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1

In situ mercury stabilization  

Energy Technology Data Exchange (ETDEWEB)

BNL Royalty Project Internal Status Report. The funds from the allotment of royalty income were used to experimentally explore feasibility of related, potential new techniques based on the Environmental Sciences Department successful technology licensed for the ex situ treatment of mercury. Specifically, this work is exploring the concept of using Sulfur Polymer Cement (SPC) in an in situ application to stabilize and/or remove mercury (Hg) from surficial soil. Patent disclosure forms have been filed for this process. Soil was artificially spiked with 500 ppm Hg and a series of experiments were set up in which SPC rods were placed in the center of a mass of this soil. Some experiments were conducted at 20 C and others at 50 C. After times ranging from 11 to 24 days, these experiments were opened, photographed and the soil was sampled from discrete locations in the containers. The soil and SPC samples were analyzed for Fe and Hg by x-ray fluorescence. The Hg profile in the soil was significantly altered, with concentrations along the outer edge of the soil reduced by as much as 80% from the starting concentration. Conversely, closer to the treatment rod containing SPC, concentrations of Hg were significantly increased over the original concentration. Preliminary results for elevated temperature sample are shown graphically in Figure 2. Apparently the Hg had migrated toward the SPC and reacted with sulfur to form Hg S. This appears to be a reaction between gaseous phases of both S and Hg, with Hg having a greater vapor pressure. The concentration of low solubility HgS (i.e., low leaching properties) developed within 11 days at 50 C and 21 days at 20 C, confirming the potential of this concept.

Fuhrmann, M.; Kalb, P.; Adams, J.

2004-09-01

2

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...

Negim, Osama

3

In situ containment and stabilization of buried waste  

Energy Technology Data Exchange (ETDEWEB)

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

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

1992-11-01

4

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1997-12-31

5

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

International Nuclear Information System (INIS)

[en] 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

1997-01-01

6

In situ stabilization of entrapped elemental mercury.  

UK PubMed Central (United Kingdom)

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.

Devasena M; Nambi IM

2013-09-01

7

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

8

In situ solution mining technique  

International Nuclear Information System (INIS)

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

1978-01-01

9

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

10

In situ vitrification: application analysis for stabilization of transuranic waste  

International Nuclear Information System (INIS)

[en] 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

11

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

12

In situ hybridization technique and the applications in aquaculture  

UK PubMed Central (United Kingdom)

In situ hybridization technique is a new technique rapidly developing. In this paper, the basic principles and a few in situ hybridization techniques were reviewd,and then curent applications of this technique in aquaculture were described, including gene locallization, sex identification, and virus detection and so on. Opinions on the development of the in situ hybridization technique in the future are put forward.

He Yuying; Li Jian; Liu Ping; Wang Qingyin

2005-01-01

13

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1992-11-01

14

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

15

In situ uranium stabilization by microbial metabolites  

International Nuclear Information System (INIS)

[en] Microbial melanin production by autochthonous bacteria was explored in this study as a means to increase U immobilization in U contaminated soil. This article demonstrates the application of bacterial physiology and soil ecology for enhanced U immobilization in order to develop an in situ, U bio-immobilization technology. We have demonstrated microbial production of a metal chelating biopolymer, pyomelanin, in U contaminated soil from the Tims Branch area of the Department of Energy (DOE), Savannah River Site (SRS), South Carolina, as a result of tyrosine amendments. Bacterial densities of pyomelanin producers were >106 cells per g wet soil. Pyomelanin demonstrated U complexing and mineral binding capacities at pH 4 and 7. In laboratory studies, in the presence of goethite or illite, pyomelanin enhanced U sequestration by these minerals. Tyrosine amended soils in a field test demonstrated increased U sequestration capacity following pyomelanin production up to 13 months after tyrosine treatments

2008-01-01

16

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

17

Effective monitoring techniques for assessing structural stability  

Energy Technology Data Exchange (ETDEWEB)

Roof, pillar, and floor instability have long influenced mine safety, ventilation, productivity, and resource recovery. Based on decades of measurements in ten US mines, suitable measurement techniques and preliminary stability evaluation criteria are proposed for prudent structural stability assessments. Three methods that use the changes in rock deformation, fracturing and stress conditions are shown to be useful and effective for routine stability evaluations and show potential for improving safety in underground excavations. 17 refs., 8 figs., 3 tabs.

Maleki, H. (Bureau of Mines, Spokane, WA (United States). Spokane Research Center)

1994-01-01

18

Biomechanical evaluation of segmental occipitoatlantoaxial stabilization techniques.  

UK PubMed Central (United Kingdom)

STUDY DESIGN: Biomechanical study using human cadaveric cervical spines. OBJECTIVE: To evaluate the construct stability of 3 different segmental occipitoatlantoaxial (C0-C1-C2) stabilization techniques. SUMMARY OF BACKGROUND DATA: Different C0-C1-C2 stabilization techniques are used for unstable conditions in the upper cervical spine, all with different degrees of risk to the vertebral artery. Techniques with similar stability but less risk to the vertebral artery may be advantageous. METHODS: Six human cadaveric cervical spines (C0-C5) (age: 74 +/- 5.0 years) were used. After testing the intact spines, instability was created by transecting the transverse and alar ligaments. The spines were instrumented from the occiput to C2 using 3 different techniques which varied in their attachment to C2. All spines had 6 screws placed into the occiput along with lateral mass screws at C1. The 3 variations used in attachment to C2 were (1) C2 crossing laminar screws, (2) C2 pedicle screws, and (3) C1-C2 transarticular screws. The C1 lateral mass screws were removed before placement of the C1-C2 transarticular screws. Range of motion across C0-C2 was measured for each construct. The data were analyzed using repeated measures ANOVA. The following post hoc comparisons were made: (1) intact spine versus each of the 3 techniques, (2) laminar screw technique versus the pedicle screw technique, and (3) laminar screw technique versus the transarticular screw technique. The level of significance was alpha = 0.01 (after Bonferroni correction for 5 comparisons). RESULTS: All 3 stabilization techniques significantly decreased range of motion across C0-C2 compared to the intact spine (P < 0.01). There was no statistical difference among the 3 stabilization methods in flexion/extension and axial rotation. In lateral bending, the technique using C2 crossing laminar screws demonstrated a trend toward increased range of motion compared to the other 2 techniques. CT scans in both axial and sagittal views demonstrated greater proximity to the vertebral artery in the pedicle and transarticular screw techniques compared to the crossing laminar screw technique. CONCLUSION: Occipitoatlantoaxial stabilization techniques using C2 crossing laminar screws, C2 pedicles screws, and C1-C2 transarticular screws offer similar biomechanical stability. Using the C2 crossing laminar screw technique may offer an advantage over the other techniques due to the reduction of the risk to the vertebral artery during C2 screw placement.

Nassos JT; Ghanayem AJ; Sasso RC; Tzermiadianos MN; Voronov LI; Havey RM; Rinella AS; Carandang G; Patwardhan AG

2009-12-01

19

Stabilization of contaminated soils by in situ vitrification  

Energy Technology Data Exchange (ETDEWEB)

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

Jacobs, G.K.; Spalding, B.P. (Oak Ridge National Lab., TN (United States)); Tixier, J.S.; Powell, T.D. (Pacific Northwest Lab., Richland, WA (United States))

1992-01-01

20

Stabilization of contaminated soils by in situ vitrification  

Energy Technology Data Exchange (ETDEWEB)

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

Jacobs, G.K.; Spalding, B.P. [Oak Ridge National Lab., TN (United States); Tixier, J.S.; Powell, T.D. [Pacific Northwest Lab., Richland, WA (United States)

1992-12-31

 
 
 
 
21

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

International Nuclear Information System (INIS)

[en] 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

22

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

23

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

24

Aerobic in situ stabilization of Landfill Konstanz Dorfweiher: leachate quality after 1 year of operation.  

UK PubMed Central (United Kingdom)

Modern landfill understanding points out controlled operation of landfills. Emissions from landfills are caused mainly by anaerobic biodegradation processes which continue for very long time periods after landfill closure. In situ landfill stabilization aims controlled reduction of emissions towards reduced expenditures as well as aftercare measures. Since April 2010, a new in situ stabilization technique is being applied at a pilot scale landfill (BAIV) within Landfill Konstanz Dorfweiher. This new method utilizes intermittent aeration and leachate recirculation for waste stabilization. In this study, influence of this technique on leachate quality is investigated. Among many other parameters, leachate analyses were conducted for COD, BOD(5), NH(4)-N, NO(2)-N, NO(3)-N, TKN and chloride besides continuously on site recorded pH, electrical conductivity and oxidation-reduction potential (ORP). Results from leachate quality analyses showed that biological activity in the landfill was accelerated resulting in initial higher leachate strength and reduced emission potential of landfill. During full scale in situ aeration, ambient conditions differ from optimized laboratory scale conditions which mainly concern temperature increase and deficient aeration of some landfill parts (Ritzkowski and Stegmann, 2005). Thus, as a field application results of this study have major importance on further process optimization and application.

Öncü G; Reiser M; Kranert M

2012-12-01

25

In-situ stabilization of mixed waste contaminated soil  

International Nuclear Information System (INIS)

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

1993-01-01

26

An in situ XRD technique for annealing investigations  

International Nuclear Information System (INIS)

An in situ XRD technique employing a dffractometer equipped with a high temperature camera was used to investigate the annealing behavior of nanocrystalline copper powder produced by mechanical milling. Specimens were annealed isothermally for 12 h at temperatures between 480 and 770 K. The diffraction data was analyzed using a single-profile Fourier analysis technique. The activation energy for diffracting particle growth was determined to be 0.45 eV/atom. 3 refs., 1 fig.

1995-01-01

27

An in situ XRD technique for annealing investigations  

Energy Technology Data Exchange (ETDEWEB)

An in situ XRD technique employing a dffractometer equipped with a high temperature camera was used to investigate the annealing behavior of nanocrystalline copper powder produced by mechanical milling. Specimens were annealed isothermally for 12 h at temperatures between 480 and 770 K. The diffraction data was analyzed using a single-profile Fourier analysis technique. The activation energy for diffracting particle growth was determined to be 0.45 eV/atom. 3 refs., 1 fig.

Hoylman, D.E.; Axtell, S.C.; Robertson, B.W. [Univ. of Nebraska, Lincoln, NE (United States)

1995-12-31

28

In-situ containment and stabilization of buried waste  

International Nuclear Information System (INIS)

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

1993-01-01

29

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

Science.gov (United States)

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.; Baba, Y.; Fujii, R.; Nakamura, M.; Imahori, Y.

2012-10-01

30

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

International Nuclear Information System (INIS)

[en] 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.

2012-10-01

31

Rapid in situ detection of chromosome 21 by PRINS technique  

Energy Technology Data Exchange (ETDEWEB)

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

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

1995-05-08

32

Synthesis of divalent europium borate via in situ reductive techniques.  

UK PubMed Central (United Kingdom)

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%.

Polinski MJ; Cross JN; Villa EM; Lin J; Alekseev EV; Depmeier W; Albrecht-Schmitt TE

2013-07-01

33

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-09-26

34

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

Energy Technology Data Exchange (ETDEWEB)

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

1982-01-01

35

Fluorescence in situ hybridization techniques for cytogenetic and genomic analyses.  

UK PubMed Central (United Kingdom)

Fluorescent in situ hybridization (FISH) is a powerful method to visualize DNA sequences in the context of the whole chromosome. Yet despite the value of FISH analysis for cytogenetic studies, there are surprisingly few labs that are able to adapt the technique for their experiments in chromosomal and genome biology. Here we present a comprehensive FISH protocol acquired from over 20 years of collective experience using different plant species. Our description uses rice as a model for performing a complete FISH procedure, but the protocol can be readily adapted for other plant species. We have provided more specialized instruction beyond routine FISH, which includes the preparation of meiotic and mitotic samples suitable for FISH analysis, procedures for direct and indirect labeling of DNA probes, and techniques for increasing signal strength using layers of antibodies.

Walling JG; Zhang W; Jiang J

2013-01-01

36

In situ tests for evaluating ground treatment techniques  

Energy Technology Data Exchange (ETDEWEB)

Two in-situ tests were carried out to investigate a zone of interest and directly measure properties of the soil as a function of depth. The tests were the seismic cone penetration test (SCPT) and the spectral analysis of surface waves (SASW). The SCPT test provided independent measurement of penetration resistance, pore pressure and shear wave velocity in a fast, continuous and economic manner. The SASW test is based on the dispersion of Raleigh waves of different wave lengths propagating at different depths. Shear wave velocity could be determined directly from this test. Three case histories were presented to demonstrate the ability of the CPT, SCPT and SASW tests to monitor the improvement achieved by dynamic compaction and vibro-replacement techniques. 9 refs.

Woeller, D.J.; Boyd, T.J.; Greig, J.W. [ConeTec Investigations Ltd., Vancouver, BC (Canada); Robertson, P.K. [Alberta Univ., Edmonton, AB (Canada); Beaton, N.F. [GeoPac West Ltd., New Westminster, BC (Canada)

1995-12-31

37

In-situ characterization technique for screening contaminated soils  

Energy Technology Data Exchange (ETDEWEB)

An innovative field sampling system for screening contaminated soils has been developed using laser ablation coupled with inductively coupled plasma-atomic emission spectrometry (LA-ICP-AES) technology. This sampling approach provides in-situ real-time analysis of trace inorganic elements and is conducted through a mobile testing facility that consists of an instrumentation vehicle called the Mobile Demonstration Laboratory for Environmental Screening Technologies (MDLEST) and an attached trailer called the Robotic Sampling Accessory (RSA). The RSA provides automated sampling capabilities through an attached three-degree-of-freedom robot that is equipped with a surface-sampling probe. The MDLEST-RSA was successfully tested at a Department of Energy (DOE) site in Fernald, Ohio, during the fall of 1992. This paper provides a description of the analysis technique, the MDLEST and RSA, and results of the field demonstration. In addition, benefits, limitations, and future plans are also discussed.

Jaselskis, E.J. [Iowa State Univ., Ames, IA (United States); Anderson, M.S.; D`Silva, A.P.; Baldwin, D.P.; Zamzow, D.S. [Ames Lab., IA (United States)

1995-07-01

38

Fluorescence In Situ Hybridization (FISH) Technique for the Micronucleus Test.  

UK PubMed Central (United Kingdom)

In recent years, cytogenetics in combination with molecular methods has made rapid progress, resulting in new molecular cytogenetic methodologies such as fluorescence in situ hybridization (FISH). FISH is a molecular cytogenetic technique used for the detection of specific chromosomal rearrangements and applicable to many different specimen types. It uses fluorescently labeled DNA probes complementary to regions of individual chromosomes. These labeled DNA segments hybridize with the cytological targets in the sample and can be visualized by fluorescence microscopy in interphase nuclei or on metaphase chromosomes. Here, we describe the FISH methodology with centromeric probes for human cells, which is used in combination with the cytokinesis-block micronucleus assay and which allows discrimination between mutagens inducing DNA breakage (clastogens) or chromosome loss (aneugens).

Decordier I; Kirsch-Volders M

2013-01-01

39

Kinetics and characterization of conducting and insulating polymers by in situ and ex situ techniques  

Energy Technology Data Exchange (ETDEWEB)

The kinetics of polypyrrole, polyaniline, polystyrene and polyurethane syntheses were examined using in-situ techniques. The resulting polymers were analyzed by ex-situ analytical techniques. Comparison of results obtained by different techniques was made. Polypyrrole was synthesized by the chemical oxidative route. The polymerization using polymerization using potassium ferricyanide was monitored by Raman spectroscopy, potentiometry and microelectrode analysis. The kinetics were found to resemble exponential decay. The stoichiometry of the polymerization remained constant throughout the experimental period. The polymerization of aniline by ammonium peroxysulfate was monitored by Raman, potentiometry, calorimetry, quartz crystal microbalance (QCM), conductance measurements, viscometry and visible absorption spectroscopy. QCM and visible absorption spectroscopy were used to probe the nucleation stage. The results showed polymerization occurred following an induction period. The induction period of aniline-peroxysulfate system can be reduced by using mixed oxidizers. Cerium(IV) was used as co-oxidant with peroxysulfate. A significant decrease in the induction period was observed with 0.01% of cerium(IV). This effect can also be achieved by adding polyaniline to provide reaction sites for the monomers. The kinetics of styrene polymerization were monitored by Raman. The decrease in the 1630 cm[sup [minus]1] aliphatic C[double bond]C stretching was interpreted as percent styrene conversion. The 1600 cm[sup [minus]1] aromatic C[double bond]C stretching was used as a standard. UV absorption spectroscopy was used to quantify the amount of styrene in the polymerizing mixture. IR spectroscopy and Raman were used to monitor the reaction of modified diphenylmethane-4-4[prime]-diisocyanate (MDI) and polyether polyol (polyol). In the Raman experiment, the decrease in the 1060 cm[sup [minus]1] peak and the increase in the 1140 cm[sup [minus]1] peak were analyzed.

Fong, Y.K.

1993-01-01

40

Depth enhancement techniques for the in situ vitrification process  

Energy Technology Data Exchange (ETDEWEB)

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

Lowery, P.S.; Luey, J.; Seiler, D.K.; Tixier, J.S. [Pacific Northwest Lab., Richland, WA (United States); Timmerman, C.L. [Geosafe Corp., Richland, WA (United States)

1994-11-01

 
 
 
 
41

Depth enhancement techniques for the in situ vitrification process  

International Nuclear Information System (INIS)

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

1994-01-01

42

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.

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

2011-01-01

43

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1997-09-01

44

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

45

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

46

In situ scanning vibrating electrode technique for lithium metal anodes  

Energy Technology Data Exchange (ETDEWEB)

The effect of the inorganic additives to electrolytes, aluminum iodide (AII{sub 3}) and tin(II) iodide, on the charge/discharge coulombic efficiency of a lithium (Li) metal anode has been investigated in binary solvent systems, i.e., propylene carbonate (PC) mixed with 2-methyltetrahydrofuran (2Me-THF) containing lithium perchlorate (LiClO{sub 4}), PC+2Me-THF/LiClO{sub 4}, and PC mixed with 1,2-dimethoxy-ethane (DME) containing LiClO{sub 4}, PC+DME/LiClO{sub 4}. AII{sub 3} improved the coulombic efficiency of the Li metal anode in both the binary solvent systems. Two-dimensional Li ionic currents at the interface of the Li metal anode were monitored by using in situ scanning vibrating electrode technique (SVET) in the representative binary system, PC+2Me-THF/LiClO{sub 4}, in the absence and presence of the additives. The relationship between the coulombic efficiency and the Li ionic current distribution on the anode was discussed. (orig.)

Ishikawa, Masashi; Morita, Masayuki [Yamaguchi Univ., Ube (Japan). Dept. of Applied Chemistry and Chemical Engineering; Matsuda, Yoshiharu [Kansai Univ., Suita (Japan). Dept. of Applied Chemistry

1997-10-01

47

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

48

Fast axisymmetric stability calculations using variational techniques  

International Nuclear Information System (INIS)

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

1991-01-01

49

Measurement techniques for fuel stability characterization  

Energy Technology Data Exchange (ETDEWEB)

Differential scanning calorimetry (DSC) at high pressure was used to measure oxidation onset temperature and gum-forming tendency of shale derived diesel and jet fuels. Less than 1 mg of fuel was required for each test. For measuring oxidation onset temperature the scanning mode of the DSC instrument was used, with a heating rate of 40/sup 0/C per minute and oxygen pressure of 520 psia. For measurement of gum-forming tendency, the fuel was first oxidized in the DSC at 170/sup 0/C and oxygen pressure of 650 psia. The oxidized residue was then heated slowly in a thermogravimetric analyzer and gum content computed from the weight loss curve. The DSC results for the shale-derived fuels were compared to the results for a petroleum jet fuel. It was found that the shale-derived marine diesel fuel was less resistant to oxidation and formed more gum than the petroleum jet fuels. The shale-derived jet fuels were more stable than the petroleum jet fuel. The results of the DSC tests were also compared with accelerated stability tests and JFTOT tests. There was qualitative correspondence between the DSC tests results and the accelerated stability and JFTOT results.

Cummings, A.L.; Pei, P.; Hsu, S.M.

1983-01-01

50

High Resolution Sensing Techniques for Slope Stability Studies.  

Science.gov (United States)

The National Bureau of Standards (NBS), in conjunction with the U.S. Geological Survey (USGS), conducted a four-phase evaluation of high resolution remote sensing techniques for application to problems of determining slope stability. The first two phases,...

R. L. Jesch R. B . Johnson D. R. Belsher A. D. Yaghjian M. C. Steppe

1979-01-01

51

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

52

Power system stabilizers based on modern control techniques  

Energy Technology Data Exchange (ETDEWEB)

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

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

1994-12-31

53

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

Energy Technology Data Exchange (ETDEWEB)

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

Kalb,P.D.; Milian, L.

2008-03-01

54

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

UK PubMed Central (United Kingdom)

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

Pawar P; Kashyap H; Malhotra S; Sindhu R

2013-01-01

55

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

Science.gov (United States)

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

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

2013-01-01

56

In-situ stabilization of radioactive zirconium swarf  

Energy Technology Data Exchange (ETDEWEB)

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

Hess, Clay C. (Idaho Falls, ID)

1999-01-01

57

Stabilization of microorganisms for in situ degradation of toxic chemicals  

International Nuclear Information System (INIS)

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

1993-01-01

58

Stabilization of microorganisms for in situ degradation of toxic chemicals  

Energy Technology Data Exchange (ETDEWEB)

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

Crawford, R.L.; Ralston, D.R.

1993-01-01

59

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

UK PubMed Central (United Kingdom)

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.

Akiva-Tal A; Kababya S; Balazs YS; Glazer L; Berman A; Sagi A; Schmidt A

2011-09-01

60

In situ molecular NMR picture of bioavailable calcium stabilized as amorphous CaCO3 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 Ca2+ 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 CaCO3, 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 C?P distance), an interaction that must be mediated by Ca2+. 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 CaCO3. Solid state NMR spectroscopy is shown to be a robust and accessible means of determining composition, internal structure, and molecular functionality in situ.

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

2011-01-01

 
 
 
 
61

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

2011-08-22

62

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

International Nuclear Information System (INIS)

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

2005-01-01

63

Improved physical stability and injectability of non-aqueous in situ PLGA microparticle forming emulsions.  

UK PubMed Central (United Kingdom)

The goal of this study was to obtain physically stable non-aqueous in situ forming microparticle (ISM) emulsions capable of forming biodegradable microparticles upon injection. ISM emulsions consist of a biocompatible organic PLGA solution dispersed in a continuous oil phase prepared in a two-syringe/connector system prior to administration. A variety of parenteral approved excipients were tested for a stability-enhancing effect and possible stabilization mechanisms evaluated. Glycerol monostearate (GMS) showed superior stabilizing potential prolonging the emulsion stability from a few minutes to more than 12h. Flow behavior analysis, differential scanning calorimetry, polarized light- and Cryo-electron microscopy revealed, that the stabilization was caused by an immediate, more than 5-fold viscosity increase in the continuous phase after emulsification and by a stabilized interface through a liquid crystalline GMS layer around the polymer solution droplets. Despite the viscosity increase the injectability of the stabilized ISM emulsion was improved by about 30% compared to the corresponding highly viscous PLGA solution (in situ implant) due to a pronounced shear thinning of the GMS containing oil phase. The injectability improvement allows a faster administration or enables the use of thinner needles and hence reduced patient discomfort.

Voigt M; Koerber M; Bodmeier R

2012-09-01

64

Depth enhancement techniques for the in situ vitrification process.  

Science.gov (United States)

In-situ vitrification (ISV) is a process by which electrical energy is supplied to a soil/waste matrix. The resulting Joule heat raises the temperature of the soil/waste matrix, producing a pool of molten soil. Since its inception, there have been many su...

