WorldWideScience
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Chemically enhanced in situ recovery  

Energy Technology Data Exchange (ETDEWEB)

Chemically enhanced recovery is a promising alternative to current technologies for management of subsurface releases of organic liquids. Through the inclusion of surfactants, solvents, polymers, and/or alkaline agents to a waterflood, the transport of targeted organic compounds can be increased and rates of recovery enhanced. By far, the vast majority of work done in the field of chemically enhanced recovery has been at a laboratory scale. The following text focuses on chemically enhanced recovery from a field application perspective with emphasis given to chlorinated solvents in a low permeability setting. While chlorinated solvents are emphasized, issues discussed are also relevant to organic liquids less dense than water such as petroleum products. Topics reviewed include: (1) Description of technology; (2) General technology considerations; (3) Low permeability media considerations; (4) Cost and reliability considerations; (5) Commercial availability; and (6) Case histories. Through this paper an appreciation is developed of both the potential and limitations of chemically enhanced recovery. Excluded from the scope of this paper is the in situ destruction of organic compounds through processes such as chemical or biological oxidation, chemically enhanced recovery of inorganic compounds, and ex situ soil treatment processes. 11 refs., 2 figs., 1 tab.

Sale, T. [CH2M Hill, Denver, CO (United States); Pitts, M.; Wyatt, K. [Surtek, Inc., Golden, CO (United States)] [and others

1996-08-01

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Enhancing in situ bioremediation with pneumatic fracturing  

International Nuclear Information System (INIS)

A major technical obstacle affecting the application of in situ bioremediation is the effective distribution of nutrients to the subsurface media. Pneumatic fracturing can increase the permeability of subsurface formations through the injection of high pressure air to create horizontal fracture planes, thus enhancing macro-scale mass-transfer processes. Pneumatic fracturing technology was demonstrated at two field sites at Tinker Air Force Base, Oklahoma City, Oklahoma. Tests were performed to increase the permeability for more effective bioventing, and evaluated the potential to increase permeability and recovery of free product in low permeability soils consisting of fine grain silts, clays, and sedimentary rock. Pneumatic fracturing significantly improved formation permeability by enhancing secondary permeability and by promoting removal of excess soil moisture from the unsaturated zone. Postfracture airflows were 500% to 1,700% higher than prefracture airflows for specific fractured intervals in the formation. This corresponds to an average prefracturing permeability of 0.017 Darcy, increasing to an average of 0.32 Darcy after fracturing. Pneumatic fracturing also increased free-product recovery rates of number 2 fuel from an average of 587 L (155 gal) per month before fracturing to 1,647 L (435 gal) per month after fracturing

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Enhancing in situ bioremediation with pneumatic fracturing  

Energy Technology Data Exchange (ETDEWEB)

A major technical obstacle affecting the application of in situ bioremediation is the effective distribution of nutrients to the subsurface media. Pneumatic fracturing can increase the permeability of subsurface formations through the injection of high pressure air to create horizontal fracture planes, thus enhancing macroscale mass-transfer processes. Pneumatic fracturing technology was demonstrated at two field sites at Tinker Air Force Base, Oklahoma City, Oklahoma. Tests were performed to increase the permeability for more effective bioventing, and evaluated the potential to increase permeability and recovery of free product in low-permeability soils consisting of fine-grain silts, clays, and sedimentary rock. Pneumatic fracturing significantly improved formation permeability by enhancing secondary permeability and by promoting removal of excess soil moisture form the unsaturated zone. Postfracture airflows were 500% to 1,700% higher than prefracture airflows for specific fractured intervals in the formation. This corresponds to an average prefracturing permeability of 0.017 darcy, increasing to an average of 0.32 darcy after fracturing. Pneumatic fracturing also increased free-product recovery rates of number 2 fuel from an average of 587 L (155 gal) per month before fracturing to 1,647 L (435 gal) per month after fracturing.

Anderson, D.B.; Peyton, B.M. [Battelle Pacific Northwest, Richland, WA (United States); Liskowitz, J.J.; Fitzgerald, C.D. [Accutech Remedial Systems, Keyport, NJ (United States); Schuring, J.R. [New Jersey Inst. of Tech., Newark, NJ (United States). Dept. of Chemical Engineering, Chemistry, and Environmental Science

1995-12-31

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SITE TECHNOLOGY CAPSULE: IN SITU STEAM ENHANCED RECOVERY PROCESS  

Science.gov (United States)

This Technology Capsule report summarizes the findings of an evaluation of the in situ Steam Enhanced Recovery Process (SERP) operated by Hughes Environmental Systems, Inc. at the Rainbow Disposal facility in Huntington Beach, California. he technology demonstration was conducted...

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Enhancement of in situ Remediation of Hydrocarbon Contaminated Soil  

Energy Technology Data Exchange (ETDEWEB)

Approximately 750 000 sites of contaminated land exist across Europe. The harmful chemicals found in Finnish soils include heavy metals, oil products, polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), chlorophenols, and pesticides. Petroleum and petroleum products enter soil from ruptured oil pipelines, land disposal of refinery products, leaking storage tanks and through accidents. PAH contamination is caused by the spills of coal tar and creosote from coal gasification and wood treatment sites in addition to oil spills. Cleanup of soil by bioremediation is cheaper than by chemical and physical processes. However, the cleaning capacity of natural attenuation and in situ bioremediation is limited. The purpose of this thesis was to find feasible options to enhance in situ remediation of hydrocarbon contaminants. The aims were to increase the bioavailability of the contaminants and microbial activity at the subsurface in order to achieve higher contaminant removal efficiency than by intrinsic biodegradation alone. Enhancement of microbial activity and decrease of soil toxicity during remediation were estimated by using several biological assays. The performance of these assays was compared in order to find suitable indicators to follow the progress of remediation. Phytoremediation and chemical oxidation are promising in situ techniques to increase the degradation of hydrocarbons in soil. Phytoremediation is plant-enhanced decontamination of soil and water. Degradation of hydrocarbons is enhanced in the root zone by increased microbial activity and through the detoxifying enzymes of plants themselves. Chemical oxidation of contaminants by Fenton's reaction can produce degradation products which are more biodegradable than the parent compounds. Fenton's reaction and its modifications apply solutions of hydrogen peroxide and iron for the oxidation of organic chemicals. The cost of oxidation can be reduced by aiming at partial instead of full oxidation of contaminants and by integrating the process to biological treatment, in which the formed degradation products can be biodegraded. Phytoremediation was used to remove fresh and aged petroleum hydrocarbons from soil, and modified FentonAEs reaction combined with biodegradation was used to remove aged creosote oil from soil. The effects of hydrocarbon aging, different plant species and soil amendments on the removal efficiency were studied in phytoremediation experiments. Lab-scale experiments were made with fresh diesel fuel, and a field study was made with aged hydrocarbons deriving from diesel fuel and lubricants. The used plant species were pine, poplar, a grass mixture and a legume mixture. The experiments with modified Fenton's treatment were carried out in soil columns, to which concentrated H{sub 2}O{sub 2} was added simulating in situ injection. Iron was not added since the soil was rich in iron. After FentonAEs treatment, the soil was incubated in serum bottles to determine the effects on bioavailability of PAHs by modified FentonAEs oxidation and to simulate the potential of intrinsic remediation. In addition to hydrocarbon analyses, the effects of both methods on soil microbial activities and toxicity were determined. In the presence of white clover and green pea, pine or poplar, 89 to 98 % of diesel fuel was removed, whereas the presence of grasses did not increase diesel fuel removal compared to treatment without plants, where up to 86 % of diesel fuel was removed. When diesel was applied to the trees for a second time, reduction in one month was 9 to 25 % higher than what was achieved after first month of first application. During the four growing season study with soil contaminated with aged hydrocarbon contaminants, the presence of vegetation did not increase hydrocarbon removal in unfertilised soil. Vegetation cover was denser in amended soil than in unfertilised soil. The addition of compost or NPK fertiliser enhanced hydrocarbon removal. However, the toxicity of aged hydrocarbon contaminated soil to Vibrio fischeri (a luminesc

Palmroth, M.

2006-07-01

6

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

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In situ enhanced soil mixing. Innovative technology summary report  

International Nuclear Information System (INIS)

In Situ Enhanced Soil Mixing (ISESM) is a treatment technology that has been demonstrated and deployed to remediate soils contaminated with volatile organic compounds (VOCs). The technology has been developed by industry and has been demonstrated with the assistance of the U.S. Department of Energy's Office of Science and Technology and the Office of Environmental Restoration. The technology is particularly suited to shallow applications, above the water table, but can be used at greater depths. ISESM technologies demonstrated for this project include: (1) Soil mixing with vapor extraction combined with ambient air injection. [Contaminated soil is mixed with ambient air to vaporize volatile organic compounds (VOCs). The mixing auger is moved up and down to assist in removal of contaminated vapors. The vapors are collected in a shroud covering the treatment area and run through a treatment unit containing a carbon filter or a catalytic oxidation unit with a wet scrubber system and a high efficiency particulate air (HEPA) filter.] (2) soil mixing with vapor extraction combined with hot air injection [This process is the same as the ambient air injection except that hot air or steam is injected.] (3) soil mixing with hydrogen peroxide injection [Contaminated soil is mixed with ambient air that contains a mist of diluted hydrogen peroxide (H2O2) solution. The H2O2 solution chemically oxidizes the VOCs to carbon dioxide (CO2dizes the VOCs to carbon dioxide (CO2) and water.] (4) soil mixing with grout injection for solidification/stabilization [Contaminated soil is mixed as a cement grout is injected under pressure to solidify and immobilize the contaminated soil in a concrete-like form.] The soils are mixed with a single-blade auger or with a combination of augers ranging in diameter from 3 to 12 feet

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IN SITU STEAM ENHANCED RECOVERY PROCESS - HUGHES ENVIRONMENTAL SYSTEMS, INC., - INNOVATIVE TECHNOLOGY REPORT  

Science.gov (United States)

This Innovative Technology Evaluation report summarizes the findings of an evaluation of the in situ Steam Enhanced Recovery Process (SERP) operated by Hughes Environmental Systems, Inc. at the Rainbow Disposal facility in Huntington Beach, California. he technology demonstration...

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IN SITU STEAM ENHANCED RECOVERY PROCESS - HUGHES ENVIRONMENTAL SYSTEMS, INC. - INNOVATIVE TECHNOLOGY EVALUATION REPORT  

Science.gov (United States)

This Innovative Technology Evaluation report summarizes the findings of an evaluation of the in situ Steam Enhanced Recovery Process (SERP) operated by Hughes Environmental Systems, Inc. at the Rainbow Disposal facility in Huntington Beach, California. he technology demonstration...

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Cost studies of thermally enhanced in situ soil remediation technologies  

International Nuclear Information System (INIS)

This report describes five thermally enhanced technologies that may be used to remediate contaminated soil and water resources. The standard methods of treating these contaminated areas are Soil Vapor Extraction (SVE), Excavate ampersand Treat (E ampersand T), and Pump ampersand Treat (P ampersand T). Depending on the conditions at a given site, one or more of these conventional alternatives may be employed; however, several new thermally enhanced technologies for soil decontamination are emerging. These technologies are still in demonstration programs which generally are showing great success at achieving the expected remediation results. The cost savings reported in this work assume that the technologies will ultimately perform as anticipated by their developers in a normal environmental restoration work environment. The five technologies analyzed in this report are Low Frequency Heating (LF or Ohmic, both 3 and 6 phase AC), Dynamic Underground Stripping (DUS), Radio Frequency Heating (RF), Radio Frequency Heating using Dipole Antennae (RFD), and Thermally Enhanced Vapor Extraction System (TEVES). In all of these technologies the introduction of heat to the formation raises vapor pressures accelerating contaminant evaporation rates and increases soil permeability raising diffusion rates of contaminants. The physical process enhancements resulting from temperature elevations permit a greater percentage of volatile organic compound (VOC) or semi- volatile organic compound (SVOC) contaminants to be driven out of the soils for treatment or capture in a much shorter time period. This report presents the results of cost-comparative studies between these new thermally enhanced technologies and the conventional technologies, as applied to five specific scenarios

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DEMONSTRATION BULLETIN: IN SITU STEAM ENHANCED RECOVERY PROCESS - HUGHES ENVIRONMENTAL SYSTEMS, INC.  

Science.gov (United States)

The Steam Enhanced Recovery Process (SERP) is designed to remove volatile compounds such as halogenated solvents and petroleum hydrocarbons, and semi-volatile compounds from contaminated soils in situ. The vapor pressures of most contaminants will increase by the addition of ste...

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Spectroscopic in situ diagnostics of boron nitride film growth in plasma-enhanced deposition  

Energy Technology Data Exchange (ETDEWEB)

The development of in situ diagnostics of the most important species and reactions in the plasma and/or on the surface during thin-film growth is one of the current topics in plasma-enhanced vapor deposition. In situ thin film diagnostic methods which could be used in plasma processing are restricted due to the presence of electrons and ions. The advantages and disadvantages of different applicable methods will be discussed. The spectroscopic in situ control of boron nitride film growth is presented as an example of surface modification in low-temperature, low-pressure plasma processing. The growth of cubic and hexagonal boron nitride is observed by polarized infrared reflection spectroscopy in absorption and ellipsometric configurations as well as by single-wavelength ellipsometry in the visible spectral range. Modeling of the experimental results gives detailed information on growth conditions and internal stress of the films. (orig.)

Lunk, A.; Bachem, P.; Scheible, P.; Ulrich, L. [Stuttgart Univ. (Germany)

2001-05-01

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In situ transmission electron microscope studies of irradiation-induced and irradiation-enhanced phase changes  

Energy Technology Data Exchange (ETDEWEB)

Motivated at least initially by materials needs for nuclear reactor development, extensive irradiation effects studies employing TEMs have been performed for several decades, involving irradiation-induced and irradiation-enhanced, microstructural changes, including phase transformations such as precipitation, dissolution, crystallization, amorphization, and order-disorder phenomena. From the introduction of commercial high voltage electron microscopes (HVEM) in the mid-1960s, studies of electron irradiation effects have constituted a major aspect of HVEM application in materials science. For irradiation effects studies two additional developments have had particularly significant impact: (1) The availability of TEM specimen holders in which specimen temperature can be controlled in the range 10--2200 K; and (2) the interfacing of ion accelerators which allows in situ TEM studies of irradiation effects and the ion beam modification of materials within this broad temperature range. This paper treats several aspects of in situ studies of electron and ion beam-induced and enhanced phase changes, including the current state of in situ ion beam capability internationally, and presents two case studies involving in situ experiments performed in an HVEM to illustrate the dynamics of such an approach in materials research.

Allen, C.W.

1991-12-31

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In situ transmission electron microscope studies of irradiation-induced and irradiation-enhanced phase changes  

Energy Technology Data Exchange (ETDEWEB)

Motivated at least initially by materials needs for nuclear reactor development, extensive irradiation effects studies employing TEMs have been performed for several decades, involving irradiation-induced and irradiation-enhanced, microstructural changes, including phase transformations such as precipitation, dissolution, crystallization, amorphization, and order-disorder phenomena. From the introduction of commercial high voltage electron microscopes (HVEM) in the mid-1960s, studies of electron irradiation effects have constituted a major aspect of HVEM application in materials science. For irradiation effects studies two additional developments have had particularly significant impact: (1) The availability of TEM specimen holders in which specimen temperature can be controlled in the range 10--2200 K; and (2) the interfacing of ion accelerators which allows in situ TEM studies of irradiation effects and the ion beam modification of materials within this broad temperature range. This paper treats several aspects of in situ studies of electron and ion beam-induced and enhanced phase changes, including the current state of in situ ion beam capability internationally, and presents two case studies involving in situ experiments performed in an HVEM to illustrate the dynamics of such an approach in materials research.

Allen, C.W.

1991-01-01

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Application Research of Enhanced in-situ micro-ecological Remediation for Oil Contaminated Soil  

Directory of Open Access Journals (Sweden)

Full Text Available The reduction of the oil content in soil contaminated by the exploitation of oil field in Zhongyuan District that was then recovered for use has been realized in this paper, through the enhanced in-situ micro-ecological remediation method that is micro-ecological remediation technique, by which the cultivation of alfalfa is combined with the regulation of soil environmental factors by means of the enhanced in-situ microbial communities companied with physical and chemical means. The experimental results showed that the oil contents in the contaminated soil with the average 2898.25 mg/kg can be reduced to about 99.37% after the in-situ micro-ecological remediation after the above mentioned recovery for 99 days, which demonstrated the effectiveness of the in-situ micro-ecological remediation methods for oil contaminated soil in this district, meanwhile, the practical and feasible application of these methods have been explored in this paper.

Sheng Zhang

2013-12-01

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Enhancing the design of in situ chemical barriers with multicomponent reactive transport modeling  

International Nuclear Information System (INIS)

This paper addresses the need for systematic control of field-scale performance in the emplacement and operation of in situ chemical treatment barriers; in particular, it addresses the issue of how the local coupling of reaction kinetics and material heterogeneities at the laboratory or bench scale can be accurately upscaled to the field. The authors have recently developed modeling analysis tools that can explicitly account for all relevant chemical reactions that accompany the transport of reagents and contaminants through a chemically and physically heterogeneous subsurface rock or soil matrix. These tools are incorporated into an enhanced design methodology for in situ chemical treatment technologies, and the new methodology is demonstrated in the ongoing design of a field experiment for the In Situ Redox Manipulation (ISRM) project at the U.S. Department of Energy (DOE) Hanford Site. The ISRM design approach, which systematically integrates bench-scale and site characterization information, provides an ideal test for the new reactive transport techniques. The need for the enhanced chemistry capability is demonstrated by an example that shows how intra-aqueous redox kinetics can affect the transport of reactive solutes. Simulations are carried out on massively parallel computer architectures to resolve the influence of multiscale heterogeneities on multicomponent, multidimensional reactive transport. The technology will soon be available to design larger-scale remediation schemes

17

Graphene oxide adsorption enhanced by in situ reduction with sodium hydrosulfite to remove acridine orange from aqueous solution.  

Science.gov (United States)

Graphene oxide (GO) is a highly effective adsorbent, and its absorbing capability is further enhanced through its in situ reduction with sodium hydrosulfite as the reductant. Acridine orange is the selected target to eliminate with GO as the adsorbent. Under identical conditions, GO without the in situ reduction showed a maximum adsorption capacity of 1.4 g g(-1), and GO with the in situ reduction provided a maximum adsorption capacity of 3.3 g g(-1). Sodium hydrosulfite converts carbonyl groups on GO into hydroxyl groups, which function as the key sites for the adsorption enhancement. PMID:22206973

Sun, Ling; Yu, Hongwen; Fugetsu, Bunshi

2012-02-15

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Enhanced bioavailability of poorly absorbed hydrophilic compounds through drug complex/in situ gelling formulation.  

Science.gov (United States)

BCS class III hydrophilic compounds are often associated with low oral bioavailability due to their poor epithelial permeability in the gastrointestinal tract. In this study, we reported an approach of incorporating a drug complex into an in situ gelling muco-adhesive carrier to achieve an improved bioavailability of a poorly absorbed hydrophilic compound. A new molecular entity (RWJ-445167) from Johnson and Johnson was used as a model compound. The compound was first complexed with sodium lauryl sulfate (SLS). The complex was then incorporated into an in situ gelling muco-adhesive carrier Cremophor for formulation characterization and rat pharmacokinetic (PK) studies. The study results showed that RWJ-445167 bound to SLS at a stoichiometric ratio. By complexing with SLS, the compound became lipophilic. The aqueous solubility of RWJ-445167 dropped to 0.58 mg/mL for the complex from 61 mg/mL for the free compound, while the partitioning coefficient of the complex increased to 7.59, compared with 0.05 of the free compound. In the rat PK study, with duodenal administration, the complex in the in situ-gelling formulation achieved 28.24% of bioavailability, compared to 4.26% of the free compound solution. The enhanced bioavailability was also significantly higher than those in the RWJ-445167/SLS physical mixture in Cremophor (14.91%), the complex in non-gelling carrier PEG 400 (9.95%) and the RWJ-445167/SLS physical mixture in PEG 400 carrier (8.60%). The study demonstrates that incorporation of a drug complex into an in situ gelling formulation provides a new approach to improving bioavailability of BCS class III drugs. PMID:24004566

Dai, Wei-Guo; Dong, Liang C; Song, Yanqiu

2013-11-30

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Controlled in situ nanoscale enhancement of gold nanowire arrays with plasmonics  

Energy Technology Data Exchange (ETDEWEB)

The controlled in situ growth of ordered gold nanoparticles and nanowire arrays has been studied by optically tracking changes in the local surface plasmon resonance (LSPR) spectrum. A spectrometer and custom-programmed analysis software track changes in the LSPR spectrum. The peak position, peak height (i.e. extinction intensity) and peak width (e.g. radius of curvature) were tracked over time to quantify the dynamic growth of gold as soon as the system was exposed to a commercial gold enhancement solution. This enables the controlled dynamic growth of nano-objects without the necessity of characterizing the growth and aggregation kinetics of the gold enhancement solution. The result was the successful enhancement of their electrically conductive and plasmonic properties, as well as the controlled growth and transformation of line-patterned nanoparticles into conductive particle-based nanowires.

MacKenzie, Robert; Fraschina, Corrado; Sannomiya, Takumi; Voeroes, Janos, E-mail: janos.voros@biomed.ee.ethz.ch [Laboratory of Biosensors and Bioelectronics, ETH Zurich, Gloriastrasse 35, 8092 Zurich (Switzerland)

2011-02-04

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Controlled in situ nanoscale enhancement of gold nanowire arrays with plasmonics  

International Nuclear Information System (INIS)

The controlled in situ growth of ordered gold nanoparticles and nanowire arrays has been studied by optically tracking changes in the local surface plasmon resonance (LSPR) spectrum. A spectrometer and custom-programmed analysis software track changes in the LSPR spectrum. The peak position, peak height (i.e. extinction intensity) and peak width (e.g. radius of curvature) were tracked over time to quantify the dynamic growth of gold as soon as the system was exposed to a commercial gold enhancement solution. This enables the controlled dynamic growth of nano-objects without the necessity of characterizing the growth and aggregation kinetics of the gold enhancement solution. The result was the successful enhancement of their electrically conductive and plasmonic properties, as well as the controlled growth and transformation of line-patterned nanoparticles into conductive particle-based nanowires.

21

Integrated modelling of enhanced in situ biodenitrification in a fractured aquifer: biogeochemistry and isotope geochemistry  

Science.gov (United States)

Enhanced in-situ biodenitrification is a feasible technology to recovery groundwater polluted by nitrates and achieves drinking water standards. Under optimum conditions, nitrate is reduced by autochthonous bacteria trough different reactions until arrive to harmless dinitrogen gas. Isotopic fractionation monitoring in field applications allows knowing the exact degree and the real scope of this technology. Using the Rayleigh equation the change in the isotope ratio of the nitrate molecule (?15N-NO3-, ?18O-NO3-) is related to the fraction of molecules remaining as a result of biodenitrification. However, Rayleigh application at field scale is sometimes limited due to other processes involved during groundwater flow such as dispersion or adsorption and geological media heterogeneities that interferes in concentration values. Then, include isotope fractionation processes in reactive transport models is a useful tool to interpret and predict data from in-situ biodenitrification. We developed a reactive transport model of enhanced in situ application at field scale in a fractured aquifer that considers biogeochemical processes as well as isotope fractionation to enable better monitoring and management of this technology. Processes considered were: microbiological- exogenous and endogenous nitrate and sulfate respiration coupled with microbial growth and decay, geochemical reactions (precipitation of calcite) and isotopic fractionation (?15N-NO3-; ?18O- NO3- and carbon isotope network). The 2-D simulations at field scale were developed using PHAST code. Modeling of nitrate isotope geochemistry has allowed determining the extent of biodenitrification in model domain. We have quantified which is the importance in decreasing of nitrate concentrations due to biodegradation (percentage of biodegradation, 'B%') and due to dilution process (percentage of dilution, 'D%'). On the other hand, the stable carbon isotope geochemistry has been modeled. We have considered the isotopic carbon fractionation of different carbon species involved in enhanced biodenitrification: external organic carbon, biomass, inorganic carbon (in different forms) and calcite. The inclusion of carbon isotopes in the model, which are involved in both direct (oxidation of organic carbon) and indirect (carbonate mineral interaction) processes of enhanced biodenitrification, improves the evaluation of the overall model consistency due to the central role of carbon in the reaction network.

Rodríguez-Escales, Paula; Folch, Albert; van Breukelen, Boris M.; Vidal-Gavilan, Georgina; Soler, Albert

2014-05-01

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Multiwalled carbon nanotubes enhance electrochemical properties of titanium to determine in situ bone formation  

International Nuclear Information System (INIS)

Multiwalled carbon nanotubes (MWCNTs) enhance osteoblast (bone-forming cell) calcium deposition compared to currently implanted materials (such as titanium). In this study, MWCNTs were grown out of nanopores anodized on titanium (MWCNT-Ti). The electrochemical responses of MWCNT-Ti were investigated in an attempt to ascertain if MWCNT-Ti can serve as novel in situ sensors of bone formation. For this purpose, MWCNT-Ti was subjected to a ferri/ferrocyanide redox couple and its electrochemical behavior measured. Cyclic voltammograms (CVs) showed an enhanced redox potential for the MWCNT-Ti. These redox signals were superior to that obtained with bare unmodified Ti, which did not sense either oxidation or reduction peaks in the CVs. A further objective of this study was to investigate the redox reactions of MWCNT-Ti in a solution of extracellular components secreted by osteoblasts in vitro. It was found that MWCNT-Ti exhibited well-defined and persistent CVs, similar to the ferri/ferrocyanide redox reaction. The higher electrodic performance and electrocatalytic activity of the MWCNT-Ti compared to the bare titanium observed in this study were likely due to the fact that MWCNTs enhanced direct electron transfer and facilitated double-layer effects, leading to a strong redox signal. Thus these results encourage the further study and modification of MWCNT-Ti to sense new bone growth in situ next to orthopedic implants and perhaps monitor other events (such as infection and/nitor other events (such as infection and/or harmful scar tissue formation) to improve the current clinical diagnosis of orthopedic implants

23

Multiwalled carbon nanotubes enhance electrochemical properties of titanium to determine in situ bone formation  

Science.gov (United States)

Multiwalled carbon nanotubes (MWCNTs) enhance osteoblast (bone-forming cell) calcium deposition compared to currently implanted materials (such as titanium). In this study, MWCNTs were grown out of nanopores anodized on titanium (MWCNT-Ti). The electrochemical responses of MWCNT-Ti were investigated in an attempt to ascertain if MWCNT-Ti can serve as novel in situ sensors of bone formation. For this purpose, MWCNT-Ti was subjected to a ferri/ferrocyanide redox couple and its electrochemical behavior measured. Cyclic voltammograms (CVs) showed an enhanced redox potential for the MWCNT-Ti. These redox signals were superior to that obtained with bare unmodified Ti, which did not sense either oxidation or reduction peaks in the CVs. A further objective of this study was to investigate the redox reactions of MWCNT-Ti in a solution of extracellular components secreted by osteoblasts in vitro. It was found that MWCNT-Ti exhibited well-defined and persistent CVs, similar to the ferri/ferrocyanide redox reaction. The higher electrodic performance and electrocatalytic activity of the MWCNT-Ti compared to the bare titanium observed in this study were likely due to the fact that MWCNTs enhanced direct electron transfer and facilitated double-layer effects, leading to a strong redox signal. Thus these results encourage the further study and modification of MWCNT-Ti to sense new bone growth in situ next to orthopedic implants and perhaps monitor other events (such as infection and/or harmful scar tissue formation) to improve the current clinical diagnosis of orthopedic implants.

Sirivisoot, Sirinrath; Webster, Thomas J.

2008-07-01

24

In situ thermally enhanced biodegradation of petroleum fuel hydrocarbons and halogenated organic solvents  

Science.gov (United States)

An in situ thermally enhanced microbial remediation strategy and a method for the biodegradation of toxic petroleum fuel hydrocarbon and halogenated organic solvent contaminants are described. The method utilizes nonpathogenic, thermophilic bacteria for the thermal biodegradation of toxic and carcinogenic contaminants, such as benzene, toluene, ethylbenzene and xylenes, from fuel leaks and the chlorinated ethenes, such as trichloroethylene, chlorinated ethanes, such as 1,1,1-trichloroethane, and chlorinated methanes, such as chloroform, from past solvent cleaning practices. The method relies on and takes advantage of the pre-existing heated conditions and the array of delivery/recovery wells that are created and in place following primary subsurface contaminant volatilization efforts via thermal approaches, such as dynamic underground steam-electrical heating. 21 figs.

Taylor, R.T.; Jackson, K.J.; Duba, A.G.; Chen, C.I.

1998-05-19

25

Observations of in-situ generated gravity waves during a stratospheric temperature enhancement (STE event  

Directory of Open Access Journals (Sweden)

Full Text Available Observations of in-situ generated atmospheric gravity waves associated with a stratospheric temperature enhancement (STE are presented. Two sets of gravity waves are observed by molecular-aerosol lidar in conjunction with the early December 2000 STE event above Sondrestrom, Greenland. The first set of gravity waves shows downward phase progression with a vertical wavelength of ~8 km while the second set shows upward phase progression with a vertical wavelength of ~9 km. With estimates of the background wind fields from synoptic analyses, the various intrinsic gravity wave parameters of these two wave structures are found. The observed waves compare well to numerical modeling predictions, though the potential observation of a downward propagating wave would be unexpected.

A. J. Gerrard

2011-05-01

26

Broadband Cavity Enhanced Absorption Spectroscopy: an in-situ DOAS for Atmospheric Measurements  

Science.gov (United States)

From the processing of natural and anthropogenic emissions to the nucleation of new aerosol particles, tropospheric chemistry is driven by species present at trace concentrations. Field based observations provide the means to study complex trace gas processes in-situ, and advancements in understanding are often driven by developments in instrumentation that push forward the limits of sensitivity, target selectivity and deployment flexibility. In this work we present an ultra-sensitive optical instrument for quantification of a wide range of atmospheric trace gas components. The instrument is based upon a broadband variant of cavity enhanced absorption spectroscopy (BBCEAS) using high intensity light emitting diode sources, a short (1.1 m) high finesse optical cavity and wavelength resolved CCD detection. The BBCEAS approach enables measurements akin to those of traditional DOAS to be made in-situ and at high temporal resolution. This is important for the study of short lived species which show high spatial and temporal variability. In addition, the instrument offers deployment flexibility for field studies, being well suited for use on a range of platforms including aircraft, ships and vehicles. In this paper the instrument design and principles of operation will be described in detail, with particular attention being given to description of the calibration system. The performance of the instrument will be presented using results from a number of recent field and laboratory based studies. Most notably these include ppt level measurements of NO3 and N2O5 in coastal environments, ppt level detection of IO formed in reactor experiments from the oxidation of molecular iodine emitted from marine algae and lab based experiments showing sub ppb level detection of nitrous acid.

Langridge, J. M.; Le Crâne, J.; Ball, S. M.; Jones, R. L.

2007-12-01

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ENHANCED IN SITU BIOREMEDIATION DEMONSTRATED IN FRACTURED BEDROCK IN: GROUND WATER CURRENTS NEWSLETTER, ISSUE 38, P. 2-3, 2000  

Science.gov (United States)

The USEPA's SITE Program conducted a demonstration of the Enhanced In Situ Bioremediation Process at the ITT Industries Night Vision Facility in Roanoke, VA. The biostimulation process, developed by the USEOE and licensed to Earth Tech, Inc., involves injecting a mixture of air, ...

28

SITE DEMONSTRATION OF ENHANCED IN SITU BIOREMEDIATION OF CHLORINATED AND NON-CHLORINATED ORGANIC COMPOUNDS IN FRACTURED BEDROCK  

Science.gov (United States)

A field demonstration of an enhanced in situ bioremediation technology was conducted between March 1998 and August 1999 at the ITT Industries Nithg Vision (ITTNV) Division plant in Roanoke, Virginia. The bioremediation process was evaluated for its effectiveness in treating both ...

29

Research on preparation of Al-Fe-V-Si alloy enhanced by in-situ TiC particles  

Energy Technology Data Exchange (ETDEWEB)

Heat-resistant Al-Fe-V-Si aluminum alloys enhanced by in-situ TiC particles have been prepared by spray forming process with suitable process parameters. Research results show that the microstructure of as-deposited alloy is fine and homogeneous. In-situ TiC particles prevent the unsteady phases from coming into being. On the other hand, the TiC particles increase the volume fraction of heat-resistant phases. So the mechanical properties of the enhanced alloy by in-situ TiC particles are better than that of Al-Fe-V-Si alloy without TiC particles. The hot extrusion temperature is also an important parameter to understand. Under the permission, it is better to extrude the alloy at lower temperature. The tensile strength of the alloy without TiC particles is about 435 MPa at room temperature and is about 204 MPa at 350 C. However, when the alloy is enhanced by in-situ TiC particles, the strength of alloy is about 482 MPa at room temperature and is about 224 MPa at 350 C temperature. (orig.)

Baohong Zhu; Yong' an Zhang; Baiqing Xiong; Hongwei Liu; Likai Shi [National Engineering and Technology Research Center for Nonferrous MMCs, General Research Inst. for Nonferrous Metals, Beijing, BJ (China)

2005-07-01

30

Cupric oxide nanowires assembled by nanoparticles in situ with enhancing electrocatalytic oxidation of ascorbic acid  

Science.gov (United States)

CuO nanowires are facilely fabricated on the surface of AgCuZn alloy in situ by direct oxidation and partial reduction procedures, which shows an improved electrocatalytic activity toward ascorbic acid oxidation. The morphology shows the nanowires are assembled by CuO nanoparticles and we consider the process that the unordered spheres convert to ordered wires is due to the reduction of [1 1 0] and [ 1 bar ?? 1 ?? 1 ] crystal planes in CuO. Moreover, the prepared modified electrode displays a high sensitivity of 1660 ?A cm-2 mM-1, wide linear range from 0.1 ?M to 3.1 mM and a low detection limit of 0.095 ?mol (signal/noise = 3). Further, the sensor is also tested for anti-interferences and real samples determination, exhibiting distinguished selectivity, accuracy, and recovery. Such excellent properties are owing to the special structure of the synthesized CuO that would provide more specific surface area and enhanced activity compared with common nanowires. Hence, this work of fabricating CuO nanowires assembled by CuO nanoparticles with high performance might supply a way for facile obtain more electrochemical sensor in this structure.

Wang, Chuanxi; Liu, Jie; Huang, Xing; Wang, Huanhuan; Zheng, Youdan; Lin, Li; Wang, Siyu; Chen, Song; Jin, Yong

2014-02-01

31

Enhanced colorimetric detection on porous microarrays using in situ substrate production.  

Science.gov (United States)

A new technique is reported for the enhanced colorimetric detection of multiplexed hybridization onto porous membrane-based microarrays. This approach combines the use of horseradish peroxidase (HRP) as a label together with a chromogen substrate and a local production of the hydrogen peroxide required for substrate oxidation. This in situ production of coreagent is obtained using glucose oxidase (GOx) directly immobilized within the microarray porous membrane mesh. The oxidation of glucose by the immobilized GOx produces hydrogen peroxide which itself enables the oxidation of TMB (3,3',5,5'-tetramethylbenzidine) by HRP and yields a blue precipitate on positive spots. Thanks to a coreagent overconcentration within the membrane, this design drastically surpasses the performances of the standard TMB/H(2)O(2) kit used for peroxidase label detection. The obtained target limit of detection is then 50 times lower (20 pM) than the one obtained with the standard kit approach, and the dynamic range expands at least one decade. Furthermore, the developed method was shown to compete well with the widely used alkaline phosphatase-BCIP (5-bromo-4-chloro-3-indolyl phosphate)/NBT (nitro blue tetrazolium chloride) readout while minimizing background signal. The method was finally successfully applied to the multiplex detection of single nucleotide polymorphisms (SNPs) in complex PCR samples. The background lowering was impacted here positively on the SNPs' detection by increasing the complementary/noncomplementary signal ratio. PMID:21417414

Le Goff, Gaelle C; Blum, Loïc J; Marquette, Christophe A

2011-05-01

32

CO2 Storage and Enhance Gas Recovery from Shales: Insights from In Situ Experiments  

Science.gov (United States)

Recent developments in hydraulic fracturing technologies have provided a basis for dramatic increases in natural gas production from shale and tight gas reservoirs. GIS data analysis shows that approximately 60% of U.S. stationary CO2 emission sources are within 50 miles of a currently operating or potential shale gas play. Those emission sources represent a potential supply of CO2 to support enhanced gas recovery operations to extend the economic production life of these shale gas fields. Conservative estimates of the CO2 storage capacity in these depleted shale gas reservoirs are around 10 GtCO2 potentially producing up to an additional 100 Tcf of gas. Hence, there is a critical need to better understand the fundamental factors controlling CO2 storage and secondary gas production in shales. Mineralogy of shale formations are complicated, often times containing varying amounts of different clay minerals (illite, kaolinite, chlorite, and montmorillonite) carbonates (calcite, siderite, and dolomite), feldspar, quartz, gypsum, and pyrite. Interactions of these minerals with wet scCO2 are mostly unknown and will ultimately control injectivity, methane production, and CO2 storage capacity through mineral volume changes. To investigate the interactions between important clay minerals and wet scCO2, we have conducted a series of experiments exposing selected clay minerals to scCO2 containing variable amounts of dissolved water. Observations by in situ XRD indicate the montmorillonite structure contracts when in contact with dry scCO2. Expansion is observed when the same mineral is exposed to wet scCO2. Degrees of expansion and contraction are related to total dissolved water content in the scCO2 and the amount of water in the interlayer and type of interlayer cation. Other clays such as kaolinite, chlorite, and illite appear stable and undergo no observable structural change during exposure to scCO2. Experiments are in progress with in situ optical spectroscopic probes to distinguish between physisorption, swelling, and chemical reactions among the different shale components in wet scCO2 environments.

Schaef, T.; McGrail, P.; Miller, Q. R.; Glezakou, V.; Loring, J. S.

2012-12-01

33

Field test for treatment verification of an in-situ enhanced bioremediation study  

International Nuclear Information System (INIS)

Due to a leakage from a 12-inch pressurized diesel steel pipe four years ago, an area of approximately 30,000 square meters was contaminated. A pilot study applying the technology of in-situ enhanced bioremediation was conducted. In the study, a field test kit and on-site monitoring equipment were applied for site characterization and treatment verification. Physically, the enhanced bioremediation study consisted of an air extraction and air supply system, and a nutrition supply network. Certain consistent sampling methodology was employed. Progress was verified by daily monitoring and monthly verification. The objective of this study was to evaluate the capabilities of indigenous microorganisms to biodegrade the petroleum hydrocarbons with provision of oxygen and nutrients. Nine extraction wells and eight air sparging wells were installed. The air sparging wells injected the air into geoformation and the extraction wells provided the underground air circulation. The soil samples were obtained monthly for treatment verification by a Minuteman drilling machine with 2.5-foot-long hollow-stem augers. The samples were analyzed on site for TPH-diesel concentration by a field test kit manufactured by HNU-Hanby, Houston, Texas. The analytical results from the field test kit were compared with the results from an environmental laboratory. The TVPH concentrations of the air extracted from the vadose zone by a vacuum blower and the extraction wells were routinely monitored by aaction wells were routinely monitored by a Foxboro FID and Cosmos XP-311A combustible air detector. The daily monitoring of TVPH concentrations provided the reliable data for assessing the remedial progress

34

Photonic Crystal Biosensor with In-Situ Synthesized DNA Probes for Enhanced Sensitivity  

Energy Technology Data Exchange (ETDEWEB)

We report on a nearly 8-fold increase in multi-hole defect photonic crystal biosensor response by incorporating in-situ synthesis of DNA probes, as compared to the conventional functionalization method employing pre-synthesized DNA probe immobilization.

Hu, Shuren [Vanderbilt University, Nashville; Zhao, Y. [Vanderbilt University, Nashville; Retterer, Scott T [ORNL; Kravchenko, Ivan I [ORNL; Weiss, Sharon [Vanderbilt University, Nashville

2013-01-01

35

CNTs in situ attached to ?-Fe2O3 submicron spheres for enhancing lithium storage capacity.  

Science.gov (United States)

In this work, we developed a facile hydrothermal method for synthesis of hybrid ?-Fe2O3-carbon nanotubes (CNTs) architectures (?-Fe2O3-CNTs-1 and ?-Fe2O3-CNTs-2). The CNTs are in situ attached to the ?-Fe2O3 submicron spheres and form three-dimensional network robust architectures. The increase in the amount of CNTs in the network ?-Fe2O3-CNTs architectures will significantly enhance the cycling and rate performance, as the flexible and robust CNTs could ensure the fast electron transport pathways, enhance the electronic conductivity, and improve the structural stability of the electrode. As for pure ?-Fe2O3 submicron spheres, the capacity decreased significantly and retained at 377.4 mAh g(-1) after 11 cycles, and the capacity has a slightly increasing trend at the following cycling. In contrast, the network ?-Fe2O3-CNTs-2 electrode shows the most remarkable performance. At the 60th cycle, the capacity of network ?-Fe2O3-CNTs-2 (764.5 mAh g(-1)) is 1.78 times than that of ?-Fe2O3 submicron spheres (428.3 mAh g(-1)). The long-term cycling performance (1000 cycles) of samples at a high current density of 5 C showed that the capacity of ?-Fe2O3 submicron spheres fade to ?37.3 mAh g(-1) at the 400th cycle and gradually increased to ?116.7 mAh g(-1) at the 1000th cycle. The capacity of network ?-Fe2O3-CNTs-2 maintained at ?220.2 mAh g(-1) before the 400th cycle, arrived at ?326.5 mAh g(-1) in the 615th, cycle and retained this value until 1000th cycle. The network ?-Fe2O3-CNTs-2 composite could significantly enhance the cycling and rate performance than pure ?-Fe2O3 submicron spheres composite. PMID:25490394

Gao, Guo; Zhang, Qiang; Cheng, Xin-Bing; Qiu, Peiyu; Sun, Rongjin; Yin, Ting; Cui, Daxiang

2015-01-14

36

In-situ monitoring of potential enhanced DNA related processes using electrochemical quartz crystal microbalance with dissipation (EQCM-D)  

DEFF Research Database (Denmark)

The effect of applied potential pulses on DNA functionalization (thiolated single stranded DNA) and hybridization processes has been monitored in-situ on gold surfaces using electrochemical quartz crystal microbalance with dissipation (EQCM-D). The applied potentials were chosen with respect to the potential of zero charge (Epzc) of the gold surfaces: a positive potential to attract the negatively charged DNA molecules and a negative potential to enhance the vertical alignment due to electrostatic repulsion. The obtained results clearly show that both DNA modification and hybridization are strongly enhanced by applying potential pulses. Based on the EQCM-D results, we present a model to explain the influence of the potential pulsing. Aside fromthe effect of applied potentials on DNA related processes, this work also demonstrates the versatility of the combination of electrochemistry and quartz crystal microbalance with dissipation in facilitating real-time in situ monitoring of such processes.

Quan, Xueling; Heiskanen, Arto

2014-01-01

37

Force enhancement in lengthening contractions of cat soleus muscle in situ: transient and steady-state aspects  

OpenAIRE

Force enhancement (FE) associated with lengthening is a well-accepted phenomenon of active skeletal muscle, but the underlying mechanism(s) remain unknown. Similar to force depression (FD) following active shortening, the mechanism of FE may be attributed, at least in part, to cross-bridge kinetics. To examine this relationship, a post hoc analysis was performed on the transient force relaxation phase of previous in-situ FE experiments in soleus muscle-tendon units of anesthetized cats. For e...

Koppes, Ryan A.; Herzog, Walter; Corr, David T.

2013-01-01

38

Enhancing the mechanical properties of cement paste by growing in-situ fiber reinforcement during hydration  

Science.gov (United States)

Efforts to improve the mechanical properties of concrete by modifying the cement paste matrix have focused entirely on strength enhancement. But the intrinsic brittleness of the cement paste matrix limits the possible improvement in the mechanical properties of concrete, and in particular the toughness of the material. Increasing the toughness of the cement paste matrix could lead to a reduction in flaw sensitivity by delaying unstable crack propagation. Consequently, the resistance of the material to cracking due to drying shrinkage, thermal shrinkage, expansive deterioration processes, and applied loads could increase considerably. The goal of this study was to grow in-situ fiber reinforcement in cement paste, a technique never before applied to cement-based materials, to enhance the toughness of the material. Ettringite, an existing, fiber-like hydration product was selected as the fiber reinforcement. Ettringite met all the necessary criteria to act as reinforcement in cement paste: adequate distribution in the matrix; adjustable volume fraction, aspect ratio and size; high stiffness along the fiber length; and finally compatibility with existing hydration products. Alkali-free accelerators were selected as the admixtures used to grow the ettringite in the cement paste. X-ray diffraction and scanning electron microscopy experiments were performed to study the volume fraction, distribution, size, and morphology of the ettringite crystals in the cement paste matrix (both plain and accelerator-containing). Mechanical tests (compression, splitting tension, flexural, compact tension) were used to evaluate the effect of the accelerators on the strength and toughness of cement paste. Microindentations on the surface of the cement paste matrix were performed to study the morphology of the cracks and the toughening mechanisms taking place. Through the characterization tests we identified that while more ettringite forms with the addition of the alkali-free accelerators, some of that ettringite forms in highly-porous inclusions distributed throughout the matrix. The compact tension specimen results showed that the accelerated specimens had a higher toughness and ductility compared to the control specimens. The dominant toughening mechanism identified was constrained microcracking, with the ettringite inclusions contributing to microcracking.

Constantinides, Margarita

39

Enhanced utilization of oxidants for in situ chemical oxidation of chlorinated and aromatic hydrocarbons  

Science.gov (United States)

Potentially viable strategies were sought for enhanced utilization of potassium permanganate (KMnO4) and Fenton's reagent during in situ chemical oxidation (ISCO). An innovative concept of controlled release of oxidant was introduced and organic-coated, completely or partially microencapsulated KMnO4 (MEPP) particles (874 +/- 377 mum) were created to serve a material that can be specifically targeted to a contaminant source zone. Paraffin wax was employed as the coating material because it is biodegradable, inert to KMnO4, insoluble in water and yet soluble in hydrophobic contaminants such as perchloroethylene (PCE). KMnO4 was released very slowly into water, but the oxidant was rapidly released into PCE. The estimated times for 90% release of the oxidant were 1.6 months, 19.3 years, and 472 years for paraffin wax to KMnO4 mass ratios of 1:1, 2:1 and 5:1, respectively. The MEPP particles preferentially accumulated at the PCE-water interface, and the KMnO4 was rapidly released into PCE (aromatic hydrocarbons (benzene, toluene, ethylbenzene, and o-xylene; BTEX) present as dissolved and adsorbed phases, and chlorinated hydrocarbon (PCE) present mostly as dense non-aqueous phase liquid (DNAPL) (>93% of total PCE mass) in batch reactors (soil: solution = 1 g/L). An enhanced mass removal was observed by combining 300 mM H2O2, 2 mM Fe(III) and 2 mM N-(2-hydroxyethyl)iminodiacetic acid (HEIDA) at near-neutral pH. The PCE degradation was maximal at 600 mM H2O2, 5 mM Fe(III) and 5 mM HEIDA at pH 3. The observed BTEX mass removal rate constants (3.6--7.8 x 10-4 s-1) were compared to the estimated ones (4.1--10.1 x 10-3 s-1) using a semi-quantitative kinetic model. The model sensitivity analyses indicate that iron oxides and soil organic matter could play important roles in the non-specific losses of both H 2O2 and ·OH. These findings suggest that system design could be optimized with respect to process variables in remediation of contaminated soils and groundwater with Fenton's reagent.

Kang, Namgoo

40

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

Energy Technology Data Exchange (ETDEWEB)

The objective of this NETL sponsored bench-scale study was to demonstrate the efficacy of enhanced anaerobic reductive precipitation (EARP) technology for precipitating uranium using samples from contaminated groundwater at the Fernald Closure Project (FCP) in Cincinnati, Ohio. EARP enhances the natural biological reactions in the groundwater through addition of food grade substrates (typically molasses) to drive the oxidative-reductive potential of the groundwater to a lower, more reduced state, thereby precipitating uranium from solution. In order for this in-situ technology to be successful in the long term, the precipitated uranium must not be re-dissolved at an unacceptable rate once groundwater geochemical conditions return to their pretreatment, aerobic state. The approach for this study is based on the premise that redissolution of precipitated uranium will be slowed by several mechanisms including the presence of iron sulfide precipitates and coatings, and sorption onto fresh iron oxides. A bench-scale study of the technology was performed using columns packed with site soil and subjected to a continuous flow of uranium-contaminated site groundwater (476 {micro}g/L). The ''treated'' column received a steady stream of dilute food grade molasses injected into the contaminated influent. Upon attainment of a consistently reducing environment and demonstrated removal of uranium, an iron sulfate amendment was added along with the molasses in the influent solution. After a month long period of iron addition, the treatments were halted, and uncontaminated, aerobic, unamended water was introduced to the treated column to assess rebound of uranium concentrations. In the first two months of treatment, the uranium concentration in the treated column decreased to the clean-up level (30 {micro}g/L) or below, and remained there for the remainder of the treatment period. A brief period of resolubilization of uranium was observed as the treated column returned to aerobic conditions, but the concentration later returned to below the clean-up level. Speciation analysis was conducted on soil collected from the treated column after rebound testing. The experimental results show that: (a) The mass of uranium resolubilized in more than four months of column testing was much lower than the amount precipitated. (b) The majority of the uranium was precipitated in the first few inches of the treated column. The majority of the uranium precipitated was associated with iron oxides or in other immobile/sequestered phases. It is important to contrast this result with the results reported by Bryan (2003) who shows that most of the uranium associated with contaminated aquifer solids at Fernald under the existing natural attenuation/pump and treat with reinjection conditions is carbonate bound. Carbonate bound forms are traditionally seen as fairly mobile, but may not be under a calcite/dolomite saturated condition. Fernald is currently conducting further studies to investigate the mobility of the carbonate bound forms. (c) Though reoxidation concentrations from the bench-scale column exceeded 30 {micro}g/L for a time, they later returned to below this value. Effluent concentrations from the treated column are expected to over predict full-scale concentrations for reasons discussed in depth in the text. Finally, these results must be viewed in light of the site's ongoing pump-and-treat with reinjection system. There is reason to believe that although the pump-and-treat technology is currently effectively controlling the uranium plume and reducing the groundwater concentration, it may not be able to reach the treatment standard of 30 {micro}g/L within an economical operating lifetime and then maintain that concentration without rebound. This study suggests that Enhanced Anaerobic Reductive Precipitation can change the speciation and thus reduce the mobility of uranium at the site and expedite closure.

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

2003-08-01

41

Enhanced quantum yield of nitrogen fixation for hydrogen storage with in situ-formed carbonaceous radicals.  

Science.gov (United States)

NH3 is a potential hydrogen energy carrier. Here we use alcohols as hole scavengers to investigate the nitrogen photofixation mechanisms including direct and indirect electron transfer processes. The t-butanol system exhibited the highest quantum yield of 36.1%, ascribing to the in situ-formed indirect electronic transmitter ?CO2(-). PMID:25704549

Zhao, Weirong; Xi, Haiping; Zhang, Meng; Li, Yajun; Chen, Jinsheng; Zhang, Jing; Zhu, Xi

2015-03-01

42

In situ nitrogen-doped graphene grown from polydimethylsiloxane by plasma enhanced chemical vapor deposition  

Energy Technology Data Exchange (ETDEWEB)

Due to its unique electronic properties and wide spectrum of promising applications, graphene has attracted much attention from scientists in various fields. Control and engineering of graphene’s semiconducting properties is considered to be the key of its applications in electronic devices. Here, we report a novel method to prepare in situ nitrogen-doped graphene by microwave plasma assisted chemical vapor deposition (CVD) using PDMS (Polydimethylsiloxane) as a solid carbon source. Based on this approach, the concentration of nitrogen-doping can be easily controlled via the flow rate of nitrogen during the CVD process. X-ray photoelectron spectroscopy results indicated that the nitrogen atoms doped into graphene lattice were mainly in the forms of pyridinic and pyrrolic structures. Moreover, first-principles calculations show that the incorporated nitrogen atoms can lead to p-type doping of graphene. This in situ approach provides a promising strategy to prepare graphene with controlled electronic properties.

Wang, Chundong; Zhou, Yungang; He, Lifang; Ng, Tsz-Wai; Hong, Guo; Wu, Qi-Hui; Gao, Fei; Lee, Chun-Sing; Zhang, Wenjun

2013-01-21

43

JV Task 59-Demonstration of Accelerated In Situ Contaminant Degradation by Vacuum-Enhanced Nutrient Distribution  

Energy Technology Data Exchange (ETDEWEB)

The Energy & Environmental Research Center (EERC) conducted remediation of hydrocarbon-contaminated soils and groundwater at a former Mohler Oil site in Bismarck, North Dakota. The remedial strategy was based on the application of two innovative concepts: (1) design and deployment of the mobile extraction, treatment, and injection units to overcome site limitations associated with urban settings in high-traffic areas and (2) vacuum-controlled nutrient injection within and on the periphery of an induced hydraulic and pneumatic depression. Combined contaminant recovery since the beginning of the project in June 2003 totals over 13,600 lb ({approx}6,170 kg) of hydrocarbons, equivalent to 2176 gallons (8236 l) of product. In situ delivery of 1504 Ib (682 kg) of ionic nitrate and 540 Ib (245 kg) of dissolved oxygen translates into further reduction of about 489 Ib (222 kg) of benzene for the same period and provides for long-term stimulation of the natural attenuation process. In addition to contaminant recovered by extraction and reduced by in situ biodegradation, a total of 4136 Ib (1876 kg) of oxygen was delivered to the saturated zone, resulting in further in situ reduction of an estimated 1324 lb (600 kg) of dissolved-phase hydrocarbons. Based on the results of the EERC demonstration, the North Dakota Department of Health approved site abandonment and termination of the corrective action.

Jaroslav Solc

2007-03-15

44

Enhanced visible-light induced degradation of benzene on Mg-ferrite/hematite/PANI nanospheres: In situ FTIR investigation  

Energy Technology Data Exchange (ETDEWEB)

Graphical abstract: The dramatic enhanced visible-light photocatalytic activity of Mg-ferrite/hematite nanospheres photocatalyst on benzene were obtained after hybridized by polyaniline (PANI) using the chemisorption method. The enhancement of photocatalytic degradation of benzene under visible-light irradiation was mainly ascribed to the high efficiency of charge separation induced by the hybrid effect of PANI and Mg-ferrite/hematite. By using the in situ FTIR technique, ethyl acetate, carboxylic acid and aldehyde could be regarded as the intermediate products, and CO{sub 2} is produced as the final product during the reaction process. Highlights: Black-Right-Pointing-Pointer Mg-ferrite/hematite/PANI photocatalysts showed enhanced photocatalytic activity. Black-Right-Pointing-Pointer Ethyl acetate, carboxylic acid and aldehyde were the intermediate products. Black-Right-Pointing-Pointer CO{sub 2} was produced as the final product during the reaction process. Black-Right-Pointing-Pointer The high efficiency of charge separation was mainly ascribed to the hybrid effect. - Abstract: The dramatic enhanced visible-light photocatalytic activity of Mg-ferrite/hematite nanospheres photocatalysts on benzene were obtained after hybridized by polyaniline (PANI) using the chemisorption method. The samples were characterized by scanning electron microscope, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectra and UV-Vis diffuse reflectance spectroscopy. The enhancement of photocatalytic degradation of benzene under visible-light irradiation was mainly ascribed to the high efficiency of charge separation induced by the hybrid effect of PANI and Mg-ferrite/hematite. By using the in situ FTIR technique, ethyl acetate, carboxylic acid and aldehyde could be regarded as the intermediate products, and CO{sub 2} is determined as the final product during the reaction process.

