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1

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

Energy Technology Data Exchange (ETDEWEB)

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 CO{sub 2}, alkanes and alkenes species at temperatures above 200 deg. C. The interlayer spacing collapsed after completed degradation of the intercalated surfactants.

Kooli, Fethi [Department of Chemistry, Taibah University, P.O. Box 30002, Al-Madinah Al-Munawwarah (Saudi Arabia)], E-mail: fkooli@taibahu.edu.sa

2009-03-20

2

A combined multi-technique in situ approach used to probe the stability of iron molybdate catalysts during redox cycling  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A setup combining a number of techniques (WAXS, XANES and UV–Vis) has been used to probe the stability of an iron molybdate catalyst during redox cycling. The catalyst was first reduced under anaerobic methanol/helium conditions, producing formaldehyde and then regenerated using air. Although in this test-case the catalyst and conditions differ from that of a commercial catalyst bed we demonstrate how such a setup can reveal new information on catalyst materials. In particular we observe th...

O’brien, Matthew G.; Beale, A. M.; Jacques, S. D. M.; Weckhuysen, B. M.

2009-01-01

3

In situ containment and stabilization of buried waste  

Energy Technology Data Exchange (ETDEWEB)

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

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

1992-11-01

4

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1997-12-31

5

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

6

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1992-11-01

7

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

8

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

9

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

10

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

11

In situ tooth replica custom implant: rationale, material, and technique.  

Science.gov (United States)

This study introduced a new concept of an in situ, custom-made, tooth replica dental implant. It was obtained by injecting a self-set, nonresorbable polymer type bone graft substitute into the tooth socket after extraction. Based on its cited properties, new composite bone cement Cortoss was suggested. The properties were reviewed and evaluated. The technique of application was described with a simulation model presented that appeared simple. Apparently, immediate duplication of tooth anatomy was achieved; thus, the concept might have the potentials of spontaneous adaptation and stabilization, preservation of alveolar bone, increasing implant-bone surface area, better load distribution, and bone stimulation. Modifications were also described to manage cases of resorbed alveolar bone as well as long-standing extracted teeth. Investigations were still required to assess the performance of the material and if modifications would be needed. PMID:20545544

Ghuneim, Wael Aly

2010-01-01

12

40 CFR 1065.195 - PM-stabilization environment for in-situ analyzers.  

Science.gov (United States)

... PM-stabilization environment for in-situ analyzers...195 Protection of Environment ENVIRONMENTAL PROTECTION...CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING... PM-stabilization environment for in-situ...

2010-07-01

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

MRI: stability of three supervised segmentation techniques.  

Science.gov (United States)

Supervised segmentation methods from three families of pattern recognition techniques were used to segment multispectral MRI data. Studied were the maximum likelihood method (MLM), k-nearest neighbors (k-NN), and a back-propagation artificial neural net (ANN). Performance was measured in terms of execution speed, and stability for the selection of training data, namely, region of interest (ROI) selection, and interslice and interpatient classifications. MLM proved to have the smallest execution times, but demonstrated the least stability. k-NN showed the best stability for training data selection. To evaluate the segmentation techniques, multispectral images were used of normal volunteers and patients with gliomas, the latter with and without MR contrast material. All measures applied indicated that k-NN provides the best results. PMID:8423729

Clarke, L P; Velthuizen, R P; Phuphanich, S; Schellenberg, J D; Arrington, J A; Silbiger, M

1993-01-01

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

Review of subsidence and stabilization techniques  

International Nuclear Information System (INIS)

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

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 Community Control of the Stability of Bioreduced Uranium  

Energy Technology Data Exchange (ETDEWEB)

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

White, David C.

2005-06-01

19

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

International Nuclear Information System (INIS)

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

20

Rapid in situ detection of chromosome 21 by PRINS technique  

Energy Technology Data Exchange (ETDEWEB)

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

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

1995-05-08

 
 
 
 
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

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

Science.gov (United States)

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(-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. PMID:21609136

MacCuspie, Robert I; Allen, Andrew J; Hackley, Vincent A

2011-06-01

23

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

24

Engineering feasibility analysis for in-situ stabilization of Canonsburg residues  

International Nuclear Information System (INIS)

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

25

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

Energy Technology Data Exchange (ETDEWEB)

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

1982-01-01

26

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

27

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

28

COMPARISON OF DIFFERENT TECHNIQUES FOR DESIGN OF POWER SYSTEM STABILIZER  

Directory of Open Access Journals (Sweden)

Full Text Available The major problem in power system operation is related to small signal instability caused by insufficient damping in the system. The most effective way of countering this instability is to use auxiliary controllers called power system stabilizers, to produce additional damping during low frequency oscillations in the system. Heffron-Phillip’s Model of a synchronous machine is commonly used in small signal stability analysis. Different techniques for designing of power system stabilizer is proposed for Modified Heffron-Phillip’smodel, the parameters of the power system stabilizer has been tuned by the three ways , linear quadratic power system stabilizer, genetic algorithm power system stabilizer and proposed power system stabilizer. The efficiency of the proposed design technique and the performance of the stabilizer has been evaluated over a range of operating and system conditions and the performance of the proposed controller is much better than the linear quadratic power system stabilizer and genetic algorithm based power system stabilizer.

M. Ravindra Babu,

2011-05-01

29

Soil surface stabilization using an in situ plutonium coating techniuqe at the Nevada Test Site  

International Nuclear Information System (INIS)

The Hazardous Waste Remedial Actions Program (HAZWRAP), in collaboration with the University of Nevada at Reno (UNR), has developed and is investigating an in situ plutonium treatment for soils at the Nevada Test Site (NTS). The concept, conceived by Dr. T. Tamura and refined at HAZWRAP, was developed during the Nevada Applied Ecology Program investigation. In analyzing for plutonium in soils, it was noted that the alpha emanation of plutonium was greatly attenuated if traces of iron or manganese oxides were present in the final electroplating stage. The technique would reduce resuspension of alpha particles into the air by coating the contaminants in soils in situ with an environmentally compatible, durable, and nontoxic material. The coating materials (calcium hydroxide, ferrous sulfate) reduce resuspension by providing a cementitious barrier against radiation penetration while retaining soil porosity. This technique not only stabilizes plutonium-contaminated soils, but also provides an additional protection from worker exposure to radiation during remediation activities. Additionally, the coating would decrease the water solubility of the contaminant and, thus, reduce its migration through soil and uptake by plants

30

In Situ Techniques for Mineralogy and Geochemistry of Small Bodies  

Science.gov (United States)

In situ exploration of planetary surfaces employs multiple techniques that, when used together, yield important information about their formation histories and evolution. Combined geochemistry and mineralogy measurements reveal the phases present, their composition, morphology, and isotope ratios of constituents. Small and primitive bodies often present a special case where little to no compositional information has been obtained from ground-based or remote measurements. For example, Trojan asteroids and other D-type objects as well as Phobos and Deimos exhibit relatively featureless reflectance spectra as obtained by remote measurements. Yet samples of primitive material in the meteorite collection (e.g. Allende) reveal a fine grained structure with many phases and a wealth of chemical information. On-surface measurements are therefore a necessary component for understanding the origins of these solar system bodies. We will present measurement techniques that could provide microscopic mineralogy and isotope geochemistry. We will discuss instrumentation and measurements relevant to small body exploration - focusing more specifically on our recent results from the techniques of microscopic time-resolved Raman spectroscopy, Laser Induced Breakdown Spectroscopy (LIBS), and Tunable Laser Spectroscopy (TLS). The research described here was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (NASA). This work was performed in part at the California Institute of Technology for the Keck Institute for Space Studies, which is funded by the W. M. Keck Foundation.

Blacksberg, J.; Rossman, G. R.; Webster, C. R.

2012-12-01

31

Thermal stability of BNCT neutron production target synthesized by in-situ lithium deposition and ion implantation  

International Nuclear Information System (INIS)

To testify thermal stability of the BNCT neutron target synthesized by in-situ lithium deposition and ion implantation, laser heating test of the Li3N/Li/Cu tri-layered target was conducted in high vacuum chamber of 10-6 Pa and thermal stability of the tri-layered target was characterized by X-ray photoelectron spectroscopy. The following conclusions were derived; (1) The Li3N/Li/Cu tri-layered target with very low oxide and carbon contamination was synthesized by in-situ lithium deposition and ion implantation techniques without H2O and O2 additions. (2) The starting temperature of evaporation of the Li3N/Li/Cu tri-layered target increased by 120 K compared to that of the Li/Cu target and (3) frequent repair synthesis of the damaged Li3N/Li/Cu tri-layered target caused by evaporation is possible. (author)

32

Thermal stability of BNCT neutron production target synthesized by in-situ lithium deposition and ion implantation  

International Nuclear Information System (INIS)

To testify thermal stability of the BNCT neutron target synthesized by in-situ lithium deposition and ion implantation, laser heating test of the Li3N/Li/Cu tri-layered target was conducted in high vacuum chamber of 10-6 Pa and thermal stability of the tri-layered target was characterized by X-ray photoelectron spectroscopy. Following conclusions were derived; (1) The Li3N/Li/Cu tri-layered target with very low oxide and carbon contamination was synthesized by in-situ lithium deposition and ion implantation techniques without H2O and O2 additions, (2) The starting temperature of evaporation of the Li3N/Li/Cu tri-layered target increased by 120 K compared to that of the Li/Cu target, and (3) Frequent repair synthesis of the damaged Li3N/Li/Cu tri-layered target caused by evaporation is possible. (author)

33

In situ stabilization of toxic metals in polluted soils using phosphates: theoretical prediction and experimental verification  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The in situ (in place) immobilization of toxic metals, using inexpensive “reactive” amendments, is considered as a simple and cost-effective approach for the treatment of soils, contaminated by the presence of heavy metals, when these soils are difficult or costly to be removed and treated ex situ. Several application studies have demonstrated that the stabilization of contaminated soils and groundwaters by the addition of apatite minerals has the potential to be a successful and widely a...

Raicevic, S.; Kaludjerovic-radoicic, T.; Zouboulis, A. I.; ???????????, ?. ?.

2009-01-01

34

Comparison of In Situ Polymerization and Solution-Dispersion Techniques in the Preparation of Polyimide/Montmorillonite (MMT Nanocomposites  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, Polyimide/Montmorillonite Nanocomposites (PI/MMT NCs, based on aromatic diamine (4-Aminophenyl sulfone (APS and aromatic dianhydride (3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA were prepared using in situ polymerization and solution-dispersion techniques. The prepared PI/MMT NCs films were characterized by X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FT-IR, transmission electron microscopy (TEM and thermogravimetric analysis (TGA. The XRD results showed that at the content of 1.0 wt % Organo Montmorillonite (OMMT for two techniques and 3.0 wt % OMMT for the in situ polymerization technique, the OMMT was well-intercalated, exfoliated and dispersed into polyimide matrix. The OMMT agglomerated when its amount exceeded 10 wt % and 3.0 wt % for solution-dispersion and in situ polymerization techniques respectively. These results were confirmed by the TEM images of the prepared PI/MMT NCs. The TGA thermograms indicated that thermal stability of prepared PI/MMT NCs were increased with the increase of loading that, the effect is higher for the samples prepared by in situ polymerization technique.

Yadollah Gharayebi

2011-09-01

35

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

36

Fast axisymmetric stability calculations using variational techniques  

International Nuclear Information System (INIS)

A procedure for treating the axisymmetric (n = 0) stability of diverted plasmas in the presence of arbitrary, but toroidally symmetric, structures and active feedback circuits has been developed and implemented as a module in the TEQ free-boundary equilibrium code. This procedure is based on a variational solution of the ideal MHD normal mode equations. Inertia is ordered small but provides a constraint to allow the calculation of the poloidal and toroidal components of the plasma displacement. Feedback based on flux loop measurements is handled by introducing an adjoint system into the variational principle. Approximately 200 trial functions for the radial component of the plasma displacement and 200 magnetic surfaces are employed to obtain highly accurate estimates of the passive growth rate and the non-rigid eigenfunction. Nevertheless, the method is extremely fast: typically 10-20 sec of Cray 2 CPU time are required to analyze a realistic tokamak configuration. This speed, along with the direct coupling to the MHD equilibrium solver, allows interactive investigations of tokamak axisymmetric stability. Benchmarks with TSC and GATO are presented along with parameter scans for ITER and BPX. The results emphasize the importance of considering non-rigid mode effects which for ITER, yield higher nominal growth rates (non-rigid: 45 Hz, rigid: 25 Hz) and atypical internal inductance dependence (smaller li more unstable)

37

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

38

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

39

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

40

Other in situ bioremediation techniques; literature study in the framework of the project "In Situ Bioremediation" in Asten  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In developing in situ remediation most of the focus used to be on techniques using infiltration water to supply oxygen to the location. Later, techniques were developed in which soil was flushed with air to enhance the oxygen availability to microorganisms. The aim of the study reported here was to examine the results of remediation where soil is flushed with air, as reported in the literature, and to examine the costs of such systems. In the study these techniques were com...

Aj, Scheuter

2007-01-01

 
 
 
 
41

Possibilities of MgB2/Cu Wires Fabricated by the in-situ Reaction Technique  

CERN Document Server

The superconducting properties of copper-sheathed MgB2 wires fabricated by conventional powder-in-tube techniques and the in-situ reaction procedure are analysed. The influence of the processing conditions and initial (1+x)Mg + 2B (x = 0, 0.1, 0.2) proportions of the precursors on the critical current values of the wires have been studied. In particular, the limits of the available temperatures and times for heat treatments imposed by the chemical reaction between Mg and Cu, and their effect on the superconducting properties of the wires, are discussed. The analysis includes the study of the sample microstructure and phase composition as well as of the critical current temperature and field dependences. The wires show high thermal stability during direct transport measurements and carry a critical current density of 1.3x109 A/m2 at 15 K in the self-field for optimised processing conditions.

Martínez, E

2003-01-01

42

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

43

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

Energy Technology Data Exchange (ETDEWEB)

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

Kalb,P.D.; Milian, L.

2008-03-01

44

In-situ subsurface density estimations using a seismic technique  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A new geophysical method was developed to satisfy a need for in-situ density measurements. Various situations, such as a gravity dam wall requires that density measurements should be done without damage to the structure. The sample volume should also not be that large in order to be sensitive enough for variations. This method measures the in-situ density of the weathered layer and other man made structures, using seismic waves in three directions. The seismic waves utilize...

Fourie, Christoffel Johannes Stephanus

2009-01-01

45

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...

46

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...

47

TESTING TECHNIQUE OF MOTOR PETROL PHYSICAL STABILITY ESTIMATION AND FORECASTING  

Directory of Open Access Journals (Sweden)

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

Sergey V. Boychenko

2009-04-01

48

Stabilization of microorganisms for in situ degradation of toxic chemicals  

International Nuclear Information System (INIS)

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

49

Hp-?-CD-Voriconazole In Situ Gelling System for Ocular Drug Delivery: In Vitro, Stability, and Antifungal Activities Assessment  

Science.gov (United States)

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

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

2013-01-01

50

In situ molecular NMR picture of bioavailable calcium stabilized as amorphous CaCO? biomineral in crayfish gastroliths.  

Science.gov (United States)

Bioavailable calcium is maintained by some crustaceans, in particular freshwater crayfish, by stabilizing amorphous calcium carbonate (ACC) within reservoir organs--gastroliths, readily providing the Ca(2+) needed to build a new exoskeleton. Despite the key scientific and biomedical importance of the in situ molecular-level picture of biogenic ACC and its stabilization in a bioavailable form, its description has eluded efforts to date. Herein, using multinuclear NMR, we accomplish in situ molecular-level characterization of ACC within intact gastroliths of the crayfish Cherax quadricarinatus. In addition to the known CaCO(3), chitin scaffold and inorganic phosphate (Pi), we identify within the gastrolith two primary metabolites, citrate and phosphoenolpyruvate (PEP) and quantify their abundance by applying solution NMR techniques to the gastrolith "soluble matrix." The long-standing question on the physico-chemical state of ACC stabilizing, P-bearing moieties within the gastrolith is answered directly by the application of solid state rotational-echo double-resonance (REDOR) and transferred-echo double-resonance (TEDOR) NMR to the intact gastroliths: Pi and PEP are found molecularly dispersed throughout the ACC as a solid solution. Citrate carboxylates are found < 5 ? from a phosphate (intermolecular CP distance), an interaction that must be mediated by Ca(2+). The high abundance and extensive interactions of these molecules with the ACC matrix identify them as the central constituents stabilizing the bioavailable form of calcium. This study further emphasizes that it is imperative to characterize the intact biogenic CaCO(3). Solid state NMR spectroscopy is shown to be a robust and accessible means of determining composition, internal structure, and molecular functionality in situ. PMID:21873244

Akiva-Tal, Anat; Kababya, Shifi; Balazs, Yael S; Glazer, Lilah; Berman, Amir; Sagi, Amir; Schmidt, Asher

2011-09-01

51

In-situ subsurface density estimations using a seismic technique  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A new geophysical method was developed to satisfy a need for in-situ density measurements. Various situations, such as a gravity dam wall requires that density measurements should be done without damage to the structure. The sample volume should also not be that large in order to be sensitive enough for variations. This method measures the in-situ density of the weathered layer and other man made structures, using seismic waves in three directions. The seismic waves utilized are P-waves and S...

Fourie, Christoffel Johannes Stephanus

2008-01-01

52

Polyphosphate Remediation Technology for In-Situ Stabilization of Uranium  

Energy Technology Data Exchange (ETDEWEB)

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

Wellman, Dawn M.; Pierce, Eric M.; Bacon, Diana H.; Fruchter, Jonathan S.; Vermeul, Vincent R.; Webb, Samuel M.

2009-03-01

53

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

54

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

Energy Technology Data Exchange (ETDEWEB)

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.

Allan, M.L.; Kukacka, L.E. [Brookhaven National Lab., Upton, NY (United States). Energy Efficiency and Conservation Div.

1994-10-01

55

The construction technique of borehole for in-situ leaching process  

International Nuclear Information System (INIS)

The construction of borehole for in-situ leaching process is one of the key techniques of in-situ leaching uranium. There are many problems yet to be solved in borehole construction design, slope deviation of borehole, drivepipe joint sealing, borehole cementing and flushing. The construction process must be normalized and supervised so that the borehole quality can be ensured

56

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)

57

Techniques for the In Situ Analysis of Titan Lake Fluids  

Science.gov (United States)

Titan’s lakes are a primary target for future Titan exploration. We present two successfully tested in situ methods to analyze Titan lake fluids: 1) fiber optic probes, and 2) solid phase micro-extraction (SPME) fibers for preconcentration of analytes.

Hodyss, R.; Malaska, M. J.; Beauchamp, P. M.

2014-02-01

58

Soil mixing for the improvement of in situ remediation techniques  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Die Sanierung von Boden- und Grundwasserkontaminationen durch in situ Maßnahmen (meist eine Spülung des Untergrundes mit Wasser oder Luft) hat sich in sehr vielen Fällen als uneffektiv erwiesen. Ursache hierfür sind die physikalisch-chemischen Eigenschaften der Schadstoffe und die Heterogenität des Untergrundes, die insbesondere die Verteilung der Schadstoffe bestimmt. Diese wiederum beeinflußt in hohem Maße die Schadstoff-Freisetzungsraten, die entscheidend für die Sanierungseffizien...