P. S. Lowery J. Luey D. K. Seiler J. S. Tixier C. L. Timmerman

1994-01-01

65

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

66

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1994-10-01

67

Polyphosphate Remediation Technology for In-Situ Stabilization of Uranium  

International Nuclear Information System (INIS)

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

2009-01-01

68

Ignition technique for an in situ oil shale retort  

Energy Technology Data Exchange (ETDEWEB)

A generally flat combustion zone is formed across the entire horizontal cross-section of a fragmented permeable mass of formation particles formed in an in situ oil shale retort. The flat combustion zone is formed by either sequentially igniting regions of the surface of the fragmented permeable mass at successively lower elevations or by igniting the entire surface of the fragmented permeable mass and controlling the rate of advance of various portions of the combustion zone.

Cha, Chang Y. (Golden, CO)

1983-01-01

69

In-situ restoration techniques for aquifers contaminated with hazardous wastes  

Energy Technology Data Exchange (ETDEWEB)

Improper disposal of hazardous wastes is a threat to the nation's ground-water supply. Methods that prevent contamination are probably the most-effective techniques to protect ground water. Once contamination problems occur, there are a number of in-situ techniques that can be used to cleanse the ground water and at least partially restore the aquifer. Chemical and physical treatment techniques include processes such as neutralization, chemical reaction, extraction and immobilization. Biological techniques for in-situ treatment generally involve enhancing the degradative capacity of the indigenous microflora or the addition of organisms acclimated to degrade the contaminants.

Lee, M.D.; Wilson, J.T.; Ward, C.H.

1987-01-01

70

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

71

Sensitivity of BWR stability calculations to numerical integration techniques  

Energy Technology Data Exchange (ETDEWEB)

Computer simulations have shown that stability calculations in boiling water reactors (BWRs) are very sensitive to a number of input parameters, modeling assumptions, and numerical integration techniques. Following the 1988 LaSalle instability event, a significant industry-wide effort was invested in identifying these sensitivities. One major conclusion from these studies was that existing time-domain codes could best predict BWR stability by using explicit methods for the energy equation with a Courant number as close to unity as possible. This paper presents a series of sensitivity studies using simplified models, which allow us to determine the effect that different numerical integration techniques have on the results of stability calculations. The present study appears to indicate that, even though using explicit integration with a Courant number of one is adequate for existing codes using time-integration steps of less than 10 ms, second-order solution techniques for the time integration can result in significant improvements in the accuracy of linear (i.e., decay ratio) stability calculations.

Peiro, D.G. [Universidad Politecnica de Valencia (Spain). Departamento de Matematica Aplicada; March-Leuba, J. [Oak Ridge National Lab., TN (United States)

1997-11-01

72

Initial tests on in situ vitrification using electrode feeding techniques  

Energy Technology Data Exchange (ETDEWEB)

This report summarizes the results of an engineering-scale in situ vitrification (ISV) test conducted to demonstrate the potential for electrode feeding in soils with a high concentration of metals. The engineering-scale test was part of a Pacific Northwest Laboratory (PNL) program to assist Idaho National Engineering Laboratory (INEL) in conducting treatability studies of the potential for applying ISV to the mixed transuranic waste buried at the INEL subsurface disposal area. The purpose of this test was to evaluate the effectiveness of both gravity fed and operator-controlled electrode feeding in reducing or eliminating many of the potential problems associated with fixed-electrode processing of soils with high concentrations of metal. Actual site soils from INEL were mixed with representative concentrations of carbon steel and stainless steel for this engineering-scale test. 18 refs., 14 figs., 3 tabs.

Farnsworth, R.K.; Oma, K.H.; Bigelow, C.E.

1990-05-01

73

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

International Nuclear Information System (INIS)

[en] 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

74

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-01-01

75

Lumbar spine fusion and stabilization: hardware, techniques, and imaging appearances.  

Science.gov (United States)

Stabilization and fusion of the lumbar spine may be performed by using various anterior and posterior surgical techniques and a wide range of devices, including screws, spinal wires, artificial ligaments, vertebral cages, and artificial disks. Because spinal procedures are increasingly common, such devices are seen more and more often in everyday radiologic practice. For evaluation of the postoperative spine, radiography is the modality most commonly used. Computed tomography and magnetic resonance (MR) imaging may be useful alternatives, but MR imaging of the postoperative spine is vulnerable to metal-induced artifacts. For an accurate postoperative assessment of spinal instrumentation and of any complications, it is important that radiologists be familiar with the normal imaging appearances of the lumbar spine after stabilization, fusion, and disk replacement with various techniques and devices. PMID:18025515

Rutherford, Elizabeth E; Tarplett, Linda J; Davies, Evan M; Harley, John M; King, Leonard J

76

Technique for in situ morphologic analysis of colony-forming units (CFU) grown in semisolid media  

International Nuclear Information System (INIS)

[en] A technique for in situ morphologic analysis of mammalian cells derived from blood-forming organs and cultured in semisolid media has been developed. The technique is used to study colony-forming units of the granulocyte-macrophage series (CFU-C) and of the lymphocytic series (CFU-L). In addition, the technique is used to anlyze colonies grown in semisolid media in mixed lymphocyte cultures

1979-01-01

77

In situ focus characterization by ablation technique to enable optics alignment at an XUV FEL source.  

Science.gov (United States)

In situ focus characterization is demonstrated by working at an extreme ultraviolet (XUV) free-electron laser source using ablation technique. Design of the instrument reported here allows reaching a few micrometres resolution along with keeping the ultrahigh vacuum conditions and ensures high-contrast visibility of ablative imprints on optically transparent samples, e.g., PMMA. This enables on-line monitoring of the beam profile changes and thus makes possible in situ alignment of the XUV focusing optics. A good agreement between focal characterizations retrieved from in situ inspection of ablative imprints contours and from well-established accurate ex situ analysis with Nomarski microscope has been observed for a typical micro-focus experiment. PMID:23822375

Gerasimova, N; Dziarzhytski, S; Weigelt, H; Chalupský, J; Hájková, V; Vyšín, L; Juha, L

2013-06-01

78

In situ focus characterization by ablation technique to enable optics alignment at an XUV FEL source  

Energy Technology Data Exchange (ETDEWEB)

In situ focus characterization is demonstrated by working at an extreme ultraviolet (XUV) free-electron laser source using ablation technique. Design of the instrument reported here allows reaching a few micrometres resolution along with keeping the ultrahigh vacuum conditions and ensures high-contrast visibility of ablative imprints on optically transparent samples, e.g., PMMA. This enables on-line monitoring of the beam profile changes and thus makes possible in situ alignment of the XUV focusing optics. A good agreement between focal characterizations retrieved from in situ inspection of ablative imprints contours and from well-established accurate ex situ analysis with Nomarski microscope has been observed for a typical micro-focus experiment.

Gerasimova, N.; Dziarzhytski, S.; Weigelt, H. [Deutsches Electronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg (Germany); Chalupsky, J.; Hajkova, V.; Vysin, L.; Juha, L. [Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 18221 Prague (Czech Republic)

2013-06-15

79

Practical methods for estimating in situ stresses for borehole stability applications in sedimentary basins  

Energy Technology Data Exchange (ETDEWEB)

In order to predict whether the walls of a proposed well will be stable or will spall, it is necessary to specify the far field in situ stresses that will be experienced by the wellbore. This article does not pretend to describe optimal stress measurement methods, or techniques for extracting information from inclined wells. Instead, it outlines how to estimate stress orientations and magnitudes with average data suites and it alludes to mapping applications.

Bell, J.S. [Sigma H Consultants Ltd., Box 2797, Invermere, BC (Canada) V0A 1K0

2003-06-01

80

A neuro power system stabilizer based on adaptive control technique  

Energy Technology Data Exchange (ETDEWEB)

A power system stabilizer based on GMV (Generalized Minimum Variance), one of the adaptive control techniques, is developed to enhance the dynamic performances of a power system using an Artificial Neural Network (ANN). The stabilizer consists of two parts. One part is Inverse Dynamics Neural Networks (IDNN), which is trained to identify the inverse dynamics of controlled plant and used as a one-step ahead controller, or inverse controller. The other part is Adaptive Reference Model (ARM), which prevents excessive controller output. The ARM produces the modified reference value by minimizing a cost function recursively on the assumption that the IDNN perfectly identifies the controlled plant. The IDNN is used in the minimization procedure to calculate the sensitivities. The proposed controller is simulated in a typical one-machine-infinite-bus power system to show its effectiveness to damp sustained low frequency oscillation. (author)

Park, Y.M.; Hyun, S.O.; Lee, J.H. [Seoul National Univ. (Korea, Republic of). Dept. of Electrical Engineering

1996-12-31

 
 
 
 
81

Using geophysical techniques to control in situ thermal remediation  

Energy Technology Data Exchange (ETDEWEB)

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

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

1994-01-22

82

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.

1994-01-01

83

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&t...

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

84

Analysis of the hollow inclusion technique for measuring in situ rock stress  

Energy Technology Data Exchange (ETDEWEB)

The complete mathematical analysis is given for a method of measuring the in situ state of stress in a rock mass. The technique consists of cementing a tubular probe containing strain gauges into a hole in the rock. The probe is then overcored releasing the strains in the rock. This technique is compared with two related techniques, in which either strain gauges are cemented to the rock surface, or a solid probe containing the gauges is cemented in a hole. The equations derived reduce to those of the other techniques as special cases.

Fama, M.E.D.; Pender, M.J.

1980-06-01

85

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

Energy Technology Data Exchange (ETDEWEB)

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{sup -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.

Satyawali, Yamini; Schols, Edo; Van Roy, Sandra; Dejonghe, Winnie; Diels, Ludo [Separation and Conversion Technology, Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol (Belgium); Vanbroekhoven, Karolien, E-mail: karolien.vanbroekhoven@vito.be [Separation and Conversion Technology, Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol (Belgium)

2010-09-15

86

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2008-02-25

87

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.

2008-01-01

88

In situ vitrification - A potential remedial action technique for hazardous wastes  

International Nuclear Information System (INIS)

In situ vitrification (ISV) is an innovative technology being developed as a potential method for stabilizing transuranic (TRU) contaminated wastes in place. Although the process is being developed for TRU contaminated wastes, it is envisioned that the process could also be applied to hazardous chemical wastes. In situ vitrification (ISV) is the conversion of contaminated soil into a durable glass and crystalline wastes form through melting by joule heating. The technology for in situ vitrification is based upon electric melter technology developed at the Pacific Northwest Laboratory (PNL) for the immobilization of high-level nuclear waste. In situ vitrification was initially tested by researchers at PNL in August, 1980 (U.S. Patent 4,376,598). Since then, ISV has grown from a concept to an emerging technology through a series of 21 engineering-scale (laboratory) tests and 7 pilot-scale (field) tests. A large-scale system is currently being fabricated for testing. The program has been sponsored by the U.S. Department of Energy's (DOE) Richland Operations Office for potential application to Hanford TRU contaminated soil sites. A more detailed description outlining the power system design and the off-gas treatment system follows

1984-01-01

89

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

Energy Technology Data Exchange (ETDEWEB)

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

Yu, N.; Sickafus, K.E.; Kodali, P.; Nastasi, M.

1996-04-01

90

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

91

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

Directory of Open Access Journals (Sweden)

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

Kalra Samir; Jain Vijendra; Jaiswal Awadesh; Behari Sanjay

2007-01-01

92

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 deg 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

93

Stabilization of peptide-based vesicles via in situ oxygen-mediated cross-linking.  

Science.gov (United States)

Reversible vesicles from poly(L-glutamic acid)(65) -block-poly[(L-lysine)-ran-(L-3,4-dihydroxyphenylalanine)](75) [PLGA(65)-b-P(LL-r-DOPA)(75)] block copolypeptide adopt different configurations depending on the surrounding pH. At pH = 3, AFM and TEM images show ellipsoidal morphologies, whereas at pH = 12 both TEM and AFM reveal the formation of hollow vesicles. At pH = 12, the P(LL-r-DOPA) block forms the internal layer of the vesicle shell and the subsequent oxygen-mediated oxidation of the phenolic groups of the DOPA lead to the formation of quinonic intermediates, which undergo intermolecular dimerization to stabilize the vesicles via in situ cross-linking. Consequently, the vesicles maintain their shape even when the pH is reversed back to 3, as confirmed by AFM and TEM. PMID:22807238

Sulistio, Adrian; Blencowe, Anton; Wang, Jiapei; Bryant, Gary; Zhang, Xiaoqing; Qiao, Greg G

2012-07-13

94

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

Science.gov (United States)

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

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

2012-09-01

95

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

DEFF Research Database (Denmark)

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

Teran-Escobar, Gerardo; Tanenbaum, David

2012-01-01

96

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

UK PubMed Central (United Kingdom)

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.

Teran-Escobar G; Tanenbaum DM; Voroshazi E; Hermenau M; Norrman K; Lloyd MT; Galagan Y; Zimmermann B; Hösel M; Dam HF; Jørgensen M; Gevorgyan S; Kudret S; Maes W; Lutsen L; Vanderzande D; Würfel U; Andriessen R; Rösch R; Hoppe H; Rivaton A; Uzuno?lu GY; Germack D; Andreasen B; Madsen MV; Bundgaard E; Krebs FC; Lira-Cantu M

2012-09-01

97

In situ zymography: a molecular pathology technique to localize endogenous protease activity in tissue sections.  

UK PubMed Central (United Kingdom)

Proteases play important roles in modulating a wide range of cellular functions, in the regulation of biologic processes, and in the pathogenesis of various diseases. Several molecular techniques are available to identify and characterize proteases in cells and tissues. Most of these techniques do not provide information on the activity of proteases in tissues. In situ zymography (ISZ) is a relatively low-cost technique that uses specific protease substrates to detect and localize specific protease activities in tissue sections. Used in combination with other techniques, ISZ provides data that further our understanding of the role of specific proteases in various pathologic and physiologic conditions. This review describes the general principle of ISZ and highlights the past and future applications of this technique in molecular pathology.

Yan SJ; Blomme EA

2003-05-01

98

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

99

Performance of the In Situ Microcosm Technique for Measuring the Degradation of Organic Chemicals in Aquifers  

DEFF Research Database (Denmark)

An in situ microcosm (ISM) consists of a stainless steel cylinder isolating about 2 L of the aquifer and is equipped with valves allowing for loading and sampling from the ground surface. During the last five years, this technique has been used frequently to study the degradation of organic chemicals in polluted and pristine aquifers representing different redox environments. The ISM technique has great potential for providing field-relevant degradation potentials and rate constants, but care must be taken in using the equipment and interpreting the results. This paper provides details concerning the installation and operation of an ISM and presents experiences concerning data interpretation and monitoring of redox conditions

Nielsen, Per H.; Christensen, Thomas HØjlund

1996-01-01

100

Performance of the in situ microcosm technique for measuring the degradation of organic chemicals in aquifers  

Energy Technology Data Exchange (ETDEWEB)

An in situ microcosm (ISM) consists of a stainless steel cylinder isolating about 2 L of the aquifer and is equipped with valves allowing for loading and sampling from the ground surface. During the last five years, this technique has been used frequently to study the degradation of organic chemicals in polluted and pristine aquifers representing different redox environments. The ISM technique has great potential for providing field-relevant degradation potentials and rate constants, but care must be taken in using the equipment and interpreting the results. This paper provides details concerning the installation and operation of an ISM and presents experiences concerning data interpretation and monitoring of redox conditions.

Nielsen, P.H.; Christensen, T.H.; Albrechtsen, H.J.; Gillham, R.W.

1996-05-01

 
 
 
 
101

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

UK PubMed Central (United Kingdom)

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

Yang L; Raza A; Si Y; Mao X; Shang Y; Ding B; Yu J; Al-Deyab SS

2012-10-01

102

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

Science.gov (United States)

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

103

Use of radioactive isotopes for stability investigations in formulation techniques  

International Nuclear Information System (INIS)

Using the active agents dimethoate and 1-butylaminocyclohexanephosphonic acid dibutyl ester as examples, the advantages of the application of radioactively labelled compounds are shown for studying the following subject matters: storage stability of the pure active substance and its formulations; effects of selected impurities on storage stability; selection of suitable binding materials, solvents, and organic compounds as chemical stabilizers for formulations. (author)

1979-01-01

104

In situ aqueous derivatization as sample preparation technique for gas chromatographic determinations.  

Science.gov (United States)

The use of derivatization reactions is a common practice in analytical laboratories. Although in many cases it is tedious and time-consuming, it does offer a good alternative for the determination of analytes not compatible to gas chromatography. Many of the reactions reported in the literature occur in organic medium. However, in situ aqueous derivatization reactions, which can be performed directly in aqueous medium, offer important advantages over those mentioned above, such as no need of a previous extraction step and easy automation. Here we review the most recent developments and applications of in situ aqueous derivatization. The discussion focuses on the derivatization reactions used for the determination of alcohols and phenols, carboxylic acids, aldehydes and ketones, nitrogen-containing compounds and thiols in different aqueous matrices, such as environmental, biological and food samples. Several reactions are described for each functional group (acylation, alkylation, esterification, among others) and, in some cases, the same reagents can be used for several functional groups, such that there is an unavoidable overlap between sections. Finally, attention is also focused on the techniques used for the introduction of the derivatives formed in the aqueous medium into the chromatographic system. The implementation of in situ aqueous derivatization coupled to preconcentration techniques has permitted the enhancement of recoveries and improvements in the separation, selectivity and sensitivity of the analytical methods. PMID:23726081

Ferreira, Ana María Casas; Laespada, María Esther Fernández; Pavón, José Luis Pérez; Cordero, Bernardo Moreno

2013-05-10

105

In situ aqueous derivatization as sample preparation technique for gas chromatographic determinations.  

UK PubMed Central (United Kingdom)

The use of derivatization reactions is a common practice in analytical laboratories. Although in many cases it is tedious and time-consuming, it does offer a good alternative for the determination of analytes not compatible to gas chromatography. Many of the reactions reported in the literature occur in organic medium. However, in situ aqueous derivatization reactions, which can be performed directly in aqueous medium, offer important advantages over those mentioned above, such as no need of a previous extraction step and easy automation. Here we review the most recent developments and applications of in situ aqueous derivatization. The discussion focuses on the derivatization reactions used for the determination of alcohols and phenols, carboxylic acids, aldehydes and ketones, nitrogen-containing compounds and thiols in different aqueous matrices, such as environmental, biological and food samples. Several reactions are described for each functional group (acylation, alkylation, esterification, among others) and, in some cases, the same reagents can be used for several functional groups, such that there is an unavoidable overlap between sections. Finally, attention is also focused on the techniques used for the introduction of the derivatives formed in the aqueous medium into the chromatographic system. The implementation of in situ aqueous derivatization coupled to preconcentration techniques has permitted the enhancement of recoveries and improvements in the separation, selectivity and sensitivity of the analytical methods.

Ferreira AM; Laespada ME; Pavón JL; Cordero BM

2013-06-01

106

Genomic affinities in Turnera (subseries Turnera, Turneraceae) inferred by in situ hybridization techniques.  

UK PubMed Central (United Kingdom)

Subseries Turnera comprises a polyploid complex with ploidy levels ranging from diploid (2n = 2x = 10) to octoploid (2n = 8x = 40). The use of fluorescent in situ hybridization greatly improved the knowledge of the karyotypes of Turnera species by detecting and mapping rDNA sites. Interspecific variability in the number of sites was detected, but not in correlation with the ploidy level. A chromosome pair with a strong hybridization signal was always visible and this signal corresponded to the secondary constriction detectable by conventional techniques. Genomic in situ hybridization experiments combined with information on meiotic pairing in species and interspecific hybrids revealed that homologies detected by molecular analysis are greater than those detected by chromosome pairing. This suggests that the formation of the allopolyploids could involve species more closely related than previously assumed. Despite the molecular affinity among the genomes, the meiotic pairing is probably controlled by specific genes that restrict homeologous pairing in polyploids.

López A; Fernández A; Poggio L

2010-08-01

107

Genomic affinities in Turnera (subseries Turnera, Turneraceae) inferred by in situ hybridization techniques.  

Science.gov (United States)

Subseries Turnera comprises a polyploid complex with ploidy levels ranging from diploid (2n = 2x = 10) to octoploid (2n = 8x = 40). The use of fluorescent in situ hybridization greatly improved the knowledge of the karyotypes of Turnera species by detecting and mapping rDNA sites. Interspecific variability in the number of sites was detected, but not in correlation with the ploidy level. A chromosome pair with a strong hybridization signal was always visible and this signal corresponded to the secondary constriction detectable by conventional techniques. Genomic in situ hybridization experiments combined with information on meiotic pairing in species and interspecific hybrids revealed that homologies detected by molecular analysis are greater than those detected by chromosome pairing. This suggests that the formation of the allopolyploids could involve species more closely related than previously assumed. Despite the molecular affinity among the genomes, the meiotic pairing is probably controlled by specific genes that restrict homeologous pairing in polyploids. PMID:20725146

López, Alicia; Fernández, Aveliano; Poggio, Lidia

2010-08-01

108

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

109

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

110

[In situ femoro-popliteal bypass grafts. Study of 85 cases using Cartier's technique  

UK PubMed Central (United Kingdom)

From January 1985 to december 1989, 83 patients (69 men, 14 women) underwent an in situ femoro-popliteal bypass using a semi-closed technique and the valvulotome developed by Dr Paul Cartier. Most patients (67%) were operated for severe ischemia while 33% were for claudication. HTA was present in 31% of patients, diabetes in 38% and CAD in 57%. Mean preoperative ABI was 0.33 +/- 0.20 and mean ankle pressure was 50 +/- 30 mm of Hg. Arteriographic popliteal run-off showed three vessels in 21 cases (25%), two vessels in 17 cases (20%) and one vessel in 38 cases (45%). Nine patients (10%) presented an isolated popliteal artery. Bypass was constructed below knee in 62 patients (73%) and above knee in 23 (27%). Five mortalities (5.8%) and two major complications (2.3%) were related to surgery. Four early graft failures (4.4%) were noted but 3 were successfully reoperated. Postoperative ABI was 0.71 +/- 0.23 mm of Hg and 81% of patients had complete relief of their symptoms. With a mean follow-up 19 months, graft patency was 91% +/- 6% and 84% +/- 11% at one and two years and was not influenced by operative indication: hypertension, diabetes, preoperative ABI, arteriographic findings or distal anastomotic site. Overall survival was 80% +/- 10% and 69 +/- 13 at one and two years. The in situ technique using the Cartier valvulotomes is an excellent operation and compares favourably with other techniques.

Chapleau D; Lassonde J; Blair JF; Laurendeau F

1991-01-01

111

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

Directory of Open Access Journals (Sweden)

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

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

2010-01-01

112

Fiber optic interrogator based on colorimetry technique for in-situ nitrate detection in groundwater  

Directory of Open Access Journals (Sweden)

Full Text Available Nitrate poisoning occurs when nitrite is absorbed into the blood, where it changes the red-colored blood pigment, called hemoglobin, to methemoglobin. Hemoglobin carries oxygen from the lungs to the other tissues, but methemoglobin cannot carry oxygen. Poisoning occurs when the methemoglobin concentration in the blood stream is so high that the oxygen carrying capacity of the blood is reduced to a critical level. Over the years nitrate contamination has acquired alarming proportions due to seepage of nitrates of fertilizers into the soil. Though several methods of monitoring nitrate concentration have been devised with some success, there is still a persistent need for devising easily deployable and in-situ techniques for monitoring nitrates in groundwater. Fiber optic techniques are capable of meeting these requirements, besides offering several other important advantages. Fiber optic nitrate detection sensors have thus become quite attractive and are currently being investigated to address the high costs associated with the existing nitrate concentration monitoring procedures. This paper describes fiber optic interrogator for in-situ nitrate detection in groundwater based on colorimetry technique.

Navneet Singh Aulakh; Rajinder Singh Kaler

2008-01-01

113

Development of an in-situ measurement technique for a PWSCC crack length determination  

Energy Technology Data Exchange (ETDEWEB)

Primary water stress corrosion cracking (PWSCC) in reactor pressure vessel head penetration nozzles, their welded parts, and steam generator tubes at pressurized water reactors have been found in many countries. Their failure mechanisms have not been fully understood up to now, however, a precise and nondestructive measurement of a crack length during PWSCC is recognized as a key parameter to properly assess the reliability/integrity of nuclear core components in primary water environments. To achieve this goal, an in-situ measurement technique was developed using the DCPD (direct current potential drop) method. In the present study, this system is described, and some results of the test are given.

