WorldWideScience
1

Thermal stability investigation of organo-acid-activated clays by TG-MS and in situ XRD techniques  

International Nuclear Information System (INIS)

Organo-acid-activated clays were prepared with different surfactant contents by reaction of hexadecyltrimethylammonium hydroxide solution and acid-activated clays. The intercalated cations adopted different orientation in the interlayer spacing of the acid-activated clays and their thermal stability depended on the up taken amounts, acidity of the clay sheets and on the heating temperatures. The thermal stability of these materials was investigated using TG-MS, and followed by the in situ X-ray diffraction in nitrogen atmosphere. The clay sheets affected the decomposition of the surfactants, and as per consequence the thermal stability of the surfactants. TG-MS revealed that different types of water molecules were detected during the heating process with additional CO2, alkanes and alkenes species at temperatures above 200 deg. C. The interlayer spacing collapsed after completed degradation of the intercalated surfactants

2

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

3

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.

4

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

5

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

Energy Technology Data Exchange (ETDEWEB)

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.

Allan, M.L.

1996-06-01

6

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.)

7

Efficient technique for measuring laser frequency stability  

OpenAIRE

We propose a new technique for measuring the frequency stability of cw laser radiation. The technique relies on using the laser to be tested as a coupling laser in a scheme of electromagnetically-induced transparency (EIT), either on a ? or a ladder system. A second, frequency tunable laser (stabilization of this laser is not needed) is used both to act as the EIT probe laser, and to form an atomic frequency reference spectrum. The frequency stability is monitored via the frequency deviation...

Sargsyan, A.; Papoyan, A. V.; Sarkisyan, D.; Weis, Antoine

2009-01-01

8

In situ uranium stabilization by microbial metabolites  

Energy Technology Data Exchange (ETDEWEB)

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.

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

9

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

10

IN SITU URANIUM STABILIZATION BY MICROBIAL METABOLITES  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2006-11-29

11

In-situ thermoelectric stabilization of radioactive wastes  

International Nuclear Information System (INIS)

A new process for stabilizing buried radioactive wastes without exhumation is being developed by Pacific Northwest Laboratory (PNL). The process, known as in situ vitrification, converts waste and contaminated soil to a durable glass and crystalline material by passing an electric current between electrodes placed in the ground. Joule heating created by the flowing current has generated temperatures over 17000C which cause the soil to melt and dissolve or encapsulate the wastes. Engineering-scale tests conducted in the laboratory have melted approximately 45 kgs (30 liters) of soil at a time by this technique. Encouraging results from these engineering-scale tests led to the design and construction of a pilot-scale field test unit which has solidified approximately 9000 kg of simulated contaminated soil per test. Test results and evaluations to date have been very promising. No detectable migration of hazardous species into uncontaminated soil has been found, and volatilization during melting has been very low. Leach studies have found the vitrified soil to be a highly durable waste form similar to pyrex glass. Electrical power costs to solidify a disposal site have been calculated at less than $70 per cubic meter ($2/ft3) of waste. Future activities include both radioactive and nonradioactive pilot and large-scale tests

12

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

Energy Technology Data Exchange (ETDEWEB)

Polymer-stabilized paramagnetic and fluorescent rare-earth metal sulfide (cerium sulfide, Ce{sub 2}S{sub 3}) 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 Ce{sup 3+} ionic species at the reaction condition. (orig.)

Mallick, Kaushik [University of Johannesburg, Department of Chemistry, P.O. Box 524, Auckland Park (South Africa); Witcomb, Michael [University of the Witwatersrand, DST/NRF Centre of Excellence in Strong Materials, WITS (South Africa); Strydom, Andre [University of Johannesburg, Department of Physics, P.O. Box 524, Auckland Park (South Africa)

2012-11-15

13

Stabilization of contaminated soils by in situ vitrification  

International Nuclear Information System (INIS)

In situ methods are preferred for the stabilization or restoration of soil sites contaminated with elevated levels of hazardous materials (e.g., radionuclides, metals, organics) to minimize potential risks to personnel and the environment associated with removal and treatment. In situ methods available include polymer and silicate grouting, compaction, chemical treatment, groundwater diversion, and vitrification. Of these, in situ vitrification (ISV) is most desirable because it is more a permanent solution and produces a final waste form with the most preferred characteristics. The ISV product, generally a mixture of glass and crystals, has high strength, is resistant to leaching, and has low porosity and permeability. Results are presented on an ISV test at an Oak Ridge Laboratory Site

14

EMERGING EX-SITU BIOREMEDIATION TECHNIQUES FOR MTBE  

Science.gov (United States)

The presentation will summarize data from the latest techniques that are being studied for ex-situ treatment of MTBE-contaminated groundwater. Most of the presentation will focus on bioremediation technologies. Researchers' work that will be summarized include that of Chang et al...

15

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

16

Stability robustness improvement using constrained optimization techniques  

Science.gov (United States)

In a multiloop feedback control system, stability margin improvement by singular value shaping can be achieved by a noise adjustment procedure. A direct method for shaping singular value spectrum using constrained optimization technique is described. The design algorithm minimizes a standard LQG performance index while trying to satisfy minimum singular value constraints at the plant input, or output, or at both. Selected parameters of a stabilizing control law are used as the design variables. The capabilities of this method are demonstrated using a two input two output system representing a drone aircraft and its lateral attitude control system.

Mukhopadhyay, V.

1985-01-01

17

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

18

In situ and ex situ characterization of optical surfaces by light scattering techniques  

Science.gov (United States)

The continuous development of optical technologies and the accompanying requirements on the manufacturing process place challenging demands on metrology. In addition to highly sensitive and robust measurement techniques, the inspection tools should be fast and capable of characterizing large and complex-shaped surfaces. These aspects can be addressed by light-scattering-based characterization techniques, which also enable a large flexibility for the measurement conditions because of the noncontact data acquisition and are, thus, suited not only for ex situ but also in situ characterization scenarios. Application examples ranging from the roughness characterization of magneto-rheological finished substrates to polished extreme ultraviolet mirror substrates with diameters of more than 600 mm by compact as well as laboratory-based instruments are presented.

Trost, Marcus; Herffurth, Tobias; Schröder, Sven; Duparré, Angela; Beier, Matthias; Risse, Stefan; Tünnermann, Andreas; Böwering, Norbert

2014-09-01

19

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

Science.gov (United States)

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

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

2014-10-28

20

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2014-09-24

21

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 adsorpt 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

22

In Situ Techniques for Life Detection on Mars  

Science.gov (United States)

The search for organic matter on Mars is rapidly emerging as a result of technological advancements and the study of early "life" on our own planet. As we learned from the Viking missions and the examination of martian meteorites, the criteria for establishing life require the appropriate strategy. One such approach would require careful mapping of the surface from orbit for the selection of the appropriate landing sites, robotic space missions equipped with several life detection in situ techniques for selection of samples, and sample return missions for additional verification of in situ results and laboratory measurements. It may, however, be possible to obtain critical information about the organic matter and associated mineral assemblages present on Mars, in situ, in a single measurement that is both capable of flight and is nondestructive to the sample. We discuss a new multi-source mass spectrometer, `MOMA' (Mars Organic Molecule Analyzer) that incorporates multiple methods of volatilizing and ionizing chemical compounds from intact samples without further processing or manipulation. Moreover, MOMA is capable of detecting a broad range of organics enabling the evaluation of the origin of the organics and the presence of terrestrial contaminants.

Becker, L.; Brinckerhoff, W.; Cotter, R.

2006-12-01

23

Experimental Investigation of Centrifugal Compressor Stabilization Techniques  

Science.gov (United States)

Results from a series of experiments to investigate techniques for extending the stable flow range of a centrifugal compressor are reported. The research was conducted in a high-speed centrifugal compressor at the NASA Glenn Research Center. The stabilizing effect of steadily flowing air-streams injected into the vaneless region of a vane-island diffuser through the shroud surface is described. Parametric variations of injection angle, injection flow rate, number of injectors, injector spacing, and injection versus bleed were investigated for a range of impeller speeds and tip clearances. Both the compressor discharge and an external source were used for the injection air supply. The stabilizing effect of flow obstructions created by tubes that were inserted into the diffuser vaneless space through the shroud was also investigated. Tube immersion into the vaneless space was varied in the flow obstruction experiments. Results from testing done at impeller design speed and tip clearance are presented. Surge margin improved by 1.7 points using injection air that was supplied from within the compressor. Externally supplied injection air was used to return the compressor to stable operation after being throttled into surge. The tubes, which were capped to prevent mass flux, provided 9.3 points of additional surge margin over the baseline surge margin of 11.7 points.

Skoch, Gary J.

2003-01-01

24

An in Situ Technique for Elemental Analysis of Lunar Surfaces  

Science.gov (United States)

An in situ analytical technique that can remotely determine the elemental constituents of solids has been demonstrated. Laser-Induced Breakdown Spectroscopy (LIBS) is a form of atomic emission spectroscopy in which a powerful laser pulse is focused on a solid to generate a laser spark, or microplasma. Material in the plasma is vaporized, and the resulting atoms are excited to emit light. The light is spectrally resolved to identify the emitting species. LIBS is a simple technique that can be automated for inclusion aboard a remotely operated vehicle. Since only optical access to a sample is required, areas inaccessible to a rover can be analyzed remotely. A single laser spark both vaporizes and excites the sample so that near real-time analysis (a few minutes) is possible. This technique provides simultaneous multielement detection and has good sensitivity for many elements. LIBS also eliminates the need for sample retrieval and preparation preventing possible sample contamination. These qualities make the LIBS technique uniquely suited for use in the lunar environment.

Kane, K. Y.; Cremers, D. A.

1992-01-01

25

On the resolvent technique for stability of plane Couette flow  

OpenAIRE

We discuss the application of the resolvent technique to prove stability of plane Couette flow. Using this technique, we derive a threshold amplitude for perturbations that can lead to turbulence in terms of the Reynolds number. Our main objective is to show exactly how much control one should have over the perturbation to assure stability via this technique.

Silva, Pablo Braz E.

2002-01-01

26

Thermal stability of functionalized carbon nanotubes studied by in-situ transmission electron microscopy  

OpenAIRE

The thermal stability of funtionalized carbon nanotubes (CNTs) has been studied experimentally by direct in-situ observations using a heating stage in a transmission electron microscope, from room temperature (RT) to about 1000 °C. It was found that the thermal stability of the functionalized CNTs was significantly reduced during the in-situ heating process. Their average diameter dramatically expanded from RT to about 500 °C, and then tended to be stable until about 1000 °C. The X-ray ene...

Luo, Zhiping; Oki, Aderemi; Carson, Laura; Adams, Luqman; Neelgund, Gururaj; Soboyejo, Nathaniel; Regisford, Gloria; Stewart, Melisa; Hibbert, Kemar; Beharie, Gavannie; Kelly-brown, Cordella; Traisawatwong, Pasakorn

2011-01-01

27

[Unilateral triangular lumbopelvic stabilization: indications and techniques].  

Science.gov (United States)

Operative fixation has become treatment of choice for unstable sacral fractures. Osteosynthesis for these fractures results in loss of reduction in up to 15%. Vertical sacral fractures involving the S1 facet joint (Isler 2 and 3) may lead to multidirectional instability. Multidirectional instability of the posterior pelvic ring and lumbopelvic junction may be stabilized and forces balanced by a so-called lumbopelvic triangular fixation. Lumbopelvic triangular fixation combines vertical fixation between the lumbar vertebral pedicle and the ilium, with horizontal fixation, as an iliosacral screw or a transiliacal plate osteosynthesis. The iliac screw is directed from the posterior superior iliac spine (PSIS) to the anterior inferior iliac spine (AIIS). Thereby, lumbopelvic fixation decreases the load to the sacrum and SI joint and transfers axial loads from the lumbar spine directly onto the ilium. Triangular lumbopelvic fixation allows early full weight bearing and therefore reduces prolonged immobilization. The placement of iliac screws may be a complex surgical procedure. Thus, the technique requires thorough surgical preparation and operative logistics. Wound-related complications may occur. Preexisting Morell-Lavalée lesions increase the risk for infection. Prominent implants cause local irritation and pain. Hardware prominence and pain are markedly reduced with screw head recession into the PSIS. PMID:24233083

Hoffmann, M F; Dudda, M; Schildhauer, T A

2013-11-01

28

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

29

In-situ observations of oxidation and phase stability in cast nickel-based intermetallic alloys  

Energy Technology Data Exchange (ETDEWEB)

The effects of the as-cast microstructure on the oxidation characteristics of two Ni-Al-Cr alloys with either gamma or gamma' primary solidification were investigated with an in-situ, time-resolved X-ray diffraction (TRXRD) technique using synchrotron radiation. The measurements, carried out during rapid heating and cooling, showed that a segregated microstructure in these cast alloys leads to the preferential formation of zirconium oxide before the formation of aluminum oxides is detected. The oxidation leads to a change in the phase stability and to the modification of surface microstructures. Computational thermodynamic models were used to explain the preferential formation of oxides in the as-cast microstructure.

Babu, Suresh S. [Edison Welding Institute; Specht, Eliot D [ORNL; Santella, Michael L [ORNL; Ice, Gene E [ORNL; David, Stan A [ORNL

2006-01-01

30

[Ureteral calculi. In situ ESWL treatment with booster technique].  

Science.gov (United States)

After treatment of more than 3000 kidney and ureteral stones with the Siemens Lithostar Multiline the results of the first 1400 ureteral stone treatments using the "Booster technique" and 3-month follow-up findings are reported. There was a disintegration rate of 98% directly after treatment; 1 week after "Booster technique" treatment 96% of the patients were free of stones and without any symptoms. The 3-month follow-up showed a stone-free rate of 97%. Only in 13% of the cases auxiliary procedures were necessary, 7% of them before extracorporeal shock wave lithotripsy (ESWL) and 6% after ESWL. 43% of the treatments were performed without any premedication, anaesthesia or sedoanalgesia. Our data even prove that in situ ESWL is a safe and effective method for the treatment of ureteral stones. In comparison to endoscopic procedures, it is superior in regard to invasivity, side effects, complications and necessity of analgesia, while being just as efficient. Therefore it is recommended as first choice method in the treatment of ureteral stones. PMID:9265339

Thüroff, S; Chaussy, C

1997-05-01

31

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

Science.gov (United States)

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).

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

2013-01-01

32

Groebner techniques for low degree Hilbert stability  

OpenAIRE

We give a method for verifying, by a symbolic calculation, the stability or semistability with respect to a linearization of fixed, possibly small, degree $m$, of the Hilbert point of a scheme $X \\in {\\mathbb P}(V)$ having a suitably large automorphism group. We also implement our method and apply it to analyze the stability of bicanonical models of certain curves. Our examples are very special, but they arise naturally in the log minimal model program for $\\bar{\\mathcal M}_...

Morrison, Ian; Swinarski, David

2009-01-01

33

In situ synchrotron based x-ray techniques as monitoring tools for atomic layer deposition  

Energy Technology Data Exchange (ETDEWEB)

Atomic layer deposition (ALD) is a thin film deposition technique that has been studied with a variety of in situ techniques. By exploiting the high photon flux and energy tunability of synchrotron based x-rays, a variety of new in situ techniques become available. X-ray reflectivity, grazing incidence small angle x-ray scattering, x-ray diffraction, x-ray fluorescence, x-ray absorption spectroscopy, and x-ray photoelectron spectroscopy are reviewed as possible in situ techniques during ALD. All these techniques are especially sensitive to changes on the (sub-)nanometer scale, allowing a unique insight into different aspects of the ALD growth mechanisms.

Devloo-Casier, Kilian, E-mail: Kilian.DevlooCasier@Ugent.be; Detavernier, Christophe; Dendooven, Jolien [Department of Solid State Sciences, Ghent University, Krijgslaan 281/S1, B-9000 Ghent (Belgium); Ludwig, Karl F. [Physics Department, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215 (United States)

2014-01-15

34

In situ synchrotron based x-ray techniques as monitoring tools for atomic layer deposition  

International Nuclear Information System (INIS)

Atomic layer deposition (ALD) is a thin film deposition technique that has been studied with a variety of in situ techniques. By exploiting the high photon flux and energy tunability of synchrotron based x-rays, a variety of new in situ techniques become available. X-ray reflectivity, grazing incidence small angle x-ray scattering, x-ray diffraction, x-ray fluorescence, x-ray absorption spectroscopy, and x-ray photoelectron spectroscopy are reviewed as possible in situ techniques during ALD. All these techniques are especially sensitive to changes on the (sub-)nanometer scale, allowing a unique insight into different aspects of the ALD growth mechanisms

35

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

36

In-situ stabilization of a low-level radioactive site: a case history  

International Nuclear Information System (INIS)

This paper is based on a feasibility study conducted by Roy F. Weston, Inc., for Sandia National Laboratory for the US Department of Energy's UMTRAP Project Office in Albuquerque, New Mexico. The US DOE 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

37

Experimental techniques for mass measurement far from stability  

Energy Technology Data Exchange (ETDEWEB)

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)

Orr, N

2001-01-01

38

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)

39

Stability comparison between two optical refractometer techniques  

International Nuclear Information System (INIS)

Two optical fibre refractometers are presented; both measure the change in refractive index of an external medium via measurement of the reflectivity of an optical fibre tip. One application of this technology lies in detection of hydrogen using palladium coatings. The first refractometer uses a single source with a probe and reference arm on separate optical fibres, while the second is a dual-wavelength system with a common path for probe and reference beam. We have characterised both systems to compare their sensitivity and long term stability to determine the most suitable configuration in terms of minimising drift and noise.

40

Power system stabilizers based on modern control techniques  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1994-12-31

41

Technique for stabilization of detected x-radiation flux  

International Nuclear Information System (INIS)

A method for stabilization of recorded X-radiation flux is proposed. Stabilization is attained due to the fact that different signs of changes in comparable counting rates cause changes in the position of the detected radiation flux peak. Use of the proposed method of stabilizing X-radiation has the following advantages: it obviates limitations connected with sealing and thermostatting detectors; enlarges the number of problems which can be solved with the help of X-ray radiometric equipment; increases the lifetime of radioisotope sources. The given stabilization technique may be used in radioisotope instruments when measuring the density, coating thicknesses and dust content

42

Technology Demonstration Summary: International Waste Technologies In Situ Stabilization/Solidification, Hialeah, Florida  

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. The analysis...

43

IN-SITU STABILIZATION/SOLIDIFICATION OF PCB-CONTAMINATED SOIL  

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 onsite treatment method for waste site cleanup. emonstration ...

44

Superfund Innovative Technology Evaluation - Demonstration Bulletin: In-Situ Soil Stabilization  

Science.gov (United States)

In-situ stabilization technology immobilizes organics and inorganic compounds in wet or dry soils by using reagents (additives) to polymerize with the soils and sludges producing a cement-like mass. Two basic components of this technology are the Geo-Con/DSM Deep Soil Mixing Sy...

45

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...

46

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)

47

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...

48

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

49

Cervical Spine Motion during Transfer and Stabilization Techniques.  

Science.gov (United States)

Abstract Objectives. To compare paramedics' ability to minimize cervical spine motion during patient transfer onto a vacuum mattress with two stabilization techniques (head squeeze vs. trap squeeze) and two transfer methods (log roll with one assistant (LR2) vs. 3 assistants (LR4)). Methods. We used a crossover design to minimize bias. Each lead paramedic performed 10 LR2 transfers and 10 LR4 transfers. For each of the 10 LR2 and 10 LR4 transfers, the lead paramedic stabilized the cervical spine using the head squeeze technique five times and the trap squeeze technique five times. We randomized the order of the stabilization techniques and LR2/LR4 across lead paramedics to avoid a practice or fatigue effect with repeated trials. We measured relative cervical spine motion between the head and trunk using inertial measurement units placed on the forehead and sternum. Results. On average, total motion was 3.9° less with three assistants compared to one assistant (p = 0.0002), and 2.8° less with the trap squeeze compared to the head squeeze (p = 0.002). There was no interaction between the transfer method and stabilization technique. When examining specific motions in the six directions, the trap squeeze generally produced less lateral flexion and rotation motion but allowed more extension. Examining within paramedic differences, some paramedics were clearly more proficient with the trap squeeze technique and others were clearly more proficient with the head squeeze technique. Conclusion. Paramedics performing a log roll with three assistants created less motion compared to a log roll with only one assistant, and using the trap squeeze stabilization technique resulted in less motion than the head squeeze technique but the clinical relevance of the magnitude remains unclear. However, large individual differences suggest future paramedic training should incorporate both best evidence practice as well as recognition that there may be individual differences between paramedics. PMID:25076192

Shrier, Ian; Boissy, Patrick; Lebel, Karina; Boulay, John; Segal, Eli; Delaney, J Scott; Vacon, L Charlene; Steele, Russell J

2015-01-01

50

Assembly of amorphous clusters under floating monolayers: a comparison of in situ and ex situ techniques.  

Science.gov (United States)

We report synchrotron X-ray scattering studies of biomimetic crystallization of hydroxyapatite (the primary constituent of bone), using monolayers of fatty acid molecules floating on simulated body fluid (SBF) as well as aqueous solutions of calcium phosphate. A ?10 Å thick film of amorphous material is observed to form immediately at the molecular monolayer, consistent with the proposed formation of "Posner clusters". This layer becomes denser but not significantly thicker as the subphase concentration and the temperature approach physiological conditions. The amorphous films do not crystallize within 24 h, in contrast to prior reports of more rapid crystallization using electron microscopy on ex situ samples. However, crystallization occurs almost immediately after our films are transferred onto solid substrates. These results illustrate the importance of in situ measurements for model biomineralization experiments. PMID:24164244

Uysal, Ahmet; Stripe, Benjamin; Lin, Binhua; Meron, Mati; Dutta, Pulak

2013-11-26

51

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

52

Thermal Stability and Properties of Deformation-Processed Cu-Fe In Situ Composites  

Science.gov (United States)

This paper investigated the thermal stability, tensile strength, and conductivity of deformation-processed Cu-14Fe in situ composites produced by thermo-mechanical processing. The thermal stability was analyzed using scanning electronic microscope and transmission electron microscope. The tensile strength and conductivity were evaluated using tensile-testing machine and micro-ohmmeter, respectively. The Fe fibers in the deformation-processed Cu-14Fe in situ composites undergo edge recession, longitudinal splitting, cylinderization, break-up, and spheroidization during the heat treatment. The Cu matrix experiences recovery, recrystallization, and precipitation phase transition. The tensile strength and conductivity first increase with increasing temperature of heat treatment, reach peak values at different temperatures, and then decrease at higher temperatures. The value of parameter Z of the in situ composite reaches the peak of 2.86 × 107 MPa2 pct IACS after isothermal heat treatment at 798 K (525 °C) for 1 hour. The obtained tensile strength and conductivity of the in situ composites are 907 MPa and 54.3 pct IACS; 868 MPa and 55.2 pct IACS; 810 MPa and 55.8 pct IACS; or 745 MPa and 57.4 pct IACS, at ? = 7.8 after isochronal heat treatment for 1 hour.

Liu, Keming; Jiang, Zhengyi; Zhao, Jingwei; Zou, Jin; Lu, Lei; Lu, Deping

2015-02-01

53

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

54

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.

55

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

International Nuclear Information System (INIS)

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

56

An in situ SEM experimental study of the thermal stability of a LAST thermoelectric material  

Energy Technology Data Exchange (ETDEWEB)

Thermal stability is a key factor affecting the deployment of thermoelectric (TE) materials in the application of power generation. LAST (Lead-Antimony-Silver-Tellurium) is an emerging material with promising TE properties. The current study focused on the thermal stability of a LAST composition Ag0.86Pb19SbTe20 fabricated from a cast ingot. Using a customized heating stage, the morphology of LAST particles was studied via scanning electron microscopy (SEM) in situ, between room temperature and 575oC. The LAST material included in this study was stable below 550oC. The inclusion phase, which was antimony-rich, has a lower thermal stability than the PbTe-rich matrix. The SEM finding was also consistent with a thermogravimetrtic analysis.

Ren, Fei [ORNL; Howe, Jane Y [ORNL; Walker, Larry R [ORNL; Case, Eldon D [Michigan State University, East Lansing; Lara-Curzio, Edgar [ORNL

2011-01-01

57

In situ stabilization of mixed radioactive waste storage tanks and contaminated soil areas  

International Nuclear Information System (INIS)

Within the Department of Energy (DOE) Complex, there are a number of small (<50,000 gallons) underground Storage tanks containing mixed waste materials. The radioactive content of wastes eliminates the feasibility for hazardous waste treatment in accordance with previously prescribed Resource Conservation and Recovery Act (RCRA) technologies. As a result, DOE is funding in situ stabilization technology development for these tanks, Some of this development work has been done at the Idaho National Engineering and Environmental Laboratory (INEEL) and the initial efforts there were concentrated on the stabilization of the contents of the Test Area North (TAN) V-9 Tank. This is a 400 gallon underground tank filled with about 320 gallons of liquids and silty sediments. Sampling data indicates that approximately 50 wt% of the tank contents is aqueous-phase liquids. The vertically oriented cylindrical tank has a conical bottom and a chordal baffle that separates the tank inlet from its outlet. Access to the tank is through a six inch diameter access pipe on top of the tank. Because of the high volume, and the high concentration of aqueous-phase materials, Tank V-9 stabilization efforts have focussed on applying in situ agitation with dry feed addition to stabilize its contents. Materials selected for dry feed addition to this tank include a mixture of Aquaset IIH, and Type I/II Portland cement. This paper describes the results of proof-of-concept tests performed on full scale mockups of the Tank V-9. This proof-of-concept test were used to set operating parameters for in situ mixing, as well as evaluate how variations in Aquaset IIH/Portland cement ratio and sediment to liquid volume affected mixing of the tank

58

Development of an in situ calibration technique for combustible gas detectors  

Science.gov (United States)

This paper describes the development of an in situ calibration procedure for combustible gas detectors (CGD). The CGD will be a necessary device for future space vehicles as many subsystems in the Environmental Control/Life Support System utilize or produce hydrogen (H2) gas. Existing calibration techniques are time-consuming and require support equipment such as an environmental chamber and calibration gas supply. The in situ calibration procedure involves utilization of a water vapor electrolysis cell for the automatic in situ generation of a H2/air calibration mixture within the flame arrestor of the CGD. The development effort concluded with the successful demonstration of in situ span calibrations of a CGD.

Shumar, J. W.; Wynveen, R. A.; Lance, N., Jr.; Lantz, J. B.

1977-01-01

59

In situ aberration measurement technique based on quadratic Zernike model  

Science.gov (United States)

A novel technique (AMAI-Quad) for aberration extraction of lithographic projection based on quadratic relationship model between aerial-image intensity distribution and Zernike coefficients is proposed. Zernike coefficients in this case represent the imaging quality of lithographic projection lens in a semiconductor wafer exposure scanner. The proposed method uses principal component analysis and multivariate linear regression analysis for model generation. This quadratic model is then used to extract Zernike coefficients by nonlinear least-squares. Compared with earlier techniques, based on a linear relationship between Zernike coefficients and aerial images, proposed by Duan, the new method can extend the types of aberrations measured. The application of AMAI-Quad to computed images of lithography simulators PROLITH and Dr.LiTHO for randomly varied wavefront aberrations within a range of 50m? demonstrated an accuracy improvement of 30%.

