WorldWideScience
1

In situ containment and stabilization of buried waste  

Energy Technology Data Exchange (ETDEWEB)

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

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

1992-11-01

2

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-09-15

3

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

International Nuclear Information System (INIS)

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

4

In situ solution mining technique  

International Nuclear Information System (INIS)

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

5

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

International Nuclear Information System (INIS)

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

6

In situ vitrification: application analysis for stabilization of transuranic waste  

International Nuclear Information System (INIS)

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

7

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1992-11-01

8

Chemoport anchoring – the in situ technique  

Directory of Open Access Journals (Sweden)

Full Text Available Chemoports are subcutaneously placed long term central venous access devices usually inserted under local anaesthesia. Rare complications include port inversion or flip over. These can be prevented by anchoring the port to the tissues at its base. We describe an in situ technique of port anchoring. Here, the port is first ‘fixed’ temporarily to the overlying skin by Huber needle, thus facilitating placement of fixing sutures without port manipulation. The described technique is safe and we have not encountered complications. In addition, ex - planting the port was easier due to the use of delayed absorbable sutures. It is safer to anchor the port even if the port pocket ensures that the port fits in snugly. This described technique results in minimal manipulation of portcatheter system thereby ensuring that the catheter tip which is properly placed remains unaltered.

Yagachikatte Chikkanarasaiah Madhu

2011-04-01

9

Optical metrology techniques for dimensional stability measurements:  

OpenAIRE

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

Ellis, Jonathan David

2010-01-01

10

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

11

In situ uranium stabilization by microbial metabolites.  

Science.gov (United States)

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(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. PMID:18222573

Turick, Charles E; Knox, Anna S; Leverette, Chad L; Kritzas, Yianne G

2008-06-01

12

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

13

Efficient technique for measuring laser frequency stability  

OpenAIRE

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

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

2009-01-01

14

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-11-15

15

In Situ Contaminate Stabilization within a Complex and Highly Heterogeneous Fractured Media  

Science.gov (United States)

Radionuclides that are adsorbed in vadose zone soils are a contamination source of subsurface waters on DOE sites. Source contamination typically was a localized leak in surface or near-surface process equipment. Immobilizing or sequestering such contaminants in situ is a preferred remediation technique for economic and technical reasons. In situ contaminate stabilization can be challenging when the subsurface geology is complex and highly heterogeneous. The contaminate stabilization is accomplished by introducing an amendment, water-soluble polymer, into contact with the contaminated porous medium. This paper will present results from a series of laboratory experiments preformed in layered heterogeneous tanks that were monitored using 4 D electrical resistivity, temperature, conductivity of incoming and outgoing tank fluids. The experiments were designed to show that monitoring as well as sequestering radionuclides (Sr90) in perched groundwater within fractured media was possible.

Scott, C. L.; Heath, G. L.; Baker, K. E.; Schafer, A. L.

2006-12-01

16

Floc Stabilization for Multiple Microscopic Techniques  

OpenAIRE

A nondestructive stabilization technique for the characterization of microbial flocs which permits the application of correlative microscopic techniques is described. Flocs embedded in agarose are retained in a porous, resilient medium which allows for the transport, staining, washing, and subsampling of the flocculated material directly within a plankton chamber with minimal or no destructive forces. A single agarose disc can be subdivided into numerous sections for analysis by several micro...

Droppo, I. G.; Flannigan, D. T.; Leppard, G. G.; Jaskot, C.; Liss, S. N.

1996-01-01

17

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-10-01

18

In-situ containment and stabilization of buried waste  

International Nuclear Information System (INIS)

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

19

In situ stabilization of soil lead using phosphorus.  

Science.gov (United States)

In situ stabilization of Pb-contaminated soils can be accomplished by adding phosphorus. The standard remediation procedure of soil removal and replacement currently used in residential areas is costly and disruptive. This study was carried out to evaluate the influence of P and other soil amendments on five metal-contaminated soils and mine wastes. Seven treatments were used: unamended control; 2,500 mg of P/kg as triple superphosphate (TSP), phosphate rock (PR), acetic acid followed by TSP, and phosphoric acid (PA); and 5,000 mg of P/kg as TSP or PR. A significant reduction in bioavailable Pb, as determined by the physiologically based extraction test (PBET), compared with the control upon addition of P was observed in all materials tested. Increasing the amount of P added from 2,500 to 5,000 mg/kg also resulted in a significantly greater reduction in bioavailable Pb. Phosphate rock was equally or more effective than TSP or PA in reducing bioavailable Pb in four out of five soils tested. Preacidification produced significantly lower bioavailable Pb compared with the same amount of P from TSP or PR in only one material. Reductions in Pb bioavailability as measured by PBET were evident 3 d after treatment, and it may indicate that the reactions between soil Pb and P occurred in situ or during the PBET. No further reductions were noted over 365 d. X-ray diffraction data suggested the formation of pyromorphite-like minerals induced by P additions. This study suggests that P addition reduced bioavailable Pb by PBET and has potential for in situ remediation of Pb-contaminated soils. PMID:11476498

Hettiarachchi, G M; Pierzynski, G M; Ransom, M D

2001-01-01

20

In Situ Community Control of the Stability of Bioreduced Uranium  

Energy Technology Data Exchange (ETDEWEB)

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

White, David C.

2005-06-01

21

Technique for in situ leach simulation of uranium ores  

International Nuclear Information System (INIS)

In situ uranium mining offers the advantages of minimal environmental disturbance, low capital and operating costs, and reduced mining development time. It is becoming an increasingly attractive mining method for the recovery of uranium from secondary ore deposits. In order to better understand the process, a laboratory technique was developed and used to study and simulate both the chemical and physical phenomena occurring in ore bodies during in situ leaching. The laboratory simulation technique has been used to determine effects of leaching variables on permeability, uranium recovery, and post-leach aquifer restoration. This report describes the simulation system and testing procedure in sufficient detail to allow the construction of the system, and to perform the desired leaching tests. With construction of such a system, in situ leaching of a given ore using various leach conditions can be evaluated relatively rapidly in the laboratory. Not only could optimum leach conditions be selected for existing ore bodies, but also exploitation of new ore bodies could be accelerated. 8 references, 8 figures, 2 tables

22

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

Science.gov (United States)

We report on the loading and release of curcumin (a hydrophobic polyphenol with anti-inflammatory and anti-bacterial properties) from polyelectrolyte multilayers composed of poly(diallyldimethylammonium chloride) (PDADMAC) and poly(sodium 4-styrenesulfonate) (PSS). We have used the in situ techniques of attenuated total reflectance (ATR) FTIR spectroscopy and quartz crystal microbalance with dissipation monitoring (QCM-D) to study the formation of the PEM and the incorporation of curcumin, providing direct evidence of the incorporation, in terms of molecular vibrations and gravimetric detection. The release of curcumin was followed using ex situ measurements of UV-visible spectroscopy of PEM films on quartz plates, in addition to in situ ATR FTIR measurements. Release was studied as a function of salt concentration of the release solution (0.001 M NaCl; 1 M NaCl). UV-visible spectroscopy indicated that salt concentration of the release solution had a major impact on release rates, with higher salt giving faster/more extensive release. However, prolonged timescale immersion and monitoring with UV-visible spectroscopy indicated that sample dehydration/rehydration cycling (required to measure UV absorbance) was responsible for the release of curcumin, rather than immersion time. In situ measurements of release kinetics with ATR FTIR confirmed that release does not occur spontaneously while the multilayer remains hydrated. PMID:25226281

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

2014-10-28

23

Review and prospect for uranium mining technique in-situ leaching in China  

International Nuclear Information System (INIS)

The author presents the history and current situation of China uranium mining in-situ leaching, reviews uranium mining technique of in-situ leaching, poses a question for study and solution in development of in-situ leaching, and looks forward to resources and bright future of uranium mining in-situ leaching

24

Engineering feasibility analysis for in-situ stabilization of Canonsburg residues  

International Nuclear Information System (INIS)

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

25

Transient Stability Assessment using Decision Trees and Fuzzy Logic Techniques  

OpenAIRE

Many techniques are used for Transient Stability assessment (TSA) of synchronous generators encompassing traditional time domain state numerical integration, Lyapunov based methods, probabilistic approaches and Artificial Intelligence (AI) techniques like pattern recognition and artificial neural networks.This paper examines another two proposed artificial intelligence techniques to tackle the transient stability problem. The first technique is based on the Inductive Inference Reasoning (IIR)...

Abdelaziz, A. Y.; El-dessouki, M. A.

2013-01-01

26

An in situ electron microscopy technique for the study of thermally activated reactions in multilayered materials  

Energy Technology Data Exchange (ETDEWEB)

A novel in situ transmission electron microscopy technique for the observation of reaction processes in multilayered materials is reported. The technique involves constant heating rate experiments of multilayered materials in image and diffraction modes. Because the fine scale microstructure of multilayered materials is typically a small fraction of the TEM specimen thickness, realistic comparison of the microstructural evolution with that of similarly processed thick foil samples is possible. Such experiments, when well designed, can provide rapid characterization of phase transformations and stability of nano-structured materials. The results of these experiments can be recorded in both video and micrograph format. The results and limitations of this technique will be shown for the Al/Zr and Al/Monel multilayered systems.

Wall, M.A.; Barbee, T.W. Jr.; Weihs, T.P. [Lawrence Livermore National Lab., CA (United States). Chemistry and Materials Science Dept.

1995-04-14

27

Experimental Investigation of Centrifugal Compressor Stabilization Techniques  

Science.gov (United States)

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

Skoch, Gary J.

2003-01-01

28

An in situ technique for elemental analysis of lunar surfaces  

Science.gov (United States)

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

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

1992-09-01

29

A novel in-situ measuring technique for aspheric surface  

Science.gov (United States)

In this paper, a novel in-situ surface measuring technique for optical elements with aspheric surface is presented. It is a contact type probe, and can be used for measuring ground surfaces. The theory of this technique develops from coordinate measuring machine (CMM), and the measurement accuracy of this technique is depended on the accuracy of computer numerical controlled (CNC). By installing a special equipment with high accuracy measuring head in main spindle of CNC machine, and moving the probe along the path which is described by a mathematical aspheric expression precisely, we could get relative errors of sag height of any position in this path. With this technique, the repeat positioning error caused by traditional off-line measurement will be avoided. The author also has finished a special software with VC++ 6.0. With this software, the form error of ground work piece could be corrected rapidly. This software can calculate and handle the arrangement automatically with all parameters which are required to input in operation interface. In the correction stage, the software can analyze and process error data and generate a new NC program with corrected data for next grinding stage. After 2 or 3 times measuring and correction, the surface shape error of the aspheric optical element will be less than 1?m. The finished work piece has a very good surface finish and can be polished with high quality.

Zhang, Chuan; Wang, Ping; Chen, Yaolong

2011-11-01

30

An in Situ Technique for Elemental Analysis of Lunar Surfaces  

Science.gov (United States)

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

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

1992-01-01

31

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

Energy Technology Data Exchange (ETDEWEB)

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

Lew, J.; Snipes, R. [Environmental Management and Enrichment Facilities, Oak Ridge, TN (United States); Tamura, T.

1996-12-31

32

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

International Nuclear Information System (INIS)

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

33

COMPARISON OF DIFFERENT TECHNIQUES FOR DESIGN OF POWER SYSTEM STABILIZER  

Directory of Open Access Journals (Sweden)

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

M. Ravindra Babu,

2011-05-01

34

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

Directory of Open Access Journals (Sweden)

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

Yadollah Gharayebi

2011-09-01

35

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

Science.gov (United States)

In this paper, Polyimide/Montmorillonite Nanocomposites (PI/MMT NCs), based on aromatic diamine (4-Aminophenyl sulfone) (APS) and aromatic dianhydride (3,3?,4,4?-benzophenonetetracarboxylic dianhydride) (BTDA) were prepared using in situ polymerization and solution-dispersion techniques. The prepared PI/MMT NCs films were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The XRD results showed that at the content of 1.0 wt % Organo Montmorillonite (OMMT) for two techniques and 3.0 wt % OMMT for the in situ polymerization technique, the OMMT was well-intercalated, exfoliated and dispersed into polyimide matrix. The OMMT agglomerated when its amount exceeded 10 wt % and 3.0 wt % for solution-dispersion and in situ polymerization techniques respectively. These results were confirmed by the TEM images of the prepared PI/MMT NCs. The TGA thermograms indicated that thermal stability of prepared PI/MMT NCs were increased with the increase of loading that, the effect is higher for the samples prepared by in situ polymerization technique. PMID:22016643

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

2011-01-01

36

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

International Nuclear Information System (INIS)

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

37

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

International Nuclear Information System (INIS)

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

38

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

OpenAIRE

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

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

2009-01-01

39

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

CERN Document Server

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

Martínez, E

2003-01-01

40

Contributions to fuzzy polynomial techniques for stability analysis and control  

OpenAIRE

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

Pitarch Pe?rez, Jose? Luis

2014-01-01

41

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

International Nuclear Information System (INIS)

This paper is based on a feasibility study conducted by Roy F. Weston, Inc., for Sandia National Laboratory for the US Department of Energy's UMTRAP Project Office in Albuquerque, New Mexico. The US DOE is considering several methods for carrying out remedial actions in Canonsburg, Pennsylvania, at the site of an inactive uranium-processing mill. The main objective of this study is to determine the feasibility of in-situ stabilization as the remedial action. In-situ stabilization is an alternative to site decontamination and offsite disposal. The problems associated with offsite hauling of large quantities of contaminated material and with the location and development of a new disposal site could be avoided by the implementation of an in-situ stabilization concept. In addition, the in-situ approach would be more cost-effective than offsite disposal. This study will establish that a technically feasible and implementable in-situ stabilization concept can be developed that meets regulatory requirements and is cost-effective

42

In-situ subsurface density estimations using a seismic technique  

OpenAIRE

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

Fourie, Christoffel Johannes Stephanus

2009-01-01

43

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

Energy Technology Data Exchange (ETDEWEB)

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

Kalb,P.D.; Milian, L.

2008-03-01

44

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

Science.gov (United States)

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

45

IN-SITU STABILIZATION/SOLIDIFICATION OF PCB-CONTAMINATED SOIL  

Science.gov (United States)

An evaluation was performed of the International Waste Technologies (IWT) HWT-20 additive and the Geo-Con, Inc. deep-soil-mixing equipment for an in situ stabilization/solidification process and its applicability as an onsite treatment method for waste site cleanup. emonstration ...

46

In situ transmission electron microscopy study of the strength and stability of nanoscaled structural materials  

Energy Technology Data Exchange (ETDEWEB)

The interest for nanoscaled structural materials, which increased during the last years, is essentially based on their enhanced mechanical strength due to grain refinement. In situ TEM experiments may provide valuable information on mechanisms responsible for both specific mechanical properties and structural stability of nanoscaled materials. (orig.)

Louchet, F.; Veron, M. [Institut National Polytechnique de Grenoble, Saint-Martin-d' Heres (FR). Lab. de Thermodynamique et Physico-Chimie Metallurgique (LTPCM); Blandin, J.J. [Institut National Polytechnique de Grenoble, Saint-Martin-d' Heres (FR). Genie Physique et Mecanique des Materiaux (GPM2)

2001-08-01

47

In situ applications of FPXRF techniques in mineral exploration  

International Nuclear Information System (INIS)

The paper describes an optimum sampling methodology for in situ XRF analysis of rock and soil samples. It also presents major interfering effects that affect the accuracy of quantitative analysis together with the relevant correction procedures. Selected applications for mineral prospecting of large areas and relevant standard operating procedures are also presented. (author)

48

Power system stabilizers based on modern control techniques  

Energy Technology Data Exchange (ETDEWEB)

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

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

1994-12-31

49

Routine application of the in situ soil analysis technique by the Yankee Atomic Environmental Laboratory  

International Nuclear Information System (INIS)

Using a technique developed by the Environmental Measurements Laboratory (EML) for field spectrometry, the Yankee Atomic Environmental Laboratory (YAEL) has routinely performed in situ soil measurements in the vicinity of five nuclear power stations for more than a decade. As a special research endeavor, several locations at the FURNAS Angra 1 site in Brazil having high natural backgrounds were also measured in 1987. The technical basis of the technique, a comparison of soil radionuclide concentrations predicted by the in situ technique to soil radionuclide concentrations predicted by the in situ technique to soil analyses from the same sites, the advantages and disadvantages of the in situ methodology, and the evolution of the portable equipment utilized at YAEL for the field measurements are presented in this paper

50

Investigating structure-property relationships in cathode materials via combined ex-situ and in-situ diffraction techniques  

International Nuclear Information System (INIS)

While anode and electrolyte materials continue to see significant advances, cathode materials remain underdeveloped in comparison. As a battery's performance is determined by its weakest component further improvements to cathode materials are essential. Given the complex chemical and structural changes which can take place in cathode materials on cycling, a range of advanced characterization techniques must be utilised in order to understand the properties well enough to then improve upon them. A combination and ex-situ type dialyses has been performed on the cathode material Li0.18Sr0.66Ti0.5BNb0.5O3. Ex-situ neutron diffraction experiments, following the chemical insertion of lithium enabled the location of lithium within the structure to be accurately determined through Rietveld refinement and calculation of Fourier difference maps. More significantly, the evolution of phases and structural change in this material has been followed utilizing both in-situ neutron and synchrotron diffraction experiments. Sequential Rietveld refinements have allowed the change in structure to be directly correlated with the observed electrochemical properties. Specifically, due to the real time collection of structure; data as a function of discharge. the rate of structural change was measured and directly correlated with electrochemical portfolio. This contribution will demonstrate how a combination of ex-situ diffraction of chemical and electrochemical insertion of lithium as well as in-situ diffraction of electrochemical insertion of lithium can provide a robust picture of how the structure influences properties.

51

Stabilization of microorganisms for in situ degradation of toxic chemicals  

International Nuclear Information System (INIS)

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

52

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

Science.gov (United States)

The goal of this study was to obtain physically stable non-aqueous in situ forming microparticle (ISM) emulsions capable of forming biodegradable microparticles upon injection. ISM emulsions consist of a biocompatible organic PLGA solution dispersed in a continuous oil phase prepared in a two-syringe/connector system prior to administration. A variety of parenteral approved excipients were tested for a stability-enhancing effect and possible stabilization mechanisms evaluated. Glycerol monostearate (GMS) showed superior stabilizing potential prolonging the emulsion stability from a few minutes to more than 12h. Flow behavior analysis, differential scanning calorimetry, polarized light- and Cryo-electron microscopy revealed, that the stabilization was caused by an immediate, more than 5-fold viscosity increase in the continuous phase after emulsification and by a stabilized interface through a liquid crystalline GMS layer around the polymer solution droplets. Despite the viscosity increase the injectability of the stabilized ISM emulsion was improved by about 30% compared to the corresponding highly viscous PLGA solution (in situ implant) due to a pronounced shear thinning of the GMS containing oil phase. The injectability improvement allows a faster administration or enables the use of thinner needles and hence reduced patient discomfort. PMID:22677417

Voigt, M; Koerber, M; Bodmeier, R

2012-09-15

53

TESTING TECHNIQUE OF MOTOR PETROL PHYSICAL STABILITY ESTIMATION AND FORECASTING  

OpenAIRE

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

Boychenko, Sergey V.; Sidorenko, Nina A.; Chernyak, Larisa N.; Pugachevskaya, Eugenya P.

2009-01-01

54

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

International Nuclear Information System (INIS)

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

55

Cervical Spine Motion during Transfer and Stabilization Techniques.  

Science.gov (United States)

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

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

2015-01-01

56

Single Molecule Techniques for Advanced in situ Hybridization  

International Nuclear Information System (INIS)

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

57

In situ versus laboratory analysis of sediment stability from intertidal mudflats  

Science.gov (United States)

Measurements of intertidal mudflat erosion thresholds from in situ and laboratory erosion devices were contrasted. Alteration of the critical erosion shear stresses was potentially brought about either by physical disturbance (vibration, compaction and water loss), ongoing biological activity or changes in the behaviour of infaunal organisms during transport and resting of the excavated cores. In an initial experiment, box cores were collected from the Humber estuary Skeffling mudflats (April 1995) and transported back to the laboratory for measurement in a linear flume. These cores suffered visible disturbance during transport to the laboratory and their erosion thresholds were considerably higher than in situ data obtained by the Sea Carousel erosion device. In the main study, cylindrical cores collected in the Sylt-Rømø Bight (June 1998) were collected and transported in a manner that minimised disturbance. The stability of these cores was measured with the EROMES laboratory erosion device and compared to near-by in situ measurements taken with the cohesive strength meter (CSM) erosion device. These devices use different criterion to calculate the erosion threshold (erosion rate and attenuation threshold, respectively), resulting in differences in the calculated erosion threshold. However, when an attenuation threshold was used for both devices the erosion thresholds were comparable. When disturbance of cores was minimised, in situ and lab erosion thresholds were comparable. However, user bias in site selection can influence results where there is spatial variation in sediment properties. Stability measurements should therefore be made on randomly selected sediment areas.

Tolhurst, T. J.; Riethmüller, R.; Paterson, D. M.

2000-07-01

58

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

Energy Technology Data Exchange (ETDEWEB)

Addition of an amendment or reagent to soil/sediment is a technique that can decrease mobility and reduce bioavailability of uranium (U) and other heavy metals in the contaminated site. According to data from literature and results obtained in field studies, the general mineral class of apatites was selected as a most promising amendment for in situ immobilization/remediation of U. In this work we presented theoretical assessment of stability of U(VI) in four apatite systems (hydroxyapatite (HAP), North Carolina Apatite (NCA), Lisina Apatite (LA), and Apatite II) in order to determine an optimal apatite soil amendment which could be used for in situ remediation of uranium. In this analysis we used a theoretical criterion which is based on calculation of the ion-ion interaction potential, representing the main term of the cohesive energy of the matrix/pollutant system. The presented results of this analysis indicate (i) that the mechanism of immobilization of U by natural apatites depends on their chemical composition and (ii) that all analyzed apatites represent, from the point of view of stability, promising materials which could be used in field remediation of U-contaminated sites.

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

2006-02-15

59

In-situ verification techniques for fast critical assembly cores  

International Nuclear Information System (INIS)

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

60

Robust Digital Image Stabilization Technique for Car Camera  

OpenAIRE

This research studies the digital image stabilization technique for the In-Car videos which are acquired from a car camera. Firstly, the relationship is established between the lane-line positions in a camera coordinate and an image plane. Then an analysis is performed to reveal the positions of the lane-lines in In-Car videos. Next, a digital image stabilization method for car cameras is proposed based on lane-line matching. This method begins with extracting the lane-lines from an In-Car vi...

Yuefei Zhang; Mei Xie

2011-01-01

61

Study and applications of in-situ XRF prospecting gold technique  

International Nuclear Information System (INIS)

Two kinds of portable XRF analyzer have been developed, 2 to 6 elements can be measured simultaneously in-situ. An XRF prospecting gold technique with multi-parameter XRF analyzer has been developed, good gold prospecting effects have been obtained in 'Sanjiang', and 'Jinsanjiao' areas of Sichun in China

62

Techniques for heap and in situ leach simulation on uranium ores  

International Nuclear Information System (INIS)

Bureau of Mines sponsored research has developed techniques for simulation of heap and in situ leaching of uranium ores. The heap leach technique uses 2 ft dia (60.9 cm) columns with bed depths ranging from 8 ft to 18 ft (2.44 m to 5.49 m). Uranium ores as coarse as minus 4 in (101.6 mm) can be treated. The simulation technique for in situ leaching uses 4 in dia by 12 ft long (101.6 mm by 3.66 m) horizontal columns. The technique was developed to determine the effect of leaching variables such as solution composition on the bed permeability, uranium recovery, and post-leach aquifer restoration. References to detailed experimental data developed with these systems are included. (author). 9 refs, figs, 1 tab

63

Using geophysical techniques to control in situ thermal remediation  

International Nuclear Information System (INIS)

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

64

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

International Nuclear Information System (INIS)

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

65

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

Science.gov (United States)

The in situ (in place) immobilization of toxic metals, using inexpensive "reactive" amendments, is considered as a simple and cost-effective approach for the treatment of soils, contaminated by the presence of heavy metals, when these soils are difficult or costly to be removed and treated ex situ. Several application studies have demonstrated that the stabilization of contaminated soils and groundwaters by the addition of apatite minerals has the potential to be a successful and widely applicable remediation strategy for the case of Pb, Cd, as well as for other toxic metals, existing in polluted soils. On the other hand, the specific immobilization mechanism(s) of these toxic metals remains rather elusive. The present work involves an interdisciplinary theoretical and experimental approach, designed to gain at the fundamental (molecular) level the understanding of respective mechanisms, considering the immobilization of Pb and Cd by the addition of apatites. The theoretical analysis of stability, regarding the apatite/Pb or apatite/Cd systems and the relevant results of sorption experiments, pointed out two different mechanisms for the immobilization of Pb or Cd by the use of apatites. The possible practical consequences of these findings for the selection/application of natural apatites for the remediation of contaminated soils by the presence of heavy metals have been also discussed. PMID:15621352

Raicevic, S; Kaludjerovic-Radoicic, T; Zouboulis, A I

2005-01-14

66

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2008-02-25

67

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-09-15

68

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

International Nuclear Information System (INIS)

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

69

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

International Nuclear Information System (INIS)

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

70

Comparative review of techniques used for in situ remediation of contaminated soils  

International Nuclear Information System (INIS)

Soil pollution may influence the geotechnical parameters of the soil itself, properties such as solid particle density or water within its pores. It may also vary its friction angle, modify its structure and texture, or change the properties of its constitutive minerals due to the inclusion of polluting components. For these reasons, soil decontamination is an important factor to consider in geotechnics. This work focuses on those soil decontamination techniques carried out in situ, since they allow to eliminate soil pollutants in a less invasive way than confinement, containment or ex situ remediation techniques, causing a minor soil alteration and, therefore, affecting less to its mechanical properties. These factors should be taken into account when carrying out a geotechnical performance on a previously decontaminated soil. (Author)

71

Enhanced morphological and thermal stabilities of nickel germanide with an ultrathin tantalum layer studied by ex situ and in situ transmission electron microscopy.  

