WorldWideScience

Sample records for situ stabilization technique

  1. New Technique for Soil Reclamation and Conservation: In Situ Stabilization of Trace Elements in Contaminated Soils

    OpenAIRE

    Negim, Osama

    2009-01-01

    L'accumulation de métaux toxiques dans le sol est principalement héritée de matériaux parents ou d'éléments résultant de l'activité humaine. Par conséquent, de nouvelles techniques sont en cours d'élaboration pour remédier à ces contaminations dans les sols pollués, telles que la phytoremédiation et la stabilisation in situ. La stabilisation in situ est une technique commune de réduction des effets négatifs des métaux et métalloïdes, tels que As, Cr, Cu, Cd et Zn dans les sols contaminés par ...

  2. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Sheng Sam; Goldberg, Kenneth A.; Yashchuk, Valeriy V.; Celestre, Richard; McKinney, Wayne R.; Morrison, Gregory; Macdougall, James; Mochi, Iacopo; Warwick, Tony

    2010-09-15

    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.

  6. 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.

  7. In-situ synchrotron diffraction and digital image correlation technique for characterizations of retained austenite stability in low-alloyed transformation induced plasticity steel

    International Nuclear Information System (INIS)

    Direct measurement and quantification of phase transformation in a low-alloyed transformation induced plasticity steels depending on the tensile load as well as determination of the real true stress and true strain values were carried out in-situ using high energy synchrotron radiation. Digital image correlation technique was used to quantify more precisely the true strain values. The aim of the work was to obtain a better understanding of the phase transformation of commercial low-alloyed transformation induced plasticity steel depending on the true strain and true stress values.

  8. 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

  9. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-09-01

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

  11. 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

  12. Chemoport anchoring the in situ technique

    Directory of Open Access Journals (Sweden)

    Krishnamachar Harish

    2011-08-01

    Full Text Available Chemoports are subcutaneously placed long term central venous access devices usually inserted under local anaesthesia. Rare complications include port inversion or flip over. These can be prevented by anchoring the port to the tissues at its base. We describe an in situ technique of port anchoring. Here, the port is first fixed temporarily to the overlying skin by Huber needle, thus facilitating placement of fixing sutures without port manipulation. The described technique is safe and we have not encountered complications. In addition, ex - planting the port was easier due to the use of delayed absorbable sutures. It is safer to anchor the port even if the port pocket ensures that the port fits in snugly. This described technique results in minimal manipulation of portcatheter system thereby ensuring that the catheter tip which is properly placed remains unaltered.

  13. 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.

  14. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Allan, M.L.

    1996-06-01

    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.

  16. 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

  17. 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.)

  18. 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.

  19. 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.

  20. In situ uranium stabilization by microbial metabolites

    International Nuclear Information System (INIS)

    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 >106 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

  1. Review of subsidence and stabilization techniques

    International Nuclear Information System (INIS)

    In Britain the damage caused by underground coal mining operations approximates to about 100 million pounds Sterling per annum, most of the damage resulting from longwall mining operations. Causes of subsidence can be attributed to the following factors: (1) roof failure (2) pillar failure (3) floor movements. Currently, in Britain, the mining industry is undergoing a state of decline for economic reasons. Consequently, the number of old coal sites available for development schemes has increased. Therefore, the problems associated with subsidence can be segregated into two parts. The first being the mitigation of the effects of subsidence on structures on actively mined areas. The second being the stabilization and rehabilitation of ground over and around old mine sites for new development schemes. In the former case the stabilization techniques employed may be local or global, depending on the problems encountered in any particular area. In the latter case, generally, grouting techniques are employed. This paper aims to review the causes of subsidence and the techniques used to minimize its effect on structures. Also, more economic alternative methods of ground stabilization techniques are described and proposed, to be used in this area of ground engineering

  2. 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.

  3. 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

  4. 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

  5. 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

  6. 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.

  7. A novel natural analog in situ stabilization agent

    International Nuclear Information System (INIS)

    This report summarizes the laboratory-scale test results on a synthetic analog of natural hematite cement for potential as an in situ treatment and stabilization agent for buried hazardous and radioactive waste. The concept is based on the principle that the ideal waste isolation materials are synthetic analogs of those natural encapsulating materials (cements), which are in equilibrium with the environment in which they occur. If equilibrium is achieved, then such materials will remain intact as long as the natural environment remains unchanged. The specific waste application is long-term stabilization of transuranic-contaminated waste pits and trenches at the Idaho National Engineering Laboratory (INEL). Six properties of the natural analog agent and resulting wasteforms are discussed to access the agent's effectiveness and implementability: hydraulic conductivity; compressive strength; mineralogy and microstructure; compatibility with possible waste materials, nitrates, machine cutting oil, and metallic iron; leachability of hazardous metals; and field application parameters. Data indicated that the iron waste encapsulation materials tested are appropriate choices for buried waste mixed with INEL soil. Iron oxide/gypsum INEL soil wasteforms have hydraulic conductivity values close to the regulatory limit. Wasteforms with soil and wastes have compressive strength greater than the regulatory minimum. Gypsum/iron oxide removes hazardous metals from solution by adsorption and would pass Toxicity Characteristic Leaching Procedure limits for most toxic metals. It appears to be chemically and physically inert with respect to the bulk of the waste materials likely to be found at INEL, and has properties conducive to jet grouting

  8. In Situ Study of Thermal Stability of Copper Oxide Nanowires at Anaerobic Environment

    OpenAIRE

    Lihui Zhang; Qiong Feng; Anmin Nie; Jiabin Liu; Hongtao Wang; Youtong Fang

    2014-01-01

    Many metal oxides with promising electrochemical properties were developed recently. Before those metal oxides realize the use as an anode in lithium ion batteries, their thermal stability at anaerobic environment inside batteries should be clearly understood for safety. In this study, copper oxide nanowires were investigated as an example. Several kinds of in situ experiment methods including in situ optical microscopy, in situ Raman spectrum, and in situ transmission electron microscopy wer...

  9. Insights into hydrophobic molecule release from polyelectrolyte multilayer films using in situ and ex situ techniques.

    Science.gov (United States)

    Shin, Yongjin; Cheung, Weng Hou; Ho, Tracey T M; Bremmell, Kristen E; Beattie, David A

    2014-10-28

    We report on the loading and release of curcumin (a hydrophobic polyphenol with anti-inflammatory and anti-bacterial properties) from polyelectrolyte multilayers composed of poly(diallyldimethylammonium chloride) (PDADMAC) and poly(sodium 4-styrenesulfonate) (PSS). We have used the in situ techniques of attenuated total reflectance (ATR) FTIR spectroscopy and quartz crystal microbalance with dissipation monitoring (QCM-D) to study the formation of the PEM and the incorporation of curcumin, providing direct evidence of the incorporation, in terms of molecular vibrations and gravimetric detection. The release of curcumin was followed using ex situ measurements of UV-visible spectroscopy of PEM films on quartz plates, in addition to in situ ATR FTIR measurements. Release was studied as a function of salt concentration of the release solution (0.001 M NaCl; 1 M NaCl). UV-visible spectroscopy indicated that salt concentration of the release solution had a major impact on release rates, with higher salt giving faster/more extensive release. However, prolonged timescale immersion and monitoring with UV-visible spectroscopy indicated that sample dehydration/rehydration cycling (required to measure UV absorbance) was responsible for the release of curcumin, rather than immersion time. In situ measurements of release kinetics with ATR FTIR confirmed that release does not occur spontaneously while the multilayer remains hydrated. PMID:25226281

  10. 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.

  11. Review of in situ derivatization techniques for enhanced bioanalysis using liquid chromatography with mass spectrometry.

    Science.gov (United States)

    Baghdady, Yehia Z; Schug, Kevin A

    2016-01-01

    Accurate and specific analysis of target molecules in complex biological matrices remains a significant challenge, especially when ultra-trace detection limits are required. Liquid chromatography with mass spectrometry is often the method of choice for bioanalysis. Conventional sample preparation and clean-up methods prior to the analysis of biological fluids such as liquid-liquid extraction, solid-phase extraction, or protein precipitation are time-consuming, tedious, and can negatively affect target recovery and detection sensitivity. An alternative or complementary strategy is the use of an off-line or on-line in situ derivatization technique. In situ derivatization can be incorporated to directly derivatize target analytes in their native biological matrices, without any prior sample clean-up methods, to substitute or even enhance the extraction and preconcentration efficiency of these traditional sample preparation methods. Designed appropriately, it can reduce the number of sample preparation steps necessary prior to analysis. Moreover, in situ derivatization can be used to enhance the performance of the developed liquid chromatography with mass spectrometry-based bioanalysis methods regarding stability, chromatographic separation, selectivity, and ionization efficiency. This review presents an overview of the commonly used in situ derivatization techniques coupled to liquid chromatography with mass spectrometry-based bioanalysis to guide and to stimulate future research. PMID:26496130

  12. 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

  13. 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.

  14. Review and prospect for uranium mining technique in-situ leaching in China

    International Nuclear Information System (INIS)

    The author presents the history and current situation of China uranium mining in-situ leaching, reviews uranium mining technique of in-situ leaching, poses a question for study and solution in development of in-situ leaching, and looks forward to resources and bright future of uranium mining in-situ leaching

  15. 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

  16. 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

  17. 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.

  18. 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)

  19. 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)

  20. 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.

  1. 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).

  2. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Heiser, J.; Fuhrmann, M. [Brookhaven National Lab., Upton, NY (United States)

    1997-09-01

    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.

  4. 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.

  5. Temperature-dependent properties of silver-poly(methylmethacrylate) nanocomposites synthesized by in-situ technique.

    Science.gov (United States)

    Singho, Noorsaiyyidah Darman; Johan, Mohd Rafie; Lah, Nurul Akmal Che

    2014-01-01

    Ag/PMMA nanocomposites were successfully synthesized by in-situ technique. Transmission electron microscopy (TEM) images show that the particles are spherical in shape and their sizes are dependent on temperature. The smallest particle achieved high stability as indicated from Zeta sizer analysis. The red shift of surface plasmon resonance (SPR) indicated the increases of particle sizes. X-ray diffraction (XRD) patterns exhibit a two-phase (crystalline and amorphous) structure of Ag/PMMA nanocomposites. The complexation of Ag/PMMA nanocomposites was confirmed using Raman spectroscopy. Fourier transform infrared spectroscopy spectra confirmed that the bonding was dominantly influenced by the PMMA and DMF solution. Finally, thermogravimetric analysis (TGA) results indicate that the total weight loss increases as the temperature increases. PMID:24450850

  6. 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...

  7. In Situ Mercury Stabilization (ISMS) Treatment: Technology Maturation Project Phase I Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Kalb,P.D.; Milian, L.

    2008-03-01

    Mercury (Hg) was used to separate lithium-6 isotope for weapons production at the Y-12 Plant in Oak Ridge in the 1950s and 1960s. As much as two million pounds of elemental mercury was 'lost' or unaccounted for and a large portion of that material is believed to have entered the environment. The DOE site office in Oak Ridge has identified Hg pollution in soils, sediments, and streams as the most significant environmental challenge currently faced. In industry, large amounts of mercury have been used to manufacture products (e.g., fluorescent light bulbs, thermometers) and for chemical processing (e.g., production of chlorine and alkali via mercury electrochemical cells) and many of these industrial sites are now polluted with mercury contaminated soil as a result of previous releases and/or inadvertent leaks. Remediation techniques for Hg contaminated soils are either based on thermal desorption and recovery of the mercury or excavation and shipping of large volumes of material to remote facilities for treatment and disposal. Both of these alternatives are extremely costly. The Brookhaven National Laboratory (BNL) Environmental Research & Technology Division (ERTD) has demonstrated, in laboratory-scale experiments, the viability of treating mercury contaminated soils by means of sulfide treatment rods inserted into the soil through a process known as In Situ Mercury Stabilization (ISMS). This approach is partly based on BNL's patented and successfully licensed ex situ process for Hg treatment, Sulfur Polymer Stabilization/Solidification (SPSS) which converts Hg to the more stable sulfide form. The original experiments showed that Hg homogeneously distributed in soil rapidly migrates to form a high concentration zone of chemically stable mercuric sulfide near the treatment rods while concentrations of Hg in surrounding areas away from the treatment rods are depleted to acceptable levels. BSA has subsequently filed for patent protection on the ISMS technology. If further developed it has the potential for large-scale in-situ treatment of contaminated soils that could substantially reduce the prohibitive cost of thermal desorption and/or excavation and disposal. Licensing and spin-off technology development opportunities would then be viable. Depending on performance and regulatory acceptance, the treated mercury could either be excavated for disposal elsewhere or left in place as a stable alternative. Excavated spent treatment rods could be processed by the SPSS process to reduce the potential for dispersion and lower leachability even further. The Phase I objectives of the In Situ Mercury Stabilization Treatment Process Technology Maturation Project were to: (1) replicate the original bench-scale results that formed the basis for BNL's patent application, i.e., mercury contamination in soil will migrate to and react with 'rods' containing sulfur and/or sulfur compounds, (2) provide enough information to evaluate a decision to conduct further development, and (3) establish some of the critical parameters that require further technology maturation during Phase II. The information contained in this report summarizes the work conducted in Phase I to meet these objectives.

  8. Stabilization of microorganisms for in situ degradation of toxic chemicals

    International Nuclear Information System (INIS)

    Methods for large-scale microencapsulation of bacteria and nutrients into microbeads with small enough diameters to travel through aquifers have been developed at the University of Idaho. Both free and immobilized cells of Flavobacterium ATCC 39723, a gram-negative aerobe that degrades various chlorinated phenols, into aquifer microcosms, through which pentachlorophenol (PCP)-contaminated groundwater flowed at in situ flow rates. Aquifer samples were collected with an auger from three wells at the University of Idaho Ground Water Research Site, and packed into 24 columns. Some sterile columns were also prepared, by irradiation at the Washington State University Radiation Center. In some of the columns the free Flavobacterium cells were mixed with the aquifer material before packing the columns. In others, agarose-microimmobilized Flavobacterium were mixed into the aquifer material. The effluent from each column was collected daily for 170 days and analyzed by UV spectroscopy or HPLC for remaining PCP. There were no statistically significant differences between the degradation rates of free or encapsulated Flavobacterium in sterile or native aquifer material as tested in these experiments. This work has shown at the lab scale that encapsulated PCP-degrading Flavobacterium were able to survive under conditions of starvation, predation, and lack of water

  9. Ligament balancing in total knee arthroplastyMedial stabilizing technique

    Directory of Open Access Journals (Sweden)

    Shuichi Matsuda

    2015-10-01

    Full Text Available Ligament balancing is one of the most important surgical techniques for successful total knee arthroplasty. It has traditionally been recommended that medial and lateral as well as flexion and extension gaps are equal. This article reviews the relevant literature and discusses the clinical importance of the aforementioned gaps. Current evidence indicates that achieving medial stability throughout the range of motion should be a high priority in ligament balancing in total knee arthroplasty. Finally, the medial stabilising surgical technique, which aims to achieve good medial stability in posterior cruciate-retaining total knee arthroplasty, is introduced.

  10. 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...

  11. TECHNIQUE FOR IN SITU CALIBRATION OF PARTICULATE MASS MONITORS

    Science.gov (United States)

    Two types of aerosol generators, the Riker Laboratories metered spray can and the Mistogen EN145 ultrasonic nebulizer, were evaluated by laboratory measurements for application to the in situ calibration of particulate mass monitors for stationary sources. The metered spray can d...

  12. 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

  13. Architectural stability analysis of the rotary-laser scanning technique

    Science.gov (United States)

    Xue, Bin; Yang, Xiaoxia; Zhu, Jigui

    2016-03-01

    The rotary-laser scanning technique is an important method in scale measurements due to its high accuracy and large measurement range. This paper first introduces a newly designed measurement station which is able to provide two-dimensional measurement information including the azimuth and elevation by using the rotary-laser scanning technique, then presents the architectural stability analysis of this technique by detailed theoretical derivations. Based on the designed station, a validation using both experiment and simulation is presented in order to verify the analytic conclusion. The results show that the architectural stability of the rotary-laser scanning technique is only affected by the two scanning angles' difference. And the difference which brings the best architectural stability can be calculated by using pre-calibrated parameters of the two laser planes. This research gives us an insight into the rotary-laser scanning technique. Moreover, the measurement accuracy of the rotary-laser scanning technique can be further improved based on the results of the study.

  14. Polyphosphate Remediation Technology for In-Situ Stabilization of Uranium

    International Nuclear Information System (INIS)

    A labortory testing program has been conducted to optimize polyphosphate remediation technology for implementation through a field-scale technology infiltration demonstration to stabilize soluble, uranium-bearing source phases in the vadose zone and capillary fringe. Source treatment in the deep vadose zone will accelerate the natural attenuation of uranium to more thermodynamically stable uranium-phosphate minerals, enhancing the performance of the proposed polyphosphate remediation within the 300 Area aquifer. The objective of this investigation was to develop polyphosphate remediation technology to treat uranium contamination contained within the deep vadose zone and capillary fringe. This paper presents the results of an investigation that evaluated the rate and extent of reaction between polyphosphate and the uranium mineral phases present within the 300 Area vadose zone and capillary fringe and autunite formation as a function of polyphosphate formulation and concentration. This information is critical for identifying the optimum implementation approach and controlling the flux of uranium from the vadose zone and capillary fringe to the underlying aquifer during remediation. Results from this investigation will be used to design a full-scale remediation of uranium at the 300 Area of the Hanford Site.

  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. 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 Tis 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

  17. In-situ containment and stabilization of buried waste: Annual report FY 1994

    International Nuclear Information System (INIS)

    The two landfills of specific interest are the Chemical Waste Landfill (CWL) and the Mixed Waste Landfill (MWL), both located at Sandia National Laboratory. The work is comprised of two subtasks: (1) In-Situ Barriers and (2) In-Situ Stabilization of Contaminated Soils. The main environmental concern at the CWL is a chromium plume resulting from disposal of chromic acid and chromic sulfuric acid into unlined pits. This program has investigated means of in-situ stabilization of chromium contaminated soils and placement of containment barriers around the CWL. The MWL contains a plume of tritiated water. In-situ immobilization of tritiated water with cementitious grouts was not considered to be a method with a high probability of success and was not pursued. This is discussed further in Section 5.0. Containment barriers for the tritium plume were investigated. FY 94 work focused on stabilization of chromium contaminated soil with blast furnace slag modified grouts to bypass the stage of pre-reduction of Cr(6), barriers for tritiated water containment at the MWL, continued study of barriers for the CWL, and jet grouting field trials for CWL barriers at an uncontaminated site at SNL. Cores from the FY 93 permeation grouting field trails were also tested in FY 94

  18. Single Molecule Techniques for Advanced in situ Hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Hollars, C W; Stubbs, L; Carlson, K; Lu, X; Wehri, E

    2003-02-03

    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.

  19. 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

  20. 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.

  1. 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.

  2. Theoretical stability assessment of uranyl phosphates and apatites: Selection of amendments for in situ remediation of uranium

    Energy Technology Data Exchange (ETDEWEB)

    Raicevic, S. [Institute of Nuclear Sciences VINCA, Radiation and Environmental Protection Laboratory, P.O.Box 522, 11001 Belgrade (Serbia and Montenegro)]. E-mail: raich@beotel.yu; Wright, J.V. [PIMS NW, Inc., 201 North Edison, Suite 226, Richland, WA 99336 (United States); Veljkovic, V. [Institute of Nuclear Sciences VINCA, Center for Multidisciplinary Research and Engineering, P.O.Box 522, 11001 Belgrade (Serbia and Montenegro); Conca, J.L. [Los Alamos National Laboratory, 115 North Main Street, Carlsbad, NM 88220 (United States)

    2006-02-15

    Addition of an amendment or reagent to soil/sediment is a technique that can decrease mobility and reduce bioavailability of uranium (U) and other heavy metals in the contaminated site. According to data from literature and results obtained in field studies, the general mineral class of apatites was selected as a most promising amendment for in situ immobilization/remediation of U. In this work we presented theoretical assessment of stability of U(VI) in four apatite systems (hydroxyapatite (HAP), North Carolina Apatite (NCA), Lisina Apatite (LA), and Apatite II) in order to determine an optimal apatite soil amendment which could be used for in situ remediation of uranium. In this analysis we used a theoretical criterion which is based on calculation of the ion-ion interaction potential, representing the main term of the cohesive energy of the matrix/pollutant system. The presented results of this analysis indicate (i) that the mechanism of immobilization of U by natural apatites depends on their chemical composition and (ii) that all analyzed apatites represent, from the point of view of stability, promising materials which could be used in field remediation of U-contaminated sites.

  3. Responsive Aqueous Foams Stabilized by Silica Nanoparticles Hydrophobized in Situ with a Conventional Surfactant.

    Science.gov (United States)

    Zhu, Yue; Pei, Xiaomei; Jiang, Jianzhong; Cui, Zhenggang; Binks, Bernard P

    2015-12-01

    In the recent past, switchable surfactants and switchable/stimulus-responsive surface-active particles have been of great interest. Both can be transformed between surface-active and surface-inactive states via several triggers, making them recoverable and reusable afterward. However, the synthesis of these materials is complicated. In this paper we report a facile protocol to obtain responsive surface-active nanoparticles and their use in preparing responsive particle-stabilized foams. Hydrophilic silica nanoparticles are initially hydrophobized in situ with a trace amount of a conventional cationic surfactant in water, rendering them surface-active such that they stabilize aqueous foams. The latter can then be destabilized by adding equal moles of an anionic surfactant, and restabilized by adding another trace amount of the cationic surfactant followed by shaking. The stabilization-destabilization of the foams can be cycled many times at room temperature. The trigger is the stronger electrostatic interaction between the oppositely charged surfactants than that between the cationic surfactant and the negatively charged particles. The added anionic surfactant tends to form ion pairs with the cationic surfactant, leading to desorption of the latter from particle surfaces and dehydrophobization of the particles. Upon addition of another trace amount of cationic surfactant, the particles are rehydrophobized in situ and can then stabilize foams again. This principle makes it possible to obtain responsive surface-active particles using commercially available inorganic nanoparticles and conventional surfactants. PMID:26542227

  4. 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...

  5. In Situ Mechanical Testing Techniques for Real-Time Materials Deformation Characterization

    Science.gov (United States)

    Rudolf, Chris; Boesl, Benjamin; Agarwal, Arvind

    2016-01-01

    In situ mechanical property testing has the ability to enhance quantitative characterization of materials by revealing the occurring deformation behavior in real time. This article will summarize select recent testing performed inside a scanning electron microscope on various materials including metals, ceramics, composites, coatings, and 3-Dimensional graphene foam. Tensile and indentation testing methods are outlined with case studies and preliminary data. The benefits of performing a novel double-torsion testing technique in situ are also proposed.

  6. Rapid in situ X-ray position stabilization via extremum seeking feedback.

    Science.gov (United States)

    Zohar, S; Venugopalan, N; Kissick, D; Becker, M; Xu, S; Makarov, O; Stepanov, S; Ogata, C; Sanishvili, R; Fischetti, R F

    2016-03-01

    X-ray beam stability is crucial for acquiring high-quality data at synchrotron beamline facilities. When the X-ray beam and defining apertures are of similar dimensions, small misalignments driven by position instabilities give rise to large intensity fluctuations. This problem is solved using extremum seeking feedback control (ESFC) for in situ vertical beam position stabilization. In this setup, the intensity spatial gradient required for ESFC is determined by phase comparison of intensity oscillations downstream from the sample with pre-existing vertical beam oscillations. This approach compensates for vertical position drift from all sources with position recovery times <6?s and intensity stability through a 5?m aperture measured at 1.5% FWHM over a period of 8?hours. PMID:26917131

  7. 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 m) 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, Gebrder 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 n309517.