Yang, Jishuo; Wang, Xiangzhao; Li, Sikun; Duan, Lifeng; Yan, Guanyong; Xu, Dongbo; Bourov, Anatoly Y.; Erdmann, Andreas

2012-12-01

60

In-situ verification techniques for fast critical assembly cores  

International Nuclear Information System (INIS)

Active and passive autoradiographic techniques were used to obtain piece counts of fuel plates in fast critical assembly drawers and to verify the assembly loading pattern. Active autoradiography using prompt-fission and fission-product radiation was more successful with uranium fuel while passive autoradiography was more successful with plutonium fuel. A source multiplication technique was used to measure changes in reactivity when small quantities (2-2.5 kg) of fissile material were removed from a subcritical reference core of the Zero Power Plutonium Reactor. Efforts to compensate for unsuccessful. Some compensation was achieved by replacing U-238 with polyethylene. The sensitivity for detection of partially compensated fuel removed from minimum worth regions was approximately 2.5 kg (fissile) for a core containing 2600 kg (fissile). Substitution of polyethylene was detected with a spectral index which was the ratio of the rate of the In-115 (n,?) reaction to the rate of the In-115 (n,n') reaction. This spectral index was sensitive to the presence of an 0.64-cm-thick, 5.08-cm-high polyethylene column 10-15 cm away from the indium foil. The reactivity worth of Pu-239 was also obtained as a function of location in the reactor core with the use of an inverse kinetics technique. Reactivity worths for Pu-239 varied from a maximum of 58.67 Ih/kg near the core center to a minimum of 14.86 Ih/kg at the core edge

61

Heterodyne stabilization as a possible laser frequency stabilization technique for LISA  

Science.gov (United States)

The Laser Interferometer Space Antenna is a joint NASA/ESA mission aimed at the detection of gravitational wave radiation in the frequency range from 30 uHz to 0.1 Hz. LISA uses a modified Michelson interferometer setup consisting of three identical spacecraft, arranged in an equilateral triangular constellation. It measures the differential length changes of the 5 · 109 m long interferometer arms between free-floating proof masses housed within each spacecraft. Laser pre-stabilization is required in conjunction with Time-Delay Interferometry data post-processing to monitor the armlength changes with picometer precision. A modulation/demodulation technique to stabilize the frequency of the lasers to an optical reference cavity has been proposed for a long time, but it requires several additional optical components and would need to be built as a separate system. Using a different sensing tech-nique, heterodyne interferometry, we propose a modified stabilization scheme, which similarly transfers the stability of an optical reference cavity to the laser frequency. It only uses com-ponents that are already available in the LISA assembly and can easily be integrated into the optical bench design. A similar stabilization scheme is going to be used in LISA Pathfinder. We will discuss this technique in detail and present initial experimental results, as well as predicted performances on the LISA bench.

Eichholz, Johannes

62

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1997-08-01

63

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

Science.gov (United States)

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.

Toolan, Daniel T. W.

2015-02-01

64

Using geophysical techniques to control in situ thermal remediation  

Energy Technology Data Exchange (ETDEWEB)

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.

Boyd, S.; Daily, W.; Ramirez, A.; Wilt, M. [Lawrence Livermore National Lab., CA (United States); Goldman, R.; Kayes, D.; Kenneally, K.; Udell, K. [California Univ., Berkeley, CA (United States); Hunter, R. [Infraseismic, Inc., Bakersfield, CA (United States)

1994-01-22

65

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

66

In situ monitoring of critical system component erosion by nuclear activation techniques. Final Report  

International Nuclear Information System (INIS)

Surface layer activation is a nuclear material loss measurement technique capable of measuring minute amounts of wear, erosion, or corrosion in situ. Possible applications in the area of prime power would concern parts subject to erosion in MHD and plasma sources, corrosion studies of electrodes, wearing parts in rotating generators and pitting studies of spark gap switches. The technique could be utilized in development stage experiments or in order to monitor component health in space

67

Switchable pickering emulsions stabilized by silica nanoparticles hydrophobized in situ with a conventional cationic surfactant.  

Science.gov (United States)

A stable oil-in-water Pickering emulsion stabilized by negatively charged silica nanoparticles hydrophobized in situ with a trace amount of a conventional cationic surfactant can be rendered unstable on addition of an equimolar amount of an anionic surfactant. The emulsion can be subsequently restabilized by adding a similar trace amount of cationic surfactant along with rehomogenization. This destabilization-stabilization behavior can be cycled many times, demonstrating that the Pickering emulsion is switchable. The trigger is the stronger electrostatic interaction between the oppositely charged ionic surfactants compared with that between the cationic surfactant and the (initially) negatively charged particle surfaces. The cationic surfactant prefers to form ion pairs with the added anionic surfactant and thus desorbs from particle surfaces rendering them surface-inactive. This access to switchable Pickering emulsions is easier than those employing switchable surfactants, polymers, or surface-active particles, avoiding both the complicated synthesis and the stringent switching conditions. PMID:25736518

Zhu, Yue; Jiang, Jianzhong; Liu, Kaihong; Cui, Zhenggang; Binks, Bernard P

2015-03-24

68

In-situ Calibration Techniques and Preliminary Assessment of Accuracy for NFM on ITER  

International Nuclear Information System (INIS)

Absolutely calibrated measurements of the neutron yields which need to cover both D-D and D-T phase of the international thermal-nuclear experimental reactor (ITER) are important for the evaluation of fusion power and fusion gain Q in D-D and D-T operations. This paper describes the in-situ calibration techniques and methods, the neutron sources including 252Cf and neutron generator for calibration, the preliminary accuracy assessment and the error analyses. In addition, some difficult problems regarding the in situ calibration for the neutron flux monitor (NFM) on ITER are presented and discussed. (magnetically confined plasma)

69

In-situ Calibration Techniques and Preliminary Assessment of Accuracy for NFM on ITER  

Science.gov (United States)

Absolutely calibrated measurements of the neutron yields which need to cover both D-D and D-T phase of the international thermal-nuclear experimental reactor (ITER) are important for the evaluation of fusion power and fusion gain Q in D-D and D-T operations. This paper describes the in-situ calibration techniques and methods, the neutron sources including 252Cf and neutron generator for calibration, the preliminary accuracy assessment and the error analyses. In addition, some difficult problems regarding the in situ calibration for the neutron flux monitor (NFM) on ITER are presented and discussed.

Yang, Jinwei; Yang, Qingwei; Yuan, Guoliang

2008-12-01

70

The development of an electrochemical technique for in situ calibrating of combustible gas detectors  

Science.gov (United States)

A program to determine the feasibility of performing in situ calibration of combustible gas detectors was successfully completed. Several possible techniques for performing the in situ calibration were proposed. The approach that showed the most promise involved the use of a miniature water vapor electrolysis cell for the generation of hydrogen within the flame arrestor of a combustible gas detector to be used for the purpose of calibrating the combustible gas detectors. A preliminary breadboard of the in situ calibration hardware was designed, fabricated and assembled. The breadboard equipment consisted of a commercially available combustible gas detector, modified to incorporate a water vapor electrolysis cell, and the instrumentation required for controlling the water vapor electrolysis and controlling and calibrating the combustible gas detector. The results showed that operation of the water vapor electrolysis at a given current density for a specific time period resulted in the attainment of a hydrogen concentration plateau within the flame arrestor of the combustible gas detector.

Shumar, J. W.; Lantz, J. B.; Schubert, F. H.

1976-01-01

71

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2008-02-25

72

In situ observation of defect growth beyond the irradiated region in yttria-stabilized zirconia induced by 400 keV xenon ion-beam at -90 and 30 degrees C  

International Nuclear Information System (INIS)

Single crystals of yttria-stabilized zirconia were irradiated with 400 keV Xe ion-beam at room temperature and minus 90 degrees centigrade. Defect growth was monitored in situ with Rutherford Backscattering and ion channeling techniques using a 2 MeV He ion beam

73

Robust Digital Image Stabilization Technique for Car Camera  

Directory of Open Access Journals (Sweden)

Full Text Available This research studies the digital image stabilization technique for the In-Car videos which are acquired from a car camera. Firstly, the relationship is established between the lane-line positions in a camera coordinate and an image plane. Then an analysis is performed to reveal the positions of the lane-lines in In-Car videos. Next, a digital image stabilization method for car cameras is proposed based on lane-line matching. This method begins with extracting the lane-lines from an In-Car video. Then, feature triangles are constructed to estimate the global inter-frame motions of the input video and a series of compensating motion vectors are yielded by using Kalman filter based algorithm with the inter-frame motions. Finally, repositioning the frames of the input video, according to the compensating motion vectors, can produce a stabilized In-Car video. The proposed method is resistant to the scene changes of In-Car videos. The experimental results, both for the simulated In-Car videos and the real ones, have demonstrated that the proposed method can robustly reduce the effects of undesired car camera motions on In-Car videos.

Yuefei Zhang

2011-01-01

74

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)

75

In-situ containment and stabilization of buried waste. Annual report FY 1993  

Energy Technology Data Exchange (ETDEWEB)

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.

Allan, M.L.; Kukacka, L.E.

1993-10-01

76

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

77

Nuclear techniques for in situ evaluation of coal and mineral deposits  

International Nuclear Information System (INIS)

This paper reviews developments in in situ analysis of minerals and coal by nuclear borehole logging. Developments in the oil, gas and uranium industries are not discussed in the present paper unless they have direct applications in the mineral industry (e.g. multi-element analysis and development of spectral litho-density tools). The review covers techniques developed mostly in the last decade and is based on work published in North America, Europe and Australia. (author)

78

Probing ZnAPO-34 self-assembly using simultaneous multiple in situ techniques  

OpenAIRE

The hydrothermal crystallization of ZnAPO-34 (CHA) molecular sieves has been studied for the first time using a combined in situ four technique setup utilizing SAXS/WAXS/XAFS/Raman to follow the various steps that occur during the complex transformation process of an amorphous precursor gel into a crystalline microporous material. These data are also supported by a detailed characterization of both the precursor gel (using Raman, NMR, XAFS, and TEM) and the final crystalline material (NMR, XR...

Beale, A. M.; O Brien, M. G.; Kasunic, M.; Golobic, A.; Sanchez-sanchez, M.; Lobo, A. J. W.; Lewis, D. W.; Wragg, D. S.; Nikitenko, S.; Bras, W.; Weckhuysen, B. M.

2011-01-01

79

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

80

Dynamic Probing of Nanoparticle Stability In Vivo: A Liposomal Model Assessed Using In Situ Microdialysis and Optical Imaging  

International Nuclear Information System (INIS)

Nanoparticle-mediated drug delivery and controlled release has been a vigorous research area in contemporary nano medicine. The in vivo stability of nanoparticle delivered on site is a prerequisite for the design of drug-controlled release by any means. In this study, the first methodology comprised of microdialysis and optical imaging to assess the liposome stability in vivo is reported. Macroscopically, we demonstrated the DPPG liposomes with negative surface charge fast accumulated in the rat liver upon their i.v. administration using optical imaging. Microscopically, the concurrent analysis of fluorescent molecules leaching from the liposomes, in situ sampled using microdialysis probe, provides the dynamic information of stability of DPPG liposomes locus in quo. The current combination of in situ microdialysis and optical imaging possesses a great potential for use as a platform technology to evaluate the nanoparticle stability and the bioavailability of drug payload released on targeted site in vivo.

81

Retention of in-situ surface modified silica nanoparticles for carbon dioxide foam stabilization in sandpack  

Science.gov (United States)

Nanoparticle-stabilized CO2 foams have been used for mobility control for CO2 flooding; however, raw nanosilica particles which are hydrophilic in nature tend to develop unstable CO2 foam under certain reservoir conditions. The unstable foam leads to particles aggregation resulting in complete retention while propagating in a long distance, deep into the reservoir. This can be avoided by the application of a particular coating of a specific surfactant, polymer or their combination to the surface of the nanoparticles. The in-situ surface activation of unmodified SiO2 nanoparticles by interaction with mixed surfactant (TX100:SDBS) in aqueous media has been studied with extensive experiments using variable volumetric ratios. The retention of in-situ surface-modified nanoparticles was evaluated by the injection of the dispersion of nanoparticles through a sandpack. The loading of nanoparticles in dispersion was ranging from concentrated (5 wt %) to dilute (0.1 wt %). Effluent nanoparticles concentration histories were measured to determine the retained particles in the sandpack. Little retention (pore volumes) was attained for 0.5% SiO2 and volumetric ratio of 2:1 (TX100:SDBS). These results were concluded in terms of surface charges, adsorption isotherm, surface adsorption, and DLVO theory between particles and rock.

Adil, Muhammad

2014-10-01

82

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)

83

The ultrasonic technique for in situ investigations on stones: suggestions for uses  

Science.gov (United States)

The Ultrasound Pulse Velocity (UPV) is one of the main non destructive techniques to detect both in laboratory and in situ the stone decay and many international papers of the recent years deal with its application. This technique is often executed in laboratory, where the possibility to keep constant the environmental and test conditions are a guarantee of the reliability of the results. It is known in fact the UPV are mainly conditioned by the following factors: - the characteristics of the stone tested (not only petrographic properties such as texture and structure, but even specimen dimension and water content); - the transducers features such as frequency, divergence angle , near field and wavelength; - external climate factors such as environmental temperature, humidity. In spite of the many factors affecting the measurements, UPV performed in laboratory is well correlated with mechanical strength of the stone , with its porosity and, as consequence, it is a reliable technique to detect the durability of a stone. On the other side, for in situ UPV test it is important to take into account that the measurement uncertainty is affected by the unknown water content in the stone. From tests performed on different rocks (marble, limestones, travertines, granites, gneiss, schists , sandstones) , the ratios between UPV tested in dry and saturated conditions can be > 1 or < 1 depending on the porosity . On the base of the results obtained, in this paper suggestions for UPV measurements in situ have been advanced concerning: the importance of the petrographic characterization of the stone in order to choose the suitable measurement frequency; the correct choice of transducers frequencies; the use of a reference slab, with a known UPV in dry conditions, to be exposed in the investigated site some days before the in situ tests, in order to appreciate the UPV variation due to climate factors.

Bellopede, R.; Marini, P.

2012-04-01

84

INTERNATIONAL WASTE TECHNOLOGIES EVALUATION REPORT SITE PROGRAM DEMONSTRATION, IN-SITU STABILIZATION/SOLIDIFICATION, HIALEAH, FL, VOLUME I  

Science.gov (United States)

A demonstration of the International Waste Technologies (IWT) process, utilizing the Geo-Con, Inc., deep-soil-mixing equipment has been performed under the Superfund Innovative Technology Evaluation (SITE) Program. his was the first field demonstration of an in situ stabilization...

85

CASE STUDY: IN-SITU SOLIDIFICATION/STABILIZATION OF HAZARDOUS ACID WASTE OIL SLUDGE AND LESSONS LEARNED  

Science.gov (United States)

The South 8th Street site contained a 2.5 acre oily sludge pit with very low pH waste produced by oil recycling activities. This sludge was treated using in-situ solidification/stabilization technology applied by deep soil mixing augers. The problems encountered, solutions develo...

86

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...

87

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:...

88

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.

89

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.)

90

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

OpenAIRE

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...

Chen, R. H.; Fuggle, S. V.

1993-01-01

91

Measuring wind on Mars: an overview of in situ sensing techniques  

Science.gov (United States)

Measurement of near-surface winds on Mars is doubly useful. It is scientifically important in that the near-surface winds control surface-atmosphere exchanges of water, dust, heat, and momentum; and vital for the safe landing of spacecraft. However, in situ measurement of wind is difficult due to the low density of the Martian atmosphere. There is an unusually broad variety of wind sensing techniques which are viable for use on Mars. Most past sensors have been of the hot-wire or hot-film type; however, dynamic pressure anemometers (e.g. windsocks or vanes) and ion drift anemometers have also been included on past missions. Two further promising techniques being developed for future Mars missions are ultrasonic and laser-doppler anemometry. We review the current status of sensors based on the different techniques, and suggest which may be most appropriate for the achievement of different science goals.

Wilson, C. F.

2005-08-01

92

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 50–150 °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 100–200 °C. Above this temperature, both phases collapsed due to the decomposition of the surfactants as recorded by mass spectrometry thermal gravimetrtrometry thermal gravimetric analysis.

93

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

Science.gov (United States)

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

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

2014-10-01

94

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

95

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

Directory of Open Access Journals (Sweden)

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.

Li X.L.

2010-06-01

96

Computational techniques for voltage stability assessment and control  

CERN Document Server

Presenting the continuation and bifurcation-based approaches to assess power system voltage stability, this manual provides definitions related to voltage stability based on IEEE/CIGRE voltage stability classification. It presents a tutorial introduction to the basic concepts in bifurcation theory and continuation methods.

Ajjarapu, Venkataramana

2007-01-01

97

Monitoring and controlling synthesis of bottom antireflective coating materials by in-situ FT-IR technique  

Science.gov (United States)

A number of polymeric azo dyes was synthesized in our laboratories in the course of developing and studying i-line bottom antireflective coating materials. The key step in the synthesis involved formation of a diazonium salt intermediate which is a highly energetic species and can quickly convert to a couple of by-products, depending on the reaction medium such as solvent, temperature, time, and acidity. It is important to understand the mechanistic insight and compositional changes during the course of the reaction. ASi ReactIRTM 1000 reaction analysis system was used as the on-line monitor to follow such complicate process. By using this technique, we were able to obtain high quality kinetic data for thermal stability study of the intermediate, gained good understanding of reaction mechanism, optimized the synthesis process effectively, and achieved good control of reaction yield. The in-situ FT-IR technique proved to be a powerful tool for monitoring and controlling such a process. The highly absorptive polymers synthesized by the optimized process showed good consistency of the overall lithographic performance.

Ding, Shuji; Shan, Jianhui; Khanna, Dinesh N.

1998-06-01

98

In Situ Synchrotron X-Ray Techniques for the Study of Lithium Battery Materials  

International Nuclear Information System (INIS)

The combination of in situ X-ray diffraction (XRD) and x-ray absorption spectroscopy (XAS) is a very powerful technique in the study of lithium battery cathode materials. XRD identifies the phase changes that occur during cycling and XAS gives information on the redox charge compensation processes that occur on the transition metal oxides. Because of its element specific nature XAS can identify the occurrence of redox processes on the various cations in doped oxide cathode materials. Since XAS probes short range order and is particularly useful in the study of amorphous tin based composite oxide anode materials

99

Efficiency of in situ hybridization as a function of probe size and fixation technique  

International Nuclear Information System (INIS)

In an attempt to improve fixation technique for viral RNA detection by in situ hybridization, the authors have quantitatively compared the hybridization signal obtained when measles virus or visna virus infected cell cultures were fixed with eight different fixatives and hybridized with 35S-labeled virus-complementary DNA probes of several size ranges. The highest signals were obtained with periodate-lysine-paraformaldehyde-glutaraldehyde (PLPG) fixed cells hybridized with small probes, and were 1.5- to 6.7-fold greater than those obtained with the commonly used fixative acetic ethanol. PLPG and other glutaraldehyde based fixatives also greatly improved the preservation of cellular morphology compared to acetic ethanol. (Auth.)

100

In-situ laser material process monitoring using a cladding power detection technique  

Science.gov (United States)

Progress in laser material processing may require real-time monitoring and process control for consistent quality and productivity. We report a method of in-situ monitoring of laser metal cutting and drilling using cladding power monitoring of an optical fibre beam delivery system—a technique which detects the light reflected or scattered from the workpiece. The light signal carries information about the quality of the process. Experiments involving drilling and cutting of two samples, a thin aluminum foil and a 2-mm thick stainless steel plate, confirmed the effectiveness of this method.

Su, Daoning; Norris, Ian; Peters, Chris; Hall, Denis R.; Jones, Julian D. C.

101

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

102

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

International Nuclear Information System (INIS)

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 m3 of transuranic (TRU) waste is co-mingled with over 170,000 m3 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

103

Studies of ferroelectric heterostructure thin films and interfaces via in situ analytical techniques.  

Energy Technology Data Exchange (ETDEWEB)

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 interface processes, which play critical roles in film microstructure and properties. 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.

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

1999-08-30

104

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

2005-07-01

105

In-situ stress measurement in a jointed basalt: the suitability of five overcoring techniques  

International Nuclear Information System (INIS)

Overcoring tests were conducted at the Near-Surface Test Facility (NSTF) to assess the suitability of five techniques (US Bureau of Mines borehole deformation gauge (BDG), Commonwealth Scientific and Industrial Research Organization (CSIRO) hollow inclusion stress cell, epoxy inclusion, Lulea triaxial gauge (LuH gauge), and Council for Scientific and Industrial Research (CSIR) doorstopper) for in situ stress determination in a closely jointed basalt. This effort is in support of the Basalt Waste Isolation project, which is studying the feasibility of locating a nuclear waste repository in the basalts of the Hanford Site in southeastern Washington. This paper preents the results from the overcoring study that formed the basis for selection of two techniques to be used during the further exploration of the basalt formations at depth

106

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

Energy Technology Data Exchange (ETDEWEB)

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.

Lovley, Derek R

2012-11-28

107

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. Initude 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

108

In situ monitoring technique for determining post remedial action concentrations of radium in soil  

International Nuclear Information System (INIS)

There are several federal programs where action is being carried out to clean up or otherwise control residual radioactivity, at levels above current guidelines, which exists as a result of activities carried out during the early years of this nation's atomic energy program. At most of the sites which are candidates for clean up, the principal radionuclide of concern is Ra-226. Following excavation of open land areas, measuring the concentration of Ra-226 in soil samples from discrete locations or by indirect monitoring techniques. For application in remedial action programs, as in situ monitoring technique has been employed with favorable results. Instrumentation for this technique consists of a 2'' x 2'' NaI probe mounted on a wheeled dolly so that the detector is approximately 12'' above the ground. Radiation levels are read out using a portable digital ratemeter/scaler. Readings with this device are representative of photons which reach the detector from a ground area subtended by projection of the cone shield side wall. This system was calibrated using facilities at the Department of Energy Technical Measurements Center, Grand Junction, CO. A series of measurements at this facility revealed a conversion factor which relates the response for Ra-226 in dry soil: Ra-226 pCi/g = 1.06 x 10-3 (cpm) - 2.94. The correlation coefficient was 0.99. This technique has been used extensively to predict the Ra-226 soil concentration averaged over individual 100 m2 areas

109

Application of voltammetric techniques at microelectrodes to the study of the chemical stability of highly reactive species.  

Science.gov (United States)

The application of voltammetric techniques to the study of chemical speciation and stability is addressed both theoretically and experimentally in this work. In such systems, electrode reactions are coupled to homogeneous chemical equilibria (complexations, protonations, ion associations, ...) that can be studied in a simple, economical, and accurate way by means of electrochemical methods. These are of particular interest when some of the participating species are unstable given that the generation and characterization of the species are performed in situ and on a short time scale. With the above aim, simple explicit solutions are presented in this article for quantitative characterization with any voltammetric technique and with the most common electrode geometries. From the theoretical results obtained, it is pointed out that the use of square-wave voltammetry in combination with microelectrodes is very suitable. Finally, the theory is applied to the investigation of the ion association between the anthraquinone radical monoanion and the tetrabutylammonium cation in acetonitrile medium. PMID:25551335

Laborda, Eduardo; Olmos, José-Manuel; Torralba, Encarnación; Molina, Angela

2015-02-01

110

Calibration of an in-situ BEGe detector using semi-empirical and Monte Carlo techniques  

Energy Technology Data Exchange (ETDEWEB)

In the case of a nuclear or radiological accident a rapid estimation of the qualitative and quantitative characteristics of the potential radioactive pollution is needed. For aerial releases the radioactive pollutants are finally deposited on the ground forming a surface source. In this case, in-situ {gamma}-ray spectrometry is a powerful tool for the determination of ground pollution. In this work, the procedure followed at the Nuclear Engineering Department of the National Technical University of Athens (NED-NTUA) for the calibration of an in-situ Broad Energy Germanium (BEGe) detector, for the determination of gamma-emitting radionuclides deposited on the ground surface, is presented. BEGe detectors due to their technical characteristics are suitable for the analysis of photons in a wide energy region. Two different techniques were applied for the full-energy peak efficiency calibration of the BEGe detector in the energy region 60-1600 keV: {center_dot}a semi-empirical method based on the determination of the peak efficiency for a surface source geometry, from the experimentally obtained efficiency for a point source geometry {center_dot}a numerical method which is based on Monte Carlo simulation. For this purpose the PENELOPE computer code was employed. For the determination of the geometrical characteristics of the detector - a key parameter for the simulation accuracy - an iterative procedure involving a series of experiments and simulations was applied. Full-energy peak efficiencies determined using the two methods agree within statistical uncertainties.

Agrafiotis, K.; Karfopoulos, K.L. [Nuclear Engineering Department, School of Mechanical Engineering, National Technical University of Athens, 15780 Athens (Greece); Anagnostakis, M.J., E-mail: managno@nuclear.ntua.gr [Nuclear Engineering Department, School of Mechanical Engineering, National Technical University of Athens, 15780 Athens (Greece)

2011-08-15

111

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)

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)

Escusol Tomey, M.; Rodriguez Abad, R.

2014-07-01

112

In situ detection of apoptosis by the TUNEL assay: an overview of techniques.  

Science.gov (United States)

Apoptosis, or programmed cell death, plays an important role in normal development and homeostasis of adult tissues. Apoptosis has also been linked to many disease states, including cancer. One of the biochemical hallmarks of apoptosis is the generation of free 3'-hydroxyl termini on DNA via cleavage of chromatin into single and multiple oligonuleosome-length fragments. The TdT-mediated dUTP-biotin nick end labeling (TUNEL) assay exploits this biochemical hallmark by labeling the exposed termini of DNA, thereby enabling visualization of nuclei containing fragmented DNA. This review outlines the general method for in situ TUNEL staining of cultured cells and tissue sections, and highlights recent improvements in the technique and limitations of the assay. PMID:21057916

Loo, Deryk T

2011-01-01

113

Use of noninvasive geophysical techniques for the In Situ Vitrification Program  

Energy Technology Data Exchange (ETDEWEB)

In situ vitrification (ISV) is a waste pit remediation technology that can potentially eliminate the need for pit excavation. The ISV program at the Idaho National Engineering Laboratory (INEL) funded this study to evaluate geophysical techniques that might be useful for performing detailed screening of the materials, soil conditions, and local geology of waste pits targeted for remediation. The evaluation focuses on a specific set of characterization objectives developed by ISV engineers. The objectives are based on their assessment of safety, environmental, and cost efficiency issues associated with the ISV process. A literature review of geophysical case histories was conducted and a geophysical survey was performed at the INEL simulated waste pit so that the evaluation could be based on demonstrable results.

Josten, N.E.; Marts, S.T.; Carpenter, G.S.

1991-11-01

114

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.

115

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

DEFF Research Database (Denmark)

A key information for understanding and controlling the anaerobic biogas process is the concentration of Volatile Fatty Acids (VFA). However, access to this information has so far been limited to off-line measurements by manual time and labour consuming methods. We have developed a new technique 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 pumping and filtering. Using this filtration technique together with commercially available membrane filters we have constructed a VFA sensor system that can perform automatic analysis on animal slurry at a frequency as high as every 15 minutes. The VFA sensor has been tested for a period of more than 60 days with more than 1000 samples on both a fullscale biogas plant and lab-scale reactors. The measuring range covers specific measurements of acetate, propionate, iso-/n-butyrate and iso-/n-valerate from 0.1 to 50 mM (6–3,000 mg).

Pind, Peter Frode; Angelidaki, Irini

2002-01-01

116

Transient stability emergency control combining open-loop and closed-loop technique  

OpenAIRE

An on-line transient stability emergency control approach is proposed, which couples an open-loop and a closed-loop emergency control technique. The open-loop technique uses on-line transient stability assessment in order to adapt the settings of automatic system protection schemes to the current operating conditions. On the other hand, the closed-loop technique uses measurements in order to design and trigger countermeasures, after the contingency has actually happened, then to continue moni...

Ruiz-vega, Daniel; Glavic, Mevludin; Ernst, Damien

2003-01-01

117

A double labeling technique for performing immunocytochemistry and in situ hybridization in virus infected cell cultures and tissues  

International Nuclear Information System (INIS)

This report describes a combined immunocytochemical and in situ hybridization procedure which allows visualization of cellular or viral antigens and viral RNA in the same cell. Cultures infected with visna or measles virus were fixed in periodate-lysine-paraformaldehyde-glutaraldehyde, stained by the avidin-biotin-peroxidase technique using antibodies to viral or cellular proteins and then incubated with radiolabeled specific DNA probes (in situ hybridization). This technique provides a new approach to the study of viral pathogenesis by: (1) identifying the types of cells which are infected in the host and (2) identifying points of blockade in the virus life cycle during persistent infections. (Auth.)