Science.gov (United States)

The formation and morphological evolution of germanides formed in a ternary Ni/Ta-interlayer/Ge system were examined by ex situ and in situ annealing experiments. The Ni germanide film formed in the Ni/Ta-interlayer/Ge system maintained continuity up to 550°C, whereas agglomeration of the Ni germanide occurred in the Ni/Ge system without Ta-interlayer. Through microstructural and chemical analysis of the Ni/Ta-interlayer/Ge system during and after in situ annealing in a transmission electron microscope, it was confirmed that the Ta atoms remained uniformly on the top of the newly formed Ni germanide layer during the diffusion reaction. Consequently, the agglomeration of the Ni germanide film was retarded and the thermal stability was improved by the Ta incorporation. PMID:23920187

Lee, Jae-Wook; Kim, Hyung-Kyu; Bae, Jee-Hwan; Park, Min-Ho; Kim, Hyoungsub; Ryu, Jiho; Yang, Cheol-Woong

2013-08-01

72

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1993-10-01

73

Robust Digital Image Stabilization Technique for Car Camera  

Directory of Open Access Journals (Sweden)

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

Yuefei Zhang

2011-01-01

74

Grout performance in support of in situ stabilization/solidification of the GAAT tank sludges  

International Nuclear Information System (INIS)

The Gunite trademark and associated tanks (GAATs) were constructed at ORNL between 1943 and 1951 and were used for many years to collect radioactive and chemical wastes. These tanks are currently inactive. Varying amounts of the sludge were removed and disposed of through the Hydrofracture Program. Thus, some tanks are virtually empty, while others still contain significant amounts of sludge and supernatant. In situ grouting of the sludges in the tanks using multi-point injection (MPI trademark), a patented, proprietary technique, is being investigated as a low-cost alternative to (1) moving the sludges to the Melton Valley Storage Tanks (MVSTs) for later solidification and disposal, (2) ex situ grouting of the sludges followed by either disposal back in the tanks or containerizing and disposal elsewhere, and (3) vitrification of the sludges. The paper discusses the chemical characteristics of the GAATs and the type of chemical surrogate that was used during the leachability tests. This is followed by the experimental work, which, consisted of scope testing and sensitivity testing. The scope testing explored the rheology of the proposed jetting slurries and the settling properties of the proposed grouts using sand-water mixes for the wet sludge. After establishing a jetting slurry and grout with an acceptable rheology and settling properties, the proposed in situ grout formulation was subjected to sensitivity testing for variations in the formulation

75

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

DEFF Research Database (Denmark)

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

Teran-Escobar, Gerardo; Tanenbaum, David

2012-01-01

76

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

DEFF Research Database (Denmark)

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

Nielsen, Per H.; Christensen, Thomas HØjlund

1996-01-01

77

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

Science.gov (United States)

Chemical stabilization is an in situ remediation method that uses inexpensive amendments to reduce contaminant availability in polluted soil. We tested the effects of several amendments (limestone, red-mud, and furnace slag) on the extractability of heavy metals, microbial activities, phytoavailability of soil metals (assessed using lettuce, Lactuca sativa L.), and availability of heavy metals in ingested soil to the human gastrointestinal system (assessed using the physiologically based extraction test). The application of soil amendments significantly decreased the amount of soluble and extractable heavy metals in the soil (pamended soils. Red-mud was the most effective treatment in decreasing heavy-metal concentrations in lettuce. Compared to non-amended control soil, lettuce uptake of Cd, Pb, and Zn was reduced 86%, 58%, and 73%, respectively, by the addition of red-mud. PMID:19786291

Lee, Sang-Hwan; Lee, Jin-Soo; Choi, Youn Jeong; Kim, Jeong-Gyu

2009-11-01

78

Deformation processes in functional materials studied by in situ neutron diffraction and ultrasonic techniques  

International Nuclear Information System (INIS)

The unique thermomechanical functions of shape memory alloys (hysteretic stress-strain-temperature responses) not their structural properties (as strength, fatigue, corrosion resistance, etc.) are primarily utilized in engineering applications. In order to better understand and predict the functional behavior, we have recently employed two dedicated non-invasive in situ experimental methods capable to follow the deformation/transformation processes in thermomechanically loaded polycrystalline samples. The in situ neutron diffraction method takes advantage of the ability of thermal neutrons to penetrate bulk samples. As a diffraction technique sensitive to interplanar spacings in crystalline solids, it provides in situ information on the changes in crystal structure, phase composition, phase stress and texture in the transforming samples. The combined in situ ultrasonic and electric resistance method follows variations of the electric resistance as well as speed and attenuation of acoustic waves propagating through the transforming sample. The acoustic waves are mainly sensitive to changes of elastic properties accompanying the deformation/transformation processes. The latter method thus follows the changes in interatomic bonds rather than changes in the interplanar lattice spacings focused in the neutron diffraction method. The methods are thus complementary. They are briefly described and selected experimental results obtained recently on NiTi alloys are presented and recently on NiTi alloys are presented and discussed

79

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

Science.gov (United States)

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

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

2012-09-01

80

In situ stabilization of soil lead using phosphorus and manganese oxide: influence of plant growth.  

Science.gov (United States)

In situ stabilization of Pb contaminated soils can be accomplished by adding P and Mn(IV) oxide. However, the long-term efficacy of in situ stabilization under continual P removal through plant growth is unknown. Moreover, the effects these treatments have on phytoavailability of other metals (Cd and Zn) commonly associated with Pb in soil are not well understood. Greenhouse experiments using sudax [Sorghum vulgare (L.) Moench] and Swiss chard [Beta vulgaris (L.) Koch] were carried out to evaluate the effects of plant growth on soil Pb bioavailability to humans after addition of P and other amendments, and the effects of these treatments on Pb, Cd, and Zn phytoavailability in three metal-contaminated soils. Eight treatments were used: zero P; 2500 mg of P as triple superphosphate (TSP); 5000 mg of P as TSP or phosphate rock (PR); 5000 mg of Mn oxide/kg; and combinations of Mn oxide and P as TSP or PR. The addition of P and/or Mn oxide significantly reduced bioavailable Pb, as measured by the physiologically based extraction test (PBET), in soils compared with the control even after extensive cropping. The PBET data also suggested that removal of P from soluble P sources by plants could negate the beneficial effects of P on bioavailable Pb, unless sufficient soluble P was added or soluble P was combined with Mn oxide. In general, Ph, Cd, and Zn concentrations in shoot tissues of sudax and Swiss chard were reduced significantly by TSP and did not change with the addition of PR. The combination of PR and Mn oxide significantly reduced Pb concentrations in plants compared with the control. PMID:11931448

Hettiarachchi, Ganga M; Pierzynski, Gary M

2002-01-01

81

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

OpenAIRE

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

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

2012-01-01

82

In situ measurement of the effect of LiOH on the stability of zircaloy-2 surface film in PWR water  

International Nuclear Information System (INIS)

Surface films on the metals play a major role in corrosion assisted cracking. A new method called Contact Electric Resistance (CER) method has been recently developed for in situ measurement of the electric resistance of surface films in high temperature and high pressure environments. The technique has been used to determine in situ the electric resistance of films on metals when in contact with water and dissolved anions, during formation and destruction of oxides and hydrides and during electroplating of metals. Electric resistance data can be measured with a frequency of the order of one hertz, which makes it possible to investigate in situ the kinetics of surface film related processes which are dependent on the environment, temperature, pH and electrochemical potential. This paper presents the results of the CER investigation on the effects of LiOH on the stability of Zircaloy-2 surface film in water with 2000 ppm H3BO3. At 300 deg. C the LiOH concentrations higher than 10-2 M (roughly 70 ppm of Li+) were found to markedly reduce the electric resistance of the Zircaloy-2 surface film during a test period of less than two hours. The decrease of the film resistance is very abrupt, possibly indicating a phase transformation. Moreover, the advantages of the CER technique over the other competing techniques which rely on the measurement of current are discussed. (author)

83

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

International Nuclear Information System (INIS)

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

84

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

Science.gov (United States)

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

85

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

Science.gov (United States)

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

86

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

Science.gov (United States)

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

87

SITE PROGRAM APPLICATIONS ANALYSIS REPORT, INTERNATIONAL WASTE TECHNOLOGIES/GEO CON IN-SITU STABILIZATION/SOLIDIFICATION  

Science.gov (United States)

An evaluation was performed of the International Waste Technologies (IWT) HWT-20 additive and the Geo-Con, Inc. deep-soil-mixing equipment for an in situ stabilization/solidification process and its applicability as an on-site treatment method for waste site cleanup. emonstration...

88

Making a Hybrid Microfluidic Platform Compatible for In Situ Imaging by Vacuum-Based Techniques  

Energy Technology Data Exchange (ETDEWEB)

A self-contained microfluidic-based device was designed and fabricated for in situ imaging of aqueous surfaces using vacuum techniques. The device is a hybrid between a microfluidic PDMS block and external accessories, all portable on a small platform (10 cm-8 cm). The key feature is that a small aperture with a diameter of 2-3 micrometers is opened to the vacuum, which serves as a detection window for in situ imaging of aqueous surfaces. Vacuum compatibility and temperature drop due to water vaporization are the two most important challenges in this invention. Theoretical calculations and fabrication strategies are presented from multiple design aspects. In addition, results from the time-of-flight secondary ion mass spectrometry (ToF-SIMS) of aqueous surfaces are presented.

Yang, Li; Yu, Xiao-Ying; Zhu, Zihua; Thevuthasan, Suntharampillai; Cowin, James P.

2011-10-26

89

Hybrid Video Stabilization Technique for Hand Held Mobile Videos  

Directory of Open Access Journals (Sweden)

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

Prof. Paresh Rawat

2011-05-01

90

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

Directory of Open Access Journals (Sweden)

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

Ding Wei

2010-11-01

91

Stabilized amorphous glibenclamide nanoparticles by high-gravity technique  

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-10-17

92

Stabilized amorphous glibenclamide nanoparticles by high-gravity technique  

International Nuclear Information System (INIS)

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

93

Implementation of In-Situ Impedance Techniques on a Full Scale Aero-Engine System  

Science.gov (United States)

Determination of acoustic liner impedance for jet engine applications remains a challenge for the designer. Although suitable models have been developed that take account of source amplitude and the local flow environment experienced by the liner, experimental validation of these models has been difficult. This is primarily due to the inability of researchers to faithfully mimic the environment in jet engine nacelles in the laboratory. An in-situ measurement technique, one that can be implemented in an actual engine, is desirable so an accurate impedance can be determined for future modeling and quality control. This paper documents the implementation of such a local acoustic impedance measurement technique that is used under controlled laboratory conditions as well as on full scale turbine engine liner test article. The objective for these series of in-situ measurements is to substantiate treatment design, provide understanding of flow effects on installed liner performance, and provide modeling input for fan noise propagation computations. A series of acoustic liner evaluation tests are performed that includes normal incidence tube, grazing incidence tube, and finally testing on a full scale engine on a static test stand. Lab tests were intended to provide insight and guidance for accurately measuring the impedance of the liner housed in the inlet of a Honeywell Tech7000 turbofan. Results have shown that one can acquire very reasonable liner impedance data for a full scale engine under realistic test conditions. Furthermore, higher fidelity results can be obtained by using a three-microphone coherence technique that can enhance signal-to-noise ratio at high engine power settings. This research has also confirmed the limitations of this particular type of in-situ measurement. This is most evident in the installation of instrumentation and its effect on what is being measured.

Gaeta, R. J.; Mendoza, J. M.; Jones, M. G.

2007-01-01

94

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

Directory of Open Access Journals (Sweden)

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

Li X.L.

2010-06-01

95

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

Directory of Open Access Journals (Sweden)

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

M. Q. Liu

2015-01-01

96

Practical applications of in-situ plasma-etching diagnostic techniques  

International Nuclear Information System (INIS)

Mass spectrometry, ellipsometry and optical emission spectroscopy are used as in-situ plasma diagnostic techniques in three separate studies of plasma etching: Investigations of the conditions which cause, and the mechanism of, the roughening of Si(100) when using Cl2 plasmas; studies of triode-mode etching of Si(100) and SiO2 using both Cl2 and SF6 plasmas; experimental and theoretical studies of the distribution of chemical species in SF6/O2 plasmas over Si(100) and SiO2. (orig.)

97

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

International Nuclear Information System (INIS)

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

98

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

International Nuclear Information System (INIS)

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

99

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

Directory of Open Access Journals (Sweden)

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

Liénard, A.

2014-01-01

100

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

Energy Technology Data Exchange (ETDEWEB)

Pigging of long pipelines is a technique for in situ (field) coating, creating seamless internal structural linings. Originally developed for cleaning pipes, the system was adapted to apply internal anti-corrosion protection to pipes using a thin epoxy layer, which had some problems in weld coverage, stress cracking, poor cold weather curing and the inability to fill pitting corrosion metal loss. New coating materials, revised application methods and modified pigging equipment have made it possible to apply in situ liquid film coatings up to 1 mm thick, as an internal corrosion barrier to pipes, in a single application (similar to continuous screeding) resulting in a bonded 'GRP pipe within a steel pipe'. The method can be used for new projects on fully welded pipe lines avoiding coating problems associated with flange joints and/or couplings, or for refurbishment of old pipelines, varying from 150-900 mm diameter, up to 12 km long. Pipes can be buried, submerged, continuously welded or flanged. Many different pipes, such as oil platform to shore based pipelines, can all be treated using this method. Thick film polymer pigging techniques create new possibilities for Engineers to extend the life of pipeline systems, with significant cost savings compared to replacement pipe. (author)

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

2005-07-01

101

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

Energy Technology Data Exchange (ETDEWEB)

The science and technology of ferroelectric thin films has experienced an explosive development during the last ten years. Low-density non-volatile ferroelectric random access memories (NVFRAMs) are now incorporated in commercial products such as ''smart cards'', while high permittivity capacitors are incorporated in cellular phones. However, substantial work is still needed to develop materials integration strategies for high-density memories. We have demonstrated that the implementation of complementary in situ characterization techniques is critical to understand film growth and interface processes, which play critical roles in film microstructure and properties. We are using uniquely integrated time of flight ion scattering and recoil spectroscopy (TOF-ISARS) and spectroscopic ellipsometry (SE) techniques to perform in situ, real-time studies of film growth processes in the high background gas pressure required to growth ferroelectric thin films. TOF-ISARS provides information on surface processes, while SE permits the investigation of buried interfaces as they are being formed. Recent studies on SrBi{sub 2}Ta{sub 2}O{sub 9} (SBT) and Ba{sub x}Sr{sub 1{minus}x}TiO{sub 3} (BST) film growth and interface processes are discussed.

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

1999-08-30

102

N-isopropylacrylamide-based fine-dispersed thermosensitive ferrogels obtained via in-situ technique.  

Science.gov (United States)

Thermosensitive hydrogels with magnetic properties (ferrogels) are very promising for medical application, first of all, for the design of targeted delivery systems with controlled release of drugs and for magnetic hyperthermia and chemotherapy treatment of cancer. These magnetic hydrogels could be obtained using diverse techniques: ex- and in-situ syntheses. The present work is devoted to the study of magnetite (Fe3O4) formation inside the nanoreactors of (co)polymeric hydrogels. Polymeric templates (hydrogel films and fine-dispersed hydrogels) used for obtaining ferrogels were based on acrylic monomers: thermosensitive N-isopropylacrylamide, and hydrophilic acrylamide. Covalent cross-linking was accomplished using bifunctional monomer N,N'-methylenebisacrylamide. Influence of hydrophilic-lipophilic balance of polymeric templates and concentration of iron cations on the magnetite formation were investigated along with the development of ferrogel preparation technique. Cytotoxicity, physical and chemical properties of obtained magnetic hydrogels have been studied in this work. PMID:25427503

Korotych, O; Samchenko, Yu; Boldeskul, I; Ulberg, Z; Zholobak, N; Sukhodub, L

2013-03-01

103

Multifilamentary, in situ route, Cu-stabilized MgB2 strands  

International Nuclear Information System (INIS)

Transport critical current densities and n-values were measured at 4.2 K in fields up to 15 T on 7-, 19-, and 37-stack multifilamentary MgB2 strands made using an in situ route. Some strands included SiC additions (particle size ?30 nm), while in others Mg-rich compositions were used. Two basic multifilamentary variants were measured; the first had Nb filamentary barriers, the second had Fe filamentary barriers. All samples incorporated stabilizer in the form of Cu 101. Simple, one-step heat treatments were used, with temperatures ranging from 700 to 800 0C, and times from 10 to 30 min. Transport critical current densities of 1.75 x 105 A cm-2 were seen at 4.2 K and 5 T in 37-stack strands. One metre segments of strand were also measured at 4.2 K; these showed critical current densities of 6 x 105 A cm-2 at zero field. Magnetic Jcs of 37-stack strands were measured; these measurements showed that the intrinsic Jc of the material reached 106 A cm-2 at 20 K

104

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

International Nuclear Information System (INIS)

This paper presents field applications for two innovative grouting agents that were used to in situ stabilize buried waste sites, via jet grouting. The two grouting agents include paraffin and a proprietary iron oxide based cement grout called TECT. These materials were tested in specially designed cold test pits that simulate buried transuranic waste at the Idaho National Engineering Laboratory (INEL). The field demonstrations were performed at the INEL in an area referred to as the Cold Test Pit, which is adjacent to the INEL Radioactive Waste Management Complex (RWMC). At the RWMC, 56,000 m3 of transuranic (TRU) waste is co-mingled with over 170,000 m3 of soil in shallow land burial. Improving the confinement of this waste is one of the options for final disposition of this waste. Using jet-grouting technology to inject these materials into the pore spaces of buried waste sites results in the creation of buried monolithic waste forms that simultaneously protect the waste from subsidence, while eliminating the migratory potential of hazardous and radioactive contaminants in the waste

105

Novel, in-situ Raman and fluorescence measurement techniques: Imaging using optical waveguides  

Science.gov (United States)

The following dissertation describes the development of methods for performing standoff and in- situ Raman and fluorescence spectroscopy for chemical imaging and non-imaging analytical applications. The use of Raman spectroscopy for the in- situ identification of crack cocaine and cocaine.HCl using a fiberoptic Raman probe and a portable Raman spectrograph has been demonstrated. We show that the Raman spectra of both forms of cocaine are easily distinguishable from common cutting agents and impurities such as benzocaine and lidocaine. We have also demonstrated the use of Raman spectroscopy for in-situ identification of drugs separated by thin layer chromatography. We have investigated the use of small, transportable, Raman systems for standoff Raman spectroscopy (e.g. liquid crystal tunable filters (LCTF) are being used both with, and in place of dispersive spectrographs and fixed filtering devices. In addition, we improved the flexibility of the system by the use of a modified holographic fiber-optic probe for light and image collection. A comparison of tunable filter technologies for standoff Raman imaging is discussed along with the merits of image transfer devices using small diameter image guides. A standoff Raman imaging system has been developed that utilizes a unique polymer collection mirror. The techniques used to produce these mirrors make it easy to design low f/# polymer mirrors. The performance of a low f/# polymer mirror system for standoff Raman chemical imaging has been demonstrated and evaluated. We have also demonstrated remote Raman hyperspectral imaging using a dimension-reduction, 2-dimensional (2-D) to 1-dimensional (1-D), fiber optic array. In these studies, a modified holographic fiber-optic probe was combined with the dimension-reduction fiber array for remote Raman imaging. The utility of this setup for standoff Raman imaging is demonstrated by monitoring the polymerization of dibromostyrene. To further demonstrate the utility of in- situ spectral imaging, we have shown that small diameter (350 ?m) image guides can be used for in-situ measurements of analyte transport in thin membranes. This has been applied to the measurement of H2O diffusion in Nafion™ membranes using the luminescent compound, [Ru(phen)2dppz] 2+, which is a H2O indicator.

Carter, Jerry Chance

106

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

Energy Technology Data Exchange (ETDEWEB)

The goal of these projects was to develop molecule tools to tract the metabolic activity and physiological status of microorganisms during in situ uranium bioremediation. Such information is important in able to design improved bioremediation strategies. As summarized below, the research was highly successful with new strategies developed for estimating in situ rates of metabolism and diagnosing the physiological status of the predominant subsurface microorganisms. This is a first not only for groundwater bioremediation studies, but also for subsurface microbiology in general. The tools and approaches developed in these studies should be applicable to the study of microbial communities in a diversity of soils and sediments.

Lovley, Derek R

2012-11-28

107

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

Directory of Open Access Journals (Sweden)

Full Text Available The dynamic response test to the subgrade plays a very important role in railway construction and a new in-situ test system is proposed. This paper presents the application of non-dominated sorting genetic algorithm-II (NSGA-II to analyze the stability of the supporting equipment for track subgrade dynamic response in-situ test device. Its stability is related with the extension length of the hydraulic cylinders and the backward condition of the supporting equipment - the hydraulic excavator. The problem is formulated as a multi-objective optimization problem with the objective of maximizing  the supporting force for the test device. An 85 tons excavator is picked as the case to study. The first optimal results show the excavator may not support the test system successfully. After redesigning the boom and adding its weight and length as new parameters, the second optimize results indicate the test device can work normally.

Feilong Zheng

2013-07-01

108

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

International Nuclear Information System (INIS)

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

109

In-situ health monitoring technique for composite structures utilizing embedded thermal fiber optic sensors  

Science.gov (United States)

Health monitoring techniques are necessary for the safety, reliability and longevity of structural components. However, dependable, in-situ, and practical damage detection methods are difficult to develop and implement. In this dissertation, a novel health monitoring technique based on thermography that uses optical fiber thermal sensors to detect damage within a laminated graphite epoxy composite specimen is investigated. The concept follows: when an internal defect exists inside a composite panel and an external heat flux is applied, the defect can hinder the heat from propagating through the panel. Consequently, thermal sensors placed near the defect measure a temperature change when compared to a defect-free panel. Fiber optic sensors are permanently embedded within a structure to allow for direct temperature measurement and an in-situ health monitoring technique. Fiber optic sensors are advantageous primarily due to their multiplexing capabilities. Certain fiber optic technologies permit 1000 point sensors on a single fiber, which in turn reduces the cabling sizes by three orders of magnitude. A comprehensive proof-of-concept study involved five sets of composite samples and a numerical model. The first set validated the concept, the second tested two types of fiber optic sensors, the third provided a thorough study using the superior sensor technology, the fourth provided data to develop a numerical model, and the last set validated the model's findings. The numerical model provided a close approximation to the experimental data, and was used to determine proper sensor placement. The first three sets of specimens used a simulated impact system to induce damage of varying degrees into the samples. The last two sets used artificial damage in the form of Teflon inserts in an effort to quantify the size and location of damage. A flash lamp apparatus rapidly heated the samples while the fiber optic sensors and exterior thermocouples recorded temperature changes. Results confirm that the fiber optic thermal sensors can detect the presence and severity of damage.

Stewart, Anna Kristina

110

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

International Nuclear Information System (INIS)

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

111

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

International Nuclear Information System (INIS)

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

112

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

DEFF Research Database (Denmark)

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

Kaiser, Andreas; Prasad, A.S.

2013-01-01

113

In situ tagging technique for fishes provides insight into growth and movement of invasive lionfish.  