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

    International Nuclear Information System (INIS)

    The two-dimensional slope error of an X-ray mirror has been retrieved by employing the speckle scanning technique, which will be valuable at synchrotron radiation facilities and in astronomical telescopes. 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

  9. Using geophysical techniques to control in situ thermal remediation

    International Nuclear Information System (INIS)

    Monitoring the thermal and hydrologic processes that occur during thermal environmental remediation programs in near real-time provides essential information for controlling the process. Geophysical techniques played a crucial role in process control as well as for characterization during the recent Dynamic Underground Stripping Project demonstration in which several thousand gallons of gasoline were removed from heterogeneous soils both above and below the water table. Dynamic Underground Stripping combines steam injection and electrical heating for thermal enhancement with ground water pumping and vacuum extraction for contaminant removal. These processes produce rapid changes in the subsurface properties including changes in temperature fluid saturation, pressure and chemistry. Subsurface imaging methods are used to map the heated zones and control the thermal process. Temperature measurements made in wells throughout the field reveal details of the complex heating phenomena. Electrical resistance tomography (ERT) provides near real-time detailed images of the heated zones between boreholes both during electrical heating and steam injection. Borehole induction logs show close correlation with lithostratigraphy and, by identifying the more permeable gravel zones, can be used to predict steam movement. They are also useful in understanding the physical changes in the field and in interpreting the ERT images. Tiltmeters provide additional information regarding the shape of the steamed zones in plan view. They were used to track the growth of the steam front from individual injectors

  10. Long-term stabilization of foams and emulsions with in-situ formed microparticles from hydrophobic cellulose.

    Science.gov (United States)

    Wege, Hartmut A; Kim, Sejong; Paunov, Vesselin N; Zhong, Qixin; Velev, Orlin D

    2008-09-01

    We report a simple method to produce foams and emulsions of extraordinary stability by using hydrophobic cellulose microparticles, which are formed in situ by a liquid-liquid dispersion technique. The hydrophobic cellulose derivative, hypromellose phthalate (HP), was initially dissolved in water-miscible solvents such as acetone and ethanol/water mixtures. As these HP stock solutions were sheared in aqueous media, micron sized cellulose particles formed by the solvent attrition. We also designed and investigated an effective and simple process for making HP particles without any organic solvents, where both the solvent and antisolvent were aqueous buffer solutions at different pH. Consequently, the HP particles adsorbed onto the water/air or water/oil interfaces created during shear blending, resulting in highly stable foams or foam/emulsions. The formation of HP particles and their ability for short-term and long-term stabilization of interfaces strongly depended on the HP concentration in stock solutions, as well as the solvent chemistry of both stock solutions and continuous phase media. Some foams and emulsion samples formed in the presence of ca. 1 wt% HP were stable for months. This new class of nontoxic inexpensive cellulose-based particle stabilizers has the potential to substitute conventional synthetic surfactants, especially in edible, pharmaceutical and biodegradable products. PMID:18646883

  11. In situ saphenous vein arterial bypass for infrainguinal revascularization: initial experience using an open technique.

    Science.gov (United States)

    de Mello, A V; Santos, C M; Silva, J L; Souza, M T; Portilho, M A; Guimares, A V; Freitas, R G; Silvrio, J W

    1991-01-01

    The authors describe their initial experience with the use of the in situ saphenous vein arterial by-pass technique for infrainguinal revascularization. From December 1986 to August 1989, we performed 101 in situ saphenous vein arterial by-passes. From these 101 by-pass, 18 composite or partial in situ vein by-passes (in situ + reversed vein) and 2 extra-anatomical sequencial by-passes (one axillofemoral and one cross-over femorofemoral proximal by-passes extended by in situ saphenous vein femoropopliteal arterial by-passes) were withdrawn from the statistics, with the purpose of analysing the natural evolution of the in situ vein arterial by-pass without the insertion of reversed vein segments and/or the influence of artificial grafts to improve arterial inflow. Therefore only 81 in situ by-pass cases will be analysed in the present paper. From these 81 cases, 44 (54.3%) were performed in diabetic patients and limb salvage was the indication for by-pass in 63 (81%). The saphenous vein valves were rendered incompetent utilising the retrograde Mills-Leather valvulotome and exposing the greater saphenous vein with a continuous incision. In the 81 cases, wound complications occurred in 18 limbs (22%) and operative mortality (30 days) was 6.1%. Primary cumulative patency rate of the 81 cases was 77% and secondary cumulative patency rate was 80%, at the end of the analysed period. The open technique, using a retrograde valvulotome and exposing the entire conduit of the greater saphenous vein, became our preferred technique for infrainguinal revascularization. PMID:1765713

  12. 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.

  13. 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

  14. 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

  15. A novel in-situ sampling and VFA sensor technique for anaerobic systems

    DEFF Research Database (Denmark)

    Pind, Peter Frode; Angelidaki, Irini; Ahring, Birgitte Kir

    2002-01-01

    that has made it possible to monitor VFA on-line in one of the most difficult media: animal slurry or manure. A novel in-situ filtration technique has made it possible to perform microfiltration inside the reactor system. This filter enables sampling from closed reactor systems without large scale...

  16. Intercomparison of four different in-situ techniques for ambient formaldehyde measurements in urban air

    OpenAIRE

    C. Hak; Pundt, I.; Trick, S.; C Kern; Platt, U.; Dommen, J; Ordez, C.; Prvt, A. S. H.; Junkermann, W.; Astorga-Llorns, C.; Larsen, B. R.; Mellqvist, J; Strandberg, A.; Yu, Y.; Galle, B

    2005-01-01

    Results from an intercomparison of several currently used in-situ techniques for the measurement of atmospheric formaldehyde (CH2O) are presented. The measurements were carried out at Bresso, an urban site in the periphery of Milan (Italy) as part of the FORMAT-I field campaign. Eight instruments were employed by six independent research groups using four different techniques: Differential Optical Absorption Spectroscopy (DOAS), Fourier Transform Infra Red (FTIR) interf...

  17. 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)

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

    KAUST Repository

    Satyawali, Yamini

    2010-09-01

    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 (200mgL-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. © 2010 Elsevier B.V.

  19. 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

  20. 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

  1. 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.

  2. Lithographically fabricated silicon microreactor for in situ characterization of heterogeneous catalystsEnabling 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.

  3. Lithographically fabricated silicon microreactor for in situ characterization of heterogeneous catalystsEnabling correlative characterization techniques

    Science.gov (United States)

    Baier, S.; Rochet, A.; Hofmann, G.; Kraut, M.; Grunwaldt, J.-D.

    2015-06-01

    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.

  4. 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.

  5. Lithographically fabricated silicon microreactor for in situ characterization of heterogeneous catalystsEnabling 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

  6. In situ characterization of interfacial and bulk properties of lithium polymer batteries using 4-probe DC techniques

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Meilin [Georgia Inst. of Tech., Atlanta, GA (United States). School of Materials Science and Engineering; Visco, S.J.; De Jonghe, L.C. [Lawrence Berkeley Lab., CA (United States)

    1992-11-01

    The use of transient and steady-state 4-probe techniques for the evaluation of the limitations to performance in solid-state electrochemical devices is described. The application of sequential, bipolar square-wave current pulses to a solid polymer cell with two internal reference electrodes allows separation of the polarization behavior of the various components of the cell, and indicates the rate limiting processes in the cell. Careful design of the experimental cell and appropriate selection of current pulse width allows evaluation of fundamental kinetic and transport properties, as well as activation parameters. Steady state constant-current measurements using 4-probe cells allows in situ observation of interface stability and/or polarization as a function of time as the cell is cycling.

  7. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Spence, R. D. [Oak Ridge National Lab., TN (United States); Kauschinger, J. L. [Ground Environmental Services, Inc., Alpharetta, GA (United States)

    1997-05-01

    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. T his 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.

  9. 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 Americas 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. lindeniis 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.

  10. Stability of silver nanoparticle monolayers determined by in situ streaming potential measurements

    International Nuclear Information System (INIS)

    A silver particle suspension obtained by a chemical reduction was used in this work. Monolayers of these particles (average size 28 nm) on mica modified by poly(allylamine hydrochloride) were produced under diffusion-controlled transport. Monolayer coverages, quantitatively determined by atomic force microscopy (AFM) and SEM, was regulated by adjusting the nanoparticle deposition time and the suspension concentration. The zeta potential of the monolayers was determined by streaming potential measurements carried out under in situ (wet) conditions. These measurements performed for various ionic strengths and pH were interpreted in terms of the three-dimensional (3D) electrokinetic model. The stability of silver monolayers was also investigated using streaming potential and the AFM methods. The decrease in the surface coverage of particles as a function of time and ionic strength varied between 10?1 and 10?4M was investigated. This allowed one to determine the equilibrium adsorption constant Ka and the binding energy of silver particles (energy minima depth). Energy minima depth were calculated that varied between ?18kT for I=10?1M and ?19kT for I=10?4 for pH 5.5 and T=298K. Our investigations suggest that the interactions between surface and nanoparticles are controlled by the electrostatic interactions among ion pairs. It was also shown that the in situ electrokinetic measurements are in accordance with those obtained by more tedious ex situ AFM measurements. This confirmed the utility of the streaming potential method for direct kinetic studies of nanoparticle deposition/release processes.Graphical Abstract

  11. 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)

  12. 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.

  13. Shape-and size-controlled Ag nanoparticles stabilized by in situ generated secondary amines

    International Nuclear Information System (INIS)

    Highlights: • Ag nanoparticles were generated from Ag amido complexes AgNiPr2 and AgN(SiMe3)2. • Ag nanoparticles were stabilized by in situ generated HNiPr2 or HN(SiMe3)2. • 1 or 5 equiv. of ethylenediamine as additional capping agent decreases the average size of the particles. • Ethylenediamine favor the formation of spherical particles. - Abstract: Silver amides such as AgNiPr2 and AgN(SiMe3)2 have been employed successfully as precursors for the yield synthesis of silver nanoparticles under mild conditions of dihydrogen gas reduction (2 atm) in organic media. Transmission electron microscopy (TEM) showed the formation of silver nanoparticles with FCC structure, variously sized from 26 to 35 nm for AgNiPr2 and from 14 to 86 nm for AgN(SiMe3)2, the synthesis could take place in absence of added stabilizers due to the in situ formation of secondary amines from the reaction of dihydrogen gas with the amide ligands of the silver precursor. Indeed, the presence of HNR2 (R = iPr2, N(SiMe3)2) on the surface of the nanoparticle was confirmed by spectroscopic means. Finally, the addition of ethylenediamine as additional capping agent allowed not only the control of the structural characteristics of the resulting Ag nanoparticles (well-dispersed with spherical shape), but that regarding the nanoparticle size as it inhibited overgrowth, limiting it to ca. 25 nm

  14. Shape-and size-controlled Ag nanoparticles stabilized by in situ generated secondary amines

    Energy Technology Data Exchange (ETDEWEB)

    Ramírez-Meneses, E., E-mail: esther.ramirez@ibero.mx [Departamento de Ingeniería y Ciencias Químicas, Universidad Iberoamericana, Prolongación Paseo de la Reforma 880, Lomas de Santa Fe, Distrito Federal C.P. 01219 (Mexico); Montiel-Palma, V. [Centro de Investigaciones Químicas, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001 Col. Chamilpa, Cuernavaca, Morelos C.P. 62209 (Mexico); Domínguez-Crespo, M.A.; Izaguirre-López, M.G. [Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada-IPN, Unidad Altamira. Km 14.5 Carretera Tampico-Puerto Industrial, 89600 Altamira, Tamaulipas (Mexico); Palacios-Gonzalez, E. [Laboratorio de Microscopia de Ultra alta Resolución, Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas No. 152, C.P. 07730 México D.F. (Mexico); Dorantes-Rosales, H. [Departamento de Metalurgia, E.S.I.Q.I.E.-I.P.N., Unidad Profesional Adolfo López Mateos, Zacatenco, Delegación. Gustavo A. Madero, C.P. 07738 México D.F. (Mexico)

    2015-09-15

    Highlights: • Ag nanoparticles were generated from Ag amido complexes AgN{sup i}Pr{sub 2} and AgN(SiMe{sub 3}){sub 2}. • Ag nanoparticles were stabilized by in situ generated HN{sup i}Pr{sub 2} or HN(SiMe{sub 3}){sub 2}. • 1 or 5 equiv. of ethylenediamine as additional capping agent decreases the average size of the particles. • Ethylenediamine favor the formation of spherical particles. - Abstract: Silver amides such as AgN{sup i}Pr{sub 2} and AgN(SiMe{sub 3}){sub 2} have been employed successfully as precursors for the yield synthesis of silver nanoparticles under mild conditions of dihydrogen gas reduction (2 atm) in organic media. Transmission electron microscopy (TEM) showed the formation of silver nanoparticles with FCC structure, variously sized from 26 to 35 nm for AgN{sup i}Pr{sub 2} and from 14 to 86 nm for AgN(SiMe{sub 3}){sub 2}, the synthesis could take place in absence of added stabilizers due to the in situ formation of secondary amines from the reaction of dihydrogen gas with the amide ligands of the silver precursor. Indeed, the presence of HNR{sub 2} (R = iPr{sub 2}, N(SiMe{sub 3}){sub 2}) on the surface of the nanoparticle was confirmed by spectroscopic means. Finally, the addition of ethylenediamine as additional capping agent allowed not only the control of the structural characteristics of the resulting Ag nanoparticles (well-dispersed with spherical shape), but that regarding the nanoparticle size as it inhibited overgrowth, limiting it to ca. 25 nm.

  15. Nuclear in-situ analysis techniques for the mineral and energy resources mining industries

    Energy Technology Data Exchange (ETDEWEB)

    Borsaru, M.; Charbucinski, J.; Eisler, P.L. [Commonwealth and Industrial Research Organisation, Victoria (Australia)

    1994-12-31

    The technology for in-situ analysis based on nuclear techniques, ie for borehole logging and surface analysis, is now utilised by the energy and metalliferous mining industry. The techniques developed by CSIRO are spectrometric. This uniquely provides opportunity for implementing analysis techniques which are direct instead of being based on the measurement of surrogates. Thus, the techniques lead to quantitative assays, which are available on-line, which provides mining-technology users with increased flexibility in scheduling operations to achieve improved productivity. The paper reviews in detail the performance of the various CSIRO techniques (and the consequent licensed SIROLOG technology) in current routine applications, ie in deposits of black and brown coals and iron ore. It also briefly discusses the potential for logging applications in the nickel, manganese, copper and lead-zinc mining industries. The paper discusses new relevant developments, namely the ultra-low activity probes and face analysers.

  16. Nuclear in-situ analysis techniques for the mineral and energy resources mining industries

    International Nuclear Information System (INIS)

    The technology for in-situ analysis based on nuclear techniques, such as borehole logging and surface analysis, is now utilised by the energy and metalliferous mining industry. The techniques developed by CSIRO are spectrometric. This uniquely provides opportunity for implementing analysis techniques which are direct instead of being based on the measurement of surrogates. Thus, the techniques lead to quantitative assays, which are available on-line, which provides mining-technology users with increased flexibility in scheduling operations to achieve improved productivity. The paper reviews in detail the performance of the various CSIRO techniques (and the consequent licensed SIROLOG technology) in current routine application such as deposits of black and brown coals and iron ore. It also briefly discussed the potential for logging applications in the nickel, manganese, copper and lead-zinc mining industries. New relevant developments, namely the ultra-low activity probes and face analysers, are also presented. 14 refs., 1 tab., 5 figs

  17. 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.

  18. 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)

  19. 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 RIS-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.

  20. Powder metallurgical nanostructured medium carbon bainitic steel: Kinetics, structure, and in situ thermal stability studies

    Energy Technology Data Exchange (ETDEWEB)

    Lonardelli, I., E-mail: il244@cam.ac.uk [University of Cambridge, Materials Science and Metallurgy, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); University of Trento, Materials Engineering and Industrial Technologies, via Mesiano 77, 38123 Trento (Italy); Bortolotti, M. [Fondazione Bruno Kessler, via Sommarive 18, 38123 Trento (Italy); Beek, W. van [Swiss-Norwegian Beamlines, ESRF, BP 220, 38043 Grenoble Cedex (France); Girardini, L.; Zadra, M. [K4-Sint, via Dante 300, 38057 Pergine Valsugana (Italy); Bhadeshia, H.K.D.H. [University of Cambridge, Materials Science and Metallurgy, Pembroke Street, Cambridge CB2 3QZ (United Kingdom)

    2012-10-15

    It has been possible to produce incredibly fine plates of bainitic ferrite separated by a percolating network of retained austenite in a medium carbon steel produced by mechanical alloying followed by spark plasma sintering and isothermal heat treatment. This is because the sintering process limits the growth of the austenite grains to such an extent that the martensite-start temperature is suppressed in spite of the medium carbon concentration. Furthermore, the fine austenite grain size accelerates the bainite transformation, which can therefore be suppressed to low temperatures to obtain a nanostructure. Microscopy and in situ synchrotron X-ray diffraction were used to investigate the morphology and the thermal stability of the retained austenite during continuous heating. These latter experiments revealed a gradient of carbon concentration in the retained austenite and a reduced thermal stability in high carbon film-austenite. It was also possible to correlate the evolution of defect density and carbon depletion in both retained austenite and bainitic ferrite during tempering.

  1. 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.

  2. Powder metallurgical nanostructured medium carbon bainitic steel: Kinetics, structure, and in situ thermal stability studies

    International Nuclear Information System (INIS)

    It has been possible to produce incredibly fine plates of bainitic ferrite separated by a percolating network of retained austenite in a medium carbon steel produced by mechanical alloying followed by spark plasma sintering and isothermal heat treatment. This is because the sintering process limits the growth of the austenite grains to such an extent that the martensite-start temperature is suppressed in spite of the medium carbon concentration. Furthermore, the fine austenite grain size accelerates the bainite transformation, which can therefore be suppressed to low temperatures to obtain a nanostructure. Microscopy and in situ synchrotron X-ray diffraction were used to investigate the morphology and the thermal stability of the retained austenite during continuous heating. These latter experiments revealed a gradient of carbon concentration in the retained austenite and a reduced thermal stability in high carbon film-austenite. It was also possible to correlate the evolution of defect density and carbon depletion in both retained austenite and bainitic ferrite during tempering.

  3. 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; Hsel, Markus; Dam, Henrik Friis; Jrgensen, Mikkel; Gevorgyan, Suren; Kudret, Suleyman; Maes, Wouter; Lutsen, Laurence; Vanderzande, Dirk; Wrfel, Uli; Andriessen, Ronn; Rsch, Roland; Hoppe, Harald; Rivaton, Agns; Uzunoglu, Glsah 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 RIS-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...

  4. 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...

  5. 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:...

  6. 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)

  7. A new technique for in situ measurements of erosion and redeposition in a single discharge

    International Nuclear Information System (INIS)

    Based on the very different refractive constants of quartz substrates (? 1.5) and of amorphous deposits (>1.7) collected in the scrape-off layer of TEXTOR, in situ reflectometry has been developed in order to determine the growth rates. Laboratory experiments comparing the light intensities reflected from the rear side of the system glass/deposit to the theoretically calculated reflectivity demonstrate the feasibility of the technique. The optical constants needed are determined ex situ by ellipsometry. For the application to TEXTOR, the Stockholm TEXTOR collector probe system has been equipped with fibre optic light guides which end behind quartz substrates carried by a replaceable graphite head. This arrangement avoids disturbance due to vibration or due to observations over long distances. (orig.)

  8. 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.

  9. 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

  10. Deciphering the thermal behavior of lithium rich cathode material by in situ X-ray diffraction technique

    Science.gov (United States)

    Muhammad, Shoaib; Lee, Sangwoo; Kim, Hyunchul; Yoon, Jeongbae; Jang, Donghyuk; Yoon, Jaegu; Park, Jin-Hwan; Yoon, Won-Sub

    2015-07-01

    Thermal stability is one of the critical requirements for commercial operation of high energy lithium-ion batteries. In this study, we use in situ X-ray diffraction technique to elucidate the thermal degradation mechanism of 0.5Li2MnO3-0.5LiNi0.33Co0.33Mn0.33O2 lithium rich cathode material in the absence and presence of electrolyte to simulate the real life battery conditions and compare its thermal behavior with the commercial LiNi0.33Co0.33Mn0.33O2 cathode material. We show that the thermal induced phase transformations in delithiated lithium rich cathode material are much more intense compared to similar single phase layered cathode material in the presence of electrolyte. The structural changes in both cathode materials with the temperature rise follow different trends in the absence and presence of electrolyte between 25 and 600 C. Phase transitions are comparatively simple in the absence of electrolyte, the fully charged lithium rich cathode material demonstrates better thermal stability by maintaining its phase till 379 C, and afterwards spinel structure is formed. In the presence of electrolyte, however, the spinel structure appears at 207 C, subsequently it transforms to rock salt type cubic phase at 425 C with additional metallic, metal fluoride, and metal carbonate phases.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  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. 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...

  17. 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

  18. Practical applications of in-situ plasma-etching diagnostic techniques

    International Nuclear Information System (INIS)

    Mass spectrometry, ellipsometry and optical emission spectroscopy are used as in-situ plasma diagnostic techniques in three separate studies of plasma etching: Investigations of the conditions which cause, and the mechanism of, the roughening of Si(100) when using Cl2 plasmas; studies of triode-mode etching of Si(100) and SiO2 using both Cl2 and SF6 plasmas; experimental and theoretical studies of the distribution of chemical species in SF6/O2 plasmas over Si(100) and SiO2. (orig.)

  19. Effect of C16TMA contents on the thermal stability of organo-bentonites: In situ X-ray diffraction analysis

    International Nuclear Information System (INIS)

    Highlights: ? Organo-bentonites were prepared at C16TMABr/CEC ratios up to 11. ? Disorder configuration of C16TMA cations was observed at higher C16TMABr/CEC ratios. ? The evolved gases during the calcinations of organoclays were analyzed by MS-TG. ? In situ XRD technique detected clearly the phase disorder in the range 50150 C. ? Collapse of organoclays depended on the temperature and the used atmospheres. - Abstract: Different concentrations of cetyl trimethylammonium bromide solutions were cation exchanged with bentonite clay mineral, at room temperature. The resulting organoclays were characterized by elemental analysis C and N, X-ray diffraction and thermal gravimetric analysis. The evolved gases during the calcination of organoclays were identified by online mass spectrometry coupled with thermal gravimetry technique. Meanwhile, in situ X-ray diffraction was used to have insight on the thermal stability of the organoclays in air atmosphere. X-ray diffraction at room temperature indicated that a disorder transition phase from bilayer to paraffin configuration occurred at higher surfactant-cation exchange capacity ratios, with two phases at 3.25 and 2.00 nm, respectively. The in situ X-ray diffraction confirmed the presence of these two phases with improved reflections intensities in the range of 100200 C. Above this temperature, both phases collapsed due to the decomposition of the surfactants as recorded by mass spectrometry thermal gravimetric analysis.

  20. 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.

  1. 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

  2. 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 3years. 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 188days after tagging. Of these, 90% were located at the site of capture, while the remaining individuals were resighted between 200m and 1.1km from initial site of capture over 29days later. In situ growth rates ranged between 0.1 and 0.6mm/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., 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

  3. 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

  4. In-situ magnetic gauging technique used at LANL-method and shock information obtained

    Science.gov (United States)

    Sheffield, S. A.; Gustavsen, R. L.; Alcon, R. R.

    2000-04-01

    Measuring techniques, including magnetic gauges, quartz gauges, manganin gauges, PVDF gauges, velocity interferometry, piezoelectric pins, shorting pins, flash gaps, etc., have been used over the years in shock experiments in condensed phase materials. The use of a particular technique depends on the measured parameter and the sample material properties. This paper concentrates on in-situ magnetic gauging which is particularly useful in high explosive (HE) shock initiation experiments. A short history of this technique will be given but the main discussion will concentrate on the multiple magnetic gauge technique developed at Los Alamos National Lab. (LANL). Vorthman and Wackerle started the technique development in 1980, concentrating on particle velocity and "impulse" gauges so that Lagrange analysis could be used to map the entire reactive field. Over the years, changes to the gauge design, fabrication, and experimental focus have led to the present LANL technique. During the past two years measurements have tracked the reactive wave evolution resulting from a shock-to-detonation transition in several high explosive materials. Analysis of the data from a single experiment provides: 1) an unreacted Hugoniot point in which both the shock velocity and particle velocity are measured, 2) shock front tracking, 3) ten particle velocity profiles which measure the reactive wave evolution, 4) a "Pop-plot" distance-(time-)to-detonation point, and 5) a 3% measurement of the detonation velocity. Details of the experimental setup and information from several experiments will be discussed.

