin nanoparticle laden in situ gel (SNG as compared to marketed formulation. SNG formulation cleared at a very slow rate and remained at corneal surface for longer duration as no radioactivity was observed in systemic circulation. The developed formulation was found to be better in combination and can go up to the clinical evaluation and application.

  17. Management of Adenocarcinoma In Situ of Cervix in Pregnancy

    Directory of Open Access Journals (Sweden)

    Alireza Abidi

    2008-03-01

    Full Text Available Adenocarcinoma in situ is one of the premalignant lesions of the cervix and its incidence is believed to be increasing while the pathogenesis of the disease is not clearly understood. Management of Adenocarcinoma in situ (AIS unlike carcinoma in situ (CIS has not been clearly described in the current literature. Here we describe conservative management and serial colposcopy of two pregnant women with adenocarcinoma in situ of the cervix. Both of the cases were diagnosed initially with abnormal Pap smears and were confirmed by colposcopic directed biopsy. None of the patients agreed with any invasive procedure during pregnancy and both of them were followed with serial colposcopy. None of the lesions showed any evidence of progression. All cases underwent cold knife cone biopsies in their postpartum period. Hysterectomy as the final treatment has been done in both cases with no evidence of progression of the disease during pregnancy. We concluded that adenocarcinoma in situ of the cervix during pregnancy could be managed conservatively with definite treatment postponed till after delivery.

  18. Rapid in situ detection of chromosome 21 by PRINS technique

    Energy Technology Data Exchange (ETDEWEB)

    Pellestor, F.; Girardet, A.; Andreo, B. [CNRS UPR 9008, Montpellier (France)] [and others

    1995-05-08

    The {open_quotes}PRimed IN Situ labeling{close_quotes} (PRINS) method is an interesting alternative to in situ hybridization for chromosomal detection. In this procedure, chromosome labeling is performed by in situ annealing of specific oligonucleotide primers, followed by primer elongation by a Taq polymerase in the presence of labeled nucleotides. Using this process, we have developed a simple and semi-automatic method for rapid in situ detection of human chromosome 21. The reaction was performed on a programmable temperature cycler, with a chromosome 21 specific oligonucleotide primer. Different samples of normal and trisomic lymphocytes and amniotic fluid cells were used for testing the method. Specific labeling of chromosome 21 was obtained in both metaphases and interphase nuclei in a 1 hour reaction. The use of oligonucleotide primer for in situ labeling overcomes the need for complex preparations of specific DNA probes. The present results demonstrate that PRINS may be a simple and reliable technique for rapidly detecting aneuploidies. 18 refs., 1 fig.

  19. Development of an analytical model for the determination of {sup 60}Co in aqueous samples by atomic absorption and gamma spectrometry techniques; Elaboracion de un modelo analitico para la determinacion de {sup 60}Co en muestras acuosas mediante tecnicas de absorcion atomica y espectrometria gamma

    Energy Technology Data Exchange (ETDEWEB)

    Solis A, N. A.

    2015-07-01

    The applications of the nuclear energy in industry and medicine generate radioactive wastes that must be isolated and confined in order to limit its spread in the biosphere. These types of wastes are generated in hospitals, industry, research centers and nuclear power plants (during de fuel cycle). The radioactive elements (radionuclides) cannot be destroyed by any known method, either chemical or mechanical. Its final destruction is produced by radioactive decay, which makes them stable isotopes, or nuclear transmutation being bombarded with atomic particles. Consequently, the radioactive waste management is to control the radioactive discharges and reduce to tolerable limits, eliminating of effluents and wastes the radionuclides of interest, concentrating them so they can be stored or evacuated so that later not appear in dangerous concentration in the biosphere. In Mexico, the main generators of radioactive wastes are the nuclear power plant of Laguna Verde in Veracruz, Hospitals of the public and private sector, in addition Instituto Nacional de Investigaciones Nucleares (ININ) some institutes and facilities of the UNAM and Instituto Politecnico Nacional (IPN) and industries among others. The aqueous radioactive wastes, particularly those from the nuclear power plants contain traces of cobalt-60. Currently there is no model or analytical technique for the separation of this radionuclide, so it became necessary to develop an analytical model for separation and facilitate their disposal. In this paper was shown that atomic absorption and gamma spectrometry techniques can separate the active concentration of the inactive, which is important because the total concentration can be associated through direct relationships with the wear of metal parts of the nuclear reactor, since the metal alloys of the same reactor containing a fraction of cobalt. Also this analytical and mathematical model that can be reproducible and applicable to full sets of samples and that this

  20. High energy resolution and high count rate gamma spectrometry measurement of primary coolant of generation 4 sodium-cooled fast reactor; Spectrometrie gamma haute resolution et hauts taux de comptage sur primaire de reacteur de type generation 4 au sodium liquide

    Energy Technology Data Exchange (ETDEWEB)

    Coulon, R.

    2010-11-10

    Sodium-cooled Fast Reactors are under development for the fourth generation of nuclear reactor. Breeders reactors could gives solutions for the need of energy and the preservation of uranium resources. An other purpose is the radioactive wastes production reduction by transmutation and the control of non-proliferation using a closed-cycle. These thesis shows safety and profit advantages that could be obtained by a new generation of gamma spectrometry system for SFR. Now, the high count rate abilities, allow us to study new methods of accurate power measurement and fast clad failure detection. Simulations have been done and an experimental test has been performed at the French Phenix SFR of the CEA Marcoule showing promising results for these new measurements. (author) [French] Les reacteurs a neutrons rapides refroidis au sodium sont en developpement en vue d'assurer une quatrieme generation de reacteurs repondant a la demande energetique, tout en assurant la preservation des ressources d'uranium par un fonctionnement en surgenerateur. L'objectif de la filiere est egalement d'ameliorer la gestion de la radiotoxicite des dechets produits par transmutation des actinides mineurs et de controler la non-proliferation par un fonctionnement en cycle ferme. Une instrumentation de surveillance et de controle de ce type de reacteur a ete etudiee dans cette these. La spectrometrie gamma de nouvelle generation permet, par les hauts taux de traitement aujourd'hui accessibles, d'envisager de nouvelles approches pour suivre avec une precision accrue la puissance neutronique et de detecter plus precocement des ruptures de gaine combustible. Des simulations numeriques ont ete realisees et une campagne d'essai a ete menee a bien sur le reacteur Phenix de Marcoule. Des perspectives prometteuses ont ete mises en exergue pour ces deux problematiques

  1. Looking for a bulk point

    CERN Document Server

    Maldacena, Juan; Zhiboedov, Alexander

    2015-01-01

    We consider Lorentzian correlators of local operators. In perturbation theory, singularities occur when we can draw a position-space Landau diagram with null lines. In theories with gravity duals, we can also draw Landau diagrams in the bulk. We argue that certain singularities can arise only from bulk diagrams, not from boundary diagrams. As has been previously observed, these singularities are a clear diagnostic of bulk locality. We analyze some properties of these perturbative singularities and discuss their relation to the OPE and the dimensions of double-trace operators. In the exact nonperturbative theory, we expect no singularity at these locations. We prove this statement in 1+1 dimensions by CFT methods.

  2. In situ soft XAS study on nickel-based layered cathode material at elevated temperatures: A novel approach to study thermal stability

    Science.gov (United States)

    Yoon, Won-Sub; Haas, Otto; Muhammad, Shoaib; Kim, Hyunchul; Lee, Wontae; Kim, Donghwi; Fischer, Daniel A.; Jaye, Cherno; Yang, Xiao-Qing; Balasubramanian, Mahalingam; Nam, Kyung-Wan

    2014-10-01

    Tracking thermally induced reactions has always been challenging for electrode materials of electrochemical battery systems. Traditionally, a variety of calorimetric techniques and in situ XRD at elevated temperatures has been used to evaluate the thermal stability of electrode materials. These techniques are capable of providing variations in heat capacity, mass and average bulk composition of materials only. Herein, we report investigation of thermal characteristics of Li0.33Ni0.8Co0.15Al0.05O2 by using in situ soft XAS measurements in combination with XRD. Fluorescence yield and partial electron yield measurements are used simultaneously to obtain element selective surface and bulk information. Fluorescence yield measurements reveal no energy change of the absorption peak and thus no valence state change in the bulk. However, electron yield measurements indicate that NiO-type rock salt structure is formed at the surface at temperatures above 200°C while no evidence for a surface reaction near Co sites in investigated temperature range is found. These results clearly show that in situ soft XAS can give a unique understanding of the role of each element in the structural transformation under thermal abuse offering a useful guidance in developing new battery system with improved safety performance.

  3. Bulk nano-crystalline alloys

    OpenAIRE

    T.-S. Chin; Lin, C. Y.; Lee, M.C.; R.T. Huang; S. M. Huang

    2009-01-01

    Bulk metallic glasses (BMGs) Fe–B–Y–Nb–Cu, 2 mm in diameter, were successfully annealed to become bulk nano-crystalline alloys (BNCAs) with α-Fe crystallite 11–13 nm in size. A ‘crystallization-and-stop’ model was proposed to explain this behavior. Following this model, alloy-design criteria were elucidated and confirmed successful on another Fe-based BMG Fe–B–Si–Nb–Cu, 1 mm in diameter, with crystallite sizes 10–40 nm. It was concluded that BNCAs can be designed in general by the proposed cr...

  4. Microstructure analysis of laboratory and in-situ compacted silts

    Directory of Open Access Journals (Sweden)

    Russo Giacomo

    2016-01-01

    Full Text Available The paper presents and discusses some results of an experimental research aimed at analysing the influence of compaction variables (w and energy and method on the resulting microstructure of a compacted silty soil. In particular, the experimental data here discussed allow to compare the microstructure induced by different dynamic compaction techniques, comparing that characterising specimens obtained by two laboratory methods (Proctor standard and Harvard and that of samples compacted in-situ during the construction of an embankment built for river regimentation purposes. Both undisturbed and disturbed samples have been retrieved from the embankment, the latter one with the purpose of collecting the soil subsequently used for laboratory compaction. Microstructural analyses (SEM, MIP performed on laboratory and in-situ compacted samples evidenced a substantial similarity of the texture induced by the various compaction techniques, highlighting that laboratory compaction is suitable to provide soil samples representative of earth in-situ compacted soil.

  5. Characteristics of in situ stress field at Qingshui coal mine

    Institute of Scientific and Technical Information of China (English)

    Yang Xiaojie; Pang Jiewen; Lou Haopeng; Fan Lipeng

    2015-01-01

    In this study, the characteristics of geological structure at Qingshui coal mine were analyzed. And the hollow inclusion strain cell overcoring method was used to obtain the in situ stress. The effect of in situ stress on the stability of soft rock roadway was analyzed. The results show that the maximum principal stress is in the horizontal direction with a northeast orientation and has a value of about 1.2–1.9 times larger than gravity; the right side of roadway roof and floor is easily subject to serious deformation and failure, and the in situ stress is found to be a major factor. This paper presents important information for developing countermeasures against the large deformation of the soft rock roadway at Qingshui coal mine.

  6. Detector calibration for in-situ gamma ray spectrometry

    CERN Document Server

    Balea, G

    2002-01-01

    The power in the technique of in-situ spectrometry lies in the fact that a detector placed on ground measures gamma radiation from sources situated over an area of several hundred square meters. The 'field of view' for the detector would be larger for high energy radiation sources and for sources closer to the soil surface. In contrast, a soil sample would represent an area of a few tens of hundreds of square centimeters. In practice, an effective characterization of a site would involve in-situ gamma ray spectrometry in conjunction with soil sampling. As part of an overall program, in-situ gamma ray spectrometry provides a means to assess the degree of contamination in areas during the course of operations in the field, thus guiding the investigator on where to collect samples. It can also substantially reduce the number of samples need to be collected and subsequently analyzed. (author)

  7. Review on Fabrication Methods of in situ Metal Matrix Composites

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper deals with a series of novel processing techniques based on the in situ production of metal matrix composites (MMCs). In situ techniques involve a chemical reaction resulting in the formation of a very fine and thermodynamically stable reinforcing ceramic phase within a metal matrix. As a result, this provides thermodynamic compatibility at the matrix-reinforcement interface. The reinforcement surfaces are also likely to be free of contamination and, therefore, a stronger matrix-dispersion bond can be achieved. Some of these technologies including DIMOXTM, XD, PRIMEXTM, reactive gas infiltration, high-temperature self-propagating synthesis (SHS), and liquid-solid, or solid-gas-liquid reactions as well as plasma in situ MMCs are expressed in this paper.

  8. Development of portable HPGe spectrometer for in situ measurements

    Directory of Open Access Journals (Sweden)

    Kail Artjoms

    2015-01-01

    Full Text Available In situ applications require a very high level of portability of high-resolution spectrometric equipment. Usage of HPGe detectors for radioactivity measurements in the environment or for nuclear safeguard applications, to combat illicit trafficking of nuclear materials or uranium and plutonium monitoring in nuclear wastes, has become a norm in the recent years. Portable HPGe-based radionuclide spectrometer with electrical cooling has lately appeared on the market for in situ applications. At the same time deterioration of energy resolution associated with vibrations produced by cryocooler or high weight of the instrument, short time of autonomous operation and high price of these spectrometers are limiting their usage in many cases. In this paper we present development results of ultra compact hand held all-in-one spectrometer for in situ measurements based on HPGe detector cooled by liquid nitrogen without listing the above disadvantages.

  9. In Situ Atom Probe Deintercalation of Lithium-Manganese-Oxide.

    Science.gov (United States)

    Pfeiffer, Björn; Maier, Johannes; Arlt, Jonas; Nowak, Carsten

    2017-01-30

    Atom probe tomography is routinely used for the characterization of materials microstructures, usually assuming that the microstructure is unaltered by the analysis. When analyzing ionic conductors, however, gradients in the chemical potential and the electric field penetrating dielectric atom probe specimens can cause significant ionic mobility. Although ionic mobility is undesirable when aiming for materials characterization, it offers a strategy to manipulate materials directly in situ in the atom probe. Here, we present experimental results on the analysis of the ionic conductor lithium-manganese-oxide with different atom probe techniques. We demonstrate that, at a temperature of 30 K, characterization of the materials microstructure is possible without measurable Li mobility. Also, we show that at 298 K the material can be deintercalated, in situ in the atom probe, without changing the manganese-oxide host structure. Combining in situ atom probe deintercalation and subsequent conventional characterization, we demonstrate a new methodological approach to study ionic conductors even in early stages of deintercalation.

  10. Extreme Spectroscopy: In situ nuclear materials behavior from optical data

    Energy Technology Data Exchange (ETDEWEB)

    Guimbretiere, G.; Canizares, A.; Raimboux, N.; Omnee, R.; Duval, F.; Ammar, M.R.; Simon, P. [CNRS - UPR3079 CEMHTI, Universite d' Orleans, 45071Orleans cedex 2 (France); Desgranges, L.; Mohun, R. [CEA, DEN, DEC, F-13108 Saint-Paul-Lez-Durance (France); Jegou, C.; Magnin, M. [CEA/DTCD/SECM/LMPA, Marcoule 30207 Bagnols Sur Ceze (France); Clavier, N.; Dacheux, N. [ICSM-UMR5257 CEA/CNRS/UM2/ENSCM, Marcoule, BP17171, 30207 Bagnols sur Ceze (France)

    2015-07-01

    In the nuclear industry, materials are regularly exposed to high temperature or/and irradiation and a better knowledge and understanding of their behavior under such extreme conditions is a key-point for improvements and further developments. Nowadays, Raman spectroscopy begins to be well known as a promising technique in the post mortem and remote characterization of nuclear materials exposed to extreme conditions. On this topic, at ANIMMA 2013 conference, we have presented some results about its implementation in the study of model or real nuclear fuel. However, the strength of Raman spectroscopy as in situ characterization tool is mainly its ability to be implemented remotely through optical fibers. Aware of this, implementation of other optical techniques can be considered in order to gain information not only on the structural dynamics of materials but also on the electronic charge carrier populations. In this paper, we propose to present our last advances in Raman characterization of nuclear materials and enlarge to the in situ use of complementary optical spectroscopies. Emphasis will be made on the information that can be gained to the behavior of the model fuel depleted UO{sub 2} under extreme conditions of high temperature and ionic irradiation: - In Situ Raman identification of the radiolysis alteration products of UO{sub 2} in contact with water under ionic irradiation. - In Situ Raman recording of the damaged dynamic of UO{sub 2} under inert atmosphere. - In Situ Raman and photo-luminescence study of virgin and damaged UO2 at high temperature. - In Situ study of electronic charge carriers' behavior in U{sub x}Th{sub 1-x}O{sub 2} solid solutions by mean of Iono- and Thermo- luminescence under and post- ionic irradiation. (authors)

  11. Open Source AV solution supporting In Situ Simulation

    DEFF Research Database (Denmark)

    Krogh, Kristian; Pociunas, Gintas; Dahl, Mads Ronald

    the software to meet our expectations for a portable AV system for VAD. The system would make use of “off the shelf” hardware components which are widely available and easily replaced or expanded. The developed AV software and coding is contracted to be available as Copyleft Open Source to ensure low cost...... a stable AV software that has be developed and implemented for an in situ simulation initiative. This version (1.3) is the first on released as Open Source (Copyleft) software (see QR tag). We have found that it is possible to deliver multi-camera video assisted debriefing in a mobile, in situ simulation...

  12. In situ and operando transmission electron microscopy of catalytic materials

    DEFF Research Database (Denmark)

    Crozier, Peter A.; Hansen, Thomas Willum

    2015-01-01

    Catalytic nanomaterials play a major role in chemical conversions and energy transformations. Understanding how materials control and regulate surface reactions is a major objective for fundamental research on heterogeneous catalysts. In situ environmental transmission electron microscopy (ETEM......) is a powerful technique for revealing the atomic structures of materials at elevated temperatures in the presence of reactive gases. This approach can allow the structure-reactivity relations underlying catalyst functionality to be investigated. Thus far, ETEM has been limited by the absence of in situ...

  13. In-situ ALD growth of hafnium oxide films

    Energy Technology Data Exchange (ETDEWEB)

    Karavaev, Konstantin; Tallarida, Massimo; Schmeisser, Dieter [Brandenburgische Technische Universitaet Cottbus (Germany). Angewandte Physik - Sensorik; Zschech, Ehrenfried [AMD Saxony LLC and Co. KG, Center for Complex Analysis, Dresden (Germany)

    2008-07-01

    We report on a novel system for in-situ atomic layer growth (ALD) of high-k dielectric films. First results were obtained for Hf-oxide samples by using Hf-tetrachloride as precursor and water as oxidizer. We compare the photoelectron spectra of Si 2p, O 1s and Hf 4f of our in-situ prepared films with samples (ex-situ) prepared by industrial ALD reactors and discuss similarities and differences observed in the core level spectra of the various samples by considering the different growth conditions.

  14. DEBIE - first standard in-situ debris monitoring instrument

    Science.gov (United States)

    Kuitunen, J.; Drolshagen, G.; McDonnell, J. A. M.; Svedhem, H.; Leese, M.; Mannermaa, H.; Kaipiainen, M.; Sipinen, V.

    2001-10-01

    Objects larger than a few centimetres can be tracked with radar or with optical telescopes. The population of smaller particles can only be investigated by the analysis of retrieved spacecraft and passive detectors or by in-situ monitors in orbit. Patria Finavitec together with UniSpace Kent have developed the DEBIE (DEBris In-orbit Evaluator) instrument to determine the parameters of sub-millimetre sized space debris and micrometeoroids in-situ by their impact with a detecting surface. The main goal has been to develop an economical and low-resource instrument, easy to integrate into any spacecraft, while providing reliable real-time data for space debris modelling.

  15. In-Situ Investigation of Advanced Structural Coatings and Composites

    Science.gov (United States)

    Ustundag, Ersan

    2003-01-01

    The premise of this project is a comprehensive study that involves the in-situ characterization of advanced coatings and composites by employing both neutron and x-ray diffraction techniques in a complementary manner. The diffraction data would then be interpreted and used in developing or validating advanced micromechanics models with life prediction capability. In the period covered by this report, basic work was conducted to establish the experimental conditions for various specimens and techniques. In addition, equipment was developed that will allow the in-situ studies under a range of conditions (stress, temperature, atmosphere, etc.).

  16. Continued Development of in Situ Geochronology for Planetary Missions

    Science.gov (United States)

    Devismes, D.; Cohen, B. A.

    2015-01-01

    The instrument 'Potassium (K) Argon Laser Experiment' (KArLE) is developed and designed for in situ absolute dating of rocks on planetary surfaces. It is based on the K-Ar dating method and uses the Laser Induced Breakdown Spectroscopy - Laser Ablation - Quadrupole Mass Spectrometry (LIBSLA- QMS) technique. We use a dedicated interface to combine two instruments similar to SAM of Mars Science Laboratory (for the QMS) and ChemCam (for the LA and LIBS). The prototype has demonstrated that KArLE is a suitable and promising instrument for in situ absolute dating.

  17. In Situ burning of Arctic marine oil spills

    DEFF Research Database (Denmark)

    Fritt-Rasmussen, Janne

    Oil spills in ice filled and Arctic waters pose other challenges for oil spill response compared to open and temperate waters. In situ burning has been proven to be an effective oil spill response method for oil spills in ice filled waters. This thesis presents results from laboratory and field...... experiments where the ignitability of oil spill as a function of oil type and weathering conditions (time/ice) was tested. The results show that the composition of the oil and the ice cover is important for the in situ burning time-window. The results were used to develop an algorithm that was implemented...

  18. In-situ EELS and UPS measurements on HfO{sub 2} ALD layers

    Energy Technology Data Exchange (ETDEWEB)

    Michling, Marcel; Tallarida, Massimo; Kolanek, Krzysztof; Schmeisser, Dieter [Brandenburgische Technische Universitaet Cottbus, Angewandte Physik/Sensorik, Cottbus (Germany)

    2010-07-01

    In this contribution we report on our in-situ cycle-by-cycle (up to 10 cycles) investigations of the HfO{sub 2} ALD process using the methods of EELS and UPS. We used TDMA-Hf as a precursor and p-type Si wafer with natural oxide as the substrate. The EELS measurements were done with a primary energy of 52.5 eV and the UPS measurements with He I (21.218 eV). The change in the onset of the loss function is readily observed. Already after two cycles the value approach to the bulk value of HfO{sub 2}. Upon ALD growth there is a remarkable decrease in the intensity of states within the gap. They are rather smooth and saturate after 10 cycles. With UPS we follow the variation of the VB onset and changes in the secondary electron onset. We summarize our data in a band diagram not based on bulk values but on cycle dependent quantities. With these cycle-by-cycle experiments we study the initial growth of HfO{sub 2} especially in the very first cycles.

  19. Longitudinal bulk acoustic mass sensor

    DEFF Research Database (Denmark)

    Hales, Jan Harry; Teva, Jordi; Boisen, Anja

    2009-01-01

    A polycrystalline silicon longitudinal bulk acoustic cantilever is fabricated and operated in air at 51 MHz. A mass sensitivity of 100 Hz/fg (1 fg=10(-15) g) is obtained from the preliminary experiments where a minute mass is deposited on the device by means of focused ion beam. The total noise i...

  20. The Universe With Bulk Viscosity

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Exact solutions for a model with variable G, A and bulk viscosity areobtained. Inflationary solutions with constant (de Sitter-type) and variable energydensity are found. An expanding anisotropic universe is found to isotropize duringits expansion but a static universe cannot isotropize. The gravitational constant isfound to increase with time and the cosmological constant decreases with time asAo∝t-2.

  1. A novel in situ-formed hydrogel wound dressing by the photocross-linking of a chitosan derivative.

    Science.gov (United States)

    Lu, Guozhong; Ling, Kai; Zhao, Peng; Xu, Zhenghong; Deng, Cao; Zheng, Hua; Huang, Jin; Chen, Jinghua

    2010-01-01

    In situ photopolymerized hydrogel dressings create minimally invasive methods that offer advantages over the use of preformed dressings such as conformability in any wound bed, convenience of application, and improved patient compliance and comfort. Here, we report an in situ-formed hydrogel membrane through ultraviolet cross-linking of a photocross-linkable azidobenzoic hydroxypropyl chitosan aqueous solution. The hydrogel membrane is stable, flexible, and transparent, with a bulk network structure of smoothness, integrity, and density. Fluid uptake ability, water vapor transmission rate, water retention, and bioadhesion of the thus resulted hydrogel membranes (0.1 mm thick) were determined to range from 97.0-96.3%, 2,934-2,561 g/m(2)/day, 36.69-22.94% (after 6 days), and 4.8-12.3 N/cm(2), respectively. These data indicate that the hydrogel membrane can maintain a long period of moist environment over the wound bed for enhancing reepithelialization. Specifically, these properties of the hydrogel membrane were controllable to some extent, by adjusting the substitution degree of the photoreactive azide groups. The hydrogel membrane also exhibited barrier function, as it was impermeable to bacteria but permeable to oxygen. In vitro experiments using two major skin cell types (dermal fibroblast and epidermal keratinocyte) revealed the hydrogel membrane have neither cytotoxicity nor an effect on cell proliferation. Taken together, the in situ photocross-linked azidobenzoic hydroxypropyl chitosan hydrogel membrane has a great potential in the management of wound healing and skin burn.

