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Sample records for situ stabilization technique

  1. 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.

  2. Cross-check of ex-situ and in-situ metrology of a bendable temperature stabilized KB mirror

    International Nuclear Information System (INIS)

    At the Advanced Light Source (ALS), we are developing broadly applicable, high-accuracy, in-situ, at-wavelength wavefront slope measurement techniques for Kirkpatrick-Baez (KB) mirror nano-focusing. In this paper, we report an initial cross-check of ex-situ and in-situ metrology of a bendable temperature stabilized KB mirror. This cross-check provides a validation of the in-situ shearing interferometry, currently under development at the ALS.

  3. Implementation of an ex situ stabilization technique at the Sand Springs superfund site to solidify and stabilize acid tar sludges involving a quick-lime based stabilization process and innovative equipment design

    Energy Technology Data Exchange (ETDEWEB)

    McManus, R.W. [SOUND Environmental Services, Inc., Dallas, TX (United States); Grajczak, P. [ARCO, Los Angeles, CA (United States); Wilcoxson, J.C. [ARCO, Plano, TX (United States); Webster, S.D. [Environmental Protection Agency, Dallas, TX (United States)

    1997-12-31

    An old refinery site was safely remediated a year before schedule and for 25% less than final engineering estimates for the stabilization remedy thanks to energetic project management and innovative design involving ex situ stabilization/solidification of acid tar sludges. A quicklime based process, Dispersion by Chemical Reaction (DCR{trademark}), was employed to solidify and stabilize (SS) over 103,000 cubic meters (135,000 cubic yards) of petroleum waste, mostly acidic tarry sludge. The SS process was selected over competing methods because it afforded minimal volume increase, could readily achieve Record of Decision (ROD) specified physical and chemical treatment goals, could be implemented with treatment equipment that minimized emissions, and could be performed with low reagent usage and at low cost. To ensure treatment goals were achieved and an accelerated schedule met, a custom designed and fabricated transportable treatment unit (TTU) was employed to implement the process. The treated material was visually soil-like in character, it was left in stockpiles for periods of time, and it was placed and compacted in the on site landfill using standard earth-moving equipment.

  4. Implementation of an ex situ stabilization technique at the Sand Springs superfund site to solidify and stabilize acid tar sludges involving a quick-lime based stabilization process and innovative equipment design

    International Nuclear Information System (INIS)

    An old refinery site was safely remediated a year before schedule and for 25% less than final engineering estimates for the stabilization remedy thanks to energetic project management and innovative design involving ex situ stabilization/solidification of acid tar sludges. A quicklime based process, Dispersion by Chemical Reaction (DCR trademark), was employed to solidify and stabilize (SS) over 103,000 cubic meters (135,000 cubic yards) of petroleum waste, mostly acidic tarry sludge. The SS process was selected over competing methods because it afforded minimal volume increase, could readily achieve Record of Decision (ROD) specified physical and chemical treatment goals, could be implemented with treatment equipment that minimized emissions, and could be performed with low reagent usage and at low cost. To ensure treatment goals were achieved and an accelerated schedule met, a custom designed and fabricated transportable treatment unit (TTU) was employed to implement the process. The treated material was visually soil-like in character, it was left in stockpiles for periods of time, and it was placed and compacted in the on site landfill using standard earth-moving equipment

  5. In situ solution mining technique

    International Nuclear Information System (INIS)

    A method of in situ solution mining is disclosed in which a primary leaching process employing an array of 5-spot leaching patterns of production and injection wells is converted to a different pattern by converting to injection wells all the production wells in alternate rows

  6. Laboratory-performance criteria for in situ waste-stabilization materials

    International Nuclear Information System (INIS)

    The Department of Energy (DOE) Landfill Stabilization Focus Area is investigating a variety of in situ placement methods, grout materials, and characterization techniques for the stabilization of buried low-level transuranic-contaminated waste at Department of Energy sites. In situ stabilization involves underground injection or placement of substances to isolate, treat, or contain buried contaminants. Performance criteria were developed to evaluate various candidate stabilization materials for both long-term stabilization and interim stabilization or retrieval. The criteria are go/no-go, ready, and preliminary. The criterion go/no-go eliminates technologies that are not applicable for in situ treatment of buried waste. The criterion ready indicates that the technology is sufficiently developed and proven to be field demonstrated full-scale. The criterion preliminary indicates the prospective technologies to be potentially applicable to in situ buried waste stabilization, but further development is needed before the technology is ready for field-scale demonstration

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

    International Nuclear Information System (INIS)

    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 10-5 parts per year. 32 figures, 30 tables

  8. In situ containment and stabilization of buried waste. Annual report FY 1992

    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.

  9. Latex-modified grouts for in-situ stabilization of buried transuranic/mixed waste

    International Nuclear Information System (INIS)

    The Department of Applied Science at Brookhaven national Laboratory was requested to investigate latex-modified grouts for in-situ stabilization of buried TRU/mixed waste for INEL. The waste exists in shallow trenches that were backfilled with soil. The objective was to formulate latex-modified grouts for use with the jet grouting technique to enable in-situ stabilization of buried waste. The stabilized waste was either to be left in place or retrieved for further processing. Grouting prior to retrieval reduces the potential release of contaminants. Rheological properties of latex-modified grouts were investigated and compared with those of conventional neat cement grouts used for jet grouting

  10. In situ formation of magnetic-luminescent, bi-functional, polymer-stabilized cerium sulfide nanoparticles

    International Nuclear Information System (INIS)

    Polymer-stabilized paramagnetic and fluorescent rare-earth metal sulfide (cerium sulfide, Ce2S3) nanoparticles have been synthesized by using an 'in situ polymerization and composite formation' (IPCF) technique (Mallick et al. in J. Appl. Phys. 106:074303, 2009) at room temperature. Encapsulated cerium sulfide nanoparticles showed photoluminescence when excited with laser irradiation. The composite material exhibited a paramagnetic behavior due to the in situ formation of magnetic Ce3+ ionic species at the reaction condition. (orig.)

  11. Optical metrology techniques for dimensional stability measurements:

    OpenAIRE

    Ellis, Jonathan David

    2010-01-01

    This thesis work is optical metrology techniques to determine material stability. In addition to displacement interferometry, topics such as periodic nonlinearity, Fabry-Perot interferometry, refractometry, and laser stabilization are covered.

  12. 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.

  13. In situ uranium stabilization by microbial metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Turick, Charles E. [Environmental Science and Biotechnology, Savannah River National Laboratory, Building 999W, Aiken, SC 29808 (United States)], E-mail: Charles.Turick@srnl.doe.gov; Knox, Anna S. [Environmental Science and Biotechnology, Savannah River National Laboratory, Building 999W, Aiken, SC 29808 (United States); Leverette, Chad L.; Kritzas, Yianne G. [Department of Chemistry and Physics, University of South Carolina Aiken, Aiken, SC 29801 (United States)

    2008-06-15

    Microbial melanin production by autochthonous bacteria was explored in this study as a means to increase U immobilization in U contaminated soil. This article demonstrates the application of bacterial physiology and soil ecology for enhanced U immobilization in order to develop an 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), South Carolina, as a result of tyrosine amendments. Bacterial densities of pyomelanin producers were >10{sup 6} cells per g wet soil. Pyomelanin demonstrated U complexing 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 a field test demonstrated increased U sequestration capacity following pyomelanin production up to 13 months after tyrosine treatments.

  14. In-situ dewatering techniques for uranium mill tailings

    International Nuclear Information System (INIS)

    The state-of-the-art regarding methods for the in-place dewatering of uranium mill tailings is described. Since large amounts of water in tailing impoundments can cause long-term seepage problems, drainage of the tailings both during operations and during the reclamation stage is highly desirable. Dewatering of tailings also provides for settlement prior to the placement of the cover and increases the pile's stability for earth-moving equipment during site reclamation and cover placement. The application of various drainage techniques is discussed with regard to their effectiveness in minimizing the amount of water remaining in an impoundment during long-term reclamation. Drainage techniques that are reviewed include underdrain gravity-flow systems, single wells and well-points, electro-osmosis, vertical drains, and evapotranspiration. It has been shown that the underdrain gravity systems provide an effective and reliable means of dewatering tailings. If feasible, they will probably prove to be the best option for the in situ dewatering of tailings because of their practicality and relatively low cost. The other methods would be recommended only as backup systems or in existing impoundments that do not have underdrain systems

  15. A Technique for In Situ Ballistic Electron Emission Microscopy

    Science.gov (United States)

    Balsano, Robert; Garramone, John; Labella, Vincent

    2012-02-01

    Ballistic electron emission microscopy (BEEM) is a scanning tunneling microscopy (STM) technique that can measure transport of hot electrons through materials and interfaces with high spatial and energetic resolution. BEEM requires an additional contact to ground the metal base layer of a metal semiconductor junction. Performing BEEM in situ with the sample fabrication requires a custom built STM or modifying a commercial one to facilitate the extra contact, which leaves the technique to highly trained experts. This poster will describe our work to develop a special silicon substrate that has the extra contact built in to enable in situ BEEM without modifications to the STM. Electrically isolated contact traces are lithographically patterned ex situ onto the silicon substrate and connected to the BEEM sample plate which is then inserted into the ultra-high vacuum chamber. The metal is then deposited through a shadow mask and then mounted in situ onto the STM for BEEM measurements. BEEM measurements comparing both in situ and ex situ deposited films will be presented.

  16. Floc Stabilization for Multiple Microscopic Techniques

    OpenAIRE

    Droppo, I. G.; Flannigan, D. T.; Leppard, G. G.; Jaskot, C.; Liss, S. N.

    1996-01-01

    A nondestructive stabilization technique for the characterization of microbial flocs which permits the application of correlative microscopic techniques is described. Flocs embedded in agarose are retained in a porous, resilient medium which allows for the transport, staining, washing, and subsampling of the flocculated material directly within a plankton chamber with minimal or no destructive forces. A single agarose disc can be subdivided into numerous sections for analysis by several micro...

  17. In situ stabilization wall for containment and hot spot retrieval

    International Nuclear Information System (INIS)

    This paper presents the results of a full scale field demonstration of a in situ stabilization technology applicable to buried transuranic waste. The technology involves creating a jet grouted wall around selected regions or hot spots within a buried waste site. The resulting wall provides a barrier against further horizontal migration of the contaminants and allows vertical digging of material inside the wall, thus minimizing waste during a hot spot removal action. The demonstration involved creating a open-quotes Uclose quotes shaped wall in the interior of a full sized, simulated waste pit. The wall simulated the main features of a four sided wall. The demonstration also involved a destructive examination and a stability test for a hot spot retrieval scenario

  18. In-situ stabilization of mixed waste contaminated soil

    International Nuclear Information System (INIS)

    A full-scale field demonstration was conducted to evaluate in for stabilizing an inactive RCRA land treatment site at a DOE facility in Ohio. Subsurface silt and clay deposits were contaminated principally with up to 500 mg/kg of trichloroethylene and other halocarbons, but also trace to low levels of Pb, Cr, 235U, and 99Tc. In situ solidification was studied in three, 3.1 m diameter by 4.6 m deep columns. During mixing, a cement-based grout was injected and any missions from the mixed region were captured in a shroud and treated by filtration and carbon adsorption. During in situ processing, operation and performance parameters were measured, and soil cores were obtained from a solidified column 15 months later. Despite previous site-specific treatability experience, there were difficulties in selecting a grout with the requisite treatment agents amenable to subsurface injection and at a volume adequate for distribution throughout the mixed region while minimizing volume expansion. observations during the demonstration revealed that in situ solidification was rapidly accomplished (e.g., >90 m3/d) with limited emissions of volatile organics (i.e., -6 cm/s vs. 10-8 cm/s). Leaching tests performed on the treated samples revealed non-detectable to acceptably low concentrations of all target contaminants

  19. In-situ vacuum deposition technique of lithium on neutron production target for BNCT

    Energy Technology Data Exchange (ETDEWEB)

    Ishiyama, S. [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Baba, Y., E-mail: baba.yuji@jaea.go.jp [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Fujii, R.; Nakamura, M.; Imahori, Y. [Cancer Intelligence Care Systems, Inc., Ariake 3-5-7, Koutou-ku, Tokyo 135-0063 (Japan)

    2012-10-01

    For the purpose of avoiding the radiation blistering of the lithium target for neutron production in BNCT (Boron Neutron Capture Therapy) device, trilaminar Li target, of which palladium thin layer was inserted between cupper substrate and Li layer, was newly designed. In-situ vacuum deposition and electrolytic coating techniques were applied to validate the method of fabrication of the Li/Pd/Cu target, and the layered structures of the synthesized target were characterized. In-situ vacuum re-deposition technique was also established for repairing and maintenance for lithium target damaged. Following conclusions were derived; (1) Uniform lithium layers with the thickness from 1.6 nm to a few hundreds nanometer were formed on Pd/Cu multilayer surface by in situ vacuum deposition technique using metallic lithium as a source material. (2) Re-deposition of lithium layer on Li surface can be achieved by in situ vacuum deposition technique. (3) Small amount of water and carbonate was observed on the top surface of Li. But the thickness of the adsorbed layer was less than monolayer, which will not affect the quality of the Li target. (4) The formation of Pd-Li alloy layer was observed at the Pd and Li interface. The alloy layer would contribute to the stability of the Li layer.

  20. In-situ containment and stabilization of buried waste

    International Nuclear Information System (INIS)

    In FY 1993 research continued on development and testing of grout materials for in-situ containment and stabilization of buried waste. Specifically, the work was aimed at remediation of the Chemical Waste Landfill (CWL) at Sandia National Laboratories (SNL) in Albuquerque, New Mexico as part of the Mixed Waste Landfill Integrated Demonstration (MWLID). The work on grouting materials was initiated in FY 1992 and the accomplishments for that year are documented in the previous annual report (Allan, Kukacka and Heiser, 1992). The remediation plan involves stabilization of the chromium plume, placement of impermeable vertical and horizontal barriers to isolate the landfill and installation of a surface cap. The required depth of subsurface barriers is approximately 33 m (100 ft). The work concentrated on optimization of grout formulations for use as grout and soil cement barriers and caps. The durability of such materials was investigated, in addition to shrinkage cracking resistance, compressive and flexural strength and permeability. The potential for using fibers in grouts to control cracking was studied. Small scale field trials were conducted to test the practicality of using the identified formulations and to measure the long term performance. Large scale trials were conducted at Sandia as part of the Subsurface Barrier Emplacement Technology Program. Since it was already determined in FY 1992 that cementitious grouts could effectively stabilize the chromium plume at the CWL after pre-treatment is performed, the majority of the work was devoted to the containment aspect

  1. In Situ Community Control of the Stability of Bioreduced Uranium

    Energy Technology Data Exchange (ETDEWEB)

    White, David C.

    2005-06-01

    In-well sediment incubators Direct estimation of reoxidation rates is difficult under field conditions. We have designed and are fabricating in-well sediment incubators for use in conducting a series of in situ experiments that will enable direct measurement of U(IV) removal rates from pre-reduced sediments with specific microbial and mineralogic amendments. By comparing U(IV) loss rates with different DIRB and SRB populations we will be able to clearly determine the relative impact of sulfate reducers vs. Fe reducers. The approach we propose also makes it possible to assess actual in situ conditions during the experiment and to directly observe reoxidation (or bioreduction) end points after the field experiment is completed without drilling. Finally, the production of in-well sediment incubators is relatively inexpensive and could ultimately become an alternative to field-scale electron donor amendment experiments as a means of assessing site response to bioremediation and long-term stability of both biostimulated and naturally bioattenuated sites.

  2. Application of in situ stress estimation methods in wellbore stability analysis under isotropic and anisotropic conditions

    Science.gov (United States)

    Gholami, Raoof; Rasouli, Vamegh; Aadnoy, Bernt; Mohammadi, Ramin

    2015-08-01

    Estimation of in situ stresses is a key step in many petroleum engineering applications, ranging from wellbore stability to sanding analysis and hydraulic fracturing design. Direct techniques conventionally used to determine in situ stresses are indeed very time consuming and expensive. These measurements would also be restricted as to the depth of acquisition, and generalization of the results to entire rock masses may not yield representative results. In this paper, applications of three indirect methods–Zoback’s polygon, shear moduli, and poroelastic–are studied to assess their applicability in providing reliable stress estimation under isotropic and anisotropic conditions. Determination of elastic, strength, and in situ stress parameters according to the assumption of each method for one of the vertical wells drilled in south Iran indicated that the shear moduli method is an appropriate approach for prediction of maximum horizontal stress within an interval where sufficient field data including leak-off tests are acquired. However, the poroelastic method seems to be a better method in prediction of in situ stresses under anisotropic conditions. This might be due to the presence of excessive shale formations in subsurface layers, causing structural or intrinsic anisotropy-based methods such as poroelastic equations to deliver more accurate results. However, making general conclusions based on studying a single vertical wellbore may not be sufficient, and therefore further studies are required.

  3. Dispersion stabilization of silver nanoparticles in synthetic lung fluid studied under in situ conditions

    Energy Technology Data Exchange (ETDEWEB)

    MacCuspie, R.I.; Allen, A.J.; Hackley, V.A. (NIST)

    2014-09-24

    The dispersion stabilization of silver nanoparticles (AgNPs) in synthetic lung fluid was studied to interrogate the effects on colloidal stability due to the principal constituents of the fluid. The colloidal stability of 20 nm citrate-AgNPs dispersed in the presence of each constituent of the synthetic lung fluid (individually, the complete fluid, and without additives) was observed during titration of increasing sodium chloride concentration. A variety of complementary in situ measurement techniques were utilized, including dynamic light scattering, ultraviolet-visible absorption spectroscopy, atomic force microscopy, and small-angle X-ray scattering, which provided a collective set of information that enabled far better understanding of the dispersion behavior in the fluid than any one technique alone. It was observed that AgNPs continued to adsorb bovine serum albumin (BSA) protein from the synthetic lung fluid solution as the sodium chloride concentration increased, until a maximum BSA coating was achieved prior to reaching the physiological sodium chloride concentration of 154 mmol L{sup -1}. BSA was determined to be the constituent of the synthetic lung fluid that is required to provide colloidal stability at high salt loadings, though the phospholipid constituent exerts a subtle effect. Additionally, as AgNPs are a distinctly different class of nanoparticles apart from the carbon nanotubes and titanium dioxide nanoparticles initially reported to be dispersible using this fluid, this work also demonstrates the broad applicability of synthetic lung fluid in providing stable dispersions for engineered nanoparticles for use in biological assays.

  4. Engineering feasibility analysis for in-situ stabilization of Canonsburg residues. [UMTRA project

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    The US Department of Energy is considering several methods for carrying out remedial actions in Canonsburg, Pennsylvania, at the site of an inactive uranium-processing mill. The main objective of this study is to determine the feasibility of in-situ stabilization as the remedial action. In-situ stabilization is an alternative to site decontamination and offsite disposal. The problems associated with offsite hauling of large quantities of contaminated material and with the location and development of a new disposal site could be avoided by the implementation of an in-situ stabilization concept. In addition, the in-situ approach would be more cost-effective than offsite disposal. This study will establish that a technically feasible and implementable in-situ stabilization concept can be developed that meets regulatory requirements and is cost effective. This study in no way commits the DOE to implement any specific actions described herein. 11 refs., 30 figs., 24 tabs.

  5. Engineering feasibility analysis for in-situ stabilization of Canonsburg residues

    International Nuclear Information System (INIS)

    The US Department of Energy is considering several methods for carrying out remedial actions in Canonsburg, Pennsylvania, at the site of an inactive uranium-processing mill. The main objective of this study is to determine the feasibility of in-situ stabilization as the remedial action. In-situ stabilization is an alternative to site decontamination and offsite disposal. The problems associated with offsite hauling of large quantities of contaminated material and with the location and development of a new disposal site could be avoided by the implementation of an in-situ stabilization concept. In addition, the in-situ approach would be more cost-effective than offsite disposal. This study will establish that a technically feasible and implementable in-situ stabilization concept can be developed that meets regulatory requirements and is cost effective. This study in no way commits the DOE to implement any specific actions described herein. 11 refs., 30 figs., 24 tabs

  6. Depth enhancement techniques for the in situ vitrification process

    International Nuclear Information System (INIS)

    In-situ vitrification (ISV) is a process by which electrical energy is supplied to a soil/waste matrix. The resulting Joule heat raises the temperature of the soil/waste matrix, producing a pool of molten soil. Since its inception, there have been many successful applications of the technology to both staged and actual waste sites. However, there has been some difficulty in extending the attainable treatment melt depth to levels greater than 5 m. Results obtained from application of two novel approaches for extending the ultimate treatment depth attainable with in-situ vitrification (ISV) are presented. In the first, the electrode design is modified to concentrate the Joule heat energy delivered to the soil/waste matrix in the lower region of the target melt zone. This electrode design has been dubbed the hot-tip electrode. Results obtained from both computational and experimental investigations of this design concept indicate that some benefit toward ISV depth enhancement was realized with these hot-tip electrodes. A second, alternative approach to extending process depth with ISV involves initiating the melt at depth and propagating it in either vertical direction (e.g., downward, upward, or both) to treat the target waste zone. A series of engineering-scale experiments have been conducted to assess the benefits of this approach. The results from these tests indicate that ISV may be effectively initiated and sustained using this subsurface start-up technique. A survey of these experiments and the associated results are presented herein, together with brief discussion of some considerations regarding setup and implementation of this subsurface start-up technique

  7. Development of an in situ loop-mediated isothermal amplification technique for chromosomal localization of DNA sequences

    Science.gov (United States)

    Meng, Qinglei; Wang, Shi; Zhang, Lingling; Huang, Xiaoting; Bao, Zhenmin

    2013-01-01

    In situ loop-mediated isothermal amplification (in situ LAMP) combines in situ hybridization and loop-mediated isothermal amplification (LAMP) techniques for chromosomal localization of DNA sequences. In situ LAMP is a method that is generally more specific and sensitive than conventional techniques such as fluorescence in situ hybridization (FISH), primed in situ labeling (PRINS), and cycling primed in situ labeling (C-PRINS). Here, we describe the development and application of in situ LAMP to identify the chromosomal localization of DNA sequences. To benchmark this technique, we successfully applied this technique to localize the major ribosomal RNA gene on the chromosomes of the Zhikong scallop ( Chlamys farreri).

  8. Bacterial Biotransformations for the In situ Stabilization of Plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Neu, Mary; Boukhalfa, Hakim; Icopini, Gary; Hersman, Larry; Lack, Joe; Priester, John; Olson, Scott; Holden, Patricia

    2005-04-20

    Plutonium contamination in the environment is generally low-level and may be present and transported in a range of forms (IV, V, VI). Current remediation strategies are costly, financially and in terms of increased exposure risk to people and the environment. In situ bacterial biostabilization is a promising alternative.

  9. Infrared techniques for quantifying protein structural stability.

    Science.gov (United States)

    Vrettos, John S; Meuse, Curtis W

    2009-07-01

    Biopharmaceutical and biotechnology companies and regulatory agencies require novel methods to determine the structural stabilities of proteins and the integrity of protein-protein, protein-ligand, and protein-membrane interactions that can be applied to a variety of sample states and environments. Infrared spectroscopy is a favorable method for a number of reasons: it is adequately sensitive to minimal sample amounts and is not limited by the molecular weight of the sample; yields spectra that are simple to evaluate; does not require protein modifications, a special supporting matrix, or internal standard; and is applicable to soluble and membrane proteins. In this paper, we investigate the application of infrared spectroscopy to the quantification of protein structural stability by measuring the extent of amide hydrogen/deuterium exchange in buffers containing D(2)O for proteins in solution and interacting with ligands and lipid membranes. We report the thermodynamic stability of several protein preparations, including chick egg-white lysozyme, trypsin bound by benzamidine inhibitors, and cytochrome c interacting with lipid membranes of varying net-negative surface charge density. The results demonstrate that infrared spectroscopy can be used to compare protein stability as determined by amide hydrogen/deuterium exchange for a variety of cases. PMID:19327337

  10. Materials testing for in situ stabilization treatability study of INEEL mixed wastes soils

    International Nuclear Information System (INIS)

    This report describes the contaminant-specific materials testing phase of the In Situ Stabilization Comprehensive Environment Response, Compensation, and Liability Act (CERCLA) Treatability Study (TS). The purpose of materials testing is to measure the effectiveness of grouting agents to stabilize Idaho National Engineering and Environmental Laboratory (INEEL) Acid Pit soils and select a grout material for use in the Cold Test Demonstration and Acid Pit Stabilization Treatability Study within the Subsurface Disposal Area (SDA) at the Radioactive Waste Management Complex (RWMC). Test results will assist the selecting a grout material for the follow-on demonstrations described in Test Plan for the Cold Test Demonstration and Acid Pit Stabilization Phases of the In Situ Stabilization Treatability Study at the Radioactive Waste Management Complex

  11. Transient Stability Assessment using Decision Trees and Fuzzy Logic Techniques

    Directory of Open Access Journals (Sweden)

    A. Y. Abdelaziz

    2013-09-01

    Full Text Available Many techniques are used for Transient Stability assessment (TSA of synchronous generators encompassing traditional time domain state numerical integration, Lyapunov based methods, probabilistic approaches and Artificial Intelligence (AI techniques like pattern recognition and artificial neural networks.This paper examines another two proposed artificial intelligence techniques to tackle the transient stability problem. The first technique is based on the Inductive Inference Reasoning (IIR approach which belongs to a particular family of machine learning from examples. The second presents a simple fuzzy logic classifier system for TSA. Not only steady state but transient attributes are used for transient stability estimation so as to reflect machine dynamics and network changes due to faults.The two techniques are tested on a standard test power system. The performance evaluation demonstrated satisfactory results in early detection of machine instability. The advantage of the two techniques is that they are straightforward and simple for on-line implementation.

  12. Experimental techniques for mass measurement far from stability

    Energy Technology Data Exchange (ETDEWEB)

    Orr, N

    2001-01-01

    The measurement of nuclear masses is a fundamental tool to probe nuclear structure ar from stability. A review of the techniques that have been most commonly employed to undertake such measurements is presented. (author)

  13. Experimental techniques for mass measurement far from stability

    International Nuclear Information System (INIS)

    The measurement of nuclear masses is a fundamental tool to probe nuclear structure ar from stability. A review of the techniques that have been most commonly employed to undertake such measurements is presented. (author)

  14. Power system stabilizers based on modern control techniques

    Energy Technology Data Exchange (ETDEWEB)

    Malik, O.P.; Chen, G.P.; Zhang, Y.; El-Metwally, K. [Calgary Univ., AB (Canada). Dept. of Electrical and Computer Engineering

    1994-12-31

    Developments in digital technology have made it feasible to develop and implement improved controllers based on sophisticated control techniques. Power system stabilizers based on adaptive control, fuzzy logic and artificial networks are being developed. Each of these control techniques possesses unique features and strengths. In this paper, the relative performance of power systems stabilizers based on adaptive control, fuzzy logic and neural network, both in simulation studies and real time tests on a physical model of a power system, is presented and compared to that of a fixed parameter conventional power system stabilizer. (author) 16 refs., 45 figs., 3 tabs.

  15. Introduction to in situ leaching technique and facility at Smith Ranch uranium project in USA

    International Nuclear Information System (INIS)

    The history of in situ leaching of uranium in USA is reviewed. Some techniques and parameters of alkaline in situ leach at Smith Ranch uranium project are introduced, including well field, sorption, elution, precipitation, filter and drying, automatic control, radiation protection, safety and environmental protection. (authors)

  16. TESTING TECHNIQUE OF MOTOR PETROL PHYSICAL STABILITY ESTIMATION AND FORECASTING

    Directory of Open Access Journals (Sweden)

    Sergey V. Boychenko

    2009-04-01

    Full Text Available  The technique of petrol physical stability assessment and forecasting was tested. The results of study aimed at investigation of modern motor petrols evaporability are presented in the article. The refractive index is shown to be useful tool in making prognosis about evaporation losses of motor petrol. The validation of this technique was conducted and recommendations are given on its application.

  17. Hp-?-CD-voriconazole in situ gelling system for ocular drug delivery: in vitro, stability, and antifungal activities assessment.

    Science.gov (United States)

    Pawar, Pravin; Kashyap, Heena; Malhotra, Sakshi; Sindhu, Rakesh

    2013-01-01

    The objective of the present study was to design ophthalmic delivery systems based on polymeric carriers that undergo sol-to-gel transition upon change in temperature or in the presence of cations so as to prolong the effect of HP- ? -CD Voriconazole (VCZ) in situ gelling formulations. The in situ gelling formulations of Voriconazole were prepared by using pluronic F-127 (PF-127) or with combination of pluronic F-68 (PF-68) and sodium alginate by cold method technique. The prepared formulations were evaluated for their physical appearance, drug content, gelation temperature (T gel), in vitro permeation studies, rheological properties, mucoadhesion studies, antifungal studies, and stability studies. All batches of in situ formulations had satisfactory pH ranging from 6.8 to 7.4, drug content between 95% and 100%, showing uniform distribution of drug. As the concentration of each polymeric component was increased, that is, PF-68 and sodium alginate, there was a decrease in T gel with increase in viscosity and mucoadhesive strength. The in vitro drug release decreased with increase in polymeric concentrations. The stability data concluded that all formulations showed the low degradation and maximum shelf life of 2 years. The antifungal efficiency of the selected formulation against Candida albicans and Asperigillus fumigatus confirmed that designed formulation has prolonged effect and retained its properties against fungal infection. PMID:23762839

  18. EPA SITE DEMONSTRATION OF THE INTERNATIONAL WASTE TECHNOLOGIES/GEO-CON IN SITU STABILIZATION/ SOLIDIFICATION PROCESS

    Science.gov (United States)

    This paper presents an EPA evaluation of the first field demonstration of an in situ stabilization/solidification process for contaminated soil under the EPA Superfund Innovative Technology Evaluation (SITE) program. Demonstration of this process was a joint effort of two vendors...

  19. Investigating structure-property relationships in cathode materials via combined ex-situ and in-situ diffraction techniques

    International Nuclear Information System (INIS)

    While anode and electrolyte materials continue to see significant advances, cathode materials remain underdeveloped in comparison. As a battery's performance is determined by its weakest component further improvements to cathode materials are essential. Given the complex chemical and structural changes which can take place in cathode materials on cycling, a range of advanced characterization techniques must be utilised in order to understand the properties well enough to then improve upon them. A combination and ex-situ type dialyses has been performed on the cathode material Li0.18Sr0.66Ti0.5BNb0.5O3. Ex-situ neutron diffraction experiments, following the chemical insertion of lithium enabled the location of lithium within the structure to be accurately determined through Rietveld refinement and calculation of Fourier difference maps. More significantly, the evolution of phases and structural change in this material has been followed utilizing both in-situ neutron and synchrotron diffraction experiments. Sequential Rietveld refinements have allowed the change in structure to be directly correlated with the observed electrochemical properties. Specifically, due to the real time collection of structure; data as a function of discharge. the rate of structural change was measured and directly correlated with electrochemical portfolio. This contribution will demonstrate how a combination of ex-situ diffraction of chemical and electrochemical insertion of lithium as well as in-situ diffraction of electrochemical insertion of lithium can provide a robust picture of how the structure influences properties.

  20. In-situ stabilization of radioactive zirconium swarf

    Energy Technology Data Exchange (ETDEWEB)

    Hess, Clay C.

    1997-12-01

    The method for treating ignitable cutting swarf in accordance with the present invention involves collecting cutting swarf in a casting mold underwater and injecting a binder mixture comprising vinyl ester styrene into the vessel to fill void volume; and form a mixture comprising swarf and vinyl ester styrene; and curing the mixture. The method is especially useful for stabilizing the ignitable characteristics of radioactive zirconium cutting swarf, and can be used to solidify zirconium swarf, or other ignitable finely divided material, underwater. The process could also be performed out of water with other particulate wastes.

  1. Phase stability and in situ growth stresses in Ti/Nb thin films

    International Nuclear Information System (INIS)

    The thin film growth evolution associated with changes in Ti’s body-centered cubic (bcc) to hexagonal close-packed (hcp) phase transformations in Ti/Nb multilayered thin films is addressed. An in situ laser interferometer curvature measurement technique was used to monitor the intrinsic growth stresses for a series of these multilayers, with each multilayer having a different bilayer spacing but equivalent individual layer thickness. The initial Ti layer grows on Nb with a positive stress-thickness product slope up to ?2 nm, whereupon it transitions to a slightly negative growth stress slope. This transition has been associated with the bcc to hcp Ti transformation. The Nb growth exhibited a significantly steeper stress-thickness product slope regardless of the Ti phase state. The decreasing interfacial stress between the two layers contributed to a collectively more compressive stress state for the multilayer. Atom probe tomography revealed Ti segregation to the columnar grain boundaries and significant Nb intermixing into the bcc Ti layer, which is rationalized as a surface exchange process driven by interfacial thermodynamic considerations. Using a molecular dynamics deposition simulation, this intermixing was found to be paramount in stabilizing the bcc Ti layer to larger layer thicknesses

  2. Bioengineering Techniques for Soil Erosion Protection and Slope Stabilization

    OpenAIRE

    Georgi, Julia; Stathakopoulos, Ioannis

    2006-01-01

    The use of bio-engineering methods for soil erosion protection and slope stabilization has a long tradition. Old methods with rocks and plants, structures of timber have been used over the past centuries. Recently these old soil conservation and stabilization techniques have been rediscovered and improved. Biotechnical engineering methods have become part of geotechnical and hydraulic engineering and have helped bridge the gap between classical engineering disciplines, land use management, la...

  3. Ignition technique for an in situ oil shale retort

    Science.gov (United States)

    Cha, Chang Y. (Golden, CO)

    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.

  4. Single Molecule Techniques for Advanced in situ Hybridization

    International Nuclear Information System (INIS)

    One of the most significant achievements of modern science is completion of the human genome sequence, completed in the year 2000. Despite this monumental accomplishment, researchers have only begun to understand the relationships between this three-billion-nucleotide genetic code and the regulation and control of gene and protein expression within each of the millions of different types of highly specialized cells. Several methodologies have been developed for the analysis of gene and protein expression in situ, yet despite these advancements, the pace of such analyses is extremely limited. Because information regarding the precise timing and location of gene expression is a crucial component in the discovery of new pharmacological agents for the treatment of disease, there is an enormous incentive to develop technologies that accelerate the analytical process. Here we report on the use of plasmon resonant particles as advanced probes for in situ hybridization. These probes are used for the detection of low levels of gene-probe response and demonstrate a detection method that enables precise, simultaneous localization within a cell of the points of expression of multiple genes or proteins in a single sample

  5. An improved technique for the in situ detection of DNA after polymerase chain reaction amplification.

    OpenAIRE

    Nuovo, G J; Gallery, F.; MacConnell, P.; Becker, J.; Bloch, W.

    1991-01-01

    In situ detection of polymerase chain reaction (PCR)-amplified DNA in cell and tissue preparations previously required 5 to 7 primer pairs designed to generate a long (greater than 1,000 base pair) product. The authors describe a nonisotopic PCR in situ technique, employing a single primer pair and target sequences as short as 115 base pairs, that can detect one target molecule per cell. The essential procedural change is to withhold the DNA polymerase or primers until the reaction temperatur...

  6. 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.

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

    International Nuclear Information System (INIS)

    Highlights: ? Insitu Raman is used to monitor the thermal stability of Wells Dawson heteropolyacid. ? TP-Raman follows the gradual dehydration and the effect on the secondary structure. ? Wells-Dawson heteropolyacid does not decompose into Keggin and WO3 units below 600oC -- 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 H6P2W18O62.xH2O (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 WO3 phases provides further evidence that the phosphotungstic heteropolyanion does not decomposes towards those materials at temperatures below 600 oC.

  8. In situ measurement of soil moisture: a comparison of techniques

    Science.gov (United States)

    Walker, Jeffrey P.; Willgoose, Garry R.; Kalma, Jetse D.

    2004-06-01

    A number of automated techniques for point measurement of soil moisture content have been developed to an operational level over the past few decades. While each of those techniques have been individually evaluated by the thermogravimetric (oven drying and weighing) method, typically under laboratory conditions, there have been few studies which have made a direct comparison between the various techniques, particularly under field conditions. This paper makes an inter-comparison of the Virrib ®, Campbell Scientific CS615 reflectometer, Soil Moisture Equipment Corporation TRASE ® buriable- and connector-type time domain reflectometry (TDR) soil moisture sensors, and a comparison of the connector-type TDR sensor with thermogravimetric measurements for data collected during a 2-year field study. Both qualitative and quantitative comparisons between the techniques are made, and comparisons made with results from a simple water balance 'bucket' model and a Richards equation based model. It was found that the connector-type TDR sensors produced soil moisture measurements within the ±2.5% v/v accuracy specification of the manufacturer as compared to thermogravimetric data when using the manufacturer's calibration relationship. However, comparisons with the water balance model showed that Virrib and buriable-type TDR sensors yielded soil moisture changes that exceeded rainfall amounts during infiltration events. It was also found that the CS615 reflectometer yielded physically impossible soil moisture measurements (greater than the soil porosity) during periods of saturation. Moreover, the buriable-type TDR measurements of soil moisture content were systematically less than the Virrib measurements by approximately 10% v/v. In addition to the good agreement with thermogravimetric measurements, the connector-type TDR soil moisture measurements yielded the best agreement with Richards equation based model predictions of soil moisture content, with Virrib sensors yielding a poor agreement in the deeper layers. This study suggests that connector-type TDR sensors give the most accurate measurements of soil moisture content out of the sensor types tested.

  9. Straightforward technique for in situ imaging of spin-coated thin films

    Science.gov (United States)

    Toolan, Daniel T. W.

    2015-02-01

    Spin-coating provides a facile method for the production of highly uniform thin films that have applications as photoresists, coatings, and in organic electronics. Due to the rapid high-speed nature of spin-coating, obtaining data in situ has proved problematic. Recently, a number of in situ characterization techniques have provided new insights into the processes occurring during spin-coating. This paper demonstrates a straightforward method for obtaining in situ optical reflectance images during spin-coating that provide insights into film thinning dynamics, the origins of surface inhomogeneities caused by contaminated substrates, and crystallization processes. This technique could be easily implemented industrially and in many laboratories and will allow for a better understanding of the spin-coating process.

  10. Use of agar agar stabilized milled zero-valent iron particles for in situ groundwater remediation

    Science.gov (United States)

    Schmid, Doris; Velimirovi?, Milica; Wagner, Stephan; Mici? Batka, Vesna; von der Kammer, Frank; Hofmann, Thilo

    2015-04-01

    A major obstacle for use of nanoscale zero-valent iron (nZVI) particles as a nontoxic material for effective in situ degradation of chlorinated aliphatic hydrocarbons (CAHs) is the high production cost. For that reason, submicro-scale milled zero-valent iron particles were recently developed (milled ZVI, UVR-FIA, Germany) by grinding macroscopic raw materials of elementary iron as a cheaper alternative to products produced by solid-state reduction. However, milled ZVI particles tend to aggregate and due to the rather large particle size (d50= 11.9 µm) also rapidly sediment. To prevent aggregation and consequently sedimentation of milled ZVI particles and therefore improve the mobility after in situ application, the use of a stabilizer is considered in literature as a most promising option. In this study, milled ZVI particles (1 g L-1 of particle concentration) were stabilized by environmentally friendly polymer agar agar (>0.5 g L-1), which had a positive impact on the milled ZVI stability. Sedimentation rate was significantly decreased by increasing the suspension viscosity. Column transport experiments were performed for bare and agar agar stabilized milled ZVI particles in commercially available fine grained quartz sand (DORSILIT® Nr.8, Gebrüder Dorfner GmbH Co, Germany) and different porous media collected from brownfields. The experiments were carried out under field relevant injection conditions of 100 m d-1. The maximal travel distance (LT) of less than 10 cm was determined for non-stabilized suspension in fine grained quartz sand, while agar agar (1 g L-1) stabilized milled ZVI suspension revealed LT of 12 m. Similar results were observed for porous media from brownfields showing that mobility of agar agar stabilized particle suspensions was significantly improved compared to bare particles. Based on the mobility data, agar agar stabilized milled zero-valent iron particles could be used for in situ application. Finally, lab-scale batch degradation experiments were performed to determine the impact of agar agar on the reactivity of milled ZVI and investigate the apparent corrosion rate of particles by quantifying the hydrogen gas generated by anaerobic corrosion of milled ZVI. The results indicate that agar agar had a positive impact on the milled ZVI stability and mobility, however adverse impact on the reactivity towards trichloroethene (TCE) was observed compared to the non-stabilized material. On the other hand, this study shows that the apparent corrosion rate of non-stabilized and agar agar stabilized milled ZVI particles is in the same order of magnitude. These data indicate that the dechlorination pathway of TCE by agar agar stabilized milled ZVI particles is possibly impacted by blocking of the reactive sites and not hydrogen revealed during particles corrosion. Finally, calculated longevity of the particles based on the apparent corrosion rate is significantly prolonged compared to the longevity of the nZVI particles reported in previous studies. This research receives funding from the European Union's Seventh Framework Programme FP7/2007-2013 under grant agreement n°309517.

  11. Two-dimensional in situ metrology of X-ray mirrors using the speckle scanning technique.

    Science.gov (United States)

    Wang, Hongchang; Kashyap, Yogesh; Laundy, David; Sawhney, Kawal

    2015-07-01

    In situ metrology overcomes many of the limitations of existing metrology techniques and is capable of exceeding the performance of present-day optics. A novel technique for precisely characterizing an X-ray bimorph mirror and deducing its two-dimensional (2D) slope error map is presented. This technique has also been used to perform fast optimization of a bimorph mirror using the derived 2D piezo response functions. The measured focused beam size was significantly reduced after the optimization, and the slope error map was then verified by using geometrical optics to simulate the focused beam profile. This proposed technique is expected to be valuable for in situ metrology of X-ray mirrors at synchrotron radiation facilities and in astronomical telescopes. PMID:26134795

  12. In-situ stabilization of TRU/mixed waste project at the INEEL

    Energy Technology Data Exchange (ETDEWEB)

    Milian, L.W.; Heiser, J.H.; Adams, J.W.; Rutenkroeger, S.P.

    1997-08-01

    Throughout the DOE complex, buried waste poses a threat to the environment by means of contaminant transport. Many of the sites contain buried waste that is untreated, prior to disposal, or insufficiently treated, by today`s standards. One option to remedy these disposal problems is to stabilize the waste in situ. This project was in support of the Transuranic/Mixed Buried Waste - Arid Soils product line of the Landfill Focus Area, which is managed currently by the Idaho National Engineering Laboratory (BNL) provided the analytical laboratory and technical support for the various stabilization activities that will be performed as part of the In Situ Stabilization of TRU/Mixed Waste project at the INEL. More specifically, BNL was involved in laboratory testing that included the evaluation of several grouting materials and their compatibility, interaction, and long-term durability/performance, following the encapsulation of various waste materials. The four grouting materials chosen by INEL were: TECT 1, a two component, high density cementious grout, WAXFIX, a two component, molten wax product, Carbray 100, a two component elastomeric epoxy, and phosphate cement, a two component ceramic. A simulated waste stream comprised of sodium nitrate, Canola oil, and INEL soil was used in this study. Seven performance and durability tests were conducted on grout/waste specimens: compressive strength, wet-dry cycling, thermal analysis, base immersion, solvent immersion, hydraulic conductivity, and accelerated leach testing.

  13. In-situ measurement of mechanical properties of structural components using cyclic ball indentation technique

    International Nuclear Information System (INIS)

    Material properties of components change during service due to environmental conditions. Measurement of mechanical properties of the components is important for assessing their fitness for service. In many instances, it is not possible to remove sizable samples from the component for doing the measurement in laboratory. In-situ technique for measurement of mechanical properties has great significance in such cases. One of the nondestructive methods that can be adopted for in-situ application is based on cyclic ball indentation technique. It involves multiple indentation cycles (at the same penetration location) on a metallic surface by a spherical indenter. Each cycle consists of indentation, partial unload and reload sequences. Presently, commercial systems are available for doing indentation test on structural component for limited applications. But, there is a genuine need of remotely operable compact in-situ property measurement system. Considering the importance of such applications Reactor Engineering Division of BARC has developed an In-situ Property Measurement System (IProMS), which can be used for in-situ measurement of mechanical properties of a flat or tubular component. This paper highlights the basic theory of measurement, qualification tests on IProMS and results from tests done on flat specimens and tubular component. (author)

  14. An overview on in situ micronization technique – An emerging novel concept in advanced drug delivery

    Science.gov (United States)

    Vandana, K.R.; Prasanna Raju, Y.; Harini Chowdary, V.; Sushma, M.; Vijay Kumar, N.

    2013-01-01

    The use of drug powders containing micronized drug particles has been increasing in several pharmaceutical dosage forms to overcome the dissolution and bioavailability problems. Most of the newly developed drugs are poorly water soluble which limits dissolution rate and bioavailability. The dissolution rate can be enhanced by micronization of the drug particles. The properties of the micronized drug substance such as particle size, size distribution, shape, surface properties, and agglomeration behaviour and powder flow are affected by the type of micronization technique used. Mechanical communition, spray drying and supercritical fluid (SCF) technology are the most commonly employed techniques for production of micronized drug particles but the characteristics of the resulting drug product cannot be controlled using these techniques. Hence, a newer technique called in situ micronization is developed in order to overcome the limitations associated with the other techniques. This review summarizes the existing knowledge on in situ micronization techniques. The properties of the resulting drug substance obtained by in situ micronization were also compared. PMID:25161371

  15. An overview on in situ micronization technique - An emerging novel concept in advanced drug delivery.

    Science.gov (United States)

    Vandana, K R; Prasanna Raju, Y; Harini Chowdary, V; Sushma, M; Vijay Kumar, N

    2014-09-01

    The use of drug powders containing micronized drug particles has been increasing in several pharmaceutical dosage forms to overcome the dissolution and bioavailability problems. Most of the newly developed drugs are poorly water soluble which limits dissolution rate and bioavailability. The dissolution rate can be enhanced by micronization of the drug particles. The properties of the micronized drug substance such as particle size, size distribution, shape, surface properties, and agglomeration behaviour and powder flow are affected by the type of micronization technique used. Mechanical communition, spray drying and supercritical fluid (SCF) technology are the most commonly employed techniques for production of micronized drug particles but the characteristics of the resulting drug product cannot be controlled using these techniques. Hence, a newer technique called in situ micronization is developed in order to overcome the limitations associated with the other techniques. This review summarizes the existing knowledge on in situ micronization techniques. The properties of the resulting drug substance obtained by in situ micronization were also compared. PMID:25161371

  16. A new technique for in situ measurement of the composition of neutral gas in interplanetary space

    Science.gov (United States)

    Gruntman, Michael A.

    1993-01-01

    Neutral atoms in interplanetary space play an important role in many processes relevant to the formation and evolution of the Solar System. An experimental approach is proposed for in situ atom detection based on the conversion of neutral atoms to negative ions at a specially prepared sensitive surface. Negative ions are subsequently analyzed and detected in an essentially noise-free mode. The use of the technique for in situ study of the composition of neutral interstellar atoms is considered. It is shown that interstellar H, D, and O atoms and possibly H2 molecules can be measured by the proposed technique. The experiment can be performed from a high-apogee Earth-orbiting satellite or from a deep space probe. Possible applications of the technique are discussed.

  17. Lithographically fabricated silicon microreactor for in situ characterization of heterogeneous catalysts—Enabling correlative characterization techniques

    Energy Technology Data Exchange (ETDEWEB)

    Baier, S.; Rochet, A.; Hofmann, G. [Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology, D-76131 Karlsruhe (Germany); Kraut, M. [Institute for Micro Process Engineering, Karlsruhe Institute of Technology, D-76344 Eggenstein-Leopoldshafen (Germany); Grunwaldt, J.-D., E-mail: grunwaldt@kit.edu [Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology, D-76131 Karlsruhe (Germany); Institute of Catalysis Research and Technology, Karlsruhe Institute of Technology, D-76344 Eggenstein-Leopoldshafen (Germany)

    2015-06-15

    We report on a new modular setup on a silicon-based microreactor designed for correlative spectroscopic, scattering, and analytic on-line gas investigations for in situ studies of heterogeneous catalysts. The silicon microreactor allows a combination of synchrotron radiation based techniques (e.g., X-ray diffraction and X-ray absorption spectroscopy) as well as infrared thermography and Raman spectroscopy. Catalytic performance can be determined simultaneously by on-line product analysis using mass spectrometry. We present the design of the reactor, the experimental setup, and as a first example for an in situ study, the catalytic partial oxidation of methane showing the applicability of this reactor for in situ studies.

  18. Laser Based In Situ Techniques: Novel Methods for Generating Extreme Conditions in TEM Samples

    Energy Technology Data Exchange (ETDEWEB)

    Taheri, M; Lagrange, T; Reed, B; Armstrong, M; Campbell, G; DeHope, W; Kim, J; King, W; Masiel, D; Browning, N

    2008-02-25

    The Dynamic Transmission Electron Microscope (DTEM) is introduced as a novel tool for in situ processing of materials. Examples of various types of dynamic studies outline the advantages and differences of laser-based heating in the DTEM in comparison to conventional (resistive) heating in situ TEM methods. We demonstrate various unique capabilities of the drive laser, namely, in situ processing of nanoscale materials, rapid and high temperature phase transformations, and controlled thermal activation of materials. These experiments would otherwise be impossible without the use of the DTEM drive laser. Thus, the potential of the DTEM to as a new technique to process and characterize the growth of a myriad of micro and nanostructures is demonstrated.

  19. Lithographically fabricated silicon microreactor for in situ characterization of heterogeneous catalysts—Enabling correlative characterization techniques

    International Nuclear Information System (INIS)

    We report on a new modular setup on a silicon-based microreactor designed for correlative spectroscopic, scattering, and analytic on-line gas investigations for in situ studies of heterogeneous catalysts. The silicon microreactor allows a combination of synchrotron radiation based techniques (e.g., X-ray diffraction and X-ray absorption spectroscopy) as well as infrared thermography and Raman spectroscopy. Catalytic performance can be determined simultaneously by on-line product analysis using mass spectrometry. We present the design of the reactor, the experimental setup, and as a first example for an in situ study, the catalytic partial oxidation of methane showing the applicability of this reactor for in situ studies

  20. Selective Substitution of 31/42–OH in Rapamycin Guided by an in Situ IR Technique

    Directory of Open Access Journals (Sweden)

    Shuang Cao

    2014-06-01

    Full Text Available An in situ IR technique was applied in the selective synthesis of the key intermediate for rapamycin derivatives, which made the reaction endpoint easily defined. This technology solved a bothersome problem in the preparation of rapamycin derivatives, and based on this technique, the 31-OH and 42-OH of rapamycin were chemically modified by a series of quaternary ammonium salts to generate 11 compounds. The solubility of all these compounds was remarkably improved (25,000 times higher than that of rapamycin and their structures were confirmed by MS, IR, 1D and 2D NMR techniques.

  1. Stability investigations of zinc and cobalt precipitates immobilized by in situ bioprecipitation (ISBP) process.

    Science.gov (United States)

    Satyawali, Yamini; Schols, Edo; Van Roy, Sandra; Dejonghe, Winnie; Diels, Ludo; Vanbroekhoven, Karolien

    2010-09-15

    In situ bioprecipitation (ISBP), which involves immobilizing the metals as precipitates (mainly sulphides) in the solid phase, is an effective method of metal removal from contaminated groundwater. This study investigated the stability of metal precipitates formed after ISBP in two different solid-liquid matrices (artificial and natural). The artificial matrix consisted of sand, Zn (200 mg L(-1)), artificial groundwater and a carbon source (electron donor). Here the stability of the Zn precipitates was evaluated by manipulation of redox and pH. The natural system matrices included aquifer material and groundwater samples collected from three different metal (Zn and Co) contaminated sites and different carbon sources were provided as electron donors. In the natural matrices, metal precipitates stability was assessed by changing aquifer redox conditions, sequential extraction, and BIOMET assay. The results indicated that, in the artificial matrix, redox manipulation did not impact the Zn precipitates. However the sequential pH change proved detrimental, releasing 58% of the precipitated Zn back into liquid phase. In natural matrices, the applied carbon source largely affected the stability of metal precipitates. Elemental analysis performed on the precipitates formed in natural matrix showed that the main elements of the precipitates were sulphur with Zn and Co. PMID:20537795

  2. Fragrance composition of Dendrophylax lindenii (Orchidaceae using a novel technique applied in situ

    Directory of Open Access Journals (Sweden)

    James J. Sadler

    2012-02-01

    Full Text Available The ghost orchid, Dendrophylax lindenii (Lindley Bentham ex Rolfe (Orchidaceae, is one of North America’s rarest and well-known orchids. Native to Cuba and SW Florida where it frequents shaded swamps as an epiphyte, the species has experienced steady decline. Little information exists on D. lindenii’s biology in situ, raising conservation concerns. During the summer of 2009 at an undisclosed population in Collier County, FL, a substantial number (ca. 13 of plants initiated anthesis offering a unique opportunity to study this species in situ. We report a new technique aimed at capturing floral headspace of D. lindenii in situ, and identified volatile compounds using gas chromatography mass spectrometry (GC/MS. All components of the floral scent were identified as terpenoids with the exception of methyl salicylate. The most abundant compound was the sesquiterpene (E,E-?-farnesene (71% followed by (E-?-ocimene (9% and methyl salicylate (8%. Other compounds were: linalool (5%, sabinene (4%, (E-?-bergamotene (2%, ?-pinene (1%, and 3-carene (1%. Interestingly, (E,E-?-farnesene has previously been associated with pestiferous insects (e.g., Hemiptera. The other compounds are common floral scent constituents in other angiosperms suggesting that our in situ technique was effective. Volatile capture was, therefore, possible without imposing physical harm (e.g., inflorescence detachment to this rare orchid.

  3. Comparative review of techniques used for in situ remediation of contaminated soils

    International Nuclear Information System (INIS)

    Soil pollution may influence the geotechnical parameters of the soil itself, properties such as solid particle density or water within its pores. It may also vary its friction angle, modify its structure and texture, or change the properties of its constitutive minerals due to the inclusion of polluting components. For these reasons, soil decontamination is an important factor to consider in geotechnics. This work focuses on those soil decontamination techniques carried out in situ, since they allow to eliminate soil pollutants in a less invasive way than confinement, containment or ex situ remediation techniques, causing a minor soil alteration and, therefore, affecting less to its mechanical properties. These factors should be taken into account when carrying out a geotechnical performance on a previously decontaminated soil. (Author)

  4. Optical techniques for remote and in-situ characterization of particles pertinent to GEOTRACES

    Science.gov (United States)

    Boss, Emmanuel; Guidi, Lionel; Richardson, Mary Jo; Stemmann, Lars; Gardner, Wilford; Bishop, James K. B.; Anderson, Robert F.; Sherrell, Robert M.

    2015-04-01

    Field and laboratory characterization of marine particles is laborious and expensive. Proxies of particle properties have been developed that allow researchers to obtain high frequency distributions of such properties in space or time. We focus on optical techniques used to characterize marine particles in-situ, with a focus on GEOTRACES-relevant properties, such as bulk properties including particle mass, cross-sectional area, particle size distribution, particle shape information, and also single particle optical properties, such as individual particle type and size. We also address the use of optical properties of particles to infer particulate organic or inorganic carbon. In addition to optical sensors we review advances in imaging technology and its use to study marine particles in situ. This review addresses commercially available technology and techniques that can be used as a proxy for particle properties and the associated uncertainties with particular focus to open ocean environments, the focus of GEOTRACES.

  5. Technique for voltage stability assessment using newly developed line voltage stability index

    International Nuclear Information System (INIS)

    This paper presents an efficient technique for voltage stability assessment using a newly developed line voltage stability index that becomes half at a collapse point. Power flow equations have been used to identify critical lines, which may be vulnerable during an increased loading condition. Further, based on the line voltage stability index, a reliable scheme is proposed for protection against voltage collapse. It has been shown that as loading increases, the impedance seen by an impedance relay equals the impedance of the line at the collapse point for the most critical line. This condition has been obtained using the derived line voltage stability index. Hence, the proposed index could be easily implemented in a distant relay, either numerical or electromagnetic. This type of arrangement can give an alarm/tripping signal, indicating that the system has entered into an insecure zone from the voltage collapse viewpoint. The developed concept has been implemented on the standard 25 bus and 57 bus IEEE test systems, and the results have been compared with another proximity indicator known as the minimum eigenvalue of the load flow Jacobian

  6. Grout performance in support of in situ stabilization/solidification of the GAAT tank sludges

    International Nuclear Information System (INIS)

    The Gunite trademark and associated tanks (GAATs) were constructed at ORNL between 1943 and 1951 and were used for many years to collect radioactive and chemical wastes. These tanks are currently inactive. Varying amounts of the sludge were removed and disposed of through the Hydrofracture Program. Thus, some tanks are virtually empty, while others still contain significant amounts of sludge and supernatant. In situ grouting of the sludges in the tanks using multi-point injection (MPI trademark), a patented, proprietary technique, is being investigated as a low-cost alternative to (1) moving the sludges to the Melton Valley Storage Tanks (MVSTs) for later solidification and disposal, (2) ex situ grouting of the sludges followed by either disposal back in the tanks or containerizing and disposal elsewhere, and (3) vitrification of the sludges. The paper discusses the chemical characteristics of the GAATs and the type of chemical surrogate that was used during the leachability tests. This is followed by the experimental work, which, consisted of scope testing and sensitivity testing. The scope testing explored the rheology of the proposed jetting slurries and the settling properties of the proposed grouts using sand-water mixes for the wet sludge. After establishing a jetting slurry and grout with an acceptable rheology and settling properties, the proposed in situ grout formulation was subjected to sensitivity testing for variations in the formulation

  7. On the stability of a variety of organic photovoltaic devices by IPCE and in situ IPCE analyses – the ISOS-3 inter-laboratory collaboration

    DEFF Research Database (Denmark)

    Teran-Escobar, Gerardo; Tanenbaum, David

    2012-01-01

    This work is part of the inter-laboratory collaboration to study the stability of seven distinct sets of state-of-the-art organic photovoltaic (OPV) devices prepared by leading research laboratories. All devices have been shipped to and degraded at RISØ-DTU up to 1830 hours in accordance with established ISOS-3 protocols under defined illumination conditions. In this work, we apply the Incident Photon-to-Electron Conversion Efficiency (IPCE) and the in situ IPCE techniques to determine the relation between solar cell performance and solar cell stability. Different ageing conditions were considered: accelerated full sun simulation, low level indoor fluorescent lighting and dark storage. The devices were also monitored under conditions of ambient and inert (N2) atmospheres, which allows for the identification of the solar cell materials more susceptible to degradation by ambient air (oxygen and moisture). The different OPVs configurations permitted the study of the intrinsic stability of the devices depending on: two different ITO-replacement alternatives, two different hole extraction layers (PEDOT:PSS and MoO3), and two different P3HT-based polymers. The response of un-encapsulated devices to ambient atmosphere offered insight into the importance of moisture in solar cell performance. Our results demonstrate that the IPCE and the in situ IPCE techniques are valuable analytical methods to understand device degradation and solar cell lifetime.

  8. Concrete - Opalinus clay interaction: in-situ experiment and technique for coring undisturbed interfaces

    International Nuclear Information System (INIS)

    Document available in extended abstract form only. Designs for deep geologic disposal of radioactive waste foresee cementitious materials as structural elements, backfill or waste matrix. Interactions near interfaces are driven by chemical gradients in pore water and resultant diffusive transport, and are predicted to lead to mineralogical alterations in the barrier system, which in turn influences properties like swelling pressure, permeability, or specific retention in case of clay materials. Reactive transport modelling predictions and laboratory and in situ studies revealed significant alteration in both cement and clay-stone. An increase in porosity in the cement close to the interface, and clogging in the clay-stone adjacent to the interface is commonly predicted and observed. The Cement-Clay Interaction (CI) Experiment at the Mont Terri Underground Laboratory (St. Ursanne, Switzerland) aims at demonstrating some of the processes at interfaces to be expected at a realistic spatial scale and under saturated conditions. A duration of 20 years is foreseen during which reaction progress should become measurable and thus comparable to laboratory experiments and modelling predictions. Companion studies address cement hydration, and develop new high-resolution techniques for phase identification using ?-X-ray diffraction at the Paul Scherrer Institut. The field experiment at Mont Terri comprises two vertical boreholes (384 mm diameter, up to 9 m length) in Opalinus Clay (OPA) filled with layers of three different concretes and bentonite. The concrete formulations are based on three different binders: Portland cement (OPC), ESDRED cement designed for repository applications (40% of cement substituted by silica fume), and low alkali cement (LAC, containing slag and nano-silica). The characterisation of the three concrete-OPA interfaces after 2 years of alteration are presented in a companion contribution (Jenni et al.). A key issue is the repeat recovery of undisturbed samples of the different interfaces with concrete. A first sampling campaign in 2009 used a simple stabilisation technique with a central anchor rod that was glued in before coring. It was impossible to retrieve completely undisturbed samples. A new technique was developed for the drilling campaign during February 2012, and it was successfully applied in all four sampling boreholes carried out, retrieving a total of 150 kg of core and 10 physically and chemically undisturbed interface samples. The technique comprised intersection drilling at 45 deg. inclination and 220 mm OD to within 50 cm of the vertical concrete pile. The base was reamed planar, and templates were installed to drill a circular arrangement of 6 boreholes with 46 mm OD, three at a time. These small boreholes extended across the entire pile (1.4-1.6 m), and anchor rods made of fibre glass and filled with cement were embedded with epoxy resin. A different template was subsequently used to over-core (131 mm OD / 101 mm core DM, double-barrel, acrylic liner) cutting through the reinforcements. Stabilized composite cores of 1.4-1.6 m length could be retrieved in this manner. (authors)

  9. On the stability of a variety of organic photovoltaic devices by IPCE and in situ IPCE analyses – the ISOS-3 inter-laboratory collaboration

    DEFF Research Database (Denmark)

    Teran-Escobar, Gerardo; Tanenbaum, David; Voroshazi, Eszter; Hermenau, Martin; Norrman, Kion; Lloyd, Matthew T; Galagan, Yulia; Zimmermann, Birger; Hösel, Markus; Dam, Henrik Friis; Jørgensen, Mikkel; Gevorgyan, Suren; Kudret, Suleyman; Maes, Wouter; Lutsen, Laurence; Vanderzande, Dirk; Würfel, Uli; Andriessen, Ronn; Rösch, Roland; Hoppe, Harald; Rivaton, Agnès; Uzunoglu, Gülsah Y.; Germack, David; Andreasen, Birgitta; Vesterager Madsen, Morten; Bundgaard, Eva; Krebs, Frederik C; Lira-Cantu, Monica

    2012-01-01

    This work is part of the inter-laboratory collaboration to study the stability of seven distinct sets of state-of-the-art organic photovoltaic (OPV) devices prepared by leading research laboratories. All devices have been shipped to and degraded at RISØ-DTU up to 1830 hours in accordance with established ISOS-3 protocols under defined illumination conditions. In this work, we apply the Incident Photon-to-Electron Conversion Efficiency (IPCE) and the in situ IPCE techniques to determine the relat...

  10. In situ measurement of the effect of LiOH on the stability of zircaloy-2 surface film in PWR water

    International Nuclear Information System (INIS)

    Surface films on the metals play a major role in corrosion assisted cracking. A new method called Contact Electric Resistance (CER) method has been recently developed for in situ measurement of the electric resistance of surface films in high temperature and high pressure environments. The technique has been used to determine in situ the electric resistance of films on metals when in contact with water and dissolved anions, during formation and destruction of oxides and hydrides and during electroplating of metals. Electric resistance data can be measured with a frequency of the order of one hertz, which makes it possible to investigate in situ the kinetics of surface film related processes which are dependent on the environment, temperature, pH and electrochemical potential. This paper presents the results of the CER investigation on the effects of LiOH on the stability of Zircaloy-2 surface film in water with 2000 ppm H3BO3. At 300 deg. C the LiOH concentrations higher than 10-2 M (roughly 70 ppm of Li+) were found to markedly reduce the electric resistance of the Zircaloy-2 surface film during a test period of less than two hours. The decrease of the film resistance is very abrupt, possibly indicating a phase transformation. Moreover, the advantages of the CER technique over the other competing techniques which rely on the measurement of current are discussed. (author)

  11. SITE PROGRAM APPLICATIONS ANALYSIS REPORT, INTERNATIONAL WASTE TECHNOLOGIES/GEO CON IN-SITU STABILIZATION/SOLIDIFICATION

    Science.gov (United States)

    An evaluation was performed of the International Waste Technologies (IWT) HWT-20 additive and the Geo-Con, Inc. deep-soil-mixing equipment for an in situ stabilization/solidification process and its applicability as an on-site treatment method for waste site cleanup. emonstration...

  12. EPA SITE DEMONSTRATION OF THE INTERNATIONAL WASTE TECHNOLOGIES/GEO-CON IN SITU STABILIZATION/SOLIDIFICATION PROCESS IN HIALEAH, FLORIDA

    Science.gov (United States)

    This paper presents an EPA evaluation of the first field demonstration of an in situ stabilization/solidification process for contaminated soil under the EPA Superfund Innovative Technology Evaluation (SITE) program. emonstration of this process was a joint effort of two vendors:...

  13. In situ cDNA polymerase chain reaction. A novel technique for detecting mRNA expression.

    OpenAIRE

    Chen, R H; Fuggle, S. V.

    1993-01-01

    We report a novel method for detecting intracellular messenger RNA by combining the techniques of in situ hybridization and polymerase chain reaction (PCR) (in situ cDNA PCR). The technique could detect low abundancy signals and distinguish different levels of gene expression. We examined the expression of the functional markers of activated cytotoxic T lymphocytes, granzyme A, and perforin in human lymphocytes from in vitro cultures. The amplification products were found in the cells and the...

  14. Structural stability of SiGe nanoparticles under 'in situ' electron beam irradiation in TEM

    International Nuclear Information System (INIS)

    The structure of amorphous and crystalline SiGe nanoparticles, embedded in a dielectric medium, SiO2, and its stability under 'in situ' electron beam irradiation is reported. High-resolution transmission electron microscopy and electron-diffraction pattern simulation by fast Fourier transform was used to analyze the crystal structure of the SiGe nanoparticles. Electron beam irradiation induces structural alternate order-disorder transitions in the nanoparticles for irradiation effects are mainly associated to the density of current. For irradiation with current densities -2 no effects are observed in the as-deposited amorphous samples, whereas in the crystallized samples, SiGe nanocrystals show higher stability and no effects are observed for irradiation densities of current -2. Irradiation with densities of current greater than these thresholds cause consecutive amorphous-crystalline or crystalline-amorphous structure transitions respectively for both amorphous and crystallized nanoparticles. A hexagonal structure is proposed for those nanocrystals obtained after irradiation in the as deposited amorphous samples.

  15. Implementation of In-Situ Impedance Techniques on a Full Scale Aero-Engine System

    Science.gov (United States)

    Gaeta, R. J.; Mendoza, J. M.; Jones, M. G.

    2007-01-01

    Determination of acoustic liner impedance for jet engine applications remains a challenge for the designer. Although suitable models have been developed that take account of source amplitude and the local flow environment experienced by the liner, experimental validation of these models has been difficult. This is primarily due to the inability of researchers to faithfully mimic the environment in jet engine nacelles in the laboratory. An in-situ measurement technique, one that can be implemented in an actual engine, is desirable so an accurate impedance can be determined for future modeling and quality control. This paper documents the implementation of such a local acoustic impedance measurement technique that is used under controlled laboratory conditions as well as on full scale turbine engine liner test article. The objective for these series of in-situ measurements is to substantiate treatment design, provide understanding of flow effects on installed liner performance, and provide modeling input for fan noise propagation computations. A series of acoustic liner evaluation tests are performed that includes normal incidence tube, grazing incidence tube, and finally testing on a full scale engine on a static test stand. Lab tests were intended to provide insight and guidance for accurately measuring the impedance of the liner housed in the inlet of a Honeywell Tech7000 turbofan. Results have shown that one can acquire very reasonable liner impedance data for a full scale engine under realistic test conditions. Furthermore, higher fidelity results can be obtained by using a three-microphone coherence technique that can enhance signal-to-noise ratio at high engine power settings. This research has also confirmed the limitations of this particular type of in-situ measurement. This is most evident in the installation of instrumentation and its effect on what is being measured.

  16. Measurement techniques for in situ stresses around underground constructions in a deep clay formation

    Directory of Open Access Journals (Sweden)

    Li X.L.

    2010-06-01

    Full Text Available Disposal in deep underground geological formations is internationally recognized as the most viable option for the long-term management of high-level radioactive waste. In Belgium, the Boom clay formation is extensively studied in this context, in particular at the 225 m deep HADES Underground Research Facility in Mol. A cost-effective design of deep underground structures requires an accurate assessment of the in situ stresses; a good estimation of these stresses is also essential when interpreting in situ experiments regarding the hydro-mechanical behaviour of the host formation. Different measurement techniques are available to provide data on the stress evolution and other mechanical properties of the geological formation. The measurement can be direct (measurement of total pressure, or it can be an indirect technique, deriving the stress from related quantities such as strain (changes in structural members. Most total stress measurements are performed through permanently installed sensors; also once-only measurements are performed through specific methods (e.g. pressuremeter. Direct measurement of the stress state is challenging due to the complex mechanical behaviour of the clay, and the fact that the sensor installation inevitably disturbs the original stress field. This paper describes ways to deal with these problems and presents the results obtained using different techniques at HADES.

  17. Development of a fluorescent in situ hybridization (FISH) technique for visualizing CGMMV in plant tissues.

    Science.gov (United States)

    Shargil, D; Zemach, H; Belausov, E; Lachman, O; Kamenetsky, R; Dombrovsky, A

    2015-10-01

    Cucumber green mottle mosaic virus (CGMMV), which belongs to the genus Tobamovirus, is a major pathogen of cucurbit crops grown indoors and in open fields. Currently, immunology (e.g., ELISA) and molecular amplification techniques (e.g., RT-PCR) are employed extensively for virus detection in plant tissues and commercial seed lots diagnostics. In this study, a fluorescent in situ hybridization (FISH) technique, using oligonucleotides whose 5'-terminals were labeled with red cyanine 3 (Cy3) or green fluorescein isothiocyanate (FITC), was developed for the visualization of the pathogen in situ. This simple and reliable method allows detection and localization of CGMMV in the vegetative and reproductive tissues of cucumber and melon. When this technique was applied in male flowers, anther tissues were found to be infected; whereas the pollen grains were found to be virus-free. These results have meaningful epidemiological implications for the management of CGMMV, particularly with regard to virus transfer via seed and the role of insects as CGMMV vectors. PMID:26231788

  18. Measurement techniques for in situ stresses around underground constructions in a deep clay formation

    Science.gov (United States)

    Verstricht, J.; Areias, L.; Bastiaens, W.; Li, X. L.

    2010-06-01

    Disposal in deep underground geological formations is internationally recognized as the most viable option for the long-term management of high-level radioactive waste. In Belgium, the Boom clay formation is extensively studied in this context, in particular at the 225 m deep HADES Underground Research Facility in Mol. A cost-effective design of deep underground structures requires an accurate assessment of the in situ stresses; a good estimation of these stresses is also essential when interpreting in situ experiments regarding the hydro-mechanical behaviour of the host formation. Different measurement techniques are available to provide data on the stress evolution and other mechanical properties of the geological formation. The measurement can be direct (measurement of total pressure), or it can be an indirect technique, deriving the stress from related quantities such as strain (changes) in structural members. Most total stress measurements are performed through permanently installed sensors; also once-only measurements are performed through specific methods (e.g. pressuremeter). Direct measurement of the stress state is challenging due to the complex mechanical behaviour of the clay, and the fact that the sensor installation inevitably disturbs the original stress field. This paper describes ways to deal with these problems and presents the results obtained using different techniques at HADES.

  19. Sintering process optimization for multi-layer CGO membranes by in situ techniques

    DEFF Research Database (Denmark)

    Kaiser, Andreas; Prasad, A.S.; Foghmoes, Søren Preben Vagn; Ramousse, Severine; Bonanos, Nikolaos; Esposito, Vincenzo

    2013-01-01

    The sintering of asymmetric CGO bi-layers (thin dense membrane on a porous support; Ce0.9Gd0.1O1.95-delta = CGO) with Co3O4 as sintering additive has been optimized by combination of two in situ techniques. Optical dilatometry revealed that bi-layer shape and microstructure are dramatically changing in a narrow temperature range of less than 100 degrees C. Below 1030 degrees C, a higher densification rate in the dense membrane layer than in the porous support leads to concave shape, whereas the ...

  20. Radioactive tracer technique for the in-situ investigation of corrosion and contamination processes

    International Nuclear Information System (INIS)

    A new tracer technique and a measuring system consisting of electrochemical and nuclear measuring units were developed for the in-situ investigation of corrosion and contamination processes. The adsorption of sulfate ions labelled with sulfur 35 on the powdered surface of austenitic steel 08X18H10T was studied. The kinetics of the sorption, the effect of Na2CrO4 and the electrode potential were studied. It can be stated that the Cr3+ containing species of the oxide layer play an important role in the selective equilibrium sorption. (V.N.) 20 refs.; 12 figs

  1. Thermo-stabilized, porous polyimide microspheres prepared from nanosized SiO2 templating via in situ polymerization

    Directory of Open Access Journals (Sweden)

    M. Q. Liu

    2015-01-01

    Full Text Available In this article, we addressed a feasible and versatile method of the fabrication of porous polyimide microspheres presenting excellent heat resistance. The preparation process consisted of two steps. Firstly, a novel polyimide/nano-silica composite microsphere was prepared via the self-assembly structures of poly(amic acid (PAA, precursor of PI/nanosized SiO2 blends after in situ polymerization, following the two-steps imidization. Subsequently, the encapsulated nanoparticles were etched away by hydrofluoric acid treatment, giving rise to the pores. It is found the composite structure of PI/SiO2 is a precondition of the formation of nanoporous structures, furthermore, the morphology of the resultant pore could be relatively tuned by changing the content and initial morphology of silica nano-particles trapped into PI matrix. The thermal properties of the synthesized PI porous spheres were studied, indicating that the introduction of nanopores could not effectively influence the thermal stabilities of PI microspheres. Moreover, the fabrication technique described here may be extended to other porous polymer systems.