Shen, Yu [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China); School of Environmental and Chemical Engineering, Dalian Jiaotong University, Dalian 116028 (China); Zhao, Qidong [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China); Li, Xinyong, E-mail: xyli@dlut.edu.cn [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China); Department of Chemical Engineering, Curtin University, Perth, WA 6845 (Australia); Yuan, Deling; Hou, Yang [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China); Liu, Shaomin, E-mail: shaomin.liu@curtin.edu.au [Department of Chemical Engineering, Curtin University, Perth, WA 6845 (Australia)

2012-11-30

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In situ synthesis of CoS2/RGO nanocomposites with enhanced electrode performance for lithium-ion batteries  

International Nuclear Information System (INIS)

Highlights: •CoS2/RGO was in situ synthesized by employing graphene oxides as oxidizer and Na2S2O3 as reductor. •The CoS2 particles of 150 nm were uniformly dispersed on the RGO nanosheets. •The enhanced properties can be attributed to the small particle size and the RGO networks. -- Abstract: This study reports a novel strategy of preparing CoS2/reduced graphene oxides (RGO) nanocomposites by employing graphene oxides (GO) as an oxidizing agent and Na2S2O3 as a reducing agent. CoS2 can be in situ synthesized with GO being reduced. X-ray diffraction (XRD), Raman spectrometry, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electrochemical test are used to characterize the nanocomposite. The CoS2 particles with the size of 150 nm are dispersed in the networks made from thin RGO nanosheets. The CoS2/RGO nanocomposite as an anode material for lithium-ion batteries can deliver excellent reversible capacity retention (640 mA hg?1) after cycling 50 times when tested at 100 mA g?1 and rate performance. The enhanced electrochemical properties can be attributed to the nanoscale particles sizes of CoS2 in addition to the effects of RGO networks in preventing the agglomeration of CoS2 and absorbing lithium polysulfides during the charge-discharge processes

46

Enhanced visible-light photocatalytic activities of Ag3PO4/MWCNT nanocomposites fabricated by facile in situ precipitation method  

International Nuclear Information System (INIS)

Highlights: • Ag3PO4/MWCNT composites were facilely fabricated via in situ precipitation method. • Ag3PO4/MWCNT composites exhibited enhanced visible-light photocatalytic activity. • Ag3PO4/MWCNT composites showed good photostability compared with Ag3PO4 particles. • Possible photocatalytic mechanism under visible-light irradiation was proposed. - Abstract: The Ag3PO4/MWCNT nanocomposites were facilely fabricated via in situ precipitation method by adding (NH4)2HPO4 into the mixture of multi-walled carbon nanotube (MWCNT) and AgNO3 solution under stirring. The as-prepared Ag3PO4/MWCNT nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), the Brunauer–Emmett–Teller surface area (BET) and UV–vis diffuse reflectance spectroscopy. The TEM results showed that the Ag3PO4 nanoparticles were distributed on the surface of MWCNT uniformly with an average diameter of 70 nm, indicating excellent loading result. The photocatalytic activities of Ag3PO4/MWCNT nanocomposites were investigated by degrading methylene blue (MB) and malachite green (MG) under visible-light irradiation. It was found that the Ag3PO4/MWCNT nanocomposite exhibited excellent photocatalytic performance with enhanced photocatalytic efficiency and good photostability compared with bare Ag3PO4. Furthermore, a possible mechanism for the photocatalytic oxidative degradation was also discussed

47

A capillary-based probe for in situ detection of enhanced fluorescence signals  

International Nuclear Information System (INIS)

A simple, compact, and high sensitivity capillary-based probe for the in situ detection of fluorescence signals with high sensitivity is demonstrated. A home-made single–multi-mode fiber coupler that is coaxially aligned with the capillary-based probe provides for the transmission of excitation light and the collection and transmission of fluorescence. We propose a conceptually straightforward theoretical model to optimize the factors affecting the fluorescence-capture capability of the capillary-based probe. The fluorescence signal detected by fiber-optic spectroscopy non-linearly increases with the length of the capillary-based probe. In addition, the thicker the capillary tube wall is, the less the fluorescence signals determined are. The performance of the proposed probe is evaluated experimentally by measuring the fluorescence spectra of Cy5.5 dye and blue-green algae. The experimental results show that the proposed probe provides more than a ten-fold increase in fluorescence signal compared with direct measurements by a flat-tipped multi-mode fiber probe. The advantages of the capillary-based probe, which include its simple and compact structure, excellent light collection efficiency, requirement of small sample volume, and recoverability of samples, allow its wide application to in situ detection in the medical, forensic, biological, geological, and environmental fields with high sensitivity. (letter)

48

In-situ rf plasma treatment of multi-wall carbon nanotubes with various reactive gases for enhanced field emission  

International Nuclear Information System (INIS)

Well-aligned multi-wall carbon nanotubes (MWNTs) were fabricated at a low temperature of 400 .deg. C by utilizing a radio-frequency plasma-enhanced chemical vapor deposition (rf-PECVD) system. The MWNTs were in-situ treated with external rf plasma sources, such as hydrogen (H2) and ammonia (NH3), in order to enhance the structural and electrical properties of the MWNTs. Structural properties of carbon nanotubes were investigated by using scanning electron microscopy, Fourier transform infrared spectroscopy, energy-dispersive spectrometry and transmission electron microscopy. Finally, the emission properties of the MWNTs treated with various gases were also measured, for application in field emission displays in the near future.

49

Comparison of 1 week versus 4 weeks of albendazole therapy in single small enhancing computed tomography lesion  

Directory of Open Access Journals (Sweden)

Full Text Available Background : The appropriate duration of albendazole therapy in neurocysticercosis is uncertain. The observation in small uncontrolled randomized trials in children that short-course therapy (1 week is as effective as the conventional regimen (4weeks must be tested. Objective : To compare the efficacy of 1 and 4 weeks of albendazole therapy in children with single small enhancing computed tomographic lesion (SSECTL. Study Design: An open-labeled, randomized, clinical trial. Materials and Methods : One hundred twenty children with SSECTLs presenting with seizure. Intervention: The subjects were assigned to two groups using random tables: group A (n=58 received albendazole for 1 week and group B (n=62 for 4 weeks. All the subjects were followed up for 6 months. Results : The proportions of subjects with complete resolution of lesion in the two groups were similar (group A 63.8% versus group B 51.6%. The proportion of subjects in the two groups in whom the lesion calcified on follow up (group A 19% versus group B 24.2% also did not differ significantly. The incidence of seizure recurrence during the 6-month follow-up period was also similar in both the groups (group A 9.6% versus group B 3.4%, P > 0.05. Conclusion : One week of albendazole therapy is as effective as 4 weeks of therapy in children with SSECTLs.

Kaur Prabhjeet

2010-01-01

50

FORMULATION AND EVALUATION OF SUMATRIPTAN SUCCINATE NASAL IN-SITU GEL USING FULVIC ACID AS NOVEL PERMEATION ENHANCER  

Directory of Open Access Journals (Sweden)

Full Text Available Sumatriptan succinate is a 5-HT1D (5-hydroxy tryptamine 1D-receptor agonist, used in the treatment of migraine and cluster headache Sumatriptan succinate has been shown to have a low oral bioavailability in human volunteers (15% because of high first pass metabolism.. Subcutaneous administration is an alternative; however, dislike of injections or inability to self-administer by this route makes subcutaneous treatment unacceptable to some individuals. These all above things justify a need of nasal drug delivery. To improve the nasal retention time of Sumatriptan succinate, it has been formulated as in situ mucoadhesive gel by using Pluronic PF127 and carbopol 974P. The objective of this work was to improve the nasal bioavailability of Sumatriptan succinate by increasing its nasal retention time as well as by means of nasal permeation. Nasal permeation of Sumatriptan succinate was improved by using fulvic acid extracted from Shilajit as a novel permeation enhancer. For the same the nasal in situ gel of Sumatriptan succinate and its complex with fulvic acid extracted from shilajit was made by cold method. The prepared in-situ gel was evaluated for gelation temperature, drug content, mucoadhesive force, gel strength and viscosity measurement. Further insitu gels prepared with and without permeation enhancer (Fulvic acid were evaluated for its In vitro drug diffusion study by Fran’s Diffusion Cell. The data of In vitro drug diffusion study of insitu gel prepared with and without permeation enhancer showed non Fickian or anomalous diffusion mechanism. The optimized batch C3 and F3 of insitu gel prepared with and without permeation enhancer respectively shows drug release in a controlled manner with higher permeation rate for 250min.. The drug permeation study across sheep nasal mucosa was conducted using C3 and F3 batch. The study showed that the insitu gel having fulvic acid have a significantly higher permeability as compared to the insitu gel which do not contain the fulvic acid. The higher permeation rate of C3 formulation as compare to F3 formulation is might be due to polymeric polyphenolic nature of fulvic acid because of which it have a tendency to interact with number of component resulting in higher permeation rate.

Shyam D. Badgujar

2010-10-01

51

Narrower grid structure of artificial reef enhances initial survival of in situ settled coral.  

Science.gov (United States)

The initial factors that cause a decline in the survival of in situ settled corals remain poorly understood. In this study, we demonstrated through field experiments that the design of artificial grid plates may influence the initial survival of Acropora corals, with narrower grids being the most effective. In fact, grid plates with a 2.5-cm mesh presented the highest recorded survival rate (14%) at 6 months after settlement (representing approximately 50 corals per 0.25 m(2) of plate). This is the first study where such high survival rates, matching those of cultures under aquarium conditions, were obtained in the field without using additional protective measures, such as guard nets against fish grazing after seeding. Therefore, our results provide a foundation for establishing new and effective coral restoration techniques for larval seeding, in parallel to clarifying the details of the early life stages of reef-building corals. PMID:21967865

Suzuki, Go; Kai, Sayaka; Yamashita, Hiroshi; Suzuki, Kiyoshi; Iehisa, Yukihiro; Hayashibara, Takeshi

2011-12-01

52

In-Situ resonance-enhanced multiphoton ionization (REMPI) measurements using an optical fiber probe  

International Nuclear Information System (INIS)

Two fiber-optic REMPI probes have been developed to determine the feasibility of using fiber-optics for in-situ determination of volatile organic compounds. In both designs, an optical fiber transmits a high-powered laser pulse to the sample, causing it to ionize, and the subsequent electrons are collected by a platinum electrode. One probe contains focusing optics while the other contains no focusing optics other than the fiber. Excitation using a 2+2 scheme was used for all measurements because visible excitation has optimal transmission of light through fiber-optics. The nonlensed probe was tested by measuring toluene and benzene and the response was compared to that using the lensed probe

53

In situ protein-DNA interactions at a dioxin-responsive enhancer associated with the cytochrome P1-450 gene.  

OpenAIRE

We used an in situ exonuclease III protection technique (C. Wu, Nature [London] 309:229, 1984) to analyze protein-DNA interactions at a dioxin-responsive enhancer. Our results imply that the 2,3,7,8-tetrachlorodibenzo-p-dioxin-receptor complex interacts with the dioxin-responsive enhancer to activate transcription of the cytochrome P1-450 gene.

Durrin, L. K.; Whitlock, J. P.

1987-01-01

54

In situ purity enhancement/surface modification of single-walled carbon nanotubes synthesized by induction thermal plasma  

Energy Technology Data Exchange (ETDEWEB)

A simple, cost-effective and energy-efficient approach was developed for in situ purity enhancement and surface modification of single-walled carbon nanotubes (SWCNTs) produced using an induction thermal plasma process. In this process, SWCNT-containing materials are thermally treated with oxygen flow inside a filtration chamber, while they are assembled into the sheets during the synthesis process. Owing to selective thermal oxidation, the amount of amorphous carbon was significantly reduced in the final product resulting in higher purity SWCNT-containing materials. Parametric study indicated that the amorphous carbon content was noticeably diminished in the product at an oxygen volume concentration of 10% in the synthesis system. Raman analysis indicated a decrease in the population of the SWCNTs with diameters smaller than 1.3 nm after in situ exposure to 10 vol.% of oxygen. In addition to the successful reduction of amorphous carbon content, the oxygen-functionalized SWCNTs were also observed in the final product using this process.

Shahverdi, Ali; Kim, Keun Su; Alinejad, Yasaman; Soucy, Gervais, E-mail: Gervais.Soucy@Usherbrooke.ca [Universite de Sherbrooke, Department of Chemical and Biotechnological Engineering (Canada)

2012-02-15

55

Enhancement in bioavailability of ketorolac tromethamine via intranasal in situ hydrogel based on poloxamer 407 and carrageenan.  

Science.gov (United States)

The objective of this study was to construct a new in situ gel system based on the combination of poloxamer 407 and carrageenan (carrageenan-poloxamer 407 hydrogel, CPH) for intranasal delivery of ketorolac tromethamine. CPH showed potassium ion concentration - dependent erosion characteristics which ensured slow erosion in aqueous environment containing potassium ion at the physiological level. Loading with ketorolac tromethamine influenced erosion, drug release and thermosensitive properties of CPH. CPH containing 15% ketorolac tromethamine showed suitable gelation temperature (near 35°C) and in vitro sustained release profiles. Pharmacokinetic study of intranasal CPH containing 15% ketorolac tromethamine in rats demonstrated enhanced absolute bioavailability (68.8 ± 23.3%) and prolonged mean residence time (8.8 ± 3.5h) in comparison with the intranasal solution group (24.8 ± 13.8%, 3.9 ± 0.6h). Nasal ciliotoxicity evaluation on an in situ toad palate model preliminarily showed the safety of CPH for intranasal use. All results suggested the potential of CPH as a new sustained - release platform for the intranasal delivery of ketorolac tromethamine. PMID:25138250

Li, Chenxi; Li, Chunyan; Liu, Zheshuo; Li, Qiuhong; Yan, Xueying; Liu, Yu; Lu, Weiyue

2014-10-20

56

Enhanced recovery programmes in colorectal surgery are less enhanced later in the week: An observational study  

Science.gov (United States)

Summary Objectives Since the introduction and favourable early results of the enhanced recovery programme more than a decade ago, it has become increasingly popular following major abdominal surgery. The programme has now been adopted in the UK. The aim of our study was to see if the day of surgery affected hospital stay and we compared patients who had colorectal surgery early in the week (Monday to Wednesday) with those who had it later in the week (Thursday to Friday). Design Patient outcomes were studied between May 2010 and April 2011 from a prospectively maintained database. All colorectal surgeons involved in the enhanced recovery programme in our unit have a flexible rota and so no surgeon was operating on a particular day to avoid bias. An enhanced recovery programme protocol was utilised for all the patients with no bowel preparation, early feeding and early mobilisation. Setting Study was carried out at the University Hospitals of Leicester. Participants Patients undergoing elective colorectal resection between Monday and Friday. Main outcome measure Hospital stay. Results Two hundred and twenty-seven patients underwent surgery and were on the enhanced recovery programme during this period. Two (0.9%) patients who had surgery on a Sunday were excluded. Two hundred and twenty-five patients were analysed of which 155 (69%) were in the group (Monday to Wednesday) and 70 (31%) in the group (Thursday to Friday). No significant differences were observed amongst the groups for age (p?=?0.129), sex (p?=?0.555), tumour location (p?=?0.140), operation performed (p?=?0.127), type of surgery (laparoscopy or open, p?=?0.892), complications (p?=?0.428). However, a significant shorter length of stay was present in the first group six days (interquartile range: 4–10) versus eight days (interquartile range: 5–11) (p?=?0.045). Conclusion Operating on colorectal patients early in the week is associated with a significant decreased hospital stay. This should be put into consideration by units practising enhanced recovery programme if the maximal benefit of this is to be attained. PMID:25780591

Esmail, Faatimah; Lloyd, G; Miller, Andrew; Singh, Baljit; Chaudhri, Sanjay

2015-01-01

57

Semi-continuous in situ magnetic separation for enhanced extracellular protease productionmodeling and experimental validation  

DEFF Research Database (Denmark)

In modern biotechnology proteases play a major role as detergent ingredients. Especially the production of extracellular protease by Bacillus species facilitates downstream processing because the protease can be directly harvested from the biosuspension. In situ magnetic separation (ISMS) constitutes an excellent adsorptive method for efficient extracellular protease removal during cultivation. In this work, the impact of semi?continuous ISMS on the overall protease yield has been investigated. Results reveal significant removal of the protease from Bacillus licheniformis cultivations. Bacitracin?functionalized magnetic particles were successfully applied, regenerated and reused up to 30 times. Immediate reproduction of the protease after ISMS proved the biocompatibility of this integrated approach. Six subsequent ISMS steps significantly increased the overall protease yield up to 98% because proteolytic degradation and potential inhibition of the protease in the medium could be minimized. Furthermore, integration of semi?continuous ISMS increased the overall process efficiency due to reduction of the medium consumption. Process simulation revealed a deeper insight into protease production, and was used to optimize ISMS steps to obtain the maximum overall protease yield. Biotechnol. Bioeng. 2013; 110: 2161–2172. © 2013 Wiley Periodicals, Inc.

Cerff, M.; Scholz, A.

2013-01-01

58

Development of ultrafine Ti-Fe-Sn in-situ composite with enhanced plasticity  

Science.gov (United States)

The present investigation is aimed at developing ultrafine eutectic/dendrite Ti-Fe-Sn in-situ composite with balanced combination of strength and plasticity. It also studies the microstructure evolution in the series of hypereutectic Ti-Fe-Sn ternary alloys. Sn concentration of these alloys has been varied from 0 - 10 atom% in the binary alloy (Ti71Fe29) keeping the Ti concentration fixed. These alloys have been prepared by arc melting under an Ar atmosphere on a water-cooled Cu hearth, which are subsequently suction cast in a split Cu-mold under an Ar atmosphere. Detailed X-ray diffraction (XRD) study shows the presence of TiFe, ?-Ti, and Ti3Sn phases. The SEM micrographs reveal that the microstructures consist of fine scale eutectic matrix (?-Ti and TiFe) with primary dendrite phases (TiFe and/or Ti3Sn) depending on concentration of Sn. ? -Ti forms as a eutectoid reaction product of ?-Ti. The room temperature uniaxial compressive test reveals simultaneous improvement in the strength (1942 MPa) and plasticity (13.1 %) for Ti71Fe26Sn3 ternary alloy. The fracture surface indicates a ductile mode of fracture for the alloy.

Mondal, B.; Samal, S.; Biswas, K.; Govind

2012-01-01

59

Enhancing RHIC luminosity capabilities with in-situ beam piple coating  

Energy Technology Data Exchange (ETDEWEB)

Electron clouds have been observed in many accelerators, including the Relativistic Heavy Ion Collider (RHIC) at the Brookhaven National Laboratory (BNL). They can limit the machine performance through pressure degradation, beam instabilities or incoherent emittance growth. The formation of electron clouds can be suppressed with beam pipe surfaces that have low secondary electron yield. At the same time, high wall resistivity in accelerators can result in levels of ohmic heating unacceptably high for superconducting magnets. This is a concern for the RHIC machine, as its vacuum chamber in the superconducting dipoles is made from relatively high resistivity 316LN stainless steel. The high resistivity can be addressed with a copper (Cu) coating; a reduction in the secondary electron yield can be achieved with a titanium nitride (TiN) or amorphous carbon (a-C) coating. Applying such coatings in an already constructed machine is rather challenging. We started developing a robotic plasma deposition technique for in-situ coating of long, small diameter tubes. The technique entails fabricating a device comprised of staged magnetrons and/or cathodic arcs mounted on a mobile mole for deposition of about 5 {micro}m (a few skin depths) of Cu followed by about 0.1 {micro}m of TiN (or a-C).

Herschcovitch,A.; Blaskiewicz, M.; Fischer, W.; Poole, H. J.

2009-05-04

60

Oxygen-enhanced in situ bioremediation in a sand and gravel aquifer  

International Nuclear Information System (INIS)

In situ bioremediation was chosen to remediate shallow oxygen-limited groundwater contaminated with volatile and semivolatile aromatic hydrocarbons from a fuel release. The remediation system included groundwater recovery at rates up to 100 L/min and treatment with a packed-tower air stripper to remove volatiles and increase dissolved oxygen levels. Dissolved oxygen was further increased using a pressure-swing adsorption (PSA) oxygen generator and hollow-fiber oxygen dissolution membranes. This oxygenated water was injected back to the subsurface through two horizontal injection galleries. Prior to start-up of the remediation system, groundwater in contaminated wells was oxygen-limited, with levels from 0 to less than 1 mg/L. After several months of groundwater injection, dissolved oxygen levels began to increase in contaminated wells by 1 to 2 mg/L. A significant decrease in dissolved-phase hydrocarbons was observed in a well nearest an injection gallery once dissolved oxygen was increased to background levels. A decrease in nitrogen was also observed, suggesting that aerobic biodegradation was a significant factor in the hydrocarbon decrease

61

In-situ hybridization of calcium silicate and hydroxyapatite-gelatin nanocomposites enhances physical property and in vitro osteogenesis.  

Science.gov (United States)

Low mechanical strengths and inadequate bioactive material-tissue interactions of current synthetic materials limit their clinical applications in bone regeneration. Here, we demonstrate gelatin modified siloxane-calcium silicate (GEMOSIL-CS), a nanocomposite made of gelatinous hydroxyapatite with in situ pozzolanic formation of calcium silicate (CS) interacting among gelatin, silica and Calcium Hydroxide (Ca(OH)2). It is shown the formation of CS matrices, which chemically bonds to the gelatinous hydroxyapatite, provided hygroscopic reinforcement mechanism and promoted both in vitro and in vivo osteogenic properties of GEMOSIL-CS. The formation of CS was identified by Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction. The interfacial bindings within nanocomposites were studied by FTIR and thermogravimetric analysis. Both gelatin and CS have been found critical to the structure integrity and mechanical strengths (93 MPa in compressive strength and 58.9 MPa in biaxial strength). The GEMOSIL-CS was biocompatible and osteoconductive as result of type I collagen secretion and mineralized nodule formation from MC3T3 osteoblasts. SEM and TEM indicated the secretion of collagen fibers and mineral particles as the evidence of mineralization in the early stage of osteogenic differentiation. In vivo bone formation capability was performed by implanting GEMOSIL-CS into rat calvarial defects for 12 weeks and the result showed comparable new bone formation between GEMOSIL-CS group (20%) and the control (20.19%). The major advantage of GEMOSIL-CS composites is in situ self-hardening in ambient or aqueous environment at room temperature providing a simple, fast and cheap method to produce porous scaffolds. PMID:25649517

Chiu, Chi-Kai; Lee, Dong Joon; Chen, Hsin; Chow, Laurence C; Ko, Ching-Chang

2015-02-01

62

Silver-enhanced in situ hybridization for determination of EGFR copy number alterations in non-small cell lung cancer.  

Science.gov (United States)

Epidermal growth factor receptor (EGFR) gene mutation and high gene copy number (CN) predict response to EGFR tyrosine kinase inhibitor therapy in the adenocarcinoma subtype of non-small cell lung cancer (NSCLC). The aims of this study were first to compare automated enzyme metallographic silver-enhanced in situ hybridization (SISH) with conventionally used fluorescence in situ hybridization (FISH) in the determination of EGFR CN in NSCLC tissue sections, and second to assess the association of EGFR CN with EGFR mutations and clinicopathological parameters. FISH and SISH were performed on tissue microarrays and large sections. Samples from 56 consecutively surgically resected NSCLC patients (cohort 1) and from 60 selected lung adenocarcinoma patients (cohort 2) were analyzed. EGFR CN was classified applying the Colorado criteria, and agreement between both methods was evaluated using ? values. EGFR CN was compared with EGFR protein expression and EGFR gene mutations. The results of SISH and FISH were identical in 114 of the 116 cases examined using the 2 techniques. One case was FISH+, SISH-, and 1 case was FISH- and SISH+. The agreement between the 2 methods was good in cohort 1 (?=0.642 [0.428, 0.823]) and excellent in cohort 2 (?=0.963 [0.870, 1.000]). EGFR positivity by FISH and SISH was associated with high EGFR protein expression (P<0.001) and EGFR mutation (P<0.001). These results validate the use of SISH for assessing EGFR CN alterations in NSCLC. The advantage of a permanent result and the possibility of bright-field microscopy make SISH an attractive alternative to FISH. PMID:23154768

Wulf, Marie-Angela; Bode, Beata; Zimmermann, Dieter; Rufibach, Kaspar; Weder, Walter; Moch, Holger; Soltermann, Alex; Tischler, Verena

2012-12-01

63

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

64

In situ fabrication of 3D Ag@ZnO nanostructures for microfluidic surface-enhanced Raman scattering systems.  

Science.gov (United States)

In this work, we develop an in situ method to grow highly controllable, sensitive, three-dimensional (3D) surface-enhanced Raman scattering (SERS) substrates via an optothermal effect within microfluidic devices. Implementing this approach, we fabricate SERS substrates composed of Ag@ZnO structures at prescribed locations inside microfluidic channels, sites within which current fabrication of SERS structures has been arduous. Conveniently, properties of the 3D Ag@ZnO nanostructures such as length, packing density, and coverage can also be adjusted by tuning laser irradiation parameters. After exploring the fabrication of the 3D nanostructures, we demonstrate a SERS enhancement factor of up to ?2×10(6) and investigate the optical properties of the 3D Ag@ZnO structures through finite-difference time-domain simulations. To illustrate the potential value of our technique, low concentrations of biomolecules in the liquid state are detected. Moreover, an integrated cell-trapping function of the 3D Ag@ZnO structures records the surface chemical fingerprint of a living cell. Overall, our optothermal-effect-based fabrication technique offers an effective combination of microfluidics with SERS, resolving problems associated with the fabrication of SERS substrates in microfluidic channels. With its advantages in functionality, simplicity, and sensitivity, the microfluidic-SERS platform presented should be valuable in many biological, biochemical, and biomedical applications. PMID:25402207

Xie, Yuliang; Yang, Shikuan; Mao, Zhangming; Li, Peng; Zhao, Chenglong; Cohick, Zane; Huang, Po-Hsun; Huang, Tony Jun

2014-12-23

65

In-situ administration of dendritic cells following argon-helium cryosurgery enhances specific antiglioma immunity in mice.  

Science.gov (United States)

Dendritic cells (DCs) are highly specialized antigen-presenting cells that play a key role in the activation of naive T cells. With an aim to explore whether in-situ administration of DCs following argon-helium cryosurgery could enhance specific antiglioma immunity in mice, we evaluated the validity of this approach in a murine subcutaneous GL261 glioma model. C57BL/6 mice models bearing subcutaneous GL261 glioma were established and then divided into four groups, namely, no-treatment group (n=14), DC group (n=14), cryosurgery group (n=15), and cryosurgery+DC group (n=15). Compared with the other groups, cryosurgery combined with DCs injection reduced tumor sizes and significantly prolonged survival. In addition, the combined treatment resulted in significantly increasing percentages of CD3, CD3CD4 cells, the ratio of CD3CD4/CD3CD8, and the level of serum interleukin-12 10 days after treatments. Furthermore, in the combined treatment group, Th1 cells were significantly higher than those in the other groups, and the splenic cytotoxic T lymphocyte of mice showed significantly increasing specific cytotoxicity against GL261 cells. These results indicated that in addition to the destruction of tumor, cryosurgery combined with DCs injection enhanced systemic antitumor immunity, suggesting the potential usefulness of the combined treatment in the clinical management of gliomas. PMID:24942351

Lin, Chunnan; Wang, Qifu; Lu, Guohui; Yin, Zhilin; He, Xiaozheng; Xu, Hongchao; Pan, Jun; Zhang, Shizhong

2014-08-20

66

Enhanced photoelectrochemical performance of WO3/Ti photoanode due to in situ formation of a thin interfacial composite layer  

Science.gov (United States)

Nanostructured WO3 thin films were prepared on titanium sheet substrates using a doctor blade technique. X-ray diffraction, Raman and field emission scanning electron microscopy studies revealed that the synthesized WO3 films are having monoclinic crystal structure, porous, polycrystalline with average grain size of ?50 nm. The photoelectrochemical responses of WO3 films prepared on treated Ti sheets were recorded in 0.5 M H2SO4 electrolyte under simulated 100 mW/cm2 illumination. WO3 film prepared on polished Ti sheet showed considerable enhancement in photocurrent as compared to WO3 films made on unpolished and pre-oxidized Ti sheets. These results suggest that in situ formation of a thin WOx-TiOy interfacial composite layer and improved adhesion of WO3 nanoparticles owing to increased reactive sites on polished Ti substrate play a significant role in enhancing the photoresponse. Such photoanodes are potential candidates in photoelectrochemical water splitting system for hydrogen generation.

Lee, Won Jae; Shinde, Pravin S.; Go, Geun Ho; Doh, Chil Hoon

2013-04-01

67

Enhanced photoelectrochemical performance of WO3/Ti photoanode due to in situ formation of a thin interfacial composite layer  

International Nuclear Information System (INIS)

Nanostructured WO3 thin films were prepared on titanium sheet substrates using a doctor blade technique. X-ray diffraction, Raman and field emission scanning electron microscopy studies revealed that the synthesized WO3 films are having monoclinic crystal structure, porous, polycrystalline with average grain size of ?50 nm. The photoelectrochemical responses of WO3 films prepared on treated Ti sheets were recorded in 0.5 M H2SO4 electrolyte under simulated 100 mW/cm2 illumination. WO3 film prepared on polished Ti sheet showed considerable enhancement in photocurrent as compared to WO3 films made on unpolished and pre-oxidized Ti sheets. These results suggest that in situ formation of a thin WOx–TiOy interfacial composite layer and improved adhesion of WO3 nanoparticles owing to increased reactive sites on polished Ti substrate play a significant role in enhancing the photoresponse. Such photoanodes are potential candidates in photoelectrochemical water splitting system for hydrogen generation.

68

Adhesion enhancement of biomimetic dry adhesives by nanoparticle in situ synthesis  

International Nuclear Information System (INIS)

A novel method to increase the adhesion strength of a gecko-inspired dry adhesive is presented. Gold nanoparticles are synthesized on the tips of the microfibrils of a polymeric dry adhesive to increase its Hamaker constant. Formation of the gold nanoparticles is qualitatively studied through a colour change in the originally transparent substance and quantitatively analysed using ultraviolet–visible spectrophotometry. A pull-off force test is employed to quantify the adhesion enhancement. Specifically, adhesion forces of samples with and without embedded gold nanoparticles are measured and compared. The experimental results indicate that an adhesion improvement of 135% can be achieved. (paper)

69

In situ observation and enhancement of leaflet tissue formation in bioprosthetic "biovalve".  

Science.gov (United States)

Biovalves, autologous tri-leaflet valved conduits, are formed in the subcutaneous spaces of animals. The valves are formed using molds encapsulated with autologous connective tissues. However, tissue migration into the small apertures in the molds for leaflet formation is generally slower than that for conduit formation around the molds. In this study, the formation of the leaflet tissues was directly and non-invasively observed using a wireless capsule endoscope. The molds were assembled from 6 parts, one of which was impregnated with the endoscope, and embedded into subcutaneous pouches in goats (n = 30). Tissue ingrowth into the apertures gradually occurred from the edges of the leaflet parts. Tissue formation was accompanied by capillary formation. At 63.1 ± 17.1 days after embedding, the apertures were completely replaced with autologous connective tissue, forming the leaflet tissues. Leaflet formation was enhanced by including fat tissue (46.7 ± 4.2 days) or blood (41.1 ± 6.9 days) in the apertures before embedding. The creation of slit openings, in conjunction with addition of blood to the apertures, further enhanced leaflet formation (37.0 ± 2.8 days). Since leaflet formation could be observed endoscopically, the appropriate embedding period for complete biovalve formation could be determined. PMID:25370717

Funayama, Marina; Takewa, Yoshiaki; Oie, Tomonori; Matsui, Yuichi; Tatsumi, Eisuke; Nakayama, Yasuhide

2015-03-01

70

Application of steam injection and electrical heating for enhanced in situ soil and ground water treatment  

International Nuclear Information System (INIS)

The acceleration of recovery rates of second phase liquid contaminants from the subsurface during gas or water pumping operations is realized by an increase in soil temperature. Of the various methods of delivery of thermal energy to soils and ground water, steam injection appears to be the most economical and versatile technique for soils with sufficient permeability. The use of steam injection to recovery volatile semivolatile, and nonvolatile contaminants from the sub-surface also allows the exploitation of various thermodynamic and hydrodynamic mechanisms. These mechanisms include vaporization of liquids with boiling points below that of water, enhanced evaporation rates of semivolatile components, physical displacement of low viscosity liquids, dilution and displacement of aqueous contaminants, and removal of residual contaminants from low permeability zones by depressurization and vacuum drying. Electrical heating provides a means of preferentially heating the low permeability zones. A recently completed field-scale demonstration of the patented combined steam injection and electrical heating enhanced extraction technology (Dynamic Underground Stripping) to remove gasoline at a site at Lawrence Livermore National Laboratory confirms the effectiveness of this technique and its applicability to contaminants found above and below the water table

71

In-situ evaluation of enhanced heat transfer tubes for surface condenser  

International Nuclear Information System (INIS)

35 integral low-finned 'SC tube' tubes and the same number of plain tubes were installed in six sections of a condenser of the 500 MW unit; along three steam flows (downward, horizontal and upward) in two zones (outer-laned and close-packed). In the five sections except for the outer-laned zone along the downward steam flow (i.e., the upper and outer portion of the bundle), SC tubes were appreciably more insusceptible to condensate inundation than the plain tubes, and outerperformed the plain tubes with the enhancement ratios of 107% to 125% for the heat load of SC/Plain. In the outer-laned zone along the downward steam flow, large steam velocity presumably can create significant shear force on the condensate and strip it away, resulting in little difference between SC and the plain tubes. (author)

72

In situ stimulation vs. bioaugmentation: Can microbial inoculation of plant roots enhance biodegradation of organic compounds?  

Energy Technology Data Exchange (ETDEWEB)

The use of plant roots and their associated rhizosphere bacteria for biocontainment and biorestoration offers several advantages for treating soil-dispersed contaminants and for application to large land areas. Plant roots function as effective delivery systems, since root growth transports bacteria vertically and laterally along the root in the soil column (see [ 1,2]). Movement of microbes along roots and downward in the soil column can be enhanced via irrigation [1-4]. For example, Ciafardini et al. [3] increased the nodulation and the final yield of soybeans during pod filling by including Bradyrhizobium japonicum in the irrigation water. Using rhizosphere microorganisms is advantageous for biodegradation of compounds that are degraded mainly by cometabolic processes, e.g., trichloroethylene (TCE). The energy source for bacterial growth and metabolism is supplied by the plant in the form of root exudates and other sloughed organic material. Plants are inexpensive, and by careful choice of species that possess either tap or fibrous root growth patterns, they can be used to influence mass transport of soil contaminants to the root surface via the transpiration stream [5]. Cropping of plants to remove heavy metals from contaminated soils has been proposed as a viable, low-cost, low-input treatment option [6]. The interest in use of plants as a remediation strategy has even reached the popular press [7], where the use of ragweed for the reclamation of sites contaminated with tetraethyl lead and other heavy metals was discussed.

Kingsley, M.T.; Metting, F.B. Jr.; Fredrickson, J.K. [Pacific Northwest Lab., Richland, WA (United States); Seidler, R.J. [Environmental Protection Agency, Corvallis, OR (United States). Environmental Research Lab.

1993-06-01

73

In Situ Detection and Identification of Hair Dyes Using Surface-Enhanced Raman Spectroscopy (SERS).  

Science.gov (United States)

Hair is one of the most common types of physical evidence found at a crime scene. Forensic examination may suggest a connection between a suspect and a crime scene or victim, or it may demonstrate an absence of such associations. Therefore, forensic analysis of hair evidence is invaluable to criminal investigations. Current hair forensic examinations are primarily based on a subjective microscopic comparison of hair found at the crime scene with a sample of suspect's hair. Since this is often inconclusive, the development of alternative and more-accurate hair analysis techniques is critical. In this study, we utilized surface-enhanced Raman spectroscopy (SERS) to demonstrate that artificial dyes can be directly detected on hair. This spectroscopic technique is capable of a confirmatory identification of analytes with single molecule resolution, requires minimal sample, and has the advantage of fluorescence quenching. Our study reveals that SERS can (1) identify whether hair was artificially dyed or not, (2) determine if a permanent or semipermanent colorants were used, and (3) distinguish the commercial brands that are utilized to dye hair. Such analysis is rapid, minimally destructive, and can be performed directly at the crime scene. This study provides a novel perspective of forensic investigations of hair evidence. PMID:25635868

Kurouski, Dmitry; Van Duyne, Richard P

2015-03-01

74

Elicitation and in situ adsorption enhanced secondary metabolites production of Tripterygium wilfordii Hook. f. adventitious root fragment liquid cultures in shake flask and a modified bubble column bioreactor.  

Science.gov (United States)

The experiments of elicitation and in situ adsorption were conducted in shake flasks and then tested in a modified bubble column bioreactor for enhancing the productions of three active metabolites in Tripterygium wilfordii Hook. f., triptolide, wilforgine and wilforine. Methyl jasmonate was screened out as the elicitor and the non-ionic polymeric ion-exchange resin of Amberlite(®) XAD-7 was used for in situ product removal and protecting the alkaloids from degradation in the medium. In shake flask experiments, 3.55-fold, 49.11-fold, and 10.40-fold of triptolide, wilforgine, and wilforine, respectively, could be recovered from the medium and XAD-7 resin by elicitation and in situ product removal, compared with the control. The modified 10 L bubble column bioreactor had similar productions of the three active metabolites but needed a further optimization of parameters for better growth of adventitious roots. PMID:23943048

Miao, G P; Zhu, C S; Yang, Y Q; Feng, M X; Ma, Z Q; Feng, J T; Zhang, X

2014-04-01

75

In Situ Normoxia Enhances Survival and Proliferation Rate of Human Adipose Tissue-Derived Stromal Cells without Increasing the Risk of Tumourigenesis  

Science.gov (United States)

Adipose tissue-derived stromal cells (ASCs) natively reside in a relatively low-oxygen tension (i.e., hypoxic) microenvironment in human body. Low oxygen tension (i.e., in situ normoxia), has been known to enhance the growth and survival rate of ASCs, which, however, may lead to the risk of tumourigenesis. Here, we investigated the tumourigenic potential of ASCs under their physiological condition to ensure their safe use in regenerative therapy. Human ASCs isolated from subcutaneous fat were cultured in atmospheric O2 concentration (21% O2) or in situ normoxia (2% O2). We found that ASCs retained their surface markers, tri-lineage differentiation potential, and self-renewal properties under in situ normoxia without altering their morphology. In situ normoxia displayed a higher proliferation and viability of ASCs with less DNA damage as compared to atmospheric O2 concentration. Moreover, low oxygen tension significantly up-regulated VEGF and bFGF mRNA expression and protein secretion while reducing the expression level of tumour suppressor genes p16, p21, p53, and pRb. However, there were no significant differences in ASCs telomere length and their relative telomerase activity when cultured at different oxygen concentrations. Collectively, even with high proliferation and survival rate, ASCs have a low tendency of developing tumour under in situ normoxia. These results suggest 2% O2 as an ideal culture condition for expanding ASCs efficiently while maintaining their characteristics. PMID:25615717

Choi, Jane Ru; Pingguan-Murphy, Belinda; Wan Abas, Wan Abu Bakar; Yong, Kar Wey; Poon, Chi Tat; Noor Azmi, Mat Adenan; Omar, Siti Zawiah; Chua, Kien Hui; Xu, Feng; Wan Safwani, Wan Kamarul Zaman

2015-01-01

76

Strong enhancement of trace mercury removal from aqueous solution with sodium thiosulfate by in situ formed Mn-(hydr)oxides.  

Science.gov (United States)

The effect of sodium thiosulfate (Na2S2O3) on trace mercury removal from aqueous solution by in situ MnOx was investigated. Removal efficiency was studied at different molar ratios of Na2S2O3/Mn (0, 0.264, 0.593 and 1.582) and under changes in Mn dosage, reaction time and pH conditions. Additionally, the ionic strength and the mercury removal amount were examined to evaluate the efficiency of trace mercury removal. The results indicated that the presence of thiosulfate clearly improved removal of mercury from solution, and that increases in the ionic strength enhanced removal in a certain range of thiosulfate concentration. At neutral conditions, the mercury removal amount reached to maximum of 64 ?g/mg. It is proposed that the ability of thiosulfate to reduce some MnOx to Mn(2+) as well as transfer the uncharged mercury species to a negatively charged species [Formula: see text] improved trace mercury removal. The mechanism analysis revealed that ternary complexes or large aggregations may be formed because of surface complexation or electrostatic attraction. PMID:25086412

Lu, Xixin; Huangfu, Xiaoliu; Zhang, Xiang; Wang, Yaan; Ma, Jun

2014-11-15

77

In situ growing directional spindle TiO2 nanocrystals on cellulose fibers for enhanced Pb(2+) adsorption from water.  

Science.gov (United States)

TiO2/cellulose nanocomposite was synthesized by in situ generation of titanium dioxide (TiO2) nanocrystals on cellulose fibers (CF) via facile hydrolysis of TiOSO4. Cellulose was intended as a scaffold to immobilize TiO2 nanoparticles (NPs), but turned out surprisingly to be also a chemical template that directed the crystal growth. As a result, spindle rutile TiO2 crystals were nicely formed on the surface of cellulose. These crystals were further controlled to disperse uniformly without agglomeration for better use of their surface area to adsorb heavy metals. The TiO2/CF composite showed enhanced adsorption capacity, good regenerability and selectivity for lead (Pb(2+)) removal. In addition, the composite fibers were readily fabricated into a nonwoven filter bed through which dynamic filtration experiment was conducted. A 12-fold increase in filtered bed volume was achieved for TiO2/CF bed compared with pure CF bed before breakthrough took place. This work provides a green pathway for fabricating low cost, high efficiency and engineering application possible nanosorbents for water decontamination. PMID:25723888

Li, Yanxiang; Cao, Lixia; Li, Lei; Yang, Chuanfang

2015-05-30

78

A pilot test of passive oxygen release for enhancement of in situ bioremediation of BTEX-contaminated ground water  

International Nuclear Information System (INIS)

A pilot-scale field demonstration of the use of Oxygen Release Compound trademark (ORC) was conducted at the site of a former gasoline service station. ORC was installed into a barrier consisting of a tight pattern of treatment wells located relatively near the apparent source of hydrocarbon contamination. The purpose of the barrier was to enhance in situ biodegradation of BTEX in ground water by the passive release of oxygen from the unpumped treatment wells placed across the migration path of the plume. Detailed monitoring was carried out using fencelines of multilevel monitoring wells located up- and downgradient of the barrier. Total BTEX concentrations influent to the barrier were found to be highly variable in space and time. Total influent BTEX concentrations averaged on a cross section transverse to flow were less variable over time, ranging from 10 to 16 mg/L. Significant decreases in BTEX mass flux through the zone impacted by the treatment wells were observed. For the entire portion of the plume impacted by the treatment wells, estimated BTEX treatment efficiency was approximately 70% on Day 51 of the test and declined thereafter

79

In situ surface enhanced Raman spectroscopic studies of solid electrolyte interphase formation in lithium ion battery electrodes  

Science.gov (United States)

The use of surfaced-enhanced Raman spectroscopy (SERS) in lithium-ion battery (LIB) and Li-O2 battery studies has proven to be a powerful tool for observing solid electrolyte interphase (SEI) growth, on the electrode's surface, that is crucial in determining the battery's electrochemical performance. Here, we report the use of SiO2-coated Au nanoparticles for in situ SERS studies during electrochemical cycling to directly observe SEI formation on the electrode. The comparison of silicon electrodes with and without the electrolyte additive vinylene carbonate (VC) shows the formation of VC-related reduction products on the electrode's surface before the reduction of ethylene carbonate. Further observation, using normal Raman and SERS, of the silicon band intensity shows different amorphization rates between bulk and surface. These successful proof-of-concept experiments should allow this technique to be extended to other electrode material studies in conjunction with other surface sensitive techniques to further our understanding of surface reactions that heavily influence overall battery performance.

Hy, Sunny; Felix; Chen, Yi-Hsiu; Liu, Jyong-yue; Rick, John; Hwang, Bing-Joe

2014-06-01

80

Assessment of ALK Rearrangement in Non-small Cell Lung Cancer: Using Enhancing Immunohistochemical Way and Fluorescence in situ Hybridization  

Directory of Open Access Journals (Sweden)

Full Text Available Background and objective Besides epidermal growth factor receptor (EGFR mutation, the non-small cell lung cancer (NSCLC of anaplastic lymphoma kinase (ALK rearrangement becomes another important clinical subtype. A specific and high-sensitive and economical detection way is convenience for identification of ALK positive NSCLC quickly and accurately. So the objective of our research is to detect ALK rearrangement in 172 cases of NSCLC by using enhancing immunohistochemical way (ventana-IHC, V-IHC. Methods ALK rearrangement in 172 NSCLC samples was detected by using V-IHC, and positive staining cases were further verified by fluorescence in situ hybridization (FISH. Results Among 172 NSCLC cases, there were 12 positive staining. The positive results were confirmed by FISH and 11 cases were FISH positive. The overall concordance between V-IHC and FISH is 91.7% (11/12. Conclusion The V-IHC method is a reliable method for ALK arrangement and could be used in clinical screen and diagnosis.

Hui MENG

2015-02-01

81

Direct observation of hydrogen-enhanced plasticity in super duplex stainless steel by means of in situ electrochemical methods  

International Nuclear Information System (INIS)

In situ electrochemical hydrogen charging in combination with atomic force microscopy and optical microscopy has been used to study the effect of hydrogen on the austenite phase in super duplex stainless steel. Observations showed that hydrogen charging results in an irreversible deformation of austenite. High residual tensile stresses form in austenite during quench annealing. These stresses, in combination with the activation of dislocation sources by hydrogen, result in formation of slip lines on the austenite surface during in situ hydrogen charging.

82

In situ growth of a ZnO nanowire network within a TiO{sub 2} nanoparticle film for enhanced dye-densitized solar cell performance  

Energy Technology Data Exchange (ETDEWEB)

ZnO nanowire networks featuring excellent charge transport and light scattering properties are grown in situ within TiO{sub 2} films. The resultant TiO{sub 2}/ZnO composites, used as photoanodes, remarkably enhance the overall conversion efficiency of dye-sensitized solar cells (DSSCs) by 26.9%, compared to that of benchmark TiO{sub 2} films. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Bai, Yang; Yu, Hua; Li, Zhen; Lu, Gao Qing [Max; Wang, Lianzhou [ARC Centre of Excellence for Functional Nanomaterials, School of Chemical Engineering, The University of Queensland, Brisbane, QLD 4072 (Australia); Amal, Rose [ARC Centre of Excellence for Functional Nanomaterials, School of Chemical Engineering, The University of New South Wales, Sydney, NSW 2052 (Australia)

2012-11-14

83

In situ growth of a ZnO nanowire network within a TiO(2) nanoparticle film for enhanced dye-sensitized solar cell performance.  

Science.gov (United States)

ZnO nanowire networks featuring excellent charge transport and light scattering properties are grown in situ within TiO(2) films. The resultant TiO(2) /ZnO composites, used as photoanodes, remarkably enhance the overall conversion efficiency of dye-sensitized solar cells (DSSCs) by 26.9%, compared to that of benchmark TiO(2) films. PMID:22930471

Bai, Yang; Yu, Hua; Li, Zhen; Amal, Rose; Lu, Gao Qing Max; Wang, Lianzhou

2012-11-14

84

Rutile-structured TiO{sub 2} deposited by plasma enhanced atomic layer deposition using tetrakis(dimethylamino)titanium precursor on in-situ oxidized Ru electrode  

Energy Technology Data Exchange (ETDEWEB)

In this work, tetrakis(dimethylamino)titanium precursor as well as in-situ oxidized ruthenium bottom electrode were used to grow rutile-structured titanium dioxide thin layers by plasma enhanced atomic layer deposition. Metal–insulator–metal capacitors have been elaborated in order to study the electrical properties of the device. It is shown that this process leads to devices exhibiting excellent results in terms of dielectric constant and leakage current.

Pointet, John; Gonon, Patrice; Latu-Romain, Lawrence; Bsiesy, Ahmad, E-mail: Ahmad.Bsiesy@cea.fr; Vallée, Christophe [Microelectronics Technology Laboratory (LTM), Joseph Fourier University (UJF) and French National Center for Scientific Research - CNRS, CEA – LETI MINATEC, 17 Avenue des Martyrs, 38054 Grenoble Cedex 9 (France)

2014-01-15

85

Rutile-structured TiO2 deposited by plasma enhanced atomic layer deposition using tetrakis(dimethylamino)titanium precursor on in-situ oxidized Ru electrode  

International Nuclear Information System (INIS)

In this work, tetrakis(dimethylamino)titanium precursor as well as in-situ oxidized ruthenium bottom electrode were used to grow rutile-structured titanium dioxide thin layers by plasma enhanced atomic layer deposition. Metal–insulator–metal capacitors have been elaborated in order to study the electrical properties of the device. It is shown that this process leads to devices exhibiting excellent results in terms of dielectric constant and leakage current

86

Enhanced hydrogen embrittlement of Pd-coated niobium metal membrane detected by in situ small punch test under hydrogen permeation  

International Nuclear Information System (INIS)

The hydrogen embrittlement of pure niobium metal membrane was investigated under a hydrogen atmosphere by using a newly developed in situ small punch apparatus. The boundary for the ductile-to-brittle transition of the palladium-coated pure niobium was determined from a series of the in situ small punch tests. The measured boundary was found to be shifted greatly to the lower hydrogen content region as compared to that of palladium non-coated niobium membrane. The present result will provide us a clue to the design of niobium-based permeable membrane against the hydrogen embrittlement

87

Enhanced hydrogen embrittlement of Pd-coated niobium metal membrane detected by in situ small punch test under hydrogen permeation  

Energy Technology Data Exchange (ETDEWEB)

The hydrogen embrittlement of pure niobium metal membrane was investigated under a hydrogen atmosphere by using a newly developed in situ small punch apparatus. The boundary for the ductile-to-brittle transition of the palladium-coated pure niobium was determined from a series of the in situ small punch tests. The measured boundary was found to be shifted greatly to the lower hydrogen content region as compared to that of palladium non-coated niobium membrane. The present result will provide us a clue to the design of niobium-based permeable membrane against the hydrogen embrittlement.

Nambu, T. [Department of Materials Science and Engineering, Suzuka National College of Technology, Shiroko-cho, Suzuka, Mie 510-0294 (Japan)], E-mail: nambu@mse.suzuka-ct.ac.jp; Shimizu, K.; Matsumoto, Y. [Department of Mechanical Engineering, Oita National College of Technology, Maki, Oita 870-0151 (Japan); Rong, R.; Watanabe, N.; Yukawa, H.; Morinaga, M. [Department of Materials Science and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Yasuda, I. [Technology Research Institute, Tokyo Gas Co. Ltd., 1-16-25 Shibaura, Minato-ku, Tokyo 105-0023 (Japan)

2007-10-31

88

In-situ treatment of a mixed hydrocarbon plume through enhanced bio-remediation and a PRB system  

International Nuclear Information System (INIS)

Groundwater is frequently polluted with mixtures of contaminants that are amenable to different types of remediation. One example is the combination of petroleum hydrocarbons (BTEX) and chlorinated solvents (PCE, TCE, DCE, VC), as it occurs in the groundwater beneath the industrial site that is the objective of the present case study. The site is located in Italy near a main river (Arno), which is supposed to be the final recipient of the contamination and where a possible exposure might take place. The aim of the treatment is the plume containment within the site boundaries in order to avoid further migration of the contaminants towards the river. The design of the remediation system was based on an extensive site characterization that included - but was not limited to - the following information: geological and geochemical, microbiological and hydrological data, together with analytical data (i.e. contaminant concentrations). Pilot tests were also implemented in order to collect the necessary parameters for the full-scale treatment design and calibration. The monitoring of the site conditions was carried out throughout a period of several months, both with periodical measurements and sampling and with fixed monitoring probes, in order to record the aquifer changes (levels, concentrations, etc.) related both to seasonal variations and to the pilot tests. The groundwater is located in a highly heterogeneous aquifer, with a saturated thickness of 1.5 m and an average hurated thickness of 1.5 m and an average hydraulic conductivity of 2.5 x 10-5 m/s. The seepage velocity is extremely low, with a mean value around 1.3 mm/d. This results in a long residence time and limited volumes per time unit to be treated. The site was contaminated by a mixed plume of more than 15 different contaminants, ranging from BTEX, to MTBE, to PAH, to chlorinated solvents. The concentration peaks were in the order of 1-100 mg/l for each contaminant. Petroleum hydrocarbons are quickly degradable through oxidative mechanisms (especially aerobic biodegradation), whereas fully-chlorinated compounds are only biodegradable via reductive pathways. Therefore, a mixed plume of both types of contaminants requires a combined approach with the application of different treatment technologies. The remediation strategy elaborated combines an enhanced bio-remediation of the hot spots with a permeable reactive barrier (PRB) in a funnel and gate configuration for the down-gradient plume containment. Pilot tests were carried out in order to assess the efficiency and feasibility of such technologies in the site of interest. The enhanced bio-remediation is going to be carried out by means of injections of hydrogen release compounds (HRC) and oxygen release compounds (ORC) for the biodegradation of chlorinated solvents and petroleum hydrocarbons respectively. A pilot test was conducted to determine the degradation rates of the different contaminants. The pilot test was monitored with a periodic sampling and analysis of the groundwater and with a continuous monitoring of the physical-chemical parameters (temperature, pH, conductivity, redox potential and dissolved oxygen) in the monitoring wells placed immediately down-gradient of the injection points. The tests showed the possibility to use the enhanced bio-remediation with the double aim to reduce the hot spot concentrations, in order to lower the contaminant load on the PRB, and to control the lateral spreading of the plume in the side regions. Permeable reactive barriers are passive groundwater treatment systems that are able to decontaminate groundwater as it flows through a permeable treatment medium under natural gradients. The main advantage of this technology over ex-situ and other in-situ groundwater remediation approaches is the reduced operation- and maintenance costs. For the permeable reactive barrier, a funnel and gate configuration was selected. This system uses low permeability materials (funnel) to direct groundwater towards a permeable treatment zone (gate). To ensure that flow beneath the system doe

89

Enhanced and sustained topical ocular delivery of cyclosporine A in thermosensitive hyaluronic acid-based in situ forming microgels  

OpenAIRE

Yijun Wu, Jing Yao, Jianping Zhou, Fatima Zohra Dahmani State Key Laboratory of Natural Medicines, China Pharmaceutical University, Tongjiaxiang, Nanjing, People’s Republic of China Abstract: For nearly a decade, thermoresponsive ophthalmic in situ gels have been recognized as an interesting and promising ocular topical delivery vehicle for lipophilic drugs. In this study, a series of thermosensitive copolymers, hyaluronic acid-g-poly(N-isopropylacrylamide) (HA-g-PNIPAAm), was synthesiz...

Wu Y; Yao J.; Zhou J.; Fz, Dahmani

2013-01-01

90

X-231A demonstration of in-situ remediation of DNAPL compounds in low permeability media by soil fracturing with thermally enhanced mass recovery or reactive barrier destruction  

Energy Technology Data Exchange (ETDEWEB)

The overall goal of the program of activities is to demonstrate robust and cost-effective technologies for in situ remediation of DNAPL compounds in low permeability media (LPM), including adaptations and enhancements of conventional technologies to achieve improved performance for DNAPLs in LPM. The technologies sought should be potential for application at simple, small sites (e.g., gasoline underground storage tanks) as well as at complex, larger sites (e.g., DOE land treatment units). The technologies involved in the X-231A demonstration at Portsmouth Gaseous Diffusion Plant (PORTS) utilized subsurface manipulation of the LPM through soil fracturing with thermally enhanced mass recovery or horizontal barrier in place destruction. To enable field evaluation of these approaches, a set of four test cells was established at the X-231A land treatment unit at the DOE PORTS plant in August 1996 and a series of demonstration field activities occurred through December 1997. The principal objectives of the PORTS X-231A demonstration were to: determine and compare the operational features of hydraulic fractures as an enabling technology for steam and hot air enhanced soil vapor extraction and mass recovery, in situ interception and reductive destruction by zero valent iron, and in situ interception and oxidative destruction by potassium permanganate; determine the interaction of the delivered agents with the LPM matrix adjacent to the fracture and within the fractured zone and assess the beneficial modifications to the transport and/or reaction properties of the LPM deposit; and determine the remediation efficiency achieved by each of the technology strategies.

Siegrist, R.L. [Oak Ridge National Lab., TN (United States)]|[Colorado School of Mines, Golden, CO (United States). Environmental Science and Engineering Div.; Lowe, K.S. [Oak Ridge National Lab., Grand Junction, CO (United States). Life Sciences Div.; Murdoch, L.D. [FRx, Inc., Cincinnati, OH (United States)]|[Clemson Univ., SC (United States); Slack, W.W. [FRx, Inc., Cincinnati, OH (United States); Houk, T.C. [Lockheed Martin Energy Systems, Piketon, OH (United States)

1998-03-01

91

In situ innovator  

Energy Technology Data Exchange (ETDEWEB)

Neil Edmunds, vice president of enhanced oil recovery for Laricina Energy Ltd has applied the principles of genetics to reservoir engineering by programming a genetic algorithm which produces digital chromosomes. The company has applied this genetic optimization to solvent processes which Edmunds thinks could transform in situ oilsands production. All the processes are encoded with their variables and price per barrel as fitness score. By applying mathematics in the lab, it is hoped industry can save time in the field.

McKenzie-Brown, Peter

2011-06-15

92

In situ induced metal-enhanced fluorescence: A new strategy for biosensing the total acetylcholinesterase activity in sub-microliter human whole blood.  

Science.gov (United States)

Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities (i.e., total AChE) in human blood are biomarkers for theranostic monitoring of organophosphate neurotoxin-poisoned patients. We developed an ultra-sensitive method to detect the total AChE activity in sub-microliter human whole blood based on in situ induced metal-enhanced fluorescence (MEF). Both AChE and BChE can catalyze the hydrolysis of the acetylthiocholine (ATCh) substrate and produce positively-charged thiocholine (TCh). TCh can reverse the negatively-charged surface of core-shell Ag@SiO2 nanoparticles (NPs). The negatively-charged fluorescent dye (8-hydroxypyrene-1,3,6-trisulfonic acid, HPTS) is then confined to the surface of Ag@SiO2 NPs and generates an enhanced fluorescence signal in situ. Changes in the surface charge of Ag@SiO2 NPs are monitored by Zeta potential, and the MEF effect is confirmed by the measurements of fluorescence time decay. AChE activity has a dynamic range of 0U/mL to 0.005U/mL and a detection limit of 0.05mU/mL. The total AChE activity in the sub-microliter human whole blood could be determined; the results were further validated. Therefore, combining the AChE catalytic reaction with MEF provides a simple, ultra-sensitive, and cost-effective "in situ MEF" approach to determine the total AChE activity in human whole blood sample down to sub-microliters without matrix interferences. The strategy also allows potential usage in other tissues and other fields. PMID:25660508

Ma, KeKe; Lu, Lu; Qi, Zongli; Feng, Jingjing; Zhuo, Caixia; Zhang, Yaodong

2015-06-15

93

Enhancement of biodiesel production from marine alga, Scenedesmus sp. through in situ transesterification process associated with acidic catalyst.  