  2. Investigation of the thermal stability of phosphotungstic Wells-Dawson heteropoly-acid through in situ Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Matkovic, Silvana Raquel, E-mail: matkovic@quimica.unlp.edu.ar [Centro de Investigacion y Desarrollo en Ciencias Aplicadas-Dr. Jorge J. Ronco. U.N.L.P., CONICET, CCT La Plata. Calle 47 N 257, B1900AJK La Plata, Buenos Aires (Argentina); Briand, Laura Estefania [Centro de Investigacion y Desarrollo en Ciencias Aplicadas-Dr. Jorge J. Ronco. U.N.L.P., CONICET, CCT La Plata. Calle 47 N 257, B1900AJK La Plata, Buenos Aires (Argentina); Banares, Miguel Angel [Laboratorio de Espectroscopia Catalitica, Instituto de Catalisis y Petroleoquimica, CSIC. Marie Curie 2, Cantoblanco, E-28049 Madrid (Spain)

    2011-11-15

    Highlights: {yields} Insitu Raman is used to monitor the thermal stability of Wells Dawson heteropolyacid. {yields} TP-Raman follows the gradual dehydration and the effect on the secondary structure. {yields} Wells-Dawson heteropolyacid does not decompose into Keggin and WO{sub 3} units below 600{sup o}C -- Abstract: The present investigation applies laser Raman spectroscopy under in situ conditions to obtain insights on the effect of the temperature on the molecular structure of the bulk phosphotungstic Wells-Dawson heteropoly-acid H{sub 6}P{sub 2}W{sub 18}O{sub 62}.xH{sub 2}O (HPA). The in situ temperature-programmed studies followed the evolution of phosphotungstic Wells-Dawson and Keggin heteropoly-acids along with tungsten trioxide under controlled atmosphere and temperature. The spectroscopic investigation of the Wells-Dawson HPA demonstrated that in situ Raman spectroscopy is a suitable technique to follow the effect of a gradual dehydration on the secondary structure of such a complex structure. Moreover, the absence of the signals belonging either to the Keggin or WO{sub 3} phases provides further evidence that the phosphotungstic heteropolyanion does not decomposes towards those materials at temperatures below 600 {sup o}C.

  3. Natural Oxidant Demand Variability, Potential Controls, and Implications for in Situ, Oxidation-Based Remediation of Contaminated Groundwater

    Science.gov (United States)

    Dettmer, A.; Cruz, S.; Dungan, B.; Holguin, F. O.; Ulery, A. L.; Hunter, B.; Carroll, K. C.

    2014-12-01

    Naturally occurring reduced species associated with subsurface materials can impose a significant natural oxidant demand (NOD), which is the bulk consumption of oxidants by soil water, minerals, and organic matter. Although injection of oxidants has been used for chemical transformation of organic contaminants, NOD represents a challenge for the in-situ delivery of oxidants as a remediation alternative. Co-injection of complexation agents with oxidants has been proposed to facilitate the delivery of oxidants for in situ chemical oxidation remediation of contaminated groundwater. This study investigates variability of NOD for different oxidants and sediments. The effect of the addition of various complexation agents, including EDTA, tween 80, hydroxypropyl-beta-cyclodextrin (HPCD), humic acid, and four generations of poly(amidoamine) (PAMAM) dendrimers, on the NOD was also examined. NOD was measured for a clay loam (collected from Air Force Plant 44 in Tucson, AZ). Varying amounts of biosolids were mixed with subsamples of the clay loam to create three additional reference soils in order to study the effect of organic matter and other soil characteristics on the NOD. Bench-scale laboratory experiments were conducted to determine the NOD for various oxidants, using the four soils, and replicated with and without various delivery agents. Measured NOD showed variability for each soil and oxidant composition. Additionally, significant differences were observed in NOD with the addition of delivery agents. The results support the elucidation of potential controls over NOD and have implications for in situ, oxidation-based remediation of contaminated groundwater.

  4. Diagnosis of In Situ Metabolic State and Rates of Microbial Metabolism During In Situ Uranium Bioremediation with Molecular Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Lovley, Derek R. [University of Massachusetts, Amherst

    2012-11-28

    The goal of these projects was to develop molecule tools to tract the metabolic activity and physiological status of microorganisms during in situ uranium bioremediation. Such information is important in able to design improved bioremediation strategies. As summarized below, the research was highly successful with new strategies developed for estimating in situ rates of metabolism and diagnosing the physiological status of the predominant subsurface microorganisms. This is a first not only for groundwater bioremediation studies, but also for subsurface microbiology in general. The tools and approaches developed in these studies should be applicable to the study of microbial communities in a diversity of soils and sediments.

  5. In situ XAS of the solvothermal decomposition of dithiocarbamate complexes

    NARCIS (Netherlands)

    Islam, H.-U.; Roffey, A.; Hollingsworth, N.; Catlow, R.; Wolthers, M.; de Leeuw, N.H.; Bras, W.; Sankar, G.; Hogarth, G.

    2012-01-01

    An in situ XAS study of the solvothermal decomposition of iron and nickel dithiocarbamate complexes was performed in order to gain understanding of the decomposition mechanisms. This work has given insight into the steps involved in the decomposition, showing variation in reaction pathways between t

  6. Electromechanical instabilities of thermoplastics: Theory and in situ observation

    OpenAIRE

    Wang, Qiming; Niu, Xiaofan; Pei, Qibing; Michael D. Dickey; Zhao, Xuanhe

    2012-01-01

    Thermoplastics under voltages are used in diverse applications ranging from insulating cables to organic capacitors. Electromechanical instabilities have been proposed as a mechanism that causes electrical breakdown of thermoplastics. However, existing experiments cannot provide direct observations of the instability process, and existing theories for the instabilities generally assume thermoplastics are mechanically unconstrained. Here, we report in situ observations of electromechanical ins...

  7. In-situ remediation system for groundwater and soils

    Science.gov (United States)

    Corey, J.C.; Kaback, D.S.; Looney, B.B.

    1991-01-01

    The present invention relates to a system for in-situ remediation of contaminated groundwater and soil. In particular the present invention relates to stabilizing toxic metals in groundwater and soil. The United States Government has rights in this invention pursuant to Contract No. DE-AC09-89SR18035 between the US Department of Energy and Westinghouse Savannah River Company.

  8. Ultrasensitive in situ visualization of active glucocerebrosidase molecules

    NARCIS (Netherlands)

    Witte, Martin D.; Kallemeijn, Wouter W.; Aten, Jan; Li, Kah-Yee; Strijland, Anneke; Donker-Koopman, Wilma E.; Nieuwendijk, Adrianus M.C.H. van den; Bleijlevens, Boris; Kramer, Gertjan; Florea, Bogdan I.; Hooibrink, Berend; Hollak, Carla E.M.; Ottenhoff, Roelof; Boot, Rolf G.; Marel, Gijsbert A. van der; Overkleeft, Herman S.; Aerts, Johannes M.F.G.

    2010-01-01

    Deficiency of glucocerebrosidase (GBA) underlies Gaucher disease, a common lysosomal storage disorder. Carriership for Gaucher disease has recently been identified as major risk for parkinsonism. Presently, no method exists to visualize active GBA molecules in situ. We here report the design, synthe

  9. Mixing and In situ product removal in micro-bioreactors

    NARCIS (Netherlands)

    Li, X.

    2009-01-01

    Summary Of the thesis :’ Mixing and In-situ product removal in micro bioreactors’ by Xiaonan Li The work presented in this thesis is a part of a large cluster project, which was formed between DSM, Organon, Applikon and two university groups (TU Delft and University of Twente), under the ACTS and

  10. Repurposing CRISPR/Cas9 for in situ functional assays

    NARCIS (Netherlands)

    Malina, Abba; Mills, John R; Cencic, Regina; Yan, Yifei; Fraser, James; Schippers, Laura M; Paquet, Marilène; Dostie, Josée; Pelletier, Jerry

    2013-01-01

    RNAi combined with next-generation sequencing has proven to be a powerful and cost-effective genetic screening platform in mammalian cells. Still, this technology has its limitations and is incompatible with in situ mutagenesis screens on a genome-wide scale. Using p53 as a proof-of-principle target

  11. ENGINEERING ISSUE: IN SITU BIOREMEDIATION OF CONTAMINATED UNSATURATED SUBSURFACE SOILS

    Science.gov (United States)

    An emerging technology for the remediation of unsaturated subsurface soils involves the use of microorganisms to degrade contaminants which are present in such soils. Understanding the processes which drive in situ bioremediation, as well as the effectiveness and efficiency of th...

  12. Ortho lithiation-in situ borylation of substituted morpholine benzamides

    DEFF Research Database (Denmark)

    Cederbalk, Anna; Lysén, Morten; Kehler, Jan

    2016-01-01

    Morpholine amides are cheap and safe alternative to Weinreb amides as acylating agents of organometallic species. Herein, the in-situ lithiation/borylation of 18 ortho- meta- and para-substituted morpholine benzamides has been investigated. 10 of the 18 substrates provided the desired boronic...

  13. Crystal Transformation of Nylon 11 Using in situ WAXD

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    a Form Nylon 11 films were found to exist a non-linear transformation at 70oC during the heating process using in situ WAXD. The a Form disappeared but d form appeared when the temperature was higher 70℃.

  14. Simulating realistic imaging conditions for in situ liquid microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Welch, David A., E-mail: dawelch@ucdavis.edu [Department of Chemical Engineering and Materials Science, University of California, Davis, CA (United States); Faller, Roland [Department of Chemical Engineering and Materials Science, University of California, Davis, CA (United States); Evans, James E. [Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, Richland, WA (United States); Browning, Nigel D. [Pacific Northwest National Laboratory, Fundamental Computational Sciences Directorate, Richland, WA (United States)

    2013-12-15

    In situ transmission electron microscopy enables the imaging of biological cells, macromolecular protein complexes, nanoparticles, and other systems in a near-native environment. In order to improve interpretation of image contrast features and also predict ideal imaging conditions ahead of time, new virtual electron microscopic techniques are needed. A technique for virtual fluid-stage high-angle annular dark-field scanning transmission electron microscopy with the multislice method is presented that enables the virtual imaging of model fluid-stage systems composed of millions of atoms. The virtual technique is exemplified by simulating images of PbS nanoparticles under different imaging conditions and the results agree with previous experimental findings. General insight is obtained on the influence of the effects of fluid path length, membrane thickness, nanoparticle position, defocus and other microscope parameters on attainable image quality. - Highlights: • Image simulation has been performed to understand in situ electron microscopy experiments. • Experimentally observed resolution of in situ grown PbS nanoparticles has been virtually reproduced. • General relationships between image resolution and in situ holder design, defocus, and particle size have been determined. • The presented image simulation technique can predict the obtainable resolution of future experiments.

  15. Supernumerary ring chromosome 17 identified by fluorescent in situ hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Fagan, K. [Hunter Area Pathology Service, New South Wales (Australia); Edwards, M. [Western Suburbs Hospital, New South Wales (Australia)

    1997-04-14

    We present a patient with multiple anomalies and severe developmental delay. A small supernumerary ring chromosome was found in 40% of her lymphocyte cells at birth. The origin of the marker chromosome could not be determined by GTG banding, but fluorescent in situ hybridization (FISH) later identified the marker as deriving from chromosome 17. 20 refs., 2 figs., 1 tab.

  16. In situ study on the formation of FeTe

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Wulff, Anders Christian; Yue, Zhao;

    2011-01-01

    The formation of the FeTe compound from a mixture of Fe and Te powders was studied in situ by means of high-energy synchrotron X-ray diffraction. FeTe does not form directly from the starting elements; instead, FeTe2 forms as an intermediate product. During a 2 °C/min heating ramp, Te first reacts...

  17. In-situ strain observation in high power laser cladding

    NARCIS (Netherlands)

    Ocelik, V.; Bosgra, J.; de Hosson, J. Th. M.

    2009-01-01

    The modern experimental technique - so called Digital Image Correlation - is applied during high power laser surface treatments for in-situ observation of displacements and strains near the processing area during and a short time after laser processing. An experimental setup has been designed and te

  18. NASAL IN SITU GEL: A NOVEL DRUG DELIVERY SYSTEM

    Directory of Open Access Journals (Sweden)

    Dhrupesh panchal

    2012-06-01

    Full Text Available Over the past few decades, advances in the in situ gel technologies have spurred development in manymedical and biomedical applications including controlled drug delivery. Many novel in situ gel baseddelivery matrices have been designed and fabricated to fulfill the ever increasing needs of thepharmaceutical and medical fields. In situ gelling systems are liquid at room temperature but undergogelation when in contact with body fluids or change in pH. In situ gel forming drug delivery is a type ofmucoadhesive drug delivery system. The formation of gel depends on factors like temperaturemodulation, pH change, presence of ions and ultraviolet irradiation from which the drug gets released ina sustained and controlled manner. Nasal delivery is a promising drug delivery option where commondrug administrations such as intravenous, intramuscular or oral are inapplicable. Recently, it has beenshown that many drugs have better bioavailability by nasal route than the oral route. This has beenattributed to rich vasculature and a highly permeable structure of the nasal mucosa coupled withavoidance of hepatic first-pass elimination, gut wall metabolism and/or destruction in thegastrointestinal tract. The physiology of the nose presents obstacles but offers a promising route for noninvasivesystemic delivery of numerous therapies and debatably drug delivery route to the brain. Thusthis review focuses on nasal drug delivery, various aspects of nasal anatomy and physiology, nasal drugabsorption mechanisms, various nasal drug delivery systems and their applications in drug delivery.

  19. Testicular carcinoma in situ in subfertile Danish men

    DEFF Research Database (Denmark)

    Olesen, Inge A; Hoei-Hansen, Christina E; Skakkebaek, Niels E

    2007-01-01

    Carcinoma in situ (CIS) testis is the precursor stage for the majority of testicular germ cell tumours (TGCT). Infertility is one of the conditions known to predispose to TGCT, but based on scarce existing data, the prevalence of CIS in this risk group was estimated at only approximately 1...

  20. Adaptation of in-situ microscopy for crystallization processes

    Science.gov (United States)

    Bluma, A.; Höpfner, T.; Rudolph, G.; Lindner, P.; Beutel, S.; Hitzmann, B.; Scheper, T.

    2009-08-01

    In biotechnological and pharmaceutical engineering, the study of crystallization processes gains importance. An efficient analytical inline sensor could help to improve the knowledge about these processes in order to increase efficiency and yields. The in-situ microscope (ISM) is an optical sensor developed for the monitoring of bioprocesses. A new application for this sensor is the monitoring in downstream processes, e.g. the crystallization of proteins and other organic compounds. This contribution shows new aspects of using in-situ microscopy to monitor crystallization processes. Crystals of different chemical compounds were precipitated from supersaturated solutions and the crystal growth was monitored. Exemplified morphological properties and different forms of crystals could be distinguished on the basis of offline experiments. For inline monitoring of crystallization processes, a special 0.5 L stirred tank reactor was developed and equipped with the in-situ microscope. This reactor was utilized to carry out batch experiments for crystallizations of O-acetylsalicyclic acid (ASS) and hen egg white lysozyme (HEWL). During the whole crystallization process, the in-situ microscope system acquired images directly from the crystallization broth. For the data evaluation, an image analysis algorithm was developed and implemented in the microscope analysis software.

  1. AFM cantilever with in situ renewable mercury microelectrode

    NARCIS (Netherlands)

    Schön, Peter; Geerlings, Joël; Tas, Niels; Sarajlic, Edin

    2013-01-01

    We report here first results obtained on a novel, in situ renewable mercury microelectrode integrated into an atomic force microscopy (AFM) cantilever. Our approach is based on a fountain pen probe with appropriate dimensions enabling reversible filling with(nonwetting) mercury under changing the ap

  2. In-Situ Catalytic Fast Pyrolysis Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Biddy, M.; Dutta, A.; Jones, S.; Meyer, A.

    2013-03-01

    This technology pathway case investigates converting woody biomass using in-situ catalytic fast pyrolysis followed by upgrading to gasoline-, diesel-, and jet-range hydrocarbon blendstocks. Technical barriers and key research needs that should be pursued for this pathway to be competitive with petroleum-derived blendstocks have been identified.

  3. In situ spectrophotometric measurement of dissolved inorganic carbon in seawater

    Science.gov (United States)

    Liua, Xuewu; Byrne, Robert H.; Adornato, Lori; Yates, Kimberly K.; Kaltenbacher, Eric; Ding, Xiaoling; Yang, Bo

    2013-01-01

    Autonomous in situ sensors are needed to document the effects of today’s rapid ocean uptake of atmospheric carbon dioxide (e.g., ocean acidification). General environmental conditions (e.g., biofouling, turbidity) and carbon-specific conditions (e.g., wide diel variations) present significant challenges to acquiring long-term measurements of dissolved inorganic carbon (DIC) with satisfactory accuracy and resolution. SEAS-DIC is a new in situ instrument designed to provide calibrated, high-frequency, long-term measurements of DIC in marine and fresh waters. Sample water is first acidified to convert all DIC to carbon dioxide (CO2). The sample and a known reagent solution are then equilibrated across a gas-permeable membrane. Spectrophotometric measurement of reagent pH can thereby determine the sample DIC over a wide dynamic range, with inherent calibration provided by the pH indicator’s molecular characteristics. Field trials indicate that SEAS-DIC performs well in biofouling and turbid waters, with a DIC accuracy and precision of ∼2 μmol kg–1 and a measurement rate of approximately once per minute. The acidic reagent protects the sensor cell from biofouling, and the gas-permeable membrane excludes particulates from the optical path. This instrument, the first spectrophotometric system capable of automated in situ DIC measurements, positions DIC to become a key parameter for in situ CO2-system characterizations.

  4. Acral Lentiginous Melanoma in Situ: A Diagnostic and Management Challenge

    Directory of Open Access Journals (Sweden)

    Hyun Sun Park

    2010-04-01

    Full Text Available Early stage recognition of acral lentiginous melanoma (ALM is important for a better prognosis, but in-depth understanding and proper management of ALM in situ is complicated, because there are only a few reports, probably due to its rarity and diagnostic difficulty. We have reviewed our experience with seven patients who were diagnosed as having ALM in situ and discuss how to accurately diagnose and properly manage these rare lesions. Clinically the lesions showed black to brown discoloration of the nail with Hutchinson’s sign and hyperpigmented macules on the heel with color variegation. All the lesions showed a diffuse lentiginous pattern of melanocytic proliferation with variable level of atypism along the dermoepidermal junction. Dermoscopic findings were available in three and revealed parallel ridge patterns. Confrontation of clinical and histopathologic findings was observed in three, and the lesions were not recognized or diagnosed as ALM in situ in the first place. Excision of the primary lesion with variable operative margin was done as an initial treatment. Recurrence was observed in three patients and one developed invasive ALM and lymph node metastasis. Integration of all available information concerning the clinical presentation, histopathology, and dermoscopic findings is very important and can lead to the best classification for correct diagnosis. Lack of knowledge upon clinical course and optimal margin to control ALM in situ provokes the need for further studies with longer follow up and larger number of cases.

  5. DEMONSTRATION BULLETIN: IN-SITU VACUUM EXRACTION: TERRA VAC, INC.

    Science.gov (United States)

    This in-situ vacuum extraction technology is a process for the removal and venting of volatile organic compounds (VOCs) from the vadose or unsaturated zone of soils. Often, these compounds can be removed from the vadose zone before they have a chance to contaminate groundwater. ...

  6. Terra Vac In Situ Vacuum Extraction System: Applications Analysis Report

    Science.gov (United States)

    This document is an evaluation of the Terra Vac in situ vacuum extraction system and its applicability as a treatment method for waste site cleanup. This report analyzes the results from the Superfund Innovative Technology Evaluation (SITE) Program’s 56-day demonstration at t...

  7. Supernumerary ring chromosome 20 characterized by fluorescence in situ hybridization

    NARCIS (Netherlands)

    Van Langen, Irene M.; Otter, Mariëlle A.; Aronson, Daniël C.; Overweg-Plandsoen, W.C.G.; Hennekam, Raoul C.M.; Leschot, Nico J.; Hoovers, Jan M.N.

    1996-01-01

    We report on a boy with mild dysmorphic features and developmental delay, in whom karyotyping showed an additional minute ring chromosome in 60% of metaphases. Fluorescence in situ hybridization (FISH) with a centromere specific probe demonstrated that the ring chromosome contained the centromeric r

  8. In situ quantification of membrane foulant accumulation by reflectometry

    NARCIS (Netherlands)

    Schroen, C. G. P. H.; Roosjen, A.; Norde, W.; Boom, R. M.; Tang, K.

    2010-01-01

    In this paper, we present laser light reflectometry [1] (not to be mistaken with ultrasound reflectometry [2] that uses ultrasound waves) as a tool for quantitative investigation of (the initial stages of) fouling on membrane-like surfaces. Reflectometry allows in situ investigation of adsorption an

  9. In situ polarization of polymer films in microsensors

    Science.gov (United States)

    Kranz, M.; Allen, M. G.; Hudson, T.

    2012-04-01

    Electret and polymer piezoelectric films have been previously integrated into Micro Electro Mechanical System (MEMS) acoustic sensors and energy harvesters. Common techniques employed in MEMS polymer integration include corona discharge [1] and backlighted thyratron [2], followed by macro-scale assembly of the polymer into the micro device. In contrast, this paper reports a method for post-fabrication in-situ polarization of polymer films embedded within the MEMS device itself. The method utilizes microplasma discharges with self-aligned charging grids integrated within the device to charge fluoropolymer films in a fashion similar to the common corona discharge technique. This in-situ approach enables the integration of uncharged polymer films into MEMS and subsequent post-fabrication and post-packaging polarization, simultaneously enabling the formation of buried or encapsulated electrets as well as eliminating the need to restrict fabrication and packaging processes that might otherwise discharge pre-charged materials. Using the in situ approach, a microscale charging grid structure is fabricated and suspended a short distance above the polymer film. After fabrication of the charging grid, standard microfabrication steps are performed to build MEMS sensors. After completing the entire fabrication and packaging flow, the polarization process is performed. When energized by a high voltage, the sharp metal edges of the charging grid lead to high dielectric fields that ionize the air in the gap and force electric charge onto the polymer surface. This paper presents modeling and results for this in situ polarization process.