  2. In situ Mechanistic Investigation of an Organic Radical Polymer Cathode on Interfacial Charge Transport and Cycling Stability

    Science.gov (United States)

    Li, Fei; Lutkenhaus, Jodie

    2015-03-01

    Organic radical polymers have gained increased attention as cathodes for organic radical batteries due to their fast charge transport and high cycling stability. These features make them a promising alternative to conventional lithium-ion batteries. One polymer of interest is a nitroxide radical polymer, poly(2,2,6,6-tetramethylpiperidinyloxymethacrylate) (PTMA), which is capable of a two-electron transfer process. The specific capacity of PTMA as cathode has a reported value between 77 to 220 mAh/g, depending on the charge/discharge conditions. Most work with PTMA has largely emphasized electrode optimization to improve its capacity by adding highly conductive materials or by designing new forms of radical polymers. There is little molecular level detail on the charge storage process and electrode/electrolyte interfacial activities in such systems. Here, we present the application of in situ characterization techniques towards the charge storage process in PTMA. Electrochemical quartz crystal microbalance with dissipation monitoring (EQCM-D) monitors various electrode physical properties (e.g. mass, shear viscosity) during controlled electrochemical interrogation (cyclic voltammetry, charge discharge). Electrochemical impedance spectroscopy probes various charge storage and transport events at a range of frequencies and potentials. With this information attained, a clearer picture of charge storage in organic radical battery cathodes can be formed.

  3. In situ tagging technique for fishes provides insight into growth and movement of invasive lionfish.

    Science.gov (United States)

    Akins, John L; Morris, James A; Green, Stephanie J

    2014-10-01

    Information on fish movement and growth is primarily obtained through the marking and tracking of individuals with external tags, which are usually affixed to anesthetized individuals at the surface. However, the quantity and quality of data obtained by this method is often limited by small sample sizes owing to the time associated with the tagging process, high rates of tagging-related mortality, and displacement of tagged individuals from the initial capture location. To address these issues, we describe a technique for applying external streamer and dart tags in situ, which uses SCUBA divers to capture and tag individual fish on the sea floor without the use of anesthetic. We demonstrate this method for Indo-Pacific lionfish (Pterois volitans/P. miles), species which are particularly vulnerable to barotrauma when transported to and handled at the surface. To test our method, we tagged 161 individuals inhabiting 26 coral reef locations in the Bahamas over a period of 3 years. Our method resulted in no instances of barotrauma, reduced handling and recovery time, and minimal post-tagging release displacement compared with conventional ex situ tag application. Opportunistic resighting and recapture of tagged individuals reveals that lionfish exhibit highly variable site fidelity, movement patterns, and growth rates on invaded coral reef habitats. In total, 24% of lionfish were resighted between 29 and 188 days after tagging. Of these, 90% were located at the site of capture, while the remaining individuals were resighted between 200 m and 1.1 km from initial site of capture over 29 days later. In situ growth rates ranged between 0.1 and 0.6 mm/day. While individuals tagged with streamer tags posted slower growth rates with increasing size, as expected, there was no relationship between growth rate and fish size for individuals marked with dart tags, potentially because of large effects of tag presence on the activities of small bodied lionfish (i.e., <150 mm), where the tag was up to 7.6% of the lionfish's mass. Our study offers a novel in situ tagging technique that can be used to provide critical information on fish site fidelity, movement patterns, and growth in cases where ex situ tagging is not feasible. PMID:25614791

  4. Técnicas in situ de baixo custo em eletroquímica: a microbalança a cristal de quartzo Low cost in situ techniques in electrochemistry: the quartz crystal microbalance

    OpenAIRE

    Hamilton Varela; Marcos Malta; Torresi, Roberto M.

    2000-01-01

    Among in situ techniques, the electrochemical quartz crystal microbalance (EQCM) is a powerful tool for the study of electrochemical reactions that produce mass changes in the electrode/solution interface. This review present some systems in which the EQCM combined with classical electrochemical techniques, gives relevant information for understanding the charge transport process at a molecular level. The aim of this review is to do a brief description of experimental arrangements, with empha...

  5. Lab scale testing of novel natural analog in situ stabilization agents

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, P. [Lockheed Martin Idaho Technology Co., Idaho Falls, ID (United States)

    1997-12-31

    This report summarizes the laboratory-scale test results on several novel in situ treatment and stabilization agents for buried hazardous and radioactive waste. Paraffin, hematite and phosphate materials were examined when combined with soil and other wastes representative of what might be present at buried waste DOE sites. Hematite was made from the reaction of agricultural iron and lime slurries to form gypsum and iron oxide/hydroxide. Common household paraffin was melted, both with and without a zeolitic additive, waste added and then cooled. Magnesium phosphate was made from the reaction of magnesium oxide and phosphoric acid or potassium biphosphate to form, magnesium phosphate. All were tested with soil and some with additional waste sumulants such as ash, machine oil and nitrate salts. The following laboratory-generated data indicate that all waste encapsulation materials tested are appropriate materials, for field in situ testing. Compressive strengths of treated Idaho National Engineering and Environment Laboratory (INEEL) soil and the waste encapsulation material were sufficient to prevent collapse of the void space in waste, i.e., greater than the NRC 60 psi minimum. The mineralogy and microstructure of hematite was amorphous but should progress to an interlocking crystalline solid. Phosphate was crystalline with characteristics of higher temperature ceramics. Paraffin is non crystalline but encapsulates even very fine grained INEEL soils. Each agent appears to be chemically and physically inert to possible waste materials such as, nitrates and machine cutting oil. Two of the agents hematite and phosphate react favorably with ash increasing the metals retention at higher waste loadings than Portland cement. Hematite, phosphate and zeolite decrease leaching of most hazardous metals from waste when compared to untreated waste and soil. Solution pH, time for reaction initiation, and viscosity values are conducive to jet-grouting application.

  6. Lab scale testing of novel natural analog in situ stabilization agents

    International Nuclear Information System (INIS)

    This report summarizes the laboratory-scale test results on several novel in situ treatment and stabilization agents for buried hazardous and radioactive waste. Paraffin, hematite and phosphate materials were examined when combined with soil and other wastes representative of what might be present at buried waste DOE sites. Hematite was made from the reaction of agricultural iron and lime slurries to form gypsum and iron oxide/hydroxide. Common household paraffin was melted, both with and without a zeolitic additive, waste added and then cooled. Magnesium phosphate was made from the reaction of magnesium oxide and phosphoric acid or potassium biphosphate to form, magnesium phosphate. All were tested with soil and some with additional waste sumulants such as ash, machine oil and nitrate salts. The following laboratory-generated data indicate that all waste encapsulation materials tested are appropriate materials, for field in situ testing. Compressive strengths of treated Idaho National Engineering and Environment Laboratory (INEEL) soil and the waste encapsulation material were sufficient to prevent collapse of the void space in waste, i.e., greater than the NRC 60 psi minimum. The mineralogy and microstructure of hematite was amorphous but should progress to an interlocking crystalline solid. Phosphate was crystalline with characteristics of higher temperature ceramics. Paraffin is non crystalline but encapsulates even very fine grained INEEL soils. Each agent appears to be chemically and physically inert to possible waste materials such as, nitrates and machine cutting oil. Two of the agents hematite and phosphate react favorably with ash increasing the metals retention at higher waste loadings than Portland cement. Hematite, phosphate and zeolite decrease leaching of most hazardous metals from waste when compared to untreated waste and soil. Solution pH, time for reaction initiation, and viscosity values are conducive to jet-grouting application

  7. A Review of Voltage Stability Assessment Techniques with an Improved Voltage Stability Indicator

    Science.gov (United States)

    Danish, Mir Sayed Shah; Yona, Atsushi; Senjyu, Tomonobu

    2015-04-01

    A blackout can take place in entire power system or a part of the system due to extreme voltage instability (voltage collapse) that can appear abruptly. Instability prediction and continuous monitoring of the power system performance is, therefore, known exigent. This paper is conducted with a broad overview of the voltage stability indices, which are previously studied in the literature, and have the same foundation during their formulation. Afterward, an improved voltage stability indicator is introduced as a result of the multi-criteria integration and enhancement of the original indices by employing linear algebra methods. It is found that the proposed algorithm can overcome on the probable limitations from calculating point view. Then comparative analysis of the indices is presented in order to reach a unique consensus about the typical techniques of modal analysis (sensitivity, eigenvalue, right eigenvectors, and bus participation factor) as a precise algorithm. Finally, the IEEE 14-bus, and 30-bus test systems are selected to verify the algorithm, and compare the performance of the improved indicator approach with the existing indices.

  8. Californium-252 in situ activation and photon detection techniques for uranium ore deposit evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Brodzinski, R.L.; Wogman, N.A.

    1976-01-01

    Four different techniques are evaluated for borehole analysis of uranium and thorium ores. Methods involving (1) detection of fission product photons following /sup 252/Cf activation, (2) detection of low-energy uranium and thorium gamma-rays, (3) direct measurement of the 1001-keV photon from /sup 234m/Pa, a progeny of /sup 238/U, and (4) isotopic excitation x-ray fluorescence spectroscopy are evaluated. The first two techniques are found too unsuitable for most low grade ores. The third is found to be suitable for the in-situ analysis of uranium ores only, and the fourth method is shown to be a superior, cost effective method for both uranium and thorium ore analysis.

  9. A Novel FCC Catalyst Based on a Porous Composite Material Synthesized via an In Situ Technique

    Directory of Open Access Journals (Sweden)

    Shu-Qin Zheng

    2015-11-01

    Full Text Available To overcome diffusion limitations and improve transport in microporous zeolite, the materials with a wide-pore structure have been developed. In this paper, composite microspheres with hierarchical porous structure were synthesized by an in situ technique using sepiolite, kaolin and pseudoboehmite as raw material. A novel fluid catalytic cracking (FCC catalyst for maximizing light oil yield was prepared based on the composite materials. The catalyst was characterized by XRD, FT-IR, SEM, nitrogen adsorption-desorption techniques and tested in a bench FCC unit. The results indicated that the catalyst had more meso- and macropores and more acid sites than the reference catalyst, and thus can increase light oil yield by 1.31 %, while exhibiting better gasoline and coke selectivity.

  10. Detection of human papilloma virus (HPV) genomes by the primed in situ (PRINS) labelling technique.

    Science.gov (United States)

    Ramael, M; Van Steelandt, H; Stuyven, G; Van Steenkiste, M; Degroote, J

    1999-01-01

    Primed in situ Labelling, a technique based on primer mediated DNA synthesis, has become a useful tool in cytogenetics, especially for chromosome mapping, banding and the investigation of sequence organization in fresh metaphase preparations. Its application in the routine surgical pathology laboratory has been hampered by the fact that the technique did not work on paraffin-embedded, formalin-fixed tissue. We investigated cervical biopsies (n = 20) with morphological signs of HPV infection and found that the PRINS method is at least as sensitive as a classical in situ hybridization assay for detecting HPV DNA in paraffin-embedded, formalin-fixed tissue. In all investigated cases (n = 20), HPV DNA was found by both methods. The PRINS method was able to demonstrate HPV DNA not only in superficial koilocytotic squamous cells but also in non-koilocytotic cells in the deeper spinous cell layers, and even in some basal cells. We describe an economical protocol using conventional consensus HPV oligonucleotide DNA primers. The described method is rapid (approximately 3 hours) and easy to perform for screening and subtyping HPV infection in the routine surgical pathology laboratory. PMID:10631714

  11. Development of Advanced In-Situ Techniques for Chemistry Monitoring and Corrosion Mitigation in SCWO Environments

    Energy Technology Data Exchange (ETDEWEB)

    Macdonald, D. D.; Lvov, S. N.

    2000-03-31

    This project is developing sensing technologies and corrosion monitoring techniques for use in super critical water oxidation (SCWO) systems to reduce the volume of mixed low-level nuclear waste by oxidizing organic components in a closed cycle system where CO2 and other gaseous oxides are produced, leaving the radioactive elements concentrated in ash. The technique uses water at supercritical temperatures under highly oxidized conditions by maintaining a high fugacity of molecular oxygen in the system, which causes high corrosion rates of even the most corrosive resistant reactor materials. This project significantly addresses the high corrosion shortcoming through development of (a) advanced electrodes and sensors for in situ potentiometric monitoring of pH in high subcritical and supercritical aqueous solutions, (b) an approach for evaluating the association constants for 1-1 aqueous electrolytes using a flow-through electrochemical thermocell; (c) an electrochemical noise sensor for the in situ measurement of corrosion rate in subcritical and supercritical aqueous systems; (d) a model for estimating the effect of pressure on reaction rates, including corrosion reactions, in high subcritical and supercritical aqueous systems. The project achieved all objectives, except for installing some of the sensors into a fully operating SCWO system.

  12. An in situ high voltage electron microscopy technique for the study of deformation and fracture: In multilayered materials

    Energy Technology Data Exchange (ETDEWEB)

    Wall, M.A.; Barbee, T.W. Jr.; Weihs, T.P. [Lawrence Livermore National Lab., CA (United States). Chemistry and Materials Science Dept.

    1995-04-14

    A novel, in situ, high voltage electron microscopy technique for the direct observation of the micromechanisms of tensile deformation and fracture in nanostructured materials is detailed. This technique is particularly well suited for the dynamic observations of deformation and fracture in multilayered materials. The success of this type of in situ technique is highly dependent upon unique specimen preparation procedures and sample design, the importance thereof will be discussed. The initial observations discussed here are expected to aid in the understanding of the mechanical behavior of this new class of atomically engineered materials.

  13. Field application of innovative grouting agents for in situ stabilization of buried waste sites

    Energy Technology Data Exchange (ETDEWEB)

    Loomis, G.G.; Farnsworth, R.K. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1997-12-31

    This paper presents field applications for two innovative grouting agents that were used to in situ stabilize buried waste sites, via jet grouting. The two grouting agents include paraffin and a proprietary iron oxide based cement grout called TECT. These materials were tested in specially designed cold test pits that simulate buried transuranic waste at the Idaho National Engineering Laboratory (INEL). The field demonstrations were performed at the INEL in an area referred to as the Cold Test Pit, which is adjacent to the INEL Radioactive Waste Management Complex (RWMC). At the RWMC, 56,000 m{sup 3} of transuranic (TRU) waste is co-mingled with over 170,000 m{sup 3} of soil in shallow land burial. Improving the confinement of this waste is one of the options for final disposition of this waste. Using jet-grouting technology to inject these materials into the pore spaces of buried waste sites results in the creation of buried monolithic waste forms that simultaneously protect the waste from subsidence, while eliminating the migratory potential of hazardous and radioactive contaminants in the waste.

  14. In situ vitrification demonstration for the stabilization of buried wastes at the Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    A demonstration of In Situ Vitrification (ISV) technology for the stabilization of radioactively contaminated soil sites at the Oak Ridge National Laboratory (ORNL) was successfully completed during July 1987. This demonstration is the first application of the ISV process not performed at the Hanford Site, where the technology was developed. The joint ORNL-PNL pilot-scale demonstration was performed on a 3/8-scale trench (2 m deep x 1 m wide x 10 m long) that was constructed to simulate a typical seepage trench used for liquid low-level radioactive waste disposal at ORNL from 1951 to 1966. In the ISV process, electrodes are inserted around a volume of contaminated soil, power is applied to the electrodes, and the entire mass is melted from the surface of the soil down through the contaminated zone, thus making a glassy-to-microcrystalline waste form that incorporates the contaminants. Gases produced during the melting are collected, treated, monitored, and released through an off-gas process trailer. In the ORNL demonstration, a 25-t mass of melted rock approximately 1.2 m thick x 2.1 m wide x 4.9 m long was formed during 110 h of operation that consumed approximately 29 MWh of power. Data obtained on the operational performance of the test and waste-form durability will be used to assess the feasibility of applying the ISV technology to an actual waste trench

  15. Non-radioactive TEM in situ-PCR Techniques Applied to the Detection of Pollen Allergen mRNAs

    OpenAIRE

    Alché Ramírez, Juan de Dios; Castro López, Antonio Jesús; Rodrigo Castro, María Isabel

    2003-01-01

    In this chapter we describe the application of an in situ RT-PCR technique to study the localization of allergen transcripts in the pollen grain of olive tree at the ultrastructural level. By means of this method digoxigenin-labeled UTP is incorporated after in situ PCR amplification of a cDNA which is also produced in situ by reverse transcription of mRNA. This method is combined with the fast and sensitive immunogold-(silver) detection system allowing demonstration of the mRNA l...

  16. 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.

  17. Improved thermal stability of exchange bias of Mn-Ir/Co-Fe bilayers by novel in situ thermal annealing procedure

    International Nuclear Information System (INIS)

    The effect of in situ thermal annealing of Mn-Ir films under ultra-high vacuum on the metallurgical microstructure and on the thermal stability of the unidirectional anisotropy constant, JK, was investigated for Mn73Ir27/Co70Fe30 bilayers. As a result, we found that the average lateral grain size of Mn-Ir increases with increasing the in situ annealing temperature, TIR and that the shape of JK-T curve changes to convex with increasing the TIR, implying a narrowing distribution of local blocking temperature. We conclude that ultra-high vacuum annealing is effective in improving the thermal stability of the exchange anisotropy of Mn-Ir/Co-Fe bilayers through the change of lateral grain size distribution of the Mn-Ir layer

  18. Sintering process optimization for multi-layer CGO membranes by in situ techniques

    DEFF Research Database (Denmark)

    Kaiser, Andreas; Prasad, A.S.

    2013-01-01

    The sintering of asymmetric CGO bi-layers (thin dense membrane on a porous support; Ce0.9Gd0.1O1.95-delta = CGO) with Co3O4 as sintering additive has been optimized by combination of two in situ techniques. Optical dilatometry revealed that bi-layer shape and microstructure are dramatically changing in a narrow temperature range of less than 100 degrees C. Below 1030 degrees C, a higher densification rate in the dense membrane layer than in the porous support leads to concave shape, whereas the densification rate of the support is dominant above 1030 degrees C, leading to convex shape. A fiat bi-layer could be prepared at 1030 degrees C, when shrinkage rates were similar. In situ van der Pauw measurements on tape cast layers during sintering allowed following the conductivity during sintering. A strong increase in conductivity and in activation energy E-a for conduction was observed between 900 and 1030 degrees C indicating an activation of the reactive sintering process and phase transformation of cobalt oxide. (C) 2012 Elsevier Ltd. All rights reserved.

  19. Comparative review of techniques used for in situ remediation of contaminated soils; Revision comparativa de tecnicas empleadas para la descontaminacion in situ de suelos contaminados

    Energy Technology Data Exchange (ETDEWEB)

    Escusol Tomey, M.; Rodriguez Abad, R.

    2014-07-01

    Soil pollution may influence the geotechnical parameters of the soil itself, properties such as solid particle density or water within its pores. It may also vary its friction angle, modify its structure and texture, or change the properties of its constitutive minerals due to the inclusion of polluting components. For these reasons, soil decontamination is an important factor to consider in geotechnics. This work focuses on those soil decontamination techniques carried out in situ, since they allow to eliminate soil pollutants in a less invasive way than confinement, containment or ex situ remediation techniques, causing a minor soil alteration and, therefore, affecting less to its mechanical properties. These factors should be taken into account when carrying out a geotechnical performance on a previously decontaminated soil. (Author)

  20. In situ growth of high temperature superconductor thin films with evaporation techniques using an ozone jet

    International Nuclear Information System (INIS)

    This paper reports on high quality YBa2Cu3O7 thin films grown in situ on various substrates (SrTiO3, Al2O3, Si) using MBE techniques and an ozone jet. The yttrium and copper are evaporated from electron gun sources and the barium is evaporated from a Knudsen cell. All sources are controlled by a single mass spectrometer feedback system to obtain the correct fluxes at high partial ozone pressures. During deposition the partial ozone pressure at the substrate position is estimated to be 10-3-10-2 mbar. The substrate holder temperature is 700 degrees C. The real substrate temperature is estimated to be lower than 650 degrees C. The films are analyzed with R(T), X-ray diffraction and RBS measurements. SEM photographs are taken of the surface

  1. Development of experimental in-situ Pu monitoring system based on passive gamma spectroscopy technique

    International Nuclear Information System (INIS)

    To meet the requirements of in-situ 239Pu monitoring at various stages of fuel reprocessing for NRB, an indigenous Pu monitoring system is developed by Electronics Division, BARC. The system is based on passive gamma spectroscopy technique and utilizes an advanced scintillation detector along-with compact spectroscopy hardware. The system hardware and application software have been installed at Control Lab, PREFRE-2, Tarapur for testing and evaluation. Quantification accuracy of better than 10% is achieved during the initial phase of evaluation. The system is targeted for quantification of Pu in samples drawn from Pu purification cycles with operational frequency of 3-5 samples in Round-The-Clock shifts. The system will significantly minimize manual handling of Pu samples in comparison with the existing methods. (author)

  2. Combustion synthesis of advanced materials. [using in-situ infiltration technique

    Science.gov (United States)

    Moore, J. J.; Feng, H. J.; Perkins, N.; Readey, D. W.

    1992-01-01

    The combustion synthesis of ceramic-metal composites using an in-situ liquid infiltration technique is described. The effect of varying the reactants and their stoichiometry to provide a range of reactant and product species i.e. solids, liquids and gases, with varying physical properties e.g. thermal conductivity, on the microstructure and morphology of synthesized products is also described. Alternatively, conducting the combustion synthesis reaction in a reactive gas environment is also discussed, in which advantages can be gained from the synergistic effects of combustion synthesis and vapor phase transport. In each case, the effect of the presence or absence of gravity (density) driven fluid flow and vapor transport is discussed as is the potential for producing new and perhaps unique materials by conducting these SHS reactions under microgravity conditions.

  3. Assessment of phytoremediation as an in-situ technique for cleaning oil-contaminated sites

    International Nuclear Information System (INIS)

    Literature on examples of phytoremediation techniques used in the in-situ remediation of soils contaminated by petroleum hydrocarbons is reviewed. The review includes discussion of the key mechanisms involved in each case, benefits, limitations and costs compared to alternative approaches, including natural attenuation, engineering and bioremediation. Review of the literature led to the conclusion that phytoremediation is an effective method for degrading and containing petroleum hydrocarbons in soil, and confirmed the ability of plants to transfer volatile petroleum hydrocarbons, such as napthalene, from the soil to the atmosphere via transpiration. The primary loss mechanism for the degradation of petroleum hydrocarbons appears to be microorganisms in the rhizosphere of plants. The available information also suggests that plants may degrade petroleum hydrocarbons directly, although the indirect role played by plants is far more common. These roles include supplying root exudates for microbial use, releasing root-associated enzymes that degrade contaminants in the soil, and altering soil to promote phytoremediation. BTEX compounds are most easily amenable to phytoremediation; large and lipophilic compounds such as four or five-ring polyaromatic hydrocarbons are more difficult to remediate. The limited information available suggests that phytoremediation is slightly less expensive than bioremediation, and several order of magnitude less than engineering techniques. In general, phytoremediation is faster than natural attenuation, but typically slower than engineering and bioremediation. On the other hand, it is less disruptive to the site than ex-situ engineering and bioremediation that involve excavation efforts. Phytoremediation is most effective with shallow contamination. Preliminary screenings indicate that there are several plant species, native and introduced, that may be used with some success for phytoremediation in the Prairie and Boreal Plains ecozones. The report includes a glossary and appendices listing types and behaviour of petroleum hydrocarbons, potential applications of phytoremediation in western Canada, and sources of information on phytoremediation on the Internet. 151 refs., tabs., figs

  4. Robust design of decentralized power system stabilizers using meta-heuristic optimization techniques for multimachine systems

    Directory of Open Access Journals (Sweden)

    Jeevanandham Arumugam

    2009-01-01

    Full Text Available In this paper a classical lead-lag power system stabilizer is used for demonstration. The stabilizer parameters are selected in such a manner to damp the rotor oscillations. The problem of selecting the stabilizer parameters is converted to a simple optimization problem with an eigen value based objective function and it is proposed to employ simulated annealing and particle swarm optimization for solving the optimization problem. The objective function allows the selection of the stabilizer parameters to optimally place the closed-loop eigen values in the left hand side of the complex s-plane. The single machine connected to infinite bus system and 10-machine 39-bus system are considered for this study. The effectiveness of the stabilizer tuned using the best technique, in enhancing the stability of power system. Stability is confirmed through eigen value analysis and simulation results and suitable heuristic technique will be selected for the best performance of the system.

  5. Viscous, resistive magnetohydrodynamic stability computed by spectral techniques

    International Nuclear Information System (INIS)

    Expansions in Chebyshev polynomials are used to study the linear stability of one-dimensional magnetohydrodynamic quasiequilibria, in the presence of finite resistivity and viscosity. The method is modeled on the one used by Orszag in accurate computation of solutions of the Orr-Sommerfeld equation. Two Reynolds-like numbers involving Alfven speeds, length scales, kinematic viscosity, and magnetic diffusivity govern the stability boundaries, which are determined by the geometric mean of the two Reynolds-like numbers. Marginal stability curves, growth rates versus Reynolds-like numbers, and growth rates versus parallel wave numbers are exhibited. A numerical result that appears general is that instability has been found to be associated with inflection points in the current profile, though no general analytical proof has emerged. It is possible that nonlinear subcritical three-dimensional instabilities may exist, similar to those in Poiseuille and Couette flow

  6. Consideration on the restoring plan in the subsidence prone areas through the development of ground stability assessment techniques

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, K.S.; Kim, I.H.; Cho, W.J.; Song, W.K.; Synn, J.H.; Choi, S.O.; Yoon, C.H.; Hong, K.P.; Park, C. [Korea Institute of Geology Mining and Materials, Taejon (Korea)

    1998-12-01

    The ground stability assessment technique of the subsidence prone area and its restoring plan need to be developed to obtain the ground stability around the mines at rest or closed since 1980's. Up to the present, the assessment of the subsidence risk has been conducted only after the statements of residents or the observation of symptom on the subsidence. Generally, the assessment process at first stage is carried on through the analysis of surface and mining map, the geological survey and the interviews to the residents. Drilling survey, rock property test, geotechnical rock and ground survey, and numerical analyses belong to the second stage. After the completion of the procedure the stability of buildings and the strength of subsidence are determined. The acquisition of the accurate in-situ data, the estimation of mechanical property of rock mass, and the analysis of basic mechanism may affect in the great extent on the assessment of the subsidence risk. In this study, the development of the subsidence risk assessment method was incorporated with the GIS technique which will be used to make the risk information map on the subsidence. The numerical analysis in 2D and 3D using PFC and FLAC has been conducted to estimate the ground stability of Moo-Geuk Mine area. The displacement behavior of the ground and the development of the failed zone due to the cavity were studied from the numerical modelling. The result of the ground stability assessment for the area in question shows that the risk to the subsidence is relatively small. It is, however, necessary to fill the cavity with some suitable materials when considering the new construction of buildings or roads in plan. Finally, the measures to prevent the subsidence and some case studies were presented, in particular the case study on the measurement of the ground movement in a mine were described in detail. (author). 27 refs., 27 tabs., 62 figs.

  7. Review of in situ tokamak detritiation techniques: current status and remaining open issues before ITER implementation

    International Nuclear Information System (INIS)

    The in vessel tritium inventory control is one of the most ITER challenging issues which has to be performed to fulfil safety requirements. This is due mainly to the presence of Carbon as a constituent of Plasma Facing Material (PFM) which leads to a high fuel permanent retention. For several years now, physics studies and technological developments have been undertaken worldwide in order to develop reliable techniques which could be used in ITER severe environment (Magnetic field, vacuum, high temperature) for in situ tritium recovery. The scope of this presentation is to review the present status of these achievements and define the remaining work to be done in order to propose a dedicated work program. A brief description of the major results observed in tokamak concerning erosion, particle transport et redeposition of wall constituents will be first presented. We will also focus on fuel trapping in the PFM and co deposited layer with a special insight of results obtained during tokamak long pulse operation. A particular attention will be devoted to the observed properties of mixed material as beryllium Carbide and on the expected consequences on material treatment. From these results, an extrapolation to the ITER operation constraints will be crudely established. The different treatment techniques currently used in fusion devices will be then reviewed from usual conditioning procedures as Glow discharge to radio frequency or tokamak plasma assisted techniques. In the frame of ITER, they will be compared in term of fuel removal efficiency. The capability of treating complex surfaces as voids or castellated structure as well as remote area will be also addressed. The necessity to use additional in situ surface treatments in order to maintain tritium inventory under safety limits will be addressed. These treatments mainly based on photo-cleaning (flash lamp or laser) or oxidation will be reviewed in term of possible consequences on plasma operation and of expected technological problem. Ad last, a work program which has to be undertaken in term of fusion technology developments in order to fulfil ITER requirements on PFC treatments will be presented. (author)

  8. Measurement of in-situ stress in salt and rock using NQR techniques

    International Nuclear Information System (INIS)

    A discussion of how stress and strain affect the quantities which can be measured in an NQR experiment shows that, for stresses of the magnitude to be expected at depths up to about 10,000 feet, quadrupole coupling constants will fall in the range of 1 to 10 kHz for both the sodium and chloride ions in NaCl. The most promising system involves pulsed nuclear double resonance detection; and alterative is to observe the quadrupolar splitting of the NMR signal. Choices to be made in the measurement and mapping techniques are discussed. The well-known perturbation of the homogenous stress field in the neighborhood of a borehole is shown to be advantageous from the point of view of obtaining directional information on the stress. Construction and operation of a borehole stress sensor are considered. The NQR technique seems feasible for measuring the magnitude and direction of underground stress with a resolution of about 25 psi, or 2.5% at 1000 psi. Downhole instrumentation suitable for in-situ determinations of stress appears within the state of the art. Additional tasks required on the project are identified

  9. In-situ simultaneous measurement of temperature and thin film thickness with ultrasonic techniques

    Science.gov (United States)

    Khuri-Yakub, Butrus T.; Pei, Jun; Degertekin, F. Levent; Saraswat, Krishna C.

    1996-11-01

    We describe a novel technique to measure in situ, simultaneously, temperature and thin film thickness during semiconductor processing. The measurement is based on the principle that the velocity of an ultrasonic Lamb wave propagating in a silicon wafer is a function of both the wafer temperature and the thin film coating on the wafer surface. Because sensitivities of Lamb wave velocity to temperature and film thickness change differently with frequency, with a simple linear inversion method, we are able to obtain both the processing temperature an film thickness simultaneously with two sets of sensors operating at two distinct frequencies, 0.5MHz and 1.5MHz. This technique is demonstrated in an aluminum sputtering system. We have achieved a temperature measurement accuracy of +/- 0.15 degree C and an aluminum film thickness resolution of +/- 170 angstrom. The measurement does not depend on the optical or the electrical properties of either the wafer or the film materials, and is insensitive to the processing environment. With its high measurement accuracy and setup simplicity, this sensor system carries great potential in semiconductor process monitoring and control.

  10. Measurement of in-situ stress in salt and rock using NQR techniques

    Energy Technology Data Exchange (ETDEWEB)

    Schempp, E.; Hirschfeld, T.; Klainer, S.

    1980-12-01

    A discussion of how stress and strain affect the quantities which can be measured in an NQR experiment shows that, for stresses of the magnitude to be expected at depths up to about 10,000 feet, quadrupole coupling constants will fall in the range of 1 to 10 kHz for both the sodium and chloride ions in NaCl. The most promising system involves pulsed nuclear double resonance detection; and alterative is to observe the quadrupolar splitting of the NMR signal. Choices to be made in the measurement and mapping techniques are discussed. The well-known perturbation of the homogenous stress field in the neighborhood of a borehole is shown to be advantageous from the point of view of obtaining directional information on the stress. Construction and operation of a borehole stress sensor are considered. The NQR technique seems feasible for measuring the magnitude and direction of underground stress with a resolution of about 25 psi, or 2.5% at 1000 psi. Downhole instrumentation suitable for in-situ determinations of stress appears within the state of the art. Additional tasks required on the project are identified.

  11. Pilot demonstration for containment using in situ soil mixing techniques at a chemical disposal superfund site

    International Nuclear Information System (INIS)

    Kiber Environmental Services, Inc. (Kiber), under contract to McLaren-Hart Corporation and the site PRP group, performed technical oversight and on-site sampling and analyses at the confidential site located in Texas. The site consists of 15,000 cubic meters (20,000 cubic yards) of contaminated materials that were to be solidified on-site. The contaminants included heavy metals, PAHs, oil and grease, and volatile organics. Groundwater is less than 1 meter from the surface. Kiber was retained after several unsuccessful efforts to find on-site containment methods that effectively solidified the waste pits while achieving the performance goals. The PRP group then contracted with Kiber to perform the treatability and pilot oversight studies. The full-scale pilot demonstration was performed by Geo-Con. Pilot-scale treatment was performed to evaluate the effectiveness of in situ solidification treatment at achieving the site specific performance criteria, including an unconfined compressive strength of greater than 170 kPa (25 psi) and a permeability of less than 1x10-6 cm/sec. Technical oversight and on-site sampling and analysis were provided to evaluate pilot-scale application of the selected technology and verify treatment effectiveness. The project was divided into several subtasks. First, laboratory treatability testing was conducted to verify that performance specifications were achievable using the proposed reagent formulations. Next, a pilot demonstration was performed by Geo-Con using a Manotowoc 4000 crane equipped with a 1.5-meter diameter auger to evaluate shallow soil mixing. The final task included a comparative study between the performance of test specimens collected using wet sampling techniques versus in situ post-treatment coring

  12. Pilot demonstration for containment using in situ soil mixing techniques at a chemical disposal superfund site

    Energy Technology Data Exchange (ETDEWEB)

    Zarlinski, S.J.; Kingham, N.W.; Semenak, R. [Kiber Environmental Services, Inc., Atlanta, GA (United States)

    1997-12-31

    Kiber Environmental Services, Inc. (Kiber), under contract to McLaren-Hart Corporation and the site PRP group, performed technical oversight and on-site sampling and analyses at the confidential site located in Texas. The site consists of 15,000 cubic meters (20,000 cubic yards) of contaminated materials that were to be solidified on-site. The contaminants included heavy metals, PAHs, oil and grease, and volatile organics. Groundwater is less than 1 meter from the surface. Kiber was retained after several unsuccessful efforts to find on-site containment methods that effectively solidified the waste pits while achieving the performance goals. The PRP group then contracted with Kiber to perform the treatability and pilot oversight studies. The full-scale pilot demonstration was performed by Geo-Con. Pilot-scale treatment was performed to evaluate the effectiveness of in situ solidification treatment at achieving the site specific performance criteria, including an unconfined compressive strength of greater than 170 kPa (25 psi) and a permeability of less than 1x10{sup -6} cm/sec. Technical oversight and on-site sampling and analysis were provided to evaluate pilot-scale application of the selected technology and verify treatment effectiveness. The project was divided into several subtasks. First, laboratory treatability testing was conducted to verify that performance specifications were achievable using the proposed reagent formulations. Next, a pilot demonstration was performed by Geo-Con using a Manotowoc 4000 crane equipped with a 1.5-meter diameter auger to evaluate shallow soil mixing. The final task included a comparative study between the performance of test specimens collected using wet sampling techniques versus in situ post-treatment coring.

  13. Novel, In-situ NAPL Modification Technique for Persistent Source Zone Control and Remediation

    Science.gov (United States)

    Mateas, D. J.; Tick, G. R.; Carroll, K. C.

    2014-12-01

    Non-aqueous phase liquids (NAPLs), such as fuels and solvents, are a major cause of groundwater and soil contamination. This environmental issue has led to concerted efforts to remediate subsurface systems impacted by NAPL pollution, but unfortunately, few of these remediation techniques have succeeded in lowering target contaminant levels below regulatory thresholds. To overcome these limitations, a novel, in-situ source remediation method was tested in the laboratory using equilibrium batch tests and two-dimensional flow cell experiments. The goal of this remediation method was to reduce the aqueous solubility, mass flux, and mass discharge of the target NAPL by the in-situ creation of a NAPL mixture source zone. Predetermined volumes of insoluble n-hexadecane or vegetable oil ("benign" NAPL) were injected into a trichloroethene or toluene ("toxic" NAPL) source zone through a simulated well within the flow cell to form a NAPL mixture. Initial NAPL-aqueous phase batch tests were conducted prior to the flow cell experiments to evaluate the effects of various NAPL mixture ratios on equilibrium aqueous-phase concentrations, and thus, to design optimal benign NAPL injection volumes for the flow cell experiments. Overall, this study indicated that the delivery of benign NAPL into the target, toxic NAPL source zone was effective in significantly reducing contaminant aqueous-phase concentration, mass flux, and mass discharge at intermediate scales. Variations in remediation performance did occur among the various predetermined injection volumes of benign NAPL and the target, toxic NAPL but were consistent to trends observed in batch tests. This novel remediation method may be feasible at larger scales, such as pilot field-scale studies, and may be a cost-effective solution to efficiently mitigate environmental pollution, attain regulatory compliance, and expedite site closure.

  14. Synthesis of magnesia stabilized zirconia by co-precipitation technique

    International Nuclear Information System (INIS)

    The demand for new structural elements possessing a combination of properties such as good strength retention at high temperatures and high resistance to corrosion that find application in nuclear, aerospace, fuel cells etc., have led to the development of new materials as well as improvement in existing materials. Among the important development in the later direction is the synthesis of Stabilized Zirconia. This paper deals with the synthesis of oxide powders of magnesia stabilized zirconia used for high temperature applications mentioned above. Salts of zirconium oxy chloride and magnesium chloride were used as the precursors. The process involved controlled reaction of an aqueous solution of ammonium hydroxide into a solution containing zirconium oxy chloride and magnesium chloride. The resulting solution was filtered, dried and calcined. XRD, SEM/EDAX analyses were done and the results are reported. Variation of conductivity with temperature has also been studied. (author)

  15. An in situ hybridization technique for the study of B19 human parvovirus replication in bone marrow cell cultures.

    Science.gov (United States)

    Vassias, I; Perol, S; Coulombel, L; Thebault, M C; Lagrange, P H; Morinet, F

    1993-10-01

    An in situ hybridization technique using digoxigenin labelling was developed to study B19 infection. By using appropriate DNA probes, transcription of structural and non-structural genes was detected in bone marrow cell cultures. Such a simple system is useful to the study of B19-cell interactions in non-permissive cell lines. PMID:8263124

  16. Optical techniques for microwave frequency stabilization : resonant versus delay line approaches and related modelling problems

    OpenAIRE

    Merrer, Pierre-Henri; Brahimi, Houda; Llopis, Olivier

    2008-01-01

    Optical techniques for microwave oscillators stabilization or microwave sources phase noise measurement are discussed. The advantage in terms of Q factor of optical resonant devices goes with increased difficulties in the system stabilization. System modelling is also complex, because of the interaction of noise sources around three different frequencies : optical, microwave and baseband.

  17. Following the Transient Reactions in Lithium-Sulfur Batteries Using In an In Situ Nuclear Magnetic Resonance Technique

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Jie; Hu, Jian Z.; Chen, Honghao; Vijayakumar, M.; Zheng, Jianming; Pan, Huilin; Walter, Eric D.; Hu, Mary Y.; Deng, Xuchu; Feng, Ju; Liaw, Bor Yann; Gu, Meng; Deng, Zhiqun; Lu, Dongping; Xu, Suochang; Wang, Chong M.; Liu, Jun

    2015-05-13

    Li-S batteries hold great potential for next-generation, large-format power source applications; yet, the fundamental understanding of the electrochemical reaction pathways remains lacking to enable their functionality as promised. Here, in situ NMR technique employing a specially designed cylindrical micro battery was used to monitor the chemical environments around Li+ ions during repetitive charge-discharge process and track the transient electrochemical and chemical reactions occurring in the whole Li-S system. The in situ NMR provides real time, quantitative information related to the temporal concentration variations of the polysulfides with various chain lengths, providing important clues for the reaction pathways during both discharge and charge processes. The in-situ technique also reveals that redox reactions may involve transient species that are difficult to detect in ex-situ NMR study. Intermediate species such as charged free radicals may play an important role in the formation of the polysulfide products. Additionally, in situ NMR measurement simultaneously reveals vital information on the 7Li chemical environments in the electrochemical and parasitic reactions on the lithium anode that promotes the understanding of the failure mechanism in the Li-S system. These new insights could help design effective strategies to accelerate the development of Li-S battery technology.

  18. Towards a more realistic picture of in situ biocide actions: Combining physiological and microscopy techniques

    Energy Technology Data Exchange (ETDEWEB)

    Speranza, M., E-mail: speranzamariela@gmail.com [Museo Nacional de Ciencias Naturales, MNCN-CSIC, Serrano 115 bis, 28006 Madrid (Spain); Wierzchos, J.; De Los Rios, A.; Perez-Ortega, S. [Museo Nacional de Ciencias Naturales, MNCN-CSIC, Serrano 115 bis, 28006 Madrid (Spain); Souza-Egipsy, V. [Instituto de Ciencias Agrarias, ICA-CSIC, Serrano 115 bis, 28006 Madrid (Spain); Ascaso, C., E-mail: ascaso@mncn.csic.es [Museo Nacional de Ciencias Naturales, MNCN-CSIC, Serrano 115 bis, 28006 Madrid (Spain)

    2012-11-15

    In this study, we combined chlorophyll a fluorescence (ChlaF) measurements, using pulse-amplitude-modulate (PAM) equipment, with scanning electron microscopy in backscattered electron mode (SEM-BSE) and transmission electron microscopy (TEM) images to evaluate the actions of Koretrel at lower concentrations on Verrucaria nigrescens colonising a dolostone. ChlaF measurements are good indicators of the damaging effects of biocides. However, these indicators only provide an incomplete view of the mechanism of biocides used to control biodeterioration agents. The death of the V. nigrescens photobiont at two biocide concentrations was revealed by PAM, SEM-BSE and TEM. Once Koretrel was applied, the Fv/Fm ratios markedly fell in the first few hours after the 1.5% treatment, and ratios for the 3% dilution remained close to zero throughout the study. The algal zone shows the plasmolysed appearance of the photobiont cells, and important aspects related to the action of the biocide on free and lichenised fungi were also detected using SEM-BSE. Many of the mycobiont cells had only their cell walls preserved; although, some fungal hyphae in lichen thalli and some microorganisms in endolithic clusters maintained lipid storage in their cytoplasm. These results indicated that the combination of physiological and microscopy techniques improves the assessment of biocide action in situ and this will help to optimize protocols in order to reduce the emission of these compounds to the environment. -- Highlights: Black-Right-Pointing-Pointer We combined ChlaF measurements with EM images to analyses the biocides action on stone biodeterioration agents. Black-Right-Pointing-Pointer At lower biocide concentrations damage to photobiont and mycobiont cells integrity, ultrastructure and vitality were observed. Black-Right-Pointing-Pointer The limited action of biocides on fungi and algae were detected using SEM-BSE. Black-Right-Pointing-Pointer The combination of physiological and microscopy techniques improves the assessment of biocide action in situ. Black-Right-Pointing-Pointer This new approach will help to optimize protocols of biocide application on stone.

  19. In situ AFM studies of the stability of MgO(1 0 0) in aqueous electrolytes

    International Nuclear Information System (INIS)

    Highlights: • Stability and dissolution of MgO(1 0 0) surfaces in alkaline solutions of NaCl and NaClO4. • Stability determined by the hydrogen network between the water and the oxide surface. • Formation of a hydroxide gel-like layer in absence of chloride. • Report of square pits oriented in the ?1 1 0? directions during immersion in NaCl. • Substitution of hydroxides by chlorides at the electrolyte/MgO interface. - Abstract: The stability and dissolution of MgO(1 0 0) single crystal surfaces in alkaline solutions of NaClO4 and NaCl were investigated by means of in situ atomic force microscopy (AFM) and ex situ angle resolved X-ray photoelectron spectroscopy (AR-XPS). MgO surfaces showed higher resistance to dissolution in NaClO4 electrolyte due to the formation of a gel-like hydroxide layer. The emergence of rectangular/square formed pits oriented in the ?1 1 0? directions during immersion in NaCl electrolytes at alkaline pH was observed. The results are discussed on the basis of a substitution of hydroxides by chlorides at the electrolyte/MgO interface

  20. Dimensional stability of a novel polyvinyl siloxane impression technique

    Scientific Electronic Library Online (English)

    Moira Pedroso, Leão; Camila Paloma, Pinto; Ana Paula, Sponchiado; Bárbara Pick, Ornaghi.

    2014-04-01

    Full Text Available AIM: To introduce a modification of the reline impression technique (MRIT), and compare the dimensional changes of impressions obtained by MRIT and by conventional reline impression technique (CRIT). METHODS: An acrylic resin tablet was milled by a CAD-CAM system to simulate three abutments (A [...] , B and C) with different distances among them. The abutments were molded using both impression techniques. For MRIT, before completing the putty silicone polymerization, the relieve procedure was made by compression and it was immediately repositioned to complete the polymerization. Impressions were stored dry at room temperature for different periods (immediately, 1 h, 2 days and 7 days). The distances were obtained by scanning. The differences between the impressions and their respective matrix reference measurements were calculated to determine the dimensional changes. Data were subjected to ANOVA and Tukey's test (p

  1. Development of an in situ derivatization technique for rapid analysis of levoglucosan and polar compounds in atmospheric organic aerosol

    Science.gov (United States)

    Sheesley, Rebecca J.; Mieritz, Mark; DeMinter, Jeff T.; Shelton, Brandon R.; Schauer, James J.

    2015-12-01

    A novel thermal desorption gas chromatography mass spectrometry (TD-GCMS) technique was developed for the analysis of levoglucosan and other polar compounds in atmospheric organic aerosol. The method employs an in situ derivatization to add tri-methylsilyl groups to alcohol functional groups on simple carbohydrates, like levoglucosan and sterols. The new method was then demonstrated on a set of 40 filter samples collected in Fresno, CA. The results from the in situ silylation TD-GCMS method were compared, using levoglucosan, with a solvent extraction, high-volume injection GCMS method resulting in an r2 = 0.91.

  2. A rapid colour stabilization technique for radiochromic film dosimetry

    International Nuclear Information System (INIS)

    Various forms of GAFChromic film have been used for several years as radiographic media for measuring dose distributions of brachytherapy sources and small radiation fields. Upon irradiation the film changes colour and darkens with time post-irradiation. The darkening is most rapid in the first 24 h, and it has been suggested that for accurate dosimetry a waiting period of 24 h should occur before any optical density (OD) measurements are taken. A more rapid colour stabilization (RCS) procedure has been developed and is evaluated. The procedure consists of heating the film post-irradiation for a period of 2 h at 45 deg. C. The RCS procedure is compared with a control group and the dose response is tested for linearity, stability and reproducibility using two densitometers with light sources at different wavelengths (632.8 nm and 671 nm). The rise in net optical density (NOD) for the period 3-168 h is less than 3% for the RCS group as compared with 12% for the controls. In the first 24 h, the increase in NOD for the RCS samples is less than 0.5%, as opposed to 6% for the control group. (author)

  3. In Situ Stabilization of Trace Metals in a Copper-Contaminated Soil using P-Spiked Linz-Donawitz Slag

    OpenAIRE

    Negim, O.; MENCH, Michel; Bes, Clémence; Motelica-Heino, Mikael; Amin, Fouad; Le Coustumer, Philippe

    2012-01-01

    P-spiked Linz-Donawitz (LD) slag was used as a soil additive to improve physico-chemical soil properties and in situ stabilize Cu and other trace metals in a sandy Cu-contaminated soil (630 mg kg-1 soil) from a former wood preservation site. The LD slag was incorporated into the contaminated soil to consist four treatments: 0 % (T1), 1 % (T2), 2 % (T3), and 4 % (T4) per air-dried soil weight. A similar uncontaminated soil was used as a control (CTRL). After a one-month reaction period, potted...

  4. FISH and Calcofluor staining techniques to detect in situ filamentous fungal biofilms in water.

    Science.gov (United States)

    Gonçalves, Ana B; Santos, Isabel M; Paterson, R Russell M; Lima, Nelson

    2006-09-01

    Filamentous fungi are a ubiquitous and diverse group of eukaryotic organisms and may contribute, along with bacteria, yeasts, protozoa and viruses, to the formation of biofilms in water distribution systems. However, fungal involvement in biofilms has not been demonstrated unambiguously. Furthermore, these fungi may be responsible for the production of tastes, odours and mycotoxins in drinking water making their early detection important. The detection of fme these problems a combination of two fluorescent techniques for direct detection was tested: (a) Fluorescence In Situ Hybridization (FISH) employing the universal rRNA probe EUK516, labelled with the red Cy3, followed by (b) staining with Calcofluor White MR2 fluorescent dye which stains fungal cell walls blue. Pure cultures of Penicillium brevicompactum were used to establish the methods followed by separate experiments with real water biofilm samples in PVC-C and cast iron coupons. FISH demonstrated eukaryotic microrganisms after approximately 5 h while the calcofluor method revealed chitinous filamentous structures in less than one hour. When the two methods were combined, additional resolution was obtained from the images of filamentous walls (blue) with intact protoplasm (red). In conclusion, FISH and Calcofluor staining provide rapid, direct and unambiguous information on the involvement of ff in biofilms which form in water. PMID:17196030

  5. In-situ performance evaluation of radon measurement techniques in Uranium mine exhausts of Jaduguda

    International Nuclear Information System (INIS)

    Several techniques are used for the measurement of the activity concentration of radon in the work place and the environment. Devices like Scintillation cell, Alpha guard and Low Level Radon Detection System (LLRDS) are widely used for the estimation of radon. Some of the devices like scintillation cell is normally used in high activity concentration, whereas, device like LLRDS is used in low activity concentration range. All these above devices are used in ambient mode in which air sample is either collected in a cell or in a chamber and the alpha counts are recorded after a definite delay. In some device, air is allowed to be diffused through a filter and alpha activity is estimated using proper detection system. Passive radon dosimeters can effectively be used both in low and high activity concentration range. The cumulative radon exposure can be assessed using passive radon dosimeters. For in situ performance evaluation an area is required where both high and low level activity concentration of radon is anticipated. Uranium mines exhaust area is presumed to be an area where both these conditions can be found by mere variation in the placement of the device. Inter comparison exercise can also be done effectively at this location using various devices of radon estimation

  6. Prompt gamma-ray activation technique for in-situ analysis of mercury pollution in water

    International Nuclear Information System (INIS)

    Industrial and mining pollutants discharged into water are in general distributed homogeneously and we investigated a prompt neutron activation technique for the in-situ analysis, to start with of Hg content in water. The laboratory test employed a 252 Cf neutron source (of ? 3 x 106 n/s fluence) submerged in a test tank of water of ? 500 litres, and to monitor the gamma-ray emission a 4 x 4 NaI (Tl) detector system was employed. In 3000 is time interval trials, for a 46 ppm contamination level of Hg, we observed an excess of counts of ? 9.2 ? significance in the energy range of 4000-6500 keV, which can be attributed to the presence of mercury. This test system for a 10 hour monitoring can provide a minimum detectable sensitivity at 4.78 ppm. In the future experiments, we propose to replace the NaI(Tl) detector by a HPGe detector to facilitate simultaneous analyses of pollutants such as cadmium, chlorine, chromium etc for detection at few tenths to tens of ppm levels or better. (author). 5 refs., 2 figs., 2 tabs

  7. In situ assessment of the saliva effect on enamel morphology after microabrasion technique

    Scientific Electronic Library Online (English)

    Núbia Inocencya Pavesi, Pini; Débora Alves Nunes Leite, Lima; Renato Herman, Sundfeld; Gláucia Maria Bovi, Ambrosano; Flávio Henrique Baggio, Aguiar; José Roberto, Lovadino.

    2014-09-01

    Full Text Available AIM: This study evaluated saliva effects on enamel morphology surface after microabrasion technique. METHODS: Enamel blocks (16 mm2) obtained from bovine incisors were divided into 9 groups as follows: one control group (no treatment), four groups with microabrasion treatment using 35% phospho [...] ric acid and pumice (H3PO4+Pum) and other four groups treated with 6.6% hydrochloric acid and silica (HCl+Sil). One group of each treatment was submitted to 4 frames of saliva exposure: without exposure, 1-h exposure, 24-h exposure, and 7-days exposure on in situ regimen. Nineteen volunteers (n=19), considered as statistical blocks, used an intraoral appliance containing the specimens, for 7 days. Enamel roughness (Ra) was tested before and after treatment, and after saliva exposure. Confocal laser scanning microscopy (CLSM) was used to evaluate qualitatively the enamel morphology. RESULTS: All groups exhibited increased Ra after microabrasion. With regards to saliva exposure, the treatment with HCl+Sil presented more susceptibility to the saliva action, but no period of time was efficient in re-establishing this characteristic compared with the control group. CLSM analysis showed reduction of the micro-abrasive damages during the experimental times. CONCLUSIONS: Seven days of saliva exposure were not sufficient for the treated enamel to reach its normal characteristics compared with the control group.

  8. Assessment of phytoremediation as an in-situ technique for cleaning oil-contaminated sites

    International Nuclear Information System (INIS)

    The effectiveness of phytoremediation as a tool for cleaning up hydrocarbon contaminated soil and groundwater was evaluated by reviewing relative literature. Phytoremediation is an emerging technology which consists of the use of plants for in situ treatment of contaminated soils. Grasses, herbs, shrubs and deciduous trees were the main types of plants considered in this study. A database is presently under construction to act as an inventory of plant species that tolerate or phytoremediate petroleum hydrocarbons. This paper focused on the main mechanisms and special considerations involved in the phytoremediation alkanes, aromatics, polycyclic aromatic hydrocarbons, and creosote. While phytoremediation does not require intensive engineering techniques, it does involve human intervention to establish appropriate plants and microorganisms to enhance natural degradation processes. Plants such as canola, oats barley have been shown to tolerate and accumulate metals such as selenium, copper, cadmium and zinc. Hybrid poplar trees reduce the concentration of nitrate in surficial groundwater and degrade the herbicide atrazine. Forage grasses inoculated with bacteria can degrade chlorinated benzoic acids. Various grasses and leguminous plants can increase the removal of petroleum hydrocarbons from contaminated soils. 66 refs., 3 tabs., 2 figs

  9. Valve disruption for in situ vein bypass: use of a new technique.

    Science.gov (United States)

    Enzler, M A; Smith, L L

    1991-11-01

    Following its introduction in 1960, the in situ bypass technique has gradually gained acceptance among vascular surgeons. This can be explained, in part, by the lack of a reliable method for rendering vein valves incompetent. Several instruments developed by Skagseth and Hall, Leather and Karmody, and others have been used. Although most are relatively easy to use, one common drawback is the difficulty in controlling rotation of the cutting blade. This is due to insufficient torsional rigidity of the shaft and the lack of a blade plane indicator. Edwards, in 1936, described the consistent orientation of vein valves, whose margins are always parallel to the overlying skin surface. This knowledge facilitates complete midline incision of the valve cusps, provided that the surgeon is able to control the cutting blade. With this fact in mind, we have developed a new set of instruments. They feature satisfactory torsional rigidity, as well as blade plane indicators at the handle. For the endoscopist, the blade plane is made visible by a mark at the tip of each instrument. Precision-manufactured of stainless steel and welded with laser technology, the instruments are suitable for multiple use, which we consider an advantage from an economic, as well as an ecological viewpoint. PMID:1772767

  10. Thermal stability and in situ SiN passivation of InAlN/GaN high electron mobility heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Lugani, L.; Carlin, J.-F.; Py, M. A.; Grandjean, N. [ICMP, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)

    2014-09-15

    We investigate the thermal stability of nearly lattice-matched InAlN layers under metal organic vapor phase epitaxy conditions for temperatures >800?°C and show that they are not fully stable. In particular, InAlN top layers undergo degradation during high temperature annealing due to a surface related process, which causes the loss of crystal quality. This strongly impacts the transport properties of InAlN/GaN HEMT heterostructures; in particular, the mobility is significantly reduced. However, we demonstrate that high thermal stability can be achieved by capping with a GaN layer as thin as 0.5?nm. Those findings enabled us to realize in situ passivated HEMT heterostructures with state of the art transport properties.

  11. Thermal stability and surface behaviors of CeO2/Si films during in-situ vacuum annealing

    International Nuclear Information System (INIS)

    Highlights: • The surface behaviors of CeO2 film deposited on Si substrate by LMBE during in-situ UHV annealing were analyzed by XPS, and the partial reductions of CeO2 were identified. • The enhanced thermal stability of the partially reduce ceria system due to interfacial reactions was revealed. • Si2p signal as a result of surface segregation was observed during annealing treatment. - Abstract: CeO2 thin films were deposited on Si (1 1 1) substrates by laser molecular-beam epitaxy (LMBE). The thermal stability and surface behaviors of CeO2/Si samples were investigated by X-ray photoelectron spectroscopy during in-situ vacuum annealing. Temperature dependency of surface compositions was identified. At the temperature from 700 K to 1000 K, CeO2 was reduced gradually, but incomplete transformation of CeO2 to Ce2O3 was found even when the sample was annealed at 1000 K for an hour. When the sample was exposed to oxygen ambience, the enhanced thermal stability of the partially reduced surface was revealed by the slight variation of Ce3d and Ce4d spectra. Si2p peak at 102.7 eV was detected on the top surface after the whole heating treatments, while not for the sub-surface during sputtering till to the interface. The Si signal at the outmost surface is induced by surface segregation due to the decreasing solid solubility of Si atoms in CeO2 matrix with the decreasing temperature. At the interface, Si2p peaks at 99.9 eV with the presence of Ce4d peaks at 122.2 eV and 125.6 eV are attributed to the formation of cerium silicates with Ce–Si–O matrix during annealing due to interfacial reactions, which are supposed to stabilize the partially reduced ceria system

  12. Monitoring of cement stabilized surrogate waste using resonant frequency techniques

    International Nuclear Information System (INIS)

    It is often necessary to track incremental changes in the physical properties of composites with portland cement binders caused by chemical attack, freeze-thaw cycles, and other deterioration mechanisms. The vibration testing procedure presented for measuring the resonant frequency of a specimen is directly applicable to the monitoring of the deterioration of stabilized/solidified waste specimens. The change in the fundamental frequency is significantly more sensitive than the loss of mass to the internal changes in the mechanical properties of specimens. The time and effort required to determine the fundamental frequency of a specimen is also significantly less than that required to determine the loss of mass of the same specimen. The proposed method has been demonstrated to work on small cylindrical specimens (44 mm by 74 mm) with aspect ratios less than 2.0. The use of elastomeric bands as the means of attachment of the specimen to the test equipment does not interfere with or limit other chemical and mechanical performance tests scheduled for the specimens

  13. Técnicas in situ de baixo custo em eletroquímica: a microbalança a cristal de quartzo / Low cost in situ techniques in electrochemistry: the quartz crystal microbalance

    Scientific Electronic Library Online (English)

    Hamilton, Varela; Marcos, Malta; Roberto M., Torresi.

    2000-10-01

    Full Text Available [...] Abstract in english Among in situ techniques, the electrochemical quartz crystal microbalance (EQCM) is a powerful tool for the study of electrochemical reactions that produce mass changes in the electrode/solution interface. This review present some systems in which the EQCM combined with classical electrochemical tec [...] hniques, gives relevant information for understanding the charge transport process at a molecular level. The aim of this review is to do a brief description of experimental arrangements, with emphasis on some special cares that must be considered by the users. Secondly, some chosen electrochemical systems where the technique was successfully applied are discussed. Finally, a brief analysis of electroacoustic impedance experiments was done in order to show when the Sauerbrey equation can be used.

  14. Spectral Techniques for Solving PDE Stability Model of Vortex Rope

    CERN Document Server

    Bistrian, Diana Alina

    2012-01-01

    In this paper spectral methods are applied to investigate the hydrodynamic instability of swirling flow with application to Francis hydraulic turbine. Spectral methods imply representing the problem solution as truncated series of smooth global functions. An L2 - projection and the collocation methods are developed assessing both analytically methodology and computational techniques using symbolic and numerical conversions. Remarks concerning the efficiency and the accuracy of each method in this case are presented. The model of the trailing vortex is used to validate the numerical algorithms with existing results in the literature. All the results are compared to existing ones and they prove to agree quite well. The advantages of using this methods in flow control problems are pointed out.

  15. Evaluation of some by-Products using In situ and In vitro Gas Production Techniques

    Directory of Open Access Journals (Sweden)

    Besharati Maghsoud

    2008-01-01

    Full Text Available Food by-products in Iran are produced in high levels. In this study, in situ and in vitro gas production techniques were used to describe nutritive value of apple pomace, tomato pomace and noodle waste. For this purpose two ruminal fistulated sheep were used. Nylon bags which were approximately (6×12 cm containing 5 g samples (2 mm screen were incubated in duplicate in the rumen of fistulated sheep for 0,2,4,6,8,12,16,24,36 and 48 h. The gas production was recorded after 2, 4, 6, 8, 12, 16, 24, 36 and 48 h of incubation and the equation of P = A (1-e-ct was used to describe the kinetics of gas production. The data was analyzed using completely randomized design. DM and CP disappearance were significantly different among feedstuffs (p<0.05. After 48 h of incubation DM disappearance in noodle waste was highest and in tomato pomace was lowest. Regarding to the results, at the most incubation times tomato pomace had lower CP disappearance among feedstuffs (p<0.05. Potential gas production (A and rates of gas production (c differed among feedstuffs. Apple pomace showed higher potential gas production (A (305.1 mL g?1 DM and tomato pomace had higher rate of gas production (c (0.09 h?1 than the other feedstuffs. According to gas production volume, the value for the ME, OMD and SCFA ranged from in 8.87 noodle waste to 9.76 in apple pomace, 56.1 in tomato pomace to 64.3 in apple pomace and 0.919 in noodle waste to 1.168 in apple pomace, respectively. Partitioning factor in noodle waste was highest and in tomato pomace was lowest. In the present study, feeds composition significantly affected the degradation parameters.

  16. Simultaneous in situ Optical Monitoring Techniques during Crystal Growth of ZnSe by Physical Vapor Transport

    Science.gov (United States)

    Su, C.- H.; Feth, S.; Lehoczky, S. L.

    1998-01-01

    ZnSe crystals grown in sealed ampoules by the physical vapor transport method were monitored in situ using three techniques, simultaneously. A Michelson interferometer was set-up to observe the growth rate and surface morphological evolution. An interference pattern (interferogram) is formed by the interaction between the reflection of a HeNe laser (632.8 nm wavelength) off the crystal-vapor interface and a reference beam from the same laser. Preliminary results indicate that the rate of growth/thermal-etching can be calculated using analog data acquisition and simple fringe counting techniques. Gross surface features may also be observed using a digital frame grabber and fringe analysis software. The second in situ technique uses optical absorption to determine the partial pressures of the vapor species. The Se2 and Zn vapor species present in the sealed ampoule absorb light at characteristic wavelengths. The optical absorption is determined by monitoring the light intensity difference between the sample and reference beams. The Se2 Partial pressure profile along the length of the ampoule was estimated from the vibronic absorption peaks at 340.5, 350.8, 361.3 and 379.2 nm using the Beer's law constants established in the calibration runs of pure Se. Finally, because the high temperature crystal growth furnace contains windows, in situ visual observation of the growing crystal is also possible. The use of these techniques not only permits in situ investigation of high temperature vapor growth of semiconductors, but also offers the potential for real time feed back on the growing crystal and allows the possibility of actively controlling the growth process.

  17. Styrene grafted natural rubber reinforced by in situ silica generated via sol–gel technique

    International Nuclear Information System (INIS)

    Highlights: • Sol–gel reaction by NR latex was the absence of use of organic solvent and base catalyst. • Well dispersed in situ formed silica particles in the rubber matrix were obtained. • In situ silica was better to improve mechanical properties of rubber vulcanizates. -- Abstract: The filling of styrene graft natural rubber (ST-GNR) with in situ formed silica was performed using the sol–gel reaction via the latex solution method. The mechanical properties of ST-GNR/NR vulcanizate were improved when using the in situ formed silica to levels higher than those obtained with the commercial ex situ formed silica filled ST-GNR/NR vulcanizates at a comparable silica content of 12 parts by weight per hundred parts of rubber. Transmission electron microscopy analysis revealed that the in situ silica particles were small (?40 nm diameter) and well dispersed, while the commercial silica particles were larger (?60 nm diameter) and markedly agglomerated in the rubbery matrix. The mechanical properties of the composites prepared via both the solid rubber and latex solution methods were comparable

  18. Robust Coordinated Design of PSS and TCSC using PSO Technique for Power System Stability Enhancement

    OpenAIRE

    Panda, S.; N. P. Padhy; R. N. Patel

    2007-01-01

    Power system stability improvement by coordinated design of a Power System Stabilizer (PSS) and a Thyristor Controlled Series Compensator (TCSC) controller is addressed in this paper. Particle Swarm Optimization (PSO) technique is employed for optimization of the parameterconstrained nonlinear optimization problem implemented in a simulation environment. The proposed controllers are tested on a weakly connected power system. The non-linear simulation results are presented for wide range of lo...

  19. Empleo de la técnica hibridación in situ fluorescente para visualizar microorganismos / Use of fluorescence in situ hybridization technique to visualize microorganisms

    Scientific Electronic Library Online (English)

    Raúl, Rodríguez Martínez.

    2011-12-01

    Full Text Available La hibridación in situ fluorescente (FISH), es una técnica que emplea sondas de oligonucleótidos marcadas con fluorocromos las cuales van dirigidas hacia secuencias específicas del ácido ribonucleico ribosomal (ARNr), lo que permite la identificación rápida y específica de células microbianas ya sea [...] que estén como células individuales o se encuentren agrupadas en su ambiente natural. El conocimiento de la composición y distribución de los microorganismos en los hábitats naturales, proporciona un soporte sólido para comprender la interacción entre las diversas especies que componen el micro hábitat. El objetivo de la revisión es presentar la forma como ha evolucionado la hibridación, el empleo del ARNr como molécula diana, los tipos de marcaje, los marcadores fluorescentes empleados hoy en día, la metodología, así como las mejoras que se le han hecho a la técnica FISH al emplearse en conjunto con otras técnicas en la identificación microbiana. Salud UIS 2011; 43 (3): 307-316 Abstract in english Fluorescence in situ hybridization (FISH), is a technique that uses oligonucleotides probes labeled with fluorochromes which are directed to specific sequences of ribosomal ribonucleic acid (rRNA), this allows the rapid and specific identification of microbial cells whether as individual cells or gr [...] ouped cells in their natural environment. Knowledge of the composition and distribution of microorganisms in natural habitats provides a solid support to understand interaction between different species in the microhabitat. This review shows how hybridization has evolved, the use of rRNA as target molecule, the type of labeling, the labeled uses today in fluorescent and the methodology, as well as the improvements that have been made to the FISH technique when is used in conjunction with other techniques in microbial identification. Salud UIS 2011; 43 (3): 307-316

  20. Stability of Porous Platinum Nanoparticles: Combined In Situ TEM and Theoretical Study

    DEFF Research Database (Denmark)

    Chang, Shery L. Y.; Barnard, Amanda S.; Dwyer, Christian; Hansen, Thomas Willum; Wagner, Jakob Birkedal; Dunin-Borkowski, Rafal E.; Weyland, Matthew; Konishi, Hiromi; Xu, Huifang

    2012-01-01

    Porous platinum nanoparticles provide a route for the development of catalysts that use less platinum without sacrificing catalytic performance. Here, we examine porous platinum nanoparticles using a combination of in situ transmission electron microscopy and calculations based on a first-principles-parametrized thermodynamic model. Our experimental observations show that the initially irregular morphologies of the as-sythesized porous nanoparticles undergo changes at high temperatures to morpho...

  1. Optical and structural properties of radiolytically in situ synthesized silver nanoparticles stabilized by chitosan/poly(vinyl alcohol) blends

    International Nuclear Information System (INIS)

    In this study, the potential of chitosan/poly(vinyl alcohol) (CS/PVA) blends as capping agent for stabilization of Ag-nanoparticles (Ag NPs) during their in situ gamma irradiation induced synthesis was investigated. The UV–vis absorption spectra show the surface plasmon absorption band around 410 nm, which confirms the formation of Ag-nanoparticles. It was found that the composition of CS/PVA blend affected the size of the obtained Ag-nanoparticles, as well as the parameters such as density, molar concentration and effective surface area, calculated from the experimentally obtained UV–vis absorption spectra and spectra obtained by simulation according to the Mie theory. SEM micrograph and XRD measurement indicated a spherical morphology and face centered cubic crystal structure of Ag-nanoparticles, with diameter around 12 nm. The values of optical band gap energy between valence and conduction bands (Eg), calculated from the UV–vis absorption spectra, also show dependence on the blend composition for Ag–CS/PVA colloids as well as for Ag–CS/PVA nanocomposites. - Highlights: • Ag NPs were synthesized by ?-irradiation and stabilized by CS/PVA blends. • Composition of CS/PVA blends has influence on the size of spherical Ag NPs. • simulation based on Mie theory was used to calculate the parameters of Ag NPs. • Ag NPs are stabilized through interactions with -OH and -NH2 groups of polymers. • Optical band gap energy was calculated from UV–vis spectra by Tauc's expression

  2. Development of the DGT technique for in-situ Pu speciation measurements

    International Nuclear Information System (INIS)

    Toxic effects of artificial radionuclides are strongly dependent on the surrounding chemical environment which determines the bioavailability of contaminant species. Speciation of plutonium in the environment is of particular interest since it is a long-life actinide contributing to the dose exposure via ingestion with water and food in case of radioactive discharge. Furthermore, natural colloids present in waters, as main carriers of dissolved trace metals, can transport plutonium over significant distances from contaminated sites. The diffusive gradients in thin films (DGT) technique is an efficient instrument for passive sampling of trace metals. It allows for in-situ monitoring of mean concentrations of bioavailable contaminant species (1). A DGT sampler consists of two gel layers: a polyacrylamide hydrogel diffusion layer allowing to diffuse labile metal species to the second, binding layer, impregnated with ion-exchange resin. Resin elution and further analysis allow determining the amount of the bioavailable fraction of trace metals in the bulk solution, which can be calculated from the relationship: Cbulk= (M x ?g)/(D x t x A) where M is the measured metal species inventory in the resin, ?g the thickness of the diffusion layer, D the diffusion coefficient of the species in the gel, t the time of deployment, A the diffusion area. To our knowledge, the DGT has not yet been applied for Pu speciation measurements and the D value is unknown. Here we propose the use of DGT to monitor the dissolved phase and labile complexes of plutonium in the aquatic environment. We have first measured the diffusion coefficient of plutonium in the hydrogel. Experiments were carried out in a diffusion cell (2) and with commercially available DGT samplers exposed in standardized solutions containing 239Pu at pico-molar concentrations. Both approaches give comparable D values in the range of 2.30 x 10-6 - 2.45 x 10-6 cm2 s-1. We then studied plutonium diffusion in the presence of naturally occurring ligands - fulvic and humic acids - and in natural waters sampled at a mineral spring and an organic-rich brook of a karst system in the Swiss Jura Mountains, in which the increased mobility of 239+240Pu compared to 241Am and 137Cs has been recently observed (3). Diffusion experiments in simulated natural conditions show different mobility of the radionuclide in fresh waters with different DOM content, supporting the idea that the speciation of plutonium and the abundance of free ionic form in particular, are of prime importance to better estimate the bioavailability and the toxicity of plutonium. (authors)

  3. Development of the DGT technique for in-situ Pu speciation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Cusnir, R.; Bochud, F.; Froidevaux, P. [Institute of Radiation Physics, Lausanne University Hospital, Rue du Grand-Pre 1, CH-1007 Lausanne (Switzerland); Steinmann, P. [Federal Office of Public Health, Swarzenburgstrasse 165, CH-3003 Bern (Switzerland)

    2014-07-01

    Toxic effects of artificial radionuclides are strongly dependent on the surrounding chemical environment which determines the bioavailability of contaminant species. Speciation of plutonium in the environment is of particular interest since it is a long-life actinide contributing to the dose exposure via ingestion with water and food in case of radioactive discharge. Furthermore, natural colloids present in waters, as main carriers of dissolved trace metals, can transport plutonium over significant distances from contaminated sites. The diffusive gradients in thin films (DGT) technique is an efficient instrument for passive sampling of trace metals. It allows for in-situ monitoring of mean concentrations of bioavailable contaminant species (1). A DGT sampler consists of two gel layers: a polyacrylamide hydrogel diffusion layer allowing to diffuse labile metal species to the second, binding layer, impregnated with ion-exchange resin. Resin elution and further analysis allow determining the amount of the bioavailable fraction of trace metals in the bulk solution, which can be calculated from the relationship: C{sub bulk}= (M x ?g)/(D x t x A) where M is the measured metal species inventory in the resin, ?g the thickness of the diffusion layer, D the diffusion coefficient of the species in the gel, t the time of deployment, A the diffusion area. To our knowledge, the DGT has not yet been applied for Pu speciation measurements and the D value is unknown. Here we propose the use of DGT to monitor the dissolved phase and labile complexes of plutonium in the aquatic environment. We have first measured the diffusion coefficient of plutonium in the hydrogel. Experiments were carried out in a diffusion cell (2) and with commercially available DGT samplers exposed in standardized solutions containing {sup 239}Pu at pico-molar concentrations. Both approaches give comparable D values in the range of 2.30 x 10{sup -6} - 2.45 x 10{sup -6} cm{sup 2} s{sup -1}. We then studied plutonium diffusion in the presence of naturally occurring ligands - fulvic and humic acids - and in natural waters sampled at a mineral spring and an organic-rich brook of a karst system in the Swiss Jura Mountains, in which the increased mobility of {sup 239+240}Pu compared to {sup 241}Am and {sup 137}Cs has been recently observed (3). Diffusion experiments in simulated natural conditions show different mobility of the radionuclide in fresh waters with different DOM content, supporting the idea that the speciation of plutonium and the abundance of free ionic form in particular, are of prime importance to better estimate the bioavailability and the toxicity of plutonium. (authors)

  4. A Signal Transmission Technique for Stability Analysis of Multivariable Non-Linear Control Systems

    Science.gov (United States)

    Jackson, Mark; Zimpfer, Doug; Adams, Neil; Lindsey, K. L. (Technical Monitor)

    2000-01-01

    Among the difficulties associated with multivariable, non-linear control systems is the problem of assessing closed-loop stability. Of particular interest is the class of non-linear systems controlled with on/off actuators, such as spacecraft thrusters or electrical relays. With such systems, standard describing function techniques are typically too conservative, and time-domain simulation analysis is prohibitively extensive, This paper presents an open-loop analysis technique for this class of non-linear systems. The technique is centered around an innovative use of multivariable signal transmission theory to quantify the plant response to worst case control commands. The technique has been applied to assess stability of thruster controlled flexible space structures. Examples are provided for Space Shuttle attitude control with attached flexible payloads.