118

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1998-12-01

119

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

120

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1980-12-01

121

Fundamental study on in-situ repair technique of armor tiles for fusion experimental reactors  

International Nuclear Information System (INIS)

In order to establish in-situ maintenance technique with robotics, rebrazing tests of C/C composite armor (MFC-1) tile and Oxygen Free High thermal conductivity Copper (OFHC) and its strength tests were performed, supposing to repair damaged target plate structure in the divertor components on the operation of fusion experimental reactors. The following conclusions were derived; (1) The brazed specimen of MFC-1/OFHC by one seat of Ag-Ti-Cu braze material (thickness: 50 ?m) exhibits very good mechanical performance. Rebrazing technique can be applied to the joint MFC-1/OFHC at least three times. (2) Rebrazing joint shows about 1.5 times higher strength than that of brazing joint and MFC-1. (3) Rebrazing joint shows the same data scattering of that of brazing joint and MFC-1. (4) In order to perform short time replacement of new armor tile, the distance between coil and armor surface was kept within 2 mm to transfer heating power into brazing position with high efficiency. (author)

122

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

123

Testing the Chemical/Structural Stability of Proton Conducting Perovskite Ceramic Membranes by in Situ/ex Situ Autoclave Raman Microscopy.  

Science.gov (United States)

Ceramics, which exhibit high proton conductivity at moderate temperatures, are studied as electrolyte membranes or electrode components of fuel cells, electrolysers or CO2 converters. In severe operating conditions (high gas pressure/high temperature), the chemical activity towards potentially reactive atmospheres (water, CO2, etc.) is enhanced. This can lead to mechanical, chemical, and structural instability of the membranes and premature efficiency loss. Since the lifetime duration of a device determines its economical interest, stability/aging tests are essential. Consequently, we have developed autoclaves equipped with a sapphire window, allowing in situ Raman study in the 25-620 °C temperature region under 1-50 bar of water vapor/gas pressure, both with and without the application of an electric field. Taking examples of four widely investigated perovskites (BaZr0.9Yb0.1O3-?, SrZr0.9Yb0.1O3-?, BaZr0.25In0.75O3-?, BaCe0.5Zr0.3Y0.16Zn0.04O3-?), we demonstrate the high potential of our unique set-up to discriminate between good/stable and instable electrolytes as well as the ability to detect and monitor in situ: (i) the sample surface reaction with surrounding atmospheres and the formation of crystalline or amorphous secondary phases (carbonates, hydroxides, hydrates, etc.); and (ii) the structural modifications as a function of operating conditions. The results of these studies allow us to compare quantitatively the chemical stability versus water (corrosion rate from ~150 µm/day to less than 0.25 µm/day under 200-500 °C/15-80 bar PH2O) and to go further in comprehension of the aging mechanism of the membrane. PMID:24957060

Slodczyk, Aneta; Zaafrani, Oumaya; Sharp, Matthew D; Kilner, John A; Dabrowski, Bogdan; Lacroix, Olivier; Colomban, Philippe

2013-01-01

124

Testing the Chemical/Structural Stability of Proton Conducting Perovskite Ceramic Membranes by in Situ/ex Situ Autoclave Raman Microscopy  

Science.gov (United States)

Ceramics, which exhibit high proton conductivity at moderate temperatures, are studied as electrolyte membranes or electrode components of fuel cells, electrolysers or CO2 converters. In severe operating conditions (high gas pressure/high temperature), the chemical activity towards potentially reactive atmospheres (water, CO2, etc.) is enhanced. This can lead to mechanical, chemical, and structural instability of the membranes and premature efficiency loss. Since the lifetime duration of a device determines its economical interest, stability/aging tests are essential. Consequently, we have developed autoclaves equipped with a sapphire window, allowing in situ Raman study in the 25–620 °C temperature region under 1–50 bar of water vapor/gas pressure, both with and without the application of an electric field. Taking examples of four widely investigated perovskites (BaZr0.9Yb0.1O3??, SrZr0.9Yb0.1O3??, BaZr0.25In0.75O3??, BaCe0.5Zr0.3Y0.16Zn0.04O3??), we demonstrate the high potential of our unique set-up to discriminate between good/stable and instable electrolytes as well as the ability to detect and monitor in situ: (i) the sample surface reaction with surrounding atmospheres and the formation of crystalline or amorphous secondary phases (carbonates, hydroxides, hydrates, etc.); and (ii) the structural modifications as a function of operating conditions. The results of these studies allow us to compare quantitatively the chemical stability versus water (corrosion rate from ~150 µm/day to less than 0.25 µm/day under 200–500 °C/15–80 bar PH2O) and to go further in comprehension of the aging mechanism of the membrane. PMID:24957060

Slodczyk, Aneta; Zaafrani, Oumaya; Sharp, Matthew D.; Kilner, John A.; Dabrowski, Bogdan; Lacroix, Olivier; Colomban, Philippe

2013-01-01

125

Stability and Reactive Power Compensation Techniques in Wind Farm  

Directory of Open Access Journals (Sweden)

Full Text Available Wind energy’s presence in the electric power system has dramatically grown over the past decade and will continue to grow worldwide as many countries have planned future developments. Large number of wind turbines are being installed and connected to power systems. In some of the countries the penetration of wind power is significant high so as to affect the power quality, system operation and control and power system stability. In this paper an attempt is made to predict the reactive power burden of the wind farm based on conventional fixed speed induction generator during wind variation and fault condition. PSCAD/EMTDC based large scale wind farm model is developed where STATCOM is introduced as an active voltage and reactive power supporter to increase the power system stability. STATCOM unit injects reactive power to mitigate power quality problems and to get stable grid operation.

Kadam D.P

2014-02-01

126

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)

127

Techniques for Improving the Stability of Soft Inplane Hingeless Rotors  

Science.gov (United States)

The influence of basic parameters that govern flap lag stability of hingeless rotor blades in hover is reviewed, and potential methods are studied for improving the lead lag damping of soft inplane configurations for low thrust conditions. These conditions are relevant for ground and air resonance stability of coupled rotor body dynamic systems. Results indicate that the isolated rotor blade lead lag damping can be usefully increased by a combination of flap lag elastic coupling and pitch lag coupling. For a typical soft inplane configuration, 6% of critical damping can be obtained for moderate pitch lag coupling. For large values of the coupling parameters, the lead lag frequency is substantially reduced at high pitch angles and airfoil stall effects also reduce the lead lag damping.

Ormiston, R. A.

1974-01-01

128

An in situ transmission electron microscope study of the thermal stability of near-surface microstructures induced by deep rolling and laser-shock peening  

Energy Technology Data Exchange (ETDEWEB)

We investigate the thermal stability of near-surface microstructures induced by deep rolling and laser-shock peening in AISI 304 stainless steel (AISI 304) and Ti-6Al-4V using in situ transmission electron microscopy. The improvements in fatigue resistance at elevated temperature are related to the high-temperature stability of the work-hardened near-surface microstructure.

Altenberger, I.; Stach, E.A.; Liu, G.; Nalla, R.K.; Ritchie, R.O

2003-06-15

129

An in situ transmission electron microscope study of the thermal stability of near-surface microstructures induced by deep rolling and laser-shock peening  

International Nuclear Information System (INIS)

We investigate the thermal stability of near-surface microstructures induced by deep rolling and laser-shock peening in AISI 304 stainless steel (AISI 304) and Ti-6Al-4V using in situ transmission electron microscopy. The improvements in fatigue resistance at elevated temperature are related to the high-temperature stability of the work-hardened near-surface microstructure

130

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

131

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

132

Determination of the effect of Hf additions on phase stability in Nb-silicide based in-situ composites  

International Nuclear Information System (INIS)

In-situ composites based on Nb-Si alloys are potential candidates for application as structural materials in future aircraft engines. In order to achieve the balance of properties that is required, additional alloying species, such as Ti, Hf, Mo, Cr, Al are employed. The present paper describes the effect of Hf additions on phase stability of Nb-Si alloys. Liquid-solid and solid-state phase equilibria have been investigated. The Nb-Hf-Si liquidus surface and the isothermal section at 1,500 C will be described. A broad range of Nb and Hf compositions were investigated for Si concentrations up to 35.0%

133

[Improvement of stabilization technique of cervical vertebrae using cylindrical implants].  

Science.gov (United States)

The algorithm for cervical interbody stabilization with the use of vertical cylindrical mesh implant was improvement. Implementation of the developed method allows to reduce the load per unit area of bone bodies of recorded vertebrae in contact with the terminal part of the implant, which reduces the risk of loss of correction of the deformity after surgery. Results of surgical treatment of 5 patients for diseases and injuries of the cervical spine show the effectiveness of the method and the possibility of its application in clinical practice. PMID:23888724

Barysh, A E; Buznitski?, R I

2013-04-01

134

Dimensional stability of a novel polyvinyl siloxane impression technique  

Scientific Electronic Library Online (English)

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

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

2014-04-01

135

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)

136

Determining Nutritive Values of Alfalfa Cuts Using in situ and Gas Production Techniques  

OpenAIRE

In order to determine of nutritive value of alfalfa in different cuts using in situ and gas production technique, this study was carried out. Three wethers (49±2.6 kg) were used in in situ method. The gas production was measured at 2,4,6,8,12,16,24,36,48,72 and 96 h and ruminal dry matter and crude protein disappearance were measured at 0,4,8,12,16,24,36,48,72 and 96 h. Dry matter degradability?s in first, second and third cuts of alfalfa at 96 h were 60.47, 64.71 and 64.36%, respectively. ...

Taghizadeh, A.; Palangi, V.; Safamehr, A.

2008-01-01

137

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2014-09-15

138

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

Science.gov (United States)

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.

Lugani, L.; Carlin, J.-F.; Py, M. A.; Grandjean, N.

2014-09-01

139

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

International Nuclear Information System (INIS)

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.

140

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

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

2014-09-01

141

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

142

Cyanea capillata Bell Kinematics Analysis through Corrected In Situ Imaging and Modeling Using Strategic Discretization Techniques  

Science.gov (United States)

Obtaining accurate kinematic data of animals is essential for many biological studies and bio-inspired engineering. Many animals, however, are either too large or too delicate to transport to controlled environments where accurate kinematic data can be easily obtained. Often, in situ recordings are the only means available but are often subject to multi-axis motion and relative magnification changes with time leading to large discrepancies in the animal kinematics. Techniques to compensate for these artifacts were applied to a large jellyfish, Cyanea capillata, freely swimming in ocean waters. The bell kinematics were captured by digitizing exumbrella profiles for two full swimming cycles. Magnification was accounted for by tracking a reference point on the ocean floor and by observing the C. capillata exumbrella arclength in order to have a constant scale through the swimming cycles. A linear fit of the top bell section was used to find the body angle with respect to the camera coordinate system. Bell margin trajectories over two swimming cycles confirmed the accuracy of the correction techniques. The corrected profiles were filtered and interpolated to provide a set of time-dependent points along the bell. Discrete models of the exumbrella were used to analyze the bell kinematics. Exumbrella discretization was conducted using three different methods. Fourier series were fitted to the discretized models and subsequently used to analyze the bell kinematics of the C. capillata. The analysis showed that the bell did not deform uniformly over time with different segments lagging behind each other. Looping of the bell trajectory between contraction and relaxation was also present through most of the exumbrella. The bell margin had the largest looping with an outer path during contraction and inner path during relaxation. The subumbrella volume was approximated based on the exumbrella kinematics and was found to increase during contraction. PMID:25541980

Villanueva, Alex A.; Priya, Shashank

2014-01-01

143

Assessment of slope stability using PS-InSAR technique  

Science.gov (United States)

In this research work, PS-InSAR approach is envisaged to monitor slope stability of landslides prone areas in Nainital and Tehri region of Uttarakhand, India. For the proposed work, Stanford Method for Persistent Scatterers (StaMPS) based PS-InSAR is used for processing ENVISAT ASAR C-Band data stacks of study area which resulted in a time series 1D-Line of Sight (LOS) map of surface displacement. StaMPS efficiently extracted the PS pixels on the unstable slopes in both areas and the time series 1D-LOS displacement map of PS pixels indicates that those areas in Nainital and Tehri region have measurement pixels with maximum displacement away from the satellite of the order of 22 mm/year and 17.6 mm/year respectively

Dwivedi, R.; Varshney, P.; Tiwari, A.; Singh, A. K.; Dikshit, O.

2014-11-01

144

Development of a pulsed heating technique for stability testing in the westinghouse LCP coil  

International Nuclear Information System (INIS)

A pulsed heating technique applicable to the stability testing of cable-in-conduit conductors cooled by flowing supercritical helium is reported. The technique utilizes induction heaters installed externally to the conductor sheat and powered by a resonating capacitive discharge supply. The application of this technique to the stability testing of subsized, and full-sized prototypical samples of the Westinghouse Large Coil Program (LCP) conductor is discussed and modifications for adapting this method for testing in the Westinghouse LCP coil are recommended. These magnets are for fusion applications. 4 refs

145

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 stabilizatio power capacity for frequency stabilization

146

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

Directory of Open Access Journals (Sweden)

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

Besharati Maghsoud

2008-01-01

147

Preparation of grout for stabilization of abandoned in-situ oil shale retorts  

Energy Technology Data Exchange (ETDEWEB)

A process for the preparation of grout from burned shale by treating the burned shale in steam at approximately 700.degree. C. to maximize the production of the materials alite and larnite. Oil shale removed to the surface during the preparation of an in-situ retort is first retorted on the surface and then the carbon is burned off, leaving burned shale. The burned shale is treated in steam at approximately 700.degree. C. for about 70 minutes. The treated shale is then ground and mixed with water to produce a grout which is pumped into an abandoned, processed in-situ retort, flowing into the void spaces and then bonding up to form a rigid, solidified mass which prevents surface subsidence and leaching of the spent shale by ground water.

Mallon, Richard G. (Livermore, CA)

1982-01-01

148

Preparation of grout for stabilization of abandoned in-situ oil shale retorts  

Energy Technology Data Exchange (ETDEWEB)

A process is claimed for the preparation of grout from burned shale by treating the burned shale in steam at approximately 7000 C to maximize the production of the materials alite and larnite. Oil shale removed to the surface during the preparation of an in-situ retort is first retorted on the surface and then the carbon is burned off, leaving burned shale. The burned shale is treated in steam at approximately 7000 C for about 70 minutes. The treated shale is then ground and mixed with water to produce a grout which is pumped into an abandoned, processed in-situ retort, flowing into the void spaces and then bonding up to form a rigid, solidified mass which prevents surface subsidence and leaching of the spent shale by ground water.

Mallon, R.G.

1982-03-23

149

Preparation of grout for stabilization of abandoned in-situ oil shale retorts. [Patent application  

Energy Technology Data Exchange (ETDEWEB)

A process is described for the preparation of grout from burned shale by treating the burned shale in steam at approximately 700/sup 0/C to maximize the production of the materials alite and larnite. Oil shale removed to the surface during the preparation of an in-situ retort is first retorted on the surface and then the carbon is burned off, leaving burned shale. The burned shale is treated in steam at approximately 700/sup 0/C for about 70 minutes. The treated shale is then ground and mixed with water to produce a grout which is pumped into an abandoned, processed in-situ retort, flowing into the void spaces and then bonding up to form a rigid, solidified mass which prevents surface subsidence and leaching of the spent shale by ground water.

Mallon, R.G.

1979-12-07

150

Improved Flotation Technique for Microscopy of In Situ Soil and Sediment Microorganisms  

OpenAIRE

An improved flotation method for microscopy of in situ soil and sediment microorganisms was developed. Microbial cells were released into gellike flotation films that were stripped from soil and sediment aggregates as these aggregates were submerged in 0.5% solutions of polyvinylpyrrolidone. The use of polyvinylpyrrolidone solutions instead of water facilitated the release of films from saturated samples such as aquifer sediments as well as from typical surface soils. In situ microbial morpho...

Bone, T. L.; Balkwill, D. L.

1986-01-01

151

Rumen escape nitrogen from forages in sheep: comparison of in situ and in vitro techniques using in vivo data  

OpenAIRE

The objective of this study was to relate in vivo data of rumen escape N (REN) of forages with REN estimated from models and with determinations of rumen undegradable N. For these determinations and models measurements from in situ and in vitro techniques were used. Eleven forages were investigated in vivo using sheep with cannula in the rumen, duodenum and ileum. These forages were fresh, silage and hay from lucerne and orchard grass, and fresh, silage and haylage from red clover, and silage...

Gosselink, J. M. J.; Dulphy, J. P.; Poncet, C.; Aufre?re, J.; Tamminga, S.; Cone, J. W.

2004-01-01

152

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

OpenAIRE

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 ...

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

2012-01-01

153

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

Energy Technology Data Exchange (ETDEWEB)

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

Sittiphan, Torpong [Program of Petrochemistry and Polymer Sciences, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Prasassarakich, Pattarapan [Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Poompradub, Sirilux, E-mail: sirilux.p@chula.ac.th [Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand)

2014-02-15

154

Optimization of UPFC Controller Parameters Using Bacterial Foraging Technique for Enhancing Power System Stability  

OpenAIRE

To control the power flow,for increasing the transmission capacity & for power system stability,FACT devices are used.Unified Power Flow Controller is most widely used. This paper presents a novelBacterial foraging technique (BFO) for optimizing the PI controller parameters of UPFC for the transient stability enhancement of SMIB system .Complete modeling is done for SMIB system with UPFC controller.PI controller parameters computedbyconventional method [23] are usedas base for BFO, Bacter...

Poonam Singhal

2014-01-01

155

Automation and combination of linear-programming based stabilization techniques in column generation  

OpenAIRE

The convergence of a column generation algorithm can be improved in practice by using so-called stabilization techniques. Proximal methods based on penalising the deviation from the incumbent dual solution have become standards of the domain. However, the analysis of such methods is important to understand the mechanism on which they rely, to appreciate the difference between methods, and to derive intelligent schemes to adjust their parameters. As stabilization procedures for column generati...

Pessoa, A.; Sadykov, R.; Uchoa, E.; Vanderbeck, F.

2014-01-01

156

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

International Nuclear Information System (INIS)

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

157

A Genetic Algorithm-based Technique to Enhance H? Controller: Stabilizes Acceleration in PMSM  

Directory of Open Access Journals (Sweden)

Full Text Available In recent years, a high class evolution has been achieved by control systems in different application areas. Acceleration control in Permanent Magnet Synchronous Motor is one among the noteworthy applications of evolving control systems. Though numerous methodologies have been proposed in the literature, they perform thecontrol operations statically. Moreover, controllers are very rarely used for this purpose. This leads to the problem of delayed stability in the acceleration/velocity control of Permanent Magnet Synchronous Motor. In this paper, a Genetic Algorithm-based technique is proposed to accomplish effective stability in Permanent Magnet Synchronous Motor controlling operations. This technique introduces multiples of rotor mass (considered without load, along with the system parameters. A GA-based optimization is performed over the considered system parameters and so acceleration achieves stability in a very short time. The proposed technique is tested with a standard ? H problem and the results are evaluated by comparing them with that of an existing H-infinity control technique. The implementation results have shown that the proposed technique achieves stability of acceleration as well as velocity in a much shorter time compared to the existing technique.

T.S. Viswanath

2010-12-01

158

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

Directory of Open Access Journals (Sweden)

Full Text Available La hibridación in situ fluorescente (FISH, es una técnica que emplea sondas de oligonucleótidos marcadas con fluorocromos las cuales van dirigidas hacia secuencias específicas del ácido ribonucleico ribosomal (ARNr, lo que permite la identificación rápida y específica de células microbianas ya sea que estén como células individuales o se encuentren agrupadas en su ambiente natural. El conocimiento de la composición y distribución de los microorganismos en los hábitats naturales, proporciona un soporte sólido para comprender la interacción entre las diversas especies que componen el micro hábitat. El objetivo de la revisión es presentar la forma como ha evolucionado la hibridación, el empleo del ARNr como molécula diana, los tipos de marcaje, los marcadores fluorescentes empleados hoy en día, la metodología, así como las mejoras que se le han hecho a la técnica FISH al emplearse en conjunto con otras técnicas en la identificación microbiana. Salud UIS 2011; 43 (3: 307-316Fluorescence 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 grouped 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

Raúl Rodríguez Martínez

2011-12-01

159

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

Scientific Electronic Library Online (English)

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

Raúl, Rodríguez Martínez.

2011-12-01

160

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

161

Biodegradable injectable in situ implants and microparticles for sustained release of montelukast: in vitro release, pharmacokinetics, and stability.  

Science.gov (United States)

The objective of this study was to investigate the sustained release of a hydrophilic drug, montelukast (MK), from two biodegradable polymeric drug delivery systems, in situ implant (ISI) and in situ microparticles (ISM). N-Methyl pyrrolidone (NMP), dimethyl sulfoxide (DMSO), triacetin, and ethyl acetate were selected as solvents. The release of 10% (w/v) MK from both systems containing poly-lactic-co-glycolic acid (PLGA) as the biodegradable polymer was compared. Upon contact with the aqueous medium, the PLGA in ISI and ISM systems solidified resulting in implants and microparticles, respectively. The in vitro drug release from the ISI system showed marked difference from miscible solvents (NMP and DMSO) than the partially miscible ones (triacetin and ethyl acetate), and the drug release decreased with increased PLGA concentration. In the ISM system, the initial in vitro drug release decreased with decreased ratio of polymer phase to external oil phase. In vivo studies in rats showed that ISM had slower drug release than the drug release from ISI. Also, the ISM system when compared to ISI system had significantly reduced initial burst effect. In vitro as well as the in vivo studies for both ISI and ISM systems showed sustained release of MK. The ISM system is suitable for sustained release of MK over 4-week period with a lower initial burst compared to the ISI system. Stability studies of the ISI and ISM formulations showed that MK is stable in the formulations stored at 4°C for more than 2 years. PMID:24648158

Ahmed, Tarek A; Ibrahim, Hany M; Samy, Ahmed M; Kaseem, Alaa; Nutan, Mohammad T H; Hussain, Muhammad Delwar

2014-06-01

162

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

163

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)

164

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

165

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

Science.gov (United States)

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.

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

2000-01-01

166

Pole placement technique for PSS and TCSC-based stabilizer design using simulated annealing  

Energy Technology Data Exchange (ETDEWEB)

A pole placement technique for power system stabilizer (PSS) and thyristor controlled series capacitor (TCSC) based stabilizer using simulated annealing (SA) algorithm is presented in this paper. The proposed approach employs SA optimization technique to PSS (SAPSS) and TCSC-based stabilizer (SACSC) design. The design problem is formulated as an optimization problem where SA is applied to search for the optimal setting of the proposed SAPSS and SACSC parameters. A pole placement-based objective function to shift the dominant eigenvalues to the left in the s-plane is considered. The proposed SAPSS and SACSC have been examined on a weakly connected power system with different disturbances, loading conditions, and system parameter variations. Eigenvalue analysis and nonlinear simulation results show the effectiveness and the robustness of the proposed stabilizers and their ability to provide efficient damping of low frequency oscillations. In addition, the performance of the proposed stabilizers outperforms that of the conventional power system stabilizer (CPSS). It is also observed that the proposed SACSC improves greatly the voltage profile of the system under severe disturbances. (author)

Abido, M.A. [King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia). Dept. of Electrical Engineering

2000-11-01

167

Multi-Scale Mechanical Probing Techniques To Investigate The Stability Of BEOL Layer Stacks With Sub-100 nm Structures  

Science.gov (United States)

The stress levels induced by chip-package interaction (CPI) impose an increased risk of mechanical failure on advanced backend-of-line (BEOL) layer stacks in microelectronic circuits if they contain fragile ultralow-k (ULK) interlayer dielectric (ILD) films. On the one hand, multilevel finite element modeling is used to assess the potential risk at an early stage of the development of new microelectronic products. On the other hand, the theoretical models need as accurate as possible materials parameters as an input to provide realistic results. Moreover, it is highly desirable to have multi-scale experimental probes available which can provide complementary data to support the modeling calculations. The present paper provides an overview about various mechanical probing techniques which operate on the scale of less than 100 nm up to more than 100 ?m. In this way, typical feature sizes are covered which occur from the package level via solder bumps or copper pillars down to small Cu/ULK interconnect structures. The experimental approaches are based on nanoindentation with lateral force detection and in-situ scanning probe microscopy (SPM) imaging capabilities, and they include a novel technique named bump assisted BEOL stability indentation (BABSI) test. Especially, the interrelation between small-scale mechanical properties of ULK dielectric films and stresses acting on larger scales are quantitatively assessed by means of the experimental approaches described here.

Geisler, Holm; Lehr, Matthias U.; Platz, Alexander; Mayer, Ulrich; Hofmann, Petra; Engelmann, Hans-Jürgen

2011-09-01

168

TECHNOLOGY EVALUATION REPORT, SITE PROGRAM DEMONSTRATION OF THE INTERNATIONAL WASTE TECHNOLOGIES IN SITU STABILIZATION/-SOLIDIFICATION TECHNOLOGY, HIALEAH, FL, VOLUME II  

Science.gov (United States)

A demonstration of the International Waste Technologies (IWT) process, utilizing the Geo-Con, Inc., deep-soil-mixing equipment has been performed under the Superfund Innovative Technology Evaluation (SITE) Program. his was the first field demonstration of an in situ stabilization...

169

In-situ, real-time, studies of film growth processes using ion scattering and direct recoil spectroscopy techniques.  

Energy Technology Data Exchange (ETDEWEB)

Time-of-flight ion scattering and recoil spectroscopy (TOF-ISARS) enables the characterization of the composition and structure of surfaces with 1-2 monolayer specificity. It will be shown that surface analysis is possible at ambient pressures greater than 3 mTorr using TOF-ISARS techniques; allowing for real-time, in situ studies of film growth processes. TOF-ISARS comprises three analytical techniques: ion scattering spectroscopy (ISS), which detects the backscattered primary ion beam; direct recoil spectroscopy (DRS), which detects the surface species recoiled into the forward scattering direction; and mass spectroscopy of recoiled ions (MSRI), which is 3 variant of DRS capable of isotopic resolution for all surface species--including H and He. The advantages and limitations of each of these techniques will be discussed. The use of the three TOF-ISARS methods for real-time, in situ film growth studies at high ambient pressures will be illustrated. It will be shown that MSRI analysis is possible during sputter deposition. It will be also be demonstrated that the analyzer used for MSRI can also be used for time of flight secondary ion mass spectroscopy (TOF-SIMS) under high vacuum conditions. The use of a single analyzer to perform the complimentary surface analytical techniques of MSRI and SIMS is unique. The dwd functionality of the MSRI analyzer provides surface information not obtained when either MSRI or SIMS is used independently.

Smentkowski, V. S.

1999-04-22

170

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

DEFF Research Database (Denmark)

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.

Svendsen, Claus Bo; Boye, Mette

2009-01-01

171

In-situ measurements of the radiation stability of amino acids at 15-140 K  

CERN Document Server

We present new kinetics data on the radiolytic destruction of amino acids measured in situ with infrared spectroscopy. Samples were irradiated at 15, 100, and 140 K with 0.8-MeV protons, and amino-acid decay was followed at each temperature with and without H$_2$O present. Observed radiation products included CO$_2$ and amines, consistent with amino-acid decarboxylation. The half-lives of glycine, alanine, and phenylalanine were estimated for various extraterrestrial environments. Infrared spectral changes demonstrated the conversion from the non-zwitterion structure NH$_2$-CH$_2$(R)-COOH at 15 K to the zwitterion structure $^+$NH$_3$-CH$_2$(R)-COO$^-$ at 140 K for each amino acid studied.

