WorldWideScience

Sample records for basin deactivation waste

  1. 340 waste handling complex: Deactivation project management plan

    International Nuclear Information System (INIS)

    This document provides an overview of the strategy for deactivating the 340 Waste Handling Complex within Hanford's 300 Area. The plan covers the period from the pending September 30, 1998 cessation of voluntary radioactive liquid waste (RLW) transfers to the 340 Complex, until such time that those portions of the 340 Complex that remain active beyond September 30, 1998, specifically, the Retention Process Sewer (RPS), can also be shut down and deactivated. Specific activities are detailed and divided into two phases. Phase 1 ends in 2001 after the core RLW systems have been deactivated. Phase 2 covers the subsequent interim surveillance of deactivated and stand-by components during the period of continued RPS operation, through the final transfer of the entire 340 Complex to the Environmental Restoration Contractor. One of several possible scenarios was postulated and developed as a budget and schedule planning case

  2. 340 waste handling complex: Deactivation project management plan

    Energy Technology Data Exchange (ETDEWEB)

    Stordeur, R.T.

    1998-06-25

    This document provides an overview of the strategy for deactivating the 340 Waste Handling Complex within Hanford`s 300 Area. The plan covers the period from the pending September 30, 1998 cessation of voluntary radioactive liquid waste (RLW) transfers to the 340 Complex, until such time that those portions of the 340 Complex that remain active beyond September 30, 1998, specifically, the Retention Process Sewer (RPS), can also be shut down and deactivated. Specific activities are detailed and divided into two phases. Phase 1 ends in 2001 after the core RLW systems have been deactivated. Phase 2 covers the subsequent interim surveillance of deactivated and stand-by components during the period of continued RPS operation, through the final transfer of the entire 340 Complex to the Environmental Restoration Contractor. One of several possible scenarios was postulated and developed as a budget and schedule planning case.

  3. Characterization and Regeneration of Pt-Catalysts Deactivated in Municipal Waste Flue Gas

    DEFF Research Database (Denmark)

    Rasmussen, Søren Birk; Kustov, Arkadii; Due-Hansen, Johannes;

    2006-01-01

    Severe deactivation was observed for industrially aged catalysts used in waste incineration plants and tested in lab-scale. Possible compounds that cause deactivation of these Pt-based CO oxidation catalysts have been studied. Kinetic observations of industrial and model catalysts showed that sil...... the activity of the deactivated catalysts. (c) 2006 Elsevier B.V. All rights reserved....

  4. Characterization and regeneration of Pt-catalysts deactivated in municipal waste flue gas

    International Nuclear Information System (INIS)

    Severe deactivation was observed for industrially aged catalysts used in waste incineration plants and tested in lab-scale. Possible compounds that cause deactivation of these Pt-based CO oxidation catalysts have been studied. Kinetic observations of industrial and model catalysts showed that siloxanes were the most severe catalyst poisons, although acidic sulfur compounds also caused deactivation. Furthermore, a method for on-site regeneration without shutdown of the catalytic flue gas cleaning system has been developed, i.e. an addition of H2/N2 gas to the off-gas can completely restore the activity of the deactivated catalysts. (author)

  5. Safe Shutdown and Deactivation of the 105-K Disassembly Basin at the Savannah River Site

    International Nuclear Information System (INIS)

    Nuclear production reactors at the Savannah River Site (SRS) were operated for several years in support of the United States nuclear weapons program. When this overall mission ended, the 105-K and 105-L reactors continued to perform vital missions, including the safe storage of spent nuclear fuel. A spent fuel consolidation effort is underway at SRS, and part of this effort was the safe shutdown and deactivation of the 105-K Disassembly Basin. 105-K ceased reactor operations in the early 1990s and was converted to a nuclear materials management facility. Although not originally designed for long-term storage, the 105-K Basin performed well as an interim, underwater location for reactor fuel and other radiation sources. Following the de-inventory of spent fuel in September 2002, the need to operate the 105-K Basin was eliminated.During production, the Disassembly Basins were used to temporarily store irradiated components removed from the reactor vessel. They are large concrete pools containing approximately 3.4 million gallons of water to provide cooling and shielding for the stored components. In support of this mission, the Basins were furnished with equipment for maintaining water parameters, monitoring radiation, and handling and reconfiguring the fuel components. Some of this equipment is located within the Basin structures themselves, and other pieces are located elsewhere in the local reactor areas. 105-K Basin deactivation activities included the lay-up, removal, or abandoning of this equipment. Eventual decommissioning activities will likely follow the Site-established plan to evaporate much of the Basin water and use the remaining water to grout-in-place residual contamination and scrap materials. Traditional deactivation projects include a substantial reduction in overall facility surveillance and maintenance activities and a relocation of all non-essential personnel to alternate work locations. In this case, however, the Disassembly Basin is not an

  6. Deactivation and regeneration of ZSM-5 zeolite in catalytic pyrolysis of plastic wastes

    International Nuclear Information System (INIS)

    Highlights: → Pyrolysis transforms plastic wastes in valuable liquids and gases useful as fuels or source of chemicals. → The use of ZSM-5 zeolite in pyrolysis favours the production of gases and of lighter and more aromatic liquids. → ZSM-5 zeolite is almost completely deactivated after one plastics pyrolysis experiment. → ZSM-5 zeolite used in plastic wastes pyrolysis can be regenerated by burning the deposited coke in an air stream. → Regenerated ZSM-5 recovers its activity and produces liquids and gases equivalent to those obtained with fresh catalyst. - Abstract: In this work, a study of the regeneration and reuse of ZSM-5 zeolite in the pyrolysis of a plastic mixture has been carried out in a semi-batch reactor at 440 deg. C. The results have been compared with those obtained with fresh-catalyst and in non-catalytic experiments with the same conditions. The use of fresh catalyst produces a significant change in both the pyrolysis yields and the properties of the liquids and gases obtained. Gases more rich in C3-C4 and H2 are produced, as well as lower quantities of aromatic liquids if compared with those obtained in thermal decomposition. The authors have proved that after one pyrolysis experiment the zeolite loses quite a lot of its activity, which is reflected in both the yields and the products quality; however, this deactivation was found to be reversible since after regeneration heating at 550 deg. C in oxygen atmosphere, this catalyst recovered its initial activity, generating similar products and in equivalent proportions as those obtained with fresh catalyst.

  7. PLUTONIUM FINISHING PLANT (PFP) 241-Z LIQUID WASTE TREATMENT FACILITY DEACTIVATION AND DEMOLITION

    International Nuclear Information System (INIS)

    Fluor Hanford, Inc. (FH) is proud to submit the Plutonium Finishing Plant (PFP) 241-Z liquid Waste Treatment Facility Deactivation and Demolition (D and D) Project for consideration by the Project Management Institute as Project of the Year for 2008. The decommissioning of the 241-Z Facility presented numerous challenges, many of which were unique with in the Department of Energy (DOE) Complex. The majority of the project budget and schedule was allocated for cleaning out five below-grade tank vaults. These highly contaminated, confined spaces also presented significant industrial safety hazards that presented some of the most hazardous work environments on the Hanford Site. The 241-Z D and D Project encompassed diverse tasks: cleaning out and stabilizing five below-grade tank vaults (also called cells), manually size-reducing and removing over three tons of process piping from the vaults, permanently isolating service utilities, removing a large contaminated chemical supply tank, stabilizing and removing plutonium-contaminated ventilation ducts, demolishing three structures to grade, and installing an environmental barrier on the demolition site . All of this work was performed safely, on schedule, and under budget. During the deactivation phase of the project between November 2005 and February 2007, workers entered the highly contaminated confined-space tank vaults 428 times. Each entry (or 'dive') involved an average of three workers, thus equaling approximately 1,300 individual confined -space entries. Over the course of the entire deactivation and demolition period, there were no recordable injuries and only one minor reportable skin contamination. The 241-Z D and D Project was decommissioned under the provisions of the 'Hanford Federal Facility Agreement and Consent Order' (the Tri-Party Agreement or TPA), the 'Resource Conservation and Recovery Act of 1976' (RCRA), and the 'Comprehensive Environmental Response, Compensation, and Liability Act of 1980

  8. PLUTONIUM FINISHING PLANT (PFP) 241-Z LIQUID WASTE TREATMENT FACILITY DEACTIVATION AND DEMOLITION

    Energy Technology Data Exchange (ETDEWEB)

    JOHNSTON GA

    2008-01-15

    Fluor Hanford, Inc. (FH) is proud to submit the Plutonium Finishing Plant (PFP) 241-Z liquid Waste Treatment Facility Deactivation and Demolition (D&D) Project for consideration by the Project Management Institute as Project of the Year for 2008. The decommissioning of the 241-Z Facility presented numerous challenges, many of which were unique with in the Department of Energy (DOE) Complex. The majority of the project budget and schedule was allocated for cleaning out five below-grade tank vaults. These highly contaminated, confined spaces also presented significant industrial safety hazards that presented some of the most hazardous work environments on the Hanford Site. The 241-Z D&D Project encompassed diverse tasks: cleaning out and stabilizing five below-grade tank vaults (also called cells), manually size-reducing and removing over three tons of process piping from the vaults, permanently isolating service utilities, removing a large contaminated chemical supply tank, stabilizing and removing plutonium-contaminated ventilation ducts, demolishing three structures to grade, and installing an environmental barrier on the demolition site . All of this work was performed safely, on schedule, and under budget. During the deactivation phase of the project between November 2005 and February 2007, workers entered the highly contaminated confined-space tank vaults 428 times. Each entry (or 'dive') involved an average of three workers, thus equaling approximately 1,300 individual confined -space entries. Over the course of the entire deactivation and demolition period, there were no recordable injuries and only one minor reportable skin contamination. The 241-Z D&D Project was decommissioned under the provisions of the 'Hanford Federal Facility Agreement and Consent Order' (the Tri-Party Agreement or TPA), the 'Resource Conservation and Recovery Act of 1976' (RCRA), and the 'Comprehensive Environmental Response, Compensation, and

  9. Deactivation of Building 7602

    International Nuclear Information System (INIS)

    The Department of Energy (DOE) has sponsored research and development programs in Building 7602 at Oak Ridge National Laboratory (ORNL) since 1984. This work focused on development of advanced technology for processing nuclear fuels. Building 7602 was used for engineering-scale tests using depleted and natural uranium to simulate the nuclear fuel. In April 1994 the DOE Office of Nuclear Energy (NE) sent supplemental FY 1994 guidance to ORNL stating that in FY 1995 and beyond, Building 7602 is considered surplus to NE programs and missions and shall be shut down (deactivated) and maintained in a radiologically and industrially safe condition with minimal surveillance and maintenance (S ampersand M). DOE-NE subsequently provided FY 1995 funding to support the deactivation activities. Deactivation of Building 7602 was initiated on October 1, 1994. The principal activity during the first quarter of FY 1995 was removal of process materials (chemicals and uranium) from the systems. The process systems were operated to achieve chemical solution concentrations needed for reuse or disposal of the solutions prior to removal of the materials from the systems. During this phase of deactivation the process materials processed and removed were: (1) Uranyl nitrate solution 30,178 L containing 4490 kg of uranium; (2) Nitric acid (neutralized) 9850 L containing less than 0.013 kg of uranium; (3) Organic solution 3346 L containing 265 kg of uranium; (4) Uranium oxide powder 95 kg; and (5) Miscellaneous chemicals. At the end of December 1994, the process systems and control systems were shut down and deactivated. Disposition of the process materials removed from the process systems in Building 7602 proved to be the most difficult part of the deactivation. An operational stand down and funding reductions at Y-12 prevented planned conversion of the uranyl nitrate solution to depleted uranium oxide powder. This led to disposal of the uranyl nitrate solution as waste

  10. Hazardous waste management in the Pacific basin

    Energy Technology Data Exchange (ETDEWEB)

    Cirillo, R.R.; Chiu, S.; Chun, K.C.; Conzelmann, G. [Argonne National Lab., IL (United States); Carpenter, R.A.; Indriyanto, S.H. [East-West Center, Honolulu, HI (United States)

    1994-11-01

    Hazardous waste control activities in Asia and the Pacific have been reviewed. The review includes China (mainland, Hong Kong, and Taiwan), Indonesia, Korea, Malaysia, Papua New Guinea, the Philippines, Singapore, and Thailand. It covers the sources of hazardous waste, the government structure for dealing with hazardous waste, and current hazardous waste control activities in each country. In addition, the hazardous waste program activities of US government agencies, US private-sector organizations, and international organizations are reviewed. The objective of these reviews is to provide a comprehensive picture of the current hazardous waste problems and the waste management approaches being used to address them so that new program activities can be designed more efficiently.

  11. Characterization plan for the waste holding basin (3513 impoundment)

    International Nuclear Information System (INIS)

    US Department of Energy (DOE) facilities are required to comply fully with all federal and state regulations. In response to this requirement, the Oak Ridge National Laboratory (ORNL) has established the remedial action program, to provide comprehensive management of areas where past research, development, and waste management activities have been conducted and have resulted in residual contamination of facilities or the environment. One of the objectives of this program is to define the extent of contamination at these sites. The intent is to document the known environmental characteristics of the sites and identify the additional actions, such as sampling, analytical measurements, and modeling, necessary to confirm contamination and the possible migration of contaminants from the sites. One of these sites is the waste holding basin (3513 impoundment). The 3513 impoundment is an unlined waste settling basin constructed in 1944 for collection of ORNL wastewater before its discharge into White Oak Creek. Operation of the facility ceased in 1976 when a new process waste treatment plant came into operation. Considerable site-specific environmental information has been developed over the years relative to the type and quantities of radionuclides and hazardous substances contained in the pond water and sediment. The concentrations and patterns of distribution for many of the radionuclides in the aquatic biota as well as for the terrestrial plants growing on the berm of the impoundment have been determined by DOE ecological studies. Recently, some data were collected that evaluate the extent of contaminant movement to the groundwater. Results from these studies are summarized in this report. Also included in this report is an outline of additional tasks needed to obtain the necessary information to model the transport and dose pathways of hazardous substances from the site

  12. Underground flux studies in waste basin of CIPC using natural and artificial tracers - v.1

    International Nuclear Information System (INIS)

    Underground flux studies in waste basin of CIPC is presented, with the description of the regions and the wells, the techniques with artificial tracers and the results and conclusion, based in field campaign realized till february/82. (author)

  13. PFP deactivation project management plan

    International Nuclear Information System (INIS)

    This document identifies the overall approach for deactivation of the Plutonium Finishing Plant (PFP) Complex, excluding the vaults, and includes a draft set of End Point Criteria for all buildings being deactivated

  14. PFP deactivation project management plan

    Energy Technology Data Exchange (ETDEWEB)

    Bogen, D.M.

    1997-07-28

    This document identifies the overall approach for deactivation of the Plutonium Finishing Plant (PFP) Complex, excluding the vaults, and includes a draft set of End Point Criteria for all buildings being deactivated.

  15. Technical basis for high-level waste repository land control requirements for Palo Duro Basin, Paradox Basin, and Richton Dome

    International Nuclear Information System (INIS)

    Three sites, the Palo Duro Basin in Texas, the Paradox Basin in Utah, and the Richton Dome in Mississippi, are being investigated by the US Department of Energy for high-level radioactive-waste disposal in mined, deep geologic repositories in salt. This report delineates the use of regulatory, engineering, and performance assessment information to establish the technical basis for controlled area requirements. Based on the size of the controlled area determined, plus that of the geologic repository operations area, recommendations of possible land control or ownership area requirements for each locale are provided. On a technical basis, the following minimum land control or ownership requirements are recommended, assuming repository operations area of 2240 ac (907 ha), or 3.5 mi2 (9.1 km2): Palo Duro Basin - 4060 ac (1643 ha), or 6.3 mi2 (16.4 km2); Paradox Basin - 4060 ac (1643 ha), or 6.3 mi2 (16.4 km2); and Richton Dome - 5000 ac (2024 ha), or 7.8 mi2 (20.2 km2). Of the factors used to determine the technically based recommendations, one was found to dominate each locale. For the Palo Duro and Paradox Basins, the dominant factor was the need to limit potential radionuclide release by ground-water flow to the accessible environment. For the Richton Dome, the dominant factor was the need to limit the potential effects of solution mining on dome and repository integrity

  16. Deactivations during the numerical processing

    Institute of Scientific and Technical Information of China (English)

    FENG HongBo; ZHANG Ye; TANG YiYuan; JIN Jing; DONG Feng; FENG ShiGang; ZHANG WuTian

    2007-01-01

    Deactivation has been encountered frequently in functional brain imaging researches. However,the deactivations during the numerical processing have not been reported yet. In this study,the functional magnetic resonance imaging (fMRI) was employed to investigate the pattern of the deactivation in the brain of 15 healthy subjects during the numerical addition task. Analyses revealed significant deactivations in several brain regions,including the posterior cingulate,precuneus,anterior cingulate and prefrontal cortex. Especially,we found notable deactivation in bilateral insula. Accounting for the cognitive functions of these regions participating in a combinated way,we discuss their contributions in sustaining the brain activity during conscious resting state,and indicate that the insula is an important area of gathering auditory information from the external world.

  17. The strategy and practice of radioactive waste management in the Pacific Basin

    International Nuclear Information System (INIS)

    Radioactive waste management is an integral part of the planning process for the nuclear industry in Pacific Basin countries. This paper reviews areas of common interest and cooperation, sources of waste and current inventories, production rates, and future plans. Each level of radioactive waste requires different methods for handling, storage, and disposal. Definitions may vary In detail from country to country, but generally high level wastes are defined as those deriving from spent fuel and from reprocessing of fuel. These wastes contain transuranic elements and fission products that are highly radioactive, heat-generating and long-lived. Intermediate level and low level wastes may include, respectively, material from fuel fabrication and power generation other than spent fuel, and those wastes produced by research institutions, hospitals, and in other non-power producing Industrial uses of radioisotopes. The energy requirements of most countries are likely to continue to grow, and the use of radioactive isotopes in medicine and other non-energy industrial sectors is also expanding. The Pacific Nuclear Council member states participating in the Waste Management Working Group, are predicting, therefore, that the volume of radioactive waste for disposal will continue to grow

  18. The kinetics of activation and deactivation in the process of water ozonising used for advanced oxidation of the dust waste from moulding sands

    Directory of Open Access Journals (Sweden)

    A. Baliński

    2009-01-01

    Full Text Available Adding coal dust and organic carriers of the lustrous carbon to bentonite-bonded moulding sands in amounts justified by thetechnological regime and the use of cores and protective coatings based on organic compounds create serious threats to the environment.During thermal destruction of the individual components of moulding and core sands, some toxic organic compounds are emitted. They formthe majority of the Hazardous Air Pollutants (HAPs, and include mainly compounds like benzene, toluene, xylene, naphtalene, hexane,acetaldehyde, acrolein, aniline, cresol and cumene, their polycyclic derivatives, phenol, formaldehyde, and other similar matters. In thusformed dust waste, the amount of which constitutes about 20% of all the waste from foundries using traditional moulding and core sands, there are still full-value materials which can undergo total recycling, providing the HAPs are partially or totally removed from them. The article discusses some problems of the advanced oxidation of selected toxic chemical compounds present in bentonite-bonded moulding sands due to the effect of high temperature. The results of the investigations of the kinetics of the process of maximum water saturation with ozone (acting as an oxidiser and of the kinetics of the natural process of ozone decomposition to diatomic oxygen were presented. It has been stated that the maximum time of water saturation with ozone using an OZOMATIC OSC-MODULAR 4HC ozone generator and a 1m3 capacity tank with water is 60 minutes. After 30 minute break in the ozonising process, the ozone concentration in water decreases by 40 to 50%. To obtain maximum ozone concentration in water during the next ozonising cycle, it is necessary to have the ozone-generating device running for the next 30 minutes. The stabilisation of ozone concentration in water takes place only after the third ozonising cycle, when it reaches nearly 80%of the maximum value obtained after the first process cycle

  19. DQO Summary Report for 324 and 327 Building Hot Cells D4 Project Waste Characterization

    Energy Technology Data Exchange (ETDEWEB)

    T.A. Lee

    2006-02-06

    This data quality objective (DQO) summary report provides the results of the DQO process conducted for waste characterization activities for the 324 and 327 Building hot cells decommission, deactivate, decontaminate, and demolish activities. This DQO summary report addresses the systems and processes related to the hot cells, air locks, vaults, tanks, piping, basins, air plenums, air ducts, filters, an adjacent elements that have high dose rates, high contamination levels, and/or suspect transuranic waste, which will require nonstandard D4 techniques.

  20. Geohydrology surrounding a potential high level nuclear waste repository in the Palo Duro Basin, Texas

    International Nuclear Information System (INIS)

    The Palo Duro Basin of the Texas Panhandle is being investigated as a potential high level nuclear waste repository site. As groundwater is the most likely mechanism for radionuclide movement, it is desirable to locate a repository in a hydrologic regime which is favorable for waste isolation and containment. The Palo Duro Basin consists of deep brine aquifers of low regional permeability underlying a thick Permian age evaporite section. The overlying Permian age evaporites are the Dockum and Ogallala fresh water aquifiers. Observed potentiometric data in the principal aquifers indicate a potential for downward flow from the surficial aquifiers to the deep brine aquifers. Groundwater movement in these deep aquifers is very slow. Modeling efforts indicate flow times of hundreds of thousands to over a million years for groundwater to reach the basin margins. Investigative methods have included drill-stem testing similar to oil field methodology, modified drill-stem testing with tools developed for low-permeability formations and long term production tests similar to conventional water well pumping tests. Testing has generally indicated permeability of .1-10 millidarcies in the water transmitting units

  1. Implementing RCRA during facility deactivation

    International Nuclear Information System (INIS)

    RCRA regulations require closure of permitted treatment, storage and disposal (TSD) facilities within 180 days after cessation of operations, and this may essentially necessitate decommissioning to complete closure. A more cost effective way to handle the facility would be to significantly reduce the risk to human health and the environment by taking it from its operational status to a passive, safe, inexpensive-to-maintain surveillance and maintenance condition (deactivation) prior to decommissioning. This paper presents an innovative approach to the cost effective deactivation of a large, complex chemical processing facility permitted under RCRA. The approach takes into account risks to the environment posed by this facility in comparison to risks posed by neighboring facilities at the site. The paper addresses the manner in which: 1) stakeholders and regulators were involved; 2) identifies a process by which the project proceeds and regulators and stakeholders were involved; 3) end points were developed so completion of deactivation was clearly identified at the beginning of the project, and 4) innovative practices were used to deactivate more quickly and cost effectively

  2. Heterogeneous Catalyst Deactivation and Regeneration: A Review

    OpenAIRE

    Morris D. Argyle; Calvin H. Bartholomew

    2015-01-01

    Deactivation of heterogeneous catalysts is a ubiquitous problem that causes loss of catalytic rate with time. This review on deactivation and regeneration of heterogeneous catalysts classifies deactivation by type (chemical, thermal, and mechanical) and by mechanism (poisoning, fouling, thermal degradation, vapor formation, vapor-solid and solid-solid reactions, and attrition/crushing). The key features and considerations for each of these deactivation types is reviewed in detail with referen...

  3. Problems of Chernobyl radioactive wastes management

    International Nuclear Information System (INIS)

    The aim of this work was analyze deactivation works for radio protection of population. Territories of objects subjected to deactivation had contamination level from 50 to 150 mk R/h. Burial place of deactivation wastes realized on territories of similar radio contamination level of soil with contamination level soil of wastes

  4. Solid waste disposal site selection with GIS and AHP methodology: a case study in Senirkent-Uluborlu (Isparta) Basin, Turkey.

    Science.gov (United States)

    Sener, Sehnaz; Sener, Erhan; Karagüzel, Remzi

    2011-02-01

    The appropriate site selection for waste disposal is one of the major problems in waste management. Also, many environmental, economical, and political considerations must be adhered to. In this study, landfill site selection is performed using the Geographic Information System (GIS), the Analytical Hierarchy Process (AHP), and the remote sensing methods for the Senirkent-Uluborlu Basin. The basin is located in the Eğirdir Lake catchment area, which is one of the most important fresh water in Turkey. So, waste management must be regulated in the basin. For this aim, ten different criteria (lithology, surface water, aquifer, groundwater depth, land use, lineaments, aspect, elevation, slope, and distance to roads) are examined in relation to landfill site selection. Each criterion was identified and weighted using AHP. Then, each criterion is mapped using the GIS technique, and a suitability map is prepared by overlay analyses. The results indicate that 96.3% of the area in the basin is unsuitable; 1.6%, moderately suitable; and 2.1%, most suitable. Finally, suitable regions in the basin are determined for solid waste landfill disposal and checked in the field. The selected and investigated regions are considered to be suitable for the landfill. PMID:20213053

  5. Controlled-deactivation cannabinergic ligands.

    Science.gov (United States)

    Sharma, Rishi; Nikas, Spyros P; Paronis, Carol A; Wood, Jodianne T; Halikhedkar, Aneetha; Guo, Jason Jianxin; Thakur, Ganesh A; Kulkarni, Shashank; Benchama, Othman; Raghav, Jimit Girish; Gifford, Roger S; Järbe, Torbjörn U C; Bergman, Jack; Makriyannis, Alexandros

    2013-12-27

    We report an approach for obtaining novel cannabinoid analogues with controllable deactivation and improved druggability. Our design involves the incorporation of a metabolically labile ester group at the 2'-position on a series of (-)-Δ(8)-THC analogues. We have sought to introduce benzylic substituents α to the ester group which affect the half-lives of deactivation through enzymatic activity while enhancing the affinities and efficacies of individual ligands for the CB1 and CB2 receptors. The 1'-(S)-methyl, 1'-gem-dimethyl, and 1'-cyclobutyl analogues exhibit remarkably high affinities for both CB receptors. The novel ligands are susceptible to enzymatic hydrolysis by plasma esterases in a controllable manner, while their metabolites are inactive at the CB receptors. In further in vitro and in vivo experiments key analogues were shown to be potent CB1 receptor agonists and to exhibit CB1-mediated hypothermic and analgesic effects.

  6. West Siberian basin hydrogeology - regional framework for contaminant migration from injected wastes

    Energy Technology Data Exchange (ETDEWEB)

    Foley, M.G.

    1994-05-01

    Nuclear fuel cycle activities of the former Soviet Union (FSU) have resulted in massive contamination of the environment in western Siberia. We are developing three-dimensional numerical models of the hydrogeology and potential contaminant migration in the West Siberian Basin. Our long-term goal at Pacific Northwest Laboratory is to help determine future environmental and human impacts given the releases that have occurred to date and the current waste management practices. In FY 1993, our objectives were to (1) refine and implement the hydrogeologic conceptual models of the regional hydrogeology of western Siberia developed in FY 1992 and develop the detailed, spatially registered digital geologic and hydrologic databases to test them, (2) calibrate the computer implementation of the conceptual models developed in FY 1992, and (3) develop general geologic and hydrologic information and preliminary hydrogeologic conceptual models relevant to the more detailed models of contaminated site hydrogeology. Calibration studies of the regional hydrogeologic computer model suggest that most precipitation entering the ground-water system moves in the near-surface part of the system and discharges to surface waters relatively near its point of infiltration. This means that wastes discharged to the surface and near-surface may not be isolated as well as previously thought, since the wastes may be carried to the surface by gradually rising ground waters.

  7. Heterogeneous Catalyst Deactivation and Regeneration: A Review

    Directory of Open Access Journals (Sweden)

    Morris D. Argyle

    2015-02-01

    Full Text Available Deactivation of heterogeneous catalysts is a ubiquitous problem that causes loss of catalytic rate with time. This review on deactivation and regeneration of heterogeneous catalysts classifies deactivation by type (chemical, thermal, and mechanical and by mechanism (poisoning, fouling, thermal degradation, vapor formation, vapor-solid and solid-solid reactions, and attrition/crushing. The key features and considerations for each of these deactivation types is reviewed in detail with reference to the latest literature reports in these areas. Two case studies on the deactivation mechanisms of catalysts used for cobalt Fischer-Tropsch and selective catalytic reduction are considered to provide additional depth in the topics of sintering, coking, poisoning, and fouling. Regeneration considerations and options are also briefly discussed for each deactivation mechanism.

  8. Catalyst Deactivation: Control Relevance of Model Assumptions

    OpenAIRE

    Bernt Lie; David M. Himmelblau

    2000-01-01

    Two principles for describing catalyst deactivation are discussed, one based on the deactivation mechanism, the other based on the activity and catalyst age distribution. When the model is based upon activity decay, it is common to use a mean activity developed from the steady-state residence time distribution. We compare control-relevant properties of such an approach with those of a model based upon the deactivation mechanism. Using a continuous stirred tank reactor as an example, we show t...

  9. Biological fate, transport, and ecotoxicity of toxic and hazardous waste in the Mississippi River Basin

    International Nuclear Information System (INIS)

    The objective of the cluster investigators is to develop a dynamic model for the evaluation of the biological fate, transport, and ecotoxicity from multiple chemical contamination of the Mississippi River Basin. To develop this environmental model, FY 93-94 most of cluster investigators focused on Devil's Swamp Site (DSS), a cypress swamp which lies just Northwest of Baton Rouge, Louisiana, adjacent to the Mississippi River. The DSS which includes a man-made lake has contaminated sediment, water and biota. The DSS receives flood water from the Mississippi River during high flow periods and the Baton Rouge Bayou drains through the DSS. The DSS receives toxic substances and hazardous waste from a wide variety of surrounding industrial operations including an abandoned hazardous waste disposal facility. In addition, some investigators studied Bayou Trepangnier. This research cluster will continue studying Devil Swamp. The large number of investigators in this cluster resulted from incorporating related research proposals based on reviewer recommendations. The specific aims of the cluster for the first year were to conduct a physical, chemical, ecological survey and baseline toxicological characterization of the DSS from existing databases maintained by State and federal agencies, field studies (assessment) of sediment, air, water and biota, and laboratory screening studios. This assessment will provide critical information and focus for the next two years in-depth studies of critical transport and fate processes, ecotoxicity, biomarkers of effect, and uptake, metabolism and distribution of toxicants. The primary significant outcome of the cluster researchers will be the development of an ecological risk assessment model combining biotic and physical/chemical variables for DSS with a projection of model reliability and accuracy for use at other typical Mississippi River Basin sites

  10. Geology and geohydrology of the east Texas Basin. Report on the progress of nuclear waste isolation feasibility studies (1979)

    Energy Technology Data Exchange (ETDEWEB)

    Kreitler, C.W.; Agagu, O.K.; Basciano, J.M.

    1980-01-01

    The program to investigate the suitability of salt domes in the east Texas Basin for long-term nuclear waste repositories addresses the stability of specific domes for potential repositories and evaluates generically the geologic and hydrogeologic stability of all the domes in the region. Analysis during the second year was highlighted by a historical characterization of East Texas Basin infilling, the development of a model to explain the growth history of the domes, the continued studies of the Quaternary in East Texas, and a better understanding of the near-dome and regional hydrology of the basin. Each advancement represents a part of the larger integrated program addressing the critical problems of geologic and hydrologic stabilities of salt domes in the East Texas Basin.

  11. Duration of activity of the microbial larvicide VectoLex CG (Bacillus sphaericus) in Illinois catch basins and waste tires.

    Science.gov (United States)

    Siegel, J P; Novak, R J

    1999-09-01

    The duration of activity of a formulation of Bacillus sphaericus, VectoLex CG, for control of Culex species was evaluated in 338 catch basins in Urbana, IL, and compared to Altosid in 346 catch basins in Champaign, IL. The activity of VectoLex in car and truck waste tires was evaluated in a tire dump located in Pembroke Township, IL. In catch basins, 1 g of VectoLex per catch basin gave the same control as one Altosid briquet. Both larvicides were effective against Culex sp. in catch basins for 1 month, and the duration of control with VectoLex lasted 44 days in one catch basin. VectoLex was considerably cheaper to apply than Altosid briquets, at 0.64 cents per catch basin compared to 90.75 cents, respectively. However, the Altosid briquets were judged to be easier to apply from a vehicle than VectoLex granules. VectoLex (22.6 kg) was used to treat approximately 6,000 car and truck tires; some of the tires were in direct sunlight whereas others were shaded. Aedes triseriatus was the dominant species in these tires. Tires treated with VectoLex contained significantly fewer mosquitoes than control tires, and even 65 days after application, control tires were 16.7 times more likely to contain larvae. We conclude that VectoLex was effective when used in Illinois catch basins and tire dumps, and emphasize that it is more appropriate to base tire treatment rates on the total number of tires present than on a kilogram per hectare basis.

  12. Recurrent Mass-wasting in Sørvestsnaget Basin, SW Barents Sea: A test of multiple hypotheses

    Science.gov (United States)

    Omosanya, K. O.; Harishidayat, D.; Lolita, M.; Johansen, S. E.; Abrahamson, P.

    2015-12-01

    Mass-wasting on the NE Atlantic margin is commonly attributed to Cenozoic glaciations. Using high-quality and high-resolution seismic dataset, this study investigates the types and mechanisms driving mass-wasting in the Sørvestsnaget Basin, Southwestern Barents. Seven mass-transport deposits (MTDs) ranging in age from Late Miocene to Holocene are interpreted on seismic profiles. The MTDs are vertically stacked from about 1900 ms TWTT to the present seabed. MTD 5 (area ca.1.22 x 103 km2, volume ca.3.4 x 103 km3) is the largest deposit in the study area and is composed largely of debrites and rafted blocks underlain by thin layers of hemipelagic sediments. Miocene and Early Pliocene MTDs in the basin demonstrate tendency for initial translation through canyons and channels. The youngest MTDs in the area are composed of glacigenic sediments remobilized by ice streams during Late Neogene and Quaternary glaciations. In the southern part of the study area, deep-water sediments fed through V-shaped canyons and channels are widespread signifying the Stappen High as the main sediment source area prior to the Late Pliocene. The prevalence of shallow marine successions in the northern part of the study area is linked to the southwesterly propagation of the shelf break from Miocene to Recent times. In this study, the shelf break trajectory is important for reconstructing paleo-sediment routes and dispersal pattern. The older non-glacial MTDs are separated farther from their paleo-shelf break. Mass-wasting is a recurrent process in the Sørvestsnaget Basin. Triggering mechanisms for slope failure in the basin may include increased pore pressure as a result of sea level fall and high sedimentation rate, over-steepened slope, glaciation, volcanism, and gas hydrate dissociation. Mass-wasting in the study area occurred through progressive, retrogressive and whole body or coherent downslope failures.

  13. Investigation of the concentration, distribution, and inventory of radionuclides in the sediment of Process Waste System Basin 3524

    International Nuclear Information System (INIS)

    Process Waste System Basin 3524 is used as a collection basin for process liquid waste from facilities at the Oak Ridge National Laboratory. This investigation was conducted to determine the radionuclide concentrations, distributions, and inventory of the sediments in this basin in preparation for future decontamination and decommissioning activities. Twenty-four sediment cores were extracted from the basin and 80 aliquots were analyzed for their radionuclide concentrations. The sediment is estimated to contain a total of 5.5 x 1012 Bq (150 Ci) of activity, 87% of which is contributed by two radionuclides, 137Cs (68%) and 90Sr (19%). The radionuclide content is estimated as follows: 137Cs, 3.77 x 1012 Bq (102 Ci); 90Sr, 1.07 x 1012 Bq (29 Ci); gross alpha, 4.06 x 1011 Bq (11 Ci); 241Am, 1.70 x 1011 Bq (4.6 Ci); 60Co, 8.32 x 1010 Bq (2.2 Ci); and 154Eu, 3.35 x 1010 Bq (0.9 Ci). 9 references, 8 figures, 7 tables

  14. PUREX Deactivation Health and Safety documentation

    International Nuclear Information System (INIS)

    The purpose of the PUREX Deactivation Project is to establish a passively safe and environmentally secure configuration of PUREX at the Hanford Site, and to preserve that configuration for a 10-year horizon. The 10-year horizon is used to predict future maintenance requirements and represents they typical time duration expended to define, authorize, and initiate the follow-on Decontamination and Decommissioning (D ampersand D) activities. This document was prepared to increase attention to worker safety issues during the deactivation project and, as such, identifies the documentation and programs associated with PUREX Deactivation Health and Safety

  15. PUREX Deactivation Health and Safety documentation

    Energy Technology Data Exchange (ETDEWEB)

    Dodd, E.N. III

    1995-01-01

    The purpose of the PUREX Deactivation Project is to establish a passively safe and environmentally secure configuration of PUREX at the Hanford Site, and to preserve that configuration for a 10-year horizon. The 10-year horizon is used to predict future maintenance requirements and represents they typical time duration expended to define, authorize, and initiate the follow-on Decontamination and Decommissioning (D&D) activities. This document was prepared to increase attention to worker safety issues during the deactivation project and, as such, identifies the documentation and programs associated with PUREX Deactivation Health and Safety.

  16. N Area Post-Deactivation ALARA Report

    International Nuclear Information System (INIS)

    This report provides information about a wide range of radiological work activities at the N Area Deactivation Project. The report is divided into sections that are based on specific N Area scopes of work. Each section contains specific information that was of significant radiological importance in completing N Area Deactivation work. The information presented in this report may be applicable and beneficial to similar projects throughout the U.S. Department of Energy (DOE) complex, and in commercial industry

  17. Nuclear fuel reprocessing deactivation plan for the Idaho Chemical Processing Plant, Revision 1

    International Nuclear Information System (INIS)

    The decision was announced on April 28, 1992 to cease all United States Department of Energy (DOE) reprocessing of nuclear fuels. This decision leads to the deactivation of all fuels dissolution, solvent extraction, krypton gas recovery operations, and product denitration at the Idaho Chemical Processing Plant (ICPP). The reprocessing facilities will be converted to a safe and stable shutdown condition awaiting future alternate uses or decontamination and decommissioning (D ampersand D). This ICPP Deactivation Plan includes the scope of work, schedule, costs, and associated staffing levels necessary to achieve a safe and orderly deactivation of reprocessing activities and the Waste Calcining Facility (WCF). Deactivation activities primarily involve shutdown of operating systems and buildings, fissile and hazardous material removal, and related activities. A minimum required level of continued surveillance and maintenance is planned for each facility/process system to ensure necessary environmental, health, and safety margins are maintained and to support ongoing operations for ICPP facilities that are not being deactivated. Management of the ICPP was transferred from Westinghouse Idaho Nuclear Company, Inc. (WINCO) to Lockheed Idaho Technologies Company (LITCO) on October 1, 1994 as part of the INEL consolidated contract. This revision of the deactivation plan (formerly the Nuclear Fuel Reprocessing Phaseout Plan for the ICPP) is being published during the consolidation of the INEL site-wide contract and the information presented here is current as of October 31, 1994. LITCO has adopted the existing plans for the deactivation of ICPP reprocessing facilities and the plans developed under WINCO are still being actively pursued, although the change in management may result in changes which have not yet been identified. Accordingly, the contents of this plan are subject to revision

  18. Deactivating a major nuclear fuels reprocessing facility

    International Nuclear Information System (INIS)

    This paper describes three key processes used in deactivating the Plutonium Uranium Extraction (PUREX) Facility, a large, complex nuclear reprocessing facility, 15 months ahead of schedule and $77 million under budget. The organization was reengineered to refine its business processes and more effectively organize around the deactivation work scope. Multi-disciplined work teams were formed to be self-sufficient and empowered to make decisions and perform work. A number of benefits were realized by reengineering. A comprehensive process to develop end points which clearly identified specific results and the post-project facility configuration was developed so all areas of a facility were addressed. Clear and specific end points allowed teams to focus on completing deactivation activities and helped ensure there were no unfulfilled end-of-project expectations. The RCRA regulations require closure of permitted facilities within 180 days after cessation of operations which may essentially necessitate decommissioning. A more cost effective approach was adopted which significantly reduced risk to human health and the environment by taking the facility to a passive, safe, inexpensive-to-maintain surveillance and maintenance condition (deactivation) prior to disposition. PUREX thus became the first large reprocessing facility with active TSD [treatment, storage, and disposal] units to be deactivated under the RCRA regulations

  19. Westinghouse Hanford Company recommended strategy for K Basin sludge disposition

    International Nuclear Information System (INIS)

    The objective of this document is to present the recommended strategy for removal of sludges from the K Basins. This document ties sludge removal activities to the plan for the K Basin spent nuclear fuel (SNF) described in WHC-EP-0830, Hanford Spent Nuclear Fuel Project Recommended Path Forward and is consistent with follow-on direction provided in February 1995. Solutions and processes for resolving sludge removal technical and management issues to meet accelerated K Basin deactivation objectives are described. The following outlines the major elements of the recommendation: (1) manage all sludges as SNF while in the K Basins; (2) once loose sludges are collected and removed from the facilities, manage them as radioactive or mixed waste consistent with the upcoming characterization results, the preferred sludge path forward alternative sends sludges to the Tank Waste Remediation System (TWRS) and/or the Hanford Solid Waste Disposal as appropriate; (3) continue to manage sludge within the fuel canisters at the time they are loaded into the multi-canister overpacks as SNF

  20. Data quality objectives summary report for 105-N Basin sediment disposition

    International Nuclear Information System (INIS)

    During stabilization of the 105-N Basin, sediments that have accumulated on basin surfaces will be vacuumed, collected in the North Cask Pit of the basin complex, and eventually removed. The environmental assessment for the deactivation of the N Reactor Facilities describes two potential disposition paths for the 105-N Basin sediment: transfer in slurry form to a double-shell tank if determined to be a transuranic waste, or disposal in solid form as a low-level waste. Interim storage of the sediments may be required if a transfer to the Tank Waste Remediation System cannot meet scheduled milestones. Selection of a particular alternative depends on the final characterization of the accumulated sediment, regulatory requirements, cost/benefit analyses, and 105-N Stabilization Project schedule requirements. The 105-N Basin Sediment Process is being conducted in two phases. The scope of the first phase includes identification of the sampling requirements, and the specific analyses required to support evaluation of the sediment disposition options. The objectives of the first phase of the 105-N Basin Sediment DQO Process include the following: identify the relevant acceptance criteria for each of the disposition options; and develop a sampling and analysis plan (SAP) sufficiently through to allow evaluation of sediment analysis results against each set of acceptance criteria

  1. Catalyst Deactivation: Control Relevance of Model Assumptions

    Directory of Open Access Journals (Sweden)

    Bernt Lie

    2000-10-01

    Full Text Available Two principles for describing catalyst deactivation are discussed, one based on the deactivation mechanism, the other based on the activity and catalyst age distribution. When the model is based upon activity decay, it is common to use a mean activity developed from the steady-state residence time distribution. We compare control-relevant properties of such an approach with those of a model based upon the deactivation mechanism. Using a continuous stirred tank reactor as an example, we show that the mechanistic approach and the population balance approach lead to identical models. However, common additional assumptions used for activity-based models lead to model properties that may deviate considerably from the correct one.

  2. On the CCN [de]activation nonlinearities

    CERN Document Server

    Arabas, Sylwester

    2016-01-01

    We take into consideration the evolution of particle size in a monodisperse aerosol population during activation and deactivation of cloud condensation nuclei (CCN). The phase portrait of the system derived through a weakly-nonlinear analysis reveals a saddle-node bifurcation and a cusp catastrophe. An analytical estimate of the activation timescale is derived through estimation of the time spent in the saddle-node bifurcation bottleneck. Numerical integration of the system portrays two types of activation/deactivation hystereses: one associated with the kinetic limitations on droplet growth when the system is far from equilibrium, and one occurring close to equilibrium and associated with the cusp catastrophe. The hysteretic behaviour close to equilibrium imposes stringent time-resolution constraints on numerical integration, particularly during deactivation.

  3. Deactivation, Decontamination and Decommissioning Project Summaries

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, David Shane; Webber, Frank Laverne

    2001-07-01

    This report is a compilation of summary descriptions of Deactivation, Decontamination and Decommissioning, and Surveillance and Maintenance projects planned for inactive facilities and sites at the INEEL from FY-2002 through FY-2010. Deactivations of contaminated facilities will produce safe and stable facilities requiring minimal surveillance and maintenance pending further decontamination and decommissioning. Decontamination and decommissioning actions remove contaminated facilities, thus eliminating long-term surveillance and maintenance. The projects are prioritized based on risk to DOE-ID, the public, and the environment, and the reduction of DOE-ID mortgage costs and liability at the INEEL.

  4. The Approach of Emotional Deactivation of Prejudice

    Science.gov (United States)

    Boucher, Jean-Nil

    2011-01-01

    The aim of the approach of emotional deactivation is to help students reduce the prejudice they may feel towards diverse social groups. Be those groups homosexuals, people living with a disability or immigrants, the victims of prejudice are invited to come into classrooms and to confront the preconceptions that students have in their respect.…

  5. Advances in Catalyst Deactivation and Regeneration

    OpenAIRE

    Calvin H. Bartholomew; Morris D. Argyle

    2015-01-01

    Catalyst deactivation, the loss over time of catalytic activity and/or selectivity, is a problem of great and continuing concern in the practice of industrial catalytic processes. Costs to industry for catalyst replacement and process shutdown total tens of billions of dollars per year. [...

  6. Advances in Catalyst Deactivation and Regeneration

    Directory of Open Access Journals (Sweden)

    Calvin H. Bartholomew

    2015-06-01

    Full Text Available Catalyst deactivation, the loss over time of catalytic activity and/or selectivity, is a problem of great and continuing concern in the practice of industrial catalytic processes. Costs to industry for catalyst replacement and process shutdown total tens of billions of dollars per year. [...

  7. Kinetic Analysis of Char Thermal Deactivation

    DEFF Research Database (Denmark)

    Zolin, Alfredo; Jensen, Anker; Dam-Johansen, Kim

    2001-01-01

    The thermal deactivation of several fuels was investigated by measuring the reactivity, of chars prepared in a thermogravimetric analyzer (TGA) apparatus at well-defined conditions in the temperature range 973-1673 K. Four coals, Blair Athol from Australia, Cerrejon from Colombia. Illinois no. 6...

  8. Deactivation efficiency of stabilized bactericidal emulsions.

    Science.gov (United States)

    Vyhnalkova, Renata; Eisenberg, Adi; van de Ven, Theo G M

    2011-09-20

    Biocide emulsions stabilized with various stabilizing agents were prepared and characterized, and their efficiency in bacteria deactivation was evaluated. A number of stabilizing agents were tested for their stabilizing effect on emulsions of thiocyanomethylthiobenzothiazole (TCMTB) biocide. Two agents, the most successful in stabilizing the biocide, were chosen for further studies: high molecular weight polyethyleneimine (PEI) and an amphiphilic block copolymer of poly(caprolactone)-b-poly(acrylic acid) (PCL(33)-b-PAA(33)). The emulsion droplet sizes varied between 325 and 500 nm. Deactivation of bacteria was studied by exposing E. coli ATCC 11229 bacteria dispersions to emulsions stabilized by positively charged PEI or negatively charged PCL-b-PAA micelles and by measuring their absorbance; E. coli do not grow with time in the presence of biocide emulsions. PEI molecules alone act as biocide and deactivate the bacteria. PCL-b-PAA micelles as stabilizing agent do not affect the growth of the E. coli ; bacteria are deactivated by TCMTB released from the emulsion droplets. The kinetics of emulsion dissolution studies revealed for both stabilizing agents a decrease in droplet size with time while the emulsions were subjected to dialysis. The biocide was released from the emulsions within ∼250 min; the droplet shells consist mostly of PEI or PCL-b-PAA insoluble complexes with the biocide, which do not dissolve during dialysis. SEM images confirm the presence of residual crumbled shells with holes after 24 h of dialysis. PMID:21823610

  9. 309 Building deactivation mission analysis report

    International Nuclear Information System (INIS)

    This report presents the results of the 309 Building (Plutonium Fuels Utilization Program) Deactivation Project mission analysis. Hanford systems engineering (SE) procedures call for a mission analysis. The mission analysis is an important first step in the SE process. The functions and requirements to successfully accomplish this mission, the selected alternatives and products will later be defined using the SE process

  10. Deactivation completed at historic Hanford Fuels Laboratory

    International Nuclear Information System (INIS)

    This report discusses deactivation work which was completed as of March 31, 1994 at the 308 Fuels Development Laboratory (FDL) at the Hanford Site near Richland, Washington. The decision to deactivate the structure, formerly known as the Plutonium Fabrication Pilot Plant (PFPP), was driven by a 1980s Department of Energy (DOE) decision that plutonium fuels should not be fabricated in areas near the Site's boundaries, as well as by changing facility structural requirements. Inventory transfer has been followed by the cleanout and stabilization of plutonium oxide (PuO2) and enriched uranium oxide (UO2) residues and powders in the facility's equipment and duct work. The Hanford Site, located in southeastern Washington state, was one of America's primary arsenals of nuclear defense production for nearly 50 years beginning in World War II. Approximately 53 metric tons of weapons grade plutonium, over half of the national supply and about one quarter of the world's supply, were produced at Hanford between 1944 and 1989. Today, many Site buildings are undergoing deactivation, a precursor phase to decontamination and decommissioning (D ampersand D). The primary difference between the two activities is that equipment and structural items are not removed or torn down in deactivation. However, utilities are disconnected, and special nuclear materials (SNM) as well as hazardous and pyrophoric substances are removed from structures undergoing this process

  11. DEACTIVATION AND DECOMMISSIONING PLANNING AND ANALYSIS WITH GEOGRAPHIC INFORMATION SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Bollinger, J; William Austin, W; Larry Koffman, L

    2007-09-17

    From the mid-1950's through the 1980's, the U.S. Department of Energy's Savannah River Site produced nuclear materials for the weapons stockpile, for medical and industrial applications, and for space exploration. Although SRS has a continuing defense-related mission, the overall site mission is now oriented toward environmental restoration and management of legacy chemical and nuclear waste. With the change in mission, SRS no longer has a need for much of the infrastructure developed to support the weapons program. This excess infrastructure, which includes over 1000 facilities, will be decommissioned and demolished over the forthcoming years. Dispositioning facilities for decommissioning and deactivation requires significant resources to determine hazards, structure type, and a rough-order-of-magnitude estimate for the decommissioning and demolition cost. Geographic information systems (GIS) technology was used to help manage the process of dispositioning infrastructure and for reporting the future status of impacted facilities.

  12. PUREX/UO3 Facilities deactivation lessons learned history

    Energy Technology Data Exchange (ETDEWEB)

    Gerber, M.S.

    1996-09-19

    objectives of the project in mind can guide decisions that reduce risks with minimal manipulation of physical materials, minimal waste generation, streamline regulations and safety requirements where possible, and separate the facility from ongoing entanglements with operating systems. Thus, the ``parked car`` state is achieved quickly and directly. The PUREX Deactivation Lessons Learned History was first issued in January 1995. Since then, several key changes have occurred in the project, making it advisable to revise and update the document. This document is organized with the significant lessons learned captured at the end of each section, and then recounted in Section 11.0, ``Lessons Consolidated.`` It is hoped and believed that the lessons learned on the PUREX Deactivation Project will have value to other facilities both inside and outside the DOE complex.

  13. Assessment of tectonic hazards to waste storage in interior-basin salt domes

    International Nuclear Information System (INIS)

    Salt domes in the northern Gulf of Mexico may make ideal sites for storage of radioactive waste because the area is tectonically quiet. The stability of such salt domes and the tectonic activity are discussed

  14. The task dependent interaction of the deactivation regions

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ye; FENG ShiGang; FENG HongBo; DONG Feng; TANG YiYuan

    2008-01-01

    Although deactivation has been found frequently in former functional brain imaging researches, only recently has it become a focus of systematic study because of its not well understood physiological mechanism. However, most of the researches concentrated on the brain areas that would present de-activation, and, to our knowledge, the deactivation connectivity between these brain areas during the cognitive tasks has rarely been reported in literature. In this work, using the functional connectivity method WlCA (within-condition interregional covariance analysis), we analyzed the deactivations in two different cognitive tasks-symbol orientation and number comparison. The results revealed de-activations in the posterior cingulate, precuneus, anterior cingulate and prefrontal cortex in both tasks. However, the interaction between the deactivated regions shows many differences. Our result further indicates that the potential implication of special deactivation connectivity may be related to the dif-ferent task or attention resource. Further research is needed to clarify the exact reason.

  15. The effects of irrigation waste-water disposal in a former discharge zone of the Murray Basin, Australia

    Science.gov (United States)

    Chambers, L. A.; Williams, B. G.; Barnes, C. J.; Wasson, R. J.

    1992-08-01

    In the Murray Basin in southeastern Australia, saline waste irrigation waters are often discharged to natural depressions and saline lakes as a salinity and land management strategy. At the Noora disposal basin in South Australia the waste irrigation water ( EC = 17-19 dS m-1) has formed a lens in the top of the highly saline (50-80 dS m -1) regional groundwater (Parilla Sands) aquifer. Using salinity and environmental isotopes of water (deuterium and oxygen-18) the lens has been shown to extend about 500 m in a northwesterly direction from the disposal pond. The major effects of this lens have been: (1) to cause upwards displacement of the regional ground water over an area of about 285 km 2, implying increased evaporation from areas surrounding the lens; (2) to reduce evaporation of regional ground water from the central low-lying area. Electromagnetic induction techniques for detecting preferred flowpaths away from the basin were rendered ineffective in this environment because of lithologic variations within the dune system. However, examination of bore-logs and groundwater gradients indicated that there was little evidence of stratigraphic control of mound development. Salinity in the Parilla Sands aquifer was closely related to the depth of the water table from the soil surface. Shallow (2-4 m) water tables were affected by recharge and evaporation to a much greater extent than ground water located below the higher dunes. There was, however, an almost instantaneous pressure response throughout the whole groundwater system to changes induced in the low-lying areas. Analyses of piezometric data showed that there was a seasonal variation imposed on the groundwater mound development. Corrected mean annual water-table increments and estimates of the mound volume and area were derived from a Theis response curve of the water table rise associated with the mound alone. Calculations using fitted parameters from the Theis analyses also suggested high transmissivity

  16. Laboratory Evaluation of Underwater Grouting of CPP-603 Basins

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, V.J.; Pao, J.H.; Demmer, R.L.; Tripp, J.L.

    2002-01-17

    A project is underway to deactivate a Fuel Storage Basin. The project specifies the requirements and identifies the tasks that will be performed for deactivation of the CPP- 603 building at the Idaho Nuclear Technology and Engineering Center of the Idaho National Engineering and Environmental Laboratory. The Fuel Receiving and Storage Building (CPP- 603) was originally used to receive and store spent nuclear fuel from various facilities. The area to undergo deactivation includes the three spent nuclear fuel storage basins and a transfer canal (1.5 million gallons of water storage). Deactivation operations at the task site include management of the hot storage boxes and generic fuel objects, removal of the fuel storage racks, basin sludge, water evaporation and basin grouting, and interior equipment, tanks, and associated components. This includes a study to develop a grout formulation and placement process for this deactivation project. Water will be allowed to passively evaporate to r educe the spread of contamination from the walls of the basin. The basins will be filled with grout, underwater, as the water evaporates to maintain the basin water at a safe level. The objective of the deactivation project is to eliminate potential exposure to hazardous and radioactive materials and eliminate potential safety hazards associated with the CPP-603 building.

  17. Laboratory Evaluation of Underwater Grouting of CPP-603 Basins

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Virgil James; Pao, Jenn Hai; Demmer, Ricky Lynn; Tripp, Julia Lynn

    2002-02-01

    A project is underway to deactivate a Fuel Storage Basin. The project specifies the requirements and identifies the tasks that will be performed for deactivation of the CPP- 603 building at the Idaho Nuclear Technology and Engineering Center of the Idaho National Engineering and Environmental Laboratory. The Fuel Receiving and Storage Building (CPP- 603) was originally used to receive and store spent nuclear fuel from various facilities. The area to undergo deactivation includes the three spent nuclear fuel storage basins and a transfer canal (1.5 million gallons of water storage). Deactivation operations at the task site include management of the hot storage boxes and generic fuel objects, removal of the fuel storage racks, basin sludge, water evaporation and basin grouting, and interior equipment, tanks, and associated components. This includes a study to develop a grout formulation and placement process for this deactivation project. Water will be allowed to passively evaporate to reduce the spread of contamination from the walls of the basin. The basins will be filled with grout, underwater, as the water evaporates to maintain the basin water at a safe level. The objective of the deactivation project is to eliminate potential exposure to hazardous and radioactive materials and eliminate potential safety hazards associated with the CPP-603 building.

  18. Radiometric dating of Ochoan (Permian) evaporites, WIPP [Waste Isolation Pilot Plant] site, Delaware Basin, New Mexico, USA

    International Nuclear Information System (INIS)

    We have attempted radiometric dating of halide-sulfate salts and clay minerals from the Delaware Basin, New Mexico, USA, as part of geochemical study of the stability of the evaporite sequence at the WIPP (Waste Isolation Pilot Plant - a US DOE facilty) site. We undertook this dating to determine: (1) primary age of evaporite genesis or time(s) of recrystallization; (2) if previously undated evaporite minerals (leonite, polyhalite, kieserite) give useful data; and (3) if the detrital clay minerals have been radiometrically reset at any time following their incorporation into the evaporite medium. We have shown earlier that polyhalites can indeed be successfully dated by the K-Ar method, and once corrections are applied for admixed halide minerals, dates of 210-230 Ma for the Delaware Basin are obtained. Rb-Sr isochrons from early stage sylvites-polyhalites- anhydrites yield 220 +- 10 Ma, even when some sylvites yield lower K-Ar dates due to loss of *40-Ar. K-Ar dates on leonites and kieserities are also low due to *40-Ar loss, but their Rb-Sr dates are higher. Detrital clay minerals from the Delaware Basin collectively yield a highly scattered isochron (390 +- 77 Ma), but samples from a local area, such as the WIPP Site, give a much better age of 428 +- 7 Ma. These dates show that the interaction between the clay minerals and the evaporitic brines was insufficient to reset the clay minerals Rb-Sr systematics. In a related study, we note that a dike emplaced into the evaporite at 34 Ma had only very limited effect on the intruded rocks; contact phenomena were all within 2 m of the dike. All of our geochemical (radio-metric and trace element) studies of the WIPP site argue for preservation of the isotopic and chemical integrity of the major minerals for the past 200 Ma

  19. Data quality objectives summary report for the 107-N Basin recirculation building liquid/sediment

    International Nuclear Information System (INIS)

    The scope of the 107-N Basin Recirculation Facility Liquid/Sediment Data Quality Objectives (DQO) exclusively involves the determination of sampling and analytical requirements during the deactivation period. The sampling requirements are primarily directed at sample characterization for comparison to decontamination and decommissioning (D and D) endpoint acceptance criteria in preparation for turnover of the facilities (listed below) to D and D organization. If determined to be waste, the sample characterization is also used for comparison with the waste acceptance criteria (WAC) of the receiving facilities for selection of the appropriate disposition. Additionally, the data generated from the characterization will be used to support the selection of available disposition options. The primary media within the scope of this DQO includes the following: Accumulated liquids and sediment contained in tanks, vessels, pump wells, sumps, associated piping, and valve pit floors; and Limited solid debris (anticipated to be discovered). Although the title of this report refers only to the 107-N Basin Recirculation Building, this DQO encompasses the following four 100-N Buildings/areas: 1310-N valve pit area inside the Radioactive Chemical Waste Treatment Pump House (silo); 1314-N Waste Pump (Overflow) Tank at the Liquid Waste Disposal Station; 105-N Lift Station pump well and valve pit areas inside the 105-N Reactor Building; and 107-N Basin Recirculation Building

  20. Disposal alternatives and recommendations for waste salt management for repository excavation in the Palo Duro Basin, Texas

    International Nuclear Information System (INIS)

    This report documents an evaluation of five alternatives for the disposal of waste salt that would be generated by the construction of a repository for radioactive waste in underground salt deposits at either of two sites in the Palo Duro Basin, Texas. The alternatives include commercial disposal, offsite deep-well injection, disposal in abandoned mines, ocean disposal, and land surface disposal on or off the site. For each alternative a reference case was rated - positive, neutral, or negative - in terms of environmental and dependability factors developed specifically for Texas sites. The factors constituting the environmental checklist relate to water quality impact, water- and land-use conflicts, ecological compatibility, conformity with air quality standards, and aesthetic impact. Factors on the dependability check-list relate to public acceptance, the adequacy of site characterization, permit and licensing requirements, technological requirements, and operational availability. A comparison of the ratings yielded the following viable alternatives, in order of preference: (1) land surface disposal, specifically disposal on tailings piles associated with abandoned potash mines; (2) disposal in abandoned mines, specifically potash mines; and (3) commercial disposal. Approaches to the further study of these three salt management techniques are recommended

  1. Production of biochar out of organic urban waste to amend salt affected soils in the basin of Mexico

    Science.gov (United States)

    Chavez Garcia, Elizabeth; Siebe, Christina

    2016-04-01

    Biochar is widely recognized as an efficient tool for carbon sequestration and soil fertility. The understanding of its chemical and physical properties, strongly related to the biomass and production conditions, is central to identify the most suitable application of biochar. On the other hand, salt affected soils reduce the value and productivity of extensive areas worldwide. One feasible option to recover them is to add organic amendments, which improve water holding capacity and increase sorption sites for cations as sodium. The former lake Texcoco in the basin of Mexico has been a key area for the control of surface run-off and air quality of Mexico City. However, the high concentrations of soluble salts in their soils do not allow the development of a vegetation cover that protects the soil from wind erosion, being the latter the main cause of poor air quality in the metropolitan area during the dry season. On the other hand, the population of the city produces daily 2000 t of organic urban wastes, which are currently composted. Thus, we tested if either compost or biochar made out of urban organic waste can improve the salt affected soils of former lake Texcoco to grow grass and avoid wind erosion. We examined the physico-chemical properties of biochar produced from urban organic waste under pyrolysis conditions. We also set up a field experiment to evaluate the addition of these amendments into the saline soils of Texcoco. Our preliminary analyses show biochar yield was ca. 40%, it was mainly alkaline (pH: 8-10), with a moderate salt content (electrical conductivity: 0.5-3 mS/cm). We show also results of the initial phase of the field experiment in which we monitor the electrical conductivity, pH, water content, water tension and soil GHG fluxes on small plots amended with either biochar or compost in three different doses.

  2. Occurrence of acidic pharmaceuticals and personal care products in Turia River Basin: from waste to drinking water.

    Science.gov (United States)

    Carmona, Eric; Andreu, Vicente; Picó, Yolanda

    2014-06-15

    The occurrence of 21 acidic pharmaceuticals, including illicit drugs, and personal care products (PPCPs) in waste, surface and drinking water and in sediments of the Turia River Basin (Valencia, Spain) was studied. A liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for the determination of these PPCPs with electrospray (ESI) in negative ionization (NI) mode. Ammonium fluoride in the mobile phase improved ionization efficiency by an average increase in peak area of 5 compared to ammonium formate or formic acid. All studied compounds were detected and their concentration was waste water>surface water>drinking water. PPCPs were in waste water treatment plants (WWTPs) influents up to 7.26μgL(-1), dominated by ibuprofen, naproxen and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCOOH). WWTPs were highly effective in removing most of them, with an average removal rate of >90%. PPCPs were still detected in effluents in the 6.72-940ngL(-1) range, with the THCOOH, triclocarban, gemfibrozil and diclofenac as most prevalent. Similarly, diclofenac, gemfibrozil, ibuprofen, naproxen and propylparaben were detected quite frequently from the low ngL(-1) range to 7μgL(-1) in the surface waters of Turia River. Ibuprofen, methylparaben, salicylic acid and tetrahydrocannabinol (THC) were at concentrations up to 0.85ngg(-1) d.w. in sediments. The discharge of WWTP as well as of non-treated waters to this river is a likely explanation for the significant amount of PPCPs detected in surface waters and sediments. Mineral and tap waters also presented significant amounts (approx. 100ngL(-1)) of ibuprofen, naproxen, propylparaben and butylparaben. The occurrence at trace levels of several PPCPs in drinking water raises concerns about possible implications for human health. PMID:24686145

  3. Optimization of sorption technology processing of liquid radioactive waste of low and middle activity level

    International Nuclear Information System (INIS)

    A substantial amount of liquid radioactive wastes (LRW) is formed during the regeneration of irradiated nuclear fuel (INF). Liquid wastes of low activity level (LAL) include: wash water and leakages; water for hydrotransport; water in storage basins; water from special laundries and disinfestation posts; and waste deactivation solutions. The radioactivity of these LRWs is equal to 1 x 10-7 1 x 10-5 Ci/l. Depending on the sources of the water supply for processing of INF, as well as technology and time (seasons) of processing, productivity and other factors, variations exist in the chemical and radiochemical compositions of LAL. This article discusses various processing treatments for low and intermediate level radioactive wastes

  4. A study of paint sludge deactivation by pyrolysis reactions

    Directory of Open Access Journals (Sweden)

    L.A.R. Muniz

    2003-03-01

    Full Text Available The production of large quantities of paint sludge is a serious environmental problem. This work evaluates the use of pyrolysis reaction as a process for deactivating paint sludge that generates a combustible gas phase, a solvent liquid phase and an inert solid phase. These wastes were classified into three types: water-based solvent (latex resin and solvents based on their resins (alkyd and polyurethane. An electrically heated stainless steel batch reactor with a capacity of 579 mL and a maximum pressure of 30 atm was used. Following the reactor, a flash separator, which was operated at atmospheric pressure, partially condensed and separated liquid and gas products. Pressure and temperature were monitored on-line by a control and data acquisition system, which adjusted the heating power supplied to the pyrolysis reactor. Reactions followed an experimental design with two factors (reaction time and temperature and three levels (10, 50 and 90 minutes; 450, 550 and 650°C. The response variables were liquid and solid masses and net heat of combustion. The optimal operational range for the pyrolysis process was obtained for each response variable. A significant reduction in total mass of solid waste was obtained.

