Functioning of metal contaminated garden soil after remediation

International Nuclear Information System (INIS)

Jelusic, Masa; Grcman, Helena; Vodnik, Dominik; Suhadolc, Metka; Lestan, Domen

2013-01-01

The effect of remediation using three EDTA doses (10, 30, 60 mmol kg −1 ) on soil functioning was assessed using column experiment and Brassica rapa. Soil washing removed up to 77, 29 and 72% of metals from soil contaminated with 1378, 578 and 8.5 mg kg −1 of Pb, Zn and Cd, respectively. Sequential extraction indicated removal from the carbonate soil fraction. Metal oral-accessibility from the stomach phase was reduced by up to 75 and from the small intestine by up to 79% (Pb). Part of metals (up to 0.8% Cd) was lost due to leaching from columns. Remediation reduced toxic metal soil-root transfer by up to 61% but did not prevent metal accumulation in leaves. The fitness of plants grown on EDTA washed soils (gas exchange, fluorescence) was not compromised. Remediation initially reduced the soil DNA content (up to 29%, 30 mmol kg −1 EDTA) and changed the structure of microbial population. -- Highlights: ► Toxic metals contaminated garden soil was remediated in a pilot-scale. ► EDTA washing reduced soil Pb, Zn and Cd content and bioavailability. ► Remediated soil preserved the function of plant and microbial substrate. ► Remediation didn't prevent the accumulation of toxic metals in the test plant. -- EDTA soil washing effectively removed toxic metals and reduced their transfer from the soil to plant roots but did not prevent their accumulation in leaves

Micro-layers of polystyrene film preventing metal oxidation: implications in cultural heritage conservation

Science.gov (United States)

Giambi, Francesca; Carretti, Emiliano; Dei, Luigi; Baglioni, Piero

2014-12-01

Protection of surfaces directly exposed to the detrimental action of degradative agents (i.e. oxygen, air pollutants and bacteria) is one of the most important challenges in the field of conservation of works of art. Metallic objects are subjected to specific surface corrosion phenomena that, over the years, make mandatory the research of innovative materials that should avoid the direct contact between the metal surface and the weathering agents. In this paper, the set-up, characterisation and application of a new reversible material for preserving metal artefacts are reported. Micro-layers constituted of low-adhesive polystyrene (PS) films obtained from recycling waste packaging materials made of expanded PS were studied. The morphology and thickness of PS films were characterised by optical, atomic force and scanning electron microscopy (SEM). A further check on thickness was carried out by means of visible spectrophotometry doping the films with a hydrophobic dye. Thermal properties of the PS micro-layers were studied by means of differential scanning calorimetry coupled with optical microscopy. Permeability of the PS films to water vapour was also determined. The potential of the low-adhesive PS films, that enabled an easy removal in case of film deterioration, for preventing metal oxidation was investigated on brass specimens by simulating standard artificial corrosion programmes. Morphological and chemical (coupling the energy-dispersive X-rays spectrometry to SEM measurements) analyses carried out on these metal samples showed promising results in terms of surface protection against corrosion.

The efficacy of different anti-microbial metals at preventing the formation of, and eradicating bacterial biofilms of pathogenic indicator strains.

Science.gov (United States)

Gugala, Natalie; Lemire, Joe A; Turner, Raymond J

2017-06-01

The emergence of multidrug-resistant pathogens and the prevalence of biofilm-related infections have generated a demand for alternative anti-microbial therapies. Metals have not been explored in adequate detail for their capacity to combat infectious disease. Metal compounds can now be found in textiles, medical devices and disinfectants-yet, we know little about their efficacy against specific pathogens. To help fill this knowledge gap, we report on the anti-microbial and antibiofilm activity of seven metals: silver, copper, titanium, gallium, nickel, aluminum and zinc against three bacterial strains, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli. To evaluate the capacity of metal ions to prevent the growth of, and eradicate biofilms and planktonic cells, bacterial cultures were inoculated in the Calgary Biofilm Device (minimal biofilm eradication concentration) in the presence of the metal salts. Copper, gallium and titanium were capable of preventing planktonic and biofilm growth, and eradicating established biofilms of all tested strains. Further, we observed that the efficacies of the other tested metal salts displayed variable efficacy against the tested strains. Further, contrary to the enhanced resistance anticipated from bacterial biofilms, particular metal salts were observed to be more effective against biofilm communities versus planktonic cells. In this study, we have demonstrated that the identity of the bacterial strain must be considered before treatment with a particular metal ion. Consequent to the use of metal ions as anti-microbial agents to fight multidrug-resistant and biofilm-related infections increases, we must aim for more selective deployment in a given infectious setting.

Combustion of metals, prevention and fire fighting

International Nuclear Information System (INIS)

Mellottee, H.

1991-01-01

The paper reviews the knowledge on metal combustion. Few works are devoted on metals such as magnesium or titanium. On the contrary liquid metals used as coolants, especially sodium, are much more studied. Results obtained on pool fires and spray fires are briefly given for global safety analysis of LMFBR. 11 refs

Liquid Metal Engineering and Technology. Volume 1

International Nuclear Information System (INIS)

1988-01-01

These proceedings of the fourth international conference on liquid metal engineering and technology volume 1, are devided into 3 sections bearing on: - Apparatus and components for liquid metal (29 papers) - Liquid metal leaks, fires and fumes (10 papers) - Cleaning, decontamination, waste disposal (14 papers) [fr

Transient Mass and Thermal Transport during Methane Adsorption into the Metal-Organic Framework HKUST-1.

Science.gov (United States)

Babaei, Hasan; McGaughey, Alan J H; Wilmer, Christopher E

2018-01-24

Methane adsorption into the metal-organic framework (MOF) HKUST-1 and the resulting heat generation and dissipation are investigated using molecular dynamics simulations. Transient simulations reveal that thermal transport in the MOF occurs two orders of magnitude faster than gas diffusion. A large thermal resistance at the MOF-gas interface (equivalent to 127 nm of bulk HKUST-1), however, prevents fast release of the generated heat. The mass transport resistance at the MOF-gas interface is equivalent to 1 nm of bulk HKUST-1 and does not present a bottleneck in the adsorption process. These results provide important insights into the application of MOFs for gas storage applications.

Casting technology for manufacturing metal rods from simulated metallic spent fuels

Science.gov (United States)

Leeand, Y. S.; Lee, D. B.; Kim, C. K.; Shin, Y. J.; Lee, J. H.

2000-09-01

A uranium metal rod 13.5 mm in diameter and 1,150 mm long was produced from simulated metallic spent fuels with advanced casting equipment using the directional-solidification method. A vacuum casting furnace equipped with a four-zone heater to prevent surface oxidation and the formation of surface shrinkage holes was designed. By controlling the axial temperature gradient of the casting furnace, deformation by the surface shrinkage phenomena was diminished, and a sound rod was manufactured. The cooling behavior of the molten uranium was analyzed using the computer software package MAGMAsoft.

Treatment and Prevention of Pandemic H1N1 Influenza.

Science.gov (United States)

Rewar, Suresh; Mirdha, Dashrath; Rewar, Prahlad

2015-01-01

Swine influenza is a respiratory infection common to pigs worldwide caused by type A influenza viruses, principally subtypes H1N1, H1N2, H2N1, H3N1, H3N2, and H2N3. Swine influenza viruses also can cause moderate to severe illness in humans and affect persons of all age groups. People in close contact with swine are at especially high risk. Until recently, epidemiological study of influenza was limited to resource-rich countries. The World Health Organization declared an H1N1 pandemic on June 11, 2009, after more than 70 countries reported 30,000 cases of H1N1 infection. In 2015, incidence of swine influenza increased substantially to reach a 5-year high. In India in 2015, 10,000 cases of swine influenza were reported with 774 deaths. The Centers for Disease Control and Prevention recommend real-time polymerase chain reaction as the method of choice for diagnosing H1N1. Antiviral drugs are the mainstay of clinical treatment of swine influenza and can make the illness milder and enable the patient to feel better faster. Antiviral drugs are most effective when they are started within the first 48 hours after the clinical signs begin, although they also may be used in severe or high-risk cases first seen after this time. The Centers for Disease Control and Prevention recommends use of oseltamivir (Tamiflu, Genentech) or zanamivir (Relenza, GlaxoSmithKline). Prevention of swine influenza has 3 components: prevention in swine, prevention of transmission to humans, and prevention of its spread among humans. Because of limited treatment options, high risk for secondary infection, and frequent need for intensive care of individuals with H1N1 pneumonia, environmental control, including vaccination of high-risk populations and public education are critical to control of swine influenza out breaks. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Recent Advances in Antimicrobial Hydrogels Containing Metal Ions and Metals/Metal Oxide Nanoparticles

Directory of Open Access Journals (Sweden)

Fazli Wahid

2017-11-01

Full Text Available Recently, the rapid emergence of antibiotic-resistant pathogens has caused a serious health problem. Scientists respond to the threat by developing new antimicrobial materials to prevent or control infections caused by these pathogens. Polymer-based nanocomposite hydrogels are versatile materials as an alternative to conventional antimicrobial agents. Cross-linking of polymeric materials by metal ions or the combination of polymeric hydrogels with nanoparticles (metals and metal oxide is a simple and effective approach for obtaining a multicomponent system with diverse functionalities. Several metals and metal oxides such as silver (Ag, gold (Au, zinc oxide (ZnO, copper oxide (CuO, titanium dioxide (TiO2 and magnesium oxide (MgO have been loaded into hydrogels for antimicrobial applications. The incorporation of metals and metal oxide nanoparticles into hydrogels not only enhances the antimicrobial activity of hydrogels, but also improve their mechanical characteristics. Herein, we summarize recent advances in hydrogels containing metal ions, metals and metal oxide nanoparticles with potential antimicrobial properties.

Exploring multi-metal biosorption by indigenous metal-hyperresistant Enterobacter sp. J1 using experimental design methodologies

International Nuclear Information System (INIS)

Lu, W.-B.; Kao, W.-C.; Shi, J.-J.; Chang, J.-S.

2008-01-01

A novel experimental design, combining mixture design and response surface methodology (RSM), was developed to investigate the competitive adsorption behavior of lead, copper and cadmium by an indigenous isolate Enterobacter sp. J1 able to tolerate high concentrations of a variety of heavy metals. Using the proposed combinative experimental design, two different experiment designs in a ternary metal biosorption system can be integrated to a succinct experiment and the number of experimental trials was markedly reduced from 38 to 26 by reusing the mutual experimental data. Triangular contour diagrams and triangular three-dimensional surface plots were generated to describe the ternary metal biosorption equilibrium data in mixture design systems. The results show that the preference of metal sorption of Enterobacter sp. J1 decreased in the order of Pb 2+ > Cu 2+ > Cd 2+ . The presence of other metals resulted in a competitive effect. The influence of the other two metals in ternary metal biosorption system can be easily determined by comparing the stray distance from the single metal biosorption. The behavior of competitive biosorption was successfully described and predicted using a combined Langmuir-Freundlich model along with new three-dimensional contour-surface plots

Exploring multi-metal biosorption by indigenous metal-hyperresistant Enterobacter sp. J1 using experimental design methodologies

Energy Technology Data Exchange (ETDEWEB)

Lu, W.-B. [Department of Cosmetic Science, Chung Hwa University of Medical Technology, Tainan, Taiwan (China); Kao, W.-C.; Shi, J.-J. [Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan (China); Chang, J.-S. [Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan (China)], E-mail: changjs@mail.ncku.edu.tw

2008-05-01

A novel experimental design, combining mixture design and response surface methodology (RSM), was developed to investigate the competitive adsorption behavior of lead, copper and cadmium by an indigenous isolate Enterobacter sp. J1 able to tolerate high concentrations of a variety of heavy metals. Using the proposed combinative experimental design, two different experiment designs in a ternary metal biosorption system can be integrated to a succinct experiment and the number of experimental trials was markedly reduced from 38 to 26 by reusing the mutual experimental data. Triangular contour diagrams and triangular three-dimensional surface plots were generated to describe the ternary metal biosorption equilibrium data in mixture design systems. The results show that the preference of metal sorption of Enterobacter sp. J1 decreased in the order of Pb{sup 2+} > Cu{sup 2+} > Cd{sup 2+}. The presence of other metals resulted in a competitive effect. The influence of the other two metals in ternary metal biosorption system can be easily determined by comparing the stray distance from the single metal biosorption. The behavior of competitive biosorption was successfully described and predicted using a combined Langmuir-Freundlich model along with new three-dimensional contour-surface plots.

Liquid metal cold trap

International Nuclear Information System (INIS)

Hundal, R.

1976-01-01

A cold trap assembly for removing impurities from a liquid metal is described. A hole between the incoming impure liquid metal and purified outgoing liquid metal acts as a continuous bleed means and thus prevents the accumulation of cover gases within the cold trap assembly

BaxSr1-xTi1.02O3 metal-insulator-metal capacitors on planarized alumina substrates

NARCIS (Netherlands)

Tiggelman, M.P.J.; Reimann, K.; Klee, M.; Mauczok, R.; Keur, W.; Hueting, Raymond Josephus Engelbart

2010-01-01

Nanocrystalline barium strontium titanate (BaxSr1−xTi1.02O3) thin films with a barium content of x=0.8, 0.9 and 1 have been fabricated in a metal–insulator–metal configuration on glass-planarized alumina substrates. Cost-effective processing measures have been utilized by using poly-crystalline

Soil and groundwater contamination with heavy metals at two scrap iron and metal recycling facilities

DEFF Research Database (Denmark)

Jensen, Dorthe Lærke; Holm, P. E.; Christensen, Thomas Højlund

2000-01-01

Field studies were performed at two actual scrap iron and metal recycling facilities in order to evaluate the extent of heavy metal migration into subsoil and groundwater caused by more than 25 years of handling scrap directly on the ground without any measures to prevent leaching. Surface soil...... samples, called `scrap dirt', representing the different activities on the two recycling facilities, all showed very high concentrations of lead (Pb), copper (Cu) and zinc (Zn), high concentrations of cadmium (Cd) , chromium (Cr) and nickel (Ni) and somewhat elevated concentrations of many other metals....... In particular high concentrations were found for Pb at the car-battery salvage locations (13 to 26 g Pb kg±1) and Cu at the cable burning location (22 g Cu kg±1) at one site. The migration of metals below the surface in general (except at the car-battery salvage locations) was very limited even after...

Vapor trap for liquid metal

Energy Technology Data Exchange (ETDEWEB)

Watanabe, T

1968-05-22

In a pipe system which transfers liquid metal, inert gas (cover gas) is packed above the surface of the liquid metal to prevent oxidization of the liquid. If the metal vapor is contained in such cover gas, the circulating system of the cover gas is blocked due to condensation of liquid metal inside the system. The present invention relates to an improvement in vapor trap to remove the metal vapor from the cover gas. The trap consists of a cylindrical outer body, an inlet nozzle which is deeply inserted inside the outer body and has a number of holes to inject the cove gas into the body, metal mesh or steel wool which covers the exterior of the nozzle and on which the condensation of the metal gas takes place, and a heater wire hich is wound around the nozzle to prevent condensation of the metal vapor at the inner peripheral side of the mesh.

1/f noise in metallic and semiconducting carbon nanotubes

Science.gov (United States)

Reza, Shahed; Huynh, Quyen T.; Bosman, Gijs; Sippel-Oakley, Jennifer; Rinzler, Andrew G.

2006-11-01

The charge transport and noise properties of three terminal, gated devices containing multiple single-wall metallic and semiconducting carbon nanotubes were measured at room temperature. Applying a high voltage pulsed bias at the drain terminal the metallic tubes were ablated sequentially, enabling the separation of measured conductance and 1/f noise into metallic and semiconducting nanotube contributions. The relative low frequency excess noise of the metallic tubes was observed to be two orders of magnitude lower than that of the semiconductor tubes.

Usefulness of metal artifact reduction with WARP technique at 1.5 and 3T MRI in imaging metal-on-metal hip resurfacings

Energy Technology Data Exchange (ETDEWEB)

Lazik, Andrea; Lauenstein, Thomas C.; Theysohn, Jens M. [University Hospital Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Landgraeber, Stefan; Schulte, Patrick [University Hospital Essen, Department of Orthopedics, Essen (Germany); Kraff, Oliver [University of Duisburg-Essen, Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany)

2015-03-25

To evaluate the usefulness of the metal artifact reduction technique ''WARP'' in the assessment of metal-on-metal hip resurfacings at 1.5 and 3T in the context of image quality and imaging speed. Nineteen patients (25 hip resurfacings) were randomized for 1.5 and 3T MRI, both including T1 and T2 turbo spin-echo as well as turbo inversion recovery magnitude sequences with and without view angle tilting and high bandwidth. Additional 3T sequences were acquired with a reduced number of averages and using the parallel acquisition technique for accelerating imaging speed. Artifact size (diameter, area), image quality (5-point scale) and delineation of anatomical structures were compared among the techniques, sequences and field strengths using the Wilcoxon sign-rank and paired t-test with Bonferroni correction. At both field strengths, WARP showed significant superiority over standard sequences regarding image quality, artifact size and delineation of anatomical structures. At 3T, artifacts were larger compared to 1.5T without affecting diagnostic quality, and scanning time could be reduced by up to 64 % without quality degradation. WARP proved useful in imaging metal-on-metal hip resurfacings at 1.5T as well as 3T with better image quality surrounding the implants. At 3T imaging could be considerably accelerated without losing diagnostic quality. (orig.)

Usefulness of metal artifact reduction with WARP technique at 1.5 and 3T MRI in imaging metal-on-metal hip resurfacings

International Nuclear Information System (INIS)

Lazik, Andrea; Lauenstein, Thomas C.; Theysohn, Jens M.; Landgraeber, Stefan; Schulte, Patrick; Kraff, Oliver

2015-01-01

To evaluate the usefulness of the metal artifact reduction technique ''WARP'' in the assessment of metal-on-metal hip resurfacings at 1.5 and 3T in the context of image quality and imaging speed. Nineteen patients (25 hip resurfacings) were randomized for 1.5 and 3T MRI, both including T1 and T2 turbo spin-echo as well as turbo inversion recovery magnitude sequences with and without view angle tilting and high bandwidth. Additional 3T sequences were acquired with a reduced number of averages and using the parallel acquisition technique for accelerating imaging speed. Artifact size (diameter, area), image quality (5-point scale) and delineation of anatomical structures were compared among the techniques, sequences and field strengths using the Wilcoxon sign-rank and paired t-test with Bonferroni correction. At both field strengths, WARP showed significant superiority over standard sequences regarding image quality, artifact size and delineation of anatomical structures. At 3T, artifacts were larger compared to 1.5T without affecting diagnostic quality, and scanning time could be reduced by up to 64 % without quality degradation. WARP proved useful in imaging metal-on-metal hip resurfacings at 1.5T as well as 3T with better image quality surrounding the implants. At 3T imaging could be considerably accelerated without losing diagnostic quality. (orig.)

Half-metallic properties of the (1 1 0) surface of alkali earth metal monosilicides in the zinc blende phase

International Nuclear Information System (INIS)

Bialek, B; Lee, J I

2011-01-01

An all electron ab initio method was employed to study the electronic and magnetic properties of the (1 1 0) surface of alkaline-earth metal silicides: CaSi, SrSi and BaSi, in the zinc blende structure. The three surfaces are found to conserve the half-metallic properties of their bulk structures with a wide semiconducting energy gap in the spin-up channel. Half-metallic energy gap at the surfaces is small. In the CaSi surface it is of the order of k B T, which indicates that in the CaSi (1 1 0) a transition to a metallic state is possible due to temperature fluctuations. At the same time, the CaSi surface exhibits the strongest magnetic properties with 0.91 μ B magnetic moment on the Si atom in the topmost layer and 0.21 μ B magnetic moment on the Ca atom. In each of the three surfaces we observe a reduction of magnetic moments on the atoms in the subsurface layer and the enhancement of the magnetic moment on the atoms in the topmost layer, as compared with the properties of atoms in the bulk. An analysis of the calculated total and atom projected densities of states leads to a conclusion that the surface effects in the structures are short-range phenomena

Antimicrobial activity of transition metal acid MoO3 prevents microbial growth on material surfaces

International Nuclear Information System (INIS)

Zollfrank, Cordt; Gutbrod, Kai; Wechsler, Peter; Guggenbichler, Josef Peter

2012-01-01

Serious infectious complications of patients in healthcare settings are often transmitted by materials and devices colonised by microorganisms (nosocomial infections). Current strategies to generate material surfaces with an antimicrobial activity suffer from the consumption of the antimicrobial agent and emerging multidrug-resistant pathogens amongst others. Consequently, materials surfaces exhibiting a permanent antimicrobial activity without the risk of generating resistant microorganisms are desirable. This publication reports on the extraordinary efficient antimicrobial properties of transition metal acids such as molybdic acid (H 2 MoO 4 ), which is based on molybdenum trioxide (MoO 3 ). The modification of various materials (e.g. polymers, metals) with MoO 3 particles or sol–gel derived coatings showed that the modified materials surfaces were practically free of microorganisms six hours after contamination with infectious agents. The antimicrobial activity is based on the formation of an acidic surface deteriorating cell growth and proliferation. The application of transition metal acids as antimicrobial surface agents is an innovative approach to prevent the dissemination of microorganisms in healthcare units and public environments. Highlights: ► The presented modifications of materials surfaces with MoO 3 are non-cytotoxic and decrease biofilm growth and bacteria transmission. ► The material is insensitive towards emerging resistances of bacteria. ► Strong potential to reduce spreading of infectious agents on inanimate surfaces.

The Importance of Preventive Feedback: Inference from Observations of the Stellar Masses and Metallicities of Milky Way Dwarf Galaxies

Energy Technology Data Exchange (ETDEWEB)

Lu, Yu; Benson, Andrew; Wetzel, Andrew; Tonnesen, Stephanie [The Observatories, The Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Mao, Yao-Yuan [Department of Physics and Astronomy and the Pittsburgh Particle Physics, Astrophysics and Cosmology Center (PITT PACC), University of Pittsburgh, Pittsburgh, PA 15260 (United States); Peter, Annika H. G. [CCAPP and Department of Physics, The Ohio State University, 191 W. Woodruff Avenue, Columbus, OH 43210 (United States); Boylan-Kolchin, Michael [Department of Astronomy, The University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205 (United States); Wechsler, Risa H. [Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics, Stanford University, Stanford, CA 94305 (United States)

2017-09-01

Dwarf galaxies are known to have remarkably low star formation efficiency due to strong feedback. Adopting the dwarf galaxies of the Milky Way (MW) as a laboratory, we explore a flexible semi-analytic galaxy formation model to understand how the feedback processes shape the satellite galaxies of the MW. Using Markov Chain Monte Carlo, we exhaustively search a large parameter space of the model and rigorously show that the general wisdom of strong outflows as the primary feedback mechanism cannot simultaneously explain the stellar mass function and the mass–metallicity relation of the MW satellites. An extended model that assumes that a fraction of baryons is prevented from collapsing into low-mass halos in the first place can be accurately constrained to simultaneously reproduce those observations. The inference suggests that two different physical mechanisms are needed to explain the two different data sets. In particular, moderate outflows with weak halo mass dependence are needed to explain the mass–metallicity relation, and prevention of baryons falling into shallow gravitational potentials of low-mass halos (e.g., “pre-heating”) is needed to explain the low stellar mass fraction for a given subhalo mass.

Heat transfer enhancement for spent nuclear fuel assembly disposal packages using metallic void fillers: A prevention technique for solidification shrinkage-induced interfacial gaps

Energy Technology Data Exchange (ETDEWEB)

Park, Yongsoo, E-mail: yspark@alum.mit.edu; McKrell, Thomas J.; Driscoll, Michael J.

2017-06-15

This study considers replacing the externally accessible void spaces inside a disposal package containing a spent nuclear fuel assembly (SNFA) with high heat conducting metal to increase the effective thermal conductivity of the package and simplify the heat transfer mechanism inside the package by reducing it to a conduction dominant problem. The focus of the study is on preventing the gaps adjacent to the walls of the package components, produced by solidification shrinkage of poured liquid metal. We approached the problem by providing a temporary coating layer on the components to avoid direct build-up of thick metal oxides on their surface to promote metallic bonding at the interfaces under a non-inert environment. Laboratory scale experiments without SNFA were performed with Zn coated low carbon steel canisters and Zamak-3 void filler under two different filling temperature conditions – below and above the melting point of Zn (designated BMP and AMP respectively). Gap formation was successfully prevented in both cases while we confirmed an open gap in a control experiment, which used an uncoated canister. Minor growth of Al-Fe intermetallic phases was observed at the canister/filler interface of the sample produced under the BMP condition while their growth was significant and showed irregularly distributed morphology in the sample produced under the AMP condition, which has a potential to mitigate excessive residual stresses caused by shrinkage prevention. A procedure for the full-scale application was specified based on the results. - Highlights: •A void filling technique is introduced to enhance SNFA package heat transfer. •The technique is demonstrated via experiments using the Fe-Al-Zn system. •A procedure for the full scale application is proposed based on the results.

Alternative Fabrication of Recycling Fast Reactor Metal Fuel

International Nuclear Information System (INIS)

Kim, Ki-Hwan; Kim, Jong Hwan; Song, Hoon; Kim, Hyung-Tae; Lee, Chan-Bock

2015-01-01

Metal fuels such as U-Zr/U-Pu-Zr alloys have been considered as a nuclear fuel for a sodium-cooled fast reactor (SFR) related to the closed fuel cycle for managing minor actinides and reducing a high radioactivity levels since the 1980s. In order to develop innovative fabrication method of metal fuel for preventing the evaporation of volatile elements such as Am, modified casting under inert atmosphere has been applied for metal fuel slugs for SFR. Alternative fabrication method of fuel slugs has been introduced to develop an improved fabrication process of metal fuel for preventing the evaporation of volatile elements. In this study, metal fuel slugs for SFR have been fabricated by modified casting method, and characterized to evaluate the feasibility of the alternative fabrication method. In order to prevent evaporation of volatile elements such as Am and improve quality of fuel slugs, alternative fabrication methods of metal fuel slugs have been studied in KAERI. U-10Zr-5Mn fuel slug containing volatile surrogate element Mn was soundly cast by modified injection casting under modest pressure. Evaporation of Mn during alternative casting could not be detected by chemical analysis. Mn element was most recovered with prevention of evaporation by alternative casting. Modified injection casting has been selected as an alternative fabrication method in KAERI, considering evaporation prevention, and proven benefits of high productivity, high yield, and good remote control

Stormwater Pollution Prevention Plan for the TA-03-38 Metals Fabrication Shop, Los Alamos National Laboratory, Revision 3, January 2018

Energy Technology Data Exchange (ETDEWEB)

Burgin, Jillian Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2018-02-01

This Storm Water Pollution Prevention Plan (SWPPP) was developed in accordance with the provisions of the Clean Water Act (33 U.S.C. §§1251 et seq., as amended), and the Multi-Sector General Permit for Storm Water Discharges Associated with Industrial Activity (U.S. EPA, June 2015) issued by the U.S. Environmental Protection Agency (EPA) for the National Pollutant Discharge Elimination System (NPDES) and using the industry specific permit requirements for Sector AA-Fabricated Metal Products as a guide. This SWPPP applies to discharges of stormwater from the operational areas of the TA-03-38 Metals Fabrication Shop at Los Alamos National Laboratory. Los Alamos National Laboratory (also referred to as LANL or the “Laboratory”) is owned by the Department of Energy (DOE), and is operated by Los Alamos National Security, LLC (LANS). Throughout this document, the term “facility” refers to the TA-03-38 Metals Fabrication Shop and associated areas. The current permit expires at midnight on June 4, 2020.

Stabilization of heavy metals in Tehran agricultural land

International Nuclear Information System (INIS)

Torabian, A.; Sadeghi, Sh.

2001-01-01

In order to prevent contamination of heavy metals accumulation in soil, plant, and ground water, several methods of prevention are studied, and tested worldwide. One of the method which has not been studied and applied in Iran is stabilization of heavy metals in soil by using clay minerals. Clay minerals due to hydration properties can adsorb organic and inorganic substances. Two clay minerals were used in this research: Bentonite with chemical structure of 2 to 1 (Two layers of silica and one layer of Aluminium) with CEC equal to 85 m eq/100 grams and Kao line with chemical structure of one to one (one layer silica and one layer Aluminum) and CEC=3 m eq/100 grams of soil. The physical and chemical properties of these two kinds of clays were different. Stabilization of heavy metals with different percentages of these two clays (7%, 15%, 22%) with different p H (4,7,8,11.5) were studied. The results indicate that with increasing of stabilizing agent at p H=7.8 and greater, stabilization of heavy metals increased significantly. The results also indicate the stabilization of heavy metals decreased rapidly at p H 4 and lower. The results of this study agree with the work of pervious researchers

Synthesis of metal-metal oxide catalysts and electrocatalysts using a metal cation adsorption/reduction and adatom replacement by more noble ones

Science.gov (United States)

Adzic, Radoslav; Vukmirovic, Miomir; Sasaki, Kotaro

2010-04-27

The invention relates to platinum-metal oxide composite particles and their use as electrocatalysts in oxygen-reducing cathodes and fuel cells. The invention particularly relates to methods for preventing the oxidation of the platinum electrocatalyst in the cathodes of fuel cells by use of these platinum-metal oxide composite particles. The invention additionally relates to methods for producing electrical energy by supplying such a fuel cell with an oxidant, such as oxygen, and a fuel source, such as hydrogen. The invention also relates to methods of making the metal-metal oxide composites.