  5. 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.

  6. 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.

  7. 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

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

    International Nuclear Information System (INIS)

    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

  9. 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.

  10. New application technology for 'in situ' pipeline protection using pigging techniques

    Energy Technology Data Exchange (ETDEWEB)

    Pretorius, Louis Charles [Corrocoat SA (PTY) Ltd., Durban (South Africa)

    2005-07-01

    Pigging of long pipelines is a technique for in situ (field) coating, creating seamless internal structural linings. Originally developed for cleaning pipes, the system was adapted to apply internal anti-corrosion protection to pipes using a thin epoxy layer, which had some problems in weld coverage, stress cracking, poor cold weather curing and the inability to fill pitting corrosion metal loss. New coating materials, revised application methods and modified pigging equipment have made it possible to apply in situ liquid film coatings up to 1 mm thick, as an internal corrosion barrier to pipes, in a single application (similar to continuous screeding) resulting in a bonded 'GRP pipe within a steel pipe'. The method can be used for new projects on fully welded pipe lines avoiding coating problems associated with flange joints and/or couplings, or for refurbishment of old pipelines, varying from 150-900 mm diameter, up to 12 km long. Pipes can be buried, submerged, continuously welded or flanged. Many different pipes, such as oil platform to shore based pipelines, can all be treated using this method. Thick film polymer pigging techniques create new possibilities for Engineers to extend the life of pipeline systems, with significant cost savings compared to replacement pipe. (author)

  11. 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.

  12. 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)

  13. Comparison of Different Techniques For Tuning of Power System Stabilizer

    OpenAIRE

    BAYAT, Ehsan; DELAVAR?, Hadi

    2015-01-01

    Abstract. The power system is subjected to different types of disturbances such as small changes in the load that affects its efficiency and sometimes leads to unstable system. These disturbances cause oscillations at low frequencies that are undesirable since it affects the amount of transferred power through the transmission lines and leads to external stress to the mechanical shaft. In order to compress low-frequency oscillations, a common solution is use the power system stabilizer (PSS)....

  14. 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

  15. 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.

  16. 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.

  17. Dimensional stability of a novel polyvinyl siloxane impression technique

    Scientific Electronic Library Online (English)

    Moira Pedroso, Leo; Camila Paloma, Pinto; Ana Paula, Sponchiado; Brbara 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

  18. POSSIBILITIES OF USING THE FLUORESCENCE IN SITU HYBRIDIZATION TECHNIQUE IN THE DIAGNOSIS OF BLADDER CANCER AND ITS RECURRENCES

    Directory of Open Access Journals (Sweden)

    V. B. Matveev

    2014-07-01

    Full Text Available Fluorescence in situ hybridization is a current technique to detect chromosomal specific genetic disorders specific to urinary bladder cancer (UBC. This technique may be used to diagnose UBC, to follow up patients after surgical treatment, to evaluate the efficiency of adjuvant therapy in these patients, and to predict the development of disease recurrence.

  19. 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)

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

    OpenAIRE

    Alch Ramrez, Juan de Dios; Castro Lpez, Antonio Jess; Rodrigo Castro, Mara 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...

  1. 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.

  2. In-Situ Magnetic Gauging Technique Used at LANL -- Method and Shock Information Obtained

    Science.gov (United States)

    Sheffield, Stephen A.

    1999-06-01

    Measuring techniques, including magnetic gauges, quartz gauges, manganin gauges, PVDF gauges, velocity interferometry (VISAR, Fabry-Perot, ORVIS, etc.), piezoelectric pins, shorting pins, flash gaps, etc., have been used over the years to measure shock properties and wave evolution in condensed phase materials. In general, each of these techniques has its own strengths and weaknesses. The use of a particular technique depends on the measured parameter and the sample material properties. This paper will concentrate on in-situ magnetic gauging which is particularly useful in high explosive shock initiation experiments. A short history of this technique will be given but the main discussion will concentrate on the multiple magnetic gauge technique developed at Los Alamos National Lab.(LANL). Vorthman and Wackerle (Vorthman, J.E., ``Facilities for the Study of Shock Induced Decomposition in High Explosive,'' in Shock Waves in Condensed Matter -- 1981, Eds. W. J. Nellis, L. Seaman, and R.A. Graham, AIP Conference Proceedings No. 78 (1982) p. 680.) started developing the technique in 1980, concentrating on particle velocity and ``impulse'' gauges so that Lagrange analysis could be used to map the entire reactive field. Over the years, changes to the gauge design, fabrication, and experimental focus have led to the present LANL capability. During the past two years measurements have tracked the reactive wave evolution resulting from a shock-to-detonation transition in several high explosive materials. The data from a single experiment provides: 1)particle velocity wave profiles from ten to twelve depths in the sample, 2) shock front tracking, 3) an unreacted Hugoniot point (in which both the shock velocity and particle velocity are measured), 4) a ``Pop-plot'' or distance-(time-)to-detonation point, and 5) a 3% measurement of the detonation velocity. Details of the experimental setup and information from several experiments will be discussed.

  3. 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)

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

    International Nuclear Information System (INIS)

    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: ? We combined ChlaF measurements with EM images to analyses the biocides action on stone biodeterioration agents. ? At lower biocide concentrations damage to photobiont and mycobiont cells integrity, ultrastructure and vitality were observed. ? The limited action of biocides on fungi and algae were detected using SEM-BSE. ? The combination of physiological and microscopy techniques improves the assessment of biocide action in situ. ? This new approach will help to optimize protocols of biocide application on stone.

  5. 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

  6. Intercomparison of four different in-situ techniques for ambient formaldehyde measurements in urban air

    Directory of Open Access Journals (Sweden)

    C. Hak

    2005-01-01

    Full Text Available Results from an intercomparison of several currently used in-situ techniques for the measurement of atmospheric formaldehyde (CH2O are presented. The measurements were carried out at Bresso, an urban site in the periphery of Milan (Italy as part of the FORMAT-I field campaign. Eight instruments were employed by six independent research groups using four different techniques: Differential Optical Absorption Spectroscopy (DOAS, Fourier Transform Infra Red (FTIR interferometry, the fluorimetric Hantzsch reaction technique (five instruments and a chromatographic technique employing C18-DNPH-cartridges (2,4-dinitrophenylhydrazine. White type multi-reflection systems were employed for the optical techniques in order to avoid spatial CH2O gradients and ensure the sampling of nearly the same air mass by all instruments. Between 23 and 31 July 2002, up to 13 ppbv of CH2O were observed. The concentrations lay well above the detection limits of all instruments. The formaldehyde concentrations determined with DOAS, FTIR and the Hantzsch instruments were found to agree within 11%, with the exception of one Hantzsch instrument, which gave systematically higher values. The two hour integrated samples by DNPH yielded up to 25% lower concentrations than the data of the continuously measuring instruments averaged over the same time period. The consistency between the DOAS and the Hantzsch method was better than during previous intercomparisons in ambient air with slopes of the regression line not significantly differing from one. The differences between the individual Hantzsch instruments could be attributed in part to the calibration standards used. Possible systematic errors of the methods are discussed.

  7. Intercomparison of four different in-situ techniques for ambient formaldehyde measurements in urban air

    Directory of Open Access Journals (Sweden)

    C. Hak

    2005-05-01

    Full Text Available Results from an intercomparison of several currently used in-situ techniques for the measurement of atmospheric formaldehyde (CH2O are presented. The measurements were carried out at Bresso, an urban site in the periphery of Milan (Italy as part of the FORMAT-I field campaign. Eight instruments were employed by six independent research groups using four different techniques: Differential Optical Absorption Spectroscopy (DOAS, Fourier Transform Infra Red (FTIR interferometry, the fluorimetric Hantzsch reaction technique (five instruments and a chromatographic technique employing C18-DNPH-cartridges (2,4-dinitrophenylhydrazine. White type multi-reflection systems were employed for the optical techniques in order to avoid spatial CH2O gradients and ensure the sampling of nearly the same air mass by all instruments. Between 23 and 31 July 2002, up to 13 ppbv of CH2O were observed. The concentrations lay well above the detection limits of all instruments. The formaldehyde concentrations determined with DOAS, FTIR and the Hantzsch instruments were found to agree within 11%, with the exception of one Hantzsch instrument, which gave systematically higher values. The two hour integrated samples by DNPH yielded up to 25% lower concentrations than the data of the continuously measuring instruments averaged over the same time period. The consistency between the DOAS and the Hantzsch method was better than during previous intercomparisons in ambient air with slopes of the regression line not significantly differing from one. The differences between the individual Hantzsch instruments could be attributed in part to the calibration standards used. Possible systematic errors of the methods are discussed.

  8. 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)

  9. 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

  10. Stabilizing operation point technique based on the tunable distributed feedback laser for interferometric sensors

    Science.gov (United States)

    Mao, Xuefeng; Zhou, Xinlei; Yu, Qingxu

    2016-02-01

    We describe a stabilizing operation point technique based on the tunable Distributed Feedback (DFB) laser for quadrature demodulation of interferometric sensors. By introducing automatic lock quadrature point and wavelength periodically tuning compensation into an interferometric system, the operation point of interferometric system is stabilized when the system suffers various environmental perturbations. To demonstrate the feasibility of this stabilizing operation point technique, experiments have been performed using a tunable-DFB-laser as light source to interrogate an extrinsic Fabry-Perot interferometric vibration sensor and a diaphragm-based acoustic sensor. Experimental results show that good tracing of Q-point was effectively realized.

  11. The improvement of phycocyanin stability extracted from Spirulina sp using extrusion encapsulation technique

    Science.gov (United States)

    Suzery, Meiny; Hadiyanto, Sutanto, Heri; Soetrisnanto, Danny; Majid, Dian; Setyawan, Deny; Azizah, Nur

    2015-12-01

    The stability of phycocyanin extracted from microalgae Spirulina has been evaluated and it showed that the stability of this antioxidant was affected by temperature and pH changes. The encapsulation technique was of the alternatives to overcome this stability changes. The objective of this paper was to investigate the effects of coating materials (alginate and chitosan) during encapsulation by using extrusion technique. The experiments were conducted with variation of alginate as coating materials. The size of each microcapsules was evaluated by using SEM/XRD for its size and homogeneity.

  12. X-Ray Photoresist Characterization Using in Situ Optical Monitoring Techniques

    Science.gov (United States)

    Sullivan, Monroe Brian

    X-ray photoresists were studied using two in situ optical techniques (ellipsometry and imaging interferometry) during development. A conventional photoresist (polymethylmethacrylate/KTI Chemicals) and two chemically-amplified photoresists (XP -90104C/Shipley and AZ-PF/Hoechst) were investigated. Computer programs were used to model the effects of surface roughening, swelling, and dissolution of these resists. A 2048 channel linear CCD array dissolution rate monitor (DRM) was constructed and tested on Shipley XP -90104C photoresist. A simple empirical model of surface roughening was proposed based on SEM and AFM images of the partially developed resist surface. Continuous resist contrast, sensitivity, time to clear, and normalized remaining thickness (NRT) curves were all calculated from a single wafer and used to characterize the photoresist. In addition, it was found that a reduction of 1/2 of the maximum fringe height in the DRM reflectivity signal corresponded to RMS surface roughening of 120 nm. The DRM was also used on PMMA to measure the spatial inhomogeneity of various X -ray exposure window materials used to isolate the UHV environment. The Be window studied had significantly more exposure field variation (+/-5%) than the poly-Si window (+/-1%). Vibrating the Be window during exposure reduced the exposure variation to +/-1%. A 3-color Rudolph AutoEL II ellipsometer and immersion cell were employed to monitor photoresists during development. PMMA was used to verify the results of previous studies, the validity of the technique, and the theoretical models. The technique was then applied to Shipley XP-90104C. Because XP-90104C uses an aqueous-base developer in situ ellipsometry was employed to test the assumption that the resist does not swell during development. No appreciable swelling of exposed XP-90104C was observed in Shipley MF-322 developer for temperatures below 35^circC, but the process of dissolution departed slightly from a theoretical model of uniform film dissolution. AFM and SEM images of partially developed samples revealed that surface roughening of the resist may account for the departure. An effective medium approximation (EMA) model was used to model the roughened surface layer. Measurements performed at 633nm and 546nm were accurately fit using the EMA model with surface roughness which increased proportional to the square root of time.

  13. 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)

  14. 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

  15. Establishment of the genomic in situ hybridization (GISH) technique for analysis in interspecific hybrids of Passiflora.

    Science.gov (United States)

    Melo, C A F; Silva, G S; Souza, M M

    2015-01-01

    The genomic in situ hybridization (GISH) technique was applied to Passiflora interspecific F1 HD13-133 hybrids (Passiflora sublanceolata x Passiflora foetida) and HD15-101 (Passiflora gardineri x Passiflora gibertii), and the backcrossed hybrids (BC1) HD18-106 and HD18-113 (Passiflora sublanceolata x HD13-133). GISH was performed using genomic probes prepared with the DNA from the paternal genitor, whereas the maternal DNA was used as blocking DNA and employed at various concentrations (20X, 40X, 60X, and 100X) in relation to the probe concentration. At the same time, GISH was applied with the use of simultaneous probes from both genomes, paternal and maternal, that were detected with avidin-FITC and anti-digoxigenin-rhodamine, respectively. Both methodologies allowed the distinguishing of the maternal and paternal genomes, thus confirming the hybrid nature of all the analyzed genotypes. Furthermore, the presence of recombinant chromosomes in BC1 hybrids revealed the occurrence of meiotic recombination in HD13 hybrids. This application of the GISH technique is an important step towards genomic analyses of Passiflora hybrids: it can broaden the phylogenetic and evolutionary studies of the genus and, at the same time, contribute to breeding programs. PMID:25867365

  16. 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

  17. 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.

  18. 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.

  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. An Experimental Study of In-Situ Phase Fraction in Jet Pump Using Electrical Resistance Tomography Technique

    Science.gov (United States)

    Xu, Jing-Yu; Wang, Mi; Wu, Ying-Xiang; Schlaberg I., H.; Zheng, Zhi-Chu; Williams A., R.

    2007-02-01

    We perform the experiments to investigate in-situ phase fraction in a jet pump using the electrical resistance tomography (ERT) technique. A new jet pump with ERT sensors is designed to measure in-situ phase fraction and flow regime. The study is based on laboratory experiments that are carried out on a 50-mm vertical flow rig for various gas and liquid phase superficial velocities. The different flow patterns of gas liquid in the jet pump and vertical pipe are studied using the ERT technique. The results suggest that the ERT system can be used to successfully produce images of gas-liquid flow patterns with frames rates of 58 fps and the in-situ phase fraction with frame rates of 5 fps can be obtained. The visualizations of a rapid mixing process in the throat of a jet pump obtained in this work provide a reliable basis for theoretical study and optimal design of jet pumps.

  1. An optimization technique of robust load frequency stabilizer for superconducting magnetic energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Ngamroo, Issarachai [Electrical Power Engineering Program, Sirindhorn International Institute of Technology, Thammasat University, P.O. Box 22, Pathumthani 12121 (Thailand)]. E-mail: ngamroo@siit.tu.ac.th

    2005-11-15

    As an interconnected power system is subjected to rapid load disturbances with changing frequencies in the vicinity of the inter-area oscillation mode, a system frequency may be heavily disturbed and oscillate. Under the circumstances, the stabilizing effect of the conventional load frequency control (LFC), i.e. a governor, cannot be expected. To compensate for such load disturbances and stabilize frequency oscillations, the active power controlled by superconducting magnetic energy storage (SMES) can be applied. In this paper, a new optimization technique of a robust load frequency stabilizer equipped with SMES is presented. To enhance the robustness of the load frequency stabilizer against system uncertainties such as various load changes, system parameters variations etc., the multiplicative uncertainty is included in the system modeling. As a result, the robust stability of the stabilized system can be easily guaranteed in terms of the multiplicative stability margin (MSM). The configuration of the load frequency stabilizer is practically based on a second order lead/lag compensator with a single feedback input. The control parameters are automatically optimized by a tabu search algorithm, so that the desired damping ratio of the target inter-area mode and the best MSM are achieved. The simulation study exhibits the high robustness of the load frequency stabilizer against uncertainties. Moreover, a SMES unit requires small power capacity for frequency stabilization.

  2. An optimization technique of robust load frequency stabilizer for superconducting magnetic energy storage

    International Nuclear Information System (INIS)

    As an interconnected power system is subjected to rapid load disturbances with changing frequencies in the vicinity of the inter-area oscillation mode, a system frequency may be heavily disturbed and oscillate. Under the circumstances, the stabilizing effect of the conventional load frequency control (LFC), i.e. a governor, cannot be expected. To compensate for such load disturbances and stabilize frequency oscillations, the active power controlled by superconducting magnetic energy storage (SMES) can be applied. In this paper, a new optimization technique of a robust load frequency stabilizer equipped with SMES is presented. To enhance the robustness of the load frequency stabilizer against system uncertainties such as various load changes, system parameters variations etc., the multiplicative uncertainty is included in the system modeling. As a result, the robust stability of the stabilized system can be easily guaranteed in terms of the multiplicative stability margin (MSM). The configuration of the load frequency stabilizer is practically based on a second order lead/lag compensator with a single feedback input. The control parameters are automatically optimized by a tabu search algorithm, so that the desired damping ratio of the target inter-area mode and the best MSM are achieved. The simulation study exhibits the high robustness of the load frequency stabilizer against uncertainties. Moreover, a SMES unit requires small power capacity for frequency stabilization

  3. 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.

  4. In situ characterization of catalytic activity of graphene stabilized small-sized Pd nanoparticles for CO oxidation

    International Nuclear Information System (INIS)

    The room-temperature ionic liquid assisted sputtering method is utilized to achieve the Pd-nanoparticle (NP)–graphene hybrid. The supported Pd NPs possess uniformly small sizes of 1–2 nm, which create huge surface area with ultralow Pd consumption and high NP stability. The Pd-NP–graphene hybrid is in situ characterized by the ambient pressure X-ray photoelectron spectroscopy using synchrotron radiation, and the results demonstrate high catalytic activity of the hybrid for CO oxidation. The catalytic behavior is reproducible for several catalytic cycles. The present simple and clean approach is promising to produce metal-NP-based high-efficiency catalysts for CO oxidation

  5. The stability of chalk during flooding of carbonated sea water at reservoir in-situ conditions

    Science.gov (United States)

    Nermoen, Anders; Korsnes, Reidar I.; Madland, Merete V.

    2014-05-01

    Injection of CO2 into carbonate oil reservoirs has been proposed as a possible utilization of the captured CO2 due to its capability to enhance the oil recovery. For offshore reservoirs such as Ekofisk and Valhall it has been discussed to alternate the CO2 and sea water injection (WAG) to reduce costs and keep the beneficial effects of both sea water (SSW) and gas injection. Water and CO2 mix to form carbonic acids that enhance the solubility of carbonates, thus a serious concern has been raised upon the potential de-stabilization of the reservoirs during CO2 injection. In this study we focus on how carbonated sea water alters the mechanical integrity of carbonate rocks both to evaluate safety of carbon storage sites and in the planning of production strategies in producing oil fields since enhanced compaction may have both detrimental and beneficial effects. Here we will present results from long term experiments (approx. half year each) performed on Kansas outcrop chalk (38-41% porosity), which serves as model material to understand the physical and chemical interplaying processes taking place in chalk reservoirs. All tests are performed at uni-axial strain conditions, meaning that the confining radial stresses are automatically adjusted to ensure zero radial strain. The tests are performed at in-situ conditions and run through a series of stages that mimic the reservoir history at both Ekofisk and Valhall fields. We observe the strain response caused by the injected brine. The experimental stages are: (a) axial stress build-up by pore pressure depletion to stresses above yield with NaCl-brine which is inert to the chalk; (b) uni-axial creep at constant axial stresses with NaCl-brine; (c) sea water injection; and (d) injection of carbonated water (SSW+CO2) at various mixture concentrations. Two test series were performed in which the pore pressure was increased (re-pressurized) before stage (c) to explore the stress dependency of the fluid induced strain triggering. The main findings of our investigations are: 1. The creep rate in the plastic phase is pore fluid dependent. The injection of sea water induces a period of accelerating creep. 2. The injection of CO2 and sea water reduces the deformation rate, a result which is in contrast to what has previously been shown. 3. The solid weight of the plugs is maintained during flooding which indicates that the observed carbonate dissolution at the inlet side is counteracted with secondary precipitation, possibly calcium sulphate, within the plug. These recent obtained results show that chalk cores maintain their mechanical integrity during flooding of carbonated water. This experimental study, however, separates from earlier studies by the low injection rate which allows secondary precipitation processes to equilibrate within the plugs, chalk type, test temperature, and stress conditions, which all are factors that will affect the reported dynamics.

  6. 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

  7. 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, cole Polytechnique Fdrale 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.

  8. 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.

  9. 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 CeSiO matrix during annealing due to interfacial reactions, which are supposed to stabilize the partially reduced ceria system

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

    Science.gov (United States)

    Gonalves, 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

  11. 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

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

    Scientific Electronic Library Online (English)

    Nbia Inocencya Pavesi, Pini; Dbora Alves Nunes Leite, Lima; Renato Herman, Sundfeld; Glucia Maria Bovi, Ambrosano; Flvio Henrique Baggio, Aguiar; Jos 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.

  13. 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

  14. 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

  15. 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

  16. 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-princip...

  17. 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...

  18. Transient Stability Analysis of Power System by Coordinated PSS-AVR Design Based on PSO Technique

    OpenAIRE

    Rostami, M.; Hassan Mehrjadi; A. D. Falehi

    2011-01-01

    In this paper, Power System Stabilizer (PSS) and Automatic Voltage Regulator (AVR) are coordinated to improve the transient stability of generator in power system. Coordinated design problem of AVR and PSS is formulated as an optimization problem. Particle Swarm Optimization (PSO) technique is an advanced robust search method by the swarming or cooperative behavior of biological populations mechanism. The performance of PSO has been certified in solution of highly non-linear objectives. Thus,...

  19. 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.

  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. Rapid detection of chromosome X, Y, 13, 18, and 21 aneuploidies by primed in situ labeling/synthesis technique

    Directory of Open Access Journals (Sweden)

    Ashutosh Halder

    2013-01-01

    Full Text Available Aims and Objective: Primed in situ labeling/synthesis (PRINS technique is an alternative to fluorescent in situ hybridization for chromosome analysis. This study was designed to evaluate the application of PRINS for rapid diagnosis of common chromosomal aneuploidy. Materials and Methods : We have carried out PRINS using centromere specific oligonucleotide primers for chromosome X, Y, 13, 18 and 21 on lymphocyte metaphase and interphase cells spread. Specific primer was annealed in situ, followed by elongation of primer by Taq DNA polymerase in presence of labeled nucleotides. Finally, reaction was stopped and visualized directly under fluorescent microscope. Results: Discrete centromere specific signals were observed with each primer. Conclusion: PRINS seems to be a rapid and reliable method to detect common chromosome aneuploidy in peripheral blood lymphocyte metaphase and interphase cells.

  2. Study of techniques for prospecting and exploration of in-situ leachable sandstone-type uranium deposits in China

    International Nuclear Information System (INIS)

    Being aimed at metallogenic features and exploration targets of in-situ leachable sandstone-type uranium deposits, this paper summarizes a set of methods and techniques for fast prospecting and exploration of sandstone-type uranium deposits at different stage geologic work, such as: target area selection, comprehensive assessment of promising areas and direct localization of subsurface ore bodies. In the meantime, authors briefly introduce the application potential and integrated application of GIS, modern remote sensing techniques, various kinds of geophysical and geochemical methods and techniques to prospecting and exploration of sandstone-type uranium deposits. (authors)

  3. 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.