  5. HIBRIDACIÓN IN SITU PARA LA DETECCIÓN DE Streptococcus agalactiae EN TEJIDOS DE TILAPIA (Oreochromis sp.) / IN SITU HYBRIDIZATION TECHNIQUE FOR Streptococcus agalactiae DETECTION IN TILAPIA TISSUES (Oreochromis sp.)

    Scientific Electronic Library Online (English)

    E. A, Pulido; C. A, Iregui.

    2010-04-01

    Full Text Available La estreptococosis es uno de los problemas sanitarios más serios en la acuicultura mundial. En Colombia la enfermedad afecta de manera importante las explotaciones de tilapia. Se estandarizó la técnica de hibridación in situ (HIS) en tejidos de tilapia previamente identificados como positivos a la p [...] resencia de S. agalactiae por la técnica de inmunoperoxidasa indirecta (IPI) y microbiología. Se obtuvo señal positiva en el interior de los granulomas con una especificidad del 100%. Se logró amplificar significativamente la señal mediante el uso de la tiramida. La HIS en tejidos de tilapia puede ser usada para el diagnóstico y estudios de patogenésis y epidemiológicos con este microorganismo. Se requieren futuras investigaciones para optimizar la marcación de las bacterias libres en los tejidos y evaluar la sensibilidad de la técnica. Abstract in english Streptococcosis is one of the most important health problems in world aquaculture. In Colombia, the disease affects significantly tilapia farms. The standardization of the HIS technique was achieved in tilapia tissues previously identified as positive for the presence of S. agalactiae by other techn [...] iques as indirect immunoperoxidase technique (IPI) and microbiology. Positive signal was obtained within the granulomas with specificity of 100%. The usefulness of the tiramide about increasing the signal intensity was confirmed. The HIS in tilapia tissues can be used in the diagnosis, pathogenesis and epidemiological studies of the disease. Further research is required to optimize the hybridization of bacteria located free in the tissues and to assess the technique sensitivity.

  6. Effect of Ag on the thermal stability of deformation processed Cu-Fe in situ composites

    Energy Technology Data Exchange (ETDEWEB)

    Gao Haiyan [State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China)], E-mail: gaohaiyan@sjtu.edu.cn; Wang Jun [State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China)], E-mail: junwang@sjtu.edu.cn; Sun Baode [State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2009-02-05

    Thermal stabilities of deformation processed Cu-12Fe and Cu-11Fe-6Ag composites were investigated through isochronic aging treatments. The morphology transitions of the Fe filaments and the Cu matrix were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectrometer (EDS) equipped on the TEM. The results show that during the annealing treatment the Fe filaments experienced longitudinal splitting, cylinderization, break-up and spheroidization. Addition of Ag can reduce the thermal stability of the deformed Fe filaments and accelerate the precipitation kinetics of Fe from the Cu matrix.

  7. DC Microgrids – Part I: A Review of Control Strategies and Stabilization Techniques

    DEFF Research Database (Denmark)

    Dragicevic, Tomislav; Lu, Xiaonan

    2015-01-01

    This paper presents a review of control strategies, stability analysis and stabilization techniques for DC microgrids (MGs). Overall control is systematically classified into local and coordinated control levels according to respective functionalities in each level. As opposed to local control which relies only on local measurements, some line of communication between units needs to be made available in order to achieve coordinated control. Depending on the communication method, three basic coordinated control strategies can be distinguished, i.e. decentralized, centralized and distributed control. Decentralized control can be regarded as an extension of local control since it is also based exclusively on local measurements. In contrast, centralized and distributed control strategies rely on digital communication technologies. A number of approaches to using these three coordinated control strategies to achieve various control objectives are reviewed in the paper. Moreover, properties of DC MG dynamics and stability are discussed. The paper illustrates that tightly regulated point-of-load (POL) converters tend to reduce the stability margins of the system since they introduce negative impedances, which can potentially oscillate with lightly damped power supply input filters. It is also demonstrated how the stability of the whole system is defined by the relationship of the source and load impedances, referred to as the minor loop gain. Several prominent specifications for the minor loop gain are reviewed. Finally, a number of active stabilization techniques are presented.

  8. A novel fluorescent in situ hybridization technique for detection of Rickettsia spp. in archival samples

    DEFF Research Database (Denmark)

    Svendsen, Claus Bo; Boye, Mette; Struve, Carsten; Krogfelt, Karen A.

    2009-01-01

    A novel, sensitive and specific method for detecting Rickettsia spp. in archival samples is described. The method involves the use of fluorescently marked oligonucleotide probes for in situ hybridization. Specific hybridization of Ricekttsia was found without problems of cross-reactions with bacterial species shown to cross-react serologically.

  9. A novel fluorescent in situ hybridization technique for detection of Rickettsia spp. in archival samples

    DEFF Research Database (Denmark)

    Svendsen, Claus Bo; Boye, Mette; Struve, Carsten; Krogfelt, Karen A

    2008-01-01

    A novel, sensitive and specific method for detecting Rickettsia spp. in archival samples is described. The method involves the use of fluorescently marked oligonucleotide probes for in situ hybridization. Specific hybridization of Rickettsia was found without problems of cross-reactions with bacterial species shown to cross-react serologically.

  10. Slipped upper femoral epiphysis: Outcome after in situ fixation and capital realignment technique

    Directory of Open Access Journals (Sweden)

    Sanjay Arora

    2013-01-01

    Results: Clinical outcome as assessed by Merle d? Aubigne score was excellent in 6, good in 10, fair in 6 and poor in 1. Half of the in situ fixation patients underwent osteoplasty procedure for femoroacetabular impingement and 5 more were symptomatic. The head neck offset and ? angle after in situ pinning were -1.12 ± 3 mm and 66.05 ± 9.7°, respectively and this improved to 8.7 mm and 49°, respectively, after osteoplasty. One child in the pinning group had chondrolysis. Eight patients with severe slip underwent capital realignment. Mean followup was 20.15 months. The anterior head neck offset and ? angle were corrected to 6.8 ± 1.72 mm and 44.6 ± 7.0° mm, respectively. Two children with unstable slip in the capital realignment group had avascular necrosis which was diagnosed at presentation by bone scan. Conclusion: High BMI, vitamin D deficiency and endocrine disorders are associated with SUFE in India and should be evaluated as some of these are amenable to prevention and treatment. Most patients treated with in situ pinning developed femoroacetabular impingement. The early results after capital realignment procedure are encouraging and help to avoid a second procedure which is needed in a majority of patients who underwent in situ pinning.

  11. An optically controlled microwave phase stabilizer based on polarization interference technique using semiconductor optical amplifier

    Science.gov (United States)

    Chen, Han; Sun, Mingming; Sun, Xiaohan

    2014-03-01

    We introduce an optically controlled microwave phase stabilizer based on polarization interference technique using single semiconductor optical amplifier (SOA). A prototype with a frequency of 10 GHz is experimentally demonstrated. It provides a stable phase drift that can be linearly compensated over 10 km single-mode fiber by controlling the SOA injection current.

  12. Field application of activated carbon amendment for in-situ stabilization of polychlorinated biphenyls in marine sediment.

    Science.gov (United States)

    Cho, Yeo-Myoung; Ghosh, Upal; Kennedy, Alan J; Grossman, Adam; Ray, Gary; Tomaszewski, Jeanne E; Smithenry, Dennis W; Bridges, Todd S; Luthy, Richard G

    2009-05-15

    We report results on the first field-scale application of activated carbon (AC) amendment to contaminated sediment for in-situ stabilization of polychlorinated biphenyls (PCBs). The test was performed on a tidal mud flat at South Basin, adjacent to the former Hunters Point Naval Shipyard, San Francisco Bay, CA. The major goals of the field study were to (1) assess scale up of the AC mixing technology using two available, large-scale devices, (2) validate the effectiveness of the AC amendment at the field scale, and (3) identify possible adverse effects of the remediation technology. Also, the test allowed comparison among monitoring tools, evaluation of longer-term effectiveness of AC amendment, and identification of field-related factors that confound the performance of in-situ biological assessments. Following background pretreatment measurements, we successfully incorporated AC into sediment to a nominal 30 cm depth during a single mixing event, as confirmed by total organic carbon and black carbon contents in the designated test plots. The measured AC dose averaged 2.0-3.2 wt% and varied depending on sampling locations and mixing equipment. AC amendment did not impact sediment resuspension or PCB release into the water column over the treatment plots, nor adversely impactthe existing macro benthic community composition, richness, or diversity. The PCB bioaccumulation in marine clams was reduced when exposed to sediment treated with 2% AC in comparison to the control plot Field-deployed semi permeable membrane devices and polyethylene devices showed about 50% reduction in PCB uptake in AC-treated sediment and similar reduction in estimated pore-water PCB concentration. This reduction was evident even after 13-month post-treatment with then 7 months of continuous exposure, indicating AC treatment efficacy was retained for an extended period. Aqueous equilibrium PCB concentrations and PCB desorption showed an AC-dose response. Field-exposed AC after 18 months retained a strong stabilization capability to reduce aqueous equilibrium PCB concentrations by about 90%, which also supports the long-term effectiveness of AC in the field. Additional mixing during or after AC deployment, increasing AC dose, reducing AC-particle size, and sequential deployment of AC dose will likely improve AC-sediment contact and overall effectiveness. The reductions in PCB availability observed with slow mass transfer under field conditions calls for predictive models to assess the long-term trends in pore-water PCB concentrations and the benefits of alternative in-situ AC application and mixing strategies. PMID:19544893

  13. Stability of Porous Platinum Nanoparticles: Combined In Situ TEM and Theoretical Study

    DEFF Research Database (Denmark)

    Chang, Shery L. Y.; Barnard, Amanda S.

    2012-01-01

    Porous platinum nanoparticles provide a route for the development of catalysts that use less platinum without sacrificing catalytic performance. Here, we examine porous platinum nanoparticles using a combination of in situ transmission electron microscopy and calculations based on a first-principles-parametrized thermodynamic model. Our experimental observations show that the initially irregular morphologies of the as-sythesized porous nanoparticles undergo changes at high temperatures to morphologies having faceted external surfaces with voids present in the interior of the particles. The increasing size of stable voids with increasing temperature, as predicted by the theoretical calculations, shows excellent agreement with the experimental findings. The results indicate that hollow-structured nanoparticles with an appropriate void-to-total-volume ratio can be stable at high temperatures.

  14. Engineering feasibility analysis for in-situ stabilization of Burrell Township site residues

    International Nuclear Information System (INIS)

    The Burrell Township site, located in western Pennsylvania, received approximately 11,600 tons of radioactively-contaminated material in late 1956 and early 1957 from the Vitro Manufacturing Company's operations in Canonsburg, Pennsylvania. WESTON was requested to conduct an engineering study to determine the feasibility of stabilizing the site in accordance with the US Environmental Protection Agency's (EPA) interim and proposed standards (45 FR 27366--27368, April 22, 1980, and 46 FR 2556--2563, January 9, 1981). The scope of this study is limited to those alternatives that can be implemented on the site and will not require removal and offsite disposal of radioactively-contaminated material. Four alternatives for control of the radioactive material at the Burrell site were considered and evaluated, as follows: 1. Site stabilization and closure. 2. Site control and containment. 3. Waste excavation and encapsulation. 4. Waste excavation, incineration, and encapsulation. 2 refs., 32 figs., 12 tabs

  15. Engineering feasibility analysis for in-situ stabilization of Burrell Township site residues. [UMTRA

    Energy Technology Data Exchange (ETDEWEB)

    1982-11-01

    The Burrell Township site, located in western Pennsylvania, received approximately 11,600 tons of radioactively-contaminated material in late 1956 and early 1957 from the Vitro Manufacturing Company's operations in Canonsburg, Pennsylvania. WESTON was requested to conduct an engineering study to determine the feasibility of stabilizing the site in accordance with the US Environmental Protection Agency's (EPA) interim and proposed standards (45 FR 27366--27368, April 22, 1980, and 46 FR 2556--2563, January 9, 1981). The scope of this study is limited to those alternatives that can be implemented on the site and will not require removal and offsite disposal of radioactively-contaminated material. Four alternatives for control of the radioactive material at the Burrell site were considered and evaluated, as follows: 1. Site stabilization and closure. 2. Site control and containment. 3. Waste excavation and encapsulation. 4. Waste excavation, incineration, and encapsulation. 2 refs., 32 figs., 12 tabs.

  16. In situ applications of X ray fluorescence techniques. Final report of a coordinated research project 2000-2003

    International Nuclear Information System (INIS)

    In 2000 the IAEA initiated a Coordinated Research Project (CRP) on In Situ Applications of XRF Techniques as one of the elements of the project on Nuclear Instruments for Specific Applications, the major objective of which is to assist Member States in the development of nuclear instruments and software for special applications such as the characterization of materials. An overall objective of the CRP was to assist laboratories in Member States in such areas as environmental pollution monitoring, mineral exploration, the preservation of cultural heritage, the control of industrial processes and the optimization of analytical methodologies for these applications using field-portable X ray fluorescence (FPXRF). Although a significant amount of work has been undertaken in the development of FPXRF techniques, there is little consensus on the best approach for any particular application. The most important aspect before FPXRF techniques can be applied successfully is, therefore, the development of a clear FPXRF methodology. Because of the wide range of problems to which FPXRF can be applied, these procedures must be comprehensive and cover many applications involving the analysis of samples such as rocks, soils, air particulates or liquid samples. The specific research objectives of the CRP included the development and optimization of sampling methodologies for in situ XRF measurements, the improvement in the analytical performance of FPXRF based on the study of mineralogical effects, surface irregularity effects, heterogeneity and the influence of moisture content, the development and validation of quantitative and/or semi-quantitative procedures to be applied for in situ XRF analysis and development of complete operating procedures for selected in situ applications, including relevant quality assurance. The CRP covered a period of four years (2000?2003). Twelve laboratories from both developed and developing Member States and the IAEA?s Laboratories participated.This publication presents the results of the CRP. The IAEA officers responsible for the publication were A. Markowicz, D. Wegrzynek and K. Will of the Agency?s Laboratories, Seibersdorf. In the presented reports a summary of the work carried out by Member States and achievements at their laboratories related to the XRF and FPXRF techniques was given. The individual country reports are included in this publication. It was concluded that the participants carried out the research according to the agreed work plans and the objectives of the CRP were met. The following recommendations resulted from the CRP: Training courses in FPXRF analysis and in XRF data evaluation and interpretation are needed. Promotion of FPXRF spectrometry based on the advantages over other analytical techniques as applied for in situ soil analysis, geochemical prospecting, archaeometry and alloy identification is required. Regional Technical Cooperation projects are possible in order to improve implementation of XRF techniques in support of various areas of economy and development in the Member States. A database of certified standard reference materials applicable to XRF techniques is required. Development of dedicated FPXRF instruments for analysis of works of art and study of cultural heritage objects, environmental monitoring, etc., has to be continued. The Coordinated Research Project was very useful and cost effective. Therefore, further support of the XRF laboratories in Member States involved in research in the field of X ray fluorescence is required. Moreover, the uniqueness and potential applications of XRF techniques should be promoted. A new Coordinated Research Project in this field should be considered, e.g., focused on selected applications (such as environmental monitoring, archaeometry, material sciences or agriculture)

  17. Neutron capture gamma-ray technique for in situ mineral analysis

    International Nuclear Information System (INIS)

    The application of neutron capture gamma ray method for in situ analysis of mineral deposits is discussed. A borehole sonde for prompt gamma analysis (PGA) using a 3 Ci Americium-Berelium neutron source and a hyper pure germanium detector has been designed, constructed and evaluated. The evaluation program was designed to include neutron flux distribution in the simulated borehole, both experimentally and theoretically, response of the borehole sonde to elements of different concentrations and at different locations from the sonde, response of the sonde to dry borehole and to a water layer between the sonde and the borehole casing, and the response of the sonde to various elements in the matrix. The results indicate that the sonde is able to perform in situ multielement analysis for more than 20 elements. The extent of detection depends on elemental concentration and the other associated elements in the given matrix and to the water layer thickness between the sonde and the borehole casing. 39 refs

  18. Measurement techniques for in situ stresses around underground constructions in a deep clay formation

    OpenAIRE

    Li X.L.; Bastiaens W.; Areias L.; Verstricht J.

    2010-01-01

    Disposal in deep underground geological formations is internationally recognized as the most viable option for the long-term management of high-level radioactive waste. In Belgium, the Boom clay formation is extensively studied in this context, in particular at the 225 m deep HADES Underground Research Facility in Mol. A cost-effective design of deep underground structures requires an accurate assessment of the in situ stresses; a good estimation of these stresses is also essential when...

  19. Thermal stability and surface behaviors of CeO2/Si films during in-situ vacuum annealing

    Science.gov (United States)

    Luo, Lizhu; Chen, Jun; Wang, Xiaolin

    2014-12-01

    CeO2 thin films were deposited on Si (1 1 1) substrates by laser molecular-beam epitaxy (LMBE). The thermal stability and surface behaviors of CeO2/Si samples were investigated by X-ray photoelectron spectroscopy during in-situ vacuum annealing. Temperature dependency of surface compositions was identified. At the temperature from 700 K to 1000 K, CeO2 was reduced gradually, but incomplete transformation of CeO2 to Ce2O3 was found even when the sample was annealed at 1000 K for an hour. When the sample was exposed to oxygen ambience, the enhanced thermal stability of the partially reduced surface was revealed by the slight variation of Ce3d and Ce4d spectra. Si2p peak at 102.7 eV was detected on the top surface after the whole heating treatments, while not for the sub-surface during sputtering till to the interface. The Si signal at the outmost surface is induced by surface segregation due to the decreasing solid solubility of Si atoms in CeO2 matrix with the decreasing temperature. At the interface, Si2p peaks at 99.9 eV with the presence of Ce4d peaks at 122.2 eV and 125.6 eV are attributed to the formation of cerium silicates with Ce-Si-O matrix during annealing due to interfacial reactions, which are supposed to stabilize the partially reduced ceria system.

  20. Analysis to feature-based video stabilization/registration techniques within application of traffic data collection

    Science.gov (United States)

    Sadat, Mojtaba T.; Viti, Francesco

    2015-02-01

    Machine vision is rapidly gaining popularity in the field of Intelligent Transportation Systems. In particular, advantages are foreseen by the exploitation of Aerial Vehicles (AV) in delivering a superior view on traffic phenomena. However, vibration on AVs makes it difficult to extract moving objects on the ground. To partly overcome this issue, image stabilization/registration procedures are adopted to correct and stitch multiple frames taken of the same scene but from different positions, angles, or sensors. In this study, we examine the impact of multiple feature-based techniques for stabilization, and we show that SURF detector outperforms the others in terms of time efficiency and output similarity.

  1. Real-time stability in power systems techniques for early detection of the risk of blackout

    CERN Document Server

    Savulescu, Savu

    2014-01-01

    This pioneering volume has been updated and enriched to reflect the state-of-the-art in blackout prediction and prevention. It documents and explains background and algorithmic aspects of the most successful steady-state, transient and voltage stability solutions available today in real-time. It also describes new, cutting-edge stability applications of synchrophasor technology, and captures industry acceptance of metrics and visualization tools that quantify and monitor the distance to instability. Expert contributors review a broad spectrum of additionally available techniques, such as traje

  2. Field Deployment for In-situ Metal and Radionuclide Stabilization by Microbial Metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Turick, C. E.; Knox, A. S.; Dixon, K. L.; Roseberry, R. J.; Kritzas, Y. G

    2005-09-26

    A novel biotechnology is reported here that was demonstrated at SRS that facilitates metal and actinide immobilization by incorporating the physiology and ecology of indigenous bacteria. This technology is based on our previous work with pyomelanin-producing bacteria isolated from SRS soils. Through tyrosine supplementation, overproduction of pyomelanin was achieved, which lead ultimately to metal and actinide immobilization, both in-vitro and in-situ. Pyomelanin is a recalcitrant microbial pigment and a humic type compound in the class of melanin pigments. Pyomelanin has electron shuttling and metal chelation capabilities and thus accelerates the bacterial reduction and/or immobilization of metals. Pyomelanin is produced outside the cell and either diffuses away or attaches to the cell surface. In either case, the reduced pyomelanin is capable of transferring electrons to metals as well as chelating metals. Because of its recalcitrance and redox cycling properties, pyomelanin molecules can be used over and over again for metal transformation. When produced in excess, pyomelanin produced by one bacterial species can be used by other species for metal reduction, thereby extending the utility of pyomelanin and further accelerating metal immobilization rates. Soils contaminated with Ni and U were the focus of this study in order to develop in-situ, metal bioimmobilization technologies. We have demonstrated pyomelanin production in soil from the Tims Branch area of SRS as a result of tyrosine amendments. These results were documented in laboratory soil column studies and field deployment studies. The amended soils demonstrated increased redox behavior and sequestration capacity of U and transition metals following pyomelanin production. Treatments incorporating tyrosine and lactate demonstrated the highest levels of pyomelanin production. In order to determine the potential use of this technology at other areas of SRS, pyomelanin producing bacteria were also quantified from metal contaminated soils at TNX and D areas of SRS. A bacterial culture collection from subsurface studies near P Area of SRS were also evaluated for pyomelanin production. Bacterial densities of pyomelanin producers were determined to be >10{sup 6} cells/g soil at TNX and D areas. In addition, approximately 25% of isolates from P area demonstrated pyomelanin production in the presence of tyrosine. Biogeochemical activity is an ongoing and dynamic process due, in part, to bacterial activity in the subsurface. Bacteria contribute significantly to biotransformation of metals and radionuclides. An understanding and application of the mechanisms of metal and radionuclide reduction offers tremendous potential for development into bioremedial processes and technologies. This report demonstrates the application of recent advances in bacterial physiology and soil ecology for future bioremediation activities involving metal and actinide immobilization.

  3. A comprehensive approach for the assessment of in-situ pavement density using GPR technique

    Science.gov (United States)

    Plati, Christina; Georgiou, Panos; Loizos, Andreas

    2013-04-01

    Proper construction of the asphalt pavement is a prerequisite to developing a long lasting roadway that does not require extensive future maintenance. This goal is achieved by verifying that design specifications are met through the use of quality assurance (QA) practices. The in-situ density is regarded as one of the most important controls used to ensure that a pavement being placed is of high quality because it is a good indicator of future performance. In-situ density is frequently assessed utilizing one or more of the following three methods: cores, nuclear density gauge measurements or non-nuclear density gauge measurements. Each of the above mentioned methods, however, have their distinct disadvantages. Cores, for example, are generally considered to be the most accurate means of measuring in-situ density, however, they are a time consuming and destructive test that introduces a defect into asphalt pavements. Because of the destructive nature associated with coring, contractors and agencies have alternatively used non-destructive nuclear and non-nuclear density gauges for quality control purposes. These instruments allow for a more rapid assessment of the in-situ density, allowing measurements to be taken even during the pavement's construction. The disadvantage of these gauges are that they provide density readings only at discrete locations of the asphalt pavement mat, while no consensus exists among pavement researchers on the proper correlation between the gauges and core density. In recent years, numerous alternative methods have been introduced for the assessment of in-situ density, both during asphalt pavement construction and afterwards. These methods include, amongst others, intelligent compaction, thermal imaging and ground penetrating radar (GPR). Among these methods, GPR has been defined as both a technically feasible and promising method for the nondestructive, rapid, and continuous evaluation of in-situ asphalt pavement density based on electromagnetic mixing (EM) theory, through the utilization of proper models. These models enable the prediction of asphalt mixture density dependent on its bulk dielectric constant as measured by the GPR, the dielectric properties of the asphalt mix materials, as well as other material information. The goal of the present study is to attempt to verify the prediction performance of various density models. To accomplish this goal GPR surveys were carried out in the field during asphalt pavement construction to evaluate the density results due to different compaction modes. The GPR data was analyzed to calculate the appropriate asphalt mix dielectric properties needed for the activation of the considered density prediction models. Predicted densities were compared with densities of the field cores extracted from the as-built asphalt pavement prior to trafficking. It was found that the predicted density values were significantly lower when compared to the ground truth data. A further investigation of the effect of temperature on GPR readings showed that GPR seems to overestimate the in-situ density. However, this approach could be used effectively to evaluate the performance of different compaction methods and set up the compaction pattern that is needed to achieve the desired asphalt pavement density.

  4. In Situ Stability of Substrate-Associated Cellulases Studied by DSC

    DEFF Research Database (Denmark)

    Borch, Kim; Cruys-Bagger, Nicolaj

    2014-01-01

    This work shows that differential scanning calorimetry (DSC) can be used to monitor the stability of substrate-adsorbed cellulases during long-term hydrolysis of insoluble cellulose. Thermal transitions of adsorbed enzyme were measured regularly in subsets of a progressing hydrolysis, and the size of the transition peak was used as a gauge of the population of native enzyme. Analogous measurements were made for enzymes in pure buffer. Investigations of two cellobiohydrolases, Cel6A and Cel7A, from Trichoderma reesei, which is an anamorph of the fungus Hypocrea jerorina, showed that these enzymes were essentially stable at 25 °C. Thus, over a 53 h experiment, Cel6A lost less than 15% of the native population and Cel7A showed no detectable loss for either the free or substrate-adsorbed state. At higher temperatures we found significant losses in the native populations, and at the highest tested temperature (49 °C) about 80% Cel6A and 35% of Cel7A was lost after 53 h of hydrolysis. The data consistently showed that Cel7A was more long-term stable than Cel6A and that substrate-associated enzyme was less long-term stable than enzyme in pure buffer stored under otherwise equal conditions. There was no correlation between the intrinsic stability, specified by the transition temperature in the DSC, and the long-term stability derived from the peak area. The results are discussed with respect to the role of enzyme denaturation for the ubiquitous slowdown observed in the enzymatic hydrolysis of cellulose.

  5. Crack-tip degradation processes observed during in situ cyclic fatigue of partially stabilized zirconia

    International Nuclear Information System (INIS)

    It is proposed that reduced transformation zone widths in Mg-PSZ in cyclically versus critically propagated cracks are due to reductions in the crack-tip toughness, consistent with an intrinsic cyclic fatigue mechanism. Cyclic fatigue crack growth in Mg-PSZ was observed in situ in a SEM. Following cyclic fatigue, the samples were critically broken and the fracture surfaces observed. Extensive crack bridging by the precipitate phase was observed near the crack tip, and it is proposed that this crack bridging significantly affects the material's intrinsic toughness. Frictional degradation of the precipitate bridges occurs during cyclic loading and hence reduces the critical crack-tip stress intensity factors for crack propagation. Reductions in the critical crack-tip stress intensity factors also lead to reductions in the transformation zone widths during cyclic loading and hence the level of crack-tip shielding caused by phase transformation. This appears to be the mechanism of cyclic fatigue. A degree of uncracked ligament bridging was also observed and is linked with the frequency of random large precipitates. However, analysis shows that its effect upon crack growth rates under cyclic load is limited

  6. Design of top covers supporting aerobic in situ stabilization of old landfills – An experimental simulation in lysimeters

    International Nuclear Information System (INIS)

    Highlights: ? Tested engineered covers as surrogate to gas extraction during and after in situ aeration. ? Examined how covers influence gas emissions, water balance and leachate generation. ? Investigated effect of top covers on air-distribution in waste mass during aeration. ? We suggest criteria and cover design to meet the demands during and after aeration. ? Such cover systems may offer greenhouse gas emission reduction also after active aeration. - Abstract: Landfill aeration by means of low pressure air injection is a promising tool to reduce long term emissions from organic waste fractions through accelerated biological stabilization. Top covers that enhance methane oxidation could provide a simple and economic way to mitigate residual greenhouse gas emissions from in situ aerated landfills, and may replace off-gas extraction and treatment, particularly at smaller and older sites. In this respect the installation of a landfill cover system adjusted to the forced-aerated landfill body is of great significance. Investigations into large scale lysimeters (2 × 2 × 3 m) under field conditions have been carried out using different top covers including compost materials and natural soils as a surrogate to gas extraction during active low pressure aeration. In the present study, the emission behaviour as well as the water balance performance of the lysimeters has been investigated, both prior to and during the first months of in situ aeration. Results reveal that mature sewage sludge compost (SSC) placed in one lysimeter exhibits in principle optimal ambient conditions for methanotrophic bacteria to enhance methane oxidation. Under laboratory conditions the mature compost mitigated CH4 loadings up to 300 l CH4/m2 d. In addition, the compost material provided high air permeability even at 100% water holding capacity (WHC). In contrast, the more cohesive, mineral soil cover was expected to cause a notably uniform distribution of the injected air within the waste layer. Laboratory results also revealed sufficient air permeability of the soil materials (TS-F and SS-Z) placed in lysimeter C. However, at higher compaction density SS-Z became impermeable at 100% WHC. Methane emissions from the reference lysimeter with the smaller substrate cover (12–52 g CH4/m2 d) were significantly higher than fluxes from the other lysimeters (0–19 g CH4/m2 d) during in situ aeration. Regarding water balance, lysimeters covered with compost and compost-sand mixture, showed the lowest leachate rate (18–26% of the precipitation) due to the high water holding capacity and more favourable plant growth conditions compared to the lysimeters with mineral, more cohesive, soil covers (27–45% of the precipitation). On the basis of these results, the authors suggest a layered top cover system using both compost material as well as mineral soil in order to support active low-pressure aeration. Conventional soil materials with lower permeability may be used on top of the landfill body for a more uniform aeration of the waste due to an increased resistance to vertical gas flow. A compost cover may be built on top of the soil cover underlain by a gas distribution layer to improve methane oxidation rates and minimise water infiltration. By planting vegetation with a high transpiration rate, the leachate amount emanating from the landfill could be further minimised. The suggested design may be particularly suitable in combination with intermittent in situ aeration, in the later stage of an aeration measure, or at very small sites and shallow deposits. The top cover system could further regulate water infiltration into the landfill and mitigate residual CH4 emissions, even beyond the time of active aeration.

  7. Vane coupling rings: a simple technique for stabilizing a four-vane radiofrequency quadrupole structure

    International Nuclear Information System (INIS)

    The benefits of stabilized accelerating structures, with regard to the manufacture and operation, have been well documented. The four-vane radiofrequency quadrupoles (RFQ) presently being designed and constructed in many laboratories are not stabilized because of the weak electromagnetic coupling between the quadrant resonators. This paper presents a simple technique developed at the Lawrence Berkeley Laboratory using vane coupling rings (VCR's) which azimuthally stabilize the RFQ structure and greatly enhance its use as a practical accelerator. In particular, the VCR's: completely eliminate the dipole modes in the frequency range of interest; provide adequate quadrant balance with an initial precision mechanical alignment of the vanes; and enhance axial balance and simplify end tuners. Experimental verification tests on a scale model are discussed

  8. Optical vernier technique for in-situ measurement of the length of long Fabry-Perot cavities

    CERN Document Server

    Rakhmanov, M; Yamamoto, H

    1999-01-01

    We propose a method for in-situ measurement of the length of kilometer size Fabry-Perot cavities in laser gravitational wave detectors. The method is based on the vernier, which occurs naturally when the laser incident on the cavity has a sideband. By changing the length of the cavity over several wavelengths we obtain a set of carrier resonances alternating with sideband resonances. From the measurement of the separation between the carrier and a sideband resonance we determine the length of the cavity. We apply the technique to the measurement of the length of a Fabry-Perot cavity in the Caltech 40m Interferometer and discuss the accuracy of the technique.

  9. In Situ Microbial Community Control of the Stability of Bio-reduced Uranium

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, Brett, R.; Peacock, Aaron, D.; Resch, Charles, T.; Arntzen, Evan; Smithgall, Amanda, N.; Pfiffner, Susan; Gan, M.; McKinley, James, P.; Long, Philip, E.; White, David, C.

    2008-03-28

    In aerobic aquifers typical of many Department of Energy (DOE) legacy waste sites, uranium is present in the oxidized U(VI) form which is more soluble and thus more mobile. Field experiments at the Old Rifle UMTRA site have demonstrated that biostimulation by electron donor addition (acetate) promotes biological U(VI) reduction (2). However, U(VI) reduction is reversible and oxidative dissolution of precipitated U(IV) after the cessation of electron donor addition remains a critical issue for the application of biostimulation as a treatment technology. Despite the potential for oxidative dissolution, field experiments at the Old Rifle site have shown that rapid reoxidation of bio-reduced uranium does not occur and U(VI) concentrations can remain at approximately 20% of background levels for more than one year. The extent of post-amendment U(VI) removal and the maintenance of bioreduced uranium may result from many factors including U(VI) sorption to iron-containing mineral phases, generation of H2S or FeS0.9, or the preferential sorption of U(VI) by microbial cells or biopolymers, but the processes controlling the reduction and in situ reoxidation rates are not known. To investigate the role of microbial community composition in the maintenance of bioreduced uranium, in-well sediment incubators (ISIs) were developed allowing field deployment of amended and native sediments during on-going experiments at the site. Field deployment of the ISIs allows expedient interrogation of microbial community response to field environmental perturbations and varying geochemical conditions.

  10. In Situ Microbial Community Control of the Stability of Bio-reduced Uranium

    International Nuclear Information System (INIS)

    In aerobic aquifers typical of many Department of Energy (DOE) legacy waste sites, uranium is present in the oxidized U(VI) form which is more soluble and thus more mobile. Field experiments at the Old Rifle UMTRA site have demonstrated that biostimulation by electron donor addition (acetate) promotes biological U(VI) reduction (2). However, U(VI) reduction is reversible and oxidative dissolution of precipitated U(IV) after the cessation of electron donor addition remains a critical issue for the application of biostimulation as a treatment technology. Despite the potential for oxidative dissolution, field experiments at the Old Rifle site have shown that rapid reoxidation of bio-reduced uranium does not occur and U(VI) concentrations can remain at approximately 20% of background levels for more than one year. The extent of post-amendment U(VI) removal and the maintenance of bioreduced uranium may result from many factors including U(VI) sorption to iron-containing mineral phases, generation of H2S or FeS0.9, or the preferential sorption of U(VI) by microbial cells or biopolymers, but the processes controlling the reduction and in situ reoxidation rates are not known. To investigate the role of microbial community composition in the maintenance of bioreduced uranium, in-well sediment incubators (ISIs) were developed allowing field deployment of amended and native sediments during on-going experiments at the site. Field deployment of the ISIs allows expedient interrogation of microbial community response to field environmental perturbations and varying geochemical conditions.

  11. Actively stabilized optical fiber interferometry technique for online/in-process surface measurement

    International Nuclear Information System (INIS)

    In this paper, we report the recent progress in optical-beam scanning fiber interferometry for potential online nanoscale surface measurement based on the previous research. It attempts to generate a robust and miniature measurement device for future development into a multiprobe array measurement system. In this research, both fiber-optic-interferometry and the wavelength-division-multiplexing techniques have been used, so that the optical probe and the optical interferometer are well spaced and fast surface scanning can be carried out, allowing flexibility for online measurement. In addition, this system provides a self-reference signal to stabilize the optical detection with high common-mode noise suppression by adopting an active phase tracking and stabilization technique. Low-frequency noise was significantly reduced compared with unstabilized result. The measurement of a sample surface shows an attained repeatability of 3.3 nm

  12. Cu-Ti Formation in Nb-Ti/Cu Superconducting Strand Monitored by in situ Techniques

    CERN Document Server

    Pong, I; Pong, Ian; Gerardin, Alexandre; Scheuerlein, Christian; Bottura, Luca

    2010-01-01

    In order to investigate the high temperature exposure effect on Nb-Ti/Cu superconducting strands, as might be encountered in joining by soldering and in cabling annealing, X-ray diffraction and resistometry measurements were performed in situ during heat treatment, and complemented by conventional metallography, mechanical tests and superconducting properties measurements. Changes of the Nb-Ti nanostructure at temperatures above 300 degrees C are manifested in the degradation of critical current in an applied external magnetic field, although degradation at self field was insignificant up to 400 degrees C for several minutes. Above 500 degrees C, the formation of various Cu-Ti intermetallic compounds, due to Ti diffusion from Nb-Ti into Cu, is detected by in situ XRD albeit not resolvable by SEM-EDS. There is a ductile to brittle transition near 600 degrees C, and liquid formation is observed below 900 degrees C. The formation of Cu-Ti causes a delayed reduction of the residual resistivity ratio (RRR) and adv...

  13. Optical In-Situ Plasma Process Monitoring Technique for Detection of Abnormal Plasma Discharge

    Directory of Open Access Journals (Sweden)

    Sang Jeen Hong

    2013-04-01

    Full Text Available Advanced semiconductor manufacturing technology requires methods to maximize tool efficiency and improveproduct quality by reducing process variability. Real-time plasma process monitoring and diagnosis have becomecrucial for fault detection and classification (FDC and advanced process control (APC. Additional sensors mayincrease the accuracy of detection of process anomalies, and optical monitoring methods are non-invasive. In thispaper, we propose the use of a chromatic data acquisition system for real-time in-situ plasma process monitoringcalled the Plasma Eyes Chromatic System (PECS. The proposed system was initially tested in a six-inch researchtool, and it was then further evaluated for its potential to detect process anomalies in an eight-inch production toolfor etching blanket oxide films. Chromatic representation of the PECS output shows a clear correlation with smallchanges in process parameters, such as RF power, pressure, and gas flow. We also present how the PECS may beadapted as an in-situ plasma arc detector. The proposed system can provide useful indications of a faulty process in atimely and non-invasive manner for successful run-to-run (R2R control and FDC.

  14. Arthroscopic stabilization of the shoulder for acute primary dislocations using a transglenoid suture technique.

    Science.gov (United States)

    Salmon, J M; Bell, S N

    1998-03-01

    Many studies report the results of arthroscopic stabilization for recurrent shoulder instability, with widely variable recurrence rates; however, there are very few reports of the use of these techniques in acute first-time dislocations. We report the clinical outcomes of 17 patients who had arthroscopic stabilization using a transglenoid suture technique for acute primary dislocation. The surgery took place between March 1992 and March 1994 and, to date, there has been one recurrent dislocation (6%) and no recurrent subluxation. There were no major complications, although a number of patients found the knot tied over the infraspinatus fascia to be uncomfortable until it resorbed. All patients examined had normal power and range of motion, and a clinically stable shoulder. All 16 patients without recurrence were satisfied with their result. Nine patients returned to sports at the same or higher level, including such vigorous contact sports as Australian Rules football and rugby. Three patients did not return to the same level of sporting activity because of lack of confidence in the shoulder or a fear of dislocation despite no clinical evidence of instability. Five patients reported a lack of confidence in the shoulder without clinical evidence of instability. We suggest that arthroscopic stabilization with transglenoid sutures or a suture anchor technique is a reasonable option for the athlete with an acute primary shoulder dislocation who wishes to return to sports. PMID:9531124

  15. Ambient in-situ immersion freezing measurements - findings from the ZAMBIS 2014 field campaign for three ice nucleation techniques

    Science.gov (United States)

    Kohn, Monika; Atkinson, James D.; Lohmann, Ulrike; Kanji, Zamin A.

    2015-04-01

    To estimate the influence of clouds on the Earth's radiation budget, it is crucial to understand cloud formation processes in the atmosphere. A key process, which significantly affects cloud microphysical properties and the initiation of precipitation thus contributing to the hydrological cycle, is the prevailing type of ice nucleation mechanism. In mixed-phase clouds immersion freezing is the dominant ice crystal forming mechanism, whereby ice nucleating particles (INP) first act as cloud condensation nuclei (CCN) and are activated to cloud droplets followed by freezing upon supercooling. There are a number of experimental methods and techniques to investigate the ice nucleating ability in the immersion mode, however most techniques are offline for field sampling or only suitable for laboratory measurements. In-situ atmospheric studies are needed to understand the ice formation processes of 'real world' particles. Laboratory experiments simulate conditions of atmospheric processes like ageing or coating but are still idealized. Our method is able to measure ambient in-situ immersion freezing on single immersed aerosol particles. The instrumental setup consists of the recently developed portable immersion mode cooling chamber (PIMCA) as a vertical extension to the portable ice nucleation chamber (PINC, [1]), where the frozen fraction of activated aerosol particles are detected by the ice optical depolarization detector (IODE, [2]). Two additional immersion freezing techniques based on a droplet freezing array [3,4] are used to sample ambient aerosol particles either in a suspension (fraction larger ~0.6 ?m) or on PM10-filters to compare different ice nucleation techniques. Here, we present ambient in-situ measurements at an urban forest site in Zurich, Switzerland held during the Zurich ambient immersion freezing study (ZAMBIS) in spring 2014. We investigated the ice nucleating ability of natural atmospheric aerosol with the PIMCA/PINC immersion freezing setup as well as a droplet freezing method on aerosol particles either collected in a suspension or on PM10-filters to obtain atmospheric IN concentrations based on the measured ambient aerosol. Investigation of physical properties (number and size distribution) and chemical composition as well as the meteorological conditions provide supplementary information that help to understand the nature of particles and air masses that contribute to immersion freezing. Acknowledgements We thank Hannes Wydler and Hansjörg Frei from ETH Zurich for their technical support. Furthermore, the authors want thank Franz Conen from the University of Basel for sharing equipment and training in the drop freezing experiment. References [1] Chou et al. (2011), Atmos. Chem. Phys., 11, 4725-4738. [2] Nicolet et al. (2010), Atmos. Chem. Phys., 10, 313-325. [3] Conen et al. (2012), Atmos. Meas. Tech., 5, 321-327. [4] Stopelli et al. (2014), Atmos. Meas. Tech., 7, 129-134.

  16. In situ electrical characterization of palladium-based single electron transistors made by electromigration technique

    International Nuclear Information System (INIS)

    We report the fabrication of single electron transistors (SETs) by feedback-controlled electromigration of palladium and palladium-nickel alloy nanowires. We have optimized a gradual electromigration process for obtaining devices consisting of three terminals (source, drain and gate electrodes), which are capacitively coupled to a metallic cluster of nanometric dimensions. This metal nanocluster forms into the inter-electrode channel during the electromigration process and constitutes the active element of each device, acting as a quantum dot that rules the electron flow between source and drain electrodes. The charge transport of the as-fabricated devices shows Coulomb blockade characteristics and the source to drain conductance can be modulated by electrostatic gating. We have thus achieved the fabrication and in situ measurement of palladium-based SETs inside a liquid helium cryostat chamber

  17. Facile production of stable silicon nanoparticles: laser chemistry coupled to in situ stabilization via room temperature hydrosilylation

    Science.gov (United States)

    Malumbres, A.; Martínez, G.; Hueso, J. L.; Gracia, J.; Mallada, R.; Ibarra, A.; Santamaría, J.

    2015-04-01

    Stable, alkyl-terminated, light-emitting silicon nanoparticles have been synthesized in a continuous process by laser pyrolysis of a liquid trialkyl-silane precursor selected as a safer alternative to gas silane (SiH4). Stabilization was achieved by in situ reaction using a liquid collection system instead of the usual solid state filtration. The alkene contained in the collection liquid (1-dodecene) reacted with the newly formed silicon nanoparticles in an unusual room-temperature hydrosilylation process. It was achieved by the presence of fluoride species, also produced during laser pyrolysis from the decomposition of sulfur hexafluoride (SF6) selected as a laser sensitizer. This process directly rendered alkyl-passivated silicon nanoparticles with consistent morphology and size (SF6) selected as a laser sensitizer. This process directly rendered alkyl-passivated silicon nanoparticles with consistent morphology and size (<3 nm), avoiding the use of costly post-synthetic treatments. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr01031d

  18. Ultrasonic techniques for the in situ characterisation of 'legacy' Waste sludges and dispersions - 59111

    International Nuclear Information System (INIS)

    Research being undertaken at the University of Leeds, as part of the DIAMOND university consortium, is exploring the effectiveness of various ultrasonic technologies as in situ probes to characterize and monitor nuclear waste slurries, such as the 'Legacy' Magnesium hydroxide sludges found in Sellafield, U.K. Through use of a commercial Acoustic Backscatter Sensor (ABS) with 1 - 5 MHz transducers, various properties of free-settling oxide simulant sludges were determined. Work was focused upon characterizing essentially 'static' sludges (to give prospective use as tools for the wastes in current deposits); although, the sensors also have potential as dispersion monitors during any future processing and storage of the Legacy wastes, as well as many other storage, clarifier or thickener systems across a wide range of industrial processing operations. ABS data of mixed glass powder dispersions was analysed and compared to scattering theory, to understand the correlations between acoustic attenuation and particulate concentration. The ABS was also calibrated to measure changes in average particulate concentration within a settling suspension over time, and showed the depth-wise segregation of the dispersion through the settling column at different particular time intervals. It was found that observed hindered settling also led to an increase in particulate concentration over the sludge zone and significant segregation occurred at moderate time intervals, due to the broad size distribution of the aggregates measured. It is hoped in future that these sensors may be able to be fitted to robotic handlers that have been installed onsite (and previously used for sampling), allowing fully automatic in situ sludge analysis. (authors)

  19. Novel XRD technique and equipment for in-situ monitoring of phase transformations in lithium batteries during cycling

    International Nuclear Information System (INIS)

    Full text: Safe, rechargeable batteries utilising a lithium metal electrode have not been realised due to phenomena, which occur on the lithium surface during the cycling of a battery. Lithium ion conduction inhomogeneities through the surface film give rise to uneven deposition of lithium, which can result in short circuits. The large potential increase in energy density that the use of the lithium electrode represents makes the nature of the surface film of interest to battery researchers. The lithium surface is highly reactive, particularly in the case of electrodes with a rough surface deposit. This presents difficulties to researchers hoping to obtain representative measurements of the lithium surface and requires the use of environmental sample chambers and in-situ techniques. X-ray diffraction techniques have been used to probe changes in cathode materials (typically transition metal oxides) for lithium batteries, but to our knowledge has not been successfully used to study changes taking place on the lithium surface during cycling. We present early results from work we have undertaken to develop a technique for characterising the surface film on lithium battery electrodes. The instrumentation was set-up as follows. An XRD was fitted with an INEL CPS 120 position sensitive detector (PSD), multilayer mirror and environmental chamber. The latter was specially developed in our laboratory for the purpose of these experiments. The lithium cells were sealed in laminated foil. Cycled and uncycled cells were investigated. Different radiation sources were used (Cu, Co and Cr). The in-situ measurements aiming at monitoring the phase transitions of cycled/uncycled cells at different angles (including grazing angles) in time were carried out in both transmission and reflection mode. Copyright (2002) Australian X-ray Analytical Association Inc

  20. Design of top covers supporting aerobic in situ stabilization of old landfills--an experimental simulation in lysimeters.

    Science.gov (United States)

    Hrad, Marlies; Huber-Humer, Marion; Wimmer, Bernhard; Reichenauer, Thomas G

    2012-12-01

    Landfill aeration by means of low pressure air injection is a promising tool to reduce long term emissions from organic waste fractions through accelerated biological stabilization. Top covers that enhance methane oxidation could provide a simple and economic way to mitigate residual greenhouse gas emissions from in situ aerated landfills, and may replace off-gas extraction and treatment, particularly at smaller and older sites. In this respect the installation of a landfill cover system adjusted to the forced-aerated landfill body is of great significance. Investigations into large scale lysimeters (2 × 2 × 3m) under field conditions have been carried out using different top covers including compost materials and natural soils as a surrogate to gas extraction during active low pressure aeration. In the present study, the emission behaviour as well as the water balance performance of the lysimeters has been investigated, both prior to and during the first months of in situ aeration. Results reveal that mature sewage sludge compost (SSC) placed in one lysimeter exhibits in principle optimal ambient conditions for methanotrophic bacteria to enhance methane oxidation. Under laboratory conditions the mature compost mitigated CH(4) loadings up to 300 lCH(4)/m(2)d. In addition, the compost material provided high air permeability even at 100% water holding capacity (WHC). In contrast, the more cohesive, mineral soil cover was expected to cause a notably uniform distribution of the injected air within the waste layer. Laboratory results also revealed sufficient air permeability of the soil materials (TS-F and SS-Z) placed in lysimeter C. However, at higher compaction density SS-Z became impermeable at 100% WHC. Methane emissions from the reference lysimeter with the smaller substrate cover (12-52 g CH(4)/m(2)d) were significantly higher than fluxes from the other lysimeters (0-19 g CH(4)/m(2)d) during in situ aeration. Regarding water balance, lysimeters covered with compost and compost-sand mixture, showed the lowest leachate rate (18-26% of the precipitation) due to the high water holding capacity and more favourable plant growth conditions compared to the lysimeters with mineral, more cohesive, soil covers (27-45% of the precipitation). On the basis of these results, the authors suggest a layered top cover system using both compost material as well as mineral soil in order to support active low-pressure aeration. Conventional soil materials with lower permeability may be used on top of the landfill body for a more uniform aeration of the waste due to an increased resistance to vertical gas flow. A compost cover may be built on top of the soil cover underlain by a gas distribution layer to improve methane oxidation rates and minimise water infiltration. By planting vegetation with a high transpiration rate, the leachate amount emanating from the landfill could be further minimised. The suggested design may be particularly suitable in combination with intermittent in situ aeration, in the later stage of an aeration measure, or at very small sites and shallow deposits. The top cover system could further regulate water infiltration into the landfill and mitigate residual CH(4) emissions, even beyond the time of active aeration. PMID:22749719

  1. IN-SITU CHEMICAL STABILIZATION OF METALS AND RADIONUCLIDES THROUGH ENHANCED ANAEROBIC REDUCTIVE PRECIPITATION

    Energy Technology Data Exchange (ETDEWEB)

    Christopher C. Lutes; Angela Frizzell, PG; Todd A. Thornton; James M. Harrington

    2003-08-01

    The objective of this NETL sponsored bench-scale study was to demonstrate the efficacy of enhanced anaerobic reductive precipitation (EARP) technology for precipitating uranium using samples from contaminated groundwater at the Fernald Closure Project (FCP) in Cincinnati, Ohio. EARP enhances the natural biological reactions in the groundwater through addition of food grade substrates (typically molasses) to drive the oxidative-reductive potential of the groundwater to a lower, more reduced state, thereby precipitating uranium from solution. In order for this in-situ technology to be successful in the long term, the precipitated uranium must not be re-dissolved at an unacceptable rate once groundwater geochemical conditions return to their pretreatment, aerobic state. The approach for this study is based on the premise that redissolution of precipitated uranium will be slowed by several mechanisms including the presence of iron sulfide precipitates and coatings, and sorption onto fresh iron oxides. A bench-scale study of the technology was performed using columns packed with site soil and subjected to a continuous flow of uranium-contaminated site groundwater (476 {micro}g/L). The ''treated'' column received a steady stream of dilute food grade molasses injected into the contaminated influent. Upon attainment of a consistently reducing environment and demonstrated removal of uranium, an iron sulfate amendment was added along with the molasses in the influent solution. After a month long period of iron addition, the treatments were halted, and uncontaminated, aerobic, unamended water was introduced to the treated column to assess rebound of uranium concentrations. In the first two months of treatment, the uranium concentration in the treated column decreased to the clean-up level (30 {micro}g/L) or below, and remained there for the remainder of the treatment period. A brief period of resolubilization of uranium was observed as the treated column returned to aerobic conditions, but the concentration later returned to below the clean-up level. Speciation analysis was conducted on soil collected from the treated column after rebound testing. The experimental results show that: (a) The mass of uranium resolubilized in more than four months of column testing was much lower than the amount precipitated. (b) The majority of the uranium was precipitated in the first few inches of the treated column. The majority of the uranium precipitated was associated with iron oxides or in other immobile/sequestered phases. It is important to contrast this result with the results reported by Bryan (2003) who shows that most of the uranium associated with contaminated aquifer solids at Fernald under the existing natural attenuation/pump and treat with reinjection conditions is carbonate bound. Carbonate bound forms are traditionally seen as fairly mobile, but may not be under a calcite/dolomite saturated condition. Fernald is currently conducting further studies to investigate the mobility of the carbonate bound forms. (c) Though reoxidation concentrations from the bench-scale column exceeded 30 {micro}g/L for a time, they later returned to below this value. Effluent concentrations from the treated column are expected to over predict full-scale concentrations for reasons discussed in depth in the text. Finally, these results must be viewed in light of the site's ongoing pump-and-treat with reinjection system. There is reason to believe that although the pump-and-treat technology is currently effectively controlling the uranium plume and reducing the groundwater concentration, it may not be able to reach the treatment standard of 30 {micro}g/L within an economical operating lifetime and then maintain that concentration without rebound. This study suggests that Enhanced Anaerobic Reductive Precipitation can change the speciation and thus reduce the mobility of uranium at the site and expedite closure.

  2. Comparación de las técnicas in situ, in vitro y enzimática (celulasa) para estimar la digestibilidad de forrajes en ovinos / Comparison of the in situ, in vitro and Enzimatic (Cellulase) Techniques for Digestibility Estimation of Forages in Sheep

    Scientific Electronic Library Online (English)

    Giovanna, Torres G.; Teresa, Arbaiza F.; Fernando, Carcelén C.; Orlando, Lucas A..

    Full Text Available Se comparó los resultados de las técnicas in vitro, in situ y enzimática (celulasa) para estimar la digestibilidad de forrajes de diferente calidad nutritiva en ovinos. Se colectó muestras de forraje de tres calidades: alta (rye grass de 2-4 semanas), media (rye grass de 8 semanas y heno de alfalfa) [...] y baja (paja de avena). Las muestras fueron secadas, molidas y pasaron por tamiz de 1 mm para la técnica in vitro y celulasa y 3 mm para la técnica in situ. Se determinó la digestibilidad in vitro de la materia seca (DIVMS), digestibilidad in situ de la materia seca (DISMS) y digestibilidad a la celulasa de la materia seca (DCMS). Se emplearon tres ovinos con fístula ruminal y alimentados con maíz forrajero y heno de alfalfa. Se usó un diseño experimental con arreglo factorial de 4 x 3 (4 calidades de forraje y 3 técnicas). La DISMS fue superior (p Abstract in english The objective of the study was to compare the efficiency of the in situ, in vitro and enzymatic (cellulose) techniques in estimating the digestibility of forage with different nutritional quality in sheep. Samples of three qualities of forage were collected: high (rye grass of 2-4 weeks), medium (ry [...] e grass of 8 weeks and alfalfa hay), and low (oat straw). The samples were dried, grounded and passed through 1 mm sieve for the in vitro and cellulose technique and 3 mm sieve for the in situ technique. The in vitro digestibility of dry matter (IVDDM), in situ digestibility of dry matter (ISDDM), and cellulose digestibility of dry matter (CDDM) were determined. Three adult rams with ruminal fistula and fed with a diet based on alfalfa hay and corn stalk. A complete randomized 4 x 3 experimental design (4 quality forages and 3 techniques) was used. The ISDDM was higher (p

  3. Use of Sensitive and Specific Biomolecular and Mass Spectrometric Techniques to Monitor the Performance of In-Situ Hydrocarbon Biodegradation

    Science.gov (United States)

    Beller, H. R.; Kane, S. R.; Legler, T. C.

    2008-12-01

    Monitored natural attenuation (MNA) can be a cost-effective and viable approach for remediation of hydrocarbon-contaminated groundwater. However, regulatory acceptance of the approach is often contingent on monitoring that can convincingly demonstrate the role of microbial degradation. Recent advances in anaerobic hydrocarbon biochemistry, analytical chemistry, and molecular biology have fostered the development of powerful techniques that can be applied to MNA of BTEX (benzene, toluene, ethylbenzene, and xylenes). Here, I discuss two independent methods that have been developed to monitor in situ, anaerobic biodegradation of toluene and xylenes. A method has been developed for rapid, sensitive, and highly selective detection of distinctive indicators of anaerobic alkylbenzene metabolism. The target metabolites, benzylsuccinic acid and methylbenzylsuccinic acid isomers, have no known sources other than anaerobic toluene or xylene degradation; thus, their mere presence in groundwater provides definitive evidence of in situ metabolism. The method, which involves small sample size ( 7 orders of magnitude. Application of these two methods in field studies will be discussed in the context of the methods' strengths and limitations. Field data will include a side-by-side comparison of the two methods during a controlled release of BTX and ethanol, simulating release of gasohol from a leaking underground storage tank.

  4. In situ NMR and electrochemical quartz crystal microbalance techniques reveal the structure of the electrical double layer in supercapacitors

    Science.gov (United States)

    Griffin, John M.; Forse, Alexander C.; Tsai, Wan-Yu; Taberna, Pierre-Louis; Simon, Patrice; Grey, Clare P.

    2015-08-01

    Supercapacitors store charge through the electrosorption of ions on microporous electrodes. Despite major efforts to understand this phenomenon, a molecular-level picture of the electrical double layer in working devices is still lacking as few techniques can selectively observe the ionic species at the electrode/electrolyte interface. Here, we use in situ NMR to directly quantify the populations of anionic and cationic species within a working microporous carbon supercapacitor electrode. Our results show that charge storage mechanisms are different for positively and negatively polarized electrodes for the electrolyte tetraethylphosphonium tetrafluoroborate in acetonitrile; for positive polarization charging proceeds by exchange of the cations for anions, whereas for negative polarization, cation adsorption dominates. In situ electrochemical quartz crystal microbalance measurements support the NMR results and indicate that adsorbed ions are only partially solvated. These results provide new molecular-level insight, with the methodology offering exciting possibilities for the study of pore/ion size, desolvation and other effects on charge storage in supercapacitors.

  5. Development of laser-based techniques for in situ characterization of the first wall in ITER and future fusion devices

    International Nuclear Information System (INIS)

    Analysis and understanding of wall erosion, material transport and fuel retention are among the most important tasks for ITER and future devices, since these questions determine largely the lifetime and availability of the fusion reactor. These data are also of extreme value to improve the understanding and validate the models of the in vessel build-up of the T inventory in ITER and future D–T devices. So far, research in these areas is largely supported by post-mortem analysis of wall tiles. However, access to samples will be very much restricted in the next-generation devices (such as ITER, JT-60SA, W7-X, etc) with actively cooled plasma-facing components (PFC) and increasing duty cycle. This has motivated the development of methods to measure the deposition of material and retention of plasma fuel on the walls of fusion devices in situ, without removal of PFC samples. For this purpose, laser-based methods are the most promising candidates. Their feasibility has been assessed in a cooperative undertaking in various European associations under EFDA coordination. Different laser techniques have been explored both under laboratory and tokamak conditions with the emphasis to develop a conceptual design for a laser-based wall diagnostic which is integrated into an ITER port plug, aiming to characterize in situ relevant parts of the inner wall, the upper region of the inner divertor, part of the dome and the upper X-point region. (paper)

  6. Development of laser-based techniques for in situ characterization of the first wall in ITER and future fusion devices

    Science.gov (United States)

    Philipps, V.; Malaquias, A.; Hakola, A.; Karhunen, J.; Maddaluno, G.; Almaviva, S.; Caneve, L.; Colao, F.; Fortuna, E.; Gasior, P.; Kubkowska, M.; Czarnecka, A.; Laan, M.; Lissovski, A.; Paris, P.; van der Meiden, H. J.; Petersson, P.; Rubel, M.; Huber, A.; Zlobinski, M.; Schweer, B.; Gierse, N.; Xiao, Q.; Sergienko, G.

    2013-09-01

    Analysis and understanding of wall erosion, material transport and fuel retention are among the most important tasks for ITER and future devices, since these questions determine largely the lifetime and availability of the fusion reactor. These data are also of extreme value to improve the understanding and validate the models of the in vessel build-up of the T inventory in ITER and future D-T devices. So far, research in these areas is largely supported by post-mortem analysis of wall tiles. However, access to samples will be very much restricted in the next-generation devices (such as ITER, JT-60SA, W7-X, etc) with actively cooled plasma-facing components (PFC) and increasing duty cycle. This has motivated the development of methods to measure the deposition of material and retention of plasma fuel on the walls of fusion devices in situ, without removal of PFC samples. For this purpose, laser-based methods are the most promising candidates. Their feasibility has been assessed in a cooperative undertaking in various European associations under EFDA coordination. Different laser techniques have been explored both under laboratory and tokamak conditions with the emphasis to develop a conceptual design for a laser-based wall diagnostic which is integrated into an ITER port plug, aiming to characterize in situ relevant parts of the inner wall, the upper region of the inner divertor, part of the dome and the upper X-point region.

  7. In situ characterization of organic matter in two primitive chondrites through correlated microanalytical techniques

    Science.gov (United States)

    Wende, A. M.; Nittler, L.; Steele, A.; Herd, C. D.

    2009-12-01

    Primitive meteorites contain up to 2 wt % C, much of it in the form of insoluble organic matter (IOM). Bulk analyses have revealed the IOM to be marked by large D and 15N enrichments relative to terrestrial values. Isotopic imaging studies have revealed the presence of `hotspots’, sub-?m to ?m-sized regions of IOM exhibiting extreme isotope enrichments. An interesting subpopulation of organic grains, ’nanoglobules’, which have hollow, spherical morphologies, is known to account for a portion of these hot spots. Previous work has suggested that nanoglobules can be identified in situ by native UV fluorescence. The isotopic enrichments are believed to point to low-T chemical fractionations either in the interstellar medium (ISM) or the outer regions of the early Solar System. As part of a larger study investigating the origin and evolution of IOM in the Solar System, a correlated, in situ, microanalytical approach was employed to characterize local isotopic and morphological heterogeneities in IOM in the highly primitive chondrites QUE 99177 (CR3) and Tagish Lake (C-ung). Previous NanoSIMS ion imaging of a QUE 99177 section revealed the spatial and isotopic distribution of C in the matrix with a spatial resolution of 200 nm. Manual definition of >3300 C-rich regions in the NanoSIMS images indicates that grains smaller than 1 ?m across, which account for 80% of the IOM area, have a size distribution that is similar to estimates of the size distribution of carbonaceous dust in the diffuse ISM, supporting an interstellar origin for the IOM. Micro-Raman spectroscopy, which is highly sensitive to the degree of disorder in carbonaceous materials, was attempted on the same regions analyzed by NanoSIMS in QUE 99177. Unfortunately, surface damage due to both the prior SIMS analyses and removal of a prior C coat precluded acquisition of useful Raman spectra. Consequently, future correlated work will entail performing Raman analyses on uncoated samples prior to SIMS analysis. Previous NanoSIMS and SEM investigations of a new sample of Tagish Lake revealed the presence of isotopically anomalous nanoglobules, so several pristine fragments from it were targeted for a UV fluorescence study. Only one of five fragments analyzed so far showed fluorescence, suggesting either that nanoglobules are not present in the specific fragments or that not all nanoglobules readily fluoresce. UV measurements of additional fragments as well as correlated Raman, SEM and NanoSIMS analyses of the same samples will help resolve the question.

  8. Evaluation of three new laser spectrometer techniques for in-situ carbon monoxide measurements

    Science.gov (United States)

    Zellweger, C.; Steinbacher, M.; Buchmann, B.

    2012-07-01

    Long-term time series of the atmospheric composition are essential for environmental research and thus require compatible, multi-decadal monitoring activities. However, the current data quality objectives of the World Meteorological Organization (WMO) for carbon monoxide (CO) in the atmosphere are very challenging to meet with the measurement techniques that have been used until recently. During the past few years, new spectroscopic techniques came on the market with promising properties for trace gas analytics. The current study compares three instruments that are recently commercially available (since 2011) with the up to now best available technique (vacuum UV fluorescence) and provides a link to previous comparison studies. The instruments were investigated for their performance regarding repeatability, reproducibility, drift, temperature dependence, water vapour interference and linearity. Finally, all instruments were examined during a short measurement campaign to assess their applicability for long-term field measurements. It could be shown that the new techniques provide a considerably better performance compared to previous techniques, although some issues such as temperature influence and cross sensitivities need further attention.

  9. Evaluation of new laser spectrometer techniques for in-situ carbon monoxide measurements

    Science.gov (United States)

    Zellweger, C.; Steinbacher, M.; Buchmann, B.

    2012-10-01

    Long-term time series of the atmospheric composition are essential for environmental research and thus require compatible, multi-decadal monitoring activities. The current data quality objectives of the World Meteorological Organization (WMO) for carbon monoxide (CO) in the atmosphere are very challenging to meet with the measurement techniques that have been used until recently. During the past few years, new spectroscopic techniques came to market with promising properties for trace gas analytics. The current study compares three instruments that have recently become commercially available (since 2011) with the best currently available technique (Vacuum UV Fluorescence) and provides a link to previous comparison studies. The instruments were investigated for their performance regarding repeatability, reproducibility, drift, temperature dependence, water vapour interference and linearity. Finally, all instruments were examined during a short measurement campaign to assess their applicability for long-term field measurements. It could be shown that the new techniques perform considerably better compared to previous techniques, although some issues, such as temperature influence and cross sensitivities, need further attention.

  10. Evaluation of three new laser spectrometer techniques for in-situ carbon monoxide measurements

    Directory of Open Access Journals (Sweden)

    C. Zellweger

    2012-07-01

    Full Text Available Long-term time series of the atmospheric composition are essential for environmental research and thus require compatible, multi-decadal monitoring activities. However, the current data quality objectives of the World Meteorological Organization (WMO for carbon monoxide (CO in the atmosphere are very challenging to meet with the measurement techniques that have been used until recently. During the past few years, new spectroscopic techniques came on the market with promising properties for trace gas analytics. The current study compares three instruments that are recently commercially available (since 2011 with the up to now best available technique (vacuum UV fluorescence and provides a link to previous comparison studies. The instruments were investigated for their performance regarding repeatability, reproducibility, drift, temperature dependence, water vapour interference and linearity. Finally, all instruments were examined during a short measurement campaign to assess their applicability for long-term field measurements. It could be shown that the new techniques provide a considerably better performance compared to previous techniques, although some issues such as temperature influence and cross sensitivities need further attention.

  11. Neutron, fluorescence, and optical imaging: An in situ combination of complementary techniques

    Science.gov (United States)

    Wagner, D.; Börgardts, M.; Grünzweig, C.; Lehmann, E.; Müller, T. J. J.; Egelhaaf, S. U.; Hermes, H. E.

    2015-09-01

    An apparatus which enables the simultaneous combination of three complementary imaging techniques, optical imaging, fluorescence imaging, and neutron radiography, is presented. While each individual technique can provide information on certain aspects of the sample and their time evolution, a combination of the three techniques in one setup provides a more complete and consistent data set. The setup can be used in transmission and reflection modes and thus with optically transparent as well as opaque samples. Its capabilities are illustrated with two examples. A polymer hydrogel represents a transparent sample and the diffusion of fluorescent particles into and through this polymer matrix is followed. In reflection mode, the absorption of solvent by a nile red-functionalized mesoporous silica powder and the corresponding change in fluorescent signal are studied.

  12. Microbial composition of biofilms in a brewery investigated by fatty acid analysis, fluorescence in situ hybridisation and isolation techniques.

    Science.gov (United States)

    Timke, Markus; Wolking, Dorothee; Wang-Lieu, Ngoc Quynh; Altendorf, Karlheinz; Lipski, André

    2004-11-01

    Biofilms associated with brewery plants can harbour spoiling microorganisms that potentially damage the final product. Most beer-spoiling microorganisms are thought to depend on numerous interactions with the accompanying microbiota. However, there is no information on the microbial community structure of biofilms from bottling plants. The conveyors that transport the bottles to and from the plant are known as potential sources of microbial contamination of beer. Consequently, the material buildup from two conveyors was analysed using a cultivation/isolation approach, and the culture-independent techniques of whole cell fatty acid analysis and fluorescence in situ hybridisation (FISH). Heterogeneous communities were present at both conveyors. Although characteristic fatty acids for Eukarya were present, FISH-signals for Eukarya were extremely low. The Proteobacteria, in particular the Gammaproteobacteria, were abundant at both sample sites. Bacterial isolates were obtained for every dominating group detected by FISH: the Alphaproteobacteria, Betaproteobacteria and Gammaproteobacteria, the Xanthomonadaceae, the Actinobacteria, the Bacteroidetes and the Firmicutes. PMID:15085296

  13. Observation of localized heating phenomena during microwave heating of mixed powders using in situ x-ray diffraction technique

    Energy Technology Data Exchange (ETDEWEB)

    Sabelström, N., E-mail: sabelstrom.n.aa@m.titech.ac.jp; Hayashi, M. [Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, Tokyo 152-8552 (Japan); Watanabe, T. [Department of Chemistry and Materials Science, Tokyo Institute of Technology, Tokyo 152-8552 (Japan); Nagata, K. [Department of Conservation Science, Tokyo University of the Arts, 12-8 Ueno Park, Taito-ku, Tokyo (Japan)

    2014-10-28

    In materials processing research using microwave heating, there have been several observations of various phenomena occurring known as microwave effects. One significant example of such a phenomenon is increased reaction kinetics. It is believed that there is a possibility that this might be caused by localized heating, were some reactants would attain a higher than apparent temperature. To examine whether such thermal gradients are indeed possible, mixed powders of two microwave non-absorbers, alumina and magnesia, were mixed with graphite, a known absorber, and heated in a microwave furnace. During microwave irradiation, the local temperatures of the respective sample constituents were measured using an in situ x-ray diffraction technique. In the case of the alumina and graphite sample, a temperature difference of around 100?°C could be observed.

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

    Directory of Open Access Journals (Sweden)

    Somayeh Bakhshizadeh

    2014-04-01

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

  15. Effect of particle size on microstructure and strength of porous spinel ceramics prepared by pore-forming in situ technique

    Indian Academy of Sciences (India)

    Wen Yan; Nan Li; Yuanyuan Li; Guangping Liu; Bingqiang Han; Juliang Xu

    2011-08-01

    The porous spinel ceramics were prepared from magnesite and bauxite by the pore-forming in situ technique. The characterization of porous spinel ceramics was determined by X-ray diffractometer (XRD), scanning electron microscopy(SEM), mercury porosimetry measurement etc and the effects of particle size on microstructure and strength were investigated. It was found that particle size affects strongly on the microstructure and strength. With decreasing particle size, the pore size distribution occurs from multi-peak mode to bi-peak mode, and lastly to mono-peak mode; the porosity decreases but strength increases. The most apposite mode is the specimens from the grinded powder with a particle size of 6.53 m, which has a high apparent porosity (40%), a high compressive strength (75.6MPa), a small average pore size (2.53 m) and a homogeneous pore size distribution.

  16. Nuclear borehole logging techniques developed by CSIRO - Exploration and Mining for in situ evaluation of coal and mineral deposits

    International Nuclear Information System (INIS)

    CSIRO - Exploration and Mining Division has developed a spectrometric nuclear techniques for in situ evaluation of coal and mineral deposits. Whilst the use of this technology is seen mainly in coal mining, it is becoming increasingly apparent in metalliferous mining. The logging tools developed by CSIRO are using the gamma-gamma, prompt neutron activation and spectrometric natural gamma techniques. The technology is used both in exploration and mine production for quality control. Nuclear borehole logging is complementary to the laboratory analysis of core samples retrieved from boreholes. Although it can not provide the same detailed information as the analysis of the core, the volume of rock sampled by nuclear borehole logging is much larger than the core samples and the results are provided almost instantaneously. Nuclear logging is particularly useful for mineral deposits where the core can not be fully recovered or in situations when not all the information provided by the analysis of the core is needed. Important savings can be made if the information required is acquired by logging open holes instead of drilling more expensive cored holes. The paper reviews various techniques developed by CSIRO - Exploration and Mining for both the coal and metalliferous mining industry. Emphasis is given to current research for developing logging tools equipped with ultra - low intensity gamma-ray sources (below 3.7 MBq activity). The tools are developed for both borehole logging and face analysis

  17. Stability Study of Filtering Techniques in Pictures of mini-MIAS Database

    International Nuclear Information System (INIS)

    The study of filtering techniques applied to medical imaging is particularly important because it can be decisive for an accurate diagnosis. This work aims to study the stability of Fuzzy Peer Group Averaging filter when applied to mammographic images of different nature in relation to the type of tissue abnormality found and diagnosis. The results show that the filter is effective, because obtained a PSNR value of 27 by comparing the filtered image with the original, and a value of 17 by comparing the filtered image with contaminated with noise. Also show that the filter will behave properly regardless of the image characteristics. (Author)

  18. ECR plasma cleaning: an in-situ processing technique for RF cavities

    International Nuclear Information System (INIS)

    A condition for Electron Cyclotron Resonance (ECR) can be established inside a fully assembled RF cavity without the need for removing high-power couplers. As such, plasma generated by this process can be used as a final cleaning step, or as an alternative cleaning step in place of other techniques. Tests showed filtered dry air plasma can successfully remove sulfur particles on niobium surface while the surface oxygen content remains intact

  19. ECR plasma cleaning: an in-situ processing technique for RF cavities

    Energy Technology Data Exchange (ETDEWEB)

    Wu, G.; /Fermilab; Moeller, W-D.; /DESY; Antoine, C.; /Saclay; Jiang, H.; Pechenezhskiy, I.; Cooley, L.; Khabiboulline, T.; Terechkine, Y.; Edwards, H.; Koeth, T.; Romanenko, A.; /Cornell U., Phys. Dept. /Jefferson Lab

    2008-01-01

    A condition for Electron Cyclotron Resonance (ECR) can be established inside a fully assembled RF cavity without the need for removing high-power couplers. As such, plasma generated by this process can be used as a final cleaning step, or as an alternative cleaning step in place of other techniques. Tests showed filtered dry air plasma can successfully remove sulfur particles on niobium surface while the surface oxygen content remains intact.

  20. Spacecraft stability and control using new techniques for periodic and time-delayed systems

    Science.gov (United States)

    NAzari, Morad

    This dissertation addresses various problems in spacecraft stability and control using specialized theoretical and numerical techniques for time-periodic and time-delayed systems. First, the effects of energy dissipation are considered in the dual-spin spacecraft, where the damper masses in the platform (?) and the rotor (?) cause energy loss in the system. Floquet theory is employed to obtain stability charts for different relative spin rates of the subsystem [special characters omitted] with respect to the subsystem [special characters omitted]. Further, the stability and bifurcation of delayed feedback spin stabilization of a rigid spacecraft is investigated. The spin is stabilized about the principal axis of the intermediate moment of inertia using a simple delayed feedback control law. In particular, linear stability is analyzed via the exponential-polynomial characteristic equations and then the method of multiple scales is used to obtain the normal form of the Hopf bifurcation. Next, the dynamics of a rigid spacecraft with nonlinear delayed multi-actuator feedback control are studied, where a nonlinear feedback controller using an inverse dynamics approach is sought for the controlled system to have the desired linear delayed closed-loop dynamics (CLD). Later, three linear state feedback control strategies based on Chebyshev spectral collocation and the Lyapunov Floquet transformation (LFT) are explored for regulation control of linear periodic time delayed systems. First , a delayed feedback control law with discrete delay is implemented and the stability of the closed-loop response is investigated in the parameter space of available control gains using infinite-dimensional Floquet theory. Second, the delay differential equation (DDE) is discretized into a large set of ordinary differential equations (ODEs) using the Chebyshev spectral continuous time approximation (CSCTA) and delayed feedback with distributed delay is applied. The third strategy involves use of both CSCTA and the reduced Lyapunov Floquet transformation (RLFT) in order to design a non-delayed feedback control law. The delayed Mathieu equation is used as an illustrative example in which the closed-loop response and control effort are compared for all three control strategies. Finally, three example applications of control of time-periodic astrodynamic systems, i.e. formation flying control for an elliptic Keplerian chief orbit, body-fixed hovering control over a tumbling asteroid, and stationkeeping in Earth-Moon L1 halo orbits, are shown using versions of the control strategies introduced above. These applications employ a mixture of feedforward and non-delayed periodic-gain state feedback for tracking control of natural and non-natural motions in these systems. A major conclusion is that control effort is minimized by employing periodic-gain (rather than constant-gain) feedback control in such systems.