Metal Inhibition of Growth and Manganese Oxidation in Pseudomonas putida GB-1

Science.gov (United States)

Pena, J.; Sposito, G.

2009-12-01

Biogenic manganese oxides (MnO2) are ubiquitous nanoparticulate minerals that contribute to the adsorption of nutrient and toxicant metals, the oxidative degradation of various organic compounds, and the respiration of metal-reducing bacteria in aquatic and terrestrial environments. The formation of these minerals is catalyzed by a diverse and widely-distributed group of bacteria and fungi, often through the enzymatic oxidation of aqueous Mn(II) to Mn(IV). In metal-impacted ecosystems, toxicant metals may alter the viability and metabolic activity of Mn-oxidizing organisms, thereby limiting the conditions under which biogenic MnO2 can form and diminishing their potential as adsorbent materials. Pseudomonas putida GB-1 (P. putida GB-1) is a model Mn-oxidizing laboratory culture representative of freshwater and soil biofilm-forming bacteria. Manganese oxidation in P. putida GB-1 occurs via two single-electron-transfer reactions, involving a multicopper oxidase enzyme found on the bacterial outer membrane surface. Near the onset of the stationary phase of growth, dark brown MnO2 particles are deposited in a matrix of bacterial cells and extracellular polymeric substances, thus forming heterogeneous biomineral assemblages. In this study, we assessed the influence of various transition metals on microbial growth and manganese oxidation capacity in a P. putida GB-1 culture propagated in a nutrient-rich growth medium. The concentration-response behavior of actively growing P. putida GB-1 cells was investigated for Fe, Co, Ni, Cu and Zn at pH ≈ 6 in the presence and absence of 1 mM Mn. Toxicity parameters such as EC0, EC50 and Hillslope, and EC100 were obtained from the sigmoidal concentration-response curves. The extent of MnO2 formation in the presence of the various metal cations was documented 24, 50, 74 and 104 h after the metal-amended medium was inoculated. Toxicity values were compared to twelve physicochemical properties of the metals tested. Significant

Effect of carbon ion implantation on the tribology of metal-on-metal bearings for artificial joints

Directory of Open Access Journals (Sweden)

Koseki H

2017-05-01

Full Text Available Hironobu Koseki,1 Masato Tomita,2 Akihiko Yonekura,2 Takashi Higuchi,1 Sinya Sunagawa,2 Koumei Baba,3,4 Makoto Osaki2 1Department of Locomotive Rehabilitation Science, Unit of Rehabilitation Sciences, 2Department of Orthopedic Surgery, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto, Nagasaki, Japan; 3Industrial Technology Center of Nagasaki, Ikeda, Omura, Nagasaki, Japan; 4Affiliated Division, Nagasaki University School of Engineering, Bunkyo, Nagasaki, Japan Abstract: Metal-on-metal (MoM bearings have become popular due to a major advantage over metal-on-polymer bearings for total hip arthroplasty in that the larger femoral head and hydrodynamic lubrication of the former reduce the rate of wear. However, concerns remain regarding adverse reactions to metal debris including metallosis caused by metal wear generated at the taper-head interface and another modular junction. Our group has hypothesized that carbon ion implantation (CII may improve metal wear properties. The purpose of this study was to investigate the wear properties and friction coefficients of CII surfaces with an aim to ultimately apply these surfaces to MoM bearings in artificial joints. CII was applied to cobalt-chromium-molybdenum (Co-Cr-Mo alloy substrates by plasma source ion implantation. The substrates were characterized using scanning electron microscopy and a 3D measuring laser microscope. Sliding contact tests were performed with a simple geometry pin-on-plate wear tester at a load of 2.5 N, a calculated contact pressure of 38.5 MPa (max: 57.8 MPa, a reciprocating velocity of 30 mm/s, a stroke length of 60 mm, and a reciprocating cycle count of 172,800 cycles. The surfaces of the CII substrates were generally featureless with a smooth surface topography at the same level as untreated Co-Cr-Mo alloy. Compared to the untreated Co-Cr-Mo alloy, the CII-treated bearings had lower friction coefficients, higher resistance to catastrophic damage, and

Ionic Transport Through Metal-Rich Organic Coatings

Science.gov (United States)

2016-08-19

organic paints, inert metallic layers, and protective oxide layers. 2 Although coatings have been commercially used for many years, the design of new...pigments found in chromates protect the substrate by passivating the metallic surface with an oxide layer. Sacrificial coatings prevent the self...surface, eliminating the components needed for a cathodic reaction to occur. Additionally, organic barrier coatings are protective by preventing

Evaluation report(1): on design criteria for KALIMER metal fuel

International Nuclear Information System (INIS)

Hwang, Woan; Lee, Byoung Oon; Kim, Young Il

2001-04-01

Fuel rods, assembly ducts and their components in KALIMER should be designed to maintain the integrities and to assure their reliable in-reactor performances under the steady state and operational transient conditions which are included in design basis category. And the fuel system must be designed with enough engineering margin to minimize and prevent the failures under ab-normal operational condition, like an accident.In this report, some design limits and the criteria for the fuel assembly ducts for KALIMER are driven by evaluating the irradiation data of metallic fuel based on experimental data from ANL in USA, CRIEPI in Japan and RIAR in Russia

Evaluation report(1): on design criteria for KALIMER metal fuel

Energy Technology Data Exchange (ETDEWEB)

Hwang, Woan; Lee, Byoung Oon; Kim, Young Il

2001-04-01

Fuel rods, assembly ducts and their components in KALIMER should be designed to maintain the integrities and to assure their reliable in-reactor performances under the steady state and operational transient conditions which are included in design basis category. And the fuel system must be designed with enough engineering margin to minimize and prevent the failures under ab-normal operational condition, like an accident.In this report, some design limits and the criteria for the fuel assembly ducts for KALIMER are driven by evaluating the irradiation data of metallic fuel based on experimental data from ANL in USA, CRIEPI in Japan and RIAR in Russia.

Preventing microvascular complications in type 1 diabetes mellitus

OpenAIRE

Viswanathan, Vijay

2015-01-01

Patients with complications of diabetes such as retinopathy, nephropathy, and cardiovascular complications have increased hospital stay with greater economic burden. Prevention of complications should be started before the onset of type 1 diabetes mellitus (T1DM) by working on risk factors and thereafter by intervention upon confirmatory diagnosis which can prevent further damage to β-cells. The actual risk of getting microvascular complications like microalbuminuria and retinopathy progressi...

Heavy metals in our foodstuffs

Energy Technology Data Exchange (ETDEWEB)

1983-11-01

The special group ''chemistry of food and forensic chemistry'' of the Association of German Analytical Chemists in Munich in 1983 issued a statement on that subject. The publication points out how heavy metals (examples: lead, cadmium and mercury) make their way into the foodstuffs, how many heavy metals are contained in our foodstuffs, which heavy metals are indispensable minerals and which aren't, and which heavy metals are ingested with food. It concludes by discussing how heavy metal contamination of our food can be prevented.

Alkali metal for ultraviolet band-pass filter

Science.gov (United States)

Mardesich, Nick (Inventor); Fraschetti, George A. (Inventor); Mccann, Timothy A. (Inventor); Mayall, Sherwood D. (Inventor); Dunn, Donald E. (Inventor); Trauger, John T. (Inventor)

1993-01-01

An alkali metal filter having a layer of metallic bismuth deposited onto the alkali metal is provided. The metallic bismuth acts to stabilize the surface of the alkali metal to prevent substantial surface migration from occurring on the alkali metal, which may degrade optical characteristics of the filter. To this end, a layer of metallic bismuth is deposited by vapor deposition over the alkali metal to a depth of approximately 5 to 10 A. A complete alkali metal filter is described along with a method for fabricating the alkali metal filter.

Type 1 diabetes: New horizons in prediction and prevention.

Science.gov (United States)

Razack, Natasha N; Wherrett, Diane K

2005-01-01

Significant advances have been made in our understanding of the pathogenesis of type 1 diabetes and our ability to predict risk for the condition. This knowledge is being used to develop new and innovative strategies to prevent type 1 diabetes or to prevent further destruction of beta cells in those who are newly diagnosed. Several multicentre studies are underway investigating the natural history of the disease, the genetics behind the disease and ways to stop the autoimmune reaction against beta cells (Type 1 Diabetes TrialNet, Type 1 Diabetes Genetics Consortium and the Trial to Reduce Diabetes in the Genetically at Risk [TRIGR] Study Group). The stage is set to find an agent or strategy to prevent type 1 diabetes or to preserve the residual beta cell mass in new-onset patients.

Potential for energy conservaton in the metal forming industries. Progress report, July 1, 1978-August 15, 1979

Energy Technology Data Exchange (ETDEWEB)

Avitzur, B.; Beidleman, C.R.; Smackey, B.M.

1979-08-01

Reduced energy consumption and improved product attributes are realizable benefits that are achievable through the adoption of optimal metal forming techniques. With the meteoric rise in energy costs, certain segments of the metal forming industries have accelerated their efforts in switching from energy intensive manufacturing techniques, e.g., casting, to metal forming, and, furthermore, from hot forming and machined components to cold forming, notably the automotive industry. The first year results of a two year study that will identify and document potential energy and cost savings associated with the adoption of low energy consumption techniques are presented. When compared with techniques requiring energy for hot forming, heat treatments, and excess or scrap material, the utilizaton of alternative metal forming processes offer considerable promise for energy savings. Descriptions of savings achieved by a combination of analytical methods and imaginative new processes are provided in the form of specific industrial case studies. The elimination of defects through the use of an analytical criteria for the prevention of the central burst is presented. Such available criteria for central burst serve as a justification for the desirability to develop criteria for the prevention of fishskin and other defects. Other savings which may be possible through the development of new technologies are included in an Appendix entitled: Recent Developments in Wire Making. One specific new process, Continuous Hydrostatic Extrusion, has been developed at Western Electric and is described in detail.

Zn(II)- and Cu(II)-induced non-fibrillar aggregates of amyloid-beta (1-42) peptide are transformed to amyloid fibrils, both spontaneously and under the influence of metal chelators.

Science.gov (United States)

Tõugu, Vello; Karafin, Ann; Zovo, Kairit; Chung, Roger S; Howells, Claire; West, Adrian K; Palumaa, Peep

2009-09-01

Aggregation of amyloid-beta (Abeta) peptides is a central phenomenon in Alzheimer's disease. Zn(II) and Cu(II) have profound effects on Abeta aggregation; however, their impact on amyloidogenesis is unclear. Here we show that Zn(II) and Cu(II) inhibit Abeta(42) fibrillization and initiate formation of non-fibrillar Abeta(42) aggregates, and that the inhibitory effect of Zn(II) (IC(50) = 1.8 micromol/L) is three times stronger than that of Cu(II). Medium and high-affinity metal chelators including metallothioneins prevented metal-induced Abeta(42) aggregation. Moreover, their addition to preformed aggregates initiated fast Abeta(42) fibrillization. Upon prolonged incubation the metal-induced aggregates also transformed spontaneously into fibrils, that appear to represent the most stable state of Abeta(42). H13A and H14A mutations in Abeta(42) reduced the inhibitory effect of metal ions, whereas an H6A mutation had no significant impact. We suggest that metal binding by H13 and H14 prevents the formation of a cross-beta core structure within region 10-23 of the amyloid fibril. Cu(II)-Abeta(42) aggregates were neurotoxic to neurons in vitro only in the presence of ascorbate, whereas monomers and Zn(II)-Abeta(42) aggregates were non-toxic. Disturbed metal homeostasis in the vicinity of zinc-enriched neurons might pre-dispose formation of metal-induced Abeta aggregates, subsequent fibrillization of which can lead to amyloid formation. The molecular background underlying metal-chelating therapies for Alzheimer's disease is discussed in this light.

Metal Contacts to Gallium Arsenide.

Science.gov (United States)

Ren, Fan

1991-07-01

While various high performance devices fabricated from the gallium arsenide (GaAs) and related materials have generated considerable interest, metallization are fundamental components to all semiconductor devices and integrated circuits. The essential roles of metallization systems are providing the desired electrical paths between the active region of the semiconductor and the external circuits through the metal interconnections and contacts. In this work, in-situ clean of native oxide, high temperature n-type, low temperature n-type and low temperature p-type ohmic metal systems have been studied. Argon ion mill was used to remove the native oxide prior to metal deposition. For high temperature process n-type GaAs ohmic contacts, Tungsten (W) and Tungsten Silicide (WSi) were used with an epitaxial grown graded Indium Gallium Arsenide (InGaAs) layer (0.2 eV) on GaAs. In addition, refractory metals, Molybdenum (Mo), was incorporated in the Gold-Germanium (AuGe) based on n-type GaAs ohmic contacts to replace conventional silver as barrier to prevent the reaction between ohmic metal and chlorine based plasma as well as the ohmic metallization intermixing which degrades the device performance. Finally, Indium/Gold-Beryllium (In/Au-Be) alloy has been developed as an ohmic contact for p-type GaAs to reduce the contact resistance. The Fermi-level pinning of GaAs has been dominated by the surface states. The Schottky barrier height of metal contacts are about 0.8 V regardless of the metal systems. By using p-n junction approach, barrier height of pulsed C-doped layers was achieved as high as 1.4 V. Arsenic implantation into GaAs method was also used to enhance the barrier height of 1.6 V.

Metal assessment in urban park soils in Sao Paulo 1. Ibirapuera Park

International Nuclear Information System (INIS)

Figueiredo, Ana Maria G.; Camargo, Sonia P.; Pavese, Arthur C.; Gumiero, Felipe C.; Enzweiler, Jacinta; Sigolo, Joel B.

2007-01-01

In the last years urban soils received increasing attention by scientists, leading to studies focused on their description and investigation all over the world, due to the increasing metal pollution derived from incinerators, industrial waste, atmospheric deposition of dust and aerosols, and other activities. Metal contamination in Sao Paulo public parks is an important environmental question and there is little information on this subject. As part of a project which aims metal assessment in urban park soils from Sao Paulo, in the present paper the concentration of the elements As, Ba, Cr, Pb, Sb and Zn were determined in surface soil samples (0-5 cm) from Ibirapuera park of Sao Paulo. Ibirapuera park is one of the biggest and most visited parks of the city of Sao Paulo, receiving during the weekends more than 400,000 visitors. Instrumental Neutron Activation Analysis (INAA) and X-ray Fluorescence (FRX) were used for metal analysis. Preliminary results showed concentration levels of the analyzed elements higher than the values considered as reference values for soils in Sao Paulo, according to the Environmental Protection Agency of the State of Sao Paulo (CETESB). For As, Ba, Cr and Sb, in some samples the concentrations were even higher than the Prevention values reported by CETESB. The high concentrations of the elements As, Ba, Cr, Pb, Sb and Zn in the Ibirapuera park top soils suggest an anthropogenic source and indicate a potential damage to soil quality. (author)

The 1s x-ray absorption pre-edge structures in transition metal oxides

NARCIS (Netherlands)

de Groot, Frank|info:eu-repo/dai/nl/08747610X; Vanko, Gyoergy; Glatzel, Pieter

2009-01-01

We develop a general procedure to analyse the pre-edges in 1s x-ray absorption near edge structure (XANES) of transition metal oxides and coordination complexes. Transition metal coordination complexes can be described from a local model with one metal ion. The 1s 3d quadrupole transitions are

Pumping liquid metal at high temperatures up to 1,673 kelvin

Science.gov (United States)

Amy, C.; Budenstein, D.; Bagepalli, M.; England, D.; Deangelis, F.; Wilk, G.; Jarrett, C.; Kelsall, C.; Hirschey, J.; Wen, H.; Chavan, A.; Gilleland, B.; Yuan, C.; Chueh, W. C.; Sandhage, K. H.; Kawajiri, Y.; Henry, A.

2017-10-01

Heat is fundamental to power generation and many industrial processes, and is most useful at high temperatures because it can be converted more efficiently to other types of energy. However, efficient transportation, storage and conversion of heat at extreme temperatures (more than about 1,300 kelvin) is impractical for many applications. Liquid metals can be very effective media for transferring heat at high temperatures, but liquid-metal pumping has been limited by the corrosion of metal infrastructures. Here we demonstrate a ceramic, mechanical pump that can be used to continuously circulate liquid tin at temperatures of around 1,473-1,673 kelvin. Our approach to liquid-metal pumping is enabled by the use of ceramics for the mechanical and sealing components, but owing to the brittle nature of ceramics their use requires careful engineering. Our set-up enables effective heat transfer using a liquid at previously unattainable temperatures, and could be used for thermal storage and transport, electric power production, and chemical or materials processing.

Effects of 12 metal ions on iron regulatory protein 1 (IRP-1) and hypoxia-inducible factor-1 alpha (HIF-1α) and HIF-regulated genes

International Nuclear Information System (INIS)

Li Qin; Chen Haobin; Huang Xi; Costa, Max

2006-01-01

Several metal ions that are carcinogenic affect cellular iron homeostasis by competing with iron transporters or iron-regulated enzymes. Some metal ions can mimic a hypoxia response in cells under normal oxygen tension, and induce expression of HIF-1α-regulated genes. This study investigated whether 12 metal ions altered iron homeostasis in human lung carcinoma A549 cells as measured by an activation of IRP-1 and ferritin level. We also studied hypoxia signaling by measuring HIF-1α protein levels, hypoxia response element (HRE)-driven luciferase reporter activity, and Cap43 protein level (an HIF-1α responsive gene). Our results show the following: (i) Ni(II), Co(II), V(V), Mn(II), and to a lesser extent As(III) and Cu(II) activated the binding of IRP-1 to IRE after 24 h, while the other metal ions had no effect; (ii) 10 of 12 metal ions induced HIF-1α protein but to strikingly different degrees. Two of these metal ions, Al(III) and Cd(II), did not induce HIF-1α protein; however, as indicated below, only Ni(II), Co (II), and to lesser extent Mn(II) and V(V) activated HIF-1α-dependent transcription. The combined effects of both [Ni(II) + As(III)] and [Ni(II) + Cr(VI)] on HIF-1α protein were synergistic; (iii) Addition of Fe(II) with Ni(II), Co(II), and Cr(VI) attenuated the induction of HIF-1α after 4 h treatment; (iv) Ni(II), Co(II), and Mn(II) significantly decrease ferritin level after 24 h exposure; (v) Ni(II), Co(II), V(V), and Mn(II) activated HRE reporter gene after 20 h treatment; (vi) Ni(II), Co(II), V(V), and Mn(II) increased the HIF-1-dependent Cap43 protein level after 24 h treatment. In conclusion, only Ni (II), Co (II), and to a lesser extent Mn(II) and V(V) significantly stabilized HIF-1α protein, activated IRP, decreased the levels of ferritin, induced the transcription of HIF-dependent reporter, and increased the expression of Cap43 protein levels (HIF-dependent gene). The mechanism for the significant stabilization and elevation of HIF-1�

THE BIMODAL METALLICITY DISTRIBUTION OF THE COOL CIRCUMGALACTIC MEDIUM AT z {approx}< 1

Energy Technology Data Exchange (ETDEWEB)

Lehner, N.; Howk, J. C. [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); Tripp, T. M. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Tumlinson, J.; Thom, C.; Fox, A. J. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Prochaska, J. X.; Werk, J. K. [UCO/Lick Observatory, University of California, Santa Cruz, CA (United States); O' Meara, J. M. [Department of Physics, Saint Michael' s College, Vermont, One Winooski Park, Colchester, VT 05439 (United States); Ribaudo, J. [Department of Physics, Utica College, 1600 Burrstone Road, Utica, New York 13502 (United States)

2013-06-20

We assess the metal content of the cool ({approx}10{sup 4} K) circumgalactic medium (CGM) about galaxies at z {approx}< 1 using an H I-selected sample of 28 Lyman limit systems (LLS; defined here as absorbers with 16.2 {approx}< log N{sub H{sub I}} {approx}< 18.5) observed in absorption against background QSOs by the Cosmic Origins Spectrograph on board the Hubble Space Telescope. The N{sub H{sub I}} selection avoids metallicity biases inherent in many previous studies of the low-redshift CGM. We compare the column densities of weakly ionized metal species (e.g., O II, Si II, Mg II) to N{sub H{sub I}} in the strongest H I component of each absorber. We find that the metallicity distribution of the LLS (and hence the cool CGM) is bimodal with metal-poor and metal-rich branches peaking at [X/H] {approx_equal} -1.6 and -0.3 (or about 2.5% and 50% solar metallicities). The cool CGM probed by these LLS is predominantly ionized. The metal-rich branch of the population likely traces winds, recycled outflows, and tidally stripped gas; the metal-poor branch has properties consistent with cold accretion streams thought to be a major source of fresh gas for star forming galaxies. Both branches have a nearly equal number of absorbers. Our results thus demonstrate there is a significant mass of previously undiscovered cold metal-poor gas and confirm the presence of metal enriched gas in the CGM of z {approx}< 1 galaxies.

HIV-1 transmission linkage in an HIV-1 prevention clinical trial

Energy Technology Data Exchange (ETDEWEB)

Leitner, Thomas [Los Alamos National Laboratory; Campbell, Mary S [UNIV OF WASHINGTON; Mullins, James I [UNIV OF WASHINGTON; Hughes, James P [UNIV OF WASHINGTON; Wong, Kim G [UNIV OF WASHINGTON; Raugi, Dana N [UNIV OF WASHINGTON; Scrensen, Stefanie [UNIV OF WASHINGTON

2009-01-01

HIV-1 sequencing has been used extensively in epidemiologic and forensic studies to investigate patterns of HIV-1 transmission. However, the criteria for establishing genetic linkage between HIV-1 strains in HIV-1 prevention trials have not been formalized. The Partners in Prevention HSV/HIV Transmission Study (ClinicaITrials.gov NCT00194519) enrolled 3408 HIV-1 serodiscordant heterosexual African couples to determine the efficacy of genital herpes suppression with acyclovir in reducing HIV-1 transmission. The trial analysis required laboratory confirmation of HIV-1 linkage between enrolled partners in couples in which seroconversion occurred. Here we describe the process and results from HIV-1 sequencing studies used to perform transmission linkage determination in this clinical trial. Consensus Sanger sequencing of env (C2-V3-C3) and gag (p17-p24) genes was performed on plasma HIV-1 RNA from both partners within 3 months of seroconversion; env single molecule or pyrosequencing was also performed in some cases. For linkage, we required monophyletic clustering between HIV-1 sequences in the transmitting and seroconverting partners, and developed a Bayesian algorithm using genetic distances to evaluate the posterior probability of linkage of participants sequences. Adjudicators classified transmissions as linked, unlinked, or indeterminate. Among 151 seroconversion events, we found 108 (71.5%) linked, 40 (26.5%) unlinked, and 3 (2.0%) to have indeterminate transmissions. Nine (8.3%) were linked by consensus gag sequencing only and 8 (7.4%) required deep sequencing of env. In this first use of HIV-1 sequencing to establish endpoints in a large clinical trial, more than one-fourth of transmissions were unlinked to the enrolled partner, illustrating the relevance of these methods in the design of future HIV-1 prevention trials in serodiscordant couples. A hierarchy of sequencing techniques, analysis methods, and expert adjudication contributed to the linkage

Effects of electromagnetic shielding cases for semiconductor-type electronic personal dosimeters on preventing electromagnetic interference

International Nuclear Information System (INIS)

Deji, Shizuhiko; Ito, Shigeki; Nishizawa, Kunihide; Saze, Takuya; Mori, Kazuyuki

2005-01-01

Performance of electromagnetic shielding cases for preventing malfunction of semiconductor-type electronic personal dosimeters (SEPDs) caused by high frequency electromagnetic fields emitted from a digital cellular telephone (cell phone) and a card reader of access control system were analyzed. The cases were handcrafted by using cloth of activated carbon fiber, polyester film laminated metal, and two kinds of metal netting. Five kinds of SEPDs put in the cases were exposed to the high frequency electromagnetic fields for 50 sec or 1 min. The cases prevented perfectly the malfunction due to the cell phone. The cases shortened distances required to prevent the malfunction due to the card reader, but did not prevent the malfunction. The electromagnetic immunity level of SEPD inserted in the cases increased from greater than 11.2 to greater than 18.7 times for the cell phone and from 1.1 to greater than 4.3 times for the card reader. The maximum of electromagnetic shielding effectiveness of each case was greater than 18.7 times for the cell phone and greater than 4.3 times for the card reader. (author)

THE BIMODAL METALLICITY DISTRIBUTION OF THE COOL CIRCUMGALACTIC MEDIUM AT z ∼< 1

International Nuclear Information System (INIS)

Lehner, N.; Howk, J. C.; Tripp, T. M.; Tumlinson, J.; Thom, C.; Fox, A. J.; Prochaska, J. X.; Werk, J. K.; O'Meara, J. M.; Ribaudo, J.

2013-01-01

We assess the metal content of the cool (∼10 4 K) circumgalactic medium (CGM) about galaxies at z ∼ H I ∼ H I selection avoids metallicity biases inherent in many previous studies of the low-redshift CGM. We compare the column densities of weakly ionized metal species (e.g., O II, Si II, Mg II) to N H I in the strongest H I component of each absorber. We find that the metallicity distribution of the LLS (and hence the cool CGM) is bimodal with metal-poor and metal-rich branches peaking at [X/H] ≅ –1.6 and –0.3 (or about 2.5% and 50% solar metallicities). The cool CGM probed by these LLS is predominantly ionized. The metal-rich branch of the population likely traces winds, recycled outflows, and tidally stripped gas; the metal-poor branch has properties consistent with cold accretion streams thought to be a major source of fresh gas for star forming galaxies. Both branches have a nearly equal number of absorbers. Our results thus demonstrate there is a significant mass of previously undiscovered cold metal-poor gas and confirm the presence of metal enriched gas in the CGM of z ∼< 1 galaxies.

Chemical principles underpinning the performance of the metal-organic framework HKUST-1.

Science.gov (United States)

Hendon, Christopher H; Walsh, Aron

2015-07-15

A common feature of multi-functional metal-organic frameworks is a metal dimer in the form of a paddlewheel, as found in the structure of Cu 3 ( btc ) 2 (HKUST-1). The HKUST-1 framework demonstrates exceptional gas storage, sensing and separation, catalytic activity and, in recent studies, unprecedented ionic and electrical conductivity. These results are a promising step towards the real-world application of metal-organic materials. In this perspective, we discuss progress in the understanding of the electronic, magnetic and physical properties of HKUST-1, representative of the larger family of Cu···Cu containing metal-organic frameworks. We highlight the chemical interactions that give rise to its favourable properties, and which make this material well suited to a range of technological applications. From this analysis, we postulate key design principles for tailoring novel high-performance hybrid frameworks.

Electron beam welding of the dissimilar Zr-based bulk metallic glass and Ti metal

Energy Technology Data Exchange (ETDEWEB)

Kim, Jonghyun [Department of Material Science, Kumamoto University, Kumamoto 860-8555 (Japan)], E-mail: joindoc@kumamoto-u.ac.jp; Kawamura, Y. [Department of Material Science, Kumamoto University, Kumamoto 860-8555 (Japan)

2007-04-15

We successfully welded 3 mm thick Zr{sub 41}Be{sub 23}Ti{sub 14}Cu{sub 12}Ni{sub 10} bulk metallic glass plate to Ti metal by electron beam welding with a beam irradiated 0.4 mm on the BMG side of the interface. There was no crystallization or defects in the weld because changes in the chemical composition of the weld metal were prevented. Bending showed that the welded sample had a higher strength than the Ti base metal. The interface had a 10 {mu}m thick interdiffusion layer of Zr and Ti.

Processing method of radioactive metal wastes

International Nuclear Information System (INIS)

Uetake, Naoto; Urata, Megumu; Sato, Masao.

1985-01-01

Purpose: To reduce the volume and increase the density of radioactive metal wastes easily while preventing scattering of radioactivity and process them into suitable form to storage and treatment. Method: Metal wastes mainly composed of zirconium are discharged from nuclear power plants or fuel re-processing plants, and these metals such as zirconium and titanium vigorously react with hydrogen and rapidly diffuse as hydrides. Since the hydrides are extremely brittle and can be pulverized easily, they can be volume-reduced. However, since metal hydrides have no ductility, dehydrogenation is applied for the molding fabrication in view of the subsequent storage and processing. The dehydrogenation is easy like the hydrogenation and fine metal pieces can be molded in a small compression device. For the dehydrogenation, a temperature is slightly increased as compared with that in the hydrogenation, pressure is reduced through the vacuum evacuation system and the removed hydrogen is purified for reuse. The upper limit for the temperature of the hydrogenation is 680 0 C in order to prevent the scttering of radioactivity. (Kamimura, M.)

Barley HvHMA1 is a heavy metal pump involved in mobilizing organellar Zn and Cu and plays a role in metal loading into grains

DEFF Research Database (Denmark)

Mikkelsen, Maria Dalgaard; Pedas, Pai; Schiller, Michaela

2012-01-01

Heavy metal transporters belonging to the P1B-ATPase subfamily of P-type ATPases are key players in cellular heavy metal homeostasis. Heavy metal transporters belonging to the P1B-ATPase subfamily of P-type ATPases are key players in cellular heavy metal homeostasis. In this study we investigated...