Klein, Rainer

1998-01-01

59

Simple Fluorescent Micronucleus Assay-combination of Hg-banding Technique and In situ Hybridisation  

Directory of Open Access Journals (Sweden)

Full Text Available Recent development in cytogenetic and molecular techniques, particularly combination of cytochalasin B method and fluorescence In situ hybridisation (FISH now allow sensitive identification of clastogenic versus aneugenic events. To simplify the fluorescence micronucleus assay a technique based on combination of hypotonic banding and In situ hybridisation with pancentromeric probe (SO-?AllCen is described. This work demonstrates more comfortable, easier and faster way to perform fluorescent micronucleus test

Gordana Joksi

2001-01-01

60

Power dependence of NF3 plasma stability for in situ chamber cleaning  

International Nuclear Information System (INIS)

We investigated the stability of NF3 plasmas for in situ chamber cleaning in a production plasma-enhanced chemical vapor deposition reactor. An rf power threshold, normalized by NF3 molar number (Pnn) and NF3 flow rate (Pnf), is observed to be PnnPnf=39 (W/? mol)(W/sccm) for stable plasmas with high NF3 destruction efficiency. This is rationalized by the energy required to maintain sufficient electron-ion pair creation in an electronegative discharge

 
 
 
 
61

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

Science.gov (United States)

Back and forth: The CO2 /N2 trigger of a switchable surfactant (neutral amidine/cationic amidinium) was transferred to mineral nanoparticles through in?situ hydrophobization in water. Switchable oil-in-water Pickering emulsions that entail a CO2 /N2 trigger were obtained by using negatively charged silica nanoparticles and a trace amount of the switchable surfactant as the stabilizer. PMID:24123666

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

2013-11-18

62

Indigenous development of A-15 superconductors through in situ technique  

International Nuclear Information System (INIS)

The preliminary results obtained on the in situ Cu-Nb3Sn composite superconductors are reported. Two phase alloys of Cu-Nb (15 to 30 at.%) have been prepared by arc melting and rolled/drawn to fine wires and tapes without intermediate annealing. Prior to tin coating, these specimens were characterized for their T/sub c/ and J/sub c/ values. A mid point T/sub c/ of 8.8K and a self field overall J/sub c/ of 2.5 x 105 A.cm-2 (4.2K) have been obtained for specimens with 20 to 30 at.% Nb. The rolled Cu-Nb tapes with well aligned filaments show critical current anisotropy with the magnetic field direction. Cu-Nb3Sn composite wires have been prepared by coating these wires with varying amounts of tin and heat treating them at 5500C for various periods. The best specimen has a T/sub c/ (midpoint) of 17.5K and a J/sub c/ of 3 x 105 A.cm-2 at 6T, 4.2K and 3 x 104 A.cm-2 at 12T, 4.2K. These values compare well with the published data. Studies are continuing for the optimization of various parameters. In situ Cu-V3Ga composite wires have also been prepared and are presently begin characterized

63

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

Science.gov (United States)

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. PMID:15885755

Raicevic, S; Wright, J V; Veljkovic, V; Conca, J L

2006-02-15

64

In-situ characterization of dispersion stability of WO3 nanoparticles and nanowires  

International Nuclear Information System (INIS)

The stability of tungsten trioxide (WO3) suspensions in various common polar solvents such as water, acetone, isopropanol (IPA), ethanol, 1-methoxy-2-propanol (1M-2P) and N,N-dimethylformamide (DMF) was investigated. The morphology of WO3 aggregates formed by irregular nanoparticles (d ? 40 nm, with 1 ?m nominal diameter compact aggregates) and by nanowires of different types (uneven, single or bundled in diameter) and dimensions (nominal lengths of 2, 4, 6, and 10 ?m) were described by means of the small angle static light scattering and the elliptically polarized light scattering (EPLS) techniques. Aggregation of low aspect ratio (bundled) 2 ?m nanowires monitored through the change in spatial extent of the aggregate was found to be minimal (i.e., radius of gyration, Rg ? 1.8-2.2 ?m in 1-methoxy-2-propanol), with a minimal change in aggregate structure (i.e., fractal dimension, Df ? 1.8-1.9 in 1-methoxy-2-propanol) in a time period of about 1 week. Fractal dimension was found to be the lowest for the low aspect ratio nanowires when suspended in N,N-dimethylformamide (Df ? 1.4). Aggregates of very high aspect ratio single nanowires (L/D ? 250 with 10 ?m nominal length) were also observed to form stable dispersions in a period of about a week. Aggregate structures that would lead to observed fractal dimensions were proposed. Information on how well inorganic nanowires are dispersed in various solvents is based singly on the time consuming and intrusive advanced microscopy analyses (such as SEM and TEM) in the literature, and without any reference to the underlying structures. To our knowledge, this study is the first attempt for in-situ description of the underlying causes, such as aggregate morphologies, aggregation rates and solvent types, of the observed dispersion and sedimentation behaviors of inorganic nanowires that were not subjected to any surface treatment or functionalization

65

In-situ synthesis and magnetically stabilized Kyropoulos growth of undoped indium phosphide  

International Nuclear Information System (INIS)

This paper reports that the Kyropoulos growth technique has been combined with in-situ synthesis to yield high purity undoped crystals of 300 to 700 gm charges of InP. Etched wafers show a uniform dislocation density across 70 mm diameter in contrast with the W pattern created by LEC. Use of an axial magnetic field in Kyropoulos growth reduces the dislocation density by an order of magnitude, to 1 x 104cm-2. by combining Kyropoulos growth with in-situ synthesis of the indium phosphide, high mobility (4.6 x 104 at 77 C) undoped single crystals have been obtained

66

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

67

In Situ Techniques for Monitoring Electrochromism: An Advanced Laboratory Experiment  

Science.gov (United States)

This experiment employs current technology to enhance and extend existing lab content. The basic principles of spectroscopic and electroanalytical techniques and their use in determining material properties are covered in some detail in many undergraduate chemistry programs. However, there are limited examples of laboratory experiments with in…

Saricayir, Hakan; Uce, Musa; Koca, Atif

2010-01-01

68

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

69

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

International Nuclear Information System (INIS)

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

70

In-situ film thickness measurements using acoustic techniques  

Science.gov (United States)

Process monitoring and control of semiconductor fabrication parameters like film thickness are important issues limited at the present time by a lack of adequate sensors. In this paper we outline the limitations of current film thickness technology and propose two new methods for nondestructive insitu film thickness process monitoring: acoustic time domain reflectometry (TDR) and acoustic reflection coefficient phase measurements. Theoretical calculations and experimental measurements of different metal films are used to demonstrate the viability of these novel techniques.

Bhardwaj, Sanjay; Khuri-Yakub, Butrus T.

1991-03-01

71

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

72

Dispersion polymerization of methyl acrylate in nonpolar solvent stabilized by block copolymers formed in situ via the RAFT process.  

Science.gov (United States)

The free-radical dispersion polymerization of methyl acrylate (MA) in isododecane was carried out in the presence of a poly(2-ethylhexyl acrylate) macromolecular RAFT (reversible addition-fragmentation chain transfer) agent bearing a trithiocarbonate reactive group in the middle of the chain (P2EHA-TTC). The presence of the trithiocarbonate function was crucial for the synthesis of monodisperse colloidal poly(methyl acrylate) (PMA) particles stabilized by the P2EHA segments. The hydrodynamic diameters ranged from 100 to 300 nm, using particularly low amounts of the macro(RAFT agent) (1-6 wt % vs. MA) in dispersion polymerizations carried out at 20 wt % solids content. As shown by 2D liquid chromatography, P2EHA-b-PMA or P2EHA-b-PMA-b-P2EHA block copolymers formed in situ at the early stage of the dispersion polymerization due to the reversible transfer process and played the role of particle stabilizer. The glass-transition temperature of the derived polymer films was not affected by the low amount of the chosen macromolecular stabilizer and the mechanical properties were mainly those of PMA, which makes the technique very attractive for coating applications. PMID:20356189

Houillot, Lisa; Bui, Chuong; Farcet, Céline; Moire, Claudine; Raust, Jacques-Antoine; Pasch, Harald; Save, Maud; Charleux, Bernadette

2010-02-01

73

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

Science.gov (United States)

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

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

2008-09-01

74

Localized in-situ polymerization on graphene surfaces for stabilized graphene dispersions  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We demonstrate a novel in situ polymerization technique to develop localized polymer coatings on the surface of dispersed pristine graphene sheets. Graphene sheets show great promise as strong, conductive fillers in polymer nanocomposites; however, difficulties in dispersion quality and interfacial strength between filler and matrix have been a persistent problem for graphene-based nanocomposites, particularly for pristine graphene. To address this problem, a physisorbed pol...

Das, Sriya; Wajid, Ahmed S.; Shelburne, John L.; Liao, Yen-chi; Green, Micah J.

2010-01-01

75

Emissions from sanitary landfilling - long-term emissions, sealing systems, in situ stabilization and aftercare  

Energy Technology Data Exchange (ETDEWEB)

The long-term behaviour of landfills, which are in operation or already closed, is an important question to design landfill technology and the aftercare. Results from many investigations show that emissions into the leachate phase have to be expected for many decades or even centuries to come. That is one reason why pretreatment of municipal solid waste has now to be carried out in Germany. Moreover the in situ stabilization of old landfills aims at a lasting reduction of pollutant emissions from untreated deposited waste. Likewise, duration and expenditure of post-closure measures like the surface sealing system and the collection and treatment of emissions shall be diminished. The aeration of the landfill body for an accelerated stabilization of biologically available organic components turns out to be a reasonable and effective method to reach this objective. (orig.)

Heyer, K.U.; Hupe, K.; Stegmann, R.

2001-07-01

76

In-situ characterization of dispersion stability of WO{sub 3} nanoparticles and nanowires  

Energy Technology Data Exchange (ETDEWEB)

The stability of tungsten trioxide (WO{sub 3}) suspensions in various common polar solvents such as water, acetone, isopropanol (IPA), ethanol, 1-methoxy-2-propanol (1M-2P) and N,N-dimethylformamide (DMF) was investigated. The morphology of WO{sub 3} aggregates formed by irregular nanoparticles (d {approx} 40 nm, with 1 {mu}m nominal diameter compact aggregates) and by nanowires of different types (uneven, single or bundled in diameter) and dimensions (nominal lengths of 2, 4, 6, and 10 {mu}m) were described by means of the small angle static light scattering and the elliptically polarized light scattering (EPLS) techniques. Aggregation of low aspect ratio (bundled) 2 {mu}m nanowires monitored through the change in spatial extent of the aggregate was found to be minimal (i.e., radius of gyration, R{sub g} {approx} 1.8-2.2 {mu}m in 1-methoxy-2-propanol), with a minimal change in aggregate structure (i.e., fractal dimension, D{sub f} {approx} 1.8-1.9 in 1-methoxy-2-propanol) in a time period of about 1 week. Fractal dimension was found to be the lowest for the low aspect ratio nanowires when suspended in N,N-dimethylformamide (D{sub f} {approx} 1.4). Aggregates of very high aspect ratio single nanowires (L/D {approx} 250 with 10 {mu}m nominal length) were also observed to form stable dispersions in a period of about a week. Aggregate structures that would lead to observed fractal dimensions were proposed. Information on how well inorganic nanowires are dispersed in various solvents is based singly on the time consuming and intrusive advanced microscopy analyses (such as SEM and TEM) in the literature, and without any reference to the underlying structures. To our knowledge, this study is the first attempt for in-situ description of the underlying causes, such as aggregate morphologies, aggregation rates and solvent types, of the observed dispersion and sedimentation behaviors of inorganic nanowires that were not subjected to any surface treatment or functionalization.

Kozan, Mehmet [University of Kentucky, Department of Mechanical Engineering (United States); Thangala, Jyothish; Bogale, Rahel [University of Louisville, Department of Chemical Engineering (United States); Menguec, M. Pinar [University of Kentucky, Department of Mechanical Engineering (United States)], E-mail: menguc@engr.uky.edu; Sunkara, Mahendra K. [University of Louisville, Department of Chemical Engineering (United States)

2008-04-15

77

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

78

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

79

Application of in situ x-ray diffraction techniques in heterogenous catalytic systems  

International Nuclear Information System (INIS)

A broad range of techniques is available today for the characterisation of catalysts and the investigation of catalyst reaction mechanisms. However, only a limited number of those are suitable for in situ studies, i.e experiments performed in conditions mimicking or close as possible to real operating conditions. Various commercially and in-house developed in situ X-Ray diffraction (XRD) cells have been used to obtain information on the phase and structure of materials at the initial formation stage, activation methodology, calcination, reduction and carburization. A major advantage of the in situ X-ray cells is that it allows direct observations on the decomposition of precursors leading to various phases in a controlled environment, i.e. controlled temperature and pressure under specified gases. The cells can be operated both at high temperatures and high pressures, equipped with Position Sensitive Detector (PSD), feature which was used to study phase transformation occurring during the activation of various solids. In MoO3, XRD results provide detailed information on the hydrogen insertion into its lattice, followed by carburization providing good understanding on the mechanism in the solid transformation leading to the metastable MoC1-x phase. For the Bi-SnOx systems, the environmental cell coupled with XRD and PSD allow the design of activation procedure to obtain the active Bi2Sn2O7. The in situ XRD technique reveals crucial information on the initial stage of oxides formations prior to condensation reaction shown in MCM-41 and titania systems. In this presentation, discussions on general achievements and problems relating to the use of in situ XRD techniques as well as of specific examples selected to illustrate the use and potential of in situ XRD are made. It is not intended to be a review of the art but a highlight of the challenges which the catalytic and material scientists face when entering the avenue. (Author)

80

Instrumentation for in situ coal gasification: an assessment of techniques evaluated on the Hanna II experiment  

Energy Technology Data Exchange (ETDEWEB)

The Hanna II in-situ coal gasification experiment was conducted by the Laramie Energy Research Center during 1975 to 76. Sandia Laboratories designed, fielded, and evaluated variations of seven instrumentation techniques belonging to two general classes: (a) diagnostic techniques (thermal, in-seam gas sampling and pressure, and overburden tilt and displacement) to obtain data for process characterization and (b) remote monitoring techniques (electrical, passive acoustic, and induced seismic) being developed to provide a continuous, real-time map of the in-situ process for application in a process control system. Assessments of these techniques have been made with respect to feasibility, information obtainable, and possible future development and applications. In general, very positive assessments were obtained. Extensive thermocouple arrays, which incorporated special branched circuitry for data validation, provided the most detailed characterization of in-situ coal gasification yet obtained. The feasibility of in-seam gas sampling and pressure measurements was demonstrated and composition changes due to the advancing reaction front were detailed. The thermocouple circuits and gas sampling and pressure canisters are part of a diagnostic well specification now under development for general in-situ applications. Promising results were obtained for two remote monitoring techniques. Direct excitation electrical potential and a modified Schlumberger technique. Contour maps of potential data from a surface array showed the location and movement of the reaction at 300 ft depth. Mapping the source of process-related acoustic signals was shown to be feasible. Borehole-to-borehole induced seismic techniques were able to delineate the advance of the gasification process.

Northrop, D.A.; Beard, S.G.; Bartel, L.C.; Beckham, L.W.; Hommert, P.J.

1977-09-01

 
 
 
 
81

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

82

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

83

Occipitocervical contoured rod stabilization: Does it still have a role amidst the modern stabilization techniques?  

Directory of Open Access Journals (Sweden)

Full Text Available Background: The occipitocervical contoured rod (CR stabilization for use in craniovertebral junction (CVJ pathologies is an effective and economical technique of posterior fusion (PF. Aims: The various indications for CR in CVJ pathologies are discussed. Settings and Design: Retrospective analysis. Materials and Methods: Fifty-four patients (mean age: 31.02 ± 13.44 years; male: female ratio=5.75:1 who underwent CR stabilization are included. The majority had congenital atlantoaxial dislocation (AAD; n=50; two had CVJ tuberculosis; one each had rheumatoid arthritis and C2-3 listhesis, respectively. The indications for CR fusion in congenital AAD were associated Chiari 1 malformation (C1M (n=29; occipitalized C1 arch and/or malformed or deficient C1 or C2 posterior elements (n=9; hypermobile AAD (n=2; and, rotatory AAD (n=3. Contoured rod as a revision procedure was also performed in seven patients. Most patients were in poor grade (18 in Grade III [partial dependence for daily needs] and 15 in Grade IV [total dependence]; 15 patients were in Grade II [independent except for minor deficits] and six in Grade I [no weakness except hyperreflexia or neck pain]. Results: Twenty-four patients improved, 18 stabilized and six deteriorated at a mean follow-up (FU of 17.78 ± 19.75 (2-84 months. Six patients were lost to FU. In 37 patients with a FU of at least three months, stability and bony union could be assessed. Thirty-one of them achieved a bony fusion/ stable construct. Conclusions: Contoured rod is especially useful for PF in cases of congenital AAD with coexisting CIM, cervical scoliosis, sub-axial instability and/or asymmetrical facet joints. In acquired pathologies with three-column instability, inclusion of joints one level above the affected one by using CR, especially enhances stability.

Kalra Samir

2007-01-01

84

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

Directory of Open Access Journals (Sweden)

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

Shuang Cao

2014-06-01

85

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 (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

86

Synthesis of superhydrophobic silica nanofibrous membranes with robust thermal stability and flexibility via in situ polymerization  

Science.gov (United States)

Superhydrophobic silica nanofibrous membranes exhibiting robust thermal stability and flexibility were prepared by a facile combination of electrospun silica nanofibers and a novel in situ polymerized fluorinated polybenzoxazine (F-PBZ) functional layer that incorporated SiO2 nanoparticles (SiO2 NPs). By using F-PBZ/SiO2 NP modification, the pristine hydrophilic silica nanofibrous membranes were endowed with superhydrophobicity with a water contact angle (WCA) of up to 161°. Surface morphological studies have revealed that the wettability of resultant membranes could be manipulated by tuning the surface composition as well as the hierarchical structures. Quantitative fractal dimension analysis using the N2 adsorption method has confirmed the correlation between hierarchical roughness and WCA for the modified membranes. Furthermore, the as-prepared membranes exhibited high thermal stability (450 °C), good flexibility (0.0127 gf cm), and comparable tensile strength (2.58 MPa), suggesting their use as promising materials for a variety of potential applications in high-temperature filtration, self-cleaning coatings, catalyst carriers, etc., and also provided new insight into the design and development of functional nanofibrous membranes through F-PBZ modification.Superhydrophobic silica nanofibrous membranes exhibiting robust thermal stability and flexibility were prepared by a facile combination of electrospun silica nanofibers and a novel in situ polymerized fluorinated polybenzoxazine (F-PBZ) functional layer that incorporated SiO2 nanoparticles (SiO2 NPs). By using F-PBZ/SiO2 NP modification, the pristine hydrophilic silica nanofibrous membranes were endowed with superhydrophobicity with a water contact angle (WCA) of up to 161°. Surface morphological studies have revealed that the wettability of resultant membranes could be manipulated by tuning the surface composition as well as the hierarchical structures. Quantitative fractal dimension analysis using the N2 adsorption method has confirmed the correlation between hierarchical roughness and WCA for the modified membranes. Furthermore, the as-prepared membranes exhibited high thermal stability (450 °C), good flexibility (0.0127 gf cm), and comparable tensile strength (2.58 MPa), suggesting their use as promising materials for a variety of potential applications in high-temperature filtration, self-cleaning coatings, catalyst carriers, etc., and also provided new insight into the design and development of functional nanofibrous membranes through F-PBZ modification. Electronic supplementary information (ESI) available: Detailed chemical synthesis and structural confirmation of BAF-tfa, FT-IR results, and FE-SEM results. See DOI: 10.1039/c2nr32095a

Yang, Liping; Raza, Aikifa; Si, Yang; Mao, Xue; Shang, Yanwei; Ding, Bin; Yu, Jianyong; Al-Deyab, Salem S.

2012-09-01

87

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

Directory of Open Access Journals (Sweden)

Full Text Available 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. Crude protein degradability?s of mentioned cuts were 60.47, 63.08 and 58.07%, respectively. The gas productions of them at 96 h were 322.54, 295.21 and 300.32 mL g-1 DM respectively. The relationship between dry matter and gas production values for alfalfa cuts obtained about 0.89, 0.85 and 0.84 and for crude protein and gas production data achieved 0.87, 0.88 and 0.84, respectively. High correlation between in situ and gas production techniques indicated that in situ degradability?s values can be predicted from gas production data.

A. Taghizadeh

2008-01-01

88

Hepatic resection with in situ hypothermic perfusion is superior to other resection techniques.  

Science.gov (United States)

Through the years, liver resection and bleeding control techniques have progressively evolved. However, for liver tumors located unfavorably, the standard techniques are not suitable due to either failure to control the bleeding or to liver ischemia induced by prolonged interruption of perfusion. In this regard, total vascular exclusion (TVE) with in situ hypothermic perfusion is advantageous as it protects the parenchyma, achieves better vascular control and enables difficult vascular reconstructions or reimplantations. The advantages of this procedure described as early as 1960s by Fortner were also confirmed by our team in a subsequent report. We showed that TVE with in situ hypothermic perfusion is superior to TVE alone if used for more than 60 min in complex resections with or without vascular reconstruction. Other techniques (ex situ liver resection developed by Pichlmayr and ante situm liver resection by Hannoun) have been described; however, they have not been widely accepted due to a high rate of complications. In this article, we report our operative technique as well as discuss some important operative points. PMID:21540593

Hoti, Emir; Salloum, Chady; Azoulay, Daniel

2011-01-01

89

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.

90

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

Science.gov (United States)

This work is part of the inter-laboratory collaboration to study the stability of seven distinct sets of state-of-the-art organic photovoltaic (OPV) devices prepared by leading research laboratories. All devices have been shipped to and degraded at RISØ-DTU up to 1830 hours in accordance with established ISOS-3 protocols under defined illumination conditions. In this work, we apply the Incident Photon-to-Electron Conversion Efficiency (IPCE) and the in situ IPCE techniques to determine the relation between solar cell performance and solar cell stability. Different ageing conditions were considered: accelerated full sun simulation, low level indoor fluorescent lighting and dark storage. The devices were also monitored under conditions of ambient and inert (N(2)) atmospheres, which allows for the identification of the solar cell materials more susceptible to degradation by ambient air (oxygen and moisture). The different OPVs configurations permitted the study of the intrinsic stability of the devices depending on: two different ITO-replacement alternatives, two different hole extraction layers (PEDOT:PSS and MoO(3)), and two different P3HT-based polymers. The response of un-encapsulated devices to ambient atmosphere offered insight into the importance of moisture in solar cell performance. Our results demonstrate that the IPCE and the in situ IPCE techniques are valuable analytical methods to understand device degradation and solar cell lifetime. PMID:22828664

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

2012-09-01

91

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

DEFF Research Database (Denmark)

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

Teran-Escobar, Gerardo; Tanenbaum, David

2012-01-01

92

A Numerical Matching Technique for Resistive MHD Stability Analysis  

International Nuclear Information System (INIS)

Full text: We have developed a new numerical matching technique for linear stability analysis of resistive magnetohydrodynamics (MHD) modes. The conventional asymptotic matching theory has several difficulties in the numerical implementation in practice because of the singularity of the problem; i.e., (i) it is not applicable to the case where the minimum safety factor being a rational number in reversed-magnetic-shear tokamak plasmas since the rational surface becomes irregular singularity, and (ii) the numerical implementation is not so straightforward because of the sensitive behavior on the local equilibrium accuracy and grid arrangements near the rational surface. Unlike the conventional asymptotic matching theory, our numerical matching technique utilizes an inner layer with a finite width, which resolves those practical difficulties in the asymptotic matching theory. Neither the radial coordinate nor the growth rate is expanded by using smallness of the electrical resistivity in the inner layer. The inner-layer solution is directly, not asymptotically, matched onto the outer-region solution. We found that this direct matching is accomplished by requiring the continuity of perturbed magnetic field and the smooth disappearance of the parallel electric field. Our matching method is successfully applied to single and double tearing, internal kink and interchange modes. (author)

93

Stabilized amorphous glibenclamide nanoparticles by high-gravity technique  

International Nuclear Information System (INIS)

Highlights: · Amorphous glibenclamide nanoparticles of 220 nm are obtained using the high-gravity technique. · The dissolution rate of these nanoparticles achieves 85% in 5 min, while those of the raw glibenclamide and the commercial glibenclamide tablet only reach 35% and 55% respectively during the same period. · The morphology, particle size, crystalline form and dissolution rate of these nanoparticles almost remain constant after keeping more than 70 days. - Abstract: The stable amorphous glibenclamide nanoparticles was obtained via anti-solvent precipitation using the high-gravity technique in this study. The effects of operating variables on the particle size were investigated. The properties of glibenclamide nanoparticles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC) and dissolution test. The prepared glibenclamide nanoparticles had a mean size of 220 nm within a narrow distribution. The dissolution rate of glibenclamide nanoparticles was obviously faster than that of the raw glibenclamide or the commercial glibenclamide tablet. It achieved 85% in 5 min, while those of the raw glibenclamide and the commercial glibenclamide tablet achieved 35% and 55% respectively during the same period. The physical stability of the nanoparticles was tested after storing for more than 70 days at room conditions. Their morphology, particle size, crystalline form and dissolution rate almost remained constant during storage.