Science.gov (United States)

Information on fish movement and growth is primarily obtained through the marking and tracking of individuals with external tags, which are usually affixed to anesthetized individuals at the surface. However, the quantity and quality of data obtained by this method is often limited by small sample sizes owing to the time associated with the tagging process, high rates of tagging-related mortality, and displacement of tagged individuals from the initial capture location. To address these issues, we describe a technique for applying external streamer and dart tags in situ, which uses SCUBA divers to capture and tag individual fish on the sea floor without the use of anesthetic. We demonstrate this method for Indo-Pacific lionfish (Pterois volitans/P. miles), species which are particularly vulnerable to barotrauma when transported to and handled at the surface. To test our method, we tagged 161 individuals inhabiting 26 coral reef locations in the Bahamas over a period of 3 years. Our method resulted in no instances of barotrauma, reduced handling and recovery time, and minimal post-tagging release displacement compared with conventional ex situ tag application. Opportunistic resighting and recapture of tagged individuals reveals that lionfish exhibit highly variable site fidelity, movement patterns, and growth rates on invaded coral reef habitats. In total, 24% of lionfish were resighted between 29 and 188 days after tagging. Of these, 90% were located at the site of capture, while the remaining individuals were resighted between 200 m and 1.1 km from initial site of capture over 29 days later. In situ growth rates ranged between 0.1 and 0.6 mm/day. While individuals tagged with streamer tags posted slower growth rates with increasing size, as expected, there was no relationship between growth rate and fish size for individuals marked with dart tags, potentially because of large effects of tag presence on the activities of small bodied lionfish (i.e., fish site fidelity, movement patterns, and growth in cases where ex situ tagging is not feasible. PMID:25614791

Akins, John L; Morris, James A; Green, Stephanie J

2014-10-01

114

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-05-10

115

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

Science.gov (United States)

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

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

2013-12-01

116

In situ superconducting MgB2 films grown by co-evaporation technique  

International Nuclear Information System (INIS)

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

117

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

International Nuclear Information System (INIS)

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

118

High temperature in-situ observations of multi-segmented metal nanowires encapsulated within carbon nanotubes by in-situ filling technique  

OpenAIRE

Multi-segmented one-dimensional metal nanowires were encapsulated within carbon nanotubes (CNTs) through in-situ filling technique during plasma-enhanced chemical vapor deposition process. Transmission electron microscopy (TEM) and environmental TEM were employed to characterize the as-prepared sample at room temperature and high temperature. The selected area electron diffractions revealed that the Pd4Si nanowire and face-centered-cubic Co nanowire on top of the Pd nanowire were encapsulated...

Hayashi, Yasuhiko; Tokunaga, Tomoharu; Iijima, Toru; Iwata, Takuya; Kalita, Golap; Tanemura, Masaki; Sasaki, Katsuhiro; Kuroda, Kotaro

2012-01-01

119

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

International Nuclear Information System (INIS)

In this study, we combined chlorophyll a fluorescence (ChlaF) measurements, using pulse-amplitude-modulate (PAM) equipment, with scanning electron microscopy in backscattered electron mode (SEM-BSE) and transmission electron microscopy (TEM) images to evaluate the actions of Koretrel at lower concentrations on Verrucaria nigrescens colonising a dolostone. ChlaF measurements are good indicators of the damaging effects of biocides. However, these indicators only provide an incomplete view of the mechanism of biocides used to control biodeterioration agents. The death of the V. nigrescens photobiont at two biocide concentrations was revealed by PAM, SEM-BSE and TEM. Once Koretrel was applied, the Fv/Fm ratios markedly fell in the first few hours after the 1.5% treatment, and ratios for the 3% dilution remained close to zero throughout the study. The algal zone shows the plasmolysed appearance of the photobiont cells, and important aspects related to the action of the biocide on free and lichenised fungi were also detected using SEM-BSE. Many of the mycobiont cells had only their cell walls preserved; although, some fungal hyphae in lichen thalli and some microorganisms in endolithic clusters maintained lipid storage in their cytoplasm. These results indicated that the combination of physiological and microscopy techniques improves the assessment of biocide action in situ and this will help to optimize protocols in order to reduce the emission of these compounds to the environment. -- Highlights: ? We combined ChlaF measurements with EM images to analyses the biocides action on stone biodeterioration agents. ? At lower biocide concentrations damage to photobiont and mycobiont cells integrity, ultrastructure and vitality were observed. ? The limited action of biocides on fungi and algae were detected using SEM-BSE. ? The combination of physiological and microscopy techniques improves the assessment of biocide action in situ. ? This new approach will help to optimize protocols of biocide application on stone.

120

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

Directory of Open Access Journals (Sweden)

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

C. Hak

2005-01-01

121

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

Directory of Open Access Journals (Sweden)

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

C. Hak

2005-05-01

122

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

International Nuclear Information System (INIS)

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

123

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1980-12-01

124

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

International Nuclear Information System (INIS)

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

125

In-situ simultaneous measurement of temperature and thin film thickness with ultrasonic techniques  

Science.gov (United States)

We describe a novel technique to measure in situ, simultaneously, temperature and thin film thickness during semiconductor processing. The measurement is based on the principle that the velocity of an ultrasonic Lamb wave propagating in a silicon wafer is a function of both the wafer temperature and the thin film coating on the wafer surface. Because sensitivities of Lamb wave velocity to temperature and film thickness change differently with frequency, with a simple linear inversion method, we are able to obtain both the processing temperature an film thickness simultaneously with two sets of sensors operating at two distinct frequencies, 0.5MHz and 1.5MHz. This technique is demonstrated in an aluminum sputtering system. We have achieved a temperature measurement accuracy of +/- 0.15 degree C and an aluminum film thickness resolution of +/- 170 angstrom. The measurement does not depend on the optical or the electrical properties of either the wafer or the film materials, and is insensitive to the processing environment. With its high measurement accuracy and setup simplicity, this sensor system carries great potential in semiconductor process monitoring and control.

Khuri-Yakub, Butrus T.; Pei, Jun; Degertekin, F. Levent; Saraswat, Krishna C.

1996-11-01

126

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

International Nuclear Information System (INIS)

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

127

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

International Nuclear Information System (INIS)

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

128

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

Energy Technology Data Exchange (ETDEWEB)

Nanocomposite of poly (styrene-co-vinyl acetate) (PSV)/CdS was prepared by the in situ simultaneous copolymerization-sulfidation technique with CS{sub 2} as the sulfur source through the hydrothermal process. The obtained materials were characterized by FT-IR, XRD, TEM, ultraviolet-visible and fluorescence spectroscopy.

Liu, S.H.; Qian, X.F.; Yin, J.; Xi, H.A.; Huang, Z.H.; Zhu, Z.K

2003-03-15

129

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

International Nuclear Information System (INIS)

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

130

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

International Nuclear Information System (INIS)

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

131

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

Energy Technology Data Exchange (ETDEWEB)

In this study, we combined chlorophyll a fluorescence (ChlaF) measurements, using pulse-amplitude-modulate (PAM) equipment, with scanning electron microscopy in backscattered electron mode (SEM-BSE) and transmission electron microscopy (TEM) images to evaluate the actions of Koretrel at lower concentrations on Verrucaria nigrescens colonising a dolostone. ChlaF measurements are good indicators of the damaging effects of biocides. However, these indicators only provide an incomplete view of the mechanism of biocides used to control biodeterioration agents. The death of the V. nigrescens photobiont at two biocide concentrations was revealed by PAM, SEM-BSE and TEM. Once Koretrel was applied, the Fv/Fm ratios markedly fell in the first few hours after the 1.5% treatment, and ratios for the 3% dilution remained close to zero throughout the study. The algal zone shows the plasmolysed appearance of the photobiont cells, and important aspects related to the action of the biocide on free and lichenised fungi were also detected using SEM-BSE. Many of the mycobiont cells had only their cell walls preserved; although, some fungal hyphae in lichen thalli and some microorganisms in endolithic clusters maintained lipid storage in their cytoplasm. These results indicated that the combination of physiological and microscopy techniques improves the assessment of biocide action in situ and this will help to optimize protocols in order to reduce the emission of these compounds to the environment. -- Highlights: Black-Right-Pointing-Pointer We combined ChlaF measurements with EM images to analyses the biocides action on stone biodeterioration agents. Black-Right-Pointing-Pointer At lower biocide concentrations damage to photobiont and mycobiont cells integrity, ultrastructure and vitality were observed. Black-Right-Pointing-Pointer The limited action of biocides on fungi and algae were detected using SEM-BSE. Black-Right-Pointing-Pointer The combination of physiological and microscopy techniques improves the assessment of biocide action in situ. Black-Right-Pointing-Pointer This new approach will help to optimize protocols of biocide application on stone.

Speranza, M., E-mail: speranzamariela@gmail.com [Museo Nacional de Ciencias Naturales, MNCN-CSIC, Serrano 115 bis, 28006 Madrid (Spain); Wierzchos, J.; De Los Rios, A.; Perez-Ortega, S. [Museo Nacional de Ciencias Naturales, MNCN-CSIC, Serrano 115 bis, 28006 Madrid (Spain); Souza-Egipsy, V. [Instituto de Ciencias Agrarias, ICA-CSIC, Serrano 115 bis, 28006 Madrid (Spain); Ascaso, C., E-mail: ascaso@mncn.csic.es [Museo Nacional de Ciencias Naturales, MNCN-CSIC, Serrano 115 bis, 28006 Madrid (Spain)

2012-11-15

132

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

International Nuclear Information System (INIS)

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

133

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

International Nuclear Information System (INIS)

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

134

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

International Nuclear Information System (INIS)

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

135

Novel stability criteria for fuzzy Hopfield neural networks based on an improved homogeneous matrix polynomials technique  

Science.gov (United States)

The global stability problem of Takagi—Sugeno (T—S) fuzzy Hopfield neural networks (FHNNs) with time delays is investigated. Novel LMI-based stability criteria are obtained by using Lyapunov functional theory to guarantee the asymptotic stability of the FHNNs with less conservatism. Firstly, using both Finsler's lemma and an improved homogeneous matrix polynomial technique, and applying an affine parameter-dependent Lyapunov—Krasovskii functional, we obtain the convergent LMI-based stability criteria. Algebraic properties of the fuzzy membership functions in the unit simplex are considered in the process of stability analysis via the homogeneous matrix polynomials technique. Secondly, to further reduce the conservatism, a new right-hand-side slack variables introducing technique is also proposed in terms of LMIs, which is suitable to the homogeneous matrix polynomials setting. Finally, two illustrative examples are given to show the efficiency of the proposed approaches.

Feng, Yi-Fu; Zhang, Qing-Ling; Feng, De-Zhi

2012-10-01

136

Synthesis of magnesia stabilized zirconia by co-precipitation technique  

International Nuclear Information System (INIS)

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

137

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-10-15

138

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

International Nuclear Information System (INIS)

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

139

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

International Nuclear Information System (INIS)

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

140

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1999-01-01

141

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1999-07-01

142

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1999-09-01

143

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english AIM: This study evaluated saliva effects on enamel morphology surface after microabrasion technique. METHODS: Enamel blocks (16 mm2) obtained from bovine incisors were divided into 9 groups as follows: one control group (no treatment), four groups with microabrasion treatment using 35% phospho [...] ric acid and pumice (H3PO4+Pum) and other four groups treated with 6.6% hydrochloric acid and silica (HCl+Sil). One group of each treatment was submitted to 4 frames of saliva exposure: without exposure, 1-h exposure, 24-h exposure, and 7-days exposure on in situ regimen. Nineteen volunteers (n=19), considered as statistical blocks, used an intraoral appliance containing the specimens, for 7 days. Enamel roughness (Ra) was tested before and after treatment, and after saliva exposure. Confocal laser scanning microscopy (CLSM) was used to evaluate qualitatively the enamel morphology. RESULTS: All groups exhibited increased Ra after microabrasion. With regards to saliva exposure, the treatment with HCl+Sil presented more susceptibility to the saliva action, but no period of time was efficient in re-establishing this characteristic compared with the control group. CLSM analysis showed reduction of the micro-abrasive damages during the experimental times. CONCLUSIONS: Seven days of saliva exposure were not sufficient for the treated enamel to reach its normal characteristics compared with the control group.

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

2014-09-01

144

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2000-01-01

145

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

International Nuclear Information System (INIS)

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

146

Kinetics of chloride ion adsorption on stainless alloys by in situ contact electric resistance technique  

International Nuclear Information System (INIS)

As the primary reason for pitting of stainless alloys, chloride adsorption is not adequately studied, e.g. kinetic investigations of chloride adsorption are actually absent. We discuss and partly reconsider some well-known facts (e.g. halides order: Cl- > Br- > I-), disputed points (chloride penetration in passive film), and still unknown aspects of chloride adsorption. For the first time, we report kinetic studies of chloride adsorption on stainless alloys by in situ contact electric resistance technique. The peak-like character of kinetic curves has been found for all studied stainless alloys, but not for pure iron and nickel. This has been considered as a sequence of the substantial charge transfer during chloride adsorption. Opposite to typical d metals, stainless materials are alloys of early and late transition metals having unfilled d-bands with increased number of d-electron vacancies. Such electronic structure is favorable for adsorption of electron donating adsorbates like halide ions. Experimental data of this work are more compatible with possibility of chloride penetration into the passive films on stainless alloys that also might involve a transformation of primary oxy-hydroxide films into oxy-chloride films

147

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

Energy Technology Data Exchange (ETDEWEB)

We investigate the thermal stability of nearly lattice-matched InAlN layers under metal organic vapor phase epitaxy conditions for temperatures >800?°C and show that they are not fully stable. In particular, InAlN top layers undergo degradation during high temperature annealing due to a surface related process, which causes the loss of crystal quality. This strongly impacts the transport properties of InAlN/GaN HEMT heterostructures; in particular, the mobility is significantly reduced. However, we demonstrate that high thermal stability can be achieved by capping with a GaN layer as thin as 0.5?nm. Those findings enabled us to realize in situ passivated HEMT heterostructures with state of the art transport properties.

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

2014-09-15

148

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1991-11-01

149

Use of noninvasive geophysical techniques for the in situ vitrification program  

Energy Technology Data Exchange (ETDEWEB)

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

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

1991-11-01

150

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

Science.gov (United States)

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

Villanueva, Alex A.; Priya, Shashank

2014-01-01

151

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

Science.gov (United States)

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

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

2014-05-01

152

Stabilization techniques in finite element discretizations for moment approximations  

Science.gov (United States)

The paper is concerned with the discretization of a linearized subsystem of the regularized 13-moment equations. These equations state an approximation of the Boltzmann equation as a result of applying moment methods. First, the derivation of the linearized equations is outlined, followed by the introduction of the numerical approach. The subsystem is of elliptic nature which makes finite elements the method of choice. The handling of saddle-point structures within the equations and non-standard boundary conditions are discussed. In this context, the concept of stabilization is presented and applied to the specific problem.

Westerkamp, Armin; Torrilhon, Manuel

2014-12-01

153

Dimensional stability of a novel polyvinyl siloxane impression technique  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english AIM: To introduce a modification of the reline impression technique (MRIT), and compare the dimensional changes of impressions obtained by MRIT and by conventional reline impression technique (CRIT). METHODS: An acrylic resin tablet was milled by a CAD-CAM system to simulate three abutments (A [...] , B and C) with different distances among them. The abutments were molded using both impression techniques. For MRIT, before completing the putty silicone polymerization, the relieve procedure was made by compression and it was immediately repositioned to complete the polymerization. Impressions were stored dry at room temperature for different periods (immediately, 1 h, 2 days and 7 days). The distances were obtained by scanning. The differences between the impressions and their respective matrix reference measurements were calculated to determine the dimensional changes. Data were subjected to ANOVA and Tukey's test (p

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

2014-04-01

154

Assessment of slope stability using PS-InSAR technique  

Science.gov (United States)

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

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

2014-11-01

155

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

Directory of Open Access Journals (Sweden)

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

Besharati Maghsoud

2008-01-01

156

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

International Nuclear Information System (INIS)

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

157

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

International Nuclear Information System (INIS)

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

158

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2014-02-15

159

Stabilization of frictional soil through injection using CIPS (Calcite In-situ Precipitation System)  

OpenAIRE

The precipitation system CIPS (Calcite In-situ Precipitation System) has been created as a permeation grouting system based on a two component fluid with the intention of slowly permeate and fill the pores. It causes cementation through a chemical reaction which bonds the soil particles together at the contact points. CIPS mimics one of the natural reactions in nature where sandstone is formed through calcite precipitation. This system is used in Australia with excellent results and there are...

Palme?n, Anders

2012-01-01

160

An optimization technique of robust load frequency stabilizer for superconducting magnetic energy storage  

International Nuclear Information System (INIS)

As an interconnected power system is subjected to rapid load disturbances with changing frequencies in the vicinity of the inter-area oscillation mode, a system frequency may be heavily disturbed and oscillate. Under the circumstances, the stabilizing effect of the conventional load frequency control (LFC), i.e. a governor, cannot be expected. To compensate for such load disturbances and stabilize frequency oscillations, the active power controlled by superconducting magnetic energy storage (SMES) can be applied. In this paper, a new optimization technique of a robust load frequency stabilizer equipped with SMES is presented. To enhance the robustness of the load frequency stabilizer against system uncertainties such as various load changes, system parameters variations etc., the multiplicative uncertainty is included in the system modeling. As a result, the robust stability of the stabilized system can be easily guaranteed in terms of the multiplicative stability margin (MSM). The configuration of the load frequency stabilizer is practically based on a second order lead/lag compensator with a single feedback input. The control parameters are automatically optimized by a tabu search algorithm, so that the desired damping ratio of the target inter-area mode and the best MSM are achieved. The simulation study exhibits the high robustness of the load frequency stabilizer against uncertainties. Moreover, a SMES unit requires small power capacity for frequency stabilizatio power capacity for frequency stabilization

161

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

Science.gov (United States)

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

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

162

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

OpenAIRE

In this paper, Polyimide/Montmorillonite Nanocomposites (PI/MMT NCs), based on aromatic diamine (4-Aminophenyl sulfone) (APS) and aromatic dianhydride (3,3?,4,4?-benzophenonetetracarboxylic dianhydride) (BTDA) were prepared using in situ polymerization and solution-dispersion techniques. The prepared PI/MMT NCs films were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). T...

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

2011-01-01

163

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

Science.gov (United States)

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

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

1998-01-01

164

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

Scientific Electronic Library Online (English)

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

Raúl, Rodríguez Martínez.

2011-12-01

165

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

International Nuclear Information System (INIS)

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

166

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

Scientific Electronic Library Online (English)

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

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

167

Synthesis and high-temperature stability of titanium aluminide matrix in situ composites  

Science.gov (United States)

A premixture of elemental powders of titanium and aluminum was supplied as a spray material for the direct fabrication of titanium aluminide matrix in situ composites by means of reactive low-pressure plasma spraying with a nitrogen and hydrogen mixed plasma gas. The aluminum content varied from 10 to 63 wt.% in the premixtures. The matrix of sprayed layers consisted of three kinds of titanium aluminides—Ti3A1, TiAl, and TiAl3—which begin to form on a low-carbon steel substrate immediately after deposition. The formation of nitrides, which act as a reinforcement, occurs both during the flight of liquid droplets and on the substrate. The nitrogen content is approximately 4 to 5 wt.% in the sprayed intermetallic matrix composites, regardless of the aluminum content of the premixtures. The kinds of titanium aluminides and in situ nitrides developed depend on the aluminum content of the premixtures. The homogeneity of the distribution of aluminum and titanium in sprayed intermetallic matrix composites has been improved by vacuum annealing. The predominant TiAl phase that formed in the sprayed intermetallic matrix composites with a Ti-36 wt.% AI premixture increases in quantity through annealing. Although some minor nitrides disappear through annealing, the principal reinforcement, Ti2AlN, does not decompose, but increases in quantity. The hardness of sprayed intermetallic matrix composites varies with aluminum content of the premixtures, but is always greater than that of sprayed titanium aluminides containing no nitrides. Annealing does not reduce the hardness of sprayed intermetallic matrix composites. Sprayed and annealed intermetallic matrix composites with a Ti-36 wt.% Al premixture maintain their hardness of approximately 500 HV up to 800 K. Hence, reactive low-pressure plasma spraying offers a promising fabrication method for titanium aluminide matrix in situ composites, which are expected to excel in wear resistance applications at elevated temperatures.

Tsunekawa, Y.; Gotoh, K.; Okumiya, M.; Mohri, N.

1992-09-01

168

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

Energy Technology Data Exchange (ETDEWEB)

Toxic effects of artificial radionuclides are strongly dependent on the surrounding chemical environment which determines the bioavailability of contaminant species. Speciation of plutonium in the environment is of particular interest since it is a long-life actinide contributing to the dose exposure via ingestion with water and food in case of radioactive discharge. Furthermore, natural colloids present in waters, as main carriers of dissolved trace metals, can transport plutonium over significant distances from contaminated sites. The diffusive gradients in thin films (DGT) technique is an efficient instrument for passive sampling of trace metals. It allows for in-situ monitoring of mean concentrations of bioavailable contaminant species (1). A DGT sampler consists of two gel layers: a polyacrylamide hydrogel diffusion layer allowing to diffuse labile metal species to the second, binding layer, impregnated with ion-exchange resin. Resin elution and further analysis allow determining the amount of the bioavailable fraction of trace metals in the bulk solution, which can be calculated from the relationship: C{sub bulk}= (M x ?g)/(D x t x A) where M is the measured metal species inventory in the resin, ?g the thickness of the diffusion layer, D the diffusion coefficient of the species in the gel, t the time of deployment, A the diffusion area. To our knowledge, the DGT has not yet been applied for Pu speciation measurements and the D value is unknown. Here we propose the use of DGT to monitor the dissolved phase and labile complexes of plutonium in the aquatic environment. We have first measured the diffusion coefficient of plutonium in the hydrogel. Experiments were carried out in a diffusion cell (2) and with commercially available DGT samplers exposed in standardized solutions containing {sup 239}Pu at pico-molar concentrations. Both approaches give comparable D values in the range of 2.30 x 10{sup -6} - 2.45 x 10{sup -6} cm{sup 2} s{sup -1}. We then studied plutonium diffusion in the presence of naturally occurring ligands - fulvic and humic acids - and in natural waters sampled at a mineral spring and an organic-rich brook of a karst system in the Swiss Jura Mountains, in which the increased mobility of {sup 239+240}Pu compared to {sup 241}Am and {sup 137}Cs has been recently observed (3). Diffusion experiments in simulated natural conditions show different mobility of the radionuclide in fresh waters with different DOM content, supporting the idea that the speciation of plutonium and the abundance of free ionic form in particular, are of prime importance to better estimate the bioavailability and the toxicity of plutonium. (authors)

Cusnir, R.; Bochud, F.; Froidevaux, P. [Institute of Radiation Physics, Lausanne University Hospital, Rue du Grand-Pre 1, CH-1007 Lausanne (Switzerland); Steinmann, P. [Federal Office of Public Health, Swarzenburgstrasse 165, CH-3003 Bern (Switzerland)

2014-07-01

169

Stability analysis of abnormal multiplication of plankton using parameter identification technique  

Science.gov (United States)

This paper presents the mathematical approach for the abnormal multiplication of plankton. An abnormal multiplication can be expressed as an unstable problem and the stability of the system is investigated by introducing eigenvalues of a mathematical equation. The stability of the system can be judged by an eigenvalue based on the Lyapunov's stability theory. In this paper, the Arnoldi-QR method is used to obtain eigenvalues and eigenvectors of the system. The mode superposition method is employed to create spatial distribution needed to analyse the stability. To obtain the objective eigenvalue, the parameter identification technique is employed. The finite element method is used for the discretization in space. Lake Kasumigaura, which is located in Ibaraki Prefecture in Japan, is selected and actual data in 1975, 1976, 1991 and 2000 are used in order to investigate the stability of the specified lake in Japan.

Ohno, G.; Kawahara, M.

2004-01-01

170

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

International Nuclear Information System (INIS)

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

171

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

Directory of Open Access Journals (Sweden)

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

M. Rostami

2011-05-01

172

Critical technical issues associated with impedance match based voltage stability monitoring techniques  

Energy Technology Data Exchange (ETDEWEB)

In response to economic and environmental constraints, power systems are being operated closer to their limits. The limiting factor for power transmission is the risk of voltage instability. Some critical technical issues associated with impedance match based voltage stability monitoring techniques were discussed in this presentation. Specifically, the presentation discussed technical issues associated with single-port impedance match based voltage stability monitoring as well as a proposed multi-port impedance match method. Simulation results of the proposed methods were also offered. Applications of the proposed method include identifying the critical buses and estimating voltage stability margin. Implementation logistics were discussed and conclusions were presented. tabs., figs.

Wang, Y. [Alberta Univ., Edmonton, AB (Canada). Dept. of Electrical and Computer Engineering

2009-07-01

173

FEASIBILITY OF IN SITU SOLIDIFICATION/STABILIZATION OF LANDFILLED HAZARDOUS WASTES  

Science.gov (United States)

This report discusses the feasibility of solidifying or stabilizing hazardous industrial wastes that are already in place at a landfill. Solidification methods considered include (1) incorporating the waste into solids, (2) fusing the waste with soil, and (3) isolating the waste ...

174

IMPROVED FLOTATION TECHNIQUE FOR MICROSCOPY OF 'IN SITU' SOIL AND SEDIMENT MICROORGANISMS  

Science.gov (United States)

An improved flotation method for microscopical examination of in situ soil and sediment microorganisms was developed. Microbial cells were released into gel-like flotation films that were stripped from soil and sediment aggregates as these aggregates were submerged in 0.5% soluti...