Principles for prevention of toxic effects from metals

DEFF Research Database (Denmark)

Landrigan, Philip J.; Kotelchuk, David; Grandjean, Philippe

2007-01-01

of the Toxic Effects of Metals Aluminum Antimony Arsenic Barium Beryllium Bismuth Cadmium Chromium Cobalt Copper Gallium and Semiconductor Compounds Germanium Indium Iron Lead Manganese Mercury Molybdenum Nickel Palladium Platinum Selenium Silver Tellurium Thallium Tin Titanium Tungsten Uranium Vanadium Zinc...

Effectiveness of Co intercalation between Graphene and Ir(1 1 1)

Science.gov (United States)

Carlomagno, I.; Drnec, J.; Scaparro, A. M.; Cicia, S.; Mobilio, S.; Felici, R.; Meneghini, C.

2018-04-01

Graphene can be used to avoid the oxidation of metallic films. This work explores the effectiveness of such stabilizing effect on Cobalt (Co) films intercalated between Graphene and Ir(1 1 1). After intercalation at 300 °C, two Co films are exposed to ambient pressure and investigated using Co-K edge X-ray Absorption Near Edge Spectroscopy. The formation of a disordered oxide phase is observed, and associated to the presence of some non-intercalated Co. Further annealing at 500 °C causes the oxide reduction to metallic Co which further intercalates below the Graphene. Once the intercalation is completed, Graphene prevents the Co from oxidation under ambient pressure conditions.

Stress corrosion cracking prevention using solar electricity

International Nuclear Information System (INIS)

Harijan, K.; Uqaaili, M.A; Mirani, M.

2004-01-01

Metallic structures exposed to soil and water naturally experience corrosion due to electrolytic action. These structures are also subjected to sustained tensile stresses. The combined effects of corrosion and stress results stress corrosion cracking (SCC). Removal of either of these i.e. stress or corrosion prevents SCC. The cathodic protection (CP) prevents corrosion, and hence prevents stress corrosion. Solar Photo voltaic (PV) generated electricity can be best external power source for CP systems especially in remote areas. This paper presents CP system using solar PV generated electricity as an external power source for prevention of SCC of metallic structures. The paper also compares CP systems using solar electricity with those of CP systems using conventional electricity. The paper concludes that a solar electricity power system provides a reliable solution for powering CP stations especially in remote areas, enables the placing of CP units in any location, and thus ensures optimal current distribution for the exact protection requirements. The paper also concludes that solar electricity CP systems are well suited for SCC protection of metallic structures especially in remote areas of an energy deficit country like Pakistan. (author)

Noble metals-compatible melter features development Phase 1: Establishing functional and design criteria and design concepts

International Nuclear Information System (INIS)

Elmore, M.R.; Siemens, D.H.; Chapman, C.C.

1996-03-01

Premature failures have occurred in melters at Japan's Tokai Mockup Facility and at the Federal Republic of Germany (FRG) PAMELA plant during processing of feeds with high levels of noble metals. Melter failure was due to the accumulation of an electrically conductive, noble metals-containing precipitates in the glass, that then resulted in short circuiting of the electrodes. A comparison was made of the anticipated Hanford Waste Vitrification Plant (HWVP) feed with the feeds processed in the FRG and Japanese melters. The evaluation showed that comparable levels of noble metals and other potential precipitate-forming components (e.g. Cr/Fe/Ni-spinels) exist in the HWVP feed. As a result, the HWVP project made a decision to modify the present reference melter design to include features to prevent the precipitation and accumulation or otherwise accommodate precipitated phases on a routine basis without loss of production capacity

Pre-exposure prophylaxis for HIV-1 prevention does not diminish the pregnancy prevention effectiveness of hormonal contraception.

Science.gov (United States)

Murnane, Pamela M; Heffron, Renee; Ronald, Allan; Bukusi, Elizabeth A; Donnell, Deborah; Mugo, Nelly R; Were, Edwin; Mujugira, Andrew; Kiarie, James; Celum, Connie; Baeten, Jared M

2014-07-31

For women at risk of HIV-1, effective contraception and effective HIV-1 prevention are global priorities. In a clinical trial of pre-exposure prophylaxis (PrEP) for HIV-1 prevention in HIV-1-serodiscordant couples, we estimated the effectiveness of hormonal contraceptives (oral contraceptive pills, injectable depot medroxyprogesterone acetate, and hormonal implants) for pregnancy prevention relative to no contraception among 1785 HIV-1-uninfected women followed up to 36 months. We compared the effectiveness of each method among women assigned PrEP versus placebo. Contraception was not required for participation, but was offered on-site and was recorded monthly; incident pregnancy was determined by monthly urine testing. For women using no contraception, overall pregnancy incidence was 15.4% per year. Women reporting oral contraceptive use had comparable pregnancy incidence to women using no contraception, and this lack of contraceptive effectiveness was similar for those assigned PrEP and placebo (17.7 and 10.0% incidence per year, respectively; P-value for difference in effect by PrEP use = 0.24). Women reporting injectable contraception had reduced pregnancy incidence compared to those reporting no contraception, which did not differ by arm (PrEP 5.1%, placebo 5.3% per year; P-value for difference = 0.47). Contraceptive effectiveness was highest among women using implants (pregnancy incidence <1% per year in both arms). PrEP had no adverse impact on hormonal contraceptive effectiveness for pregnancy prevention. As seen previously in similar populations, women reporting contraceptive pill use had little protection from pregnancy, possibly due to poor adherence. Injectable or implantable hormonal contraception and PrEP provide effective prevention for pregnancy and HIV-1.

1/f Fluctuations in ion implanted metal semiconductor contacts

International Nuclear Information System (INIS)

Stojanovic, M.; Marjanovic, N.; Radojevic, B.

1998-01-01

Ion implanted Metal-Semiconductor contacts is the most widely used structures in electrical devices. Weather complete devices or some parts are of interest, properties of metal-semiconductor junction strongly influence the quality and external characteristic of electronic devices. That is the reason why special attention is paid to the investigation of factor (noise for example) that could influence given junction. Low frequency 1/f fluctuations (noise) are constantly present in metal-semiconductor junction, so measurement of their level as well as the dependence on factors such as temperature must be taken into account in detailed analysis of electrical characteristics of devices such as contact, nuclear detector with surface barrier etc. In this paper we present the results of low frequency noise level measurements on TiN-Ti-Si structures produced by As + ion implantation. (author)

Preventing microvascular complications in type 1 diabetes mellitus

Science.gov (United States)

Viswanathan, Vijay

2015-01-01

Patients with complications of diabetes such as retinopathy, nephropathy, and cardiovascular complications have increased hospital stay with greater economic burden. Prevention of complications should be started before the onset of type 1 diabetes mellitus (T1DM) by working on risk factors and thereafter by intervention upon confirmatory diagnosis which can prevent further damage to β-cells. The actual risk of getting microvascular complications like microalbuminuria and retinopathy progression starts at glycated hemoglobin (HbA1c) level of 7%. As per the American Diabetes Association, a new pediatric glycemic control target of HbA1c 20 years as compared to patients <10 years of age. Screening of these complications should be done regularly, and appropriate preventive strategies should be followed. Angiotensin converting enzyme inhibitors and angiotensin II receptor blocker reduce progression from microalbuminuria to macroalbuminuria and increase the regression rate to normoalbuminuria. Diabetic microvascular complications can be controlled with tight glycemic therapy, dyslipidemia management and blood pressure control along with renal function monitoring, lifestyle changes, including smoking cessation and low-protein diet. An integrated and personalized care would reduce the risk of development of microvascular complications in T1DM patients. The child with diabetes who receives limited care is more likely to develop long-term complications at an earlier age. Screening for subclinical complications and early interventions with intensive therapy is the need of the hour. PMID:25941647

ULC/ORD-C80.1 : the standard for aboveground non-metallic tanks for fuel oil

Energy Technology Data Exchange (ETDEWEB)

Nikolic, G. [Underwriters' Lab. of Canada, Toronto, ON (Canada)

2001-09-01

requirements was accomplished by the vent pipe directed outside of the test area, and the vaporization of the liquid due to the external fire was released through this vent. The original form of the FRP tank was retained after the testing. The secondary metal containment prevented the product from release in the environment in the case of the molded high-density polyethylene tanks. Other tests must be passed, such as permeability tests, stability tests, and expansion and contraction tests. 1 fig.

Metallic hydrogen research

International Nuclear Information System (INIS)

Burgess, T.J.; Hawke, R.S.

1978-01-01

Theoretical studies predict that molecular hydrogen can be converted to the metallic phase at very high density and pressure. These conditions were achieved by subjecting liquid hydrogen to isentropic compression in a magnetic-flux compression device. Hydrogen became electrically conducting at a density of about 1.06 g/cm 3 and a calculated pressure of about 2 Mbar. In the experimental device, a cylindrical liner, on implosion by high explosive, compresses a magnetic flux which in turn isentropically compresses a hydrogen sample; coaxial conical anvils prevent escape of the sample during compression. One anvil contains a coaxial cable that uses alumina ceramic as an insulator; this probe allows continuous measurement of the electrical conductivity of the hydrogen. A flash x-ray radiograph exposed during the experiment records the location of the sample-tube boundaries and permits calculation of the sample density. The theoretical underpinnings of the metallic transition of hydrogen are briefly summarized, and the experimental apparatus and technique, analytical methods, and results are described. 9 figures

U.S. Department of Energy National Center of Excellence for Metals Recycle

International Nuclear Information System (INIS)

Adams, V.; Bennett, M.; Bishop, L.

1998-05-01

The US Department of Energy (DOE) National Center of Excellence for Metals Recycle has recently been established. The vision of this new program is to develop a DOE culture that promotes pollution prevention by considering the recycle and reuse of metal as the first and primary disposition option and burial as a last option. The Center of Excellence takes the approach that unrestricted release of metal is the first priority because it is the most cost-effective disposition pathway. Where this is not appropriate, restricted release, beneficial reuse, and stockpile of ingots are considered. Current recycling activities include the sale of 40,000 tons of scrap metal from the East Tennessee Technology Park (formerly K-25 Plant) K-770 scrap yard, K-1064 surplus equipment and machinery, 7,000 PCB-contaminated drums, 12,000 tons of metal from the Y-l2 scrap yard, and 1,000 metal pallets. In addition, the Center of Excellence is developing a toolbox for project teams that will contain a number of specific tools to facilitate metals recycle. This Internet-based toolbox will include primers, computer programs, and case studies designed to help sites to perform life cycle analysis, perform ALARA (As Low As is Reasonably Achievable) analysis for radiation exposures, provide pollution prevention information and documentation, and produce independent government estimates. The use of these tools is described for two current activities: disposition of scrap metal in the Y-12 scrapyard, and disposition of PCB-contaminated drums

PROSPECTING IN LATE-TYPE DWARFS: A CALIBRATION OF INFRARED AND VISIBLE SPECTROSCOPIC METALLICITIES OF LATE K AND M DWARFS SPANNING 1.5 dex

Energy Technology Data Exchange (ETDEWEB)

Mann, Andrew W.; Hilton, Eric J. [Institute for Astronomy, University of Hawai' i, 2680 Woodlawn Dr, Honolulu, HI 96822 (United States); Brewer, John M. [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Gaidos, Eric [Department of Geology and Geophysics, University of Hawai' i, 1680 East-West Road, Honolulu, HI 96822 (United States); Lepine, Sebastien [Department of Astrophysics, American Museum of Natural History, New York, NY 10024 (United States)

2013-02-01

Knowledge of late K and M dwarf metallicities can be used to guide planet searches and constrain planet formation models. However, the determination of metallicities of late-type stars is difficult because visible wavelength spectra of their cool atmospheres contain many overlapping absorption lines, preventing the measurement of equivalent widths. We present new methods, and improved calibrations of existing methods, to determine metallicities of late K and M dwarfs from moderate resolution (1300 < R < 2000) visible and infrared spectra. We select a sample of 112 wide binary systems that contain a late-type companion to a solar-type primary star. Our sample includes 62 primary stars with previously published metallicities, as well as 50 stars with metallicities determined from our own observations. We use our sample to empirically determine which features in the spectrum of the companion are best correlated with the metallicity of the primary. We find {approx_equal}120 features in K and M dwarf spectra that are useful for predicting metallicity. We derive metallicity calibrations for different wavelength ranges, and show that it is possible to get metallicities reliable to <0.10 dex using either visible, J-, H-, or K-band spectra. We find that the most accurate metallicities derived from visible spectra requires the use of different calibrations for early-type (K5.5-M2) and late-type (M2-M6) dwarfs. Our calibrations are applicable to dwarfs with metallicities of -1.04 < [Fe/H] <+0.56 and spectral types from K7 to M5. Lastly, we use our sample of wide binaries to test and refine existing calibrations to determine M dwarf metallicities. We find that the {zeta} parameter, which measures the ratio of TiO can CaH bands, is correlated with [Fe/H] for super-solar metallicities, and {zeta} does not always correctly identify metal-poor M dwarfs. We also find that existing calibrations in the K and H bands are quite reliable for stars with [Fe/H] >-0.5, but are less useful

Heavy metal contamination of soil and water in the vicinity of an abandoned e-waste recycling site: implications for dissemination of heavy metals.

Science.gov (United States)

Wu, Qihang; Leung, Jonathan Y S; Geng, Xinhua; Chen, Shejun; Huang, Xuexia; Li, Haiyan; Huang, Zhuying; Zhu, Libin; Chen, Jiahao; Lu, Yayin

2015-02-15

Illegal e-waste recycling activity has caused heavy metal pollution in many developing countries, including China. In recent years, the Chinese government has strengthened enforcement to impede such activity; however, the heavy metals remaining in the abandoned e-waste recycling site can still pose ecological risk. The present study aimed to investigate the concentrations of heavy metals in soil and water in the vicinity of an abandoned e-waste recycling site in Longtang, South China. Results showed that the surface soil of the former burning and acid-leaching sites was still heavily contaminated with Cd (>0.39 mg kg(-1)) and Cu (>1981 mg kg(-1)), which exceeded their respective guideline levels. The concentration of heavy metals generally decreased with depth in both burning site and paddy field, which is related to the elevated pH and reduced TOM along the depth gradient. The pond water was seriously acidified and contaminated with heavy metals, while the well water was slightly contaminated since heavy metals were mostly retained in the surface soil. The use of pond water for irrigation resulted in considerable heavy metal contamination in the paddy soil. Compared with previous studies, the reduced heavy metal concentrations in the surface soil imply that heavy metals were transported to the other areas, such as pond. Therefore, immediate remediation of the contaminated soil and water is necessary to prevent dissemination of heavy metals and potential ecological disaster. Copyright © 2014 Elsevier B.V. All rights reserved.

Preventing microvascular complications in type 1 diabetes mellitus

Directory of Open Access Journals (Sweden)

Vijay Viswanathan

2015-01-01

Full Text Available Patients with complications of diabetes such as retinopathy, nephropathy, and cardiovascular complications have increased hospital stay with greater economic burden. Prevention of complications should be started before the onset of type 1 diabetes mellitus (T1DM by working on risk factors and thereafter by intervention upon confirmatory diagnosis which can prevent further damage to β-cells. The actual risk of getting microvascular complications like microalbuminuria and retinopathy progression starts at glycated hemoglobin (HbA1c level of 7%. As per the American Diabetes Association, a new pediatric glycemic control target of HbA1c 20 years as compared to patients <10 years of age. Screening of these complications should be done regularly, and appropriate preventive strategies should be followed. Angiotensin converting enzyme inhibitors and angiotensin II receptor blocker reduce progression from microalbuminuria to macroalbuminuria and increase the regression rate to normoalbuminuria. Diabetic microvascular complications can be controlled with tight glycemic therapy, dyslipidemia management and blood pressure control along with renal function monitoring, lifestyle changes, including smoking cessation and low-protein diet. An integrated and personalized care would reduce the risk of development of microvascular complications in T1DM patients. The child with diabetes who receives limited care is more likely to develop long-term complications at an earlier age. Screening for subclinical complications and early interventions with intensive therapy is the need of the hour.

Toughness of 2,25Cr-1Mo steel and weld metal

Science.gov (United States)

Acarer, Mustafa; Arici, Gökhan; Acar, Filiz Kumdali; Keskinkilic, Selcuk; Kabakci, Fikret

2017-09-01

2,25Cr-1Mo steel is extensively used at elevated temperature structural applications in fossil fire power plants for steam pipes, nozzle chambers and petrochemical industry for hydrocracking unit due to its excellent creep resistance and good redundant to oxidation. Also they should have acceptable weldability and toughness. The steels are supplied in quenched and tempered condition and their welded components are subjected to post-weld heat treatment (PWHT). Tempering process is carried out at 690-710°C to improve toughness properties. However they are sensitive to reheat cracking and temper embrittlement. To measure temper embrittlement of the steels and their weld metal, temper embrittlement factor and formula (J factor - Watanabe and X formula- Bruscato) are used. Step cooling heat treatment is also applied to determine temper embrittlement. In this study, toughness properties of Cr Mo (W) steels were reviewed. Also transition temperature curves of 2,25Cr-1Mo steel and its weld metal were constructed before and after step cool heat treatment as experimental study. While 2,25Cr-1Mo steel as base metal was supplied, all weld metal samples were produced in Gedik Welding Company. Hardness measurements and microstructure evaluation were also carried out.

Characterization of metallized alumina: properties. [Diamonite P-3142-1, Wesgo Al-500 alumina ceramics

Energy Technology Data Exchange (ETDEWEB)

Swearengen, J.C.; Burchett, O.L., Gieske, J.H.

1976-12-01

The effects of metallizing and brazing on the mechanical properties of Diamonite P-3142-1 and Wesgo A1-500 alumina ceramics were evaluated. The information was required for analytical prediction of the performance of ceramic-to-metal joints formed by the metallize-braze process. Residual stresses and fracture strengths were monitored before and after metallizing treatments; micromechanical modelling and surface acoustic wave experiments were utilized to determine density, thermal expansion and elastic moduli within the metallized region of the ceramics. It was observed that the metallizing elements penetrate the ceramics to a depth of about 005 ..mu..m and measurably modify the properties to a depth of about 300 ..mu..m. The moduli and density are increased approximately five percent within the penetration zone. The thermal expansion coefficients are not modified significantly by metallizing; the warping which occurs during metallizing results from microstructural changes within the ceramics and not differential thermal contraction. Fracture toughness of the Diamonite ceramic is greater than that of the Wesgo, although the metallizing treatments increase the toughness of each. Fracture strength of the Diamonite was degraded on the metallized surface, whereas the strength of the Wesgo was essentially unchanged by metallizing. Macroscopic compressive residual stresses, which exist at the surfaces of the ceramics, do not significantly affect the fracture strengths. The implications of these results for calculations of joint performance are discussed.

Promotion of Preventive Measures in Public Nursery Schools: Lessons From the H1N1 Pandemic.

Science.gov (United States)

Michail, Koralia A; Ioannidou, Christina; Galanis, Petros; Tsoumakas, Kostantinos; Pavlopoulou, Ioanna D

2017-09-01

Nursery schools serve as reservoirs of transmission of infectious diseases, and teachers should be able to implement and monitor hygiene measures to prevent them. The aim of the present study was to assess the compliance of nursery school teachers on promoting preventive interventions and to identify associated factors, during the novel H1N1 influenza pandemic. A secondary objective was to evaluate their knowledge and vaccination status regarding the novel virus. A cross-sectional study was performed, with the use of a predesigned anonymous, questionnaire, and distributed to all public nursery teachers of Athens, Greece. General etiquette practices were highly acceptable to over 92% of teachers. Those with longer teaching experience promoted simple preventive measures, such as hand washing and use of hand sanitizer, more often while older children were more likely to familiarize with them. However, teachers presented inadequate knowledge concerning the novel virus and their vaccination rates with the pandemic vaccine were unacceptably low (1.1%). Our study showed that promotion of simple preventive measures is feasible and may contribute to the prevention of outbreaks in nursery schools, although knowledge gaps and fear concerning the pandemic vaccine highlight communication issues.

Comparative Analysis of GF-1 and HJ-1 Data to Derive the Optimal Scale for Monitoring Heavy Metal Stress in Rice.

Science.gov (United States)

Wang, Dongmin; Liu, Xiangnan

2018-03-06

Remote sensing can actively monitor heavy metal contamination in crops, but with the increase of satellite sensors, the optimal scale for monitoring heavy metal stress in rice is still unknown. This study focused on identifying the optimal scale by comparing the ability to detect heavy metal stress in rice at various spatial scales. The 2 m, 8 m, and 16 m resolution GF-1 (China) data and the 30 m resolution HJ-1 (China) data were used to invert leaf area index (LAI). The LAI was the input parameter of the World Food Studies (WOFOST) model, and we obtained the dry weight of storage organs (WSO) and dry weight of roots (WRT) through the assimilation method; then, the mass ratio of rice storage organs and roots (SORMR) was calculated. Through the comparative analysis of SORMR at each spatial scale of data, we determined the optimal scale to monitor heavy metal stress in rice. The following conclusions were drawn: (1) SORMR could accurately and effectively monitor heavy metal stress; (2) the 8 m and 16 m images from GF-1 were suitable for monitoring heavy metal stress in rice; (3) 16 m was considered the optimal scale to assess heavy metal stress in rice.

Purification of PON1 from human serum and assessment of enzyme kinetics against metal toxicity.

Science.gov (United States)

Ekinci, Deniz; Beydemir, Sükrü

2010-06-01

Paraoxonase-1 (PON1) is an organophosphate hydrolyser enzyme which has also antioxidant properties in metabolism. Due to its crucial functions, inhibition of the enzyme is undesirable and very dangerous. PON1 enzyme activity should not be altered in any case. Inhibitory investigations of this enzyme are therefore important and useful. Metal toxicology of enzymes has become popular in the recent years. Here, we report the in vitro inhibitory effects of some metal ions, including Pb(+2), Cr(+2), Fe(+2), and Zn(+2), on the activity of human serum PON1 (hPON1; EC 3.1.8.1.). For this purpose, we purified the enzyme from human serum and analyzed the alterations in the enzyme activity in the presence of metal ions. The results show that metal ions exhibit inhibitory effects on hPON1 at low concentrations with IC (50) values ranging from 0.838 to 7.410 mM. Metal ions showed different inhibition mechanisms: lead and iron were competitive, chrome was noncompetitive, and zinc was uncompetitive. Lead was determined to be the most effective inhibitor.

A stable organic-inorganic hybrid layer protected lithium metal anode for long-cycle lithium-oxygen batteries

Science.gov (United States)

Zhu, Jinhui; Yang, Jun; Zhou, Jingjing; Zhang, Tao; Li, Lei; Wang, Jiulin; Nuli, Yanna

2017-10-01

A stable organic-inorganic hybrid layer (OIHL) is direct fabricated on lithium metal surface by the interfacial reaction of lithium metal foil with 1-chlorodecane and oxygen/carbon dioxide mixed gas. This favorable OIHL is approximately 30 μm thick and consists of lithium alkyl carbonate and lithium chloride. The lithium-oxygen batteries with OIHL protected lithium metal anode exhibit longer cycle life (340 cycles) than those with bare lithium metal anode (50 cycles). This desirable performance can be ascribed to the robust OIHL which prevents the growth of lithium dendrites and the corrosion of lithium metal.

Heavy metal uptake and leaching from polluted soil using permeable barrier in DTPA-assisted phytoextraction.

Science.gov (United States)

Zhao, Shulan; Shen, Zhiping; Duo, Lian

2015-04-01

Application of sewage sludge (SS) in agriculture is an alternative technique of disposing this waste. But unreasonable application of SS leads to excessive accumulation of heavy metals in soils. A column experiment was conducted to test the availability of heavy metals to Lolium perenne grown in SS-treated soils following diethylene triamine penta acetic acid (DTPA) application at rates of 0, 10 and 20 mmol kg(-1) soil. In order to prevent metal leaching in DTPA-assisted phytoextraction process, a horizontal permeable barrier was placed below the treated soil, and its effectiveness was also assessed. Results showed that DTPA addition significantly increased metal uptake by L. perenne shoots and metal leaching. Permeable barriers increased metal concentrations in plant shoots and effectively decreased metal leaching from the treated soil. Heavy metals in SS-treated soils could be gradually removed by harvesting L. perenne many times in 1 year and adding low dosage of DTPA days before each harvest.

Method for measuring particulate and gaseous metals in a fluid stream, device for measuring particulate and gaseous metals in a fluid stream

Science.gov (United States)

Farber, Paul S.; Huang, Hann-Shen

2001-01-01

A method for analyzing metal in a fluid is provided comprising maintaining a first portion of a continuous filter media substrate at a temperature coinciding with the phase in which the metal is to be analyzed; contacting the fluid to a first portion of said substrate to retain the metal on the first portion of said substrate; preventing further contact of the fluid to the first portion of substrate; and contacting the fluid to a second portion of said substrate to retain metal on the second portion of the said substrate while simultaneously analyzing the first portion for metal. Also provided is a device for the simultaneous monitoring and analysis of metal in a fluid comprising a continuous filter media substrate; means for maintaining a first portion of said filter media substrate at a temperature coinciding with the phase in which the metal is to be analyzed; a means for contacting the fluid to the first portion of said substrate; a means for preventing further contact of the fluid to the first portion of substrate; a means for contacting the fluid to a second portion of said substrate to retain metal on the second portion of the said substrate; and means for analyzing the first portion for metal.

Phytoremediation of Heavy Metals in Contaminated Water and Soil Using Miscanthus sp. Goedae-Uksae 1.

Science.gov (United States)

Bang, Jihye; Kamala-Kannan, Seralathan; Lee, Kui-Jae; Cho, Min; Kim, Chang-Hwan; Kim, Young-Jin; Bae, Jong-Hyang; Kim, Kyong-Ho; Myung, Hyun; Oh, Byung-Taek

2015-01-01

The aim of this study is to characterize the heavy metal phytoremediation potential of Miscanthus sp. Goedae-Uksae 1, a hybrid, perennial, bio-energy crop developed in South Korea. Six different metals (As, Cu, Pb, Ni, Cd, and Zn) were used for the study. The hybrid grass effectively absorbed all the metals from contaminated soil. The maximum removal was observed for As (97.7%), and minimum removal was observed for Zn (42.9%). Similarly, Goedae-Uksae 1 absorbed all the metals from contaminated water except As. Cd, Pb, and Zn were completely (100%) removed from contaminated water samples. Generally, the concentration of metals in roots was several folds higher than in shoots. Initial concentration of metals highly influenced the phytoremediation rate. The results of the bioconcentration factor, translocation factor, and enrichment coefficient tests indicate that Goedae-Uksae 1 could be used for phytoremediation in a marginally contaminated ecosystem.

Metallic mercury uptake by catalase Part 1 In Vitro metallic mercury uptake by various kind of animals' erythrocytes and purified human erythrocyte catalase

OpenAIRE

劒持,堅志

1980-01-01

The uptake of metallic mercury was studied using erythrocytes with different catalase activities taken from various kind of animals. The results were: 1) The uptake of metallic mercury by erythrocytes paralleled the activity of catalase in the erythrocytes with and without hydrogen peroxide, suggesting that the erythrocyte catalase activity is related to the uptake of metallic mercury. 2) The uptake of metallic mercury occurred not only with purified human erythrocyte catalase but also with h...

Composite metal-hydrogen electrodes for metal-hydrogen batteries. Final report, October 1, 1993 - April 15, 1997

International Nuclear Information System (INIS)

Ruckman, M.W.; Strongin, M.; Weismann, H.

1997-04-01

The purpose of this project is to develop and conduct a feasibility study of metallic thin films (multilayered and alloy composition) produced by advanced sputtering techniques for use as anodes in Ni-metal hydrogen batteries that would be deposited as distinct anode, electrolyte and cathode layers in thin film devices. The materials could also be incorporated in secondary consumer batteries (i.e. type AF(4/3 or 4/5)) which use electrodes in the form of tapes. The project was based on pioneering studies of hydrogen uptake by ultra-thin Pd-capped Nb films, these studies suggested that materials with metal-hydrogen ratios exceeding those of commercially available metal hydride materials and fast hydrogen charging and discharging kinetics could be produced. The project initially concentrated on gas phase and electrochemical studies of Pd-capped niobium films in laboratory-scale NiMH cells. This extended the pioneering work to the wet electrochemical environment of NiMH batteries and exploited advanced synchrotron radiation techniques not available during the earlier work to conduct in-situ studies of such materials during hydrogen charging and discharging. Although batteries with fast charging kinetics and hydrogen-metal ratios approaching unity could be fabricated, it was found that oxidation, cracking and corrosion in aqueous solutions made pure Nb films and multilayers poor candidates for battery application. The project emphasis shifted to alloy films based on known elemental materials used for NiMH batteries. Although commercial NiMH anode materials contain many metals, it was found that 0.24 μm thick sputtered Zr-Ni films cycled at least 50 times with charging efficiencies exceeding 95% and [H]/[M] ratios of 0.7-1.0. Multilayered or thicker Zr-Ni films could be candidates for a thin film NiMH battery that may have practical applications as an integrated power source for modern electronic devices

Polymer thin film as coating layer to prevent corrosion of metal/metal oxide film

Science.gov (United States)

Sarkar, Suman; Kundu, Sarathi

2018-04-01

Thin film of polymer is used as coating layer and the corrosion of metal/metal oxide layer is studied with the variation of the thickness of the coating layer. The thin layer of polystyrene is fabricated using spin coating method on copper oxide (CuO) film which is deposited on glass substrate using DC magnetron sputtering technique. Thickness of the polystyrene and the CuO layers are determined using X-ray reflectivity (XRR) technique. CuO thin films coated with the polystyrene layer are exposed to acetic acid (2.5 v/v% aqueous CH3COOH solution) environments and are subsequently analyzed using UV-Vis spectroscopy and atomic force microscopy (AFM). Surface morphology of the film before and after interaction with the acidic environment is determined using AFM. Results obtained from the XRR and UV-Vis spectroscopy confirm that the thin film of polystyrene acts as an anticorrosion coating layer and the strength of the coating depends upon the polymer layer thickness at a constant acid concentration.

