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1

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Negim, Osama

2009-01-01

2

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

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

3

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-09-15

4

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

International Nuclear Information System (INIS)

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

2010-12-01

5

In situ stabilization of entrapped elemental mercury.  

Science.gov (United States)

Elemental mercury is a dense immiscible fluid which gets entrapped as residual mercury in the pore spaces of the subsurface during improper disposals and accidental spills. This paper investigates in situ stabilization of entrapped elemental mercury to mercury sulphide using aqueous sodium polysulphide solution. Batch experiments showed 100% conversion efficiency of elemental mercury to mercury sulphide in a period of 96 h with sodium polysulphide/elemental mercury molar ratio of 1. XRD analysis identified the precipitate formed as mercury sulphide. Micromodel experiments, with glass beads as porous media, further demonstrated in situ stabilization of entrapped mercury under different residual mercury saturations. It was found that in a period of 10 days, 10% of entrapped mercury was stabilized as mercury sulphide, 0.088% was removed as dissolved mercury and the remaining elemental mercury was retained in porous media encapsulated by the newly formed mercury sulphide precipitate. However, there was no leaching of mercury from the micromodel effluent once stabilization was achieved. PMID:24080327

Devasena, M; Nambi, Indumathi M

2013-11-30

6

Laser stabilization technique  

International Nuclear Information System (INIS)

The output power level of a laser is stabilized at a predetermined set point by a feedback control circuit. The light emitted from one end of a laser is detected and converted into an electrical current by a photodetector. This current is then amplified and converted into a proportional voltage by a buffer amplifier and the resultant voltage is compared to a reference voltage to provide an error signal. The error signal is integrated and fed back to correctively adjust the driving current for the laser, thereby compensating for any tendency of the power level of the light beam emitted from the other end of the laser to drift from a predetermined set point. (auth)

1975-01-01

7

In situ vitrification: application analysis for stabilization of transuranic waste  

Energy Technology Data Exchange (ETDEWEB)

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

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

1982-09-01

8

In situ vitrification: application analysis for stabilization of transuranic waste  

International Nuclear Information System (INIS)

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

1982-01-01

9

In-situ stabilization of lead-contaminated soil  

Energy Technology Data Exchange (ETDEWEB)

This paper presents a discussion of the in situ treatment of lead-contaminated soil by first adding stabilization agents to the soil surface and then mixing the soil in-place using conventional soil mixing equipment. Lead stabilization is accomplished by the lead in the soil reacting with the additives to form highly insoluble compounds that are stable in both the natural environment and in the EPA`s TCLP test. The treatment dosage and precise chemistry are established in bench-scale testing, which also includes a demonstration of lead stability under non-acidic leaching conditions. Two case studies of the in-situ stabilization of lead-contaminated soil will be presented--one involving several small lead arsenate pesticide sites, and one involving a lead-acid battery cracking site. Several innovative approaches were used for effective treatment of contaminated soils at both sites. The techniques that were used for chemical delivery, for in-place mixing, for on-site treatment effectiveness monitoring, and for disposition of the treated soil will be discussed in the paper.

Stanforth, R.; Chowdhury, A. [RMT, Inc., Madison, WI (United States)

1994-12-31

10

Remediation of SRS Basins by In Situ Stabilization/Solidification  

International Nuclear Information System (INIS)

In the late summer of 1998, the Savannah River Site began remediation of two radiologically contaminated basins using in situ stabilization. These two high-risk, unlined basins contain radiological contaminants, which potentially pose significant risks to human health and the environment. The selected remedy involves in situ stabilization/solidification of the contaminated wastes (basin and pipeline soils, pipelines, vegetation, and other debris) followed by installation of a low permeability soil cover

1999-01-01

11

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

1996-01-01

12

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

13

Optical metrology techniques for dimensional stability measurements:  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Ellis, Jonathan David

2010-01-01

14

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

International Nuclear Information System (INIS)

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

2012-11-01

15

Efficient technique for measuring laser frequency stability  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

2009-01-01

16

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

17

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

18

In situ hybridization to chromosomes stabilized in gel microdrops  

Energy Technology Data Exchange (ETDEWEB)

Conventional chromosome in situ hybridization procedures rely on fixation to glass slides followed by microscopic evaluation. This report describes the development of a microdrop in situ hybridization (MISH) method which facilitates hybridization to chromosomes in suspension. Chromosomes encapsulated in gel microdrops (GMDs) composed of an agarose matrix withstood stringent hybridization and denaturation conditions. Because of the increased stability, hybridization to encapsulated chromosomes was detected by flow cytometry as well as conventional microscopy. Thus, the MISH method offers a means for chromosome hybridization without slides and may enable identification and isolation of chromosomes using hybridization rather than nucleic acid binding dyes. 36 refs., 6 figs.

Nguyen, Bao-Tram; Lazzari, K.; Abebe, J. [One Cell systems, Inc., Cambridge, MA (United States)] [and others

1995-10-01

19

[In situ gene amplification on tissue sections (in situ PCR). A new technique for pathologists].  

Science.gov (United States)

In situ polymerase chain reaction is a recent technique which combines the sensitivity of PCR reaction to intracellular localization of genomic sequences with the same specificity as in situ hybridization. This reaction is based on the in situ annealing and polymerisation of oligonucleotides complementary to nucleotides located at each side of the target DNA sequence to amplify. We describe the Hot Start PCR (DNA) and the Hot Start PCR after reverse transcription step (RNA). It allows to amplify some nucleic sequences to a high level, becoming easier to detect. The vizualisation can be realized by direct in situ PCR, the product obtained being directly identifiable by incorporation of labeled nucleotides or primers, or preferentially by indirect in situ PCR. In this case, the amplification is followed by in situ hybridization with labeled probes. This last procedure is more specific. Numerous controls are essential at each step of the technique for validating results. PMID:8720848

Walker, F; Bedel, C; Boucher, O; Dauge, M C; Vissuzaine, C; Potet, F

1995-01-01

20

In situ stabilization/fixation of chromium-contaminated soil  

Energy Technology Data Exchange (ETDEWEB)

An electroplating operation at a US Army installation was closed in accordance with Resource Conservation and Recovery Act (RCRA) regulations using in situ stabilization/fixation. Since the plating line was located inside of a building immediately adjacent to other ongoing plating lines, the selected and approved technology involved the use of an electric-powered drill rig retrofitted with a mixing blade auger system, and operated within a negative-pressure enclosure. The stabilization process included the introduction of a reagent mixture developed and defined during in situ pilot tests and stabilization studies. Upon completion of each stabilized/fixed column, representative sampling was conducted to verify the success of the process. Concentrations of chromium using the Toxicity Characteristic Leaching Procedure (TCLP) were reduced from 220 mg/L detected in soils prior to the stabilization/fixation process, to below laboratory detection limits in treated columns. Ultimately, the electroplating collection sump was closed in accordance with the approved closure plan, and the owner constructed a new concrete sump pit fitted with a welded steel sheet containment liner.

Greetis, T.A. [Environmental Quality Management, Inc., Cincinnati, OH (United States); Werntges, W.; Hockenberry, D. [Army Corps of Engineers, Harrisburg, PA (United States)

1996-12-31

 
 
 
 
21

In-situ dewatering techniques for uranium mill tailings  

International Nuclear Information System (INIS)

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

1983-01-01

22

In-situ dewatering techniques for uranium mill tailings  

Energy Technology Data Exchange (ETDEWEB)

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

Wardwell, R.E.; Nelson, J.D.; Abt, S.R.; Staub, W.P.

1983-09-01

23

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

Energy Technology Data Exchange (ETDEWEB)

Polymer-stabilized paramagnetic and fluorescent rare-earth metal sulfide (cerium sulfide, Ce{sub 2}S{sub 3}) nanoparticles have been synthesized by using an 'in situ polymerization and composite formation' (IPCF) technique (Mallick et al. in J. Appl. Phys. 106:074303, 2009) at room temperature. Encapsulated cerium sulfide nanoparticles showed photoluminescence when excited with laser irradiation. The composite material exhibited a paramagnetic behavior due to the in situ formation of magnetic Ce{sup 3+} ionic species at the reaction condition. (orig.)

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

2012-11-15

24

A Technique for In Situ Ballistic Electron Emission Microscopy  

Science.gov (United States)

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

Balsano, Robert; Garramone, John; Labella, Vincent

2012-02-01

25

Femoro-popliteal reconstructions: 'in situ' versus 'reversed' technique.  

Science.gov (United States)

This study examined 191 patients with 'reversed' and 99 patients with 'in situ' femoro-popliteal bypass technique. There were 85 diabetic patients (44.5%) in the group with 'reversed' bypass, and 43 patients (43.43%) in the 'in situ' group. There were 152 (79.68%) smokers in the 'reversed' bypass group, and 80 (80.8%) in the 'in situ' group. The graft patency was confirmed immediately after operation using CW Doppler and then followed up after 1, 6, l2 months and annually thereafter. The statistical analysis was performed using Pearsons chi-square test, Fischer's test and 'Life table' statistic methods. The patients were followed from 3 to 10 yr after surgery. 'In situ' bypass showed better patency than the 'reversed' bypass technique but only in the second and tenth follow-up year (P 0.05). However, continuous smoking after the operation significantly decreased late patency rate in both groups of patients (P 0.05). The early thrombectomy, however, significantly reduced late patency rate in both groups (P < 0.01). Therefore we suggest 'in situ' bypass in cases with poor run off, small-calibre vein and 'long' bypass. Also, we consider important more frequent physical and Doppler ultrasonographic control in patients who had early thrombectomy. PMID:11420160

Davidovic, L B; Markovic, D M; Vojnovic, B R; Lotina, S I; Kostic, D M; Cinara, I S; Cvetkovic, S D; Jakovljevic, N S

2001-08-01

26

Single wound, in situ tying technique for iris repair.  

Science.gov (United States)

The authors describe a technique for placing and tying interrupted iris sutures in virtually any area of the iris using only a single limbal paracentesis wound. The tying is performed with conventional knot-forming techniques outside the eye before the throws are pulled into the anterior chamber and tightened with the desired 180 degrees tension on the suture ends. During suture tying, the iris stays in situ rather than being stretched and distorted. PMID:9824870

Ogawa, G S; O'Gawa, G M

1998-11-01

27

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2012-10-01

28

A novel natural analog in situ stabilization agent  

International Nuclear Information System (INIS)

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

1995-01-01

29

Synthesis of divalent europium borate via in situ reductive techniques.  

Science.gov (United States)

A new divalent europium borate, Eu[B8O11(OH)4], was synthesized by two different in situ reductive methodologies starting with a trivalent europium starting material in a molten boric acid flux. The two in situ reductive techniques employed were the use of HI as a source of H2 gas and the use of a Zn amalgam as a reductive, reactive surface. While both of these are known reductive techniques, the title compound was synthesized in both air and water which demonstrates that strict anaerobic conditions need not be employed in conjunction with these reductive methodologies. Herein, we report on the structure, spectroscopy, and synthetic methodologies relevant to Eu[B8O11(OH)4]. We also report on a europium doping study of the isostructural compound Sr[B8O11(OH)4] where the amount of doped Eu(2+) ranges from 2.5 to 11%. PMID:23822558

Polinski, Matthew J; Cross, Justin N; Villa, Eric M; Lin, Jian; Alekseev, Evgeny V; Depmeier, Wulf; Albrecht-Schmitt, Thomas E

2013-07-15

30

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

1982-01-01

31

Transient technique for in-situ thermal property measurements  

Energy Technology Data Exchange (ETDEWEB)

A technique was developed to measure in-situ thermal properties effectively. It makes use of the early transient temperature behavior at the borehole wall in response to the constant heat supply in the borehole. The use of early phase is appropriate since the assumption of cylindrical radial heat flow holds with a good accuracy. To determine the thermal properties of the medium, the theoretical temperature behavior in the Laplace domain was compared with the measured temperature behavior transformed into the Laplace domain. Field data from Avery Island was used for practical application.The obtained thermal properties were subsequently substituted in the nondimensional result given by Carslaw and Jaeger and also used as input parameters in a finite element analysis. The measured temperature behavior was closely reproduced.

Yamada, S.E.

1982-06-01

32

In situ solidification/stabilization pilot study for the treatment of coal tar contaminated soils and river sediments  

International Nuclear Information System (INIS)

Coal tar contamination was encountered at a former coal gasification site in soils below the groundwater table, and in the sediments of the adjacent river. Ex situ remediation techniques at this site would be costly because of the need to dewater the impacted media. In situ solidification/stabilization was tested to evaluate its effectiveness. Treatability testing was performed to evaluate a Portland cement/fly ash binder system with added stabilizing agents. Results were sufficiently promising to warrant pilot testing. Grout containing Portland cement, fly ash, organically modified clay, and granular activated carbon was pilot tested at the site. Test specimens were collected and tested to evaluate durability, compressive strength, and permeability. The samples were extracted by several methods and analyzed to measure the leachable concentrations of organic compounds and metals. Results indicated acceptable physical characteristics. Leachable concentrations of most polynuclear aromatic compounds were decreased

1993-11-01

33

Bacterial Biotransformations for the In situ Stabilization of Plutonium  

Energy Technology Data Exchange (ETDEWEB)

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

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

2005-04-20

34

Bacterial Biotransformations for the In situ Stabilization of Plutonium  

International Nuclear Information System (INIS)

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

2005-04-18

35

Contributions to fuzzy polynomial techniques for stability analysis and control  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The present thesis employs fuzzy-polynomial control techniques in order to improve the stability analysis and control of nonlinear systems. Initially, it reviews the more extended techniques in the field of Takagi-Sugeno fuzzy systems, such as the more relevant results about polynomial and fuzzy polynomial systems. The basic framework uses fuzzy polynomial models by Taylor series and sum-of-squares techniques (semidefinite programming) in order to obtain stability guarantees...

Pitarch Pe?rez, Jose? Luis

2014-01-01

36

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

Science.gov (United States)

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

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

2013-01-01

37

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

38

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

Science.gov (United States)

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. PMID:22016643

Ahmad, Mansor Bin; Gharayebi, Yadollah; Salit, Mohd Sapuan; Hussein, Mohd Zobir; Shameli, Kamyar

2011-01-01

39

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

International Nuclear Information System (INIS)

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

1997-01-01

40

Well completion for in situ heating oil recovery technique  

Energy Technology Data Exchange (ETDEWEB)

This paper discussed thermal well completion technologies for use in Venezuela's heavy and extra-heavy oil reservoirs. A review and comparison of thermal well completions was conducted and a specialized software program was used to select appropriate well completion technologies for an oilfield in Venezuela's Orinoco oil belt. The study focused on in situ combustion (ISC) methods that inject air into the reservoir while igniting the oil to generate a combustion front. The method was shown to increase oil mobility and facilitate its displacement towards production wells. Cemented and perforated liners were evaluated in this study along with methods for preparing injection wells. Methods of controlling sand production during ISC were also discussed and steam flooded and ISC well completion techniques were compared. The thermal loads for well completions undergoing ISC processes were analyzed. A tubing stress analysis was also presented. It was concluded that the simulations validated the proposed ISC well completion strategy. 6 refs., 4 tabs., 4 figs.

Chacon, O. [PDVSA Petroleos de Venezuela SA, Caracas (Venezuela, Bolivarian Republic of). INTEVEP

2009-07-01

 
 
 
 
41

In-situ stabilization of the Geiger (C and M Oil) Superfund Site  

International Nuclear Information System (INIS)

The Geiger (C and M Oil) Superfund Site is the first US Army Corps of Engineers managed soil remediation project which utilized the in-situ stabilization/solidification technique to remediate the soil. This project involved the remediation of approximately 23,000 cubic yards of contaminated soil. Contaminants of concern included chromium, lead, PCB'S, toluene, benzene, and other organic compounds. Clean-up criteria for the stabilized material was equal to the National Primary Drinking Water Regulations, when tested using the TCLP leachate extraction method. Chromium, lead, and toluene were the main contaminants of concern, with TCLP clean-up goals of 150, 15 and 1,000 parts per billion (ppb), respectively. This National Priorities List (NPL) site is located near Charleston, SC and was an abandoned old waste oil facility that utilized unlined shallow trenches for the storage of waste oil. This paper summarizes the initial testing programs and the final production work at the site. Extensive testing was performed throughout all phases of the project. This testing was performed for the purpose of mix optimization, quality assurance, and verification testing. Specific parameters tested included: TCLP testing of organics, metals and PCBs, permeability testing, and unconfirmed compression strength

1994-12-01

42

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

CERN Multimedia

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

43

Technique for stabilization of detected x-radiation flux  

International Nuclear Information System (INIS)

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

1979-01-01

44

????????? ???????? ?????? ???????? ???????????? ????????????? ???????? 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. ???????????? ???????? ?????? ? ??????????????? ?????????? ???????????? ????????????? ????????. ???????????? ?????????? ????????? ???????????? ??????????? ????????????? ????????. ???????? ?????????????? ????????????? ?????????? ??????????? ??? ??????????? ???????? ?????? ??????? ?? ?????????. ????????? ???????? ????????. ????????? ???????????? ?? ?? ?????????????.

Eugenya P. Pugachevskaya

2009-04-01

45

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

Science.gov (United States)

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

46

IN SITU ELLIPSOMETRY, A MEASUREMENT TECHNIQUE FOR DYNAMIC FILM CHARACTERIZATION AND PROCESS DEVELOPMENT  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In situ ellipsometry enables "on line" continuous monitoring of film development within the deposition chamber. Furthermore in situ ellipsometry not only provides thickness monitoring, but is an excellent tool for determining refractive index and absorption coefficients. Advantages and disadvantages of in situ ellipsometry are shown and compared with other techniques. Examples of transparent PECVD film growth are shown as well as an example of a-Si as a highly absorbing film.

1991-01-01

47

In situ interface analysis by ion backscattering/channeling technique using a thin window cell  

International Nuclear Information System (INIS)

In situ analysis of solid-liquid and solid-gas interfaces by high energy ion backscattering/channeling technique have been investigated. Using thin single crystal windows like that of Si in a specially constructed cell, the backscattered yield and the channeling minimum yield have been utilized to obtain in situ information on solid-gas and solid-liquid interfaces. Examples in the application of this technique to investigate the in situ etching damage at the interface in the dry etching of Si have been given. Experimental results are given which demonstrate the potential application of this technique in the field of catalysis and electrochemistry. (author)

1987-03-01

48

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

49

Mechanistic studies of localized corrosion of Al alloys by high resolution in-situ and ex-situ probing techniques  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A multi-analytical approach based on in-situ and ex-situ local probing techniques was employed to investigate localized corrosion mechanisms of some aluminum alloys in chloride containing solutions, focusing on the influence of intermetallic particles (IMPs) in the alloys. In the EN AW-3003 alloy, SEM-EDS analysis revealed constituent and dispersoid IMPs. There are two types of constituent IMPs, with size ranging from 0.5 to several ?m, and composition typically Al6(Fe,Mn) or Al12(Mn,Fe)3Si,...

2007-01-01

50

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

1994-01-01

51

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

52

Implanter Source Life and Stability Improvement Using In-Situ Chemical Cleaning  

International Nuclear Information System (INIS)

Current 300 mm fabs rely heavily on automation to provide manufacturing efficiency. While implant processes and equipment follow this trend, tool availability and maintenance cycles are often driven by the ion source and adjacent areas which suffer from premature failures due to unwanted material deposits. While working in a high volume production environment, side by side comparative data has been collected on two tools running similar processes, with one tool having integrated in-situ cleaning cycles and the other with no in-situ cleaning. This paper will discuss significant improvements achieved in beam stability, glitch rate, ion source lifetime and maintenance cycles which were achieved on the tool with integrated in-situ cleaning. A program was established at Texas Instruments' DMOS6 wafer fab in early 2007 to explore and document process and equipment performance. Other critical areas, such as particle and metals contamination will be discussed with inferences as to potential yield improvements.