Gerakines, P A; Moore, M H; Bell, J -L

2015-01-01

172

Stabilization of ambient sensitive atomic layer deposited lanthanum aluminates by annealing and in situ capping  

Science.gov (United States)

We have studied the effect of air exposure on lanthanum aluminates (LaAlOx) deposited by atomic layer deposition. Fourier transform infrared spectroscopy and thermal desorption spectroscopy of as-deposited LaAlOx showed that H2O is absorbed during air exposure and that the amount of absorbed H2O increases with increasing La atomic percent. C was found to be incorporated already during deposition in the form of carbonates. H2O and CO2 are outgassed during postdeposition annealing in an inert atmosphere. After a 700 °C postdeposition anneal, the LaAlOx becomes resistant against H2O absorption due to film densification. Alternatively, in situ capping of the LaAlOx with a ˜2 nm thin Al2O3 film protects the LaAlOx against H2O absorption, but it also hinders the outgassing of the C contaminants during a postdeposition anneal.

Swerts, J.; Gielis, S.; Vereecke, G.; Hardy, A.; Dewulf, D.; Adelmann, C.; Van Bael, M. K.; Van Elshocht, S.

2011-03-01

173

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

DEFF Research Database (Denmark)

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

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

2012-01-01

174

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

175

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

Energy Technology Data Exchange (ETDEWEB)

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.

1982-11-01

176

Stabilization of hydrogen peroxide used as oxidizing agent in the in-situ leaching of uranium from arkosic sandstone  

International Nuclear Information System (INIS)

H/sub 2/O/sub 2/ was used as oxidizing agent of the insoluble tetravalent uranium into the soluble hexavalent state along with NH/sub 4/HCO/sub 3/as complexing agent in tap water solvent. The study was conducted to look at the possibility of commercial scale in situ leaching of uranium from an underground arkosic sandstone ore deposit. It was found that the peroxide was unstable in the basic tap water solvent as well as in the lixiviants to be used for uranium leaching, especially, in the presence of Ca ions and NH/sub 4/HCO/sub 3/. The rate of dissipation of the oxidizing agent was studied in different media at room temperature for 192 hours with distilled water as a reference medium. The material was stabilized by complexing the different ions / metal catalysts in the lixiviant by EDTA. In the presence of EDTA the stability behaviour of the peroxide became almost identical in the distilled water and tap water lixiviants. (author)

177

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 revein situ aeration. Results reveal that mature sewage sludge compost (SSC) placed in one lysimeter exhibits in principle optimal ambient conditions for methanotrophic bacteria to enhance methane oxidation. Under laboratory conditions the mature compost mitigated CH4 loadings up to 300 l CH4/m2 d. In addition, the compost material provided high air permeability even at 100% water holding capacity (WHC). In contrast, the more cohesive, mineral soil cover was expected to cause a notably uniform distribution of the injected air within the waste layer. Laboratory results also revealed sufficient air permeability of the soil materials (TS-F and SS-Z) placed in lysimeter C. However, at higher compaction density SS-Z became impermeable at 100% WHC. Methane emissions from the reference lysimeter with the smaller substrate cover (12–52 g CH4/m2 d) were significantly higher than fluxes from the other lysimeters (0–19 g CH4/m2 d) during in situ aeration. Regarding water balance, lysimeters covered with compost and compost-sand mixture, showed the lowest leachate rate (18–26% of the precipitation) due to the high water holding capacity and more favourable plant growth conditions compared to the lysimeters with mineral, more cohesive, soil covers (27–45% of the precipitation). On the basis of these results, the authors suggest a layered top cover system using both compost material as well as mineral soil in order to support active low-pressure aeration. Conventional soil materials with lower permeability may be used on top of the landfill body for a more uniform aeration of the waste due to an increased resistance to vertical gas flow. A compost cover may be built on top of the soil cover underlain by a gas distribution layer to improve methane oxidation rates and minimise water infiltration. By planting vegetation with a high transpiration rate, the leachate amount emanating from the landfill could be further minimised. The suggested design may be particularly suitable in combination with intermittent in situ aeration, in the later stage of an aeration measure, or at very small sites and shallow deposits. The top cover system could further regulate water infiltration into the landfill and mitigate residual CH4 emissions, even beyond the time of active aeration.

178

Scattered light particle size counting analysis - a technique for true in situ measurement within gas-particle flows  

Energy Technology Data Exchange (ETDEWEB)

The technique of using scattered-light counting analyzers which dispose of purely optically defined measuring volumes allows, within certain limits, direct measurements to be conducted within a given gas-particle flow (true in situ measurement). The method may, depending on the prevailing conditions, be successfully applied with concentrations of up to 10/sup 5/ particles/cm/sup 3/. The use of this technique presents a variety of advantages, in particular in connection with process-engineering applications. In many cases, sub flow sampling or flow dilution becomes unnecessary. The basic concept and the characteristics of this measuring technique are described along with its calibration, the main sources of error and some applications. (orig.).

Umhauer, H.

1989-05-01

179

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

Energy Technology Data Exchange (ETDEWEB)

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.

Pagels, Joakim

2005-04-01

180

Application of the electrophoretic deposition technique for obtaining Yttria-stabilized zirconia tubes  

International Nuclear Information System (INIS)

The electrophoretic deposition (EPD) is recognized as the most versatile technique for processing particulate materials, due to low cost, deposition in minutes and forming of pieces with complex geometry shapes. In this work an experimental setup for the simultaneous conformation of 16 ceramic tubes by EPD was built. Bimodal submicron Yttria-stabilized zirconia particles were deposited into graphite electrodes, after suitably adjusting the rheological characteristics of the suspension in isopropanol. After graphite burning and YSZ sintering at 1500 deg C, the ceramic tubes were characterized by X-ray diffraction, scanning probe microscope, impedance spectroscopy and electrical response as a function of oxygen content. Small dense one end-closed ceramic tubes, fully stabilized in the cubic phase, were successfully obtained by the EPD technique, showing the ability of that technique for processing large quantities of tubular solid electrolytes with electrical response to different amounts of oxygen according to the Nernst law (author)

181

In Situ Stability of Substrate-Associated Cellulases Studied by DSC  

DEFF Research Database (Denmark)

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.

Borch, Kim; Cruys-Bagger, Nicolaj

2014-01-01

182

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2005-09-26

183

A novel in situ atomic force microscopy imaging technique to probe surface morphological features of starch granules.  

Science.gov (United States)

The application of atomic force microscopy (AFM) for observing iodine complexes in starch has been limited due to limitations including granular sample fixation techniques and possible unintended reactions with embedding materials such as epoxy resins or adhesives. In this paper, a new method is described that employs an optical microscopic technique to ensure that the tip of the AFM is scanning a specified granule without any probe-induced particle movement by the AFM probe motion. The direct sprinkling of samples on a two-sided adhesive tape allows investigations in an in situ environment of the un-embedded starch granule surface and thus provides high-resolution images of granule morphology and phase changes of starches in the presence of humidity and with iodine vapor. These observations demonstrate that this novel in situ AFM imaging technique allows us to visualize the hair-like structures on the surface of granular starches when starches are exposed to iodine vapor under humid environments. This study reveals that the hair-like extensions on the starch granule surfaces are strongly dependent on the organization of the glucan polymers within corn or potato starch. PMID:21402375

Park, Hyuksang; Xu, Song; Seetharaman, Koushik

2011-05-01

184

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)

185

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

OpenAIRE

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...

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

2010-01-01

186

Stable Sensor Network (SSN: A Dynamic Clustering Technique for Maximizing Stability in Wireless Sensor Networks  

Directory of Open Access Journals (Sweden)

Full Text Available Stability is one of the major concerns in advancement of Wireless Sensor Networks (WSN. A number of applications of WSN require guaranteed sensing, coverage and connectivity throughout its operational period. Death of the first node might cause instability in the network. Therefore, all of the sensor nodes in the network must be alive to achieve the goal during that period. One of the major obstacles to ensure these phenomena is unbalanced energy consumption rate. Different techniques have already been proposed to improve energy consumption rate such as clustering, efficient routing, and data aggregation. However, most of them do not consider the balanced energy consumption rate which is required to improve network stability. In this paper, we present a novel technique, Stable Sensor Network (SSN to achieve balanced energy consumption rate using dynamic clustering to guarantee stability in WSN. Our technique is based on LEACH (Low-Energy Adaptive Clustering Hierarchy, which is one of the most widely deployed simple and effective clustering solutions for WSN. We present three heuristics to increase the time before the death of first sensor node in the network. We devise the algorithm of SSN based on those heuristics and also formulate its complete mathematical model. We verify the efficiency of SSN and correctness of the mathematical model by simulation results. Our simulation results show that SSN significantly improves network stability period compared to LEACH and its best variant.

Humayun Kabir

2010-07-01

187

Petroleum hydrocarbon bioremediation: sampling and analytical techniques, in situ treatments and commercial microorganisms currently used  

Energy Technology Data Exchange (ETDEWEB)

The sampling and analytical methods, along with available microorganisms, used for in situ hydrocarbon bioremediation are reviewed. Each treatment method is briefly described and its advantages and limitations pertaining to potential applications are evaluated. Bioremediation provides cost-effective, contaminant- and substrate-specific treatments equally successful in reducing the concentrations of single compounds or mixtures of biodegradable materials. In situ treatments rarely yield undesirable byproducts, but precautions and preliminary baseline tests are always recommended. Sampling methods should adhere to good laboratory and field practices and usually do not require highly trained personnel. Analytical methods vary in sensitivity, cost, duration of sample analysis and personnel training required. Voucher specimens of bacterial strains used in bioremediation exist in various repositories (e.g. ATCC, DSM, etc.) or are commercially available, and are usually covered by patent rights. Each one of these strains may yield spectacular results in vitro for specific target compounds. However, the overall success of such strains in treating a wide range of contaminants in situ remains limited. The reintroduction of indigenous microorganisms isolated from the contaminated site after culturing seems to be a highly effective bioremediation method, especially when microorganism growth is supplemented by oxygen and fertilizers. (orig.)

Korda, A.; Santas, P.; Tenente, A.; Santas, R. [Oiko Technics Inst., Athens (Greece)

1997-12-31

188

Petroleum hydrocarbon bioremediation: sampling and analytical techniques, in situ treatments and commercial microorganisms currently used.  

Science.gov (United States)

The sampling and analytical methods, along with available microorganisms, used for in situ hydrocarbon bioremediation are reviewed. Each treatment method is briefly described and its advantages and limitations pertaining to potential applications are evaluated. Bioremediation provides cost-effective, contaminant- and substrate-specific treatments equally successful in reducing the concentrations of single compounds or mixtures of biodegradable materials. In situ treatments rarely yield undesirable byproducts, but precautions and preliminary baseline tests are always recommended. Sampling methods should adhere to good laboratory and field practices and usually do not require highly trained personnel. Analytical methods vary in sensitivity, cost, duration of sample analysis and personnel training required. Voucher specimens of bacterial strains used in bioremediation exist in various repositories (e.g. ATCC, DSM, etc.) or are commercially available, and are usually covered by patent rights. Each one of these strains may yield spectacular results in vitro for specific target compounds. However, the overall success of such strains in treating a wide range of contaminants in situ remains limited. The reintroduction of indigenous microorganisms isolated from the contaminated site after culturing seems to be a highly effective bioremediation method, especially when microorganism growth is supplemented by oxygen and fertilizers. PMID:9457796

Korda, A; Santas, P; Tenente, A; Santas, R

1997-12-01

189

In situ high-frequency UV-Vis spectrometer probes for investigating runoff processes and end member stability.  

Science.gov (United States)

In recent years, several limitations as to the application of end member mixing analysis with isotope and geochemical tracers have been revealed: unstable end member solutions, inputs varying in space and time, and unrealistic mixing assumptions. In addition, the necessary high-frequency sampling using conventional methods is time and resources consuming, and hence most sampling rates are not suitable for capturing the response times of the majority of observed headwater catchments. However, high-frequency observations are considered fundamental for gaining new insights into hydrological systems. In our study, we have used two portable, in situ, high-frequency UV-Vis spectrometers (spectro::lyser; scan Messtechnik GmbH) to investigate the variability of several signatures in streamflow and end member stability. The spectro::lyser measures TOC, DOC, nitrate and the light absorption spectrum from 220 to 720 nm with 2.5 nm increment. The Weierbach catchment (0.45 km2) in the Attert basin (297 km2) in Luxemburg is a small headwater research catchment (operated by the CRP Gabriel Lippmann), which is completely forested and underlain by schist bedrock. The catchment is equipped with a dense network of hydrological instruments and for this study, the outlet of the Weierbach catchment was equipped with one spectro::lyser, permanently sensing stream water at a 15 minutes time step over several months. Hydrometric and meteorologic data was compared with the high-frequency spectro::lyser time series of TOC, DOC, nitrate and the light absorption spectrum, to get a first insight into the behaviour of the catchment under different environmental conditions. As a preliminary step for a successful end member mixing analysis, the stability of rainfall, soil water, and groundwater was tested with one spectro::lyser, both temporally and spatially. Thereby, we focused on the investigation of changes and patterns of the light absorption spectrum of the different end members and the stream water. Besides using DOC and nitrate for characterizing the end members, our idea is to use the light absorption spectrum as a fingerprint of various constituents of the water. To get a better understanding on how to handle the in situ spectro::lyser, the instrument was compared to conventionally analysed water samples with a special focus on fundamental technical issues: Is there a general difference between in situ and lab measurements and does it make a difference whether the samples are analysed immediately in the field or after days and weeks in the lab and/or again with the spectro::lyser? First results indicate the value of using in situ spectrometers to capture high-frequency variations of hydro-chemistry and end member mixing during runoff events in a small headwater catchment.

Schwab, Michael; Weiler, Markus; Pfister, Laurent; Klaus, Julian

2014-05-01

190

Facile green in situ synthesis of Mg/CuO core/shell nanoenergetic arrays with a superior heat-release property and long-term storage stability.  

Science.gov (United States)

We report a facile green method for the in situ synthesis of Mg/CuO core/shell nanoenergetic arrays on silicon, with Mg nanorods as the core and CuO as the shell. Mg nanorods are first prepared by glancing angle deposition. CuO is then deposited around the Mg nanorods by reactive magnetron sputtering to realize the core/shell structure. Various characterization techniques are used to investigate the prepared Mg/CuO core/shell nanoenergetic arrays, including scanning electron microscopy, transmission electron microscopy, X-ray energy dispersive spectroscopy, X-ray diffraction, and thermal analysis. Uniform mixing and intimate contact between the Mg nanorods and CuO are confirmed from both visual inspection of the morphological images and analyses of the heat-release curves. The nanoenergetic arrays exhibit a low-onset reaction temperature (?300 °C) and high heat of reaction (?3400 J/g). Most importantly, the nanoenergetic arrays possess long-term storage stability resulting from the stable CuO shell. This study provides a potential general strategy for the synthesis of various Mg nanorod-based stable nanoenergetic arrays. PMID:23869818

Zhou, Xiang; Xu, Daguo; Zhang, Qiaobao; Lu, Jian; Zhang, Kaili

2013-08-14

191

Design of top covers supporting aerobic in situ stabilization of old landfills - An experimental simulation in lysimeters  

Energy Technology Data Exchange (ETDEWEB)

Highlights: Black-Right-Pointing-Pointer Tested engineered covers as surrogate to gas extraction during and after in situ aeration. Black-Right-Pointing-Pointer Examined how covers influence gas emissions, water balance and leachate generation. Black-Right-Pointing-Pointer Investigated effect of top covers on air-distribution in waste mass during aeration. Black-Right-Pointing-Pointer We suggest criteria and cover design to meet the demands during and after aeration. Black-Right-Pointing-Pointer 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 Multiplication-Sign 2 Multiplication-Sign 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 CH{sub 4} loadings up to 300 l CH{sub 4}/m{sup 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{sub 4}/m{sup 2} d) were significantly higher than fluxes from the other lysimeters (0-19 g CH{sub 4}/m{sup 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{sub 4} emissions, even beyond the time of active aeration.

Hrad, Marlies [Institute of Waste Management, Department of Water-Atmosphere-Environment, University of Natural Resources and Life Sciences, Muthgasse 107, 1190 Vienna (Austria); Huber-Humer, Marion, E-mail: marion.huber-humer@boku.ac.at [Institute of Waste Management, Department of Water-Atmosphere-Environment, University of Natural Resources and Life Sciences, Muthgasse 107, 1190 Vienna (Austria); Wimmer, Bernhard; Reichenauer, Thomas G. [Health and Environment Department, Environmental Resources and Technologies, AIT Austrian Institute of Technology GmbH, Konrad-Lorenz-Strasse 24, 3430 Tulln (Austria)

2012-12-15

192

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

Science.gov (United States)

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.

Plati, Christina; Georgiou, Panos; Loizos, Andreas

2013-04-01

193

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

194

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.

195

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; Enhance axial balance and simplify end tuners. Experimental verification tests on a scale model will be discussed

196

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

197

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

Directory of Open Access Journals (Sweden)

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.

S. Panda

2007-06-01

198

Field assessment of carboxymethyl cellulose stabilized iron nanoparticles for in situ destruction of chlorinated solvents in source zones.  

Science.gov (United States)

This study pilot-tested carboxymethyl cellulose (CMC) stabilized zero-valent iron (ZVI) nanoparticles (with a trace amount of Pd catalyst) for in situ destruction of chlorinated ethenes such as perchloroethylene (PCE) and trichloroethylene (TCE) and polychlorinated biphenyls (PCBs) that had been in groundwater for decades. The test site was located in a well-characterized secondary source zone of PCBs and chlorinated ethenes. Four test wells were installed along the groundwater flow direction (spaced 5 ft apart), including one injection well (IW), one up-gradient monitoring well (MW-3) and two down-gradient monitoring wells (MW-1 and MW-2). Stabilized nanoparticle suspension was prepared on-site and injected into the 50-ft deep, unconfined aquifer. Approximately 150 gallons of 0.2 g/L Fe-Pd (CMC = 0.1 wt%, Pd/Fe = 0.1 wt%) was gravity-fed through IW-1 over a 4-h period (Injection #1). One month later, another 150 gallons of 1.0 g/L Fe-Pd (CMC = 0.6 wt%, Pd/Fe = 0.1 wt%) was injected into IW-1 at an injection pressure Injection #2). When benchmarked against the tracer, approximately 37.4% and 70.0% of the injected Fe was detected in MW-1 during injection #1 and #2, respectively, confirming the soil mobility of the nanoparticles through the aquifer, and higher mobility of the particles was observed when the injection was performed under higher pressure. Rapid degradation of PCE and TCE was observed in both MW-1 and MW-2 following each injection, with the maximum degradation being observed during the first week of the injections. The chlorinated ethenes concentrations gradually returned to their pre-injection levels after approximately 2 weeks, indicating exhaustion of the ZVI's reducing power. However, the injection of CMC-stabilized nanoparticle and the abiotic reductive dechlorination process appeared to have boosted a long-term in situ biological dechlorination thereafter, which was evidenced by the fact that PCE and TCE concentrations showed further reduction after two weeks. After 596 days from the first injection, the total chlorinated ethenes concentration decreased by about 40% and 61% in MW-1 and MW-2, respectively. No significant long-term reduction of PCB 1242 was observed in MW-1, but a reduction of 87% was evident in MW-2. During the 596 days of testing, the total concentrations of cis-DCE (dichloroethylene) and VC (vinyl chloride) decreased by 20% and 38% in MW-1 and MW-2, respectively. However, the combined fraction of cis-DCE and VC in the total chlorinated ethenes (PCE, TCE, cis-DCE and VC) increased from 73% to 98% and from 62% to 98%, respectively, which supports the notion that biological dechlorination of PCE and TCE was active. It is proposed that CMC-stabilized ZVI-Pd nanoparticles facilitated the early stage rapid abiotic degradation. Over the long run, the existing biological degradation process was boosted with CMC as the carbon source and hydrogen from the abiotic/biotic processes as the electron donor, resulting in the sustained enhanced destruction of the chlorinated organic chlorinated ethenes in the subsurface. PMID:20106501

He, Feng; Zhao, Dongye; Paul, Chris

2010-04-01

199

Characteristics of borehole construction technique of in-situ leaching at low confined water head  

International Nuclear Information System (INIS)

During the test and production of in-situ leaching of sandstone deposit, it is very difficult and complicated to exploit boreholes when confined water head of ore-bearing acquifer is quite low. The pressure of stratum is out of balance because of adding the drilling fluid to borehole. So it is of importance to the borehole construction and completion under the condition of low confined water head to reduce the effect of the drilling fluid on stratum, prevent the drilling fluid leaking, and recover the original permeability of the ore-bearing aquifer by adopting effective flushing methods after borehole completion. (authors)

200

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

Directory of Open Access Journals (Sweden)

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.

Sang Jeen Hong

2013-04-01

201

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

CERN Document Server

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...

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

2010-01-01

202

Residual stress evaluation in brittle coatings using indentation technique combined with in-situ bending  

International Nuclear Information System (INIS)

The indentation crack length approach was adopted and further elaborated to evaluate residual stress and toughness of the brittle coatings: two kinds of glass coatings on steel. The influence of the residual stress on indentation cracking was examined in as-received coating condition and by in-situ superimposing a counteracting tensile stress. For purpose of providing reference toughness values stress-free pieces of separated coating material have also been examined. Thus results of the two complementary sets of experiments were assumed to prove self-consistently toughness and residual stress data of the coating. In particular, the in-situ bending of specimen in combination with the indentation test allowed us to vary deliberately the residual stress situation in glass coating. Thus experiments which utilized the combination of bending test and micro-indentation were introduced as a method to provide unambiguous information about residual compressive stress. Toughness and residual compressive stress of glass coatings used in this study were 0.46-0.50 MPa·m1/2 and 94-111 MPa, respectively. Furthermore, a thermoelastic calculation of the residual compressive stress was performed and it is found that the value of residual compressive stress at coating surface of specimen was 90-102 MPa. (author)

203

The establishment of an in-situ real time radiation contour mapping technique  

International Nuclear Information System (INIS)

The goal of this study is to present that an in-situ radiation dose distribution on an area measured by using a gamma radiation measuring instrument is grasped without a delay. Fundamentally, the test includes an area map as well as real numerical data from the measured area. The map is a computer file with a format of 'bmp' which is used in the gamma radiation measuring instrument, and the data is a text file which has numerical values of the latitude, longitude and radiation dose rates of the measured points. The radiation dose rates of the unmeasured points in the area are displayed through an interpolation with those of the measured ones. A 2D plot shows the contour lines with an overlapped map image and a 3D one gives contour lines on the z-axis for an immediate understanding of the radiation level. It is available to optionally display the numerical values of the radiation dose rates and to zoom up and down the image of a certain part for a detailed view. This contour mapping method programmed by using a commercial software requires only a mouse click to show in-situ in a real time the radiation distribution on the corresponding map in a laptop window screen. (author)

204

‘Expansion in-situ’ concept as a new technique for expanding skin and soft tissue  

OpenAIRE

Techniques for expanding skin and soft tissue are widely used to repair damaged areas since they facilitate the provision of new, additional skin tissue with similar quality, texture and color to that surrounding the defective area. Conventional expansion techniques involve placing expanders under the normal skin adjacent to a lesion. However, these techniques may involve additional incisions, complications with blood supply and ‘dog-ear’ deformities and may result in a low utilization ra...

Fang, Lin; Zhou, Chuande; Yang, Mingyong

2013-01-01

205

Arthroscopic Posterior Stabilization of the Shoulder Using a Percutaneous Knotless Mattress Suture Technique  

OpenAIRE

Posterior shoulder instability is far less common than anterior instability, and its arthroscopic treatment can be technically demanding. We describe a percutaneous arthroscopic technique for posterior shoulder stabilization using mattress sutures and knotless anchors. Spinal needles are used to pass the sutures percutaneously in a mattress fashion. Knotless anchors are used to secure the sutures under the labrum. These anchors can be used without cannulas, giving easier access to the posteri...

Tennent, Duncan; Concina, Chiara; Pearse, Eyiyemi

2014-01-01

206

Stable Sensor Network (SSN): A Dynamic Clustering Technique for Maximizing Stability in Wireless Sensor Networks  

OpenAIRE

Stability is one of the major concerns in advancement of Wireless Sensor Networks (WSN). A number of applications of WSN require guaranteed sensing, coverage and connectivity throughout its operational period. Death of the first node might cause instability in the network. Therefore, all of the sensor nodes in the network must be alive to achieve the goal during that period. One of the major obstacles to ensure these phenomena is unbalanced energy consumption rate. Different techniques have a...

Humayun Kabir; Chowdhury Sayeed Hyder; Alim Al Islam, A. B. M.; Mahmuda Naznin

2010-01-01

207

Dynamic reconstruction based on a Singular Value Decomposition (SVD) technique for BWR stability analysis  

International Nuclear Information System (INIS)

This paper reviews dynamic reconstruction techniques based on a global fit of a given signal by means of orthonormal polynomials. This methodology will be adapted for the analysis of neutronic power signals from BWR reactors to characterize its stability regime. The methodology uses the Singular Value Decomposition (SVD) as main tool for obtaining a low dimensional reconstructed phase space for the system. To check the methodology performance, it is analyzed experimental neutronic power signals from Ringhals 1 BWR. (author). 14 refs., 1 tab

208

Effectiveness of streambank-stabilization techniques along the Kenai River, Alaska  

Science.gov (United States)

The Kenai River in southcentral Alaska is the State's most popular sport fishery and an economically important salmon river that generates as much as $70 million annually. Boatwake-induced streambank erosion and the associated damage to riparian and riverine habitat present a potential threat to this fishery. Bank-stabilization techniques commonly in use along the Kenai River were selected for evaluation of their effectiveness at attenuating boatwakes and retarding streambank erosion. Spruce trees cabled to the bank and biodegradable man-made logs (called 'bio-logs') pinned to the bank were tested because they are commonly used techniques along the river. These two techniques were compared for their ability to reduce wake heights that strike the bank and to reduce erosion of bank material, as well as for the amount and quality of habitat they provide for juvenile chinook salmon. Additionally, an engineered bank-stabilization project was evaluated because this method of bank protection is being encouraged by managers of the river. During a test that included 20 controlled boat passes, the spruce trees and the bio-log provided a similar reduction in boatwake height and bank erosion; however, the spruce trees provided a greater amount of protective habitat than the bio-log. The engineered bank-stabilization project eroded less during nine boat passes and provided more protective cover than the adjacent unprotected natural bank. Features of the bank-stabilization techniques, such as tree limbs and willow plantings that extended into the water from the bank, attenuated the boatwakes, which helped reduce erosion. These features also provided protective cover to juvenile salmon.

Dorava, Joseph M.

1999-01-01

209

Effects and thermal stability of hydrogen microwave plasma treatment on tetrahedral amorphous carbon films by in situ ultraviolet photoelectron spectroscopy  

International Nuclear Information System (INIS)

This paper reports a comprehensive experimental study on the effects of hydrogen microwave plasma treatment on nonhydrogenated high sp3 content tetrahedral amorphous carbon (ta-C) film. In this study, a surface C-H dipole layer was first observed by high resolution electron energy loss spectroscopy, showing the presence of C-H bonding states. This resulted in the enhancement of electron field emission of the plasma treated films by largely lowering the turn-on field. Thermal stability tests using in situ ultraviolet photoelectron spectroscopy confirm that the C-H dipole layer not only reduces the work function of the films, it is extremely stable in both ambient and vacuum conditions and can sustain up to 600 deg. C annealing in vacuum. Atomic force microscopy studies also show minimal modifications to the surface morphology, leading to the conclusion that the C-H dipole layer is responsible for lowering the work function. This has improved the electron emission properties which can lead to potential applications such as electron emission displays.