Lim, Yun Soo; Kim, Hong Pyo; Hwang, Seong Sik; Lee, Han Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2008-05-15

114

Development of an in-situ measurement technique for a PWSCC crack length determination  

International Nuclear Information System (INIS)

Primary water stress corrosion cracking (PWSCC) in reactor pressure vessel head penetration nozzles, their welded parts, and steam generator tubes at pressurized water reactors have been found in many countries. Their failure mechanisms have not been fully understood up to now, however, a precise and nondestructive measurement of a crack length during PWSCC is recognized as a key parameter to properly assess the reliability/integrity of nuclear core components in primary water environments. To achieve this goal, an in-situ measurement technique was developed using the DCPD (direct current potential drop) method. In the present study, this system is described, and some results of the test are given.

2008-01-01

115

In situ stabilization of cadmium-, lead-, and zinc-contaminated soil using various amendments.  

UK PubMed Central (United Kingdom)

Chemical stabilization is an in situ remediation method that uses inexpensive amendments to reduce contaminant availability in polluted soil. We tested the effects of several amendments (limestone, red-mud, and furnace slag) on the extractability of heavy metals, microbial activities, phytoavailability of soil metals (assessed using lettuce, Lactuca sativa L.), and availability of heavy metals in ingested soil to the human gastrointestinal system (assessed using the physiologically based extraction test). The application of soil amendments significantly decreased the amount of soluble and extractable heavy metals in the soil (p<0.05). The decreased extractable metal content of soil was accompanied by increased microbial activity and decreased plant uptake of heavy metals. Soil microbial activities (soil respiration, urease, and dehydrogenase activity) significantly increased in limestone and red-mud-amended soils. Red-mud was the most effective treatment in decreasing heavy-metal concentrations in lettuce. Compared to non-amended control soil, lettuce uptake of Cd, Pb, and Zn was reduced 86%, 58%, and 73%, respectively, by the addition of red-mud.

Lee SH; Lee JS; Choi YJ; Kim JG

2009-11-01

116

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

117

Stability control in underground working adjacent an in situ oil shale retort  

Energy Technology Data Exchange (ETDEWEB)

In situ oil shale retorts are formed in spaced-apart rows, with adjacent rows of such retorts being separated by load-bearing inter-retort pillars of unfragmented formation sufficiently strong for preventing substantial subsidence. Each retort contains a fragmented permeable mass of formation particles containing oil shale. An air level drift is excavated in formation directly above the inter-retort pillar so that the roof and/or floor of the air level drift is spaced above the upper boundaries of the retorts in such adjacent rows. This causes the roof of the air level drift to be in compression, rather than in tension, which stabilizes the roof and avoids dangerous rock falls. During retorting operations, air is introduced at the upper edge of each retort through lateral air inlet passages sloping downwardly from the air level drift. Off gas and liquid products are withdrawn from each retort through a production level passage at the bottom of each report at the edge opposite the air inlet. The production level passages connect to a main production level drift extending between adjacent rows of retors. The roof of the main production level drift is excavated in fgormation directly below the inter-retort pillar so that the roof of of the production level drift is spaced below the lower boundaries of the retorts in adjacent rows. This places the roof of the production level drift in compression, avoiding the likelihood of rock falls.

Ricketts, Th. E.

1985-07-30

118

Advantage of In-situ over Ex-situ techniques as reliability tool: Aging kinetics of Imec's MCM-D discrete passives devices.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

An in-situ technique has been used to characterize Imec's MCM-D technology. This thin film technology dedicated to high frequency applications - uses exotic materials such as TaN and Ta2O5 for the resistors and the capacitors respectively. It was characterized at elevated temperature (up to 200degre...

Soussan, P; LEKENS, Geert; DREESEN, Raf; DE CEUNINCK, Ward; Beyne, E

119

A new adaptive power system stabilizer using a Lyapunov design technique  

Energy Technology Data Exchange (ETDEWEB)

A technique for designing an adaptive power system stabilizer is presented which improves the dynamic stability of power systems by effectively increasing the damping torque of the synchronous generator in the system. The proposed adaptive stabilizer is optimal in the sense of minimizing a specified performance condition. A characteristic feature of using a Lyapunov techniques is that it leads to stable adaptation loops. The dynamic responses following a step disturbance by digital simulations are obtained by means of three types of stabilizers: the conventional power system stabilizer, a frequency-response-based optimal adaptive stabilizer and the proposed Lyapunov stabilizer. Simulation results on a typical single-machine/infinite-bus system illustrate the superiority of the proposed technique. (author).

Ibrahim, O.A.-H.; Kamel, A.M. (Cairo Univ. (Egypt). Faculty of Engineering)

1990-04-01

120

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2000-03-31

 
 
 
 
121

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

122

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

International Nuclear Information System (INIS)

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

1976-03-29

123

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 excavator. The problem is formulated as a multi-objective optimization problem with the objective of maximizing  the supporting force for the test device. An 85 tons excavator is picked as the case to study. The first optimal results show the excavator may not support the test system successfully. After redesigning the boom and adding its weight and length as new parameters, the second optimize results indicate the test device can work normally.

Feilong Zheng; Liangcai Zeng; Gangsheng Kai

2013-01-01

124

The cultivation of yellow bamboo shoots of Phyllostachys heterocycla cv. pubescens and their in situ conservation technique  

UK PubMed Central (United Kingdom)

The yellow bamboo shoots of Phyllostachys heterocycla cv.pubescens are fleshy,tender,nutritious and delicious. Based on field investigations and trials,the cultivation of yellow bamboo shoots of Phyllostachys pubescens and their in situ conservation techniques were summarized and introduced in this paper. Using this technique,the emergence of the bamboo shoots can be postponed for 10--25 d .

Shi Quantai; Bai Ruihua

2005-01-01

125

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

Energy Technology Data Exchange (ETDEWEB)

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

Lekstrom, M; McLachlan, M A; Husain, S; McComb, D W; Shollock, B A [Imperial College London, Department of Materials, Exhibition Road, London, SW7 2AZ (United Kingdom)], E-mail: magnus.lekstrom@imperial.ac.uk

2008-08-15

126

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

International Nuclear Information System (INIS)

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

2008-01-01

127

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

UK PubMed Central (United Kingdom)

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.

Tomus D; Ng HP

2013-01-01

128

In-situ FTIR spectroscopy at the electrochemical interface: the interest of a modulation technique  

Science.gov (United States)

Infrared vibrational spectroscopy is increasingly being used as a tool for the in situ study of the electrochemical interface. The geometry may be that of external reflection with a thin- layer-electrolyte cell, or that of internal reflection in the case of infrared-transparent (e.g., semiconducting) electrodes. The small infrared absorption from the interfacial species can be separated out from the large electrolyte absorption background by making use of its specific dependence upon electrode potential. We describe an original technique combining audio- frequency modulation of the electrode potential, together with Fourier-transform infrared spectroscopy. This technique provides an unprecedented sensitivity of (Delta) I/I approximately 10-6 under typical operating conditions. It further allows a better identification of the species under study, by using the capability of probing the dynamics, inherent to a modulation technique. This allows one to differentiate between the different mechanisms that may lead to potential dependent changes at an electrochemical interface. The technique is illustrated by several applications: study of the ionic layer, interfacial species and their relation to electronic surface states at the n-Si/acetonitrile-electrolyte interface, study of the reversible reduction of solute species at a Ge/aqueous electrolyte interface, study of the catalytic mechanism of hydrogen evolution after this interface has been irreversibly modified by reduction of heteropolyanions.

Chazalviel, J. N.; Mandal, K. C.; Ozanam, F.

1992-03-01

129

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

Directory of Open Access Journals (Sweden)

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

Jeevanandham Arumugam; Thanushkodi Gowder Keppana

2009-01-01

130

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

DEFF Research Database (Denmark)

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

Kaiser, Andreas; Prasad, A.S.

2013-01-01

131

The use of x-ray techniques in the in situ study of corrosion  

Energy Technology Data Exchange (ETDEWEB)

Applications of x-ray absorption and fluorescence techniques for in situ chemistry studies of passivity and localized corrosion have been described. X-ray absorption near edge structures showed that rapidly grown oxides on aluminum-chromium alloys incorporated chromium in the oxide. Repeated electrochemically induced changes between the chromium 3- and 6-valent state occurred without chromium dissolving. When the oxide was grown by small potential steps, the chromium dissolved when 6-valent chromate was formed. With iron-chromium alloys, dissolution of chromate took place but 6-valent chromium was also incorporated in the oxide. The 6-valent state was reduced on exposing the iron alloy to air. X-ray fluorescence measurements, in conjunction with energy dispersive analysis, have been used to monitor iron, chromium and nickel concentrations in solution. The concentrations and concentration gradients during localized corrosion of stainless steel were used to determine salt solubility and relative diffusion rates.

Isaacs, H.S.

1992-12-31

132

Use of noninvasive geophysical techniques for the In Situ Vitrification Program  

Energy Technology Data Exchange (ETDEWEB)

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

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

1991-11-01

133

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1999-12-29

134

Using genetic techniques to quantify reinvasion, survival and in situ breeding rates during control operations.  

UK PubMed Central (United Kingdom)

Determining the origin of individuals caught during a control/eradication programme enables conservation managers to assess the reinvasion rates of their target species and evaluate the level of success of their control methods. We examine how genetic techniques can focus management by distinguishing between hypotheses of 'reinvasion' and 'survivor', and defining kin groups for invasive stoats (Mustela erminea) on Secretary Island, New Zealand. 205 stoats caught on the island were genotyped at 16 microsatellite loci, along with 40 stoats from the opposing mainland coast, and the age and sex were determined for each individual. Using these data, we compare and combine a variety of genetic techniques including genetic clustering, population assignment and kinship-based techniques to assess the origin of each stoat. The population history and individual movement could be described in fine detail, with results indicating that both in-situ survival and breeding, and reinvasion are occurring. Immigration to the island was found to be generally low, apart from in 1 year where around 8 stoats emigrated from the mainland. This increased immigration was probably linked to a stoat population spike on the mainland in that year, caused by a masting event of southern beech forest (Nothofagus sp.) and the subsequent rodent irruption. Our study provides an example of some of the ways genetic analyses can feed directly into informing management practices for invasive species.

Veale AJ; Edge KA; McMurtrie P; Fewster RM; Clout MN; Gleeson DM

2013-08-01

135

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

2013-08-27

136

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1980-12-01

137

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

International Nuclear Information System (INIS)

[en] 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

138

In-situ evaluation of compressed brick veneer using the flatjack technique  

Energy Technology Data Exchange (ETDEWEB)

The flatjack is a relatively nondestructive tool that allows engineers engaged in the repair and retrofit of masonry buildings (both historic and non-historic) to directly determine the in-situ state of compressive stress in masonry walls. The flatjack technique recently was used on a large modern apartment complex to quantify the compression in a brick veneer that was distressed and had questionable wind-load resistance. The compression in the veneer was due to a combination of concrete frame shrinkage and brick growth in a wall system that lacked horizontal control joints under the steel shelf angles. Although the compression caused spalling in the veneer, it also contributed beneficially to the walls' wind resistance. The amount of compression in the veneer was determined in several location throughout the height of one elevation of the building using flatjacks. The authors found that the compression in the veneer was greater than the flexural tension produced by design wind loads (including a reasonable factor of safety), but below the compressive strength of the brick masonry. This finding allowed a repair solution that was modest relative to strengthening the wall for inadequate wind resistance. Prior to employing the flatjack in the field, the authors conducted in-house research to check the accuracy and reliability of method, and develop their technique. The authors found that by altering gauge points from those locations prescribed by current ASTM standards to those recommended in recent research, greater accuracy could be obtained.

Bell, G.R.; Gabby, B.A.

1999-07-01

139

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

140

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

Science.gov (United States)

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

Mao, Bao-Hua; Liu, Chang-Hai; Gao, Xu; Chang, Rui; Liu, Zhi; Wang, Sui-Dong

2013-10-01

 
 
 
 
141

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

Energy Technology Data Exchange (ETDEWEB)

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

Bewlay, B.P.; Zhao, J.C.; Jackson, M.R.; Bishop, R.R.

1999-07-01

142

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 prepare...

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

143

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 prepare...

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

144

Intraocular lens centration and stability: efficacy of current technique and technology.  

UK PubMed Central (United Kingdom)

PURPOSE OF REVIEW: The manuscript presents a review of recently published studies analyzing different methodologies to assess centration and stability of intraocular lenses after implantation. RECENT FINDINGS: Considering that there is no current gold standard for centration and stability of intraocular lenses after implantation, we have summarized the different techniques used clinically for intraocular lenses centration and stability estimation. We have described the use of Scheimpflug imaging, the anterior segment optical coherence tomography and photography analysis used for lens position estimation. Techniques used to assess lens rotation are based on image analysis on digital retroillumination images. SUMMARY: Centration and stability of intraocular lenses are a matter of most importance and many methods have been developed. It seems that the best method for the assessment of lens position considers Scheimpflug imaging and for stability the use of retroillumination images.

Montés-Micó R; Cerviño A; Ferrer-Blasco T

2009-01-01

145

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

Directory of Open Access Journals (Sweden)

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

Paresh Rawat; Jyoti Singhai

2011-01-01

146

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

147

Practical risk assessment techniques for evaluating borehole stability  

Energy Technology Data Exchange (ETDEWEB)

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

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

2001-07-01

148

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

149

Identification of bacteria used for microbial enhanced oil recovery process by fluorescence in situ hybridization technique  

Energy Technology Data Exchange (ETDEWEB)

A fluorescence in situ hybridization (FISH) technique using 16S rRNA-targeted oligonucleotide probes was developed for rapid detection of microorganisms for use in the microbial enhancement of oil recovery (MEOR) process. Two microorganisms, Enterobacter cloacae TRC-322 and Bacillus licheniformis TRC-18-2-a, were selected from a collection of Enterobacter sp. and Bacillus sp. which were screened in previous studies as candidate microorganisms for injection, and were used for this experiment. Oligonucleotide probes, design based on specific sequences in the 16S rRNA gene were labeled with either fluorescein isothiocyanate (FITC), or 6-car-boxy-X-rhodamine (ROX), and were allowed to hybridize with fixed cells of the two microorganisms noted above. The fluorescence signal emitted from each microorganism cells could clearly be detected by an epifluorescence microscope. Moreover, E. cloacae TRC-322 and B, licheniformis TRC-18-2-a, suspended in actual reservoir brine, including inorganic salts, oil and aboriginal cells of the reservoir brine, could be detected directly by this hybridization method, without the need for cultivation and isolation. (author)

Fujiwara, K.; Tanaka, S.; Otsuka, M. [Kansai Research Institute, Kyoto (Japan). Lifescience Lab.; Yonebayashi, H. [Japan National Oil Corp., Chiba (Japan). Tech. Research Center; Enomoto, H. [Tohoku University, Sendai (Japan). Dept. of Geoscience and Tech.

2000-01-01

150

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

151

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

International Nuclear Information System (INIS)

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

1995-01-01

152

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

2012-10-11

153

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

UK PubMed Central (United Kingdom)

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.

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

2012-11-01

154

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1999-01-01

155

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1999-09-01

156

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1999-07-01

157

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; Nemati Zabihollah

2008-01-01

158

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

Energy Technology Data Exchange (ETDEWEB)

Spherical porous tin oxide was fabricated via a spray pyrolysis technique. TEM revealed that the primary SnO{sub 2} crystals had an average size of 5-10nm. Good interconnection between SnO{sub 2} crystals is also observed. The electrochemical measurements showed that the spherical porous SnO{sub 2} samples have excellent cyclability, which can deliver a reversible capacity of 410mAh/g for up to 50 cycles as a negative electrode for lithium batteries. Our approach for enhancing the structural stability of tin oxide is to incorporate spherical porous structures as a buffer zone to alleviate the volume expansion of the tin oxide anode during lithiation/delithiation. (author)

Yuan, L.; Guo, Z.P.; Konstantinov, K.; Wang, J.Z.; Liu, H.K. [Institute for Superconducting and Electronic Materials, University of Wollongong, NSW 2500 (Australia)

2006-05-05

159

In-situ contact electrical resistance technique for investigating corrosion inhibitor adsorption on copper electrodes  

Energy Technology Data Exchange (ETDEWEB)

Traditional electrochemical tests and the contact electrical resistance technique (CER) were used to investigate the effect on corrosion of pure copper (99.999 wt%) of adding benzotriazole (BTA) and 1-hydroxybenzotriazone (1-OH-BTA) to acidic solutions (sulfuric acid [H{sub 2}SO{sub 4}], pH = 1.7, and sodium sulfate [Na{sub 2}SO{sub 4}] until total sulfate [SO{sub 4}{sup 2{minus}}] concentration = 0.1 M). This technique permitted growth of oxide and/or salt films as well as adsorption of the organic inhibitors on the copper surface to be evaluated. Formation of copper oxide ([Cu{sub 2}O]{sub 2})., sulfate (CuSo{sub 4}{center_dot}5H{sub 2}O), thiocyanate (CuSCN), and halogenyde (CuI, CuBr, and CuCl) films on copper electrodes was followed in situ in sulfate solutions at various pH values under low overpotentials. Effects of pH, solution anion content, and/or the amount of BTA or 1-OH-BTA on electrical resistance (R) of the surface films formed on pure copper electrodes were treated. BTA acted as a more efficient corrosion inhibitor than 1-OH-BTA, reaching inhibition percentages (IP) of {approximately}90% compared to those of 1-OH-BTA, which reached a maximum of {approximately}76% in 2 {times} 10{sup {minus}3} M solutions. It was possible to distinguish between maximum R of the surface film, found in solutions containing BTA, associated with the adsorption of neutral inhibitor molecules, and the sharp rise in R attributable to [Cu(BTA)]{sub n} complex formation.

Moretti, G.; Quartarone, G.; Zingales, A. [Univ. of Venice (Italy). Dept. of Chemistry; Molokanov, V.V. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Physical Chemistry

1998-02-01

160

Microsurgical Technique for PICA-PICA In Situ Bypass: 3-D Operative Video.  

UK PubMed Central (United Kingdom)

Large and giant aneurysms involving the posterior inferior cerebellar artery (PICA) frequently have fusiform morphology, intraluminal thrombus, or wall calcification that prevents direct clipping and instead requires alternative occlusion techniques such as trapping and bypass. Vascular anatomy around the foramen magnum offers a variety of reconstructive techniques, including an in situ bypass that approximates the caudal loops of PICA with a side-to-side anastomosis. This bypass is entirely intracranial, does not require harvesting occipital artery, and temporary arterial occlusion is well tolerated.In this video, we show a 49-year-old woman with right-sided numbness and dizziness due to mass effect from a right giant, thrombotic PICA aneurysm. After exposing it through a far lateral approach and with direct clipping, the clip slid down the neck, occluding PICA and the parent vertebral artery. The clip was removed and PICA-PICA bypass was performed. The p3 PICA segments were mobilized together in the posterior midline. A side-to-side anastomosis with 10-0 running sutures was performed, sewing the deep walls from inside the lumen and then the superficial walls from outside the lumen. After bypass patency was confirmed with indocyanine-green videoangiography, the aneurysm was trapped and debulked. Postoperative angiography confirmed complete occlusion of the aneurysm, patency of the bypass, and retrograde filling of the right p1 and p2 segments. The patient made an excellent recovery and remains intact three months postoperatively. PICA-PICA bypass restores PICA flow with complex aneurysms that require deliberate occlusion of PICA with clipping or trapping, and is quicker than occipital artery-to-PICA bypass.

Rodríguez-Hernández A; Lawton MT

2013-07-01

 
 
 
 
161

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

UK PubMed Central (United Kingdom)

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

Halder A; Jain M; Chaudhary I

2013-01-01

162

Comparison of in situ and in vitro techniques for measuring ruminal degradation of animal by-product proteins.  

UK PubMed Central (United Kingdom)

Ruminally undegraded protein (RUP) values of blood meal (n = 2), hydrolyzed feather meal (n = 2), fish meal (n = 2), meat and bone meal, and soybean meal were estimated using an in situ method, an inhibitor in vitro method, and an inhibitor in vitro technique applying Michaelis-Menten saturation kinetics. Degradation rates for in situ and inhibitor in vitro methods were calculated by regression of the natural log of the proportion of crude protein (CP) remaining undegraded versus time. Nonlinear regression analysis of the integrated Michaelis-Menten equation was used to determine maximum velocity, the Michaelis constant, and degradation rate (the ratio of maximum velocity to the Michaelis constant). A ruminal passage rate of 0.06/h was assumed in the calculation of RUP. The in situ and inhibitor in vitro techniques yielded similar estimates of ruminal degradation. Mean RUP estimated for soybean meal, blood meal, hydrolyzed feather meal, fish meal, and meat and bone meal were, respectively, 28.6, 86.0, 77.4, 52.9, and 52.6% of CP by the in situ method and 26.4, 86.1, 76.0, 59.6, and 49.5% of CP by the inhibitor in vitro technique. The Michaelis-Menten inhibitor in vitro technique yielded more rapid CP degradation rates and decreased estimates of RUP. The inhibitor in vitro method required less time and labor than did the other two techniques to estimate the RUP values of animal by-product proteins. Results from in vitro incubations with pepsin.HCl suggested that low postruminal digestibility of hydrolyzed feather meal may impair its value as a source of RUP.

England ML; Broderick GA; Shaver RD; Combs DK

1997-11-01

163

Comparison of in situ and in vitro techniques for measuring ruminal degradation of animal by-product proteins.  

Science.gov (United States)

Ruminally undegraded protein (RUP) values of blood meal (n = 2), hydrolyzed feather meal (n = 2), fish meal (n = 2), meat and bone meal, and soybean meal were estimated using an in situ method, an inhibitor in vitro method, and an inhibitor in vitro technique applying Michaelis-Menten saturation kinetics. Degradation rates for in situ and inhibitor in vitro methods were calculated by regression of the natural log of the proportion of crude protein (CP) remaining undegraded versus time. Nonlinear regression analysis of the integrated Michaelis-Menten equation was used to determine maximum velocity, the Michaelis constant, and degradation rate (the ratio of maximum velocity to the Michaelis constant). A ruminal passage rate of 0.06/h was assumed in the calculation of RUP. The in situ and inhibitor in vitro techniques yielded similar estimates of ruminal degradation. Mean RUP estimated for soybean meal, blood meal, hydrolyzed feather meal, fish meal, and meat and bone meal were, respectively, 28.6, 86.0, 77.4, 52.9, and 52.6% of CP by the in situ method and 26.4, 86.1, 76.0, 59.6, and 49.5% of CP by the inhibitor in vitro technique. The Michaelis-Menten inhibitor in vitro technique yielded more rapid CP degradation rates and decreased estimates of RUP. The inhibitor in vitro method required less time and labor than did the other two techniques to estimate the RUP values of animal by-product proteins. Results from in vitro incubations with pepsin.HCl suggested that low postruminal digestibility of hydrolyzed feather meal may impair its value as a source of RUP. PMID:9406086

England, M L; Broderick, G A; Shaver, R D; Combs, D K

1997-11-01

164

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

Directory of Open Access Journals (Sweden)

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

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

2011-01-01

165

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; Taghizadeh Akbar; Janmohammadi Hossein; Moghadam G. Ali

2008-01-01

166

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2004-07-01

167

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

International Nuclear Information System (INIS)

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

2002-01-00

168

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

Scientific Electronic Library Online (English)

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

Rodríguez Martínez, Raúl

2011-12-01

169

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

Directory of Open Access Journals (Sweden)

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

Raúl Rodríguez Martínez

2011-01-01

170

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 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 presencia de S. agalactiae por la técnica de inmunoperoxidasa indirecta (IPI) y microbiología. Se obtuvo señal positiva en el interior de los granulomas con una especific (more) idad 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 techniques as indirect immunoperoxidase technique (IPI) and microbiology. Positive signal was obtained within the granulomas with specificity of 100%. The usefulness of the tiramide (more) 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.