  5. Planning for closure and deactivation of the EBR-II complex

    International Nuclear Information System (INIS)

    In January 1994, DOE terminated the Integral Fast Reactor (IFR) Program. Argonne National Laboratory-West (ANL-W) prepared a detailed plan to put Experimental Breeder Reactor-II (EBR-II) in a safe condition, including removal of irradiated fueled subassemblies from the plant, transfer of subassemblies, and removal and stabilization of primary and secondary sodium liquid heat transfer metal. The goal of deactivation is to stabilize the EBR-II complex until decontamination and decommissioning (D ampersand D) is implemented, thereby minimizing maintenance and surveillance. Deactivation of a sodium cooled reactor presents unique concerns. Residual sodium in the primary and secondary systems must be either reacted or inerted to preclude concerns with explosive sodium-air reactions. Also, residual sodium on components will effectively solder these items in place, making removal unfeasible. Several special cases reside in the primary system, including primary cold traps, a cesium trap, a cover gas condenser, and systems containing sodium-potassium alloy. The sodium or sodium-potassium alloy in these components must be reacted in place or the components removed. The Sodium Components Maintenance Shop at ANL-W provides the capability for washing primary components, removing residual quantities of sodium while providing some decontamination capacity. Considerations need to be given to component removal necessary for providing access to primary tank internals for D ampersand D activities, removal of hazardous materials, and removal of stored energy sources. ANL-W's plan for the deactivation of EBR-II addresses these issues, providing for an industrially and radiologically safe complex, requiring minimal surveillance during the interim period between deactivation and D ampersand D. Throughout the deactivation and closure of the EBR-II complex, federal environmental concerns will be addressed, including obtaining the proper permits for facility condition and waste processing

  6. Regional geological assessment of the Devonian-Mississippian shale sequence of the Appalachian, Illinois, and Michigan basins relative to potential storage/disposal of radioactive wastes

    International Nuclear Information System (INIS)

    The thick and regionally extensive sequence of shales and associated clastic sedimentary rocks of Late Devonian and Early Mississippian age has been considered among the nonsalt geologies for deep subsurface containment of high-level radioactive wastes. This report examines some of the regional and basin-specific characteristics of the black and associated nonblack shales of this sequence within the Appalachian, Illinois, and Michigan basins of the north-central and eastern United States. Principal areas where the thickness and depth of this shale sequence are sufficient to warrant further evaluation are identified, but no attempt is made to identify specific storage/disposal sites. Also identified are other areas with less promise for further study because of known potential conflicts such as geologic-hydrologic factors, competing subsurface priorities involving mineral resources and groundwater, or other parameters. Data have been compiled for each basin in an effort to indicate thickness, distribution, and depth relationships for the entire shale sequence as well as individual shale units in the sequence. Included as parts of this geologic assessment are isopach, depth information, structure contour, tectonic elements, and energy-resource maps covering the three basins. Summary evaluations are given for each basin as well as an overall general evaluation of the waste storage/disposal potential of the Devonian-Mississippian shale sequence,including recommendations for future studies to more fully characterize the shale sequence for that purpose. Based on data compiled in this cursory investigation, certain rock units have reasonable promise for radioactive waste storage/disposal and do warrant additional study

  7. Regional geological assessment of the Devonian-Mississippian shale sequence of the Appalachian, Illinois, and Michigan basins relative to potential storage/disposal of radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    Lomenick, T.F.; Gonzales, S.; Johnson, K.S.; Byerly, D.

    1983-01-01

    The thick and regionally extensive sequence of shales and associated clastic sedimentary rocks of Late Devonian and Early Mississippian age has been considered among the nonsalt geologies for deep subsurface containment of high-level radioactive wastes. This report examines some of the regional and basin-specific characteristics of the black and associated nonblack shales of this sequence within the Appalachian, Illinois, and Michigan basins of the north-central and eastern United States. Principal areas where the thickness and depth of this shale sequence are sufficient to warrant further evaluation are identified, but no attempt is made to identify specific storage/disposal sites. Also identified are other areas with less promise for further study because of known potential conflicts such as geologic-hydrologic factors, competing subsurface priorities involving mineral resources and groundwater, or other parameters. Data have been compiled for each basin in an effort to indicate thickness, distribution, and depth relationships for the entire shale sequence as well as individual shale units in the sequence. Included as parts of this geologic assessment are isopach, depth information, structure contour, tectonic elements, and energy-resource maps covering the three basins. Summary evaluations are given for each basin as well as an overall general evaluation of the waste storage/disposal potential of the Devonian-Mississippian shale sequence,including recommendations for future studies to more fully characterize the shale sequence for that purpose. Based on data compiled in this cursory investigation, certain rock units have reasonable promise for radioactive waste storage/disposal and do warrant additional study.

  8. PUREX/UO{sub 3} deactivation project management plan

    Energy Technology Data Exchange (ETDEWEB)

    Washenfelder, D.J.

    1993-12-01

    From 1955 through 1990, the Plutonium-Uranium Extraction Plant (PUREX) provided the United States Department of Energy Hanford Site with nuclear fuel reprocessing capability. It operated in sequence with the Uranium Trioxide (UO{sub 3}) Plant, which converted the PUREX liquid uranium nitrate product to solid UO{sub 3} powder. Final UO{sub 3} Plant operation ended in 1993. In December 1992, planning was initiated for the deactivation of PUREX and UO{sub 3} Plant. The objective of deactivation planning was to identify the activities needed to establish a passively safe, environmentally secure configuration at both plants, and ensure that the configuration could be retained during the post-deactivation period. The PUREX/UO{sub 3} Deactivation Project management plan represents completion of the planning efforts. It presents the deactivation approach to be used for the two plants, and the supporting technical, cost, and schedule baselines. Deactivation activities concentrate on removal, reduction, and stabilization of the radioactive and chemical materials remaining at the plants, and the shutdown of the utilities and effluents. When deactivation is completed, the two plants will be left unoccupied and locked, pending eventual decontamination and decommissioning. Deactivation is expected to cost $233.8 million, require 5 years to complete, and yield $36 million in annual surveillance and maintenance cost savings.

  9. PUREX/UO3 deactivation project management plan

    International Nuclear Information System (INIS)

    From 1955 through 1990, the Plutonium-Uranium Extraction Plant (PUREX) provided the United States Department of Energy Hanford Site with nuclear fuel reprocessing capability. It operated in sequence with the Uranium Trioxide (UO3) Plant, which converted the PUREX liquid uranium nitrate product to solid UO3 powder. Final UO3 Plant operation ended in 1993. In December 1992, planning was initiated for the deactivation of PUREX and UO3 Plant. The objective of deactivation planning was to identify the activities needed to establish a passively safe, environmentally secure configuration at both plants, and ensure that the configuration could be retained during the post-deactivation period. The PUREX/UO3 Deactivation Project management plan represents completion of the planning efforts. It presents the deactivation approach to be used for the two plants, and the supporting technical, cost, and schedule baselines. Deactivation activities concentrate on removal, reduction, and stabilization of the radioactive and chemical materials remaining at the plants, and the shutdown of the utilities and effluents. When deactivation is completed, the two plants will be left unoccupied and locked, pending eventual decontamination and decommissioning. Deactivation is expected to cost $233.8 million, require 5 years to complete, and yield $36 million in annual surveillance and maintenance cost savings

  10. DEACTIVATION AND DECOMMISSIONING (D AND D) TECHNOLOGY INTEGRATION

    Energy Technology Data Exchange (ETDEWEB)

    M.A. Ebadian, Ph.D.

    1999-01-01

    As part of the ongoing task of making Deactivation and Decommissioning (D&D) operations more efficient, this subtask has addressed the need to integrate existing characterization technologies with decontamination technologies in order to provide real-time data on the progress of contamination removal. Specifically, technologies associated with concrete decontamination and/or removal have been examined with the goal of integrating existing technologies and commercializing the resulting hybrid. The Department of Energy (DOE) has estimated that 23 million cubic meters of concrete will require disposition as 1200 buildings undergo the D&D process. All concrete removal to be performed will also necessitate extensive use of characterization techniques. The in-process characterization presents the most potential for improvement and cost-savings as compared to other types. Current methods for in-process characterization usually require cessation of work to allow for radiation surveys to assess the rate of decontamination. Combining together decontamination and characterization technologies would allow for in-process evaluation of decontamination efforts. Since the present methods do not use in-process evaluations for the progress of decontamination, they may allow for ''overremoval'' of materials (removal of contaminated along with non-contaminated materials). Overremoval increases the volume of waste and therefore the costs associated with disposal. Integrating technologies would facilitate the removal of only contaminated concrete and reduce the total volume of radioactive waste, which would be disposed of. This would eventually ensure better productivity and time savings. This project presents a general procedure to integrate the above-mentioned technologies in the form of the Technology Integration Module (TIM) along with combination lists of commercially available decontamination and characterization technologies. The scope of the project has also

  11. DEACTIVATION AND DECOMMISSIONING (D AND D) TECHNOLOGY INTEGRATION

    International Nuclear Information System (INIS)

    As part of the ongoing task of making Deactivation and Decommissioning (D and D) operations more efficient, this subtask has addressed the need to integrate existing characterization technologies with decontamination technologies in order to provide real-time data on the progress of contamination removal. Specifically, technologies associated with concrete decontamination and/or removal have been examined with the goal of integrating existing technologies and commercializing the resulting hybrid. The Department of Energy (DOE) has estimated that 23 million cubic meters of concrete will require disposition as 1200 buildings undergo the D and D process. All concrete removal to be performed will also necessitate extensive use of characterization techniques. The in-process characterization presents the most potential for improvement and cost-savings as compared to other types. Current methods for in-process characterization usually require cessation of work to allow for radiation surveys to assess the rate of decontamination. Combining together decontamination and characterization technologies would allow for in-process evaluation of decontamination efforts. Since the present methods do not use in-process evaluations for the progress of decontamination, they may allow for ''overremoval'' of materials (removal of contaminated along with non-contaminated materials). Overremoval increases the volume of waste and therefore the costs associated with disposal. Integrating technologies would facilitate the removal of only contaminated concrete and reduce the total volume of radioactive waste, which would be disposed of. This would eventually ensure better productivity and time savings. This project presents a general procedure to integrate the above-mentioned technologies in the form of the Technology Integration Module (TIM) along with combination lists of commercially available decontamination and characterization technologies. The scope of the project has also been

  12. Fitness-driven deactivation in network evolution

    International Nuclear Information System (INIS)

    Individual nodes in evolving real-world networks typically experience growth and decay—that is, the popularity and influence of individuals peaks and then fades. In this paper, we study this phenomenon via an intrinsic nodal fitness function and an intuitive ageing mechanism. Each node of the network is endowed with a fitness which represents its activity. All the nodes have two discrete stages: active and inactive. The evolution of the network combines the addition of new active nodes randomly connected to existing active ones and the deactivation of old active nodes with a possibility inversely proportional to their fitnesses. We obtain a structured exponential network when the fitness distribution of the individuals is homogeneous and a structured scale-free network with heterogeneous fitness distributions. Furthermore, we recover two universal scaling laws of the clustering coefficient for both cases, C(k) ∼ k−1 and C ∼ n−1, where k and n refer to the node degree and the number of active individuals, respectively. These results offer a new simple description of the growth and ageing of networks where intrinsic features of individual nodes drive their popularity, and hence degree

  13. Fitness-driven deactivation in network evolution

    CERN Document Server

    Xu, Xin-Jian; Small, Michael; Fu, Xin-Chu

    2010-01-01

    Individual nodes in evolving real-world networks typically experience growth and decay --- that is, the popularity and influence of individuals peaks and then fades. In this paper, we study this phenomenon via an intrinsic nodal fitness function and an intuitive aging mechanism. Each node of the network is endowed with a fitness which represents its activity. All the nodes have two discrete stages: active and inactive. The evolution of the network combines the addition of new active nodes randomly connected to existing active ones and the deactivation of old active nodes with possibility inversely proportional to their fitnesses. We obtain a structured exponential network when the fitness distribution of the individuals is homogeneous and a structured scale-free network with heterogeneous fitness distributions. Furthermore, we recover two universal scaling laws of the clustering coefficient for both cases, $C(k) \\sim k^{-1}$ and $C \\sim n^{-1}$, where $k$ and $n$ refer to the node degree and the number of act...

  14. 1997 project of the year, PUREX deactivation project

    International Nuclear Information System (INIS)

    At the end of 1992, the PUREX and UO3 plants were deemed no longer necessary for the defense needs of the United States. Although no longer necessary, they were very costly to maintain in their post-operation state. The DOE embarked on a deactivation strategy for these plants to reduce the costs of providing continuous surveillance of the facilities and their hazards. Deactivation of the PUREX and UO3 plants was estimated to take 5 years and cost $222.5 million and result in an annual surveillance and maintenance cost of $2 million. Deactivation of the PUREX/UO3 plants officially began on October 1, 1993. The deactivation was 15 months ahead of the original schedule and $75 million under the original cost estimate. The annual cost of surveillance and maintenance of the plants was reduced to less than $1 million

  15. Co-pyrolsis of polyethylene waste with the Campos basin heavy oil; Co-pirolise de residuos de polietileno com gasoleo pesado da Bacia de Campos

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, Debora da S.; Marques, Monica R. da C. [Laboratorio de Tecnologia Ambiental, UERJ, Rio de Janeiro, RJ (Brazil)], e-mail: monica@pesquisador.cnpq.br

    2011-07-01

    In this study, four mixtures of LDPE post consumer with heavy gas from the Campos Basin, in different proportions, were subjected to pyrolysis in an inert atmosphere at 550 deg C. The pyrolytic liquids were characterized by gas chromatography coupled to mass spectrometry (GC/MS). Pyrolysis of pure diesel supplied large amounts of waste oil and only 4% in the range of diesel. On the other hand, the pyrolysis of LDPE mixture of diesel (at the ratio 1/0,5 m/m) provided 20% of light hydrocarbons with high production of pyrolytic oil (96%). The formation of high levels of paraffins and olefins in the range of diesel oil during the co-pyrolysis suggests a promising technology for recycling of plastic waste. (author)

  16. Biomonitoring a human population inhabiting nearby a deactivated uranium mine

    International Nuclear Information System (INIS)

    Highlights: ► Human population environmentally exposed to uranium mining wastes. ► Significantly higher levels of manganese and uranium in peripheral blood samples. ► Significant DNA damages detected by the comet assay. ► Significant decrease of NK and T lymphocytes counts in exposed individuals. ► Concerns on the risks of human populations living nearby uranium mining areas. - Abstract: Environmental exposure to uranium and its daughter radionuclides, has been linked to several negative effects such as those related with important physiological processes, like hematopoiesis, and may also be associated with genotoxicity effects. Herein, genotoxic effects, immunotoxicity, trace elements and C reactive protein (CRP) analyses, were performed in peripheral blood samples collected from individuals of a population living near a deactivated uranium mine. C reactive protein analysis was performed to exclude candidates with active inflammatory processes from further evaluations. DNA damage and immunotoxicity (immunophenotyping and immune cell counts) were evaluated by comet assay and flow cytometry, respectively. Significant DNA damage was observed in the peripheral blood samples from volunteers living in the Cunha Baixa village. A significant decrease of NK and T lymphocytes counts were observed in the individuals from the Cunha Baixa village, when compared with individuals from the reference site. Uranium and manganese levels were significantly higher in the Cunha Baixa village inhabitants. On the other hand, zinc levels were significantly lower in those individuals when compared with the volunteers from the control village. Results suggest that inhabitants from Cunha Baixa have a higher risk of suffering from serious diseases such as cancer, since high DNA damages were observed in peripheral blood leukocytes and also decreased levels of NK and T cells, which play an essential role in the defense against tumor growth

  17. Decommissioning and deactivation of nuclear facilities

    International Nuclear Information System (INIS)

    The National Atomic Energy Commission (CNEA) is responsible for the decommissioning and deactivation of all relevant nuclear facilities in Argentina. A D and D Subprogram was created in 2000, within Technology Branch of the CNEA, in order to fulfill this responsibility. The D and D Subprogram has organized its activities in four fields: Planning; Technology development; Human resources development and training; International cooperation. The paper describes the work already done in those 4 areas, as well as the nuclear facilities existing in the country. Planning is being developed for the decommissioning of research reactors, beginning with RA-1, as well as for the Atucha I nuclear power station. An integral Management System has been developed, compatibilizing requirements from ISO 9001, ISO 14001, the national norm for Safety and Occupational Health (equivalent to BS 8800), and IAEA 50-SG Q series. Technology development is for the time being concentrated on mechanical decontamination and concrete demolition. A review has been made of technologies already developed both by CNEA and Nucleoelectrica Argentina S.A. (the nuclear power utility) in areas of chemical and electrochemical decontamination, cutting techniques and robotics. Human resources development has been based on training abroad in the areas of decontamination, cutting techniques, quality assurance and planning, as well as on specific courses, seminars and workshops. An IAEA regional training course on D and D has been given on April 2002 at CNEA's Constituyentes Atomic Center, with the assistance of 22 university graduates from 13 countries in the Latin American and Caribbean Region, and 11 from Argentina. CNEA has also given fellowships for PhD and Master thesis on the subject. International cooperation has been intense, and based on: - IAEA Technical Cooperation Project and experts missions; - Cooperation agreement with the US Department of Energy; - Cooperation agreement with Germany

  18. Prognostic value of posteromedial cortex deactivation in mild cognitive impairment.

    Directory of Open Access Journals (Sweden)

    Jeffrey R Petrella

    Full Text Available BACKGROUND: Normal subjects deactivate specific brain regions, notably the posteromedial cortex (PMC, during many tasks. Recent cross-sectional functional magnetic resonance imaging (fMRI data suggests that deactivation during memory tasks is impaired in Alzheimer's disease (AD. The goal of this study was to prospectively determine the prognostic significance of PMC deactivation in mild cognitive impairment (MCI. METHODOLOGY/PRINCIPAL FINDINGS: 75 subjects (34 MCI, 13 AD subjects and 28 controls underwent baseline fMRI scanning during encoding of novel and familiar face-name pairs. MCI subjects were followed longitudinally to determine conversion to AD. Regression and analysis of covariance models were used to assess the effect of PMC activation/deactivation on conversion to dementia as well as in the longitudinal change in dementia measures. At longitudinal follow up of up to 3.5 years (mean 2.5+/-0.79 years, 11 MCI subjects converted to AD. The proportion of deactivators was significantly different across all groups: controls (79%, MCI-Nonconverters (73%, MCI-converters (45%, and AD (23% (p<0.05. Mean PMC activation magnitude parameter estimates, at baseline, were negative in the control (-0.57+/-0.12 and MCI-Nonconverter (-0.33+/-0.14 groups, and positive in the MCI-Converter (0.37+/-0.40 and AD (0.92+/-0.30 groups. The effect of diagnosis on PMC deactivation remained significant after adjusting for age, education and baseline Mini-Mental State Exam (p<0.05. Baseline PMC activation magnitude was correlated with change in dementia ratings from baseline. CONCLUSION: Loss of physiological functional deactivation in the PMC may have prognostic value in preclinical AD, and could aid in profiling subgroups of MCI subjects at greatest risk for progressive cognitive decline.

  19. Mitigation of Hydrogen Gas Generation from the Reaction of Uranium Metal with Water in K Basin Sludge and Sludge Waste Forms

    Energy Technology Data Exchange (ETDEWEB)

    Sinkov, Sergey I.; Delegard, Calvin H.; Schmidt, Andrew J.

    2011-06-08

    Prior laboratory testing identified sodium nitrate and nitrite to be the most promising agents to minimize hydrogen generation from uranium metal aqueous corrosion in Hanford Site K Basin sludge. Of the two, nitrate was determined to be better because of higher chemical capacity, lower toxicity, more reliable efficacy, and fewer side reactions than nitrite. The present lab tests were run to determine if nitrate’s beneficial effects to lower H2 generation in simulated and genuine sludge continued for simulated sludge mixed with agents to immobilize water to help meet the Waste Isolation Pilot Plant (WIPP) waste acceptance drainable liquid criterion. Tests were run at ~60°C, 80°C, and 95°C using near spherical high-purity uranium metal beads and simulated sludge to emulate uranium-rich KW containerized sludge currently residing in engineered containers KW-210 and KW-220. Immobilization agents tested were Portland cement (PC), a commercial blend of PC with sepiolite clay (Aquaset II H), granulated sepiolite clay (Aquaset II G), and sepiolite clay powder (Aquaset II). In all cases except tests with Aquaset II G, the simulated sludge was mixed intimately with the immobilization agent before testing commenced. For the granulated Aquaset II G clay was added to the top of the settled sludge/solution mixture according to manufacturer application directions. The gas volumes and compositions, uranium metal corrosion mass losses, and nitrite, ammonia, and hydroxide concentrations in the interstitial solutions were measured. Uranium metal corrosion rates were compared with rates forecast from the known uranium metal anoxic water corrosion rate law. The ratios of the forecast to the observed rates were calculated to find the corrosion rate attenuation factors. Hydrogen quantities also were measured and compared with quantities expected based on non-attenuated H2 generation at the full forecast anoxic corrosion rate to arrive at H2 attenuation factors. The uranium metal

  20. Deactivation by carbon of iron catalysts for indirect liquefaction

    Energy Technology Data Exchange (ETDEWEB)

    Bartholomew, C H

    1991-02-14

    Progress is reported for a four-year fundamental investigation of carbon formation and its effects on the activity and selectivity of promoted iron catalysts for FT synthesis, the objectives of which were to (1) determine rates and mechanisms of carbon deactivation of unsupported Fe and Fe/K catalysts during CO hydrogenation and (2) model the global rates of deactivation at the surface of the catalyst for the same catalysts. A computer-automated reactor system to be used in the kinetic and deactivation studies was designed, constructed and tested. Kinetic data for CO hydrogenation on unsupported, unpromoted iron, 99% Fe/1% Al{sub 2}O{sub 3}, and K-promoted 99% Fe/1% Al{sub 2}O{sub 3} catalysts were obtained as functions of temperature, reactant particle pressures and time. The activity/selectivity and kinetic data are consistent with those previously reported for supported, unpromoted and promoted iron. Two kinds of deactivation were observed during FT synthesis on these samples: (1) loss of surface area after reduction of unsupported, unpromoted iron at 400{degree}C and (2) loss of activity with time due to carbon deposition, especially in the case of K-promoted 99% Fe/1% A1{sub 2}O{sub 3}. Deactivation rate data were obtained for CO hydrogenation on promoted Fe as a function of time, temperature, and H{sub 2}/CO ratio. 50 refs., 24 figs., 5 tabs.

  1. Deactivation by carbon of iron catalysts for indirect liquefaction

    Energy Technology Data Exchange (ETDEWEB)

    Bartholomew, C.H.

    1991-01-10

    Although promoted cobalt and iron catalysts for Fischer-Tropsch (FT) synthesis of gasoline feedstock were first developed more than three decades ago, a major technical problem still limiting the commercial use of these catalysts today is carbon deactivation. This report describes recent progress in a fundamental, three-year investigation of carbon formation and its effects on the activity and selectivity of promoted iron catalysts for FT synthesis, the objectives of which are to: determine rates and mechanisms of carbon deactivation of unsupported Fe and Fe/K catalysts during CO hydrogenation over a range of CO concentrations, CO:H{sub 2} ratios, and temperatures; and model the rates of deactivation of the same catalysts in fixed-bed reactors. To accomplish the above objectives, the project is divided into the following tasks: (1) determine the kinetics of reaction and of carbon deactivation during CO hydrogenation on Fe and Fe/K catalysts coated on monolith bodies. (2) Determine the reactivities and types of carbon deposited during reaction on the same catalysts from temperature-programmed-surface-reaction spectroscopy (TPSR) and transmission electron microscopy (TEM). Determine the types of iron carbides formed at various temperatures and H{sub 2}/CO ratios using x-ray diffraction and Moessbauer spectroscopy. (3) Develop mathematical deactivation models which include heat and mass transport contributions for FT synthesis is packed-bed reactors. Progress to date is described. 48 refs., 3 figs., 1 tab.

  2. Self-deactivation of water vapor - Role of the dimer

    Science.gov (United States)

    Zuckerwar, A. J.

    1984-01-01

    A phenomenological multiple-relaxation theory of the deactivation rate constant for the nu-2 (1 - 0) bending mode of water vapor is presented which incorporates the role not only of the excited monomer but also of the bound molecular complex, in particular the dimer. The deactivation takes place by means of three parallel processes: (1) collisional deexcitation of the excited monomer, (2) a two-step reaction involving association and spontaneous redissociation of an H2O collision complex, and (3) spontaneous dissociation of the stably bound H2O dimer. Oxygen, but not nitrogen or argon, serves as an effective chaperon for the formation of the activated complex. This observation explains the impurity dependence of the self-deactivation rate constant of water vapor. Analysis of an ultrasonic absorption peak based on the third process yields values for the standard entropy and enthalpy of dissociation of the stably bound H2O dimer.

  3. PUREX/UO3 facilities deactivation lessons learned history

    International Nuclear Information System (INIS)

    The Plutonium-Uranium Extraction (PUREX) Facility operated from 1956-1972, from 1983-1988, and briefly during 1989-1990 to produce for national defense at the Hanford Site in Washington State. The Uranium Trioxide (UO3) Facility operated at the Hanford Site from 1952-1972, 1984-1988, and briefly in 1993. Both plants were ordered to permanent shutdown by the U.S. Department of Energy (DOE) in December 1992, thus initiating their deactivation phase. Deactivation is that portion of a facility's life cycle that occurs between operations and final decontamination and decommissioning (D ampersand D). This document details the history of events, and the lessons learned, from the time of the PUREX Stabilization Campaign in 1989-1990, through the end of the first full fiscal year (FY) of the deactivation project (September 30, 1994)

  4. Deactivation by carbon of iron catalysts for indirect liquefaction

    Energy Technology Data Exchange (ETDEWEB)

    Bartholomew, C.H.

    1990-10-29

    This report describes recent progress in a fundamental, three-year investigation of carbon formation and its effects on the activity and selectivity of promoted iron catalysts for synthesis, the objectives of which are: determine rates and mechanisms of carbon deactivation of unsupported Fe and Fe/K catalysts during CO hydrogenation over a range of CO concentrations, CO:H{sub 2} ratios, and temperatures; model the rates of deactivation of the same catalysts in fixed-bed reactors. During the fourteenth quarter design of software for a computer-automated reactor system to be used in the kinetic and deactivation studies was continued. Further progress was made toward the completion of the control language, control routines, and software for operating this system. Progress was also made towards testing of the system hardware and software. 47 refs.

  5. Kinetics with deactivation of methylcyclohexane dehydrogenation for hydrogen energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Maria, G.; Marin, A.; Wyss, C.; Mueller, S.; Newson, E. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    The methylcyclohexane dehydrogenation step to recycle toluene and release hydrogen is being studied as part of a hydrogen energy storage project. The reaction is performed catalytically in a fixed bed reactor, and the efficiency of this step significantly determines overall system economics. The fresh catalyst kinetics and the deactivation of the catalyst by coke play an important role in the process analysis. The main reaction kinetics were determined from isothermal experiments using a parameter sensitivity analysis for model discrimination. An activation energy for the main reaction of 220{+-}11 kJ/mol was obtained from a two-parameter model. From non-isothermal deactivation in PC-controlled integral reactors, an activation energy for deactivation of 160 kJ/mol was estimated. A model for catalyst coke content of 3-17 weight% was compared with experimental data. (author) 3 figs., 6 refs.

  6. Robot Work Platform for Large Hot Cell Deactivation

    Energy Technology Data Exchange (ETDEWEB)

    BITTEN, E.J.

    2000-05-01

    The 324 Building, located at the Hanford Site near Richland, Washington, is being deactivated to meet state and federal cleanup commitments. The facility is currently in its third year of a nine-year project to complete deactivation and closure for long-term surveillance and maintenance. The 324 building contains large hot cells that were used for high-radiation, high-contamination chemical process development and demonstrations. A major obstacle for the 324 deactivation project is the inability to effectively perform deactivation tasks within highly radioactive, contaminated environments. Current strategies use inefficient, resource intensive technologies that significantly impact the cost and schedule for deactivation. To meet mandated cleanup commitments, there is a need to deploy rapid, more efficient remote/robot technologies to minimize worker exposure, accelerate work tasks, and eliminate the need for multiple specialized tool design and procurement efforts. This paper describes the functions and performance requirements for a crane-deployed remote/robot Work Platform possessing full access capabilities. The remote/robot Work Platform will deploy commercially available off-the-shelf tools and end effectors to support Project cleanup goals and reduce overall project risk and cost. The intent of this system is to maximize the use of off-the-shelf technologies that minimize additional new, unproven, or novel designs. This paper further describes procurement strategy, the selection process, the selected technology, and the current status of the procurement and lessons learned. Funding, in part, has been provided by the US Department of Energy, Office of Science and Technology, Deactivation and Decommissioning Focus Area.

  7. Characterization of deactivated bio-oil hydrotreating catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Huamin; Wang, Yong

    2016-01-18

    Deactivation of bio-oil hydrotreating catalysts remains a significant challenge because of the poor quality of pyrolysis bio-oil input for hydrotreating and understanding their deactivation mode is critical to developing improved catalysts and processes. In this research, we developed an understanding of the deactivation of two-step bio-oil hydrotreating catalysts (sulfided Ru/C and sulfided CoMo/C) through detailed characterization of the catalysts using various complimentary analytical techniques. Severe fouling of both catalysts by carbonaceous species was the major form of deactivation, which is consistent with the significant loss of surface area and pore volume of both deactivated catalysts and the significant increase of the bulk density. Further analysis of the carbonaceous species by thermogravimetric analysis and x-ray photoelectron spectroscopy indicated that the carbonaceous species was formed by condensation reaction of active species such as sugars and sugar derivatives (aldehydes and ketones) in bio-oil feedstock during bio-oil hydrotreating under the conditions and catalysts used. Microscopy results did not show metal sintering of the Ru/C catalyst. However, X-ray diffraction indicated a probable transformation of the highly-active CoMoS phase in the sulfided CoMo/C catalyst to Co8S9 and MoS2 phase with low activity. Loss of the active site by transport of inorganic elements from the bio-oil and the reactor construction material onto the catalyst surface also might be a cause of deactivation as indicated by elemental analysis of spent catalysts.

  8. Robot Work Platform for Large Hot Cell Deactivation

    International Nuclear Information System (INIS)

    The 324 Building, located at the Hanford Site near Richland, Washington, is being deactivated to meet state and federal cleanup commitments. The facility is currently in its third year of a nine-year project to complete deactivation and closure for long-term surveillance and maintenance. The 324 building contains large hot cells that were used for high-radiation, high-contamination chemical process development and demonstrations. A major obstacle for the 324 deactivation project is the inability to effectively perform deactivation tasks within highly radioactive, contaminated environments. Current strategies use inefficient, resource intensive technologies that significantly impact the cost and schedule for deactivation. To meet mandated cleanup commitments, there is a need to deploy rapid, more efficient remote/robot technologies to minimize worker exposure, accelerate work tasks, and eliminate the need for multiple specialized tool design and procurement efforts. This paper describes the functions and performance requirements for a crane-deployed remote/robot Work Platform possessing full access capabilities. The remote/robot Work Platform will deploy commercially available off-the-shelf tools and end effectors to support Project cleanup goals and reduce overall project risk and cost. The intent of this system is to maximize the use of off-the-shelf technologies that minimize additional new, unproven, or novel designs. This paper further describes procurement strategy, the selection process, the selected technology, and the current status of the procurement and lessons learned. Funding, in part, has been provided by the US Department of Energy, Office of Science and Technology, Deactivation and Decommissioning Focus Area

  9. PUREX/UO3 facilities deactivation lessons learned history

    International Nuclear Information System (INIS)

    In May 1997, a historic deactivation project at the PUREX (Plutonium URanium EXtraction) facility at the Hanford Site in south-central Washington State concluded its activities (Figure ES-1). The project work was finished at $78 million under its original budget of $222.5 million, and 16 months ahead of schedule. Closely watched throughout the US Department of Energy (DOE) complex and by the US Department of Defense for the value of its lessons learned, the PUREX Deactivation Project has become the national model for the safe transition of contaminated facilities to shut down status

  10. PUREX/UO{sub 3} facilities deactivation lessons learned: History

    Energy Technology Data Exchange (ETDEWEB)

    Gerber, M.S.

    1997-11-25

    In May 1997, a historic deactivation project at the PUREX (Plutonium URanium EXtraction) facility at the Hanford Site in south-central Washington State concluded its activities (Figure ES-1). The project work was finished at $78 million under its original budget of $222.5 million, and 16 months ahead of schedule. Closely watched throughout the US Department of Energy (DOE) complex and by the US Department of Defense for the value of its lessons learned, the PUREX Deactivation Project has become the national model for the safe transition of contaminated facilities to shut down status.

  11. Geology and geohydrology of the East Texas Basin. A report on the progress of nuclear waste isolation feasibility studies (1980)

    International Nuclear Information System (INIS)

    The third year of research was highlighted by the integration of regional basinal studies with growth histories for specific domes, studies of cap-rock diagenesis and salt deformation, preliminary studies of ground-water flow and geochemistry around Oakwood Dome, and preliminary studies of microseismicity in the Mount Enterprise fault zone. 119 figures, 15 tables

  12. Isotopic detection of waste water disposal in deep pre-tertiary aquifers in the Weisselster basin, Central Germany

    International Nuclear Information System (INIS)

    In the Central German lignite mining area pumping of ground water along with mining activities have caused severe hydraulic disturbances in the aquifer system. Moreover in the period from 1940's to mid 1970's coal processing companies injected phenolic waste water into abandoned mining pits and deep Upper Permian Zechstein aquifers. A spatial analysis of the data from 350 drillings allowed to characterise the subsurface geology; phenolic waste water traces were found in Zechstein aquifer

  13. DMPD: Molecular mechanisms of macrophage activation and deactivation bylipopolysaccharide: roles of the receptor complex. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 14609719 Molecular mechanisms of macrophage activation and deactivation bylipopolysaccharide: role...ivation and deactivation bylipopolysaccharide: roles of the receptor complex. Pub...medID 14609719 Title Molecular mechanisms of macrophage activation and deactivation bylipopolysaccharide: role

  14. Combustion kinetics of the coke on deactivated dehydrogenation catalysts

    NARCIS (Netherlands)

    Luo, Sha; He, Songbo; Li, XianRu; Li, Jingqiu; Bi, Wenjun; Sun, Chenglin

    2015-01-01

    The coke combustion kinetics on the deactivated catalysts for long chain paraffin dehydrogenation was studied by the thermogravimetry and differential thermogravimetry (TG–DTG) technique. The amount and H/C mole ratio of the coke were determined by the TG and elemental analysis. And the comprehensiv

  15. Temperature and deactivation of microbial faecal indicators during small scale co-composting of faecal matter.

    Science.gov (United States)

    Germer, Jörn; Boh, Michael Yongha; Schoeffler, Marie; Amoah, Philip

    2010-02-01

    Small scale co-composting of faecal matter from dry toilet systems with shredded plant material and food waste was investigated in respect to heat development and deactivation of faecal indicators under tropical semiarid conditions. Open (uncovered) co-composting of faecal matter with shredded plant material alone did not generate temperatures high enough (regulations. The reduction of Escherichia coli, Enterococcus faecalis and Salmonella senftenberg in test containment systems placed in the core of the compost piles was very efficient, exceeding 5log10-units in all cases, but recolonisation from the cooler outer layers appeared to interfere with the sanitisation efficiency of the substrate itself. The addition of a stabilisation period by extending the composting process to over 4 months ensured that the load of E. coli was reduced to less than 10(3)cfu(-g) and salmonella were undetectable.

  16. Aromatization of light naphtha fractions on zeolites: 2. Model of catalyst deactivation

    OpenAIRE

    Ostrovski Nikolaj M.; Rovenskaja Svetlana A.; Echevski Genadij V.

    2004-01-01

    A model of catalyst deactivation in the "Zeoforming" process was developed. The deactivation rate constants and activation energies were estimated. The role of adsorbed oligomers in the reaction and the deactivation kinetics were examined. The model is intended for further modeling and optimization of the process.

  17. Efficient Methanol Synthesis Catalysts: Long-Term Stability and Deactivation Phenomena

    OpenAIRE

    Fichtl, Matthias

    2014-01-01

    In this thesis the deactivation mechanism on different coprecipitated Cu/ZnO/Al2O3 methanol synthesis catalysts is evaluated. Transmission electron microcopy, X-ray diffraction, chemisorption methods and modeling techniques are applied to correlate the deactivation behavior with structural changes in the active catalyst. Updated models for the catalyst microstructure and deactivation behavior are presented.

  18. Aromatization of light naphtha fractions on zeolites: 2. Model of catalyst deactivation

    Directory of Open Access Journals (Sweden)

    Ostrovski Nikolaj M.

    2004-01-01

    Full Text Available A model of catalyst deactivation in the "Zeoforming" process was developed. The deactivation rate constants and activation energies were estimated. The role of adsorbed oligomers in the reaction and the deactivation kinetics were examined. The model is intended for further modeling and optimization of the process.

  19. Model dependences of the deactivation of phytoplankton pigment excitation energy on environmental conditions in the sea

    Directory of Open Access Journals (Sweden)

    Mirosława Ostrowska

    2012-11-01

    Full Text Available A semi-empirical, physical models have been derived of the quantum yield ofthe deactivation processes (fluorescence, photosynthesis and heat productionof excited states in phytoplankton pigment molecules. Besides some alreadyknown models (photosynthesis and fluorescence, this novel approachincorporates the dependence of the dissipation yield of the excitation energyin phytoplankton pigment molecules on heat. The quantitative dependences ofthe quantum yields of these three processes on three fundamental parameters ofthe marine environment are defined: the chlorophyll concentration in the surface water layer Ca(0 (the basin trophicity,the irradiance PAR(z and the temperature temp(z at the study site.The model is complemented with two other relevant models describing thequantum yield of photosynthesis and of natural Sun-Induced Chlorophyll a Fluorescence (SICF in the sea, derived earlier by the author or with herparticipation on the basis of statistical analyses of a vast amount ofempirical material. The model described in the present paper enables theestimation of the quantum yields of phytoplankton pigment heat production forany region and season, in waters of any trophicity at different depths fromthe surface to depths of ca 60 m. The model can therefore be used to estimatethe yields of these deactivation processes in more than half the thickness ofthe euphotic zone in oligotrophic waters and in the whole thickness (anddeeper of this zone in mesotrophic and eutrophic waters. In particular theserelationships may be useful for a component analysis of the budget of lightenergy absorbed by phytoplankton pigments, namely, its utilization influorescence, photochemical quenching and nonphotochemical radiationlessdissipation - i.e. direct heat production.

  20. Novel C-Ring-Hydroxy-Substituted Controlled Deactivation Cannabinergic Analogues.

    Science.gov (United States)

    Kulkarni, Shashank; Nikas, Spyros P; Sharma, Rishi; Jiang, Shan; Paronis, Carol A; Leonard, Michael Z; Zhang, Bin; Honrao, Chandrashekhar; Mallipeddi, Srikrishnan; Raghav, Jimit Girish; Benchama, Othman; Järbe, Torbjörn U C; Bergman, Jack; Makriyannis, Alexandros

    2016-07-28

    In pursuit of safer controlled-deactivation cannabinoids with high potency and short duration of action, we report the design, synthesis, and pharmacological evaluation of novel C9- and C11-hydroxy-substituted hexahydrocannabinol (HHC) and tetrahydrocannabinol (THC) analogues in which a seven atom long side chain, with or without 1'-substituents, carries a metabolically labile 2',3'-ester group. Importantly, in vivo studies validated our controlled deactivation approach in rodents and non-human primates. The lead molecule identified here, namely, butyl-2-[(6aR,9R,10aR)-1-hydroxy-9-(hydroxymethyl)-6,6-dimethyl-6a,7,8,9,10,10a-hexahydro-6H-benzo[c]chromen-3-yl]-2-methylpropanoate (AM7499), was found to exhibit remarkably high in vitro and in vivo potency with shorter duration of action than the currently existing classical cannabinoid agonists. PMID:27367336

  1. Insights into the Deactivation of 5-Bromouracil after UV Excitation

    CERN Document Server

    Peccati, Francesca; González, Leticia

    2016-01-01

    5-Bromouracil is a nucleobase analogue that can replace thymine in DNA strands and acts as a strong radiosensitizer, with potential applications in molecular biology and cancer therapy. Here, the deactivation of 5-bromouracil after UV irradiation is investigated in the singlet and triplet manifold by accurate quantum chemistry calculations and nonadiabatic dynamics simulations. It is found that after irradiation to the bright 1pipi* state, three main relaxation pathways are in principle possible: relaxation back to the ground state, intersystem crossing, and C-Br photodissociation. Based on accurate MS-CASPT2 optimizations, we propose that ground state relaxation should be the predominant deactivation pathway in gas phase. We then employ different electronic structure methods to assess their suitability to carry out excited-state dynamics simulations. MRCIS was used in surface hopping simulations to compute the ultrafast intersystem crossing dynamics, which mostly involves the 1nOpi* and 3pipi* states.

  2. Deactivation of SCR catalysts in biomass fired power plants

    DEFF Research Database (Denmark)

    Olsen, Brian Kjærgaard

    in such biomass fuels, however, causes enhanced strain on the different equipment in these power plants. One of the affected units is the catalyst for selective catalytic reduction (SCR) of nitrogen oxides, which undergoes accelerated deactivation due to deposition of potassium rich particles and subsequent...... poisoning. The potassium poisoning of commercial vanadia based SCR catalysts have been studied for more than two decades, and a broad understanding have been obtained. However, more detailed information on the overall mechanism of deposition, reaction and transport of potassium, and its function of catalyst...... composition and operating conditions, is not available. The main objective of the work presented in this thesis has been to conduct an in depth investigation of the deactivation mechanism of vanadia based SCR catalysts, when subjected to potassium rich aerosols. It has furthermore been a goal to suggest...

  3. Mechanism of acetaldehyde-induced deactivation of microbial lipases

    Directory of Open Access Journals (Sweden)

    Jaeger Karl E

    2011-02-01

    Full Text Available Abstract Background Microbial lipases represent the most important class of biocatalysts used for a wealth of applications in organic synthesis. An often applied reaction is the lipase-catalyzed transesterification of vinyl esters and alcohols resulting in the formation of acetaldehyde which is known to deactivate microbial lipases, presumably by structural changes caused by initial Schiff-base formation at solvent accessible lysine residues. Previous studies showed that several lipases were sensitive toward acetaldehyde deactivation whereas others were insensitive; however, a general explanation of the acetaldehyde-induced inactivation mechanism is missing. Results Based on five microbial lipases from Candida rugosa, Rhizopus oryzae, Pseudomonas fluorescens and Bacillus subtilis we demonstrate that the protonation state of lysine ε-amino groups is decisive for their sensitivity toward acetaldehyde. Analysis of the diverse modification products of Bacillus subtilis lipases in the presence of acetaldehyde revealed several stable products such as α,β-unsaturated polyenals, which result from base and/or amino acid catalyzed aldol condensation of acetaldehyde. Our studies indicate that these products induce the formation of stable Michael-adducts at solvent-accessible amino acids and thus lead to enzyme deactivation. Further, our results indicate Schiff-base formation with acetaldehyde to be involved in crosslinking of lipase molecules. Conclusions Differences in stability observed with various commercially available microbial lipases most probably result from different purification procedures carried out by the respective manufacturers. We observed that the pH of the buffer used prior to lyophilization of the enzyme sample is of utmost importance. The mechanism of acetaldehyde-induced deactivation of microbial lipases involves the generation of α,β-unsaturated polyenals from acetaldehyde which subsequently form stable Michael-adducts with the

  4. Default network deactivations are correlated with psychopathic personality traits.

    Directory of Open Access Journals (Sweden)

    Tong Sheng

    Full Text Available BACKGROUND: The posteromedial cortex (PMC and medial prefrontal cortex (mPFC are part of a network of brain regions that has been found to exhibit decreased activity during goal-oriented tasks. This network is thought to support a baseline of brain activity, and is commonly referred to as the "default network". Although recent reports suggest that the PMC and mPFC are associated with affective, social, and self-referential processes, the relationship between these default network components and personality traits, especially those pertaining to social context, is poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: In the current investigation, we assessed the relationship between PMC and mPFC deactivations and psychopathic personality traits using fMRI and a self-report measure. We found that PMC deactivations predicted traits related to egocentricity and mPFC deactivations predicted traits related to decision-making. CONCLUSIONS/SIGNIFICANCE: These results suggest that the PMC and mPFC are associated with processes involving self-relevancy and affective decision-making, consistent with previous reports. More generally, these findings suggest a link between default network activity and personality traits.

  5. Deactivation of metastable single-crystal silicon hyperdoped with sulfur

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, C. B.; Akey, Austin J.; Sullivan, Joseph T.; Buonassisi, Tonio [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Krich, Jacob J. [University of Ottawa, Ottawa, Ontario K1N 6N5 (Canada); Recht, Daniel; Aziz, Michael J. [Harvard School of Engineering and Applied Sciences, Cambridge, Massachusetts 02138 (United States)

    2013-12-28

    Silicon supersaturated with sulfur by ion implantation and pulsed laser melting exhibits broadband optical absorption of photons with energies less than silicon's band gap. However, this metastable, hyperdoped material loses its ability to absorb sub-band gap light after subsequent thermal treatment. We explore this deactivation process through optical absorption and electronic transport measurements of sulfur-hyperdoped silicon subject to anneals at a range of durations and temperatures. The deactivation process is well described by the Johnson-Mehl-Avrami-Kolmogorov framework for the diffusion-mediated transformation of a metastable supersaturated solid solution, and we find that this transformation is characterized by an apparent activation energy of E{sub A}=1.7 ± 0.1 eV. Using this activation energy, the evolution of the optical and electronic properties for all anneal duration-temperature combinations collapse onto distinct curves as a function of the extent of reaction. We provide a mechanistic interpretation of this deactivation based on short-range thermally activated atomic movements of the dopants to form sulfur complexes.

  6. Gamification of learning deactivates the Default Mode Network

    Directory of Open Access Journals (Sweden)

    Paul Alexander Howard-Jones

    2016-01-01

    Full Text Available We hypothesised that embedding educational learning in a game would improve learning outcomes, with increased engagement and recruitment of cognitive resources evidenced by increased activation of working memory network (WMN and deactivation of Default Mode Network (DMN regions. In an fMRI study, we compared activity during periods of learning in three conditions that were increasingly game-like: Study-only (when periods of learning were followed by an exemplar question together with its correct answer, Self-quizzing (when periods of learning were followed by a multiple choice question in return for a fixed number of points and Game-based (when, following each period of learning, participants competed with a peer to answer the question for escalating, uncertain rewards. DMN hubs deactivated as conditions became more game-like, alongside greater self-reported engagement and, in the Game-based condition, higher learning scores. These changes did not occur with any detectable increase in WMN activity. Additionally, ventral striatal activation was associated with responding to questions and receiving positive question feedback. Results support the significance of DMN deactivation for educational learning, and are aligned with recent evidence suggesting DMN and WMN activity may not always be anti-correlated.

  7. Gamification of Learning Deactivates the Default Mode Network.

    Science.gov (United States)

    Howard-Jones, Paul A; Jay, Tim; Mason, Alice; Jones, Harvey

    2015-01-01

    We hypothesized that embedding educational learning in a game would improve learning outcomes, with increased engagement and recruitment of cognitive resources evidenced by increased activation of working memory network (WMN) and deactivation of default mode network (DMN) regions. In an fMRI study, we compared activity during periods of learning in three conditions that were increasingly game-like: Study-only (when periods of learning were followed by an exemplar question together with its correct answer), Self-quizzing (when periods of learning were followed by a multiple choice question in return for a fixed number of points) and Game-based (when, following each period of learning, participants competed with a peer to answer the question for escalating, uncertain rewards). DMN hubs deactivated as conditions became more game-like, alongside greater self-reported engagement and, in the Game-based condition, higher learning scores. These changes did not occur with any detectable increase in WMN activity. Additionally, ventral striatal activation was associated with responding to questions and receiving positive question feedback. Results support the significance of DMN deactivation for educational learning, and are aligned with recent evidence suggesting DMN and WMN activity may not always be anti-correlated. PMID:26779054

  8. Deactivation by carbon of iron catalysts for indirect liquefaction

    Energy Technology Data Exchange (ETDEWEB)

    Bartholomew, C.H.

    1990-10-11

    This report describes recent progress in a fundamental, three-year investigation of carbon formation and its effects on the activity and selectivity of promoted iron catalysts for Fischer-Tropsch (FT) synthesis, the objectives of which are: determine rates and mechanisms of carbon deactivation of unsupported Fe and Fe/K catalysts during CO hydrogenation over a range of CO concentrations, CO:H{sub 2} ratios, and temperatures; model the rates of deactivation of the same catalysts in fixed-bed reactors. During the thirteenth quarter design of software for a computer-automated reactor system to be used in the kinetic and deactivation studies was continued. Further progress was made toward the completion of the control language, control routines, and software for operating this system. Progress was also made on the testing of the system hardware and software. H{sub 2} chemisorption capacities and activity selectivity data were also measured for three iron catalysts promoted with 1% alumina. 47 refs., 8 figs., 1 tab.

  9. Thermal stability and deactivation energy of free and immobilized invertase

    Directory of Open Access Journals (Sweden)

    F.J. Bassetti

    2000-12-01

    Full Text Available The thermal stability and the energy of deactivation of free invertase and the immobilized enzyme (IE was measured at temperatures in the range of 35 to 65°C for the hydrolysis of a 5% w/v sucrose solution. The free enzyme at pH 5.0 is stable up to 50°C for a period of 4 h. Invertase immobilized in controlled pore silica by the silane-glutaraldehyde covalent method is stable up to 55ºC, in pH 4.5 for the same period. For higher temperatures the enzyme deactivation follows the exponential decay model and half-lives are 0.53, 1.80, and 13.9 h for free invertase, at 65, 60, and 55ºC, respectively. For the IE half-lives are 0.48, 1.83, and 20.9 h, at 65, 60, and 55ºC, respectively. The IE is more stable than the free invertase; the energy of deactivation being 83.1 kcal/mol for the IE and 72.0 kcal/mol for the free enzyme.

  10. Geochemical Variability and the Potential for Beneficial Use of Waste Water Coproduced with Oil from Permian Basin of the Southwest USA

    Science.gov (United States)

    Khan, N. A.; Holguin, F. O.; Xu, P.; Engle, M.; Dungan, B.; Hunter, B.; Carroll, K. C.

    2014-12-01

    The U.S. generates 21 billion barrels/year of coproduced water from oil and gas exploration, which is generally considered waste water. Growth in unconventional oil and gas production has spurred interest in beneficial uses of produced water, especially in arid regions such as the Permian Basin of Texas and New Mexico, the largest U.S. tight oil producer. Produced waters have variable chemistries, but generally contain high levels of organics and salts. In order to evaluate the environmental impact, treatment, and reuse potential, there is a need to characterize the compositional variability of produced water. In the present study, produced water samples were collected from 12 wells across the Permian Basin. Compositional analyses including coupled gas chromatography-time of flight-mass spectrometry and inductively coupled plasma-optical emission spectroscopy were conducted. The samples show elevated benzene, ethylbenzene, toluene, xylene, alkyl benzenes, propyl-benzene, and naphthalene compared to other heteroaromatics; they also contain complex hydrocarbon compounds containing oxygen, nitrogen, and sulfur. Van Krevelen diagrams show an increase in the concentration of heteroaromatic hydrocarbons with increasing well depth. The salinity, dominated by sodium-chloride, also increases with depth, ranging from 37-150 g/L TDS. Depth of wells (or producing formation) is a primary control on predicting water quality for treatment and beneficial use. Our results suggest that partial treatment by removing suspended solids and organic contaminants would support some beneficial uses such as onsite reuse, bioenergy production, and other industrial uses. Due to the high salinity, conventional desalination processes are not applicable or very costly, making beneficial uses requiring low salinity not feasible.

  11. The use of genetic bioassays to evaluate the environmental quality in a region under the influence of urban waste in Guaíba lake basin (Brazil

    Directory of Open Access Journals (Sweden)

    Izabel Vianna Villela

    2013-06-01

    Full Text Available The mussel species Limnoperna fortunei was chosen as biomonitoring organism in Guaíba Lake Basin, based on population data, distribution, and sensitivity. Previous in vitro and in vivo studies studies with Single Cell Gel Assay (SCGA and Micronuclei test (MN on this freshwater mussel showed that it is successful in biomonitoring studies, especially in urban pollution monitoring. This study evaluated two sampling sites in the Guaíba Lake (Guaíba PC e Guaíba BR, near urban waste discharges, and a control site (Itapuã insight a preserved area, using L. fortunei individuals. Comparing to the control site, the Guaíba BR sample induced DNA damage in haemocytes of mussels sampled both in situ and exposed to laboratory conditions, whereas MN only in in situ collected mussels. This sample also presented the only surface water mutagenic result by Salmonella/microsome assay with TA98 in the presence of metabolic activation. Guaíba PC samples increased MN frequency in situ and in laboratory conditions comparing to the Itapuã results. Metal influence seems to be less important than organic influence in genotoxic induction. These results confirm the strong urban influence in this region, showing that biomonitoring is a powerful tool to detect this kind of contamination in water bodies.

  12. Geologic report of the Maquoketa Shale, New Albany Shale, and Borden Group rocks in the Illinois Basin as potential solid waste repository sites

    International Nuclear Information System (INIS)

    We have evaluated the Illinois Basin in order to select a ''target site'' for a possible solid nuclear waste repository. In the process we have been mindful of geology (particularly stratigraphy and lithology and structure), terrane, population density, land use, land ownership and accessibility. After taking these restrictions into account, we have singled out a strip of land in south central Indiana in which we have selected four potential sites worthy of further exploration. In three of the sites the geology, lithology, and depth below the surface are more than adequate for crypt purposes in two separate formations--the Maquoketa Shale of the Ordovician System and the New Albany Shale-Borden Group of the Upper Devonian-Mississippian Systems. The interval between the two is several hundred feet. The geology and associated features in the fourth site are undoubtedly similar to those in the first three. In all four selections a sizeable proportion of the land is in public ownership and the population density in the nonpublicly owned land is low. The geology, lithology, and position of the target formations have been projected into the sites in question from data provided by drill core records of the Indiana Geological Survey. Precise details would, of course, require exploratory drilling on the selected site

  13. Geologic report of the Maquoketa Shale, New Albany Shale, and Borden Group rocks in the Illinois Basin as potential solid waste repository sites

    Energy Technology Data Exchange (ETDEWEB)

    Droste, J.B.; Vitaliano, C.J.

    1976-06-01

    We have evaluated the Illinois Basin in order to select a ''target site'' for a possible solid nuclear waste repository. In the process we have been mindful of geology (particularly stratigraphy and lithology and structure), terrane, population density, land use, land ownership and accessibility. After taking these restrictions into account, we have singled out a strip of land in south central Indiana in which we have selected four potential sites worthy of further exploration. In three of the sites the geology, lithology, and depth below the surface are more than adequate for crypt purposes in two separate formations--the Maquoketa Shale of the Ordovician System and the New Albany Shale-Borden Group of the Upper Devonian-Mississippian Systems. The interval between the two is several hundred feet. The geology and associated features in the fourth site are undoubtedly similar to those in the first three. In all four selections a sizeable proportion of the land is in public ownership and the population density in the nonpublicly owned land is low. The geology, lithology, and position of the target formations have been projected into the sites in question from data provided by drill core records of the Indiana Geological Survey. Precise details would, of course, require exploratory drilling on the selected site.

  14. DQO Summary Report for 105-N/109-N Interim Safe Storage Project Waste Characterization

    International Nuclear Information System (INIS)

    The DQO summary report provides the results of the DQO process completed for waste characterization activities for the 105-N/109-N Reactor Interim Safe Storage Project including decommission, deactivate, decontaminate, and demolish activities for six associated buildings.

  15. DQO Summary Report for 105-N/109-N Interim Safe Storage Project Waste Characterization

    Energy Technology Data Exchange (ETDEWEB)

    T. A. Lee

    2005-09-15

    The DQO summary report provides the results of the DQO process completed for waste characterization activities for the 105-N/109-N Reactor Interim Safe Storage Project including decommission, deactivate, decontaminate, and demolish activities for six associated buildings.

  16. Kinetics and Deactivation in the Methanol Synthesis Reaction

    OpenAIRE

    Alam, Mahmud

    2011-01-01

    This study is highlighting the synthesis of methanol by using Cu-based ( ) catalyst and synthesis gas, which consists a mixture of CO, CO2, H2, N2 and CH4. The catalyst was prepared as per the procedure described by the ICI and characterised by performing X-ray diffraction and Nitrogen adsorption/desorption. Experiments were carried out for the methanol synthesis at 80 bar pressure as well as at 255ºC temperatures and found very good reproducibility. The deactivation of the prepared catalyst ...

  17. Properties of Deactivation Gating Currents in Shaker Channels

    OpenAIRE

    Lacroix, Jérôme J.; Labro, Alain J.; Bezanilla, Francisco

    2011-01-01

    The charge versus voltage relation of voltage-sensor domains shifts in the voltage axis depending on the initial voltage. Here we show that in nonconducting W434F Shaker K+ channels, a large portion of this charge-voltage shift is apparent due to a dramatic slowing of the deactivation gating currents, IgD (with τ up to 80 ms), which develops with a time course of ∼1.8 s. This slowing in IgD adds up to the slowing due to pore opening and is absent in the presence of 4-aminopyridine, a compound...

  18. Rupture loop annex ion exchange RLAIX vault deactivation

    Energy Technology Data Exchange (ETDEWEB)

    Ham, J.E.; Harris, D.L., Westinghouse Hanford

    1996-08-01

    This engineering report documents the deactivation, stabilization and final conditions of the Rupture Loop Annex Ion Exchange (RLAIX) Vault located northwest of the 309 Building`s Plutonium Recycle Test Reactor (PRTR). Twelve ion exchange columns, piping debris, and column liquid were removed from the vault, packaged and shipped for disposal. The vault walls and floor were decontaminated, and portions of the vault were painted to fix loose contamination. Process piping and drains were plugged, and the cover blocks and rain cover were installed. Upon closure,the vault was empty, stabilized, isolated.

  19. Epidemic Spread in Networks Induced by Deactivation Mechanism

    Institute of Scientific and Technical Information of China (English)

    YU Xiao-Ling; WU Xiao; ZHANG Duan-Ming; LI Zhi-Hao; LIANG Fang; WANG Xiao-Yu

    2008-01-01

    We have studied the topology and epidemic spreading behaviors on the networks in which deactivation mechanism and long-rang connection are coexisted. By means of numerical simulation, we find that the clustering coefficient C and the Pearson correlation coefficient r decrease with increasing long-range connection μ and the topological state of the network changes into that of BA model at the end (when μ = 1). For the Susceptible-Infect-Susceptible model of epidemics, the epidemic threshold can reach maximum value at μ = 0.4 and presents two different variable states around μ = 0.4.

  20. Dopaminergic Modulation of Medial Prefrontal Cortex Deactivation in Parkinson Depression

    Directory of Open Access Journals (Sweden)

    Anders H. Andersen

    2015-01-01

    Full Text Available Parkinson’s disease (PD is associated with emotional abnormalities. Dopaminergic medications ameliorate Parkinsonian motor symptoms, but less is known regarding the impact of dopaminergic agents on affective processing, particularly in depressed PD (dPD patients. The aim of this study was to examine the effects of dopaminergic pharmacotherapy on brain activation to emotional stimuli in depressed versus nondepressed Parkinson disease (ndPD patients. Participants included 18 ndPD patients (11 men, 7 women and 10 dPD patients (7 men, 3 women. Patients viewed photographs of emotional faces during functional MRI. Scans were performed while the patient was taking anti-Parkinson medication and the day after medication had been temporarily discontinued. Results indicate that dopaminergic medications have opposite effects in the prefrontal cortex depending upon depression status. DPD patients show greater deactivation in the ventromedial prefrontal cortex (VMPFC on dopaminergic medications than off, while ndPD patients show greater deactivation in this region off drugs. The VMPFC is in the default-mode network (DMN. DMN activity is negatively correlated with activity in brain systems used for external visual attention. Thus dopaminergic medications may promote increased attention to external visual stimuli among dPD patients but impede normal suppression of DMN activity during external stimulation among ndPD patients.

  1. Dopaminergic Modulation of Medial Prefrontal Cortex Deactivation in Parkinson Depression.

    Science.gov (United States)

    Andersen, Anders H; Smith, Charles D; Slevin, John T; Kryscio, Richard J; Martin, Catherine A; Schmitt, Frederick A; Blonder, Lee X

    2015-01-01

    Parkinson's disease (PD) is associated with emotional abnormalities. Dopaminergic medications ameliorate Parkinsonian motor symptoms, but less is known regarding the impact of dopaminergic agents on affective processing, particularly in depressed PD (dPD) patients. The aim of this study was to examine the effects of dopaminergic pharmacotherapy on brain activation to emotional stimuli in depressed versus nondepressed Parkinson disease (ndPD) patients. Participants included 18 ndPD patients (11 men, 7 women) and 10 dPD patients (7 men, 3 women). Patients viewed photographs of emotional faces during functional MRI. Scans were performed while the patient was taking anti-Parkinson medication and the day after medication had been temporarily discontinued. Results indicate that dopaminergic medications have opposite effects in the prefrontal cortex depending upon depression status. DPD patients show greater deactivation in the ventromedial prefrontal cortex (VMPFC) on dopaminergic medications than off, while ndPD patients show greater deactivation in this region off drugs. The VMPFC is in the default-mode network (DMN). DMN activity is negatively correlated with activity in brain systems used for external visual attention. Thus dopaminergic medications may promote increased attention to external visual stimuli among dPD patients but impede normal suppression of DMN activity during external stimulation among ndPD patients. PMID:26793404

  2. Routes for deactivation of different autothermal reforming catalysts

    Science.gov (United States)

    Pasel, Joachim; Wohlrab, Sebastian; Kreft, Stefanie; Rotov, Mikhail; Löhken, Katrin; Peters, Ralf; Stolten, Detlef

    2016-09-01

    Fuel cell systems with integrated autothermal reforming units require active and robust catalysts for H2 production. In pursuit of this, an experimental screening of catalysts utilized in the autothermal reforming of commercial diesel fuels is performed. The catalysts incorporate a monolithic cordierite substrate, an oxide support (γ-Al2O3, La-Al2O3, CeO2, Gd-CeO2, ZrO2, Y-ZrO2) and Rh as the active phase. Experiments are run by widely varying the O2/C and H2O/C molar ratios at different gas hourly space velocities. In most cases, this provokes accelerated catalyst deactivation and permits an informative comparison of the catalysts. Fresh and aged catalysts are characterized by temperature-programmed methods, thermogravimetry and transmission electron microscopy to find correlations with catalytic activity and stability. Using this approach, routes for catalyst deactivation are identified, together with causes of different catalytic activities. Suitable reaction conditions can be derived from our results for the operation of reactors for autothermal reforming at steady-state and under transient reaction conditions, which helps improve the efficiency and the stability of fuel cell systems.

  3. Diagnosis of deactivation sources for vanadium catalysts used in SO2 oxidation reaction and optimization of vanadium extraction from deactivated catalysts

    International Nuclear Information System (INIS)

    Physico-chemical analysis (X-ray, FTIR) and/or methanol oxidation reaction test were performed on fresh and deactivated vanadium catalysts used in H2SO4 manufacturing. It allowed the diagnosis of catalyst deactivation sources, as well as the processes of regenerating and recycling the worn out catalyst in converter. One of these processes is hydrometallurgical method. It consists in treating the deactivated catalyst with alkaline or acidic reagents and forming vanadate solution. A simple and non-costly operation of chemical attack permits the extraction of vanadium from silica in deactivated catalyst. The extracted vanadium can be used for the confection of regenerated catalysts or metallic tools. After optimization, this method can be used for industrial application

  4. Task-induced deactivation from rest extends beyond the default mode brain network.

    Directory of Open Access Journals (Sweden)

    Ben J Harrison

    Full Text Available Activity decreases, or deactivations, of midline and parietal cortical brain regions are routinely observed in human functional neuroimaging studies that compare periods of task-based cognitive performance with passive states, such as rest. It is now widely held that such task-induced deactivations index a highly organized 'default-mode network' (DMN: a large-scale brain system whose discovery has had broad implications in the study of human brain function and behavior. In this work, we show that common task-induced deactivations from rest also occur outside of the DMN as a function of increased task demand. Fifty healthy adult subjects performed two distinct functional magnetic resonance imaging tasks that were designed to reliably map deactivations from a resting baseline. As primary findings, increases in task demand consistently modulated the regional anatomy of DMN deactivation. At high levels of task demand, robust deactivation was observed in non-DMN regions, most notably, the posterior insular cortex. Deactivation of this region was directly implicated in a performance-based analysis of experienced task difficulty. Together, these findings suggest that task-induced deactivations from rest are not limited to the DMN and extend to brain regions typically associated with integrative sensory and interoceptive processes.

  5. Coke deactivation of catalysts for hydroprocessing of heavy petroleum feedstocks

    International Nuclear Information System (INIS)

    Harwell's principal contribution to the study of the role of coke in the deactivation of catalysts for hydroprocessing of heavy petroleum feedstocks has been the development and application of nuclear microprobe methods to measure the distributions of hydrogen, carbon, nitrogen and other elements in coked catalyst pellets. Nuclear microprobe methods have been developed that allow the measurement of the distribution of carbon, hydrogen, nitrogen and heavier elements in coked catalyst pellets. At present analysis by both deuteron and helium-4 ion beams is necessary to cover the complete range of elements. The potential of using helium-3 irradiation alone to measure all elements is as yet unrealised. Applications have included studies of the variability of profiles in batches of used pellets, investigation of interrelationships between coke components and limited kinetic studies. Many of these applications have proved to be successful and nuclear microprobe methods should continue to be exploited studies of catalyst coking. (au)

  6. Commercial experience with facility deactivation to safe storage

    Energy Technology Data Exchange (ETDEWEB)

    Sype, T.T. [Sandia National Labs., Albuquerque, NM (United States); Fischer, S.R. [Los Alamos National Lab., NM (United States); Lee, J.H. Jr.; Sanchez, L.C.; Ottinger, C.A.; Pirtle, G.J. [Sandia National Labs., Albuquerque, NM (United States)

    1995-09-01

    The Department of Energy (DOE) has shutdown many production reactors; the Department has begun a major effort to also shutdown a wide variety of other nuclear facilities. Because so many facilities are being closed, it is necessary to place many of them into a safe- storage status, i.e., deactivation, before conducting decommissioning- for perhaps as long as 20 years. The challenge is to achieve this safe-storage condition in a cost-effective manner while remaining in compliance with applicable regulations. The DOE Office of Environmental Management, Office of Transition and Management, commissioned a lessons-learned study of commercial experience with safe storage and decommissioning. Although the majority of the commercial experience has been with reactors, many of the lessons learned presented in this document can provide insight into transitioning challenges that Will be faced by the DOE weapons complex.

  7. Commercial experience with facility deactivation to safe storage

    International Nuclear Information System (INIS)

    The Department of Energy (DOE) has shutdown many production reactors; the Department has begun a major effort to also shutdown a wide variety of other nuclear facilities. Because so many facilities are being closed, it is necessary to place many of them into a safe- storage status, i.e., deactivation, before conducting decommissioning- for perhaps as long as 20 years. The challenge is to achieve this safe-storage condition in a cost-effective manner while remaining in compliance with applicable regulations. The DOE Office of Environmental Management, Office of Transition and Management, commissioned a lessons-learned study of commercial experience with safe storage and decommissioning. Although the majority of the commercial experience has been with reactors, many of the lessons learned presented in this document can provide insight into transitioning challenges that Will be faced by the DOE weapons complex

  8. Investigation and deactivation of B Plant HEPA filters

    International Nuclear Information System (INIS)

    This paper describes the integrated approach used to manage environmental, safety, and health considerations related to the B Plant canyon exhaust air filters at the US Department of Energy (DOE) Hanford Site. The narrative illustrates the development and implementation of integrated safety management as applied to a facility and its systems undergoing deactivation. During their lifetime, the high efficiency particulate air (HEPA) filters prevented the release of significant quantities of radioactive materials into the air. As the material in B Plant AVESF accumulated on the filters, it created an unusual situation. Over long periods of time, the radiation dose from the filter loading, combined with aging and chemical exposure actually degrade those filters which were intended to protect against any release to the environment

  9. Deactivation of Escherichia coli by the plasma needle

    International Nuclear Information System (INIS)

    In this paper we present a parameter study on deactivation of Escherichia coli (E. coli) by means of a non-thermal plasma (plasma needle). The plasma needle is a small-sized (1 mm) atmospheric glow sustained by radio-frequency excitation. This plasma will be used to disinfect heat-sensitive objects; one of the intended applications is in vivo deactivation of dental bacteria: destruction of plaque and treatment of caries. We use E. coli films plated on agar dishes as a model system to optimize the conditions for bacterial destruction. Plasma power, treatment time and needle-to-sample distance are varied. Plasma treatment of E. coli films results in formation of a bacteria-free void with a size up to 12 mm. 104-105 colony forming units are already destroyed after 10 s of treatment. Prolongation of treatment time and usage of high powers do not significantly improve the destruction efficiency: short exposure at low plasma power is sufficient. Furthermore, we study the effects of temperature increase on the survival of E. coli and compare it with thermal effects of the plasma. The population of E. coli heated in a warm water bath starts to decrease at temperatures above 40 deg. C. Sample temperature during plasma treatment has been monitored. The temperature can reach up to 60 deg. C at high plasma powers and short needle-to-sample distances. However, thermal effects cannot account for bacterial destruction at low power conditions. For safe and efficient in vivo disinfection, the sample temperature should be kept low. Thus, plasma power and treatment time should not exceed 150 mW and 60 s, respectively

  10. β-Arrestin-dependent deactivation of mouse melanopsin.