  4. 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 (612 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.

  5. 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.

  6. Tcnicas in situ de baixo custo em eletroqumica: a microbalana 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.

  7. The development of sensors and techniques for in situ water quality monitoring

    Science.gov (United States)

    Liu, C. C.

    1976-01-01

    Enzyme electrodes and chloride ion electrodes were investigated for in situ monitoring of water quality. Preliminary results show that miniature chloride ion electrodes and a phenol sensor are most promising in determining trace contaminants in water.

  8. Styrene grafted natural rubber reinforced by in situ silica generated via solgel technique

    International Nuclear Information System (INIS)

    Highlights: Solgel 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 solgel 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

  9. 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 UVvis 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 UVvis 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 UVvis absorption spectra, also show dependence on the blend composition for AgCS/PVA colloids as well as for AgCS/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 UVvis spectra by Tauc's expression

  10. 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.

  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. An offset tone based gain stabilization technique for mixed-signal RF measurement systems

    Science.gov (United States)

    Joshi, Gopal; Motiwala, Paresh D.; Randale, G. D.; Singh, Pitamber; Agarwal, Vivek; Kumar, Girish

    2015-09-01

    This paper describes a gain stabilization technique for a RF signal measurement system. A sinusoidal signal of known amplitude, phase and close enough in frequency is added to the main, to be measured RF signal at the input of the analog section. The system stabilizes this offset tone in the digital domain, as it is sampled at the output of the analog section. This process generates a correction factor needed to stabilize the magnitude of the gain of the analog section for the main RF signal. With the help of a simple calibration procedure, the absolute amplitude of the main RF signal can be measured. The technique is especially suited for a system that processes signals around a single frequency, employs direct signal conversion into the digital domain, and processes subsequent steps in an FPGA. The inherent parallel signal processing in an FPGA-based implementation allows a real time stabilization of the gain. The effectiveness of the technique is derived from the fact, that the gain stabilization stamped to the main RF signal measurement branch requires only a few components in the system to be inherently stable. A test setup, along with experimental results is presented from the field of RF instrumentation for particle accelerators. Due to the availability of a phase synchronized RF reference signal in these systems, the measured phase difference between the main RF and the RF reference is also stabilized using this technique. A scheme of the signal processing is presented, where a moving average filter has been used to filter out not only the unwanted frequencies, but also to separate the main RF signal from the offset tone signal. This is achieved by a suitable choice of sampling and offset tone frequencies. The presented signal processing scheme is suitable to a variety of RF measurement applications.

  13. Stabilization and in situ management of radioactive contaminated sediments of Port Hope harbor

    International Nuclear Information System (INIS)

    This paper presents the findings of laboratory and field studies undertaken to assess the feasibility of in situ management of contaminated sediments in Port Hope harbor. The contaminated sediments stem from historic releases from an adjacent radium and uranium refinery, and uranium, arsenic, and radium are the most abundant contaminants. With improved emission controls, currently accumulating sediments have much lower levels of contamination, and the harbor waters currently meet water quality limits for the contaminants of concern. Within a few years, however, the continuing sedimentation will render the harbor unusable. Field tests have confirmed the dredging will result in incomplete removal of the contaminated sediments and that sediment suspension and the release of pores waters during dredging will produce harbor water contaminant concentrations that would require the treatment of large volumes of water. In addition, no remedial work can start until a site for the dredged material can be found. The local community inquired whether in situ burial of the sediments and abandonment of the harbor would provide safe disposal

  14. Polluted soils with heavy metals. Stabilization by magnesium oxide. Ex-situ and in-situ testings; Suelos contaminados con metales pesados. Estabilizacion con oxido de magnesio. Ensayos ex situ-in situ

    Energy Technology Data Exchange (ETDEWEB)

    Cenoz, S.; Hernandez, J.; Gangutia, N.

    2004-07-01

    This work describes the use of Low-Grade MgO as a stabiliser agent for polluted soil reclaim. Low-Grade MgO may be an economically feasible alternative in the stabilisation of heavy metals from heavily contaminated soils. The effectiveness of Low-Grade MgO has been studied in three ex-situ stabilisation of heavily polluted soils contaminated by the flue-dust of pyrite roasting. LG-MgO provides an alkali reservoir guaranteeing long-term stabilisation without varying the pH conditions. The success of the ex-situ stabilisation was corroborated with the analysis of heavy metals in the leachates collected from the landfill o ver a long period of time. The study also includes the results obtained in an in-situ pilot scale stabilisation of contaminated soil. (Author) 17 refs.

  15. 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.

  16. A Technique for In-situ Measurement of Free Spectral Range and Transverse Mode Spacing of Optical Cavities

    OpenAIRE

    Stochino, Alberto; Arai, Koji; Adhikari, Rana X.

    2012-01-01

    Length and g-factor are fundamental parameters that characterize optical cavities. We developed a technique to measure these parameters in-situ by determining the frequency spacing between the resonances of fundamental and spatial modes of an optical cavity. Two laser beams are injected into the cavity, and their relative frequency is scanned by a phase-lock loop, while the cavity is locked to either laser. The measurement of the amplitude of their beat note in transmission reveals the resona...

  17. Following the transient reactions in lithium-sulfur batteries using an in situ nuclear magnetic resonance technique.

    Science.gov (United States)

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

    2015-05-13

    A fundamental understanding of electrochemical reaction pathways is critical to improving the performance of Li-S batteries, but few techniques can be used to directly identify and quantify the reaction species during disharge/charge cycling processes in real time. Here, an in situ (7)Li NMR technique employing a specially designed cylindrical microbattery was used to probe the transient electrochemical and chemical reactions occurring during the cycling of a Li-S system. In situ NMR provides real time, semiquantitative information related to the temporal evolution of lithium polysulfide allotropes during both discharge/charge processes. This technique uniquely reveals that the polysulfide redox reactions involve charged free radicals as intermediate species that are difficult to detect in ex situ NMR studies. Additionally, it also uncovers vital information about the (7)Li chemical environments during the electrochemical and parasitic reactions on the Li metal anode. These new molecular-level insights about transient species and the associated anode failure mechanism are crucial to delineating effective strategies to accelerate the development of Li-S battery technologies. PMID:25785550

  18. Empleo de la tcnica hibridacin in situ fluorescente para visualizar microorganismos / Use of fluorescence in situ hybridization technique to visualize microorganisms

    Scientific Electronic Library Online (English)

    Ral, Rodrguez Martnez.

    2011-12-01

    Full Text Available La hibridacin in situ fluorescente (FISH), es una tcnica que emplea sondas de oligonucletidos marcadas con fluorocromos las cuales van dirigidas hacia secuencias especficas del cido ribonucleico ribosomal (ARNr), lo que permite la identificacin rpida y especfica de clulas microbianas ya sea [...] que estn como clulas individuales o se encuentren agrupadas en su ambiente natural. El conocimiento de la composicin y distribucin de los microorganismos en los hbitats naturales, proporciona un soporte slido para comprender la interaccin entre las diversas especies que componen el micro hbitat. El objetivo de la revisin es presentar la forma como ha evolucionado la hibridacin, el empleo del ARNr como molcula diana, los tipos de marcaje, los marcadores fluorescentes empleados hoy en da, la metodologa, as como las mejoras que se le han hecho a la tcnica FISH al emplearse en conjunto con otras tcnicas en la identificacin 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

  19. 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)

  20. 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)

  1. 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

  2. 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.

  3. 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

  4. Techniques for assessing the performance of in situ bioreduction and immobilization of metals and radionuclides in contaminated subsurface environments

    Energy Technology Data Exchange (ETDEWEB)

    Jardine, P.M.; Watson, D.B.; Blake, D.A.; Beard, L.P.; Brooks, S.C.; Carley, J.M.; Criddle, C.S.; Doll, W.E.; Fields, M.W.; Fendorf, S.E.; Geesey, G.G.; Ginder-Vogel, M.; Hubbard, S.S.; Istok, J.D.; Kelly, S.; Kemner, K.M.; Peacock, A.D.; Spalding, B.P.; White, D.C.; Wolf, A.; Wu, W.; Zhou, J.

    2004-11-14

    Department of Energy (DOE) facilities within the weapons complex face a daunting challenge of remediating huge below inventories of legacy radioactive and toxic metal waste. More often than not, the scope of the problem is massive, particularly in the high recharge, humid regions east of the Mississippi river, where the off-site migration of contaminants continues to plague soil water, groundwater, and surface water sources. As of 2002, contaminated sites are closing rapidly and many remediation strategies have chosen to leave contaminants in-place. In situ barriers, surface caps, and bioremediation are often the remedial strategies of chose. By choosing to leave contaminants in-place, we must accept the fact that the contaminants will continue to interact with subsurface and surface media. Contaminant interactions with the geosphere are complex and investigating long term changes and interactive processes is imperative to verifying risks. We must be able to understand the consequences of our action or inaction. The focus of this manuscript is to describe recent technical developments for assessing the performance of in situ bioremediation and immobilization of subsurface metals and radionuclides. Research within DOE's NABIR and EMSP programs has been investigating the possibility of using subsurface microorganisms to convert redox sensitive toxic metals and radionuclides (e.g. Cr, U, Tc, Co) into a less soluble, less mobile forms. Much of the research is motivated by the likelihood that subsurface metal-reducing bacteria can be stimulated to effectively alter the redox state of metals and radionuclides so that they are immobilized in situ for long time periods. The approach is difficult, however, since subsurface media and waste constituents are complex with competing electron acceptors and hydrogeological conditions making biostimulation a challenge. Performance assessment of in situ biostimulation strategies is also difficult and typically requires detailed monitoring of coupled hydrological, geochemical/geophysical, and microbial processes. In the following manuscript we will (1) discuss contaminant fate and transport problems in humid regimes, (2) efforts to immobilize metals and radionuclides in situ via bioremediation, and (3) state-of-the-art techniques for assessing the performance of in situ bioreduction and immobilization of metals and radionuclides. These included (a) in situ solution and solid phase monitoring, (b) in situ and laboratory microbial community analysis, (c) noninvasive geophysical methods, and (d) solid phase speciation via high resolution spectroscopy.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. HIBRIDACIN IN SITU PARA LA DETECCIN 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 ms serios en la acuicultura mundial. En Colombia la enfermedad afecta de manera importante las explotaciones de tilapia. Se estandariz la tcnica de hibridacin in situ (HIS) en tejidos de tilapia previamente identificados como positivos a la p [...] resencia de S. agalactiae por la tcnica de inmunoperoxidasa indirecta (IPI) y microbiologa. Se obtuvo seal positiva en el interior de los granulomas con una especificidad del 100%. Se logr amplificar significativamente la seal mediante el uso de la tiramida. La HIS en tejidos de tilapia puede ser usada para el diagnstico y estudios de patogensis y epidemiolgicos con este microorganismo. Se requieren futuras investigaciones para optimizar la marcacin de las bacterias libres en los tejidos y evaluar la sensibilidad de la tcnica. 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.

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

    Directory of Open Access Journals (Sweden)

    S. Panda

    2007-06-01

    Full Text Available 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 loading conditions with various fault disturbances and fault clearing sequences as well as for various small disturbances. The eigenvalue analysis and simulation results show the effectiveness and robustness of proposed controllers to improve the stability performance of power system by efficient damping of low frequency oscillations under various disturbances.

  12. 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

  13. In-situ Measurement of Two-Phase Fraction in Jet-Pump Using the ERT Technique

    Science.gov (United States)

    Xu, J. Y.; Wang, M.; Wu, Y. X.; Zheng, Z. C.; Schlaberg, H. I.; Williams, R. A.

    2007-06-01

    Due to the complexity of two-phase flow field in jet-pump, it is of difficult to accurately measure in-situ phase fraction in the pump. Electrical resistance tomography (ERT) has been successfully used in predicting gas concentration, dispersed phase velocity and flow regimes in both vertical and horizontal flows. Thus, the present study carried out an experimental investigation of in-situ the phase fraction in a jet-pump using the ERT technique. A new jet-pump with ERT sensors was designed to measure in-situ phase fraction and flow regime. The study was based on laboratory experiments that were carried out on a 50 mm vertical flow rig for various gas and liquid phase superficial velocities. A total of 6 experimental tests were conducted. The flow pattern of gas-liquid in the jet-pump was studied using the ERT technique. Results suggest the flow patterns recognition using ERT systems can not only be applied for most two-phase flow regimes, but also for the visualisation of a complex system. Furthermore, the visualizations of a rapid mixing process in the throat of a jet pump obtained in the present work provide a reliable basis for theoretical study and optimal design of jet pumps.

  14. In situ observations on the austenite stability in TRIP-steel during tensile testing

    Energy Technology Data Exchange (ETDEWEB)

    Kruijver, S.; Zhao, L. [Netherlands Inst. for Metals Research, Delft (Netherlands); Sietsma, J. [Materials Science and Technology, Delft Univ. of Technology (Netherlands); Offerman, E. [Materials Science and Technology, Delft Univ. of Technology (Netherlands); Interfaculty Reactor Inst., Delft Univ. of Technology (Netherlands); Dijk, N. van [Interfaculty Reactor Inst., Delft Univ. of Technology (Netherlands); Margulies, L. [European Synchrotron Radiation Facility (France); Materials Research Dept., Riso National Lab. (Denmark); Lauridsen, E.; Poulsen, H. [Materials Research Dept., Riso National Lab. (Denmark); Grigull, S. [European Synchrotron Radiation Facility (France); Zwaag, S. van der [Netherlands Inst. for Metals Research, Delft (Netherlands); Materials Science and Technology, Delft Univ. of Technology (Netherlands)

    2002-07-01

    In-situ deformation tests have been performed on a steel displaying the transformation-induced plasticity (TRIP) effect, while monitoring the phase transformation by means of X-ray diffraction. A tensile stress is applied to 0.4 mm thick samples of this steel with mass contents of 0.26% Si, 1.5% Mn, and 1.8% Al in a transmission geometry for a synchrotron-radiation beam of 25 {mu}m . 25 {mu}m. On the diffraction patterns every grain appears as a discrete spot. The austenite {l_brace}200{r_brace} reflections are analysed during this investigation. The diffraction patterns are treated like a powder pattern for five different {eta}-angles, with {eta} representing the angle between the tensile direction and the normal direction of the diffracting {l_brace}200{r_brace} planes. The results of the analysis show that {eta} = 0 and {eta} = 90 are the preferential orientations for the transformation to martensite. The Ludwigson and Burger model is used to gain more information about the stress dependence of the deformation induced martensite formation. The microdiffraction patterns also reveal the changes in carbon concentration in austenite at each retained austenite fraction. (orig.)

  15. In situ observations on the mechanical stability of austenite in TRIP-steel

    Science.gov (United States)

    Kruijver, S. O.; Zhao, L.; Sietsma, J.; Offerman, S. E.; van Dijk, N. H.; Lauridsen, E. M.; Margulies, L.; Grigull, S.; Poulsen, H. F.; van der Zwaag, S.

    2003-03-01

    In-situ tensile deformation tests have been performed on a high Al TRIP steel (composition 0.26 wt. % Si, 1.5 wt. % Mn, and 1.8 wt. % Al) displaying the transformation-induced plasticity (TRIP) effect, while monitoring the phase transformation by means of X-ray microdiffraction in transmission geometry. Due to the small beam size (25 ? m 25 ? m) every retained austenite grain appears as a discrete spot on the diffraction patterns. The diffraction patterns are treated like a powder pattern for different ?-angles, with ? representing the angle between the tensile direction and the normal direction of the diffracting {200} planes. The disappearance of austenite {200} reflections is analyzed during as a function of the imposed stress and orientation. Grains with ? = 0 or 90^{circ} tend to transform to martensite more easily. A unique feature of this microdiffraction experiment is the possibility of detecting the average carbon concentration of the retained austenite as a function of stress. Direct proof has been obtained that austenite with a lower carbon content x_c transforms at lower stress levels. The average x_c increases from 1.0 to 1.05 wt. %. This increase indicates a relatively narrow distribution of the carbon content.

  16. 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

  17. 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.

  18. A new in situ technique for studying deformation and fracture in thin film ductile/brittle laminates

    International Nuclear Information System (INIS)

    A new technique for studying deformation and fracture of thin film ductile/brittle laminates is described. The laminates are prepared by sputtering a brittle coating on top of an electropolished TEM thin foil. The composites are then strained in situ in the TEM. In this preliminary investigation, the composites consisted of a ductile aluminum substrate and a brittle silicon coating. Cracks in the brittle film grew discontinuously in bursts several micrometers in length. The crack opening displacement initiated plastic deformation in the ductile film, thus dissipating energy and allowing crack arrest. The interface was well bonded, and delamination was not observed. Due to the good interfacial bond and the crack opening behind the crack tip, it was possible to study very large plastic deformations and ductile fracture in the aluminum in situ, without buckling of the foil. The possibility of micromechanical modeling of the fracture behavior is briefly discussed. (orig.)

  19. Fine and Ultrafine Particles from Combustion Sources - Investigations with in-situ techniques

    Energy Technology Data Exchange (ETDEWEB)

    Pagels, Joakim

    2005-04-01

    Fine airborne particles are associated with adverse health effects in the human population. The aim of this research was to develop and evaluate methods for in-situ characterisation of fine and ultrafine particles and to determine their deposition in the human airways. The aim was also to increase knowledge about health and environmentally relevant properties of aerosols from biomass combustion and selected indoor sources. The methods include instrumental techniques such as Scanning Mobility Particle Sizer (SMPS), Electrical Low-Pressure Impactor (ELPI), Aerodynamic Particle Sizer (APS) and Tandem Differential Mobility Analysers (TDMA) based on volatility and hygroscopic growth. Filter samplers and impactors were used for collecting particles on substrates for subsequent chemical analysis. Emissions from local district heating plants (0.5-12 MW), based on moving grate combustion of woody fuels, were sampled with a dilution system and characterised. Particles from the indoor sources of cigarettes, incense and candles were examined in the laboratory by using an airtight 22 m{sup 3} stainless steel chamber. A set-up to determine respiratory deposition in humans was constructed. It was automatised and uses an electrical mobility spectrometer with an improved inversion algorithm to perform fast measurements of particles of different sizes in the inhaled and exhaled air. It was evaluated on human test-persons. The investigated biomass combustion sources emit high concentrations of fine and ultrafine particles. The chemical composition is dominated by KCl and K{sub 2}SO{sub 4}; Zn, Cd and Pb were also quantified. Elemental carbon was identified in particles larger than 150 nm during periods of incomplete combustion. The particle concentration depends on the fuel ash content and the combustion efficiency. The aerosol is essentially internally mixed with hygroscopic growth factors significantly higher than reported for diesel exhaust and environmental tobacco smoke. The particles restructure from agglomerates to a more compact shape upon first exposure to moderately high relative humidity. This results in an increase in effective density and fractal dimension. Hygroscopic growth of these particles reduces the respiratory dose by a factor of 3 compared to hydrophobic particles of the same size. The biomass combustion particles mainly consist of soluble ash components and need to be treated differently in future health effect assessments compared to particles from incomplete combustion, e.g. from diesel engines, wood stoves and cigarette smoke. Side stream cigarette and incense smoke are well internally mixed aerosols dominated by organic compounds. Each particle consists of components with a relatively wide range in vapour pressure. The volatile fraction decreases at lower particle concentrations in the chamber and upon ageing, which is attributed to different degrees of evaporation from the particle to the gas phase. Four different particle types were identified in emissions from candles. The feasibility of the ELPI and the APS to assess mass size distributions was investigated. It was found that the measurement quality is dependent on the size distribution of the aerosol. The set-up for respiratory deposition has low inherent particle losses. Determinations of precision, accuracy and sensitivity show that it can be used for field measurements in typical urban and indoor environments. Methods for characterisation of aerosols containing fine and ultrafine particles have been developed, evaluated and applied. The results can be used to improve exposure assessments in toxicological and epidemiological studies and for risk assessments.

  20. 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.

  1. 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.

  2. 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

  3. 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...

  4. 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 (1252 g CH4/m2 d) were significantly higher than fluxes from the other lysimeters (019 g CH4/m2 d) during in situ aeration. Regarding water balance, lysimeters covered with compost and compost-sand mixture, showed the lowest leachate rate (1826% 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 (2745% 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.

  5. 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.

  6. 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)

  7. Studies of ferroelectric heterostructure thin films, interfaces, and device-related processes via in situ analytical techniques.

    Energy Technology Data Exchange (ETDEWEB)

    Aggarwal, S.; Auciello, O.; Dhote, A. M.; Gao, Y.; Gruen, D. M.; Im, J.; Irene, E. A.; Krauss, A. R.; Muller, A. H.; Ramesh, R.

    1999-06-29

    The science and technology of ferroelectric thin films has experienced an explosive development during the last ten years. Low-density non-volatile ferroelectric random access memories (NVFRAMS) are now incorporated in commercial products such as ''smart cards'', while high permittivity capacitors are incorporated in cellular phones. However, substantial work is still needed to develop materials integration strategies for high-density memories. We have demonstrated that the implementation of complementary in situ characterization techniques is critical to understand film growth and device processes relevant to device development. We are using uniquely integrated time of flight ion scattering and recoil spectroscopy (TOF-ISARS) and spectroscopic ellipsometry (SE) techniques to perform in situ, real-time studies of film growth processes in the high background gas pressure required to growth ferroelectric thin films. TOF-ISARS provides information on surface processes, while SE permits the investigation of buried interfaces as they are being formed. Recent studies on SrBi{sub 2}Ta{sub 2}O{sub 9} (SBT) and Ba{sub x}Sr{sub 1{minus}x}TiO{sub 3} (BST) film growth and interface processes are discussed. Direct imaging of ferroelectric domains under applied electric fields can provide valuable information to understand domain dynamics in ferroelectric films. We discuss results of piezoresponse scanning force microscopy (SFM) imaging for nanoscale studies of polarization reversal and retention loss in Pb(Zr{sub x}Ti{sub 1{minus}x})O{sub 3} (PZT)-based capacitors. Another powerful technique suitable for in situ, real-time characterization of film growth processes and ferroelectric film-based device operation is based on synchrotrons X-ray scattering, which is currently being implemented at Argonne National Laboratory.

  8. Development of in-situ laser based cutting technique for shock absorber rear nut in pressurized heavy water reactors. CP-2.1

    International Nuclear Information System (INIS)

    We have developed a laser based cutting technique for shock absorber rear nuts in pressurized heavy water reactors (PHWRs). This technique has been successfully used for in-situ laser cutting at RAPS-3 reactor. The technique consists of a motorized compact fixture, which holds a fiber optic beam delivery cutting nozzle and can be operated remotely

  9. Single-chamber, in situ processing of superconducting YBa2Cu3O7-? thin films on stainless steel with yttria-stabilized zirconia buffer layer

    International Nuclear Information System (INIS)

    Single-chamber in situ laser processing of high-Tc YBa2Cu3O7-? film on stainless steel (302) substrates with yttria-stabilized zirconia (YSZ) buffer layers, has been carried out using a multitarget deposition system. YSZ and YBa2Cu3O7-? films were deposited sequentially by KrF excimer laser (?=248 nm) at substrate temperature of 650 degree C. The films were characterized by x-ray diffraction, four point probe ac electrical resistivity, scanning electron microscopy and Auger electron spectroscopy (AES) techniques. Due to the matching of the thermal expansion coefficient of YSZ with stainless steel and its diffusion barrier characteristics, good quality high-Tc films have been grown on stainless steel substrates with superconducting transition temperature, Tc (onset), of 92 K and Tco (zero resistivity temperature) of 84 K. AES depth profiling indicated little interdiffusion of Fe across the interface of YSZ and stainless steel. A laser evaporation method was used for patterning the YBa2Cu3O7-? films and critical current density, Jc, was measured to be ?5x104 Acm-2 at 40 K. It was observed that the zero resistivity temperature significantly changed with the variation of buffer layer thickness, buffer layer processing temperature, and ambient oxygen partial pressure during the deposition of YBa2Cu3O7-?

  10. 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.