175

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

OpenAIRE

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

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

2009-01-01

176

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

Energy Technology Data Exchange (ETDEWEB)

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

Smentkowski, V. S.

1999-04-22

177

Structural changes and thermal stability of charged LiNixMnyCozO? cathode materials studied by combined in situ time-resolved XRD and mass spectroscopy.  

Science.gov (United States)

Thermal stability of charged LiNixMnyCozO2 (NMC, with x + y + z = 1, x:y:z = 4:3:3 (NMC433), 5:3:2 (NMC532), 6:2:2 (NMC622), and 8:1:1 (NMC811)) cathode materials is systematically studied using combined in situ time-resolved X-ray diffraction and mass spectroscopy (TR-XRD/MS) techniques upon heating up to 600 °C. The TR-XRD/MS results indicate that the content of Ni, Co, and Mn significantly affects both the structural changes and the oxygen release features during heating: the more Ni and less Co and Mn, the lower the onset temperature of the phase transition (i.e., thermal decomposition) and the larger amount of oxygen release. Interestingly, the NMC532 seems to be the optimized composition to maintain a reasonably good thermal stability, comparable to the low-nickel-content materials (e.g., NMC333 and NMC433), while having a high capacity close to the high-nickel-content materials (e.g., NMC811 and NMC622). The origin of the thermal decomposition of NMC cathode materials was elucidated by the changes in the oxidation states of each transition metal (TM) cations (i.e., Ni, Co, and Mn) and their site preferences during thermal decomposition. It is revealed that Mn ions mainly occupy the 3a octahedral sites of a layered structure (R3?m) but Co ions prefer to migrate to the 8a tetrahedral sites of a spinel structure (Fd3?m) during the thermal decomposition. Such element-dependent cation migration plays a very important role in the thermal stability of NMC cathode materials. The reasonably good thermal stability and high capacity characteristics of the NMC532 composition is originated from the well-balanced ratio of nickel content to manganese and cobalt contents. This systematic study provides insight into the rational design of NMC-based cathode materials with a desired balance between thermal stability and high energy density. PMID:25420188

Bak, Seong-Min; Hu, Enyuan; Zhou, Yongning; Yu, Xiqian; Senanayake, Sanjaya D; Cho, Sung-Jin; Kim, Kwang-Bum; Chung, Kyung Yoon; Yang, Xiao-Qing; Nam, Kyung-Wan

2014-12-24

178

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

DEFF Research Database (Denmark)

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

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

2012-01-01

179

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

CERN Document Server

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

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

2015-01-01

180

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

Science.gov (United States)

We present new kinetics data on the radiolytic destruction of amino acids measured in situ with infrared spectroscopy. Samples were irradiated at 15, 100, and 140 K with D.8-MeV protons, and amino-acid decay was followed at each temperature with and without H2O present. Observed radiation products included CO2 and amines, consistent with amino-acid decarboxylation. The half-lives of glycine, alanine, and phenylalanine were estimated for various extraterrestrial environments. Infrared spectral changes demonstrated the conversion from the non-zwitterion structure NH2-CH2(R)-COOH at 15 K to the zwitterion structure +NH3-CH2(R)-COO- at 140 K for each amino acid studied.

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

2012-01-01

181

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

Energy Technology Data Exchange (ETDEWEB)

The Burrell Township site, located in western Pennsylvania, received approximately 11,600 tons of radioactively-contaminated material in late 1956 and early 1957 from the Vitro Manufacturing Company's operations in Canonsburg, Pennsylvania. WESTON was requested to conduct an engineering study to determine the feasibility of stabilizing the site in accordance with the US Environmental Protection Agency's (EPA) interim and proposed standards (45 FR 27366--27368, April 22, 1980, and 46 FR 2556--2563, January 9, 1981). The scope of this study is limited to those alternatives that can be implemented on the site and will not require removal and offsite disposal of radioactively-contaminated material. Four alternatives for control of the radioactive material at the Burrell site were considered and evaluated, as follows: 1. Site stabilization and closure. 2. Site control and containment. 3. Waste excavation and encapsulation. 4. Waste excavation, incineration, and encapsulation. 2 refs., 32 figs., 12 tabs.

1982-11-01

182

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

International Nuclear Information System (INIS)

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

183

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

Science.gov (United States)

Among the difficulties associated with multivariable, non-linear control systems is the problem of assessing closed-loop stability. Of particular interest is the class of non-linear systems controlled with on/off actuators, such as spacecraft thrusters or electrical relays. With such systems, standard describing function techniques are typically too conservative, and time-domain simulation analysis is prohibitively extensive, This paper presents an open-loop analysis technique for this class of non-linear systems. The technique is centered around an innovative use of multivariable signal transmission theory to quantify the plant response to worst case control commands. The technique has been applied to assess stability of thruster controlled flexible space structures. Examples are provided for Space Shuttle attitude control with attached flexible payloads.

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

2000-01-01

184

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

Directory of Open Access Journals (Sweden)

Full Text Available To control the power flow,for increasing the transmission capacity & for power system stability,FACT devices are used.Unified Power Flow Controller is most widely used. This paper presents a novelBacterial foraging technique (BFO for optimizing the PI controller parameters of UPFC for the transient stability enhancement of SMIB system .Complete modeling is done for SMIB system with UPFC controller.PI controller parameters computedbyconventional method [23] are usedas base for BFO, Bacterial Foraging Optimization Technique is applied for computing better optimized values.Results exhibit that BFO technique is able to find a better quality solution as compared to conventional technique for the proposed problem.

Poonam Singhal

2014-05-01

185

Influence of surgical technique, implant shape and diameter on the primary stability in cancellous bone.  

Science.gov (United States)

Achievement of primary stability during surgical placement of dental implants is one of the most important factors for successful osseointegration depending on various anatomical, surgical and implant-related factors. Resonance frequency analysis (RFA) has been shown as a non-invasive and objective technique for measuring the stability of implants. The aim of this study was to evaluate the effect of some surgical and implant-related factors in enhancing primary stability and to estimate a correlation between RFA and insertion torque (IT) in proximal regions of cow ribs representing cancellous bone. Fifteen implant beds were prepared in the most proximal region of six fresh cow ribs. Ninety implants with three different shapes and two different diameters were placed with two different surgical techniques, and the primary stability was compared using RFA and IT. Significantly higher RFA and IT values were achieved when under-dimensioned drilling was used as the surgical method (P<0·01); significantly higher IT values were obtained with the use of wider implants (P<0·01) and partially conical Astra Tech implants showed the highest IT values (P<0·01). When all the implants were considered, significant correlations between the IT and RFA values were noted (%40·6, P<0·05). Partially conical implants with a wide diameter to be placed with the modified surgical technique proposed appear to be useful in enhancing the primary stability in cancellous bone. PMID:20529176

Bilhan, H; Geckili, O; Mumcu, E; Bozdag, E; Sünbülo?lu, E; Kutay, O

2010-12-01

186

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2005-09-26

187

Studies of ferroelectric heterostructure thin films, interfaces, and device-related processes via in situ analytical techniques.  

Energy Technology Data Exchange (ETDEWEB)

The science and technology of ferroelectric thin films has experienced an explosive development during the last ten years. Low-density non-volatile ferroelectric random access memories (NVFRAMS) are now incorporated in commercial products such as ''smart cards'', while high permittivity capacitors are incorporated in cellular phones. However, substantial work is still needed to develop materials integration strategies for high-density memories. We have demonstrated that the implementation of complementary in situ characterization techniques is critical to understand film growth and device processes relevant to device development. We are using uniquely integrated time of flight ion scattering and recoil spectroscopy (TOF-ISARS) and spectroscopic ellipsometry (SE) techniques to perform in situ, real-time studies of film growth processes in the high background gas pressure required to growth ferroelectric thin films. TOF-ISARS provides information on surface processes, while SE permits the investigation of buried interfaces as they are being formed. Recent studies on SrBi{sub 2}Ta{sub 2}O{sub 9} (SBT) and Ba{sub x}Sr{sub 1{minus}x}TiO{sub 3} (BST) film growth and interface processes are discussed. Direct imaging of ferroelectric domains under applied electric fields can provide valuable information to understand domain dynamics in ferroelectric films. We discuss results of piezoresponse scanning force microscopy (SFM) imaging for nanoscale studies of polarization reversal and retention loss in Pb(Zr{sub x}Ti{sub 1{minus}x})O{sub 3} (PZT)-based capacitors. Another powerful technique suitable for in situ, real-time characterization of film growth processes and ferroelectric film-based device operation is based on synchrotrons X-ray scattering, which is currently being implemented at Argonne National Laboratory.

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

1999-06-29

188

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

International Nuclear Information System (INIS)

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

189

Impact of Delivery Techniques and Timing on Science from In-Situ Vehicles at Titan  

Science.gov (United States)

NASA and ESA are currently conducting studies of a potential collaborative flagship mission Titan, Enceladus, and the Saturn system. The Saturn mission study, named the "Titan Saturn System Mission" (TSSM) study until an official name is adopted, is a combination of the "Titan and Enceladus Mission" (TandEM) proposed to and accepted for study by ESA's Cosmic Vision 2015-25 Program, and restructurings of two NASA flagship mission concept studies performed in 2007, "Titan Explorer" and "Enceladus Explorer". The combined mission is reminiscent of the Cassini/Huygens (CH) collaboration. It would have a NASA Titan-orbiting element and one or more ESA in situ elements that could be carried to Titan by the NASA element. There are multiple architecture options for implementing such a mission, and those architectures influence the options for delivering and supporting the ESA in situ elements. For instance, the decision to launch all elements on one launch vehicle, or to launch the NASA and ESA elements separately, greatly influences the options for delivery timing. In turn, the suite of options for delivery and support (which go beyond timing), especially constraints on timing that arise from them, influence the science return expected from the in situ elements. If the common launch architecture is chosen there are five primary options for effecting delivery of the in situ elements, mostly tied to timing of the delivery: upon Saturn approach, just after Saturn orbit insertion (SOI), during pumpdown, just before Titan orbit insertion (TOI), and after TOI. Each carries implications for how much mass can be delivered, what locations on Titan can be targeted, and how much science data might be returned to Earth. For all the primary architectural options, the presentation will discuss the ramifications of these differences on the science to be achieved. This work is funded by NASA.

Spilker, Thomas R.; Strange, N. J.; TSSM Study Team

2008-09-01

190

In Situ Stability of Substrate-Associated Cellulases Studied by DSC  

DEFF Research Database (Denmark)

This work shows that differential scanning calorimetry (DSC) can be used to monitor the stability of substrate-adsorbed cellulases during long-term hydrolysis of insoluble cellulose. Thermal transitions of adsorbed enzyme were measured regularly in subsets of a progressing hydrolysis, and the size of the transition peak was used as a gauge of the population of native enzyme. Analogous measurements were made for enzymes in pure buffer. Investigations of two cellobiohydrolases, Cel6A and Cel7A, from Trichoderma reesei, which is an anamorph of the fungus Hypocrea jerorina, showed that these enzymes were essentially stable at 25 °C. Thus, over a 53 h experiment, Cel6A lost less than 15% of the native population and Cel7A showed no detectable loss for either the free or substrate-adsorbed state. At higher temperatures we found significant losses in the native populations, and at the highest tested temperature (49 °C) about 80% Cel6A and 35% of Cel7A was lost after 53 h of hydrolysis. The data consistently showed that Cel7A was more long-term stable than Cel6A and that substrate-associated enzyme was less long-term stable than enzyme in pure buffer stored under otherwise equal conditions. There was no correlation between the intrinsic stability, specified by the transition temperature in the DSC, and the long-term stability derived from the peak area. The results are discussed with respect to the role of enzyme denaturation for the ubiquitous slowdown observed in the enzymatic hydrolysis of cellulose.

Borch, Kim; Cruys-Bagger, Nicolaj

2014-01-01

191

In situ stability of substrate-associated cellulases studied by DSC.  

Science.gov (United States)

This work shows that differential scanning calorimetry (DSC) can be used to monitor the stability of substrate-adsorbed cellulases during long-term hydrolysis of insoluble cellulose. Thermal transitions of adsorbed enzyme were measured regularly in subsets of a progressing hydrolysis, and the size of the transition peak was used as a gauge of the population of native enzyme. Analogous measurements were made for enzymes in pure buffer. Investigations of two cellobiohydrolases, Cel6A and Cel7A, from Trichoderma reesei, which is an anamorph of the fungus Hypocrea jerorina, showed that these enzymes were essentially stable at 25 °C. Thus, over a 53 h experiment, Cel6A lost less than 15% of the native population and Cel7A showed no detectable loss for either the free or substrate-adsorbed state. At higher temperatures we found significant losses in the native populations, and at the highest tested temperature (49 °C) about 80% Cel6A and 35% of Cel7A was lost after 53 h of hydrolysis. The data consistently showed that Cel7A was more long-term stable than Cel6A and that substrate-associated enzyme was less long-term stable than enzyme in pure buffer stored under otherwise equal conditions. There was no correlation between the intrinsic stability, specified by the transition temperature in the DSC, and the long-term stability derived from the peak area. The results are discussed with respect to the role of enzyme denaturation for the ubiquitous slowdown observed in the enzymatic hydrolysis of cellulose. PMID:24856176

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

2014-06-24

192

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

International Nuclear Information System (INIS)

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

193

Science implications of delivery techniques and timing for in situ vehicles at Titan  

Science.gov (United States)

NASA and ESA are currently conducting studies of a potential collaborative flagship mission either to Titan, Enceladus, and the Saturn system, or to Europa and the Jupiter system. The Saturn mission study, named the "Titan Saturn System Mission" (TSSM) study until an official name is adopted, is a combination of the "Titan and Enceladus Mission" (TandEM) [1] proposed to and accepted for study by ESA's Cosmic Vision 2015-25 Program, and restructurings of two NASA flagship mission concept studies, "Titan Explorer" [2] and "Enceladus Explorer" [3]. The combined mission is reminiscent of the Cassini/Huygens (CH) collaboration. It would have a NASA Titan-orbiting element and one or more ESA in situ elements that could be carried to Titan by the NASA element. There are multiple architecture options for implementing such a mission, and those architectures influence the options for delivering and supporting the ESA in situ elements. In turn, the options for delivery and support, especially constraints on timing that arise from them, influence the science return expected from the in situ elements.

Spilker, T.; Strange, N.

2008-09-01

194

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

OpenAIRE

The nutritive value of pistachio epicarp (PE) was evaluated by in situ and in vitro techniques. Chemical analysis indicated that PE was high in crude protein (11.30%) and low in neutral detergent fiber (26.20%). Total phenols, total tannins, condensed tannins and hydrolysable tannins contents in PE were 8.29%, 4.48%, 0.49% and 3.79%, respectively. Ruminal dry matter and crude protein degradation after 48 hr incubation were 75.21% and 82.52%, respectively. The gas production volume at 48 hr fo...

Somayeh Bakhshizadeh; Akbar Taghizadeh; Hossein Janmohammadi; Sadegh Alijani

2014-01-01

195

Retrospective cytogenetic biodosimetry using fluorescence in situ hybridisation (FISH) technique in persons exposed to radiation due to the Chernobyl accident  

International Nuclear Information System (INIS)

Cytogenetic biodosimetry of past and chronic radiation exposure to low doses using fluorescence in situ hybridization (FISH) technique in persons exposed due to the Chernobyl accident was carried out. Biological dosimetry based on sable chromosome exchange yield provided the dose estimations of 300 mGy in evacuees and 390 mGy in liquidators, that were in a good agreement with dose assessments obtained in these groups soon after irradiation with conventional analysis (360 and 460 mGy, respectively). The FISH survey of young adult inhabitants of contaminated areas allowed detecting the chronic exposure at average dose of 150 mGy

196

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

Science.gov (United States)

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

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

2014-05-01

197

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

Scientific Electronic Library Online (English)

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

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

2010-04-01

198

Single-chamber, in situ processing of superconducting YBa2Cu3O7 - delta thin films on stainless steel with yttria-stabilized zirconia buffer layer  

Science.gov (United States)

Single-chamber in situ laser processing of high-Tc YBa2Cu3O7-? film on stainless steel (302) substrates with yttria-stabilized zirconia (YSZ) buffer layers, has been carried out using a multitarget deposition system. YSZ and YBa2Cu3O7-? films were deposited sequentially by KrF excimer laser (?=248 nm) at substrate temperature of 650 °C. The films were characterized by x-ray diffraction, four point probe ac electrical resistivity, scanning electron microscopy and Auger electron spectroscopy (AES) techniques. Due to the matching of the thermal expansion coefficient of YSZ with stainless steel and its diffusion barrier characteristics, good quality high-Tc films have been grown on stainless steel substrates with superconducting transition temperature, Tc (onset), of 92 K and Tco (zero resistivity temperature) of 84 K. AES depth profiling indicated little interdiffusion of Fe across the interface of YSZ and stainless steel. A laser evaporation method was used for patterning the YBa2Cu3O7-? films and critical current density, Jc, was measured to be ˜5×104 Acm-2 at 40 K. It was observed that the zero resistivity temperature significantly changed with the variation of buffer layer thickness, buffer layer processing temperature, and ambient oxygen partial pressure during the deposition of YBa2Cu3O7-?.

Kumar, Ashok; Ganapathi, L.; Kanetkar, S. M.; Narayan, J.

1991-02-01

199

Single-chamber, in situ processing of superconducting YBa2Cu3O7-? thin films on stainless steel with yttria-stabilized zirconia buffer layer  

International Nuclear Information System (INIS)

Single-chamber in situ laser processing of high-Tc YBa2Cu3O7-? film on stainless steel (302) substrates with yttria-stabilized zirconia (YSZ) buffer layers, has been carried out using a multitarget deposition system. YSZ and YBa2Cu3O7-? films were deposited sequentially by KrF excimer laser (?=248 nm) at substrate temperature of 650 degree C. The films were characterized by x-ray diffraction, four point probe ac electrical resistivity, scanning electron microscopy and Auger electron spectroscopy (AES) techniques. Due to the matching of the thermal expansion coefficient of YSZ with stainless steel and its diffusion barrier characteristics, good quality high-Tc films have been grown on stainless steel substrates with superconducting transition temperature, Tc (onset), of 92 K and Tco (zero resistivity temperature) of 84 K. AES depth profiling indicated little interdiffusion of Fe across the interface of YSZ and stainless steel. A laser evaporation method was used for patterning the YBa2Cu3O7-? films and critical current density, Jc, was measured to be ?5x104 Acm-2 at 40 K. It was observed that the zero resistivity temperature significantly changed with the variation of buffer layer thickness, buffer layer processing temperature, and ambient oxygen partial pressure during the deposition of YBpressure during the deposition of YBa2Cu3O7-?

200

Thermal Stability of Shear-Induced Precursors of Shish-Kebab in a Model Polyethylene Blend by in-situ Rheo-SAXS and -WAXD  

Science.gov (United States)

In-situ rheo-SAXS (small-angle X-ray scattering) and rheo-WAXD (wide-angle X-ray diffraction) techniques were used to investigate thermal stability of shear-induced shish-kebab structures in a model polyethylene (PE) blend. The blend consisted of a low molecular weight non-crystallizing PE matrix (LMWPE, Mw = 50,000 g/mol, MWD = 2.2) and a small amount of high molecular weight crystallizing PE (HMWPE, Mw = 1,500,000 g/mol, MWD = 1.1). After an imposed steady shear condition in a parallel plate shear stage, rate = 125 s-1, duration = 20 s, Temperature = 126.5 ^oC, both SAXS and WAXD results showed that a shish-kebab morphology developed in the PE blend. Subsequently, the shish-kebab crystals were subjected to several thermal cycles, consisting of melting and crystallization of the oriented structures. Although shish formed first, followed by kebabs; surprisingly, the shish-kebab structure was seen to melt as an integrated entity. This suggests that the shish-kebabs contained integrated stretched and coiled chains (or chain segments), even for near monodispersed chains. The HMWPE oriented structures were found to withstand a high temperature of 152 ^0C (holding time = 3 min) and acted as nuclei for crystallization of unstretched LMWPE chains at lower temperatures.

Zuo, Feng

2005-03-01

201

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

International Nuclear Information System (INIS)

In aerobic aquifers typical of many Department of Energy (DOE) legacy waste sites, uranium is present in the oxidized U(VI) form which is more soluble and thus more mobile. Field experiments at the Old Rifle UMTRA site have demonstrated that biostimulation by electron donor addition (acetate) promotes biological U(VI) reduction (2). However, U(VI) reduction is reversible and oxidative dissolution of precipitated U(IV) after the cessation of electron donor addition remains a critical issue for the application of biostimulation as a treatment technology. Despite the potential for oxidative dissolution, field experiments at the Old Rifle site have shown that rapid reoxidation of bio-reduced uranium does not occur and U(VI) concentrations can remain at approximately 20% of background levels for more than one year. The extent of post-amendment U(VI) removal and the maintenance of bioreduced uranium may result from many factors including U(VI) sorption to iron-containing mineral phases, generation of H2S or FeS0.9, or the preferential sorption of U(VI) by microbial cells or biopolymers, but the processes controlling the reduction and in situ reoxidation rates are not known. To investigate the role of microbial community composition in the maintenance of bioreduced uranium, in-well sediment incubators (ISIs) were developed allowing field deployment of amended and native sediments during on-going experiments at the site. Field deployment of the ISIs allows expedient interrogation of microbial community response to field environmental perturbations and varying geochemical conditions.

202

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

Energy Technology Data Exchange (ETDEWEB)

In aerobic aquifers typical of many Department of Energy (DOE) legacy waste sites, uranium is present in the oxidized U(VI) form which is more soluble and thus more mobile. Field experiments at the Old Rifle UMTRA site have demonstrated that biostimulation by electron donor addition (acetate) promotes biological U(VI) reduction (2). However, U(VI) reduction is reversible and oxidative dissolution of precipitated U(IV) after the cessation of electron donor addition remains a critical issue for the application of biostimulation as a treatment technology. Despite the potential for oxidative dissolution, field experiments at the Old Rifle site have shown that rapid reoxidation of bio-reduced uranium does not occur and U(VI) concentrations can remain at approximately 20% of background levels for more than one year. The extent of post-amendment U(VI) removal and the maintenance of bioreduced uranium may result from many factors including U(VI) sorption to iron-containing mineral phases, generation of H2S or FeS0.9, or the preferential sorption of U(VI) by microbial cells or biopolymers, but the processes controlling the reduction and in situ reoxidation rates are not known. To investigate the role of microbial community composition in the maintenance of bioreduced uranium, in-well sediment incubators (ISIs) were developed allowing field deployment of amended and native sediments during on-going experiments at the site. Field deployment of the ISIs allows expedient interrogation of microbial community response to field environmental perturbations and varying geochemical conditions.

Baldwin, Brett, R.; Peacock, Aaron, D.; Resch, Charles, T.; Arntzen, Evan; Smithgall, Amanda, N.; Pfiffner, Susan; Gan, M.; McKinley, James, P.; Long, Philip, E.; White, David, C.

2008-03-28

203

A study of the rat neuropeptide B/neuropeptide W system using in situ techniques.  

Science.gov (United States)

In the rat, the neuropeptide B/neuropeptide W (NPB/NPW) system is composed of two ligands, neuropeptide B (NPB) and neuropeptide W (NPW), and one receptor, GPR7. Although preliminary analyses show roles in feeding, hormone secretion, and analgesia, the lack of a detailed anatomical map impairs our understanding of the NPB/NPW system. We demonstrate in this report the expression patterns of GPR7, NPB, and NPW precursor messenger ribonucleic acid (mRNA) in the rat brain by using in situ hybridization and in situ binding experiments. The amygdala expresses the highest levels of GPR7 mRNA and binding signals. Other nuclei with high levels of expression and binding are the suprachiasmatic and the ventral tuberomamillary nuclei. Moderate levels are seen in the dorsal endopiriform, dorsal tenia tecta, bed nucleus, and the red nucleus. Low levels are in the olfactory bulb, parastrial nucleus, hypothalamus, laterodorsal tegmentum, superior colliculus, locus coeruleus, and the nucleus of the solitary tract. Although the NPB precursor is mostly expressed at low levels in the brain, moderate expression is seen in anterior olfactory nucleus, piriform cortex, median preoptic nucleus, basolateral amygdala, hippocampus, medial tuberal nucleus, substantia nigra, dorsal raphe nucleus, Edinger-Westphal nucleus, and the locus coeruleus. To our surprise, the expression of NPW precursor was not detected. Our study greatly expands the preliminary in situ data previously reported. With this map of the NPB/NPW system in the rat brain, a better understanding of the functional implications of the system in various behavioral paradigms is now possible. PMID:16736466

Jackson, Valerie R; Lin, Steven H; Wang, Zhiwei; Nothacker, Hans-Peter; Civelli, Olivier

2006-07-20

204

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

Directory of Open Access Journals (Sweden)

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

Humayun Kabir

2010-07-01

205

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

International Nuclear Information System (INIS)

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

206

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

CERN Document Server

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

Savulescu, Savu

2014-01-01

207

A bipolar LED drive technique for high performance, stability and power in the nanosecond time scale  

OpenAIRE

Pulsed light sources are often used to monitor the stability of light detectors such as photomultiplier tubes. Light emitting diodes (LEDs) are suitable for this due to their high specific light yield. While pulsed operation in the region of [mu]s is generally accessible with most LEDs and drivers, the ns time scale often represents a technical challenge. This paper describes a technique of bipolar LED drive that can produce light pulses of a few ns at high stability, reliability and power. T...