Science.gov (United States)

The aim of this study was to increase the yield of biodiesel produced by Scenedesmus sp. through in situ transesterification by optimizing various process parameters. Based on the orthogonal matrix analysis for the acidic catalyst, the effects of the factors decreased in the order of reaction temperature (47.5%) > solvent quantity (26.7%) > reaction time (17.5%) > catalyst amount (8.3%). Based on a Taguchi analysis, the effects of the factors decreased in the order of solvent ratio (34.36%) > catalyst (28.62%) > time (19.72%) > temperature (17.32%). The overall biodiesel production appeared to be better using NaOH as an alkaline catalyst rather than using H2SO4 in an acidic process, at 55.07 ± 2.18% (based on lipid weight) versus 48.41 ± 0.21%. However, in considering the purified biodiesel, it was found that the acidic catalyst was approximately 2.5 times more efficient than the alkaline catalyst under the following optimal conditions: temperature of 70 °C (level 2), reaction time of 10 hrs (level 2), catalyst amount of 5% (level 3), and biomass to solvent ratio of 1 : 15 (level 2), respectively. These results clearly demonstrated that the acidic solvent, which combined oil extraction with in situ transesterification, was an effective catalyst for the production of high-quantity, high-quality biodiesel from a Scenedesmus sp. PMID:24689039

Kim, Ga Vin; Choi, Woonyong; Kang, Dohyung; Lee, Shinyoung; Lee, Hyeonyong

2014-01-01

94

Rates and Mechanisms of Mineral Carbonation in Peridotite: Natural Processes and Recipes for Enhanced, in situ CO2 Capture and Storage  

Science.gov (United States)

Near-surface reaction of CO2-bearing fluids with silicate minerals in peridotite and basalt forms solid carbonate minerals. Such processes form abundant veins and travertine deposits, particularly in association with tectonically exposed mantle peridotite. This is important in the global carbon cycle, in weathering, and in understanding physical-chemical interaction during retrograde metamorphism. Enhancing the rate of such reactions is a proposed method for geologic CO2 storage, and perhaps for direct capture of CO2 from near-surface fluids. We review, synthesize, and extend inferences from a variety of sources. We include data from studies on natural peridotite carbonation processes, carbonation kinetics, feedback between permeability and volume change via reaction-driven cracking, and proposed methods for enhancing the rate of natural mineral carbonation via in situ processes ("at the outcrop") rather than ex situ processes ("at the smokestack").

Kelemen, Peter B.; Matter, Juerg; Streit, Elisabeth E.; Rudge, John F.; Curry, William B.; Blusztajn, Jerzy

2011-05-01

95

Enhanced water window x-ray emission from in situ formed carbon clusters irradiated by intense ultra-short laser pulses  

Energy Technology Data Exchange (ETDEWEB)

Enhanced water window x-ray emission (23–44 Å) from carbon clusters, formed in situ using a pre-pulse, irradiated by intense (I > 10{sup 17} W/cm{sup 2}) ultra-short laser pulse, is demonstrated. An order of magnitude x-ray enhancement over planar graphite target is observed in carbon clusters, formed by a sub-ns pre-pulse, interacting with intense main pulse after a delay. The effect of the delay and the duration of the main pulse is studied for optimizing the x-ray emission in the water window region. This x-ray source has added advantages of being an efficient, high repetition rate, and low debris x-ray source.

Chakravarty, U.; Rao, B. S.; Arora, V.; Upadhyay, A.; Singhal, H.; Naik, P. A.; Chakera, J. A.; Mukherjee, C.; Gupta, P. D. [Raja Ramanna Centre for Advanced Technology, Indore, 452 013 Madhya Pradesh (India)

2013-07-29

96

Enhanced water window x-ray emission from in situ formed carbon clusters irradiated by intense ultra-short laser pulses  

International Nuclear Information System (INIS)

Enhanced water window x-ray emission (23–44 Å) from carbon clusters, formed in situ using a pre-pulse, irradiated by intense (I > 1017 W/cm2) ultra-short laser pulse, is demonstrated. An order of magnitude x-ray enhancement over planar graphite target is observed in carbon clusters, formed by a sub-ns pre-pulse, interacting with intense main pulse after a delay. The effect of the delay and the duration of the main pulse is studied for optimizing the x-ray emission in the water window region. This x-ray source has added advantages of being an efficient, high repetition rate, and low debris x-ray source

97

Template-directed in situ polymerization preparation of nanocomposites of PEDOT:PSS-coated multi-walled carbon nanotubes with enhanced thermoelectric property.  

Science.gov (United States)

A template-directed in situ polymerization preparation of nanocomposites of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)-coated multi-walled carbon nanotubes (MWCNTs) with greatly enhanced thermoelectric property is presented. The results reveal that monomeric 3,4-ethylenedioxythiophene was successfully polymerized, enwrapping the surfaces of dispersed MWCNTs (templates) with the aid of PSS. The coated morphology was directly observed by high-resolution transmission electron microscopy. The coated layer was further characterized by energy-dispersive X-ray spectroscopy and X-ray diffraction. In addition, the interfacial interaction between PEDOT:PSS and MWCNTs was studied by Fourier transform infrared spectroscopy. Finally, the thermoelectric measurements show that the obtained PEDOT:PSS/MWCNT nanocomposites exhibited greatly enhanced electrical conductivities, Seebeck coefficients, and power factors when compared with those of neat PEDOT:PSS. PMID:25339220

Zhang, Zhuang; Chen, Guangming; Wang, Hanfu; Li, Xin

2015-01-01

98

Enhanced electron emission from carbon nanotubes through density control using in situ plasma treatment of catalyst metal  

International Nuclear Information System (INIS)

We controlled the density of carbon nanotubes (CNTs) through in situ NH3 plasma pretreatment and investigated field emission properties with the density variation. Ni catalytic layer was transformed into small nanoparticles with NH3 plasma pretreatment time and power. As NH3 plasma pretreatment time was increased, the growth rate of grown CNTs was gradually decreased. Also, the density of CNTs reduced from 2x109 to 8x106/cm2 with an increase in NH3 plasma pretreatment time from 10 to 30 min for the Ni layer of 10 Aa. With a decrease in the density of CNTs, the emission current density was increased and turn on electric field was decreased. We obtained large and uniform emission current (about 9 mA/emission area of 0.49 cm2) from CNTs film with the density of 8x106/cm2

99

In situ polymerization of graphene oxide and cyanate ester-epoxy with enhanced mechanical and thermal properties  

Science.gov (United States)

Uniformly dispersed graphene oxide (GO)/cyanate ester (CE)-epoxy (EP) composites were successfully synthesized by in situ polymerization. Both the results of FT-IR and XPS verified that epoxide groups on the GO sheets reacted with cyanate group (Osbnd Ctbnd N) in the resin. These results could provide excellent dispersion of GO and strong interfacial interaction between GO and CE matrix. TEM confirmed that GO tended to be a single layer. XRD and SEM indicated that matrix molecules could be inserted into the interplanar spacing of GO. The mechanical properties and thermal behavior of the composites were investigated in detail. It is observed that GO reinforced EP-CE composites demonstrated improved mechanical properties and better thermal stability than that of EP-CE matrix, which make them suitable for use in aerospace applications and structural composites.

Ren, Fang; Zhu, Guangming; Ren, Penggang; Wang, Yongkun; Cui, Xiaoping

2014-10-01

100

Tunable near infrared to ultraviolet upconversion luminescence enhancement in (?-NaYF4 :Yb,Tm)/CaF2 core/shell nanoparticles for in situ real-time recorded biocompatible photoactivation.  

Science.gov (United States)

A family of upconverting nanoparticles (UCNPs) with a tunable UV enhancement is developed via a facile approach. The design leads to a maximum 9-fold enhancement in comparison with known optimal ?-phase core/shell UCNPs in water. A highly effective and rapid in situ real-time live-cell photoactivation is recorded for the first time with such nanoparticles. PMID:23696330

Shen, Jie; Chen, Guanying; Ohulchanskyy, Tymish Y; Kesseli, Samuel J; Buchholz, Steven; Li, Zhipeng; Prasad, Paras N; Han, Gang

2013-10-11

101

In situ vertical profiles of aerosol extinction, mass, and composition over the southeast United States during SENEX and SEAC4RS: observations of a modest aerosol enhancement aloft  

Science.gov (United States)

Vertical profiles of submicron aerosol over the southeastern United States (SEUS) during the summertime from in situ aircraft-based measurements were used to construct aggregate profiles of chemical, microphysical, and optical properties. Shallow cumulus convection was observed during many profiles. These conditions enhance vertical transport of trace gases and aerosol and create a cloudy transition layer on top of the sub-cloud mixed layer. The trace gas and aerosol concentrations in the transition layer were modeled as a mixture with contributions from the mixed layer below and the free troposphere above. The amount of vertical mixing, or entrainment of air from the free troposphere, was quantified using the observed mixing ratio of carbon monoxide (CO). Although the median aerosol mass, extinction, and volume decreased with altitude in the transition layer, they were ~10% larger than expected from vertical mixing alone. This enhancement was likely due to secondary aerosol formation in the transition layer. Although the transition layer enhancements of the particulate sulfate and organic aerosol (OA) were both similar in magnitude, only the enhancement of sulfate was statistically significant. The column integrated extinction, or aerosol optical depth (AOD), was calculated for each individual profile, and the transition layer enhancement of extinction typically contributed less than 10% to the total AOD. Our measurements and analysis were motivated by two recent studies that have hypothesized an enhanced layer of secondary organic aerosol (SOA) aloft to explain the summertime enhancement of AOD (2-3 times greater than winter) over the southeastern United States. In contrast to this hypothesis, the modest enhancement we observed in the transition layer was not dominated by OA and was not a large fraction of the summertime AOD.

Wagner, N. L.; Brock, C. A.; Angevine, W. M.; Beyersdorf, A.; Campuzano-Jost, P.; Day, D. A.; de Gouw, J. A.; Diskin, G. S.; Gordon, T. D.; Graus, M. G.; Huey, G.; Jimenez, J. L.; Lack, D. A.; Liao, J.; Liu, X.; Markovic, M. Z.; Middlebrook, A. M.; Mikoviny, T.; Peischl, J.; Perring, A. E.; Richardson, M. S.; Ryerson, T. B.; Schwarz, J. P.; Warneke, C.; Welti, A.; Wisthaler, A.; Ziemba, L. D.; Murphy, D. M.

2015-02-01

102

Performance enhancement among adolescent players after 10 weeks of pitching training with appropriate baseball weights.  

Science.gov (United States)

Compared with regulation-weight baseballs, lightweight baseballs generate lower torque on the shoulder and elbow joints without altering the pitching movement and timing. This study investigates the throwing accuracy, throwing velocity, arm swing velocity, and maximum shoulder external rotation (MSER) of adolescent players after 10 weeks of pitching training with appropriate lightweight baseballs. We assigned 24 adolescent players to a lightweight baseball group (group L) and a regulation-weight baseball group (group R) based on their pretraining throwing velocity. Both groups received pitching training 3 times per week for 10 weeks with 4.4- and 5-oz baseballs. The players' throwing accuracy, throwing velocity, arm swing velocity, and MSER were measured from 10 maximum efforts throws using a regulation-weight baseball before and after undergoing the pitching training. The results showed that the players in group L significantly increased their throwing velocity and arm swing velocity (p pitching training with the 4.4-oz baseball, whereas group R did not (p > 0.05). Furthermore, the percentage change in the throwing velocity and arm swing velocity of group L was significantly superior to that of group R (p pitching training with an appropriate lightweight baseball substantially enhanced the arm swing velocity and throwing velocity of the adolescent baseball players. These findings suggest that using a lightweight baseball, which can reduce the risk of injury without altering pitching patterns, has positive training effects on players in the rapid physical growth and technique development stage. PMID:23603999

Yang, Wen-Wen; Liu, Ya-Chen; Lu, Lee-Chang; Chang, Hsiao-Yun; Chou, Paul Pei-Hsi; Liu, Chiang

2013-12-01

103

In situ spectroscopic ellipsometry growth studies on the Al-doped ZnO films deposited by remote plasma-enhanced metalorganic chemical vapor deposition  

International Nuclear Information System (INIS)

In situ spectroscopic ellipsometry (SE) was applied to study the pyramidlike and pillarlike growth of Al doped ZnO (AZO) films deposited by means of remote plasma-enhanced metalorganic chemical vapor deposition for transparent conductive oxide applications. Real time SE studies in the visible region allowed discerning between the two growth modes by addressing the time evolution of the bulk and surface roughness layer thickness. While the pillarlike mode is characterized by a constant growth rate, a slower rate in the initial stage (up to 150-200 nm film thickness), compared to the bulk, is observed for the growth of pyramidlike AZO films. The two modes differ also in terms of surface roughness development: a saturation behavior is observed for film thickness above 150-200 nm in the case of the pyramidlike films, while a slow linear increase with film thickness characterizes the pillarlike mode. By extending the SE analysis of the AZO films to the near infrared region, valuable information about the in grain properties could be extracted: excellent in grain mobility values, i.e., larger than 100 and 50 cm2/V s, are determined for the pyramidlike and pillarlike AZO layers, respectively. The comparison between the outcome of the in situ real time SE studies and the ex situ electrical and chemical characterization highlights the limitations in the electron transport occurring in both types of films and allows one to address routes toward further improvement indress routes toward further improvement in AZO conductivity

104

Enhanced epsilon-poly-L-lysine production from Streptomyces ahygroscopicus by a combination of cell immobilization and in situ adsorption.  

Science.gov (United States)

Epsilon-poly-L-lysine (epsilon-PL), produced by Streptomyces or Kitasatospora strains, is a homo-poly-amino acid of Llysine, which is used as a safe food preservative. The present study investigates the combined use of cell immobilization and in situ adsorption (ISA) to produce epsilon-PL in shaken flasks. Loofah sponge-immobilized Streptomyces ahygroscopicus GIM8 produced slightly more epsilon-PL than those immobilized on synthetic sponge, and sugarcane bagasse. Moreover, loofah sponge supported the maximum biomass. Hence, loofah sponge was chosen for cell immobilization. Meanwhile, the ion-exchange resin D152 was employed for ISA. The loofah sponge-immobilized cells produced 0.54 +/- 0.1 g/l epsilon-PL, which significantly increased to 3.64 +/- 0.32 g/l after combining with ISA through the addition of resin bags. The free cells with ISA using the dispersed resin yielded 2.73 +/- 0.26 g/l of epsilon-PL, an increase from 0.82 +/- 0.08 g/l. These data illustrate that the proposed combination method improved production most significantly compared with either immobilization or ISA only. Moreover, the immobilized cells could be repeatedly used and an epsilon-PL total amount of 8.05 +/- 0.84 g/l was obtained. The proposed combination method offers promising perspectives for epsilon-PL production. PMID:22814495

Liu, Shengrong; Wu, Qingping; Zhang, Jumei; Mo, Shuping; Yang, Xiaojuan; Xiao, Chun

2012-09-01

105

Enhanced and sustained topical ocular delivery of cyclosporine A in thermosensitive hyaluronic acid-based in situ forming microgels.  

Science.gov (United States)

For nearly a decade, thermoresponsive ophthalmic in situ gels have been recognized as an interesting and promising ocular topical delivery vehicle for lipophilic drugs. In this study, a series of thermosensitive copolymers, hyaluronic acid-g-poly(N-isopropylacrylamide) (HA-g-PNIPAAm), was synthesized, by coupling carboxylic end-capped PNIPAAm to aminated hyaluronic acid through amide bond linkages, and was used as a potential carrier for the topical ocular administration of cyclosporine A (CyA). The lower critical solution temperature of HA-g-PNIPAAm59 in aqueous solutions was measured as 32.7°C, which was not significantly affected by the polymer concentration. Moreover, HA-g-PNIPAAm59 microgels showed a high drug loading efficiency (73.92%) and a controlled release profile that are necessary for biomedical application. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) observations showed that HA-g-PNIPAAm microgels were spherical in shape with homogeneous size. Based on the result of the eye irritation test, the HA-g-PNIPAAm microgels formulation was shown to be safe and nonirritant for rabbit eyes. In addition, HA-g-PNIPAAm microgels achieved significantly higher CyA concentration levels in rabbit corneas (1455.8 ng/g of tissue) than both castor oil formulation and commercial CyA eye drops. Therefore, these newly described thermoresponsive HA-g-PNIPAAm microgels demonstrated attractive properties to serve as pharmaceutical delivery vehicles for a variety of ophthalmic applications. PMID:24092975

Wu, Yijun; Yao, Jing; Zhou, Jianping; Dahmani, Fatima Zohra

2013-01-01

106

In situ generation of steam and alkaline surfactant for enhanced oil recovery using an exothermic water reactant (EWR)  

Science.gov (United States)

A method for oil recovery whereby an exothermic water reactant (EWR) encapsulated in a water soluble coating is placed in water and pumped into one or more oil wells in contact with an oil bearing formation. After the water carries the EWR to the bottom of the injection well, the water soluble coating dissolves and the EWR reacts with the water to produce heat, an alkali solution, and hydrogen. The heat from the EWR reaction generates steam, which is forced into the oil bearing formation where it condenses and transfers heat to the oil, elevating its temperature and decreasing the viscosity of the oil. The aqueous alkali solution mixes with the oil in the oil bearing formation and forms a surfactant that reduces the interfacial tension between the oil and water. The hydrogen may be used to react with the oil at these elevated temperatures to form lighter molecules, thus upgrading to a certain extent the oil in situ. As a result, the oil can flow more efficiently and easily through the oil bearing formation towards and into one or more production wells.

Robertson, Eric P

2011-05-24

107

Usage of waste products from thermal recycling of plastics waste in enhanced oil recovery or in-situ coal conversion  

Energy Technology Data Exchange (ETDEWEB)

In this contribution a thermal method for crude oil mobilization and in-situ liquefaction of coal is discussed, which will finally yield more organic material, as which has been put in from plastics waste originally into the process. The conversion product from thermal treatment is pumped down into exhausted crude oil reservoirs, where the hydrogen can degrade the residual high viscous oil to cause it to become more prone to flow so that it can be recovered. Such a process will envision two goals: 1. more organic raw material (as crude oil) will be recovered than is initially put in as waste product. 2. atmospheric pollutants from the conversion plant will be trapped in the reservoir, which simplifies the construction of the plant. An analogous process may be performed with coal seams. Coal seams with their high porosity and large specific surface are believed to be in particular useful to filter atmospheric pollutants. Depending on the type of coal the mobilization of organic material by this process may be in the background. (orig./SR)

Fink, M.; Fink, J.K. [Montanuniversitaet Leoben (Austria)

1998-09-01

108

Structure-based enhanced capacitance: in situ growth of highly ordered polyaniline nanorods on reduced graphene oxide patterns  

Energy Technology Data Exchange (ETDEWEB)

A novel method is described for fabricating an all-solid-state flexible micro-supercapacitor. The microelectrodes of the supercapacitor are prepared by in situ electrodeposition of polyaniline (PANI) nanorods on the surface of reduced graphene oxide (rGO) patterns that are fabricated by micromolding in capillaries. The morphologies of PANI nanorods could be controlled by the concentration of aniline and the growth time in the electrodeposition process. The micro-supercapacitor possesses electrochemical capacitance as high as 970 F g{sup -1} at a discharge current density of 2.5 A g{sup -1}, as well as good stability, retaining 90% of its initial capacitance after 1700 consecutive cycles for the synergistic effect of these new rGO/PANI nanostructures. The results show that the method could represent a route for translating the interesting fundamental properties of rGO and conducting polymers into technologically viable energy devices. Furthermore, this study might further guide the preparation of functional graphene-based materials. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Xue, Mianqi; Li, Fengwang; Zhu, Juan; Song, Hang; Zhang, Meining; Cao, Tingbing [Department of Chemistry, Renmin University of China, Beijing (China)

2012-03-21

109

Enhanced and sustained topical ocular delivery of cyclosporine A in thermosensitive hyaluronic acid-based in situ forming microgels  

Directory of Open Access Journals (Sweden)

Full Text Available Yijun Wu, Jing Yao, Jianping Zhou, Fatima Zohra Dahmani State Key Laboratory of Natural Medicines, China Pharmaceutical University, Tongjiaxiang, Nanjing, People’s Republic of China Abstract: For nearly a decade, thermoresponsive ophthalmic in situ gels have been recognized as an interesting and promising ocular topical delivery vehicle for lipophilic drugs. In this study, a series of thermosensitive copolymers, hyaluronic acid-g-poly(N-isopropylacrylamide (HA-g-PNIPAAm, was synthesized, by coupling carboxylic end-capped PNIPAAm to aminated hyaluronic acid through amide bond linkages, and was used as a potential carrier for the topical ocular administration of cyclosporine A (CyA. The lower critical solution temperature of HA-g-PNIPAAm59 in aqueous solutions was measured as 32.7°C, which was not significantly affected by the polymer concentration. Moreover, HA-g-PNIPAAm59 microgels showed a high drug loading efficiency (73.92% and a controlled release profile that are necessary for biomedical application. Transmission electron microscopy (TEM and atomic force microscopy (AFM observations showed that HA-g-PNIPAAm microgels were spherical in shape with homogeneous size. Based on the result of the eye irritation test, the HA-g-PNIPAAm microgels formulation was shown to be safe and nonirritant for rabbit eyes. In addition, HA-g-PNIPAAm microgels achieved significantly higher CyA concentration levels in rabbit corneas (1455.8 ng/g of tissue than both castor oil formulation and commercial CyA eye drops. Therefore, these newly described thermoresponsive HA-g-PNIPAAm microgels demonstrated attractive properties to serve as pharmaceutical delivery vehicles for a variety of ophthalmic applications. Keywords: thermosensitive microgels, ophthalmic drug delivery, hyaluronic acid, cyclosporine A

Wu Y

2013-09-01

110

An in situ reduction method for preparing silver/poly(vinyl alcohol) nanocomposite as surface-enhanced Raman scattering (SERS)-active substrates  

International Nuclear Information System (INIS)

Novel silver/poly(vinyl alcohol) (PVA) nanocomposite films were obtained by an in situ reduction method, in which the silver nitrate, sodium poly(?-glutamic acid) (PGA) and PVA acted as precursor, stabilizer and polyol reducant, respectively. The surface-enhanced Raman scattering (SERS)-activity of as-prepared nanocomposite films was investigated using benzoic acid (BA) as probed molecule. The results showed that the surface plasmon resonance (SPR) absorption band on silver films was more symmetric with stronger intensity than silver colloidal solution, indicating that the Ag nanoparticle distribution on the film substrate was uniform. The fact was further confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and field-emission scanning electron microscope (FE-SEM) measurements. It was found that PGA-stabilized silver/PVA nanocomposite film revealed the presence of well-dispersed and spherical silver nanoparticles with average diameter of 90 nm, while the particle sizes were enlarged as the PGA concentration increased. The new substrate presented high SERS enhancement and the enhanced factor was estimated to be 106 for the detection of benzoic acid

111

Bifunctional Au@Pt core-shell nanostructures for in situ monitoring of catalytic reactions by surface-enhanced Raman scattering spectroscopy  

Science.gov (United States)

Optical probes of heterogeneous catalytic reactions are of great importance for in situ determination of the catalytic activity and monitoring of the reaction process. Surface-enhanced Raman scattering (SERS) spectroscopy could be used as a sensitive optical probe for this purpose provided that plasmonic metal nanoparticles for Raman enhancement are properly integrated with catalytic metals to form a single entity. Herein we present a facile approach for synthesizing Au@Pt core-shell nanostructures with a controllable surface density of sub-5 nm Pt nanoparticles on the surface of Au nanorods. Systematic investigations on both SERS and catalytic activities of the hybrid nanostructures reveal an optimized surface coverage of Pt. More importantly, we demonstrate that, due to their dual functionalities, the hybrid nanostructures are able to track the Pt-catalysed reaction in real time by measuring the SERS signals of the reactant, intermediate and final products. This SERS-based synergy technique provides a novel approach for quantitatively studying catalytic chemical reaction processes and is suitable for many applications such as reduction and oxidation reactions in fuel cells and catalytic water splitting.Optical probes of heterogeneous catalytic reactions are of great importance for in situ determination of the catalytic activity and monitoring of the reaction process. Surface-enhanced Raman scattering (SERS) spectroscopy could be used as a sensitive optical probe for this purpose provided that plasmonic metal nanoparticles for Raman enhancement are properly integrated with catalytic metals to form a single entity. Herein we present a facile approach for synthesizing Au@Pt core-shell nanostructures with a controllable surface density of sub-5 nm Pt nanoparticles on the surface of Au nanorods. Systematic investigations on both SERS and catalytic activities of the hybrid nanostructures reveal an optimized surface coverage of Pt. More importantly, we demonstrate that, due to their dual functionalities, the hybrid nanostructures are able to track the Pt-catalysed reaction in real time by measuring the SERS signals of the reactant, intermediate and final products. This SERS-based synergy technique provides a novel approach for quantitatively studying catalytic chemical reaction processes and is suitable for many applications such as reduction and oxidation reactions in fuel cells and catalytic water splitting. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr00770k

Bao, Zhi Yong; Lei, Dang Yuan; Jiang, Ruibin; Liu, Xin; Dai, Jiyan; Wang, Jianfang; Chan, Helen L. W.; Tsang, Yuen Hong

2014-07-01

112

In situ evaluation of orthodontic elastomeric chains  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A hipótese testada foi que a exposição dos elásticos em cadeia ao meio bucal altera sua força de tensão. Portanto, o objetivo deste estudo foi avaliar o comportamento, in situ, de diferentes cadeias elastoméricas quando tensionadas durante 3 semanas. Três tipos de elásticos em cadeia Plastic Chain ( [...] PC), Memory Chain (MC) e Super Slick Chain (SSC) foram inseridos aleatoriamente em 3 dos quadrantes de 13 pacientes com distância fixa de 16 mm e força inicial de 180 g. Foi realizado ensaio de tração em uma máquina de ensaio universal EMIC nos seguintes intervalos: inicial, 1 h, 24 h, 1 semana, 2 semanas e 3 semanas. O teste ANOVA a dois critérios foi aplicado para verificar a influência do material e do tempo na degradação da força. Subsequentemente, foi utilizado o teste ANOVA a um critério e pós-teste de Tukey para identificar diferenças estatísticas (p Abstract in english The hypothesis tested in this study was that intraoral exposure of elastomeric chains alters their tensile strength. For such purpose, it was evaluated the in situ behavior of different elastomeric chains stretched for 3 weeks. Three kinds of elastomeric chains, Plastic chain (PC), Memory chain (MC) [...] and Super slick chain (SSC), were randomly placed in 3 quadrants of 13 patient in a fixed distance of 16 mm and mean initial force of 180 g. Tensile testing was performed in an universal testing machine at different intervals: initial, 1 h, 24 h, 1 week, 2 weeks and 3 weeks. A two-way ANOVA test was performed to identify the influence of both material and time on the force decrease. A subsequent one-way ANOVAtest with the Tukey's post hoc test was used to identify statistically significant intragroup and intergroup remaining force (g and %) differences at 5% significance level. The effect of both the material and the time factors were significant. All groups showed significant force decrease after the 1-h period (23% for PC and 14% for MC and SSC). At the end of the 3-week period, the remaining force was 57% (96 g), 67% (129 g) and 71% (125 g) for PC, MC and SSC, respectively. In conclusion, intraoral exposure of elastomeric chains altered their tensile strength. In general, the greater force decrease occurred within the first hour. The remaining force of the enhanced chains measured at each time interval was greater than the conventional one (PC). After 3 weeks, only the enhanced chains maintained the force applied over 100 g.

Carolina, Baratieri; Cláudia Trindade, Mattos; Matheus, Alves Jr; Thiago Chon Leon, Lau; Lincoln Issamu, Nojima; Margareth Maria Gomes de, Souza; Monica Tirre, Araujo; Matilde da Cunha Gonçalves, Nojima.

113

Ultrasonic enhancement of leaching and in situ derivatization of haloacetic acids in vegetable foods prior to gas chromatography-electron capture detection.  

Science.gov (United States)

A continuous ultrasound-assisted approach to enhance the extraction of nine haloacetic acids (HAAs) from vegetables with in situ derivatization to methyl esters for their gas chromatography (GC) analysis is presented. The optimization of simultaneous extraction (using acidic methanol as extractant) and derivatization enabled the completion of both steps in 15 min. Ultrasound assistance has proved to enhance both linked steps, which results in a considerable shortening of the overall analysis time (i.e. 552.1 and 552.2 EPA methods for analysis of these compounds in drinking water require 1 and 2 h, respectively, only for derivatization). After sample preparation, the esterified HAAs were isolated by liquid-liquid extraction with n-hexane and analysed by GC-electron capture detection. The proposed method is an interesting alternative to present methods for the determination of HAAs in vegetable foods. This is an area unjustifiably forgotten by reference laboratory organisms as proved by the absence of official methods for analysis of the target compounds in these samples. The proposed method can be applied to the analysis of HAAs in any solid sample after optimization of the main variables involved in the extraction-derivatization step. PMID:18586256

Alvarez Sánchez, B; Priego Capote, F; Luque de Castro, M D

2008-08-01

114

Enhanced photoelectrochemical performance of WO{sub 3}/Ti photoanode due to in situ formation of a thin interfacial composite layer  

Energy Technology Data Exchange (ETDEWEB)

Nanostructured WO{sub 3} thin films were prepared on titanium sheet substrates using a doctor blade technique. X-ray diffraction, Raman and field emission scanning electron microscopy studies revealed that the synthesized WO{sub 3} films are having monoclinic crystal structure, porous, polycrystalline with average grain size of ?50 nm. The photoelectrochemical responses of WO{sub 3} films prepared on treated Ti sheets were recorded in 0.5 M H{sub 2}SO{sub 4} electrolyte under simulated 100 mW/cm{sup 2} illumination. WO{sub 3} film prepared on polished Ti sheet showed considerable enhancement in photocurrent as compared to WO{sub 3} films made on unpolished and pre-oxidized Ti sheets. These results suggest that in situ formation of a thin WO{sub x}–TiO{sub y} interfacial composite layer and improved adhesion of WO{sub 3} nanoparticles owing to increased reactive sites on polished Ti substrate play a significant role in enhancing the photoresponse. Such photoanodes are potential candidates in photoelectrochemical water splitting system for hydrogen generation.

Lee, Won Jae, E-mail: wjlee@keri.re.kr [Battery Research Center, Korea Electrotechnology Research Institute (KERI), Changwon 641-120 (Korea, Republic of); Shinde, Pravin S.; Go, Geun Ho; Doh, Chil Hoon [Battery Research Center, Korea Electrotechnology Research Institute (KERI), Changwon 641-120 (Korea, Republic of)

2013-04-01

115

Bifunctional Au@Pt core-shell nanostructures for in situ monitoring of catalytic reactions by surface-enhanced Raman scattering spectroscopy.  

Science.gov (United States)

Optical probes of heterogeneous catalytic reactions are of great importance for in situ determination of the catalytic activity and monitoring of the reaction process. Surface-enhanced Raman scattering (SERS) spectroscopy could be used as a sensitive optical probe for this purpose provided that plasmonic metal nanoparticles for Raman enhancement are properly integrated with catalytic metals to form a single entity. Herein we present a facile approach for synthesizing Au@Pt core-shell nanostructures with a controllable surface density of sub-5 nm Pt nanoparticles on the surface of Au nanorods. Systematic investigations on both SERS and catalytic activities of the hybrid nanostructures reveal an optimized surface coverage of Pt. More importantly, we demonstrate that, due to their dual functionalities, the hybrid nanostructures are able to track the Pt-catalysed reaction in real time by measuring the SERS signals of the reactant, intermediate and final products. This SERS-based synergy technique provides a novel approach for quantitatively studying catalytic chemical reaction processes and is suitable for many applications such as reduction and oxidation reactions in fuel cells and catalytic water splitting. PMID:24976250

Bao, Zhi Yong; Lei, Dang Yuan; Jiang, Ruibin; Liu, Xin; Dai, Jiyan; Wang, Jianfang; Chan, Helen L W; Tsang, Yuen Hong

2014-08-01

116

Predictive value of the surface-enhanced resonance Raman scattering-based MTT assay: a rapid and ultrasensitive method for cell viability in situ.  

Science.gov (United States)

SERRS (surface-enhanced resonance Raman scattering) has been used to develop and optimize a novel and quantitative MTT assay for living cell viability. This highly sensitive method derives from two factors for formazan signal enhancing: the addition of Au nanoparticles and the resonance effect by 632.8 nm of excitation. The results show that the background elements, such as excessive MTT residues, serum, and the drug, did not interfere with the detection of formazan. Moreover, the detection limit of formazan is as low as 1 ng/mL. With the use of this method to quantify metabolically viable cells, dose-response curves of treated and untreated cells with the drug were constructed on the human lung cancer cell A549. The results also show that the Raman signal generated is dependent on the degree of activation of the cells. In comparison to the traditional method, the main advantages of this method are its rapidity (30 min), high-selectivity, high-precision, and cost-effectiveness (0.1 mg/mL MTT) without time-consuming steps and any modifying or labeling procedure. This work reports on an improved research tool that may help researchers apply this method for in situ cell assays. PMID:23815261

Mao, Zhu; Liu, Zhuo; Chen, Lei; Yang, Jin; Zhao, Bing; Jung, Young Mee; Wang, Xu; Zhao, Chun

2013-08-01

117

In situ Silver Spot Preparation and on-Plate Surface-Enhanced Raman Scattering Detection in Thin Layer Chromatography Separation  

Science.gov (United States)

An improved approach for surface-enhanced Raman scattering (SERS) detection of mixture constituents after thin layer chromatography (TLC) separation is presented. A SERS active silver substrate was prepared under open air conditions, directly on the thin silica film by photo-reduction of silver nitrate, allowing the detection of binary mixtures of cresyl violet, bixine, crystal violet, and Cu(II) complex of 4-(2-pyridylazo)resorcinol. The recorded SERS spectrum provides a unique spectral fingerprint for each molecule; therefore the use of analyte standards is avoided, thus rendering the presented procedure advantageous compared to the conventional detection methodology in TLC.

Herman, K.; Mircescu, N. E.; Szabo, L.; Leopold, L. F.; Chi?, V.; Leopold, N.

2013-05-01

118

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

Science.gov (United States)

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

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

2014-11-26

119

In situ monitoring of thermal crystallization of ultrathin tris(8-hydroxyquinoline) aluminum films using surface-enhanced Raman scattering.  

Science.gov (United States)

Thermal crystallization of 3, 10, and 60 nm-thick tris(8-hydroxyquinoline)aluminum (Alq3) films is studied using surface-enhanced Raman scattering with a constant heating rate. An abrupt higher frequency shift of the quinoline-stretching mode is found to be an indication of a phase transition of Alq3 molecules from amorphous to crystalline. While the 60 nm-thick film shows the same crystallization temperature as a bulk sample, the thinner films were found to have a lower crystallization temperature and slower rate of crystallization. Non-isothermal kinetics analysis is performed to quantify kinetic properties such as the Avrami exponent constants and crystallization rates of ultrathin Alq3 films. PMID:24405952

Muraki, Naoki

2014-01-01

120

Trans-resveratrol self-nano-emulsifying drug delivery system (SNEDDS) with enhanced bioavailability potential: optimization, pharmacokinetics and in situ single pass intestinal perfusion (SPIP) studies.  

Science.gov (United States)

Abstract Trans-resveratrol (t-RVT) is a potent antioxidant. By virtue of extensive pre-systemic metabolism and existence of enterohepatic recirculation, t-RVT bioavailability is almost zero. The current study aimed to develop self-nanoemulsifying drug delivery systems (SNEDDS) using long-chain triglycerides (LCTs) of t-RVT in an attempt to circumvent such obstacles. Equilibrium solubility studies indicated the choice of Lauroglycol FCC as lipid, and of Labrasol and Transcutol P as surfactants, for formulating the SNEDDS. Ternary phase diagrams were constructed to select the areas of nanoemulsions, and the amounts of lipid (X1) and surfactant (X2) as the critical factor variables. The SNEDDS were optimized using 3(2) central composite design (CCD) and the optimized formulation (OPT) located using overlay plot. The nanometer size range and high negative values of zeta potential depicted non-coalescent nature of the SNEDDS. Optimized formulation indicated marked improvement in drug release profile vis-à-vis pure drug. Cloud point determination and accelerated stability studies ascertained the stability of OPT. Augmentation in the values of Ka (3.29-fold) and AUC (4.31-fold) indicated significant enhancement in the rate and extent of bioavailability by the OPT compared with pure drug. In situ perfusion (SPIP) studies in Wistar rats construed remarkable enhancement in the absorptivity and permeability parameters of SNEDDS vis-à-vis the pure drug. Successful establishment of level A of in vitro/in vivo correlation substantiated the judicious choice of the in vitro dissolution milieu for simulating the in vivo conditions. The present study, therefore, reports the successful development of SNEDDS with distinctly enhanced bioavailability of t-RVT. PMID:24512464

Singh, Gurinder; Pai, Roopa S

2014-02-11

121

In situ vitrification  

International Nuclear Information System (INIS)

As management of hazardous materials gains increased attention in the United States, new and more effective technologies are being sought to immobilize and/or destroy the wastes, either in situ for previously disposed wastes or at the waste generation site. The new Hazardous and Solid Waste Amendments (HSWA) 1984 and the Superfund Amendments and Reauthorization Act (SARA) 1986, combined with proposed rule making by the U.S. Environmental Protection Agency (EPA) is making landfill disposal very costly and is moving in a direction that will severely limit future land disposal. Further, the extended liability associated with future environmental impairment provides a significant corporate incentive to dispose and delist wastes within the plant or waste site boundary. The authors discuss a remedial action process for contaminated soils that is potentially significant in its application to these concerns. Although the process was initially developed to provide enhanced isolation to previously disposed radioactive wastes, recent tests have shown that many hazardous chemical wastes are also destroyed or immobilized as a result of the treatment. The process, in situ vitrification (ISV), was originally developed for the U.S. Department of Energy (DOE) and is more recently being adapted for selected commercial clients for hazardous wastes

122

Remarkable biocompatibility enhancement of porous NiTi alloys by a new surface modification approach: in-situ nitriding and in vitro and in vivo evaluation.  

Science.gov (United States)

An in-situ nitriding method has been developed to modify the outer surface and the pore walls of both open and closed pores of porous NiTi shape memory alloys (SMAs) as part of their sintering process. XRD and XPS examinations revealed that the modified layer is mainly TiN. The biocompatibility of the in-situ nitrided sample has been characterized by its corrosion resistance, cell adherence, and implant surgery. The in-situ nitrided porous NiTi SMAs exhibit much better corrosion resistance, cell adherence, and bone tissue induced capability than the porous NiTi alloys without surface modification. Furthermore, the released Ni ion content in the blood of rabbit is reduced greatly by the in-situ nitriding. The excellent biocompatibility of in-situ nitrided sample is attributed to the formation of the TiN layer on all the pore walls including both open and closed pores. PMID:21936044

Li, H; Yuan, B; Gao, Y; Chung, C Y; Zhu, M

2011-12-15

123

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

International Nuclear Information System (INIS)

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

124

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2008-06-30

125

High sensitivity in situ monitoring of NO3 in an atmospheric simulation chamber using incoherent broadband cavity-enhanced absorption spectroscopy.  

Science.gov (United States)

We describe the application of incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS) for the in situ detection of atmospheric trace gases and radicals (NO3, NO2, O3, H2O) in an atmospheric simulation chamber under realistic atmospheric conditions. The length of the optical cavity across the reaction chamber is 4.5 m, which is significantly longer than in previous studies that use high finesse optical cavities to achieve high absorption sensitivity. Using a straightforward spectrometer configuration, we show that detection limits corresponding to typical atmospheric concentrations can be achieved with a measurement time of seconds to a few minutes. In particular, with only moderate reflectivity mirrors, we report a measured sensitivity of 4 pptv to NO3 in a 1 min acquisition time. The high spatial and temporal resolution of the IBBCEAS method and its pptv sensitivity to NO3 makes it useful in laboratory studies of atmospheric processes as well as having obvious potential for field measurements. PMID:17144307

Venables, Dean S; Gherman, Titus; Orphal, Johannes; Wenger, John C; Ruth, Albert A

2006-11-01

126

An innovative bioelectrochemical-anaerobic digestion-coupled system for in-situ ammonia recovery and biogas enhancement: process performance and microbial ecology  

DEFF Research Database (Denmark)

Ammonia (NH4+/NH3) inhibition during anaerobic digestion process is one of the most frequent problems existing in biogas plants, resulting in unstable process and reduced biogas production. In this study, we developed a novel hybrid system, consisted of a submersed microbial resource recovery cell (SMRC) and a continuous stirred tank reactor (CSTR), to prevent ammonia toxicity during anaerobic digestion by in-situ ammonia recovery and electricity production. In batch experiment, the ammonia concentration in the CSTR decreased from 6 to 0.7 g-N/L with an average recovery rate of 0.18 g-N/L(CSTR)/d. Meanwhile, a maximum power density of 0.71±0.5 W/m2 was produced (10 ?). Both current driven NH4+ migration and free NH3 diffusion were identified as the mechanisms responsible for the ammonia transportation. With an increase in initial ammonia concentration and a decrease in external resistance, the SMRC performance was enhanced. In addition, the coexistence of other cations in CSTR or cathode had no negative effect on the ammonia transportation. In continuous reactor operation, 112% extra biogas production was achieved due to ammonia recovery. High-throughput molecular sequencing analysis showed an impact of ammonia recovery on the microbial community composition in the integrated system. Results clearly indicate the great potential of the SMRC-CSTR-coupled system for efficient and cost-effective ammonia recovery, energy production and treatment of ammonia-rich residues.

Zhang, Yifeng; Angelidaki, Irini

127

Characterizing early contrast uptake of ductal carcinoma in situ with high temporal resolution dynamic contrast-enhanced MRI of the breast: a pilot study  

International Nuclear Information System (INIS)

Improvements in the reliable diagnosis of preinvasive ductal carcinoma in situ (DCIS) by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) are needed. In this study, we present a new characterization of early contrast kinetics of DCIS using high temporal resolution (HiT) DCE-MRI and compare it with other breast lesions and normal parenchyma. Forty patients with mammographic calcifications suspicious for DCIS were selected for HiT imaging using T1-weighted DCE-MRI with ?7 s temporal resolution for 90 s post-contrast injection. Pixel-based and whole-lesion kinetic curves were fit to an empirical mathematical model (EMM) and several secondary kinetic parameters derived. Using the EMM parameterized and fitted concentration time curve for subsequent analysis allowed for calculation of kinetic parameters that were less susceptible to fluctuations due to noise. The parameters' initial area under the curve (iAUC) and contrast concentration at 1 min (C1min) provided the highest diagnostic accuracy in the task of distinguishing pathologically proven DCIS from normal tissue. There was a trend for DCIS lesions with solid architectural pattern to exhibit a negative slope at 1 min (i.e. increased washout rate) compared to those with a cribriform pattern (p < 0.04). This pilot study demonstrates the feasibility of quantitative analysis of early contrast kinetics at high temporal resolution and points to the potential for such an analysis to impro potential for such an analysis to improve the characterization of DCIS. (note)

128

Long-term population dynamics and in situ physiology in activated sludge systems with enhanced biological phosphorus removal operated with and without nitrogen removal  

DEFF Research Database (Denmark)

Quantitative fluorescence in situ hybridization (FISH) and the combination of FISH with microautoradiography (MAR) were used in order to study the long-term population dynamics (2.5 years) and the in situ physiology in two parallel activated sludge pilot systems with enhanced biological phosphorus removal (EBPR). The two systems received the same influent wastewater, but were differently operated (with and without nitrogen removal, respectively). Both systems showed a significant P removal that increased when different substrates (phosphorus (P), acetate and glucose, respectively) were added to the influent wastewater. Rhodocyclus-related bacteria were present in both systems in significant numbers (ranging from 4 to 28%) throughout the whole period. This supports the hypothesis that these bacteria occur in significant numbers in different types of well-operating EBPR activated sludge processes. However, we observed a lower correlation (0.9). The Actinobacteria were the only additional group of bacteria whichshowed a similar degree of correlation to the P content in activated sludge as the Rhodocyclus-related bacteria - but only for the system without nitrogen removal. Significant amounts (less than or equal to12%) of glycogen-accumulating bacteria (GAOs) were detected in the system with nitrogen removal (but not in the other system), but had no, in contrast to previous observations, apparent negative effect on the overall EBPR performance. FISH-MAR indicated that a significant part of the Betaproteobacteria (part of them identified as Rhodocyclus-related bacteria) as well as the Actinobacteria were able to take up P-33(i), [H-3]-acetate and [H-3]-glucose under anaerobic-aerobic conditions. The contribution of anoxic P-33(i) uptake under alternating anaerobic-anoxic conditions was significantly lower. Interestingly, not all Rhodocyclus-related bacteria showed uptake of these three radioactive substrates. This may be due to differences in metabolic state, physiological potential or genotype, not detectable by thepresent probe set for Rhodocyclus-related bacteria. Comparison of the P-33(i), [H-3]-acetate and [H-3]-glucose uptake by activated sludge after different fixation and incubation procedures showed that a part of the observed P-33(i), uptake may have been caused by a combination of a biological and chemical or biologically induced chemical P adsorption.

Lee, N.; Nielsen, P.H.

2003-01-01

129

In-situ preparation of N-TiO2/graphene nanocomposite and its enhanced photocatalytic hydrogen production by H2S splitting under solar light.  

Science.gov (United States)

Highly monodispersed nitrogen doped TiO2 nanoparticles were successfully deposited on graphene (N-TiO2/Gr) by a facile in-situ wet chemical method for the first time. N-TiO2/Gr has been further used for photocatalytic hydrogen production using a naturally occurring abundant source of energy i.e. solar light. The N-TiO2/Gr nanocomposite composition was optimized by varying the concentrations of dopant nitrogen and graphene (using various concentrations of graphene) for utmost hydrogen production. The structural, optical and morphological aspects of nanocomposites were studied using XRD, UV-DRS, Raman, XPS, FESEM, and TEM. The structural study of the nanocomposite shows existence of anatase N-TiO2. Further, the details of the components present in the composition were confirmed with Raman and XPS. The morphological study shows that very tiny, 7-10 nm sized, N-TiO2 nanoparticles are deposited on the graphene sheet. The optical study reveals a drastic change in absorption edge and consequent total absorption due to nitrogen doping and presence of graphene. Considering the extended absorption edge to the visible region, these nanocomposites were further used as a photocatalyst to transform hazardous H2S waste into eco-friendly hydrogen using solar light. The N-TiO2/Gr nanocomposite with 2% graphene exhibits enhanced photocatalytic stable hydrogen production i.e. ?5941 ?mol h(-1) under solar light irradiation using just 0.2 gm nanocomposite, which is much higher as compared to P25, undoped TiO2 and TiO2/Gr nanocomposite. The enhancement in the photocatalytic activity is attributed to 'N' doping as well as high specific surface area and charge carrier ability of graphene. The recycling of the photocatalyst shows a good stability of the nanocomposites. This work may provide new insights to design other semiconductor deposited graphene novel nanocomposites as a visible light active photocatalyst. PMID:25697910

Bhirud, Ashwini P; Sathaye, Shivaram D; Waichal, Rupali P; Ambekar, Jalindar D; Park, Chan-J; Kale, Bharat B

2015-03-01

130

Enhanced lithium storage in a VO2(B)-multiwall carbon nanotube microsheet composite prepared via an in situ hydrothermal process  

International Nuclear Information System (INIS)

A novel VO2(B)-multiwall carbon nanotube (MWCNT) composite with a sheet-like morphology was synthesized by a simple in situ hydrothermal process. The morphology and structural properties of the samples were investigated by X-ray diffraction (XRD), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). FE-SEM observations demonstrated that the nanosheets are frequently grown together in the form of bundles composed of numerous nanosheets, each with a smooth surface and a typical length of 300-500 nm, width of 50-150 nm, and thickness of 10-50 nm. Electrochemical measurements were carried out using different discharge cut-off voltages. Electrochemical tests show that the VO2(B)-MWCNT composite cathode features long-term cycling stability and high discharge capacity (177 mAh g-1) in the voltage range of 2.0-3.25 V at 1 C with a capacity retention of 92% after 100 cycles. The electrochemical impedance spectra (EIS) indicate that the VO2(B)-MWCNT composite electrode has very low charge-transfer resistance compared with pure VO2(B), indicating the enhanced ionic conductivity of the VO2(B)-MWCNT composite. The enhanced cycling stability is attributed to the fact that the VO2(B)-MWCNT composite can prevent the aggregation of active materials, accommodate the large volume variation, and maintain good electronic contact. We stnd maintain good electronic contact. We strongly believe that the VO2(B)-MWCNT composite can be considered as a potential cathode material for lithium-ion batteries.

131

Three two-week enhancement institutes: Design and implementation of the technology and telecomputing component  

Science.gov (United States)

The Teacher Enhancement Institute (TEI), under the direction of the Center Education Programs Officer offered three two-week workshops to 58 elementary and middle school teachers in science, math, and technology using the Problem Based Learning Model. The 1995 program was designed with input from evaluations and recommendations from previous TEI participants and faculty. The TEI focused on Aviation and Aeronautics as the unifying theme. Four specific objectives were developed. After completing the requirements for the TEI, the participants should be able to: (1) Increase their content knowledge, particularly in aeronautics, science, math, and technology; (2) Design and implement lessons that use scientific inquiry through Problem Based Learning; (3) Demonstrate knowledge of instructional technologies, their uses, and applications to curricula; and (4) Disseminate to their school communities the information acquired through the TEI. Thirty percent of the program was devoted to the effective use of computer technology. SpaceLink, the NASA telecomputing service for educators, was the primary tool used in the technology component of the institute. The training focused on the use of SpaceLink and its many educational services, and Internet tools because of its universal, nongraphical link to any computer plafform the participant may use at his or her school or home. All participants were given Educator Accounts to facilitate the use of E-mail, and access to the Internet and the World Wide Web using their SpaceLink accounts. Classroom demonstrations used videotaped guides and handouts to support concepts presented followed by intensive hands-on activities. Each participant was assigned to an individual Power Mac networked workstation and introduced to the state of the art, graphical, Word Wide Web with the Netscape browser. The methodology proved very effective in reaching the program's goals for technology integration by having the participants learn to use the computer as a tool for communication and research rather than teaching the use of any particular software application alone. However, because of the skill level of the majority of the participants, more hands-on computer time is recommended for future Teacher Enhancement Institutes.

Hale, L. Vincent

1995-01-01

132

In situ assembly of well-dispersed Au nanoparticles on TiO2/ZnO nanofibers: A three-way synergistic heterostructure with enhanced photocatalytic activity  

International Nuclear Information System (INIS)

Graphical abstract: We describe a route to synthesize TiO2/ZnO/Au three-way synergistic heterostructure nanofibers with high efficiency photocatalysts. Highlights: ? Synthesis of tri-component TiO2/ZnO/Au nanofibers. ? TiO2/ZnO/Au nanofibers showed excellent photocatalytic activity. ? Easy photocatalyst separation and reuse. - Abstract: The TiO2/ZnO nanofibers embedded by Au nanoparticles (TiO2/ZnO/Au NFs) were fabricated by combining the electrospinning technique (for TiO2/ZnO nanofibers) and an in situ reduction approach (for Au nanoparticles). X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electronmicroscopy, X-ray photoelectron spectroscopy, UV–vis diffuse reflectance spectroscopy and photoluminescence spectroscopy, were used to characterize the as-synthesized nanofibers. The results showed that small Au nanoparticles (Au NPs) were well dispersed on the TiO2/ZnO nanofibers (TiO2/ZnO NFs). And, the TiO2/ZnO/Au nanofibers showed high charge separation efficiency under ultraviolet excitation, as evidenced by photoluminescence spectra. The photocatalytic studies revealed that the TiO2/ZnO/Au NFs exhibited enhanced photocatalytic efficiency of photodegradation of Methyl orange (MO) and 4-nitrophenol (4-NP) compared with the pure TiO2 nanofibers, ZnO nanofibers and TiO2/ZnO NFs uners and TiO2/ZnO NFs under ultraviolet excitation, which might be attributed to the high separation efficiency of photogenerated electron–hole pairs based on the photosynergistic effect among the three components of TiO2, ZnO and Au. And, the TiO2/ZnO/Au NFs could be easily separated and recycled due to their one-dimensional nanostructural property.

133

In situ Remediation Technologies  

OpenAIRE

A summary of two decades of developments of In Situ remediation is presented in this chapter. The basic principles of In Situ technology application are addressed, such as equilibrium relations between contaminant phases, factors controlling biological and geochemical processes, contaminant characteristics affecting reductive and oxidative conversion parameters and chemical and biological availability. A wide range of In Situ technologies are discussed within the framework of Risk Management....

Grotenhuis, J. T. C.; Rijnaarts, H. H. M.

2011-01-01

134

In-situ preparation of N-TiO2/graphene nanocomposite and its enhanced photocatalytic hydrogen production by H2S splitting under solar light  

Science.gov (United States)

Highly monodispersed nitrogen doped TiO2 nanoparticles were successfully deposited on graphene (N-TiO2/Gr) by a facile in-situ wet chemical method for the first time. N-TiO2/Gr has been further used for photocatalytic hydrogen production using a naturally occurring abundant source of energy i.e. solar light. The N-TiO2/Gr nanocomposite composition was optimized by varying the concentrations of dopant nitrogen and graphene (using various concentrations of graphene) for utmost hydrogen production. The structural, optical and morphological aspects of nanocomposites were studied using XRD, UV-DRS, Raman, XPS, FESEM, and TEM. The structural study of the nanocomposite shows existence of anatase N-TiO2. Further, the details of the components present in the composition were confirmed with Raman and XPS. The morphological study shows that very tiny, 7-10 nm sized, N-TiO2 nanoparticles are deposited on the graphene sheet. The optical study reveals a drastic change in absorption edge and consequent total absorption due to nitrogen doping and presence of graphene. Considering the extended absorption edge to the visible region, these nanocomposites were further used as a photocatalyst to transform hazardous H2S waste into eco-friendly hydrogen using solar light. The N-TiO2/Gr nanocomposite with 2% graphene exhibits enhanced photocatalytic stable hydrogen production i.e. ~5941 ?mol h-1 under solar light irradiation using just 0.2 gm nanocomposite, which is much higher as compared to P25, undoped TiO2 and TiO2/Gr nanocomposite. The enhancement in the photocatalytic activity is attributed to `N' doping as well as high specific surface area and charge carrier ability of graphene. The recycling of the photocatalyst shows a good stability of the nanocomposites. This work may provide new insights to design other semiconductor deposited graphene novel nanocomposites as a visible light active photocatalyst.Highly monodispersed nitrogen doped TiO2 nanoparticles were successfully deposited on graphene (N-TiO2/Gr) by a facile in-situ wet chemical method for the first time. N-TiO2/Gr has been further used for photocatalytic hydrogen production using a naturally occurring abundant source of energy i.e. solar light. The N-TiO2/Gr nanocomposite composition was optimized by varying the concentrations of dopant nitrogen and graphene (using various concentrations of graphene) for utmost hydrogen production. The structural, optical and morphological aspects of nanocomposites were studied using XRD, UV-DRS, Raman, XPS, FESEM, and TEM. The structural study of the nanocomposite shows existence of anatase N-TiO2. Further, the details of the components present in the composition were confirmed with Raman and XPS. The morphological study shows that very tiny, 7-10 nm sized, N-TiO2 nanoparticles are deposited on the graphene sheet. The optical study reveals a drastic change in absorption edge and consequent total absorption due to nitrogen doping and presence of graphene. Considering the extended absorption edge to the visible region, these nanocomposites were further used as a photocatalyst to transform hazardous H2S waste into eco-friendly hydrogen using solar light. The N-TiO2/Gr nanocomposite with 2% graphene exhibits enhanced photocatalytic stable hydrogen production i.e. ~5941 ?mol h-1 under solar light irradiation using just 0.2 gm nanocomposite, which is much higher as compared to P25, undoped TiO2 and TiO2/Gr nanocomposite. The enhancement in the photocatalytic activity is attributed to `N' doping as well as high specific surface area and charge carrier ability of graphene. The recycling of the photocatalyst shows a good stability of the nanocomposites. This work may provide new insights to design other semiconductor deposited graphene novel nanocomposites as a visible light active photocatalyst. Electronic supplementary information (ESI) available: Raman of GO, XPS of GO, FESEM of GO, undoped TiO2 and N-TiO2, graph of % graphene vs. H2 production, hydrogen evolution of recycled T6 sample, XRD of sample (T6) after three cyles of photocatalytic study

Bhirud, Ashwini P.; Sathaye, Shivaram D.; Waichal, Rupali P.; Ambekar, Jalindar D.; Park, Chan-J.; Kale, Bharat B.

2015-03-01

135

Analysis of the fine-scale population structure of "Candidatus accumulibacter phosphatis" in enhanced biological phosphorus removal sludge, using fluorescence in situ hybridization and flow cytometric sorting.  

Science.gov (United States)

To investigate the fine-scale diversity of the polyphosphate-accumulating organisms (PAO) "Candidatus Accumulibacter phosphatis" (henceforth referred to as "Ca. Accumulibacter"), two laboratory-scale sequencing batch reactors (SBRs) for enhanced biological phosphorus removal (EBPR) were operated with sodium acetate as the sole carbon source. During SBR operations, activated sludge always contained morphologically different "Ca. Accumulibacter" strains showing typical EBPR performances, as confirmed by the combined technique of fluorescence in situ hybridization (FISH) and microautoradiography (MAR). Fragments of "Ca. Accumulibacter" 16S rRNA genes were retrieved from the sludge. Phylogenetic analyses together with sequences from the GenBank database showed that "Ca. Accumulibacter" 16S rRNA genes of the EBPR sludge were clearly differentiated into four "Ca. Accumulibacter" clades, Acc-SG1, Acc-SG2, Acc-SG3, and Acc-SG4. The specific FISH probes Acc444, Acc184, Acc72, and Acc119 targeting these clades and some helpers and competitors were designed by using the ARB program. Microbial characterization by FISH analysis using specific FISH probes also clearly indicated the presence of different "Ca. Accumulibacter" cell morphotypes. Especially, members of Acc-SG3, targeted by probe Acc72, were coccobacillus-shaped cells with a size of approximately 2 to 3 mum, while members of Acc-SG1, Acc-SG2, and Acc-SG4, targeted by Acc444, Acc184, and Acc119, respectively, were coccus-shaped cells approximately 1 mum in size. Subsequently, cells targeted by each FISH probe were sorted by use of a flow cytometer, and their polyphosphate kinase 1 (ppk1) gene homologs were amplified by using a ppk1-specific PCR primer set for "Ca. Accumulibacter." The phylogenetic tree based on sequences of the ppk1 gene homologs was basically congruent with that of the 16S rRNA genes, but members of Acc-SG3 with a distinct morphology comprised two different ppk1 genes. These results suggest that "Ca. Accumulibacter" strains may be diverse physiologically and ecologically and represent distinct populations with genetically determined adaptations in EBPR systems. PMID:20418432

Kim, Jeong Myeong; Lee, Hyo Jung; Kim, Sun Young; Song, Jae Jun; Park, Woojun; Jeon, Che Ok

2010-06-01

136

Enhancement of electrical characteristics and reliability in crystallized ZrO2 gate dielectrics treated with in-situ atomic layer doping of nitrogen  

International Nuclear Information System (INIS)

The crystallized ZrO2 high-K gate dielectrics treated with in-situ atomic layer doping of nitrogen using remote N2 and NH3 plasma were investigated, to suppress the capacitance equivalent thickness (CET), leakage current density (Jg), and interfacial state density (Dit). The stress-induced leakage current (SILC) was reduced significantly as well. The tetragonal/cubic phase of ZrO2 was formed by post metallization annealing at a low temperature of 450 °C to offer a high dielectric constant of the gate oxide. The in-situ atomic layer doping of nitrogen using the remote NH3 plasma contributes to the deactivation of the oxygen vacancies and the well passivation of Dit. Accordingly, a suppressed Jg of 4.79 × 10?5 A cm?2 and Dit of 3.96 × 1011 cm?2 eV?1 were realized in the crystallized ZrO2 gate oxide with a low CET of 1.35 nm. The gate dielectrics were also optically examined by the photoluminescence from the high-K/Si interface, indicating that the Dit is highly correlated with the hydrogen passivation originating from the remote NH3 plasma. The results indicate that in-situ atomic layer doping of nitrogen is an applicable and effective technique to improve the electrical properties of crystallized gate dielectrics in the advanced metal-oxide-semiconductor devices.