  11. Does the Implant Surgical Technique Affect the Primary and/or Secondary Stability of Dental Implants? A Systematic Review

    OpenAIRE

    Rola Muhammed Shadid; Nasrin Rushdi Sadaqah; Sahar Abdo Othman

    2014-01-01

    Background. A number of surgical techniques for implant site preparation have been advocated to enhance the implant of primary and secondary stability. However, there is insufficient scientific evidence to support the association between the surgical technique and implant stability. Purpose. This review aimed to investigate the influence of different surgical techniques including the undersized drilling, the osteotome, the piezosurgery, the flapless procedure, and the bone stimulation by low-...

  12. Modified stabilization method for the tibial tuberosity advancement technique: a biomechanical study

    Directory of Open Access Journals (Sweden)

    Bruno Testoni Lins

    2009-04-01

    Full Text Available 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.

  13. 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...

  14. 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.

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

    Science.gov (United States)

    Malumbres, A.; Martnez, G.; Hueso, J. L.; Gracia, J.; Mallada, R.; Ibarra, A.; Santamara, 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

  16. 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

  17. 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.

  18. Establishment of 60Co dose calibration curve using fluorescent in situ hybridization assay technique: Result of preliminary study

    International Nuclear Information System (INIS)

    This study aims at establishing an in-vitro 60Co dose calibration curve using Fluorescent In-Situ Hybridization assay technique for the Malaysian National Bio dosimetry Laboratory. Blood samples collected from a female healthy donor were irradiated with several doses of 60Co radiation. Following culturing of lymphocytes, microscopic slides are prepared, denatured and hybridized. The frequencies of translocation are estimated in the metaphases. A calibration curve was then generated using a regression technique. It shows a good fit to a linear-quadratic model. The results of this study might be useful in estimating absorbed dose for the individual exposed to ionizing radiation retrospectively. This information may be useful as a guide for medical treatment for the assessment of possible health consequences. (author)

  19. Study of oxide scale on Ti-base alloys by XPS and in-situ AES techniques

    International Nuclear Information System (INIS)

    The oxide scale on Ti-base alloys in pH9 water at 300 degree C was investigated by X-Ray Diffraction (XRD), X-Ray Photoelectron Spectrometry (XPS) and in-situ Auger Electron Spectroscopy (AES) techniques. The XPS result showed the chemical state of titanium changed with the depth: Ti4+ appeared near the surface of the oxide scale. As the depth increased, Ti3+(Tl2O3) and Ti2+(TiO) appeared. At first the percentages of Ti3+ was more than Ti2+, then there was more Ti2+ than Ti3+ when the depth was increased. The XRD spectroscopy and In-situ AES technique showed that the oxide scale formed on Ti-base alloys was composed of Al2TiO5, TiO2, Ti3O5, Ti2O3, Al2O3 and TiO. The depth profiles obtained by AES showed that the flat part appeared at first part of the profile near surface, and revealed that a stable layer of brookite (TiO2) was formed. The compact thick 5000 Angstrom scale with the mixture of brookite-TiO2 and Al2TiO5 was formed near surface, and the total thickness of oxide scale was about 30000 Angstrom

  20. Transport critical current of solenoidal MgB2/Cu coils fabricated using a wind-reaction in situ technique

    International Nuclear Information System (INIS)

    In this letter, we report the results on transport Jc of solenoid coils of up to 100 turns fabricated with Cu-sheathed MgB2 wires using a wind-reaction in situ technique. Despite the low density of the single core and some reaction between the Mg and Cu sheaths, our results demonstrate that the decrease in transport Jc with increasing length of MgB2 wires is insignificant. Solenoid coils with diameter as small as 10 mm can be readily fabricated using a wind-reaction in situ technique. The Jc of the coils is essentially the same as that of comparable straight wires. A Jc of 133000 A cm-2 and 125000 A cm-2 at 4 K and self-field has been achieved for a small coil wound using Cu-sheathed tape and Cu-sheathed wire, respectively. These results indicate that MgB2 wires have a great potential for large-scale applications. (rapid communication)

  1. 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)

  2. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Arzubiaga, L.; Llopis, R. [CIC nanoGUNE, Tolosa Hiribidea 76, 20018 Donostia, San Sebastian, Basque Country (Spain); Golmar, F. [I.N.T.I. – CONICET and ECyT-UNSAM, San Martín, Bs As (Argentina); Casanova, F.; Hueso, L. E. [CIC nanoGUNE, Tolosa Hiribidea 76, 20018 Donostia, San Sebastian, Basque Country (Spain); IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Basque Country (Spain)

    2014-11-15

    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.

  4. 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.

  5. 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)

  6. 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 Hansjrg 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.

  7. Enhancement of the stability of the flow focusing technique for low-viscosity liquids

    International Nuclear Information System (INIS)

    We propose a modified flow focusing configuration to produce low-viscosity microjets at much smaller flow rates than those reached by the standard configuration. In the modified flow focusing device, a sharpened rod blocks the recirculation cell appearing in the tapering liquid meniscus for low flow rates, which considerably improves its stability. We measured the minimum flow rates attainable with the modified configuration and compared the results with the corresponding values for the standard technique. For moderate and large applied pressure drops, the minimum flow rate reached with the modified configuration was about five times smaller than its counterpart in the standard configuration. The Weber numbers of the jets produced with the modified flow focusing configuration were considerably smaller than those with the standard technique. Numerical simulations were conducted to show how the presence of the inner rod substantially changes the flow pattern in the liquid meniscus. (paper)

  8. Predicting thermal stability of organic solar cells through real-time capacitive techniques (Presentation Recording)

    Science.gov (United States)

    Tessarolo, Marta; Guerrero, Antonio; Seri, Mirko; Prosa, Mario; Bolognesi, Margherita; Garcia Belmonte, Germ

    2015-10-01

    Bulk Heterojunction (BHJ) solar cells have reached Power Conversion Efficiencies (PCE) over 10% but to be a competitive product long lifetimes are mandatory. In this view, guidelines for the prediction and optimization of the device stability are crucial to generate improved materials for efficient and stable BHJ devices. For encapsulated cells, degradation mechanisms can be mainly ascribed to external agents such as light and temperature. In particular, thermal degradation appears to be related not only to the BHJ morphology but also to the adjacent interfaces. Therefore, in order to have a complete description of the thermal stability of a BHJ cell, it is necessary to consider the entire stack degradation processes by using techniques enabling a direct investigation on working devices. Here, five different donor polymers were selected and the OPV performance of the corresponding BHJ devices were monitored during the thermal degradation at 85C, showing an exponential decay of the corresponding PCEs. In parallel, we measured the geometrical capacitance of analogous OPV devices as a function of temperature and we observed that at a defined temperature (TMAX), typical for each polymer-based device, the capacitance starts to decrease. Combining all these results we found an evident and direct correlation between TMAX and the PCE decay parameters (obtained from capacitance-temperature an thermal measurements, respectively). This implies that the capacitance-method here presented is a fast, reliable and relatively simple method to predict the thermal stability of BHJ solar cells without the need to perform time-consuming thermal degradation tests.

  9. 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

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

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

    Science.gov (United States)

    Wagner, D.; Brgardts, M.; Grnzweig, C.; Lehmann, E.; Mller, 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.

  16. A new tracer technique for in situ experimental study of bioturbation processes

    International Nuclear Information System (INIS)

    An experimental method has been developed to study material and radioactivity fluxes at the sediment-water interface and in the sedimentary column. This method has been applied in the Gulf of Fos, an area that is affected by deposits from the river Rhone, and where biodeposition products, resulting from the presence of intensive mussel cultures, can induce a concentration of trace elements at the sediment-water interface. Sediment surface materials were labelled with a mixture of radionuclides (Cerium-144, Cobalt-60 and Cesium-137), in experimental cores filled either with sediment containing in situ fauna or with defaunated sediment. The coupling of this mixture with inert colored sediment particles enabled us to measure radionuclide flux in both solute fraction and solid fraction. At the sediment-water interface, the tracer balance indicates that migrations into deeper sediment are estimated to be until 25 times greater in presence of macrofauna, depending on the tracer examined. Bioturbation may equally enhance exportation to the water column, to a factor ranging from 1.5 to 2.0. During a period of 14 days, in presence of macrofauna, we observed a migration of radionuclides to a maximum depth of 11 cm. A similar distribution pattern of luminophores at the same sediment depths indicates the preponderance of particle reworking in migration. (Author)

  17. CT imaging techniques for two-phase and three-phase in-situ saturation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, B.C.; Brigham, W.E.; Castanier, L.M.

    1997-06-01

    The aim of this research is to use the SUPRI 3D steam injection laboratory model to establish a reliable method for 3-phase in-situ saturation measurements, and thereafter investigate the mechanism of steamflood at residual oil saturation. Demiral et al. designed and constructed a three dimensional laboratory model that can be used to measure temperature, pressure and heat loss data. The model is also designed so that its construction materials are not a limiting factor for CT scanning. We have used this model for our study. In this study, we saturated the model with mineral oil, and carried out waterflood until residual oil saturation. Steamflood was then carried out. A leak appeared at the bottom of the model. Despite this problem, the saturation results, obtained by using 2-phase and 3-phase saturation equations and obtained from the Cat scanner, were compared with the saturations obtained from material balance. The errors thus obtained were compared with those obtained by an error analysis carried out on the saturation equations. This report gives details of the experimental procedures, the data acquisition and data processing computer programs, and the analysis of a steamflood experiment carried out at residual oil saturation.

  18. A novel fluidized bed respirometric technique for determination of in situ biofilm kinetics.

    Science.gov (United States)

    Chowdhury, Nabin; Nakhla, George; Zhu, Jesse

    2012-01-01

    A respirometric approach has been developed to determine heterotrophic biofilm kinetics using fluidized bioparticles--particles with attached biomass. Lava rock particles of 600 microm were used as a biomass carrier medium. The modified respirometer successfully estimates in situ biofilm kinetics of the bioparticles collected from a pilot-scale liquid-solid circulating fluidized bed (LSCFB) bioreactor. The observed maximum specific growth rates (micro(max)) of 3.69 +/- 0.44 d(-1) and biomass yields (Y(H)) of 0.36 +/- 0.03 g COD/g COD in the fluidized bed respirometers were significantly different from the micro(max) of 5.57-5.72 d(-1) and Y(H) of 0.54-0.59 g COD/g COD observed in the conventional respirometric tests for bioparticles and detached biomass. The higher Monod half-saturation coefficient (K(S)) of 186-219mg COD/L observed in the fluidized bed respirometers relative to the 49-58 mg COD/L in the conventional respirometers reveals the presence of mass transfer resistance in the LSCFB despite fluidization. Significantly reduced yields in the fluidized bed respirometers and the estimated maintenance coefficient of 1.16 d(-1) for the particulate biofilm in the LSCFB clearly emphasize that a substantial amount of substrate was utilized for cell maintenance at the low food to microorganism (S/X) ratio of 0.5 g COD/g VSS. PMID:22629617

  19. 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)

  20. 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.

  1. 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.

  2. 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.

  3. 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 DT 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)

  4. 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

  5. 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)

  6. Coating stresses in thermal barrier coatings by an in-situ curvature monitoring technique

    International Nuclear Information System (INIS)

    In this paper, coating stresses in thermal barrier coating (TBC) changing with cyclic heating - cooling are measured with a curvature measurement device developed in this study. The coating system chosen in this study is a dual-layered structure, and it consists of a partially stabilized zirconia (PSZ) as the ceramic coating layer and CoNiCrAlY as the metal-bond coating layer. The specimen used here is a strip-plate shape with thin thickness (600?m) extracted chemically from carbon steel coated by a thermal spraying process. A cyclic heating-cooling test and a cyclic heating-cooling test with a dwelling time at the maximum temperature are conducted for the strip-plate specimen. Deflection and coating stresses are measured continuously under these cyclic tests, and thermal deformation mechanisms generating the deflection and coating stresses are discussed based on primitive knowledge using an elementary beam theory. (author)

  7. 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, Andr

    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

  8. Steel research using neutron beam techniques. In-situ neutron diffraction, small-angle neutron scattering and residual stress analysis

    International Nuclear Information System (INIS)

    Recently, the neutron beam techniques have been applied for steel researches and industrial applications. In particular, the neutron diffraction is a powerful non-destructive method that can analyze phase transformation and residual stress inside the steel. The small-angle neutron scattering is also an effective method for the quantitative evaluation of microstructures inside the steel. In this study, in-situ neutron diffraction measurements during tensile test and heat treatment were conducted in order to investigate the deformation and transformation behaviors of TRIP steels. The small-angle neutron scattering measurements of TRIP steels were also conducted. Then, the neutron diffraction analysis was conducted on the high strength steel weld joint in order to investigate the effect of the residual stress distribution on the weld cracking. (author)

  9. 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.

  10. Fluorescent immunohistochemistry and in situ hybridization analysis of mouse pancreas using low-power antigen-retrieval technique.

    Science.gov (United States)

    Ge, Shundi; Crooks, Gay M; McNamara, George; Wang, Xiuli

    2006-07-01

    To facilitate the immunological reaction of antibodies with antigens in fixed tissues, it is necessary to unmask or retrieve the antigens through pretreatment of the specimens. However, adjustment of heating-induced antigen retrieval is always required for different tissues and antigens. In this study, by using a low-power antigen-retrieval technique with appropriate dilution of antibodies, we successfully immunostained key antigens in pancreas such as insulin, PDX-1, glucagon, cytokeratin, and CD31, which have previously presented a particular challenge for investigators because of the rapid autodigestion and high nonspecific antibody binding in this tissue. Satisfactory results were obtained when immunohistochemistry and fluorescence in situ hybridization analysis were combined in the same slides. PMID:16549508

  11. 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.

  12. In situ preparation of Y 1Ba 2Cu 4O 8 thin films by the laser ablation technique

    Science.gov (United States)

    Badaye, M.; Kanke, Y.; Fukushima, K.; Morishita, T.

    1994-10-01

    Thin films of Y 1Ba 2Cu 4O 8 have been prepared by the laser ablation of sintered Y 1Ba 2Cu 4O 8 targets, followed by a short in situ oxygen annealing. The films obtained under optimum conditions show a high degree of phase purity compared to the films obtained by the other methods. The films' surface morphology has been studied by atomic force microscopy (AFM), their crystalline structure was examined by the X-ray diffraction (XRD) method, and their transport characteristics have been measured by the DC four-probe technique. It is shown that the fabricated films are of high enough quality to be considered for device applications.

  13. 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.

  14. Flow characterization of electroconvective micromixer with a nanoporous polymer membrane in-situ fabricated using a laser polymerization technique.

    Science.gov (United States)

    Hwang, Sangbeom; Song, Simon

    2015-05-01

    Electroconvection is known to cause strong convective mixing in a microchannel near a nanoporous membrane or a nanochannel in contact with an electrolyte solution due to the external electric field. This study addresses micromixer behavior subject to electroconvection occurring near a nanoporous membrane in-situ fabricated by a laser polymerization technique on a microfluidic chip. We found that the micromixer behavior can be categorized into three regimes. Briefly, the weak electroconvection regime is characterized by weak mixing performance at a low applied voltage and KCl concentration, whereas the strong electroconvection regime has a high mixing performance when the applied voltage and KCl concentration are moderately high. Finally, the incomplete electroconvection regime has an incomplete electric double-layer overlap in the nanopores of the membrane when the electrolyte concentration is very high. The mixing index reached 0.92 in the strong electroconvection regime. The detailed fabrication methods for the micromixer and characterization results are discussed in this paper. PMID:26064195

  15. Application of fluorescence in situ hybridization technique in the diagnosis of acute promyelocytic leukemia with abnormal immunophenotype

    International Nuclear Information System (INIS)

    To evaluate the utilization of fluorescence in situ hybridization (FISH) technique in the diagnosis of acute promyelocytic leukemia(APL) with abnormal immunophenotype, flow cytometry was used to detect the immunophenotype of mononuclear cells in APL patients and PML/RAR? fusion gene was detected by FISH. The mononuclear cells of several APL patients showed abnormal immunophenotype: CD13+ , CD33+ , CD34-, HLA-DR+ and PML/RAR? fusion gene was also detected, which was different from the regular result of APL: HLA- DR-, PML/RAR?+. Therefore, the detection of immunophenotype in APL patients should not be regarded as the sole accurate target for diagnosing leukemia. FISH ,associated with traditional FAB classification, is a simple, rapid, accurate and direct method. It can be used to help confirm the diagnosis, to guide the formulation of a reasonable chemotherapy scheme and to supervise the efficacy of the treatment in patients with leukemia. (authors)

  16. 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

  17. 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.

  18. In situ sorbtion techniques for radiocaesium. Rapid group separation and measurement of actinides

    International Nuclear Information System (INIS)

    Full text: a) A technique for impregnation of filters with copperferrocyanide has been developed. The sorbtion of radiocaesium has been tested on different types of liquids containing radiocaesium; urine (1-2 l), lake, river and sea water (100-2000 l) and dialysis liquid (120 l). The efficiency and analytical results were investigated and compared with results using ammonium molybdophosphate for sorbtion of caesium. Results are in good agreement with volumes not exceeding 500 I using two consecutive filters. Assessment of radiocaesium in large groups of people can be done rapidly by sorbtion from urine. Persons with malfunctioning kidneys and undergoing regular dialysis do not constitute a critical group. Dialysis is an effective method for cleaning the blood from radiocaesium. b) Actinides can be grouped separately from the bulk of solids using anion exchange from polar solvent-mineral acid media. This method is known since long. In combination with new techniques for source preparation using fluoride precipitation and new measurement techniques, mass spectrometry, laser excitation or gridded ion chambers (if sources have to be large) offers a possibility to shorten the analytical method. 2) Proposed Work for the Next Year: Decontamination of iodine (131I) from the body using dialysis will be investigated. Also other radiologically important radionuclides, 210Po and 226Ra will be investigated with this emphasis. Source preparation by fluoride precipitation and large area sources measured with gridded ionization chamber will be executed. (author)

  19. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Borsaru, M.; Charbucinski, J. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Kenmore, QLD (Australia). Exploration and Mining

    1997-10-01

    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 refs., 7 figs.

  1. Comparacin de las tcnicas in situ, in vitro y enzimtica (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, Carceln C.; Orlando, Lucas A..

    Full Text Available Se compar los resultados de las tcnicas in vitro, in situ y enzimtica (celulasa) para estimar la digestibilidad de forrajes de diferente calidad nutritiva en ovinos. Se colect 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 tcnica in vitro y celulasa y 3 mm para la tcnica in situ. Se determin 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 fstula ruminal y alimentados con maz forrajero y heno de alfalfa. Se us un diseo experimental con arreglo factorial de 4 x 3 (4 calidades de forraje y 3 tcnicas). 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

  2. 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.

  3. 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.

  4. Interaction mechanics of embedded single-ended optical fibre sensors using novel in situ measurement techniques

    Science.gov (United States)

    Leblanc, Michel Joseph

    This thesis presents an investigation of the mechanics of axial strain transfer and interfacial failure for optical fibre strain sensors embedded within a host material. This study focuses on single-ended embedded optical fibre sensors: In this configuration, the optical fibre is terminated within the host material and the region near the embedded end is an area where large interfacial radial and shear stresses are present. Our investigation is both theoretical and experimental. For the theory, finite element as well as analytical models are used. In particular, a fracture-mechanics-based model of the debonding of the embedded optical fibre is proposed. Experimentally, two new techniques are developed to study the sensor/host interaction. Both involve using an optical fibre to make measurements of its own interaction with the host material in which it is embedded. In the first approach, the Fabry-Prot gap measurement technique, the displacement of the embedded optical fibre end is measured as a function of applied load. Information concerning the sensor/host interaction is gained from its analysis. In the second approach, the Bragg distributed strain sensing technique, the strain profile along the optical fibre from its tip to a distance 2 to 6 mm further along the optical fibre is obtained by the analysis of the full reflection spectrum of the grating. Several types of samples are tested. The results obtained show that the silica/epoxy and polyimide/epoxy interfaces are stronger than the silica/polyimide interface. Yielding of materials (plastic failure) is observed as an important failure mode and it is also observed that debonding of the silica/polyimide interface strongly depends on the state of residual radial stress in the optical fibre. This crucial effect of radial stress on the failure mechanism is also a key result of the theoretical modeling.

  5. A study on in-situ measuring method and modeling technique of an unsaturated zone

    Energy Technology Data Exchange (ETDEWEB)

    Imai, Hisashi [Hazama Corp., Tsukuba, Ibaraki (Japan). Technical Research Inst.; Amemiya, Kiyoshi; Nishida, Kaoru; Lin, Weiren; Lei, Xinglin

    1997-03-01

    It is generally considered that an unsaturated zone is generated in the vicinity of a drift after excavation. In such a zone, invasion of air containing oxygen possibly changes geochemical environment (redox condition) of the rock mass. However, no measurement technique for quantitative understanding of this unsaturated zone is currently available. This study has been started to develop the measuring method in the several years. This year, fundamental information has been obtained through analysis, laboratory experiments using homogeneous rock samples and field measurement described below. (1) experiments on the mechanism of undersaturation in rock. (2) experiments on the measuring method of the extend of unsaturated zone. (author)

  6. 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...

  7. 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.

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

    Science.gov (United States)

    Germaneau, A.; Doumalin, P.; Dupr, J. C.; Brque, C.; Brmand, 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.

  9. Growth of Zn S single crystals by CVT technique under different mass transport stability conditions

    International Nuclear Information System (INIS)

    A thermodynamic model was used to find out the optimum temperature for the growth of Zn S single crystals in closed ampoules by chemical vapor transport technique. Based on this model 1002 degreeC was found to be optimum temperature for 2 mg/cm3 concentration of transporting agent (iodine). Zn S Crystals were grown in optimum (1102 degreeC) and non-optimum (902 degreeC and 1102 degreeC) temperatures. The composition structure and microstructure of the grown crystals were studied by Atomic absorption spectroscopy, X-ray diffraction and Scanning electron microscopy measurements. Properties of the grown crystals were correlated to the growth conditions especially a stability in mass transport along the closed tube length.

  10. 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

  11. 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.

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

    International Nuclear Information System (INIS)

    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 micro-hardness 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?m. (author)

  13. 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 √m.

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

    Energy Technology Data Exchange (ETDEWEB)

    Behringer, K.; Hennig, D

    2002-11-01

    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)

  15. 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.

  16. 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)

  17. 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.

  18. Quantifying in-situ gas hydrates at active seep sites in the eastern Black Sea using pressure coring technique

    Directory of Open Access Journals (Sweden)

    K. Heeschen

    2011-05-01

    Full Text Available In the eastern Black Sea, we determined methane (CH4 concentrations, gas hydrate volumes and their vertical distribution from combined gas and chloride (Cl? measurements within pressurized sediment cores. The total gas volume collected from the cores corresponds to concentrations of 1.21.4 mol of methane per kg porewater at in-situ pressure, which is equivalent to a gas hydrate saturation of 1518% of pore volume and amongst the highest values detected in shallow seep sediments. At the central seep site, a high-resolution Cl? profile resolves the upper gas hydrate stability boundary and a continuous layer of hydrates in a sediment column of 120 cm thickness. Including this information, a more precise gas hydrate saturation of 2224% pore volume can be calculated. This is higher in comparison to a saturation calculated from the Cl? profile alone, resulting in 14.4%. The likely explanation is an active gas hydrate formation from CH4 gas ebullition. The hydrocarbons at Batumi Seep are of shallow biogenic origin (CH4 > 99.6%, at Pechori Mound they originate from deeper thermocatalytic processes as indicated by the lower ratios of C1 to C2C3 and the presence of C5.

  19. 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.