210

Kinetic stabilization of Fe film on GaAs(100): An in situ x-ray reflectivity Study  

CERN Document Server

We study the growth of the Fe films on GaAs(100) at a low temperature, 140 K, by $in$-$situ$ UHV x-ray reflectivity using synchrotron radiation. We find rough surface with the growth exponent, $\\beta_S$ = 0.51$\\pm$0.04. This indicates that the growth of the Fe film proceeds via the restrictive relaxation due to insufficient thermal diffusion of the adatoms. The XRR curves are nicely fit by a model with a uniform Fe film, implying that the surface segregation and interface alloying of both Ga and As are negligible. When the Fe film is annealed to 300 K, however, the corresponding XRR can be fit only after including an additional layer of 9 A thickness between the Fe film and the substrate, indicating the formation of ultrathin alloy near the interface. The confinement of the alloy near the interface derives from the fact that the diffusion of Ga and As from the substrate should proceed via the inefficient bulk diffusion, and hence the overlying Fe film is kinetically stabilized.

Kim, T C; Kim, Y; Noh, D Y; OH, S J; Kim, J S

2006-01-01

211

Stability analysis of nonlinear Roesser-type two-dimensional systems via a homogenous polynomial technique  

International Nuclear Information System (INIS)

This paper is concerned with the problem of stability analysis of nonlinear Roesser-type two-dimensional (2D) systems. Firstly, the fuzzy modeling method for the usual one-dimensional (1D) systems is extended to the 2D case so that the underlying nonlinear 2D system can be represented by the 2D Takagi—Sugeno (TS) fuzzy model, which is convenient for implementing the stability analysis. Secondly, a new kind of fuzzy Lyapunov function, which is a homogeneous polynomially parameter dependent on fuzzy membership functions, is developed to conceive less conservative stability conditions for the TS Roesser-type 2D system. In the process of stability analysis, the obtained stability conditions approach exactness in the sense of convergence by applying some novel relaxed techniques. Moreover, the obtained result is formulated in the form of linear matrix inequalities, which can be easily solved via standard numerical software. Finally, a numerical example is also given to demonstrate the effectiveness of the proposed approach. (general)

212

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2003-08-01

213

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

Science.gov (United States)

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

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

2012-12-01

214

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

OpenAIRE

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-...

Shadid, Rola Muhammed; Sadaqah, Nasrin Rushdi; Othman, Sahar Abdo

2014-01-01

215

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

Directory of Open Access Journals (Sweden)

Full Text Available 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.

L. Arzubiaga

2014-11-01

216

A novel technique of in situ phase-shift interferometry applied for faint dissolution of bulky montmorillonite in alkaline solution  

International Nuclear Information System (INIS)

The effect of alkaline pH on the dissolution rate of bulky aggregated montmorillonite samples at 23°C was investigated for the first time by using an enhanced phase-shift interferometry technique combined with an internal refraction interferometry method developed for this study. This technique was applied to provide a molecular resolution during the optical observation of the dissolution phenomena in real time and in situ while remaining noninvasive. A theoretical normal resolution limit of this technique was 0.78 nm in water for opaque material, but was limited to 6.6 nm for montmorillonite due to the transparency of the montmorillonite crystal. Normal dissolution velocities as low as 1 × 10-4 to 1 × 10-3 nm/s were obtained directly by using the measured temporal change in height of montmorillonite samples set in a reaction cell. The molar dissolution fluxes of montmorillonite obtained in this study gave considerably faster dissolution rates in comparison to those obtained in previous investigations by solution analysis methods. The pH dependence of montmorillonite dissolution rate determined in this study was qualitatively in good agreement with those reported in the previous investigations. The dissolution rates to be used in safety assessments of geological repositories for radioactive wastes should be obtained for bulky samples. This goal has been difficult to achieve using conventional powder experiment technique and solution analysis method, but has been shown to be feasible using the enhanced phase-shift interferometry. (author)

217

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  

OpenAIRE

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 ...

Pardanaud, C.; Martin, C.; Giacometti, G.; Mellet, N.; Pe?gourie?, B.; Roubin, P.

2015-01-01

218

Preparation of SiC doped In-Situ MgB2 mono- and 7-filamentary wires by continuous tube forming and filling technique  

Science.gov (United States)

Long lengths of in-situ SiC doped MgB2/Fe mono- filamentary wires with high critical current densities and 7- filamentary MgB2/Nb/Cu/Fe wires with better thermal stability have been fabricated by either continuous tube forming & filling (CTFF) technique or combining both powder in tube (PIT) and CTFF process, respectively. Particular efforts were made in view of the optimization of the manufacturing and annealing processes of the wires. The as obtained wires were sintered under a vacuum furnace at different sintering temperatures and the optimized sintering of the MgB2 wires were investigated by the analysis of optical microscope, XRD, SEM, and the transport Jc measurements. The Jc value in a 8 at.% SiC doped MgB2/Fe mono- filamentary wire is more than 104A/cm2 at 4.2 K and a field of 11 T. While in doped 7- filamentary wire, the similar Jc value (104A/cm2) is obtained at 4.2 K and a field of 7.5 T. Moreover, the n factors are determined to be 33 and 10 at 11 T in the mono- and 7- filamentary MgB2wires with SiC doping, respectively, indicating the possibility to use the as fabricated MgB2 wires in the persistent mode for fields from 0.5 T to 10 T at 4.2 K.

Ma, L.; Suo, H. L.; Zhang, Z. L.; Gao, T. Y.; Liu, M.; Zhao, Y.; Zhou, M. L.; Flükiger, R.

2008-02-01

219

Preparation of SiC doped In-Situ MgB2 mono- and 7-filamentary wires by continuous tube forming and filling technique  

International Nuclear Information System (INIS)

Long lengths of in-situ SiC doped MgB2/Fe mono- filamentary wires with high critical current densities and 7- filamentary MgB2/Nb/Cu/Fe wires with better thermal stability have been fabricated by either continuous tube forming and filling (CTFF) technique or combining both powder in tube (PIT) and CTFF process, respectively. Particular efforts were made in view of the optimization of the manufacturing and annealing processes of the wires. The as obtained wires were sintered under a vacuum furnace at different sintering temperatures and the optimized sintering of the MgB2 wires were investigated by the analysis of optical microscope, XRD, SEM, and the transport Jc measurements. The Jc value in a 8 at.% SiC doped MgB2/Fe mono- filamentary wire is more than 104A/cm2 at 4.2 K and a field of 11 T. While in doped 7- filamentary wire, the similar Jc value (104A/cm2) is obtained at 4.2 K and a field of 7.5 T. Moreover, the n factors are determined to be 33 and 10 at 11 T in the mono- and 7- filamentary MgB2wires with SiC doping, respectively, indicating the possibility to use the as fabricated MgB2 wires in the persistent mode for fields from 0.5 T to 10 T at 4.2 K

220

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

Scientific Electronic Library Online (English)

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

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

221

Identification of marker chromosomes by in situ hybridization technique using alpha and "classical" satellite DNA probes with relative chromosomal specificity.  

Science.gov (United States)

Nine additional marker chromosomes in children with mental retardation and congenital malformation were investigated by routine cytogenetic and in situ hybridization techniques. Five metacentric non-satellited markers and four satellited markers of unknown origin were determined by routine and banding staining. To determine the origin of small marker chromosomes a special scheme involving the sequential application of definite alphoid and "classical" satellite DNA probes with the relative chromosome specificity was employed. The probes specific to four groups of definite chromosomes (i) 1, 3, 5, 6, 7, 10, 12, 16, 19; (ii) 2, 4, 8, 9, 13, 14, 15, 18, 20, 21, 22; (iii) 1, 11, 17, X; (iiii) 9, 13, 14, 15, 21, 22, Y and in situ hybridization under low stringency conditions were used at the first stage of experiments. After the preliminary analysis and the determination of possible origin of a marker chromosome from a definite group of chromosomes the probes with a strong chromosome-specificity under high stringency conditions were used. The approach involving the application of the original collection of chromosome-specific DNA probes, including molecular markers to practically all human chromosomes [1, 2], and various conditions of hybridization provides an effective method for detecting unknown markers. Marker chromosomes investigated in this study were derivatives of chromosomes 7, 9 (two cases), 13, 14, 21 (two cases), X and Y. PMID:7974787

Vorsanova, S G; Yurov, Y B; Passarge, I; Schmidt, A; Zerova, T E; Demidova, I A; Buzhiyevskaya, T I

1994-01-01

222

A novel technique for the in situ calibration and measurement of friction with the atomic force microscope  

Science.gov (United States)

Presented here is a novel technique for the in situ calibration and measurement of friction with the atomic force microscope that can be applied simultaneously with the normal force measurement. The method exploits the fact that the cantilever sits at an angle of about 10° to the horizontal, which causes the tip (or probe) to slide horizontally over the substrate as a normal force run is performed. This sliding gives rise to an axial friction force (in the axial direction of the cantilever), which is measured through the difference in the constant compliance slopes of the inward and outward traces. Traditionally, friction is measured through lateral scanning of the substrate, which is time consuming, and requires an ex situ calibration of both the torsional spring constant and the lateral sensitivity of the photodiode detector. The present method requires no calibration other than the normal spring constant and the vertical sensitivity of the detector, which is routinely done in the force analysis. The present protocol can also be applied to preexisting force curves, and, in addition, it provides the means to correct force data for cantilevers with large probes.

Stiernstedt, Johanna; Rutland, Mark W.; Attard, Phil

2005-08-01

223

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

Science.gov (United States)

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.

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

224

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

International Nuclear Information System (INIS)

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

225

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

Science.gov (United States)

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.

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

2008-12-01

226

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

Directory of Open Access Journals (Sweden)

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

C. Zellweger

2012-07-01

227

Evaluation of in situ mechanical properties of composites by using nanoindentation techniques  

International Nuclear Information System (INIS)

The in situ mechanical properties of the fibers, matrices and interfaces in an Al2O3 fiber-reinforced ?-21S Ti alloy have been evaluated by using two nanoscale indentation tests. The Al2O3 fibers were coated with a refractory metal and Y2O3 duplex coating which served as a diffusion barrier during the HIPing used to produce the metal matrix composites. The hardness of the fibers, interfaces and matrix were obtained by performing a series of indentations across the fiber/matrix interface. The hardness decreases from the Al2O3 fiber to the Ti matrix. Additionally, by doing fiber pushout tests, the interfacial shear strength, interfacial frictional stress and mode 2 interfacial fracture energy were obtained. Scanning electron microscopy and X-ray mapping were used for microstructural and chemical analysis. The mechanical properties of the interfaces were related to their chemical composition. The interfacial fracture was found to occur at the interface between the refractory metal and the Y2O3. The mode 2 interfacial fracture energy in this system is more than two orders of magnitude lower than the interfacial fracture energy of Ti/Al2O3 without the diffusion barrier

228

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

Directory of Open Access Journals (Sweden)

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.

Somayeh Bakhshizadeh

2014-04-01

229

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

International Nuclear Information System (INIS)

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.

230

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)

231

Use of noninvasive geophysical techniques for the In Situ Vitrification Program. Volume 1, Literature review: Revision 1  

Energy Technology Data Exchange (ETDEWEB)

In situ vitrification (ISV) is a waste pit remediation technology that can potentially eliminate the need for pit excavation. The ISV program at the Idaho National Engineering Laboratory (INEL) funded this study to evaluate geophysical techniques that might be useful for performing detailed screening of the materials, soil conditions, and local geology of waste pits targeted for remediation. The evaluation focuses on a specific set of characterization objectives developed by ISV engineers. The objectives are based on their assessment of safety, environmental, and cost efficiency issues associated with the ISV process. A literature review of geophysical case histories was conducted and a geophysical survey was performed at the INEL simulated waste pit so that the evaluation could be based on demonstrable results.

Josten, N.E.; Marts, S.T.; Carpenter, G.S.

1991-11-01

232

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1997-10-01

233

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

234

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)

235

Analytical techniques for the in situ quantification and characterization of radioactive decommissioning wastes  

International Nuclear Information System (INIS)

A direct-assay technique quantitatively assays and characterizes the nuclides (including all 10CFR61 nuclides) present in fuel pool stored components. Materials analyzed include control rod blades, LPRMs, flow channels, vacuum filters, and many other miscellaneous components stored underwater. The system, based on advanced gamma-ray spectroscopy scanning techniques, combines scanning with scaling factors, obtaining from direct sample analysis, and dose-rate profiling to give a complete waste analysis that allows accurate and cost effective classification for packaging, shipment, and burial. The methodology (1) improves accuracy by providing direct measurement of the components being shipped, (2) allows a more knowledgable and cost effective packaging of items in a shipping container or cask, and (3) reduces burial costs by allowing less conservative estimates of total Curies shipped in each container. Several recent applications of the methods are presented and the results discussed

236

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)

237

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)

238

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

Science.gov (United States)

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.

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

2014-07-01

239

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

Directory of Open Access Journals (Sweden)

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.

M. F. Schibig

2014-07-01

240

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

Directory of Open Access Journals (Sweden)

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 1.2–1.4 mol of methane per kg porewater at in-situ pressure, which is equivalent to a gas hydrate saturation of 15–18% 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 22–24% 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 C2–C3 and the presence of C5.

K. Heeschen

2011-05-01

241

Demonstration of a stabilized alumina/ethanol colloidal dispersion technique for seeding high temperature air flows  

Science.gov (United States)

Laser anemometry enables the measurement of complex flow fields via the light scattered from small particles entrained in the flow. In the study of turbomachinery, refractory seed materials are required for seeding the flow due to the high temperatures encountered. In this work we present a pH stabilization technique commonly employed in ceramic processing to obtain stable dispersions for generating aerosols of refractory seed material. By adding submicron alumina particles to a preadjusted pH solution of ethanol, a stable dispersion is obtained which when atomized, produces a high quality aerosol. Commercial grade alumina powder is used with a moderate size distribution. Other metal oxide powders in various polar solvents could also be used once the point of zero charge (pH(pzc)) of the powder in the solvent has been determined. Laser anemometry measurements obtained using the new seeding technique are compared to measurements obtained using Polystyrene Latex (PSL) spheres as the seed material.

Wernet, Mark P.; Skoch, Gary J.; Wernet, Judith H.

1995-01-01

242

Intermatrix synthesis: easy technique permitting preparation of polymer-stabilized nanoparticles with desired composition and structure  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract The synthesis of polymer-stabilized nanoparticles (PSNPs can be successfully carried out using intermatrix synthesis (IMS technique, which consists in sequential loading of the functional groups of a polymer with the desired metal ions followed by nanoparticles (NPs formation stage. After each metal-loading-NPs-formation cycle, the functional groups of the polymer appear to be regenerated. This allows for repeating the cycles to increase the NPs content or to obtain NPs with different structures and compositions (e.g. core-shell or core-sandwich. This article reports the results on the further development of the IMS technique. The formation of NPs has been shown to proceed by not only the metal reduction reaction (e.g. Cu0-NPs but also by the precipitation reaction resulting in the IMS of PSNPs of metal salts (e.g. CuS-NPs.

Macanás Jorge

2011-01-01

243

Improving carbon cycle models using inverse modelling techniques with in-situ measurements and satellite observations  

Science.gov (United States)

Improving our understanding of the carbon cycle is an important component of modelling climate and the Earth system, and a variety of inverse modelling techniques have been used to combine process models with different types of observational data. Model data fusion, or inverse modelling, is the process of best combining our under- standing of the dynamics of a system, observations and our prior knowledge of the state of the system. We consider a simple model for the carbon budget allocation for terrestrial ecosystems, the Data Assimilation-Linked Ecosystem model (DALEC). DALEC is a box model simulating a large range of processes occurring at different time scales from days to millennia. Eddy covariance measurements of net ecosystem exchange of CO2 have been used intensively for over a decade to confront DALEC with real data to estimate model parameters and quantify uncertainty of the model predictions. The REgional FLux Estimation eXperiment (REFLEX), compared the strengths and weaknesses of various inverse modelling strategies (MCMC, ENKF) to estimate parameters and initial stocks for DALEC; most results agreed on the fact that parameters and initial stocks directly related to fast processes were best estimated with narrow confidence intervals, whereas those related to slow processes were poorly estimated with very large uncertainties. While other studies have tried to overcome this difficulty by adding complementary data streams or by considering longer observation windows no systematic analysis has been carried out so far to explain the large differences among results of REFLEX. One of the merits of DALEC is its simplicity that facilitates close mathematical scrutiny. Using variational techniques we quantify the ill-posedness of the inverse problem and we discuss various regularisation techniques. Using the tangent linear model we study the information content of multiple data sources and show how these multiple data sources help constraining initial carbon stocks and parameters.

Delahaies, Sylvain; Roulstone, Ian; Nichols, Nancy

2014-05-01

244

Tribo-electrochemical surface modification of tantalum using in situ AFM techniques.  

Science.gov (United States)

A scanning-probe-based technique to observe tribo-electrochemically stimulated surface was demonstrated. The configuration consists of an electrochemical cell attached to an atomic force microscope (AFM) scanner. Under an applied electrical potential and in various chemical environments, the surface morphology, roughness, skew, bearing ratio, as well as surface adhesive forces between probes were measured, and the effects of mechano-electrochemical stimuli were evaluated. The effects of mechanical, electrochemical, and mechano-electrochemical stimuli were found to compete during AFM sliding process. Their effects do not follow a linear relationship, implying that the mechanical stimulus promotes electrochemical reactions. Similarly, electrochemically enhanced mechanical removal of surface materials is possible. PMID:20853404

Huitink, David; Gao, Feng; Liang, Hong

2010-01-01

245

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

International Nuclear Information System (INIS)

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)

246

Effect of meniscus replacement fixation technique on restoration of knee contact mechanics and stability.  

Science.gov (United States)

The menisci are important biomechanical components of the knee. We developed and validated a finite element model of meniscal replacement to assess the effect of surgical fixation technique on contact behavior and knee stability. The geometry of femoral and tibial articular cartilage and menisci was segmented from magnetic resonance images of a normal cadaver knee using MIMICS (Materialise, Leuven, Belgium). A finite element mesh was generated using HyperWorks (Altair Inc, Santa Ana, CA). A finite element solver (Abaqus v6.9, Simulia, Providence, RI) was used to compute contact area and stresses under axial loading and to assess stability (reaction force generated during anteroposterior translation of the femur). The natural and surgical attachments of the meniscal horns and peripheral rim were simulated using springs. After total meniscectomy, femoral contact area decreased by 26% with a concomitant increase in average contact stresses (36%) and peak contact stresses (33%). Replacing the meniscus without suturing the horns did little to restore femoral contact area. Suturing the horns increased contact area and reduced peak contact stresses. Increasing suture stiffness correlated with increased meniscal contact stresses as a greater proportion of tibiofemoral load was transferred to the meniscus. A small incremental benefit was seen of simulated bone plug fixation over the suture construct with the highest stiffness (50 N/mm). Suturing the rim did little to change contact conditions. The nominal anteroposterior stiffness reduced by 3.1 N/mm after meniscectomy. In contrast to contact area and stress, stiffness of the horn fixation sutures had a smaller effect on anteroposterior stability. On the other hand suturing the rim of the meniscus affected anteroposterior stability to a much larger degree. This model emphasizes the importance of the meniscus in knee biomechanics. Appropriate meniscal replacement fixation techniques are likely to be critical to the clinical success of meniscal replacement. While contact conditions are mainly sensitive to meniscus horn fixation, the stability of the knee under anteroposterior shear loads appeared to be more sensitive to meniscal rim fixation. This model may also be useful in predicting the effect of biomaterial mechanical properties and meniscal replacement shape on knee contact conditions. PMID:21608413

D'Lima, D D; Chen, P C; Kessler, O; Hoenecke, H R; Colwell, C W

2011-06-01

247

Analytical techniques for the in-situ quantification of low-level waste  

International Nuclear Information System (INIS)

A direct-assay technique quantitatively assays and characterizes the nuclides (including all 10CFR61 Table I and Table II nuclides) present in bulk radioactive wastes. Materials analyzed can include resins and sludges in transfer lines, tanks and liners, barreled oily wastes and DAW, and components stored in fuel pools. The methodology applies to a range of samples from high-activity resins and control-rod blades to slightly contaminated DAW. The system, based on advanced gamma-ray spectroscopy scanning techniques, combines scanning with sample analysis results and correlation methodology to give a complete waste analysis that allows efficient, accurate and cost effective classification for packaging, shipment and burial. The methodology can (1) improve accuracy by averaging over an entire container rather than depending upon a single small sample from the usually inhomogeneous waste, (2) reduce accumulated man-rem exposure where highly radioactive wastes must be sampled and analyzed, (3) allow a more knowledgeable and cost effective choice of shipping container and cask, and (4) reduce burial costs by allowing less conservative estimates of total curies shipped in each container. Several recent applications of the methods are presented and the results discussed. 14 refs., 7 figs., 3 tabs

248

Advancing In Situ Modeling of ICMEs: New Techniques for New Observations  

CERN Document Server

It is generally known that multi-spacecraft observations of interplanetary coronal mass ejections (ICMEs) more clearly reveal their three-dimensional structure than do observations made by a single spacecraft. The launch of the STEREO twin observatories in October 2006 has greatly increased the number of multipoint studies of ICMEs in the literature, but this field is still in its infancy. To date, most studies continue to use on flux rope models that rely on single track observations through a vast, multi-faceted structure, which oversimplifies the problem and often hinders interpretation of the large-scale geometry, especially for cases in which one spacecraft observes a flux rope, while another does not. In order to tackle these complex problems, new modeling techniques are required. We describe these new techniques and analyze two ICMEs observed at the twin STEREO spacecraft on 22-23 May 2007, when the spacecraft were separated by ~8 degrees. We find a combination of non-force-free flux rope multi-spacecr...

Mulligan, Tamitha; Lynch, Benjamin J

2012-01-01

249

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

Science.gov (United States)

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

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

2012-12-01

250

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

Science.gov (United States)

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.

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

2015-01-01

251

Determination of stability derivatives from flight data using a Newton-Raphson minimization technique  

Science.gov (United States)

A modified Newton-Raphson or quasilinearization minimization technique for determining stability derivatives from flight data was developed and compared with simple-equations, analog-matching, least-squares, and Shinbrot methods of analysis. For the data analyzed, the solutions computed by using the estimates obtained from the Newton-Raphson technique fit the data and determined coefficients adequately. A further modification to include a priori information was found to be useful. A model statistically similar to the flight data was analyzed using the same methods (excluding analog matching), and the Newton-Raphson technique was found to yield superior estimates. An approximate Cramer-Rao bound was compared with the error covariance matrix of the model and was found to provide information about the reliability of the individual estimates obtained. The technique was successfully applied to data obtained from a light airplane, a large supersonic airplane, and a lifting body vehicle. It was shown that the reliability of the estimates of a given coefficient obtained from these vehicles depends upon the data analyzed.

Iliff, K. W.; Taylor, L. W., Jr.

1972-01-01

252

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

Directory of Open Access Journals (Sweden)

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.

W. Reid

2012-11-01

253

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

254

In situ observation of ductile fracture using X-ray tomography technique  

International Nuclear Information System (INIS)

Fast microtomography combined with local crack driving force analysis has been employed to analyze crack-tip stress/strain singularities in an aluminum alloy. The application of fast microtomography has made it possible to observe real crack initiation and propagation behaviors without intermediate unloading. The details of a crack and its local propagation behaviors are readily observed with this technique along with evidence of microstructure/crack interactions. After a preliminary investigation of the achieved spatial resolution, we show that conventional stationary and growing crack singularities can be quantitatively validated by deriving the local crack opening displacement. This is to our knowledge the first three-dimensional validation of conventional fracture mechanics during a real time continuous experiment that has been mainly developed via surface observations so far. We also reveal that there is a spatial transition from a stationary crack singularity to a growing crack singularity in addition to the well-known temporal transition that occurs with the onset of crack propagation. Local crack propagation behaviors are also discussed on the basis of this validation. To separate the effects of complex crack geometry from those of microstructure, we also perform an image-based numerical simulation.

255

In-Situ Measurement of Internal Temperature Distribution of Sintered Materials Using Ultrasonic Technique  

International Nuclear Information System (INIS)

It is often required to measure internal temperature distribution of a heated material because it is closely related to the materials properties and behavior. In this work, an effective ultrasonic method has been applied to the monitoring of internal temperature distributions of an alumina being heated. The principle of the method is based on the temperature dependence of the velocity of ultrasound propagating through a heated material. In the method, a combined technique of ultrasonic pulse-echo measurements and a finite difference calculation is employed to determine the one-dimensional temperature distribution in a heated material. Shear wave is used for the ultrasonic measurements to improve the accuracy in determining temperature. To verify the feasibility of the method, pulse-echo measurements with a shear wave transducer have been performed for an alumina rod of 14 mm diameter and 25 mm length whose single-end is being heated. The internal temperature distribution and its variation of the alumina are then measured during the heating. The temperature distributions determined by the ultrasonic method almost agree with those obtained by an infrared method. Thus, it is demonstrated that the ultrasonic method has the potential for in-process monitoring of the transient temperature variation of ceramics being processed at high temperatures.

256

In-Situ Measurement of Internal Temperature Distribution of Sintered Materials Using Ultrasonic Technique  

Science.gov (United States)

It is often required to measure internal temperature distribution of a heated material because it is closely related to the materials properties and behavior. In this work, an effective ultrasonic method has been applied to the monitoring of internal temperature distributions of an alumina being heated. The principle of the method is based on the temperature dependence of the velocity of ultrasound propagating through a heated material. In the method, a combined technique of ultrasonic pulse-echo measurements and a finite difference calculation is employed to determine the one-dimensional temperature distribution in a heated material. Shear wave is used for the ultrasonic measurements to improve the accuracy in determining temperature. To verify the feasibility of the method, pulse-echo measurements with a shear wave transducer have been performed for an alumina rod of 14 mm diameter and 25 mm length whose single-end is being heated. The internal temperature distribution and its variation of the alumina are then measured during the heating. The temperature distributions determined by the ultrasonic method almost agree with those obtained by an infrared method. Thus, it is demonstrated that the ultrasonic method has the potential for in-process monitoring of the transient temperature variation of ceramics being processed at high temperatures.

Ihara, I.; Tomomatsu, T.

2011-03-01

257

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 obsessment (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)

258

Trace Metals in Groundwater & Vadose Zone Calcite: In Situ Containment & Stabilization of 90Strontium & Other Divalent Metals & Radionuclides at Arid West DOE Sites  

Energy Technology Data Exchange (ETDEWEB)

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

Smith, Robert W.; Fujita, Yoshiko; Ferris, F. Grant; Cosgrove, Donna M.; Colwell, Rick S.

2004-06-01

259

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

International Nuclear Information System (INIS)

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

260

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

International Nuclear Information System (INIS)

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

261

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 preselocity 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)

262

Characteristics of Four Plant Species Used for Soil Bioengineering Techniques in River Bank Stabilization  

Science.gov (United States)

Use the potential values of soil bioengineering techniques are important for the wide attention river ecological restoration works in Beijing. At first, demand for basic knowledge of the technical and biological properties of plants is essential for development of such techniques. Species for each chosen plant material type should be selected with an emphasis on the following: suitability for anticipated environment conditions, reasonable availability in desired quantity and probability of successful establishment. Account on these criteria, four species which used as live staking and rooted cutting techniques were selected, namely, Salix X aureo-pendula, Salix cheilophila, Vitex negundo var. heterophylla and Amorpha fruticosa L.. And monitoring work was performed on three construction sites of Beijing. Various survival rates and morphological parameters data were collected. Concerning plants hydraulic and hydrological behavior, bending tests were used to analysis the flexibility of each plant species. The results from rate and morphological parameters monitoring show that: Salix cheilophila performed the best. Other three plants behaved satisfactorily in shoots or roots development respectively. In the bending test mornitoring, Salix cheilophila branch had the least broken number. Then were Salix X aureo-pendula and Amorpha fruticosa L.. Vitex negundo var. branch had the highest broken number, but it tolerated the highest amount of stress. All plant species should be considered in the future scientific research and construction works in Beijing. Keywords: River bank stabilization, live staking, rooted cutting

Liu, Y.; Gao, J. R.; Lou, H. P.; Zhang, J. R.; Rauch, H. P.