Metal induced embrittlement. Annual report, [March 1, 1987--February 29, 1988

Energy Technology Data Exchange (ETDEWEB)

Hoagland, R.G.

1988-11-01

This program is investigating the causes of embrittlement that occur in certain solid metals when exposed to liquid metals. The degree of embrittlement varies enormously among different solid/liquid pairs as witness, for example, the modest loss of load carrying, ability induced in carbon steels by Pb or the profound embrittlment of aluminum (particularly high strength) alloys by Hg and Ga. The structure of this study involves two types of activities: an experimental fracture mechanics study of the behavior of certain solid metals in liquid metals, and a theoretical study on an atomic scale of the crack tip deformation and extension behavior by means of atomistic simulation. This research, which began March 1, 1987, has completed its 20 month. A brief synopsis is given of performance in each of the areas of activity during the past year.

The Effect of 1-Pentylamine as Solid Electrolyte Interphase Precursor on Lithium Metal Anodes

International Nuclear Information System (INIS)

Ding, Markus S.; Koch, Stephan L.; Passerini, Stefano

2017-01-01

Highlights: • Manufacturing of a well-controlled artificial SEI on lithium metal electrodes. • Native SEI-free lithium electrodes. • Lithium electrodes with decreased impedance and overpotential due to artificial SEI. • Process development to remove influence of native SEI. • 1-pentylamine in n-pentane as artificial SEI precursor for lithium metal. - Abstract: In this study, the formation of an artificial primary solid electrolyte interphase on a fresh Li surface, via reaction with 1-pentylamine (PA), is reported, allowing removing the influence of the metal electrode’s prior history. Electrochemical impedance spectroscopy, galvanostatic cycling, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) are used in order to investigate the effect of PA as solid electrolyte interphase precursor on Li metal. It is shown that pretreating native SEI-free Li metal surfaces with 1 M PA in n-pentane sharply decreases the electrode impedance and overpotential with respect to the treatment with only n-pentane. The treatment with 1 M PA in n-pentane results in surface roughening, but no increase of dendrite formation upon cycling. However, the use of higher PA concentration (5 M) increases impedance and overpotential and leads to dendrite growth.

Trials in the prevention of type 1 diabetes: current and future.

Science.gov (United States)

Wherrett, Diane K

2014-08-01

A major thrust in type 1 diabetes research is stopping the destruction of beta cells that leads to type 1 diabetes. Research over the past 30 years has defined genetic factors and evidence of autoimmunity that have led to the development of robust prediction models in those at high risk for type 1 diabetes. The ability to identify those at risk and the development of new agents and of collaborative research networks has led to multiple trials aimed at preventing beta cell loss. Trials at all stages of beta cell loss have been conducted: primary prevention (prior to the development of autoimmunity); secondary prevention (after autoantibodies are found) and tertiary prevention (intervening after diagnosis to maintain remaining beta cells). Studies have shown mixed results; evidence of maintained insulin secretion after the time of diagnosis has been described in a number of studies, and primary and secondary prevention is proving to be elusive. Much has been learned from the increasing number of studies in the field in terms of network creation, study design and choice of intervention that will facilitate new avenues of investigation. Copyright © 2014 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

Metals and Neurodegeneration [version 1; referees: 3 approved

Directory of Open Access Journals (Sweden)

Pan Chen

2016-03-01

Full Text Available Metals play important roles in the human body, maintaining cell structure and regulating gene expression, neurotransmission, and antioxidant response, to name a few. However, excessive metal accumulation in the nervous system may be toxic, inducing oxidative stress, disrupting mitochondrial function, and impairing the activity of numerous enzymes. Damage caused by metal accumulation may result in permanent injuries, including severe neurological disorders. Epidemiological and clinical studies have shown a strong correlation between aberrant metal exposure and a number of neurological diseases, including Alzheimer’s disease, amyotrophic lateral sclerosis, autism spectrum disorders, Guillain–Barré disease, Gulf War syndrome, Huntington’s disease, multiple sclerosis, Parkinson’s disease, and Wilson’s disease. Here, we briefly survey the literature relating to the role of metals in neurodegeneration.

On the Chemical Abundances of Miras in Clusters: V1 in the Metal-rich Globular NGC 5927

Science.gov (United States)

D’Orazi, V.; Magurno, D.; Bono, G.; Matsunaga, N.; Braga, V. F.; Elgueta, S. S.; Fukue, K.; Hamano, S.; Inno, L.; Kobayashi, N.; Kondo, S.; Monelli, M.; Nonino, M.; Przybilla, N.; Sameshima, H.; Saviane, I.; Taniguchi, D.; Thevenin, F.; Urbaneja-Perez, M.; Watase, A.; Arai, A.; Bergemann, M.; Buonanno, R.; Dall’Ora, M.; Da Silva, R.; Fabrizio, M.; Ferraro, I.; Fiorentino, G.; Francois, P.; Gilmozzi, R.; Iannicola, G.; Ikeda, Y.; Jian, M.; Kawakita, H.; Kudritzki, R. P.; Lemasle, B.; Marengo, M.; Marinoni, S.; Martínez-Vázquez, C. E.; Minniti, D.; Neeley, J.; Otsubo, S.; Prieto, J. L.; Proxauf, B.; Romaniello, M.; Sanna, N.; Sneden, C.; Takenaka, K.; Tsujimoto, T.; Valenti, E.; Yasui, C.; Yoshikawa, T.; Zoccali, M.

2018-03-01

We present the first spectroscopic abundance determination of iron, α-elements (Si, Ca, and Ti), and sodium for the Mira variable V1 in the metal-rich globular cluster NGC 5927. We use high-resolution (R ∼ 28,000), high signal-to-noise ratio (∼200) spectra collected with WINERED, a near-infrared (NIR) spectrograph covering simultaneously the wavelength range 0.91–1.35 μm. The effective temperature and the surface gravity at the pulsation phase of the spectroscopic observation were estimated using both optical (V) and NIR time-series photometric data. We found that the Mira is metal-rich ([Fe/H] = ‑0.55 ± 0.15) and moderately α-enhanced ([α/Fe] = 0.15 ± 0.01, σ = 0.2). These values agree quite well with the mean cluster abundances based on high-resolution optical spectra of several cluster red giants available in the literature ([Fe/H] = ‑ 0.47 ± 0.06, [α/Fe] = + 0.24 ± 0.05). We also found a Na abundance of +0.35 ± 0.20 that is higher than the mean cluster abundance based on optical spectra (+0.18 ± 0.13). However, the lack of similar spectra for cluster red giants and that of corrections for departures from local thermodynamical equilibrium prevents us from establishing whether the difference is intrinsic or connected with multiple populations. These findings indicate a strong similarity between optical and NIR metallicity scales in spite of the difference in the experimental equipment, data analysis, and in the adopted spectroscopic diagnostics. Based on spectra collected with the WINERED spectrograph available as a visitor instrument at the ESO New Technology Telescope (NTT), La Silla, Chile (ESO Proposal: 098.D-0878(A), PI: G. Bono).

assessment of heavy metals concentration in drinking water ...

African Journals Online (AJOL)

userpc

guidelines (WHO 2005). Findings suggest that continues water quality monitoring should be carried out to check the concentration levels of heavy metals in that area, to prevent them from been above the limit of WHO. Keywords: Atomic Absorption Spectrophotometers, Heavy Metals, Water, Kauru Local. Government Area.

Directed light fabrication of refractory metals and alloys

International Nuclear Information System (INIS)

Fonseca, J.C.; Lewis, G.K.; Dickerson, P.G.; Nemec, R.B.

1999-01-01

This report covers deposition of refractory pure metals and alloys using the Directed Light Fabrication (DLF) process and represents progress in depositing these materials through September 1998. In extending the DLF process technology to refractory metals for producing fully dense, structurally sound deposits, several problems have become evident. (1) Control of porosity in DLF-deposited refractory metal is difficult because of gases, apparently present in commercially purchased refractory metal powder starting materials. (2) The radiant heat from the molten pool during deposition melts the DLF powder feed nozzle. (3) The high reflectivity of molten refractory metals, at the Nd-YAG laser wavelength (1.06microm), produces damaging back reflections to the optical train and fiber optic delivery system that can terminate DLF processing. (4) The current limits on the maximum available laser power to prevent back reflection damage limit the parameter range available for densification of refractory metals. The work to date concentrated on niobium, W-25Re, and spherodized tungsten. Niobium samples, made from hydride-dehydride powder, had minimal gas porosity and the deposition parameters were optimized; however, test plates were not made at this time. W-25Re samples, containing sodium and potassium from a precipitation process, were made and porosity was a problem for all samples although minimized with some process parameters. Deposits made from potassium reduced tungsten that was plasma spherodized were made with minimized porosity. Results of this work indicate that further gas analysis of starting powders and de-gassing of starting powders and/or gas removal during deposition of refractory metals is required

Mutations in Arabidopsis Yellow Stripe-Like1 and Yellow Stripe-Like3 Reveal Their Roles in Metal Ion Homeostasis and Loading of Metal Ions in Seeds1

Science.gov (United States)

Waters, Brian M.; Chu, Heng-Hsuan; DiDonato, Raymond J.; Roberts, Louis A.; Eisley, Robynn B.; Lahner, Brett; Salt, David E.; Walker, Elsbeth L.

2006-01-01

Here, we describe two members of the Arabidopsis (Arabidopsis thaliana) Yellow Stripe-Like (YSL) family, AtYSL1 and AtYSL3. The YSL1 and YSL3 proteins are members of the oligopeptide transporter family and are predicted to be integral membrane proteins. YSL1 and YSL3 are similar to the maize (Zea mays) YS1 phytosiderophore transporter (ZmYS1) and the AtYSL2 iron (Fe)-nicotianamine transporter, and are predicted to transport metal-nicotianamine complexes into cells. YSL1 and YSL3 mRNAs are expressed in both root and shoot tissues, and both are regulated in response to the Fe status of the plant. β-Glucuronidase reporter expression, driven by YSL1 and YSL3 promoters, reveals expression patterns of the genes in roots, leaves, and flowers. Expression was highest in senescing rosette leaves and cauline leaves. Whereas the single mutants ysl1 and ysl3 had no visible phenotypes, the ysl1ysl3 double mutant exhibited Fe deficiency symptoms, such as interveinal chlorosis. Leaf Fe concentrations are decreased in the double mutant, whereas manganese, zinc, and especially copper concentrations are elevated. In seeds of double-mutant plants, the concentrations of Fe, zinc, and copper are low. Mobilization of metals from leaves during senescence is impaired in the double mutant. In addition, the double mutant has reduced fertility due to defective anther and embryo development. The proposed physiological roles for YSL1 and YSL3 are in delivery of metal micronutrients to and from vascular tissues. PMID:16815956

Mycobacteria, Metals, and the Macrophage

Science.gov (United States)

Niederweis, Michael; Wolschendorf, Frank; Mitra, Avishek; Neyrolles, Olivier

2015-01-01

Summary Mycobacterium tuberculosis is a facultative intracellular pathogen that thrives inside host macrophages. A key trait of M. tuberculosis is to exploit and manipulate metal cation trafficking inside infected macrophages to ensure survival and replication inside the phagosome. Here we describe the recent fascinating discoveries that the mammalian immune system responds to infections with M. tuberculosis by overloading the phagosome with copper and zinc, two metals which are essential nutrients in small quantities but are toxic in excess. M. tuberculosis has developed multi-faceted resistance mechanisms to protect itself from metal toxicity including control of uptake, sequestration inside the cell, oxidation, and efflux. The host response to infections combines this metal poisoning strategy with nutritional immunity mechanisms that deprive M. tuberculosis from metals such as iron and manganese to prevent bacterial replication. Both immune mechanisms rely on the translocation of metal transporter proteins to the phagosomal membrane during the maturation process of the phagosome. This review summarizes these recent findings and discusses how metal-targeted approaches might complement existing TB chemotherapeutic regimens with novel anti-infective therapies. PMID:25703564

Metal decontamination for waste minimization using liquid metal refining technology

International Nuclear Information System (INIS)

Joyce, E.L. Jr.; Lally, B.; Ozturk, B.; Fruehan, R.J.

1993-01-01

The current Department of Energy Mixed Waste Treatment Project flowsheet indicates that no conventional technology, other than surface decontamination, exists for metal processing. Current Department of Energy guidelines require retrievable storage of all metallic wastes containing transuranic elements above a certain concentration. This project is in support of the National Mixed Low Level Waste Treatment Program. Because of the high cost of disposal, it is important to develop an effective decontamination and volume reduction method for low-level contaminated metals. It is important to be able to decontaminate complex shapes where surfaces are hidden or inaccessible to surface decontamination processes and destruction of organic contamination. These goals can be achieved by adapting commercial metal refining processes to handle radioactive and organic contaminated metal. The radioactive components are concentrated in the slag, which is subsequently vitrified; hazardous organics are destroyed by the intense heat of the bath. The metal, after having been melted and purified, could be recycled for use within the DOE complex. In this project, we evaluated current state-of-the-art technologies for metal refining, with special reference to the removal of radioactive contaminants and the destruction of hazardous organics. This evaluation was based on literature reports, industrial experience, plant visits, thermodynamic calculations, and engineering aspects of the various processes. The key issues addressed included radioactive partitioning between the metal and slag phases, minimization of secondary wastes, operability of the process subject to widely varying feed chemistry, and the ability to seal the candidate process to prevent the release of hazardous species

U.S. Department of Energy National Center of Excellence for Metals Recycle

International Nuclear Information System (INIS)

Adams, V.; Bennett, M.; Bishop, L.

1998-06-01

The US Department of Energy (DOE) National Center of Excellence for Metals Recycle has recently been established. The vision of this new program is to develop a DOE culture that promotes pollution prevention by considering the recycle and reuse of metal as the first and primary disposition option and burial as a last option. The Center of Excellence takes the approach that unrestricted release of metal is the first priority because it is the most cost-effective disposition pathway. Where this is not appropriate, restricted release, beneficial reuse, and stockpile of ingots are considered. The Center has gotten off to a fast start. Current recycling activities include the sale of 40,000 tons of scrap metal from the East Tennessee Technology Park (formerly K-25 Plant) K-770 scrap yard, K-1064 surplus equipment and machinery, 7,000 PCB-contaminated drums, 12,000 tons of metal from the Y-12 scrap yard, and 1,000 metal pallets. In addition, the Center of Excellence is developing a toolbox for project teams that will contain a number of specific tools to facilitate metals recycle. This Internet-based toolbox will include primers, computer software, and case studies designed to help sites to perform life cycle analysis, perform ALARA (As Low As is Reasonably Achievable) analysis for radiation exposures, produce pollution prevention information and documentation, manage their materials inventory, produce independent government estimates, and implement sale/service contracts. The use of these tools is described for two current activities: disposition of scrap metal in the Y-12 scrap yard, and disposition of PCB-contaminated drums. Members of the Center look forward to working with all DOE sites, regulatory authorities, the private sector, and other stakeholders to achieve the metals recycle goals

[Heavy metal poisoning and renal injury in children].

Science.gov (United States)

Rong, Li-Ping; Xu, Yuan-Yuan; Jiang, Xiao-Yun

2014-04-01

Along with global environmental pollution resulting from economic development, heavy metal poisoning in children has become an increasingly serious health problem in the world. It can lead to renal injury, which tends to be misdiagnosed due to the lack of obvious or specific early clinical manifestations in children. Early prevention, diagnosis and intervention are valuable for the recovery of renal function and children's good health and growth. This paper reviews the mechanism of renal injury caused by heavy metal poisoning in children, as well as the clinical manifestations, diagnosis, and prevention and treatment of renal injury caused by lead, mercury, cadmium, and chromium.

Antimicrobial resistance challenged with metal-based antimicrobial macromolecules.

Science.gov (United States)

Abd-El-Aziz, Alaa S; Agatemor, Christian; Etkin, Nola

2017-02-01

Antimicrobial resistance threatens the achievements of science and medicine, as it deactivates conventional antimicrobial therapeutics. Scientists respond to the threat by developing new antimicrobial platforms to prevent and treat infections from these resistant strains. Metal-based antimicrobial macromolecules are emerging as an alternative to conventional platforms because they combine multiple mechanisms of action into one platform due to the distinctive properties of metals. For example, metals interact with intracellular proteins and enzymes, and catalyse various intracellular processes. The macromolecular architecture offers a means to enhance antimicrobial activity since several antimicrobial moieties can be conjugated to the scaffold. Further, these macromolecules can be fabricated into antimicrobial materials for contact-killing medical implants, fabrics, and devices. As volatilization or leaching out of the antimicrobial moieties from the macromolecular scaffold is reduced, these medical implants, fabrics, and devices can retain their antimicrobial activity over an extended period. Recent advances demonstrate the potential of metal-based antimicrobial macromolecules as effective platforms that prevent and treat infections from resistant strains. In this review these advances are thoroughly discussed within the context of examples of metal-based antimicrobial macromolecules, their mechanisms of action and biocompatibility. Copyright © 2016 Elsevier Ltd. All rights reserved.

Conclusive experimental study of prevention measures against sodium combustion residuum reignition. Run-F9-1, Run-F9-2

International Nuclear Information System (INIS)

Ishikawa, Hiroyasu; Ohno, Shuji; Miyahara, Shinya

2004-04-01

Nitrogen gas can be an extinguisher or a mitigating material in the case of sodium leak and fire accident in an air atmosphere, which may occur at a liquid metal cooled nuclear power plant. However, sodium combustion residuum sometimes reignites in the air atmosphere even at room temperature when it was produced by nitrogen gas injection to the burning sodium. Then, in this study we executed conclusive experiments of prevention measures against sodium combustion residuum reignition by a mixture of carbon-dioxide (CO 2 ) gas, humidity and nitrogen gas. The experiments were carried out with the FRAT-1 test equipment; the humidity conditions were changed in air which were used to sodium combustion atmosphere and exposure air for confirmation of prevented combustion residue reignition. First of all, the sodium of about 2.5 kg was leaked in air atmosphere, and next, the sodium combustion was stopped by nitrogen gas injection. Next, the combustion residuum was cooled in the nitrogen atmosphere, and then the combustion residuum was exposed to atmosphere of carbon-dioxide (4%); humidity (6000vppm); oxygen (3%)-nitrogen (based gas) mixture. It was confirmed that the combustion residuum was not reignition even if exposed to the air atmosphere again at the end of experiment. We had confirmed that the prevention measures against sodium combustion residuum reignition to establish by this research were effective. (author)

Resolvin D1 prevents smoking-induced emphysema and promotes lung tissue regeneration.

Science.gov (United States)

Kim, Kang-Hyun; Park, Tai Sun; Kim, You-Sun; Lee, Jae Seung; Oh, Yeon-Mok; Lee, Sang-Do; Lee, Sei Won

2016-01-01

Emphysema is an irreversible disease that is characterized by destruction of lung tissue as a result of inflammation caused by smoking. Resolvin D1 (RvD1), derived from docosahexaenoic acid, is a novel lipid that resolves inflammation. The present study tested whether RvD1 prevents smoking-induced emphysema and promotes lung tissue regeneration. C57BL/6 mice, 8 weeks of age, were randomly divided into four groups: control, RvD1 only, smoking only, and smoking with RvD1 administration. Four different protocols were used to induce emphysema and administer RvD1: mice were exposed to smoking for 4 weeks with poly(I:C) or to smoking only for 24 weeks, and RvD1 was injected within the smoking exposure period to prevent regeneration or after completion of smoking exposure to assess regeneration. The mean linear intercept and inflammation scores were measured in the lung tissue, and inflammatory cells and cytokines were measured in the bronchoalveolar lavage fluid. Measurements of mean linear intercept showed that RvD1 significantly attenuated smoking-induced lung destruction in all emphysema models. RvD1 also reduced smoking-induced inflammatory cell infiltration, which causes the structural derangements observed in emphysema. In the 4-week prevention model, RvD1 reduced the smoking-induced increase in eosinophils and interleukin-6 in the bronchoalveolar lavage fluid. In the 24-week prevention model, RvD1 also reduced the increased neutrophils and total cell counts induced by smoking. RvD1 attenuated smoking-induced emphysema in vivo by reducing inflammation and promoting tissue regeneration. This result suggests that RvD1 may be useful in the prevention and treatment of emphysema.

Assessment of heavy metals concentration in drinking water ...

African Journals Online (AJOL)

The concentration of all the metals were considerably found to be below the limit permitted by WHO's drinking water guidelines (WHO 2005). Findings suggest that continues water quality monitoring should be carried out to check the concentration levels of heavy metals in that area, to prevent them from been above the limit ...

Robust half-metallicity at the zincblende CrTe(0 0 1) surfaces and its interface with ZnTe(0 0 1)

International Nuclear Information System (INIS)

Ahmadian, F.; Abolhassani, M.R.; Hashemifar, S.J.; Elahi, M.

2010-01-01

All electron full potential calculations based on spin density functional theory are performed to study cubic zincblende (ZB) and hexagonal NiAs structures of bulk CrTe, free (0 0 1) surfaces of ZB CrTe, and interface of ZB CrTe with ZnTe(0 0 1). The ferromagnetic NiAs structure is reported to be about 0.26 eV more stable than the ferromagnetic ZB phase while ZB CrTe is found to be a half-metallic ferromagnet with a half-metallic gap of about 2.90 eV. Thermodynamic stability of CrTe(0 0 1) surfaces are studied in the framework of ab-initio thermodynamic. The obtained phase diagram evidences more stability of the Te terminated surface compared with the Cr termination. We discuss that both Te and Cr ideal terminations of CrTe(0 0 1) retain bulk-like half-metallic property but with a reduced half-metallic gap compared with bulk value. The structural, electronic, magnetic, and band alignment properties of the ZB CrTe/ZnTe(0 0 1) interface are computed and a rather large minority valence band offset of about 1.09 eV is observed in this heterojunction.

Cytochrome P450 CYP1A1: wider roles in cancer progression and prevention

International Nuclear Information System (INIS)

Androutsopoulos, Vasilis P; Tsatsakis, Aristidis M; Spandidos, Demetrios A

2009-01-01

CYP1A1 is one of the main cytochrome P450 enzymes, examined extensively for its capacity to activate compounds with carcinogenic properties. Continuous exposure to inhalation chemicals and environmental carcinogens is thought to increase the level of CYP1A1 expression in extrahepatic tissues, through the aryl hydrocarbon receptor (AhR). Although the latter has long been recognized as a ligand-induced transcription factor, which is responsible for the xenobiotic activating pathway of several phase I and phase II metabolizing enzymes, recent evidence suggests that the AhR is involved in various cell signaling pathways critical to cell cycle regulation and normal homeostasis. Disregulation of these pathways is implicated in tumor progression. In addition, it is becoming increasingly evident that CYP1A1 plays an important role in the detoxication of environmental carcinogens, as well as in the metabolic activation of dietary compounds with cancer preventative activity. Ultimately the contribution of CYP1A1 to cancer progression or prevention may depend on the balance of procarcinogen activation/detoxication and dietary natural product extrahepatic metabolism

Metal artefact reduction in MRI at both 1.5 and 3.0 T using slice encoding for metal artefact correction and view angle tilting

Science.gov (United States)

Reichert, M; Morelli, J N; Nittka, M; Attenberger, U; Runge, V M

2015-01-01

Objective: To compare metal artefact reduction in MRI at both 3.0 T and 1.5 T using different sequence strategies. Methods: Metal implants of stainless steel screw and plate within agarose phantoms and tissue specimens as well as three patients with implants were imaged at both 1.5 T and 3.0 T, using view angle tilting (VAT), slice encoding for metal artefact correction with VAT (SEMAC-VAT) and conventional sequence. Artefact reduction in agarose phantoms was quantitatively assessed by artefact volume measurements. Blinded reads were conducted in tissue specimen and human imaging, with respect to artefact size, distortion, blurring and overall image quality. Wilcoxon and Friedman tests for multiple comparisons and intraclass correlation coefficient (ICC) for interobserver agreement were performed with a significant level of p 3.0 T (p 3.0 T. Advances in knowledge: The feasibility of metal artefact reduction with SEMAC-VAT was demonstrated at 3.0-T MR. SEMAC-VAT significantly reduced metal artefacts at both 1.5 and 3.0 T. SEMAC-VAT allowed for better visualization of the tissue structures adjacent to the metal implants. SEMAC-VAT produced consistently better image quality in both tissue specimen and human imaging. PMID:25613398

Development of casting technology for manufacturing metal rods with simulated metallic spent fuels

International Nuclear Information System (INIS)

Lee, D. B.; Lee, Y. S.; Woo, Y. M.; Jang, S. J.; Kim, J. D; Kim, C. K.; Shin, Y. J.; Lee, J. H.

1999-01-01

The advanced casting equipment based on the directional solidification method was developed for manufacturing the uranium metal rod having 13.5 mm diameter and 1,200 mm length. In order to prevent surface-shrunk holes revealed easily in course of casting the small diameter and long rods, the vacuum casting furnace has the four pre-heaters equipped with temperature controller. On the other hand, the computer simulation to estimate the defective location and to analyze the solidus behavior of molten uranium in the mold were also performed by using MAGMA Code. As a result of the experimental and theoretical study, the sound rod has successfully been manufactured

Directed light fabrication of refractory metals and alloys

International Nuclear Information System (INIS)

Fonseca, J.C.; Lewis, G.K.; Dickerson, P.G.; Nemec, R.B.

1999-01-01

This report covers work performed under Order No. FA0000020 AN Contract DE-AC12-76SN00052 for deposition of refractory pure metals and alloys using the Directed Light Fabrication (DLF) process and represents the progress in depositing these materials through September 1998. In extending the DLF process technology to refractory metals for producing fully dense, structurally sound deposits, several problems have become evident. 1. Control of porosity in DLF-deposited refractory metal is difficult because of gases, apparently present in commercially purchased refractory metal powder starting materials. 2. The radiant heat from the molten pool during deposition melts the DLF powder feed nozzle. 3. The high reflectivity of molten refractory metals, at the Nd-YAG laser wavelength (1.06microm), produces damaging back reflections to the optical train and fiber optic delivery system that can terminate DLF processing. 4. The current limits on the maximum available laser power to prevent back reflection damage limit the parameter range available for densification of refractory metals. The work to date concentrated on niobium, W-25Re, and spherodized tungsten. Niobium samples, made from hydride-dehydride powder, had minimal gas porosity and the deposition parameters were optimized; however, test plates were not made at this time. W-25Re samples, containing sodium and potassium from a precipitation process, were made and porosity was a problem for all samples although minimized with some process parameters. Deposits made from potassium reduced tungsten that was plasma spherodized were made with minimized porosity. Results of this work indicate that further gas analysis of starting powders and de-gassing of starting powders and/or gas removal during deposition of refractory metals is required

The effect of motion patterns on edge-loading of metal-on-metal hip resurfacing.