2008-11-03

53

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

Science.gov (United States)

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

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

2013-11-26

54

Single Molecule Techniques for Advanced in situ Hybridization  

Energy Technology Data Exchange (ETDEWEB)

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

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

2003-02-03

55

Single Molecule Techniques for Advanced in situ Hybridization  

International Nuclear Information System (INIS)

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

2003-01-01

56

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-11-15

57

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

International Nuclear Information System (INIS)

Highlights: ? Insitu Raman is used to monitor the thermal stability of Wells Dawson heteropolyacid. ? TP-Raman follows the gradual dehydration and the effect on the secondary structure. ? Wells-Dawson heteropolyacid does not decompose into Keggin and WO3 units below 600oC -- Abstract: The present investigation applies laser Raman spectroscopy under in situ conditions to obtain insights on the effect of the temperature on the molecular structure of the bulk phosphotungstic Wells-Dawson heteropoly-acid H6P2W18O62.xH2O (HPA). The in situ temperature-programmed studies followed the evolution of phosphotungstic Wells-Dawson and Keggin heteropoly-acids along with tungsten trioxide under controlled atmosphere and temperature. The spectroscopic investigation of the Wells-Dawson HPA demonstrated that in situ Raman spectroscopy is a suitable technique to follow the effect of a gradual dehydration on the secondary structure of such a complex structure. Moreover, the absence of the signals belonging either to the Keggin or WO3 phases provides further evidence that the phosphotungstic heteropolyanion does not decomposes towards those materials at temperatures below 600 oC.

2011-11-01

58

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2006-02-15

59

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

2008-04-01

60

Thermal stability of in situ synthesized (TiB + La2O3)/Ti composite  

International Nuclear Information System (INIS)

Highlights: ? The material is in situ synthesized (TiB + La2O3)/Ti composite. ? The TRIPLEX heat treatment is adopted. ? The thermal stability of titanium matrix composites is investigated. ? The decrease of thermal stability is attributed to the precipitation of Ti3Al and silicides. ? The reinforcements can improve thermal stability of titanium matrix composites. - Abstract: Thermal stability of in situ synthesized (TiB + La2O3)/Ti composite is investigated. The phase analysis is identified by X-ray diffraction. Microstructure of the melted and forged titanium matrix composites (TMCs) after heat treatment is characterized by means of optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The room temperature tensile properties after an additional thermal exposure at 873 K, 923 K or 973 K for 100 h are tested. After the thermal exposure, the strength of specimen increases and ductility decreases. This is attributed to precipitation of ordered ?2 phase (Ti3Al) and S1 (silicide) in the titanium matrix composites after the thermal exposure.

2011-06-15

 
 
 
 
61

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

1989-12-02

62

Tuning of power system stabilizers using optimization techniques  

Energy Technology Data Exchange (ETDEWEB)

The application of a numerical optimization scheme to the tuning of power systems stabilizers is studied. The scheme is based in minimax optimization techniques with multiple objectives given by relevant system perturbations, aggregated by means of a weighted sum. The large number of constraints is handled by separating the optimization and simulation in two levels which interchange limited information. Three different optimization techniques were tested with applications to the Venezuelan power system for the years 1989 and 20005. The overall method is shown to be accurate and reliable.

Urdaneta, A.J.; Feijou, B. (Univ. Simon Bolivar, Caracas (VE)); Bacalao, N.J.; Flores, L. (C.V.G. Electrificacion del Caroni C.A. (VE)); Diaz, R. (OPSIS (VE))

1991-02-01

63

In situ aberration measurement technique based on quadratic Zernike model  

Science.gov (United States)

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

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

2012-12-01

64

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

1979-11-19

65

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

66

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

1997-01-01

67

In situ frequency calibration technique of FM reflectometer  

International Nuclear Information System (INIS)

A frequency modulation (FM) reflectometer is designed to linearly sweep the microwave frequency in order to diagnose the plasma density profile. The static characteristic curve of the frequency versus the control voltage can be easily measured by using a spectrum analyzer. However, it is not guaranteed that the characteristic curve will be the same when the frequency is swept. A technique is devised which measures the dynamic characteristics by using the reflectometer itself. The results show that the shape of the characteristic curve does not depend on the sweep rate but on the time delay between the control voltage of the function generator and the microwave frequency at the detector input. This time delay should be compensated. Based on this measured characteristic curve, the frequency sweep rate and the distance between the antenna and the vacuum chamber are experimentally determined

2006-04-01

68

Using geophysical techniques to control in situ thermal remediation  

International Nuclear Information System (INIS)

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

1994-03-27

69

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

International Nuclear Information System (INIS)

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

2010-09-15

70

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

71

Stabilization and acidic dissolution mechanism of single-crystalline ZnO(0001) surfaces in electrolytes studied by in-situ AFM imaging and ex-situ LEED.  

Science.gov (United States)

A combined approach of pH-dependent in-situ AFM topography and ex-situ LEED studies of the stability and dissolution of single-crystalline ZnO(0001)-Zn surfaces in aqueous media is presented. Hydroxide-stabilized and single-crystalline ZnO(0001)-Zn surfaces turned out to be stable within a wide pH range between 11 and 4 around the point of zero charge of pH PZC = 8.7 +/- 0.2. Hydroxide stabilization turned out to be a very effective stabilization mechanism for polar oxide surfaces in electrolyte solutions. The dissolution of the oxide surface started at an acidic pH level of 5.5 and occurred selectively at the pre-existing step edges, which consist of nonpolar surfaces. In comparison, the oxide dissolution along the ZnO(0001) direction proved to be effectively inhibited above a pH value of 3.8. On the basis of these microscopic observations, the mechanistic understanding of the acidic dissolution process of ZnO could be supported. Moreover, both the in-situ AFM and the ex-situ LEED studies showed that the stabilization mechanism of the ZnO(0001) surfaces changes in acidic electrolytes. At pH values below 3.8, the hydroxide-stabilized surface is destabilized by dissolution of the well-ordered radical3. radical3. R30 hydroxide ad-layer as proven by LEED. Restabilization occurs and leads to the formation of triangular nanoterraces with a specific edge termination. However, below pH 4 the surface structure of the crystal itself is ill-defined on the macroscopic scale because preferable etching along crystal defects as dislocations into the bulk oxide results in very deep hexagonal etching pits. PMID:18439031

Valtiner, Markus; Borodin, Sergiy; Grundmeier, Guido

2008-05-20

72

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

International Nuclear Information System (INIS)

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

2008-02-01

73

In situ techniques for the characterization and monitoring of a radioactively contaminated site for in situ vitrification  

International Nuclear Information System (INIS)

A treatability study was in October 1993 to evaluate the application of in situ vitrification (ISV) to an old seepage pit used for the disposal of radioactive liquid waste at the Oak Ridge National Laboratory (ORNL). This pit is one of seven inactive seepage pits and trenches at ORNL. During the 3 months that the pit was operated as a disposal facility, it is estimated to have received approximately 398 curies of mixed fission products, primarily 137Cs, 90Sr, and 106Ru. Based on data from analysis of sludge from another pit, the activities for waste sludge in Pit 1 decay corrected to 1993 have been roughly estimated to be 71 and 17.5 curies of 137Cs, and 90Sr, respectively. The 106Ru, with a half-life of 367 days, has decayed completely in the 42 years since its disposal in the pit Earthen fill material was added to the pit in 1981, and the pit area was then covered with an approximately 4--6 inch thick asphalt surface. Because so little information necessary for the effective and safe ISV of Pit 1 was available, the first phasm of the treatability study focused on site characterization activities. Several in-situ techniques were developed and used during characterization to ascertain the pit's lateral and vertical dimensions hydraulic and hydrologic properties, soil composition, contaminant inventory, and lateral and vertical distribution of radionuclides. At the end of the treatability study, this characterization effort will be evaluated to determine which properties were the most useful for designing and controlling the ISV process. Such information will be invaluable in efficiently and safely gathering characterization data for the remediation of the other seepage pits and trenilim at ORNL via ISV or alternative remediation techniques. This abstract briefly describes some of the major components of the field characterization activities and their results

1995-10-08

74

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

75

Review of techniques for measuring soil moisture in situ. Special report  

Energy Technology Data Exchange (ETDEWEB)

Recently there has been an increased interest in the in-situ measurement of soil moisture content in the areas of hydrology, meteorology, agriculture and environmental studies. Current methods generally have limitations, depending upon the use of the data, that greatly influence acquisition and reliability of the soil moisture determination. This report discusses gravimetric, nuclear, electromagnetic, tensiometric and hygroscopic techniques and the advantages and disadvantages of using the technique. Emphasis is placed on the tensiometric and electromagnetic techniques. These two measurements when coupled together would supply information on the wetting and drying soil moisture characteristic curves and thereby provide a means of tracing moisture movement under field conditions in cold climates.

McKim, H.L.; Walsh, J.E.; Arion, D.N.

1980-08-01

76

Analysis on Supporting Stability for Track Subgrade Dynamic Response In-situ Test Device Based on NSGA-II  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The dynamic response test to the subgrade plays a very important role in railway construction and a new in-situ test system is proposed. This paper presents the application of non-dominated sorting genetic algorithm-II (NSGA-II) to analyze the stability of the supporting equipment for track subgrade dynamic response in-situ test device. Its stability is related with the extension length of the hydraulic cylinders and the backward condition of the supporting equipment - the hydraulic excav...

2013-01-01

77

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

1997-01-01

78

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

79

Hybrid Video Stabilization Technique for Hand Held Mobile Videos  

Directory of Open Access Journals (Sweden)

Full Text Available The videos taken from hand held mobile cameras suffer from different undesired slow motions like track, boom or pan. Hence it is desired to synthesis a new stabilized video sequence, by removing the undesired motion between the successive frames. Most of the previous methods assumes the camera motion model hence have limitation to process gorse motion. The efficiency of feature based methods depend on the ability of feature point selection and might cause temporal inconsistency in case of fast moving object in static scene. By taking consideration of slow motion limitation; the paper proposed a hybrid video stabilization technique using hierarchical differential global motion estimation and combination of gaussian kernel filtering is then added to eliminate accumulation error. The method is simple and computationally efficient, and is experimented on the large variety of videos taken in real time environment with different motions. It is found that proposed method not only effectively removes the undesired motion, but also minimizes the missing frame area.

Prof. Paresh Rawat

2011-05-01

80

Optical Fiber Technique for Remote Stabilization of RF Phase  

Science.gov (United States)

We demonstrate an optical-fiber-based technique to deliver a radio-frequency reference phase to a remote location. Using a reflected portion of the RF amplitude-modulated optical signal from the remote location in a feedback loop, we show that the remote phase can be kept within ± 0.3° of the desired value, independent of temperature variations along a fiber length of 2 km or more. The instrument is designed to operate at 416 MHz, and works satisfactorily over a ± 10% RF bandwidth. In addition, an automatic phase ranging circuit allows the device to maintain phase stabilization over an infinite number of phase cycles. The system is presently being installed at the Molonglo Observatory Synthesis Telescope near Canberra, Australia.

Krug, Peter A.; Large, Michael I.; Davison, Ralph G.

1999-04-01

 
 
 
 
81

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.

2011-01-01

82

Nuclear techniques for in situ evaluation of coal and mineral deposits  

International Nuclear Information System (INIS)

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

1993-12-01

83

Study of formation process of metal nanoparticles on metal oxides by in-situ XAFS technique  

International Nuclear Information System (INIS)

The formation process of platinum nanoparticles (PtNPs) on metal oxide (SiO2) was investigated by various characterization techniques, especially, in situ time-resolved Pt-L3 edge XAFS (QXAFS and DXAFS) combined with Q-Mass spectroscopy. A series of XAFS spectra was analyzed to evaluate the change in local structure, electronic state, and dispersion of PtNPs during their formation and growth process.

2013-04-22

84

Study of formation process of metal nanoparticles on metal oxides by in-situ XAFS technique  

Science.gov (United States)

The formation process of platinum nanoparticles (PtNPs) on metal oxide (SiO2) was investigated by various characterization techniques, especially, in situ time-resolved Pt-L3 edge XAFS (QXAFS and DXAFS) combined with Q-Mass spectroscopy. A series of XAFS spectra was analyzed to evaluate the change in local structure, electronic state, and dispersion of PtNPs during their formation and growth process.

Shishido, T.; Nasu, H.; Deng, L.; Teramrua, K.; Tanaka, T.

2013-04-01

85

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

86

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

Science.gov (United States)

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

Bellopede, R.; Marini, P.

2012-04-01

87

DEVELOPMENT OF IN SITU TECHNIQUES FOR TORSION AND TENSION TESTING IN HYDROGEN ENVIRONMENT  

Energy Technology Data Exchange (ETDEWEB)

Reliability of hydrogen storage tanks is significantly influenced by the mechanical performance of the container materials in the hydrogen environment. Fracture behavior and fracture toughness are of specific interest since they are relevant to many catastrophic failures. However, many conventional fracture testing techniques are difficult to be realized under the presence of hydrogen. Thus it is desired to develop novel in situ techniques to study the fracture behavior of structural materials in hydrogen environments. In this study, special testing apparatus were designed to facilitate in situ fracture testing in H2. In addition to a multi-notch tensile fixture, a torsional fixture was developed to utilize an emerging fracture testing technique, Spiral Notch Torsion Test (SNTT). The design concepts will be discussed. Preliminary in situ testing results indicated that the presence of H2 significantly reduces the fracture toughness of 4340 pipeline steels by up to 50 percent. On the other hand, SNTT tests conducted in air demonstrated a significant fracture toughness reduction in samples subject to Gleeble heat treatment, which illustrated the effect of welding on the fracture toughness of this material.

Wang, Jy-An John [ORNL; Ren, Fei [ORNL; Zhang, Wei [ORNL; Feng, Zhili [ORNL; Anovitz, Lawrence {Larry} M [ORNL; Chen, Zhe [Michigan State University, East Lansing; Xu, Hanbing [ORNL

2011-01-01

88

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

89

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

90

Radiation stability of ceramic waste forms determined by in situ electron microscopy and He ion irradiation  

International Nuclear Information System (INIS)

The radiation stability of polyphase titanate ceramic waste forms was studied using analytical transmission electron microscopy, in combination with in situ irradiation by 30 keV He+ ions, followed by staged annealing. Two experiments were conducted. In the first, a reconnaissance investigation was made of the stabilities of the synthetic minerals hollandite, zirconolite, and perovskite when subjected to a total dose of 1.8 x 1017 He+ cm-2. It was found that all phases amorphized at approximately the same rate, but perovskite recovered its structure more rapidly and at lower temperatures than the other phases. In particular, annealing for 10 minutes at 1000 degrees C was sufficient for perovskite to completely regain its crystallinity, while zirconolite and hollandite were only partially restored by these conditions. In the second experiment, the response of a thin hollandite crystal to irradiation was examined by selected area electron diffraction. At a dose of 1.5 x 1015 He+ cm-2 its incommensurate superstructure was disrupted, but even at a dose of 3 x 1016 He cm-2 the hollandite subcell was largely intact. For this dose, total recovery was achieved by annealing for 1 minute at 1000 degrees C

1993-12-03

91

Radiation stability of ceramic waste forms determined by in situ electron microscopy and He ion irradiation  

Energy Technology Data Exchange (ETDEWEB)

The radiation stability of polyphase titanate ceramic waste forms was studied using analytical transmission electron microscopy, in combination with in situ irradiation by 30 keV He{sup +} ions, followed by staged annealing. Two experiments were conducted. In the first, a reconnaissance investigation was made of the stabilities of the synthetic minerals hollandite, zirconolite, and perovskite when subjected to a total dose of 1.8 x 10{sup 17} He{sup +} cm{sup {minus}2}. It was found that all phases amorphized at approximately the same rate, but perovskite recovered its structure more rapidly and at lower temperatures than the other phases. In particular, annealing for 10 minutes at 1000{degrees}C was sufficient for perovskite to completely regain its crystallinity, while zirconolite and hollandite were only partially restored by these conditions. In the second experiment, the response of a thin hollandite crystal to irradiation was examined by selected area electron diffraction. At a dose of 1.5 x 10{sup 15} He{sup +} cm{sup {minus}2} its incommensurate superstructure was disrupted, but even at a dose of 3 x 10{sup 16} He cm{sup {minus}2} the hollandite subcell was largely intact. For this dose, total recovery was achieved by annealing for 1 minute at 1000{degrees}C.

White, T.J. [Univ. of South Australia, Ingle Farm (Australia); Mitamura, H.; Hojou, K.; Furuno, S. [Japan Atomic Energy Research Institute, Ibaraki (Japan)

1994-12-31

92

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

International Nuclear Information System (INIS)

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

2008-08-01

93

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 H_3BO_3. 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)

1997-02-01

94

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

Science.gov (United States)

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

95

In situ aberration measurement technique based on principal component analysis of aerial image.  

Science.gov (United States)

We propose a novel in situ aberration measurement technique for lithographic projection lens by use of aerial image based on principal component analysis (AMAI-PCA). The aerial image space, principal component space and Zernike space are introduced to create a transformation model between aerial images and Zernike coefficients. First the aberration-induced aerial images of measurement marks are simulated to form an aerial image space with a statistical Box-Behnken design pattern. The aerial image space is then represented by their principal components based on principal component analysis. The principal component coefficients of the aerial images are finally connected with Zernike coefficients by a regression matrix through regression analysis. Therefore in situ aberration measurement can be achieved based on the regression matrix and the principal component coefficients of the detected aerial images. The measurement performance of the proposed AMAI-PCA technique is demonstrated superior compared to that of the conventional TAMIS technique by using a lithographic simulator tool (Prolith). We also tested the actual performance of AMAI-PCA technique on a prototype wafer exposure tool. The testing results show our proposed technique can rapidly measure the aberrations up to high-order Zernike polynomial term with 1? repeatability of 0.5 nm to 2.3 nm depending on the aberration type and range. PMID:21935174

Duan, Lifeng; Wang, Xiangzhao; Bourov, Anatoly Y; Peng, Bo; Bu, Peng

2011-09-12

96

Clinical application for the preservation of phospho-proteins through in-situ tissue stabilization  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Protein biomarkers will play a pivotal role in the future of personalized medicine for both diagnosis and treatment decision-making. While the results of several pre-clinical and small-scale clinical studies have demonstrated the value of protein biomarkers, there have been significant challenges to translating these findings into routine clinical care. Challenges to the use of protein biomarkers include inter-sample variability introduced by differences in post-collection handling and ex vivo degradation of proteins and protein modifications. Results In this report, we re-create laboratory and clinical scenarios for sample collection and test the utility of a new tissue stabilization technique in preserving proteins and protein modifications. In the laboratory setting, tissue stabilization with the Denator Stabilizor T1 resulted in a significantly higher yield of phospho-protein when compared to standard snap freeze preservation. Furthermore, in a clinical scenario, tissue stabilization at collection resulted in a higher yield of total phospho-protein, total phospho-tyrosine, pErkT202/Y204 and pAktS473 when compared to standard methods. Tissue stabilization did not have a significant effect on other post-translational modifications such as acetylation and glycosylation, which are more stable ex-vivo. Tissue stabilization did decrease total RNA quantity and quality. Conclusion Stabilization at the time of collection offers the potential to better preserve tissue protein and protein modification levels, as well as reduce the variability related to tissue processing delays that are often associated with clinical samples.

Ding Wei

2010-11-01

97

Use of Atomic Layer Deposition to Improve the Stability of Silver Substrates for In-Situ, High Temperature SERS Measurements  

Energy Technology Data Exchange (ETDEWEB)

A method to stabilize silver surface-enhanced Raman spectroscopy (SERS) substrates for in-situ, high temperature applications is demonstrated. Silver island films grown by thermal evaporation were coated with a thin layer (from 2.5nm to 5nm) of alumina by atomic layer deposition (ALD), which protects and stabilizes the SERS-active substrate without eliminating the Raman enhancement. The temporal stability of the alumina-coated silver island films was examined by measurement of the Raman intensity of rhodamine 6G molecules deposited onto bare and alumina-coated silver substrates over the course of thirty-four days. The coated substrates showed almost no change in SERS enhancement while the uncoated substrates exhibited a significant decrease in Raman intensity. To demonstrate the feasibility of the alumina-coated silver substrate as a probe of adsorbates and reactions at elevated temperatures, an in-situ SERS measurement of calcium nitrate tetrahydrate on bare and alumina-coated silver was performed at temperatures ranging from 25 C to 400 C. ALD deposition of an ultrathin alumina layer significantly improved the thermal stability of the SERS substrate thus enabling in-situ detection of the dehydration of the calcium nitrate tetrahydrate at elevated temperature. Despite some loss of Raman signal, the coated substrate exhibited greater thermal stability compared to the uncoated substrate. These experiments show that ALD can be used to synthesize stable SERS substrates capable of measuring adsorbates and processes at high temperature.