  10. Genetic predisposition to ductal carcinoma in situ of the breast

    NARCIS (Netherlands)

    C. Petridis (Christos); R.H. Brook; V. Shah (Vandna); K. Kohut (Kelly); P. Gorman (Patricia); M. Caneppele (Michele); D. Levi (Dina); E. Papouli (Efterpi); N. Orr (Nick); A. Cox (Angela); S.S. Cross (Simon); I. dos Santos Silva (Isabel); J. Peto (Julian); A.J. Swerdlow (Anthony ); M. Schoemaker (Minouk); M.K. Bolla (Manjeet); Q. Wang (Qing); J. Dennis (Joe); K. Michailidou (Kyriaki); J. Benítez (Javier); A. González-Neira (Anna); D.C. Tessier (Daniel C.); D. Vincent (Daniel); J. Li (Jingmei); J.D. Figueroa (Jonine); V. Kristensen (Vessela); A.-L. Borresen-Dale (Anne-Lise); P. Soucy (Penny); J. Simard (Jacques); R.L. Milne (Roger); G.G. Giles (Graham); S. Margolin (Sara); A. Lindblom (Annika); T. Brüning (Thomas); H. Brauch (Hiltrud); M.C. Southey (Melissa); J.L. Hopper (John); T. Dörk (Thilo); N.V. Bogdanova (Natalia); M. Kabisch (Maria); U. Hamann (Ute); R.K. Schmutzler (Rita); A. Meindl (Alfons); H. Brenner (Hermann); V. Arndt (Volker); R. Winqvist (Robert); K. Pykäs (Katri); P.A. Fasching (Peter); M.W. Beckmann (Matthias); J. Lubinski (Jan); A. Jakubowska (Anna); A.M. Mulligan (Anna Marie); I.L. Andrulis (Irene); R.A.E.M. Tollenaar (Rob); P. Devilee (Peter); L. Le Marchand (Loic); C.A. Haiman (Christopher); A. Mannermaa (Arto); V-M. Kosma (Veli-Matti); P. Radice (Paolo); P. Peterlongo (Paolo); F. Marme (Federick); B. Burwinkel (Barbara); C.H.M. van Deurzen (Carolien); A. Hollestelle (Antoinette); N. Miller (Nicola); M. Kerin (Michael); D. Lambrechts (Diether); O.A.M. Floris; J. Wesseling (Jelle); H. Flyger (Henrik); S.E. Bojesen (Stig); S. Yao (Song); C.B. Ambrosone (Christine); G. Chenevix-Trench (Georgia); T. Truong (Thérèse); P. Guénel (Pascal); A. Rudolph (Anja); J. Chang-Claude (Jenny); H. Nevanlinna (Heli); C. Blomqvist (Carl); K. Czene (Kamila); J.S. Brand (Judith S.); J.E. Olson (Janet); F.J. Couch (Fergus); A.M. Dunning (Alison); P. Hall (Per); D.F. Easton (Douglas); P.D.P. Pharoah (Paul); S. Pinder (Sarah); M.K. Schmidt (Marjanka); I.P. Tomlinson (Ian); R. Roylance (Rebecca); M. García-Closas (Montserrat); E.J. Sawyer (Elinor)

    2016-01-01

    textabstractBackground: Ductal carcinoma in situ (DCIS) is a non-invasive form of breast cancer. It is often associated with invasive ductal carcinoma (IDC), and is considered to be a non-obligate precursor of IDC. It is not clear to what extent these two forms of cancer share low-risk susceptibilit

  11. In situ spectrophotometric measurement of dissolved inorganic carbon in seawater.

    Science.gov (United States)

    Liu, Xuewu; Byrne, Robert H; Adornato, Lori; Yates, Kimberly K; Kaltenbacher, Eric; Ding, Xiaoling; Yang, Bo

    2013-10-01

    Autonomous in situ sensors are needed to document the effects of today's rapid ocean uptake of atmospheric carbon dioxide (e.g., ocean acidification). General environmental conditions (e.g., biofouling, turbidity) and carbon-specific conditions (e.g., wide diel variations) present significant challenges to acquiring long-term measurements of dissolved inorganic carbon (DIC) with satisfactory accuracy and resolution. SEAS-DIC is a new in situ instrument designed to provide calibrated, high-frequency, long-term measurements of DIC in marine and fresh waters. Sample water is first acidified to convert all DIC to carbon dioxide (CO2). The sample and a known reagent solution are then equilibrated across a gas-permeable membrane. Spectrophotometric measurement of reagent pH can thereby determine the sample DIC over a wide dynamic range, with inherent calibration provided by the pH indicator's molecular characteristics. Field trials indicate that SEAS-DIC performs well in biofouling and turbid waters, with a DIC accuracy and precision of ∼2 μmol kg(-1) and a measurement rate of approximately once per minute. The acidic reagent protects the sensor cell from biofouling, and the gas-permeable membrane excludes particulates from the optical path. This instrument, the first spectrophotometric system capable of automated in situ DIC measurements, positions DIC to become a key parameter for in situ CO2-system characterizations.

  12. In-situ measurements in Vesivehmaa air field - STUK team

    Energy Technology Data Exchange (ETDEWEB)

    Markkanen, M.; Honkamaa, T.; Niskala, P. [Finnish Centre for Radiation and Nuclear Safety, Helsinki (Finland)

    1997-12-31

    Nineteen in-situ gamma-ray spectrometric measurements were performed in Vesivehmaa air field on 17th August 1995. The results for {sup 137}Cs and natural radionuclides are in good agreement with the results from soil sampling and laboratory analyses. (au).

  13. In situ nanoindentation in a transmission electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Minor, Andrew M. [Univ. of California, Berkeley, CA (United States)

    2002-01-01

    This dissertation presents the development of the novel mechanical testing technique of in situ nanoindentation in a transmission electron microscope (TEM). This technique makes it possible to simultaneously observe and quantify the mechanical behavior of nano-scale volumes of solids.

  14. In situ construction of a coordination zirconocene tetrahedron.

    Science.gov (United States)

    Liu, Guoliang; Ju, Zhanfeng; Yuan, Daqiang; Hong, Maochun

    2013-12-16

    The current study describes the first in situ synthesis and characterization of a new family of cationic coordination tetrahedra of both the V4F4 and V4E6 type, which are constructed by a new building block based on a trinuclear zirconocene moiety and the dicarboxylate or tricarboxylate anions.

  15. Current approaches for detection of carcinoma in situ testis

    DEFF Research Database (Denmark)

    Hoei-Hansen, Christina E; Olesen, Inge A; Jørgensen, Niels

    2007-01-01

    of carcinoma in situ (CIS). This review describes current possible approaches for the detection of CIS. At present, an open testicular biopsy is the only definitive way of establishing the presence of CIS. The tissue section should be of an adequate size, be properly fixed, and evaluation be supported...

  16. A rat model with an isolated bladder in situ

    DEFF Research Database (Denmark)

    Thulesen, J; Olsen, P S; Grevstad, J U

    1997-01-01

    This paper describes our method for producing a rat model with an isolated bladder in situ in which the bladder makes no contact with urine. First, the right kidney was removed, then an external catheter was placed in the right ureter for bladder infusions, and next the left ureter was anatomosed...

  17. Heat exchanger life extension via in-situ reconditioning

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, David E.; Muralidharan, Govindarajan

    2016-06-28

    A method of in-situ reconditioning a heat exchanger includes the steps of: providing an in-service heat exchanger comprising a precipitate-strengthened alloy wherein at least one mechanical property of the heat exchanger is degraded by coarsening of the precipitate, the in-service heat exchanger containing a molten salt working heat exchange fluid; deactivating the heat exchanger from service in-situ; in a solution-annealing step, in-situ heating the heat exchanger and molten salt working heat exchange fluid contained therein to a temperature and for a time period sufficient to dissolve the coarsened precipitate; in a quenching step, flowing the molten salt working heat-exchange fluid through the heat exchanger in-situ to cool the alloy and retain a supersaturated solid solution while preventing formation of large precipitates; and in an aging step, further varying the temperature of the flowing molten salt working heat-exchange fluid to re-precipitate the dissolved precipitate.

  18. In Situ Evaluation of Water-Rock Reactions during Carbon Dioxide Injection in Basaltic and Metasedimentary Rocks

    Science.gov (United States)

    Matter, J. M.; Assayag, N.; Goldberg, D.; Takahashi, T.

    2006-12-01

    Large differences between laboratory and field derived mineral reaction rates underscore the importance of evaluating mineral-fluid reactions under in situ conditions in a natural environment. This study investigates the extent of in situ water-rock reactions in basaltic and metasedimentary rocks (rich in Ca, Mg silicates) after the injection of CO2 enriched water, with the objective of providing information pertinent to permanent storage of anthropogenic CO2 in geologic reservoirs. CO2 injections were conducted using a single-well push-pull testing strategy. CO2 saturated water (pH 3.5) was injected into a hydraulically isolated and permeable aquifer in a 300-m experimental borehole. Water samples were retrieved after the CO2 injection. Mass transfer terms for Ca, Mg, Na, and Si were determined by using the measured ion concentrations. Using the mass balance, the weeks-long incubation time of the injected solution, and geometric estimates of the reactive surface area of the host rocks, in situ bulk rock dissolution rates of aquifer material were estimated. In addition, δ13C data coupled with total CO2 concentration were used as a tracer to quantitatively evaluate processes such as carbonate dissolution and precipitation, oxidation of organic matter and biological activity within the aquifer. Results show that the injected CO2 was neutralized within several days by two processes; mixing with aquifer water, and rock-water reactions. Calculated bulk rock dissolution rates decrease with increasing pH. The pH dependence of the dissolution rate for Ca is twice as large as for Mg, strongly favoring Ca release and possibly suggesting an additional source of Ca besides silicate minerals. Analyses of δ13C on water and rock samples confirm dissolution of calcium carbonates within the aquifer.

  19. Extraction of in situ cosmogenic 14C from olivine

    Science.gov (United States)

    Pigati, J.S.; Lifton, N.A.; Timothy, Jull A.J.; Quade, Jay

    2010-01-01

    Chemical pretreatment and extraction techniques have been developed previously to extract in situ cosmogenic radiocarbon (in situ 14C) from quartz and carbonate. These minerals can be found in most environments on Earth, but are usually absent from mafic terrains. To fill this gap, we conducted numerous experiments aimed at extracting in situ 14C from olivine ((Fe,Mg)2SiO4). We were able to extract a stable and reproducible in situ 14C component from olivine using stepped heating and a lithium metaborate (LiBO2) flux, following treatment with dilute HNO3 over a variety of experimental conditions. However, measured concentrations for samples from the Tabernacle Hill basalt flow (17.3 ?? 0.3 ka4) in central Utah and the McCarty's basalt flow (3.0 ?? 0.2 ka) in western New Mexico were significantly lower than expected based on exposure of olivine in our samples to cosmic rays at each site. The source of the discrepancy is not clear. We speculate that in situ 14C atoms may not have been released from Mg-rich crystal lattices (the olivine composition at both sites was ~Fo65Fa35). Alternatively, a portion of the 14C atoms released from the olivine grains may have become trapped in synthetic spinel-like minerals that were created in the olivine-flux mixture during the extraction process, or were simply retained in the mixture itself. Regardless, the magnitude of the discrepancy appears to be inversely proportional to the Fe/(Fe+Mg) ratio of the olivine separates. If we apply a simple correction factor based on the chemical composition of the separates, then corrected in situ 14C concentrations are similar to theoretical values at both sites. At this time, we do not know if this agreement is fortuitous or real. Future research should include measurement of in situ 14C concentrations in olivine from known-age basalt flows with different chemical compositions (i.e. more Fe-rich) to determine if this correction is robust for all olivine-bearing rocks. ?? 2010 by the Arizona

  20. Linking structure to fragility in bulk metallic glass-forming liquids

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Shuai, E-mail: shuai.wei@asu.edu, E-mail: m.stolpe@mx.uni-saarland.de [Department of Materials Science and Engineering, Saarland University, Campus C63, 66123 Saarbrücken (Germany); Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287 (United States); Stolpe, Moritz, E-mail: shuai.wei@asu.edu, E-mail: m.stolpe@mx.uni-saarland.de; Gross, Oliver; Gallino, Isabella; Hembree, William; Busch, Ralf [Department of Materials Science and Engineering, Saarland University, Campus C63, 66123 Saarbrücken (Germany); Evenson, Zach [Department of Materials Science and Engineering, Saarland University, Campus C63, 66123 Saarbrücken (Germany); Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), 51170 Köln (Germany); Bednarcik, Jozef [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22603 Hamburg (Germany); Kruzic, Jamie J. [Material Science, School of Mechanical, Industrial, and Manufacturing Engineering, Oregon State University, Corvallis, Oregon 97331 (United States)

    2015-05-04

    Using in-situ synchrotron X-ray scattering, we show that the structural evolution of various bulk metallic glass-forming liquids can be quantitatively connected to their viscosity behavior in the supercooled liquid near T{sub g}. The structural signature of fragility is identified as the temperature dependence of local dilatation on distinct key atomic length scales. A more fragile behavior results from a more pronounced thermally induced dilatation of the structure on a length scale of about 3 to 4 atomic diameters, coupled with shallower temperature dependence of structural changes in the nearest neighbor environment. These findings shed light on the structural origin of viscous slowdown during undercooling of bulk metallic glass-forming liquids and demonstrate the promise of predicting the properties of bulk metallic glasses from the atomic scale structure.

  1. In-Situ TEM Electrochemistry of Individual Nanowire and Nanoparticle Electrodes in a Li-Ion Cell

    Science.gov (United States)

    Huang, Jianyu

    2012-02-01

    Recently, we created the first Li-ion electrochemical cell inside a transmission electron microscope (TEM) and observed, in real time with atomic scale resolution, the lithiation/delithiation processes. This experiment opened the door for a suite of experimental studies involving in-situ TEM characterization of Li-ion battery materials. In this presentation, I'll first review our latest progress of using the in-situ electrochemical cell setup inside the TEM to reveal the intrinsic electrochemistry of several high energy density anode materials such as SnO2, ZnO, Si, Ge, Al nanowires, Si nanoparticles, carbon nanotubes, and graphene. Several electrochemical mechanisms were observed and characterized in real-time, including lithiation induced stress, volume changes, phase transformations, pulverization, cracking, embrittlement, and mechanical failure in anode materials. These results indicate the strong material, size and crystallographic orientation dependent electrochemical behavior and degradation mechanisms that occur in Li-ion battery anodes. In the future, we will need further advancements in in-situ characterization for understanding important processes in Li-ion batteries. For example, liquid cells are required in order to examine the electrochemical reactions between battery materials and the standard battery electrolytes, which are ethylene carbonate-based. Furthermore, in-situ studies need to be correlated with electrochemical studies performed on bulk electrodes. I will present a comparison between our in-situ results and electrochemical studies on conventional battery electrodes and highlight how in-situ studies can have important impact on the design of Li-ion batteries. Finally I will discuss outstanding challenging issues and opportunities in the field of Li-ion battery research. [4pt] References: Science 330, 1515 (2010); 330, 1485 (2010); Nano Lett. Doi: 10.1021/nl200412p, 10.1021/nl2024118, 10.1021/nl201684d, 10.1021/nl202088h, ACS Nano, doi: 10

  2. Additive manufacturing for in situ repair of osteochondral defects

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, Daniel L; Lipton, Jeffrey I; Bonassar, Lawrence J; Lipson, Hod, E-mail: dlc44@cornell.ed, E-mail: jil26@cornell.ed, E-mail: lb244@cornell.ed, E-mail: hod.lipson@cornell.ed [Cornell University, Mechanical and Aerospace Engineering, Ithaca, NY (United States)

    2010-09-15

    Tissue engineering holds great promise for injury repair and replacement of defective body parts. While a number of techniques exist for creating living biological constructs in vitro, none have been demonstrated for in situ repair. Using novel geometric feedback-based approaches and through development of appropriate printing-material combinations, we demonstrate the in situ repair of both chondral and osteochondral defects that mimic naturally occurring pathologies. A calf femur was mounted in a custom jig and held within a robocasting-based additive manufacturing (AM) system. Two defects were induced: one a cartilage-only representation of a grade IV chondral lesion and the other a two-material bone and cartilage fracture of the femoral condyle. Alginate hydrogel was used for the repair of cartilage; a novel formulation of demineralized bone matrix was used for bone repair. Repair prints for both defects had mean surface errors less than 0.1 mm. For the chondral defect, 42.8 {+-} 2.6% of the surface points had errors that were within a clinically acceptable error range; however, with 1 mm path planning shift, an estimated {approx}75% of surface points could likely fall within the benchmark envelope. For the osteochondral defect, 83.6 {+-} 2.7% of surface points had errors that were within clinically acceptable limits. In addition to implications for minimally invasive AM-based clinical treatments, these proof-of-concept prints are some of the only in situ demonstrations to-date, wherein the substrate geometry was unknown a priori. The work presented herein demonstrates in situ AM, suggests potential biomedical applications and also explores in situ-specific issues, including geometric feedback, material selection and novel path planning techniques.

  3. In-situ immobilization of arsenic in the underground; In-situ Immobilisierung von Arsen im Untergrund

    Energy Technology Data Exchange (ETDEWEB)

    Boochs, Peter W.; Billib, Max [Leibniz Universitaet Hannover (Germany). Inst. fuer Wasserwirtschaft, Hydrologie und landwirtschaftlichen Wasserbau; Krueger, Timo [Leibniz Universitaet Hannover (Germany). Inst. fuer Wasserwirtschaft, Hydrologie und landwirtschaftlichen Wasserbau; Heidt und Peters GmbH, Celle (Germany)

    2012-07-01

    Arsenic can be immobilized in the underground by means of iron chloride and oxygen. A test plant was established on the site of an arsenic-contaminated armament disposal in order to immobilize arsenic in-situ. The concentration of arsenic in the feed water was reduced explicitly.

  4. Geochemical and Microbiological Characteristics during in Situ Chemical Oxidation and in Situ Bioremediation at a Diesel Contaminated Site

    NARCIS (Netherlands)

    Sutton, N.B.; Kalisz, M.; Krupanek, J.; Marek, J.; Grotenhuis, J.T.C.; Smidt, H.; Weert, de J.; Rijnaarts, H.H.M.; Gaans, van P.; Keijzer, T.

    2014-01-01

    While in situ chemical oxidation with persulfate has seen wide commercial application, investigations into the impacts on groundwater characteristics, microbial communities and soil structure are limited. To better understand the interactions of persulfate with the subsurface and to determine the co

  5. Advanced sample environments for in situ neutron diffraction studies of nuclear materials

    Science.gov (United States)

    Reiche, Helmut Matthias

    Generation IV nuclear reactor concepts, such as the supercritical-water-cooled nuclear reactor (SCWR), are actively researched internationally. Operating conditions above the critical point of water (374°C, 22.1 MPa) and fuel core temperature that potentially exceed 1850°C put a high demand on the surrounding materials. For their safe application, it is essential to characterize and understand the material properties on an atomic scale such as crystal structure and grain orientation (texture) changes as a function of temperature and stress. This permits the refinement of models predicting the macroscopic behavior of the material. Neutron diffraction is a powerful tool in characterizing such crystallographic properties due to their deep penetration depth into condensed matter. This leads to the ability to study bulk material properties, as opposed to surface effects, and allows for complex sample environments to study e.g. the individual contributions of thermo-mechanical processing steps during manufacturing, operating or accident scenarios. I present three sample environments for in situ neutron diffraction studies that provide such crystallographic information and have been successfully commissioned and integrated into the user program of the High Pressure -- Preferred Orientation (HIPPO) diffractometer at the Los Alamos Neutron Science Center (LANSCE) user facility. I adapted a sample changer for reliable and fast automated texture measurements of multiple specimens. I built a creep furnace combining a 2700 N load frame with a resistive vanadium furnace, capable of temperatures up to 1000°C, and manipulated by a pair of synchronized rotation stages. This combination allows following deformation and temperature dependent texture and strain evolutions in situ. Utilizing the presented sample changer and creep furnace we studied pressure tubes made of Zr-2.5wt%Nb currently employed in CANDURTM nuclear reactors and proposed for future SCWRs, acting as the primary

  6. In Situ-produced vs. Meteoric 10Be in Hillslope Soils: One Isotope, Two Tracers, Different Stories

    Science.gov (United States)

    Jungers, M. C.; Bierman, P. R.; Matmon, A.; Cox, R.; Pavich, M.; Finkel, R. C.

    2009-12-01

    , then significant amounts of 10Be are not being accounted for in our inventory calculations. If meteoric 10Be is fully retained by a given landscape, soil residence times inferred from each type of 10Be should agree. However depth profiles and downslope transects from each field area show differing degrees of meteoric 10Be mobility. We compare meteoric 10Be concentrations from each of our field sites to trends in CBD-extractable Al and Fe oxides, bulk soil pH, and mean grain size. Meteoric 10Be mobility correlates positively to trends in mobile Fe and Al oxides and negatively to soil pH. These data suggest that a meaningful comparison between a landscape’s in situ-produced and meteoric 10Be inventories requires a thorough understanding of the geochemistry of the sampled soil mantle.

  7. In situ gamma-ray spectrometry: A tutorial for environmental radiation scientists

    Energy Technology Data Exchange (ETDEWEB)

    Miller, K.M.; Shebell, P.

    1993-10-01

    This tutorial is intended for those in the environmental field who perform assessments in areas where there is radioactive contamination in the surface soil. Techniques will be introduced for performing on-site quantitative measurements of gamma radiation in the environment using high resolution germanium detectors. A basic understanding of ionizing radiation principles is assumed; however, a detailed knowledge of gamma spectrometry systems is not required. Emphasized is the practical end of operations in the field and the conversion of measured full absorption peak count rates in a collected spectrum to meaningful radiological quantities, such as the concentration of a radionuclide in the soil, activity per unit area, and dose rate in the air. The theory of operation and calibration procedures will be covered in detail to provide the necessary knowledge to adapt the technique to site-specific problems. Example calculations for detector calibration are also provided.

  8. Morphological, electronic and magnetic characterization of bulk Cr tips

    Energy Technology Data Exchange (ETDEWEB)

    Corbetta, Marco; Ouazi, Safia; Nahas, Yasmine; Oka, Hirofumi; Wedekind, Sebastian; Sander, Dirk; Kirschner, Juergen [Max-Planck-Institut fuer Mikrostrukturphysik, Halle (Germany); Donati, Fabio [Max-Planck-Institut fuer Mikrostrukturphysik, Halle (Germany); CNISM, NEMAS, Milano (Italy); Dipartimento di Energia - Politecnico di Milano, Milano (Italy)

    2011-07-01

    The most delicate task for successful SP-STM measurements is the preparation of suitable tips offering high spatial resolution, high spin polarization and negligible magnetic stray field. Nonmagnetic tips covered with an ultrathin film of antiferromagnetic material as Cr have been largely and successfully used. The main drawback of coated tips is that an in-situ preparation is required. Recently a simple and reliable method for the preparation of bulk Cr tips using only a standard electrochemical etching has been proposed. We produced and used such tips for in-field spin-polarized STM measurements at 7 K on Co nano-islands on Cu(111). We obtain stable and reliable spin-resolved imaging and spectroscopy results. We measure symmetric hysteresis loops of the differential conductance, which show that the magnetization direction of the Cr tip apex follows the external magnetic field direction. Measuring dI/dV asymmetry curves on Co islands we find that the spin polarization of bulk Cr tips can be as large as 30%, which is larger as compared to Cr/Co/W tips.

  9. X-Ray Nanoscopy of a Bulk Heterojunction.

    Directory of Open Access Journals (Sweden)

    Nilesh Patil

    Full Text Available Optimizing the morphology of bulk heterojunctions is known to significantly improve the photovoltaic performance of organic solar cells, but available quantitative imaging techniques are few and have severe limitations. We demonstrate X-ray ptychographic coherent diffractive imaging applied to all-organic blends. Specifically, the phase-separated morphology in bulk heterojunction photoactive layers for organic solar cells, prepared from a 50:50 blend of poly(3-hexylthiophene (P3HT and phenyl-C61-butyric acid methyl ester (PCBM and thermally treated for different annealing times is imaged to high resolution. Moreover, using a fast-scanning calorimetry chip setup, the nano-morphological changes caused by repeated thermal annealing applied to the same sample could be monitored. X-ray ptychography resolves to better than 100 nm the phase-segregated domains of electron donor and electron acceptor materials over a large field of view within the active layers. The quantitative phase contrast images further allow us to estimate the local volume fraction of PCBM across the photovoltaically active layers. The volume fraction gradient for different regions provides insight on the PCBM diffusion across the depletion zone surrounding PCBM aggregates. Phase contrast X-ray microscopy is under rapid development, and the results presented here are promising for future studies of organic-organic blends, also under in situ conditions, e.g., for monitoring the structural stability during UV-Vis irradiation.

  10. X-Ray Nanoscopy of a Bulk Heterojunction

    Science.gov (United States)

    Patil, Nilesh; Torbjørn, Eirik; Skjønsfjell, Bakken; Van den Brande, Niko; Chavez Panduro, Elvia Anabela; Claessens, Raf; Guizar-Sicairos, Manuel; Van Mele, Bruno; Breiby, Dag Werner

    2016-07-01

    Optimizing the morphology of bulk heterojunctions is known to significantly improve the photovoltaic performance of organic solar cells, but available quantitative imaging techniques are few and have severe limitations. We demonstrate X-ray ptychographic coherent diffractive imaging applied to all-organic blends. Specifically, the phase-separated morphology in bulk heterojunction photoactive layers for organic solar cells, prepared from a 50:50 blend of poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) and thermally treated for different annealing times is imaged to high resolution. Moreover, using a fast-scanning calorimetry chip setup, the nano-morphological changes caused by repeated thermal annealing applied to the same sample could be monitored. X-ray ptychography resolves to better than 100 nm the phase-segregated domains of electron donor and electron acceptor materials over a large field of view within the active layers. The quantitative phase contrast images further allow us to estimate the local volume fraction of PCBM across the photovoltaically active layers. The volume fraction gradient for different regions provides insight on the PCBM diffusion across the depletion zone surrounding PCBM aggregates. Phase contrast X-ray microscopy is under rapid development, and the results presented here are promising for future studies of organic-organic blends, also under in situ conditions, e.g., for monitoring the structural stability during UV-Vis irradiation.