    Directory of Open Access Journals (Sweden)

    Evan G Cameron

    Full Text Available In mammals, the expression of the unusual visual pigment, melanopsin, is restricted to a small subset of intrinsically photosensitive retinal ganglion cells (ipRGCs, whose signaling regulate numerous non-visual functions including sleep, circadian photoentrainment and pupillary constriction. IpRGCs exhibit attenuated electrical responses following sequential and prolonged light exposures indicative of an adaptational response. The molecular mechanisms underlying deactivation and adaptation in ipRGCs however, have yet to be fully elucidated. The role of melanopsin phosphorylation and β-arrestin binding in this adaptive process is suggested by the phosphorylation-dependent reduction of melanopsin signaling in vitro and the ubiquitous expression of β-arrestin in the retina. These observations, along with the conspicuous absence of visual arrestin in ipRGCs, suggest that a β-arrestin terminates melanopsin signaling. Here, we describe a light- and phosphorylation- dependent reduction in melanopsin signaling mediated by both β-arrestin 1 and β-arrestin 2. Using an in vitro calcium imaging assay, we demonstrate that increasing the cellular concentration of β-arrestin 1 and β-arrestin 2 significantly increases the rate of deactivation of light-activated melanopsin in HEK293 cells. Furthermore, we show that this response is dependent on melanopsin carboxyl-tail phosphorylation. Crosslinking and co-immunoprecipitation experiments confirm β-arrestin 1 and β-arrestin 2 bind to melanopsin in a light- and phosphorylation- dependent manner. These data are further supported by proximity ligation assays (PLA, which demonstrate a melanopsin/β-arrestin interaction in HEK293 cells and ipRGCs. Together, these results suggest that melanopsin signaling is terminated in a light- and phosphorylation-dependent manner through the binding of a β-arrestin within the retina.

  11. DMPD: Toll receptors, CD14, and macrophage activation and deactivation by LPS. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 12106783 Toll receptors, CD14, and macrophage activation and deactivation by LPS. D...ceptors, CD14, and macrophage activation and deactivation by LPS. PubmedID 12106783 Title Toll receptors, CD14, and macrophage activa...tion and deactivation by LPS. Authors Dobrovolskaia MA,

  12. Geology and geohydrology of the Palo Duro Basin, Texas Panhandle. Report on the progress of nuclear waste isolation feasibility studies, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Dutton, S. P.; Finley, R. J.; Galloway, W. E.; Gustavson, T. C.; Handford, C. R.; Presley, M. W.

    1979-01-01

    Early in 1977 the Bureau of Economic Geology was invited to assemble and evaluate geologic data on several salt-bearing basins within the State of Texas as a contribution to the national nuclear repository program. In response to this request, the Bureau, acting as a technical research unit of the University of Texas at Austin and the State of Texas, initiated a long-term program to assemble and interpret all geologic and hydrologic information necessary for delineation, description, and evaluation of salt-bearing strata in the Panhandle area. The technical program can be subdivided into three broad research tasks, which are addressed by a basin analysis group, a surface studies group, and a basin geohydrology group. The basin analysis group has assembled the regional stratigraphic and structural framework of the total basin fill, initiated evaluation of natural resources, and selected stratigraphic core sites for sampling the salt and associated beds. Two drilling sites have provided nearly 8000 feet (2400 m) of core material for analysis and testing of the various lithologies overlying and interbedded with salt units. Concurrently, the surface studies group has collected ground and remotely-sensed data to describe surficial processes, including carbonate and evaporate solution, geomorphic evolution, and fracture system development. The newly formed basin geohydrology group will evaluate both shallow and deep circulation of fluids within the basins. This paper, a summary report of progress, reviews principal conclusions and illustrates the methodologies used and the types of data and displays generated.

  13. Geology and geohydrology of the Palo Duro Basin, Texas Panhandle. Report on the progress of nuclear waste isolation feasibility studies, 1978

    International Nuclear Information System (INIS)

    Early in 1977 the Bureau of Economic Geology was invited to assemble and evaluate geologic data on several salt-bearing basins within the State of Texas as a contribution to the national nuclear repository program. In response to this request, the Bureau, acting as a technical research unit of the University of Texas at Austin and the State of Texas, initiated a long-term program to assemble and interpret all geologic and hydrologic information necessary for delineation, description, and evaluation of salt-bearing strata in the Panhandle area. The technical program can be subdivided into three broad research tasks, which are addressed by a basin analysis group, a surface studies group, and a basin geohydrology group. The basin analysis group has assembled the regional stratigraphic and structural framework of the total basin fill, initiated evaluation of natural resources, and selected stratigraphic core sites for sampling the salt and associated beds. Two drilling sites have provided nearly 8000 feet (2400 m) of core material for analysis and testing of the various lithologies overlying and interbedded with salt units. Concurrently, the surface studies group has collected ground and remotely-sensed data to describe surficial processes, including carbonate and evaporate solution, geomorphic evolution, and fracture system development. The newly formed basin geohydrology group will evaluate both shallow and deep circulation of fluids within the basins. This paper, a summary report of progress, reviews principal conclusions and illustrates the methodologies used and the types of data and displays generated

  14. Deactivation and Regeneration of Commercial Type Fischer-Tropsch Co-Catalysts—A Mini-Review

    Directory of Open Access Journals (Sweden)

    Erling Rytter

    2015-03-01

    Full Text Available Deactivation of commercially relevant cobalt catalysts for Low Temperature Fischer-Tropsch (LTFT synthesis is discussed with a focus on the two main long-term deactivation mechanisms proposed: Carbon deposits covering the catalytic surface and re-oxidation of the cobalt metal. There is a great variety in commercial, demonstration or pilot LTFT operations in terms of reactor systems employed, catalyst formulations and process conditions. Lack of sufficient data makes it difficult to correlate the deactivation mechanism with the actual process and catalyst design. It is well known that long term catalyst deactivation is sensitive to the conditions the actual catalyst experiences in the reactor. Therefore, great care should be taken during start-up, shutdown and upsets to monitor and control process variables such as reactant concentrations, pressure and temperature which greatly affect deactivation mechanism and rate. Nevertheless, evidence so far shows that carbon deposition is the main long-term deactivation mechanism for most LTFT operations. It is intriguing that some reports indicate a low deactivation rate for multi-channel micro-reactors. In situ rejuvenation and regeneration of Co catalysts are economically necessary for extending their life to several years. The review covers information from open sources, but with a particular focus on patent literature.

  15. Deactivation kinetics of yeast alcohol dehydrogenase in aerosol OT/isooctane reverse micelles

    Energy Technology Data Exchange (ETDEWEB)

    Chen, D.; Chen, H.; Huang, T. [National Cheng Kung University, Tainan (Taiwan, Province of China)

    1995-10-10

    The deactivation kinetics of yeast alcohol dehydrogenase (YADH) in both aerosol OT/isooctane reverse micelles and aqueous buffer were studied. The YADH entrapped in reverse micelles could retain activity for above 24 hr although it was less stable than dissolved in aqueous buffer. Both the activity-time curves for the YADH in reverse micelles and in aqueous buffer exhibited a rather rapid exponential decay within the early 2 hr, followed by a slower exponential decay during the remaining period. A series-type enzyme deactivation model involving two first-order steps and one active intermediate was used to describe the deactivation behavior of YADH. The kinetic parameters of the deactivation rate equations were obtained by optimization method. In aqueous buffer, the deactivation rate of YADH exhibited a maximum around a Tris concentration of 0.1 mol{center_dot}m{sup -3}. The deactivation rate of YADH in reverse micelles was strongly dependent on Tris concentration and the molar ratio of water to surfactant ({omega}0). The residual activity percentage of the active intermediate increased with the increase of {omega}0 and Tris concentration, while both the rate constants for the first and second first-order deactivation steps decreased with the increase of Tris concentration. 30 refs., 2 figs., 2 tabs.

  16. Development of new deactivation method for simulation of fluid catalytic cracking equilibrium catalyst

    Indian Academy of Sciences (India)

    T Chiranjeevi; D T Gokak; V Ravikumar; P S Viswanathan

    2014-03-01

    Selection of a good catalyst is the easiest way to increase profitability of a fluid catalytic cracking (FCC) unit. During operation, these catalysts get deactivated due to operation at high temperatures, steam and deposition of metals on the catalyst. Developing a proper catalyst deactivation method is crucial for optimization of a good catalyst for FCC. Conventional laboratory deactivation procedures include direct metal impregnation method, cyclic deactivation method (CDM) and cyclic propylene steaming (CPS). Direct metal impregnation method gives higher coke and gas yields. CDM and CPS methods implementation is very difficult and time-consuming and there is a deviation in coke and gas yield. New rapid deactivation method has been developed to simulate plant equilibrium catalyst (E-Cat) by modifying metal impregnation, steaming and oxidation/reduction procedures. The E-Cat generated through a new deactivation method was characterized for physico-chemical properties using X ray diffraction (XRD), temperature-programmed reduction (TPR), and SEM-EDX and activity studies. XRD studies show that metals are dispersed well on catalyst samples. SEMEDX studies reveal that the morphology of simulated E-Cat and plant E-Cat catalyst particles appear to be same. E-Cat obtained by new deactivationmethod gives better coke and gas yields. Two E-Cats were also generated through CDM and direct metal impregnation method for comparing with the one generated through new method. New deactivation method also significantly reduces the evaluation time.

  17. Characterization of deactivated catalytic cracking catalyst and evaluation as absorbent material; Caracterizacao de catalisador de craqueamento catalitico desativado e avaliacao como material adsorvente

    Energy Technology Data Exchange (ETDEWEB)

    Valt, R.B.G.; Kaminari, N.M.S.; Cordeiro, B.; Ponte, M.J.J.S.; Ponte, H.A. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil)

    2010-07-01

    One of the main uses of catalysts in the petroleum industry is in step catalytic cracking, which after use and regeneration cycles generates large quantities of waste material. In this research the deactivated FCC catalyst was characterized before and after the electrokinetic remediation process, in order to assess the change of its structure and possible adsorptive capacity. Analyses of X-Ray Fluorescence Spectroscopy, Scanning Electron Microscopy and BET surface area measurement were performed. The analysis showed no structural change due to the process employed and that electrokinetic remediation has recovered 42% of adsorption capacity of the material, by removing about 89% of heavy metals adhered initially in the catalyst surface. (author)

  18. Deactivation mechanistic studies of copper chromite catalyst for selective hydrogenation of 2-furfuraldehyde

    OpenAIRE

    Liu, Dongxia; Zemlyanov, Dmitry; Win, Tianpin; Lobo-Lapidus, Rodrigo J.; Dumesic, James A.; Miller, Jeffrey T.; Marshall, Christopher L.

    2013-01-01

    Deactivation mechanisms of copper chromite (CuCr2O4 center dot CuO) catalyst for vapor-phase selective hydrogenation for furfuryl alcohol have been investigated using ex situ and in situ X-ray absorption fine structure (XAFS), X-ray photon spectroscopy (XPS), and Auger Electron Spectroscopy (AES). At 200 degrees C, the catalyst steadily deactivated. One of the dominant origins of catalyst deactivation is poisoning due to strong adsorption of polymeric species formed from the reactant and/or p...

  19. Mechanochemical approach for selective deactivation of external surface acidity of ZSM-5 zeolite catalyst.

    Science.gov (United States)

    Inagaki, Satoshi; Sato, Koki; Hayashi, Shunsuke; Tatami, Junichi; Kubota, Yoshihiro; Wakihara, Toru

    2015-03-01

    The acid sites associated with the external surface of zeolite particles are responsible for undesirable consecutive reactions, such as isomerization, alkylation, and oligomerization, resulting in a lower selectivity to a target product; therefore, the selective modification (deactivation) of the external surface of zeolite particles has been an important issue in zeolite science. Here, a new method for surface deactivation of zeolite catalyst was tested via a mechanochemical approach using powder composer. Postsynthetic mechanochemical treatment of ZSM-5 zeolite causes a selective deactivation of catalytically active sites existing only on the external surface, as a potentially useful catalyst for highly selective production of p-xylene. PMID:25654542

  20. Soot oxidation over NOx storage catalysts. Activity and deactivation

    International Nuclear Information System (INIS)

    Soot oxidation activity and deactivation of NOx storage and reduction (NSR) catalysts containing Pt, K, and Ba supported on Al2O3, are studied under a variety of reaction conditions. K-containing catalysts decrease soot oxidation temperature with O2 alone and the presence of Pt further enhance the activity due to synergetic effect. The active species responsible for synergism on Pt/K-Al2O3 are unstable and cannot be regenerated. Soot oxidation temperature decreases by about 150oC with NO+O2 exhaust feed gas and under lean conditions NSR system acts as catalysed soot filter (CSF). The reactions that are mainly responsible for decreasing soot oxidation temperature are: (1) soot oxidation with NO2 followed by NO recycles to NO2, and (2) soot oxidation with O2 assisted by NO2. Only a part of the stored NOx that is decomposed at high temperatures under lean conditions is found to be useful for soot oxidation. NOx storage capacity of NSR catalysts decreases upon ageing under soot oxidising conditions. This will lead to a decreased soot oxidation activity on stored nitrate decomposition. Pt/K-Al2O3 catalyst is more active, but least stable compared with Pt/Ba-Al2O3. (author)

  1. Helium POT System for Maintaining Sample Temperature after Cryocooler Deactivation

    Science.gov (United States)

    Haid, B. J.

    2006-04-01

    A system for maintaining a sample at a constant temperature below 10 K after deactivating the cooling source is demonstrated. In this system, the cooling source is a 4 K GM cryocooler that is joined with the sample through an extension that consists of a helium pot and a thermal resistance. Upon stopping the cryocooler, the power applied to a heater located on the sample side of the thermal resistance is decreased gradually to maintain an appropriate temperature rise across the thermal resistance as the helium pot warms. The sample temperature is held constant in this manner without the use of solid or liquid cryogens and without mechanically disconnecting the sample from the cooler. Shutting off the cryocooler significantly reduces sample motion that results from vibration and expansion/contraction of the cold-head housing. The reduction in motion permits certain procedures that are very sensitive to sample position stability, but are performed with limited duration. A proof-of-concept system was built and operated with the helium pot pressurized to the cryocooler's charge pressure. A sample with 200 mW of continuous heat dissipation was maintained at 7 K while the cryocooler operated intermittently with a duty cycle of 9.5 minutes off and 20 minutes on.

  2. Soluble inhibitors/deactivators of cellulase enzymes from lignocellulosic biomass.

    Science.gov (United States)

    Kim, Youngmi; Ximenes, Eduardo; Mosier, Nathan S; Ladisch, Michael R

    2011-04-01

    Liquid hot water, steam explosion, and dilute acid pretreatments of lignocellulose generate soluble inhibitors which hamper enzymatic hydrolysis as well as fermentation of sugars to ethanol. Toxic and inhibitory compounds will vary with pretreatment and include soluble sugars, furan derivatives (hydroxymethyl fulfural, furfural), organic acids (acetic, formic and, levulinic acid), and phenolic compounds. Their effect is seen when an increase in the concentration of pretreated biomass in a hydrolysis slurry results in decreased cellulose conversion, even though the ratio of enzyme to cellulose is kept constant. We used lignin-free cellulose, Solka Floc, combined with mixtures of soluble components released during pretreatment of wood, to prove that the decrease in the rate and extent of cellulose hydrolysis is due to a combination of enzyme inhibition and deactivation. The causative agents were extracted from wood pretreatment liquid using PEG surfactant, activated charcoal or ethyl acetate and then desorbed, recovered, and added back to a mixture of enzyme and cellulose. At enzyme loadings of either 1 or 25mg protein/g glucan, the most inhibitory components, later identified as phenolics, decreased the rate and extent of cellulose hydrolysis by half due to both inhibition and precipitation of the enzymes. Full enzyme activity occurred when the phenols were removed. Hence detoxification of pretreated woods through phenol removal is expected to reduce enzyme loadings, and therefore reduce enzyme costs, for a given level of cellulose conversion.

  3. Influence of mass transport towards deactivation in tert-butyl-source driven isobutane/2-butene alkylation

    Energy Technology Data Exchange (ETDEWEB)

    Aschauer, S.J.; Jess, A. [Bayreuth Univ. (Germany). Dept. of Chemical Engineering

    2011-07-01

    The deactivation of i-butane/trans-2-butene alkylation using tert-butyl-halide promoted ionic liquid catalysts is studied.Here, the mass transport was modified by varying the feed rate and the type of promoter addition. The experimental data show that the deactivation increases with increasing feed rate. Moreover, a biliquid foam is formed when feed rates above 1 g/min are adjusted. As the results indicate a strong influence of the biliquid foam and its formation on deactivation, both aspects are also discussed.When the promoter is added to the feed mixture an increase of conversion with time on stream is observed. A deactivation in continuous promoter addition mode could not be noted in the investigated time-on-stream range. (orig.)

  4. Origin of low temperature deactivation of Ni5Ga3 nanoparticles as catalyst for methanol synthesis

    DEFF Research Database (Denmark)

    Gardini, Diego; Sharafutdinov, Irek; Damsgaard, Christian Danvad;

    ] confirm dealloying as responsible for high temperature (T > 300 °C) deactivation, this does not explain the activity loss in the low temperature regime (T temperature (T = 200, 210, 250 °C) deactivation of silica supported Ni5Ga3 nanoparticles...... as catalyst for methanol production. Synthesis, followed by deactivation and a series of regeneration steps at increasing temperature in pure H2 has been carried out in a fixed-bed reactor connected to a gas chromatography system. In each regeneration step, CH4 is generated and the activity of the catalyst...... is subsequently increased, suggesting the presence of carbon containing species blocking the active sites of the alloy nanoparticles (Figure 1). Carbon deposition has furthermore been investigated by temperature programmed oxidation (TPO) of a deactivated catalyst in a fixed-bed reactor connected to a mass...

  5. Studies on Catalyst Deactivation Rate and Byproducts Yield during Conversion of Methanol to Olefins

    Institute of Scientific and Technical Information of China (English)

    Yan Dengchao; Munib Shahda; Weng Huixin

    2006-01-01

    The conversion of methanol to olefins (MTO) over the SAPO-34 catalyst in fixed-bed microreactor was studied. The effect of reaction temperatures for methanol conversion to olefins and byproducts was investigated. A temperature of 425 ℃ appeared to be the optimum one suitable for conversion of methanol to olefins. Since the presence of water could increase the olefins selectivity, the methanol conversion reactions with mixed water/methanol feed were also studied. The effect of weight hourly space velocity on conversion of methanol was also studied. The results indicated that the olefins selectivity was significantly increased as WHSV increased till approximately 7.69 h-1 then it began to level off. Different factors affecting the catalyst deactivation rate was studied, showing that the catalyst deactivation time was dependent on reaction conditions, and temperatures higher and lower than the optimal one made the catalyst deactivation faster.Adding water to methanol could slow down the catalyst deactivation rate.

  6. Patients' perspective on deactivation of the implantable cardioverter-defibrillator near the end of life

    DEFF Research Database (Denmark)

    Pedersen, Susanne S.; Chaitsing, Rismy; Szili-Torok, Tamas;

    2013-01-01

    for information; and the prevalence and correlates of a favorable attitude toward deactivation. Three cohorts of ICD patients (n = 440) extracted from our institutional database were asked to complete a survey that included a vignette about deactivation near the end of life. Of the 440 patients approached, 294......Recent guidelines have emphasized the importance of discussing the issue of deactivation near the end of life with patients with an implantable cardioverter-defibrillator (ICD). Few studies have examined the patient perspective and patients' wishes. We examined patients' knowledge and wishes...... (67%) completed the survey. Most patients (68%) were aware that it is possible to turn the ICD off, and 95% believed it is important to inform patients about the possibility. Of the patients completing the survey, 84% indicated a choice for or against deactivation. Psychological morbidity...

  7. Integrated Project Management Planning for the Deactivation of the Savannah River Site F-Canyon Complex

    Energy Technology Data Exchange (ETDEWEB)

    Clark, T.G.

    2000-12-01

    This paper explains the planning process that is being utilized by the Westinghouse Savannah River Company to take the F-Canyon Complex facilities from operations to a deactivated condition awaiting final decommissioning.

  8. Geology and geohydrology of the Palo Duro Basin, Texas Panhandle. Report on the progress of nuclear waste isolation feasibility studies, 1979

    International Nuclear Information System (INIS)

    Since early 1977, the Bureau of Economic Geology has been evaluating several salt-bearing basins within the State of Texas as part of the national nuclear repository program. The Bureau, a research unit of The University of Texas at Austin and the State of Texas, is carrying out a long-term program to gather and interpret all geologic and hydrologic information necessary for description, delineation, and evaluation of salt-bearing strata in the Palo Duro and Dalhart Basins of the Texas Panhandle. The program in FY 79 has been subdivided into four broad research tasks, which are addressed by a basin analysis group, a surface studies group, a geohydrology group, and a host-rock analysis group. The basin analysis group has delineated the structural and stratigraphic framework of the basins, initiated natural resource assessment, and integrated data from 8000 ft (2400 m) of core material into salt-stratigraphy models. Salt depth and thickness have been delineated for seven salt-bearing stratigraphic units. Concurrently, the surface studies group has collected ground and remotely sensed data to describe surficial processes, including salt solution, slope retreat/erosion mechanisms, geomorphic evolution, and fracture system development. The basin geohydrology group has begun evaluating both shallow and deep fluid circulation within the basins. The newly formed host-rock analysis group has initiated study of cores from two drilling sites for analysis of salt and the various lithologies overlying and interbedded with salt units. This paper, a summary report of progress in FY 79, presents principal conclusions and reviews methods used and types of data and maps generated

  9. Geology and geohydrology of the Palo Duro Basin, Texas Panhandle. Report on the progress of nuclear waste isolation feasibility studies, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Gustavson, T.C.; Presley, M.W.; Handford, C.R.; Finley, R.J.; Dutton, S.P.; Baumgardner, R.W. Jr.; McGillis, K.A.; Simpkins, W.W.

    1980-01-01

    Since early 1977, the Bureau of Economic Geology has been evaluating several salt-bearing basins within the State of Texas as part of the national nuclear repository program. The Bureau, a research unit of The University of Texas at Austin and the State of Texas, is carrying out a long-term program to gather and interpret all geologic and hydrologic information necessary for description, delineation, and evaluation of salt-bearing strata in the Palo Duro and Dalhart Basins of the Texas Panhandle. The program in FY 79 has been subdivided into four broad research tasks, which are addressed by a basin analysis group, a surface studies group, a geohydrology group, and a host-rock analysis group. The basin analysis group has delineated the structural and stratigraphic framework of the basins, initiated natural resource assessment, and integrated data from 8000 ft (2400 m) of core material into salt-stratigraphy models. Salt depth and thickness have been delineated for seven salt-bearing stratigraphic units. Concurrently, the surface studies group has collected ground and remotely sensed data to describe surficial processes, including salt solution, slope retreat/erosion mechanisms, geomorphic evolution, and fracture system development. The basin geohydrology group has begun evaluating both shallow and deep fluid circulation within the basins. The newly formed host-rock analysis group has initiated study of cores from two drilling sites for analysis of salt and the various lithologies overlying and interbedded with salt units. This paper, a summary report of progress in FY 79, presents principal conclusions and reviews methods used and types of data and maps generated.

  10. Selective Functionalization of Independently Addressed Microelectrodes by Electrochemical Activation and Deactivation of a Coupling Catalyst

    OpenAIRE

    Devaraj, Neal. K.; Dinolfo, Peter H.; Chidsey, Christopher E. D.; Collman, James P.

    2006-01-01

    We demonstrate selective functionalization of independently addressed microelectrodes by electrochemical activation and deactivation of a coupling catalyst. 1,2,3-Triazole formation between terminal acetylenes and organic azides is efficiently catalyzed by copper(I) complexes (a Sharpless “click” reaction) while the oxidized copper (II) complexes are inactive. By electrochemically activating or deactivating the catalyst by switching its redox state, we demonstrate control over triazole format...

  11. Deactivation and Regeneration of Commercial Type Fischer-Tropsch Co-Catalysts—A Mini-Review

    OpenAIRE

    Erling Rytter; Anders Holmen

    2015-01-01

    Deactivation of commercially relevant cobalt catalysts for Low Temperature Fischer-Tropsch (LTFT) synthesis is discussed with a focus on the two main long-term deactivation mechanisms proposed: Carbon deposits covering the catalytic surface and re-oxidation of the cobalt metal. There is a great variety in commercial, demonstration or pilot LTFT operations in terms of reactor systems employed, catalyst formulations and process conditions. Lack of sufficient data makes it difficult to correlat...

  12. On the Deactivation of Cobalt-based Fischer-Tropsch Catalysts

    OpenAIRE

    Cats, K.H.

    2016-01-01

    The Fischer-Tropsch Synthesis (FTS) process is an attractive way to obtain synthetic liquid fuel from alternative energy sources such as natural gas, coal or biomass. However, the deactivation of the catalyst, consisting of cobalt nanoparticles supported on TiO2, currently hampers the industrial application of the process. Despite many years of research, we still lack the fundamental insights into the mechanism of catalyst deactivation necessary to develop the next generation of FTS catalysts...

  13. Beyond catalyst deactivation: cross-metathesis involving olefins containing N-heteroaromatics

    OpenAIRE

    Kevin Lafaye; Cyril Bosset; Lionel Nicolas; Amandine Guérinot; Janine Cossy

    2015-01-01

    Alkenes containing N-heteroaromatics are known to be poor partners in cross-metathesis reactions, probably due to catalyst deactivation caused by the presence of a nitrogen atom. However, some examples of ring-closing and cross-metathesis involving alkenes that incorporate N-heteroaromatics can be found in the literature. In addition, recent mechanistic studies have focused on the rationalization of nitrogen-induced catalysts deactivation. The purpose of this mini-review is to give a brief ov...

  14. Deactivation of a Co-Precipitated Co/Al2O3 Catalyst

    OpenAIRE

    YILDIZ, Meltem; AKIN, Ayşe Nilgün

    2007-01-01

    The effects of reaction temperature, feed ratio, space time, and CO percentage in feed on the deactivation conditions of a co-precipitated 36 wt% Co/Al2O3 catalyst in CO hydrogenation were investigated. Environmental-SEM-EDX and temperature-programmed reduction (TPR) studies were performed on used catalysts to investigate the effect of reaction conditions on catalyst deactivation. Intensive coke deposition on the catalyst was observed at a reaction temperature of about 573 K. Increas...

  15. Catalyst Deactivation During n-Alkane Isomerization Studied by In Situ UV–vis–NIR Spectroscopy

    OpenAIRE

    Tzolova-Müller, G.; Chan Thaw, C.; Garin, F.; Jentoft, F.; Schlögl, R.

    2006-01-01

    In many industrial processes catalyst deactivation is caused by formation of carbonaceous deposits (“coke”) on the catalyst surface. Development of catalysts that are less prone to deactivation requires understanding the nature of the carbonaceous species and the formation routes. In situ spectroscopic methods could be very informative in this respect, as they give information about the state of the surface including adsorbates and allow correlations with catalytic performance. Sulfated zi...

  16. Deactivation of sulfonated hydrothermal carbons in the presence of alcohols: Evidences for sulfonic esters formation

    OpenAIRE

    Fraile, José M.; García Bordejé, E.; Roldán, Laura

    2012-01-01

    Sulfonated hydrothermal carbons present high activity for esterification of palmitic acid with alcohols. However, the catalyst is significantly deactivated upon recovery. Leaching of sulfonated species does not account for this deactivation, which is observed even by pretreatment only with the alcohol under reflux. Solid state NMR shows the presence of chemically bound alkyl groups coming from the alcohol, clearly different from strongly physisorbed species obtained by pretreatment at room te...

  17. Zeolite deactivation during hydrocarbon reactions: characterisation of coke precursors and acidity, product distribution

    OpenAIRE

    Wang, B.

    2008-01-01

    The catalytic conversion of hydrocarbons over zeolites has been applied in large scale petroleum-refining processes. However, there is always formation and retention of heavy by-products, called coke, which causes catalyst deactivation. This deactivation is due to the poisoning of the acid sites and/or pore blockage. The formation of coke on hydrocarbon processing catalysts is of considerable technological and economic importance and a great deal of work has been carried out to this study. Th...

  18. Differential Deactivation during Mentalizing and Classification of Autism Based on Default Mode Network Connectivity

    OpenAIRE

    Murdaugh, Donna L.; Shinkareva, Svetlana V.; Deshpande, Hrishikesh R.; Jing Wang; Pennick, Mark R; Kana, Rajesh K.

    2012-01-01

    The default mode network (DMN) is a collection of brain areas found to be consistently deactivated during task performance. Previous neuroimaging studies of resting state have revealed reduced task-related deactivation of this network in autism. We investigated the DMN in 13 high-functioning adults with autism spectrum disorders (ASD) and 14 typically developing control participants during three fMRI studies (two language tasks and a Theory-of-Mind (ToM) task). Each study had separate blocks ...

  19. Dopamine Transporters in Striatum Correlate with Deactivation in the Default Mode Network during Visuospatial Attention

    OpenAIRE

    Dardo Tomasi; Volkow, Nora D.; Ruiliang Wang; Frank Telang; Gene-Jack Wang; Linda Chang; Thomas Ernst; Fowler, Joanna S.

    2009-01-01

    BACKGROUND: Dopamine and dopamine transporters (DAT, which regulate extracellular dopamine in the brain) are implicated in the modulation of attention but their specific roles are not well understood. Here we hypothesized that dopamine modulates attention by facilitation of brain deactivation in the default mode network (DMN). Thus, higher striatal DAT levels, which would result in an enhanced clearance of dopamine and hence weaker dopamine signals, would be associated to lower deactivation i...

  20. Patient perceptions of implantable cardioverter-defibrillator deactivation discussions: A qualitative study

    Directory of Open Access Journals (Sweden)

    Jane MacIver

    2016-04-01

    Full Text Available Background: There is a class I recommendation for implantable cardioverter-defibrillator deactivation discussions to occur between physicians and heart failure patients. Few studies have reported the patient’s perspective on the timing of implantable cardioverter-defibrillator deactivation discussions. Aim: To determine patient awareness, preferences and timing of implantable cardioverter-defibrillator deactivation discussions. Design: Grounded theory was used to collect and analyze interview data from 25 heart failure patients with an implantable cardioverter-defibrillator. Setting and participants: Patients with an implantable cardioverter-defibrillator, from the Heart Function Clinic at University Health Network (Toronto, Canada. Results: The sample (n = 25 was predominately male (76% with an average age of 62 years. Patients identified three stages where they felt implantable cardioverter-defibrillator deactivation should be discussed: (1 prior to implantation, (2 with any significant deterioration but while they were of sound mind to engage in and communicate their preferences and (3 at end of life, where patients wished further review of their previously established preferences and decisions about implantable cardioverter-defibrillator deactivation. Most patients (n = 17, 68% said they would consider deactivation, six (24% were undecided and two (8% were adamant they would never turn it off. Conclusion: The patient preferences identified in this study support the need to include information on implantable cardioverter-defibrillator deactivation at implant, with change in clinical status and within broader discussions about end-of-life treatment preferences. Using this process to help patients determine and communicate their implantable cardioverter-defibrillator deactivation preferences may reduce the number of patients experiencing distressing implantable cardioverter-defibrillator shocks at end of life.

  1. Dopamine transporters in striatum correlate with deactivation in the default mode network during visuospatial attention.

    Directory of Open Access Journals (Sweden)

    Dardo Tomasi

    Full Text Available BACKGROUND: Dopamine and dopamine transporters (DAT, which regulate extracellular dopamine in the brain are implicated in the modulation of attention but their specific roles are not well understood. Here we hypothesized that dopamine modulates attention by facilitation of brain deactivation in the default mode network (DMN. Thus, higher striatal DAT levels, which would result in an enhanced clearance of dopamine and hence weaker dopamine signals, would be associated to lower deactivation in the DMN during an attention task. METHODOLOGY/PRINCIPAL FINDINGS: For this purpose we assessed the relationship between DAT in striatum (measured with positron emission tomography and [(11C]cocaine used as DAT radiotracer and brain activation and deactivation during a parametric visual attention task (measured with blood oxygenation level dependent functional magnetic resonance imaging in healthy controls. We show that DAT availability in caudate and putamen had a negative correlation with deactivation in ventral parietal regions of the DMN (precuneus, BA 7 and a positive correlation with deactivation in a small region in the ventral anterior cingulate gyrus (BA 24/32. With increasing attentional load, DAT in caudate showed a negative correlation with load-related deactivation increases in precuneus. CONCLUSIONS/SIGNIFICANCE: These findings provide evidence that dopamine transporters modulate neural activity in the DMN and anterior cingulate gyrus during visuospatial attention. Our findings suggest that dopamine modulates attention in part by regulating neuronal activity in posterior parietal cortex including precuneus (region involved in alertness and cingulate gyrus (region deactivated in proportion to emotional interference. These findings suggest that the beneficial effects of stimulant medications (increase dopamine by blocking DAT in inattention reflect in part their ability to facilitate the deactivation of the DMN.

  2. Dopamine Transporters in Striatum Correlated with Deactivation in the Default Mode Network during Visuospatial Attention

    Energy Technology Data Exchange (ETDEWEB)

    Tomasi, D.; Fowler, J.; Tomasi, D.; Volkow, N.D.; Wang, R.L.; Telang, F.; Wang, Chang, L.; Ernst, T.; /Fowler, J.S.

    2009-06-01

    Dopamine and dopamine transporters (DAT, which regulate extracellular dopamine in the brain) are implicated in the modulation of attention but their specific roles are not well understood. Here we hypothesized that dopamine modulates attention by facilitation of brain deactivation in the default mode network (DMN). Thus, higher striatal DAT levels, which would result in an enhanced clearance of dopamine and hence weaker dopamine signals, would be associated to lower deactivation in the DMN during an attention task. For this purpose we assessed the relationship between DAT in striatum (measured with positron emission tomography and [{sup 11}C]cocaine used as DAT radiotracer) and brain activation and deactivation during a parametric visual attention task (measured with blood oxygenation level dependent functional magnetic resonance imaging) in healthy controls. We show that DAT availability in caudate and putamen had a negative correlation with deactivation in ventral parietal regions of the DMN (precuneus, BA 7) and a positive correlation with deactivation in a small region in the ventral anterior cingulate gyrus (BA 24/32). With increasing attentional load, DAT in caudate showed a negative correlation with load-related deactivation increases in precuneus. These findings provide evidence that dopamine transporters modulate neural activity in the DMN and anterior cingulate gyrus during visuospatial attention. Our findings suggest that dopamine modulates attention in part by regulating neuronal activity in posterior parietal cortex including precuneus (region involved in alertness) and cingulate gyrus (region deactivated in proportion to emotional interference). These findings suggest that the beneficial effects of stimulant medications (increase dopamine by blocking DAT) in inattention reflect in part their ability to facilitate the deactivation of the DMN.

  3. Kinetic modeling of oxidative desulfurization and catalyst deactivation

    Energy Technology Data Exchange (ETDEWEB)

    Tam, P.S.W.

    1986-01-01

    An oxidative-desulfurization (ODS) process was used to remove sulfur from diesel oils. The oxidants used were nitrogen dioxide and nitric acid. The feedstock under investigation was Atmospheric Gas Oil (AGO). Extraction of the oxidized oil with el-butyrolactone was used to remove additional sulfur from the oil. For a given solvent-to-oil (S/O) ratio, the extraction results from oxidized AGO showed higher sulfur removal than from the unoxidized oil. The ODS reactions are chain, free radical, auto-catalytic polymerization reactions similar to those in the sediment formation in fuel oil upon storage. Removal of sulfur by oxidation is from the deposition of co-product (residue) with high sulfur content. Increasing the oxidant concentration leads to increased residue formation, resulting in greater sulfur removal. A mathematical kinetic model is presented to describe the kinetics of sulfur removal in the oxidation of AGO using a CSTR. This model employs lumping of the sulfur compounds in the oil into three groups, according to their retention times in the gas chromatograph. Sulfur and nitrogen compounds usually poison catalysts in hydrocarbon processing. Models were developed to predict the cracking rate and catalyst activity in the cracking of cumene in the presence of organic nitrogen-containing poisons. A new mathematical definition of catalyst activity was used, including the adsorbed poison on active sites. Experimental data were used to fit the derived models, with excellent results. Finally, the use of exponential integral techniques to solve, analytically, the band-aging catalyst deactivation problem in an adiabatic fixed bed reactor is presented.

  4. Sampling and Analysis Plan for the 105-N Basin Water

    Energy Technology Data Exchange (ETDEWEB)

    R.O. Mahood

    1997-12-31

    This sampling and analysis plan defines the strategy, and field and laboratory methods that will be used to characterize 105-N Basin water. The water will be shipped to the 200 Area Effluent Treatment Facility for treatment and disposal as part of N Reactor deactivation. These analyses are necessary to ensure that the water will meet the acceptance criteria of the ETF, as established in the Memorandum of Understanding for storage and treatment of water from N-Basin (Appendix A), and the characterization requirements for 100-N Area water provided in a letter from ETF personnel (Appendix B)

  5. Deactivation of Ni2P/SiO2 catalyst in hydrodechlorination of chlorobenzene

    International Nuclear Information System (INIS)

    Highlights: • Ni2P/SiO2 has higher performance than Ni/SiO2 for hydrodechlorination. • Ni2P has higher resistance to HCl poison and to sintering than Ni. • Ni2P/SiO2 deactivation is mainly attributed to carbonaceous deposit. • Ni/SiO2 deactivation is mostly due to HCl poison and Ni sintering. - Abstract: The deactivation of the Ni2P/SiO2 catalyst in the hydrodechlorination of chlorobenzene was studied. To better illuminate the reasons for the deactivation, the effect of HCl on the structure and activity of Ni2P/SiO2 was investigated. For comparison, the deactivation of the Ni/SiO2 catalyst was also involved. It was found that the Ni2P particles possessed good resistance to HCl poison and to sintering, which is ascribed to the electron-deficiency of Niδ+(0 < δ < 1) site in Ni2P. Acted as the Lewis and Brönsted acid site, the Niδ+ site and the P-OH group on Ni2P/SiO2 catalyzed the formation of the carbonaceous deposit that was difficultly eliminated by hydrogenation. The carbonaceous deposit covered the active sites and might also induce a decrease in the Ni2P crystallinity, subsequently leading to the Ni2P/SiO2 deactivation. Different from Ni2P/SiO2, Ni/SiO2 was mainly deactivated by the chlorine poison and the sintering of nickel crystallites

  6. Differential deactivation during mentalizing and classification of autism based on default mode network connectivity.

    Directory of Open Access Journals (Sweden)

    Donna L Murdaugh

    Full Text Available The default mode network (DMN is a collection of brain areas found to be consistently deactivated during task performance. Previous neuroimaging studies of resting state have revealed reduced task-related deactivation of this network in autism. We investigated the DMN in 13 high-functioning adults with autism spectrum disorders (ASD and 14 typically developing control participants during three fMRI studies (two language tasks and a Theory-of-Mind (ToM task. Each study had separate blocks of fixation/resting baseline. The data from the task blocks and fixation blocks were collated to examine deactivation and functional connectivity. Deficits in the deactivation of the DMN in individuals with ASD were specific only to the ToM task, with no group differences in deactivation during the language tasks or a combined language and self-other discrimination task. During rest blocks following the ToM task, the ASD group showed less deactivation than the control group in a number of DMN regions, including medial prefrontal cortex (MPFC, anterior cingulate cortex, and posterior cingulate gyrus/precuneus. In addition, we found weaker functional connectivity of the MPFC in individuals with ASD compared to controls. Furthermore, we were able to reliably classify participants into ASD or typically developing control groups based on both the whole-brain and seed-based connectivity patterns with accuracy up to 96.3%. These findings indicate that deactivation and connectivity of the DMN were altered in individuals with ASD. In addition, these findings suggest that the deficits in DMN connectivity could be a neural signature that can be used for classifying an individual as belonging to the ASD group.

  7. Resting-State Glutamate and GABA Concentrations Predict Task-Induced Deactivation in the Default Mode Network

    OpenAIRE

    Hu, Yuzheng; Chen, Xi; Gu, Hong; Yang, Yihong

    2013-01-01

    Deactivation of the human brain's default mode network (DMN) is regarded as suppression of endogenous activity to support exogenous task-related processes. This phenomenon has important functional relevance and insufficient DMN deactivation has been implicated in several neuropsychiatric disorders. However, the neurochemical mechanism of the DMN′s deactivation remains largely unknown. In the present study, we test the hypothesis that the major excitatory and inhibitory neurotransmitters, glut...

  8. Influence of catalyst deactivation on N2O emissions from automobiles

    International Nuclear Information System (INIS)

    Though estimates of the total N2O emitted by automobiles differ widely, automobiles are believed to be a significant source of non-agricultural anthropogenic N2O emissions. At the Third Conference of the Parties (COP-3) UN Framework Convention on Climate Change, held in Kyoto in 1997, N2O was designated as a greenhouse gas whose release into the atmosphere must be reduced. This action increased the need for more accurate estimates of automotive N2O emissions. The wide variation in estimates may be attributed to differences in emission test modes, types of catalysts, and levels of catalyst deactivation involved in the tests. In this study, we examined the influence of automotive catalyst deactivation on N2O emissions from the perspective of catalyst temperature frequency distribution. Using a model gas and deactivated three-way catalysts (TWCs), we applied the exhaust emission test modes of various countries. The results indicate that the factor behind the increase of N2O emissions following catalyst deactivation is not growth in N2O generation, but a decline in the N2O decomposition capability of the catalyst. It was also found that the effect of catalyst deactivation differs according to the catalyst composition and the emission test mode.(author)

  9. Remaining Sites Verification Package for the 100-D-50:5 Process Sewers (183-DR Sedimentation Basin Drains), Waste Site Reclassification Form 2006-025

    Energy Technology Data Exchange (ETDEWEB)

    L. M. Dittmer

    2007-11-06

    The 100-D-50:5 subsite encompasses the southern process sewers formerly servicing the 183-DR coagulation and sedimentation basins and proximate surface runoff collection drains. The results of confirmatory sampling of pipeline sediments and underlying soils at the 100-D-50:5 subsite demonstrated that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also showed that residual contaminant concentrations are protective of groundwater and the Columbia River.

  10. Remaining Sites Verification Package for the 100-D-50:5 Process Sewers (183-DR Sedimentation Basin Drains). Attachment to Waste Site Reclassification Form 2006-025

    International Nuclear Information System (INIS)

    The 100-D-50:5 subsite encompasses the southern process sewers formerly servicing the 183-DR coagulation and sedimentation basins and proximate surface runoff collection drains. The results of confirmatory sampling of pipeline sediments and underlying soils at the 100-D-50:5 subsite demonstrated that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also showed that residual contaminant concentrations are protective of groundwater and the Columbia River

  11. Work plan for the Isotopes Facilities Deactivation Project at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    The purpose of the Isotopes Facilities Deactivation Project (IFDP) is to place former isotopes production facilities at the Oak Ridge National Laboratory in a safe, stable, and environmentally sound condition; suitable for an extended period of minimum surveillance and maintenance (S ampersand M) and as quickly and economical as possible. Implementation and completion of the deactivation project will further reduce the risks to the environment and to public safety and health. Furthermore, completion of the project will result in significant S ampersand M cost savings in future years. The IFDP work plan defines the project schedule, the cost estimate, and the technical approach for the project. A companion document, the IFDP management plan, has been prepared to document the project objectives, define organizational relationships and responsibilities, and outline the management control systems to be employed in the management of the project. The project has adopted the strategy of deactivating the simple facilities first, to reduce the scope of the project and to gain experience before addressing more difficult facilities. A decision support system is being developed to identify the activities that best promote the project mission and result in the largest cost savings. This work plan will be reviewed and revised annually. Deactivation of IFDP facilities was initiated in FY 1994 and will be completed in FY 1999. The schedule for deactivation of facilities is shown. The total cost of the project is estimated to be $36M. The costs are summarized. Upon completion of deactivation, annual S ampersand M costs of these facilities will be reduced from the current level of $5M per year to less than $1M per year

  12. Work plan for the Isotopes Facilities Deactivation Project at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-01

    The purpose of the Isotopes Facilities Deactivation Project (IFDP) is to place former isotopes production facilities at the Oak Ridge National Laboratory in a safe, stable, and environmentally sound condition; suitable for an extended period of minimum surveillance and maintenance (S and M) and as quickly and economical as possible. Implementation and completion of the deactivation project will further reduce the risks to the environment and to public safety and health. Furthermore, completion of the project will result in significant S and M cost savings in future years. The IFDP work plan defines the project schedule, the cost estimate, and the technical approach for the project. A companion document, the EFDP management plan, has been prepared to document the project objectives, define organizational relationships and responsibilities, and outline the management control systems to be employed in the management of the project. The project has adopted the strategy of deactivating the simple facilities first, to reduce the scope of the project and to gain experience before addressing more difficult facilities. A decision support system is being developed to identify the activities that best promote the project mission and result in the largest cost savings. This work plan will be reviewed and revised annually. Deactivation of EFDP Facilities was initiated in FY 1994 and will be completed in FY 2000. The schedule for deactivation of facilities is shown. The total cost of the project is estimated to be $51M. The costs are summarized. Upon completion of deactivation, annual S and M costs of these facilities will be reduced from the current level of $5M per year to less than $1M per year.

  13. Work plan for the Isotopes Facilities Deactivation Project at Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    The purpose of the Isotopes Facilities Deactivation Project (IFDP) is to place former isotopes production facilities at the Oak Ridge National Laboratory in a safe, stable, and environmentally sound condition; suitable for an extended period of minimum surveillance and maintenance (S&M) and as quickly and economical as possible. Implementation and completion of the deactivation project will further reduce the risks to the environment and to public safety and health. Furthermore, completion of the project will result in significant S&M cost savings in future years. The IFDP work plan defines the project schedule, the cost estimate, and the technical approach for the project. A companion document, the IFDP management plan, has been prepared to document the project objectives, define organizational relationships and responsibilities, and outline the management control systems to be employed in the management of the project. The project has adopted the strategy of deactivating the simple facilities first, to reduce the scope of the project and to gain experience before addressing more difficult facilities. A decision support system is being developed to identify the activities that best promote the project mission and result in the largest cost savings. This work plan will be reviewed and revised annually. Deactivation of IFDP facilities was initiated in FY 1994 and will be completed in FY 1999. The schedule for deactivation of facilities is shown. The total cost of the project is estimated to be $36M. The costs are summarized. Upon completion of deactivation, annual S&M costs of these facilities will be reduced from the current level of $5M per year to less than $1M per year.

  14. Work plan for the Isotopes Facilities Deactivation Project at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    The purpose of the Isotopes Facilities Deactivation Project (IFDP) is to place former isotopes production facilities at the Oak Ridge National Laboratory in a safe, stable, and environmentally sound condition; suitable for an extended period of minimum surveillance and maintenance (S and M) and as quickly and economical as possible. Implementation and completion of the deactivation project will further reduce the risks to the environment and to public safety and health. Furthermore, completion of the project will result in significant S and M cost savings in future years. The IFDP work plan defines the project schedule, the cost estimate, and the technical approach for the project. A companion document, the EFDP management plan, has been prepared to document the project objectives, define organizational relationships and responsibilities, and outline the management control systems to be employed in the management of the project. The project has adopted the strategy of deactivating the simple facilities first, to reduce the scope of the project and to gain experience before addressing more difficult facilities. A decision support system is being developed to identify the activities that best promote the project mission and result in the largest cost savings. This work plan will be reviewed and revised annually. Deactivation of EFDP Facilities was initiated in FY 1994 and will be completed in FY 2000. The schedule for deactivation of facilities is shown. The total cost of the project is estimated to be $51M. The costs are summarized. Upon completion of deactivation, annual S and M costs of these facilities will be reduced from the current level of $5M per year to less than $1M per year

  15. Beyond catalyst deactivation: cross-metathesis involving olefins containing N-heteroaromatics

    Directory of Open Access Journals (Sweden)

    Kevin Lafaye

    2015-11-01

    Full Text Available Alkenes containing N-heteroaromatics are known to be poor partners in cross-metathesis reactions, probably due to catalyst deactivation caused by the presence of a nitrogen atom. However, some examples of ring-closing and cross-metathesis involving alkenes that incorporate N-heteroaromatics can be found in the literature. In addition, recent mechanistic studies have focused on the rationalization of nitrogen-induced catalysts deactivation. The purpose of this mini-review is to give a brief overview of successful metathesis reactions involving olefins containing N-heteroaromatics in order to delineate some guidelines for the use of these challenging substrates in metathesis reactions.

  16. Kinetics and deactivation of the NO reduction by CO on Pt-supported catalysts

    OpenAIRE

    Frank, Brigitta; Renken, Albert

    1999-01-01

    Reaction kinetics and catalyst deactivation during the redn. of NO with CO on a 0.5%Pt-3.4%MoO3/a-Al2O3 catalyst were investigated. The reaction shows an ignition/quenching behavior. After ignition, the reaction kinetics (formation of N2 and N2O) obey the bimol. Langmuir-Hinshelwood equations, in accordance with a dissociative mechanism. A slow catalyst deactivation is obsd. under reductive conditions (pCO >> pNO). The proposed mechanism comprises the formation of electron-withdrawing isocyan...

  17. Beyond catalyst deactivation: cross-metathesis involving olefins containing N-heteroaromatics.

    Science.gov (United States)

    Lafaye, Kevin; Bosset, Cyril; Nicolas, Lionel; Guérinot, Amandine; Cossy, Janine

    2015-01-01

    Alkenes containing N-heteroaromatics are known to be poor partners in cross-metathesis reactions, probably due to catalyst deactivation caused by the presence of a nitrogen atom. However, some examples of ring-closing and cross-metathesis involving alkenes that incorporate N-heteroaromatics can be found in the literature. In addition, recent mechanistic studies have focused on the rationalization of nitrogen-induced catalysts deactivation. The purpose of this mini-review is to give a brief overview of successful metathesis reactions involving olefins containing N-heteroaromatics in order to delineate some guidelines for the use of these challenging substrates in metathesis reactions. PMID:26664645

  18. Growth of Aligned Carbon Nanotubes on Large Scale by Methane Decomposition with Deactivation Inhibitor

    Institute of Scientific and Technical Information of China (English)

    Hao Yu; Zhili Li; Cheng Zhang; Feng Peng; Hongjuan Wang

    2007-01-01

    The effects of additives containing iron or nickel during chemical vapor deposition (CVD) on the growth of carbon nanotubes (CNTs) by methane decomposition on Mo/MgO catalyst were investigated. Ferrocene and nickel nitrate were introduced as deactivation inhibitors by in-situ evaporation during CVD. The precisely controlled in-situ introduction of these inhibitors increased the surface renewal of catalyst, and therefore prevented the catalyst from deactivation. Using this method, aligned multi-walled CNTs with parallel mesopores can be produced on a large scale.

  19. Beyond catalyst deactivation: cross-metathesis involving olefins containing N-heteroaromatics

    Science.gov (United States)

    Lafaye, Kevin; Bosset, Cyril; Nicolas, Lionel

    2015-01-01

    Summary Alkenes containing N-heteroaromatics are known to be poor partners in cross-metathesis reactions, probably due to catalyst deactivation caused by the presence of a nitrogen atom. However, some examples of ring-closing and cross-metathesis involving alkenes that incorporate N-heteroaromatics can be found in the literature. In addition, recent mechanistic studies have focused on the rationalization of nitrogen-induced catalysts deactivation. The purpose of this mini-review is to give a brief overview of successful metathesis reactions involving olefins containing N-heteroaromatics in order to delineate some guidelines for the use of these challenging substrates in metathesis reactions. PMID:26664645

  20. Beyond catalyst deactivation: cross-metathesis involving olefins containing N-heteroaromatics.

    Science.gov (United States)

    Lafaye, Kevin; Bosset, Cyril; Nicolas, Lionel; Guérinot, Amandine; Cossy, Janine

    2015-01-01

    Alkenes containing N-heteroaromatics are known to be poor partners in cross-metathesis reactions, probably due to catalyst deactivation caused by the presence of a nitrogen atom. However, some examples of ring-closing and cross-metathesis involving alkenes that incorporate N-heteroaromatics can be found in the literature. In addition, recent mechanistic studies have focused on the rationalization of nitrogen-induced catalysts deactivation. The purpose of this mini-review is to give a brief overview of successful metathesis reactions involving olefins containing N-heteroaromatics in order to delineate some guidelines for the use of these challenging substrates in metathesis reactions.

  1. Deactivation and Coke Accumulation during CO2/CH4 Reforming over Pt Catalysts

    OpenAIRE

    Bitter, J.H.; Seshan, K.; Lercher, J.A.

    2001-01-01

    The Deactivation of Pt catalysts used in the generation of synthesis gas via CO2/CH4 reforming depends strongly on the support and the metalparticle size. Methods of Physicochemical characterization such as X-ray absorption spectroscopy and hydrogen chemisorption suggest that carbon formation (most likely from methane) rather than sintering is the main cause of catalyst deactivation. The rate of carbon formation decreased in the order Pt/y-Al2O3 >> Pt/TiO2 > Pt/ZrO2. Carbon was formed on the ...

  2. Metallization of oxide-ore-containing wastes with the use of brown coal semicoke from Berezovsky deposit of the Kansk- Achinsk Basin

    Science.gov (United States)

    Anikin, A. E.; Galevsky, G. V.; Nozdrin, E. V.; Rudneva, V. V.; Galevsky, S. G.

    2016-09-01

    The research of the metallization process of the roll scale and sludge after gas treatment in the BOF production with the use of brown coal semicoke mined in Berezovsky field of the Kansk-Achinsk Basin was carried out. A flow diagram of “cold” briquetting using a water-soluble binder was offered. The reduction of iron from its oxide Fe2O3 with brown coal semicoke in the laboratory electric-tube furnace in the argon atmosphere was studied. The mathematical models of dependence of the metallization degree on variable factors were developed. The optimal values of technological factors and essential characteristics of the obtained metallized products were revealed.

  3. Deactivation of the default mode network as a marker of impaired consciousness: an fMRI study.

    Directory of Open Access Journals (Sweden)

    Julia Sophia Crone

    Full Text Available Diagnosis of patients with a disorder of consciousness is very challenging. Previous studies investigating resting state networks demonstrate that 2 main features of the so-called default mode network (DMN, metabolism and functional connectivity, are impaired in patients with a disorder of consciousness. However, task-induced deactivation--a third main feature of the DMN--has not been explored in a group of patients. Deactivation of the DMN is supposed to reflect interruptions of introspective processes. Seventeen patients with unresponsive wakefulness syndrome (UWS, former vegetative state, 8 patients in minimally conscious state (MCS, and 25 healthy controls were investigated with functional magnetic resonance imaging during a passive sentence listening task. Results show that deactivation in medial regions is reduced in MCS and absent in UWS patients compared to healthy controls. Moreover, behavioral scores assessing the level of consciousness correlate with deactivation in patients. On single-subject level, all control subjects but only 2 patients in MCS and 6 with UWS exposed deactivation. Interestingly, all patients who deactivated during speech processing (except for one showed activation in left frontal regions which are associated with conscious processing. Our results indicate that deactivation of the DMN can be associated with the level of consciousness by selecting those who are able to interrupt ongoing introspective processes. In consequence, deactivation of the DMN may function as a marker of consciousness.

  4. GEOCHEMICAL MODELING OF F AREA SEEPAGE BASIN COMPOSITION AND VARIABILITY

    Energy Technology Data Exchange (ETDEWEB)

    Millings, M.; Denham, M.; Looney, B.

    2012-05-08

    From the 1950s through 1989, the F Area Seepage Basins at the Savannah River Site (SRS) received low level radioactive wastes resulting from processing nuclear materials. Discharges of process wastes to the F Area Seepage Basins followed by subsequent mixing processes within the basins and eventual infiltration into the subsurface resulted in contamination of the underlying vadose zone and downgradient groundwater. For simulating contaminant behavior and subsurface transport, a quantitative understanding of the interrelated discharge-mixing-infiltration system along with the resulting chemistry of fluids entering the subsurface is needed. An example of this need emerged as the F Area Seepage Basins was selected as a key case study demonstration site for the Advanced Simulation Capability for Environmental Management (ASCEM) Program. This modeling evaluation explored the importance of the wide variability in bulk wastewater chemistry as it propagated through the basins. The results are intended to generally improve and refine the conceptualization of infiltration of chemical wastes from seepage basins receiving variable waste streams and to specifically support the ASCEM case study model for the F Area Seepage Basins. Specific goals of this work included: (1) develop a technically-based 'charge-balanced' nominal source term chemistry for water infiltrating into the subsurface during basin operations, (2) estimate the nature of short term and long term variability in infiltrating water to support scenario development for uncertainty quantification (i.e., UQ analysis), (3) identify key geochemical factors that control overall basin water chemistry and the projected variability/stability, and (4) link wastewater chemistry to the subsurface based on monitoring well data. Results from this study provide data and understanding that can be used in further modeling efforts of the F Area groundwater plume. As identified in this study, key geochemical factors

  5. Final deactivation project report on the Integrated Process Demonstration Facility, Building 7602 Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    The purpose of this report is to document the condition of the Integrated Process Demonstration Facility (Building 7602) at Oak Ridge National Laboratory (ORNL) after completion of deactivation activities by the High Ranking Facilities Deactivation Project (HRFDP). This report identifies the activities conducted to place the facility in a safe and environmentally sound condition prior to transfer to the U.S. Department of Energy (DOE) Environmental Restoration EM-40 Program. This report provides a history and description of the facility prior to commencing deactivation activities and documents the condition of the building after completion of all deactivation activities. Turnover items, such as the Post-Deactivation Surveillance and Maintenance (S ampersand M) Plan, remaining hazardous and radioactive materials inventory, radiological controls, Safeguards and Security, and supporting documentation provided in the Office of Nuclear Material and Facility Stabilization Program (EM-60) Turnover package are discussed

  6. K Basins isolation barriers summary report

    Energy Technology Data Exchange (ETDEWEB)

    Strickland, G.C., Westinghouse Hanford

    1996-07-31

    The 105-K East and 105-K West fuel storage basins (105-K Basins) were designed and constructed in the early 1950`s for interim storage of irradiated fuel following its discharge from the reactors. The 105-K- East and 105-K West reactor buildings were constructed first, and the associated storage basins were added about a year later. The construction joint between each reactor building structure and the basin structure included a flexible membrane waterstop to prevent leakage. Water in the storage basins provided both radiation shielding and cooling to remove decay heat from stored fuel until its transfer to the Plutonium Uranium Extraction (PUREX) Facility for chemical processing. The 105-K West Reactor was permanently shut down in February 1970; the 105-K East Reactor was permanently shut down in February 1971. Except for a few loose pieces, fuel stored in the basins at that time was shipped to the PUREX Facility for processing. The basins were then left idle but were kept filled with water. The PUREX Facility was shut down and placed on wet standby in 1972 while N Reactor continued to operate. When the N Reactor fuel storage basin began to approach storage capacity, the decision was made to modify the fuel storage basins at 105-K East and 105-K West to provide additional storage capacity. Both basins were subsequently modified (105-K East in 1975 and 105-K West in 1981) to provide for the interim handling and storage of irradiated N Reactor fuel. The PUREX Facility was restarted in November 1983 to provide 1698 additional weapons-grade plutonium for the United States defense mission. The facility was shut down and deactivated in December 1992 when the U.S. Department of Energy (DOE) determined that the plant was no longer needed to support weapons-grade plutonium production. When the PUREX Facility was shut down, approximately 2.1 x 1 06 kg (2,100 metric tons) of irradiated fuel aged 7 to 23 years was left in storage in the 105-K Basins pending a decision on

  7. Equipment for radioactive waste treatment

    International Nuclear Information System (INIS)

    The equipment is used for the concentration, calcination, possibly denitration of high, medium and low level radioactive wastes. It is provided with a heated body and driving mechanism. In the heated body there is a horizontal or oblique shaft with a system of vanes, possibly with a screw. On one side of the heated body there is an opening for drop and vapour extraction. A lead screen may be placed in this area, opposite to it a shielding and between them a deactivation slot. The advantage of the discovery is in that the shaft including the bearings are placed outside of the working part of the equipment. (M.D.)

  8. DEACTIVATION OF H2S OF CR2O2 EMISSION CONTROL CATALYST FORCHLORINATED VOC DESTRUCTION

    Science.gov (United States)

    The paper discusses one aspect of catalyst stability (i.e.,deactivation by poisoning) and the concomitant effects on catalystactivity and selectivity in the destruction of chlorinatedhydrocarbons. he study was initiated because nothing isdocumented of the effect of H2S or the oth...

  9. Deactivation of Hydroprocessing Catalysts: New insights in catalyst structure, activity and stability

    NARCIS (Netherlands)

    Vogelaar, B.M.

    2005-01-01

    In dit proefschrift is de deactivering van hydroprocessing katalysatoren onderzocht. Katalysatoren zijn hulpstoffen die gebruikt worden om chemische reacties te bewerkstelligen, zonder daarbij zelf verbruikt te worden. Een bekend voorbeeld is de uitlaatkatalysator in de auto, die o.a. onverbrande br

  10. Self-related processing and deactivation of cortical midline regions in disorders of consciousness

    Directory of Open Access Journals (Sweden)

    Julia Sophia eCrone

    2013-08-01

    Full Text Available Self-related stimuli activate anterior parts of cortical midline regions, which normally show task-induced deactivation. Deactivation in medial posterior and frontal regions is associated with the ability to focus attention on the demands of the task, and therefore, with consciousness. Studies investigating patients with impaired consciousness, that is, patients in minimally conscious state and patients with unresponsive wakefulness syndrome (formerly vegetative state, demonstrate that these patients show responses to self-related content in the anterior cingulate cortex. However, it remains unclear if these responses are an indication for conscious processing of stimuli or are due to automatic processing. To shed further light on this issue, we investigated responses of cortical midline regions to the own and another name in 27 patients with a disorder of consciousness and compared them to task-induced deactivation. While almost all of the control subjects responding to the own name demonstrated higher activation due to the self-related content in anterior midline regions and additional deactivation, none of the responding patients did so. Differences between groups showed a similar pattern of findings. Despite the relation between behavioral responsiveness in patients and activation in response to the own name, the findings of this study do not provide evidence for a direct association of activation in anterior midline regions and conscious processing. The deficits in processing of self-referential content in anterior midline regions may rather be due to general impairments in cognitive processing and not particularly linked to impaired consciousness.

  11. A Treatment Study of Mode Deactivation Therapy in an Out Patient Community Setting

    Science.gov (United States)

    Apsche, Jack A.; Bass, Christopher K.; Siv, Alexander

    2006-01-01

    This paper is a review of the outpatient data and recidivism for an 18 month post treatment follow-up of Mode Deactivation Therapy (MDT). The follow up data suggests that effects of MDT generalized for over one-year post treatment in these adolescent conduct disordered males in an inpatient therapeutic setting. This research compared the…

  12. Chemical deactivation of Cu-SSZ-13 ammonia selective catalytic reduction (NH3-SCR) systems

    NARCIS (Netherlands)

    Lezcano-Gonzalez, I.; Deka, U.; van der Bij, H. E.; Paalanen, P.; Arstad, B.; Weckhuysen, B. M.; Beale, A. M.

    2014-01-01

    The chemical deactivation of Cu-SSZ-13 Ammonia Selective Catalytic Reduction (NH3-SCR) catalysts by Pt, Zn, Ca and P has been systematically investigated using a range of analytical techniques in order to study the influence on both the zeolitic framework and the active Cu2+ ions. The results obtain

  13. Innovative Work Practices and Lessons Learned at the N Area Deactivation Project

    International Nuclear Information System (INIS)

    This report identifies many of the lessons learned, innovations,and effective work practices that derived from activities supporting the N Area Deactivation Project at the U.S. Department of Energy's (DOE) Hanford Site. The work practices discussed in this report may be applicable and beneficial to similar projects throughout the DOE complex

  14. Deactivation of vanadia-based commercial SCR catalysts by polyphosphoric acids

    DEFF Research Database (Denmark)

    Castellino, Francesco; Rasmussen, Søren Birk; Jensen, Anker Degn;

    2008-01-01

    Commercial vanadia-based SCR monoliths have been exposed to flue gases in a pilot-scale Setup into which phosphoric acid has been added and the deactivation has been followed during the exposure time. Separate measurements by SMPS showed that the phosphoric acid formed polyphosphoric acid aerosols...

  15. Deactivation Correlations of Pd/Rh Three-way Catalysts Designed for Euro IV Emission Limits:effect of Ageing Atmosphere, Temperature and Time

    OpenAIRE

    Lassi, U. (Ulla)

    2003-01-01

    Abstract The aim of this thesis is the knowledge of the most relevant deactivation mechanisms of Pd/Rh three-way catalysts under different ageing conditions, the deactivation correlation of laboratory scale ageing and engine bench/vehicle ageings, and the evaluation of the deactivation correlation. In the literature review, the phenomena involved in the three-way catalyst operation and its deactivation are considered. In the experimental section, ageing-induced phenomena in the catalyst ar...