John, Joshy [ORNL; Mahurin, Shannon Mark [ORNL; Dai, Sheng [ORNL; Sepaniak, Michael [University of Tennessee, Knoxville (UTK)

2010-01-01

98

New insights into the formation of microporous materials by in situ scattering techniques.  

Science.gov (United States)

The formation of zeolite A (LTA) in the presence of tetramethylammonium cations and CoA1PO-5 (AFI structure) in the presence of tetraethyl ammonium hydroxide was studied using time-resolved, in situ energy dispersive X-ray diffraction (EDXRD) and small angle and wide angle X-ray scattering (SAXS/WAXS) techniques. The in situ SAXS measurements show the formation of homogeneous precursors, ca. 10 nm in size, prior to the crystallization of LTA, and consumed during the crystallization. The crystal size is estimated by fitting the SAXS patterns with an equation for a cubic particle, and it is revealed that the final crystal size of the LTA depends on the synthesis temperature. The crystallisation of CoA1PO-5 occurs through the formation of poly-dispersed particles with an average size of the precursor particle of ca. 50 nm. PMID:17955808

Sankar, Gopinathan; Okubo, Tatsuya; Fan, Wei; Meneau, Florian

2007-01-01

99

Planetary Geochemistry Techniques: Probing In-Situ with Neutron and Gamma Rays (PING) Instrument  

Science.gov (United States)

The Probing In situ with Neutrons and Gamma rays (PING) instrument is a promising planetary science application of the active neutron-gamma ray technology so successfully used in oil field well logging and mineral exploration on Earth. The objective of our technology development program at NASA Goddard Space Flight Center's (NASA/GSFC) Astrochemistry Laboratory is to extend the application of neutron interrogation techniques to landed in situ planetary composition measurements by using a 14 MeV Pulsed Neutron Generator (PNG) combined with neutron and gamma ray detectors, to probe the surface and subsurface of planetary bodies without the need to drill. We are thus working to bring the PING instrument to the point where it can be flown on a variety of surface lander or rover missions to the Moon, Mars, Venus, asteroids, comets and the satellites of the outer planets.

Parsons, A.; Bodnarik, J.; Burger, D.; Evans, L.; Floyd, S.; Lin, L.; McClanahan, T.; Nankung, M.; Nowicki, S.; Schweitzer, J.; Starr, R.; Trombka, J.

2011-01-01

100

In situ formation of magnetite reactive barriers in soil for waste stabilization  

Energy Technology Data Exchange (ETDEWEB)

Reactive barriers containing magnetite and methods for making magnetite reactive barriers in situ in soil for sequestering soil contaminants including actinides and heavy metals, organic materials, iodine and technetium are disclosed. According to one embodiment, a two-step reagent introduction into soil takes place. In the first step, free oxygen is removed from the soil by separately injecting into the soil aqueous solutions of iron (II) salt, for example FeCl.sub.2, and base, for example NaOH or NH.sub.3 in about a 1:1 volume ratio. Then, in the second step, similar reagents are injected a second time (however, according to about a 1:2 volume ratio, iron to salt) to form magnetite. The magnetite formation is facilitated, in part, due to slow intrusion of oxygen into the soil from the surface. The invention techniques are suited to injection of reagents into soil in proximity to a contamination plume or source allowing in situ formation of the reactive barrier at the location of waste or hazardous material. Mixing of reagents to form. precipitate is mediated and enhanced through movement of reagents in soil as a result of phenomena including capillary action, movement of groundwater, soil washing and reagent injection pressure.

Moore, Robert C. (Edgewood, NM)

2003-01-01

 
 
 
 
101

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

1997-02-09

102

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

103

Electrochemical and in situ ellipsometric investigation of the permeability and stability of layered polyelectrolyte films  

Energy Technology Data Exchange (ETDEWEB)

Utilization of layered polyelectrolyte films as sensor or iron-separation materials will depend critically on their stability and ion permeability in aqueous solution. The authors report electrochemical and in situ ellipsometric studies on the permeability and stability of poly(allylamine hydrochloride)/poly(styrenesulfonate) (PAH/PSS) and PAH/poly(acrylic acid) (PAA) films. The permeability of these layered polyelectrolyte films to Fe(CN){sub 6}{sup 3-} and Ru(NH{sub 3}){sub 6}{sup 3+} depends on the solution pH, the number of bilayers in the film, whether supporting electrolyte is present during film deposition, and the nature of constituent polycations and polyanions. Cyclic voltammetry and impedance spectroscopy show that film permeability is similar in pH 3.2- and pH 6.3-buffered solutions but increases dramatically in alkaline solutions. In situ ellipsometry helps to explain these results. Upon immersion in pH 3.2 and pH 6.3-buffered solutions, the thickness of PAH/PSS films increases by 40%, but swelling is constant over time. At pH 10, these films initially swell by 40% but then continue to swell for several minutes before delaminating. The onset of increased swelling corresponds with dramatic increases in film permeability. Both peak current (cyclic voltammetry) and charge-transfer resistance (ac impedance) depend nonlinearly on the number of polyelectrolyte bilayers. The structure of the first two bilayers is more porous than that of later bilayers. Adding supporting electrolyte to deposition solutions results in thicker bilayers and changes film permeability. For PAH/PSS films, the use of supporting electrolyte during film formation results in a much less permeable film (comparing films of similar thickness). In PAH/PAA films, however, the use of supporting salt results in highly permeable films (even with thicknesses as high as 44 nm). Thus proper choice of constituent polyelectrolytes and deposition conditions permits control over the permeability of layered polyelectrolyte films.

Harris, J.J.; Bruening, M.L.

2000-02-22

104

In situ removal of the pipeline embolization device: the 'corking' and 'pseudo-corking' techniques.  

Science.gov (United States)

The pipeline embolization device (PED) is a revolutionary tool for the endovascular treatment of intracranial aneurysms by flow diversion. Treatment using the PED often requires considerable manipulation and customization by the neurointerventionalist at the time of deployment. Proper use of the PED involves a novel set of techniques and associated jargon, which must be learned by all neurointerventionalists, fellows and residents for safe treatment of patients with this device. In this report, the PED removal techniques referred to as 'corking' and 'pseudo-corking' are described. Corking is used for the removal of a partially deployed in situ PED when the pusher wire is intact whereas 'pseudo-corking' is used if the pusher wire is fractured or disconnected. Knowledge of both techniques is necessary for withdrawing the PED in situations of malposition or failed expansion. PMID:22362818

Colby, Geoffrey P; Gomez, Juan F; Lin, Li-Mei; Paul, Alexandra R; Coon, Alexander L

2013-03-01

105

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

International Nuclear Information System (INIS)

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

1998-11-01

106

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Akbar Taghizadeh; Nemati Zabihollah

2008-01-01

107

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 m"3 of transuranic (TRU) waste is co-mingled with over 170,000 m"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

1997-02-09

108

International Waste Technologies/Geo-Con in-situ stabilization/solidification: Applications analysis report  

Energy Technology Data Exchange (ETDEWEB)

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. A demonstration was held at a General Electric Co. electric service shop in Hialeah, Florida. Conclusions were reached concerning the technology's suitability for use in cleanups of various contaminants and at different locations. The conclusions drawn from the available data are that: (1) immobilization of polychlorinated biphenyls (PCBs) appears likely, although due to low leachate concentrations for both the treated and untreated soils as a result of the low PCB concentrations in soil encountered in most of the tests, it cannot be confirmed; (2) heavy metals can probably be immobilized; (3) volatile organics can be reduced to low concentrations in treated soil leachates, but the ability to immobilize is not clear; and (4) a small volume increase on the order of magnitude of 5%-10% can be expected.

Sawyer, S.

1990-08-01

109

In-situ stabilization/solidification of PCB (polychlorinated biphenyls)-contaminated soil  

Energy Technology Data Exchange (ETDEWEB)

An evaluation was performed of the International Waste Technologies 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. A demonstration was held at a General Electric Co. electric service shop in Hialeah, Florida which provided the bulk of the information for the technology evaluation. Conclusions were reached concerning the technology's suitability for use in cleanups of various contaminants and at different locations: immobilization of polychlorinated biphenyls (PCBs) appears likely, although due to low leachate concentrations for both the treated and untreated soils, a result of the low soil concentrations encountered in most of the tests, it cannot be confirmed; heavy metals can probably be immobilized; volatile organics can be reduced to low concentrations in treated-soil leachates, but the ability to immobilize is not clear; a small volume increase on the order of magnitude of 5-10% can be expected; the solidified material shows satisfactory physical properties, with high unconfined compressive strengths, moderately low permeabilities, and satisfactory integrity for the wet/dry samples, but unsatisfactory integrity for the freeze/thaw samples; and microstructural results indicate a dense, low-porosity, homogeneous mass, indicating a potential for long-term durability.

Sawyer, S.; Stinson, M.K.

1989-01-01

110

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

International Nuclear Information System (INIS)

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

1987-10-01

111

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

Energy Technology Data Exchange (ETDEWEB)

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

Jacobs, G.K.; Spalding, B.P.; Carter, J.G.; Koegler, S.S.

1987-01-01

112

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

113

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

2000-01-01

114

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

115

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

116

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

International Nuclear Information System (INIS)

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

2000-01-01

117

"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

118

Voltage stability evaluation of real power transmission system using singular value decomposition technique  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Voltage stability is an important factor that needs to be taken into consideration during the planning and operation of power systems in order to avoid voltage collapse and subsequently partial or full system blackout. This paper presents singular value decomposition (SVD) technique to assess voltage stability of Qatar power transmission system. A MATLAB program has been developed for SVD technique. The voltage stability of the system has been analyzed during the peak load condition of summer...

Ellithy, K.; Shaheen, M.; Al-athba, M.; Al-subaie, A.; Al-mohannadi, S.; Al-okkah, S.; Abu-eidah, S.

2008-01-01

119

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. [University of Massachusetts, Amherst

2012-11-28

120

Enhanced luminescence of Eu3+ by Gd3+ in ternary chelate doped in gel glasses via in situ technique  

International Nuclear Information System (INIS)

Rare-earth ternary chelates EuXGd1-X(TFA)3(TPPO)2 (X=0.2, 0.3, 0.4,...,1.0) were synthesized in gel glasses via in situ technique. Corresponding pure chelates were also synthesized for a comparative investigation and were characterized with Fourier transform infrared (FTIR) absorption spectra and elemental analysis. Photoluminescence (PL) properties of the in situ chelates in gel glasses and the pure chelates have been studied comparatively. It is found that the enhanced luminescence of Eu3+ ions by Gd3+ ions (energy transfer from Gd3+ ions to Eu3+ ions) occurs in both pure and in situ ternary chelates

2006-06-01

 
 
 
 
121

In situ lift-out dedicated techniques using FIB-SEM system for TEM specimen preparation.  

Science.gov (United States)

The recent emergence of the focused ion-beam (FIB) microscope as a dedicated specimen preparation tool for transmission electron microscopy (TEM) has extended the reach of TEM to a wider variety of problems in materials science. This paper highlights three examples of using FIB-SEM lift-out techniques for preparing site-specific and crystallographic orientation-specific thin-foil specimens. An in situ lift-out technique used to extract thin foils from across a local grain boundary in bulk Al alloy and from individual fine Al atomised powder particles (down to 20?m in diameter) was performed with real-time secondary electron imaging within the chamber of a FIB-SEM system. In conjunction with electron backscatter diffraction (EBSD), the FIB is used for extracting TEM foil with a specific crystallographic orientation aligned normal to the broad plane of the foil. The above technique has been demonstrated using a dual-phase Ti-Si alloy for the exploration of orientation relationship between constituent phases. Furthermore, it is suggested that FIB is more applicable for preparing thin foils from hydrogen-sensitive metals (such as titanium alloys) than conventional thinning techniques, which tend to induce ambiguous artifacts in these foils. PMID:22664233

Tomus, Dacian; Ng, Hoi Pang

2013-01-01

122

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2003-01-01

123

Increased process stability for CVD tungsten via in-situ particle monitoring and upstream process control  

Science.gov (United States)

Upstream control and in-situ defect monitoring have been successfully implemented to track and improve particle performance for CVD tungsten films. An in-situ 'dark field' particle sensor was used to monitor process defect levels during tungsten deposition. The sensor was mounted directly below the CVD tungsten deposition chamber on the foreline. Information from the in-situ particle sensor and the CVD system process parameter analog output were routed to a stand alone computer where the incoming signals were recorded. In-situ particle and process parameter signals were monitored using the standard production recipe for tungsten deposition. From this data the internal variables (process parameters) affecting in-situ particle levels were determined. The internal factors were varied over a selected operating range and the in-situ particle levels quantified for each factor. These results were used to define the CVD tungsten process operating window in terms of in-situ defectivity. Additionally, other external sources were identified as contributors to in-situ defectivity.

Huber, Karl; Desanti, Tim; Felker, Steve

1996-09-01

124

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-08-15

125

Thermal stability of in situ synthesized (TiB + La{sub 2}O{sub 3})/Ti composite  

Energy Technology Data Exchange (ETDEWEB)

Highlights: {yields} The material is in situ synthesized (TiB + La{sub 2}O{sub 3})/Ti composite. {yields} The TRIPLEX heat treatment is adopted. {yields} The thermal stability of titanium matrix composites is investigated. {yields} The decrease of thermal stability is attributed to the precipitation of Ti{sub 3}Al and silicides. {yields} The reinforcements can improve thermal stability of titanium matrix composites. - Abstract: Thermal stability of in situ synthesized (TiB + La{sub 2}O{sub 3})/Ti composite is investigated. The phase analysis is identified by X-ray diffraction. Microstructure of the melted and forged titanium matrix composites (TMCs) after heat treatment is characterized by means of optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The room temperature tensile properties after an additional thermal exposure at 873 K, 923 K or 973 K for 100 h are tested. After the thermal exposure, the strength of specimen increases and ductility decreases. This is attributed to precipitation of ordered {alpha}{sub 2} phase (Ti{sub 3}Al) and S{sub 1} (silicide) in the titanium matrix composites after the thermal exposure.

Li Jiuxiao; Wang Liqiang; Qin Jining; Chen Yifei [State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China); Lu Weijie, E-mail: luweijie@sjtu.edu.cn [State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhang Di [State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China)

2011-06-15

126

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 formulation...

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

2013-01-01

127

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

Science.gov (United States)

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

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

1992-01-01

128

Formation and microstructure of an in situ aluminum composite by oxygen spray technique  

Energy Technology Data Exchange (ETDEWEB)

In situ particulate-reinforced Al and Al-Mg matrix composites were successfully fabricated by an oxygen spray technique. The results indicate that Al{sub 2}O{sub 3} and MgAl{sub 2}O{sub 4} particles directly nucleate and grow via gas-liquid oxidation reaction. The Al{sub 2}O{sub 3} particles with the size of 0.1 to 0.5 {micro}m are formed into the Al melt, according to an appropriate system and processing parameters. The reinforcements show a good wettability with the matrix. The hot-rolling process results in an improvement of the uniformity of the particle distribution in the matrix and an increase in the hardness of the composites.

Ji, Y.; Gao, X.; Zhong, T. [Beijing Polytechnic Univ. (China). School of Materials Science and Engineering

1999-04-01

129

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

130

In situ Elemental Analysis of Ancient Objects Using Prompt Gamma-Ray Measurement Techniques  

International Nuclear Information System (INIS)

Full text: In this research, measurement of prompt gamma-rays from neutron capture and inelastic scattering of neutrons was experimentally investigated to be used for in situ qualitative analysis of elements in ancient objects. A 1.85 GBq Am241/Be neutron source, a portable high purity germanium detector with a relative efficiency of 30 % and an Inspector 2000 spectrum analyzer connected to a portable microcomputer. In laboratory, 12 test specimens were analyzed including metals, chemicals, mortar, as well as Buddha images and a bronze bell. In the field, a Buddha image at Wat Naphramain in Ayuthaya Province was analyzed. The results indicated that the technique was capable of analysing some elements such as B, Al, Si, Cl, Ca, Cu, Fe and Pb but was not sensitive to some elements like Sn and Au

2007-08-16

131

In situ preparation of fluorescent CdTe quantum dots with small thiols and hyperbranched polymers as co-stabilizers  

Science.gov (United States)

A new strategy for in situ preparation of highly fluorescent CdTe quantum dots (QDs) with 3-mercaptopropionic acid (MPA) and hyperbranched poly(amidoamine)s (HPAMAM) as co-stabilizers was proposed in this paper. MPA and HPAMAM were added in turn to coordinate Cd2+. After adding NaHTe and further microwave irradiation, fluorescent CdTe QDs stabilized by MPA and HPAMAM were obtained. Such a strategy avoids the aftertreatment of thiol-stabilized QDs in their bioapplication and provides an opportunity for direct biomedical use of QDs due to the existence of biocompatible HPAMAM. The resulting CdTe QDs combine the mechanical, biocompatibility properties of HPAMAM and the optical, electrical properties of CdTe QDs together.

Shi, Yunfeng; Ma, Zhimin; Cui, Ningning; Liu, Yanli; Hou, Xiaoyu; Du, Weimin; Liu, Lin; Gangsheng, Tong

2014-03-01

132

Synthesis of magnesia stabilized zirconia by co-precipitation technique  

International Nuclear Information System (INIS)

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

2002-09-11

133

A new in situ III?V surface characterization technique: chemical modulation spectroscopy  

Science.gov (United States)

A new in situ technique for the study of the molecular beam epitaxy (MBE) growth process of III-V compounds based on the chemical modulation of the surface has been developed. In this technique, the anisotropic optical reflectivity is modulated by a periodic variation of the surface stoichiometry induced by using group V pulsed molecular beams. Pulses are produced by valved pulsed cells for group V elements (As, P, Sb) that we use for atomic layer molecular beam epitaxy (ALMBE) growth. The substrate is maintained at sufficiently high temperature in order to obtain rapid desorption of group V molecules from surface during flux interruptions, and the process is monitorized by reflection high energy electron diffraction (RHEED). Linearly polarized light, reflected at near normal incidence by the sample, is collected independently along one of the two principal axes of the crystal, [1 1 0] and [1 1¯ 0]. This technique has been applied to the surfaces of epitaxial (1 0 0) layers of GaP, GaAs, GaSb, InP, InAs, and InSb grown by MBE. Spectra in the 1-3 eV range show well defined peaks for light polarized along [1 1 0] and [1 1¯ 0] directions, parallel to group III and group V dimers, at specific energies for each compound.

Postigo, P. A.; Utzmeier, T.; Armelles, G.; Briones, F.

1997-05-01

134

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 (6â??3,000 mg).

Pind, Peter Frode; Angelidaki, Irini

2002-01-01

135

A rapid colour stabilization technique for radiochromic film dosimetry  

International Nuclear Information System (INIS)

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

1998-10-01

136

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

137

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.

138

Improved stability of "naked" gold nanoparticles enabled by in situ coating with mono and multivalent thiol PEG ligands.  