  11. An In Situ Method for Sizing Insoluble Residues in Precipitation and Other Aqueous Samples.

    Science.gov (United States)

    Axson, Jessica L; Creamean, Jessie M; Bondy, Amy L; Capracotta, Sonja S; Warner, Katy Y; Ault, Andrew P

    2015-01-01

    Particles are frequently incorporated into clouds or precipitation, influencing climate by acting as cloud condensation or ice nuclei, taking up coatings during cloud processing, and removing species through wet deposition. Many of these particles, particularly ice nuclei, can remain suspended within cloud droplets/crystals as insoluble residues. While previous studies have measured the soluble or bulk mass of species within clouds and precipitation, no studies to date have determined the number concentration and size distribution of insoluble residues in precipitation or cloud water using in situ methods. Herein, for the first time we demonstrate that Nanoparticle Tracking Analysis (NTA) is a powerful in situ method for determining the total number concentration, number size distribution, and surface area distribution of insoluble residues in precipitation, both of rain and melted snow. The method uses 500 μL or less of liquid sample and does not require sample modification. Number concentrations for the insoluble residues in aqueous precipitation samples ranged from 2.0-3.0(±0.3)×10(8) particles cm(-3), while surface area ranged from 1.8(±0.7)-3.2(±1.0)×10(7) μm(2) cm(-3). Number size distributions peaked between 133-150 nm, with both single and multi-modal character, while surface area distributions peaked between 173-270 nm. Comparison with electron microscopy of particles up to 10 μm show that, by number, > 97% residues are <1 μm in diameter, the upper limit of the NTA. The range of concentration and distribution properties indicates that insoluble residue properties vary with ambient aerosol concentrations, cloud microphysics, and meteorological dynamics. NTA has great potential for studying the role that insoluble residues play in critical atmospheric processes.

  12. Stable water isotope and surface heat flux simulation using ISOLSM: Evaluation against in-situ measurements

    KAUST Repository

    Cai, Mick Y.

    2015-04-01

    The stable isotopes of water are useful tracers of water sources and hydrological processes. Stable water isotope-enabled land surface modeling is a relatively new approach for characterizing the hydrological cycle, providing spatial and temporal variability for a number of hydrological processes. At the land surface, the integration of stable water isotopes with other meteorological measurements can assist in constraining surface heat flux estimates and discriminate between evaporation (E) and transpiration (T). However, research in this area has traditionally been limited by a lack of continuous in-situ isotopic observations. Here, the National Centre for Atmospheric Research stable isotope-enabled Land Surface Model (ISOLSM) is used to simulate the water and energy fluxes and stable water isotope variations. The model was run for a period of one month with meteorological data collected from a coastal sub-tropical site near Sydney, Australia. The modeled energy fluxes (latent heat and sensible heat) agreed reasonably well with eddy covariance observations, indicating that ISOLSM has the capacity to reproduce observed flux behavior. Comparison of modeled isotopic compositions of evapotranspiration (ET) against in-situ Fourier Transform Infrared spectroscopy (FTIR) measured bulk water vapor isotopic data (10. m above the ground), however, showed differences in magnitude and temporal patterns. The disparity is due to a small contribution from local ET fluxes to atmospheric boundary layer water vapor (~1% based on calculations using ideal gas law) relative to that advected from the ocean for this particular site. Using ISOLSM simulation, the ET was partitioned into E and T with 70% being T. We also identified that soil water from different soil layers affected T and E differently based on the simulated soil isotopic patterns, which reflects the internal working of ISOLSM. These results highlighted the capacity of using the isotope-enabled models to discriminate

  13. In situ amplification of DNA fragments specific for human Y chromosome in cellular nuclei by PCR

    Institute of Scientific and Technical Information of China (English)

    张锡元; 姜海波; 李立家; 马琦; 杨建琪; 刘汀

    1996-01-01

    Using single primer pairs Y3 and Y4, in siru polymerase chain reaction (in situ PCR) was successfully performed on the specimen slides of peripheral leukocytes. By both of the direct digpxiginin-11-dUTP incorporation into PCR products with in situ PCR (direct in situ PCR) and in situ PCR followed by detection of in situ hybridization (indirect in siru PCR), DNA fragments specific for human Y chromosome were obviously amplified in cellular nuclei of specimens on the slides. The results were verified by Southern analysis. The methodology of in situ PCR and its application were discussed.

  14. Pressure effect on crystallization kinetics in Zr46.8Ti8.2Cu7.5Ni10Be27.5 bulk glass

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Gerward, Leif; Xu, Y.S.

    2002-01-01

    Crystallization kinetics of a Zr46.8Ti8.2Cu7.5Ni10Be27.5 bulk glass in the supercooled liquid region have been investigated by performing in situ high-temperature and high-pressure x-ray diffraction measurements using synchrotron radiation. A pressure-time-temperature-transformation diagram, desc...

  15. In situ solid-state NMR spectroscopy of electrochemical cells: batteries, supercapacitors, and fuel cells.

    Science.gov (United States)

    Blanc, Frédéric; Leskes, Michal; Grey, Clare P

    2013-09-17

    prevent dendrite formation. The in situ method was also applied to monitor (by (11)B NMR) electrochemical double-layer formation in supercapacitors in real time. Though this method is useful, it comes with challenges. The separation of the contributions from the different cell components in the NMR spectra is not trivial because of overlapping resonances. In addition, orientation-dependent NMR interactions, including the spatial- and orientation-dependent bulk magnetic susceptibility (BMS) effects, can lead to resonance broadening. Efforts to understand and mitigate these BMS effects are discussed in this Account. The in situ NMR investigation of fuel cells initially focused on the surface electrochemistry at the electrodes and the electrochemical oxidation of methanol and CO to CO2 on the Pt cathode. On the basis of the (13)C and (195)Pt NMR spectra of the adsorbates and electrodes, CO adsorbed on Pt and other reaction intermediates and complete oxidation products were detected and their mode of binding to the electrodes investigated. Appropriate design and engineering of the NMR hardware has allowed researchers to integrate intact direct methanol fuel cells into NMR probes. Chemical transformations of the circulating methanol could be followed and reaction intermediates could be detected in real time by either (2)H or (13)C NMR spectroscopy. By use of the in situ NMR approach, factors that control fuel cell performance, such as methanol cross over and catalyst performance, were identified.

  16. Investigation of environmental samples by low-level gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Koehler, M. [Nuclear Engineering and Analytics Rossendorf, Inc., Dresden (Germany); Niese, S. [Nuclear Engineering and Analytics Rossendorf, Inc., Dresden (Germany)

    1997-03-01

    The average sample number in our laboratory is about 200 per month (12% technical solid state, 30% geological solid state, 6% geological solid state with low mass, 12% biological, 11% water directly, 25% water after chemical separation, 4% others). In 54% of the measurements the background continuum, and though the detection limit, is determined only by the detector himself and not by the compton continuum from high energy lines in the sample. Some examples in the presented work aim to prove the advantages of gamma ray spectrometry in the underground laboratory Felsenkeller. (orig./DG)

  17. Statistical modelling of neural networks in {gamma}-spectrometry applications

    Energy Technology Data Exchange (ETDEWEB)

    Vigneron, V.; Martinez, J.M. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. de Mecanique et de Technologie; Morel, J.; Lepy, M.C. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. des Applications et de la Metrologie des Rayonnements Ionisants

    1995-12-31

    Layered Neural Networks, which are a class of models based on neural computation, are applied to the measurement of uranium enrichment, i.e. the isotope ratio {sup 235} U/({sup 235} U + {sup 236} U + {sup 238} U). The usual method consider a limited number of {Gamma}-ray and X-ray peaks, and require previously calibrated instrumentation for each sample. But, in practice, the source-detector ensemble geometry conditions are critically different, thus a means of improving the above convention methods is to reduce the region of interest: this is possible by focusing on the K{sub {alpha}} X region where the three elementary components are present. Real data are used to study the performance of neural networks. Training is done with a Maximum Likelihood method to measure uranium {sup 235} U and {sup 238} U quantities in infinitely thick samples. (authors). 18 refs., 6 figs., 3 tabs.

  18. Fourier transformation methods in the field of gamma spectrometry

    Indian Academy of Sciences (India)

    A Abdel-Hafiez

    2006-09-01

    The basic principles of a new version of Fourier transformation is presented. This new version was applied to solve some main problems such as smoothing, and denoising in gamma spectroscopy. The mathematical procedures were first tested by simulated data and then by actual experimental data.

  19. Determination of IRT-2M fuel burnup by gamma spectrometry.

    Science.gov (United States)

    Koleška, Michal; Viererbl, Ladislav; Marek, Milan; Ernest, Jaroslav; Šunka, Michal; Vinš, Miroslav

    2016-01-01

    A spectrometric system was developed for evaluating spent fuel in the LVR-15 research reactor, which employs highly enriched (36%) IRT-2M-type fuel. Such system allows the measurement of detailed fission product profiles. Within these measurements, nuclides such as (137)Cs, (134)Cs, (144)Ce, (106)Ru and (154)Eu may be detected in fuel assemblies with different cooling times varying between 1.67 and 7.53 years. Burnup calculations using the MCNPX Monte Carlo code data showed good agreement with measurements, though some discrepancies were observed in certain regions. These discrepancies are attributed to the evaluation of irradiation history, reactor regulation pattern and buildup schemes.

  20. Mobile gamma spectrometry. Evaluation of the Resume 99 exercise

    Energy Technology Data Exchange (ETDEWEB)

    Mellander, H.; Karlsson, S. [Swedish Radiation Protection Authority, Stockholm (Sweden); Aage, H.K.; Korsbech, U. [Technical Univ. of Denmark, Lyngby (Denmark); Lauritzen, B. [Risoe National Laboratory, Roskilde (Denmark); Smethurst, M. [Geological Survey of Norway, Trondheim (Norway)

    2002-06-01

    During the RESUME 99 exercise, the radiocaesium ({sup 137}Cs) activity in the surroundings of Gavle in central Sweden was ma{sup p}ped using car-borne gamma-ray spectrometry (CGS). The CGS data along with airborne gamma-ray spectrometry (AGS) data from the same area have been used to examine possible correlations between the CGS and AGS results, detector type and position, and geographical information, such as land-use and road type. The overall differences between various CGS results are small, while larger differences are found between AGS and CGS results. In general only little correlation was found with land-use and with road-type and width. The differences between AGS and CGS results arise because airborne detectors have a different field of view than a ground-based detector. From an analysis of the depth-dependency of AGS and CGS data for a depth-distributed source, it is found that the mean mass depth may be inferred from the ratio of AGS to CGS spectral count rates. Integration of AGS and CGS data requires a precise definition of quantities and units for reporting activity concentrations in a complicated geometry and care must be taken to translate AGS results into equivalent CGS quantities taking into account the spatial distribution of the radionuclides. (au)

  1. Spatially Resolved, In Situ Carbon Isotope Analysis of Archean Organic Matter

    Science.gov (United States)

    Williford, Kenneth H.; Ushikubo, Takayuki; Lepot, Kevin; Hallmann, Christian; Spicuzza, Michael J.; Eigenbrode, Jennifer L.; Summons, Roger E.; Valley, John W.

    2011-01-01

    Spatiotemporal variability in the carbon isotope composition of sedimentary organic matter (OM) preserves information about the evolution of the biosphere and of the exogenic carbon cycle as a whole. Primary compositions, and imprints of the post-depositional processes that obscure them, exist at the scale of individual sedimentary grains (mm to micron). Secondary ion mass spectrometry (SIMS) (1) enables analysis at these scales and in petrographic context, (2) permits morphological and compositional characterization of the analyte and associated minerals prior to isotopic analysis, and (3) reveals patterns of variability homogenized by bulk techniques. Here we present new methods for in situ organic carbon isotope analysis with sub-permil precision and spatial resolution to 1 micron using SIMS, as well as new data acquired from a suite of Archean rocks. Three analytical protocols were developed for the CAMECA ims1280 at WiscSIMS to analyze domains of varying size and carbon concentration. Average reproducibility (at 2SD) using a 6 micron spot size with two Faraday cup detectors was 0.4 %, and 0.8 % for analyses using 1 micron and 3 micron spot sizes with a Faraday cup (for C-12) and an electron multiplier (for C-13). Eight coals, two ambers, a shungite, and a graphite were evaluated for micron-scale isotopic heterogeneity, and LCNN anthracite (delta C-13 = -23.56 +/- 0.1 %, 2SD) was chosen as the working standard. Correlation between instrumental bias and H/C was observed and calibrated for each analytical session using organic materials with H/C between 0.1 and 1.5 (atomic), allowing a correction based upon a C-13H/C-13 measurement included in every analysis. Matrix effects of variable C/SiO2 were evaluated by measuring mm to sub-micron graphite domains in quartzite from Bogala mine, Sri Lanka. Apparent instrumental bias and C-12 count rate are correlated in this case, but this may be related to a crystal orientation effect in graphite. Analyses of amorphous

  2. In situ carbon isotope analysis of Archean organic matter with SIMS

    Science.gov (United States)

    Williford, K. H.; Ushikubo, T.; Lepot, K.; Hallmann, C.; Spicuzza, M. J.; Eigenbrode, J. L.; Summons, R. E.; Valley, J. W.

    2011-12-01

    Spatiotemporal variability in the carbon isotope composition of sedimentary organic matter (OM) preserves information about the evolution of the biosphere and of the exogenic carbon cycle as a whole. Primary compositions, and imprints of the post-depositional processes that obscure them, exist at the scale of individual sedimentary grains (mm to μm). Secondary ion mass spectrometry (SIMS) (1) enables analysis at these scales and in petrographic context, (2) permits morphological and compositional characterization of the analyte and associated minerals prior to isotopic analysis, and (3) reveals patterns of variability homogenized by bulk techniques. Here we present new methods for in situ organic carbon isotope analysis with sub-permil precision and spatial resolution to 1 μm using SIMS, as well as new data acquired from a suite of Archean rocks. Three analytical protocols were developed for the CAMECA ims1280 at WiscSIMS to analyze domains of varying size and carbon concentration. Average reproducibility (at 2SD) using a 6 μm spot size with two Faraday cup detectors was 0.4%, and 0.8% for analyses using 1 μm and 3 μm spot sizes with a Faraday cup (for 12C) and an electron multiplier (for 13C). Eight coals, two ambers, a shungite, and a graphite were evaluated for μm-scale isotopic heterogeneity, and LCNN anthracite (δ13C = -23.56 ± 0.1%, 2SD) was chosen as the working standard. Correlation between instrumental bias and H/C was observed and calibrated for each analytical session using organic materials with H/C between 0.1 and 1.5 (atomic), allowing a correction based upon a 13CH/13C measurement included in every analysis and a 12CH measurement made immediately after every analysis. The total range of the H/C effect observed for the Archean samples analyzed was < 3%. Analyses of Archean OM domains for which 12C count rate varies with the proportions of organic carbon, carbonate carbon, and quartz suggest that instrumental bias is consistent for 12C count

  3. Visualization of enzyme activities inside earthworm biopores by in situ soil zymography

    Science.gov (United States)

    Thu Duyen Hoang, Thi; Razavi, Bahar. S.; Blagodatskaya, Evgenia; Kuzyakov, Yakov

    2015-04-01

    Earthworms can strongly activate microorganisms, increase microbial and enzyme activities and consequently the turnover of native soil organic matter. In extremely dynamic microhabitats and hotspots as biopores made by earthworms, the in situ enzyme activities are a footprint of complex biotic interactions. The effect of earthworms on the alteration of enzyme activities inside biopores and the difference between bio-pores and earthworm-free soil was visualized by in situ soil zymography (Spohn and Kuzyakov, 2014). For the first time, we prepared quantitative imaging of enzyme activities in biopores. Furthermore, we developed the zymography technique by direct application of a substrate saturated membrane to the soil to obtain better spatial resolution. Lumbricus terrestris L. was placed into transparent box (15×20×15cm). Simultaneously, maize seed was sown in the soil. Control soil box with maize and without earthworm was prepared in the same way. After two weeks when bio-pore systems were formed by earthworm, we visualized in situ enzyme activities of five hydrolytic enzymes (β-glucosidase, cellobiohydrolase, chitinase, xylanase, leucine aminopeptidase) and phosphatase. Followed by non-destructive zymography, biopore samples and control soil were destructively collected to assay enzyme kinetics by fluorogenically labeled substrates method. Zymography showed higher activity of β-glucosidase, chitinase, xylanase and phosphatase in biopores comparing to bulk soil. These differences were further confirmed by fluorimetric microplate enzyme assay detected significant difference of Vmax in four above mentioned enzymes. Vmax of β-glucosidase, chitinase, xylanase and phosphatase in biopores is 68%, 108%, 50% and 49% higher than that of control soil. However, no difference in cellobiohydrolase and leucine aminopeptidase kinetics between biopores and control soil were detected. This indicated little effect of earthworms on protein and cellulose transformation in soil

  4. Bulk Moisture and Salinity Sensor

    Science.gov (United States)

    Nurge, Mark; Monje, Oscar; Prenger, Jessica; Catechis, John

    2013-01-01

    Measurement and feedback control of nutrient solutions in plant root zones is critical to the development of healthy plants in both terrestrial and reduced-gravity environments. In addition to the water content, the amount of fertilizer in the nutrient solution is important to plant health. This typically requires a separate set of sensors to accomplish. A combination bulk moisture and salinity sensor has been designed, built, and tested with different nutrient solutions in several substrates. The substrates include glass beads, a clay-like substrate, and a nutrient-enriched substrate with the presence of plant roots. By measuring two key parameters, the sensor is able to monitor both the volumetric water content and salinity of the nutrient solution in bulk media. Many commercially available moisture sensors are point sensors, making localized measurements over a small volume at the point of insertion. Consequently, they are more prone to suffer from interferences with air bubbles, contact area of media, and root growth. This makes it difficult to get an accurate representation of true moisture content and distribution in the bulk media. Additionally, a network of point sensors is required, increasing the cabling, data acquisition, and calibration requirements. measure the dielectric properties of a material in the annular space of the vessel. Because the pore water in the media often has high salinity, a method to measure the media moisture content and salinity simultaneously was devised. Characterization of the frequency response for capacitance and conductance across the electrodes was completed for 2-mm glass bead media, 1- to 2-mm Turface (a clay like media), and 1- to 2-mm fertilized Turface with the presence of root mass. These measurements were then used to find empirical relationships among capacitance (C), the dissipation factor (D), the volumetric water content, and the pore water salinity.

  5. In Situ Formation and Dynamical Evolution of Hot Jupiter Systems

    Science.gov (United States)

    Batygin, Konstantin; Bodenheimer, Peter H.; Laughlin, Gregory P.

    2016-10-01

    Hot Jupiters, giant extrasolar planets with orbital periods shorter than ˜10 days, have long been thought to form at large radial distances, only to subsequently experience long-range inward migration. Here, we offer the contrasting view that a substantial fraction of the hot Jupiter population formed in situ via the core-accretion process. We show that under conditions appropriate to the inner regions of protoplanetary disks, rapid gas accretion can be initiated by super-Earth-type planets, comprising 10-20 Earth masses of refractory material. An in situ formation scenario leads to testable consequences, including the expectation that hot Jupiters should frequently be accompanied by additional low-mass planets with periods shorter than ˜100 days. Our calculations further demonstrate that dynamical interactions during the early stages of planetary systems’ lifetimes should increase the inclinations of such companions, rendering transits rare. High-precision radial velocity monitoring provides the best prospect for their detection.

  6. Monitoring Cocrystal Formation via In Situ Solid-State NMR.

    Science.gov (United States)

    Mandala, Venkata S; Loewus, Sarel J; Mehta, Manish A

    2014-10-01

    A detailed understanding of the mechanism of organic cocrystal formation remains elusive. Techniques that interrogate a reacting system in situ are preferred, though experimentally challenging. We report here the results of a solid-state in situ NMR study of the spontaneous formation of a cocrystal between a pharmaceutical mimic (caffeine) and a coformer (malonic acid). Using (13)C magic angle spinning NMR, we show that the formation of the cocrystal may be tracked in real time. We find no direct evidence for a short-lived, chemical shift-resolved amorphous solid intermediate. However, changes in the line width and line center of the malonic acid methylene resonance, in the course of the reaction, provide subtle clues to the mode of mass transfer that underlies cocrystal formation.

  7. In situ electrochemical dilatometry of carbide-derived carbons

    Energy Technology Data Exchange (ETDEWEB)

    Hantel, M M [Paul Scherrer Institut, Villigen, Switzerland; Presser, Volker [ORNL; Gogotsi, Yury [ORNL

    2011-01-01

    The long life durability and extraordinary stability of supercapacitors are ascribed to the common concept that the charge storage is purely based on double-layer charging. Therefore the ideal supercapacitor electrode should be free of charge induced microscopic structural changes. However, recent in-situ investigations on different carbon materials for supercapacitor electrodes have shown that the charge and discharge is accompanied by dimensional changes of the electrode up to several percent. This work studies the influence of the pore size on the expansion behavior of carbon electrodes derived from titanium carbide-derived carbons with an average pore size between 5 and 8 Using tetraethylammonium tetrafluoroborate in acetonitrile, the swelling of the electrodes was measured by in situ dilatometry. The experiments revealed an increased expansion on the negatively charged electrode for pores below 6 , which could be described with pore swelling.

  8. A Nanoaquarium for in situ Electron Microscopy in Liquid Media

    CERN Document Server

    Grogan, Joseph M

    2010-01-01

    The understanding of many nanoscale processes occurring in liquids such as colloidal crystal formation, aggregation, nanowire growth, electrochemical deposition, and biological interactions would benefit greatly from real-time, in situ imaging with the nanoscale resolution of transmission electron microscopes (TEMs) and scanning transmission electron microscopes (STEMs). However, these imaging tools cannot readily be used to observe processes occurring in liquid media without addressing two experimental hurdles: sample thickness and sample evaporation in the high vacuum microscope chamber. To address these challenges, we have developed a nano-Hele-Shaw cell, dubbed the nanoaquarium. The device consists of a hermetically-sealed, 100 nm tall, liquid-filled chamber sandwiched between two freestanding, 50 nm thick, silicon nitride membranes. Embedded electrodes are integrated into the device. This fluid dynamics video features particle motion and aggregation during in situ STEM of nanoparticles suspended in liqui...

  9. CALIBRATION OF DENSITOMETRY IN RADIO-ISOTOPIC IN SITU HYBRIDIZATION

    Directory of Open Access Journals (Sweden)

    Jan M Ruijter

    2011-05-01

    Full Text Available Densitometry on autoradiographs of sections processed for in situ hybridization provides a direct measure for the in situ quantification of mRNA. Gelatin spots, containing different concentrations of the radioisotope, and processed in parallel with the tissue sections, can be used as a sensitive model to calibrate the densitometric measurements. The shape of the gelatin spots was shown to be circular with a parabolic crosssectional profile. This simple shape allows the subdivision of the spot into a series of concentric rings, which enables an unbiased measurement of the optical density - radioactivity relation. This spot measurement is also applicable to DNA arrays spotted on glass or membranes. A new model, explaining the optical density of autoradiographs, was derived and fitted to the calibration points. The use of this calibration method is crucial for the correct interpretation of autoradiographs

  10. Fabrication and aging behaviour of in-situ aluminum composites

    Energy Technology Data Exchange (ETDEWEB)

    Erarslan, Yaman [Yildiz Technical Univ., Instanbul (Turkey). Metallurgical and Materials Engineering Dept.

    2011-07-01

    Commonly applied in situ procedures with the aim of producing alumina particles or whiskers include the reactions between a metal oxide and aluminum. The metal, reduced with the alumina formation reaction, afterwards generally reacts with Al and transforms into an intermetallic form which will act as a reinforcing member in the composition of the matrix. In this study, by adding CuO powder in ratios of 5, 10 and 15 wt.-% composite billets were produced by the in situ procedure of stir casting. XRD patterns and microstructures of the produced Al-Al{sub 2}O{sub 3} composites were examined by using optical and electron microscopy (SEM). Following the homogenization procedure on the composite material, hot deformation and thermal aging procedures were applied. The changes in the mechanical properties were compared with commercially pure Aluminum. (orig.)