  20. Probabilistic risk assessment techniques help in identifying optimal equipment design for in-situ vitrification

    International Nuclear Information System (INIS)

    The analysis discussed in this paper was performed as part of the buried waste remediation efforts at the Idaho National Engineering Laboratory (INEL). The specific type of remediation discussed herein involves a thermal treatment process for converting contaminated soil and waste into a stable, chemically-inert form. Models of the proposed process were developed using probabilistic risk assessment (PRA) fault tree and event tree modeling techniques. The models were used to determine the appropriateness of the conceptual design by identifying potential hazards of system operations. Additional models were developed to represent the reliability aspects of the system components. By performing various sensitivities with the models, optimal design modifications are being identified to substantiate an integrated, cost-effective design representing minimal risk to the environment and/or public with maximum component reliability. 4 figs

  1. An in-situ technique to measure erosion and deposition in fusion devices

    International Nuclear Information System (INIS)

    Erosion or deposition of sub-micron layers of graphite or other materials can be measured by bombarding a sub-surface layer of 10B or 6Li with thermal neutrons and observing with a surface-barrier detector the energy loss of the prompt alphas or tritons produced. To demonstrate the feasibility of this technique, a (5250250) A layer of boron and a (1.250.05) ?m layer of Li2B4O7 were electron-beam evaporated onto graphite substrates and exposed to a thermal neutron flux of (8.00.5)x105 cm-2 s-1. The (n, ?) reactions of the 10B produce a 1.78 MeV ?, a 1.48 MeV ?, and a 0.848 MeV 7Li. The reactions of 6Li produce a 2.73 MeV 3H and a 2.05 MeV ?. Carbon coatings of (60025) A, (8250500) A, (2.00.2) ?m, and (4.00.4) ?m were placed between the active layers and a surface barrier detector in vacuuo. The thinner layers shifted the 1.48 MeV ? peak by (31.74.5) keV and (43143) keV respectively. The thicker layers shifted the 2.73 MeV 3H peak by (20615) keV and (34620) keV respectfully. Therefore, utilizing boron implants, 100 A to 1 ?m of graphite erosion or redeposition can be determined. Utilizing lithium implants, thicknesses in the range of 1 ?m to 10 ?m can be determined. Theoretical energy shifts, thermal diffusion, and the feasibility of this technique as a between shot diagnostic for limiters, divertor plates, and/or first-wall armor are discussed. (orig.)

  2. 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.

  3. Transport critical current of Solenoidal MgB2/Cu Coils Fabricated Using a Wind-Reaction In-situ Technique

    OpenAIRE

    Soltanian, S.; Horvat, J.; Wang, X. L.; Tomsic, M.; Dou, S.X.

    2002-01-01

    In this letter, we report the results of transport Jc of solenoid coils upto 100 turns fabricated with Cu-sheathed MgB2 wires using a wind-reaction in-situ technique. Despite the low density of single core and some reaction between Mg and Cu-sheath, our results demonstrate the decrease in transport Jc with increasing length of MgB2 wires is insignificant. Solenoid coils with diameter as small as 10 mm can be readily fabricated using a wind-reaction in-situ technique. The Jc of coils is essent...

  4. 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

  5. Preliminary in situ and real-time study of directional solidification of metallic alloys by x-ray imaging techniques

    International Nuclear Information System (INIS)

    During directional solidification of a binary alloy, the solid-liquid interface exhibits a variety of patterns that are due to the Mullins-Sekerka instability and governed by the growth conditions. It is well known that properties of the grown material are largely controlled by the microstructures left in the solid during processing. Thus, a precise mastering of the solidification is essential to tailor products in a reproducible fashion to a specified quality. One major difficulty for this study is the real-time and in situ observation of the interface, especially for metallic alloys. A possibility is to use an intense and coherent third generation x-ray beam. By combining different x-ray imaging techniques (absorption/phase contrast radiography and diffraction topography), we have studied the directional melting and solidification of aluminium-based alloys. The preliminary results show the great potential of these techniques for the study of the coupling between stress effects and microstructure formation in solidification processing

  6. 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

  7. 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.

  8. 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.

  9. 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

  10. Stability analysis of resistive MHD modes via a new numerical matching technique

    International Nuclear Information System (INIS)

    Full text: Asymptotic matching technique is one of the principal methods for calculating linear stability of resistive magnetohydrodynamics (MHD) modes such as tearing modes. In applying the asymptotic method, the plasma region is divided into two regions: a thin inner layer around the mode-resonant surface and ideal MHD regions except for the layer. If we try to solve this asymptotic matching problem numerically, we meet practical difficulties. Firstly, the inertia-less ideal MHD equation or the Newcomb equation has a regular singular point at the mode-resonant surface, leading to the so-called big and small solutions. Since the big solution is not square-integrable, it needs sophisticated treatment. Even if such a treatment is applied, the matching data or the ratio of small solution to the big one, has been revealed to be sensitive to local MHD equilibrium accuracy and grid structure at the mode-resonant surface by numerical experiments. Secondly, one of the independent solutions in the inner layer, which should be matched onto the ideal MHD solution, is not square-integrable. The response formalism has been adopted to resolve this problem. In the present paper, we propose a new method for computing the linear stability of resistive MHD modes via matching technique, where the plasma region is divided into ideal MHD regions and an inner region with finite width. The matching technique using an inner region with finite width was recently developed for ideal MHD modes in cylindrical geometry, and good performance was shown. Our method extends this idea to resistive MHD modes. In the inner region, the low-beta reduced MHD equations are solved, and the solution is matched onto the solution of the Newcomb equation by using boundary conditions such that the parallel electric field vanishes properly as approaching the computational boundaries. If we use the inner region with finite width, the practical difficulties raised above can be avoided from the beginning. Figure 1 shows the growth rate of m/n = 2/1 tearing mode as a function of the width of the 'inner region' ?r. The growth rate is normalized by its value without the numerical matching. We see that the growth rate is calculated in a sufficient accuracy even for ?r = 0.1. In addition, the smaller resistivity ? allows thinner inner region. (author)

  11. 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

  12. In-situ calibration of criticality monitor in radioactive laboratories by shooting device technique

    International Nuclear Information System (INIS)

    Criticality safety is of utmost importance, where isotopes of fissile radioactive material (Pu, U, etc) handled in large quantities in different fuel fabrication facilities. In general, apart from mass control, geometry control in handling radioactive materials, administrative control is a necessity for smooth operation of the facilities. The point of concern in radioactive laboratories is 'criticality' situation. The criticality situation is associated with the burst of neutron and gamma radiation, The detector used to assess such an incident is either calibrated using neutron detection or gamma detection technique simulating the burst of neutron or gamma ray. These detectors should be calibrated and kept up to date to avoid such an incident. A burst of 1015 fission will deliver a prompt gamma dose of 2.5 mSv at a distance of 30 feet (9.144 m). Assuming, the dose delivered in 100 msec, the dose rate will be 102Sv/h, which shall involve in a change of six to seven decade from background in 100 msec. Thus, there are two methods for which a criticality monitor has to be calibrated: i) Steady state 1.3R/h ii) Integrated dose of 2.6 mrem in 200 msec. A source shooting device was designed which uses a cobalt (60Co) one Curie (Ci) source for calibration as per integrated dose limit, The total time of flight shall be ? 400 msec for the source with an adjustable average velocity of 8 to 10 m/sec. The velocity is achieved using pneumatic pressure, filled inside a container. The velocity can be varied depending upon the air pressure inside the cylinder. The system is designed with an impact absorber at the end, to reduce the force during impact which prevents it from bulging under successive flights. A reverse air purging system is designed to get cushioning effect to the source at the end of flight to avoid the flaring of the source. The device is tested using dummy source containers for structural integrity and leak tightness. The main feature of this system is its compactness and portability. (author)

  13. 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

  14. 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...

  15. 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...

  16. 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)

  17. 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.

  18. 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...

  19. Technique of stabilization of stress-strain state at a fatigue crack tip in specimens under pure bending

    International Nuclear Information System (INIS)

    A technique is described for stabilization of stress-strain conditions at a fatigue crack tip in rectangular section specimens, sub ected to pure bending under rigid loading. The technique includes the determination of reduced pliability for elastic parts of a testing machine; the choice of optimum parameters of a testing machine - specimen system; the determination of specimen dimensions. Testing of stress-strain state stabilization at a crack tip was carried out on 40Kh steel specimens. The investigation results correlate well with a calculated curve. A sraight portion of the fatigue crack growth curve testifies to constancy of a stress intensity factor

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. Intrinsic stress in ZrN thin films: Evaluation of grain boundary contribution from in situ wafer curvature and ex situ x-ray diffraction techniques

    International Nuclear Information System (INIS)

    Low-mobility materials, like transition metal nitrides, usually undergo large residual stress when sputter-deposited as thin films. While the origin of stress development has been an active area of research for high-mobility materials, atomistic processes are less understood for low-mobility systems. In the present work, the contribution of grain boundary to intrinsic stress in reactively magnetron-sputtered ZrN films is evaluated by combining in situ wafer curvature measurements, providing information on the overall biaxial stress, and ex situ x-ray diffraction, giving information on elastic strain (and related stress) inside crystallites. The thermal stress contribution was also determined from the in situ stress evolution during cooling down, after deposition was stopped. The stress data are correlated with variations in film microstructure and growth energetics, in the 0.13-0.42 Pa working pressure range investigated, and discussed based on existing stress models. At low pressure (high energetic bombardment conditions), a large compressive stress is observed due to atomic peening, which induces defects inside crystallites but also promotes incorporation of excess atoms in the grain boundary. Above 0.3-0.4 Pa, the adatom surface mobility is reduced, leading to the build-up of tensile stress resulting from attractive forces between under-dense neighbouring column boundary and possible void formation, while crystallites can still remain under compressive stress.

  7. 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.

  8. 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 FlynnWallOzawa 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.

  9. 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.

  10. 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.

  11. 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

    International Nuclear Information System (INIS)

    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 sp2 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. - Highlights: • Thermal stability of amorphous hydrogenated/deuterated layers has been studied. • In situ Raman spectroscopy linear ramp and long term isotherms have been recorded. • The effects of isotopic substitution have been investigated. • We confirm that the layers containing the more H or D are the less thermally stable. • 514 nm photon absorption evolves as the G band shifts

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

    International Nuclear Information System (INIS)

    Highlights: • Portland cement and lime activated persulfate by increasing pH and temperature. • Chemical oxidation achieved BTEX and PAH removal ranging from 55% to 75%. • Activating persulfate with ISS amendments reduced leachability more than NaOH. • Native sulfate-reducing bacteria degraded PAHs within weeks after ISCO finished. • ISCO, ISS, and anaerobic bioremediation were combined in a single application. - Abstract: 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

  13. 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 0.3-10m, respectively. The porosity, average pore size and pure water permeability of the zirconia membrane was estimated to be 42%, 0.66m and 1.4410(-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 2.2810(-5)m(3)/m(2)s at operating pressure of 68kPa. PMID:25982409

  14. 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 Dagrou; Christelle Guerret-Picourt; 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...

  15. 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...

  16. 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.

  17. 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.

  18. Forage Legume Seeds Submitted to in Vitro and in Situ Fermentation Techniques

    OpenAIRE

    Bruno B. Deminicis; Henrique D. Vieira; Joo C. C. Almeida; Saulo A. C. Arajo; Cesar C. Guimares Filho; Raphael P. Arajo; Deise D Castagnara; Deolindo Stradiotti Jnior

    2013-01-01

    The present study was carried out to evaluate the survival rate of four tropical legume seeds submitted to different periods of ruminal incubation simulated by in vitro and in situ fermentation. The species studied were butterfly pea, stylosanthes, archer and perennial soybean. Four Holstein dairy cows fistulated in rumen were used in the in situ stage. A completely randomized design was used, in a 4 6 factorial arrangement (four species, six treatment periods) in the in vitro stage, w...

  19. Determination of stability constants of iron(III and chromium(III-nitrilotriacetate-methyl cysteine mixed complexes by electrophoretic technique

    Directory of Open Access Journals (Sweden)

    Brij Bhushan Tewari

    2004-06-01

    Full Text Available The stability constants of Fe(III and Cr(III with methyl cysteine and nitrilotriacetate (NTA were determined by paper electrophoretic technique. Beside binary ternary complexes have also been studied, in which nitrilotriacetate and methyl cysteine acts as primary and secondary ligand, respectively. The stability constants of mixed ligand complexes metal (M-nitrilotriacetate-methyl cysteine have been found to be 5.72 plus or minus 0.09 and 5.54 plus or minus 0.11 (log K values for Fe(III and Cr(III complexes, respectively, at 35 oC and ionic strength 0.1 M.

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

    Scientific Electronic Library Online (English)

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

    2011-12-01

    Full Text Available La material seca (MS) y la desaparicin total de carotenoides del pasto estrella (PE) en el rumen e intestino del pasto estrella (PE) fueron medidas en 4 becerros Holstein, utilizando las tcnicas In situ en rumen y la de bolsas de nylon mviles en duodeno, respectivamente. Una alta proporcin 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

  1. 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; Joo-Carlos, Das-Neves-Pereira; Fernando Conrado, Abrao; Fbio 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.

  2. Biodegradable surfactant stabilized nanoscale zero-valent iron for in situ treatment of vinyl chloride and 1,2-dichloroethane

    International Nuclear Information System (INIS)

    Highlights: ? Biodegradable surfactant stabilized nanoscale zero-valent iron (NZVI) is tested. ? Vinyl chloride and 1,2-dichloroethane are remediated by NZVI in the field. ? Multiple functions of biodegradable surfactants are confirmed. ? Biodegradable surfactants stabilize NZVI and facilitate the bioremediation. ? NZVI creates reducing conditions beneficial to an anaerobic bioremediation. - Abstract: Nanoscale zero-valent iron (NZVI) stabilized with dispersants is a promising technology for the remediation of contaminated groundwater. In this study, we demonstrated the use of biodegradable surfactant stabilized NZVI slurry for successful treatment of vinyl chloride (VC) and 1,2-dichloroethane (1,2-DCA) in a contaminated site in Taiwan. The biodegradable surfactant stabilized NZVI was coated with palladium and synthesized on-site. From monitoring the iron concentration breakthrough and distribution, it was found that the stabilized NZVI is capable of transporting in the aquifer at the test plot (200 m2). VC was effectively degraded by NZVI while the 1,2-DCA degradation was relatively sluggish during the 3-month field test. Nevertheless, as 1,2-DCA is known to resist abiotic reduction by NZVI, the observation of 1,2-DCA degradation and hydrocarbon production suggested a bioremediation took place. ORP and pH results revealed that a reducing condition was achieved at the testing area facilitating the biodegradation of chlorinated organic hydrocarbons. The bioremediation may be attributed to the production of hydrogen gas as electron donor from the corrosion of NZVI in the presence of water or the added biodegradable surfactant serving as the carbon source as well as electron donor to stimulate microbial growth.

  3. 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 Hckel 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

  4. In situ formation of stabilizers for the implementation of dispersion nitroxide mediated polymerization of MMA in supercritical carbon dioxide

    OpenAIRE

    Grignard, Bruno; Gigmes, Didier; Jrme, Christine; Detrembleur, Christophe

    2009-01-01

    Controlled dispersion Nitroxide Mediated Polymerization (NMP) of methyl methacrylate (MMA) was successfully carried out for the first time in supercritical carbon dioxide (scCO2) in the presence of CO2-philic perfluorinated surfactant that was generated in situ. The control of the MMA polymerization relies on the strategy developed by Charleux et al. that consists of using a SG1-based alkoxyamine, i.e. the block-builder, in the presence of small amount of styrene. In a first step, CO2 solub...

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

    KAUST Repository

    Harms, Hauke A.

    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 TiO 2 films. For the first time, a molar ratio of co-adsorbed Y123 and chenodeoxycholic acid has been measured. 2012 the Owner Societies.

  6. Popliteal-to-Dorsalis Pedis In-Situ Small Saphenous Vein Bypass under Planning with Mapping Using Computed Tomography Volume Rendering Technique

    OpenAIRE

    Byun, Seung-Jae

    2015-01-01

    The small saphenous vein (SSV) is an important graft in limb salvage surgery. It is frequently translocated for bypass surgery. Sometimes, the use of the SSV as an in-situ graft for posterior tibial artery or peroneal artery reconstruction offers the advantages of reduced vein graft injury and improved patency. Recently, saphenous vein mapping through computed tomography (CT) volume rendering technique offers a great quality view to the surgeon. We experienced a patient in whom a CT image wit...

  7. 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...

  8. Effect of particle size on the pore characterization and strength of porous cordierite-mullite ceramics prepared by a pore-forming in-situ technique

    OpenAIRE

    Yan W.; Li N.; Tong J.; Liu G.; Xu J.

    2013-01-01

    The porous cordierite-mullite ceramics were prepared by the pore-forming in-situ technique. The characterizations of porous cordierite-mullite ceramics were determined by an X-ray diffractometer (XRD), a scanning electron microscopy (SEM), and a microscopy measured method, etc., and the effect of particle size on phase composition, pore characterization and strength were investigated. Its found that particle size affects strongly the formations of cordierite and mullite, and then chang...

  9. Primary stability in cementless total hip replacement: measurement techniques and aided-surgery

    OpenAIRE

    Varini, Elena

    2007-01-01

    Primary stability of stems in cementless total hip replacements is recognized to play a critical role for long-term survival and thus for the success of the overall surgical procedure. In Literature, several studies addressed this important issue. Different approaches have been explored aiming to evaluate the extent of stability achieved during surgery. Some of these are in-vitro protocols while other tools are coinceived for the post-operative assessment of prosthesis migratio...

  10. 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.

  11. 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 ...

  12. 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

  13. 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.

  14. 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...

  15. In situ precision electrospinning as an effective delivery technique for cyanoacrylate medical glue with high efficiency and low toxicity

    Science.gov (United States)

    Dong, R. H.; Qin, C. C.; Qiu, X.; Yan, X.; Yu, M.; Cui, L.; Zhou, Y.; Zhang, H. D.; Jiang, X. Y.; Long, Y. Z.

    2015-11-01

    The side effects or toxicity of cyanoacrylate used in vivo have been argued since its first application in wound closure. We propose an airflow-assisted in situ precision electrospinning apparatus as an applicator and make a detailed comparison with traditional spraying via in vitro and in vivo experiments. This novel method can not only improve operational performance and safety by precisely depositing cyanoacrylate fibers onto a wound, but significantly reduce the dosage of cyanoacrylate by almost 80%. A white blood cell count, liver function test and histological analysis prove that the in situ precision electrospinning applicator produces a better postoperative outcome, e.g., minor hepatocyte injury, moderate inflammation and the significant ability for liver regeneration. This in situ precision electrospinning method may thus dramatically broaden both civilian and military applications of cyanoacrylates.

  16. 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

  17. 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; Pgouri, 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.

  18. Dynamic Stability Improvement of Grid Connected DFIG Using Enhanced Field Oriented Control Technique for High Voltage Ride Through

    OpenAIRE

    V. N. Ananth Duggirala; V. Nagesh Kumar Gundavarapu

    2015-01-01

    Doubly fed induction generator (DFIG) is a better alternative to increased power demand. Modern grid regulations force DFIG to operate without losing synchronism during overvoltages called high voltage ride through (HVRT) during grid faults. Enhanced field oriented control technique (EFOC) was proposed in Rotor Side Control of DFIG converter to improve power flow transfer and to improve dynamic and transient stability. Further electromagnetic oscillations are damped, improved voltage mitigati...

  19. 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

  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. Technique for the numerical analysis of the riblet effect on temporal stability of plane flows

    Science.gov (United States)

    Boiko, A. V.; Nechepurenko, Yu. M.

    2010-06-01

    Problems related to the temporal stability of laminar viscous incompressible flows in plane channels with ribbed walls are formulated, justified, and numerically solved. A new method is proposed whereby the systems of ordinary differential and algebraic equations obtained after a spatial approximation are transformed into systems of ordinary differential equations with a halved number of unknowns. New algorithms that effectively calculate stability characteristics, such as the critical Reynolds numbers, the maximum amplification of the disturbance kinetic energy density, and optimal disturbances are described and substantiated. The results of numerical experiments with riblets similar in shape to those used in practice are presented and discussed.

  2. 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 agroup of patients with ahigh 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 apredictive value for drug targeted therapy. Overexpression of receptors and gene amplification has been reported in various cancers. Their detection is still aconsiderable 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 asuitable selection factors based on genetic aberrations profile. PMID:26469118

  3. 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.)

  4. 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

  5. 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

  6. 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

  7. In situ green synthesis of silvergraphene 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 AgGO nanocomposites exhibited excellent SERS activity. - Abstract: Silvergraphene oxide (AgGO) 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 AgGO nanocomposites were characterized by UVvis 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 AgGO 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}.

  8. 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 [Universit des Sciences et de la Technologie Houari Boumediene, Laboratoire des Matriaux Polymres, Facult de Chimie, BP 32 El-Alia, Bab-Ezzouar, 16111 Algiers (Algeria); Djadoun, Sad, E-mail: matpolylab@yahoo.fr [Universit des Sciences et de la Technologie Houari Boumediene, Laboratoire des Matriaux Polymres, Facult 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.

  9. 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)

  10. 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.

  11. 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...

  12. 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.

  13. 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.

  14. Rapid oxidation/stabilization technique for carbon foams, carbon fibers and C/C composites

    Science.gov (United States)

    Tan, Seng; Tan, Cher-Dip

    2004-05-11

    An enhanced method for the post processing, i.e. oxidation or stabilization, of carbon materials including, but not limited to, carbon foams, carbon fibers, dense carbon-carbon composites, carbon/ceramic and carbon/metal composites, which method requires relatively very short and more effective such processing steps. The introduction of an "oxygen spill over catalyst" into the carbon precursor by blending with the carbon starting material or exposure of the carbon precursor to such a material supplies required oxygen at the atomic level and permits oxidation/stabilization of carbon materials in a fraction of the time and with a fraction of the energy normally required to accomplish such carbon processing steps. Carbon based foams, solids, composites and fiber products made utilizing this method are also described.

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

    OpenAIRE

    Hajman 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 Baumgartes stabili...

  16. Edible moisture barriers: materials, shaping techniques and promises in food product stabilization

    OpenAIRE

    Bourlieu, Claire; Guillard, Valrie; Valls-Pmies, Baltasar; Gontard, N.

    2007-01-01

    Edible moisture barriers are effective alternatives to stabilize fresh or processed food products and satisfy consumers demand for long shelf-life products that are of good quality and nutritionally acceptable. This chapter deals with traditional and innovative film-forming materials and barrier technologies of edible films reporte d in scientific literature and patents over the last thirty years. The necessity of adopting an integrated approach in the development of edible moisture barri...

  17. Comparative study of different techniques of composting and their stability evaluation in municipal solid waste

    International Nuclear Information System (INIS)

    Spatial differences in the physical and chemical characteristics related to maturity of composted organic matter are strongly influenced by composting methods. For evaluation of compost maturity three locally fabricated composters (aerobic, mixed type, anaerobic) processes were examined at seven days interval up to 91 days by loading MSW along with bulking agent. Gradual changes in physico chemical characteristics (temperature, pH, moisture, CEC, humification) related to stability and maturity of compost were studied and compared. Increase in ammonia nitrogen level due to rise in temperature was maximum in aerobic process. Substantial increase in CEC in aerobic process was earlier which leads to establish the optimal degree of maturity as compared to other processes. FA and HI decrease rapidly as composting progressed. Optimal level in stability and maturity parameters like C:N, HA, DH and HR were attained earlier in aerobic process as compared to mixed type and anaerobic processes due to continuous aeration. The parameters (HR, DH, FA, HA), which indicate the compost stability were correlated among themselves. The parameters defining maturity such as CEC, ammonia nitrate and C:N ratio were also related to above mention parameters. The compost from the aerobic process provided good humus and micro nutrients. Result from this study will assist in method optimization and quality of the compost product. (author)

  18. 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.

  19. 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)

  20. 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.

  1. 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.

  2. 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.)

  3. 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.)

  4. Comparison of wind measurements in the troposphere and mesosphere by VHF/MF radars and in-situ techniques

    OpenAIRE

    Engler, N.; Singer, W.; Latteck, R.; Strelnikov, B.