  1. In-situ stabilization of radioactively contaminated low-level solid wastes buried in shallow trenches: an assessment

    International Nuclear Information System (INIS)

    The potential effectiveness of materials for in-situ encapsulation of low-level, radioactively contaminated solid waste buried in shallow trenches is enumerated. Cement, clay materials, and miscellaneous sorbents, aqueous and nonaqueous gelling fluids and their combinations are available to solidify contaminated free water in trenches, to fill open voids, and to minimize radionuclide mobility. The success of the grouting technique will depend on the availability of reliable geohydrologic data and laboratory development of a mix with enhanced sorption capacity for dominant radionuclides present in the trenches. A cement-bentonite-based grout mix with low consistency for pumping, several hours controlled rate of hardening, negligible bleeding, and more than 170 kPa (25 psi) compressive strength are a few of the suggested parameters in laboratory mix development. Cost estimates of a cement-bentonite-based grout mix indicate that effective and durable encapsulation can be accomplished at a reasonable cost (about $113 per cubic meter). However, extensive implementation of the method suggests the need for a field demonstration of the method. 53 references

  2. Comparison of continuous in situ CO2 observations at Jungfraujoch using two different measurement techniques

    Science.gov (United States)

    Schibig, M. F.; Steinbacher, M.; Buchmann, B.; van der Laan-Luijkx, I. T.; van der Laan, S.; Ranjan, S.; Leuenberger, M. C.

    2015-01-01

    Since 2004, atmospheric carbon dioxide (CO2) is being measured at the High Altitude Research Station Jungfraujoch by the division of Climate and Environmental Physics at the University of Bern (KUP) using a nondispersive infrared gas analyzer (NDIR) in combination with a paramagnetic O2 analyzer. In January 2010, CO2 measurements based on cavity ring-down spectroscopy (CRDS) as part of the Swiss National Air Pollution Monitoring Network were added by the Swiss Federal Laboratories for Materials Science and Technology (Empa). To ensure a smooth transition - a prerequisite when merging two data sets, e.g., for trend determinations - the two measurement systems run in parallel for several years. Such a long-term intercomparison also allows the identification of potential offsets between the two data sets and the collection of information about the compatibility of the two systems on different time scales. A good agreement of the seasonality, short-term variations and, to a lesser extent mainly due to the short common period, trend calculations is observed. However, the comparison reveals some issues related to the stability of the calibration gases of the KUP system and their assigned CO2 mole fraction. It is possible to adapt an improved calibration strategy based on standard gas determinations, which leads to better agreement between the two data sets. By excluding periods with technical problems and bad calibration gas cylinders, the average hourly difference (CRDS - NDIR) of the two systems is -0.03 ppm ± 0.25 ppm. Although the difference of the two data sets is in line with the compatibility goal of ±0.1 ppm of the World Meteorological Organization (WMO), the standard deviation is still too high. A significant part of this uncertainty originates from the necessity to switch the KUP system frequently (every 12 min) for 6 min from ambient air to a working gas in order to correct short-term variations of the O2 measurement system. Allowing additional time for signal stabilization after switching the sample, an effective data coverage of only one-sixth for the KUP system is achieved while the Empa system has a nearly complete data coverage. Additionally, different internal volumes and flow rates may affect observed differences.

  3. Comparison of continuous in-situ CO2 observations at Jungfraujoch using two different measurement techniques

    Directory of Open Access Journals (Sweden)

    M. F. Schibig

    2014-07-01

    Full Text Available Since 2004, atmospheric carbon dioxide (CO2 is measured at the High Altitude Research Station Jungfraujoch by the division of Climate and Environmental Physics at the University of Bern (KUP using a nondispersive infrared gas analyzer (NDIR in combination with a paramagnetic O2 analyzer. In January 2010, CO2 measurements based on cavity ring down spectroscopy (CRDS as part of the Swiss National Air Pollution Monitoring Network have been added by the Swiss Federal Laboratories for Materials Science and Technology (Empa. To ensure a smooth transition – a prerequisite when merging two datasets e.g. for trend determinations – the two measurement systems run in parallel for several years. Such a long-term intercomparison also allows identifying potential offsets between the two datasets and getting information about the compatibility of the two systems on different time scales. A good agreement of the seasonality as well as for the short-term variations was observed and to a lesser extent for trend calculations mainly due to the short common period. However, the comparison revealed some issues related to the stability of the calibration gases of the KUP system and their assigned CO2 mole fraction. It was possible to adapt an improved calibration strategy based on standard gas determinations, which lead to better agreement between the two data sets. By excluding periods with technical problems and bad calibration gas cylinders, the average hourly difference (CRDS ? NDIR of the two systems is ?0.03 ppm ± 0.25 ppm. Although the difference of the two datasets is in line with the compatibility goal of ±0.1 ppm of the World Meteorological Organization (WMO, the standard deviation is still too high. A significant part of this uncertainty originates from the necessity to switch the KUP system frequently (every 12 min for 6 min from ambient air to a working gas in order to correct short-term variations of the O2 measurement system. Allowing additionally for signal stabilization after switching the sample, an effective data coverage of only 1/6 for the KUP system is achieved while the Empa system has a nearly complete data coverage. Additionally, different internal volumes and flow rates between the two systems may affect observed differences.

  4. A novel rocket-based in-situ collection technique for mesospheric and stratospheric aerosol particles

    OpenAIRE

    Reid, W.; Achtert, P.; Ivchenko, N.; P. Magnusson; T. Kuremyr; V. Shepenkov; G. Tibert

    2012-01-01

    A technique for collecting aerosol particles between altitudes of 85 and 17 km is described. Collection probes are ejected from a sounding rocket allowing for multi-point measurements. Each probe is equipped with 110 collection samples that are 3 mm in diameter. The collection samples are one of three types: standard transmission electron microscopy carbon grids, glass fibre filter paper or silicone gel. Each collection sample is exposed over a 50 m to 5 km height range with a total of 45 sep...

  5. Systematic studies of SiGe/Si islands nucleated via separate in situ or ex situ Ga+ focused ion beam-guided growth techniques

    International Nuclear Information System (INIS)

    In this study, we use 25 keV in situ and 30 keV ex situ Ga+ focused ion beams (FIBs) to locally modify the substrate before deposition and determine their effects on nucleation of molecular beam epitaxy grown Ge/Si islands. FIB processing may alter island formation in at least five ways: the surfactant effect of Ga+, doping effects of subsurface Ga+, local strains, crystalline damage, and surface roughening. To explore these possibilities, we milled square regions of increasing Ga+ doses and used atomic force microscopy to monitor islanding in and around these regions. For in situ experiments, doses ranged from ?1013 to 5x1017 ions/cm2 (0.04-400 ML). We began to observe changes in island topology at doses as low as ?1014 ions/cm2. For doses of ?1015 to ?8x1016 ions/cm2 (2-160 ML), implanted areas were surrounded by denuded zones that grew from ?0.5 to 6 ?m with increasing dose. Immediately inside the implanted area, island size and concentration appeared to peak. At doses above ?6x1016 ions/cm2 (120 ML), Ga+ produced noticeable surface depressions, which were often surrounded by enhanced island densities, rather than a denuded zone. For ex situ FIB patterning, samples underwent both pregrowth cleaning and growth of a thin capping layer (0-100 nm). Doses ranging from 7.5x1013 to ?1017 ions/cm2 (0.15-200 ML) were used in concert with varied capping layer thicknesses to study their combined affect on island nucleation. The results correspond well with in situ experiments for thin capping layers. Increased capping layer thickness resulted in muted modifications to island formation for low Ga+ doses, while for higher doses trends similar to those obtained in situ are seen

  6. Assaying depleted uranium in bones in-situ using a non-invasive x-ray fluorescence technique

    International Nuclear Information System (INIS)

    The occupational exposure to uranium associated with milling and fabrication of depleted uranium is presently assessed from bioassay of urine samples. The evaluation of the body-burden of uranium from urine analysis has many difficulties and uncertainties associated with accounting for the bio-transport of inhaled uranium particles from the lungs, to absorption in the blood and excretion through the kidneys. The chemical toxicity of uranium and other transuranic elements is not fully understood, partially because of the difficulty of assessing the body burden of these metals in-situ. The transuranic elements are known to be deposited and retained in bone. A non-invasive X-ray fluorescence technique has been developed to assay the depleted uranium in bones in-situ. The K-shell electrons in uranium, which have a binding energy of 115.6 keV, are excited by the 122 and 136 keV gamma rays from a Co-57 source. A liquid N2 cooled intrinsic Ge-detector is employed to measure the characteristic K fluorescence from the uranium as well as the coherently scattered gamma rays from the Co-57 source. The quantity of uranium in the bone is determined from the number of K fluorescence events extracted from the measured scattered photon spectrum. In addition, the bone mineral mass is determined from the number of coherently scattered gamma rays, permitting the assay of uranium to be pressed in terms of micrograms per unit mass bone. Using this system it was possible to measure molar concentrations of uranium with high precision and reproducibility

  7. A new technique to monitor the long-term stability of an optoelectronic oscillator.

    Science.gov (United States)

    Pham, Toan Thang; Ledoux-Rak, Isabelle; Journet, Bernard; Vu, Van Yem

    2015-01-01

    The main advantage of an optoelectronic oscillator (OEO) is the ability to synthesize directly very high spectral purity frequency in microwave domain. Beside applications in radar, telecommunication and satellite systems, OEO can also be used in sensor applications such as refractive index or distance measurements. However, the long-term stability of the OEO is easily affected by ambient environment variations. The optical fiber loop effective refractive index varies corresponding to its surrounding temperature changes. Consequently, it makes the optical transmission path inside the fiber loop differ from the initial state, leading to oscillation frequency changes. To stabilize the single loop OEO, it is essential to keep its high Q elements in a well-controlled thermal box as much as possible. Unfortunately, in the real implementation condition, this requirement is difficult to be satisfied. In this paper, we present a new technique to estimate the oscillation frequency variation under the room temperature by using a vector network analyzer (VNA). Experimental results show a good correlation between OEO oscillation frequency drift and the phase measured by the VNA. This technique can be implemented to apply corrections when using the OEO as a distance variation or a refractive index measurement tool. We also tracked the temperature of the fiber loop at the same time with the VNAbased experiment to compare two correlations of temperature and phase with OEO oscillation frequency.

  8. Marital stability and quality in families created by assisted reproduction techniques: a follow-up study.

    Science.gov (United States)

    Blake, L; Casey, P; Jadva, V; Golombok, S

    2012-12-01

    An increasing number of children are being born with the use of assisted reproduction techniques such as donor insemination, egg donation and surrogacy. There have been concerns that the use of these third-party reproduction techniques may have a negative effect on the quality of the relationship between the mother and father. Marital stability and quality was examined in a UK sample of donor insemination, egg donation and surrogacy families and families in which children were naturally conceived. Interview and questionnaire assessments of marital stability and quality were collected from mothers and fathers over five time points, when the children in the families were aged 1, 2, 3, 7 and 10. Of those families who participated when children were 10years old, a minority of couples in each family type had divorced/separated and few differences emerged between the different family types in terms of mothers' or fathers' marital quality. Despite concerns, couples in families created by donor insemination, egg donation and surrogacy were found to be functioning well. PMID:23063821

  9. Monitoring Nitrate, Chlorophyll, and CDOM Cycling in a Reservoir using In Situ Mapping Techniques

    Science.gov (United States)

    OConnor, J.; Showers, W. J.; Osburn, C. L.; DeMaster, D. J.

    2013-12-01

    Degradation of surface waters due to increased nutrient loading and subsequent eutrophication is a persistent problem on a global scale. Expanding human populations and their associated development create increased pressure on local watersheds in terms of both point and non-point source pollution. In this study a suite of in situ sensors measuring nitrate concentration, chlorophyll a concentration (Chl a), and chromophoric dissolved organic material (CDOM) fluorescence were deployed from a rapidly moving boat (~32 km/h) in order to identify sources of nutrients and CDOM, and to determine their relationship to eutrophication symptoms in Falls Lake, North Carolina. In addition, water samples were collected throughout the lake and from tributaries of interest for laboratory analysis. Results indicated the three main tributaries at the north end of the lake were the important contributors of both nitrate and CDOM. While two of the three were degraded due to significant effluent discharge from Waste Water Treatment Plants, the third appeared to be impacted by diffuse nutrient sources. However, atmospheric deposition of nitrate and ammonium exceeded tributary input, and the net nutrient loading to the lake was dominated by sediment release of both ammonium and phosphate. No direct relationship between nitrate and Chl a concentrations was observed, but bays that sewage impacted rivers emptied into displayed elevated Chl a values. Water samples from both the lake and streams were analyzed for stable isotopic analysis of ?15N and ?18O composition and were consistent with waste as the primary source of nitrate. Samples were also analyzed for CDOM absorbance and fluorescence through the creation of Excitation and Emission Matrices (EEMs) and the development of a nine component PARAFAC model. Fluorescence values consistently declined from the north end of the lake to the southern end at the dam and water treatment plant intake. Absorbance values at 254 nm (a254) also showed a decreasing trend from north to south, while SR increased. The loss of absorption could have been caused by photobleaching, however, a hydrologic modeling experiment demonstrated that this change in optical character was actually due to mixing of un-polluted tributary and rain water with water from the main tributaries at the north end. At the southern end of the lake, adjacent to the water treatment plant intake, a series of depth profiles were made that revealed a stratified water column during summer months. There was evidence of production of CDOM in the anoxic hypolimnion that appeared to be linked to an increase in Chl a concentration. There was also a significant increase in a254 and a decrease in SR that suggested CDOM was released from the sediments in the hypolimnion. This study showed that the north end of the lake suffered from persistent eutrophication symptoms. However, as the water traveled south to the two exit points at the dam and the water treatment plant, water quality improved.

  10. A novel rocket-based in-situ collection technique for mesospheric and stratospheric aerosol particles

    Directory of Open Access Journals (Sweden)

    W. Reid

    2012-11-01

    Full Text Available A technique for collecting aerosol particles between altitudes of 85 and 17 km is described. Collection probes are ejected from a sounding rocket allowing for multi-point measurements. Each probe is equipped with 110 collection samples that are 3 mm in diameter. The collection samples are one of three types: standard transmission electron microscopy carbon grids, glass fibre filter paper or silicone gel. Each collection sample is exposed over a 50 m to 5 km height range with a total of 45 separate ranges. Post-flight electron microscopy gives size-resolved information on particle number, shape and elemental composition. Each collection probe is equipped with a suite of sensors to capture the probe's status during the fall. Parachute recovery systems along with GPS-based localization ensure that each probe can be located and recovered for post-flight analysis.

  11. In situ studies of pesticides photodegradation on soils using PD-TOFMS technique

    Science.gov (United States)

    Thomas, J. P.; Bejjani, A.; Nsouli, B.; Gardon, A.; Chovelon, J. M.

    2009-01-01

    As we have demonstrated that plasma desorption time-of-flight mass spectrometry (PD-TOFMS) is well adapted to the direct characterization of pesticides adsorbed on agricultural soils the technique has been applied for the first time to the study of their evolution under sunlight-like irradiation. Two pesticides have been selected: norflurazon which is the most documentated (both from the literature and from our previous experiments) and oxyfluorfen in order to assess the capability of the technique. The photodegradation process has been investigated both for a deposit onto a metallic substrate and for a soil impregnated with the product. For norflurazon degradation parameters have been extracted from the yield variation of ions representative of the molecule and breakdown products and particularly the time required for 50% dissipation of their initial concentration (DT50 values). The comparison between deposits and soils indicates clearly that the degradation is slower in the latter case with an increase of about 3.5 for the DT50 of the molecule, and about 2 for its breakdown products. These values are in agreement with the decays of other ions. As expected, the degradation is faster when the UV of the sunlight is unfiltered, more significantly for the breakdown products. This is also observed for the oxyfluorfen deposited onto aluminium although at a lower level (twice less). The trends are only qualitative for the impregnated soil but definitely there. A discussion is presented for the interpretation of the photodegradation process in both cases together with suggestions of improvement in the data acquisition.

  12. Stabilized methods and post-processing techniques for Darcy flow and related problems

    International Nuclear Information System (INIS)

    In this paper we present a review of stabilized methods and post-processing techniques for Darcy flow problems, with particular emphasis in the miscible displacement model. The system of partial differential equations governing the miscible displacement consists of an elliptic system coming from the conservation of mass and Darcy's law and a nonlinear transport equation expressing the conservation of the injected fluid (concentration). The main difficulties are related to the evaluation of the primary unknowns of the elliptic equation (pressure) and their spatial derivatives by Darcy's law (velocity) and the coupling with the convection dominated transport equation. Finite element solutions for this problem have been obtained using mixed methods for the pressure/gradient problem combined with the modified method of characteristics. However, this approach involves different interpolation schemes for pressure, velocity and concentration. In order to overcome the difficulties associated with the previous schemes, we have been working in the development of finite element formulations where all variables are interpolated by equal-order functions. To recover accurate velocity approximations we have developed new global and local post-processing techniques. These post-processing techniques consist in solving the elliptic problem for pressure and then computing velocity considering residual forms of Darcy's law with the known pressure, the mass balance equation and the irrotationality condition. These post-processing techniques are then combined with semidiscrete or space-time SUPG or GLS formulations with shock capturing. We also address in this paper issues related to the improvement of computational efficiency of our methods. Among then we will show reduced integration techniques with hourglass control for the elliptic, post-processing and transport equations, its association to superconvergent techniques for gradient recovery, adaptive time stepping strategies based on feedback control theory and parallel element-by-element strategies. Extensive numerical results will show the effectiveness of our approach. (author)

  13. In situ investigation of dye adsorption on TiO2 films using a quartz crystal microbalance with a dissipation technique

    OpenAIRE

    Harms, Hauke A.; Tetreault, Nicolas; Gusak, Viktoria; Kasemo, Bengt; Graetzel, Michael

    2012-01-01

    Dye adsorption plays a crucial role in dye-sensitized solar cells. Herein, we demonstrate an in situ liquid- phase analytical technique to quantify in real time adsorption of dye and coadsorbates on flat and mesoporous TiO2 films. For the first time, a molar ratio of co-adsorbed Y123 and chenodeoxycholic acid has been measured.

  14. Combining in situ chemical oxidation, stabilization, and anaerobic bioremediation in a single application to reduce contaminant mass and leachability in soil.

    Science.gov (United States)

    Cassidy, Daniel P; Srivastava, Vipul J; Dombrowski, Frank J; Lingle, James W

    2015-10-30

    Laboratory batch reactors were maintained for 32 weeks to test the potential for an in situ remedy that combines chemical oxidation, stabilization, and anaerobic bioremediation in a single application to treat soil from a manufactured gas plant, contaminated with polycyclic aromatic hydrocarbons (PAH) and benzene, toluene, ethylbenzene, and xylenes (BTEX). Portland cement and slaked lime were used to activate the persulfate and to stabilize/encapsulate the contaminants that were not chemically oxidized. Native sulfate-reducing bacteria degraded residual contaminants using the sulfate left after persulfate activation. The ability of the combined remedy to reduce contaminant mass and leachability was compared with NaOH-activated persulfate, stabilization, and sulfate-reducing bioremediation as stand-alone technologies. The stabilization amendments increased pH and temperature sufficiently to activate the persulfate within 1 week. Activation with both stabilization amendments and NaOH removed between 55% and 70% of PAH and BTEX. However, combined persulfate and stabilization significantly reduced the leachability of residual BTEX and PAH compared with NaOH activation. Sulfide, 2-naphthoic acid, and the abundance of subunit A of the dissimilatory sulfite reductase gene (dsrA) were used to monitor native sulfate-reducing bacteria, which were negatively impacted by activated persulfate, but recovered completely within weeks. PMID:26093352

  15. Development of vacuum transfer techniques for tokamak in-situ surface analysis

    International Nuclear Information System (INIS)

    Plasma-wall interactions in tokamaks can in general be divided into atomic scale and grain size effects. The former class of effects include desorption, sputtering, recoil doping, and other related subjects, while the latter includes larger scale phenomena such as blistering, flaking, cracking and evaporation. These latter effects can be analysed using conventional metallurgical techniques. However, atomic scale processes require that the samples be maintained and analysed in a vacuum environment since monolayer changes can occur in minutes at 10-6 Pa (approximately=10-8 Torr). For this reason it is essential that surface analysis either be done in the tokamak during or briefly after a discharge or the surface of interest should be quickly transferred under vacuum to an ultra high vacuum (UHV) instrument for immediate analysis. However, under certain conditions it is desirable to transfer exposed samples or specially prepared substrates under vacuum for analysis in other UHV instruments not on-line. This requires the use of an ultra high vacuum transfer device (VTD). (Auth.)

  16. Wheat improvement for drought resistance and yield stability using mutation techniques

    International Nuclear Information System (INIS)

    The main problem of plant breeding is development of varieties with optimal combination of high drought resistance, productivity and yield stability in varying unfavorable conditions. It is especially important for Kazakhstan, the main agricultural areas of which are located in the arid zones characterized by moisture supply deficiency. Mutation techniques have proven to be valuable technique in enhancing crop genetic diversity for selecting new variants with traits of economic importance. Therefore we used M2 population of spring bread wheat var. Kazakhstastanskaya 126 treated by nicotinic acid extracted from tobacco leaves 0,01% and 0,1%, respectively. Based on germplasm of M2 there was developed genotype Grekum 476 having changes in leaf shape such as rolling of flag leaf. This trait protects plant from intensive insolation and overheating, prevent losses of water and provide long-term function of leaves and therefore it was used for wheat improvement of commercial cultivars. The objective of this study is the analysis of genotype x environment interaction (GEI) and evaluation of the donors of drought resistance and stability among the winter wheat genotypes. Experimental material has been grown in 2004-2006 at thee contrasting ecological zones including irrigated and non-irrigated conditions. To analyze GEI the method Tai (1971) was used. Drought susceptibility index was used for drought resistance assessment (Fisher and Maurer, 1978). The objects of study were wheat genotypes with inserted leaf rolling trait (Grekum 476, Hostianum 88, Albidum 109, Miras), and varieties developed in Kazakhstan and the Ukraine, that differ in the level of productivity and drought resistance. It was found that rolling leaf trait in the main source Grekum 476 is controlled by two dominant Rl-genes. The genotypes with Rl-genes able to conserve high leaf water potential as the tendency for greater leaf hydration seems to be a consequence of osmotic adjustment connected to drought resistance has a high level of osmotic adjustment. Analysis of GEI allowed differentiating experimental material by the level of stability. The best stability observed in donors of RL-genes - Grekum 476 and Album 109. The biggest level of field drought resistance was observed in varieties Bogarnaya 56, Krasnovodopadskaya 210 and Grekum 476, which were high yielding in stress environments. It is known that ecological reaction of adaptability - the rolling of leaves, is the characteristics for the varieties with Rl-genes. This trait allows using water economically by limitation of transpiration, to regulate plant water balance more efficiently. Obviously, the high level of drought resistance of Grekum 476 has been provided by the presence in its genotype of Rl-genes. Thus, the use of chemical mutagen allowed widening the spectrum of genetic variability of wheat germplasm. In comparison to the origin cultivar Kazakhstanskaya 126, their mutant derivatives demonstrated higher level of drought resistance and yield stability. These germplasms were ranged by the level of yield stability and drought resistance in wheat. The relationship between field drought resistance and ecological parameters of stability was found. (author)

  17. Visualisation of EDZ fractures by using the in-situ resin impregnation technique: what have we learned?

    International Nuclear Information System (INIS)

    Document available in extended abstract form only. For the visualisation and characterisation of the Excavation Damaged Zone (EDZ) in argillaceous rocks, a technique was developed 14 years ago for getting undisturbed rock samples by a special sampling process. This technique consists of injecting fluorescence-doped epoxy resin into a borehole, which flows into the fractures. The injection borehole is packed off by a mechanical packer. After polymerisation of the resin, the injection borehole is over-cored or surrounded by large diameter sampling boreholes, and the impregnated fractures on the Drill-cores are analysed under UV light. Together with neighbouring boreholes, the EDZ fracture network behind the tunnel wall can then be derived by interpolation of fractures between the individual boreholes. This in situ resin impregnation technique has been applied successfully for many studies conducted at Mont Terri (FM-B, FP, EZ-G experiments) and at Bure (SUG, FOR experiments) rock laboratories. In the frame of the EZ-A experiment performed at Mont Terri, a similar imaging method has been applied for identifying the water-conducting features inside the EDZ fracture network, which were saturated after the performance of cross-hole hydraulic tests using water as the injection fluid. The water was first spiked by a fluorescein tracer in order to identify the water conducting features in Drill-cores that correspond to EDZ fractures, mainly reactivated tectonic faults. Thanks to this method, self-sealing features of reactivated faults could be evidenced. Data collected by these methods enabled to better constrain the geometry and kinematics of the EDZ fracture network (fracture orientations, frequencies and extent), to provide data on the fracture opening and to identify the potential flow paths along the EDZ. Thin sections analysed under UV light give valuable information on the degree of connectivity of the impregnated fracture network. Micro-fractures with openings down to the order of 1/100 mm could be impregnated with this technique. At Bure and Mont Terri, the first metre behind the tunnel wall is characterised by a well-interconnected EDZ fracture network. These impregnated fractures correspond exclusively to EDZ fractures at Bure but largely to reactivated pre-existing tectonic faults and bedding planes at Mont Terri, where these natural heterogeneities strongly interfere with the creation of EDZ fractures. Numerous field observations indicate that tectonic faults control the initiation and localisation of EDZ fractures. In conclusion, the in situ impregnation of the fracture network enables to better define the structure of the EDZ fracture network. When combined with pneumatic and hydrogeological tests for deriving hydraulic parameters such as permeability and transmissivity of the fracture network, this technique contributes to refine significantly the conceptual models of the EDZ. This methodology is not site-specific and is thus applicable to any argillaceous underground facility. (authors)

  18. Influence of in situ synthesized TiC on thermal stability and corrosion behavior of Zr60Cu10Al15Ni15 amorphous composites

    International Nuclear Information System (INIS)

    In situ synthesized TiC particles were prepared by a thermal explosion method. Adding “in situ synthesized” TiC into Zr60Cu10Al15Ni15 glass matrix to obtain amorphous matrix composites was achieved. The corrosion behavior of Zr60Cu10Al15Ni15 amorphous composites was evaluated using potentiodynamic polarization measurements in 3.5 wt% NaCl solution at room temperature. The results show that the microhardness and thermal stability are improved apparently, while the TiC (?0.6 wt%) does not significantly affect the supercooled liquid behavior. Moreover, the corrosion resistance is improved apparently because the nanocrystals accelerate the diffusion of passive elements for faster formation of the protective passive film at nanocrystals/amorphous interfaces. However, when the TiC content is more than 0.6 wt%, both glass forming ability and corrosion resistance are reduced significantly

  19. Trace Metals in Groundwater and Vadose Zone Calcite: In Situ Containment and Stabilization of Stronthium-90 and Other Divalent Metals and Radionuclides at Arid West DOE

    International Nuclear Information System (INIS)

    Radionuclide and metal contaminants such as strontium-90 are present beneath U.S. Department of Energy (DOE) lands in both the groundwater (e.g., 100-N area at Hanford, WA) and vadose zone (e.g., Idaho Nuclear Technology and Engineering Center [INTEC] at the Idaho National Laboratory [INL]). In situ containment and stabilization of these contaminants is a cost-effective treatment strategy. However, implementing in situ containment and stabilization approaches requires definition of the mechanisms that control contaminant sequestration. We are investigating the in situ immobilization of radionuclides or contaminant metals (e.g., strontium-90) by their facilitated co-precipitation with calcium carbonate (primarily calcite) in groundwater and vadose zone systems. Our facilitated approach relies upon the hydrolysis of introduced urea to cause the acceleration of calcium carbonate precipitation (and trace metal co-precipitation) by (a) increasing pH and alkalinity and (b) liberating cations from the aquifer matrix by cation exchange reactions. Subsurface urea hydrolysis is catalyzed by the urease enzyme, which is produced in situ by native urea hydrolyzing microorganisms. Because the precipitation process tends to be irreversible and many western aquifers are saturated with respect to calcite, the co-precipitated metals and radionuclides will be effectively removed from the aqueous phase over the long term. We are currently conducting field based activities at both the INL Vadose Zone Research Park (VZRP), an uncontaminated surrogate site for the strontium-90 contaminated vadose zone at INTEC and at the strontium-90 contaminated aquifer of 100-N area of the Hanford site

  20. Trace Metals in Groundwater and the Vadose Zone Calcite: In Situ Containment and Stabilization of Strontium-90 and Other Divalent Metals and Radionuclides at Arid West DOE

    International Nuclear Information System (INIS)

    Radionuclide and metal contaminants such as strontium-90 are present beneath U.S. Department of Energy (DOE) lands in both the groundwater (e.g., 100-N area at Hanford, WA) and vadose zone (e.g., Idaho Nuclear Technology and Engineering Center at the Idaho National Engineering and Environmental Laboratory). In situ containment and stabilization of these contaminants is a cost-effective treatment strategy. However, implementing in situ containment and stabilization approaches requires definition of the mechanisms that control contaminant sequestration. We are investigating the in situ immobilization of radionuclides or contaminant metals (e.g., strontium-90) by their facilitated co-precipitation with calcium carbonate in groundwater and vadose zone systems. Our facilitated approach, shown schematically in Figure 1, relies upon the hydrolysis of introduced urea to cause the acceleration of calcium carbonate precipitation (and trace metal co-precipitation) by increasing pH and alkalinity. Subsurface urea hydrolysis is catalyzed by the urease enzyme, which may be either introduced with the urea or produced in situ by ubiquitous subsurface urea hydrolyzing microorganisms. Because the precipitation process tends to be irreversible and many western aquifers are saturated with respect to calcite, the co-precipitated metals and radionuclides will be effectively removed from the aqueous phase over the long-term. Another advantage of the ureolysis approach is that the ammonium ions produced by the reaction can exchange with radionuclides sorbed to subsurface minerals, thereby enhancing the availability of the radionuclides for re-capture in a more stable solid phase (co-precipitation rather than adsorption)

  1. Tuning of colossal dielectric constant in gold-polypyrrole composite nanotubes using in-situ x-ray diffraction techniques

    Energy Technology Data Exchange (ETDEWEB)

    Sarma, Abhisakh; Sanyal, Milan K., E-mail: milank.sanyal@saha.ac.in [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India)

    2014-09-15

    In-situ x-ray diffraction technique has been used to study the growth process of gold incorporated polypyrrole nanotubes that exhibit colossal dielectric constant due to existence of quasi-one-dimensional charge density wave state. These composite nanotubes were formed within nanopores of a polycarbonate membrane by flowing pyrrole monomer from one side and mixture of ferric chloride and chloroauric acid from other side in a sample cell that allows collection of x-ray data during the reaction. The size of the gold nanoparticle embedded in the walls of the nanotubes was found to be dependent on chloroauric acid concentration for nanowires having diameter more than 100 nm. For lower diameter nanotubes the nanoparticle size become independent of chloroauric acid concentration and depends on the diameter of nanotubes only. The result of this study also shows that for 50 nm gold-polypyrrole composite nanotubes obtained with 5.3 mM chloroauric acid gives colossal dielectric constant of about 10{sup 7}. This value remain almost constant over a frequency range from 1Hz to 10{sup 6} Hz even at 80 K temperature.

  2. Tuning of colossal dielectric constant in gold-polypyrrole composite nanotubes using in-situ x-ray diffraction techniques

    Directory of Open Access Journals (Sweden)

    Abhisakh Sarma

    2014-09-01

    Full Text Available In-situ x-ray diffraction technique has been used to study the growth process of gold incorporated polypyrrole nanotubes that exhibit colossal dielectric constant due to existence of quasi-one-dimensional charge density wave state. These composite nanotubes were formed within nanopores of a polycarbonate membrane by flowing pyrrole monomer from one side and mixture of ferric chloride and chloroauric acid from other side in a sample cell that allows collection of x-ray data during the reaction. The size of the gold nanoparticle embedded in the walls of the nanotubes was found to be dependent on chloroauric acid concentration for nanowires having diameter more than 100 nm. For lower diameter nanotubes the nanoparticle size become independent of chloroauric acid concentration and depends on the diameter of nanotubes only. The result of this study also shows that for 50 nm gold-polypyrrole composite nanotubes obtained with 5.3 mM chloroauric acid gives colossal dielectric constant of about 107. This value remain almost constant over a frequency range from 1Hz to 106 Hz even at 80 K temperature.

  3. Tuning of colossal dielectric constant in gold-polypyrrole composite nanotubes using in-situ x-ray diffraction techniques

    International Nuclear Information System (INIS)

    In-situ x-ray diffraction technique has been used to study the growth process of gold incorporated polypyrrole nanotubes that exhibit colossal dielectric constant due to existence of quasi-one-dimensional charge density wave state. These composite nanotubes were formed within nanopores of a polycarbonate membrane by flowing pyrrole monomer from one side and mixture of ferric chloride and chloroauric acid from other side in a sample cell that allows collection of x-ray data during the reaction. The size of the gold nanoparticle embedded in the walls of the nanotubes was found to be dependent on chloroauric acid concentration for nanowires having diameter more than 100 nm. For lower diameter nanotubes the nanoparticle size become independent of chloroauric acid concentration and depends on the diameter of nanotubes only. The result of this study also shows that for 50 nm gold-polypyrrole composite nanotubes obtained with 5.3 mM chloroauric acid gives colossal dielectric constant of about 107. This value remain almost constant over a frequency range from 1Hz to 106 Hz even at 80 K temperature

  4. A study on the machinability behaviour of Al-TiC composite prepared by in situ technique

    International Nuclear Information System (INIS)

    With the wide range of applications of metal-matrix composites (MMCs), the machining of these materials has become a very important subject for research. This paper discusses the experimental investigation on chip formation and cutting force measurement during shaping operation of Al-TiC MMCs produced by the in situ technique and compared with those for Al-TiAl3 composite and Al-Si alloys. The machinability of MMCs was characterised by the nature of chip formed, cutting force and machined surface produced. It was observed that there was improvement in the quality of the machined surface with increased amount of TiC particles in the composite. The cutting force for Al-TiAl3 composite and Al-Si was higher than that for Al-TiC composite. The machinability studies were supplemented by scanning electron microscope (SEM) and X-ray diffractometer (XRD) studies. The cutting forces were measured during the shaping operation with the help of a dynamometer using HSS cutting tool, dry environment and keeping cutting velocity, feed and depth of cut constant. The chips formed were also characterised and compared from the point of view of machinability

  5. Technical Note: A novel rocket-based in situ collection technique for mesospheric and stratospheric aerosol particles

    Directory of Open Access Journals (Sweden)

    W. Reid

    2013-03-01

    Full Text Available A technique for collecting aerosol particles between altitudes of 17 and 85 km is described. Spin-stabilized collection probes are ejected from a sounding rocket allowing for multi-point measurements. Each probe is equipped with 110 collection samples that are 3 mm in diameter. The collection samples are one of three types: standard transmission electron microscopy carbon grids, glass fibre filter paper or silicone gel. Collection samples are exposed over a 50 m to 5 km height range with a total of 45 separate ranges. Post-flight electron microscopy will give size-resolved information on particle number, shape and elemental composition. Each collection probe is equipped with a suite of sensors to capture the probe's status during the fall. Parachute recovery systems along with GPS-based localization will ensure that each probe can be located and recovered for post-flight analysis.

  6. Demonstration of the stabilization technique for nonplanar optical resonant cavities utilizing polarization

    Energy Technology Data Exchange (ETDEWEB)

    Akagi, T.; Araki, S.; Funahashi, Y.; Honda, Y.; Okugi, T.; Omori, T.; Shimizu, H.; Terunuma, N.; Urakawa, J. [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Miyoshi, S.; Takahashi, T., E-mail: tohru-takahashi@hiroshima-u.ac.jp; Tanaka, R.; Uesugi, Y.; Yoshitama, H. [AdSM Hiroshima University, 1-3-1 Kagamiyama, Higashi, Hiroshima 739-8530 (Japan); Sakaue, K.; Washio, M. [Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku 169-8555 (Japan)

    2015-04-15

    Based on our previously developed scheme to stabilize nonplanar optical resonant cavities utilizing polarization caused by a geometric phase in electromagnetic waves traveling along a twisted path, we report an application of the technique for a cavity installed in the Accelerator Test Facility, a 1.3-GeV electron beam accelerator at KEK, in which photons are generated by laser-Compton scattering. We successfully achieved a power enhancement of 1200 with 1.4% fluctuation, which means that the optical path length of the cavity has been controlled with a precision of 14 pm under an accelerator environment. In addition, polarization switching utilizing a geometric phase of the nonplanar cavity was demonstrated.

  7. Experimental analysis of mechanical response of stabilized occipitocervical junction by 3D mark tracking technique

    Science.gov (United States)

    Germaneau, A.; Doumalin, P.; Dupré, J. C.; Brèque, C.; Brémand, F.; D'Houtaud, S.; Rigoard, P.

    2010-06-01

    This study is about a biomechanical comparison of some stabilization solutions for the occipitocervical junction. Four kinds of occipito-cervical fixations are analysed in this work: lateral plates fixed by two kinds of screws, lateral plates fixed by hooks and median plate. To study mechanical rigidity of each one, tests have been performed on human skulls by applying loadings and by studying mechanical response of fixations and bone. For this experimental analysis, a specific setup has been developed to impose a load corresponding to the flexion-extension physiological movements. 3D mark tracking technique is employed to measure 3D displacement fields on the bone and on the fixations. Observations of displacement evolution on the bone according to the fixation show different rigidities given by each solution.

  8. Demonstration of the stabilization technique for nonplanar optical resonant cavities utilizing polarization

    International Nuclear Information System (INIS)

    Based on our previously developed scheme to stabilize nonplanar optical resonant cavities utilizing polarization caused by a geometric phase in electromagnetic waves traveling along a twisted path, we report an application of the technique for a cavity installed in the Accelerator Test Facility, a 1.3-GeV electron beam accelerator at KEK, in which photons are generated by laser-Compton scattering. We successfully achieved a power enhancement of 1200 with 1.4% fluctuation, which means that the optical path length of the cavity has been controlled with a precision of 14 pm under an accelerator environment. In addition, polarization switching utilizing a geometric phase of the nonplanar cavity was demonstrated

  9. Photo stability of Uranine via Crossed-Beam Thermal Lens Technique

    International Nuclear Information System (INIS)

    Uranine is a diagnostic aid in ophthalmology and is used as an immuno histological stain. A photo stability study on this important compound using a crossed-beam thermal lens (TL) technique was carried out. The study is based on the photodegradation (PD) behavior and rate regarding some experimental parameters such as the incident laser power, wavelength, modulation frequency, and sample concentration. The effects of such parameters on the TL signal and PD rate are discussed in details. It has been found that the PD rate is proportional to the power of the pumping laser and the concentration of the sample within the investigated range. However, the modulation frequency is found not to influence the PD rate. The photochemical quantum yield has been measured using potassium ferrioxalate actinometry and it was found to be very low.

  10. Synthesis, microstructure and mechanical properties of ceria stabilized tetragonal zirconia prepared by spray drying technique

    Indian Academy of Sciences (India)

    S C Sharma; N M Gokhale; Rajiv Dayal; Ramji Lal

    2002-02-01

    Ceria stabilized zirconia powders with ceria concentration varying from 6 to 16 mol% were synthesized using spray drying technique. Powders were characterized for their particle size distribution and specific surface area. The dense sintered ceramics fabricated using these powders were characterized for their microstructure, crystallite size and phase composition. The flexural strength, fracture toughness and microhardness of sintered ceramics were measured. High fracture toughness and flexural strength were obtained for sintered bodies with 12 mol% of CeO2. Flexural strength and fracture toughness were dependent on CeO2 concentration, crystallite size and phase composition of sintered bodies. Correlation of data has indicated that the transformable tetragonal phase is the key factor in controlling the fracture toughness and strength of ceramics. It has been demonstrated that the synthesis method is effective to prepare nanocrystalline tetragonal ceria stabilized zirconia powders with improved mechanical properties. Ce–ZrO2 with 20 wt% alumina was also prepared with flexural strength, 1200 MPa and fracture toughness, 9.2 MPa $\\surd$m.

  11. Stabilization of cadmium-impacted soils using jet-grouting techniques

    Energy Technology Data Exchange (ETDEWEB)

    Day, S.R. [Geo-Con, Inc., Denver, CO (United States); Zarlinski, S.J. [Kiber Environmental Services, Inc., Atlanta, GA (United States); Jacobson, P. [Woodward-Clyde, Blue Bell, PA (United States)

    1997-12-31

    Stabilization treatment applied using jet-grouting techniques was identified as a preferred remedy for soils contaminated with elevated concentrations of cadmium at an industrial site located in the State of New York. Past releases of hazardous substances, primarily cadmium, at the facility have been documented. Field investigations performed by the facility owner identified potential receptors of the cadmium-containing soils and surface run-off, and determined the extent of the cadmium contamination. These investigations revealed that a total of 4100 m{sup 3} of subsurface soil have been impacted by cadmium. Prior to construction, a treatability study was performed to define and verify effective reagent and grout formulations. Total cadmium concentrations in the soil were approximately 130 milligrams per kilogram (mg/kg) with Toxicity Characteristics Leaching Procedure (TCLP) leachable cadmium concentrations of 2.2 milligrams per liter (mg/L). The concentrations exceeded the TCLP regulatory limit of 1.0 mg/L. The soil was relatively dense sand and gravel. Reagents evaluated for stabilization of the cadmium-impacted soils included Portland cement, blast furnace slag, fly ash, ferrous sulfate and potassium permanganate.

  12. On the Decay Ratio Determination in BWR Stability Analysis by Auto-Correlation Function Techniques

    International Nuclear Information System (INIS)

    A novel auto-correlation function (ACF) method has been investigated for determining the oscillation frequency and the decay ratio in BWR stability analyses. The neutron signals are band-pass filtered to separate the oscillation peak in the power spectral density (PSD) from background. Two linear second-order oscillation models are considered. These models, corrected for signal filtering and including a background term under the peak in the PSD, are then least-squares fitted to the ACF of the previously filtered neutron signal, in order to determine the oscillation frequency and the decay ratio. Our method uses fast Fourier transform techniques with signal segmentation for filtering and ACF estimation. Gliding 'short-term' ACF estimates on a record allow the evaluation of uncertainties. Numerical results are given which have been obtained from neutron data of the recent Forsmark I and Forsmark II NEA benchmark project. Our results are compared with those obtained by other participants in the benchmark project. The present PSI report is an extended version of the publication K. Behringer, D. Hennig 'A novel auto-correlation function method for the determination of the decay ratio in BWR stability studies' (Behringer, Hennig, 2002)

  13. Applying the digital-image-correlation technique to measure the deformation of an old building’s column retrofitted with steel plate in an in situ pushover test

    Indian Academy of Sciences (India)

    Shih-Heng Tung; Ming-Hsiang Shih; Wen-Pei Sung

    2014-06-01

    An in situ pushover test is carried out on an old building of Guan-Miao elementary school in south Taiwan. Columns of this building are seismically retrofitted with steel plate. The DIC (digital-image-correlation) technique is used to measure the deformation of the retrofitted column. The result shows that the DIC technique can be successfully applied to measure the relative displacement of the column. Additionally, thismethod leads to the measurement of relative displacements formany points on the column simultaneously. Hence, the column deformation curve, rotation and curvature can be determined using interpolation method. The resulting curvaturediagram reveals that the phenomenon of plastic hinge occurs at about 2% storey drift ratio, and that the DIC technique can be applied to measure column deformation in a full scale in situ test.

  14. In–situ Spatiotemporal Chemical Reactions at Water-Solid Interfacial Processes using Microelectrode Techniques: from Biofilm to Metal Corrosion

    Science.gov (United States)

    Recent developments in microscale sensors allows the non-destructive and in–situ measurement of both the absolute and changes in chemical concentrations in engineered and natural aquatic systems. Microelectrodes represent a unique tool for studying in–situ chemical reactions in b...

  15. Robust Power System Stabilizer Design Using Genetic Local Search Technique for Single Machine Connected to an Infinite Bus

    OpenAIRE

    Mohamed Zellagui

    2008-01-01

    The genetic local search technique hybridizes the genetic algorithm and the local search (such as hill climbing) in order to eliminate the disadvantages in genetic algorithm. The parameters of the power system stabilizer (gain, phase lead time constant) are tuned by considering the single machine connected to infinite bus system. Here, power system stabilizer are used for damping low frequency local mode of oscillations. Eigen value analysis shows that the proposed GLSPSS based PSS have bette...

  16. THE EFFICACY OF REINFORCEMENT TECHNIQUE ON THE FLY ASH STABILIZED EXPANSIVE SOIL AS A SUBGRADE EMBANKMENT FOR HIGHWAYS

    OpenAIRE

    KOTESWARA RAO.D

    2011-01-01

    The most significant factor that influencing the design thickness of a flexible pavement overlay is rebound deformation from repeated load application and subgrade support values . It is essential to stabilize and reinforce the poor soils to bear the traffic intensity or truck loading. Different types of materials are provided with stabilization techniques to achieve suitable performance and to reduce maintenance costs and also to provide required service life for the subgrade embankments. In...

  17. Elaboration of Nanocomposites Based on Poly (Ethyl Methacrylate-co-Acrylonitrile by In Situ Polymerization Using an Algerian Bentonite. Thermal Stability and Kinetic Study

    Directory of Open Access Journals (Sweden)

    Djadoun S.

    2012-08-01

    Full Text Available This contribution focuses on the synthesis and characterization of nanocomposites based on poly (ethyl methacrylate-co-acrylonitrile (PEMAN and different loadings of an organically modified bentonite from Algeria prepared via in situ polymerization. TEM images and X-ray patterns revealed that depending on the loading of this clay, intercalated or partially exfoliated nanocomposites were obtained. These nanocomposites showed an increase in their glass transition temperature compared to the pure copolymer as investigated by Differential Scanning Calorimetry and improved thermal stability as evidenced by Thermogravimetric analysis and kinetics of their thermal degradation. Activation energies (Ea of thermal decomposition of PEMAN and its nanocomposites were determined by Flynn–Wall–Ozawa and Kissinger-Akahira-Sunose methods. The changes in (Ea value with the level of conversion suggest a significant improved thermal stability of the nanocomposites compared to the copolymer matrix.

  18. Emulsification technique affects oxidative stability of fish oil-in-water emulsions

    DEFF Research Database (Denmark)

    Horn, Anna Frisenfeldt; Nielsen, Nina Skall

    In oil-in-water emulsions, lipid oxidation is expected to be initiated at the oil-water interface. The properties of the emulsifier used, and the structure at the interface is therefore expected to be of great importance for lipid oxidation in emulsions. Previous studies have shown that e.g. homogenization pressure can affect how proteins locate themselves at the interface of an emulsion. The hypothesis is therefore that emulsions produced with different emulsification equipments differ in their oxidative stability due to differences in the behaviour of the proteins at the interface. The aim of this study was to compare lipid oxidation in 10% fish oil-in-water emulsions prepared by two different kinds of high pressure homogenizers i.e. a microfluidizer and a two valve high pressure homogenizer. Emulsions were made with equal droplet sizes, and with either 1% sodium caseinate or 1% whey protein isolate. Emulsions were characterised and investigated by microscopy. Lipid oxidation was assessed by PV and the formation of secondary volatile oxidation products. Results showed that the different emulsification techniques had an influence on lipid oxidation and that the effect of the emulsification technique depended on the type of protein used as an emulsifier.

  19. Emulsification technique affects oxidative stability of fish oil-in-water emulsion

    DEFF Research Database (Denmark)

    Horn, Anna Frisenfeldt; Nielsen, Nina Skall

    In oil-in-water emulsions, lipid oxidation is expected to be initiated at the oil-water interface. The properties of the emulsifier used, and the structure at the interface is therefore expected to be of great importance for lipid oxidation in emulsions. Previous studies have shown that e.g. homogenization pressure can affect how proteins locate themselves at the interface of an emulsion. The hypothesis is therefore that emulsions produced with different emulsification equipments differ in their oxidative stability due to differences in the behaviour of the proteins at the interface. The aim of this study was therefore to compare lipid oxidation in 10% fish oil-in-water emulsions prepared by two different kinds of high pressure homogenizers i.e. a microfluidizer and a two valve high pressure homogenizer. Emulsions were made with equal droplet sizes, and with either 1% sodium caseinate or 1% whey protein isolate. Emulsions were characterised and investigated by microscopy. Lipid oxidation was assessed by PV and the formation of secondary volatile oxidation products. Results showed that the different emulsification techniques had an influence on lipid oxidation and that the effect of the emulsification technique depended on the type of protein used as an emulsifier.

  20. STABILITY OF PATTERNS OF BEHAVIOR IN THE BUTTERFLY TECHNIQUE OF THE ELITE SWIMMERS

    Directory of Open Access Journals (Sweden)

    Hugo Louro

    2010-09-01

    Full Text Available The purpose of this study was to find patterns in the butterfly swimming technique, with an adaptation of the Behavioral Observation System Tech. This, as an instrument for ad-hoc qualitative analysis, enables the study of the stability of the technical implementation. When used in the training of swimmers, analysis can reduce the variability of behavioral tuning swimming technique. Through the analysis of temporal patterns (T-pattern and a sequence of five cycles running at hand maximum speed, the behavior of four technical Portuguese elite swimmers, with a record of 259 alphanumeric codes and a total of 160 configurations, were studied. The structure of the original instrument, based on a mixed system of categories and formats Field, can record technical features, observed during the execution of hand cycles. The validity was ensured through the index of intra-observer reliability (95% and inter-observer accuracy (96%. To detect patterns in each swimmer, the Theme 5.0 software was used, which allowed to identify the stable structures of technical performance within a critical interval of time (p <0.05 - t-patterns. The patterns were different, adjusting to the characteristics of technical implementation of the swimmers. It was found that the swimmer can create settings with different levels of structure complexity, depending on the implementation of changes within the hand cycle. Variations of codes in each configuration obtained using the SOCTM, allowed determining the differences between swimmers. However, the records showed a clear behavioral similarity when comparing the result with a general pattern of the butterfly technique. The potential quality of this instrument seems to be important due to the patterns obtained from a temporal sequence

  1. A low-cost optode-array measuring system based on 1 mm plastic optical fibers - new technique for in situ detection and quantification of pyrite weathering processes

    Energy Technology Data Exchange (ETDEWEB)

    Hecht, H.; Kolling, A. [University of Bremen, Bremen (Germany). Dept. of Geoscience

    2001-07-01

    Optical oxygen sensors and a sensor array were developed on the basis of 1 mm. plastic optical fibers (POF). They can be adapted to a commercially available single-channel optical fluorescence lifetime measuring device. The sensors are inexpensive and show high mechanical stability. The developed sensor array for 1 mm POF shows good reproducibility. The measuring system allows long-term in situ measurement of oxygen concentrations. In a field test, the measuring system could be used successfully for the in situ measurement in the oxygen-consuming environment of a brown coal dump body. In laboratory experiments, the system was used for the observation and quantification of pyrite oxidation processes in column experiments.

  2. Fabrication of zirconia composite membrane by in-situ hydrothermal technique and its application in separation of methyl orange.

    Science.gov (United States)

    Kumar, R Vinoth; Ghoshal, Aloke Kumar; Pugazhenthi, G

    2015-11-01

    The main objective of the work was preparation of zirconia membrane on a low cost ceramic support through an in-situ hydrothermal crystallization technique for the separation of methyl orange dye. To formulate the zirconia film on the ceramic support, hydrothermal reaction mixture was prepared using zirconium oxychloride as a zirconia source and ammonia as a precursor. The synthesized zirconia powder was characterized by X-ray diffractometer (XRD), N2 adsorption/desorption isotherms, Thermogravimetric analysis (TGA), Fourier transform infrared analysis (FTIR), Energy-dispersive X-ray (EDX) analysis and particle size distribution (PSD) to identify the phases and crystallinity, specific surface area, pore volume and pore size distribution, thermal behavior, chemical composition and size of the particles. The porosity, morphological structure and pure water permeability of the prepared zirconia membrane, as well as ceramic support were investigated using the Archimedes' method, Field emission scanning electron microscopy (FESEM) and permeability. The specific surface area, pore volume, pore size distribution of the zirconia powder was found to be 126.58m(2)/g, 3.54nm and 0.3-10µm, respectively. The porosity, average pore size and pure water permeability of the zirconia membrane was estimated to be 42%, 0.66µm and 1.44×10(-6)m(3)/m(2)skPa, respectively. Lastly, the potential of the membrane was investigated with separation of methyl orange by means of flux and rejection as a function of operating pressure and feed concentration. The rejection was found to decrease with increasing the operating pressure and increases with increasing feed concentrations. Moreover, it showed a high ability to reject methyl orange from aqueous solution with a rejection of 61% and a high permeation flux of 2.28×10(-5)m(3)/m(2)s at operating pressure of 68kPa. PMID:25982409

  3. Carotenoids digestion in african stargrass (Cynodon plectostachyus) determined with In Situ techniques in cattle / Digestión de carotenoides en pasto estrella (Cynodon plectostachyus) determinado con técnicas In Situ en bovinos

    Scientific Electronic Library Online (English)

    R.G., Cruz-Monterrosa; J.E., Ramírez-Bribiesca; M.I., Guerrero-Legarreta; O., Hernández-Mendo.

    2011-12-01

    Full Text Available La material seca (MS) y la desaparición total de carotenoides del pasto estrella (PE) en el rumen e intestino del pasto estrella (PE) fueron medidas en 4 becerros Holstein, utilizando las técnicas In situ en rumen y la de bolsas de nylon móviles en duodeno, respectivamente. Una alta proporción de MS [...] y carotenoides totales (P Abstract in english Dry matter (DM) and total carotenoids disappearane in the rumen and intestinal passage of African stargrass (AS) were measured in 4 Holstein steers using rumen In situ and a mobile nylon bag technique in duodenum, respectively. A higher proportion of DM and total carotenoids (P[...] peared in the rumen during first 12 h. Correlation value between the disappearance of DM and total carotenoids in the rumen was 0.997 (P

  4. Demonstration of pseudorabies virus DNA in the mouse inner ear by an in situ nucleic acid hybridization technique in plastic embedded bony material

    OpenAIRE

    Falser, N; Bandtlow, I.; M. Hausmann; Wolf, Hans J.

    1986-01-01

    This investigation is concerned with the possibility of identifying viral DNA using the in situ DNA hybridization method in methylmethacrylate-embedded material. As an experimental model we chose viral labyrinthitis produced by intranasal infection of the mouse with pseudorabies virus. Fixation and embedding methods specially adapted to this procedure and bony histology preparation technique (specimens by grinding or micromilling) made it possible to identify viral DNA directly morphologicall...

  5. Design of Power System Stabilizer using Fuzzy Based Sliding Mode Control Technique

    OpenAIRE

    Latha, R.; S.KANTHALAKSHMI; Kanagaraj, J.

    2014-01-01

    Power systems are usually large non-linear systems, which are often subjected to low frequency electromechanical oscillations. Power System Stabilizers are often used as effective and economic means for damping the generator's electromechanical oscillations and enhance the overall stability of power systems. Power system stabilizers have been applied for several decades in utilities and they can extend power transfer stability limits by adding modulation signal through excit...

  6. A new contact electric resistance technique for in-situ measurement of the electric resistance of surface films on metals in electrolytes at high temperatures and pressures

    International Nuclear Information System (INIS)

    Surface films play a major role in corrosion assisted cracking. A new Contact Electric Resistance (CER) method has been recently developed for in situ measurement of the electric resistance of surface films. The method has been upgraded for high temperature high pressure application. The technique can be used for any electrically conductive material in any environment including liquid, gas or vacuum. The technique has been used to determine in situ the electric resistance of films on metals during adsorption of water and anions, formation and destruction of oxides and hydrides, electroplating of metals and to study the electric resistance of films on semiconductors. The resolution of the CER technique is 10-9 ?, which corresponds to about 0.03 monolayers of deposited copper during electrochemical deposition Cu/Cu2+. Electric resistance data can be measured with a frequency of the order of one hertz, which enables one to follow in situ the kinetics of surface film related processes. The kinetics of these processes and their dependence on the environment, temperature, pH and electrochemical potential can be investigated

  7. A comparison of the mechanical stability of silicon nitride films deposited with various techniques

    International Nuclear Information System (INIS)

    Highlights: ? LPCVD, RTCVD and ALD as-deposited nitride films present tensile stress dependant on the Si/N ratio and are thermally stable. ? Stress of as-deposited PECVD nitride layers range from compressive to tensile, depending on ion bombardment during growth. ? After high temperature annealing, PECVD nitride films behave similarly to LPCVD layers. ? Young's moduli and density are positively correlated. - Abstract: A comparison of mechanical properties of amorphous silicon nitride thin films deposited with various techniques used for microelectronic applications was conducted. Nitride films with thicknesses less than 80 nm were deposited on (0 0 1) oriented silicon wafers by using various methods: low pressure chemical vapor deposition (LPCVD), rapid thermal CVD (RTCVD), atomic layer deposition (ALD) and plasma enhanced CVD (PECVD). The wafer curvature method was used to show that the as-deposited LPCVD, RTCVD and ALD films exhibited tensile residual stresses that decreased with silicon richness. In contrast, the stress of the PECVD as-deposited layers ranged from tensile to ultra-compressive, depending on the exposure to high plasma power and ion bombardment during growth. After high temperature annealing, the LPCVD, RTCVD and ALD nitride stresses were almost unchanged, indicating that these films/substrate systems have significant thermal mechanical stability. In contrast, it was observed that, regardless of the initial stress, the annealed PECVD films developed tensile stress after high temperature treatment, with the same dependence of stress on refractive index as was found with the other deposition techniques. The Young's moduli, measured by performing nano-indentation on 200 nm thick nitride layers, were found for most samples to be correlated with film density.

  8. Laser frequency stabilization and large detuning by Doppler-free dichroic lock technique: Application to atom cooling

    Indian Academy of Sciences (India)

    V B Tiwari; S R Mishra; H S Rawat; S Singh; S P Ram; S C Mehendale

    2005-09-01

    We present results of a study of frequency stabilization of a diode laser ($\\lambda = 780$ nm) using the Doppler-free dichroic lock (DFDL) technique and its use for laser cooling of atoms. Quantitative measurements of frequency stability were performed and the Allan variance was found to be $6.9 \\times 10^{?11} for an averaging time of 10 s. The frequency-stabilized diode laser was used to obtain the trapping beams for a magneto-optic trap (MOT) for Rb atoms. Using the DFDL technique, the laser frequency could be locked over a wide range and this enabled measurement of detuning dependence of the number and temperature of cold atoms using a relatively simple experimental set-up.

  9. Long-term Stabilization of Fiber Laser Using Phase-locking Technique with Ultra-low Phase Noise and Phase Drift

    CERN Document Server

    Hou, Dong; Zhang, Shuangyou; Wu, Jiutao; Zhao, Jianye

    2014-01-01

    We review the conventional phase-locking technique in the long-term stabilization of the mode-locked fiber laser and investigate the phase noise limitation of the conventional technique. To break the limitation, we propose an improved phase-locking technique with an optic-microwave phase detector in achieving the ultra-low phase noise and phase drift. The mechanism and the theoretical model of the novel phase-locking technique are also discussed. The long-term stabilization experiments demonstrate that the improved technique can achieve the long-term stabilization for the MLFL with ultra-low phase noise and phase drift. The excellent locking performance of the improved phase-locking technique implies that this technique can be used to stabilize the mode-locked fiber laser with the highly stable H-master or optical clock without stability loss.

  10. Electronic conductivity measurement of yttria-stabilized zirconia solid electrolytes by a transient technique

    Science.gov (United States)

    Zhang, Lei; Zhu, Liangzhu; Virkar, Anil V.

    2016-01-01

    A new oxygen permeation technique is developed to measure the electronic conductivity of yttria-stabilized zirconia (YSZ). The permeation cell is a YSZ disc with an embedded Pt probe and a cavity at the center. Two porous platinum electrodes are applied on the disc surfaces. By applying a small DC bias (0.03 V) across one surface electrode and the embedded probe, oxygen is pumped into the YSZ disc and stored in the cavity. In steady state, a stable Nernst potential is developed between the cavity and the outer surfaces. The Nernst voltage is very close to the applied voltage since YSZ is essentially an ionic conductor. When the DC bias is removed, oxygen permeates out of the cavity leading to a decay of the Nernst potential. Electronic conductivity of YSZ corresponding to the ambient oxygen pressure (?0.21 atm) is determined by analyzing the time dependence of the decay of Nernst potential. The measured electronic conductivity is in good agreement with values reported in the literature.

  11. Research and test for depressing radioactive dust and radon daughters and radioactive aerosols in situ with the technique of supervoltage static electricity

    International Nuclear Information System (INIS)

    In some working-place of underground uranium mines and mills, the concentration of uranium ore dust, radon daughters and radioactive aerosols are very high. With conventional ventilation methods for eliminating these hazard materials, the efficiency is low, wherefore much more electric energy has to be consumed. A technique using supervoltage static electricity for depressing such hazard materials in situ is developed through tests. The technique has found a novel way to dust protection and radon elimination in the course of uranium mining and metallurgy

  12. In Situ Nitroxide-Mediated Polymerized Poly(acrylic acid) as a Stabilizer/Compatibilizer Carbon Nanotube/Polymer Composites

    OpenAIRE

    Laurence Couvreur; Olivier Guerret; Sylvain Bourrigaud; Nicolas Passade-Boupatt; Sylvie Dagréou; Christelle Guerret-Piécourt; Laurent Billon; Vitaliy Datsyuk

    2007-01-01

    Carbon nanotube (CNT) polymer composites were synthesized via in situ nitroxide-mediated diblock copolymerization. Poly(acrylic acid) (PAA) was chosen as a first block to obtain a precomposite CNT-PAA which is readily dispersible in various solvents including water. The immobilization of the stable poly(acrylic acid) alkoxyamine functionality on the nanotube surface occurs during the synthesis of the first block without CNT prior treatment. The living character of this block is established b...

  13. Effects of microbial inoculant on composition, aerobic stability, in situ ruminal degradability and in vitro gas production of corn silage

    OpenAIRE

    Bayatkouhsar et al.

    2012-01-01

    In this study, two fresh culture multistrains were produced and tested on corn silage; homofermentative and hetrofermentative from commercially and laboratory produced inoculants. Chemical properties and characteristics of silage samples were determined in mini- silos for 7, 14, 28, 45 and 90 days (triplicate per treatment). In situ ruminal degradability of DM and CP and in vitro gas production of fresh forage and silage (45 and 90 day silage) were investigated. There were differences between...

  14. Report of the first research co-ordination meeting under co-ordinated research project on 'In situ applications of XRF techniques'

    International Nuclear Information System (INIS)

    X-ray fluorescence is a well-established analytical technique widely used in industrial and research applications for materials characterisation. However, a relatively recent development has been the availability of portable instrumentation, which can be used for both the direct in situ non-destructive analysis of samples, and also is readily transportable to field sites for use in a 'mobile laboratory' style of operation. In situ analyses using the XRF technique can make an essential contribution to a wide range of projects, including: - Analysis of soils, particularly in the assessment of agricultural land and contaminated land - Sorting scrap metal alloys and plastics to increase the value of recyclable materials - Geochemical mapping and exploration to locate mineralisation deposits - Environmental monitoring related to air pollution studies and contamination of the work - The on-line control of industrial processes for the production of raw materials - Archaeological studies and the classification of artefacts, the restoration of sculptures, paintings and other objects of cultural heritage. - In situ geochemical studies on Mars, including the 1997 NASA Pathfinder mission and the forthcoming European Space Agency Mars Express mission, which includes the In these applications, the major advantages of field-portable X-ray fluorescence (FPXRF) spectrometry include: on-site immediate availability of analytical results, non-destructive analysis, a multielement capability, speed of operation and access to valuable/unique samples that otherwise would be unavailable for chemical analysis. The CRP on 'In situ applications of XRF techniques' is one element of the project on Nuclear Instruments for Specific Applications the major objective of which is to assist Member States in the development of nuclear instruments and software for special applications, such as the characterisation of materials. An overall objective of this CRP is to assist laboratories in Member States in such areas as environmental pollution monitoring, mineral exploration, the preservation of cultural heritage, the control of industrial processes and the optimisation of analytical methodologies for these applications using FPXRF

  15. Detection of Chromosomal Abnormalities with Different In Situ Hybridisation Techniques--the Usefulness in the Qualification of Cancer Patients for Molecularly-Targeted Therapies.

    Science.gov (United States)

    Nico?, Marcin; Wojas-Krawczyk, Kamila; Krawczyk, Pawe?; Milanowski, Janusz

    2015-01-01

    Proper qualification of patients with cancer for an effective treatment regiment is essential to rationalize therapy benefit and costs. The early detection of genetic disorders that are responsible for the stimulation of uncontrolled cancer cells proliferation makes it possible to select a group of patients with a high probability of response to molecularly-targeted therapy. Data has shown that careful analysis of genes mutation using different PCR and sequencing techniques or chromosomal aberrations using in situ hybridization (ISH) techniques have a predictive value for drug targeted therapy. Overexpression of receptors and gene amplification has been reported in various cancers. Their detection is still a considerable challenge, which is connected with the unsatisfactory quality of DNA and low mutated cells percentage compared to cells with no genetic abnormalities in tested material. Different techniques of standardization were performed to prevent false negative results and to increase the sensitivity of qualitative and quantitative evaluation of chromosomal abnormalities. Immunohistochemistry (IHC) technique is useful in the screening of receptor expression in paraffin-embedded tissue samples in different malignant diseases. Whereas ISH techniques, especially fluorescence in situ hybridization (FISH), are now considered the diagnostic gold standard method in detection chromosomal aberrations. Moreover, molecular biology techniques, which are using molecular probes and real-time PCR and quantitative PCR techniques, were also applied for the detection of chromosomal changes. In order to identify the best genetic marker for treatment regiment, it is important to compare results of different studies, which are evaluating the sensitivity of diagnostic techniques and treatment response after a suitable selection factors based on genetic aberrations profile. PMID:26469118

  16. Remediation of a soil contaminated with mineral oil below a production hall with the help of a microbiological in-situ technique; Sanierung eines Mineraloel-kontaminierten Bodens unterhalb einer Produktionshalle mit Hilfe eines mikrobiologischen In-situ-Verfahrens

    Energy Technology Data Exchange (ETDEWEB)

    Held, T.; Stahlmann, J.; Doerr, H. [Trischler und Partner GmbH, Darmstadt (Germany)

    1998-09-01

    Due to accidents and leakages of hydraulical machines the production hall of a plastics processing factory, hydraulic oil escaped from the machines over a long period of time. The oil migrated through gaps and joints in the concrete floor and led to a contamination of the soil below. A microbiolgocial in-situ technique (bioventing) for remediation of the contamination demands the addition of oxygen to the soil vapour. The inflow of oxygen takes place as the result of the soil vapour extraction process, which causes an underpressure in the subsoil. This initiates the inflow of atmospheric air. Furthermore, the microbiological breakdown of the oil requires the supplementation of nutrients. In the course of preliminary investigations to evaluate the feasibility of the technique and to determine the parameters for the technological components, several characteristics were determined, i.e. the radius of influence of the soil vapour extraction well, the hydraulical permeability, the sensitivity of the soil to consolidation settlement, and the microbial degradability of the oil. The technique was set up at the site beginning of 1997 followed by an optimization phase. The microbial pollution degradation can be monitored by an in-situ respiration test. The results led to the assumption that the remediation target values will be reached within a period of five years without any significant influence on the production process. (orig.) [Deutsch] In der Produktionshalle einer kunststoffverarbeitenden Fabrik kam es in der Vergangenheit zu Leckagen und Unfaellen an den hydraulischen Maschinen, in deren Folge ueber einen langen Zeitraum Hydraulikoel ausgetreten war. Ueber Undichtigkeiten wie Ritzen und Fugen des Betonfussbodens gelangte das Hydraulikoel in das darunterliegende Erdreich. Die Realisierung eines mikrobiologischen In-situ-Verfahrens (Bioventing) zur Sanierung eines solchen Schadens erfordert die Zufuehrung von Sauerstoff in den Untergrund. Dies wird mittels Bodenluftabsaugung erreicht. Durch die Absaugung entsteht ein Unterdruck, in dessen Folge atmosphaerische Luft in den Boden nachstroemt. Ferner ist zum mikrobiellen Schadstoffabbau die Infiltration von Naehrsalz-Loesungen erforderlich. Im Rahmen der Voruntersuchungen zur Bewertung der Machbarkeit des Verfahrens sowie zur Auslegung der verfahrenstechnischen Komponenten wurden unter anderem folgende Parameter ermittelt: Reichweite der Bodenluftabsaugpegel, hydraulische Durchlaessigkeit, Setzungsempfindlichkeit und mikrobiologische Abbaubarkeit. Das Verfahren wurde Anfang 1997 am Standort realisiert und zwischenzeitlich optimiert. Der mikrobielle Schadstoffabbau laesst sich anhand von In-situ-Respirationstests verfolgen. Die Ergebnisse lassen den Schluss zu, dass nach etwa fuenf Jahren Sanierungszeit die vorgegebenen Sanierungszielwerte erreicht sein werden, ohne dass es zu einer nachhaltigen Beeinflussung der Produktion kommt. (orig.)

  17. Long-term Stabilization of Fiber Laser Using Phase-locking Technique with Ultra-low Phase Noise and Phase Drift

    OpenAIRE

    Hou, Dong; Ning, Bo(Department of Physics, National Taiwan Normal University, Taipei, 116, Taiwan); Zhang, Shuangyou; Wu, Jiutao; Zhao, Jianye

    2014-01-01

    We review the conventional phase-locking technique in the long-term stabilization of the mode-locked fiber laser and investigate the phase noise limitation of the conventional technique. To break the limitation, we propose an improved phase-locking technique with an optic-microwave phase detector in achieving the ultra-low phase noise and phase drift. The mechanism and the theoretical model of the novel phase-locking technique are also discussed. The long-term stabilization ...

  18. In situ studies of lithium-ion diffusion in a lithium-rich thin film cathode by scanning probe microscopy techniques.

    Science.gov (United States)

    Yang, Shan; Yan, Binggong; Li, Tao; Zhu, Jing; Lu, Li; Zeng, Kaiyang

    2015-09-14

    This paper presents in situ characterization of lithium-ion diffusion at nano- to micro-meter scales in a Li-rich layered oxide thin film cathode under external bias by using Electrochemical Strain Microscopy (ESM) and Atomic Force Microscopy (AFM) techniques. The local variations of the diffusion coefficient are calculated and visualized from the ESM images. The results indicate that the Li-ion movement is closely correlated with the changes in the surface topography when the Li-rich cathode is subjected to an external bias. Furthermore, bias-induced Li-ion redistribution is partially reversible. Topography evolution due to Li-ion diffusion and relaxation behaviour are observed. The results from this in situ study provide the insight into the Li-ion diffusion mechanism in the cathode material and pave the way for studying the details of the diffusion-related phenomenon in Li-ion battery materials. PMID:26242479

  19. Thermal stability and long term hydrogen/deuterium release from soft to hard amorphous carbon layers analyzed using in-situ Raman spectroscopy. Comparison with Tore Supra deposits

    CERN Document Server

    Pardanaud, C; Giacometti, G; Mellet, N; Pégourié, B; Roubin, P

    2015-01-01

    The thermal stability of 200 nm thick plasma enhanced chemical vapor deposited a-C:H and a-C:D layers ranging from soft to hard layers has been studied and compared to that of deposits collected on the Tore Supra tokamak plasma facing components by means of in-situ Raman spectroscopy. Linear ramp heating and long term isotherms (from several minutes to 21 days) have been performed and correlations between spectrometric parameters have been found. The information obtained on the sp 2 clustering has been investigated by comparing the G band shift and the 514 nm photon absorption evolution due to the thermal treatment of the layer. The effects of isotopic substitution have also been investigated.

  20. In situ non-DLVO stabilization of surfactant-free, plasmonic gold nanoparticles: effect of Hofmeister's anions.

    Science.gov (United States)

    Merk, Vivian; Rehbock, Christoph; Becker, Felix; Hagemann, Ulrich; Nienhaus, Hermann; Barcikowski, Stephan

    2014-04-22

    Specific ion effects ranking in the Hofmeister sequence are ubiquitous in biochemical, industrial, and atmospheric processes. In this experimental study specific ion effects inexplicable by the classical DLVO theory have been investigated at curved water-metal interfaces of gold nanoparticles synthesized by a laser ablation process in liquid in the absence of any organic stabilizers. Notably, ion-specific differences in colloidal stability occurred in the Hückel regime at extraordinarily low salinities below 50 ?M, and indications of a direct influence of ion-specific effects on the nanoparticle formation process are found. UV-vis, zeta potential, and XPS measurements help to elucidate coagulation properties, electrokinetic potential, and the oxidation state of pristine gold nanoparticles. The results clearly demonstrate that stabilization of ligand-free gold nanoparticles scales proportionally with polarizability and antiproportionally with hydration of anions located at defined positions in a direct Hofmeister sequence of anions. These specific ion effects might be due to the adsorption of chaotropic anions (Br(-), SCN(-), or I(-)) at the gold/water interface, leading to repulsive interactions between the partially oxidized gold particles during the nanoparticle formation process. On the other hand, kosmotropic anions (F(-) or SO4(2-)) seem to destabilize the gold colloid, whereas Cl(-) and NO3(-) give rise to an intermediate stability. Quantification of surface charge density indicated that particle stabilization is dominated by ion adsorption and not by surface oxidation. Fundamental insights into specific ion effects on ligand-free aqueous gold nanoparticles beyond purely electrostatic interactions are of paramount importance in biomedical or catalytic applications, since colloidal stability appears to depend greatly on the type of salt rather than on the amount. PMID:24720469

  1. Measurement of Bluetongue Virus Binding to a Mammalian Cell Surface Receptor by an In Situ Immune Fluorescent Staining Technique

    Science.gov (United States)

    A quantifiable in situ immune fluorescent assay (IFA) was developed to measure bluetongue virus (BTV) binding to mammalian cells. The utility of the assay was demonstrated with both Chinese hamster ovary (CHO) and bovine pulmonary artery endothelial (CPAE) cells. Since heparin sulfate (HS) has been ...