2010-05-01

263

Following the Formation of Active Co(III) Sites in Cobalt Substituted Aluminophosphates Catalysts by In-Situ Combined UV-VIS/XAFS/XRD Technique  

International Nuclear Information System (INIS)

Cobalt substituted aluminophosphates, CoAlPO-34 (Chabazite structure) and DAF-8 (Phillipsite structure) were investigated by in situ combined XRD/EXAFS/UV-VIS technique. In-situ combined XRD, Co K-edge EXAFS and UV-Vis measurements carried out during the calcination process reveal that CoAlPO-34 containing 10 wt percent cobalt is stable and the cobalt ions are converted from Co(II) in the as synthesised form to Co(III); DAF-8 containing about 25 percent cobalt is not stable and does not show change in oxidation state

264

Utilization of fluorescence in situ hybridization (FISH) technique for detection of radiation-induced translocations in atomic bomb survivors  

International Nuclear Information System (INIS)

This paper summarizes recent progress in a collaborative study by Radiation Effects Research Foundation, Hiroshima, Lawrence Livermore National Laboratory and university of California, San Francisco, to investigate the utility of fluorescence in situ hybridization (FISH) with whole-chromosome probes (chromosomes 1, 2 and 4) for measurement of the frequencies of chromosomal translocations that have persisted for decades in the peripheral blood lymphocytes of A-bomb survivors. The frequencies of radiation-induced translocations measured between FISH and G-band/conventional stains for 33 Hiroshima a-bomb survivors (7 distally and 26 proximally exposed survivors with estimated DS86 bone marrow dose ranging from 0-3.0 Sv). Findings showed that, except for a few discrepant cases, translocation frequencies from the same survivors agree reasonably well between FISH and G-banding, provides the assumption that the number of breaks involved in the radiation-induced translocations increases linearly with chromosomal dna content. Present findings have validated that the FISH technique is a useful biological assay system for rapid and accurate detection of persistent translocations for quantification of previous exposures to ionizing radiation. (author). 9 refs

265

In situ mRNA hybridization technique for analysis of metastasis-related genes in human colon carcinoma cells.  

Science.gov (United States)

The purpose of this study was to determine whether the expression level of several genes that regulate different steps of the metastatic process correlates with the metastatic potential of human colon carcinoma cells. The mRNA expression level for epidermal growth factor receptor (growth), basic fibroblast growth factor and interleukin-8 (angiogenesis), type IV collagenase (invasion), E-cadherin and carcinoembryonic antigen (adhesion), and the multidrug resistance gene mdr-1 (drug resistance) in the human KM12 colon carcinoma cell lines and clones with different metastatic potential was measured by Northern blot analysis and by in situ hybridization technique. Highly metastatic KM12SM and KM1214 cells growing in culture uniformly expressed high levels of epidermal growth factor receptor, basic fibroblast growth factor, and carcinoembryonic antigen mRNA, whereas cultures of low metastatic KM12C, clone 1, clone 3, and clone 6 cells displayed heterogeneous patterns of expression. KM12C (low metastatic) and KM12SM (highly metastatic) cells were implanted into the subcutis (ectopic) or the wall of the cecum (orthotopic) of nude mice. The mRNA expression level for epidermal growth factor receptor, basic fibroblast growth factor, interleukin-8, type IV collagenase, carcinoembryonic antigen, and mdr-1 was increased in the cecal wall tumors as compared with subcutaneous tumors or in vitro cultures. These data demonstrate a direct correlation between constitutive and inducible expression of several metastasis-related genes and the metastatic potential of human colon carcinoma cells. PMID:7485388

Kitadai, Y; Bucana, C D; Ellis, L M; Anzai, H; Tahara, E; Fidler, I J

1995-11-01

266

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

267

Laser-induced thermotherapy: an in-situ ablation technique for the local treatment of irresectable colorectal liver metastases  

Science.gov (United States)

Laser-induced thermotherapy (LITT) is a so called in-situ- ablation technique which is used for the treatment of liver tumors. Coagulation necrosis is induced by transmitting the laser irradiation via quartz fibers directly into the tumor tissue. LITT represents similarly to surgical liver resection a local treatment form for liver metastases. The Nd-YAG laser (1064 nm) was used. The application system was placed percutaneously under open MRI control. On-line monitoring was done with MRI for evaluation of the postoperative follow-up we performed MRI-controls every 3 months. A total of 20 patients were treated. Due to the irradiation plan performed preoperatively, the treated tumors could be completely ablated by hyperthermia in all procedures. Complications were pleural effusion in 7 patients and a bile fistula and subcapsulary liver hematoma in one patient each. Local control of tumor growth can be achieved in tumors having undergone complete hyperthermic ablation. An assessment of the method regarding a prognostic benefit is not yet possible due to the short follow-up period and the small patient population.

Ritz, Joerg-Peter; Isbert, Christoph M.; Roggan, Andre; Wacker, Frank; Buhr, Heinz-Johannes; Germer, Christoph-Thomas

2000-11-01

268

Mesospheric aerosol particles studied with in situ techniques. An overview of results from the ECOMA-project  

International Nuclear Information System (INIS)

Complete text of publication follows. A total of six sounding rockets were launched during three field campaigns in the years 2006, 2007, and 2008 from the North-Norwegian Andoya Rocket Range to study the Existence and Charge state Of Meteoric smoke in the middle Atmosphere (ECOMA) and its relation to mesospheric ice particles. A new particle detector was successfully developed which combines the conventional technique of a Faraday-Cup with the active photo ionization of particles and subsequent detection of corresponding photo electrons. In this paper we will give an overview of results from these rocket campaigns. Some noteworthy findings are the experimental verification of meteor smoke existence throughout the entire mesosphere, the first direct in situ measurement of mesospheric ice volume, and new insights into the charging properties of meteoric smoke under the conditions of polar summer. Finally we will also present implications of our results for the understanding of the seasonal variation of meteoric smoke, and we close with a discussion of the significance of our findings for the issue of ice particle nucleation in the polar summer mesopause region.

269

Advanced kinetics for calorimetric techniques and thermal stability screening of sulfide minerals  

International Nuclear Information System (INIS)

Thermal methods of analysis such as differential scanning calorimetry (DSC) provide a powerful methodology for the study of solid reactions. This paper proposes an improved thermal analysis methodology for thermal stability investigation of complex solid-state reactions. The proposed methodology is based on differential iso-conversional approach and involves peak separation, individual peak analysis and combination of isothermal/non-isothermal DSC measurements for kinetic analysis and prediction. The proposed thermal analysis, which coupled with Mineral Libration Analyzer (MLA) technique was employed to investigate thermal behavior of sulfide mineral oxidation. The importance of various experimental variables such as particle size, heating rate and atmosphere were investigated and discussed. The information gained from such an advanced thermal analysis method is useful for scale-up processes with potential of significant savings in plant operations, as well as in mitigating adverse environmental and safety issues arising from handling and storage of sulfide minerals.

270

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

Energy Technology Data Exchange (ETDEWEB)

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)

Behringer, K.; Hennig, D

2002-11-01

271

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)

272

A novel method for in Situ detection of hydrolyzable casein fragments in a cheese matrix by antibody phage display technique and CLSM  

DEFF Research Database (Denmark)

A novel method to monitor in situ hydrolyzable casein fragments during cheese ripening by using immunofluorescent labeling and confocal laser scanning microscopy (CLSM) was developed. Monoclonal single chain variable fragments of antibody (scFvs) were generated by antibody phage display toward three small synthetic peptides of the alpha(s1)-casein sequence. These peptides traverse enzymatic cleavage sites of casein during cheese ripening. The specificity of the generated anti-peptide antibodies was determined by ELISA and Western blot. Finally, an immunofluorescent labeling protocol was successfully developed for the detection of scFvs binding to different alpha(s1)-casein fragments inside a cheese matrix by CLSM. To our knowledge, this is the first demonstrated immunofluorescent labeling method for in situ analysis of proteolysis phenomena in the cheese matrix. Additionally, this technique offers a high potential to study in situ dynamic spatial changes of target components in complex food systems.

Duan, Zhi; Brüggemann, Dagmar Adeline

2009-01-01

273

In-Situ Characterization of Tissue Blood Flow, Blood Content, and Water State Using New Techniques in Magnetic Resonance Imaging.  

Science.gov (United States)

Tissue blood flow, blood content, and water state have been characterized in-situ with new nuclear magnetic resonance imaging techniques. The sensitivities of standard techniques to the physiologic tissue parameters spin density (N_{rm r}) and relaxation times (T_1 and T_2 ) are mathematically defined. A new driven inversion method is developed so that tissue T_1 and T_2 changes produce cooperative intensity changes, yielding high contrast, high signal to noise, and sensitivity to a wider range of tissue parameters. The actual tissue parameters were imaged by automated collection of multiple-echo data having multiple T _1 dependence. Data are simultaneously fit by three-parameters to a closed-form expression, producing lower inter-parameter correlation and parameter noise than in separate T_1 or T_2 methods or pre-averaged methods. Accurate parameters are obtained at different field strengths. Parametric images of pathology demonstrate high sensitivity to tissue heterogeneity, and water content is determined in many tissues. Erythrocytes were paramagnetically labeled to study blood content and relaxation mechanisms. Liver and spleen relaxation were enhanced following 10% exchange of animal blood volumes. Rapid water exchange between intracellular and extracellular compartments was validated. Erythrocytes occupied 12.5% of renal cortex volume, and blood content was uniform in the liver, spleen and kidney. The magnitude and direction of flow velocity was then imaged. To eliminate directional artifacts, a bipolar gradient technique sensitized to flow in different directions was developed. Phase angle was reconstructed instead of intensity since the former has a 2pi -fold higher dynamic range. Images of flow through curves demonstrated secondary flow with a centrifugally-biased laminar profile and stationary velocity peaks along the curvature. Portal vein flow velocities were diminished or reversed in cirrhosis. Image artifacts have been characterized and removed. The foldover in magnified images was eliminated by exciting limited regions with orthogonal pi/2 and pi pulses. Off-midline regions were imaged by tandemly offsetting the phase-encoding and excitation. Artifacts due to non-steady-state conditions were demonstrated. The approach to steady state was defined by operators and vectors, and any repeated series of RF pulses was proven to produce a steady-state. The vector difference between the magnetization and its steady state value is relatively constant during the approach. The repetition time relative to T_1 is the main determinant of approach rate, and off-resonant RF pulses incoherent with the magnetization produce a more rapid approach than on-resonant pulses.

Conturo, Thomas Edward

274

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

DEFF Research Database (Denmark)

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.

Horn, Anna Frisenfeldt; Nielsen, Nina Skall

275

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

DEFF Research Database (Denmark)

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.

Horn, Anna Frisenfeldt; Nielsen, Nina Skall

276

Self-Tuning Power System Stabilizer Design Based on Pole-Assignment and Pole-Shifting Techniques  

Directory of Open Access Journals (Sweden)

Full Text Available In order to improve dynamic stability of the power systems, the use of Power System Stabilizer (PSS has been recently increased. For this purpose, there are varieties of methods for determining the controller coefficients of the system stabilizers. If these coefficients are tuned in each operational point by an adaptive mechanism, the robust performance of the system is improved. In this study, a new method for determining the coefficients of a self-tuning PSS with lead-lag controller based on pole-assignment and pole-shifting techniques is presented. In the design procedure, the required identification in self-tuning regulator is performed by using active and reactive power values. Moreover, the properties of the proposed methodology are compared with self-tuning PID stabilizer whose coefficients are determined by using pole assignment technique. Then, the advantages of the proposed stabilizer in which parameter adaptation is accomplished based on the proposed self-tuning method by combining the pole-assignment and pole-shifting techniques, is expressed with respect to other stabilizers. Finally, in order to show the effectiveness of the proposed methodology, some simulation results on a power system with definite parameters and different operational points are provided and compared by using ITAE performance index which denotes the integral of time multiplied by absolute error.

M. Ataei

2008-01-01

277

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

Scientific Electronic Library Online (English)

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

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

1011-10-01

278

Intrinsic mixing behavior of superconducting NbTiN hot electron bolometer mixers based on in situ technique  

International Nuclear Information System (INIS)

Highlights: ? We present the measured and simulated results for 0.8 and 1.5 THz waveguide NbTiN HEB mixers. ? The measured and calculated current–voltage curves are in good agreement. ? The modeled intrinsic mixer noise temperature has slight difference from the measured results. ? The calculated and measured results show the two cooling mechanism work together. -- Abstract: In this paper, we present the comparison of measured and simulated results for 0.8 and 1.5 THz waveguide NbTiN HEB mixers fabricated by in situ technique, with a relatively thick NbTiN film (10.8 nm). The dimension of NbTiN HEB mixers are 1–1.5 ?m in width and 0.15–0.2 ?m in length respectively. The lowest receiver noise temperature is measured to be as low as 410 K and reduced to 210 K after the correction of the losses of quasi-optical path and IF amplifier chain at both 0.8 and 1.5 THz. We adopt an optimized hot spot model to simulate the DC and RF behaviors of the NbTiN HEB mixer by combining phonon-cooling and diffusion-cooling mechanisms together. The measured and calculated current–voltage curves are in good agreement. The modeled lowest intrinsic mixer noise temperature are 85 and 100 K at 0.8 and 1.5 THz respectively, which are smaller than the measured results by factor of about 2 times. The IF gain bandwidth are observed to be quite sensitive to the microbridge length, with 2.5 GHz for 0.15-?m long device down to 1.9 GHz for 0.2-?m length. The calculated and measured results show the two cooling mechanism work together to improve the performance of the waveguide NbTiN HEB mixers

279

Gas Membrane Sensor Technique for in-situ Downhole Detection of Gases Applied During Geological Storage of CO2  

Science.gov (United States)

The geological storage of CO2 in deep saline aquifers is regarded as a possible technology for the reduction of anthropogenic greenhouse gases. However, comprehensive research is still needed to better understand the behaviour of CO2 during and after storage. Therefore, we developed and applied a new, innovative geochemical monitoring tool for the real time and in-situ determination of CO2 and other gases in the underground and in bore holes. The method uses a phase separating silicone membrane, permeable for gases, in order to separate gases dissolved in borehole fluids, water and brines. Argon is used as a carrier gas to conduct the collected gases through capillaries to the surface. Here, the gas phase is analyzed in real-time with a portable mass spectrometer for all permanent gases. In addition, gas samples may be collected for detailed investigations in the laboratory. Downhole extraction and on-line determination of gases dissolved in brines using this gas membrane sensor (GMS) technique was successful applied at the scientific CO2SINK test site in Ketzin, Germany (sandstone aquifer). GMSs together with temperature and pressure probes were installed in two approx. 700m deep observation holes, drilled in 50m and 100m distance from the CO2 injection well. Hydraulic pressure in the observation wells rose gradually during injection of CO2. Increasing reservoir gas concentrations of helium, hydrogen, methane, and nitrogen as well as the arrival of the added krypton tracer were determined shortly before the injected CO2 appeared. The breakthrough of CO2 into the observation well, in 50m distance, was recorded after 531.5 tons of CO2 were injected.

Zimmer, M.; Erzinger, J.; Kujawa, C.; Group, C.

2008-12-01

280

A Systematic Review of Biochar Research, with a Focus on Its Stability in situ and Its Promise as a Climate Mitigation Strategy  

Science.gov (United States)

Background Claims about the environmental benefits of charring biomass and applying the resulting “biochar” to soil are impressive. If true, they could influence land management worldwide. Alleged benefits include increased crop yields, soil fertility, and water-holding capacity; the most widely discussed idea is that applying biochar to soil will mitigate climate change. This claim rests on the assumption that biochar persists for hundreds or thousands of years, thus storing carbon that would otherwise decompose. We conducted a systematic review to quantify research effort directed toward ten aspects of biochar and closely evaluated the literature concerning biochar's stability. Findings We identified 311 peer-reviewed research articles published through 2011. We found very few field studies that addressed biochar's influence on several ecosystem processes: one on soil nutrient loss, one on soil contaminants, six concerning non-CO2 greenhouse gas (GHG) fluxes (some of which fail to support claims that biochar decreases non-CO2 GHG fluxes), and 16–19 on plants and soil properties. Of 74 studies related to biochar stability, transport or fate in soil, only seven estimated biochar decomposition rates in situ, with mean residence times ranging from 8 to almost 4,000 years. Conclusions Our review shows there are not enough data to draw conclusions about how biochar production and application affect whole-system GHG budgets. Wide-ranging estimates of a key variable, biochar stability in situ, likely result from diverse environmental conditions, feedstocks, and study designs. There are even fewer data about the extent to which biochar stimulates decomposition of soil organic matter or affects non-CO2 GHG emissions. Identifying conditions where biochar amendments yield favorable GHG budgets requires a systematic field research program. Finally, evaluating biochar's suitability as a climate mitigation strategy requires comparing its effects with alternative uses of biomass and considering GHG budgets over both long and short time scales. PMID:24098746

Gurwick, Noel P.; Moore, Lisa A.; Kelly, Charlene; Elias, Patricia

2013-01-01

281

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

OpenAIRE

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...

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

1986-01-01

282

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

OpenAIRE

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 ...

Jeevanandham Arumugam; Thanushkodi Gowder Keppana

2009-01-01

283

Detection of distribution of avian influenza H5N1 virus by immunohistochemistry, chromogenic in situ hybridization and real-time PCR techniques in experimentally infected chickens.  

Science.gov (United States)

Ten specific pathogen free (SPF) chickens were inoculated intranasally with avian influenza virus subtype H5N1. Evaluation revealed distribution of the virus in twelve organs: liver, intestine, bursa, lung, trachea, thymus, heart, pancreas, brain, spleen, kidney, and esophagus. Immunohistochemistry (IHC), chromogenic in situ hybridization (CISH), and real-time polymerase chain reaction (PCR) were developed and compared for detection of the virus from the organs. The distribution of avian influenza H5N1 in chickens varied by animal and detecting technique. The heart, kidneys, intestines, lungs, and pancreas were positive with all three techniques, while the others varied by techique. The three techniques can be used to detect avian influenza effectively, but the pros and cons of each technique need to be determined. The decision of which technique to use depends on the objective of the examination, budget, type and quality of samples, laboratory facilities and technician skills. PMID:21710850

Chamnanpood, Chanpen; Sanguansermsri, Donruedee; Pongcharoen, Sutatip; Sanguansermsri, Phanchana

2011-03-01

284

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

OpenAIRE

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...

Bayatkouhsar et al.

2012-01-01

285

Transient Stability Ranking Technique based on System Parameter Estimation and Extended Equal-Area Criterion  

Science.gov (United States)

The on-line TSC (Transient Stability Control) system is the world's first online-type stabilization system for electric power systems, which realizes optimum stabilized control of moment-by-moment power system conditions by obtaining power system information online and carrying out stability calculations at certain intervals. This paper discusses the new transient stability ranking method for severity of each contingency, which will be introduced to the new on-line TSC system of Chubu Electric Power Company. The ranking method is based on system parameter estimation and the Extended Equal Area Criterion. The method can be applied to unbalanced fault.

Takeuchi, Akira; Sato, Takashi; Takafuji, Kouya; Nishiiri, Hideaki; Takasaki, Kotaro; Hara, Yuji

286

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

287

Dynamic Clustering with Relay Nodes (DCRN: A Clustering Technique to Maximize Stability in Wireless Sensor Networks with Relay Nodes  

Directory of Open Access Journals (Sweden)

Full Text Available With the growing popularity of wireless sensor networks, network stability has become a key area of current research. Different applications of wireless sensor networks demand stable sensing, coverage, and connectivity throughout their operational periods. In some cases, the death of just a single sensor node might disrupt the stability of the entire network. Therefore, a number of techniques have been proposed to improve the network stability. Clustering is one of the most commonly used techniques in this regard. Most clustering techniques assume the presence of high power sensor nodes called relay nodes and implicitly assume that these relay nodes serve as cluster heads in the network. This assumption may lead to faulty network behavior when any of the relay nodes becomes unavailable to its followers. Moreover, relay node based clustering techniques do not address the heterogeneity of sensor nodes in terms of their residual energies, which frequently occur during the operation of a network. To address these two issues, we present a novel clustering technique, Dynamic Clustering with Relay Nodes (DCRN, by considering the heterogeneity in residual battery capacity and by removing the assumption that relay nodes always serve as cluster-heads. We use an essence of the underlying mechanism of LEACH (Low-Energy Adaptive Clustering Hierarchy, which is one of the most popular clustering solutions for wireless sensor networks. In our work, we present four heuristics to increase network stability periods in terms of the time elapsed before the death of the first node in the network. Based on the proposed heuristics, we devise an algorithm for DCRN and formulate a mathematical model for its long-term rate of energy consumption. Further, we calculate the optimal percentage of relay nodes from our mathematical model. Finally, we verify the efficiency of DCRN and correctness of the mathematical model by exhaustive simulation results. Our simulation results reveal that DCRN enhances the network stability period by a significant margin in comparison to LEACH and its best-known variant.

Vijay Raghunathan

2012-06-01

288

Development of Laser Based Techniques for In-situ Characterization of the First Wall in ITER and Future Fusion Devices  

International Nuclear Information System (INIS)

Full text: In situ methods to measure the fuel retention and characterize the material deposition on the wall are highly important for ITER and future fusion devices. Laser-based methods are the most promising candidates (for non-invasive applications) and are being investigated in a cooperative undertaking in various European associations under EFDA coordination. The work concentrates on laser techniques by which the laser light is guided from outside the biological shield by a mirror system through a window onto special wall areas and on three different laser methods: 1. Laser induced desorption spectroscopy (LIDS) in which ms laser pulses thermally desorbs the retained fuel from a wall area of about 1 cm2 and the desorbed fuel is spectroscopically detected in the edge of a running plasma. 2. Laser induced ablation spectroscopy (LIAS) in which ns laser pulses ablates the a small wall spot and the ablated material together with the incorporated fuel is detected in a similar way as for LIDS. 3. Laser induced breakdown spectroscopy (LIBS) in which ns (or even ps ) laser pulses pulse produces a plasma plume which (in proper conditions) emits line radiation being a fingerprint of the chemical composition of the ablated materials in front of the irradiated wall spot. The aims are to compare the pros and cons of the methods and fix an optimized solution for ITER. LIDS and LIAS have been developed to a prototype-like status for ITER application in the TEXTOR tokaus for ITER application in the TEXTOR tokamak. LIBS has been investigated in several EU associations in dedicated lab experiments with a focus on the particular conditions in ITER, including pilot experiments in the TEXTOR tokamak. To enable a clear and fair quantification of the methods, standard deposits of diamond like carbon (DLC) and mixed W/Al/C (Al mimic Be here) with thicknesses of 2 - 3 ?m deposited on rough and polished W substrates with a known D inventory have been prepared by magnetron sputtering and vacuum arc deposition and used as standard samples in these observations. (author)

289

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

Science.gov (United States)

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

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

2014-04-22

290

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 hydrocarbonschlorinated 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.

291

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

OpenAIRE

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 s...

Grignard, Bruno; Gigmes, Didier; Je?ro?me, Christine; Detrembleur, Christophe

2009-01-01

292

Synthesis of 1,1-disubstituted tetrahydroisoquinolines by lithiation and substitution, with in situ IR spectroscopy and configurational stability studies.  

Science.gov (United States)

Lithiation of N-Boc-1-phenyltetrahydroisoquinolines was optimized by in situ IR spectroscopy. The kinetics for rotation of the carbamate group and for the enantiomerization of the organolithium were determined. The organolithium is configurationally stable at low temperature, and the asymmetric synthesis of 1,1-disubstituted tetrahydroisoquinolines can be achieved with high yields and high enantiomer ratios. The chemistry was applied to the preparation of FR115427 and provides a way to recycle the undesired enantiomer in the synthesis of solifenacin. PMID:24707968

Li, Xiabing; Coldham, Iain

2014-04-16

293

In situ, real-time thickness measurement techniques for bath-deposited CdS thin films on Cu(In,Ga)Se2  

International Nuclear Information System (INIS)

A technique has been developed that can measure the thickness of a 30–70 nm thin film of cadmium sulfide on a Cu(In,Ga)Se2 substrate, in real time, as it grows in a chemical bath. The technique does not damage the film, and can be used to monitor batch depositions and roll-to-roll depositions with equal accuracy. The technique is based on reflectance spectroscopy through the chemical bath. - Highlights: ? Reflection spectra were collected during the chemical bath deposition of CdS. ? Two algorithms were generated to extract film thickness from each spectrum. ? Two conventional techniques were used to independently verify CdS film thicknesses. ? The accuracies of the algorithms are within 7% of the actual thicknesses. ? The algorithms offer in situ, real time thicknesses through the chemical bath.

294

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

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.

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

2015-01-01

295

Phase stability of Heusler compound Co2FeSi under pressure: An in-situ x-ray diffraction investigation  

Science.gov (United States)

Results of ambient temperature synchrotron based in-situ x-ray powder diffraction measurements up to 24.8 GPa on the structural stability of the ferromagnetic shape memory Heusler alloy Co2FeSi is reported. The compound is structurally stable up to the highest pressure of the present investigations; however, the pressure (P) vs. volume (V) data shows an anomalous linearity beyond 4.7 GPa. The P-V data up to 4.7 GPa, when fitted to Birch-Murnaghan equation of states, gives the value of bulk modulus (B) as 240 GPa (B' = 4). The P-V data beyond 4.7 GPa can be fitted to a straight line implying a constant bulk modulus (B = 279.5 GPa, B' = 0.0) as seen in several metallic samples with highly correlated electrons.

Garg, Alka B.; Vijayakumar, V.

2011-10-01

296

Developing a western Siberia reference site for tropospheric water vapour isotopologue observations obtained by different techniques (in situ and remote sensing  

Directory of Open Access Journals (Sweden)

water cycle, affected by changes in air mass origin, non-convective and convective processes and continental recycling. Novel remote sensing and in situ measuring techniques have recently offered opportunities for monitoring atmospheric water vapour isotopic composition. Recently developed infrared laser spectrometers allow for continuous in situ measurements of surface water vapour ?Dv and ?18Ov. So far, very few intercomparisons of measurements conducted using different techniques have been achieved at a given location, due to difficulties intrinsic to the comparison of integrated with local measurements. Nudged simulations conducted with high-resolution isotopically enabled general circulation models (GCMs provide a consistent framework for comparison with the different types of observations. Here, we compare simulations conducted with the ECHAM5-wiso model with two types of water vapour isotopic data obtained during summer 2012 at the forest site of Kourovka, western Siberia: hourly ground-based FTIR total atmospheric columnar ?Dv amounts, and in situ hourly Picarro ?Dv measurements. There is an excellent correlation between observed and predicted ?Dv at surface while the comparison between water column values derived from the model compares well with FTIR estimates.

K. Gribanov

2014-06-01

297

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

OpenAIRE

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 ...

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

2014-01-01

298

Evidence for the formation of distorted nanodomains involved in the phase transformation of stabilized zirconia by coupling convergent beam electron diffraction and in situ TEM nanoindentation  

International Nuclear Information System (INIS)

The transformation of zirconia from its tetragonal to its monoclinic phase is an important feature of the zirconia system. First found to be an advantage due to its important toughening effect, it can also be very detrimental when it occurs in the framework of low-temperature degradation, particularly in the case of biomaterial applications. One way to avoid or to control this phase transformation is to understand how it initiates and more particularly the stress states that can trigger it. A new technique available inside a transmission electron microscope seems to be particularly well suited for that type of study: convergent beam electron diffraction, a well-known technique to reveal stresses, was coupled to in situ transmission electron microscopy mechanical nanoindentation. The experiments reveal the presence of sheared nanoregions at grain boundaries. These could act as embryos for tetragonal-to-monoclinic phase transformations. This is an important first step in the understanding of the earliest stage of zirconia phase transformation.