Pulido, E. A; Iregui, C. A

2010-04-01

171

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).

Songsak CHUMPAWADEE; Kritapon SOMMART; Thevin VONGPRALUB; Virote PATTARAJINDA

2005-01-01

172

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2004-11-14

173

Application of Arma Technique For Operation Stability of RSG-Gas  

International Nuclear Information System (INIS)

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

2000-01-01

174

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 accumula...

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

175

Electrochemical and spectroscopic in situ techniques for the investigation of the phosphating of zinc coated steel  

International Nuclear Information System (INIS)

In this work spectroscopic and electrochemical techniques were developed for the investigation of surface treatments used in steel industry. ICP-atomic emission spectroscopy (ICP-AES), Raman spectroscopy and the Quartz crystal microbalance (QCM) were applied to the investigation of the kinetics of phosphating as well as the properties of phosphate layers. Phosphating of zinc coated steel leads to the formation of a crystalline layer consisting of zinc phosphate and is employed to enhance paint adhesion and corrosion protection. For the high reaction rates necessary in industrial production lines, oxidation agents are added to the phosphating bathes to accelerate the reaction. The oxidation agents provide an additional reduction reaction beside the hydrogen formation and therefore decrease the number of gas bubbles, which would block the zinc surface and reduce the rate of phosphating. With addition of H2O2 or nitrates the rate of layer formation is distinctly increased. In a combined experiment of ICP-AES with QCM and potential transients, it was shown that the presence of these accelerators in the phosphating bath increases the rate of zinc dissolution and hence leads to a faster formation of the phosphate layer. In under paint corrosion of painted, zinc coated steel phosphate layers are exposed to a highly alkaline environment. The stability of a phosphate layer against alkaline attack is therefore essential for its performance in corrosion protection. To enhance the alkaline stability Mn and Ni are added to modern phosphating bathes. The incorporation of these elements reduces the dissolution rate in 0.1 M NaOH proportional to their concentration in the phosphate layer. The dissolution of Zn, P, Mn and Ni was determined quantitatively with ICP-AES. Raman spectroscopy showed the formation of a Mn-hydroxide layer during alkaline attack, which protects the phosphate layer and reduces further dissolution. On basis of these results the reaction of phosphate layers with alkaline solution can be proposed as an ion-exchange of PO43- and OH- resulting in a mixed hydroxide consisting of Zn and Mn. The model of the reaction mechanism was confirmed by additional QCM experiments. (author)

2003-01-01

176

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

177

Mechanism of protein stabilization by trehalose during freeze-drying analyzed by in situ micro-raman spectroscopy.  

UK PubMed Central (United Kingdom)

Raman investigations were performed in situ during freeze-drying of two model proteins, lysozyme and chymotrypsinogen. The structures of proteins dissolved in 0-30?wt % solutions of trehalose in D2 O were monitored with the fingerprint (800-1800?cm(-1) ) spectrum, simultaneously with freezing, ice sublimation, and water desorption analyzed in the O-D stretching (2200-2700?cm(-1) ) region. In the absence of trehalose, the main changes were detected at the end of primary drying, and correspond to distortion and disordering of secondary structures. A stabilizing effect of trehalose was evidenced in primary and secondary drying stages. Raman images were calculated after freezing and primary drying, providing the distributions of trehalose, water, and protein which occur during the first two stages of the lyophilization cycle. Raman images show a slight heterogeneity in the degree of protein denaturation at the end of primary drying, in relation with the structure of the frozen product observed during freezing. The ability of trehalose to make the protein more rigid was determined as responsible for the protein stabilization during a lyophilization cycle.

Hedoux A; Paccou L; Achir S; Guinet Y

2013-08-01

178

Mechanism of protein stabilization by trehalose during freeze-drying analyzed by in situ micro-raman spectroscopy.  

Science.gov (United States)

Raman investigations were performed in situ during freeze-drying of two model proteins, lysozyme and chymotrypsinogen. The structures of proteins dissolved in 0-30?wt % solutions of trehalose in D2 O were monitored with the fingerprint (800-1800?cm(-1) ) spectrum, simultaneously with freezing, ice sublimation, and water desorption analyzed in the O-D stretching (2200-2700?cm(-1) ) region. In the absence of trehalose, the main changes were detected at the end of primary drying, and correspond to distortion and disordering of secondary structures. A stabilizing effect of trehalose was evidenced in primary and secondary drying stages. Raman images were calculated after freezing and primary drying, providing the distributions of trehalose, water, and protein which occur during the first two stages of the lyophilization cycle. Raman images show a slight heterogeneity in the degree of protein denaturation at the end of primary drying, in relation with the structure of the frozen product observed during freezing. The ability of trehalose to make the protein more rigid was determined as responsible for the protein stabilization during a lyophilization cycle. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 102:2484-2494, 2013. PMID:23754549

Hedoux, Alain; Paccou, Laurent; Achir, Samira; Guinet, Yannick

2013-06-10

179

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

International Nuclear Information System (INIS)

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

2011-01-01

180

Elucidation of structure and nature of the PdO-Pd transformation using in situ PDF and XAS techniques.  

Science.gov (United States)

The PdO-Pd phase transformation in a 4 wt% Pd/Al2O3 catalyst has been investigated using in situ X-ray absorption spectroscopy (XAS) and in situ X-ray total scattering (also known as high-energy X-ray diffraction) techniques. Both the partial and total pair distribution functions (PDF) from these respective techniques have been analysed in depth. New information from PDF analysis of total scattering data has been garnered using the differential PDF (d-PDF) approach where only correlations orginating from PdO and metallic Pd are extracted. This method circumvents problems encountered in characerising the catalytically active components due to the diffuse scattering from the disordered ?-Al2O3 support phase. Quantitative analysis of the palladium components within the catalyst allowed for the phase composition to be established at various temperatures. Above 850 °C it was found that PdO had converted to metallic Pd, however, the extent of reduction was of the order ca. 70% Pd metal and 30% PdO. Complementary in situ XANES and EXAFS were performed, with heating to high temperature and subsequent cooling in air, and the results of the analyses support the observations, that residual PdO is detected at elevated temperatures. Hysteresis in the transformation upon cooling is confirmed from XAS studies where reoxidation occurs below 680 °C. PMID:23657756

Keating, Jonathan; Sankar, Gopinathan; Hyde, Timothy I; Kohara, Shinji; Ohara, Koji

2013-05-08

 
 
 
 
181

Elucidation of structure and nature of the PdO-Pd transformation using in situ PDF and XAS techniques.  

UK PubMed Central (United Kingdom)

The PdO-Pd phase transformation in a 4 wt% Pd/Al2O3 catalyst has been investigated using in situ X-ray absorption spectroscopy (XAS) and in situ X-ray total scattering (also known as high-energy X-ray diffraction) techniques. Both the partial and total pair distribution functions (PDF) from these respective techniques have been analysed in depth. New information from PDF analysis of total scattering data has been garnered using the differential PDF (d-PDF) approach where only correlations orginating from PdO and metallic Pd are extracted. This method circumvents problems encountered in characerising the catalytically active components due to the diffuse scattering from the disordered ?-Al2O3 support phase. Quantitative analysis of the palladium components within the catalyst allowed for the phase composition to be established at various temperatures. Above 850 °C it was found that PdO had converted to metallic Pd, however, the extent of reduction was of the order ca. 70% Pd metal and 30% PdO. Complementary in situ XANES and EXAFS were performed, with heating to high temperature and subsequent cooling in air, and the results of the analyses support the observations, that residual PdO is detected at elevated temperatures. Hysteresis in the transformation upon cooling is confirmed from XAS studies where reoxidation occurs below 680 °C.

Keating J; Sankar G; Hyde TI; Kohara S; Ohara K

2013-06-01

182

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

Science.gov (United States)

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. PMID:19007824

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

2008-11-05

183

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2005-09-26

184

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

185

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.

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

2010-01-01

186

Stabilization of microorganisms for in situ degradation of toxic chemicals. Final report  

Energy Technology Data Exchange (ETDEWEB)

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

Crawford, R.L.; Ralston, D.R.

1993-05-01

187

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2002-07-01

188

Filtering Technique for Stabilization of Marching-on-in-Time Method  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, digital filters are used for the stabilization of the marching-on-in-time (MOT) method. A methodology of designing a proper filter using optimization techniques is proposed here. Since the proposed procedure considers the important part of the spectrum of the excitation signal, the designed filter does not degrade the accuracy of the MOT method. Further, the procedure for the efficient stabilization of the MOT method by a set of filters is proposed and verified on the examples.

J. Lacik

2010-01-01

189

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

Energy Technology Data Exchange (ETDEWEB)

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

Pagels, Joakim

2005-04-01

190

In situ direct-casting of alumina slurry stabilized with zirconium acetate using enzyme reaction  

Energy Technology Data Exchange (ETDEWEB)

A new direct-casting method on aqueous-acidic high solids loading alumina slurries stabilized with zirconium acetate (Zr-Ac) has been developed. The addition of Zr-Ac enhanced the dispersion and fluidity of 57 vol% alumina slurry at pH 4.3 on the wide concentration range, 10{sup -5} to 10{sup -3} M [Zr]. At pH > 4.3, the viscosity of alumina slurry with Zr-Ac increased slowly, and finally the slurry coagulates to change its properties from a viscous liquid to homogeneous, rigid, ceramic green body. The urease-catalyzed hydrolysis reaction of urea was used to increase the pH of the slurry, homogeneously and to form zirconium hydroxide to be act as a binder. We discussed how the direct-casting process was applied to our weakly acidic alumina slurry containing Zr-Ac. (orig.)

Sakurada, O.; Konishi, H.; Hashiba, M. [Gifu Univ. (Japan). Dept. of Applied Chemistry

2002-07-01

191

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

192

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

193

Neutron capture gamma-ray technique for in situ mineral analysis  

International Nuclear Information System (INIS)

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

1987-01-01

194

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

UK PubMed Central (United Kingdom)

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

Zhou X; Xu D; Zhang Q; Lu J; Zhang K

2013-08-01

195

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)

[en] 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

2007-01-01

196

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

197

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

Directory of Open Access Journals (Sweden)

Full Text Available Power system stability improvement by coordinated design of a Power System Stabilizer (PSS) and a Thyristor Controlled Series Compensator (TCSC) controller is addressed in this paper. Particle Swarm Optimization (PSO) technique is employed for optimization of the parameterconstrained nonlinear optimization problem implemented in a simulation environment. The proposed controllers are tested on a weakly connected power system. The non-linear simulation results are presented for wide range of loading conditions with various fault disturbances and fault clearing sequences as well as for various small disturbances. The eigenvalue analysis and simulation results show the effectiveness and robustness of proposed controllers to improve the stability performance of power system by efficient damping of low frequency oscillations under various disturbances.

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

2007-01-01

198

Studies of ferroelectric heterostructure thin films, interfaces, and device-related processes 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 device processes relevant to device development. We are using uniquely integrated time of flight ion scattering and recoil spectroscopy (TOF-ISARS) and spectroscopic ellipsometry (SE) techniques to perform in situ, real-time studies of film growth processes in the high background gas pressure required to growth ferroelectric thin films. TOF-ISARS provides information on surface processes, while SE permits the investigation of buried interfaces as they are being formed. Recent studies on SrBi{sub 2}Ta{sub 2}O{sub 9} (SBT) and Ba{sub x}Sr{sub 1{minus}x}TiO{sub 3} (BST) film growth and interface processes are discussed. Direct imaging of ferroelectric domains under applied electric fields can provide valuable information to understand domain dynamics in ferroelectric films. We discuss results of piezoresponse scanning force microscopy (SFM) imaging for nanoscale studies of polarization reversal and retention loss in Pb(Zr{sub x}Ti{sub 1{minus}x})O{sub 3} (PZT)-based capacitors. Another powerful technique suitable for in situ, real-time characterization of film growth processes and ferroelectric film-based device operation is based on synchrotrons X-ray scattering, which is currently being implemented at Argonne National Laboratory.

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

1999-06-29

199

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

International Nuclear Information System (INIS)

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

2005-01-01

200

In situ synthesis of lead sulfide nanoclusters on eggshell membrane fibers by an ambient bio-inspired technique  

Science.gov (United States)

An ambient aqueous soakage technique is successfully developed to prepare PbS nanoclusters on eggshell membrane (ESM) fibers containing some active functional groups (hydroxyl, amine, imine, etc). Based on the biomaterial ESM serving as the reactive substrate and some ESM biomacromolecules acting as the surfactant, PbS nanocrystallites are in situ formed and further assembled into well-distributed nanoparticle aggregations. This moderate bio-inspired strategy would be of great value in preparing novel functional nanomaterials. The as-prepared hybrid PbS/ESM nanocomposites could have great potential for applications in semiconductor industries, optoelectronic fields, and nanostructured devices.

Su, Huilan; Han, Jie; Wang, Na; Dong, Qun; Zhang, Di; Zhang, Chunfu

2008-02-01

 
 
 
 
201

In situ synthesis of lead sulfide nanoclusters on eggshell membrane fibers by an ambient bio-inspired technique  

International Nuclear Information System (INIS)

[en] An ambient aqueous soakage technique is successfully developed to prepare PbS nanoclusters on eggshell membrane (ESM) fibers containing some active functional groups (hydroxyl, amine, imine, etc). Based on the biomaterial ESM serving as the reactive substrate and some ESM biomacromolecules acting as the surfactant, PbS nanocrystallites are in situ formed and further assembled into well-distributed nanoparticle aggregations. This moderate bio-inspired strategy would be of great value in preparing novel functional nanomaterials. The as-prepared hybrid PbS/ESM nanocomposites could have great potential for applications in semiconductor industries, optoelectronic fields, and nanostructured devices

2008-01-01

202

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

Science.gov (United States)

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

Plati, Christina; Georgiou, Panos; Loizos, Andreas

2013-04-01

203

Anterior crucial ligament rupture: self-healing through dynamic intraligamentary stabilization technique.  

UK PubMed Central (United Kingdom)

PURPOSE: Surgery involving arthroscopic reconstruction of the injured ligament is the gold standard treatment for torn anterior cruciate ligament (ACL). Recent studies support the hypothesis of biological self-healing of ruptured ACL. The aim of the study is to evaluate, in an animal model, the efficacy of a new technique, dynamic intraligamentary stabilization that utilizes biological self-healing for repair of acute ACL ruptures. METHODS: The ACL in 11 adult female white alpine sheep was transected and in 8 sheep reconstructed by dynamic intraligamentary stabilization. To enhance the healing potential, microfracturing and collagen were used in all animals. The contralateral, non-operated knees served as controls. At 3 months postkilling, all animals were submitted to magnetic resonance imaging and biomechanical and histological evaluation. RESULTS: No surgery-related complications were observed. Postoperatively, all animals regularly used the operated leg with full weight bearing and no lameness. At the time of killing, all animals exhibited radiological and histological healing of the transacted ACL. Biomechanical tests confirmed successful restoration of anteroposterior translation in the dynamic intraligamentary stabilization knees. Histological examination revealed dense scar tissue at the ends of the transected ligaments exhibiting hypercellularity and hypervascularization. CONCLUSION: The dynamic intraligamentary stabilization technique successfully induced self-healing of ruptured ACL in a sheep model. Knee joints remained stable during the healing period allowing free range of motion and full weight bearing, and no signs of osteoarthritis or other intraarticular damage in the follow up were observed.

Kohl S; Evangelopoulos DS; Kohlhof H; Hartel M; Bonel H; Henle P; von Rechenberg B; Eggli S

2013-03-01

204

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

International Nuclear Information System (INIS)

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

2008-01-01

205

Application of Backstepping Techniques to the Time-varying Exponential Stabilization of Chained Form Systems  

UK PubMed Central (United Kingdom)

It is known that the kinematic model of several nonholonomic systems can be converted into a chained form control system. Asymptotical stabilization of any equilibrium point of this system cannot be achieved by means of a continuous pure state feedback, but can be obtained by using a time-varying continuous feedback [20]. In the present paper, a backstepping technique is used to derive explicit time-varying feedbacks that ensure exponential stability of the closed-loop system. Two classes of control laws are proposed, with one of them involving a dynamic extension of the original chained system. Like in other recent studies on the same topic, exponential convergence is obtained by using the properties associated with homogeneous systems. The control laws so obtained are continuous in both the state and time variables. A complementary and novel feature of the proposed control design technique lies in the estimation of a lower bound of the asymptotical rate of convergence as a function ...

Pascal Morin; Claude Samson; Programme Robotique; Projet Icare

206

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

UK PubMed Central (United Kingdom)

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

He F; Zhao D; Paul C

2010-04-01

207

State-of-the-art technique for power system stabilizer tuning  

Energy Technology Data Exchange (ETDEWEB)

Power System Stabilizers (PSS) have broad application throughout the world. PSS application requires careful tuning which is usually accomplished in the field with the generator and power system in an abnormal condition. Recently developed equipment which combines fast Fourier transform capability with digital computer technique provides a means of PSS tuning which is faster and more accurate than was previously obtainable. This paper describes a PSS tuning test conducted using the new technique. The advantages will be apparent to the reader. The described test is very poignant as evidenced by two unexpected occurrences of instability.

Farmer, R.G.; Agrawal, B.L.

1983-03-01

208

A new technique for stabilizing adolescent posteriorly displaced physeal medial clavicular fractures.  

UK PubMed Central (United Kingdom)

BACKGROUND: Adolescent posteriorly displaced physeal injuries of the medial clavicle are uncommon. Up to 50% of conservatively treated patients remain symptomatic, and late surgery is hazardous. Stability is rarely achieved with closed or open reduction alone, and internal fixation is usually required. Previously described options for fixation achieve stability of the medial clavicle by securing it to the intact epiphysis. Because the epiphyseal fragment is small, fixation is achieved using sutures or wires. This relies on the size and structural integrity of the medial fragment, which in our experience can be variable. We hypothesized that a novel technique of operative stabilization of these injuries, which does not require fixation to the epiphyseal fragment and uses no metalwork, is safe and effective in treating these injuries. MATERIALS AND METHODS: The operative technique involves suturing the medial clavicle to the anterior platysmal and periosteal layer using absorbable sutures passed through drill holes in the medial clavicle. Patients were assessed clinically an average of 9 months after surgery. RESULTS: We treated 7 patients with this method. There were no intraoperative complications. All patients were pain-free and symptom-free and had a full range of movement at follow-up. All patients had returned to their preinjury level of sports. CONCLUSIONS: We recommend this technique for treating these uncommon injuries. It is simple, safe, and reproducible and it produces good results.

Tennent TD; Pearse EO; Eastwood DM

2012-12-01

209

Complications of suture button ankle syndesmosis stabilization with modifications of surgical technique.  

UK PubMed Central (United Kingdom)

BACKGROUND: The TightRope® is a relatively new device designed to stabilize ankle syndesmotic injuries. There are no studies evaluating the clinical effectiveness of this technique and few reports addressing complications and potential modifications to the surgical technique reported in this article. MATERIALS AND METHODS: A retrospective review of 102 cases of traumatic ankle syndesmotic stabilization using the TightRope device is presented. Patients were followed up for a median of 85 days after surgery. RESULTS: Eight patients subsequently had the TightRope removed. This was performed for four reasons: osteomyelitis surrounding the implant, painful aseptic osteolysis surrounding the implant, failed stabilization of the syndesmosis, and unexplained pain. CONCLUSIONS: On the basis of experience, the authors recommend meticulous attention during the surgical technique. To prevent skin irritation and stitch abscess formation leading to osteomyelitis, the FiberWire loop is best cut with a knife at least 1 cm beyond the knot, allowing the sharp end of the FiberWire to lay flat adjacent to the fibula. Painful aseptic osteolytic reaction to the TightRope necessitates removal. To prevent rediastasis, a small medial incision is recommended for endobutton positioning directly abutting the tibial cortex without soft tissue interposition. Inserting the TightRope through a fibula plate prevents lateral button pull-through and rediastasis.

Storey P; Gadd RJ; Blundell C; Davies MB

2012-09-01

210

Evaluation of primary and secondary stability of titanium implants using different surgical techniques.  

UK PubMed Central (United Kingdom)

OBJECTIVE: To investigate the influence of different surgical techniques on the primary and secondary implant stability using trabecular bone of goats as an implantation model. MATERIAL AND METHODS: In the iliac crest of eight goats, 48 cylindrical-screw-type implants with a diameter of 4.2 mm (Dyna(®) ; Bergen op Zoom, the Netherlands) were installed, using three different surgical techniques: (i) 5% undersized, using a final drill diameter of 4 mm; (ii) 15% undersized, using a final drill diameter of 3.6 mm; and (iii) 25% undersized, using a final drill diameter of 3.2 mm. Peak insertion torque values were measured by a Digital(®) (MARK-10 Corporation, New York, NY, USA) torque gauge instrument during placement. At 3 weeks after implantation, removal torque was measured. Histomorphometrically, the peri-implant bone volume was measured in three zones; the inner zone (0-500 ?m), the middle zone (500-1000 ?m) and the outer zone (1000-1500 ?m). RESULTS: Evaluation of the obtained data demonstrated no statistically significant difference between different surgical techniques regarding removal torque values. With respect to the percentage peri-implant bone volume (%BV), also no significant difference could be observed between all three applied surgical techniques for both the inner, middle and outer zone. However, irrespective of the surgical technique, it was noticed that the %BV was significantly higher for the inner zone as compared to middle and outer zone (P < 0.05) around the implant. CONCLUSION: At 3 weeks after implant installation, independent of the used undersized surgical technique, the %BV in the inner zone (0-500 ?m) peri-implant area was improved due to both condensation of the surrounding bone as also the translocation of host bone particles along the implant surface. Surprisingly, no mechanical beneficial effect of the 25% undersized surgical technique could be observed as compared to the 5% or 15% undersized surgical technique to improve primary or secondary implant stability.

Tabassum A; Meijer GJ; Walboomers XF; Jansen JA

2013-05-01

211

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

DEFF Research Database (Denmark)

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

Saini, Vikram; Yvind, Kresten

2006-01-01

212

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 (AgNO3) 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 AgNO3 concentration. Furthermore, the catalytic activity of these Ag NPs was investigated by monitoring the reduction of p-nitrophenol (4-NP) by NaBH4. 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

213

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

UK PubMed Central (United Kingdom)

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.

Liang M; Yan M; Lu Y; Chen IS

2013-02-01

214

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

International Nuclear Information System (INIS)

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

2008-01-01

215

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

216

["In-situ Split" (ISS) Liver Resection: New Aspects of Technique and Indication.  

UK PubMed Central (United Kingdom)

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.

Lang SA; Loss M; Schlitt HJ

2013-09-01

217

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

Directory of Open Access Journals (Sweden)

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

Sang Jeen Hong; Jong Hwan Ahn; Won Taek Park; Gary S. May

2013-01-01

218

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

UK PubMed Central (United Kingdom)

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

Miliani C; Rosi F; Borgia I; Benedetti P; Brunetti BG; Sgamellotti A

2007-03-01

219

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

CERN Document Server

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

Stochino, Alberto; Adhikari, Rana X

2012-01-01

220

A win-win technique of stabilizing sand dune and purifying paper mill black-liquor.  

UK PubMed Central (United Kingdom)

The principle and technique were reported here to produce lignin-based sand stabilizing material (LSSM) using extracted lignin from black liquor of straw paper mills. Field tests using LSSM to stabilize and green sand dunes were started in 2002. The field experiment was carried out in August 2005 when the newly formed plant community was 3 years old. The results from the comprehensive field experiment demonstrated that unlike polyvinyl acetate or foamed asphalt commonly used for dune stabilization, LSSM was plant-friendly material and could be used in combination with seeding and planting of desert species. With the help of LSSM, the desert species (i.e., Agriophyllum squarrosum (L.) Moq. and Artemisia desertorum Spreng. etc.) could be used to form community in 2-3 yeas and to stabilize sand dune effectively. The newly formed community was sustainable under an extremely dry climate condition. The organic matter and total nitrogen in the soil increased significantly as the community were formed, while the change in P and K contents in the soil was negligible.