94

Stabilized amorphous glibenclamide nanoparticles by high-gravity technique  

Energy Technology Data Exchange (ETDEWEB)

Highlights: {center_dot} Amorphous glibenclamide nanoparticles of 220 nm are obtained using the high-gravity technique. {center_dot} The dissolution rate of these nanoparticles achieves 85% in 5 min, while those of the raw glibenclamide and the commercial glibenclamide tablet only reach 35% and 55% respectively during the same period. {center_dot} The morphology, particle size, crystalline form and dissolution rate of these nanoparticles almost remain constant after keeping more than 70 days. - Abstract: The stable amorphous glibenclamide nanoparticles was obtained via anti-solvent precipitation using the high-gravity technique in this study. The effects of operating variables on the particle size were investigated. The properties of glibenclamide nanoparticles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC) and dissolution test. The prepared glibenclamide nanoparticles had a mean size of 220 nm within a narrow distribution. The dissolution rate of glibenclamide nanoparticles was obviously faster than that of the raw glibenclamide or the commercial glibenclamide tablet. It achieved 85% in 5 min, while those of the raw glibenclamide and the commercial glibenclamide tablet achieved 35% and 55% respectively during the same period. The physical stability of the nanoparticles was tested after storing for more than 70 days at room conditions. Their morphology, particle size, crystalline form and dissolution rate almost remained constant during storage.

Yu Lei; Li Caixia [Key Lab for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Le Yuan, E-mail: leyuan@mail.buct.edu.cn [Key Lab for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Chen Jianfeng [Research Center of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, Beijing 100029 (China); Zou Haikui, E-mail: zouhk@mail.buct.edu.cn [Research Center of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, Beijing 100029 (China)

2011-10-17

95

FISH glossary: an overview of the fluorescence in situ hybridization technique.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The introduction of FISH (fluorescence in situ hybridization) marked the beginning of a new era for the study of chromosome structure and function. As a combined molecular and cytological approach, the major advantage of this visually appealing technique resides in its unique ability to provide an intermediate degree of resolution between DNA analysis and chromosomal investigations while retaining information at the single-cell level. Used to support large-scale mapping and sequencing efforts...

Volpi, Ev; Bridger, Jm

2008-01-01

96

Model predictions of metal speciation in freshwaters compared to measurements by in situ techniques.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Measurements of trace metal species in situ in a softwater river, a hardwater lake, and a hardwater stream were compared to the equilibrium distribution of species calculated using two models, WHAM 6, incorporating humic ion binding model VI and visual MINTEQ incorporating NICA-Donnan. Diffusive gradients in thin films (DGT) and voltammetry at a gel integrated microelectrode (GIME) were used to estimate dynamic species that are both labile and mobile. The Donnan membrane technique (DMT) and h...

Unsworth, Emily R.; Warnken, Kent W.; Zhang, Hao; Davison, William; Black, Frank; Buffle, Jacques; Cao, Jun; Cleven, Rob; Galceran, Josep; Gunkel, Peggy; Kalis, Erwin; Kistler, David; Leeuwen, Herman P.; Martin, Michel; Noe?l, Ste?phane

2007-01-01

97

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.

98

Synthesis of superhydrophobic silica nanofibrous membranes with robust thermal stability and flexibility via in situ polymerization.  

Science.gov (United States)

Superhydrophobic silica nanofibrous membranes exhibiting robust thermal stability and flexibility were prepared by a facile combination of electrospun silica nanofibers and a novel in situ polymerized fluorinated polybenzoxazine (F-PBZ) functional layer that incorporated SiO(2) nanoparticles (SiO(2) NPs). By using F-PBZ/SiO(2) NP modification, the pristine hydrophilic silica nanofibrous membranes were endowed with superhydrophobicity with a water contact angle (WCA) of up to 161°. Surface morphological studies have revealed that the wettability of resultant membranes could be manipulated by tuning the surface composition as well as the hierarchical structures. Quantitative fractal dimension analysis using the N(2) adsorption method has confirmed the correlation between hierarchical roughness and WCA for the modified membranes. Furthermore, the as-prepared membranes exhibited high thermal stability (450 °C), good flexibility (0.0127 gf cm), and comparable tensile strength (2.58 MPa), suggesting their use as promising materials for a variety of potential applications in high-temperature filtration, self-cleaning coatings, catalyst carriers, etc., and also provided new insight into the design and development of functional nanofibrous membranes through F-PBZ modification. PMID:22975924

Yang, Liping; Raza, Aikifa; Si, Yang; Mao, Xue; Shang, Yanwei; Ding, Bin; Yu, Jianyong; Al-Deyab, Salem S

2012-10-21

99

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2012-10-15

100

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Teran-escobar, Gerardo; Krebs, Frederik C.; Lira-cantu?, Monica

2012-01-01

 
 
 
 
101

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

102

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:...

103

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...

104

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)

105

In situ observation of the ovaries of llamas and alpacas by use of a laparoscopic technique.  

Science.gov (United States)

A laparoscopic technique was used to observe in situ the ovaries of llamas and alpacas. Use of this technique results in minimal surgical stress and allows repetitive observation of various reproductive stages in the same animal. Ovarian follicular activity before and after breeding, time of ovulation, corpus luteum formation and regression, early embryo death, failure of ovulation, and the early events of pregnancy can be assessed quickly and safely. For 1,291 laparoscopies performed, postsurgical disturbance was not observed, and animals were released from the clinic 1 hour after laparoscopy. PMID:1836452

Sumar, J; Bravo, P W

1991-11-01

106

A new pyrolysis technique using a diamond anvil cell: in situ visualization of kerogen transformation  

Energy Technology Data Exchange (ETDEWEB)

A pyrolysis technique has been developed to study hydrocarbon source rock potential by in situ visualization of kerogen transformation in a diamond anvil cell under a microscope (white and UV-light) using a CCD video monitoring system. The technique unables one to observe directly the processes and timing (or temperature) of kerogen transformation during pyrolysis in open or closed systems (either anhydrous or hydrous). It has been used to study a Green River kerogen and a lignite sample at heating rates similar to Rock-Eval pyrolysis under several pyrolysis conditions.

Huang, W.L. [Exxon Production Research Company, Houston, TX (United States)

1996-01-01

107

Lab scale testing of novel natural analog in situ stabilization agents  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1997-12-31

108

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

109

Stabilized in situ rectangular MgB2 wires: the effect of B purity and sheath materials  

International Nuclear Information System (INIS)

Stabilized four-filament SiC-added in situ MgB2 wires were prepared by the rectangular wire-in-tube (RWIT) technique, using boron powders of different purity (90% and 99%), SiC powders of different agglomerate size and sheaths of different metals. The critical current density at 11 T and 4.2 K improved by 5-10 times by using boron powder of higher purity, SiC powder of small agglomerate size, a chemically inert Ti barrier and mechanical support provided by a Monel sheath. The decrease in critical temperature (Tc) and increase in critical current density (Jc) of wires could be explained in terms of carbon doping. Formation of Mg2Si and B-rich secondary phases, and carbon substitution was studied using EDX chemical mapping in a scanning electron microscope (SEM). The addition of SiC results in the formation of B-rich secondary phases. Our results support the mechanism of carbon doping through the reaction of SiC with Mg to form Mg2Si and release free carbon. However, the extent of effective carbon doping depends on the size of the precursor SiC agglomerates, as large SiC agglomerates are unable to react with Mg. B precursor powder of lower purity and Mg2Si secondary phase formation led to incomplete phase formation of MgB2 and consequently to lowered Jc

110

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

Directory of Open Access Journals (Sweden)

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

M. Q. Liu

2015-01-01

111

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. PMID:25351344

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

2014-01-01

112

Prediction of etching results and etching stabilization by applying principal component regression to emission spectra during in-situ cleaning  

Energy Technology Data Exchange (ETDEWEB)

A method to predict etching results by analyzing plasma emission spectra during in-situ cleaning was investigated, where the plasma emission spectra indicate the surface condition of etching reactor walls. Plasma-wall interaction was evaluated by using both principal component regression of plasma emission spectra and attenuated-total-reflection Fourier-transform infrared spectroscopy. We found that differences in the amount of silicon oxide deposition on the reactor wall affected radical composition in the plasma during in-situ cleaning and consequently affected the etching results. Etching result predictions using the plasma spectra corresponded very well to the etching result measurements, which are used to improve etching stability.

Iwakoshi, Takehisa [Hitachi, Ltd., Central Research Laboratory, 1-280, Higashi-Koigakubo, Kokubunji, Tokyo 185-8601 (Japan)], E-mail: takehisa.iwakoshi.dj@hitachi.com; Hirota, Kosa; Mori, Masahito; Tanaka, Jun' ichi; Itabashi, Naoshi [Hitachi, Ltd., Central Research Laboratory, 1-280, Higashi-Koigakubo, Kokubunji, Tokyo 185-8601 (Japan)

2008-04-01

113

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1997-12-31

114

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

115

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

Science.gov (United States)

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.

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

2010-06-01

116

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

117

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

Energy Technology Data Exchange (ETDEWEB)

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.

McBreen, J.; Mukerjee, S.; Yang, X. Q.; Sun, X., Ein-Eli, Y.

1998-11-01

118

An in situ gross alpha monitoring technique for delineating fugitive mill tailings  

International Nuclear Information System (INIS)

In situ gross alpha counting of soils is an effective technique for measuring uranium mill tailings contamination. In a field test, five minute gross alpha measurements were found to be capable of discerning tailings contamination at a level of 1.5 Bq (total alpha) per gramme of soil (41 pCi/g) in the presence of natural soil radioactivity. This corresponds to 0.28 Bq/g (7.6 pCi/g) for 226Ra in tailings (with an assumption of secular equilibrium less 12% of radon and progeny). The equipment is inexpensive, rugged, and truly portable. (author)

119

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.)

120

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

 
 
 
 
121

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2000-03-31

122

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

123

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

124

Sequential in-situ saphenous vein bypass. Early results and technique.  

Science.gov (United States)

This report summarizes early results with saphenous vein bypass (SVB) utilizing both sequential and in-situ techniques (SIS SVB) in eight limbs requiring limb salvage. SIS SVB was performed to a variety of vessel combinations using "Y" graft, continuous, or vein extension techniques achieving early patency in all limbs, despite pedal arch disease. Postoperatively, there was a significant increase in ankle/brachial Doppler indices (ABI) (P less than 0.001) at dorsal pedal (0.23-0.88) and at posterior tibial (0.32-0.91). Successful isolated popliteal grafting was confirmed by return of phasic Doppler wave forms. All but one limb healed with minimal tissue loss within 1 month of bypass. Preoperative high resolution angiography and clinical Doppler evaluation of saphenous vein anatomy are mandatory to determine candidacy for SIS SVB. PMID:3882037

Rhodes, G R; Buchbinder, D

1985-02-01

125

"Squid-capture" modified in situ stent-graft fenestration technique for aortic arch aneurysm repair.  

Science.gov (United States)

An 83-year-old female was found to have an fusiform aneurysm in the aortic arch. She was deemed to be a high surgical risk; therefore, endovascular stent-graft placement followed by revascularization of the brachiocephalic trunk using in situ stent-graft fenestration was considered. However, the safe application of fenestration was deemed difficult due to the tortuosity of the brachiocephalic artery. The patient was successfully treated with the aid of the "squid-capture" technique, which consists of deployment of the stent-graft in a snare wire loop that was advanced from the brachiocephalic artery and fenestration of the stent-graft with the support of the loop. A follow-up exam revealed complete sealing of the aneurysm without any complications. The squid-capture technique allows for the safe and secure puncture of the graft. PMID:24943916

Hongo, Norio; Miyamoto, Shinji; Shuto, Rieko; Wada, Tomoyuki; Kamei, Noritaka; Sato, Aiko; Matsumoto, Shunro; Kiyosue, Hiro; Mori, Hiromu

2014-08-01

126

Membrane-attached biofilms for VOC wastewater treatment I: Novel in situ biofilm thickness measurement technique.  

Science.gov (United States)

This article reports a novel nondisruptive technique for measuring the thicknesses of membrane-attached biofilms in situ, using a single tube extractive membrane bioreactor (STEMB). The biodegradation of a toxic volatile organic compound (VOC) (1,2-dichloroethane [DCE]) by Xanthobacter autotrophicus GJ10 has been used as a model system to develop the technique. The results give information on the biomass-silicone rubber attachment phenomena, and on the development over time of biofilms growing on the silicone membrane, without disrupting operation. Experimental results are presented showing the evolution over time of biofilm thickness, and also the density of biofilms for four experimental runs. The hydrodynamic conditions on the biomedium side of the membrane were found to influence the initial attachment phenomena and subsequent biofilm growth. (c) 1995 John Wiley & Sons, Inc. PMID:18623369

Dos Santos, L M; Livingston, A G

1995-07-01

127

Synthèse bibliographique sur la mobilité des éléments traces dans les sols et l'utilisation de la stabilisation physico-chimique comme technique de gestion in situ des sites contaminés  

Directory of Open Access Journals (Sweden)

Full Text Available Review of the mobility of trace elements in soils and of the use of physico-chemical stabilization as an in situ management strategy for contaminated sites. Industrial activities have greatly impacted the quality of the biophysical environment in some areas. This review focuses on the consequences of soil contamination by metallic trace elements: what factors determine the mobility of contaminants in soils and what remediation practices based upon physico-chemical stabilization can be used in response? Physico-chemical stabilization is an in situ remediation technique, which aims at limiting the dispersion of metals in the environment through the use of soil conditioners and amendments in contaminated sites. In this article, we firstly review the concepts involved in the mobility of trace elements and their indicators. We then provide an overview of the current information regarding the different kinds of amendments that may be applied to stabilize contaminants in soils and the processes involved.

Liénard, A.

2014-01-01

128

Simple fiber-optic technique for in-situ corrosion sensing in structures  

Science.gov (United States)

Corrosion of structures is a serious problem involving man and material safety. Over the years, though several methods of monitoring corrosion have been devised with some success, but there is a persistent need for devising non-destructive and in-situ techniques for monitoring corrosion in structures. Fiber optic techniques are capable of meeting these requirements, besides offering several other important advantages. Fiber optic corrosion sensors have thus become quite attractive and are currently being investigated to address the high costs associated with the existing structural maintenance procedures. Fiber optics based direct absorption spectroscopic techniques investigated by some groups for estimating corrosion have used single fiber elements for recording the signal reflected from specimen at different wavelengths. As the light coupling efficiency of the single fiber elements is relatively poor in comparison with that of fiber bundles and the signal available for processing is weak, the paper presents a simple and alternate technique based on the color matching principle of fiber optic colorimetry to detect corrosion induced color changes. It employs a thin Y- shaped fiber optic bundle which increases the quantity of light energy coupled from a whitelight source. The light reflected off the sample is made incident on a PIN photo- detector through a complementary filter. A series of such probes can be safety embedded and or bonded to structures at pre-determined locations. The experimental set up for this sensor was implemented and feasibility of in-situ corrosion detection in structures demonstrated. Measurement data was acquired for steel samples corroded both in concrete embedded and open ambience conditions and results analyzed.

Singh, Nahar; Jain, Subhash C.; Aggarwal, Anil K.; Singla, Madan L.; Singh, Mewa

2000-05-01

129

Morphological stabilization by in situ polymerization of fullerene derivatives leading to efficient, thermally stable organic photovoltaics  

Energy Technology Data Exchange (ETDEWEB)

The successful design and synthesis of two styryl-functionalized fullerene derivatives, [6,6]-phenyl-C{sub 61}-butyric acid styryl dendron ester (PCBSD) and [6,6]-phenyl-C{sub 61}-butyric acid styryl ester (PCBS) is presented. The polymerizable PCBS or PCBSD materials are incorporated into a poly(3-hexylthiophene) (P3HT):[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) blend to form an active layer of ternary blend. The blending systems are first thermally annealed at 110 C for 10 min to induce optimal morphology, followed by heating at 150 C for 10 min to trigger the in situ polymerization of styrene groups. Through chemical crosslinking of PCBSD, the initial morphology of the blend (P3HT:PCBM:PCBSD = 6:5:1 in weight) can be effectively fixed and stably preserved. The device based on this blend shows extremely stable device characteristics, delivering an average power conversion efficiency (PCE) of 3.7% during long-term thermal treatment. By molecular engineering to reduce the insulating portion, PCBS with higher C{sub 60} content (71 wt%) possesses better electron-transport properties than PCBSD (58 wt%). Encouragingly, at a low doping concentration of PCBS in the blend (P3HT:PCBM:PCBS = 6:5:1 in weight), linear-polymerized PCBS can stabilize the morphology against thermal heating. This device exhibits more balanced charge mobility to achieve an average PCE of 3.8% over 25 h heating at 150 C. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Cheng, Yen-Ju; Hsieh, Chao-Hsiang; Li, Pei-Jung; Hsu, Chain-Shu [Department of Applied Chemistry, National Chiao Tung University, 1001 Ta Hsueh Road Hsin-Chu, 30010 (China)

2011-05-10

130

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

131

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

132

Using the in situ lift-out technique to prepare TEM specimens on a single-beam FIB instrument  

International Nuclear Information System (INIS)

Transmission electron microscope (TEM) specimens are today routinely prepared using focussed ion beam (FIB) instruments. Specifically, the lift-out method has become an increasingly popular technique and involves removing thin cross-sections from site-specific locations and transferring them to a TEM grid. This lift-out process can either be performed ex situ or in situ. The latter is mainly carried out on combined dual-beam FIB and scanning electron microscope (SEM) systems whereas conventional single-beam instruments often are limited to the traditional ex situ method. It is nevertheless desirable to enhance the capabilities of existing single-beam instruments to allow for in situ lift-out preparation to be performed since this technique offers a number of advantages over the older ex situ method. A single-beam FIB instrument was therefore modified to incorporate an in situ micromanipulator fitted with a tungsten needle, which can be attached to a cut-out FIB section using ion beam induced platinum deposition. This article addresses the issues of using an ion beam to monitor the in situ manipulation process as well as approaches that can be used to create stronger platinum welds between two objects, and finally, views on how to limit the extent of ion beam damage to the specimen surface.

133

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

Directory of Open Access Journals (Sweden)

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

Jeevanandham Arumugam

2009-01-01

134

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

135

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

DEFF Research Database (Denmark)

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

Kaiser, Andreas; Foghmoes, SØren Preben Vagn

2013-01-01

136

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

137

In situ superconducting MgB2 films grown by co-evaporation technique  

International Nuclear Information System (INIS)

Superconducting thin films of MgB2 were grown in situ by co-evaporation of magnesium and boron on MgO (111), SiC (0001) and Al2O3 (0001) substrates at ?300 C. The films showed transitions to the superconducting state in the temperature range of 33-37 K. The widths of the superconducting transitions were less than 1 K. The films exhibited growth in the c-axis and absence of other phases. Optimization of the growth parameters enabled films with smooth surface morphology and root-mean-square (RMS) roughness of 2 nm to be grown. The low RMS roughness value indicates that the technique can be used to grow MgB2 films useful for junctions and multilayer devices. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

138

The ID-KArD technique: In-situ dating on Mars  

Science.gov (United States)

The ability to measure absolute ages on the Martian surface is crucial for understanding the planet's evolution. A detailed geological history of the Moon has been determined through analysis of returned samples from specific units, and relative ages calculated by crater counting techniques. However, without returned samples or in-situ dating analyses, we lack absolute age markers for Mars and thus cannot accurately or precisely date its well-documented surface. Instead, we have relied on an estimated Mars/Moon cratering ratio and relative crater counting techniques in an attempt to calculate surface ages and classify geological units. The use of such relative parameters diminishes the precision and accuracy for surface age calculations, and thus highlights the need for independent age determinations from returned samples or in-situ dating. In this research, we describe our technique - ID-KArD (Isotope Dilution K-Ar Dating) - intended for in-situ age dating of geological units on the Martian surface. ID-KArD resolves two challenges that have previously obstructed in-situ age dating on Mars: 1) High fusion temperatures are avoided with the use of a lithium-borate flux; 2) Sample mass measurement is not required, due to the addition of an isotope dilution doubly-spiked glass. The glass has a known 39Ar/41K ratio, which removes the need for concentration measurements. Thus, only isotope ratios are required for a K-Ar age determination. ID-KArD has the potential to address Mars chronology inaccuracies, and would be a suitable technique for consideration on future missions. In the first phase of ID-KArD proof of concept, we selected a Viluy trap basalt (K2O ~ 0.7 wt%), with concordant K-Ar and Ar-Ar ages of 354.3 × 3.5 and 357.7 × 1.4 Ma respectively (Courtillot et al., 2010). An aliquot was combined into a crucible with the flux and the spike glass for separate Ar (MAP 215:50, Caltech), followed by K (KEMS, GRC) isotopic analysis. Combining our results, we obtained an age of 351 × 19 Ma (Farley et al., 2013), in good agreement with the previously published ages. For the second phase, we have designed and built a single instrument, capable of analysing both Ar and K from a single sample. The instrument includes two ionisation sources for separate K (thermal) and Ar (electron impact) ionsiation, and a quadrupole mass spectrometer. In addition, we have designed a sample heating mechanism that allows degassing of flux prior to sample addition, and achieves temperatures in the range of the SAM oven on Curiosity. Thus far, the instrument has successfully measured both isotopic systems, and following further testing in the coming weeks, we will date Martian surface analogues, age standards, and finally meteoritic material.