Ronchi, Emanuele; Andersson Sunde?n, Erik; Conroy, Sean; Ericsson, Go?ran; Gatu Johnson, Maria; Kallne, J.; Hellesen, Carl; Hjalmarsson, Anders; Sjo?strand, Henrik; Weiszflog, Matthias; Puccio, Walter; A?hlen, Lennart

2009-01-01

208

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

CERN Document Server

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

Stochino, Alberto; Adhikari, Rana X

2012-01-01

209

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

International Nuclear Information System (INIS)

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

210

In-situ high-temperature magnetic resonance imaging of coals using prepared magnetization SPRITE techniques  

Energy Technology Data Exchange (ETDEWEB)

The paper presents a first demonstration of 3D-SPRITE which has been shown to be successful for studying short relaxation time systems and which is free from distortions due to susceptibility variations for coals. The results obtained were discussed in relation to the three-dimensional distribution of mobile components for two kinds of coal. At the same time, inversion recovery preparation experiments, for example, T{sub 1} mapping and T{sub 2}{asterisk} mapping based on SPRITE methods are presented in order to clarify the chemical heterogeneity of coals. Also, we have carried out the first systematic in-situ variable-temperature NMR microimaging study of coals between 25 and 600{sup o}C with our newly developed high-temperature microimaging probe and systems in order to clarify the behaviour of mobile components at high temperatures in heterogeneous coal specimens. Both the mechanisms of softening and melting process for coals and the coal mapping for the softening and melting properties using in-situ imaging experiments which are based on the local information are proposed. 63 refs., 12 figs., 2 tabs.

Saito, K.; Hasegawa, K.; Komaki, I.; Katoh, K. [Nippon Steel Corp. Futtsu City (Japan). Advanced Technology Research Lab.

2002-06-01

211

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

CERN Document Server

In order to investigate the high temperature exposure effect on Nb-Ti/Cu superconducting strands, as might be encountered in joining by soldering and in cabling annealing, X-ray diffraction and resistometry measurements were performed in situ during heat treatment, and complemented by conventional metallography, mechanical tests and superconducting properties measurements. Changes of the Nb-Ti nanostructure at temperatures above 300 degrees C are manifested in the degradation of critical current in an applied external magnetic field, although degradation at self field was insignificant up to 400 degrees C for several minutes. Above 500 degrees C, the formation of various Cu-Ti intermetallic compounds, due to Ti diffusion from Nb-Ti into Cu, is detected by in situ XRD albeit not resolvable by SEM-EDS. There is a ductile to brittle transition near 600 degrees C, and liquid formation is observed below 900 degrees C. The formation of Cu-Ti causes a delayed reduction of the residual resistivity ratio (RRR) and adv...

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

2010-01-01

212

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

Directory of Open Access Journals (Sweden)

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

Sang Jeen Hong

2013-04-01

213

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

OpenAIRE

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

Fang, Lin; Zhou, Chuande; Yang, Mingyong

2013-01-01

214

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

CERN Document Server

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

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

2006-01-01

215

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

International Nuclear Information System (INIS)

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

216

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

217

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

Directory of Open Access Journals (Sweden)

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

S. Panda

2007-06-01

218

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-07-07

219

A new in situ synchrotron X-ray diffraction technique to study the chemical delithiation of LiFePO4.  

Science.gov (United States)

We report a new synchrotron based in situ X-ray diffraction (XRD) technique to study the chemical delithiation of LiFePO(4). This technique provides a new powerful tool to study chemical reactions with excellent time-resolving power for dynamic studies. PMID:21607238

Wang, Xiao-Jian; Chen, Hai-Yan; Yu, Xiqian; Wu, Lijun; Nam, Kyung-Wan; Bai, Jianming; Li, Hong; Huang, Xuejie; Yang, Xiao-Qing

2011-07-01

220

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-12-31

221

In Situ Monitoring of Particle Consolidation During Low Pressure Cold Spray by Ultrasonic Techniques  

Science.gov (United States)

This study attempts to test the viability of the examination of the cold spray process using acoustic methods, specifically in situ testing during the actual spray process itself. Multiple composites studied by flat and multi-channel transducers as well as the results of actual online measurements are presented. It is shown that the final thickness as well as the dynamics of buildup can be evaluated (including plotting rates of buildup). Cross sections of the coating thickness are also easy to obtain and show true profiles of the coating. The data can also be used to generate real estimates for nozzle speed and spray diameter. Finally, comparisons of real thickness and acoustically estimated thickness show a close linear relationship. The data clearly show that online acoustic measurement is a viable method for estimating thickness buildup.

Maev, R. Gr.; Titov, S.; Leshchynsky, V.; Dzhurinskiy, D.; Lubrick, M.

2011-06-01

222

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

Directory of Open Access Journals (Sweden)

Full Text Available We report the fabrication of single electron transistors (SETs by feedback-controlled electromigration of palladium and palladium-nickel alloy nanowires. We have optimized a gradual electromigration process for obtaining devices consisting of three terminals (source, drain and gate electrodes, which are capacitively coupled to a metallic cluster of nanometric dimensions. This metal nanocluster forms into the inter-electrode channel during the electromigration process and constitutes the active element of each device, acting as a quantum dot that rules the electron flow between source and drain electrodes. The charge transport of the as-fabricated devices shows Coulomb blockade characteristics and the source to drain conductance can be modulated by electrostatic gating. We have thus achieved the fabrication and in situ measurement of palladium-based SETs inside a liquid helium cryostat chamber.

L. Arzubiaga

2014-11-01

223

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

Science.gov (United States)

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

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

2012-06-01

224

Ultrasonic techniques for the in situ characterisation of 'legacy' Waste sludges and dispersions - 59111  

International Nuclear Information System (INIS)

Research being undertaken at the University of Leeds, as part of the DIAMOND university consortium, is exploring the effectiveness of various ultrasonic technologies as in situ probes to characterize and monitor nuclear waste slurries, such as the 'Legacy' Magnesium hydroxide sludges found in Sellafield, U.K. Through use of a commercial Acoustic Backscatter Sensor (ABS) with 1 - 5 MHz transducers, various properties of free-settling oxide simulant sludges were determined. Work was focused upon characterizing essentially 'static' sludges (to give prospective use as tools for the wastes in current deposits); although, the sensors also have potential as dispersion monitors during any future processing and storage of the Legacy wastes, as well as many other storage, clarifier or thickener systems across a wide range of industrial processing operations. ABS data of mixed glass powder dispersions was analysed and compared to scattering theory, to understand the correlations between acoustic attenuation and particulate concentration. The ABS was also calibrated to measure changes in average particulate concentration within a settling suspension over time, and showed the depth-wise segregation of the dispersion through the settling column at different particular time intervals. It was found that observed hindered settling also led to an increase in particulate concentration over the sludge zone and significant segregation occurred at moderate time intervals, due to the broad moderate time intervals, due to the broad size distribution of the aggregates measured. It is hoped in future that these sensors may be able to be fitted to robotic handlers that have been installed onsite (and previously used for sampling), allowing fully automatic in situ sludge analysis. (authors)

225

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

International Nuclear Information System (INIS)

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

226

Determination of pelvic ring stability: a new technique using a composite hemi-pelvis.  

Science.gov (United States)

Traumatic disruption of the pelvic ring caused by high-energy impact is associated with significant mortality and morbidity. A variety of fixation techniques have been developed for treating these injuries with the main aims of restoring the stability of the pelvic ring and promoting recovery of normal function. The stability of fixation of these techniques is often analysed by cadaveric studies, which can introduce high variability into the results and have small sample numbers. This study presents a new method that uses a composite hemi-pelvis to enable stabilization of the pelvic ring to be accurately determined. The pelvis was loaded cyclically to simulate walking conditions and to assess the stability of the fixation, which was measured using a displacement transducer that monitors the motion of the pelvis in six degrees of freedom. The motions measured showed comparable results with previously published cadaveric studies. This reproducible method of testing with a hemi-pelvis composite model and rig allows valid analysis of pubic symphysis implants, obviating the difficulties of performing a cadaveric study. PMID:18756680

Clements, J P; Moriaty, N; Chesser, T J S; Ward, A J; Cunningham, J L

2008-07-01

227

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

OpenAIRE

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

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

2010-01-01

228

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

International Nuclear Information System (INIS)

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

229

Accuracy Enhanced Stability and Structure Preserving Model Reduction Technique for Dynamical Systems with Second Order Structure  

DEFF Research Database (Denmark)

A method for model reduction of dynamical systems with the second order structure is proposed in this paper. The proposed technique preserves the second order structure of the system, and also preserves the stability of the original systems. The method uses the controllability and observability gramians within the time interval to build the appropriate Petrov-Galerkin projection for dynamical systems within the time interval of interest. The bound on approximation error is also derived. The numerical results are compared with the counterparts from other techniques. The results confirm that the method is more accurate than the previous counterparts.

Tahavori, Maryamsadat; Shaker, Hamid Reza

230

A Technique for Measuring Rotocraft Dynamic Stability in the 40 by 80 Foot Wind Tunnel  

Science.gov (United States)

An on-line technique is described for the measurement of tilt rotor aircraft dynamic stability in the Ames 40- by 80-Foot Wind Tunnel. The technique is based on advanced system identification methodology and uses the instrumental variables approach. It is particulary applicable to real time estimation problems with limited amounts of noise-contaminated data. Several simulations are used to evaluate the algorithm. Estimated natural frequencies and damping ratios are compared with simulation values. The algorithm is also applied to wind tunnel data in an off-line mode. The results are used to develop preliminary guidelines for effective use of the algorithm.

Gupta, N. K.; Bohn, J. G.

1977-01-01

231

Thermal stability and long term hydrogen/deuterium release from soft to hard amorphous carbon layers analyzed using in-situ Raman spectroscopy. Comparison with Tore Supra deposits  

OpenAIRE

The thermal stability of 200 nm thick plasma enhanced chemical vapor deposited a-C:H and a-C:D layers ranging from soft to hard layers has been studied and compared to that of deposits collected on the Tore Supra tokamak plasma facing components by means of in-situ Raman spectroscopy. Linear ramp heating and long term isotherms (from several minutes to 21 days) have been performed and correlations between spectrometric parameters have been found. The information obtained on ...

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

2015-01-01

232

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 SciELO Peru | Language: Spanish Abstract in spanish 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..

233

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

Directory of Open Access Journals (Sweden)

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

C. Zellweger

2012-10-01

234

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

Directory of Open Access Journals (Sweden)

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

C. Zellweger

2012-07-01

235

A technique for in-situ tritium recovery experiment of breeder material  

International Nuclear Information System (INIS)

In-situ tritium recovery experiments on several lithium ceramics (Li2O, LiAlO2, Li4SiO4, Li2ZrO3) have been conducted in the JRR-2 reactor since 1983, to evaluate tritium recovery characteristics and tritium inventory which are key issues for design of fusion reactor blanket. The experimental apparatus consist of irradiation capsule, tritium measurement system and tritium cleanup system. A capsule was designed to separately accommodate a couple of candidate lithium ceramics. Premixed purge gases of helium and helium plus deuterium or hydrogen flowed down into the capsule contained lithium ceramics and then followed to the measurement system installed ionization chambers. An ceramic electrolyte cell was first used to directly reduce HTO into HT in an actual tritium recovery experiment. Tritium in the purge gas streams was oxidized and completely removed prior to being exhausted through a stack. In the series of experiments, tritium recovery characteristics of candidate breeder materials have been clarified. (author)

236

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1997-06-01

237

Application of fluorescence in situ hybridization technique in the diagnosis of acute promyelocytic leukemia with abnormal immunophenotype  

International Nuclear Information System (INIS)

To evaluate the utilization of fluorescence in situ hybridization (FISH) technique in the diagnosis of acute promyelocytic leukemia(APL) with abnormal immunophenotype, flow cytometry was used to detect the immunophenotype of mononuclear cells in APL patients and PML/RAR? fusion gene was detected by FISH. The mononuclear cells of several APL patients showed abnormal immunophenotype: CD13+ , CD33+ , CD34-, HLA-DR+ and PML/RAR? fusion gene was also detected, which was different from the regular result of APL: HLA- DR-, PML/RAR?+. Therefore, the detection of immunophenotype in APL patients should not be regarded as the sole accurate target for diagnosing leukemia. FISH ,associated with traditional FAB classification, is a simple, rapid, accurate and direct method. It can be used to help confirm the diagnosis, to guide the formulation of a reasonable chemotherapy scheme and to supervise the efficacy of the treatment in patients with leukemia. (authors)

238

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

Science.gov (United States)

The nutritive value of pistachio epicarp (PE) was evaluated by in situ and in vitro techniques. Chemical analysis indicated that PE was high in crude protein (11.30%) and low in neutral detergent fiber (26.20%). Total phenols, total tannins, condensed tannins and hydrolysable tannins contents in PE were 8.29%, 4.48%, 0.49% and 3.79%, respectively. Ruminal dry matter and crude protein degradation after 48 hr incubation were 75.21% and 82.52%, respectively. The gas production volume at 48 hr for PE was 122.47 mL g(-1)DM. As a whole, adding polyethylene glycol (PEG) to PE increased (p < 0.05) gas production volumes, organic matter digestibility and the metabolizable energy that illustrated inhibitory effect of phenolics on rumen microbial fermentation and the positive influence of PEG on digestion PE. The results showed that PE possessed potentials to being used as feed supplements. PMID:25568691

Bakhshizadeh, Somayeh; Taghizadeh, Akbar; Janmohammadi, Hossein; Alijani, Sadegh

2014-01-01

239

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

Directory of Open Access Journals (Sweden)

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

Somayeh Bakhshizadeh

2014-04-01

240

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

Science.gov (United States)

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

Bakhshizadeh, Somayeh; Taghizadeh, Akbar; Janmohammadi, Hossein; Alijani, Sadegh

2014-01-01

241

Efficacy of dynamic muscular stabilization techniques (DMST) over conventional techniques in rehabilitation of chronic low back pain.  

Science.gov (United States)

Low back pain (LBP) is a common health problems. Although it is multifactorial, its treatment varies considerably, including medication, physical therapy modalities, and exercise therapy, and each have several interventions. Despite their effectiveness, their head-to-head comparisons are limited. This study was aimed at 1 such comparison. A total of 30 hockey players, 18 to 28 years of age, with subacute or chronic LBP were randomly assigned equally in 2 groups. One group was treated with conventional treatment--a combination of 2 electrotherapies (ultrasound and short-wave diathermy) and 1 exercise therapy (lumbar strengthening exercises)--and the other group was treated with dynamic muscular stabilization techniques (DMST), an active approach of stabilizing training. The results showed that both the treatments are effective in the management of LBP, but DMST was found to be more effective than conventional treatment. The walking, stand ups, climbing, and pain improved 4.7, 2.0, 1.4, and 2.1 times, respectively, more with DMST than with conventional treatment. With time (days), walking, stand ups, climbing, and pain improved (correlation) significantly (p DMST (r = 0.83 to 0.92) than in conventional treatment (r = 0.40 to 0.75), and their rate of improvement (regression beta coefficients) were also significantly (p DMST (beta = -0.16 to 0.73) than in conventional treatment (beta = -0.07 to 0.15). Subjects matching were perfect (p DMST is more suitable than conventional treatment. PMID:19858754

Kumar, Suraj; Sharma, Vijai P; Negi, Mahendra P S

2009-12-01

242

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1997-10-01

243

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

International Nuclear Information System (INIS)

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

244

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

Science.gov (United States)

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

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

2012-12-01

245

A bipolar LED drive technique for high performance, stability and power in the nanosecond time scale  

International Nuclear Information System (INIS)

Pulsed light sources are often used to monitor the stability of light detectors such as photomultiplier tubes. Light emitting diodes (LEDs) are suitable for this due to their high specific light yield. While pulsed operation in the region of ?s is generally accessible with most LEDs and drivers, the ns time scale often represents a technical challenge. This paper describes a technique of bipolar LED drive that can produce light pulses of a few ns at high stability, reliability and power. The driver also offers control over the properties of the light pulse produced such as shape, intensity and repetition rate. This approach has been studied in 2003 and implemented in 2004 for two fusion neutron spectrometers at the Joint European Torus (JET) namely the Magnetic Proton Recoil upgrade (MPRu) and the Time Of Flight Optimized for Rate (TOFOR). A driver has been manufactured and connected to the scintillation detectors of each spectrometer through an optical fiber distribution network. Both MPRu and TOFOR have been successfully relying on this system for calibration and performance monitoring for several years, confirming the long-term stability and reliability of this technique.

246

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

International Nuclear Information System (INIS)

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

247

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2008-01-01

248

Diamond growth chemistry: Its observation using real time in situ molecular beam scattering techniques  

OpenAIRE

The chemical reactive properties of deuterated methyl radicals on CVD diamond surfaces have been studied with thermal desorption, reactive molecular beam scattering and stochastic simulation techniques, both in the absence and presence of an H-atom flux. The thermal decomposition of adsorbed methyl is shown to be strongly influenced by the concentration of free surface sites. The probability of abstraction of D from adsorbed CD3 by atomic H is 0.05 whilst the probability for removal in the fo...

Loh, Kp; Foord, Js; Jackman, Rb

1997-01-01

249

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

International Nuclear Information System (INIS)

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

250

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

Scientific Electronic Library Online (English)

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

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

2007-11-01

251

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-09-15

252

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

Science.gov (United States)

Since 2004, atmospheric carbon dioxide (CO2) is being measured at the High Altitude Research Station Jungfraujoch by the division of Climate and Environmental Physics at the University of Bern (KUP) using a nondispersive infrared gas analyzer (NDIR) in combination with a paramagnetic O2 analyzer. In January 2010, CO2 measurements based on cavity ring-down spectroscopy (CRDS) as part of the Swiss National Air Pollution Monitoring Network were added by the Swiss Federal Laboratories for Materials Science and Technology (Empa). To ensure a smooth transition - a prerequisite when merging two data sets, e.g., for trend determinations - the two measurement systems run in parallel for several years. Such a long-term intercomparison also allows the identification of potential offsets between the two data sets and the collection of information about the compatibility of the two systems on different time scales. A good agreement of the seasonality, short-term variations and, to a lesser extent mainly due to the short common period, trend calculations is observed. However, the comparison reveals some issues related to the stability of the calibration gases of the KUP system and their assigned CO2 mole fraction. It is possible to adapt an improved calibration strategy based on standard gas determinations, which leads to better agreement between the two data sets. By excluding periods with technical problems and bad calibration gas cylinders, the average hourly difference (CRDS - NDIR) of the two systems is -0.03 ppm ± 0.25 ppm. Although the difference of the two data sets is in line with the compatibility goal of ±0.1 ppm of the World Meteorological Organization (WMO), the standard deviation is still too high. A significant part of this uncertainty originates from the necessity to switch the KUP system frequently (every 12 min) for 6 min from ambient air to a working gas in order to correct short-term variations of the O2 measurement system. Allowing additional time for signal stabilization after switching the sample, an effective data coverage of only one-sixth for the KUP system is achieved while the Empa system has a nearly complete data coverage. Additionally, different internal volumes and flow rates may affect observed differences.

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

2015-01-01

253

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

Directory of Open Access Journals (Sweden)

Full Text Available Since 2004, atmospheric carbon dioxide (CO2 is measured at the High Altitude Research Station Jungfraujoch by the division of Climate and Environmental Physics at the University of Bern (KUP using a nondispersive infrared gas analyzer (NDIR in combination with a paramagnetic O2 analyzer. In January 2010, CO2 measurements based on cavity ring down spectroscopy (CRDS as part of the Swiss National Air Pollution Monitoring Network have been added by the Swiss Federal Laboratories for Materials Science and Technology (Empa. To ensure a smooth transition – a prerequisite when merging two datasets e.g. for trend determinations – the two measurement systems run in parallel for several years. Such a long-term intercomparison also allows identifying potential offsets between the two datasets and getting information about the compatibility of the two systems on different time scales. A good agreement of the seasonality as well as for the short-term variations was observed and to a lesser extent for trend calculations mainly due to the short common period. However, the comparison revealed some issues related to the stability of the calibration gases of the KUP system and their assigned CO2 mole fraction. It was possible to adapt an improved calibration strategy based on standard gas determinations, which lead to better agreement between the two data sets. By excluding periods with technical problems and bad calibration gas cylinders, the average hourly difference (CRDS ? NDIR of the two systems is ?0.03 ppm ± 0.25 ppm. Although the difference of the two datasets is in line with the compatibility goal of ±0.1 ppm of the World Meteorological Organization (WMO, the standard deviation is still too high. A significant part of this uncertainty originates from the necessity to switch the KUP system frequently (every 12 min for 6 min from ambient air to a working gas in order to correct short-term variations of the O2 measurement system. Allowing additionally for signal stabilization after switching the sample, an effective data coverage of only 1/6 for the KUP system is achieved while the Empa system has a nearly complete data coverage. Additionally, different internal volumes and flow rates between the two systems may affect observed differences.

M. F. Schibig

2014-07-01

254

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

Directory of Open Access Journals (Sweden)

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

K. Heeschen

2011-05-01

255

Application of hot patch technique for stabilized post-CHF test in a rod bundle  

International Nuclear Information System (INIS)

Convective boiling beyond critical-heat-flux (CHF) with nonequilibrium between the phases is encountered in a number of applications such as cryogenic systems, steam generators, and in the hypothetical nuclear reactor loss-of-coolant accidents. In a vertical geometry the CHF location may progress up or down depending on the operating conditions. As a result, the phenomena is time dependent and hard to measure accurately. Several experimental studies of such phenomena in a single tube were conducted using a hot-patch technique to arrest the quench front, and generate stabilized post-CHF conditions in the test section. This paper describes the first successful application of the hot-patch technique in rod bundles. Design requirements for the 3X3 rod bundle test section with a heated shroud, and hot patch are described. Preliminary experiments are also presented and show that the quench front can be stabilized with the help of the present hot-patch design for rod bundles. The paper also describes the techniques used for measuring nonequilibrium vapor temperatures, and pressure drop in a high temperature two-phase flow

256

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

Science.gov (United States)

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

Delahaies, Sylvain; Roulstone, Ian; Nichols, Nancy

2014-05-01

257

A chromism-based assay (CHROBA) technique for in situ detection of protein kinase activity.  

Science.gov (United States)

A unique chromism-based assay technique (CHROBA) using photochromic spiropyran-containing peptides has been firstly established for detection of protein kinase A-catalyzed phosphorylation. The alternative method has advantages that avoid isolation and/or immobilization of kinase substrates to remove excess reagents including nonreactive isotope-labeled ATP or fluorescently-labeled anti-phosphoamino acid antibodies from the reaction mixture. Such a novel protocol based on thermocoloration of the spiropyran moiety in the peptide can offer not only an efficient screening method of potent kinase substrates but also a versatile analytical tool for monitoring other post-translational modification activities. PMID:15745830

Tomizaki, Kin-ya; Jie, Xu; Mihara, Hisakazu

2005-03-15

258

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

Energy Technology Data Exchange (ETDEWEB)

It is generally considered that an unsaturated zone is generated in the vicinity of a drift after excavation. In such a zone, invasion of air containing oxygen possibly changes geochemical environment (redox condition) of the rock mass. However, no measurement technique for quantitative understanding of this unsaturated zone is currently available. This study has been started to develop the measuring method in the several years. This year, fundamental information has been obtained through analysis, laboratory experiments using homogeneous rock samples and field measurement described below. (1) experiments on the mechanism of undersaturation in rock. (2) experiments on the measuring method of the extend of unsaturated zone. (author)

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

1997-03-01

259

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

CERN Document Server

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

Mulligan, Tamitha; Lynch, Benjamin J

2012-01-01

260

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

International Nuclear Information System (INIS)

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

261

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

Science.gov (United States)

We have developed a noncontact method to probe the electrical conductivity and complex permittivity of single and polycrystalline samples in a flow-through reactor in the temperature range of 20-500 °C and in various gas atmospheres. The method is based on the microwave cavity perturbation technique and allows the simultaneous measurement of microwave conductivity, permittivity and of the catalytic performance of heterogeneous catalysts without any need for contacting the sample with electrodes. The sensitivity of the method towards changes in bulk properties was proven by the investigation of characteristic first-order phase transitions of the ionic conductor rubidium nitrate in the temperature range between 20 and 320 °C, and by studying the temperature dependence of the complex permittivity and conductivity of a niobium(V)-doped vanadium-phosphorous-oxide catalyst for the selective oxidation of n-butane to maleic anhydride. Simultaneously, the catalytic performance was probed by on line GC analysis of evolving product gases making the technique a real in situ method enabling the noninvasive investigation of electronic structure-function relationships. PMID:22146931

Eichelbaum, Maik; Stösser, Reinhard; Karpov, Andrey; Dobner, Cornelia-Katharina; Rosowski, Frank; Trunschke, Annette; Schlögl, Robert

2012-01-21

262

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

Science.gov (United States)

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

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

2013-12-01

263

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

International Nuclear Information System (INIS)

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

264

Voltage stability constrained ATC computations in deregulated power system using novel technique  

Directory of Open Access Journals (Sweden)

Full Text Available The voltage stability constrained Available Transfer Capability (ATC computations are obtained on IEEE 9-bus by running load flow until the voltage collapse point is achieved by enhancing the load in steps with constant power factor. These results are used to train the Neural Network by using Radial Basis Function Neural Network (RBFN technique. The comparative results of convergence method, L-index method and RBFN network are presented in this study. The results are certainly useful in an online environment of deregulated power system in view of computational simplicity, time and computer memory.