299

Engineered In-Situ Precipitation of Technetium and Uranium in Groundwater at the Savannah River Site: Treatment Targeting Long-Term Stability (Invited)  

Science.gov (United States)

The U.S. Department of Energy (DOE) Savannah River Site (SRS) is a former nuclear weapons facility that is undergoing clean-up of groundwater and soil contamination. Alternatives to conventional pump-and-treat are being evaluated through DOE’s Advanced Remediation Technologies (ART) program as part of the EM-22 Groundwater and Soil Remediation program. A pilot project is underway to evaluate an emerging approach to remediation through the in-situ precipitation of insoluble forms of technetium and uranium. The demonstration involves the injection of organic carbon into the aquifer to stimulate biogeochemical processes leading to the transformation of soluble radionuclides to insoluble forms. However, once carbon addition is ceased and geochemical conditions return to oxidizing, the insoluble radionuclides may re-dissolve. The pilot project will target long term stability by enhancing the creation of reduced mineral forms in and around the precipitated radionuclides to act as both a redox buffer for oxidizing groundwater and as a sorptive medium for any dissolved uranium and technetium. Successful treatment with respect to in situ radionuclide precipitation extends beyond numeric cleanup goals and invokes a standard of care that considers not only short-term solubility achieved during active remediation, but the range of factors that might erode/compromise the stability of the precipitated solids over the long-term. Long-term stability may be achieved by incorporating the targeted radionuclide in a matrix of other precipitates formed through the treatment process. In the short term, this can include the precipitates of other more abundant metals (e.g., iron) that can preferentially scavenge oxygen. Longer term, this is expected to transition to passivation within a matrix of more stable mineral phases, such that rates of rebound dissolution are sufficiently suppressed to maintain dissolved concentrations below remedial targets. The in situ reactive zone (IRZ) treatment will be sustained for 2 years, followed by a period of rebound monitoring to determine the stability of the insoluble metals and radionuclides. The treatment will promote microbial sulfate-reducing conditions in order to facilitate uranium precipitation as well as formation of sparingly soluble technetium phases incorporated into iron sulfide and other biogenic iron minerals. A key to sustained treatment is the establishment of a mass of minerals within the treatment zone capable of consuming incoming oxidants (present in the naturally oxic aquifer) as well as the creation of sorptive mineral phases for long-term stabilization. Soil samples were obtained during well installation for geochemical, radiological, and mineralogical analysis to establish the baseline conditions; the biogenic mineral matrix will be characterized in the post-treatment soil samples. A key aspect for achieving optimum treatment is through initial tracer testing, which is being used to refine substrate distribution strategy. The treatment pilot will be discussed in the context of this strategy.

Gillow, J. B.; Lutes, C. C.; Frizzell, A.; Clark, B.; Horst, J.

2009-12-01

300

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

Science.gov (United States)

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

301

Functionalization of UiO-66 Metal-Organic Framework and Highly Cross-Linked Polystyrene with Cr(CO)(3): In Situ Formation, Stability, and Photoreactivity  

OpenAIRE

The formation and stability of (arene)Cr(CO)3 species inside two highly porous materials;UiO-66, which is a recently synthesized metal-organic framework, and a cross-linked poly(styrene-codivinylbenzene) resin;are investigated in detail by means of complementary spectroscopic techniques and theoretical calculations. In particular, Fourier transform infrared (FT-IR), ultravioletvisible (UV-vis), and X-ray absorption near-edge structure (XANES) spectroscopies, coupled with theore...

Bonino, Francesca Carla; Groppo, Elena Clara; Bordiga, Silvia; Lamberti, Carlo; Vitillo, Jenny Grazia; Chavan, Sachin Maruti; Uddin, Mohammed Jasim

2010-01-01

302

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

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

1743-17-01

303

Application of precipitation methods for the production of water-insoluble drug nanocrystals: production techniques and stability of nanocrystals.  

Science.gov (United States)

This review focuses on using precipitation (bottom-up) method to produce water-insoluble drug nanocrystals, and the stability issues of nanocrystals. The precipitation techniques for production of ultra-fine particles have been widely researched for last few decades. In these techniques, precipitation of solute is achieved by addition of a non-solvent for solute called anti-solvent to decrease the solvent power for the solute dissolved in a solution. The anti-solvent can be water, organic solvents or supercritical fluids. In this paper, efforts have been made to review the precipitation techniques involving the anti-solvent precipitation by simple mixing, impinging jet mixing, multi-inlet vortex mixing, the using of high-gravity, ultrasonic waves and supercritical fluids. The key to the success of yielding stable nanocrystals in these techniques is to control the nucleation kinetics and particle growth through mixing during precipitation based on crystallization theories. The stability issues of the nanocrystals, such as sedimentation, Ostwald ripening, agglomeration and cementing of crystals, change of crystalline state, and the approaches to stabilizing nanocrystals are also discussed in detail. PMID:23651396

Xia, Dengning; Gan, Yong; Cui, Fude

2014-01-01

304

In situ coating of low-Z materials by reactive vacuum arc-deposition with a stabilized arc cathode  

International Nuclear Information System (INIS)

For in situ regeneration of low-Z coatings on the first wall, the vacuum arc-deposition method has desirable characteristics such as a high deposition rate, very low ambient pressure, high ionization rate and compact source that can be directed in any direction. In this experiment, a vacuum arc source of an ion-gun type was developed that can coat locally at a much higher deposition rate than conventional arc sources. The special features of the arc sources are as follows: (1) the cathode is a cylindrical rod that has a small gas channel along the central axis, and the arc spots are concentrated around the gas nozzle on the cathode surface. (2) The reactive gas is pre-ionized by RF discharge to increase reaction rate. (3) A shield surrounds the cathode with a small gap to confine arc spots within a certain area. (orig.)

305

In situ coating of low-Z materials by reactive vacuum arc-deposition with a stabilized arc cathode  

Science.gov (United States)

For in situ regeneration of low-Z coatings on the first wall, the vacuum arc-deposition method has desirable characteristics such as a high deposition rate, very low ambient pressure, high ionization rate and compact source that can be directed in any direction. In this experiment, a vacuum arc source of an ion-gun type was developed that can coat locally at a much higher deposition rate than conventional arc sources. The special features of the arc sources are as follows: (1) the cathode is a cylindrical rod that has a small gas channel along the central axis, and the arc spots are concentrated around the gas nozzle on the cathode surface. (2) The reactive gas is pre-ionized by RF discharge to increase reaction rate. (3) A shield surronds the cathode with a small gap to confine arc spots within a certain area.

Shinno, H.; Fukutomi, M.; Fujitsuka, M.; Okada, M.

1985-08-01

306

Stability-enhanced indium hexacyanoferrate electrodes: Morphological characterization, in situ EQCM analysis in nonaqueous electrolytes and application to a WO3 electrochromic device  

International Nuclear Information System (INIS)

This paper presents a promising transparent counterelectrode system for a WO3 electrochromic device (ECD) on the basis of a stability-enhanced indium hexacyanoferrate (InHCF) electrode and a NaClO4/propylene carbonate (PC) electrolyte. Through SEM characterization it was found that clusters of granular InHCF nanoparticles (ca. 80-140 nm) were deposited on ITO substrates in HCl and KCl-stabilized plating solutions, and uniform micrometer thick films with high charge capacity could be obtained. From in situ electrochemical quartz crystal microbalance study, it was discovered that Na+ would enter or move out from the InHCF film in the 'desolvated' form during the redox process in a PC electrolyte. Besides, NaClO4/PC resulted in higher electrochemical activity and reversibility than LiClO4/PC. With these discoveries, a durable WO3-InHCF ECD featuring blue-to-colorless electrochromism was fabricated successfully. The device remained 73.6 and 88.7% of its initial ?T values at 600 and 800 nm after 40,000 rapid and successive coloring/bleaching cycles, respectively. Moreover, the cycling-induced loss of electrochromic performance almost completely restored after 1-month rest and kept unchanged for another month. Thus, the applicability of this nonaqueous InHCF counterelectrode system to ECDs was verified

307

Stability-enhanced indium hexacyanoferrate electrodes: Morphological characterization, in situ EQCM analysis in nonaqueous electrolytes and application to a WO{sub 3} electrochromic device  

Energy Technology Data Exchange (ETDEWEB)

This paper presents a promising transparent counterelectrode system for a WO{sub 3} electrochromic device (ECD) on the basis of a stability-enhanced indium hexacyanoferrate (InHCF) electrode and a NaClO{sub 4}/propylene carbonate (PC) electrolyte. Through SEM characterization it was found that clusters of granular InHCF nanoparticles (ca. 80-140 nm) were deposited on ITO substrates in HCl and KCl-stabilized plating solutions, and uniform micrometer thick films with high charge capacity could be obtained. From in situ electrochemical quartz crystal microbalance study, it was discovered that Na{sup +} would enter or move out from the InHCF film in the 'desolvated' form during the redox process in a PC electrolyte. Besides, NaClO{sub 4}/PC resulted in higher electrochemical activity and reversibility than LiClO{sub 4}/PC. With these discoveries, a durable WO{sub 3}-InHCF ECD featuring blue-to-colorless electrochromism was fabricated successfully. The device remained 73.6 and 88.7% of its initial {delta}T values at 600 and 800 nm after 40,000 rapid and successive coloring/bleaching cycles, respectively. Moreover, the cycling-induced loss of electrochromic performance almost completely restored after 1-month rest and kept unchanged for another month. Thus, the applicability of this nonaqueous InHCF counterelectrode system to ECDs was verified.

Hong, S.-F. [Department of Bio-Industrial Mechatronics Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Chen, L.-C. [Department of Bio-Industrial Mechatronics Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Bioenergy Research Center, National Taiwan University, Taipei 10617, Taiwan (China)], E-mail: chenlinchi@ntu.edu.tw

2008-06-30

308

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

309

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2013-08-07

310

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

311

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)

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.

Zawacka, Natalia Klaudia; Andersen, Thomas Rieks

2014-01-01

312

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

313

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

Directory of Open Access Journals (Sweden)

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

Ali Ahmad Ghotbi

2012-04-01

314

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

OpenAIRE

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

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

2008-01-01

315

In situ mechanical behavior of mineral crystals in human cortical bone under compressive load using synchrotron X-ray scattering techniques.  

Science.gov (United States)

It is of great interest to delineate the effect of orientation distribution of mineral crystals on the bulk mechanical behavior of bone. Using a unique synergistic approach combining a progressive loading scheme and synchrotron X-ray scattering techniques, human cortical bone specimens were tested in compression to examine the in situ mechanical behavior of mineral crystals aligned in different orientations. The orientation distribution was quantitatively estimated by measuring the X-ray diffraction intensity from the (002) plane in mineral crystals. In addition, the average longitudinal (c-axis), transverse (a-axis), and shear strains of the subset of mineral crystals aligned in each orientation were determined by measuring the lattice deformation normal to three distinct crystallographic planes (i.e. 002, 310, and 213) in the crystals. The experimental results indicated that the in situ strain and stress of mineral crystals varied with orientations. The normal strain and stress in the longitudinally aligned mineral crystals were markedly greater than those in the transversely oriented crystals, whereas the shear stress reached a maximum for the crystals aligned in ±30° with respect to the loading direction. The maximum principal strain and stress were observed in the mineral crystals oriented along the loading axis, with a similar trend observed in the maximum shear strain and stress. By examining the in situ behavior, the contribution of mineral crystals to load bearing and the bulk behavior of bone are discussed. PMID:22982959

Giri, Bijay; Almer, Jonathan D; Dong, X Neil; Wang, Xiaodu

2012-10-01

316

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

CERN Document Server

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...

Gerakines, P A

2015-01-01

317

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 treatments for DM, OM, CP and Ash contents. Residual WSC and CP contents decreased and the concentration of NH3-N increased with time post ensiling. Corn silage inoculated with the homofermentative inoculant had the lowest pH in all ensiling times except that of 28 days. Inoculated corn silage had lower pH than untreated corn silage at all ensiling times. Although, inoculation of corn silage significantly affected ruminal degradability of DM, but ruminal CP degradability was not influenced. Inoculation of corn silage had a significant effect on gas production from the corn silage. It was concluded that inoculation of corn silage improved ensiling characteristics; however the fresh culture inoculant did not have a remarkable effect compared with the commercially produced inoculant.

Bayatkouhsar et al.

2012-09-01

318

An in-situ, high-energy X-ray diffraction study of the thermal stability of delithiated LiVPO4F  

Science.gov (United States)

Differential scanning calorimetry (DSC) and in-situ high-energy X-ray diffraction (HEXRD) techniques were used to investigate the high-temperature reactions of a cathode containing Li1-xVPO4F with materials found in a lithium-ion cell, such as graphite additive in the cathode and the electrolyte. The DSC results indicate that the energy released during the reaction of the cathode containing Li1-xVPO4F with the electrolyte was about 1/3 of that released during a similar reaction of the delithiated, layered cathode containing Li1.1[Ni1/3Mn1/3Co1/3]0.9O2. The in-situ HEXRD results provide evidence that the delithiated material, Li1-xVPO4F, reacts with protons and/or lithium ions found in the reaction mixture at elevated temperature, producing an LiVPO4F-like compound. This reaction is the most likely cause for the low energy release during heating, that is, the LiVPO4F-like material appears to be thermally stable at temperatures up to 400 °C in the presence of LiPF6.

Piao, Ying; Lin, Chi-kai; Qin, Yan; Zhou, Dehua; Ren, Yang; Bloom, Ira; Wei, Yingjin; Chen, Gang; Chen, Zonghai

2015-01-01

319

In situ growth of hollow gold-silver nanoshells within porous silica offers tunable plasmonic extinctions and enhanced colloidal stability.  

Science.gov (United States)

Porous silica-coated hollow gold-silver nanoshells were successfully synthesized utilizing a procedure where the porous silica shell was produced prior to the transformation of the metallic core, providing enhanced control over the structure/composition of the bimetallic hollow core. By varying the reaction time and the precise amount of gold salt solution added to a porous silica-coated silver-core template solution, composite nanoparticles were tailored to reveal a readily tunable surface plasmon resonance that could be centered across the visible and near-IR spectral regions (?445-800 nm). Characterization by X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, scanning electron microscopy, and transmission electron microscopy revealed that the synthetic methodology afforded particles having uniform composition, size, and shape. The optical properties were evaluated by absorption/extinction spectroscopy. The stability of colloidal solutions of our composite nanoparticles as a function of pH was also investigated, revealing that the nanoshells remain intact over a wide range of conditions (i.e., pH 2-10). The facile tunability, enhanced stability, and relatively small diameter of these composite particles (?110 nm) makes them promising candidates for use in tumor ablation or as photothermal drug-delivery agents. PMID:25321928

Li, Chien-Hung; Jamison, Andrew C; Rittikulsittichai, Supparesk; Lee, Tai-Chou; Lee, T Randall

2014-11-26

320

In situ observation of defect growth beyond the irradiated region in yttria-stabilized zirconia induced by 400 keV xenon ion-beam at -90 and 30 C  

International Nuclear Information System (INIS)

Single crystals of yttria-stabilized zirconia (YSZ) were irradiated with 400 keV Xe ion-beam at room temperature and -90 C. Defect growth was monitored in situ with Rutherford backscattering and ion channeling (RBS/C) techniques using a 2 MeV He ion-beam. The irradiated YSZ was observed to consist of a 60 nm less-damaged or defect-denuded top layer, followed by a highly disordered layer. Ion channeling revealed that the degree of lattice disorder saturated at 70% of the random level in the bottom layer. At a dose of 3 x 1020 Xe/m2, this layer extended to a depth of 160 nm, well beyond the irradiated depth (<110 nm). Cross-sectional transmission electron microscopy observations along with RBS measurements are interpreted as indicating the presence of small Xe precipitates with an average diameter of 3 nm, uniformly distributed over the 20-110 nm depth. The study demonstrated that point defects generated in the Xe-irradiated region diffused and produced stable extended structural defects at depths beyond the irradiated region. (orig.)

321

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

322

Novel and simple technique to obtaining high-stability nanosecond pulse  

Science.gov (United States)

An Anti-Resonant Ring (ARR) structure was introduced to a conventional passively solid-state Q-switched Nd:YAG laser for the first time. Using a plane-ARR critical resonator, and Cr4+:YAG crystal, BDN dye film and color centered LiF:F-2 crystal as saturable absorber. High energy and high stability single Q-switched pulse with the output energies range from 101.6 - 82.5 mJ and stabilities range from 99.2 - 98.6% were obtained respectively. The experimental results were analyzed well by using the mechanism of the transient grating effect generated by ARR structure.

Wu, Feng-tie; Zhang, Wen-Zhen

2003-07-01

323

Application of in situ hybridization, cytochemical and immunocytochemical techniques for the investigation of peroxisomes. A review including novel data. Robert Feulgen Prize Lecture 1997.  

Science.gov (United States)

In situ hybridization, cytochemical and immunocytochemical techniques have contributed significantly to the understanding of the biology of peroxisomes, since they permit in situ demonstration of the sites of synthesis and distribution of peroxisomal proteins without the necessity of homogenization and subcellular fractionation of tissues or cultured cells. This article reviews the results of research on mammalian peroxisomal metabolism, biogenesis and proliferation in which morphological techniques have played a significant role in the elucidation of the biological problem. Some new data on peroxisomal heterogeneity and morphogenesis are included. The morphological methods applied have made it possible to characterize the differences in distribution of mRNAs encoding peroxisomal proteins in different tissues, as well as to monitor the marked heterogeneity in the protein composition and in the activity of specific enzymes in the peroxisomal population of single cells, or in tissues with complex organization (e.g. liver and kidney). In addition, the dynamic alterations and high plasticity of the peroxisomal compartment--partly dependent on contact of the peroxisomes to the microtubular network-are presented. PMID:9342614

Baumgart, E

1997-09-01

324

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

Science.gov (United States)

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

Sim, K S; White, J D

2005-03-01

325

In-situ surface technique analyses and ex-situ characterization of Si{1-x}Gex epilayers grown on Si(001)-2 × 1 by molecular beam epitaxy  

Science.gov (United States)

Si{1-x}Gex epilayers grown by Molecular Beam Epitaxy on Si(001) at 400 ^{circ}C have been analyzed in-situ by surface techniques such as X-ray and Ultraviolet Photoelectron Spectroscopies (XPS and UPS), Low Energy Electron Diffraction (LEED) and photoelectron diffraction (XPD). The Ge surface concentrations (x) obtained from the ratios of Ge and Si core level intensities are systematically higher than those obtained by the respective evaporation fluxes. This indicates a Ge enrichment in the first overlayers confirmed by Ge-like UPS valence band spectra. The structured crystallographic character of the epilayers is ascertained by LEED and XPD polar scans in the (100) plane since the Ge Auger LMM and the Si 2p XPD intensity patterns from the Si{1-x}Gex epilayers are identical to those of the Si substrate. The residual stress in the epilayer is determined by ex-situ X-ray diffraction (XRD) which also allows, as Rutherford Back Scattering (RBS), Ge concentration determinations. Des couches minces d'alliage Si{1-x}Gex épitaxiées à 400 ^{circ}C sur des substrats Si(001) sont caractérisées in situ par des techniques d'analyse de surface telles que la spectroscopie de photoélectrons X et ultraviolet (XPS, UPS), la diffraction d'électrons lents (LEED) et la diffraction de photoélectrons (XPD). Les concentrations de germanium en surface déterminées à partir des rapports d'intensité des niveaux de coeur du germanium et du silicium sont systématiquement supérieures à celles obtenues à partir des flux d'évaporation. Ce résultat indique un enrichissement en germanium des couches proches de la surface, confirmé par l'obtention de spectres UPS similaires à ceux du germanium massif. Les résultats de LEED et ceux obtenus par XPD confirment la structure cristallographique des couches dans la mesure où les variations angulaires de l'intensité des pics Auger LMM du germanium et Si2p du silicium dans l'alliage sont identiques à celles du silicium (001). La contrainte résiduelle dans la couche est déterminée par diffraction de rayons X qui, comme la RBS, permet d'accéder à la concentration de l'alliage en germanium.

Aubel, D.; Diani, M.; Stoehr, M.; Bischoff, J. L.; Kubler, L.; Bolmont, D.; Fraisse, B.; Fourcade, R.; Muller, D.

1994-04-01

326

Monitoring and evaluating the stability of soil slopes: A review on various available methods and feasibility of acoustic emission technique  

Science.gov (United States)

Landslide is considered as one of the major natural hazards that cause enormous social and economic losses. Some techniques have been introduced to monitor the stability of slopes, such as the global positioning system (GPS), the geographic information system (GIS), aerial photography, and inclinometers. Each one of these offers advantages against others, but at the same time also possesses different limitations. Acoustic emission (AE) has recently been recognized as one of the feasible techniques to monitor soil slope. This article addresses issues involved in application of AE techniques for soil slope monitoring. If it is properly instrumented, AE could provide effective solutions for detecting early activities related to landslide development and giving early warning to such failures.

Zaki, Ahmad; Chai, Hwa Kian; Razak, Hashim Abdul; Shiotani, Tomoki

2014-09-01

327

Organic aerosol composition measurements with advanced offline and in-situ techniques during the CalNex campaign  

Directory of Open Access Journals (Sweden)

Full Text Available 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. 153 compounds were identified using the GC×GC/TOF-MS, 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. 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.

J. Timkovsky

2014-12-01

328

Organic aerosol composition measurements with advanced offline and in-situ techniques during the CalNex campaign  

Science.gov (United States)

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). 153 compounds were identified using the GC×GC/TOF-MS, 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). 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.

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

2014-12-01

329

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

Science.gov (United States)

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

Hosanski, J. M.; Ledoux, E.

1982-03-01

330

In situ strain measurements of superconducting composites by depth and layer sensitive X-ray diffraction technique utilizing synchrotron radiation  

International Nuclear Information System (INIS)

Axial strain of Dy123 tape during tensile deformation was measured in situ with in-plane synchrotron radiation diffraction. Strain in Dy123 epitaxial layer increased with tensile strain, and remain constant after multiple cracking of the layer. With anomalous dispersion at Dy L3 edge, the Bragg peak from Dy123 layer was identified. Measured strain for Ag layer coated on the Dy123 suggests earlier yield of Ag. Strain of the layers in Dy123-based coated superconductor composite tapes under tensile load has been evaluated by in situ synchrotron radiation diffraction near the L3 absorption edge of Dy. In the present work, in-plane diffraction profile of the materials under tensile deformation with the scattering vector parallel to the axial load has been analyzed. The axial strain evaluated from the Dy123 peaks agreed with the average sample strain obtained from a separate mechanical test in elastic region. After Lueders deformation started, the strain of the Dy123 layer remained almost constant, in agreement with a multiple fracture model for ductile-fragile composite materials. Anomalous dispersion effect was used to identify the origin of the Bragg peak.

331

Wind Turbine Transient Stability Improvement in Power System Using PWM Technique and Fuzzy Controller  

Directory of Open Access Journals (Sweden)

Full Text Available In recent years, the increasing concerns to the environmental issues and the limited availability of conventional fossil fuels lead to rapid research and development for more sustainable and alternative electrical sources. Wind energy, as one of the most prominent renewable energy sources, is gaining increasing significance throughout the world. Distributed Generation (DG, based on renewable energy has become a development trend for electric power industry in 21stcentury. The currently worldwide installed capacity of grid connected wind generators grows rapidly. Therefore detailed analysis needs about the impact of wind power on system security and system operation. But DG is affected by natural conditions being not able to output power continuously and steadily. So when large scale wind turbine generators are incorporated into the grid, they will bring impact on electric power system stability. In order to ensure stable operation of electric power system, application of a super capacitor energy storage system (SCESS superior to other energy storage technologies and Doubly Fed Induction wind Generator (DFIG are presented in this paper. CESS is connected to the grid at the Point of Common Coupling (PCC. Matlab/Simulink software is used for modelling and simulation analysis. In this paper, transient stability problem if focussed. The simulation results obtained indicate that SCESS can improve transient stability of wind turbine generator system connected to the grid, and by using doubly fed induction generators, electric power system stability can be improved.

S.Radha Krishna Reddy

2013-03-01

332

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

CERN Document Server

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.

Staples, J W

2005-01-01

333

Laser Frequency Stabilization for Coherent Lidar Applications using Novel All-Fiber Gas Reference Cell Fabrication Technique  

Science.gov (United States)

Compact hollow-core photonic crystal fiber (HC-PCF)gas frequency reference cell was constructed using a novel packaging technique that relies on torch-sealing a quartz filling tube connected to a mechanical splice between regular and hollow-core fibers. The use of this gas cell for laser frequency stabilization was demonstrated by locking a tunable diode laser to the center of the P9 line from the (nu)1+(nu)3 band of acetylene with RMS frequency error of 2.06 MHz over 2 hours. This effort was performed in support of a task to miniaturize the laser frequency stabilization subsystem of JPL/LMCT Laser Absorption Spectrometer (LAS) instrument.

Meras, Patrick, Jr.; Poberezhskiy, Ilya Y.; Chang, Daniel H.; Levin, Jason; Spiers, Gary D.

2008-01-01

334

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

DEFF Research Database (Denmark)

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

Lira-Cantu, Monica; Tanenbaum, David M.

2012-01-01

335

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)

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.

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

2010-07-01

336

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.)

337

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-P 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

338

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

DEFF Research Database (Denmark)

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.

Mori, Aline Akemi; Lima, Fernanda Ferruzzi

2015-01-01

339

A Genetic Algorithm-based Technique to Enhance H? Controller: Stabilizes Acceleration in PMSM  

OpenAIRE

In recent years, a high class evolution has been achieved by control systems in different application areas. Acceleration control in Permanent Magnet Synchronous Motor is one among the noteworthy applications of evolving control systems. Though numerous methodologies have been proposed in the literature, they perform thecontrol operations statically. Moreover, controllers are very rarely used for this purpose. This leads to the problem of delayed stability in the acceleration/velocity control...

Viswanath, T. S.; Dr. Subhash S.K

2010-01-01

340

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

International Nuclear Information System (INIS)

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

341

Graphical technique for identifying a monotonic variance stabilizing transformation for absolute gene intensity signals  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The usefulness of log2 transformation for cDNA microarray data has led to its widespread application to Affymetrix data. For Affymetrix data, where absolute intensities are indicative of number of transcripts, there is a systematic relationship between variance and magnitude of measurements. Application of the log2 transformation expands the scale of genes with low intensities while compressing the scale of genes with higher intensities thus reversing the mean by variance relationship. The usefulness of these transformations needs to be examined. Results Using an Affymetrix GeneChip® dataset, problems associated with applying the log2 transformation to absolute intensity data are demonstrated. Use of the spread-versus-level plot to identify an appropriate variance stabilizing transformation is presented. For the data presented, the spread-versus-level plot identified a power transformation that successfully stabilized the variance of probe set summaries. Conclusion The spread-versus-level plot is helpful to identify transformations for variance stabilization. This is robust against outliers and avoids assumption of models and maximizations.

Dumur Catherine I

2004-05-01

342

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

Science.gov (United States)

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.

Wehner, W.; Schuster, E.