137

Two weeks of metformin treatment induces AMPK dependent enhancement of insulin-stimulated glucose uptake in mouse soleus muscle  

DEFF Research Database (Denmark)

Background: Metformin-induced activation of AMPK has been associated with enhanced glucose uptake in skeletal muscle but so far no direct causality has been examined. We hypothesized that an effect of in vivo metformin treatment on glucose uptake in mouse skeletal muscles is dependent upon AMPK signaling. Methods: Oral doses of metformin or saline treatment were given muscle-specific kinase ?2 dead AMPK mice (KD) and wild type (WT) littermates either once or chronically for 2 weeks. Soleus and Extensor Digitorum Longus (EDL) muscles were used for measurements of glucose transport and Western blot analyzes. Results: Chronic treatment with metformin enhanced insulin-stimulated glucose uptake in soleus muscles of WT (45%, P

Kristensen, Jonas MØller; Treebak, Jonas Thue

2014-01-01

138

Enhancement of electrical characteristics and reliability in crystallized ZrO{sub 2} gate dielectrics treated with in-situ atomic layer doping of nitrogen  

Energy Technology Data Exchange (ETDEWEB)

The crystallized ZrO{sub 2} high-K gate dielectrics treated with in-situ atomic layer doping of nitrogen using remote N{sub 2} and NH{sub 3} plasma were investigated, to suppress the capacitance equivalent thickness (CET), leakage current density (J{sub g}), and interfacial state density (D{sub it}). The stress-induced leakage current (SILC) was reduced significantly as well. The tetragonal/cubic phase of ZrO{sub 2} was formed by post metallization annealing at a low temperature of 450 °C to offer a high dielectric constant of the gate oxide. The in-situ atomic layer doping of nitrogen using the remote NH{sub 3} plasma contributes to the deactivation of the oxygen vacancies and the well passivation of D{sub it}. Accordingly, a suppressed J{sub g} of 4.79 × 10{sup ?5} A cm{sup ?2} and D{sub it} of 3.96 × 10{sup 11} cm{sup ?2} eV{sup ?1} were realized in the crystallized ZrO{sub 2} gate oxide with a low CET of 1.35 nm. The gate dielectrics were also optically examined by the photoluminescence from the high-K/Si interface, indicating that the D{sub it} is highly correlated with the hydrogen passivation originating from the remote NH{sub 3} plasma. The results indicate that in-situ atomic layer doping of nitrogen is an applicable and effective technique to improve the electrical properties of crystallized gate dielectrics in the advanced metal-oxide-semiconductor devices.

Huang, Jhih-Jie; Huang, Li-Tien; Tsai, Meng-Chen [Department of Materials Science and Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China); Lee, Min-Hung [Institute of Electro-Optical Science and Technology, National Taiwan Normal University, Taipei 11677, Taiwan (China); Chen, Miin-Jang, E-mail: mjchen@ntu.edu.tw [Department of Materials Science and Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China); Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei 10617, Taiwan (China); National Nano Device Laboratories, Hsinchu 30078, Taiwan (China)

2014-06-01

139

Polyaniline-decorated {001} facets of Bi2O2CO3 nanosheets: in situ oxygen vacancy formation and enhanced visible light photocatalytic activity.  

Science.gov (United States)

Polyaniline (PANI)-decorated {001} facets of Bi2O2CO3 nanosheets were synthesized by a low-temperature chemical method. We demonstrate that the strong interfacial interactions between Bi2O2CO3 {001} facets and PANI could promote in situ formation of oxygen vacancy at the interface confirmed by both density functional theory calculations and electron spin resonance experiments, which is due to the high oxygen density characteristic of Bi2O2CO3 {001} facets. In addition, such interfacial interaction also leads to a 0.38 eV positive shifting of the valence band of Bi2O2CO3. Importantly, the decorated PANI can stabilize these interfacial oxygen vacancies. Therefore, the migration and separation of photogenerated carriers have been improved significantly evidenced by electrochemical impedance spectroscopy, photoluminescence, and nanosecond time-resolved fluorescence-decay spectra, resulting in a 4.5 times higher activity toward photodegradation of Rhodamine B and a 6 times higher photocurrent density compared to their corresponding bare Bi2O2CO3. The finding of the in situ oxygen vacancy formation at the interface could provide some hints for the deep understanding of the interactions between PANI and crystal facets of semiconductors to develop highly efficient photocatalysts. PMID:25495565

Zhao, Ziyan; Zhou, Ying; Wang, Fang; Zhang, Kunhao; Yu, Shan; Cao, Kun

2015-01-14

140

Uranium in situ leaching  

International Nuclear Information System (INIS)

Despite the depressed situation that has affected the uranium industry during the past years, the second Technical Committee Meeting on Uranium In Situ Leaching, organized by the International Atomic Energy Agency and held in Vienna from 5 to 8 October 1992, has attracted a relatively large number of participants. A notable development since the first meeting was that the majority of the contributions came from the actual operators of in situ leaching uranium production. At the present meeting, presentations on operations in the USA were balanced by those of the eastern European and Asian countries. Contributions from Bulgaria, China, Czechoslovakia, Germany (from the operation in the former German Democratic Republic), the Russian Federation and Uzbekistan represent new information not commonly available. In situ leach mining is defined in one of the paper presented as a ''mining method where the ore mineral is preferentially leached from the host rock in place, or in situ, by the use of leach solutions, and the mineral value is recovered. Refs, figs and tabs

141

Two Weeks of Metformin Treatment Enhances Mitochondrial Respiration in Skeletal Muscle of AMPK Kinase Dead but Not Wild Type Mice  

DEFF Research Database (Denmark)

Metformin is used as an anti-diabetic drug. Metformin ameliorates insulin resistance by improving insulin sensitivity in liver and skeletal muscle. Reduced mitochondrial content has been reported in type 2 diabetic muscles and it may contribute to decreased insulin sensitivity characteristic for diabetic muscles. The molecular mechanism behind the effect of metformin is not fully clarified but inhibition of complex I in the mitochondria and also activation of the 5'AMP activated protein kinase (AMPK) has been reported in muscle. Furthermore, both AMPK activation and metformin treatment have been associated with stimulation of mitochondrial function and biogenesis. However, a causal relationship in skeletal muscle has not been investigated. We hypothesized that potential effects of in vivo metformin treatment on mitochondrial function and protein expressions in skeletal muscle are dependent upon AMPK signaling. We investigated this by two weeks of oral metformin treatment of muscle specific kinase dead alpha(2) (KD) AMPK mice and wild type (WT) littermates. We measured mitochondrial respiration and protein activity and expressions of key enzymes involved in mitochondrial carbohydrate and fat metabolism and oxidative phosphorylation. Mitochondrial respiration, HAD and CS activity, PDH and complex I-V and cytochrome c protein expression were all reduced in AMPK KD compared to WT tibialis anterior muscles. Surprisingly, metformin treatment only enhanced respiration in AMPK KD mice and thereby rescued the respiration defect compared to the WT mice. Metformin did not influence protein activities or expressions in either WT or AMPK KD mice. We conclude that two weeks of in vivo metformin treatment enhances mitochondrial respiration in the mitochondrial deficient AMPK KD but not WT mice. The improvement seems to be unrelated to AMPK, and does not involve changes in key mitochondrial proteins.

Kristensen, J. M.; Larsen, S.

2013-01-01

142

Two weeks of metformin treatment enhances mitochondrial respiration in skeletal muscle of AMPK kinase dead but not wild type mice  

DEFF Research Database (Denmark)

Metformin is used as an anti-diabetic drug. Metformin ameliorates insulin resistance by improving insulin sensitivity in liver and skeletal muscle. Reduced mitochondrial content has been reported in type 2 diabetic muscles and it may contribute to decreased insulin sensitivity characteristic for diabetic muscles. The molecular mechanism behind the effect of metformin is not fully clarified but inhibition of complex I in the mitochondria and also activation of the 5'AMP activated protein kinase (AMPK) has been reported in muscle. Furthermore, both AMPK activation and metformin treatment have been associated with stimulation of mitochondrial function and biogenesis. However, a causal relationship in skeletal muscle has not been investigated. We hypothesized that potential effects of in vivo metformin treatment on mitochondrial function and protein expressions in skeletal muscle are dependent upon AMPK signaling. We investigated this by two weeks of oral metformin treatment of muscle specific kinase dead a(2) (KD) AMPK mice and wild type (WT) littermates. We measured mitochondrial respiration and protein activity and expressions of key enzymes involved in mitochondrial carbohydrate and fat metabolism and oxidative phosphorylation. Mitochondrial respiration, HAD and CS activity, PDH and complex I-V and cytochrome c protein expression were all reduced in AMPK KD compared to WT tibialis anterior muscles. Surprisingly, metformin treatment only enhanced respiration in AMPK KD mice and thereby rescued the respiration defect compared to the WT mice. Metformin did not influence protein activities or expressions in either WT or AMPK KD mice.We conclude that two weeks of in vivo metformin treatment enhances mitochondrial respiration in the mitochondrial deficient AMPK KD but not WT mice. The improvement seems to be unrelated to AMPK, and does not involve changes in key mitochondrial proteins.

Kristensen, Jonas MØller; Larsen, Steen

2013-01-01

143

Enhancement of growth and structure properties of YBa2Cu3O7-? thin layers by in situ incorporation of gold nano-clusters  

International Nuclear Information System (INIS)

For most hetero-epitactic growth techniques, structural defects due to the lattice misfit, namely tilts, precipitates or holes, turn out to be limiting factors for the successful fabrication of multilayer systems. A new approach of an in situ growth technique dealing with this problem by incorporation of gold nano-clusters is examined. Therefore, pulsed laser deposition (PLD) of a high-TC YBa2Cu3O7-? (YBCO) layer onto a strontium titanate (STO) template with a temporary interlayer of gold with a well-defined film thickness is investigated. Within this process, the gold interlayer shows nano-clustering behavior. Effects on the properties of structure like crystallographic or surface features of the ablated YBCO layer by variation of the film thickness of the gold and YBCO layers are presented. Moreover, distribution and clustering behavior of the crystallized gold nano-particles as well as the basic superconducting properties of the layer system are analyzed.

144

In situ monitoring  

International Nuclear Information System (INIS)

Systems for in situ analysis of radionuclides around storage areas and nuclear sites are being developed. The development and initial use of an intrinsic Ge system for the determination of Pu and Am in soils were completed. A method based on gamma-ray analysis of grazing animal thyroids was developed as a possible method for U and Th exploration using their 226Ra and 228Ra daughters

145

In-situ abortion  

Energy Technology Data Exchange (ETDEWEB)

Application of in situ recovery methods has only been revealed in the literature up to a point. This study goes beyond that point. High energy input, irregular propagation of heat, costs of maintaining a heat gradient, effects of insulation, costs of myriads of wells, absence of an effective pressure differential, the need for costly well manipulation, problems of wildfire and internal problems such as aquifers and impervious layers are discussed. Problems of layout of wells, opportunity for scalping and high grading and the effect of the enclosing sands are reviewed. Recoveries of the total oil-in-place as low as 3% are indicated. The equivalent of 19 gal of gasoline will be destroyed in the ground to get one gallon out, at a pump price of $2.00 per gal or more. When underground mining is extended into an area of in situ, the desecration will be verified and exposed. Despite all of the evidence, the tragedy is that in situ recovery processes will be allowed.

Johns, R.W.

1977-01-01

146

Continuous delta 1-hydrocortisone dehydrogenation with in situ product recovery.  

Science.gov (United States)

A continuous aerated process for delta 1-hydrocortisone dehydrogenation by polyacrylamide-hydrazide (PAAH) bead-entrapped A. simplex cells was developed. The process allows for stable conversion of 1.6 g l-1 hydrocortisone (x 5 the solubility in water), made possible by the incorporation of selected cosolvent [5% (v/v) triethyleneglycol]. A large difference in substrate and product solubilities in the cosolvent-buffer medium allowed for in situ product recovery in an aerated, fluidized-bed, immobilized-cell reactor by the controlled addition of fine product-adsorbing powder (microcrystalline cellulose). The product was recovered at the reactor outlet as a fine complex with the adsorbent. Stable continuous operation of at least 4 weeks was recorded for a prototype reactor configuration, followed by the exhibition of similar operational stability in a modified version of a commercially available 2.5-l airlift reactor. Our results demonstrate that in addition to an obvious desirable cosolvent effect on substrate solubility enhancement, it may also enable easy in situ product recovery by creating a large gap in the solubilities of the substrate and the product in the cosolvent-containing reaction medium. PMID:1367997

Silbiger, E; Freeman, A

1991-11-01

147

The in-situ decontamination of sand and gravel aquifers by chemically enhanced solubilization of multiple-component DNAPLS with surfactant solutions. Topical report  

Energy Technology Data Exchange (ETDEWEB)

Laboratory, numerical simulation, and field studies have been conducted to assess the potential use of micellar-surfactant solutions to solubilize chlorinated solvents contaminating sand and gravel aquifers. Laboratory studies were conducted at the State University of New York at Buffalo (SUNY) while numerical simulation and field work were undertaken by INTERA Inc. in collaboration with Martin Marietta Energy Systems Inc. at the Paducah Gaseous Diffusion Plant (PGDP) in Kentucky. Ninety-nine surfactants were screened for their ability to solubilize trichloroethene (TCE), perchloroethylene (PCE), and carbon tetrachloride (CTET). Ten of these were capable of solubilizing TCE to concentrations greater than 15,000 mg/L, compared to its aqueous solubility of 1,100 mg/L. Four surfactants were identified as good solubilizers of all three chlorinated solvents. Of these, a secondary alcohol ethoxylate was the first choice for in situ testing because of its excellent solubilizing ability and its low propensity to sorb. However, this surfactant did not meet the Commonwealth of Kentucky`s acceptance criteria. Consequently, it was decided to use a surfactant approved for use by the Food and Drug Administration as a food-grade additive. As a 1% micellar-surfactant solution, this sorbitan monooleate has a solubilization capacity of 16,000 mg TCE/L, but has a higher propensity to sorb to clays than has the alcohol ethoxylate.

NONE

1995-01-01

148

In situ synthesis of hierarchical flower-like Bi2S3/BiOCl composite with enhanced visible light photocatalytic activity  

International Nuclear Information System (INIS)

Novel BiOCl micro-flower was synthesized by a facile method and used as a precursor to produce Bi2S3/BiOCl composites. The Bi2S3/BiOCl composites, synthesized by in situ etching of BiOCl precursor with thiacetamide (TAA) solution, maintain the hierarchical flower-like structure and exhibit a large surface area. X-ray diffraction (XRD), Fourier transform infrared spectrometry (FT-IR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), and UV–vis diffuse reflectance spectroscopy (DRS) were employed to study the structures, morphologies and optical properties of the as-prepared samples. Under visible light (? > 400 nm), the flower-like Bi2S3/BiOCl composite displayed much higher photocatalytic activity than single Bi2S3, BiOCl and 2D plate-like Bi2S3/BiOCl composite for the degradation of rhodamine B (RhB). The increased photocatalytic activity of Bi2S3/BiOCl could be attributed to the formation of the heterostructure between Bi2S3 and BiOCl and large surface area of the hierarchical structure, which effectively separate the photoinduced electron–hole pairs and suppress their recombination.

149

Anode catalysts for enhanced methanol oxidation: An in situ XANES study of PtRu/C and PtMo/C catalysts  

Science.gov (United States)

Pt/C, PtRu/C and PtMo/C electro catalysts were prepared in different compositions by incipient wetness impregnation method. These catalysts were characterized by X-ray diffraction (XRD) and X-ray absorption near-edge structure (XANES) to understand the miscibility into solid solution and to calculate the d-orbital vacancy, respectively. Pt with Ru and Mo forms a single alloy which was confirmed by XRD date. XANES was measured at Pt L II and L III edges and K edges of Ru and Mo to determine the oxidation states of these metals in different compositions. Further calculations of d-orbital vacancy of Pt revealed more information that increasing the Ru or Mo content increases d-orbital vacancy. As Mo oxidizes faster than Ru, magnitude of d-orbital vacancy is high in the case of Ru compared to Mo. In situ XENES study was also conducted in methanol fuel cell to understand the oxidation states and methanol oxidation mechanism.

Mylswamy, S.; Wang, C. Y.; Liu, R. S.; Lee, J.-F.; Tang, M.-J.; Lee, J.-J.; Weng, B.-J.

2005-09-01

150

Significant enhancement of flux pinning in MgB 2/Fe/Cu superconducting wires fabricated by in situ powder-in-tube method  

Science.gov (United States)

Dense MgB 2/Fe/Cu wires with and without Zr doping were successfully prepared through the in situ powder-in-tube (PIT) method. MgB 2/Fe/Cu wires were sintered at 650-850 °C for 2 h in argon. Critical current density ( Jc) of the wires was measured at different temperatures in the magnetic field up to 8 T by standard four probe method. As shown by inductive measurements, the heat treatment temperature has an obvious influence on flux pinning of MgB 2 wire. Also it is found that the flux pinning in MgB 2 wire can be remarkably improved by Zr doping. The microstructure observation for MgB 2 wires shows that MgB 2/Fe/Cu wire with Zr doping has better grain connectivity and higher density than other samples. The mechanism leading to high transport critical current densities of MgB 2/Fe/Cu wires based on MgB 2 grain size is discussed. The results indicate that the Jc can be further improved to meet the requirement for applications by optimizing the process conditions.

Feng, Y.; Yan, G.; Zhao, Y.; Zhang, P. X.; Mossang, E.; Sulpice, A.; Zhou, L.

2005-10-01

151

In situ synthesis of hierarchical flower-like Bi{sub 2}S{sub 3}/BiOCl composite with enhanced visible light photocatalytic activity  

Energy Technology Data Exchange (ETDEWEB)

Novel BiOCl micro-flower was synthesized by a facile method and used as a precursor to produce Bi{sub 2}S{sub 3}/BiOCl composites. The Bi{sub 2}S{sub 3}/BiOCl composites, synthesized by in situ etching of BiOCl precursor with thiacetamide (TAA) solution, maintain the hierarchical flower-like structure and exhibit a large surface area. X-ray diffraction (XRD), Fourier transform infrared spectrometry (FT-IR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), and UV–vis diffuse reflectance spectroscopy (DRS) were employed to study the structures, morphologies and optical properties of the as-prepared samples. Under visible light (? > 400 nm), the flower-like Bi{sub 2}S{sub 3}/BiOCl composite displayed much higher photocatalytic activity than single Bi{sub 2}S{sub 3}, BiOCl and 2D plate-like Bi{sub 2}S{sub 3}/BiOCl composite for the degradation of rhodamine B (RhB). The increased photocatalytic activity of Bi{sub 2}S{sub 3}/BiOCl could be attributed to the formation of the heterostructure between Bi{sub 2}S{sub 3} and BiOCl and large surface area of the hierarchical structure, which effectively separate the photoinduced electron–hole pairs and suppress their recombination.

Jiang, Saihua [State Key Laboratory of Fire Science, University of Science and Technology of China, Jinzhai Road 96, Hefei, Anhui 230026 (China); Department of Civil and Architectural Engineering, City University of Hong Kong and USTC-CityU Joint Advanced Research Centre, Suzhou (China); Zhou, Keqing [State Key Laboratory of Fire Science, University of Science and Technology of China, Jinzhai Road 96, Hefei, Anhui 230026 (China); Shi, Yongqian [State Key Laboratory of Fire Science, University of Science and Technology of China, Jinzhai Road 96, Hefei, Anhui 230026 (China); Department of Civil and Architectural Engineering, City University of Hong Kong and USTC-CityU Joint Advanced Research Centre, Suzhou (China); Lo, Siuming [Department of Civil and Architectural Engineering, City University of Hong Kong and USTC-CityU Joint Advanced Research Centre, Suzhou (China); Xu, Haiyan [Nano Science and Technology Institute, University of Science and Technology of China, Jinzhai Road 96, Hefei, Anhui 230027 (China); Hu, Yuan, E-mail: yuanhu@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, Jinzhai Road 96, Hefei, Anhui 230026 (China); Gui, Zhou, E-mail: zgui@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, Jinzhai Road 96, Hefei, Anhui 230026 (China)

2014-01-30

152

Determination of HER-2 status on FNAC material from breast carcinomas using in situ hybridization with dual chromogen visualization with silver enhancement (dual SISH  

Directory of Open Access Journals (Sweden)

Full Text Available During the last years, HER-2 status kits and protocols for chromogen visualization of hybridization signals have come on the market. The first generation using chromogen visualization used single color probes. The second generation, now emerging on the market, uses dual chromogen visualization. The aim of this study has been to test a new dual color chromogen kit (Ventana INFORM HER2 Dual Colour ISH Roche ® and compare the results with our in-house method(s. The material consisted primarily of cytological material from invasive breast carcinomas in 49 women. Dual SISH was done on all 49 cytological and histological specimens. The histological specimens were treated according to the manufacturer?s recommendations. The procedure was modified in several steps in order to adapt it to the cytological material. Hybridization failed in two cytological specimens. Dual SISH showed concordant results on cytological and histological material as to amplified/not amplified. The included cases had the same HER-2 expression in the invasive and the in situ components on histology. Four IDC showed HER-2 amplification (8.5%. Polysomy was found in two cases. All dual SISH results except for one concurred with the results of the in-house method(s (1/47=2.1%. The dual SISH is suitable for cytological examination of HER-2 status. The protocol must be optimized for cytological material.

Beraki Elsa

2010-01-01

153

Determination of HER-2 status on FNAC material from breast carcinomas using in situ hybridization with dual chromogen visualization with silver enhancement (dual SISH).  

Science.gov (United States)

During the last years, HER-2 status kits and protocols for chromogen visualization of hybridization signals have come on the market. The first generation using chromogen visualization used single color probes. The second generation, now emerging on the market, uses dual chromogen visualization. The aim of this study has been to test a new dual color chromogen kit (Ventana INFORM HER2 Dual Colour ISH Roche(®)) and compare the results with our in-house method(s). The material consisted primarily of cytological material from invasive breast carcinomas in 49 women. Dual SISH was done on all 49 cytological and histological specimens. The histological specimens were treated according to the manufacturer's recommendations. The procedure was modified in several steps in order to adapt it to the cytological material. Hybridization failed in two cytological specimens. Dual SISH showed concordant results on cytological and histological material as to amplified/not amplified. The included cases had the same HER-2 expression in the invasive and the in situ components on histology. Four IDC showed HER-2 amplification (8.5%). Polysomy was found in two cases. All dual SISH results except for one concurred with the results of the in-house method(s) (1/47=2.1%). The dual SISH is suitable for cytological examination of HER-2 status. The protocol must be optimized for cytological material. PMID:20976182

Beraki, Elsa; Sauer, Torill

2010-01-01

154

An in situ SEM-FIB-based method for contrast enhancement and tomographic reconstruction for structural quantification of porous carbon electrodes.  

Science.gov (United States)

A new in situ Scanning Electron Microscope-Focused Ion Beam-based method to study porous carbon electrodes involving Pt filling of pores from gaseous precursors has been demonstrated to show drastically improved image contrast between the carbon and porous phases when compared with the Si-resin vacuum-impregnation method. Whereas, the latter method offered up to 20% contrast, the new method offers remarkably higher contrast (42%), which enabled fast semi-automated demarcation of carbon boundaries and subsequent binarization of the images with very high fidelity. Tomographic reconstruction of the porous carbon electrode was then obtained from which several morphological parameters were quantified. The porosity was found to be 72±2%. The axial and radial tortuosites were 1.45±0.04 and 1.43±0.04, respectively. Pore size, which is defined to be the distance from the medial axis of the pore to the nearest solid boundary, was quantified. Average pore size determined from the pore size distribution was 90 nm and the corresponding 1 sigma ranges from 45 to 134 nm. Surface-to-volume ratio of the carbon phase was 46.5 µm(-1). The ratio of total surface area to the total volume of electrode including pores (i.e., specific surface area) was 13 µm(-1). PMID:25088604

Eswara-Moorthy, Santhana K; Balasubramanian, Prasanth; van Mierlo, Willem; Bernhard, Jörg; Marinaro, Mario; Wohlfahrt-Mehrens, Margret; Jörissen, Ludwig; Kaiser, Ute

2014-10-01

155

Time-resolved in situ detection of CO in a shock tube using cavity-enhanced absorption spectroscopy with a quantum-cascade laser near 4.6 µm.  

Science.gov (United States)

Cavity-enhanced absorption spectroscopy (CEAS) using a mid-infrared DFB quantum-cascade laser is reported for sensitive time-resolved (10 ?s) in situ CO measurements in a shock tube. Off-axis alignment and fast scanning of the laser wavelength were used to minimize coupling noise in a low-finesse cavity. An absorption gain factor of 91 was demonstrated, which enabled sub-ppm detection sensitivity for gas temperatures of 1000-2100K in a 15 cm diameter shock tube. This substantial improvement in detection sensitivity compared to conventional single-pass absorption measurements, shows great potential for the study of reaction pathways of high-temperature combustion kinetics mechanisms in shock tubes. PMID:25322031

Sun, Kai; Wang, Shengkai; Sur, Ritobrata; Chao, Xing; Jeffries, Jay B; Hanson, Ronald K

2014-10-01

156

Plasma Cell Enrichment Enhances Detection of High-Risk Cytogenomic Abnormalities by Fluorescence In Situ Hybridization and Improves Risk Stratification of Patients With Plasma Cell Neoplasms  

Science.gov (United States)

Context Methods for plasma cell enrichment in bone marrow (BM) specimens can increase the sensitivity of fluorescence in situ hybridization (FISH) for detecting cytogenomic abnormalities, but there is no published report using these methods to evaluate high-risk cytogenomic abnormalities in patients with treated plasma cell neoplasms (PCN) and clinicopathologic data in follow-up. Objective To evaluate the utility of plasma cell enrichment combined with FISH and follow-up data for high-risk cytogenomic abnormalities in post-therapy PCN patients. Design twenty-eight PCN patients with 22 treated were included in this study. Plasma cells were enriched in BM aspirates using a magnetic cell-sorting procedure to select CD138+ cells. Probes were chosen to assess for del(17p13/TP53), del(13q14/RB1), 1q21/CKS1B gain, IgH/FGFR3 and IgH/MAF. Clinicopathologic data were collected during clinical follow-up after plasma cell enrichment. Results Plasma cells in non-enriched specimens ranged from 1%–28% (median, 8%) compared with 28%–96% (median, 73%) in enriched specimens (p<0.0001). In a subset of treated-patients in clinical remission, FISH detected high-risk cytogenomic abnormalities only in plasma cell enriched samples. This approach also detected abnormalities in cases of solitary plasmacytoma and monoclonal gammopathy of undetermined significance. Conclusions Plasma cell enrichment of BM samples increases FISH sensitivity to detect high-risk cytogenomic abnormalities, particularly in treated-patients, and these results, in combination with data from clinical follow-up, can be of value to improve risk stratification and patient management. PMID:23627452

Lu, Gary; Muddasani, Ramya; Orlowski, Robert Z.; Abruzzo, Lynne V.; Qazilbash, Muzaffar H.; You, M. James; Wang, Yaping; Zhao, Ming; Chen, Su; Glitza, Isabella Claudia; Medeiros, L. Jeffrey

2015-01-01

157

In situ measurements of plasma drift velocity and enhanced NO(+) in the auroral electroject by the Bennett spectrometer on AE-C  

Science.gov (United States)

Simultaneous measurements of ion composition and plasma drift velocity by the Bennett mass spectrometer on the Atmosphere Explorer-C satellite reveal a direct correlation between enhancements in NO(+) concentration and ion drift velocity in the southern auroral oval. Low altitude (137 to 250 km) nighttime data reveal a region of westward plasma flow at velocities up to 1.3 km/s between 62 deg and 68 deg invariant latitude, with corresponding NO(+) enhancements of up to a factor of 25. A narrow region of reverse flow at approximately 0.9 km/s was also measured. These drift observations are consistent with convective flow patterns derived from electric field measurements, and their correlation with NO(+) appears to support the suggestion that NO(+) enhancements would be expected in regions of drift owing to the dependence on ion energy of the reaction O(+) + N2 yields NO(+) + N.

Brinton, H. C.

1974-01-01

158

In situ measurements of plasma drift velocity and enhanced NO/+/ in the auroral electrojet by the Bennett spectrometer on AE-C. [Atmosphere Explorer-C satellite  

Science.gov (United States)

Simultaneous measurements of ion composition and plasma drift velocity by the Bennett mass spectrometer on the Atmosphere Explorer-C satellite reveal a direct correlation between enhancements in NO(+) concentration and ion drift velocity in the southern auroral oval. Low altitude (137 to 250 km) data obtained between 1700 and 2400 hr magnetic local time on October 22, 1974, reveal a region of westward plasma flow at velocities up to 1.3 km/s between 62 and 68 deg invariant latitude, with corresponding NO(+) enhancements of up to a factor of 20. A narrow region of reverse flow at about 0.9 km/s was also measured. These drift observations are consistent with convective flow patterns derived from electric field measurements, and their correlation with NO(+) appears to support the suggestion that NO(+) enhancements would be expected in regions of drift owing to the dependence on ion energy of the reaction O(+) + N2 yields NO(+) + N.

Brinton, H. C.

1975-01-01

159

In situ breast cancer  

International Nuclear Information System (INIS)

In situ breast cancer, particularly the ductal type, is increasing in frequency in the developed countries as well as in Ecuador, most probably. These lesions carry a higher risk of developing a subsequent invasive cancer. Treatment has changed recently due to results of randomized studies, from classical mastectomy to conservative surgery associated to radiotherapy. The Van Nuys Prognostic Index is currently the most usual instrument to guide diagnosis and treatment. Tamoxifen seems to decrease significantly the risk of tumor recurrence after initial treatment. (The author)

160

Significant plasticity enhancement of ZrCu-based bulk metallic glass composite dispersed by in situ and ex situ Ta particles  

International Nuclear Information System (INIS)

Graphical abstract: Confinement zone of Ta particles provide a plastic shielding to obstruct shear banding and so as to significantly increase the plasticity of Zr-based BMGC. Evidence of remarkable plasticity improvement of Zr-based BMGC dispersed by the combination of in situ and ex situ Ta particles can be seen from the stress–strain curve (a) as well as the fractured samples of monolithic BMG ((b): brittle fracture) and BMGC ((c): severe plastic deformation). Highlights: ? Shear bands are arrested by the interface of glassy matrix/Ta in the Zr-based BMGCs. ? Ta particles of BMGC distributed as a semi-uniform confinement zone. ? Confinement zone exhibits smaller size than plastic zone of crack-tip in the BMGC. ? Confinement zone of Ta provide a plastic shielding to obstruct shear banding. ? Plasticity can be improved from 0% (monolithic BMG) to 44% plastic strain (BMGC). - Abstract: Using two-step arc melting process and suction casting, the Zr47.3Cu32Al8Ag8Ta4Si0.7-based bulk metallic glass composites (BMGCs) rods with ex situ added micro-sized Ta particles have been successfully fabricated. The structure and thermal properties of these BMGCs samples were examined by differential scanning calorimeter (DSC) and X-ray diffraction (XRD). It was found that these BMGCs with ex situ added Ta exhibit similar thermal properties in comparison with their base alloy counterpart, with relatively higunterpart, with relatively high glass forming ability (GFA). For the mechanical study, the results of compression test show that more than 25% compressive plastic strain and 1800 MPa fracture strength at room temperature can be obtained for the 2 mm diameter rod of the ZrCu-based BMGC ex situ added 6 and 9 vol.% Ta particles, respectively. Images from SEM on the fractured surfaces show that the homogeneously distributed Ta particles (20 ± 8 ?m) would form semi-uniform confinement zones to restrict the shear band propagation. In other words, the inter-particle free space and the size of confinement zone (mean free path of shear bands) is apparently the controlling factor in affecting the plasticity of BMGCs.

161

Significant plasticity enhancement of ZrCu-based bulk metallic glass composite dispersed by in situ and ex situ Ta particles  

Energy Technology Data Exchange (ETDEWEB)

Graphical abstract: Confinement zone of Ta particles provide a plastic shielding to obstruct shear banding and so as to significantly increase the plasticity of Zr-based BMGC. Evidence of remarkable plasticity improvement of Zr-based BMGC dispersed by the combination of in situ and ex situ Ta particles can be seen from the stress-strain curve (a) as well as the fractured samples of monolithic BMG ((b): brittle fracture) and BMGC ((c): severe plastic deformation). Highlights: Black-Right-Pointing-Pointer Shear bands are arrested by the interface of glassy matrix/Ta in the Zr-based BMGCs. Black-Right-Pointing-Pointer Ta particles of BMGC distributed as a semi-uniform confinement zone. Black-Right-Pointing-Pointer Confinement zone exhibits smaller size than plastic zone of crack-tip in the BMGC. Black-Right-Pointing-Pointer Confinement zone of Ta provide a plastic shielding to obstruct shear banding. Black-Right-Pointing-Pointer Plasticity can be improved from 0% (monolithic BMG) to 44% plastic strain (BMGC). - Abstract: Using two-step arc melting process and suction casting, the Zr{sub 47.3}Cu{sub 32}Al{sub 8}Ag{sub 8}Ta{sub 4}Si{sub 0.7}-based bulk metallic glass composites (BMGCs) rods with ex situ added micro-sized Ta particles have been successfully fabricated. The structure and thermal properties of these BMGCs samples were examined by differential scanning calorimeter (DSC) and X-ray diffraction (XRD). It was found that these BMGCs with ex situ added Ta exhibit similar thermal properties in comparison with their base alloy counterpart, with relatively high glass forming ability (GFA). For the mechanical study, the results of compression test show that more than 25% compressive plastic strain and 1800 MPa fracture strength at room temperature can be obtained for the 2 mm diameter rod of the ZrCu-based BMGC ex situ added 6 and 9 vol.% Ta particles, respectively. Images from SEM on the fractured surfaces show that the homogeneously distributed Ta particles (20 {+-} 8 {mu}m) would form semi-uniform confinement zones to restrict the shear band propagation. In other words, the inter-particle free space and the size of confinement zone (mean free path of shear bands) is apparently the controlling factor in affecting the plasticity of BMGCs.

Li, J.B. [Department of Mechanical Engineering, National Central University, Chung-Li 32001, Taiwan (China); Jang, J.S.C., E-mail: jscjang@ncu.edu.tw [Department of Mechanical Engineering, National Central University, Chung-Li 32001, Taiwan (China); Institute of Materials Science and Engineering, National Central University, Chung-Li 32001, Taiwan (China); Li, C. [Department of Mechanical Engineering, National Central University, Chung-Li 32001, Taiwan (China); Jian, S.R.; Tsai, P.H. [Department of Materials Science and Engineering, I-Shou University, Kaohsiung 840, Taiwan (China); Hwang, J.D. [Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu 31040, Taiwan (China); Huang, J.C. [Department of Materials and Optoelectronic Science, Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Nieh, T.G. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States)

2012-08-15

162

Carbon doping as an effective way to enhance the superconducting properties of mechanically alloyed in-situ MgB2  

International Nuclear Information System (INIS)

Up to now, carbon doping is the only reliable way to enhance the superconducting properties of Mg2 significantly. Due to the substitution of carbon on boron sites of the lattice, increased impurity scattering results in an enhanced upper critical field. Subsequently, an improved high field jc-performance of carbon-doped MgB2 is observed. Among the plethora of carbon-containing compounds studied so far, nanostructured carbon and carbon nanotubes (CNT) are potentially the most promising materials. Especially the elongated microstructural features of CNTs may additionally function as artificial pinning centers. In this work, the impact different carbon sources has on the structural and superconducting properties of nanocrystalline MgB2 bulk samples and tapes is discussed. Precursor powders of carbon-doped MgB2 were produced by mechanical alloying. In order to preserve the microstructural features of the CNTs, the standard processing procedure was modified.

163

A verification of the high density after contrast enhancement in the 2nd week in cerebroischemic lesion  

International Nuclear Information System (INIS)

To determine the indication, it is necessary to make clear the relation among the Stage (time and course), the Strength, the Pathogenesis, and the Effects of the operation in these diseases (SSPE relation). In this report, we focused on the High Density of CT after the contrast enhancement in the cases of ischemic lesions (the High Density was named ''Ribbon H. D.''). Seventeen cases of Ribbon H. D. in fresh infarctions were verified concerning the time of the appearance of the H. D., the features of its location and nature, and the histological findings. The results were as follows: The Ribbon H. D. appeared in the early stage of infarctions, and had its peak density at the end of the 2nd week after the onset. The Ribbon H. D. was mostly located along the cortical line, showing a ribbon-like band. The Ribbon H. D. did not appear in the sharply demarcated coagulation necrosis in the early stage or in the defined Low Density (L. D.) in the late stage of infarctions. Although the Ribbon H. D. shows the extravasation of contrast media, it does not necessarily show the existence of the hemorrhagic infarction. Some part of the Ribbon H. D. changes to a well-defined L. D. and the rest of the part becomes relative isodensity in the late stage. This change corresponds to the change in the incomplete necrosis which is afterwards divided into a resolution with a cystic cavity and the glial replacement in the late stage. In conclusion, it is possible to understand that the Ribbot is possible to understand that the Ribbon H. D. corresponds to the lesion of an incomplete necrosis, with neovascularization, in the early stage of infarctions. Therefore, in addition to the present indication of a by-pass operation (TIA, RIND), this incomplete necrosis (Ribbon H. D.), its surrounding area and just before the appearance of the Ribbon H. D. might be another indication of the operation. (author)

164

In situ investigation of the calcium-induced proteolytic and salting-in mechanisms causing tenderization in calcium-enhanced muscle.  

Science.gov (United States)

The objective of this experiment was to explore the mechanism(s) of calcium-induced tenderization in calcium-enhanced beef muscle. At 72 h postmortem, beef strip loins (n=15) were injected (9% by weight) with 0.0, 0.05, 0.1, 0.2, or 0.4 M calcium chloride (CaCl(2)) with and without 0.05 M zinc chloride (ZnCl(2)), and aged until 15 days postmortem. Warner-Bratzler shear force peak values indicated that addition of ZnCl(2) drastically inhibited tenderization; however, enhancement with CaCl(2) still tended to reduce shear values (P=0.07; 0.55 kg) when ZnCl(2) was present. In the absence of ZnCl(2), the 0.2 and 0.4 M CaCl(2) treatments were 18.9 and 32.1% more (Ptreatment. SDS-PAGE indicated that addition of zinc reduced breakdown of troponin-T into ?31 and ?28 kDa components. Transmission electron micrographs indicated that addition of CaCl(2) without ZnCl(2) caused more frequent Z-line fractures and increased lateral spreading of myofibrils. These results suggest that both calcium-activated enzymatic activity and a non-enzymatic salting-in effect contributed to tenderization of calcium-enhanced muscle. However, the enzymatic mechanism reduced toughness 2.9- to 7.5-fold more than the non-enzymatic mechanism. Calcium-activated enzymatic degradation appears to be the major tenderization mechanism and non-enzymatic salting-in of calcium ions appears to be a minor tenderization mechanism, even at high calcium concentrations. PMID:22063933

Lawrence, T E; Dikeman, M E; Stephens, J W; Obuz, E; Davis, J R

2004-01-01

165

In situ leaching  

International Nuclear Information System (INIS)

The present invention relates to in-situ leaching of uranium, particularly employing an acidic leach liquor containing an oxidant, and especially in respect of ores containing significant amounts of transition metals that act as catalysis for peroxidant decomposition. When hydrogen peroxide is used as oxidant under such conditions it decomposes leading to the formation of gas bubbles and exaxerbation of ore-blinding, and a reduction in the efficiency of extracti of uranium. The present invention employs peroxymonosulphuric acid as oxidant and thereby ameliorates the problems aforesaid. Preferably, additionally, sulphuric acid is present in the leach liquor and in many preferred embodiments the peroxumonosulphuric acid concentration is from 0.001 to 0.03 moles/litre and the sulphuric acid from 0.025 to 0.075 moles/litre

166

In-situ leaching  

International Nuclear Information System (INIS)

The present invention relates to in-situ leaching of uranium, particularly employing an acidic leach liquor containing an oxidant, and especially in respect of ores containing significant amounts of transition metals that act as catalysts for peroxidant decomposition. When hydrogen peroxide is used as oxidant under such conditions it decomposes leading to the formation of gas bubbles and exacerbation of ore-blinding, and a reduction in the efficiency of extraction of uranium. The present invention employs peroxymonosulphuric acid as oxidant and thereby ameliorates the problems aforesaid. Preferably, additionally, sulphuric acid is present in the leach liquor and in many preferred embodiments the peroxymonosulphuric acid concentration is from 0.001 to 0.03 moles/liter and the sulphuric acid from 0.025 to 0.075 moles/liter

167

In situ controlled sputtering deposition of gold nanoparticles on MnO2 nanorods as surface-enhanced Raman scattering substrates for molecular detection.  

Science.gov (United States)

Single-crystal tetragonal ?-MnO2 nanorods with different amounts of gold nanoparticles (NPs) attached were successfully prepared by a facile sputtering deposition technique. Initially, the morphology and crystal structure of the bare ?-MnO2 nanorods synthesized via a hydrothermal approach were investigated. Then, the amount of gold NPs at different sputtering times was analyzed. It was confirmed that the amount of the decorated gold NPs increased with the lengthening of the sputtering time until they completely covered the ?-MnO2 nanorods. Theoretical calculation results indicated the advantages of the composite structure by showing the enhanced electromagnetic fields around both the bare ?-MnO2 nanorods and the gold NP decorated ones. The surface-enhanced Raman scattering (SERS) efficiency of these nanocomposites was evaluated using methylene blue and 4-mercaptobenzoic acid as Raman probe molecules. It was found that the SERS intensity of the substrates strongly depended on the degree of aggregation of the gold NPs. Uniform SERS signals across the entire surface of these samples were obtained. Moreover, a typical chemical toxin, methyl parathion, was effectively detected over a broad concentration range from 1 × 10(-3) to 100 ppm using the gold NP decorated ?-MnO2 nanorods, suggesting this hybrid structure is highly valuable for further applications on the rapid detection of organic environmental pollutants. PMID:25812162

Jiang, Tao; Zhang, Li; Jin, Han; Wang, Xiaolong; Zhou, Jun

2015-04-01

168

In situ-toughened silicon carbide  

International Nuclear Information System (INIS)

A new processing strategy based on atmospheric pressure sintering is presented for obtaining dense SiC-based materials with microstructures consisting of (1) uniformly distributed elongate-shaped ?-SiC grains and (2) relatively high amounts (20 vol%) of second-phase yttrium aluminum garnet (YAG). This strategy entails the sintering of ?-SiC powder doped with ?-SiC, Al2O3, and Y2O3. The Al2O3 and Y2O3 aid in the liquid-phase sintering of SiC and form in situ YAG, which has a significant thermal expansion mismatch with SiC. During a subsequent grain-growth heat treatment, it is postulated that the ?-SiC ''seeds'' assist in controlling in situ growth of the elongated ?-SiC grains. The fracture pattern in the in situ-toughened SiC is intergranular with evidence of copious crack-wake bridging, akin to toughened Si3N4 ceramics. The elongate nature of the ?-SiC grains, together with the high thermal-residual stresses in the microstructure, enhance the observed crack-wake bridging. This bridging accounts for a measured twofold increase in the indentation toughness of this new class of in situ-toughened SiC relative to a commercial SiC

169

Green synthesis of Pt-on-Pd bimetallic nanodendrites on graphene via in situ reduction, and their enhanced electrocatalytic activity for methanol oxidation  

International Nuclear Information System (INIS)

Graphical abstract: - Highlights: • Porous 3D dendrite-like structure of Pt-on-Pd bimetallic nanostructures supported on graphene were prepared. • The surface of nanostructures was very “clean” because of the surfactant-free formation process and the use of green reagent. • The hetero-nanostructures showed excellent electrocatalytic performance in methanol oxidation. - Abstract: A green synthesis of Pt-on-Pd bimetallic nanodendrites supported on graphene (GPtPdNDs) with a Pd interior and a dendrite-like Pt exterior was achieved using a two-step preparation, mixing graphene and PdCl42? first, then adding PtCl42? and ethanol without any other solvent. The morphology, structure and composition of the thus-prepared GPtPdNDs were characterized by transmission electron microscopy (TEM), high resolution TEM, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. Because no halide ions (refer in particular to Br-, I?) or surfactant was involved in the synthesis, the prepared GPtPdNDs were directly modified onto a glassy carbon electrode and showed excellent electrocatalytic performance in methanol oxidation without any pretreatments. Moreover, with the special structure of PtPdNDs and the synergetic effects of Pt and Pd and the enhanced electron transfer by graphene, the GPtPdNDs composites exhibited higher electrocatalytic activity and better tolerance to Pt nanoparticles supported on graphene (GPtNPs) and Pt/C for methanol oxidation

170

Modeling in situ vitrification  

International Nuclear Information System (INIS)

In Situ Vitrification (ISV) process is being assessed by the Idaho National Engineering Laboratory (INEL) to determine its applicability to transuranic and mixed wastes buried at INEL'S Subsurface Disposal Area (SDA). This process uses electrical resistance heating to melt waste and contaminated soil in place to produce a durable glasslike material that encapsulates and immobilizes buried wastes. This paper outlines the requirements for the model being developed at the INEL which will provide analytical support for the ISV technology assessment program. The model includes representations of the electric potential field, thermal transport with melting, gas and particulate release, vapor migration, off-gas combustion and process chemistry. The modeling objectives are to help determine the safety of the process by assessing the air and surrounding soil radionuclides and chemical pollution hazards, the nuclear criticality hazard, and the explosion and fire hazards, help determine the suitability of the ISV process for stabilizing the buried wastes involved, and help design laboratory and field tests and interpret results. 3 refs., 2 figs., 1 tab

171

Correlation between Active Center Structure and Enhanced Dioxygen Binding in Co(salen) Nanoparticles: Characterization by In Situ Infrared, Raman, and X-ray Absorption Spectroscopies  

Energy Technology Data Exchange (ETDEWEB)

The structure and ligand environment of Co(salen) nanoparticles and unprocessed Co(salen) have been determined by the combined application of infrared, Raman, X-ray absorption near edge structure (XANES), and extended X-ray absorption fine structure (EXAFS) spectroscopies, and X-ray diffraction (XRD) experiments before and during interaction with O2. The Co(salen) nanoparticles were prepared by the precipitation with compressed antisolvent (PCA) technique using commercially obtained Co(salen) [denoted as unprocessed Co(salen)] as the parent compound. The unprocessed Co(salen) particles exist as dimer species with a square-pyramidal coordination geometry that display no measurable O2 binding at room temperature. In sharp contrast, the Co(salen) nanoparticles show near-stoichiometric O2 adsorption, as demonstrated by microbalance gas binding experiments. The spectroscopy results indicate the presence of CoII centers with distorted tetrahedral geometry in the Co(salen) nanoparticles with no evidence of metallic Co clusters, confirmed by the lack of Co-Co contributions at bonding distances in the EXAFS spectra and the presence of characteristic features of CoII in the XANES spectra. The EXAFS data also indicate that there are on average two Co-N and two Co-O bonds with a distance of 1.81 {+-} 0.02 and 1.90 {+-} 0.02 Angstroms, respectively, consistent with typical metal salen structures. Upon O2 binding on the Co(salen) nanoparticles, the XANES results indicate oxidation of the CoII to CoIII, consistent with the vibrational data showing new bands associated with oxygen species bonded to Co centers and the increase in the oxygen coordination number from 1.8 to 2.9 in the EXAFS data. The results indicate that the enhanced O2 binding properties of Co(salen) nanoparticles are related to the unique distorted tetrahedral geometry, which is not observed in the unprocessed samples that contain mainly dimers with square planar geometry. The results presented here provide a fundamental relationship between active center structure and properties of novel molecule-based nanomaterials.

Johnson,C.; Long, B.; Nguyen, J.; Day, V.; Borovik, A.; Subramaniam, B.; Guzman, J.

2008-01-01

172

In situ leaching of uranium  

International Nuclear Information System (INIS)

A process is described for the in-situ leaching of uranium-containing ores employing an acidic leach liquor containing peroxymonosulphuric acid. Preferably, additionally, sulphuric acid is present in the leach liquor. (author)

173

FISH - (Fluoresence In Situ Hybridization)  

Science.gov (United States)

Fluorescence in situ hybridization (FISH) is a process which vividly paints chromosomes or portions of chromosomes with fluorescent molecules. This technique is useful for identifying chromosomal abnormalities and gene mapping.

Darryl Leja (National Human Genome Research Institute REV)

2005-04-04

174

Effectiveness of weekly cognitive stimulation therapy for people with dementia and the additional impact of enhancing cognitive stimulation therapy with a carer training program  

Directory of Open Access Journals (Sweden)

Full Text Available Jennifer Cove,1 Nicola Jacobi,2 Helen Donovan,3 Martin Orrell,4 Josh Stott,5 Aimee Spector5 1Department of Clinical, Educational and Health Psychology, University College London, London, 2Department of Psychology, City University, London, 3Clinical Psychology Service, South Essex Partnership NHS Foundation Trust, Bedford, 4Department of Psychiatry, 5Department of Clinical, Educational and Health Psychology, University College London, London, UKPurpose of the study: Cognitive stimulation therapy (CST is a widely used, evidence-based intervention for people with dementia (PwD. Although designed as a 14 session, twice weekly intervention, many services in the UK deliver CST once a week for 14 weeks. However, this method of delivery has yet to be evaluated. In addition, CST does not include any formal carer training. This study aimed to evaluate the effectiveness of once weekly CST and determine any additional impact when enhanced with a carer training program.Design and methods: A single blind, randomized controlled trial was conducted. Sixty eight PwD and their carers were recruited through three community Memory Assessment Services. PwD and their carers were randomized to one of three conditions: CST plus carer training, CST only, or a wait list control. PwD were administered standardized measures of cognition, quality of life, and quality of relationship with carer at baseline and the 15 week follow-up.Results: There were no baseline differences across the three groups. At follow-up, there were no significant differences between PwD in the three groups on any outcomes. Implications: Weekly CST with or without carer training may not be an effective form of delivery. Several possible explanations for the outcomes are proposed. Weekly CST may not offer the necessary “dose” required to combat decline, and equally the carer training may have been too brief to have made a difference. Services currently offering weekly CST should collect routine outcome data to support its use and provide practice-based evidence.Keywords: Alzheimer’s disease, cognition, intervention, caregiver

Cove J

2014-12-01

175

In Situ Aerosol Detector  

Science.gov (United States)

An affordable technology designed to facilitate extensive global atmospheric aerosol measurements has been developed. This lightweight instrument is compatible with newly developed platforms such as tethered balloons, blimps, kites, and even disposable instruments such as dropsondes. This technology is based on detection of light scattered by aerosol particles where an optical layout is used to enhance the performance of the laboratory prototype instrument, which allows detection of smaller aerosol particles and improves the accuracy of aerosol particle size measurement. It has been determined that using focused illumination geometry without any apertures is advantageous over using the originally proposed collimated beam/slit geometry (that is supposed to produce uniform illumination over the beam cross-section). The illumination source is used more efficiently, which allows detection of smaller aerosol particles. Second, the obtained integral scattered light intensity measured for the particle can be corrected for the beam intensity profile inhomogeneity based on the measured beam intensity profile and measured particle location. The particle location (coordinates) in the illuminated sample volume is determined based on the information contained in the image frame. The procedure considerably improves the accuracy of determination of the aerosol particle size.

Vakhtin, Andrei; Krasnoperov, Lev

2011-01-01

176

In situ assembly of well-dispersed Au nanoparticles on TiO{sub 2}/ZnO nanofibers: A three-way synergistic heterostructure with enhanced photocatalytic activity  

Energy Technology Data Exchange (ETDEWEB)

Graphical abstract: We describe a route to synthesize TiO{sub 2}/ZnO/Au three-way synergistic heterostructure nanofibers with high efficiency photocatalysts. Highlights: Black-Right-Pointing-Pointer Synthesis of tri-component TiO{sub 2}/ZnO/Au nanofibers. Black-Right-Pointing-Pointer TiO{sub 2}/ZnO/Au nanofibers showed excellent photocatalytic activity. Black-Right-Pointing-Pointer Easy photocatalyst separation and reuse. - Abstract: The TiO{sub 2}/ZnO nanofibers embedded by Au nanoparticles (TiO{sub 2}/ZnO/Au NFs) were fabricated by combining the electrospinning technique (for TiO{sub 2}/ZnO nanofibers) and an in situ reduction approach (for Au nanoparticles). X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electronmicroscopy, X-ray photoelectron spectroscopy, UV-vis diffuse reflectance spectroscopy and photoluminescence spectroscopy, were used to characterize the as-synthesized nanofibers. The results showed that small Au nanoparticles (Au NPs) were well dispersed on the TiO{sub 2}/ZnO nanofibers (TiO{sub 2}/ZnO NFs). And, the TiO{sub 2}/ZnO/Au nanofibers showed high charge separation efficiency under ultraviolet excitation, as evidenced by photoluminescence spectra. The photocatalytic studies revealed that the TiO{sub 2}/ZnO/Au NFs exhibited enhanced photocatalytic efficiency of photodegradation of Methyl orange (MO) and 4-nitrophenol (4-NP) compared with the pure TiO{sub 2} nanofibers, ZnO nanofibers and TiO{sub 2}/ZnO NFs under ultraviolet excitation, which might be attributed to the high separation efficiency of photogenerated electron-hole pairs based on the photosynergistic effect among the three components of TiO{sub 2}, ZnO and Au. And, the TiO{sub 2}/ZnO/Au NFs could be easily separated and recycled due to their one-dimensional nanostructural property.

Zhang, Peng [Center for Advanced Optoelectronic Functional Materials Research and Key Laboratory of UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024 (China); Shao, Changlu, E-mail: clshao@nenu.edu.cn [Center for Advanced Optoelectronic Functional Materials Research and Key Laboratory of UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024 (China); Li, Xinghua, E-mail: lixh781@nenu.edu.cn [Center for Advanced Optoelectronic Functional Materials Research and Key Laboratory of UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024 (China); Zhang, Mingyi; Zhang, Xin; Sun, Yangyang; Liu, Yichun [Center for Advanced Optoelectronic Functional Materials Research and Key Laboratory of UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024 (China)

2012-10-30

177

In situ uranium stabilization by microbial metabolites  

Energy Technology Data Exchange (ETDEWEB)

Microbial melanin production by autochthonous bacteria was explored in this study as a means to increase U immobilization in U contaminated soil. This article demonstrates the application of bacterial physiology and soil ecology for enhanced U immobilization in order to develop an in situ, U bio-immobilization technology. We have demonstrated microbial production of a metal chelating biopolymer, pyomelanin, in U contaminated soil from the Tims Branch area of the Department of Energy (DOE), Savannah River Site (SRS), South Carolina, as a result of tyrosine amendments. Bacterial densities of pyomelanin producers were >10{sup 6} cells per g wet soil. Pyomelanin demonstrated U complexing and mineral binding capacities at pH 4 and 7. In laboratory studies, in the presence of goethite or illite, pyomelanin enhanced U sequestration by these minerals. Tyrosine amended soils in a field test demonstrated increased U sequestration capacity following pyomelanin production up to 13 months after tyrosine treatments.

Turick, Charles E. [Environmental Science and Biotechnology, Savannah River National Laboratory, Building 999W, Aiken, SC 29808 (United States)], E-mail: Charles.Turick@srnl.doe.gov; Knox, Anna S. [Environmental Science and Biotechnology, Savannah River National Laboratory, Building 999W, Aiken, SC 29808 (United States); Leverette, Chad L.; Kritzas, Yianne G. [Department of Chemistry and Physics, University of South Carolina Aiken, Aiken, SC 29801 (United States)

2008-06-15

178

In situ uranium stabilization by microbial metabolites  

International Nuclear Information System (INIS)

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

179

Combined plasma-enhanced-atomic-layer-deposition gate dielectric and in situ SiN cap layer for reduced threshold voltage shift and dynamic ON-resistance dispersion of AlGaN/GaN high electron mobility transistors on 200 mm Si substrates  

Science.gov (United States)

In this work we will present the experimental path followed to optimize the dynamic ON-resistance (RDS-ON) dispersion and to reduce the threshold voltage shift of AlGaN/GaN transistors grown on 200 mm Si wafers. Firstly, it will be demonstrated that a SiN gate dielectric grown by means of plasma enhanced atomic layer deposition (PEALD) instead of rapid thermal chemical vapor deposition (RTCVD) reduces threshold voltage (Vth) shift induced by negative gate bias and the gate leakage. Secondly, the dynamic RDS-ON dispersion of two wafers with same gate dielectric (PEALD SiN) but different in situ metal organic chemical vapor deposition (MOCVD) capping layer, GaN or SiN, is compared. Results will show that the traps at the surface causing the RDS-ON dispersion can drastically be reduced by using in situ MOCVD SiN.