    2008-01-01

    Radar wind observations at frequencies between 1.98 and 53.5 MHz obtained at polar latitudes were compared to in-situ wind measurements by radiosondes at tropospheric altitudes and to winds from falling spheres at mesospheric altitudes. Comparisons are shown for several campaigns of radiosonde and falling sphere observations. The radar wind directions agree well to the radiosonde and falling sphere observations and are highly correlated. The winds estimated from radar measurements are less th...

  5. 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...

  6. 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...

  7. A study on the annealing behavior of Cu-added bake-hardenable steel using an in situ EBSD technique

    International Nuclear Information System (INIS)

    A combination of electron backscatter diffraction and in situ heating was used to study the annealing behavior of Cu-added bake-hardenable (BH) steel. The annealing behavior of cold-rolled, Cu-added BH steel was strongly dependent on the type and number of average orientations developed in the deformed grains. If deformed grains (type I) had a single ?-fiber component as the average orientation of a unique grain (UG), the density of the nuclei was very low and recrystallization began at a later stage of the in situ annealing. However, the average grain size of the recrystallized grains was drastically increased regardless of the deformed grain as soon as recrystallization had begun. If deformed grains (type II) had multiple ?-fiber components as the average orientation of a UG, the density of the nuclei steadily increased as the elapsed time of in situ annealing increased. The area fraction of the recrystallized grains in the partially recrystallized specimens gradually increased, but the kinetics depended on the deformed matrix. However, the average grain size of the recrystallized grains gradually increased in all deformed grains from the beginning of in situ annealing. If deformed grains (type III) had texture components which could not be assigned to either ?-fiber or ?-fiber components as the average orientation of a UG, the number of the recrystallized grains was maximized, but the recrystallization kinetics based on a normalized number of recrystallized grains was similar to that of type II. Since type III was a minor deformed grain in the as-rolled Cu-added BH steel, the recrystallization in types I and II was identified as the principal feature determining the overall recrystallization phenomena of Cu-added BH steel

  8. Instrumentation and techniques for monitoring the air emissions during in-situ oil/fuel burning operations

    International Nuclear Information System (INIS)

    Data was presented from the testing of a portable real-time aerosol monitor during a meso-scale in-situ diesel fuel fire. The monitors tested were MIE Inc's., RAM-1 and DataRAM monitors which are commonly used in the occupational health and safety industry. They allow for the continuous measurement of aerosol levels. In-situ burning has evolved substantially in recent years and is considered to be a viable oil spill countermeasure. However, research continues regarding the environmental impact of in-situ burning. For this continuous monitoring study, three RAM-1 and two or three DataRAM monitors were placed in a cluster close to each other; data was recorded using an external data logger. The multiple values from the RAM-1 were averaged over a period of one minute. Results showed that the reproducibility of the average readings recorded during the trials were not at levels expected for scientific research. The results of the instruments clustered together was influenced by the location of the monitors relative to the particulates in the air. This would be of concern when comparing individual results to air quality standards. 8 refs., 5 tabs., 20 figs

  9. 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 fluctuations added to the ...

  10. 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

  11. The application of fluorescence in situ hybridization (FISH technique for studying the microbial communities in intestinal tissues of white shrimp (Penaeus vannamei

    Directory of Open Access Journals (Sweden)

    Supamattaya, K.

    2005-02-01

    Full Text Available Fluorescence in situ hybridization technique is very useful for the evaluation of microbial communities in various environments. It is possible to apply this technique to study the intestinal microflora in white shrimp (Penaeus vannamei. Different fixatives and storage temperature were tested in this technique. It was found that fixation with 10% buffered formalin for 12 hours and changed to 70% ethanol shown positive results when compared to the fixation with Davidson's fixative or RF fixative. The best signaling was obtainedfrom the samples which were stored in -20C. By using the DNA probe targeted to the Eubacteria domain (EUB338 probe, 5?-GCT GCC TCC CGT AGG AGT-3? labeled with fluorescein as a hybridizing probe, it was found that most intestinal microflora were aggregated with the intestinal contents, or dispersed in the lumen. There was not evidence of the attachment of the microflora with the intestinal epithelium in this study.

  12. Fiber Transmission Stabilization by Optical Heterodyning Techniques and Synchronization of Mode-Locked Lasers Using Two Spectral Lines

    CERN Document Server

    Staples, J W

    2005-01-01

    Stabilization of the transit time through a glass fiber using an optical heterodyne technique promises to provide jitter reduction down to the few femtosecond level using inexpensive commodity hardware. An acousto-optical frequency shifter provides the optical frequency offset that is used to downconvert phase shifts at optical frequency to equivalent phase shifts at radio frequency which are used to close a phase-lock loop driving a piezoelectric phase shifter. Using the stabilized fiber transmission medium, two spectral lines of a mode locked laser lock two low-power CW lasers which are transmitted to a receiver which phase locks the same spectral lines of a second mode-locked laser to the first. The optical transmission system operates at low power and is linear, providing excellent signal-to-noise ratio and allows many signals to be transmitted without mutual interference. Experimental results will be presented.

  13. 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.

  14. Investigations on dry sliding wear behavior of in situ casted AA7075TiC metal matrix composites by using Taguchi technique

    International Nuclear Information System (INIS)

    Highlights: The AA7075TiC 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

  15. 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

  16. 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 (612 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, ...

  17. Soot production from in-situ oil fires: review of the literature, measurement and estimation techniques and calculation of values from experimental spills

    International Nuclear Information System (INIS)

    Two methods of estimating soot production by in-situ oil and fuel fires were described. Much refining is needed in current measurement estimation techniques, since no method can accurately measure soot production from large-scale fires. One method which may have potential is the use of laser particle counters to count particles by size as they move overhead. Studies of oil and fuel fires have shown that there is significant gas separation between the plume and the surface, and that there is also significant soot precipitation out of the plume near the fire. Data from many burns has shown that the CO2 is often ten times lower in the plume than on the surface. Most estimation methods over-estimate soot production by as much as a factor of 10. The value of soot produced varies significantly down-plume because of the precipitation of material. True values, regarding soot production by in-situ oil fires are necessary to establish a mass balance of burning, to understand the air emissions of in-situ fires, and to establish guidelines for the burning of various fuels. 71 refs., 11 tabs., 8 figs

  18. Formulation and In-Vitro Evaluation of Controlled Release Tablet of Bupropion Hydrochloride by Direct Compression Technique and Stability Study

    OpenAIRE

    ANJAN PAUDEL; YOGENDRA RAJ PANDEY; SUBASH THA SHRESTHA; SUMIT CHANDRA SHRESTHA

    2014-01-01

    Purpose: The aim of the study was to develop and evaluate matrix based controlled drug delivery system by direct compression technique of Bupropion hydrochloride tablet and stability studies. Methods: Controlled release tablets were prepared by employing Eudragit RS 100, HPMC K15M, HPMC K100M at different concentration. Result and conclusion: All 10 batches pass friability, hardness, weight variation, assay but only three batches (CRB3D, CRB4D and CRB7D) passed the dissolution as per USP 30 N...

  19. Multi-level homotopy perturbation and projection techniques for the reanalysis of quadratic eigenvalue problems: The application of stability analysis

    Science.gov (United States)

    Massa, F.; Lallemand, B.; Tison, T.

    2015-02-01

    Complex eigenvalue analysis is widely used to investigate the stability of a dynamical system with frictional contact. For finite element models, iterative solvers are needed to precisely calculate complex modes and eigenvalues. However, in cases such as reanalysis studies, optimization or uncertainty propagation processes, computational cost can quickly become too time consuming. For multiple samplings, two methods combining homotopy perturbation and projection techniques are proposed for the reanalysis of quadratic eigenvalue problems. To highlight the efficiency of the proposed methods, a complete numerical application including nominal and perturbed solution calculations, coalescence graph and parametric analysis, is performed. The precision of results and computational time are compared with those obtained using commercial software.

  20. 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)

  1. 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

  2. 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 ...

  3. 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

  4. Optimizing molecular properties using a relative index of thermodynamic stability and global optimization techniques

    Science.gov (United States)

    Fournier, Ren; Mohareb, Amir

    2016-01-01

    We devised a global optimization (GO) strategy for optimizing molecular properties with respect to both geometry and chemical composition. A relative index of thermodynamic stability (RITS) is introduced to allow meaningful energy comparisons between different chemical species. We use the RITS by itself, or in combination with another calculated property, to create an objective function F to be minimized. Including the RITS in the definition of F ensures that the solutions have some degree of thermodynamic stability. We illustrate how the GO strategy works with three test applications, with F calculated in the framework of Kohn-Sham Density Functional Theory (KS-DFT) with the Perdew-Burke-Ernzerhof exchange-correlation. First, we searched the composition and configuration space of CmHnNpOq (m = 0-4, n = 0-10, p = 0-2, q = 0-2, and 2 ? m + n + p + q ? 12) for stable molecules. The GO discovered familiar molecules like N2, CO2, acetic acid, acetonitrile, ethane, and many others, after a small number (5000) of KS-DFT energy evaluations. Second, we carried out a GO of the geometry of Cu m Snn + (m = 1, 2 and n = 9-12). A single GO run produced the same low-energy structures found in an earlier study where each Cu m S nn + species had been optimized separately. Finally, we searched bimetallic clusters AmBn (3 ? m + n ? 6, A,B= Li, Na, Al, Cu, Ag, In, Sn, Pb) for species and configurations having a low RITS and large highest occupied Molecular Orbital (MO) to lowest unoccupied MO energy gap (Eg). We found seven bimetallic clusters with Eg > 1.5 eV.

  5. Optimizing molecular properties using a relative index of thermodynamic stability and global optimization techniques.

    Science.gov (United States)

    Fournier, Ren; Mohareb, Amir

    2016-01-14

    We devised a global optimization (GO) strategy for optimizing molecular properties with respect to both geometry and chemical composition. A relative index of thermodynamic stability (RITS) is introduced to allow meaningful energy comparisons between different chemical species. We use the RITS by itself, or in combination with another calculated property, to create an objective function F to be minimized. Including the RITS in the definition of F ensures that the solutions have some degree of thermodynamic stability. We illustrate how the GO strategy works with three test applications, with F calculated in the framework of Kohn-Sham Density Functional Theory (KS-DFT) with the Perdew-Burke-Ernzerhof exchange-correlation. First, we searched the composition and configuration space of CmHnNpOq (m = 0-4, n = 0-10, p = 0-2, q = 0-2, and 2 ? m + n + p + q ? 12) for stable molecules. The GO discovered familiar molecules like N2, CO2, acetic acid, acetonitrile, ethane, and many others, after a small number (5000) of KS-DFT energy evaluations. Second, we carried out a GO of the geometry of CumSnn (+) (m = 1, 2 and n = 9-12). A single GO run produced the same low-energy structures found in an earlier study where each CumSnn (+) species had been optimized separately. Finally, we searched bimetallic clusters AmBn (3 ? m + n ? 6, A,B= Li, Na, Al, Cu, Ag, In, Sn, Pb) for species and configurations having a low RITS and large highest occupied Molecular Orbital (MO) to lowest unoccupied MO energy gap (Eg). We found seven bimetallic clusters with Eg > 1.5 eV. PMID:26772561

  6. Comparison of advanced offline and in situ techniques of organic aerosol composition measurement during the CalNex campaign

    Science.gov (United States)

    Timkovsky, J.; Chan, A. W. H.; Dorst, T.; Goldstein, A. H.; Oyama, B.; Holzinger, R.

    2015-12-01

    Our understanding of formation processes, physical properties, and climate/health effects of organic aerosols is still limited in part due to limited knowledge of organic aerosol composition. We present speciated measurements of organic aerosol composition by two methods: in situ thermal-desorption proton-transfer-reaction mass spectrometry (TD-PTR-MS) and offline two-dimensional gas chromatography with a time-of-flight mass spectrometer (GC GC/TOF-MS). Using the GC GC/TOF-MS 153 compounds were identified, 123 of which were matched with 64 ions observed by the TD-PTR-MS. A reasonable overall correlation of 0.67 (r2) was found between the total matched TD-PTR-MS signal (sum of 64 ions) and the total matched GC GC/TOF-MS signal (sum of 123 compounds) for the Los Angeles area. A reasonable quantitative agreement between the two methods was observed for most individual compounds with concentrations which were detected at levels above 2 ng m-3 using the GC GC/TOF-MS. The analysis of monocarboxylic acids standards with TD-PTR-MS showed that alkanoic acids with molecular masses below 290 amu are detected well (recovery fractions above 60 %). However, the concentrations of these acids were consistently higher on quartz filters (quantified offline by GC GC/TOF-MS) than those suggested by in situ TD-PTR-MS measurements, which is consistent with the semivolatile nature of the acids and corresponding positive filter sampling artifacts.

  7. 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)

  8. 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 Gologique 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 Gophysique, 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.

  9. 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.

  10. 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)

  11. In-situ investigation of adsorption of dye and coadsorbates on TiO 2 films using QCM-D, fluorescence and AFM techniques

    KAUST Repository

    Harms, Hauke A.

    2013-09-11

    Simultaneous adsorption of dye molecules and coadsorbates is important for the fabrication of high-efficiency dyesensitized solar cells, but its mechanism is not well understood. Herein, we use a quartz crystal microbalance with dissipation technique (QCM-D) to study dynamically and quantitatively the sensitization of TiO2 in situ. We investigate dye loading for a ruthenium(II) polypyridyl complex (Z907), of a triphenylamine-based D-?-A dye (Y123), and of a ullazine sensitizer (JD21), as well as the simultaneous adsorption of the latter two with the coadsorbate chenodeoxycholic acid. By combining the QCM-D technique with fluorescence measurements, we quantify molar ratios between the dye and coadsorbate. Furthermore, we will present first studies using liquid-phase AFM on the adsorbed dye monolayer, thus obtaining complementary microscopic information that may lead to understanding of the adsorption mechanism on the molecular scale. 2013 SPIE.

  12. Transport critical current of Solenoidal MgB2/Cu Coils Fabricated Using a Wind-Reaction In-situ Technique

    CERN Document Server

    Soltanian, S; Wang, X L; Tomsic, M; Dou, S X

    2003-01-01

    In this letter, we report the results of transport Jc of solenoid coils upto 100 turns fabricated with Cu-sheathed MgB2 wires using a wind-reaction in-situ technique. Despite the low density of single core and some reaction between Mg and Cu-sheath, our results demonstrate the decrease in transport Jc with increasing length of MgB2 wires is insignificant. Solenoid coils with diameter as small as 10 mm can be readily fabricated using a wind-reaction in-situ technique. The Jc of coils is essentially the same as in the form of straight wires. A Jc of 133,000 A/cm2 and 125,000 A/cm2 at 4 K and self field has been achieved for a small coil wound using Cu-sheathed tape and Cu-sheathed wire respectively. These results indicate that the MgB2 wires have a great potential for lage scale applications

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

    DEFF Research Database (Denmark)

    Christiansen, Ane Slland; Johnsen, Rune E.; Norby, Poul; Frandsen, Cathrine; Mrup, Steen; Jensen, Sren Hjgaard; 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 ...

  14. 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

  15. 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 μm 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.

  16. 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)

  17. In situ stabilization/solidification pilot testing of coal tar contaminated sediment focusing on air quality testing program, Sydney, Nova Scotia

    Energy Technology Data Exchange (ETDEWEB)

    Raphael, A. [AECOM, Calgary, AB (Canada); Hilchey, J. [AECOM, Sydney, NS (Canada)

    2010-07-01

    This paper presented the results of a pilot-scale demonstration project conducted to test air quality contaminant emissions at a remediation project in Sydney, Nova Scotia. In situ sediment solidification/stabilization (S/S) was selected as a remedial solutions for sediments in an estuarine pond contaminated with polycyclic aromatic hydrocarbons (PAHs). The aim of the air monitoring program was to determine the emission rates of sediment contaminants that became airborne during remediation activities and to monitor the off-site environmental impacts of the emissions. The pilot project included driving interlocking steel sheet pile (SSP) through the sediment into the underlying natural soils, removing overlying water, homogenizing the sediment, and mixing S/S reagents into the sediment over a period of 4 days at 2 different sites. Air sampling equipment was used to monitor volumetric flow rates, benzene, naphthalene and particulate matter concentrations. Continuous real-time monitoring was used at downwind fence line perimeters and by time-weighted ambient air sampling at 6 community stations near the sites. Results of the study showed that the site-specific benzene and naphthalene emission rates were significantly lower than emission rates calculated using theoretical models. No exceedances of established community air quality limits were observed. 8 refs., 3 tabs., 3 figs.

  18. 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)

  19. 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.

  20. [The AO external clamp fixator. New techniques in external stabilization of tibial fractures].

    Science.gov (United States)

    Haas, N P; Schtz, M; Frigg, R; Sdkamp, N P; Hoffmann, R

    1994-11-01

    A serious disadvantage of conventional external fixators is the opening of the medullary canal. This creates a direct communication between the canal and the exterior. The new pinless external fixator does not have this disadvantage. The clamps of the new fixator system do not penetrate cortical bone, they simply rest on the cortical surface. The clinical indications of this easily managed system are fractures of the tibial shaft in cases in which primary internal fixation is precluded either by precarious local or general conditions, or even by a lack of infrastructure. In such situations the pinless external fixator is an excellent device to achieve a good fracture stabilisation rapidly, while leaving open all subsequent alteration of treatment. In case of secondary change to an intramedullary nail the pinless fixator facilitates the procedure, because this fixator can be also used as an distractor during nailing. Furthermore this fixator can be combined with any intramedullary nail to increase the stability in case of very proximal or distal as well as highly instable shaft fractures. The clamps of the pinless external fixator set are used in combination with the standard AO fixator system. PMID:7821065

  1. 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

  2. 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.

  3. 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; Sato, Yuko [National Inst. of Infectious Diseases, Tokyo (Japan); Yamaguchi, Kazuyoshi; Yanagisawa, Akio; Maeda, Hatsuhiko

    1999-02-01

    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.)

  4. 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.)

  5. 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

  6. 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

  7. 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.

  8. 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

  9. [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

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

    DEFF Research Database (Denmark)

    Horn, Anna Frisenfeldt; Nielsen, Nina Skall; Jensen, Louise Helene Søgaard; Horsewell, Andy; Jacobsen, Charlotte

    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......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...... 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...

  11. 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.

  12. Deproteinization technique stabilizes the adhesion of the fiberglass post relined with resin composite to root canal.

    Science.gov (United States)

    Cecchin, Doglas; Almeida, Jos F A; Gomes, Brenda P F A; Zaia, Alexandre A; Ferraz, Caio C R

    2012-02-01

    To evaluate the effects of pretreatment of root dentin by 5.25% sodium hypochlorite (NaOCl) alone, associated with 2% chlorhexidine in gel base (CHX) and/or ethanol (EtOH), and the air-drying technique (Air) on the bond strength and adhesive durability of fiberglass post relined with resin composite to root dentin. A total of 100 bovine incisor roots were divided into 10 groups: G1 (control), irrigation with physiologic solution; G2, Air; G3, NaOCl; G4, NaOCl + Air; G5, NaOCl + EtOH; G6, NaOCl + EtOH + Air; G7, NaOCl + CHX; G8, NaOCl + CHX + Air; G9, NaOCl + CHX + EtOH; G10, NaOCl + CHX + EtOH + Air. Fiberglass post relined with resin composite was cemented and each group was randomly divided into two subgroups: 24 h of water storage and 12 months of water storage. The push-out test was performed and bond strength values were analyzed by ANOVA and Tukey's test. The use of NaOCl alone or associated with CHX had the highest values of bond strength with or without Air in the immediate and stored groups, being statistically similar to the immediate control group (p > 0.05). The groups using EtOH or Air alone had lower bond strength in the immediate and stored groups (p 0.05). The use of NaOCl or NaOCl associated with CHX preserved the bond strength immediate and for 12 months. The air-drying technique and the other associations decreased the immediate bond strength values. PMID:22102546

  13. 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

  14. 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.

  15. 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.)

  16. 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

  17. 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)

  18. Quantifying in-situ gas hydrates at active seep sites in the eastern Black Sea using pressure coring technique

    Directory of Open Access Journals (Sweden)

    K. U. Heeschen

    2011-12-01

    Full Text Available In the eastern Black Sea, we determined methane (CH4 concentrations, gas hydrate volumes, and their vertical distribution from combined gas and chloride (Cl? measurements within pressurized sediment cores. The total gas volume collected from the cores corresponded to concentrations of 1.21.4 mol CH4 kg?1 porewater at in-situ pressure, which is equivalent to a gas hydrate saturation of 1518% of pore volume and amongst the highest values detected in shallow seep sediments. At the central seep site, a high-resolution Cl? profile resolved the upper boundary of gas hydrate occurrence and a continuous layer of hydrates in a sediment column of 120 cm thickness. Including this information, a more precise gas hydrate saturation of 2224% pore volume could be calculated. This volume was higher in comparison to a saturation calculated from the Cl? profile alone, resulting in only 14.4%. The likely explanation is an active gas hydrate formation from CH4 gas ebullition. The hydrocarbons at Batumi Seep are of shallow biogenic origin (CH4 > 99.6%, at Pechori Mound they originate from deeper thermocatalytic processes as indicated by the lower ratios of C1 to C2C3 and the presence of C5.

  19. Development of in-situ UV-vis technique for the molten salt electrorefining process of uranium

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. H.; Hwang, S. C.; Kang, Y. H.; Shim, J. B.; Ahn, B. G.; Kwon, S. W.; Woo, M. S.; Lee, B. J.; Kim, E. H.; Park, S. W. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2005-07-01

    During the last decade, interest in the pyrometallrugical treatment of spent nuclear fuel has been drastically increased because of its relatively low processing cost as well as its proliferation resistance of the nuclear fuel cycles. Similar but unique researches have been conducted by several institutions in various countries using their own strategies, i.e. IFR fuel cycle in ANL, DOVITA process in RIAR and ,OMEGA program in JAERI. The Korea Atomic Energy Research Institute (KAERI) is developing an electrorefining process using PWR surrogate spent fuels. In this fuel cycle, uranium and TRU oxides are electrochemically reduced while the rare earth oxides are intact. Thus, the prepared ingot consists of metallic uranium, TRU and rare earth oxides. The main scientific and technological interests in the electrorefining process using the electrochemically reduced fuel ingot are how to effectively partition a spent fuel into Uranium, TRU and fission products (FPs). Furthermore a systematic consideration for a series of pyrochemical treatments of the spent fuel which includes not only an electrorefining but also a cathode process has not been reported. Hence in this study, we would like to report on the methodology to recycle PWR fuel for a future use and some important results in the electrorefining of the uranium and the cathode process of the deposit. Also, in-situ UV-vis absorption spectrometry was adopted to observe the behavior of Nd{sub 2}O{sub 3} in molten salt encouraged by the recent results of Yamana et. al.

  20. 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.

  1. Evaluation of the in situ, time-integrated DGT technique by monitoring changes in heavy metal concentrations in estuarine waters

    International Nuclear Information System (INIS)

    Various natural and anthropogenic processes influence heavy metal concentrations within estuaries. In situ, time-integrated DGT measurements made over concurrent tidal phases found significantly higher concentrations of Cu (probability p = 0.017), Zn (p = 0.003) and Ni (p = 0.003) during the flood phase, because the incoming tide passes several point sources. DGT-reactive Cu concentrations significantly decreased with increased tidal-flushing and vice versa within a marina (correlation r = -0.788, p = 0.02). DGT measurements also recorded significant increases in Cu (4 out of 4 sites, p < 0.001) and Zn (3 out of 4 sites, p ? 0.015) after a 24 mm rainfall event. Finally, DGT-reactive Cu increased significantly (p < 0.001) during peak boating times, due to increased numbers of Cu-antifouled boats. This study demonstrates that, with judicious selection of deployment times, DGT measurements enable changes in heavy metal concentrations to be related to various cycles and events within estuaries. - Demonstration of the usefulness of DGT as a monitoring tool for heavy metals in dynamic estuaries

  2. Investigation of surface oxidation of nitride layer on uranium by in-situ XPS and AES technique

    International Nuclear Information System (INIS)

    The initial oxidation behavior of nitride layer (U2N3+x) on uranium metal was investigated by in-situ X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) in oxygen atmosphere at room temperature. AES differential spectrum of uranium and U 4f, N 1s, O 1s spectra all show that UNxOy is formed during the oxidation of nitride layer. When exposing to 18 L and 120 L oxygen it was observed by AES profile measurements that an oxide-nitrogen rich-nitride sandwich structure was formed on the surface of nitride layer. As the OPV mixing peak of nitro gen-rich film is much lower than that of the nitride and oxide layer, and N 1s peak shows the same trend as OPV peak, nitrides with higher N/U ratio may form in the nitrogen-rich layer. It is implied that during the oxidation of uranium sesiquinitride the N atom will be substituted by O atom and move to fill the vacancies of neighbor nitride crystal lattice, which increases the N/U ratio of neighbor field and prevents the O atom's diffusion. (authors)

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. Comparative proteomics evaluation of plasma exosome isolation techniques and assessment of the stability of exosomes in normal human blood plasma.