Science.gov (United States)

Unprotected ("naked") gold nanoparticles with high monodispersity ([d], 5.5± 0.5 nm) were obtained in a facile and single-step microwave-assisted hydrolytic decomposition of the molecular precursor [NMe4][Au(CF3)2]. Given their chloride-free surface chemistry, the as-obtained gold nanoparticles were in situ functionalized with mono-, di-, and trivalent thiolated PEG ligands in order to study the influence of multivalent character of the ligands on the stability of the colloidal solutions. For this purpose, a novel tridentate ligand was synthesized and the previously reported syntheses of mono- and divalent thiol ligands were improved. Owing to the pristine character of the Au nanoparticles no ligand exchange was required, and the colloidal and chemical stability of the mono- and multivalent functionalized particles purely depended on the ligating ability of the thiolated groups. In situ-functionalized Au nanoparticles showed a strikingly (2 orders of magnitude higher) improved stability against small nucleophiles such as sodium cyanide compared to gold nanoparticles coated with citrate ligands and functionalized via a ligand-exchange reaction. The monovalent thiol PEG ligand produced most stable colloids against cyanide, which is explained by a strongly increased numerical ligand-density on the surface. Gold colloids stabilized by di- and trivalent ligands exhibited high stability in aqueous solutions with high NaCl concentrations (2 M) in contrast to those functionalized with the monovalent PEG ligand, which were only temporally stable in dilute NaCl solutions. The beneficial effect of the multivalence of the ligands was further demonstrated by the incorporation of an additional chelating ligand (dithiothreitol) to the colloidal dispersions. PMID:23906521

Zopes, David; Stein, Benjamin; Mathur, Sanjay; Graf, Christina

2013-09-10

139

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

International Nuclear Information System (INIS)

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

2006-09-11

140

An in situ technique for the assessment of adhesive properties of a joint under load  

DEFF Research Database (Denmark)

Slow crack propagation in adhesive bonded joints has been characterised using an asymmetric wedge test. Crack position was evaluated from strain gauge measurements, both in the debonded part of the joint and in the bonded zone. Test temperature was changed during loading, giving insight into bond evolution. The technique allows accurate, and virtually continuous, determination of crack position to be made, and therefore the evaluation of crack speed versus fracture energy curves, as well as elastic properties of the adhesive layer. This technique also enables the monitoring of crack propagation in controlled environmental conditions to be performed, without interruption of exposure for measurements. By using a Winkler elastic foundation model to analyse results, the method seems to be the first to describe a process zone, or region where the adhesive is significantly strained under load, and a finite length specimen effect, manifested by crack front acceleration during the final stage of the test. The method was found to offer great potential to study in situ fracture and bulk adhesive properties.

Budzik, Michal Kazimierz; Jumel, J.

2011-01-01

 
 
 
 
141

In situ aberration measurement technique based on an aerial image with an optimized source  

Science.gov (United States)

An in situ aberration measurement technique based on an aerial image with an optimized source is proposed. A linear relationship between the aerial image and Zernike coefficients is established by the principal components and regression matrices, which are obtained in a modeling process through principal component analysis (PCA) and regression analysis. The linear relationship is used to extract Zernike aberrations from the measured aerial image in a retrieval process. The characteristics of regression matrix are analyzed, and the retrieval process of Zernike coefficients is optimized. An evaluation function for the measurement accuracy of Zernike aberrations is proposed, and then a fast procedure to optimize the illumination source is designed. Parameters of the illumination source are optimized according to the evaluation function and applied in our method. The simulators Dr.LiTHO and PROLITH are used to validate the method. Compared to the previous aberration measurement technique based on principal component analysis of an aerial image (AMAI-PCA), the number terms of Zernike coefficients that can be measured are increased from 7 to 27, and the measurement accuracy of Zernike aberrations is improved by more than 20%.

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

2013-06-01

142

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

1980-01-01

143

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

International Nuclear Information System (INIS)

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

2000-07-01

144

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

International Nuclear Information System (INIS)

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

1997-02-09

145

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

146

Stability of thin film glasses of toluene and ethylbenzene formed by vapor deposition: an in situ nanocalorimetric study.  

Science.gov (United States)

Vapor deposited thin films (~100 nm thickness) of toluene and ethylbenzene grown by physical vapor deposition show enhanced stability with respect to samples slowly cooled from the liquid at a rate of 5 K min(-1). The heat capacity is measured in situ immediately after growth from the vapor or after re-freezing from the supercooled liquid at various heating rates using quasi-adiabatic nanocalorimetry. Glasses obtained from the vapor have low enthalpies and large heat capacity overshoots that are shifted to high temperatures. The stability is maximized at growth temperatures in the vicinity of 0.8 T(g) for both molecules, although glasses of ethylbenzene show superior stabilization. Our data is consistent with previous results of larger organic molecules suggesting a generalized behavior on the stability of organic glasses grown from the vapor. In addition, we find that for the small molecules analyzed here, slowing the growth rate below 0.1 nm s(-1) does not result in increased thermodynamic stability. PMID:20944849

Leon-Gutierrez, Edgar; Sepúlveda, Alfonso; Garcia, Gemma; Clavaguera-Mora, Maria Teresa; Rodríguez-Viejo, Javier

2010-11-28

147

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.

2012-07-01

148

Drying of a charge-stabilized colloidal suspension in situ monitored by vertical small-angle X-ray scattering.  

Science.gov (United States)

We report a first application of vertical small-angle X-ray scattering to investigate the drying process of a colloidal suspension by overcoming gravity related restrictions. From the observation of the drying behavior of charge-stabilized colloidal silica in situ, we find the solidification of the colloidal particles exhibits an initial ordering, followed by a sudden aggregation when they overcome an electrostatic energy barrier. The aggregation can be driven not only by capillary pressure but also by thermal motion of the particles. The dominating contribution is determined by the magnitude of the energy barrier at the transition, which significantly decreases during drying due to an increased ionic strength. PMID:23875615

Kim, Sunhyung; Hyun, Kyu; Kim, Yun Soo; Struth, Bernd; Clasen, Christian; Ahn, Kyung Hyun

2013-08-13

149

Fabrication of CdS nanocrystals embedded in copolymer matrix by an in situ simultaneous copolymerization-sulfidation technique  

International Nuclear Information System (INIS)

Nanocomposite of poly (styrene-co-vinyl acetate) (PSV)/CdS was prepared by the in situ simultaneous copolymerization-sulfidation technique with CS2 as the sulfur source through the hydrothermal process. The obtained materials were characterized by FT-IR, XRD, TEM, ultraviolet-visible and fluorescence spectroscopy

2003-03-15

150

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

151

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

152

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

153

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

Directory of Open Access Journals (Sweden)

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

Hamilton Varela

2000-10-01

154

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

Science.gov (United States)

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. PMID:23063916

Speranza, M; Wierzchos, J; De Los Rios, A; Perez-Ortega, S; Souza-Egipsy, V; Ascaso, C

2012-11-15

155

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

156

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

Energy Technology Data Exchange (ETDEWEB)

Industrial and mining pollutants discharged into water are in general distributed homogeneously and we investigated a prompt neutron activation technique for the in-situ analysis, to start with of Hg content in water. The laboratory test employed a {sup 252} Cf neutron source (of {approx} 3 x 10{sup 6} n/s fluence) submerged in a test tank of water of {approx} 500 litres, and to monitor the gamma-ray emission a 4 x 4 NaI (Tl) detector system was employed. In 3000 is time interval trials, for a 46 ppm contamination level of Hg, we observed an excess of counts of {approx} 9.2 {sigma} significance in the energy range of 4000-6500 keV, which can be attributed to the presence of mercury. This test system for a 10 hour monitoring can provide a minimum detectable sensitivity at 4.78 ppm. In the future experiments, we propose to replace the NaI(Tl) detector by a HPGe detector to facilitate simultaneous analyses of pollutants such as cadmium, chlorine, chromium etc for detection at few tenths to tens of ppm levels or better. (author). 5 refs., 2 figs., 2 tabs.

Khouri, M.C. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil); Jayanthi, K.A. [Centro Tecnico Aeroespacial (CTA-IEAv), Sao Jose dos Campos, SP (Brazil). Inst. de Estudos Avancados; Jayanthi, U.B. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil); Pascholati, P.R. [Sao Paulo Univ., SP (Brazil). Inst. de Fisica

1995-12-31

157

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

Science.gov (United States)

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

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

2006-09-01

158

[Percutaneous stabilization of thoracolumbar fractures. Techniques of fracture reduction and spinal cord decompression].  

Science.gov (United States)

Minimally invasive percutaneous instrumentations are increasingly being used for stabilization of thoracolumbar fractures, mainly due to the advantages of reduced soft tissue damage. While percutaneous instrumentation can be generally used in less displaced fractures, it remains controversial whether such techniques should also be performed in patients with severe fracture dislocation. This includes patients with severe traumatic kyphosis and/or dislocation in the coronar plane, particularly in concomitant neurological deficits that require additional decompression surgery. Here we show the different indirect fracture reduction techniques in three cases with severe fracture dislocation and discuss the use of percutaneous stabilization techniques in combination with an additional midline approach for decompressing laminectomy. PMID:23149881

Gühring, T; Raible, C; Matschke, S

2013-08-01

159

Use of noninvasive geophysical techniques for the in situ vitrification program  

Energy Technology Data Exchange (ETDEWEB)

In situ vitrification (ISV) is a waste pit remediation technology that can potentially eliminate the need for pit excavation. The ISV program at the Idaho National Engineering Laboratory (INEL) funded this study to evaluate geophysical techniques that might be useful for performing detailed screening of the materials, soil conditions, and local geology of waste pits targeted for remediation. The evaluation focusses on a specific set of characterization objectives developed by ISV engineers. The objectives are based on their assessment of safety, environmental, and cost efficiency issues associated with the ISV process. A literature review of geophysical case histories was conducted and a geophysical survey was performed at the INEL simulated waste pit so that the evaluation could be based on demonstrable results. The literature review shows that all the ISV objectives are theoretically achievable because they involve physical properties (such as electrical conductivity, density, or magnetization) that can be sensed by geophysical instruments. However, most of the ISV objectives require substantially higher resolution than is achieved in typical waste site investigations, or than has been demonstrated by researches using state-of-the-art techniques. The survey at the INEL simulated waste pit yielded useful, qualitative information on subsurface materials and boundaries; but quantitative information, such as depth, size, or composition of buried materials, was subject to significant uncertainty. For ISV, the usefulness of geophysical characterization depends both on the capabilities of geophysical methods and on an assessment of the amount of uncertainty that is acceptable. Based on a preliminary assessment of these factors, the location of trench boundaries and detection of massive metallic objects are the important achievable objectives using current technology.

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

1991-11-01

160

Use of noninvasive geophysical techniques for the in situ vitrification program. Volume 3, Discussion and recommendations  

Energy Technology Data Exchange (ETDEWEB)

In situ vitrification (ISV) is a waste pit remediation technology that can potentially eliminate the need for pit excavation. The ISV program at the Idaho National Engineering Laboratory (INEL) funded this study to evaluate geophysical techniques that might be useful for performing detailed screening of the materials, soil conditions, and local geology of waste pits targeted for remediation. The evaluation focusses on a specific set of characterization objectives developed by ISV engineers. The objectives are based on their assessment of safety, environmental, and cost efficiency issues associated with the ISV process. A literature review of geophysical case histories was conducted and a geophysical survey was performed at the INEL simulated waste pit so that the evaluation could be based on demonstrable results. The literature review shows that all the ISV objectives are theoretically achievable because they involve physical properties (such as electrical conductivity, density, or magnetization) that can be sensed by geophysical instruments. However, most of the ISV objectives require substantially higher resolution than is achieved in typical waste site investigations, or than has been demonstrated by researches using state-of-the-art techniques. The survey at the INEL simulated waste pit yielded useful, qualitative information on subsurface materials and boundaries; but quantitative information, such as depth, size, or composition of buried materials, was subject to significant uncertainty. For ISV, the usefulness of geophysical characterization depends both on the capabilities of geophysical methods and on an assessment of the amount of uncertainty that is acceptable. Based on a preliminary assessment of these factors, the location of trench boundaries and detection of massive metallic objects are the important achievable objectives using current technology.

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

1991-11-01

 
 
 
 
161

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 64.3...

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

2008-01-01

162

Fabrication of Cu-sheathed MgB2 wire with high Jc-B performance using a mixture of in situ and ex situ PIT techniques  

International Nuclear Information System (INIS)

This work investigated methods of fabricating Cu-sheathed MgB2 wire, and succeeded in producing samples with enhanced Jc-B performance. Initially, MgB2/Cu wires were fabricated using either insitu or ex situ routes of the powder in tube (PIT) technique. The Jc-B performance of insitu MgB2/Cu wire is better (especially at lower magnetic fields) than that of the ex situ MgB2/Cu wire. However, the absolute Jc value was not particularly high (Jc at 6 T ? 3.4 x 102 A/cm2-4.2 K). As the next step, we tried to fabricate MgB2/Cu wire by the double core method, which enabled us to obtain wire in which the outer and inner cores correspond to ex situ and insitu wires, respectively. In this case, the Jc-B performance is drastically enhanced and the Jc at 6 T was 3.5 times higher (?1.2 x 103 A/cm2) than that of simple insitu MgB2/Cu wire. The double core method does not require special expensive tools, and there are many possibilities for future improvements in the wire. Therefore, we believe that this double core MgB2/Cu wire has a strong potential for the industrial fabrication of MgB2 wire with in-demand sheath materials such as Cu or Al.

2009-10-15

163

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

164

Transient stability of large scale system using efficient network reduction technique  

Energy Technology Data Exchange (ETDEWEB)

An efficient yet very simple technique incorporating Brown's axis discarding technique and optimal ordering of nodes for reducing a large scale power system has been described and its use in obtaining rapid transient stability solutions has been explained. The technique developed can also be used in short circuit analysis of a large power system when one is interested in finding out short circuit levels at a few buses in the system. 5 refs.

Shenoy, D.L.; Belapurkar, R.K.; Raghavan, R.; Nanda, J.; Kothari, D.P.

1981-12-01

165

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

166

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

Scientific Electronic Library Online (English)

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

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

167

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

Directory of Open Access Journals (Sweden)

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

Besharati Maghsoud

2008-01-01

168

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

169

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

International Nuclear Information System (INIS)

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

2014-02-01

170

In situ TEM study of stability of TaRhx diffusion barriers using a novel sample preparation method.  

Science.gov (United States)

The atomic diffusion mechanisms associated with metallurgical failure of TaRhx diffusion barriers for Cu metallizations were studied by in situ transmission electron microscopy (TEM). The issues related to in situ heating of focused ion beam (FIB) prepared cross-sectional TEM samples that contain Cu thin films are discussed. The Cu layer in Si/(13 nm)TaRhx/Cu stacks showed grain growth and formation of voids at temperatures exceeding 550°C. For Si/(43 nm)TaRhx/Cu stacks, grain growth of Cu was delayed to higher temperatures, i.e., 700°C, and void formation was not observed. Extensive surface diffusion of Cu, however, preceded bulk diffusion. Therefore, a 10 nm film of electron beam evaporated C was deposited on both sides of the TEM lamellae to limit surface diffusion. This processing technique allowed for direct observation of atomic diffusion and reaction mechanisms across the TaRhx interface. Failure occurred by nucleation of orthorhombic RhSi particles at the Si/TaRhx interface. Subsequently, the barrier at areas adjacent to RhSi particles was depleted in Rh. This created lower density areas in the barrier, which facilitated diffusion of Cu to the Si substrate to form Cu3Si. The morphology of an in situ annealed lamella was compared with an ex situ bulk annealed sample, which showed similar reaction morphology. The sample preparation method developed in this study successfully prevented surface diffusion/delamination of the Cu layer and can be employed to understand the metallurgical failure of other potential diffusion barriers. PMID:24296039

Dalili, Neda; Li, Peng; Kupsta, Martin; Liu, Qi; Ivey, Douglas G

2014-03-01

171

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 X...

Mansor Bin Ahmad; Yadollah Gharayebi; Mohd Sapuan Salit; Mohd Zobir Hussein; Kamyar Shameli

2011-01-01

172

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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). T...

Ahmad, Mansor Bin; Gharayebi, Yadollah; Salit, Mohd Sapuan; Hussein, Mohd Zobir; Shameli, Kamyar

2011-01-01

173

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2012-01-01

174

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

Science.gov (United States)

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

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

1998-01-01

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

1990-06-01

176

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

177

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2000-11-01

178

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 15%CP.

Virote PATTARAJINDA

2005-01-01

179

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

180

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

 
 
 
 
181

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

1982-01-01

182

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

Science.gov (United States)

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

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

2009-05-15

183

In situ bioremediation technique for sites underlain by silt and clay  

Energy Technology Data Exchange (ETDEWEB)

An in situ trickling filter system, named Trickling Trench, is being used to treat biodegradable organic compounds at a site underlain by silt and clay. This method provides the containment advantages of pump-and-treat remediation with the low-cost benefits of in situ bioremediation. A design method is presented using a conventional trickling filter analytical model with kinetic coefficients for various organic compounds calculated from published data. Performance monitoring data obtained from the Trickling Trench bioreactor are compared to design predictions.

Thacker, B.K.; Ford, C.G.

1999-12-01

184

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

Science.gov (United States)

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. PMID:24856176

Alasepp, Kadri; Borch, Kim; Cruys-Bagger, Nicolaj; Badino, Silke; Jensen, Kenneth; Sørensen, Trine H; Windahl, Michael S; Westh, Peter

2014-06-24

185

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2009-01-01

186

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

187

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

2006-11-12

188

In-situ analysis of minerals by means of neutron capture techniques  

International Nuclear Information System (INIS)

In the field of ore prospecting and exploration, neutron capture gamma-ray spectroscopy using isotopic neutron sources and Ge(Li) detectors provides a potent tool for in-situ analysis. The physical prerequisites as well as technical aspects of (n,?) applications are discussed in this paper. Experimental results of studies with marine ore concretions and sediments are given as examples. (Auth.)

1975-03-01

189

Stability of phase A in antigorite (serpentine) composition determined by in situ X-ray pressure observations  

Science.gov (United States)

Here, we precisely determined the low-pressure stability limit of phase A in the Mg-end-member antigorite bulk composition defined as the reaction forsterite + water = phase A + enstatite ("water-line" or "water-storage line") in a multi-anvil apparatus. Pressures were determined by in situ synchrotron X-ray diffraction measurements using NaCl as an internal pressure standard. Results demonstrate that the water-line is located at 800 °C and 8.5 GPa and at 550 °C and 5.1 GPa with a Clapeyron slope of 13.6 MPa/°C. We also examined the conditions for the formation of phase A by the decomposition of antigorite on the basis of the phase relations in the systems MgO-SiO 2-H 2O (MSH) and MgO-Al 2O 3-SiO 2-H 2O (MASH). A descending slab peridotite retains water in phase A beyond the stability of antigorite only when temperature in the slab is lower than 550 or 660 °C at 5.1 GPa (corresponding to 160 km depth), in the system MSH or MASH, respectively. The double seismic planes observed within the slabs may be caused by the dehydration reaction of antigorite or chlorite. Their merging depths, which could represent the high-pressure stability limit of antigorite or chlorite, are 160 km or deeper beneath northeast Japan, Aleutian, Kamchatka and Kuril. Water included in hydrous slab peridotite is transported into the transition zone and deeper mantle in these areas but recycled to the surface in other subduction zones.

Komabayashi, Tetsuya; Hirose, Kei; Funakoshi, Ken-ichi; Takafuji, Naoto

2005-08-01

190

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

Energy Technology Data Exchange (ETDEWEB)

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.

Hoffman, M.; Mai, Y.W. [Univ. of Sydney, New South Wales (Australia); Wakayama, Shuichi; Kawahara, Masanori [Tokyo Metropolitan Univ. (Japan). Dept. of Mechanical Engineering; Kishi, Teruo [Univ. of Tokyo (Japan)

1995-10-01

191

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

Directory of Open Access Journals (Sweden)

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

Humayun Kabir

2010-07-01

192

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

193

External tracheal stabilization technique for acquired tracheomalacia using a tailored silicone tube.  