Ronchi, Nicolò; De Jaeger, Brice; Van Hove, Marleen; Roelofs, Robin; Wu, Tian-Li; Hu, Jie; Kang, Xuanwu; Decoutere, Stefaan

2015-04-01

180

In situ biofilm coupon device  

Science.gov (United States)

An apparatus for characterization of in-situ microbial biofilm populations in subsurface groundwater. The device permits biofilm-forming microorganisms to adhere to packing material while emplaced in a groundwater strata, so that the packing material can be later analyzed for quantity and type of microorganisms, growth rate, and nutrient requirements.

Peyton, Brent M. (Kennewick, WA); Truex, Michael J. (Richland, WA)

1997-01-01

181

Polyolefin nanocomposites in situ polymerization  

International Nuclear Information System (INIS)

Polyethylene and polypropylene nanocomposites using grapheme nanosheets and treated chrysotile have been synthesized by in situ polymerization using metallocene catalysts. The fillers have been submitted to acid, thermal and/ou ultrasound treatments before to introduce them into the polymerization reactor. A complete characterization of the fillers has been done. The nanocomposites have been characterized by SEM, TEM, DRX and AFM. The thermal, mechanic -dynamic, mechanical and electrical properties of the nanocomposites are discussed. (author)

182

Polyolefin nanocomposites in situ polymerization  

Energy Technology Data Exchange (ETDEWEB)

Polyethylene and polypropylene nanocomposites using grapheme nanosheets and treated chrysotile have been synthesized by in situ polymerization using metallocene catalysts. The fillers have been submitted to acid, thermal and/ou ultrasound treatments before to introduce them into the polymerization reactor. A complete characterization of the fillers has been done. The nanocomposites have been characterized by SEM, TEM, DRX and AFM. The thermal, mechanic -dynamic, mechanical and electrical properties of the nanocomposites are discussed. (author)

Galland, Griselda Barrera; Fim, Fabiana de C.; Milani, Marceo A.; Silva, Silene P. da; Forest, Tadeu; Radaelli, Gislaine, E-mail: griselda.barrera@ufrgs.br [Universidade Federal do Rio Grande de Sul - UFRGS, Porto Alegre, RS (Brazil); Basso, Nara R.S. [Pontificia Universidade Catolica do Rio Grande do Sul, Porto Alegre, RS (Brazil); Quijada, Raul [Universidad de Chile, Santiago (Chile)

2011-07-01

183

Baseball Weekly  

Science.gov (United States)

USA Today has recently made its Baseball Weekly newspaper available via the Web. Included are stories on major league, minor league, and college baseball, as well as feature articles. Baseball Weekly also presents weekly fantasy league reports, which analyze player statistics in the context of fans who might have the players in a fantasy league -- a league in which "owners" compile teams of major league players and receive points based on those players' ongoing statistics. The fantasy league reports are one of the newspaper's best resources.

184

Noise canceling in-situ detection  

Energy Technology Data Exchange (ETDEWEB)

Technologies applicable to noise canceling in-situ NMR detection and imaging are disclosed. An example noise canceling in-situ NMR detection apparatus may comprise one or more of a static magnetic field generator, an alternating magnetic field generator, an in-situ NMR detection device, an auxiliary noise detection device, and a computer.

Walsh, David O.

2014-08-26

185

Effectiveness of Start to Run, a 6-week training program for novice runners, on increasing health-enhancing physical activity: a controlled study  

Science.gov (United States)

Background The use of the organized sports sector as a setting for health-promotion is a relatively new strategy. In the past few years, different countries have been investing resources in the organized sports sector for promoting health-enhancing physical activity. In the Netherlands, National Sports Federations were funded to develop and implement “easily accessible” sporting programs, aimed at the least active population groups. Start to Run, a 6-week training program for novice runners, developed by the Dutch Athletics Organization, is one of these programs. In this study, the effects of Start to Run on health-enhancing physical activity were investigated. Methods Physical activity levels of Start to Run participants were assessed by means of the Short QUestionnaire to ASsess Health-enhancing physical activity (SQUASH) at baseline, immediately after completing the program and six months after baseline. A control group, matched for age and sex, was assessed at baseline and after six months. Compliance with the Dutch physical activity guidelines was the primary outcome measure. Secondary outcome measures were the total time spent in physical activity and the time spent in each physical activity intensity category and domain. Changes in physical activity within groups were tested with paired t-tests and McNemar tests. Changes between groups were examined with multiple linear and logistic regression analyses. Results In the Start to Run group, the percentage of people who met the Dutch Norm for Health-enhancing Physical Activity, Fit-norm and Combi-norm increased significantly, both in the short- and longer-term. In the control group, no significant changes in physical activity were observed. When comparing results between groups, significantly more Start to Run participants compared with control group participants were meeting the Fit-norm and Combi-norm after six months. The differences in physical activity between groups in favor of the Start to Run group could be explained by an increase in the time spent in vigorous-intensity activities and sports activities. Conclusions Start to Run positively influences levels of health-enhancing physical activity of participants, both in the short- and longer-term. Based on these results, the use of the organized sports sector as a setting to promote health-enhancing physical activity seems promising. PMID:23898920

2013-01-01

186

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

187

Nickel Weeklies  

Science.gov (United States)

A century or so, a nickel could buy a lot of entertainment. One such form of entertainment was the nickel weekly, which featured tales of detectives, Wild West characters, and evil villains. Bowling Green State University has created this thoroughly delightful digital collection of nickel weeklies for consumption by the general public. This collection includes 221 nickel weeklies, and visitors can browse these offerings by title, date, or author. Visitors can zoom in on the cover page of each weekly, or they may also download each title and view them at another more convenient moment. Users looking for a place to start might do well to look over "Adventures of Buffalo Bill from boyhood to manhood" by Colonel Prentiss Ingraham or "California Claude, the love bandit" by Captain Howard Holmes.

188

N-methyl pyrrolidone/bone morphogenetic protein-2 double delivery with in situ forming implants.  

Science.gov (United States)

Bone morphogenetic proteins (BMPs) are growth and differentiation factors involved during development in morphogenesis, organogenesis and later mainly in regeneration processes, in particular in bone where they are responsible for osteoinduction. For more than a decade, recombinant human (rh)BMP-2 has been used in the clinic for lumbar spinal fusion at non-physiological high dosages that appear to be causative for side effects, like male sterility. A possible strategy to reduce the effective amount of rhBMP-2 in the clinic is the co-delivery with an enhancer of BMPs' activity. In an earlier study, we showed that N-methylpyrrolidone (NMP) enhances BMP activity in vitro and in vivo. Here we report on the development of a slow and sustained double delivery of rhBMP-2 and NMP via an in situ forming implant based on poly(lactide-co-glycolide). The results showed that the release of NMP can be adjusted by varying the lactide/glycolide ratio and the polymer's molecular weight. The same applied to rhBMP-2, with release rates that could be sustained from two to three weeks. In the in vivo model of a critical size defect in the calvarial bone of rabbits, the implant containing 50mol% lactide performed better than the one having 75mol% lactide in terms of defect bridging and extent of bony regenerated area. In situ forming implants for the double delivery of the BMP enhancer NMP and rhBMP-2 appear to be promising delivery systems in bone regeneration. PMID:25697800

Karfeld-Sulzer, Lindsay S; Ghayor, Chafik; Siegenthaler, Barbara; de Wild, Michael; Leroux, Jean-Christophe; Weber, Franz E

2015-04-10

189

Intravenous Infusion of Monocytes Isolated from 2-Week-Old Mice Enhances Clearance of Beta-Amyloid Plaques in an Alzheimer Mouse Model  

Science.gov (United States)

Alzheimer’s disease (AD) is characterized by the deposition of ?-amyloid (A?) senile plaques and tau-associated neurofibrillary tangles. Other disease features include neuroinflammation and cholinergic neurodegeneration, indicating their possible importance in disease propagation. Recent studies have shown that monocytic cells can migrate into the AD brain toward A? plaques and reduce plaque burden. The purpose of this study was to evaluate whether the administration of intravenous infusions of ‘young’ CD11b-positive (+) monocytes into an AD mouse model can enhance A? plaque clearance and attenuate cognitive deficits. Peripheral monocytes were isolated from two-week-old wildtype mice using the Pluriselect CD11b+ isolation method and characterized by FACS analysis for surface marker expression and effective phagocytosis of 1 ?m fluorescent microspheres, FITC-Dextran or FITC-A?1–42. The isolated monocytes were infused via the tail vein into a transgenic AD mouse model, which expresses the Swedish, Dutch/Iowa APP mutations (APPSwDI). The infusions began when animals reached 5 months of age, when little plaque deposition is apparent and were repeated again at 6 and 7 months of age. At 8 months of age, brains were analyzed for A?+ plaques, inflammatory processes and microglial (Iba1) activation. Our data show that infusions of two-week-old CD11b+ monocytes into adult APPSwDI mice results in a transient improvement of memory function, a reduction (30%) in A? plaque load and significantly in small (40 ?m) plaques. In addition, we observe a reduction in Iba1+ cells, as well as no marked elevations in cytokine levels or other indicators of inflammation. Taken together, our findings indicate that young CD11b+ monocytes may serve as therapeutic candidates for improved A? clearance in AD. PMID:25830951

Hohsfield, Lindsay A.; Humpel, Christian

2015-01-01

190

Innovative Raman spectroscopic concepts for in situ monitoring of chemicals in seawater  

Science.gov (United States)

Optical sensors based on Raman spectroscopy are suitable for a rapid identification and quantification of pollutants such as Polycyclic Aromatic Hydrocarbons (PAHs). Additionally, Surface enhanced Raman spectroscopy (SERS) has gained increasing attention as a powerful technique for in-situ monitoring of these substances in seawater to achieve limits of detection (LODs) in the sub-nmol/l range. A low-cost method based on electroless plating solution of chloroauric acid (HAuCl4) and hydrogen peroxide (H2O2) was developed in our group to construct a gold island film as SERS substrate to achieve a well reproducible, high sensitive and seawater resistant SERS sensor. The substrates show good resistance against seawater determined by long-term stability tests carried out over 12 weeks of storage of the substrates in artificial seawater. The investigations show that the substrates still have about 50 % of their initial activity after 4 weeks of storage and about 15 % after two months. This type of substrate is reproducible with variability in the SERS intensities of about 8 %. Shifted excitation Raman difference spectroscopy (SERDS) was applied by using a microsystem diode laser emitting at 784.3 nm and 784.8 nm to remove the fluorescence interference and to improve the Raman signals. This combination of SERS and SERDS yields a limit of detection of 1 nmol/l for pyrene which was selected as representative PAH. These quantitative results show that the designed SERS substrates are suitable for the in-situ monitoring of PAHs in the marine environment.

Sowoidnich, Kay; Fernández López, María.; Kronfeldt, Heinz-Detlef

2013-05-01

191

Final report: In situ radio frequency heating demonstration  

Energy Technology Data Exchange (ETDEWEB)

A field demonstration of in situ radio frequency heating was performed at the Savannah River Site (SRS) as part of the US Department of Energy-Office of Technology Development`s Integrated Demonstration. The objective of the demonstration was to investigate the effectiveness of in situ radio frequency (RF) heating as an enhancement to vacuum extraction of residual solvents (primarily trichloroethylene and perchloroethylene) held in vadose zone clay deposits. Conventional soil vacuum extraction techniques are mass transfer limited because of the low permeabilities of the clays. By selectively heating the clays to temperatures at or above 100{degrees}C, the release or transport of the solvent vapors will be enhanced as a result of several factors including an increase in the contaminant vapor pressure and diffusivity and an increase in the effective permeability of the formation with the release of water vapor.

Jarosch, T.R.; Beleski, R.J.; Faust, D.

1994-01-05

192

DOE In Situ Remediation Integrated Program  

International Nuclear Information System (INIS)

The In Situ Remediation Integrated Program (ISRP) supports and manages a balanced portfolio of applied research and development activities in support of DOE environmental restoration and waste management needs. ISRP technologies are being developed in four areas: containment, chemical and physical treatment, in situ bioremediation, and in situ manipulation (including electrokinetics). the focus of containment is to provide mechanisms to stop contaminant migration through the subsurface. In situ bioremediation and chemical and physical treatment both aim to destroy or eliminate contaminants in groundwater and soils. In situ manipulation (ISM) provides mechanisms to access contaminants or introduce treatment agents into the soil, and includes other technologies necessary to support the implementation of ISR methods. Descriptions of each major program area are provided to set the technical context of the ISM subprogram. Typical ISM needs for major areas of in situ remediation research and development are identified

193

In situ remediation integrated program: Development of containment technology  

International Nuclear Information System (INIS)

The In Situ Remediation Integrated Program (ISR IP) is supporting the development of subsurface containment barrier technology for use in site restoration applications at contaminated sites throughout the US Department of Energy (DOE) complex. The types of subsurface barriers being developed include impermeable barriers and sorbent barriers. The specific containment technology projects described in this paper include frozen soil barriers, flowable grout techniques, hydraulic and diffusion barriers, horizontal grout barriers, chemically enhanced barriers, and viscous liquid barriers

194

In situ measurements of neutron multiplying systems  

International Nuclear Information System (INIS)

Historical and recent examples of the application of in situ measurements to provide knowledge for specific operations and general criticality safety guidance are reviewed. The importance of the American National Standard, Safety in Conducting Subcritical Neutron-Multiplication Measurements In Situ, ANSI/ANS-8.6, 1988 is discussed. Examples of possible future applications of in-situ measurements are provided. 4 refs., 4 figs

195

Amplification of chromosomal DNA in situ  

Science.gov (United States)

Amplification of chromosomal DNA in situ to increase the amount of DNA associated with a chromosome or chromosome region is described. The amplification of chromosomal DNA in situ provides for the synthesis of Fluorescence in situ Hybridization (FISH) painting probes from single dissected chromosome fragments, the production of cDNA libraries from low copy mRNAs and improved in Comparative Genomic Hybridization (CGH) procedures.

Christian, Allen T. (Tracy, CA); Coleman, Matthew A. (Livermore, CA); Tucker, James D. (Livermore, CA)

2002-01-01

196

Publishers Weekly  

Science.gov (United States)

Are you interested in learning what forays university presses are making into the world of electronic publishing? Perhaps you'd like a selection of thoughtful weblogs on new literary works? The Publishers Weekly website has all of that covered, and a great deal more. Designed to complement their print publication, the site has a "Latest Stories" section front and center on their homepage. Checking this area out (and perhaps signing up for their RSS feed) is a good way to stay abreast of important developments in the world of publishing. Also on the homepage visitors will find four sections of primary interest: "Blogs", "Talkback", "Podcasts", and "Photos". The "Talkback" frequently features well-reasoned commentary from readers on recent stories and the "Blogs" area includes links to weblogs maintained by Publishers Weekly staff members. Further down the homepage, visitors can expect to find new book reviews and sections dedicated to children's literature, comics, and independent news.

197

In situ treatability test plan  

International Nuclear Information System (INIS)

This document describes the plans for the in situ treatment zone (ISTZ) treatability test for groundwater contaminated with strontium-90. The treatability test is to be conducted at the Hanford Site in Richland, Washington, in a portion of the 100-N Area adjacent to the Columbia River referred to as N-Springs. The purpose of the treatability test is to evaluate the effectiveness of an innovative technology to prevent the discharge of strontium-90 contaminated groundwater into the Columbia River. The ISTZ is a passive technology that consists of placing a treatment agent in the path of the groundwater. The treatment agent must restrict target radioactive contaminants and provide time for the contaminant to decay to acceptable levels. The permeability of the treatment zone must be greater than or equal to that of the surrounding sediments to ensure that the contaminated groundwater flows through the treatment zone agent and not around the agent

198

Brain Week!  

Science.gov (United States)

This week-long exploration of brain structure and function through hands-on experiments and web Treasure Hunts ends with an open inquiry on the brain designed by students. Exploration topics include brain parts and their functions, surface area, optic nerve activity, touch receptors, muscle spindle fibers, motor learning, neuroscientists, and the effects of drugs on the brain. This teaching resource was developed by a K-12 science teacher in the American Physiological SocietyÂ?s 2004 Frontiers in Physiology Program. For more information on this program, please visit www.frontiersinphys.org.

Ms. Rachel Gillis (Arsenal Technical High School)

2005-05-01

199

Enhancement of growth and structure properties of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} thin layers by in situ incorporation of gold nano-clusters  

Energy Technology Data Exchange (ETDEWEB)

For most hetero-epitactic growth techniques, structural defects due to the lattice misfit, namely tilts, precipitates or holes, turn out to be limiting factors for the successful fabrication of multilayer systems. A new approach of an in situ growth technique dealing with this problem by incorporation of gold nano-clusters is examined. Therefore, pulsed laser deposition (PLD) of a high-T{sub C} YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO) layer onto a strontium titanate (STO) template with a temporary interlayer of gold with a well-defined film thickness is investigated. Within this process, the gold interlayer shows nano-clustering behavior. Effects on the properties of structure like crystallographic or surface features of the ablated YBCO layer by variation of the film thickness of the gold and YBCO layers are presented. Moreover, distribution and clustering behavior of the crystallized gold nano-particles as well as the basic superconducting properties of the layer system are analyzed.

Erlebach, Ralf; Huebner, Michael; Christke, Sandra; Grosse, Veit; Schmidl, Frank; Seidel, Paul [Friedrich-Schiller-University Jena, Institute of Solid State Physics, Helmholtzweg 5, 07743 Jena (Germany); Kraeusslich, Juergen [Friedrich-Schiller-University Jena, Institute of Optics and Quantum Electronics, Max-Wien-Platz 1, 07743 Jena (Germany); Rettenmayr, Markus [Friedrich-Schiller-University Jena, Institute of Materials Science and Technology, Loebdergraben 32, 07743 Jena (Germany)

2011-07-01

200

In situ dehydration of yugawaralite  

DEFF Research Database (Denmark)

The structural response of the natural zeolite yugawaralite (CaAl2Si6O16. 4H(2)O) upon thermally induced dehydration has been studied by Rietveld analysis of temperature-resolved powder diffraction data collected in situ in the temperature range 315-791 K using synchrotron radiation. The room-temperature monoclinic structure [Pc, a = 6.73200(9), b = 14.0157(2), c = 10.0607(1) Angstrom, beta = 111.189(1) degrees, Z = 2, at 315 K] has the Ca cations in the channels coordinated to four framework O atoms and to four water molecules, with two of the water sites (OW1 and OW4) showing positional disorder progressively disappearing as the dehydration proceeds. The yugawaralite structure reacts to the release of water molecules with small changes in the Ca-O bond distances and minor distortions of the tetrahedral framework up to about 695 K. Above this temperature the Ca coordination falls below 7 (four framework O atoms and three water molecules) and a major rearrangement in the cation coordination takes place, causing a first order phase transition involving both a large decrease in the cell volume and the change in the space group symmetry. A satisfactory structure model for the high-temperature phase stable in the range 695-791 K could not be obtained because of the complexity of the structure. A model approximately describing the average structure [Pn, a = 12.703(1), b = 13.067(1), c = 9.839(1) Angstrom, beta = 110.894(9), Z = 4, at 749 K] has been used to follow the temperature evolution of the cell parameters in the measured temperature range. This model involves a sixfold coordination of the Ca cations (five framework O atoms and one water molecule). There is no indication of significant structure changes before collapse, likely occurring when the last water molecule is expelled from the structure and the cation coordination drops below 6, as observed in other Ca-rich zeolites (i.e., laumontite, scolecite, mesolite).

Artioli, G.; Ståhl, Kenny

2001-01-01

201

In situ leach: technology and potential  

International Nuclear Information System (INIS)

In-situ leach and solution mining are described with respect to uranium mining. In the technique, leaching fluids dissolve the mineral without having to remove the ore physically from its occurence. In-situ leach can produce uranium at lower costs than other methods. The factors which are important to achieve this are discussed. In-situ leach is only suitable for one type of uranium deposit, a roll-front deposit (deposited from moving groundwater) in a permeable sandstone that must be an aquifer (sandstone filled with water). It is difficult to predict the performance of an in-situ leach project; good engineering techniques are more important than in conventional mining. The processing and subsequent recovery of the uranium are described. Some of the technological improvements in the technique are discussed. The future development of the technique is considered. (U.K.)

202

Molecular Classification of Breast Carcinoma In Situ  

OpenAIRE

Pleomorphic variant of invasive lobular carcinoma (PILC) is an aggressive variant of invasive lobular carcinoma (ILC). Its in situ counterpart, pleomorphic lobular carcinoma in situ (PLCIS) is a recently described entity. Morphologically it has the typical architectural pattern of LCIS, but the neoplastic cells resemble intermediate grade DCIS. Molecular signatures that distinguish PLCIS from DCIS and LCIS would provide additional tools to aid in the histopathologic classification of PLCIS as...

Raju, Usha; Mei, Lu; Seema, Sethi; Hina, Qureshi; Wolman, Sandra R.; Worsham, Maria J.

2006-01-01

203

In Situ Flash Pyrolysis of Straw  

OpenAIRE

In-Situ Flash Pyrolysis of Straw Ph.D. dissertation by Niels Bech Submitted: April 2007. Supervisors: Professor Kim Dam-Johansen, Associate Professor Peter Arendt Jensen Erfaringerne med forbrænding af halm opnået gennem et årti har vist, at en proces der kan koncentrere energien på marken, fjerne aske og reducere logistikomkostningerne ville gøre denne alternative energikilde betydelig mere attraktiv. Disse mål kan nås med in situ flash pyrolyse, hvor halm bliver omdanne...

Bech, Niels; Dam-johansen, Kim; Jensen, Peter Arendt

2008-01-01

204

DOE In Situ Remediation Integrated Program. In situ manipulation technologies subprogram plan  

Energy Technology Data Exchange (ETDEWEB)

The In Situ Remediation Integrated Program (ISRP) supports and manages a balanced portfolio of applied research and development activities in support of DOE environmental restoration and waste management needs. ISRP technologies are being developed in four areas: containment, chemical and physical treatment, in situ bioremediation, and in situ manipulation (including electrokinetics). the focus of containment is to provide mechanisms to stop contaminant migration through the subsurface. In situ bioremediation and chemical and physical treatment both aim to destroy or eliminate contaminants in groundwater and soils. In situ manipulation (ISM) provides mechanisms to access contaminants or introduce treatment agents into the soil, and includes other technologies necessary to support the implementation of ISR methods. Descriptions of each major program area are provided to set the technical context of the ISM subprogram. Typical ISM needs for major areas of in situ remediation research and development are identified.

Yow, J.L. Jr.

1993-12-22

205

In situ detection of anaerobic alkane metabolites in subsurface environments  

Directory of Open Access Journals (Sweden)

Full Text Available Alkanes comprise a substantial fraction of crude oil and refined fuels. As such, they are prevalent within deep subsurface fossil fuel deposits and in shallow subsurface environments such as aquifers that are contaminated with hydrocarbons. These environments are typically anaerobic, and host diverse microbial communities that can potentially use alkanes as substrates. Anaerobic alkane biodegradation has been reported to occur under nitrate-reducing, sulfate-reducing, and methanogenic conditions. Elucidating the pathways of anaerobic alkane metabolism has been of interest in order to understand how microbes can be used to remediate contaminated sites. Alkane activation primarily occurs by addition to fumarate, yielding alkylsuccinates, unique anaerobic metabolites that can be used to indicate in situ anaerobic alkane metabolism. These metabolites have been detected in hydrocarbon-contaminated shallow aquifers, offering strong evidence for intrinsic anaerobic bioremediation. Recently, studies have also revealed that alkylsuccinates are present in oil and coal seam production waters, indicating that anaerobic microbial communities can utilize alkanes in these deeper subsurface environments. In many crude oil reservoirs, the in situ anaerobic metabolism of hydrocarbons such as alkanes may be contibuting to modern-day detrimental effects such as oilfield souring, or may lead to more benefical technologies such as enhanced energy recovery from mature oilfields. In this review, we briefly describe the key metabolic pathways for anaerobic alkane (including n-alkanes, isoalkanes, and cyclic alkanes metabolism and highlight several field reports wherein alkylsuccinates have provided evidence for anaerobic in situ alkane metabolism in shallow and deep subsurface environments.

LisaGieg

2013-06-01

206

In situ detection of anaerobic alkane metabolites in subsurface environments.  

Science.gov (United States)

Alkanes comprise a substantial fraction of crude oil and refined fuels. As such, they are prevalent within deep subsurface fossil fuel deposits and in shallow subsurface environments such as aquifers that are contaminated with hydrocarbons. These environments are typically anaerobic, and host diverse microbial communities that can potentially use alkanes as substrates. Anaerobic alkane biodegradation has been reported to occur under nitrate-reducing, sulfate-reducing, and methanogenic conditions. Elucidating the pathways of anaerobic alkane metabolism has been of interest in order to understand how microbes can be used to remediate contaminated sites. Alkane activation primarily occurs by addition to fumarate, yielding alkylsuccinates, unique anaerobic metabolites that can be used to indicate in situ anaerobic alkane metabolism. These metabolites have been detected in hydrocarbon-contaminated shallow aquifers, offering strong evidence for intrinsic anaerobic bioremediation. Recently, studies have also revealed that alkylsuccinates are present in oil and coal seam production waters, indicating that anaerobic microbial communities can utilize alkanes in these deeper subsurface environments. In many crude oil reservoirs, the in situ anaerobic metabolism of hydrocarbons such as alkanes may be contributing to modern-day detrimental effects such as oilfield souring, or may lead to more beneficial technologies such as enhanced energy recovery from mature oilfields. In this review, we briefly describe the key metabolic pathways for anaerobic alkane (including n-alkanes, isoalkanes, and cyclic alkanes) metabolism and highlight several field reports wherein alkylsuccinates have provided evidence for anaerobic in situ alkane metabolism in shallow and deep subsurface environments. PMID:23761789

Agrawal, Akhil; Gieg, Lisa M

2013-01-01

207

Aquifer restoration at uranium in situ leach sites  

International Nuclear Information System (INIS)

In situ mining of uranium involves injection of a leaching solution (lixiviant) into an ore-bearing aquifer. Frequently, the ground water in the mined aquifer is a domestic or livestock water supply. As the lixiviant migrates through the ore body, uranium and various associated elements such as arsenic, selenium, molybdenum, vanadium and radium-226 are mobilized in the ground water. Aquifer restoration after in situ mining is not fully understood. Several methods have been developed to restore mined aquifers to pre-mining (baseline) quality. Commonly used methods include ground water sweeping, clean water injection, and treatment by ion exchange and reverse osmosis technologies. Ammonium carbonate lixiviant was used at one RandD in situ mine. Attempts were made to restore the aquifer using a variety of methods. Efforts were successful in reducing concentrations of the majority of contaminants to baseline levels. Concentrations of certain parameters, however, remained at levels above baseline six months after restoration ceased. Relatively large quantities of ground water were processed in the restoration attempt considering the small size of the project (1.25 acre). More thorough characterization of the hydrogeology of the site may have enhanced the effectiveness of restoration and reduced potential environmental impacts associated with the project. This paper presents some of the findings of a research project conducted by the Mineral Resources Waste Management Team e Mineral Resources Waste Management Team at the University of Idaho in Moscow, Idaho. Views contained herein do not reflect U.S. Nuclear Regulatory Commission policy

208

In Situ Measurement of Tritium Permeation Through Stainless Steel  

Energy Technology Data Exchange (ETDEWEB)

The TMIST-2 irradiation experiment was conducted in the Advanced Test Reactor at Idaho National Laboratory to evaluate tritium permeation through Type 316 stainless steel (316 SS). The interior of a 316 SS seamless tube specimen was exposed to a 4He carrier gas mixed with a specified quantity of tritium (T2) to yield partial pressures of 0.1, 5, and 50 Pa at 292° and 330°C. In-situ tritium permeation measurements were made by passing a He-Ne sweep gas over the outer surface of the specimen to carry the permeated tritium to a bubbler column for liquid scintillation counting. An irradiation enhancement factor (IEF) was determined by comparing in-situ permeation data with a correlation for ex-reactor hydrogen permeation through austenitic stainless steel developed from literature data and reported by Le Claire. Nominal values for the IEF ranged between 3 and 5 for 316 SS. In-situ permeation data were also used to derive an in-reactor permeation correlation as a function of temperature and pressure. In addition, the triton recoil contribution to tritium permeation, which results from the transmutation of 3He to T, was also evaluated by introducing a 4He carrier gas mixed with 3He at a partial pressure of 1013 Pa at 330°C. Less than 3% of the tritium resulting from 3He transmutation contributed to tritium permeation.

Luscher, Walter G.; Senor, David J.; Clayton, Kevin; Longhurst, Glen

2013-06-01

209

IN-SITU MEASUREMENT OF TRITIUM PERMEATION THROUGH STAINLESS STEEL  

Energy Technology Data Exchange (ETDEWEB)

The TMIST-2 irradiation experiment was conducted in the Advanced Test Reactor at Idaho National Laboratory to evaluate tritium permeation through Type 316 stainless steel (316 SS). The interior of a 316 SS seamless tube specimen was exposed to a 4He carrier gas mixed with a specified quantity of tritium (T2) to yield partial pressures of 0.1, 5, and 50 Pa at 292° and 330°C. In-situ tritium permeation measurements were made by passing a He-Ne sweep gas over the outer surface of the specimen to carry the permeated tritium to a bubbler column for liquid scintillation counting. An irradiation enhancement factor (IEF) was determined by comparing in-situ permeation data with a correlation for ex-reactor hydrogen permeation through austenitic stainless steel developed from literature data and reported by Le Claire. Nominal values for the IEF ranged between 3 and 5 for 316 SS. In-situ permeation data were also used to derive an in-reactor permeation correlation as a function of temperature and pressure. In addition, the triton recoil contribution to tritium permeation, which results from the transmutation of 3He to T, was also evaluated by introducing a 4He carrier gas mixed with 3He at a partial pressure of 1013 Pa at 330°C. Less than 3% of the tritium resulting from 3He transmutation contributed to tritium permeation.

Luscher, Walter G.; Senor, David J.; Clayton, Kevin; Longhurst, Glen R.

2013-06-01

210

Effect of laser in situ keratomileusis on accommodation.  

Science.gov (United States)

The accommodative function before and after laser in situ keratomileusis (LASIK) was observed, and the effect of LASIk on accommodation was investigated. In a prospective clinical trial, 48 myopic patients (96 eyes) subject to bilateral LASIK in Refractive Surgery Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (China) from March 2006 to June 2006 were selected and studied. Refractions, accommodative range, amplitude of accommodative response and high frequency component (HFC) of accommodative microfluctuations were measured with NEDIK-730A before and one week and 30 days after operation. Dominant and non-dominant eyes were determined by hole-in-card method. It was found that all of the operative eyes showed an uncorrected visual acuity of 0.8 or better one week postoperatively, and 1.0 or better 30 days postoperatively. Compared with those preoperatively, accommodative range and HFC had no significant difference at first week and 30th day after operation in both dominant eyes and non-dominant eyes (P>0.05), but there was a significant difference in the amplitude of accommodative response/accommodative stimulus ratio (A/S) after operation (Paccommodation between one week and 30 days postoperation. No ocular dominance's change was noted. There was no significant difference in accommodative function between dominant eyes and non-dominant eyes. It was suggested that LASIK produced no significant effect on accommodation. PMID:18846347

Liu, Lei; Yuan, Jing; Li, Jing; Li, Xinyu; Wang, Yulong

2008-10-01

211

Demonstration testing and evaluation of in situ soil heating  

International Nuclear Information System (INIS)

A Treatability Study planned for the demonstration of the in situ electromagnetic (EM) heating process to remove organic solvents is described in this Work Plan. The treatability study will be conducted by heating subsurface vadose-zone soils in an organic plume adjacent to the Classified Burial Ground K-1070-D located at K-25 Site, Oak Ridge. The test is scheduled to start during the fourth quarter of FY94 and will be completed during the first quarter of FY95. The EM heating process for soil decontamination is based on volumetric heating technologies developed during the '70s for the recovery of fuels from shale and tar sands by IIT Research Institute (IITRI) under a co-operative program with the US Department of Energy (DOE). Additional modifications of the technology developed during the mid '80s are currently used for the production of heavy oil and waste treatment. Over the last nine years, a number of Government agencies (EPA, Army, AF, and DOE) and industries sponsored further development and testing of the in situ heating and soil decontamination process for the remediation of soils containing hazardous organic contaminants. In this process the soil is heated in situ using electrical energy. The contaminants are removed from the soil due to enhanced vaporization, steam distillation and stripping. IITRI will demonstrate the EM Process for in situ soil decontamination at K-25 Site under the proposed treatability study. Most of the contaminants of concern are volatile organics which can be removed by heating the soil to a temperature range of 85 to 95 C. The efficiency of the treatment will be determined by comparing the concentration of contaminants in soil samples. Samples will be obtained before and after the demonstration for a measurement of the concentration of contaminants of concern

212

The effect of chemically defined medium on spontaneous calcium signaling of in situ chondrocytes during long-term culture.  

Science.gov (United States)

Chemically defined serum-free medium has been shown to better maintain the mechanical integrity of articular cartilage explants than serum-supplemented medium during long-term in vitro culture, but little is known about its effect on cellular mechanisms. We hypothesized that the chemically defined culture medium could regulate the spontaneous calcium signaling of in situ chondrocytes, which may modulate the cellular metabolic activities. Bovine cartilage explants were cultured in chemically defined serum-free or serum-supplemented medium for four weeks. The spontaneous intracellular calcium ([Ca(2+)]i) signaling of in situ chondrocytes was longitudinally measured together along with the biomechanical properties of the explants. The spontaneous [Ca(2+)]i oscillations in chondrocytes were enhanced at the initial exposure of serum-supplemented medium, but were significantly dampened afterwards. In contrast, cartilage explants in chemically defined medium preserved the level of calcium signaling, and showed more responsive cells with higher and more frequent [Ca(2+)]i peaks throughout the four week culture in comparison to those in serum medium. Regardless of the culture medium that the explants were exposed, a positive correlation was detected between the [Ca(2+)]i responsive rate and the stiffness of cartilage (Spearman?s rank correlation coefficient=0.762). A stable pattern of [Ca(2+)]i peaks was revealed for each chondrocyte, i.e., the spatiotemporal features of [Ca(2+)]i peaks from a cell were highly consistent during the observation period (15min). This study showed that the beneficial effect of chemically defined culture of cartilage explants is associated with the spontaneous [Ca(2+)]i signaling of chondrocytes in cartilage. PMID:25700610

Zhou, Yilu; Park, Miri; Cheung, Enoch; Wang, Liyun; Lu, X Lucas

2015-04-13

213

In situ bioremediation of trichloroethylene-contaminated water by a resting-cell methanotrophic microbial filter  

International Nuclear Information System (INIS)

The Lawrence Livermore National Laboratory is testing and developing an in situ microbial filter technology for remediating migrating subsurface plumes contaminated with low concentrations of trichloroethylene (TCE). Their current focus is the establishment of a replenishable bioactive zone (catalytic filter) along expanding plume boundaries by the Injection of a representative methanotrophic bacterium, Methylosinus trichosporium OB3b. We have successfully demonstrated this microbial filter strategy using emplaced, attached resting cells (no methane additions) in a 1.1-m flow-through test bed loaded with water-saturated sand. Two separate 24 h pulses of TCE (109 ppb and 85 ppb), one week apart, were pumped through the system at a flow velocity of 1.5 cm/h; no TCE (<0.5 ppb) was detected on the downstream side of the microbial filter. Subsequent excavation of the wet sand confirmed the existence of a TCE-bioactive zone 19 days after it had been created. An enhanced longevity of the cellular, soluble-form methane monooxygenase produced by this methanotroph Is a result of our laboratory bioreactor culturing conditions. Additional experiments with cells in sealed vials and emplaced in the 1.1-m test bed yielded a high resting-cell finite TCE biotransformation capacity of ? 0.25 mg per mg of bacteria; this is suitable for a planned sand-filled trench field demonstration at a Lawrence Livermore National Laboratory site

214

MENDING THE IN SITU MANIPULATION BARRIER  

Energy Technology Data Exchange (ETDEWEB)

In early 2004, the U.S. Department of Energy (DOE) Richland and Fluor Hanford requested technical assistance from the DOE Headquarters EM-23 Technical Assistance Program to provide a team of technical experts to develop recommendations for mending the In Situ Redox Manipulation (ISRM) Barrier in the 100-D Area of the Hanford Site in Washington State. To accommodate this request, EM-23 provided support to convene a group of technical experts from industry, a national laboratory, and a DOE site to participate in a 2 1/2-day workshop with the objective of identifying and recommending options to enhance the performance of the 100-D Area reactive barrier and of a planned extension to the northeast. This report provides written documentation of the team's findings and recommendations. In 1995, a plume of dissolved hexavalent chromium [Cr(VI)], which resulted from operation of the D/DR Reactors at the Hanford site, was discovered along the Columbia River shoreline and in the 100-D Area. Between 1999 and 2003, a reactive barrier using the In Situ Redox Manipulation (ISRM) technology, was installed a distance of 680 meters along the river to reduce the Cr(VI) in the groundwater. The ISRM technology creates a treatment zone within the aquifer by injection of sodium dithionite, a strong reducing agent that scavenges dissolved oxygen (DO) from the aquifer and reduces ferric iron [Fe(III)], related metals, and oxy-ions. The reduction of Fe(III) to ferrous [Fe(II)] iron provides the primary reduction capacity to reduce Cr(VI) to the +3 state, which is less mobile and less toxic. Bench-scale and field-scale treatability tests were initially conducted to demonstrate proof-of principle and to provide data for estimation of barrier longevity. These calculations estimated barrier longevity in excess of twenty years. However, several years after initial and secondary treatment, groundwater in a number of wells has been found to contain elevated chromium (Cr) concentrations, indicating some loss of reductive capacity within the aquifer. The Technical Assistance Team (TAT) was requested to perform the following activities: (1) evaluate the most probable condition(s) that has led to the presence of Cr(VI) in 12 different barrier wells (i.e. premature loss of reductive capacity), (2) recommend methods for determining the cause of the problem, (3) recommend methods for evaluating the magnitude of the problem, (4) recommend practicable method(s) for mending the barrier that involves a long-term solution, and (5) recommend methods for extending the barrier to the northeast (e.g., changing injection procedure, changing or augmenting the injected material). Since the March 2004 workshop, a decision has been made to place a hold on the barrier extension until more is known about the cause of the problem. However, the report complies with the original request for information on all of the above activities, but focuses on determining the cause of the problem and mending of the existing barrier.

PETERSEN, S.W.

2006-02-06

215

in situ Calcite Precipitation for Contaminant Immobilization  

Energy Technology Data Exchange (ETDEWEB)

in situ Calcite Precipitation for Contaminant Immobilization Yoshiko Fujita (Yoshiko.fujita@inl.gov) (Idaho National Laboratory, Idaho Falls, Idaho, USA) Robert W. Smith (University of Idaho-Idaho Falls, Idaho Falls, Idaho, USA) Subsurface radionuclide and trace metal contaminants throughout the U.S. Department of Energy (DOE) complex pose one of DOE’s greatest challenges for long-term stewardship. One promising stabilization mechanism for divalent trace ions, such as the short-lived radionuclide strontium-90, is co-precipitation in calcite. Calcite, a common mineral in the arid western U.S., can form solid solutions with trace metals. The rate of trace metal incorporation is susceptible to manipulation using either abiotic or biotic means. We have previously demonstrated that increasing the calcite precipitation rate by stimulating the activity of urea hydrolyzing microorganisms can result in significantly enhanced Sr uptake. Urea hydrolysis causes the acceleration of calcium carbonate precipitation (and trace metal co-precipitation) by increasing pH and alkalinity, and also by liberating the reactive cations from the aquifer matrix via exchange reactions involving the ammonium ion derived from urea: H2NCONH2 + 3H2O ? 2NH4+ + HCO3- + OH- urea hydrolysis >X:2Ca + 2NH4+ ? 2>X:NH4 + Ca2+ ion exchange Ca2+ + HCO3- + OH- ? CaCO3(s) + H2O calcite precipitation where >X: is a cation exchange site on the aquifer matrix. This contaminant immobilization approach has several attractive features. Urea hydrolysis is catalyzed by the urease enzyme, which is produced by many indigenous subsurface microorganisms. Addition of foreign microbes is unnecessary. In turn the involvement of the native microbes and the consequent in situ generation of reactive components in the aqueous phase (e.g., carbonate and Ca or Sr) can allow dissemination of the reaction over a larger volume and/or farther away from an amendment injection point, as compared to direct addition of the reactants at a well (which can lead to clogging). A final particularly attractive characteristic of this approach is its long-term sustainability; the remediation scheme is geared toward environments that are already saturated with respect to calcite, and in such systems the bulk of any newly precipitated calcite will remain stable once engineered manipulations cease. This means that the co-precipitated contaminants will be effectively sequestered over the long term. We are currently conducting integrated field, laboratory, and computational research to evaluate a) the relationships between urea hydrolysis rate, calcite precipitation rate, and trace metal partitioning under environmentally relevant conditions; and b) the coupling between flow/flux manipulations and calcite precipitate distribution and metal uptake. We are also assessing the application of geophysical and molecular biological tools to monitor the relevant chemical and physical processes. The primary emphasis is on field-scale processes, with the laboratory and modeling activities designed specifically to support the field studies. Field experiments are being conducted in perched water (vadose zone) at the Vadose Zone Research Park (VZRP) at the Idaho National Laboratory; the VZRP provides an uncontaminated setting that is an analog of the 90Sr-contaminated vadose zone at the Idaho Nuclear Technology and Engineering Center. A summary of results to date will be presented.

Yoshiko Fujita; Robert W. Smith

2009-08-01

216

In situ forming polymeric drug delivery systems.  

Science.gov (United States)

In situ forming polymeric formulations are drug delivery systems that are in sol form before administration in the body, but once administered, undergo gelation in situ, to form a gel. The formation of gels depends on factors like temperature modulation, pH change, presence of ions and ultra violet irradiation, from which the drug gets released in a sustained and controlled manner. Various polymers that are used for the formulation of in situ gels include gellan gum, alginic acid, xyloglucan, pectin, chitosan, poly(DL-lactic acid), poly(DL-lactide-co-glycolide) and poly-caprolactone. The choice of solvents like water, dimethylsulphoxide, N-methyl pyrrolidone, triacetin and 2-pyrrolidone for these formulations depends on the solubility of polymer used. Mainly in situ gels are administered by oral, ocular, rectal, vaginal, injectable and intraperitoneal routes. The in situ gel forming polymeric formulations offer several advantages like sustained and prolonged action in comparison to conventional drug delivery systems. The article presents a detailed review of these types of polymeric systems, their evaluation, advancements and their commercial formulations. From a manufacturing point of view, the production of such devices is less complex and thus lowers the investment and manufacturing cost. PMID:20490289

Madan, M; Bajaj, A; Lewis, S; Udupa, N; Baig, J A

2009-05-01

217

ADVANTAGES/DISADVANTAGES FOR ISCO METHODS IN-SITU FENTON OXIDATION IN-SITU PERMANGANATE OXIDATION  

Science.gov (United States)

The advantages and disadvantages of in-situ Fenton oxidation and in-situ permanganate oxidation will be presented. This presentation will provide a brief overview of each technology and a detailed analysis of the advantages and disadvantages of each technology. Included in the ...

218

In Situ Imaging of Atomic Quantum Gases  

Science.gov (United States)

One exciting progress in recent cold atom experiments is the development of high resolution, in situ imaging techniques for atomic quantum gases.1-3 These new powerful tools provide detailed information on the distribution of atoms in a trap with resolution approaching the level of single atom and even single lattice site, and complement the welldeveloped time-of-flight method that probes the system in momentum space. In a condensed matter analogy, this technique is equivalent to locating electrons of a material in a snap shot. In situ imaging has offered a new powerful tool to study atomic gases and inspired many new research directions and ideas. In this chapter, we will describe the experimental setup of in situ absorption imaging, observables that can be extracted from the images, and new physics that can be explored with this technique.

Hung, Chen-Lung; Chin, Cheng

2015-09-01

219

In situ macromolecular crystallography using microbeams.  

Science.gov (United States)

Despite significant progress in high-throughput methods in macromolecular crystallography, the production of diffraction-quality crystals remains a major bottleneck. By recording diffraction in situ from crystals in their crystallization plates at room temperature, a number of problems associated with crystal handling and cryoprotection can be side-stepped. Using a dedicated goniometer installed on the microfocus macromolecular crystallography beamline I24 at Diamond Light Source, crystals have been studied in situ with an intense and flexible microfocus beam, allowing weakly diffracting samples to be assessed without a manual crystal-handling step but with good signal to noise, despite the background scatter from the plate. A number of case studies are reported: the structure solution of bovine enterovirus 2, crystallization screening of membrane proteins and complexes, and structure solution from crystallization hits produced via a high-throughput pipeline. These demonstrate the potential for in situ data collection and structure solution with microbeams. PMID:22525757

Axford, Danny; Owen, Robin L; Aishima, Jun; Foadi, James; Morgan, Ann W; Robinson, James I; Nettleship, Joanne E; Owens, Raymond J; Moraes, Isabel; Fry, Elizabeth E; Grimes, Jonathan M; Harlos, Karl; Kotecha, Abhay; Ren, Jingshan; Sutton, Geoff; Walter, Thomas S; Stuart, David I; Evans, Gwyndaf

2012-05-01

220

Oil companies push in-situ recovery  

International Nuclear Information System (INIS)

Possibly, a third Athabaska tar-sand plant using surface mining will be built in the 1980's, but future development beyond that point will probably depend on in-situ recovery. The discussion of in-situ recovery focusses on the effect it will have on the Canadian chemical industry, for example, the market for sodium hydroxide. To obtain the highest yields of oil from bitumen, an external source of hydrogen is necessary; for example Syncrude imports natural gas to make hydrogen for desulphurization. Gasification of coal is a possible source of hydrogen. Research on hydrocracking is progressing. Use of a prototype CANDU OCR reactor to raise the hot steam necessary for in-situ recovery has been suggested. Venezuela is interested in Canadian upgrading technology. (N.D.H.)

221

In situ simulation: Taking reported critical incidents and adverse events back to the clinic  

DEFF Research Database (Denmark)

Introduction In situ simulation offers a novel approach to training in the healthcare setting. It models clinical processes in a real clinical environment and provides the opportunity to correct errors and adjust team interactions without endangering patients. Training in the simulation laboratory does not tap into situational resources, e.g. individual, team, and organisational characteristics such as routines, personal relations, distributed skill-levels etc. Therefore, it fails to fully mimic real clinical team processes. Alternatively, in situ simulation offers a unique opportunity to explore and improve team processes in the clinical environment. Though research on in situ simulation in healthcare is in its infancy, literature is abundant on patient safety, medical simulation, team training and human factors1. Patient safety reporting systems that identify risks to patients can improve patient safety if coupled with training and organisational support2. Insight into the nature of reported critical incidents and adverse events can be used in writing in situ simulation scenarios and thus lead to interventions that enhance patient safety. The patient safety literature emphasises well-developed non-technical skills in preventing medical errors3. Furthermore, critical incidents and adverse events reporting systems comprise a knowledgebase to gain in-depth insights into patient safety issues. This study explores the use of critical incidents and adverse events reports to inform in situ simulation to improve patient safety. Design and purpose The study uses a case study design of in situ simulation training tailored to two emergency departments in the Central Denmark Region. We aim to: - Develop a model that integrates critical incidents and adverse events, a contextual needs analysis and short-term observations in the design of in situ simulation. - Deliver and evaluate the usability of in situ simulation training to interprofessional emergency teams. Methods The project has a triple strategy: 1) Patient safety data analysis and literature review, 2) Video observational study on interprofessional emergency teams, and 3) In situ simulation intervention study with evaluation of training. Reported critical incidents and adverse events will be collected from the Danish Patient Safety Database in the Central Denmark Region and analysed using the qualitative software programme NVivo 10 for content analysis4 and thematic analysis5. Medical experts and simulation faculty will design scenarios for in situ simulation training based on the analysis. Short-term observations using time logs will be performed along with interviews with key informants at the departments. Video data will be collected and used for debriefing6 focusing on team communication and team adaptation7 after in situ simulation training. Perspective and relevance First, this study might help taking reported critical incidents and adverse events back to the clinic. Second, reported critical incidents and adverse events coupled with a contextual needs analysis and short-term observations might aid in scenario design for in situ simulation. This will shed light on how to develop specific learning goals for in situ simulation based on clinical challenges in acute healthcare settings. Third, in situ simulation offers a unique way to study team interactions associated with effective interprofessional teamwork. In particular, team non-technical skills and team adaptation, and their interplay will be scrutinised. In summary, this study offers in situ simulation faculty with a model for integrating reported critical incidents and adverse events with contextual needs analysis and short-term observations. This study generates system knowledge that might lead to changes on the individual, team, and organisational level, and thus enhancing patient safety. References (1) Rosen MA, Hunt EA, Pronovost PJ, Federowicz MA, Weaver SJ. In situ simulation in continuing medical education for the health care professions: A systematic review. J Contin Educ Health Prof 2012; 32(4):243-254.

Juul, Jonas; Paltved, Charlotte

222

In situ Investigation of the Silver-CTAB system  

International Nuclear Information System (INIS)

Recent research has shown that biologically inspired approaches to materials synthesis and self-assembly, hold promise of unprecedented atomic level control of structure and interfaces. In particular, the use of organic molecules to control the production of inorganic technological materials has the potential for controlling grain structure to enhance material strength; controlling facet expression for enhanced catalytic activity; and controlling the shape of nanostructured materials to optimize optical, electrical and magnetic properties. In this work, we use organic molecules to modify silver crystal shapes towards understanding the metal-organic interactions that lead to nanoparticle shape control. Using in situ electrochemical AFM (EC-AFM) as an in situ probe, we study the influence of a cationic surfactant cetyltrimethylamminobromide (CTAB) on Ag growth during electrochemical deposition on Ag(100). The results show that the organic surfactant promotes the growth of steps on the (100) surface and changes the surface evolution from island nucleation to step flow growth. Overall, this leads to a smoother, faster growing (100) surface, which may promote plate-formation

223

In situ Investigation of the Silver-CTAB system  

Energy Technology Data Exchange (ETDEWEB)

Recent research has shown that biologically inspired approaches to materials synthesis and self-assembly, hold promise of unprecedented atomic level control of structure and interfaces. In particular, the use of organic molecules to control the production of inorganic technological materials has the potential for controlling grain structure to enhance material strength; controlling facet expression for enhanced catalytic activity; and controlling the shape of nanostructured materials to optimize optical, electrical and magnetic properties. In this work, we use organic molecules to modify silver crystal shapes towards understanding the metal-organic interactions that lead to nanoparticle shape control. Using in situ electrochemical AFM (EC-AFM) as an in situ probe, we study the influence of a cationic surfactant cetyltrimethylamminobromide (CTAB) on Ag growth during electrochemical deposition on Ag(100). The results show that the organic surfactant promotes the growth of steps on the (100) surface and changes the surface evolution from island nucleation to step flow growth. Overall, this leads to a smoother, faster growing (100) surface, which may promote plate-formation.

Gray, J J; Orme, C A; Du, D; Srolovitz, D

2007-04-16

224

In-situ vitrification of waste materials  

Science.gov (United States)

A method for the in-situ vitrification of waste materials in a disposable can that includes an inner container and an outer container is disclosed. The method includes the steps of adding frit and waste materials to the inner container, removing any excess water, heating the inner container such that the frit and waste materials melt and vitrify after cooling, while maintaining the outer container at a significantly lower temperature than the inner container. The disposable can is then cooled to ambient temperatures and stored. A device for the in-situ vitrification of waste material in a disposable can is also disclosed.

Powell, James R. (Shoreham, NY); Reich, Morris (Kew Gardens Hills, NY); Barletta, Robert (Wading River, NY)

1997-11-14

225

In-situ observation of ettringite crystals  

Science.gov (United States)

In-situ observation of growing ettringite crystals in solution has been carried out and the morphology change of ettringite has been investigated under various conditions. In particular, the acceleration behavior of ettringite growth in the presence of calcite, the cause of which is not yet understood, is examined. Spherulite with calcite in its core is formed first followed by the generation of acicular crystals. Compared with the in-situ observation result of crystal growth in a solution with no calcite, the effect of added calcite can be explained as a decrease in the activation energy of nucleation for ettringite around calcite.

Komatsu, Ryuichi; Mizukoshi, Norihiro; Makida, Koji; Tsukamoto, Katsuo

2009-01-01

226

In situ-investigations in salt formations  

International Nuclear Information System (INIS)

The paper reports the in situ-investigations of the disposal of radioactive wastes in salt formations by the Federal Republic of Germany and the Netherlands, as part of the second Commission of European Communities programme. The emphasis of the German programme lay with the disposal of high-level wastes, including the temperature test field 5. The Dutch in situ-test programme concentrated on convergence and pressure measurements at normal and elevated temperatures in a 300m deep borehole. (U.K.)

227

In situ soil remediation using electrokinetics  

International Nuclear Information System (INIS)

Electrokinetics is emerging as a promising technology for in situ soil remediation. This technique is especially attractive for Superfund sites and government operations which contain large volumes of contaminated soil. The approach uses an applied electric field to induce transport of both radioactive and hazardous waste ions in soil. The transport mechanisms include electroosmosis, electromigration, and electrophoresis. The feasibility of using electrokinetics to move radioactive 137Cs and 60Co at the Hanford Site in Richland, Washington, is discussed. A closed cell is used to provide in situ measurements of 137Cs and 60Co movement in Hanford soil. Preliminary results of ionic movement, along with the corresponding current response, are presented

228

Osteogenic efficiency of in situ gelling poloxamine systems with and without bone morphogenetic protein-2  

Directory of Open Access Journals (Sweden)

Full Text Available In situ gelling solutions for minimally invasive local application of bone growth factors are attracting increasing attention as efficient and patient-friendly alternative to bone grafts and solid scaffolds for repairing bone defects. Poloxamines, i.e., X-shaped poly(ethylene oxide-poly(propylene oxide block copolymers with an ethylenediamine core (Tetronic®, were evaluated both as an active osteogenic component and as a vehicle for rhBMP-2 injectable implants. After cytotoxicity screening of various poloxamine varieties, Tetronic 908, 1107, 1301 and 1307 solutions were chosen as the most cytocompatible and their sol-to-gel transitions were rheologically characterized. Viscoelastic gels, formed at 37 ºC, sustained protein release under physiological-like conditions. Formulations of rhBMP-2 led to differentiation of mesenchymal stem cells to osteoblasts, quantified as alkaline phosphatase activity with a maximum at day 7, and to mineralized nodules. Interestingly, poloxamine solely gels led to an initial proliferation of the mesenchymal stem cells (first week, followed by differentiation to osteoblasts (second to third week. Histochemical analysis revealed that Tetronic 908 is only osteoinductive; Tetronic 1107 is mostly osteoinductive, although its use leads to a minor differentiation to adipocytes; Tetronic 1307, solely or loaded with rhBMP-2, causes differentiation of both osteoblasts and adipocytes. Enhanced expression levels of CBFA-1 and collagen type I were observed for Tetronic 908, 1107 and 1307, both solely and combined with rhBMP-2. The intrinsic osteogenic activity of poloxamines (not observed for Pluronic F127 offers novel perspectives for bone regeneration using minimally invasive procedures (i.e., injectable scaffolds and overcoming the safety and the cost/effectiveness concerns associated with large scale clinical use of recombinant growth factors.

A Rey-Rico

2011-04-01

229

AEROCLIPPER - a new approach to in situ measurements  

Science.gov (United States)

The Balloon Division in CNES is currently developing an autonomous vehicle called "AEROCLIPPER" which provides simultaneous ocean-surface and air measurements, over large distances, notably in zones where classical systems are rather scarce such as the Pacific Ocean, the Southern Seas, the South Atlantic and the Indian Ocean. A test campaign to validate the AEROCLIPPER concept took place from the island of Madeira (Portugal) in June 2000. The preliminary results show that the vehicle is able to cover some 6000 kilometres in distance, to endure a life duration of 2 weeks and to withstand 10 meters per second of surface wind speed. Within the VASCO project from the LMD (Laboratoire de Météorologie Dynamique), several AEROCLIPPERs will be used as a means of in situ measurements during experimental campaigns in the Indian Ocean (2002-2003).

Tockert, Christian

2001-08-01

230

Hierarchical Mesoporous In2O3 with Enhanced CO Sensing and Photocatalytic Performance: Distinct Morphologies of In(OH)3 via Self Assembly Coupled in Situ Solid-Solid Transformation.  

Science.gov (United States)

The present investigation details our interesting findings and insights into the evolution of exotic hierarchical superstructures of In(OH)3 under solvothermal conditions. Controlled variation of reaction parameters such as, reactant concentration, solvent system, crystal structure modifiers, water content along with temperature and time, yielded remarkable architectures. Diverse morphologies achieved for the first time includes (i) raspberry-like hollow spheres, (ii) nanosheet-assembled spheres, (iii) nanoparticle-assembled spheres, (iv) nanocube-assembled hollow spheres, (v) yolk-like spheres, (vi) solid spheres, (vii) nanosheets/flakes, and (viii) ultrafine nanosheets. A plausible mechanism is proposed based on the evidence gathered from a comprehensive analysis aided by electron microscopy and X-ray diffraction studies. Key stages of morphological evolution could be discerned and rationally correlated with nucleation, growth, oriented attachment, and Ostwald ripening mediated by dissolution-redeposition mechanism coupled with solid evacuation. Remarkably phase-pure bcc-In2O3 with retention of precursor morphology could be realized postcalcination at 400 °C, which underlines the advantage of this strategy. Two typical hierarchical structures (raspberry-like hollow spheres and nanoparticles assembled spheres) were investigated for their gas sensing and photocatalytic performances to highlight the advantages offered by nanostructuring. An impressive sensor response, Smax ? 7340 and 4055, respectively for the two structures along with appreciably fast response/recovery times over a wide concentration range and as low as 1 ppm exhibits the superior sensitivity toward carbon monoxide (CO). When compared to commercial In2O3, estimated rate constant indicates ?3-4 times enhancement in photocatalytic activity of the substrates toward Rhodamine-B. PMID:25798883

Shanmugasundaram, Arunkumar; Basak, Pratyay; Manorama, Sunkara V; Krishna, Binoy; Sanyadanam, Srinath

2015-04-15

231

In Vivo Osteogenic Differentiation of Human Embryoid Bodies in an Injectable in Situ-Forming Hydrogel  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, we examined the in vivo osteogenic differentiation of human embryoid bodies (hEBs by using an injectable in situ-forming hydrogel. A solution containing MPEG-b-(polycaprolactone-ran-polylactide (MCL and hEBs was easily prepared at room temperature. The MCL solution with hEBs and osteogenic factors was injected into nude mice and developed into in situ-forming hydrogels at the injection sites; these hydrogels maintained their shape even after 12 weeks in vivo, thereby indicating that the in situ-forming MCL hydrogel was a suitable scaffold for hEBs. The in vivo osteogenic differentiation was observed only in the in situ gel-forming MCL hydrogel in the presence of hEBs and osteogenic factors. In conclusion, this preliminary study suggests that hEBs and osteogenic factors embedded in an in situ-forming MCL hydrogel may provide numerous benefits as a noninvasive alternative for allogeneic tissue engineering applications.