    Science.gov (United States)

    Kalra, Hina; Adda, Christopher G; Liem, Michael; Ang, Ching-Seng; Mechler, Adam; Simpson, Richard J; Hulett, Mark D; Mathivanan, Suresh

    2013-11-01

    Exosomes are nanovesicles released by a variety of cells and are detected in body fluids including blood. Recent studies have highlighted the critical application of exosomes as personalized targeted drug delivery vehicles and as reservoirs of disease biomarkers. While these research applications have created significant interest and can be translated into practice, the stability of exosomes needs to be assessed and exosome isolation protocols from blood plasma need to be optimized. To optimize methods to isolate exosomes from blood plasma, we performed a comparative evaluation of three exosome isolation techniques (differential centrifugation coupled with ultracentrifugation, epithelial cell adhesion molecule immunoaffinity pull-down, and OptiPrep(TM) density gradient separation) using normal human plasma. Based on MS, Western blotting and microscopy results, we found that the OptiPrep(TM) density gradient method was superior in isolating pure exosomal populations, devoid of highly abundant plasma proteins. In addition, we assessed the stability of exosomes in plasma over 90 days under various storage conditions. Western blotting analysis using the exosomal marker, TSG101, revealed that exosomes are stable for 90 days. Interestingly, in the context of cellular uptake, the isolated exosomes were able to fuse with target cells revealing that they were indeed biologically active. PMID:24115447

  10. A Comparison of the Stability Performance of Blends of Paraffinic Diesel and Petroleum-Derived Diesel, with RME Biodiesel Using Laboratory Stability Measurement Techniques

    OpenAIRE

    de Goede, S.; C. Wilken; M. Ajam; Roets, P.; P. Engelbrecht; Woolard, C.

    2015-01-01

    In 2012, a new specification for synthetic fuels containing up to 7% biodiesel (FAME) was approved (CEN TS 15940). This specification allows the sale of neat paraffinic diesel, such as Gas-to-Liquids (GTL) diesel, to captive fleets in Europe. Several aspects are important in the final end-use application, including the stability of the fuel. The current study evaluated the stability of neat GTL diesel and FAME/paraffinic fuel blends via standard laboratory stability tests commonly used to stu...

  11. 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)

  12. 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.

  13. In Situ Object Counting System (ISOCS) Technique: Cost-Effective Tool for NDA Verification in IAEA Safeguards

    International Nuclear Information System (INIS)

    Uranium materials measurements using the ISOCS technique play an increasing role in IAEA verification activities. This methodology provides high uranium/plutonium sensitivity and a low detection limit together with the capability to measure items with different shapes and sizes. In addition, the numerical absolute efficiency calibration of a germanium detector which is used by the technique does not require any calibration standards or reference materials. ISOCS modelling software allows performing absolute efficiency calibration for items of arbitrary container shape and wall material, matrix chemical composition, material fill-height, uranium or plutonium weight fraction inside the matrix and even nuclear material/matrix non-homogeneous distribution. Furthermore, in a number of cases, some key parameters such as matrix density and U/Pu weight fraction can be determined along with analysis of nuclear 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. Today, the basic tool for uranium and plutonium mass measurement used in Safeguards verification activities is the neutron counting technique which employs neutron coincidence and multiplicity counters. In respect to the neutron counting technique, ISOCS calibrated detectors have relatively low cost. Taking into account its advantages, this methodology becomes a cost-effective solution for nuclear material NDA verification. At present, the Agency uses ISOCS for quantitative analysis in a wide range of applications: - Uranium scrap materials; - Uranium contaminated solid wastes; - Uranium fuel elements; - Some specific verification cases like measurement of Pu-Be neutron sources, quantification of fission products in solid wastes etc. For uranium hold-up measurements, ISOCS the only available methodology for quantitative and isotopic composition analysis of nuclear materials deposited in process equipment. With U.S. support program funding, together with the ISOCS developer Canberra Inc, the IAEA manages a task on development of 'Advanced ISOCS software' to provide new functionality with self-modelling capabilities for absolute detection efficiency calibration (software self-calibration) and simplifies the usage of the technique, reducing the required level of expertise necessary for ISOCS analysis. In the framework of this task, the IAEA is also planning to conduct a pilot training course on the technique for IAEA inspectors. (author)

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

    International Nuclear Information System (INIS)

    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

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. Probe-based confocal laser endomicroscopy (pCLE) - a new imaging technique for in situ localization of spermatozoa.

    Science.gov (United States)

    Trottmann, Matthias; Stepp, Herbert; Sroka, Ronald; Heide, Michael; Liedl, Bernhard; Reese, Sven; Becker, Armin J; Stief, Christian G; Klle, Sabine

    2015-05-01

    In azoospermic patients, spermatozoa are routinely obtained by testicular sperm extraction (TESE). However, success rates of this technique are moderate, because the site of excision of testicular tissue is determined arbitrarily. Therefore the aim of this study was to establish probe-based laser endomicroscopy (pCLE) a noval biomedical imaging technique, which provides the opportunity of non-invasive, real-time visualisation of tissue at histological resolution. Using pCLE we clearly visualized longitudinal and horizontal views of the tubuli seminiferi contorti and localized vital spermatozoa. Obtained images and real-time videos were subsequently compared with confocal laser scanning microscopy (CLSM) of spermatozoa and tissues, respectively. Comparative visualization of single native Confocal laser scanning microscopy (CLSM, left) and probe-based laser endomicroscopy (pCLE, right) using Pro Flex(TM) UltraMini O after staining with acriflavine. PMID:24995398

  1. 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.

  2. Technique for in situ calibration of an x-ray streak camera in the nanosecond regime using a high density Z-pinch

    International Nuclear Information System (INIS)

    A technique for calibrating an x-ray streak camera in situ has been developed. It has been applied to an x-ray streak camera installed on a collapsing gas shell Z-pinch. The calibration was done by simultaneously measuring the emitted x-rays using a pinhole camera, an InP:Fe photoconductive detector, and the streak camera. The spatial dimension of the streak image was calibrated by integrating the film density over time and fitting the resulting data to the corresponding information taken from an x-ray pinhole image. The temporal calibration was obtained by similarly fitting the film density from the x-ray streak image as a function of time integrated over the appropriate part of the spatial dimension with the signal from an InP:Fe photoconductive detector. By using this technique we have found a spatial magnification of the streak camera system consistent with the results derived from the geometrical optics to within 10%. A temporal dispersion of 2.5 +- 0.5 ns/mm was obtained, which is in agreement with the nominal speed of 2.5 ns/mm. This technique also yielded an absolute intensity calibration of the streak camera

  3. Fabrication of mullite-bonded porous SiC ceramics from multilayer-coated SiC particles through sol-gel and in-situ polymerization techniques

    Science.gov (United States)

    Ebrahimpour, Omid

    In this work, mullite-bonded porous silicon carbide (SiC) ceramics were prepared via a reaction bonding technique with the assistance of a sol-gel technique or in-situ polymerization as well as a combination of these techniques. In a typical procedure, SiC particles were first coated by alumina using calcined powder and alumina sol via a sol-gel technique followed by drying and passing through a screen. Subsequently, they were coated with the desired amount of polyethylene via an in-situ polymerization technique in a slurry phase reactor using a Ziegler-Natta catalyst. Afterward, the coated powders were dried again and passed through a screen before being pressed into a rectangular mold to make a green body. During the heating process, the polyethylene was burnt out to form pores at a temperature of about 500°C. Increasing the temperature above 800°C led to the partial oxidation of SiC particles to silica. At higher temperatures (above 1400°C) derived silica reacted with alumina to form mullite, which bonds SiC particles together. The porous SiC specimens were characterized with various techniques. The first part of the project was devoted to investigating the oxidation of SiC particles using a Thermogravimetric analysis (TGA) apparatus. The effects of particle size (micro and nano) and oxidation temperature (910°C--1010°C) as well as the initial mass of SiC particles in TGA on the oxidation behaviour of SiC powders were evaluated. To illustrate the oxidation rate of SiC in the packed bed state, a new kinetic model, which takes into account all of the diffusion steps (bulk, inter and intra particle diffusion) and surface oxidation rate, was proposed. Furthermore, the oxidation of SiC particles was analyzed by the X-ray Diffraction (XRD) technique. The effect of different alumina sources (calcined Al2O 3, alumina sol or a combination of the two) on the mechanical, physical, and crystalline structure of mullite-bonded porous SiC ceramics was studied in the second part of the project. Alumina sol was synthesized by the hydrolysis of Aluminum isopropoxide using the Yoldas method. Alumina sol was homogenous and had a needle-like shape with a thickness of 2--3 nm. Crystalline changes during the heating process of alumina sol were studied using XRD. In addition, Fourier transform infrared (FTIR) spectroscopy was performed to identify the functional groups on the alumina sol surface as a function of temperature. In the third part of the project, the feasibility of the in-situ polymerization technique was investigated to fabricate porous SiC ceramics. In this part, the mixture of SiC and calcined alumina powders were coated by polyethylene via in-situ polymerizing referred to as the polymerization compounding process in a slurry phase. The polymerization was conducted under very moderate operational conditions using the Ziegler-Natta catalyst system. Differential scanning calorimetry (DSC) and TGA analysis and morphological studies (SEM and TEM) revealed the presence of a high density of polyethylene on the surface of SiC and alumina powders. The amount of polymer was controlled by the polymerization reaction time. Most parts of particles were coated by a thin layer of polyethylene and polymer. The porous SiC ceramics, which were fabricated by these treated particles showed higher mechanical and physical properties compared to the samples made without any treatment. The relative intensity of mullite was higher compared to the samples prepared by the traditional process. The effects of the sintering temperature, forming pressure and polymer content were also studied on the physical and mechanical properties of the final product. In the last phase of this research work, the focus of the investigation was to take advantage of both the sol-gel processing and in-situ polymerization method to develop a new process to manufacture mullite-bonded porous SiC ceramic with enhanced mechanical and physical properties. Therefore, first the SiC particles and alumina nano powders were mixed in alumina sol to adjust the alumina weight to 35 wt%. Then, the desired amount of catalyst, which depends on the total surface area of the particles, was grafted onto the surface of the powders under an inert atmosphere. Consequently, the polymerization started from the surface of the substrate. The treated powders were characterized by SEM, XPS and TGA. In addition, the amount of pore-former was determined by TGA analysis. Porous SiC ceramics, which were fabricated by the novel process, consist of mullite, SiC, cristobalite and a small amount of alumina and TiO 2 as a result of reaction of TiCl4 with air. Furthermore, the effect of the sintering temperatures (1500°C, 1550°C and 1600°C) on the crystalline structure of the porous samples was investigated. Furthermore, it was proposed that converting TiCl4 to TiO2 acted as the sintering additive to form mullite at a lower sintering temperature. (Abstract shortened by UMI.).

  4. 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.

  5. 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 110 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...

  6. 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)

  7. 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)

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. Sensitivity analysis of standard toxicity tests, rapid bioassays and in-situ techniques to indicate effluent toxicity in Gulf of Mexico estuaries

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, M.; Weber, D. [Environmental Protection Agency, Gulf Breeze, FL (United States)

    1995-12-31

    The toxicities of eight industrial and municipal effluents discharged into the Pensacola Bay System (Florida) were evaluated for two years. Standard chronic toxicity tests with algae, invertebrates and fish were determined, as were effects monitored by Mutatox{reg_sign} and Microtox{reg_sign}. Sediment toxicity in the receiving water to four test species, in-situ effects on colonized periphyton and oyster tissue analysis were determined to assess environmental relevance of single-species toxicity tests. Overall, chronic toxicity to fish and Microtox effects were rarely observed; whereas, Mutatox effects and chronic toxicity to invertebrates were more common. Phytotoxicity (inhibition) of the effluents and sediment in the receiving water was not usually observed; however, significant stimulation of plant growth was common. Biomass and chlorophyll content of periphyton in the receiving water were greater than those in control areas, reflecting the stimulatory effect on growth observed in the laboratory phytotoxicity tests. Overall, toxicity was observed for all effluents by at least one diagnostic technique. There was no most sensitive test since effects were effluent-specific. Consequently, since there was no single effective test, the scientific and regulatory communities need to decide the significance of the various effluent assessment techniques and the ramifications of this issue on the NPDES permitting process.

  15. 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.

  16. Controllable synthesis and characterization of porous polyvinyl alcohol/hydroxyapatite nanocomposite scaffolds via an in situ colloidal technique.

    Science.gov (United States)

    Poursamar, S Ali; Azami, Mahmoud; Mozafari, Masoud

    2011-06-01

    During the last decades, there have been several attempts to combine bioactive materials with biocompatible and biodegradable polymers to create nanocomposite scaffolds with excellent biocompatibility, bioactivity, biodegradability and mechanical properties. In this research, the nanocomposite scaffolds with compositions based on PVA and HAp nanoparticles were successfully prepared using colloidal HAp nanoparticles combined with freeze-drying technique for tissue engineering applications. In addition, the effect of the pH value of the reactive solution and different percentages of PVA and HAp on the synthesis of PVA/HAp nanocomposites were investigated. The SEM observations revealed that the prepared scaffolds were porous with three dimensional microstructures, and in vitro experiments with osteoblast cells indicated an appropriate penetration of the cells into the scaffold's pores, and also the continuous increase in cell aggregation on the scaffolds with increase in the incubation time demonstrated the ability of the scaffolds to support cell growth. According to the obtained results, the nanocomposite scaffolds could be considered as highly bioactive and potential bone tissue engineering implants. PMID:21310596

  17. 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)

  18. 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

  19. Experimental study for determining the corrosion in situ of SS-304 in heat transformers applying electrochemical techniques

    International Nuclear Information System (INIS)

    In this work the corrosion performance of SS-304 experimentally tested in a single stage absorption heat transformer (SSAHT) operating with lithium-bromide aqueous solution and water as the absorbent and work fluids coupled to a desalinizer is reported. The main aim of this work was to determine the corrosion rate and corrosion mechanism of SS-304 through some electrochemical cells designed for this specific purpose and connected in one of the pipe constituting the heat transformer. Some electrochemical techniques named electrochemical noise (EN), and electrochemical impedance spectroscopy (EIS) were applied under the next experimental conditions: temperature 83-85 C, concentration of LiBr-H2O corrosive solution 56 (wt.%), and flow rate 0.0278 m3/s. According to the physical characterization, SS-304 suffered a mixed corrosion process, which is in concordance with the signal noise pattern obtained. Through the Nyquist plots from EIS the corrosion process was obtained as controlled by charge transfer at the first 3:25 h, and then a diffusion effect was observed. (authors)

  20. 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.

  1. 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% (frao de massa) de nano-SiO2 foi preparado. Posteriormente, o MA reativo preparado foi usado como carga no preparo de nanocompsitos PA6/SiO2 (RA). A estrutura do RA foi analisada por espectrometria no infravermelho por transformad [...] a de Fourier (FTIR), microscopia eletrnica de transmisso (TEM), difratometria de raios X (XRD), microscopia eletrnica de varredura (SEM) e microscopia ptica de luz polarizada (POM). A estabilidade trmica e o comportamento de cristalizao do RA foram avaliados por anlise termogravimtrica (TGA) e calorimetria exploratria diferencial (DSC). OS resultados indicaram que as cadeias moleculares de PA6 estavam ancoradas na superfcie do nano-SiO2 atravs de ligaes qumicas entre a superfcie de grupos amino do nano-SiO2 e do monmero da ?-caprolactama ou pr-polmero da PA6. Como resultado, uma camada interfacial flexvel foi formada, melhorando a compatibilidade do nano-SiO2 com a matriz de PA6. Alm disso, o efeito no nano-SiO2 apresentou melhoras nas propriedades mecnicas do RA. Devido ao efeito de impedimento de movimento das cadeias moleculares da PA6 pelas partculas de nano-SiO2, o tamanho da esfera cristalina de PA6 foi menor e sua forma cristalina tambm foi afetada. A massa molar da matriz de PA6 tende a decair gradualmente com o aumento do contedo 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.

  2. 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.

  3. Tcnica 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 tcnica para o estudo da estabilidade de agregados do solo. Vrios tipos de solo sob diferentes condies de uso foram estudados. Amostras em triplicato, de 25 g de agregados entre 7 e 4 mm, foram agitados em agitador modlo Wagner, com 40 r.p.m., durante 1, [...] 2, 4, 8, 16, 32, 64 e 128 minutos e depois fracionadas pelo mtodo da peneiragem lenta em gua. Os agregados > 2 mm diminuram em pso com o aumento do tempo de agitao, 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 So 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

  4. 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 SeptemberOctober 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 45%. 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 23%. 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.

  5. Clasificacin molecular del cncer de mama, obtenida a travs de la tcnica de hibridacin in situ cromognica (CISH) / Molecular classification of breast cancer patients obtained through the technique of chromogenic in situ hybridization (CISH)

    Scientific Electronic Library Online (English)

    ngel, Fernndez; Aldo, Reigosa.

    2013-12-01

    Full Text Available El cncer de mama es una enfermedad heterognea compuesta de un nmero creciente de subtipos biolgicos, con una sustancial variabilidad en la evolucin de la enfermedad dentro de cada categora. 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 amplificacin de HER2 obtenido a travs de la tcnica de hibridacin in situ cromognica (CISH). La muestra estuvo constituida por 200 biopsias fijadas en formol al 10%, procesadas por las tcnicas habituales hasta la inclusin en parafina, correspondientes a pacientes diagnosticadas con carcinoma ductal infiltrante de la mama, procedentes de consulta privada y del Instituto de Oncologa Dr. Miguel Prez Carreo, con estudio inmunohistoqumico (IHQ) para receptores hormonales y HER2 realizado en el Hospital Metropolitano del Norte de Valencia, Venezuela. La clasificacin molecular de los tumores de las pacientes, considerando la expresin de los Receptores de Estrgeno (RE) y Receptores de Progesterona (RP) a travs de IHQ y la amplificacin de HER2 por CISH, permiti agrupar en las diferentes clases moleculares los casos calificados inicialmente como desconocidos, debido a que tenan un resultado indeterminado (2+) para la expresin de HER2 por IHQ; asimismo, esta clasificacin ocasion que algunos casos considerados inicialmente en una clase molecular pasaron a otra clase, posterior a la revaloracin del estado de HER2 a travs 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 Prez Carreo", for immunohistochemistry (IHC) of hormone receptors and HER2 made in the Hospital Metropolitano del Norte, Valencia, Venezuela. The molecular classification of the patients 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.

  6. 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

  7. In-situ investigation of stress conditions during expansion of bare metal stents and PLLA-coated stents using the XRD sin(2)ψ-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)ψ-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

  8. Structural change of Ni-Cu alloy nanowires with temperature studied by in situ X-ray absorption fine structure technique

    Energy Technology Data Exchange (ETDEWEB)

    Mo Guang; Cheng Weidong; Cai Quan; Wang Wei; Zhang Kunhao; Xing Xueqing [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China); Chen Zhongjun [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Wu Zhonghua, E-mail: wuzh@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2010-05-15

    Ni-Cu alloy nanowire array, with uniform length and diameter, was well fabricated by using alternating current electrodeposition. Both X-ray diffraction and in situ heating extended X-ray absorption fine structure technique were employed to characterize its structural change with temperature. As expected, a weak concentration fluctuation of Ni and Cu atoms was found in the as-prepared nanowires. However, this concentration fluctuation can be easily eliminated by heating the as-prepared sample at 200 deg. C, which resulting in an approximately homogeneous Ni-Cu solid solution. From the nanostructural point of view, the serviceability temperature of Ni-Cu alloy nanowire array in magnetism could not exceed 200 deg. C. The Ni-Ni, Ni-Cu and Cu-Cu bonds were found to have different thermal expansion behaviors, causing the distortion of the crystal cell. An average thermal expansion coefficient (1.1 x 10{sup -5} K{sup -1}) was obtained. The structural change of Ni-Cu alloy nanowires with temperature was discussed.

  9. 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.

  10. In situ Raman spectroscopy and confocal microscopy of 2.5-billion-year-old fossil microorganisms: viable nondestructive techniques for the study of returned Martian samples

    Science.gov (United States)

    Czaja, A. D.; Lorber, K.

    2014-12-01

    This study presents the discovery of two sets of Archean fossil microorganisms (microfossils) and describes how such a study can be an analogue for a potential Martian sample return mission like that proposed as a follow up to the Mars 2020 mission. Microfossils are not easily preserved and their simple morphologies (made less distinct by taphonomy and diagenesis) can be confused with nonbiological structures. Thus, several lines of evidence are required for a biological interpretation of such remains. Despite this limitation, microfossils represent the most direct and easily illustrated evidence of life, and this will also be true of any microfossils that might be found on Mars. Martian sample return will provide the first chance to apply a full suite of analytical techniques to the study of possible Martian microfossils. Because such precious samples would be of limited quantity, this suite must include nondestructive techniques that are performed in situ and at a micron-scale.The samples studied here were collected from two chert units within the Gamohaan Formation of the Kaapvaal Craton of South Africa. One set was collected from the Tsineng Member near the top of the formation and contains fossils of mat-forming filamentous microorganisms (~15-20 m in diameter) that were buried in place. The other set comes from a chert bed stratigraphically lower within the Gamohaan Formation. This bed contains shriveled and somewhat compacted spherical microfossils (~100 m in diameter) and are interpreted to be the remains of planktonic forms that settled from above. Cherts were collected based on a visual identification of their likelihood to contain microfossils. Optical microscopy was used to locate microstructures of interest within thin sections. The biological nature of these structures is supported by analyses of their three dimensional morphologies by confocal laser scanning microscopy (CLSM) as well as their carbonaceous compositions by Raman spectroscopy. Raman and CLSM are nondestructive techniques that can be used to analyze specimens within rock to the depth of several tens of microns with no special sample preparation. Also, because Raman and CLSM can be used to study modern microorganisms, they are ideal techniques for the study of returned Martian samples that could contain either fossil or living material.

  11. Dimensional Stability of Polyether, Alginate, and Silicone Impression Materials After Disinfection With 2% Sanosil Through the Immersion Technique

    OpenAIRE

    Izadi; Badamchizadeh; Mojaver Kahnamouyi; Marefat

    2014-01-01

    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 mater...

  12. 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

  13. In situ generated silica in natural rubber latex via the solgel 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 solgel 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. Solgel method is an alternative way to develop a novel composite material

  14. Applicability study of using in-situ gamma-ray spectrometry technique for 137Cs and 210Pbex inventories measurement in grassland environments

    International Nuclear Information System (INIS)

    In-situ measurement of fallout radionuclides 137Cs and 210Pbex has the potential to assess soil erosion and sedimentation rapidly. In this study, inventories of 137Cs and 210Pbex in the soil of Inner Mongolia grassland were measured using an In-situ Object Counting System (ISOCS). The results from the field study indicate that in-situ gamma-ray spectrometry has the following advantages over traditional laboratory measurements: no extra time is required for sample collection, no reference inventories are required, more economic, prompt availability of the results, the ability to average radionuclide inventory over a large area, and high precision.

  15. 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.

  16. 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...

  17. 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...

  18. 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.

  19. 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.

  20. 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...