  16. Evaluation of the influence of muscle deactivation on other muscles and joints during gait motion.

    Science.gov (United States)

    Komura, Taku; Prokopow, Przemyslaw; Nagano, Akinori

    2004-04-01

    When any muscle in the human musculoskeletal system is damaged, other muscles and ligaments tend to compensate for the role of the damaged muscle by exerting extra effort. It is beneficial to clarify how the roles of the damaged muscles are compensated by other parts of the musculoskeletal system from the following points of view: From a clinical point of view, it will be possible to know how the abnormal muscle and joint forces caused by the acute compensations lead to further physical damage to the musculoskeletal system. From the viewpoint of rehabilitation, it will be possible to know how the role of the damaged muscle can be compensated by extra training of the other muscles. A method to evaluate the influence of muscle deactivation on other muscles and joints is proposed in this report. Methodology based on inverse dynamics and static optimization, which is applicable to arbitrary motion was used in this study. The evaluation method was applied to gait motion to obtain matrices representing (1) the dependence of muscle force compensation and (2) the change to bone-on-bone contact forces. These matrices make it possible to evaluate the effects of deactivation of one of the muscles of the musculoskeletal system on the forces exerted by other muscles as well as the change to the bone-on-bone forces when the musculoskeletal system is performing the same motion. Through observation of this matrix, it was found that deactivation of a muscle often results in increment/decrement of force developed by muscles with completely different primary functions and bone-on-bone contact force in different parts of the body. For example, deactivation of the iliopsoas leads to a large reduction in force by the soleus. The results suggest that acute deactivation of a muscle can result in damage to another part of the body. The results also suggest that the whole musculoskeletal system must go through extra retraining in the case of damage to certain muscles. PMID:14996554

  17. Working memory encoding and maintenance deficits in schizophrenia: neural evidence for activation and deactivation abnormalities.

    Science.gov (United States)

    Anticevic, Alan; Repovs, Grega; Barch, Deanna M

    2013-01-01

    Substantial evidence implicates working memory (WM) as a core deficit in schizophrenia (SCZ), purportedly due to primary deficits in dorsolateral prefrontal cortex functioning. Recent findings suggest that SCZ is also associated with abnormalities in suppression of certain regions during cognitive engagement--namely the default mode system--that may further contribute to WM pathology. However, no study has systematically examined activation and suppression abnormalities across both encoding and maintenance phases of WM in SCZ. Twenty-eight patients and 24 demographically matched healthy subjects underwent functional magnetic resonance imaging at 3T while performing a delayed match-to-sample WM task. Groups were accuracy matched to rule out performance effects. Encoding load was identical across subjects to facilitate comparisons across WM phases. We examined activation differences using an assumed model approach at the whole-brain level and within meta-analytically defined WM areas. Despite matched performance, we found regions showing less recruitment during encoding and maintenance for SCZ subjects. Furthermore, we identified 2 areas closely matching the default system, which SCZ subjects failed to deactivate across WM phases. Lastly, activation in prefrontal regions predicted the degree of deactivation for healthy but not SCZ subjects. Current results replicate and extend prefrontal recruitment abnormalities across WM phases in SCZ. Results also indicate deactivation abnormalities across WM phases, possibly due to inefficient prefrontal recruitment. Such regional deactivation may be critical for suppressing sources of interference during WM trace formation. Thus, deactivation deficits may constitute an additional source of impairments, which needs to be further characterized for a complete understanding of WM pathology in SCZ.

  18. Regeneration of commercial selective catalyst reduction catalysts deactivated by Pb and other inorganic elements.

    Science.gov (United States)

    Yu, Yanke; Wang, Jinxiu; Chen, Jinsheng; He, Xinjiang; Wang, Yujing; Song, Kai; Xie, Zongli

    2016-09-01

    The regeneration of commercial SCR (Selective Catalyst Reduction) catalysts deactivated by Pb and other elements was studied. The deactivated catalyst samples were prepared by chemical impregnation with mixed solution containing K2SO4, Na2SO4, CaSO4, Pb(NO3)2 and NH4H2PO4. A novel method combining Ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) and H2SO4 solution (viz. catalysts treated by dilute EDTA-2Na and H2SO4 solution in sequence) was used to recover the activity of deactivated samples, and the effect was compared with single H2SO4, oxalic acid, acetic acid, EDTA or HNO3 solutions. The surface structure, acidity and reducibility of samples were characterized by N2 adsorption-desorption, inductively coupled plasma optical emission spectrometer (ICP-OES), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray fluorescence (XRF), H2-temperature programmed section (H2-TPR), NH3-temperature programmed desorption (NH3-TPD) and in situ DRIFTS. Impurities caused a decrease of specific surface area and surface reducibility, as well as Brønsted acid sites, and therefore led to severe deactivation of the SCR catalyst. The use of an acid solution alone possibly eliminated the impurities on the deactivated catalyst to some extent, and also increased the specific surface area and Brønsted acid sites and promoted the surface reducibility, thus recovered the activity partially. The combination of EDTA-2Na and H2SO4 could remove most of the impurities and improve the activity significantly. The removal of Pb should be an important factor for regeneration. Due to a high removal rate for Pb and other impurities, the combination of EDTA-2Na and H2SO4 solutions provided the best efficiency. PMID:27593277

  19. Subproject plan for demonstration of 3M technology for treatment of N Basin water

    International Nuclear Information System (INIS)

    A dissolved radionuclides removal demonstration is being conducted at the 105-N Basin as part of the 100-N Area Projects' policy of aggressively integrating innovative technologies to achieve more cost effective, faster, and/or safer deactivation operations. This subproject plan demonstrates new technology (marketed by the 3M trademark Company) that absorbs specific ions from water. The demonstration will take place at the spent fuel basin at the N Reactor facility. The 105-N Basin contains 1 million gal of water consisting of approximately 32 Ci of dissolved 90Sr at a concentration of 8.4 uCi/L and 7.3 Ci of dissolved 137Cs at a concentration of 1.92 uCi/L. The Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement [Ecology et al. 1990]) Milestone M-16-01E-T2 requires the initiation of pretreatment and removal of all N Reactor fuel storage basin waters by September 30, 1996, pursuant to the N Reactor Deactivation Program Plan (WHC 1993). 105-N Basin dewatering is on the critical path for overall deactivation of N Reactor by March 1997. The 105-N Basin Deactivation Program Plan (BHI 1995) includes removing debris, hardware, algae and sediment from the basin, followed by pretreatment (filtration) and removal of the 1005-N Basin water. Final water removal is currently scheduled for September 30, 1996. The recommended method of the 105-N Basin water is the treatment of the water at the Effluent Treatment Facility (ETF) in the 200 East Area. The demonstration of the 3M technology could be a feasible treatment alternative to the ETF if the ETF is not available to meet the project schedule or if additional pretreatment is needed to reduce the inventory of radioactive species to be handled at the ETF. Demonstration of this technology could be of value for other fuel basins at the Hanford Site and possibly other US Department of Energy (DOE) sites and non- DOE nuclear power plants

  20. ASSESSMENT OF STRIPPABLE COATINGS FOR DEACTIVATION AND DECOMMISSIONING

    International Nuclear Information System (INIS)

    Strippable coatings are polymer mixtures, such as water-based organic polymers, that are applied to a surface by paintbrush, roller, or spray applicator. As the polymer reacts, it attracts, absorbs, and chemically binds the contaminants; then, during the curing process, it mechanically locks the contaminants into the polymer matrix. Incorporating fiber reinforcement (such as a cotton scrim) into the coating may enhance the strength of these coatings. Once the coating dries, it can be stripped manually from the surface, In the case of auto-release coatings, the mixture cracks, flakes, and is collected by vacuuming. The surface properties of these coatings may be modified by applying a thin top coat (e.g., polyvinyl alcohol), which may provide a smoother, less permeable surface that would become less severely contaminated. In such a duplex, the thicker basis layer provides the required mechanical properties (e.g., strength and abrasion resistance), while the top layer provides protection from contamination. Once the strippable coating is removed, the loose surface contamination is removed with the coating, producing a dry, hard, non-airborne waste product. The use of strippable coatings during D and D operations has proved a viable option. These coatings can be used in the following three functions: As a protective coating, when applied to an uncontaminated surface in an area where contamination is present, so that on its removal the surface remains uncontaminated; As a decontamination agent, when applied to a contaminated surface, so that on its removal a significant decontamination of loose particulate activity is achieved; and As a fixative or tie-down coating, when applied to a contaminated surface, so that any loose contamination is tied down, thus preventing the spread of contamination during subsequent handling

  1. ASSESSMENT OF STRIPPABLE COATINGS FOR DEACTIVATION AND DECOMMISSIONING

    Energy Technology Data Exchange (ETDEWEB)

    M.A. Ebadian, Ph.D.

    1999-01-01

    Strippable coatings are polymer mixtures, such as water-based organic polymers, that are applied to a surface by paintbrush, roller, or spray applicator. As the polymer reacts, it attracts, absorbs, and chemically binds the contaminants; then, during the curing process, it mechanically locks the contaminants into the polymer matrix. Incorporating fiber reinforcement (such as a cotton scrim) into the coating may enhance the strength of these coatings. Once the coating dries, it can be stripped manually from the surface, In the case of auto-release coatings, the mixture cracks, flakes, and is collected by vacuuming. The surface properties of these coatings may be modified by applying a thin top coat (e.g., polyvinyl alcohol), which may provide a smoother, less permeable surface that would become less severely contaminated. In such a duplex, the thicker basis layer provides the required mechanical properties (e.g., strength and abrasion resistance), while the top layer provides protection from contamination. Once the strippable coating is removed, the loose surface contamination is removed with the coating, producing a dry, hard, non-airborne waste product. The use of strippable coatings during D&D operations has proved a viable option. These coatings can be used in the following three functions: As a protective coating, when applied to an uncontaminated surface in an area where contamination is present, so that on its removal the surface remains uncontaminated; As a decontamination agent, when applied to a contaminated surface, so that on its removal a significant decontamination of loose particulate activity is achieved; and As a fixative or tie-down coating, when applied to a contaminated surface, so that any loose contamination is tied down, thus preventing the spread of contamination during subsequent handling.

  2. Study of rock-water-nuclear waste interactions in the Pasco Basin, Washington: Part II. Preliminary equilibrium-step simulations of basalt diagenesis

    International Nuclear Information System (INIS)

    Interactions between a large number of complex chemical and physical processes have resulted in significant changes in the Pasco Basin hydrochemical system since emplacement of the first basalt flow. In order to perform preliminary simulations of the chemical evolution of this system, certain simplifying assumptions and procedures were adopted and a computer model which operates on the principal of local equilibrium was used for the mass transfer calculations. Significant uncertainties exist in both the thermodynamic and reaction rate data which were input to the computer model. In addition, the compositional characteristics of the evolving hydrochemical system remain largely unknown, especially as a function of distance along the flow path. Given these uncertainties, it remains difficult to assess the applicability of the equilibrium-step approach even though reasonable matches between observed and simulated hydrochemical data were obtained. Given the uncertainties mentioned, the predictive abilities of EQ6 are difficult, if not impossible to evaluate; our simulations produced, at best, only qualitative agreement with observed product mineral assemblages and sequences, and fluid compositions

  3. Attempts to deactivate tannins in fodder shrubs with physical and chemical treatments

    International Nuclear Information System (INIS)

    Chopping, water sprinkling, storage under aerobic and anaerobic conditions, urea, wood ash, activated charcoal and polyethylene glycol 4000 (PEG) treatments were evaluated for their efficiency in deactivating tannins in shrub foliage. In a first trial, fresh leaves of Acacia cyanophylla Lindl. (acacia) were stored after chopping or without chopping and spraying or without spraying with water under aerobic or anaerobic conditions. The plant material was stored for 1, 7 and 14 days and analysed thereafter for extractable total phenols (TP), extractable total tannins (TT) and extractable condensed tannins (CT) contents. Chopping and water spraying substantially decreased the levels of TP, TT and CT of acacia. The rate of tannin deactivation increased in acacia stored under anaerobic conditions. Acacia stored for 7 days exhibited lower TP, TT and CT contents than that stored for only 1 day. Compared to the 7-day storage period, there was a further non-significant decrease in the level of these phenolic compounds when the storage duration was extended to 14 days. The highest level of rumen degradation of crude protein (CP) in sheep rumen was obtained with chopped, water sprinkled acacia leaves stored under anaerobic conditions. The second trial investigated the effect of increasing levels of urea (0, 20, 40, 60 and 80 g/kg) and treatment duration (7, 14, 21 and 28 days) on CP, TP, TT and CT in acacia leaves. The 20 g/kg urea level was sufficient to totally deactivate tannins in acacia even with the shortest storage period, i.e. 7 days. However, urea treatment increased ash-free neutral detergent fibre content and did not improve in sacco acacia degradation. In the third trial air-dried 1 mm ground samples of acacia and kermes oak (Quercus coccifera L.) leaves were added to water (control), acacia wood ash, activated charcoal or PEG solutions (100 g/kg) at 1:10 (w/v) and shaken for 20 min. All these four treatments decreased TP, TT and CT contents and could be classified

  4. Attempts to deactivate tannins in fodder shrubs with physical and chemical treatments

    Energy Technology Data Exchange (ETDEWEB)

    Ben Salem, H. [Institut National de la Recherche Agronomique de Tunisie, Laboratoire des Productions Animales et Fourrageres, Ariana (Tunisia)]. E-mail: bensalem.hichem@iresa.agrinet.tn; Saghrouni, L. [Institut National de la Recherche Agronomique de Tunisie, Laboratoire des Productions Animales et Fourrageres, Ariana (Tunisia); Ecole Superieure d' Agriculture de Mateur, Mateur (Tunisia); Nefzaoui, A. [Institut National de la Recherche Agronomique de Tunisie, Laboratoire des Productions Animales et Fourrageres, Ariana (Tunisia)

    2005-08-19

    Chopping, water sprinkling, storage under aerobic and anaerobic conditions, urea, wood ash, activated charcoal and polyethylene glycol 4000 (PEG) treatments were evaluated for their efficiency in deactivating tannins in shrub foliage. In a first trial, fresh leaves of Acacia cyanophylla Lindl. (acacia) were stored after chopping or without chopping and spraying or without spraying with water under aerobic or anaerobic conditions. The plant material was stored for 1, 7 and 14 days and analysed thereafter for extractable total phenols (TP), extractable total tannins (TT) and extractable condensed tannins (CT) contents. Chopping and water spraying substantially decreased the levels of TP, TT and CT of acacia. The rate of tannin deactivation increased in acacia stored under anaerobic conditions. Acacia stored for 7 days exhibited lower TP, TT and CT contents than that stored for only 1 day. Compared to the 7-day storage period, there was a further non-significant decrease in the level of these phenolic compounds when the storage duration was extended to 14 days. The highest level of rumen degradation of crude protein (CP) in sheep rumen was obtained with chopped, water sprinkled acacia leaves stored under anaerobic conditions. The second trial investigated the effect of increasing levels of urea (0, 20, 40, 60 and 80 g/kg) and treatment duration (7, 14, 21 and 28 days) on CP, TP, TT and CT in acacia leaves. The 20 g/kg urea level was sufficient to totally deactivate tannins in acacia even with the shortest storage period, i.e. 7 days. However, urea treatment increased ash-free neutral detergent fibre content and did not improve in sacco acacia degradation. In the third trial air-dried 1 mm ground samples of acacia and kermes oak (Quercus coccifera L.) leaves were added to water (control), acacia wood ash, activated charcoal or PEG solutions (100 g/kg) at 1:10 (w/v) and shaken for 20 min. All these four treatments decreased TP, TT and CT contents and could be classified

  5. Deactivation of hydrophobic Pt/SDBC-catalyst for H2/HTO-exchange reaction destined for tritium removal in reprocessing plant

    International Nuclear Information System (INIS)

    Deactivation of a hydrophobic Pt/SDBC catalyst for the H2/HTO isotopic exchange reaction used to remove tritium from the waste water generated in a nuclear-fuel reprocessing plant has been studied experimentally. The catalyst was poisoned reversibly by a small amount of HNO3 and could be regenerated by washing with water followed by drying in an inert gas. As a countermeasure against this poisoning, the neutralization of the waste water was found to be effective. The presence of I2 in the waste water caused a sharp decrease in the activity of the catalyst, due to the irreversible adsorption of I2 onto the catalyst surface. The I2 poisoning could be prevented by the conversion of I2 into I- or IO3- by neutralization or redox reaction. TBP and the neutral nitrate salts of fission products such as Sr(NO3)2 showed negligible poisoning effects on the catalyst. 10 refs., 8 figs., 1 tab

  6. Causes of Activation and Deactivation of Modified Nanogold Catalysts during Prolonged Storage and Redox Treatments.

    Science.gov (United States)

    Kolobova, Ekaterina; Kotolevich, Yulia; Pakrieva, Ekaterina; Mamontov, Grigory; Farías, Mario H; Bogdanchikova, Nina; Cortés Corberán, Vicente; Pestryakov, Alexey

    2016-01-01

    The catalytic properties of modified Au/TiO₂ catalysts for low-temperature CO oxidation are affected by deactivation and reactivation after long-term storage and by redox treatments. The effect of these phenomena on the catalysts was studied by HRTEM, BET, SEM, FTIR CO, XPS and H₂ TPR methods. The main cause for the deactivation and reactivation of catalytic properties is the variation in the electronic state of the supported gold, mainly, the proportion of singly charged ions Au⁺. The most active samples are those with the highest proportion of singly charged gold ions, while catalysts with a high content of trivalent gold ions are inactive at low-temperatures. Active states of gold, resistant to changes caused by the reaction process and storage conditions, can be stabilized by modification of the titanium oxide support with transition metals oxides. The catalyst modified with lanthanum oxide shows the highest stability and activity. PMID:27089310

  7. Using liquid desiccant as a regenerable filter for capturing and deactivating contaminants

    Science.gov (United States)

    Slayzak, Steven J.; Anderson, Ren S.; Judkoff, Ronald D.; Blake, Daniel M.; Vinzant, Todd B.; Ryan, Joseph P.

    2007-12-11

    A method, and systems for implementing such method, for purifying and conditioning air of weaponized contaminants. The method includes wetting a filter packing media with a salt-based liquid desiccant, such as water with a high concentration of lithium chloride. Air is passed through the wetted filter packing media and the contaminants in are captured with the liquid desiccant while the liquid desiccant dehumidifies the air. The captured contaminants are then deactivated in the liquid desiccant, which may include heating the liquid desiccant. The liquid desiccant is regenerated by applying heat to the liquid desiccant and then removing moisture. The method includes repeating the wetting with the regenerated liquid desiccant which provides a regenerable filtering process that captures and deactivates contaminants on an ongoing basis while also conditioning the air. The method may include filtration effectiveness enhancement by electrostatic or inertial means.

  8. The Deactivation of Nickel Hydroxide to Hypophosphite Electrooxidation on a Nickel Electrode

    Institute of Scientific and Technical Information of China (English)

    Yue ZENG; Min MO; Jian Long YI; Xin Jun TANG; Hui Xian WANG

    2004-01-01

    The deactivation of nickel hydroxide to the electrooxidation of hypophosphite on a nickel electrode was studied by means of in situ UV-Vis subtractive reflectance spectroscopy. The experimental results show that when the potential is lower than -1.0 V (SCE), the surface on nickel electrode is free of nickel hydroxide, on which hypophosphite is active. When the potential moves positively to about-0.75V, two absorbency bands around 300 nm and 550 nm, which were ascribed to the formation of α-nickel hydroxide, were observed, nickel is oxidized to α-nickel hydroxide.Severe deactivation of the surface occurs when the nickel surface is covered with nickel hydroxide,which separates the hypophosphite ion from nickel substrate.

  9. Causes of Activation and Deactivation of Modified Nanogold Catalysts during Prolonged Storage and Redox Treatments

    Directory of Open Access Journals (Sweden)

    Ekaterina Kolobova

    2016-04-01

    Full Text Available The catalytic properties of modified Au/TiO2 catalysts for low-temperature CO oxidation are affected by deactivation and reactivation after long-term storage and by redox treatments. The effect of these phenomena on the catalysts was studied by HRTEM, BET, SEM, FTIR CO, XPS and H2 TPR methods. The main cause for the deactivation and reactivation of catalytic properties is the variation in the electronic state of the supported gold, mainly, the proportion of singly charged ions Au+. The most active samples are those with the highest proportion of singly charged gold ions, while catalysts with a high content of trivalent gold ions are inactive at low-temperatures. Active states of gold, resistant to changes caused by the reaction process and storage conditions, can be stabilized by modification of the titanium oxide support with transition metals oxides. The catalyst modified with lanthanum oxide shows the highest stability and activity.

  10. Comparative investigations of zeolite catalyst deactivation by coking in the conversion of methanol to hydrocarbons

    OpenAIRE

    Evensen, Kjetil Gurholt

    2014-01-01

    With large countries as India and China in tremendous development accompanied by a growing worldwide population, questions arise in how energy demands can be met in the post-oil society. The methanol-to-hydrocarbon process, catalysed by Brønsted acidic zeolites, constitutes an alternative route for the production of gasoline and other valuable hydrocarbons from feedstocks such as natural gas and coal. Catalyst deactivation by coke formation is nevertheless a big concern, and a better understa...

  11. Platinum Deactivation: In Situ EXAFS Study During Aqueous Alcohol Oxidation Reaction

    OpenAIRE

    Koningsberger, D.C.; Ruitenbeek, M.; B.F.M. Kuster; Marin, G. B.

    1998-01-01

    With a new setup for in situ EXAFS spectroscopy the state of a carbonsupported platinum catalyst during aqueous alcohol oxidation has been observed. The catalyst deactivation during platinumcatalysed cyclohexanol oxidation is caused by platinum surface oxide formation. The detected Pt–O coordination at 2.10 Å during exposure to nitrogensaturated cyclohexanol solution is different from what is observed for the pure oxidised platinum surface (2.06 Å). platinum - EXAFS - catalysis - catalyst dea...

  12. Modelling, estimation and optimization of the methanol synthesis with catalyst deactivation

    OpenAIRE

    Løvik, Ingvild

    2001-01-01

    This thesis studies dynamic modelling, estimation and optimization of the methanol synthesis with catalyst deactivation. Conversion of natural gas is of special interest in Norway for both economic and political reasons. In June 1997 Statoil opened a methanol plant at Tjeldbergodden. It is among the largest in the word with a capacity of 830 000 metric tons per year, which equals 1/4 of Europe's capacity. Methanol is today mainly used as a building block to produce chemical intermediates, and...

  13. Deactivation of signal amplification by reversible exchange catalysis, progress towards in vivo application.

    Science.gov (United States)

    Mewis, Ryan E; Fekete, Marianna; Green, Gary G R; Whitwood, Adrian C; Duckett, Simon B

    2015-06-18

    The catalyst which is used in the signal amplification by reversible exchange (SABRE) process facilitates substrate hyperpolarisation while acting to speed up the rate of relaxation. Consequently, the lifetime over which the hyperpolarised contrast agent is visible is drastically reduced. We show that the addition of a chelating ligand, such as bipyridine, rapidly deactivates the SABRE catalyst thereby lengthening the agent's relaxation times and improving the potential of SABRE for diagnostic MRI. PMID:25989727

  14. In situ UV-vis-NIR Spectroscopy as a Tool to Understand Catalyst Deactivation

    OpenAIRE

    Chan Thaw, C.; Garin, F.; Tzolova-Müller, G.; Jentoft, F.; Schlögl, R.

    2006-01-01

    Introduction Catalyst deactivation is a frequently occurring problem, particularly in hydrocarbon conversion, and is often ascribed to the formation of “carbonaceous deposits”. Amount and nature of such deposits is usually determined by analysis of the spent catalyst after its removal from the reactor. In order to understand the formation and further transformation of surface species and to elucidate their effect on the catalytic performance, in situ measurements are compulsory. UV-vis-NIR...

  15. Atomic absorption determination of platinum and rhenium in deactivated catalysts based on γ-alumina

    International Nuclear Information System (INIS)

    A flame atomic absorption method has been developed for the determination of Pt and Re in deactivated catalysts based on γ-Al2O3. Hydrofluoric acid is used for catalyst dissolution. The lower determination limits are 1 μg/ml for Pt and 5 μg/ml for Re, RSD are 0.01-0.15 and 0.03-0.25 respectively

  16. Studying PW-Amberlite catalyst deactivation in limonene epoxidation by hydrogen peroxide

    OpenAIRE

    Rolando Barrera Zapata; Aída Luz Villa Holguín de P.; Consuelo Montes de Correa

    2010-01-01

    The PW-Amberlite catalyst is active for limonene epoxidation in triphasic conditions; it becomes deactivated in reaction condi- tions. Catalyst stability during the reaction and recovery of catalyst activity when it was treated with several solvents were evalua- ted. It was found that the catalyst recovered 99% of its initial activity when it was washed with toluene and that the recovery was 95% and 97% when ethanol or acetone were used as washing solvents, respectively. Leaching tests ...

  17. Effect Coke and Metal Deposition on Catalyst Deactivation of Early Stages of Resid Hydrodesulfurization Operation

    OpenAIRE

    出井, 一夫; 高橋, 武重; 甲斐, 敬美; IDEI, Kazuo; TAKAHASHI, Takeshige; KAI, Takami

    2001-01-01

    The hydrodesulfurization reaction with two kinds of atmospheric residues was carried out over three kinds of catalysts with different mean pore diameters to obtain catalysts with different deposited amounts of coke and metal on their surfaces. Elemental analysis and physical properties were carried out to elucidate the effects of coke and metal depositions on catalyst deactivation at an early stage of the reaction. Coke density (pc) and metal density (pm) calculated from the mean pore diamete...

  18. A study on the deactivation of USY zeolites with different rare earth contents

    Energy Technology Data Exchange (ETDEWEB)

    Henriques, C.A.; Santos, J.O.J. [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Quimica; Polato, C.M.S.; Valle, Murta; Aguiar, E.F.S. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Escola de Quimica; Monteiro, J.L.F. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Nucleo de Catalise

    1998-06-01

    The deactivation of USY zeolites different rare earth contents due to the coke formed n-heptane at 450 deg C was studied. The results show that the presence of rare earth elements decreases the cracking and coking activities, increasing catalytic stability. However, reaction selectivity was not significantly influenced. The greater the rare earth content, the lower the cocking rates and the coke contents. The TPO/DSC profiles suggested that the catalytic effect of the rare earth elements promoted coke oxidation. (author)

  19. Probing the Carboxyester Side Chain in Controlled Deactivation (−)-Δ8-Tetrahydrocannabinols

    OpenAIRE

    Nikas, Spyros P.; Sharma, Rishi; Paronis, Carol A.; Kulkarni, Shashank; Thakur, Ganesh A.; Hurst, Dow; Wood, JodiAnne T.; Gifford, Roger S.; Rajarshi, Girija; Liu, Yingpeng; Raghav, Jimit Girish; Guo, Jason Jianxin; Järbe, Torbjörn U.C.; Reggio, Patricia H.; Bergman, Jack

    2014-01-01

    We recently reported on a controlled deactivation/detoxification approach for obtaining cannabinoids with improved druggability. Our design incorporates a metabolically labile ester group at strategic positions within the THC structure. We have now synthesized a series of (−)-Δ8-THC analogues encompassing a carboxyester group within the 3-alkyl chain in an effort to explore this novel cannabinergic chemotype for CB receptor binding affinity, in vitro and in vivo potency and efficacy, as well ...

  20. Integrated project management plan for the Plutonium Finishing Plant stabilization and deactivation project

    International Nuclear Information System (INIS)

    This document sets forth the plans, organization, and control systems for managing the PFP Stabilization and Deactivation Project, and includes the top level cost and schedule baselines. The project includes the stabilization of Pu-bearing materials, storage, packaging, and transport of these and other nuclear materials, surveillance and maintenance of facilities and systems relied upon for storage of the materials, and transition of the facilities in the PFP Complex

  1. Investigation of cylinder deactivation and variable valve actuation on gasoline engine performance

    OpenAIRE

    Kuruppu, C; Pesiridis, A; Rajoo, S

    2014-01-01

    Increasingly stringent regulations on gasoline engine fuel consumption and exhaust emissions require additional technology integration such as Cylinder Deactivation (CDA) and Variable valve actuation (VVA) to improve part load engine efficiency. At part load, CDA is achieved by closing the inlet and exhaust valves and shutting off the fuel supply to a selected number of cylinders. Variable valve actuation (VVA) enables the cylinder gas exchange process to be optimised for different engine spe...

  2. Final Deactivation Project report on the Alpha Powder Facility, Building 3028, at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    This report documents the condition of the Alpha Powder Facility (APF), Building 3028, after completion of deactivation activities. Activities conducted to place the facility in a safe and environmentally sound condition for transfer to the U.S. Department of Energy (DOE) Office of Environmental Restoration (EM-40) program are outlined. A history and profile of the facility prior to commencing deactivation activities and a profile of the building after completion of deactivation activities are provided. Turnover items, such as the post-deactivation surveillance and maintenance (S&M) plan, remaining hazardous materials, radiological controls, safeguards and security, quality assurance, facility operations, and supporting documentation provided for in the DOE Nuclear Materials and Facility Stabilization Program (EM-60) turnover package are discussed.

  3. Tyrosine Residues from the S4-S5 Linker of Kv11.1 Channels Are Critical for Slow Deactivation.

    Science.gov (United States)

    Ng, Chai-Ann; Gravel, Andrée E; Perry, Matthew D; Arnold, Alexandre A; Marcotte, Isabelle; Vandenberg, Jamie I

    2016-08-12

    Slow deactivation of Kv11.1 channels is critical for its function in the heart. The S4-S5 linker, which joins the voltage sensor and pore domains, plays a critical role in this slow deactivation gating. Here, we use NMR spectroscopy to identify the membrane-bound surface of the S4S5 linker, and we show that two highly conserved tyrosine residues within the KCNH subfamily of channels are membrane-associated. Site-directed mutagenesis and electrophysiological analysis indicates that Tyr-542 interacts with both the pore domain and voltage sensor residues to stabilize activated conformations of the channel, whereas Tyr-545 contributes to the slow kinetics of deactivation by primarily stabilizing the transition state between the activated and closed states. Thus, the two tyrosine residues in the Kv11.1 S4S5 linker play critical but distinct roles in the slow deactivation phenotype, which is a hallmark of Kv11.1 channels.

  4. Study of the catalyst deactivation in an industrial gasoil HDS reactor using a mini-scale laboratory reactor

    Energy Technology Data Exchange (ETDEWEB)

    L.E. Kallinikos; G.D. Bellos; N.G. Papayannako [National Technical University of Athens, Athens (Greece). School of Chemical Engineering

    2008-09-15

    The activity of a hydrodesulphurization catalyst loaded in an industrial hydrotreater is studied at start up and end of run. Catalyst initial and final activity was determined by performing HDS experiments at industrial conditions in a laboratory mini-scale hydrotreater. The results show that the deactivation of the catalyst samples collected from three different places of the industrial reactor do not vary significantly, the maximum difference among the catalyst samples, being less than {+-}4%. The experimentally determined deactivation level of the catalyst samples is compared with the deactivation estimated for the same industrial reactor and the same load using a hybrid neural network model trained with operational data of the industrial and the results are in close agreement. Catalyst deactivation appears to be faster for hydrogen consumption reactions than for hydrodesulphurization reactions indicating a decreasing hydrogen consumption trend with time in operation for specific sulphur content in the product. 21 refs., 9 figs., 4 tabs.

  5. Incorporation of dynamic flexibility in the design of a methanol synthesis Loop in the presence of catalyst deactivation

    Energy Technology Data Exchange (ETDEWEB)

    Parvasi, P.; Rahimpour, M.R.; Jahanmiri, A. [Department of Chemical and Petroleum Engineering, Shiraz University (Iran)

    2008-01-15

    A typical methanol loop reactor is analyzed in this study. All basic equipment in the Lurgi-type methanol loop is included in the proposed model. A detailed dynamic model described by a set of ordinary differential and algebraic equations is developed to predict the behavior of the overall process. The model is validated against plant data. A new deactivation model is proposed and its parameters are estimated using daily plant data. The interesting feature of this model is that it incorporates the effect of carbon dioxide and carbon monoxide on the catalyst deactivation. Using the model, the effect of various factors to compensate for the reduction of production rate due to catalyst deactivation has been examined. Some improvements can be achieved by adjusting the operating conditions. Finally, a strategy is proposed for prevention of reduced production due to catalyst deactivation. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  6. Deactivation of a hydrophobic Pt/SDBC catalyst by nitrogen compounds for hydrogen isotopic exchange reaction

    International Nuclear Information System (INIS)

    In order to evaluate the deactivation of a hydrophobic Pt/SDBC catalyst used for a hydrogen isotopic exchange reaction, changes over time in the reaction rate of H2/HDO(v) isotopic exchange over the catalyst induced by the addition of nitric acid, nitrates and nitrogen oxides were studied experimentally. Deactivation was discussed in terms of the balance of the active sites. The catalyst was poisoned by HNO3 reversibly and the poisoning was well explained in terms of the competitive adsorption of HNO3 with H2 or HDO onto the catalytic active sites. The poisoning kinetics were explained by the Zeldovich rate equation. Neutral nitrates of fission products such as Sr(NO3)2 showed negligible poisoning effect on the catalyst. ZrO(NO3)2 showed very similar poisoning behavior with HNO3, and this was considered to result from hydrolysis reactions which produced HNO3. No deactivation was observed by the introduction of NO, NO2 or NH3 into the reactor. Instead of poisoning, the reaction rate was accelerated by NO or NO2 and this was considered to be due to local heating of the catalyst surface by exothermic reactions between nitrogen oxides and hydrogen. (author)

  7. Deactivation mechanism and feasible regeneration approaches for the used commercial NH3-SCR catalysts.

    Science.gov (United States)

    Yu, Yanke; Meng, Xiaoran; Chen, Jinsheng; Yin, Liqian; Qiu, Tianxue; He, Chi

    2016-01-01

    The deactivation and regeneration of selective catalytic reduction catalysts which have been used for about 37,000 h in a coal power plant are studied. The formation of Al2(SO4)3, surface deposition of K, Mg and Ca are primary reasons for the deactivation of the studied Selective catalytic reduction catalysts. Other factors such as activated V valence alteration also contribute to the deactivation. Reactivation of used catalysts via environment-friendly and finance-feasibly approaches, that is, dilute acid or alkali solution washing, would be of great interest. Three regeneration pathways were studied in the present work, and dilute nitric acid or sodium hydroxide solution could remove most of the contaminants over the catalyst surface and partly recover the catalytic performance. Notably, the acid-alkali combination washing, namely, catalysts treated by dilute sodium hydroxide and nitric acid solutions orderly, was much more effective than single washing approach in recovering the activity, and NO conversion increased from 23.6% to 89.5% at 380°C. The higher removal efficiency of contaminants, the lower dissolution of activated V, and promoting the formation of polymeric vanadate should be the main reason for recovery of the activity. PMID:26323336

  8. Decoupling HZSM-5 catalyst activity from deactivation during upgrading of pyrolysis oil vapors.

    Science.gov (United States)

    Wan, Shaolong; Waters, Christopher; Stevens, Adam; Gumidyala, Abhishek; Jentoft, Rolf; Lobban, Lance; Resasco, Daniel; Mallinson, Richard; Crossley, Steven

    2015-02-01

    The independent evaluation of catalyst activity and stability during the catalytic pyrolysis of biomass is challenging because of the nature of the reaction system and rapid catalyst deactivation that force the use of excess catalyst. In this contribution we use a modified pyroprobe system in which pulses of pyrolysis vapors are converted over a series of HZSM-5 catalysts in a separate fixed-bed reactor controlled independently. Both the reactor-bed temperature and the Si/Al ratio of the zeolite are varied to evaluate catalyst activity and deactivation rates independently both on a constant surface area and constant acid site basis. Results show that there is an optimum catalyst-bed temperature for the production of aromatics, above which the production of light gases increases and that of aromatics decrease. Zeolites with lower Si/Al ratios give comparable initial rates for aromatics production, but far more rapid catalyst deactivation rates than those with higher Si/Al ratios. PMID:25504857

  9. Probing the carboxyester side chain in controlled deactivation (-)-δ(8)-tetrahydrocannabinols.

    Science.gov (United States)

    Nikas, Spyros P; Sharma, Rishi; Paronis, Carol A; Kulkarni, Shashank; Thakur, Ganesh A; Hurst, Dow; Wood, JodiAnne T; Gifford, Roger S; Rajarshi, Girija; Liu, Yingpeng; Raghav, Jimit Girish; Guo, Jason Jianxin; Järbe, Torbjörn U C; Reggio, Patricia H; Bergman, Jack; Makriyannis, Alexandros

    2015-01-22

    We recently reported on a controlled deactivation/detoxification approach for obtaining cannabinoids with improved druggability. Our design incorporates a metabolically labile ester group at strategic positions within the THC structure. We have now synthesized a series of (-)-Δ(8)-THC analogues encompassing a carboxyester group within the 3-alkyl chain in an effort to explore this novel cannabinergic chemotype for CB receptor binding affinity, in vitro and in vivo potency and efficacy, as well as controlled deactivation by plasma esterases. We have also probed the chain's polar characteristics with regard to fast onset and short duration of action. Our lead molecule, namely 2-[(6aR,10aR)-6a,7,10,10a-tetrahydro-1-hydroxy-6,6,9-trimethyl-6H-dibenzo[b,d]pyran-3-yl]-2-methyl-propanoic acid 3-cyano-propyl ester (AM7438), showed picomolar affinity for CB receptors and is deactivated by plasma esterases while the respective acid metabolite is inactive. In further in vitro and in vivo experiments, the compound was found to be a remarkably potent and efficacious CB1 receptor agonist with relatively fast onset/offset of action. PMID:25470070

  10. Expertise-related deactivation of the right temporoparietal junction during musical improvisation.

    Science.gov (United States)

    Berkowitz, Aaron L; Ansari, Daniel

    2010-01-01

    Musical training has been associated with structural changes in the brain as well as functional differences in brain activity when musicians are compared to nonmusicians on both perceptual and motor tasks. Previous neuroimaging comparisons of musicians and nonmusicians in the motor domain have used tasks involving prelearned motor sequences or synchronization with an auditorily presented sequence during the experiment. Here we use functional magnetic resonance imaging (fMRI) to examine expertise-related differences in brain activity between musicians and nonmusicians during improvisation--the generation of novel musical-motor sequences--using a paradigm that we previously used in musicians alone. Despite behaviorally matched performance, the two groups showed significant differences in functional brain activity during improvisation. Specifically, musicians deactivated the right temporoparietal junction (rTPJ) during melodic improvisation, while nonmusicians showed no change in activity in this region. The rTPJ is thought to be part of a ventral attentional network for bottom-up stimulus-driven processing, and it has been postulated that deactivation of this region occurs in order to inhibit attentional shifts toward task-irrelevant stimuli during top-down, goal-driven behavior. We propose that the musicians' deactivation of the rTPJ during melodic improvisation may represent a training-induced shift toward inhibition of stimulus-driven attention, allowing for a more goal-directed performance state that aids in creative thought.

  11. SMFs-supported Pd nanocatalysts in selective acetylene hydrogenation:Pore structure-dependent deactivation mechanism

    Institute of Scientific and Technical Information of China (English)

    Elaheh; Esmaeili; Ali; Morad; Rashidi; Yadollah; Mortazavi; Abbas; Ali; Khodadadi; Mehdi; Rashidzadeh

    2013-01-01

    In the present study,CNFs,ZnO and Al2O3 were deposited on the SMFs panels to investigate the deactivation mechanism of Pd-based catalysts in selective acetylene hydrogenation reaction.The examined supports were characterized by SEM,NH3-TPD and N2adsorption-desorption isotherms to indicate their intrinsic characteristics.Furthermore,in order to understand the mechanism of deactivation,the resulted green oil was characterized using FTIR and SIM DIS.FTIR results confirmed the presence of more unsaturated constituents and then,more branched hydrocarbons formed upon the reaction over alumina-supported catalyst in comparison with the ones supported on CNFs and ZnO,which in turn,could block the pores mouths.Besides the limited hydrogen transfer,N2 adsorption-desorption isotherms results supported that the lowest pore diameters of Al2O3/SMFs close to the surface led to fast deactivation,compared with the other catalysts,especially at higher temperatures.

  12. Mathematics anxiety reduces default mode network deactivation in response to numerical tasks

    Directory of Open Access Journals (Sweden)

    Belinda ePletzer

    2015-04-01

    Full Text Available Mathematics anxiety is negatively related to mathematics performance, thereby threatening the professional success. Preoccupation with the emotional content of the stimuli may consume working memory resources, which may be reflected in decreased deactivation of areas associated with the default mode network (DMN activated during self-referential and emotional processing. The common problem is that math anxiety is usually associated with poor math performance, so that any group differences are difficult to interpret.Here we compared the BOLD-response of 18 participants with high (HMAs and 18 participants with low mathematics anxiety (LMAs matched for their mathematical performance to two numerical tasks (number comparison, number bisection. During both tasks, we found stronger deactivation within the DMN in LMAs compared to HMAs, while BOLD-response in task-related activation areas did not differ between HMAs and LMAs. The difference in DMN deactivation between the HMA and LMA group was more pronounced in stimuli with additional requirement on inhibitory functions, but did not differ between number magnitude processing and arithmetic fact retrieval.

  13. Mathematics anxiety reduces default mode network deactivation in response to numerical tasks.

    Science.gov (United States)

    Pletzer, Belinda; Kronbichler, Martin; Nuerk, Hans-Christoph; Kerschbaum, Hubert H

    2015-01-01

    Mathematics anxiety is negatively related to mathematics performance, thereby threatening the professional success. Preoccupation with the emotional content of the stimuli may consume working memory resources, which may be reflected in decreased deactivation of areas associated with the default mode network (DMN) activated during self-referential and emotional processing. The common problem is that math anxiety is usually associated with poor math performance, so that any group differences are difficult to interpret. Here we compared the BOLD-response of 18 participants with high (HMAs) and 18 participants with low mathematics anxiety (LMAs) matched for their mathematical performance to two numerical tasks (number comparison, number bisection). During both tasks, we found stronger deactivation within the DMN in LMAs compared to HMAs, while BOLD-response in task-related activation areas did not differ between HMAs and LMAs. The difference in DMN deactivation between the HMA and LMA group was more pronounced in stimuli with additional requirement on inhibitory functions, but did not differ between number magnitude processing and arithmetic fact retrieval.

  14. Study of the scapular muscle latency and deactivation time in people with and without shoulder impingement.

    Science.gov (United States)

    Phadke, Vandana; Ludewig, Paula M

    2013-04-01

    Changes in muscle activities are commonly associated with shoulder impingement and theoretically caused by changes in motor program strategies. The purpose of this study was to assess for differences in latencies and deactivation times of scapular muscles between subjects with and without shoulder impingement. Twenty-five healthy subjects and 24 subjects with impingement symptoms were recruited. Glenohumeral kinematic data and myoelectric activities using surface electrodes from upper trapezius (UT), lower trapezius (LT), serratus anterior (SA) and anterior fibers of deltoid were collected as subjects raised and lowered their arm in response to a visual cue. Data were collected during unloaded, loaded and after repetitive arm raising motion conditions. The variables were analyzed using 2 or 3 way mixed model ANOVAs. Subjects with impingement demonstrated significantly earlier contraction of UT while raising in the unloaded condition and an earlier deactivation of SA across all conditions during lowering of the arm. All subjects exhibited an earlier activation and delayed deactivation of LT and SA in conditions with a weight held in hand. The subjects with impingement showed some significant differences to indicate possible differences in motor control strategies. Rehabilitation measures should consider appropriate training measures to improve movement patterns and muscle control. PMID:23137918

  15. Deactivation mechanism and feasible regeneration approaches for the used commercial NH3-SCR catalysts.

    Science.gov (United States)

    Yu, Yanke; Meng, Xiaoran; Chen, Jinsheng; Yin, Liqian; Qiu, Tianxue; He, Chi

    2016-01-01

    The deactivation and regeneration of selective catalytic reduction catalysts which have been used for about 37,000 h in a coal power plant are studied. The formation of Al2(SO4)3, surface deposition of K, Mg and Ca are primary reasons for the deactivation of the studied Selective catalytic reduction catalysts. Other factors such as activated V valence alteration also contribute to the deactivation. Reactivation of used catalysts via environment-friendly and finance-feasibly approaches, that is, dilute acid or alkali solution washing, would be of great interest. Three regeneration pathways were studied in the present work, and dilute nitric acid or sodium hydroxide solution could remove most of the contaminants over the catalyst surface and partly recover the catalytic performance. Notably, the acid-alkali combination washing, namely, catalysts treated by dilute sodium hydroxide and nitric acid solutions orderly, was much more effective than single washing approach in recovering the activity, and NO conversion increased from 23.6% to 89.5% at 380°C. The higher removal efficiency of contaminants, the lower dissolution of activated V, and promoting the formation of polymeric vanadate should be the main reason for recovery of the activity.

  16. Attention-induced deactivations in very low frequency EEG oscillations: differential localisation according to ADHD symptom status.

    Directory of Open Access Journals (Sweden)

    Samantha J Broyd

    Full Text Available BACKGROUND: The default-mode network (DMN is characterised by coherent very low frequency (VLF brain oscillations. The cognitive significance of this VLF profile remains unclear, partly because of the temporally constrained nature of the blood oxygen-level dependent (BOLD signal. Previously we have identified a VLF EEG network of scalp locations that shares many features of the DMN. Here we explore the intracranial sources of VLF EEG and examine their overlap with the DMN in adults with high and low ADHD ratings. METHODOLOGY/PRINCIPAL FINDINGS: DC-EEG was recorded using an equidistant 66 channel electrode montage in 25 adult participants with high- and 25 participants with low-ratings of ADHD symptoms during a rest condition and an attention demanding Eriksen task. VLF EEG power was calculated in the VLF band (0.02 to 0.2 Hz for the rest and task condition and compared for high and low ADHD participants. sLORETA was used to identify brain sources associated with the attention-induced deactivation of VLF EEG power, and to examine these sources in relation to ADHD symptoms. There was significant deactivation of VLF EEG power between the rest and task condition for the whole sample. Using s-LORETA the sources of this deactivation were localised to medial prefrontal regions, posterior cingulate cortex/precuneus and temporal regions. However, deactivation sources were different for high and low ADHD groups: In the low ADHD group attention-induced VLF EEG deactivation was most significant in medial prefrontal regions while for the high ADHD group this deactivation was predominantly localised to the temporal lobes. CONCLUSIONS/SIGNIFICANCE: Attention-induced VLF EEG deactivations have intracranial sources that appear to overlap with those of the DMN. Furthermore, these seem to be related to ADHD symptom status, with high ADHD adults failing to significantly deactivate medial prefrontal regions while at the same time showing significant attenuation of

  17. Importance of counterion reactivity on the deactivation of Co-salen catalysts in the hydrolytic kinetic resolution of epichlorohydrin.

    Science.gov (United States)

    Jain, Surbhi; Zheng, Xiaolai; Jones, Christopher W; Weck, Marcus; Davis, Robert J

    2007-10-15

    Possible modes of deactivation of Jacobsen's Co-salen catalyst during the hydrolytic kinetic resolution (HKR) of epichlorohydrin were explored by UV-vis spectroscopy, X-ray absorption spectroscopy, and electrospray ionization mass spectrometry, combined with recycling studies. Although an active Co(III)-salen catalyst deactivated substantially after multiple cycles without regeneration, the catalyst maintained its +3 oxidation state throughout the runs. Thus, deactivation of Co-salen during HKR was not the result of Co reduction. The mass spectrum of a deactivated material showed that catalyst dimerization does not account for the loss of activity. Results from various catalyst pretreatment tests, as well as from catalysts containing various counterions (acetate, tosylate, chloride, iodide) indicated that the rate of addition of the Co-salen counterions to epoxide forming Co-OH during the reaction correlated with deactivation. The extent of counterion addition to epoxide was influenced by the exposure time and the nucleophilicity of the counterion. An oligo(cyclooctene)-supported Co-OAc salen catalyst, which was 25 times more active than the standard Co-salen catalyst, was recycled multiple times with negligible deactivation. PMID:17850142

  18. Plasma Deactivation of Oral Bacteria Seeded on Hydroxyapatite Disks as Tooth Enamel Analogue

    Science.gov (United States)

    Blumhagen, Adam; Singh, Prashant; Mustapha, Azlin; Chen, Meng; Wang, Yong; Yu, Qingsong

    2014-01-01

    Purpose To study the plasma treatment effects on deactivation of oral bacteria seeded on a tooth enamel analogue. Methods A non-thermal atmospheric pressure argon plasma brush was used to treat two different Gram-positive oral bacteria including Lactobacillus acidophilus (L. acidophilus) and Streptococcus mutans (S. mutans). The bacteria were seeded on hydroxyapatite (HA) disks used as tooth enamel analogue with three initial bacterial seeding concentrations: a low inoculum concentration between 2.1×108 and 2.4×108 cfu/mL, a medium inoculum concentration between 9.8×108 and 2.4×109 cfu/mL, and a high inoculum concentration between 1.7×1010 and 3.5×1010 cfu/mL. The bacterial survivability upon plasma exposure was examined in terms of plasma exposure time and oxygen addition into the plasmas. SEM was performed to examine bacterial morphological changes after plasma exposure. Results The experimental data indicated that 13 second plasma exposure time completely killed all the bacteria when initial bacterial seeding density on HA surfaces were less than 6.9×106 cfu/cm2 for L. acidophilus and 1.7×107 cfu/cm2 for S. mutans, which were resulted from low initial seeding inoculum concentration between 2.1×108 and 2.4×108 cfu/mL. Plasma exposure of the bacteria at higher initial bacterial seeding density obtained with high initial seeding inoculum concentration, however, only resulted in ~ 1.5 to 2 log reduction and ~ 2 to 2.5 log reduction for L. acidophilus and S. mutans, respectively. It was also noted that oxygen addition into the argon plasma brush did not affect the plasma deactivation effectiveness. SEM images showed that plasma deactivation mainly occurred with the top layer bacteria, while shadowing effects from the resulting bacterial debris reduced the plasma deactivation of the underlying bacteria. Clinical Significance The experimental results indicate that, with direct contact, nonthermal atmospheric pressure argon plasmas could rapidly and

  19. Catalytic Combustion of Gasified Waste

    Energy Technology Data Exchange (ETDEWEB)

    Kusar, Henrik

    2003-09-01

    This thesis concerns catalytic combustion for gas turbine application using a low heating-value (LHV) gas, derived from gasified waste. The main research in catalytic combustion focuses on methane as fuel, but an increasing interest is directed towards catalytic combustion of LHV fuels. This thesis shows that it is possible to catalytically combust a LHV gas and to oxidize fuel-bound nitrogen (NH{sub 3}) directly into N{sub 2} without forming NO{sub x} The first part of the thesis gives a background to the system. It defines waste, shortly describes gasification and more thoroughly catalytic combustion. The second part of the present thesis, paper I, concerns the development and testing of potential catalysts for catalytic combustion of LHV gases. The objective of this work was to investigate the possibility to use a stable metal oxide instead of noble metals as ignition catalyst and at the same time reduce the formation of NO{sub x} In paper II pilot-scale tests were carried out to prove the potential of catalytic combustion using real gasified waste and to compare with the results obtained in laboratory scale using a synthetic gas simulating gasified waste. In paper III, selective catalytic oxidation for decreasing the NO{sub x} formation from fuel-bound nitrogen was examined using two different approaches: fuel-lean and fuel-rich conditions. Finally, the last part of the thesis deals with deactivation of catalysts. The various deactivation processes which may affect high-temperature catalytic combustion are reviewed in paper IV. In paper V the poisoning effect of low amounts of sulfur was studied; various metal oxides as well as supported palladium and platinum catalysts were used as catalysts for combustion of a synthetic gas. In conclusion, with the results obtained in this thesis it would be possible to compose a working catalytic system for gas turbine application using a LHV gas.

  20. Data quality objectives summary report for the 107-N Basin Recirculation Building liquid/sediment

    International Nuclear Information System (INIS)

    The Data Quality Objectives (DQO) process used for this 107-N Basin Recirculation Building liquid/sediment DQO report followed BHI-EE-01, Environmental Investigations Procedures, EIIP 1.2, Data Quality Objectives, Revision 2. Tri-Party Agreement Milestone (M-16-OIE) states that the 100-N Area deactivation must be performed according to the work scope identified in the N Reactor Deactivation Program Plan (WHC 1993c). Consistent with the N Reactor Deactivation Program Plan, the scope of the 107-N liquid/sediment DQO process exclusively involves the determination of sampling requirements during the deactivation period. The sampling requirements are primarily directed at characterization for comparison to decontamination and decommissioning endpoint acceptance criteria in preparation for turnover of the facilities listed below to the D and D organization. The sample characterization will also be used for selection of the appropriate disposition option for liquid and sediment currently contained in the facility. The primary media within the scope of this DQO includes the following: Accumulated liquids and sediment contained in tanks, vessels, pump wells, sumps, associated piping, and valve pit floors; and Limited solid debris (anticipated to be discovered)

  1. Diagnosis of solid waste of oil and natural gas exploration and production activities in Brazil offshore sedimentary basins; Diagnostico dos residuos solidos das atividades de exploracao e producao de petroleo e gas natural em bacias sedimentares maritimas no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Koehler, Pedro Henrique Wisniewski; Mendonca; Gilberto Moraes de

    2012-07-01

    The objective of this study is to analyze the generation and disposal of solid waste from the exploration and production activities of oil and natural gas in Brazilian waters. We used data from the implementation reports of pollution control project of the activities licensed by IBAMA. During 2009 the activities related to exploration and production of offshore oil and gas produced a total of 44,437 tons of solid waste, with the main waste generated corresponding to: oily waste (16,002 t); Metal uncontaminated (11,085 t); contaminated waste (5630 t), non recycling waste (4935 t); Wood uncontaminated (1,861 t), chemicals (1,146 t). Considering the total waste generated by activities during the period analyzed, it was observed that 54.3% are made up of waste Class I (hazardous waste), 27.9% of Class II wastes (waste non-hazardous non-inert); and 17.8% of waste Class IIB (non-hazardous and inert waste). The results obtained in this work enabled the scenario of waste generation by the E and P offshore activities. As a result, the survey serves as a starting point for monitoring the progress in implementing the projects sought Pollution Control of licensed projects, as well as support the monitoring of reflexes arising from the intensification of activities in certain regions. (author)

  2. Delaware Basin Monitoring Annual Report

    International Nuclear Information System (INIS)

    The Delaware Basin Drilling Surveillance Program (DBDSP) is designed to monitor drilling activities in the vicinity of the Waste Isolation Pilot Plant (WIPP). This program is based on Environmental Protection Agency (EPA) requirements. The EPA environmental standards for the management and disposal of transuranic (TRU) radioactive waste are codified in 40 CFR Part 191 (EPA 1993). Subparts B and C of the standard address the disposal of radioactive waste. The standard requires the Department of Energy (DOE) to demonstrate the expected performance of the disposal system using a probabilistic risk assessment or performance assessment (PA). This PA must show that the expected repository performance will not release radioactive material above limits set by the EPA's standard. This assessment must include the consideration of inadvertent drilling into the repository at some future time.

  3. Deactivation of Ni{sub 2}P/SiO{sub 2} catalyst in hydrodechlorination of chlorobenzene

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jixiang, E-mail: jxchen@tju.edu.cn; Ci, Donghui; Yang, Qing; Li, Kelun

    2014-11-30

    Highlights: • Ni{sub 2}P/SiO{sub 2} has higher performance than Ni/SiO{sub 2} for hydrodechlorination. • Ni{sub 2}P has higher resistance to HCl poison and to sintering than Ni. • Ni{sub 2}P/SiO{sub 2} deactivation is mainly attributed to carbonaceous deposit. • Ni/SiO{sub 2} deactivation is mostly due to HCl poison and Ni sintering. - Abstract: The deactivation of the Ni{sub 2}P/SiO{sub 2} catalyst in the hydrodechlorination of chlorobenzene was studied. To better illuminate the reasons for the deactivation, the effect of HCl on the structure and activity of Ni{sub 2}P/SiO{sub 2} was investigated. For comparison, the deactivation of the Ni/SiO{sub 2} catalyst was also involved. It was found that the Ni{sub 2}P particles possessed good resistance to HCl poison and to sintering, which is ascribed to the electron-deficiency of Ni{sup δ+}(0 < δ < 1) site in Ni{sub 2}P. Acted as the Lewis and Brönsted acid site, the Ni{sup δ+} site and the P-OH group on Ni{sub 2}P/SiO{sub 2} catalyzed the formation of the carbonaceous deposit that was difficultly eliminated by hydrogenation. The carbonaceous deposit covered the active sites and might also induce a decrease in the Ni{sub 2}P crystallinity, subsequently leading to the Ni{sub 2}P/SiO{sub 2} deactivation. Different from Ni{sub 2}P/SiO{sub 2}, Ni/SiO{sub 2} was mainly deactivated by the chlorine poison and the sintering of nickel crystallites.

  4. Long term deactivation test of high dust SCR catalysts by straw co-firing

    Energy Technology Data Exchange (ETDEWEB)

    Weigang Lin; Degn Jensen, A.; Bjerkvig, J.

    2009-12-15

    The consequences of carbon dioxide induced global warming cause major concern worldwide. The consumption of energy produced with fossil fuels is the major factor that contributes to the global warming. Biomass is a renewable energy resource and has a nature of CO{sub 2} neutrality. Co-combustion of biomass in existing coal fired power plants can maintain high efficiency and reduce the emission of CO{sub 2} at same time. However, one of the problems faced by co-firing is deactivation of the SCR catalysts. Understanding of the mechanisms of deactivation of the catalyst elements at co-firing conditions is crucial for long term runs of the power plants. Twenty six SCR catalyst elements were exposed at two units (SSV3 and SSV4) in the Studstrup Power Plant for a long period. Both units co-fire coal and straw with a typical fraction of 8-10% straw on an energy basis during co-firing. SSV4 unit operated in co-firing mode most of the time; SSV3 unit co-fired straw half of the operating time. The main objective of this PSO-project is to gain knowledge of a long term influence on catalyst activity when co-firing straw in coal-fired power plants, thus, to improve the basis for operating the SCR-plants for NO{sub x}-reduction. The exposure time of the applied catalyst elements (HTAS and BASF) varied from approximately 5000 to 19000 hours in the power plant by exchanging the element two times. The activity of all elements was measured before and after exposure in a bench scale test rig at the Department of Chemical and Biochemical Engineering, Technical University of Denmark. The results show that the activity, estimated by exclusion of channel clogging of the elements, decreases gradually with the total exposure time. It appears that the exposure time under co-firing condition has little effect on the deactivation of the catalyst elements and no sharp decrease of the activity was observed. The average deactivation rate of the catalyst elements is 1.6 %/1000 hours. SEM

  5. Brain deactivation in the outperformance in bimodal tasks: an FMRI study.

    Directory of Open Access Journals (Sweden)

    Tzu-Ching Chiang

    Full Text Available While it is known that some individuals can effectively perform two tasks simultaneously, other individuals cannot. How the brain deals with performing simultaneous tasks remains unclear. In the present study, we aimed to assess which brain areas corresponded to various phenomena in task performance. Nineteen subjects were requested to sequentially perform three blocks of tasks, including two unimodal tasks and one bimodal task. The unimodal tasks measured either visual feature binding or auditory pitch comparison, while the bimodal task required performance of the two tasks simultaneously. The functional magnetic resonance imaging (fMRI results are compatible with previous studies showing that distinct brain areas, such as the visual cortices, frontal eye field (FEF, lateral parietal lobe (BA7, and medial and inferior frontal lobe, are involved in processing of visual unimodal tasks. In addition, the temporal lobes and Brodmann area 43 (BA43 were involved in processing of auditory unimodal tasks. These results lend support to concepts of modality-specific attention. Compared to the unimodal tasks, bimodal tasks required activation of additional brain areas. Furthermore, while deactivated brain areas were related to good performance in the bimodal task, these areas were not deactivated where the subject performed well in only one of the two simultaneous tasks. These results indicate that efficient information processing does not require some brain areas to be overly active; rather, the specific brain areas need to be relatively deactivated to remain alert and perform well on two tasks simultaneously. Meanwhile, it can also offer a neural basis for biofeedback in training courses, such as courses in how to perform multiple tasks simultaneously.

  6. Study on the thermal deactivation of motorcycle catalytic converters by laboratory aging tests.

    Science.gov (United States)

    Chen, Yi-Chi; Chen, Lu-Yen; Yu, Yi-Hsien; Jeng, Fu-Tien

    2010-03-01

    Catalytic converters are used to curb exhaust pollution from motorcycles in Taiwan. A number of factors, including the length of time the converter is used for and driving conditions, affect the catalysts' properties during periods of use. The goal of this study is to resolve the thermal deactivation mechanism of motorcycle catalytic converters. Fresh catalysts were treated under different aging conditions by laboratory-scale aging tests to simulate the operation conditions of motorcycle catalytic converters. The aged catalysts were characterized by analytical techniques in order to provide information for investigating deactivation phenomena. The time-dependent data of specific surface areas were subsequently used to construct kinetics of sintering at the specific temperature. According to the analytical results of the catalysts' properties, the increase in aging temperature causes an increase in pore size of the catalysts and a decrease in the specific surface area. The aged catalysts all exhibited lower performances than the fresh ones. The reduction in catalytic activity is consistent with the reduction in the loss of specific surface area. The finding of catalytic properties' dependence on temperature is consistent with the thermally activated theory. In contrast, the effect of the aging time on the specific surface area was only significant during the initial few hours. The high correlation between specific surface areas measured by the Brunauer-Emmett-Teller (BET) method and predicted by the constructed model verifies that the prediction models can predict the sintering rate reasonably under the aging conditions discussed in this study. As compared to automobile catalytic converters, the differences of structures and aging conditions are made less obvious by the deactivation phenomena of motorcycles.

  7. Quantitative study of catalytic activity and catalytic deactivation of Fe–Co/Al2O3 catalysts for multi-walled carbon nanotube synthesis by the CCVD process

    OpenAIRE

    Pirard, Sophie; Heyen, Georges; Pirard, Jean-Paul

    2010-01-01

    The catalytic deactivation during multi-walled carbon nanotube (MWNT) synthesis by the CCVD process and the influence of hydrogen on it were quantified. Initial specific reaction rate, relative specific productivity and catalytic deactivation were studied. Carbon source was ethylene, and a bimetallic iron–cobalt catalyst supported on alumina was used. The catalytic deactivation was modeled by a decreasing hyperbolic law, reflecting the progressive accumulation of amorphous carbon on active si...

  8. Deactivation Studies of Rh/Ce0.8Zr0.2O2 Catalysts in Low Temperature Ethanol Steam Reforming

    Energy Technology Data Exchange (ETDEWEB)

    Platon, Alex; Roh, Hyun-Seog; King, David L.; Wang, Yong

    2007-10-30

    Rapid deactivation of Rh/Ce0.8Zr0.2O2 catalysts in low temperature ethanol steam reforming was studied. A significant build-up of carbonaceous intermediate, instead of carbon deposit, was observed at a lower reaction temperature which was attributed to the rapid catalyst deactivation. Co-feed experiments indicated that acetone and ethylene caused more severe catalyst deactivation than other oxygenates such as acidic acid and acetaldehyde.

  9. Deactivation kinetics of V/Ti-oxide in toluene partial oxidation

    OpenAIRE

    Bulushev, D. A.; Reshetnikov, S. I.; Kiwi-Minsker, L; Renken, A.

    2001-01-01

    The deactivation kinetics of a V/Ti oxide catalyst were studied in partial oxidn. of toluene to PhCHO and PhCO2H at 523-573 K. The catalyst consists of a monolayer of VOx species, and after oxidative pretreatment, contains isolated monomeric and polymeric metavanadate-like vanadia species under dehydrated conditions as was shown by FT Raman spectroscopy. Under the reaction conditions via in situ DRIFTS, fast formation of adsorbed carboxylate and benzoate species was obsd. accompanied by disap...

  10. Step Changes and Deactivation Behavior in the Continuous Decarboxylation of Stearic Acid

    OpenAIRE

    Madsen, Anders Theilgaard; Rozmysłowicz, Bartosz; Simakova, Irina L.; Kilpiö, Teuvo; Leino, Anne-Riikka; Kordás, Krisztián; Eränen, Kari; Mäki-Arvela, Päivi; Murzin, Dmitry Yu.

    2011-01-01

    Deoxygenation of dilute and concentrated stearic acid over 2% Pd/C beads was performed in a continuous reactor at 300 °C and 20 bar pressure of Ar or 5% H2/Ar. Stable operation was obtained in 5% H2 atmosphere, with 95% conversion of 10 mol % dilute stearic acid in dodecane and 12% conversion of pure stearic acid. Deactivation took place in H2-deficient gas atmosphere, probably as a result of the formation of unsaturated products and coking in the pore system. Transient experiments with step ...

  11. Electron microscopy study of the deactivation of nickel based catalysts for bio oil hydrodeoxygenation

    DEFF Research Database (Denmark)

    Gardini, Diego; Mortensen, Peter Mølgaard; Carvalho, Hudson W. P.;

    2014-01-01

    Hydrodeoxygenation (HDO) is proposed as an efficient way to remove oxygen in bio-oil, improving its quality as a more sustainable alternative to conventional fuels in terms of CO2 neutrality and relative short production cycle [1]. Ni and Ni-MoS2 nanoparticles supported on ZrO2 show potential....... Deactivation by chlorine (0.3 vol% chlorooctane) co-feeding was found to be reversible, as the catalyst could regain close to its initial deoxygenation activity upon restoration of a clean feed. SEM-EDX investigations excluded the presence of chlorine species; however, XRD analysis revealed sintering of nickel...

  12. Mechanically fully variable valvetrain and cylinder deactivation; Mechanisch vollvariabler Ventiltrieb und Zylinderabschaltung

    Energy Technology Data Exchange (ETDEWEB)

    Flierl, Rudolf; Lauer, Frederic [Technische Univ. Kaiserslautern (Germany). Lehrstuhl fuer Verbrennungskraftmaschinen

    2013-04-15

    Engines with a mechanically fully variable valvetrain on inlet and exhaust side can easily be equipped with the functionality of cylinder deactivation. Hereby the fully variable valvetrain is used for valve shut-off on particular cylinders, while the full functionality of valve lift and valve duration variation on the other valves is maintained. The effectiveness of these measures is demonstrated at the University of Kaiserslautern using a four-cylinder downsizing gasoline engine with direct injection and monoscroll turbo charger. Additionally a strategy for mode transition between four- and two-cylinder mode is presented. (orig.)

  13. Step changes and deactivation behaviour in the continuous decarboxylation of stearic acid

    DEFF Research Database (Denmark)

    Madsen, Anders Theilgaard; Rozmyslowicz, B.; Simakova, I.;

    2011-01-01

    Deoxygenation of dilute and concentrated stearic acid over 2% Pd/C beads was performed in a continuous reactor at 300 degrees C and 20 bar pressure of Ar or 5% H-2/Ar. Stable operation was obtained in 5% H-2 atmosphere, with 95% conversion of 10 mol % dilute stearic acid in dodecane and 12......% conversion of pure stearic acid. Deactivation took place in H-2-deficient gas atmosphere, probably as a result of the formation of unsaturated products and coking in the pore system. Transient experiments with step changes were performed: 1 h was required for the step change to be visible in liquid sampling...

  14. Step Changes and Deactivation Behavior in the Continuous Decarboxylation of Stearic Acid

    DEFF Research Database (Denmark)

    Madsen, Anders Theilgaard; Rozmysłowicz, Bartosz; Simakova, Irina L.;

    2011-01-01

    Deoxygenation of dilute and concentrated stearic acid over 2% Pd/C beads was performed in a continuous reactor at 300 °C and 20 bar pressure of Ar or 5% H2/Ar. Stable operation was obtained in 5% H2 atmosphere, with 95% conversion of 10 mol % dilute stearic acid in dodecane and 12% conversion of...... pure stearic acid. Deactivation took place in H2-deficient gas atmosphere, probably as a result of the formation of unsaturated products and coking in the pore system. Transient experiments with step changes were performed: 1 h was required for the step change to be visible in liquid sampling, whereas...