Moon Suk Kim

2013-07-01

232

IN SITU LEAD IMMOBILIZATION BY APATITE  

Science.gov (United States)

Lead contamination is of environmental concern due to its effect on human health. he purpose of this study was to develop a technology to immobilize Pb in situ in contaminated soils and wastes using apatite. ydroxyapatite [Ca10(PO4)6(OH)2]was reacted with aqueous Pb, resinexchang...

233

Microwaves for chromogenic in situ hybridization.  

Science.gov (United States)

In situ hybridization can be employed in formalin-fixed, paraffin-embedded tissue sections (FFPT) and allows direct visualization of amplified genes and chromosomes in individual cell nuclei. Fluorescence in situ hybridization (FISH) is the most widely employed method, but the fluorescence preparations suffer from the main disadvantages of fading over time and poor visualization, the latter making it difficult to accurately separate invasive from in situ cancer cells. Chromogenic in situ hybridization (CISH) is a viable alternative to FISH in FFPT as it employs a peroxidase reaction to visualize the chromogen thus allowing the convenience of bright field microscopy and the correlation of the visualized gene amplification with cytomorphology. It is relatively less expensive and allows a permanent record, with several studies attesting to its validity. As with FISH, heat pretreatment and enzyme digestion are two critical components of the protocol. We describe a protocol for CISH in which a microwave-induced target retrieval step is introduced as a replacement for heat pretreatment. The same procedure is performed following enzyme digestion to produce consistent signals in amplified and nonamplified cells that are both larger in size and numbers when compared with those produced by the conventional protocol. PMID:21370007

Leong, Anthony S-Y; Haffajee, Zenobia

2011-01-01

234

Parametric melting studies for in situ vitrification  

International Nuclear Information System (INIS)

This report describes a series of simulation studies which examine heat conduction and electric heating during in situ vitrification (ISV). The simulation studies determine the effects of soil parameter changes on the ISV process. Changes in heat capacity, thermal conductivity and electrical conductivity are considered. The results of these studies provide a basis for experimental measurement accuracy requirements

235

Design Games for In-Situ Design  

DEFF Research Database (Denmark)

The mobile culture has spawned a host of context-based products, like location-based and tag-based applications. This presents a new challenge for the designer. There is a need of design methods that acknowledge the context and allows it to influence the design ideas. This article focuses on a design problem where an in-situ design practice may further the early design process: the case of designing a pervasive game. Pervasive games are computer games, played using the city as a game board and often using mobile phones with GPS. Some contextual design methods exist, but the author proposes an approach that calls for the designer to conceptualise and perform ideas in-situ, that is on the site, where the game is supposed to be played. The problem was to design a creativity method that incorporated in-situ design work and which generated game concepts for pervasive games. The proposed design method, called sitestorming, is based on a game using Situationistic individual exploration of the site and different types of game cards, followed by a joint evaluation of the generated ideas. A series of evaluations showed that the designers found the method enjoyable to use, that the method motivated idea generation, and that using in-situ design influenced their design ideas.

Kristiansen, Erik

2013-01-01

236

Recovering uranium from coal in situ  

International Nuclear Information System (INIS)

An underground carbonaceous deposit containing other mineral values is burned in situ. The underground hot zone is cooled down to temperature below the boiling point of a leachig solution. The leaching solution is percolated through the residial ash, with the pregnant solution recovered for separation of the mineral values in surface facilities

237

In-situ Vane Shear Test  

Science.gov (United States)

This article briefly describes the in-situ shear vane test, including images and typical results. This procedure tests the undrained shear strength of soil. Procedures of the test are not outlined, but a general overview is given. The site contains photos, charts, diagrams and instructional test to help guide the user.

238

In Situ Cleanable Alternative HEPA Filter Media  

International Nuclear Information System (INIS)

The Westinghouse Savannah River Company, located at the Savannah River Site in Aiken, South Carolina, is currently testing two types of filter media for possible deployment as in situ regenerable/cleanable High Efficiency Particulate Air (HEPA) filters. The filters are being investigated to replace conventional, disposable, glass-fiber, HEPA filters that require frequent removal, replacement, and disposal. This is not only costly and subjects site personnel to radiation exposure, but adds to the ever-growing waste disposal problem. The types of filter media being tested, as part of a National Energy Technology Laboratory procurement, are sintered nickel metal and ceramic monolith membrane. These media were subjected to a hostile environment to simulate conditions that challenge the high-level waste tank ventilation systems. The environment promoted rapid filter plugging to maximize the number of filter loading/cleaning cycles that would occur in a specified period of time. The filters were challenged using nonradioactive simulated high-level waste materials and atmospheric dust; materials that cause filter pluggage in the field. The filters are cleaned in situ using an aqueous solution. The study found that both filter media were insensitive to high humidity or moisture conditions and were easily cleaned in situ. The filters regenerated to approximately clean filter status even after numerous plugging and in situ cleaning cycles. Air Techniques International is conduces. Air Techniques International is conducting particle retention testing on the filter media at the Oak Ridge Filter Test Facility. The filters are challenged using 0.3-mm di-octyl phthalate particles. Both the ceramic and sintered media have a particle retention efficiency > 99.97%. The sintered metal and ceramic filters not only can be cleaned in situ, but also hold great potential as a long life alternative to conventional HEPA filters. The Defense Nuclear Facility Safety Board Technical Report, ''HEPA Filters Used in the Department of Energy's Hazardous Facilities'', found that conventional glass fiber HEPA filters are structurally weak and easily damaged by water or fire. The structurally stronger sintered metal and ceramic filters would reduce the potential of a catastrophic HEPA filter failure due to filter media breakthrough in the process ventilation system. An in situ regenerable system may also find application in recovering nuclear materials, such as plutonium, collected on glove box exhaust HEPA filters. This innovative approach of the in situ regenerative filtration system may be a significant improvement upon the shortfalls of conventional disposable HEPA filters

239

The determination of the in situ structure by nuclear spin contrast variation  

International Nuclear Information System (INIS)

Polarized neutron scattering from polarized nuclear spins in hydrogenous substances opens a new way of contrast variation. The enhanced contrast due to proton spin polarization was used for the in situ structure determination of tRNA of the functional complex of the E.coli ribosome

240

The determination of the in situ structure by nuclear spin contrast variation  

Energy Technology Data Exchange (ETDEWEB)

Polarized neutron scattering from polarized nuclear spins in hydrogenous substances opens a new way of contrast variation. The enhanced contrast due to proton spin polarization was used for the in situ structure determination of tRNA of the functional complex of the E.coli ribosome.

Stuhrmann, H.B. [GKSS Forschungszentrum, Geesthacht (Germany); Nierhaus, K.H. [Max-Planch-Institut fuer Molekulare Genetik, Berlin (Germany)

1994-12-31

241

In Situ Remediation Integrated Program: Technology summary  

International Nuclear Information System (INIS)

The In Situ Remediation Integrated Program (ISR IP) was instituted out of recognition that in situ remediation could fulfill three important criteria: significant cost reduction of cleanup by eliminating or minimizing excavation, transportation, and disposal of wastes; reduced health impacts on workers and the public by minimizing exposure to wastes during excavation and processing; and remediation of inaccessible sites, including: deep subsurfaces, in, under, and around buildings. Buried waste, contaminated soils and groundwater, and containerized wastes are all candidates for in situ remediation. Contaminants include radioactive wastes, volatile and non-volatile organics, heavy metals, nitrates, and explosive materials. The ISR IP intends to facilitate development of in situ remediation technologies for hazardous, radioactive, and mixed wastes in soils, groundwater, and storage tanks. Near-term focus is on containment of the wastes, with treatment receiving greater effort in future years. ISR IP is an applied research and development program broadly addressing known DOE environmental restoration needs. Analysis of a sample of 334 representative sites by the Office of Environmental Restoration has shown how many sites are amenable to in situ remediation: containment--243 sites; manipulation--244 sites; bioremediation--154 sites; and physical/chemical methods--236 sites. This needs assessment is focused on near-term restoration problems (FY93--FY99). Many other remediations will be required in the next century. The major focus of the ISR EP is on the long term development of permanent solutions to these problems. Current needs for interim actions to protect human health and the environment are also being addressed

242

In Situ Remediation Integrated Program: Technology summary  

Energy Technology Data Exchange (ETDEWEB)

The In Situ Remediation Integrated Program (ISR IP) was instituted out of recognition that in situ remediation could fulfill three important criteria: significant cost reduction of cleanup by eliminating or minimizing excavation, transportation, and disposal of wastes; reduced health impacts on workers and the public by minimizing exposure to wastes during excavation and processing; and remediation of inaccessible sites, including: deep subsurfaces, in, under, and around buildings. Buried waste, contaminated soils and groundwater, and containerized wastes are all candidates for in situ remediation. Contaminants include radioactive wastes, volatile and non-volatile organics, heavy metals, nitrates, and explosive materials. The ISR IP intends to facilitate development of in situ remediation technologies for hazardous, radioactive, and mixed wastes in soils, groundwater, and storage tanks. Near-term focus is on containment of the wastes, with treatment receiving greater effort in future years. ISR IP is an applied research and development program broadly addressing known DOE environmental restoration needs. Analysis of a sample of 334 representative sites by the Office of Environmental Restoration has shown how many sites are amenable to in situ remediation: containment--243 sites; manipulation--244 sites; bioremediation--154 sites; and physical/chemical methods--236 sites. This needs assessment is focused on near-term restoration problems (FY93--FY99). Many other remediations will be required in the next century. The major focus of the ISR EP is on the long term development of permanent solutions to these problems. Current needs for interim actions to protect human health and the environment are also being addressed.

1994-02-01

243

The production and degradation of trichloroacetic acid in soil: Results from in situ soil column experiments  

OpenAIRE

Previous work has indicated that the soil is important to understanding biogeochemical fluxes of trichloroacetic acid (TCA) in the rural environment, in forests in particular. Here, the hydrological and TCA fluxes through 22 in situ soil columns in a forest and moorland-covered catchment and an agricultural grassland field in Scotland were monitored every two weeks for several months either as controls or in TCA manipulation (artificial dosing) experiments. This was supplemented by laboratory...

Heal, M. R.; Dickey, C. A.; Heal, K. V.; Stidson, R. T.; Matucha, M.; Cape, J. N.

2010-01-01

244

Clinical effects of in situ photoimmunotherapy on late-stage melanoma patients: A preliminary study  

OpenAIRE

Metastatic melanoma is a skin cancer with poor prognosis. In situ photoimmunotherapy (ISPI) is a promising modality for the treatment of metastatic melanoma that combines local, selective photothermal therapy with immunological stimulation. A preliminary clinical study was conducted to evaluate the safety and therapeutic effects of ISPI for latestage melanoma patients using imiquimod as the immune modifier. Eleven patients received ISPI in one or multiple 6-week treatment cycles applied to a ...

Li, Xiaosong; Naylor, Mark F.; Le, Henry; Nordquist, Robert E.; Teague, T. Kent; Howard, C. Anthony; Murray, Cynthia; Chen, Wei R.

2010-01-01

245

Synthesis and Characterization of Encapsulated Nanosilica Particles with an Acrylic Copolymer by in Situ Emulsion Polymerization Using Thermoresponsive Nonionic Surfactant  

OpenAIRE

Nanocomposites of encapsulated silica nanoparticles were prepared by in situ emulsion polymerization of acrylate monomers. The synthesized material showed good uniformity and dispersion of the inorganic components in the base polymer, which enhances the properties of the nanocomposite material. A nonionic surfactant with lower critical solution temperature (LCST) was used to encapsulate the silica nanoparticles in the acrylic copolymer matrix. This in situ method combined the surface modifica...

Daryoosh Vashaee; Lobat Tayebi; Babak Fathi; Elaheh Motamedi; Tannaz Pourvala; Mostafa Yazdimamaghani

2013-01-01

246

In Vivo and In Situ Evaluation of a Wireless Magnetoelastic Sensor Array for Plastic Biliary Stent Monitoring  

OpenAIRE

This paper presents the in vivo and in situ evaluation of a system that wirelessly monitors the accumulation of biliary sludge in a plastic biliary stent. The sensing element, located within the stent, is a passive array of magnetoelastic resonators that is queried by a wireless electromagnetic signal. The in vivo and in situ testing uses commercially-available plastic biliary stents, each enhanced with an array of ribbon sensors (formed from Metglas™ 2826MB). The sensor array is approximat...

Green, Scott R.; Kwon, Richard S.; Elta, Grace H.; Gianchandani, Yogesh B.

2013-01-01

247

In situ hybridization to somatic chromosomes in Drosophila.  

Science.gov (United States)

In situ hybridization was originally developed as a technique for visualizing and physically mapping specific sequences on Drosophila melanogaster polytene chromosomes. Hybridization techniques can also be used to localize sequences on smaller, diploid chromosomes, such as condensed mitotic chromosomes. Variations of the method also allow the hybridization of probes to chromosomes within intact cells and tissues, rather than to chromosomes isolated from their cellular context and flattened on slides. This article presents methods for hybridizing fluorescent probes to chromosomes in whole-mount Drosophila tissues. These methods allow the investigation of nuclear organization even at stages where chromosomes are decondensed (as in interphase) or, for other reasons, cannot be discriminated in the light microscope. Consequently, they are useful for addressing a variety of cell biological questions. In addition to enhancing our understanding of somatic chromosome organization, this experimental approach has also revealed interactions among meiotic chromosomes in Drosophila females, which spend much of meiosis in a compact ball called the karyosome. Fluorescent in situ hybridization (FISH) methods can also be used to karyotype individual nuclei using chromosome-specific markers. With appropriate fixation conditions, hybridization to chromosomal DNA can be performed in conjunction with immunostaining, allowing the colocalization of cellular or chromosomal proteins. PMID:21880819

Dernburg, Abby F

2011-09-01

248

In situ diesel fuel bioremediation: A case history  

International Nuclear Information System (INIS)

As a result of a ruptured fuel line, the study site had diesel fuel soil contamination and free product more than 2 ft (0.75 m) thick on the groundwater surface. Diesel fuel, which is composed of a high percentage of nonvolatile compounds, has proven difficult to remediate using conventional extraction remediation techniques. A number of remedial alternatives were reviewed, and the patented in situ biodegradation BioSpargeSM technology was selected for the site and performed under license by a specialty contractor. BioSpargeSM is a field-proven closed-loop (no vapor emissions) system that supplies a continuous, steady supply of oxygen, moisture, and additional heat to enhance microorganism activity. The system injects an enriched airstream beneath the groundwater surface elevation and/or within the contaminant plume and removes residual vapors from vadose zone soil within and above the contaminant plume. The technology has no air discharge, which is critical in areas where strict air discharge regulations apply. The focus of this paper is the viability of in situ biodegradation as an effective remediation alternative for reducing nonvolatile petroleum products

249

Spontaneous heterotopic pregnancy causing tubal rupture in a patient with intrauterine device in-situ  

Directory of Open Access Journals (Sweden)

Full Text Available Spontaneous heterotopic pregnancy (HP is a rare but life threatening condition. A case of 27 years old patient who admitted to our emergency gynecology clinic for acute abdominal pain is presented. The transvaginal ultrasound revealed two embryos with cardiac activity; one intrauterine (8 week and 3 day , and the other one in the left adnexa (7 week and 3 day and an intrauterine device (IUD in situ. The patient had left salpingectomy with laparotomy and after the fifth hour of operation she had spontaneous abortion of intrauterine pregnancy. We reported a case of heterotopic pregnancy and relation with IUD and a brief review of the literature.

Serpil Telci

2014-01-01

250

Shifts in the microbial population in relation to in situ caries progression.  

Science.gov (United States)

The shift in microbial diversity from young to mature plaque, related to caries activity on sound and restored surfaces, was studied using denaturing gradient gel electrophoresis. During a 20-week in situ study on caries progression 8 subjects wearing restored and unrestored dentin and enamel sections, biofilm was sampled after 1 and 20 weeks (young or mature plaque). A higher microbial diversity (mature plaque) was seen in caries-active compared to caries-free subjects. Rothia dentocariosa and Scardovia inopinata were absent from all caries-free sites, but appeared in 50% of the caries-active sites. PMID:22739571

Thomas, R Z; Zijnge, V; Ciçek, A; de Soet, J J; Harmsen, H J M; Huysmans, M C D N J M

2012-01-01

251

In situ indentation testing of elastomers  

International Nuclear Information System (INIS)

The development of the contact is crucial in indentation testing, yet only limited knowledge exists on the true contact size for compliant materials. In this investigation the contact evolution and the deformation behavior of polydimethylsiloxane was studied during indentation in situ inside a scanning electron microscope and by observation in a light microscope. Since detailed information on the true contact area and the amount of sink-in can be acquired from finite element analysis, simulations on the indentation process have been performed in order to complement the in situ testing. Comparison of results revealed that the contact areas calculated according to the standard Oliver-Pharr procedure deviated from the real contact size by approximately 10% for the elastomeric PDMS material

252

In situ remediation of uranium contaminated groundwater  

International Nuclear Information System (INIS)

In an effort to develop cost-efficient techniques for remediating uranium contaminated groundwater at DOE Uranium Mill Tailing Remedial Action (UMTRA) sites nationwide, Sandia National Laboratories (SNL) deployed a pilot scale research project at an UMTRA site in Durango, CO. Implementation included design, construction, and subsequent monitoring of an in situ passive reactive barrier to remove Uranium from the tailings pile effluent. A reactive subsurface barrier is produced by emplacing a reactant material (in this experiment - various forms of metallic iron) in the flow path of the contaminated groundwater. Conceptually the iron media reduces and/or adsorbs uranium in situ to acceptable regulatory levels. In addition, other metals such as Se, Mo, and As have been removed by the reductive/adsorptive process. The primary objective of the experiment was to eliminate the need for surface treatment of tailing pile effluent. Experimental design, and laboratory and field preliminary results are discussed with regard to other potential contaminated groundwater treatment applications

253

In situ remediation of uranium contaminated groundwater  

International Nuclear Information System (INIS)

In an effort to develop cost-efficient techniques for remediating uranium contaminated groundwater at DOE Uranium Mill Tailing Remedial Action (UMTRA) sites nationwide, Sandia National Laboratories (SNL) deployed a pilot scale research project at an UMTRA site in Durango, CO. Implementation included design, construction, and subsequent monitoring of an in situ passive reactive barrier to remove Uranium from the tailings pile effluent. A reactive subsurface barrier is produced by emplacing a reactant material (in this experiment various forms of metallic iron) in the flow path of the contaminated groundwater. Conceptually the iron media reduces and/or adsorbs uranium in situ to acceptable regulatory levels. In addition, other metals such as Se, Mo, and As have been removed by the reductive/adsorptive process. The primary objective of the experiment was to eliminate the need for surface treatment of tailing pile effluent. Experimental design, and laboratory and field results are discussed with regard to other potential contaminated groundwater treatment applications

254

BEATRIX-II: In situ tritium test  

International Nuclear Information System (INIS)

The BEATRIX-II irradiation experiment is an in-situ tritium release experiment being carried out in the Fast Flux Test Facility (FFTF) reactor to evaluate the tritium release characteristics of fusion solid breeder materials. A sophisticated tritium gas handling system has been developed to continuously monitor the tritium recovery from the specimens and facilitate tritium removal from the experiment's sweep gas flow stream. The in-situ recovery experiment accommodates two different in-reactor specimen canisters with individual gas streams and temperature monitoring/control. Ionization chambers have been specifically designed to respond to the rapid changes in the tritium release rate at the anticipated tritium concentrations. Two ceramic electrolysis cells have proved effective in reducing the moisture in the gas streams to hydrogen/tritium. A tritium getter system, capable of reducing the tritium level by a factor greater than 4000, is used to reduce the tritium in the sweep gas to a level acceptable for release

255

Inherently safe in situ uranium recovery  

Science.gov (United States)

An in situ recovery of uranium operation involves circulating reactive fluids through an underground uranium deposit. These fluids contain chemicals that dissolve the uranium ore. Uranium is recovered from the fluids after they are pumped back to the surface. Chemicals used to accomplish this include complexing agents that are organic, readily degradable, and/or have a predictable lifetime in an aquifer. Efficiency is increased through development of organic agents targeted to complexing tetravalent uranium rather than hexavalent uranium. The operation provides for in situ immobilization of some oxy-anion pollutants under oxidizing conditions as well as reducing conditions. The operation also artificially reestablishes reducing conditions on the aquifer after uranium recovery is completed. With the ability to have the impacted aquifer reliably remediated, the uranium recovery operation can be considered inherently safe.

Krumhansl, James L; Brady, Patrick V

2014-04-29

256

Enhanced biodegradation of hydrocarbons in-situ via bioventing  

International Nuclear Information System (INIS)

This case study discusses the remediation of soils beneath a former service station impacted with volatile and semi-volatile petroleum compounds. Subsurface investigation revealed hydrocarbon contamination representative of weathered gasoline and diesel fuel in a stratified soil profile consisting of sand and silts. Only unsaturated soils were contaminated with no impact to ground water. A bioventing corrective action approach was selected which included excavation of 6,100 cubic yards of impacted soils with soil mixing to add inorganic nutrients and eliminate soil heterogeneities. Soils were then returned to the excavation after forced-air ventilation lateral lines were installed at the floor of the excavation. Soil vapor concentrations of benzene, toluene, ethylbenzene, xylenes (BTEX) rapidly declined within the first three months of system operation to nondetectable levels

257

The in situ combustion pilot project in Bare field, Orinoco oil belt, Venezuela  

Energy Technology Data Exchange (ETDEWEB)

In heavy oil fields, in-situ combustion technology can be used as a means to enhance oil recovery. This process consists of burning some part of the oil present in the reservoir to produce heat that allow increased oil displacement. The aim of this study is to present an in situ combustion pilot project (ISCPP). This project will be conducted by PDVSA Intevep and its partners in the Orinoco oil belt, Venezuela, to assess the effect of in situ combustion in increasing recovery factors from heavy crude oil reservoirs. The laboratory combustion test analyses, the static and dynamic reservoir simulations, the design, construction and completion of all wells and the study, analysis and development of surface facilities are discussed. The ISCPP is expected to be running by the end of 2011.

Perozo, H.A.; Mendoza, A.J.; Teixeira, J.; Alvarez, A.; Vasquez, P. [PDVSA Intevep (Venezuela)

2011-07-01

258

In situ Raman spectroscopy for growth monitoring of vertically aligned multiwall carbon nanotubes in plasma reactor  

Science.gov (United States)

Portable and highly sensitive Raman setup was associated with a plasma-enhanced chemical vapor deposition reactor enabling in situ growth monitoring of multi-wall carbon nanotubes despite the combination of huge working distance, high growth speed and process temperature and reactive plasma condition. Near Edge X-ray absorption fine structure spectroscopy was used for ex situ sample analysis as a complementary method to in situ Raman spectroscopy. The results confirmed the fact that the "alternating" method developed here can accurately be used for in situ Raman monitoring under reactive plasma condition. The original analytic tool can be of great importance to monitor the characteristics of these nanostructured materials and readily define the ultimate conditions for targeted results.

Labbaye, T.; Canizarès, A.; Gaillard, M.; Lecas, T.; Kovacevic, E.; Boulmer-Leborgne, Ch.; Strunskus, T.; Raimboux, N.; Simon, P.; Guimbretière, G.; Ammar, M. R.

2014-11-01

259

Optimization and analysis of NF3 in situ chamber cleaning plasmas  

International Nuclear Information System (INIS)

We report on the optimization and analysis of a dilute NF3 in situ plasma-enhanced chemical vapor deposition chamber cleaning plasma for an Applied Materials P-5000 DxL chamber. Using design of experiments methodology, we identified and optimized operating conditions within the following process space: 10-15 mol % NF3 diluted with helium, 200-400 sccm NF3 flow rate, 2.5-3.5 Torr chamber pressure, and 950 W rf power. Optical emission spectroscopy and Fourier transform infrared spectroscopy were used to endpoint the cleaning processes and to quantify plasma effluent emissions, respectively. The results demonstrate that dilute NF3-based in situ chamber cleaning can be a viable alternative to perfluorocarbon-based in situ cleans with added benefits. The relationship between chamber clean time and fluorine atom density in the plasma is also investigated

260

Excursion control at in situ uranium mines  

International Nuclear Information System (INIS)

This paper summarizes excursions (uncontrolled movement of lixiviant beyond the ore zone) based on case histories of 8 in situ uranium mines (7 in Wyoming and 1 in Texas). These case histories were compiled from data provided by the US Nuclear Regulatory Commission, the Wyoming Department of Environmental Quality, and the Texas Department of Water Resources. Most of these data were provided to the above agencies by mining companies in response to regulatory requirements pertaining to licensing actions

261

Nanoindentation in situ a Transmission Electron Microscope  

OpenAIRE

The technique of Nanoindentation in situ Transmission Electron Microscope has been implemented on a Philips CM20. Indentations have been performed on Si and Sapphire (?-Al2O3) cut from wafers; Cr/Sc multilayers and Ti3SiC2 thin films. Different sample geometries and preparation methods have been evaluated. Both conventional ion and Focused Ion Beam milling were used, with different ways of protecting the sample during milling. Observations were made of bending and fracture of samples, disloc...

Johnson, Lars

2007-01-01

262

Squamous cell carcinoma in situ after irradiation  

Energy Technology Data Exchange (ETDEWEB)

We report two cases with Squamous Cell Carcinoma (SCC) in situ caused by irradiation to hand eczemas, resistant to any topical therapies. Both of our cases clinically show palmer sclerosis and flexor restriction of the fingers, compatible to chronic radiation dermatitis. Although SCC arising in chronic radiation dermatitis is usually developed ten to twenty years after irradiation, in our cases SCC were found more than forty years after irradiation. (author)

Kambara, Takeshi; Nishiyama, Takafumi; Yamada, Rie; Nagatani, Tetsuo; Nakajima, Hiroshi [Yokohama City Univ. (Japan). School of Medicine; Sugiyama, Asami

1997-12-31

263

In situ Moessbauer studies of electrochemical processes  

International Nuclear Information System (INIS)

Recent electrochemical studies involving in situ Moessbauer spectroscopy are reviewed. The principal application has been the development of new electrodes for lithium-ion batteries, where Moessbauer spectroscopy plays an important complementary role to XRD in characterizing, and usually identifying, nanocrystalline and intermediate phases of iron and tin. Other applications include the crystallography of Prussian Blue, taken using a recently developed spectrometer for acquiring multiple spectra during continuous cyclic voltammetry, valence interconversion in clay minerals and electrochemical oxygen reduction.

264

In situ health monitoring of piezoelectric sensors  

Science.gov (United States)

An in situ health monitoring apparatus may include an exciter circuit that applies a pulse to a piezoelectric transducer and a data processing system that determines the piezoelectric transducer's dynamic response to the first pulse. The dynamic response can be used to evaluate the operating range, health, and as-mounted resonance frequency of the transducer, as well as the strength of a coupling between the transducer and a structure and the health of the structure.

Jensen, Scott L. (Inventor); Drouant, George J. (Inventor)

2013-01-01

265

Robust and efficient in situ quantum control  

OpenAIRE

Precision control of quantum systems is the driving force for both quantum technology and the probing of physics at the quantum and nano-scale. We propose an implementation independent method for in situ quantum control that leverages recent advances in the direct estimation of quantum gate fidelity. Our algorithm takes account of the stochasticity of the problem and is suitable for closed-loop control and requires only a constant number of fidelity estimating experiments pe...

Ferrie, Christopher; Moussa, Osama

2014-01-01

266

In situ macromolecular crystallography using microbeams.  

OpenAIRE

Despite significant progress in high-throughput methods in macromolecular crystallography, the production of diffraction-quality crystals remains a major bottleneck. By recording diffraction in situ from crystals in their crystallization plates at room temperature, a number of problems associated with crystal handling and cryoprotection can be side-stepped. Using a dedicated goniometer installed on the microfocus macromolecular crystallography beamline I24 at Diamond Light Source, crystals ha...

Axford, D.; Owen, Rl; Aishima, J.; Foadi, J.; Morgan, Aw; Robinson, Ji; Nettleship, Je; Owens, Rj; Moraes, I.; Fry, Ee; Grimes, JM; Harlos, K.; Kotecha, A.; Ren, J.; Sutton, G.

2012-01-01

267

Development of Spectroelectrochemical Cells for in situ Neutron Reflectometry  

Science.gov (United States)

A new spectroelectrochemical cell for in situ neutron reflectometry was developed. Electrochemical reactions were determined using this in situ cell with a LiMn2O4/SrRuO3 multi layer thin film. Changes in interfacial structures on the surface of the thin film are also observed by in situ neutron reflectivity measurements. The performances of this in situ cell were expected the determination of changes on the interface between the electrodes and electrolytes.

Yonemura, M.; Hirayama, M.; Suzuki, K.; Kanno, R.; Torikai, N.; Yamada, N. L.

2014-04-01

268

High resolution measurements of carbon monoxide along a late Holocene Greenland ice core: evidence for in-situ production  

Directory of Open Access Journals (Sweden)

Full Text Available We present high-resolution measurements of carbon monoxide (CO concentrations from continuous analysis of a shallow ice core from the North Greenland Eemian Ice Drilling project (NEEM-2011-S1. An Optical Feedback – Cavity Enhanced Absorption Spectrometer (OF-CEAS was coupled to a continuous melter system during a 4-week laboratory-based measurement campaign. This analytical setup generates highly stable measurements of CO concentrations with an external precision of 7.8 ppbv (1 sigma based on a comparison of replicate cores. The NEEM-2011-S1 CO record spans 1800 yr and exhibits highly variable concentrations at the scale of annual layers, ranging from 75 to 1327 ppbv. The most recent section of this record (i.e. since 1700 AD agrees with existing discrete CO measurements from the Eurocore ice core and the deep NEEM firn. However, it is difficult to interpret in terms of atmospheric CO variation due to high frequency, high amplitude spikes in the data. 68% of the elevated CO spikes are observed in ice layers enriched with pyrogenic aerosols. Such aerosols, originating from boreal biomass burning emissions, contain organic compounds, which can be oxidized or photodissociated to produce CO in-situ. We suggest that elevated CO concentration features could present a new integrative proxy for past biomass burning history. Furthermore, the NEEM-2011-S1 record reveals an increase in baseline CO level prior to 1700 AD (129 m depth, with the concentration remaining high even for ice layers depleted in dissolved organic carbon (DOC. Overall, the processes driving in-situ production of CO within the NEEM ice are complex and may involve multiple chemical pathways.

X. Faïn

2013-05-01

269

Practical application of in situ aerosol measurement  

Energy Technology Data Exchange (ETDEWEB)

The use of in situ, real-time measurement techniques permits the characterization of airborne droplets and particles under conditions where traditional sampling methods can fail. For example, sampling method rely on the ability to sample and transport particles without biasing the properties of interest, and often are not applicable in harsh environment. Although in situ methods offer unique opportunities in these cases, these techniques introduce new concerns and must be used carefully if accurate measurement are to be made. Several in situ measurement techniques are reviewed here. As the field is rapidly evolving, the discussion is limited to those techniques which: (1) are commercially available, (2) provide real-time output, (3) measure the aerosol size distribution. Discussion is divided between single particle counters (which provide a flux-based or temporal measurement) and ensemble techniques (which provide a concentration-based or spatial measurement). Specific techniques discussed include phase Doppler, Mie scattering, and Fraunhofer diffraction, and commercial instruments based on these techniques.

O`Hern, T.J.; Rader, D.J.

1993-09-01

270

Hangingstone experimental in situ combustion pilot project  

Energy Technology Data Exchange (ETDEWEB)

This paper discussed an experimental in situ combustion pilot project conducted by Excelsior Energy Limited at its oil sands lease in Hangingstone, Alberta. Studies have shown that production of the area is economically feasible. The proprietary in situ overhead gravity drainage combustion technology used a network of vertical wells positioned in relation to a horizontal drain. Air was injected at injection wells to sustain a combustion chamber. The melted bitumen and condensed water flowed down to the drain positioned at a lower position in the reservoir system. The well network was designed to provide for the bulk separation of fluids in the reservoir. Combustion gases were separated for collection at vent wells and then returned to a central facility. The fluid velocity of the bitumens is similar to fluid flow velocity observed in steam assisted gravity drainage (SAGD) operations. A pre-ignition heat cycle that used cyclic steam techniques to develop warm mobility paths in the reservoir was used to develop a combustion chamber. Computerized simulations demonstrated that use of the technology resulted in water consumption reductions of 92 percent. Fuel gas consumption was reduced by 69 percent when compared with SAGD processes. A comparative economic analysis of SAGD and the in situ combustion technology was also included. 2 tabs., 5 figs.

Bailey, R. [Excelsior Energy Ltd., Calgary, AB (Canada)

2010-07-01

271

Human activity and rest in situ.  

Science.gov (United States)

Our lives are structured by the daily alternation of activity and rest, of wake and sleep. Despite significant advances in circadian and sleep research, we still lack answers to many of the most fundamental questions about this conspicuous behavioral pattern. We strongly believe that investigating this pattern in entrained conditions, real-life and daily contexts-in situ-will help the field to elucidate some of these central questions. Here, we present two common approaches for in situ investigation of human activity and rest: the Munich ChronoType Questionnaire (MCTQ) and actimetry. In the first half of this chapter, we provide detailed instructions on how to use and interpret the MCTQ. In addition, we give an overview of the main insights gained with this instrument over the past 10 years, including some new findings on the interaction of light and age on sleep timing. In the second half of this chapter, we introduce the reader to the method of actimetry and share our experience in basic analysis techniques, including visualization, smoothing, and cosine model fitting of in situ recorded data. Additionally, we describe our new approach to automatically detect sleep from activity recordings. Our vision is that the broad use of such easy techniques in real-life settings combined with automated analyses will lead to the creation of large databases. The resulting power of big numbers will promote our understanding of such fundamental biological phenomena as sleep. PMID:25707281

Roenneberg, Till; Keller, Lena K; Fischer, Dorothee; Matera, Joana L; Vetter, Céline; Winnebeck, Eva C

2015-01-01

272

In situ remediation: Developing containment technologies  

International Nuclear Information System (INIS)

The In Situ Remediation Integrated Program (ISR IP) was established by the US Department of Energy's (DOE) Office of Technology Development (OTD) to advance the state-of-the art of innovative in situ remediation technologies to the point of demonstration, and to broaden the applicability of these technologies to the widely varying site remediation requirements throughout the DOE complex. This program complements ongoing demonstration programs being conducted at several DOE sites. The ISR-IP has been conducting baseline assessments of in situ technologies to support program planning. One of the assessments has focused on evaluating subsurface containment barrier technologies to identify the current state-of-the-art and determine R and D requirements to enable the deployment of these technologies. DOE's needs are mostly driven by issues concerning the large number of sites requiring remediation, the wide variation among the sites themselves, and the broad range of contaminants at these sites. Many of the sites contain a mixture of organic and inorganic hazardous waste and radioactive waste in a variety of media. Current remedial action strategies for hazardous waste sites are considering containment mostly as an interim action to prevent migration of contaminants from the site until a Record of Decision is made. In some cases, containment is also considered as a remedial action alternative where it is determined to be the best compromise between cost and effectiveness over a relatively short period of time (about 30 years)

273

In situ electrokinetic remediation of As-, Cu-, and Pb-contaminated paddy soil using hexagonal electrode configuration: a full scale study.  

Science.gov (United States)

We investigated the in situ applicability of the electrokinetic process with a hexagonal electrode configuration in order to remediate arsenic (As)-, copper (Cu)-, and lead (Pb)-contaminated paddy rice field soil at a field scale (width 17 m, length 12.2 m, and depth 1.6 m). An iron electrode was used in order to prevent the severe acidification of the soil near the anode. We selected ethylenediaminetetraacetic acid (EDTA) as a pursing electrolyte to enhance the extraction of Cu and Pb. The system removed 44.4% of the As, 40.3% of the Cu, and 46.6% of the Pb after 24 weeks of operation. Fractionation analysis showed that the As bound to amorphous ion (Fe) and aluminum (Al) oxyhydroxides was changed into a form of As specifically bound. In the case of Cu and Pb, the fraction bound to Fe-Mn oxyhydroxide primarily decreased. The EDTA formed negatively charged complexes with Cu and Pb, and those complexes were transported toward the anode. The energy consumption was very low compared to that on a small scale because there was less energy consumption due to Joule heating. These results show that the in situ electrokinetic process could be applied in order to remediate paddy rice fields contaminated with multiple metals. PMID:25103944

Jeon, Eun-Ki; Jung, Ji-Min; Kim, Woo-Seung; Ko, Sung-Hwan; Baek, Kitae

2015-01-01

274

Hybridization for HER2 testing in gastric carcinoma: a comparison of fluorescence in situ hybridization with a novel fully automated dual-color silver in situ hybridization  

OpenAIRE

Abstract Aims: Amplification of the human epidermal growth factor receptor 2 (HER2) gene has been reported in gastric carcinoma (GC). Accordingly, trastuzumab plus chemotherapy has recently become the new standard treatment for HER2 positive advanced GCs. Methods and results: We sought to compare the alleged gold standard for hybridization (FISH) with a novel fully automated brightfield dual-color silver enhanced in situ hybridization (SISH) in a series of 166 GC samples. Additi...

Lopez-rios, Fernando; Garcia-garcia, Elena; Gomez-martin, Carlos; Angulo, Barbara; Conde, Esther; Suarez-gauthier, Ana; Adrados, Magdalena; Perna, Cristian; Rodriguez-peralto, Jose Luis; Hidalgo, Manuel

2011-01-01

275

IN SITU FIELD TESTING OF PROCESSES  

International Nuclear Information System (INIS)

The purpose of this scientific analysis report is to update and document the data and subsequent analyses from ambient field-testing activities performed in underground drifts and surface-based boreholes through unsaturated zone (UZ) tuff rock units. In situ testing, monitoring, and associated laboratory studies are conducted to directly assess and evaluate the waste emplacement environment and the natural barriers to radionuclide transport at Yucca Mountain. This scientific analysis report supports and provides data to UZ flow and transport model reports, which in turn contribute to the Total System Performance Assessment (TSPA) of Yucca Mountain, an important document for the license application (LA). The objectives of ambient field-testing activities are described in Section 1.1. This report is the third revision (REV 03), which supercedes2. The scientific analysis of data for inputs to model calibration and validation as documented in2 were developed in accordance with the Technical Work Plan (TWP) ''Technical Work Plan for: Performance Assessment Unsaturated Zone'' (BSC 2004 [DIRS 167969]). This revision was developed in accordance with the ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Section 1.2.4) for better integrated, consistent, transparent, traceable, and more complete documentation in this scientific analysis report and associated UZ flow and transport model reports. No additional testing or analyses were performed as part of this revision. The list of relevant acceptance criteria is provided by ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654]), Table 3-1. Additional deviations from the TWP regarding the features, events, and processes (FEPs) list are discussed in Section 1.3. Documentation in this report includes descriptions of how, and under what conditions, the tests were conducted. The descriptions and analyses provide data useful for refining and confirming the understanding of flow, drift seepage, and transport processes in the UZ. The UZ testing activities included measurement of permeability distribution, quantification of the seepage of water into the drifts, evaluation of fracture-matrix interaction, study of flow along faults, testing of flow and transport between drifts, characterization of hydrologic heterogeneity along drifts, estimation of drying effects on the rock surrounding the drifts due to ventilation, monitoring of moisture conditions in open and sealed drifts, and determination of the degree of minimum construction water migration below drift. These field tests were conducted in two underground drifts at Yucca Mountain, the Exploratory Studies Facility (ESF) drift, and the cross-drift for Enhanced Characterization of the Repository Block (ECRB), as described in Section 1.2. Samples collected in boreholes and underground drifts have been used for additional hydrochemical and isotopic analyses for additional understanding of the UZ setting. The UZ transport tests conducted at the nearby Busted Butte site (see Figure 1-4) are also described in this scientific analysis report

276

21 CFR 866.4700 - Automated fluorescence in situ hybridization (FISH) enumeration systems.  

Science.gov (United States)

... false Automated fluorescence in situ hybridization (FISH) enumeration...4700 Automated fluorescence in situ hybridization (FISH) enumeration...Document: Automated Fluorescence in situ Hybridization (FISH)...

2010-04-01

277

In-situ stress measurement at a candidate repository horizon  

International Nuclear Information System (INIS)

The state of in-situ stress under the Hanford Site has attracted attention in recent years because of the core disking phenomenon observed during exploration drilling, an indicator of likely high horizontal stress. Efforts made to elucidate this phenomenon by core analysis and numerical modeling studies have enhanced the understanding of the rock failure mechanism and served to delineate approximate conditions for which disking might occur. The hydraulic fracturing stress measurements conducted in the Umtanum flow in fiscal year 1982 provided, for the first time, direct and quantitative information on the stress state of a candidate repository horizon in basalt. This paper summarizes the measurement method employed, the test results, and future Basalt Waste Isolation Project (BWIP) plans. 4 figures

278

In situ reacted rare-earth hexaaluminate interphases  

International Nuclear Information System (INIS)

A novel in situ reaction between a ceria-doped zirconia interphase coating on Saphikon fibers and an outer alumina coating has resulted in the formation of oriented hexaaluminate platelets which can act as a low fracture energy interface barrier for crack deflection in oxide-oxide ceramic-matrix composites (CMCs). The reaction proceeds only in reducing environments where the reduction of the cerium and zirconium ions to their 3+ valent state causes a destabilization phenomenon consistent with previously reported findings. The diffusion of the cerium from the zirconia into solid solution with the alumina can stabilize the layered hexaaluminate structure. Preferred orientational growth of the hexaaluminate parallel to the coating interface was observed which is the required orientation for enhanced debonding at the fiber/matrix interface in long-fiber-reinforced CMCs

279

Irradiation-related amorphization and crystallization: In situ transmission electron microscope studies  

Energy Technology Data Exchange (ETDEWEB)

Interfacing an ion accelerator to a transmission electron microscope (TEM) allows the analytical functions of TEM imaging and diffraction to be employed during ion-irradiation effects studies. At present there are twelve such installations in Japan, one in France and one in the US. This paper treats several aspects of in situ studies involving electron and ion beam induced and enhanced phase transformations and presents results of several in situ experiments to illustrate the dynamics of this approach in the materials science of irradiation effects. The paper describes the ion- and electron-induced amorphization of CuTi; the ion-irradiation-enhanced transformation of TiCr{sub 2}; and the ion- and electron-irradiation-enhanced crystallization of CoSi{sub 2}.

Allen, C.W.

1994-04-01

280

Irradiation-related amorphization and crystallization: In situ transmission electron microscope studies  

International Nuclear Information System (INIS)

Interfacing an ion accelerator to a transmission electron microscope (TEM) allows the analytical functions of TEM imaging and diffraction to be employed during ion-irradiation effects studies. At present there are twelve such installations in Japan, one in France and one in the US. This paper treats several aspects of in situ studies involving electron and ion beam induced and enhanced phase transformations and presents results of several in situ experiments to illustrate the dynamics of this approach in the materials science of irradiation effects. The paper describes the ion- and electron-induced amorphization of CuTi; the ion-irradiation-enhanced transformation of TiCr2; and the ion- and electron-irradiation-enhanced crystallization of CoSi2

281

DESIGN AND DEVELOPMENT OF pH-TRIGGERED IN SITU GELLING SYSTEM OF CIPROFLOXACIN  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of the present work was formulation and evaluation of in situ gelling system of ciprofloxacin. The poor bioavailability and therapeutic response exhibited by conventional ophthalmic solutions due to rapid precorneal elimination of the drug may be overcome by the use of in situ gel-forming systems that are instilled as drops into the eye and undergo a sol–gel transition in the cul-de-sac. Hence, the purpose of the present work was to formulate pH-triggered, temperature triggered & ion activated in situ Gelling system of ciprofloxacin to provide sustained release of drug based on polymeric carriers that undergo sol-to-gel transition upon change in pH. The ciprofloxacin in situ gelling system formulated by using poly acrylic acid (Carbopol 934 in combination with hydroxyl propylmethyl cellulose (HPMC which acted as viscosity enhancing agent. The developed formulation was efficacious, stable, non-irritant and provided sustained release over 8-hour period and it is a viable alternative to conventional eye drops by virtue of its ability to enhance bioavailability through its longer precorneal residence time & ability to produced sustained drug release.

Lokhande Umesh Ramchandra

2012-05-01

282

Apparatus for in situ monitoring of copper in coastal waters.  

Science.gov (United States)

Apparatus is designed and tested to determine metals in situ in seawater. Voltammetry with a vibrating gold microwire electrode (VGME) is combined with a battery powered potentiostat and a processor board and is tested for in situ monitoring of copper (Cu) in coastal waters. The VGME was combined with solid state reference and counter electrodes to make a single vibrating probe which was rated up to a depth of 40 m. The measuring mode for Cu was square-wave anodic stripping voltammetry whilst dissolved oxygen (DO) was monitored by a linear sweep scan in a negative potential direction. The working electrode was reactivated between measurements using a suitable potential sequence. The novelties of this work are the field-testing of apparatus incorporating a VGME for copper monitoring, which eliminates the need for pumping and reagents, but has sufficient sensitivity for low ambient levels of copper, and the use of a novel potential sequence to stabilise the response over a long time period. The apparatus has a measuring time of about 6 weeks and a measuring frequency of 12 h(-1). Measurement is reagent-free and power use is low as no pump is required. Experiments are carried out to test the stability of response of the system at various temperatures and its robustness with respect to long-term copper monitoring. Preliminary data were obtained during autonomous deployment over several weeks on a buoy in the Irish Sea. Vertical movement of the buoy caused individual measurements to have a variability of about 15%. It was found that longer term variability of the electrode could be minimised by normalisation of the Cu response over that of DO as the response was related to diffusion through the electrode surface which was similarly affected. The detected fraction of Cu (labile Cu) amounted to 1.5-4 nM during different deployments at a total Cu concentration of ?10 nM. The same ratio was found by voltammetry in samples taken to the laboratory. The new apparatus has demonstrated that metals in coastal waters can be monitored at trace level, much facilitating the monitoring of outfalls and local water contamination. Because of its sensitivity the apparatus would be of use in estuarine as well as coastal waters, with the aim of monitoring intermittent variability in the copper concentration. PMID:22983404

Chapman, Conrad S; Cooke, Richard D; Salaün, Pascal; van den Berg, Constant M G

2012-10-26

283

Polypropylene/graphite nanocomposites by in situ polymerization; Nanocompositos polipropileno/grafite via polimerizacao in situ  

Energy Technology Data Exchange (ETDEWEB)

This work presents the synthesis of nanocomposites of polypropylene/graphite by in situ polymerization using metallocene catalyst and graphene nanosheets. Initially was analyzed which of the metallocene catalysts rac-Et(Ind){sub 2}ZrCl{sub 2} or rac-Me{sub 2}Si(Ind){sub 2}ZrCl{sub 2} produces polypropylene with mechanical properties more relevant. Then it were performed the in situ polymerization reactions to obtain the nanocomposites. The polymeric materials were characterized by XRD, DSC, GPC and DMTA. (author)

Milani, Marceo A.; Galland, Giselda B., E-mail: griselda@iq.ufrgs.br [Instituto de Quimica, UFRGS, Porto Alegre, RS (Brazil); Quijada, Raul [Universidade de Chile, Santiago (Chile). Centro de Ciencias de los Materiales; Basso, Nara R.S. [Fac. de Quimica, PUCRS, Porto Alegre, RS (Brazil)

2011-07-01

284

In-situ thermal testing program strategy  

International Nuclear Information System (INIS)

In the past year the Yucca Mountain Site Characterization Project has implemented a new Program Approach to the licensing process. The Program Approach suggests a step-wise approach to licensing in which the early phases will require less site information than previously planned and necessitate a lesser degree of confidence in the longer-term performance of the repository. Under the Program Approach, the thermal test program is divided into two principal phases: (1) short-term in situ tests (in the 1996 to 2000 time period) and laboratory thermal tests to obtain preclosure information, parameters, and data along with bounding information for postclosure performance; and (2) longer-term in situ tests to obtain additional data regarding postclosure performance. This effort necessitates a rethinking of the testing program because the amount of information needed for the initial licensing phase is less than previously planned. This document proposes a revised and consolidated in situ thermal test program (including supporting laboratory tests) that is structured to meet the needs of the Program Approach. A customer-supplier model is used to define the Project data needs. These data needs, along with other requirements, were then used to define a set of conceptual experiments that will provide the required data within the constraints of the Program Approach schedule. The conceptual thermal tests presented in this document represent a consolidation and update of previously defined tests that should result in a more efficient use of Project resources. This document focuses on defining the requirements and tests needed to satisfy the goal of a successful license application in 2001, should the site be found suitable

285

In-situ nanoindentation in the SEM  

Directory of Open Access Journals (Sweden)

Full Text Available Over the past few decades scanning electron microscopes (SEMs have become commonplace instruments in both academic and industrial settings. With their superior spatial resolution, SEMs have replaced visible-light microscopes in many applications, particularly as the surge in interest in nanotechnology dictates smaller and smaller structures. The limits of these microscopes are now being pushed even further with the development of new in-situ testing methods. Combining SEM imaging with complementary characterization techniques can help to paint a more complete picture of materials behavior. Here we report on progress in the development of a compact, vacuum-compatible instrument capable of quantitative nanomechanical testing in the SEM1.

Julia D. Nowak

2010-01-01

286

Demonstration testing and evaluation of in situ soil heating. Revision 1, Demonstration system design  

International Nuclear Information System (INIS)

Over the last nine years IIT Research Institute (IITRI) has been developing and testing the in situ heating and soil decontamination process for the remediation of soils containing hazardous organic contaminants. In this process the soil is heated in situ using electrical energy. The contaminants are removed from the soil due to enhanced vaporization, steam distillation and stripping. The vaporized contaminants, water vapor and air are recovered from the heated zone by means of a vacuum manifold system which collects gases from below surface as well as from the soil surface. A vapor barrier is used to prevent fugitive emissions of the contaminants and to control air infiltration to minimize dilution of the contaminant gases and vapors. The recovered gases and vapors are conveyed to an on site vapor treatment system for the clean up of the vent gases. Electrical energy is applied to the soil by forming an array of electrodes in the soil which are electrically interconnected and supplied with power. The electrodes are placed in drilled bore holes which are made through the contaminated zone. There are two versions of the in situ heating and soil treatment process: the f irst version is called the In Situ Radio Frequency (RF) Soil Decontamination Process and the second version is called the In Situ Electromagnetic (EM) Soil Decontamination Process. The first version, the RF Process is capable of heating the soil in a temperature range of 100 degrees to 400 degrees C. The soil temperature in the second version, the EM Process, is limited to the boiling point of water under native conditions. Thus the soil will be heated to a temperature of about 85 degrees to 95 degrees C. In this project IITRI will demonstrate the EM Process for in situ soil decontamination at K-25 Site due to the fact that most of the contaminants of concern are volatile organics which can be removed by heating the soil to a temperature range of 85 degrees to 95 degrees C

287

Inherently safe in situ uranium recovery  

International Nuclear Information System (INIS)

Expansion of uranium mining in the United States is a concern to some environmental groups and sovereign Native American Nations. An approach which may alleviate some problems is to develop inherently safe in situ uranium recovery ('ISR') technologies. Current ISR technology relies on chemical extraction of trace levels of uranium from aquifers that, once mined, can still contain dissolved uranium and other trace metals that are a health concern. Existing ISR operations are few in number; however, high uranium prices are driving the industry to consider expanding operations nation-wide. Environmental concerns and enforcement of the new 30 ppb uranium drinking water standard may make opening new mining operations more difficult and costly. Here we propose a technological fix: the development of inherently safe in situ recovery (ISISR) methods. The four central features of an ISISR approach are: (1) New 'green' leachants that break down predictably in the subsurface, leaving uranium, and associated trace metals, in an immobile form; (2) Post-leachant uranium/metals-immobilizing washes that provide a backup decontamination process; (3) An optimized well-field design that increases uranium recovery efficiency and minimizes excursions of contaminated water; and (4) A combined hydrologic/geochemical protocol for designing low-cost post-extraction long-term monitoring. ISISR would bring larger amounts of uranium to the surface, leave fewer toxic metals in the aquifer, and co fewer toxic metals in the aquifer, and cost less to monitor safely - thus providing a 'win-win-win' solution to all stakeholders.

288

Mitigating in situ oil sands carbon costs  

Energy Technology Data Exchange (ETDEWEB)

Carbon capture and sequestration is a complex problem with a variety of dimensions that need to be considered. The political, social, and regulatory pressures are forcing carbon costs on the oil sands industry in an effort to reduce the carbon footprint of oil sands operations. This paper reviewed the political, social, and regulatory pressures and obligations for the in-situ oil sands industry. It presented the views and insights of Laricina Energy on the carbon challenge. It also described the initiatives that Laricina Energy is taking to manage these imperatives and outlined the challenges the industry is facing. The purpose of the paper was to encourage dialogue and collaboration by the oil sands industry. The paper also described the dimensions of the carbon problem and how the industry can contribute to a solution. Last, the paper reviewed the parameters of carbon dioxide or greenhouse gas containment and storage issues. It was concluded that the regulatory and policy requirements need to be clarified so that industry understands the new business landscape as well as the requirements that influence the economics of in-situ oil sands development. 7 refs., 7 figs.

Theriault, D.J.; Peterson, J. [Laricina Energy Ltd., Calgary, AB (Canada); Heinrichs, H. [Canadian Chemical Technology Inc., Calgary, AB (Canada)

2008-10-15

289

BEATRIX-II: In situ tritium test  

Energy Technology Data Exchange (ETDEWEB)

The BEATRIX-II irradiation experiment is an in-situ tritium release experiment being carried out in the Fast Flux Test Facility (FFTF) reactor to evaluate the tritium release characteristics of fusion solid breeder materials. A sophisticated tritium gas handling system has been developed to continuously monitor the tritium recovery from the specimens and facilitate tritium removal from the experiment's sweep gas flow stream. The in-situ recovery experiment accommodates two different in-reactor specimen canisters with individual gas streams and temperature monitoring/control. Ionization chambers have been specifically designed to respond to the rapid changes in the tritium release rate at the anticipated tritium concentrations. Two ceramic electrolysis cells have proved effective in reducing the moisture in the gas streams to hydrogen/tritium. A tritium getter system, capable of reducing the tritium level by a factor greater than 4000, is used to reduce the tritium in the sweep gas to a level acceptable for release.

Baker, D.E. (Westinghouse Hanford Co., Richland, WA (USA)); Kuraswa, T. (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)); Miller, J.M. (Atomic Energy of Canada Ltd., Chalk River, ON (Canada). Chalk River Nuclear Labs.); Slagle, O.D. (Pacific Northwest Lab., Richland, WA (USA))

1990-01-01

290

Molecular cytogenetics using fluorescence in situ hybridization  

Energy Technology Data Exchange (ETDEWEB)

Fluorescence in situ hybridization (FISH) with chromosome-specific probes enables several new areas of cytogenetic investigation by allowing visual determination of the presence and normality of specific genetic sequences in single metaphase or interphase cells. in this approach, termed molecular cytogenetics, the genetic loci to be analyzed are made microscopically visible in single cells using in situ hybridization with nucleic acid probes specific to these loci. To accomplish this, the DNA in the target cells is made single stranded by thermal denaturation and incubated with single-stranded, chemically modified probe under conditions where the probe will anneal only with DNA sequences to which it has high DNA sequence homology. The bound probe is then made visible by treatment with a fluorescent reagent such as fluorescein that binds to the chemical modification carried by the probe. The DNA to which the probe does not bind is made visible by staining with a dye such as propidium iodide that fluoresces at a wavelength different from that of the reagent used for probe visualization. We show in this report that probes are now available that make this technique useful for biological dosimetry, prenatal diagnosis and cancer biology. 31 refs., 3 figs.

Gray, J.W.; Kuo, Wen-Lin; Lucas, J.; Pinkel, D.; Weier, H-U.; Yu, Loh-Chung.

1990-12-07

291

In situ migration experiment in argillaceous formation  

International Nuclear Information System (INIS)

International cooperative R and D has been performed within the five years framework of the bilateral agreement between PNC (Power Reactor and Nuclear Fuel Development Corporation) and SCK/CEN (Studiecentrum voor Kernergie/Centre D'etude de L'energie Nucleaire, Mol, Belgium) which is focused on 'The Migration Experiment in argillaceous formation.' This Tertiary argillaceous formation, called Boom clay, is located at about 230m depth in Mol-Dessel area, Belgium. The argillaceous rock is considered to have a high capability for retardation to radionuclides when they migrate in geosphere because of a high content of clay minerals and dissolved carbon-rich pore water. The main purpose of this collaboration work is to characterize the migration phenomena in sedimentary rock through understanding of the behaviour of radionuclides migration in the argillaceous formation. The present report describes the preliminary results of in situ one-dimensional migration experiment with labelled clay core emplaced in borehole under advective condition. In the experiment, radioactive tracer Sr-85 and Eu-152+154 have been used in order to determine the apparent dispersion coefficient and retardation factor of Boom clay. Finally, the following conclusions were obtained by in situ measurement and calculation based on a appropriate migration model; a) From the Sr-85 experiment, diffusive behavior is interpreted to be a dominant phenomena on radionuclides transportation. b) From the Eu-152+154 experiment, very small non-retarded fraction is observed. (author)

292

GAS TURBINE REHEAT USING IN SITU COMBUSTION  

Energy Technology Data Exchange (ETDEWEB)

In situ reheat is an alternative to traditional gas turbine reheat design in which fuel is fed through airfoils rather than in a bulky discrete combustor separating HP and LP turbines. The goals are to achieve increased power output and/or efficiency without higher emissions. In this program the scientific basis for achieving burnout with low emissions has been explored. In Task 1, Blade Path Aerodynamics, design options were evaluated using CFD in terms of burnout, increase of power output, and possible hot streaking. It was concluded that Vane 1 injection in a conventional 4-stage turbine was preferred. Vane 2 injection after vane 1 injection was possible, but of marginal benefit. In Task 2, Combustion and Emissions, detailed chemical kinetics modeling, validated by Task 3, Sub-Scale Testing, experiments, resulted in the same conclusions, with the added conclusion that some increase in emissions was expected. In Task 4, Conceptual Design and Development Plan, Siemens Westinghouse power cycle analysis software was used to evaluate alternative in situ reheat design options. Only single stage reheat, via vane 1, was found to have merit, consistent with prior Tasks. Unifying the results of all the tasks, a conceptual design for single stage reheat utilizing 24 holes, 1.8 mm diameter, at the trailing edge of vane 1 is presented. A development plan is presented.