P. Gopi Krishna

2008-12-01

265

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

Science.gov (United States)

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

Tennent, Duncan; Concina, Chiara; Pearse, Eyiyemi

2014-02-01

266

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

Directory of Open Access Journals (Sweden)

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

W. Reid

2012-11-01

267

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

International Nuclear Information System (INIS)

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

268

Development of vacuum transfer techniques for tokamak in-situ surface analysis  

International Nuclear Information System (INIS)

Plasma-wall interactions in tokamaks can in general be divided into atomic scale and grain size effects. The former class of effects include desorption, sputtering, recoil doping, and other related subjects, while the latter includes larger scale phenomena such as blistering, flaking, cracking and evaporation. These latter effects can be analysed using conventional metallurgical techniques. However, atomic scale processes require that the samples be maintained and analysed in a vacuum environment since monolayer changes can occur in minutes at 10-6 Pa (approximately=10-8 Torr). For this reason it is essential that surface analysis either be done in the tokamak during or briefly after a discharge or the surface of interest should be quickly transferred under vacuum to an ultra high vacuum (UHV) instrument for immediate analysis. However, under certain conditions it is desirable to transfer exposed samples or specially prepared substrates under vacuum for analysis in other UHV instruments not on-line. This requires the use of an ultra high vacuum transfer device (VTD). (Auth.)

269

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

Science.gov (United States)

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

Ihara, I.; Tomomatsu, T.

2011-03-01

270

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

International Nuclear Information System (INIS)

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

271

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

Energy Technology Data Exchange (ETDEWEB)

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

Toda, H., E-mail: toda@me.tut.ac.jp [Department of Mechanical Engineering, Toyohashi University of Technology, Toyohashi, Aichi 441-8580 (Japan); Maire, E. [Universite de Lyon, INSA-Lyon, MATEIS CNRS UMR5510, 7 Avenue Jean Capelle, F-69621 Villeurbanne (France); Yamauchi, S.; Tsuruta, H.; Hiramatsu, T.; Kobayashi, M. [Department of Mechanical Engineering, Toyohashi University of Technology, Toyohashi, Aichi 441-8580 (Japan)

2011-03-15

272

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

International Nuclear Information System (INIS)

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

273

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

Science.gov (United States)

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

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

2011-06-01

274

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

International Nuclear Information System (INIS)

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

275

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

Science.gov (United States)

The main advantage of an optoelectronic oscillator (OEO) is the ability to synthesize directly very high spectral purity frequency in microwave domain. Beside applications in radar, telecommunication and satellite systems, OEO can also be used in sensor applications such as refractive index or distance measurements. However, the long-term stability of the OEO is easily affected by ambient environment variations. The optical fiber loop effective refractive index varies corresponding to its surrounding temperature changes. Consequently, it makes the optical transmission path inside the fiber loop differ from the initial state, leading to oscillation frequency changes. To stabilize the single loop OEO, it is essential to keep its high Q elements in a well-controlled thermal box as much as possible. Unfortunately, in the real implementation condition, this requirement is difficult to be satisfied. In this paper, we present a new technique to estimate the oscillation frequency variation under the room temperature by using a vector network analyzer (VNA). Experimental results show a good correlation between OEO oscillation frequency drift and the phase measured by the VNA. This technique can be implemented to apply corrections when using the OEO as a distance variation or a refractive index measurement tool. We also tracked the temperature of the fiber loop at the same time with the VNAbased experiment to compare two correlations of temperature and phase with OEO oscillation frequency.

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

2015-01-01

276

Production of cytokines around loosened cemented acetabular components. Analysis with immunohistochemical techniques and in situ hybridization.  

Science.gov (United States)

The chronic inflammatory response to wear particles from orthopaedic joint implants is believed to cause osteolysis and to contribute to prosthetic loosening. Previous in vitro experiments have demonstrated that particulate debris from joint implants causes cells in culture to release products that have been implicated in this pathological bone resorption. The purpose of the current study was to investigate the in vivo features of this complex process in patients who had had a total hip replacement. Membraneous tissue was obtained from the cement-bone interface of ten polyethylene acetabular components that had been revised for aseptic loosening in ten patients. The immunoperoxidase technique, which involves the use of specific antibodies for each cell type, showed that macrophages were the predominant cellular constituents but also that fibroblasts, many of which were not identified on plain histological study, were present and were actively producing collagen. T lymphocytes were present variably, but they generally composed less than 10 percent of the cells. Particulate debris (polyethylene, methylmethacrylate, and metal) was present in all membrane specimens but was intracellular only in macrophages and multinucleated giant cells. 35S-labeled nucleic-acid probes, complementary to human interleukin-1-beta and to platelet-derived growth-factor-2 messenger RNA (mRNA), were hybridized with serial tissue sections. Hybridization demonstrated interleukin-1-beta mRNA predominantly in macrophages, and not in fibroblasts or in T lymphocytes to any major extent. In contrast, immunolocalization demonstrated interleukin-1-beta protein on both macrophages and fibroblasts, suggesting that macrophages release interleukin-1-beta, which then binds to both fibroblasts and macrophages. Platelet-derived growth-factor transcripts were found in both macrophages and fibroblasts. PMID:8314826

Jiranek, W A; Machado, M; Jasty, M; Jevsevar, D; Wolfe, H J; Goldring, S R; Goldberg, M J; Harris, W H

1993-06-01

277

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

International Nuclear Information System (INIS)

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

278

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

International Nuclear Information System (INIS)

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

279

Novel in situ gelling ocular films for the opioid growth factor-receptor antagonist-naltrexone hydrochloride: Fabrication, mechanical properties, mucoadhesion, tolerability and stability studies.  

Science.gov (United States)

Naltrexone hydrochloride (NTX) is an innovative drug used in ophthalmology for treatment of ocular surface diseases such as impaired corneal wound healing and severe dry eye. Poor chemical stability has been a major limitation for development of NTX in solution form. The aim of this study was to develop and characterise NTX in situ ocular films for enhanced chemical stability and improved ocular tolerability. The films were prepared from different amorphous polymers and characterised for physicochemical compatibility, moisture-sorption, surface pH, mechanical properties, sterilisability, surface morphology, mucoadhesion, in vitro release, conjunctival irritation and accelerated stability at 40°C/75% relative humidity for 3 months. Glycerin (GLY)-plasticised films exhibited significantly better mechanical properties, compared with polyethylene glycol (PEG) 400 and triethylcitrate (TEC)-plasticised formulations. Superior mucoadhesion was recorded for F7 and F9 plasticised with GLY and PEG 400, respectively. The stability of NTX was significantly enhanced more than 18-times, compared with the solution form. Combination of carboxymethylcellulose sodium (CMC) and sodium alginate (ALG) in a film formulation demonstrated minimal % moisture sorption, good mechanical properties, in vitro release, excellent chemical stability and minimal conjunctival irritation lending them as promising ocular formulations. PMID:25445974

Abdelkader, Hamdy; Pierscionek, Barbara; Alany, Raid G

2014-12-30

280

I Situ Characterization Techniques for Droplets and Sprays Using Nonlinear Optics.  

Science.gov (United States)

The applicability of nonlinear light scattering to determine droplet and spray properties is examined. Optical properties related to droplet morphology can be used to gain information about droplet size, shape, evaporation rate, and surface tension. The optical properties of droplets are advantageously applied to fluorescence, lasing and stimulated Raman scattering (SRS) to selectively image^1 the various constituents of a pintle nozzle spray. The vapor, liquid ligaments, and droplets of differing sizes exhibit different types of scattering, enabling spatial discrimination. The discrete spectral resonances of Rhodamine 6G dye-doped droplets that are flowing in a closely spaced array to approximate a spray, are monitored^2 to deduce droplet evaporation rates. The deduced evaporation rates are observed to vary according to position within the array nozzle, consistent with the relative amount of vapor which surrounds the individual droplets. This vapor is subsequently imaged using a fluorescence technique. ^2. Very small shape deformations of flowing droplets are measured.^3 Theory indicates that the cavity resonances of a deformed droplet should precess about the symmetry axis. Laser pulses of 100 ps duration are used to generate SRS within a select group of morphology-dependent resonances (MDR's). The precession of the resulting MDR wavepacket is observed and the precession frequency is used to deduce^4 the magnitude of shape deformation. Time resolved measurements of the SRS generation, as a function of pump intensity, reveal a more subtle pumping scheme. The dependence^5 of the nonlinear signal on the number and temporal separation of pump pulses suggests that the interaction of each pump pulse with the droplet cannot be considered as an independent event. The observed time scales suggest that the coupling mechanism involves the retention of long-lived acoustic phonons which are generated by near-forward scattered stimulated Brillouin scattering. ftn^1A. Serpenguzel, J. C. Swindal, R. K. Chang, W. P. Acker, "Two Dimensional Imaging of Sprays with Fluorescence, Lasing, and Stimulated Raman Scattering," Applied Optics, 31, 3543-3551 (1992). ^2J. C. Swindal, G. Chen, A. Serpenguzel, W. P. Acker, and R. K. Chang, "Spray Diagnostics with Lasing and Stimulated Raman Scattering," in Recent Advances in Spray Combustion, AIAA Progress Series, (submitted). ^3J. C. Swindal, D. H. Leach, R. K. Chang, and K. Young, "Precession of Morphology -Dependent Resonances in Nonspherical Droplets," Optics Letters, Vol. 18, 191-193 (1993). ^4J. C. Swindal, D. H. Leach, R. K. Chang, and K. Young, "Precession of Morphology-Dependent Resonances in Nonspherical Droplets," Optics Letters, Vol. 18, 191-193 (1993). ^5 F. H. Wirth, K. A. Juvan, D. H. Leach, J. C. Swindal, R. K. Chang, and P. T. Leung, "Phonon-Retention Effects on Stimulated Brillouin Scattering from Micrometer-Sized Droplets Illuminated with Multiple Short Laser Pulses," Optics Letters, Vol. 17, 1334-1336 (1992).

Swindal, J. Christian

281

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-05-01

282

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

International Nuclear Information System (INIS)

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

283

Wheat improvement for drought resistance and yield stability using mutation techniques  

International Nuclear Information System (INIS)

The main problem of plant breeding is development of varieties with optimal combination of high drought resistance, productivity and yield stability in varying unfavorable conditions. It is especially important for Kazakhstan, the main agricultural areas of which are located in the arid zones characterized by moisture supply deficiency. Mutation techniques have proven to be valuable technique in enhancing crop genetic diversity for selecting new variants with traits of economic importance. Therefore we used M2 population of spring bread wheat var. Kazakhstastanskaya 126 treated by nicotinic acid extracted from tobacco leaves 0,01% and 0,1%, respectively. Based on germplasm of M2 there was developed genotype Grekum 476 having changes in leaf shape such as rolling of flag leaf. This trait protects plant from intensive insolation and overheating, prevent losses of water and provide long-term function of leaves and therefore it was used for wheat improvement of commercial cultivars. The objective of this study is the analysis of genotype x environment interaction (GEI) and evaluation of the donors of drought resistance and stability among the winter wheat genotypes. Experimental material has been grown in 2004-2006 at thee contrasting ecological zones including irrigated and non-irrigated conditions. To analyze GEI the method Tai (1971) was used. Drought susceptibility index was used for drought resistance assessment (Fisher and Maurer, 1978). The obsessment (Fisher and Maurer, 1978). The objects of study were wheat genotypes with inserted leaf rolling trait (Grekum 476, Hostianum 88, Albidum 109, Miras), and varieties developed in Kazakhstan and the Ukraine, that differ in the level of productivity and drought resistance. It was found that rolling leaf trait in the main source Grekum 476 is controlled by two dominant Rl-genes. The genotypes with Rl-genes able to conserve high leaf water potential as the tendency for greater leaf hydration seems to be a consequence of osmotic adjustment connected to drought resistance has a high level of osmotic adjustment. Analysis of GEI allowed differentiating experimental material by the level of stability. The best stability observed in donors of RL-genes - Grekum 476 and Album 109. The biggest level of field drought resistance was observed in varieties Bogarnaya 56, Krasnovodopadskaya 210 and Grekum 476, which were high yielding in stress environments. It is known that ecological reaction of adaptability - the rolling of leaves, is the characteristics for the varieties with Rl-genes. This trait allows using water economically by limitation of transpiration, to regulate plant water balance more efficiently. Obviously, the high level of drought resistance of Grekum 476 has been provided by the presence in its genotype of Rl-genes. Thus, the use of chemical mutagen allowed widening the spectrum of genetic variability of wheat germplasm. In comparison to the origin cultivar Kazakhstanskaya 126, their mutant derivatives demonstrated higher level of drought resistance and yield stability. These germplasms were ranged by the level of yield stability and drought resistance in wheat. The relationship between field drought resistance and ecological parameters of stability was found. (author)

284

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

International Nuclear Information System (INIS)

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

285

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

Science.gov (United States)

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

Sarma, Abhisakh; Sanyal, Milan K.

2014-09-01

286

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

International Nuclear Information System (INIS)

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

287

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

Directory of Open Access Journals (Sweden)

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

Abhisakh Sarma

2014-09-01

288

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

International Nuclear Information System (INIS)

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

289

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

Energy Technology Data Exchange (ETDEWEB)

In-situ x-ray diffraction technique has been used to study the growth process of gold incorporated polypyrrole nanotubes that exhibit colossal dielectric constant due to existence of quasi-one-dimensional charge density wave state. These composite nanotubes were formed within nanopores of a polycarbonate membrane by flowing pyrrole monomer from one side and mixture of ferric chloride and chloroauric acid from other side in a sample cell that allows collection of x-ray data during the reaction. The size of the gold nanoparticle embedded in the walls of the nanotubes was found to be dependent on chloroauric acid concentration for nanowires having diameter more than 100 nm. For lower diameter nanotubes the nanoparticle size become independent of chloroauric acid concentration and depends on the diameter of nanotubes only. The result of this study also shows that for 50 nm gold-polypyrrole composite nanotubes obtained with 5.3 mM chloroauric acid gives colossal dielectric constant of about 10{sup 7}. This value remain almost constant over a frequency range from 1Hz to 10{sup 6} Hz even at 80 K temperature.

Sarma, Abhisakh; Sanyal, Milan K., E-mail: milank.sanyal@saha.ac.in [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India)

2014-09-15

290

Vacuum Ultraviolet (VUV)-Light-Induced Outgassing from Resist Polymers: A Study Using In Situ Quartz Crystal Microbalance (QCM) Technique  

Science.gov (United States)

Vacuum ultraviolet (VUV)-light-induced photodegradation of conventional KrF and ArF resists and fluorine-containing polymers for F2 resist was qualitatively studied by reflection absorption infrared spectroscopy. Outgassing from these resists was quantitatively studied by an in situ quartz crystal microbalance (QCM) technique. t-Butoxycarbonyl (BOC), methoxymethyl (MOM), ethoxyethyl (EOE) and t-butyl (BUO) units as a blocking moiety of phenolic OH decomposed on irradiation at 146 nm. The amounts of outgassing from these blocking units decreased in the order EOE > BOC > BUO > MOM. This order was consistent with the order of photodegradability of the resists checked by FT-IR spectroscopy. BOC units attached to hexafluoroisopropanol units photodecomposed faster than BOC units attached to phenolic OH. The amounts of outgassing from t-butyl ester unit and its analogue in conventional ArF resists and fluorine-containing F2 resist were almost the same as that from BOC units in KrF resist.

Shirai, Masamitsu; Shinozuka, Toyofumi; Tsunooka, Masahiro; Itani, Toshiro

2003-06-01

291

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

Science.gov (United States)

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

Wall, Conrad., III

1999-01-01

292

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

Science.gov (United States)

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

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

2010-05-01

293

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

International Nuclear Information System (INIS)

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

294

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

International Nuclear Information System (INIS)

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

295

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-02-14

296

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

International Nuclear Information System (INIS)

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

297

Multi-platform in-situ and remote sensing techniques to derive Saharan dust properties during AMISOC-TNF 2013  

Science.gov (United States)

In the framework of AMISOC (Atmospheric Minor Species relevant to the Ozone Chemistry) project, a multiinstrumented campaign was performed in the Canary Islands area in summer-time from 01 July to 11 August 2013. Both ground-based remote-sensing and airborne in-situ measurements were performed under dust loading conditions. Saharan dusty (DD) conditions were reported during 57% of the overall campaign period. Particular DD cases corresponded to a 2-day period with a progressively arriving Saharan dust intrusion over Tenerife on 31 July (weak incidence) and 01 August (strong incidence). As reference, the non-dusty (ND) situation on 30 July was also examined. Vertical size distributions (SD) for particles within an extended fine-to-coarse (0.16-2.8 ?m) mode were provided by using aircraft aerosol PCASP sonde measurements. Extinction profiles and Lidar ratio (LR) values were derived from Micro Pulse Lidar measurements. Despite no MAXDOAS aerosol profiling retrievals were available, the potential of this technique has also been introduced. A good agreement is found between the optical and microphysical properties, showing dust particles confined in a wide layer of around 4.5 km thickness from 1.5 to 6 km height. Dust incidence mostly affected the Free Troposphere (FT). LR ranged between 50 and 55 sr, showing typical values for Saharan dust particles. In general, the dust impact on mass concentration was enhanced due to the increase of larger particles, affecting both the Boundary layer (BL) and FT, but showing differences depending on the dusty case. MAXDOAS profiles are expected to be included in an extended version of this work.

Córdoba-Jabonero, Carmen; Andrey, Javier; Adame, José Antonio; Sorribas, Mar; Gómez, Laura; Cuevas, Emilio; Gil-Ojeda, Manuel

2014-10-01

298

Probing polymer melt structure at the early stages of crystallization by in-situ rheo -SAXS and -WAXD techniques  

Science.gov (United States)

Flow fields strongly affect polymer crystallization, both in terms of phase transition and solid state morphology. Arguments, based on the average properties (such as entropy reduction and related elevation of melting point) of deformed melts does not fully account for high sensitivity of polymer crystallization kinetics to flow and deformation. Local orientation of macromolecular chains and its effect on the primary nucleation step is likely to be the determining phenomenon. In-situ rheo --SAXS (small angle x-ray scattering) and --WAXD (wide angle x-ray diffraction) techniques were used to probe the shear-induced precursor structures (primary nuclei) at the early stages of crystallization in isotactic polypropylene melt near its melting point. Initial SAXS patterns, immediately after shear (rate = 60 s ^--1, ts = 5 s), showed emergence of equatorial streaks due to oriented structures (precursors for microfibrils or shish) parallel to the flow direction and of meridional maxima due to growth of the oriented layer-like structures (precursors for kebabs) perpendicular to the flow; however, no crystal reflections were observed in corresponding WAXD patterns. SAXS and WAXD patterns at later times (t = 120 min after shear) indicated that the induced oriented structures were stable above the nominal melting point of iPP. DSC thermograms of sheared iPP samples confirmed the presence of two populations of crystalline fractions; one at 164 ^oC (corresponding to the normal melting point) and the other at 179 ^oC (corresponding to melting of oriented crystalline structures). \\underline Acknowledgements: We wish to acknowledge the assistance of Drs. Fengji Yeh, Lizhi Liu, Dufei Fang, and Shaofeng Ran of SUNY, Stony Brook for synchrotron SAXS and WAXD experimental setup. The financial support for this work was provided by NSF DMR-9732653 and by ExxonMobil.

Somani, R. H.; Yang, L.; Hsiao, B. S.; Agarwal, P.; Fruitwala, H.; Tsou, A.

2002-03-01

299

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

OpenAIRE

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

Koteswara Rao, D.

2011-01-01

300

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

DEFF Research Database (Denmark)

In oil-in-water emulsions, lipid oxidation is expected to be initiated at the oil-water interface. The properties of the emulsifier used, and the structure at the interface is therefore expected to be of great importance for lipid oxidation in emulsions. Previous studies have shown that e.g. homogenization pressure can affect how proteins locate themselves at the interface of an emulsion. The hypothesis is therefore that emulsions produced with different emulsification equipments differ in their oxidative stability due to differences in the behaviour of the proteins at the interface. The aim of this study was therefore to compare lipid oxidation in 10% fish oil-in-water emulsions prepared by two different kinds of high pressure homogenizers i.e. a microfluidizer and a two valve high pressure homogenizer. Emulsions were made with equal droplet sizes, and with either 1% sodium caseinate or 1% whey protein isolate. Emulsions were characterised and investigated by microscopy. Lipid oxidation was assessed by PV and the formation of secondary volatile oxidation products. Results showed that the different emulsification techniques had an influence on lipid oxidation and that the effect of the emulsification technique depended on the type of protein used as an emulsifier.

Horn, Anna Frisenfeldt; Nielsen, Nina Skall

301

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

DEFF Research Database (Denmark)

In oil-in-water emulsions, lipid oxidation is expected to be initiated at the oil-water interface. The properties of the emulsifier used, and the structure at the interface is therefore expected to be of great importance for lipid oxidation in emulsions. Previous studies have shown that e.g. homogenization pressure can affect how proteins locate themselves at the interface of an emulsion. The hypothesis is therefore that emulsions produced with different emulsification equipments differ in their oxidative stability due to differences in the behaviour of the proteins at the interface. The aim of this study was to compare lipid oxidation in 10% fish oil-in-water emulsions prepared by two different kinds of high pressure homogenizers i.e. a microfluidizer and a two valve high pressure homogenizer. Emulsions were made with equal droplet sizes, and with either 1% sodium caseinate or 1% whey protein isolate. Emulsions were characterised and investigated by microscopy. Lipid oxidation was assessed by PV and the formation of secondary volatile oxidation products. Results showed that the different emulsification techniques had an influence on lipid oxidation and that the effect of the emulsification technique depended on the type of protein used as an emulsifier.

Horn, Anna Frisenfeldt; Nielsen, Nina Skall

302

In-situ HEED structure analysis of AlN[sub x] films grown by the simultaneous use of a radical beam source and ICB technique  

Energy Technology Data Exchange (ETDEWEB)

A reactive ionized cluster beam technique (R-ICB) which was composed of a conventional ICB source and a radical beam source has been used to deposit stable and metastable polycrystalline AlN[sub x] (0[<=]x[<=]1) films. Using in-situ high energy electron diffraction (HEED) at grazing incidence geometry, crystallographic properties such as structure, preferred orientation and interplanar d-spacing values were determined and the relation to deposition parameters investigated. It could be shown that the simultaneous use of the ICB technique and a radical beam source to separately control the kinetic energy of the Al ions and the dissociation rate of molecular nitrogen, allows AlN films to be deposited with variable composition and crystal structures. In-situ HEED used in the transmission mode is an effective tool to investigate the crystallography of growing compound films such as AlN[sub x]. (orig.)

Richthofen, A. von (Lehrstuhl fuer Theoretische Huettenkunde, Rheinisch-Westfaelische Technische Hochschule Aachen (Germany)); Neuschuetz, D. (Lehrstuhl fuer Theoretische Huettenkunde, Rheinisch-Westfaelische Technische Hochschule Aachen (Germany))

1994-05-01

303

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

Directory of Open Access Journals (Sweden)

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

M. Ataei

2008-01-01

304

Rapid in situ hybridization technique using 16S rRNA segments for detecting and differentiating the closely related gram-positive organisms Bacillus polymyxa and Bacillus macerans.  

OpenAIRE

A rapid, sensitive, inexpensive in situ hybridization technique, using 30-mer 16S rRNA probes, can specifically differentiate two closely related Bacillus spp., B. polymyxa and B. macerans. The 16S rRNA probes were labeled with a rhodamine derivative (Texas Red), and quantitative fluorescence measurements were made on individual bacterial cells. The microscopic fields analyzed were selected by phase-contrast microscopy, and the fluorescence imaging analyses were performed on 16 to 67 individu...

Jurtshuk, R. J.; Blick, M.; Bresser, J.; Fox, G. E.; Jurtshuk, P.