  2. The search for stability: bar displacement in three series of pectus excavatum patients treated with the Nuss technique

    Scientific Electronic Library Online (English)

    Miguel Lia, Tedde; Jose Ribas Milanez de, Campos; João-Carlos, Das-Neves-Pereira; Fernando Conrado, Abrao; Fábio Biscegli, Jatene.

    Full Text Available OBJECTIVES: To compare bar displacement and complication rates in three retrospective series of patients operated on by the same surgical team. METHOD: A retrospective medical chart analysis of the three patient series was performed. In the first series, the original, unmodified Nuss technique was p [...] erformed. In the second, we used the ''third point fixation'' technique,and in the last series, the correction was performed with modifications to the stabilizer and stabilizer position. RESULTS: There were no deaths in any of the series. Minor complications occurred in six (4.9%) patients: pneumothorax with spontaneous resolution (2), suture site infection (2), and bar displacement without the reoperation need (2). Major complications were observed in eight (6.5%) patients: pleural effusion requiring drainage (1), foreign body reaction to the bar (1), pneumonia and shock septic (1), cardiac perforation (1), skin erosion/seroma (1), and displacement that necessitated a second operation to remove the bar within the 30 days of implantation (3). All major complications occurred in the first and second series. CONCLUSION: The elimination of fixation wires, the use of shorter bars and redesigned stabilizers placed in a more medial position results in a better outcome for pectus excavatum patients treated with the Nuss technique. With bar displacement and instability no longer significant postoperative risks, the Nuss technique should be considered among the available options for the surgical correction of pectus excavatum in pediatric patients.

  3. Importance of shale anisotropy in estimating in-situ stresses and wellbore stability analysis in Horn River basin

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Safdar; Ansari, Sajjad; Han, Hongxue; Khosravi, Nader [Schlumberger (United States)

    2011-07-01

    The importance of understanding shale formation anisotropic behavior prior to drilling was discussed in this paper. The objective of this work is to show how shale anisotropy is often not taken into consideration in conventional wellbore analysis, and how this practice might lead to serious consequences and instabilities in the wellbore system. Two fields in the Horn River basin area were investigated. The laminated structures of the shale were explained and the mechanical properties including in-situ stresses, directional variations, and horizontal and vertical Young's modulus were calculated. In general the investigated region proved to be highly anisotropic. It was proposed that this phenomenon was the main reason for discrepancies in mechanical properties along the parallel and perpendicular directions of the planes. Moreover, it was shown that not taking anisotropic effects into consideration can cause miscalculations of in-situ stresses and breakdown pressure; hence, causing instabilities in the wellbore system. Therefore, anisotropic analysis was recommended as an important step in designing wells.

  4. In-situ measurement of the effect of LiOH on the stability of fuel cladding oxide film in simulated PWR primary water environment

    International Nuclear Information System (INIS)

    Development of new improved fuel cladding materials is a long process, partly because of the lack of fast and reliable in-situ techniques for investigations of cladding degradation in high temperature water environments. This paper describes results gained with the Contact Electric Resistance (CER) technique on the electric resistance of oxides growing on zirconium based fuel cladding materials. LiOH decreased the electric resistance of the oxides when about 70 ppm was injected in PWR water at 300 C. When PWR water contains boric acid and LiOH from the beginning of the exposure the fuel cladding material is covered by a hydroxide layer that protects the amorphous oxide layer and later hinders the increase of the resistance of the crystalline oxide layer. The dependency of electric resistance of the oxides on LiOH concentration is shown to correlate inversely with the effect of LiOH on weight gain. The kinetics of the breakdown process of electric resistance indicate that a phase transformation rather than a diffusion limited process is the mechanism of degradation. The growth rate of the electric resistance of the oxide in the early stage of oxide formation is shown to correlate well with the in-reactor weight gain of similar alloys. In-situ monitoring of the electric resistance of the oxide during growth is shown to give the same ranking order as long term in-reactor weight gain tests, but in a fraction of the testing time needed for weight gain tests

  5. Comparative stability analyses of traditional and selective room-and-pillar mining techniques for sub-horizontal tungsten veins

    Science.gov (United States)

    Navarro Torres, Vidal Félix; Dinis da Gama, Carlos; Costa E Silva, Matilde; Neves, Paula Falcão; Xie, Qiang

    2011-02-01

    The stability and productivity concerning a modification on the traditional room and pillar for a new selective technique at the Portuguese Panasqueira Mine have been described. The traditional room-and-pillar stoping uses 5.0-m wide rooms with 3.0 m ×3.0 m pillars, while the selective room-and-pillar mining technique consists in stoping with rooms of 4.0 m wide and pillars of 4 m ×4 m with a subsequent selective cutting of the quartz veins at the mid pillar of approximately 0.5 m high, to obtain a pillar section with an area of 3.0 m × 3.0 m. The stability and productivity analyses indicate that the selective technique obtains smaller average pillar safety factor, more rock mass displacement, more extraction and selectivity ratios, and ore grade improvement, compared with the traditional technique. These results show that the selective technique is also more convenient. This proposed selective room-and-pillar mining technique is applicable to any sub-horizontal narrow quartz veins with wolfram, gold, etc. such as the famous La Rinconada gold mine in the Peruvian Andes.

  6. Robust Power System Stabilizer Design Using Genetic Local Search Technique for Single Machine Connected to an Infinite Bus

    Directory of Open Access Journals (Sweden)

    Mohamed Zellagui

    2008-09-01

    Full Text Available The genetic local search technique hybridizes the genetic algorithm and the local search (such as hill climbing in order to eliminate the disadvantages in genetic algorithm. The parameters of the power system stabilizer (gain, phase lead time constant are tuned by considering the single machine connected to infinite bus system. Here, power system stabilizer are used for damping low frequency local mode of oscillations. Eigen value analysis shows that the proposed GLSPSS based PSS have better performance compared with conventional and the Genetic Algorithm Based Power System Stabilizer (GAPSS. Integral of time multiplied absolute value of error (ITAE is taken as the performance index of the selected system. Genetic and Evolutionary Algorithm (GEA toolbox is used along with MATLAB/SIMULINK for simulation.

  7. Investigations on dry sliding wear behavior of in situ casted AA7075–TiC metal matrix composites by using Taguchi technique

    International Nuclear Information System (INIS)

    Highlights: • The AA7075–TiC metal matrix composites were produced by in situ casting technique. • The produced composites were characterized by XRD analysis and SEM. • The dry sliding wear behavior of composites was investigated by Taguchi technique. • The significant factors and their contribution in wear rate identified by ANOVA. • The formation of oxidation at high sliding velocity was verified by EDS. - Abstract: High strength 7075 aluminum matrix composites with 4 and 8 wt.% of TiC particulate reinforcement was synthesized by reactive in situ casting technique. X-ray diffraction analysis and scanning electron microscopy were used to confirm the presence of TiC particles and its uniform distribution over the aluminum matrix. The dry sliding wear behavior of the as-casted composites was investigated based on Taguchi L27 orthogonal array experimental design to examine the significance of reinforcement quantity, load, sliding velocity and sliding distance on wear rate. The combination of 4 wt.% of TiC, 9.81 N load, 3 m/s sliding velocity and 1500 m sliding distance was identified as the optimum blend for minimum wear rate using the main effect plot. Load and sliding velocity were identified as the highly contributing significant parameters on the wear rate using ANOVA analysis. Further a confirmation test was also conducted with the optimum parameter combination for validation of the Taguchi results

  8. A post-processing technique for stabilizing the discontinuous pressure projection operator in marginally-resolved incompressible inviscid flow

    CERN Document Server

    Joshi, Sumedh M; Steinmoeller, Derek T; Stastna, Marek; Thomsen, Greg N

    2015-01-01

    A method for post-processing the velocity after a pressure projection is developed that helps to maintain stability in an under-resolved, inviscid, discontinuous element-based simulation for use in environmental fluid mechanics process studies. The post-processing method is needed because of spurious divergence growth at element interfaces due to the discontinuous nature of the discretization used. This spurious divergence eventually leads to a numerical instability. Previous work has shown that a discontinuous element-local projection onto the space of divergence-free basis functions is capable of stabilizing the projection method, but the discontinuity inherent in this technique may lead to instability in under-resolved simulations. By enforcing inter-element discontinuity and requiring a divergence-free result in the weak sense only, a new post-processing technique is developed that simultaneously improves smoothness and reduces divergence in the pressure-projected velocity field at the same time. When com...

  9. High sensitive diagnostic technique for virus gene using radioisotope. Development of PCR in situ hybridization and its application

    International Nuclear Information System (INIS)

    An animal model, experimentally induced squamous cell carcinoma was produced in hamster mucosa to establish a carcinogenic system inducible by interaction of a virus and chemical(s). Human hydatid mole and cholioepithelioma were chosen as the target subjects. Several tumor cells and host cells were isolated under microscopy and DNA was extracted from these cells to indentify the respective origins (maternal, paternal or host origin). The base sequence of HLADRB region was analyzed by PCR using synthetic primer and the tissue localization was examined by PCR in situ hybridization. A PCR product of 82 bp was found in 15 of 17 samples and there were 2 samples in which the product was not detectable with the constructed primer and 6 samples were negative. While significant differences were not observed by in situ hybridization compared with the negative control. (M.N.)

  10. Routine growth of InP based device structures using process calibration with optical in-situ techniques

    Science.gov (United States)

    Wolfram, P.; Steimetz, E.; Ebert, W.; Grote, N.; Zettler, J.-T.

    2004-12-01

    Combined reflectance R and reflectance anisotropy spectroscopy (RAS) was applied for in situ monitoring of composition and growth rate of MOVPE grown In 1-xGa xAs 1-yP y layers lattice matched to InP. The sum of the surface sensitive RAS signals at 1.75 and 2.65 eV associated with the phosphorus to arsenic ratio was used to evaluate the composition parameters x and y calibrated by ex situ measurements. For fixed MOVPE growth conditions, the ratio of the growth rates of InGaAsP and InP growth rate, calculated from the reflectance signals, directly corresponds to the gallium-to-indium ratio of the InGaAsP-layers.

  11. High sensitive diagnostic technique for virus gene using radioisotope. Development of PCR in situ hybridization and its application

    Energy Technology Data Exchange (ETDEWEB)

    Iwasaki, Takuya; Sada, Tetsutaro; Terai, Masanori; Sato, Yuko; Kurata, Takeshi [National Inst. of Infectious Diseases, Tokyo (Japan); Yamaguchi, Kazuyoshi; Yanagisawa, Akio; Sakai, Yuzo

    1998-02-01

    An animal model, experimentally induced squamous cell carcinoma was produced in hamster mucosa to establish a carcinogenic system inducible by interaction of a virus and chemical(s). Human hydatid mole and cholioepithelioma were chosen as the target subjects. Several tumor cells and host cells were isolated under microscopy and DNA was extracted from these cells to indentify the respective origins (maternal, paternal or host origin). The base sequence of HLADRB region was analyzed by PCR using synthetic primer and the tissue localization was examined by PCR in situ hybridization. A PCR product of 82 bp was found in 15 of 17 samples and there were 2 samples in which the product was not detectable with the constructed primer and 6 samples were negative. While significant differences were not observed by in situ hybridization compared with the negative control. (M.N.)

  12. Thermal stability and kinetic study of poly(ethyl methacrylate-co-acrylonitrile) nanocomposites prepared by in situ polymerization in presence of an Algerian bentonite

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • poly(ethyl methacrylate-co-acrylonitrile) nanocomposites were successfully prepared. • These nanocomposites were of higher Tg and improved thermal stability. • Their (E?) of thermal decomposition were higher than those of the virgin copolymer. • Increase of (E?), confirmed change in the degradation mechanism with clay loading. - Abstract: Poly(ethyl methacrylate-co-acrylonitrile) (PEAMN20) nanocomposites were successfully prepared via free radical in situ polymerization using a bentonite from Algeria modified by Hexadecyltrimethylammonium chloride (HDTMA). X-ray diffraction (XRD) and transmission electronic microscopy (TEM) investigations revealed that depending on the OMMT loading, intercalated or partially exfoliated nanocomposites were obtained. These nanocomposites exhibited an overall improved thermal stability and an increase in their glass transition temperature compared to the pure copolymer (PEMAN20) as evidenced by Thermogravimetric (TGA) and Differential Scanning Calorimetry (DSC) analysis. Apparent activation energies (E?) of thermal decomposition of the elaborated nanocomposites, determined by Tang method, were higher than those of the virgin copolymer. The significant increase of (E?), observed with PEMAN20/OMMT (1 wt%) confirmed the change in the degradation mechanism with OMMT loading and the ratio of intercalated/exfoliated structures

  13. Thermal stability and kinetic study of poly(ethyl methacrylate-co-acrylonitrile) nanocomposites prepared by in situ polymerization in presence of an Algerian bentonite

    Energy Technology Data Exchange (ETDEWEB)

    Kadi, Souad [Université des Sciences et de la Technologie Houari Boumediene, Laboratoire des Matériaux Polymères, Faculté de Chimie, BP 32 El-Alia, Bab-Ezzouar, 16111 Algiers (Algeria); Djadoun, Saïd, E-mail: matpolylab@yahoo.fr [Université des Sciences et de la Technologie Houari Boumediene, Laboratoire des Matériaux Polymères, Faculté de Chimie, BP 32 El-Alia, Bab-Ezzouar, 16111 Algiers (Algeria); Sbirrazzuoli, Nicolas [Univ. Nice Sophia Antipolis, CNRS, LPMC, UMR 7336, 06100 Nice (France)

    2013-10-10

    Graphical abstract: - Highlights: • poly(ethyl methacrylate-co-acrylonitrile) nanocomposites were successfully prepared. • These nanocomposites were of higher T{sub g} and improved thermal stability. • Their (E{sub ?}) of thermal decomposition were higher than those of the virgin copolymer. • Increase of (E{sub ?}), confirmed change in the degradation mechanism with clay loading. - Abstract: Poly(ethyl methacrylate-co-acrylonitrile) (PEAMN20) nanocomposites were successfully prepared via free radical in situ polymerization using a bentonite from Algeria modified by Hexadecyltrimethylammonium chloride (HDTMA). X-ray diffraction (XRD) and transmission electronic microscopy (TEM) investigations revealed that depending on the OMMT loading, intercalated or partially exfoliated nanocomposites were obtained. These nanocomposites exhibited an overall improved thermal stability and an increase in their glass transition temperature compared to the pure copolymer (PEMAN20) as evidenced by Thermogravimetric (TGA) and Differential Scanning Calorimetry (DSC) analysis. Apparent activation energies (E{sub ?}) of thermal decomposition of the elaborated nanocomposites, determined by Tang method, were higher than those of the virgin copolymer. The significant increase of (E{sub ?}), observed with PEMAN20/OMMT (1 wt%) confirmed the change in the degradation mechanism with OMMT loading and the ratio of intercalated/exfoliated structures.

  14. In situ green synthesis of silver–graphene oxide nanocomposites by using tryptophan as a reducing and stabilizing agent and their application in SERS

    International Nuclear Information System (INIS)

    Highlights: • Tryptophan (Trp) as a reducing and stabilizing agent was a green one-pot method. • The role of pH has been explored to obtain optimum reaction conditions during the growth process. • The synthesized Ag–GO nanocomposites exhibited excellent SERS activity. - Abstract: Silver–graphene oxide (Ag–GO) nanocomposites were in situ fabricated rapidly through a green one-pot method by using tryptophan (Trp) as a reducing and stabilizing agent. The morphologies of synthesized Ag–GO nanocomposites were characterized by UV–vis absorption spectroscopy, transmission electron microscopy (TEM), and micro-Raman system. The results indicated silver nanoparticles (Ag NPs) with spherical size were well dispersed on the surface of graphene oxide (GO). The role of pH has been explored to obtain optimum reaction conditions during the growth process. Raman signals of GO were greatly enhanced after Ag NPs loaded on its surface. More importantly, the synthesized Ag–GO nanocomposites exhibited excellent surface-enhanced Raman scattering (SERS) activity as SERS substrates to detect crystal violet (CV) in aqueous solution, and the enhancement factor (EF) from the intensity of the vibrational mode at 1621 cm?1 was calculated to be 1.6 × 105

  15. In situ green synthesis of silver–graphene oxide nanocomposites by using tryptophan as a reducing and stabilizing agent and their application in SERS

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Biwen; Liu, Zhiming; Guo, Zhouyi; Zhang, Wen; Wan, Mingming; Qin, Xiaochu; Zhong, Huiqing, E-mail: zhonghq@scnu.edu.cn

    2014-10-15

    Highlights: • Tryptophan (Trp) as a reducing and stabilizing agent was a green one-pot method. • The role of pH has been explored to obtain optimum reaction conditions during the growth process. • The synthesized Ag–GO nanocomposites exhibited excellent SERS activity. - Abstract: Silver–graphene oxide (Ag–GO) nanocomposites were in situ fabricated rapidly through a green one-pot method by using tryptophan (Trp) as a reducing and stabilizing agent. The morphologies of synthesized Ag–GO nanocomposites were characterized by UV–vis absorption spectroscopy, transmission electron microscopy (TEM), and micro-Raman system. The results indicated silver nanoparticles (Ag NPs) with spherical size were well dispersed on the surface of graphene oxide (GO). The role of pH has been explored to obtain optimum reaction conditions during the growth process. Raman signals of GO were greatly enhanced after Ag NPs loaded on its surface. More importantly, the synthesized Ag–GO nanocomposites exhibited excellent surface-enhanced Raman scattering (SERS) activity as SERS substrates to detect crystal violet (CV) in aqueous solution, and the enhancement factor (EF) from the intensity of the vibrational mode at 1621 cm{sup ?1} was calculated to be 1.6 × 10{sup 5}.

  16. Facile in situ characterization of gold nanoparticles on electrode surfaces by electrochemical techniques: average size, number density and morphology determination.

    OpenAIRE

    Wang, Y; Laborda, E; Salter, C.; Crossley, A.; Compton, RG

    2012-01-01

    A fast and cheap in situ approach is presented for the characterization of gold nanoparticles from electrochemical experiments. The average size and number of nanoparticles deposited on a glassy carbon electrode are determined from the values of the total surface area and amount of gold obtained by lead underpotential deposition and by stripping of gold in hydrochloric acid solution, respectively. The morphology of the nanoparticle surface can also be analyzed from the "fingerprint" in lead d...

  17. Optical vernier technique for in-situ measurement of the length of long Fabry-Perot cavities

    OpenAIRE

    Rakhmanov, M.; Evans, M.; Yamamoto, H.

    1998-01-01

    We propose a method for in-situ measurement of the length of kilometer size Fabry-Perot cavities in laser gravitational wave detectors. The method is based on the vernier, which occurs naturally when the laser incident on the cavity has a sideband. By changing the length of the cavity over several wavelengths we obtain a set of carrier resonances alternating with sideband resonances. From the measurement of the separation between the carrier and a sideband resonance we det...

  18. THERMAL TECHNIQUES FOR THE IN-SITU CHARACTERIZATION AND REMEDIATION OF MERCURY: INSIGHTS FROM DEPLOYMENT OF THE MEMBRANE INTERFACE PROBE

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Dennis; Looney, Brian; Eddy-Dilek, Carol A.

    2013-08-07

    This presentation focuses on how thermal energy can effectively be used to enhance characterization, promote the remediation, and aid in delivering a sequestering agent to stabilize elemental mercury in subsurface soils. Slides and speaker notes are provided.

  19. Evaluation of some by-Products using In situ and In vitro Gas Production Techniques

    OpenAIRE

    Besharati Maghsoud; Taghizadeh Akbar; Janmohammadi Hossein; Moghadam G. Ali

    2008-01-01

    Food by-products in Iran are produced in high levels. In this study, in situ and in vitro gas production techniques were used to describe nutritive value of apple pomace, tomato pomace and noodle waste. For this purpose two ruminal fistulated sheep were used. Nylon bags which were approximately (6×12 cm) containing 5 g samples (2 mm screen) were incubated in duplicate in the rumen of fistulated sheep for 0,2,4,6,8,12,16,24,36 and 48 h. The gas production was recorded after 2, 4, 6, ...

  20. A novel fiber-optic photometer for in situ stability assessment of concentrated oil-in-water emulsions

    OpenAIRE

    Oliczewski, Susen; Daniels, Rolf

    2007-01-01

    The purpose of this research was to evaluate a novel fiberoptic photometer for its ability to monitor physical instabilities occurring in concentrated emulsions during storage. For this, the fiber-optic photometer was used to measure transmission of oil-in-water emulsions stabilized with hypromellose (HPMC) as a function of oil volume fraction and droplet size distribution (DSD). To detect physical instabilities like creaming and coalescence, the transmissivity of the samples was studied at 2...

  1. In situ synchrotron radiation grazing incidence X-ray diffraction-A powerful technique for the characterization of solid-state ion-selective electrode surfaces

    International Nuclear Information System (INIS)

    An in situ surface study of the iron chalcogenide glass membrane ion-selective electrode (ISE) in aqueous media has been undertaken using a tandem technique of mixed potential/synchrotron radiation grazing incidence X-ray diffraction (SR-GIXRD) and atomic force microscopy (AFM). This work has simultaneously monitored the mixed potential and in situ surface diffraction patterns of this crystalline glassy material, showing that the observed gradual shift of the electrode potential in the anodic direction is linked to the preferential dissolution of the GeSe (1 1 1), GeSe (1 0 1) and GeSe (1 4 1) and/or Sb2Se3 (0 1 3), Sb2Se3 (2 2 1) and Sb2Se3 (0 2 0) surfaces. Expectedly, these observations are internally consistent with preferential oxidative attack of the crystalline regions of the membrane comprising GeSe and/or Sb2Se3, as evidenced by AFM imaging of the electrode surface. Clearly, this work corroborates the results of previous ex situ surface studies on the iron chalcogenide glass ISE, whereby it was shown that alkaline saline solutions have a tendency to alter the surface chemistry and concomitant response characteristics of the ISE

  2. Determination Nutritional Value and Digestibility of Three Rangeland Plants of through Chemical Method and in Situ (Nylon Bags Techniques

    Directory of Open Access Journals (Sweden)

    Ali Ahmad Ghotbi

    2012-04-01

    Full Text Available This research has been conducted to evaluate nutritional value, digestibility and degradability of three rangeland species Dactylic glomereta, Onobrychis sativa and Setaria galauca through chemical and in situ methods. The experiment conducted based on Randomized Complete Design with three fistulated sheep in 3 replications and obtained data were analyzed by software SAS and Neway. Specifications such as Crude Protein (CP, Neutral Detergent Fiber (NDF, Acid Detergent Fiber (ADF, Ether Extract (EE, Ash, Crude Fiber (CF, NFC (Non Fiber Carbohydrate, Nitrogen Free Extract (NFE and organic material (OM were determined in chemical method and degradation of dry matter and protein were determined at times 0, 4, 8, 16, 24, 48, 72 and 96 through in situ method for the three species. O. sativa showed the most amount of crude protein (23.95% and the least amount of ADF. Also, S. galauca showed the least amount of protein (7.95% and the most amount of ADF (45.73%. Results of degradability in in-situ (nylon bags method show that S. galauca has the least and O. sativa has the most degradability of dry matter and protein. Results also show that O. sativa and D. glomereta have the capability of being applied as livestock food and S. galauca could be applied aslivestock food in combination with suitable species of legumes.

  3. Effect of hydrate formation-dissociation on emulsion stability using DSC and visual techniques

    Energy Technology Data Exchange (ETDEWEB)

    Lachance, J.W.; Dendy Sloan, E.; Koh, C.A. [Colorado School of Mines, Golden, CO (United States). Center for Hydrates Research

    2008-07-01

    Many flow assurance operators are now focusing on preventing hydrates from agglomerating and forming plugs within pipelines. A key factor in reducing plug formation in oil-dominated systems is the stability of emulsified water in gas hydrate formation. In this study, differential scanning calorimetry (DSC) studies were used to show that gas hydrate formation has a destabilizing effect on water and oil emulsions, and can result in a free water phase through the coalescence and agglomeration of dissociated hydrate particles. The study focused on investigating the ability of the hydrates to stay segregated with hydrate formation. The stability of water-in-oil emulsions with hydrate formation was investigated with a range of different crude oils with varying emulsion stability levels. Thermal properties were measured at both atmospheric and pressurized conditions. Thermocouples in the calorimetric furnace were used to measure the temperature difference between reference and sample cells. Emulsion stability was measured over a 1-month time period. Results of the study showed that hydrate formation and dissociation destabilizes emulsions. However, the asphaltene fraction in crude oils resists hydrate-induced destabilization. The stability of the emulsion increased when asphaltene content increased. It was concluded that emulsion stability is a key factor in preventing agglomeration in flow lines. 14 refs., 3 tabs., 8 figs.

  4. The influence of additives on the morphology and stability of roll-to-roll processed polymer solar cells studied through ex situ and in situ X-ray scattering

    DEFF Research Database (Denmark)

    Zawacka, Natalia Klaudia; Andersen, Thomas Rieks

    2014-01-01

    The effect of twelve different additives on organic solar cells with an active layer based on poly-3- hexylthiophene (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) has been studied in this work and tested for suitability in roll-to-roll slot-die coating. Three of the twelve additives increased the solar cell efficiency while the rest showed no effect or a negative influence on the efficiency and coatability. In cases where the additive caused an increase in performance the relation to surface topography and the structure was investigated using Atomic Force Microscopy (AFM), UV-Vis Spectroscopy and Small Angle X-ray Scattering (SAXS) for cells prepared with 1-chloronaphthalene (CN), N-methyl-2-pyrrolidone (NMP) and 1,3-dimethyl-barbituric acid (BARB) as processing additives. The studies suggested that the use of these additives resulted in films with improved morphology and electrical properties of the active layer. The effect of the CN on structural evolution during different solvent evaporation and annealing times was further investigated with an in situ roll-to-roll X-ray study. Lifetime studies under continuous illumination were used to assess the impact of the additives on the stability of the prepared devices that had an active area of 1 cm2.

  5. Polymer-metal interface bond stability

    Energy Technology Data Exchange (ETDEWEB)

    Boerio, J.

    1984-03-01

    An in-situ, non-destructive technique for determining stability of polymer/metal (oxide) interface is developed. The nature of degradation reactions occurring at polymer/metal (oxide) interface is determined and methods for inhibiting those reactions are developed.

  6. The radiation stability of glycine in solid CO2 - in situ laboratory measurements with applications to Mars

    CERN Document Server

    Gerakines, P A

    2015-01-01

    The detection of biologically important, organic molecules on Mars is an important goal that may soon be reached. However, the current small number of organic detections at the Martian surface may be due to the harsh UV and radiation conditions there. It seems likely that a successful search will require probing the subsurface of Mars, where penetrating cosmic rays and Solar energetic particles dominate the radiation environment, with an influence that weakens with depth. Toward the goal of understanding the survival of organic molecules in cold radiation-rich environments on Mars, we present new kinetics data on the radiolytic destruction of glycine diluted in frozen carbon dioxide. Rate constants were measured in situ with infrared spectroscopy, without additional sample manipulation, for irradiations at 25, 50, and 75 K with 0.8-MeV protons. The resulting half-lives for glycine in CO2-ice are compared to previous results for glycine in H2O-ice and show that glycine in CO2-ice is much less stable in a radia...

  7. In Situ Nitroxide-Mediated Polymerized Poly(acrylic acid as a Stabilizer/Compatibilizer Carbon Nanotube/Polymer Composites

    Directory of Open Access Journals (Sweden)

    Laurence Couvreur

    2007-11-01

    Full Text Available Carbon nanotube (CNT polymer composites were synthesized via in situ nitroxide-mediated diblock copolymerization. Poly(acrylic acid (PAA was chosen as a first block to obtain a precomposite CNT-PAA which is readily dispersible in various solvents including water. The immobilization of the stable poly(acrylic acid alkoxyamine functionality on the nanotube surface occurs during the synthesis of the first block without CNT prior treatment. The living character of this block is established by spectroscopic methods and the nature of the CNT/PAA interaction is discussed. This living first block offers the opportunity to reinitiate the polymerization of a second block that can be chosen among a wide range of monomers. This versatility is illustrated with a second block containing methyl acrylate (MA or styrene (S. Scanning and transmission electron microscopies confirm good CNT dispersion in the polymer network, while transmission electron microscopy also spots the anchorage locations of PAA on the CNT surface. Such nanotubes wrapped by diblock copolymers can be dispersed in various polymer matrices to create CNT—polymer composites. Conductivity measurements show that these composites obey a percolation-like power law with a low percolation threshold (less than 0.5 vol% and a high maximum conductivity (up to 1.5 S/cm at room temperature.

  8. Study on development of evaluation technique of in-situ tracer test in Horonobe Underground Research Laboratory project (Contract research)

    International Nuclear Information System (INIS)

    In the Horonobe Underground Research Laboratory Project, in-situ tracer tests are valuable and important as the investigations to obtain the mass transportation data of fractures in hostrock. However, it is difficult that the in-situ tests are executed under various conditions due to long test period and the tests results are evaluated about permeable heterogeneity in a fracture and/or scale effects. In this study, a number of tracer tests are simulated in a fictitious single plate fracture generated on computer. And the transport parameters are identified by fitting one- and two-dimensional models to the breakthrough curves obtained from the simulations in order to investigate the applicability of these models to the evaluation of in-situ tracer test. As a result, one-dimensional model yields larger longitudinal dispersion length than two-dimensional model in the both cases of homogeneous and heterogeneous hydraulic conductivity fields of the fictitious fracture. This is because that the effect of transverse dispersion has to be included in the longitudinal dispersion length parameter in the one-dimensional model. It is also found that the larger dipole ratio and the larger natural groundwater flow crossing the flow generated between two boreholes make the identified longitudinal dispersion length larger. And, the longitudinal dispersion length identified from a tracer test is smaller and/or larger than the macroscopic longitudinal dispersion length identified from whole fracture. It is clarified that these are occurred by shorter or longer distance between boreholes compare to the correlation length of geostatistical heterogeneity of fictitious fracture. (author)

  9. Development of new methods for assessing solidification/stabilization of hazardous waste using solid-state nuclear magnetic resonance techniques

    International Nuclear Information System (INIS)

    New methods for assessing solidification/stabilization (S/S) of hazardous waste using solid-state nuclear magnetic resonance are developed for the purpose of diagnosing on a microscopic level the performance of S/S as a hazardous waste disposal technique. There are four techniques developed and described in this dissertation: (1) Solid-state deuterium NMR spectroscopy is used to determine if a particular deuterated organic waste is effectively solidified/stabilized and to determine the lower limit of the bond strength between the waste and the cement matrix; (2) Constant time pulsed field gradient 1H NMR spectroscopy is tested on a liquid waste encapsulated within a solidified matrix to determine if droplets of liquid waste are entrapped within a solidified matrix. It yields a size distribution image of vesicles containing fluids, and measures the diffusion rate of organic materials in solid matrices; (3) Three-dimensional NMR imaging of a hazardous waste/cement sample is tested for the determination of the pore structure connectivity pattern and the observation of waste leaching; (4) NMR hole-burning spectroscopy is attempted for the study of the microscopic motions of waste in the cement matrix. These NMR techniques give information on the microscopic waste/cement interactions while providing a nondestructive evaluation of the quality of S/S process much superior to the destructive techniques such as leaching

  10. In Situ Stabilization of Inactive Low Level Waste Pipelines in the Melton Valley Watershed at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    The Melton Valley watershed at Oak Ridge National Laboratory (ORNL) contained an inactive waste pipeline system consisting of approximately 12 kilometers of buried waste pipelines and over 142 m3 in surface/subsurface appurtenances (e.g., vents, valve pits, pump vaults, etc.). Historically, the system was used to transport liquid low level and process waste between generator facilities in Melton Valley, storage and disposal sites in Melton Valley, and storage/treatment facilities in Bethel Valley. The selected remedy in the Melton Valley Record of Decision (ROD) for inactive pipelines was isolation, removal, or stabilization. Pipeline remediation activities began in the summer of 2005 and were completed in the spring of 2006. The task entailed an iterative process of selecting pipeline access points, excavating and exposing pipelines, performing tapping, draining and cutting activities, either installing fittings for grouting or plugging and capping the lines. Grouting was accomplished using paired access points, with one location serving as the grout injection point and the other as vent/drain and grout confirmation point. Grouting was conducted by pumping a cement-bentonite grout into the specially installed fittings and typically proceeded from a low point to a high point to ensure complete filling of the pipeline (i.e., no void space). The project successfully grouted a total of 8,454 meters (linear distance) of pipeline; another 3,573 meters of pipeline was stabilized through isolation. (authors)

  11. Real-time in situ measurements of trace gases from agriculturally cultivated soils by means of laser spectroscopic techniques

    OpenAIRE

    Hillebrand, Malte

    2008-01-01

    Two devices to study the exchange of climate relevant trace gases between arable cultivated soils and the atmosphere in the North China Plain are presented in this thesis. They are based on Tunable Diode Laser Photoacoustic Spectroscopy (TDL-PAS). These devices are capable of real-time in situ detection of trace gases. For methane a detection limit of 85 ppb and for ammonia of 111 ppb was achieved, respectively. For the field campaign at the experimental field Dongbeiwang (DBW) in Beijing it ...

  12. Maintaining stability of standalone Micro-Grid by employing electrical and mechanical fault ride through techniques upon fixed speed wind generation systems

    International Nuclear Information System (INIS)

    Highlights: • This paper presented two fault ride through techniques for fixed speed wind systems. • The first technique is implemented by inserting a series resistance with the terminals of wind generator. • Second technique is performed by adapting the gear ratio to spill some mechanical power. - Abstract: This study presents two different Fault Ride Through (FRT) techniques to keep and restore stability of Fixed Speed Wind Generation system (FSWGs) installed in standalone Micro-Grid (MG). The first technique is an electrical FRT and is implemented by inserting a series resistance with the terminals of FSWGs during fault to maintain reasonable value of terminal voltage and consequently help stability restoration. The second controller is a mechanical FRT controller and is performed by change the gear ratio of wind generation systems to spill part of extracted mechanical power and consequently improving stability issue. Obtained results proved that each controller able to maintain the stability of FSWGs under the most severe disturbance conditions (400 ms three phase fault at FSWGs terminals). The first controller is faster than the second controller in restoring FSWGs stability. Superior results and performances are obtained when the two FRT techniques are employed simultaneously. Without employing any one of the two FRT techniques, FSWGs is not able to maintain or restore its stability after fault clearing. Consequently, MG will lose one of its micro-sources and cannot keep its stability during the standalone mode, unless load shedding strategy is activated. The two proposed controllers are simple, effective, and economical attractive

  13. New technique for in-situ measurement of backscattered and secondary electron yields for the calculation of signal-to-noise ratio in a SEM.

    Science.gov (United States)

    Sim, K S; White, J D

    2005-03-01

    The quality of an image generated by a scanning electron microscope is dependent on secondary emission, which is a strong function of surface condition. Thus, empirical formulae and available databases are unable to take into account actual metrology conditions. This paper introduces a simple and reliable measurement technique to measure secondary electron yield (delta) and backscattered electron yield (eta) that is suitable for in-situ measurements on a specimen immediately prior to imaging. The reliability of this technique is validated on a number of homogenous surfaces. The measured electron yields are shown to be within the range of published data and the calculated signal-to-noise ratio compares favourably with that estimated from the image. PMID:15725127

  14. Miniature specimen technique as in-situ methodology for determination of mechanical properties of operating pressure vessels

    International Nuclear Information System (INIS)

    The materials of operating pressure vessels are subjected to changes in their mechanical properties. The degree of these changes may depend upon the material and working environment including operating conditions. In-situ property measurement of these materials would be useful as it gives the actual status of the material, which would be useful for life assessment and to take appropriate action to prevent any failure. Reactor Engineering Division has developed a surface sampling device, known as 'sampling module', which can obtain in-situ samples from the surface of the pressure vessel in non-destructive manner. The device works on internal grinding principle and removes a small sample of 25 mm x 50 mm size, which is elliptical in shape. This sample is used for preparation of miniature specimen for various tests, like tensile test and fatigue test etc. This paper highlights development of sampling module, retrieval of sample from the pressure vessel, size and shape of various miniature specimens, layout of miniature specimens in sample, preparation of specimens, testing procedures and co-relationship with conventional tests. (author)

  15. In situ determination of the hydrothermal properties of a deep fractured medium by a single-well technique

    Science.gov (United States)

    Hosanski, J. M.; Ledoux, E.

    1982-03-01

    The recovery of energy from deep hot rock formations with low permeability gives rise to many scientific and technological problems. This paper describes a simple method of in situ analysis of a slightly fissured medium, developed by the Centre d'Informatique Géologique of the Paris School of Mines, during experiments carried out at the site of Mayet de Montagne (Allier, France) between November 1978 and March 1980. These experiments were funded by the Commission of the European Communities and the Institut National d'Astronomie et de Géophysique, and carried out jointly with the Institut de Physique du Globe, Paris. They had a two-fold purpose: (1) Better understanding of the physical phenomena governing the heat exchange between the slightly fissured medium and the injected fluids. (2) Determination in situ of the parameters which control this exchange. This proposed "single-well" method might be suitable as a preliminary test in order to evaluate the life span of a hot dry rock geothermal doublet.

  16. In-situ measurement of the effect of LiOH on the stability of fuel cladding oxide film in simulated PWR primary water environment

    International Nuclear Information System (INIS)

    The trends towards higher burnups, increasing lithium concentration and higher coolant temperature in the pressurized water reactors (PWR) impose a demand for better fuel cladding corrosion and hydriding properties. Development of new improved cladding materials is a long process. There is also a lack of reliable and fast in-situ techniques to investigate zirconium alloys in high temperature water environments. This paper describes the results of the Contact Electric Resistance (CER) technique which was used to measure the electric resistances of the oxides growing on zirconium based fuel cladding materials. Different types of zirconium alloys were studied in simulated PWR water. It was found that LiOH decreases the electric resistance of the oxides when LiOH is in excess of about 70 ppm in PWR water at 300 C. The electric resistance of the oxides is dependent on LiOH concentration and is shown to correlate inversely with the effect of LiOH on the weight gain. The kinetics of the decrease of the electric resistance indicate that the mechanism of degradation is a phase transformation rather than a diffusion limited process. The increase of the electric resistance of the oxide in the early stage of oxide formation is shown to correlate well with the in-reactor performance of similar alloys. The results of the in-situ monitoring of the electric resistances of the oxides give the same ranking for the corrosion resistances as the long term in-reactor weight gain tests of the similar alloys. The major benefit is that the results of the CER-measurements can be generated within a fraction of the testing time needed for weight gain tests

  17. In Situ Studies of Fe4+ Stability in ?-Li3Fe2(PO4)3 Cathodes for Li Ion Batteries

    DEFF Research Database (Denmark)

    Christiansen, Ane Sælland; Johnsen, Rune E.; Norby, Poul; Frandsen, Cathrine; Mørup, Steen; Jensen, Søren Højgaard; Kammer Hansen, Kent; Holtappels, Peter

    2015-01-01

    In commercial Fe-based batteries the Fe2+/Fe3+ oxidation states are used, however by also utilizing the Fe4+ oxidation state, intercalation of up to two Li ions per Fe ion could be possible. In this study, we investigate whether Fe4+ can be formed and stabilized in ?-Li3Fe2(PO4)3. The work includes in situ synchrotron X-ray powder diffraction studies (XRPD) during charging of ?-Li3Fe2(PO4)3 up to 5.0 V vs. Li/Li+. A novel capillary-based micro battery cell for in situ XRPD has been designed for ...

  18. In situ microbial filter used for bioremediation

    Science.gov (United States)

    Carman, M. Leslie (San Ramon, CA); Taylor, Robert T. (Roseville, CA)

    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.

  19. Combined Characterization Techniques to Understand the Stability of a Variety of Organic Photovoltaic Devices - the ISOS-3 inter- laboratory collaboration

    DEFF Research Database (Denmark)

    Lira-Cantu, Monica; Tanenbaum, David M.

    2012-01-01

    This work is part of the inter-laboratory collaboration to study the stability of seven distinct sets of state-of-the-art organic photovoltaic (OPVs) devices prepared by leading research laboratories. All devices have been shipped to and degraded at the Danish Technical University (DTU, formerly RISO-DTU) up to 1830 hours in accordance with established ISOS-3 protocols under defined illumination conditions. In this work we present a summary of the degradation response observed for the NREL sample, an inverted OPV of the type ITO/ZnO/P3HT:PCBM/PEDOT:PSS/Ag/Al, under full sun stability test. The results reported from the combination of the different characterization techniques results in a proposed degradation mechanism. The final conclusion is that the failure of the photovoltaic response of the device with time under full sun solar simulation, is mainly due to the degradation of the electrodes and not to the active materials of the solar cell.

  20. High sensitive diagnostic technique for virus gene using radioisotope. Development of PCR in situ hybridization and its application

    International Nuclear Information System (INIS)

    In order to elucidate how in vivo localization on traced amount of virus present in a texture progressed in a cancer process, this study aimed to conduct technical development to clarify quantitative and qualitative differences of virus genome, and man gene at each cell unit. In 1997 fiscal year, in order to make analysis on each cell secure according to microdissection established in last fiscal year, analysis on base alignment of gene held by each cell was conducted, and establishment of a method to clarify its diversity was examined. As a result, it was found that a genetic information was held in each cell, of which information could be distinguished in a range. And, it could be established that analysis using PCR in situ hybridization method could not give any advancement changeable with conventional method as well, but that analysis using microdissection method could pay this price. (G.K.)

  1. Facile in situ characterization of gold nanoparticles on electrode surfaces by electrochemical techniques: average size, number density and morphology determination.

    Science.gov (United States)

    Wang, Ying; Laborda, Eduardo; Salter, Chris; Crossley, Alison; Compton, Richard G

    2012-10-21

    A fast and cheap in situ approach is presented for the characterization of gold nanoparticles from electrochemical experiments. The average size and number of nanoparticles deposited on a glassy carbon electrode are determined from the values of the total surface area and amount of gold obtained by lead underpotential deposition and by stripping of gold in hydrochloric acid solution, respectively. The morphology of the nanoparticle surface can also be analyzed from the "fingerprint" in lead deposition/stripping experiments. The method is tested through the study of gold nanoparticles deposited on a glassy carbon substrate by seed-mediated growth method which enables an easy control of the nanoparticle size. The procedure is also applied to the characterization of supplied gold nanoparticles. The results are in satisfactory agreement with those obtained via scanning electron microscopy. PMID:22946092

  2. In situ depositing silver nanoclusters on silk fibroin fibers supports by a novel biotemplate redox technique at room temperature.

    Science.gov (United States)

    Dong, Qun; Su, Huilan; Zhang, Di

    2005-09-22

    Evolvement of bioinspired approaches for the construction of well-ordered nanostructures is a crucial intersection of branches of materials science and biotechnology. In this paper, floriated clusters of silver nanocrystallites, which consist of polycrystalline grains about 5 nm in diameter, have been successfully prepared on silk fibroin fibers (SFFs) through an in situ biotemplate redox approach at room temperature. The reductive amino acid tyrosine of SFFs mainly provided both reduction and location functions under alkaline conditions and could reduce Ag(I) ions to Ag(0). Finally, stable silver nanoclusters were generated on SFF substrates. The morphologies of silver nanoclusters were mostly attributed to the concentration of silver nitrate solution as well as special configurations and structures of silk fibroin macromolecules. A possible mechanism was explored intensively for tyrosine-residue-based silver nanocrystal formation. PMID:16853228

  3. Fluorescence in situ hybridization techniques (FISH) to detect changes in CYP19a gene expression of Japanese medaka (Oryzias latipes)

    International Nuclear Information System (INIS)

    The aim of this study was to develop a sensitive in situ hybridization methodology using fluorescence-labeled riboprobes (FISH) that allows for the evaluation of gene expression profiles simultaneously in multiple target tissues of whole fish sections of Japanese medaka (Oryzias latipes). To date FISH methods have been limited in their application due to autofluorescence of tissues, fixatives or other components of the hybridization procedure. An optimized FISH method, based on confocal fluorescence microscopy was developed to reduce the autofluorescence signal. Because of its tissue- and gender-specific expression and relevance in studies of endocrine disruption, gonadal aromatase (CYP19a) was used as a model gene. The in situ hybridization (ISH) system was validated in a test exposure with the aromatase inhibitor fadrozole. The optimized FISH method revealed tissue-specific expression of the CYP19a gene. Furthermore, the assay could differentiate the abundance of CYP19a mRNA among cell types. Expression of CYP19a was primarily associated with early stage oocytes, and expression gradually decreased with increasing maturation. No expression of CYP19a mRNA was observed in other tissues such as brain, liver, or testes. Fadrozole (100 ?g/L) caused up-regulation of CYP19a expression, a trend that was confirmed by RT-PCR analysis on excised tissues. In a combination approach with gonad histology, it could be shown that the increase in CYP19a expression as measured by RT-PCR on a whole tissue basis was due to a combination of both increases in numbers of CYP19a-containing cells and an increase in the amount of CYP19a mRNA present in the cells

  4. Susceptibility to Coffee Staining during Enamel Remineralization Following the In-Office Bleaching Technique : An In Situ Assessment

    DEFF Research Database (Denmark)

    Mori, Aline Akemi; Lima, Fernanda Ferruzzi

    2015-01-01

    PURPOSE: To assess in situ the enamel mineralization level and susceptibility to coffee staining after in-office bleaching. MATERIALS AND METHODS: Thirty-six human dental fragments assembled into intraoral devices were bleached with 35% hydrogen peroxide and treated as follows: (group 1) no contact with coffee; (group 2) immersion in a coffee solution for 30 minutes daily for 7 days, starting 1 week after bleaching; and (group 3) immersion in a coffee solution for 30 minutes daily for 14 days, starting immediately after bleaching. Enamel mineralization and color were assessed before bleaching (T1), immediately after bleaching (T2), and after 7 (T3) and 14 days (T4). The CIE whiteness index (W*) and closeness to white (?W*) following bleaching and/or immersion in coffee were calculated. Data were analyzed with Friedman and Wilcoxon tests or Kruskal-Wallis and Mann-Whitney U-tests (??=?0.05). RESULTS: Significant differences in the mineralization levels were observed as a function of time. No significant differences in W* were observed between groups, nor was W* significantly different at T3 and T4. Similar ?W* was observed between groups after 7 or 14 days. CONCLUSIONS: The mineral loss after in-office bleaching was progressively reversed by contact with saliva for 14 days. The whiteness index was not affected by contact with coffee during the remineralization period. CLINICAL SIGNIFICANCE: The results of this in situ study suggest that the mineral loss caused by in-office dental bleaching is minimal and is partly compensated by remineralization due to contact with saliva. Additionally, whiteness was not affected by daily exposition to coffee during the enamel remineralization, which indicates that avoiding the consumption of coffee immediately following in-office bleaching is unnecessary.

  5. Application of stabilization techniques in the dynamic analysis of multibody systems

    Directory of Open Access Journals (Sweden)

    Hajžman M.

    2007-11-01

    Full Text Available This paper is intended to the discussion of possible methods for the solution of the motion equations of constrained multibody systems. They can be formulated in the form of differential-algebraic equations and their numerical solution brings the problems of constraint violation and numerical stability. Therefore special methods were proposed to handle these problems. Various approaches for the numerical solution of equations are briefly reviewed and the application of the Baumgarte’s stabilization method on testing examples is shown. The paper was motivated by the effort to find the suitable solution methods for the equations of motion in the form of differentialalgebraic equations using the MATLAB standard computational system.

  6. Design of a Stability Augmentation System for an Unmanned Helicopter Based on Adaptive Control Techniques

    Directory of Open Access Journals (Sweden)

    Shouzhao Sheng

    2015-09-01

    Full Text Available The task of control of unmanned helicopters is rather complicated in the presence of parametric uncertainties and measurement noises. This paper presents an adaptive model feedback control algorithm for an unmanned helicopter stability augmentation system. The proposed algorithm can achieve a guaranteed model reference tracking performance and speed up the convergence rates of adjustable parameters, even when the plant parameters vary rapidly. Moreover, the model feedback strategy in the algorithm further contributes to the improvement in the control quality of the stability augmentation system in the case of low signal to noise ratios, mainly because the model feedback path is noise free. The effectiveness and superiority of the proposed algorithm are demonstrated through a series of tests.

  7. Application of stabilization techniques in the dynamic analysis of multibody systems

    OpenAIRE

    Hajžman M.; Polach P.

    2007-01-01

    This paper is intended to the discussion of possible methods for the solution of the motion equations of constrained multibody systems. They can be formulated in the form of differential-algebraic equations and their numerical solution brings the problems of constraint violation and numerical stability. Therefore special methods were proposed to handle these problems. Various approaches for the numerical solution of equations are briefly reviewed and the application of the Baumgarte’s stabili...

  8. Simulation Techniques of Electrical Power System Stability Studies Utilizing Matlab/Simulink

    OpenAIRE

    Naresh K. Tanwani*1

    2014-01-01

    Maintaining synchronism between different parts of power system (PS) is getting difficult over time. The fact that growth of interconnected system is a continuous process, also these systems have been extended in different regions. In this research work steady state (SS) and transient stabilities along with swing equation and numerical solution using MATLAB / Simulink are studied. This work is done in two steps. In the first step, proper assumptions are made to linearize the s...

  9. Control-oriented modelling for neoclassical tearing mode stabilization via minimum-seeking techniques

    Science.gov (United States)

    Wehner, W.; Schuster, E.

    2012-07-01

    Suppression of magnetic islands driven by the neoclassical tearing mode (NTM) is necessary for efficient and sustained operation of tokamak fusion reactors. Compensating for the lack of bootstrap current, due to the pressure profile flattening in the magnetic island, by a localized electron cyclotron current drive (ECCD) has been proved experimentally as an effective method to stabilize NTMs. The effectiveness of this method is limited in practice by the uncertainties in the width of the island, the relative position between the island and the beam, and the ECCD power threshold for NTM stabilization. Heuristic search and suppress algorithms have been proposed and shown effective in improving the alignment of the ECCD beam with the island, using only an estimate of the island width. Making use of this estimate, real-time, non-model-based, extremum-seeking optimization algorithms have also been proposed not only for beam steering but also for power modulation in order to minimize the island-beam misalignment and the time required for NTM stabilization. A control-oriented dynamic model for the effect of ECCD on the magnetic island is proposed in this work to enable both control design and performance analysis of these minimum-seeking type of controllers. The model expands previous work by including the impact of beam modulation parameters such as the island-beam phase mismatch and the beam duty-cycle on the island width dynamics.

  10. Control-oriented modelling for neoclassical tearing mode stabilization via minimum-seeking techniques

    International Nuclear Information System (INIS)

    Suppression of magnetic islands driven by the neoclassical tearing mode (NTM) is necessary for efficient and sustained operation of tokamak fusion reactors. Compensating for the lack of bootstrap current, due to the pressure profile flattening in the magnetic island, by a localized electron cyclotron current drive (ECCD) has been proved experimentally as an effective method to stabilize NTMs. The effectiveness of this method is limited in practice by the uncertainties in the width of the island, the relative position between the island and the beam, and the ECCD power threshold for NTM stabilization. Heuristic search and suppress algorithms have been proposed and shown effective in improving the alignment of the ECCD beam with the island, using only an estimate of the island width. Making use of this estimate, real-time, non-model-based, extremum-seeking optimization algorithms have also been proposed not only for beam steering but also for power modulation in order to minimize the island-beam misalignment and the time required for NTM stabilization. A control-oriented dynamic model for the effect of ECCD on the magnetic island is proposed in this work to enable both control design and performance analysis of these minimum-seeking type of controllers. The model expands previous work by including the impact of beam modulation parameters such as the island-beam phase mismatch and the beam duty-cycle on the island width dynamics. (paper)

  11. Characteristics of LiCl salt wastes conditioned by the gel-route stabilization technique

    International Nuclear Information System (INIS)

    A new concept for the stabilization and solidification of metal chloride salt wastes generated from the Advanced Spent Fuel Conditioning Process (ACP) of KAERI via gelation in a simple material system is introduced in this paper. Using sodium silicate as a reaction module and phosphoric acid as a catalyst or stabilization agent, CsCl is chemically converted to thermally stable compounds. The reaction route was as follows. [G] + Na+(aq) + M+(aq) + Cl-(aq) ? [G,M] + NaCl(s); [G] + H+(aq) + M+(aq) + Cl-(aq) ? [G,M] + HCl(g), where [G] is the network of a gel active with the metal cations. The heat-treated product at 1000.deg.C contained a cristobalite crystalline framework and a glassy phosphorus-rich phase with a high Cs content. The morphology looked like honey flowing on the honeycomb. From the TG/DT analysis, Cs could not be vaporized below 1300.deg.C by changing the aging conditions and molar ratio of Si/P. As a new concept, GRSS (gel-route stabilization and solidification) could provide us with the chance to make the high temperature waste conditioning process more stable and economical

  12. Thiocholine mediated stabilization of in situ produced CdS quantum dots: application for the detection of acetylcholinesterase activity and inhibitors.

    Science.gov (United States)

    Garai-Ibabe, Gaizka; Saa, Laura; Pavlov, Valeri

    2014-01-01

    The use of acetylcholinesterase (AChE) inhibitors as chemical warfare agents or pesticides represents a strong hazard against human health. The high toxicity of these compounds arises from their ability to inhibit acetylcholinesterase from degrading acetylcholine (ACh), which could affect the physiology of the nervous system with serious or fatal consequences. Here we report a simple and fluorimetric system for a highly sensitive detection of AChE activity and inhibitors. The principle of this approach is based on the hydrolysis of acetylthiocholine (ATCh) by AChE, which yields the thiol-bearing compound thiocholine (TCh) that at trace concentrations stabilized the in situ generated CdS quantum dots (QDs). The system shows a linear relationship between the fluorescence intensity and AChE activity from 1 to 10 mU mL(-1) in buffer solution. The accuracy of the proposed system was further demonstrated through the determination of AChE activity in human serum (HS) by the standard addition method. Furthermore, this novel and highly sensitive sensing system allows the detection of 80 pM of the AChE inhibitor paraoxon and 100 nM of galanthamine. The reported methodology shows potential applications for the development of a simple and inexpensive assay for the routine quantification of AChE activity and inhibitors. PMID:24225492

  13. Structural stability and self-healing capability of Er2O3 in situ coating on V-4Cr-4Ti in liquid lithium

    International Nuclear Information System (INIS)

    The in situ Er2O3 insulating coating is under development for the self-cooled Li/V-alloy type fusion blanket. In this study, the structural stability and self-healing capability of the coating are investigated. Since the cracking in the coating was not observed after exposure when Li was removed with a weak lotion (liquid NH3), the cracking observed in the previous studies is not a practical issue in a real blanket. The re-exposure of the coating in pure Li showed that the coating once formed in Li (Er) is thought to be stable in pure Li. Thus, coating has the possibility to be serviced in a Li environment without an Er supply. By prior exposure to Li (Er) at 873 K, the exhaustion of the oxygen storage in V-alloy substrate during exposure at 973 K could be delayed effectively. The self-healing capability of the coating was demonstrated by the examination with the re-exposing cracked coating in Li (Er)

  14. In situ and real-time atomic force microscopy studies of the stability of oligothiophene langmuir-blodgett monolayers in liquid

    KAUST Repository

    Yin, Naining

    2014-03-20

    Oligothiophene thin films have been considered as promising material for molecular electronics due to their desirable electronic properties and high structural stability under ambient conditions. To ensure performance in devices the functional structures, such as individual ordered domains, must be stable under practical and operational conditions or environments including exposure to various media. This work investigates the structure of oligothiophene Langmuir-Blodgett (LB) films upon exposure to liquid media such as water, ethanol (EtOH), and mixed tetrahydrofuran (THF)/EtOH solutions. The LB films form islands ranging from 500 nm up to 1 ?m consisting of densely packed oligothiophene molecules. These islands are surrounded by bare substrate and loosely packed adsorbates. In situ and time-dependent AFM images were acquired to reveal the structural evolution, from which degradation pathways and kinetics are extracted. Degradation of these LB films initiates and propagates from intraisland defect sites, such as cracks and pin holes, whereas the edges of islands remain intact on the surface. The observations appear to be in contrast to the known degradation mechanism among self-assembled monolayers, such as alkanethiols on gold, which initiates and progresses at domain boundaries. Rationale for the observed degradation processes will also be discussed. © 2014 American Chemical Society.

  15. A transposed frequency technique for phase noise and frequency stability measurements

    OpenAIRE

    Hartnett, John G.; Povey, Travis; Parker, Stephen,; Ivanov, Eugene

    2012-01-01

    The digital signal processing has greatly simplified the process of phase noise measurements, especially in oscillators, but its applications are largely confined to the frequencies below 400 MHz. We propose a novel transpose frequency technique, which extends the frequency range of digital noise measurements to the microwave domain and beyond. We discuss two basic variations of the proposed noise measurement technique, one of which enables characterization of phase fluctuat...

  16. Mimicked in-situ stabilization of metals in a cropped soil: Bioavailability and chemical form of zinc

    Energy Technology Data Exchange (ETDEWEB)

    Chlopecka, A.; Adriano, D.C. [Univ. of Georgia, Aiken, SC (United States)

    1996-11-01

    Agricultural lime, natural zeolite (clinoptilolite), hydroxyapatite, and an iron oxide waste byproduct (Fe-rich, a trademark name of E.I. du Pont de Nemours) were added to an artificially contaminated Applying silt loam soil to stabilize and limit the uptake of Zn by crops. A greenhouse pot study involves spiking the soil with flue dust FD at 0, 150, 300, 600, 1200, and 2400 mg of Zn kg{sup -1}. As much as 40% of the total Zn occurred in an exchangeable form, the form considered most bioavailable to plants, when the pH of the FD-spiked soil was below 6.0. The ameliorants (lime, zeolite, apatite, and Fe-rich) decreased the concentration of the exchangeable form of Zn at each level of FD in soil; however, the largest decrease occurred with the lowest dose. Maize (Zea mays), barley (Hordeum vulgare), and radish (Raphanus sativus) were growth to determine the effects of Zn on the plant growth and its uptake. The addition of ameliorants to soil enhanced the growth and yield of maize and barley, but only Fe-rich enhanced the growth of radish at all FD rates. Lime, zeolite, and apatite significantly reduced the Zn concentration in tissues of the 3-week-old maize, in mature maize tissues (roots, young leaves, old leaves, stems, grain), and in barley. The largest reduction (over 80%) in Zn uptake by all crops was effected by Fe-rich, which is consistent with the greatest reduction in soil-exchangeable Zn by this ameliorant. 44 refs., 4 figs., 7 tabs.

  17. Assessment of microbial methane oxidation above a petroleum-contaminated aquifer using a combination of in situ techniques

    Science.gov (United States)

    Urmann, Karina; Schroth, Martin H.; Noll, Matthias; Gonzalez-Gil, Graciela; Zeyer, Josef

    2008-06-01

    Emissions of the greenhouse gas CH4, which is often produced in contaminated aquifers, are reduced or eliminated by microbial CH4 oxidation in the overlying vadose zone. The aim of this field study was to estimate kinetic parameters and isotope fractionation factors for CH4 oxidation in situ in the vadose zone above a methanogenic aquifer in Studen, Switzerland, and to characterize the involved methanotrophic communities. To quantify kinetic parameters, several field tests, so-called gas push-pull tests (GPPTs), with CH4 injection concentrations ranging from 17 to 80 mL L-1 were performed. An apparent Vmax of 0.70 ± 0.15 mmol CH4 (L soil air)-1 h-1 and an apparent Km of 0.28 ± 0.09 mmol CH4 (L soil air)-1 was estimated for CH4 oxidation at 2.7 m depth, close to the groundwater table. At 1.1 m depth, Km (0.13 ± 0.02 mmol CH4 (L soil air)-1) was in a similar range, but Vmax (0.076 ± 0.006 mmol CH4 (L soil air)-1 h-1) was an order of magnitude lower. At 2.7 m, apparent first-order rate constants determined from a CH4 gas profile (1.9 h-1) and from a single GPPT (2.0 ± 0.03 h-1) were in good agreement. Above the groundwater table, a Vmax much higher than the in situ CH4 oxidation rate prior to GPPTs indicated a high buffer capacity for CH4. At both depths, known methanotrophic species affiliated with Methylosarcina and Methylocystis were detected by cloning and sequencing. Apparent stable carbon isotope fractionation factors ? for CH4 oxidation determined during GPPTs ranged from 1.006 to 1.032. Variability was likely due to differences in methanotrophic activity and CH4 availability leading to different degrees of mass transfer limitation. This complicates the use of stable isotopes as an independent quantification method.

  18. Technique for numerical analysis of stability and self-oscillations in boiling water cooled reactors

    International Nuclear Information System (INIS)

    Methods for investigating the boiling water cooled reactor dynamics, which consist in finding the boundary of neutron-physical and thermohydraulic process stability region and calculating the oscillation amplitudes occuring when moving inside the instability region, are proposed. The methods are based on the computerized calculation of transients for the quasistaical change of the parameter, determining the steady-state regime, which is performed according to the reactor nonlinear mathematical model. A boiling water cooled reactor with low coolant underheating up to the saturation temperature at the inlet to the reactor core is considered as an example. Bifurcation diagrams are plotted for different values of the reactor physical and design parameters

  19. Simple technique to measure toric intraocular lens alignment and stability using a smartphone.

    Science.gov (United States)

    Teichman, Joshua C; Baig, Kashif; Ahmed, Iqbal Ike K

    2014-12-01

    Toric intraocular lenses (IOLs) are commonly implanted to correct corneal astigmatism at the time of cataract surgery. Their use requires preoperative calculation of the axis of implantation and postoperative measurement to determine whether the IOL has been implanted with the proper orientation. Moreover, toric IOL alignment stability over time is important for the patient and for the longitudinal evaluation of toric IOLs. We present a simple, inexpensive, and precise method to measure the toric IOL axis using a camera-enabled cellular phone (iPhone 5S) and computer software (ImageJ). PMID:25316617

  20. THE EFFICACY OF REINFORCEMENT TECHNIQUE ON THE FLY ASH STABILIZED EXPANSIVE SOIL AS A SUBGRADE EMBANKMENT FOR HIGHWAYS

    Directory of Open Access Journals (Sweden)

    KOTESWARA RAO.D

    2011-02-01

    Full Text Available The most significant factor that influencing the design thickness of a flexible pavement overlay is rebound deformation from repeated load application and subgrade support values . It is essential to stabilize and reinforce the poor soils to bear the traffic intensity or truck loading. Different types of materials are provided with stabilization techniques to achieve suitable performance and to reduce maintenance costs and also to provide required service life for the subgrade embankments. In the present study, the effect of geo-textile as a reinforcement in the sub grade embankment is verified by conducting cyclic plate load tests. Locally available soil is mixed with optimum of fly ash and then this mixer is stabilized with optimum of CaCl2 for the construction of sub grade embankment with and with out reinforcement. Compaction properties and C.B.R values are determined for the locally available soil and categorized as CH soil as per IS classification, fly ash, fly ash - CaCl2 mix with the CH soil. The introduction of geo-textile has been reduced the deformation and increased the load carrying capacity as was revealed by cyclic plate load tests.

  1. Equations of State of Selected Armor Ceramics by In-situ High-Pressure X-ray and Ultrasonic Techniques: Comparison with Shock Wave Data

    Science.gov (United States)

    Manghnani, Murli; Amulele, George; Hushur, Anwar

    2007-06-01

    Ultrasonic measurements of the sound velocity and elastic moduli, and their pressure derivatives for well prepared armor ceramics can provide accurate constraints for establishing their equations of state. Using in-situ high-pressure synchrotron X-ray diffraction and diamond anvil cell techniques at the Advanced Photon Source, we have investigated the compression behavior (V/Vo vs P) for ?- and ?-SiC, TiB2, B4C, WC and WC-6%Co to 65 GPa. Ultrasonic measurements of Ko and Ko' made to ˜15 GPa show excellent agreement with X-ray results. Together, these results are compared with published shock wave data in terms of Us-Up slope, Ko', compression behavior, elastic anisotropy, and material strength. No phase transition is found in these materials, except for B4C, in which case some structural distortion is indicated.

  2. Innovative Protocols for in SITU MTBE Degradation by Using Molecular Probes-An Enhanced Chemical-Bio Oxidation Technique

    Energy Technology Data Exchange (ETDEWEB)

    Paul Fallgren

    2009-02-20

    In situ chemical oxidation (ISCO) is a common technology to cleanup petroleum hydrocarbon-contaminated soils and groundwater. Sodium percarbonate (SPC) is an oxidant which is activated by iron (Fe) to produce Fenton-like reactions. Western Research Institute, in conjunction with Regenesis and the U.S. Department of Energy, conducted a study that investigated the performance of a 'safe' oxidant, SPC, to cleanup groundwater and soils contaminated with petroleum hydrocarbons and associated contaminants (e.g., MTBE). Results from a field pilot test in Frenchglen, Oregon showed VOC concentrations in groundwater decreased substantially within 2 weeks after injecting activated SPC (RegenOx). A protocol was established for determining RegenOx TOD in soils and groundwater. Total oxidant demand tests were necessary to determine the correct dosage of RegenOx to apply in the field and sufficiently degrade the contaminants of concern. Bench studies with RegenOx showed this technology was effective in degrading diesel fuel and 1,4-dioxane. The Fe-silica activator (RegenOx Part B) was tested with another oxidant, sodium persulfate. Bench tests results showed the combination of sodium persulfate and RegenOx Part B was effective in reducing PCE, MTBE, benzene, and n-heptane concentrations in water. Overall, the results of this project indicated that most petroleum contaminants in soil and groundwater can be sufficiently degraded using the RegenOx technology.

  3. The karyotype of Festucopsis serpentini (Poaceae Triticeae) from Albania studied by banding techniques and in situ hybridization

    DEFF Research Database (Denmark)

    Linde-Laursen, I.; Seberg, O.

    1996-01-01

    The karyotypes of two populations of Festucopsis serpentini (2n = 2x = 14) endemic to Albania were investigated in detail by Giemsa C- and N-banding, AgNO3 staining, and in situ hybridization with an rDNA probe. The complements consisted of 14 large chromosomes, 10 metacentric and 4 SAT-chromosomes, a metacentric and a submetacentric pair. SAT-chromosomes from one population carried exclusively minute satellites, whereas SAT-chromosomes from another population also carried larger polymorphic satellites, suggesting a geographical differentiation. The existence of four chromosomes with nucleolus forming activity was established through AgNO3 staining; however, the rDNA probe additionally hybridized to intercalary positions in the short arms of two metacentric chromosomes revealing two inactive rDNA sites. C-banding patterns comprised from zero and up to four very small to larger, generally telomeric bands per chromosome giving low levels of constitutive heterochromatin. Similarities in chromosome morphology andC-banding patterns identified the homologous relationships of all chromosomes in one population, but of three pairs only in the other. Reliable identification of homologous chromosomes between plants was only possible for the SAT-chromosomes. A comparison between the C-banded karyotypes of F. serpentini and Peridictyon sanctum supports their position in two genera.

  4. Development of Non Destructive Evaluation Techniques for the In-Situ Inspection of the Orbiter's Thermal Protection System

    Science.gov (United States)

    Hernandez, Jose M.

    2004-01-01

    One of the Columbia Accident Investigation Board's (CAB) recommendation is to develop and implement an inspection plan to determine the structural integrity of all Reinforced Carbon-Carbon (RCC) system components that make part of the Space Shuttle's thermal protection system. This presentation focuses on the efforts to leverage non-destructive evaluation (NDE) expertise from academia, private industry, and government agencies resulting in the design of a comprehensive health monitoring program for RCC components. The different NDE techniques that were considered are presented along with the chosen techniques and preliminary inspection results of RCC materials.

  5. Microwave technique applied to the hydrothermal synthesis and sintering of calcia stabilized zirconia nanoparticles

    International Nuclear Information System (INIS)

    This study is focused on the synthesis of zirconia nanopowders stabilized by 6%mol calcia prepared under hydrothermal conditions using microwave technology. Sodium hydroxide-based hydrolysis of zirconyl chloride solution containing calcium nitrate followed by microwave irradiation at the temperature of 220 oC for 30 min was sufficient to obtain white powders of crystalline calcia stabilized zirconia. By means of X-ray diffraction and transmission electron microscopy, it was shown that tetragonal zirconia nanocrystallites with a size of ca 7 nm and diameter/standard deviation ratio of 0.10 were formed. The effects of the [Ca2+] and [NaOH] as well as temperature and time of microwave irradiation on the density and specific surface area were evaluated. Sintering test of the tetragonal nanopowders at 1,300 oC in air was performed in a monomode microwave applicator. The sample was sintered to the density of 95% and the grain size, analyzed by field emission scanning electron microscopy, was in the range from 90 to 170 nm.

  6. Sublimation extraction coupled with gas chromatography-mass spectrometry: A new technique for future in situ analyses of purines and pyrimidines on Mars

    Science.gov (United States)

    Glavin, D. P.; Cleaves, H. J.; Buch, A.; Schubert, M.; Aubrey, A.; Bada, J. L.; Mahaffy, P. R.

    2006-12-01

    We have developed a sublimation technique coupled with chemical derivatization and gas chromatography mass spectrometry (GC-MS) to detect nucleobases and other volatile organic compounds derived from bacteria in Mars analog materials. To demonstrate this technique, a sample of serpentine inoculated with Escherichia coli ( E. coli) cells was heated to 500 °C for several seconds under Martian ambient pressure. The sublimate was collected on a cold finger, then derivatized and analyzed by GC-MS. We found that adenine, cytosine, thymine and uracil were the most abundant molecules detected in the sublimed E. coli extract by GC-MS. In addition, nucleobases were also detected in sublimed extracts of a deep-sea sediment sample, seawater, and soil collected from the Atacama Desert in Chile after heating the samples under the same conditions. Our results indicate that nucleobases can be easily isolated directly from natural samples using sublimation and then detected by GC-MS after chemical derivatization. The sublimation-based extraction technique is one approach that should be considered for use by future in situ instruments designed to detect organic compounds relevant to life in the Martian regolith.

  7. Predictive tools and data needs for long term performance of in-situ stabilization and containment systems: DOE/OST stabilization workshop, June 26-27, Park City, Utah

    International Nuclear Information System (INIS)

    This paper summarizes the discussion within the Predictive Tools and Data Needs for Long Term Performance Assessment Subgroup. This subgroup formed at the DOE Office of Science and Technology workshop to address long-term performance of in situ stabilization and containment systems. The workshop was held in Park City, Utah, 26 and 27 June, 1996. All projects, engineering and environmental, have built-in decision processes that involve varying risk/reward scenarios. Such decision-processes maybe awkward to describe but are utilized every day following approaches that range from intuitive to advanced mathematical and numerical. Examples are the selection of components of home sound system, the members of a sports team, investments in a portfolio, and the members of a committee. Inherent in the decision method are an understanding of the function or process of the system requiring a decision or prediction, an understanding of the criteria on which decisions are made such as cost, performance, durability and verifiability. Finally, this process requires a means to judge or predict how the objects, activities, people and processes being analyzed will perform relative to the operations and functions of the system and relative to the decision criteria posed for the problem. These risk and decision analyses are proactive and iterative throughout the life of a remediation project. Prediction inherent to the analyses are based on intuition, experience, trial and error, and system analysis often using numerical approaches

  8. In situ borehole determination of ash content of coal using gamma-gamma and neutron-gamma techniques

    International Nuclear Information System (INIS)

    During the past decade, borehole logging technology based on nuclear geophysics has found wide application in the Australian coal-mining industry. In response to the need for further improved accuracy in coal ash measurements, the Commonwealth Scientific and Industrial Research Organization, Division of Mineral Physics, has developed two new alternative techniques, which are both spectrometric. The spectrometric gamma-gamma technique is based on the existence of a simple correlation between the ash content and the equivalent atomic number and density of coal. The technique is spectrometric in that it records and uses the count rates in several windows of the backscatter spectrum. These count rates and their selected ratios describe the changes in spectral shape which are due to ash content variations. The spectrometric neutron-gamma method is suitable where the probe responses are required for specific elemental contents. Consequently, the method tolerates larger variations in ash composition for accurate measurement than does the gamma-gamma method. Both methods have been tested at several coal deposits in New South Wales and Queensland. For both techniques, RMS deviations between nuclear assay and chemical analysis are typically 2% ash in the range 5 to 40% ash. Both techniques are currently undergoing commercial development under the name of SIROLOG. The SIROLOG technology is designed to accommodate logging speeds up to 4m.min-1. However, the gamma-gamma probe uses gamma-ray sources of strength two orders of magnitude smaller than that of sources used in commercial probes. The logging system provides information on ash content in 5 cm intervals if required, although the vertical resolution of the probes is 30-35 cm. (author)

  9. Deploying a metal adsorbent in situ: a technique for indicating bioavailable Cd(II) in marine waters.

    Science.gov (United States)

    Solbrå, Susan; Allison, Nicola; Skei, Jens; Waite, Stephen; Mikhalovsky, Sergey

    2004-03-01

    This paper reports a study into the deployment of a metal adsorbent in situ to estimate bioavailable Cd(II) in marine waters. Eight adsorbents were screened in the laboratory to test their ability to accumulate Cd(II) from deionised water and artificial seawater, and an oxidised activated carbon was selected for further investigation. The adsorption isotherm at Cd(II) concentrations 0.16-38 microgl(-1) and at salinity 15 followed the Freundlich equation. The adsorbent was contained in nylon bags (pore size 35 microm) and dialysis tubes (membrane pore size 2 nm) to produce deployable devices and to investigate the effect of housing material on Cd(II) accumulation. The devices were tested in the laboratory and deployed at four field sites for up to 3 weeks. The adsorbent in the nylon bags reached equilibrium towards the end of this period and the measured contents were in good agreement with expected contents predicted from known seawater Cd(II) concentrations and the adsorption isotherm. The dialysis tubes accumulated significantly lower amounts of Cd(II) than the nylon bags, probably due to an initial lag as Cd(II) diffused into the dialysis bag and due to biofouling which reduced diffusion. The relationship between concentrations of Cd(II) accumulated by the mussels (indicating the bioavailable Cd(II) fraction) and the devices at different field sites could be described by the Freundlich model. The goodness of fit of this relationship was better for the dialysis tubes than the nylon bags. The adsorbent in the nylon bags may have collected small particles from seawater which affected the Cd(II) analysis. Both devices demonstrate potential as indicators of the relative bioavailable fraction of Cd(II) to Mytilus edulis in marine waters. PMID:15016536

  10. Karyotypes of Elymus scabrifolius (Poaceae: Triticeae) from South America studied by banding techniques and in situ hybridization.