2012-07-01

343

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)

344

Design and development of technique for in-situ response time measurement of RTDs and implementation aspects for nuclear power plant application  

International Nuclear Information System (INIS)

Temperature sensors are used for the measurement of important parameters in Nuclear Power plant such as differential temperature across reactor core inlet and outlet, steam generator inlet and outlet temperature, measurement of surface temperature of selected fuel channels. These measurements are used to detect temperature transients due to process disturbances and are used to initiate safety action. Hence it is important that the temperature sensors (Resistance Temperature detectors (RTDs), thermocouples) used are accurate, well calibrated, and have fast response time. However, the response time of RTDs and thermocouples degrades during operation due to several factors such as corrosion of the thermowells, development of air gaps within the temperature sensor, vibrations, process pressure and temperature. Standards such as IEEE Std. 279-1991 requires that means be provided for checking the operational availability of each protection system input sensors during reactor operation. It also specifies a mandatory requirement that all the sensors installed in a nuclear power plant shall have in-situ periodic testability of parameters important to safety. In this paper, a technique for in-situ measurement of response time of RTDs and implementation aspects for plant application have been presented. (author)

345

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

346

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

Science.gov (United States)

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

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

2014-12-01

347

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

Energy Technology Data Exchange (ETDEWEB)

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.

Paul Fallgren

2009-02-20

348

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

International Nuclear Information System (INIS)

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 Nd2O3 in molteor of Nd2O3 in molten salt encouraged by the recent results of Yamana et. al

349

The use of a neutron backscatter technique for in-situ water measurement in paper-recycling industry  

International Nuclear Information System (INIS)

A bulk of used paper supplied to recycling industry may contain water in their internal voids. This is because the price of the used paper is currently based on their weight and it has a huge potential of suppliers to add with water in order to increase the price. Currently used methods for detecting moisture content in a paper are restricted to a sheet of paper only. This paper presents a non-intrusive method for quick and in-situ measurement of water content in a bulk of used paper. The proposed method extends the capability of common paper moisture gauge, by using a neutron device. A fast neutron source (Am-Be 241) and a portable backscattering neutron detector are used for water measurement. It theoretically indicates that the slow neutron counts can be correlated to the hydrogen or water level in a paper. The method has the potential of being used by the paper-recycling industry for rapid and non-destructive measurement of water in a bulk of used paper.

350

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

Directory of Open Access Journals (Sweden)

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 1.2–1.4 mol CH4 kg?1 porewater at in-situ pressure, which is equivalent to a gas hydrate saturation of 15–18% 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 22–24% 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 C2–C3 and the presence of C5.

K. U. Heeschen

2011-12-01

351

Study on the annealing process of in-situ MgB 2/Fe tapes by advanced spark plasma sintering (SPS) technique  

Science.gov (United States)

In-situ MgB 2/Fe tapes were fabricated by powder-in-tube (PIT) technology using Mg and B powders. The tapes were sintered by advanced spark plasma sintering (SPS) technique. The effects of the annealing parameters on the properties of the MgB 2 tapes were investigated by the analysis of XRD, SEM and the magnetic Jc measurements. It was shown that at 10 K, 0 T, the Jc value of the tape sintered using SPS machine at 800 °C for 15 min under 40 MPa was close to 10 6 A/cm 2, which was higher than that of the same tapes annealed by conventional method. It was supposed that the density and the homogeneity of the MgB 2 core were strongly improved using fast SPS sintering process. Further enhancement of Jc in the tapes is expected for the understanding of the SPS sintering mechanism.

Suo, HongLi; Wang, Ying; Ma, HongXia; Ma, Lin; Liu, Min; Zhao, Yue; Zhou, MeiLing

2007-09-01

352

Study on the annealing process of in-situ MgB2/Fe tapes by advanced spark plasma sintering (SPS) technique  

International Nuclear Information System (INIS)

In-situ MgB2/Fe tapes were fabricated by powder-in-tube (PIT) technology using Mg and B powders. The tapes were sintered by advanced spark plasma sintering (SPS) technique. The effects of the annealing parameters on the properties of the MgB2 tapes were investigated by the analysis of XRD, SEM and the magnetic Jc measurements. It was shown that at 10 K, 0 T, the Jc value of the tape sintered using SPS machine at 800 deg. C for 15 min under 40 MPa was close to 106 A/cm2, which was higher than that of the same tapes annealed by conventional method. It was supposed that the density and the homogeneity of the MgB2 core were strongly improved using fast SPS sintering process. Further enhancement of Jc in the tapes is expected for the understanding of the SPS sintering mechanism

353

In-situ void formation technique using an AlN shell structure grown on GaN stripes on Si(111) and c-plane sapphire substrates  

Energy Technology Data Exchange (ETDEWEB)

We proposed an in-situ void formation technique using high-temperature AlN growth on GaN stripes in order to reduce residual stress. Microcracks were observed during the growth of AlN; the GaN stripes then sublimated from the microcracks while keeping the AlN shell, resulting in void formation in the AlN shell structure. After GaN regrowth on this AlN shell structure, we successfully coalesced the GaN stripes to form a smooth, thick GaN layer having voids at the GaN/substrate interface. Raman spectroscopy confirmed that the residual tensile stress was decreased. The thermal stress decreased owing to the separation between the GaN layer and a foreign substrate. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Mitsunari, Tadashi; Tanikawa, Tomoyuki; Honda, Yoshio; Yamaguchi, Masahito; Amano, Hiroshi [Electrical and Computer Science and Akasaki Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603 (Japan)

2012-03-15

354

In situ observations of instabilities in the mesopause region using foil chaff technique during the Waves in Airglow Structures Experiment (WAVE) campaigns  

Science.gov (United States)

In order to investigate the dynamics of the mesopause region, foil chaff experiments were carried out successfully during the WAVE2000 and WAVE2004 campaigns at Kagoshima, Japan. In the WAVE2004 campaign, the height profiles of the horizontal and vertical wind speeds were obtained. The wind shear layers of >40 m/s/km were located around the altitudes of 89 and 95 km, and the profile of the Richardson number reveals the existence of dynamically unstable layers at about the same height region. Ripple observations using the all-sky imagers also support the possibility of dynamical instabilities. In the WAVE2000 campaign, a prominent small-scale feature around an altitude of 90.5 km appeared in both the horizontal and vertical chaff motions. These results demonstrate that the foil chaff technique is a valuable tool for in situ observation of small-scale turbulence features around the mesopause.

Koizumi, Yoshiko; Kubota, Minoru; Murayama, Yasuhiro; Abo, Makoto; Uchiumi, Michihiro; Igarashi, Kiyoshi; Iwagami, Naomoto; Abe, Takumi; Oyama, Koh-Ichiro

2009-10-01

355

A transposed frequency technique for phase noise and frequency stability measurements  

CERN Document Server

A measurement technique for active devices operating at microwave frequencies is presented, that allows one to measure their phase noise on a transposed carrier of only several MHz. The method is significantly different to the usual homodyne baseband technique where one must maintain the voltage from a calibrated mixer close to zero. Here the phase fluctuations of the microwave device are added to a low frequency auxiliary oscillator signal which can easily be measured using a commercial phase noise test set even though it may have an input bandwidth limited to only 30 MHz.

Hartnett, John G; Parker, Stephen

2012-01-01

356

Combined techniques of Raman spectroscopy and synchrotron two-dimensional x-ray diffraction for in situ study of anisotropic system: Example of polymer fibers under deformation  

International Nuclear Information System (INIS)

Simultaneous measurements of Raman spectroscopy and synchrotron two-dimensional (2D) wide-angle x-ray diffraction (WAXD) have been successfully demonstrated for in situ study of an anisotropic system: isotactic polypropylene (iPP) fiber under tensile deformation. A fiber-optic probe was used to remotely deliver the incident laser beam on the sample as well as to collect the Raman signal based on the confocal arrangement, whereas high resolution 2D WAXD patterns were obtained simultaneously at the same position during deformation of polymers. The combined techniques yielded complementary information on the molecular structural evolution in both crystalline and amorphous phases. 2D WAXD results showed that the ?-form iPP crystals were converted into the mesophase upon stretching at room temperature. Corresponding Raman spectra showed that characteristic bands from the crystal phase became weaker or disappeared during the transition from the crystal phase to the mesophase. However, the bands associated with the helical structure were still present, indicating the remainder of the helical conformation in the mesomorphic phase. The persistence of the Raman band at 812 cm-1 in the mesophase implied that the structural difference between the crystal phase and the mesophase in iPP is due to the packing defects, rather than the conformational deviations from the (···TGTG···) sequence in chains. The variations in the Raman intensity ratio (I812/I843) indicatedtensity ratio (I812/I843) indicated that the overall orientation of the fiber increased during stretching. The demonstrated techniques will be particularly useful for in situ studies of anisotropic polymers, where orientational dependent structural information from both crystalline and amorphous phases needs to be collected simultaneously

357

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

358

Structural and optical studies of Zn1-xCdxS quantum dots synthesized by in situ technique in PVA matrix  

Science.gov (United States)

Zn1-xCdxS (x = 0.1, 0.2, 0.3, 0.4, 0.5 … 0.9) quantum dots were synthesized successfully using novel in situ technique in polyvinyl alcohol (PVA) matrix. The PVA acted as a capping agent as well as a reducing agent. The structural and optical properties of the samples were studied by X-ray diffraction (XRD), TEM analysis, UV-Visible absorption and photoluminescence spectroscopy (PL). X-ray diffraction patterns revealed cubic zinc blende phase of the samples with lattice parameter in the range 5.47-5.75 Å. Optical band gap values were calculated from the absorption spectra and observed a decreasing band gap with increasing Cd:Zn ratio. The Raman spectra were recorded using conventional Micro Raman technique. Photoluminescence spectra showed asymmetric broad emission with multiple maxima. The concentration dependent quenching of PL intensity with increasing Cd:Zn ratio was observed along with a red shift. The nonlinear optical (NLO) and limiting properties were studied using Z-scan technique.

Vineeshkumar, T. V.; Rithesh Raj, D.; Prasanth, S.; Unnikrishnan, N. V.; Philip, Reji; Sudarsanakumar, C.

2014-11-01

359

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-gammamin-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)

360

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

Science.gov (United States)

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

Ebrahimpour, Omid

361

Uranium Plume Treatability Demonstration at the Hanford Site 300 Area: Development of Polyphosphate Remediation Technology for In-Situ Stabilization of Uranium - 8070  

International Nuclear Information System (INIS)

A groundwater plume containing uranium, originating from a combination of purposeful discharges of wastewater to cribs, trenches and ponds, along with some accidental leaks and spills during nuclear fuel fabrication activities, has persisted beneath the Hanford Site 300 Area for many years. Despite the cessation of uranium releases and the removal of shallow vadose zone source materials, the goal of less than 30 (micro)g/L has not been achieved within the anticipated 10-year time period. Polyphosphate technology has been demonstrated to delay the precipitation of phosphate phases for controlled in situ precipitation of stable phosphate phases to control the long-term fate of uranium. Precipitation occurs when polyphosphate compounds hydrolyze to yield the orthophosphate molecule. Based on the hydrolysis kinetics of the polyphosphate polymer, the amendment can be tailored to act as a time-released source of phosphate for lateral plume treatment, immediate and sustained remediation of dissolved uranium, and to preclude rapid precipitation which could result in a drastic change in hydraulic conductivity of the target aquifer. Critical to successful implementation of polyphosphate remediation technology is a site specific evaluation and optimization of multi-length polyphosphate amendment formulations. A multi-faceted approach has been taken to provide key fundamental science knowledge regarding optimization of the polyphosphate remedy through: (1) phosphorus-31 nuclear memedy through: (1) phosphorus-31 nuclear magnetic resonance to quantify the effects of Hanford groundwater and sediment on the degradation of inorganic phosphates, (2) static tests to quantify the kinetics, loading, and stability of apatite as a long-term sorbent for uranium, and (3) single-pass flow through testing to quantify the stability of autunite and apatite under relevant site conditions. Dynamic column tests were utilized to (1) optimize the composition of the polyphosphate formulation for the formation and emplacement of apatite and autunite, (2) understand the rate and extent of reaction between polyphosphate and uranium-bearing phases, (3) evaluate the effect of chemical microenvironments on the degradation of polyphosphate and the formation of autunite, and (4) quantify the mobility of polyphosphate as a function of water content. These activities are being conducted in parallel with a limited field investigation, to more accurately define the vertical extent of uranium in the vadose zone, and in the capillary fringe laterally throughout the plume

362

Effect of annealing temperature on the corrosion behavior of duplex stainless steel studied by in situ techniques  

International Nuclear Information System (INIS)

Highlights: ? The volume fraction of austenite in DDS 2507 decreased as annealing temperature increased from 1050 to 1150 deg. C. ? The paramagnetic austenite showed a nobler Volta potential than ferromagnetic ferrite. ? The Volta potential difference between ferrite and austenite is the largest at 1100 deg. C and the smallest at 1150 deg. C. ? The preferential corrosion occurred in the ferrite phase in hydrochloric acid solution. ? The corrosion rate is highest at 1100 deg. C and lowest at 1150 deg. C. - Abstract: The effects of the annealing temperature on the microstructure and the corrosion behavior of duplex stainless steel 2507 were investigated by means of magnetic force microscopy (MFM), scanning Kelvin probe force microscopy (SKPFM), atomic force microscopy (AFM) and scanning electron microscopy (SEM). The SEM results indicated that the volume fraction of the austenite phase decreased with the increased annealing temperature. SKPFM/MFM measurements conducted in air at the room temperature and an ambient relative humidity of about 25% showed a higher Volta potential of the paramagnetic austenite than that of the ferromagnetic ferrite. The in situ AFM observation in a hydrochloric acid solution provided solid evidence that corrosion preferentially occurred in the ferrite phase. The sample annealed at 1100 deg. C exhibited a greater Volta potential difference between the ferrite and austenite and a higher corrosion rate in the ferrite, while that anneain the ferrite, while that annealed at 1150 deg. C had a smaller Volta potential difference and a lower corrosion rate. The relative nobility and microstructure change of two phases, as well as their corrosion behavior, can be explained by the effect of the composition of alloying elements.

363

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

Science.gov (United States)

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

Liu, Ruiqiang; Zhao, Dongye

2013-04-01

364

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

365

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)

366

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

367

Field assessment of guar gum stabilized microscale zerovalent iron particles for in-situ remediation of 1,1,1-trichloroethane  

Science.gov (United States)

A pilot injection test with guar gum stabilized microscale zerovalent iron (mZVI) particles was performed at test site V (Belgium) where different chlorinated aliphatic hydrocarbons (CAHs) were present as pollutants in the subsurface. One hundred kilograms of 56 ?m-diameter mZVI (~ 70 g L- 1) was suspended in 1.5 m3 of guar gum (~ 7 g L- 1) solution and injected into the test area. In order to deliver the guar gum stabilized mZVI slurry, one direct push bottom-up injection (Geoprobe) was performed with injections at 5 depths between 10.5 and 8.5 m bgs. The direct push technique was preferred above others (e.g. injection at low flow rate via screened wells) because of the limited hydraulic conductivity of the aquifer, and to the large size of the mZVI particles. A final heterogeneous distribution of the mZVI in the porous medium was observed explicable by preferential flow paths created during the high pressure injection. The maximum observed delivery distance was 2.5 m. A significant decrease in 1,1,1-TCA concentrations was observed in close vicinity of spots where the highest concentration of mZVI was observed. Carbon stable isotope analysis (CSIA) yielded information on the success of the abiotic degradation of 1,1,1-TCA and indicated a heterogeneous spatio-temporal pattern of degradation. Finally, the obtained results show that mZVI slurries stabilized by guar gum can be prepared at pilot scale and directly injected into low permeable aquifers, indicating a significant removal of 1,1,1-TCA.

Velimirovic, Milica; Tosco, Tiziana; Uyttebroek, Maarten; Luna, Michela; Gastone, Francesca; De Boer, Cjestmir; Klaas, Norbert; Sapion, Hans; Eisenmann, Heinrich; Larsson, Per-Olof; Braun, Juergen; Sethi, Rajandrea; Bastiaens, Leen

2014-08-01

368

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)

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.

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

1999-01-01

369

Assessment of the heating technique as a possible ex situ detritiation method for carbon wall materials from fusion machines  

Science.gov (United States)

Detritiation by heat treatment of graphite or carbon fibre composite (CFC) tiles retrieved from the Tokamak Fusion Test Reactor (TFTR) was assessed using the standard and well proved technique of full combustion combined with liquid scintillation analysis. Complete carbon tiles were heated in a oven to 500 °C in air for one hour at Princeton Plasma Physics Laboratory (PPPL) and sent to Tritium Laboratory Karlsruhe (TLK) for surface and depth profile analysis. Coring/full combustion technique performed on the treated and untreated tiles, both graphite and CFC, has shown that only the tritium held close to the surface (few tens ?m) is efficiently released by baking in air while the bulk tritium is almost unaffected. Therefore, baking the tile under air, even at 500 °C, does not detritiate the bulk.

Bekris, N.; Skinner, C. H.; Berndt, U.; Gentile, C. A.; Glugla, M.; Erbe, A.; Pilz, W.

2004-08-01

370

Assessment of the heating technique as a possible ex situ detritiation method for carbon wall materials from fusion machines  

Energy Technology Data Exchange (ETDEWEB)

Detritiation by heat treatment of graphite or carbon fibre composite (CFC) tiles retrieved from the Tokamak Fusion Test Reactor (TFTR) was assessed using the standard and well proved technique of full combustion combined with liquid scintillation analysis. Complete carbon tiles were heated in a oven to 500 deg. C in air for one hour at Princeton Plasma Physics Laboratory (PPPL) and sent to Tritium Laboratory Karlsruhe (TLK) for surface and depth profile analysis. Coring/full combustion technique performed on the treated and untreated tiles, both graphite and CFC, has shown that only the tritium held close to the surface (few tens {mu}m) is efficiently released by baking in air while the bulk tritium is almost unaffected. Therefore, baking the tile under air, even at 500 deg. C, does not detritiate the bulk.

Bekris, N. E-mail: nicolas.bekris@hvt.fzk.de; Skinner, C.H.; Berndt, U.; Gentile, C.A.; Glugla, M.; Erbe, A.; Pilz, W

2004-08-01

371

In situ high-pressure synchrotron X-ray diffraction study of the structural stability in the intermetallic compound Mn{sub 2}Sb  

Energy Technology Data Exchange (ETDEWEB)

Cu{sub 2}Sb-type (Strukturbericht designation: C38) intermetallic compound Mn{sub 2}Sb was studied up to 25.7 GPa at room temperature using the in situ synchrotron powder X-ray diffraction (XRD) technique. Our results from the XRD analysis showed that the (C38)-type Mn{sub 2}Sb undergoes a pressure-induced structural phase transition near 22.4 GPa. In the low-pressure (LP) phase of Mn{sub 2}Sb, an anisotropic compressibility was observed with greater compressibility along the a-axis than the c-axis. And the mechanism for the anisotropy of compressibility was discussed in terms of the stacking of crystallography. Fitted to a third-order Birch-Murnaghan equation of state (BM-EOS), the pressure-volume data of Mn{sub 2}Sb yielded the stable lattice volume V{sub 0} = 109.45(3) Aa{sup 3}, bulk modulus B{sub 0} = 50.1(5) GPa, and its derivative B'{sub 0} = 7.0(2) for the LP phase. We propose that the distortion of Mn(I)Sb{sub 4} tetrahedra may give rise to the structural instability of Mn{sub 2}Sb under high pressure (HP). (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Yu, Z.H. [Department of Physics, Harbin Institute of Technology, Harbin 150080 (China); XSD, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States); Li, C.Y. [Department of Physics, Harbin Institute of Technology, Harbin 150080 (China); Photon Sciences Directorate, Brookhaven National Laboratory, Upton, NY 11973 (United States); Liu, H.Z. [Natural Science Research Center, Harbin Institute of Technology, Harbin 150080 (China)

2012-11-15

372

Evolutionary Programming Based Technique for Secure Operating Point Identification in Static Voltage Stability Assessment  

OpenAIRE

This study presents a critical evaluation of maximum loadability point estimation in a power system network. The critical point estimation involved maximum loadability estimation on individual load buses and simultaneous increase at several load buses. Different modes of evaluation determine the margin of load increase between the single and several loads. To obtain the optimum load values prior to voltage instability occurrence Evolutionary Programming (EP) technique is introduced. IEEE (30-...

Abdul Rahman Minhat; Ismail Musirin; Muhammad Murtadha Othman

2008-01-01

373

Effect of the disinfection technique on the linear dimensional stability of dental impression materials.  

Science.gov (United States)

The purpose of this study was to evaluate the dimensional stability of heavy and light bodied condensation silicones after immersion in disinfectant solution for 10 or 20 minutes. The impression materials were Optosil Comfort and Xantopren VL Plus and the disinfectant solutions were 1% sodium hypochlorite and 2% glutaraldehyde. Impressions were made on a perforated stainless steel tray, according to the American Dental Association specification No. 19, adding up to a total of 50 samples. The double mixing method (one time, two viscosities) was used. Impressions were removed from the roulette block after 7 minutes to ensure complete curing and then immersed in the solutions. Impressions not submitted to treatment composed the control group. After these steps, the impressions were removed from the solution, rinsed in running water and air-dried. Three-dimensional measurements were calculated using an optic microscope graduated at 0.001 mm. The two-way ANOVA indicated no differences (p>0.05) for any combination between variables. The results showed that the solution studied can be safely used to disinfect condensation silicone in clinical prosthodontic procedures. PMID:21049261

Silva, Sávio Marcelo Leite Moreira da; Salvador, Milton Carlos Gonçalves

2004-09-01

374

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)

375

Thermodynamic stability of Nd2TeO6 by transpiration technique  

International Nuclear Information System (INIS)

Vapour pressure of TeO2(g) over Nd2TeO6/Nd2O3 was measured by the transpiration technique over the temperature range 1408 -1541K, using a thermal analyzer. The measured vapour pressures could be represented by the expression log p (Pa) (± 0.04) = 17.39- 24559/ T(K). From the measured partial pressure of TeO2 (g) , the standard Gibbs energy of formation of Nd2TeO6 was determined to be, DGfo (Nd2TeO6, s) (± 5.0 kJ mol-l) -2358.5+ 0.62723 T (K)

376

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

Energy Technology Data Exchange (ETDEWEB)

Most of the ground stability analysis on the subsidence prone areas used to be performed through the conventional routine work which consist of a geological survey, a review of the ragged mining map, a trace-investigation on the surface subsidence, a coring job on the prone areas, a rock mass classification, and a two dimensional numerical analysis. Through the above works, we could analyze the stability problems of a surface structure and the tendency of a surface subsidence. However so many problems have been pointed out during the analysis of the subsidence problem owing to the lack of quantitative data in geological survey, the unreliability of the input data for numerical analysis. Also new techniques for ground stability on subsidence area which can replace the conventional passive method are requested among the civil and mining engineers for the safety control of the surface structure including the road and tunnel. In this study, the basic mechanism for the surface subsidence was surveyed first, and the proper input data for the two and three dimensional numerical analysis was selected. And these results were applied to Si-Heung Mine. According to the two dimensional numerical analysis, there is no possibility of surface subsidence even though tension failure was developed up to the region three times to the height of the cavity. Meanwhile the existing data for joints and the ground water was re-evaluated in order to analyze their effects on the subsidence. If we can recognize the characteristics of the spatial data on them in the future, the effect of the joint and ground water on the subsidence can be found out more precisely through the combination with GIS. Finally a finite difference numerical method was applied to Si-Heung Mine in the three dimension. But it was revealed that there are some problems in the three dimensional technique. In other words, it is difficult to obtain the exact spatial coordinates of the cavity, and the researcher should have an excellent modelling techniques and a concept for soil and rock mechanics. (author). 7 refs., 4 tabs., 60 figs.

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

1997-12-01

377

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.)

378

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

International Nuclear Information System (INIS)

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

379

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2005-06-05

380

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)

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

Baghdadi, Majid; Shemirani, Farzaneh

2009-02-23

381

Improved oral absorption and chemical stability of everolimus via preparation of solid dispersion using solvent wetting technique.  

Science.gov (United States)

The aim of this study was to improve the physicochemical properties and oral absorption of poorly water-soluble everolimus via preparation of a solid dispersion (SD) system using a solvent wetting (SW) technique. The physicochemical properties, drug release profile, and bioavailability of SD prepared by SW process were also compared to SD prepared by the conventional co-precipitation method. Solid state characterizations using scanning electron microscopy, particle size analysis and X-ray powder diffraction indicated that drug homogeneously dispersed and existed in an amorphous state within the intact polymeric carrier. Whereas, a film-like mass was obtained by a co-precipitation method and further pulverization step was needed for tabletization. The drug release from the SD tablet prepared by SW process at a ratio of drug to hydroxypropyl methylcellulose of 1:15 was markedly higher than the drug alone and equivalent to the marketed product (Afinitor(®), Novartis Pharmaceuticals), a SD tablet prepared by co-precipitation method, archiving over 75% the drug release after 30 min. At the accelerated (40°C/75% R.H.) and stress (80°C) stability tests, the novel formula was more stable than drug powder and provided comparable drug stability with the commercially available product, which contains a potentially risky antioxidant, butylated hydroxyl toluene. The pharmacokinetic parameters after single oral administration in beagles showed no significant difference (P>0.01) between the novel SD-based tablet and the marketed product. The results of this study, therefore, suggest that the novel SD system prepared by the solvent wetting process may be a promising approach for improving the physicochemical stability and oral absorption of the sirolimus derivatives. PMID:25003829

Jang, Sun Woo; Kang, Myung Joo

2014-10-01

382

In-plane strain measurements on a microscopic scale by coupling digital image correlation and an in situ SEM technique  

International Nuclear Information System (INIS)

The purpose of this paper is to present a method based on the correlation of digital images obtained on a microscopic scale. A specific grainy pattern has been developed. The use of the scanning electron microscopy (SEM) allowed the determination of full-field 2D displacements on an object surface with a spatial resolution of about 1 ?m. Validation tests were performed in order to quantify performances and limits of this method. An example of its application is presented for a Ti-6Al-4V titanium alloy. Results show that it is possible to obtain in-plane displacement values on the object surface with efficient spatial resolution and accuracy. Thus, such a technique can be used to highlight on a relevant scale the role of the microstructure in material deformation processes

383

[Pilon fractures : Part 2: Repositioning and stabilization technique and complication management].  

Science.gov (United States)

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

Krettek, C; Bachmann, S

2015-02-01

384

DEVELOPMENT, CHARACTERIZATION & STABILIZATION OF POORLY WATER SOLUBLE DRUGS UTILIZING SOLID DISPERSION TECHNIQUES BY USING ? - CYCLODEXTRIN  

Directory of Open Access Journals (Sweden)

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.

Rakesh Singh

2013-01-01

385

Surgical technique: hemi-extensor carpi radialis brevis tenodesis for stabilizing the midcarpal joint in Ehlers-Danlos syndrome.  

Science.gov (United States)

Patients with the hypermobility type of Ehlers-Danlos (EDS-HT) often complain of wrist pain, usually originating from subluxations. As a result of the laxity, wrist function in these patients can be highly limited. This paper presents a surgical technique that stabilizes the lunocapitate joint with the use of an extensor carpi radialis brevis strip. Five patients with confirmed EDS-HT were treated with an extensor carpi radialis brevis tenodesis for their midcarpal instability. Two patients presented with complications following surgery, one major and one minor. This paper presents a potentially satisfactory surgical solution to recurrent midcarpal instability in EDS-HT patients and demonstrates that the use of an autologous tendon might be feasible in spite of a background of abnormal collagen metabolism. PMID:25194773

Krijgh, David D; Harley, Oliver J; Hovius, Steven E; Coert, J Henk; Walbeehm, Erik T

2014-10-01

386

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.

387

Precise and efficient ex situ technique for determining compositions and growth rates in molecular-beam epitaxy grown semiconductor alloys  

International Nuclear Information System (INIS)

A technique based on the principle of coupling an evanescent wave via a prism into a semiconductor thin film has been used to determine simultaneously the composition and the thickness of II-VI semiconductor ternary alloys. This approach, which determines the indices of refraction n with high precision (at least 0.1%), and also concurrently determines the epilayer thicknesses with an uncertainty of less than 0.5%, has been applied to a series of molecular-beam epitaxy grown ternary alloy families; Zn1-xCdxSe, Zn1-xMgxSe, Zn1-xBexSe, Zn