1992-01-01

305

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

Science.gov (United States)

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

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

2013-01-01

306

STABILITY OF PATTERNS OF BEHAVIOR IN THE BUTTERFLY TECHNIQUE OF THE ELITE SWIMMERS  

Directory of Open Access Journals (Sweden)

Full Text Available The purpose of this study was to find patterns in the butterfly swimming technique, with an adaptation of the Behavioral Observation System Tech. This, as an instrument for ad-hoc qualitative analysis, enables the study of the stability of the technical implementation. When used in the training of swimmers, analysis can reduce the variability of behavioral tuning swimming technique. Through the analysis of temporal patterns (T-pattern and a sequence of five cycles running at hand maximum speed, the behavior of four technical Portuguese elite swimmers, with a record of 259 alphanumeric codes and a total of 160 configurations, were studied. The structure of the original instrument, based on a mixed system of categories and formats Field, can record technical features, observed during the execution of hand cycles. The validity was ensured through the index of intra-observer reliability (95% and inter-observer accuracy (96%. To detect patterns in each swimmer, the Theme 5.0 software was used, which allowed to identify the stable structures of technical performance within a critical interval of time (p <0.05 - t-patterns. The patterns were different, adjusting to the characteristics of technical implementation of the swimmers. It was found that the swimmer can create settings with different levels of structure complexity, depending on the implementation of changes within the hand cycle. Variations of codes in each configuration obtained using the SOCTM, allowed determining the differences between swimmers. However, the records showed a clear behavioral similarity when comparing the result with a general pattern of the butterfly technique. The potential quality of this instrument seems to be important due to the patterns obtained from a temporal sequence

Hugo Louro

2010-09-01

307

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

International Nuclear Information System (INIS)

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

308

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

OpenAIRE

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

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

2014-01-01

309

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

Science.gov (United States)

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

Czapla-Myers, J.

2013-12-01

310

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

International Nuclear Information System (INIS)

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

311

A numerical study on combustion-stability rating of impinging-jet injector using air-injection technique  

International Nuclear Information System (INIS)

Combustion stability rating of jet injector is conducted numerically using air-injection technique in a model chamber, where air is supplied to oxidizer and fuel manifolds of the model five-element injector head. A sample F(fuel-O(oxidizer)-O-F impinging-jet injector is adopted. In this technique, we can simulate mixing process of streams flowing through oxidizer and fuel orifices under cold-flow condition without chemical reaction. The model chamber was designed based on the methodologies proposed in the previous work regarding geometrical dimensions and operating conditions. From numerical data, unstable regions can be identified and they are compared with those from air-injection acoustic and hot-fire tests. The present stability boundaries are in a good agreement with experimental results. The proposed numerical method can be applied cost-effectively to stability rating of jet injectors when mixing of fuel and oxidizer jets is the dominant process in instability triggering

312

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

OpenAIRE

We study the growth of the Fe films on GaAs(100) at a low temperature, 140 K, by $in$-$situ$ UHV x-ray reflectivity using synchrotron radiation. We find rough surface with the growth exponent, $\\beta_S$ = 0.51$\\pm$0.04. This indicates that the growth of the Fe film proceeds via the restrictive relaxation due to insufficient thermal diffusion of the adatoms. The XRR curves are nicely fit by a model with a uniform Fe film, implying that the surface segregation and interface al...

Kim, T. C.; Lee, J. -m; Kim, Y.; Noh, D. Y.; Oh, S. -j; Kim, J. -s

2006-01-01

313

In-Situ Uranium Stabilization Through Polyphosphate Injection: Pilot-Scale Treatability Test at the 300 Area, Hanford Site - 8187  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the pilot-scale treatability test that was conducted to evaluate the efficacy of using a polyphosphate injection approach to treat uranium-contaminated groundwater in situ within the 300 Area aquifer at the Hanford Site in Richland, Washington. Primary test objectives were to assess 1) direct treatment of available uranium contributing to the groundwater plume through precipitation of the uranyl phosphate mineral autunite, and 2) emplacement of secondary-treatment capacity via precipitation of the calcium phosphate mineral apatite, which acts as a long-term sorbent for uranium.

Vermeul, Vince R.; Fruchter, Jonathan S.; Fritz, Brad G.; Mackley, Rob D.; Wellman, Dawn M.; Williams, Mark D.

2008-06-02

314

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

Science.gov (United States)

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

Li, Xiabing; Coldham, Iain

2014-04-16

315

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

Directory of Open Access Journals (Sweden)

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

Suriatie Yusuf

2013-01-01

316

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

Science.gov (United States)

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

Gribanov, K.; Jouzel, J.; Bastrikov, V.; Bonne, J.-L.; Breon, F.-M.; Butzin, M.; Cattani, O.; Masson-Delmotte, V.; Rokotyan, N.; Werner, M.; Zakharov, V.

2014-06-01

317

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

Directory of Open Access Journals (Sweden)

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

K. Gribanov

2014-06-01

318

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

Science.gov (United States)

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

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

2014-10-01

319

Thermal stability and long term hydrogen/deuterium release from soft to hard amorphous carbon layers analyzed using in-situ Raman spectroscopy. Comparison with Tore Supra deposits  

CERN Document Server

The thermal stability of 200 nm thick plasma enhanced chemical vapor deposited a-C:H and a-C:D layers ranging from soft to hard layers has been studied and compared to that of deposits collected on the Tore Supra tokamak plasma facing components by means of in-situ Raman spectroscopy. Linear ramp heating and long term isotherms (from several minutes to 21 days) have been performed and correlations between spectrometric parameters have been found. The information obtained on the sp 2 clustering has been investigated by comparing the G band shift and the 514 nm photon absorption evolution due to the thermal treatment of the layer. The effects of isotopic substitution have also been investigated.

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

2015-01-01

320

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

International Nuclear Information System (INIS)

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

321

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-04-15

322

Effect of annealing on the superconducting and normal state properties of the doped multifilamentary Cu-Nb composite wires prepared by in situ technique  

International Nuclear Information System (INIS)

The effect of annealing on the superconducting and normal state properties of the Ga-, In-, Ti- and Zr-doped (1 wt%) Cu-Nb composite wires prepared by in situ technique have been investigated in this paper. The wires annealed at 700 C for 10 h and then quenched at room temperature, show a decrease in the superconducting transition temperature, Tc, and increase in the transition width, ?T. Doping of the Cu-Nb wires causes an increase in the normal state resistivity and hence the upper critical field, HC2. This results in a significant increase of Jc. Annealing of these doped samples decreases HC2 and Jc. In the case of In- and Ga-doped samples Jc shows a marginal improvement at lower field but decreases at higher field. Zr and Ti doping appears to be beneficial for the improved Jc in these in situ materials. (orig.)

323

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

Directory of Open Access Journals (Sweden)

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

Vijay Raghunathan

2012-06-01

324

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

Science.gov (United States)

Nanoscale zero-valent iron (NZVI) stabilized with dispersants is a promising technology for the remediation of contaminated groundwater. In this study, we demonstrated the use of biodegradable surfactant stabilized NZVI slurry for successful treatment of vinyl chloride (VC) and 1,2-dichloroethane (1,2-DCA) in a contaminated site in Taiwan. The biodegradable surfactant stabilized NZVI was coated with palladium and synthesized on-site. From monitoring the iron concentration breakthrough and distribution, it was found that the stabilized NZVI is capable of transporting in the aquifer at the test plot (200 m(2)). VC was effectively degraded by NZVI while the 1,2-DCA degradation was relatively sluggish during the 3-month field test. Nevertheless, as 1,2-DCA is known to resist abiotic reduction by NZVI, the observation of 1,2-DCA degradation and hydrocarbon production suggested a bioremediation took place. ORP and pH results revealed that a reducing condition was achieved at the testing area facilitating the biodegradation of chlorinated organic hydrocarbons. The bioremediation may be attributed to the production of hydrogen gas as electron donor from the corrosion of NZVI in the presence of water or the added biodegradable surfactant serving as the carbon source as well as electron donor to stimulate microbial growth. PMID:22118849

Wei, Yu-Ting; Wu, Shian-chee; Yang, Shi-wei; Che, Choi-Hong; Lien, Hsing-Lung; Huang, De-Huang

2012-04-15

325

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

International Nuclear Information System (INIS)

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

326

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

Science.gov (United States)

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

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

2009-12-01

327

Spectroscopic techniques in the study of radioactive nuclei far from stability: Results for the Z=82 region  

International Nuclear Information System (INIS)

Techniques that have been used at UNISOR for the study of the structure of very neutron-deficient Pt, Au, and Hg isotopes are described. In particular, the aspects of this experimental program which lead to the establishment of a new class of nuclear-structure phenomenon (low-lying, low-energy, electric-monopole transitions) are described. At the core of this program lies the almost unused technique of observing coincidences between ? rays and conversion electrons. Additional techniques developed at UNISOR for radioactive-decay spectroscopy far from stability are also described. Finally, the broader range of options for studying nuclear structure far from stability, with emphasis on the future, are outlined. 31 refs., 18 figs

328

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

OpenAIRE

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

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

2010-01-01

329

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

International Nuclear Information System (INIS)

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

330

Thermal stability and kinetic study of poly(ethyl methacrylate-co-acrylonitrile) nanocomposites prepared by in situ polymerization in presence of an Algerian bentonite  

Energy Technology Data Exchange (ETDEWEB)

Graphical abstract: - Highlights: • poly(ethyl methacrylate-co-acrylonitrile) nanocomposites were successfully prepared. • These nanocomposites were of higher T{sub g} and improved thermal stability. • Their (E{sub ?}) of thermal decomposition were higher than those of the virgin copolymer. • Increase of (E{sub ?}), confirmed change in the degradation mechanism with clay loading. - Abstract: Poly(ethyl methacrylate-co-acrylonitrile) (PEAMN20) nanocomposites were successfully prepared via free radical in situ polymerization using a bentonite from Algeria modified by Hexadecyltrimethylammonium chloride (HDTMA). X-ray diffraction (XRD) and transmission electronic microscopy (TEM) investigations revealed that depending on the OMMT loading, intercalated or partially exfoliated nanocomposites were obtained. These nanocomposites exhibited an overall improved thermal stability and an increase in their glass transition temperature compared to the pure copolymer (PEMAN20) as evidenced by Thermogravimetric (TGA) and Differential Scanning Calorimetry (DSC) analysis. Apparent activation energies (E{sub ?}) of thermal decomposition of the elaborated nanocomposites, determined by Tang method, were higher than those of the virgin copolymer. The significant increase of (E{sub ?}), observed with PEMAN20/OMMT (1 wt%) confirmed the change in the degradation mechanism with OMMT loading and the ratio of intercalated/exfoliated structures.

Kadi, Souad [Université des Sciences et de la Technologie Houari Boumediene, Laboratoire des Matériaux Polymères, Faculté de Chimie, BP 32 El-Alia, Bab-Ezzouar, 16111 Algiers (Algeria); Djadoun, Saïd, E-mail: matpolylab@yahoo.fr [Université des Sciences et de la Technologie Houari Boumediene, Laboratoire des Matériaux Polymères, Faculté de Chimie, BP 32 El-Alia, Bab-Ezzouar, 16111 Algiers (Algeria); Sbirrazzuoli, Nicolas [Univ. Nice Sophia Antipolis, CNRS, LPMC, UMR 7336, 06100 Nice (France)

2013-10-10

331

Thermal stability and kinetic study of poly(ethyl methacrylate-co-acrylonitrile) nanocomposites prepared by in situ polymerization in presence of an Algerian bentonite  

International Nuclear Information System (INIS)

Graphical abstract: - Highlights: • poly(ethyl methacrylate-co-acrylonitrile) nanocomposites were successfully prepared. • These nanocomposites were of higher Tg and improved thermal stability. • Their (E?) of thermal decomposition were higher than those of the virgin copolymer. • Increase of (E?), confirmed change in the degradation mechanism with clay loading. - Abstract: Poly(ethyl methacrylate-co-acrylonitrile) (PEAMN20) nanocomposites were successfully prepared via free radical in situ polymerization using a bentonite from Algeria modified by Hexadecyltrimethylammonium chloride (HDTMA). X-ray diffraction (XRD) and transmission electronic microscopy (TEM) investigations revealed that depending on the OMMT loading, intercalated or partially exfoliated nanocomposites were obtained. These nanocomposites exhibited an overall improved thermal stability and an increase in their glass transition temperature compared to the pure copolymer (PEMAN20) as evidenced by Thermogravimetric (TGA) and Differential Scanning Calorimetry (DSC) analysis. Apparent activation energies (E?) of thermal decomposition of the elaborated nanocomposites, determined by Tang method, were higher than those of the virgin copolymer. The significant increase of (E?), observed with PEMAN20/OMMT (1 wt%) confirmed the change in the degradation mechanism with OMMT loading and the ratio of intercalated/exfoliated structures

332

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

OpenAIRE

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

Brij Bhushan Tewari

2004-01-01

333

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

Directory of Open Access Journals (Sweden)

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

Supamattaya, K.

2005-02-01

334

High sensitive diagnostic technique for virus gene using radioisotope. Development of PCR in situ hybridization and its application  

International Nuclear Information System (INIS)

An animal model, experimentally induced squamous cell carcinoma was produced in hamster mucosa to establish a carcinogenic system inducible by interaction of a virus and chemical(s). Human hydatid mole and cholioepithelioma were chosen as the target subjects. Several tumor cells and host cells were isolated under microscopy and DNA was extracted from these cells to indentify the respective origins (maternal, paternal or host origin). The base sequence of HLADRB region was analyzed by PCR using synthetic primer and the tissue localization was examined by PCR in situ hybridization. A PCR product of 82 bp was found in 15 of 17 samples and there were 2 samples in which the product was not detectable with the constructed primer and 6 samples were negative. While significant differences were not observed by in situ hybridization compared with the negative control. (M.N.)

335

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

OpenAIRE

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

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

2011-01-01

336

Using respirometric techniques and fluorescent in situ hybridization to evaluate the heterotrophic active biomass in activated sludge.  

Science.gov (United States)

The separation and accurate quantification of active biomass components in activated sludge is of paramount importance in models, used for the management and design of waste water (WW) treatment plants. Accurate estimates of microbial population concentrations and the direct, in situ determination of kinetic parameters could improve the calibration and validation of existing models of biological nutrient removal activated sludge systems. The aim of this study was to obtain correlations between heterotrophic active biomass (Z(BH)) concentrations predicted by mathematical models and quantitative information obtained by Fluorescent in situ hybridizations (FISH). Respirometric batch test were applied to mixed liquors drawn from a well-defined parent anoxic/aerobic activated sludge system to quantify the Z(BH) concentrations. Similarly fluorescent labeled, 16S rRNA-targeted oligonucleotide probes specific for ammonia and nitrite oxidizers were used in combination with DAPI staining to validate the Z(BH) active biomass component in activate sludge respirometric batch tests. For the direct enumeration and simultaneous in situ analysis of the distribution of nitrifying bacteria, in situ hybridization with oligonucleotide probes were used. Probes (NSO 1225, NSR 1156, and NIT3) were used to target the nitrifiers and the universal probe (EUB MIX) was used to target all Eubacteria. Deducting the lithoautotrophic population from the total bacteria population revealed the Z(BH) population. A conversion factor of 8.49 x 10(-11) mg VSS/cell was applied to express the Z(BH) in terms of COD concentration. Z(BH) values obtained by molecular probing correlated closely with values obtained from the modified batch test. However, the trend of consistently poor correspondence of measured and theoretical concentrations were evident. Therefore, the focus of this study was to investigate alternative technology, such as FISH to validate or replace kinetic parameters which are invariably incorporated into models. PMID:17311354

Ismail, A; Wentzel, M C; Bux, F

2007-10-15

337

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

OpenAIRE

Our understanding of formation processes, physical properties and climate/health effects of organic aerosols is still limited in part due to limited knowledge of organic aerosol composition. We present speciated measurements of organic aerosol composition by two methods: in-situ thermal-desorption proton-transfer-reaction mass spectrometry (TD-PTR-MS) and offline two-dimensional gas chromatography with a time-of-flight mass spectrometer (GC×GC/TOF-MS). 153 ...

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

2014-01-01

338

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

Science.gov (United States)

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

Xia, Dengning; Gan, Yong; Cui, Fude

2014-01-01

339

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english OBJECTIVES: To compare bar displacement and complication rates in three retrospective series of patients operated on by the same surgical team. METHOD: A retrospective medical chart analysis of the three patient series was performed. In the first series, the original, unmodified Nuss technique was p [...] erformed. In the second, we used the ''third point fixation'' technique,and in the last series, the correction was performed with modifications to the stabilizer and stabilizer position. RESULTS: There were no deaths in any of the series. Minor complications occurred in six (4.9%) patients: pneumothorax with spontaneous resolution (2), suture site infection (2), and bar displacement without the reoperation need (2). Major complications were observed in eight (6.5%) patients: pleural effusion requiring drainage (1), foreign body reaction to the bar (1), pneumonia and shock septic (1), cardiac perforation (1), skin erosion/seroma (1), and displacement that necessitated a second operation to remove the bar within the 30 days of implantation (3). All major complications occurred in the first and second series. CONCLUSION: The elimination of fixation wires, the use of shorter bars and redesigned stabilizers placed in a more medial position results in a better outcome for pectus excavatum patients treated with the Nuss technique. With bar displacement and instability no longer significant postoperative risks, the Nuss technique should be considered among the available options for the surgical correction of pectus excavatum in pediatric patients.

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

1743-17-01

340

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

Directory of Open Access Journals (Sweden)

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

Ali Ahmad Ghotbi

2012-04-01

341

Instrumentation and techniques for monitoring the air emissions during in-situ oil/fuel burning operations  

International Nuclear Information System (INIS)

Data was presented from the testing of a portable real-time aerosol monitor during a meso-scale in-situ diesel fuel fire. The monitors tested were MIE Inc's., RAM-1 and DataRAM monitors which are commonly used in the occupational health and safety industry. They allow for the continuous measurement of aerosol levels. In-situ burning has evolved substantially in recent years and is considered to be a viable oil spill countermeasure. However, research continues regarding the environmental impact of in-situ burning. For this continuous monitoring study, three RAM-1 and two or three DataRAM monitors were placed in a cluster close to each other; data was recorded using an external data logger. The multiple values from the RAM-1 were averaged over a period of one minute. Results showed that the reproducibility of the average readings recorded during the trials were not at levels expected for scientific research. The results of the instruments clustered together was influenced by the location of the monitors relative to the particulates in the air. This would be of concern when comparing individual results to air quality standards. 8 refs., 5 tabs., 20 figs

342

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-08-07

343

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

International Nuclear Information System (INIS)

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

344

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

International Nuclear Information System (INIS)

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

345

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

Energy Technology Data Exchange (ETDEWEB)

Two methods of estimating soot production by in-situ oil and fuel fires were described. Much refining is needed in current measurement estimation techniques, since no method can accurately measure soot production from large-scale fires. One method which may have potential is the use of laser particle counters to count particles by size as they move overhead. Studies of oil and fuel fires have shown that there is significant gas separation between the plume and the surface, and that there is also significant soot precipitation out of the plume near the fire. Data from many burns has shown that the CO{sub 2} is often ten times lower in the plume than on the surface. Most estimation methods over-estimate soot production by as much as a factor of 10. The value of soot produced varies significantly down-plume because of the precipitation of material. True values, regarding soot production by in-situ oil fires are necessary to establish a mass balance of burning, to understand the air emissions of in-situ fires, and to establish guidelines for the burning of various fuels. 71 refs., 11 tabs., 8 figs.

Fingas, M.F.; Li, K.; Ackerman, F.; Wang, Z.; Lambert, P.; Gamble, L. [Environment Canada, Ottawa, ON (Canada). Emergencies Science Div.; Trespalacios, M.J.; Schuetz, S. [REAC/Weston, Edison, NJ (United States); Turpin, R.; Campagna, P. [Environmental Protection Agency, Edison, NJ (United States)

1996-09-01

346

The influence of additives on the morphology and stability of roll-to-roll processed polymer solar cells studied through ex situ and in situ X-ray scattering  

DEFF Research Database (Denmark)

The effect of twelve different additives on organic solar cells with an active layer based on poly-3- hexylthiophene (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) has been studied in this work and tested for suitability in roll-to-roll slot-die coating. Three of the twelve additives increased the solar cell efficiency while the rest showed no effect or a negative influence on the efficiency and coatability. In cases where the additive caused an increase in performance the relation to surface topography and the structure was investigated using Atomic Force Microscopy (AFM), UV-Vis Spectroscopy and Small Angle X-ray Scattering (SAXS) for cells prepared with 1-chloronaphthalene (CN), N-methyl-2-pyrrolidone (NMP) and 1,3-dimethyl-barbituric acid (BARB) as processing additives. The studies suggested that the use of these additives resulted in films with improved morphology and electrical properties of the active layer. The effect of the CN on structural evolution during different solvent evaporation and annealing times was further investigated with an in situ roll-to-roll X-ray study. Lifetime studies under continuous illumination were used to assess the impact of the additives on the stability of the prepared devices that had an active area of 1 cm2.

Zawacka, Natalia Klaudia; Andersen, Thomas Rieks

2014-01-01

347

Multiple phase inversion of emulsions stabilized by in situ surface activation of CaCO3 nanoparticles via adsorption of fatty acids.  

Science.gov (United States)

The in situ surface activation of raw CaCO(3) nanoparticles by interaction with a series of sodium carboxylates of chain length between 6 and 12 as well as sodium 2-ethylhexylsulfosuccinate (AOT) was studied, and the impact of this on the stabilization and phase inversion of toluene-water emulsions was assessed. By using complementary experiments including measurement of particle zeta potentials, adsorption isotherms of amphiphile, and relevant contact angles, the mechanism of this activation was revealed. The results show that hydrophilic CaCO(3) nanoparticles can be surface activated by interaction with sodium carboxylates and AOT even if they are not surface-active themselves. Both the electrostatic interaction between the positive charges on particle surfaces and the negative charges of anionic amphiphile headgroups and the chain-chain interactions of the amphiphile result in monolayer adsorption of the amphiphile at the particle-water interface. This transforms the particles from hydrophilic to partially hydrophobic such that they become surface-active and stabilize oil-in-water O/W(1) emulsions and induce O/W(1) ? water-in-oil W/O phase inversion, depending on the chain length of the carboxylate molecules. At high amphiphile concentration, bilayer or hemimicelle adsorption may occur at the particle-water surface, rendering particles hydrophilic again and causing their desorption from the oil-water interface. A second phase inversion, W/O ? O/W(2), may occur depending on the surface activity of the amphiphile. CaCO(3) nanoparticles can therefore be made good stabilizers of both O/W and W/O emulsions once surface activated by mixing with traces of suitable anionic amphiphile. PMID:22103933

Cui, Z-G; Cui, C-F; Zhu, Y; Binks, B P

2012-01-10

348

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

International Nuclear Information System (INIS)

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

349

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

Directory of Open Access Journals (Sweden)

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

Mohamed Zellagui

2008-09-01

350

Reversible intercalation of large-capacity hemoglobin into in situ prepared titanate interlayers with enhanced thermal and organic medium stabilities.  

Science.gov (United States)

The exfoliated single-layer titanate can rapidly restack and reversibly release heme protein simply by adjustment of the pH value. The composites have regularly layered structure and powdery morphology by their ideal layer-to-layer assembly, which provides the titanate nanosheet an unusual specific intercalation capacity of 5900 mg g(-1) for the protein. The bound and released proteins keep active relative to the intact protein. The hemoglobin thermal and organic solvent stabilities are improved by the protective environment of the titanate host. PMID:15518518

Wang, Qigang; Gao, Qiuming; Shi, Jianlin

2004-11-01

351

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

Science.gov (United States)

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

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

2015-01-01

352

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

OpenAIRE

Review of the mobility of trace elements in soils and of the use of physico-chemical stabilization as an in situ management strategy for contaminated sites. Industrial activities have greatly impacted the quality of the biophysical environment in some areas. This review focuses on the consequences of soil contamination by metallic trace elements: what factors determine the mobility of contaminants in soils and what remediation practices based upon physico-chemical stabilization can be used in...

Lie?nard, A.; Colinet, G.