Cartwright, J. A.; Farley, K. A.; Hurowitz, J.; Asimow, P. D.; Jacobson, N. S.

2013-12-01

139

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

International Nuclear Information System (INIS)

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

140

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.

 
 
 
 
141

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

Energy Technology Data Exchange (ETDEWEB)

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

Frick, C. M.; Farrell, R. E.; Germida, J. J. [Saskatchewan Univ., Dept. of Soil Science, Saskatoon, SK (Canada)

1999-12-29

142

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

143

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

Science.gov (United States)

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 full-scale 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). PMID:12188555

Pind, P F; Angelidaki, I; Ahring, B K

2002-01-01

144

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

Directory of Open Access Journals (Sweden)

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

C. Hak

2005-05-01

145

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

Directory of Open Access Journals (Sweden)

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

C. Hak

2005-01-01

146

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

147

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

Energy Technology Data Exchange (ETDEWEB)

Highlights: Black-Right-Pointing-Pointer Organo-bentonites were prepared at C16TMABr/CEC ratios up to 11. Black-Right-Pointing-Pointer Disorder configuration of C16TMA cations was observed at higher C16TMABr/CEC ratios. Black-Right-Pointing-Pointer The evolved gases during the calcinations of organoclays were analyzed by MS-TG. Black-Right-Pointing-Pointer In situ XRD technique detected clearly the phase disorder in the range 50-150 Degree-Sign C. Black-Right-Pointing-Pointer 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 Degree-Sign C. Above this temperature, both phases collapsed due to the decomposition of the surfactants as recorded by mass spectrometry thermal gravimetric analysis.

Kooli, Fethi, E-mail: fkooli@taibahu.edu.sa [Taibah University, Department of Chemistry, PO Box 30002, Al-Madinah Al-Munawwarah (Saudi Arabia)

2013-01-10

148

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)

149

Dimensional stability of a novel polyvinyl siloxane impression technique  

Scientific Electronic Library Online (English)

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

150

Dimensional stability of a novel polyvinyl siloxane impression technique  

Scientific Electronic Library Online (English)

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

151

In situ investigation of structure and stability of niobium carbonitrides in an austenitic heat-resistant steel  

International Nuclear Information System (INIS)

The structure and stability of Nb(C,N) precipitates were direct observed during reheating of an austenitic heat-resistant steel using in situ hybrid observations. The coarsened ?-Nb(C,N) and finer ?-Nb(C,N) were present in as-received steel. During the coarsening process, the d-spacing of cubic ?-Nb(C,N) exhibits a sharp decrease with increasing temperature, while that of hexagonal ?-Nb(C,N) maintains a steady increase. Compared to ?-Nb(C,N), the ?-Nb(C,N) was quickly dissolved into the austenite during heating, and it would no longer reprecipitate in the subsequent cooling.

152

Fermentation Characteristics, In Situ Rumen Degradation and Aerobic Stability of Whole Crop Barley Ensiled with Urea or Aqueous Ammonia  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Various chemical compounds might be added to forage to maintain or improve the quality value of a crop ensiled. The aim of the present experiment was to evaluate the fermentation characteristics, in situ rumen degradation and Aerobic Stability of whole crop barley ensiled with Urea or aqueous Ammonia. In the first experiment, Whole crop barley was harvested (35% DM), chopped, and then ensiled using laboratory silos (n= 4) as untreated (UT) or treated with urea (10, 20, 30 and 40 g kg-1 DM;...

Vatandoost, Moosa; Mesgaran, Mohsen Danesh; Vakili, Alireza

2011-01-01

153

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

154

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1997-12-31

155

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

Science.gov (United States)

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

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

2014-05-01

156

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

157

Application of Arma Technique For Operation Stability of RSG-Gas  

International Nuclear Information System (INIS)

Application Of Arma Technique For Operation Stability Of RSG-Gas. Application of Fast Fourier Transport (FFT) method in the noise experiments data had been conducted to reactor kinetic parameter determination of RSG-Gas. Reactor stability that has closed relation to operation safety has not been measured yet. Noise analysis method and ARMA (Auto Regressive Moving Average) technique that has capability to identify mathematical model of the noise experimental data can be used for determination of kinetic/dynamic characteristic equation and its roots. From the roots of reactor characteristic equation, magnitude of natural frequency (fn), damping ratio (xi), damping frequency (fd), decay ratio (delta) and then reactor stability can be calculated

158

Immobilization, stabilization and patterning techniques for enzyme based sensor systems.  

Energy Technology Data Exchange (ETDEWEB)

Sandia National Laboratories has recently opened the Chemical and Radiation Detection Laboratory (CRDL) in Livermore CA to address the detection needs of a variety of government agencies (e.g., Department of Energy, Environmental Protection Agency, Department of Agriculture) as well as provide a fertile environment for the cooperative development of new industrial technologies. This laboratory consolidates a variety of existing chemical and radiation detection efforts and enables Sandia to expand into the novel area of biochemically based sensors. One aspect of this biosensor effort is further development and optimization of enzyme modified field effect transistors (EnFETs). Recent work has focused upon covalent attachment of enzymes to silicon dioxide and silicon nitride surfaces for EnFET fabrication. They are also investigating methods to pattern immobilized proteins; a critical component for development of array-based sensor systems. Novel enzyme stabilization procedures are key to patterning immobilized enzyme layers while maintaining enzyme activity. Results related to maximized enzyme loading, optimized enzyme activity and fluorescent imaging of patterned surfaces will be presented.

Flounders, A.W.; Carichner, S.C.; Singh, A.K.; Volponi, J.V.; Schoeniger, J.S.; Wally, K.

1997-01-01

159

Review of Motion Estimation and Video Stabilization techniques For hand held mobile video  

Directory of Open Access Journals (Sweden)

Full Text Available Video stabilization is a video processing technique to enhance the quality of input video by removing the undesired camera motions. There are various approaches used for stabilizing the captured videos. Most of the existing methods are either very complex or does not perform well for slow and smooth motion ofhand held mobile videos. Hence it is desired to synthesis a new stabilized video sequence, by removingthe undesired motion between the successive frames of the hand held mobile video. Various 2D and 3D motion models used for the motion estimation and stabilization. The paper presents the review of the various motion models, motion estimation methods and the smoothening techniques. Paper also describes the direct pixel based and feature based methods of estimating the inter frame error. Some of the results of the differential motion estimation are also presented. Finally it closes with a open discussion of research problems in the area of motion estimation and stabilization.

Paresh Rawat

2011-06-01

160

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

International Nuclear Information System (INIS)

f-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

 
 
 
 
161

Practical risk assessment techniques for evaluating borehole stability  

Energy Technology Data Exchange (ETDEWEB)

Borehole instability in weak, fissile or reactive shales causes problems in drilling and completion of oil wells, particularly in tectonically disturbed areas. The optimal window of bottomhole pressure or mud density can be determined using better well planning tools. The best fluid properties for drilling vertical, horizontal and deviated wells that penetrate these rocks can also be determined with the use of better well planning tools. Several predictive models have been developed to assess the risks associated with borehole instability. These models range from simple linear elastic models to more complex non-linear models that need numerical solutions. In addition to choosing the best model for a given borehole instability risk analysis, the accuracy and applicability of the model-based predictions depends significantly on the criteria used to identify the onset of unacceptable levels of borehole instability risk. This paper described the use of many different types of predictive models that are available in the STABView borehole stability analysis software package. A variety of instability risk criteria were shown, including: shear yielding initiation at the borehole wall, average radius of the yielded zone, cross-sectional area of rock yielding, total volume of yielded rock that detaches from the borehole wall, total volume of yielded rock for a given stratigraphic unit, rubble fill percentage for horizontal wells, borehole breakout width or angle, borehole wall convergence or squeezing in plastic shales, and hole enlargement due to erosion. The paper also described some advanced methods for predicting yielded rock detachment using a numerical geomechanical software program called FLAC. Several field examples were presented along with a method to calibrate instability risk estimates based on offset well experiences. 20 figs.

McLellan, P.; Hawkes, C. [Advanced Geotechnology Inc., Calgary, AB (Canada)

2001-07-01

162

Spectral Techniques for Solving PDE Stability Model of Vortex Rope  

CERN Document Server

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

Bistrian, Diana Alina

2012-01-01

163

Degradability Characteristics of Treated and Untreated Barley Grain Using In situ Technique  

Directory of Open Access Journals (Sweden)

Full Text Available This study was carried out to determine of degradability characteristics of untreated barely grain (UBG and treated barley grain with autoclaving at 120°C, 5´ (TBG1 and 20' (TBG2, treated barley grain at 100°C, 5´ (TBG3 and 20' (TBG4, using in situ technique in Ghizel sheep?s. The sheep fed diet content 40% alfalfa: 60% concentrate containing 2.9 Mcal kg-1 DM and 14% CP. The incubation times were 0, 4, 8, 16, 24, 36 and 48 h and rumen degradation of cp and DM was measured. The equation of p = a+b (1-e-ct was used for fitting of dry matter and crude protein disappearance data. The dry matter disappearance of TBG1 and TBG2 at 24 and 48 h were lower than the other treatments (p<0.05. The crude protein disappearance of 24 and 48 h of UBG was more than the other treatment (p<0.05. Treating of barley grain of 120°C (5' and 20' can be decreased ruminal crude protein degradability of barley grain resulting high escaped crude protein into lower digestive tract.

Akbar Taghizadeh

2008-01-01

164

Model predictions of metal speciation in freshwaters compared to measurements by in situ techniques.  

Science.gov (United States)

Measurements of trace metal species in situ in a softwater river, a hardwater lake, and a hardwater stream were compared to the equilibrium distribution of species calculated using two models, WHAM 6, incorporating humic ion binding model VI and visual MINTEQ incorporating NICA-Donnan. Diffusive gradients in thin films (DGT) and voltammetry at a gel integrated microelectrode (GIME) were used to estimate dynamic species that are both labile and mobile. The Donnan membrane technique (DMT) and hollow fiber permeation liquid membrane (HFPLM) were used to measure free ion activities. Predictions of dominant metal species using the two models agreed reasonably well, even when colloidal oxide components were considered. Concentrations derived using GIME were generally lower than those from DGT, consistent with calculations of the lability criteria that take into account the smaller time window available forthe fluxto GIME. Model predictions of free ion activities generally did not agree with measurements, highlighting the need for further work and difficulties in obtaining appropriate input data. PMID:16570619

Unsworth, Emily R; Warnken, Kent W; Zhang, Hao; Davison, William; Black, Frank; Buffle, Jacques; Cao, Jun; Cleven, Rob; Galceran, Josep; Gunkel, Peggy; Kalis, Erwin; Kistler, David; Van Leeuwen, Herman P; Martin, Michel; Noël, Stéphane; Nur, Yusuf; Odzak, Niksa; Puy, Jaume; Van Riemsdijk, Willem; Sigg, Laura; Temminghoff, Erwin; Tercier-Waeber, Mary-Lou; Toepperwien, Stefanie; Town, Raewyn M; Weng, Liping; Xue, Hanbin

2006-03-15

165

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

166

In situ fabrication of spherical porous tin oxide via a spray pyrolysis technique  

International Nuclear Information System (INIS)

Spherical porous tin oxide was fabricated via a spray pyrolysis technique. TEM revealed that the primary SnO2 crystals had an average size of 5-10 nm. Good interconnection between SnO2 crystals is also observed. The electrochemical measurements showed that the spherical porous SnO2 samples have excellent cyclability, which can deliver a reversible capacity of 410 mAh/g for up to 50 cycles as a negative electrode for lithium batteries. Our approach for enhancing the structural stability of tin oxide is to incorporate spherical porous structures as a buffer zone to alleviate the volume expansion of the tin oxide anode during lithiation/delithiation

167

Automated quantitative analysis of in-situ NaI measured spectra in the marine environment using a wavelet-based smoothing technique  

Energy Technology Data Exchange (ETDEWEB)

An algorithm for automated analysis of in-situ NaI {gamma}-ray spectra in the marine environment is presented. A standard wavelet denoising technique is implemented for obtaining a smoothed spectrum, while the stability of the energy spectrum is achieved by taking advantage of the permanent presence of two energy lines in the marine environment. The automated analysis provides peak detection, net area calculation, energy autocalibration, radionuclide identification and activity calculation. The results of the algorithm performance, presented for two different cases, show that analysis of short-term spectra with poor statistical information is considerably improved and that incorporation of further advancements could allow the use of the algorithm in early-warning marine radioactivity systems. - Highlights: > Algorithm for automated analysis of in-situ NaI {gamma}-ray marine spectra. > Wavelet denoising technique provides smoothed spectra even at parts of the energy spectrum that exhibits strong statistical fluctuations. > Automated analysis provides peak detection, net area calculation, energy autocalibration, radionuclide identification and activity calculation. > Analysis of short-term spectra with poor statistical information is considerably improved.

Tsabaris, Christos, E-mail: tsabaris@ath.hcmr.gr [Hellenic Centre for Marine Research, Institute of Oceanography, P.O. Box 712, GR 19013 Anavyssos (Greece); Prospathopoulos, Aristides [Hellenic Centre for Marine Research, Institute of Oceanography, P.O. Box 712, GR 19013 Anavyssos (Greece)

2011-10-15

168

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2011-01-01

169

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2007-01-01

170

Technique for thermal stability determination of heat resisting coatings on graphite  

International Nuclear Information System (INIS)

It is shown possible to produce certain heat-resisting coatings on graphite by plasma spraying. A diagram of the device for a qualitative estimation of the coating for thermal stability using a plasmatron for spraying is given. The procedure developed may be recommended as a proximate method for estimating thermal stability of heat-resisting coatings applied to graphite and other structural materials according to the plasma spraying technique

171

Analysis of frequency offset in the frequency stabilization of semiconductor laser based on frequency dithering technique.  

Science.gov (United States)

We investigate the frequency offset in the frequency stabilization of a semiconductor laser based on a frequency-dithering technique. An analytical model is presented to describe the effects of the amplitude modulation and the phase delay between the amplitude and frequency modulation on the frequency stabilization. We also experimentally and analytically show that the frequency offset could be reduced by using an appropriate phase-sensitive detection. PMID:19550695

Park, Paul K; Chung, Y C

2007-10-17

172

Automated quantitative analysis of in-situ NaI measured spectra in the marine environment using a wavelet-based smoothing technique.  

Science.gov (United States)

An algorithm for automated analysis of in-situ NaI ?-ray spectra in the marine environment is presented. A standard wavelet denoising technique is implemented for obtaining a smoothed spectrum, while the stability of the energy spectrum is achieved by taking advantage of the permanent presence of two energy lines in the marine environment. The automated analysis provides peak detection, net area calculation, energy autocalibration, radionuclide identification and activity calculation. The results of the algorithm performance, presented for two different cases, show that analysis of short-term spectra with poor statistical information is considerably improved and that incorporation of further advancements could allow the use of the algorithm in early-warning marine radioactivity systems. PMID:21742510

Tsabaris, Christos; Prospathopoulos, Aristides

2011-10-01

173

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

174

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

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, Power System Stabilizer (PSS and Automatic Voltage Regulator (AVR are coordinated to improve the transient stability of generator in power system. Coordinated design problem of AVR and PSS is formulated as an optimization problem. Particle Swarm Optimization (PSO technique is an advanced robust search method by the swarming or cooperative behavior of biological populations mechanism. The performance of PSO has been certified in solution of highly non-linear objectives. Thus, PSO technique has been employed to optimize the parameters of PSS and AVR in order to reduce the power system oscillations during the load changing conditions in single-machine, infinite-bus power system. The results of nonlinear simulation suggest that, by coordinated design of AVR and PSS based on PSO technique power system oscillations are exceptionally damped. Correspondingly, it’s shown that power system stability is superiorly enhanced than the uncoordinated designed of the PSS and the AVR controllers.

M. Rostami

2011-05-01

175

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

176

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

Science.gov (United States)

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

Liu, C. C.

1976-01-01

177

Technique for in situ measurement of the natural radiation field and the associated exposure rate  

International Nuclear Information System (INIS)

A mobile environmental radiation laboratory was developed to measure the natural radiation field in situ and to deduce the resulting gamma-ray dose-exposure rate. The laboratory consisted of a truck, a Ge(Li) high-resolution gamma-ray spectrometer, associated electronics, and a calculator capable of analyzing the data completely at the measurement site. Preliminary in situ measurements indicated excellent agreement with laboratory soil analyses and environmental thermoluminescent dosimetry determinations

178

A novel in-situ technique to fabricate thin films with controlled lateral thickness modulations  

Science.gov (United States)

Surfaces having well-defined morphologies like periodic arrays of dots or lines, promise useful applications. Magnetic nanodots of Co and Fe-alloys are useful in patterned magnetic recording media. Well controlled grain size and surface area of nanostructured TiO2 are useful to develop efficient photocatalysts. However, there is a continuing need to develop techniques to make such surfaces in a simple and economical manner. In this thesis, a previously unexplored in-situ approach to assemble lateral patterns in thin films was proposed and investigated. Simple models of film growth on a defect free surface show that under uniform areal deposition rates and surface temperatures, nucleation occurs at random positions on the surface. We proposed that by exposing a growing thin film to a spatially varying surface temperature distribution, nucleation and growth can be confined to specific spatial locations. Consequently, a film with a desired pattern or thickness modulation could be achieved. The experimental approach consists of irradiating the substrate surface with a laser interference pattern simultaneous with physical vapor deposition (PVD). To perform such film growth experiments, a vibration minimized and multifunctional ultra-high vacuum chamber was integrated with a Nd:YAG laser. The laser output is a beam of 266 nm with a coherence length of approximately 2 m and an area of ˜0.8 x 0.8 cm2. The laser has a pulse width of 9 ns, a constant repetition rate of 50 Hz, with a rated peak output of 44 mJ/pulse. The typical laser energy density used in this work was about 10 mJ/cm2. Since sub-micron length scales were of interest, vibration studies were performed by recording the interference patterns on kapton films. Results from the kapton films, measurements using a shear accelerometer and recent growth results showed that peak-to-peak vibration amplitudes on the substrate surface were less than +/-25 nm. Well-established PVD techniques like pulsed laser deposition and electron beam evaporation were used to deposit Ag, Co or TiOx thin films on to single crystal Si(100) substrates. Typical deposition rates used in this work were 0.1 to 1 nm/min. Simultaneous deposition with irradiation of the Si surface with two-beam interference patterns resulted in films with periodic thickness modulations, producing line-like structures. (Abstract shortened by UMI.)

Zhang, Chi

179

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

180

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

 
 
 
 
181

Ecophysiological Analysis of Microorganisms in Complex Microbial Systems by Combination of Fluorescence In Situ Hybridization with Extracellular Staining Techniques  

Science.gov (United States)

Ecophysiological analysis and functions of single cells in complex microbial systems can be examined by simple combinations of Fluorescence in situ hybridization (FISH) for identification with various staining techniques targeting functional phenotypes. In this chapter, we describe methods and protocols optimized for the study of extracellular enzymes, surface hydrophobicity and specific surface structures. Although primarily applied to the study of microbes in wastewater treatment (activated sludge and biofilms), the methods may also be used with minor modifications in several other ecosystems.

Nielsen, Jeppe Lund; Kragelund, Caroline; Nielsen, Per Halkjær

182

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

183

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

Directory of Open Access Journals (Sweden)

Full Text Available 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, Bacterial Foraging Optimization Technique is applied for computing better optimized values.Results exhibit that BFO technique is able to find a better quality solution as compared to conventional technique for the proposed problem.

Poonam Singhal

2014-05-01

184

In situ studies of structural stability and proton conductivity of titanate nanotubes  

DEFF Research Database (Denmark)

Titanate nanotubes were prepared by hydrothermal treatment of anatase TiO2 with concentrated NaOH solution. In situ synchrotron X-ray diffraction studies revealed that the nanotubes are thermally unstable at temperatures above 360 degrees C and can transform directly to anatase via a dehydration and recrystallization process. This indicated that the titanate nanotubes possess an orthorhombic lepidocrocite (gamma-FeOOH)-type layered structure. An aggregate of the as-prepared nanotubes showed an electric conductivity of about 1 x 10(-6) S cm(-1) at 50 degrees C in humid atmospheres. The conductivity depended on humidity of the atmosphere and decreased with increasing temperatures, suggesting that the proton conduction in the titanate nanotubes might correlate with the interlayer H3O+ ions.

Gao, Tao; Fjeld, Harald

2009-01-01

185

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

Science.gov (United States)

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 H2O present. Observed radiation products included CO2 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 NH2sbnd CH2(R)sbnd COOH at 15 K to the zwitterion structure +NH3sbnd CH2(R)sbnd COO- at 140 K for each amino acid studied.