Hanjie W; Frits Pde V; Yongcan J

2009-01-01

 
 
 
 
221

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

UK PubMed Central (United Kingdom)

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.

Sivagurunathan A; Boy SC; Steenkamp G

2013-05-01

222

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

2013-05-28

223

In situ stabilization of trace metals in a copper-contaminated soil using P-spiked Linz-Donawitz slag.  

UK PubMed Central (United Kingdom)

PURPOSE: A former wood exploitation revealing high Cu and As concentration of the soils served as a case study for assisted phytoextraction. METHOD: P-spiked Linz-Donawitz (LD) slag was used as a soil additive to improve physico-chemical soil properties and in situ stabilize Cu and other trace metals in a sandy Cu-contaminated soil (630 mg kg?¹ soil). The LD slag was incorporated into the contaminated soil to consist four treatments: 0% (T1), 1% (T2), 2% (T3), and 4% (T4). A similar uncontaminated soil was used as a control (CTRL). After a 1-month reaction period, potted soils were used for a 2-week growth experiment with dwarf beans. RESULTS: Soil pH increased with the incorporation rate of LD slag. Similarly the soil electrical conductivity (EC, in millisiemens per centimetre) is ameliorated. Bean plants grown on the untreated soil (T1) showed a high phytotoxicity. All incorporation rates of LD slag increased the root and shoot dry weight yields compared to the T1. The foliar Ca concentration of beans was enhanced for all LD slag-amended soil, while the foliar Mg, K, and P concentrations were not increased. Foliar Cu, Zn, and Cr concentrations of beans decreased with the LD slag incorporation rate. CONCLUSIONS: P-spiked LD slag incorporation into polluted soil allow the bean growth and foliar Ca concentration, but also to reduce foliar Cu concentration below its upper critical value avoiding an excessive soil EC and Zn deficiency. This dual effect can be of interest for soil remediation at larger scale.

Negim O; Mench M; Bes C; Motelica-Heino M; Amin F; Huneau F; Le Coustumer P

2012-03-01

224

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

225

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

International Nuclear Information System (INIS)

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

2005-01-01

226

Investigation of synergy effects in selective oxidation catalysts through in situ laser Raman spectroscopy/isotopic labeling technique  

Energy Technology Data Exchange (ETDEWEB)

Previous studies over two-phase catalysts consisting of a simple molybdate (MnMoO{sub 4}, CdMoO{sub 4}) in close contact with molybdenum oxide (MoO{sub 3}) have shown the existence of a strong synergy effect in partial oxidation of C{sub 4} hydrocarbons to maleic anhydride. In this paper, the authors present results of the investigation of this synergy effect using an isotopic labeling technique coupled with in situ laser Raman spectroscopy. Results from these studies, when integrated with their previous work, provide complementary evidence for the catalytic job distribution of the two phases, in which the MoO{sub 3} phase incorporates its lattice oxygen into the hydrocarbon molecule, while the simple molybdate phase provides the oxygen necessary to regenerate MoO{sub 3} sites through an oxygen spillover mechanism. The in situ Raman spectroscopy experiments combined with structural specificity studies provide further clues about the catalytic sites responsible for selective versus complete oxidation.

Ozkan, U.S.; Smith, M.R.; Driscoll, S.A. (Ohio State Univ., Columbus (United States))

1992-03-01

227

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; M. Steinbacher; B. Buchmann

2012-01-01

228

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; M. Steinbacher; B. Buchmann

2012-01-01

229

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

230

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

231

A field test of electromagnetic geophysical techniques for locating simulated in situ mining leach solution  

Energy Technology Data Exchange (ETDEWEB)

The US Bureau of Mines, The University of Arizona, Sandia National Laboratories, and Zonge Engineering and Research Organization, Inc., conducted cooperative field tests of six electromagnetic (EM) geophysical methods to compare their effectiveness in locating a brine solution simulating in situ leach solution or a high-conductivity plume of contamination. The brine was approximately 160 m below the surface. The testsite was the University's San Xavier experimental mine near Tucson, AZ. Geophysical surveys using surface and surface-borehole, time-domain electromagnetic (TEM) induction; surface controlled-source audiofrequency magnetotellurics (CSAMT); surface-borehole, frequency-domain electromagnetic (FEM) induction; crosshole FEM; and surface magnetic field ellipticity were conducted before and during brine injection. The surface TEM data showed a broad decrease in resistivity. CSAMT measurements with the conventional orientation did not detect the brine, but measurements with another orientation indicated some decrease in resistivity. The surface-borehole and crosshole methods located a known fracture and other fracture zones inferred from borehole induction logs. Surface magnetic field ellipticity data showed a broad decrease in resistivity at depth following brine injection.

Tweeton, D.R.; Hanson, J.C.; Friedel, M.J.; Sternberg, B.K.; Dahl, L.J.

1994-01-01

232

Evaluation of in situ electrodeposition technique in electrothermal atomic absorption spectrometry.  

Science.gov (United States)

Conventional electrothermal atomic absorption spectrometric (ETAAS) equipment was extensively modified to enable automated in situ electrodeposition. The original autosampler injection Teflon capillary was replaced by a composite Pt/Teflon capillary which served as an anode in the electrodeposition circuit. Incorporation of a peristaltic pump and of a three-way solenoid under computer control into the sample dispenser circuit provided all necessary steps for automated electrodeposition-ETAAS determination. The automated sequence controlled addition of Pd modifier and of the analyte, electrolysis, withdrawal of spent electrolyte, rinsing, drying and atomization. Performance of the system was evaluated by analyzing Pb in 3% m/v NaCl. Optimization using factorial design yielded 3sigma detection limit of 20 pg Pb and reproducibility of 1.0-1.4% (for constant current electrodeposition), these values being superior to the results of conventional ETAAS of Pb in 0.5% m/v NaCl. Sensitivity of Pb determination is not affected by NaCl, NaOH, NaNO3 and NH4H2PO4, up to 4.6% m/v, demonstrating efficient matrix removal in the electrodeposition step. PMID:12705390

Krenzelok, Milan; Rychlovsky, Petr; Volny, Michael; Matousek, Jaroslav P

2003-03-01

233

Evaluation of in situ electrodeposition technique in electrothermal atomic absorption spectrometry.  

UK PubMed Central (United Kingdom)

Conventional electrothermal atomic absorption spectrometric (ETAAS) equipment was extensively modified to enable automated in situ electrodeposition. The original autosampler injection Teflon capillary was replaced by a composite Pt/Teflon capillary which served as an anode in the electrodeposition circuit. Incorporation of a peristaltic pump and of a three-way solenoid under computer control into the sample dispenser circuit provided all necessary steps for automated electrodeposition-ETAAS determination. The automated sequence controlled addition of Pd modifier and of the analyte, electrolysis, withdrawal of spent electrolyte, rinsing, drying and atomization. Performance of the system was evaluated by analyzing Pb in 3% m/v NaCl. Optimization using factorial design yielded 3sigma detection limit of 20 pg Pb and reproducibility of 1.0-1.4% (for constant current electrodeposition), these values being superior to the results of conventional ETAAS of Pb in 0.5% m/v NaCl. Sensitivity of Pb determination is not affected by NaCl, NaOH, NaNO3 and NH4H2PO4, up to 4.6% m/v, demonstrating efficient matrix removal in the electrodeposition step.

Krenzelok M; Rychlovsky P; Volny M; Matousek JP

2003-03-01

234

Application of fluorescence in situ hybridization technique to detect simazine-degrading bacteria in soil samples.  

Science.gov (United States)

We propose a new approach to evaluate the natural attenuation capacity of soil by using fluorescence in situ hybridization (FISH). A specific oligonucleotide probe AtzB1 was designed based on the sequence data of the atzB gene involved in the hydrolytic deamination of s-triazines; this gene, located in a multiple copy plasmid was detected by the optimized FISH protocol. Two agricultural soils (Lodi and Henares) with a history of simazine treatments, and two natural soils (Soto and Monza), without previous exposure to simazine, were studied. AtzB1 probe-target cells were found only in the agricultural soils and, in a greater percentage, in the Lodi soil, compared to the Henares one. Moreover, the greatest percentage of AtzB1 probe-target cells in Lodi was accompanied by a greater mineralization rate, compared to the Henares soil. The FISH method used in this study was suitable for the detection of simazine-degrading bacteria and could be a useful indicator of the potential of soil bioremediation. PMID:18082866

Martín, Margarita; Gibello, Alicia; Lobo, Carmen; Nande, Mar; Garbi, Carlos; Fajardo, Carmen; Barra-Caracciolo, Anna; Grenni, Paola; Martínez-Iñigo, M José

2007-12-20

235

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

236

Stability Evaluation Of Previous Volcanic Edifice Collapse At Pico De Orizaba Volcano, Mexico, Using Geotechnical Techniques  

Science.gov (United States)

Pico de Orizaba volcano has collapsed twice during its geologic evolution (Carrasco-Nuñez, 1997). The initial stage of evolution for this volcano is known as the Torrecillas cone that collapsed 0.21 Ma b.p., and the related deposits formed the Jamapa avalanche which traveled eastward 75 km. A second, superimposed constructional stage is the Espolón de Oro cone that also ended with a collapse 20 000 years b.p., forming the Tetelzingo avalanche-lahar that traveled 85 km. Samples from the remains of old summit cores and their corresponding collapse deposits were collected and tested in order to obtain strength parameters of altered rock from old volcanic edifices. Hydrothermal alteration and variations of strength of the two avalanche deposits were correlated with the strength values and alterations from the in situ corresponding sources. Strength values: Hoek and Brown's parameters, Uniaxial Compressive Strength (50-300 kPa), cohesion (480-2000 kPa), angle of friction (6° - 35° ); and degree of alteration give insights of rock mass quality and maximum intact rock strengths of the edifice rock mass. These values provide the upper limits for numerical model input parameter values for evaluation of flank stability. Rock strength from numerical model of previous failures can be compared with those obtained for the rock mass and intact rock of the actual edifice. This would permit the assessment of future avalanche hazards.

Concha-Dimas, A.; Watters, R. J.

2001-12-01

237

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

UK PubMed Central (United Kingdom)

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.

Nuzzio DB; Zettler ER; Aguilera A; Amaral-Zettler LA

2011-04-01

238

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1991-11-01

239

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)

2005-01-01

240

Lateral crural suspension flap: a novel technique to modify and stabilize the nasolabial angle.  

UK PubMed Central (United Kingdom)

The proper nasolabial angle is a determinant factor in achieving a pleasant result in esthetic rhinoplasty surgery. Nasal tip position depends on various interrelated elements. Its rotation should be analyzed by assessing the nasolabial angle. An increase in this angle results in an upward tilt of the base of the nose with a concomitant decrease in nasal length. Several methods have been advocated to improve this angle; unfortunately, these techniques have considerable limitations in modifying and stabilizing nasal tip rotation. The general principles for rotating the nasal tip include removing the factors that resist the rotation of the lower lateral cartilages, creating space to accommodate them, rotating the lower lateral cartilages into the desired position, and stabilizing the cartilages in the desired position. Resection of the cephalic margin of the lateral crura fulfills these goals. This report describes a straightforward and stable method that uses cephalic portions of the lower lateral crural cartilages as 2 flaps to suspend the nasal tip to the septum to modify and stabilize the nasolabial angle.

Bohluli B; Varedi P; Nazari S; Bagheri SC

2013-09-01

 
 
 
 
241

Lateral crural suspension flap: a novel technique to modify and stabilize the nasolabial angle.  

Science.gov (United States)

The proper nasolabial angle is a determinant factor in achieving a pleasant result in esthetic rhinoplasty surgery. Nasal tip position depends on various interrelated elements. Its rotation should be analyzed by assessing the nasolabial angle. An increase in this angle results in an upward tilt of the base of the nose with a concomitant decrease in nasal length. Several methods have been advocated to improve this angle; unfortunately, these techniques have considerable limitations in modifying and stabilizing nasal tip rotation. The general principles for rotating the nasal tip include removing the factors that resist the rotation of the lower lateral cartilages, creating space to accommodate them, rotating the lower lateral cartilages into the desired position, and stabilizing the cartilages in the desired position. Resection of the cephalic margin of the lateral crura fulfills these goals. This report describes a straightforward and stable method that uses cephalic portions of the lower lateral crural cartilages as 2 flaps to suspend the nasal tip to the septum to modify and stabilize the nasolabial angle. PMID:23769462

Bohluli, Behnam; Varedi, Payam; Nazari, Shahriar; Bagheri, Shahrokh C

2013-06-14

242

Characterization of Aequipecten opercularis (Bivalvia: Pectinidae) chromosomes by different staining techniques and fluorescent in situ hybridization.  

Science.gov (United States)

The chromosomes of the queen scallop Aequipecten opercularis were studied using conventional Giemsa staining, chromosome measurements, C-banding, silver staining, and fluorescent in situ hybridization (FISH) with 18S-28S rDNA and 5S rDNA probes. The karyotype (2n = 26) consists of large metacentric (pairs 1 and 2), telocentric (pairs 3, 4, 5, 6, 7, 8, and 9), and small metacentric chromosomes (pairs 10, 11, 12, and 13). The C-bands observed can be described as major and minor C-bands which are differentiated according to the intensity of the fluorescence and the frequency of the detection. Major C-bands were found on the long arm of the chromosome pairs 6, 7, 8, and 9 in an intercalary or subterminal position. Minor C-bands were located in the centromeric region in all chromosomes of the complement and also on one arm of pairs 12 and 13 in a terminal position. Silver spots were detected on the telomere of the long arms of one or two chromosomes of pair 7 in every case, although in two individuals up to four additional silver spots were detected. These were located on pairs 8 and 9 in the same position as the C-bands. 18S-28S ribosomal genes were found by FISH on the long arm of chromosome pair 7.5S ribosomal genes were located subterminally on one arm of metacentric pair 1, but two sites were differentiated in the case of elongated chromosomes. The results obtained allow for the identification of at least six different chromosome pairs in A. opercularis and contribute to the construction of an idiogram that is suitable for gene mapping and establishing accurate interspecific comparisons in scallops. PMID:9880917

Insua, A; López-Piñón, M J; Méndez, J

1998-08-01

243

Characterization of Aequipecten opercularis (Bivalvia: Pectinidae) chromosomes by different staining techniques and fluorescent in situ hybridization.  

UK PubMed Central (United Kingdom)

The chromosomes of the queen scallop Aequipecten opercularis were studied using conventional Giemsa staining, chromosome measurements, C-banding, silver staining, and fluorescent in situ hybridization (FISH) with 18S-28S rDNA and 5S rDNA probes. The karyotype (2n = 26) consists of large metacentric (pairs 1 and 2), telocentric (pairs 3, 4, 5, 6, 7, 8, and 9), and small metacentric chromosomes (pairs 10, 11, 12, and 13). The C-bands observed can be described as major and minor C-bands which are differentiated according to the intensity of the fluorescence and the frequency of the detection. Major C-bands were found on the long arm of the chromosome pairs 6, 7, 8, and 9 in an intercalary or subterminal position. Minor C-bands were located in the centromeric region in all chromosomes of the complement and also on one arm of pairs 12 and 13 in a terminal position. Silver spots were detected on the telomere of the long arms of one or two chromosomes of pair 7 in every case, although in two individuals up to four additional silver spots were detected. These were located on pairs 8 and 9 in the same position as the C-bands. 18S-28S ribosomal genes were found by FISH on the long arm of chromosome pair 7.5S ribosomal genes were located subterminally on one arm of metacentric pair 1, but two sites were differentiated in the case of elongated chromosomes. The results obtained allow for the identification of at least six different chromosome pairs in A. opercularis and contribute to the construction of an idiogram that is suitable for gene mapping and establishing accurate interspecific comparisons in scallops.

Insua A; López-Piñón MJ; Méndez J

1998-08-01

244

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

Energy Technology Data Exchange (ETDEWEB)

CSIRO - Exploration and Mining Division has developed a spectrometric nuclear techniques for in situ evaluation of coal and mineral deposits. Whilst the use of this technology is seen mainly in coal mining, it is becoming increasingly apparent in metalliferous mining. The logging tools developed by CSIRO are using the gamma-gamma, prompt neutron activation and spectrometric natural gamma techniques. The technology is used both in exploration and mine production for quality control. Nuclear borehole logging is complementary to the laboratory analysis of core samples retrieved from boreholes. Although it can not provide the same detailed information as the analysis of the core, the volume of rock sampled by nuclear borehole logging is much larger than the core samples and the results are provided almost instantaneously. Nuclear logging is particularly useful for mineral deposits where the core can not be fully recovered or in situations when not all the information provided by the analysis of the core is needed. Important savings can be made if the information required is acquired by logging open holes instead of drilling more expensive cored holes. The paper reviews various techniques developed by CSIRO - Exploration and Mining for both the coal and metalliferous mining industry. Emphasis is given to current research for developing logging tools equipped with ultra - low intensity gamma-ray sources (below 3.7 MBq activity). The tools are developed for both borehole logging and face analysis 17 refs., 7 figs.

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

1997-10-01

245

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

Science.gov (United States)

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

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

2011-06-01

246

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

UK PubMed Central (United Kingdom)

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

D'Lima DD; Chen PC; Kessler O; Hoenecke HR; Colwell CW Jr

2011-06-01

247

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

248

Monitoring the convergence and the stability of high-pressure gas storage cavities by echometric techniques  

Energy Technology Data Exchange (ETDEWEB)

To demonstrate the stability of high-pressure gas storage cavities and to monitor cavity convergence, a fully computerized echometric sonar technique was developed in the early eighties. Cavity surveys made by this technique at regular intervals in accordance with requirements imposed by mining authorities are necessary to monitor the stability of cavities as well as to predict cavity life and the effect of cavity convergence on the surface. Unlike conventional methods determining overall cavity closure, the new echometric sonar method allows the calculation of convergence as a function of depth by an intercomparison of data from different surveys. The first operation in the interpretation process is a numerical comparison of the data of vertical and horizontal cross-sections of two successive surveys. This operation will identify changes in the shape of a cavity which may occur if the cavity is leached in a steep-sloped salt dome. Following a verification of the computerized interpretation of the data, the volume of fall is calculated and cross-checked against the volume of rock deposited on the bottom of the cavity.

Denzau, H.; Erhardt, S.; Wierczeyco, E.

1988-01-01

249

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

250

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

International Nuclear Information System (INIS)

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

2001-01-01

251

Intracranial in situ side-to-side microvascular anastomosis: principles, operative technique, and applications.  

UK PubMed Central (United Kingdom)

OBJECTIVE: Side-to-Side microvascular anastomosis is a revascularization technique used to create an artificial conduit between two similar adjacent vessels. This technique is used for microsurgical clipping of aneurysms, when indicated. It is important to study the angiographic results, both immediate and long term, along with the clinical outcomes and indications of the procedure. METHODS: Fifteen patients who had this procedure over a fourteen-year period were reviewed for patency of bypass by intra-arterial digital subtraction angiography (DSA) and computed tomographic arteriograms (CTA) and their clinical outcomes were studied. The mean age of the study group was 53.4 years and mean angiographic follow up period was 14 months. RESULTS: All surviving patients (14 patients) had patent anastomosis with good clinical outcomes. None of the patients developed a clinically manifested stroke due to the procedure, while one had a small asymptomatic infarct detected post operatively. CONCLUSION: This technique is a useful and durable solution for correcting critical stenosis or complete occlusion of the vessels, while clipping intracranial aneurysms.

Ramanathan D; Hegazy A; Mukherjee SK; Sekhar LN

2010-04-01

252

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

UK PubMed Central (United Kingdom)

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

Martos Díaz P; Naval Gías L; Sastre Pérez J; González García R; Bances del Castillo F; Mancha de la Plata M; Galindo Moreno P; Muñoz Guerra M

2007-12-01

253

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

Scientific Electronic Library Online (English)

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

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

2007-11-01

254

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 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

2013-03-11

255

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

UK PubMed Central (United Kingdom)

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.

Buckner CD; Klopfenstein TJ; Rolfe KM; Griffin WA; Lamothe MJ; Watson AK; MacDonald JC; Schacht WH; Schroeder P

2013-06-01

256

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

International Nuclear Information System (INIS)

[en] 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)

2002-01-01

257

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; M. Haeckel; I. Klaucke; M. K. Ivanov; G. Bohrmann

2011-01-01

258

Wheat improvement for drought resistance and yield stability using mutation techniques  

International Nuclear Information System (INIS)

[en] 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)

2008-01-01

259

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

260

Electrochemical noise measurement: The definitive in-situ technique for corrosion applications?  

Energy Technology Data Exchange (ETDEWEB)

A review is presented of electrochemical noise (EN), the generic term given to fluctuations of current and potential seen in high-temperature corrosion, molten salt corrosion, and aqueous corrosion. EN levels in corrosion and particularly localized corrosion are significantly greater than EN observed in redox systems. EN associated with corrosion is the result of stochastic pulses of current generated by, for example, sudden film rupture, crack propagation, discrete events involving metal dissolution at etch pits, grain boundaries and kink sites, and hydrogen discharge with gas bubble formation and detachment. EN in corrosion includes low-frequency, nonstationary, and weakly stationary processes; transients; and cyclic or oscillatory phenomena. The use of EN, obtained either by potentiostatic/galvanostatic measurements or at freely corroding potentials, has been shown to offer advantages over conventional DC and AC techniques in research studies, testing, and corrosion monitoring. In many cases, reaction mechanisms can be elucidated and corrosion rate information can be obtained. Assessment of individual transients, use of signal analysis techniques, modeling of ensembles of transients as developed for electrocrystallization studies, and use of the chaos theory have all been used in EN evaluations.

Dawson, J.L. [CAPCIS Ltd., Manchester (United Kingdom)

1996-12-31

 
 
 
 
261

The microwave cavity perturbation technique for contact-free and in situ electrical conductivity measurements in catalysis and materials science.  

UK PubMed Central (United Kingdom)

We have developed a noncontact method to probe the electrical conductivity and complex permittivity of single and polycrystalline samples in a flow-through reactor in the temperature range of 20-500 °C and in various gas atmospheres. The method is based on the microwave cavity perturbation technique and allows the simultaneous measurement of microwave conductivity, permittivity and of the catalytic performance of heterogeneous catalysts without any need for contacting the sample with electrodes. The sensitivity of the method towards changes in bulk properties was proven by the investigation of characteristic first-order phase transitions of the ionic conductor rubidium nitrate in the temperature range between 20 and 320 °C, and by studying the temperature dependence of the complex permittivity and conductivity of a niobium(V)-doped vanadium-phosphorous-oxide catalyst for the selective oxidation of n-butane to maleic anhydride. Simultaneously, the catalytic performance was probed by on line GC analysis of evolving product gases making the technique a real in situ method enabling the noninvasive investigation of electronic structure-function relationships.

Eichelbaum M; Stösser R; Karpov A; Dobner CK; Rosowski F; Trunschke A; Schlögl R

2012-01-01

262

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

International Nuclear Information System (INIS)

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

2003-05-21

263

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

Energy Technology Data Exchange (ETDEWEB)

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

Lucero, V.; Meale, B.M.; Purser, F.E.

1990-01-01

264

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.

1995-01-01

265

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

Energy Technology Data Exchange (ETDEWEB)

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

Smith, Robert W.

2004-12-01

266

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

International Nuclear Information System (INIS)

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

2004-01-01

267

Emergency stabilization of the pelvic ring: Clinical comparison between three different techniques.  