D.M. Bachovchin; T.E. Lippert; R.A. Newby P.G.A. Cizmas

2004-05-17

293

Mitigating Extreme Environments for In-Situ Jupiter and Venus Missions  

Science.gov (United States)

In response to the recommendations by the National Research Council (NRC), NASA's Solar System Exploration (SSE) Roadmap identified the in situ exploration of Venus and Jupiter as high priority science objectives. For Jupiter, deep entry probes are recommended, which would descend to approx.250 km - measured from the 1 bar pressure depth. At this level the pressure would correspond to approx.100 bar and the temperature would reach approx.500(deg)C. Similarly, at the surface of Venus the temperature and pressure conditions are approx.460(deg)C and approx.90 bar. Lifetime of the Jupiter probes during descent can be measured in hours, while in{situ operations at and near the surface of Venus are envisioned over weeks or months. In this paper we discuss technologies, which share commonalities in mitigating these extreme conditions over proposed mission lifetimes, specially focusing on pressure and temperature environments.

Balint, Tibor S.; Kolawa, Elizabeth A.; Cutts, James A.

2006-01-01

294

Studies on in situ Cu-Nb composites  

International Nuclear Information System (INIS)

As part of a program of developing Cu-Nb3Sn composite superconductors through in situ techniques, systematic investigations have been performed on Cu-Nb composites containing niobium up to 30 at %. These alloys, prepared by an arc melting technique, show excellent filamentary morphology when reduced to fine wires. The T /SUB c/ (midpoint) of these composite wires is 8.8 K with a ?T /SUB c/ = 0.12 K. The self-field overall J /SUB c/ of 0.21-mm-diameter wires of these composites at 4.2 K IS 2.5 X 105 a cm -2. The J /SUB C/ increases with area red;uction ratio up to a value of 2000 and has not attained saturation. Kramer plots (J /SUB c/ /SUP 1/2/ H /SUB c/ /SUP 1/4/ versus H) of the compsite wire yield a value of effective upper critical field H /SUB c2/ of 1.1 T, significantly higher than for pure niobium wire. Enhancement of H /SUB c2/ is attributed to the increase of the normal resistivity of the niobium filaments. In situ tapes show large critical current anisotropy with applied field direction, strongly indicating that surface flux pinning at the interface boundaries between the supe4rconducting filament and matrix is important in these materials. The peak in the volume pinning force, versus reduced field plots occurs for Cu-Nb (20 at %) composites consistently at 0.25, very close to the predicted value on the basis of surface flux pinning

295

In situ vitrification large-scale operational acceptance test analysis  

International Nuclear Information System (INIS)

A thermal treatment process is currently under study to provide possible enhancement of in-place stabilization of transuranic and chemically contaminated soil sites. The process is known as in situ vitrification (ISV). In situ vitrification is a remedial action process that destroys solid and liquid organic contaminants and incorporates radionuclides into a glass-like material that renders contaminants substantially less mobile and less likely to impact the environment. A large-scale operational acceptance test (LSOAT) was recently completed in which more than 180 t of vitrified soil were produced in each of three adjacent settings. The LSOAT demonstrated that the process conforms to the functional design criteria necessary for the large-scale radioactive test (LSRT) to be conducted following verification of the performance capabilities of the process. The energy requirements and vitrified block size, shape, and mass are sufficiently equivalent to those predicted by the ISV mathematical model to confirm its usefulness as a predictive tool. The LSOAT demonstrated an electrode replacement technique, which can be used if an electrode fails, and techniques have been identified to minimize air oxidation, thereby extending electrode life. A statistical analysis was employed during the LSOAT to identify graphite collars and an insulative surface as successful cold cap subsidence techniques. The LSOAT also showed that even under worst-case conditions, the off-gas system exceeds the flow requirements necessary to maintain a negative pressure on the hood covering the area being vitrified. The retention of simulated radionuclides and chemicals in the soil and off-gas system exceeds requirements so that projected emissions are one to two orders of magnitude below the maximum permissible concentrations of contaminants at the stack

296

In situ destruction of contaminants via hydrous pyrolysis/  

Energy Technology Data Exchange (ETDEWEB)

A field test of hydrous pyrolysis/oxidation (HPO) was conducted during the summer of 1997, during a commercial application of thermal remediation (Dynamic Underground Stripping (DUS)) at the Visalia Pole Yard (a super-fund site) in southern California. At Visalia, Southern California Edison Co. is applying the DUS thermal remediation method to clean up a large (4.3 acre) site contaminated with pole-treating compounds. This is a full-scale cleanup, during which initial extraction of contaminants is augmented by combined steam/air injection in order to enhance the destruction of residual contaminants by HPO. Laboratory results indicate that the contaminants at Visaha react at similar rates to TCE, which has been the focus of extensive laboratory work (Knauss et al., 1998a-c). Field experimental results from this application yield valuable information (1) confirming the destruction of contaminants in soil and groundwater by HPO, (2) validating the predictive models used to design HP0 steam injection systems, (3) demonstrating that accurate field measurements of the critical fluid parameters can be obtained using existing monitoring wells and (4) obtaining a reasonable prediction of the cost and effectiveness of HPO, working at a commercial scale and with commercial partners. The goal of our additional study and demonstration in conjunction with Edison has been to obtain early proof of hydrous pyrolysis/oxidation in the field, and validate our predictive models and monitoring strategies. This demonstration provides valuable economic and practicability data obtained on a commercial scale, with more detailed field validation than is commonly available on a commercially-conducted cleanup. The results of LLNL s field experiments constrain the destruction rates throughout the site, and enable site management to make accurate estimates of total in situ destruction based on the recovered carbon. As of October, 1998, over 900,000 lb of contaminant have been removed from the site; about 18% of this has been destroyed in situ.

Aines, R D; Carrigan, C; Chiarappa, M; Eaker, C; Hudson, B; Knauss, K; Leif, R; Newmark, R L; Richards, J; Sciarotta, T; Tompson, A; Weidner, R.

1998-12-01

297

Banned Books Week  

Science.gov (United States)

Next week is Banned Books Week, and the American Library Association (ALA) offers this site giving background on Banned Books Week and censorship as well as resources to help teachers, librarians, and booksellers observe the week. Once again, the Harry Potter series tops this year's list of most challenged books. At the ALA site, users will find the complete list as well as the most challenged books of the past decade. In addition, the site hosts a press kit, resources for sale to celebrate the week, links to other banned books sites, and a page on book burning.

298

Osteogenic potential of in situ TiO2 nanowire surfaces formed by thermal oxidation of titanium alloy substrate  

Science.gov (United States)

Titanium dioxide (TiO2) nanowire surface structures were fabricated in situ by a thermal oxidation process, and their ability to enhance the osteogenic potential of primary osteoblasts was investigated. Human osteoblasts were isolated from nasal bone and cultured on a TiO2 nanowires coated substrate to assess its in vitro cellular interaction. Bare featureless Ti-6Al-4V substrate was used as a control surface. Initial cell adhesion, cell proliferation, cell differentiation, cell mineralization, and osteogenic related gene expression were examined on the TiO2 nanowire surfaces as compared to the control surfaces after 2 weeks of culturing. Cell adhesion and cell proliferation were assayed by field emission scanning electron microscope (FESEM) and Alamar Blue reduction assay, respectively. The nanowire surfaces promoted better cell adhesion and spreading than the control surface, as well as leading to higher cell proliferation. Our results showed that osteoblasts grown onto the TiO2 nanowire surfaces displayed significantly higher production levels of alkaline phosphatase (ALP), extracellular (ECM) mineralization and genes expression of runt-related transcription factor (Runx2), bone sialoprotein (BSP), ostoepontin (OPN) and osteocalcin (OCN) compared to the control surfaces. This suggests the potential use of such surface modification on Ti-6Al-4V substrates as a promising means to improve the osteointegration of titanium based implants.

Tan, A. W.; Ismail, R.; Chua, K. H.; Ahmad, R.; Akbar, S. A.; Pingguan-Murphy, B.

2014-11-01

299

MR imaging evaluation of ductal carcinoma in situ and ductal carcinoma in situ with small invasive foci of breast  

International Nuclear Information System (INIS)

Objective: To retrospectively assess diagnostic accuracy of magnetic resonance imaging (MRI) in preoperative assessment of local extent of breast ductal carcinoma in situ (DCIS) and DCIS with small invasive foci, compared with the mammography and uhrasonography (US) imagings. Methods: Results of MRI, mammography, and US imaging from 17 consecutive women with known breast DCIS and DCIS with invasive foci were analyzed, and then compared with pathologic examination. Results: (1) Fourteen lesions showed enhancement on dynamic breast MRI, of which 11 lesions were no-mass-like enhancement. Six of 11 lesions appeared segmental enhancement, and 2 were regional enhancement. Ductal and multiple focal areas enhancement were 1 case respectively. Symmetric diffuse enhancement in bilateral breast was showed in 1 patient. Ductal dilation was visible in ipsilateral breast on pre-contrast MRI in 2 cases, which manifested bloody nipple discharge in clinical examination, and duct enhanced on post- contrast imaging in one of them. Two lesions appeared mass enhancement with irregular shape and homogeneous signal. Linear enhancement surrounding the oval homogeneous mass with smooth margin found in 1 case. (2) Thirteen of 17 patients underwent bilateral mammography. There were various findings in mammograms, including microcalcifications (6 cases), normal mammograms (2 cases), calcifications with other appearance (2 cases), and non-calcification ahnormity (3 cases). In 8 lesions with calcinormity (3 cases). In 8 lesions with calcifications, 5 were noted higher' probability of malignancy calcifications and 3 intermediate concern calcifications. Calcifications distributed clustered (5 cases), regional (2 cases) and diffuse (1 case) shape. (3) Sixteen of 17 patients were performed breast US examination. Eleven lesions, which were correct diagnosed, appeared higher echo spots within irregular lower echo area. One lesion diagnosed benign and 4 were negative on US examination. (4) Regarded the size measured on pathologic examination as golden standard, accordance of lesion extent was 13 of 17 case in MRI, 7 of 13 in mammography, and 7 of 16 in US. There were 2 lesions overestimation of extent in MRI, 3 in mammography, and 2 in US. Underestimation of extent showed 1 case and 3 cases in mammography and US imaging respectively. The difference was not significant (P=0.161). Conclusion: The MR imaging features of DCIS and DCIS with small invasive foci were characteristic. The combination of MRI and mammography could improve diagnostic accuracy. (authors)

300

Advances in the application of in situ electrical resistance heating  

International Nuclear Information System (INIS)

Electrical Resistance Heating (ERH) is an aggressive in situ thermal remediation technology that was developed by the U.S. Department of Energy from the original oil production technology to enhance vapor extraction remediation technologies in low permeability soils. Soil and groundwater are heated by the passage of electrical current through saturated and unsaturated soil between electrodes, not by the electrodes themselves. It is the resistance to the flow of electrical current that results in increased subsurface temperatures, and this is typically applied to the boiling point of water. It is estimated that more than 75 ERH applications have been performed. Capacity to perform these projects has increased over the years, and as many as 15 to 20 of these applications now being performed at any given time, mainly in North America, with some European applications. While the main focus has been to vaporize volatile organic compounds, as one would expect other semi-volatile and non-volatile organic compounds have also been encountered, resulting in observations of chemical and physical reactions that have not been normally incorporated into environmental restoration projects. One such reaction is hydrolysis, which is slow under normal groundwater temperatures, becomes very rapid under temperatures that can easily be achieved using ERH. As a result, these chemical and physical reactions are increasing the applicability of ERH in environmental restoration projects, treatienvironmental restoration projects, treating a wider variety of compounds and utilizing biotic and abiotic mechanisms to reduce energy costs. For the treatment of oil and coal tar residues from manufactured gas plants, a process TRS has called steam bubble floatation is used to physically remove the coal and oil tar from the soils for collection using conventional multi-phase collection methods. Heat-enhanced hydrolysis has been used to remediate dichloromethane from soils and groundwater at a site in Illinois, while heat-enhanced biotic and abiotic dehalogenation has been observed at the vast majority of the sites where ERH has been applied. With disposal options becoming more limited around the world, alternate in situ treatment methods for soil and groundwater restoration are becoming more important. Over the 10 years of commercialization of the ERH technology, soil and groundwater remediation mechanisms and processes that were not envisioned by the technology's developers expand the range of chemicals that have successfully been treated. This paper will discuss these processes and how these processes have been used to effect remediation of soil and groundwater where ERH has been employed. (authors)

301

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

Science.gov (United States)

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

Thüroff, S; Chaussy, C

1997-05-01

302

The LISA1 experiment: In-situ tritium release investigations  

Science.gov (United States)

The LISA1 experiment is a test of in-situ tritium release. Conducted in the SILOE reactor at CEN Grenoble, the experiment uses the same facilities as the LILA1. The experiment has six capsules, four with Li 2SiO 3, one with Li 4SiO 4 and one with LiAlO 2. Each capsule is separately purged. The tritium activity is determined by ionization chambers and scintillation counting. An important difference as compared to LILA1 is the use of zinc beds to reduce tritiated water and thereby prevent sorption of T 2O on the lines. Irradiation began on October 25, 1985 and was continued for three 3-week-cycles. The testing included systematic variation of four parameters: temperature (450 to 730°C), neutron flux (0.8 to 2.7 × 10 17 m -2s -1), sweep gas flow rate (1.8 to 7.0 1/h), and sweep gas composition (He, He+0.1% H 2, He+0.2% 0 2). Preliminary results are given.

Werle, H.; Abassin, J. J.; Briec, M.; Clemmer, R. G.; Elbel, H.; Häfner, H. E.; Masson, M.; Sciers, P.; Wedemeyer, H.

1986-11-01

303

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

Scientific Electronic Library Online (English)

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

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

304

In-situ Characterization of Cast Stainless Steel Microstructures  

Energy Technology Data Exchange (ETDEWEB)

Cast austenitic stainless steel (CASS) was commonly used in selected designs of nuclear power reactor systems for corrosion resistance and enhanced durability in service. CASS materials are generally coarse-grained and elastically anisotropic in nature, and are consequently difficult to inspect ultrasonically, largely due to detrimental effects of ultrasonic wave interactions with the coarse-grain microstructures. To address the inspection needs for these materials, new approaches that are robust to these phenomena are being developed. However, to enhance the probability of detecting flaws, knowledge of the microstructure and the corresponding acoustic properties of the material may be required. This paper discusses the application of ultrasonic backscatter measurement methods for classifying the microstructure of CASS components, when making measurements from the outside surface of the pipe or component. Results to date from laboratory experiments demonstrate the potential of these measurements to classify the material type of CASS for two homogeneous microstructures—equiaxed-grain material or columnar-grain material. Measurements on mixed or banded microstructures also show correlation with the estimated volume-fraction of columnar grains in the material. However, several operational issues will need to be addressed prior to applying this method for in-situ characterization of CASS microstructure.

Ramuhalli, Pradeep; Meyer, Ryan M.; Cinson, Anthony D.; Moran, Traci L.; Prowant, Matthew S.; Watson, Bruce E.; Mathews, Royce; Harris, Robert V.; Diaz, Aaron A.; Anderson, Michael T.

2012-09-01

305

Radiological aspects of in situ uranium recovery  

International Nuclear Information System (INIS)

In the last few years, there has been a significant increase in the demand for Uranium as historical inventories have been consumed and new reactor orders are being placed. Numerous mineralized properties around the world are being evaluated for Uranium recovery and new mining / milling projects are being evaluated and developed. Ore bodies which are considered uneconomical to mine by conventional methods such as tunneling or open pits, can be candidates for non-conventional recovery techniques, involving considerably less capital expenditure. Technologies such as Uranium in situ leaching in situ recovery (ISL / ISR), have enabled commercial scale mining and milling of relatively small ore pockets of lower grade, and may make a significant contribution to overall world wide uranium supplies over the next ten years. Commercial size solution mining production facilities have operated in the US since 1975. Solution mining involves the pumping of groundwater, fortified with oxidizing and complexing agents into an ore body, solubilizing the uranium in situ, and then pumping the solutions to the surface where they are fed to a processing plant. Processing involves ion exchange and may also include precipitation, drying or calcining and packaging operations depending on facility specifics. This paper presents an overview of the ISR process and the health physics monitoring programs developed at a number of commercial scale ISL / ISR Uranium recovery and production facilitiesUranium recovery and production facilities as a result of the radiological character of these processes. Although many radiological aspects of the process are similar to that of conventional mills, conventional-type tailings as such are not generated. However, liquid and solid byproduct materials may be generated and impounded. The quantity and radiological character of these by products are related to facility specifics. Some special monitoring considerations are presented which are required due to the manner in which Radon gas is evolved in the process and the unique aspects of controlling solution flow patterns underground. An overview of the major aspects of the health physics and radiation protection programs that were developed at these facilities are discussed and contrasted to circumstances of the current generation and state of the art of Uranium ISR technologies and facilities. (authors)

306

In situ Moessbauer spectroscopy of bimetallic FeRh/SiO2 catalysts at 295 K  

International Nuclear Information System (INIS)

The reduction behavior of bimetallic FeRh/SiO2 catalysts, prepared by means of the incipient wetness technique, has been studied with in situ Moessbauer spectroscopy at 295 K. The spectra demonstrate that coclustering of iron and rhodium occurs and that rhodum enhances the reducibility of iron. The appreciable changes in the spectra of the oxidized FeRh/SiO2 catalyst which occur upon chemisorption of H2 or CO indicate that the dispersion of the iron is high

307

Detection of chiral sum frequency generation vibrational spectra of proteins and peptides at interfaces in situ  

OpenAIRE

In this work, we demonstrate the feasibility to collect off-electronic resonance chiral sum frequency generation (SFG) vibrational spectra from interfacial proteins and peptides at the solid/liquid interface in situ. It is difficult to directly detect a chiral SFG vibrational spectrum from interfacial fibrinogen molecules. By adopting an interference enhancement method, such a chiral SFG vibrational spectrum can be deduced from interference spectra between the normal achiral spectrum and the ...

Wang, Jie; Chen, Xiaoyun; Clarke, Matthew L.; Chen, Zhan

2005-01-01

308

In situ SAXS and WAXS of zeolite microwave synthesis  

International Nuclear Information System (INIS)

In situ small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS) studies were carried out during microwave and conventional synthesis of zeolites using a custom waveguide reactor. In situ SAXS studies showed that the crystallization of NaY zeolite was preceded by a reorganization of nano-sized particles in their precursor solutions or gels. In situ WAXS was used to observe the rate of formation of crystalline zeolite products

309

In-situ gelling polymers for biomedical applications  

CERN Document Server

This book presents the research involving in situ gelling polymers and can be used as a guidebook for academics, industrialists and postgraduates interested in this area. This work summaries the academic contributions from the top authorities in the field and explore the fundamental principles of in situ gelling polymeric networks, along with examples of their major applications. This book aims to provide an up-to-date resource of in situ gelling polymer research.

2015-01-01

310

Solution (in situ leach) mining of uranium: an overview  

International Nuclear Information System (INIS)

Increases in the demand for and price of uranium have made in-situ mining an attractive alternative to the open-pit and underground U mining methods. Up to 50% of the known ore-bearing sandstone in the western U.S. can be mined using the in-situ mining method. In-situ mining also offers a significant environmental advantage. Restoration of the contaminated groundwater is discussed

311

An expert support model for in situ soil remediation  

OpenAIRE

This article presents an expert support model for in situ soil remediation. It combines knowledge and experiences obtained from previous in situ soil remediations. The aim of this model is to optimise knowledge transfer among the various parties involved in contaminated site management. Structured Knowledge Engineering (SKE) has been used as a framework for model development. This approach requires scrutinising all relevant data to answer questions related to an in situ soil remediation opera...

Okx, J. P.; Stein, A.

2000-01-01

312

Remote versus in situ turbulence measurements  

Science.gov (United States)

Comparisons of in situ wind and turbulence measurements made with the NASA B-57 instrumented aircraft and those remotely made with both radar and lidar systems are presented. Turbulence measurements with a lidar or radar system as compared with those from an aircraft are the principal themes. However, some discussion of mean wind speed and direction measurements is presented. First, the principle of measuring turbulence with Doppler lidar and radar is briefly and conceptually described. The comparisons with aircraft measurements are then discussed. Two studies in particular are addressed: one uses the JAWS Doppler radar data and the other uses data gathered both with the NASA Marshall Space Flight Center and the the NOAA Wave Propagation Lab. gound based lidars. Finally, some conclusions and recommendations are made.

Frost, Walter

1987-01-01

313

Support Routines for In Situ Image Processing  

Science.gov (United States)

This software consists of a set of application programs that support ground-based image processing for in situ missions. These programs represent a collection of utility routines that perform miscellaneous functions in the context of the ground data system. Each one fulfills some specific need as determined via operational experience. The most unique aspect to these programs is that they are integrated into the large, in situ image processing system via the PIG (Planetary Image Geometry) library. They work directly with space in situ data, understanding the appropriate image meta-data fields and updating them properly. The programs themselves are completely multimission; all mission dependencies are handled by PIG. This suite of programs consists of: (1)marscahv: Generates a linearized, epi-polar aligned image given a stereo pair of images. These images are optimized for 1-D stereo correlations, (2) marscheckcm: Compares the camera model in an image label with one derived via kinematics modeling on the ground, (3) marschkovl: Checks the overlaps between a list of images in order to determine which might be stereo pairs. This is useful for non-traditional stereo images like long-baseline or those from an articulating arm camera, (4) marscoordtrans: Translates mosaic coordinates from one form into another, (5) marsdispcompare: Checks a Left Right stereo disparity image against a Right Left disparity image to ensure they are consistent with each other, (6) marsdispwarp: Takes one image of a stereo pair and warps it through a disparity map to create a synthetic opposite- eye image. For example, a right eye image could be transformed to look like it was taken from the left eye via this program, (7) marsfidfinder: Finds fiducial markers in an image by projecting their approximate location and then using correlation to locate the markers to subpixel accuracy. These fiducial markets are small targets attached to the spacecraft surface. This helps verify, or improve, the pointing of in situ cameras, (8) marsinvrange: Inverse of marsrange . given a range file, re-computes an XYZ file that closely matches the original. . marsproj: Projects an XYZ coordinate through the camera model, and reports the line/sample coordinates of the point in the image, (9) marsprojfid: Given the output of marsfidfinder, projects the XYZ locations and compares them to the found locations, creating a report showing the fiducial errors in each image. marsrad: Radiometrically corrects an image, (10) marsrelabel: Updates coordinate system or camera model labels in an image, (11) marstiexyz: Given a stereo pair, allows the user to interactively pick a point in each image and reports the XYZ value corresponding to that pair of locations. marsunmosaic: Extracts a single frame from a mosaic, which will be created such that it could have been an input to the original mosaic. Useful for creating simulated input frames using different camera models than the original mosaic used, and (12) merinverter: Uses an inverse lookup table to convert 8-bit telemetered data to its 12-bit original form. Can be used in other missions despite the name.

Deen, Robert G.; Pariser, Oleg; Yeates, Matthew C.; Lee, Hyun H.; Lorre, Jean

2013-01-01

314

In situ soil remediation: Bacteria or fungi?  

Energy Technology Data Exchange (ETDEWEB)

Contamination of the environment is not a new problem. For most of recorded history, the unwanted byproducts of industrial and residential processes have been dumped into unlined pits or nearby streams. Although disposal techniques have greatly improved, significant quantities of hazardous materials are still being released to the environment via accidental spills and leaking underground storage tanks. One particular group of contaminants of critical environmental concern is polycyclic aromatic hydrocarbons (PAHs). PAH-contaminated sites typically cover large areas; therefore, the development of in situ remediation techniques such as bioremediation is strongly emphasized. In situations when inherent microorganisms are not capable of degrading the contaminants, foreign strains must be used. Bioremediation experiments were conducted to compare the remediation efficiencies of a bacteria and a fungus for an industrially PAH contaminated soil. Specifically, the use of three supplemental nutrient solutions were investigated in conjunction with the bacteria Achromobacter sp. and fungus Cunninghamella echinulata var. elegans.

Cutright, T.J.; Lee, S. [Univ. of Akron, OH (United States). Dept. of Chemical Engineering

1995-07-01

315

In situ soil remediation: Bacteria or fungi?  

International Nuclear Information System (INIS)

Contamination of the environment is not a new problem. For most of recorded history, the unwanted byproducts of industrial and residential processes have been dumped into unlined pits or nearby streams. Although disposal techniques have greatly improved, significant quantities of hazardous materials are still being released to the environment via accidental spills and leaking underground storage tanks. One particular group of contaminants of critical environmental concern is polycyclic aromatic hydrocarbons (PAHs). PAH-contaminated sites typically cover large areas; therefore, the development of in situ remediation techniques such as bioremediation is strongly emphasized. In situations when inherent microorganisms are not capable of degrading the contaminants, foreign strains must be used. Bioremediation experiments were conducted to compare the remediation efficiencies of a bacteria and a fungus for an industrially PAH contaminated soil. Specifically, the use of three supplemental nutrient solutions were investigated in conjunction with the bacteria Achromobacter sp. and fungus Cunninghamella echinulata var. elegans

316

PREPARATION OF NANOCOMPOSITES BY IN SITU POLIMERIZATION  

Scientific Electronic Library Online (English)

Full Text Available Polyethylene nanocomposites were obtained by in situ polymerization using both montmorillonite (natural clay) and montmorillonite organically modified with octadecylamine (O-Clo). In this proposed methodology the clays were added directly in the reactor together with the catalytic system (metallocen [...] e catalyst and methylaluminoxane) and ethylene. The nanocomposites were characterized by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and transmission electron microscopy (TEM), and by tensile stress-strain tests. It was found that the catalytic activity increased around 20% when natural clay was used compared with the standard polymer. But when modified clay was used the catalytic activity did not show important changes. On the other hand, XRD and TEM showed that the clays are in a disordered state and well dispersed in the polyethylene matrix. Finally, the nanocomposites showed an increase of about 30% in Young's modulus compared with the standard polymer

PAULA, ZAPATA; RAÚL, QUIJADA; JAIME, RETUER; EDWIN, MONCADA.

1359-13-01

317

In situ corrosion monitoring of steam generators  

International Nuclear Information System (INIS)

An ac electrochemical technique which meets the basic requirements for an in situ localized corrosion monitor within the secondary coolant of PWR steam generators has been investigated. The technique uses two electrodes to measure the electrochemical impedance of a surface in an occluded region with high heat flux. The impedance is related to the kinetics of corrosion. Marked decreases indicate the onset of a high corrosion rate. Experiments have demonstrated the ability of the technique to determine the onset of corrosion under conditions of high solution resistance and solution agitation due to local boiling. Experiments have shown the technique operates similarly in pressurized 3000C water, 1,400 ppM in Na2SO4

318

In situ erosion of cohesive sediment  

International Nuclear Information System (INIS)

There has been increasing interest in tidal power schemes and the effect of a tidal energy barrage on the environment. A large man-made environmental change, such as a barrage, would be expected to have significant effects on the sediment distribution and stability of an estuary and these effects need to be assessed when considering a tidal barrage project. This report describes the development of apparatus for in-situ measurements of cohesive sediment erosion on inter-tidal mudflats. Development of the prototype field erosion bell and field testing was commissioned on behalf of the Department of Trade and Industry by the Energy Technology Support Unit (ETSU). This later work commenced in August 1991 and was completed in September 1992. (Author)

319

In situ vitrification applications to hazardous wastes  

International Nuclear Information System (INIS)

In Situ Vitrification is a new hazardous waste remediation alternative that should be considered for contaminated soil matrices. According to the authors the advantages of using ISV include: technology demonstrated at field scale; applicable to a wide variety of soils and contaminants; pyrolyzer organics and encapsulates inorganics; product durable over geologic time period; no threat of harm to the public from exposure; and applications available for barrier walls and structural support. The use of ISV on a large scale basis has thus far been limited to the nuclear industry but has tremendous potential for widespread applications to the hazardous waste field. With the ever changing regulations for the disposal of hazardous waste in landfills, and the increasing positive analytical data of ISV, the process will become a powerful source for on-site treatment and hazardous waste management needs in the very near future

320

PERFORMANCE CONFIRMATION IN-SITU INSTRUMENTATION  

International Nuclear Information System (INIS)

The purpose of this document is to identify and analyze the types of in-situ instruments and methods that could be used in support of the data acquisition portion of the Performance Confirmation (PC) program at the potential nuclear waste repository at Yucca Mountain. The PC program will require geomechanical , geophysical, thermal, and hydrologic instrumentation of several kinds. This analysis is being prepared to document the technical issues associated with each type of measurement during the PC period. This analysis utilizes the ''Performance Confirmation Input Criteria'' (CRWMS M andO 1999a) as its starting point. The scope of this analysis is primarily on the period after the start of waste package emplacement and before permanent closure of the repository, a period lasting between 15 and 300 years after last package emplacement (Stroupe 2000, Attachment 1, p. 1). The primary objectives of this analysis are to: (1) Review the design criteria as presented in the ''Performance Confirmation Input Criteria'' (CRWMS M andO 1999a). The scope of this analysis will be limited to the instrumentation related to parameters that require continuous monitoring of the conditions underground. (2) Preliminary identification and listing of the data requirements and parameters as related to the current repository layout in support of PC monitoring. (3) Preliminary identification of methods and instrumentation for the acquisition of the required data. Although the ''Performance Confirmation Input Criteria'' (CRWMS M andO 1999a) defines a broad range of data that must be obtained from a variety of methods, the focus of this analysis is on instrumentation related to the performance of the rock mass and the formation of water in the repository environment, that is obtainable from in-situ observation, testing, and monitoring

321

In Situ Field Testing of Processes  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this Analysis/Model Report (AMR) is to update and document the data and subsequent analyses from ambient field-testing activities performed in underground drifts of the Yucca Mountain Site Characterization Project (YMP). This revision updates data and analyses presented in the initial issue of this AMR. This AMR was developed in accordance with the ''Technical Work Plan for Unsaturated Zone (UZ) Flow and Transport Process Model Report'' and ''Technical Work Plan for UZ Flow, Transport, and Coupled Processes Process Model Report. These activities were performed to investigate in situ flow and transport processes. The evaluations provide the necessary framework to: (1) refine and confirm the conceptual model of matrix and fracture processes in the unsaturated zone (UZ) and (2) analyze the impact of excavation (including use of construction water and effect of ventilation) on the UZ flow and transport processes. This AMR is intended to support revisions to ''Conceptual and Numerical Models for UZ Flow and Transport'' and ''Unsaturated Zone Flow and Transport Model Process Model Report''. In general, the results discussed in this AMR are from studies conducted using a combination or a subset of the following three approaches: (1) air-injection tests, (2) liquid-release tests, and (3) moisture monitoring using in-drift sensors or in-borehole sensors, to evaluate the impact of excavation, ventilation, and construction-water usage on the surrounding rocks. The liquid-release tests and air-injection tests provide an evaluation of in situ fracture flow and the competing processes of matrix imbibition. Only the findings from testing and data not covered in the ''Seepage Calibration Model and Seepage Testing Data'' are analyzed in detail in the AMR.

J. Wang

2001-12-14

322

In situ permeability testing of rock salt  

International Nuclear Information System (INIS)

Storage of transuranic (TRU) wastes in bedded salt formations requires a knowledge of the in situ permeability of SENM rock salt. Since assumptions for safety assessments have been made in which these wastes could generate gas pressures on the order of the lithostatic pressure over geologic time scales, the permeability of the surrounding formation becomes an important parameter for determining the manner in which the gases will be contained or dispersed. This report describes the series of tests conducted in the AEC-7 borehole, located near the WIPP site, to determine the in situ gas flow characteristics of the bedded salt. In these tests, compressed air was injected into the borehole and flow into the surrounding formation measured. These measured flow rates were interpreted in terms of formation permeabilities and porosities which were, in turn, used as modeling parameters for the repository response analysis. Two series of field tests were performed. The first series consisted of a number of whole-hole flow tests conducted to provide preliminary design information required for future operation of a guarded straddle packer system capable of measuring permeabilities > or = 0.1 ?darcy. The second series of tests were conducted using the Systems, Science and Software (S-Cubed) designed guarded straddle packer system. In these interval permeability tests, 100-foot lengths of borehole were isolated and the flow characteristics of the surrounding formation examined. In f the surrounding formation examined. In this report, a complete description of the test procedures, instrumentation, and measurement techniques is first given. The analytical/numerical methods used for data interpretation are then presented, followed by results of the interval and permeability tests. (The whole-hole tests are summarized in Appendix A.) Conclusions are presented in the final section

323

Melanoma "in situ" tratado con Imiquimod Melanoma in situ treated with Imiquimod  

Directory of Open Access Journals (Sweden)

Full Text Available Comunicamos un caso con dos melanomas "in situ", en un varón de 86 años, localizados en ambos lados de la cara con alto riesgo quirúrgico, quien fuera tratado con imiquimod al 5% una vez al día durante dos meses; los resultados hasta el momento, clínicos e histológicos han sido satisfactorios.A 86 years-old man with two melanomas "in situ" at both sides of his face, treated with imiquimod 5% are presented. The patient has a cardiovascular high risk due to isquemic heart disease, for that reason we start the treatment with imiquimod once a day for two months. The clinical and histological response was good and a follow up will be as long as we can.

RE Achenbach

324

Melanoma "in situ" tratado con Imiquimod / Melanoma in situ treated with Imiquimod  

Scientific Electronic Library Online (English)

Full Text Available Comunicamos un caso con dos melanomas "in situ", en un varón de 86 años, localizados en ambos lados de la cara con alto riesgo quirúrgico, quien fuera tratado con imiquimod al 5% una vez al día durante dos meses; los resultados hasta el momento, clínicos e histológicos han sido satisfactorios. [...] Abstract in english A 86 years-old man with two melanomas "in situ" at both sides of his face, treated with imiquimod 5% are presented. The patient has a cardiovascular high risk due to isquemic heart disease, for that reason we start the treatment with imiquimod once a day for two months. The clinical and histological [...] response was good and a follow up will be as long as we can.

RE, Achenbach; M, Dutto; S, Dupuy; CA, Maggi; C, Grecco; A, Acevedo; GF, Sánchez.

2012-12-30

325

Ion assisted deposition processes: in situ control; Ionengestuetzte Beschichtungsprozesse in situ kontrollieren  

Energy Technology Data Exchange (ETDEWEB)

Ion assisted deposition processes for optical precision components exhibit a high potential, in particular in the near and mid infrared spectral region. The presented results demonstrate the important criterion of a minimized water adsorption in the thin film structures by measurements of the optical losses in the wavelength range around 3 {mu}m as well as by the determination of the spectral stability of the optics. Furthermore, the employment of an in situ monitor, which allows wide-band transmission measurements directly at the product, provides an extensive database for the process analysis and development. Thus, additional information about the growth behavior, the vacuum-to-air-shift, and about layer inhomogeneities is available. The combination of the in situ monitor with the coating plant control results in an automated process system, which allows a precise determination of the layer thickness and represents a basis for the rapid prototyping of complex layer systems. In contrast to standard monitor strategies, test coatings and calibration factors are not necessary. With the presented combination of the stable ion assisted deposition process and the in situ monitor, the production of demanding NIR/MIR multilayer systems with high reproducibility could be automated. (orig.)

Ehlers, H.; Gross, T.; Lappschies, M.; Ristau, D. [Laser Zentrum Hannover e.V. (Germany). Abteilung Laserkomponeneten, Gruppe Prozessentwicklung

2004-12-01

326

Common In-Situ Consumable Production Plant for Robotic Mars Exploration  

Science.gov (United States)

Utilization of extraterrestrial resources, or In-Situ Resource Utilization (ISRU), is viewed by the Human Exploration and Development of Space (HEDS) Enterprise as an enabling technology for the exploration and commercial development of space. A key subset of ISRU which has significant cost, mass, and risk reduction benefits for robotic and human exploration, and which requires a minimum of infrastructure, is In-Situ Consumable Production (ISCP). ISCP involves acquiring, manufacturing, and storing mission consumables from in situ resources, such as propellants, fuel cell reagents, and gases for crew and life support, inflation, science and pneumatic equipment. One of the four long-term goals for the Space Science Enterprise (SSE) is to 'pursue space science programs that enable and are enabled by future human exploration beyond low-Earth orbit - a goal exploiting the synergy with the human exploration of space'. Adequate power and propulsion capabilities are critical for both robotic and human exploration missions. Minimizing the mass and volume of these systems can reduce mission cost or enhance the mission by enabling the incorporation of new science or mission-relevant equipment. Studies have shown that in-situ production of oxygen and methane propellants can enhance sample return missions by enabling larger samples to be returned to Earth or by performing Direct Earth Return (DER) sample return missions instead of requiring a Mars Orbit Rendezvous (MOR). Recent NASA and Department of Energy (DOE) work on oxygen and hydrocarbon-based fuel cell power systems shows the potential of using fuel cell power systems instead of solar arrays and batteries for future rovers and science equipment. The development and use of a common oxygen/methane ISCP plant for propulsion and power generation can extend and enhance the scientific exploration of Mars while supporting the development and demonstration of critical technologies and systems for the human exploration of Mars.

Sanders, G. B.; Trevathan, J. R.; Peters, T. A.; Baird, R. S.

2000-01-01

327

IN-SITU TRITIUM BETA DETECTOR  

International Nuclear Information System (INIS)

The objectives of this three-phase project were to design, develop, and demonstrate a monitoring system capable of detecting and quantifying tritium in situ in ground and surface waters, and in water from effluent lines prior to discharge into public waterways. The tritium detection system design is based on measurement of the low energy beta radiation from the radioactive decay of tritium using a special form of scintillating optical fiber directly in contact with the water to be measured. The system consists of the immersible sensor module containing the optical fiber, and an electronics package, connected by an umbilical cable. The system can be permanently installed for routine water monitoring in wells or process or effluent lines, or can be moved from one location to another for survey use. The electronics will read out tritium activity directly in units of pico Curies per liter, with straightforward calibration. In Phase 1 of the project, we characterized the sensitivity of fluor-doped plastic optical fiber to tritium beta radiation. In addition, we characterized the performance of photomultiplier tubes needed for the system. In parallel with this work, we defined the functional requirements, target specifications, and system configuration for an in situ tritium beta detector that would use the fluor-doped fibers as primary sensors of tritium concentration in water. The major conclusions from the characterization work are: A polystyrene optical fiber with fluor dopant concentration of 2% gave best performance. This fiber had the highest dopant concentration of any fibers tested. Stability may be a problem. The fibers exposed to a 22-day soak in 120 F water experienced a 10x reduction in sensitivity. It is not known whether this was due to the build up of a deposit (a potentially reversible effect) or an irreversible process such as leaching of the scintillating dye. Based on the results achieved, it is premature to initiate Phase 2 and commit to a prototype design for construction and test. Significant improvements must be made in fluor-doped fiber performance in order to use the method for in situ monitoring to verify compliance with current EPA drinking water standards. Additional Phase 1 fiber development work should be performed to increase the fluor dopant concentration above 2% until the self-absorption limit is observed. Continued fiber optimization work is expected to improve the sensitivity limits, and will enable application of the detector to verify compliance with the US EPA drinking water standard of 20,000 pico Curies per liter. However, if the need for monitoring higher levels of tritium in water at concentrations greater than 200,000 pico Curies per liter is justified, then prototype development and testing could proceed either as a Phase 2 stand-alone effort or in parallel with continued Phase 1 development work

328

IN-SITU TRITIUM BETA DETECTOR  

Energy Technology Data Exchange (ETDEWEB)

The objectives of this three-phase project were to design, develop, and demonstrate a monitoring system capable of detecting and quantifying tritium in situ in ground and surface waters, and in water from effluent lines prior to discharge into public waterways. The tritium detection system design is based on measurement of the low energy beta radiation from the radioactive decay of tritium using a special form of scintillating optical fiber directly in contact with the water to be measured. The system consists of the immersible sensor module containing the optical fiber, and an electronics package, connected by an umbilical cable. The system can be permanently installed for routine water monitoring in wells or process or effluent lines, or can be moved from one location to another for survey use. The electronics will read out tritium activity directly in units of pico Curies per liter, with straightforward calibration. In Phase 1 of the project, we characterized the sensitivity of fluor-doped plastic optical fiber to tritium beta radiation. In addition, we characterized the performance of photomultiplier tubes needed for the system. In parallel with this work, we defined the functional requirements, target specifications, and system configuration for an in situ tritium beta detector that would use the fluor-doped fibers as primary sensors of tritium concentration in water. The major conclusions from the characterization work are: A polystyrene optical fiber with fluor dopant concentration of 2% gave best performance. This fiber had the highest dopant concentration of any fibers tested. Stability may be a problem. The fibers exposed to a 22-day soak in 120 F water experienced a 10x reduction in sensitivity. It is not known whether this was due to the build up of a deposit (a potentially reversible effect) or an irreversible process such as leaching of the scintillating dye. Based on the results achieved, it is premature to initiate Phase 2 and commit to a prototype design for construction and test. Significant improvements must be made in fluor-doped fiber performance in order to use the method for in situ monitoring to verify compliance with current EPA drinking water standards. Additional Phase 1 fiber development work should be performed to increase the fluor dopant concentration above 2% until the self-absorption limit is observed. Continued fiber optimization work is expected to improve the sensitivity limits, and will enable application of the detector to verify compliance with the US EPA drinking water standard of 20,000 pico Curies per liter. However, if the need for monitoring higher levels of tritium in water at concentrations greater than 200,000 pico Curies per liter is justified, then prototype development and testing could proceed either as a Phase 2 stand-alone effort or in parallel with continued Phase 1 development work.

J.W. Berthold; L.A. Jeffers

1998-04-15

329

Some implications of in situ uranium mining technology development  

Energy Technology Data Exchange (ETDEWEB)

A technology assessment was initiated in March 1979 of the in-situ uranium mining technology. This report explores the impediments to development and deployment of this technology and evaluates the environmental impacts of a generic in-situ facility. The report is divided into the following sections: introduction, technology description, physical environment, institutional and socioeconomic environment, impact assessment, impediments, and conclusions. (DLC)

Cowan, C.E.; Parkhurst, M.A.; Cole, R.J.; Keller, D.; Mellinger, P.J.; Wallace, R.W.

1980-09-01

330

An overview of in situ waste treatment technologies  

International Nuclear Information System (INIS)

In situ technologies are becoming an attractive remedial alternative for eliminating environmental problems. In situ treatments typically reduce risks and costs associated with retrieving, packaging, and storing or disposing-waste and are generally preferred over ex situ treatments. Each in situ technology has specific applications, and, in order to provide the most economical and practical solution to a waste problem, these applications must be understood. This paper presents an overview of thirty different in situ remedial technologies for buried wastes or contaminated soil areas. The objective of this paper is to familiarize those involved in waste remediation activities with available and emerging in situ technologies so that they may consider these options in the remediation of hazardous and/or radioactive waste sites. Several types of in situ technologies are discussed, including biological treatments, containment technologies, physical/chemical treatments, solidification/stabilization technologies, and thermal treatments. Each category of in situ technology is briefly examined in this paper. Specific treatments belonging to these categories are also reviewed. Much of the information on in situ treatment technologies in this paper was obtained directly from vendors and universities and this information has not been verified

331

In-situ heat transfer experiment  

International Nuclear Information System (INIS)

Systems are being developed to measure the in-situ thermal conductivity of deep ocean sediment. The initial experiment plan was to implant a 400 watt isotope heat source into the sediment at MPG-I and monitor the thermal field around it at distances of up to 2 m for one year. The temperature data were to be recorded on a seabed platform along with photographs and vane shear values. Upon command, digital data in storage would be sent to the surface acoustically. At the end of the year, corers would be driven in by the platform to take samples of heat affected sediment. These were to be recovered along with the platform for laboratory analysis. Work was progressing well on the design of the various systems until mid-1980 when higher sediment shear strengths were estimated for in-situ MPG-I and more experiments for the platform were added. This report covers the major work performed by APL during 1980 for the ISHTE. The expanded scope of ISHTE has not affected the work performed on the designs discussed. Design of the platform and the control system will be affected the most; they have been delayed until next year, when more details on the add-on experiments will be available. The locational accuracy of the thermal probes and the predicted higher sediment shear strength have affected the development of the probes and their implantment mechanisms. This has prolonged the completion of their manufacture. The two major systems developed this year for ISHTE have been the acouped this year for ISHTE have been the acoustic tracking and data telemetry system and the hydrostatic sediment corer. Both systems are highly successful and are described in detail in this report. Another addition to the ISHTE program this year is an ISHTE simulation (ISIMU) to be performed in the Ocean Environment Chamber at NSRDC in Annapolis, Maryland, during October and November 1981. The purpose of this test is to look for unexpected phenomena in the heat affected sediment

332

Multimodal confocal mosaics enable high sensitivity and specificity in screening of in situ squamous cell carcinoma  

Science.gov (United States)

Screening cancer in excision margins with confocal microscopy may potentially save time and cost over the gold standard histopathology (H and E). However, diagnostic accuracy requires sufficient contrast and resolution to reveal pathological traits in a growing set of tumor types. Reflectance mode images structural details due to microscopic refractive index variation. Nuclear contrast with acridine orange fluorescence provides enhanced diagnostic value, but fails for in situ squamous cell carcinoma (SCC), where the cytoplasm is important to visualize. Combination of three modes [eosin (Eo) fluorescence, reflectance (R) and acridine orange (AO) fluorescence] enable imaging of cytoplasm, collagen and nuclei respectively. Toward rapid intra-operative pathological margin assessment to guide staged cancer excisions, multimodal confocal mosaics can image wide surgical margins (~1cm) with sub-cellular resolution and mimic the appearance of conventional H and E. Absorption contrast is achieved by alternating the excitation wavelength: 488nm (AO fluorescence) and 532nm (Eo fluorescence). Superposition and false-coloring of these modes mimics H and E, enabling detection of the carcinoma in situ in the epidermal layer The sum mosaic Eo+R is false-colored pink to mimic eosins' appearance in H and E, while the AO mosaic is false-colored purple to mimic hematoxylins' appearance in H and E. In this study, mosaics of 10 Mohs surgical excisions containing SCC in situ and 5 containing only normal tissue were subdivided for digital presentation equivalent to 4X histology. Of the total 16 SCC in situ multimodal mosaics and 16 normal cases presented, two reviewers made 1 and 2 (respectively) type-2 errors (false positives) but otherwise scored perfectly when using the confocal images to screen for the presence of SCC in situ as compared to the gold standard histopathology. Limitations to precisely mimic H and E included occasional elastin staining by AO. These results suggest that confocal mosaics may effectively guide staged SCC excisions in skin and other tissues.

Grados Luyando, Maria del Carmen; Bar, Anna; Snavely, Nicholas; Jacques, Steven; Gareau, Daniel S.

2014-02-01

333

Freshening in the South China Sea during 2012 revealed by Aquarius and in situ data  

Science.gov (United States)

Newly available sea surface salinity (SSS) data from the Aquarius together with in situ hydrographic data are used to explore the spatial and temporal characteristics of SSS in the South China Sea (SCS). Using in situ observations as the reference, an evaluation of daily Aquarius data indicates that there exists a negative bias of 0.45 psu for the version 3.0 data set. The root-mean-square difference for daily Aquarius SSS is about 0.53 psu after correcting the systematic bias, and those for weekly and monthly Aquarius SSSs are 0.45 and 0.29 psu, respectively. Nevertheless, the Aquarius SSS shows a reliable freshening in the SCS in 2012, which is larger than the Aquarius uncertainty. The freshening of up to 0.4 psu in the upper-ocean of the northern SCS was confirmed by in situ observations. This freshening in 2012 was caused by a combined effect of abundant local freshwater flux and limited Kuroshio intrusion. By comparing the Kuroshio intrusion in 2012 with that in 2011, we found the reduction as a relatively important cause for the freshening over the northern SCS. In contrast to the northern SCS, reduced river discharge in 2012 played the leading role to the saltier surface in the region near the Mekong River mouth with respect to 2011.

Zeng, Lili; Timothy Liu, W.; Xue, Huijie; Xiu, Peng; Wang, Dongxiao

2014-12-01

334

A NOVEL OPHTHALMIC DRUG DELIVERY SYSTEM: IN-SITU GEL  

Directory of Open Access Journals (Sweden)

Full Text Available The ophthalmic in-situ gels now days proved an palpable sustained drug delivery in various eye diseases. The formulation of in-situ gels for eye which carries the advantages like easy for administration, reduces frequency of dose and improves patient compliance. The formation of in-situ gels depends on phase transition system or sol-gel transition system. The formulation approaches like temperature intonation, pH change and presence of ions from which the drug gets released in a sustained and controlled manner are utilised for in-situ gels. Various polymers that are used for the formulation of in-situ gels include chitosan, Pluronic F-127, poly-caprolactone, gellan gum, alginic acid, xyloglucan, pectin etc.

A.P. Patil*, A.A. Tagalpallewar, G.M. Rasve, A.V. Bendre, P.G. Khapekar

2012-09-01

335

Aluminum-Based Cast In Situ Composites: A Review  

Science.gov (United States)

In situ composites are a class of composite materials in which the reinforcement is formed within the matrix by reaction during the processing. In situ method of composite synthesis has been widely followed by researchers because of several advantages over conventional stir casting such as fine particle size, clean interface, and good wettability of the reinforcement with the matrix and homogeneous distribution of the reinforcement compared to other processes. Besides this, in situ processing of composites by casting route is also economical and amenable for large scale production as compared to other methods such as powder metallurgy and spray forming. Commonly used reinforcements for Al and its alloys which can be produced in situ are Al2O3, AlN, TiB2, TiC, ZrB2, and Mg2Si. The aim of this paper is to review the current research and development in aluminum-based in situ composites by casting route.

Pramod, S. L.; Bakshi, Srinivasa R.; Murty, B. S.

2015-02-01

336

Fractionation of stable isotopes in perchlorate and nitrate during in situ biodegradation in a sandy aquifer  

Science.gov (United States)

Environmental context. Perchlorate (ClO4-) and nitrate (NO3-) are common co-contaminants in groundwater, with both natural and anthropogenic sources. Each of these compounds is biodegradable, so in situ enhanced bioremediation is one alternative for treating them in groundwater. Because bacteria typically fractionate isotopes during biodegradation, stable isotope analysis is increasingly used to distinguish this process from transport or mixing-related decreases in contaminant concentrations. However, for this technique to be useful in the field to monitor bioremediation progress, isotope fractionation must be quantified under relevant environmental conditions. In the present study, we quantify the apparent in situ fractionation effects for stable isotopes in ClO4- (Cl and O) and NO3- (N and O) resulting from biodegradation in an aquifer. Abstract. An in situ experiment was performed in a shallow alluvial aquifer in Maryland to quantify the fractionation of stable isotopes in perchlorate (Cl and O) and nitrate (N and O) during biodegradation. An emulsified soybean oil substrate that was previously injected into this aquifer provided the electron donor necessary for biological perchlorate reduction and denitrification. During the field experiment, groundwater extracted from an upgradient well was pumped into an injection well located within the in situ oil barrier, and then groundwater samples were withdrawn for the next 30 h. After correction for dilution (using Br- as a conservative tracer of the injectate), perchlorate concentrations decreased by 78% and nitrate concentrations decreased by 82% during the initial 8.6 h after the injection. The observed ratio of fractionation effects of O and Cl isotopes in perchlorate (18O/37Cl) was 2.6, which is similar to that observed in the laboratory using pure cultures (2.5). Denitrification by indigenous bacteria fractionated O and N isotopes in nitrate at a ratio of ???0.8 (18O/15N), which is within the range of values reported previously for denitrification. However, the magnitudes of the individual apparent in situ isotope fractionation effects for perchlorate and nitrate were appreciably smaller than those reported in homogeneous closed systems (0.2 to 0.6 times), even after adjustment for dilution. These results indicate that (1) isotope fractionation factor ratios (18O/37Cl, 18O/15N) derived from homogeneous laboratory systems (e.g. pure culture studies) can be used qualitatively to confirm the occurrence of in situ biodegradation of both perchlorate and nitrate, but (2) the magnitudes of the individual apparent values cannot be used quantitatively to estimate the in situ extent of biodegradation of either anion. ?? CSIRO 2009.

Hatzinger, P.B.; Böhlke, J.K.; Sturchio, N.C.; Gu, B.; Heraty, L.J.; Borden, R.C.

2009-01-01

337

Preparation and thermal properties of mesoporous silica/phenolic resin nanocomposites via in situ polymerization  

Directory of Open Access Journals (Sweden)

Full Text Available In order to enhance the adhesion between inorganic particles and polymer matrix, in this paper, the mesoporous silica SBA-15 material was synthesized by the sol-gel method. The surface of SBA-15 was modified using ?-glycidyloxypropyltrimethoxysilane (GOTMS as a coupling agent, and then mesoporous silica/phenolic resin (SBA-15/PF nanocomposites were prepared via in situ polymerization. The structural parameters and physical properties of SBA-15, SBA-15-GOTMS (SBA-15 surface treated using GOTMS as coupling agents and E-SBA-15/PF (SBA-15/PF nanocomposites extracted using ethanol as solvent were characterized by X-ray diffraction (XRD, N2 adsorption-desorption, Fourier transform infrared spectroscopy (FTIR, scanning electron microscopy (SEM, transmission electron microscopy (TEM and thermogravimetric analysis (TGA. The thermal properties of the nanocomposites were studied by differential scanning calorimetry (DSC and thermogravimetric analysis (TGA. The results demonstrated that the GOTMS were successfully grafted onto the surface of SBA-15, and chemical bonds between PF and SBA-15-GOTMS were formed after in situ polymerization. In addition, it is found that the in situ polymerization method has great effects on the textural parameters of SBA-15. The results also showed that the glass transition temperatures and thermal stability of the PF nanocomposites were obviously enhanced as compared with the pure PF at silica contents between 1–3 wt%, due to the uniform dispersion of the modified SBA-15 in the matrix.

J. Lv

2012-10-01

338

In-situ electrochemical route to aerogel electrode materials of graphene and hexagonal CeO?.  

Science.gov (United States)

We reported a one-step in-situ electrochemical route to synthesize 3D aerogel electrode materials including graphene and hexagonal CeO2 composites. The graphene/CeO2 aerogel can be formed via freeze-drying graphene/CeO2 colloidal solution that was obtained by electrochemical exfoliation of graphite anode and in-situ deposition of CeO2 nanoparticles on graphene sheets in mixing electrolyte of (NH4)2SO4/Ce(NO3)3 and (NH4)2SO4/(NH4)2Ce(NO3)6. The as-obtained CeO2 nanoparticles were closely contacted with graphene, which can enhance the synergistic effect between graphene and CeO2. It is interesting that the as-obtained CeO2 products possessed hexagonal crystal structure that was rarely reported. The Faradaic reactivity of the graphene/CeO2 composites as supercapacitor was enhanced with the increase of the concentration of Ce salts in initial electrolyte. The introduction of CeO2 to graphene electrode can lead to the presence of additional pseudocapacitance besides the electric double-layer capacitance. This simple one-step in-situ electrochemical route can be extended to synthesize various graphene/metal oxide aerogel electrode materials for electric energy storage. PMID:25660707

Chen, Kunfeng; Xue, Dongfeng

2015-05-15

339

In-situ Rb-Sr geochronology  

Science.gov (United States)

This paper reports on the first rubidium-strontium (Rb-Sr) radiometric dates using a Laser Desorption Resonance Ionization Mass Spectrometry (LDRIMS) instrument capable of being miniaturized for flight to another planet. The LDRIMS instrument produces dates in under 24 hours, requires minimal sample preparation, and avoids the interference and mass resolution issues associated with other geochronology measurements. We have begun testing the bench-top prototype on the Boulder Creek Granite (BCG), from Colorado, comprised primarily of a gneissic quartz monzonite and granodiorite; whole rock Rb-Sr TIMS measurements result in dates of 1700± 40 Ma [1]. Data reduction of the LDRIMS Rb-Sr measurements on calibrated repeat runs result in a date for the BCG of 1.727± 0.087 Ga (n=288, MSWD=1). Most geochronology applications are willing to accept an MSWD up to ~2.7; at MSWD=2, the precision improves to ± 0.062 Ga. This technology is moving from lab prototype to field deployable instrument, and provides an opportunity to directly address the science goals of Mars Sample Return (MSR) within the bounds posed by current scientific, fiscal, and political pressures on the Mars program. Additionally, LDRIMS could potentially be flown to the Moon under the Discovery or New Frontiers program. We posit that in-situ geochronology missions to Mars to triage and validate samples for Mars Sample Return (MSR) are technically feasible in the 2018-2022 time frame.

Anderson, F. S.; Nowicki, K.; Whitaker, T.