Gerakines, Perry A.; Hudson, Reggie L.; Moore, Marla H.; Bell, Jan-Luca

2012-08-01

186

In-Situ Measurements of the Radiation Stability of Amino Acids at 15-140 K  

Science.gov (United States)

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 D.8-MeV protons, and amino-acid decay was followed at each temperature with and without H2O present. Observed radiation products included CO2 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 NH2-CH2(R)-COOH at 15 K to the zwitterion structure +NH3-CH2(R)-COO- at 140 K for each amino acid studied.

Gerakines, Perry A.; Hudson, Reggie L.; Moore, Marla H.; Bell, Jan-Luca

2012-01-01

187

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.

Hansen, Thomas Willum; Wagner, Jakob Birkedal

2012-01-01

188

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 SciELO Colombia | Language: Spanish Abstract in spanish 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.

189

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

190

Estimation of Rumen Undegradable Protein with In Situ Nylon Bag and In Vitro Enzymatic Technique in Tropical Concentrate Feedstuffs  

Directory of Open Access Journals (Sweden)

Full Text Available Seventeen concentrate feedstuffs were used to study the relationships between the in vitro enzymatic technique and the in situ nylon bag technique for rumen undegradable protein determination. Feedstuffs were divided into 6 groups, 1 energy feed, 2 all protein feed, 3 feed higher than 15% crude protein (CP, 4 feed higher than 20% CP 5 feed lower than 20% CP and 6 all test feed. It was found that all test feed had the lowest relationship (R2 = 0.16, P < 0.1, n = 17. On the other hand, the group of higher than 15% CP feed had the highest relationship (R2 = 0.79, P < 0.0002, n = 9. The coefficient of determination (R2 of the energy feed, all protein feed, higher than 20% CP feed and lower than 20% CP feed were 0.66, 0.73, 0.74 and 0.58, respectively. This result suggested that the enzymatic technique can be used to predict the in situ nylon bag technique when the group of feed was separated by protein levels. Therefore, the enzymatic technique is an alternative technique for rumen undegradable protein determination in tropical concentrate feedstuffs, particularly those with high protein feed (>15%CP.

Songsak CHUMPAWADEE

2005-01-01

191

Degradabilidade ruminal de camas de frangos pela técnica dos sacos de náilon in situ com bovinos / Poultry litter ruminal degradability through in situ nylon bag technique with heifers  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Avaliou-se a degradabilidade ruminal da matéria seca (MS), matéria orgânica (MO) e proteína bruta (PB) de camas de frangos tendo como substrato cascas de arroz, cascas de amendoim e sabugo de milho, através da técnica de sacos de náilon in situ em bovinos dotados de fístulas permanentes de rúmen ali [...] mentados com silagem de milho e cama de frangos. O delineamento estatístico foi o de blocos ao acaso, com repetição dentro dos blocos, e os resultados obtidos foram: a degradabilidade efetiva da MS (calculada para taxa de passagem de 0,02) da cama de cascas de amendoim (70,07%) igualou a degradabilidade da cama de sabugo de milho (67,42%) e ambas superaram (p Abstract in english Ruminal dry matter (DM), organic matter (OM) and crude protein (CP) degradabilities of poultry litter containing either rice hulls, peanuts hulls or corn cobs were estimated through in situ nylon bag technique with rumen fistulated heifers fed with corn silage and poultry litter. Statistical design [...] was randomized blocks. The results showed that DM effective degradability of peanuts hulls poultry litter (70.07%) was similar to corn cobs (67.42%) and higher than (p

Laércio, MELOTTI; Carlos de Sousa, LUCCI; Sérgio Carlo Franco, MORGULLIS; Ari Luiz de, CASTRO; Paulo Henrique Mazza, RODRIGUES.

192

Estimation of Rumen Undegradable Protein with In Situ Nylon Bag and In Vitro Enzymatic Technique in Tropical Concentrate Feedstuffs  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Seventeen concentrate feedstuffs were used to study the relationships between the in vitro enzymatic technique and the in situ nylon bag technique for rumen undegradable protein determination. Feedstuffs were divided into 6 groups, 1) energy feed, 2) all protein feed, 3) feed higher than 15% crude protein (CP), 4) feed higher than 20% CP 5) feed lower than 20% CP and 6) all test feed. It was found that all test feed had the lowest relationship (R2 = 0.16, P < 0.1, n = 17). On the other hand, ...

Pattarajinda, Virote; Chumpawadee, Songsak; Vongpralub, Thevin; Sommart, Kritapon

2005-01-01

193

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

194

Techniques for Assessing the Performance of In Situ Bioreduction and Immobilization of Metals and Radionuclides in Contaminated Subsurface Environments  

Science.gov (United States)

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 presentation 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 presentation 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.

Watson, D. B.; Jardine, P. M.

2005-05-01

195

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

196

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

197

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

International Nuclear Information System (INIS)

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

198

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)

199

In situ transmission FTIR spectroelectrochemistry: A new technique for studying lithium batteries  

International Nuclear Information System (INIS)

In situ transmission FTIR spectra are measured during the electrochemical insertion of lithium into phospho-olivine FePO4. The spectroelectrochemical cell consists of a composite FePO4 cathode, a lithium metal anode, and an electrolyte of 1 M LiPF6 in a 1:1 mixture of ethylene carbonate and diethyl carbonate (EC-DEC). Bands belonging to the electrolyte and cathode are identified in the infrared spectra of the in situ cells. The antisymmetric PO4 3- bending vibrations (?4) are used to monitor Li+ insertion into FePO4. Discharging produces spectral changes that are consistent with the formation of phospho-olivine LiFePO4, yet the electrolyte bands are not affected by the discharging process. The in situ infrared experiments confirm the two-phase mechanism for lithium insertion into FePO4. Moreover, the experiments demonstrate the ability to collect in situ transmission FTIR spectra of functioning electrode materials in lithium batteries. Unfortunately, lithium plating occurs on the optical window when the Li//FePO4 half-cells are charged. The use of an intercalation anode such as graphite could alleviate this problem; however, this avenue of research is not explored in this study

200

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

 
 
 
 
201

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

202

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.

203

Determination of stability constants of Th(IV)-catechol complexes using pH titration technique  

International Nuclear Information System (INIS)

Protonation constants, pKa, of catechol and stability constant of thorium (IV) catechol complex were studied in 1M NaClO4 medium at 23±0.5 degC, using pH titration technique. The protonation and stability constant values for catechol were computed using a highly evolved software program HYPERQUAD. Catechol was found to form [Th(L)OH]+ complex (log ?11-1 = 14.06±0.10) in the pH range 1.5-4. (author)

204

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

CERN Document Server

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

Savulescu, Savu

2014-01-01

205

[Research on the application of in-situ biological stabilization solidification technology in chromium contaminated site management].  

Science.gov (United States)

In-situ biological stabilization solidification (SS) technology is an effective ground water risk control method for chromium contaminated sites. Through on-site engineering test, this paper has preliminarily validated the remediation effect of in-situ SS method on a southern chromium contaminated site. The engineering test site has an area of approximately 600 m2, and is located at the upstream of the contaminated area. Due to the severe contamination of chromium, the total chromium concentration reached up to 11,850 mg x kg(-1), while the hexavalent chromium concentration reached up to 349 mg x kg(-1), and the most severely contaminated soil had a depth of -0.5 - -2 m. Variations in hexavalent chromium and total chromium concentration in groundwater were observed through the injection of reducing agents and microbial regulators into the injection wells in the test site, and through the monitoring analysis at different time and different depth under the action of the injection agents. Results of the engineering test showed that the on-site SS technology significantly changed the chromium speciation in soil and then reduced the migration of chromium, thus the groundwater risk was reduced. The injected agents had a good effect of hexavalent chromium remediation in groundwater within the effective range of the injection wells, and the SS rate of hexavalent chromium into trivalent chromium reached 94%-99.9%, the SS rate of total chromium fixation reached 83.9%-99.8%. The test results are of significant reference value for the remediation of contaminated sites with features of shallow groundwater depth and soil mainly consisting of silty clay and sandy clay. PMID:24289024

Zhang, Jian-rong; Li, Juan; Xu, Wei

2013-09-01

206

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

207

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

208

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

209

Neutron capture gamma-ray technique for in situ mineral analysis  

International Nuclear Information System (INIS)

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

210

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

211

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

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

International Nuclear Information System (INIS)

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

214

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

International Nuclear Information System (INIS)

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

215

The Kapandji technique for fixation of distal radius fractures--a biomechanical comparison of primary stability.  

Science.gov (United States)

The goal of this study was to compare Kapandji-K-wiring and established K-wiring techniques of the distal radius fracture for primary stability in a biomechanical model: dorsal K-wiring according to Kapandji using different angles of the K-wire, parallel and diagonal alignment of the K-wires. A new testing system which uses a synthetic material enabled us to carry out the cantilever bending test. By application of a lower load, the Kapandji procedure shows a higher reactive torque and stiffness. A higher reaction force of the other techniques, especially of the parallel wiring, are only observable under high-grade bending stress. Application of the Kapandji procedure with K-wires at a smaller angle to the axis of the radius results in the highest primary stability of the procedures investigated in the essential range of initial deformation. PMID:11262777

Mittelmeier, W; Braun, C; Schäfer, R

2001-01-01

216

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)

217

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

Science.gov (United States)

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.

Krsti?, Jelena; Spasojevi?, Jelena; Radosavljevi?, Aleksandra; Šiljegov?, Milorad; Ka?arevi?-Popovi?, Zorica

2014-03-01

218

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

219

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

Directory of Open Access Journals (Sweden)

Full Text Available 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-Bus Reliability Test System (RTS was adopted for validation purposes, while comparative studies were performed with other techniques such as Artificial Immune System (AIS and Automatic Voltage Stability Analysis (AVSA to highlight the merit of EP.

Abdul Rahman Minhat

2008-01-01

220

NPP buildings and components seismic stability analysis in the frame of the standardized technique  

International Nuclear Information System (INIS)

Rough estimation of reliability of NPP component and equipment operation (probabilities of unfailing) during earthquakes according to the linear-spectral theory of seismic stability is suggested. The given technique allow to take into account, when estimating reliability of equipment and component operation, randomness of a great amount of factors determining structural strength, such as: parameters of seismic and other effects, deformation and strength properties of material and structures, different modes of equipment operation, conditionality of calculation diagram etc. The technique give possibility to detect resorces of load-carrying structures and to decrease specific consumption of structure materials providing the required level of their reliability

 
 
 
 
221

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

222

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)

223

An in-situ monitoring technique for optimizing antireflection coatings using a monolithic integrated photodetector  

DEFF Research Database (Denmark)

A very low reflectivity of the order of 10-4 is demonstrated for dual-layer anti-reflection coatings on normal facet semiconductor lasers, by integrated in situ monitoring. The method has been tested on three and eight quantum-well InGaAsP ridge lasers that consist of a gain section and an integrated absorber section. The principle is to monitor the change in the photocurrent generated in the absorber that is proportional to the output optical intensity from the laser, which changes as the coating progresses.

Yvind, Kresten; Larsson, David

2006-01-01

224

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

225

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

226

Fiber-optic fourier transform mid-infrared reflectance spectroscopy: a suitable technique for in situ studies of mural paintings.  

Science.gov (United States)

A prototypical in situ noninvasive study of ancient mural painting materials has been carried out using an easily manageable fiber-optic Fourier transform mid-infrared (mid-FT-IR) reflectance spectrophotometer. The reported object of the study is the Renaissance fresco by Pietro Vannucci, called il Perugino, located in the church of Santa Maria delle Lacrime (1521, Trevi, Perugia Italy). For the first classification and interpretation of infrared spectra, principal components analysis was used. Spectral artifacts due to lacunas, restoration materials, or alteration products have been identified, as well as two different secco refinements bound in a tempera medium. For the characterization of inorganic pigments, mid-FT-IR spectra have been integrated with other data obtained through in situ X-ray fluorescence (XRF) elemental analysis. This complementary noninvasive approach led to the characterization of Perugino's pigments, even in the presence of complex mixtures. The mid-FT-IR noninvasive technique, in combination with XRF, is thus recommended as a valuable first approach for the examination of mural paintings, permitting the assessment of the execution technique as well as contributing to the evaluation of the conservation state. PMID:17389069

Miliani, C; Rosi, F; Borgia, I; Benedetti, P; Brunetti, B G; Sgamellotti, A

2007-03-01

227

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

CERN Document Server

Length and g-factor are fundamental parameters that characterize optical cavities. We developed a technique to measure these parameters in-situ by determining the frequency spacing between the resonances of fundamental and spatial modes of an optical cavity. Two laser beams are injected into the cavity, and their relative frequency is scanned by a phase-lock loop, while the cavity is locked to either laser. The measurement of the amplitude of their beat note in transmission reveals the resonances of the longitudinal and the transverse modes of the cavity and their spacing. This method proves particularly useful to characterize complex optical systems, including very long and/or coupled optical cavities, as in gravitational wave interferometers. This technique and the results of its application to the coupled cavities of a 40-meter-long gravitational wave interferometer prototype are here presented.

Stochino, Alberto; Adhikari, Rana X

2012-01-01

228

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

International Nuclear Information System (INIS)

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

229

In situ non-invasive investigation on the painting techniques of early Meissen Stoneware  

Science.gov (United States)

In situ, non-invasive investigations by means of portable X-ray fluorescence and fibre optic reflectance mid-infrared (mid-FTIR) spectroscopy of painted Böttger Stoneware objects have been carried out through the MOLAB transnational access to the Porcelain Collection of the Staatliche Kunstsammlungen in Dresden. It has been possible to gather information regarding the composition of the black glaze by applying a principal component analysis to the elemental analysis to distinguish between the variations of lead, iron and manganese compositions of each glaze. It has been furthermore feasible to combine molecular spectroscopy for characterization of the constituent painting materials, namely lead white as cerusite and hydrocerusite, the use of cinnabar, azurite and Prussian blue leading to a better knowledge of the state of conservation and utility of certain pigments that may give rise to chronology of the decorative artwork. The identification of oxalates namely whedellite and moolooite are assigned as degradation products relative to the decorative areas.

Miliani, Costanza; Doherty, Brenda; Daveri, Alessia; Loesch, Anette; Ulbricht, Heike; Brunetti, Brunetto G.; Sgamellotti, Antonio

2009-08-01

230

Development of Technique for Testing the Long-Term Stability of Silicon Microstrip Detectors  

International Nuclear Information System (INIS)

An automatic multi-channel set-up prototype for simultaneous testing of the Long-Term Stability (LTS) of more than ten detectors is described. The Inner Tracking System of the ALICE experiment will include about two thousand Double-sided Microstrip Detectors (DSMD). Efficient automatic measurement techniques are crucial for the LTS test, because the corresponding test procedure should be performed on each detector and requires long time, at least two days. By using special adapters for supporting and connecting the bare DSMDs, failing detectors can be screened out before module assembly, thus minimizing the cost. Automated probe stations developed for a special purpose or for microelectronics industry are used for measuring physical static DSMD characteristics and check good-to-bad elements ratio for DSMD. However, automated (or semi-automatic)test benches for studying LTS or testing DSMD long-term stability before developing a detecting module are absent

231

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

Energy Technology Data Exchange (ETDEWEB)

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.

Arora, H.S.; Tamura, T.; Boegly, W.J.

1980-09-01

232

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

233

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

International Nuclear Information System (INIS)

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

234

A New in Situ Synchrotron X-ray Diffraction Technique to Study the Chemical Delithiation of LiFePO4  

Energy Technology Data Exchange (ETDEWEB)

We report a new synchrotron based in situ X-ray diffraction (XRD) technique to study the chemical delithiation of LiFePO{sub 4}. This technique provides a new powerful tool to study chemical reactions with excellent time-resolving power for dynamic studies.

Wang, X.Y.; Chen, H.-Y.; Yu, X.; Wu, L.; Nam, K.-W.; Bai, J.; Li, H.; Huang, X.; Yang, X.-Q.

2011-07-07

235

A New in Situ Synchrotron X-ray Diffraction Technique to Study the Chemical Delithiation of LiFePO4  

Energy Technology Data Exchange (ETDEWEB)

We report a new synchrotron based in situ X-ray diffraction (XRD) technique to study the chemical delithiation of LiFePO{sub 4}. This technique provides a new powerful tool to study chemical reactions with excellent time-resolving power for dynamic studies.

X Wang; H Chen; X Yu; L Wu; K Nam; J Bai; H Li; X Huang; X Yang

2011-12-31

236

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)

237

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

Science.gov (United States)

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

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

2012-10-01

238

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

Science.gov (United States)

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.

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

2012-07-01

239

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

240

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

C. Zellweger

2012-10-01

 
 
 
 
241

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

International Nuclear Information System (INIS)

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 deg. 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

242

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

243

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

244

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

International Nuclear Information System (INIS)

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

245

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

Science.gov (United States)

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

Chowdhury, Nabin; Nakhla, George; Zhu, Jesse

2012-01-01

246

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1997-06-01

247

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)

248

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

Science.gov (United States)

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.

Sabelström, N.; Hayashi, M.; Watanabe, T.; Nagata, K.

2014-10-01

249

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)

250

A gelatin in situ-overlay technique localizes brain matrix metalloproteinase activity in experimental focal cerebral ischemia.  

Science.gov (United States)

To determine the activity of matrix metalloproteinases (MMP), especially MMP-2 and MMP-9, which play an important role in ischemic stroke and intracerebral hemorrhage, we adapted a simple and rapid method for localizing gelatinase activity to a gelatin film in situ-overlay technique previously used in cancer research. Ten micrometer cryosections of rat brain from controls and animals subjected to 3 h of ischemia and 48 h of reperfusion (suture model for transient cerebral ischemia) were used. After thawing, a gelatin film with a polyester base was put on the slide, incubated for 24 h at 37 degrees C, stained with Ponceau S, and then discolored in bi-distilled water. Non-staining areas on the film corresponded to lysis zones, caused by activated MMPs. This was proven by MMP incubation at various concentrations on the plain gelatin film and pretreatment with EDTA (an MMP inhibitor), which prevents lysis zones in normal and ischemic brains. As confirmatory tests, SDS-PAGE zymography was used to define MMP activity, and also MMP-2 immunohistochemistry to detect the possibly cellular origin of MMPs. Normal rat brain exhibited a low background activity, which was visible as a light halo-like lysis zone over and around the brain. Areas in normal brain with medium MMP activity were within the white matter (corpus callosum, anterior commissure, and cerebellum). Ischemic brain exhibited high activity lysis zones within the infarcted area (detected by microtubuli associated protein-2 staining). These zones consisted of microscopically small lysis holes with a diameter of about 10-20 microm. Immunohistochemistry showed that especially microvessels expressed MMP antigen. SDS-PAGE zymography differentiated between a high level of activated MMPs in the ischemic area and a low level in the non-ischemic basal ganglia. The gelatin film in situ-overlay technique is able to localize MMP activity in ischemic rat brain tissue on a microscopic level. PMID:12044662

Loy, M; Burggraf, D; Martens, K H; Liebetrau, M; Wunderlich, N; Bültemeier, G; Nemori, R; Hamann, G F

2002-05-15

251

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

252

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

International Nuclear Information System (INIS)

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

253

High temperature X-ray diffraction: a in situ technique for phase transformation and formation analysis  

International Nuclear Information System (INIS)

High temperature X-ray diffraction technique was used in phases change analysis at zirconia doped with transition metals. The (HTXDR) patterns obtained show gradual transformation of monoclinic phase to tetragonal phase, at 900 to 1250 deg C. The technique was used in phases formation study of typical varistor composition with relation sb/Bi = 2. The patterns analysis of the composition Zn O Bi2 O3 Sb2 O3, show Bi3 Zn2 Sb3 O14 (formation. These reactions occurs at two different temperature regions. The high temperature X-ray diffraction was effective in the phases formation and phases transformation study, specially in relation to the sensitivity to phases detection. (author)

254

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2008-01-01

255

Sinus elevation by in situ utilization of bone scrapers: technique and results  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: English Abstract in english Objectives: The objective was to present a novel technique for antrostomy performed before sinus elevation in atrophic maxilla for subsequent implant placement. Material and methods: The study included 10 sinus elevations performed by the proposed technique in nine consecutive patients presenting wi [...] th inadequate posterior maxillary height. The technique is described, calculating the antrostomy surface area, volume of bone tissue obtained and final height attained in each case. A total of 16 implants were placed. Results: All ten elevations were accomplished. Mean antrostomy surface area was 0.55 mm², mean bone volume obtained was 0.56 cm³ and mean height attained was 11.7 mm from a baseline mean height of 5.6 mm. Out of the 16 implants, 14 were inserted immediately after the elevation and 2 were inserted in a second step, after ossification; 93.7% of the implants were osseointegrated at 6 months after prosthesis placement. Conclusion: The use of bone scrapers to create antrostomy for sinus elevation is a simple and very safe procedure. It provides a variable amount of particulate bone graft that is easily handled and highly useful for packing the cavity that will elevate the sinus membrane.

Pedro, Martos Díaz; Luis, Naval Gías; Jesús, Sastre Pérez; Raúl, González García; Fernando, Bances del Castillo; María, Mancha de la Plata; Pablo, Galindo Moreno; Mario, Muñoz Guerra.