2014-01-01

353

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

International Nuclear Information System (INIS)

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

354

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

Science.gov (United States)

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

Minami, Hideto; Mizuta, Yusuke; Suzuki, Toyoko

2013-01-15

355

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

International Nuclear Information System (INIS)

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

356

Microstructural stability and mechanical properties of in-situ reinforced Ti-8.5Al-1B-Si  

International Nuclear Information System (INIS)

The application of conventional titanium alloys at high temperature is limited by their metastable microstructure, high oxidation rates and loss of strength. Dispersion strengthening and particle reinforcement of titanium alloys offers the promise of substantial property improvement at elevated temperature. The intent of this work is to evaluate the post-extruded microstructural stability of two kinds of dispersoids: spherical titanium silicides and rod shaped titanium borides in a Ti-8.5Al-1B-1Si (wt% alloy). Several heat treatments were made in two different atmospheres, namely air and argon. Section 2 will provide detailed experimental procedures. Section 3 will deal with the effect of time of heat treatment on coarsening behavior of the dispersoids at different temperatures. Sections 4 will discuss the coarsening behavior of the dispersoids as a function of temperature at different times. Section 5 will provide some generalized conclusions

357

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

International Nuclear Information System (INIS)

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

358

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

International Nuclear Information System (INIS)

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

359

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

Science.gov (United States)

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

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

2013-09-01

360

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

Directory of Open Access Journals (Sweden)

Full Text Available Our understanding of formation processes, physical properties and climate/health effects of organic aerosols is still limited in part due to limited knowledge of organic aerosol composition. We present speciated measurements of organic aerosol composition by two methods: in-situ thermal-desorption proton-transfer-reaction mass spectrometry (TD-PTR-MS and offline two-dimensional gas chromatography with a time-of-flight mass spectrometer (GC×GC/TOF-MS. 153 compounds were identified using the GC×GC/TOF-MS, 123 of which were matched with 64 ions observed by the TD-PTR-MS. A reasonable overall correlation of 0.67 (r2 was found between the total matched TD-PTR-MS signal (sum of 64 ions and the total matched GC×GC/TOF-MS signal (sum of 123 compounds. A reasonable quantitative agreement between the two methods was observed for most individual compounds with concentrations which were detected at levels above 2 ng m?3 using the GC×GC/TOF-MS. The analysis of monocarboxylic acids standards with TD-PTR-MS showed that alkanoic acids with molecular masses below 290 amu are detected well (recovery fractions above 60%. However, the concentrations of these acids were consistently higher on quartz filters (quantified offline by GC×GC/TOF-MS than those suggested by in-situ TD-PTR-MS measurements, which is consistent with the semivolatile nature of the acids and corresponding positive filter sampling artifacts.

J. Timkovsky

2014-12-01

361

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

Science.gov (United States)

Our understanding of formation processes, physical properties and climate/health effects of organic aerosols is still limited in part due to limited knowledge of organic aerosol composition. We present speciated measurements of organic aerosol composition by two methods: in-situ thermal-desorption proton-transfer-reaction mass spectrometry (TD-PTR-MS) and offline two-dimensional gas chromatography with a time-of-flight mass spectrometer (GC×GC/TOF-MS). 153 compounds were identified using the GC×GC/TOF-MS, 123 of which were matched with 64 ions observed by the TD-PTR-MS. A reasonable overall correlation of 0.67 (r2) was found between the total matched TD-PTR-MS signal (sum of 64 ions) and the total matched GC×GC/TOF-MS signal (sum of 123 compounds). A reasonable quantitative agreement between the two methods was observed for most individual compounds with concentrations which were detected at levels above 2 ng m-3 using the GC×GC/TOF-MS. The analysis of monocarboxylic acids standards with TD-PTR-MS showed that alkanoic acids with molecular masses below 290 amu are detected well (recovery fractions above 60%). However, the concentrations of these acids were consistently higher on quartz filters (quantified offline by GC×GC/TOF-MS) than those suggested by in-situ TD-PTR-MS measurements, which is consistent with the semivolatile nature of the acids and corresponding positive filter sampling artifacts.

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

2014-12-01

362

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

Directory of Open Access Journals (Sweden)

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

Naresh K. Tanwani*1

2014-03-01

363

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

International Nuclear Information System (INIS)

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

364

Stabilization of NaCl-containing cuttings wastes in cement concrete by in situ formed mineral phases.  

Science.gov (United States)

Disposal of NaCl-containing cuttings is a major environmental concern due to the high solubility of chlorides. The present work aims at reducing the solubility of chloride by encapsulation in low permeability matrix as well as lowering its solubility by trapping into low-solubility phases. Both the studied materials were cuttings from an oil-based mud in oil drillings containing about 50% of halite, and cuttings in water-based mud from gas drilling containing 90% of halite. A reduction in the amount of dissolved salt from 41 to 19% according to normalized leaching tests was obtained by addition of potassium ortho-phosphate in the mortar formula of oil-based cuttings, while the aluminium dihydrogeno-phosphate is even more efficient for the stabilization of water-based cuttings with a NaCl content of 90%. Addition of ortho-phosphate leads to form a continuous and weakly soluble network in the cement matrix, which reduces the release of salt. The formed mineralogical phases were apatite and hydrocalumite. These phases encapsulate the salt grains within a network, thus lowering its interaction with water or/and trap chloride into low-solubility phases. The tested approaches allow to develop a confinement process of NaCl-containing waste of various compositions that can be applied to wastes, whatever the salt content and the nature of the drilling fluids (water or oil). PMID:19631465

Filippov, Lev; Thomas, Fabien; Filippova, Inna; Yvon, Jacques; Morillon-Jeanmaire, Anne

2009-11-15

365

Maintaining stability of standalone Micro-Grid by employing electrical and mechanical fault ride through techniques upon fixed speed wind generation systems  

International Nuclear Information System (INIS)

Highlights: • This paper presented two fault ride through techniques for fixed speed wind systems. • The first technique is implemented by inserting a series resistance with the terminals of wind generator. • Second technique is performed by adapting the gear ratio to spill some mechanical power. - Abstract: This study presents two different Fault Ride Through (FRT) techniques to keep and restore stability of Fixed Speed Wind Generation system (FSWGs) installed in standalone Micro-Grid (MG). The first technique is an electrical FRT and is implemented by inserting a series resistance with the terminals of FSWGs during fault to maintain reasonable value of terminal voltage and consequently help stability restoration. The second controller is a mechanical FRT controller and is performed by change the gear ratio of wind generation systems to spill part of extracted mechanical power and consequently improving stability issue. Obtained results proved that each controller able to maintain the stability of FSWGs under the most severe disturbance conditions (400 ms three phase fault at FSWGs terminals). The first controller is faster than the second controller in restoring FSWGs stability. Superior results and performances are obtained when the two FRT techniques are employed simultaneously. Without employing any one of the two FRT techniques, FSWGs is not able to maintain or restore its stability after fault clearing. Consequently, MG will lose one of its micro-sources and cannot keep its stability during the standalone mode, unless load shedding strategy is activated. The two proposed controllers are simple, effective, and economical attractive

366

Determination of stability constant of cerium and transplutonium elements with organic acid using ion exchange and spectrophotometric technique  

International Nuclear Information System (INIS)

From the beginning of production of the transplutonium elements, modern and developed techniques for separation of these elements from each other have been applied. By using a strong complexing agent, actinides can be separated from lantanides in one stage process. For this reason, determination of their stability constants with organic acids especially amino-polycarboxylic acid is very important. These acids are stable against ionizing radiation, and are used as a strong separator for separation and purification of transplutonium elements in the reprocessing of spent fuels. The determination of stability constants of these acids have usually been investigated by potentiometric, polarography and solvent extraction methods. The purpose of this research work is determination of the stability constants of cerium and transplutonium elements using ion exchange and spectrophotometric methods. In this paper, the stability constants of Am (III), Cm (III) and Ce (III) with b-hydroxyiminodiacetic acid (H2HIDE), taurin, N.N. diacetic acid (H3TDE) and N-2 picolyl-iminodiacetic acid (H2PIDE) complexes at constant ionic strength have been investigated. By ion exchange method, the stability constant of chelates has been calculated on the basis of ligand concentration and distribution coefficient between resin and liquid phase in the presence and absence of complex at constant ionic strength and various PH. Tetravalent cerium like americium and curium with amino-polycarboxylic acid forms chelate which is soluble in water. By spectrophotometric method tetravalent americium absorbs at 5032A wave length, and by adding complex and titrating it, new peaks will appear between 5032A and 5100A. Appearance of these peaks accompanied by increase in wave length and means that the water molecules surrounding the central atom are removed by ligands and new bonds between ligand and central atom have been formed. The results gained from these two methods have been compared, and they show that the ion exchange is a very accurate method for stability constant determination

367

High sensitive diagnostic technique for virus gene using radioisotope. Development of PCR in situ hybridization and its application  

International Nuclear Information System (INIS)

In order to elucidate how in vivo localization on traced amount of virus present in a texture progressed in a cancer process, this study aimed to conduct technical development to clarify quantitative and qualitative differences of virus genome, and man gene at each cell unit. In 1997 fiscal year, in order to make analysis on each cell secure according to microdissection established in last fiscal year, analysis on base alignment of gene held by each cell was conducted, and establishment of a method to clarify its diversity was examined. As a result, it was found that a genetic information was held in each cell, of which information could be distinguished in a range. And, it could be established that analysis using PCR in situ hybridization method could not give any advancement changeable with conventional method as well, but that analysis using microdissection method could pay this price. (G.K.)

368

Growth mechanism of in situ synthesized TiBw in titanium matrix composites prepared by common casting technique  

International Nuclear Information System (INIS)

Titanium matrix composites reinforced with TiB and RE2O3 (RE = rare earth metal) were fabricated by a non-consumable arc-melting technology utilizing chemical reaction between titanium, B2O3 and RE. Microstructural characterization of in situ synthesized TiB was performed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). When the volume percentage is relatively low, the TiB shows a typical fine needle-shape due to the solidification process. The TiB whiskers have a B27 crystal structure and grow along the B27 [010] direction. Based on Density Functional Theory (DFT), the surface energies of B27 (100), (101), (101-bar ) and (001) planes were calculated. The results show that the cross sections of TiB whiskers are hexagonal and consist of (100), (101), (101-bar ) planes

369

In situ HVEM studies on the effects of electron-irradiation on the thermal stability of Ni-based amorphous alloys  

International Nuclear Information System (INIS)

In situ high voltage electron microscope (HVEM) studies on the thermal stability of splat-cooled Ni-based amorphous alloys were made and three kinds of accelerated crystallization modes were observed during bombardment by focused 1000 keV electrons. In one case the crystalline grains induced by irradiation were coarser near the edge of the irradiated region (IR) than in other parts. This type of crystallization was observed in Ni75B17Si8 and Ni75B15Si8C2 amorphous alloys subjected to a continuous increase in temperature of irradiation. The second case was one where there was no appreciable difference in size distribution of the crystalline grains throughout the IR. This type was observed in a Ni80P10B10 amorphous alloy which again was subjected to a continuous increase in irradiation temperature and also observed in Ni75B17Si8 amorphous alloy irradiated during isothermal annealing. In these two cases, the crystalline grains induced during irradiation did not cover the whole of the IR before crystallization started in the unirradiated region. In the third case, however, the amorphous phase completely disappeared from the IR before crystallization in the unirradiated region occurred. This type of crystallization was observed in Ni80P20 amorphous alloy whilst the temperature was being increased continuously derature was being increased continuously during irradiation. (author)

370

In situ investigation of growth and thermal stability of ultrathin Si layers on the HfO2/Si (100) high-? dielectric system  

Science.gov (United States)

We report on growth behavior and thermal stability of ultrathin (0.5-12nm) Si layers grown on HfO2 (3nm )/Si (100) by pulsed laser deposition (PLD) as investigated by in situ x-ray photoelectron spectroscopy and low-energy ion scattering spectroscopy. Layer-by-layer growth of ultrathin Si overlayer was observed during room-temperature deposition, while an island-like growth behavior dominated at T ?900K. Vacuum annealing of the Si(3.5nm )/HfO2 (3nm)/Si (100) structure resulted in Si crystallization and coarsening. The process was accompanied by hafnium oxide reduction at the surface causing HfO2 layer decomposition and hafnium silicide formation. These interface reactions depended on the thickness of the Si cap layer—the thicker (12nm ) Si layer on HfO2 (40nm )/Si (100) appeared to be stable at least up to T =1200K. An ultrathin (0.3nm) Al2O3 layer PLD deposited between HfO2 and the Si overlayer also effectively inhibited the reactions up to T =1200K.

Lebedinskii, Yu. Yu.; Zenkevich, A.; Gusev, E. P.; Gribelyuk, M.

2005-05-01

371

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

International Nuclear Information System (INIS)

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

372

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

Science.gov (United States)

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

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

2014-09-01

373

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

International Nuclear Information System (INIS)

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

374

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1996-11-01

375

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

Directory of Open Access Journals (Sweden)

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

B. Mouriño-Carballido

2009-08-01

376

Estandarización de la técnica de hibridación in situ para la detección de Streptococcus agalactiae en tejidos de tilapia roja (Oreochromis sp.) y su uso potencial en estudios epidemiológicos y de patogénesis / Standardization of in situ hybridization technique for Streptococcus agalactiae detection in tilapia red tissues (Oreochromis sp.) and its potential use in epidemiological and pathogenesis assays  

OpenAIRE

Pulido Bravo, Edgar Andrés (2010) Estandarización de la técnica de hibridación in situ para la detección de Streptococcus agalactiae en tejidos de tilapia roja (Oreochromis sp.) y su uso potencial en estudios epidemiológicos y de patogénesis / Standardization of in situ hybridization technique for Streptococcus agalactiae detection in tilapia red tissues (Oreochromis sp.) and its potential use in epidemiological and pathogenesis assays. Maestría thesis, Universidad Nacional de Colom...

Pulido Bravo, Edgar Andre?s

2010-01-01

377

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

Science.gov (United States)

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

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

2008-01-01

378

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

DEFF Research Database (Denmark)

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

Lira-Cantu, Monica; Tanenbaum, David M.

2012-01-01

379

In situ technique for synthesizing multiple ceramic particulates reinforced titanium matrix composites (TiB + TiC + Y2O3)/Ti  

International Nuclear Information System (INIS)

In situ synthesized titanium matrix composites reinforced with multiple ceramic particulates including TiB, TiC and Y2O3 were fabricated by non-consumable arc-melting technique utilizing the chemical reaction among Ti, B2O3, B4C and Y. The thermodynamic feasibility of the in situ reactions has been considered. X-ray diffraction (XRD) was used to identify the phases in the composites. Microstructures of the composites were observed by means of optical microscope (OM), scanning electron microscope (SEM) and electron probe. It is concluded that multiple reinforcements are synthesized and they show different shapes: TiB grows in needle shape; TiC grows in near-equiaxed and rod-like shapes; Y2O3 grows in near-equiaxed shapes when the content of Y is 0.6 wt.% and grows in dendritic shapes when the content of Y increases to 1.8 wt.%. Reinforcements TiB, TiC and Y2O3 are distributed uniformly in the titanium matrix

380

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

International Nuclear Information System (INIS)

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

381

Assessment of microbial methane oxidation above a petroleum-contaminated aquifer using a combination of in situ techniques  

Science.gov (United States)

Emissions of the greenhouse gas CH4, which is often produced in contaminated aquifers, are reduced or eliminated by microbial CH4 oxidation in the overlying vadose zone. The aim of this field study was to estimate kinetic parameters and isotope fractionation factors for CH4 oxidation in situ in the vadose zone above a methanogenic aquifer in Studen, Switzerland, and to characterize the involved methanotrophic communities. To quantify kinetic parameters, several field tests, so-called gas push-pull tests (GPPTs), with CH4 injection concentrations ranging from 17 to 80 mL L-1 were performed. An apparent Vmax of 0.70 ± 0.15 mmol CH4 (L soil air)-1 h-1 and an apparent Km of 0.28 ± 0.09 mmol CH4 (L soil air)-1 was estimated for CH4 oxidation at 2.7 m depth, close to the groundwater table. At 1.1 m depth, Km (0.13 ± 0.02 mmol CH4 (L soil air)-1) was in a similar range, but Vmax (0.076 ± 0.006 mmol CH4 (L soil air)-1 h-1) was an order of magnitude lower. At 2.7 m, apparent first-order rate constants determined from a CH4 gas profile (1.9 h-1) and from a single GPPT (2.0 ± 0.03 h-1) were in good agreement. Above the groundwater table, a Vmax much higher than the in situ CH4 oxidation rate prior to GPPTs indicated a high buffer capacity for CH4. At both depths, known methanotrophic species affiliated with Methylosarcina and Methylocystis were detected by cloning and sequencing. Apparent stable carbon isotope fractionation factors ? for CH4 oxidation determined during GPPTs ranged from 1.006 to 1.032. Variability was likely due to differences in methanotrophic activity and CH4 availability leading to different degrees of mass transfer limitation. This complicates the use of stable isotopes as an independent quantification method.

Urmann, Karina; Schroth, Martin H.; Noll, Matthias; Gonzalez-Gil, Graciela; Zeyer, Josef

2008-06-01

382

Dynamic displacement measurements with a stabilized fiber Michelson interferometer based on quadratrue-phase-tracking technique  

Science.gov (United States)

A highly stabilized dynamic displacement measurement system, which employs fiber Bragg gratings to interleave two fiber Michelson interferometers that share the common interferometric optical path, is presented. The phase change in the interferometric signals of the two fiber Michelson interferometers is tracked respectively by maintaining the phase difference in quadrature with two electronic feedback loops. One of the fiber interferometers is used to stabilize the system by the use of an electronic feedback loop to eliminate the influences that result from the environmental disturbances, while the other fiber interferometer is used for the measurement by employing another electronic feedback loop to track the phase change in the interferometric signal. The system is able to measure dynamic displacement and provide a sense of direction of the displacement at the same time. The dynamic displacement with frequencies ranging from 0.1 Hz to 200 Hz and with a maximum amplitude of 60 ?m can be measured, and the measurement resolution can reach 10 nm.

Chen, Zhimin; Xie, Fang; Li, Min; Feng, Qibo

2010-01-01

383

Application of electrophoresis technique for evaluating stability constant of ternary complexes  

Energy Technology Data Exchange (ETDEWEB)

A method involving the use of paper electrophoresis is described for the study of equilibria in mixed ligand complex systems in solution. This method is based on the development of a spot by migration of a metal ion, with the complexants added in the background electrolyte (0.1 M perchloric acid). For the study of ternary complexes, the concentration of adenosine monophosphate (AMP) is kept constant, while that of a second ligand nitrilotriacetate (NTA) is varied. A graph of mobility against [minus]log [NTA] is used to obtain information on the formation of mixed ligand complexes and to calculate the stability constants. The overall stability constants of complexes of M-AMP and M - AMP - NTA system have been found to be 10[sup 2.8], 10[sup 8.2] for Zn(II) and 10[sup 2.9], 10[sup 8.5] for Ni(II) complexes, respectively, at 30 C and [mu] = 0.1.

Yadav, A. (Univ. of Allahabad (India))

1993-03-01

384

Application of stabilization techniques in the dynamic analysis of multibody systems  

Directory of Open Access Journals (Sweden)

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

Hajžman M.

2007-11-01

385

Correlation-based technique for automated tunable diode laser scan stabilization  

Science.gov (United States)

A software-based method for real-time, active stabilization of tunable diode laser spectral scans is described. The procedure is suitable for use with field and laboratory instrumentation where automated, unattended spectrometer operation is required. An autocorrelation of two high-resolution reference gas infrared spectra is computed at regular intervals, and the location of the maximum value of the autocorrelation provides the relative abscissa shift between the spectra. Small adjustments to the laser scan parameters are thereby made to ensure that drifts in the laser output frequency are tracked and compensated. Calculations required for stabilization of a 512-point spectrum can be completed in under 25 ms using an inexpensive, moderate-speed, array processor installed in a PC.

May, Randy D.

1992-01-01

386

Subsonic static and dynamic stability characteristics of the test technique demonstrator NASP configuration  

Science.gov (United States)

The paper describes the procedure used for and the results obtained of wind-tunnel tests of the National Aerospace Plane (NASP) configuration, which were conducted in the NASA Langley Research Center High Speed Tunnel using a blended body NASP configuration designed by the research center. Static and dynamic stability characteristics were measured at Mach numbers 0.3, 0.6, and 0.8. In addition to tests of the baseline configuration, component buildup tests with a canard surface and with a body flap were carried out. Results demonstrated a positive static stability of the baseline configuration, except at the higher angles of attack at Mach 0.8. A good agreement was found between the inphase dynamic parameters and the corresponding static data.

Boyden, Richmond P.; Dress, David A.; Fox, Charles H., Jr.; Huffman, Jarrett K.; Cruz, Christopher I.

1993-01-01

387

Evaluation of ventral stabilization techniques for thoracolumbar fractures by helical computer tomography  

International Nuclear Information System (INIS)

Purpose: To assess the volumetric change of the implanted graft in thoracolumbar fractures treated with dorsal and ventral stabilization. Comparison of two methods of ventral stabilization to avoid loss of correction and rekyphosis. Material and Methods: 38 patients with 40 thoracolumbar fractures were treated with a tricortical bone graft of the pelvis (n = 27) or bone cement (SRS: skeletal repair system, n = 13), measuring the volume and the length of the implanted graft by helical CT (Somatom Plus 4, Siemens): after ventral stabilization, preoperative before and six month after removal of the fixateur interne. The bone and SRS volume were assessed as a product of slice thickness and cross-section, the length of the implanted graft was measured by the cranial and caudal table position. Results: Loss of graft volume between implantation and explantation of the fixateur interne was 24.3%, and between implantation and the check six months after removal 40.5%; loss of length until removal 14.6% and between implantation and six months after the removal 24.1%; no difference between the tricortical bone graft and the skeletal repair system. Conclusion: Volumetric and length study assessed by CT shows a loss of volume and length of the tricortical bone graft and the skeletal repair system with no dependence on the used material. CT enables an exact and feasible assessment of the localisation, volume, size and possible complications of the implanted bone graft and SRS. The cof the implanted bone graft and SRS. The considerable loss of volume and length of the graft is one of the reasons correction loss and rekyphosis in the stabilization of the thoracolumbar fractures. (orig.)

388

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

Science.gov (United States)

Suppression of magnetic islands driven by the neoclassical tearing mode (NTM) is necessary for efficient and sustained operation of tokamak fusion reactors. Compensating for the lack of bootstrap current, due to the pressure profile flattening in the magnetic island, by a localized electron cyclotron current drive (ECCD) has been proved experimentally as an effective method to stabilize NTMs. The effectiveness of this method is limited in practice by the uncertainties in the width of the island, the relative position between the island and the beam, and the ECCD power threshold for NTM stabilization. Heuristic search and suppress algorithms have been proposed and shown effective in improving the alignment of the ECCD beam with the island, using only an estimate of the island width. Making use of this estimate, real-time, non-model-based, extremum-seeking optimization algorithms have also been proposed not only for beam steering but also for power modulation in order to minimize the island-beam misalignment and the time required for NTM stabilization. A control-oriented dynamic model for the effect of ECCD on the magnetic island is proposed in this work to enable both control design and performance analysis of these minimum-seeking type of controllers. The model expands previous work by including the impact of beam modulation parameters such as the island-beam phase mismatch and the beam duty-cycle on the island width dynamics.

Wehner, W.; Schuster, E.

2012-07-01

389

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

Directory of Open Access Journals (Sweden)

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

Dumur Catherine I

2004-05-01

390

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

391

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

International Nuclear Information System (INIS)

During the last decade, interest in the pyrometallrugical treatment of spent nuclear fuel has been drastically increased because of its relatively low processing cost as well as its proliferation resistance of the nuclear fuel cycles. Similar but unique researches have been conducted by several institutions in various countries using their own strategies, i.e. IFR fuel cycle in ANL, DOVITA process in RIAR and ,OMEGA program in JAERI. The Korea Atomic Energy Research Institute (KAERI) is developing an electrorefining process using PWR surrogate spent fuels. In this fuel cycle, uranium and TRU oxides are electrochemically reduced while the rare earth oxides are intact. Thus, the prepared ingot consists of metallic uranium, TRU and rare earth oxides. The main scientific and technological interests in the electrorefining process using the electrochemically reduced fuel ingot are how to effectively partition a spent fuel into Uranium, TRU and fission products (FPs). Furthermore a systematic consideration for a series of pyrochemical treatments of the spent fuel which includes not only an electrorefining but also a cathode process has not been reported. Hence in this study, we would like to report on the methodology to recycle PWR fuel for a future use and some important results in the electrorefining of the uranium and the cathode process of the deposit. Also, in-situ UV-vis absorption spectrometry was adopted to observe the behavior of Nd2O3 in molteor of Nd2O3 in molten salt encouraged by the recent results of Yamana et. al

392

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

Directory of Open Access Journals (Sweden)

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

K. U. Heeschen

2011-12-01

393

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

Directory of Open Access Journals (Sweden)

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

N. Engler

2008-11-01

394

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

Science.gov (United States)

MicroRNAs (miRNAs) are small, noncoding RNA molecules that negatively regulate gene expression and control a wide range of cellular processes. Extracellular forms of miRNA circulating in the bloodstream (circulating miRNA, c-miRNA) are of increasing interest for their potential as biomarkers and long-range physiological signaling molecules. Precise measurement of intracellular miRNA expression is possible but can be challenging, especially in the context of specialized tissue niches in vivo. The accurate measurement of extracellular miRNA presents other obstacles stemming from their low concentrations and confounding sources of intracellular miRNA that contaminate RNA extraction protocols. Here, we describe multiple methods to isolate extracellular miRNA from cell culture media, serum, and plasma in order to accurately measure their variable expression under diff