    Science.gov (United States)

    Linde-Laursen, I B; Seberg, O

    2001-01-01

    Karyotypes of 4 accessions of Elymus scabrifolius (2n = 4x = 28) were investigated by Giemsa C- and N-banding, GAA-banding (one accession), AgNO3-staining and in situ hybridization with the rDNA probe pTa71. Two additional accessions were studied in less detail. The chromosomes were large (9-14 microns). The complements included 11 pairs of metacentrics, one with conspicuous satellites on the short arms, and 3 pairs of submetacentrics. Two of 4 accessions from Eastern Argentina and Uruguay had minute or small satellites on a submetacentric pair. No such satellites were observed in the other two accessions. In two accessions from the Cordoba province, a non-homologous submetacentric pair had very long satellites. AgNO3-staining established the presence of 4 nucleoli, two larger and two small ones, in 5 accessions. The C-banding patterns comprised from one to 12 conspicuous bands per chromosome at no preferential positions. The amount of constitutive heterochromatin (19-21%) was the highest hitherto established in the Triticeae. Similarities in banding patterns and chromosome morphology identified homologous and discriminated between non-homologous chromosomes within and, except for two chromosomes, between plants. Heteromorphic chromosome pairs were identified in satellite-carrying chromosomes only. N-banding produced conspicuous bands overall at the same positions as C-banding. GAA-banding patterns were similar to N-banding patterns. The rDNA probe hybridized to chromosome segments at nucleolar constrictions only. The production of C- and N-banding patterns in both genomes of E. scabrifolius suggests the presence of two H genomes and the absence of the pivotal St genome of Elymus. On account of the uncertain identity of one genome, and the overall similar gross morphology of E. scabrifolius and other tetraploid South American species referred to Elymus, E. scabrifolius is retained in Elymus. PMID:12035613

  11. Determination of potential groundwater discharge zones into a Salt Lake using remote sensing techniques and in-situ measurements

    Science.gov (United States)

    Kilic, Ecenur; Kamil Yilmaz, Koray; Lutfi Suzen, M.

    2015-04-01

    Groundwater and surface water are integral components of the hydrologic system with strong feedback mechanisms and hence should be treated as a single resource. Existence of groundwater discharge into lakes is a very significant factor that affects both the water quantity of the lake as well as its ecological and biological diversity. The degree of interaction is more significant for shallow lakes because of their increased vulnerability due to limited volume and rapid changes in the extent and duration of the wet/dry cycles. The Salt Lake, located in Central Anatolia, Turkey, is a hyper-saline, shallow lake that is ranked as the second largest lake in Turkey. The majority of the lake dries during the late summer season enabling investigation of the lake bottom morphology. Through analysis of the high-resolution satellite images we identified circular features that may indicate possible groundwater seepage locations. The density and shape properties of these features were then investigated via spatial statistics to identify possible trends that can be linked to controlling mechanism(s) such as underlying sediments, geology, hydrogeology and wind patterns. The analysis was supported by field measurement of salt thickness at various locations in a systematic way. Long-term precipitation, lake level and groundwater level data were compared to investigate possible relationships and trends. In this presentation the framework to investigate remotely-sensed and in-situ measurements will be discussed with potential links to the groundwater recharge to the Salt Lake. Future work will focus on installing long-term monitoring networks in the lake.

  12. Plasma spraying of an indigenous yttria stabilized zirconia powder prepared by the sol-gel technique

    International Nuclear Information System (INIS)

    An indigenous sol-gel derived yttria-partially stabilized zirconia (Y-PSZ) powder has been characterized and its suitability for plasma spraying applications evaluated. The powder, determined to have about 5.1% yttria content, predominantly consisted of spherical particles with an average equivalent particle diameter close to 25 ?m. Furthermore, it was found that the powder did not contain any particles >50?m, which is considered the ideal upper size limit for spray-grade ceramic powders in order to ensure complete melting during spraying. The sol-gel produced powder exhibited good flow characteristics and the plasma sprayed coatings developed using the powder were also found to have excellent thermal shock resistance. The corresponding results obtained using an imported Y-PSZ powder are also presented for the purpose of comparison. (author). 17 refs., 5 figs

  13. Microbial and molecular techniques to evaluate and to implement in-situ biodegradation potential and activity at sites contaminated with aromatic and chlorinated hydrocarbons

    International Nuclear Information System (INIS)

    Intrinsic bio-remediation harnesses the ability of indigenous microorganisms to degrade contaminants that are present in soil and groundwater. Over the past decade many environmental regulatory agencies especially in Europe have come to recognize the importance of these natural processes in contaminant attenuation. In order to use in-situ bio-remediation to clean up a site successfully it is necessary to investigate the indigenous microbial population and its potential activity to degrade the contaminants of concern (COCs). The evaluation of naturally-occurring degradative activity in initial screening of soil and groundwater samples using recently developed molecular and microbial methods may allow for the implementation of a contaminant reduction and management program without the need for fully engineered remediation intervention. Limited engineering approaches (nutrient delivery etc.) can be implemented to support naturally-occurring bio-restoration processes to achieve a controlled, dynamic attenuation of COCs. Techniques for monitoring pollutant-degrading microorganisms were previously limited to standard culturing techniques. More recently, techniques based upon detection of genetic elements and metabolic activities have been developed in collaboration with university partners Europe, especially in France. The modern techniques are more sensitive for monitoring microbial populations, metabolic activity and the genetic potential to degrade the COCs, and avoid the need for cultivation of microbes under artificial conditions in the laboratory. Especially the application of PCR-Tests (Polymerase Chain Reaction) are able to quantify the Genetic Potential of Pollutant Microbiological Degradation on a contaminated site. This enables to use very economic in-situ site rehabilitation strategies as for example (Dynamic Natural Attenuation). For this modern application of these new strategies PLANREAL created with HPC Envirotec and together with a French University (Biochemical Laboratory of the Medical Faculty) the first PBG-SP : 'Pole Biotechnologique et Genetique - Sites Pollues' in France. The modern tools and approaches have been applied successfully at several field sites for the evaluation, implementation and on-going monitoring of the bio-restoration/ attenuation of various aromatic and chlorinated compounds. (authors)

  14. A simplified 'sandwich' technique for in situ embedding and perpendicular sectioning of monolayer cultures of human skin fibroblasts.

    Science.gov (United States)

    Govaerts, P J; Bernaert, I I; du Caju, M V; Jacob, W A

    1987-08-01

    In the processing of cell cultures, grown as a monolayer in tissue culture dishes for electron microscopy, the sectioning of the monolayer is an essential step. The monolayer can be sectioned either parallel or perpendicular to the plane of growth. Several methods for the perpendicular way of sectioning have already been described. We propose a simplified method in which the monolayer is sandwiched between two layers of resin, one of which is a prepolymerized block, the other being a layer of resin, applied at a second stage. Sectioning of this 'flat embedded' specimen yields thin sections perpendicular to the plane of growth of the monolayer without elaborate orientating procedures. The advantage of this procedure is that it can be done using only routine embedding techniques, avoiding special materials or complex manipulations. This sandwich technique provides an excellent mechanical fixation of the monolayer and protects it against external damage. PMID:3681963

  15. Studies of MHD stability using data mining technique in helical plasmas

    International Nuclear Information System (INIS)

    Data mining techniques, which automatically extract useful knowledge from large datasets, are applied to multichannel magnetic probe signals of several helical plasmas in order to identify and classify MHD instabilities in helical plasmas. This method is useful to find new MHD instabilities as well as previously identified ones. Moreover, registering the results obtained from data mining in a database allows us to investigate the characteristics of MHD instabilities with parameter studies. We introduce the data mining technique consisted of pre-processing, clustering and visualizations using results from helical plasmas in H-1 and Heliotron J. We were successfully able to classify the MHD instabilities using the criterion of phase differences of each magnetic probe and identify them as energetic-ion-driven MHD instabilities using parameter study in Heliotron J plasmas. (author)

  16. Enhanced cycle stability of micro-sized Si/C anode material with low carbon content fabricated via spray drying and in situ carbonization

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dingsheng; Gao, Mingxia, E-mail: gaomx@zju.edu.cn; Pan, Hongge; Liu, Yongfeng; Wang, Junhua; Li, Shouquan; Ge, Hongwei

    2014-08-01

    Highlights: • Micro-sized Si/C composites were fabricated via. spray drying and carbonization. • Multi-morphology carbon was formed in the Si/C composites. • Si/C composite with 5.6 wt.% C provides significant improved cycling stability. • Multi-morphology carbon plays effective role in improving the electrochemical property. • The method provides potential for mass production of superior Si-based anode materials. - Abstract: Micro-sized Si/C composites with in situ introduced carbon of multi-morphology were fabricated via spray drying a suspension of commercial micro-sized Si and citric acid followed by a carbonization. Different ratios of Si to citric acid were used to optimize the composition and structure of the composites and thus the electrochemical performance. Carbon flakes including crooked and flat ones were well dispersed in between the Si particles, forming Si/C composites. Floc-like carbon layers and carbon fragments were also found to cover partially the Si particles. The Si/C composite with a low carbon content of 5.6 wt.% provides an initial reversible capacity of 2700 mA h/g and a capacity of 1860 mA h/g after 60 cycles at a current density of 100 mA/g as anode material for lithium-ion batteries (LIBs), which are much higher than those of pristine Si and the Si/C composites with higher carbon content. The mechanism of the enhancement of electrochemical performance of the micro-sized Si/C composite is discussed. The fabrication method and the structure design of the composites offer valuable potential in developing adaptable Si-based anode materials for industrial applications.

  17. Synthesis and characterization of a new class of stabilized apatite nanoparticles and applying the particles to in situ Pb immobilization in a fire-range soil.

    Science.gov (United States)

    Liu, Ruiqiang; Zhao, Dongye

    2013-04-01

    Phosphate compounds and the related materials are effective agents for in situ immobilization of heavy metals in contaminated soils. Problems associated with using these phosphate materials include difficulties in delivering the solid phosphate minerals to the deep contaminated zones or risks of eutrophication with applying soluble phosphates. Therefore, a new class of apatite nanoparticles was synthesized using carboxymethyl cellulose as a stabilizer in order to increase the dispersion rate of phosphate in soils but without introducing significant amount of soluble phosphate into the environment. The product was confirmed by XRD as chlorapatite (Ca5(PO4)3Cl) with poor crystallinity. TEM and SEM revealed that the particles were spherical or irregular in shape with sizes spanning from a few nm to around 200 nm. FTIR spectra suggested that Ca(II) cations formed outer-sphere bonds with carboxyl and hydroxyl groups in cellulose molecules, thus inhibiting further agglomeration of the particles. Dry combustion data supported a formula of [C6H7O2(OH)2OCH2COOCa5(PO4)3Cl]n for the nano-apatite composite. Laboratory tests showed that the nanoparticles could effectively decrease the TCLP-leachable Pb fraction in a Pb-contaminated soil from 66% to 10% after one-month amendment with a ratio of 2 mL solution to 1g soil and the resultant Pb content in the TCLP solution was reduced to 12 from 94 mg L(-1). When the amendment ratio was increased by 5 times, the leachable Pb was further reduced to 3.8 mg L(-1) with only about 3% of the soil Pb leachable. The soil sample, containing an average of 2.7×10(3)mg Pb kg(-1), was taken from a shooting-range in Southern USA. PMID:23336925

  18. Demonstration of In-Situ Stabilization of Buried Waste at Pit G-11 at the Brookhaven National laboratory Glass Pits Disposal Site

    Energy Technology Data Exchange (ETDEWEB)

    Dwyer, B.P.; Gilbert, J.; Heiser, J.

    1999-01-01

    In 1989 BNL was added to the EPAs National Priorities List. The site is divided into seven operable units (OU). OU-I includes the former landfill area. The field task site is noted as the AOC 2C Glass Holes location. Beginning in the 1960s and continuing into the 1980s, BNL disposed of laboratory waste (glassware, chemicals and animal carcasses) in numerous shallow pits. The drivers for remediating the pits are; historical records that indicate hazardous materials may have been disposed of in the pits; ground water contamination down gradient of the pits; a test excavation of one of the glass holes that unearthed laboratory glass bottles with unidentified liquids still contained; and the fact that BNL rests atop an EPA designated sole-source aquifer. The specific site chosen for this demonstration was pit G-11. The requirements that lead to choosing this pit were; a well characterized pit and a relatively isolated pit where our construction operations would not impact on adjacent pits. The glass holes area, including pit G-11, was comprehensively surveyed using a suite of geophysical techniques (e.g., EM-31, EM-61, GPR). Prior to stabilizing the waste form a subsurface barrier was constructed to contain the entire waste pit. The pit contents were then stabilized using a cement grout applied via jet grouting. The stabilization was performed to make removal of the waste from the pit easier and safer in terms of worker exposure. The grouting process would mix and masticate the waste and grout and form a single monolithic waste form. This large monolith would then be subdivided into smaller 4 foot by 4 foot by 10-12 foot block using a demolition grout. The smaller blocks would then be easily removed from the site and disposed of in a CERCLA waste site.

  19. Demonstration of In-Situ Stabilization of Buried Waste at Pit G-11 at the Brookhaven National laboratory Glass Pits Disposal Site

    International Nuclear Information System (INIS)

    In 1989 BNL was added to the EPAs National Priorities List. The site is divided into seven operable units (OU). OU-I includes the former landfill area. The field task site is noted as the AOC 2C Glass Holes location. Beginning in the 1960s and continuing into the 1980s, BNL disposed of laboratory waste (glassware, chemicals and animal carcasses) in numerous shallow pits. The drivers for remediating the pits are; historical records that indicate hazardous materials may have been disposed of in the pits; ground water contamination down gradient of the pits; a test excavation of one of the glass holes that unearthed laboratory glass bottles with unidentified liquids still contained; and the fact that BNL rests atop an EPA designated sole-source aquifer. The specific site chosen for this demonstration was pit G-11. The requirements that lead to choosing this pit were; a well characterized pit and a relatively isolated pit where our construction operations would not impact on adjacent pits. The glass holes area, including pit G-11, was comprehensively surveyed using a suite of geophysical techniques (e.g., EM-31, EM-61, GPR). Prior to stabilizing the waste form a subsurface barrier was constructed to contain the entire waste pit. The pit contents were then stabilized using a cement grout applied via jet grouting. The stabilization was performed to make removal of the waste from the pit easier and safer in terms of worker exposure. The grouting process would mix and masticate the waste and grout and form a single monolithic waste form. This large monolith would then be subdivided into smaller 4 foot by 4 foot by 10-12 foot block using a demolition grout. The smaller blocks would then be easily removed from the site and disposed of in a CERCLA waste site

  20. In situ object counting system (ISOCSi3TM) technique: A cost-effective tool for NDA verification in IAEA Safeguards

    International Nuclear Information System (INIS)

    Nuclear material measurements using the ISOCS technique are playing an increasing role in IAEA verification activities. The ISOCS capabilities include: a high sensitivity to the presence of U and Pu; the ability to detect very small amounts of material; and the ability to measure items of different shapes and sizes. In addition, the numerical absolute efficiency calibration of a germanium detector used in the technique does not require any calibration standards or reference materials. The ISOCS modelling software performs an absolute efficiency calibration for items with various container shapes, container wall materials, material compositions, material fill-heights, U/Pu weight fractions and even heterogeneously distributed emitting materials. In a number of cases, some key parameters, such as the matrix density and U/Pu weight fraction, can be determined in addition to the emitting material mass and isotopic composition. These capabilities provide a verification solution suitable for a majority of cases where quantitative and isotopic analysis should be performed. Taking into account these advantages, the technique becomes a cost-effective solution for nuclear material non-destructive assay (NDA) verification. At present, the IAEA uses the ISOCS for a wide range of applications including the quantitative analysis of U scrap materials, U/Pu contaminated solid wastes, U fuel elements, U hold-up materials. Additionally, the ISOCS is also applied to some specific verification cases such as the measurement of PuBe neutron sources and the quantification of fission products in solid wastes. In reprocessing facilities with U/Pu waste compaction or facilities with item re-batching, the continuity-of-knowledge can be assured by applying either video surveillance systems together with seals (requiring attaching/detaching and verification activities for each seal) or verification of operator declarations using quantitative measurements for items selected on a random basis. In some cases, the first option is too expensive and places a high demand on inspector and operator time. Quantitative NDA based on the ISOCS technique verifies these materials and significantly decreases the resources required for assuring the continuity-of-knowledge. (authors)

  1. A new laboratory technique for determining the compressional wave properties of marine sediments at sonic frequencies and in situ pressures

    OpenAIRE

    McCann, Clive; Sothcott, Jeremy; Best, Angus I.

    2014-01-01

    We describe a new laboratory technique for measuring the compressional wave velocity and attenuation of jacketed samples of unconsolidated marine sediments within the acoustic (sonic) frequency range 1–10 kHz and at elevated differential (confining – pore) pressures up to 2.413 MPa (350 psi). The method is particularly well suited to attenuation studies because the large sample length (up to 0.6 m long, diameter 0.069 m) is equivalent to about one wavelength, thus giving representative bulk v...

  2. First-year evaluation of low-level waste-management stabilization techniques

    International Nuclear Information System (INIS)

    The first year of observation for effectiveness of biobarriers and herbicides in revegetation efforts demonstrated that certain practices will result in successful site stabilization: proper orientation of burial trench to reduce erosion; utilization of mulches to conserve moisture; seeding mixed perennial or annual grass species at the proper time for optimization of establishment and growth; and applying 2,4-D amine/Dicamba selective herbicide at the optimum time for enhancement of disirable grasses and reduction of competition from other species. The ultimate success or failure of a revegetation operation depends in part on the availability of equipment and manpower, weather conditions, and engineering feasibility. The data indicated that perennial grasses offered advantages over annual grasses and that the 2,4-D amine/Dicamba herbicide spray program was successful and should be expanded for next year. However, programmatic decisions should not be based on the data for 1 year, but should be based on data gathered over the full 3 years of the project

  3. Supersonic dynamic stability characteristics of the test technique demonstrator NASP configuration

    Science.gov (United States)

    Dress, David A.; Boyden, Richmond P.; Cruz, Christopher I.

    1992-01-01

    Wind tunnel tests of a National Aero-Space Plane (NASP) configuration were conducted in both test sections of the Langley Unitary Plan Wind Tunnel. The model used is a Langley designed blended body NASP configuration. Dynamic stability characteristics were measured on this configuration at Mach numbers of 2.0, 2.5, 3.5, and 4.5. In addition to tests of the baseline configuration, component buildup tests were conducted. The test results show that the baseline configuration generally has positive damping about all three axes with only isolated exceptions. In addition, there was generally good agreement between the in-pulse dynamic parameters and the corresponding static data which were measured during another series of tests in the Unitary Plan Wind Tunnel. Also included are comparisons of the experimental damping parameters with results from the engineering predictive code APAS (Aerodynamic Preliminary Analysis System). These comparisons show good agreement at low angles of attack; however, the comparisons are generally not as good at the higher angles of attack.

  4. A technique for improved stability of adaptive feedforward controllers without detailed uncertainty measurements

    International Nuclear Information System (INIS)

    Model errors in adaptive controllers for the reduction of broadband noise and vibrations may lead to unstable systems or increased error signals. Previous research on active structures with small damping has shown that the addition of a low-authority controller which increases damping in the system may lead to improved performance of an adaptive, high-authority controller. Other researchers have suggested the use of frequency dependent regularization based on measured uncertainties. In this paper an alternative method is presented that avoids the disadvantages of these methods, namely the additional complex hardware and the need to obtain detailed information on the uncertainties. An analysis is made of an adaptive feedforward controller in which a difference exists between the secondary path and the model as used in the controller. The real parts of the eigenvalues that determine the stability of the system are expressed in terms of the amount of uncertainty and the singular values of the secondary path. Modifications of the feedforward control scheme are suggested that aim to improve performance without requiring detailed uncertainty measurements. (paper)

  5. Internal fixation for intra-articular distal radius fracture (AO type C3) using condylar stabilizing technique

    International Nuclear Information System (INIS)

    Authors' fixation procedure involving their unique technique for the fracture in the title is precisely presented. In the technique, subchondral support of fragments of ventral palmar lunate bone and anatomical reintegration are thought to be important. The fixation for the AO type C3 fracture is conducted with Acu-Loc Distal Radius Plate System (Kobayashi Medical Co.) by condylar stabilizing technique for 20 patients (M 9/F 11, 60.8 years old in average). Fractures involve the comminuted Colles and Smith types of 18 and 2 cases, respectively (C3-1/7 case, C3-2/12, C3-3/1). Before and 2 weeks after surgery, multi-slice CT is performed to construct images of multiplanar inclination to calculate the radial inclination (RI) and ulnar variance (UV) from frontal images, and the palmar tilt (PT), and gap/step-off of articular surface from sagittal images with Synapse (FUJI FILM Medical Co., Ltd). Average angles or distances at the injury/after operation are respectively; RI, 16.7/22.6 degrees; PT (Colles type), -14.6/5.8 degrees; or UV; 4.3/1.0 mm; gap, 2.3/1.2 mm; step-off, 1.3/0.5 mm; which are all statistically significant improvement. Thus the procedure is thought useful for reintegrating fixation of highly depressed intra-articular fracture surface. (K.I.)

  6. Advanced Techniques for In-Situ Monitoring of Phase Transformations During Welding Using Synchrotron-Based X-Ray Diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Elmer, J W; Palmer, T A; Zhang, W; DebRoy, T

    2005-06-05

    Understanding the evolution of microstructure in welds is an important goal of welding research because of the strong correlation between weld microstructure and weld properties. To achieve this goal it is important to develop a quantitative measure of phase transformations encountered during welding in order to ultimately develop methods for predicting weld microstructures from the characteristics of the welding process. To aid in this effort, synchrotron radiation methods have been developed at Lawrence Livermore National Laboratory (LLNL) for direct observation of microstructure evolution during welding. Using intense, highly collimated synchrotron radiation, the atomic structure of the weld heat affected and fusion zones can be probed in real time. Two synchrotron-based techniques, known as spatially resolved (SRXRD) and time resolved (TRXRD) x-ray diffraction, have been developed for these investigations. These techniques have now been used to investigate welding induced phase transformations in titanium alloys, low alloy steels, and stainless steel alloys. This paper will provide a brief overview of these methods and will discuss microstructural evolution during the welding of low carbon (AISI 1005) and medium carbon (AISI 1045) steels where the different levels of carbon influence the evolution of microstructures during welding.

  7. In situ solvent formation microextraction based on ionic liquids: a novel sample preparation technique for determination of inorganic species in saline solutions.

    Science.gov (United States)

    Baghdadi, Majid; Shemirani, Farzaneh

    2009-02-23

    In this research, a novel microextraction technique based on ionic liquids (ILs) termed in situ solvent formation microextraction (ISFME) is developed. In this method, small amount of sodium hexafluorophosphate (NaPF(6), as an ion-pairing agent) was added to the sample solution containing very small amount of 1-hexyl-3-methylimidazolium tetrafluoroborate ([Hmim][BF(4)], as hydrophilic IL). A cloudy solution was formed as a result of formation of fine droplets of 1-hexyl-3-methylimidazolium hexafluorophosphate [Hmim][PF(6)]. After centrifuging, the fine droplets of the extractant phase settled to the bottom of the conical-bottom glass centrifuge tube. ISFME is a simple and rapid method for extraction and preconcentration of metal ions from water samples and can be applied for the sample solutions containing very high concentrations of salt. Furthermore, this technique is much safer in comparison with the organic solvent extraction. Reliability of the introduced methodology was evaluated by analyzing water reference material. ISFME was successfully applied to determining mercury (II) in several real water samples. Michler thioketone (TMK) was chosen as a complexing agent. Analysis was carried out using spectrophotometric detection method. Type and amount of IL, temperature and the other parameters were optimized. Under the optimum conditions, the limit of detection (LOD) was 0.7 ng mL(-1) and the relative standard deviation (R.S.D.) was 1.94% for 40 ng mL(-1) mercury. PMID:19185118

  8. Combining X-ray Absorption and X-ray Diffraction Techniques for in Situ Studies of Chemical Transformations in Heterogeneous Catalysis: Advantages and Limitations

    Energy Technology Data Exchange (ETDEWEB)

    Frenkel, A.I.; Hanson, J.; Wang, Q.; Marinkovic, N.; Chen, J.G.; Barrio, L.; Si, R.; Lopez Camara, A.; Estrella, A.M.; Rodriguez, J.A.

    2011-08-05

    Recent advances in catalysis instrumentations include synchrotron-based facilities where time-resolved X-ray scattering and absorption techniques are combined in the same in situ or operando experiment to study catalysts at work. To evaluate the advances and limitations of this method, we performed a series of experiments at the new XAFS/XRD instrument in the National Synchrotron Light Source. Nearly simultaneous X-ray diffraction (XRD) and X-ray absorption fine-structure (XAFS) measurements of structure and kinetics of several catalysts under reducing or oxidizing conditions have been performed and carefully analyzed. For CuFe{sub 2}O{sub 4} under reducing conditions, the combined use of the two techniques allowed us to obtain accurate data on kinetics of nucleation and growth of metallic Cu. For the inverse catalyst CuO/CeO{sub 2} that underwent isothermal reduction (with CO) and oxidation (with O{sub 2}), the XAFS data measured in the same experiment with XRD revealed strongly disordered Cu species that went undetected by diffraction. These and other examples emphasize the unique sensitivity of these two complementary methods to follow catalytic processes in the broad ranges of length and time scales.

  9. Combining X-ray Absorption and X-ray Diffraction Techniques for in Situ Studies of Chemical Transformations in Heterogeneous Catalysis:Advantages and Limitations

    Energy Technology Data Exchange (ETDEWEB)

    A Frenkel; Q Wang; N Marinkovic; J Chen; L Barrio; R Si; A Lopez Camara; A Estella; J Rodriquez; J Hanson

    2011-12-31

    Recent advances in catalysis instrumentations include synchrotron-based facilities where time-resolved X-ray scattering and absorption techniques are combined in the same in situ or operando experiment to study catalysts at work. To evaluate the advances and limitations of this method, we performed a series of experiments at the new XAFS/XRD instrument in the National Synchrotron Light Source. Nearly simultaneous X-ray diffraction (XRD) and X-ray absorption fine-structure (XAFS) measurements of structure and kinetics of several catalysts under reducing or oxidizing conditions have been performed and carefully analyzed. For CuFe{sub 2}O{sub 4} under reducing conditions, the combined use of the two techniques allowed us to obtain accurate data on kinetics of nucleation and growth of metallic Cu. For the inverse catalyst CuO/CeO{sub 2} that underwent isothermal reduction (with CO) and oxidation (with O{sub 2}), the XAFS data measured in the same experiment with XRD revealed strongly disordered Cu species that went undetected by diffraction. These and other examples emphasize the unique sensitivity of these two complementary methods to follow catalytic processes in the broad ranges of length and time scales.

  10. In situ electrochemical impedance spectroscopy/synchrotron radiation grazing incidence X-ray diffraction-A powerful new technique for the characterization of electrochemical surfaces and interfaces

    International Nuclear Information System (INIS)

    A marriage of electrochemical impedance spectroscopy (EIS) and in situ synchrotron radiation grazing incidence X-ray diffraction (SR-GIXRD) has provided a powerful new technique for the elucidation of the mechanistic chemistry of electrochemical systems. In this study, EIS/SR-GIXRD has been used to investigate the influence of metal ion buffer calibration ligands, along with natural organic ligands in seawater, on the behaviour of the iron chalcogenide glass ion-selective electrode (ISE). The SR-GIXRD data demonstrated that citrate - a previously reported poor iron calibration ligand for the analysis of seawater - induced an instantaneous and total dissolution of crystalline GeSe and Sb2Se3 in the modified surface layer (MSL) of the ISE, while natural organic ligands in seawater and a mixture of ligands in a mimetic seawater ligand system protected the MSL's crystalline inclusions of GeSe and Sb2Se3 from oxidative attack. Expectedly, the EIS data showed that citrate induced a loss in the medium frequency time constant for the MSL of the ISE, while seawater's natural organic ligands and the mimetic ligand system preserved the medium frequency EIS response characteristics of the ISE's MSL. The new EIS/SR-GIXRD technique has provided insights into the suitability of iron calibration ligands for the analysis of iron in seawater

  11. Combining X-ray Absorption and X-ray Diffraction Techniques for in Situ Studies of Chemical Transformations in Heterogeneous Catalysis: Advantages and Limitations

    International Nuclear Information System (INIS)

    Recent advances in catalysis instrumentations include synchrotron-based facilities where time-resolved X-ray scattering and absorption techniques are combined in the same in situ or operando experiment to study catalysts at work. To evaluate the advances and limitations of this method, we performed a series of experiments at the new XAFS/XRD instrument in the National Synchrotron Light Source. Nearly simultaneous X-ray diffraction (XRD) and X-ray absorption fine-structure (XAFS) measurements of structure and kinetics of several catalysts under reducing or oxidizing conditions have been performed and carefully analyzed. For CuFe2O4 under reducing conditions, the combined use of the two techniques allowed us to obtain accurate data on kinetics of nucleation and growth of metallic Cu. For the inverse catalyst CuO/CeO2 that underwent isothermal reduction (with CO) and oxidation (with O2), the XAFS data measured in the same experiment with XRD revealed strongly disordered Cu species that went undetected by diffraction. These and other examples emphasize the unique sensitivity of these two complementary methods to follow catalytic processes in the broad ranges of length and time scales.

  12. Optical and Acoustical Techniques for Non-viral Gene Delivery to Mammalian Cells and In-situ Study of Cytoskeletal Mechanics

    Science.gov (United States)

    Ma, Zili

    Since the first optical microscope invented by Anton van Leeuwenhoek in 1674, the great development of laser technique and its applications in biophotonics have helped us reveal the mechanisms underlying numerous biological activities gradually. The introduction of fs lasers to the studies of biology has emerged as a fast developing area calling for the efforts and skills both from optics and electric engineering and biology and medicine. Due to the fast update of laser source techniques, there has been an increasing number of commercialized fs lasers available for this growing market of biophotonics. To better utilize the potential offered by fs lasers, we studied the technique of optical gene delivery and tried to narrow the gap between laboratorial research and industrial/clinical applications, in that the strict experimental conditions of specific optical laboratorial studies are generally not appropriate for the practical biological applications. To carry out our experiments, we built a two-stage amplifier fs laser system to generate the desired pulse train. The laser pulse train was coupled into an invert fluorescence microscope for the imaging and manipulation of each cell. To overcome limitations brought by the tight focus of laser beam due to high NA objective, we introduced gold nanorods (GNRs), a metallic nanomaterial, with tunable optical property. With these additional membrane for membrane permeabilization, which could significantly improve the manipulation speed than that based on the tightly focused laser. We used GFP plasmid to demonstrate the applications of this technique in gene delivery, and successfully transfected and GFP-expressed cells were observed one day after the optical transfection. Additionally, as an important trend of biophotonics, the integration of optics with microfluidic chips has become the new frontier of both biology and engineering. Here we firstly demonstrated a technique of gene delivery by an on-chip device generating surface acoustic waves, which not only achieved a high efficiency of cells permeabilization in a quick speed, but also allowed us to observe the permeabilization process in real time by microscope. This device is also compatible with biophotonics studies based on fs laser, which can be further developed as a powerful tool for optical gene delivery with the capability of precisely controlling the fluid on-chip by SAW. SAW devices could also achieve exogenous gene delivery through the cell membrane without the need of adding chemical agents. Our results showed that the membrane of mammalian adherent cells could be effectively perforated transiently by applying a SAW. The transfection of pEGFP plasmids into endothelial cells was carried out successfully via this SAW-induced cell perforation. The expression of GFP was observed after 24-hour incubation subsequent to the SAW treatment. In regard to the application of fs lasers in cellular and subcellular level studies, we applied the optical nanoscissoring technique based on fs lasers in biomechanical studies to study the mechanical properties of single SF in-situ. Integrated into a confocal microscope, the fs laser showed great power in manipulating targeted in-situ subcellular structures under real-time imaging without damaging nearby regions. Here, how oxidative challenges would alter the mechanical properties of SFs in myoblasts was firstly investigated using the optical nanoscissoring technique to comprehend the whole picture of muscle tissue injury and repair from the basics. The prestress of stress fibers after the oxidative challenges was found through our modified viscoelastic retraction model and experiment result.

  13. Estimation of hydrogen bond distribution in coal through the analysis of OH stretching bands in diffuse reflectance infrared spectrum measured by in-situ technique

    Energy Technology Data Exchange (ETDEWEB)

    Miura, K.; Mae, K.; Li, W.; Kusakawa, T.; Morozumi, F.; Kumano, A. [Kyoto University, Kyoto (Japan). Dept. of Chemical Engineering

    2001-06-01

    A new method was presented to estimate the strength distribution of hydrogen bonds in coal. The hydrogen bonds include the coal intramolecule hydrogen bonds and coal-water hydrogen bonds formed by hydroxyls in coal. The method analyzes the FTIR spectrum ranging from 2400 to 3700 cm{sup -1} obtained using the in-situ diffuse reflectance IR Fourier transform (DRIFT) technique with neat, undiluted, coal samples. The FTIR spectra during the heat-up of eight coals (seven Argonne premium coals and an Australian born wocla), an ion-exchange resin, and a lignin were measured every 20{degree}C from room temperature to 300{degree}C. Each spectrum was divided into six hydrogen-bonded absorption bands by a curve-resolving method, then the amount of hydroxyls contributing to each hydrogen bond was estimated by Beer's law by using different absorptivity for each band. The strength of each hydrogen bond was estimated using a relation presented by Drago et al. That is known as one of the 'linear enthalpy-spectroscopic shift relations'. Using this analysis method, changes in hydrogen bond distributions (HBD) with increasing temperature were successfully estimated for all the samples examined. By utilizing the HBD the changes in enthalpies associated with the desorption of adsorbed water, the glass transition, and the decomposition of COOH groups were well estimated. Only FTIR spectra measurements were found to be enough to obtain such enthalpies. This greatly simplified the calculation procedure and increased the accuracy of the enthalpies. The validity of the proposed in situ FTIR measurement method and the analysis method for obtaining HBD was well clarified. 46 refs., 14 figs., 1 tab.

  14. In situ (LaxGd1-x)B6 cathode materials prepared by the spark plasma sintering technique

    Science.gov (United States)

    Bao, Li-Hong; Zhang, Jiu-Xing; Zhang, Ning; Li, Xiao-Na; Zhou, Shen-Lin

    2012-03-01

    Polycrystalline hexaborides (LaxGd1-x)B6 (x=0, 0.6, 0.8, 1) were synthesized by the reactive spark plasma sintering (SPS) method using a mixed powder of LaH2, GdH2 and B. The effects of La doping contents on the crystal structure, grain orientation, electrical resistivity and thermionic emission properties were investigated by x-ray diffraction, electron backscattered diffraction and emission current measurements, respectively. The results indicate that the high-purity (LaxGd1-x)B6 cathode sintered by SPS exhibits high densification (>97%) and a high value of the Vickers hardness (2375?kg?mm-2). When the La doping contents are increased, the thermionic emission current density increases from 11.00 to 36.20?A?cm-2. Thus, the SPS technique is a suitable method for synthesizing dense rare-earth hexaborides with excellent properties.

  15. DEVELOPMENT, CHARACTERIZATION & STABILIZATION OF POORLY WATER SOLUBLE DRUGS UTILIZING SOLID DISPERSION TECHNIQUES BY USING ? - CYCLODEXTRIN

    Directory of Open Access Journals (Sweden)

    Rakesh Singh

    2013-01-01

    Full Text Available Telmisartan (TLM is an angiotensin II receptor antagonist used in the treatment of hypertension. According to BCS (biopharmaceutical classification system Telmisartan belongs to class II drug, and it is practically insoluble in water and it shows low dissolution profile and poor absorption. The present study is to improve the solubility of Telmisartan by forming complexation with ?- CD by using four convenient methods viz physical mixing method, kneading method, and solvent evaporation fusion method at different molar ratios of 1:1, dissolution studies were carried out in pH 7.4 phosphate buffer. The cyclodextrin complexes formulated by employing 1:1 (drug: complexing agent with kneading technique showed higher drug release. Keywords: Telmisartan, inclusion complex, ? - cyclodextrin, physical, kneading, solvent evaporation & fusion method.

  16. [Pilon fractures. Part 2: Repositioning and stabilization technique and complication management].

    Science.gov (United States)

    Krettek, C; Bachmann, S

    2015-02-01

    The management of complex pilon fractures with soft tissue injuries has seen many trends, with changes toward staged protocols of temporary external fixation followed by delayed open reduction and internal fixation (ORIF), minimally invasive percutaneous plate osteosynthesis (MIPPO) techniques and special implants, the benefits of negative pressure wound sealing and early "fix and flap" efforts to reconstruct soft tissue defects. Reduction and fixation must involve cautious management and careful handling of soft tissue in order to minimize the well-known complications of this difficult fracture. With these changes, the rate of soft tissue complications, infections and non-unions has decreased. The target remains the anatomical reconstruction of the articular surface as well as the geometric integrity of the distal tibia and fibula. Currently it is still unclear how much articular anatomy and perfection in reduction is needed as the radiographic results do not always correlate with the clinical results. PMID:25673229

  17. A comparison of multiple regression and neural network techniques for mapping in situ pCO2 data

    International Nuclear Information System (INIS)

    Using about 138,000 measurements of surface pCO2 in the Atlantic subpolar gyre (50-70 deg N, 60-10 deg W) during 1995-1997, we compare two methods of interpolation in space and time: a monthly distribution of surface pCO2 constructed using multiple linear regressions on position and temperature, and a self-organizing neural network approach. Both methods confirm characteristics of the region found in previous work, i.e. the subpolar gyre is a sink for atmospheric CO2 throughout the year, and exhibits a strong seasonal variability with the highest undersaturations occurring in spring and summer due to biological activity. As an annual average the surface pCO2 is higher than estimates based on available syntheses of surface pCO2. This supports earlier suggestions that the sink of CO2 in the Atlantic subpolar gyre has decreased over the last decade instead of increasing as previously assumed. The neural network is able to capture a more complex distribution than can be well represented by linear regressions, but both techniques agree relatively well on the average values of pCO2 and derived fluxes. However, when both techniques are used with a subset of the data, the neural network predicts the remaining data to a much better accuracy than the regressions, with a residual standard deviation ranging from 3 to 11 ?atm. The subpolar gyre is a net sink of CO2 of 0.13 Gt-C/yr using the multiple linear regressions and 0.15 Gt-C/yr using the neural network, on average between 1995 and 1997. Both calculations were made with the NCEP monthly wind speeds converted to 10 m height and averaged between 1995 and 1997, and using the gas exchange coefficient of Wanninkhof

  18. Chemiluminescence - a useful technique for characterizing the stability and forecasting the lifetime of polymer materials for nuclear applications

    International Nuclear Information System (INIS)

    The chemiluminescence (CL) mechanism is tightly related to the polymer oxidation mechanism both of them proceeding by means of peroxidic species (free radicals) and hydroperoxides of the polymer. The CL emission is strongly influenced by the stabilizing antioxidants, the efficiency and concentration of which being correlated with the CL signal.. This paper presents the mechanism of CL emission, the methods of materials characterization of polymers based on polyethylene and additives, evaluation of the materials lifetime as well as recent experimental examples regarding the characterization of the efficiency of some stabilizing agents (antirad agents of the type of radical captors or energy deactivators). Also the study of some synergic effects, and the diagnosis of degradation of some cable isolations exposed to electrical or radiation fields. The results obtained were correlated with those obtained by other techniques, namely, IR, UV spectroscopy, thermal analysis, electrical tests, oxygen absorption, chemical and mechanical tests, which demonstrated the high sensitivity of the method. Since the CL tests need only small material amounts, of the order of 2-4 mg, the method can be used for characterization of raw materials and products of fabrication as well as in the diagnosing the degradation of samples exposed to service-like conditions to evaluate the lifetime expectation or the remaining service time

  19. Investigation of thermal stability and fingerprint spectra of energetic 1,2,3-triazole using pulsed photoacoustic pyrolysis technique

    Science.gov (United States)

    Rao, K. S.; Chaudhary, A. K.; Yehya, F.

    2015-10-01

    This paper reports on a comparative study of UV and visible radiation-based pulsed photoacoustic (PA) pyrolysis technique examining thermal stability and acoustic fingerprint spectra of a newly synthesized high-energy molecule named 1-(2,4-dinitrobenzyl)-4-nitro-1H-1,2,3-triazole (S 6). The thermal PA spectra of S 6 were recorded in temperatures ranging between 30 and 350 °C using second and fourth harmonic wavelengths (i.e., 532 and 266 nm), obtained from Q-switched Nd:YAG laser pulses of duration 7 ns at 10 Hz repetition rate. The PA results are further compared with TG-DTA data to understand the release mechanism of NO2 along with other gaseous by-products. The difference in thermal PA spectra of S 6 which follows two different mechanisms, such as vibronic transition V-V and V-T relaxation in NO2 functional group, while electronic ?* ? n transition in the entire molecule, is due to selection of visible and UV wavelengths. In addition, the effect of data acquisition time and incident laser energy has been examined in order to understand the behavior of acoustic modes of a PA cavity at the desired vapor temperature. The stability of the compound is also evaluated on the basis of thermal quality factor (Q), of PA cavity.

  20. Effect of heat treatment on the structure and stability of multiwalled carbon nanotubes produced by catalytic chemical vapor deposition technique

    International Nuclear Information System (INIS)

    Highlights: ? Post synthesis heat treatment of the nanotubes introduces long range ordering of the layer planes. ? Increased purity and thermal stability of the tubes has been achieved by the removal of catalyst impurity. ? Development of the sword-in-scabbard structure in the multiwalled carbon nanotubes due to heat treatment. ? Improved performance (electrical and mechanical) of the polymer composites using heat treated carbon nanotubes as reinforcement. - Abstract: The multiwalled carbon nanotubes (MWCNTs) produced by catalytic chemical vapor deposition (CCVD) route were heat treated to 2500 °C to improve the structure, morphology and purity level. The process has lead to substantial reduction in the catalytic impurity along with an improved thermal stability and degree of graphitization of these tubes that can possibly lead to its better utilization in various applications. The structural changes following heat treatment have been correlated using various characterization techniques such as Raman spectroscopy, X-ray diffraction, scanning electron microscopy, high resolution transmission electron microscopy, thermo gravimetric analysis and electron paramagnetic resonance spectroscopy. The electrical and mechanical properties of the polymer composites prepared with heat treated MWCNT show improved properties over the one prepared by as produced MWCNT.

  1. Effect of heat treatment on the structure and stability of multiwalled carbon nanotubes produced by catalytic chemical vapor deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Maheshwari, Priyanka H., E-mail: hedap@mail.nplindia.ernet.in [Physics and Engineering of Carbon, Division of Materials Physics and Engineering, National Physical Laboratory, CSIR, New Delhi (India); Singh, R.; Mathur, R.B. [Physics and Engineering of Carbon, Division of Materials Physics and Engineering, National Physical Laboratory, CSIR, New Delhi (India)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Post synthesis heat treatment of the nanotubes introduces long range ordering of the layer planes. Black-Right-Pointing-Pointer Increased purity and thermal stability of the tubes has been achieved by the removal of catalyst impurity. Black-Right-Pointing-Pointer Development of the sword-in-scabbard structure in the multiwalled carbon nanotubes due to heat treatment. Black-Right-Pointing-Pointer Improved performance (electrical and mechanical) of the polymer composites using heat treated carbon nanotubes as reinforcement. - Abstract: The multiwalled carbon nanotubes (MWCNTs) produced by catalytic chemical vapor deposition (CCVD) route were heat treated to 2500 Degree-Sign C to improve the structure, morphology and purity level. The process has lead to substantial reduction in the catalytic impurity along with an improved thermal stability and degree of graphitization of these tubes that can possibly lead to its better utilization in various applications. The structural changes following heat treatment have been correlated using various characterization techniques such as Raman spectroscopy, X-ray diffraction, scanning electron microscopy, high resolution transmission electron microscopy, thermo gravimetric analysis and electron paramagnetic resonance spectroscopy. The electrical and mechanical properties of the polymer composites prepared with heat treated MWCNT show improved properties over the one prepared by as produced MWCNT.

  2. In-situ measurement of epithelial tissue optical properties: Development and implementation of diffuse reflectance spectroscopy techniques

    Science.gov (United States)

    Wang, Quanzeng

    Cancer is a severe threat to human health. Early detection is considered the best way to increase the chance for survival. While the traditional cancer detection method, biopsy, is invasive, noninvasive optical diagnostic techniques are revolutionizing the way that cancer is diagnosed. Reflectance spectroscopy is one of these optical spectroscopy techniques showing promise as a diagnostic tool for pre-cancer detection. When a neoplasia occurs in tissue, morphologic and biochemical changes happen in the tissue, which in turn results in the change of optical properties and reflectance spectroscopy. Therefore, a pre-cancer can be detected by extracting optical properties from reflectance spectroscopy. This dissertation described the construction of a fiberoptic based reflectance system and the development of a series of modeling studies. This research is aimed at establishing an improved understanding of the optical properties of mucosal tissues by analyzing reflectance signals at different wavelengths. The ultimate goal is to reveal the potential of reflectance-based optical diagnosis of pre-cancer. The research is detailed in Chapter 3 through Chapter 5. Although related with each other, each chapter was designed to become a journal paper ultimately. In Chapter 3, a multi-wavelength, fiberoptic system was constructed, evaluated and implemented to determine internal tissue optical properties at ultraviolet A and visible wavelengths. A condensed Monte Carlo model was deployed to simulate light-tissue interaction and generate spatially distributed reflectance data. These data were used to train an inverse neural network model to extract tissue optical properties from reflectance. Optical properties of porcine mucosal and liver tissues were finally measured. In Chapter 4, the condensed Monte Carlo method was extended so that it can rapidly simulate reflectance from a single illumination-detection fiber thus enabling the calculation of large data sets. The model was implemented to study spectral reflectance changes due to breast cancer. The effect of adding an illumination-detection fiber to a linear array fiber for optical property determination was also evaluated. In Chapter 5, an investigation of extracting the optical properties from two-layer tissues was performed. The relationship between spatially-resolved reflectance distributions and optical properties in two-layer tissue was investigated. Based on all the aforementioned studies, spatially resolved reflectance system coupled with condensed Monte Carlo and neural network models was found to be objective and appear to be sensitive and accurate in quantitatively assessing optical property change of mucosal tissues.

  3. Engineering excitonic dynamics and environmental stability of post-transition metal chalcogenides by pyridine functionalization technique

    Science.gov (United States)

    Meng, Xiuqing; Pant, Anupum; Cai, Hui; Kang, Jun; Sahin, Hasan; Chen, Bin; Wu, Kedi; Yang, Sijie; Suslu, Aslihan; Peeters, F. M.; Tongay, Sefaattin

    2015-10-01

    Owing to their strong photon emission, low excitonic binding energies, and nearly-ideal band offset values for water splitting reactions, direct gap quasi-2D gallium chalcogenides are potential candidates for applications in energy harvesting, optoelectronics, and photonics. Unlike other 2D materials systems, chemical functionalization of gallium chalcogenides is still at its seminal stages. Here, we propose vapor phase pyridine intercalation technique to manipulate optical properties of gallium chalcogenides. After functionalization, the excitonic dynamics of quasi-2D GaSe change significantly as evidenced by an increase in integrated PL intensity and emergence of a new emission feature that is below the band edge. Based on our DFT calculations, we attribute these to formation of bound exciton complexes at the trap sites introduced by chemical reaction between pyridine and GaSe. On the contrary, pyridine functionalization does not impact the optical properties of GaTe, instead treats GaTe surface to prevent oxidization of tellurium atoms. Overall, results suggest novel ways to control properties of gallium chalcogenides on demand and unleash their full potential for a range of applications in photonics and optoelectronics.Owing to their strong photon emission, low excitonic binding energies, and nearly-ideal band offset values for water splitting reactions, direct gap quasi-2D gallium chalcogenides are potential candidates for applications in energy harvesting, optoelectronics, and photonics. Unlike other 2D materials systems, chemical functionalization of gallium chalcogenides is still at its seminal stages. Here, we propose vapor phase pyridine intercalation technique to manipulate optical properties of gallium chalcogenides. After functionalization, the excitonic dynamics of quasi-2D GaSe change significantly as evidenced by an increase in integrated PL intensity and emergence of a new emission feature that is below the band edge. Based on our DFT calculations, we attribute these to formation of bound exciton complexes at the trap sites introduced by chemical reaction between pyridine and GaSe. On the contrary, pyridine functionalization does not impact the optical properties of GaTe, instead treats GaTe surface to prevent oxidization of tellurium atoms. Overall, results suggest novel ways to control properties of gallium chalcogenides on demand and unleash their full potential for a range of applications in photonics and optoelectronics. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr04879f

  4. Depth profiling of hydrogen isotopes in metals by elastic recoil detection and nuclear reaction techniques under in-situ conditions

    International Nuclear Information System (INIS)

    The application of the ERD-technique with 2.8 MeV and 25 MeV ?-particles respectively and of the specific nuclear reaction D(d,p)T for the determination of hydrogen isotopes in metals is described in detail. - The methods were applied to hydrided and/or deuterated elements (Ti, Zr, Pd), alloys (Pd0.92Y0.08, Fecralloy, steels), intermetallic compounds (TiMn- and ZrMn-Laves phases) and a Ti/Cu-target containing all the three hydrogen isotopes. - Images are obtained about the hydrogen depth distribution in near surface regions of the materials (roughly 400 nm in case of 2.8 MeV ERD, 200 ?m in case of 25 MeV ERD, and 500 nm in case of D(d,p)T). By aid of standardization the hydrogen content of a number of samples was determined. Information was obtained about the presence of impurities in the specimens. (orig./PW)

  5. Applications of a new magnetic monitoring technique to in situ evaluation of fatigue damage in ferrous components

    International Nuclear Information System (INIS)

    This project consisted of research into the use of magnetic inspection methods for the estimation of fatigue life of nuclear pressure vessel steel. Estimating the mechanical and magnetic properties of ferromagnetic materials are closely interrelated, therefore, measurements of magnetic properties could be used to monitor the evolution of fatigue damage in specimens subjected to cyclic loading. Results have shown that is possible to monitor the fatigue damage nondestructively by magnetic techniques. For example, in load-controlled high-cycle fatigue tests, it has been found that the plastic strain and coercivity accumulate logarithmically during the fatigue process. Thus a quantitative relationship between coercivity and the number of fatigue cycles could be established based on two empirical coefficients, which can be determined from the test conditions and material properties. Also it was found that prediction of the onset of fatigue failure in steels was possible under certain conditions. In strain-controlled low cycle fatigue, critical changes in Barkhausen emissions, coercivity and hysteresis loss occurred in the last ten to twenty percent of fatigue life

  6. The Load Analysis of a Small Grid System and Its Stability Improvement using Modern Techniques

    International Nuclear Information System (INIS)

    Load flow study for three phase balanced power system can be carried out using various numerical techniques. The most prominent are Gauss-Seidel and Newton-Raphson methods. Besides these Gauss-Seidel and Newton-Raphson methods some other dedicated software's have also been utilized for such purposes. In this research work Gauss-Seidel and Newton-Raphson methods have been employed with MATLAB program. Three different cases have been studied and analyzed. Initially, the first two cases were analyzed comprising three buses each, while the third case has been analyzed for small grid of six buses. The power flow has been analyzed from different generating units to different loads, and transmission line losses have also been analyzed. The results obtained from the POWER WORLD software for small grid of six nodes has been compared with Gauss-Seidel and Newton-Raphson methods, and found promising results. In addition, the effect of small perturbation on certain node and its consequent reflection on other six nodes has also been analyzed. (author)

  7. Engineering excitonic dynamics and environmental stability of post-transition metal chalcogenides by pyridine functionalization technique.

    Science.gov (United States)

    Meng, Xiuqing; Pant, Anupum; Cai, Hui; Kang, Jun; Sahin, Hasan; Chen, Bin; Wu, Kedi; Yang, Sijie; Suslu, Aslihan; Peeters, F M; Tongay, Sefaattin

    2015-10-01

    Owing to their strong photon emission, low excitonic binding energies, and nearly-ideal band offset values for water splitting reactions, direct gap quasi-2D gallium chalcogenides are potential candidates for applications in energy harvesting, optoelectronics, and photonics. Unlike other 2D materials systems, chemical functionalization of gallium chalcogenides is still at its seminal stages. Here, we propose vapor phase pyridine intercalation technique to manipulate optical properties of gallium chalcogenides. After functionalization, the excitonic dynamics of quasi-2D GaSe change significantly as evidenced by an increase in integrated PL intensity and emergence of a new emission feature that is below the band edge. Based on our DFT calculations, we attribute these to formation of bound exciton complexes at the trap sites introduced by chemical reaction between pyridine and GaSe. On the contrary, pyridine functionalization does not impact the optical properties of GaTe, instead treats GaTe surface to prevent oxidization of tellurium atoms. Overall, results suggest novel ways to control properties of gallium chalcogenides on demand and unleash their full potential for a range of applications in photonics and optoelectronics. PMID:26419224

  8. Clasificación molecular del cáncer de mama, obtenida a través de la técnica de hibridación in situ cromogénica (CISH) / Molecular classification of breast cancer patients obtained through the technique of chromogenic in situ hybridization (CISH)

    Scientific Electronic Library Online (English)

    Ángel, Fernández; Aldo, Reigosa.

    2013-12-01

    Full Text Available El cáncer de mama es una enfermedad heterogénea compuesta de un número creciente de subtipos biológicos, con una sustancial variabilidad en la evolución de la enfermedad dentro de cada categoría. El objetivo del presente trabajo fue clasificar las muestras objeto a estudio de acuerdo a las clases mo [...] leculares de carcinoma de mama: luminal A, luminal B, HER2 y triple negativo, considerando el estado de amplificación de HER2 obtenido a través de la técnica de hibridación in situ cromogénica (CISH). La muestra estuvo constituida por 200 biopsias fijadas en formol al 10%, procesadas por las técnicas habituales hasta la inclusión en parafina, correspondientes a pacientes diagnosticadas con carcinoma ductal infiltrante de la mama, procedentes de consulta privada y del Instituto de Oncología “Dr. Miguel Pérez Carreño”, con estudio inmunohistoquímico (IHQ) para receptores hormonales y HER2 realizado en el Hospital Metropolitano del Norte de Valencia, Venezuela. La clasificación molecular de los tumores de las pacientes, considerando la expresión de los Receptores de Estrógeno (RE) y Receptores de Progesterona (RP) a través de IHQ y la amplificación de HER2 por CISH, permitió agrupar en las diferentes clases moleculares los casos calificados inicialmente como desconocidos, debido a que tenían un resultado indeterminado (2+) para la expresión de HER2 por IHQ; asimismo, esta clasificación ocasionó que algunos casos considerados inicialmente en una clase molecular pasaron a otra clase, posterior a la revaloración del estado de HER2 a través de CISH. Abstract in english Breast cancer is a heterogeneous disease composed of a growing number of biological subtypes, with substantial variability of the disease progression within each category. The aim of this research was to classify the samples object of study according to the molecular classes of breast cancer: lumina [...] l A, luminal B, HER2 and triple negative, as a result of the state of HER2 amplification obtained by the technique of chromogenic in situ hybridization (CISH). The sample consisted of 200 biopsies fixed in 10% formalin, processed by standard techniques up to paraffin embedding, corresponding to patients diagnosed with invasive ductal carcinoma of the breast. These biopsies were obtained from patients from private practice and the Institute of Oncology “Dr. Miguel Pérez Carreño", for immunohistochemistry (IHC) of hormone receptors and HER2 made in the Hospital Metropolitano del Norte, Valencia, Venezuela. The molecular classification of the patient’s tumors considering the expression of estrogen and progesterone receptors by IHC and HER2 amplification by CISH, allowed those cases originally classified as unknown, since they had an indeterminate (2+) outcome for HER2 expression by IHC, to be grouped into the different molecular classes. Also, this classification permitted that some cases, initially considered as belonging to a molecular class, were assigned to another class, after the revaluation of the HER2 status by CISH.

  9. Improving the mechanical properties of polyamide 6-nanosilica nanocomposites by combining masterbatch technique with in situ polymerization

    Scientific Electronic Library Online (English)

    Qijie, Xu; Xiaohong, Li; Fangfei, Chen; Zhijun, Zhang.

    2014-07-01

    Full Text Available Um masterbatch (MA) reativo de poliamida 6 (PA6)/SiO2 contendo 20% (fração de massa) de nano-SiO2 foi preparado. Posteriormente, o MA reativo preparado foi usado como carga no preparo de nanocompósitos PA6/SiO2 (RA). A estrutura do RA foi analisada por espectrometria no infravermelho por transformad [...] a de Fourier (FTIR), microscopia eletrônica de transmissão (TEM), difratometria de raios X (XRD), microscopia eletrônica de varredura (SEM) e microscopia óptica de luz polarizada (POM). A estabilidade térmica e o comportamento de cristalização do RA foram avaliados por análise termogravimétrica (TGA) e calorimetria exploratória diferencial (DSC). OS resultados indicaram que as cadeias moleculares de PA6 estavam ancoradas na superfície do nano-SiO2 através de ligações químicas entre a superfície de grupos amino do nano-SiO2 e do monômero da ?-caprolactama ou pré-polímero da PA6. Como resultado, uma camada interfacial flexível foi formada, melhorando a compatibilidade do nano-SiO2 com a matriz de PA6. Além disso, o efeito no nano-SiO2 apresentou melhoras nas propriedades mecânicas do RA. Devido ao efeito de impedimento de movimento das cadeias moleculares da PA6 pelas partículas de nano-SiO2, o tamanho da esfera cristalina de PA6 foi menor e sua forma cristalina também foi afetada. A massa molar da matriz de PA6 tende a decair gradualmente com o aumento do conteúdo nano-SiO2. Abstract in english A reactive polyamide 6 (PA6)/SiO2 masterbatch (MA) containing 20% (mass fraction) of nano-SiO2 was prepared readily. Furthermore, the as-prepared reactive MA was used as a filler to prepare PA6/SiO2 nanocomposites (RA). The structure of RA was analyzed by means of Fourier transform infrared spectrop [...] hotometry (FTIR), transmission electron microscopy (TEM), powder X-ray diffractometry (XRD), scanning electronic microscopy (SEM) and polarizing microscopy (POM). Thermal stability and crystallization behaviors of RA were evaluated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Findings indicated that the PA6 molecular chains were anchored on the surface of nano-SiO2 through chemical bonding between the surface amino groups of nano-SiO2 and ?-caprolactam monomer or prepolymer of PA6. As a result, a flexible interfacial layer was formed, thereby improving the compatibility of nano-SiO2 with PA6 matrix. Moreover, the enhancement effect of nano-SiO2 led to the improved mechanical properties of RA. Besides, due to the hindering effect of nano-SiO2 particles to the movement of PA6 molecular chains, the size of the PA6 spherocrystal was smaller, and its crystalline form was also affected. Furthermore, the molecular weight of the PA6 matrix tended to decrease gradually with increasing nano-SiO2 content.

  10. Implementation of field techniques to stabilize abandoned oil wells - Boyd's creek, Kentucky

    International Nuclear Information System (INIS)

    At Boyd's Creek, commercial crude-oil drilling production began in the early 1860s. Countless unrecorded exploration wells were drilled and many have been found to be improperly abandoned. The Corniferous limestone is the first oil producing interval and is situated at an average subsurface depth of 135 feet. The potential for impacting natural resources is high because of the shallow depth(s) of the Corniferous limestone and the presence of overlying artesian sulfur-water zones which routinely mix with brine and oil in uncased boreholes. The occurrence of limestone related (karstic) features, such as fractures and dissolution cavities, and the close proximity of the Boyd's Creek oil field to nearby surface streams are also of concern. Initially, two abandoned wells were identified as flowing into nearby streams. Pursuant to federal removal authority provided by Subsection (c) of Section 311 of the Federal Water Pollution Control Act in accordance with Subtitle B of the Oil Pollution Act of 1990 and the National Contingency Plan, the Environmental Protection Agency has initiated cleanup operations within properties nearest to Boyd's Creek. Most wells are difficult to identify because they lack any casing strings and/or they have been buried with soil to hide uncontrolled flows at the surface. Field operations have included the utilization of multiple geophysical techniques to identify anomaly areas thought to represent buried unplugged wells. These include the excavation of surface soils down to the underlying limestone bedrock to search for cable tool and rotary boreholes, the drilling out of old wells using conventional industry technology and standards to plug them permanently with cement, the construction of temporary underflow dams downgradient from identified oil spills to minimize impacts on Boyd's Creek and its adjoining tributaries, and the burning of spilled product in temporary holding pits to minimize associated cleanup cost

  11. Accuracy assessment of water vapour measurements from in situ and remote sensing techniques during the DEMEVAP 2011 campaign at OHP

    Directory of Open Access Journals (Sweden)

    O. Bock

    2013-10-01

    Full Text Available The Development of Methodologies for Water Vapour Measurement (DEMEVAP project aims at assessing and improving humidity sounding techniques and establishing a reference system based on the combination of Raman lidars, ground-based sensors and GPS. Such a system may be used for climate monitoring, radiosonde bias detection and correction, satellite measurement calibration/validation, and mm-level geodetic positioning with Global Navigation Satellite Systems. A field experiment was conducted in September–October 2011 at Observatoire de Haute-Provence (OHP. Two Raman lidars (IGN mobile lidar and OHP NDACC lidar, a stellar spectrometer (SOPHIE, a differential absorption spectrometer (SAOZ, a sun photometer (AERONET, 5 GPS receivers and 4 types of radiosondes (Vaisala RS92, MODEM M2K2-DC and M10, and Meteolabor Snow White participated in the campaign. A total of 26 balloons with multiple radiosondes were flown during 16 clear nights. This paper presents preliminary findings from the analysis of all these data sets. Several classical Raman lidar calibration methods are evaluated which use either Vaisala RS92 measurements, point capacitive humidity measurements, or GPS integrated water vapour (IWV measurements. A novel method proposed by Bosser et al. (2010 is also tested. It consists in calibrating the lidar measurements during the GPS data processing. The methods achieve a repeatability of 4–5%. Changes in the calibration factor of IGN Raman lidar are evidenced which are attributed to frequent optical re-alignments. When modelling and correcting the changes as a linear function of time, the precision of the calibration factors improves to 2–3%. However, the variations in the calibration factor, and hence the absolute accuracy, between methods and types of reference data remain at the level of 7%. The intercomparison of radiosonde measurements shows good agreement between RS92 and Snow White measurements up to 12 km. An overall dry bias is found in the measurements from both MODEM radiosondes. Investigation of situations with low RH values (< 10%RH in the lower and middle troposphere reveals, on occasion, a lower RH detection limit in the Snow White measurements compared to RS92 due to a saturation of the Peltier device. However, on other occasions, a dry bias is found in RS92, instead. On average, both RS92 and Snow White measurements show a slight moist bias at night-time compared to GPS IWV, while the MODEM measurements show a large dry bias. The IWV measurements from SOPHIE (night-time and SAOZ (daytime spectrometers, AERONET photometer (daytime and calibrated Raman lidar (night-time showed excellent agreement with the GPS IWV measurements.

  12. In-situ investigation of stress conditions during expansion of bare metal stents and PLLA-coated stents using the XRD sin(2)?-technique.

    Science.gov (United States)

    Kowalski, Wolfgang; Dammer, Markus; Bakczewitz, Frank; Schmitz, Klaus-Peter; Grabow, Niels; Kessler, Olaf

    2015-09-01

    Drug eluting stents (DES) consist of platform, coating and drug. The platform often is a balloon-expandable bare metal stent made of the CoCr alloy L-605 or stainless steel 316 L. The function of the coating, typically a permanent polymer, is to hold and release the drug, which should improve therapeutic outcome. Before implantation, DES are compressed (crimped) to allow implantation in the human body. During implantation, DES are expanded by balloon inflation. Crimping, as well as expansion, causes high stresses and high strains locally in the DES struts, as well as in the polymer coating. These stresses and strains are important design criteria of DES. Usually, they are calculated numerically by finite element analysis (FEA), but experimental results for validation are hardly available. In this work, the X-ray diffraction (XRD) sin(2)?-technique is applied to in-situ determination of stress conditions of bare metal L-605 stents, and Poly-(L-lactide) (PLLA) coated stents. This provides a realistic characterization of the near-surface stress state and a validation option of the numerical FEA. XRD-results from terminal stent struts of the bare metal stent show an increasing compressive load stress in tangential direction with increasing stent expansion. These findings correlate with numerical FEA results. The PLLA-coating also bears increasing compressive load stress during expansion. PMID:25974098

  13. Frequencies of X-ray induced chromosome aberrations in lymphocytes of xeroderma pigmentosum and Fanconi anemia patients estimated by Giemsa and fluorescence in situ hybridization staining techniques

    Directory of Open Access Journals (Sweden)

    Saraswathy Radha

    2000-01-01

    Full Text Available Blood lymphocytes from xeroderma pigmentosum (XP and Fanconi anemia (FA patients were assessed for their sensitivity to ionizing radiation by estimating the frequency of X-ray (1 and 2 Gy-induced chromosome aberrations (CA. The frequencies of aberrations in the whole genome were estimated in Giemsa-stained preparations of lymphocytes irradiated at G0 or G2 stages. The frequencies of translocations and dicentrics involving chromosomes 1 and 3 as well as the X-chromosome were determined in slides stained by fluorescence in situ hybridization (FISH technique. An increase in all types of CA was observed in XP and FA lymphocytes irradiated at G0 when compared to controls. The frequency of dicentrics and rings was 6 to 27% higher (at 1 and 2 Gy in XP lymphocytes and 37% higher (at 2 Gy in FA lymphocytes than in controls, while chromosome deletions were higher in irradiated (30% in 1 Gy and 72% in 2 Gy than in control XP lymphocytes and 28 to 102% higher in FA lymphocytes. In G2-irradiated lymphocytes the frequency of CA was 24 to 55% higher in XP lymphocytes than in controls. In most cases the translocation frequencies were higher than the frequencies of dicentrics (21/19.

  14. Two- and three-dimensional micro/nanostructure patterning of CdS-polymer nanocomposites with a laser interference technique and in situ synthesis

    International Nuclear Information System (INIS)

    Two- and three-dimensional (2D and 3D) micro/nanostructures of CdS-polymer nanocomposites have been successfully patterned, combining photopolymerization via a laser four-beam interference technique with in situ synthesis of CdS nanoparticles in the patterned polymer matrix. The morphology and optical properties of CdS nanoparticles in polymer matrices have been confirmed using TEM, XRD, FTIR, UV-vis absorption and fluorescence spectroscopy. Laser irradiation time and film thickness are certified to be the key factors for the control of the micro/nanostructures. With thickening film, the fabricated microstructures of CdS-polymer nanocomposites were dramatically changed from 2D rods to 3D networks which were composed of nanofibres, nanometre-scale walls and micrometre-scale rods. These kinds of 2D and 3D micro/nanostructures could be expected as potential applications in the development of nanotechnology, such as nanomedical systems, micro-fluidic chips, nanoreactors and micro/nanopurification or separation systems

  15. Phylogenetic and taxonomic analysis of Neptunitalea chrysea gen. nov., sp. nov., a member of the phylum Bacteroidetes isolated from seawater by using an in situ cultivation technique.

    Science.gov (United States)

    Yoon, Jaewoo; Kasai, Hiroaki

    2015-09-01

    A novel pale-yellow coloured bacterial strain, designated AM327(T), was isolated by using an in situ cultivation technique from seawater from the coastal zone around a shipyard located in Otsuchi Bay, Japan. The strain was found to be facultatively anaerobic, Gram-stain negative, chemoheterotrophic, non-motile and rod-shaped. Preliminary analysis based on the 16S rRNA gene sequence revealed that the novel isolate is affiliated with the family Flavobacteriaceae of the phylum Bacteroidetes and that it shows high sequence similarity (94.7 %) to Frondibacter aureus A5Q-67(T). The strain can be differentiated phenotypically from recognised members of the family Flavobacteriaceae. The DNA G+C content of strain AM327(T) was determined to be 36.2 mol%; MK-6 was identified as the major menaquinone; iso-C15:0 and iso-C17:0 3-OH were identified as the major (>10 %) cellular fatty acids. The polar lipid profile was found to consist of phosphatidylethanolamine, an unidentified aminophospholipid, an unidentified glycolipid and two unidentified lipids. From the distinct phylogenetic position and combination of genotypic and phenotypic characteristics, strain AM327(T) is considered to represent a novel genus for which the name Neptunitalea chrysea gen. nov., sp. nov. is proposed. The type strain of N. chrysea is AM327(T) (=KCTC 32989(T) = NBRC 110019(T)). PMID:26089031

  16. Effect of Sample Pre-enrichment and Characters of Food Samples on the Examination for the Salmonella by Plate Count Method and Fluorescent in-situ Hybridization Technique

    Directory of Open Access Journals (Sweden)

    R.M.U.S.K. Rathnayaka

    2011-01-01

    Full Text Available In most of the novel and traditional methods used in the examination of food samples for Salmonella, pre-enrichment of samples is used as a means of increasing the sensitivity and reliability. However, the influence of pre-enrichment of sample on some of those methods has not been studied. Furthermore, the effect of the conditions of the sample on the sensitivity of some of those methods are also not been studied. The aim of this research was to study the influence of pre-enrichment and the conditions of the samples on the detection sensitivity of one novel method Fluorescent in-situ Hybridization (FISH and one traditional culture techniques (XLT-4 agar plates. To study the influence of enrichment, 60 pork sausage samples collected from 20 different food outlets were examined for Salmonella contamination by both methods with and without pre-enrichment. To study the effect of the conditions of food, collected samples were spiked with 107 cfu mL-1 Salmonella enterica culture and examined with and without pre-enrichment. Detection sensitivity of both methods was higher in pre-enriched fresh samples as well as spiked samples. FISH method was found to be more sensitive and less affected by the conditions of food, compared to culture method.

  17. COMPARISON BETWEEN DYNAMIC MUSCULAR STABILIZATION TECHNIQUE (DMST, YOGA THERAPY AND HOT PACKS IN IMPROVING GENERAL HEALTH STATUS OF POSTURAL LOW BACK PAIN PATIENTS

    Directory of Open Access Journals (Sweden)

    Deepak Chhabra

    2015-06-01

    Full Text Available Background: Different interventions can reduce the burden of postural low back pain. For example the use of Dynamic Muscular Stabilization Technique(DMST, Yoga Therapy and Hot Packs, which aids patients by muscle strengthening and relaxation. This study is aimed to evaluate to what extent the above techniques can improve the quality of life in those who suffer from the condition. Materials and Methods: This was a randomized controlled trial. Thirty subjects (15 male and 15 females with postural low back pain (n=30 were randomly divided into three groups. Group A (DMST Group; n = 10, Group B (Yoga Group; n = 10 and Group C (Control Group; n = 10. Then General Health Status using SF – 36 QOL was assessed at 0, 1st and 2nd week. The values were compared between the three groups. Results: The Dynamic Muscular Stabilization Technique was effective in improving general health status; significant differences were found on both physical and mental health components of SF – 36 QOL. Yoga Therapy was found effective over Hot Packs. The mean improvement overall on general health status was significantly better to Dynamic Muscular Stabilization Technique. Conclusion: The Dynamic Muscular Stabilization Technique is an effective intervention improving general health status over a period of 1 month in patients who experience postural low back pain.

  18. Stabilization of compactible waste

    International Nuclear Information System (INIS)

    This report summarizes the results of series of experiments performed to determine the feasibility of stabilizing compacted or compactible waste with polymers. The need for this work arose from problems encountered at disposal sites attributed to the instability of this waste in disposal. These studies are part of an experimental program conducted at Brookhaven National Laboratory (BNL) investigating methods for the improved solidification/stabilization of DOE low-level wastes. The approach taken in this study was to perform a series of survey type experiments using various polymerization systems to find the most economical and practical method for further in-depth studies. Compactible dry bulk waste was stabilized with two different monomer systems: styrene-trimethylolpropane trimethacrylate (TMPTMA) and polyester-styrene, in laboratory-scale experiments. Stabilization was accomplished by wetting or soaking compactible waste (before or after compaction) with monomers, which were subsequently polymerized. Three stabilization methods are described. One involves the in-situ treatment of compacted waste with monomers in which a vacuum technique is used to introduce the binder into the waste. The second method involves the alternate placement and compaction of waste and binder into a disposal container. In the third method, the waste is treated before compaction by wetting the waste with the binder using a spraying technique. A series of samples stabilized at various binder-to-waste ratios were evaluated through water immersion and compression testing. Full-scale studies were conducted by stabilizing two 55-gallon drums of real compacted waste. The results of this preliminary study indicate that the integrity of compacted waste forms can be readily improved to ensure their long-term durability in disposal environments. 9 refs., 10 figs., 2 tabs

  19. Frequencies of X-ray induced chromosome aberrations in lymphocytes of xeroderma pigmentosum and Fanconi anemia patients estimated by Giemsa and fluorescence in situ hybridization staining techniques

    Scientific Electronic Library Online (English)

    Radha, Saraswathy; A.T., Natarajan.