Science.gov (United States)

Mellon, S J; Kwon, Y-M; Glyn-Jones, S; Murray, D W; Gill, H S

2011-12-01

The occurrence of pseudotumours (soft tissue masses relating to the hip joint) following metal-on-metal hip resurfacing arthroplasty (MoMHRA) has been associated with high serum metal ion levels and consequently higher than normal bearing wear. We investigated the relationship between serum metal ion levels and contact stress on the acetabular component of MoMHRA patients for two functional activities; gait and stair descent. Four subjects with MoMHRA, who had their serum metal ion levels measured, underwent motion analysis followed by CT scanning. Their motion capture data was combined with published hip contact forces and finite element models representing 14% (peak force) and 60% (end of stance) of the gait cycle and 52% (peak force) of stair descent activity were created. The inclination angle of the acetabular component was increased by 10° in 1° intervals and the contact stresses were determined at each interval for each subject. When the inclination angle was altered in such a way as to cause the hip contact force to pass through the edge of the acetabular component edge-loading occurred. Edge-loading increased the contact stress by at least 50%; the maximum increase was 108%. Patients with low serum metal ion levels showed no increase in contact stress at peak force during gait or stair descent. Patients with high serum metal ion levels exhibited edge-loading with an increase to the inclination angle of their acetabular components. The increase in inclination angle that induced edge-loading for these subjects was less than the inter-subject variability in the angle of published hip contact forces. The results of this study suggest that high serum metal ion levels are the result of inclination angle influenced edge-loading but that edge-loading cannot be attributed to inclination angle alone and that an individual's activity patterns can reduce or even override the influence of a steep acetabular component and prevent edge-loading. Copyright © 2011 IPEM

Recycle of contaminated scrap metal, Volume 1. Semi-annual report, September 1993--January 1996

International Nuclear Information System (INIS)

1996-07-01

Catalytic Extraction Processing (CEP) has been demonstrated to be a robust, one-step process that is relatively insensitive to wide variations in waste composition and is applicable to a broad spectrum of DOE wastes. Catalytic Processing Unit (CPU) design models have been validated through experimentation to provide a high degree of confidence in our ability to design a bulk solids CPU for processing DOE wastes. Two commercial CEP facilities have been placed in commission and are currently processing mixed low level wastes. These facilities provide a compelling indication of the maturity, regulatory acceptance, and commercial viability of CEP. In concert with the DOE, Nolten Metal Technology designed a program which would challenge preconceptions of the limitations of waste processing technologies: demonstrate the recycling of ferrous and non-ferrous metals--to establish that radioactively contaminated scrap metal could be converted to high-grade, ferrous and non-ferrous alloys which can be reused by DOE or reintroduced into commerce; immobilize radionuclides--that CEP would concentrate the radionuclides in a durable vitreous phase, minimize secondary waste generation and stabilize and reduce waste volume; destroy hazardous organics--that CEP would convert hazardous organics to valuable industrial gases, which could be used as an energy source; recover volatile heavy metals--that CEP's off-gas treatment system would capture volatile heavy metals, such as mercury and lead; establish that CEP is economical for processing contaminated scrap metal in the DOE inventory. The execution of this program resulted in all objectives being met. Volume I covers: executive summary; task 1.1 design CEP system; Task 1.2 experimental test plan; Task 1.3 experimental testing

Recycle of contaminated scrap metal, Volume 1. Semi-annual report, September 1993--January 1996

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-07-01

Catalytic Extraction Processing (CEP) has been demonstrated to be a robust, one-step process that is relatively insensitive to wide variations in waste composition and is applicable to a broad spectrum of DOE wastes. Catalytic Processing Unit (CPU) design models have been validated through experimentation to provide a high degree of confidence in our ability to design a bulk solids CPU for processing DOE wastes. Two commercial CEP facilities have been placed in commission and are currently processing mixed low level wastes. These facilities provide a compelling indication of the maturity, regulatory acceptance, and commercial viability of CEP. In concert with the DOE, Nolten Metal Technology designed a program which would challenge preconceptions of the limitations of waste processing technologies: demonstrate the recycling of ferrous and non-ferrous metals--to establish that radioactively contaminated scrap metal could be converted to high-grade, ferrous and non-ferrous alloys which can be reused by DOE or reintroduced into commerce; immobilize radionuclides--that CEP would concentrate the radionuclides in a durable vitreous phase, minimize secondary waste generation and stabilize and reduce waste volume; destroy hazardous organics--that CEP would convert hazardous organics to valuable industrial gases, which could be used as an energy source; recover volatile heavy metals--that CEP`s off-gas treatment system would capture volatile heavy metals, such as mercury and lead; establish that CEP is economical for processing contaminated scrap metal in the DOE inventory. The execution of this program resulted in all objectives being met. Volume I covers: executive summary; task 1.1 design CEP system; Task 1.2 experimental test plan; Task 1.3 experimental testing.

Community-Based Risk Communication Survey: Risk Prevention Behaviors in Communities during the H1N1 crisis, 2010.

Science.gov (United States)

Kim, Soo Jeong; Han, Jin A; Lee, Tae-Yong; Hwang, Tae-Yoon; Kwon, Keun-Sang; Park, Ki Soo; Lee, Kyung Jong; Kim, Moon Shik; Lee, Soon Young

2014-02-01

The present study aimed to investigate the prevalence of and factors associated with H1N1 preventive behaviors in a community-based population. A cross-sectional study was conducted in three urban and two rural communities in Korea. Interviews were conducted with 3462 individuals (1608 men and 1854 women) aged ≥ 19 years during February-March 2010. Influenza-related information including anxiety, preventive behaviors and their perceived effectiveness, vaccination status, past influenza-like illness symptoms, and sources of and trust in information was obtained. Among 3462 participants, 173 reported experiencing influenza-like illness symptoms within the past 12 months. The mean H1N1 preventive behavior score was 25.5 ± 5.5 (out of a possible 40). The percent of participants reporting high perceived effectiveness and high anxiety was 46.2% and 21.4%, respectively. After controlling for potential confounders, H1N1 preventive behavior scores were predicted by a high (β = 3.577, p < 0.001) or moderate (β = 2.529, p < 0.001) perception of their effectiveness. Similarly, moderate (β = 1.516, p < 0.001) and high (β = 4.103, p < 0.001) anxiety scores predicted high preventive behavior scores. Effective methods of promoting population behavior change may be nationwide campaigns through mass media, as well as education and promotion by health care providers and broadcasters.

1.06 μm reflectivity measurements of metal optics

International Nuclear Information System (INIS)

Saito, T.T.

1975-01-01

The equipment and technique for the measurement of 1.06 μm reflectivity of diamond turned, diamond turned/polished, and polished metal mirrors is presented. From an analysis of repeatability and systematic errors it is concluded the precision of the measurements is 0.003 and the accuracy is 0.005. Diamond turned mirrors compete well with the best 1 μm reflectivity values reported and are superior to polished surfaces studied in this work. (U.S.)

Metallic coating of microspheres

International Nuclear Information System (INIS)

Meyer, S.F.

1980-01-01

Extremely smooth, uniform metal coatings of micrometer thicknesses on microscopic glass spheres (microspheres) are often needed as targets for inertial confinement fusion (ICF) experiments. The first part of this paper reviews those methods used successfully to provide metal coated microspheres for ICF targets, including magnetron sputtering, electro- and electroless plating, and chemical vapor pyrolysis. The second part of this paper discusses some of the critical aspects of magnetron sputter coating of microspheres, including substrate requirements, the sticking of microspheres during coating (preventing a uniform coating), and the difficulties in growing the desired dense, smooth, uniform microstructure on continuously moving spherical substrates

Base Metal Co-Fired Multilayer Piezoelectrics

Directory of Open Access Journals (Sweden)

Lisheng Gao

2016-03-01

Full Text Available Piezoelectrics have been widely used in different kinds of applications, from the automobile industry to consumer electronics. The novel multilayer piezoelectrics, which are inspired by multilayer ceramic capacitors, not only minimize the size of the functional parts, but also maximize energy efficiency. Development of multilayer piezoelectric devices is at a significant crossroads on the way to achieving low costs, high efficiency, and excellent reliability. Concerning the costs of manufacturing multilayer piezoelectrics, the trend is to replace the costly noble metal internal electrodes with base metal materials. This paper discusses the materials development of metal co-firing and the progress of integrating current base metal chemistries. There are some significant considerations in metal co-firing multilayer piezoelectrics: retaining stoichiometry with volatile Pb and alkaline elements in ceramics, the selection of appropriate sintering agents to lower the sintering temperature with minimum impact on piezoelectric performance, and designing effective binder formulation for low pO2 burnout to prevent oxidation of Ni and Cu base metal.

AN EXTREMELY CARBON-RICH, EXTREMELY METAL-POOR STAR IN THE SEGUE 1 SYSTEM

International Nuclear Information System (INIS)

Norris, John E.; Yong, David; Gilmore, Gerard; Wyse, Rosemary F. G.; Frebel, Anna

2010-01-01

We report the analysis of high-resolution, high signal-to-noise ratio, spectra of an extremely metal-poor, extremely C-rich red giant, Seg 1-7, in Segue 1-described in the literature alternatively as an unusually extended globular cluster or an ultra-faint dwarf galaxy. The radial velocity of Seg 1-7 coincides precisely with the systemic velocity of Segue 1, and its chemical abundance signature of [Fe/H] = -3.52, [C/Fe] = +2.3, [N/Fe] = +0.8, [Na/Fe] = +0.53, [Mg/Fe] = +0.94, [Al/Fe] = +0.23, and [Ba/Fe] < -1.0 is similar to that of the rare and enigmatic class of Galactic halo objects designated CEMP-no (carbon-rich, extremely metal-poor with no enhancement (over solar ratios) of heavy neutron-capture elements). This is the first star in a Milky Way 'satellite' that unambiguously lies on the metal-poor, C-rich branch of the Aoki et al. bimodal distribution of field halo stars in the ([C/Fe], [Fe/H])-plane. Available data permit us only to identify Seg 1-7 as a member of an ultra-faint dwarf galaxy or as debris from the Sgr dwarf spheroidal galaxy. In either case, this demonstrates that at extremely low abundance, [Fe/H ] <-3.0, star formation and associated chemical evolution proceeded similarly in the progenitors of both the field halo and satellite systems. By extension, this is consistent with other recent suggestions that the most metal-poor dwarf spheroidal and ultra-faint dwarf satellites were the building blocks of the Galaxy's outer halo.

Phytoremediation of metals contaminated dredged sediments: Use of synthetic chelates in metals phytoextraction

Science.gov (United States)

Sahut, C.; Geniaut, G.; Lillo, M. P.

2003-05-01

(in Times 10 points) The waterways maintenance leads to a large volume of dredged polluted sediments, to be disposed of, every year. As the economic disposal of dredged sediment is a single line along the stream they can behave as a sink of pollutant and a migration in the environment is observed. Chelate-enhanced phytoremediation has been proposed as an effective tool for the extraction of heavy metals from dredged sediment by plants. Lysimeters studies were conducted to study the phytoremediation of sediments with EDTA and lactic acid used as synthetic chelators. EDTA appeared to enhance metal solubility by plant uptake did not increase accordingly. Futhermore EDTA enhance metal leaching which could lead 10 groungwater pollution. To prevent these unwanted side-effects, careful management of phytoremediation and of the use of EDTA seems necessary.

Serpentine endophytic bacterium Pseudomonas azotoformans ASS1 accelerates phytoremediation of soil metals under drought stress.

Science.gov (United States)

Ma, Ying; Rajkumar, Mani; Moreno, António; Zhang, Chang; Freitas, Helena

2017-10-01

This study evaluates the potential of serpentine endophytic bacterium to foster phytoremediation efficiency of Trifolium arvense grown on multi-metal (Cu, Zn and Ni) contaminated soils under drought stress. A drought resistant endophytic bacterial strain ASS1 isolated from the leaves of Alyssum serpyllifolium grown in serpentine soils was identified as Pseudomonas azotoformans based on biochemical tests and partial 16S rRNA gene sequencing. P. azotoformans ASS1 possessed abiotic stress resistance (heavy metals, drought, salinity, antibiotics and extreme temperature) and plant growth promoting (PGP) properties (phosphate solubilization, nitrogen fixation, production of 1-aminocyclopropane-1-carboxylate deaminase, siderophore and ammonia). Inoculation of T. arvense with ASS1 considerably increased the plant biomass and leaf relative water content in both roll towel assay and pot experiments in the absence and presence of drought stress (DS). In the pot experiments, ASS1 greatly enhanced chlorophyll content, catalase, peroxidase, superoxide dismutase activities, and proline content (only in the absence of drought) in plant leaves, whereas they decreased the concentrations of malondialdehyde. Irrespective of water stress, ASS1 significantly improved accumulation, total removal, bio-concentration factor and biological accumulation coefficient of metals (Cu, Zn and Ni), while decreased translocation factors of Cu. The effective colonization and survival in the rhizosphere and tissue interior assured improved plant growth and successful metal phytoremediation under DS. These results demonstrate the potential of serpentine endophytic bacterium ASS1 for protecting plants against abiotic stresses and helping plants to thrive in semiarid ecosystems and accelerate phytoremediation process in metal polluted soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

METAL COMPLEXES OF SALICYLHYDROXAMIC ACID AND 1,10 ...

African Journals Online (AJOL)

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Metal complexes which are formed in biological systems between a ligand and a metal ion are in dynamic ... In a continuation of our research work oriented towards studying the .... Antimicrobial activity techniques. Preparation of test samples.

Effect of candesartan on prevention (DIRECT-Prevent 1) and progression (DIRECT-Protect 1) of retinopathy in type 1 diabetes: randomised, placebo-controlled trials

DEFF Research Database (Denmark)

Chaturvedi, N.; Porta, M.; Klein, R.

2008-01-01

of retinopathy in type 1 diabetes. METHODS: Two randomised, double-blind, parallel-design, placebo-controlled trials were done in 309 centres worldwide. Participants with normotensive, normoalbuminuric type 1 diabetes without retinopathy were recruited to the DIRECT-Prevent 1 trial and those with existing...... retinopathy were recruited to DIRECT-Protect 1, and were assigned to candesartan 16 mg once a day or matching placebo. After 1 month, the dose was doubled to 32 mg. Investigators and participants were unaware of the treatment allocation status. The primary endpoints were incidence and progression......BACKGROUND: Results of previous studies suggest that renin-angiotensin system blockers might reduce the burden of diabetic retinopathy. We therefore designed the DIabetic REtinopathy Candesartan Trials (DIRECT) Programme to assess whether candesartan could reduce the incidence and progression...

Advances in Metallic Fuels for High Burnup and Actinide Transmutation

Energy Technology Data Exchange (ETDEWEB)

Hayes, S. L.; Harp, J. M.; Chichester, H. J. M.; Fielding, R. S.; Mariani, R. D.; Carmack, W. J.

2016-10-01

Research and development activities on metallic fuels in the US are focused on their potential use for actinide transmutation in future sodium fast reactors. As part of this application, there is a desire to demonstrate a multifold increase in burnup potential. A number of metallic fuel design innovations are under investigation with a view toward significantly increasing the burnup potential of metallic fuels, since higher discharge burnups equate to lower potential actinide losses during recycle. Promising innovations under investigation include: 1) lowering the fuel smeared density in order to accommodate the additional swelling expected as burnups increase, 2) utilizing an annular fuel geometry for better geometrical stability at low smeared densities, as well as the potential to eliminate the need for a sodium bond, and 3) minor alloy additions to immobilize lanthanide fission products inside the metallic fuel matrix and prevent their transport to the cladding resulting in fuel-cladding chemical interaction. This paper presents results from these efforts to advance metallic fuel technology in support of high burnup and actinide transmutation objectives. Highlights include examples of fabrication of low smeared density annular metallic fuels, experiments to identify alloy additions effective in immobilizing lanthanide fission products, and early postirradiation examinations of annular metallic fuels having low smeared densities and palladium additions for fission product immobilization.

EDTA-assisted phytoextraction of heavy metals by turfgrass from municipal solid waste compost using permeable barriers and associated potential leaching risk.

Science.gov (United States)

Zhao, Shulan; Lian, Fei; Duo, Lian

2011-01-01

A column experiment with horizontal permeable barriers was conducted to investigate phytoextraction of heavy metals by Lolium perenne L. from municipal solid waste compost following EDTA application, as well as to study the effects of L. perenne and permeable barriers on preventing metal from leaching. In columns with barriers, EDTA addition yielded maximum concentrations of Cu, Zn and Pb of 155, 541 and 33.5 mg kg(-1) in shoot, respectively. This led to 4.2, 2.1 and 7.4 times higher concentrations of Cu, Zn and Pb compared to treatment with no chelating agent, respectively. In treatments with 10 mmol kg(-1) EDTA, the barriers reduced leaching of Cu, Zn and Pb by approximately three times, respectively, resulting in leaching of total initial Cu, Zn and Pb by 27.3%, 25.2% and 28.8%, respectively, after four times' irrigation. These results indicate that L. perenne and permeable barriers are effective to reduce leaching of heavy metals and minimize the risk of contaminating groundwater in EDTA-enhanced phytoremediation. Thus these findings highlight that turfgrass and permeable barriers can effectively prevent metal leaching. Copyright © 2010 Elsevier Ltd. All rights reserved.

Hydrolysis of metal ions. Vol. 1 and 2

Energy Technology Data Exchange (ETDEWEB)

Brown, Paul L. [Geochem Australia, Kiama, NSW (Australia); Ekberg, Christian [Chalmers Univ. of Technology, Goeteborg (Sweden). Nuclear Chemistry/Industrial Materials Recycling

2016-07-01

Filling the need for a comprehensive treatment that covers the theory, methods and the different types of metal ion complexes with water (hydrolysis), this handbook and ready reference is authored by a nuclear chemist from academia and an industrial geochemist. The book includes both cation and anion complexes, and approaches the topic of metal ion hydrolysis by first covering the background, before proceeding with an overview of the dissociation of water and then all different metal-water hydrolysis complexes and compounds. A must-have for scientists in academia and industry working on this interdisciplinary topic.

Hydrogen-induced metallization on Ge(1 1 1) c(2 x 8)

International Nuclear Information System (INIS)

Razado, I.C.; Zhang, H.M.; Hansson, G.V.; Uhrberg, R.I.G.

2006-01-01

We have studied hydrogen adsorption on the Ge(1 1 1) c(2 x 8) surface using scanning tunneling microscopy (STM) and angle-resolved photoelectron spectroscopy (ARPES). We find that atomic hydrogen preferentially adsorbs on rest atom sites. The neighbouring adatoms appear higher in STM images, which clearly indicates a charge transfer from the rest atom states to the adatom states. The surface states near the Fermi-level have been followed by ARPES as function of H exposure. Initially, there is strong emission from the rest atom states but no emission at the Fermi-level which confirms the semiconducting character of the c(2 x 8) surface. With increasing H exposure a structure develops in the close vicinity of the Fermi-level. The energy position clearly indicates a metallic character of the H-adsorbed surface. Since the only change in the STM images is the increased brightness of the adatoms neighbouring a H-terminated rest atom, we identify the emission at the Fermi-level with these adatom states

DEVELOPING A CAPE-OPEN COMPLIANT METAL FINISHING FACILITY POLLUTION PREVENTION TOOL (CO-MFFP2T)

Science.gov (United States)

The USEPA is developing a Computer Aided Process Engineering (CAPE) software tool for the metal finishing industry that helps users design efficient metal finishing processes that are less polluting to the environment. Metal finishing process lines can be simulated and evaluated...

Predicting dietborne metal toxicity from metal influxes

Science.gov (United States)

Croteau, M.-N.; Luoma, S.N.

2009-01-01

Dietborne metal uptake prevails for many species in nature. However, the links between dietary metal exposure and toxicity are not well understood. Sources of uncertainty include the lack of suitable tracers to quantify exposure for metals such as copper, the difficulty to assess dietary processes such as food ingestion rate, and the complexity to link metal bioaccumulation and effects. We characterized dietborne copper, nickel, and cadmium influxes in a freshwater gastropod exposed to diatoms labeled with enriched stable metal isotopes. Metal influxes in Lymnaea stagnalis correlated linearly with dietborne metal concentrations over a range encompassing most environmental exposures. Dietary Cd and Ni uptake rate constants (kuf) were, respectively, 3.3 and 2.3 times higher than that for Cu. Detoxification rate constants (k detox) were similar among metals and appeared 100 times higher than efflux rate constants (ke). Extremely high Cu concentrations reduced feeding rates, causing the relationship between exposure and influx to deviate from linearity; i.e., Cu uptake rates leveled off between 1500 and 1800 nmol g-1 day-1. L. stagnalis rapidly takes up Cu, Cd, and Ni from food but detoxifies the accumulated metals, instead of reducing uptake or intensifying excretion. Above a threshold uptake rate, however, the detoxification capabilities of L. stagnalis are overwhelmed.

An alternative approach to the management of reactive metals: tolerant cementitious systems

International Nuclear Information System (INIS)

Swift, P.; Cox, J.; Wise, M.; McKinney, J.; Rhodes, C.

2015-01-01

In recent years research has focused on preventing or minimising corrosion of reactive metals to ensure long-term waste package integrity. An alternative approach to the encapsulation of reactive metals is being explored. The approach will identify a cementitious-based encapsulating material that will allow corrosion of reactive metals to occur in a controlled and predictable manner, rather than seeking to limit or prevent the corrosion, whilst retaining waste package integrity. A low strength grout will be developed that will be 'tolerant' to the expansive forces generated by the corrosion products of reactive metals. Novel cementitious systems (e.g. foamed cements, rubber composite cements, cenosphere composite cements, lime mortars, bentonite cements etc.) that may be tolerant to potentially expansive waste products, such as reactive metals will be considered and assessed in a series of small-scale preliminary trials (compressive strength, porosity, permeability, pore solution pH, etc.)

Electronic and magnetic properties of 1T-HfS{sub 2} by doping transition-metal atoms

Energy Technology Data Exchange (ETDEWEB)

Zhao, Xu, E-mail: zhaoxu@htu.cn [College of Physics and Electronic Engineering, Henan Normal University, Xinxiang, Henan 453007 (China); Wang, Tianxing; Wang, Guangtao [College of Physics and Electronic Engineering, Henan Normal University, Xinxiang, Henan 453007 (China); Dai, Xianqi [College of Physics and Electronic Engineering, Henan Normal University, Xinxiang, Henan 453007 (China); Department of Physics, Zhengzhou Normal University, Zhengzhou, Henan 450044 (China); Xia, Congxin [College of Physics and Electronic Engineering, Henan Normal University, Xinxiang, Henan 453007 (China); Yang, Lin [School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007 (China)

2016-10-15

Highlights: • Pristine 1T-HfS{sub 2} is a semiconductor with indirect gaps of 1.250 eV • Magnetism can be observed for V, Cr, Mn, Fe, Co, and Cu doping. • Strong p–d hybridization was found between TM 3d orbitals and S 3p orbitals. • V-doped 1T-HfS{sub 2} is ideal for spin injection. - Abstract: We explored the electronic and magnetic properties of 1T-HfS{sub 2} doped by transition metal (TM) atom using the first-principles calculation. We doped the transition metal atoms from the IIIB to VIB groups in nonmagnetic 1T-HfS{sub 2}. Numerical results show that the pristine 1T-HfS{sub 2} is a semiconductor with indirect gaps of 1.250 eV. Magnetism can be observed for V, Cr, Mn, Fe, Co, and Cu doping. The polarized charges mainly arise from the localized 3d electrons of the TM atom. The strong p–d hybridization was found between the 3d orbitals of TM and 3p orbitals of S. The substituted 1T-HfS{sub 2} can be a metal, semiconductor or half-metal. Analysis of the band structure and magnetic properties indicates that TM-doped HfS{sub 2} (TM = V, Fe, Cu) are promising systems to explore two-dimensional diluted magnetic semiconductors. The formation energy calculations also indicate that it is energetically favorable and relatively easier to incorporate transition metal atom into the HfS{sub 2} under S-rich experimental conditions. In contrast, V-doped HfS{sub 2} has relatively wide half-metallic gap and low formation energy. So V-doped 1T-HfS{sub 2} is ideal for spin injection, which is important for application in semiconductor spintronics.

40 CFR Table 1 to Subpart Uuu of... - Metal HAP Emission Limits for Catalytic Cracking Units

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Metal HAP Emission Limits for Catalytic Cracking Units 1 Table 1 to Subpart UUU of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION... Table 1 to Subpart UUU of Part 63—Metal HAP Emission Limits for Catalytic Cracking Units As stated in...

Phyto-metals screening of selected anti-diabetic herbs and infused concoctions

Directory of Open Access Journals (Sweden)

Olanrewaju O. Olujimi

2017-10-01

Conclusions: The study thus shows that the herbs and concoctions are safe from the heavy metals considered. However, right dosage of the anti-diabetic concoctions should always be considered to prevent possible chronic side effects from bio-accumulation of heavy metals.

Assessment of 1H NMR-based metabolomics analysis for normalization of urinary metals against creatinine.

Science.gov (United States)

Cassiède, Marc; Nair, Sindhu; Dueck, Meghan; Mino, James; McKay, Ryan; Mercier, Pascal; Quémerais, Bernadette; Lacy, Paige

2017-01-01

Proton nuclear magnetic resonance ( 1 H NMR, or NMR) spectroscopy and inductively coupled plasma-mass spectrometry (ICP-MS) are commonly used for metabolomics and metal analysis in urine samples. However, creatinine quantification by NMR for the purpose of normalization of urinary metals has not been validated. We assessed the validity of using NMR analysis for creatinine quantification in human urine samples in order to allow normalization of urinary metal concentrations. NMR and ICP-MS techniques were used to measure metabolite and metal concentrations in urine samples from 10 healthy subjects. For metabolite analysis, two magnetic field strengths (600 and 700MHz) were utilized. In addition, creatinine concentrations were determined by using the Jaffe method. Creatinine levels were strongly correlated (R 2 =0.99) between NMR and Jaffe methods. The NMR spectra were deconvoluted with a target database containing 151 metabolites that are present in urine. A total of 50 metabolites showed good correlation (R 2 =0.7-1.0) at 600 and 700MHz. Metal concentrations determined after NMR-measured creatinine normalization were comparable to previous reports. NMR analysis provided robust urinary creatinine quantification, and was sufficient for normalization of urinary metal concentrations. We found that NMR-measured creatinine-normalized urinary metal concentrations in our control subjects were similar to general population levels in Canada and the United Kingdom. Copyright © 2016 Elsevier B.V. All rights reserved.

Environmental Restoration Contractor Waste Minimization and Pollution Prevention Plan. Revision 1

International Nuclear Information System (INIS)

Lewis, R.A.

1996-03-01

This plan contains the Environmental Restoration Contractor (ERC) Waste Minimization and Pollution Prevention (WMin/P2) Program. The plan outlines the activities and schedules developed by the ERC to reduce the quantity and toxicity of waste dispositioned as a result of restoration and remediation activities. This plan satisfies US Department of Energy (DOE) requirements including the Pollution Prevention Awareness program required by DOE Order 5400.1 (DOE 1988). This plan is consistent with Executive Order 12856 and Secretary O'Leary's pollution prevention Policy Statement of December 27, 1994, which set US and DOE pollution prevention policies, respectively. It is also consistent with the DOE Pollution Prevention Crosscut Plan, 1994, which provides guidance in meeting the DOE goals in pollution prevention. The purpose of this plan is to aid ERC projects in meeting and documenting compliance with requirements for WMin/P2. This plan contains the objectives, strategy, and support activities of the ERC Team WMin/P2 program. The basic elements of the plan are pollution prevention goals, waste assessments of major waste streams, implementation of feasible waste minimization opportunities, and a process for reporting achievements. Wherever appropriate, the ERC will integrate the pollution prevention activities in this plan into regular program activities rather than establishing separate WMin/P2 activities. Moreover, wherever possible, existing documents, procedures, and activities will be used to meet WMin/P2 requirements

First-principles study of hydrogen dissociation and diffusion on transition metal-doped Mg(0 0 0 1) surfaces

International Nuclear Information System (INIS)

Wang, Zhiwen; Guo, Xinjun; Wu, Mingyi; Sun, Qiang; Jia, Yu

2014-01-01

First-principles calculations within the density functional theory (DFT) have been carried out to study hydrogen molecules dissociation and diffusion on clean and transition metals (TMs) doped Mg(0 0 0 1) surfaces following Pozzo et al. work. Firstly, the stability of Mg(0 0 0 1) surface doped with transition metals atom has been studied. The results showed that transition metals on the left of the table tend to substitute Mg in the second layer, while the other transition metals prefer to substitute Mg in the first layer. Secondly, we studied hydrogen molecules dissociation and diffusion on clean and Mg(0 0 0 1) surfaces which the transition metal atoms substituted both in the first layer and second layer. When transition metal atoms substitute in the first layer, the results agree with the Pozzo et al. result; when transition metal atoms substitute in the second layer, the results showed that the transition metals on the left of the periodic table impact on the dissociation barriers is less. However, for the transition metals (Mn, Fe, Co, Ni) on the right, there is a great impact on the barriers. The transition metals doped surfaces bind the dissociated H atoms loosely, making them easily diffused. The results further reveal that the Fe dopant on the Mg surface is the best choice for H 2 dissociation and hydrogen storage.

Sorption mechanisms of metals to graphene oxide

International Nuclear Information System (INIS)

Showalter, Allison R; Bunker, Bruce A; Duster, Thomas A; Szymanowski, Jennifer E S; Na, Chongzheng; Fein, Jeremy B

2016-01-01

Environmental toxic metal contamination remediation and prevention is an ongoing issue. Graphene oxide is highly sorptive for many heavy metals over a wide pH range under different ionic strength conditions. We present x-ray absorption fine structure (XAFS) spectroscopy results investigating the binding environment of Pb(II), Cd(II) and U(VI) ions onto multi-layered graphene oxide (MLGO). Analysis indicates that the dominant sorption mechanism of Pb to MLGO changes as a function of pH, with increasing inner sphere contribution as pH increases. In contrast, the sorption mechanism of Cd to MLGO remains constant under the studied pH range. This adsorption mechanism is an electrostatic attraction between the hydrated Cd +2 ion and the MLGO surface. The U(VI), present as the uranyl ion, changes only subtly as a function of pH and is bound to the surface via an inner sphere bond. Knowledge of the binding mechanism for each metal is necessary to help in optimizing environmental remediation or prevention in filtration systems. (paper)

Tuning metal–graphene interaction by non-metal intercalation: a case study of the graphene/oxygen/Ni (1 1 1) system

International Nuclear Information System (INIS)

Zhang, Wei-Bing; Chen, Chuan

2015-01-01

Epitaxial growth of graphene on transition metal surfaces has been proposed as one of the most promising methods for large-scale preparation of high-quality graphene. However, the presence of the substrate could significantly affect the intrinsic electronic structure of graphene and intercalation of metals is an established route for decoupling the graphene from the substrate. Taking a graphene/Ni(1 1 1) surface as an example, we suggest reactive oxygen as an effective intercalation element to recover the linear dispersion of graphene based on density functional theory calculation, in which vdW interactions are treated using the optB88-vdW functional. The possible intercalation configurations at different coverage are considered and the geometry and electronic structure are analyzed in detail. Our results indicate that the energy favorable structures change from top-fcc to bridge-top configuration after oxygen intercalation and the binding between the graphene and the O/Ni(1 1 1) substrate becomes stronger at high oxygen coverage even than pure Ni(1 1 1) substrate. Most interestingly, the electronic structure of pristine graphene is found to be almost restored, especially for the bridge-top configuration after oxygen intercalation, and the Dirac points move towards the high energy region relative to the Fermi level. A graphene/oxygen/Ni (1 1 1) system is thus suggested as a p-type doped strongly bound Dirac system. Detailed analysis using projected energy band and differential charge density indicates that the intercalated oxygen atoms react with the Ni (1 1 1) surface strongly, which not only blocks the strong interaction between Ni and graphene but also passivates oxygen 2p states. The intercalation mechanisms distinguished from the conventional metal intercalation will be useful to understand other complex intercalation systems. (paper)

Adoption of preventive measures during and after the 2009 influenza A (H1N1) virus pandemic peak in Spain.