340

In situ readable ultrasonic seal system  

International Nuclear Information System (INIS)

The in situ readable ultrasonic seal system (IRUSS) provides the IAEA with a comprehensive system for safeguarding nuclear materials using underwater ultrasonic seals. IRUSS enables the IAEA to both maintain and manage a central database containing the inventory of nuclear material under safeguards and all associated sealing information, and to produce the necessary pre- and post-inspection reports and data files. Another component of IRUSS provides IAEA inspectors at spent fuel storage facilities with a convenient tool for acquiring seal signatures of newly installed ultrasonic seals and for reverifying previously installed seals. IRUSS currently meets the requirements of the AECL random coil seals used in CANDU facilities, and of MK4-R sealing bolts, developed by Euratom, Joint Research Centre, Ispra, Italy, which are presently used for sealing multi-element bottles used in European facilities. The paper describes major features of IRUSS and presents benefits of this comprehensive instrument for supporting nuclear safeguards through the application of underwater ultrasonic seals. (author). 5 refs, 4 figs

341

In-situ combustion with solvent injection  

Energy Technology Data Exchange (ETDEWEB)

The effects of combining in situ combustion and heavy hydrocarbon naphtha vapor injection techniques in a heavy oil reservoir were investigated. Oil production rates and steam injection efficiencies were considered. The technique was also combined with toe-to-heel air injection (THAI) processes. The study showed that the modified THAI process achieved high rates of recovery for both primary production and as a follow-up technique in partially depleted reservoirs after cyclic steam and cold production. Oil produced using the modified THAI technique was also partially upgraded by the process. Results of the vapour chamber pressure calculations showed that the volume of oil produced by naphtha assisted gravity drainage was between 1 to 3 times higher than amounts of oil produced by SAGD processes during the same amount of time. The naphtha injection process produced more oil than the steam only process. However, high amounts of naphtha were needed to produce oil. Injection and production rates during the naphtha injection process were higher. Naphtha vapor was injected near the heel of a horizontal producer well. The vapor acted as a thermal and diluent mechanism in order to reduce the viscosity of the heavy oil . 9 refs., 4 tabs., 6 figs.

D' Silva, J.; Kakade, G. [Society of Petroleum Engineers, Kuala Lumpur (Malaysia)]|[Maharashtra Inst. of Technology, Pune (India)

2008-10-15

342

Photonic MEMS for NIR in-situ  

Energy Technology Data Exchange (ETDEWEB)

We report on a novel sensing technique combining photonics and microelectromechanical systems (MEMS) for the detection and monitoring of gas emissions for critical environmental, medical, and industrial applications. We discuss how MEMS-tunable vertical-cavity surface-emitting lasers (VCSELs) can be exploited for in-situ detection and NIR spectroscopy of several gases, such as O{sub 2}, N{sub 2}O, CO{sub x}, CH{sub 4}, HF, HCl, etc., with estimated sensitivities between 0.1 and 20 ppm on footprints {approx}10{sup -3} mm{sup 3}. The VCSELs can be electrostatically tuned with a continuous wavelength shift up to 20 nm, allowing for unambiguous NIR signature determination. Selective concentration analysis in heterogeneous gas compositions is enabled, thus paving the way to an integrated optical platform for multiplexed gas identification by bandgap and device engineering. We will discuss here, in particular, our efforts on the development of a 760 nm AlGaAs based tunable VCSEL for O{sub 2} detection.

Bond, T C; Cole, G D; Goddard, L L; Behymer, E

2007-07-03

343

In situ vitrification of radioactive underground tanks  

International Nuclear Information System (INIS)

In situ vitrification (ISV) is a treatment process with great potential for remediating underground tanks previously used for storing radioactive and hazardous chemical wastes at US Department of Energy (DOE) sites. Tests at several scales have demonstrated the utility of ISV for these tanks. An engineering-scale test vitrified a 30-cm-diameter buried steel and concrete tank that contained simulated tank sludge. Hazardous components of the tank sludge were immobilized, or removed and captured in the off-gas treatment system, and the tank walls were melted or incorporated into the ISV block. A pilot-scale ISV test vitrified a 1-m simulated underground tank than contained a simulated refractory sludge. The ISV process completely vitrified the tank, its contents, and the soil below the tank to a depth of 2.4 m, producing a uniform glass and crystalline monolith with an estimated mass of 30 tons. A large-scale underground tank test is scheduled for early 1991. 5 refs., 4 figs

344

Innovative technologies for in-situ remediation  

International Nuclear Information System (INIS)

LLNL is developing several innovative remediation technologies as long-term improvements to the current pump and treat approaches to cleaning up contaminated soils and groundwater. These technologies include dynamic underground stripping, in-situ microbial filters, and remediation using bremsstrahlung radiation. Concentrated underground organic contaminant plumes are one of the most prevalent groundwater contamination sources. The solvent or fuel can percolate deep into the earth, often into water-bearing regions. Collecting as a separate, liquid organic phase called dense non-aqueous-phase liquids (DNAPLs), or light NAPLs (LNAPLs), these contaminants provide a source term that continuously compromises surrounding groundwater. This type of spill is one of the most difficult environmental problems to remediate. Attempts to remove such material requires a huge amount of water which must be washed through the system to clean it, requiring decades. Traditional pump and treat approaches have not been successful. LLNL has developed several innovative technologies to clean up NAPL contamination. Detailed descriptions of these technologies are given

345

IN-SITU MINING OF PHOSPHATE ORES  

Energy Technology Data Exchange (ETDEWEB)

Presently the mining of Florida phosphate requires the movement of over a 100-ton of materials (overburden, sand, clay) for every ton of phosphate concentrate recovered. Not only is this energy intensive, but it also causes significant stress on the environment. In 2003, the Department of Energy solicited ideas for innovative mining ideas that could significantly improve the efficiency of mining. An award was made to the University of Florida Engineering Research Center to evaluate the in situ mining of phosphates using an aqueous CO{sub 2} solution. Tests were carried out in a 15.2 cm (6-inch) diameter column, 1.83 meter (6 feet) long at pressures up to 117.2 kg/cm{sup 2} (40 psi). Results to date demonstrate that initially the MgO is leached from the ore and then the phosphate. While the tests are continuing, so far they have not demonstrated P{sub 2}O{sub 5} concentrations that are economically attractive.

H. El-Shall; R. Stana; A. El-Midany; S. Malekzadah

2004-12-17

346

Innovative technologies for in-situ remediation  

Energy Technology Data Exchange (ETDEWEB)

LLNL is developing several innovative remediation technologies as long-term improvements to the current pump and treat approaches to cleaning up contaminated soils and groundwater. These technologies include dynamic underground stripping, in-situ microbial filters, and remediation using bremsstrahlung radiation. Concentrated underground organic contaminant plumes are one of the most prevalent groundwater contamination sources. The solvent or fuel can percolate deep into the earth, often into water-bearing regions. Collecting as a separate, liquid organic phase called dense non-aqueous-phase liquids (DNAPLs), or light NAPLs (LNAPLs), these contaminants provide a source term that continuously compromises surrounding groundwater. This type of spill is one of the most difficult environmental problems to remediate. Attempts to remove such material requires a huge amount of water which must be washed through the system to clean it, requiring decades. Traditional pump and treat approaches have not been successful. LLNL has developed several innovative technologies to clean up NAPL contamination. Detailed descriptions of these technologies are given.

Ragaini, R.; Aines, R.; Knapp, R.; Matthews, S.; Yow, J.

1994-06-01

347

DNA fragmentation in microorganisms assessed in situ.  

Science.gov (United States)

Chromosomal DNA fragmentation may be a direct or indirect outcome of cell death. Unlike DNA fragmentation in higher eukaryotic cells, DNA fragmentation in microorganisms is rarely studied. We report an adaptation of a diffusion-based assay, developed as a kit, which allows for simple and rapid discrimination of bacteria with fragmented DNA. Intact cells were embedded in an agarose microgel on a slide, incubated in a lysis buffer to partially remove the cell walls, membranes, and proteins, and then stained with a DNA fluorochrome, SYBR Gold. Identifying cells with fragmented DNA uses peripheral diffusion of DNA fragments. Cells without DNA fragmentation show only limited spreading of DNA fiber loops. These results have been seen in several gram-negative and gram-positive bacteria, as well as in yeasts. Detection of DNA fragmentation was confirmed by fluoroquinolone treatment and by DNA breakage detection-fluorescence in situ hybridization. Proteus mirabilis with spontaneously fragmented DNA during exponential and stationary growth or Escherichia coli with DNA damaged after exposure to hydrogen peroxide or antibiotics, such as ciprofloxacin or ampicillin, was clearly detected. Similarly, fragmented DNA was detected in Saccharomyces cerevisiae after amphotericin B treatment. Our assay may be useful for the simple and rapid evaluation of DNA damage and repair as well as cell death, either spontaneous or induced by exogenous stimuli, including antimicrobial agents or environmental conditions. PMID:18689511

Fernández, José Luis; Cartelle, Mónica; Muriel, Lourdes; Santiso, Rebeca; Tamayo, María; Goyanes, Vicente; Gosálvez, Jaime; Bou, Germán

2008-10-01

348

DNA Fragmentation in Microorganisms Assessed In Situ?  

Science.gov (United States)

Chromosomal DNA fragmentation may be a direct or indirect outcome of cell death. Unlike DNA fragmentation in higher eukaryotic cells, DNA fragmentation in microorganisms is rarely studied. We report an adaptation of a diffusion-based assay, developed as a kit, which allows for simple and rapid discrimination of bacteria with fragmented DNA. Intact cells were embedded in an agarose microgel on a slide, incubated in a lysis buffer to partially remove the cell walls, membranes, and proteins, and then stained with a DNA fluorochrome, SYBR Gold. Identifying cells with fragmented DNA uses peripheral diffusion of DNA fragments. Cells without DNA fragmentation show only limited spreading of DNA fiber loops. These results have been seen in several gram-negative and gram-positive bacteria, as well as in yeasts. Detection of DNA fragmentation was confirmed by fluoroquinolone treatment and by DNA breakage detection-fluorescence in situ hybridization. Proteus mirabilis with spontaneously fragmented DNA during exponential and stationary growth or Escherichia coli with DNA damaged after exposure to hydrogen peroxide or antibiotics, such as ciprofloxacin or ampicillin, was clearly detected. Similarly, fragmented DNA was detected in Saccharomyces cerevisiae after amphotericin B treatment. Our assay may be useful for the simple and rapid evaluation of DNA damage and repair as well as cell death, either spontaneous or induced by exogenous stimuli, including antimicrobial agents or environmental conditions. PMID:18689511

Fernández, José Luis; Cartelle, Mónica; Muriel, Lourdes; Santiso, Rebeca; Tamayo, María; Goyanes, Vicente; Gosálvez, Jaime; Bou, Germán

2008-01-01

349

In situ observations of Io torus plasma  

International Nuclear Information System (INIS)

The physical properties of the Io plasma formation deduced from in situ observations are described. The torus plasma is characterized by spatially distinct regions with steep gradients in plasma parameters between them. The innermost region has a cool plasma which collapses toward the centrifugal equator and gives rise to a distinctive localized concentration of plasma well inside of Io's orbit. The next region has a warm plasma which includes the L-shell of Io and is the presumed injection region of the plasma. Other regions, known as the plasma ledge and ramp, are described. The changes in plasma characteristics are accounted for by centrifugally driven flux tube interchange diffusion to provide radial mass transport. The ramp is shown to result from impoundment of the plasma by the inner edge of the energetic particle population. It is also shown how the power required to excite the ultraviolet emissions of the torus and the Jovian aurora determines the rate at which new plasma is fed into the torus

350

In situ observations of Io torus plasma  

Science.gov (United States)

The physical properties of the Io plasma formation deduced from in situ observations are described. The torus plasma is characterized by spatially distinct regions with steep gradients in plasma parameters between them. The innermost region has a cool plasma which collapses toward the centrifugal equator and gives rise to a distinctive localized concentration of plasma well inside of Io's orbit. The next region has a warm plasma which includes the L-shell of Io and is the presumed injection region of the plasma. Other regions, known as the plasma ledge and ramp, are described. The changes in plasma characteristics are accounted for by centrifugally driven flux tube interchange diffusion to provide radial mass transport. The ramp is shown to result from impoundment of the plasma by the inner edge of the energetic particle population. It is also shown how the power required to excite the ultraviolet emissions of the torus and the Jovian aurora determines the rate at which new plasma is fed into the torus.

Sullivan, J. D.; Siscoe, G. L.

1982-01-01

351

In situ microscopic analysis of asbestos and synthetic vitreous fibers retained in hamster lungs following inhalation.  

Science.gov (United States)

Hamsters breathed, nose-only, for 13 weeks, 5 days/week, 6 hr/day, either man-made vitreous fiber (MMVF)10a, MMVF33, or long amosite asbestos at approximately 300 World Health Organization (WHO) fibers/cc or long amosite at 25 WHO fibers/cc. [World Health Organization fibers are longer than 5 microm and thicker than 3 microm, with aspect ratio >3.] After sacrifice, fiber burden was estimated (left lungs) by ashing and scanning electron microscopy (ashing/SEM) or (right middle lobes) by confocal laser scanning microscopy (CLSM) in situ. In situ CLSM also provided three-dimensional views of fibers retained, undisturbed, in lung tissue. Fibers of each type were lodged in alveoli and small airways, especially at airway bifurcations, and were seen fully or partly engulfed by alveolar macrophages. Amosite fibers penetrated into and through alveolar septa. Length densities of fibers in parenchyma (total length of fiber per unit volume of lung) were estimated stereologically from fiber transsections counted on two-dimensional optical sections and were 30.5, 25.3, 20.0, and 81.6 mm/mm3 for MMVF10a, MMVF33, and low- and high-dose amosite, respectively. Lengths of individual fibers were measured in three dimensions by tracking individual fibers through series of optical sections. Length distributions of amosite fibers aerosolized, but before inhalation versus after retention in the lung were similar, whether determined by ashing/SEM or in situ CLSM. In contrast, the fraction of short MMVF10a and MMVF33 fibers increased and the geometric mean fiber lengths of both MMVFs decreased by approximately 60% during retention. Most likely due to fiber deposition pattern and differences in sampling, fiber burdens [MMVF10a, MMVF33, and amosite (high dose; 269 WHO fibers/cc)] determined by ashing/SEM were 1.4, 1. 5, and 3.5 times greater, respectively, than those calculated from in situ CLSM data. In situ CLSM is able to provide detailed information about the anatomic sites of fiber retention and also fiber lengths and burdens in good agreement with ashing/SEM results. PMID:10210692

Rogers, R A; Antonini, J M; Brismar, H; Lai, J; Hesterberg, T W; Oldmixon, E H; Thevenaz, P; Brain, J D

1999-05-01

352

Comparing in situ removal strategies for improving styrene bioproduction.  

Science.gov (United States)

As an important conventional monomer compound, the biological production of styrene carries significant promise with respect to creating novel sustainable materials. Since end-product toxicity presently limits styrene production by previously engineered Escherichia coli, in situ product removal by both solvent extraction and gas stripping were explored as process-based strategies for circumventing its inhibitory effects. In solvent extraction, the addition of bis(2-ethylhexyl)phthalate offered the greatest productivity enhancement, allowing net volumetric production of 836 ± 64 mg/L to be reached, representing a 320 % improvement over single-phase cultures. Gas stripping rates, meanwhile, were controlled by rates of bioreactor agitation and, to a greater extent, aeration. A periodic gas stripping protocol ultimately enabled up to 561 ± 15 mg/L styrene to be attained. Lastly, by relieving the effects of styrene toxicity, new insight was gained regarding subsequent factors limiting its biosynthesis in E. coli and strategies for future strain improvement are discussed. PMID:25034182

McKenna, Rebekah; Moya, Luis; McDaniel, Matthew; Nielsen, David R

2015-01-01

353

In situ electrical measurements of polytypic silver nanowires.  

Science.gov (United States)

Novel 4H structure silver nanowires (4H-AgNWs) have been reported to coexist with the usual face-centered cubic (FCC) ones. Here we report the electrical properties of these polytypic AgNWs for the first time. AgNWs with either 4H or FCC structures in the diameter range of 20-80 nm were measured in situ inside a transmission electron microscope (TEM). Both kinds of AgNW in the diameter range show metallic conductance. The average resistivity of the 4H-AgNWs is 19.9 ?? cm, comparable to the 11.9 ?? cm of the FCC-AgNWs. The failure current density can be up to ?10(8) A cm(-2) for both 4H-and FCC-AgNWs. The maximum stable current density (MSCD) is introduced to estimate the AgNWs' current-carrying ability, which shows diameter-dependence with a peak around 34 nm in diameter. It is attributed to fast annihilation of the current-induced vacancies and the enhanced surface scattering. Our investigations also suggest that the magnetic field of the electromagnetic lens may also introduce some influence on the measurements inside the TEM. PMID:21730742

Liu, Xiaohua; Zhu, Jing; Jin, Chuanhong; Peng, Lian-Mao; Tang, Daiming; Cheng, Huiming

2008-02-27

354

In situ electrical measurements of polytypic silver nanowires  

International Nuclear Information System (INIS)

Novel 4H structure silver nanowires (4H-AgNWs) have been reported to coexist with the usual face-centered cubic (FCC) ones. Here we report the electrical properties of these polytypic AgNWs for the first time. AgNWs with either 4H or FCC structures in the diameter range of 20-80 nm were measured in situ inside a transmission electron microscope (TEM). Both kinds of AgNW in the diameter range show metallic conductance. The average resistivity of the 4H-AgNWs is 19.9 ?? cm, comparable to the 11.9 ?? cm of the FCC-AgNWs. The failure current density can be up to ?108 A cm-2 for both 4H-and FCC-AgNWs. The maximum stable current density (MSCD) is introduced to estimate the AgNWs' current-carrying ability, which shows diameter-dependence with a peak around 34 nm in diameter. It is attributed to fast annihilation of the current-induced vacancies and the enhanced surface scattering. Our investigations also suggest that the magnetic field of the electromagnetic lens may also introduce some influence on the measurements inside the TEM

355

In-situ air sparging under confined aquifer conditions  

International Nuclear Information System (INIS)

In the summer of 1993, an effort to evaluate the effectiveness of in-situ air sparging (IAS) and soil vapor extraction (SVE) to remedy jet fuel condition found in Colorado River Terrace deposits was initiated by the Air Force Center for Environmental Excellence. Preliminary field tests were performed to develop air injection flow rates, IAS radius of influence, air entry pressure requirements, SVE radii of influence, SVE well head vacuum requirements, and SVE air extraction flow rates. In addition to the field tests, soil samples were, collected for formal geotechnical laboratory analysis. The information gathered from these preliminary field investigations were then used to design and install a pilot scale ground-water remediation system. The pilot scale system represents a modified version of the traditional IAS/SVE approach. Due to the presence of an overlying low permeability confining layer, the system was modified to inject and extract air from the phreatic zone. The vapor extraction wells are screened down into the saturated interval to provide an escape route for the air injected by the sparging system. This system is intended to trigger two remedial processes. The first is the physical stripping of dissolved phase volatile petroleum constituents as ground water contacts air channels forming around each sparge point. The second remedial process which may be activated by this system is enhanced aerobic biodegradation of organics due to the oxygenation of the sa organics due to the oxygenation of the saturated interval

356

In-situ Characterization of Cast Stainless Steel Microstructures  

International Nuclear Information System (INIS)

Cast austenitic stainless steel (CASS) that was commonly used in U.S. nuclear power plants is a coarse-grained, elastically anisotropic material. The engineering properties of CASS made it a material of choice for selected designs of nuclear power reactor systems. However, the fabrication processes result in a variety of coarse-grain microstructures that are difficult to inspect ultrasonically, largely due to detrimental effects of wave interactions with the microstructure. To address the inspection needs, new approaches that are robust to these phenomena are being sought. However, overcoming the deleterious effects of the coarse-grained microstructure on the interrogating ultrasonic beam will require knowledge of the microstructure and the corresponding acoustic properties of the material, for potential optimization of inspection parameters to enhance the probability of detecting flaws. The goal of improving the reliability and effectiveness of ultrasonic inspection of CASS specimens can therefore potentially be achieved by first characterizing the microstructure of the component. The characterization of CASS microstructure must be done in-situ, to enable dynamic selection and optimization of the ultrasonic inspection technique. This paper discusses the application of ultrasonic measurement methods for classifying the microstructure of CASS components, when making measurements from the outside surface of the pipe or component. Results to date demonstrate the potentia. Results to date demonstrate the potential of ultrasonic and electromagnetic measurements to classify the material type of CASS for two consistent microstructures-equiaxed-grain material and columnar-grain material.

357

In Situ TEM Observation of Dislocation Evolutionin Polycrystalline UO2  

Energy Technology Data Exchange (ETDEWEB)

In situ transmission electron microscopy observation of polycrystalline UO2 (with average grain size of about 5 lm) irradiated with Kr ions at 600C and 800C was conducted to understand the radiation-induced dislocation evolution under the influence of grain boundaries. The dislocation evolution in the grain interior of polycrystalline UO2 was similar under Kr irradiation at different ion energies and temperatures. As expected, it was characterized by the nucleation and growth of dislocation loops at low irradiation doses, followed by transformation to extended dislocation lines and tangles at high doses. For the first time, a dislocation-denuded zone was observed near a grain boundary in the 1-MeV Kr-irradiated UO2 sample at 800C. The denuded zone in the vicinity of grain boundary was not found when the irradiation temperature was at 600C. The suppression of dislocation loop formation near the boundary is likely due to the enhanced interstitial diffusion toward grain boundary at the high temperature.

L. F. HE; 1 M. A. KIRK; Argonne National Laboratory; J. Gan; T. R. ALLEN

2014-10-01

358

In situ vadose zone remediation of petroleum-contaminated soils  

International Nuclear Information System (INIS)

This paper discusses a pilot-scale system treating vadose zone soils contaminated with petroleum products constructed and operated at a former petroleum bulk storage terminal in New England. A site investigation following decommissioning activities identified more than 100,000 yds of soil at the site contaminated by both No. 2 fuel oil and gasoline. Soil cleanup criteria of 50 ppm TPH and 0.25 ppm BTEX were established. A pilot-scale treatment unit with dimensions of 125 ft x 125 ft x 6 ft was constructed to evaluate the potential for in situ treatment of vadose zone soils. Contaminant levels in pilot cell soils ranged from 0 to 5,250 ppm TPH and 0.0 to 4.2 ppm BTEX. Two soil treatment methods n the pilot system were implemented; venting to treat the lighter petroleum fractions and bioremediation to treat the nonvolatile petroleum constituents. Seven soil gas probes were installed to monitor pressure and soil gas vapor concentrations in the subsurface. Changes in soil gas oxygen and carbon dioxide concentrations were used as an indirect measure of enhanced bioremediation of pilot cell soils. After operating the system for a period of 2.5 months, soil BTEX concentrations were reduced to concentrations below the remediation criteria for the site

359

In situ treatment of VOCs by recirculation technologies  

Energy Technology Data Exchange (ETDEWEB)

The project described herein was conducted by Oak Ridge National Laboratory (ORNL) to identify processes and technologies developed in Germany that appeared to have near-term potential for enhancing the cleanup of volatile organic compound (VOC) contaminated soil and groundwater at DOE sites. Members of the ORNL research team identified and evaluated selected German technologies developed at or in association with the University of Karlsruhe (UoK) for in situ treatment of VOC contaminated soils and groundwater. Project activities included contacts with researchers within three departments of the UoK (i.e., Applied Geology, Hydromechanics, and Soil and Foundation Engineering) during fall 1991 and subsequent visits to UoK and private industry collaborators during February 1992. Subsequent analyses consisted of engineering computations, groundwater flow modeling, and treatment process modeling. As a result of these project efforts, two processes were identified as having near-term potential for DOE: (1) the vacuum vaporizer well/groundwater recirculation well and (2) the porous pipe/horizontal well. This document was prepared to summarize the methods and results of the assessment activities completed during the initial year of the project. The project is still ongoing, so not all facets of the effort are completely described in this document. Recommendations for laboratory and field experiments are provided.

Siegrist, R.L.; Webb, O.F.; Ally, M.R.; Sanford, W.E. [Oak Ridge National Lab., TN (US); Kearl, P.M.; Zutman, J.L. [Oak Ridge National Lab., Grand Junction, CO (US)

1993-06-01

360

In situ recycling of contaminated soil uses bioremediation  

International Nuclear Information System (INIS)

OxyChem Pipeline Operations, primarily an ethylene and propylene products mover, has determined that substantial savings can be realized by adopting a bioremediation maintenance and recycling approach to hydrocarbon-contaminated soil. By this method, the soil can be recycled in situ, or in containers. To implement the soil-recycling program, OxyChem elected to use a soil remediator and natural absorbent product, Oil Snapper. This field maintenance material, based on an Enhanced Urea Technology, provides a diet to stimulate the growth of hydrocarbon-eating microbes. It works well either with indigenous soil microbes or with commercial microbes. The product is carried in field vehicles, which makes it immediately available when leaks or spills are discovered. Procedure for clean-up is to apply product and mix it into affected soil. Thus the contaminant is contained, preventing further migration; the contaminant is dispersed throughout the product, making it more accessible to the microbes; nutrients are immediately available to the microbes; and the material contributes aeration and moisture-retention properties

361

In situ signatures of residual plasmaspheric plumes: Observations and simulation  

Science.gov (United States)

We compare in situ observations of the Los Alamos National Laboratory (LANL) Magnetospheric Plasma Analyzers with output of a dynamic, plasmapause test particle (PTP) simulation for the moderately disturbed interval 18-20 January 2000. In the model, weakly enhanced convection on 18 January creates a narrow drainage plume (plume A) that wraps completely around the main torus. Moderate convection on 19 January triggers significant plasmaspheric erosion, forming a second plume (B) that coexists with the narrow, wrapped, residual plume A. We fly three virtual LANL satellites through the simulation domain. The observations are globally consistent with the PTP simulation; LANL data contain several intervals of plume plasma in the model's predicted magnetic local time (MLT) sector. The modeled durations of plume sector transits are in good agreement with the LANL data. On a subglobal scale, the MLT widths and timings of the simulated plumes do not precisely agree with observations. However, several observation intervals exhibit good morphological agreement with virtual spacecraft signatures of two distinct, coexisting plumes (A and B). The fine-scale structure in the PTP model arises from the merging of residual plume A with the newer plume B. Plume merging is one theoretical means of generating fine structure in the plasmasphere: during multiple cycles of erosion and recovery, successive layers of wrapped, residual plumes can merge with newer plumes, creating layers of filamentary density structure. The model-data comparisons suggest that the plasmaspheric density distribution may preserve some memory of prior epochs of erosion and recovery.

Goldstein, J.; Thomsen, M. F.; DeJong, A.

2014-06-01

362

In situ forming, metal-adhesive heparin hydrogel surfaces for blood-compatible coating.  

Science.gov (United States)

Durable and blood-compatible coating of metallic biomaterials remains a major issue in biomedical fields despite its long history of development. In this study, in situ forming, metal-adhesive heparin hydrogels were developed to coat metallic substrates to enhance blood compatibility. The hydrogels are composed of metal-adhesive and enzyme-reactive amphiphilic block copolymer (Tetronic-tyramine/dopamine; TTD) and enzyme-reactive heparin derivatives (heparin-tyramine or heparin-polyethylene glycol-tyramine), which are cross-linkable in situ via an enzyme reaction. The combinations of heparin and Tetronic formed hydrogels with relatively high mechanical strengths of 300-5000 Pa within several tens of seconds; this was also confirmed by observing a dried porous structure as coated on a metal surface. The introduction of dopamine to the hydrogel network enhanced the durability of the hydrogel layers coated on metal, such that more than 60% heparin remained for 7 days. Compared to bare metal surfaces, hydrogel-coated metal surfaces exhibited significantly enhanced blood compatibility. Reduced fibrinogen adsorption and platelet adhesion showed that blood compatibility was 3-5-fold-enhanced on coated hydrogel layers than on the bare metal surface. In conclusion, hydrogels containing heparin and dopamine prepared by enzyme reaction have the potential to be an alternative coating method for enhancing blood compatibility of metallic biomaterials. PMID:22100384

Joung, Yoon Ki; You, Seung Soo; Park, Kyung Min; Go, Dong Hyun; Park, Ki Dong

2012-11-01

363

Development of an rRNA-targeted oligonucleotide probe specific for the genus Acinetobacter and its application for in situ monitoring in activated sludge.  

OpenAIRE

Enhanced biological phosphate removal in an anaerobic-aerobic activated sludge system has generally been ascribed to members of the genus Acinetobacter. A genus-specific 16S rRNA-targeted oligonucleotide probe was developed to investigate the role of Acinetobacter spp. in situ. Nonisotopic dot blot hybridization to 66 reference strains, including the seven described Acinetobacter spp., demonstrated the expected probe specificity. Fluorescent derivatives were used for in situ monitoring of Aci...

Wagner, M.; Erhart, R.; Manz, W.; Amann, R.; Lemmer, H.; Wedi, D.; Schleifer, K. H.

1994-01-01

364

Genetic relation of lobular carcinoma in situ, ductal carcinoma in situ, and associated invasive carcinoma of the breast  

OpenAIRE

Aims—The mutual relation of lobular carcinoma in situ (LCIS) and ductal carcinoma in situ (DCIS) of the breast, as accepted precursor lesions of invasive breast cancer, is controversial. Because they display genetic heterogeneity, it is not clear how genetically advanced these entities are and what causes the transition to an invasive carcinoma.

Buerger, H.; Simon, R.; Scha?fer, K-l; Diallo, R.; Littmann, R.; Poremba, C.; Diest, P. J.; Dockhorn-dworniczak, B.; Bo?cker, W.

2000-01-01

365

60Co ?-irradiation enhances expression of GAP-43 mRNA in rat brain  

International Nuclear Information System (INIS)

Objective: To study the relationship between the expression of GAP-43 mRNA and nerve regeneration in rat brain after 60Co ?-irradiation. Methods: Wistar rats were subjected to whole-body irradiation with 8 Gy 60Co ?-rays. The expression of GAP-43 was detected by in situ hybridization histochemistry using Dig-cRNA probe. Results: It was found that the expression of GAP-43 mRNA increased in the cerebral cortex, caudate, putamen, globus pallidum, thalamus and hypothalamus one week after 8 Gy 60Co ?-irradiation. The peak of GAP-43 mRNA expression was observed in the fourth week and then began to decrease but still remained at a higher than normal level. However, it decreased to a low level after 7 weeks. Conclusion: Enhanced expression of GAP-43 mRNA after 60Co ?-irradiation in rat brain is associated with nerve regeneration and reconstruction of synapse

366

SUSTAIN OPHTHALMIC DELIVERY OF LEVOFLOXACIN FROM A pH -TRIGGERED IN SITU GELLING SYSTEM  

Directory of Open Access Journals (Sweden)

Full Text Available Most eye diseases are treated with topical application of eye drops. The poor bioavailability and therapeutic response exhibited by these conventional eye drops due to rapid precorneal elimination of the drug may be overcome by the use of in situ gelling systems that are instilled as drops into the eye and undergo a sol-to-gel transition in the cul-de-sac. Hence, the purpose of the present work was to develop Sustain Ophthalmic delivery of Levofloxacin from a pH-triggered in situ gelling system. Polyacrylic acid (Carbopol 934 was used as the gelling agent in combination with hydroxypropyl methylcellulose (Methocel K4M and HPMC K100LV which acted as a viscosity enhancing agent. Compatibility studies of the drug excipients were carried out using FTIR. The prepared formulations were characterized for clarity, pH, drug content, Gelling capacity, Rheological studies, in vitro drug release study, sterility study and stability study.

Asija Rajesh

2012-04-01

367

Orientation relationship in WC-Co composite nanoparticles synthesized by in situ reactions  

Science.gov (United States)

Using the nanoscale violet tungsten oxide as the tungsten source, the WC-Co composite powder was synthesized by the in situ reactions. The particle size of the WC-Co composite powder has a narrow distribution with the mean particle size below 100 nm, and the single composite particle has a nanocrystalline structure with a mean grain size smaller than 10 nm. The detailed characterizations of the nanoparticle microstructure reveal that the orientation relationship and coherence at the interfaces can form during the in situ reactions and further inherit in the consolidated cemented carbide bulk material. The favorable crystallographic characteristics of the WC-Co composite nanoparticles play a significant role in the enhancement of the mechanical properties of the prepared cemented carbide bulk material.

Wang, Xilong; Song, Xiaoyan; Liu, Xuemei; Liu, Xingwei; Wang, Haibin; Zhou, Cheng

2015-04-01

368

In situ studies of radiation induced crystallization in Fe/a-Y2O3 nanolayers  

Science.gov (United States)

Oxide dispersion strengthened ferritic alloys have superior radiation tolerance and thus become appealing candidates as fuel cladding materials for next generation nuclear reactors. In this study we constructed a model system, Fe/Y2O3 nanolayers with individual layer thicknesses of 10 and 50 nm, in order to understand their radiation response and corresponding damage mitigation mechanisms. These nanolayers were subjected to in situ Kr ion irradiation at room temperature up to ?8 displacements-per-atom. As-deposited Y2O3 layers had primarily amorphous structure. Radiation induced prominent nanocrystallization and grain growth in 50 nm thick Y2O3 layers. Conversely, little crystallization occurred in 10 nm thick Y2O3 layers implying size dependent enhancement of radiation tolerance. In situ video also captured grain growth in both Fe and Y2O3 and outstanding morphological stability of layer interfaces against Kr ion irradiation.

Chen, Y.; Jiao, L.; Sun, C.; Song, M.; Yu, K. Y.; Liu, Y.; Kirk, M.; Li, M.; Wang, H.; Zhang, X.

2014-09-01

369

Demonstration, testing, and evaluation of in situ heating of soil. Volume 1, Final report  

Energy Technology Data Exchange (ETDEWEB)

This document is a final reports in two volumes. Volume I contains the technical report and Volume II contains appendices with background information and data. In this project approximately 300 cubic yards of clayey soil containing a low concentration plume of volatile organic chemicals was heated in situ by the application of electrical energy. It was shown that as a result of heating the effective permeability of soil to air flow was increased such that in situ soil vapor extraction could be performed. The initial permeability of soil was so low that the soil gas flow rate was immeasurably small even at high vacuum levels. It was demonstrated that the mass flow rate of the volatile organic chemicals was enhanced in the recovered soil gas as a result of heating.

Dev, H.; Enk, J.; Jones, D.; Sabato, W.

1996-04-05

370

Demonstration, testing, and evaluation of in situ heating of soil. Volume 1, Final report  

International Nuclear Information System (INIS)

This document is a final reports in two volumes. Volume I contains the technical report and Volume II contains appendices with background information and data. In this project approximately 300 cubic yards of clayey soil containing a low concentration plume of volatile organic chemicals was heated in situ by the application of electrical energy. It was shown that as a result of heating the effective permeability of soil to air flow was increased such that in situ soil vapor extraction could be performed. The initial permeability of soil was so low that the soil gas flow rate was immeasurably small even at high vacuum levels. It was demonstrated that the mass flow rate of the volatile organic chemicals was enhanced in the recovered soil gas as a result of heating

371

In-situ microcosms, a tool for assessment of pesticide impacts on oyster spat (Crassostrea gigas).  

Science.gov (United States)

Effects of the herbicide Basamaïs (bentazon) and the fungicide Opus (epoxiconazole) on oyster spat (Crassostrea gigas) were assessed using in-situ microcosms in a field experiment lasting 13 days. Six-week-old hatchery spat (mean size 1.1 mm), previously collected on PVC plates, was immersed in glass bottles filled with 200 mum filtered seawater. Bottles were maintained underwater at 6 m depth and their water content changed every other day. Growth, measured as shell area index increase, was 126 +/- 4% in the control bottles. While no growth differences were observed between control and individual pesticide treatments at 10 microg l(-1), oysters treated with a mix of 10 microg l(-1) Opus and 10 microg l(-1) Basamaïs showed a 50% growth reduction compared with the control (P < 0.0001), suggesting a synergistic effect of these contaminants. Laboratory controls in microcosms maintained in a water bath with filtered natural light, were not significantly different from in-situ microcosm controls in the field, for organic weight content or growth. This in-situ experiment in microcosms allowed us to conclude that: (1) oyster spat can achieve significant growth in bottles immersed in situ without supplementary food; (2) this microcosm system is reliable and easy to use for environmental toxicity tests with C. gigas spat; (3) such microcosm systems can also be run in a laboratory water bath instead of more technically difficult immersed field experiments; (4) the synergistic effect observed here, at a concentration simulating a peak agricultural runoff event, suggests that the impacts of pesticides could be a real threat for oysters in estuarine areas. PMID:18236155

Stachowski-Haberkorn, Sabine; Quiniou, Françoise; Nedelec, Morgane; Robert, René; Limon, Gwendolina; de la Broise, Denis

2008-05-01

372

Virtual Savannah : In Situ Test of a Virtual Learning 3D Visualization for children  

DEFF Research Database (Denmark)

Virtual Savannah is constructed to visualize parts of a curriculum, which the educational service at Aalborg Zoo has difficulties in teaching children visiting the zoo. It contains rich media like audio, text, video and picture galleries about African ecology, but some of this episodic information has been visualized to a further extent in order to transfer it as semantic knowledge for the children to assimilate. Three in situ tests reflected through a set of assignments which prior knowledge the children had on the subject, if they could assimilate information from the system, and finally the children’s retention one week after the test, measuring if any learning had happened. The tests showed significant results by comparing prior knowledge with assimilated knowledge. It also showed significant results by comparing prior knowledge and knowledge retained one week after the test, which indicate that the children were not only able to use the system as intended, but they also learned from it.

Rodil, Kasper; Eskildsen, SØren

2012-01-01

373

Detection of denitrification genes by in situ rolling circle amplification - fluorescence in situ hybridization (in situ RCA-FISH) to link metabolic potential with identity inside bacterial cells  

DEFF Research Database (Denmark)

A target-primed in situ rolling circle amplification (in situ RCA) protocol was developed for detection of single-copy genes inside bacterial cells and optimized with Pseudomonas stutzeri, targeting nitrite and nitrous oxide reductase genes (nirS and nosZ). Two padlock probes were designed per gene to target both DNA strands; the target DNA was cut by a restriction endonuclease close to the probe binding sites, which subsequently were made accessible by 5'-3' exonucleolysis. After hybridization, the padlock probe was circularized by ligation and served as template for in situ RCA, primed by the probe target site. Finally, the RCA product inside the cells was detected by standard fluorescence in situ hybridization (FISH). The optimized protocol showed high specificity and signal-to-noise ratio but low detection frequency (up to 15% for single-copy genes and up to 43% for the multi-copy 16S rRNA gene). Nevertheless, multiple genes (nirS and nosZ; nirS and the 16S rRNA gene) could be detected simultaneously in P. stutzeri. Environmental application of in situ RCA-FISH was demonstrated on activated sludge by the differential detection of two types of nirS-defined denitrifiers; one of them was identified as Candidatus Accumulibacter phosphatis by combining in situ RCA-FISH with 16S rRNA-targeted FISH. While not suitable for quantification because of its low detection frequency, in situ RCA-FISH will allow to link metabolic potential with 16S rRNA (gene)-based identification of single microbial cells.

Hoshino, Tatsuhiko; Schramm, Andreas

2010-01-01

374

Environmental monitoring with in-situ gamma spectrometer; Umweltueberwachung mit in-situ-Gamma-Spektrometer  

Energy Technology Data Exchange (ETDEWEB)

The in-situ gamma spectroscopy allows large area and continuous monitoring of the radio nuclides and there composition in the environment. In comparison to the gamma dose rate measurement the additional spectral information gives the possibility for a quick and effective action in the case of a man-made radiation exposition in the environment. The knowledge respectively localization of the possible nuclides, which a responsible for the increased dose rate, supports responsible organization in the quick identification of the situation, definition of the actions and tracking of the temporal and local process of the radiation exposition. Due to dedicate actions the risk for people and environment is reduced.

Reinhardt, S. [ENVINET GmbH, Haar (Germany)

2014-01-20

375

National Wildlife Week 2002  

Science.gov (United States)

April 7-13, 2002, is Canada's National Wildlife Week. The week, a tribute to conservation pioneer Jack Miner, is an opportunity for citizens to "celebrate wildlife and take action to protect wild plants and animals." In addition to a calendar of events across Canada, the celebration's home page features 20 things that anyone can do to protect wildlife, as well as games, activities, and fact sheets focused on this year's theme -- Climate Change.

376

In Situ Probe Science at Saturn  

Science.gov (United States)

A fundamental goal of solar system exploration is to understand the origin of the solar system, the initial stages, conditions, and processes by which the solar system formed, how the formation process was initiated, and the nature of the interstellar seed material from which the solar system was born. Key to understanding solar system formation and subsequent dynamical and chemical evolution is the origin and evolution of the giant planets and their atmospheres. Several theories have been put forward to explain the process of solar system formation, and the origin and evolution of the giant planets and their atmospheres. Each theory offers quantifiable predictions of the abundances of noble gases He, Ne, Ar, Kr, and Xe, and abundances of key isotopic ratios 4He/3He, D/H, 15N/14N, 18O/16O, and 13C/12C. Detection of certain disequilibrium species, diagnostic of deeper internal processes and dynamics of the atmosphere, would also help discriminate between competing theories. Many of the key atmospheric constituents needed to discriminate between alternative theories of giant planet formation and chemical evolution are either spectrally inactive or primarily located in the deeper atmosphere inaccessible to remote sensing from Earth, flyby, or orbiting spacecraft. Abundance measurements of these key constituents, including the two major molecular carriers of carbon, methane and carbon monoxide (neither of which condense in Saturn's atmosphere), sulfur which is expected to be well-mixed below the 4 to 5-bar ammonium hydrosulfide (NH4SH) cloud, and gradients of nitrogen below the NH4SH cloud and oxygen in the upper layers of the H2O and H2O-NH4 solution cloud, must be made in situ and can only be achieved by an entry probe descending through 10 bars. Measurements of the critical abundance profiles of these key constituents into the deeper well-mixed atmosphere must be complemented by measurements of the profiles of atmospheric structure and dynamics at high vertical resolution that also require in situ exploration. The atmospheres of the giant planets can also serve as laboratories to better understand the atmospheric chemistries, dynamics, processes, and climates on all planets in the solar system including Earth, and offer a context and provide a ground truth for exoplanets and exoplanetary systems. Additionally, Giant planets have long been thought to play a critical role in the development of potentially habitable planetary systems. In the context of giant planet science provided by the Galileo, Juno, and Cassini missions to Jupiter and Saturn, a small, relatively shallow Saturn probe capable of measuring abundances and isotopic ratios of key atmospheric constituents, and atmospheric structure including pressures, temperatures, dynamics, and cloud locations and properties not accessible by remote sensing can serve to test competing theories of solar system and giant planet origin, chemical, and dynamical evolution. Acknowledgements This research was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2013 California Institute of Technology. U.S. Government sponsorship acknowledged. O. Mousis acknowledges support from CNES.

Atkinson, David H.; Lunine, Jonathan I.; Simon-Miller, Amy A.; Atreya, Sushil K.; Brinckerhoff, William B.; Colaprete, Anthony; Coustenis, Athena; Fletcher, Leigh N.; Guillot, Tristan; Lebreton, Jean-Pierre; Mahaffy, Paul; Mousis, Olivier; Orton, Glenn S.; Reh, Kim; Spilker, Linda J.; Spilker, Thomas R.; Webster, Chris R.

2014-05-01

377

In Situ Hydrocarbon Degradation by Indigenous Nearshore Bacterial Populations  

Energy Technology Data Exchange (ETDEWEB)

Potential episodic hydrocarbon inputs associated with oil mining and transportation together with chronic introduction of hydrocarbons via urban runoff into the relatively pristine coastal Florida waters poses a significant threat to Florida's fragile marine environment. It is therefore important to understand the extent to which indigenous bacterial populations are able to degrade hydrocarbon compounds and also determine factors that could potentially control and promote the rate at which these compounds are broken down in situ. Previous controlled laboratory experiments carried out by our research group demonstrated that separately both photo-oxidation and cometabolism stimulate bacterial hydrocarbon degradation by natural bacterial assemblages collected from a chronically petroleum contaminated site in Bayboro Bay, Florida. Additionally, we also demonstrated that stable carbon and radiocarbon abundances of respired CO{sub 2} could be used to trace in situ hydrocarbon degradation by indigenous bacterial populations at this same site. This current proposal had two main objectives: (a) to evaluate the cumulative impact of cometabolism and photo-oxidation on hydrocarbon degradation by natural bacterial assemblages collected the same site in Bayboro Bay, Florida and (b) to determine if in situ hydrocarbon degradation by indigenous bacterial populations this site could be traced using natural radiocarbon and stable carbon abundances of assimilated bacterial carbon. Funds were used for 2 years of full support for one ESI Ph.D. student, April Croxton. To address our first objective a series of closed system bacterial incubations were carried out using photo-oxidized petroleum and pinfish (i.e. cometabolite). Bacterial production of CO{sub 2} was used as the indicator of hydrocarbon degradation and {delta}{sup 13}C analysis of the resultant CO{sub 2} was used to evaluate the source of the respired CO{sub 2} (i.e. petroleum hydrocarbons or the pinfish cometabolite). Results from these time series experiments demonstrated that short-term exposure of petroleum to UV light enhanced hydrocarbon degradation by 48% over that observed for non-photo-oxidized petroleum. Despite the greater bio-availability of the photo-oxidized over the non-photo-oxidized petroleum, an initial lag in CO{sub 2} production was observed indicating potential phototoxicity of the photo- by-products. {delta}{sup 13}C analysis and mass balance calculations reveal that co-metabolism with pinfish resulted in increased hydrocarbon degradation for both photo-oxidized and non-photo-oxidized petroleum each by over 100%. These results demonstrate the cumulative effect of photo-oxidation and co-metabolism on petroleum hydrocarbon degradation by natural bacterial populations indigenous to systems chronically impacted by hydrocarbon input. To address the second objective of this proposal bacterial concentrates were collected from Bayboro Harbor in April 2001 for nucleic acid extraction and subsequent natural radiocarbon abundance analyses. Unfortunately, however, all of these samples were lost due to a faulty compressor in our -70 freezer. The freezer was subsequently repaired and samples were again collected from Bayboro Harbor in June 2002 and again December 2002. Several attempts were made to extract the nucleic acid samples--however, the student was not able to successfully extract and an adequate amount of uncontaminated nucleic acid samples for subsequent natural radiocarbon abundance measurements of the bacterial carbon by accelerator mass spectrometry (i.e. require at least 50 {micro}g carbon for AMS measurement). Consequently, we were not able to address the second objective of this proposed work.

Cherrier, J.

2005-05-16

378

In Situ Hydrocarbon Degradation by Indigenous Nearshore Bacterial Populations  

International Nuclear Information System (INIS)

Potential episodic hydrocarbon inputs associated with oil mining and transportation together with chronic introduction of hydrocarbons via urban runoff into the relatively pristine coastal Florida waters poses a significant threat to Florida's fragile marine environment. It is therefore important to understand the extent to which indigenous bacterial populations are able to degrade hydrocarbon compounds and also determine factors that could potentially control and promote the rate at which these compounds are broken down in situ. Previous controlled laboratory experiments carried out by our research group demonstrated that separately both photo-oxidation and cometabolism stimulate bacterial hydrocarbon degradation by natural bacterial assemblages collected from a chronically petroleum contaminated site in Bayboro Bay, Florida. Additionally, we also demonstrated that stable carbon and radiocarbon abundances of respired CO2 could be used to trace in situ hydrocarbon degradation by indigenous bacterial populations at this same site. This current proposal had two main objectives: (a) to evaluate the cumulative impact of cometabolism and photo-oxidation on hydrocarbon degradation by natural bacterial assemblages collected the same site in Bayboro Bay, Florida and (b) to determine if in situ hydrocarbon degradation by indigenous bacterial populations this site could be traced using natural radiocarbon and stable carbon abundances of assimilated bacterial carbon. Funds were used for 2 years of full support for one ESI Ph.D. student, April Croxton. To address our first objective a series of closed system bacterial incubations were carried out using photo-oxidized petroleum and pinfish (i.e. cometabolite). Bacterial production of CO2 was used as the indicator of hydrocarbon degradation and (delta)13C analysis of the resultant CO2 was used to evaluate the source of the respired CO2 (i.e. petroleum hydrocarbons or the pinfish cometabolite). Results from these time series experiments demonstrated that short-term exposure of petroleum to UV light enhanced hydrocarbon degradation by 48% over that observed for non-photo-oxidized petroleum. Despite the greater bio-availability of the photo-oxidized over the non-photo-oxidized petroleum, an initial lag in CO2 production was observed indicating potential phototoxicity of the photo- by-products. (delta)13C analysis and mass balance calculations reveal that co-metabolism with pinfish resulted in increased hydrocarbon degradation for both photo-oxidized and non-photo-oxidized petroleum each by over 100%. These results demonstrate the cumulative effect of photo-oxidation and co-metabolism on petroleum hydrocarbon degradation by natural bacterial populations indigenous to systems chronically impacted by hydrocarbon input. To address the second objective of this proposal bacterial concentrates were collected from Bayboro Harbor in April 2001 for nucleic acid extraction and subsequent natural radiocarbon abundance analyses. Unfortunately, however, all of these samples were lost due to a faulty compressor in our -70 freezer. The freezer was subsequently repaired and samples were again collected from Bayboro Harbor in June 2002 and again December 2002. Several attempts were made to extract the nucleic acid samples--however, the student was not able to successfully extract and an adequate amount of uncontaminated nucleic acid samples for subsequent natural radiocarbon abundance measurements of the bacterial carbon by accelerator mass spectrometry (i.e. require at least 50 (micro)g carbon for AMS measurement). Consequently, we were not able to address the second objective of this proposed work

379

In-situ chemical oxidation of MTBE  

Energy Technology Data Exchange (ETDEWEB)

In-situ chemical oxidation (ISCO) can be a cost-effective method for the destruction of source areas of methyl tertiary butyl ether (MTBE). Several ISCO processes have been tested successfully under laboratory conditions and a few have proven successful when field tested for the destruction of MTBE. This paper reviews the state of the art with respect to MTBE oxidation for several common oxidants and Advanced Oxidation Processes (AOPs). Four frequently used oxidants are reviewed in this paper: hydrogen peroxide (H{sub 2}O{sub 2}), ozone (O{sub 3}), permanganate (MnO{sub 4}{sup -} ), and persulfate (S{sub 2}O{sub 8}{sup 2-} ). When choosing an oxidant for a specific remediation strategy, trade-offs exist between oxidant strength and stability in the subsurface. Aquifer and water quality parameters such as pH, alkalinity, and soil oxidant demand (SOD) may influence the initiation and effectiveness of the ISCO reaction and may significantly increase the amount of oxidant required to treat the target contaminant. Oxidation end products are an important consideration in the selection of an oxidant, as not all oxidants have proven successful in complete mineralization of MTBE. Tert-butyl formate (TBF) and tert-butyl alcohol (TBA) are the major intermediate products in the oxidative reactions of MTBE and may pose a greater health hazard than MTBE. Other factors, including regulatory restrictions, need to be considered when choosing an oxidant for a specific application. This paper will highlight the chemistry of the oxidant/MTBE reactions, successes or limitations observed under laboratory and field conditions, and practical design advice when employing the oxidant. (author)

Kelley, K.L.; Marley, M.C.; Sperry, K.L. [XDD-LLC (United States)

2002-06-15

380

subjected to novel in-situ treatments  

Directory of Open Access Journals (Sweden)

Full Text Available Novedosos tratamientos fueron realizados in-situ a superficies de GaAs (100 con el propósito de obtener una mayor uniformidad en los tamaños de los puntos cuánticos (QDs autoensamblados de InAs. Los tratamientos consistieron en exponer las superficies de GaAs a temperatura alta por 10 segundos con el obturador de As4 cerrado. En un primer experimento la superficie de GaAs únicamente se mantuvo a 650±C sin ningún flujo, mientras que en el otro crecimiento el obturador de Si se abrió durante la interrupción del flujo de As4. Ambos experimentos se compararon con una muestra crecida convencionalmente. Notables diferencias fueron observadas en la cinética de crecimiento cuando el depósito de InAs se realizó sobre las diferentes superficies tratadas de GaAs. El tratamiento térmico realizado sin flujo de Si extiende a mucho mayor espesor la transición del crecimiento bidimensional a tridimensional de InAs. Por el contrario, la muestra tratada con Si mostró más tempana relajación de red comparada con la muestra de referencia. Respecto a la topología final de las muestras, ambos tratamientos redujeron la dispersión en alturas y diámetros, respecto a la muestra crecida convencionalmente. Por lo tanto, un significativo mejoramiento fue inducido por los tratamientos térmicos en la distribución de tamaños de los QDs, lo cual a su vez redujo el ancho medio (FWHM de los espectros de fotoluminiscencia (PL. Además, los experimentos de PL mostraron una clara correlación entre el aumento en los tamaños de los puntos y el corrimiento hacia el rojo del pico de emisión que se observó para los QDs crecidos sobre las superficies de GaAs sometidas a los diferentes tratamientos.

V. H. M\\u00E9ndez-Garc\\u00EDa

2005-01-01

381

In-Situ Wire Damage Detection System  

Science.gov (United States)

An In-Situ Wire Damage Detection System (ISWDDS) has been developed that is capable of detecting damage to a wire insulation, or a wire conductor, or to both. The system will allow for realtime, continuous monitoring of wiring health/integrity and reduce the number of false negatives and false positives while being smaller, lighter in weight, and more robust than current systems. The technology allows for improved safety and significant reduction in maintenance hours for aircraft, space vehicles, satellites, and other critical high-performance wiring systems for industries such as energy production and mining. The integrated ISWDDS is comprised of two main components: (1) a wire with an innermost core conductor, an inner insulation film, a conductive layer or inherently conductive polymer (ICP) covering the inner insulation film, an outermost insulation jacket; and (2) smart connectors and electronics capable of producing and detecting electronic signals, and a central processing unit (CPU) for data collection and analysis. The wire is constructed by applying the inner insulation films to the conductor, followed by the outer insulation jacket. The conductive layer or ICP is on the outer surface of the inner insulation film. One or more wires are connected to the CPU using the smart connectors, and up to 64 wires can be monitored in real-time. The ISWDDS uses time domain reflectometry for damage detection. A fast-risetime pulse is injected into either the core conductor or conductive layer and referenced against the other conductor, producing transmission line behavior. If either conductor is damaged, then the signal is reflected. By knowing the speed of propagation of the pulse, and the time it takes to reflect, one can calculate the distance to and location of the damage.

Williams, Martha; Roberson, Luke; Tate, Lanetra; Smith, Trent; Gibson, Tracy; Medelius, Pedro; Jolley, Scott

2012-01-01

382

In-situ chemical oxidation of MTBE  

International Nuclear Information System (INIS)

In-situ chemical oxidation (ISCO) can be a cost-effective method for the destruction of source areas of methyl tertiary butyl ether (MTBE). Several ISCO processes have been tested successfully under laboratory conditions and a few have proven successful when field tested for the destruction of MTBE. This paper reviews the state of the art with respect to MTBE oxidation for several common oxidants and Advanced Oxidation Processes (AOPs). Four frequently used oxidants are reviewed in this paper: hydrogen peroxide (H2O2), ozone (O3), permanganate (MnO4- ), and persulfate (S2O82- ). When choosing an oxidant for a specific remediation strategy, trade-offs exist between oxidant strength and stability in the subsurface. Aquifer and water quality parameters such as pH, alkalinity, and soil oxidant demand (SOD) may influence the initiation and effectiveness of the ISCO reaction and may significantly increase the amount of oxidant required to treat the target contaminant. Oxidation end products are an important consideration in the selection of an oxidant, as not all oxidants have proven successful in complete mineralization of MTBE. Tert-butyl formate (TBF) and tert-butyl alcohol (TBA) are the major intermediate products in the oxidative reactions of MTBE and may pose a greater health hazard than MTBE. Other factors, including regulatory restrictions, need to be considered when choosing an s, need to be considered when choosing an oxidant for a specific application. This paper will highlight the chemistry of the oxidant/MTBE reactions, successes or limitations observed under laboratory and field conditions, and practical design advice when employing the oxidant. (author)

383

In situ electron beam irradiated rapid growth of bismuth nanoparticles in bismuth-based glass dielectrics at room temperature  

Energy Technology Data Exchange (ETDEWEB)

In this study, in situ control growth of bismuth nanoparticles (Bi{sup 0} NPs) was demonstrated in bismuth-based glass dielectrics under an electron beam (EB) irradiation at room temperature. The effects of EB irradiation were investigated in situ using transmission electron microscopy (TEM), selected-area electron diffraction and high-resolution transmission electron microscopy. The EB irradiation for 2-8 min enhanced the construction of bismuth nanoparticles with a rhombohedral structure and diameter of 4-9 nm. The average particle size was found to increase with the irradiation time. Bismuth metal has a melting point of 271 Degree-Sign C and this low melting temperature makes easy the progress of energy induced structural changes during in situ TEM observations. This is a very useful technique in nano-patterning for integrated optics and other applications.

Singh, Shiv Prakash; Karmakar, Basudeb, E-mail: basudebk@cgcri.res.in [Central Glass and Ceramic Research Institute (CSIR, India), Glass Science and Technology Section, Glass Division (India)

2011-09-15

384

Fabrication and characteristics of in situ Al12W particles reinforced aluminum matrix composites by reaction sintering  

International Nuclear Information System (INIS)

A novel in situ Al12W particles reinforced aluminum matrix composite was synthesized by reaction sintering of tungsten and aluminum powders and followed by hot extrusion. The microstructures were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The tensile tests of composite and pure aluminum materials were measured. The XRD analysis identifies that the in situ Al12W particles are formed by the reaction between tungsten and aluminum powders. Meanwhile, SEM observation shows that the Al12W particles are distributed uniformly in the Al matrix, and TEM observation shows that the interfacial condition of Al12W particles and Al is good. It is found from the tensile tests that the in situ synthesized Al12W particles can significantly enhance the strength of the composite in spite of decreasing elongation. The fracture morphology analysis reveals that the fracture mode of composite is ductile fracture.

385

High resolution measurements of carbon monoxide along a late Holocene Greenland ice core: evidence for in situ production  

Science.gov (United States)

We present high-resolution measurements of carbon monoxide (CO) concentrations from a shallow ice core of the North Greenland Eemian Ice Drilling project (NEEM-2011-S1). An optical-feedback cavity-enhanced absorption spectrometer (OF-CEAS) coupled to a continuous melter system performed continuous, online analysis during a four-week measurement campaign. This anal