  11. In Situ Formation and Dynamical Evolution of Hot Jupiter Systems

    CERN Document Server

    Batygin, Konstantin; Laughlin, Gregory P

    2015-01-01

    Hot Jupiters, giant extrasolar planets with orbital periods shorter than ~10 days, have long been thought to form at large radial distances, only to subsequently experience long-range inward migration. Here, we propose that in contrast with this picture, a substantial fraction of the hot Jupiter population formed in situ via the core accretion process. We show that under conditions appropriate to the inner regions of protoplanetary disks, rapid gas accretion can be initiated by Super-Earth type planets, comprising 10-20 Earth masses of refractory composition material. An in situ formation scenario leads to testable consequences, including the expectation that hot Jupiters should frequently be accompanied by additional low-mass planets with periods shorter than ~100 days. Our calculations further demonstrate that dynamical interactions during the early stages of planetary systems' lifetimes should increase the inclinations of such companions, rendering transits rare. High-precision radial velocity monitoring p...

  12. Challenges in subsurface in situ remediation of chlorinated solvents

    DEFF Research Database (Denmark)

    Broholm, Mette Martina; Fjordbøge, Annika Sidelmann; Christiansen, Camilla Maymann

    2014-01-01

    Chlorinated solvent source zones in the subsurface pose a continuous threat to groundwater quality at many sites worldwide. In situ remediation of these sites is particularly challenging in heterogeneous fractured media and where the solvents are present as DNAPL. In situ remediation by chemical...... as well as biological degradation of chlorinated solvents is a contact sport and requires direct contact between the contaminant and the reactants and/or degrading microorganisms. In fractured geologic media, where contaminants have spread to the low permeability matrix by diffusion, the contact between......-clay mixing for contact; hydrophobic and/or mobile nano-reactants targeting DNAPL. The complexity of the technologies varies greatly and the current level of implementation ranges from multiple full scale applications to bench scale testing. However, the basic degradation reaction involved is usually well...

  13. Underwater microscopy for in situ studies of benthic ecosystems

    Science.gov (United States)

    Mullen, Andrew D.; Treibitz, Tali; Roberts, Paul L. D.; Kelly, Emily L. A.; Horwitz, Rael; Smith, Jennifer E.; Jaffe, Jules S.

    2016-07-01

    Microscopic-scale processes significantly influence benthic marine ecosystems such as coral reefs and kelp forests. Due to the ocean's complex and dynamic nature, it is most informative to study these processes in the natural environment yet it is inherently difficult. Here we present a system capable of non-invasively imaging seafloor environments and organisms in situ at nearly micrometre resolution. We overcome the challenges of underwater microscopy through the use of a long working distance microscopic objective, an electrically tunable lens and focused reflectance illumination. The diver-deployed instrument permits studies of both spatial and temporal processes such as the algal colonization and overgrowth of bleaching corals, as well as coral polyp behaviour and interspecific competition. By enabling in situ observations at previously unattainable scales, this instrument can provide important new insights into micro-scale processes in benthic ecosystems that shape observed patterns at much larger scales.

  14. Final report: In situ radio frequency heating demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Jarosch, T.R.; Beleski, R.J.; Faust, D.

    1994-01-05

    A field demonstration of in situ radio frequency heating was performed at the Savannah River Site (SRS) as part of the US Department of Energy-Office of Technology Development`s Integrated Demonstration. The objective of the demonstration was to investigate the effectiveness of in situ radio frequency (RF) heating as an enhancement to vacuum extraction of residual solvents (primarily trichloroethylene and perchloroethylene) held in vadose zone clay deposits. Conventional soil vacuum extraction techniques are mass transfer limited because of the low permeabilities of the clays. By selectively heating the clays to temperatures at or above 100{degrees}C, the release or transport of the solvent vapors will be enhanced as a result of several factors including an increase in the contaminant vapor pressure and diffusivity and an increase in the effective permeability of the formation with the release of water vapor.

  15. In Situ Electron Energy Loss Spectroscopy in Liquids

    CERN Document Server

    Holtz, Megan E; Gao, Jie; Abruña, Héctor D; Muller, David A

    2012-01-01

    In situ scanning transmission electron microscopy (STEM) through liquids is a promising approach for exploring biological and materials processes. However, options for in situ chemical identification are limited: X-ray analysis is precluded because the holder shadows the detector, and electron energy loss spectroscopy (EELS) is degraded by multiple scattering events in thick layers. Here, we explore the limits of EELS for studying chemical reactions in their native environments in real time and on the nanometer scale. The determination of the local electron density, optical gap and thickness of the liquid layer by valence EELS is demonstrated for liquids. By comparing theoretical and experimental plasmon energies, we find that liquids appear to follow the free-electron model that has been previously established for solids. Signals at energies below the optical gap and plasmon energy of the liquid provide a high signal-to-background ratio as demonstrated for LiFePO4 in aqueous solution. The potential for using...

  16. OpenMC In Situ Source Convergence Detection

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, Garrett Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of California, Davis, CA (United States); Dutta, Soumya [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); The Ohio State Univ., Columbus, OH (United States); Woodring, Jonathan Lee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-07

    We designed and implemented an in situ version of particle source convergence for the OpenMC particle transport simulator. OpenMC is a Monte Carlo based-particle simulator for neutron criticality calculations. For the transport simulation to be accurate, source particles must converge on a spatial distribution. Typically, convergence is obtained by iterating the simulation by a user-settable, fixed number of steps, and it is assumed that convergence is achieved. We instead implement a method to detect convergence, using the stochastic oscillator for identifying convergence of source particles based on their accumulated Shannon Entropy. Using our in situ convergence detection, we are able to detect and begin tallying results for the full simulation once the proper source distribution has been confirmed. Our method ensures that the simulation is not started too early, by a user setting too optimistic parameters, or too late, by setting too conservative a parameter.

  17. Preparation of nanoanatase and its in situ XRD study

    Institute of Scientific and Technical Information of China (English)

    LI Guo-hua; ZHENG Yi-fan; MA Chun-an; TIAN Wei

    2008-01-01

    Phase pure nanoanatase was prepared by sol-hydrolysis of TiCl4 in ammonium sulfate solution. In order to investigate the microstrain effect on nanoanatase transformation, the transformation process of the sample was investigated by in situ XRD. Based on the in situ XRD data, a variation of the diameter and its distribution, and the microstrain of nanotitania particles were estimated with Win XRD software. The results show that the transformation process of nanoanatase can be divided into four steps; a rate competition between the anatase growth and the transformation from anatase to rutile determines the diameter and its size distribution of anatase nanoparticles; and during the phase transformation, the microstrain determines the rates of anatase growth and its transformation.

  18. AN INSIGHT TO OPHTHALMIC IN-SITU GEL: AN OVERVIEW

    Directory of Open Access Journals (Sweden)

    Thakur Reeta Rani

    2012-03-01

    Full Text Available Ocular drug delivery has been a major challenging and interesting field for the pharmaceutical scientists due to unique anatomy and physiology of the eye. The major problem encountered in ocular drug delivery is the rapid loss of the drug through lachrymal drainage which results in poor bioavailability and therapeutic response of the drug. There are some static (different layers of the eye i.e. cornea, sclera, retina and dynamic (blood aqueous and blood retinal barrier barriers which also affect the bioavailability of the drug. In-situ gels are the liquid preparations which upon instillation undergoes the phase transition in cul-de sac in the eyes to form a viscous gel and this occurs due to environmental changes in the eye ( due to change in pH, change in temperature and ion-induced. This review is to specify the different phase transition process and polymers used in forming in-situ gelling system.

  19. In-situ glyoxalization during biosynthesis of bacterial cellulose.

    Science.gov (United States)

    Castro, Cristina; Cordeiro, Nereida; Faria, Marisa; Zuluaga, Robin; Putaux, Jean-Luc; Filpponen, Ilari; Velez, Lina; Rojas, Orlando J; Gañán, Piedad

    2015-08-01

    A novel method to synthesize highly crosslinked bacterial cellulose (BC) is reported. The glyoxalization is started in-situ, in the culture medium during biosynthesis of cellulose by Gluconacetobacter medellensis bacteria. Strong crosslinked networks were formed in the contact areas between extruded cellulose ribbons by reaction with the glyoxal precursors. The crystalline structure of cellulose was preserved while the acidic component of the surface energy was reduced. As a consequence, its predominant acidic character and the relative contribution of the dispersive component increased, endowing the BC network with a higher hydrophobicity. This route for in-situ crosslinking is expected to facilitate other modifications upon biosynthesis of cellulose ribbons by microorganisms and to engineer the strength and surface energy of their networks.

  20. In situ testing of waste glass in clay

    Energy Technology Data Exchange (ETDEWEB)

    Van Iseghem, P.Ph. [SCK/CEN, Mol (Belgium)

    1994-12-31

    The actual status of an in-situ test programme exposing different waste glass samples directly to Boom clay is reviewed. Corrosion test tubes have been retrieved after residence for 5 years at 16{degrees}C, 2 years at 90{degrees}, and 5 years at 170{degrees}C. The corrosion is interpreted in terms of mass loss, surface analysis by SEM and profiling by EPMA and SIMS. At 16{degrees}C, glasses dissolve about 0.02-0.08 {mu}m per year. At higher temperature dissolution is more than two orders of magnitude larger. A good agreement is obtained between the mass losses and the surface analyses. The advantages and limitations of the Belgian in-situ tests are compared with the conclusions of an international expert group.

  1. Application of Genomic In Situ Hybridization in Horticultural Science

    Directory of Open Access Journals (Sweden)

    Fahad Ramzan

    2017-01-01

    Full Text Available Molecular cytogenetic techniques, such as in situ hybridization methods, are admirable tools to analyze the genomic structure and function, chromosome constituents, recombination patterns, alien gene introgression, genome evolution, aneuploidy, and polyploidy and also genome constitution visualization and chromosome discrimination from different genomes in allopolyploids of various horticultural crops. Using GISH advancement as multicolor detection is a significant approach to analyze the small and numerous chromosomes in fruit species, for example, Diospyros hybrids. This analytical technique has proved to be the most exact and effective way for hybrid status confirmation and helps remarkably to distinguish donor parental genomes in hybrids such as Clivia, Rhododendron, and Lycoris ornamental hybrids. The genome characterization facilitates in hybrid selection having potential desirable characteristics during the early hybridization breeding, as this technique expedites to detect introgressed sequence chromosomes. This review study epitomizes applications and advancements of genomic in situ hybridization (GISH techniques in horticultural plants.

  2. Armaduras de cosido entre hormigones prefabricados y ejecutados in situ

    Directory of Open Access Journals (Sweden)

    Solas, Andrés

    1988-04-01

    Full Text Available This article deals with the study of seam reinforcements between two concretes of different types which make up a compound element prefabricated and made in situ. The advantage of this type of construction is that the individual units can be made, transported and erected more easily, although some problems may arise. These facts receive special reference throughout the article.

    Este artículo trata sobre el estudio de las armaduras de cosido entre dos hormigones, de distinta naturaleza, que componen un elemento compuesto prefabricado y ejecutado in situ. La ventaja de este tipo de construcciones es que unidades individuales pueden ser hechas, transportadas y erigidas con mayor facilidad, pudiéndose derivar también algún problema. De todo ello se hace especial referencia a lo largo del artículo.

  3. Toughness of Bulk Metallic Glasses

    Directory of Open Access Journals (Sweden)

    Shantanu V. Madge

    2015-07-01

    Full Text Available Bulk metallic glasses (BMGs have desirable properties like high strength and low modulus, but their toughness can show much variation, depending on the kind of test as well as alloy chemistry. This article reviews the type of toughness tests commonly performed and the factors influencing the data obtained. It appears that even the less-tough metallic glasses are tougher than oxide glasses. The current theories describing the links between toughness and material parameters, including elastic constants and alloy chemistry (ordering in the glass, are discussed. Based on the current literature, a few important issues for further work are identified.

  4. The in-situ characterization of a transesterification reaction using electrical impedance spectroscopy

    Science.gov (United States)

    Cho, Sungjin

    Impedance Spectroscopy has been used in the in-situ monitoring of a transesterfication reaction of soybean biodiesel. This paper describes the application of Electrical Impedance Spectroscopy (EIS) to observe and characterize the transesterfication reaction and its interfacial behavior phenomena electrically. In particular, the dielectric properties of soybean biodiesel were measured at broad range frequencies from 10-2 to 106 Hz at different temperatures, methanol molar ratio to biodiesel, concentration of catalyst and reaction time. Measurement of dielectric property have provided an important approach to understanding the structure of matter. Measurements of the dielectric properties are a reliable and efficient method for evaluating the biodiesel production to determine their quality and yield for reducing the production cost. The dielectric constant (epsilon') and loss (epsilon") are the most convenient indicators for quality control in commercial biodiesel manufacturing. Dielectric properties were correlated with chemically measured changes in soybean oil such as free fatty acids, amount of catalyst and alcohols at different temperatures as well as reaction times. It was observed that there is a good correlation between the dielectric constant (epsilon') and loss (epsilon") in soybean biodiesel. The result indicated that the dielectric properties increased with the (1) increasing temperature (2) increasing methanol; (3) increasing catalyst; (4) increasing reaction time. Dielectric properties was a useful index for the rapid quality evaluation of soybean biodiesel. Dielectric properties were compared to conventional methods of analysis (Infrared Spectroscopy) for evaluating the quality of soybean biodiesel. The results indicated that dielectric constant and dielectric loss are essential measurement for predicting the best biodiesel yield. Moreover, the electrical impedance parameters such as bulk resistance (Rb), bulk capacitance (Cb) and time constant(tau b

  5. Fiber field-effect device via in situ channel crystallization.

    Science.gov (United States)

    Danto, Sylvain; Sorin, Fabien; Orf, Nicholas D; Wang, Zheng; Speakman, Scott A; Joannopoulos, John D; Fink, Yoel

    2010-10-01

    The in situ crystallization of the incorporated amorphous semiconductor within the multimaterial fiber device yields a large decrease in defect density and a concomitant five-order-of-magnitude decrease in resistivity of the novel metal-insulator-crystalline semiconductor structure. Using a post-drawing crystallization process, the first tens-of-meters-long single-fiber field-effect device is demonstrated. This work opens significant opportunities for incorporating higher functionality in functional fibers and fabrics.

  6. In situ transmission electron microscopy for magnetic nanostructures

    DEFF Research Database (Denmark)

    Ngo, Duc-The; Kuhn, Luise Theil

    2016-01-01

    Nanomagnetism is a subject of great interest because of both application and fundamental aspects in which understanding of the physical and electromagnetic structure of magnetic nanostructures is essential to explore the magnetic properties. Transmission electron microscopy (TEM) is a powerful tool......-structure correlation. This paper aims at reviewing and discussing in situ TEM magnetic imaging studies, including Lorentz microscopy and electron holography in TEM, applied to the research of magnetic nanostructures....

  7. In Situ XAS of the Solvothermal Decomposition of Dithiocarbamate Complexes

    Science.gov (United States)

    Islam, Husn-Ubayda; Roffey, Anna; Hollingsworth, Nathan; Catlow, Richard; Wolthers, Mariette; De Leeuw, Nora; Bras, Wim; Sankar, Gopinathan; Hogarth, Graeme

    2013-04-01

    An in situ XAS study of the solvothermal decomposition of iron and nickel dithiocarbamate complexes was performed in order to gain understanding of the decomposition mechanisms. This work has given insight into the steps involved in the decomposition, showing variation in reaction pathways between the iron and nickel dithiocarbamates, and the non-innocent role of oleylamine as the solvent and capping agent in the reaction.

  8. Formulation Development and Evaluation of Nepafenac Novel In Situ Gel

    Directory of Open Access Journals (Sweden)

    Aravinda Nalla

    2016-11-01

    Full Text Available The aim of present study was to formulate and evaluate Nepafenac liposomal in situ gel. Liposomes were formulated in different ratios using soya lecithin and cholesterol using Rotary Flash Evaporation method. Liposomes were evaluated for drug entrapment efficiency, %entrapment efficiency, particle size analysis, zeta potential and in vitro release studies. Optimized liposomes (F4 were developed into in situ gels. The thermo reversible liposomal in situ gels of Nepafenac were prepared by using poloxamer 407 and with mucoadhesive polymers like HPMC E15 and chitosan. Formulations were sterilized by autoclaving at 121⁰C, at 15 lb pressure for 20 min. The formulations were evaluated for drug content, clarity, pH, gelation temperature, gelation capacity, viscosity, in-vitro drug release studies. Drug and Polymer incompatibilities were evaluated using FTIR spectrophotometer. The drug content of the formulations was in the range 83%-92%. pH of the formulations was in the range 6.43 to 7.42, gelation temperature was in the range 27.5⁰C-40⁰C. In Vitro drug release was in the range of 78%-99% within 12 hours, the extent of gelation and consequently the release of Nepafenac depended on the concentration of polymers used. Nepafenac was released slowly from gels, for a period of 12 hours. Formulation PC5 with poloxamer 407 (18% w/w and chitosan (0.3% w/w was found to be suitable as it released 78% of drug for a period of 12 hours. Poloxamer 407/chitosan (PC5 combination was found to have optimum pH and gelation temperature which is required for an in situ gel drug delivery system.

  9. Radio frequency heating for in-situ remediation of DNAPL

    Energy Technology Data Exchange (ETDEWEB)

    Kasevich, R.S. [KAI Technologies, Woburn, MA (United States)

    1996-08-01

    In-situ radio frequency (RF) heating technology for treating soils contaminated with dense nonaqueous phase liquids (DNAPLs) is described. RF imparts heat to non-conducting materials through the application of carefully controlled RF transmissions, improving contaminant flow characteristics and facilitating separation and removal from subsurface soils. The paper outlines advantages and limitations of RF remediation, process operations, general technology considerations, low permeability media considerations, commercial availability, and costs. Two case histories of RF remediation are briefly summarized. 13 refs., 10 figs.

  10. Ductal carcinoma in situ - update on risk assessment and management.

    Science.gov (United States)

    Pang, Jia-Min B; Gorringe, Kylie L; Fox, Stephen B

    2016-01-01

    Ductal carcinoma in situ (DCIS) accounts for ~20-25% of breast cancers. While DCIS is not life-threatening, it may progress to invasive carcinoma over time, and treatment intended to prevent invasive progression may itself cause significant morbidity. Accurate risk assessment is therefore necessary to avoid over- or undertreatment of an individual patient. In this review we will outline the evidence for current management of DCIS, discuss approaches to DCIS risk assessment and challenges facing identification of novel DCIS biomarkers.

  11. In situ observation of the formation of FeSe

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Wulff, Anders Christian; Yue, Zhao;

    2011-01-01

    The formation of the FeSe compound from a mixture of Fe and Se powders encased in a composite Cu/Nb sheath was studied in situ by means of high-energy synchrotron x-ray diffraction. Tetragonal beta-FeSe does not seem to form directly from the starting elements. Instead, a sequence of FeSe2, Fe3Se4...

  12. Electron Microscopy of Living Cells During in Situ Fluorescence Microscopy.

    Science.gov (United States)

    Liv, Nalan; van Oosten Slingeland, Daan S B; Baudoin, Jean-Pierre; Kruit, Pieter; Piston, David W; Hoogenboom, Jacob P

    2016-01-26

    We present an approach toward dynamic nanoimaging: live fluorescence of cells encapsulated in a bionanoreactor is complemented with in situ scanning electron microscopy (SEM) on an integrated microscope. This allows us to take SEM snapshots on-demand, that is, at a specific location in time, at a desired region of interest, guided by the dynamic fluorescence imaging. We show that this approach enables direct visualization, with EM resolution, of the distribution of bioconjugated quantum dots on cellular extensions during uptake and internalization.

  13. In-Situ Biological Reclamation of Contaminated Ground Water

    Science.gov (United States)

    1992-01-01

    laboratory scale methanogenic anaerobic filter treating rum distillery wastewater . The liquid detention time in the second column was two days. Having the...waste mining and in-situ mining) Non-waste Land application Materials transport and transfer Wastewater (e.g, spray irrigation) operations Vastewater...the use of biological treatment for domestic and industrial wastewaters is a common practice for many municipalities across the United Itates, the use

  14. In-situ measurements of the radioactive fallout deposit

    Science.gov (United States)

    Korun, M.; Martinčič, R.; Pucelj, B.

    1991-02-01

    An improved method to determine radionuclide concentrations in soil and the radioactive fallout deposit is presented. The approach is based on in-situ gamma-ray spectrometric measurements performed with a portable high resolution gamma spectrometer and on calculations of the depth distribution based on the energy dependence of the attenuation of gamma rays in soil. The results are compared with laboratory analysis of collected soil samples.

  15. Selection of electron acceptors and strategies for in situ bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Norris, R.D. [Eckenfelder, Inc., Nashville, TN (United States)

    1995-12-31

    The most critical aspect of designing in situ bioremediation systems is, typically, the selection and method of delivery of the electron acceptor. Nitrate, sulfate, and several forms of oxygen can be introduced, depending on the contaminants and the site conditions. Oxygen can be added as air, pure oxygen, hydrogen peroxide, or an oxygen release compound. Simplistic cost calculations can illustrate the advantages of some methods over others, providing technical requirements can be met.

  16. STREPTOCOCCUS PNEUMONIAE KERATITIS FOLLOWING LASER IN SITU KERATOMILEUSIS

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    A 22-year-old man underwent bilateral laser in situ keratomileusis and developed Streptococcus pneumoniae keratitis after surgery.This complication occurred one day after the procedure in both eyes.Topical and systemic antibiotics were promptly administered.Bacterial culture was performed following corneal flap lift and scraping of the lesions.Afterwards,the therapeutic regimen was readjusted according to the culture results.Streptococcus pneumoniae was identified from the culture.Three months after the sur...

  17. Ignition technique for an in situ oil shale retort

    Science.gov (United States)

    Cha, Chang Y.

    1983-01-01

    A generally flat combustion zone is formed across the entire horizontal cross-section of a fragmented permeable mass of formation particles formed in an in situ oil shale retort. The flat combustion zone is formed by either sequentially igniting regions of the surface of the fragmented permeable mass at successively lower elevations or by igniting the entire surface of the fragmented permeable mass and controlling the rate of advance of various portions of the combustion zone.

  18. Development of the integrated in situ lasagna process

    Energy Technology Data Exchange (ETDEWEB)

    Ho, S.; Athmer, C.; Sheridan, P. [Monsanto Company, St. Louis, MO (United States)] [and others

    1995-10-01

    Contamination in deep, low permeability soils poses a significant technical challenge to in-situ remediation efforts. Poor accessibility to the contaminants and difficulty in uniform delivery of treatment reagents have rendered existing in-situ methods such as bioremediation, vapor extraction, and pump and treat rather ineffective when applied to low permeability soils present at many contaminated sites. Recently the use of electrokinetics as an in situ method for soil remediation has received increasing attention due to its unique applicability to low-permeability soils. Electrokinetics includes the transport of water (electroosmosis) as well as ions (electromigration) as a result of an applied electric field. For remedial applications, water is typically introduced into the soil at the anode to replenish the water flowing towards the cathode due to electroosmosis. The water flow is utilized to flush organic contaminants from the subsurface soil to the ground surface at the cathode region for further treatment or disposal. This report describes a treatment process under development termed the LASAGNA process which incorporates electrokinetics, along with the establishment of degradation zones, for pollutant removal.

  19. In situ optical absorption mercury continuous emission monitor.

    Science.gov (United States)

    Thiebaud, Jérôme; Thomson, Murray J; Mani, Reza; Morrow, William H; Morris, Eric A; Jia, Charles Q

    2009-12-15

    This paper reports the development of an in situ continuous emission monitor (CEM) for measuring elemental mercury (Hg(0)) concentration in the exhaust stream of coal-fired power plants. The instrument is based on the ultraviolet atomic absorption of a mercury lamp emission line by elemental mercury and a light-emitting diode (LED) background correction system. This approach allows an in situ measurement since the absorption of other species such as SO(2) can be removed to monitor the Hg(0) contribution only. Proof of concept was established through a laboratory-based investigation, and a limit of detection, [Hg(0)](min), of 2 microg/m(3) was measured for a 1-min averaged sample and an absorption path length of 49 cm. [Hg(0)](min) is anticipated to be better than 0.2 microg/m(3) across a 7 m diameter stack. Finally, the apparatus was field-tested in a 230 MW coal-fired power plant. The operability of the measurement in real conditions was demonstrated, leading to the first Hg(0) concentration values recorded by the in situ CEM. Comparison with an accepted standard method is required for validation.