Science.gov (United States)

Agüero, Fernando; Adell, Manel Nebot; Pérez Giménez, Anna; López Medina, María José; Garcia Continente, Xavier

2011-09-01

This study describes the preventive measures adopted by the Spanish population towards 2009 influenza A (H1N1) virus and their associated factors. An anonymous computer-assisted telephone interview survey was conducted in Spain in December 2009 and February 2010. Respondents were asked about their perceptions of influenza A (H1N1) virus and the preventive measures adopted. Factors associated with the adoption of preventive measures were assessed by logistic regression analyses. Out of 4892 households approached, 1627 valid responses were obtained (response rate of 33.3%). The most commonly adopted preventive measures were respiratory hygiene and hand washing. Factors independently associated with the adoption of the preventive measures recommended by the Spanish Ministry of Health were female gender, higher educational level, size of municipality of residence >50,000 inhabitants, high perceived susceptibility to infection, high perceived effectiveness of the measures and high perceived usefulness of the information provided by the government. The presence of school-aged children in household was associated with purchasing masks and hand sanitizer. In addition to demographic factors, modifiable factors such as personal beliefs and expectations play a role in the adoption of preventive measures. Copyright © 2011 Elsevier Inc. All rights reserved.

16 CFR 23.1 - Deception (general).

Science.gov (United States)

2010-01-01

... misrepresent the type, kind, grade, quality, quantity, metallic content, size, weight, cut, color, character..., distribution, or any other material aspect of an industry product. Note 1 to § 23.1: If, in the sale or..., the identity of the grading system used should be disclosed. Note 2 to § 23.1: To prevent deception...

Heavy Metals Induce Iron Deficiency Responses at Different Hierarchic and Regulatory Levels1[OPEN

Science.gov (United States)

2017-01-01

In plants, the excess of several heavy metals mimics iron (Fe) deficiency-induced chlorosis, indicating a disturbance in Fe homeostasis. To examine the level at which heavy metals interfere with Fe deficiency responses, we carried out an in-depth characterization of Fe-related physiological, regulatory, and morphological responses in Arabidopsis (Arabidopsis thaliana) exposed to heavy metals. Enhanced zinc (Zn) uptake closely mimicked Fe deficiency by leading to low chlorophyll but high ferric-chelate reductase activity and coumarin release. These responses were not caused by Zn-inhibited Fe uptake via IRON-REGULATED TRANSPORTER (IRT1). Instead, Zn simulated the transcriptional response of typical Fe-regulated genes, indicating that Zn affects Fe homeostasis at the level of Fe sensing. Excess supplies of cobalt and nickel altered root traits in a different way from Fe deficiency, inducing only transient Fe deficiency responses, which were characterized by a lack of induction of the ethylene pathway. Cadmium showed a rather inconsistent influence on Fe deficiency responses at multiple levels. By contrast, manganese evoked weak Fe deficiency responses in wild-type plants but strongly exacerbated chlorosis in irt1 plants, indicating that manganese antagonized Fe mainly at the level of transport. These results show that the investigated heavy metals modulate Fe deficiency responses at different hierarchic and regulatory levels and that the interaction of metals with physiological and morphological Fe deficiency responses is uncoupled. Thus, this study not only emphasizes the importance of assessing heavy metal toxicities at multiple levels but also provides a new perspective on how Fe deficiency contributes to the toxic action of individual heavy metals. PMID:28500270

Chronic Toxic Metal Exposure and Cardiovascular Disease: Mechanisms of Risk and Emerging Role of Chelation Therapy.

Science.gov (United States)

Aneni, Ehimen C; Escolar, Esteban; Lamas, Gervasio A

2016-12-01

Over the last few decades, there has been a growing body of epidemiologic evidence linking chronic toxic metal exposure to cardiovascular disease-related morbidity and mortality. The recent and unexpectedly positive findings from a randomized, double-blind, multicenter trial of metal chelation for the secondary prevention of atherosclerotic cardiovascular disease (Trial to Assess Chelation Therapy (TACT)) have focused the discussion on the role of chronic exposure to toxic metals in the development and propagation of cardiovascular disease and the role of toxic metal chelation therapy in the secondary prevention of cardiovascular disease. This review summarizes the most recent evidence linking chronic toxic metal exposure to cardiovascular disease and examines the findings of TACT.

Acrolein inhalation prevents VEGF-induced mobilization of Flk-1+/Sca-1+ cells in mice

Science.gov (United States)

Wheat, Laura A.; Haberzettl, Petra; Hellmann, Jason; Baba, Shahid P.; Bertke, Matthew; Lee, Jongmin; McCracken, James; O’Toole, Timothy E.; Bhatnagar, Aruni; Conklin, Daniel J.

2011-01-01

Objectives Acrolein is a toxic chemical present in tobacco, wood and coal smoke as well as automobile exhaust. Because exposure to these pollutants is associated with an increase in cardiovascular disease risk, we studied the effects of acrolein on Flk-1+/Sca-1+ cells that are involved in vascular repair. Methods and Results In adult male C57BL/6 mice, inhalation of acrolein (1ppm, 6h/day, 4 days or 5ppm for 2 or 6h) led to the formation of protein-acrolein adducts in the bone marrow and diminished levels of plasma NOx and circulating Flk-1+/Sca-1+ but not Sca-1+ only cells. Acrolein exposure increased the number of apoptotic Flk-1+/Sca1+ cells in circulation, and increased bone marrow-derived cells with endothelial characteristics (Dil-acLDL/UE-lectin and Flk-1+/Sca-1+) in culture. Deficits in the circulating levels of Flk-1+/Sca-1+ cells were reversed after 7 days of recovery in acrolein-free air. Exposure to acrolein blocked VEGF/AMD3100-stimulated mobilization of Flk-1+/Sca-1+ but not Sca-1+ only cells and prevented VEGF-induced phosphorylation of Akt and eNOS in the aorta. Conclusions Inhalation of acrolein increases apoptosis and suppresses the circulating levels of Flk-1+/Sca-1+ cells, while increasing these cells in the bone marrow and preventing their mobilization by VEGF. Exposure to acrolein-rich pollutants could impair vascular repair capacity. PMID:21527748

Spectra of globular clusters in the Sombrero galaxy: evidence for spectroscopic metallicity bimodality

Science.gov (United States)

Alves-Brito, Alan; Hau, George K. T.; Forbes, Duncan A.; Spitler, Lee R.; Strader, Jay; Brodie, Jean P.; Rhode, Katherine L.

2011-11-01

We present a large sample of over 200 integrated-light spectra of confirmed globular clusters (GCs) associated with the Sombrero (M104) galaxy taken with the Deep Imaging Multi-Object Spectrograph (DEIMOS) instrument on the Keck telescope. A significant fraction of the spectra have signal-to-noise ratio levels high enough to allow measurements of GC metallicities using the method of Brodie & Huchra. We find a distribution of spectroscopic metallicities in the range -2.2 < [Fe/H] < +0.1 that is bimodal, with peaks at [Fe/H]˜-1.4 and -0.6. Thus, the GC system of the Sombrero galaxy, like a few other galaxies now studied in detail, reveals a bimodal spectroscopic metallicity distribution supporting the long-held belief that colour bimodality reflects two metallicity subpopulations. This further suggests that the transformation from optical colour to metallicity for old stellar populations, such as GCs, is not strongly non-linear. We also explore the radial and magnitude distribution with metallicity for GC subpopulations but small number statistics prevent any clear trends in these distributions. Based on observations obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration.

Design and Implementation of 1-2 GHz Stepped Frequency GPR for Buried Metal Detection

Directory of Open Access Journals (Sweden)

Joko Suryana

2010-10-01

Full Text Available In this paper, we describe the design and realization steps of 1 - 2 GHz SFGPR (Stepped Frequency Ground Penetrating Radar transceiver for metal detection under the ground. Before using prototyped GPR for detecting the metal under the ground, several of calibration processes must be performed, namely phase calibration and monocycle pulse waveform calibration. After completing the calibrations, this prototyped GPR would be ready for detecting a  hidden object such as a metal plate 5 cm under the ground in our small test range size 25 cm x 75 cm x 10 cm. From the calibration and detection results, we concluded that the prototyped SFGPR passed the technical specifications of the design and could perform the metal detection under the ground with high SNR.

Structural and biophysical properties of metal-free pathogenic SOD1 mutants A4V and G93A

Energy Technology Data Exchange (ETDEWEB)

Galaleldeen, Ahmad; Strange, Richard W.; Whitson, Lisa J.; Antonyuk, Svetlana V.; Narayana, Narendra; Taylor, Alexander B.; Schuermann, Jonathan P.; Holloway, Stephen P.; Hasnain, S.Samar; Hart, P. John; (Texas-HSC); (Liverpool)

2010-07-19

Amyotrophic lateral sclerosis (ALS) is a fatal, progressive neurodegenerative disease characterized by the destruction of motor neurons in the spinal cord and brain. A subset of ALS cases are linked to dominant mutations in copper-zinc superoxide dismutase (SOD1). The pathogenic SOD1 variants A4V and G93A have been the foci of multiple studies aimed at understanding the molecular basis for SOD1-linked ALS. The A4V variant is responsible for the majority of familial ALS cases in North America, causing rapidly progressing paralysis once symptoms begin and the G93A SOD1 variant is overexpressed in often studied murine models of the disease. Here we report the three-dimensional structures of metal-free A4V and of metal-bound and metal-free G93A SOD1. In the metal-free structures, the metal-binding loop elements are observed to be severely disordered, suggesting that these variants may share mechanisms of aggregation proposed previously for other pathogenic SOD1 proteins.

Metal-ion complexes of functionalised 1,10-Phenanthrolines as hydrolytic synzymes

NARCIS (Netherlands)

Weijnen, J.G.J.

1993-01-01

In this thesis metal-ion complexes of functionalised 1,10-phenanthroline derivatives have been studied as model systems for hydrolytic metallo-enzymes. Amphiphilic metallo- complexes incorporated into micelles or vesicles and water-soluble complexes in pure aqueous buffer solutions, have

Electrochromic device containing metal oxide nanoparticles and ultraviolet blocking material

Science.gov (United States)

Garcia, Guillermo; Koo, Bonil; Gregoratto, Ivano; Basu, Sourav; Rosen, Evelyn; Holt, Jason; Thomsen, Scott

2017-10-17

An electrochromic device includes a nanostructured transition metal oxide bronze layer that includes one or more transition metal oxide and one or more dopant. The electrochromic device also includes nanoparticles containing one or more transparent conducting oxide (TCO), a solid state electrolyte, a counter electrode, and at least one protective layer to prevent degradation of the one or more nanostructured transition metal oxide bronze. The nanostructured transition metal oxide bronze selectively modulates transmittance of near-infrared (NIR) and visible radiation as a function of an applied voltage to the device.

The metal-enriched host of an energetic γ-ray burst at z ≈ 1.6

Science.gov (United States)

Krühler, T.; Fynbo, J. P. U.; Geier, S.; Hjorth, J.; Malesani, D.; Milvang-Jensen, B.; Levan, A. J.; Sparre, M.; Watson, D. J.; Zafar, T.

2012-10-01

Context. The star-forming nature of long γ-ray burst (GRB) host galaxies provides invaluable constraints on the progenitors of GRBs and might open a short-cut to the characteristics of typical star-forming galaxies throughout the history of the Universe. Due to the absence of near-infrared (NIR) spectroscopy, however, detailed investigations, specifically a determination of the gas-phase metallicity of gamma-ray burst hosts, was largely limited to redshifts z 1 GRB host in unprecedented detail and investigate the relation between GRB hosts and field galaxies. Methods: We availed of VLT/X-shooter optical/NIR spectroscopy to measure the metallicity, electron density, star-formation rate (SFR), and reddening of the host of GRB 080605. Specifically, we used different strong-line diagnostics to robustly measure the gas-phase metallicity within the interstellar medium (ISM) for the first time based on [N ii] at this redshift. Results: The host of the energetic (Eγ,iso ~ 2 × 1053 erg) GRB 080605 at z ~ 1.64 is a morphologically complex, vigorously star-forming galaxy with an Hα-derived SFR of 31-6+12 M⊙ yr-1. Its ISM is significantly enriched with metals. Specifically, [N ii]/Hα = 0.14 ± 0.02, which yields an oxygen abundance 12 + log (O/H) between 8.3 and 8.6 depending on the adopted strong-line calibrator. This corresponds to values in the range of 0.4 - 0.8 Z⊙. For its measured stellar mass M* = 8.0-1.6+1.3 × 109 M⊙ and SFR, this value is consistent with the fundamental metallicity relation defined by star-forming field galaxies. The absence of strong Lyα emission constrains the escape fraction of resonantly-scattered Lyα photons to fesc ≲ 0.08. Conclusions: Our observations provide a detailed picture of the conditions in the ISM of a highly star-forming galaxy with irregular morphology at z ~ 1.6. They include the first robust metallicity measurement based on [N ii] for a GRB host at z > 1 and directly illustrate that GRB hosts are not necessarily

Global strategies to prevent chronic diseases1

African Journals Online (AJOL)

Nicky

leading global causes of death and disability, are ... global strategies for the prevention and control of chronic ... Preventing Chronic Diseases: A Vital Investment, will ..... Millennium Development Goals for Health In Europe and Central Asia.

Salicylate prevents virus-induced type 1 diabetes in the BBDR rat.

Directory of Open Access Journals (Sweden)

Chaoxing Yang

Full Text Available Epidemiologic and clinical evidence suggests that virus infection plays an important role in human type 1 diabetes pathogenesis. We used the virus-inducible BioBreeding Diabetes Resistant (BBDR rat to investigate the ability of sodium salicylate, a non-steroidal anti-inflammatory drug (NSAID, to modulate development of type 1 diabetes. BBDR rats treated with Kilham rat virus (KRV and polyinosinic:polycytidylic acid (pIC, a TLR3 agonist develop diabetes at nearly 100% incidence by ~2 weeks. We found distinct temporal profiles of the proinflammatory serum cytokines, IL-1β, IL-6, IFN-γ, IL-12, and haptoglobin (an acute phase protein in KRV+pIC treated rats. Significant elevations of IL-1β and IL-12, coupled with sustained elevations of haptoglobin, were specific to KRV+pIC and not found in rats co-treated with pIC and H1, a non-diabetogenic virus. Salicylate administered concurrently with KRV+pIC inhibited the elevations in IL-1β, IL-6, IFN-γ and haptoglobin almost completely, and reduced IL-12 levels significantly. Salicylate prevented diabetes in a dose-dependent manner, and diabetes-free animals had no evidence of insulitis. Our data support an important role for innate immunity in virus-induced type 1 diabetes pathogenesis. The ability of salicylate to prevent diabetes in this robust animal model demonstrates its potential use to prevent or attenuate human autoimmune diabetes.

High-Pressure Thermodynamic Properties of f-electron Metals, Transition Metal Oxides, and Half-Metallic Magnets

International Nuclear Information System (INIS)

Richard T. Scalettar; Warren E. Pickett

2005-01-01

This project involves research into the thermodynamic properties of f-electron metals, transition metal oxides, and half-metallic magnets at high pressure. These materials are ones in which the changing importance of electron-electron interactions as the distance between atoms is varied can tune the system through phase transitions from localized to delocalized electrons, from screened to unscreened magnetic moments, and from normal metal to one in which only a single spin specie can conduct. Three main thrusts are being pursued: (1) Mott transitions in transition metal oxides, (2) magnetism in half-metallic compounds, and (3) large volume-collapse transitions in f-band metals

High-Pressure Thermodynamic Properties of f-electron Metals, Transition Metal Oxides, and Half-Metallic Magnets

Energy Technology Data Exchange (ETDEWEB)

Scalettar, Richard T.; Pickett, Warren E.

2004-07-01

This project involves research into the thermodynamic properties of f-electron metals, transition metal oxides, and half-metallic magnets at high pressure. These materials are ones in which the changing importance of electron-electron interactions as the distance between atoms is varied can tune the system through phase transitions from localized to delocalized electrons, from screened to unscreened magnetic moments, and from normal metal to one in which only a single spin specie can conduct. Three main thrusts are being pursued: (1) Mott transitions in transition metal oxides, (2) magnetism in half-metallic compounds, and (3) large volume-collapse transitions in f-band metals.

Alkali metal-refractory metal biphase electrode for AMTEC

Science.gov (United States)

Williams, Roger M. (Inventor); Bankston, Clyde P. (Inventor); Cole, Terry (Inventor); Khanna, Satish K. (Inventor); Jeffries-Nakamura, Barbara (Inventor); Wheeler, Bob L. (Inventor)

1989-01-01

An electrode having increased output with slower degradation is formed of a film applied to a beta-alumina solid electrolyte (BASE). The film comprises a refractory first metal M.sup.1 such as a platinum group metal, suitably platinum or rhodium, capable of forming a liquid or a strong surface adsorption phase with sodium at the operating temperature of an alkali metal thermoelectric converter (AMTEC) and a second refractory metal insoluble in sodium or the NaM.sup.1 liquid phase such as a Group IVB, VB or VIB metal, suitably tungsten, molybdenum, tantalum or niobium. The liquid phase or surface film provides fast transport through the electrode while the insoluble refractory metal provides a structural matrix for the electrode during operation. A trilayer structure that is stable and not subject to deadhesion comprises a first, thin layer of tungsten, an intermediate co-deposited layer of tungsten-platinum and a thin surface layer of platinum.

Cobalt-alloy implant debris induce HIF-1α hypoxia associated responses: a mechanism for metal-specific orthopedic implant failure.

Directory of Open Access Journals (Sweden)

Lauryn Samelko

Full Text Available The historical success of orthopedic implants has been recently tempered by unexpected pathologies and early failures of some types of Cobalt-Chromium-Molybdenum alloy containing artificial hip implants. Hypoxia-associated responses to Cobalt-alloy metal debris were suspected as mediating this untoward reactivity at least in part. Hypoxia Inducible Factor-1α is a major transcription factor involved in hypoxia, and is a potent coping mechanism for cells to rapidly respond to changing metabolic demands. We measured signature hypoxia associated responses (i.e. HIF-1α, VEGF and TNF-α to Cobalt-alloy implant debris both in vitro (using a human THP-1 macrophage cell line and primary human monocytes/macrophages and in vivo. HIF-1α in peri-implant tissues of failed metal-on-metal implants were compared to similar tissues from people with metal-on-polymer hip arthroplasties, immunohistochemically. Increasing concentrations of cobalt ions significantly up-regulated HIF-1α with a maximal response at 0.3 mM. Cobalt-alloy particles (1 um-diameter, 10 particles/cell induced significantly elevated HIF-1α, VEGF, TNF-α and ROS expression in human primary macrophages whereas Titanium-alloy particles did not. Elevated expression of HIF-1α was found in peri-implant tissues and synovial fluid of people with failing Metal-on-Metal hips (n = 5 compared to failed Metal-on-Polymer articulating hip arthroplasties (n = 10. This evidence suggests that Cobalt-alloy, more than other metal implant debris (e.g. Titanium alloy, can elicit hypoxia-like responses that if unchecked can lead to unusual peri-implant pathologies, such as lymphocyte infiltration, necrosis and excessive fibrous tissue growths.

[Research advances in heavy metals pollution ecology of diatom].

Science.gov (United States)

Ding, Teng-Da; Ni, Wan-Min; Zhang, Jian-Ying

2012-03-01

Diatom, due to its high sensitivity to environmental change, is one of the bio-indicators of aquatic ecosystem health, and some typical diatom species have been applied to indicate the heavy metals pollution of water body. With the focus on the surface water heavy metals pollution, this paper reviewed the research advances in the toxic effect of heavy metals pollution on diatom, biosorption and bioaccumulation of heavy metals by diatom, ecological adaptation mechanisms of diatom to heavy metals pollution, and roles of diatom as bio-indicator and in ecological restoration of heavy metals pollution. The growth tendency of diatom and the morphological change of frustule under heavy metals pollution as well as the differences in heavy metals biosorption and bioaccumulation by diatom, the ecological adaptation mechanisms of diatom on heavy metals surface complexation and ion exchange, and the roles of diatom as bio-indicator and in ecological restoration of heavy metals polluted water body were also discussed. This review could provide scientific evidences for the prevention of aquatic ecosystems heavy metals pollution and related early warning techniques.

Epidemiological Study on Metal Pollution of Ningbo in China

Directory of Open Access Journals (Sweden)

Zhou Li

2018-02-01

Full Text Available Background: In order to search for effective control and prevention measures, the status of metal pollution in Ningbo, China was investigated. Methods: Nine of the most common contaminating metals including lead (Pb, cadmium (Cd, copper (Cu, iron (Fe, manganese (Mn, chromium (Cr, nickel (Ni, zinc (Zn, and mercury (Hg in samples of vegetables, rice, soil, irrigation water, and human hair were detected using inductively coupled plasma-mass spectrometry (ICP-MS. Three different districts including industrial, suburban and rural areas in Ningbo were studied through a stratified random sample method. Results: (1 Among all of the detected vegetable samples, Cd exceeded the standard limit rates in industrial, suburban and rural areas as high as 43.9%, 27.5% and 5.0%, respectively; indicating the severity of Cd pollution in Ningbo. (2 The pollution index (PI of Cd and Zn in soil (1.069, 1.584, respectively suggests that soil is slightly polluted by Cd and Zn. Among all samples, metal contamination levels in soil were all relatively high. (3 A positive correlation was found between the concentrations of Pb, Cd and Cu in vegetables and soil; Pb, Cu, Cr and Ni in vegetables and irrigation water, as well as, Cu and Ni in rice and irrigation water; and, (4 Higher Pb and Cd concentrations were found in student scalp hair in both industrial and suburban areas compared to rural areas. (5 Hg and Pb that are found in human scalp hair may be more easily absorbed from food than any of the other metals. Conclusions: In general, certain harmful metal pollutions were detected in both industrial and suburban areas of Ningbo in China.

[Mapping Critical Loads of Heavy Metals for Soil Based on Different Environmental Effects].

Science.gov (United States)

Shi, Ya-xing; Wu, Shao-hua; Zhou, Sheng-lu; Wang, Chun-hui; Chen, Hao

2015-12-01

China's rapid development of industrialization and urbanization causes the growing problem of heavy metal pollution of soil, threatening environment and human health. Therefore, prevention and management of heavy metal pollution become particularly important. Critical loads of heavy metals are an important management tool that can be utilized to prevent the occurrence of heavy metal pollution. Our study was based on three cases: status balance, water environmental effects and health risks. We used the steady-state mass balance equation to calculate the critical loads of Cd, Cu, Pb, Zn at different effect levels and analyze the values and spatial variation of critical loads. In addition, we used the annual input fluxes of heavy metals of the agro-ecosystem in the Yangtze River delta and China to estimate the proportion of area with exceedance of critical loads. The results demonstrated that the critical load value of Cd was the minimum, and the values of Cu and Zn were lager. There were spatial differences among the critical loads of four elements in the study area, lower critical loads areas mainly occurred in woodland and high value areas distributed in the east and southwest of the study area, while median values and the medium high areas mainly occurred in farmland. Comparing the input fluxes of heavy metals, we found that Pb and Zn in more than 90% of the area exceeded the critical loads under different environmental effects in the study area. The critical load exceedance of Cd mainly occurred under the status balance and the water environmental effect, while Cu under the status balance and water environmental effect with a higher proportion of exceeded areas. Critical loads of heavy metals at different effect levels in this study could serve as a reference from effective control of the emissions of heavy metals and to prevent the occurrence of heavy metal pollution.

THE METALLICITY DEPENDENCE OF THE CO {yields} H{sub 2} CONVERSION FACTOR IN z {>=} 1 STAR-FORMING GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Genzel, R.; Tacconi, L. J.; Schreiber, N. M. Foerster; Gracia-Carpio, J.; Lutz, D.; Saintonge, A. [Max-Planck-Institut fuer extraterrestrische Physik (MPE), Giessenbachstr. 1, 85748 Garching (Germany); Combes, F. [Observatoire de Paris, LERMA, CNRS, 61 Av. de l' Observatoire, F-75014 Paris (France); Bolatto, A. [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Neri, R.; Cox, P. [IRAM, 300 Rue de la Piscine, 38406 St. Martin d' Heres, Grenoble (France); Sternberg, A. [Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel); Cooper, M. C. [Department of Physics and Astronomy, Frederick Reines Hall, University of California, Irvine, CA 92697-4575 (United States); Bouche, N. [Department of Physics, University of California, Santa Barbara, Broida Hall, Santa Barbara, CA 93106 (United States); Bournaud, F. [Service d' Astrophysique, DAPNIA, CEA/Saclay, F-91191 Gif-sur-Yvette Cedex (France); Burkert, A. [Universitaetssternwarte der Ludwig-Maximiliansuniversitaet, Scheinerstr. 1, D-81679 Muenchen (Germany); Comerford, J. [Department of Astronomy and McDonald Observatory, 1 University Station, C1402 Austin, TX 78712-0259 (United States); Davis, M.; Newman, S. [Department of Astronomy, Campbell Hall, University of California, Berkeley, CA 94720 (United States); Garcia-Burillo, S. [Observatorio Astronomico Nacional-OAN, Apartado 1143, 28800 Alcala de Henares- Madrid (Spain); Naab, T., E-mail: genzel@mpe.mpg.de, E-mail: linda@mpe.mpg.de [Max-Planck Institut fuer Astrophysik (MPA), Karl Schwarzschildstrasse 1, D-85748 Garching (Germany); and others

2012-02-10

We use the first systematic samples of CO millimeter emission in z {>=} 1 'main-sequence' star-forming galaxies to study the metallicity dependence of the conversion factor {alpha}{sub CO,} from CO line luminosity to molecular gas mass. The molecular gas depletion rate inferred from the ratio of the star formation rate (SFR) to CO luminosity, is {approx}1 Gyr{sup -1} for near-solar metallicity galaxies with stellar masses above M{sub S} {approx} 10{sup 11} M{sub Sun }. In this regime, the depletion rate does not vary more than a factor of two to three as a function of molecular gas surface density or redshift between z {approx} 0 and 2. Below M{sub S} the depletion rate increases rapidly with decreasing metallicity. We argue that this trend is not caused by starburst events, by changes in the physical parameters of the molecular clouds, or by the impact of the fundamental-metallicity-SFR-stellar mass relation. A more probable explanation is that the conversion factor is metallicity dependent and that star formation can occur in 'CO-dark' gas. The trend is also expected theoretically from the effect of enhanced photodissociation of CO by ultraviolet radiation at low metallicity. From the available z {approx} 0 and z {approx} 1-3 samples we constrain the slope of the log({alpha}{sub CO})-log (metallicity) relation to range between -1 and -2, fairly insensitive to the assumed slope of the gas-SFR relation. Because of the lower metallicities near the peak of the galaxy formation activity at z {approx} 1-2 compared to z {approx} 0, we suggest that molecular gas masses estimated from CO luminosities have to be substantially corrected upward for galaxies below M{sub S}.

Economical characteristics of base types of minerals. 1. Metallic minerals

International Nuclear Information System (INIS)

Khasanov, A.Kh.

1990-01-01

Metallic minerals is raw materials base of black and colour metallurgy. In this article of book author describes the group of black metals (iron, manganese, chromium), group of tempers (titanium, vanadium, nickel, cobalt, molybdenum, tungsten), colour metals (copper, lead, zinc, aluminium, tin, mercury, antimony, bismuth) and etc.

Final results of the XR2-1 BWR metallic melt relocation experiment

International Nuclear Information System (INIS)

Gauntt, R.O.; Humphries, L.L.

1997-08-01

This report documents the final results of the XR2-1 boiling water reactor (BWR) metallic melt relocation experiment, conducted at Sandia National Laboratories for the U.S. Nuclear Regulatory Commission. The objective of this experiment was to investigate the material relocation processes and relocation pathways in a dry BWR core following a severe nuclear reactor accident such as an unrecovered station blackout accident. The imposed test conditions (initial thermal state and the melt generation rates) simulated the conditions for the postulated accident scenario and the prototypic design of the lower core test section (in composition and in geometry) ensured that thermal masses and physical flow barriers were modeled adequately. The experiment has shown that, under dry core conditions, the metallic core materials that melt and drain from the upper core regions can drain from the core region entirely without formation of robust coherent blockages in the lower core. Temporary blockages that suspended pools of molten metal later melted, allowing the metals to continue draining downward. The test facility and instrumentation are described in detail. The test progression and results are presented and compared to MERIS code analyses. 6 refs., 55 figs., 4 tabs

Selective removal of heavy metals from metal-bearing wastewater in a cascade line reactor.