    2000-12-01

    Full Text Available Linfócitos sanguíneos de pacientes com xeroderma pigmentosum (XP) e anemia de Fanconi (FA) foram avaliados quanto à sensibilidade à ionização radiante estimando-se a freqüência de aberrações cromossômicas (CA) induzidas por raios-X (1 e 2 Gy). As freqüências de aberrações no genoma inteiro foram est [...] imadas em preparações de linfócitos irradiados nas fases G0 e G2 coradas com Giemsa. As freqüências de translocações e dicêntricos envolvendo os cromossomos 1 e 3 e o cromossomo X foram determinadas em lâminas coradas por hibridização fluorescente in situ (FISH). Um aumento em todos os tipos de CA foi observado em linfócitos XP e FA irradiados na fase G0 quando comparados a controles. A freqüência de dicêntricos e anéis foi 6-27% maior (com 1 e 2 Gy) em linfócitos XP e 37% maior (com 2 Gy) em linfócitos FA do que em controles, enquanto que as deleções cromossômicas foram mais freqüentes em linfócitos XP irradiados (30% com 1 Gy e 72% com 2 Gy) do que em controles e 28-102% mais freqüentes em linfócitos FA. Em linfócitos irradiados na fase G2 a freqüência total de CA foi 24-55% mais elevada em linfócitos XP do que em controles. Na maior parte dos casos as freqüências de translocações foram maiores do que as freqüências de dicêntricos (21/19). Abstract in english Blood lymphocytes from xeroderma pigmentosum (XP) and Fanconi anemia (FA) patients were assessed for their sensitivity to ionizing radiation by estimating the frequency of X-ray (1 and 2 Gy)-induced chromosome aberrations (CA). The frequencies of aberrations in the whole genome were estimated in Gie [...] msa-stained preparations of lymphocytes irradiated at G0 or G2 stages. The frequencies of translocations and dicentrics involving chromosomes 1 and 3 as well as the X-chromosome were determined in slides stained by fluorescence in situ hybridization (FISH) technique. An increase in all types of CA was observed in XP and FA lymphocytes irradiated at G0 when compared to controls. The frequency of dicentrics and rings was 6 to 27% higher (at 1 and 2 Gy) in XP lymphocytes and 37% higher (at 2 Gy) in FA lymphocytes than in controls, while chromosome deletions were higher in irradiated (30% in 1 Gy and 72% in 2 Gy) than in control XP lymphocytes and 28 to 102% higher in FA lymphocytes. In G2-irradiated lymphocytes the frequency of CA was 24 to 55% higher in XP lymphocytes than in controls. In most cases the translocation frequencies were higher than the frequencies of dicentrics (21/19).

  20. In situ generated silica in natural rubber latex via the sol–gel technique and properties of the silica rubber composites

    International Nuclear Information System (INIS)

    Natural rubber (NR) composites reinforced by silica generated in situ within the NR matrix were prepared by the sol–gel process using tetraethoxysilane (TEOS) as the silica precursor. The effect of the TEOS content, water: TEOS mole ratio, reaction time and temperature on the in situ silica content formed in the NR latex were investigated. The results indicated that the suitable condition to produce a high silica content (54 parts by weight per hundred parts of rubber (phr)) in the rubbery matrix was the use of 200 phr TEOS and a water: TEOS mole ratio of 28.9:1 at room temperature for 24 h. The curing, mechanical, and thermal properties of the composite materials were also investigated. Increasing the in situ silica content increased the cure time and improved the mechanical properties of the composite. Compared to the NR vulcanizates filled with the commercial (ex situ formed) silica, the mechanical and thermal properties of the in situ silica composite material were significantly improved. Transmission electron microscopy revealed that the in situ formed silica particles were well distributed within the NR matrix, in contrast to the clumping of the ex situ formed commercial silica within the NR matrix. - Highlights: • High in situ silica content in NR latex was obtained up to 54 phr. • A good dispersion of in situ silica filling into the rubbery matrix. • Comparison of silica generated in the rubber matrix using solid, solution and latex NR substrates. • A good reinforcement effect of in situ silica was observed on the NR vulcanizate. • Sol–gel method is an alternative way to develop a novel composite material

  1. Técnica para o estudo da estabilidade de agregados do solo / Technique for studies of stability of soil aggregates

    Scientific Electronic Library Online (English)

    F., Grohmann; A., Conagin.

    Full Text Available Os autores apresentam neste trabalho uma técnica para o estudo da estabilidade de agregados do solo. Vários tipos de solo sob diferentes condições de uso foram estudados. Amostras em triplicato, de 25 g de agregados entre 7 e 4 mm, foram agitados em agitador modêlo Wagner, com 40 r.p.m., durante 1, [...] 2, 4, 8, 16, 32, 64 e 128 minutos e depois fracionadas pelo método da peneiragem lenta em água. Os agregados > 2 mm diminuíram em pêso com o aumento do tempo de agitação, aumentando por outro lodo os agregados 2 e Abstract in english This paper presents a technique for studies of stability of soil aggregates. The major soils of the State of São Paulo in different conditions of use have been examined. Triplicate samples of 25 g of soil aggregates of 7-4 mm size for each soil were shaken in a Model Wagner shaker at 40 rpm during 1 [...] , 2, 4, 8, 16, 32, 64 and 128 minutes period and were later fractioned by the wet sieving method. In general soil aggregates greater than 2 mm decreased gradually in weight with increasing period of treatment: at the some time the small size particles ( 2 mm and

  2. Determination of Nutritional Value and Digestibility and Degradability of Twigs in Four Tree Species through Chemical and in situ (Nylon Bags Techniques

    Directory of Open Access Journals (Sweden)

    H. Yosefifar

    2012-07-01

    Full Text Available This study has been conducted in order to determine nutritional value and digestibility and degradability of twigs in four tree species including Zelkova carpinifolia, Gleditchia caspica, Populus deltoids and Quercus castanaefolia through chemical and in situ techniques using 3 fistulated sheep in National Research Institute for Animal Science, IRAN. The experiment conducted based on Randomized Complete Block Design and obtained data were analyzed by software SAS and Neway. Chemical compounds (crude protein (CP, Neutral Detergent Fiber (NDF, Acid Detergent Fiber (ADF, Ether Extract (EE, Ash, Crude Fiber (CF, NFC(Non Fiber Carbohydrate, Nitrogen Free Extract (NFE and organic material (OM and degradation (dry matter and protein were determined. Amount of crude protein for 4 species are as follow Z. carpinifolia (11%, G. caspica (15.4%, P. deltoids (10.3% and Q. castanaefolia (9.5%, also amount of crude fiber in these trees are respectively 32.7, 18.6, 13.9 and 22.9%. Survey conducted on species’ degradation and on amounts of dry matter and protein which disappear after 0, 4, 8, 16, 24, 48, 72 and 96 hours. Results of degradation in dry matter and protein showed that extent of degradation has been an uptrend over time of incubation and it follows a similar trend at all times. The most degradation of dry matter (80.6% and protein (91.6% are related to G. caspica and the least degradation of dry matter (36% and protein (38.4% are related to Q. castanaefolia. Results showed that as a replacement or a complementary for alfalfa, the four considered tree species can provide some parts of food requirements by livestock through a correct programming.

  3. Rapid in situ hybridization technique using 16S rRNA segments for detecting and differentiating the closely related gram-positive organisms Bacillus polymyxa and Bacillus macerans

    Science.gov (United States)

    Jurtshuk, R. J.; Blick, M.; Bresser, J.; Fox, G. E.; Jurtshuk, P. Jr

    1992-01-01

    A rapid, sensitive, inexpensive in situ hybridization technique, using 30-mer 16S rRNA probes, can specifically differentiate two closely related Bacillus spp., B. polymyxa and B. macerans. The 16S rRNA probes were labeled with a rhodamine derivative (Texas Red), and quantitative fluorescence measurements were made on individual bacterial cells. The microscopic fields analyzed were selected by phase-contrast microscopy, and the fluorescence imaging analyses were performed on 16 to 67 individual cells. The labeled 16S rRNA probe, POL, whose sequence was a 100% match with B. polymyxa 16S rRNA but only a 60% match with B. macerans 16S rRNA, gave quantitative fluorescence ratio measurements that were 34.8-fold higher for B. polymyxa cells than for B. macerans cells. Conversely, the labeled probe, MAC, which matched B. polymyxa 16S rRNA in 86.6% of its positions and B. macerans 16S rRNA in 100% of its positions, gave quantitative fluorescence measurements that were 59.3-fold higher in B. macerans cells than in B. polymyxa cells. Control probes, whose 16S rRNA sequence segment (P-M) was present in both B. polymyxa and B. macerans as well as a panprokaryotic probe (16S), having a 100% match with all known bacteria, hybridized equally well with both organisms. These latter hybridizations generated very high fluorescence signals, but their comparative fluorescence ratios (the differences between two organisms) were low. The control paneukaryotic probe (28S), which had less than 30% identity for both B. macerans and B. polymyxa, did not hybridize with either organism.

  4. Differences in the thermal stability of REBa2Cu3O7-x (RE = Y, Nd) thin films investigated by high temperature in situ observation and melt-texture growth

    International Nuclear Information System (INIS)

    Following the increasing interest in the high thermal stability of REBa2Cu3O7-x (RE-123, RE = rare earth) thin films as seed materials, thermal stabilities of Y-123 and Nd-123 thin films were investigated by two methods: high temperature in situ microscopy and the melt growth process. A monotonic dependence of thermal stability on RE solubility in the Ba-Cu-O liquid was observed. The thermal stability of RE-123 films was found to strongly depend on the melting growth process, which is predominated by the melting rate of the RE-123 phase. Under the assumption of quasi-equilibrium, a simplified model of solute transport was suggested. The correlation between the solute inflow and outflow indicates that the melting rate of RE-123 is proportional to the growth rate of the RE2BaCuO5 (RE-211) phase and the ratio of the concentration difference between the RE-211 growth front and the RE-123 melting border. We conclude that an Nd-123 thin film is more unstable than a Y-123 thin film because of the higher melting rate, resulting from a higher growth rate of the RE-211 phase and a higher concentration difference ratio.

  5. Combination of Different In Situ Characterization Techniques and Scanning Electron Microscopy Investigations for a Comprehensive Description of the Tensile Deformation Behavior of a CrMnNi TRIP/TWIP Steel

    Science.gov (United States)

    Weidner, Anja; Biermann, Horst

    2015-08-01

    The class of low-carbon, high-alloy CrMnNi steels exhibits outstanding mechanical properties with respect to high strength and ductility due to either transformation-induced plasticity (TRIP) or twinning-induced plasticity (TWIP) effect depending on chemical composition and deformation temperature. However, the ongoing deformation mechanisms like the formation of stacking faults, martensitic phase transformation or deformation-induced twinning are overlapping and the kinetics of the microstructure evolution are quite complex. Therefore, in addition to macroscopic deformation tests and microstructural investigations by scanning electron microscopy, a combination of several in situ characterization techniques with either high lateral and/or temporal resolution as well as providing integral volume information were chosen in order to give a thoroughly and comprehensive description of the deformation behavior of CrMnNi TRIP/TWIP steels. In addition, the complementary in situ techniques like in situ nanoindentation, micro-digital image correlation, and acoustic emission measurements provide excellent possibility for description of materials behavior on a multiscale level from the submicrometer scale up to the macroscopic range. The results obtained by the complementary techniques can support the future modeling of the deformation behavior of TRIP/TWIP steels dependent on chemical composition, temperature, grain size and grain orientation.

  6. Using the charge-stabilization technique in the double ionization potential equation-of-motion calculations with dianion references.

    Science.gov (United States)

    Ku?, Tomasz; Krylov, Anna I

    2011-08-28

    The charge-stabilization method is applied to double ionization potential equation-of-motion (EOM-DIP) calculations to stabilize unstable dianion reference functions. The auto-ionizing character of the dianionic reference states spoils the numeric performance of EOM-DIP limiting applications of this method. We demonstrate that reliable excitation energies can be computed by EOM-DIP using a stabilized resonance wave function instead of the lowest energy solution corresponding to the neutral + free electron(s) state of the system. The details of charge-stabilization procedure are discussed and illustrated by examples. The choice of optimal stabilizing Coulomb potential, which is strong enough to stabilize the dianion reference, yet, minimally perturbs the target states of the neutral, is the crux of the approach. Two algorithms of choosing optimal parameters of the stabilization potential are presented. One is based on the orbital energies, and another--on the basis set dependence of the total Hartree-Fock energy of the reference. Our benchmark calculations of the singlet-triplet energy gaps in several diradicals show a remarkable improvement of the EOM-DIP accuracy in problematic cases. Overall, the excitation energies in diradicals computed using the stabilized EOM-DIP are within 0.2 eV from the reference EOM spin-flip values. PMID:21895161

  7. Elaboration of Nanocomposites Based on Poly (Ethyl Methacrylate-co-Acrylonitrile) by In Situ Polymerization Using an Algerian Bentonite. Thermal Stability and Kinetic Study

    OpenAIRE

    Djadoun S.; Kadi S.

    2012-01-01

    This contribution focuses on the synthesis and characterization of nanocomposites based on poly (ethyl methacrylate-co-acrylonitrile) (PEMAN) and different loadings of an organically modified bentonite from Algeria prepared via in situ polymerization. TEM images and X-ray patterns revealed that depending on the loading of this clay, intercalated or partially exfoliated nanocomposites were obtained. These nanocomposites showed an increase in their glass transition temperature co...

  8. The influence of Reinforcement Technique on the Calcium Chloride (CaCl2 & Granulated Blast Furnace Slag (GBFS Stabilized Marine Clay for Foundation Soilbeds

    Directory of Open Access Journals (Sweden)

    D. Koteswara Rao,

    2011-03-01

    Full Text Available In general, the soils which are existing in the coastal corridors are Soft Marine Clays formed by the deposits and generally weak and possesses high deformation values in nature. It is essential to study the various techniques for the improvement of marine clays, especially in case of infra-structure development. The present study dealswith the stabilization of marine clay using GBFS and calcium chloride and also the effect of reinforcement technique for improving the load carrying capacity of the foundation soil beds.

  9. Optimal Power Flow Based Global Voltage Stability Analysis Using Network Equivalencing Technique: A Case Study of Widespread Sub-Grid

    OpenAIRE

    Palukuru NAGENDRA; Sunita Halder nee DEY; Subrata PAUL

    2010-01-01

    The objective this paper is to develop a methodology to assess the voltage stability considering optimal operating criteria using the concept of equivalencing the multi-bus power system to a two-bus network model and by studying the necessary parameters of the equivalent system. There by, a generalized global voltage stability indicator being developed, it has been applied to a typical longitudinal power supply (LPS) system and a robust practical 203-bus Indian Eastern Grid system. Simulation...

  10. Global Voltage Stability Analysis of a Power System Using Network Equivalencing Technique in the presence of TCSC

    OpenAIRE

    Sunita Halder nee DEY; Palukuru NAGENDRA; Subrata PAUL

    2010-01-01

    This paper presents a methodology for assessing the voltage stability using the concept of equivalencing the multi-bus power system to a two-bus network model and by studying the necessary parameters of the equivalent system. There by, a generalized global voltage stability indicator being developed, it has been applied to a robust practical 203-bus Indian Eastern Grid system. Simulation results indicate that this optimal power flow (OPF) based network equivalent approach is promising to asse...

  11. A size-dependent sodium storage mechanism in Li4Ti5O12 investigated by a novel characterization technique combining in situ X-ray diffraction and chemical sodiation.

    Science.gov (United States)

    Yu, Xiqian; Pan, Huilin; Wan, Wang; Ma, Chao; Bai, Jianming; Meng, Qingping; Ehrlich, Steven N; Hu, Yong-Sheng; Yang, Xiao-Qing

    2013-10-01

    A novel characterization technique using the combination of chemical sodiation and synchrotron based in situ X-ray diffraction (XRD) has been detailed illustrated. The power of this novel technique was demonstrated in elucidating the structure evolution of Li4Ti5O12 upon sodium insertion. The sodium insertion behavior into Li4Ti5O12 is strongly size dependent. A solid solution reaction behavior in a wide range has been revealed during sodium insertion into the nanosized Li4Ti5O12 (~44 nm), which is quite different from the well-known two-phase reaction of Li4Ti5O12/Li7Ti5O12 system during lithium insertion, and also has not been fully addressed in the literature so far. On the basis of this in situ experiment, the apparent Na(+) ion diffusion coefficient (DNa+) of Li4Ti5O12 was estimated in the magnitude of 10(-16) cm(2) s(-1), close to the values estimated by electrochemical method, but 5 order of magnitudes smaller than the Li(+) ion diffusion coefficient (D(Li+) ~10(-11) cm(2) s(-1)), indicating a sluggish Na(+) ion diffusion kinetics in Li4Ti5O12 comparing with that of Li(+) ion. Nanosizing the Li4Ti5O12 will be critical to make it a suitable anode material for sodium-ion batteries. The application of this novel in situ chemical sodiation method reported in this work provides a facile way and a new opportunity for in situ structure investigations of various sodium-ion battery materials and other systems. PMID:24053585

  12. An Assessment of the Stability and the Potential for In-Situ Synthesis of Regulated Organic Compounds in High Level Radioactive Waste Stored at Hanford, Richland, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Wiemers, K.D.; Babad, H.; Hallen, R.T.; Jackson, L.P.; Lerchen, M.E.

    1999-01-04

    The stability assessment examined 269 non-detected regulated compounds, first seeking literature references of the stability of the compounds, then evaluating each compound based upon the presence of functional groups using professional judgment. Compounds that could potentially survive for significant periods in the tanks (>1 year) were designated as stable. Most of the functional groups associated with the regulated organic compounds were considered unstable under tank waste conditions. The general exceptions with respect to functional group stability are some simple substituted aromatic and polycyclic aromatic compounds that resist oxidation and the multiple substituted aliphatic and aromatic halides that hydrolyze or dehydrohalogenate slowly under tank waste conditions. One-hundred and eighty-one (181) regulated, organic compounds were determined as likely unstable in the tank waste environment.

  13. An Assessment of the Stability and the Potential for In-Situ Synthesis of Regulated Organic Compounds in High Level Radioactive Waste Stored at Hanford, Richland, Washington

    International Nuclear Information System (INIS)

    The stability assessment examined 269 non-detected regulated compounds, first seeking literature references of the stability of the compounds, then evaluating each compound based upon the presence of functional groups using professional judgment. Compounds that could potentially survive for significant periods in the tanks (>1 year) were designated as stable. Most of the functional groups associated with the regulated organic compounds were considered unstable under tank waste conditions. The general exceptions with respect to functional group stability are some simple substituted aromatic and polycyclic aromatic compounds that resist oxidation and the multiple substituted aliphatic and aromatic halides that hydrolyze or dehydrohalogenate slowly under tank waste conditions. One-hundred and eighty-one (181) regulated, organic compounds were determined as likely unstable in the tank waste environment

  14. In Situ Studies of Fe4+ Stability in ?-Li3Fe2(PO4)3 Cathodes for Li Ion Batteries

    DEFF Research Database (Denmark)

    Christiansen, Ane Sælland; Johnsen, Rune E.

    2015-01-01

    In commercial Fe-based batteries the Fe2+/Fe3+ oxidation states are used, however by also utilizing the Fe4+ oxidation state, intercalation of up to two Li ions per Fe ion could be possible. In this study, we investigate whether Fe4+ can be formed and stabilized in ?-Li3Fe2(PO4)3. The work includes in situ synchrotron X-ray powder diffraction studies (XRPD) during charging of ?-Li3Fe2(PO4)3 up to 5.0 V vs. Li/Li+. A novel capillary-based micro battery cell for in situ XRPD has been designed for this. During charge, a plateau at 4.5 V was found and a small contraction in volume was observed, indicating some Li ion extraction. The volume change of the rhombohedral unit cell is anisotropic, with a decrease in the a parameter and an increase in the c parameter during the Li ion extraction. Unfortunately, no increased discharge capacity was observed and Mössbauer spectroscopy showed no evidence of Fe4+ formation. Oxidation of the organic electrolyte is inevitable at 4.5 V but this alone cannot explain the volume change. Instead, a reversible oxygen redox process (O2? ? O?) could possibly explain and charge compensate for the reversible extraction of lithium ions from ?-Li3Fe2(PO4)3.

  15. Direct in situ RT-PCR

    OpenAIRE

    Merighi, Adalberto; GAMBINO, Graziana; Lossi, Laura; SALIO, Chiara

    2011-01-01

    In situ polymerase chain reaction (PCR) is a histological technique that exploits the advantages of PCR for detection of mRNA directly in tissue sections. It somehow conjugates together PCR and in situ hybridization that is more traditionally employed for mRNA localization in cell organelles, intact cells, or tissue sections. This chapter describes the application of in situ PCR for neuropeptide mRNA localization. We provide here a detailed protocol for direct in situ reverse transcription (R...

  16. Development and application of compact denuder sampling techniques with in situ derivatization followed by gas chromatography-mass spectrometry for halogen speciation in volcanic plumes

    Science.gov (United States)

    Rüdiger, Julian; Bobrowski, Nicole; Hoffmann, Thorsten

    2015-04-01

    Volcanoes are a large source for several reactive atmospheric trace gases including sulphur and halogen containing species. The detailed knowledge of volcanic plume chemistry can give insights into subsurface processes and can be considered as a useful geochemical tool for monitoring of volcanic activity, especially halogen to sulphur ratios (e.g. Bobrowski and Giuffrida, 2012; Donovan et al., 2014). The reactive bromine species bromine monoxide (BrO) is of particular interest, because BrO as well as SO2 are readily measurable by UV spectrometers at a safe distance. Furthermore it is formed in the plume by a multiphase reaction mechanism under depletion of ozone in the plume. The abundance of BrO changes as a function of the reaction time and therefore distance from the vent as well as the spatial position in the plume. Due to the lack of analytical approaches for the accurate speciation of certain halogens (HBr, Br2, Br, BrCl, HOBr etc.) there are still uncertainties about the magnitude of volcanic halogen emissions and in particular their specificationtheir species and therefore also in the understanding of the bromine chemistry in volcanic plumes (Bobrowski et al., 2007). In this study, the first application of a 1,3,5-trimethoxybenzene (1,3,5-TMB)-coated gas diffusion denuder (Huang and Hoffmann, 2008) on volcanic gases proved to be suitable to collect selectively gaseous bromine species with oxidation states of +1 or 0 (Br2 and BrO(H)), while being ignorant to HBr (OS -1). The reaction of 1,3,5-TMB with bromine gives 1-bromo-2,4,6-trimethoxybenzene (1-bromo-2,4,6-TMB) - other halogens give corresponding products. The diffusion denuder technique allows sampling of gaseous compounds exclusively without collecting particulate matter. Choosing a flow rate of 500 mL-min-1 and a denuder length of 0.5 m a nearly quantitative collection efficiency was achieved. Solvent elution of the derivatized analytes and subsequent analysis with gas chromatography-mass spectrometry gives a limit of detection below 1 ng of bromine. The method was applied on volcanic gas plumes at Mt. Etna and Mt. Stromboli in Italy in July 2014 and on fumarolic gas emissions at Mt. Lastarria in Chile in November 2014. The results show significant amounts of the concerning bromine species (lower ppb range). Comprehensive data evaluation and comparison with results of impinger extraction with NaOH solution as well as chamber experiments are still in progress. References Bobrowski, N. and G. Giuffrida: Bromine monoxide / sulphur dioxide ratios in relation to volcanological observations at Mt. Etna 2006-2009. Solid Earth, 3, 433-445, 2012 Bobrowski, N., R. von Glasow, A. Aiuppa, S. Inguaggiato, I. Louban, O. W. Ibrahim and U. Platt: Reactive halogen chemistry in volcanic plumes. J. Geophys. Res., 112, 2007 Donovan A., V. Tsanev, C. Oppenheimer and M. Edmonds: Reactive halogens (BrO and OClO) detected in the plume of Soufrière Hills Volcano during an eruption hiatus. Geochem. Geophys. Geosyst., 15, 3346-3363, 2014 Huang, R.-J. and T. Hoffmann: A denuder-impinger system with in situ derivatization followed by gas chromatography-mass spectrometry for the determination of gaseous iodine-containing halogen species. Journal of Chromatography A, 1210, 135-141, 2008

  17. Voltage stability evaluation facing small disturbances by means of the modal analysis technique; Evaluacion de la estabilidad de voltaje ante disturbios pequenos mediante la tecnica de analisis modal

    Energy Technology Data Exchange (ETDEWEB)

    Leon Rodriguez, Daniel

    2000-12-15

    The economic development of the countries has taken implicit a growing industrialization the one which, joined to those every time bigger resident's necessities, it has caused a constant and progressive increment in the electric power demand. However, in the last years the growth of the electric network of these systems has been more and more limited for diverse such factors as the ecology and the economy, as well as for the social and political costs that implies each new construction in the system. With the presence of these restrictions the electric systems in many cases, have been forced to satisfy the increments in the demand making a more exhaustive use of the infrastructure that they have available and the incorporation of only a few new system elements or constructions. These aspects have caused such systems to operate with more limited security margins and that their stability has to be analyzed in a reliable and precise way. Taking into account the previously mentioned aspects, as the electric systems have had the necessity of operating under forced conditions to satisfy the load demand, voltage stability problems have been presented with more frequency causing serious disturbances and in some cases, total blackouts. With these problems, the voltage stability analysis has taken bigger importance in the studies that the electric utilities carry out. This issue has caused that bigger resources are dedicated for the investigation of this phenomenon with the purpose of understanding and developing tools that allow studying it in a more complete and more truthful way. Modal analysis is one of the most recent and popular steady techniques the one that, from its appearance has had a great peak due to the valuable and quick information that provides, besides its implementation easiness and the little effort computational that it requires. In this work is carried out the voltage stability evaluation of a real electric system applying in a combined way the modal analysis technique with other conventional techniques as the curves P-V and V-Q. It also illustrated the way in that the different information obtained of these techniques is supplemented to achieve a more complete and more representative voltage stability study. Besides analyzing the voltage stability for the normal operation conditions (base case), also are evaluated three different reactive compensation alternatives with the object of improving the margin or distance to the system voltage instability. The results obtained with each one of the compensation options are compared to each other and commented for finally, to propose the alternative that presents the biggest advantages from the voltage stability point of view. The selection of the most appropriate places to locate the reactive compensation is carried out being based on the bus participation factors by the modal analysis for the base case. Finally, taking into account the tools and the procedures used in this work to carry out the voltage stability analysis, one of the main purposes consists on proposing a methodology that allows indicating certain guidelines that help carry out voltage stability studies in a quicker and simpler way. [Spanish] El desarrollo economico de los paises ha llevado implicita una creciente industrializacion la cual, aunada a las cada vez mayores necesidades de sus pobladores, ha provocado un constante y progresivo incremento en la demanda de energia electrica. Sin embargo, en los ultimos anos el crecimiento de la red electrica de estos sistemas se ha visto cada vez mas limitado por diversos factores tales como la ecologia, la economia y por los costos sociales y politicos que cada nueva obra implica. Ante la presencia de estas restricciones los sistemas electricos en muchos casos, se han visto obligados a satisfacer los incrementos en la demanda haciendo un uso mas exhaustivo de la infraestructura que tienen disponible y la incorporacion de solo unas cuantas obras nuevas. Estos aspectos han provocado que dichos sistemas operen con margenes de seguridad mas limitados y qu

  18. Thermal stability in the blended lithium manganese oxide - Lithium nickel cobalt manganese oxide cathode materials: An in situ time-resolved X-Ray diffraction and mass spectroscopy study

    Science.gov (United States)

    Hu, Enyuan; Bak, Seong Min; Senanayake, Sanjaya D.; Yang, Xiao-Qing; Nam, Kyung-Wan; Zhang, Lulu; Shao, Minhua

    2015-03-01

    Thermal stabilities of a series of blended LiMn2O4 (LMO)-LiNi1/3Co1/3Mn1/3O2 (NCM) cathode materials with different weight ratios were studied by in situ time-resolved X-ray diffraction (XRD) combined with mass spectroscopy in the temperature range of 25 °C-580 °C under helium atmosphere. Upon heating, the electrochemically delithiated LMO changed into Mn3O4 phase at around 250 °C. Formation of MnO with rock-salt structure started at 520 °C. This observation is in contrast to the previous report for chemically delithiated LMO in air, in which a process of ?-MnO2 transforming to ?-MnO2 was observed. Oxygen peak was not observed in all cases, presumably as a result of either consumption by the carbon or detection limit. CO2 profile correlates well with the phase transition and indirectly suggests the oxygen release of the cathode. Introducing NCM into LMO has two effects: first, it makes the high temperature rock-salt phase formation more complicated with more peaks in CO2 profile due to different MO (M = Ni, Mn, Co) phases; secondly, the onset temperature of CO2 release is lowered, implying lowered oxygen release temperature. Upon heating, XRD patterns indicate the NCM part reacts first, followed by the LMO part. This confirms the better thermal stability of LMO over NCM.

  19. Thermal stability of AlCoCrCuFeNi high entropy alloy thin films studied by in-situ XRD analysis

    OpenAIRE

    Dolique, Vincent; Thomann, Anne-Lise; Brault, Pascal; Tessier, Y; Gillon, Pascale

    2010-01-01

    High entropy alloys (HEAs), containing five to thirteen metallic elements, with a concentration in the range of 5 to 35% for each element, exhibit very interesting properties (mechanical, tribological, formability, magnetism...). Their high mixing entropy promotes the formation of random solid solutions, amorphous alloys or nanocrystallized structures. Bulk pieces of these alloys are known to be stable at relatively high temperature (until 800 °C). We study the stability of AlCoCrCuFeNi thin ...

  20. Continuous sagittal radiological evaluation of stair-climbing in cruciate-retaining and posterior-stabilized total knee arthroplasties using image-matching techniques.

    Science.gov (United States)

    Hamai, Satoshi; Okazaki, Ken; Shimoto, Takeshi; Nakahara, Hiroyuki; Higaki, Hidehiko; Iwamoto, Yukihide

    2015-05-01

    In this study, we evaluated the in vivo kinematics of stair-climbing after posterior stabilized (PS) and cruciate retaining (CR) total knee arthroplasty (TKA) using radiographic-based image-matching techniques. Mid-flexion anteroposterior stability was demonstrated in all knees after CR TKA. However, paradoxical femoral translation at low flexion angles was seen in both designs. The post-cam mechanism did not function after PS TKA. Larger posterior tibial slope in PS TKA was linked to forward sliding of the femur at mid-flexion and unintended anterior tibial post impingement at knee extension. CR TKA is more sagittally stable in mid-flexion during stair climbing and attention must be given to minimize posterior tibial slope when using late cam-post engaging PS TKA designs. PMID:25618811

  1. Knee stability, athletic performance and sport-specific tasks in non-professional soccer players after ACL reconstruction: comparing trans-tibial and antero-medial portal techniques

    Science.gov (United States)

    Tudisco, Cosimo; Bisicchia, Salvatore; Cosentino, Andrea; Chiozzi, Federica; Piva, Massimo

    2015-01-01

    Summary Background a wrong position of bone tunnels, in particular on the femur, is one of the most frequent causes of a failed anterior cruciate ligament (ACL) reconstruction. Several studies demonstrated that drilling the femoral tunnel through the antero-medial portal (AMP) allows a more anatomical placement on the lateral femoral condyle and higher knee stability, compared to trans-tibial (TT) technique. The aim of this study was to retrospectively evaluate two groups of soccer players operated on for ACL reconstruction according to either one of these two techniques. Methods two groups of non-professional soccer players operated on for a single bundle ACL reconstruction with hamstrings autograft using either a TT (20 patients) or an AMP (23 patients) technique were retrospectively evaluated with KT-1000 arthrometer, manual pivot shift test, isokinetic test, the incremental treadmill-running test, athletic and sport specific tasks, and knee scores (IKDC, Lysholm and KOOS). Results the AMP group showed better results at pivot shift test and KOOS, but lower flexion angles at single leg squat test. There were no differences in all the other considered outcomes. Conclusions the better rotational stability of the knee achieved in AMP group did not lead to significantly better clinical and functional results in our patients. Level of evidence III. Treatment study Case-control study. PMID:26605191

  2. Environmental stability of solution processed Al-doped ZnO naoparticulate thin films using surface modification technique

    Energy Technology Data Exchange (ETDEWEB)

    Vunnam, Swathi, E-mail: swathivunnam@gmail.com [Program of Nanoscience and Nanoengineering, South Dakota School of Mines and Technology, Rapid City, SD 57701 (United States); Ankireddy, Krishnamraju; Kellar, Jon [Program of Materials Engineering and Science, South Dakota School of Mines and Technology, Rapid City, SD 57701 (United States); Cross, William, E-mail: William.Cross@sdsmt.edu [Program of Materials Engineering and Science, South Dakota School of Mines and Technology, Rapid City, SD 57701 (United States)

    2014-12-15

    Graphical abstract: - Highlights: • AZO nanoparticulate films were deposited using ultrasonic spray deposition. • Functionalization of solution processed AZO thin films was carried out. • Contact angles and QNM AFM results confirmed the existence of molecular layers. • Environmental stability of AZO films greatly increased with surface modification. - Abstract: The environmental stability of solution processed Al-doped ZnO (AZO) thin films was enhanced by functionalizing the film surface with a thin self-assembled molecular layer. Functionalization of AZO films was performed using two types of molecules having identical 12-carbon alkyl chain termination but different functional groups: dodecanethiol (DDT) and dodecanoic acid (DDA). Surface modified AZO films were examined using electrical resistivity measurements, contact angle measurements and quantitative nanomechanical property mapping atomic force microscopy. The hydrophobic layer inhibits the penetration of oxygen and water into the AZO's grain boundaries thus significantly increasing the environmental stability over unmodified AZO. Surface modified AZO films using DDT exhibited lower electrical resistivity compared to DDA functionalized AZO films. Our study demonstrates a new approach for improving the physical properties of oxide based nanoparticulate films for device applications.

  3. Dimensional Stability of Polyether, Alginate, and Silicone Impression Materials After Disinfection With 2% Sanosil Through the Immersion Technique

    Directory of Open Access Journals (Sweden)

    Izadi

    2014-10-01

    Full Text Available Background To prevent diseases transmission, infection control in dental offices without reducing the accuracy and dimensional stability of impression materials is very important. Objectives The aim of this study was to evaluate the effects of Sanosil disinfectants on the dimensional stability of some usual impression materials. Materials and Methods Three types of impression material, namely, alginate, condensational silicone, and polyether, were used in this study. Impressions were obtained from the master steel model. Fifteen impressions of each material (control group were immersed in water for ten minutes and impressions of study groups were disinfected by immersion in 2% Sanosil for ten minutes. Then impressions were poured by type III gypsum according to the manufacture's instruction. Dimensions of casts in the two anterior dimensions, i.e. interval between the anterior abutments and interval between anterior-posterior abutments, were recorded by a digital caliper with the accuracy of 0.01 mm. Data were analyzed with SPSS through two-way ANOVA test. Results The results showed that there was no significant difference in the mean dimension of casts prepared by different impression materials in anterior and anterior-posterior dimensions in comparison to the original model after disinfection with Sanosil. Conclusions The study revealed that disinfection with 2% Sanosil has no significant effect on casts dimensions of alginate, silicone, and polyether impression and dimensional stability is maintained.

  4. Environmental stability of solution processed Al-doped ZnO naoparticulate thin films using surface modification technique

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • AZO nanoparticulate films were deposited using ultrasonic spray deposition. • Functionalization of solution processed AZO thin films was carried out. • Contact angles and QNM AFM results confirmed the existence of molecular layers. • Environmental stability of AZO films greatly increased with surface modification. - Abstract: The environmental stability of solution processed Al-doped ZnO (AZO) thin films was enhanced by functionalizing the film surface with a thin self-assembled molecular layer. Functionalization of AZO films was performed using two types of molecules having identical 12-carbon alkyl chain termination but different functional groups: dodecanethiol (DDT) and dodecanoic acid (DDA). Surface modified AZO films were examined using electrical resistivity measurements, contact angle measurements and quantitative nanomechanical property mapping atomic force microscopy. The hydrophobic layer inhibits the penetration of oxygen and water into the AZO's grain boundaries thus significantly increasing the environmental stability over unmodified AZO. Surface modified AZO films using DDT exhibited lower electrical resistivity compared to DDA functionalized AZO films. Our study demonstrates a new approach for improving the physical properties of oxide based nanoparticulate films for device applications

  5. Measuring Level Alignment at the Metal–Molecule Interface by In Situ Electrochemical 13C NMR

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ying; Zelakiewicz, Brian S.; Allison, Thomas C.; Tong, Yu ye J.

    2015-03-16

    A new technique to measure energy-level alignment at a metal–molecule interface between the Fermi level of the metal and the frontier orbitals of the molecule is proposed and experimentally demonstrated. The method, which combines the electrochemistry of organo-ligand-stabilized Au nanoparticles with 13C NMR spectroscopy (i.e. in situ electrochemical NMR), enables measuring both occupied and unoccupied states.

  6. Dramatically improved RNA in situ hybridization signals using LNA-modified probes

    DEFF Research Database (Denmark)

    Thomsen, Rune; Nielsen, Peter Stein; Jensen, Torben Heick

    2005-01-01

    In situ detection of RNA by hybridization with complementary probes is a powerful technique. Probe design is a critical parameter in successful target detection. We have evaluated the efficiency of fluorescent DNA oligonucleotides modified to contain locked nucleic acid (LNA) residues. This increases the thermal stability of hybrids formed with RNA. The LNA-based probes detect specific RNAs in fixed yeast cells with an efficiency far better than conventional DNA oligonucleotide probes of the sam...

  7. DNA Mimics for the Rapid Identification of Microorganisms by Fluorescence in situ Hybridization (FISH)

    OpenAIRE

    Vieira, Maria J; Charles William Keevil; Tatiana Jardim; Carina Almeida; Nuno F. Azevedo; Laura Cerqueira

    2008-01-01

    Fluorescence in situ hybridization (FISH) is a well-established technique that is used for a variety of purposes, ranging from pathogen detection in clinical diagnostics to the determination of chromosomal stability in stem cell research. The key step of FISH involves the detection of a nucleic acid region and as such, DNA molecules have typically been used to probe for the sequences of interest. However, since the turn of the century, an increasing number of laboratories have ...

  8. A review of joining techniques for SiCf/SiC composites for first wall applications

    International Nuclear Information System (INIS)

    Many methods for joining monolithic and composite silicon carbide are available. Three techniques are candidates for use in fusion energy systems: in-situ displacement reactions, pre-ceramic polymer adhesives, and reaction bonding. None of the methods are currently developed enough to satisfy all of the criteria required, i.e., low temperature fabrication, high strength, and radiation stability. 58 refs

  9. Detecting In Situ Copepod Diet Diversity Using Molecular Technique: Development of a Copepod/Symbiotic Ciliate-Excluding Eukaryote-Inclusive PCR Protocol

    OpenAIRE

    Hu, Simin; Guo, Zhiling; Li, Tao; Carpenter, Edward J; Liu, Sheng; Lin, Senjie

    2014-01-01

    Knowledge of in situ copepod diet diversity is crucial for accurately describing pelagic food web structure but is challenging to achieve due to lack of an easily applicable methodology. To enable analysis with whole copepod-derived DNAs, we developed a copepod-excluding 18S rDNA-based PCR protocol. Although it is effective in depressing amplification of copepod 18S rDNA, its applicability to detect diverse eukaryotes in both mono- and mixed-species has not been demonstrated. Besides, the pro...

  10. COMET: a planned airborne mission to simultaneously measure CO2 and CH4 columns using airborne remote sensing and in-situ techniques

    Science.gov (United States)

    Fix, A.; Amediek, A.; Büdenbender, C.; Ehret, G.; Wirth, M.; Quatrevalet, M.; Rapp, M.; Gerilowski, K.; Bovensmann, H.; Gerbig, C.; Pfeilsticker, K.; Zöger, M.; Giez, A.

    2013-12-01

    To better predict future trends in the cycles of the most important anthropogenic greenhouse gases, CO2 and CH4, there is a need to measure and understand their distribution and variation on various scales. To address these requirements it is envisaged to deploy a suite of state-of-the-art airborne instruments that will be capable to simultaneously measure the column averaged dry-air mixing ratios (XGHG) of both greenhouse gases along the flight path. As the measurement platform serves the research aircraft HALO, a modified Gulfstream G550, operated by DLR. This activity is dubbed CoMet (CO2 and Methane Mission). The instrument package of CoMet will consist of active and passive remote sensors as well as in-situ instruments to complement the column measurements by highly-resolved profile information. As an active remote sensing instrument CHARM-F, the integrated-path differential absorption lidar currently under development at DLR, will provide both, XCO2 and XCH4, below flight altitude. The lidar instrument will be complemented by MAMAP which is a NIR/SWIR absorption spectrometer developed by University of Bremen and which is also capable to derive XCH4 and XCO2. As an additional passive instrument, mini-DOAS operated by University of Heidelberg will contribute with additional context information about the investigated air masses. In order to compare the remote sensing instruments with integrated profile information, in-situ instrumentation is indispensable. The in-situ package will therefore comprise wavelength-scanned Cavity-Ring-Down Spectroscopy (CRDS) for the detection of CO2, CH4, CO and H2O and a flask sampler for collection of atmospheric samples and subsequent laboratory analysis. Furthermore, the BAsic HALO Measurement And Sensor System (BAHAMAS) will provide an accurate set of meteorological and aircraft state parameters for each scientific flight. Within the frame of the first CoMet mission scheduled for the 2015 timeframe it is planned to concentrate on small to sub-continental scale variations of the greenhouse gases. This does not only allow to identify local emission sources of GHGs, but also opens up the opportunity to use important remote sensing and in-situ data information for the inverse modeling approach for regional budgeting. CoMet is also targeting at providing a validation platform of future spaceborne GHG missions in particular the upcoming French-German methane mission MERLIN. CHARM-F was devised as an airborne demonstrator for MERLIN, and, as such will be a key instrument for MERLIN validation.

  11. Exponential stability of delayed multi-group model with reaction-diffusion and multiple dispersal based on Razumikhin technique and graph theory

    Science.gov (United States)

    Li, Wenxue; Zhang, Xiaoqing; Zhang, Chunmei

    2015-10-01

    In this paper, we investigate the delayed multi-group model with reaction-diffusion and multi-dispersal. In this multi-group model, each single group model and dispersal schema among multiple groups are affected by time delays and reaction-diffusion. The main method is the combining of Razumikhin technique and graph theory. Based on the main method, several stability criteria are presented, including the Razumikhin-type theorem, the Lyapunov-type theorem and a sufficient criterion in the form of coefficients. Finally, a numerical example is provided to illustrate the effectiveness of the results developed.

  12. Trace Metals in Groundwater and Vadose Zone Calcite: In Situ Containment and Stabilization of Strontium-90 and Other Divalent Metals and Radionuclides at Arid Western DOE Sites: Final Report for Award Number DE-FG07-02ER63486 to the University of Idaho (RW Smith) Environmental Management Science Program Project Number 87016

    International Nuclear Information System (INIS)

    Radionuclide and metal contaminants are present in the vadose zone and groundwater throughout the U.S. Department of Energy (DOE) energy research and weapons complex. In situ containment and stabilization of these contaminants represents a cost-effective treatment strategy that minimizes workers exposure to hazardous substances, does not require removal or transport of contaminants, and generally does not generate a secondary waste stream. We have investigated an in situ bioremediation approach that immobilizes radionuclides or contaminant metals (e.g., strontium-90) by their microbially facilitated co-precipitation with calcium carbonate in groundwater and vadose zone systems. Calcite, a common mineral in many aquifers and vadose zones in the arid west, can incorporate divalent metals such as strontium, cadmium, lead, and cobalt into its crystal structure by the formation of a solid solution. Collaborative research undertaken by the Idaho National Laboratory (INL), University of Idaho, and University of Toronto as part of this Environmental Management Science Program project has focused on in situ microbially-catalyzed urea hydrolysis, which results in an increase in pH, carbonate alkalinity, ammonium, calcite precipitation, and co-precipitation of divalent cations. In calcite-saturated aquifers, microbially facilitated co-precipitation with calcium carbonate represents a potential long-term contaminant sequestration mechanism. Key results of the project include: **Demonstrating the linkage between urea hydrolysis and calcite precipitation in field and laboratory experiments **Observing strontium incorporation into calcite precipitate by urea hydrolyzers with higher distribution coefficient than in abiotic **Developing and applying molecular methods for characterizing microbial urease activity in groundwater including a quantitative PCR method for enumerating ureolytic bacteria **Applying the suite of developed molecular methods to assess the feasibility of the proposed bioremediation technique at a contaminated site located within the 100-N area of the Hanford, Washington site **Assessing the role of nitrification on the persistence of precipitated calcite by modifying primers for identification of the amoA gene region of various ammonia oxidizing bacteria (AOB) for characterizing AOB in the field

  13. Trace Metals in Groundwater and Vadose Zone Calcite: In Situ Containment and Stabilization of Stronthium-90 and Other Divalent Metals and Radionuclides at Arid Western DOE Sites: Final Report for Award Number DE-FG07-02ER63486 to the University of Idaho (RW Smith) Environmental Management Science Program Project Number 87016

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Robert W.; Fujita, Yoshiko

    2007-11-07

    Radionuclide and metal contaminants are present in the vadose zone and groundwater throughout the U.S. Department of Energy (DOE) energy research and weapons complex. In situ containment and stabilization of these contaminants represents a cost-effective treatment strategy that minimizes workers’ exposure to hazardous substances, does not require removal or transport of contaminants, and generally does not generate a secondary waste stream. We have investigated an in situ bioremediation approach that immobilizes radionuclides or contaminant metals (e.g., strontium-90) by their microbially facilitated co-precipitation with calcium carbonate in groundwater and vadose zone systems. Calcite, a common mineral in many aquifers and vadose zones in the arid west, can incorporate divalent metals such as strontium, cadmium, lead, and cobalt into its crystal structure by the formation of a solid solution. Collaborative research undertaken by the Idaho National Laboratory (INL), University of Idaho, and University of Toronto as part of this Environmental Management Science Program project has focused on in situ microbially-catalyzed urea hydrolysis, which results in an increase in pH, carbonate alkalinity, ammonium, calcite precipitation, and co-precipitation of divalent cations. In calcite-saturated aquifers, microbially facilitated co-precipitation with calcium carbonate represents a potential long-term contaminant sequestration mechanism. Key results of the project include: **Demonstrating the linkage between urea hydrolysis and calcite precipitation in field and laboratory experiments **Observing strontium incorporation into calcite precipitate by urea hydrolyzers with higher distribution coefficient than in abiotic **Developing and applying molecular methods for characterizing microbial urease activity in groundwater including a quantitative PCR method for enumerating ureolytic bacteria **Applying the suite of developed molecular methods to assess the feasibility of the proposed bioremediation technique at a contaminated site located within the 100-N area of the Hanford, Washington site **Assessing the role of nitrification on the persistence of precipitated calcite by modifying primers for identification of the amoA gene region of various ammonia oxidizing bacteria (AOB) for characterizing AOB in the field

  14. Aminolysis of polyethylene terephthalate surface along with in situ synthesis and stabilizing ZnO nanoparticles using triethanolamine optimized with response surface methodology.

    Science.gov (United States)

    Poortavasoly, Hajar; Montazer, Majid; Harifi, Tina

    2016-01-01

    This research concerned the simultaneous polyester surface modification and synthesis of zinc oxide nano-reactors to develop durable photo-bio-active fabric with variable hydrophobicity/hydrophilicity under sunlight. For this purpose, triethanolamine (TEA) was applied as a stabilizer and pH adjusting chemical for the aminolysis of polyester surface and enhancing the surface reactivity along with synthesis and deposition of ZnO nanoparticles on the fabric. Therefore, TEA played a crucial role in providing the alkaline condition for the preparation of zinc oxide nanoparticles and acting as stabilizer controlling the size of the prepared nanoparticles. The stain-photodegradability regarded as self-cleaning efficiency, wettability and weight change under the process was optimized based on zinc acetate and TEA concentrations, using central composite design (CCD). Findings also suggested the potential of the prepared fabric in inhibiting Staphylococcus aureus and Escherichia coli bacteria growth with greater than 99.99% antibacterial efficiency. Besides, the proposed treatment had no detrimental effect on tensile strength and hand feeling of the polyester fabric. PMID:26478337

  15. In situ optical absorption spectroscopy, incandencence, and light-scattering characterization of single-wall carbon nanotube synthesis by the laser vaporization technique

    Science.gov (United States)

    Puretzky, Alexander A.; Geohegan, David B.; Schittenhelm, C. H.

    2003-07-01

    In this paper we discuss three optical methods for in situ characterization of single wall carbon nanotube (SWNT) growth by laser vaporization at elevated temperatures: optical absorption spectroscopy, optical incandescence, and light scattering. Optical absorption spectroscopy was successfully used to estimate the size of carbon nanoparticles and to monitor the atomic metal catalyst in the propagating laser ablation plume. These measurements indicate that the aggregation rate of carbon nanoparticles increases rapidly at lower oven processing temperatures. The second method, incandescence, was applied to measure the particle temperature within the propagating plume at different times after ablation. The third approach, imaging of the plume using Rayleigh scattered light, was used to monitor the ejected material inside the hot furnace as well as to observe the plume when it exits the furnace, i.e., in the cold zone of a quartz tube reactor. We demonstrated that Rayleigh scattering imaging combined with TEM analysis of the produced material was very useful for controlling the length of SWNTs and estimation of the growth rates. A general picture of SWNT growth by laser vaporization based on in situ diagnostics of ejected material at different times after ablation is discussed.

  16. An experimental study of the (Ti–6Al–4V)–xH phase diagram using in situ synchrotron XRD and TGA/DSC techniques

    International Nuclear Information System (INIS)

    Hydrogen has been investigated for decades as a temporary alloying element to refine the microstructure of Ti–6Al–4V, and is now being used in a novel powder metallurgy method known as “hydrogen sintering and phase transformation”. Pseudo-binary phase diagrams of (Ti–6Al–4V)–xH have been studied and developed, but are not well established due to methodological limitations. In this paper, in situ studies of phase transformations during hydrogenation and dehydrogenation of (Ti–6Al–4V)–xH alloys were conducted using high-energy synchrotron X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The eutectoid phase transformation of ? ? ? + ? was observed in the (Ti–6Al–4V)–xH alloy via in situ synchrotron XRD at 211 °C with a hydrogen concentration of 37.5 at.% (measured using TGA–DSC). The relationships of hydrogen composition to partial pressure and temperature were investigated in the temperature range 450–900 °C. Based on these results, a partial pseudo-binary phase diagram of (Ti–6Al–4V)–xH is proposed for hydrogen compositions up to 60 at.% in the temperature range 100–900 °C. Using the data collected in real time under controlled parameters of temperature, composition and hydrogen partial pressure, this work characterizes relevant phase transformations and microstructural evolution for practical titanium–hydrogen technologies of Ti–6Al–4V

  17. Strain-free GaN thick films grown on single crystalline ZnO buffer layer with in situ lift-off technique

    International Nuclear Information System (INIS)

    Strain-free freestanding GaN layers were prepared by in situ lift-off process using a ZnO buffer as a sacrificing layer. Thin Zn-polar ZnO layers were deposited on c-plane sapphire substrates, which was followed by the growth of Ga-polar GaN layers both by molecular beam epitaxy (MBE). The MBE-grown GaN layer acted as a protecting layer against decomposition of the ZnO layer and as a seeding layer for GaN growth. The ZnO layer was completely in situ etched off during growth of thick GaN layers at low temperature by hydride vapor phase epitaxy. Hence freestanding GaN layers were obtained for the consecutive growth of high-temperature GaN thick layers. The lattice constants of freestanding GaN agree with those of strain-free GaN bulk. Extensive microphotoluminescence study indicates that strain-free states extend throughout the high-temperature grown GaN layers

  18. Application of small-signal modeling and measurement techniques to the stability analysis of an integrated switching-mode power system. [onboard Dynamics Explorer Satellite

    Science.gov (United States)

    Wong, R. C.; Owen, H. A., Jr.; Wilson, T. G.; Rodriguez, G. E.

    1980-01-01

    Small-signal modeling techniques are used in a system stability analysis of a breadboard version of a complete functional electrical power system. The system consists of a regulated switching dc-to-dc converter, a solar-cell-array simulator, a solar-array EMI filter, battery chargers and linear shunt regulators. Loss mechanisms in the converter power stage, including switching-time effects in the semiconductor elements, are incorporated into the modeling procedure to provide an accurate representation of the system without requiring frequency-domain measurements to determine the damping factor. The small-signal system model is validated by the use of special measurement techniques which are adapted to the poor signal-to-noise ratio encountered in switching-mode systems. The complete electrical power system with the solar-array EMI filter is shown to be stable over the intended range of operation.

  19. Thermal Stability of Oil Palm Empty Fruit Bunch (OPEFB) Nanocrystalline Cellulose: Effects of post-treatment of oven drying and solvent exchange techniques

    Science.gov (United States)

    Indarti, E.; Marwan; Wanrosli, W. D.

    2015-06-01

    Nanocrystallinecellulose (NCC) from biomass is a promising material with huge potentials in various applications. A big challenge in its utilization is the agglomeration of the NCC's during processing due to hydrogen bonding among the cellulose chains when in close proximity to each other. Obtaining NCC's in a non-agglomerated and non-aqueous condition is challenging. In the present work NCC's was isolated from oil palm empty fruit bunch (OPEFB) using TEMPO-oxidation reaction method. To obtain non-agglomerated and non-aqueous products, the NCC's underwent post-treatment using oven drying (OD) and solvent exchanged (SE) techniques. The thermal stability of all samples was determined from TGA and DTG profiles whilst FTIR was used to analyzethe chemical modifications that occurred under these conditions. NCC-SE has better thermal stability than the NCC-OD and its on-set degradation temperature and residue are also higher. FTIR analysis shows that NCC-SE has a slightly different chemical composition whereby the absorption band at 1300 cm-1 (due to C-O symmetric stretching) is absent as compared to NCC-OD indicating that in NCC-SE the carboxylate group is in acid form which contribute to its thermal stability

  20. On the Application of a Response Surface Technique to Analyze Roll-over Stability of Capsules with Airbags Using LS-Dyna

    Science.gov (United States)

    Horta, Lucas G.; Reaves, Mercedes C.

    2008-01-01

    As NASA moves towards developing technologies needed to implement its new Exploration program, studies conducted for Apollo in the 1960's to understand the rollover stability of capsules landing are being revisited. Although rigid body kinematics analyses of the roll-over behavior of capsules on impact provided critical insight to the Apollo problem, extensive ground test programs were also used. For the new Orion spacecraft being developed to implement today's Exploration program, new air-bag designs have improved sufficiently for NASA to consider their use to mitigate landing loads to ensure crew safety and to enable re-usability of the capsule. Simple kinematics models provide only limited understanding of the behavior of these air bag systems, and more sophisticated tools must be used. In particular, NASA and its contractors are using the LS-Dyna nonlinear simulation code for impact response predictions of the full Orion vehicle with air bags by leveraging the extensive air bag prediction work previously done by the automotive industry. However, even in today's computational environment, these analyses are still high-dimensional, time consuming, and computationally intensive. To alleviate the computational burden, this paper presents an approach that uses deterministic sampling techniques and an adaptive response surface method to not only use existing LS-Dyna solutions but also to interpolate from LS-Dyna solutions to predict the stability boundaries for a capsule on airbags. Results for the stability boundary in terms of impact velocities, capsule attitude, impact plane orientation, and impact surface friction are discussed.

  1. Aplicaciones e inconvenientes de la técnica Hibridación in situ Fluorescente (FISH) en la identificación de microorganismos / Applications and inconvenient of Fluorescence in situ hybridization technique (FISH) in the identification of microorganism

    Scientific Electronic Library Online (English)

    Raúl, Rodríguez Martínez; Gina, Suescún Otero.

    2013-05-01

    Full Text Available Durante el transcurso de los últimos años se ha reportado un gran número de aplicaciones de la técnica FISH, la cual es utilizada en la detección de microorganismos en su propio hábitat sin que requieran de su previo aislamiento y purificación. La importancia de FISH radica en la capacidad que tiene [...] la sonda de ADN de detectar una región específica del ácido nucleico de la célula microbiana y ser visualizada por microscopía de epifluorescencia. En esta revisión se describe los diversos usos que tiene FISH, que van desde la identificación de la microbiota en ambientes acuáticos y su empleo en la biorremediación hasta la detección de patógenos en el diagnóstico clínico. Asimismo, se presentan algunas limitaciones, y los posibles correctivos que se deben tener encuenta cuando se aplica esta técnica. Abstract in english During these recent years, a large number of FISH technique applications have been reported. These techniques have been used in the detection of microorganisms in their own habitat without requiring their previous isolation and purification. The importance of FISH lies in the ability of the DNA prob [...] e to detect a specific region of the nucleic acid of microbial cells and to be visualized by epifluorescence microscopy. This review describes the various FISH uses ranging from the identification of the microbiota in aquatic environments and their use in bioremediation, to the detection of pathogens in clinical diagnosis. It also presents some limitations as well as the potential solutions to be applied when the FISH technique is used.

  2. Tracer-level radioactive pilot-scale test of in situ vitrification for the stabilization of contaminated soil sites at ORNL

    Energy Technology Data Exchange (ETDEWEB)

    Spalding, B.P.; Jacobs, G.K.; Naney, M.T. (Oak Ridge National Lab., TN (United States)); Dunbar, N.W. (New Mexico Bureau of Mines and Mineral Resources, Socorro, NM (United States)); Tixier, J.S.; Powell, T.D. (Pacific Northwest Lab., Richland, WA (United States))

    1992-11-01

    A field demonstration of in situ vitrification (ISV) was completed in May 1991, and produced approximately 12 Mg of melted earthen materials containing 12.7 mCi of radioactivity within 500 g of sludge in amodel of an old seepage trench waste disposal unit. Past waste disposal operations at Oak Ridge National Laboratory have left several contaminated seepage sites. In planning for remediation of such sites, ISV technology has been identified as a leading candidate because of the high risks associated with any retrieval option and because of the usual high quality of vitreous waste form. Major isotopes placed in the test trench were [sup 137]Cs and [sup 90]Sr, with lesser amounts of [sup 6O]Co, [sup 241]Am, and [sup 239,240]Pu. A total of 29 MWh of electrical power was delivered to the ground over a 5-day period producing a melt depth of 8.5 ft. During melting, 2.4% of the [sup 137]Cs volatilized from the melt into an off-gas containment hood and was captured quantitatively on a high efficiency particulate air filter. No volatilization of [sup 90]Sr, [sup 241]Am, or [sup 239,240]Pu was detected and > 99.993% retention of these isotopes in the melt was estimated. The use of added rare earth tracers (Ce, La, and Nd), as surrogates for transuranic isotopes, led to estimated melt retentions of >99.9995% during the test. The molten material, composed of the native soil and dolomitic limestone used for filling the test trench, reached a processing temperature of 1500[degrees]C. Standardized leaching procedures using Product Consistency Testing indicated that the ISV product has excellent characteristics relative to other vitreous nuclear waste forms.

  3. Tracer-level radioactive pilot-scale test of in situ vitrification for the stabilization of contaminated soil sites at ORNL

    Energy Technology Data Exchange (ETDEWEB)

    Spalding, B.P.; Jacobs, G.K.; Naney, M.T. [Oak Ridge National Lab., TN (United States); Dunbar, N.W. [New Mexico Bureau of Mines and Mineral Resources, Socorro, NM (United States); Tixier, J.S.; Powell, T.D. [Pacific Northwest Lab., Richland, WA (United States)

    1992-11-01

    A field demonstration of in situ vitrification (ISV) was completed in May 1991, and produced approximately 12 Mg of melted earthen materials containing 12.7 mCi of radioactivity within 500 g of sludge in amodel of an old seepage trench waste disposal unit. Past waste disposal operations at Oak Ridge National Laboratory have left several contaminated seepage sites. In planning for remediation of such sites, ISV technology has been identified as a leading candidate because of the high risks associated with any retrieval option and because of the usual high quality of vitreous waste form. Major isotopes placed in the test trench were {sup 137}Cs and {sup 90}Sr, with lesser amounts of {sup 6O}Co, {sup 241}Am, and {sup 239,240}Pu. A total of 29 MWh of electrical power was delivered to the ground over a 5-day period producing a melt depth of 8.5 ft. During melting, 2.4% of the {sup 137}Cs volatilized from the melt into an off-gas containment hood and was captured quantitatively on a high efficiency particulate air filter. No volatilization of {sup 90}Sr, {sup 241}Am, or {sup 239,240}Pu was detected and > 99.993% retention of these isotopes in the melt was estimated. The use of added rare earth tracers (Ce, La, and Nd), as surrogates for transuranic isotopes, led to estimated melt retentions of >99.9995% during the test. The molten material, composed of the native soil and dolomitic limestone used for filling the test trench, reached a processing temperature of 1500{degrees}C. Standardized leaching procedures using Product Consistency Testing indicated that the ISV product has excellent characteristics relative to other vitreous nuclear waste forms.

  4. Effect of inorganic amendments for in situ stabilization of cadmium in contaminated soils and its phyto-availability to wheat and rice under rotation.

    Science.gov (United States)

    Rehman, Muhammad Zia-Ur; Rizwan, Muhammad; Ghafoor, Abdul; Naeem, Asif; Ali, Shafaqat; Sabir, Muhammad; Qayyum, Muhammad Farooq

    2015-11-01

    Cadmium (Cd) toxicity is a widespread problem in crops grown on contaminated soils, and little information is available on the role of inorganic amendments in Cd immobilization, uptake, and tolerance in crops especially under filed conditions. The effect of three amendments, monoammonium phosphate (MAP), gypsum, and elemental sulfur (S), on Cd immobilization in soil and uptake in wheat and rice plants, under rotation, were investigated under field conditions receiving raw city effluent since >20 years and contaminated with Cd. Three levels of each treatment, 0.2, 0.4, and 0.8 % by weight, were applied at the start of the experiment, and wheat was sown in the field. After wheat harvesting, rice was sown in the same field without application of amendments. Both crops were harvested at physiological maturity, and data regarding grain yield, straw biomass, Cd concentrations, and uptake in grain and straw, and bioavailable Cd in soil and soil pH were recorded. Both MAP and gypsum application increased grain yield and biomass of wheat and rice, while S application did not increase the yield of both crops. MAP and gypsum amendments decreased gain and straw Cd concentrations and uptake in both crops, while S application increased Cd concentrations in these parts which were correlated with soil bioavailable Cd. We conclude that MAP and gypsum amendments could be used to decrease Cd uptake by plants receiving raw city effluents, and gypsum might be a better amendment for in situ immobilization of Cd due to its low cost and frequent availability. PMID:26109220

  5. Tracer-level radioactive pilot-scale test of in situ vitrification for the stabilization of contaminated soil sites at ORNL

    International Nuclear Information System (INIS)

    A field demonstration of in situ vitrification (ISV) was completed in May 1991, and produced approximately 12 Mg of melted earthen materials containing 12.7 mCi of radioactivity within 500 g of sludge in amodel of an old seepage trench waste disposal unit. Past waste disposal operations at Oak Ridge National Laboratory have left several contaminated seepage sites. In planning for remediation of such sites, ISV technology has been identified as a leading candidate because of the high risks associated with any retrieval option and because of the usual high quality of vitreous waste form. Major isotopes placed in the test trench were 137Cs and 90Sr, with lesser amounts of 6OCo, 241Am, and 239,240Pu. A total of 29 MWh of electrical power was delivered to the ground over a 5-day period producing a melt depth of 8.5 ft. During melting, 2.4% of the 137Cs volatilized from the melt into an off-gas containment hood and was captured quantitatively on a high efficiency particulate air filter. No volatilization of 90Sr, 241Am, or 239,240Pu was detected and > 99.993% retention of these isotopes in the melt was estimated. The use of added rare earth tracers (Ce, La, and Nd), as surrogates for transuranic isotopes, led to estimated melt retentions of >99.9995% during the test. The molten material, composed of the native soil and dolomitic limestone used for filling the test trench, reached a processing temperature of 1500 degrees C. Standardized leaching procedures using Product Consistency Testing indicated that the ISV product has excellent characteristics relative to other vitreous nuclear waste forms

  6. Enzymatic product-mediated stabilization of CdS quantum dots produced in situ: application for detection of reduced glutathione, NADPH, and glutathione reductase activity.

    Science.gov (United States)

    Garai-Ibabe, Gaizka; Saa, Laura; Pavlov, Valeri

    2013-06-01

    Glutathione is the most abundant nonprotein molecule in the cell and plays an important role in many biological processes, including the maintenance of intracellular redox states, detoxification, and metabolism. Furthermore, glutathione levels have been linked to several human diseases, such as AIDS, Alzheimer disease, alcoholic liver disease, cardiovascular disease, diabetes mellitus, and cancer. A novel concept in bioanalysis is introduced and applied to the highly sensitive and inexpensive detection of reduced glutathione (GSH), over its oxidized form (GSSG), and glutathione reductase (GR) in human serum. This new fluorogenic bioanalytical system is based on the GSH-mediated stabilization of growing CdS nanoparticles. The sensitivity of this new assay is 5 pM of GR, which is 3 orders of magnitude better than other fluorogenic methods previously reported. PMID:23656502

  7. In-situ and Remote-Sensing Data Fusion Using Machine Learning Techniques to Infer Urban and Fire Related Pollution Plumes

    Science.gov (United States)

    Segal-Rosenhaimer, M.; Russell, P. B.; Schmid, B.; Redemann, J.; Livingston, J. M.; Flynn, C. J.; Johnson, R. R.; Dunagan, S. E.; Shinozuka, Y.; Kacenelenbogen, M. S.; Chatfield, R. B.

    2014-12-01

    Airmass type characterization is key in understanding the relative contribution of various emission sources to atmospheric composition and air quality and can be useful in bottom-up model validation and emission inventories. However, classification of pollution plumes from space is often not trivial. Sub-orbital campaigns, such as SEAC4RS (Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys) give us a unique opportunity to study atmospheric composition in detail, by using a vast suite of in-situ instruments for the detection of trace gases and aerosols. These measurements allow identification of spatial and temporal atmospheric composition changes due to various pollution plumes resulting from urban, biogenic and smoke emissions. Nevertheless, to transfer the knowledge gathered from such campaigns into a global spatial and temporal context, there is a need to develop workflow that can be applicable to measurements from space. In this work we rely on sub-orbital in-situ and total column remote sensing measurements of various pollution plumes taken aboard the NASA DC-8 during 2013 SEAC4RS campaign, linking them through a neural-network (NN) algorithm to allow inference of pollution plume types by input of columnar aerosol and trace-gas measurements. In particular, we use the 4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research) airborne measurements of wavelength dependent aerosol optical depth (AOD), particle size proxies, O3, NO2 and water vapor to classify different pollution plumes. Our method relies on assigning a-priori "ground-truth" labeling to the various plumes, which include urban pollution, different fire types (i.e. forest and agriculture) and fire stage (i.e. fresh and aged) using cluster analysis of aerosol and trace-gases in-situ and expert input and the training of a NN scheme to fit the best prediction parameters using 4STAR measurements as input. We explore our misclassification rates as related to our "ground-truth" labels, and with multi-layered pollution plume cases. The next step in our analysis is to optimize parameter selection for a scheme that can be applied to space-borne aerosol and trace-gas observation platforms such as OMI, and future geostationary satellites such as TEMPO and GEO-CAPE.

  8. Influence of the stabilizer coating layer on the purification and freeze-drying of poly(D,L-lactic acid) nanoparticles prepared by an emulsion-diffusion technique.

    Science.gov (United States)

    Quintanar-Guerrero, D; Ganem-Quintanar, A; Allémann, E; Fessi, H; Doelker, E

    1998-01-01

    In this study, the purification by cross-flow filtration (CFF) and freeze drying of poly(D,L-lactic acid) (PLA) nanoparticles prepared by an emulsion-diffusion technique using poly(vinyl alcohol) (PVAL) or poloxamer 188 (P-188) were investigated. The stability of the suspensions was correlated to the affinity of the stabilizers for the nanoparticle surface, the resistance of the coating layer to continuous filtration and to freeze-thawing procedures. The results indicated a clear difference between the two stabilizers, suggesting that the nature of the coating layer has a very important role during CFF and freeze-drying. Nanoparticles prepared with PVAL were filtered and freeze-dried without nanoparticle fusion. This behaviour was attributed to the formation of a stable thick layer (similar to that found for polystyrene latex). In contrast, aggregation of nanoparticles was observed during CFF for the batches prepared with P-188, indicating that the polypropylene oxide blocks present in the copolymer have little affinity for the PLA surface. However, these suspensions were successfully recovered when using stabilizer solutions as diafiltration media, suggesting a dynamic exchange between the P-188-adsorbed chains and those of the identical polymer remaining in the bulk solution. The presence of P-188 did not prevent nanoparticle aggregation after freeze-drying. Therefore, the use of cryoprotectants was necessary. Aggregation may have been due to an increase in the solubility of P-188 in the bulk solution, which provokes a destabilization of the suspension by desorption and partial coverage of the surface. The best cryoprotectants were found to be sugars containing glucose units. The cryoprotective effect was related to the hydrogen bonding capability of these sugars, which prevented aggregation by dehydration of P-188 forcing it to the PLA surface. PMID:9463812

  9. Development of Evaluation Technique for Hydrogen Embrittlement Behavior of Metallic Materials Using in-situ SP Testing under Pressurized Hydrogen Gas Conditions

    International Nuclear Information System (INIS)

    Recently, alternative and novel energy resources have been developed for use in the future because of the current environmental problems and exhaustion of fossil energy resources. Hydrogen energy has many merits, such as its environmental friendliness, easy storage, and easy production, but it also has disadvantages, in that it is highly combustible and explosive. In this study, a test procedure using a simple SP test under highly pressurized hydrogen gas conditions was established. In order to evaluate its applicability, SP tests were carried out using a stainless steel (SUS316L) sample under atmospheric, pressurized helium, and pressurized hydrogen gas conditions. The results under the pressurized hydrogen gas condition showed fissuring and produced a reduction of the elongation in the plastic instability region due to hydrogen embrittlement, showing the effectiveness of the current in-situ SP test

  10. Study and applications of XRF measuring technique in-situ for gold exploration in the periphery of the manaoke gold mine

    International Nuclear Information System (INIS)

    Characteristics of the XRF anomalies above the known golden ore body have been studied in the periphery of the Manaoke Gold Mine. By multi-element XRF measurement in-situ in soil, four As, Cu, Pb, Zn, Sr composite anomalies have acquired rapidly. On the basis of Characteristics of the XRF anomalies, the nature of the all of the XRF anomalies have been affirmed, and the two new target areas of golden exploration have been defined. Be analysis of the sampled soil in the new target areas, it is indicated that the golden content of great majority of soil samples are above the background. The highest golden content is 290 x 10-9, and is more 100 times than the background. It is indicated incontestably that the XRF anomalies in new target areas are the anomalies of golden ore body. (authors)

  11. Determination of the stability constant of the antimony-triphenyltetrazoliumchloride complex in strong acidic media using radiochemical techniques

    International Nuclear Information System (INIS)

    2,3,5-Triphenyltetrazoliumchloride was used as extraction agent to extract Sb(V) even in traces from 6M HCl solutions. The high acidity is necessary to transform all Sb(V) species to [Sb(OH)2Cl4]-. 125Sb was used as tracer. A contact time of 100 minutes was needed to achieve equilibrium. The molar ratio of the ion associate in the organic phase is found to be 1:1. The following data were obtained by means of graphic evaluation: extraction constant Ksub(ex) = 1,65.104, distribution constant Ksub(D)=19,95, stability constant of the ion associate ?=0,83.103. According to the results the method seems to be of usefulness to extract trace amounts of Sb(V). Quantitative analysis can be carried out by means of photometric detection from the organic phase. Further investigations are needed to determine the interfering elements. (T.G.)

  12. Final report, Ames Mobile Laboratory Project: The development and operation of instrumentation in a mobile laboratory for in situ, real-time screening and characterization of soils using the laser ablation sampling technique

    International Nuclear Information System (INIS)

    The main focus of the Ames Laboratory's Technology Integration Program, TIP, from May 1991 through December 1994 was the development, fabrication, and demonstration of a mobile instrumentation laboratory incorporating rapid in situ sampling systems for safe, rapid, and cost effective soil screening/characterization. The Mobile Demonstration Laboratory for Environmental Screening Technologies, MDLEST, containing the analysis instrumentation, along with surface and subsurface sampling probe prototypes employing the laser ablation sampling technique were chosen to satisfy the particular surface and subsurface soil characterization needs of the various Department of Energy facilities for determining the extent of heavy metal and radionuclide contamination. The MDLEST, a 44 foot long 5th wheel trailer, is easily configured for the analysis instrumentation and sampling system required for the particular site work. This mobile laboratory contains all of the utilities needed to satisfy the operating requirements of the various instrumentation installed. These utilities include, an electric generator, a chilled water system, process gases, a heating/air conditioning system, and computer monitoring and automatic operating systems. Once the MDLEST arrives at the job site, the instrumentation is aligned and calibration is completed, sampling and analysis operations begin. The sample is acquired, analyzed and the results reported in as little as 10 minutes. The surface sampling probe is used in two modes to acquire samples for analysis. It is either set directly on the ground over the site to be sampled, in situ sampling, or in a special fixture used for calibrating the sampling analysis system with standard soil samples, having the samples brought to the MDLEST. The surface sampling probe was used to in situ sample a flat concrete surface (nondestructively) with the ablated sample being analyzed by the instrumentation in the MDLEST

  13. In situ stabilization/solidification pilot testing of coal tar contaminated sediment focusing on mix uniformity, post-treatment curing and workability evaluation, Sydney Harbour, Nova Scotia

    Energy Technology Data Exchange (ETDEWEB)

    Carbonneau, K.; Flood, P.J.; Noble, B. [AECOM Environmental, Los Angeles, CA (United States)

    2010-07-01

    A study conducted by Environment Canada during the 1980s demonstrated the presence of polycyclic aromatic hydrocarbons (PAHs) above risk benchmarks for aquatic organisms in the sediments of estuarine ponds located in Sydney Harbour, Nova Scotia. This paper presented the results of pilot-scale demonstration conducted to determine post-treatment uniformity and workability of the solidification/stabilization (S/S) solution used to remove exposure pathways, reduce erodability, and improve sediment strength. Interlocking steel sheet pile (SSP) was driven through the sediment into the underlying natural soils in 6 distinct cells in order to evaluate multiple reagent mix designs. Grain size distribution, moisture content, and sediment bulk density were measured. Dynamic cone penetrometer tests were conducted after each cell was mixed. Samples were taken to assess unconfined compressive strength and hydraulic conductivity. The post-treatment curing and workability rate was also assessed. Results of the study showed consistent hardness with depth in each cell and increasing hardness with depth as a function of the cement content of the mix. The post-treated material did not exhibit a well-defined moisture density relationship. Moisture sensitivity was demonstrated by a rapid loss of strength upon a relatively small increase in moisture content. 5 refs., 3 tabs., 8 figs.