2007-11-01

256

Sinus elevation by in situ utilization of bone scrapers: technique and results  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: English Abstract in english Objectives: The objective was to present a novel technique for antrostomy performed before sinus elevation in atrophic maxilla for subsequent implant placement. Material and methods: The study included 10 sinus elevations performed by the proposed technique in nine consecutive patients presenting wi [...] th inadequate posterior maxillary height. The technique is described, calculating the antrostomy surface area, volume of bone tissue obtained and final height attained in each case. A total of 16 implants were placed. Results: All ten elevations were accomplished. Mean antrostomy surface area was 0.55 mm², mean bone volume obtained was 0.56 cm³ and mean height attained was 11.7 mm from a baseline mean height of 5.6 mm. Out of the 16 implants, 14 were inserted immediately after the elevation and 2 were inserted in a second step, after ossification; 93.7% of the implants were osseointegrated at 6 months after prosthesis placement. Conclusion: The use of bone scrapers to create antrostomy for sinus elevation is a simple and very safe procedure. It provides a variable amount of particulate bone graft that is easily handled and highly useful for packing the cavity that will elevate the sinus membrane.

Pedro, Martos Díaz; Luis, Naval Gías; Jesús, Sastre Pérez; Raúl, González García; Fernando, Bances del Castillo; María, Mancha de la Plata; Pablo, Galindo Moreno; Mario, Muñoz Guerra.

257

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

International Nuclear Information System (INIS)

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

258

Ruminally undegradable protein content and digestibility for forages using the mobile bag in situ technique.  

Science.gov (United States)

Four experiments were conducted to evaluate RUP content and digestibility for smooth bromegrass, subirrigated meadow, upland native range, and warm-season grasses. Samples were collected from esophageally cannulated cows or ruminally cannulated steers. Forages were ruminally incubated in in situ bags for durations of time based on 75% of total mean retention time, which was based on IVDMD and rate of passage calculations. One-half of the bags were duodenally incubated and excreted in the feces, and NDIN was analyzed on all bags for RUP calculations. Crude protein was numerically greater early in the growing cycle for grasses compared with later as grasses matured (P ? 0.32). The RUP was 13.3%, 13.3%, and 19.7% of CP for smooth bromegrass, subirrigated meadow, and upland native range, respectively. These values tended to be lower early in the growth cycle and increased (linear P ? 0.13) as forages matured for warm-season grasses and subirrigated meadows. Because both CP and RUP content change throughout the growing season, expressing RUP as a percentage of DM gives more consistent averages compared with RUP as a percentage of CP. Coefficient of variation values for RUP as a percentage of DM averaged 0.21 over all 4 experiments compared with 0.26 for RUP as a percentage of CP. Average RUP as a percentage of DM was 2.03%, 1.53%, and 1.94% for smooth bromegrass, subirrigated meadow, and upland native range, respectively. Total tract indigestible protein (TTIDP) linearly increased with maturity for subirrigated meadow samples (P warm-season grass samples. Digestibility of RUP varied considerably, ranging from 25% to 60%. Subirrigated meadow, native range, and smooth bromegrass samples tended to have linear decreases (P ? 0.11) in RUP digestibility throughout the growing season. The amount of digested RUP was fairly consistent across experiments and averages for smooth bromegrass, subirrigated meadow, and upland native range were 0.92%, 0.64%, and 0.49% of DM, respectively. Warm-season grasses in Exp. 2 had greater RUP (4.31% of DM) and amount of RUP digested (2.26% of DM), possibly because of cattle selecting for leadplant that contains more CP than the grasses. Forages can vary in CP, RUP, TTIDP, and RUP digestibility depending on the forage type, year, and time within year, but RUP digestibility is likely less than what previous sources have reported. PMID:23478833

Buckner, C D; Klopfenstein, T J; Rolfe, K M; Griffin, W A; Lamothe, M J; Watson, A K; MacDonald, J C; Schacht, W H; Schroeder, P

2013-06-01

259

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

260

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

 
 
 
 
261

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)

262

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

263

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

1997-03-01

264

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

265

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

266

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

Science.gov (United States)

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

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

2013-12-01

267

Advanced Techniques for Assessment of Postural and Locomotor Ataxia, Spatial Orientation, and Gaze Stability  

Science.gov (United States)

In addition to adapting to microgravity, major neurovestibular problems of space flight include postflight difficulties with standing, walking, turning corners, and other activities that require stable upright posture and gaze stability. These difficulties inhibit astronauts' ability to stand or escape from their vehicle during emergencies. The long-ter7n goal of the NSBRI is the development of countermeasures to ameliorate the effects of long duration space flight. These countermeasures must be tested with valid and reliable tools. This project aims to develop quantitative, parametric approaches for assessing gaze stability and spatial orientation during normal gait and when gait is perturbed. Two of this year's most important findings concern head fixation distance and ideal trajectory analysis. During a normal cycle of walking the head moves up and down linearly. A simultaneous angular pitching motion of the head keeps it aligned toward an imaginary point in space at a distance of about one meter in front of a subject and along the line of march. This distance is called the head fixation distance. Head fixation distance provides the fundamental framework necessary for understanding the functional significance of the vestibular reflexes that couple head motion to eye motion. This framework facilitates the intelligent design of counter-measures for the effects of exposure to microgravity upon the vestibular ocular reflexes. Ideal trajectory analysis is a simple candidate countermeasure based upon quantifying body sway during repeated up and down stair stepping. It provides one number that estimates the body sway deviation from an ideal sinusoidal body sway trajectory normalized on the subject's height. This concept has been developed with NSBRI funding in less than one year. These findings are explained in more detail below. Compared to assessments of the vestibuo-ocular reflex, analysis of vestibular effects on locomotor function is relatively less well developed and quantified. We are improving this situation by applying methodologies such as nonlinear orbital stability to quantify responses and by using multivariate statistical approaches to link together the responses across separate tests. In this way we can exploit the information available and increase the ability to discriminate between normal and pathological responses. Measures of stability and orientation are compared to measures such as dynamic visual acuity and with balance function tests. The responses of normal human subjects and of patients having well documented pathophysiologies are being characterized. When these studies are completed, we should have a clearer idea about normal and abnormal patterns of eye, head, and body movements during locomotion and their stability in a wide range of environments. We plan eventually to use this information to validate the efficacy of candidate neurovestibular and neuromuscular rehabilitative techniques. Some representative studies made during this year are summarized.

Wall, Conrad., III

1999-01-01

268

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

International Nuclear Information System (INIS)

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

269

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

Energy Technology Data Exchange (ETDEWEB)

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).

Smith, Robert W.

2004-12-01

270

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

Energy Technology Data Exchange (ETDEWEB)

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

Smith, Robert W.

2005-06-01

271

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)

272

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

273

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

International Nuclear Information System (INIS)

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

274

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

275

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

International Nuclear Information System (INIS)

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

276

Numerical-perturbation technique for stability of flat-plate boundary layers with suction  

Science.gov (United States)

A numerical-perturbation scheme is proposed for determining the stability of flows over plates with suction through a finite number of porous suction strips. The basic flow is calculated as the sum of the Blasius flow and closed-form linearized triple-deck solutions of the flow due to the strips. A perturbation technique is used to determine the increment a(ij) in the complex wavenumber at a given location x(j) due to the presence of a strip centered at x(i). The end result is a set of influence coefficients that can be used to determine the growth rates and amplification factors for any suction levels without repeating the calculations. The numerical-perturbation results are verified by comparison with interacting boundary layers for the case of six strips and the experimental data of Reynolds and Saric for single- and multiple-strip configurations. The influence coefficient form of the solution suggests a scheme for optimizing the strip configuration. The results show that one should concentrate the suction near branch I of the neutral stability curve, a conclusion verified by the experiments.

Reed, H. L.; Nayfeh, A. H.

1986-01-01

277

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

278

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)

279

Bright Green Luminescence from Zirconium Oxide Stabilized with Tb3+ Ions Synthesized by Solution Combustion Technique  

Directory of Open Access Journals (Sweden)

Full Text Available In this research, the structural phase composition and room temperature luminescence properties of terbium doped zirconium oxide powders obtained by solution combustion synthesis method are presented as a function of the terbium content. The doping with terbium ions was performed during the redox combustion process and after annealing at 900°C during 20 hours. With the incorporation of the terbium ions into the zirconium oxide host, the stabilization of the high temperature tetragonal crystalline phase, as determined by x-ray diffraction technique, was obtained. Under ultraviolet radiation a bright green luminescence was observed at room temperature corresponding to the (4f electron configuration of the Tb3+ ion, namely the electronic transitions 5D4 ? 7Fn with n = 3 - 6. In addition, the undoped ZrO2 material showed green photoluminescence with high intensity.

S. López-Romero

2013-10-01

280

Photo stability of Uranine via Crossed-Beam Thermal Lens Technique  

International Nuclear Information System (INIS)

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

 
 
 
 
281

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

Directory of Open Access Journals (Sweden)

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

Brémand F.

2010-06-01

282

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

Science.gov (United States)

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

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

2010-06-01

283

In-situ verification of CANDU spent fuel by the Cherenkov technique  

International Nuclear Information System (INIS)

Multilayered and densely stacked irradiated CANDU fuel bundles in storage ponds make direct viewing of bundles in order to observe Cherenkov glow practically impossible. Ability to defect the source of Cherenkov glow by visual observation invariably suffers from subjective judgment. In the case of CANDU-type storage geometry, the difficulty in drawing conclusions is even greater for a number of reasons including the near neighbour effect. In this paper, the first results of Cherenkov photographic procedure without the isolation of individual trays are presented in which a new model of the Hungarian underwater telescope in combination with a lightmeter for Cherenkov intensity measurements has been used. It is demonstrated by this technique that photographs of bundles with cooling time of up to 2 a provide a satisfactory record for conclusive attribute verification result for irradiated fuel bundles stacked in multilayers. A distinct glow, with a brightness of higher intensity between the rod of a bundle compared to the surroundings of the bundle, is clearly shown by the pictures. Based on the results of the glow intensity measurements, the use of this photographic method for fuel bundles with longer cooling time of up to 15 a or more would require considerably longer exposure times or more sensitive film. Possible impact on IAEA safeguards of CANDU spent fuel bays by a system, which offers simultaneous item counting and NDA attribute test capabilities in a relatively low intrusive manner, is discussed. The limitations are also considered. (author)

284

A technique of placing cuffed endotracheal tubes through in situ paediatric laryngeal mask airways.  

Science.gov (United States)

If tracheal intubation is not possible using direct laryngoscopy, one option is to use a laryngeal mask airway (LMA) through which an endotracheal tube (ETT) can be passed. In children, however, the size of an uncuffed ETT that can pass through the lumen of an LMA is sometimes too small for the trachea, resulting in gas leakage around the ETT. Using a cuffed ETT may reduce the gas leak but withdrawal of the LMA is then prevented by the pilot balloon. In this study, the largest sizes of cuffed and uncuffed Mallinckrodt™ ETTs that could pass with ease through various sizes of paediatric Classic™ and ProSeal™ LMAs were documented. For cuffed ETTs, withdrawal of the LMA was made possible by simply cutting off the pilot balloon. The ETT cuff-inflating mechanism was then repaired by passing a 20 or 22 gauge cannula into the cut end of the inflating tubing. The proximal end of the cannula was then connected to a one-way valve or a three-way stopcock. This technique of cutting off the pilot balloon of the cuffed ETT made it possible to use paediatric cuffed ETTs in exchange for the LMAs tested. The task was easy to perform. Subsequent repair of the cuff-inflation tubing was effective and could withstand high pressures. These findings indicate that it is possible to pass cuffed ETTs through paediatric LMA lumens, which can provide ventilation without gas leaks, unlike uncuffed ETTs. PMID:24794472

Ho, A M H

2014-05-01

285

Stabilization of the sacroiliac joint with the SI-bone surgical technique.  

Science.gov (United States)

Although the motion of the sacroiliac joints (SIJ) is minimal, pain can originate from the SIJ on mechanical loading and affect walking, sitting and sleep patterns. The SIJ refers to the pair of joints inferior to the L5-S1 joint, and functions as the inferior adjacent level after a L5-S1 fusion. SIJ pain has a clinical overlay of symptoms often similar to low back pain (LBP) generated by the lumbar spine. The differential diagnosis in any patient with LBP should include the triad of low back, SIJ, and hip. SIJ pain is also a known cause of residual LBP after successful lumbar fusion. Relief of the patient's pain with a diagnostic SIJ block verifies the SIJ as the site of the pain generator. The SI-bone technique of stabilization of the SIJ is a true minimally invasive surgical technique performed through an initial small skin incision and then over pins, with the aid of fluoroscopy in three orthogonal axes with one axis parallel to the posterior sacral cortical line at the S1 to S2 region. The fluoroscopy procedure includes the following steps: 1) pre-op plan of the desired 3 implant trajectories to account for the anatomic variations; 2) placement of 3 Steinman pins at these trajectories across the SIJ starting in a small skin incision; 3) drill, broach and then implant placement as a cannulated system. All these steps are performed with the assistance of fluoroscopy in all three imaging planes - lateral, inlet and outlet views. The SI-Bone implants are triangular shaped titanium and have a rough surface for immediate stability. This rough surface is believed to aid in the osteo-fixation of the implants to the ilium and sacrum, as well as to long term fusion of the SIJ after its prolonged immobilization. The video can be found here: http://youtu.be/2YtFddohZRk. PMID:23829857

Geisler, Fred

2013-07-01

286

Influence of implant shape, surface morphology, surgical technique and bone quality on the primary stability of dental implants.  

Science.gov (United States)

The primary stability of dental implants has been investigated before, but a study of the influence of implant shape, size and surface morphology (machined, acid etched or anodized), surgical technique (press-fit or undersized) and substrate (natural or simulated bone) on the primary stability of dental implants has not been reported. The present work intends to fill this gap. In this work, six different dental implants were inserted into and removed from synthetic and natural bone while measuring the torque. A total of 255 dental implants with three shapes, four sizes and three surface topographies were inserted into pig rib, PTFE and polyurethane. The implant sites were prepared using straight and tapered drills. The primary stability was estimated from the maximum insertion torque. Comparisons between samples were based on the maximum insertion torque (MIT), the maximum removal torque (MRT) and the torque ratio (TR=MRT/MIT). The insertion torque into pig ribs showed larger dispersion. All parameters (shape, size and surface morphology of the implant, surgical technique and substrate type) were found to have a significant influence on primary stability. The insertion of a tapered implant requires a higher torque than the insertion of a straight implant. Surface treatments improve the primary stability. The influence of the surgical technique is smaller than that of implant size and shape. The highest insertion torque was that of anodized tapered implants inserted into undersized sites. Finally, the primary stability of dental implants is highly dependent on implant design, surgical technique and substrate type. PMID:23182386

Elias, Carlos Nelson; Rocha, Felipe Assis; Nascimento, Ana Lucia; Coelho, Paulo Guilherme

2012-12-01

287

The Impact of Chemical Abrasion on Trace Element Analysis of Zircon by In Situ Micro-Analytical Techniques  

Science.gov (United States)

Introduction of the chemical abrasion technique has significantly increased the precision and accuracy of ID-TIMS U-Pb dating of zircon. The chemical abrasion technique, coupled with thermal annealing, removes inclusions and metamict domains from zircon reducing the impact of Pb-loss leading to more concordant analyses.In this study, zircon from the Red Bluff Granitic Suite (TX) (ID-TIMS age 1120 ± 35 Ma) has been thermally annealed and chemically abraded prior to SHRIMP-RG and LA-MC-ICP-MS analysis.Chemically abraded zircon gives a date of 1109 ± 22 Ma with an average of 3% discordancy. This compares with dates of 1137 ± 48 Ma with an average of 39% discordancy for non-abraded zircon from the same sample. The dates overlap within uncertainty, but the age from chemically abraded zircon has a lower population uncertainty. Other petrographic and analytical observations of the chemically abraded zircon include brighter CL intensity, lower REE abundances, more consistent (smaller scatter) negative Eu/Eu* anomalies, less scatter in the chondrite-normalized LREE values, and a slightly less-steep chondrite normalized HREE slope. The data show that thermal annealing and chemical abrasion of zircon prior to analysis by in situ ion-beam or laser ablation techniques may result in better accuracy and greater concordance in U-Pb analysis of zircon. However, while improving the quality of some components of the trace element dataset (e.g. Eu anomalies) the process may prejudice the interpretation of zircon trace element data (e.g. HREECN slopes).

Romanoski, A.; Coint, N.; Cottle, J. M.; Hetherington, C. J.; Barnes, C. G.

2011-12-01

288

Formation studies and controlled production of carbon nanohorns using continuous in situ characterization techniques  

International Nuclear Information System (INIS)

The formation of carbon nanohorns by laser ablation was investigated using a scanning differential mobility analyzer combined with an ultrafine condensation particle counter. The measurement technique provided time-resolved size distributions for the carbon nanoparticles every minute during the course of the production run. The instrument performance was reasonably stable most of the time; however, during laser ablation, shockwave oscillations leading to significant transient flow and pressure variations were shown to disrupt the DMAs ability to measure accurate distributions. On the basis of the general trend observed in the data taken during the laser-ablation experiments, we found that the geometric mean diameter of the produced population shifted to larger particle sizes with increases in pulse width. For a given laser peak power and repetition rate, carbon nanoparticles of mobility diameter close to 100 nm were produced in a large abundance using longer laser pulse lengths (e.g., 10 ms) as compared to the shorter pulse lengths (e.g., 1 ms). A quantitative assessment of the particle size dispersion (using statistics like the geometric standard deviation) in relation to the laser pulse width could not be done with certainty as the shockwave disturbances produced by the laser-ablation process caused significant disruption to SMPS measurements. When laser ablation was not in operation, it was found that carbon nanoparticles with mobility diameters centred at about 20ith mobility diameters centred at about 20 nm could be produced by thermally desorbing the previously deposited carbon nanoparticles from the reactor wall at temperatures greater than 1300 K

289

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

Science.gov (United States)

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

Morin, Pierre; Raymond, Gaetan; Benoit, Daniel; Maury, Patrick; Beneyton, Remi

2012-11-01

290

Water driven stabilization of ZnS nanoparticles prepared by exploding wire technique  

Science.gov (United States)

ZnS nanoparticles, prepared employing exploding wire technique (EWT), demonstrate water-induced stabilization with time. The structural evolution of ZnS nanoparticles and their interaction with the surrounding aqueous media is systematically studied at the three distinct stages of time. The structural properties of nanoparticles were examined by an assortment of characterization techniques. However, in this article we focus on x-ray diffraction (XRD) and x-ray photoelectron spectroscopic (XPS) investigation of nanoparticles. The XRD results indicate transformation of hexagonal phase of prepared ZnS nanocrystals. The lattice constants and strain in ZnS nanoparticles are estimated at each stage of transition. Alteration in crystal structure of ZnS nanoparticles, transforming in presence of water, is an outcome of gradual variation in lattice constants and strain. Variation in stoichiometry of ZnS nanoparticles, at respective stages of transformation, is found through XPS analysis. Furthermore, in order to determine the alterations in the oxidation state and energies of the nanoparticle constituents, line shape analysis of Zn 2p3/2 peaks at three stages, is also performed. Thus, XPS analysis, accompanied with the XRD interpretations, vividly deciphers the structural evolution of ZnS nanoparticles in aqueous environment.

Goswami, Navendu; Sen, P.

2014-04-01

291

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

292

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

293

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

International Nuclear Information System (INIS)

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

294

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Koteswara Rao, D.

2011-01-01

295

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Mohamed Zellagui

2008-01-01

296

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

Energy Technology Data Exchange (ETDEWEB)

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

Koutsokeras, L. E. [Departement Physique et Mecanique des Materiaux, Institut Pprime, CNRS-Universite de Poitiers-ENSMA, UPR 3346, SP2MI, Teleport 2, Bd M et P Curie, F 86962 Chasseneuil-Futuroscope (France); Department of Materials Science and Engineering, University of Ioannina, Ioannina 45110 (Greece); Abadias, G. [Departement Physique et Mecanique des Materiaux, Institut Pprime, CNRS-Universite de Poitiers-ENSMA, UPR 3346, SP2MI, Teleport 2, Bd M et P Curie, F 86962 Chasseneuil-Futuroscope (France)

2012-05-01

297

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

Directory of Open Access Journals (Sweden)

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

Abhisakh Sarma

2014-09-01

298

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

International Nuclear Information System (INIS)

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

299

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.

300

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

 
 
 
 
301

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

Science.gov (United States)

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.

Ataei, M.; Hooshmand, R.; Parastegari, M.

302

Development of an ultrasonic technique for in situ investigating the properties of deposited protein during crossflow ultrafiltration.  

Science.gov (United States)

Although an amount of research has reported that a flux minimum occurs at the isoionic/isoelectric points (pH 4.6-5.0) in the absence of salts in the ultrafiltration of bovine serum albumin (BSA), the real mechanism remains incompletely understood due to the lack of additional techniques in real time to detect the properties of deposited BSA (gel) layers formed during ultrafiltration (UF). An ultrasonic technique was developed as an analytical noninvasive tool to in situ investigate the properties of deposited BSA layers at pH 4.9 (isoionic or isoelectric point, IEP) and 6.9 during crossflow ultrafiltration. The membrane was a polysulfone (PSf) UF membrane with molecular weight cut-off (MWCO) 35 kDa. The feed used was 0.5 g/l BSA solution. Results show good correspondence between the ultrasonic signal responses and the development of BSA gel layers on the membranes. The deposit is thicker at pH 6.9 than at pH 4.9. However, the deposited gel layers are more compressible at pH 4.9 than at pH 6.9. The flux decline is mainly controlled by the density (packing) of the deposit layer. At pH 6.9, protein mainly deposits on the membrane surface. Around the isoelectric point, protein absorbs within and on the membranes. A functional relationship between acoustic signals and fouling resistance exists. The fouling resistance is mainly attributed to pore blocking or pore constriction. PMID:15752807

Li, Jianxin; Sanderson, R D; Chai, G Y; Hallbauer, D K

2005-04-01

303

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

304

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2014-01-01

305

In?situ X-ray spectromicroscopy investigation of the material stability of SOFC metal interconnects in operating electrochemical cells.  