Science.gov (United States)

Pavlović, Jelena; Stopić, Srećko; Friedrich, Bernd; Kamberović, Zeljko

2007-11-01

This paper is a part of the research work on 'Integrated treatment of industrial wastes towards prevention of regional water resources contamination - INTREAT' the project. It addresses the environmental pollution problems associated with solid and liquid waste/effluents produced by sulfide ore mining and metallurgical activities in the Copper Mining and Smelting Complex Bor (RTB-BOR), Serbia. However, since the minimum solubility for the different metals usually found in the polluted water occurs at different pH values and the hydroxide precipitates are amphoteric in nature, selective removal of mixed metals could be achieved as the multiple stage precipitation. For this reason, acid mine water had to be treated in multiple stages in a continuous precipitation system-cascade line reactor. All experiments were performed using synthetic metal-bearing effluent with chemical a composition similar to the effluent from open pit, Copper Mining and Smelting Complex Bor (RTB-BOR). That effluent is characterized by low pH (1.78) due to the content of sulfuric acid and heavy metals, such as Cu, Fe, Ni, Mn, Zn with concentrations of 76.680, 26.130, 0.113, 11.490, 1.020 mg/dm3, respectively. The cascade line reactor is equipped with the following components: for feeding of effluents, for injection of the precipitation agent, for pH measurements and control, and for removal of the process gases. The precipitation agent was 1M NaOH. In each of the three reactors, a changing of pH and temperature was observed. In order to verify. efficiency of heavy metals removal, chemical analyses of samples taken at different pH was done using AES-ICP. Consumption of NaOH in reactors was 370 cm3, 40 cm3 and 80 cm3, respectively. Total time of the experiment was 4 h including feeding of the first reactor. The time necessary to achieve the defined pH value was 25 min for the first reactor and 13 min for both second and third reactors. Taking into account the complete process in the cascade line

Prevention of atherosclerosis by specific AT1-receptor blockade with candesartan cilexetil

Directory of Open Access Journals (Sweden)

Vasilios Papademetriou

2001-03-01

Full Text Available Several studies indicate that blockade of the renin-angiotensin-aldosterone system (RAAS can prevent atherosclerosis and vascular events, but the precise mechanisms involved are still unclear. In this study, we investigated the effect of the AT 1-receptor blocker, candesartan, in the prevention of atherosclerosis in Watanabe heritable hyperlipidaemic (WHHL rabbits and also the effect of AT1-receptor blockade in the uptake of oxidised LDL by macrophage cell cultures. In the first set of experiments, 12 WHHL rabbits were randomly assigned to three groups: placebo, atenolol 5 mg/kg daily or candesartan 2 mg/kg daily for six months. Compared with controls and atenolol-treated rabbits, candesartan treatment resulted in a significant 50—60% reduction of atherosclerotic plaque formation and a 66% reduction in cholesterol accumulation in the thoracic aorta.Studies in macrophage cultures indicated that candesartan prevented uptake of oxidised LDL-(oxLDL-cholesterol by cultured macrophages. Candesartan inhibited the uptake of oxLDL in a dose-dependent manner, reaching a maximum inhibition of 70% at concentrations of 5.6 µg/ml. Further studies in other animal models and well-designed trials in humans are warranted to further explore the role of AT1-receptor blockade in the prevention of atherosclerosis.

Container for liquid metal

International Nuclear Information System (INIS)

Abe, Yoshihito; Imazu, Takayuki; Ueda, Sabuo; Ueya, Katsumi.

1980-01-01

Purpose: To arrange a vapor trapping member of a specific structure at the inlet part of a cylindrical gap formed by the inner peripheral surface of the circular opening of a container and the outer peripheral surface of a rotary plug thereby to prevent ingress of vapor in the upper part of the cylindrical gap for a long period of time. Constitution: A sealing material receiving tray is fitted to the container side of the inlet part of a cylindrical gap, and a partition plate is fitted to the rotary plug side. The tray is filled with a sealing material consisting of a large number of steel balls, mesh wire gages and the like, and the partition plate is placed in the tray thereby to carry out sealing of the container. Liquid metal vapor evaporating from the liquid level of the liquid metal adheres to the sealing material to fill the gap, and therefore ingress of vapor to the upper part of the cylindrical gap is prevented, and there is no possibility of causing seal cutting due to the use for a long period. (Sekiya, K.)

Synthesis, Characterization and Antibacterial Activity of Novel 1,3-Diethyl-1,3-bis(4-nitrophenylurea and Its Metal(II Complexes

Directory of Open Access Journals (Sweden)

Hoda Pasdar

2017-12-01

Full Text Available A bioactive ligand and its dinuclear metal(II complexes were synthesized and characterized by Fourier-transform infrared spectroscopy (FT-IR, ultraviolet-visible (UV-Visible, nuclear magnetic resonance (1H-NMR, mass spectroscopy and molar conductance measurements. The ligand has been crystalized in the monoclinic system with a P21/c space group. The biological activities of metal complexes were evaluated using disc diffusion and broth dilution methods. In vitro antibacterial activities of the ligand and their metal complexes were examined against two Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus and two Gram-negative bacteria (Escherichia coli and Serratia marcescens and compared to the standard drugs. It was found that metal complexes displayed much higher antibacterial activities and better inhibitory effects than that of the ligand and standard drugs. Among these complexes, the compound having Zn-metal showed greater antibacterial activity against all four tested bacteria and was more effective against Serratia marcescens with the zone inhibition diameter of 26 mm and MIC value of 31.25 µg/mL.

Effect of carbon ion implantation on the tribology of metal-on-metal bearings for artificial joints.

Science.gov (United States)

Koseki, Hironobu; Tomita, Masato; Yonekura, Akihiko; Higuchi, Takashi; Sunagawa, Sinya; Baba, Koumei; Osaki, Makoto

2017-01-01

Metal-on-metal (MoM) bearings have become popular due to a major advantage over metal-on-polymer bearings for total hip arthroplasty in that the larger femoral head and hydrodynamic lubrication of the former reduce the rate of wear. However, concerns remain regarding adverse reactions to metal debris including metallosis caused by metal wear generated at the taper-head interface and another modular junction. Our group has hypothesized that carbon ion implantation (CII) may improve metal wear properties. The purpose of this study was to investigate the wear properties and friction coefficients of CII surfaces with an aim to ultimately apply these surfaces to MoM bearings in artificial joints. CII was applied to cobalt-chromium-molybdenum (Co-Cr-Mo) alloy substrates by plasma source ion implantation. The substrates were characterized using scanning electron microscopy and a 3D measuring laser microscope. Sliding contact tests were performed with a simple geometry pin-on-plate wear tester at a load of 2.5 N, a calculated contact pressure of 38.5 MPa (max: 57.8 MPa), a reciprocating velocity of 30 mm/s, a stroke length of 60 mm, and a reciprocating cycle count of 172,800 cycles. The surfaces of the CII substrates were generally featureless with a smooth surface topography at the same level as untreated Co-Cr-Mo alloy. Compared to the untreated Co-Cr-Mo alloy, the CII-treated bearings had lower friction coefficients, higher resistance to catastrophic damage, and prevented the adhesion of wear debris. The results of this study suggest that the CII surface stabilizes the wear status due to the low friction coefficient and low infiltration of partner materials, and these properties also prevent the adhesion of wear debris and inhibit excessive wear. Carbon is considered to be biologically inert; therefore, CII is anticipated to be applicable to the bearing surfaces of MoM prostheses.

Determination of preventive behaviors for pandemic influenza A/H1N1 based on protection motivation theory among female high school students in Isfahan, Iran

OpenAIRE

Sharifirad, Gholamreza; Yarmohammadi, Parastoo; Sharifabad, Mohammad Ali Morowati; Rahaei, Zohreh

2014-01-01

Introduction: Influenza A/H1N1 pandemic has recently threatened the health of world's population more than ever. Non-pharmaceutical measures are important to prevent the spread of influenza A/H1N1 and to prevent a pandemic. Effective influenza pandemic management requires understanding of the factors influencing preventive behavioral. This study reports on predictors of students’ preventive behaviors for pandemic influenza A/H1N1 using variables based on the protection motivation theory (PMT)...

Validation of ion chromatography for the determination of transition metal ions along with alkali, alkaline earth metal elements for uranium oxide fuel

International Nuclear Information System (INIS)

Kelkar, Anoop; Prakash, Amrit; Afzal, Mohd.; Panakkal, J.P.

2009-02-01

The present report describes the use of Ion chromatography (IC) methods with spectrophotometric and direct conductivity detection for the determination of transition metal elements and alkali alkaline earth metal ions in UO 2 pellets. Transmet analytical column and Metrosep- cation 1-2 column were used for the separation of transition metal elements and alkali and alkaline earth metal elements respectively. Oxalic acid and mixture of pyridine 2,6-dicarboxylic acid (PDCA), Na 2 SO 4 and NaCl were used as mobile phase for the separation of transition metal ions and monitored after post - column reaction with 4,2-pyridylazo resorcinol (PAR) at 520nm spectrophotometrically. In the determination of alkali and alkaline earth metal ions the interference of transition metals are removed by complexing them with PDCA. Mixture of tartaric acid and PDCA employed in the separation of alkali and alkaline earth metal ions and monitored on direct conductivity detector. Mobile phase composition was optimised for the base line separation. Calibration plots of Fe 3+ , Cu 2+ , Ni 2+ , Co 2+ , Cd 2+ , Mn 2+ , Li + , Na + , K + , Mg 2+ , Ca 2+ and Sr 2+ were linear over a wide dynamic range with regression coefficient better than 0.999. Detection limit of above ions were between 5-30ppb. To prevent the overloading of the cation exchange column, uranium matrix was removed from UO 2 sample by solvent extraction with 30% TBP - TOPO/CCl 4 . Ten sintered UO2 pellets of same lot were analysed and R.S.D. ±10% was obtained. These methods were validated by analysis of ILCE standards of UO 2 . (author)

Nanoporous metal-carbon composite

Science.gov (United States)

Worsley, Marcus A.; Satcher, Joe; Kucheyev, Sergei; Charnvanichborikarn, Supakit; Colvin, Jeffrey; Felter, Thomas; Kim, Sangil; Merrill, Matthew; Orme, Christine

2017-12-19

Described here is a metal-carbon composite, comprising (a) a porous three-dimensional scaffold comprising one or more of carbon nanotubes, graphene and graphene oxide, and (b) metal nanoparticles disposed on said porous scaffold, wherein the metal-carbon composite has a density of 1 g/cm.sup.3 or less, and wherein the metal nanoparticles account for 1 wt. % or more of the metal-carbon composite. Also described are methods for making the metal-carbon composite.

Materials damaging and rupture - Volumes 1-2. General remarks, metallic materials. Non-metallic materials and biomaterials, assemblies and industrial problems

International Nuclear Information System (INIS)

Clavel, M.; Bompard, P.

2009-01-01

The rupture and damaging of materials and structures is almost always and unwanted events which may have catastrophic consequences. Even if the mechanical failure causes can often be analyzed using a thorough knowledge of materials behaviour, the forecasting and prevention of failures remain difficult. While the macroscopic mechanical behaviour is often the result of average effects at the structure or microstructure scale, the damage is very often the result of the combination of load peaks, of localization effects and of microstructure defects. This book, presented in two volumes, takes stock of the state-of-the-art of the knowledge gained in the understanding and modelling of rupture and damaging phenomena of materials and structure, mostly of metallic type. It gives an outline of the available knowledge for other classes of materials (ceramics, biomaterials, geo-materials..) and for different types of applications (aeronautics, nuclear industry). Finally, it examines the delicate problem, but very important in practice, of the behaviour of assemblies. Content: Vol.1 - physical mechanisms of materials damaging and rupture; rupture mechanics; cyclic plasticity and fatigue crack growth; fatigue crack propagation; environment-induced cracking; contacts and surfaces. Vol.2 - glasses and ceramics; natural environments: soils and rocks; mechanical behaviour of biological solid materials: the human bone; contribution of simulation to the understanding of rupture mechanisms; assemblies damaging and rupture; industrial cases (behaviour of PWR pressure vessel steels, and thermal and mechanical stresses in turbojet engines). (J.S.)

CVD tungsten metallization and electron beam lithography for fabricating submicron interconnects for advanced ULSI

International Nuclear Information System (INIS)

Wilson, S.R.; Mattox, R.J.

1988-01-01

CVD W (0.45μm thick) and CVD W (0.25μm thick) strapped by Al (0.5μm thick) have been used as metal 1 systems. Electrical and physical data are presented from experiments exploring the effects of processing issues with both e-beam and stepper lithography as well as dry etch chemistry on both metal systems. The special issues encountered with the thick tungsten processing were: (i) Significant e-beam proximity related problems as compared to the sandwich metal layers. The resultant e-beam proximity problem contributed to a high level of metal bridging and poor CD control. (ii) Multiple etch related problems due to mask failure and a lack of etch selectivity. The multilevel masks utilized, consisting of photoresist and plasma enhanced oxide (PEO), failed due to the poor etch selectivity. Poor etch selectivity with respect to the underlying oxide was also observed. These issues were addressed with thicker organic and PEO mask layers as well as changes in etch chemistry. These thick layers were successful in preventing the loss of the mask during etch., but caused problems in the e-beam CD control and did not prevent the degradation of the underlying glass. A higher selectivity etch was developed which greatly reduced the underlying dielectric damage and also allowed the use of the thinner organic and PEO hardmask layers without mask failure

Design technology co-optimization for 14/10nm metal1 double patterning layer

Science.gov (United States)

Duan, Yingli; Su, Xiaojing; Chen, Ying; Su, Yajuan; Shao, Feng; Zhang, Recco; Lei, Junjiang; Wei, Yayi

2016-03-01

Design and technology co-optimization (DTCO) can satisfy the needs of the design, generate robust design rule, and avoid unfriendly patterns at the early stage of design to ensure a high level of manufacturability of the product by the technical capability of the present process. The DTCO methodology in this paper includes design rule translation, layout analysis, model validation, hotspots classification and design rule optimization mainly. The correlation of the DTCO and double patterning (DPT) can optimize the related design rule and generate friendlier layout which meets the requirement of the 14/10nm technology node. The experiment demonstrates the methodology of DPT-compliant DTCO which is applied to a metal1 layer from the 14/10nm node. The DTCO workflow proposed in our job is an efficient solution for optimizing the design rules for 14/10 nm tech node Metal1 layer. And the paper also discussed and did the verification about how to tune the design rule of the U-shape and L-shape structures in a DPT-aware metal layer.

Enrichment and assessment of the health risks posed by heavy metals in PM1 in Changji, Xinjiang, China.

Science.gov (United States)

Liu, Yu Y; Shen, Ya X; Liu, Cheng; Liu, Hao F

2017-04-16

The present study aims to investigate the influence of human activity on heavy metals in a typical arid urban area of China and assess human health risks posed by heavy metals in PM 1 (particles <1.0 μm in diameter) for different people. In this paper, Changji (Xinjiang, China) was selected as the study area, and samples were collected from March 2014 to March 2015. A total 14 elements in PM 1 were quantified using ICP-MS. An enrichment factor (EF) was used to assess the influence of human activity on the contamination of these metals. The results indicated that Mn was not enriched; Co, Cu, Cr, Ni, Tl, and V were slightly enriched; Mo, Pb, and Sb were moderately enriched; and Ag, As, and Cd were strongly enriched. To assess the health risks associated with inhaling PM 1 , the risk assessment code and loss in life expectancy based on the individual metals were calculated. The results showed that the elements Ag, Cu, Mo, Pb, Sb, Tl, and V in PM 1 posed low levels of non-carcinogenic risks, but these metals may still pose risks to certain susceptible populations. In addition, the results also showed that As, Co, and Cr posed an appreciable carcinogenic risk, while Cd and Ni posed low levels of carcinogenic risk. The total predicted loss of life expectancy caused by the three metals As, Co, and Ni was 63.67 d for the elderly, 30.95 d for adult males, 26.62 d for adult females, and 48.22 d for children. Therefore, the safety of the elderly and children exposed to PM 1 should be given more attention than the safety of adults. The results from this study demonstrate that the health risks posed by heavy metals in PM 1 in Changji, Xinjiang, China should be examined.

Some characteristics of metal migration in or on the surface of insulators

International Nuclear Information System (INIS)

Shields, R.B.

1978-03-01

This report reviews the migration of metals, principally silver, in or on the surface of insulating materials, by electrolytic processes. These processes are described for various metals, insulating materials and physical conditions, with numerous examples from the literature. While it is concluded that the only sure way to prevent degradation of insulation due to metal migration is to avoid the use of migration-prone metals, some other measures are mentioned which have been reported to reduce the extent of the growth. (author)

Nickel exposure from keys: alternatives for protection and prevention.

Science.gov (United States)

Hamann, Dathan; Scheman, Andrew J; Jacob, Sharon E

2013-01-01

Keys are an important exposure source of metal allergens to consumers and confer a significant problem for nickel-allergic individuals because of repeated daily use. The aims of this study were to investigate the frequency of nickel and cobalt release in keys and to consider the effectiveness of coatings for preventing metallic allergen release from common metal allergen-releasing keys. Keys from a variety of common stores were nickel and cobalt spot tested. Nickel-releasing keys were coated with enamel sprays, subjected to a use test, and retested to assess for metal allergen release. Of 55 tested keys, 80% showed a strong positive result to the nickel spot test. None of the tested keys exhibited cobalt release. No keys initially released nickel after enamel coatings. Key coatings chipped at the portion inserted into a lock after 30 insertions, and keys were found to release nickel. The handle of the key was not found to release nickel after 60 insertions. Nickel release from keys is very common; nickel-allergic consumers should consider purchasing keys that do not release nickel (eg, brass, anodized). Enamel coating may be useful in protecting nickel-sensitive individuals from their keys but cannot consistently prevent nickel-release from portions used frequently.

Recent progress in immune-based interventions to prevent HIV-1 transmission to children.

Science.gov (United States)

Voronin, Yegor; Jani, Ilesh; Graham, Barney S; Cunningham, Coleen K; Mofenson, Lynne M; Musoke, Philippa M; Permar, Sallie R; Scarlatti, Gabriella

2017-12-01

Globally, 150,000 new paediatric human immunodeficiency virus type 1 (HIV-1) infections occurred in 2015. There remain complex challenges to the global elimination of paediatric HIV-1 infection. Thus, for the global community to achieve elimination of new paediatric HIV-1 infections, innovative approaches need to be explored. Immune-based approaches to prevention of mother-to-child transmission (MTCT) may help fill some of the remaining gaps and provide new opportunities to achieve an AIDS-free generation. Immune-based interventions to prevent MTCT of HIV-1 may include paediatric HIV vaccines and passive immunization approaches. Recent discoveries providing evidence of robust immune responses to HIV in infants open new and exciting prospects for paediatric HIV vaccines. Moreover, successful vaccination of infants has a different set of requirements than vaccination of adults and may be easier to achieve. Proof-of-concept has been established over the last two decades that passively administered HIV-1 Env-specific monoclonal antibody (mAbs) can prevent chimeric simian human immunodeficiency virus (SHIV) transmission to newborn nonhuman primates. There has been tremendous progress in isolating and characterizing broadly neutralizing antibodies to HIV, and clinical testing of these antibodies for treatment and prevention in both infants and adults is a major effort in the field. Immune-based interventions need to be actively explored as they can provide critically important tools to address persistent challenges in MTCT prevention. It is a pivotal time for the field with active discussions on the best strategy to further reduce HIV infection of infants and accomplish the World Health Organization Fast-Track 2030 goals to eliminate new paediatric HIV infections. © 2017 The Authors. Journal of the International AIDS Society published by John Wiley & sons Ltd on behalf of the International AIDS Society.

Heavy Metals in Agricultural Soils in Nigeria: A Review

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J. J. Musa

2017-10-01

Full Text Available This review paper presents the health risks of heavy metals such as: lead (Pb, chromium (Cr, zinc (Zn, cadmium (Cd, copper (Cu, mercury (Hg, nickel (Ni and arsenic (As etc contamination in soils. The review reveals the major sources of these metals which are urban and industrial effluents, deterioration of sewage pipe, treatment water works, sewage sludge, fertilizers and pesticides. It also reveals the adopted standard for drinking water (maximum tolerable limit by FAO, JECFA and WHO which are as follows: 0.05mg/L, 0.05mg/L, 1.5mg/L, 0.001mg/L, 0.02mg/L, 15mg/L, 0.3mg/L, 0.5mg/L, 0.01mg/L, 0.05mg/L and 0.05mg/L for Pb, Cr, Cu, Hg, Ni, Zn, Fe, Mn, Se, As and Cd respectively. The accumulation of heavy metals in agricultural soils is of increasing concern because of food safety issues, potential health risks such as neurological disorder, cancer, kidney damage, fragile bone etc and their detrimental effects on soil ecosystem. However, the regular monitoring of levels of these metals from dump sites, effluents and sewages in soil and drinking water is essential to prevent excessive buildup of these metals thereby increasing toxicity and elevating the public health risk.

Blood metals concentration in type 1 and type 2 diabetics.

Science.gov (United States)

Forte, Giovanni; Bocca, Beatrice; Peruzzu, Angela; Tolu, Francesco; Asara, Yolande; Farace, Cristiano; Oggiano, Riccardo; Madeddu, Roberto

2013-12-01

Mechanisms for the onset of diabetes and the development of diabetic complications remain under extensive investigations. One of these mechanisms is abnormal homeostasis of metals, as either deficiency or excess of metals, can contribute to certain diabetic outcomes. Therefore, this paper will report the blood levels of chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), mercury (Hg), nickel (Ni), lead (Pb), selenium (Se), and zinc (Zn) in subjects with type 1 diabetes (n = 192, mean age 48.8 years, mean disease duration 20.6 years), type 2 diabetes (n = 68, mean age 68.4 years, mean disease duration 10.2 years), and in control subjects (n = 59, mean age 57.2 years), and discuss the results indicating their possible role in diabetes. The metal concentrations were measured by sector field inductively coupled plasma mass spectrometry after microwave-induced acid digestion of blood samples. The accuracy was checked using a blood-based certified reference material, and recoveries of all elements were in the range of 92-101 % of certified values. Type 1 diabetes was found to be associated with Cr (p = 0.02), Mn (p < 0.001), Ni (p < 0.001), Pb (p = 0.02), and Zn (p < 0.001) deficiency, and type 2 diabetes with Cr (p = 0.014), Mn (p < 0.001), and Ni (p < 0.001) deficiency. These deficiencies were appreciated also subdividing the understudied patients for gender and age groups. Furthermore, in type 1 diabetes, there was a positive correlation between Pb and age (p < 0.001, ρ = 0.400) and Pb and BMI (p < 0.001, ρ = 0.309), while a negative correlation between Fe and age (p = 0.002, ρ = -0.218). In type 2 diabetes, there was a negative correlation between Fe and age (p = 0.017, ρ = -0.294) and Fe and BMI (p = 0.026, ρ = -0.301). Thus, these elements may play a role in both forms of diabetes and combined mineral supplementations could have beneficial effects.

34 CFR 86.1 - What is the purpose of the Drug and Alcohol Abuse Prevention regulations?

Science.gov (United States)

2010-07-01

... 34 Education 1 2010-07-01 2010-07-01 false What is the purpose of the Drug and Alcohol Abuse... ALCOHOL ABUSE PREVENTION General § 86.1 What is the purpose of the Drug and Alcohol Abuse Prevention regulations? The purpose of the Drug and Alcohol Abuse Prevention regulations is to implement section 22 of...

Borides of the group 1 metals of the periodic system

International Nuclear Information System (INIS)

Samsonov, G.V.; Serebryakova, T.I.; Neronov, V.A.

1975-01-01

The borides of alkali metals (lithium, sodium, potassium) and the metals of a copper subgroup (copper, silver, gold) are described. Consideration is given to the crystalline structure and state diagrams of the metal systems within the first group of the Periodic Table with boron. Existence, formation conditions and physico-chemical properties of binary boride phases are characterized. Conclusion is made as to the absence of interaction between boron and silver. Information on the interaction between gold and boron is scanty and conflicting. Methods are described suitable for the production of the borides of the metals within the first group of the Periodic Table [ru

Dissolution of metallic uranium and its alloys. Part 1. Review of analytical and process-scale metallic uranium dissolution

International Nuclear Information System (INIS)

Laue, C.A.; Gates-Anderson, D.; Fitch, T.E.

2004-01-01

This review focuses on dissolution/reaction systems capable of treating uranium metal waste to remove its pyrophoric properties. The primary emphasis is the review of literature describing analytical and production-scale dissolution methods applied to either uranium metal or uranium alloys. A brief summary of uranium's corrosion behavior is included since the corrosion resistance of metals and alloys affects their dissolution behavior. Based on this review, dissolution systems were recommended for subsequent screening studies designed to identify the best system to treat depleted uranium metal wastes at Lawrence Livermore National Laboratory (LLNL). (author)

CFA-1: the first chiral metal-organic framework containing Kuratowski-type secondary building units.

Science.gov (United States)

Schmieder, Phillip; Denysenko, Dmytro; Grzywa, Maciej; Baumgärtner, Benjamin; Senkovska, Irena; Kaskel, Stefan; Sastre, German; van Wüllen, Leo; Volkmer, Dirk

2013-08-14

The novel homochiral metal-organic framework CFA-1 (Coordination Framework Augsburg-1), [Zn5(OAc)4(bibta)3], containing the achiral linker {H2-bibta = 1H,1'H-5,5'-bibenzo[d][1,2,3]triazole}, has been synthesised. The reaction of H2-bibta and Zn(OAc)2·2H2O in N-methylformamide (NMF) (90 °C, 3 d) yields CFA-1 as trigonal prismatic single crystals. CFA-1 serves as a convenient precursor for the synthesis of isostructural frameworks with redox-active metal centres, which is demonstrated by the postsynthetic exchange of Zn(2+) by Co(2+) ions. The framework is robust to solvent removal and has been structurally characterized by synchrotron single-crystal X-ray diffraction and solid state NMR measurements ((13)C MAS- and (1)H MAS-NMR at 10 kHz). Results from MAS-NMR and IR spectroscopy studies are corroborated by cluster and periodic DFT calculations performed on CFA-1 cluster fragments.

Heavy metal concentrations and distribution in surface soils of the Bassa Industrial Zone 1, Douala, Cameroon

International Nuclear Information System (INIS)

Asaah, Victor A.; Abimbola, Akinlolu F.; Suh, Cheo E.

2006-01-01

Partial extraction was carried out on 33 soil samples collected from the Bassa Industrial Zone 1, Douala, Cameroon. From the samples analyzed the following metal concentrations (range) were obtained (in ppm): Ag (0-1.3), As (0-64), Cd(0-7.3), Co(0-31), Cr(34-423), Cu(12-909), Mn(55-3282), Mo(0-81.6), Ni(9-284), Pb (0-3320), Sb (0-30), Sc (0.6-7.5), V (26-110), Zn (30-3782) and Fe (in wt%) (1.50-47.31). Results obtained reveal background and anomalous populations for most of the metals except Sc and V, which have only background populations. Multi-element geochemical anomalies occur within the vicinity of industries, waste dump sites, metal workshops and mechanical workshops. R-mode factor analysis reveals three element associations and two singular elements (As, Cd) accounting for 94% of the total data variance. The three associations are: Ag-Cu-Cr-Fe-Mn-Mo-Ni-Sb; Co-Cu-Pb-Sb-Zn and Sc-V. The geoaccumulation indices show that soils in the Bassa Industrial Zone are moderately to very highly pollute. These metal-laden soils constitute a major health risk to the local population and a cause for concern. This study successfully relates the concentration and distribution of toxic metals in the soils of Bassa Industrial Zone to urban effluents generated mainly from industrial activities. (author)

Tuning dispersion correction in DFT-D2 for metal-molecule interactions: A tailored reparameterization strategy for the adsorption of aromatic systems on Ag(1 1 1)

Science.gov (United States)

Schiavo, Eduardo; Muñoz-García, Ana B.; Barone, Vincenzo; Vittadini, Andrea; Casarin, Maurizio; Forrer, Daniel; Pavone, Michele

2018-02-01

Common local and semi-local density functionals poorly describe the molecular physisorption on metal surfaces due to the lack of dispersion interactions. In the last decade, several correction schemes have been proposed to amend this fundamental flaw of Density Functional Theory. Using the prototypical case of aromatic molecules adsorbed on Ag(1 1 1), we discuss the accuracy of different dispersion-correction methods and present a reparameterization strategy for the simple and effective DFT-D2. For the adsorption of different aromatic systems on the same metallic substrate, good results at feasible computational costs are achieved by means of a fitting procedure against MP2 data.