UK PubMed Central (United Kingdom)

BACKGROUND: Emergency devices for pelvic ring stabilization include circumferential sheets, pelvic binders, and c-clamps. Our knowledge of the outcome of these techniques is currently based on limited information. METHODS: Using the dataset of the German Pelvic Trauma Registry, demographic and injury-associated characteristics as well as the outcome of pelvic fracture patients after sheet, binder, and c-clamp treatment was compared. Outcome parameters included transfusion requirement of packed red blood cells, length of hospital stay, mortality, and incidence of lethal pelvic bleeding. RESULTS: Two hundred seven of 6137 (3.4%) patients documented in the German Pelvic Trauma Registry between April 30th 2004 and January 19th 2012 were treated by sheets, binders, or c-clamps. In most cases, c-clamps (69%) were used, followed by sheets (16%), and binders (15%). The median age was significantly lower in patients treated with binders than in patients treated with sheets or c-clamps (26 vs. 47 vs. 42years, p=0.01). Sheet wrapping was associated with a significantly higher incidence of lethal pelvic bleeding compared to binder or c-clamp stabilization (23% vs. 4% vs. 8%). No significant differences between the study groups were found in sex, fracture type, blood haemoglobin concentration, arterial blood pressure, Injury Severity Score, the incidence of additional pelvic packing and arterial embolization, need of red blood cell transfusion, length of hospitalisation, and mortality. CONCLUSIONS: The data suggest that emergency stabilization of the pelvic ring by binders and c-clamps is associated with a lower incidence of lethal pelvic bleeding compared to sheet wrapping. LEVEL OF EVIDENCE: Level III.

Pizanis A; Pohlemann T; Burkhardt M; Aghayev E; Holstein JH

2013-08-01

268

Maxillary advancement in patients with severe maxillary hypoplasia: role of adjuvant stabilization techniques and materials.  

UK PubMed Central (United Kingdom)

BACKGROUND: Maxillary advancement in patients with orofacial clefts or craniofacial syndromes can be technically challenging. We present our experience with the use of adjunctive stabilization materials and techniques in patients undergoing single-stage maxillary advancements of more than 6.0 mm. METHODS: A retrospective review was performed of 25 patients who underwent maxillary advancements of more than 6 mm with the use of specially manufactured rigid fixation plates, allograft, tongue-and-groove locking osteotomies, and bone morphogenic protein. No patients had intermaxillary fixation or postoperative external stabilization. There were 19 patients with orofacial clefts and 6 with a craniofacial syndrome, 13 male and 12 female patients, aged from 14 to 60 years with a mean age of 19 years. Six cases represented secondary operations. The maxilla was advanced at a range of 6.0 to 17.0 mm, mean of 9 mm. All patients were followed up by the same orthodontist preoperatively and postoperatively. Patient charts were reviewed for complications, relapse, malunion, and nonunion. RESULTS: There was 1 complication requiring embolization for bleeding. Three patients (12%) developed velopharyngeal incompetence postoperatively. There was no evidence of relapse, malunion, or nonunion. No patients required a second advancement. CONCLUSIONS: The combination of specialized rigid fixation plates, allograft, tongue-and-groove locking osteotomies, and bone morphogenic protein was found to be safe and effective in preventing significant surgical relapse even after significant maxillary advancements.

Burstein FD; Maurice SM; Granger M; Williams JK

2012-05-01

269

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

270

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

Energy Technology Data Exchange (ETDEWEB)

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

Behringer, K.; Hennig, D

2002-11-01

271

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

272

An application of high-resolution crosshole seismic technique to detect roof stability problems  

Energy Technology Data Exchange (ETDEWEB)

A high-resolution seismic technique was applied in an underground trona mine in the state of Wyoming of the U.S.A. to detect roof stability problems. The roof condition was monitored through the crosshole seismic surveys at 1-month intervals during 120 days. The work consisted of measuring seismic velocity and roof deformation, observing boreholes and testing cores. Changes in seismic velocity, maximum amplitude of seismic waves were made into investigation. Results were analyzed using velocity tomograms, which were supported by borehole observations and core testing. A significant change in all dynamic properties was observed during the monitoring period. The seismic velocity was reduced by maximally 22 percents following a roof deformation of 160 mm. These changes were concluded to result from cracks, roof fracturing, and possibly stress release in the immediate roof. (author). 8 refs., 3 tabs., 7 figs.

Jung, Y.M. [Ajoo Geosystems Co., Seoul (Korea, Republic of); Maleki, H. [U.S. Bureau of Mines (United States)

1993-12-31

273

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

International Nuclear Information System (INIS)

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

274

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

UK PubMed Central (United Kingdom)

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

Geisler F

2013-07-01

275

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

Science.gov (United States)

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

Geisler, Fred

2013-07-01

276

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

UK PubMed Central (United Kingdom)

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

Elias CN; Rocha FA; Nascimento AL; Coelho PG

2012-12-01

277

Combined Microautoradiography–16S rRNA Probe Technique for Determination of Radioisotope Uptake by Specific Microbial Cell Types In Situ  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We propose a novel method for studying the function of specific microbial groups in situ. Since natural microbial communities are dynamic both in composition and in activities, we argue that the microbial “black box” should not be regarded as homogeneous. Our technique breaks down this black box wit...

Ouverney, Cleber C.; Fuhrman, Jed A.

278

In situ and laboratory assessment of heart rate in a Mediterranean limpet using a noninvasive technique.  

UK PubMed Central (United Kingdom)

Heart rate of the Mediterranean limpet Patella caerulea L. was investigated on the natural shore and in the laboratory by using a technique based on infrared phototransducers. Field recording occurred in the Gulf of Trieste (northern Adriatic) during March and June 1997. A consistent dependence of heart rate on temperature was observed in limpets both when submerged and when exposed to air in the two periods, but thermal acclimation was evident. During spontaneous activity at high tide, heart rate increased 1.5-1.7 times the values observed during resting in water at corresponding temperatures. The dependence of heart rate on temperature (10 degrees, 16 degrees, and 22 degrees C) and size (wet weight <1.25 and >1.30 g) in submerged limpets from different populations (northern Adriatic and Tyrrhenian) was tested in the laboratory by adopting a factorial design. The results showed a marked effect of temperature, body weight, and their interaction, independent from the site of origin. Smaller limpets showed a linear increase of heart rate in the whole range of temperature tests, while in the larger ones the increase between 10 degrees and 16 degrees C was greater than between 16 degrees and 22 degrees C. Heart rate decreased with increasing body size at control (16 degrees C) and high (22 degrees C) temperature, while at lower temperature (10 degrees C) no effect of body size was evident. When removed from their home scar, limpets increased heart rate to about 1.5 times the reference value. Finally, correlation of oxygen consumption with heart rate of submerged limpets maintained at a different temperature (10 degrees -22 degrees C) was statistically significant.

Santini G; De Pirro M; Chelazzi G

1999-03-01

279

An electronic brachytherapy technique for treating squamous cell carcinoma in situ of the digit: a case report.  

UK PubMed Central (United Kingdom)

BACKGROUND: Squamous cell carcinoma in situ of the digit presents a complex management problem, which is usually treated with surgery or radiation or topical agents. The outcome of the surgical treatment can be an undesirable cosmetic result and loss of function. We report a unique Electronic Brachytherapy technique to treat the digit, which uses a 50 Kv miniaturized X-ray source with specialized applicators. CASE PRESENTATION: A 62-year-old African-American male was presented with a 12-month history of gradual darkening of the dorsal-distal middle left finger. Examination revealed a hyper pigmented scaly patch on the proximal to lateral nail fold of the L 3rd finger, nail dystrophy, and vertical split in the lateral section of the nail. The patient underwent evaluation of the lesion by Plastic Surgery with the removal of the lateral nail and a nail bed biopsy. Pathology revealed squamous cell carcinoma in situ with a possible focal positive, deep margin. The patient deliberated over surgical opinions, and eventually decided on radiation. A high dose rate Electronic Brachytherapy system using the XOFT Accent controller delivered dose of 4000 cGy in eight fractions, twice weekly, with at least 48 hours between fractions and treatment prescribed to a depth of 0 to 2 mm. The Xoft unit has specialized skin applicators that permit superficial treatment. Parameters assessed included the efficacy, cosmetic results feasibility, and acute safety of the Electronic Brachytherapy technique. CONCLUSIONS: The patient exhibited moderate redness, hyperpigmentation erythema, desquamation, and Grade 1 to 2 edema acutely (following radiation), which resolved within 1 month of the treatment. Electronic brachytherapy treatment delivery took about 6 minutes, and the total procedure time was about 15 minutes. At the median follow-up of one year, the area revealed excellent cosmesis, and there was no infection or fat necrosis, desquamation, no cancer recurrence, and no evidence of fibrosis at the last follow-up. This suggests that Electronic Brachytherapy was a viable treatment option for this particular patient.

Arterbery VE; Watson AC

2013-04-01

280

Normal and Friction Stabilization Techniques for Interactive Rigid Body Constraint-based Contact Force Computations  

DEFF Research Database (Denmark)

We present a novel, yet simple, method for stabilization of normal forces. A normal stabilization term, carefully designed from hypotheses about interactive usability, is added to the contact force problem. Further, we propose friction stabilization as a completely new stabilization paradigm in interactive simulation. We present a comparison between our normal stabilization method and the Baumgarte stabilization method under extreme interactive conditions. Preliminary results on friction stabilization are presented, showing both the potential advantages of the method and that there is still work to be done.

Silcowitz, Morten; Niebe, Sarah Maria

2010-01-01

 
 
 
 
281

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

UK PubMed Central (United Kingdom)

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.

Minami H; Mizuta Y; Suzuki T

2013-01-01

282

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

283

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

284

Study of hydroformylation of formaldehyde in the presence of rhodium catalysts by in situ IR spectroscopy and the kinetic technique  

Energy Technology Data Exchange (ETDEWEB)

Carbonylrhodium complexes formed during hydroformylation of CH{sub 2}O from various rhodium precursors were investigated by in situ IR spectroscopy. It was found that under the conditions of the hydroformylation of CH{sub 2}O in N,N-dimethylacetamide (DMAA), RhH(CO)(PPh{sub 3}){sub 3}, RhCl(CO)(PPh{sub 3}){sub 2}, RhCl(PPh{sub 3}), RhCl(CO)(PBu{sub 3}){sub 2}, and (RhCl(CO){sub 2}){sub 2} form complex systems that necessarily contain anionic complexes, (Rh(CO){sub 2}L{sub x}(DMAA){sub y}){sup {minus}}(L=PPh{sub 3}, PBu{sub 3},x=1 to 2, y= 1 to 0; (Rh(CO){sub 4}){sup {minus}}). The participation of ionic structures in the hydroformylation of CH{sub 2}O, most likely, in the step of the activation of CH{sub 2}O, was proven by kinetic techniques.

Ezhova, N.N.; Korneeva, G.A.; Kurkin, V.I. [A.V. Topchiev Inst. of Petrochemical Synthesis, Moscow (Russian Federation)] [and others

1995-06-01

285

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

286

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

International Nuclear Information System (INIS)

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

2007-02-02

287

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; R. Hooshmand; M. Parastegari

2008-01-01

288

Experimental and mathematical simulation techniques for determining an in-situ response testing method for neutron sensors used in reactor power plant protection systems  

Energy Technology Data Exchange (ETDEWEB)

An analytical neutron sensor response model and methods for transient response measurements of neutron sensors (compensated ionization chamber), including possible in-situ techniques have been developed and evaluated to meet the provisions of Draft Standard ISA Sd67.06, IEEE 338-1977, and NRC Guide 1.118. One in-situ method requires the perturbation of the high voltage detector (sensor) power supply and measurement of the sensor response. The response to a perturbation of the power supply is related to the response of the sensor to a transient change in neutron flux. Random signal analysis is another in-situ technique to monitor the neutron sensor response. In this method the power spectrum of the inherent fluctuations from the neutron sensor output (current in CIC) are measured and evaluated. Transient response techniques (including in-situ methods) are experimentally and analytically evaluated to identify the mechanisms which may cause degradation in the response of the neutron sensors. The objective of the experimental evaluation was to correlate the measured response time using transient radiation flux changes and power supply perturbation. The objective of the analytical model of the different sensor response was to predict response time and degradation mechanisms.

Behbahani, A.

1983-01-01

289

A Novel Technique for Osteotome Internal Sinus Lifts with Simultaneous Placement of Tapered Implants to Improve Primary Stability.  

UK PubMed Central (United Kingdom)

Abstract Posterior maxilla is a challenging site for implant placement owing to anatomical limitations and inherent poor bone quality. Primary stability serves as a predictor of future osseointegration and different surgical techniques have been recommended to improve the stability. The case report describes a novel technique developed for implant placement simultaneous to internal sinus floor elevation. Divergent, concave tipped osteotomes in conjunction with intermediary osteotomes were used with tapered implants to internally elevate the sinus, to create the osteotomy for the simultaneous placement of tapered implant fixture. Using Osstell unit, high implant stability quotient values were recorded. This technique demonstrates the advantage of using osteotomes with tapered implants for lateral condensation to improve peri-implant bone density and to prevent implant entry in maxillary sinus due to macroscopic implant tapered design. Histological studies are needed to further support the theory.

Petrov SD; Xing Y; Khandelwal N; Drew HJ

2013-09-01

290

The effects of finishing and polishing techniques on surface roughness and color stability of nanocomposites.  

UK PubMed Central (United Kingdom)

OBJECTIVES: The aim of this in vitro study was to evaluate the effects of different finishing and polishing techniques on the surface roughness and color stability of nanocomposites. METHODS: Two nanohybrid (Grandio, Aelite Aesthetic Enamel), two nanofill (Filtek Supreme XT Dentin and Translucent), and a microhybrid (Filtek Z250) composites were used. Two hundred and eighty disc-shaped specimens were cured under a mylar strip. Seven specimens of each resin composite were randomly assigned to one of the seven polishing systems. A profilometer was used for assessing surface roughness. ?E was calculated with a colorimeter at baseline and 48 h after storage in a coffee solution. The results were analysed by two-way ANOVA and Tukey's HSD test (?=0.05). Regression analysis was used to examine the correlation between surface roughness and color stability (?=0.01). RESULTS: There was no significant difference in R(a) values between mylar strips and Sof-Lex polishing discs (p>0.05). The highest ?E and R(a) values were obtained from Grandio (p<0.05), and Aelite Aesthetic Enamel had the lowest ?E values (p<0.05). The Enhance system showed the lowest color differences among all the finishing systems. The highest ?E values were found in the composite resin groups under mylar strips and finished with diamond burs (p<0.05). CONCLUSIONS: While the Sof-Lex discs provided the lowest surface roughness, the Enhance Polishing system provided the most stain-resistant groups. Grandio presented the highest surface roughness and staining susceptibility after storage in coffee solution. Aelite Aesthetic Enamel, which did not include TEGDMA in its composition, showed the least discoloration. CLINICAL SIGNIFICANCE: The composites with smaller filler size did not necessarily show low surface roughness and discoloration. Staining of composite resins was dependent on monomer structure, as well as surface irregularities.

Gönülol N; Yilmaz F

2012-12-01

291

Experimental and mathematical simulation techniques for determining an in situ response testing method for neutron sensors used in reactor power plant protection systems  

Energy Technology Data Exchange (ETDEWEB)

An analytical neutron sensor response model and methods for measurement of neutron sensor (compensated ionization chamber) transient response have been developed and evaluated. In situ measurement methods to meet the provisions of the Instrument Society of America Draft Standard dS67.06, Institute of Electrical and Electronics Engineers 338-1977, and U.S. Nuclear Regulatory Commission Guide 1.118 are included. In one in situ method, the high-voltage sensor power supply is perturbed and subsequent sensor response measured. The response is analytically and experimentally related to the response of the sensor to a transient change in radiation flux. Random signal analysis was a second in situ technique evaluated to monitor the transient response of the neutron sensor. In this method the power spectrum of the inherent random fluctuations from the neutron sensor output is measured and analyzed.

Behbahani, A.; Miller, D.W.

1984-10-01

292

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

International Nuclear Information System (INIS)

[en] 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

293

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

UK PubMed Central (United Kingdom)

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

Gurwick NP; Moore LA; Kelly C; Elias P

2013-01-01

294

Improved stability of proteins immobilized in microparticles prepared by a modified emulsion polymerization technique.  

UK PubMed Central (United Kingdom)

Proteins can be immobilized in spherical microparticles of polyacrylamide gel (having a diameter of about 1 microgram) by an emulsion--polymerization technique. Higher cross-linked gels have a structure consisting of relatively large pores. This structure is advantageous when dealing with biologically active proteins acting on molecules dissolved in the surrounding medium. A rapid equilibrium is established between the interior of the particles and the medium, and rate-limiting diffusion is not observed. A suspension of carbonic anhydrase immobilized in microparticles will thus have kinetic properties very much like the free enzyme. In addition to the entrapment of the protein molecules in the three-dimensional network formed by the polyacrylamide threads, protein molecules are also fixed in the cross-linked threads of polyacrylamide. This fixation is probably responsible for the improved stability of the protein molecules against heat denaturation. Not even autoclaving at 110 degrees for 30 min denatured the immobilized enzyme completely (more than 25% of the enzyme activity was left). The higher resistance of molecules in microparticles against proteolytic degradation also is documented.

Ekman B; Sjöholm I

1978-05-01

295

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

Energy Technology Data Exchange (ETDEWEB)

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

Zhu, H. [Baoding Tianwei Solarfilms Co., Ltd., 071051 Baoding, Hebei Province (China); Jia, H., E-mail: jiahaijun@btw-solarfilms.com [Baoding Tianwei Solarfilms Co., Ltd., 071051 Baoding, Hebei Province (China); Liu, D.; Feng, Y.; Zhang, L.; Lai, B.; He, T.; Ma, Y.; Wang, Y.; Yin, J.; Huang, Y.; Mai, Y. [Baoding Tianwei Solarfilms Co., Ltd., 071051 Baoding, Hebei Province (China)

2012-06-01

296

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

UK PubMed Central (United Kingdom)

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.

Bozzini B; Tondo E; Prasciolu M; Amati M; Abyaneh MK; Gregoratti L; Kiskinova M

2011-08-01

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

2011-06-21

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.

1992-01-01

299

The use of oncoplastic reduction techniques to reconstruct partial mastectomy defects in women with ductal carcinoma in situ.  

UK PubMed Central (United Kingdom)

The application of oncoplastic techniques to breast conservation therapy (BCT) is thought to improve cosmetic results with some documented oncologic advantages in certain patients. Although present data highlight the oncologic safety of this approach, the role of oncoplastic surgery specific to ductal carcinoma in situ (DCIS) has not been elucidated. In this study, all women in the Emory Healthcare system between January 1991 and June 2006 with biopsy-proven DCIS who underwent lumpectomies combined with simultaneous reduction mammaplasties or mastopexies were identified. Medical records, including office notes, operative and pathology reports were analyzed. Parameters included age, BMI, histologic grade (low, intermediate, high) and type (comedo versus non-comedo) of DCIS, margin status, locoregional recurrence, specimen weight, postoperative complications, and overall outcomes. Pedicle design and contralateral breast pathology were also analyzed. Twenty-eight women were included in the study with an average age of 47. Therapeutic mammaplasty was the definitive procedure for 18 (64%) of these patients. Ten patients (36%) required reoperations: nine for positive margins and one for residual microcalcifications (stereo biopsy DCIS). Overall, seven patients (25%) required completion mastectomy with reconstruction (transverse rectus abdominus myocutaneous flap: n = 3, latissimus flap: n = 4), whereas three patients (11%) underwent re-excisions with confirmation of negative margins. All ten women who required completion mastectomy or re-excisions exhibited either intermediate or high-grade, comedo DCIS. Overall, 50% (6/12) of women diagnosed with high-grade comedo DCIS required completion mastectomy with reconstruction after initial therapeutic mammaplasty. The final positive-margin rate for women diagnosed with intermediate-grade, comedo necrosis was 43% (3/7). The women in this failed group that required reoperations were overall younger (mean: 45.6; median: 43) than those in which oncoplastic surgery was the definitive procedure (mean: 57.8; median: 57). There were no significant differences between the failed and successful groups in terms of biopsy weight (failed: 253 g, successful: 237 g), type of excision (e.g., wire-localized), location of tumor, reduction type (e.g., superior medial), or postoperative complications. There was one case of locoregional recurrence of DCIS 7 months after the initial operation. All 28 patients had no evidence of disease at an average follow-up of 2.7 years. This study suggests that although oncoplastic reduction techniques are a reasonable approach for women with DCIS, stricter patient selection and improved confirmation of negative margins will minimize the need for either re-excisions or completion mastectomy and reconstruction.

Song HM; Styblo TM; Carlson GW; Losken A

2010-03-01

300

Ultraviolet electroluminescence from nitrogen-doped ZnO-based heterojuntion light-emitting diodes prepared by remote plasma in situ atomic layer-doping technique.  

UK PubMed Central (United Kingdom)

Remote plasma in situ atomic layer doping technique was applied to prepare an n-type nitrogen-doped ZnO (n-ZnO:N) layer upon p-type magnesium-doped GaN (p-GaN:Mg) to fabricate the n-ZnO:N/p-GaN:Mg heterojuntion light-emitting diodes. The room-temperature electroluminescence exhibits a dominant ultraviolet peak at ? ? 370 nm from ZnO band-edge emission and suppressed luminescence from GaN, as a result of the decrease in electron concentration in ZnO and reduced electron injection from n-ZnO:N to p-GaN:Mg because of the nitrogen incorporation. The result indicates that the in situ atomic layer doping technique is an effective approach to tailoring the electrical properties of materials in device applications.

Chien JF; Liao HY; Yu SF; Lin RM; Shiojiri M; Shyue JJ; Chen MJ

2013-01-01

 
 
 
 
301

Ultraviolet electroluminescence from nitrogen-doped ZnO-based heterojuntion light-emitting diodes prepared by remote plasma in situ atomic layer-doping technique.  

Science.gov (United States)

Remote plasma in situ atomic layer doping technique was applied to prepare an n-type nitrogen-doped ZnO (n-ZnO:N) layer upon p-type magnesium-doped GaN (p-GaN:Mg) to fabricate the n-ZnO:N/p-GaN:Mg heterojuntion light-emitting diodes. The room-temperature electroluminescence exhibits a dominant ultraviolet peak at ? ? 370 nm from ZnO band-edge emission and suppressed luminescence from GaN, as a result of the decrease in electron concentration in ZnO and reduced electron injection from n-ZnO:N to p-GaN:Mg because of the nitrogen incorporation. The result indicates that the in situ atomic layer doping technique is an effective approach to tailoring the electrical properties of materials in device applications. PMID:23259506

Chien, Jui-Fen; Liao, Hua-Yang; Yu, Sheng-Fu; Lin, Ray-Ming; Shiojiri, Makoto; Shyue, Jing-Jong; Chen, Miin-Jang

2012-12-31

302

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

Energy Technology Data Exchange (ETDEWEB)

Studies on crisis stability, deterrence, and latency are presented in chronological order, which also reflects their logical order of development, captures the main features of stability analysis; relates first strike, crisis, and arms control stability as seen from US and Russian perspective; and addresses questions such as whether uncertainty in damage preference or defense deployment can be destabilizing. It illustrates the problems with alternative metrics, latency and reconstitution, and deep unilateral and proportional force reductions.

Canavan, G.H.

1997-12-01

303

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

Energy Technology Data Exchange (ETDEWEB)

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

Canavan, G.H.

1998-12-31

304

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

UK PubMed Central (United Kingdom)

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

Chamnanpood C; Sanguansermsri D; Pongcharoen S; Sanguansermsri P

2011-03-01

305

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

Science.gov (United States)

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

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

2011-03-01

306

Stabilizing dimensional changes in Si-based composite electrodes by controlling the electrode porosity: An in situ electrochemical dilatometric study  

International Nuclear Information System (INIS)

Highlights: ? A porosity-controllable Si-based composite electrode was fabricated. ? PMMA showing unzipping phenomena was utilized as a pore-forming agent. ? Cyclic dilation behavior was investigated with an in situ electrochemical dilatometry. ? PMMA-treated electrodes exhibited improved cycle performance. ? Control of electrode porosity by PMMA can be an effective way for Si-based electrodes. - Abstract: A porosity-controllable Si-based composite electrode was fabricated in the present study. Poly(methyl methacrylate) (PMMA), which possesses the unique thermal property of unzipping, was utilized as a pore-forming agent during electrode fabrication. PMMA-treated electrodes presented relatively low volume expansion and little deformation during lithiation. The cyclic dilation behavior of PMMA-treated electrodes was investigated by applying an in situ electrochemical dilatometric method, and enhanced dimensional reversibility during cycling was observed. The dilation behavior was closely related to the electrochemical performance, and PMMA-treated electrodes exhibited improved capacity retention and low impedance change during cycling. The newly generated pores in the PMMA-treated electrode can accommodate the volumetric expansion of Si-based active materials, which suppresses electrode deformation and the breakdown of the electrical network. The porosity plays an important role in Si-based electrodes. Thus, controlling the porosity through PMMA-treatment can be an effective way for the application of Si-based composite electrodes for advanced lithium-ion batteries.