Science.gov (United States)

The present in situ study of electrochemically induced processes occurring in Cr/Ni bilayers in contact with a YSZ electrolyte aims at a molecular-level understanding of the fundamental aspects related to the durability of metallic interconnects in solid oxide fuel cells (SOFCs). The results demonstrate the potential of scanning photoelectron microspectroscopy and imaging to follow in situ the evolution of the chemical states and lateral distributions of the constituent elements (Ni, Cr, Zr, and Y) as a function of applied cathodic potential in a cell working at 650 °C in 10(-6) mbar O(2) ambient conditions. The most interesting findings are the temperature-induced and potential-dependent diffusion of Ni and Cr, and the oxidation-reduction processes resulting in specific morphology-composition changes in the Ni, Cr, and YSZ areas. PMID:21695791

Bozzini, Benedetto; Tondo, Elisabetta; Prasciolu, Mauro; Amati, Matteo; Abyaneh, Majid Kazemian; Gregoratti, Luca; Kiskinova, Maya

2011-08-22

306

Stability  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Reproducibility is imperative for any scientific discovery. More often than not, modern scientific findings rely on statistical analysis of high-dimensional data. At a minimum, reproducibility manifests itself in stability of statistical results relative to "reasonable" perturbations to data and to the model used. Jacknife, bootstrap, and cross-validation are based on perturbations to data, while robust statistics methods deal with perturbations to models. In this article, a...

Yu, Bin

2013-01-01

307

Study of thermal stability of ZnO:B films grown by LPCVD technique  

International Nuclear Information System (INIS)

Zinc oxide thin films with different boron doping levels (ZnO:B) are prepared by low pressure chemical vapor deposition (LPCVD) technique. All films here exhibit a pyramid-like surface texture. Stability of the ZnO:B films is systematically investigated through a post heat treatment at ambient temperatures of 300 °C and 250 °C for different durations. It is found that total transmission (TT) of these films at near infrared (NIR) wavelength range increases with the enhanced thermal treating intensity, which could be attributed to decrease of free carrier concentration inside the films. Moreover, light absorption in NIR wavelength range decreases profoundly with the increasing carrier concentration after a post thermal treatment in particular for highly doped ZnO:B films. However, morphology of these ZnO:B films does not vary after the thermal treatment and thus the corresponding light scattering properties do not change as well. Therefore, the thermally treated ZnO:B films may lead to an increase in light-generated current and resulting a higher cell efficiency due to the enhancement of TT when they work as front contact in silicon thin film solar cells.

308

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

Energy Technology Data Exchange (ETDEWEB)

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 recapture in a more stable solid phase (co-precipitation rather than adsorption). Our specific research objectives include: * Elucidation of the mechanisms and rates for the release of sorbed trace metals and their subsequent sequestration by co-precipitation in calcite induced by urea hydrolysis. * Evaluation at the field scale of the influence of microbial calcite precipitation on the partitioning and retention of strontium and other naturally occurring divalent metals in groundwater. * Identification of specific microbial characteristics that signify subsurface geochemical conditions conducive to ureolytically-driven calcite precipitation.

Smith, Robert W.

2003-06-01

309

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

310

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 SciELO Mexico | Language: English Abstract in spanish 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

311

Aqueous Foams Stabilized by Hydrophilic Silica Nanoparticles via In-Situ Physisorption of Nonionic TX100 Surfactant  

Directory of Open Access Journals (Sweden)

Full Text Available This paper present the study of aqueous CO foam prepared 2 by a mixtures hydrophilic silica nanoparticles and non-ionic Triton X100, TX100, surfactant. The synergistic effects of the mixture on stabilizing the CO2 foam were inferred into few key parameters namely; particles and surfactant concentration, adsorption of surfactant onto the particles via surface tension and adsorption isotherm, foam lifetime and, the size of the bubbles produced. It was found that the adsorption behaviour of TX100 on silica surface exhibit a particular characteristics depend on the concentration of silica, high total surface area available leads to high adsorptionof surfactant molecules. The synergetic performance of silica/TX100 in stabilizing foam can be observed at low (0.01% and intermediate (0.1% concentration of TX100. Lower concentration required low silica concentration while the intermediate concentration required high silica fraction in the dispersion to stabilize the foam.

Suriatie Yusuf

2013-01-01

312

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

Energy Technology Data Exchange (ETDEWEB)

Highlights: Black-Right-Pointing-Pointer Biodegradable surfactant stabilized nanoscale zero-valent iron (NZVI) is tested. Black-Right-Pointing-Pointer Vinyl chloride and 1,2-dichloroethane are remediated by NZVI in the field. Black-Right-Pointing-Pointer Multiple functions of biodegradable surfactants are confirmed. Black-Right-Pointing-Pointer Biodegradable surfactants stabilize NZVI and facilitate the bioremediation. Black-Right-Pointing-Pointer 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 m{sup 2}). VC was effectively degraded by NZVI while the 1,2-DCA degradation was relatively sluggish during the 3-month field test. Nevertheless, as 1,2-DCA is known to resist abiotic reduction by NZVI, the observation of 1,2-DCA degradation and hydrocarbon production suggested a bioremediation took place. ORP and pH results revealed that a reducing condition was achieved at the testing area facilitating the biodegradation of chlorinated organic hydrocarbons. The bioremediation may be attributed to the production of hydrogen gas as electron donor from the corrosion of NZVI in the presence of water or the added biodegradable surfactant serving as the carbon source as well as electron donor to stimulate microbial growth.

Wei, Yu-Ting; Wu, Shian-chee; Yang, Shi-Wei; Che, Choi-Hong [Graduate Institute of Environmental Engineering, National Taiwan University, Taipei, Taiwan, ROC (China); Lien, Hsing-Lung, E-mail: lien.sam@nuk.edu.tw [Department of Civil and Environmental Engineering, National University of Kaohsiung, Kaohsiung, Taiwan, ROC (China); Huang, De-Huang [Chinese Petroleum Corporation, Kaohsiung, Taiwan, ROC (China)

2012-04-15

313

Advanced techniques for the analysis of crisis stability, deterrence, and latency  

Energy Technology Data Exchange (ETDEWEB)

This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The principal results of studies on crisis stability, deterrence, and latency are presented in their order of development. They capture the main features of stability analysis; relate first strike, crisis, and arms control stability as seen from US and Russian perspective; and address whether different metrics, uncertain damage preferences, or the deployment of defenses can be destabilizing. The report explores differences between unilateral and proportional force reductions in the region of deep reductions where concern shifts from stability to latency.

Canavan, G.H.

1998-12-31

314

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

CERN Document Server

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

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

2014-01-01

315

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

Science.gov (United States)

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

Yang, Biwen; Liu, Zhiming; Guo, Zhouyi; Zhang, Wen; Wan, Mingming; Qin, Xiaochu; Zhong, Huiqing

2014-10-01

316

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

International Nuclear Information System (INIS)

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

317

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

Directory of Open Access Journals (Sweden)

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

Brij Bhushan Tewari

2004-06-01

318

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

319

Diagnosis of Sex Chromosome Disorders and Prenatal Diagnosis of Down Syndrome using Interphase Fluorescent In-Situ Hyperidization Technique  

Science.gov (United States)

Background : Thousands of infants are born each year with chromosomal abnormalities that severely impact physical and mental development. Among common genetic disorders are Down syndrome (trisomy 21) and sex chromosomal disorders. Objectives : Evaluation of guidelines used for prenatal diagnosis of Down syndrome (DS) as well as sex chromosomal disorders including interphase Fluorescent In Situ Hyperidization (FISH) technique. Methods : Enrolled cases were among those presenting to Genetics and Neonatology Units, Mansoura and Ain-Shams University hospitals,(Egypt) during 2002 to 2004. These included: Groups 1 comprised fifty pregnant women presenting for genetic counseling. They were subjected to complete history analysis, ultrasound examination in addition to triple screening test (for alpha feto protein (AFP), human chorionic goandotrophin (HCG) and unconjugated esteriol (E2). Results were confirmed by doing routine karyogram on cultured amniotic fluid. Groups 2 comprised suspected cases with sex chromosomal disorders including neonates with ambiguous genitalia (64 cases) and adults with primary amenorrhea (69 cases) or infertility (38 cases). They were subjected to a diagnostic workup including Results : Among the pregnant women group, seven were found to be at a high risk of having DS fetuses including 3 cases with a history of affected off-springs, 2 cases with age above 35 years, and 2 cases with high triple test. Only one case had positive trisomy 21 on interphase FISH confirmed by karyogram on cultured amniotic cells. The other 6 ladies had normal FISH confirmed by karyograms. Regarding the other group, 5 cases out of the 9 females were proved to be feminized males, one proved mosaic turner, one proved mixed gonadal dysgenesis and 2 normal females. On the other hand one out of three males were proved to be verilized female while the other one was a male with incomplete testicular feminization and the last one was a male with infertility diagnosed as Klinefelter syndrome at the age of 26 years. Conclusion : Interphase FISH is a rapid, accurate and very sensitive method in sex chromosom and autosomal abnormalities. It adds to the diagnostic utility of routine cytogenetics and its use on interphase nuclei overcomes the difficulty of conventional cytogenetics. It could be used in the prenatal diagnosis of DS in addition to ultrasonography, and triple test. PMID:21475429

Settin, Ahmad; Abu-Saif, Ibrahem S; El-Baz, Rizk; Dowaidar, Moataz; Kasim, Rabab Abu-Al; Shabana, Shaimaa

2007-01-01

320

Ground-based radiometric calibration of the Landsat 8 Operational Land Imager (OLI) using in situ techniques  

Science.gov (United States)

Landsat 8 was successfully launched from Vandenberg Air Force Base in California on 11 February 2013, and was placed into the orbit previously occupied by Landsat 5. Landsat 8 is the latest platform in the 40-year history of the Landsat series of satellites, and it contains two instruments that operate in the solar-reflective and the thermal infrared regimes. The Operational Land Imager (OLI) is a pushbroom sensor that contains eight multispectral bands ranging from 400-2300 nm, and one panchromatic band. The spatial resolution of the multispectral bands is 30 m, which is similar to previous Landsat sensors, and the panchromatic band has a 15-m spatial resolution, which is also similar to previous Landsat sensors. The 12-bit radiometric resolution of OLI improves upon the 8-bit resolution of the Enhanced Thematic Mapper Plus (ETM+) onboard Landsat 7. An important requirement for the Landsat program is the long-term radiometric continuity of its sensors. Ground-based vicarious techniques have been used for over 20 years to determine the absolute radiometric calibration of sensors that encompass a wide variety of spectral and spatial characteristics. This work presents the early radiometric calibration results of Landsat 8 OLI that were obtained using the traditional reflectance-based approach. University of Arizona personnel used five sites in Arizona, California, and Nevada to collect ground-based data. In addition, a unique set of in situ data were collected in March 2013, when Landsat 7 and Landsat 8 were observing the same site within minutes of each other. The tandem overfly schedule occurred while Landsat 8 was shifting to the WRS-2 orbital grid, and lasted only a few days. The ground-based data also include results obtained using the University of Arizona's Radiometric Calibration Test Site (RadCaTS), which is an automated suite of instruments located at Railroad Valley, Nevada. The results presented in this work include a comparison to the L1T at-sensor spectral radiance and the top-of-atmosphere reflectance, both of which are standard products available from the US Geological Survey.

Czapla-Myers, J.

2013-12-01

 
 
 
 
321

On radiation stability of the advanced for nuclear technique of the construction oxides material  

International Nuclear Information System (INIS)

Full text: Al2O3 oxide (as some metal oxides) is one of the prospective high-k electro-insulators and construction oxides materials, in particular, for the ceramics fuel material and the first wall of thermonuclear reactor. Besides, this oxide is used widely as an active element or substrate for lasers and MOS systems, as a film coating and receiver of IR-radiation. From here this work is aimed at investigation of radiation stability of the physical properties and structure of Al2O3 oxide after irradiation to a high fluence in the reactor. In this connection the peculiarities of radiation effect on lattice parameters (a,c), form and position of several reflections, reflection coefficient and frequency of valence and deformation oscillations of Al-O bonds, electric characteristics of the oxide were studied with techniques of X-diffraction, dielectric and IR-reflection spectroscopy. For example, this communication presents the results on X-ray structure investigation of ? after irradiation to high neutron doses (F). X-diffraction patterns were obtained using a roentgen diffractometer. Particular attention was paid to dynamics of form and positions some representative reflexes. The diffraction patterns showed essential changes of peak intensity and position depending upon F, the Bragg angle 2 ? decreases with an increase in dose, the lattice parameters of crystals ( a, c ) was undergone anisotropy expansion, at very high dose of change this parameters is not so much as ?c= 0,0038 nm and ?a = 0,0014 nm. Besides, it is shown that at these doses some halo appears at the diffraction patterns. The mechanism of atom displacement out of lattice knots plays the main role in radiation damage of crystals irradiated to high doses. The optical characteristics - a reflection coefficient and frequency of valence (736, 614 cm-1 ) and deformation (464 cm-1 ) oscillations of Al-O bonds of the oxide were studied with techniques of IR-reflection spectroscopy in region of frequency 400-1200 cm-1. The decrease of intensity (R) and frequency (? ) of these modes at fluence 8.1019 cm-2 was observed. Some change of these optical (valence and deformation oscillations of Al-O bonds) and structural parameters (the lattice parameters of crystals (a, c) and positions some representative reflexes, of peak intensity and the Bragg angle), a density and a linear size of irradiated samples were found near a neutron fluence 1020 cm-2 and 1021 cm-2, but the structure state remained stable at the following increase of the irradiation dose (at F1.1021 cm-2 and 7.1021 cm-2 and higher). Features of dose and temperature dependencies of electric properties (the conductivity, dielectrical permittivity, dielectrical loss) were determined after influence of different doses of ionizing radiation. Increase of the dielectric permittivity and IR-transmittance was found near temperatures (25-400 oC) and high doses. Besides, at the dose of 103-105 Gy the electric conductivity and at T > 130 oC the dielectrical loss was decreased. Thus, such thermal-radiation treatment may serve as a method leading to the permittivity growth at elevated irradiation doses and temperatures, decrease and improvement of several electric, mechanic and optic characteristics. This is testified to prospect of application of this high-k oxide (Al2O3 oxide) in a composition at other oxides metals in the quality construction, insulation and fuel materials in the reactor, cosmic and semiconductor technique, under the condition of irradiation influence

322

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.

323

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

324

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

Directory of Open Access Journals (Sweden)

Full Text Available OBJECTIVES: To compare bar displacement and complication rates in three retrospective series of patients operated on by the same surgical team. METHOD: A retrospective medical chart analysis of the three patient series was performed. In the first series, the original, unmodified Nuss technique was performed. 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

2011-01-01

325

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

326

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

327

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

Directory of Open Access Journals (Sweden)

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

Mohamed Zellagui

2008-09-01

328

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.

329

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

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

Laurence Couvreur

2007-11-01

330

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

331

Precise frequency stabilization technique for 850nm vertical cavity surface emitting lasers by controlling their optical beat frequency  

Science.gov (United States)

We have demonstrated a compact and inexpensive frequency stabilization technique for commercially available 1mW, 850nm Vertical Cavity Surface Emitting Laser (VCSEL) using a Fabry-Perrot Resonator (FPR) as frequency standard. We have performed frequency discrimination using a transmitted light from FPR, and frequency stabilization has been carried out by electrical negative feedback to injection current. Optical frequency fluctuation of VCSEL is estimated by error signal, and its stability is evaluated by Allan variance. We have achieved to detect optical beat frequency signal of 850nm type VCSEL for the first time, by fabricating two sets of frequency stabilized VCSEL, which are quite similar with each other by controlling each locking frequency. We have estimated VCSEL's frequency accurately fluctuations from the beat signal. As a result, we have successfully suppressed the amount of frequency fluctuations for the free-running VCSEL of as much as 600MHz to be within 80MHz. In this paper, we propose compact, inexpensive and precise frequency stabilization for 850nm VCSEL, and describe an accurate method for estimating its fluctuations.

Ohhara, Takao; Yoshimi, Tomoaki; Sasaki, Wakao

2010-02-01

332

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

333

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

Directory of Open Access Journals (Sweden)

Full Text Available Maintaining synchronism between different parts of power system (PS is getting difficult over time. The fact that growth of interconnected system is a continuous process, also these systems have been extended in different regions. In this research work steady state (SS and transient stabilities along with swing equation and numerical solution using MATLAB / Simulink are studied. This work is done in two steps. In the first step, proper assumptions are made to linearize the system and then, the transfer function models of this system are developed for stability analysis. The performance of proposed linearized model of synchronous machine during normal and disturbed conditions is focused in Matlab/Simulink. This gives the understanding of the transient and dynamic analysis of PS stabilities. In the second step, the proposed methodology of the power system stability (PSS with steady state (including transient and dynamic analysis, the application to sudden increase in power input, and the application of three-phase fault have been examined using Matlab coding (m-files along with simulation models (Simulink. This makes power system stability studies easier to understand. The study also gives good understanding of maintaining reliable position of the system and new design of generating and transmitting plants. Furthermore, it provides information of relaying system and critical clearing time of circuit breakers, voltage levels and transfer capabilities between systems. Use of MATLAB/SIMULINK for this purpose, provides supplement for implementing numerical solution in the field of power system and its analysis for students, engineers and researchers.

Naresh K. Tanwani*1

2014-03-01

334

A novel technique for fabricating in situ Al2O8/Ti(x)Al(y) composites  

Science.gov (United States)

Anatase (TiO2) powders in Al are here used as reactants for the fabrication of in situ composites. DTA, XRD, and SEM are used to characterize reaction results and their associated microstructures. An exothermic reaction between Al and TiO2 occurred in the 738-825 C after the squeeze-cast Al had melted in the 659-675 C range.

Wang, D. Z.; Liu, Z. R.; Yao, C. K.; Yao, M.

1993-09-01

335

New Techniques for Hydrothermal Exploration: In Situ Chemical Sensors on AUVs - Preliminary Results From the Lau Basin  

Science.gov (United States)

Less than one quarter of the global ridge-crest has yet received even cursory investigation for the presence or absence of hydrothermal activity. To improve exploration efficiency, particularly at high latitudes, new methodologies independent of tethered vehicles are required. To that end, we have begun the use of in situ chemical sensors allied to the increasing capabilities of autonomous underwater vehicles. Here, we present first results from our most recent efforts aboard the second R2K cruise to the Lau Basin (C.Langmuir, PI; Autumn 2004) to (a) map non-buoyant hydrothermal plumes, (b) intercept buoyant hydrothermal plumes and (c) locate and image novel hydrothermal fields on the seafloor. The AUV used for this work is ABE and the sensors deployed are direct extensions of the in situ Fe/Mn sensor deployed previously on SOC's AUTOSUB to investigate seasonally-reducing waters in Loch Etive, NW Scotland. Each in situ instrument comprises an electronics package that contains a tattletale control system with a flash memory card for on-board logging and a chemical manifold, consisting of a series of valves, pumps and a colorimetric cell. Analysis of iron is enabled by the determination of the coloured complex formed between iron II and ferrozine, manganese uses the colour change of PAN in the presence of reduced manganese. The system includes capacity for switching between sample, blank and two on-board samples for "in flight" calibrations with blanks and standards held in medical bags, outside of the pressure-balanced manifold, to attain in situ water-column temperatures. An in-line filter prevents large particle clogging and detection limits for both iron II and manganese II are ca.2nM.

German, C. R.; Connelly, D. P.; Prien, R. D.; Yoerger, D.; Jakuba, M.; Bradley, A.; Shank, T. J.; Edmonds, H. N.; Langmuir, C. H.

2004-12-01

336

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

Directory of Open Access Journals (Sweden)

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

Supamattaya, K.

2005-02-01

337

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

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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

338

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

339

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

340

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

International Nuclear Information System (INIS)

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

 
 
 
 
341

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

International Nuclear Information System (INIS)

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

342

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

International Nuclear Information System (INIS)

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

343

Combination of Fluorescence In Situ Hybridization with Staining Techniques for Cell Viability and Accumulation of PHA and polyP in Microorganisms in Complex Microbial Systems  

Science.gov (United States)

Fluorescence in situ hybridization (FISH) can be combined with a number of staining techniques to reveal the relationships between the microorganisms and their function in complex microbial systems with a single-cell resolution. In this chapter, we have focused on staining methods for intracellular storage compounds (polyhydroxyalkanoates, polyphosphate) and a measure for cell viability, reduction of the tetrazolium-based redox stain CTC. These protocols are optimized for the study of microorganisms in waste-water treatment (activated sludge and biofilms), but they may also be used with minor modifications in many other ecosystems.

Nielsen, Jeppe Lund; Kragelund, Caroline; Nielsen, Per Halkjær

344

Comparative studies on properties of scandia-stabilized zirconia synthesized by the polymeric precursor and the polyacrylamide techniques  

International Nuclear Information System (INIS)

ZrO2:Sc2O3 powders were synthesized by the polyacrylamide and the polymeric precursor techniques. The powder particles had the state of agglomeration analyzed by laser scattering, the structural phases by X-ray diffraction, and the morphology by scanning electron microscopy. The polyacrylamide and the polymeric precursor techniques produced stable transparent gels and polymeric resins, respectively. Upon calcination the gels and the resins yielded high surface area powders, fully stabilized in the cubic fluorite structure. The crystalline phases, grain morphology and electrical behavior of sintered pellets using powders synthesized by both techniques were analyzed. The amount of organics in the precursors was found to be responsible for the state of agglomeration of the particles, producing pellets with different electrical behavior.