  20. Combining Remote Sensing with in situ Measurements for Riverine Characterization

    Science.gov (United States)

    Calantoni, J.; Palmsten, M. L.; Simeonov, J.; Dobson, D. W.; Zarske, K.; Puleo, J. A.; Holland, K. T.

    2014-12-01

    At the U.S. Naval Research Laboratory we are employing a wide variety of novel remote sensing techniques combined with traditional in situ sampling to characterize riverine hydrodynamics and morphodynamics. Surface currents were estimated from particle image velocimetry (PIV) using imagery from visible to infrared bands, from both fixed and airborne platforms. Terrestrial LIDAR has been used for subaerial mapping from a fixed platform. Additionally, LIDAR has been combined with hydrographic surveying (multibeam) in mobile scanning mode using a small boat. Hydrographic surveying (side scan) has also been performed using underwater autonomous vehicles. Surface drifters have been deployed in combination with a remotely operated, floating acoustic Doppler current profiler. Other fixed platform, in situ sensors, such as pencil beam and sector scanning sonars, acoustic Doppler velocimeters, and water level sensors have been deployed. We will present an overview of a variety of measurements from different rivers around the world focusing on validation examples of remotely sensed quantities with more traditional in situ measurements. Finally, we will discuss long-term goals to use remotely sensed data within an integrated environmental modeling framework.

  1. In situ detection of anaerobic alkane metabolites in subsurface environments.

    Science.gov (United States)

    Agrawal, Akhil; Gieg, Lisa M

    2013-01-01

    Alkanes comprise a substantial fraction of crude oil and refined fuels. As such, they are prevalent within deep subsurface fossil fuel deposits and in shallow subsurface environments such as aquifers that are contaminated with hydrocarbons. These environments are typically anaerobic, and host diverse microbial communities that can potentially use alkanes as substrates. Anaerobic alkane biodegradation has been reported to occur under nitrate-reducing, sulfate-reducing, and methanogenic conditions. Elucidating the pathways of anaerobic alkane metabolism has been of interest in order to understand how microbes can be used to remediate contaminated sites. Alkane activation primarily occurs by addition to fumarate, yielding alkylsuccinates, unique anaerobic metabolites that can be used to indicate in situ anaerobic alkane metabolism. These metabolites have been detected in hydrocarbon-contaminated shallow aquifers, offering strong evidence for intrinsic anaerobic bioremediation. Recently, studies have also revealed that alkylsuccinates are present in oil and coal seam production waters, indicating that anaerobic microbial communities can utilize alkanes in these deeper subsurface environments. In many crude oil reservoirs, the in situ anaerobic metabolism of hydrocarbons such as alkanes may be contributing to modern-day detrimental effects such as oilfield souring, or may lead to more beneficial technologies such as enhanced energy recovery from mature oilfields. In this review, we briefly describe the key metabolic pathways for anaerobic alkane (including n-alkanes, isoalkanes, and cyclic alkanes) metabolism and highlight several field reports wherein alkylsuccinates have provided evidence for anaerobic in situ alkane metabolism in shallow and deep subsurface environments.

  2. In situ detection of anaerobic alkane metabolites in subsurface environments

    Directory of Open Access Journals (Sweden)

    Lisa eGieg

    2013-06-01

    Full Text Available Alkanes comprise a substantial fraction of crude oil and refined fuels. As such, they are prevalent within deep subsurface fossil fuel deposits and in shallow subsurface environments such as aquifers that are contaminated with hydrocarbons. These environments are typically anaerobic, and host diverse microbial communities that can potentially use alkanes as substrates. Anaerobic alkane biodegradation has been reported to occur under nitrate-reducing, sulfate-reducing, and methanogenic conditions. Elucidating the pathways of anaerobic alkane metabolism has been of interest in order to understand how microbes can be used to remediate contaminated sites. Alkane activation primarily occurs by addition to fumarate, yielding alkylsuccinates, unique anaerobic metabolites that can be used to indicate in situ anaerobic alkane metabolism. These metabolites have been detected in hydrocarbon-contaminated shallow aquifers, offering strong evidence for intrinsic anaerobic bioremediation. Recently, studies have also revealed that alkylsuccinates are present in oil and coal seam production waters, indicating that anaerobic microbial communities can utilize alkanes in these deeper subsurface environments. In many crude oil reservoirs, the in situ anaerobic metabolism of hydrocarbons such as alkanes may be contibuting to modern-day detrimental effects such as oilfield souring, or may lead to more benefical technologies such as enhanced energy recovery from mature oilfields. In this review, we briefly describe the key metabolic pathways for anaerobic alkane (including n-alkanes, isoalkanes, and cyclic alkanes metabolism and highlight several field reports wherein alkylsuccinates have provided evidence for anaerobic in situ alkane metabolism in shallow and deep subsurface environments.

  3. In Situ Remediation Integrated Program: FY 1994 program summary

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-04-01

    The US Department of Energy (DOE) established the Office of Technology Development (EM-50) as an element of the Office of Environmental Management (EM) in November 1989. In an effort to focus resources and address priority needs, EM-50 introduced the concept of integrated programs (IPs) and integrated demonstrations (IDs). The In Situ Remediation Integrated Program (ISR IP) focuses research and development on the in-place treatment of contaminated environmental media, such as soil and groundwater, and the containment of contaminants to prevent the contaminants from spreading through the environment. Using in situ remediation technologies to clean up DOE sites minimizes adverse health effects on workers and the public by reducing contact exposure. The technologies also reduce cleanup costs by orders of magnitude. This report summarizes project work conducted in FY 1994 under the ISR IP in three major areas: treatment (bioremediation), treatment (physical/chemical), and containment technologies. Buried waste, contaminated soils and groundwater, and containerized waste are all candidates for in situ remediation. Contaminants include radioactive waste, volatile and nonvolatile organics, heavy metals, nitrates, and explosive materials.

  4. Automated in situ brain imaging for mapping the Drosophila connectome.

    Science.gov (United States)

    Lin, Chi-Wen; Lin, Hsuan-Wen; Chiu, Mei-Tzu; Shih, Yung-Hsin; Wang, Ting-Yuan; Chang, Hsiu-Ming; Chiang, Ann-Shyn

    2015-01-01

    Mapping the connectome, a wiring diagram of the entire brain, requires large-scale imaging of numerous single neurons with diverse morphology. It is a formidable challenge to reassemble these neurons into a virtual brain and correlate their structural networks with neuronal activities, which are measured in different experiments to analyze the informational flow in the brain. Here, we report an in situ brain imaging technique called Fly Head Array Slice Tomography (FHAST), which permits the reconstruction of structural and functional data to generate an integrative connectome in Drosophila. Using FHAST, the head capsules of an array of flies can be opened with a single vibratome sectioning to expose the brains, replacing the painstaking and inconsistent brain dissection process. FHAST can reveal in situ brain neuroanatomy with minimal distortion to neuronal morphology and maintain intact neuronal connections to peripheral sensory organs. Most importantly, it enables the automated 3D imaging of 100 intact fly brains in each experiment. The established head model with in situ brain neuroanatomy allows functional data to be accurately registered and associated with 3D images of single neurons. These integrative data can then be shared, searched, visualized, and analyzed for understanding how brain-wide activities in different neurons within the same circuit function together to control complex behaviors.

  5. Regulation of In Situ to Invasive Breast CarcinomaTransition

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Min; Carroll, Danielle K.; Weremowicz, Stanislawa; Chen,Haiyan; Carrasco, Daniel; Richardson, Andrea; Bissell, Mina; Violette,Shelia; Gelman, Rebecca S.; Schnitt, Stuart; Polyak, Kornelia

    2007-03-13

    The transition of ductal carcinoma in situ (DCIS) to invasive carcinoma is a key event in breast tumor progression that is poorly understood. Comparative molecular analysis of tumor epithelial cells from in situ and invasive tumors has failed to identify consistent tumor stage-specific differences. However, the myoepithelial cell layer, present only in DCIS, is a key distinguishing and diagnostic feature. To determine the contribution of non-epithelial cells to tumor progression, we analyzed the role of myoepithelial cells and fibroblasts in the progression of in situ carcinomas using a xenograft model of human DCIS. Progression to invasion was promoted by fibroblasts, but inhibited by normal myoepithelial cells. The invasive tumor cells from these progressed lesions formed DCIS rather than invasive cancers when re-injected into naive mice. Molecular profiles of myoepithelial and epithelial cells isolated from primary normal and cancerous human breast tissue samples corroborated findings obtained in the xenograft model. These results provide the proof of principle that breast tumor progression could occur in the absence of additional genetic alterations and that tumor growth and progression could be controlled by replacement of normal myoepithelial inhibitory signals.

  6. Regulation of in situ to invasive breast carcinoma transition

    Energy Technology Data Exchange (ETDEWEB)

    Polyak, Kornelia; Hu, Min; Yao, Jun; Carroll, Danielle K.; Weremowicz, Stanislawa; Chen, Haiyan; Carrasco, Daniel; Richardson, Andrea; Violette, Shelia; Gelman, Rebecca S.; Bissell, Mina J.; Schnitt, Stuart; Polyak, Kornelia

    2008-05-07

    The transition of ductal carcinoma in situ (DCIS) to invasive carcinoma is a key event in breast tumor progression that is poorly understood. Comparative molecular analysis of tumor epithelial cells from in situ and invasive tumors has failed to identify consistent tumor stage-specific differences. However, the myoepithelial cell layer, present only in DCIS, is a key distinguishing and diagnostic feature. To determine the contribution of non-epithelial cells to tumor progression, we analyzed the role of myoepithelial cells and fibroblasts in the progression of in situ carcinomas using a xenograft model of human DCIS. Progression to invasion was promoted by fibroblasts, but inhibited by normal myoepithelial cells. The invasive tumor cells from these progressed lesions formed DCIS rather than invasive cancers when re-injected into naive mice. Molecular profiles of myoepithelial and epithelial cells isolated from primary normal and cancerous human breast tissue samples corroborated findings obtained in the xenograft model. These results provide the proof of principle that breast tumor progression could occur in the absence of additional genetic alterations and that tumor growth and progression could be controlled by replacement of normal myoepithelial inhibitory signals.

  7. In situ aerobic cometabolism of chlorinated solvents: a review.

    Science.gov (United States)

    Frascari, Dario; Zanaroli, Giulio; Danko, Anthony S

    2015-01-01

    The possible approaches for in situ aerobic cometabolism of aquifers and vadose zones contaminated by chlorinated solvents are critically evaluated. Bioaugmentation of resting-cells previously grown in a fermenter and in-well addition of oxygen and growth substrate appear to be the most promising approaches for aquifer bioremediation. Other solutions involving the sparging of air lead to satisfactory pollutant removals, but must be integrated by the extraction and subsequent treatment of vapors to avoid the dispersion of volatile chlorinated solvents in the atmosphere. Cometabolic bioventing is the only possible approach for the aerobic cometabolic bioremediation of the vadose zone. The examined studies indicate that in situ aerobic cometabolism leads to the biodegradation of a wide range of chlorinated solvents within remediation times that vary between 1 and 17 months. Numerous studies include a simulation of the experimental field data. The modeling of the process attained a high reliability, and represents a crucial tool for the elaboration of field data obtained in pilot tests and for the design of the full-scale systems. Further research is needed to attain higher concentrations of chlorinated solvent degrading microbes and more reliable cost estimates. Lastly, a procedure for the design of full-scale in situ aerobic cometabolic bioremediation processes is proposed.

  8. Histological Grading in Ductal Carcinoma in Situ of the Breast

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To study the significance of histological grading as a prognostic factor in ductal carcinoma in situ of the breast. Methods: According to the Van Nuy's classification, 32 cases of ductal carcinoma in situ (DCIS) of the breast were divided into three groups. Results: Low grade (well differentiated, low grade DCIS) 12 patients (37.5%); Intermediate grade, 9 patients (28.1%); High grade (poorly differentiated DCIS) 11 patients (34.4%). Among the high grade DCIS, the histologic subtypes were comedo (9 patients), micropapillary (1 patient) and solid (1 patient). The positive expression of c-erbB-2, p53 and MIB-1 in high grade DCIS was higher than that in intermediate and low grade DCIS. The difference between high grade and low grade DCIS was significant (p<0.05). The expression of ER in high grade DCIS was lower than that in intermediate and low grade DCIS. Conclusions: Histological grading of breast ductal carcinoma in situ may be a good prognostic factor.

  9. The in situ saphenous vein bypass graft: radiologic aspects.

    Science.gov (United States)

    Schwarz, W; Nozick, J; Richmand, D; Rodgers, B; Simpson, A; Argila, C; Honickman, S

    1986-03-01

    The use of the in situ saphenous vein for bypassing arterial occlusions in the lower extremities appears to have a higher patency rate than other bypass procedures but presents unique technical problems, such as lysing valves and occluding venous tributaries. Forty-four patients undergoing in situ bypasses had preoperative arteriograms. Special attention was paid to the small runoff vessels around the ankle, which are not suitable for reversed bypass procedures but may be adequate for in situ bypasses. Eight patients also had preoperative saphenous venograms, which revealed surgically important abnormalities in six cases. Postoperative arteriograms obtained within 2 weeks in 10 patients and within 2-12 months in 15 patients revealed persistent arteriovenous fistulas in four patients, stenoses in nine, occlusions in five, and progressive disease in the nonbypassed arteries in five patients. Early recognition of these problems led to 11 surgical repairs; nine repairs used the interventional radiologic procedures of balloon angioplasty, transcatheter embolization, and catheter thrombolysis. In this group of 44 patients, five patients died with patent bypasses and three patients required amputation despite functioning bypasses. Only four amputations were attributed to bypass failure. This low figure may be due to the close cooperation of the vascular surgeons and the vascular radiologists in dealing with these complicated cases.

  10. LEAKING UNDERGROUND STORAGE TANKS: REMEDIATION WITH EMPHASIS ON IN SITU BIORESTORATION

    Science.gov (United States)

    The current literature indicates that in situ biorestoration has great potential for remediation of aquifers contaminated by leaking underground storage tanks. In situ aquifer restoration involves the enhancement of the indigenous microflora to degrade subsurface pollutants. The ...

  11. AirCore Reusable InSitu Sampler for CO2 and Trace Gas Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A novel design for an in situ air sampling sensor for CO2 and trace gases is proposed. The sensor, named AirCore, provides the advantages of existing in situ...

  12. Reusable In Situ AirCore System for CO2 and Trace Gas Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A novel design for an in situ atmospheric sensor for CO2 and trace gases is proposed. The sensor, named AirCore, provides the advantages of existing in situ sensors...

  13. Rapid Optical Characterization Suite for in situ Target Analysis of Rock Surfaces Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ROCSTAR is an in situ instrument suite that can accomplish rapid mineral and molecular identification without sample preparation for in situ planetary exploration;...

  14. Parallel In Situ Indexing for Data-intensive Computing

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jinoh; Abbasi, Hasan; Chacon, Luis; Docan, Ciprian; Klasky, Scott; Liu, Qing; Podhorszki, Norbert; Shoshani, Arie; Wu, Kesheng

    2011-09-09

    As computing power increases exponentially, vast amount of data is created by many scientific re- search activities. However, the bandwidth for storing the data to disks and reading the data from disks has been improving at a much slower pace. These two trends produce an ever-widening data access gap. Our work brings together two distinct technologies to address this data access issue: indexing and in situ processing. From decades of database research literature, we know that indexing is an effective way to address the data access issue, particularly for accessing relatively small fraction of data records. As data sets increase in sizes, more and more analysts need to use selective data access, which makes indexing an even more important for improving data access. The challenge is that most implementations of in- dexing technology are embedded in large database management systems (DBMS), but most scientific datasets are not managed by any DBMS. In this work, we choose to include indexes with the scientific data instead of requiring the data to be loaded into a DBMS. We use compressed bitmap indexes from the FastBit software which are known to be highly effective for query-intensive workloads common to scientific data analysis. To use the indexes, we need to build them first. The index building procedure needs to access the whole data set and may also require a significant amount of compute time. In this work, we adapt the in situ processing technology to generate the indexes, thus removing the need of read- ing data from disks and to build indexes in parallel. The in situ data processing system used is ADIOS, a middleware for high-performance I/O. Our experimental results show that the indexes can improve the data access time up to 200 times depending on the fraction of data selected, and using in situ data processing system can effectively reduce the time needed to create the indexes, up to 10 times with our in situ technique when using identical parallel settings.

  15. High quality protein microarray using in situ protein purification

    Directory of Open Access Journals (Sweden)

    Fleischmann Robert D

    2009-08-01

    Full Text Available Abstract Background In the postgenomic era, high throughput protein expression and protein microarray technologies have progressed markedly permitting screening of therapeutic reagents and discovery of novel protein functions. Hexa-histidine is one of the most commonly used fusion tags for protein expression due to its small size and convenient purification via immobilized metal ion affinity chromatography (IMAC. This purification process has been adapted to the protein microarray format, but the quality of in situ His-tagged protein purification on slides has not been systematically evaluated. We established methods to determine the level of purification of such proteins on metal chelate-modified slide surfaces. Optimized in situ purification of His-tagged recombinant proteins has the potential to become the new gold standard for cost-effective generation of high-quality and high-density protein microarrays. Results Two slide surfaces were examined, chelated Cu2+ slides suspended on a polyethylene glycol (PEG coating and chelated Ni2+ slides immobilized on a support without PEG coating. Using PEG-coated chelated Cu2+ slides, consistently higher purities of recombinant proteins were measured. An optimized wash buffer (PBST composed of 10 mM phosphate buffer, 2.7 mM KCl, 140 mM NaCl and 0.05% Tween 20, pH 7.4, further improved protein purity levels. Using Escherichia coli cell lysates expressing 90 recombinant Streptococcus pneumoniae proteins, 73 proteins were successfully immobilized, and 66 proteins were in situ purified with greater than 90% purity. We identified several antigens among the in situ-purified proteins via assays with anti-S. pneumoniae rabbit antibodies and a human patient antiserum, as a demonstration project of large scale microarray-based immunoproteomics profiling. The methodology is compatible with higher throughput formats of in vivo protein expression, eliminates the need for resin-based purification and circumvents

  16. Comparison of Fluorescence In Situ Hybridization and Chromogenic In Situ Hybridization for Low and High Throughput HER2 Genetic Testing

    DEFF Research Database (Denmark)

    Poulsen, Tim S; Espersen, Maiken Lise Marcker; Kofoed, Vibeke;

    2013-01-01

    results show that the differences between the HER2 genetic assays do not have an effect on the analytic performance and the CISH technology is superior to high throughput HER2 genetic testing due to scanning speed, while the IQ-FISH may still be a choice for fast low throughput HER2 genetic testing.......The purpose was to evaluate and compare 5 different HER2 genetic assays with different characteristics that could affect the performance to analyze the human epidermal growth factor 2 (HER2) gene copy number under low and high throughput conditions. The study included 108 tissue samples from breast...... cancer patients with HER2 immunohistochemistry (IHC) results scored as 0/1+, 2+, and 3+. HER2 genetic status was analysed using chromogenic in situ hybridization (CISH) and fluorescence in situ hybridization (FISH). Scoring results were documented through digital image analysis. The cancer region...

  17. A Facile in Situ and UV Printing Process for Bioinspired Self-Cleaning Surfaces

    Directory of Open Access Journals (Sweden)

    Marina A. González Lazo

    2016-08-01

    Full Text Available A facile in situ and UV printing process was demonstrated to create self-cleaning synthetic replica of natural petals and leaves. The process relied on the spontaneous migration of a fluorinated acrylate surfactant (PFUA within a low-shrinkage acrylated hyperbranched polymer (HBP and its chemical immobilization at the polymer-air interface. Dilute concentrations of 1 wt. % PFUA saturated the polymer-air interface within 30 min, leading to a ten-fold increase of fluorine concentration at the surface compared with the initial bulk concentration and a water contact angle (WCA of 108°. A 200 ms flash of UV light was used to chemically crosslink the PFUA at the HBP surface prior to UV printing with a polydimethylsiloxane (PDMS negative template of red and yellow rose petals and lotus leaves. This flash immobilization hindered the reverse migration of PFUA within the bulk HBP upon contacting the PDMS template, and enabled to produce texturized surfaces with WCA well above 108°. The synthetic red rose petal was hydrophobic (WCA of 125° and exhibited the adhesive petal effect. It was not superhydrophobic due to insufficient concentration of fluorine at its surface, a result of the very large increase of the surface of the printed texture. The synthetic yellow rose petal was quasi-superhydrophobic (WCA of 143°, roll-off angle of 10° and its self-cleaning ability was not good also due to lack of fluorine. The synthetic lotus leaf did not accurately replicate the intricate nanotubular crystal structures of the plant. In spite of this, the fluorine concentration at the surface was high enough and the leaf was superhydrophobic (WCA of 151°, roll-off angle below 5° and also featured self-cleaning properties.

  18. In-situ identification of iron electrocoagulation speciation and application for natural organic matter (NOM) removal.

    Science.gov (United States)

    Dubrawski, Kristian L; Mohseni, Madjid

    2013-09-15

    In this work, iron speciation in electrocoagulation (EC) was studied to determine the impact of operating parameters on natural organic matter (NOM) removal from natural water. Two electrochemical EC parameters, current density (i) and charge loading rate (CLR), were investigated. Variation of these parameters led to a near unity current efficiency (φ = 0.957 ± 0.03), at any combination of i in a range of 1-25 mA/cm(2) and CLR in a range of 12-300 C/L/min. Higher i and CLR led to a higher bulk pH and limited the amount of dissolved oxygen (DO) reduced at the cathode surface due to mass transfer limitations. A low i (1 mA/cm(2)) and intermediate CLR (60 C/L/min) resulted in low bulk DO (<2.5 mg/L), where green rust (GR) was identified by in-situ Raman spectroscopy as the primary crystalline electrochemical product. Longer electrolysis times at higher i led to magnetite (Fe3O4) formation. Both higher (300 C/L/min) and lower (12 C/L/min) CLR values led to increased DO and/or increased pH, with lepidocrocite (γ-FeOOH) as the only crystalline species observed. The NOM removal of the three identified species was compared, with conditions leading to GR formation showing the greatest dissolved organic carbon removal, and highest removal of the low apparent molecular weight (<550 Da) chromophoric NOM fraction, determined by high performance size exclusion chromatography.

  19. The influence of physical state on shikimic acid ozonolysis: a case for in situ microspectroscopy

    Directory of Open Access Journals (Sweden)

    S. S. Steimer

    2014-03-01

    Full Text Available Atmospheric soluble organic aerosol material can become solid or semi-solid. Due to increasing viscosity and decreasing diffusivity, this can impact important processes such as gas uptake and reactivity within aerosols containing such substances. This work explores the dependence of shikimic acid ozonolysis on humidity and thereby viscosity. Shikimic acid, a proxy for oxygenated reactive organic material, reacts with O3 in a Criegee-type reaction. We used an environmental microreactor embedded in a Scanning Transmission X-ray Microscope (STXM to probe this oxidation process. This technique facilitates in situ measurements with single micron-sized particles and allows to obtain Near Edge X-ray Absorption Fine Structure (NEXAFS spectra with high spatial resolution. Thus, the chemical evolution of the interior of the particles can be followed under reaction conditions. The experiments show that the overall degradation rate of shikimic acid is depending on the relative humidity in a way that is controlled by the decreasing diffusivity of ozone with decreasing humidity. This decreasing diffusivity is most likely linked to the increasing viscosity of the shikimic acid-water mixture. The degradation rate was also depending on particle size, most congruent with a reacto-diffusion limited kinetic case where the reaction progresses only in a shallow layer within the bulk. No gradient in the shikimic acid concentration was observed within the bulk material at any humidity indicating that the diffusivity of shikimic acid is still high enough to allow its equilibration throughout the particles on the time scale of hours at higher humidity and that the thickness of the oxidized layer under dry conditions, where the particles are solid, is beyond the resolution of STXM.

  20. The influence of physical state on shikimic acid ozonolysis: a case for in situ microspectroscopy

    Science.gov (United States)

    Steimer, S. S.; Lampimäki, M.; Coz, E.; Grzinic, G.; Ammann, M.