2011-05-30

307

Stabilizing dimensional changes in Si-based composite electrodes by controlling the electrode porosity: An in situ electrochemical dilatometric study  

Energy Technology Data Exchange (ETDEWEB)

Highlights: > A porosity-controllable Si-based composite electrode was fabricated. > PMMA showing unzipping phenomena was utilized as a pore-forming agent. > Cyclic dilation behavior was investigated with an in situ electrochemical dilatometry. > PMMA-treated electrodes exhibited improved cycle performance. > Control of electrode porosity by PMMA can be an effective way for Si-based electrodes. - Abstract: A porosity-controllable Si-based composite electrode was fabricated in the present study. Poly(methyl methacrylate) (PMMA), which possesses the unique thermal property of unzipping, was utilized as a pore-forming agent during electrode fabrication. PMMA-treated electrodes presented relatively low volume expansion and little deformation during lithiation. The cyclic dilation behavior of PMMA-treated electrodes was investigated by applying an in situ electrochemical dilatometric method, and enhanced dimensional reversibility during cycling was observed. The dilation behavior was closely related to the electrochemical performance, and PMMA-treated electrodes exhibited improved capacity retention and low impedance change during cycling. The newly generated pores in the PMMA-treated electrode can accommodate the volumetric expansion of Si-based active materials, which suppresses electrode deformation and the breakdown of the electrical network. The porosity plays an important role in Si-based electrodes. Thus, controlling the porosity through PMMA-treatment can be an effective way for the application of Si-based composite electrodes for advanced lithium-ion batteries.

Jeong, Goojin [Green Energy System Center, Kumoh National Institute of Technology, Gumi, Gyeongbuk 730-701 (Korea, Republic of); Lee, Sang Min; Choi, Nam Soon [Battery Development Team, Samsung SDI Co., Ltd. Cheonan, Chungnam 330-300 (Korea, Republic of); Kim, Young-Ugk, E-mail: kyuang@snu.ac.kr [Battery Development Team, Samsung SDI Co., Ltd. Cheonan, Chungnam 330-300 (Korea, Republic of); Lee, Churl Kyoung [School of Advanced Materials and System Engineering, Kumoh National Institute of Technology, Gumi, Gyeongbuk, 730-701 (Korea, Republic of)

2011-05-30

308

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

UK PubMed Central (United Kingdom)

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

Wei YT; Wu SC; Yang SW; Che CH; Lien HL; Huang DH

2012-04-01

309

Study of phase stability in a class of binary alloys using augmented space recursion based orbital peeling technique  

International Nuclear Information System (INIS)

In this communication we have developed a recursion based approach to the study of phase stability and transition of binary alloys. We have combined the recursion method introduced by Haydock et al. [J. Phys. C: Solid State Phys. 5 (1972) 2845] and the our augmented space approach [A. Mookerjee, J. Phys. C: Solid State Phys. 6 (1973) 1340] with the orbital peeling technique proposed by Burke [Surf. Sci. 58 (1976) 349] to determine the small energy differences involved in the discussion of phase stability. We have studied three alloy systems: one which segregates and the other two orders at lower temperatures.

2008-11-30

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

2004-01-01

311

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

International Nuclear Information System (INIS)

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

2001-01-01

312

Experimental and Mathematical Simulation Techniques for Determining AN In-Situ Response Testing Method for Neutron Sensors Used in Reactor Power Plant Protection Systems.  

Science.gov (United States)

An analytical neutron sensor response model and methods for transient response measurements of neutron sensors (Compensated Ionization Chamber), including possible in-situ techniques have been developed and evaluated to meet the provisions of Draft Standard ISA Sd67.06, IEEE 338-1977, and NRC Guide 1.118. One in-situ method requires the perturbation of the high voltage detector (sensor) power supply and measurement of the sensor response. The response to a perturbation of the power supply is related to the response of the sensor to a transient change in neutron flux. Random signal analysis is another in-situ technique to monitor the neutron sensor response. In this method the power spectrum of the inherent fluctuations from the neutron sensor output (Current in CIC) are measured and evaluated. Transient response techniques (including in-situ methods) are experimentally and analytically evaluated to identify the mechanisms which may cause degradation in the response of the neutron sensors. Response time degradation was investigated through a change in sensor and signal cable response time in a predictable manner (through changes in the detector fill gas and use of a delay box for signal cable). Sensors and attached cables having different response times are evaluated using power supply perturbation, transient change in radiation flux (both x-ray and neutron flux), and analysis of the random signals from neutron sensors. The objective of the experimental evaluation was to correlate the measured response time using transient radiation flux changes and power supply perturbation. The objective of the analytical model of the different sensor response was to predict response time and degradation mechanisms. Completion of this work contributed to improved understanding, monitoring, and the response time verification of neutron sensors. As a consequence improved and safer nuclear power plant operation may be attained.

Behbahani, Alireza

313

Application of Precipitation Methods For The Production of Water-Insoluble Drug Nanocrystals: Production Techniques and Stability of Nanocrystals.  

UK PubMed Central (United Kingdom)

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 this 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 were also described in detail.

Xia D; Gan Y; Cui F

2013-05-01

314

"In-bone" utricle cultures--a simplified, atraumatic technique for in situ cultures of the adult mouse (Mus musculus) utricle.  

UK PubMed Central (United Kingdom)

HYPOTHESIS: The "in-bone" method of culturing utricles described here is a reliable and atraumatic technique for culturing mature mouse hair cells and studying hair cell death and protection. BACKGROUND: The current in vitro technique for studying hair cells of the mature mouse utricle involves removal from the temporal bone and free floating culture in media. This technique can be problematic because of variability in the preservation of the sensory epithelium and a steep learning curve that results in injury of the sensory epithelium in less experienced hands. We present a new atraumatic technique of culturing the utricle in situ within the temporal bone. METHODS: Leaving the temporal bone largely intact, a window is opened in the bony vestibule overlying the mouse utricle. The entire temporal bone is then placed into culture media. Utricles were cultured in situ for several days with minimal damage to the epithelium. The utricles are then fixed in situ, removed from the temporal bone, and processed. A standardized aminoglycoside-induced hair cell damage protocol was developed. RESULTS: Mature mouse utricles maintained hair cell numbers for 3 days in culture. Exposure to neomycin resulted in significant dose-dependent hair cell toxicity (p < 0.0001, 1-way analysis of variance). Exposure to the protective drug tacrine resulted in significant protection against neomycin (p < 0.05, 3-way analysis of variance). CONCLUSION: The "in-bone" technique is a reliable and atraumatic method for culturing mature mouse utricles and studying hair cell death and protection. It is easily mastered and can make in vitro study of hair cells accessible to more research groups.

Ou HC; Lin V; Rubel EW

2013-02-01

315

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

Energy Technology Data Exchange (ETDEWEB)

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

Saario, T.; Taehtinen, S.; Piippo, J.; Kukkonen, J.J.V.

1995-12-31

316

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

International Nuclear Information System (INIS)

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

2013-01-01

317

Fundamental Techniques for High Photon Energy Stability of a Modern Soft X-ray Beamline  

International Nuclear Information System (INIS)

High energy resolution and high energy stability are required for modern soft x-ray beamlines. Attempts at improving the energy stability are presented in this paper. Some measures have been adopted to avoid energy instability. It is clearly observed that the unstable temperature of the support frame of the optical elements results in photon energy instability. A photon energy stability of 10 meV for half a day is achieved by controlling the temperature with an accuracy of 0.01 deg. C.

2007-01-19

318

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

2008-01-01

319

Groundwater geochemical study at the Mizunami Underground Research Laboratory. Development of groundwater filtration techniques while maintaining in-situ hydrochemical conditions  

International Nuclear Information System (INIS)

In this report, we summarize groundwater filtration techniques developed and employed at the Mizunami Underground Research Laboratory. The methods are useful for the physical and chemical characterization of minute particles in contaminated groundwater (including organic and inorganic particles, microbes, etc.), which can effect migration behavior. It is also useful for investigating the adsorption and complexation of particles and elements in groundwater. We performed the filtration of groundwater on-site while maintaining in-situ pressure and anaerobic conditions and in the laboratory under controlled anaerobic conditions. The results indicate the viability of groundwater filtration under in situ geochemical conditions, if the filtration is performed at the controlled pressure and anaerobic conditions and with strict quality control. However, sample contamination occurs if stainless steel equipment is used. Therefore, we intend to develop Teflon equipment to avoid the contamination. (author)

2009-01-01

320

Comparison of the predictability, uniformity and stability of a laser in situ keratomileusis corneal flap created with a VisuMax femtosecond laser or a Moria microkeratome.  

Science.gov (United States)

This prospective study compared the predictability, uniformity and stability of laser in situ keratomileusis corneal flap thickness created by a femtosecond laser or a classic microkeratome. Twenty-five femtosecond laser (VisuMax, Carl Zeiss Meditec) flaps and 38 microkeratome (Moria M3) flaps were measured using anterior segment optical coherence tomography at 1 week, 1 month and 6 months postoperatively. Flap thickness at seven points on each of the four meridians was calculated. At 6 months, VisuMax flaps showed better prediction than Moria flaps for central flap thickness. The standard deviation within individual flaps was smaller for VisuMax flaps and their index of symmetry was better. The mean thicknesses among the four eccentricities in the VisuMax flaps were the same, while Moria flaps were thicker at the 3-mm radius compared with the centre. The VisuMax femtosecond laser created corneal flaps with better predictability and uniformity, and similar reproducibility and stability, compared with the microkeratome. PMID:21819705

Yao, P; Xu, Y; Zhou, X

2011-01-01

 
 
 
 
321

Comparison of the predictability, uniformity and stability of a laser in situ keratomileusis corneal flap created with a VisuMax femtosecond laser or a Moria microkeratome.  

UK PubMed Central (United Kingdom)

This prospective study compared the predictability, uniformity and stability of laser in situ keratomileusis corneal flap thickness created by a femtosecond laser or a classic microkeratome. Twenty-five femtosecond laser (VisuMax, Carl Zeiss Meditec) flaps and 38 microkeratome (Moria M3) flaps were measured using anterior segment optical coherence tomography at 1 week, 1 month and 6 months postoperatively. Flap thickness at seven points on each of the four meridians was calculated. At 6 months, VisuMax flaps showed better prediction than Moria flaps for central flap thickness. The standard deviation within individual flaps was smaller for VisuMax flaps and their index of symmetry was better. The mean thicknesses among the four eccentricities in the VisuMax flaps were the same, while Moria flaps were thicker at the 3-mm radius compared with the centre. The VisuMax femtosecond laser created corneal flaps with better predictability and uniformity, and similar reproducibility and stability, compared with the microkeratome.

Yao P; Xu Y; Zhou X

2011-01-01

322

Applications of exact linearization techniques for steady-state stability enhancement in a weak ac/dc system  

Energy Technology Data Exchange (ETDEWEB)

A nonlinear control strategy to improve the steady-state stability of a weak AC/DC power system is presented. The approach described in this paper is based on the extension of feedback linearization techniques to nonlinear descriptor system models. This method produces a nonlinear control strategy which is capable of enhancing system performance for various system operating conditions. This claim is supported with simulation results.

Kaprielian, S.; Clements, K. (Dept. of Electrical Engineering, Worcester Polytechnic Inst., Worcester, MA (US)); Turi, J. (Texas Univ., Richardson, TX (United States))

1992-05-01

323

A technique to stabilize record bases for Gothic arch tracings in patients with implant-retained complete dentures.  

UK PubMed Central (United Kingdom)

Clinicians have long expressed concern about the accuracy of the Gothic arch tracing for recording centric relation in edentulous patients. With the use of dental implants to assist in retaining complete dentures, the problem of inaccurate recordings, made for patients without natural teeth, can be significantly reduced. This article presents a technique that uses healing abutments to stabilize the record bases so that an accurate Gothic arch tracing can be made.

Raigrodski AJ; Sadan A; Carruth PL

1998-12-01

324

Orbital stability analysis in biomechanics: a systematic review of a nonlinear technique to detect instability of motor tasks.  

UK PubMed Central (United Kingdom)

Falls represent a heavy economic and clinical burden on society. The identification of individual chronic characteristics associated with falling is of fundamental importance for the clinicians; in particular, the stability of daily motor tasks is one of the main factors that the clinicians look for during assessment procedures. Various methods for the assessment of stability in human movement are present in literature, and methods coming from stability analysis of nonlinear dynamic systems applied to biomechanics recently showed promise. One of these techniques is orbital stability analysis via Floquet multipliers. This method allows to measure orbital stability of periodic nonlinear dynamic systems and it seems a promising approach for the definition of a reliable motor stability index, taking into account for the whole task cycle dynamics. Despite the premises, its use in the assessment of fall risk has been deemed controversial. The aim of this systematic review was therefore to provide a critical evaluation of the literature on the topic of applications of orbital stability analysis in biomechanics, with particular focus to methodologic aspects. Four electronic databases have been searched for articles relative to the topic; 23 articles were selected for review. Quality of the studies present in literature has been assessed with a customised quality assessment tool. Overall quality of the literature in the field was found to be high. The most critical aspect was found to be the lack of uniformity in the implementation of the analysis to biomechanical time series, particularly in the choice of state space and number of cycles to include in the analysis.

Riva F; Bisi MC; Stagni R

2013-01-01

325

Orbital stability analysis in biomechanics: a systematic review of a nonlinear technique to detect instability of motor tasks.  

Science.gov (United States)

Falls represent a heavy economic and clinical burden on society. The identification of individual chronic characteristics associated with falling is of fundamental importance for the clinicians; in particular, the stability of daily motor tasks is one of the main factors that the clinicians look for during assessment procedures. Various methods for the assessment of stability in human movement are present in literature, and methods coming from stability analysis of nonlinear dynamic systems applied to biomechanics recently showed promise. One of these techniques is orbital stability analysis via Floquet multipliers. This method allows to measure orbital stability of periodic nonlinear dynamic systems and it seems a promising approach for the definition of a reliable motor stability index, taking into account for the whole task cycle dynamics. Despite the premises, its use in the assessment of fall risk has been deemed controversial. The aim of this systematic review was therefore to provide a critical evaluation of the literature on the topic of applications of orbital stability analysis in biomechanics, with particular focus to methodologic aspects. Four electronic databases have been searched for articles relative to the topic; 23 articles were selected for review. Quality of the studies present in literature has been assessed with a customised quality assessment tool. Overall quality of the literature in the field was found to be high. The most critical aspect was found to be the lack of uniformity in the implementation of the analysis to biomechanical time series, particularly in the choice of state space and number of cycles to include in the analysis. PMID:22795784

Riva, F; Bisi, M C; Stagni, R

2012-07-13

326

COMPARISON OF CRESTAL BONE LOSS AND IMPLANT STABILITY AMONG IMPLANTS PLACED WITH CONVENTIONAL PROCEDURE AND USING OSTEOTOME TECHNIQUE: CLINICAL STUDY.  

UK PubMed Central (United Kingdom)

Abstract Purpose: To overcome the limitations of implant placement in Knife edge ridges, Summer introduced Osteotome technique in 1994. It has been claimed that bone condensing for preparation of the implant site in soft maxillary bone avoids the risk of heat generation and also implants can be placed precisely with increased primary stability. The purpose of this clinical study was to evaluate the crestal bone loss exhibited by the bone around early non-functionally loaded implants placed with conventional implant placement technique and with Summer's Osteotome technique, and also to evaluate whether bone compression technique provides better primary stability than conventional technique. Materials and Methods: A total of 10 Uniti implants were placed in the maxillary anterior region of 5 patients. One implant site was prepared by the conventional technique with drills (Control group A) and second site was prepared with the Osteotome technique (Experimental group B) using MIS bone compression kit. Resonance frequency measurements (RFMs) were made on each implant at the time of fixture placement and on the 180th day after implant fixture placement. The peri-implant alveolar bone loss was evaluated radiographically. Differences between the alveolar crest and the implant shoulder in radiographs were obtained immediately after implant insertion and on 180th day after implant placement. Results: RFMs demonstrated a significant higher stability of implants in the control group A than in the experimental group B on the day of surgery (p=0.026). However, no statistically significant difference in stability was found between both groups on 180th day after implant placement (p=0.076). Significant difference was found in the crestal bone levels after 180 days of surgery between two groups (p=0) with less crestal bone loss with group A. Conclusion: With in the limitations of this study we concluded that the Osteotome technique is good for the purpose it was introduced i.e. for Knife edge ridges and it should not be considered as a substitute for conventional procedure for implant placement.

Padmanabhan TV; Gupta R

2010-06-01

327

Methodological considerations of existing techniques for determining stabilization times following a multi-planar transition.  

UK PubMed Central (United Kingdom)

Postural stabilization is required following perturbations or after transitioning to standing. The current research evaluated two available algorithms that utilize within-trial data to quantify standing following multi-planar transitions. Forty-five participants began each trial by assuming a static forward kneeling posture that ended with an auditory signal prompting transition to standing. Data from two force plates was collected at 100Hz for 20s starting with the transition. With one algorithm, using windows of various lengths, stabilization time was defined as when mean center of pressure (CoP) velocity of the current window was less than that for the mean of all subsequent windows. This algorithm produced significantly different stabilization times (1.3-6.9s) depending on the window length. In a second algorithm, a negative exponential mathematical model was fit to data within each trial (R(2)=0.93). This approach was easily implemented and produced results (mean=2.1s) with lower variability (SD=0.9s). Though approaches exist that adequately determine stabilization times in well-constrained uni-planar movements, there are limitations to generalizability. The negative exponential mathematical model evaluated in this study provides a promising method for systematically determining stabilization times for multi-planar movements.

DiDomenico A; McGorry RW; Banks JJ

2013-07-01

328

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

Directory of Open Access Journals (Sweden)

Full Text Available In this study, two fresh culture multistrains were produced and tested on corn silage; homofermentative and hetrofermentative from commercially and laboratory produced inoculants. Chemical properties and characteristics of silage samples were determined in mini- silos for 7, 14, 28, 45 and 90 days (triplicate per treatment). In situ ruminal degradability of DM and CP and in vitro gas production of fresh forage and silage (45 and 90 day silage) were investigated. There were differences between treatments for DM, OM, CP and Ash contents. Residual WSC and CP contents decreased and the concentration of NH3-N increased with time post ensiling. Corn silage inoculated with the homofermentative inoculant had the lowest pH in all ensiling times except that of 28 days. Inoculated corn silage had lower pH than untreated corn silage at all ensiling times. Although, inoculation of corn silage significantly affected ruminal degradability of DM, but ruminal CP degradability was not influenced. Inoculation of corn silage had a significant effect on gas production from the corn silage. It was concluded that inoculation of corn silage improved ensiling characteristics; however the fresh culture inoculant did not have a remarkable effect compared with the commercially produced inoculant.

Bayatkouhsar et al.

2012-01-01

329

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

330

Development of advanced in-situ techniques for chemistry monitoring and corrosion mitigation in SCWO environments. 1998 annual progress report  

Energy Technology Data Exchange (ETDEWEB)

'This report evaluates the two years results of the research on the development of advanced electrochemical techniques for use in supercritical water oxidation (SCWO) environments. The SCWO technology was found to be a promising approach to treat a variety of hazardous wastes. However, the corrosion processes in the SCWO reactors is still a problem for further development of this technology. The authors have developed a flow-through electrochemical cell (FTEC) which allows us to monitor the corrosion process in real time at temperatures up to 500 C and pressures up to 400 bar. The FTEC consists of a flow-through Ag/AgCl external pressure-balanced reference electrode, a flow-through platinum hydrogen electrode, an yttria-stabilized zirconia pH sensor and an electrochemical noise sensor. The new FTEC has been designed to serve as a measurement vessel for the high temperature and high pressure circulation once-through flow loop and titanium alloy was chosen as the construction material. The FTEC, shown schematically in Figure 1, is used for the experiments. Two HPLC pumps are employed in the system, one for pumping the reaction solution through the loop and the other for pumping the reference solution through the reference electrode. The system pressure is sustained as a constant via a back pressure regulator. The temperature was measured using a thermocouple installed at the center of the FTEC. Because many physico-chemical processes, including corrosion, are sensitive to the pH, the measurement and control of pH is very important for the high temperature SCWO environment. The authors have measured the potentials of the FTEC for several HCl(aq) + NaCl(aq) solutions of different concentrations of HCl(aq) and derived the corresponding pH differences ({Delta}pH) over a wide range of temperatures at pressure around 350 bar. Comparison of the experimentally derived and theoretically calculated DpH values presented in Figure 2 clearly demonstrates the ability to measure pH with a high accuracy (better than \\2610.05 pH units). This result also shows the viability of the developed FTEC as a versatile potentiometric system for use at supercritical temperatures. During the next year of the project they will address the problem of electrochemical noise measurements and monitoring corrosion processes that occur on metallic materials exposed to super critical water.'

Macdonald, D.D.; Engelhardt, G. [Pennsylvania State Univ., University Park, PA (US); Garcia, K.M. [Idaho National Engineering and Environmental Lab., Idaho Falls, ID (US)

1998-06-01

331

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.

Hamid Reza Gharehshekhlou; Behrouz Rasouli; Ali Ahmad Ghotbi; Bahram Amiri

2012-01-01

332

Airborne observations of aerosol extinction by in situ and remote-sensing techniques: Evaluation of particle hygroscopicity  

Science.gov (United States)

Extensive profiling of aerosol optical, chemical, and microphysical properties was performed in the Washington DC/Baltimore MD region in July 2011 during NASA DISCOVER-AQ. In situ extinction coefficient (?ext,in-situ) measurements were made aboard the NASA P3-B aircraft coincident with remote-sensing observations by the High-Spectral Resolution Lidar (HSRL; ?ext,HSRL) aboard the NASA UC-12 aircraft. A statistical comparison revealed good agreement within instrumental uncertainty (?ext,in-situ = 1.1 ?ext,HSRL - 3.2 Mm-1, r2 = 0.88) and demonstrated the robust nature of hygroscopicity measurements (f(RH)) necessary to correct observations at dry relative humidity (RH) to ambient conditions. The average liquid-water contribution to ambient visible-light extinction was as much as 43% in this urban region. f(RH) values were observed to vary significantly from 1.1 to 2.1 on a day-to-day basis suggesting influence from both local and transported sources. Results emphasize the importance of accounting for the RH dependence of optical- and mass-based aerosol air-quality measurements (e.g., of PM2.5), especially in relation to satellite and remote-sensing retrievals.

Ziemba, Luke D.; Lee Thornhill, K.; Ferrare, Rich; Barrick, John; Beyersdorf, Andreas J.; Chen, Gao; Crumeyrolle, Suzanne N.; Hair, John; Hostetler, Chris; Hudgins, Charlie; Obland, Michael; Rogers, Raymond; Scarino, Amy Jo; Winstead, Edward L.; Anderson, Bruce E.

2013-01-01

333

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

International Nuclear Information System (INIS)

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

2006-06-15

334

[Destruction of the valve of the great saphenous vein in the technique of femoro-popliteal bypass in situ (author's transl)  

UK PubMed Central (United Kingdom)

Destruction of the valves of the great saphenous vein is one of the essential steps in femoro-popliteal bypass in situ. The authors suggest the use of bougies with a tip in the form a shell, the base of which is adorned with 4 rounded and smoothed teeth. After destruction of the great saphenous and ligation of the collaterals, arterial filling of the vein after superior anastomosis and the retrograde insertion of strippers may be used the collapse the valves opened by the blood flow. Amongst 40 bypasses performed using this technique, 38 were without problem.