Science.gov (United States)

Here, we describe an external tracheal stabilization technique used in a patient with tracheomalacia. A 56-year-old man presented with tracheomalacia due to prolonged mechanical ventilation. The malacic tracheal segment was approximately 2 cm in length. The malacic segment was covered with a silicone tube sutured in place using Prolene sutures (Ethicon, Somerville, NJ). Several anchoring sutures were placed between the tracheal mucosa and the silicone tube without violating the mucosal continuity. The patient was discharged on postoperative day 5 without complication. This method of external tracheal stabilization is a less invasive alternative for the management of this particular patient. PMID:23006701

Cho, Jong Ho; Kim, HoJoong; Kim, Jhingook

2012-10-01

194

A new computational technique for the stability analysis of slender rods  

Science.gov (United States)

A new computational technique for the stability analysis of slender rods with variable cross-sections under general loading conditions is presented. In this approach, the dependent variable and the variable coefficients appearing in the governing equations are expanded in a finite series of Chebyshev polynomials. The main feature of this technique is that the original boundary value problem associated with the differential equation is reduced to an algebraic eigenvalue problem. The proposed technique is applied to study the static buckling of Euler column and the flutter behavior of a cantilevel column subjected to uniformly distributed tangential loading. The numerical results from the suggested technique are found to be extremely accurate when compared to other techniques available in literature. It is shown that this approach can also be employed in a symbolic form. The merits of the present method in comparison to the standard solution procedures like finite difference and Galerkin methods are discussed.

Sinha, S. C.; Liu, Tai-Sheng; Senthilnathan, N. R.

1992-07-01

195

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

Science.gov (United States)

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

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

2014-05-01

196

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.

2008-01-01

197

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

198

Biological and biomechanical evaluation of bone remodelling and implant stability after using an osteotome technique.  

Science.gov (United States)

The influence of the osteotome technique on the osseointegration and biomechanical behaviour of cylinder implants (SLA, ITI was compared with conventional preparation of the implant site in an animal model. A total of 56 implants were placed in the cranial and caudal tibia condyle of six Gottinger minipigs. The implant site was prepared either by the conventional technique with drills (control group A) or by the osteotome technique (experimental group B). Resonance frequency measurements (RFMs) were made on each implant at the time of fixture placement and at the time of scarification. Half of the minipigs were sacrificed 7 days and 28 days after implant placement and the implants were removed with the surrounding bone. Bone tissue responses were evaluated by histological analysis and removal torque testing. For histological evaluation 30-50 microm-thick ground sections were examined. Biomechanical testing revealed a significantly higher stability of implants in the control group (A) than in the experimental group (B) (P = 0.004) at day 7. After 28 days implant stability in the control group remained significant higher (47%) than those of group B (P > 0.001). RFM demonstrated no significant difference between both groups and during the experimental course. Histological analysis demonstrated fractured trabeculae in peri-implant bone in the experimental group at day 7, while they were not posed at day 28. We conclude that the decreased implant stability by using the osteotome technique is based on microfractures in peri-implant bone. PMID:15642025

Büchter, André; Kleinheinz, Johannes; Wiesmann, Hans Peter; Kersken, Jan; Nienkemper, Manuel; Weyhrother, Hendrik von; Joos, Ulrich; Meyer, Ulrich

2005-02-01

199

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

200

Development of new ultrafiltration techniques maintaining in-situ hydrochemical conditions for colloidal study  

International Nuclear Information System (INIS)

Chemical state of elements in groundwater is one of the most important information for understanding behavior of elements in underground environment. Chemical state of elements controlled mainly by groundwater physico-chemical parameters. Because the change of physico-chemical parameters of groundwater, due to pressure release and oxidation during sampling, causes changes in chemical state of elements, systematic methodologies for understanding in situ chemical state is required. In this study, in order to understand chemical state of elements in groundwater, an ultrafiltration instrument for maintaining in-situ pressure and anaerobic conditions was developed. The instrument developed in this study for ultrafiltration made of passivated Stainless Used Steel (SUS) materials, was designed to keep groundwater samples maintaining in-situ pressure/anaerobic conditions. Ultrafiltration of groundwater was conducted at a borehole drilled from the 200 mbGL (meters below ground level) Sub-stage at a depth of 200 m at the Mizunami Underground Research Laboratory. Chemical analyses of groundwater were also conducted using samples filtered under both pressurized/anaerobic and atmospheric conditions and passivated SUS materials with different elapsed times after passivation. The results indicate that our ultrafiltration method is suitable for collection of filtered groundwater and passivation is an essential treatment before ultrafiltration. (author)

2010-10-03

 
 
 
 
201

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

Energy Technology Data Exchange (ETDEWEB)

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

Howard, D.; Lancaster, H.

1982-11-01

202

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

203

Feedback-stabilized interrogation technique for optical Fabry-Perot acoustic sensor using a tunable fiber laser  

Science.gov (United States)

This paper discusses a new stabilization technique used to measure acoustic signals over a large range of operating temperatures. The new stabilization technique is based on a diaphragm-based extrinsic Fabry-Perot interferometer (EFPI) acoustic sensor and feedback stabilization using a tunable fiber laser. The feedback stabilization technique is used to control the output wavelength of the tunable fiber laser to operate in the linear range of the diaphragm-based EFPI acoustic sensor. This method has no signal detection bandwidth limit, a high tuning speed, and a large tunable range. To verify the performance of the stabilization technique, we measured the output of the sensor by changing the environmental temperature, and the experimental results demonstrate that this system can stabilize the operating point of the sensor very well. An acoustic signal was successfully detected using a photoacoustic spectrometer system, and the fade-out problem was solved.

Wang, Qiaoyun; Ma, Zhenhe

2013-10-01

204

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

2007-12-17

205

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

Science.gov (United States)

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

Park, Hyuksang; Xu, Song; Seetharaman, Koushik

2011-05-01

206

Dynamic relaxation technique for determining the structure and stability of coronal magnetic fields  

International Nuclear Information System (INIS)

A new approach to the problem of determining the structure and stability of solar and stellar coronal magnetic fields is presented. It is pointed out that the conventional approach which proceeds by examining the linear stability of simple, analytic, but generally unrealistic equilibria fails to address many important questions - for example, the influence of finite-amplitude disturbances, the existence of multiple equilibria, or the possibility of perturbed boundary conditions. In contrast, the present paper invokes a Lagrange variable technique to formulate the problem dynamically as a mixed initial-value-boundary-value problem in three space dimensions. Thus, the determination of magnetic field structure is reduced to simulating the dynamic relaxation of an arbitrary initial magnetic field configuration toward equilibrium. The feasibility of the technique is illustrated by investigating straight but nonuniform twisted flux tubes as well as the typical twisted arch topology of coronal loops. 25 references

1986-01-01

207

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)

2012-12-01

208

Application Of Differential Pulse Cathodic Stripping Voltammetric Technique In Studying Stability Of Aflatoxins  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A stability studies of aflatoxins (AFB1, AFB2, AFG1 and AFG2 ) in Britton-Robinson buffer (BRb) using a Differential Pulse Cathodic Stripping Voltammetric (DPCSV) technique is described. The DPCSV was performed by cathodic potential scan through within the range of -950 to -1400 mV with 80s accumulation time using a BRb at pH 9.0 as the supporting electrolyte. The sampels were exposed for 0

Yaacob, Mohammad Hadzri; Yusoff, Abdull Rahim Hj Mohd; Ahamad, Rahmalan; Marpongahtun

2009-01-01

209

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

Scientific Electronic Library Online (English)

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

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

210

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

1987-01-01

211

A numerical technique for enhanced efficiency and stability for the solution of the nuclear reactor equation  

International Nuclear Information System (INIS)

The paper presents new techniques for the solution of the nuclear reactor equation in diffusion approximation, that has enhanced efficiency and stability. The code system based on the new technique solves a number of steady-state and/or transient problems with coupled thermal hydraulics in one-, two-, or three dimensional geometry with reduced CPU time as compared to similar code systems of previous generations if well-posed neutronics problems are considered. Automated detection of ill-posed problem and selection of the appropriate numerical method makes the new code system capable of yielding a correct solution for wider range of problems without user intervention. (author)

1996-09-08

212

Retargeting vesicular stomatitis virus glycoprotein pseudotyped lentiviral vectors with enhanced stability by in situ synthesized polymer shell.  

Science.gov (United States)

The ability to introduce transgenes with precise specificity to the desired target cells or tissues is key to a more facile application of genetic therapy. Here, we describe a novel method using nanotechnology to generate lentiviral vectors with altered recognition of host cell receptor specificity. Briefly, the infectivity of the vesicular stomatitis virus glycoprotein (VSV-G) pseudotyped lentiviral vectors was shielded by a thin polymer shell synthesized in situ onto the viral envelope, and new binding ability was conferred to the shielded virus by introducing acrylamide-tailored cyclic arginine-glycine-aspartic acid (cRGD) peptide to the polymer shell. We termed the resulting virus "targeting nanovirus." The targeting nanovirus had similar titer with VSV-G pseudotypes and specifically transduced Hela cells with high transduction efficiency. In addition, the encapsulation of the VSV-G pseudotyped lentivirus by the polymer shell did not change the pathway that VSV-G pseudotypes enter and fuse with cells, as well as later events such as reverse transcription and gene expression. Furthermore, the targeting nanovirus possessed enhanced stability in the presence of human serum, indicating protection of the virus by the polymer shell from human serum complement inactivation. This novel use of nanotechnology demonstrates proof of concept for an approach that could be more generally applied for redirecting viral vectors for laboratory and clinical purposes. PMID:23327104

Liang, Min; Yan, Ming; Lu, Yunfeng; Chen, Irvin S Y

2013-02-01

213

In-situ formation of silver nanoparticles stabilized by amphiphilic star-shaped copolymer and their catalytic application  

Science.gov (United States)

Silver nanoparticles (Ag NPs) were prepared via in situ reduction of silver nitrate (AgNO 3) using polymeric micelles as nanoreactors without any additional reductant. The micelles were constructed from the amphiphilic star-shaped copolymer composed of poly(?-caprolactone) (PCL) segment, 2-(dimethylamino)ethyl methacrylate (DMAEMA or DMA) units and oligo(ethylene glycol)monomethyl ether methacrylate (OEGMA or OEG) units. The Ag NPs stabilized by those star-shaped copolymers were characterized using UV-vis spectrum, DLS, TEM and FTIR. It confirmed that PDMAEMA exhibited the reducing property unless pH was above 7. The Ag NPs were sphere-like with a diameter of 10-20 nm, which was independent of the architecture of the copolymer and AgNO 3 concentration. Furthermore, the catalytic activity of these Ag NPs was investigated by monitoring the reduction of p-nitrophenol (4-NP) by NaBH 4. The result showed that the Ag NPs formed by coordination reduction can be effectively applied in catalytic reaction.

Huang, Xiujuan; Xiao, Yan; Zhang, Wei; Lang, Meidong

2012-01-01

214

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

CERN Multimedia

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

215

["In-situ split" (ISS) liver resection: new aspects of technique and indication].  

Science.gov (United States)

The combination of right portal vein ligation with complete parenchyma dissection ("in-situ split", ISS) for rapid hypertrophy induction of the left-lateral liver lobe is a novel strategy to convert primarily irresectable liver tumours into a resectable stage. Available data so far show a 60-80?% growth induction of the remnant liver within 7(-?9) days. Certainly, a novel concept that comprises two operations within a very short time period raises questions. Based on the very few literature reports that have been published so far, as well as our own experience, we here discuss technical issues such as the use of a plastic sheet on the resection margin, the possibility of laparoscopic dissection and the timing of the second operation. Moreover, aspects of the preoperative diagnostic work-up that is necessary are assessed. Finally, open questions, e.g., concerning the influence of preoperative chemotherapy and the use of ISS in patients with cirrhosis are evaluated. In summary, the assessment of chances and risks of this novel concept with regard to indication and technical issues helps to provide the potentially curative option of the "in-situ split" procedure to more patients with marginal or even irresectable liver tumours. PMID:24022245

Lang, S A; Loss, M; Schlitt, H J

2014-04-01

216

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

International Nuclear Information System (INIS)

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

2003-01-01

217

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

CERN Multimedia

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

218

Studies on In-situ Chelation/Supercritical Fluid Extraction of Lanthanides and Actinides Using a Radiotracer Technique  

Energy Technology Data Exchange (ETDEWEB)

Radioisotope tracer techniques were used to study the process of in-situ chelation/supercritical fluid extraction(SFE) of La3+ and Lu3+ from solid matrix using mixed ligand hexafluoroacetylacetone (HFA) and tributylphosphate (TBP) as chelating agents. A lab-built SFE extactor was used in this study and the extractor design was optimized based on the experimental results. Quantitative recovery of La and Lu was achieved when the extrator design was optimized. Extraction of uranium from real world samples was also investigated to demonstrate the capability of this chelation/SFE technology for environmental remediation applications. A novel on-line back extraction technique for the recovery of metal ions and regeneration of ligands is also reported.

Lin, Yuehe; Wu, Hong; Smart, Neil G.; Wai, Chien M.

2001-06-01

219

In situ particle size measurements using a two-color laser scattering technique  

Energy Technology Data Exchange (ETDEWEB)

We have developed a technique using light scattered from individual particles in the near-forward direction to measure particle size in the range of 10 to 200 microns. This technique uses the Mie scattering theory to relate the measured light intensity to particle size based on calibration techniques employing pinholes and water droplets of known size. We have applied a unique two-color optical arrangement to minimize the edge effect which can cause incorrect size measurements for particles that pass through the edge of the laser beam focal volume. In this paper we describe our experimental technique and the results of size measurements obtained with this technique for water droplets and pulverized coal particles.

Wang, J.C.F.; Hencken, K.R.

1992-02-01

220

In situ particle size measurements using a two-color laser scattering technique  

Energy Technology Data Exchange (ETDEWEB)

We have developed a technique using light scattered from individual particles in the near-forward direction to measure particle size in the range of 10-200 ..mu..m. This technique uses the Mie scattering theory to relate the measured light intensity to particle size based on calibration techniques employing pinholes and water droplets of known size. We have applied a unique two-color optical arrangement to minimize the edge effect which can cause incorrect size measurements for particles that pass through the edge of the laser beam focal volume. In this paper we describe our experimental technique and the results of size measurements obtained with this technique for water droplets and pulverized coal particles.

Wang, J.C.F.; Hencken, K.R.

1986-03-01

 
 
 
 
221

In situ particle size measurements using a two-color laser scattering technique  

International Nuclear Information System (INIS)

We have developed a technique using light scattered from individual particles in the near-forward direction to measure particle size in the range of 10-200 ?m. This technique uses the Mie scattering theory to relate the measured light intensity to particle size based on calibration techniques employing pinholes and water droplets of known size. We have applied a unique two-color optical arrangement to minimize the edge effect which can cause incorrect size measurements for particles that pass through the edge of the laser beam focal volume. In this paper we describe our experimental technique and the results of size measurements obtained with this technique for water droplets and pulverized coal particles

1986-03-01

222

Synthesis and characterization of hydroxyapatite/titania nanocomposites using in situ precipitation technique  

Science.gov (United States)

Hydroxyapatite/titania nanocomposites were successfully synthesized by in situ precipitation of precursor matters from hydroxyapatite and titania at 70 °C with different hydroxyapatite/titania ratios. X-ray diffraction, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller surface, scanning and transmission electron microscopes were employed to characterize the prepared nanocomposite powders. X-ray diffraction results indicated that hydroxyapatite and anatase (TiO2) were the major crystalline phases. By increasing the amount of titania nano-particles, Fourier transform infrared spectroscopy revealed that (PO4)3- bands at 567, 1033 cm-1 decreased. Brunauer-Emmett-Teller surface results also showed a reduction in surface areas of nanocomposites. Transmission electron microscope observations revealed that the aspect ratio of hydroxyapatite/TiO2 nanocrystals increased by increasing TiO2 proportion in nanocomposites. The observed nanorod crystals tended to thin, elongated and plate-like in shape.

Enayati-Jazi, Mahnaz; Solati-Hashjin, Mehran; Nemati, Ali; Bakhshi, Farhad

2012-06-01

223

An improved direct feedback linearization technique for transient stability enhancement and voltage regulation of power generators  

Energy Technology Data Exchange (ETDEWEB)

In this paper, a simple improved direct feedback linearization design method for transient stability and voltage regulation of power systems is discussed. Starting with the classical direct feedback linearization technique currently applied to power systems, an adaptive nonlinear excitation control of synchronous generators is proposed, which is new and effective for engineering. The power angle and mechanical power input are not assumed to be available. The proposed method is based on a standard third-order model of a synchronous generator which requires only information about the physical available measurements of angular speed, active electric power and generator terminal voltage. Experimental results of a practical power system show that fast response, robustness, damping, steady-state and transient stability as well as voltage regulation are all achieved satisfactorily. (author)

Kenne, Godpromesse [Laboratoire d' Automatique et d' Informatique Appliquee (LAIA), Departement de Genie Electrique, Universite de Dschang, B.P. 134 Bandjoun, Cameroun; Goma, Raphael; Lamnabhi-Lagarrigue, Francoise [Laboratoire des Signaux et Systemes (L2S), CNRS-SUPELEC, Universite Paris XI, 3 Rue Joliot Curie, 91192 Gif-sur-Yvette (France); Nkwawo, Homere [Departement GEII, Universite Paris XIII, IUT Villetaneuse, 99 Avenue Jean Baptiste Clement, 93430 Villetaneuse (France); Arzande, Amir; Vannier, Jean Claude [Departement Energie, Ecole Superieure d' Electricite-SUPELEC, 3 Rue Joliot Curie, 91192 Gif-sur-Yvette (France)

2010-09-15

224

A novel technique for ventral orbital stabilization: the masseter muscle flap.  

Science.gov (United States)

Loss of the caudal maxilla and ventral orbit after tumor resections can have negative functional and esthetic influences on the eye involved. This article reports on a case of a caudal maxillary acanthomatous ameloblastoma involving the ventral orbit that was resected and stabilized with a masseter muscle flap. The masseter muscle flap was generated from the superficial belly of the masseter muscle in order to close a defect in the orbital rim, created by a caudal maxillectomy. None of the published complications such as enophthalmos, excessive lacrimation, globe deviation, or strabismus were noted, 8 months following the procedure. The only clinical sign present at the time of re-evaluation was mild lacrimation. The authors propose the use of a masseter muscle flap as a viable technique in stabilizing the ventral orbit after caudal maxillectomy and ventral orbitectomy, preventing the complications associated with this surgery. PMID:23710820

Sivagurunathan, Amilan; Boy, Sonja C; Steenkamp, Gerhard

2014-01-01

225

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

International Nuclear Information System (INIS)

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

2002-02-11

226

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)

2013-07-01

227

Integrating satellite, airborne, and in situ observations to assess the stability of the Larsen C Ice Shelf, Antarctica  

Science.gov (United States)

The collapse of the Larsen A and B ice shelves has been attributed to meltwater driven crevasse propagation, rendering the ice shelf into numerous, elongate icebergs which rapidly overturned during the final disintegration. The rapid nature of this style of disintegration overshadows the role structural features, such as crevasses and rifts, and processes, such as thinning and firn densification, play in 'pre-conditioning' the ice shelf in the years and decades preceding these events, whereby making it increasingly susceptible to collapse. We assess the stability of the Larsen C ice shelf, which, at ~50,000 km2, is the largest remaining ice shelf on the Antarctic Peninsula (AP). We examine, in detail, three specific structural features of the ice shelf: marine ice, basal crevasses, and ice rises, through the integration of historic defense, moderate and high-resolution satellite imagery, NASA IceBridge airborne altimetry, and in situ ground penetrating radar (GPR). In particular, (1) we examine the termination of rift tips along coherent flow domains, assumed to be of marine provenance, and assess the properties of these domains with GPR, (2) highlight the prevalence of basal crevasses across the ice shelf, and consider how these features, by inducing both surface crevassing and depressions, may play an important role in hydrofracture, and (3) assess the two primary ice rises, the Bawden and Gipps, and their role in past and potentially future calving events. Lastly, we calculate current grounding line ice fluxes delineated by ice shelf domain, and compare this flux to the total ice volume within each domain, thereby calculating a "replacement time." We consider, based on observed grounding line flux increases following the collapse of Larsen B, the potential future contribution to sea level rise if the Larsen C ice shelf were to collapse.