  15. A study on the Deactivation of Usy Zeolites with Different Rare Earth Contents

    Directory of Open Access Journals (Sweden)

    Henriques C.A.

    1998-01-01

    Full Text Available The deactivation of USY zeolites with different rare earth contents due to the coke formed from n-heptane at 450oC was studied. The results show that the presence of rare earth elements decreases the cracking and coking activities, increasing catalytic stability. However, reaction selectivity was not significantly influenced. The greater the rare earth content, the lower the coking rates and the coke contents. The TPO/DSC profiles suggested that the catalytic effect of the rare earth elements promoted coke oxidation.

  16. Deactivation of medial prefrontal and posterior cingulate cortex in anxiety disorders

    International Nuclear Information System (INIS)

    Objective: We used blood oxygenation level dependent-functional MR imaging (BOLD- fMRI) to explore the characteristics of deactivation patterns in patients with anxiety disorders and the underlying neural mechanism of this disease. Methods: Ten patients and ten healthy controls participated the experiments. All subjects performed the trait portion of the State-Trait anxiety Inventory (STAI-T) prior to the fMRI scans. The subjects underwent noninvasive functional magnetic resonance imaging while listening actively to emotionally neutral words alternating with no words (experiment 1) and threat related-words alternating with emotionally neutral words (experiment2). During fMRI scanning, subjects were instructed to closely listen to each stimuli word and to silently make a judgment of the word's valence. Data were analyzed with statistical parametric mapping (SPM 99). Individual and group analysis were conducted. Results: Mean STAI-T score was significantly higher for patients group than that of controls (58 ± 8 for patients group and 33 ± 5 for controls, t=8.3, P<0.01). Our fMRI data revealed sets of deactivation brain regions in Experiment for patients and healthy controls, however, the deactivation can be found in experiment 2 only for patients. Interestingly, all the observed deactivation patterns were similar. The related areas compromise medial prefrontal cortex(BA 10, BA 24/32), posterior cingulate (BA 31/30) and Bilateral inferior parietal cortex (MPFC) (BA 39/40), which nearly overlapping with the organized default model network. Further more, the mean t values in the MPFC area (BA 24/32) was significantly higher for control group than that of patient (5.1 controls and 4.2 for patients, t=4.8, P=0.006), conversely, the mean t values in the posterior cingulate cortex(PCC) area was significantly higher for patients l than that of controls (4.9 controls and 5.8 for patients, t=2.4, P=0.026). Conclusion: Our observations suggest that the default model network

  17. The effect of nanofiber based filter morphology on bacteria deactivation during water filtration

    Science.gov (United States)

    Kimmer, Dusan; Vincent, Ivo; Lev, Jaroslav; Kalhotka, Libor; Mikula, Premysl; Korinkova, Radka; Sambaer, Wannes; Zatloukal, Martin

    2013-04-01

    Procedures permitting to prepare homogeneous functionalized nanofibre structures based on polyurethanes modified by phthalocyanines (PCs) by employing a suitable combination of variables during the electrospinning process are presented. Compared are filtration and bacteria deactivation properties of open and planar nanostructures with PCs embedded into polyurethane chain by a covalent bond protecting the release of active organic compound during the filtration process. Finding that the morphology of functionalized nanofibre structures have an effect on bacterial growth was confirmed by microbiological and physico-chemical analyses, such as the inoculation in a nutrient agar culture medium and flow cytometry.

  18. A procedure for the deactivation of radium-containing waters and solutions

    International Nuclear Information System (INIS)

    Radium-containing waters and solutions can be deactivated by mixing the stirred liquid with sludge arising during the production of barium compounds, after leaching off barium sulfit which is formed by heating the flotated baryte concentrate with coke or coal at 1100-1300 degC; water and/or HCl are used for th leaching. The amount of sludge taken per m3 of the radioactive liquid corresponds to 3-100 g of dry sludge matter. The resultin solid is separated from the purified water, e.g., by sedimentation and filtration. (P.A.)

  19. Bimetallic nickel-iron nanoparticles for groundwater decontamination: effect of groundwater constituents on surface deactivation.

    Science.gov (United States)

    Han, Yanlai; Yan, Weile

    2014-12-01

    The incorporation of catalytic metals on iron nanoparticles to form bimetallic nanoparticles (BNPs) generates a class of highly reactive materials for degrading chlorinated hydrocarbons (e.g., trichloroethylene, TCE) in groundwater. Successful implementation of BNPs to groundwater decontamination relies critically on the stability of surface reactive sites of BNPs in groundwater matrices. This study investigated the effect of common groundwater solutes on TCE reduction with Ni-Fe (with Ni at 2 wt.%) bimetallic nanoparticles (herein denoted as Ni-Fe BNPs). Batch experiments involving pre-exposing the nanoparticles to various groundwater solutions for 24 h followed by reactions with TCE solutions were conducted. The results suggest that the deactivation behavior of Ni-Fe BNPs differs significantly from that of the well-studied Pd-Fe BNPs. Specifically, Ni-Fe BNPs were chemically stable in pure water. Mild reduction in TCE reaction rates were observed for Ni-Fe BNPs pre-exposed to chloride (Cl(-)), bicarbonate (HCO3(-)), sulfite (SO3(2-)) and humic acid solutions. Nitrate (NO3(-)), sulfate (SO4(2-)) and phosphate (HPO4(2-)) may cause moderate to severe deactivation at elevated concentrations (>1 mM). Product analysis and surface chemistry investigations using high-resolution X-ray photoelectron spectroscopy (HR-XPS) reveal that NO3(-) decreased particle reactivity mainly due to progressive formation of passivating oxides, whereas SO4(2-) and phosphate elicited rapid deactivation as a result of specific poisoning of the surface nickel sites. At similar levels, phosphate is the most potent deactivation agent among the solutes examined in this study. While our findings point out the desirable quality of Ni-Fe nanoparticles, particularly their greater electrochemical stability compared to Pd-Fe BNPs, its susceptibility to chemical poisoning at high levels of complexing ligands is also noted. Groundwater chemistry is therefore an important factor to consider when

  20. TiO2 Nanotubes with Open Channels as Deactivation-Resistant Photocatalyst for the Degradation of Volatile Organic Compounds.

    Science.gov (United States)

    Weon, Seunghyun; Choi, Wonyong

    2016-03-01

    We synthesized ordered TiO2 nanotubes (TNT) and compared their photocatalytic activity with that of TiO2 nanoparticles (TNP) film during the repeated cycles of photocatalytic degradation of gaseous toluene and acetaldehyde to test the durability of TNT as an air-purifying photocatalyst. The photocatalytic activity of TNT showed only moderate reduction after the five cycles of toluene degradation, whereas TNP underwent rapid deactivation as the photocatalysis cycles were repeated. Dynamic SIMS analysis showed that carbonaceous deposits were formed on the surface of TNP during the photocatalytic degradation of toluene, which implies that the photocatalyst deactivation should be ascribed to the accumulation of recalcitrant degradation intermediates (carbonaceous residues). In more oxidizing atmosphere (100% O2 under which less carbonaceous residues should form), the photocatalytic activity of TNP still decreased with repeating cycles of toluene degradation, whereas TNT showed no sign of deactivation. Because TNT has a highly ordered open channel structure, O2 molecules can be more easily supplied to the active sites with less mass transfer limitation, which subsequently hinders the accumulation of carbonaceous residues on TNT surface. Contrary to the case of toluene degradation, both TNT and TNP did not exhibit any significant deactivation during the photocatalytic degradation of acetaldehyde, because the generation of recalcitrant intermediates from acetaldehyde degradation is insignificant. The structural characteristics of TNT is highly advantageous in preventing the catalyst deactivation during the photocatalytic degradation of aromatic compounds. PMID:26854616

  1. Deactivation of hydrophobic Pt/SDBC catalyst in the WTRF LPCE column for tritium separation

    International Nuclear Information System (INIS)

    The styrene divinylbenzene copolymer (SDBC) supported platinum catalyst and the liquid phase catalytic exchange (LPCE) column have been developed to be applicable to the Wolsong tritium removal facility (WTRF) in Korea. The catalyst deactivation subject to both reversible uniform poisoning and permanent loss by impurity poisoning was investigated using a time-on-stream theory and a simplified shell progressive poisoning scenario in special case of higher internal diffusion resistance. Experimental data from fixed bed reactors with the Pt/SDBC catalysts have been used to establish the deactivation model and to estimate key parameters to be used in the WTRF LPCE column design. It was found that an impurity control in the streams would be critical to the WTRF LPCE column operation since the impurity poisoning played a very important role in the overall catalytic exchange reaction. Except for the case of the severe impurity poisoning of the whole catalysts, the LPCE column can be in operation over 10 years without any regeneration of the catalysts. (author)

  2. Impact of Cylinder Deactivation on Active Diesel Particulate Filter Regeneration at Highway Cruise Conditions

    Directory of Open Access Journals (Sweden)

    Xueting eLu

    2015-08-01

    Full Text Available Abstract—Heavy-duty over-the-road trucks require periodic active diesel particulate filter regeneration to clean the filter of stored particulate matter. These events require sustained temperatures between 500 and 600□C to complete the regeneration process. Engine operation during typical 65 mile/hour highway cruise conditions (1200 rpm/7.6 bar results in temperatures of approximately 350□C, and can reach approximately 420□C with late fuel injection. This necessitates hydrocarbon fueling of a diesel oxidation catalyst or burner located upstream of the diesel particulate filter to reach the required regeneration temperatures. These strategies require increased fuel consumption, and the presence of a fuel-dosed oxidation catalyst (or burner between the engine and particulate filter. This paper experimentally demonstrates that, at the highway cruise condition, deactivation of valve motions and fuel injection for two or three (of six cylinders can instead be used to reach engine outlet temperatures of 520-570□C, a 170-220□C increase compared to normal operation. This is primarily a result of a reduction in the air-to-fuel ratio realized by reducing the displaced cylinder volume through cylinder deactivation.

  3. Synergistic effect of metal deactivator and antioxidant on oxidation stability of metal contaminated Jatropha biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Sarin, Amit [Department of Applied Sciences, Amritsar College of Engineering and Technology, Amritsar 143001 (India); Arora, Rajneesh; Singh, N.P. [Punjab Technical University, Jalandhar (India); Sarin, Rakesh; Malhotra, R.K. [Indian Oil Corporation Ltd., R and D Centre, Sector-13, Faridabad 121007 (India); Sharma, Meeta [Indian Oil Corporation Ltd., R and D Centre, Sector-13, Faridabad 121007 (India); University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, Kashmere Gate, Delhi 110403 (India); Khan, Arif Ali [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, Kashmere Gate, Delhi 110403 (India)

    2010-05-15

    Biodiesel is relatively unstable on storage and European biodiesel standard EN-14214 calls for determining oxidation stability at 110 C with a minimum induction time of 6 h by the Rancimat method (EN-14112). According to proposed National Mission on biodiesel in India, we have undertaken studies on stability of biodiesel from tree borne non-edible oil seeds Jatropha. Neat Jatropha biodiesel exhibited oxidation stability of 3.95 h. It is found possible to meet the desired EN specification for neat Jatropha biodiesel and metal contaminated Jatropha biodiesel by using antioxidants; it will have a cost implication, as antioxidants are costly chemicals. Research was conducted to increase the oxidation stability of metal contaminated Jatropha biodiesel by doping metal deactivator with antioxidant, with varying concentrations in order to meet the aforementioned standard required for oxidation stability. It was found that usage of antioxidant can be reduced by 30-50%, therefore the cost, even if very small amount of metal deactivator is doped in Jatropha biodiesel to meet EN-14112 specification. (author)

  4. Berberine inhibits inflammatory mediators and attenuates acute pancreatitis through deactivation of JNK signaling pathways.

    Science.gov (United States)

    Choi, Sun-Bok; Bae, Gi-Sang; Jo, Il-Joo; Wang, Shaofan; Song, Ho-Joon; Park, Sung-Joo

    2016-06-01

    Acute pancreatitis (AP) is a life-threatening disease. Berberine (BBR), a well-known plant alkaloid, is reported to have anti-inflammatory activity in many diseases. However, the effects of BBR on AP have not been clearly elucidated. Therefore, the present study aimed to investigate the effects of BBR on cerulein-induced AP in mice. AP was induced by either cerulein or l-arginine. In the BBR treated group, BBR was administered intraperitoneally 1h before the first cerulein or l-arginine injection. Blood samples were obtained to determine serum amylase and lipase activities and nitric oxide production. The pancreas and lung were rapidly removed for examination of histologic changes, myeloperoxidase (MPO) activity, and real-time reverse transcription-polymerase chain reaction. Furthermore, the regulating mechanisms of BBR were evaluated. Treatment of mice with BBR reduced pancreatic injury and activities of amylase, lipase, and pancreatitis-associated lung injury, as well as inhibited several inflammatory parameters such as the expression of pro-inflammatory cytokines and inducible nitric oxide synthesis (iNOS). Furthermore, BBR administration significantly inhibited c-Jun N-terminal kinase (JNK) activation in the cerulein-induced AP. Deactivation of JNK resulted in amelioration of pancreatitis and the inhibition of inflammatory mediators. These results suggest that BBR exerts anti-inflammatory effects on AP via JNK deactivation on mild and severe acute pancreatitis model, and could be a beneficial target in the management of AP. PMID:27148818

  5. H{sub 2} production from methane pyrolysis over commercial carbon catalysts: Kinetic and deactivation study

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, D.P.; Botas, J.A. [Chemical and Environmental Technology Department, ESCET, Rey Juan Carlos University, C/Tulipan s/n, 28933 Mostoles (Spain); IMDEA Energia, C/Tulipan s/n, 28933 Mostoles (Spain); Guil-Lopez, R. [Chemical and Environmental Technology Department, ESCET, Rey Juan Carlos University, C/Tulipan s/n, 28933 Mostoles (Spain)

    2009-05-15

    Hydrogen production from catalytic methane decomposition (DeCH{sub 4}) is a simple process to produce high purity hydrogen with no formation of carbon oxides (CO or CO{sub 2}). However, to completely avoid those emissions, the catalyst must not be regenerated. Therefore, it is necessary to use inexpensive catalysts, which show low deactivation during the process. Use of carbon materials as catalysts fulfils these requirements. Methane decomposition catalysed by a number of commercial carbons has been studied in this work using both constant and variable temperature experiments. The results obtained showed that the most active catalyst at short reaction times was activated carbon, but it underwent a fast deactivation due to the deposition of the carbon formed from methane cracking. On the contrary, carbon blacks, and especially the CB-bp sample, present high reaction rates for methane decomposition at both short and long reaction times. Carbon nanotubes exhibit a relatively low activity in spite of containing significant amounts of metals. The initial loss of activity observed with the different catalysts is attributed mainly to the blockage of their micropores due to the deposition of the carbon formed during the reaction. (author)

  6. Elementary reaction steps of NOx trapping and SOx deactivation of NOx storage reduction catalysts

    International Nuclear Information System (INIS)

    The NOx storage reduction concept offers a promising strategy for exhaust aftertreatment of lean-bum and diesel engines. However, to meet further more stringent emission regulations, the sulfur resistance of these catalysts has to be improved. Therefore, a detailed knowledge of the NOx storage reduction mechanism and the SOx deactivation mechanism is important to achieve suitable catalysts. The aim of this thesis is, therefore, to obtain a fundamental insight in the NOx adsorption/reduction mechanism and the SOx deactivation mechanism occurring on NSR (non-selective reduction) catalysts to be able to structure the complex reaction sequences into specific key elementary steps. In chapter 2 the experimental details employed in this thesis are given. The adsorption and reduction mechanisms of NOx on sodium and barium metal exchanged zeolite Y used as model storage components are elucidated in chapter 3. With this knowledge, a detailed investigation of the mechanism of NOx storage on a commercial NSR catalyst was carried out and discussed in chapter 4. The influence of SO2 on the catalytic performance of the catalyst is explored in chapter 5. The information obtained in Chapter 5 was used for a detailed investigation of the interaction of SOx with the storage and the oxidation/reduction component (Chapter 6). Finally, in Chapter 7 the results of these study are summarized and general conclusions are given

  7. The role of arsine in the deactivation of methanol synthesis catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, R.; Mebrahtu, T.; Dahl, T.A.; Lucrezi, F.A.; Toseland, B.A. [Air Products and Chemicals Inc., Adsorption Technology Center, 7201 Hamilton Boulevard, Allentown, PA 18195-1501 (United States)

    2004-06-18

    The liquid phase methanol (LPMEOH) process is successfully producing methanol from coal-derived synthesis gas on an industrial scale. This process uses a standard copper, zinc oxide, and alumina catalyst suspended in an inert mineral oil in a slurry bubble column reactor. An arsenic-containing species, most reasonably arsine, was found in the feed to the LPMEOH commercial demonstration facility located at Eastman Chemical Company's chemicals-from-coal complex in Kingsport, TN. Laboratory testing showed that arsine is, in fact, a powerful methanol synthesis catalyst poison. At levels as low as 150ppbv, arsine results in a rapid deactivation of the catalyst. Removal of arsine results in a deactivation rate consistent with a clean synthesis gas feed; that is, arsine poisoning stops when it is removed from the feed. We infer that arsine reacts irreversibly with the catalyst under the methanol synthesis conditions. X-ray absorption spectroscopy (XAS) of arsenic-containing used catalyst indicated the presence of zero-valent arsenic in an intermetallic surface phase that is structurally related to Domeykite (Cu{sub 3}As). Experimental evidence, thermodynamics, and literature relating to other metal-arsine chemistry were consistent with dissociative adsorption of arsine on the copper surface to form gaseous H{sub 2} and Cu{sub 3}As. To deal with arsine poisoning, we have developed adsorption technology that can remove arsine to levels low enough that catalyst performance is unaffected.

  8. Paths of deactivation of excitation of chlorophyll a in various model systems

    Science.gov (United States)

    Frackowiak, Danuta; Zelent, Bogumil; Malak, Henryk M.; Cegielski, Roman; Planner, Alfons; Goc, Jacek; Niedbalska, Malgorzata

    1994-08-01

    Chlorophyll a (Chl) in most model systems (monolayers, fluid solvents, adsorbed layers, and polymer films) occurs in three forms: `dry monomers' (isolated from interaction with water), hydrated dimers and oligomers built from such dimers; but in nematic liquid crystal (LC) cell `dry monomers' are predominant. It is a competition between the various paths of deactivation of excited Chl. Excitation energy can be emitted as fluorescence, or delayed luminescence, transferred to other forms of Chl (ET), thermally deactivated or used for photochemical reactions. In order to compare the efficiency of these various paths the following measurements were done and analyzed: absorption, fluorescence, fluorescence excitation, photoacoustic spectra, and lifetime of fluorescence in ps range. There are some important differences between Chl in LC cell and polymer films: Chl in LC cell has a much lower concentration of aggregated forms and the pigment molecules are more uniformly distributed as compared to the Chl in polymer samples. To explain ET in polymer films the fractals model has to be used, whereas mean distances between solvated Chl molecules in LC can be obtained from dye concentration. In order to establish the interaction between Chl a and (beta) -carotene the LC cell with both pigments were also investigated.

  9. Task-related deactivation and functional connectivity of the subgenual cingulate cortex in major depressive disorder

    Directory of Open Access Journals (Sweden)

    Christopher G Davey

    2012-02-01

    Full Text Available Background: Major depressive disorder is associated with functional alterations in activity and resting-state connectivity of the extended medial frontal network. In this study we aimed to examine how task-related medial network activity and connectivity were affected by depression.Methods: Eighteen patients with major depressive disorder, aged 15- to 24-years-old, were matched with 19 healthy control participants. We characterised task-related activations and deactivations while participants engaged with an executive-control task (the multi-source interference task; MSIT. We used a psycho-physiological interactions (PPI approach to examine functional connectivity changes with subgenual ACC. Voxelwise statistical maps for each analysis were compared between the patient and control groups.Results: There were no differences between groups in their behavioral performances on the MSIT task, and nor in patterns of activation and deactivation. Assessment of functional connectivity with the subgenual cingulate showed that depressed patients did not demonstrate the same reduction in functional connectivity with the ventral striatum during task performance, but that they showed greater reduction in functional connectivity with adjacent ventromedial frontal cortex. The magnitude of this latter connectivity change predicted the relative activation of task-relevant executive control regions in depressed patients.Conclusions: The study reinforces the importance of the subgenual cingulate cortex for depression, and demonstrates how dysfunctional connectivity with ventral brain regions might influence executive–attentional processes.

  10. Insight into deactivation of commercial SCR catalyst by arsenic: an experiment and DFT study.

    Science.gov (United States)

    Peng, Yue; Li, Junhua; Si, Wenzhe; Luo, Jinming; Dai, Qizhou; Luo, Xubiao; Liu, Xin; Hao, Jiming

    2014-12-01

    Fresh and arsenic-poisoned V2O5–WO3/TiO2 catalysts are investigated by experiments and DFT calculations for SCR activity and the deactivation mechanism. Poisoned catalyst (1.40% of arsenic) presents lower NO conversion and more N2O formation than fresh. Stream (5%) could further decrease the activity of poisoned catalyst above 350 °C. The deactivation is not attributed to the loss of surface area or phase transformation of TiO2 at a certain arsenic content, but due to the coverage of the V2O5 cluster and the decrease in the surface acidity: the number of Lewis acid sites and the stability of Brønsted acid sites. Large amounts of surface hydroxyl induced by H2O molecules provide more unreactive As–OH groups and give rise to a further decrease in the SCR activity. N2O is mainly from NH3 unselective oxidation at high temperatures since the reducibility of catalysts and the number of surface-active oxygens are improved by As2O5. Finally, the reaction pathway seems unchanged after poisoning: NH3 adsorbed on both Lewis and Brønsted acid sites is reactive.

  11. HEU Measurements of Holdup and Recovered Residue in the Deactivation and Decommissioning Activities of the 321-M Reactor Fuel Fabrication Facility at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    DEWBERRY, RAYMOND; SALAYMEH, SALEEM R.; CASELLA, VITO R.; MOORE, FRANK S.

    2005-03-11

    This paper contains a summary of the holdup and material control and accountability (MC&A) assays conducted for the determination of highly enriched uranium (HEU) in the deactivation and decommissioning (D&D) of Building 321-M at the Savannah River Site (SRS). The 321-M facility was the Reactor Fuel Fabrication Facility at SRS and was used to fabricate HEU fuel assemblies, lithium-aluminum target tubes, neptunium assemblies, and miscellaneous components for the SRS production reactors. The facility operated for more than 35 years. During this time thousands of uranium-aluminum-alloy (U-Al) production reactor fuel tubes were produced. After the facility ceased operations in 1995, all of the easily accessible U-Al was removed from the building, and only residual amounts remained. The bulk of this residue was located in the equipment that generated and handled small U-Al particles and in the exhaust systems for this equipment (e.g., Chip compactor, casting furnaces, log saw, lathes A & B, cyclone separator, Freon{trademark} cart, riser crusher, ...etc). The D&D project is likely to represent an important example for D&D activities across SRS and across the Department of Energy weapons complex. The Savannah River National Laboratory was tasked to conduct holdup assays to quantify the amount of HEU on all components removed from the facility prior to placing in solid waste containers. The U-235 holdup in any single component of process equipment must not exceed 50 g in order to meet the container limit. This limit was imposed to meet criticality requirements of the low level solid waste storage vaults. Thus the holdup measurements were used as guidance to determine if further decontamination of equipment was needed to ensure that the quantity of U-235 did not exceed the 50 g limit and to ensure that the waste met the Waste Acceptance Criteria (WAC) of the solid waste storage vaults. Since HEU is an accountable nuclear material, the holdup assays and assays of recovered

  12. Deactivation of hydrophobic catalysts for a hydrogen isotope exchange: Application of the time-on-stream theory

    International Nuclear Information System (INIS)

    A recycle reactor was built for the purpose of characterizing newly developed hydrophobic catalysts for a hydrogen isotope exchange. The catalytic rate constants of two types of hydrophobic catalysts were measured at a 100% relative humidity. The catalytic rate constants were measured at 60 deg C for 28 days and both the catalysts showed very high initial catalytic rate constants. The measured deactivation profile showed that the catalytic rate constants of both the catalysts were almost identical for 28 days. The deactivation of the catalysts was modelled based upon the time-on-stream theory. The deactivation profiles of the catalysts were estimated by using the model for a period of three years. The results showed that both the catalysts had a good exchange capacity for hydrogen isotopes and they could be applicable to a tritium removal facility that will be built at the Wolsong nuclear power plants in the near future

  13. Gas phase polymerization of ethylene with a silica-supported metallocene catalyst: influence of temperature on deactivation

    OpenAIRE

    Roos, Peter; Meier, Gerben B.; Samson, Job Jan C.; Weickert, Günter; Westerterp, K. Roel

    1997-01-01

    Ethylene was polymerized at 5 bar in a stirred powder bed reactor with silica supported rac-Me2Si[Ind]2ZrCl2/methylaluminoxane (MAO) at temperatures between 40°C and 80°C using NaCl as support bed and triethylaluminium (TEA) as a scavenger for impurities. For this fixed recipe and a given charge of catalyst. the average catalyst activity is reproducible within 10% for low temperatures. The polymerization rate and the rate of deactivation increase with increasing temperature. The deactivation ...

  14. Falls related to accidental deactivation of deep brain stimulators in patients with Parkinson's disease living in long term care facilities.

    Science.gov (United States)

    Tousi, Babak; Wilson, Kathy

    2013-01-01

    This case series highlights three patients with Parkinson's disease residing at nursing home facilities whose deep brain stimulators were accidentally deactivated for varying lengths of time, which was associated with an increase in falls. In all three cases, neither the patients nor the caregivers were aware of the random deactivations/reactivations. We propose a specific care plan for these patients that includes further education of caregivers regarding deep brain stimulators and regular checks of the review device, especially when there is concern about a patient's mobility or balance that is out of character.

  15. Does self-ligating brackets type influence the hysteresis, activation and deactivation forces of superelastic NiTi archwires?

    OpenAIRE

    José Rino Neto; Gilberto Vilanova Queiroz; João Batista Paiva; Rafael Yagüe Ballester

    2013-01-01

    OBJECTIVE: To compare hysteresis, activation and deactivation forces produced by first-order deformation of Contour 0.014-in NiTi wire (Aditek, Brazil) in four brands of self-ligating brackets: Damon MX, Easy Clip, Smart Clip and In-Ovation. METHODS: Activation and deactivation forces were measured in an Instron universal tensile machine at 3 mm/minute speed to a total displacement of 4 mm. Tests were repeated eight times for each bracket/wire combination. Statistical analysis comprised ANOVA...

  16. Tank waste remediation system dangerous waste training plan

    International Nuclear Information System (INIS)

    This document outlines the dangerous waste training program developed and implemented for all Treatment, Storage, and Disposal (TSD) Units operated by Lockheed Martin Hanford Corporation (LMHC) Tank Waste Remediation System (TWRS) in the Hanford 200 East, 200 West and 600 Areas and the <90 Day Accumulation Area at 209E. Operating TSD Units operated by TWRS are: the Double-Shell Tank (DST) System (including 204-AR Waste Transfer Building), the 600 Area Purgewater Storage and the Effluent Treatment Facility. TSD Units undergoing closure are: the Single-Shell Tank (SST) System, 207-A South Retention Basin, and the 216-B-63 Trench

  17. Tank waste remediation system dangerous waste training plan; TOPICAL

    International Nuclear Information System (INIS)

    This document outlines the dangerous waste training program developed and implemented for all Treatment, Storage, and Disposal (TSD) Units operated by Lockheed Martin Hanford Corporation (LMHC) Tank Waste Remediation System (TWRS) in the Hanford 200 East, 200 West and 600 Areas and the and lt;90 Day Accumulation Area at 209E. Operating TSD Units operated by TWRS are: the Double-Shell Tank (DST) System (including 204-AR Waste Transfer Building), the 600 Area Purgewater Storage and the Effluent Treatment Facility. TSD Units undergoing closure are: the Single-Shell Tank (SST) System, 207-A South Retention Basin, and the 216-B-63 Trench

  18. 济南市邢家渡灌区废弃沉沙池生态风险等级评价研究%STUDY ON THE GRADE EVALUATION OF ECOLOGICAL RISK IN WASTE SAND BASIN OF XING JIADU YELLOW RIVER IRRIGATION AREA IN JINAN

    Institute of Scientific and Technical Information of China (English)

    石礼文; 苏红鲁; 张扩成; 张厚芹

    2016-01-01

    The waste sand basin of Xing Jiadu in Jinan was a major desilting basin in downstream of the Xing Jiadu Yellow River irrigation area,before and after operation for nearly 30 years,it had stopped using in 2002,and there are about 204 hm2 land was abandoned,which had become sandstorm source of Jinan. Study on waste sand basin ecological risk level,has important significance to the regional development,environmental governance. Using ArcGIS software,three evaluation index of the wind,erosion modulus,vegetation coverage and soil sand content was selected to evaluate the ecological risk level by using conditional filtering method. The results showed that the area of moderate risk,heavy risk and severe risk are accounting for 92. 92% of the total area of the waste sand basin. Ecological risk is relatively high,and the regional ecological security status of the overall assessment is not safe.%济南市邢家渡沉沙池曾是黄河下游邢家渡引黄灌区上的一个主干沉沙池,运行近30年,于2002年停止使用,沉沙池约204 hm2的土地彻底废弃,已成为济南市区风沙的源头之一.研究废弃沉沙池生态风险等级,对区域开发、环境治理有重要的意义.利用ARCGIS软件,选取风蚀模数,植被覆盖度,土壤含沙量三个评价指标,利用条件过滤法,进行生态风险等级评价研究.结果表明,中度风险、较重风险、重度风险的面积,占废弃沉沙池总面积的92.92%,生态风险较高,该区域生态安全状态总体评价为不安全.

  19. Waste management

    OpenAIRE

    Knopová Policarová, Táňa

    2014-01-01

    Diploma thesis deals with waste disposal in the Czech Republic, including waste production and waste recovery. The aim of this work is to characterize and evaluate the waste production, sorting a disposal in the Czech Republic. Theoretical basis of diploma thesis are focused on basic concepts of waste management legislation, the generation of waste and how to prevent the formation or at least reduce it. The greatest attention is paid to waste disposal, in which there are presented and analyze...

  20. Deactivation of lipopolysaccharide by Ar and H2 inductively coupled low-pressure plasma

    Science.gov (United States)

    Bartis, E. A. J.; Barrett, C.; Chung, T.-Y.; Ning, N.; Chu, J.-W.; Graves, D. B.; Seog, J.; Oehrlein, G. S.

    2014-01-01

    Using an inductively coupled plasma system, we study the effects of direct plasma, plasma-generated high-energy photons in the ultraviolet and vacuum ultraviolet (UV/VUV), and radical treatments on lipopolysaccharide (LPS). LPS is a biomolecule found in the outer membrane of Gram-negative bacteria and a potent stimulator of the immune system composed of polysaccharide and lipid A, which contains six aliphatic chains. LPS film thickness spun on silicon was monitored by ellipsometry while the surface chemistry was characterized before and after treatments by x-ray photoelectron spectroscopy (XPS). Additionally, biological activity was measured using an enzyme-linked immunosorbent assay under (a) a sensitive regime (sub-µM concentrations of LPS) and (b) a bulk regime (above µM concentrations of LPS) after plasma treatments. Direct plasma treatment causes rapid etching and deactivation of LPS in both Ar and H2 feed gases. To examine the effect of UV/VUV photons, a long-pass filter with a cut-off wavelength of 112 nm was placed over the sample. H2 UV/VUV treatment causes material removal and deactivation due to atomic and molecular UV/VUV emission while Ar UV/VUV treatment shows minimal effects as Ar plasma does not emit UV/VUV photons in the transmitted wavelength range explored. Interestingly, radical treatments remove negligible material but cause deactivation. Based on the amphiphilic structure of LPS, we expect a lipid A rich surface layer to form at the air-water interface during sample preparation with polysaccharide layers underneath. XPS shows that H2 plasma treatment under direct and UV/VUV conditions causes oxygen depletion through removal of C-O and O-C = O bonds in the films, which does not occur in Ar treatments. Damage to these groups can remove aliphatic chains that contribute to the pyrogenicity of LPS. Radical treatments from both Ar and H2 plasmas remove aliphatic carbon from the near-surface, demonstrating the important role of neutral species.

  1. Residential Waste

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Fruergaard, Thilde; Matsufuji, Y.

    2011-01-01

    are discussed in this chapter. Characterizing residential waste is faced with the problem that many residences already divert some waste away from the official collection systems, for example performing home composting of vegetable waste and garden waste, having their bundled newspaper picked up by......Residential waste comes from residential areas with multi-family and single-family housing and includes four types of waste: household waste, garden waste, bulky waste and household hazardous waste. Typical unit generation rates, material composition, chemical composition and determining factors...... the scouts twice a year or bringing their used furniture to the flea markets organized by charity clubs. Thus, much of the data available on residential waste represents collected waste and not necessarily all generated waste. The latter can only be characterized by careful studies directly at the...

  2. Residential Waste

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Fruergaard, Thilde; Matsufuji, Y.

    2011-01-01

    Residential waste comes from residential areas with multi-family and single-family housing and includes four types of waste: household waste, garden waste, bulky waste and household hazardous waste. Typical unit generation rates, material composition, chemical composition and determining factors...... are discussed in this chapter. Characterizing residential waste is faced with the problem that many residences already divert some waste away from the official collection systems, for example performing home composting of vegetable waste and garden waste, having their bundled newspaper picked up by...... the scouts twice a year or bringing their used furniture to the flea markets organized by charity clubs. Thus, much of the data available on residential waste represents collected waste and not necessarily all generated waste. The latter can only be characterized by careful studies directly at the...

  3. Dopant deactivation and annealing characteristics of metal-oxide-semiconductor structures on germanium/boron-doped silicon after gamma irradiation or Fowler--Nordheim charge injection

    Energy Technology Data Exchange (ETDEWEB)

    Hashemipour, O.; Ang, S.S.; Brown, W.D.; Yeargan, J.R. (Department of Electrical Engineering, 3217 Bell Engineering Center, University of Arkansas, Fayetteville, Arkansas 72701 (USA)); West, L. (Department of Mechanical Engineering, University of Arkansas, Fayetteville, Arkansas 72701 (USA))

    1991-08-01

    Dopant deactivation and thermal annealing characteristics of metal-oxide-semiconductor capacitors fabricated on Ge/B-doped silicon after gamma irradiation or Fowler--Nordheim injection were investigated for the first time. A decrease of about 30% in active acceptor concentration was observed immediately after gamma irradiation or Fowler--Nordheim injection. Further deactivation of boron ({similar to}20%) occurred with annealing for temperatures of 80 {degree}C and higher. Hydrogen for the deactivation, which occurred during annealing, is thought to come from dissociation of weakly bonded Ge---H formed during the gamma irradiation or Fowler--Nordheim injection. Capacitors fabricated on conventional boron-doped substrates do not exhibit acceptor deactivation as a result of annealing following irradiation or injection. For annealing temperatures of 110 {degree}C and higher, the boron is first deactivated by the process noted above, and then is apparently reactivated by the dissociation of B---H bonds with hydrogen evolution from the structure.

  4. Reversible-Deactivation Radical Polymerization of Methyl Methacrylate Induced by Photochemical Reduction of Various Copper Catalysts

    Directory of Open Access Journals (Sweden)

    Jaroslav Mosnáček

    2014-11-01

    Full Text Available Photochemically mediated reversible-deactivation radical polymerization of methyl methacrylate was successfully performed using 50–400 ppm of various copper compounds such as CuSO4·5H2O, copper acetate, copper triflate and copper acetylacetonate as catalysts. The copper catalysts were reduced in situ by irradiation at wavelengths of 366–546 nm, without using any additional reducing agent. Bromopropionitrile was used as an initiator. The effects of various solvents and the concentration and structure of ligands were investigated. Well-defined polymers were obtained when at least 100 or 200 ppm of any catalyst complexed with excess tris(2-pyridylmethylamine as a ligand was used in dimethyl sulfoxide as a solvent.

  5. On the effect of atomic structure on the deactivation of catalytic gold nanoparticles

    International Nuclear Information System (INIS)

    Here we present atomic scale studies into the nature of both the internal structure and external surfaces of catalytic Au nanoparticles using aberration corrected in-situ electron microscopy. The activity of catalytic nanoparticles is thought to be highly sensitive to the particles' structure, meaning typical local atomic rearrangements are likely to significantly affect the overall performance of the catalyst. As-deposited Au nanoparticles are found to exhibit a variety of morphologies, with many being internally strained or highly stepped at the surface. Upon heating, surface atoms are observed to minimise the particles' surface energy by restructuring towards planar (111) facets, resulting in the removal of low co-ordinated sites thought to be crucial in catalysis by Au nanoparticles. These results suggest the process of surface energy minimisation made possible by heating may lead to a loss of active sites and consequently contribute to the deactivation of the catalyst.

  6. Purification of deactivated hydrodesulfurization catalysts by radiation thermal treatment and the extraction of molybdenum from them

    International Nuclear Information System (INIS)

    Methods of fluorescent X-ray radiometric element determination, electron spectroscopy of diffusion reflection and X-ray diffraction analysis were used to study transformations in 670-1370 K range in deactivated Ni(Co)Mo/Al2O3 catalysts, initiated by the effect of high-power accelerated 2.0 MeV electron beam irradiation leads to crystallization of a series of Mo-containing phases, easily destroyed in result of high-temperature radiolysis. Sublimation of Mo6+ oxide with low temperature threshold (∼ 770 K), proceeding in result of radiation-thermal treatment, is described. Decrease of temperatrure threshold is explained by reactions of radiolysis of Mo-containing compounds. 19 refs., 4 figs

  7. Extraction and purification of molybdenum from deactivated hydrodesulfurization catalysts by radiation-thermal treatment

    International Nuclear Information System (INIS)

    The radiation-thermal processes induced by intense fast electron beams of up to 2.0 MeV energy in deactivated Ni(Co)-Mo/Al2O3 catalysts in the 670 - 1370 K temperature interval are studied by fluorescence X-ray radiometric element analysis, UV-Vis diffuse reflectance spectroscopy, and X-ray diffraction analysis. It is shown that electron-beam irradiation results in crystallization of a number of Mo-containing phases, which are readily destroyed during high-temperature radiolysis. In addition to the production of aluminonickel spinel and corundum phases free of C and S, Mo(VI) oxide sublimation characterized by the low-temperature threshold (∼770 K) is found to occur during radiation-thermal treatment. The lowering of the temperature threshold is explained by radiolysis of Mo-containing compounds. 19 refs., 4 figs

  8. A competitive and reversible deactivation approach to catalysis-based quantitative assays.

    Science.gov (United States)

    Koide, Kazunori; Tracey, Matthew P; Bu, Xiaodong; Jo, Junyong; Williams, Michael J; Welch, Christopher J

    2016-01-01

    Catalysis-based signal amplification makes optical assays highly sensitive and widely useful in chemical and biochemical research. However, assays must be fine-tuned to avoid signal saturation, substrate depletion and nonlinear performance. Furthermore, once stopped, such assays cannot be restarted, limiting the dynamic range to two orders of magnitude with respect to analyte concentrations. In addition, abundant analytes are difficult to quantify under catalytic conditions due to rapid signal saturation. Herein, we report an approach in which a catalytic reaction competes with a concomitant inactivation of the catalyst or consumption of a reagent required for signal generation. As such, signal generation proceeds for a limited time, then autonomously and reversibly stalls. In two catalysis-based assays, we demonstrate restarting autonomously stalled reactions, enabling accurate measurement over five orders of magnitude, including analyte levels above substrate concentration. This indicates that the dynamic range of catalysis-based assays can be significantly broadened through competitive and reversible deactivation. PMID:26891765

  9. TiO2 on and around a deactivated hydrodesulphurization catalyst

    Science.gov (United States)

    Makovsky, L. E.; Pollack, S. S.; Brown, F. R.

    1980-11-01

    The nature of the titanium found to accumulate around a deactivated catalyst used for the promotion of the liquefaction and desulphurization of coal is investigated. Examination of the titanium deposits found on and around spent Co-Mo on alumina catalysts used in a fixed-bed reactor reveals most of the deposit to be composed of the anatase form of TiO2, with smaller amounts of calcite, gypsum and quartz. X-ray diffraction linewidth measurements indicate a crystallite size for the anatase material in the deposit in the range 190-260 A, with a c axis of 9.460 A, which is slightly less than that measured for pure anatase. Possible origins of the anatase material by the oxidation of organically bound coal titanium during liquefaction or the presence of 200-A anatase crystallites in the original coal are discussed.

  10. ALARA Review for the Decontamination, Deactivation and Housekeeping of the 233-S Viewing Room

    International Nuclear Information System (INIS)

    A formal as low as reasonably achievable (ALARA) review is required by BHI-SH-02, Vol. 1, Safety and Health Procedures, Procedure 1.22, 'Planning Radiological Work', when radiological conditions exceed trigger level. The level of contamination inside the viewing room of the 233-S Facility meets this criterion. This ALARA review is for task instructions 1997-03-18-005-8.3.1, 'Instructions for Routine Entries and Minor Maintenance Work at 233-S,' and 8.3.2, 'Instructions for Deactivation, Decon, and Housekeeping in Viewing Room.' The radiological work permit (RWP) request broke the two task instructions into nine separate tasks. The nine tasks identified in the RWP request were used to estimate airborne concentrations and the total exposure

  11. Study on Deactivation and Cracking Performance of Catalysts Containing Y and MFI Zeolites

    Institute of Scientific and Technical Information of China (English)

    Chen Zhenyu; Li Caiying; Tian Huiping; Huang Zhiqing

    2004-01-01

    This article investigated the deactivation caused by hydrothermal treatment and metal contamination of two cracking catalysts containing the Y and ZRP- 1 zeolites aimed at maximization of light olefin yield.Test results had shown that the hydrothermal stability and resistance to metal contamination of the ZRP-1zeolite were apparently better than those of the Y zeolite. Hydrothermal treatment and metal contamination had not only changed the catalytic cracking performance of respective zeolites, but at the same time had also modified to a definite degree of the relative proportions of effective components in these two zeolites and affected the synergistic effects between them, resulting in a relative enhancement of secondary cracking ability of the catalyst and increased olefin selectivity in the FCC products. In the course of application of catalyst for maximization of light olefins yield appropriate adjustment of the relative proportion of two active components can help to alleviate the products distribution and selectivity changes caused by deactivationof FCC catalysts.

  12. Radiationless deactivation of 6-aminocoumarin from the S1-ICT state in nonspecifically interacting solvents.

    Science.gov (United States)

    Krystkowiak, Ewa; Dobek, Krzysztof; Burdziński, Gotard; Maciejewski, Andrzej

    2012-08-01

    This paper presents the results of a spectral (absorption and emission) and photophysical study of 6-aminocoumarin (6AC) in the solvents with which this molecule interacts only nonspecifically (n-alkanes, tetrachloromethane and 1-chloro-n-alkanes) and in nitriles. The strong effects of the solvents on the emission spectra, fluorescence quantum yield and lifetime of 6AC were observed. The results of the steady-state and time-resolved photophysical study suggest the presence of very fast nonradiative deactivation processes. It is concluded that besides fluorescence, the efficient S(1)-ICT → S(0) internal conversion in nonpolar aprotic solvents arises from vibronic interactions between close-lying S(1)-ICT(π,π*) and S(2)(n,π*) states. Moreover, unexpectedly efficient triplet state formation occurs. In nitriles the intermolecular hydrogen-bonding interactions with solvent molecules also facilitate the nonradiative decay process involving the S(1)-exciplex. PMID:22622372

  13. A new integrative model of cerebral activation, deactivation and default mode function in Alzheimer's disease

    International Nuclear Information System (INIS)

    Functional imaging methods such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) allow in vivo assessment of cerebral metabolism at rest and cerebral responses to cognitive stimuli. Activation studies with different cognitive tasks have deepened the understanding of underlying pathology leading to Alzheimer disease (AD) and how the brain reacts to and potentially compensates the imposed damage inflicted by this disease. The aim of this manuscript study was to summarize current findings of activation studies in healthy people at risk for AD, in people with mild cognitive impairment (MCI) as a possible progenitor of AD and finally in patients with manifest AD, adding recent results about impaired deactivation abilities and default mode function in AD. A new comprehensive model will be introduced integrating these heterogeneous findings and explaining their impact on cognitive performance. (orig.)

  14. Catalytic ramifications of steam deactivation of Y zeolites: An analysis using 2-methylhexane cracking

    Energy Technology Data Exchange (ETDEWEB)

    Yaluris, G.; Dumesic, J.A. [Univ. of Wisconsin, Madison, WI (United States); Madon, R.J. [Engelhard Corp., Iselin, NJ (United States)

    1999-08-15

    Kinetic analysis of experimental data for 2-methylhexane cracking demonstrates that trends in activity and selectivity are well simulated by adjusting a single parameter that represents the acid strength of a Y-based FCC catalyst. This acid strength may be modified via steam deactivation, and the authors have experimentally corroborated acidity changes using ammonia microcalorimetry and infrared spectroscopy. Increased severity of steam treatment reduces the number and strength of catalyst acid sites, and it leads to a reduction in the turnover frequency of all surface processes and a decrease in overall site time yield. Streaming of the catalyst does not change the fundamental chemistry involved in catalytic cracking. However, change in acidity caused by steaming alters product selectivity by changing relative rates of various catalytic cycles in the cracking process. For example, steam treatment increases olefin selectivity by favoring catalytic cycles that produce olefins.

  15. Hot-plug Based Activation and Deactivation of ATCA FRU Devices

    CERN Document Server

    Predki, P

    2009-01-01

    Abstract: One of the most important features of the Advanced Telecommunications Computing Architecture (ATCA) contributing to its exceptional reliability and availability is its hot-swap functionality. In order for the user to be able to add and remove the components of an ATCA shelf without the necessity of switching the power on and off the PCI Industrial Computer Manufacturers Group (PICMG) specification clearly enumerates the stages a Field Replaceable Unit (FRU) has to go through upon insertion into and extraction from the shelf. These stages form the activation and deactivation processes that occur every time an element is changed in the ATCA system. This paper focuses on these processes placing the emphasis on the Electronic Keying (EK) implementation in the Intelligent Platform Management Controller (IPMC) software developed for the self-designed ATCA Carrier Board for FLASH. This Carrier Board utilizes the standard-defined PCI Express (PCIe) interface as well as introduces proprietary protocols in fo...

  16. Activated and deactivated functional brain areas in the Deqi state A functional MRI study

    Institute of Scientific and Technical Information of China (English)

    Yong Huang; Tongjun Zeng; Guifeng Zhang; Ganlong Li; Na Lu; Xinsheng Lai; Yangjia Lu; Jiarong Chen

    2012-01-01

    We compared the activities of functional regions of the brain in the Deqi versus non-Deqi state,as reported by physicians and subjects during acupuncture.Twelve healthy volunteers received sham and true needling at the Waiguan (TE5) acupoint.Real-time cerebral functional MRI showed that compared with non-sensation after sham needling,true needling activated Brodmann areas 3,6,8,9,10,11,13,20,21,37,39,40,43,and 47,the head of the caudate nucleus,the parahippocampal gyrus,thalamus and red nucleus.True needling also deactivated Brodmann areas 1,2,3,4,5,6,7,9,10,18,24,31,40 and 46.

  17. HE Machining Complex and Support Buildings Deactivation and Decommissioning Project at the Pantex Plant

    International Nuclear Information System (INIS)

    This paper describes the issues related to the deactivation and decommissioning of a very unique building at the Department of Energy's Pantex Plant located in Amarillo, TX. Building 12-24 was unique in the fact that it had a number of obstacles that have not been previously addressed in the deactivation and decommissioning of a single structure such as asbestos, beryllium, possible radionuclide contamination, lead paint, heavily reinforced concrete walls, and high explosive (HE) contamination inside and out. To date, the building has been razed and the majority of all equipment has been disposed of. Remaining work includes concrete and soil debris removal, earthen barricade removal, and site leveling. Pantex Site Summary: Pantex Plant is America's only nuclear weapons assembly and disassembly facility. Located on the High Plains of the Texas Panhandle, 17 miles northeast of Amarillo, Pantex is centered on a 16,000-acre site just north of U. S. Highway 60 in Carson County. The Pantex Plant industrial operations are conducted for the DOE by a management and operating contractor (BWXT Pantex), and Sandia National Laboratory. DOE owns approximately 9,100 acres at the Pantex Plant. Just over 2,000 acres of the DOE-owned property are used for industrial operations at Pantex Plant excluding the burning ground, firing sites and other outlying areas. The burning ground and firing sites occupy approximately 489 acres. Remaining DOE-owned land serves DOE safety and security purposes. DOE also owns Pantex Lake, a detached piece of property approximately 4 km (2.5 mi) northeast of the main Plant site that comprises 1,077 acres; the playa lake-bed itself occupying approximately 800 acres. Currently no government industrial operations are conducted at the Pantex Lake property. Seventy-six kilometers (47 mi) of roads exist within the Pantex Plant boundaries. Project Summary: Facilities are deactivated and decommissioned (D and D) when there is no longer a mission for them or they

  18. Activity and deactivation behavior of Au/LaMnO3 catalysts for CO oxidation

    Institute of Scientific and Technical Information of China (English)

    JIA Meilin; LI Xu; Zhaorigetu; SHEN Yuenian; LI Yunxia

    2011-01-01

    Perovskite oxide LaMnO3 was prepared by sol-gel method and the nanosize Au/LaMnO3 catalyst was prepared by deposition- precipitation (DP) method in the paper. Characterization of the catalyst sample was made by X-ray diffractometer (XRD), atom absorption spectra (AAS) and X-ray photoelectron spectroscopy (XPS) instrumental methods. The activity, long-term stability and the reasons for deactivation of the gold catalyst in CO oxidation were investigated. The experiment results demonstrated that the Au/LaMnO3 catalyst exhibited high stability in the ambient storage process. However, the gradual decrease in initial activity during 100 h reaction was still observed, which could be ascribed to the aggregation of gold particles and the transfer from gold ion to the metal gold.

  19. Standard Guide for Post-Deactivation Surveillance and Maintenance of Radiologically Contaminated Facilities

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This guide outlines a method for developing a Surveillance and Maintenance (S&M) plan for inactive nuclear facilities. It describes the steps and activities necessary to prevent loss or release of radioactive or hazardous materials, and to minimize physical risks between the deactivation phase and the start of facility decontamination and decommissioning (D&D). 1.2 The primary concerns for S&M are related to (1) animal intrusion, (2) structural integrity degradation, (3) water in-leakage, (4) contamination migration, (5) unauthorized personnel entry, and (6) theft/intrusion. This document is intended to serve as a guide only, and is not intended to modify existing regulations.

  20. O2(1△g) Deactivation on O2-adsorbed Metal Surfaces

    Institute of Scientific and Technical Information of China (English)

    Shu-yan Du; Jing Leng; He-ping Yang; Guo-he Sha; Cun-hao Zhang

    2011-01-01

    A flow system was set up to measure the quenching probability γ of O2(1△g) on various O2-adsorbed metal surfaces including Cu, Cr, Ni, and Ag. γ increased with both the duration of the experiment and the O2(1△g) concentration. After several hours evacuation to a few Pa, γ can return to its original value. A deactivation mechanism of O2(1△g) is suggested by considering first the weak chemisorption of O2 (1 △g) on the surface adsorption sites, followed by the near resonant energy transfer between the gas phase O2(1△g) and surface O2(3∑g-).A phenomenological model in accord with the experimental fact has been proposed together with relevant kinetic equations.

  1. Deactivation of carotid body chemoreceptors by hyperoxia decreases blood pressure in hypertensive patients.

    Science.gov (United States)

    Sinski, Maciej; Lewandowski, Jacek; Przybylski, Jacek; Zalewski, Paweł; Symonides, Bartosz; Abramczyk, Piotr; Gaciong, Zbigniew

    2014-09-01

    Previous studies have shown that hyperoxia-induced deactivation of carotid body chemoreceptors reduces sympathetic activity in hypertensive patients but it does not affect blood pressure. The maintenance of blood pressure can be explained by the direct, vasoconstrictive effect of hyperoxia, which offsets diminished sympathetic activity. This study compares the effect of acute hyperoxia on hemodynamic parameters between hypertensive and normotensive subjects. Twelve males with hypertension (age 39.4±2.4 years; body mass index 27.4±1.1 kg m(-2)) and 11 normotensive males (age 39.9±2.7 years; body mass index 25.4±0.7 kg m(-2)) received, via non-rebreathing mask ventilation, ambient air, followed by 100% oxygen for 20 min. The stroke volume, heart rate, cardiac output, blood pressure, total peripheral resistance, respiratory rate, baroreceptor control of heart rate and oxygen saturation were recorded continuously. Several 30 s periods were analyzed before, during and after inducing hyperoxia. At baseline, the hypertensive subject's blood pressure was higher and their baroreflex control of heart rate was lower when compared with the normotensive control group. After the first 30 s of hyperoxia, systolic, diastolic and mean blood pressures, as well as the total peripheral resistance, decreased significantly in hypertensives but not in normotensives. After 20 min of 100% oxygen ventilation, systolic and mean blood pressures and total peripheral resistance was increased in hypertensive patients, and the cardiac output and stroke volume had decreased in both groups. The results of this study confirm that deactivation of carotid body chemoreceptors can acutely decrease blood pressure in humans.

  2. Kinetics of rhodopsin deactivation and its role in regulating recovery and reproducibility of rod photoresponse.

    Directory of Open Access Journals (Sweden)

    Giovanni Caruso

    Full Text Available The single photon response (SPR in vertebrate phototransduction is regulated by the dynamics of R* during its lifetime, including the random number of phosphorylations, the catalytic activity and the random sojourn time at each phosphorylation level. Because of this randomness the electrical responses are expected to be inherently variable. However the SPR is highly reproducible. The mechanisms that confer to the SPR such a low variability are not completely understood. The kinetics of rhodopsin deactivation is investigated by a Continuous Time Markov Chain (CTMC based on the biochemistry of rhodopsin activation and deactivation, interfaced with a spatio-temporal model of phototransduction. The model parameters are extracted from the photoresponse data of both wild type and mutant mice, having variable numbers of phosphorylation sites and, with the same set of parameters, the model reproduces both WT and mutant responses. The sources of variability are dissected into its components, by asking whether a random number of turnoff steps, a random sojourn time between steps, or both, give rise to the known variability. The model shows that only the randomness of the sojourn times in each of the phosphorylated states contributes to the Coefficient of Variation (CV of the response, whereas the randomness of the number of R* turnoff steps has a negligible effect. These results counter the view that the larger the number of decay steps of R*, the more stable the photoresponse is. Our results indicate that R* shutoff is responsible for the variability of the photoresponse, while the diffusion of the second messengers acts as a variability suppressor.

  3. Facet-selective charge carrier transport, deactivation mechanism and stabilization of a Cu2O photo-electro-catalyst.

    Science.gov (United States)

    Li, Yang; Yun, Xiaogang; Chen, Hong; Zhang, Wenqin; Li, Yongdan

    2016-03-14

    A facet-dependent photo-deactivation mechanism of Cu2O was verified and reported, which is caused by the facet-dependent charge carrier transport. During irradiation, the {100} and {110} crystal facets are selectively corroded by the photo-generated holes, while the {111} facets are comparatively stable. PMID:26898270

  4. Correlating metal poisoning with zeolite deactivation in an individual catalyst particle by chemical and phase sensitive X-ray microscopy

    NARCIS (Netherlands)

    Ruiz-Martinez, J.; Beale, A.M.; Deka, U.; O'Brien, M.G.; Quinn, P.D.; Mosselmans, J.F.W.; Weckhuysen, B.M.

    2013-01-01

    Fluid catalytic cracking (FCC) is the main conversion process used in oil refineries. An X-ray microscopy method is used to show that metal poisoning and related structural changes in the zeolite active material lead to a non-uniform core–shell deactivation of FCC catalyst particles. The study links

  5. Health and safety plan for the Isotopes Facilities Deactivation Project at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    This HASP describes the process for identifying the requirements, written safety documentation, and procedures for protecting personnel involved in the Isotopes Facilities Deactivation Project. Objective of this project is to place 19 former isotope production facilities at ORNL in a safe condition in anticipation of an extended period of minimum surveillance and maintenance

  6. Deactivation of solid catalysts in liquid media: the case of leaching of active sites in biomass conversion reactions

    DEFF Research Database (Denmark)

    Sádaba, Irantzu; Lopez Granados, Manuel; Riisager, Anders;

    2015-01-01

    This review is aimed to be a brief tutorial covering the deactivation of solid catalysts in the liquid phase, with specific focus on leaching, which can be especially helpful to researchers not familiarized with catalytic processes in the liquid phase. Leaching refers to the loss of active specie...

  7. Deactivation of the Arabidopsis BRI1 receptor kinase by autophosphorylation within the glycine-rich loop involved in ATP binding

    Science.gov (United States)

    The activity of the dual-specificity brassinosteroid receptor kinase, BRI1, reflects the balance between phosphorylation-dependent activation and several potential mechanisms for deactivation of the receptor. In the present report, we identify regions of the juxtamembrane domain that are essential f...

  8. Impaired temporoparietal deactivation with working memory load in antipsychotic-naïve patients with first-episode schizophrenia

    DEFF Research Database (Denmark)

    Nejad, Ayna B; Ebdrup, Bjørn H; Siebner, Hartwig R;

    2011-01-01

    Abstract Objectives. Neuroimaging studies have shown abnormal task-related deactivations during working memory (WM) in schizophrenia patients with recent emphasis on brain regions within the default mode network. Using fMRI, we tested whether antipsychotic-naïve schizophrenia patients were impaired...

  9. K Basin sludge treatment process description

    Energy Technology Data Exchange (ETDEWEB)

    Westra, A.G.

    1998-08-28

    The K East (KE) and K West (KW) fuel storage basins at the 100 K Area of the Hanford Site contain sludge on the floor, in pits, and inside fuel storage canisters. The major sources of the sludge are corrosion of the fuel elements and steel structures in the basin, sand intrusion from outside the buildings, and degradation of the structural concrete that forms the basins. The decision has been made to dispose of this sludge separate from the fuel elements stored in the basins. The sludge will be treated so that it meets Tank Waste Remediation System (TWRS) acceptance criteria and can be sent to one of the double-shell waste tanks. The US Department of Energy, Richland Operations Office accepted a recommendation by Fluor Daniel Hanford, Inc., to chemically treat the sludge. Sludge treatment will be done by dissolving the fuel constituents in nitric acid, separating the insoluble material, adding neutron absorbers for criticality safety, and reacting the solution with caustic to co-precipitate the uranium and plutonium. A truck will transport the resulting slurry to an underground storage tank (most likely tank 241-AW-105). The undissolved solids will be treated to reduce the transuranic (TRU) and content, stabilized in grout, and transferred to the Environmental Restoration Disposal Facility (ERDF) for disposal. This document describes a process for dissolving the sludge to produce waste streams that meet the TWRS acceptance criteria for disposal to an underground waste tank and the ERDF acceptance criteria for disposal of solid waste. The process described is based on a series of engineering studies and laboratory tests outlined in the testing strategy document (Flament 1998).

  10. White matter microstructure contributes to age-related declines in task-induced deactivation of the default mode network.

    Science.gov (United States)

    Brown, Christopher A; Hakun, Jonathan G; Zhu, Zude; Johnson, Nathan F; Gold, Brian T

    2015-01-01

    Task-induced deactivations within the brain's default mode network (DMN) are thought to reflect suppression of endogenous thought processes to support exogenous goal-directed task processes. Older adults are known to show reductions in deactivation of the DMN compared to younger adults. However, little is understood about the mechanisms contributing to functional dysregulation of the DMN in aging. Here, we explored the relationships between functional modulation of the DMN and age, task performance and white matter (WM) microstructure. Participants were 117 adults ranging from 25 to 83 years old who completed an fMRI task switching paradigm, including easy (single) and difficult (mixed) conditions, and underwent diffusion tensor imaging (DTI). The fMRI results revealed an age by condition interaction (β = -0.13, t = -3.16, p = 0.002) such that increasing age affected deactivation magnitude during the mixed condition (β = -0.29, t = -3.24 p = 0.002) but not the single condition (p = 0.58). Additionally, there was a WM by condition interaction (β = 0.10, t = 2.33, p = 0.02) such that decreasing WM microstructure affected deactivation magnitude during the mixed condition (β = 0.30, t = 3.42 p = 0.001) but not the single condition (p = 0.17). Critically, mediation analyses indicated that age-related reductions in WM microstructure accounted for the relationship between age and DMN deactivation in the more difficult mixed condition. These findings suggest that age-related declines in anatomical connectivity between DMN regions contribute to functional dysregulation within the DMN in older adults. PMID:26500549

  11. White matter microstructure contributes to age-related declines in task-induced deactivation of the default mode network

    Directory of Open Access Journals (Sweden)

    Christopher A Brown

    2015-10-01

    Full Text Available Task-induced deactivations within the brain’s default mode network (DMN are thought to reflect suppression of endogenous thought processes to support exogenous goal-directed task processes. Older adults are known to show reductions in deactivation of the DMN compared to younger adults. However, little is understood about the mechanisms contributing to functional dysregulation of the DMN in aging. Here, we explored the relationships between functional modulation of the DMN and age, task performance and white matter (WM microstructure. Participants were 117 adults ranging from 25 to 83 years old who completed an fMRI task switching paradigm, including easy (single and difficult (mixed conditions, and underwent diffusion tensor imaging (DTI. The fMRI results revealed an age by condition interaction (β = -.13, t = 3.16, p = .002 such that increasing age affected deactivation magnitude during the mixed condition (β = -.29, t = -3.24 p = .002 but not the single condition (p = .58. Additionally, there was a white matter by condition interaction (β = .10, t = 2.33, p = .02 such that decreasing white matter microstructure affected deactivation magnitude during the mixed condition (β = .30, t = 3.42 p = .001 but not the single condition (p = .17. Critically, mediation analyses indicated that age-related reductions in WM microstructure accounted for the relationship between age and DMN deactivation in the more difficult mixed condition. These findings suggest that age-related declines in anatomical connectivity between DMN regions contribute to functional dysregulation within the DMN in older adults.

  12. K basins sludge removal sludge pretreatment system

    International Nuclear Information System (INIS)

    The Spent Nuclear Fuels Program is in the process of planning activities to remove spent nuclear fuel and other materials from the 100-K Basins as a remediation effort for clean closure. The 105 K- East and K-West Basins store spent fuel, sludge, and debris. Sludge has accumulated in the 1 00 K Basins as a result of fuel oxidation and a slight amount of general debris being deposited, by settling, in the basin water. The ultimate intent in removing the sludge and fuel is to eliminate the environmental risk posed by storing fuel at the K Basins. The task for this project is to disposition specific constituents of sludge (metallic fuel) to produce a product stream through a pretreatment process that will meet the requirements, including a final particle size acceptable to the Tank Waste Remediation System (TWRS). The purpose of this task is to develop a preconceptual design package for the K Basin sludge pretreatment system. The process equipment/system is at a preconceptual stage, as shown in sketch ES-SNF-01 , while a more refined process system and material/energy balances are ongoing (all sketches are shown in Appendix C). Thus, the overall process and 0535 associated equipment have been conservatively selected and sized, respectively, to establish the cost basis and equipment layout as shown in sketches ES- SNF-02 through 08

  13. Ground-water hydraulics of the deep-basin brine aquifer, Palo Duro Basin, Texas panhandle

    International Nuclear Information System (INIS)

    The Deep-Basin Brine aquifer of the Palo Duro Basin (Texas Panhandle) underlies thick Permian bedded evaporites that are being evaluated as a potential high-level nuclear waste isolation repository. Potentiometric surface maps of 5 units of the Deep-Basin Brine aquifer were drawn using drill-stem test (DST) pressure data, which were analyzed by a geostatistical technique (kriging) to smooth the large variation in the data. The potentiometric surface maps indicate that the Deep-Basin Brine aquifer could be conceptually modeled as 5 aquifer units; a Lower Permian (Wolfcamp) aquifer, upper and lower Pennsylvanian aquifers, a pre-Pennsylvanian aquifer, and a Pennsylvanian to Wolfcampian granite-wash aquifer. The hydraulic head maps indicate that ground-water flow in each of the units is west to east with a minor northerly component near the Amarillo Uplift, the northern structural boundary of the basin. The Wolfcamp potentiometric surface indicates the strongest component of northerly flow. Inferred flow direction in Pennsylvanian aquifers is easterly, and in the pre-Pennsylvanian aquifer near its pinch-out in the basin center, flow is inferred to be to the north. In the granite-wash aquifer the inferred flow direction is east across the northern edge of the basin and southeast along the Amarillo Uplift

  14. Savannah River Laboratory seepage basins: Environmental information document

    International Nuclear Information System (INIS)

    The basins are located in the northwestern section of the Savannah River Plant in the 700 Area. The four basins are out of service and are awaiting closure. When in operation, the basins received a total of 128,820 m3 of low-level radioactive wastewater from laboratories located in Buildings 735-A and 773-A. Wastewater with radioactivity less than 100 d/m/mL alpha and/or 50 d/m/mL beta-gamma was discharged to the basins. Low concentrations of radioactive and nonradioactive constituents were found in the sediments beneath the seepage basins and a statistical analysis of monitoring data from the six water-table wells indicates elevated levels of chloride, manganese, and sodium in the groundwater. The closure options considered for the basins are waste removal and closure, no waste removal and closure, and no action. The environmental impact evaluation indicates that the human health risks for all closure options are low. Radioactive risk is dominated by tritium, but there is no significant difference between the closure options because the tritium has leached from the site prior to the closure action. The most significant noncarcinogenic risk results from arsenic. All atmospheric and occupational risks are low. The primary calculated ecological effect is due to direct contact with the basin sediments in the no action option. The relative costs for the various options are $9 million for waste removal and closure, $2.9 million for no waste removal and closure with cap, $2.4 million for no waste removal and closure without cap, and $0.26 million for no action. 36 refs., 27 figs., 98 tabs

  15. A study on the deactivation and stability of hydrophobic catalyst for hydrogen isotope exchange

    International Nuclear Information System (INIS)

    The hydrophobic catalyst has been prepared by deposition of platinum on porous styrene divinylbenzene copolymers(Pt/SDBC) and at the same time a separated type catalytic reactor has been developed for the Wolsong tritium removal facility(WTRF). Several tests carried out to obtain the experimental performance data of the Pt/SDBC with a recycle reactor system. The long-term stability was also measured with the Pt/SDBC catalyst immersed in water for a long time. The long-term deactivations of the Pt/SDBC catalyst were evaluated quantitatively by mathematical models. The simple mathematical models were presented to evaluate the uniform poisoning and shell progressive poisoning to be occurred simultaneously during the hydrogen isotope exchange between hydrogen gas and liquid water in the Liquid Phase Catalytic Exchange(LPCE) column. The uniform poisoning was well characterized by a time on stream theory and then the deactivation parameters were determined from the experimental performance data. The impurity poisoning was derived by a shell progressive model with two-layer mass transfer. The water vapor condensation was a main cause of the reversible uniform poisoning for the Pt/SDBC catalyst. The values of the decay rate constant (Kd) and order of the decay reaction(m) were of 2 and 4, respectively, based on the experimental data. It indicated that the decay might be attributable to pore mouth poisoning. From the long-term stability of the catalyst immersed in water, there was no intrinsic decay of catalyst activity due to water logging to the catalyst. The activity decreased by only 7% over 18 months, which was equivalent to a catalyst half-life longer than 15 years. On the basis of the above deactivation parameters, the values for kc/kco with Thiele modulus=20 after 3 years and 10 years of operation were expected about 19% and 15% of the initial activity, respectively, while the values for kc/kco with Thiele modulus=100 were of about 22% and 18%, respectively. However

  16. Silica supported palladium nanoparticles for the decarboxylation of high-acid feedstocks: Design, deactivation and regeneration

    Science.gov (United States)

    Ping, Eric Wayne

    2011-12-01

    The major goals of this thesis were to (1) design and synthesize a supported catalyst with well-defined monodisperse palladium nanoparticles evenly distributed throughout an inorganic oxide substrate with tunable porosity characteristics, (2) demonstrate the catalytic activity of this material in the decarboxylation of long chain fatty acids and their derivatives to make diesel-length hydrocarbons, (3) elucidate the deactivation mechanism of supported palladium catalysts under decarboxylation conditions via post mortem catalyst characterization and develop a regeneration methodology thereupon, and (4) apply this catalytic system to a real low-value biofeedstock. Initial catalyst designs were based on the SBA-15 silica support, but in an effort to maximize loading and minimize mass transfer limitations, silica MCF was synthesized as catalyst support. Functionalization with various silane ligands yielded a surface that facilitated even distribution of palladium precursor salts throughout the catalyst particle, and, after reduction, monodisperse palladium nanoparticles approximately 2 nm in diameter. Complete characterization was performed on this Pd-MCF catalyst. The Pd-MCF catalyst showed high one-time activity in the decarboxylation of fatty acids to hydrocarbons in dodecane at 300°C. Hydrogen was found to be an unnecessary reactant in the absence of unsaturations, but was required in their presence---full hydrogenation of the double bonds occurs before any decarboxylation can take place. The Pd-MCF also exhibited good activity for alkyl esters and glycerol, providing a nice hypothetical description of a stepwise reaction pathway for catalytic decarboxylation of acids and their derivatives. As expected, the Pd-MCF catalyst experienced severe deactivation after only one use. Substantial effort was put into elucidating the nature of this deactivation via post mortem catalyst characterization. H2 chemisorption confirmed a loss of active surface area, but TEM and

  17. Deactivation of ferrylmyoglobin by vanillin as affected by vanillin binding to β-lactoglobulin.

    Science.gov (United States)

    Libardi, Silvia Helena; Borges, Júlio C; Skibsted, Leif H; Cardoso, Daniel R

    2011-06-01

    Vanillin was found to be efficient as a deactivator of ferrylmyoglobin with a second-order rate constant of k(2) = 57 ± 1 L mol(-1) s(-1) for reduction to metmyoglobin with ΔH(‡) = 58.3 ± 0.3 kJ mol(-1) and ΔS(‡) = -14 ± 1 J mol(-1) K(-1) in aqueous pH 7.4 solution at 25 °C. Binding to β-lactoglobulin (βLG) was found to affect the reactivity of vanillin at 25 °C only slightly to k(2) = 48 ± 2 L mol(-1) s(-1) (ΔH(‡) = 68.4 ± 0.4 kJ mol(-1) and ΔS(‡) = 17 ± 1 J mol(-1) K(-1)) for deactivation of ferrylmyoglobin. Binding of vanillin to βLG was found to have a binding stoichiometry vanillin/βLG > 10 with K(A) = 6 × 10(2) L mol(-1) and an apparent total ΔH° of approximately -38 kJ mol(-1) and ΔS° = -55.4 ± 4 J mol(-1) K(-1) at 25 °C and ΔC(p, obs) = -1.02 kJ mol(-1) K(-1) indicative of increasing ordering in the complex, as determined by isothermal titration microcalorimetry. From tryptophan fluorescence quenching for βLG by vanillin, approximately one vanillin was found to bind to each βLG far stronger with K(A) = 5 × 10(4) L mol(-1) and a ΔH° = -10.2 kJ mol(-1) and ΔS° = 55 J mol(-1) K(-1) at 25 °C. The kinetic entropy/enthalpy compensation effect seen for vanillin reactivity by binding to βLG is concluded to relate to the weakly bound vanillin oriented through hydrogen bonds on the βLG surface with the phenolic group pointing toward the solvent, in effect making both ΔH(‡) and ΔS(‡) more positive. The more strongly bound vanillin capable of tryptophan quenching in the βLG calyx seems less or nonreactive.