  14. Warm Tropical Sea Surface Temperatures During the Pliocene: a New Record from Mg/Ca and ?18O In Situ Techniques

    Science.gov (United States)

    Wycech, J.; Kelly, D.; Kozdon, R.; Fournelle, J.; Valley, J. W.

    2013-12-01

    The Pliocene Warm Period (PWP) was a global warming event that punctuated Earth's climate history ~3 Ma, and study of its geologic record is providing important constraints for models predicting future climate change. Many sea surface temperature (SST) reconstructions for the PWP indicate amplified polar warmth with minimal or absent warming in the tropics - a phenomenon termed the cool tropics paradox. Key pieces of evidence for the lack of tropical warmth are oxygen isotope (?18O) and Mg/Ca ratios in planktic foraminiferal shells. However, the ?18O data used to reconstruct surface-ocean conditions are derived from whole foraminiferal shells with the assumption that their geochemical compositions are well preserved and homogeneous. To the contrary, most planktic foraminiferal shells found in deep-sea sediments are an aggregate mixture of three carbonate phases (18O-depleted pre-gametogenic calcite, 18O-rich gametogenic calcite added during reproduction, and very 18O-rich diagenetic calcite) that formed under different physiological and/or environmental conditions. Here we report preliminary results of an ongoing study that uses secondary ion mass spectrometry (SIMS) and electron probe microanalysis (EPMA) to acquire in situ ?18O and Mg/Ca data, respectively, from 3-10 ?m domains within individual planktic foraminiferal shells (Globigerinoides sacculifer) preserved in a PWP record recovered at ODP Site 806 in the West Pacific Warm Pool. SIMS analyses show that the ?18O of gametogenic calcite is 1-2‰ higher than in the pre-gametogenic calcite of Gs. sacculifer. Mass-balance calculations using the mean ?18O of gametogenic and pre-gametogenic calcites predict a whole-shell ?18O that is ~1.9‰ lower than the published whole-shell ?18O for Gs. sacculifer in this same deep-sea section. Removal of 18O-depleted, pre-gametogenic calcite via dissolution cannot fully account for this isotopic offset since the mean ?18O of whole shells (-1.3‰) is higher than that of gametogenic calcite (-2.1‰); hence, we attribute the elevated whole-shell values to the addition of 18O-rich carbonate by post-depositional diagenesis. By contrast, in situ measurements indicate that the Mg/Ca ratios in the pre-gametogenic and gametogenic calcites are indistinguishable, and in situ Mg/Ca ratios are comparable to those of whole shells. Use of Mg/Ca calculated SSTs (~30°C) and published whole-shell ?18O to determine the ?18O of seawater (?18Osw) yields unrealistically high values (2.1‰), while a similar computation using pre-gametogenic ?18O yields a more acceptable ?18Osw (-0.2‰) for this region during the PWP. This latter finding corroborates the view that the published whole-shell ?18O record has been compromised by diagenesis and demonstrates the potential of SIMS ?18O analysis to enhance our ability to reconstruct hydrographic conditions under differing climatic regimes.

  15. Detecting in situ copepod diet diversity using molecular technique: development of a copepod/symbiotic ciliate-excluding eukaryote-inclusive PCR protocol.

    Science.gov (United States)

    Hu, Simin; Guo, Zhiling; Li, Tao; Carpenter, Edward J; Liu, Sheng; Lin, Senjie

    2014-01-01

    Knowledge of in situ copepod diet diversity is crucial for accurately describing pelagic food web structure but is challenging to achieve due to lack of an easily applicable methodology. To enable analysis with whole copepod-derived DNAs, we developed a copepod-excluding 18S rDNA-based PCR protocol. Although it is effective in depressing amplification of copepod 18S rDNA, its applicability to detect diverse eukaryotes in both mono- and mixed-species has not been demonstrated. Besides, the protocol suffers from the problem that sequences from symbiotic ciliates are overrepresented in the retrieved 18S rDNA libraries. In this study, we designed a blocking primer to make a combined primer set (copepod/symbiotic ciliate-excluding eukaryote-common: CEEC) to depress PCR amplification of symbiotic ciliate sequences while maximizing the range of eukaryotes amplified. We firstly examined the specificity and efficacy of CEEC by PCR-amplifying DNAs from 16 copepod species, 37 representative organisms that are potential prey of copepods and a natural microplankton sample, and then evaluated the efficiency in reconstructing diet composition by detecting the food of both lab-reared and field-collected copepods. Our results showed that the CEEC primer set can successfully amplify 18S rDNA from a wide range of isolated species and mixed-species samples while depressing amplification of that from copepod and targeted symbiotic ciliate, indicating the universality of CEEC in specifically detecting prey of copepods. All the predetermined food offered to copepods in the laboratory were successfully retrieved, suggesting that the CEEC-based protocol can accurately reconstruct the diets of copepods without interference of copepods and their associated ciliates present in the DNA samples. Our initial application to analyzing the food composition of field-collected copepods uncovered diverse prey species, including those currently known, and those that are unsuspected, as copepod prey. While testing is required, this protocol provides a useful strategy for depicting in situ dietary composition of copepods. PMID:25058323

  16. Monitoring the long term stability and sinkhole of shallow underground cavities using micro-seismic technique - gypsum mine (Jura, France)

    Science.gov (United States)

    Balland, C.; Alheib, M.; Didier, C.

    2009-12-01

    The collapse of underground cavities (natural and manmade) can produce subsidence events on surface. The evolution of the roof instability may develop during several years before reaching the surface. To anticipate damages of buildings and infrastructures, expensive techniques are available (backfilling, pillars and roof support). In some context, monitoring may constitute a promising alternative. Micro-seismic monitoring is probably one of the most monitoring techniques adapted to the underground context. It enables to record the acoustic activity produced by disorder development within the unstable cavities. This technique was tested in an underground gypsum mine (Jura, France). This mine has been closed after more than 50 years of undermining and appears sensitive to important probability of pillars failure and sinkholes (Figure 1). In order to understand the mechanical behaviors involved, and to record the eventual seismic precursors of collapse, two micro-seismic networks were installed within two unstable zones, one mainly concerned by roof failure, the other one characterized by risk of major superimposed pillar collapse. 6 years of micro-seismic data, corresponding to 650 events, were recorded, analyzed and located. Our study shows only few significant events recorded at the deeper zone with multi-levels structure. On the opposite, the sinkhole zone is characterized by a fast evolution with high seismic activity (cracks in the overburden and frequent block falls). Sinkholes development seems to occur preferentially through major crisis (up to 95 events per 24 hours), few days after the rainiest periods. The micro-seismic method appeared to be very efficient to follow the underground sinkhole activity and to anticipate the consequences at the surface. It so may be an interesting alternative to treatment during a transitional phase during which the probability of underground failure is high. Figure 1 : Recent collapse of a sinkhole in surface (Jura, France).

  17. Research and development of treatment techniques for LLW from decommissioning: Decontamination and volume reduction techniques

    International Nuclear Information System (INIS)

    For the purpose of reducing the amount and/or volume of low-level radioactive waste (LLW) arising from decommissioning of nuclear reactor, the Japan Atomic Energy Research Institute (JAERI) has been developing four decontamination techniques. They are: (a) Gas-carrying abrasive method, (b) In-situ remote electropolishing method for pipe system before dismantling, (c) Bead reaction - thermal shock method, and (d) Laser induced chemical method for components after dismantling. JAERI in developing techniques are also carrying out melting tests of metal and non-metal. Melting was confirmed to be effective in reducing the volume, homogenizing, and furthermore stabilizing non-metallic wastes. (author)

  18. Charge collection microscopy of in-situ switchable PRAM line cells in a scanning electron microscope: Technique development and unique observations

    International Nuclear Information System (INIS)

    An imaging method has been developed based on charge collection in a scanning electron microscope (SEM) that allows discrimination between the amorphous and crystalline states of Phase-change Random Access Memory (PRAM) line cells. During imaging, the cells are electrically connected and can be switched between the states and the resistance can be measured. This allows for electrical characterization of the line cells in-situ in the SEM. Details on sample and measurement system requirements are provided which turned out to be crucial for the successful development of this method. Results show that the amorphous or crystalline state of the line cells can be readily discerned, but the spatial resolution is relatively poor. Nevertheless, it is still possible to estimate the length of the amorphous mark, and also for the first time, we could directly observe the shift of the amorphous mark from one side of the line cell to the other side when the polarity of the applied (50 ns) RESET pulse was reversed

  19. Charge collection microscopy of in-situ switchable PRAM line cells in a scanning electron microscope: Technique development and unique observations

    Energy Technology Data Exchange (ETDEWEB)

    Oosthoek, J. L. M.; Schuitema, R. W.; Brink, G. H. ten; Kooi, B. J., E-mail: B.J.Kooi@rug.nl [Zernike Institute for Advanced Materials and Materials innovation institute M2i, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands); Gravesteijn, D. J. [NXP Semiconductors, Kapeldreef 75, B 3001 Leuven (Belgium)

    2015-03-15

    An imaging method has been developed based on charge collection in a scanning electron microscope (SEM) that allows discrimination between the amorphous and crystalline states of Phase-change Random Access Memory (PRAM) line cells. During imaging, the cells are electrically connected and can be switched between the states and the resistance can be measured. This allows for electrical characterization of the line cells in-situ in the SEM. Details on sample and measurement system requirements are provided which turned out to be crucial for the successful development of this method. Results show that the amorphous or crystalline state of the line cells can be readily discerned, but the spatial resolution is relatively poor. Nevertheless, it is still possible to estimate the length of the amorphous mark, and also for the first time, we could directly observe the shift of the amorphous mark from one side of the line cell to the other side when the polarity of the applied (50 ns) RESET pulse was reversed.

  20. Development and Testing of Techniques for In-Ground Stabilization, Size Reduction and Safe Removal of Radioactive Wastes Stored in Large Containments in Burial Grounds - 13591

    International Nuclear Information System (INIS)

    Radioactive waste materials, including Transuranic (TRU) wastes from laboratories have been stored below ground in large containments at a number of sites in the US DOE Complex, and at nuclear sites in Europe. These containments are generally referred to as caissons or shafts. The containments are in a range of sizes and depths below grade. The caissons at the DOE's Hanford site are cylindrical, of the order of 2,500 mm in diameter, 3,050 mm in height and are buried about 6,000 mm below grade. One type of caisson is made out of corrugated pipe, whereas others are made of concrete with standard re-bar. However, the larger shafts in the UK are of the order of 4,600 mm in diameter, 53,500 mm deep, and 12,000 below grade. This paper describes the R and D work and testing activities performed to date to evaluate the concept of in-ground size reduction and stabilization of the contents of large containments similar to those at Hanford. In practice, the height of the Test Facility provided for a test cell that was approximately 22' deep. That prevented a 'full scale mockup' test in the sense that the Hanford Caisson configuration would be an identical replication. Therefore, the project was conducted in two phases. The first phase tested a simulated Caisson with surrogate contents, and part of a Chute section, and the second phase tested a full chute section. These tests were performed at VJ Technologies Test Facility located in East Haven, CT, as part of the Proof of Design Concept program for studying the feasibility of an in-situ grout/grind/mix/stabilize technology for the remediation of four caissons at the 618-11 Burial Ground at US Department of Energy Hanford Site. The test site was constructed such that multiple testing areas were provided for the evaluation of various tools, equipment and procedures under conditions that simulated the Hanford site, with representative soils and layout dimensions. (authors)

  1. A review of joining techniques for SiC{sub f}/SiC composites for first wall applications

    Energy Technology Data Exchange (ETDEWEB)

    Lewinsohn, C.A.; Jones, R.H. [Pacific Northwest National Lab., Richland, WA (United States)

    1998-09-01

    Many methods for joining monolithic and composite silicon carbide are available. Three techniques are candidates for use in fusion energy systems: in-situ displacement reactions, pre-ceramic polymer adhesives, and reaction bonding. None of the methods are currently developed enough to satisfy all of the criteria required, i.e., low temperature fabrication, high strength, and radiation stability. 58 refs.

  2. System for enhanced longevity of in situ microbial filter used for bioremediation

    Science.gov (United States)

    Carman, M. Leslie (San Ramon, CA); Taylor, Robert T. (Roseville, CA)

    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.

  3. Method for enhanced longevity of in situ microbial filter used for bioremediation

    Science.gov (United States)

    Carman, M. Leslie (San Ramon, CA); Taylor, Robert T. (Roseville, CA)

    1999-01-01

    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.

  4. Methodology to calculate the Lyapunov exponents in real systems using dynamic reconstruction technique. Use in nuclear reactor stability studies

    International Nuclear Information System (INIS)

    In this paper we have developed a methodology to obtain the Lyapunov exponents in systems with large amounts of noise using Dynamic Reconstruction Techniques and the Eckmann algorithm. In order to validate the method, these characteristic exponents, are compared with the ones obtained directly from the governing equations of the dynamics systems[6]. Then we have obtained the Lyapunov Exponents from APRM and LPRM series from Cofrentes Nuclear Power Plant. The method we have developed has two advantages, the first one is that it can be applied to systems with large amounts of noise in any regime, and the second one is that it can be applied to small data series of low precision. (author). 18 refs, 2 figs, 3 tabs

  5. The use of GPR technique in the slope stability survey at radar doppler terminal, Bukit Tampoi, Dengkil, Selangor

    International Nuclear Information System (INIS)

    A site investigation survey using GPR technique was carried out at Radar Doppler Terminal, Bukit Tampoi, Dengkil, and Selangor. The Terminal is situated approximately 10 km to the North of Kuala Lumpur International Airport. Geologically, the study area is located in the Kenny Hill formation consisting of low grade meta sedimentary rocks mainly of quartzite and phylline. A detailed geotechnical investigation at a cut slope of Kenny Hill formation in Selangor showed that the inter bedded rock mass is dominated by relatively thick sandstone with thin shale of slightly to highly weathered materials. The objective of study is to investigate any fractured or weak zone in the study area using the GPR technique. In this survey, 100 MHz frequency antenna model RAMAC/ GPR was used as a source to send the electromagnetic wave into the ground. A control unit (CUII) was used in monitoring the antenna via a laptop. A total of 25 parallel and vertical lines with 3 m-5 m spacing between each line were traversed in the study area. The maximum subsurface depth investigated was approximately 12 m. Reflected waves arrival between 0 m to 5 m depth in the radar gram section shows discontinuous, sub parallel and wavy patterns. These chaotic reflections patterns correspond to highly weathered silt with sandstone and gravel based on nearby borehole information as well as indicated by low SPT N-values of 0 to 13. For depth deeper than 5 m, the reflection pattern is dominated by high frequency parallel waveform that could be associated with stiff mud stone of 28-34 SPT N-values. The radar gram section also shows the presence of internal features in the meta sedimentary soils and rocks such as several small scale normal faults as well as sliding planes trending northwest-southeast in direction. (author)

  6. Effect of various de-anodizing techniques on the surface stability of non-colored and colored nanoporous AAO films in acidic solution

    Science.gov (United States)

    Awad, Ahmed M.; Shehata, Omnia S.; Heakal, Fakiha El-Taib

    2015-12-01

    Anodic aluminum oxide (AAO) is well known as an important nanostructured material, and a useful template in the fabrication of nanostructures. Nanoporous anodic alumina (PAA) with high open porosity was prepared by adopting three de-anodizing regimes following the first anodizing step and preceding the second one. The de-anodizing methods include electrolytic etching (EE) and chemical etching using either phosphoric acid (PE) or sodium hydroxide (HE) solutions. Three of the obtained AAO samples were black colored by electrodeposition of copper nanoparticles in their pores. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques were used to characterize the electrochemical performance of the two sets of the prepared samples. In general, the data obtained in aggressive aerated 0.5 M HCl solution demonstrated dissimilar behavior for the three prepared samples despite that the second anodizing step was the same for all of them. The data indicated that the resistance and thickness of the inner barrier part of nano-PAA film, are the main controlling factors determining its stability. On the other hand, coloring the film decreased its stability due to the galvanic effect. The difference in the electrochemical behavior of the three colored samples was discussed based on the difference in both the pore size and thickness of the outer porous part of PAA film as supported by SEM, TEM and cross-sectional micrographs. These results can thus contribute for better engineering applications of nanoporous AAO.

  7. Development of an in-situ multi-component reinforced Al-based metal matrix composite by direct metal laser sintering technique — Optimization of process parameters

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Subrata Kumar, E-mail: subratagh82@gmail.com [Department of Mechanical Engineering, National Institute of Technology Agartala, Tripura 799055 (India); Bandyopadhyay, Kaushik; Saha, Partha [Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India)

    2014-07-01

    In the present investigation, an in-situ multi-component reinforced aluminum based metal matrix composite was fabricated by the combination of self-propagating high-temperature synthesis and direct metal laser sintering process. The different mixtures of Al, TiO{sub 2} and B{sub 4}C powders were used to initiate and maintain the self-propagating high-temperature synthesis by laser during the sintering process. It was found from the X-ray diffraction analysis and scanning electron microscopy that the reinforcements like Al{sub 2}O{sub 3}, TiC, and TiB{sub 2} were formed in the composite. The scanning electron microscopy revealed the distribution of the reinforcement phases in the composite and phase identities. The variable parameters such as powder layer thickness, laser power, scanning speed, hatching distance and composition of the powder mixture were optimized for higher density, lower porosity and higher microhardness using Taguchi method. Experimental investigation shows that the density of the specimen mainly depends upon the hatching distance, composition and layer thickness. On the other hand, hatching distance, layer thickness and laser power are the significant parameters which influence the porosity. The composition, laser power and layer thickness are the key influencing parameters for microhardness. - Highlights: • The reinforcements such as Al{sub 2}O{sub 3}, TiC, and TiB{sub 2} were produced in Al-MMC through SHS. • The density is mainly influenced by the material composition and hatching distance. • Hatching distance is the major influencing parameter on porosity. • The material composition is the significant parameter to enhance the microhardness. • The SEM micrographs reveal the distribution of TiC, TiB{sub 2} and Al{sub 2}O{sub 3} in the composite.

  8. Use of 3D cartilage scaffolds for the stabilization of implants and bone regeneration with the fit-lock technique

    Scientific Electronic Library Online (English)

    Giovanni, Falisi; Massimo, Galli; Pedro, Vittorini-Velasquez; Juan C, Gallegos-Rivera; Roberto, Minasi; Alberto, De Biase; Carlo, Di Paolo.

    2013-12-01

    Full Text Available Los procedimientos quirurgicos para la aplicacion de los implantes en los sectores latero superiores, estan condicionadas por la neumatizacion del seno y la disponibilidad del hueso residual. En estos casos el injerto de hueso autologo permanece como la mejor opcion, pero a causa de la morbilidad as [...] ociada al sitio donante y a las complicaciones post quirurgicas, se pusieron a disposicion diversas alternativas de sustitutos oseos, que implican sin embargo un aumento de los costos economicos y con limitadas propiedades osteoinductivas. Tales defectos pueden ser compensados con nuevas estrategias de regeneracion biologica y mecanica de los tejidos a los cuales fue dirigida la ingenieria biologica y mecanica en los ultimos anos. Se presenta una nueva posibilidad terapeutica en la aplicacion de los implantes en el maxilar superior con disponibilidad osea inferior a los 4 mm, mediante la utilizacion de andamios 3D confeccionados en cartilago de cerdo libre de antigenos obtenido segun la tecnica Fit-Lock. Se realizo un estudio longitudinal en 18 casos consecutivos evidenciando al cabo de un ano de la carga implantologica, un exito del 95,2%. Las ventajas en esta nueva tecnica son: 1)La recuperacion funcional y anatomica del antro del maxilar 2).La aplicacion inmediata de los implantes; 3)Reduccion de los tiempos quirurgicos; 4) Ausencia de morbilidad para el paciente; 5) Uso de anestesia local; 6)Uso de implantes con diametros superiores a los 4 mm. Abstract in english The surgical procedures for implant applications on the lateralupper areas depend on sinus pneumatization and availability of the residual bone. In these cases, autologous bone grafting remains the gold standard. Nevertheless, because of the morbidity associated to the donor site and the post-surgic [...] al complications, several alternative bone substitutes have been introduced, which, however, imply additional costs and show limited osteoinductive properties. Such limitations can be compensated with new regeneration strategies for biological and mechanical tissue restoration, a subject which has been addressed by tissue engineering in recent years. The authors present a new therapeutic option for implant application in the upper maxilla with bone availability less than 4 mm by using 3D scaffolds obtained from antigen-free porcine cartilage in the fit-lock technique. A longitudinal study on 18 consecutive cases was performed, with a 95.2% success rate one year after the implant. The advantages of this new technique are: 1)Functional and anatomical recovery of the maxillary antrum, 2) Immediate application of the implants; 3) Reduction of surgical times; 4) Absence of patient morbidity; 5)Local anesthesia; 6) Use of implants with a diameter > 4 mm.

  9. Modified stabilization method for the tibial tuberosity advancement technique: a biomechanical study / Modificação da técnica de avanço da tuberosidade tibial: estudo biomecânico

    Scientific Electronic Library Online (English)

    Bruno Testoni, Lins; Sheila Canevese, Rahal; Mário Jefferson, Louzada; José Carlos, Dalmas; André Luis, Selmi.

    2009-04-01

    Full Text Available O presente estudo teve como objetivo determinar as alterações biomecânicas decorrentes da modificação da técnica de avanço da tuberosidade tibial (TTA), originalmente descrita para estabilização da ruptura do ligamento cruzado cranial. Foram avaliados 10 cães, sem raça definida e com peso entre 25 e [...] 30kg, submetidos à eutanásia por razões independentes do presente estudo. Os membros pélvicos foram distribuídos em dois grupos: G1 operado (n=10) e G2 controle (n=10), representado pelo membro contralateral. Os membros operados foram submetidos à avaliação ortopédica, goniométrica e radiográfica nos momentos 1 (articulação intacta), 2 (após desmotomia do cruzado cranial), 3 (após estabilização articular pela TTA modificada) e 4 (após a desmotomia do cruzado caudal). A tuberosidade tibial foi estabilizada por um parafuso cortical em posicionamento craniocaudal e um espaçador de titânio inserido no local de osteotomia. A posição do tendão patelar perpendicular em relação ao platô tibial promoveu a neutralização da força de cisalhamento tibial cranial, apesar da permanência do movimento de gaveta cranial em todos os joelhos. Os testes biomecânicos confirmam a viabilidade do método empregado para estabilização da tuberosidade tibial e sustentam a realização de estudos clínicos futuros para validação da técnica. Abstract in english The present study aimed to determine biomechanical alterations resultant from a modification in the fixation method of the tibial tuberosity advancement technique (TTA), originally described for stabilization of the cranial cruciate-deficient stifle. Ten adult mongrel dogs weighing 25-30kg were used [...] . After euthanasia, performed for reasons unrelated to this study, the hind limbs were distributed into two groups: G1 operated (n=10) and G2 control (n=10), represented by the contralateral limb. The operated hind limbs were orthopedically, goniometrically and radiographically evaluated, sequentially at four moments: moment 1, in intact joints; moment 2, after cranial cruciate desmotomy; moment 3, after surgical stabilization of the stifle joint using modified TTA; and moment 4, after caudal cruciate ligament desmotomy. The tibial tuberosity was stabilized by one shaft screw craniocaudally and a titanium cage inserted at the osteotomy site. The position of the patellar tendon at 90° in relation to the tibial plateau allowed cranial tibial thrust force neutralization, despite cranial drawer motion maintenance in all dogs. The biomechanical tests confirm the viability of the tibial tuberosity fixation method and support future clinical trials to validate the technique.

  10. Acute promyelocytic leukemia: the study of t(15;17) translocation by fluorescent in situ hybridization, reverse transcriptase-polymerase chain reaction and cytogenetic techniques

    Scientific Electronic Library Online (English)

    M.L.L.F., Chauffaille; M.S., Figueiredo; R., Beltrani; S.V., Antunes; M., Yamamoto; J., Kerbauy.

    2001-06-01

    Full Text Available Acute promyelocytic leukemia (AML M3) is a well-defined subtype of leukemia with specific and peculiar characteristics. Immediate identification of t(15;17) or the PML/RARA gene rearrangement is fundamental for treatment. The objective of the present study was to compare fluorescent in situ hybridiz [...] ation (FISH), reverse transcriptase-polymerase chain reaction (RT-PCR) and karyotyping in 18 samples (12 at diagnosis and 6 after treatment) from 13 AML M3 patients. Bone marrow samples were submitted to karyotype G-banding, FISH and RT-PCR. At diagnosis, cytogenetics was successful in 10 of 12 samples, 8 with t(15;17) and 2 without. FISH was positive in 11/12 cases (one had no cells for analysis) and positivity varied from 25 to 93% (mean: 56%). RT-PCR was done in 6/12 cases and all were positive. Four of 8 patients with t(15;17) presented positive RT-PCR as well as 2 without metaphases. The lack of RT-PCR results in the other samples was due to poor quality RNA. When the three tests were compared at diagnosis, karyotyping presented the translocation in 80% of the tested samples while FISH and RT-PCR showed the PML/RARA rearrangement in 100% of them. Of 6 samples evaluated after treatment, 3 showed a normal karyotype, 1 persistence of an abnormal clone and 2 no metaphases. FISH was negative in 4 samples studied and 2 had no material for analysis. RT-PCR was positive in 4 (2 of which showed negative FISH, indicating residual disease) and negative in 2. When the three tests were compared after treatment, they showed concordance in 2 of 6 samples or, when there were not enough cells for all tests, concordance between karyotype and RT-PCR in one. At remission, RT-PCR was the most sensitive test in detecting residual disease, as expected (positive in 4/6 samples). An incidence of about 40% of 5' breaks and 60% of 3' breaks, i.e., bcr3 and bcr1/bcr2, respectively, was observed.

  11. Robust Stabilizing Leader Election

    OpenAIRE

    Delporte-Gallet, Carole; Devismes, Stéphane; Fauconnier, Hugues

    2007-01-01

    In this paper, we mix two well-known approaches of the fault-tolerance: robustness and stabilization. Robustness is the aptitude of an algorithm to withstand permanent failures such as process crashes. The stabilization is a general technique to design algorithms tolerating transient failures. Using these two approaches, we propose algorithms that tolerate both transient and crash failures. We study two notions of stabilization: the self- and the pseudo- stabilization (pseudo-stabilization is...

  12. Techniques and devices developed by the CEA for hot cell and in-situ examinations of PWR components and PWR fuel assembliess after irradiation

    International Nuclear Information System (INIS)

    Within the framework of the electro-nuclear development of the PWR system, the CEA has provided itself with facilities for developing techniques for analyzing assemblies, pins and fuels. These are examinations and tests on irradiated heads and assemblies with the aid of the Fuel Examination Module (FEM), of machining of assemblies and examinations in the Celimene hot laboratory or detailed examinations and analyses on fuel elements using eddy currents, the electronic microprobe and the Fisher ''permeascope'' which enables the outline of the oxide coat present on the cladding to be followed

  13. In situ investigation of the surface silvering of late Roman coins by combined use of high energy broad-beam and low energy micro-beam X-ray fluorescence techniques

    Science.gov (United States)

    Romano, F. P.; Garraffo, S.; Pappalardo, L.; Rizzo, F.

    2012-07-01

    The compositional analysis of archeological metals performed with the X-ray Fluorescence technique (XRF) provides information on the ancient technology. One of the most interesting case-study concerns the techniques used by Romans for silvering the surface of coins. Different metallurgical processes have been suggested in previous studies. Recently the investigation has been addressed to the mercury-silvering and to its possible use in the mass-production of coins minted during the late period (after 294 AD). In the present paper the non-destructive investigation of the silvering process used for manufacturing the Roman nummi - the important typology of coin introduced by Diocletian in his monetary reform - is approached by the combined use of the standard X-Ray Fluorescence (XRF) and the low energy micro-X-Ray Fluorescence (LE-?XRF) portable methods. The research was focused on the systematic determination of the mercury presence in a large number of samples and on its correlation with silver in the surface of the coins. 1041 Roman nummi belonging to the Misurata Treasure were analyzed in situ, at the Leptis Magna Museum (Al Khums, Libya). The treasure, composed of about 108 thousand silvered coins, gives the unique opportunity to study the Roman coinage in a wide interval of time (about 40 years in the period 294-333 AD) and in almost all the imperial mints operating in the Roman world.

  14. Ruminal Dry Matter and Crude Protein Degradability of Some Tropical (Iranian Feeds Used in Ruminant Diets Estimated Using the in situ and in vitro Techniques

    Directory of Open Access Journals (Sweden)

    2008-01-01

    Full Text Available The in situ ruminal dry matter (DM and crude protein (CP degradation and in vitro DM and CP disappearance of corn grain, soybean meal, wheat bran and alfalfa were compared. For in situ technique duplicate dacron bags were incubated for 0, 2, 4, 6, 8, 12, 16, 24, 36, 48, 72 and 96 h in two wethers fitted with ruminal cannulas. The in vitro degradability of DM and CP calculated at 0, 2, 12, 36 and 48 h incubation time for test feeds. The model of Ørskov and McDonald as y = a + b (1-e-ct was used for determination of degradation characteristics for both of methods. Wheat bran had higher soluble DM (a (30.3%, corn grain had higher insoluble potentially degradable DM (b (59.9% and soybean meal had higher degradation rate (9.67% h -1 than other feeds, inverses corn grain (14%, alfalfa (40.1% and alfalfa (3.40% h-1 had lower soluble DM, insoluble potentially degradable DM and degradation rate than other feeds, respectively. Wheat bran had higher soluble CP (a (33.3%, corn grain had higher insoluble potentially degradable CP (b (54.5% and soybean meal had higher degradation rate (9.78% h-1 than other feeds, inverses soybean meal (5.7%, alfalfa (43.9% and alfalfa (3.75% h-1 had lower soluble CP, insoluble potentially degradable CP and degradation rate than other feeds, respectively. There were differences (p<0.05 among test feeds in dry matter and crude protein degradability after several incubation times. There was strong coefficient of correlation between extent of in situ dry matter and crude protein degradation and in vitro dry matter and crude protein disappearance. The key protein parameters in the proposed Metabolizable protein system, quick digestible protein, slowly digestible protein and digestible undegradable protein are derived from measurements of the rates of degradation of feed proteins suspended in a dacron bag in the rumen. The Metabolizable protein of soybean meal (381 g kg-1 was numerically rather than the other feeds and for corn grain (86 g kg-1 was numerically less than the other feeds.

  15. In situ leach: technology and potential

    International Nuclear Information System (INIS)

    In-situ leach and solution mining are described with respect to uranium mining. In the technique, leaching fluids dissolve the mineral without having to remove the ore physically from its occurence. In-situ leach can produce uranium at lower costs than other methods. The factors which are important to achieve this are discussed. In-situ leach is only suitable for one type of uranium deposit, a roll-front deposit (deposited from moving groundwater) in a permeable sandstone that must be an aquifer (sandstone filled with water). It is difficult to predict the performance of an in-situ leach project; good engineering techniques are more important than in conventional mining. The processing and subsequent recovery of the uranium are described. Some of the technological improvements in the technique are discussed. The future development of the technique is considered. (U.K.)

  16. 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

  17. In situ measurement technique for simultaneous detection of K, KCl, and KOH vapors released during combustion of solid biomass fuel in a single particle reactor.

    Science.gov (United States)

    Sorvajärvi, Tapio; DeMartini, Nikolai; Rossi, Jussi; Toivonen, Juha

    2014-01-01

    A quantitative and simultaneous measurement of K, KCl, and KOH vapors from a burning fuel sample combusted in a single particle reactor was performed using collinear photofragmentation and atomic absorption spectroscopy (CPFAAS) with a time resolution of 0.2 s. The previously presented CPFAAS technique was extended in this work to cover two consecutive fragmentation pulses for the photofragmentation of KCl and KOH. The spectral overlapping of the fragmentation spectra of KCl and KOH is discussed, and a linear equation system for the correction of the spectral interference is introduced. The detection limits for KCl, KOH, and K with the presented measurement arrangement and with 1 cm sample length were 0.5, 0.1, and 0.001 parts per million, respectively. The experimental setup was applied to analyze K, KCl, and KOH release from 10 mg spruce bark samples combusted at the temperatures of 850, 950, and 1050 °C with 10% of O2. The combustion experiments provided data on the form of K vapors and their release during different combustion phases and at different temperatures. The measured release histories agreed with earlier studies of K release. The simultaneous direct measurement of atomic K, KCl, and KOH will help in the impact of both the form of K in the biomass and fuel variables, such as particle size, on the release of K from biomass fuels. PMID:24480273

  18. In situ investigation of the surface silvering of late Roman coins by combined use of high energy broad-beam and low energy micro-beam X-ray fluorescence techniques

    Energy Technology Data Exchange (ETDEWEB)

    Romano, F.P., E-mail: romanop@lns.infn.it [IBAM, CNR, Via Biblioteca 4, 95124 Catania (Italy); LNS, INFN, Via S. Sofia 62, 95123 Catania (Italy); Garraffo, S. [ITABC, CNR, Via Salaria km 29.300, 00016 Monterotondo, Roma (Italy); Pappalardo, L. [IBAM, CNR, Via Biblioteca 4, 95124 Catania (Italy); LNS, INFN, Via S. Sofia 62, 95123 Catania (Italy); Rizzo, F. [LNS, INFN, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Universita di Catania, Via S. Sofia 64, 95123 Catania (Italy)

    2012-07-15

    The compositional analysis of archeological metals performed with the X-ray Fluorescence technique (XRF) provides information on the ancient technology. One of the most interesting case-study concerns the techniques used by Romans for silvering the surface of coins. Different metallurgical processes have been suggested in previous studies. Recently the investigation has been addressed to the mercury-silvering and to its possible use in the mass-production of coins minted during the late period (after 294 AD). In the present paper the non-destructive investigation of the silvering process used for manufacturing the Roman nummi - the important typology of coin introduced by Diocletian in his monetary reform - is approached by the combined use of the standard X-Ray Fluorescence (XRF) and the low energy micro-X-Ray Fluorescence (LE-{mu}XRF) portable methods. The research was focused on the systematic determination of the mercury presence in a large number of samples and on its correlation with silver in the surface of the coins. 1041 Roman nummi belonging to the Misurata Treasure were analyzed in situ, at the Leptis Magna Museum (Al Khums, Libya). The treasure, composed of about 108 thousand silvered coins, gives the unique opportunity to study the Roman coinage in a wide interval of time (about 40 years in the period 294-333 AD) and in almost all the imperial mints operating in the Roman world. - Highlights: Black-Right-Pointing-Pointer Custom-building of a high energy broad-beam and a low energy micro-beam XRF Black-Right-Pointing-Pointer In situ analysis of the silvering methods in late Roman nummi with plated surfaces Black-Right-Pointing-Pointer The broad-beam XRF was applied for the detection of mercury traces in the coin alloy. Black-Right-Pointing-Pointer The low energy micro-XRF was used to scan the surface patina of the coins. Black-Right-Pointing-Pointer The correlation between mercury and silver at the coin surface was evidenced.

  19. Illumination Sufficiency Survey Techniques: In-situ Measurements of Lighting System Performance and a User Preference Survey for Illuminance in an Off-Grid, African Setting

    Energy Technology Data Exchange (ETDEWEB)

    Alstone, Peter; Jacobson, Arne; Mills, Evan

    2010-08-26

    Efforts to promote rechargeable electric lighting as a replacement for fuel-based light sources in developing countries are typically predicated on the notion that lighting service levels can be maintained or improved while reducing the costs and environmental impacts of existing practices. However, the extremely low incomes of those who depend on fuel-based lighting create a need to balance the hypothetically possible or desirable levels of light with those that are sufficient and affordable. In a pilot study of four night vendors in Kenya, we document a field technique we developed to simultaneously measure the effectiveness of lighting service provided by a lighting system and conduct a survey of lighting service demand by end-users. We took gridded illuminance measurements across each vendor's working and selling area, with users indicating the sufficiency of light at each point. User light sources included a mix of kerosene-fueled hurricane lanterns, pressure lamps, and LED lanterns.We observed illuminance levels ranging from just above zero to 150 lux. The LED systems markedly improved the lighting service levels over those provided by kerosene-fueled hurricane lanterns. Users reported that the minimum acceptable threshold was about 2 lux. The results also indicated that the LED lamps in use by the subjects did not always provide sufficient illumination over the desired retail areas. Our sample size is much too small, however, to reach any conclusions about requirements in the broader population. Given the small number of subjects and very specific type of user, our results should be regarded as indicative rather than conclusive. We recommend replicating the method at larger scales and across a variety of user types and contexts. Policymakers should revisit the subject of recommended illuminance levels regularly as LED technology advances and the price/service balance point evolves.

  20. Accuracy assessment of water vapour measurements from in-situ and remote sensing techniques during the DEMEVAP 2011 campaign at OHP

    Directory of Open Access Journals (Sweden)

    O. Bock

    2013-04-01

    Full Text Available The Development of Methodologies for Water Vapour Measurement (DEMEVAP project aims at assessing and improving humidity sounding techniques and establishing a reference system based on the combination of Raman lidars, ground-based sensors and GPS. Such a system may be used for climate monitoring, radiosonde bias detection and correction, satellite measurement calibration/validation, and mm-level geodetic positioning with Global Navigation Satellite Systems. A field experiment was conducted in September–October 2011 at Observatoire de Haute Provence. Two Raman lidars, a stellar spectrometer (SOPHIE, a differential absorption spectrometer (SAOZ, a sun photometer (AERONET, 5 GPS receivers and 4 types of radiosondes (Vaisala RS92, MODEM M2K2-DC and M10, and Meteolabor Snow-White participated in the campaign. A total of 26 balloons with multiple radiosondes were flown during 16 clear nights. This paper presents preliminary findings from the analysis of all these datasets. Several classical Raman lidar calibration methods are evaluated which use either Vaisala RS92 measurements, point capacitive humidity measurements, or GPS integrated water vapour (IWV measurements. A novel method proposed by Bosser et al. (2010 is also tested. It consists in calibrating the lidar measurements during the GPS data processing. The methods achieve a repeatability of 4–5%. A drift in the IGN-LATMOS Raman lidar calibration of 15% over the 45 days of the experiment is evidenced but not yet explained. When this drift is removed, the precision of the calibration factors improves to 2–3%. However, the variations in the absolute calibration factor between methods and types of reference data remain at the level of 7%. The intercomparison of radiosonde measurements shows good agreement between RS92 and Snow-White measurements up to 12 km. An overall dry bias is found in the measurements from both MODEM radiosondes. Investigation of situations with low RH values (<10% in the lower and middle troposphere reveals, on occasion, a lower RH detection limit in the Snow-White measurements compared to RS92 due to a saturation of the Peltier device. However, on other occasions, a dry bias is found in RS92, instead. Raman lidar water vapour measurements were useful to distinguish between which of the radiosondes was biased. On average, both RS92 and Snow-White measurements show a slight moist bias at night-time compared to GPS IWV, while the MODEM measurements show a large dry bias. The spectrometer IWV measurements contained a large bias that is currently under investigation. The sun photometer (daytime and calibrated Raman lidar (night-time IWV measurements showed excellent agreement with the GPS IWV measurements.

  1. Synthesis of Cu-rich, Al2O3-stabilized oxygen carriers using a coprecipitation technique: redox and carbon formation characteristics.

    Science.gov (United States)

    Imtiaz, Qasim; Kierzkowska, Agnieszka M; Broda, Marcin; Müller, Christoph R

    2012-03-20

    Chemical looping combustion (CLC) is an emerging, new technology for carbon capture and storage (CCS). Copper-based oxygen carriers are of particular interest due to their high oxygen carrying capacity and reactivity, low tendency for carbon deposition, and exothermic reduction reactions. In this work, CuO-based and Al(2)O(3)-stabilized oxygen carriers with high CuO loadings were developed using a coprecipitation technique. The cyclic redox performance of the synthesized oxygen carriers was evaluated at 800 °C in a laboratory-scale fluidized bed reactor using a reducing atmosphere comprising 10 vol. % CH(4) and 90 vol. % N(2). The CuO content in the oxygen carrier was found to increase with the pH value at which the coprecipitation was performed. The oxygen carrying capacity of the oxygen carrier containing 87.8 wt % CuO was found to be high (5.5 mmol O(2)/g oxygen carrier) and stable over 25 redox cycles. Increasing the CuO content further, i.e. > 90 wt %, resulted in materials which showed a decreasing oxygen carrying capacity with cycle number. It was also shown that the incorporation of K(+) ions in the oxygen carrier can avoid the formation of the spinel CuAl(2)O(4) and significantly reduce carbon deposition. PMID:22356662

  2. Estabilização de taludes marginais com técnicas de bioengenharia de solos no Baixo São Francisco / Riverbank stabilization with soil bioengineering techniques at the Lower São Francisco River

    Scientific Electronic Library Online (English)

    Francisco S. R., Holanda; Igor P. da, Rocha; Vandemberg S., Oliveira.

    2008-12-01

    Full Text Available Os taludes marginais no baixo curso do Rio São Francisco, dominados por solos de baixa coesão sofrem com o avanço da erosão que causa recuo da margem e assoreamento do canal. A proposta deste trabalho foi estudar a aplicação da bioengenharia de solos visando ao controle da erosão por meio da estabil [...] ização dos taludes marginais, para posterior recuperação da vegetação ciliar. A área experimental foi dividida em dois tratamentos com 3 repetições, sendo o tratamento sem uso de bioengenharia (testemunha) implantado à montante do fluxo da água e o tratamento com uso de bioengenharia, à jusante. A técnica de bioengenharia de solos foi caracterizada pela associação do geotêxtil Fibrax® 400 BF com gramínea Brachiaria decumbens, e retentores de sedimentos (Bermalongas®) ao longo da linha d'água. Para avaliação do comportamento do talude realizou-se levantamento topográfico planialtimétrico aos 30, 180, 360 e 540 dias de implantação do experimento. No tratamento sem proteção de bioengenharia (testemunha) ocorreram variações significativas no perfil topográfico, enquanto no talude protegido com bioengenharia ocorreram movimentos de massa pouco expressivos. Abstract in english The river banks of the Lower São Francisco River, which mostly present low cohesion soils, have suffered with the increase in erosion, leading to margin retreat and sedimentation. The purpose of this work was to study the application of a soil bioengineering technique in order to control the riverba [...] nk erosion by its stabilization aiming toward the riparian vegetation recovery. The experimental area was divided in two different assays, with three replications. The test assay (without the soil bioengineering technique) was installed upstream, and the assay with soil bioengineering was installed downsteam. The soil bioengineering technique was characterized by the association of the biotextile screen under the trade name Fibrax® 400BF, associated with Brachiaria decumbens grass and sediment retainers under the trade name Bermalonga®, installed along the river bank base. In order to evaluate the riverbank changes, direct topographic measures was used. The data was collected 30, 180, 360 and 540 days after the beginning of the study. At the assay without soil bioengineering protection, strong slope soil mass movement occurred. The opposite behavior occurred in the assay with soil bioengineering, with a very little soil movement.

  3. Application of the electrophoretic deposition technique for obtaining Yttria-stabilized zirconia tubes; Aplicacao da tecnica de deposicao eletroforetica para a obtencao de tubos ceramicos de zirconia-itria

    Energy Technology Data Exchange (ETDEWEB)

    Caproni, E.; Muccillo, R., E-mail: ecaproni@gmail.com, E-mail: muccillo@usp.br [Centro de Ciencia e Tecnologia de Materiais, Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2012-01-15

    The electrophoretic deposition (EPD) is recognized as the most versatile technique for processing particulate materials, due to low cost, deposition in minutes and forming of pieces with complex geometry shapes. In this work an experimental setup for the simultaneous conformation of 16 ceramic tubes by EPD was built. Bimodal submicron Yttria-stabilized zirconia particles were deposited into graphite electrodes, after suitably adjusting the rheological characteristics of the suspension in isopropanol. After graphite burning and YSZ sintering at 1500 deg C, the ceramic tubes were characterized by X-ray diffraction, scanning probe microscope, impedance spectroscopy and electrical response as a function of oxygen content. Small dense one end-closed ceramic tubes, fully stabilized in the cubic phase, were successfully obtained by the EPD technique, showing the ability of that technique for processing large quantities of tubular solid electrolytes with electrical response to different amounts of oxygen according to the Nernst law (author)

  4. Parâmetros de degradabilidade potencial dos componentes da parede celular das silagens de seis genótipos de sorgo (Sorghum bicolor (L.) Moench), na presença ou ausência de tanino no grão, avaliados pela técnica "in situ" / Potential degradability parameters of the cell wall compounds of six sorghum silage genotypes (Sorghum bicolor (L.) Moench), with or without tannin on grain, evaluated by "in situ" technique

    Scientific Electronic Library Online (English)

    Lívio Rribeiro, Molina; Norberto Mario, Rodriguez; Lúcio Carlos, Gonçalves; Iran, Borges; Breno Mourão de, Sousa.

    2003-10-01

    Full Text Available Para testar o efeito da presença de tanino no grão sobre os parâmetros de degradabilidade potencial dos componentes da parede celular de seis genótipos de sorgo para silagem, conduziu-se este experimento utilizando a técnica da degradabilidade "in situ". Quatro novilhos mestiços, canulados no rúmen, [...] foram utilizados. Os novilhos foram alimentados "ad libitum" duas vezes ao dia, individualmente, com feno de Tifton 85. Foram incubadas silagens de sorgo no estádio de grão leitoso, pertencentes a seis genótipos: BR 303, BR 304, BR 601e AG 2006 (sem tanino no grão); BR 700 e BR 701 (com tanino). Foram incubadas 5 g de amostra dentro de bolsas de náilon suspensas no rúmen, nos tempos: 6, 12, 24, 48, 72 e 96 horas. O tempo zero (t0) foi utilizado para cálculo da fração solúvel. A presença do tanino reduziu a extensão de degradação da fibra em detergente neutro (FDN) e da fibra em detergente ácido (FDA) nas silagens de sorgo BR 700 e BR 701. A degradabilidade potencial da FDN e da FDA foi reduzida pela presença do tanino. Não foi observado efeito depressivo do tanino sobre as taxas de degradação para nenhum nutriente, em nenhuma silagem testada. Abstract in english The aim of these experiment was to evaluate the effect of tannin on grain over potential degradability parameters of the cell wall compounds of six sorghum silage genotypes by "in situ" technique. Four crossbred steers, canulated in rumen, were used. The steers were fed "ad libitum" twice at day wit [...] h a diet comprised by Tifton 85 (Cynodon dactylon) hay. Six sorghum silage genotypes, harvested at milk stage, were incubated in the rumen: BR 303, BR 304, BR 601, and AG 2006 (without tannin on grain); BR 700, and BR 701 (with tannin on grain). Five grams of samples were incubated into nylon bags, and suspended in the rumen by times: 6, 12, 24, 48, 72, and 96 hours. The time zero (t0) was used to calculate the soluble fraction. Tannin decrease the extent of degradation of neutral detergent fiber (NDF), and acid detergent fiber (ADF) of BR 700 and BR 701 sorghum silages. The potential degradability of the NDF and ADF was reduced by tannin presence on grain. There was not effect of tannin on degradation rate of the cell wall compounds in anyone sorghum silage genotypes tested.

  5. Parâmetros de degradabilidade potencial dos componentes da parede celular das silagens de seis genótipos de sorgo (Sorghum bicolor (L. Moench, na presença ou ausência de tanino no grão, avaliados pela técnica "in situ" Potential degradability parameters of the cell wall compounds of six sorghum silage genotypes (Sorghum bicolor (L. Moench, with or without tannin on grain, evaluated by "in situ" technique

    Directory of Open Access Journals (Sweden)

    Lívio Rribeiro Molina

    2003-10-01

    Full Text Available Para testar o efeito da presença de tanino no grão sobre os parâmetros de degradabilidade potencial dos componentes da parede celular de seis genótipos de sorgo para silagem, conduziu-se este experimento utilizando a técnica da degradabilidade "in situ". Quatro novilhos mestiços, canulados no rúmen, foram utilizados. Os novilhos foram alimentados "ad libitum" duas vezes ao dia, individualmente, com feno de Tifton 85. Foram incubadas silagens de sorgo no estádio de grão leitoso, pertencentes a seis genótipos: BR 303, BR 304, BR 601e AG 2006 (sem tanino no grão; BR 700 e BR 701 (com tanino. Foram incubadas 5 g de amostra dentro de bolsas de náilon suspensas no rúmen, nos tempos: 6, 12, 24, 48, 72 e 96 horas. O tempo zero (t0 foi utilizado para cálculo da fração solúvel. A presença do tanino reduziu a extensão de degradação da fibra em detergente neutro (FDN e da fibra em detergente ácido (FDA nas silagens de sorgo BR 700 e BR 701. A degradabilidade potencial da FDN e da FDA foi reduzida pela presença do tanino. Não foi observado efeito depressivo do tanino sobre as taxas de degradação para nenhum nutriente, em nenhuma silagem testada.The aim of these experiment was to evaluate the effect of tannin on grain over potential degradability parameters of the cell wall compounds of six sorghum silage genotypes by "in situ" technique. Four crossbred steers, canulated in rumen, were used. The steers were fed "ad libitum" twice at day with a diet comprised by Tifton 85 (Cynodon dactylon hay. Six sorghum silage genotypes, harvested at milk stage, were incubated in the rumen: BR 303, BR 304, BR 601, and AG 2006 (without tannin on grain; BR 700, and BR 701 (with tannin on grain. Five grams of samples were incubated into nylon bags, and suspended in the rumen by times: 6, 12, 24, 48, 72, and 96 hours. The time zero (t0 was used to calculate the soluble fraction. Tannin decrease the extent of degradation of neutral detergent fiber (NDF, and acid detergent fiber (ADF of BR 700 and BR 701 sorghum silages. The potential degradability of the NDF and ADF was reduced by tannin presence on grain. There was not effect of tannin on degradation rate of the cell wall compounds in anyone sorghum silage genotypes tested.

  6. In situ TEM study of cubic zirconia implanted with caesium ions

    International Nuclear Information System (INIS)

    In situ transmission electron microscopy (TEM) observations were performed on yttria-stabilized zirconia during caesium (Cs) ion implantation at room temperature. Apparition of defect clusters is observed. The concentration of the latter increased with the Cs ion fluence. Until the higher fluence (2 x 1016 cm-2), nothing else was observed except the overlapping of these defect clusters. At the higher fluence, Cs ion implanted thin sample was annealed between 600 and 1200 K. Only the recrystallization of cubic zirconia occurs during annealing; no other compounds were formed. The TEM results are compared to previous results obtained from Rutherford backscattering and channelling ion beam analysis techniques

  7. Lightweight Mg-based composites with thermodynamically stable interfaces by in-situ combustion synthesis

    Science.gov (United States)

    Jo, Ilguk

    Lightweight Mg-based composites have been produced by in-situ combustion synthesis of the Al-Ti-C reaction system. The characteristics of the in-situ composites were investigated in terms of phase evolution and interfacial stability using various analysis techniques. The structural analysis results showed that full conversion of the Al-Ti-C reactants into spherical TiC reinforcements with sizes around 1mum was achieved by the combustion reaction. In-situ formed TiC had less oxygen and higher Al contents at the interface than ex-situ formed TiC; these clean interfaces with an Al layer on the reinforcements were shown to yield interfacial stability. For these reasons, the in-situ composites exhibited higher theoretical densities and also good mechanical properties compared with ex-situ produced composites. The interfacial characteristics of molten Mg with the Al-Ti-C reactants and the commercial TiC+Al substrates were evaluated using an infiltration technique under an argon atmosphere. Infiltration length increased with time at temperature, yielding activation energies (Ea) for each system. The value of Ea for the Al-Ti-C system (307.31kJ/mol) is lower than that for the other system (350.84kJ/mol); the high Ea value indicates that the infiltration is not a simple viscosity-controlled phenomenon but involves a chemical reaction. Formation of the Al3Ti phase was observed from the crystal structural analysis of the infiltrated area; thus, existence of reaction promoting the wetting of Mg. The phase evolution, reaction mechanism and kinetics of the Al-Ti-C reaction were studied using DSC and HT-XRD. It was confirmed that, along with the melting of Al, there was formation of Al3Ti by reaction between Al and Ti. A detailed structural analysis indicates that, the reaction mechanism involves melting of Al followed by formation and growth of Al 3Ti, which then contacts the graphite powder and initiates the combustion reaction. The effect of important process parameters, such as the Al content and the reactant sizes, on the microstructure of the resulting in-situ composites is discussed. Feasibility and castability of the composites were investigated by high pressure die casting the composite preforms into automotive parts and durability tests were conducted on the cast parts.

  8. Application of the 15N-Gas Flux method for measuring in situ N2 and N2O fluxes due to denitrification in natural and semi-natural terrestrial ecosystems and comparison with the acetylene inhibition technique

    Directory of Open Access Journals (Sweden)

    F. Sgouridis

    2015-08-01

    Full Text Available Soil denitrification is considered the most un-constrained process in the global N cycle due to uncertain in situ N2 flux measurements, particularly in natural and semi-natural terrestrial ecosystems. 15N tracer approaches can provide in situ measurements of both N2 and N2O simultaneously, but their use has been limited to fertilised agro-ecosystems due to the need for large 15N additions in order to detect 15N2 production against the high atmospheric N2. For 15N-N2 analyses, we have used an "in house" laboratory designed and manufactured N2 preparation instrument which can be interfaced to any commercial continuous flow isotope ratio mass spectrometer (CF-IRMS. The N2 prep unit has gas purification steps, a copper based reduction furnace, and allows the analysis of small gas injection volumes (4 ?L for 15N-N2 analysis. For the analysis of N2O, an automated Tracegas Pre-concentrator (Isoprime Ltd coupled to an IRMS was used to measure the 15N-N2O (4 mL gas injection volume. Consequently, the coefficient of variation for the determination of isotope ratios for N2 in air and in standard N2O (0.5 ppm was better than 0.5 %. The 15N Gas-Flux method was adapted for application in natural and semi-natural land use types (peatlands, forests and grasslands by lowering the 15N tracer application rate to 0.04–0.5 kg 15N ha?1. For our chamber design (volume / surface = 8:1 and a 20 h incubation period, the minimum detectable flux rates were 4 ?g N m?2 h?1 and 0.2 ng N m?2 h?1 for the N2 and N2O fluxes respectively. The N2 flux ranged between 2.4 and 416.6 ?g N m?2 h?1, and the grassland soils showed on average 3 and 14 times higher denitrification rates than the woodland and organic soils respectively. The N2O flux was on average 20 to 200 times lower than the N2 flux, while the denitrification product ratio (N2O/N2 + N2O was low, ranging between 0.03 and 13 %. Total denitrification rates measured by the acetylene inhibition technique under the same field conditions correlated (r = 0.58 with the denitrification rates measured under the 15N Gas-Flux method but were underestimated by a factor of 4 and this was attributed to the incomplete inhibition of N2O reduction to N2 under relatively high soil moisture content. The results show that the 15N Gas-Flux method can be used for quantifying N2 and N2O production rates in natural terrestrial ecosystems, thus significantly improving our ability to constrain ecosystem N budgets.

  9. Application of the 15N-Gas Flux method for measuring in situ N2 and N2O fluxes due to denitrification in natural and semi-natural terrestrial ecosystems and comparison with the acetylene inhibition technique

    Science.gov (United States)

    Sgouridis, F.; Ullah, S.; Stott, A.

    2015-08-01

    Soil denitrification is considered the most un-constrained process in the global N cycle due to uncertain in situ N2 flux measurements, particularly in natural and semi-natural terrestrial ecosystems. 15N tracer approaches can provide in situ measurements of both N2 and N2O simultaneously, but their use has been limited to fertilised agro-ecosystems due to the need for large 15N additions in order to detect 15N2 production against the high atmospheric N2. For 15N-N2 analyses, we have used an "in house" laboratory designed and manufactured N2 preparation instrument which can be interfaced to any commercial continuous flow isotope ratio mass spectrometer (CF-IRMS). The N2 prep unit has gas purification steps, a copper based reduction furnace, and allows the analysis of small gas injection volumes (4 ?L) for 15N-N2 analysis. For the analysis of N2O, an automated Tracegas Pre-concentrator (Isoprime Ltd) coupled to an IRMS was used to measure the 15N-N2O (4 mL gas injection volume). Consequently, the coefficient of variation for the determination of isotope ratios for N2 in air and in standard N2O (0.5 ppm) was better than 0.5 %. The 15N Gas-Flux method was adapted for application in natural and semi-natural land use types (peatlands, forests and grasslands) by lowering the 15N tracer application rate to 0.04-0.5 kg 15N ha-1. For our chamber design (volume / surface = 8:1) and a 20 h incubation period, the minimum detectable flux rates were 4 ?g N m-2 h-1 and 0.2 ng N m-2 h-1 for the N2 and N2O fluxes respectively. The N2 flux ranged between 2.4 and 416.6 ?g N m-2 h-1, and the grassland soils showed on average 3 and 14 times higher denitrification rates than the woodland and organic soils respectively. The N2O flux was on average 20 to 200 times lower than the N2 flux, while the denitrification product ratio (N2O/N2 + N2O) was low, ranging between 0.03 and 13 %. Total denitrification rates measured by the acetylene inhibition technique under the same field conditions correlated (r = 0.58) with the denitrification rates measured under the 15N Gas-Flux method but were underestimated by a factor of 4 and this was attributed to the incomplete inhibition of N2O reduction to N2 under relatively high soil moisture content. The results show that the 15N Gas-Flux method can be used for quantifying N2 and N2O production rates in natural terrestrial ecosystems, thus significantly improving our ability to constrain ecosystem N budgets.

  10. Operational Review of the First Wireline In Situ Stress Test in Scientific Ocean Drilling

    Directory of Open Access Journals (Sweden)

    Casey Moore

    2012-04-01

    Full Text Available Scientific ocean drilling’s first in situ stress measurement was made at Site C0009A during Integrated Ocean Drilling Program (IODP Expedition 319 as part of Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE Stage 2. The Modular Formation Dynamics Tester (MDT, Schlumbergerwireline logging tool was deployed in riser Hole C0009A to measure in situ formation pore pressure, formation permeability (often reported as mobility=permeability/viscosity, and the least principal stress (S3 at several isolated depths (Saffer et al., 2009; Expedition 319 Scientists, 2010. The importance of in situ stress measurements is not only for scientific interests in active tectonic drilling, but also for geomechanical and well bore stability analyses. Certain in situ tools were not previously available for scientific ocean drilling due to the borehole diameter and open hole limits of riserless drilling. The riser-capable drillship, D/V Chikyu,now in service for IODP expeditions, allows all of the techniques available to estimate the magnitudes and orientations of 3-D stresses to be used. These techniques include downhole density logging for vertical stress, breakout and caliper log analyses for maximum horizontal stress, core-based anelastic strain recovery (ASR, used in the NanTroSEIZE expeditions in 2007–2008, and leak-off test (Lin et al., 2008 and minifrac/hydraulic fracturing (NanTroSEIZE Expedition319 in 2009. In this report, the whole operational planning process related to in situ measurements is reviewed, and lessons learned from Expedition 319 are summarized for efficient planning and testing in the future.

  11. In Situ Imaging of Atomic Quantum Gases

    Science.gov (United States)

    Hung, Chen-Lung; Chin, Cheng

    2015-09-01

    One exciting progress in recent cold atom experiments is the development of high resolution, in situ imaging techniques for atomic quantum gases.1-3 These new powerful tools provide detailed information on the distribution of atoms in a trap with resolution approaching the level of single atom and even single lattice site, and complement the welldeveloped time-of-flight method that probes the system in momentum space. In a condensed matter analogy, this technique is equivalent to locating electrons of a material in a snap shot. In situ imaging has offered a new powerful tool to study atomic gases and inspired many new research directions and ideas. In this chapter, we will describe the experimental setup of in situ absorption imaging, observables that can be extracted from the images, and new physics that can be explored with this technique.

  12. Stability of the Kepler-11 system and its origin

    Energy Technology Data Exchange (ETDEWEB)

    Mahajan, Nikhil; Wu, Yanqin [Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4 (Canada)

    2014-11-01

    A significant fraction of Kepler systems are closely packed, largely coplanar, and circular. We study the stability of a six-planet system, Kepler-11, to gain insights on the dynamics and formation history of such systems. Using a technique called 'frequency maps' as fast indicators of long-term stability, we explore the stability of the Kepler-11 system by analyzing the neighborhood space around its orbital parameters. Frequency maps provide a visual representation of chaos and stability, and their dependence on orbital parameters. We find that the current system is stable, but lies within a few percent of several dynamically dangerous two-body mean-motion resonances. Planet eccentricities are restricted below a small value, ?0.04, for long-term stability, but planet masses can be more than twice their reported values (thus allowing for the possibility of mass loss by past photoevaporation). Based on our frequency maps, we speculate on the origin of instability in closely packed systems. We then proceed to investigate how the system could have been assembled. The stability constraints on Kepler-11 (mainly eccentricity constraints) suggest that if the system were assembled in situ, a dissipation mechanism must have been at work to neutralize the eccentricity excitation. On the other hand, if migration was responsible for assembling the planets, there has to be little differential migration among the planets to avoid them either getting trapped into mean motion resonances, or crashing into each other.

  13. Quantifying the contribution of above - and below ground N in legumes to soil N pools and subsequent maize in an improved fallow system using in situ 15N labelling techniques in Western Kenya

    International Nuclear Information System (INIS)

    A field experiment was undertaken in western Kenya to (i) determine the amount of legume below ground biomass N at a given time without physically disturbing the soil, (ii) study 15N recovery by maize from decomposing labelled roots of legume fallows and assess interactions occurring when mixed with the above ground fallow biomass and (iii) determine the distribution of excess 15N in water stable aggregates, free organic matter and the clay + silt fraction. One year old Sesbania sesban, Calliandra calothyrsus, Senna spectabilis, Cajanus cajan, Crotalaria grahamiana and Tephrosia vogelii were enriched in situ with labelled ammonium sulphate [(15NH4)2SO4] through stem injection techniques. The total above ground dry matter (DM) of the legumes varied between 589 g tree1 for Senna and 1572 g tree1 for Calliandra. The shoot to root ratio ranged from 1.2 for Senna to 3.1 for Calliandra. Total above ground N ranged from 8.6 to 23.1 g tree1 and was highest for Calliandra and lowest for Senna. Cajanus, Calliandra, Crotalaria and Tephrosia exhibited similar proportions of 15N enrichment in the leaves and wood, but Senna allocated more 15N to wood as compared to leaves. Total above ground 15N recovery ranged from 49% for Crotalaria to 69% for Tephrosia indicating that 27 to 50% is potentially allocated to the roots. About 2.5 to 7.4% of 15N is potentially recovered from roots less than 5 mm. A large proportion (39%) of below ground N became protected in water stable meso- and macroaggregates while around 20% was associated with the clay-silt sized fraction. This contrasts with the fate of 15N labelled foliage litter from which only 31% was found in aggregates, but a larger proportion remained in the free organic fraction, suggesting an important role of roots in aggregate formation. 15N recoveries of below ground N in the catch crop were small suggesting that these inputs play a more important role in soil structure rather than in nutrient supply. (author)

  14. In situ activated nanostructured platform for oxidized glutathione biosensing

    International Nuclear Information System (INIS)

    Highlights: ? New nanostructured platform for GSSG determination based on multi walled carbon nanotubes and chitosan. ? The redox mediator activated in situ showed a high electrocatalytic constant for NADH electrooxidation. ? An amperometric method for GSSG determination based on NADH consumption has been presented for the first time. -- Abstract: This work describes the construction of a biosensor for glutathione disulfide (GSSG) based on a nanostructured platform composed by MWCNTs, chitosan (CHIT) and the redox mediator 3,5-dinitrobenzoic acid. The dispersion of MWCNTs and CHIT showed a good stability and was used to modify the glassy carbon electrode (GCE). The nanostructured platform was characterized by scanning electron microscopy (SEM) and electrochemical techniques. The R-NO/R-NHOH redox couple was electrogenerated in situ by cycling the potential between 0.2 and ?0.4 V vs. SCE. After activating the nanostructured platform, glutathione reductase was easily immobilized on the electrode surface by using glutaraldehyde as functional linker. The biosensor performance was optimized in terms of amount of enzyme, effect of CHIT concentration and NADH amount. Under optimized conditions, the biosensor response for GSSG sensing was linear from 2.0 up to 35 ?mol L?1 with detection and quantification limits achieving values of 0.6 and 2.0 ?mol L?1, respectively and sensitivity of 6.24 mA L mol?1. The apparent Michaelis–Menten constant (KMapp) obtained by amperometry for the immobilized glutathione reductase on the nanostructured platform was 60 ?mol L?1

  15. In situ polymerization of vinyl monomers in polyester yarns

    International Nuclear Information System (INIS)

    The effects of a pretreatment of polyester (PET) yarns with a strongly interacting solvent such as dimethylformamide (DMF) on vinyl monomer incorporation were investigated. When the DMF pretreatment is carried out at high temperatures (above 1200C), the swollen PET structure is stabilized by solvent-induced secondary crystallization. This substrate is highly suitable for the incorporation of vinyl monomers. In situ polymerization of vinyl monomers in DMF-treated PET was investigated using chemical and ?-irradiation polymerization techniques, both in the presence and in the absence of excess monomer outside the PET fibers. When polymerization was carried out in a system in which a constant supply of free radicals was available from the outside of the PET fibers, lower initiator concentrations and smaller ?-irradiation doses were necessary. These results are attributed to a low efficiency of the initiator inside the PET fiber due to mobility restrictions. Water uptake and moisture regain of PET yarns containing poly(hydroxyethyl methacrylate) and poly(acrylic acid) were also investigated. When most of the vinyl polymer was inside the PET fiber, water absorption was limited. The changes in mechanical properties of the PET yarns resulting from the DMF pretreatment were partially reversed by in situ polymerization of vinyl monomers

  16. Thermal stability and crystallization kinetics of metallic glasses Fe80-xTxB20 as studied by EEE and DTA techniques

    International Nuclear Information System (INIS)

    Thermal stability and crystallization kinetics of amorphous ribbons Fe80-xTxB20 (T-transition metal) have been investigated by differential thermal analysis and by measuring the temperature dependencies of the intensity of photostimulated exoelectron emission. For the surface crystallization both the crystallization temperatures and activation energies determined by the Ozawa method are distinctly lower than those for cristallization in bulk

  17. Task plan to evaluate the effectiveness of in situ grouting of an ORNL waste burial trench with a cement-based grout

    International Nuclear Information System (INIS)

    This task will demonstrate the feasibility of using an in situ grouting technique with a particulate-grout formulation as a closure action to stabilize waste trenches in Solid Waste Storage Area (SWSA) 6. It also supports technology development for closure of other SWSAs. A particulate grout will be formulated using cement-bentonite and fly ash from a coal-fired power plant. The grout solids will be dry-blended, mixed with water, and injected (using ?5 to 10 lb/in.2 pressure) into five injection wells per trench. After 28 days for setting, soil penetration resistance and hydraulic conductivity measurements will be repeated for comparison to pregrouting measurements. The primary objective of this task is to demonstrate the feasibility and effectiveness of the in situ injection of a particulate grout into waste burial trenches. Effectiveness is defined here as increased trenched stability (characterized by trench penetration resistance tests) and decreased potential for leachate migration (characterized by hydraulic conductivity tests)

  18. In situ vitrification large-scale operational acceptance test analysis

    International Nuclear Information System (INIS)

    A thermal treatment process is currently under study to provide possible enhancement of in-place stabilization of transuranic and chemically contaminated soil sites. The process is known as in situ vitrification (ISV). In situ vitrification is a remedial action process that destroys solid and liquid organic contaminants and incorporates radionuclides into a glass-like material that renders contaminants substantially less mobile and less likely to impact the environment. A large-scale operational acceptance test (LSOAT) was recently completed in which more than 180 t of vitrified soil were produced in each of three adjacent settings. The LSOAT demonstrated that the process conforms to the functional design criteria necessary for the large-scale radioactive test (LSRT) to be conducted following verification of the performance capabilities of the process. The energy requirements and vitrified block size, shape, and mass are sufficiently equivalent to those predicted by the ISV mathematical model to confirm its usefulness as a predictive tool. The LSOAT demonstrated an electrode replacement technique, which can be used if an electrode fails, and techniques have been identified to minimize air oxidation, thereby extending electrode life. A statistical analysis was employed during the LSOAT to identify graphite collars and an insulative surface as successful cold cap subsidence techniques. The LSOAT also showed that even under worst-case conditions, the off-gas system exceeds the flow requirements necessary to maintain a negative pressure on the hood covering the area being vitrified. The retention of simulated radionuclides and chemicals in the soil and off-gas system exceeds requirements so that projected emissions are one to two orders of magnitude below the maximum permissible concentrations of contaminants at the stack

  19. In situ and ex situ characterization studies of transition metal containing nanoporous catalysts

    OpenAIRE

    Martis, M.

    2011-01-01

    The research within this thesis has concentrated around characterization of nanoporous catalysts with metals incorporated or substituted inside the framework, and inside the cavities as small clusters, and in very low concentrations. The main objective has been to advance the understanding of the structure and active sites, and relate them to their catalytic properties through the use of combination in situ and ex situ methods and in some cases combination with optical spectroscopic technique...

  20. Utilisation de la DSC pour la caractérisation de la stabilité des émulsions eau dans pétrole Use of the Dsc Technique to Characterize Water-In-Crude Oil Emulsions Stability

    Directory of Open Access Journals (Sweden)

    Dalmazzone C.

    2006-12-01

    Full Text Available La technique DSC (Differential Scanning Calorimetry a été appliquée à l'étude des émulsions eau dans pétrole, qui se forment naturellement après un déversement de pétrole en mer. Ces émulsions, également appelées mousses au chocolat , peuvent contenir de 50 à 80% d'eau et se présentent souvent sous la forme d'un produit visqueux, difficile à récupérer mécaniquement, à traiter ou à brûler. Il est par conséquent important de pouvoir estimer leur stabilité pour optimiser le choix du traitement. Un grand nombre de techniques, généralement fondées sur l'analyse de la distribution de tailles de gouttes, peuvent être utilisées pour estimer la stabilité d'une émulsion. Malheureusement, la plupart ne sont pas adaptées à l'étude des émulsions eau dans huile opaques. La méthode la plus utilisée pour caractériser la stabilité de ce type d'émulsions est le bottle test. Elle consiste à mesurer la séparation de phases en fonction du temps. Ce test est la source d'une quantité d'informations appréciables quant à la stabilité de l'émulsion et à la qualité de la phase aqueuse séparée, mais il reste très empirique. La technique DSC est généralement utilisée pour déterminer la composition des émulsions eau dans huile, car elle permet de distinguer l'eau libre de l'eau émulsifiée. Cette étude a montré qu'il s'agit d'une technique très utile qui permet à la fois l'étude de l'évolution de la taille des gouttes dans l'émulsion, et une détermination précise de la quantité d'eau. The DSC technique (Differential Scanning Calorimetry was applied to the study of water-in-crude oil emulsions, which naturally form after an oil spill. The resulting emulsions contain between 50 and 80% seawater and they are often heavy materials, hard to recover mechanically, treat or burn. It is therefore important to assess their stability in order to optimize their treatments. A great variety of techniques are available for the assessment of emulsions stability. They are generally based on the analysis of the droplets size distribution. Unfortunately, most of the usual techniques can not be applied to opaque water-in-oil emulsions. The most useful method to characterize the stability of emulsions is of course the bottle test . It consists in monitoring the extent of phase separation with time. This type of test provides a significant amount of information relating to both the stability of the emulsion phase and the clarity of the separated water, but it is very empirical. The DSC technique is generally used to determine the composition of water-in-oil emulsions. It is the only technique capable of distinguishing free water from emulsified water. It was shown in this study that it is a very useful technique, which allows the study of the evolution of the droplet size distribution as well as a precise determination of the water content.

  1. An investigation into the accuracy, stability and parallel performance of a highly stable explicit technique for stiff reaction-transport PDEs

    Energy Technology Data Exchange (ETDEWEB)

    Franz, A., LLNL

    1998-02-17

    The numerical simulation of chemically reacting flows is a topic, that has attracted a great deal of current research At the heart of numerical reactive flow simulations are large sets of coupled, nonlinear Partial Differential Equations (PDES). Due to the stiffness that is usually present, explicit time differencing schemes are not used despite their inherent simplicity and efficiency on parallel and vector machines, since these schemes require prohibitively small numerical stepsizes. Implicit time differencing schemes, although possessing good stability characteristics, introduce a great deal of computational overhead necessary to solve the simultaneous algebraic system at each timestep. This thesis examines an algorithm based on a preconditioned time differencing scheme. The algorithm is explicit and permits a large stable time step. An investigation of the algorithm`s accuracy, stability and performance on a parallel architecture is presented

  2. Zebrafish Whole-Mount In Situ Hybridization Followed by Sectioning

    DEFF Research Database (Denmark)

    Doganli, Canan; Nyengaard, Jens Randel; Lykke-Hartmann, Karin

    2016-01-01

    In situ hybridization is a powerful technique used for locating specific nucleic acid targets within morphologically preserved tissues and cell preparations. A labeled RNA or DNA probe hybridizes to its complementary mRNA or DNA sequence within a sample. Here, we describe RNA in situ hybridization protocol for whole-mount zebrafish embryos.

  3. Stability Study of Filtering Techniques in Pictures of mini-MIAS Database; Estudio de Estabilidad de Tecnicas de Filtrado en Imagenes de la Base de Datos mini-MIAS

    Energy Technology Data Exchange (ETDEWEB)

    Parcero, E.; Vidal, V.; Verdu, G.; Mayo, P.

    2014-07-01

    The study of filtering techniques applied to medical imaging is particularly important because it can be decisive for an accurate diagnosis. This work aims to study the stability of Fuzzy Peer Group Averaging filter when applied to mammographic images of different nature in relation to the type of tissue abnormality found and diagnosis. The results show that the filter is effective, because obtained a PSNR value of 27 by comparing the filtered image with the original, and a value of 17 by comparing the filtered image with contaminated with noise. Also show that the filter will behave properly regardless of the image characteristics. (Author)

  4. Acid Pit Stabilization Project (Volume 1 - Cold Testing) and (Volume 2 - Hot Testing)

    International Nuclear Information System (INIS)

    During the summer and fall of Fiscal Year 1997, a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Treatability Study was performed at the Idaho National Engineering and Environmental Laboratory. The study involved subsurface stabilization of a mixed waste contaminated soil site called the Acid Pit. This study represents the culmination of a successful technology development effort that spanned Fiscal Years 1994-1996. Research and development of the in situ grout stabilization technique was conducted. Hardware and implementation tech