McGrath, D.; Steffen, K.; Scambos, T. A.; Rajaram, H.; Rignot, E. J.; Abdalati, W.

2012-12-01

228

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

Science.gov (United States)

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

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

2009-12-01

229

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

230

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

231

'Ballistic damping' - a possible technique for stabilizing resonant ion cyclotron modes in mirror systems  

International Nuclear Information System (INIS)

A technique called ''ballistic damping'' is proposed for the control of ion cyclotron instabilities of the highly coherent type characteristically observed in mirror-confined plasmas at high plasma density. Ion beams, launched parallel to the field lines, transit the plasma resonantly gaining perpendicular energy from the unstable wave. These ions exit through the far mirror, thereby extracting energy from the wave. Critical beam currents required to achieve marginal stability, as estimated from power balance considerations, lie well within existing beam technology, both for present mirror or tandem mirror experiments and for scaled-up systems. (author)

1982-01-01

232

Stabilization of ?-Be at room temperature by a rapid quench technique  

International Nuclear Information System (INIS)

The retention of the ?-Be phase at room temperature by the use of a rapid quench technique opens the way for a full investigation of its physical properties. Studied were thermal response, hardness, electrical resistivity, structural analysis, and superconductivity. Preliminary work indicates that the stabilization of the ?-Be structure at room temperature is a very sensitive function of Ni content. This sensitivity is illustrated by the fact that the Be_9_2Ni_8 sample is mainly ?-phase while the Be_9_1 _8Ni_8 _2 is almost completely ?-phase. Retention of the ?-structure apparently requires the exact eutectoid composition and a high quench rate

1980-01-01

233

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

Science.gov (United States)

Posterior shoulder instability is far less common than anterior instability, and its arthroscopic treatment can be technically demanding. We describe a percutaneous arthroscopic technique for posterior shoulder stabilization using mattress sutures and knotless anchors. Spinal needles are used to pass the sutures percutaneously in a mattress fashion. Knotless anchors are used to secure the sutures under the labrum. These anchors can be used without cannulas, giving easier access to the posterior glenoid. This procedure is simple, cost-effective, and safe, avoiding the presence of both knots and suture strands in contact with the humeral head.

Tennent, Duncan; Concina, Chiara; Pearse, Eyiyemi

2014-01-01

234

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

Science.gov (United States)

Posterior shoulder instability is far less common than anterior instability, and its arthroscopic treatment can be technically demanding. We describe a percutaneous arthroscopic technique for posterior shoulder stabilization using mattress sutures and knotless anchors. Spinal needles are used to pass the sutures percutaneously in a mattress fashion. Knotless anchors are used to secure the sutures under the labrum. These anchors can be used without cannulas, giving easier access to the posterior glenoid. This procedure is simple, cost-effective, and safe, avoiding the presence of both knots and suture strands in contact with the humeral head. PMID:24749039

Tennent, Duncan; Concina, Chiara; Pearse, Eyiyemi

2014-02-01

235

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

International Nuclear Information System (INIS)

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

2013-09-01

236

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

237

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

238

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

239

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)

1991-01-01

240

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

1980-01-01

 
 
 
 
241

In situ method of inspecting anchor rods for section loss using the cylindrically guided wave technique  

Energy Technology Data Exchange (ETDEWEB)

A nondestructive evaluation technique has been developed to measure and analyze section loss due to corrosion for anchor rods used in guying steel transmission poles. The anchor guy system tested consists of a steel plate embedded in concrete connected to a steel rod buried in earth and attached to the guy wire from the pole. The method used was ultrasonics and specifically, the cylindrically guided wave technique (CGWT). Field correlation of the method was verified by digging up and inspecting several rods. This approach has optimized the ultimate replacement and maintenance expense.

Niles, G.B. [Baltimore Gas and Electric Co., MD (United States)

1996-07-01

242

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)

2005-12-01

243

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

Directory of Open Access Journals (Sweden)

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

Somayeh Bakhshizadeh

2014-04-01

244

A direct in situ fingerprinting method for acid rock drainage using voltammetric techniques with a single renewable gold microelectrode.  

Science.gov (United States)

Electrochemistry allows for rapid identification of multiple metals and other chemical complexes common in acid rock drainage (ARD) systems. Voltammetric scans using a single gold microelectrode of water samples from geochemically distinct areas of the Río Tinto (RT) in southwestern Spain were clearly recognizable in the field and in samples stored at room temperature for over 6 months. Major voltammetric peaks of iron(III) and copper(II) were identified on a single constantly renewable gold microelectrode. Confirmation of these peaks was performed by spiking with standard metal solutions in the laboratory. This voltammetric technique is a rapid, direct and inexpensive in situ method for identification of water sources and their chemical characteristics, as well as an economical way to monitor environmental changes and remediation efforts. PMID:21354595

Nuzzio, Donald B; Zettler, Erik R; Aguilera, Angeles; Amaral-Zettler, Linda A

2011-04-15

245

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

Directory of Open Access Journals (Sweden)

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

Macanás Jorge

2011-01-01

246

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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: T...

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

2011-01-01

247

The practical use of the technique of choosing an optimal value-set of qualitative attributes: the problem of stability  

International Nuclear Information System (INIS)

The practical use of the technique of choosing optimal sets of significances of qualitative attributes is discussed. One of the aspects of the practical use of any technique is the problem of its stability. The stability of the technique, the top and bottom valuations of the degree of fuzziness, of losses of information and of noise is considered. It is shown that the technique is stable with respect to small changes of the initial data. This permits to assert that its use in practical tasks is possible

1994-09-14

248

Hydrogen permeability technique in situ reactor irradiation for ITER structural materials  

International Nuclear Information System (INIS)

This work develops the technique of hydrogen diffusion parameters measurements in metal materials during the process of reactor irradiation. The possibility of irradiation stimulated hydrogen diffusion for 08Cr18Ni10Ti was obtained. Constants of diffusion, permeation and solution while the process of irradiation were measured as a result of the work. Formally calculated activation energies of diffusion and permeation were obtained to decrease while the solution heat was increasing. 5 refs., 4 figs., 1 tab

1995-10-01

249

Hydrogen permeability technique in situ reactor irradiation for ITER structural materials  

Energy Technology Data Exchange (ETDEWEB)

This work develops the technique of hydrogen diffusion parameters measurements in metal materials during the process of reactor irradiation. The possibility of irradiation stimulated hydrogen diffusion for 08Cr18Ni10Ti was obtained. Constants of diffusion, permeation and solution while the process of irradiation were measured as a result of the work. Formally calculated activation energies of diffusion and permeation were obtained to decrease while the solution heat was increasing. 5 refs., 4 figs., 1 tab.

Tazhibaeva, I.L.; Shestakov, V.P.; Chikhray, E.V.; Romanenko, O.G.; Klepikov, A.K. [National Univ. of Kazakhastan, Almaty (Kazakhstan); Cherepnin, Y.S.; Kenzhin, E.A.; Basov, A.A.; Kolodeshnikov, A.A. [National Nuclear Center of Kazakhstan, Krasnoarmeyskaya (Kazakhstan)

1995-10-01

250

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

251

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 < 0.01). A quadratic response (P ? 0.06) for TTIDP was observed in smooth bromegrass and 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

252

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)

2002-07-07

253

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

254

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

255

The importance of in-situ-stress profiles in hydraulic-fracturing applications  

Energy Technology Data Exchange (ETDEWEB)

In-situ stresses define the local forces acting on lithologic layers in the subsurface. Knowledge of these stresses is important in drilling, wellbore-stability, and, especially, hydraulic-fracturing applications. The measurement of in-situ stress is not straightforward and, therefore, often goes unmeasured. As such, one often assumes values of in-situ stress or estimate in-situ stresses from logging parameters. This article illustrates the importance of in-situ-stress estimates as they relate to hydraulic fracturing and outlines several techniques for estimating in-situ-stress magnitudes.

Hopkins, C.W. [S.A. Holditch and Associates, Inc., Houston, TX (United States). Houston Div.

1997-09-01

256

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

257

Wheat improvement for drought resistance and yield stability using mutation techniques  

International Nuclear Information System (INIS)

The main problem of plant breeding is development of varieties with optimal combination of high drought resistance, productivity and yield stability in varying unfavorable conditions. It is especially important for Kazakhstan, the main agricultural areas of which are located in the arid zones characterized by moisture supply deficiency. Mutation techniques have proven to be valuable technique in enhancing crop genetic diversity for selecting new variants with traits of economic importance. Therefore we used M2 population of spring bread wheat var. Kazakhstastanskaya 126 treated by nicotinic acid extracted from tobacco leaves 0,01% and 0,1%, respectively. Based on germplasm of M2 there was developed genotype Grekum 476 having changes in leaf shape such as rolling of flag leaf. This trait protects plant from intensive insolation and overheating, prevent losses of water and provide long-term function of leaves and therefore it was used for wheat improvement of commercial cultivars. The objective of this study is the analysis of genotype x environment interaction (GEI) and evaluation of the donors of drought resistance and stability among the winter wheat genotypes. Experimental material has been grown in 2004-2006 at thee contrasting ecological zones including irrigated and non-irrigated conditions. To analyze GEI the method Tai (1971) was used. Drought susceptibility index was used for drought resistance assessment (Fisher and Maurer, 1978). The 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)

2008-08-12

258

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

259

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

260

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

2006-03-01

 
 
 
 
261

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

262

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

Science.gov (United States)

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

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

2012-11-01

263

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

Directory of Open Access Journals (Sweden)

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

W. Reid

2012-11-01

264

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

International Nuclear Information System (INIS)

Super Critical Water Oxidation (SCWO) is a promising technology for destroying highly toxic organic waste (including physiological agents) and for reducing the volume of DOE's low-level nuclear waste. The major problem inhibiting the wide implementation of SCWO is the lack of fundamental knowledge about various physico-chemical and corrosion processes that occur in SCW environments. In particular, the lack of experimental techniques for accurately monitoring important parameters, such as pH, corrosion potential and corrosion rate, has severely hampered the development of a quantitative understanding of the degradation of materials in this extraordinarily aggressive environment. Accordingly, the principal objective of the present program has been to develop new, innovative methods for accurately measuring parameters that characterize corrosion processes under super critical conditions

2000-01-01

265

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

Energy Technology Data Exchange (ETDEWEB)

Super Critical Water Oxidation (SCWO) is a promising technology for destroying highly toxic organic waste (including physiological agents) and for reducing the volume of DOE's low-level nuclear waste. The major problem inhibiting the wide implementation of SCWO is the lack of fundamental knowledge about various physico-chemical and corrosion processes that occur in SCW environments. In particular, the lack of experimental techniques for accurately monitoring important parameters, such as pH, corrosion potential and corrosion rate, has severely hampered the development of a quantitative understanding of the degradation of materials in this extraordinarily aggressive environment. Accordingly, the principal objective of the present program has been to develop new, innovative methods for accurately measuring parameters that characterize corrosion processes under super critical conditions.

Macdonald, D.D.

2000-06-01

266

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

International Nuclear Information System (INIS)

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

1994-08-01

267

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

International Nuclear Information System (INIS)

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

2014-03-01

268

Primary stability of tibial components in TKA: in vitro comparison of two cementing techniques.  

Science.gov (United States)

In spite of improvements in cementing technique, migration of tibial component remains a problem in total knee arthroplasty. This study compares the primary stability of tibial components using two different cementing techniques with roentgen stereophotogrammetric analysis (RSA) in vitro. A total of 20 tibia specimens were matched into two groups, 10 specimens per group. Cementing technique was randomized to each group. In the first group only the base and in the second group the base and stem were cemented. The implants and the tibial metaphysis were marked with markers for the RSA analysis. All specimens were tested with an axial load of 2,000 N for 1,000 and 10,000 cycles and RSA analysis was performed. Endpoints for radiosterometric analysis were maximum total point motion, maximum subsidence, lift off, rotation and translation along the x-, y-, and z-axes. After 1,000 and 10,000 cycles, no significant differences could be found, but two tibial components of the surface cementing group showed a migration of more than 2 mm defined as failure compared to six failed tibial components in the full cementing group (P = 0.068). This higher number of failed arthroplasties in the fully cemented prosthesis group demonstrates a disadvantageous load distribution in the tibia apophysis which can cause an early component loosening. PMID:19572121

Skwara, Adrian; Figiel, J; Knott, T; Paletta, J R J; Fuchs-Winkelmann, S; Tibesku, C O

2009-10-01

269

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

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

In-situ measurements of dynamic irradiation effects using optical techniques  

International Nuclear Information System (INIS)

The feasibility of applying optical fibers to the in-core measurement in nuclear reactors was examined by using the material testing reactor JMTR in Japan Atomic Energy Research Institute. For the research on the development of the materials and fuel with excellent radiation resistance, it is necessary to develop the system which measures irradiation effect in nuclear reactors on real time, and optical measurement is the most desirable technique. Regarding optical fibers, it has been made clear according to the experience in the past that the transmission characteristics deteriorate remarkably due to irradiation as color centers are introduced in large quantity into the fiber core due to the ionization effect of radiation. The use of optical fibers in intense radiation fields and the behavior of optical fibers in nuclear reactors are reported. The radiation-resistant fibers which were developed showed the very good transmission characteristics in the long wavelength region exceeding 750 nm. In short wavelength region, the characteristics in visible region were worsened remarkably by large absorption. (K.I.)

1995-03-01

272

In situ monitoring of zinc phosphate coating formation on mild steel by acoustic emission technique  

Science.gov (United States)

In the present work, an acoustic emission (AE) technique, along with potential electrode measurements, is used to study the zinc phosphate coating formation obtained on mild steel by cathodic electrochemical treatment (-15 mA cm-2) at ambient temperature. The AE activity recorded during the phosphate coating formation shows evident links between this activity and the coating parameters such as the potential electrode and coating weight. The principal component analysis (PCA) of AE parameters reveals the presence of three well-separated populations denoted A, B and C. These populations (A, B and C) show peak frequencies <180 kHz, between 214 and 260 kHz, and 280 and 320 kHz, respectively. The energy of the B and C populations is lower than that of A population and the rise time of B population is much longer than that recorded for the populations A and C. These events were respectively attributed to the evolution and release of dihydrogen bubbles, the formation and growth of the phosphate layer, and the stress release generated by the dihydrogen bubbles trapped in the coating pores.

Simescu, Florica; Idrissi, Hassane

2009-05-01

273

In situ monitoring of zinc phosphate coating formation on mild steel by acoustic emission technique  

International Nuclear Information System (INIS)

In the present work, an acoustic emission (AE) technique, along with potential electrode measurements, is used to study the zinc phosphate coating formation obtained on mild steel by cathodic electrochemical treatment (?15 mA cm?2) at ambient temperature. The AE activity recorded during the phosphate coating formation shows evident links between this activity and the coating parameters such as the potential electrode and coating weight. The principal component analysis (PCA) of AE parameters reveals the presence of three well-separated populations denoted A, B and C. These populations (A, B and C) show peak frequencies <180 kHz, between 214 and 260 kHz, and 280 and 320 kHz, respectively. The energy of the B and C populations is lower than that of A population and the rise time of B population is much longer than that recorded for the populations A and C. These events were respectively attributed to the evolution and release of dihydrogen bubbles, the formation and growth of the phosphate layer, and the stress release generated by the dihydrogen bubbles trapped in the coating pores

2009-05-01

274

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)

2002-01-01

275

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

276

Technique for evaluation of seismic stability of the NPP main building with WWER-440 reactor  

Energy Technology Data Exchange (ETDEWEB)

Technique for evaluation of seismic stability of the main NPP building with WWER-440 reactor is described; the building has been simulated as a spatial discrete linear-elastic system with 61 degrees of freedom. A formula for determination of the vector of inertial seismic loads is given. The calculation was made according to the TRAZLIST program. The calculation accounts for a large number of intrinsic forms of the building structure vibrations. Low intrinsic forms of vibrations of bulding structures are of rather low-frequency (the first natural frequency is 0.56 Hz and the first ten frequencies are in the 0-2 Hz range). Strength calculation of building structures conducted on the base of determined seismic loadings has revealed a necessity of their reinforcement.

Birbraer, A.N.; Rubinshtejn, M.V.; Shul' man, S.G.

1984-03-01

277

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

278

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.

2007-01-01

279

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

280

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

International Nuclear Information System (INIS)

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

2012-01-01

 
 
 
 
281

Technology evaluation report: International Waste Technologies/Geo-Con in-situ stabilization/solidification. Volume 4. Update report. Final report, April 1988-January 1990  

Energy Technology Data Exchange (ETDEWEB)

The long-term performance tests provide information on the first follow-up sampling and analysis on the SITE program demonstration of the International Waste Technologies additive, and the Geo-Con deep soil mixing equipment. The samples containing PCBs, were collected one year after the demonstration, and the chemical and physical test results were compared to those obtained during the demonstration. This was the first part of a 5-year monitoring program on this in-situ stabilization/solidification process. The demonstration was performed in April 1988 at an electric service shop in Hialeah, FL. Volume 4 contains the technical operating data--logs, laboratory analyses, and microstructural analyses.

Sawyer, S.

1990-09-01

282

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

283

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

284

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

Directory of Open Access Journals (Sweden)

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

Djadoun S.

2012-08-01

285

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

286

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...

2011-01-01

287

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

Science.gov (United States)

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

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

2013-03-01

288

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

Directory of Open Access Journals (Sweden)

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

W. Reid

2013-03-01

289

In-situ surface technique analyses and ex-situ characterization of Si1-xGex epilayers grown on Si(001)-2 ×1 by molecular beam epitaxy  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Si1-xGex epilayers grown by Molecular Beam Epitaxy on Si(001) at 400 ?C have been analyzed in-situ by surface techniques such as X-ray and Ultraviolet Photoelectron Spectroscopies (XPS and UPS), Low Energy Electron Diffraction (LEED) and photoelectron diffraction (XPD). The Ge surface concentrations (x) obtained from the ratios of Ge and Si core level intensities are systematically higher than those obtained by the respective evaporation fluxes. This indicates a Ge enrichment in the first o...

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

1994-01-01

290

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

291

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

Science.gov (United States)

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.

Sankar, Gopinathan; Fiddy, Steven; Beale, Andrew M.; Harvey, Ian; Hayama, Shusaku; Bushnell-Wye, Graham

2007-02-01

292

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

293

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

International Nuclear Information System (INIS)

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

1981-01-01

294

A Novel Method for in Situ Detection of Hydrolyzable Casein Fragments in a Cheese Matrix by Antibody Phage Display Technique and CLSM  

DEFF Research Database (Denmark)

A novel method to monitor in situ hydrolyzable casein fragments during cheese ripening by using immunofluorescent labeling and confocal laser scanning microscopy (CLSM) was developed. Monoclonal single chain variable fragments of antibody (scFvs) were generated by antibody phage display toward three small synthetic peptides of the αs1-casein sequence. These peptides traverse enzymatic cleavage sites of casein during cheese ripening. The specificity of the generated anti-peptide antibodies was determined by ELISA and Western blot. Finally, an immunofluorescent labeling protocol was successfully developed for the detection of scFvs binding to different αs1-casein fragments inside a cheese matrix by CLSM. To our knowledge, this is the first demonstrated immunofluorescent labeling method for in situ analysis of proteolysis phenomena in the cheese matrix. Additionally, this technique offers a high potential to study in situ dynamic spatial changes of target components in complex food systems.