  18. M-Area Hazardous Waste Management Facility. Fourth Quarter 1994, Groundwater Monitoring Report

    Energy Technology Data Exchange (ETDEWEB)

    Chase, J.A.

    1995-04-20

    The unlined settling basin operated from 1958 until 1985, receiving waste water that contained volatile organic solvents used for metal degreasing and chemical constituents and depleted uranium from fuel fabrication process in M Area. The underground process sewer line transported M-Area process waste waters to the basin. Water periodically overflowed from the basin through the ditch to the seepage area adjacent to the ditch and to Lost Lake.

  19. ACIDIC REMOVAL OF METALS FROM FLUIDIZED CATALYTIC CRACKING CATALYST WASTE ASSISTED BY ELECTROKINETIC TREATMENT

    OpenAIRE

    R. B. G. Valt; A. N. Diógenes; L. S. Sanches; N. M. S. Kaminari; M. J. J. S. Ponte; H. A. Ponte

    2015-01-01

    AbstractOne of the main uses of catalysts in the oil industry is in the fluidized catalytic cracking process, which generates large quantities of waste material after use and regeneration cycles and that can be treated by the electrokinetic remediation technique, in which the contaminant metals are transported by migration. In this study, deactivated FCC catalyst was characterized before and after the electrokinetic remediation process to evaluate the amount of metal removed, and assess struc...

  20. Deactivation in Continuous Deoxygenation of C18-Fatty Feedstock over Pd/Sibunit

    DEFF Research Database (Denmark)

    Madsen, Anders Theilgaard; Rozmysłowicz, Bartosz; Mäki-Arvela, Päivi;

    2013-01-01

    Catalytic continuous deoxygenation of stearic acid, ethyl stearate and tristearin without any solvents was investigated using Pd/Sibunit as a catalyst in a trickle bed reactor at 300 °C. The main emphasis was to investigate the effect of gas atmosphere and catalyst deactivation. In addition to...... relative ratios between stearic acid, ethyl stearate and tristearin conversions to alkanes after 3 days time-on-stream were 2.8/2.3/1.0, respectively using 5 % H2/Ar as a gas atmosphere, whereas rapid catalyst deactivation occurred with all substrates under H2-lacking atmosphere. The spent catalyst......’s specific surface area profile along the downward reactor was maximum in the middle of the catalyst beds with the highest pore shrinking in the beginning and at the end of the reactor catalyst segments in the case of stearic acid and tristearin deoxygenation whereas that decreased consecutively as ethyl...

  1. Real-time piscicide tracking using Rhodamine WT dye for support of application, transport, and deactivation strategies in riverine environments

    Science.gov (United States)

    Jackson, Patrick Ryan; Lageman, Jonathan D.

    2013-01-01

    Piscicide applications in riverine environments are complicated by the advection and dispersion of the piscicide by the flowing water. Proper deactivation of the fish toxin is required outside of the treatment reach to ensure that there is minimal collateral damage to fisheries downstream or in connecting and adjacent water bodies. In urban settings and highly managed waterways, further complications arise from the influence of industrial intakes and outfalls, stormwater outfalls, lock and dam operations, and general unsteady flow conditions. These complications affect the local hydrodynamics and ultimately the transport and fate of the piscicide. This report presents two techniques using Rhodamine WT dye for real-time tracking of a piscicide plume—or any passive contaminant—in rivers and waterways in natural and urban settings. Passive contaminants are those that are present in such low concentration that there is no effect (such as buoyancy) on the fluid dynamics of the receiving water body. These methods, when combined with data logging and archiving, allow for visualization and documentation of the application and deactivation process. Real-time tracking and documentation of rotenone applications in rivers and urban waterways was accomplished by encasing the rotenone plume in a plume of Rhodamine WT dye and using vessel-mounted submersible fluorometers together with acoustic Doppler current profilers (ADCP) and global positioning system (GPS) receivers to track the dye and map the water currents responsible for advection and dispersion. In this study, two methods were used to track rotenone plumes: (1) simultaneous injection of dye with rotenone and (2) delineation of the upstream and downstream boundaries of the treatment zone with dye. All data were logged and displayed on a shipboard laptop computer, so that survey personnel provided real-time feedback about the extent of the rotenone plume to rotenone application and deactivation personnel. Further

  2. Investigation on the deactivation cause of lead-zinc double oxide for the synthesis of diphenyl carbonate by transesterification

    Institute of Scientific and Technical Information of China (English)

    Zhihui Li; Yanji Wang; Xiaoshu Ding; Xinqiang Zhao

    2009-01-01

    The deactivation cause of lead-zinc double oxide for synthesis of diphenyl carbonate (DPC) by transesterification of dimethyl carbonate (DMC) with phenol has been investigated.X-ray diffraction (XRD),X-ray photoelectron spectroscopy (XPS),infrared spectroscopy (IR),thermogravimetry analysis (TG),atomic absorption spectroscopy and elementary analysis are employed for the catalyst characterizaton.The results show that,the formation of Pb40(OC6H5)6 through the reaction of phenol and lead species in the catalyst leads to the crystal phase change of active component and serious leaching of lead,which is the cause of the catalyst deactivation.In addition,the composition of the leached lead is ascertained to be a mixture of Pb40(OC6H5)6 and PbO with the weight percentage of 62.7% and 37.3%,respectively.

  3. Deactivation of Streptococcus mutans Biofilms on a Tooth Surface Using He Dielectric Barrier Discharge at Atmospheric Pressure

    Science.gov (United States)

    Imola, Molnar; Judit, Papp; Alpar, Simon; Sorin, Dan Anghel

    2013-06-01

    This paper presents a study of the effect of the low temperature atmospheric helium dielectric barrier discharge (DBD) on the Streptococcus mutans biofilms formed on tooth surface. Pig jaws were also treated by plasma to detect if there is any harmful effect on the gingiva. The plasma was characterized by using optical emission spectroscopy. Experimental data indicated that the discharge is very effective in deactivating Streptococcus mutans biofilms. It can destroy them with an average decimal reduction time (D-time) of 19 s and about 98% of them were killed after a treatment time of 30 s. According to the survival curve kinetic an overall 32 s treatment time would be necessary to perform a complete sterilization. The experimental results presented in this study indicated that the helium dielectric barrier discharge, in plan-parallel electrode configuration, could be a very effective tool for deactivation of oral bacteria and might be a promising technique in various dental clinical applications.

  4. REVIEW OF INDUSTRIES AND GOVERNMENT AGENCIES FOR TECHNOLOGIES APPLICABLE TO DEACTIVATION AND DECOMMISSIONING OF NUCLEAR WEAPONS FACILITIES

    Energy Technology Data Exchange (ETDEWEB)

    Reilkoff, T. E.; Hetland, M. D.; O' Leary, E. M.

    2002-02-25

    The Deactivation and Decommissioning Focus Area's (DDFA's) mission is to develop, demonstrate, and deploy improved deactivation and decommissioning (D&D) technologies. This mission requires that emphasis be continually placed on identifying technologies currently employed or under development in other nuclear as well as nonnuclear industries and government agencies. In support of DDFA efforts to clean up the U.S. Department of Energy's (DOE's) radiologically contaminated surplus facilities using technologies that improve worker safety, reduce costs, and accelerate cleanup schedules, a study was conducted to identify innovative technologies developed for use in nonnuclear arenas that are appropriate for D&D applications.

  5. A Novel Approach for Prediction of Industrial Catalyst Deactivation Using Soft Sensor Modeling

    Directory of Open Access Journals (Sweden)

    Hamed Gharehbaghi

    2016-06-01

    Full Text Available Soft sensors are used for fault detection and prediction of the process variables in chemical processing units, for which the online measurement is difficult. The present study addresses soft sensor design and identification for deactivation of zeolite catalyst in an industrial-scale fixed bed reactor based on the process data. The two main reactions are disproportionation (DP and transalkylation (TA, which change toluene and C9 aromatics into xylenes and benzene. Two models are considered based on the mass conservation around the reactor. The model parameters are estimated by data-based modeling (DBM philosophy and state dependent parameter (SDP method. In the SDP method, the parameters are assumed to be a function of the system states. The results show that the catalyst activity during the period under study has approximately a monotonic trend. Identification of the system clearly shows that the xylene concentration has a determining role in the conversion of reactions. The activation energies for both DP and TA reactions are found to be 43.8 and 18 kJ/mol, respectively. The model prediction is in good agreement with the observed industrial data.

  6. Deactivation of carbon supported palladium catalyst in direct formic acid fuel cell

    International Nuclear Information System (INIS)

    A new carbon black supported palladium catalyst for direct formic acid fuel cell applications has been prepared and characterized by X-ray diffraction. Bi-modal distribution of Pd crystallite sizes was observed. The average Pd size for crystallites in small size and large size ranges were about 2.7 nm and 11.2 nm, respectively. The initial activity of the catalyst in the oxidation of formic acid tested in a fuel cell was similar to a commercial well dispersed 20 wt.% Pd/Vulcan. The rates of the fuel cell power decay were measured for formic acid of two purities for various current loadings. The results showed that various mechanisms contribute to the decrease of cell power with time. In direct formic acid fuel cell (DFAFC) fed with a very pure HCOOH accumulation of CO2 gas bubbles in anode catalyst layer is responsible for observed power decay. In DFAFC fed with a pure for analysis (p.a.) grade formic acid the formation of COads poison from the formic acid impurities is the main deactivation reason.

  7. Catalyst activation, deactivation, and degradation in palladium-mediated Negishi cross-coupling reactions.

    Science.gov (United States)

    Böck, Katharina; Feil, Julia E; Karaghiosoff, Konstantin; Koszinowski, Konrad

    2015-03-27

    Pd-mediated Negishi cross-coupling reactions were studied by a combination of kinetic measurements, electrospray-ionization (ESI) mass spectrometry, (31)P NMR and UV/Vis spectroscopy. The kinetic measurements point to a rate-determining oxidative addition. Surprisingly, this step seems to involve not only the Pd catalyst and the aryl halide substrate, but also the organozinc reagent. In this context, the ESI-mass spectrometric observation of heterobimetallic Pd-Zn complexes [L2 PdZnR](+) (L=S-PHOS, R=Bu, Ph, Bn) is particularly revealing. The inferred presence of these and related neutral complexes with a direct Pd-Zn interaction in solution explains how the organozinc reagent can modulate the reactivity of the Pd catalyst. Previous theoretical calculations by González-Pérez et al. (Organometallics- 2012, 31, 2053) suggest that the complexation by the organozinc reagent lowers the activity of the Pd catalyst. Presumably, a similar effect also causes the rate decrease observed upon addition of ZnBr2 . In contrast, added LiBr apparently counteracts the formation of Pd-Zn complexes and restores the high activity of the Pd catalyst. At longer reaction times, deactivation processes due to degradation of the S-PHOS ligand and aggregation of the Pd catalyst come into play, thus further contributing to the appreciable complexity of the title reaction. PMID:25709062

  8. A Cobalt Hydride Catalyst for the Hydrogenation of CO2: Pathways for Catalysis and Deactivation

    Energy Technology Data Exchange (ETDEWEB)

    Jeletic, Matthew S.; Helm, Monte L.; Hulley, Elliott B.; Mock, Michael T.; Appel, Aaron M.; Linehan, John C.

    2014-10-03

    The complex Co(dmpe)₂H catalyzes the hydrogenation of CO₂ at one atm and 21 ºC with significant improvement in turnover frequency relative to previously reported second and third row transition metal complexes. New studies are presented to elucidate the catalytic mechanism as well as pathways for catalyst deactivation. The catalytic rate was optimized through the choice of the base to match the pKa of the [Co(dmpe)₂(H)₂]⁺ intermediate. By using a strong enough base, the catalytic rate has a zero order dependence on the concentration of base and pressure of hydrogen, and a first order dependence on the pressure of CO₂. However, upon exceeding CO₂:H₂ ratios of greater than one, the catalytically inactive species [(μ-dmpe)(Co(dmpe)₂)₂]²⁺ and [Co(dmpe)₂CO]⁺ are observed. Research by M.S.J., M.T.M., A.M.A., and J.C.L. was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Research by M.L.H. and E.B.H. was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for the DOE by Battelle.

  9. Supplementary motor area deactivation impacts the recovery of hand function from severe peripheral nerve injury

    Institute of Scientific and Technical Information of China (English)

    Ye-chen Lu; Han-qiu Liu; Xu-yun Hua; Yun-dong Shen; Wen-dong Xu; Jian-guang Xu; Yu-dong Gu

    2016-01-01

    Although some patients have successful peripheral nerve regeneration, a poor recovery of hand function often occurs after peripheral nerve injury. It is believed that the capability of brain plasticity is crucial for the recovery of hand function. The supplementary motor area may play a key role in brain remodeling after peripheral nerve injury. In this study, we explored the activation mode of the supplementary motor area during a motor imagery task. We investigated the plasticity of the central nervous system after brachial plexus injury, using the motor imagery task. Results from functional magnetic resonance imaging showed that after brachial plexus injury, the motor imagery task for the affected limbs of the patients triggered no obvious activation of bilateral supplementary motor areas. This result indicates that it is dififcult to excite the supplementary motor areas of brachial plexus injury patients during a motor imagery task, thereby impacting brain remodeling. Deactivation of the supplementary motor area is likely to be a serious problem for brachial plexus injury patients in terms of preparing, initiating and executing certain movements, which may be partly responsible for the unsatisfactory clinical recovery of hand function.

  10. Nonlinear analysis and modeling of cortical activation and deactivation patterns in the immature fetal electrocorticogram

    Science.gov (United States)

    Schwab, Karin; Groh, Tobias; Schwab, Matthias; Witte, Herbert

    2009-03-01

    An approach combining time-continuous nonlinear stability analysis and a parametric bispectral method was introduced to better describe cortical activation and deactivation patterns in the immature fetal electroencephalogram (EEG). Signal models and data-driven investigations were performed to find optimal parameters of the nonlinear methods and to confirm the occurrence of nonlinear sections in the fetal EEG. The resulting measures were applied to the in utero electrocorticogram (ECoG) of fetal sheep at 0.7 gestation when organized sleep states were not developed and compared to previous results at 0.9 gestation. Cycling of the nonlinear stability of the fetal ECoG occurred already at this early gestational age, suggesting the presence of premature sleep states. This was accompanied by cycling of the time-variant biamplitude which reflected ECoG synchronization effects during premature sleep states associated with nonrapid eye movement sleep later in gestation. Thus, the combined nonlinear and time-variant approach was able to provide important insights into the properties of the immature fetal ECoG.

  11. Activation and deactivation of neutral palladium(II) phosphinesulfonato polymerization catalysts

    KAUST Repository

    Rünzi, Thomas

    2012-12-10

    13C-Labeled ethylene polymerization (pre)catalysts [κ2-(anisyl)2P,O]Pd(13CH3)(L) (1-13CH3-L) (L = pyridine, dmso) based on di(2-anisyl)phosphine benzenesulfonate were used to assess the degree of incorporation of 13CH3 groups into the formed polyethylenes. Polymerizations of variable reaction time reveal that ca. 60-85% of the 13C-label is found in the polymer after already 1 min polymerization time, which provides evidence that the pre-equilibration between the catalyst precursor 1-13CH3-L and the active species 1-13CH3-(ethylene) is fast with respect to chain growth. The fraction of 1-13CH3-L that initiates chain growth is likely higher than the 60-85% determined from the 13C-labeled polymer chain ends since (a) chain walking results in in-chain incorporation of the 13C-label, (b) irreversible catalyst deactivation by formation of saturated (and partially volatile) alkanes diminishes the amount of 13CH3 groups incorporated into the polymer, and (c) palladium-bound 13CH3 groups, and more general palladium-bound alkyl(polymeryl) chains, partially transfer to phosphorus by reductive elimination. NMR and ESI-MS analyses of thermolysis reactions of 1-13CH3-L provide evidence that a mixture of phosphonium salts (13CH3)xP+(aryl)4-x (2-7) is formed in the absence of ethylene. In addition, isolation and characterization of the mixed bis(chelate) palladium complex [κ2-(anisyl)2P,O]Pd[κ2-(anisyl) (13CH3)P,O] (11) by NMR and X-ray diffraction analyses from these mixtures indicate that oxidative addition of phosphonium salts to palladium(0) species is also operative. The scrambling of palladium-bound carbyls and phosphorus-bound aryls is also relevant under NMR, as well as preparative reactor polymerization conditions exemplified by the X-ray diffraction analysis of [κ2-(anisyl)2P,O] Pd[κ2-(anisyl)(CH2CH3)P,O] (12) and [κ2-(anisyl)2P,O]Pd[κ2-(anisyl) ((CH2)3CH3)P,O] (13) isolated from pressure reactor polymerization experiments. In addition, ESI-MS analyses of reactor

  12. Improving the Identification, Dissemination and Implementation of Deactivation and Decommissioning Lessons Learned and Best Practices

    International Nuclear Information System (INIS)

    Approximately $150 billion of work currently remains in the United States Department of Energy's (DoE's) Office of Environmental Management (EM) life cycle budget for U.S. projects. Contractors who manage facilities for the DOE have been challenged to identify transformational changes to reduce the life cycle costs and to develop a knowledge-management system that identifies, disseminates, and tracks the implementation of lessons learned and best practices. This paper discusses DoE's rationale for using lessons learned and best practices to improve safety and performance while reducing life cycle costs for Deactivation and Decommissioning (D and D) projects. It also provides an update on the Energy Facility Contractors Group's (EFCOG's) progress in supporting DoE's efforts. At this juncture the best practice efforts described are in developmental stages; however, the commitment to and the concrete nature of the work thus far is noteworthy in regard to improving the way D and D lessons learned and best practices are identified, disseminated and implemented across the DOE Complex

  13. [Application of deactivating properties of some sorbents in aquaculture feed production].

    Science.gov (United States)

    Vasukevich, T A; Nitievskaya, L S

    2014-01-01

    The possibility and effectiveness of application of selective sorbents for fish feed production in aquaculture in the area exposed to the radioactive pollution were studied. The investigations of the fish feed deactivating properties with additives of ferrocyn and potassium alginate, and magnesium on whitefish fry-fingerlings and yearlings were carried out. The study has shown that the ferrocyn performance is greater than 99% regardless of the fish age. 1% ferrocyn addition to feed allows increasing the acceptable concentration of feed compo- nents polluted by the above norm cesium radionuclide up to 20 times. The alginate additives in feed provide almost double decrease in the activity of fish tissues. The optimally effective alginate dose should exceed the calcium concentration in feed up to 4 times. It was found that utilization of the feedstock (fish meal, crops and legumes, oil meal and oil cake) polluted by radionuclides is possible in combined aquaculture feed pro- duction. The application of sorbents in feed will allow increasing the amount permissible for use of the feed components polluted above the norm; ensure the radiation safety of feed and, finally, the protection of aquatic biological resources from radioactive contamination. It is shown that the sorbent additive in feed is also jus- tified in case of fish farming in closed waters affected by radioactive pollution. Feeding by mixed fodder with the sorbent additives prevents fish from radionuclide intake from natural food sources. PMID:25980288

  14. Catabolism and Deactivation of the Lipid-derived Hormone Jasmonoyl-isoleucine

    Directory of Open Access Journals (Sweden)

    Abraham JK Koo

    2012-02-01

    Full Text Available The oxylipin hormone jasmonate controls myriad processes involved in plant growth, development and immune function. The discovery of jasmonoyl-L-isoleucine (JA-Ile as the major bioactive form of the hormone highlights the need to understand biochemical and cell biological processes underlying JA-Ile homeostasis. Among the major metabolic control points governing the accumulation of JA-Ile in plant tissues are the availability of jasmonic acid, the immediate precursor of JA-Ile, and oxidative enzymes involved in catabolism and deactivation of the hormone. Recent studies indicate that JA-Ile turnover is mediated by a ω-oxidation pathway involving members of the CYP94 family of cytochromes P450. This discovery opens new opportunities to genetically manipulate JA-Ile levels for enhanced resistance to environmental stress, and further highlights ω-oxidation as a conserved pathway for catabolism of lipid-derived signals in plants and animals. Functional characterization of the full complement of CYP94 P450s promises to reveal new pathways for jasmonate metabolism and provide insight into the evolution of oxylipin signaling in land plants.

  15. Field Dependent Dopant Deactivation in Bipolar Devices at Elevated irradiation Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    WITCZAK,STEVEN C.; LACOE,RONALD C.; SHANEYFELT,MARTY R.; MAYER,DONALD C.; SCHWANK,JAMES R.; WINOKUR,PETER S.

    2000-08-15

    Metal-oxide-silicon capacitors fabricated in a bi-polar process were examined for densities of oxide trapped charge, interface traps and deactivated substrate acceptors following high-dose-rate irradiation at 100 C. Acceptor neutralization near the Si surface occurs most efficiently for small irradiation biases in depletion. The bias dependence is consistent with compensation and passivation mechanisms involving the drift of H{sup +} ions in the oxide and Si layers and the availability of holes in the Si depletion region. Capacitor data from unbiased irradiations were used to simulate the impact of acceptor neutralization on the current gain of an npn bipolar transistor. Neutralized acceptors near the base surface enhance current gain degradation associated with radiation-induced oxide trapped charge and interface traps by increasing base recombination. The additional recombination results from the convergence of carrier concentrations in the base and increased sensitivity of the base to oxide trapped charge. The enhanced gain degradation is moderated by increased electron injection from the emitter. These results suggest that acceptor neutralization may enhance radiation-induced degradation of linear circuits at elevated temperatures.

  16. Theroa zethus Caterpillars Use Acid Secretion of Anti-Predator Gland to Deactivate Plant Defense.

    Directory of Open Access Journals (Sweden)

    David E Dussourd

    Full Text Available In North America, notodontid caterpillars feed almost exclusively on hardwood trees. One notable exception, Theroa zethus feeds instead on herbaceous plants in the Euphorbiaceae protected by laticifers. These elongate canals follow leaf veins and contain latex under pressure; rupture causes the immediate release of sticky poisonous exudate. T. zethus larvae deactivate the latex defense of poinsettia and other euphorbs by applying acid from their ventral eversible gland, thereby creating furrows in the veins. The acid secretion softens the veins allowing larvae to compress even large veins with their mandibles and to disrupt laticifers internally often without contacting latex. Acid secretion collected from caterpillars and applied to the vein surface sufficed to create a furrow and to reduce latex exudation distal to the furrow where T. zethus larvae invariably feed. Larvae with their ventral eversible gland blocked were unable to create furrows and suffered reduced growth on poinsettia. The ventral eversible gland in T. zethus and other notodontids ordinarily serves to deter predators; when threatened, larvae spray acid from the gland orifice located between the mouthparts and first pair of legs. To my knowledge, T. zethus is the first caterpillar found to use an antipredator gland for disabling plant defenses. The novel combination of acid application and vein constriction allows T. zethus to exploit its unusual latex-bearing hosts.

  17. [Application of deactivating properties of some sorbents in aquaculture feed production].

    Science.gov (United States)

    Vasukevich, T A; Nitievskaya, L S

    2014-01-01

    The possibility and effectiveness of application of selective sorbents for fish feed production in aquaculture in the area exposed to the radioactive pollution were studied. The investigations of the fish feed deactivating properties with additives of ferrocyn and potassium alginate, and magnesium on whitefish fry-fingerlings and yearlings were carried out. The study has shown that the ferrocyn performance is greater than 99% regardless of the fish age. 1% ferrocyn addition to feed allows increasing the acceptable concentration of feed compo- nents polluted by the above norm cesium radionuclide up to 20 times. The alginate additives in feed provide almost double decrease in the activity of fish tissues. The optimally effective alginate dose should exceed the calcium concentration in feed up to 4 times. It was found that utilization of the feedstock (fish meal, crops and legumes, oil meal and oil cake) polluted by radionuclides is possible in combined aquaculture feed pro- duction. The application of sorbents in feed will allow increasing the amount permissible for use of the feed components polluted above the norm; ensure the radiation safety of feed and, finally, the protection of aquatic biological resources from radioactive contamination. It is shown that the sorbent additive in feed is also jus- tified in case of fish farming in closed waters affected by radioactive pollution. Feeding by mixed fodder with the sorbent additives prevents fish from radionuclide intake from natural food sources.

  18. Deactivation of excitation energy in bacterial photosynthetic reaction centres in Langmuir-Blodgett films

    Science.gov (United States)

    Miyake, J.; Hara, M.; Goc, J.; Planner, A.; Wróbel, D.

    1997-08-01

    Absorption, photoacoustic and time-resolved in μs time range delayed luminescence spectra have been measured in order to follow the interaction among chromophores when Rhodobacter sphaeroides and Rhodopseudomonas viridis reaction centres are closely packed in a form of Langmuir-Blodgett multilayers. Two types of Langmuir-Blodgett samples have been prepared and investigated: multilayers consist of one type of reaction centre ( Rhodobacter sphaeroides or Rhodopseudomonas viridis) and multilayers composed of mixed reaction centres ( Rhodobacter sphaeroides mixed with Rhodopseudomonas viridis). Using the Langmuir-Blodgett multilayers composed of two types of bacteria reaction centres mixture, we were able to extend the spectral region of the light/solar energy absorbed by the system. It was shown that each form of pigment participates in thermal dissipation but to a different degree. A special pair (bacteriochlorophyll dimer) does not contribute to delayed luminescence. Delayed luminescence in Rhodopseudomonas viridis and Rhodobacter sphaeroides differs very significantly from each other. Bacteriopheophytin as well as dihydromesochlorophyll contribute to delayed luminescence but the degree of their participation in this radiative process depends strongly on the type of reaction centre. Delayed luminescence and thermal processes have been indicated as important processes of deactivation of the photoexcited chromophores in reaction centres.

  19. Thermal stability and energy of deactivation of free and immobilized cellobiase

    Directory of Open Access Journals (Sweden)

    L.P.V. Calsavara

    2000-12-01

    Full Text Available Commercial cellobiase has been immobilized in controlled pore silica particles by covalent binding with the silane-glutaraldehyde method with protein and activity yields of 67% and 13.7%, respectively. Thermal stability of the free and immobilized enzyme (IE was determined with 0.2% w/v cellobiose solution, pH 4.8, temperatures from 40 to 70°C for free enzyme and 40 to 75°C for IE. Free cellobiase maintained its activity practically constant for 240 min at temperatures up to 55°C. The IE has shown higher stability retaining its activity in the same test up to 60° C. Half-lives for free enzyme were 14.1, 2.1 and 0.17 h at 60, 65 and 70°C, respectively, whereas the IE at the same temperatures had half-lives of 245, 21.3 and 2.9 h. The energy of thermal deactivation was 80.6 kcal/mol for the free enzyme and 85.2 kcal/mol for the IE, confirming stabilization by immobilization.

  20. Enhanced sympathetic arousal in response to FMRI scanning correlates with task induced activations and deactivations.

    Directory of Open Access Journals (Sweden)

    Markus Muehlhan

    Full Text Available It has been repeatedly shown that functional magnetic resonance imaging (fMRI triggers distress and neuroendocrine response systems. Prior studies have revealed that sympathetic arousal increases, particularly at the beginning of the examination. Against this background it appears likely that those stress reactions during the scanning procedure may influence task performance and neural correlates. However, the question how sympathetic arousal elicited by the scanning procedure itself may act as a potential confounder of fMRI data remains unresolved today. Thirty-seven scanner naive healthy subjects performed a simple cued target detection task. Levels of salivary alpha amylase (sAA, as a biomarker for sympathetic activity, were assessed in samples obtained at several time points during the lab visit. SAA increased two times, immediately prior to scanning and at the end of the scanning procedure. Neural activation related to motor preparation and timing as well as task performance was positively correlated with the first increase. Furthermore, the first sAA increase was associated with task induced deactivation (TID in frontal and parietal regions. However, these effects were restricted to the first part of the experiment. Consequently, this bias of scanner related sympathetic activation should be considered in future fMRI investigations. It is of particular importance for pharmacological investigations studying adrenergic agents and the comparison of groups with different stress vulnerabilities like patients and controls or adolescents and adults.

  1. Hydrogenation of xylose to xylitol on sponge nickel catalyst: a study of the process and catalyst deactivation kinetics

    OpenAIRE

    Mikkola J.-P.; Salmi T.; Villela A.; Vainio H.; Mäki-Arvela P.; Kalantar A.; Ollonqvist T.; Väyrynen J.; Sjöholm R.

    2003-01-01

    The kinetics of hydrogenation of xylose to xylitol on a sponge nickel catalyst (commonly referred to as Raney Ni catalyst) and of catalyst deactivation were studied. Plausible explanations for the decrease in catalytic activity by means of surface studies, nitrogen adsorption and thermogravimetric analyses of the fresh and spent catalysts are presented. The kinetic parameters of the process were estimated by the use of a semi-competitive model, which allows full competition between the organi...

  2. The S4-S5 linker acts as a signal integrator for HERG K+ channel activation and deactivation gating.

    Science.gov (United States)

    Ng, Chai Ann; Perry, Matthew D; Tan, Peter S; Hill, Adam P; Kuchel, Philip W; Vandenberg, Jamie I

    2012-01-01

    Human ether-à-go-go-related gene (hERG) K(+) channels have unusual gating kinetics. Characterised by slow activation/deactivation but rapid inactivation/recovery from inactivation, the unique gating kinetics underlie the central role hERG channels play in cardiac repolarisation. The slow activation and deactivation kinetics are regulated in part by the S4-S5 linker, which couples movement of the voltage sensor domain to opening of the activation gate at the distal end of the inner helix of the pore domain. It has also been suggested that cytosolic domains may interact with the S4-S5 linker to regulate activation and deactivation kinetics. Here, we show that the solution structure of a peptide corresponding to the S4-S5 linker of hERG contains an amphipathic helix. The effects of mutations at the majority of residues in the S4-S5 linker of hERG were consistent with the previously identified role in coupling voltage sensor movement to the activation gate. However, mutations to Ser543, Tyr545, Gly546 and Ala548 had more complex phenotypes indicating that these residues are involved in additional interactions. We propose a model in which the S4-S5 linker, in addition to coupling VSD movement to the activation gate, also contributes to interactions that stabilise the closed state and a separate set of interactions that stabilise the open state. The S4-S5 linker therefore acts as a signal integrator and plays a crucial role in the slow deactivation kinetics of the channel.

  3. Selective Deactivation of Gibberellins below the Shoot Apex is Critical to Flowering but Not to Stem Elongation of Lolium

    Institute of Scientific and Technical Information of China (English)

    Rod W.King; Lewis N.Mander; Torben Asp; Colleen P. MacMillan; Cheryl A.Blundell; Lloyd T.Evans

    2008-01-01

    Gibberellins (GAs) cause dramatic increases in plant height and a genetic block in the synthesis of GA1 explains the dwarfing of Mendel's pea.For flowering,it is GAs which is important in the long-day (LD) responsive grass,Lolium.As we show here,GA1 and GA4 are restricted in their effectiveness for flowering because they are deactivated by C-2 hydroxylation below the shoot apex.In contrast,GAs is effective because of its structural protection at C-2.Excised vegetative shoot tips rapidly degrade [14C]GA1,[14C]GA4,and [14C]GA20 (>80% in 6 h),but not [14C]GA5.Coincidentally,genes encoding two 2β-oxidases and a putative 16-17-epoxidase were most expressed just below the shoot apex (4 mm),expression of these GA deactivation genes is reduced,so allowing GA1 and GA4 to promote sub-apical stem elongation.Subsequently,GA degradation declines in florally induced shoot tips and these GAs can become active for floral development.Structural changes which stabilize GA4 confirm the link between florigenicity and restricted GA 2β-hydroxylation (e.g.2α-hydroxylation and C-2 di-methylation).Additionally,a 2-oxidase inhibitor (Trinexapac Ethyl) enhanced the activity of applied GA4,as did limiting C-16,17 epoxidation in 16,17-dihydro GAs or after C-13 hydroxylation.Overall,deactivation of GA1 and GA4 just below the shoot apex effectively restricts their florigenicity in Lolium and,conversely,with GAs,C-2 and C-13 protection against deactivation allows its high florigenicity.Speculatively,such differences in GA access to the shoot apex of grasses may be important for separating floral induction from inflorescence emergence and thus could influence their survival under conditions of herbivore predation.

  4. Final deactivation report on the tritium target facility, Building 7025, at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-08-01

    This report includes a history and profile of Bldg. 7025 before and after completion of deactivation. It also discusses turnover items, such as the Postdeactivation Surveillance & Maintenance Plan, remaining hazardous materials, radiological controls, Safeguards and Security, quality assurance, facility operations, and supporting documentation in the EM-60 Turnover package. Other than minimal S&M activities, the building will be unoccupied and the exterior doors locked (access only for the required S&M).

  5. Maquet Vasoview Hemopro VH-3000 vessel harvesting system may self-activate or fail to deactivate, potentially resulting in injury.

    Science.gov (United States)

    2011-05-01

    The Harvesting Tool component of the Maquet Vasoview Hemopro VH-3000 vessel harvesting system may self-activate or may fail to deactivate, increasing the chance of thermal injury to the patient or staff, or of igniting a fire. Users of this product must be aware of the potential for either of the unintended activation problems to occur and must be familiar with Maquet's recommendations for dealing with the issue, which are provided in the system's instructions for use.

  6. Fuel Efficiency Mapping of a 2014 6-Cylinder GM EcoTec 4.3L Engine with Cylinder Deactivation (SAE 2016-01-0662)

    Science.gov (United States)

    This paper describes the method and test results of the engine dyno portion of the benchmarking test results including engine fuel consumption maps showing the effects of cylinder deactivation engine technology.

  7. Uncovering the deactivation mechanism of Au catalyst with operando high spatial resolution IR and X-ray microspectroscopy measurements

    Science.gov (United States)

    Gross, Elad

    2016-06-01

    Detecting the reaction mechanism of multistep catalytic transformations is essential for optimization of these complex processes. In this study, the mechanism of catalyst deactivation within a flow reactor was studied under reaction conditions. Spectral mapping of the catalyst and the organic phase along a flow reactor were performed with micrometer-sized synchrotron-based X-ray and IR beams, respectively, with a spatial resolution of 15 μm. Heterogeneous Au catalyst was packed in a flow reactor and activated toward the cascade reaction of pyran formation. X-ray absorption microspectroscopy measurements revealed that the highly oxidized Au(III), which is the catalytically active species, was continuously reduced along the flow reactor. IR microspectroscopy measurements detected a direct correlation between the reduction of the Au catalyst and deactivation of the catalytic process. It was observed that within 1.5 mm from the reactor's inlet all the catalytic reactivity was quenched. Microspectroscopy measurements determined that the reduction of Au(III) was induced by nucleophilic attack of butanol, which is one of the reactants in this reaction. Slower deactivation rates were measured once the reactants concentration was decreased by an order of magnitude. Under these conditions the reaction path within the flow reactor was increased from 1.5 to 6 mm. These results demonstrate the molecular level understanding of reaction mechanism which can be achieved by high spatial resolution microspectroscopy measurements.

  8. Kinetic study of propane dehydrogenation and catalyst deactivation over Pt-Sn/Al2O3 catalyst

    Institute of Scientific and Technical Information of China (English)

    Farnaz; Tahriri; Zangeneh; Abbas; Taeb; Khodayar; Gholivand; Saeed; Sahebdelfar

    2013-01-01

    The kinetics of propane dehydrogenation and catalyst deactivation over Pt-Sn/Al2O3 catalyst were studied.Performance test runs were carried out in a fixed-bed integral reactor.Using a power-law rate expression for the surface reaction kinetics and independent law for deactivation kinetics,the experimental data were analyzed both by integral and a novel differential method of analysis and the results were compared.To avoid fluctuation of time-derivatives of conversion required for differential analysis,the conversion-time data were first fitted with appropriate functions.While the time-zero and rate constant of reaction were largely insensitive to the function employed,the rate constant of deactivation was much more sensitive to the function form.The advantage of the proposed differential method,however,is that the integration of the rate expression is not necessary which otherwise could be complicated or impossible.It was also found that the reaction is not limited by external and internal mass transfer limitations,implying that the employed kinetics could be considered as intrinsic ones.

  9. Deactivation and cleanout of the 308 Fuels Laboratory and the 232-Z Incinerator at the Hanford site

    International Nuclear Information System (INIS)

    This paper describes the deactivation and source term reduction activities conducted over the recent past in two plutonium-contaminated Hanford Site buildings: the 308 Fuels Development Laboratory and the 232-Z Incinerator. Both of these facilities belong to the U.S. Department of Energy, and the projects are unique success stories carried out in direct support of EM-60 functions and requirements. In both cases the buildings, for different reasons, contained unacceptable amounts of plutonium, and were stabilized and placed in a safe, pre-D ampersand D (decontamination and decommissioning) mode. The concept of deactivation as the last step in the operating life of a facility will be discussed. The need for and requirements of EM-60 transition between operations and D ampersand D, the costs savings, techniques, regulations and lessons learned also will be discussed. This paper describes the strategies that led to successful source term reduction: accurate characterization, cooperation among different divisions within DOE and the Hanford Site, attention to regulations (especially unique in this case since the 232-Z Incinerator has been nominated as a Historic Structure to the National Register of Historic Places), and stakeholder concerns involving the proximity of the 308 Building to the Columbia River. The paper also weaves in the history, missions, and plutonium accumulation of the two buildings. The lessons learned are cogent to many other present and future deactivation activities across the DOE complex and indeed across the world

  10. Emotional and cognitive processing of narratives and individual appraisal styles: recruitment of cognitive control networks vs. modulation of deactivations

    Directory of Open Access Journals (Sweden)

    Enrico eBenelli

    2012-08-01

    Full Text Available Research in psychotherapy has shown that the frequency of use of specific classes of words (such as terms with emotional valence in descriptions of scenes of affective relevance is a possible indicator of psychological affective functioning. Using functional magnetic resonance imaging, we investigated the neural correlates of these linguistic markers in narrative texts depicting core aspects of emotional experience in human interaction, and their modulation by individual differences in the propensity to use these markers. Emotional words activated both lateral and medial aspects of the prefrontal cortex, as in previous studies of instructed emotion regulation and in consistence with recruitment of effortful control processes. However, individual differences in the spontaneous use of emotional terms in characterizing the stimulus material were prevalently associated with modulation of the signal in the perigenual cortex, in the retrosplenial cortex and precuneus, and the anterior insula/ventrolateral prefrontal cortex. Modulation of signal by the presence of these textual markers or individual differences mostly involved areas deactivated by the main task, thus further differentiating neural correlates of these appraisal styles from those associated with effortful control. These findings are discussed in the context of reports in the literature of modulations of deactivations, which suggest their importance in orienting attention and generation of response in the presence of emotional information. These findings suggest that deactivations may play a functional role in emotional appraisal and may contribute to characterizing different appraisal styles.

  11. Ligand-specific Deactivation Time Course of GluN1/GluN2D NMDA Receptors

    Energy Technology Data Exchange (ETDEWEB)

    K Vance; N Simorowski; S Traynelis; H Furukawa

    2011-12-31

    N-methyl-D-aspartate (NMDA) receptors belong to the family of ionotropic glutamate receptors that mediate a majority of excitatory synaptic transmission. One unique property of GluN1/GluN2D NMDA receptors is an unusually prolonged deactivation time course following the removal of L-glutamate. Here we show, using x-ray crystallography and electrophysiology, that the deactivation time course of GluN1/GluN2D receptors is influenced by the conformational variability of the ligand-binding domain (LBD) as well as the structure of the activating ligand. L-glutamate and L-CCG-IV induce significantly slower deactivation time courses compared with other agonists. Crystal structures of the isolated GluN2D LBD in complex with various ligands reveal that the binding of L-glutamate induces a unique conformation at the backside of the ligand-binding site in proximity to the region at which the transmembrane domain would be located in the intact receptors. These data suggest that the activity of the GluN1/GluN2D NMDA receptor is controlled distinctively by the endogenous neurotransmitter L-glutamate.

  12. Swatara Creek basin of southeastern Pennsylvania--An evaluation of its hydrologic system

    Science.gov (United States)

    Stuart, Wilbur Tennant; Schneider, William J.; Crooks, James W.

    1967-01-01

    Local concentrations of population in the Swatara Creek basin of Pennsylvania find it necessary to store, transport, and treat water because local supplies are either deficient or have been contaminated by disposal of wastes in upstream areas. Water in the basin is available for the deficient areas and for dilution of the coal-mine drainage in the northern parts and the sewage wastes in the southern parts.

  13. Effect of Au nano-particle aggregation on the deactivation of the AuCl3/AC catalyst for acetylene hydrochlorination

    OpenAIRE

    Bin Dai; Qinqin Wang; Feng Yu; Mingyuan Zhu

    2015-01-01

    A detailed study of the valence state and distribution of the AuCl3/AC catalyst during the acetylene hydrochlorination deactivation process is described and discussed. Temperature-programmed reduction and X-ray photoelectron spectral analysis indicate that the active Au3+ reduction to metallic Au0 is one reason for the deactivation of AuCl3/AC catalyst. Transmission electron microscopy characterization demonstrated that the particle size of Au nano-particles increases with increasing reaction...

  14. Probing the Mechanism of the Double C—H (De)Activation Route of a Ru-Based Olefin Metathesis Catalyst

    Science.gov (United States)

    Poater, Albert; Cavallo, Luigi

    A theoretical study of a double C—H activation mechanism that deactivates a family of second generation Ru-based catalysts is presented. DFT calculations are used to rationalize the complex mechanistic pathway from the starting precatalyst to the experimentally characterized decomposition products. In particular, we show that all the intermediates proposed by Grubbs and coworkers are indeed possible intermediates in the deactivation pathway, although the sequence of steps is somewhat different

  15. Deactivation Mechanism for COS Hydrolysis over TGH Catalyst--FT-IR Study of the Adsorption Behavior of COS, O2 and H2S

    Institute of Scientific and Technical Information of China (English)

    Meisheng Liang; Chunhu Li; Hanxian Guo; Kechang Xie

    2002-01-01

    The adsorptions of COS, H2S and O2 were investigated over the TGH catalyst in this paper.It was found that the numbers of basic centers and basic intensities were reduced over the deactivated TGH catalyst. The FT-IR results of COS+H2S+O2 co-adsorption on the TGH catalyst show that the main causes of catalyst deactivation is the formation of element sulfur and trace sulfate.

  16. The 1.4-l TSI gasoline engine with cylinder deactivation; Der 1,4-L-TSI-Ottomotor mit Zylinderabschaltung

    Energy Technology Data Exchange (ETDEWEB)

    Middendorf, Hermann; Theobald, Joerg; Lang, Leonhard [Volkswagen AG, Wolfsburg (Germany). Bereich Ottomotoren; Hartel, Kai [Volkswagen AG, Salzgitter (Germany). Geschaeftsfeld Komponente Motor

    2012-03-15

    A very promising route to the reduction of fuel consumption that has been little trod thus far is that of cylinder deactivation under partial load. The new 1.4 TSI with petrol direct injection and turbocharging was selected for the first application of this technology in a Volkswagen four-cylinder in-line engine. Within the appropriate map area, the actuation of the inlet and exhaust valves on cylinders 2 and 3 is deactivated and fuel injection shut off. (orig.)

  17. Deactivation of V2O5-WO3-TiO2 SCR catalyst at a biomass-fired combined heat and power plant

    DEFF Research Database (Denmark)

    Zheng, Yuanjing; Jensen, Anker; Johnsson, Jan Erik

    2005-01-01

    The deactivation of a commercial type V2O5-WO3-TiO2 monolith catalyst under biomass combustion was studied at a full-scale grate-fired power plant burning straw/wood using a slip stream pilot scale reactor. The aerosols in the flue gas consisted of a mixture of potassium chloride and sulphate. Th...... though reactivation is possible, the deactivation rate appears too high for practical use of the SCR process in straw combustion....

  18. Seepage basin radionuclide transport in sediments and vegetation

    International Nuclear Information System (INIS)

    Radionuclide concentrations were measured in soil and vegetation growing adjacent to and in the Savannah River Laboratory Seepage Basins as part of the plan for closure of the basin system. The results of the measurements provide some information about the mobility of the radionuclides introduced into the basins. 90Sr is the most mobile of the radionuclides in soil. Its high mobility and high relative uptake by vegetation cause 90Sr to be distributed throughout the basin system. 137Cs is not as mobile in the basin soil, limiting its uptake by vegetation growing on the edge of the seepage basins; however, it is readily taken up by the vegetation growing in the basins. Soil mobility and vegetation uptake is relatively low for all of the transuranic radionuclides. For the most part these radionuclides remain near the surface of the basin soils where they were absorbed from the waste-water. The relative role of soil mobility and vegetation uptake on the distribution of radionuclide at the basins was futher evaluated by comparing the vegetation concentration ratio and the half-depth of penetration of the radionuclides in the basin soil. The results suggest that vegetation processes dominate in determining the concentration of 60Co and 137Cs in the vegetation. The influences of soil and vegetation are more balanced for 90Sr. The other radionuclides exhibit both low soil mobility and low vegetation uptake. The lack of soil mobility is seen in the lower concentrations found in vegetation growing on the edge of the basin compared to those growing in the basin

  19. Hydrogeology of the West Siberian Basin

    International Nuclear Information System (INIS)

    Nuclear fuel cycle activities of the former Soviet Union (FSU) have resulted in significant contamination of the environment in western Siberia. The radioactive releases to surface waters and the surficial environment from the Mayak site are the largest known in the world. However, they are dwarfed by the amounts of liquid wastes injected into the subsurface at Tomsk and Krasnoyarsk since the early 1960s. This paper provides the status of efforts by Pacific Northwest National Laboratory to quantify the regional hydrogeologic context for potential contaminant migration from areas in western Siberia. The West Siberian Basin is the largest platformal basin and region of low relief on earth. Ground water in the West Siberian Basin is contained in a single geologic structure (i.e., a single basin). Hydrogeologic cross sections indicate that freshwater wedges are present in both unconfined and confined aquifers (as well as in Paleozoic rocks) in the highland regions that rim the basin. The authors developed a 13-layer, finite-element computer model of the West Siberian Basin primarily based on GIS integration of data from geologic studies. The top of the hydrologic system was assumed to coincide with a water table derived from smoothed topography and surface-water occurrences; precipitation supplied the water, and the topographic gradient of the water table supplied the driving force for ground-water flow. The general directions of calculated ground-water flow suggest that (1) the major rivers act as discharge areas, with upwelling below the rivers extending down into the basement rocks; and (2) ground-water divides that penetrate the entire thickness of the model are evident between the major rivers. Their results suggest that contaminants entering the confined aquifer system may eventually migrate to the surface, discharging within major rivers, rather than remaining confined for long travel distances within the basin sediments

  20. Idaho Nuclear Technology and Engineering Center Newly Generated Liquid Waste Demonstration Project Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Herbst, A.K.

    2000-02-01

    A research, development, and demonstration project for the grouting of newly generated liquid waste (NGLW) at the Idaho Nuclear Technology and Engineering Center is considered feasible. NGLW is expected from process equipment waste, decontamination waste, analytical laboratory waste, fuel storage basin waste water, and high-level liquid waste evaporator condensate. The potential grouted waste would be classed as mixed low-level waste, stabilized and immobilized to meet RCRA LDR disposal in a grouting process in the CPP-604 facility, and then transported to the state.

  1. Waste management

    DEFF Research Database (Denmark)

    Bruun Hansen, Karsten; Jamison, Andrew

    2000-01-01

    The case study deals with public accountability issues connected to household waste management in the municipality of Copenhagen, Denmark.......The case study deals with public accountability issues connected to household waste management in the municipality of Copenhagen, Denmark....

  2. Food waste

    OpenAIRE

    Arazim, Lukáš

    2015-01-01

    This thesis looks into issues related to food waste and consists of a theoretical and a practical part. Theoretical part aims to provide clear and complex definition of wood waste related problems, summarize current findings in Czech and foreign sources. Introduction chapter explains important terms and legal measures related to this topic. It is followed by description of causes, implications and possibilities in food waste reduction. Main goal of practical part is analyzing food waste in Cz...

  3. Deactivating bacteria with RF Driven Hollow Slot Microplasmas in Open Air at Atmospheric Pressure

    Science.gov (United States)

    Yu, Zengqi; Pruden, Amy; Sharma, Ashish; Collins, George

    2003-10-01

    A hollow slot discharge operating in open air at atmospheric pressure has demonstrated its ability to deactivate bacterial growth on nearby surfaces exposed to the RF driven plasma. The cold plasma exits from a hollow slot with a width of 0.2 mm and variable length of 1-35 cm. An internal electrode was powered by 13.56 MHz radio-frequency power at a voltage below 200 V. External electrically grounded slots face the work piece. The plasma plume extends millimeters to centimeter beyond the hollow slot toward the work piece to be irradiated. Argon-Oxygen gas mixtures, at 33 liters per minute flow, were passed through the electrodes and the downstream plasma was employed for the process, with treatment exposure time varied from 0.06 to 0.18 seconds. Bacterial cultures were fixed to 0.22 micron cellulose filter membranes and passed under the plasma at a controlled rate at a distance of about 5-10 millimeters from the grounded slot electrode. Preliminary studies on the effectiveness of the plasma for sterilization were carried out on E. coli. Cultures were grown overnight on the membranes after exposure and the resulting colony forming units (cfu) were determined in treated and untreated groups. In the plasma treated group, a 98.2% kill rate was observed with the lowest exposure time, and increased to 99.8% when the exposure time was tripled. These studies clearly demonstrate the ability of the RF-driven hollow slot atmospheric plasma to inhibit bacterial growth on surfaces.

  4. Interpretations of de-orbit, deactivation, and shutdown guidelines applicable to GEO satellites

    Science.gov (United States)

    Honda, L.; Perkins, J.; Sun, Sheng

    As the population of space debris in orbit around the Earth grows, the probability for catastrophic collisions increases. Many agencies such as the IADC, FCC, and UN have proposed space debris mitigation guidelines or recommendations. For example, a minimum increase in perigee altitude of 235km + (1000 Cr A / m) where Cr is the solar radiation pressure coefficient, A/m is the aspect area to dry mass ratio, and 235 km is the sum of the upper altitude of the geostationary orbit (GEO) protected region (200 km) and the maximum descent of a re-orbited spacecraft due to lunar-solar & geopotential perturbations (35 km) with an eccentricity less than or equal to 0.003. While this particular recommendation is reasonably straightforward, the assumptions an operator chooses may change the result by 25 km. Other recommendations are more ambiguous. For example, once the space vehicle has been de-orbited to the required altitude, all on-board stored energy sources must be discharged by venting propellants and pressurants, discharging batteries and disabling the ability to charge them, and performing other appropriate measures. “ Vented” is not usually defined. In addition, the broadcasting capability of the spacecraft must be disabled. Boeing and its customers are working together to devise de-orbit and deactivation sequences that meet the spirit of the recommendations. This paper derives and proposes a generic minimum deorbit altitude, appropriate depletion and venting pressures based on tank design, propellant and pressurant type, and an acceptable shutdown procedure and final configuration that avoid interference with those still in the GEO belt well into the future. The goal of this paper is to open a dialogue with the global community to establish reasonable guidelines that are straightforward, safe, and achievable before an absolute requirement is set.

  5. Combined structural and functional imaging reveals cortical deactivations in grapheme-color synaesthesia

    Science.gov (United States)

    O'Hanlon, Erik; Newell, Fiona N.; Mitchell, Kevin J.

    2013-01-01

    Synaesthesia is a heritable condition in which particular stimuli generate specific and consistent sensory percepts or associations in another modality or processing stream. Functional neuroimaging studies have identified potential correlates of these experiences, including, in some but not all cases, the hyperactivation of visuotemporal areas and of parietal areas thought to be involved in perceptual binding. Structural studies have identified a similarly variable spectrum of differences between synaesthetes and controls. However, it remains unclear the extent to which these neural correlates reflect the synaesthetic experience itself or additional phenotypes associated with the condition. Here, we acquired both structural and functional neuroimaging data comparing thirteen grapheme-color synaesthetes with eleven non-synaesthetes. Using voxel-based morphometry and diffusion tensor imaging, we identify a number of clusters of increased volume of gray matter, of white matter or of increased fractional anisotropy in synaesthetes vs. controls. To assess the possible involvement of these areas in the synaesthetic experience, we used nine areas of increased gray matter volume as regions of interest in an fMRI experiment that characterized the contrast in response to stimuli which induced synaesthesia (i.e., letters) vs. those which did not (non-meaningful symbols). Four of these areas showed sensitivity to this contrast in synaesthetes but not controls. Unexpectedly, in two of them, in left lateral occipital cortex and in postcentral gyrus, the letter stimuli produced a strong negative BOLD signal in synaesthetes. An additional whole-brain fMRI analysis identified 14 areas, three of which were driven mainly by a negative BOLD response to letters in synaesthetes. Our findings suggest that cortical deactivations may be involved in the conscious experience of internally generated synaesthetic percepts. PMID:24198794

  6. β-Arrestin biosensors reveal a rapid, receptor-dependent activation/deactivation cycle.

    Science.gov (United States)

    Nuber, Susanne; Zabel, Ulrike; Lorenz, Kristina; Nuber, Andreas; Milligan, Graeme; Tobin, Andrew B; Lohse, Martin J; Hoffmann, Carsten

    2016-03-31

    (β-)Arrestins are important regulators of G-protein-coupled receptors (GPCRs). They bind to active, phosphorylated GPCRs and thereby shut off 'classical' signalling to G proteins, trigger internalization of GPCRs via interaction with the clathrin machinery and mediate signalling via 'non-classical' pathways. In addition to two visual arrestins that bind to rod and cone photoreceptors (termed arrestin1 and arrestin4), there are only two (non-visual) β-arrestin proteins (β-arrestin1 and β-arrestin2, also termed arrestin2 and arrestin3), which regulate hundreds of different (non-visual) GPCRs. Binding of these proteins to GPCRs usually requires the active form of the receptors plus their phosphorylation by G-protein-coupled receptor kinases (GRKs). The binding of receptors or their carboxy terminus as well as certain truncations induce active conformations of (β-)arrestins that have recently been solved by X-ray crystallography. Here we investigate both the interaction of β-arrestin with GPCRs, and the β-arrestin conformational changes in real time and in living human cells, using a series of fluorescence resonance energy transfer (FRET)-based β-arrestin2 biosensors. We observe receptor-specific patterns of conformational changes in β-arrestin2 that occur rapidly after the receptor-β-arrestin2 interaction. After agonist removal, these changes persist for longer than the direct receptor interaction. Our data indicate a rapid, receptor-type-specific, two-step binding and activation process between GPCRs and β-arrestins. They further indicate that β-arrestins remain active after dissociation from receptors, allowing them to remain at the cell surface and presumably signal independently. Thus, GPCRs trigger a rapid, receptor-specific activation/deactivation cycle of β-arrestins, which permits their active signalling. PMID:27007855

  7. Heating, ventilating, and air conditioning deactivation thermal analysis of PUREX Plant

    Energy Technology Data Exchange (ETDEWEB)

    Chen, W.W.; Gregonis, R.A. [Westinghouse Hanford Company, Richland, WA (United States)

    1997-08-01

    Thermal analysis was performed for the proposed Plutonium Uranium Extraction Plant exhaust system after deactivation. The purpose of the analysis was to determine if enough condensation will occur to plug or damage the filtration components. A heat transfer and fluid flow analysis was performed to evaluate the thermal characteristics of the underground duct system, the deep-bed glass fiber filter No. 2, and the high-efficiency particulate air filters in the fourth filter building. The analysis is based on extreme variations of air temperature, relative humidity, and dew point temperature using 15 years of Hanford Site weather data as a basis. The results will be used to evaluate the need for the electric heaters proposed for the canyon exhaust to prevent condensation. Results of the analysis indicate that a condition may exist in the underground ductwork where the duct temperature can lead or lag changes in the ambient air temperature. This condition may contribute to condensation on the inside surfaces of the underground exhaust duct. A worst case conservative analysis was performed assuming that all of the water is removed from the moist air over the inside surface of the concrete duct area in the fully developed turbulent boundary layer while the moist air in the free stream will not condense. The total moisture accumulated in 24 hours is negligible. Water puddling would not be expected. The results of the analyses agree with plant operating experiences. The filters were designed to resist high humidity and direct wetting, filter plugging caused by slight condensation in the upstream duct is not a concern. 19 refs., 2 figs.

  8. Understanding the mechanism of DNA deactivation in ion therapy of cancer cells: hydrogen peroxide action*

    Science.gov (United States)

    Piatnytskyi, Dmytro V.; Zdorevskyi, Oleksiy O.; Perepelytsya, Sergiy M.; Volkov, Sergey N.

    2015-11-01

    Changes in the medium of biological cells under ion beam irradiation has been considered as a possible cause of cell function disruption in the living body. The interaction of hydrogen peroxide, a long-lived molecular product of water radiolysis, with active sites of DNA macromolecule was studied, and the formation of stable DNA-peroxide complexes was considered. The phosphate groups of the macromolecule backbone were picked out among the atomic groups of DNA double helix as a probable target for interaction with hydrogen peroxide molecules. Complexes consisting of combinations including: the DNA phosphate group, H2O2 and H2O molecules, and Na+ counterion, were considered. The counterions have been taken into consideration insofar as under the natural conditions they neutralise DNA sugar-phosphate backbone. The energy of the complexes have been determined by considering the electrostatic and the Van der Waals interactions within the framework of atom-atom potential functions. As a result, the stability of various configurations of molecular complexes was estimated. It was shown that DNA phosphate groups and counterions can form stable complexes with hydrogen peroxide molecules, which are as stable as the complexes with water molecules. It has been demonstrated that the formation of stable complexes of H2O2-Na+-PO4- may be detected experimentally by observing specific vibrations in the low-frequency Raman spectra. The interaction of H2O2 molecule with phosphate group of the double helix backbone can disrupt DNA biological function and induce the deactivation of the cell genetic apparatus. Thus, the production of hydrogen peroxide molecules in the nucleus of living cells can be considered as an additional mechanism by which high-energy ion beams destroy tumour cells during ion beam therapy. Contribution to the Topical Issue "COST Action Nano-IBCT: Nano-scale Processes Behind Ion-Beam Cancer Therapy", edited by Andrey Solov'yov, Nigel Mason, Gustavo García, Eugene

  9. Understanding the mechanism of DNA deactivation in ion therapy of cancer cells: hydrogen peroxide action

    International Nuclear Information System (INIS)

    Changes in the medium of biological cells under ion beam irradiation has been considered as a possible cause of cell function disruption in the living body. The interaction of hydrogen peroxide, a long lived molecular product of water radiolysis, with active sites of DNA macromolecule was studied, and the formation of stable DNA-peroxide complexes was considered. The phosphate groups of the macromolecule backbone were picked out among the atomic groups of DNA double helix as a probable target for interaction with hydrogen peroxide molecules. Complexes consisting of combinations including: the DNA phosphate group, H2O2 and H2O molecules, and Na+ counter-ion, were considered. The counter-ions have been taken into consideration in so far as under the natural conditions they neutralise DNA sugar-phosphate backbone. The energy of the complexes have been determined by considering the electrostatic and the Van der Waals interactions within the framework of atom-atom potential functions. As a result, the stability of various configurations of molecular complexes was estimated. It was shown that DNA phosphate groups and counter-ions can form stable complexes with hydrogen peroxide molecules, which are as stable as the complexes with water molecules. It has been demonstrated that the formation of stable complexes of H2O2- Na+-PO4- may be detected experimentally by observing specific vibrations in the low-frequency Raman spectra. The interaction of H2O2 molecule with phosphate group of the double helix backbone can disrupt DNA biological function and induce the deactivation of the cell genetic apparatus. Thus, the production of hydrogen peroxide molecules in the nucleus of living cells can be considered as an additional mechanism by which high-energy ion beams destroy tumour cells during ion beam therapy. (authors)

  10. Waste Management

    International Nuclear Information System (INIS)

    The objectives of SCK-CEN's programme on radioactive waste management are: (1) to reduce the impact of the waste to the stakeholders, the public and the environment; (2) to develop a management tool allowing to identify waste problems and to optimise decommissioning strategies; (3) to perform decommissioning activities in a safe and economical way; (4) to manage waste in a safe and economical way according to legislation; (5) to develop treatment/conditioning processes to minimise risks, volumes and cost of radioactive waste. Main projects and achievements in 1999 are summarised

  11. Proceedings of the fourth Pacific Basin nuclear conference

    International Nuclear Information System (INIS)

    The 45 papers presented at this conference examined the status, future plans and significance of nuclear development for the Pacific Basin. Sessions covered the topics of energy and economics, nuclear power programs, the fuel cycle, waste management, seismic design, radionuclide production and use, and issues affecting nuclear goals

  12. Agricultural Waste.

    Science.gov (United States)

    Xue, Ling; Zhang, Panpan; Shu, Huajie; Chang, Chein-Chi; Wang, Renqing; Zhang, Shuping

    2016-10-01

    In recent years, the quantity of agricultural waste has been rising rapidly all over the world. As a result, the environmental problems and negative impacts of agricultural waste are drawn more and more attention. Therefore, there is a need to adopt proper approaches to reduce and reuse agricultural waste. This review presented about 200 literatures published in 2015 relating to the topic of agricultural waste. The review examined research on agricultural waste in 2015 from the following four aspects: the characterization, reuse, treatment, and management. Researchers highlighted the importance to reuse agricultural waste and investigated the potential to utilize it as biofertilizers, cultivation material, soil amendments, adsorbent, material, energy recycling, enzyme and catalyst etc. The treatment of agricultural waste included carbonization, biodegradation, composting hydrolysis and pyrolysis. Moreover, this review analyzed the differences of the research progress in 2015 from 2014. It may help to reveal the new findings and new trends in this field in 2015 comparing to 2014. PMID:27620093

  13. Psychosocial versus physiological stress - Meta-analyses on deactivations and activations of the neural correlates of stress reactions.