    2014-10-01

    Atmospheric soluble organic aerosol material can become solid or semi-solid. Due to increasing viscosity and decreasing diffusivity, this can impact important processes such as gas uptake and reactivity within aerosols containing such substances. This work explores the dependence of shikimic acid ozonolysis on humidity and thereby viscosity. Shikimic acid, a proxy for oxygenated reactive organic material, reacts with O3 in a Criegee-type reaction. We used an environmental microreactor embedded in a scanning transmission X-ray microscope (STXM) to probe this oxidation process. This technique facilitates in situ measurements with single micron-sized particles and allows to obtain near-edge X-ray absorption fine structure (NEXAFS) spectra with high spatial resolution. Thus, the chemical evolution of the interior of the particles can be followed under reaction conditions. The experiments show that the overall degradation rate of shikimic acid is depending on the relative humidity in a way that is controlled by the decreasing diffusivity of ozone with decreasing humidity. This decreasing diffusivity is most likely linked to the increasing viscosity of the shikimic acid-water mixture. The degradation rate was also depending on particle size, most congruent with a reacto-diffusion limited kinetic case where the reaction progresses only in a shallow layer within the bulk. No gradient in the shikimic acid concentration was observed within the bulk material at any humidity indicating that the diffusivity of shikimic acid is still high enough to allow its equilibration throughout the particles on the timescale of hours at higher humidity and that the thickness of the oxidized layer under dry conditions, where the particles are solid, is beyond the resolution of STXM.

  1. The influence of physical state on shikimic acid ozonolysis: a case for in situ microspectroscopy

    Directory of Open Access Journals (Sweden)

    S. S. Steimer

    2014-10-01

    Full Text Available Atmospheric soluble organic aerosol material can become solid or semi-solid. Due to increasing viscosity and decreasing diffusivity, this can impact important processes such as gas uptake and reactivity within aerosols containing such substances. This work explores the dependence of shikimic acid ozonolysis on humidity and thereby viscosity. Shikimic acid, a proxy for oxygenated reactive organic material, reacts with O3 in a Criegee-type reaction. We used an environmental microreactor embedded in a scanning transmission X-ray microscope (STXM to probe this oxidation process. This technique facilitates in situ measurements with single micron-sized particles and allows to obtain near-edge X-ray absorption fine structure (NEXAFS spectra with high spatial resolution. Thus, the chemical evolution of the interior of the particles can be followed under reaction conditions. The experiments show that the overall degradation rate of shikimic acid is depending on the relative humidity in a way that is controlled by the decreasing diffusivity of ozone with decreasing humidity. This decreasing diffusivity is most likely linked to the increasing viscosity of the shikimic acid–water mixture. The degradation rate was also depending on particle size, most congruent with a reacto-diffusion limited kinetic case where the reaction progresses only in a shallow layer within the bulk. No gradient in the shikimic acid concentration was observed within the bulk material at any humidity indicating that the diffusivity of shikimic acid is still high enough to allow its equilibration throughout the particles on the timescale of hours at higher humidity and that the thickness of the oxidized layer under dry conditions, where the particles are solid, is beyond the resolution of STXM.

  2. Handling of bulk solids theory and practice

    CERN Document Server

    Shamlou, P A

    1990-01-01

    Handling of Bulk Solids provides a comprehensive discussion of the field of solids flow and handling in the process industries. Presentation of the subject follows classical lines of separate discussions for each topic, so each chapter is self-contained and can be read on its own. Topics discussed include bulk solids flow and handling properties; pressure profiles in bulk solids storage vessels; the design of storage silos for reliable discharge of bulk materials; gravity flow of particulate materials from storage vessels; pneumatic transportation of bulk solids; and the hazards of solid-mater

  3. Novel hard materials with controlled (W0.5Al0.5)C grain shapes: in-situ high pressure preparation and mechanical properties

    Institute of Scientific and Technical Information of China (English)

    Zhuhui QIAO; Xianfeng MA; Huaguo TANG; Wei ZHAO; Jianwei LIU

    2012-01-01

    A novel hard material with various (W0.5Al0.5)C grain shapes was successfully prepared through mechanical alloying and in-situ high-pressure sintering process.X-ray diffraction apparatus and scanning electron microscopy were used to characterize the phase and the microstructures of the samples.The novel hard materials with “fibrous”,“rounded” and “plate-like” grains,which do not contain sharp edges,have the improved mechanical properties.The bulk boundless (W0.5Al0.5)C hard material with various (W0.5Al0.5)C grain shapes possesses good mechanical properties and light weight.The formation mechanism for the non-equilibrium (W0.5Al0.5)C grains during in-situ high-pressure sintering is also discussed.

  4. Hydration of swelling clay and bacteria interaction. An experimental in situ reaction study; Hydratation des argiles gonflantes et influence des bacteries. Etude experimentale de reaction in situ

    Energy Technology Data Exchange (ETDEWEB)

    Berger, J

    2008-01-15

    This study reports on the physical-chemical behaviour of swelling di-octahedral clays (smectites) and their interaction with aqueous solutions and bacteria (Shewanella putrefaciens). Experimental results are presented for compacted clays, hydrated under confined volume conditions, using a new type of reaction-cell (the 'wet-cell' of Warr and Hoffman, 2004) that was designed for in situ X-ray diffraction (XRD) measurement. For comparison, dispersed clay systems were studied using standard batch solutions subjected to varying degrees of agitation. The combination of time-dependent in situ XRD measurements with gravimetric measurements and calculated diffraction patterns using the CALCMIX software (Plancon and Drits, 1999) allowed to successful quantification of the dynamics of water uptake and storage. This analytical procedure combined with published water vapour adsorption data enabled determination of the abundance of structured water layers, developed in the interlayer space, and the amount of water contained in different storage sites (interlayers, surfaces and pore spaces). Qualitative information on surface area and textural organization was also estimated based on calculated changes in the average particle thickness and the organization of water layer structures (ordering). Abiotic smectite hydration experiments, using a range of natural and industrial bentonites (SWy-2, IBECO, MX80, TIXOTON), focused on defining the role of the interlayer cation, variable clay packing densities and the ionic strength of the infiltrating solution. The rate of smectite hydration, as expected, was seen to be highly dependent on the type of interlayer cation (enhanced for Ca as opposed to Na) and the ionic strength of solution (enhanced uptake rates with saline solutions, particularly as they infiltrate Na-smectite). A range of dynamic changes in micro textural state occurred as a function of packing density. These changes explain the differences in hydration behaviour

  5. Nanofluidics, from bulk to interfaces.

    Science.gov (United States)

    Bocquet, Lydéric; Charlaix, Elisabeth

    2010-03-01

    Nanofluidics has emerged recently in the footsteps of microfluidics, following the quest for scale reduction inherent to nanotechnologies. By definition, nanofluidics explores transport phenomena of fluids at nanometer scales. Why is the nanometer scale specific? What fluid properties are probed at nanometric scales? In other words, why does 'nanofluidics' deserve its own brand name? In this critical review, we will explore the vast manifold of length scales emerging for fluid behavior at the nanoscale, as well as the associated mechanisms and corresponding applications. We will in particular explore the interplay between bulk and interface phenomena. The limit of validity of the continuum approaches will be discussed, as well as the numerous surface induced effects occurring at these scales, from hydrodynamic slippage to the various electro-kinetic phenomena originating from the couplings between hydrodynamics and electrostatics. An enlightening analogy between ion transport in nanochannels and transport in doped semi-conductors will be discussed (156 references).

  6. New fermions in the bulk

    CERN Document Server

    de Brito, K P S

    2016-01-01

    Spinor fields on 5-dimensional Lorentzian manifolds are classified, according to the geometric Fierz identities that involve their bilinear covariants. Based upon this classification that generalises the celebrated 4-dimensional Lounesto classification of spinor fields, new non-trivial classes of 5-dimensional spinor fields are, hence, found, with important potential applications regarding bulk fermions and their subsequent localisation on brane-worlds. In addition, quaternionic bilinear covariants are used to derive the quaternionic spin density, through the truncated exterior bundle. In order to accomplish a realisation of these new spinors, a Killing vector field is constructed on the horizon of 5-dimensional Kerr black holes. This Killing vector field is shown to reach the time-like Killing vector field at the spatial infinity, through a current 1-form density, constructed with the derived new spinor fields. The current density is, moreover, expressed as the f\\"unfbein components, assuming a condensed for...

  7. New fermions in the bulk

    Science.gov (United States)

    de Brito, K. P. S.; da Rocha, Roldão

    2016-10-01

    The spinor fields on 5-dimensional Lorentzian manifolds are classified according to the geometric Fierz identities, which involve their bilinear covariants. Based upon this classification, which generalises the celebrated 4-dimensional Lounesto classification of spinor fields, new non-trivial classes of 5-dimensional spinor fields are hence found, with important potential applications regarding bulk fermions and their subsequent localisation on brane-worlds. In addition, quaternionic bilinear covariants are used to derive the quaternionic spin density through the truncated exterior bundle. In order to accomplish the realisation of these new spinors, a Killing vector field is constructed on the horizon of a 5-dimensional Kerr black hole. This Killing vector field is shown to reach the time-like Killing vector field at spatial infinity through a current 1-form density, constructed with the new derived spinor fields. The current density is, moreover, expressed as the fünfbein component, assuming a condensed form.

  8. Melt-growth bulk superconductors and application to an axial-gap-type rotating machine

    Science.gov (United States)

    Zhang, Yufeng; Zhou, Difan; Ida, Tetsuya; Miki, Motohiro; Izumi, Mitsuru

    2016-04-01

    The present manuscript addresses key issues in the course of our study of materials processing of bulk high-temperature superconductors, trapped flux and its application to a prototype axial-gap-type rotating machine. The TUMSAT group has conducted a series of studies since 2003 on the growth of GdBa2Cu3O7-δ bulk material and its application in a compact low-speed high-torque rotating machine. In the stage of material growth, gaining the advantage of a large motive torque density requires large integrated flux in the motor/generators. A large grain surface might be required with sophisticated techniques for the melt-growth texture in the bulk with optimal flux pinning. In the second stage, the in situ magnetization procedure for bulk superconductors in the applied machine is a crucial part of the technology. Pulsed current excitation by using an armature copper winding has magnetized field pole bulks on the rotor. The axial-gap flux synchronous machine studied in the past decade is a condensed technology and indicates that further scientific development is required for a future compact machine to be superior to conventional ones in accordance with the cryogenic periphery and flux stabilization.

  9. Modeling deformation behavior of Cu-Zr-Al bulk metallic glass matrix composites

    Science.gov (United States)

    Pauly, S.; Liu, G.; Wang, G.; Das, J.; Kim, K. B.; Kühn, U.; Kim, D. H.; Eckert, J.

    2009-09-01

    In the present work we prepared an in situ Cu47.5Zr47.5Al5 bulk metallic glass matrix composite derived from the shape memory alloy CuZr. We use a strength model, which considers percolation and a three-microstructural-element body approach, to understand the effect of the crystalline phase on the yield stress and the fracture strain under compressive loading, respectively. The intrinsic work-hardenability due to the martensitic transformation of the crystalline phase causes significant work hardening also of the composite material.

  10. Next-Generation Catalysis for Renewables: Combining Enzymatic with Inorganic Heterogeneous Catalysis for Bulk Chemical Production

    DEFF Research Database (Denmark)

    Vennestrøm, Peter Nicolai Ravnborg; Christensen, C.H.; Pedersen, S.

    2010-01-01

    chemical platform under different conditions than those conventionally employed. Indeed, new process and catalyst concepts need to be established. Both enzymatic catalysis (biocatalysis) and heterogeneous inorganic catalysis are likely to play a major role and, potentially, be combined. One type...... of combination involves one-pot cascade catalysis with active sites from bio- and inorganic catalysts. In this article the emphasis is placed specifically on oxidase systems involving the coproduction of hydrogen peroxide, which can be used to create new in situ collaborative oxidation reactions for bulk...

  11. Solvent additive effects on small molecule crystallization in bulk heterojunction solar cells probed during spin casting

    KAUST Repository

    Pérez, Louis A.

    2013-09-04

    Solvent additive processing can lead to drastic improvements in the power conversion efficiency (PCE) in solution processable small molecule (SPSM) bulk heterojunction solar cells. In situ grazing incidence wide-angle X-ray scattering is used to investigate the kinetics of crystallite formation during and shortly after spin casting. The additive is shown to have a complex effect on structural evolution invoking polymorphism and enhanced crystalline quality of the donor SPSM. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. In situ measurements and model estimates of NO3 and NH4 uptake by different phytoplankton size fractions in the southern Benguela upwelling system.

    Directory of Open Access Journals (Sweden)

    Josephine Ffion Atkins

    2016-10-01

    Full Text Available Bulk measurements can be made of phytoplankton standing stocks on a quasi-synoptic scale but it is more difficult to measure rates of production and nutrient uptake. We present a method to estimate nitrogen uptake rates in productive coastal environments. We use observed phytoplankton cell size distributions and ambient nitrogen concentrations to calculate uptake rates of nitrate, ammonium and total nitrogen by different size fractions of diverse phytoplankton communities in a coastal upwelling system. The data are disaggregated into size categories, uptake rates are calculated and these uptake rates are reaggregated to obtain bulk estimates. The calculations are applied to 72 natural assemblages for which nitrogen uptake rates and particle size distributions were measured textit in situ . The calculated values of total N uptake integrated across all size classes are similar to those of textit in situ bulk measurements (N slope=0.90, (NH _ 4 slope=0.96 indicating dependence of NH _ 4 and total N uptake on ambient N concentrations and cell size distributions of the phytoplankton assemblages. NO _ 3 uptake was less well explained by cell size and ambient concentrations, but regressions between measured and estimated rates were still significant. The results suggest that net nitrogen dynamics can be quantified at an assemblage scale using size dependencies of Michaelis-Menten uptake parameters. These methods can be applied to particle size distributions that have been routinely measured in eutrophic systems to estimate and subsequently analyse variability in nitrogen uptake.

  13. In Situ Trace Element Measurements on Roda and the Origin of Diogenites

    Science.gov (United States)

    Mittlefehldt, David W.; Herrin, J. S.

    2011-01-01

    The origin of diogenites remains poorly understood. A recent model interprets many diogenites to have been formed from melts that were derived by remelting initial magma ocean cumulates, and these penultimate parent melts were then contaminated by melts derived from remelting of the basaltic (eucritic) crust to form the ultimate diogenite parent melts [1] (hereafter the remelting model). This is a very complicated petrogenesis that has profound implications for the geological evolution of 4 Vesta if correct. This model was developed based on trace element analyses of bulk rock samples that had been leached in acids to remove phosphates; the compositions of the residues were interpreted to be close to those of cumulus orthopyroxenes plagioclase, chromite and olivine [1]. In situ measurements of phases in diogenites can be used to test this model. We have begun a campaign of laser ablation ICP-MS of orthopyroxene grains in diogenites for this purpose. Here we report our first results on one diogenite, Roda. We have determined a suite of trace lithophile elements on nine, mm-sized pyroxene grains separated from Roda that have previously been studied [2, 3]. A key observation supporting the remelting model is the very low Eu/Eu* of leached residues; values too low to represent orthopyroxene that crystallized from melts with chondritic Sm/Eu and Gd/Eu [1]. (Eu* = Eu interpolated from REE diagrams.) Crustal remelts have low Sm/Eu and Gd/Eu, and orthopyroxenes that crystallized from parent melts contaminated by them would have very low Eu/Eu* [1]. Roda grains have Eu/Eu* of 0.243 to 0.026; the latter a value lower than any measured on bulk diogenite leached residues (0.041) [1]. There is a general negative correlation between Eu/Eu* and some incompatible elements (Zr, Nb, Hf), but not others (LREE). This appears inconsistent with the remelting model as it would suggest an evolving parent melt with La de-creasing as Zr increased and Eu/Eu* decreased. Grain R-15 includes

  14. Diurnal variability in riverine dissolved organic matter composition determined by in situ optical measurement in the San Joaquin River (California, USA)

    Science.gov (United States)

    Spencer, R.G.M.; Pellerin, B.A.; Bergamaschi, B.A.; Downing, B.D.; Kraus, T.E.C.; Smart, D.R.; Dahlgren, R.A.; Hernes, P.J.

    2007-01-01

    Dissolved organic matter (DOM) concentration and composition in riverine and stream systems are known to vary with hydrological and productivity cycles over the annual and interannual time scales. Rivers are commonly perceived as homogeneous with respect to DOM concentration and composition, particularly under steady flow conditions over short time periods. However, few studies have evaluated the impact of short term variability (<1 day) on DOM dynamics. This study examined whether diurnal processes measurably altered DOM concentration and composition in the hypereutrophic San Joaquin River (California) during a relatively quiescent period. We evaluated the efficacy of using optical in situ measurements to reveal changes in DOM which may not be evident from bulk dissolved organic carbon (DOC) measurement alone. The in situ optical measurements described in this study clearly showed for the first time diurnal variations in DOM measurements, which have previously been related to both composition and concentration, even though diurnal changes were not well reflected in bulk DOC concentrations. An apparent asynchronous trend of DOM absorbance and chlorophyll-a in comparison to chromophoric dissolved organic matter (CDOM) fluorescence and spectral slope S290-350 suggests that no one specific CDOM spectrophotometric measurement explains absolutely DOM diurnal variation in this system; the measurement of multiple optical parameters is therefore recommended. The observed diurnal changes in DOM composition, measured by in situ optical instrumentation likely reflect both photochemical and biologically-mediated processes. The results of this study highlight that short-term variability in DOM composition may complicate trends for studies aiming to distinguish different DOM sources in riverine systems and emphasizes the importance of sampling specific study sites to be compared at the same time of day. The utilization of in situ optical technology allows short-term variability

  15. In situ epitaxial MgB2 thin films for superconducting electronics.

    Science.gov (United States)

    Zeng, Xianghui; Pogrebnyakov, Alexej V; Kotcharov, Armen; Jones, James E; Xi, X X; Lysczek, Eric M; Redwing, Joan M; Xu, Shengyong; Li, Qi; Lettieri, James; Schlom, Darrell G; Tian, Wei; Pan, Xiaoqing; Liu, Zi-Kui

    2002-09-01

    The newly discovered 39-K superconductor MgB2 holds great promise for superconducting electronics. Like the conventional superconductor Nb, MgB2 is a phonon-mediated superconductor, with a relatively long coherence length. These properties make the prospect of fabricating reproducible uniform Josephson junctions, the fundamental element of superconducting circuits, much more favourable for MgB2 than for high-temperature superconductors. The higher transition temperature and larger energy gap of MgB2 promise higher operating temperatures and potentially higher speeds than Nb-based integrated circuits. However, success in MgB2 Josephson junctions has been limited because of the lack of an adequate thin-film technology. Because a superconducting integrated circuit uses a multilayer of superconducting, insulating and resistive films, an in situ process in which MgB2 is formed directly on the substrate is desirable. Here we show that this can be achieved by hybrid physical-chemical vapour deposition. The epitaxially grown MgB2 films show a high transition temperature and low resistivity, comparable to the best bulk samples, and their surfaces are smooth. This advance removes a major barrier for superconducting electronics using MgB2.

  16. Exploring electrosorption at iron electrode with in situ surface-enhanced infrared absorption spectroscopy.

    Science.gov (United States)

    Huo, Sheng-Juan; Wang, Jin-Yi; Yao, Jian-Lin; Cai, Wen-Bin

    2010-06-15

    Surface-enhanced infrared absorption spectroscopy (SEIRAS) in attenuated total reflection (ATR) configuration has been extended to the Fe electrode/electrolyte interface in neutral and weakly acidic solutions for the first time. The SEIRA-active Fe film electrode was obtained through a potentiostatic electrodeposition of a virtually pinhole-free 40 nm-thick Fe overfilm onto a 60 nm-thick Au underfilm chemically predeposited on the reflecting plane of an ATR Si prism. The infrared absorption for CO adlayer at the Fe film electrode measured with ATR-SEIRAS was enhanced by a factor of larger than 34, as compared to that at a Fe bulk electrode with external infrared absorption spectroscopy in the literature. More importantly, the unipolar band shape enabled the reliable determination of the Stark tuning rates of CO adlayer at Fe electrode. In situ ATR-SEIRAS was also applied to study the electrosorption of a typical corrosion inhibitor benzotriazole (BTAH) on Fe electrode as a function of potential, providing additional spectral information at positive potentials in support of the formation of a polymer-like surface complex Fe(II)(m)(BTA)(n) as the corrosion-resistant layer.

  17. In situ observations of shape evolution during copper dissolution using atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Cruickshank, B.J.; Gewirth, A.A.; Rynders, R.M.; Alkire, R.C. (Illinois Univ., Urbana, IL (United States). Materials Research Lab.)

    1992-10-01

    In this paper, atomic force microscopy is used to monitor, in situ, the shape evolution of polycrystalline copper during anodic dissolution in 0. 5 M H[sub 2]SO[sub 4]. During dissolution of the copper surface under a small anodic potential (30 mV), an overlayer of material that resulted from mechanical polishing was removed, exposing the underlying grain boundaries. A chemically etched sample was exposed to the same experimental conditions, and no overlayer was observed. Dissolution of the copper bulk metal was monitored under a higher applied potential (100 mV, 0. 5M H[sub 2]SO[sub 4]). The overlayer was immediately removed, and the dissolution produced a nonuniform, crystallographically etched surface. The inhibiting effect of benzotriazole (BTA) on copper dissolution in 0. 5M H[sub 2]SO[sub 4]/20 mM BTA was observed. Copper dissolution did not proceed at 100 mV or 200 mV applied potential; but at 300 mV, rapid localized dissolution resulted in the formation of pit-like features.

  18. Detection of Helicobacter pylori in raw bovine milk by fluorescence in situ hybridization (FISH).

    Science.gov (United States)

    Angelidis, Apostolos S; Tirodimos, Ilias; Bobos, Mattheos; Kalamaki, Mary S; Papageorgiou, Demetrios K; Arvanitidou, Malamatenia

    2011-12-02

    The transmission pathways of Helicobacter pylori in humans have not been fully elucidated. Research in the last decade has proposed that foodborne transmission, among others, may be a plausible route of human infection. Owing to the organism's fastidious growth characteristics and its ability to convert to viable, yet unculturable states upon exposure to stress conditions, the detection of H. pylori in foods via culture-dependent methods has been proven to be laborious, difficult and in most cases unsuccessful. Hence, nucleic acid-based methods have been proposed as alternative methods but, to date, only PCR-based methods have been reported in the literature. In the current study, fluorescence in situ hybridization (FISH) was used for the detection of H. pylori in raw, bulk-tank bovine milk. After repeated milk centrifugation and washing steps, the bacterial flora of raw milk was subjected to fixation and permeabilization and H. pylori detection was conducted by FISH after hybridization with an H. pylori-specific 16S rRNA-directed fluorescent oligonucleotide probe. Using this protocol, H. pylori was detected in four out of the twenty (20%) raw milk samples examined. The data presented in this manuscript indicate that FISH can serve as an alternative molecular method for screening raw bovine milk for the presence of H. pylori.

  19. In situ tensile testing of individual Co nanowires inside a scanning electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Dongfeng; Breguet, Jean-Marc; Clavel, Reymond [Laboratory of Robotic Systems, Ecole Polytechnique Federale de Lausanne (EPFL), Station 9, CH-1015 Lausanne (Switzerland); Phillippe, Laetitia; Utke, Ivo; Michler, Johann [Mechanics of Materials and Nanostructures Laboratory, EMPA-Materials Science and Technology, Feuerwerkstrasse 39, CH-3602 Thun (Switzerland)

    2009-09-09

    Uniaxial quasi-static tensile testing on individual nanocrystalline Co nanowires (NWs), synthesized by electrochemical deposition process (EDP) in porous templates, was performed inside a scanning electron microscope (SEM) using a microfabricated tensile stage consisting of a comb drive actuator and a clamped-clamped beam force sensor. A 'three-beam structure' was fabricated by focused ion beam induced deposition (FIBID) on the stage, from which the specimen elongation and the tensile force could be measured simultaneously from SEM images at high magnification. A novel strategy of modifying device topography, e.g. in the form of trenches and pillars, was proposed to facilitate in situ SEM pick-and-place nanomanipulation, which could achieve a high yield of about 80% and reduce the difficulties in specimen preparation for tensile testing at the nanoscale. The measured apparent Young's modulus (75.3 {+-} 14.6) GPa and tensile strength (1.6 {+-} 0.4) GPa are significantly lower than the bulk modulus and the theoretical strength of monocrystalline samples, respectively. This result is important for designing Co NW-based devices. The origins of these distinctions are discussed in terms of the stiffnesses of the soldering portions, specimen misalignment, microstructure of the NWs and the experimental measurement uncertainty.