Duan, Zhi; BruÌ?ggemann, Dagmar Adeline

2009-01-01

295

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

Energy Technology Data Exchange (ETDEWEB)

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

Morin, Pierre, E-mail: pierre.morin@st.com [STMicroelectronics, 850 rue Jean Monet, 38926 Crolles Cedex (France); Raymond, Gaetan; Benoit, Daniel; Maury, Patrick; Beneyton, Remi [STMicroelectronics, 850 rue Jean Monet, 38926 Crolles Cedex (France)

2012-11-01

296

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

International Nuclear Information System (INIS)

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

2012-11-01

297

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

298

In-situ measurement of the stress-induced phase transformations in magnesia-partially-stabilized zirconia using Raman spectroscopy  

International Nuclear Information System (INIS)

This paper reports on Raman spectroscopy that has been used to examine the connection between room-temperature creep and stress-induced phase transformations in TS-grade Mg-PSZ. The in-situ phase measurements obtained show that the tetragonal phase transforms to both the orthorhombic and monoclinic structures under stress. The effect of precipitate orientation is indicated by the variation of creep strain with monoclinic volume fraction

1992-06-01

299

In-situ measurement of the stress-induced phase transformations in magnesia-partially-stabilized zirconia using Raman spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

This paper reports on Raman spectroscopy that has been used to examine the connection between room-temperature creep and stress-induced phase transformations in TS-grade Mg-PSZ. The in-situ phase measurements obtained show that the tetragonal phase transforms to both the orthorhombic and monoclinic structures under stress. The effect of precipitate orientation is indicated by the variation of creep strain with monoclinic volume fraction.

Lim, C.S.; Finlayson, T.R.; Ninio, F.; Griffiths, J.R. (Physics Dept. and Dept. of Materials Engineering, Monash Univ., Clayton, Victoria 3168 (AU))

1992-06-01

300

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

Energy Technology Data Exchange (ETDEWEB)

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.

Jiang, Ling, E-mail: lingjiang616@hotmail.com [College of Information Science and Technology, Nanjing Forestry University, 159 Longpan Road, Nanjing 210037 (China); Li, Chun, E-mail: 419726258@qq.com [College of Information Science and Technology, Nanjing Forestry University, 159 Longpan Road, Nanjing 210037 (China); Shiino, Tatsuya, E-mail: shiino@taurus.phys.s.u-tokyo.ac.jp [Department of Physics, The University of Tokyo, Hongo 7-3-1, Tokyo 113-0033 (Japan); Yamamoto, Satoshi, E-mail: yamamoto@taurus.phys.s.u-tokyo.ac.jp [Department of Physics, The University of Tokyo, Hongo 7-3-1, Tokyo 113-0033 (Japan)

2013-02-14

 
 
 
 
301

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

2013-02-14

302

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

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

303

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

304

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

2013-01-01

305

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

306

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

International Nuclear Information System (INIS)

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

2012-04-15

307

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-07-01

308

Technology evaluation report: International Waste Technologies/Geo-Con in-situ stabilization/solidification. Volume 3. Update report. Final report, April 1988-January 1990  

Energy Technology Data Exchange (ETDEWEB)

The long-term performance tests provide information on the first follow-up sampling and analysis on the SITE program demonstration of the International Waste Technologies additive, and the Geo-Con deep soil mixing equipment. The samples containing PCBs, were collected one year after the demonstration, and the chemical and physical test results were compared to those obtained during the demonstration. This was the first part of a 5-year monitoring program on this in-situ stabilization/solidification process. The demonstration was performed in April 1988 at an electric service shop in Hialeah, FL. Volume 3 discusses the results of the long-term monitoring tests and how they compare to the results of the demonstration.

Sawyer, S.

1990-09-01

309

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

International Nuclear Information System (INIS)

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

1988-01-01

310

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

311

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

International Nuclear Information System (INIS)

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

2012-09-01

312

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

Science.gov (United States)

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

Xia, Dengning; Gan, Yong; Cui, Fude

2014-01-01

313

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.

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

314

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

315

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

316

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

317

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

International Nuclear Information System (INIS)

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

1985-08-01

318

IN-SITU XRD STUDIES OF THERMAL STABILITY OF PURE SILICA AND Ti-MCM-41 MATERIALS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this work we present a study on the thermal stability of siliceous and titanium containing ordered mesoporous materials with MCM-41 structure, prepared by direct synthesis at ambient temperature and pressure, as previously described [1]. Grades with different pore diameter and Si/Ti molar ratios were analyzed, in the form of compacted powder, to assess its influence on the order-disorder transition temperature.

Franco, Nuno; Alves, Eduardo; Galacho, Cristina; Carrott, Manuela; Carrott, Peter

2007-01-01

319

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Oliczewski, Susen; Daniels, Rolf

2007-01-01

320

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

 
 
 
 
321

Preparation of raspberry-like polymer particles by a heterocoagulation technique utilizing hydrogen bonding interactions between steric stabilizers.  

Science.gov (United States)

Large polystyrene particles stabilized by poly(acrylic acid) (PAA) (L-PS(PAA)) (as the core) and small polystyrene particles stabilized by poly(vinyl pyrrolidone) (PVP) (S-PS(PVP)) (as the corona) were successfully used to prepare raspberry-like particles by a heterocoagulation technique utilizing the hydrogen bonding interaction between PAA and PVP. The coverage of L-PS(PAA) by S-PS(PVP) could be controlled by adding PVP homopolymer to the L-PS(PAA) dispersion and by changing the molecular weight of the stabilizers. Moreover, the heterocoagulation of large poly(methyl methacrylate) particles stabilized by PAA (L-PMMA(PAA)) and S-PS(PVP) particles was also accomplished, resulting in the formation of L-PMMA(PAA)-core/S-PS(PVP)-corona raspberry-like composite particles. These results suggested that the raspberry-like particles composed of various polymer particles could be formed by the heterocoagulation technique utilizing the hydrogen bonding interaction. PMID:23244162

Minami, Hideto; Mizuta, Yusuke; Suzuki, Toyoko

2013-01-15

322

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

International Nuclear Information System (INIS)

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

2008-02-24

323

High-throughput thermal scanning for protein stability: making a good technique more robust.  

Science.gov (United States)

We present a high-throughput approach to help define experimental formulations that enhance protein stability, which is based on differential scanning fluorimetry (DSF). The method involves defining the thermal stability of a protein against a screen of 13 buffer systems, systematically sampling pH from 5.0 to 9.0 at high and low salt concentrations, using both redundancy and extensive controls to make the method robust. The screen allows rapid determination of a suitable base formulation for protein samples, and is particularly useful for difficult samples: those that are rapidly degraded or cannot be sufficiently concentrated for downstream analyses. Data obtained from three samples in this assay illustrate the vastly different values for thermal stability that can be obtained from different formulations. This approach is simple to interpret and reliable enough that it has been implemented as a service through the Collaborative Crystallisation Centre (C3). PMID:23710551

Seabrook, Shane A; Newman, Janet

2013-08-12

324

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-08-07

325

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

1998-01-01

326

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 highe...

2011-01-01

327

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

In the eastern Black Sea, we determined methane (CH4) concentrations, gas hydrate volumes, and their vertical distribution from combined gas and chloride (Cl?) measurements within pressurized sediment cores. The total gas volume collected from the cores corresponded to concentrations of 1.2–1.4 mol CH4 kg?1 porewater at in-situ pressure, which is equivalent to a gas hydrate saturation of 15?...

2011-01-01

328

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

Directory of Open Access Journals (Sweden)

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

Ali Ahmad Ghotbi

2012-04-01

329

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

1998-06-10

330

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

1993-01-01

331

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

1996-06-12

332

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

Food by-products in Iran are produced in high levels. In this study, in situ and in vitro gas production techniques were used to describe nutritive value of apple pomace, tomato pomace and noodle waste. For this purpose two ruminal fistulated sheep were used. Nylon bags which were approximately (6×12 cm) containing 5 g samples (2 mm screen) were incubated in duplicate in the rumen of fistulated sheep for 0,2,4,6,8,12,16,24,36 and 48 h. The gas production was recorded after 2, 4, 6, 8, 1...

2008-01-01

333

In-situ fluorimetry: A powerful non-invasive diagnostic technique for natural dyes used in artefacts. Part II. Identification of orcein and indigo in Renaissance tapestries  

Science.gov (United States)

In this paper, three Renaissance tapestries depicting scenes painted by Raffaello Sanzio, conserved at the Vatican Museum, were investigated using in-situ UV-Visible fluorimetric measurements. The results show that this technique is suitable for the detection of natural organic colorants used for dyeing the threads woven in these tapestries. The emission signals detected on red-purple colours were assigned to the colorant orcein and those on different nuances of blue and green colours to indigo by comparison with data from reference laboratory samples. The assignments were supported by chromatographic experiments carried out on threads taken from the back side of the tapestry in the same points analysed by spectrofluorimentry.

Clementi, C.; Miliani, C.; Romani, A.; Santamaria, U.; Morresi, F.; Mlynarska, K.; Favaro, G.

2009-01-01

334

Structural study on Ni nanowires in an anodic alumina membrane by using in situ heating extended x-ray absorption fine structure and x-ray diffraction techniques  

Science.gov (United States)

Polycrystalline Ni nanowires have been prepared by electrochemical deposition in an anodic alumina membrane template with a nanopore size of about 60 nm. In situ heating extended x-ray absorption fine structure and x-ray diffraction techniques are used to probe the atomic structures. The nanowires are identified as being mixtures of nanocrystallites and amorphous phase. The nanocrystallites have the same thermal expansion coefficient, of 1.7 × 10-5 K-1, as Ni bulk; however, the amorphous phase has a much larger thermal expansion coefficient of 3.5 × 10-5 K-1. Details of the Ni nanowire structures are discussed in this paper.

Cai, Quan; Zhang, Junxi; Chen, Xing; Chen, Zhongjun; Wang, Wei; Mo, Guang; Wu, Zhonghua; Zhang, Lide; Pan, Wei

2008-03-01

335

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

International Nuclear Information System (INIS)

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

2013-01-01

336

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Hillebrand, Malte

2008-01-01

337

[Physical stability of imidacloprid suspension concentrate studied by the multiple light scattering technique].  

Science.gov (United States)

The stability of pesticide SC suspension was studied by Turbiscan Lab Analyzer. The Turbiscan Lab can be used to analyze the concentrated colloids, dispersant samples, and the instable mechanism of the suspension system in the initial stage. The Turbiscan Lab can also determine the thickness changes of sedimentation with the time, the settling rate of particles with time, and the particle size changes with time. In the present work, the different dispersant GY-D10, NNO, Morwet D-425, TERSPERSE 2425 were used to prepare the imidacloprid 350 g x L(-1) suspension concentrate in the same preparation condition. By measuring the light intensity of backscattering light of the suspension of imidacloprid 350 g x L(-1) SC with time, the dynamic sedimentation processes and the particle size changes which reflect the stability of SC suspension were studied. The results showed that when the contents of GY-D10 dispersant were 4 wt% in the SC, the stability of SC suspension system was relatively good. PMID:23697125

Zhang, Xiao-Jun; Feng, Jian-Guo; Liu, Shang-Zhong; Wu, Xue-Min

2013-02-01

338

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

International Nuclear Information System (INIS)

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

2012-04-01

339

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

CERN Document Server

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

Staples, J W

2005-01-01

340

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

 
 
 
 
341

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

Science.gov (United States)

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

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

2008-01-01

342

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

343

In patients with extensive subcutaneous emphysema, which technique achieves maximal clinical resolution: infraclavicular incisions, subcutaneous drain insertion or suction on in situ chest drain?  

Science.gov (United States)

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: 'In patients with extensive subcutaneous emphysema, which technique achieves maximal clinical resolution: infraclavicular incisions, subcutaneous drain insertion or suction on in situ chest drain?'. Altogether more than 200 papers were found using the reported search, of which 14 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Subcutaneous emphysema is usually a benign, self-limiting condition only requiring conservative management. Interventions are useful in the context of severe patient discomfort, respiratory distress or persistent air leak. In the absence of any comparative study, it is not possible to choose definitively between infraclavicular incisions, drain insertion and increasing suction on an in situ drain as the best method for managing severe subcutaneous emphysema. All the three techniques described have been shown to provide effective relief. Increasing suction on a chest tube already in situ provided rapid relief in patients developing SE following pulmonary resection. A retrospective study showed resolution in 66%, increasing to 98% in those who underwent video-assisted thoracic surgery with identification and closure of the leak. Insertion of a drain into the subcutaneous tissue also provided rapid sustained relief. Several studies aided drainage by using regular compressive massage. Infraclavicular incisions were also shown to provide rapid relief, but were noted to be more invasive and carried the potential for cosmetic defect. No major complications were illustrated. PMID:24572767

Johnson, Charles H N; Lang, Sommer A; Bilal, Haris; Rammohan, Kandadai S

2014-06-01

344

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

Science.gov (United States)

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

Hosanski, J. M.; Ledoux, E.

1982-03-01

345

Bioremediation of diesel-contaminated soils: evaluation of potential in situ techniques by study of bacterial degradation.  

Science.gov (United States)

The development of a simple laboratory methodology allows the implementation of in situ bioremediation of polluted soils with diesel fuel. In this investigation microbiological and chemical analyses and a suitable bioreactor design, were very useful for suggesting the best ways to improve biodegradation extents in a diesel-enriched soil. Biostimulation with inorganic nitrogen and phosphorus produced the best results in a simple bioreactor, with biodegradation extents higher than 90% after 45 days. Also, the addition of activated sludge from a domestic wastewater plant increased the degradation rate to a great extent. In both cases, microbiological studies showed the presence of Acinetobacter sp. degrading most of the hydrocarbons. Simultaneously, a diesel fuel release (approximately 400,000 l) was studied. Samples taken in polluted soil and water revealed that bacteria from the genus Acinetobacter were predominant. In plate studies, Acinetobacter colonies produced a whitish substance with the characteristics of a biosurfactant. Remarkably, the presence of this product was evident at the field site, both in the riverbanks and in the physical recovery plant. The study of the similarities between laboratory results and the diesel spill site strongly suggested that natural conditions at the field site allowed the implementation of in situ bioremediation after physical removal of LNAPL (light nonaqueous-phase liquids). PMID:11995826

Gallego, J L; Loredo, J; Llamas, J F; Vázquez, F; Sánchez, J

2001-01-01

346

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

Science.gov (United States)

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

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

1994-04-01

347

Simulation of structural ?-Zr stability under pressure by molecular dynamic technique  

International Nuclear Information System (INIS)

Based on the molecular dynamics method one investigated into the structural stability of ?-Zr within wide ranges of temperatures and pressures. Interatomic interaction was described by a paired potential calculated in terms of the Animalu pseudopotential model. One selected the potential parameters based on the phonon spectra of ?-Zr. One studied peculiar features of dynamics of ?-? and ?-? transitions under different temperatures and pressures. One discusses the calculation base hysteresis of direct and indirect transitions and its dependence on pressure and temperature. Based on the derived data one plotted lines of phase equilibrium against P-T-phase diagram

2005-10-01

348

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

Energy Technology Data Exchange (ETDEWEB)

This study is focused on the synthesis of zirconia nanopowders stabilized by 6%{sub mol} calcia prepared under hydrothermal conditions using microwave technology. Sodium hydroxide-based hydrolysis of zirconyl chloride solution containing calcium nitrate followed by microwave irradiation at the temperature of 220 {sup o}C for 30 min was sufficient to obtain white powders of crystalline calcia stabilized zirconia. By means of X-ray diffraction and transmission electron microscopy, it was shown that tetragonal zirconia nanocrystallites with a size of ca 7 nm and diameter/standard deviation ratio of 0.10 were formed. The effects of the [Ca{sup 2+}] and [NaOH] as well as temperature and time of microwave irradiation on the density and specific surface area were evaluated. Sintering test of the tetragonal nanopowders at 1,300 {sup o}C in air was performed in a monomode microwave applicator. The sample was sintered to the density of 95% and the grain size, analyzed by field emission scanning electron microscopy, was in the range from 90 to 170 nm.

Rizzuti, Antonino, E-mail: antonino.rizzuti@unimore.it; Corradi, Anna; Leonelli, Cristina; Rosa, Roberto [University of Modena and Reggio Emilia, Department of Materials and Environmental Engineering (Italy); Pielaszek, Roman; Lojkowski, Witold [Polish Academy of Science, Laboratory of Nanomaterials, Institute of High Pressure Physics (Poland)

2010-01-15

349

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

International Nuclear Information System (INIS)

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

2008-10-15

350

A transposed frequency technique for phase noise and frequency stability measurements  

CERN Multimedia

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

Hartnett, John G; Parker, Stephen

2012-01-01

351

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

Directory of Open Access Journals (Sweden)

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

KOTESWARA RAO.D

2011-02-01

352

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

1997-02-09

353

Stability of spectrometric characteristics of CsI:Tl detectors depending on surface treatment technique  

International Nuclear Information System (INIS)

The effect of different chemical and mechanical methods of CsI:Tl phosphor surface treatment on the quantum efficiency and the energy resolution at ?-particle detection is investigated. The study of CsI:Tl crystal characteristics is carried out for ?-particles with the energy of 5 MeV and 2 MeV. It is found out that the nonlinearity of the light yield and the energy for detected ?-particles increases from 7% at polishing up to 35% at grinding that results in to deterioration of the amplitude resolution. The method for the CsI:Tl surface treatment providing the minimum nonlinearity and the time stability of spectrometric characteristics is proposed

2006-01-01

354

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

International Nuclear Information System (INIS)

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

1993-02-01

355

Net community production of oxygen derived from in vitro and in situ 1-D modeling techniques in a cyclonic mesoscale eddy in the Sargasso Sea  

Directory of Open Access Journals (Sweden)

Full Text Available It has been proposed that the disagreement traditionally reported between in vitro incubation and in situ estimates of oxygen net community production (NCP could be explained, at least partially, by undersampling episodic pulses of net autotrophy associated with mesoscale dynamics. In this study we compare in vitro incubation estimates of net community production with in situ estimates, derived from oxygen profiles and a 1-D model, within a cyclonic eddy investigated in the Sargasso Sea in summer 2004. The in vitro NCP rates measured at the center of the eddy showed a shift from net autotrophy (7±3 mmol O2 m?2 d?1 to net heterotrophy (?25±5 mmol O2 m?2 d?1 from late June to early August. The model-derived NCP rates also showed a temporal decline (19±6 to ?3±7 and 11±8 mmol O2 m?2 d?1, but they were systematically higher than the in vitro estimates and reported net autotrophy or balance for the sampling period. In this comparison episodic pulses in photosynthesis or respiration driven by mesoscale eddies can not explain the discrepancy between the in vitro and in situ estimates of NCP. This points to methodological artefacts or temporal or submesoscale variability as the mechanisms responsible for the disagreement between the techniques, at least in this dataset.

B. Mouriño-Carballido

2009-08-01

356

Design of in situ dispersible and calcium cross-linked alginate pellets as intestinal-specific drug carrier by melt pelletization technique.  

Science.gov (United States)

Conventional alginate pellets underwent rapid drug dissolution and loss of multiparticulate characteristics such as aggregation in acidic medium, thereby promoting oral dose dumping. This study aimed to design sustained-release dispersible alginate pellets through rapid in situ matrix dispersion and cross-linking by calcium salts during dissolution. Pellets made of alginate and calcium salts were prepared using a solvent-free melt pelletization technique that prevented reaction between processing materials during agglomeration and allowed such a reaction to occur only in dissolution phase. Drug release was remarkably retarded in acidic medium when pellets were formulated with water-soluble calcium acetate instead of acid-soluble calcium carbonate. Different from calcium salt-free and calcium carbonate-loaded matrices that aggregated or underwent gradual erosion, rapid in situ solvation of calcium acetate in pellets during dissolution resulted in burst of gas bubbles, fast pellet breakup, and dispersion. The dispersed fragments, though exhibiting a larger specific surface area for drug dissolution than intact matrix, were rapidly cross-linked by Ca(2+) from calcium acetate and had drug release retarded till a change in medium pH from 1.2 to 6.8. Being dispersible and pH-dependent in drug dissolution, these pellets are useful as multiparticulate intestinal-specific drug carrier without exhibiting dose dumping tendency of a "single-unit-like" system via pellet aggregation. PMID:21213311

Nurulaini, Harjoh; Wong, Tin Wui

2011-06-01

357

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

358

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

359

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

Science.gov (United States)

In the eastern Black Sea, we determined methane (CH4) concentrations, gas hydrate volumes, and their vertical distribution from combined gas and chloride (Cl-) measurements within pressurized sediment cores. The total gas volume collected from the cores corresponded to concentrations of 1.2-1.4 mol CH4 kg-1 porewater at in-situ pressure, which is equivalent to a gas hydrate saturation of 15-18% of pore volume and amongst the highest values detected in shallow seep sediments. At the central seep site, a high-resolution Cl- profile resolved the upper boundary of gas hydrate occurrence and a continuous layer of hydrates in a sediment column of 120 cm thickness. Including this information, a more precise gas hydrate saturation of 22-24% pore volume could be calculated. This volume was higher in comparison to a saturation calculated from the Cl- profile alone, resulting in only 14.4%. The likely explanation is an active gas hydrate formation from CH4 gas ebullition. The hydrocarbons at Batumi Seep are of shallow biogenic origin (CH4 > 99.6%), at Pechori Mound they originate from deeper thermocatalytic processes as indicated by the lower ratios of C1 to C2-C3 and the presence of C5.