Chevalier JM; Enon B; Pillet J

1980-01-01

335

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

336

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

Directory of Open Access Journals (Sweden)

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

S.Radha Krishna Reddy; JBV Subrahmanyam; A. Srinivasula Reddy

2013-01-01

337

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

Energy Technology Data Exchange (ETDEWEB)

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

Saario, T.; Taehtinen, S.

1995-09-01

338

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 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(more) n el rumen fue de 0.997 (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(more) ppeared from the duodenal bags in the lower digestive tract when samples were not incubated in the rumen. Carotenoids disappearance in small intestine was lower in the samples incubated in rumen. These results show an availability of 70.0% in carotenoids into the total digestive tract. In conclusion, the AS has a high availability in the degradation of total carotenoids in the digestive tract of ruminants.

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

2011-12-01

339

Interactions between flaxseed gums and WPI-stabilized emulsion droplets assessed in situ using diffusing wave spectroscopy.  

UK PubMed Central (United Kingdom)

Diffusing wave spectroscopy (DWS) was used to investigate the behavior of flaxseed gums when added to WPI-stabilized emulsions. The effect of different concentrations (0-0.33% (w/v)) of flaxseed gum, derived from two seed varieties, namely Emerson and McDuff, was studied at acidic and neutral pH. At pH 7.0 and low gum concentrations the dynamic and spatial characteristics of the system remained unchanged. While at gum concentrations from 0.075% to 0.20% a rapid phase separation was observed, at higher concentrations phase separation was retarded because of the increased background viscosity slowing down the mobility of the emulsion droplets. At pH 3.5, the difference in overall electrical charge between the gum (negative) and the protein on the emulsion surface (positive) led to electrostatic interactions. While at low concentration of flaxseed gum the general characteristics of the emulsions were not significantly different, at intermediate concentrations, bridging flocculation occurred. When sufficient flaxseed gum was present, the emulsion droplets mobility was arrested in a gel-like state. In spite of the compositional differences in the ratio of acidic and neutral fraction between the two polysaccharides extracted from different seed varieties, at both values of pH the behavior of the emulsions after addition of the polysaccharide was comparable.

Khalloufi S; Corredig M; Alexander M

2009-02-01

340

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

International Nuclear Information System (INIS)

Various natural and anthropogenic processes influence heavy metal concentrations within estuaries. In situ, time-integrated DGT measurements made over concurrent tidal phases found significantly higher concentrations of Cu (probability p = 0.017), Zn (p = 0.003) and Ni (p = 0.003) during the flood phase, because the incoming tide passes several point sources. DGT-reactive Cu concentrations significantly decreased with increased tidal-flushing and vice versa within a marina (correlation r = -0.788, p = 0.02). DGT measurements also recorded significant increases in Cu (4 out of 4 sites, p

2007-01-01

 
 
 
 
341

Stabilization of nonlinear systems with parametric uncertainty using variable structure techniques  

Energy Technology Data Exchange (ETDEWEB)

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

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

1995-07-01

342

An inverse neuro power system stabilizer using pole shifting control technique  

Energy Technology Data Exchange (ETDEWEB)

This paper presents a neuro pole shifting controller using the inverse Input-Output (I/O) mapping of the controlled system. A control law based on the pole shifting control scheme is suggested and derived in the form that the inverse I/O mapping can be directly used. The proposed control law guarantees overall stability including internal stability. A typical multilayered artificial neural net approximates the inverse I/O mapping of the controlled system and is used in the proposed controller, which is named Inverse Dynamics Neural Network (IDNN). The proposed neuro controller does not need any system emulator and is very simple in its implementation. A typical simple power system is simulated with the proposed controller to show its effectiveness. 14 refs, 6 figs

Park, Young-Moon; Hyun, Seung-Ho; Lee, Jin-Ho [Seoul National Univ. (Korea, Republic of). Dept. of Electrical Engineering; Lee, Heung-Jae [Kwang Woon Univ., Seoul (Korea, Republic of). Dept. of Electrical Engineering

1995-11-01

343

Application of stabilization techniques in the dynamic analysis of multibody systems  

Directory of Open Access Journals (Sweden)

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

Hajžman M.; Polach P.

2007-01-01

344

Modified resin-bonded design for stabilization of mobile teeth: technique and clinical observations.  

UK PubMed Central (United Kingdom)

A design modification of the tooth preparation and framework design is presented to further enhance stabilization of mobile teeth with resin-bonded splints. An appropriate shade of composite resin is placed to restore an esthetic contour, cover the incisal edge framework extensions, and provide occlusal function as indicated. Patient reviews are presented to demonstrate the principles of treatment, versatility, and limitations of this treatment modality.

Sokolowski J; Gunderson RB; Suliborski S

2001-09-01

345

Modified resin-bonded design for stabilization of mobile teeth: technique and clinical observations.  

Science.gov (United States)

A design modification of the tooth preparation and framework design is presented to further enhance stabilization of mobile teeth with resin-bonded splints. An appropriate shade of composite resin is placed to restore an esthetic contour, cover the incisal edge framework extensions, and provide occlusal function as indicated. Patient reviews are presented to demonstrate the principles of treatment, versatility, and limitations of this treatment modality. PMID:12017791

Sokolowski, J; Gunderson, R B; Suliborski, S

346

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

347

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

CERN Multimedia

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

348

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

UK PubMed Central (United Kingdom)

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.

Zhang XJ; Feng JG; Liu SZ; Wu XM

2013-02-01

349

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)

2012-01-01

350

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1996-11-01

351

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

International Nuclear Information System (INIS)

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

2011-01-01

352

Role of Plantar Plate and Surgical Reconstruction Techniques on Static Stability of Lesser Metatarsophalangeal Joints: A Biomechanical Study.  

UK PubMed Central (United Kingdom)

BACKGROUND: Disruption of the plantar plate of the lesser metatarsophalangeal (MTP) joints leads to significant instability. Despite the fact that plantar plate disorders are common, the best mode of treatment remains controversial with operative treatments having variable and somewhat unpredictable clinical outcomes. METHODS: Lesser MTP joints from the second, third, and fourth toes from fresh-frozen cadaver feet were biomechanically tested: (1) intact, (2) with the plantar plate disrupted, and (3) following a Weil osteotomy, a flexor-to-extensor tendon transfer, or a Weil osteotomy with a subsequent flexor-to-extensor tendon transfer with testing in superior subluxation, dorsiflexion, and plantarflexion. RESULTS: The plantar plate significantly contributed to stabilizing the sagittal plane of the lesser MTP joints. The flexor-to-extensor tendon transfer significantly stabilized the disrupted lesser MTP joints in both superior subluxation and in dorsiflexion. The flexor-to-extensor tendon transfer following a Weil osteotomy also significantly stabilized the disrupted lesser MTP joints in both superior subluxation and in dorsiflexion. CONCLUSIONS: In this cadaver-based experiment, disruption of the plantar plate of the lesser MTP joints led to significant instability. After plantar plate disruption, the Weil osteotomy left the joint unstable. The flexor-to-extensor tendon transfer by itself increased the stability of the joint in dorsiflexion, but combined with a Weil osteotomy restored near intact stability against superior subluxation and dorsiflexion forces. CLINICAL RELEVANCE: Surgeons using the Weil osteotomy for plantar plate deficient MTP joints may consider adding a flexor tendon transfer to the procedure. Techniques to repair the torn plantar plate directly are needed.

Chalayon O; Chertman C; Guss AD; Saltzman CL; Nickisch F; Bachus KN

2013-06-01

353

Role of plantar plate and surgical reconstruction techniques on static stability of lesser metatarsophalangeal joints: a biomechanical study.  

UK PubMed Central (United Kingdom)

BACKGROUND: Disruption of the plantar plate of the lesser metatarsophalangeal (MTP) joints leads to significant instability. Despite the fact that plantar plate disorders are common, the best mode of treatment remains controversial with operative treatments having variable and somewhat unpredictable clinical outcomes. METHODS: Lesser MTP joints from the second, third, and fourth toes from fresh-frozen cadaver feet were biomechanically tested: (1) intact, (2) with the plantar plate disrupted, and (3) following a Weil osteotomy, a flexor-to-extensor tendon transfer, or a Weil osteotomy with a subsequent flexor-to-extensor tendon transfer with testing in superior subluxation, dorsiflexion, and plantarflexion. RESULTS: The plantar plate significantly contributed to stabilizing the sagittal plane of the lesser MTP joints. The flexor-to-extensor tendon transfer significantly stabilized the disrupted lesser MTP joints in both superior subluxation and in dorsiflexion. The flexor-to-extensor tendon transfer following a Weil osteotomy also significantly stabilized the disrupted lesser MTP joints in both superior subluxation and in dorsiflexion. CONCLUSIONS: In this cadaver-based experiment, disruption of the plantar plate of the lesser MTP joints led to significant instability. After plantar plate disruption, the Weil osteotomy left the joint unstable. The flexor-to-extensor tendon transfer by itself increased the stability of the joint in dorsiflexion, but combined with a Weil osteotomy restored near intact stability against superior subluxation and dorsiflexion forces. CLINICAL RELEVANCE: Surgeons using the Weil osteotomy for plantar plate deficient MTP joints may consider adding a flexor tendon transfer to the procedure. Techniques to repair the torn plantar plate directly are needed.

Chalayon O; Chertman C; Guss AD; Saltzman CL; Nickisch F; Bachus KN

2013-10-01

354

Structural stability and self-healing capability of Er{sub 2}O{sub 3} in situ coating on V-4Cr-4Ti in liquid lithium  

Energy Technology Data Exchange (ETDEWEB)

The in situ Er{sub 2}O{sub 3} insulating coating is under development for the self-cooled Li/V-alloy type fusion blanket. In this study, the structural stability and self-healing capability of the coating are investigated. Since the cracking in the coating was not observed after exposure when Li was removed with a weak lotion (liquid NH{sub 3}), the cracking observed in the previous studies is not a practical issue in a real blanket. The re-exposure of the coating in pure Li showed that the coating once formed in Li (Er) is thought to be stable in pure Li. Thus, coating has the possibility to be serviced in a Li environment without an Er supply. By prior exposure to Li (Er) at 873 K, the exhaustion of the oxygen storage in V-alloy substrate during exposure at 973 K could be delayed effectively. The self-healing capability of the coating was demonstrated by the examination with the re-exposing cracked coating in Li (Er)

Yao, Zhenyu [Fusion Engineering Research Center, National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan)]. E-mail: yao@nuclear.jp; Suzuki, Akihiro [Department of Nuclear Engineering and Management, School of Engineering, University of Tokyo, 2-22 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1188 (Japan); Muroga, Takeo [Fusion Engineering Research Center, National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Nagasaka, Takuya [Fusion Engineering Research Center, National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan)

2006-11-15

355

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

International Nuclear Information System (INIS)

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

2006-01-01

356

X-ray Fluorescent Phosphors as in Situ Markers of X-ray Position for High-Pressure X-ray Techniques: Equation of State and X-ray Fluorescence Spectra to 40 GPa  

Science.gov (United States)

Their small size and heterogeneity make high-pressure samples in the diamond-anvil cell difficult to place perfectly in an x-ray beam to perform any of several analytical techniques (diffraction, scattering, etc.). X-ray fluorescent materials may help to solve this problem by providing a visual marker of the precise location of the x-ray beam or probe. In order to assess the utility of x-ray fluorescent markers for x-ray beam location at high-pressure conditions, we have characterized the high-pressure behavior of common x-ray fluorescent materials, particularly paying attention to structural stability at 300 K and high temperature, adequate fluorescence brightness, and potential use as an in situ pressure calibrant. We present x-ray diffraction and x-ray fluorescence (excited by x-rays, fluorescent in the visible range) data for two common x-ray phosphors: "red phosphor," Y2O3 doped with Eu, and "green phosphor," Gd2O2S doped with Tb. Red phosphor yttrium oxide undergoes two phase transitions from its initial cubic structure at 8 ± 2 GPa and 18 ± 2 GPa, and a third phase transformation occurs at high temperature during laser heating. In contrast Gd2O2S:Tb retains its hexagonal crystal structure with only slight modification to 40 GPa and during laser heating, and its volume and fluorescence peaks may be followed with increasing pressure making it a good material for in situ calibration of pressure as well as x-ray position. High pressure and temperature crystal structures, fluorescence spectra, and equation of state information will be presented for these two materials.

Benedetti, L. R.; Crichton, W. A.; Mezouar, M.

2004-12-01

357

A novel technique for enhancing efficiency and stability of CdTe based photoelectrochemical solar cells  

Energy Technology Data Exchange (ETDEWEB)

The photovoltage and photocurrent arising from CdTe/light yellow-S[sup 2-], S[sub 2][sup 2-]/C 'wet' solar cells has been measured. The effects of the S[sup 2-]/S[sub 2][sup 2-] ion concentration and the dye concentration have been studied in detail. Increase of the S[sup 2-]/ S[sub 2][sup 2-] ion concentration improves the efficiency of the cell while it also increases the response time. 'Light yellow' dye is found to improve the stability of the cell. (author)

Mishra, S.; Tiwari, S. (Government Autonomous Science College, Jabalpur (India). Dept. of Physics)

1994-10-14

358

Field test of electromagnetic geophysical techniques for locating simulated in situ mining leach solution. Report of investigations/1994  

Energy Technology Data Exchange (ETDEWEB)

The U.S. Bureau of Mines, the University of Arizona, Sandia National Laboratory, and Zonge Engineering and Research, Inc., conducted cooperative field tests of six electromagnetic geophysical methods to compare their effectiveness in locating a brine solution simulating in situ leach solution or a high-conductivity plume of contamination. The brine was approximately 160 meters below the surface. The test site was the University's San Xavier experimental mine near Tucson, Arizona. Geophysical surveys using surface and surface-borehole time-domain electromagnetics (TEM), surface controlled source audio-frequency magnetotellurics (CSAMT), surface-borehole frequency-domain electromagnetics (FEM), crosshole FEM and surface magnetic field ellipticity were conducted before and during brine injection.

Tweeton, D.R.; Hanson, J.C.; Friedel, M.J.; Sternberg, B.K.; Dahl, L.J.

1994-01-01

359

Development of a technique for in situ high temperature TEM observation of catalysts in a highly moisturized air atmosphere.  

UK PubMed Central (United Kingdom)

To clarify the influence of moisture on the structural changes of heated nano materials, in situ high temperature transmission electron microscopy (TEM) has been carried out using a conventional analytical TEM combined with a gas injection-specimen heating holder. Air with high moisture content, above 94% relative humidity (RH), from a humidifier was directly injected onto the heated platinum catalyst dispersed on carbon black (Pt/CB), and the morphological changes of the specimens were observed at high magnification dynamically. The result of the experiment was compared with a result obtained from an experiment using air with a low moisture content, 34% RH. Active movement of the Pt particles, leading agglomeration and grain growth, occurred prior to degradation of the CB support at high moisture content. In contrast, the degradation of the CB support leading agglomeration and grain growth of the Pt particles occurred before the displacement of the Pt particles on the CB supports in a low humidity environment.

Yaguchi T; Kanemura T; Shimizu T; Imamura D; Watabe A; Kamino T

2012-08-01

360

Development of a technique for in situ high temperature TEM observation of catalysts in a highly moisturized air atmosphere.  

Science.gov (United States)

To clarify the influence of moisture on the structural changes of heated nano materials, in situ high temperature transmission electron microscopy (TEM) has been carried out using a conventional analytical TEM combined with a gas injection-specimen heating holder. Air with high moisture content, above 94% relative humidity (RH), from a humidifier was directly injected onto the heated platinum catalyst dispersed on carbon black (Pt/CB), and the morphological changes of the specimens were observed at high magnification dynamically. The result of the experiment was compared with a result obtained from an experiment using air with a low moisture content, 34% RH. Active movement of the Pt particles, leading agglomeration and grain growth, occurred prior to degradation of the CB support at high moisture content. In contrast, the degradation of the CB support leading agglomeration and grain growth of the Pt particles occurred before the displacement of the Pt particles on the CB supports in a low humidity environment. PMID:22460387

Yaguchi, Toshie; Kanemura, Takashi; Shimizu, Takahiro; Imamura, Daichi; Watabe, Akira; Kamino, Takeo

2012-03-29

 
 
 
 
361

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

362

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)

[en] 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

1997-01-01

363

Polytype stability and defect reduction in 4H-SiC crystals grown via sublimation technique  

Energy Technology Data Exchange (ETDEWEB)

Reproducible growth of 4H-SiC with good crystalline quality has been obtained in a temperature interval around 2,350 C and on 4H-SiC C-face seeds. It has been observed that morphological instability may appear at the initial stage of growth, causing formation of defects. Experimental evidence has been found that supersaturation and surface kinetics are responsible for the polytype stability, while growth front and growth mode address defect reduction. An explanation of the findings has been suggested. It has been shown that starting the growth with a relatively low growth rate ({approx} 100 {micro}m/h) can be beneficial for the crystal quality.

Yakimova, R.; Iakimov, T.; Syvaejaervi, M.; Jacobsson, H.; Raaback, P.; Vehanen, A.; Janzen, E.

1999-07-01

364

Investigation of laser-CVD process through on-line optical diagnostics and in-situ surface sensitive analysis techniques  

Energy Technology Data Exchange (ETDEWEB)

Excimer lasers have been widely used in recent years to induce chemical vapor deposition (L-CVD) of thin films from volatile organometallic molecules. The purpose of this paper is to correlate the mechanism of photo-induced ligand removal in the laser photolysis of organometallic compounds with film composition and growth. ArF laser irradiated TMT (tetramethyltin) was used as a model system. On-line optical diagnostics were employed to investigate the effect of ArF laser fluence and buffer gas (Ar, N{sub 2}, O{sub 2}) addition on the photodissociation of TMT. In-situ Auger analysis permitted the researchers to determine the composition of the films deposited by ArF laser irradiation of TMT in the vicinity of a substrate and to investigate the progressive oxidation of the tin films consequent to dilution of TMT in oxygen. It was found that incomplete elimination of organic radicals in the UV photolysis of TMT causes the presence of C in the photodeposited tin films. O{sub 2} is effective in promoting Sn film oxidation and in eliminating carbon contamination through a chemical reaction with ligand carrying photo-fragments followed by the formation of volatile organic compounds and stable Sn-O bonds.

Borsella, E.; Larciprete, R. [ENEA, Frascati (Italy). Dipt. Sviluppo Tecnologie di Punta; Nesterenko, A. [Russian Accademy of Sciences, Moscow (Russian Federation). General Physics Institute

1993-01-01

365

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

366

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; M. Haeckel; I. Klaucke; M. K. Ivanov; G. Bohrmann

2011-01-01

367

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

368

Analysis of microRNA niches: techniques to measure extracellular microRNA and intracellular microRNA in situ.  

UK PubMed Central (United Kingdom)

MicroRNAs (miRNAs) are small, noncoding RNA molecules that negatively regulate gene expression and control a wide range of cellular processes. Extracellular forms of miRNA circulating in the bloodstream (circulating miRNA, c-miRNA) are of increasing interest for their potential as biomarkers and long-range physiological signaling molecules. Precise measurement of intracellular miRNA expression is possible but can be challenging, especially in the context of specialized tissue niches in vivo. The accurate measurement of extracellular miRNA presents other obstacles stemming from their low concentrations and confounding sources of intracellular miRNA that contaminate RNA extraction protocols. Here, we describe multiple methods to isolate extracellular miRNA from cell culture media, serum, and plasma in order to accurately measure their variable expression under different conditions. We additionally describe an in situ staining protocol designed to not only quantify but also localize miRNA in formalin-fixed paraffin-embedded tissue that may prove useful in describing the action of c-miRNA before they leave their tissue of origin and after they potentially arrive at their target destination.

Parikh VN; Chan SY

2013-01-01

369

Assessment of the efficiency of in situ bioremediation techniques in a creosote polluted soil: Change in bacterial community.  

UK PubMed Central (United Kingdom)

This work aimed to assess the effectiveness of different in situ bioremediation treatments (bioaugmentation, biostimulation, bioaugmentation and biostimulation, and natural attenuation) on creosote polluted soil. Toxicity, microbial respiration, creosote degradation and the evolution of bacterial communities were analyzed. Results showed that creosote decreased significantly in all treatments, and no significant differences were found between treatments. However, some specific polycyclic aromatic hydrocarbons (PAH) were degraded to a greater extent by biostimulation. The dominance of low temperatures (8.9°C average) slowed down microbial creosote and PAH uptake and, despite significantly creosote degradation (>60%) at the end of the experiment, toxicity remained constant and high throughout the biodegradation process. DGGE results revealed that biostimulation showed the highest microbial biodiversity, although at the end of the biodegradation process, community composition in all treatments was different from that of the control assay (unpolluted soil). The active uncultured bacteria belonged to the genera Pseudomonas, Sphingomonas, Flexibacter, Pantoea and Balneimonas, the latter two of which have not been previously described as PAH degraders. The majority of the species identified during the creosote biodegradation belonged to Pseudomonas genus, which has been widely studied in bioremediation processes. Results confirmed that some bacteria have an intrinsic capacity to degrade the creosote without previous exposure.

Simarro R; González N; Bautista LF; Molina MC

2013-08-01

370

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

Energy Technology Data Exchange (ETDEWEB)

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

Dunn, R.J.K. [School of Environmental and Applied Science, Griffith University Gold Coast Campus, PMB 50 Gold Coast Mail Centre, Queensland 9726 (Australia); Teasdale, P.R. [Centre for Aquatic Processes and Pollution, Griffith University Gold Coast Campus, PMB 50 Gold Coast Mail Centre, Queensland 9726 (Australia)]. E-mail: p.teasdale@griffith.edu.au; Warnken, J. [Centre for Aquatic Processes and Pollution, Griffith University Gold Coast Campus, PMB 50 Gold Coast Mail Centre, Queensland 9726 (Australia); Jordan, M.A. [School of Environmental and Applied Science, Griffith University Gold Coast Campus, PMB 50 Gold Coast Mail Centre, Queensland 9726 (Australia); Arthur, J.M. [Centre for Riverine Landscapes, Griffith University Gold Coast Campus, PMB 50 Gold Coast Mail Centre, Queensland 9726 (Australia)

2007-07-15

371

In-situ imaging of nanoscale ethanol film formation on mica surface under saturated vapor condition using VSPFM technique  

International Nuclear Information System (INIS)

In this paper, vibrating scanning polarization force microscopy (VSPFM) technique is used to study the adsorption of ethanol gas molecules on mica surface at room temperature, and the relationship between bias and imaging quality. Experiment results showed that the best images can be acquired when the tip is biased at AC 5 V.VSPFM is a useful technique to investigate air-solid interaction. Using this technique, we found that ethanol gas molecule did not adsorb quickly on mica surface, and the ethanol adsorption behavior could not be illustrated by Langmuir adsorption model, as it took hours for the ethanol vapor molecules to be adsorbed on mica to form a nanoscale film from nucleated dots or islands. (authors)

2011-01-01

372

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

373

Scanning laser polarimetry of retinal nerve fibre layer thickness after laser assisted in situ keratomileusis (LASIK): stability of the values after the third post-LASIK month.  

UK PubMed Central (United Kingdom)

BACKGROUND: Monitoring the retinal nerve fibre layer thickness (RNFLT) is essential in the diagnosis and treatment of glaucoma. In a previous study we found that a decrease of the polarimetric RNFLT observed in the early period after laser-assisted in situ keratomileusis (LASIK) disappears or tends to disappear by the third post-LASIK month. PURPOSE: To study the stability of the "recovered" polarimetric retardation values between the third and twelfth month after LASIK. METHODS: Scanning laser polarimetry (SLP) with the classic GDx Nerve Fiber Analyzer was performed on 13 consecutive healthy subjects with no eye disease who underwent LASIK for ametropia correction. Measurements were performed preoperatively, then at 3 and 12 months postoperatively. RESULTS: Inferior, temporal and nasal average thickness as well as ellipse average thickness and average thickness showed no difference among the three time points (ANOVA, p > 0.05). Superior average thickness was significantly smaller both at three months (Sheffe test, p =0.008) and 12 months (p =0.006) than before LASIK. However, no difference w