  20. Titanium boride equation of state determined by in-situ X-ray diffraction

    Directory of Open Access Journals (Sweden)

    Shigeaki Ono

    2016-12-01

    Full Text Available The equation of state (EOS of titanium boride, TiB2, was investigated by in situ X-ray diffraction in a diamond anvil cell and multianvil high-pressure apparatus. The pressure-volume-temperature (P-V-T data were collected at up to 111 GPa and room temperature for the diamond-anvil cell experiments and at up to 15 GPa and 1300 K for the multianvil experiments. No phase transition was observed through the entire range of experimental conditions. The pressure-volume data at room temperature were fitted using a Vinet EOS to obtain the isothermal bulk modulus, BT0 = 256.7 GPa, and its pressure derivative, B’T0 = 3.83. When fitting a thermal EOS using the P-V-T data for the multianvil experiments, we find that (∂BT/∂TV = 0.095 (GPa/K and α0 = 2.49 × 10−5 K−1.

  1. In situ observation of graphene sublimation and multi-layer edge reconstructions.

    Science.gov (United States)

    Huang, Jian Yu; Ding, Feng; Yakobson, Boris I; Lu, Ping; Qi, Liang; Li, Ju

    2009-06-23

    We induced sublimation of suspended few-layer graphene by in situ Joule-heating inside a transmission electron microscope. The graphene sublimation fronts consisted of mostly {1100} zigzag edges. Under appropriate conditions, a fractal-like "coastline" morphology was observed. Extensive multiple-layer reconstructions at the graphene edges led to the formation of unique carbon nanostructures, such as sp(2)-bonded bilayer edges (BLEs) and nanotubes connected to BLEs. Flat fullerenes/nanopods and nanotubes tunneling multiple layers of graphene sheets were also observed. Remarkably, >99% of the graphene edges observed during sublimation are BLEs rather than monolayer edges (MLEs), indicating that BLEs are the stable edges in graphene at high temperatures. We reproduced the "coastline" sublimation morphologies by kinetic Monte Carlo (kMC) simulations. The simulation revealed geometrical and topological features unique to quasi-2-dimensional (2D) graphene sublimation and reconstructions. These reconstructions were enabled by bending, which cannot occur in first-order phase transformations of 3D bulk materials. These results indicate that substrate of multiple-layer graphene can offer unique opportunities for tailoring carbon-based nanostructures and engineering novel nano-devices with complex topologies.

  2. A dispenser-reactor apparatus applied for in situ XAS monitoring of Pt nanoparticle formation.

    Science.gov (United States)

    Boita, Jocenir; Castegnaro, Marcus Vinicius; Alves, Maria do Carmo Martins; Morais, Jonder

    2015-05-01

    In situ time-resolved X-ray absorption spectroscopy (XAS) measurements collected at the Pt L3-edge during the synthesis of Pt nanoparticles (NPs) in aqueous solution are reported. A specially designed dispenser-reactor apparatus allowed for monitoring changes in the XAS spectra from the earliest moments of Pt ions in solution until the formation of metallic nanoparticles with a mean diameter of 4.9 ± 1.1 nm. By monitoring the changes in the local chemical environment of the Pt atoms in real time, it was possible to observe that the NPs formation kinetics involved two stages: a reduction-nucleation burst followed by a slow growth and stabilization of NPs. Subsequently, the synthesized Pt NPs were supported on activated carbon and characterized by synchrotron-radiation-excited X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS). The supported Pt NPs remained in the metallic chemical state and with a reduced size, presenting slight lattice parameter contraction in comparison with the bulk Pt values.

  3. Densification of in situ prepared mesocarbon microbead/carbon nanotube composites by hot-press sintering

    Institute of Scientific and Technical Information of China (English)

    WU Bin; GONG Qian-ming; WU Jian-jun; SONG Huai-he; LIANG Ji

    2009-01-01

    In situ prepared mesocarbon microbead/carbon nanotube(MCMB/CNT) composites are potential precursors of high density carbon materials for various applications. Integrated MCMB/CNT composites were successfully fabricated by hot-press sintering at 550 ℃ under 30 MPa. After further calcination at 900 ℃, the hot-press sintering fabricated MCMB block has an apparent density of 1.77 g/cm3 and the open porosity 5.1%. With the addition of 5%(mass fraction) CNTs, the density of the composite block is elevated to 1.84 g/cm3, and its open porosity is reduced to 3.5%. The flexural strength of composite block with 5% CNTs is elevated to 116 MPa. Through the hot-press sintering, pores of 10-50 nm in the calcinated bulks are remarkably eliminated. The interstice between microbeads in the composite blocks is filled up by CNTs together with β-resin and quinoline-insoluble spheres, which can further contribute to the densification.

  4. Surface scattering and giant magnetoresistance: In-situ resistance and magnetoresistance experiments

    Science.gov (United States)

    Bailey, William Evans

    Surface scattering, particularly the enhancement of "specular" scattering, is widely believed to hold the key to yet-unattained levels of spin-valve GMR. We have developed a novel technique to measure surface scattering, the in-situ magnetoconductance measurement. By measuring resistance and GMR in real time during deposition, in ultrahigh vacuum, and in the Van der Pauw configuration, we may determine the effect on scattering of various overlayers as they are created. We have applied this technique to study claims that the specularity may be modified through deposition of metal overlayers. In conjunction with first-principles based calculations of film conductance and detailed characterization of thickness-dependent film microstructure, we have determined that the surface specularity is not modified during overlayer deposition. Effects previously attributed to specularity modulations are well interpreted through scattering mechanisms intrinsic to the system. We have also examined the dependence of GMR on bulk microstructure, as characterized ex-situ. We find that crystallographic disorder tends to decrease spin-valve GMR. This is shown experimentally through depositions of several series of samples, characterization of the relevant defects, and correlation to magnetotransport measurements. We have formed the films by sputtering and UHV ion beam deposition. Experimental techniques used to characterize microstructure are high-resolution cross-sectional transmission electron microscopy (HR-xTEM), x-ray diffraction (XRD), 59Co nuclear magnetic resonance (NMR), contributed by Ewa Jedryka at the Polish Institute of Physics in Warsaw.

  5. Monolayers of poly(amido amine) dendrimers on mica - In situ streaming potential measurements.

    Science.gov (United States)

    Michna, Aneta; Adamczyk, Zbigniew; Sofińska, Kamila; Matusik, Katarzyna

    2017-01-01

    The deposition of poly(amido amine) dendrimers on mica at various pHs was studied by the atomic force microscopy (AFM) and in situ streaming potential measurements. Bulk characteristics of dendrimers were acquired by using the dynamic light scattering (DLS) and the laser Doppler velocimetry (LDV). The hydrodynamic radius derived from DLS measurements was 5.2nm for the ionic strength of 10(-2)M and pH range 4-10. The electrophoretic mobility, the zeta potential and the number of electrokinetic charges per molecule were derived as a function of pH from the LDV measurements. It was revealed that the dendrimers are positively charged for pH up to 10. This promoted their deposition on negatively charged mica substrate whose kinetics was quantitatively evaluated by direct AFM imaging and streaming potential measurements interpreted in terms of the electrokinetic model. The desorption kinetics of dendrimers under flowing conditions from monolayers of various coverage was also studied. It was revealed that dendrimer deposition was partially reversible for pH above 5.8. The acid-base properties of the dendrimer monolayers deposited on mica were characterized.

  6. In situ KPFM imaging of local photovoltaic characteristics of structured organic photovoltaic devices.

    Science.gov (United States)

    Watanabe, Satoshi; Fukuchi, Yasumasa; Fukasawa, Masako; Sassa, Takafumi; Kimoto, Atsushi; Tajima, Yusuke; Uchiyama, Masanobu; Yamashita, Takashi; Matsumoto, Mutsuyoshi; Aoyama, Tetsuya

    2014-02-12

    Here, we discuss the local photovoltaic characteristics of a structured bulk heterojunction, organic photovoltaic devices fabricated with a liquid carbazole, and a fullerene derivative based on analysis by scanning kelvin probe force microscopy (KPFM). Periodic photopolymerization induced by an interference pattern from two laser beams formed surface relief gratings (SRG) in the structured films. The surface potential distribution in the SRGs indicates the formation of donor and acceptor spatial distribution. Under illumination, the surface potential reversibly changed because of the generation of fullerene anions and hole transport from the films to substrates, which indicates that we successfully imaged the local photovoltaic characteristics of the structured photovoltaic devices. Using atomic force microscopy, we confirmed the formation of the SRG because of the material migration to the photopolymerized region of the films, which was induced by light exposure through photomasks. The structuring technique allows for the direct fabrication and the control of donor and acceptor spatial distribution in organic photonic and electronic devices with minimized material consumption. This in situ KPFM technique is indispensable to the fabrication of nanoscale electron donor and electron acceptor spatial distribution in the devices.

  7. In situ respiration measurements of megafauna in the Kermadec Trench

    Science.gov (United States)

    Nunnally, Clifton C.; Friedman, Jason R.; Drazen, Jeffrey C.

    2016-12-01

    The aim of this paper is to measure metabolic rates of megafauna living in depths greater than 6000 m. Echinoderms, actinarians and a polychaete were captured by remotely operated vehicle (ROV) and inserted into respiration chambers in situ at depths of 4049 m, 7140 m and 8074 m in the region of the Kermadec Trench SW Pacific Ocean. Hadal research has moved into a new frontier as technological improvements now allow for a meticulous investigation of trench ecology in depths greater than 6000 m. The development of an in situ respirometer for use in these studies was deployed in the Kermadec Trench to obtain the first ever rates of basal metabolic rates of hadal megafauna. Typical deep-sea experiments of individual animal physiology must deal with covarying factors of pressure, temperature, light and food supply in this study investigated the effects of pressure and increased food supply on overall animal metabolism. In the Kermadec Trench, holothurian respiration rates (n=4), 0.079±0.011 (mean±SE) μmol-O2 g-1 h-1, were higher than those captured at abyssal depths (n=2), 0.018±0.002 μmol-O2 g-1h-1, in the same region (p<0.001). When Q10 adjusted to a common temperature of 2.5 °C trench holothurian respiration rates ranged between 0.068 and 0.119 μmol-O2 g-1 h-1. Anemone respiration rates were remarkably similar between abyssal and hadal specimens, 0.110 and 0.111 μmol-O2 g-1 h-1, respectively. Our results on echinoderm respiration when corrected for temperature and mass fall below the slope regression when compared with other in situ measurements at shallower ocean depths.

  8. Characterization of alginate-brushite in-situ hydrogel composites

    Energy Technology Data Exchange (ETDEWEB)

    Dabiri, Seyed Mohammad Hossein [Department of Informatics, Bioengineering, Robotics, and System Engineering, University of Genoa, Genoa (Italy); Lagazzo, Alberto; Barberis, Fabrizio [Department of Civil, Chemical and Environmental Engineering, University of Genoa, Genoa (Italy); Farokhi, Mehdi [National Cell Bank of Iran, Pasteur Institute of Iran, Tehran (Iran, Islamic Republic of); Finochio, Elisabetta [Department of Civil, Chemical and Environmental Engineering, University of Genoa, Genoa (Italy); Pastorino, Laura [Department of Informatics, Bioengineering, Robotics, and System Engineering, University of Genoa, Genoa (Italy)

    2016-10-01

    In the present study alginate-brushite composite hydrogels were in-situ synthetized and characterized with respect to preparation parameters. Specifically, the influence of initial pH value and initial concentration of phosphate precursor on the in-situ fabrication of the composite hydrogel were taken into account. The composite hydrogels were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric (TGA, DTG) and differential thermal analysis (DTA). Finally, the cell viability tests were carried out (MTT) over the incubation time period of 3, 7, and 14 days. The results revealed that the formation and the crystalline stability of brushite were highly dependent on the initial pH value. It was shown that as the pH reached to the value of 6, characteristics peaks of brushite appeared in the FTIR spectra. Besides, the XRD and thermal analysis results were in a good accordance with those of FTIR. In addition, the SEM images demonstrated that the plate like brushite was formed inside the alginate matrix. Also, a considerable impact of pH variation on the biocompatibility of samples was noticed so that the majority of samples especially those prepared in the acidic conditions were toxic. - Highlights: • Alginate-brushite hydrogel composites were obtained through an in-situ process • The brushite crystals started forming at pH value of 6 • The increase in the initial concentration of phosphate precursor resulted in more crystalline structure • Samples prepared at pH value of 8 had the most stable crystalline structure • Brushite crystals promoted the biocompatibility of alginate.

  9. Assessing in situ rates of anaerobic hydrocarbon bioremediation.

    Science.gov (United States)

    Gieg, Lisa M; Alumbaugh, Robert E; Field, Jennifer; Jones, Jesse; Istok, Jonathon D; Suflita, Joseph M

    2009-03-01

    Identifying metabolites associated with anaerobic hydrocarbon biodegradation is a reliable way to garner evidence for the intrinsic bioremediation of problem contaminants. While such metabolites have been detected at numerous sites, the in situ rates of anaerobic hydrocarbon decay remain largely unknown. Yet, realistic rate information is critical for predicting how long individual contaminants will persist and remain environmental threats. Here, single-well push-pull tests were conducted at two fuel-contaminated aquifers to determine the in situ biotransformation rates of a suite of hydrocarbons added as deuterated surrogates, including toluene-d(8), o-xylene-d(10), m-xylene-d(10), ethylbenzene-d(5) (or -d(10)), 1, 2, 4-trimethylbenzene-d(12), 1, 3, 5-trimethylbenzene-d(12), methylcyclohexane-d(14) and n-hexane-d(14). The formation of deuterated fumarate addition and downstream metabolites was quantified and found to be somewhat variable among wells in each aquifer, but generally within an order of magnitude. Deuterated metabolites formed in one aquifer at rates that ranged from 3 to 50 µg l(-1) day(-1), while the comparable rates at another aquifer were slower and ranged from 0.03 to 15 µg l(-1) day(-1). An important observation was that the deuterated hydrocarbon surrogates were metabolized in situ within hours or days at both sites, in contrast to many laboratory findings suggesting that long lag periods of weeks to months before the onset of anaerobic biodegradation are typical. It seems clear that highly reduced conditions are not detrimental to the intrinsic bioremediation of fuel-contaminated aquifers.

  10. In Situ Electron Microscopy of Lactomicroselenium Particles in Probiotic Bacteria

    Directory of Open Access Journals (Sweden)

    Gabor Nagy

    2016-06-01

    Full Text Available Electron microscopy was used to test whether or not (a in statu nascendi synthesized, and in situ measured, nanoparticle size does not differ significantly from the size of nanoparticles after their purification; and (b the generation of selenium is detrimental to the bacterial strains that produce them. Elemental nano-sized selenium produced by probiotic latic acid bacteria was used as a lactomicroselenium (lactomicroSel inhibitor of cell growth in the presence of lactomicroSel, and was followed by time-lapse microscopy. The size of lactomicroSel produced by probiotic bacteria was measured in situ and after isolation and purification. For these measurements the TESLA BS 540 transmission electron microscope was converted from analog (aTEM to digital processing (dTEM, and further to remote-access internet electron microscopy (iTEM. Lactobacillus acidophilus produced fewer, but larger, lactomicroSel nanoparticles (200–350 nm than Lactobacillus casei (L. casei, which generated many, smaller lactomicroSel particles (85–200 nm and grains as a cloudy, less electrodense material. Streptococcus thermophilus cells generated selenoparticles (60–280 nm in a suicidic manner. The size determined in situ in lactic acid bacteria was significantly lower than those measured by scanning electron microscopy after the isolation of lactomicroSel particles obtained from lactobacilli (100–500 nm, but higher relative to those isolated from Streptococcus thermopilus (50–100 nm. These differences indicate that smaller lactomicroSel particles could be more toxic to the producing bacteria themselves and discrepancies in size could have implications with respect to the applications of selenium nanoparticles as prebiotics.

  11. In situ oxygen dynamics in coral-algal interactions.

    Directory of Open Access Journals (Sweden)

    Daniel Wangpraseurt

    Full Text Available BACKGROUND: Coral reefs degrade globally at an alarming rate, with benthic algae often replacing corals. However, the extent to which benthic algae contribute to coral mortality, and the potential mechanisms involved, remain disputed. Recent laboratory studies suggested that algae kill corals by inducing hypoxia on the coral surface, through stimulated microbial respiration. METHODS/FINDINGS: We examined the main premise of this hypothesis by measuring in situ oxygen microenvironments at the contact interface between the massive coral Porites spp. and turf algae, and between Porites spp. and crustose coralline algae (CCA. Oxygen levels at the interface were similar to healthy coral tissue and ranged between 300-400 µM during the day. At night, the interface was hypoxic (~70 µM in coral-turf interactions and close to anoxic (~2 µM in coral-CCA interactions, but these values were not significantly different from healthy tissue. The diffusive boundary layer (DBL was about three times thicker at the interface than above healthy tissue, due to a depression in the local topography. A numerical model, developed to analyze the oxygen profiles above the irregular interface, revealed strongly reduced net photosynthesis and dark respiration rates at the coral-algal interface compared to unaffected tissue during the day and at night, respectively. CONCLUSIONS/SIGNIFICANCE: Our results showed that hypoxia was not a consistent feature in the microenvironment of the coral-algal interface under in situ conditions. Therefore, hypoxia alone is unlikely to be the cause of coral mortality. Due to the modified topography, the interaction zone is distinguished by a thicker diffusive boundary layer, which limits the local metabolic activity and likely promotes accumulation of potentially harmful metabolic products (e.g., allelochemicals and protons. Our study highlights the importance of mass transfer phenomena and the need for direct in situ measurements of

  12. Reinforced cementitous composite with in situ shrinking microfibers

    Science.gov (United States)

    Kim, Eric S.; Lee, Jason K.; Lee, Patrick C.; Huston, Dryver R.; Tan, Ting; Al-Ghamdi, Saleh

    2017-03-01

    This paper describes an innovative fiber reinforcement technology for cementitious composite structures that employs in situ shrinking microfibers to provide supplemental strength-enhancing compressive stresses. Reinforced concrete is one of the most commonly used structural materials in construction industry, primarily due to its cost, durability, ability to be easily fabricated into a variety of shapes on site, and locally abundant raw material availability almost everywhere. Unlike incumbent passive reinforcing microfiber technology, in situ shrinking microfibers that respond to an in situ stimulus such as heat, pH, or moisture variations can induce pre-compression to matrix and create additional resistance from external loads, creating stronger composite structures. In this paper, heat-activated-shrinking (HAS) microfibers made from polyolefin, and pH-activated-shrinking (pHAS) microfibers made from chitosan powder were used to study effects of shrinking microfiber reinforcing in concrete. Shrinking ratios and tensile strengths of both microfibers were measured. Cementitious specimens with active shrinking microfibers, passive non shrinking fibers, as well as control samples were made. Mechanical properties of the samples were compared with compression and three-point bending tests. The optimum microfiber weight percentages for HAS microfibers were 0.5 wt% in compression tests, and 1.0 wt% in three-point bending tests. For pHAS microfibers, the optimum weight percentages were 0.5 wt% in three-point bending tests. Compared to heat passive microfibers specimens, 45% increase in the maximum compression strengths, and 124% increase in the maximum bending strengths were achieved at the optimum weight percentages of HAS microfibers. In addition, with 0.5 wt% of pHAS microfibers, 145% increase in the maximum bending strengths of three-point bending tests resulted compared to pH passive microfibers specimens.

  13. In situ electrical transport measurement of superconductive ultrathin films

    Institute of Scientific and Technical Information of China (English)

    刘灿华; 贾金锋

    2015-01-01

    The discovery of an extraordinarily superconductive large energy gap in SrTiO3 supported single-layer FeSe films has recently initiated a great deal of research interests in surface-enhanced superconductivity and superconductive ultrathin films fabricated on crystal surfaces. On account of the instability of ultra-thin films in air, it is desirable to perform elec-trical transport measurement in ultra-high vaccum (UHV). Here we review the experimental techniques of in situ electrical transport measurement and their applications on superconductive ultrathin films.

  14. In situ Transmission Electron Microscopy of catalyst sintering

    DEFF Research Database (Denmark)

    DeLaRiva, Andrew T.; Hansen, Thomas Willum; Challa, Sivakumar R.

    2013-01-01

    Recent advancements in the field of electron microscopy, such as aberration correctors, have now been integrated into Environmental Transmission Electron Microscopes (TEMs), making it possible to study the behavior of supported metal catalysts under operating conditions at atomic resolution. Here......, we focus on in situ electron microscopy studies of catalysts that shed light on the mechanistic aspects of catalyst sintering. Catalyst sintering is an important mechanism for activity loss, especially for catalysts that operate at elevated temperatures. Literature from the past decade is reviewed...

  15. In-situ TEM characterization of nanomaterials and devices

    KAUST Repository

    Kim, Moon

    2011-10-01

    Electrical properties of nano size devices were directly measured by TEM. Real time observation of phase transition behavior in PRAM revealed that the volume of the crystalline phase is the main factor in determining cell resistance. In the transistor device, we have identified the doping type and area by measuring the I-V curve at the individual nano contact on the specimen. The evolution of the graphene edge structure was controlled and monitored at and up to 1200°C in-situ. © 2011 IEEE.

  16. Bilateral Simultaneous Rhegmatogenous Retinal Detachment following Laser in situ Keratomileusis

    Directory of Open Access Journals (Sweden)

    Erhan Yumusak

    2016-06-01

    Full Text Available A 21-year-old woman developed simultaneous rhegmatogenous retinal detachment after laser in situ keratomileusis (LASIK in both eyes. She underwent pars plana vitrectomy surgery combined with endolaser photocoagulation and silicone oil tamponade in the right eye. A week later, pneumatic retinopexy was done in the left eye. As the retinal tear did not seal, 360° scleral buckling surgery was performed and retina was attached. Bilateral simultaneous rhegmatogenous retinal detachment after LASIK for correction of myopia can be a serious complication. Patients should be informed about the possibility of this complication.

  17. In situ generation and detection of methyl radical by voltammetry

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In persulfate-acetate, dimethyl sulfoxide or tert-butyl alcohol systems, in situ generation and detection of methyl free radical are realized with voltammetry. It includes the following successive processes. The persulfate S2O82- is polarographically reduced via one-electron addition to sulfate radical SO4-., the SO4-. Initiates chain reaction with acetate, dimethyl sulfoxide, or tert-butyl alcohol on the electrode surface to produce a methyl radical, and one-electron reduction of the methyl radical yields its polarographic reduction wave. In comparison with the known techniques such as ultraviolet radiolysis coupling with electron spin resonance, etc., the proposed method is simple, sensitive and selective.

  18. Photovoltaics Using In Situ Resource Utilization for HEDS

    Science.gov (United States)

    Criswell, David R.; Curreri, Peter A.

    1998-01-01

    One of the most important elements of a human planetary base is power production. Lunar data make it clear that several types of solar-to-electric converters can be manufactured on the Moon. Materials research and processing demonstrations are suggested that can be carried out on Earth, the Space Transportation System (STS), the International Space Station (ISS), and on the Moon to advance the in situ production of solar-to-electric power systems on the Moon. Many of the technologies will be applicable to Mars, the silicate moons, and asteroids.

  19. Oxygen-free in situ scanning tunnelling microscopy

    DEFF Research Database (Denmark)

    Zhang, Jingdong; Ulstrup, Jens

    2007-01-01

    Scanning tunneling microscopy under full electrochemical potential control (in situ STM) has been used extensively as an efficient method to characterize microstructures at solid/liquid interfaces at the atomic and molecular levels. However, under ambient conditions oxygen may interfere in open......, the STM image quality of the monolayer structures has improved significantly in the absence of oxygen. Reasons for the drastic effects of dioxygen based on both chemical surface reactivity and electron scattering effects are discussed. These observations are important in general for STM of oxygen...

  20. An in situ method for diagnosing phase shifting interferometry

    Science.gov (United States)

    Shao, J.; Ma, D.; Zhang, H.; Xie, Y.

    2016-05-01

    Current diagnosing phase shifting interferometry is a time and funds consuming process. Hence a brief and effective method is necessary to satisfy the real-time testing. In this paper, mathematical solutions for errors were deduced from the difference of intensity patterns. Based on the diversity of error distributions, an effective method for distinguishing and diagnosing the error sources is proposed and verified by an elaborative designed simulation. In the actual comparison experiment, vibration, phase-shift error and intensity fluctuation were imposed to demonstrate this method. The results showed that this method can be applied into the real-time measurement and provide an in situ diagnosing technique.