Heeschen, K. U.; Haeckel, M.; Klaucke, I.; Ivanov, M. K.; Bohrmann, G.

2011-12-01

360

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

Directory of Open Access Journals (Sweden)

Full Text Available In the eastern Black Sea, we determined methane (CH4 concentrations, gas hydrate volumes, and their vertical distribution from combined gas and chloride (Cl? measurements within pressurized sediment cores. The total gas volume collected from the cores corresponded to concentrations of 1.2–1.4 mol CH4 kg?1 porewater at in-situ pressure, which is equivalent to a gas hydrate saturation of 15–18% of pore volume and amongst the highest values detected in shallow seep sediments. At the central seep site, a high-resolution Cl? profile resolved the upper boundary of gas hydrate occurrence and a continuous layer of hydrates in a sediment column of 120 cm thickness. Including this information, a more precise gas hydrate saturation of 22–24% pore volume could be calculated. This volume was higher in comparison to a saturation calculated from the Cl? profile alone, resulting in only 14.4%. The likely explanation is an active gas hydrate formation from CH4 gas ebullition. The hydrocarbons at Batumi Seep are of shallow biogenic origin (CH4 > 99.6%, at Pechori Mound they originate from deeper thermocatalytic processes as indicated by the lower ratios of C1 to C2–C3 and the presence of C5.

K. U. Heeschen

2011-12-01

 
 
 
 
361

Nanostructured PbO materials obtained in situ by spray solution technique for Li-ion batteries  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a systematic study of the effect of various spray pyrolysis parameters, such as temperature, solution concentration and solution flow rate on the morphology, crystallization process, crystal size, specific surface area and electrochemical performance of in situ prepared {alpha}-PbO spherically agglomerated nano-structured powders. Different analytical methods such as XRD, SEM, TEM, BET gas sorption specific surface area measurements and electrochemical tests were performed. Crystallites in the range of 20-120nm and easily dispersed powders were reproducibly prepared by optimization of the spray conditions. An increase of the temperature from 600 to 800{sup o}C was found to lead to a three times increase in the average crystal size, from 31 to 102nm. An increase of concentration from 0.15 to 0.5M dramatically suppresses the crystal size from 127 to 25nm. The BET surface area of sprayed PbO powders is increased up to 6.6m{sup 2}g{sup -1}. For such PbO powders applied as anode materials in Li-ion batteries, we have managed to retain a reversible capacity above 60mAhg{sup -1} beyond 50 cycles. (author)

Konstantinov, K.; Ng, S.H.; Wang, J.Z.; Wang, G.X.; Liu, H.K. [Institute for Superconducting and Electronic Materials, University of Wollongong, NSW 2522 (Australia); Wexler, D. [Faculty of Engineering, University of Wollongong, NSW 2522 (Australia)

2006-09-13

362

Techniques for complex ?-spectra processing under conditions of nonsufficient stability of a spectrometric channel  

International Nuclear Information System (INIS)

Considered is a method of complex ? spectra unfolding under conditions of nonsufficient stability of spectrometric channel. In this case it is proposed to process only some of the regions of spectra, containing main peaks of complete absorption. On the basis of spectra simulation developed is an algorithm of the choice of regions of spectra summation. Summation of readings in observed photopeaks can be carried out both directly in selected regions with fixed boundaries and using program search. To analyze samples according to the proposed method of the choice of observed spectrum regions used are photopeaks with energies of 0.511; 0.845; 1.178; 2.168; 3.118 MeV corresponding to NiSi, P, K and Cl. A test analysis of samples on the element content according to the choice of observed regions with automatic search of summation boundaries in the used photopeaks of the spectrum has given better results than the processing of the whole spectrum during the analyzer drift at+-1 channel of and during the drift of gain factor up to 2%. It is noted, that the proposed method of ? spectra unfolding according to observed regions of spectra considerably reduces the necessary uptime

1979-03-30

363

Thermal stability of the Mobil Five type metallosilicate molecular sieves-An in situ high temperature X-ray diffraction study  

International Nuclear Information System (INIS)

We have carried out in situ high temperature X-ray diffraction (HTXRD) studies of silicalite-1 (S-1) and metallosilicate molecular sieves containing iron, titanium and zirconium having Mobil Five (MFI) structure (iron silicalite-1 (FeS-1), titanium silicalite-1 (TS-1) and zirconium silicalite-1 (ZrS-1), respectively) in order to study the thermal stability of these materials. Isomorphous substitution of Si4+ by metal atoms is confirmed by the expansion of unit cell volume by X-ray diffraction (XRD) and the presence of Si-O-M stretching band at ?960 cm-1 by Fourier transform infrared (FTIR) spectroscopy. Appearance of cristobalite phase is seen at 1023 and 1173 K in S-1 and FeS-1 samples. While the samples S-1 and FeS-1 decompose completely to cristobalite at 1173 and 1323 K, respectively, the other two samples are thermally stable upto 1623 K. This transformation is irreversible. Although all materials show a negative lattice thermal expansion, their lattice thermal expansion coefficients vary. The thermal expansion behavior in all samples is anisotropic with relative strength of contraction along 'a' axes is more than along 'b' and 'c' axes in S-1, TS-1, ZrS-1 and vice versa in FeS-1. Lattice thermal expansion coefficients (? v) in the temperature range 298-1023 K were -6.75 x 10-6 K-1 for S-1, -12.91 x 10-6 K-1 for FeS-1, -16.02 x 10-6 K-1 for TS-1 and -17.92 x 10-6 K-1 for ZrS-1. The highest lattice thermal expansion coefficients (? v) obtained were -11.53 x 10-6 K-1 for FeS-1 in temperature range 298-1173 K, -20.86 x 10-6 K-1 for TS-1 and -25.54 x 10-6 K-1 for ZrS-1, respectively, in the temperature range 298-1623 K. Tetravalent cation substitution for Si4+ in the lattice leads to a high thermal stability as compared to substitution by trivalent cations

2007-05-03

364

FINAL REPORT. DEVELOPMENT OF ADVANCED IN-SITU TECHNIQUES FOR CHEMISTRY MONITORING AND CORROSION MITIGATION IN SCWO ENVIRONMENTS  

Science.gov (United States)

The principal objective of this work was to develop sensing technologies and corrosion monitoring techniques for use in Super Critical Water Oxidation (SCWO) systems. SCWO is currently being considered as a volume reduction technology for the pretreatment of Mixed Low Level Nucle...

365

The modified "Wunderer" osteotomy for stabilization of the cleft-premaxilla - A new operative technique.  

Science.gov (United States)

The operative closure of bilateral cleft lip and palate is a difficult procedure that requires in most cases secondary corrections. Besides aesthetic improvements of lip and nose also the rehabilitation of the teeth, in particular of the maxillary arch is important for the improvement of the chewing function and also for the well being of the patient. One of the most disturbing factors for the construction of any type of prosthetic devices, like removable denture, fixed bridge or dental implants is the mobility and often also malposition of the premaxilla. This problem can only be solved by the insertion of bone grafts into the bilateral gaps of the anterior maxillary arch. This procedure however, is difficult due to the narrowness and poor overview that complicates the closure of the nasal mucosa, which is the precondition for the success. For facilitating the operation the premaxilla is osteotomized and reflected anteriorly according to the method of Wunderer (1962). Then, after the much easier closure of the nasal mucosa the bony defects can be filled with autogenous cancellous bone and finally the oral mucosa can be closed. A preoperatively prepared palatal acrylic plate helps to protect the palatal tissue and also stabilizes the position of the premaxilla. The blood supply to the osteotomized premaxilla is secured by a sound soft tissue pedicle of the buccal muco-periosteum. The effectiveness of the blood supply of the premaxilla was examined in experimental studies by several authors. Also investigations of the growth impediments of the premaxilla and the midface revealed that early osteotomies will interfere with the development of this region. Therefore it is advisable to carry out this procedure not before the patient has reached the age of 12-14 years, which is also depending on the race and the gender of the patient. PMID:24630854

Steinhäuser, Emil W

2014-07-01

366

Advances in multichannel ellipsometric techniques for in-situ and real-time characterization of thin films  

Energy Technology Data Exchange (ETDEWEB)

Recent advances in the design of multichannel ellipsometers based on rotating-element principles have significantly increased their power for applications involving in-situ, real-time analysis of thin films and surfaces. These advances include: (i) extensions in the upper spectral limit beyond the typical value of 4.5 eV, and (ii) increases in the number of extracted parameters beyond the usual two, namely the ellipsometric angles ({psi}, {delta}). An extended spectral range is enabled, for example, by use of a tandem light source configuration and a grating spectrograph having two stages of order-sorting filters mounted over the window of the linear array detector. With an upper spectral limit of 6.5 eV, such ellipsometers are particularly useful in growth analysis for wide band gap thin films. The larger parameter set is enabled by use of dual or single rotating compensators for polarization state modulation and/or analysis, replacing the traditional rotating polarizer. For the single rotating-compensator instrument in the PSC{sub r}A configuration, one can extract the Stokes vector of the reflected beam, and thus its degree of polarization. This in turn can provide information on sample thickness variations over the beam cross-section and can suppress the effects of multiply-scattered light so that non-uniform and macroscopically rough surfaces can be analyzed. For the dual rotating compensator in the PC{sub r1}SC{sub r2}A configuration, one can extract the entire Mueller matrix of the sample and thus the characteristics of anisotropic surfaces and thin films. Applications of these advances include studies of thickness evolution of the phase for boron nitride and silicon film growth, and the nature and origin of surface-induced optical anisotropy of (110) silicon.

Collins, R.W. [Department of Physics and Astronomy, University of Toledo, Mail Stop 111, Toledo, OH 43606-3390 (United States)]. E-mail: rcollins@physics.utoledo.edu; An, Ilsin [Department of Physics and Astronomy, University of Toledo, Mail Stop 111, Toledo, OH 43606-3390 (United States); Chen, Chi [Department of Physics and Astronomy, University of Toledo, Mail Stop 111, Toledo, OH 43606-3390 (United States); Ferlauto, A.S. [Department of Physics and Astronomy, University of Toledo, Mail Stop 111, Toledo, OH 43606-3390 (United States); Zapien, J.A. [Department of Physics and Astronomy, University of Toledo, Mail Stop 111, Toledo, OH 43606-3390 (United States)

2004-12-22

367

Advances in multichannel ellipsometric techniques for in-situ and real-time characterization of thin films  

International Nuclear Information System (INIS)

Recent advances in the design of multichannel ellipsometers based on rotating-element principles have significantly increased their power for applications involving in-situ, real-time analysis of thin films and surfaces. These advances include: (i) extensions in the upper spectral limit beyond the typical value of 4.5 eV, and (ii) increases in the number of extracted parameters beyond the usual two, namely the ellipsometric angles (?, ?). An extended spectral range is enabled, for example, by use of a tandem light source configuration and a grating spectrograph having two stages of order-sorting filters mounted over the window of the linear array detector. With an upper spectral limit of 6.5 eV, such ellipsometers are particularly useful in growth analysis for wide band gap thin films. The larger parameter set is enabled by use of dual or single rotating compensators for polarization state modulation and/or analysis, replacing the traditional rotating polarizer. For the single rotating-compensator instrument in the PSCrA configuration, one can extract the Stokes vector of the reflected beam, and thus its degree of polarization. This in turn can provide information on sample thickness variations over the beam cross-section and can suppress the effects of multiply-scattered light so that non-uniform and macroscopically rough surfaces can be analyzed. For the dual rotating compensator in the PCr1SCr2A configuration, one can extract the entire Mueller matrix of the sample and thus the characteristics of anisotropic surfaces and thin films. Applications of these advances include studies of thickness evolution of the phase for boron nitride and silicon film growth, and the nature and origin of surface-induced optical anisotropy of (110) silicon

2004-12-22

368

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

International Nuclear Information System (INIS)

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

2011-11-01

369

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

International Nuclear Information System (INIS)

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

2003-06-01

370

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1997-12-01

371

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

International Nuclear Information System (INIS)

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

2010-11-01

372

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

Directory of Open Access Journals (Sweden)

Full Text Available Telmisartan (TLM is an angiotensin II receptor antagonist used in the treatment of hypertension. According to BCS (biopharmaceutical classification system Telmisartan belongs to class II drug, and it is practically insoluble in water and it shows low dissolution profile and poor absorption. The present study is to improve the solubility of Telmisartan by forming complexation with ?- CD by using four convenient methods viz physical mixing method, kneading method, and solvent evaporation fusion method at different molar ratios of 1:1, dissolution studies were carried out in pH 7.4 phosphate buffer. The cyclodextrin complexes formulated by employing 1:1 (drug: complexing agent with kneading technique showed higher drug release. Keywords: Telmisartan, inclusion complex, ? - cyclodextrin, physical, kneading, solvent evaporation & fusion method.

Rakesh Singh

2013-01-01

373

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

International Nuclear Information System (INIS)

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

2011-09-01

374

Raman spectrosopic characterization of human malignant tissues: implications for a percutaneous optical biopsy technique for in-situ tissue diagnosis  

Science.gov (United States)

Recent advancements in the technique of Raman spectroscopy now make it possible to achieve rapid, minimally invasive and non-destructive characterization of tissues. In order to evaluate the efficacy of this technique for diagnosis, the Raman spectra of normal and neoplastic human tissues (e.g., breast, kidney, liver and colon) were obtained utilizing visible and near-IR excitation. Normal breast tissue and colon adenocarcinoma showed major Raman features due to the presence of carotenoids and lipids. In breast carcinoma, the features due to lipids were attenuated and as fibrosis (desmoplasia) increased, new spectral features attributable to collagen were observed. Samples of normal and neoplastic liver and kidney show unique spectral differences sufficient to permit tissue differentiation.

Redd, Douglas C.; Frank, Christopher J.; Feng, Zhe-Chuan; Gansler, Ted S.; McCreery, Richard L.

1994-01-01

375

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

International Nuclear Information System (INIS)

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

2005-10-03

376

Effect of heat treatment on the structure and stability of multiwalled carbon nanotubes produced by catalytic chemical vapor deposition technique  

International Nuclear Information System (INIS)

Highlights: ? Post synthesis heat treatment of the nanotubes introduces long range ordering of the layer planes. ? Increased purity and thermal stability of the tubes has been achieved by the removal of catalyst impurity. ? Development of the sword-in-scabbard structure in the multiwalled carbon nanotubes due to heat treatment. ? Improved performance (electrical and mechanical) of the polymer composites using heat treated carbon nanotubes as reinforcement. - Abstract: The multiwalled carbon nanotubes (MWCNTs) produced by catalytic chemical vapor deposition (CCVD) route were heat treated to 2500 °C to improve the structure, morphology and purity level. The process has lead to substantial reduction in the catalytic impurity along with an improved thermal stability and degree of graphitization of these tubes that can possibly lead to its better utilization in various applications. The structural changes following heat treatment have been correlated using various characterization techniques such as Raman spectroscopy, X-ray diffraction, scanning electron microscopy, high resolution transmission electron microscopy, thermo gravimetric analysis and electron paramagnetic resonance spectroscopy. The electrical and mechanical properties of the polymer composites prepared with heat treated MWCNT show improved properties over the one prepared by as produced MWCNT.

2012-05-15

377

Capacitance matrix technique for avoiding spurious eigenmodes in the solution of hydrodynamic stability problems by Chebyshev collocation method  

CERN Document Server

We present a simple technique for avoiding physically spurious eigenmodes that often occur in the solution of hydrodynamic stability problems by the Chebyshev collocation method. The method is demonstrated on the solution of the Orr-Sommerfeld equation for plane Poiseuille flow. Following the standard approach, the original fourth order differential equation is factorised into two second-order equations using a vorticity-type auxiliary variable with unknown boundary values which are then eliminated by a capacitance matrix approach. However the elimination is constrained by the conservation of the structure of matrix eigenvalue problem, it can be done in two basically different ways. A straightforward application of the method results in a couple of physically spurious eigenvalues which are either huge or close to zero depending on the way the vorticity boundary conditions are eliminated. The zero eigenvalues can be shifted to any prescribed value and thus removed by a slight modification of the second approac...

Hagan, Jonathan

2012-01-01

378

Obtaining maximal stability with a septal extension technique in East asian rhinoplasty.  

Science.gov (United States)

Recently, in Korea, the septal extension graft from the septum or rib has become a common method of correcting a small or short nose. The success rate of this method has led to the blind faith that it provides superior tip projection and definition, and to the failure to notice its weaknesses. Even if there is a sufficient amount of cartilage, improper separation or fixation might waste the cartilage, resulting in an inefficient operation. Appropriate resection and effective fixation are essential factors for economical rhinoplasty. The septal extension graft is a remarkable procedure since it can control the nasal tip bidirectionally and three dimensionally. Nevertheless, it has a serious drawback since resection is responsible for septal weakness. Safe resection and firm reconstruction of the framework should be carried out. Operating on the basis of the principle of "safe harvest" and rebuilding the structures is important. Further, it is important to learn several techniques to manage septal weakness, insufficient cartilage quantity, and failure of the rigid frame during the surgery. PMID:24511490

Jeong, Jae Yong

2014-01-01

379

The Load Analysis of a Small Grid System and Its Stability Improvement using Modern Techniques  

International Nuclear Information System (INIS)

Load flow study for three phase balanced power system can be carried out using various numerical techniques. The most prominent are Gauss-Seidel and Newton-Raphson methods. Besides these Gauss-Seidel and Newton-Raphson methods some other dedicated software's have also been utilized for such purposes. In this research work Gauss-Seidel and Newton-Raphson methods have been employed with MATLAB program. Three different cases have been studied and analyzed. Initially, the first two cases were analyzed comprising three buses each, while the third case has been analyzed for small grid of six buses. The power flow has been analyzed from different generating units to different loads, and transmission line losses have also been analyzed. The results obtained from the POWER WORLD software for small grid of six nodes has been compared with Gauss-Seidel and Newton-Raphson methods, and found promising results. In addition, the effect of small perturbation on certain node and its consequent reflection on other six nodes has also been analyzed. (author)

2012-01-01

380

Iodination and stability of somatostatin analogues: comparison of iodination techniques. A practical overview.  

Science.gov (United States)

For iodination ((125/127)I) of tyrosine-containing peptides, chloramin-T, Pre-Coated Iodo-Gen(®) tubes and Iodo-Beads(®) (Pierce) are commonly used for in vitro radioligand investigations and there have been reliant vendors hereof for decades. However, commercial availability of these radio-iodinated peptides is decreasing. For continuation of our research in this field we investigated and optimized (radio-)iodination of somatostatin analogues. In literature, radioiodination using here described somatostatin analogues and iodination techniques are described separately. Here we present an overview, including High Performance Liquid Chromatography (HPLC) separation and characterisation by mass spectrometry, to obtain mono- and di-iodinated analogues. Reaction kinetics of (125/127)I iodinated somatostatin analogues were investigated as function of reaction time and concentration of reactants, including somatostatin analogues, iodine and oxidizing agent. To our knowledge, for the here described somatostatin analogues, no (127)I iodination and optimization are described. (Radio-)iodinated somatostatin analogues could be preserved with a >90% radiochemical purity for 1 month after reversed phase HPLC-purification. PMID:23339762

de Blois, Erik; Chan, Ho Sze; Breeman, Wouter A P

2012-01-01