    Science.gov (United States)

    Kogler, Lydia; Müller, Veronika I; Chang, Amy; Eickhoff, Simon B; Fox, Peter T; Gur, Ruben C; Derntl, Birgit

    2015-10-01

    Stress is present in everyday life in various forms and situations. Two stressors frequently investigated are physiological and psychosocial stress. Besides similar subjective and hormonal responses, it has been suggested that they also share common neural substrates. The current study used activation-likelihood-estimation meta-analysis to test this assumption by integrating results of previous neuroimaging studies on stress processing. Reported results are cluster-level FWE corrected. The inferior frontal gyrus (IFG) and the anterior insula (AI) were the only regions that demonstrated overlapping activation for both stressors. Analysis of physiological stress showed consistent activation of cognitive and affective components of pain processing such as the insula, striatum, or the middle cingulate cortex. Contrarily, analysis across psychosocial stress revealed consistent activation of the right superior temporal gyrus and deactivation of the striatum. Notably, parts of the striatum appeared to be functionally specified: the dorsal striatum was activated in physiological stress, whereas the ventral striatum was deactivated in psychosocial stress. Additional functional connectivity and decoding analyses further characterized this functional heterogeneity and revealed higher associations of the dorsal striatum with motor regions and of the ventral striatum with reward processing. Based on our meta-analytic approach, activation of the IFG and the AI seems to indicate a global neural stress reaction. While physiological stress activates a motoric fight-or-flight reaction, during psychosocial stress attention is shifted towards emotion regulation and goal-directed behavior, and reward processing is reduced. Our results show the significance of differentiating physiological and psychosocial stress in neural engagement. Furthermore, the assessment of deactivations in addition to activations in stress research is highly recommended. PMID:26123376

  14. Psychosocial versus physiological stress - Meta-analyses on deactivations and activations of the neural correlates of stress reactions.

    Science.gov (United States)

    Kogler, Lydia; Müller, Veronika I; Chang, Amy; Eickhoff, Simon B; Fox, Peter T; Gur, Ruben C; Derntl, Birgit

    2015-10-01

    Stress is present in everyday life in various forms and situations. Two stressors frequently investigated are physiological and psychosocial stress. Besides similar subjective and hormonal responses, it has been suggested that they also share common neural substrates. The current study used activation-likelihood-estimation meta-analysis to test this assumption by integrating results of previous neuroimaging studies on stress processing. Reported results are cluster-level FWE corrected. The inferior frontal gyrus (IFG) and the anterior insula (AI) were the only regions that demonstrated overlapping activation for both stressors. Analysis of physiological stress showed consistent activation of cognitive and affective components of pain processing such as the insula, striatum, or the middle cingulate cortex. Contrarily, analysis across psychosocial stress revealed consistent activation of the right superior temporal gyrus and deactivation of the striatum. Notably, parts of the striatum appeared to be functionally specified: the dorsal striatum was activated in physiological stress, whereas the ventral striatum was deactivated in psychosocial stress. Additional functional connectivity and decoding analyses further characterized this functional heterogeneity and revealed higher associations of the dorsal striatum with motor regions and of the ventral striatum with reward processing. Based on our meta-analytic approach, activation of the IFG and the AI seems to indicate a global neural stress reaction. While physiological stress activates a motoric fight-or-flight reaction, during psychosocial stress attention is shifted towards emotion regulation and goal-directed behavior, and reward processing is reduced. Our results show the significance of differentiating physiological and psychosocial stress in neural engagement. Furthermore, the assessment of deactivations in addition to activations in stress research is highly recommended.

  15. The Orosomucoid 1 protein is involved in the vitamin D – mediated macrophage de-activation process

    Energy Technology Data Exchange (ETDEWEB)

    Gemelli, Claudia, E-mail: claudia.gemelli@unimore.it [Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena (Italy); Center for Regenerative Medicine, University of Modena and Reggio Emilia, Via Gottardi 100, 41125 Modena (Italy); Martello, Andrea; Montanari, Monica; Zanocco Marani, Tommaso; Salsi, Valentina; Zappavigna, Vincenzo; Parenti, Sandra; Vignudelli, Tatiana; Selmi, Tommaso; Ferrari, Sergio; Grande, Alexis [Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena (Italy)

    2013-12-10

    Orosomucoid 1 (ORM1), also named Alpha 1 acid glycoprotein A (AGP-A), is an abundant plasma protein characterized by anti-inflammatory and immune-modulating properties. The present study was designed to identify a possible correlation between ORM1 and Vitamin D3 (1,25(OH)2D3), a hormone exerting a widespread effect on cell proliferation, differentiation and regulation of the immune system. In particular, the data described here indicated that ORM1 is a 1,25(OH)2D3 primary response gene, characterized by the presence of a VDRE element inside the 1 kb sequence of its proximal promoter region. This finding was demonstrated with gene expression studies, Chromatin Immunoprecipitation and luciferase transactivation experiments and confirmed by VDR full length and dominant negative over-expression. In addition, several experiments carried out in human normal monocytes demonstrated that the 1,25(OH)2D3 – VDR – ORM1 pathway plays a functional role inside the macrophage de-activation process and that ORM1 may be considered as a signaling molecule involved in the maintenance of tissue homeostasis and remodeling. - Highlights: • ORM1 is a Vitamin D primary response gene. • VD and its receptor VDR are involved in the de-activation process mediated by human resident macrophages. • The signaling pathway VD-VDR-ORM1 plays an important role in the control of macrophage de-activation process. • ORM1 may be defined as a signaling molecule implicated in the maintenance of tissue homeostasis and remodeling.

  16. Effect of substitution on the ultrafast deactivation of the excited state of benzo[b]thiophene-arylamines.

    Science.gov (United States)

    Pina, J; Queiroz, M-J R P; Seixas de Melo, J

    2016-08-01

    A complete and systematic study of the spectroscopic and photophysical properties of five novel diarylamines in the benzo[b]thiophene series (oligoanilines) was performed in solution at room (293 K) and low (77 K) temperature. The title compounds resulting from the link between one aniline unit with a benzo[b]thiophene unit (with two different methyl and methoxy substitution) were characterized using steady-state absorption, fluorescence and phosphorescence spectroscopy, as well as femto- to nano-second time resolved spectroscopies. The study involved the determination of the absorption, emission and triplet-triplet absorption together with all relevant quantum yields (fluorescence, phosphorescence, intersystem crossing, internal conversion and singlet oxygen yields), excited state lifetimes and the overall set of deactivation rate constants (kF, kIC and kISC). This study was further complemented with theoretical calculations, namely with the determination of the optimized ground-state molecular geometries for the diarylamines together with the prediction of the lowest vertical one-electron excitation energy and the relevant molecular orbital contours using DFT calculations. The DFT results were found to corroborate the observed charge-transfer character of the singlet excited state. The experimental results showed that the radiationless decay processes (internal conversion and intersystem-crossing) constitute the main excited state deactivation pathways and that substitution with methyl and methoxy groups induces significant changes in the spectroscopic and photophysical behaviour of these compounds. This was also corroborated by the femtosecond transient absorption study, where it was found that the ultrafast dynamics of the diarylamines was best described by a sequential model featuring fast solvent relaxation followed by conformational relaxation to a more planar excited state, from where singlet excited state deactivation occurs through internal conversion and

  17. Catalyst Deactivation Simulation Through Carbon Deposition in Carbon Dioxide Reforming over Ni/CaO-Al2O3 Catalyst

    Directory of Open Access Journals (Sweden)

    Istadi Istadi

    2011-11-01

    Full Text Available Major problem in CO2 reforming of methane (CORM process is coke formation which is a carbonaceous residue that can physically cover active sites of a catalyst surface and leads to catalyst deactivation. A key to develop a more coke-resistant catalyst lies in a better understanding of the methane reforming mechanism at a molecular level. Therefore, this paper is aimed to simulate a micro-kinetic approach in order to calculate coking rate in CORM reaction. Rates of encapsulating and filamentous carbon formation are also included. The simulation results show that the studied catalyst has a high activity, and the rate of carbon formation is relatively low. This micro-kinetic modeling approach can be used as a tool to better understand the catalyst deactivation phenomena in reaction via carbon deposition. Copyright © 2011 BCREC UNDIP. All rights reserved.(Received: 10th May 2011; Revised: 16th August 2011; Accepted: 27th August 2011[How to Cite: I. Istadi, D.D. Anggoro, N.A.S. Amin, and D.H.W. Ling. (2011. Catalyst Deactivation Simulation Through Carbon Deposition in Carbon Dioxide Reforming over Ni/CaO-Al2O3 Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis, 6 (2: 129-136. doi:10.9767/bcrec.6.2.1213.129-136][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.6.2.1213.129-136 || or local:  http://ejournal.undip.ac.id/index.php/bcrec/article/view/1213 ] | View in  |  

  18. The Orosomucoid 1 protein is involved in the vitamin D – mediated macrophage de-activation process

    International Nuclear Information System (INIS)

    Orosomucoid 1 (ORM1), also named Alpha 1 acid glycoprotein A (AGP-A), is an abundant plasma protein characterized by anti-inflammatory and immune-modulating properties. The present study was designed to identify a possible correlation between ORM1 and Vitamin D3 (1,25(OH)2D3), a hormone exerting a widespread effect on cell proliferation, differentiation and regulation of the immune system. In particular, the data described here indicated that ORM1 is a 1,25(OH)2D3 primary response gene, characterized by the presence of a VDRE element inside the 1 kb sequence of its proximal promoter region. This finding was demonstrated with gene expression studies, Chromatin Immunoprecipitation and luciferase transactivation experiments and confirmed by VDR full length and dominant negative over-expression. In addition, several experiments carried out in human normal monocytes demonstrated that the 1,25(OH)2D3 – VDR – ORM1 pathway plays a functional role inside the macrophage de-activation process and that ORM1 may be considered as a signaling molecule involved in the maintenance of tissue homeostasis and remodeling. - Highlights: • ORM1 is a Vitamin D primary response gene. • VD and its receptor VDR are involved in the de-activation process mediated by human resident macrophages. • The signaling pathway VD-VDR-ORM1 plays an important role in the control of macrophage de-activation process. • ORM1 may be defined as a signaling molecule implicated in the maintenance of tissue homeostasis and remodeling

  19. Impaired microbial activity caused by metal pollution: A field study in a deactivated uranium mining area

    International Nuclear Information System (INIS)

    European frameworks for the ecological risk assessment (ERA) of contaminated sites integrate information from three lines of evidence: chemical, ecotoxicological, and ecological. Regarding the last one, field observations at the contaminated sites are compared to reference site(s) and the differences recorded are analysed at the light of a cause-effect relationship, taking into account the site-specific contamination. Thus, included in the tier 2 of a site-specific risk assessment that is being carried out in an deactivated uranium mining area, a battery of soil enzyme activities (dehydrogenases, urease, arysulphatase, cellulase, acid phosphate) and potential nitrification were assessed in seven sampling sites (A–D–E–F–G–H–I) at different distances from the mine pit. These parameters have been considered good indicators of impacts on soil microbial communities and, subsequently, on soil functions. Soil enzyme activities were impaired in the most contaminated site (A, near the mine pit), for which a higher degree of risk was determined in the tier 1 of ERA. Three other sites within the mining area (F, G, and D) were discriminated on the basis of their low microbial activity, using uni- and multivariate approaches, and validating what had been previously found with chemical and ecotoxicological lines of evidence. We observed considerable among-site heterogeneity in terms of soil physical and chemical properties, combined with seasonal differences in enzyme activities. Still, the correlation between microbial parameters and soil general physical and chemical parameters was weak. In opposition, significant and negative correlations were found between soil enzyme activities and several metallic elements (Al, Be, Cu, U). These findings suggest a clear correlation between compromised soil function (nutrient recycling) and metal contamination. Such information reinforces the evidence of risks for some sites within the mining area and is an important

  20. Basin Hopping Graph

    DEFF Research Database (Denmark)

    Kucharik, Marcel; Hofacker, Ivo; Stadler, Peter;

    2014-01-01

    of the folding free energy landscape, however, can provide the relevant information. Results We introduce the basin hopping graph (BHG) as a novel coarse-grained model of folding landscapes. Each vertex of the BHG is a local minimum, which represents the corresponding basin in the landscape. Its edges connect...

  1. Deactivation of selected noble metal catalysts during CO oxidation: An in-situ IR and kinetic study

    International Nuclear Information System (INIS)

    The deactivation of the oxidation of CO over supported Rh, Ru and Pd as a function of the reactant gas composition is discussed. On supported Rh we have found that the rate of CO oxidation is strongly dependent on the oxidation state of the metal. The rate of CO oxidation over supported Ru is strongly inhibited by the incorporation of sub-surface O2. The oxidation of CO on supported Pd is inhibited by the formation of PdO under conditions in which the CO/O2 reactant gas ratio is net oxidizing and by enhanced CO surface coverage following ignition when the reactant gas ratio is net reducing

  2. Isotherm of deactivation in the cocrystallization of a radioelement with low-soluble precipitates formed during coagulation process

    International Nuclear Information System (INIS)

    The isotherm of deactivation was derived for cocrystallization, both according to the Khlopin law and according to the Doerner-Hoskins equation. It was shown that cocrystallization according to the Khlopin law is mathematically indistinguishable from adsorption according to the Henry law, where k=D/Bsub(res). A method is proposed for the separation of these two processes from cocrystallization according to the Doerner-Hoskins law in a study of the dependence of coprecipitation on the amount of the carrier. The applicability of the equations obtained to the treatment of the experimental data is shown for examples taken from the literature

  3. 197Au Moessbauer study of the deactivation and reactivation of a carbon-supported AuCl4- hydrochlorination catalyst

    International Nuclear Information System (INIS)

    Acetylene hydrochlorination catalysts consisting of activated carbon impregnated with a solution of HAuCl4.xH2O in aqua regia have been studied by 197Au Moessbauer spectroscopy. The relative amounts of AuCl4-, of Au(0), and of an Au(I) species formed under certain process conditions were determined quantitatively. Deactivation of the catalyst at low and high temperatures was shown to be due to different mechanisms, and the reactivation of the catalyst by Cl2 gas was studied. (orig.)

  4. K Basin safety analysis

    International Nuclear Information System (INIS)

    The purpose of this accident safety analysis is to document in detail, analyses whose results were reported in summary form in the K Basins Safety Analysis Report WHC-SD-SNF-SAR-001. The safety analysis addressed the potential for release of radioactive and non-radioactive hazardous material located in the K Basins and their supporting facilities. The safety analysis covers the hazards associated with normal K Basin fuel storage and handling operations, fuel encapsulation, sludge encapsulation, and canister clean-up and disposal. After a review of the Criticality Safety Evaluation of the K Basin activities, the following postulated events were evaluated: Crane failure and casks dropped into loadout pit; Design basis earthquake; Hypothetical loss of basin water accident analysis; Combustion of uranium fuel following dryout; Crane failure and cask dropped onto floor of transfer area; Spent ion exchange shipment for burial; Hydrogen deflagration in ion exchange modules and filters; Release of Chlorine; Power availability and reliability; and Ashfall

  5. K Basin safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    Porten, D.R.; Crowe, R.D.

    1994-12-16

    The purpose of this accident safety analysis is to document in detail, analyses whose results were reported in summary form in the K Basins Safety Analysis Report WHC-SD-SNF-SAR-001. The safety analysis addressed the potential for release of radioactive and non-radioactive hazardous material located in the K Basins and their supporting facilities. The safety analysis covers the hazards associated with normal K Basin fuel storage and handling operations, fuel encapsulation, sludge encapsulation, and canister clean-up and disposal. After a review of the Criticality Safety Evaluation of the K Basin activities, the following postulated events were evaluated: Crane failure and casks dropped into loadout pit; Design basis earthquake; Hypothetical loss of basin water accident analysis; Combustion of uranium fuel following dryout; Crane failure and cask dropped onto floor of transfer area; Spent ion exchange shipment for burial; Hydrogen deflagration in ion exchange modules and filters; Release of Chlorine; Power availability and reliability; and Ashfall.

  6. Alboran Basin, southern Spain - Part I: Geomorphology

    Energy Technology Data Exchange (ETDEWEB)

    Munoz, A. [Secretaria General de Pesca Maritima, Corazon de Maria, 8, 28002 Madrid (Spain); Ballesteros, M.; Rivera, J.; Acosta, J. [Instituto Espanol de Oceanografia, Corazon de Maria, 8, 28002 Madrid (Spain); Montoya, I. [Universidad Juan Carlos I, Campus de Mostoles, Madrid (Spain); Uchupi, E. [Woods Hole Oceanographic Institution, Woods Hole, MA 02543 (United States)

    2008-01-15

    Bathymetric, 3D relief and shaded relief maps created from multibeam echo-sounding data image the morphology of the Alboran Basin, a structural low along the east-west-trending Eurasian-African plates boundary. Topographic features in the basin are the consequence of volcanism associated with Miocene rifting, rift and post-rift sedimentation, and recent faulting resulting from the convergence of the African-Eurasian plates. Pleistiocene glacially induced regressions/transgressions when the sea level dropped to about 150 m below its present level gas seeps and bottom currents. Recent faulting and the Pleistocene transgressions/regressions led to mass-wasting, formation of turbidity currents and canyon erosion on the basin's slopes. Recent fault traces at the base of the northern basin slope have also served as passageways for thermogenic methane, the oxidation of which by bacteria led to the formation of carbonate mounds along the fault intercepts on the sea floor. Expulsion of thermogenic or biogenic gas has led to the formation of pockmarks; erosion by bottom currents has resulted in the formation of moats around seamounts and erosion of the seafloor of the Alboran Ridge and kept the southern edge of the 36 10'N high sediment free. (author)

  7. Socioeconomic data base report for the Paradox Basin, Utah

    International Nuclear Information System (INIS)

    This report is published as a product of the Civilian Radioactive Waste Management (CRWM) Program. The objective of this program is to develop terminal waste storage facilities in deep, stable geologic formations for high-level nuclear wastes, including spent fuel elements from commercial power reactors and transuranic nuclear waste for which the Federal Government is responsible. The Socioeconomic Analysis Report for the Paradox Basin in Utah is part of the CRWM Program described above. This report presents baseline data on the demography, economics, community facilities, government and fiscal structure, and social structure characteristics in San Juan and Grand Counties, the socioeconomic study area. The technical criteria upon which a repository site(s) will be selected, evaluated, and licensed for high-level waste disposal will be partially based on the data in this report

  8. Industrial Waste

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund

    2011-01-01

    Industrial waste is waste from industrial production and manufacturing. Industry covers many industrial sectors and within each sector large variations are found in terms of which raw materials are used, which production technology is used and which products are produced. Available data on unit...... generation rates and material composition as well as determining factors are discussed in this chapter. Characterizing industrial waste is faced with the problem that often only a part of the waste is handled in the municipal waste system, where information is easily accessible. In addition part...... of the industrial waste may in periods, depending on market opportunities and prices, be traded as secondary rawmaterials. Production-specificwaste from primary production, for example steel slag, is not included in the current presentation. In some countries industries must be approved or licensed and as part...

  9. Final deactivation project report on the High Radiation Level Analytical Facility, Building 3019B at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    The purpose of this report is to document the condition of the High Radiation Level Analytical Facility (Building 3019B) at Oak Ridge National Laboratory (ORNL) after completion of deactivation activities. This report identifies the activities conducted to place the facility in a safe and environmentally sound condition prior to transfer to the Environmental Restoration EM-40 Program. This document provides a history and description of the facility prior to the commencement of deactivation activities and documents the condition of the building after completion of all deactivation activities. Turnover items, such as the Post-Deactivation Surveillance and Maintenance (S ampersand M) Plan, remaining hazardous materials inventory, radiological controls, safeguards and security, quality assurance, facility operations, and supporting documentation provided in the Nuclear Material and Facility Stabilization (EM-60) Turnover package are discussed. Building 3019B will require access to perform required S ampersand M activities to maintain the building safety envelope. Building 3019B was stabilized during deactivation so that when transferred to the EM-40 Program, only a minimal S ampersand M effort would be required to maintain the building safety envelope. Other than the minimal S ampersand M activities the building will be unoccupied and the exterior doors locked to prevent unauthorized access. The building will be entered only to perform the required S ampersand M until decommissioning activities begin

  10. Final deactivation project report on the High Radiation Level Analytical Facility, Building 3019B at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    The purpose of this report is to document the condition of the High Radiation Level Analytical Facility (Building 3019B) at Oak Ridge National Laboratory (ORNL) after completion of deactivation activities. This report identifies the activities conducted to place the facility in a safe and environmentally sound condition prior to transfer to the Environmental Restoration EM-40 Program. This document provides a history and description of the facility prior to the commencement of deactivation activities and documents the condition of the building after completion of all deactivation activities. Turnover items, such as the Post-Deactivation Surveillance and Maintenance (S&M) Plan, remaining hazardous materials inventory, radiological controls, safeguards and security, quality assurance, facility operations, and supporting documentation provided in the Nuclear Material and Facility Stabilization (EM-60) Turnover package are discussed. Building 3019B will require access to perform required S&M activities to maintain the building safety envelope. Building 3019B was stabilized during deactivation so that when transferred to the EM-40 Program, only a minimal S&M effort would be required to maintain the building safety envelope. Other than the minimal S&M activities the building will be unoccupied and the exterior doors locked to prevent unauthorized access. The building will be entered only to perform the required S&M until decommissioning activities begin.

  11. Waste indicators

    International Nuclear Information System (INIS)

    The Waste Indicator Project focuses on methods to evaluate the efficiency of waste management. The project proposes the use of three indicators for resource consumption, primary energy and landfill requirements, based on the life-cycle principles applied in the EDIP Project. Trial runs are made With the indicators on paper, glass packaging and aluminium, and two models are identified for mapping the Danish waste management, of which the least extensive focuses on real and potential savings. (au)

  12. Waste indicators

    Energy Technology Data Exchange (ETDEWEB)

    Dall, O.; Lassen, C.; Hansen, E. [Cowi A/S, Lyngby (Denmark)

    2003-07-01

    The Waste Indicator Project focuses on methods to evaluate the efficiency of waste management. The project proposes the use of three indicators for resource consumption, primary energy and landfill requirements, based on the life-cycle principles applied in the EDIP Project. Trial runs are made With the indicators on paper, glass packaging and aluminium, and two models are identified for mapping the Danish waste management, of which the least extensive focuses on real and potential savings. (au)

  13. Waste Management

    OpenAIRE

    Anonymous

    2006-01-01

    The Productivity Commission’s inquiry report into ‘Waste Management’ was tabled by Government in December 2006. The Australian Government asked the Commission to identify policies that would enable Australia to address market failures and externalities associated with the generation and disposal of waste, and recommend how resource efficiencies can be optimised to improve economic, environmental and social outcomes. In the final report, the Commission maintains that waste management policy sh...

  14. Radioactive Wastes.

    Science.gov (United States)

    Choudri, B S; Baawain, Mahad

    2016-10-01

    Papers reviewed herein present a general overview of radioactive waste activities around the world in 2015. These include safety assessments, decommission and decontamination of nuclear facilities, fusion facilities, transportation and management solutions for the final disposal of low and high level radioactive wastes (LLW and HLW), interim storage and final disposal options for spent fuel (SF), and tritiated wastes, with a focus on environmental impacts due to the mobility of radionuclides in water, soil and ecosystem alongwith other progress made in the management of radioactive wastes. PMID:27620100

  15. Radioactive Wastes.

    Science.gov (United States)

    Choudri, B S; Baawain, Mahad

    2015-10-01

    Papers reviewed herein present a general overview of radioactive waste activities around the world in 2014. These include safety assessments, decommission and decontamination of nuclear facilities, fusion facilities, transportation and management solutions for the final disposal of low and high level radioactive wastes (LLW and HLW), interim storage and final disposal options for spent fuel (SF), and tritiated wastes, with a focus on environmental impacts due to the mobility of radionuclides in water, soil and ecosystem alongwith other progress made in the management of radioactive wastes. PMID:26420096

  16. Radioactive Wastes.

    Science.gov (United States)

    Choudri, B S; Baawain, Mahad

    2016-10-01

    Papers reviewed herein present a general overview of radioactive waste activities around the world in 2015. These include safety assessments, decommission and decontamination of nuclear facilities, fusion facilities, transportation and management solutions for the final disposal of low and high level radioactive wastes (LLW and HLW), interim storage and final disposal options for spent fuel (SF), and tritiated wastes, with a focus on environmental impacts due to the mobility of radionuclides in water, soil and ecosystem alongwith other progress made in the management of radioactive wastes.

  17. Wada basin boundaries and basin cells

    NARCIS (Netherlands)

    Nusse, H.E.; Yorke, J.A.

    1996-01-01

    In dynamical systems examples are common in which two or more attractors coexist, and in such cases the basin boundary is nonempty. We consider a two-dimensional diffeomorphism F (that is, F is an invertible map and both F and its inverse are differentiable with continuous derivatives), which has at

  18. Idaho National Engineering and Environmental Laboratory, Old Waste Calcining Facility, Scoville vicinity, Butte County, Idaho -- Photographs, written historical and descriptive data. Historical American engineering record

    International Nuclear Information System (INIS)

    This report describes the history of the Old Waste Calcining Facility. It begins with introductory material on the Idaho National Engineering and Environmental Laboratory, the Materials Testing Reactor fuel cycle, and the Idaho Chemical Processing Plant. The report then describes management of the wastes from the processing plant in the following chapters: Converting liquid to solid wastes; Fluidized bed waste calcining process and the Waste Calcining Facility; Waste calcining campaigns; WCF gets a new source of heat; New Waste Calcining Facility; Last campaign; Deactivation and the RCRA cap; Significance/context of the old WCF. Appendices contain a photo key map for HAER photos, a vicinity map and neighborhood of the WCF, detailed description of the calcining process, and chronology of WCF campaigns

  19. Dynamic environmental transmission electron microscopy observation of platinum electrode catalyst deactivation in a proton-exchange-membrane fuel cell

    International Nuclear Information System (INIS)

    Spherical-aberration-corrected environmental transmission electron microscopy (AC-ETEM) was applied to study the catalytic activity of platinum/amorphous carbon electrode catalysts in proton-exchange-membrane fuel cells (PEMFCs). These electrode catalysts were characterized in different atmospheres, such as hydrogen and air, and a conventional high vacuum of 10−5 Pa. A high-speed charge coupled device camera was used to capture real-time movies to dynamically study the diffusion and reconstruction of nanoparticles with an information transfer down to 0.1 nm, a time resolution below 0.2 s and an acceleration voltage of 300 kV. With such high spatial and time resolution, AC-ETEM permits the visualization of surface-atom behaviour that dominates the coalescence and surface-reconstruction processes of the nanoparticles. To contribute to the development of robust PEMFC platinum/amorphous carbon electrode catalysts, the change in the specific surface area of platinum particles was evaluated in hydrogen and air atmospheres. The deactivation of such catalysts during cycle operation is a serious problem that must be resolved for the practical use of PEMFCs in real vehicles. In this paper, the mechanism for the deactivation of platinum/amorphous carbon electrode catalysts is discussed using the decay rate of the specific surface area of platinum particles, measured first in a vacuum and then in hydrogen and air atmospheres for comparison. (paper)

  20. Adsorption and Deactivation Characteristics of Cu/ZnO-Based Catalysts for Methanol Synthesis from Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Natesakhawat, Sittichai; Ohodnicki, Paul R; Howard, Bret H; Lekse, Jonathan W; Baltrus, John P; Matranga, Christopher

    2013-07-09

    The adsorption and deactivation characteristics of coprecipitated Cu/ZnO-based catalysts were examined and correlated to their performance in methanol synthesis from CO₂ hydrogenation. The addition of Ga₂O₃ and Y₂O₃ promoters is shown to increase the Cu surface area and CO₂/H₂ adsorption capacities of the catalysts and enhance methanol synthesis activity. Infrared studies showed that CO₂ adsorbs spontaneously on these catalysts at room temperature as both monoand bi-dentate carbonate species. These weakly bound species desorb completely from the catalyst surface by 200 °C while other carbonate species persist up to 500 °C. Characterization using N₂O decomposition, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) with energy-dispersive X-ray spectroscopy (EDX) analysis clearly indicated that Cu sintering is the main cause of catalyst deactivation. Ga and Y promotion improves the catalyst stability by suppressing the agglomeration of Cu and ZnO particles under pretreatment and reaction conditions.

  1. Work plan for the High Ranking Facilities Deactivation Project at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    The High Ranking Facilities Deactivation Project (HRFDP), commissioned by the US Department of Energy Nuclear Materials and Facility Stabilization Program, is to place four primary high-risk surplus facilities with 28 associated ancillary facilities at Oak Ridge National Laboratory in a safe, stable, and environmentally sound condition as rapidly and economically as possible. The facilities will be deactivated and left in a condition suitable for an extended period of minimized surveillance and maintenance (S and M) prior to decontaminating and decommissioning (D and D). These four facilities include two reactor facilities containing spent fuel. One of these reactor facilities also contains 55 tons of sodium with approximately 34 tons containing activated sodium-22, 2.5 tons of lithium hydride, approximately 100 tons of potentially contaminated lead, and several other hazardous materials as well as bulk quantities of contaminated scrap metals. The other two facilities to be transferred include a facility with a bank of hot cells containing high levels of transferable contamination and also a facility containing significant quantities of uranyl nitrate and quantities of transferable contamination. This work plan documents the objectives, technical requirements, and detailed work plans--including preliminary schedules, milestones, and conceptual FY 1996 cost estimates--for the Oak Ridge National Laboratory (ORNL). This plan has been developed by the Environmental Restoration (ER) Program of Lockheed Martin Energy Systems (Energy Systems) for the US Department of Energy (DOE) Oak Ridge Operations Office (ORO)

  2. Modifying mesoporous silica nanoparticles to avoid the metabolic deactivation of 6-mercaptopurine and methotrexate in combinatorial chemotherapy

    Science.gov (United States)

    Wang, Wenjing; Fang, Chenjie; Wang, Xiaozhu; Chen, Yuxi; Wang, Yaonan; Feng, Wei; Yan, Chunhua; Zhao, Ming; Peng, Shiqi

    2013-06-01

    Mesoporous silica nanoparticles with amino and thiol groups (MSNSN) were prepared and covalently modified with methotrexate and 6-mercaptopurine to form 6-MP-MSNSN-MTX. In the presence of DTT, 6-MP-MSNSN-MTX gradually releases 6-MP. In rat plasma, 6-MP-MSNSN-MTX effectively inhibits the metabolic deactivation of 6-MP and MTX. 6-MP-MSNSN-MTX could be an agent for long-acting chemotherapy.Mesoporous silica nanoparticles with amino and thiol groups (MSNSN) were prepared and covalently modified with methotrexate and 6-mercaptopurine to form 6-MP-MSNSN-MTX. In the presence of DTT, 6-MP-MSNSN-MTX gradually releases 6-MP. In rat plasma, 6-MP-MSNSN-MTX effectively inhibits the metabolic deactivation of 6-MP and MTX. 6-MP-MSNSN-MTX could be an agent for long-acting chemotherapy. Electronic supplementary information (ESI) available: Experimental details of the synthesis and in vitro and in vivo assays. See DOI: 10.1039/c3nr00227f

  3. Implementation of a Peltier-based cooling device for localized deep cortical deactivation during in vivo object recognition testing

    Science.gov (United States)

    Marra, Kyle; Graham, Brett; Carouso, Samantha; Cox, David

    2012-02-01

    While the application of local cortical cooling has recently become a focus of neurological research, extended localized deactivation deep within brain structures is still unexplored. Using a wirelessly controlled thermoelectric (Peltier) device and water-based heat sink, we have achieved inactivating temperatures (8 mm) than previously reported. After implanting the device into Long Evans rats' basolateral amygdala (BLA), an inhibitory brain center that controls anxiety and fear, we ran an open field test during which anxiety-driven behavioral tendencies were observed to decrease during cooling, thus confirming the device's effect on behavior. Our device will next be implanted in the rats' temporal association cortex (TeA) and recordings from our signal-tracing multichannel microelectrodes will measure and compare activated and deactivated neuronal activity so as to isolate and study the TeA signals responsible for object recognition. Having already achieved a top performing computational face-recognition system, the lab will utilize this TeA activity data to generalize its computational efforts of face recognition to achieve general object recognition.

  4. Regulation of transcription through light-activation and light-deactivation of triplex-forming oligonucleotides in mammalian cells.

    Science.gov (United States)

    Govan, Jeane M; Uprety, Rajendra; Hemphill, James; Lively, Mark O; Deiters, Alexander

    2012-07-20

    Triplex-forming oligonucleotides (TFOs) are efficient tools to regulate gene expression through the inhibition of transcription. Here, nucleobase-caging technology was applied to the temporal regulation of transcription through light-activated TFOs. Through site-specific incorporation of caged thymidine nucleotides, the TFO:DNA triplex formation is blocked, rendering the TFO inactive. However, after a brief UV irradiation, the caging groups are removed, activating the TFO and leading to the inhibition of transcription. Furthermore, the synthesis and site-specific incorporation of caged deoxycytidine nucleotides within TFO inhibitor sequences was developed, allowing for the light-deactivation of TFO function and thus photochemical activation of gene expression. After UV-induced removal of the caging groups, the TFO forms a DNA dumbbell structure, rendering it inactive, releasing it from the DNA, and activating transcription. These are the first examples of light-regulated TFOs and their application in the photochemical activation and deactivation of gene expression. In addition, hairpin loop structures were found to significantly increase the efficacy of phosphodiester DNA-based TFOs in tissue culture. PMID:22540192

  5. Studies on accelerated deactivation of ruthenium-promoted alumina-supported alkalized cobalt Fischer-Tropsch synthesis catalyst

    Institute of Scientific and Technical Information of China (English)

    Shohreh Tehrani; Mohamad Irani; Ahmad Tavasoli; Yadollah Mortazavi; Abbas A.Khodadadi; Ali Nakhaei Pour

    2011-01-01

    Accelerated deactivation of ruthenium-promoted alumina-supported alkalized cobalt(K-Ru-Co/-γ-Al2O3)Fischer-Tropsch(FT)synthesis catalyst along the catalytic bed over 120 h of time-on-stream(TOS)was investigated.Catalytic bed was divided into three parts and structural changes of the spent catalysts collected from each catalytic bed after FT synthesis were studied using different techniques.Rapid deactivation was observed during the reaction due to high reaction temperature and low feed flow rates.The physico-chemical properties of the catalyst charged in the Bed #1 of the reactor did not change significantly.Interaction of cobalt with alumina and the formation of CoAl2O4 increased along the catalytic bed.Reducibility percentage decreased by 4.5%,7.5% and 12.9% for the catalysts in the Beds #1,#2 and #3,respectively.Dispersion decreased by 8.8%,14.4% and 26.6% for the catalysts in the Beds #1,#2 and #3,respectively.Particle diameter increased by 0.6%,2.4% and 10.4% for the catalysts in the Beds #1,#2 and #3,respectively,suggesting higher rate of sintering at the last catalytic bed.The amount of coke at the last catalytic bed was significantly higher than those of Beds #1 and #2.

  6. Work plan for the High Ranking Facilities Deactivation Project at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    The High Ranking Facilities Deactivation Project (HRFDP), commissioned by the US Department of Energy Nuclear Materials and Facility Stabilization Program, is to place four primary high-risk surplus facilities with 28 associated ancillary facilities at Oak Ridge National Laboratory in a safe, stable, and environmentally sound condition as rapidly and economically as possible. The facilities will be deactivated and left in a condition suitable for an extended period of minimized surveillance and maintenance (S and M) prior to decontaminating and decommissioning (D and D). These four facilities include two reactor facilities containing spent fuel. One of these reactor facilities also contains 55 tons of sodium with approximately 34 tons containing activated sodium-22, 2.5 tons of lithium hydride, approximately 100 tons of potentially contaminated lead, and several other hazardous materials as well as bulk quantities of contaminated scrap metals. The other two facilities to be transferred include a facility with a bank of hot cells containing high levels of transferable contamination and also a facility containing significant quantities of uranyl nitrate and quantities of transferable contamination. This work plan documents the objectives, technical requirements, and detailed work plans--including preliminary schedules, milestones, and conceptual FY 1996 cost estimates--for the Oak Ridge National Laboratory (ORNL). This plan has been developed by the Environmental Restoration (ER) Program of Lockheed Martin Energy Systems (Energy Systems) for the US Department of Energy (DOE) Oak Ridge Operations Office (ORO).

  7. Electron beam injected into ground generates subsoil x-rays that may deactivate concealed electronics used to trigger explosive devices

    Science.gov (United States)

    Retsky, Michael

    2008-04-01

    Explosively formed projectiles (EFP) are a major problem in terrorism and asymmetrical warfare. EFPs are often triggered by ordinary infrared motion detectors. A potential weak link is that such electronics are not hardened to ionizing radiation and can latch-up or enter other inoperative states after exposure to a single short event of ionizing radiation. While these can often be repaired with a power restart, they also can produce shorts and permanent damage. A problem of course is that we do not want to add radiation exposure to the long list of war related hazards. Biological systems are highly sensitive to integrated dosage but show no particular sensitivity to short pulses. There may be a way to generate short pulsed subsoil radiation to deactivate concealed electronics without introducing radiation hazards to military personnel and civilian bystanders. Electron beams of 30 MeV that can be produced by portable linear accelerators (linacs) propagate >20 m in air and 10-12 cm in soil. X-radiation is produced by bremsstrahlung and occurs subsoil beneath the point of impact and is mostly forward directed. Linacs 1.5 m long can produce 66 MWatt pulses of subsoil x-radiation 1 microsecond or less in duration. Untested as yet, such a device could be mounted on a robotic vehicle that precedes a military convoy and deactivates any concealed electronics within 10-20 meters on either side of the road.

  8. Experimental investigations and simulation of the deactivation of arsenic during thermal processes after activation by SPER and spike annealing

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Limia, A. [Fraunhofer Institute of Integrated Systems and Device Technology, Schottkystrasse 10, 91058 Erlangen (Germany); Pichler, P. [Fraunhofer Institute of Integrated Systems and Device Technology, Schottkystrasse 10, 91058 Erlangen (Germany); Chair of Electron Devices, University of Erlangen-Nuremberg, Cauerstrasse 6, 91058 Erlangen (Germany)], E-mail: peter.pichler@iisb.fraunhofer.de; Lerch, W.; Paul, S. [Mattson Thermal Products GmbH, Daimlerstrasse 10, 89160 Dornstadt (Germany); Kheyrandish, H. [CSMA - MATS, Queens Road, Stoke on Trent ST4 7LQ (United Kingdom); Pakfar, A.; Tavernier, C. [STMicroelectronics SA, 850 rue Jean Monnet, 38926 Crolles (France)

    2008-12-05

    The possibility of using solid phase epitaxial regrowth (SPER) for activation of arsenic after amorphizing implantation in silicon is explored in this contribution and compared to spike annealing and published flash-annealing experiments. SPER takes advantage of the high activation level of the dopants after SPER combined with practically no dopant diffusion. We performed implantation and annealing experiments for three combinations of implantation energy and dose, and compared the results of SPER and spike annealing. The thermal stability of the dopant distribution was studied by subsequent post-annealing treatment for temperatures between 750 deg. C and 900 deg. C. The results of these experiments were included in the calibration of a diffusion and activation model for arsenic with high predictive capabilities. Additional simulations over a wide range of implantation energies were done to compare the efficiency of SPER, spike and flash annealing. The specific contributions to deactivation via different processes like clustering, precipitation, and segregation are discussed and annealing strategies to minimize the deactivation are proposed. Spike annealing seems to be the best solution for junctions of 25 nm or deeper, while for shallower junctions other processes combining preamorphization, multiple implantation steps, SPER, and/or flash annealing are needed.

  9. 金属减活剂的常见检测方法%Commonly Used Detection Methods of Metal Deactivators

    Institute of Scientific and Technical Information of China (English)

    郭佳

    2012-01-01

    Transformer oil unavoidably contact with copper, iron and other metals in storage, transport and application, therefore these metals promote the oxidation of transformer oil as catalyst, for this reason metal deactivators are widely used in transformer oil to prevent the metal from oxidizing the transformer oil. This paper simply introduced several commonly used methods of metal deactivators.%变压器油在储存、运输和应用过程中不可避免的要与铜、铁等金属接触,这些金属对油品的氧化起到了催化作用。故现在普遍采用向变压器油中加入金属减活剂来抑制金属对油品的催化氧化作用。本文简单介绍了几种金属减活剂的常见检测方法。

  10. Reserves in western basins

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, R.H.; Cotton, B.W. [Scotia Group, Dallas, TX (United States)

    1995-04-01

    The objective of this project is to investigate the reserves potential of tight gas reservoirs in three Rocky Mountain basins: the Greater Green River (GGRB), Uinta and Piceance basins. The basins contain vast gas resources that have been estimated in the thousands of Tcf hosted in low permeability clastic reservoirs. This study documents the productive characteristics of these tight reservoirs, requantifies gas in place resources, and characterizes the reserves potential of each basin. The purpose of this work is to promote understanding of the resource and to encourage its exploitation by private industry. At this point in time, the GGRB work has been completed and a final report published. Work is well underway in the Uinta and Piceance basins which are being handled concurrently, with reports on these basins being scheduled for the middle of this year. Since the GGRB portion of the project has been completed, this presentation win focus upon that basin. A key conclusion of this study was the subdivision of the resource, based upon economic and technological considerations, into groupings that have distinct properties with regard to potential for future producibility, economics and risk profile.

  11. Food waste or wasted food

    OpenAIRE

    van Graas, Maaike Helene

    2014-01-01

    In the industrialized world large amounts of food are daily disposed of. A significant share of this waste could be avoided if different choices were made by individual households. Each day, every household makes decisions to maximize their happiness while balancing restricted amounts of time and money. Thinking of the food waste issue in terms of the consumer choice problem where households can control the amount of wasted food, we can model how households can make the best decisions. I...

  12. Study on Deactivation by Sulfur and Regeneration of Pd/C Catalyst in Hydrogenation of N-(3-nitro-4-methoxyphenyl) Acetamide

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qunfeng; L(U) Jinghui; MA Lei; LU Chunshan; LIU Wei; LI Xiaonian

    2013-01-01

    Deactivation of Pd/C catalyst often occurs in liquid hydrogenation using industrial materials.For instance,the Pd/C catalyst is deactivated severely in the hydrogenation of N-(3-nitro-4-methoxyphenyl) acetamide.In this study,the chemisorption of sulfur on the surface of deactivated Pd/C was detected by energy dispersive spectrometer and X-ray photoelectron spectroscopy.Sulfur compounds poison the Pd/C catalyst and increase the formation of azo deposit,reducing the activity of catalyst.We report a mild method to regenerate the Pd/C catalyst:wash the deposit by N,N-dimethylformamide and oxidize the chemisorbed sulfur by hot air.The regenerated Pd/C catalyst can be reused at least ten runs with stable activity.

  13. Análise do sistema de gerenciamento dos resíduos de serviços de saúde nos municípios da bacia hidrográfica do Rio dos Sinos, Rio Grande do Sul, Brasil Analysis of the management system of the healthcare waste in municipalities of Rio dos Sinos hydrographic basin, Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Luciana Paulo Gomes

    2012-12-01

    Full Text Available Nesta pesquisa focou-se o gerenciamento dos resíduos de serviços de saúde (RSS e especificamente aqueles do tipo perfurocortantes. Foram analisadas as formas atuais de gestão implementadas na bacia hidrográfica do Rio dos Sinos (BHRS, a partir da aplicação de questionários nos estabelecimentos de saúde geradores de RSS. Os resultados indicam que 48,6% dos estabelecimentos de saúde atendem corretamente à legislação específica brasileira, verificando ainda uma melhor gestão para os estabelecimentos privados. Os estabelecimentos de saúde do tipo "laboratórios, bancos de sangue e farmácias" instalados nos municípios com mais de 20.000 habitantes e área municipal na BHRS dentro da faixa de 80 a 100% em relação à área total municipal apresentaram os piores resultados em termos de gestão de RSS. O grupo de atividades de serviços de saúde com o maior número de estabelecimentos na BHRS - "consultórios/clínicas de odontologia, clínicas veterinárias, drogarias e unidade móvel" - indicou um dos menores índices de conhecimento das exigências legais específicas relativas ao tema estudado.This research focused on the management of healthcare waste, specifically about the sharps types. The current ways of management in the Rio dos Sinos basin (BHRS were analyzed with the use of questionnaires in health establishments generators of healthcare waste. The results indicate that 48.6% of health facilities comply with the specific legislation in Brazil, also indicating a better management coming from private institutions. Health facilities of the type "labs, blood banks and pharmacies" installed in municipalities with over 20,000 inhabitants and municipal area in BHRS within the range of 80 to 100% relative to the total municipal area had the worst results in terms of healthcare waste management. The group activities of healthcare services with the highest number of establishments in BHRS - "dental offices/clinics, veterinary

  14. Climatic controls on arid continental basin margin systems

    Science.gov (United States)

    Gough, Amy; Clarke, Stuart; Richards, Philip; Milodowski, Antoni

    2016-04-01

    Alluvial fans are both dominant and long-lived within continental basin margin systems. As a result, they commonly interact with a variety of depositional systems that exist at different times in the distal extent of the basin as the basin evolves. The deposits of the distal basin often cycle between those with the potential to act as good aquifers and those with the potential to act as good aquitards. The interactions between the distal deposits and the basin margin fans can have a significant impact upon basin-scale fluid flow. The fans themselves are commonly considered as relatively homogeneous, but their sedimentology is controlled by a variety of factors, including: 1) differing depositional mechanisms; 2) localised autocyclic controls; 3) geometrical and temporal interactions with deposits of the basin centre; and, 4) long-term allocyclic climatic variations. This work examines the basin margin systems of the Cutler Group sediments of the Paradox Basin, western U.S.A and presents generalised facies models for the Cutler Group alluvial fans as well as for the zone of interaction between these fans and the contemporaneous environments in the basin centre, at a variety of scales. Small-scale controls on deposition include climate, tectonics, base level and sediment supply. It has been ascertained that long-term climatic alterations were the main control on these depositional systems. Models have been constructed to highlight how both long-term and short-term alterations in the climatic regime can affect the sedimentation in the basin. These models can be applied to better understand similar, but poorly exposed, alluvial fan deposits. The alluvial fans of the Brockram Facies, northern England form part of a once-proposed site for low-level nuclear waste decommissioning. As such, it is important to understand the sedimentology, three-dimensional geometry, and the proposed connectivity of the deposits from the perspective of basin-scale fluid flow. The developed

  15. Refinishing contamination floors in Spent Nuclear Fuels storage basins

    International Nuclear Information System (INIS)

    The floors of the K Basins at the Hanford Site are refinished to make decontamination easier if spills occur as the spent nuclear fuel (SNF) is being unloaded from the basins for shipment to dry storage. Without removing the contaminated existing coating, the basin floors are to be coated with an epoxy coating material selected on the basis of the results of field tests of several paint products. The floor refinishing activities must be reviewed by a management review board to ensure that work can be performed in a controlled manner. Major documents prepared for management board review include a report on maintaining radiation exposure as low as reasonably achievable, a waste management plan, and reports on hazard classification and unreviewed safety questions. To protect personnel working in the radiation zone, Operational Health Physics prescribed the required minimum protective methods and devices in the radiological work permit. Also, industrial hygiene safety must be analyzed to establish respirator requirements for persons working in the basins. The procedure and requirements for the refinishing work are detailed in a work package approved by all safety engineers. After the refinishing work is completed, waste materials generated from the refinishing work must be disposed of according to the waste management plan

  16. Treatment Study Plan for Nitrate Salt Waste Remediation Revision 1.0

    Energy Technology Data Exchange (ETDEWEB)

    Juarez, Catherine L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Funk, David John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vigil-Holterman, Luciana R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Naranjo, Felicia Danielle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-07

    The two stabilization treatment methods that are to be examined for their effectiveness in the treatment of both the unremediated and remediated nitrate salt wastes include (1) the addition of zeolite and (2) cementation. Zeolite addition is proposed based on the results of several studies and analyses that specifically examined the effectiveness of this process for deactivating nitrate salts. Cementation is also being assessed because of its prevalence as an immobilization method used for similar wastes at numerous facilities around the DOE complex, including at Los Alamos. The results of this Treatment Study Plan will be used to provide the basis for a Resource Conservation and Recovery Act (RCRA) permit modification request of the LANL Hazardous Waste Facility Permit for approval by the New Mexico Environment Department-Hazardous Waste Bureau (NMED-HWB) of the proposed treatment process and the associated facilities.

  17. Treatment Study Plan for Nitrate Salt Waste Remediation Revision 1.0

    International Nuclear Information System (INIS)

    The two stabilization treatment methods that are to be examined for their effectiveness in the treatment of both the unremediated and remediated nitrate salt wastes include (1) the addition of zeolite and (2) cementation. Zeolite addition is proposed based on the results of several studies and analyses that specifically examined the effectiveness of this process for deactivating nitrate salts. Cementation is also being assessed because of its prevalence as an immobilization method used for similar wastes at numerous facilities around the DOE complex, including at Los Alamos. The results of this Treatment Study Plan will be used to provide the basis for a Resource Conservation and Recovery Act (RCRA) permit modification request of the LANL Hazardous Waste Facility Permit for approval by the New Mexico Environment Department-Hazardous Waste Bureau (NMED-HWB) of the proposed treatment process and the associated facilities.

  18. Catalyst Deactivation and Regeneration in Low Temperature Ethanol Steam Reforming with Rh/CeO2-ZrO2 Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Roh, Hyun-Seog; Platon, Alex; Wang, Yong; King, David L.

    2006-08-01

    Rh/CeO2-ZrO2 catalysts with various CeO2/ZrO2 ratios have been applied to H2 production from ethanol steam reforming at low temperatures. The catalysts all deactivated with time on stream (TOS) at 350 C. The addition of 0.5% K has a beneficial effect on catalyst stability, while 5% K has a negative effect on catalytic activity. The catalyst could be regenerated considerably even at ambient temperature and could recover its initial activity after regeneration above 200 C with 1% O2. The results are most consistent with catalyst deactivation due to carbonaceous deposition on the catalyst.

  19. Tulare Basin protection plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Tulare Basin Protection Plan has been initiated by The Nature Conservancy to elucidate the problems and opportunities of natural diversity protection....

  20. Mitigation : Closed Basin Project

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The upcoming meeting on waterfowl mitigation for the Closed Basin Project will have several people talk about possible changes to the waterfowl mitigation program....

  1. Early Mesozoic basin aquifers

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Early Mesozoic basin aquifers in the states of Massachusettes, Connecticut, New York, New Jersey, Pennsylvania, Maryland,...

  2. California Air Basins

    Data.gov (United States)

    California Department of Resources — Air ResourcesCalifornia Air Resources BoardThe following datasets are from the California Air Resources Board: * arb_california_airbasins - California Air BasinsThe...

  3. K Basin Hazard Analysis

    Energy Technology Data Exchange (ETDEWEB)

    PECH, S.H.

    2000-08-23

    This report describes the methodology used in conducting the K Basins Hazard Analysis, which provides the foundation for the K Basins Final Safety Analysis Report. This hazard analysis was performed in accordance with guidance provided by DOE-STD-3009-94, Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports and implements the requirements of DOE Order 5480.23, Nuclear Safety Analysis Report.

  4. Pipe Crawler internal piping characterization system. Deactivation and decommissioning focus area. Innovative Technology Summary Report

    International Nuclear Information System (INIS)

    Pipe Crawler reg-sign is a pipe surveying system for performing radiological characterization and/or free release surveys of piping systems. The technology employs a family of manually advanced, wheeled platforms, or crawlers, fitted with one or more arrays of thin Geiger Mueller (GM) detectors operated from an external power supply and data processing unit. Survey readings are taken in a step-wise fashion. A video camera and tape recording system are used for video surveys of pipe interiors prior to and during radiological surveys. Pipe Crawler reg-sign has potential advantages over the baseline and other technologies in areas of cost, durability, waste minimization, and intrusiveness. Advantages include potentially reduced cost, potential reuse of the pipe system, reduced waste volume, and the ability to manage pipes in place with minimal disturbance to facility operations. Advantages over competing technologies include potentially reduced costs and the ability to perform beta-gamma surveys that are capable of passing regulatory scrutiny for free release of piping systems

  5. Waste segregation

    International Nuclear Information System (INIS)

    A scoping study has been undertaken to determine the state-of-the-art of waste segregation technology as applied to the management of low-level waste (LLW). Present-day waste segregation practices were surveyed through a review of the recent literature and by means of personal interviews with personnel at selected facilities. Among the nuclear establishments surveyed were Department of Energy (DOE) laboratories and plants, nuclear fuel cycle plants, public and private laboratories, institutions, industrial plants, and DOE and commercially operated shallow land burial sites. These survey data were used to analyze the relationship between waste segregation practices and waste treatment/disposal processes, to assess the developmental needs for improved segregation technology, and to evaluate the costs and benefits associated with the implementation of waste segregation controls. This task was planned for completion in FY 1981. It should be noted that LLW management practices are now undergoing rapid change such that the technology and requirements for waste segregation in the near future may differ significantly from those of the present day. 8 figures

  6. Nuclear waste

    International Nuclear Information System (INIS)

    Radioactive waste is mounting at U.S. nuclear power plants at a rate of more than 2,000 metric tons a year. Pursuant to statute and anticipating that a geologic repository would be available in 1998, the Department of Energy (DOE) entered into disposal contracts with nuclear utilities. Now, however, DOE does not expect the repository to be ready before 2010. For this reason, DOE does not want to develop a facility for monitored retrievable storage (MRS) by 1998. This book is concerned about how best to store the waste until a repository is available, congressional requesters asked GAO to review the alternatives of continued storage at utilities' reactor sites or transferring waste to an MRS facility, GAO assessed the likelihood of an MRSA facility operating by 1998, legal implications if DOE is not able to take delivery of wastes in 1998, propriety of using the Nuclear Waste Fund-from which DOE's waste program costs are paid-to pay utilities for on-site storage capacity added after 1998, ability of utilities to store their waste on-site until a repository is operating, and relative costs and safety of the two storage alternatives

  7. Interlinking feasibility of five river basins of Rajasthan in India

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Vyas

    2016-09-01

    Annual surplus water of about 1437 MCM in the river Chambal is going waste and ultimately reaches to sea after creating flood situations in various places in India including Rajasthan, while on the other hand 1077 MCM water is a requirement in the four other basins in Rajasthan i.e. Banas, Banganga, Gambhir and Parbati at 75% dependability. Interlinking and water transfer from Chambal to these four river basins is the prime solution for which 372 km link channel including 9 km tunnel of design capacity of 300 cumec with 64 m lift is required.

  8. The Aquitaine basin

    Energy Technology Data Exchange (ETDEWEB)

    Biteau, J.-J.; Le Marrec, A.; Le Vot, M.; Masset, J.-M.

    2006-07-01

    The Aquitaine Basin is located in the southwest of France, between the Gironde Arch in the north and the Pyrenean Mountain Chain in the south. It is a triangular-shaped domain, extending over 35000km{sup 2}. From north to south, six main geological provinces can be identified: (1) the Medoc Platform located south of the Gironde Arch; (2) the Parentis sub-basin; (3) the Landes Saddle; (4) the North Aquitaine Platform; (5) the foreland of the Pyrenees (also known as the Adour, Arzacq and Comminges sub-basins); and (6) the Pyrenean fold-and-thrust belt. Only the Parentis sub-basin, the foreland of the Pyrenean Chain and a minor part of the fold-and-thrust belt itself are proven hydrocarbon provinces. The Aquitaine Basin, in turn, is subdivided into four sub-basins - the Parentis, Adour-Arzacq, Tarbes and Comminges areas. The lozenge shape of these depocentres is related to the Hercynian tectonic framework of the Palaeozoic basement, reactivated during Early Cretaceous rifting. This rift phase aborted at the end of the Albian (prior to the development of an oceanic crust) in response to the beginning of the subduction of the Iberian plate under the European plate. During the Upper Cretaceous, continued subduction led to the creation of northwards-migrating flexural basins. In the Eocene, a paroxysmal phase of compression was responsible for the uplift of the Pyrenean Mountain Chain and for the thin-skinned deformation of the foreland basin. The resulting structuration is limited to the south by the internal core of the chain and to the north by the leading edge of the fold-and-thrust belt, where the Lacq and Meillon gas fields are located. Four main petroleum provinces have been exploited since the Second World War: (1) the oil-prone Parentis sub-basin and (2) salt ridges surrounding the Arzacq and Tarbes sub-basins; and (3) the gas-prone southern Arzacq sub-basin (including the external Pyrenean fold-and-thrust belt and the proximal foreland sub-basin) and (4

  9. Nuclear waste

    International Nuclear Information System (INIS)

    This extract from the House of Commons Hansard publication for Wednesday 12th July 1995 considers the current debate on the desirability or otherwise of disposing of low level radioactive waste in landfill sites. It covers wastes generated both by the nuclear industry and by medical processes in local hospitals, and the transport of such waste from source to disposal site. The questions raised lead to a debate about plans to sell off commercially desirable aspects of the nuclear electric generation industry while leaving the costs associated with decommissioning of Magnox reactors as a liability on the public purse. (UK)

  10. Hazard Evaluation for Storage of Spent Nuclear Fuel (SNF) Sludge at the Solid Waste Treatment Facility

    International Nuclear Information System (INIS)

    The Solid Waste Treatment Facility, referred to throughout this document as T Plant, has been identified as the location where sludge from the K Basin fuel storage facilities will be stored until final disposition of the material occurs

  11. Cyclohexene hydrogenation over supported Ru catalysts-study on deactivation-separation of Ru from other metals

    International Nuclear Information System (INIS)

    This work is consecrated to the study of cyclohexene hydrogenation over catalysts on the basis of Ru that belong to the great family of the precious metals based catalysts. These catalysts very sensible to the poisoning by the sulfurated compounds are very active in hydrogenation of unsaturated hydrocarbons. The preparation of their precursors and the realization of the catalysts well identified constituted an important part of this study. The availability of catalytic sites measurement by H sub(2)-O sub(2) titration enables to calculate the number of catalytic sites and opens the possibilities of interesting interpretation of the catalytic properties. In particular it is interesting to compare the observed properties with those described for metallic catalysts on the basis of Pt, Pd, Rh and Ni. The determination of reaction kinetic characteristics and the explanation of the particularities of this system are completed by the study of catalyst deactivation processes during cyclohexene hydrogenation . (Author)

  12. A new integrative model of cerebral activation, deactivation and default mode function in Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Wermke, Marc [Technische Universitaet, Department of Nuclear Medicine, Munich (Germany); Technische Universitaet Muenchen, Nuklearmedizinische Klinik u. Poliklinik, Klinikum rechts der Isar, Muenchen (Germany); Sorg, Christian [Technische Universitaet, Department of Psychiatry and Psychotherapy, Munich (Germany); Wohlschlaeger, Afra M. [Technische Universitaet, Departments of Neuroradiology and Neurology, Munich (Germany); Drzezga, Alexander [Technische Universitaet, Department of Nuclear Medicine, Munich (Germany)

    2008-03-15

    Functional imaging methods such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) allow in vivo assessment of cerebral metabolism at rest and cerebral responses to cognitive stimuli. Activation studies with different cognitive tasks have deepened the understanding of underlying pathology leading to Alzheimer disease (AD) and how the brain reacts to and potentially compensates the imposed damage inflicted by this disease. The aim of this manuscript study was to summarize current findings of activation studies in healthy people at risk for AD, in people with mild cognitive impairment (MCI) as a possible progenitor of AD and finally in patients with manifest AD, adding recent results about impaired deactivation abilities and default mode function in AD. A new comprehensive model will be introduced integrating these heterogeneous findings and explaining their impact on cognitive performance. (orig.)

  13. Does self-ligating brackets type influence the hysteresis, activation and deactivation forces of superelastic NiTi archwires?

    Directory of Open Access Journals (Sweden)

    José Rino Neto

    2013-02-01

    Full Text Available OBJECTIVE: To compare hysteresis, activation and deactivation forces produced by first-order deformation of Contour 0.014-in NiTi wire (Aditek, Brazil in four brands of self-ligating brackets: Damon MX, Easy Clip, Smart Clip and In-Ovation. METHODS: Activation and deactivation forces were measured in an Instron universal tensile machine at 3 mm/minute speed to a total displacement of 4 mm. Tests were repeated eight times for each bracket/wire combination. Statistical analysis comprised ANOVA and Tukey's multiple comparisons test. RESULTS: Using a 4-mm deformation, mean activation forces increased in the following order: Damon = 222 gf, Easy Clip = 228 gf, In-Ovation = 240 gf and Smart Clip = 306 gf. The same order was observed for mean hysteresis values, i.e., 128 gf, 140 gf, 150 gf and 206 gf, respectively. The respective values of deactivation forces for the Damon, Easy Clip, In-Ovation and Smart Clip brackets were 94 gf, 88 gf, 90 gf and 100 gf. CONCLUSIONS: Brackets with higher activation forces were accompanied by higher hysteresis values, which resulted in clinically similar deactivation forces, regardless of the type of self-ligating brackets used.OBJETIVO: comparar as forças de ativação, desativação e histerese produzidas por deformação de primeira ordem do fio superelástico Contour NiTi 0,014" (Aditek® em quatro modelos de braquetes autoligáveis: Damon MX, Easy Clip, Smart Clip e In-Ovation. MÉTODOS: as forças de ativação e desativação foram medidas em máquina universal de tração Instron com velocidade de 3mm/minuto e deslocamento de 4mm. Em cada combinação braquete/fio foram executadas oito repetições. A análise estatística empregou ANOVA e o Teste de Comparações Múltiplas de Tukey. RESULTADOS: com 4mm de deformação, as forças médias de ativação foram, em ordem crescente, Damon = 222gf, Easy Clip = 228gf, In-Ovation = 240gf e Smart-Clip = 306gf; a mesma ordem foi observada nas histereses médias, cujos

  14. Hydrogenation of xylose to xylitol on sponge nickel catalyst: a study of the process and catalyst deactivation kinetics

    Directory of Open Access Journals (Sweden)

    J.-P. Mikkola

    2003-09-01

    Full Text Available The kinetics of hydrogenation of xylose to xylitol on a sponge nickel catalyst (commonly referred to as Raney Ni catalyst and of catalyst deactivation were studied. Plausible explanations for the decrease in catalytic activity by means of surface studies, nitrogen adsorption and thermogravimetric analyses of the fresh and spent catalysts are presented. The kinetic parameters of the process were estimated by the use of a semi-competitive model, which allows full competition between the organic species and the hydrogen atoms for the adsorption sites on the catalyst surface (competitive case. In the model, a competitiveness factor (alpha is introduced to take into account that even after complete coverage of the surface by the organic species, interstitial sites remain for the adsorption of the hydrogen atoms.

  15. Dynamic modeling of a H2O-permselective membrane reactor to enhance methanol synthesis from syngas considering catalyst deactivation

    Institute of Scientific and Technical Information of China (English)

    M.Farsi; A.Jahanmiri

    2012-01-01

    In this paper,the effect of water vapor removal on methanol synthesis capacity from syngas in a fixed-bed membrane reactor is studied considering long-term catalyst deactivation.A dynamic heterogeneous one-dimensional mathematical model that is composed of two sides is developed to predict the performance of this configuration.In this configuration,conventional methanol reactor is supported by an aluminasilica composite membrane layer for water vapor removal from reaction zone.To verify the accuracy of the considered model and assumptions,simulation results of the conventional methanol reactor is compared with the industrial plant data under the same process condition.The membrane reactor improves catalyst life time and enhances CO2 conversion to methanol by overcoming the limitation imposed by thermodynamic equilibrium.This configuration has enhanced the methanol production capacity about 4.06% compared with the industrial methanol reactor during the production time.

  16. BN-350 decommissioning problems of radioactive waste management

    International Nuclear Information System (INIS)

    Pursuant of modern concept on radioactive waste management applied in IAEA Member States all radioactive wastes produced during the BN-350 operation and decommissioning are subject to processing in order to be transformed to a form suitable for long-term storage and final disposal. The first two priority objectives for BN-350 reactor are as follows: cesium cleaning from sodium followed by sodium drain, and processing; processing of liquid and solid radioactive waste accumulated during BN-350 operation. Cesium cleaning from sodium and sodium processing to NaOH will be implemented under USA engineering and financial support. However the outputted product might be only subject to temporary storage under special conditions. Currently the problem is being solved on selection of technology for sodium hydroxide conversion to final product incorporated into cement-like matrix ready for disposal pursuant to existing regulatory requirements. Industrial installation is being designed for liquid radioactive waste processing followed by incorporation to cement matrix subject to further disposal. The next general objective is management of radioactive waste expected from BN-350 decommissioning procedure. Complex of engineering-radiation investigation that is being conducted at BN-350 site will provide estimation of solid and liquid radioactive waste that will be produced during the course of the BN-350 decommission. Radioactive wastes that will be produced may be shared for primary (metal structures of both reactor and reactor plant main and auxiliary systems equipment as well as construction wastes of dismantled biological protection, buildings and structures) and secondary (deactivation solutions, tools, materials, cloth, special accessory, etc.). Processing of produced radioactive wastes (including high activity waste) requires the use of special industrial facilities and construction of special buildings and structures for arrangement of facilities mentioned as well as for

  17. Deactivation of Pd Catalysts by Water during Low Temperature Methane Oxidation Relevant to Natural Gas Vehicle Converters

    Directory of Open Access Journals (Sweden)

    Rahman Gholami

    2015-03-01

    Full Text Available Effects of H2O on the activity and deactivation of Pd catalysts used for the oxidation of unburned CH4 present in the exhaust gas of natural-gas vehicles (NGVs are reviewed. CH4 oxidation in a catalytic converter is limited by low exhaust gas temperatures (500–550 °C and low concentrations of CH4 (400–1500 ppmv that must be reacted in the presence of large quantities of H2O (10–15% and CO2 (15%, under transient exhaust gas flows, temperatures, and compositions. Although Pd catalysts have the highest known activity for CH4 oxidation, water-induced sintering and reaction inhibition by H2O deactivate these catalysts. Recent studies have shown the reversible inhibition by H2O adsorption causes a significant drop in catalyst activity at lower reaction temperatures (below 450 °C, but its effect decreases (water adsorption becomes more reversible with increasing reaction temperature. Thus above 500 °C H2O inhibition is negligible, while Pd sintering and occlusion by support species become more important. H2O inhibition is postulated to occur by either formation of relatively stable Pd(OH2 and/or partial blocking by OH groups of the O exchange between the support and Pd active sites thereby suppressing catalytic activity. Evidence from FTIR and isotopic labeling favors the latter route. Pd catalyst design, including incorporation of a second noble metal (Rh or Pt and supports high O mobility (e.g., CeO2 are known to improve catalyst activity and stability. Kinetic studies of CH4 oxidation at conditions relevant to natural gas vehicles have quantified the thermodynamics and kinetics of competitive H2O adsorption and Pd(OH2 formation, but none have addressed effects of H2O on O mobility.

  18. Deactivation Pattern of a “Model” Ni/MgO Catalyst in the Pre-Reforming of n-Hexane

    Directory of Open Access Journals (Sweden)

    Giuseppe Trunfio

    2014-06-01

    Full Text Available The deactivation pattern of a “model” Ni/MgO catalyst in the pre-reforming of n-hexane with steam (T, 450 °C; P, 5–15 bar is reviewed. The influence of the steam-to-carbon ratio (S/C, 1.5–3.5 on the rate of catalyst fouling by coking is ascertained. Catalyst fouling leads to an exponential decay in activity, denoting 1st-order dependence of the coking process on active sites availability. Hydrogen hinders the coking process, though slight activity decay is due to sintering of the active Ni phase. Deactivation by thiophene causes a sharp, almost linear, drop to nearly zero activity within only 6 h; this deactivation is likely due to dissociative adsorption of thiophene with subsequent strong, irreversible chemical adsorption of S-atoms on active Ni sites, i.e., irreversible poisoning. Modeling of activity decay curves (α, at/a0 by proper kinetic equations allows assessing the effects of temperature, pressure, S/C, H2 and thiophene feed on the deactivation pattern of the model Ni/MgO catalyst by coking, sintering, and poisoning phenomena.