345

Denuder sampling techniques for the determination of gas-phase carbonyl compounds: a comparison and characterisation of in situ and ex situ derivatisation methods.  

Science.gov (United States)

Two denuder sampling techniques have been compared for the analysis of gaseous carbonyl compounds. One type of denuder was coated with XAD-4 resin and the other type of denuder was coated with XAD-4 and 2,4-dinitrophenylhydrazine (DNPH) to derivatise gaseous carbonyl compounds to their hydrazone forms simultaneously. A detailed protocol for the denuder coating procedure is described. The collection efficiency under dry (RH hydroxyacetone, methacrolein, methylglyoxal, campholenic aldehyde and nopinone. Calibration experiments were performed in a simulation chamber and carbonyl-hydrazone concentrations determined in the extracts of both the denuder types were related to the mixing ratios of gaseous carbonyl compounds in the chamber to overcome losses and errors associating with the denuder sampling, extraction and sample preparation. The application of on-tube conversion for the XAD-4/DNPH denuders resulted in higher R(2) values than the XAD-4 denuder, ranging up to 0.991 for nopinone. The XAD-4-only coated denuders showed acceptable calibration curves only for lower vapour pressure carbonyl compounds though larger relative standard deviations (RSD) were observed. Carbonyl compounds that were formed during the oxidation of nopinone were collected using the XAD-4/DNPH denuders. The results showed that the denuder sampling device was able to provide reproducible nopinone mixing ratios that remained in the chamber after about 1h of the oxidation. One isomer of oxo-nopinones was tentatively identified from off-line HPLC/(-)ESI-TOFMS analysis. Based on the TOFMS response of the nopinone-DNPH derivative, the oxo-nopinone molar yield of 0.7±0.1% (n=3) was determined from the reaction of nopinone with OH radicals. Depending on target analytes, accuracy and sensitivity requirements, the present method can be employed for the determination of gaseous carbonyl compounds that are formed during the oxidation of monoterpenes. PMID:21411383

Kahnt, Ariane; Iinuma, Yoshiteru; Böge, Olaf; Mutzel, Anke; Herrmann, Hartmut

2011-05-15

346

Origin and comprehensive study of Thünen´s model to analyze data from in situ rumen degradability technique / Origen y estudio comprensivo del modelo Thünen para analizar datos de la técnica de degradabilidad ruminal in situ.  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: English Abstract in spanish El modelo clásico utilizado para analizar datos de la técnica de degradabilidad ruminal in situ fue propuesto originalmente por Thünen para el estudio de la respuesta de los cultivos a diferentes factores de producción. Con la finalidad de establecer el significado de la kd en el modelo de Thünen, s [...] e realizó un análisis matemático que indicó que esta constante representa el cociente entre la velocidad y la aceleración de la degradación ruminal. De manera similar, la constante kp representa el cociente entre la velocidad y la aceleración del pasaje ruminal. Abstract in english The classical model utilized to analyze data from in situ rumen degradability technique was originally proposed by Thünen to study the harvests responses to different production factors. In order to settle the meaning of kd in the Thünen´s model, a mathematical analysis was realized which indicated [...] that this constant represents the quotient between the ruminal degradation acceleration and velocity. Similarly, the kp constant represents the quotient between the ruminal passage acceleration and velocity.

Héctor J, Correa.

347

Application of stabilization techniques in the dynamic analysis of multibody systems  

Directory of Open Access Journals (Sweden)

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

Hajžman M.

2007-11-01

348

Stabilization of nonlinear systems with parametric uncertainty using variable structure techniques  

Energy Technology Data Exchange (ETDEWEB)

The authors present a result on the robust stabilization of a class of nonlinear systems exhibiting parametric uncertainty. They consider feedback linearizable nonlinear systems with a vector of unknown constant parameters perturbed about a known value. A Taylor series of the system about the nominal parameter vector coupled with a feedback linearizing control law yields a linear system plus nonlinear perturbations. Via a structure matching condition, a variable structure control law is shown to exponentially stabilize the full system. The novelty of the result is that the linearizing coordinates are completely known since they are defined about the nominal parameter vector, and fewer restrictions are imposed on the nonlinear perturbations than elsewhere in the literature.

Schoenwald, D.A. [Oak Ridge National Lab., TN (United States); Oezguener, Ue. [Ohio State Univ., Columbus, OH (United States). Dept. of Electrical Engineering

1995-07-01

349

Thermal, electrochemical and in-situ structural study of stabilized LiNi{sub y}Co{sub 1-y-z}M{sub z}O{sub 2} (M = Al and Mg) lithium-ion cathode materials prepared by a soft chemistry route  

Energy Technology Data Exchange (ETDEWEB)

Doped LiNi{sub y}Co{sub 1-y-z}M{sub z}O{sub 2}, with M = Al and Mg, and z = 0.04 mole ratio, were prepared using a soft chemistry route. The thermal behaviour of these materials was studied to confirm their stability using differential scanning calorimetry (DSC). The reversibility and rate capabilities of the cathodes in lithium cells were characterized using electrochemical measurements. A recently developed in-situ X-ray technique was used to investigate the structural properties of the oxides upon galvanostatic cycling. The addition of Al and Mg, as dopants, was demonstrated to dramatically improve the stability of LiNi{sub 0.8}Co{sub 0.2}O{sub 2}. (orig.)

D' Epifanio, A.; Traversa, E. [Rome Univ. (Italy). Dipartimento di Sci. e Tecnologie Chimiche; Croce, F.; Ronci, F.; Scrosati, B. [Dept. of Chemistry, Univ. of Rome ' ' La Sapienza' ' , Roma (Italy); Albertini, V.R. [Ist. di Struttura della Materia, CNR, Tor Vergata, Roma (Italy)

2002-07-01

350

Mouthguards: difference in longitudinal dimensional stability between single- and double-laminated fabrication techniques.  

Science.gov (United States)

Though the use of mouthguards (MGs) has increased with the increase in sporting activities, little is known about the influence of their fabrication methods on longitudinal dimensional stability. The objective of this study was to compare the difference in the longitudinal dimensional stability between single and laminated MGs. Single-layer MGs were made from a 4.0 mm thick ethylene vinyl acetate (EVA) sheet and laminated MGs were made from two 2.0 mm thick sheets of EVA. MGs were kept in a 37 degrees C water bath for 60 h, equivalent to the time period of 3-months inter-oral use. MG deformation was analyzed by measuring designated points on the MG border using a profile projector (J-12, Nikon Inc., Tokyo, Japan) before and after the water immersion. A finite-element model was also created to examine the time course of stress accumulation during the sheet forming process using Finite Element software. Longitudinal deformation was smaller in the laminated MGs than in the single-layer MGs in the anterior area (P < 0.05). Finite element method (FEM) analysis also showed the largest stress accumulation in the anterior incisal area where deformations were mainly observed. Laminated double layer MGs have advantages over single-layer MGs in terms of longitudinal stability due to lower stress accumulation during the fabrication process. PMID:17227374

Miura, Jiro; Maeda, Yoshinobu; Machi, Hiroyuki; Matsuda, Shinsuke

2007-02-01

351

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

352

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

353

Study Of Co90Fe10 Magnetic thin Film On MgO Substrate Using In-situ Moke Technique  

International Nuclear Information System (INIS)

Growth behavior of Co90Fe10 film on MgO substrate has been studied. In-situ magneto-optical Kerr effect measurements have been used to study evolution of the magnetic properties of the film with increasing film thickness. Extrapolating linear variation of Kerr signal with film thickness provides the evidence of a magnetic dead layer of thickness 2.2 nm at the interface with MgO substrate. X- ray reflectivity fitting confirms presence of an intermixed layer of about 2 nm.

354

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

International Nuclear Information System (INIS)

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

355

Integration of in situ NDT tests with petro-physical analyses for the characterization of materials and constructive techniques of ancient masonries  

Science.gov (United States)

In the field of the preservation of the architectural heritage, diagnostic investigations, if founded on an interdisciplinary approach, allow to provide a scientific support the diagnosis and the set up of suitable and compatible strategies of interventions. One of the exploited approaches is finalised to find correlations among several investigation techniques, that differ from each other with respect to the degree of invasivity or destructivity, the modalities of implementation (in situ or in laboratory), the kind of output (i.e. physical and mechanical, or chemical and physical). The usefulness of finding correlations is related to the possibility to exploit less and less destructive techniques, that are also cheaper and user friendly, and that allow to achieve direct parameters characterising a certain behaviour of a phenomenology. This paper presents a case study dealing with the application of some integrated in situ and laboratory investigations to the study for the identification and characterisation of ancient masonries. With respect to those built with modern materials, ancient masonries are more complex manufactured issues. Such a complexity is due to their composite characteristics and to the various constructive techniques that characterise them. Further than these factors, the final characteristics are also determined by the nature of the constitutive materials that, being natural stones, comprise a large variety of materials, with extremely different lithologic characteristics. The purpose of this research is to identify a meaningful group of correlated methodologies for the investigation of masonry structures with particular reference to requirements to be non-destructive, exploitable in situ, efficient and user friendly. Both in-situ and laboratory investigation methodologies are exploited. The first ones comprise the transmission of sonic and ultrasonic waves and GPR prospecting, and are applied to the analysis of the masonry structure, also in order to detect possible phenomena that may affect the original conditions, as for example the presence of discontinuities and/or humidity. The laboratory study, instead, is aimed to the identification of the constitutive materials (stone elements and mortars), the determination of their physical and mineralogical-petrographic characteristics, as well as identification of products of decay. The results of the integrated activities, further than providing a contribution with regard to the procedures and the methodologies for the analysis of ancient masonries, provide the basis for the research of correlations between the structural characteristics and those of the constitutive elements. This is important in order to elaborate a model of the behaviour of the masonry tacking into account both the masonry structure and intrinsic features of the constituent materials.

Calia, Angela; Leucci, Gianni; Masini, Nicola; Persico, Raffaele; Quarta, Giovanni

2010-05-01

356

GeneFISH--an in situ technique for linking gene presence and cell identity in environmental microorganisms.  

Science.gov (United States)

Our knowledge concerning the metabolic potentials of as yet to be cultured microorganisms has increased tremendously with the advance of sequencing technologies and the consequent discoveries of novel genes. On the other hand, it is often difficult to reliably assign a particular gene to a phylogenetic clade, because these sequences are usually found on genomic fragments that carry no direct marker of cell identity, such as rRNA genes. Therefore, the aim of the present study was to develop geneFISH - a protocol for linking gene presence with cell identity in environmental samples, the signals of which can be visualized at a single cell level. This protocol combines rRNA-targeted catalysed reporter deposition - fluorescence in situ hybridization and in situ gene detection. To test the protocol, it was applied to seawater samples from the Benguela upwelling system. For gene detection, a polynucleotide probe mix was used, which was designed based on crenarchaeotal amoA clone libraries prepared from each seawater sample. Each probe in the mix was selected to bind to targets with up to 5% mismatches. To determine the hybridization parameters, the T(m) of probes, targets and hybrids was estimated based on theoretical calculations and in vitro measurements. It was shown that at least 30%, but potentially the majority of the Crenarchaeota present in these samples harboured the amoA gene and were therefore likely to be catalysing the oxidation of ammonia. PMID:20629705

Moraru, Cristina; Lam, Phyllis; Fuchs, Bernhard M; Kuypers, Marcel M M; Amann, Rudolf

2010-11-01

357

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.

358

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

CERN Document Server

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

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

2003-01-01

359

In-situ investigation of adsorption of dye and coadsorbates on TiO2 films using QCM-D, fluorescence and AFM techniques  

Science.gov (United States)

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

Harms, Hauke A.; Tétreault, Nicolas; Voitchovsky, Kislon; Stellacci, Francesco; Grätzel, Michael

2013-09-01

360

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

 
 
 
 
361

Formation of Cu2SnSe3 from stacked elemental layers investigated by combined in situ X-ray diffraction and differential scanning calorimetry techniques  

International Nuclear Information System (INIS)

Highlights: • In situ investigation revealed intermetallic compounds and Cu2SnSe3 formations. • CuSe phase dominates binary phase formations at a low annealing temperature. • SnSe forms from liquid phase reaction of Sn and Se. • Binary Cu-selenide phase exerts sequential phase decompositions. • Crystalline Cu2SnSe3 forms above 450 °C. -- Abstract: Stacked elemental layers of Mo/Cu/Sn and Mo/Cu/Sn/Se were employed as samples for investigating the formation reaction of Cu–Sn intermetallic compounds as well as Cu2SnSe3 phases by in situ technique of X-ray diffraction and differential scanning calorimetry. The use of a combined in situ technique allows a real-time observation on solid-state reactions as well as any crystalline phase changes during annealing towards the crystallization of Cu2SnSe3. It is found that Cu and Sn form intermetallic compounds of Cu6Sn5, Cu3Sn and Cu41Sn11 as the annealing temperature rises from 30 to 550 °C. The reaction of Se with Cu to form a CuSe phase dominates the binary phase formation at a low annealing temperature. The annealing of a stacked Mo/Cu/Sn/Se layer suggests that only Cu6Sn5 intermetallic compound directly acts as a reactant for the Cu-selenide phase formation. A SnSe phase mostly forms from a liquid-state reaction of Sn and Se above the Sn melting point. The in situ investigation also reveals a complete set of Cu-selenide peritectic decompositions of CuSe2 ? CuSe ? Cu1.8Se at 360 and 412 °C. The formation of Cu2SnSe3 phase starts at 450 °C as a product from a reaction between Cu1.8Se and SnSe in a presence of liquid Se. Comparisons on the initial formation temperatures of all involved phases and on the formation pathways between Cu2SnSe3 and Cu2SnS3 are discussed as well

362

A Technique to Eliminate External Transport Barriers and Stabilize Fiscal Instabilities  

Science.gov (United States)

The case is made for a coordinated national effort to diffuse plasma science knowledge to the public. Like earlier "fiscal instabilities" in plasma research, the 1995-7 magnetic fusion budget disruption can be attributed to a lack of public awareness about the value of science research, as reflected in the attitude of Congress. Magnetic fusion researchers now create "internal transport barriers" to reduce plasma heat loss, but observations also reveal a problematic "external transport barrier" in all of plasma science - the inadequate diffusion of knowledge beyond the scientists. Public funding creates scientific knowledge for the public good, and now the public cares - and deserves to know - what it pays for. Eliminating the external transport barrier should suppress the fiscal instability: theory predicts that funding should stabilize - or even increase - if the value of plasma science is understood by the bulk of Congress' members before they're elected, rather than just a small population of patrons energetically lobbied in office. If the public understands the value of plasma research, Congress will too. But plasmas are poorly represented in both contemporary classrooms and public perception. To reach the "Lawson Criterion" for ignition of public understanding, we should reach out to the public and to educators nationwide. Education and outreach activities are, and ought to be, part of the professional life of a plasma scientist. Our current activities consist largely of teaching our own classes, writing papers, lobbying Congress, giving lab tours, making Web pages, and promoting education locally; these have been useful, but insufficient. Now we must do better. To stabilize fiscal instabilities for good, we should restructure not only our research programs, but our sense of what it means to be a scientist. We should coordinate our education and outreach activities on a national scale, maximizing impact while minimizing cost in time, labor, and money. To this end our existing education and outreach activities are evaluated, and new activities are suggested. A coordinated education and outreach effort is sketched, involving the DPP, the DOE, labs and universities, and everyone from our senior management to our enthusiastic students. A modification of the professional physics pipeline is proposed to encourage recruitment, retention, and development of scientists who are not only sources of new knowledge, but who also conduct, convect, and radiate their knowledge to others. The implantation of plasma topics and examples into the educational system is advocated, not to make learning harder, but so plasmas are actually treated as the fourth state of matter. If younger scientists adopt this "Coordinated Civic Science" professional spirit, and older scientists and program leaders support it, we should succeed.

Heeter, Robert F.

1997-11-01

363

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

364

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

365

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

366

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

Science.gov (United States)

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

Haas, N P; Schütz, M; Frigg, R; Südkamp, N P; Hoffmann, R

1994-11-01

367

In situ observation of 2212 intergrowths in the early stages of (Bi, Pb)2223 phase formation using the synchrotron XRD technique  

International Nuclear Information System (INIS)

2212 intergrowths in the (Bi, Pb)2223 phase have been investigated using in situ high temperature synchrotron XRD technique. With a high energy synchrotron x-ray and high resolution diffractometer, we could obtain high resolution powder XRD patterns of (Bi, Pb)2223 and (Bi, Pb)2212 from the whole bulk inside the Ag-sheath. This gave us more detailed information on 2212 intergrowths in the (Bi, Pb)2223 phase than ever before. During in situ observation, the Ag-tubed precursor was kept at 1095 K with flowing Ar-7.8% O2 mixed gas. The profiles of the diffraction peaks were analysed by Rietveld analysis to evaluate the isotropic and anisotropic lattice strain of (Bi, Pb)2223 and (Bi, Pb)2212. Considering the evolution of anisotropic lattice strain during the heat treatment, it was concluded that 2212 intergrowths in the (Bi, Pb)2223 phase are not in the untransformed region of (Bi, Pb)2212 after incommensurate intercalation, but a stacking fault-like defect contained in the (Bi, Pb)2223 phase during its nucleation and growth. A new model of 2212 intergrowth formation in the (Bi, Pb)2223 phase was suggested and discussed

368

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

369

In situ observation of columnar-to-equiaxed transition in directional solidification using synchrotron X-radiation imaging technique  

International Nuclear Information System (INIS)

Highlights: ? In situ observation of a columnar-to-equiaxed transition. ? There is a gradual change in the density of the melt at the mush–liquid interface. ? A mechanical analysis on dendrite detachment was carried out. ? The transition was explained based on dendrite detachment and fragment movement. - Abstract: A columnar-to-equiaxed transition (CET) was induced by controlling the cooling rate in the directional solidification of an Al-15 wt.% Cu alloy. The morphological evolution of the mush–liquid interface in CET was tracked and recorded by X-ray imaging. The dendrite growth and detachment, solute distribution at the growth front and excessive solute enrichment in the liquid pockets were clearly observed. Based on the observations, it was found that there is an obvious increase in melt density in the liquid pocket due to the excessive solute enrichment. The density difference between the melt and the solid is an important reason for dendrite detachment and fragment movement, which is considered as the key to the inducement of CET. Finally, the CET process and the growth of equiaxed dendrites at the mush–liquid interface were described from the viewpoint of dendrite detachment.

370

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

Directory of Open Access Journals (Sweden)

Full Text Available Radar wind observations at frequencies between 1.98 and 53.5 MHz obtained at polar latitudes were compared to in-situ wind measurements by radiosondes at tropospheric altitudes and to winds from falling spheres at mesospheric altitudes. Comparisons are shown for several campaigns of radiosonde and falling sphere observations. The radar wind directions agree well to the radiosonde and falling sphere observations and are highly correlated. The winds estimated from radar measurements are less than the radiosonde data by about 15% for spaced antenna observations and by about 10% for the Doppler beam swinging experiment. At mesospheric altitudes the spaced antenna winds obtained from the wide-beam Andenes MF radar are underestimated in the order of 35% and winds from the narrow-beam Saura MF radar are underestimated by about 20% compared to falling sphere winds at altitudes between 70 and 80 km. Furthermore, the relation between wind measurements using narrow-beam and wide-beam antenna arrangements for the MF radars is discussed and VHF radar observations are compared to the wide-beam MF radar.

N. Engler

2008-11-01

371

In situ observation of columnar-to-equiaxed transition in directional solidification using synchrotron X-radiation imaging technique  

Energy Technology Data Exchange (ETDEWEB)

Highlights: Black-Right-Pointing-Pointer In situ observation of a columnar-to-equiaxed transition. Black-Right-Pointing-Pointer There is a gradual change in the density of the melt at the mush-liquid interface. Black-Right-Pointing-Pointer A mechanical analysis on dendrite detachment was carried out. Black-Right-Pointing-Pointer The transition was explained based on dendrite detachment and fragment movement. - Abstract: A columnar-to-equiaxed transition (CET) was induced by controlling the cooling rate in the directional solidification of an Al-15 wt.% Cu alloy. The morphological evolution of the mush-liquid interface in CET was tracked and recorded by X-ray imaging. The dendrite growth and detachment, solute distribution at the growth front and excessive solute enrichment in the liquid pockets were clearly observed. Based on the observations, it was found that there is an obvious increase in melt density in the liquid pocket due to the excessive solute enrichment. The density difference between the melt and the solid is an important reason for dendrite detachment and fragment movement, which is considered as the key to the inducement of CET. Finally, the CET process and the growth of equiaxed dendrites at the mush-liquid interface were described from the viewpoint of dendrite detachment.

Dong Qing [State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhang Jiao, E-mail: zj119@sjtu.edu.cn [State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China); Dong Jinfang [State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China); Xie Honglan; Li Zhijun [Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Shanghai 215600 (China); Dai Yongbing; Liu Yang; Sun Baode [State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China)

2011-12-15

372

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

Energy Technology Data Exchange (ETDEWEB)

Radar wind observations at frequencies between 1.98 and 53.5 MHz obtained at polar latitudes were compared to in-situ wind measurements by radiosondes at tropospheric altitudes and to winds from falling spheres at mesospheric altitudes. Comparisons are shown for several campaigns of radiosonde and falling sphere observations. The radar wind directions agree well to the radiosonde and falling sphere observations and are highly correlated. The winds estimated from radar measurements are less than the radiosonde data by about 15% for spaced antenna observations and by about 10% for the Doppler beam swinging experiment. At mesospheric a