  19. Deactivation of La-Fe-ZSM-5 catalyst for selective catalytic reduction of NO with NH{sup 3}. Field study results

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Gongshin; Yang, Ralph T. [Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Chang, Ramsay; Cardoso, Sylvio [Air Pollution Control, Power Generation, Electric Power Research Institute, Palo Alto, CA 94304-1395 (United States); Smith, Randall A. [Fossil Energy Research Corporation, Laguna Hills, CA 92653 (United States)

    2004-11-08

    Results are summarized for a study on the effects of poisons on the La-Fe-ZSM-5 catalyst activity for the selective catalytic reduction of NO by ammonia. The deactivation of La-Fe-ZSM-5 honeycombs was studied in field tests. A honeycomb catalyst containing 25%La-Fe-ZSM-5 had an overall activity similar to that of a commercial vanadia honeycomb catalyst. Long-term activity test results show that the 25%La-Fe-ZSM-5 catalyst activity decreased to 50% after 300h and 25% after 1769h of on-stream flue gas exposure. The deactivation is correlated to the amounts of poisons deposited on the catalyst. Poisons include alkali and alkaline earth metals, As and Hg. Hg was found to be ion-exchanged from HgCl{sup 2} to form Hg-ZSM-5, and Hg was found to be among the strongest poisons. The poisoning effects of these elements appeared to be additive. Thus, from the chemical analysis of the deactivated catalyst, the deactivation of Fe-ZSM-5 can be predicted.

  20. Deactivating fusarium spores throughout anaerobic fermentation in biogas plants. A prospect; Abtoetung von Fusariensporen waehrend des Gaerprozesses in Biogasanlagen. Ein Ausblick

    Energy Technology Data Exchange (ETDEWEB)

    Frauz, B.; Oechsner, H. [Hohenheim Univ., Stuttgart (Germany). Landesanstalt fuer Landwirtschaftliches Maschinen- und Bauwesens; Weinmann, U. [Hohenheim Univ., Stuttgart (Germany). Inst. fuer Tierernaehrung

    2006-07-01

    Fusarium (the most harmful grain fungus in the field, known as fusarium head blight) and its poisonous product, catabolic mycotoxin DON (Deoxynivalenol) are known for their damaging effects. Due to this, the most feasible, environmentally compatible and economical disposal option are being researched in a cooperative project, where deactivating the fungus and reducing its mycotoxin are in the foreground. (orig.)

  1. Carbon-Oxygen Bond Cleavage by Bis(imino)pyridine Iron Compounds : Catalyst Deactivation Pathways and Observation of Acyl C-O Bond Cleavage in Esters

    NARCIS (Netherlands)

    Trovitch, Ryan J.; Lobkovsky, Emil; Bouwkamp, Marco W.; Chirik, Paul J.

    2008-01-01

    Investigations into the substrate scope of bis(imino)pyridine iron-catalyzed hydrogenation and [2 pi + 2 pi]. diene cyclization reactions identified C-O bond cleavage as a principal deactivation pathway. Addition of diallyl or allyl ethyl ether to the bis(imino)pyridine iron dinitrogen complex, ((iP

  2. Waste economy (waste utilization) in the CR

    OpenAIRE

    Urbanová, Ivana

    2011-01-01

    This Bachelor thesis is prepared as general overview of the Czech Republic waste economy. Waste economy is used as individual industrial segment. Bachelor thesis is focused especially on a total production of waste and communal waste, legislative restrictions connected with waste economy in Czech republic and comparison of Czech waste economy with other European Union countries and with Switzerland as well. The issue of decreasing of waste production and its safe and environmentally acceptabl...

  3. Technical support for GEIS: radioactive waste isolation in geologic formations. Volume 4. Baseline rock properties: salt

    International Nuclear Information System (INIS)

    Salt has long been considered a possible repository medium for nuclear waste disposal. This report is a result of a literature survey to determine rock mass properties of a generic salt. The properties of bedded salt deposits from three different areas are considered, namely, the Salina basin, the Permia basin and the Paradox basin. Dome salts are also considered. Because of the special characteristics of salt, especially, its self-healing properties, the rock-mass properties are similar to the intact properties

  4. Geohydrological studies for nuclear waste isolation at the Hanford Reservation. Volume I. Executive summary

    International Nuclear Information System (INIS)

    A study of the hydrology of the Pasco Basin near Richland, Washington, was initiated during FY 1978 as part of a long-term study on the feasibility of nuclear waste disposal in the Columbia River Basalt underlying the Hanford Reservation. This report summarizes the hydrology field program, Pasco Basin modeling, and groundwater chemistry program. Hanford well logs are also reviewed

  5. Geohydrological studies for nuclear waste isolation at the Hanford Reservation. Volume I. Executive summary

    Energy Technology Data Exchange (ETDEWEB)

    Apps, J.; Doe, T.; Doty, B.

    1979-08-01

    A study of the hydrology of the Pasco Basin near Richland, Washington, was initiated during FY 1978 as part of a long-term study on the feasibility of nuclear waste disposal in the Columbia River Basalt underlying the Hanford Reservation. This report summarizes the hydrology field program, Pasco Basin modeling, and groundwater chemistry program. Hanford well logs are also reviewed. (DLC)

  6. Permian Basin location recommendation report

    International Nuclear Information System (INIS)

    Candidate study areas are screened from the Palo Duro and Dalhart Basin areas using data obtained from studies to date and criteria and specifications that consider: rock geometry; rock characteristics; human intrusion potential; surface characteristics; and environmental and socioeconomic conditions. Two preferred locations are recommended from among these areas for additional characterization to identify potential National Waste Terminal Storage (NWTS) salt repository sites. One location, in northeastern Deaf Smith County and southeastern Oldham County, is underlain by two salt units that meet the adopted screening specifications. The other location, in northcentral Swisher County, is underlain by one salt unit that meets the adopted screening specifications. Both locations have several favorable features, relative to surrounding areas, and no obviously undesirable characteristics. Both lie wholly on the Southern High Plains surface, are in relatively sparsely populated areas, contain no unique land use conflicts, and comprise large enough geographic areas to provide flexibility in site selection. Data gathered to date indicate that these locations contain salt units sufficient in thickness and in depth for the safe construction and operation of the underground facilities under consideration. 93 references, 34 figures, 6 tables

  7. Repository site data and information in bedded salt: Palo Duro Basin, Texas

    International Nuclear Information System (INIS)

    This report is a compilation of data from the literature on the Palo Duro Basin. The Palo Duro Basin is a structural basin, about 150 miles long and 80 miles wide, that is a part of the much larger Permian Basin. The US Department of Energy is investigating the Palo Duro Basin as a potentially suitable area for the site of a repository for the disposal of high-level radioactive waste. Sediments overlying the Precambrian basement range from about 5000 to about 11,000 ft in thickness and from Cambrian to Holocene in age. The strata in the Palo Duro Basin that are of primary interest to the Department of Energy are the bedded salts of the Permian San Andres Formation. The total thickness of the bedded salts is about 2000 ft. The geology of the Palo Duro Basin is well understood. A great deal of information exists on the properties of salt, although much of the available information was not collected in the Palo Duro Basin. Mineral resources are not currently being exploited from the center of the Palo Duro Basin at depth, although the possibility of exploration for and development of such resources can not be ruled out. The continued existence of salts of Permian age indicates a lack of any large amount of circulating ground water. The hydrology of the pre-Tertiary rocks, however, is currently too poorly understood to carry out detailed, site-specific hydrologic modeling with a high degree of confidence. In general, ground water flows from west to east in the Basin. There is little or no hydraulic connection between aquifers above and below the salt sequences. Potable water is pumped from the Ogallala aquifer. Most of the other aquifers yield only nonpotable water. More extensive hydrological data are needed for detailed future modeling in support of risk assessment for a possible repository for high-level waste in the Palo Duro Basin. 464 references

  8. Multi basin desalination using biomass heat source and analytical validation using RSM

    International Nuclear Information System (INIS)

    Highlights: • Biomass boiler is coupled with multi basin solar still. • Top basin is divided into small stepped basins. • Surface response method is used for analytical validation. • Biomass is eco-friendly. • Higher productivity than conventional still. - Abstract: In this field a multi basin solar still is, used to heighten the productivity. The concept of integrating the multi basin still with biomass heat source is introduced in this research area. In the multi basin still heat exchanger is placed at the bottom end of the watershed region. The heat exchanger is connected to the biomass boiler heat source to create heat energy. This system increases the water temperature in the sword and also increases the productivity in the blade. The upper watershed is separated into small stepped basins. So the flat plate collector and stepped basin are used to increase the turnout in this work. The heat from lower basin is used by the upper basin for desalination. Experiments are conducted with various water depths. In this work the solar still behaves like a capacitor. A conventional still is fabricated and run parallel with the experimental setup for comparison. Sensible heat storage materials such as cement blocks, sand, glass eggs are added to the tail end and top basins to increase water temperature. Latent heat storage materials such as water, wax are introduced in the material body of small pellets to increase productivity. Biomass such as wood, wood wastes, palm wastes is tried in this workplace. A higher productivity is obtained for sensible storage materials when compared to latent heat storage. Theoretical analysis is performed by using RSM (response surface methodology) well agrees with experimental values. The efficiency of the system is compared with conventional still. Experiments are conducted in once flow mode, continuous stream mode and solar modes. Output from RSM are compared with experimental values for error analysis

  9. Modifed Great Basin Extent (Buffered)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Two different great basin perimeter files were intersected and dissolved using ArcGIS 10.2.2 to create the outer perimeter of the great basin for use modeling...

  10. Reversing the indus basin closure

    OpenAIRE

    2011-01-01

    After independence, a swift and extensive development of Indus river basin has intensified commitment of water resources. During dry period, the indication of over commitment and basin closure are visible. In the beginning 2000s, he river basin water resources were committed to more than 99% without any environmental flows. The paper tries to unfold drivers closing the Indus basin and the scope for change. Defining and implementing water allocation mechanism to ascertain equity, sustainabilit...

  11. Radionuclides in the Great Lakes basin.

    Science.gov (United States)

    Ahier, B A; Tracy, B L

    1995-12-01

    The Great Lakes basin is of radiologic interest due to the large population within its boundaries that may be exposed to various sources of ionizing radiation. Specific radionuclides of interest in the basin arising from natural and artificial sources include 3H, 14C, 90Sr, 129I, 131I, 137Cs, 222Rn, 226Ra, 235U, 238U, 239Pu, and 241Am. The greatest contribution to total radiation exposure is the natural background radiation that provides an average dose of about 2.6 mSv/year to all basin residents. Global fallout from atmospheric nuclear weapons tests conducted before 1963 has resulted in the largest input of anthropogenic radioactivity into the lakes. Of increasing importance is the radionuclide input from the various components of the nuclear fuel cycle. Although the dose from these activities is currently very low, it is expected to increase if there is continued growth of the nuclear industry. In spite of strict regulations on design and operation of nuclear power facilities, the potential exists for a serious accident as a result of the large inventories of radionuclides contained in the reactor cores; however, these risks are several orders of magnitude less than the risks from other natural and man-made hazards. An area of major priority over the next few decades will be the management of the substantial amounts of radioactive waste generated by nuclear fuel cycle activities. Based on derived risk coefficients, the theoretical incidence of fatal and weighted nonfatal cancers and hereditary defects in the basin's population, attributable to 50 years of exposure to natural background radiation, is conservatively estimated to be of the order of 3.4 x 10(5) cases. The total number of attributable health effects to the year 2050 from fallout radionuclides in the Great Lakes basin is of the order of 5.0 x 10(3). In contrast, estimates of attributable health effects from 50 years of exposure to current nuclear fuel cycle effluent in the basin are of the order of 2

  12. Environmental radiological impact of a Brazilian deactivated Uranium Mine along the period 1999-2009

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, W.S., E-mail: wspereira@inb.gov.br [Industrias Nucleares do Brasil (FCN/GMR/INB), Resende, RJ (Brazil). Fabrica de Combustivel Nuclear. Grupo Multidisciplinar de Radioprotecao; Kelecom, A., E-mail: lararapls@hotmail.com [Universidade Federal Fluminense (LARARA-PLS/UFF), Niteroi, RJ (Brazil). Laboratorio de Radiobiologia e Radiometria Pedro Lopes dos Santos; Silva, A.X., E-mail: ademir@con.ufrj.br [Corrdenacao dos Programas de Pos-Graduacao em Engenharia (COPPE), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear. Departamento de Engenharia Nuclear

    2015-07-01

    This study aims to assess the environmental radiological impact (ERI) from the release of wastewaters used by the Mining Industrial Complex at Poços de Caldas (CIPC), today called Ore Treatment Unit (UTM) in Caldas, MG, Brazil, during the period 1999-2009. The effluent waters were analyzed once a week at point 014 (associated with the mine and waste pile 8). Critical radionuclides are {sup 238}U, {sup 226}Ra, {sup 210}Pb, {sup 232}Th and {sup 228}Ra. The {sup 238}U and {sup 232}Th were analyzed by spectrophotometry. The {sup 226}Ra, {sup 210}Pb and {sup 228}Ra, in turn, were analyzed by radiochemical separation methods and subsequent radiometry. The dose estimates were based on the model proposed by the National Nuclear Energy Commission (CNEN) for a hypothetical critical group associated with the point of effluents release into the river Ribeirao das Antas (point 014). The maximum dose rate allowed by CNEN for release is equal to 0.3 mSv·y{sup -1}for individuals of the critical group. Our calculations were performed using the average concentration along the ten years period study. The estimated dose value for the individual of the critical group was 0.12 mSv·y{sup -1}. It may be concluded that the reference levels established by CNEN were not reached. This indicates that the treatment of effluents generated by the CIPC/UTM was conducted efficiently, ensuring the safety of the population living in the surroundings of the Ore Processing Unit (UTM) at Caldas. (author)

  13. Single-basined choice

    NARCIS (Netherlands)

    Bossert, W.; Peters, H.J.M.

    2013-01-01

    Single-basined preferences generalize single-dipped preferences by allowing for multiple worst elements. These preferences have played an important role in areas such as voting, strategy-proofness and matching problems. We examine the notion of single-basinedness in a choice-theoretic setting. In co

  14. The Mediterranean basin

    DEFF Research Database (Denmark)

    Tomas, Carmen; Sanchez Sanchez, Juan Jose; Barbaro, A.;

    2008-01-01

    genetically from the rest of the populations in the Mediterranean area. This result supports the hypothesis of a low incidence of the south-north genetic interchange at the western shores of the Mediterranean basin. A low genetic distance was found between populations in the Middle East and the western part...

  15. Literature search on the use of resins for treatment of radioactive wastes

    International Nuclear Information System (INIS)

    Over 100 commercial providers with mixed-waste treatability capabilities exist in the US. The maturity level of these technologies varies from a bench scale to a pilot or a commercial scale. The techniques include deactivation, chemical oxidation, recovery of metals, stabilization, vitrification, incineration, biodegradation, and chemical extraction. This report focuses on the use of resins to remove actinides and heavy metals from aqueous waste streams. Only the literature that described resins with high removing efficiency are presented here. The majority of the literature reviewed are proceedings and national or international reports ordered through the Berkeley Lab Library. Some of the reports that the authors requested have not yet arrived. Only a few papers were found in the open literature (journals or magazines). Although this report does not include all existing references, it provides an accurate assessment of efficient resins to be considered for waste minimization procedures. 70 refs

  16. THE DEACTIVATION DECONTAMINATION & DECOMMISSIONING OF THE PLUTONIUM FINISHING PLANT (PFP) A FORMER PLUTONIUM PROCESSING FACILITY AT DOE HANFORD SITE

    Energy Technology Data Exchange (ETDEWEB)

    CHARBONEAU, S.L.

    2006-02-01

    The Plutonium Finishing Plant (PFP) was constructed as part of the Manhattan Project during World War II. The Manhattan Project was developed to usher in the use of nuclear weapons to end the war. The primary mission of the PFP was to provide plutonium used as special nuclear material (SNM) for fabrication of nuclear devices for the war effort. Subsequent to the end of World War II, the PFP's mission expanded to support the Cold War effort through plutonium production during the nuclear arms race and later the processing of fuel grade mixed plutonium-uranium oxide to support DOE's breeder reactor program. In October 1990, at the close of the production mission for PFP, a shutdown order was prepared by the Department of Energy (DOE) in Washington, DC and issued to the Richland DOE field office. Subsequent to the shutdown order, a team from the Defense Nuclear Facilities Safety Board (DNFSB) analyzed the hazards at PFP associated with the continued storage of certain forms of plutonium solutions and solids. The assessment identified many discrete actions that were required to stabilize the different plutonium forms into stable form and repackage the material in high integrity containers. These actions were technically complicated and completed as part of the PFP nuclear material stabilization project between 1995 and early 2005. The completion of the stabilization project was a necessary first step in deactivating PFP. During stabilization, DOE entered into negotiations with the U.S. Environmental Protection Agency (EPA) and the State of Washington and established milestones for the Deactivation and Decommissioning (D&D) of the PFP. The DOE and its contractor, Fluor Hanford (Fluor), have made great progress in deactivating, decontaminating and decommissioning the PFP at the Hanford Site as detailed in this paper. Background information covering the PFP D&D effort includes descriptions of negotiations with the State of Washington concerning consent

  17. THE DEACTIVATION, DECONTAMINATION AND DECOMMISSIONING OF THE PLUTONIUM FINISHING PLANT, A FORMER PLUTONIUM PROCESSING FACILITY AT DOE'S HANFORD SITE

    International Nuclear Information System (INIS)

    The Plutonium Finishing Plant (PFP) was constructed as part of the Manhattan Project during World War II. The Manhattan Project was developed to usher in the use of nuclear weapons to end the war. The primary mission of the PFP was to provide plutonium used as special nuclear material (SNM) for fabrication of nuclear devices for the war effort. Subsequent to the end of World War II, the PFP's mission expanded to support the Cold War effort through plutonium production during the nuclear arms race and later the processing of fuel grade mixed plutonium-uranium oxide to support DOE's breeder reactor program. In October 1990, at the close of the production mission for PFP, a shutdown order was prepared by the Department of Energy (DOE) in Washington,; DC--and issued to the Richland DOE field office. Subsequent to the shutdown order, a team from the Defense Nuclear Facilities Safety Board (DNFSB) analyzed the hazards at PFP associated with the continued storage of certain forms of plutonium solutions and solids. The assessment identified many discrete actions that were required to stabilize the different plutonium forms into stable form and repackage the material in high integrity containers. These actions were technically complicated and completed as part of the PFP nuclear material stabilization project between 1995 and early 2005. The completion of the stabilization project was a necessary first step in deactivating PFP. During stabilization, DOE entered into negotiations with the U.S. Environmental Protection Agency (EPA) and the State of Washington and established milestones for the Deactivation and Decommissioning (DandD) of the PFP. The DOE and its contractor, Fluor Hanford (Fluor), have made great progress in deactivating, decontaminating and decommissioning the PFP at the Hanford Site as detailed in this paper. Background information covering the PFP DandD effort includes descriptions of negotiations with the State of Washington concerning consent

  18. 几种加氢预处理催化剂的失活原因探讨%Investigation on the Causes of Hydrotreating Catalyst Deactivation

    Institute of Scientific and Technical Information of China (English)

    梁相程; 王继锋; 温德荣; 刘雪玲; 喻正南; 赵琰; 连丕勇

    2001-01-01

    The catalyst activity has been estimated through a small hydrogeneration unit. The results indicate that the hydrodenitrogen activity of regenerated catalyst decreased obviously compared with fresh catalyst. The reaction temperature by using regenerated catalyst is 7~8 ℃ higher than by using fresh catalyst . The physicochemical characteristics and their variation before and after regeneration of hydrogeneration catalysts largely used in commercial units were studied through X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR), inductive coupled plasma (ICP), and infrared spectroscopy (IR) in order to obtain the causes of catalyst deactivation. The results show that the deactivation causes of hydrogeneration catalysts used in commercial units fall into three major categories: temporal deactivation caused by pore blocking via coke deposition in the catalyst pores; permanent deactivation caused by pore blocking via heavy metal deposition at the catalyst pore mouths that decreases acidity and deactivates some active sites permanently; permanent deactivation caused by smaller metal aggregation and supports sintering .%通过小型加氢装置对催化剂进行活性评价,结果表明,失活催化剂经再生后加氢脱氮活性明显降低,其反应温度比新鲜催化剂反应温度高7~8 ℃左右。通过使用XRD、XPS、TPR、ICP、IR等技术,测试和表征几种工业大量应用的加氢预处理催化剂,从不同角度研究再生前、后催化剂的各种性能的变化,研究、探讨催化剂失活的原因。研究表明,加氢预处理催化剂经工业使用后,导致催化剂失活的原因有:在运转中碳的沉积使其暂时性失活、重金属沉积堵塞孔口、降低酸度、使催化剂部分活性位永久性失活,而金属聚集、载体烧结使催化剂加氢活性降低,导致催化剂永久性失活。

  19. Bransfield Basin and Cordilleran Orogenesis

    Science.gov (United States)

    Dalziel, I. W.; Austin, J. A.; Barker, D. H.; Christensen, G. L.

    2003-12-01

    Tectonic uplift of the Andean Cordillera was initiated in the mid-Cretaceous with inversion of a composite marginal basin along 7500 km of the continental margin of South America, from Peru to Tierra del Fuego and the North Scotia Ridge. In the southernmost Andes, from 50-56 degrees S, the quasi-oceanic floor of this basin is preserved in the obducted ophiolitic rocks of the Rocas Verdes (Green Rocks) basin. We suggest that the basin beneath Bransfield Strait, 61-64 degrees S, separating the South Shetland Islands from the Antarctic Peninsula, constitutes a modern analog for the Rocas Verdes basin. Marine geophysical studies of Bransfield basin have been undertaken over the past 12 years by the Institute for Geophysics, University of Texas at Austin, under the auspices of the Ocean Sciences Division and United States Antarctic Program, National Science Foundation. These studies have elucidated the structure and evolution of Bransfield basin for comparison with the Rocas Verdes basin, with a view to eventual forward modeling of the evolution of a hypothetical cordilleran orogen by compression and inversion of the basin. These are the processes that can be observed in the tectonic transformation of the Rocas Verdes basin into the southernmost Andean cordillera, as South America moved rapidly westward in an Atlantic-Indian ocean hot-spot reference frame during the mid-Cretaceous. Multi-channel reflection seismic data from the Bransfield basin reveal an asymmetric structural architecture characterized by steeply-dipping normal faults flanking the South Shetlands island arc and gently dipping listric normal faults along the Antarctic Peninsula margin. Normal fault polarity reversals appear to be related to distributed loci of magmatic activity within the basin. This architecture is remarkably similar to that deduced from field structural studies of the Rocas Verdes basin. Notably, the oceanward-dipping, low angle normal faults along the Antarctic Peninsula margin

  20. Long-term accumulation and transport of anthropogenic phosphorus in three river basins

    Science.gov (United States)

    Powers, Stephen M.; Bruulsema, Thomas W.; Burt, Tim P.; Chan, Neng Iong; Elser, James J.; Haygarth, Philip M.; Howden, Nicholas J. K.; Jarvie, Helen P.; Lyu, Yang; Peterson, Heidi M.; Sharpley, Andrew N.; Shen, Jianbo; Worrall, Fred; Zhang, Fusuo

    2016-05-01

    Global food production depends on phosphorus. Phosphorus is broadly applied as fertilizer, but excess phosphorus contributes to eutrophication of surface water bodies and coastal ecosystems. Here we present an analysis of phosphorus fluxes in three large river basins, including published data on fertilizer, harvested crops, sewage, food waste and river fluxes. Our analyses reveal that the magnitude of phosphorus accumulation has varied greatly over the past 30-70 years in mixed agricultural-urban landscapes of the Thames Basin, UK, the Yangtze Basin, China, and the rural Maumee Basin, USA. Fluxes of phosphorus in fertilizer, harvested crops, food waste and sewage dominate over the river fluxes. Since the late 1990s, net exports from the Thames and Maumee Basins have exceeded inputs, suggesting net mobilization of the phosphorus pool accumulated in earlier decades. In contrast, the Yangtze Basin has consistently accumulated phosphorus since 1980. Infrastructure modifications such as sewage treatment and dams may explain more recent declines in total phosphorus fluxes from the Thames and Yangtze Rivers. We conclude that human-dominated river basins may undergo a prolonged but finite accumulation phase when phosphorus inputs exceed agricultural demand, and this accumulated phosphorus may continue to mobilize long after inputs decline.

  1. Tracing Waste Water with Li isotopes

    Science.gov (United States)

    Millot, R.; Desaulty, A. M.

    2015-12-01

    The contribution of human activities such as industries, agriculture and various domestic inputs, becomes more and more significant in the chemical composition of the dissolved load of rivers. Human factors act as a supplementary key process. Therefore the mass-balance for the budget of catchments and river basins include anthropogenic disturbances. In the present study, we investigate waste water tracing by the use of Li isotopes in a small river basin near Orléans in France (l'Egoutier, 15 km² and 5 km long). It is well known that Li has strategic importance for numerous industrial applications including its use in the production of batteries for both mobile devices (computers, tablets, smartphones, etc.) and electric vehicles, but also in pharmaceutical formulations. In the present work, we collected river waters samples before and after the release from a waste water treatment plant connected to an hospital. Lithium isotopic compositions are rather homogeneous in river waters with δ7Li values around -0.5‰ ± 1 along the main course of the stream (n=7). The waste water sample is very different from the natural background of the river basin with Li concentration being twice of the values without pollution and significant heavy lithium contribution (δ7Li = +4‰). These preliminary results will be discussed in relation with factors controlling the distribution of Li and its isotopes in this specific system and compared with the release of other metals such as Pb or Zn.

  2. Repolarization of the action potential enabled by Na+ channel deactivation in PSpice simulation of cardiac muscle propagation

    Directory of Open Access Journals (Sweden)

    Sperelakis Nicholas

    2005-12-01

    Full Text Available Abstract Background In previous studies on propagation of simulated action potentials (APs in cardiac muscle using PSpice modeling, we reported that a second black-box (BB could not be inserted into the K+ leg of the basic membrane unit because that caused the PSpice program to become very unstable. Therefore, only the rising phase of the APs could be simulated. This restriction was acceptable since only the mechanism of transmission of excitation from one cell to the next was being investigated. Methods and results We have now been able to repolarize the AP by inserting a second BB into the Na+ leg of the basic units. This second BB effectively mimicked deactivation of the Na+ channel conductance. This produced repolarization of the AP, not by activation of K+ conductance, but by deactivation of the Na+ conductance. The propagation of complete APs was studied in a chain (strand of 10 cardiac muscle cells, in which various numbers of gap-junction (gj channels (assumed to be 100 pS each were inserted across the cell junctions. The shunt resistance across the junctions produced by the gj-channels (Rgj was varied from 100,000 M? (0 gj-channels to 10,000 M? (1 gj-channel, to 1,000 M? (10 channels, to 100 M? (100 channels, and 10 M? (1000 channels. The velocity of propagation (θ, in cm/s was calculated from the measured total propagation time (TPT, the time difference between when the AP rising phase of the first cell and the last cell crossed -20 mV, assuming a cell length of 150 μm. When there were no gj-channels, or only a few, the transmission of excitation between cells was produced by the electric field (EF, i.e. the negative junctional cleft potential, that is generated in the narrow junctional clefts (e.g. 100 A when the prejunctional membrane fires an AP. When there were many gj-channels (e.g. 1000 or 10,000, the transmission of excitation was produced by local-circuit current flow from one cell to the next through the gj

  3. Waste disposal

    CERN Multimedia

    2006-01-01

    We should like to remind you that you can have all commonplace, conventional waste (combustible, inert, wood, etc.) disposed of by the TS-FM Group. Requests for the removal of such waste should be made by contacting FM Support on tel. 77777 or by e-mail (Fm.Support@cern.ch). For requests to be acted upon, the following information must be communicated to FM Support: budget code to be debited for the provision and removal of the skip / container; type of skip required (1m3, 4 m3, 7 m3, 15 m3, 20 m3, 30 m3); nature of the waste to be disposed of (bulky objects, cardboard boxes, etc.); building concerned; details of requestor (name, phone number, department, group, etc.). We should also like to inform you that the TS-FM Group can arrange for waste to be removed from work-sites for firms under contract to CERN, provided that the prior authorisation of the CERN Staff Member in charge of the contract is obtained and the relevant disposal/handling charges are paid. You are reminded that the selective sorting...

  4. Waste disposal

    CERN Multimedia

    2006-01-01

    We should like to remind you that you can have all commonplace, conventional waste (combustible, inert, wood, etc.) disposed of by the TS-FM Group. Requests for the removal of such waste should be made by contacting FM Support on tel. 77777 or by e-mail (Fm.Support@cern.ch). For requests to be acted upon, the following information must be communicated to FM Support: budget code to be debited for the provision and removal of the skip / container. type of skip required (1m3, 4 m3, 7 m3, 15 m3, 20 m3, 30 m3). nature of the waste to be disposed of (bulky objects, cardboard boxes, etc.). building concerned. details of requestor (name, phone number, department, group, etc.). We should also like to inform you that the TS-FM Group can arrange for waste to be removed from work-sites for firms under contract to CERN, provided that the prior authorisation of the CERN Staff Member in charge of the contract is obtained and the relevant disposal/handling charges are paid. You are reminded that the selective sorting o...

  5. Work plan for the Sangamon River basin, Illinois

    Science.gov (United States)

    Stamer, J.K.; Mades, Dean M.

    1983-01-01

    The U.S. Geological Survey, in cooperation with the Division of Water Resources of the Illinois Department of Transportation and other State agencies, recognizes the need for basin-type assessments in Illinois. This report describes a plan of study for a water-resource assessment of the Sangamon River basin in central Illinois. The purpose of the study would be to provide information to basin planners and regulators on the quantity, quality, and use of water to guide management decisions regarding basin development. Water quality and quantity problems in the Sangamon River basin are associated primarily with agricultural and urban activities, which have contributed high concentrations of suspended sediment, nitrogen, phosphorus, and organic matter to the streams. The impact has resulted in eutrophic lakes, diminished capacity of lakes to store water, low concentrations of dissolved oxygen, and turbid stream and lake waters. The four elements of the plan of study include: (1) determining suspended sediment and nutrient transport, (2) determining the distribution of selected inorganic and organic residues in streambed sediments, (3) determining the waste-load assimilative capacity of the Sangamon River, and (4) applying a hydraulic model to high streamflows. (USGS)

  6. Phase I Focused Corrective Measures Study/Feasibility Study for the L-Area Oil and Chemical Basin (904-83G)

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, E. [Westinghouse Savannah River Company, AIKEN, SC (United States)

    1997-02-01

    This report presents the completed Resource Conservation and Recovery Act (RCRA) Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Focused Corrective Measures Study/Feasibility Study (CMS/FS) for the L-Area Oil and Chemical Basin (LAOCB)/L-Area Acid Caustic Basin (9LAACB) Solid Waste Management Unit/Operable Unit (SWMU/OU) at the Savannah River Site (SRS).

  7. Petroleum exploration potential of Tamtsag Basin

    Institute of Scientific and Technical Information of China (English)

    SUN Guo-qing; GUO Qing-xia; ZHANG Ya-jin; ZHAO Hong-wen

    2004-01-01

    The Tamtsag Basin is located in the extreme eastern portion of the Mongolia. The Basin and its counterpart in China (the Hailar Basin) are united a whole basin on the structural setting. In recent years, the Tamtsag Basin attracts more and more attention with the important exploration discovered in the 19th block by SOCO and in Hailar Basin of China. This paper discusses the exploration potential of Tamtsag Basin from the viewpoint of petroleum geology.

  8. Effect of Au nano-particle aggregation on the deactivation of the AuCl3/AC catalyst for acetylene hydrochlorination.

    Science.gov (United States)

    Dai, Bin; Wang, Qinqin; Yu, Feng; Zhu, Mingyuan

    2015-01-01

    A detailed study of the valence state and distribution of the AuCl3/AC catalyst during the acetylene hydrochlorination deactivation process is described and discussed. Temperature-programmed reduction and X-ray photoelectron spectral analysis indicate that the active Au(3+) reduction to metallic Au(0) is one reason for the deactivation of AuCl3/AC catalyst. Transmission electron microscopy characterization demonstrated that the particle size of Au nano-particles increases with increasing reaction time. The results indicated that metallic Au(0) exhibits considerable catalytic activity and that Au nano-particle aggregation may be another reason for the AuCl3/AC catalytic activity in acetylene hydrochlorination. PMID:25994222

  9. Activation and deactivation of a robust immobilized Cp*Ir-transfer hydrogenation catalyst: a multielement in situ X-ray absorption spectroscopy study.

    Science.gov (United States)

    Sherborne, Grant J; Chapman, Michael R; Blacker, A John; Bourne, Richard A; Chamberlain, Thomas W; Crossley, Benjamin D; Lucas, Stephanie J; McGowan, Patrick C; Newton, Mark A; Screen, Thomas E O; Thompson, Paul; Willans, Charlotte E; Nguyen, Bao N

    2015-04-01

    A highly robust immobilized [Cp*IrCl2]2 precatalyst on Wang resin for transfer hydrogenation, which can be recycled up to 30 times, was studied using a novel combination of X-ray absorption spectroscopy (XAS) at Ir L3-edge, Cl K-edge, and K K-edge. These culminate in in situ XAS experiments that link structural changes of the Ir complex with its catalytic activity and its deactivation. Mercury poisoning and "hot filtration" experiments ruled out leached Ir as the active catalyst. Spectroscopic evidence indicates the exchange of one chloride ligand with an alkoxide to generate the active precatalyst. The exchange of the second chloride ligand, however, leads to a potassium alkoxide-iridate species as the deactivated form of this immobilized catalyst. These findings could be widely applicable to the many homogeneous transfer hydrogenation catalysts with Cp*IrCl substructure. PMID:25768298

  10. [Deactivation by SO2 of transition metal oxides modified low-temperature SCR catalyst for NOx reduction with NH3].

    Science.gov (United States)

    Shen, Bo-xiong; Liu, Ting; Yang, Ting-ting; Xiong, Li-xian; Wang, Jing

    2009-08-15

    MnOx-CeOx/ACF catalyst was prepared by impregnation method, which exhibited high activity for low-temperature selective catalytic reduction of NOx over the temperature range 110-230 degrees C. Experiments results indicated that the catalyst yielded 80% NO conversion at 150 degrees C and 90% at 230 degrees C. The Oxides of Fe,Cu and V were added to the catalysts based on MnOx-CeOx/ACF. The additions of these transition metal oxides had a negative effect on the activity of the catalysts. Compared with MnOx-CeOx/ACF and Cu and V modified catalysts, NO conversion for Fe-MnOx-CeOx/ACF catalyst leveled off at nearly 75% in the first 6 h in the presence of SO2. Two mechanisms of catalyst deactivation by SO2 were discovered by the methods of X-ray photoelectron spectrum (XPS) and Fourier transform infrared spectra (FTIR), indicating that the catalysts were covered by ammonium sulfates and the metal oxides, acting as active components, were also sulfated by SO2 to form metal sulfates.

  11. The control of valence state: How V/TiO2 catalyst is hindering the deactivation using the mechanochemical method

    International Nuclear Information System (INIS)

    Various experiments were conducted to improve durability against SO2 by impregnating the same amount of vanadium in TiO2 which had the various physical properties. According to those catalysts, the degree of deactivation by SO2 had various results, and it was found that the production of unreacted NH3 in selective catalytic reduction reaction should be low. Based on X-ray photoelectron spectroscopy analysis, O2 on-off test, O2 reoxidation test and H2-temperature programmed reduction experiment, the redox capacity of catalyst was improved due to increasing of non-stoichiometric compounds. Such a non-stoichiometric oxide and redox capacity of catalyst can be enhanced by the ball-milling process, and the production of ammonium sulfate salt can be more easily inhibited by the superior oxidation-reduction capacity of catalyst. We found that this result is caused by producing and increasing of Vx+ (x ≤ 4), Tiy+ (y ≤ 3) which are non-stoichiometric chemical species of catalyst.

  12. Large Ferrierite Crystals as Models for Catalyst Deactivation during Skeletal Isomerisation of Oleic Acid: Evidence for Pore Mouth Catalysis.

    Science.gov (United States)

    Wiedemann, Sophie C C; Ristanović, Zoran; Whiting, Gareth T; Reddy Marthala, V R; Kärger, Jörg; Weitkamp, Jens; Wels, Bas; Bruijnincx, Pieter C A; Weckhuysen, Bert M

    2016-01-01

    Large zeolite crystals of ferrierite have been used to study the deactivation, at the single particle level, of the alkyl isomerisation catalysis of oleic acid and elaidic acid by a combination of visible micro-spectroscopy and fluorescence microscopy (both polarised wide-field and confocal modes). The large crystals did show the desired activity, albeit only traces of the isomerisation product were obtained and low conversions were achieved compared to commercial ferrierite powders. This limited activity is in line with their lower external non-basal surface area, supporting the hypothesis of pore mouth catalysis. Further evidence for the latter comes from visible micro-spectroscopy, which shows that the accumulation of aromatic species is limited to the crystal edges, while fluorescence microscopy strongly suggests the presence of polyenylic carbocations. Light polarisation associated with the spatial resolution of fluorescence microscopy reveals that these carbonaceous deposits are aligned only in the larger 10-MR channels of ferrierite at all crystal edges. The reaction is hence further limited to these specific pore mouths. PMID:26611940

  13. A phenomenological model for selective growth of semiconducting single-walled carbon nanotubes based on catalyst deactivation.

    Science.gov (United States)

    Sakurai, Shunsuke; Yamada, Maho; Sakurai, Hiroko; Sekiguchi, Atsuko; Futaba, Don N; Hata, Kenji

    2016-01-14

    A method for the selective semiconducting single-walled carbon nanotube (SWCNT) growth over a continuous range from 67% to 98%, within the diameter range of 0.8-1.2 nm, by the use of a "catalyst conditioning process" prior to growth is reported. Continuous control revealed an inverse relationship between the selectivity and the yield as evidenced by a 1000-times difference in yield between the highest selectivity and non-selectivity. Further, these results show that the selectivity is highly sensitive to the presence of a precise concentration of oxidative and reductive gases (i.e. water and hydrogen), and the highest selectivity occurred along the border between the conditions suitable for high yield and no-growth. Through these results, a phenomenological model has been constructed to explain the inverse relationship between yield and selectivity based on catalyst deactivation. We believe our model to be general, as the fundamental mechanisms limiting selective semiconducting SWCNT growth are common to the previous reports of limited yield. PMID:26660858

  14. Chemical deactivation of Ag/Al2O3 by sulphur for the selective reduction of NOx using hydrocarbons

    International Nuclear Information System (INIS)

    The hydrocarbon-SCR activity of Ag/Al2O3 catalysts is severely deactivated after low temperature (350oC) sulphur ageing in the form of SO2 exposure. Catalysts aged with SO2, NO and hydrocarbon present accumulate a significantly larger amount of SO42- than those aged in the presence of only O2, H2O and SO2 when exposed to an equivalent amount of S. Following sulphation of the catalyst most of the sulphur can be removed by a high temperature (600oC) treatment in the reaction gas. Regeneration in the absence of hydrocarbon is ineffective. The hydrocarbon-SCR activity of the sulphated catalyst using model hydrocarbons such as n-C8H18 can be restored after a high temperature pre-treatment in the reaction gases. However this desulphation process fails to regenerate the hydrocarbon-SCR activity when diesel fuel is used in the activity test. TPR studies show that a major fraction of the sulphur species present in the catalyst is removed by such pre-treatment, but the slight residual amount of sulphur is sufficient to inhibit the activation of the diesel fuel on the Ag catalyst. The nature of the hydrocarbon species present for the hydrocarbon-SCR reaction and during the regeneration strongly influences the activity. In general aromatics such as C7H8 are less effective for reducing NOx and regenerating the sulphated catalyst. (author)

  15. Deactivation mechanism of PtOx/TiO2 photocatalyst towards the oxidation of NO in gas phase

    International Nuclear Information System (INIS)

    This study has been undertaken to investigate the roles of PtO and PtO2 deposits in photocatalytic oxidation of NO over Pt-modified TiO2 catalysts. These photocatalysts were prepared by neutralization method and characterized by XRD, BET, XPS, TEM and FTIR. It was found that Pt dopant existed as PtO and PtO2 particles in as-prepared photocatalysts. And these Pt dopants would change their oxidation states during the photocatalytic oxidation reaction. An in situ XPS study indicated that a portion of PtO2 on the surface of Pt/TiO2 was reduced to PtO under UV irradiation. The migration of electrons to PtO2 particles could separate the electrons and holes, resulting in the improvement of photocatalytic activity. And the depletion of PtO2 by electrons could lead to the deactivation of Pt/TiO2 catalyst. Moreover, PtO particles could be corroded to form Pt2+ ions by HNO3, which was one of the products of photocatalytic oxidation of NO. NO would adsorb on Pt2+ related sites to form Ptn+-NO nitrosyls, retarding photocatalytic oxidation of NO to NO2.

  16. Coking and Deactivation of Catalyst Inhibited by Silanization Modification in Oxidation of Benzene to Phenol with Nitrous Oxide

    Institute of Scientific and Technical Information of China (English)

    翟丕沐; 王立秋; 刘长厚; 张守臣

    2005-01-01

    The main cause to the deactivation of ZSM-5 catalyst, used for oxidation of benzene to phenol (BTOP) by nitrous oxide, is that the carbon deposition on the catalyst surface blocks the mouth of pores of the catalyst.In the experiments, ZSM-5 catalyst was modified by chemical surface deposition of silicon, and then the effect of modification condition on the catalyst activation was studied. The catalyst samples were characterized by XRF,EPS, XRD, TEM, N2 adsorption at low temperature, pyridine adsorption-infrared technique and etc. All the above results show that the uniform SiO2 membrane can be formed on ZSM-5 crystal surface. The SiO2 membrane covers the acid centers on ZSM-5 surface to inhibit surface coking, to avoid or decrease the possibility of ZSM-5 pore blockage so that the catalyst activity and stability can be improved efficiently. The optimum siliconiting conditions determined by the experiments are as follows: 4% load of silanizing agent, volume (ml)/mass (g) ratio of hexane/ZSM-5=15/1, and 16 h of modification time. Compared with the samples without siliconiting treatment,the samples treated under the above optimum condition can increase the productivity of phenol by 14% for 3 h reaction time and by 41% for 6 h reaction time respectively.

  17. Large Ferrierite Crystals as Models for Catalyst Deactivation during Skeletal Isomerisation of Oleic Acid: Evidence for Pore Mouth Catalysis.

    Science.gov (United States)

    Wiedemann, Sophie C C; Ristanović, Zoran; Whiting, Gareth T; Reddy Marthala, V R; Kärger, Jörg; Weitkamp, Jens; Wels, Bas; Bruijnincx, Pieter C A; Weckhuysen, Bert M

    2016-01-01

    Large zeolite crystals of ferrierite have been used to study the deactivation, at the single particle level, of the alkyl isomerisation catalysis of oleic acid and elaidic acid by a combination of visible micro-spectroscopy and fluorescence microscopy (both polarised wide-field and confocal modes). The large crystals did show the desired activity, albeit only traces of the isomerisation product were obtained and low conversions were achieved compared to commercial ferrierite powders. This limited activity is in line with their lower external non-basal surface area, supporting the hypothesis of pore mouth catalysis. Further evidence for the latter comes from visible micro-spectroscopy, which shows that the accumulation of aromatic species is limited to the crystal edges, while fluorescence microscopy strongly suggests the presence of polyenylic carbocations. Light polarisation associated with the spatial resolution of fluorescence microscopy reveals that these carbonaceous deposits are aligned only in the larger 10-MR channels of ferrierite at all crystal edges. The reaction is hence further limited to these specific pore mouths.

  18. Study on the Deactivation Kinetics of Pd(PPh3)2Cl2 in the Monocarbonylation of Benzyl Chloride

    Institute of Scientific and Technical Information of China (English)

    Zumin Qiu; Yunbing He; Huiping Xiao

    2004-01-01

    The deactivation kinetics of Pd(PPh3)2Cl2 in the monocarbonylation of benzyl chloride to synthesize phenylacetic acid is studied in this paper. Solid 1-(2-pyridylazo)-2-naphthol (PAN) is used as the colouring agent, and the concentration of Pd(PPh3)2Cl2 in the system is measured through absorptiometry.The result shows that the optimum condition of the chromogenic reaction between Pd2+ and PAN is:0.5 ml of 0.04% PAN added to 10 ml of Pd2+ solution (1.0×10-6-2.0×10-5 mol/L), and heated in a constant temperature water bath at 40 ℃ for about 30 min, with pH of the solution being about 3.0.The molar coefficient of absorption is 1.384×104 L/(mol.cm); the orders of the hydrolytic reaction to the concentration of Pd(PPh3)2Cl2, PPh3, phenylacetic acid and NaOH are 0.5, minus 0.8, 2 and 1.2,respectively. The activation energy (E) of the hydrolytic reaction is 75.59 k J/mol, and the pre-exponential factor is 1.68×1012.

  19. Kinetics and deactivation mechanisms of the thermal decomposition of methane in hydrogen and carbon nanofiber Co-production over Ni-supported Y zeolite-based catalysts

    International Nuclear Information System (INIS)

    Highlights: • Methane cracking requires an optimum temperature range of 550–600 °C for H2 yield. • Reaction order and activation energy were 2.65 and 61.77 kJ/mol, respectively. • At 600 °C, a 496.40 gc/gNi of carbon was obtained using 30% Ni/Y zeolite catalysts. • Deactivation order and activation energy were 1.2, and 94.03 kJ/mol, respectively. • Produced filamentous carbon has the same diameter as the metallic nickel itself. - Abstract: This paper reports the reaction rate and deactivation kinetics of methane decomposition by using zeolite Y as the support and Ni as the active phase in a fixed bed reactor at a temperature range of 500 °C to 650 °C and at partial pressures of methane/nitrogen mixture of 0.2, 0.35, and 0.5 atm. The reaction order and activation energy were 2.65 and 61.77 kJ/mol, respectively. To quantify catalytic activity, carbon deposition rate was taken into consideration, which showed that the actual and thermodynamically predicted accumulated carbons were in good balance. Deactivation order, methane concentration dependency, and activation energy were 1.2, −1.28, and 94.03 kJ/mol, respectively. The kinetic experiment indicates that the optimum temperature range should be maintained to achieve the highest performance from 30% Ni/Y zeolite in terms of hydrogen formation rate, average hydrogen formation rate, total hydrogen formation, average carbon formation, total carbon formation, and carbon formation rate. TEM and XRD analysis were performed to characterize the deactivated, fresh, and calcined catalysts, and the results indicated that the formed filamentous carbon has the same diameter as the metallic nickel itself. The influence of volume hourly space velocity (VHSV) on methane conversion and carbon nanofiber production was also discussed

  20. Enhancing the Deactivation Durability of Nano-sized HZSM-5 for Aromatization by Adjusting its Ratio of Lewis/Brφnsted Acid Sites

    Institute of Scientific and Technical Information of China (English)

    Zhou Bo XU; Hong Chen GUO; Xiang Sheng WANG; Pei Qing ZHANG; Le Ping ZHAO; Yong Kang HU

    2004-01-01

    Ratio of Lewis/Br(nsted acid sites (Cl/Cb) on the surface of nano-sized HZSM-5 was successfully manipulated by means of steaming and acid leaching. Significant enhancement of the deactivation durability of nano-sized HZSM-5 in the aromatization of fluid catalytic cracking (FCC) gasoline olefins seems to be closely related to the increase of Lewis/Br(nsted acid sites ratio.

  1. Deactivation of Bromelain in Pineapple Juice and analysing its Physico-Chemical and Organoleptic properties for successful commercialization via FMCG Industries in Indian Subcontinent.

    OpenAIRE

    Bhaskar Mitra; Kunal Garg; Suneetha V

    2013-01-01

    The plan of this investigation was formulated to study the biochemical and physical attributes of juice extracted from the pulp which has high sugar (glucose and fructose) content and adequate moisture. Pineapple confers health benefit on the host as it contains huge quantities of vitamin C and other antioxidants. Deactivation of bromelain was also performed so that there are no hindrances in the juice manufacturing process. Sodium meta-bisulphite was also added to increase the shelf life of ...

  2. When higher activations reflect lower deactivations: a PET study in Alzheimer’s disease during encoding and retrieval in episodic memory

    Directory of Open Access Journals (Sweden)

    Alexandre eBejanin

    2012-05-01

    Full Text Available The aim of the present study was to explore the cerebral substrates of episodic memory disorders in Alzheimer’s disease (AD and investigate patients' hyperactivations frequently reported in the functional imaging literature. It remains unclear whether some of these hyperactivations reflect compensatory mechanisms or deactivation disturbances in the default mode network. Using positron emission tomography (15O-H2O, cerebral blood flow was measured in eleven ADs and twelve healthy elderly controls at rest and during encoding and stem-cued recall of verbal items. We performed subtractions analyses between the experimental and control conditions between groups. The average signal was extracted in regions showing hyperactivation in AD patients versus controls in both contrasts. To determine whether hyperactivations occurred in regions that were activated or deactivated during the memory tasks, we compared signal intensities between the experimental conditions versus rest. Our results showed reduced activation in ADs compared to controls in several core episodic memory regions, including the medial temporal structures, during both encoding and retrieval. ADs also showed hyperactivations compared to controls in a set of brain areas. Further analyses conducted on the signal extracted in these areas indicated that most of these hyperactivations in ADs actually reflected a failure of deactivation. Indeed, almost all of these regions were significantly more activated at rest than during the experimental conditions in controls, only one region presented a similar pattern of deactivation in ADs. Altogether, our findings suggest that hyperactivations in AD must be interpreted with caution and may not systematically reflect compensatory mechanisms. Although there has been evidence supporting the existence of genuine compensatory mechanisms, dysfunction within the default mode network may be responsible for part of the apparent hyperactivations reported in

  3. Canterbury Basin Sea Level

    OpenAIRE

    Fulthorpe, C. S.; Institute for Geophysics John A. and Katherine G. Jackson School of Geosciences The University of Texas at Austin J.J. Pickle Research Campus, Building 196 (ROC) 10100 Burnet Road (R2200) Austin TX 78758-4445 USA; Hoyanagi, K.; Department of Geology Faculty of Science Shinshu University 3-1-1 Asahi, Matsumoto 390-8621 Japan; Blum, P.; United States Implementing Organization Integrated Ocean Drilling Program Texas A&M University 1000 Discovery Drive College Station TX 77845 USA; Guèrin, G.; Borehole Research Group Lamont-Doherty Earth Observatory of Columbia University PO Box 1000, 61 Route 9W Palisades NY 10964 USA; Slagle, A. L.; Borehole Research Group Lamont-Doherty Earth Observatory of Columbia University PO Box 1000, 61 Route 9W Palisades NY 10964 USA; Blair, S. A.; Department of Geological Sciences Florida State University 006 Carraway Building Tallahassee FL 32306 USA; Browne, G. H.; Hydrocarbon Section GNS Science PO Box 30368 Lower Hutt New Zealand; Carter, R. M.; Marine Geophysical Laboratory James Cook University of North Queensland Townsville QLD 4811 Australia; Ciobanu, M.; Laboratoire de Microbiologie des Environnements Extrêmes CNRS UMR-6197 Institut Universitaire Européen de la Mer Technopole Brest-Iroise Plouzane 29280 France; Claypool, G. E.; Organic Geochemist 8910 West 2nd Avenue Lakewood CO 80226 USA; Crundwell, M. P.; New Zealand Observer/Paleontologist (foraminifers) Paleontology and Environmental Change Section GNS Science PO Box 30368 Lower Hutt New Zealand; Dinarès-Turell, J.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Ding, X.; School of Marine Sciences China University of Geosciences (Beijing) 29 XueYuan Road, Haidian District Beijing P.R. China; George, S. C.; Department of Earth and Planetary Sciences Macquarie University Sydney NSW 2109 Australia; Hepp, D. A.; MARUM – Center for Marine Environmental Sciences and Department of Geosciences University of Bremen Leobener Strasse MARUM Building, Room 2230 28359 Bremen Germany

    2010-01-01

    Integrated Ocean Drilling Program (IODP) Expedition 317 was devoted to understanding the relative importance of global sea level (eustasy) versus local tectonic and sedimentary processes in controlling continental margin sedimentary cycles. The expedition recovered sediments from the Eocene to recent period, with a particular focus on the sequence stratigraphy of the late Miocene to recent, when global sea level change was dominated by glacioeustasy. Drilling in the Canterbury Basin,...

  4. Case Study in Corporate Memory Recovery: Hanford Tank Farms Miscellaneous Underground Waste Storage Tanks - 15344

    Energy Technology Data Exchange (ETDEWEB)

    Washenfelder, D. J.; Johnson, J. M.; Turknett, J. C.; Barnes, T. J.; Duncan, K. G.

    2015-01-07

    In addition to managing the 177 underground waste storage tanks containing 212,000 m3 (56 million gal) of radioactive waste at the U. S. Department of Energy’s Hanford Site 200 Area Tank Farms, Washington River Protection Solutions LLC is responsible for managing numerous small catch tanks and special surveillance facilities. These are collectively known as “MUSTs” - Miscellaneous Underground Storage Tanks. The MUSTs typically collected drainage and flushes during waste transfer system piping changes; special surveillance facilities supported Tank Farm processes including post-World War II uranium recovery and later fission product recovery from tank wastes. Most were removed from service following deactivation of the single-shell tank system in 1980 and stabilized by pumping the remaining liquids from them. The MUSTs were isolated by blanking connecting transfer lines and adding weatherproofing to prevent rainwater entry. Over the next 30 years MUST operating records were dispersed into large electronic databases or transferred to the National Archives Regional Center in Seattle, Washington. During 2014 an effort to reacquire the historical bases for the MUSTs’ published waste volumes was undertaken. Corporate Memory Recovery from a variety of record sources allowed waste volumes to be initially determined for 21 MUSTs, and waste volumes to be adjusted for 37 others. Precursors and symptoms of Corporate Memory Loss were identified in the context of MUST records recovery.

  5. New approaches to variable displacement. What will be next after cylinder deactivation on gasoline engines?; Neue Wege zum variablen Hubvolumen. Was kommt nach der Zylinderabschaltung am Ottomotor?

    Energy Technology Data Exchange (ETDEWEB)

    Ross, J.; Grigoriadis, P.; Dingel, O.; Werler, A.; Neukirchner, H. [IAV GmbH, Chemnitz (Germany)

    2012-11-01

    Fuel economy results close to those of diesel engines could be obtained for the gasoline (Otto) engine in the New European Driving Cycle (NEDC) by means of cylinder deactivation (CDA). This can be achieved without renouncing the classical benefits of the gasoline engine such as low noise and emission levels or its typical liveliness. In cycles providing higher load fractions, the positive fuel economy effect of CDA can turn out to be much smaller. Additionally, shutting off cylinders by deactivating the intake and exhaust valves does not lead to significantly reduced friction torque in the engine. This article therefore discusses additional measures aimed at further decreasing fuel consumption such as the partial deactivation of the cranktrain, an asymmetric displacement split and a combination with variable valve lift. The fuel consumption scenarios discussed are based on experimental and simulation data from a turbocharged 1.6l four-cylinder gasoline engine. The impact of the measures described on vibration characteristics and the harshness of the engine is considered in the analysis of the fuel consumption potential. Design solutions for the suggested measures are illustrated and their impact on friction torque and fuel economy in cycles with higher load distribution is also demonstrated. (orig.)

  6. Possibilities for recycling cellulases after use in cotton processing: part I: Effects of end-product inhibition, thermal and mechanical deactivation, and cellulase depletion by adsorption.

    Science.gov (United States)

    Azevedo, Helena; Bishop, David; Cavaco-Paul, Artur

    2002-04-01

    Preliminary recycling experiments with cellulase enzymes after cotton treatments at 50 degrees C showed that activity remaining in the treatment liquors was reduced by about 80% after five recycling steps. The potential problems of end-product inhibition, thermal and mechanical deactivation, and the loss of some components of the cellulase complex by preferential and or irreversible adsorption to cotton substrates were studied. End-product inhibition studies showed that the build-up of cellobiose and glucose would be expected to cause no more than 40% activity loss after five textile treatment cycles. Thermal and mechanical treatments of cellulases suggested that the enzymes start to be deactivated at 60 degrees C and agitation levels similar to those used in textile processing did not cause significant enzyme deactivation. Analysis of cellulase solutions, by fast protein liquid chromatography, before and after adsorption on cotton fabrics, suggested that the cellobiohydrolase II (Cel6A) content of the cellulase complex was reduced, relative to the other components, by preferential adsorption. This would lead to a marked reduction in activity after several treatment cycles and top-up with pure cellobiohydrolase II would be necessary unless this component is easily recoverable from the treated fabric.

  7. Waste prevention action nets

    OpenAIRE

    Corvellec, Hervé; Czarniawska, Barbara

    2013-01-01

    Although waste prevention is considered the best possible waste management option in the European waste hierarchy model, it is unclear what constitutes waste prevention. To address this lack of clarity, this text presents an analysis of four Swedish case studies of waste prevention: a waste management company selling waste prevention services; the possibility offered to Swedish households to opt out of receiving unaddressed promotional material; a car-sharing program; and a re-...

  8. Solid waste management

    OpenAIRE

    Srebrenkoska, Vineta; Golomeova, Saska; Krsteva, Silvana

    2013-01-01

    Waste is unwanted or useless materials from households, industry, agriculture, hospitals. Waste materials in solid state are classified as solid waste. Increasing of the amount of solid waste and the pressure what it has on the environment, impose the need to introduce sustainable solid waste management. Advanced sustainable solid waste management involves several activities at a higher level of final disposal of the waste management hierarchy. Minimal use of material and energy resources ...

  9. Nuclear waste

    International Nuclear Information System (INIS)

    DOE estimates that disposing of radioactive waste from civilian nuclear power plants and its defense-related nuclear facilities could eventually end up costing $32 billion. To pay for this, DOE collects fees from utilities on electricity generated by nuclear power plants and makes payments from its defense appropriation. This report states that unless careful attention is given to its financial condition, the nuclear waste program is susceptible to future shortfalls. Without a fee increase, the civilian-waste part of the program may already be underfunded by at least $2.4 billion (in discounted 1988 dollars). Also, DOE has not paid its share of cost-about $480 million-nor has it disclosed this liability in its financial records. Indexing the civilian fee to the inflation rate would address one major cost uncertainty. However, while DOE intends to do this at an appropriate time, it does not use a realistic rate of inflation as its most probable scenario in assessing whether that time has arrived

  10. K-Basin gel formation studies

    Energy Technology Data Exchange (ETDEWEB)

    Beck, M.A.

    1998-07-23

    A key part of the proposed waste treatment for K Basin sludge is the elimination of reactive uranium metal by dissolution in nitric acid (Fkirnent, 1998). It has been found (Delegard, 1998a) that upon nitric acid dissolution of the sludge, a gel sometimes forms. Gels are known to sometimes impair solid/liquid separation and/or material transfer. The purpose of the work reported here is to determine the cause(s) of the gel formation and to determine operating parameters for the sludge dissolution that avoid formation of gel. This work and related work were planned in (Fkunent, 1998), (Jewett, 1998) and (Beck, 1998a). This report describes the results of the tests in (Beck, 1998a) with non-radioactive surrogates.

  11. The kinetics of activation and deactivation in the process of water ozonising used for advanced oxidation of the dust waste from moulding sands

    OpenAIRE

    A. Baliński

    2009-01-01

    Adding coal dust and organic carriers of the lustrous carbon to bentonite-bonded moulding sands in amounts justified by thetechnological regime and the use of cores and protective coatings based on organic compounds create serious threats to the environment.During thermal destruction of the individual components of moulding and core sands, some toxic organic compounds are emitted. They formthe majority of the Hazardous Air Pollutants (HAPs), and include mainly compounds like benzene, toluene,...

  12. Regeneration of Pt-catalysts deactivated in municipal waste flue gas with H2/N2 and the effect of regeneration step on the SCR catalyst

    DEFF Research Database (Denmark)

    Due-Hansen, Johannes; Rasmussen, Søren Birk; Kustov, Arkadii;

    stream, i.e. by in situ treatment of the Pt-catalyst by reductive H2-gas. However, introduction of H2 gas in the gas stream could also affect other units in the tail pipe gas cleaning system. Of special interest here, is the effect of hydrogen gas on the performance of the deNOx + SCR catalytic process...

  13. Regeneration of Pt-catalysts deactivated in municipal waste flue gas with H2/N2 and the effect of regeneration step on the SCR catalyst

    DEFF Research Database (Denmark)

    Due-Hansen, Johannes; Rasmussen, Søren Brik; Kustov, Arkady;

    on reduction with hydrogen. This procedure had negligible effect on the performance of the SCR catalyst. After treatment with 2% H2, 8% O2 in N2 for one hour, a slight better NO SCR activity was observed due to increase in the concentration V4+ sites. However, after exposure in normal NO SCR gases the activity...

  14. Alkali deactivation of high-dust SCR catalysts used for NOx reduction exposed to flue gas from 100MW-scale biofuel and peat fired boilers. Influence of flue gas composition

    International Nuclear Information System (INIS)

    Deactivation of vanadium-titanium deNOx SCR (selective catalytic reduction) catalysts in high-dust position have been investigated in three 100MW-scale boilers during biofuel and peat combustion. The deactivation of the catalyst samples has been correlated to the corresponding flue gas composition in the boilers. To investigate the effect on catalyst deactivation a sulphate-containing additive was sprayed into one of the furnaces. Increased alkali content on the SCR catalyst samples decreased the catalytic deNOx activity. The study has shown a linear correlation between exposure time in the boilers and alkali concentration (mainly potassium) on the samples. The results imply that mainly alkali in ultra fine particles (<100nm) in the flue gas increased the alkali accumulation on the catalyst samples. Low correlation was found between particles larger than 100nm and the catalyst deactivation. It was not possible to decrease the deactivation of the catalyst samples by the sulphate-containing additive. Although the additive had an effect in sulphating potassium chloride to potassium sulphate, it did not decrease the amount of potassium in ultra fine particles or the deactivation of the catalyst samples. (author)

  15. Waste management and security

    International Nuclear Information System (INIS)

    Full text: Waste Management (WM) has become an applied science. It is used at the point of generation, at the centralized treatment facilities, and at the disposal sites. In the government and private sector, much research is being done in waste by-product utilization. Some of the important factors that affect waste are sources of waste, classification of waste, waste treatment and conditioning, minimization of waste, laws and regulations governing waste and present and future issues. WM has become a career with a promising future as the cost of waste disposal increases tremendously. Scientists have started working on waste minimization and most organizations implement a formalized waste minimization program of their own. The waste disposal is approached in an analytical manner and this paper describes development in radioactive waste disposal and safe transportation practices

  16. Rethinking the waste hierarchy

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, C.; Vigsoe, D. (eds.)

    2005-03-01

    There is an increasing need to couple environmental and economic considerations within waste management. Consumers and companies alike generate ever more waste. The waste-policy challenges of the future lie in decoupling growth in waste generation from growth in consumption, and in setting priorities for the waste management. This report discusses the criteria for deciding priorities for waste management methods, and questions the current principles of EU waste policies. The basis for the discussion is the so-called waste hierarchy which has dominated the waste policy in the EU since the mid-1970s. The waste hierarchy ranks possible methods of waste management. According to the waste hierarchy, the very best solution is to reduce the amount of waste. After that, reuse is preferred to recycling which, in turn, is preferred to incineration. Disposal at a landfill is the least favourable solution. (BA)

  17. Other Special Waste

    DEFF Research Database (Denmark)

    Brogaard, Line Kai-Sørensen; Christensen, Thomas Højlund

    2011-01-01

    In addition to the main types of special waste related to municipal solid waste (MSW) mentioned in the previous chapters (health care risk waste, WEEE, impregnated wood, hazardous waste) a range of other fractions of waste have in some countries been defined as special waste that must be handled...... separately from MSW. Some of these other special wastes are briefly described in this chapter with respect to their definition, quantity and composition, and management options. The special wastes mentioned here are batteries, tires, polyvinylchloride (PVC) and food waste....

  18. Multiple oscillatory modes of the Argentine Basin. Part II. The spectral origin of the basin modes

    NARCIS (Netherlands)

    Weijer, W.; Vevier, F.; Gille, S.T.; Dijkstra, H.A.

    2007-01-01

    In this paper the spectrum of barotropic basin modes of the Argentine Basin is shown to be connected to the classical Rossby basin modes of a flat-bottom (constant depth), rectangular basin. First, the spectrum of basin modes is calculated for the Argentine Basin, by performing a normal-mode analysi

  19. Intracontinental basins and strong earthquakes

    Institute of Scientific and Technical Information of China (English)

    邓起东; 高孟潭; 赵新平; 吴建春

    2004-01-01

    The September 17, 1303 Hongtong M=8 earthquake occurred in Linfen basin of Shanxi down-faulted basin zone. It is the first recorded M=8 earthquake since the Chinese historical seismic records had started and is a great earthquake occurring in the active intracontinental basin. We had held a Meeting of the 700th Anniversary of the 1303 Hongtong M=8 Earthquake in Shanxi and a Symposium on Intracontinental Basins and Strong Earthquakes in Taiyuan City of Shanxi Province on September 17~18, 2003. The articles presented on the symposium discussed the relationships between active intracontinental basins of different properties, developed in different regions, including tensional graben and semi-graben basins in tensile tectonic regions, compression-depression basins and foreland basins in compressive tectonic regions and pull-apart basins in strike-slip tectonic zones, and strong earthquakes in China. In this article we make a brief summary of some problems. The articles published in this special issue are a part of the articles presented on the symposium.

  20. Meteorological, stream-discharge, and water-quality data for 1986 through 1991 from two small basins in central Nevada

    Energy Technology Data Exchange (ETDEWEB)

    McKinley, P.W.; Oliver, T.A.

    1994-04-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, is investigating the volcanic tuffs of Yucca Mountain, Nevada, for their suitability as storage sites for nuclear waste. Two small basins, measuring less than 2 square miles, were studied to determine the volume of precipitation available for recharge to the ground water. The semiarid 3 Springs Basin is located to the east of Kawich Peak in the Kawich Range east of Tonopah, Nevada. Stewart Basin is a subalpine drainage basin north of Arc Dome in the Toiyabe Range north of Tonopah, Nevada. This publication presents the meteorological, stream-discharge, and water-quality data collected during the study. Meteorological data collected include air temperature, soil temperature, solar radiation, and relative humidity. Stream-discharge data were collected from the surface-water outlet of each basin. Water-quality data are chemical analyses of water samples collected from surface- and ground-water sources. Data were collected throughout the two basins. Each basin has a meteorological station located in the lower and upper reaches of the basin. Hydrologic records include stream-discharge and water-quality data from the lower meteorological site and water-quality data from springs within the basins. Meteorological data are available from the lower sites from the winter of 1986 through the fall of 1991. Periods of data collection were shorter for additional sites in the basin.