IGF-1 prevents ANG II-induced skeletal muscle atrophy via Akt- and Foxo-dependent inhibition of the ubiquitin ligase atrogin-1 expression

Science.gov (United States)

Yoshida, Tadashi; Semprun-Prieto, Laura; Sukhanov, Sergiy

2010-01-01

Congestive heart failure is associated with activation of the renin-angiotensin system and skeletal muscle wasting. Angiotensin II (ANG II) has been shown to increase muscle proteolysis and decrease circulating and skeletal muscle IGF-1. We have shown previously that skeletal muscle-specific overexpression of IGF-1 prevents proteolysis and apoptosis induced by ANG II. These findings indicated that downregulation of IGF-1 signaling in skeletal muscle played an important role in the wasting effect of ANG II. However, the signaling pathways and mechanisms whereby IGF-1 prevents ANG II-induced skeletal muscle atrophy are unknown. Here we show ANG II-induced transcriptional regulation of two ubiquitin ligases atrogin-1 and muscle ring finger-1 (MuRF-1) that precedes the reduction of skeletal muscle IGF-1 expression, suggesting that activation of atrogin-1 and MuRF-1 is an initial mechanism leading to skeletal muscle atrophy in response to ANG II. IGF-1 overexpression in skeletal muscle prevented ANG II-induced skeletal muscle wasting and the expression of atrogin-1, but not MuRF-1. Dominant-negative Akt and constitutively active Foxo-1 blocked the ability of IGF-1 to prevent ANG II-mediated upregulation of atrogin-1 and skeletal muscle wasting. Our findings demonstrate that the ability of IGF-1 to prevent ANG II-induced skeletal muscle wasting is mediated via an Akt- and Foxo-1-dependent signaling pathway that results in inhibition of atrogin-1 but not MuRF-1 expression. These data suggest strongly that atrogin-1 plays a critical role in mechanisms of ANG II-induced wasting in vivo. PMID:20228261

Effect of some heavy metals on the growth and development of Pleurotus tuber-regium.

Directory of Open Access Journals (Sweden)

Akpaja EO

2012-02-01

Full Text Available The effects of five heavy metals (cadmium, copper, mercury, lead and zinc on the growth and fruit body production in Pleurotus tuber-regium was investigated. Lead sulphate, zinc sulphate, copper sulphate, cadmium nitrate and mercury chloride were added to garden soil at concentrations of 0, 0.125, 0.25, 0.5, 1.0, and 2.0 mmol per 3 kg of soil. Sclerotia of the test mushroom were used to inoculate the artificially contaminated soil. Mercury prevented growth and fruit body production in P. tuber-regium. Fungal morphometry was greatly affected by lead. The heavy metal content in the fungal biomass complex increased with increase of heavy metal concentration in the soil. The highest concentration (183.06 mg/kg was found in zinc at 2 mmol/L.

Nondestructive Early Detection of Metal Corrosion in Pigmented Coatings with Fluorescent Smart Materials

Science.gov (United States)

2012-05-01

dimethylsulfoxide [ DMSO ]), δ ppm: 1.73 (s, 3H), 1.82 (s, 3H), 6.44 (m, 4H), 6.52 (m, 2H), 7.02 (m, 1H), 7.51 (m, 2H), 7.78 (m, 1H). 13 C NMR (d- DMSO ...EtOH (table 4). One explanation could be that DMSO preferentially coordinated with the salts and prevented dye- metal binding. Figure 6. Solvent ...Acronyms Al aluminum CDCl3 deuterated chloroform Cu copper Cr chromium DMSO dimethylsulfoxide DoD Department of Defense EtOH ethanol FDI

MODEL PEMBELAJARAN PRAKTIK PENGELASAN SHIELED METAL ARC WELDING(SMAW POSISI 1G JURUSAN TEKNIK PENGELASAN

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Masri Bin Ardin

2016-08-01

Full Text Available Penelitian ini bertujuan untuk: (1 mendeskripsikan model pembelajaran praktik yang berlangsung atau disebut model pembelajaran regular praktek pengelasan SMAW posisi 1G di SMK Negeri 2 Pengasih; (2 mengetahui efektifitas dan mendeskripsikan bahan yang digunakan dalam praktek pengelasan SMAW posisi 1G, misalnya: besi plat, mata gerinda, elektroda, dan waktu yang digunakan selama praktek pengelasan SMAW posisi 1G. Penelitian ini merupakan penelitian deskriptif dengan teknik pengumpulan data menggunakan wawancara, dokumentasi, angket dan penilaian skill pengelasan. Asessment skill pengelasan mengacu pada Acean Skill Welding Competition. Hasil penelitian yaitu: (1 model pembelajaran praktek pengelasan SMAW posisi 1G terdiri dari 4 pertemuan teori dan 13 pertemuan praktik; (2 model pembelajaran praktik pengelasan di SMKN 2 Pengasih sudah efektif tetapi untuk rutinitas pengelasan belum efektif untuk membentuk skill pengelasan SMAW posisi 1G dengan sistem assesment Asean Skill Welding Competition. Fasilitas utama dalam praktek pengelasan SMAW posisi 1G adalah mesin las. Sementara itu SMKN 2 pengasih memiliki 6 buah mesin las dengan rasio 1 mesin las untuk 5 orang siswa. Bahan habis pakai untuk 30 orang siswa per semester yang menggunakan model pembelajaran praktek pengelasan adalah besi plat ± 100-150 kg, mata gerinda total ± 5-6 keping, elektroda ± 9-10 box dan total waktunya aktif 77 jam selama satu semester. Kata kunci: pembelajaran Praktik Pengelasan SMAW, Skill Siswa untuk Posisi 1G LEARNING MODEL OF SHIELD METAL ARC WELDING (SMAW PRACTICE OF 1G POSITION AT THE WELDING ENGINEERING DEPARTMENT Abstract This research aimed to: (1 describe the learning model of shield metal arc welding (SMAW practice of 1G position at the Welding Engineering Department of State Vocational High School (SMKN 2 Pengasih; (2 find the effectiveness and describe materials needed in the learning model of shield metal arc welding (SMAW practice of 1G position, for examples

Corrosion Prevention of Cold Rolled Steel Using Water Dispersible Lignosulfonic Acid Doped Polyaniline

Science.gov (United States)

Viswanathan, Tito (Inventor)

2007-01-01

The invention provides coatings useful for preventing corrosion of metals. The coatings comprise a film-forming resin and conductive polymers comprising linearly conjugated x-systems and residues of sulfonated lignin or a sulfonated polyflavonoid or derivatives of solfonated lignin or a sulfonated polyflavonoid. The invention also provides a latex formulation of the coatings, and articles of manufacture comprising a metal substrate and a coating in contact with the metal substrate.

He–He and He–metal interactions in transition metals from first-principles

Energy Technology Data Exchange (ETDEWEB)

Zhang, Pengbo, E-mail: zhangpb@dlmu.edu.cn [Department of Physics, Dalian Maritime University, Dalian 116026 (China); Zou, Tingting [Information Science and Technology College, Dalian Maritime University, Dalian 116026 (China); Zhao, Jijun, E-mail: zhaojj@dlut.edu.cn [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024 (China)

2015-12-15

We investigated the atomistic mechanism of He–He and He–metal interactions in bcc transition metals (V, Nb, Ta, Cr, Mo, W, and Fe) using first-principles methods. We calculated formation energy and binding energy of He–He pair as function of distance within the host lattices. The strengths of He–He attraction in Cr, Mo, W, and Fe (0.37–1.11 eV) are significantly stronger than those in V, Nb, and Ta (0.06–0.17 eV). Such strong attractions mean that He atoms would spontaneously aggregate inside perfect Cr, Mo, W, and Fe host lattices in absence of defects like vacancies. The most stable configuration of He–He pair is <100> dumbbell in groups VB metals, whereas it adopts close <110> configuration in Cr, Mo, and Fe, and close <111> configuration in W. Overall speaking, the He–He equilibrium distances of 1.51–1.55 Å in the group VIB metals are shorter than 1.65–1.70 Å in the group VB metals. Moreover, the presence of interstitial He significantly facilitates vacancy formation and this effect is more pronounced in the group VIB metals. The present calculations help understand the He-metal/He–He interaction mechanism and make a prediction that He is easier to form He cluster and bubbles in the groups VIB metals and Fe.

Fully phase-encoded MRI near metallic implants using ultrashort echo times and broadband excitation.

Science.gov (United States)

Wiens, Curtis N; Artz, Nathan S; Jang, Hyungseok; McMillan, Alan B; Koch, Kevin M; Reeder, Scott B

2018-04-01

To develop a fully phase-encoded MRI method for distortion-free imaging near metallic implants, in clinically feasible acquisition times. An accelerated 3D fully phase-encoded acquisition with broadband excitation and ultrashort echo times is presented, which uses a broadband radiofrequency pulse to excite the entire off-resonance induced by the metallic implant. Furthermore, fully phase-encoded imaging is used to prevent distortions caused by frequency encoding, and to obtain ultrashort echo times for rapidly decaying signal. Phantom and in vivo acquisitions were used to describe the relationship among excitation bandwidth, signal loss near metallic implants, and T 1 weighting. Shorter radiofrequency pulses captured signal closer to the implant by improving spectral coverage and allowing shorter echo times, whereas longer pulses improved T 1 weighting through larger maximum attainable flip angles. Comparisons of fully phase-encoded acquisition with broadband excitation and ultrashort echo times to T 1 -weighted multi-acquisition with variable resonance image combination selective were performed in phantoms and subjects with metallic knee and hip prostheses. These acquisitions had similar contrast and acquisition efficiency. Accelerated fully phase-encoded acquisitions with ultrashort echo times and broadband excitation can generate distortion free images near metallic implants in clinically feasible acquisition times. Magn Reson Med 79:2156-2163, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Role of CrRLK1L Cell Wall Sensors HERCULES1 and 2, THESEUS1, and FERONIA in Growth Adaptation Triggered by Heavy Metals and Trace Elements

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Julia Richter

2017-09-01

Full Text Available Cell walls are not only a protective barrier surrounding protoplasts but serve as signaling platform between the extracellular environment and the intracellular physiology. Ions of heavy metals and trace elements, summarized to metal ions, bind to cell wall components, trigger their modification and provoke growth responses. To examine if metal ions trigger cell wall sensing receptor like kinases (RLKs of the Catharanthus roseus RLK1-like (CrRLK1L family we employed a molecular genetic approach. Quantitative transcription analyses show that HERCULES1 (HERK1, THESEUS1 (THE1, and FERONIA (FER were differently regulated by cadmium (Cd, nickel (Ni, and lead (Pb. Growth responses were quantified for roots and etiolated hypocotyls of related mutants and overexpressors on Cd, copper (Cu, Ni, Pb, and zinc (Zn and revealed a complex pattern of gene specific, overlapping and antagonistic responses. Root growth was often inversely affected to hypocotyl elongation. For example, both HERK genes seem to negatively regulate hypocotyl elongation upon Cd, Ni, Zn, and Pb while they support root growth on Cd, Cu, and Ni. The different THE1 alleles exhibited a similar effect between roots and hypocotyls on Ni, where the loss-of-function mutant was more tolerant while the gain of function mutants were hypersensitive indicating that THE1 is mediating Ni specific inhibition of hypocotyl elongation in the dark. In contrast hypocotyl elongation of the knock-out mutant, fer-4, was hypersensitive to Ni but exhibited a higher tolerance to Cd, Cu, Pb, and Zn. These data indicate an antagonistic action between THE1 and FER in relation to hypocotyl elongation upon excess of Ni. FERs function as receptor for rapid alkalinization factors (RALFs was tested with the indicator bromocresol purple. While fer-4 roots strongly acidified control and metal ion containing media, the etiolated hypocotyls alkalized the media which is consistent with the already shorter hypocotyl of fer-4

Induction of temperate cyanophage AS-1 by heavy metal – copper

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Chu Tin-Chun

2006-02-01

Full Text Available Abstract Background It has been reported that some marine cyanophage are temperate and can be induced from a lysogenic phase to a lytic phase by different agents such as heavy metals. However, to date no significant reports have focused on the temperate nature of freshwater cyanophage/cyanobacteria. Previous experiments with cyanophage AS-1 and cyanobacteria Anacystis nidulans have provided some evidence that AS-1 may have a lysogenic life cycle in addition to the characterized lytic cycle. Results In this study, the possible temperate A. nidulans was treated with different concentrations of heavy metal-copper. CuSO4 with concentrations of 3.1 × 10-3 M, 3.1 × 10-4 M, 3.1 × 10-5 M and 3.1 × 10-6 M were used to detect the induction of AS-1 from A. nidulans. The population of the host, unicellular cyanobacteria Anacystis nidulans, was monitored by direct count and turbidity while the amount of virus produced was derived from plaque forming units (PFU by a direct plating method. The ratio of AS-1 release from A. nidulans was also determined. From these results it appears that AS-1 lysogenic phage can be induced by copper at concentrations from 3.1 × 10-6 M to 3.1 × 10-4 M. Maximal phage induction occurred at 6 hours after addition of copper, with an optimal concentration of 3.1 × 10-6 M. Conclusion Cu2+ is a significant inducer for lysogenic cyanobacterial cells and consequently would be a potential control agent in the cyanobacteria population in fresh water ecosystems.

Antioxidants as a Potential Preventive and Therapeutic Strategy for Cadmium.

Science.gov (United States)

Brzóska, Malgorzata M; Borowska, Sylwia; Tomczyk, Michal

2016-01-01

Epidemiological studies provide a growing number of evidences that chronic exposure to relatively low levels of cadmium (Cd), nowadays taking place in industrialized countries, may cause health hazard. Thus, growing interest has been focused on effective ways of protection from adverse effects of exposure to this heavy metal. Because numerous effects to Cd's toxic action result from its prooxidative properties, it seems reasonable that special attention should be directed to agents that can prevent or reduce this metal-induced oxidative stress and its consequences in tissues, organs and systems at risk of toxicity, including liver, kidneys, testes, ears, eyes, cardiovascular system and nervous system as well as bone tissue. This review discusses a wide range of natural (plant and animal origin) and synthetic antioxidants together with many plant extracts (e.g. black and green tea, Aronia melanocarpa, Allium sativum, Allium cepa, Ocimum sanctum, Phoenix dactylifera, Physalis peruviana, Zingiber officinale) that have been shown to prevent from Cd toxicity. Moreover, some attention has been focused on the fact that substances not possessing antioxidative potential may also prevent Cd-induced oxidative stress and its consequences. So far, most of the data on the protective effects of the natural and synthetic antioxidants and plant extracts come from studies in animals' models; however, numerous of them seem to be promising preventive/therapeutic strategies for Cd toxicity in humans. Further investigation of prophylactic and therapeutic use of antioxidants in populations exposed to Cd environmentally and occupationally is warranted, given that therapeutically effective chelation therapy for this toxic metal is currently lacking.

Function of all-metal separators for waste fuels. Phase 1; Funktion av allmetallseparatorer foer avfallsbraenslen. Etapp 1

Energy Technology Data Exchange (ETDEWEB)

Jacoby, Juergen; Wrangensten, Lars

2004-08-01

Various waste incineration facilities, which use different types of waste fuels, have difficulties with a high content of non-magnetic metal, especially aluminum in their fuels. Aluminum may melt on the grate and can lead to corrosion or fouling in the furnace. Additionally, a high content of aluminum in the flyash may cause difficulties in terms of storage or further use of the ash as e.g. construction material. The industrial demand for efficient separators for non-magnetic metals from a fuel stream is rather large. There is however some uncertainty in the performance and efficiency of metal separators. Two types of separators can be found, the first type is called eddy current separator, the other type is based upon a metal detector with a sorting unit in the form of a chute or similar afterwards. An eddy current separator consists of a fast rotating drum containing several permanent magnets with alternating polarity. Due to the rotation, the change in the magnetic field induces eddy currents in conducting materials. The eddy currents cause a force in non-magnetic metal, the Lorentz force, which repels the material away from the rotating drum while all other material follows the systems flow direction. Systems equipped with a metal detector activate a mechanical sorting device, separate chute or air nozzles, when a metal particle is detected. In contrast to eddy current separators all types of metals can be detected and sorted out by systems based on metal detector. Several technical solutions for metal separation supplied by various manufacturers are described in the report. The companies have been asked to supply product information on the working principle, technical data, efficiency and limits for different types of metals. Two reference power plants have been visited and their experiences with all-metal separators are described. Haendeloeverket in Norrkoeping uses eddy current separators for separation of non-magnetic metals from household waste

FFTF metal fuel pin sodium bond quality verification

International Nuclear Information System (INIS)

Pitner, A.L.; Dittmer, J.O.

1988-12-01

The Fast Flux Test Facility (FFTF) Series III driver fuel design consists of U-10Zr fuel slugs contained in a ferritic alloy cladding. A liquid metal, sodium bond between the fuel and cladding is required to prevent unacceptable temperatures during operation. Excessive voiding or porosity in the sodium thermal bond could result in localized fuel melting during irradiation. It is therefore imperative that bond quality be verified during fabrication of these metal fuel pins prior to irradiation. This document discusses this verification

Literature survey on metal waste form for metallic waste from electrorefiners for the electrometallurgical treatment of spent metallic fuels

International Nuclear Information System (INIS)

Nishimura, Tomohiro

2003-01-01

This report summarizes the recent results of the metal waste form development activities at the Argonne National Laboratory in the USA for high-level radioactive metallic waste (stainless-steel (SS) cladding hulls, zirconium (Zr), noble-metal fission products (NMFPs), etc.) from electrorefiners for the electrometallurgical treatment of spent metallic fuels. Their main results are as follows: (1) SS- 15 wt.% Zr- ∼4 wt.% NMFPs alloy was selected as the metal waste form, (2) metallurgical data, properties, long-term corrosion data, etc. of the alloy have been collected, (3) 10-kg ingots have been produced in hot tests and a 60-kg production machine is under development. The following research should be made to show the feasibility of the metal waste form in Japan: (1) degradation assessment of the metal waste form in Japanese geological repository environments, and (2) clarification of the maximum allowable contents of NMFPs. (author)

Effect of metal properties of casts of steel-15Kh1M1FL on the crack resistance at 565 deg C

International Nuclear Information System (INIS)

Gladshtejn, V.I.; Sheshenev, M.F.

1976-01-01

Results are given of prolonged tests of the metal of industrial casts with various fluidity limits. It has been shown experimentally that a quite satisfactory crack resistance is characteristic of a metal with a fluidity limit in the range 30-50 kgf/mm 2 . Metallographic studies have been conducted. Upon variation of the structure and properties of the 15Kh1M1FL steel during operation, the rate of growth of small cracks (up to 2.0 mm) decreases almost by 3 orders of ten (from 1.4x10 -4 to 2.0x10 -7 mm/hour). Subsequent structural changes during prolonged operation (over 50000 hours) result in a gradual increase in the rate of crack growth. At the same time resistance towards appearance of the impermissible high rate of the crack growth, Ksub(10sup(-3)), diminishes monotonically with the operation time. The metal of industrial 15Kh1M1FL steel casts has good crack resistance (Ksub(10sup(-3)) =30-70 kgf/mmsup(3/2) and Vsub(ef) =) kgf/mm 2 ) and a satisfactory local plasticity (critical opening being no more than 0.20 mm for 10 3 hours)

B Plant Complex pollution prevention plan. Revision 1

International Nuclear Information System (INIS)

Beam, T.G.

1994-01-01

The US Department of Energy (DOE) has directed Westinghouse Hanford Company (WHC) to develop an effective strategy to minimize the generation of hazardous, radioactive, and mixed wastes at Hanford in compliance with state and federal regulations. WHC has formalized a pollution prevention program composed of management policies, management requirements and procedures. This plan addresses pollution prevention for B Plant Complex. A pollution prevention team is in place and has been assigned responsibility for implementing the plan. This plan includes actions and goals for reducing volume and toxicity of waste generated, as well as a basis for evaluation of progress. Descriptions of waste streams, current specific goals, general pollution prevention methods, and specific accomplishments are in the appendices of this plan

Ligand-enhanced electrokinetic remediation of metal-contaminated marine sediments with high acid buffering capacity.

Science.gov (United States)

Masi, Matteo; Iannelli, Renato; Losito, Gabriella

2016-06-01

The suitability of electrokinetic remediation for removing heavy metals from dredged marine sediments with high acid buffering capacity was investigated. Laboratory-scale electrokinetic remediation experiments were carried out by applying two different voltage gradients to the sediment (0.5 and 0.8 V/cm) while circulating water or two different chelating agents at the electrode compartments. Tap water, 0.1 M citric acid and 0.1 M ethylenediaminetetraacetic acid (EDTA) solutions were used respectively. The investigated metals were Zn, Pb, V, Ni and Cu. In the unenhanced experiment, the acid front could not propagate due to the high acid buffering capacity of the sediments; the production of OH(-) ions at the cathode resulted in a high-pH environment causing the precipitation of CaCO3 and metal hydroxides. The use of citric acid prevented the formation of precipitates, but solubilisation and mobilisation of metal species were not sufficiently achieved. Metal removal was relevant when EDTA was used as the conditioning agent, and the electric potential was raised up to 0.8 V/cm. EDTA led to the formation of negatively charged complexes with metals which migrated towards the anode compartment by electromigration. This result shows that metal removal from sediments with high acid buffering capacity may be achieved by enhancing the electrokinetic process by EDTA addition when the acidification of the medium is not economically and/or environmentally sustainable.

PAT-1 safety analysis report addendum.

Energy Technology Data Exchange (ETDEWEB)

Weiner, Ruth F.; Schmale, David T.; Kalan, Robert J.; Akin, Lili A.; Miller, David Russell; Knorovsky, Gerald Albert; Yoshimura, Richard Hiroyuki; Lopez, Carlos; Harding, David Cameron; Jones, Perry L.; Morrow, Charles W.

2010-09-01

The Plutonium Air Transportable Package, Model PAT-1, is certified under Title 10, Code of Federal Regulations Part 71 by the U.S. Nuclear Regulatory Commission (NRC) per Certificate of Compliance (CoC) USA/0361B(U)F-96 (currently Revision 9). The purpose of this SAR Addendum is to incorporate plutonium (Pu) metal as a new payload for the PAT-1 package. The Pu metal is packed in an inner container (designated the T-Ampoule) that replaces the PC-1 inner container. The documentation and results from analysis contained in this addendum demonstrate that the replacement of the PC-1 and associated packaging material with the T-Ampoule and associated packaging with the addition of the plutonium metal content are not significant with respect to the design, operating characteristics, or safe performance of the containment system and prevention of criticality when the package is subjected to the tests specified in 10 CFR 71.71, 71.73 and 71.74.

Targeting of Rac1 prevents bronchoconstriction and airway hyperresponsiveness.

Science.gov (United States)

André-Grégoire, Gwennan; Dilasser, Florian; Chesné, Julie; Braza, Faouzi; Magnan, Antoine; Loirand, Gervaise; Sauzeau, Vincent

2017-11-16

The molecular mechanisms responsible for airway smooth muscle cells' (aSMCs) contraction and proliferation in airway hyperresponsiveness (AHR) associated with asthma are still largely unknown. The small GTPases of the Rho family (RhoA, Rac1, and Cdc42) play a central role in SMC functions including migration, proliferation, and contraction. The objective of this study was to identify the role of Rac1 in aSMC contraction and to investigate its involvement in AHR associated with allergic asthma. To define the role of Rac1 in aSMC, ex and in vitro analyses of bronchial reactivity were performed on bronchi from smooth muscle (SM)-specific Rac1 knockout mice and human individuals. In addition, this murine model was exposed to allergens (ovalbumin or house dust mite extract) to decipher in vivo the implication of Rac1 in AHR. The specific SMC deletion or pharmacological inhibition of Rac1 in mice prevented the bronchoconstrictor response to methacholine. In human bronchi, a similar role of Rac1 was observed during bronchoconstriction. We further demonstrated that Rac1 activation is responsible for bronchoconstrictor-induced increase in intracellular Ca 2+ concentration and contraction both in murine and in human bronchial aSMCs, through its association with phospholipase C β2 and the stimulation of inositol 1,4,5-trisphosphate production. In vivo, Rac1 deletion in SMCs or pharmacological Rac1 inhibition by nebulization of NSC23766 prevented AHR in murine models of allergic asthma. Moreover, nebulization of NSC23766 decreased eosinophil and neutrophil populations in bronchoalveolar lavages from mice with asthma. Our data reveal an unexpected and essential role of Rac1 in the regulation of intracellular Ca 2+ and contraction of aSMCs, and the development of AHR. Rac1 thus appears as an attractive therapeutic target in asthma, with a combined beneficial action on both bronchoconstriction and pulmonary inflammation. Copyright © 2017 American Academy of Allergy, Asthma

Gender-Based Violence Prevention. Issues in Prevention

Science.gov (United States)

Higher Education Center for Alcohol, Drug Abuse, and Violence Prevention, 2012

2012-01-01

This issue of "Issues in Prevention" focuses on gender-based violence prevention. This issue contains the following articles: (1) Preventing Gender-Based Violence: An Overview (Linda Langford); (2) Q&A With Amelia Cobb; (3) Denim Day at HBCUs; (4) Dear Colleague Letter; (5) ED Grants for Violence Prevention; and (6) Higher Education Center…

Metal Exposures at three U.S. electronic scrap recycling facilities.

Science.gov (United States)

Ceballos, Diana; Beaucham, Catherine; Page, Elena

2017-06-01

Many metals found in electronic scrap are known to cause serious health effects, including but not limited to cancer and respiratory, neurologic, renal, and reproductive damage. The National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention performed three health hazard evaluations at electronic scrap recycling facilities in the U.S. to characterize employee exposure to metals and recommend control strategies to reduce these exposures. We performed air, surface, and biological monitoring for metals. We found one overexposure to lead and two overexposures to cadmium. We found metals on non-production surfaces, and the skin and clothing of workers before they left work in all of the facilities. We also found some elevated blood lead levels (above 10 micrograms per deciliter), however no employees at any facility had detectable mercury in their urine or exceeded 34% of the OELs for blood or urine cadmium. This article focuses on sampling results for lead, cadmium, mercury, and indium. We provided recommendations for improving local exhaust ventilation, reducing the recirculation of potentially contaminated air, using respirators until exposures are controlled, and reducing the migration of contaminants from production to non-production areas. We also recommended ways for employees to prevent taking home metal dust by using work uniforms laundered on-site, storing personal and work items in separate lockers, and using washing facilities equipped with lead-removing cleaning products.

Deletion of the Men1 Gene Prevents Streptozotocin-Induced Hyperglycemia in Mice

Directory of Open Access Journals (Sweden)

Yuqing Yang

2010-01-01

Full Text Available Diabetes ultimately results from an inadequate number of functional beta cells in the islets of Langerhans. Enhancing proliferation of functional endogenous beta cells to treat diabetes remains underexplored. Here, we report that excision of the Men1 gene, whose loss-of-function mutation leads to inherited multiple endocrine neoplasia type 1 (MEN1, rendered resistant to streptozotocin-induced hyperglycemia in a tamoxifen-inducible and temporally controlled Men1 excision mouse model as well as in a tissue-specific Men1 excision mouse model. Men1 excision prevented mice from streptozotocin-induced hyperglycemia mainly through increasing the number of functional beta cells. BrdU incorporation by beta cells, islet size, and circulating insulin levels were significantly increased in Men1-excised mice. Membrane localization of glucose transporter 2 was largely preserved in Men1-excised beta cells, but not in Men1-expressing beta cells. Our findings suggest that repression of menin, a protein encoded by the Men1 gene, might be a valuable means to maintain or increase the number of functional endogenous beta cells to prevent or ameliorate diabetes.

Effect of the pillar ligand on preventing agglomeration of ZnO nanoparticles prepared from Zn(II metal-organic frameworks

Directory of Open Access Journals (Sweden)

Maryam Moeinian

2016-01-01

Full Text Available Metal-Organic Frameworks (MOFs represent a new class of highly porous materials. On this regard,  two nano porous metal-organic frameworks of [Zn2(1,4-bdc2(H2O2∙(DMF2]n (1 and [Zn2(1,4-bdc2(dabco]·4DMF·1⁄2H2O (2, (1,4-bdc = benzene-1,4-dicarboxylate, dabco = 1,4-diazabicyclo[2.2.2]octane and DMF = N,N-dimethylformamide were synthesized and characterized. They were used for preparation of ZnO nanomaterials. With calcination of 1, agglomerated ZnO nanoparticles could be fabricated, but by the same process on 2, the tendency of ZnO nanoparticles to agglomeration was decreased. In addition, the ZnO nanoparticles prepared from compound 2 had smaller diameter than those obtained from compound 1. In fact, the role of organic dabco ligands in 2 is similar to the role of polymeric stabilizers in formation of nanoparticles. Finally, considering the various applications of ZnO nanomaterials such as light-emitting diodes, photodetectors, photodiodes, gas sensors and dye-sensitized solar cells (DSSCs, it seems that preparation of ZnO nanomaterials from their MOFs could be one of the simple and effective methods which may be applied for preparation of them.

Countering the Segregation of Transition-Metal Ions in LiMn1/3 Co1/3 Ni1/3 O2 Cathode for Ultralong Life and High-Energy Li-Ion Batteries.

Science.gov (United States)

Luo, Dong; Fang, Shaohua; Tamiya, Yu; Yang, Li; Hirano, Shin-Ichi

2016-08-01

High-voltage layered lithium transition-metal oxides are very promising cathodes for high-energy Li-ion batteries. However, these materials often suffer from a fast degradation of cycling stability due to structural evolutions. It seriously impedes the large-scale application of layered lithium transition-metal oxides. In this work, an ultralong life LiMn1/3 Co1/3 Ni1/3 O2 microspherical cathode is prepared by constructing an Mn-rich surface. Its capacity retention ratio at 700 mA g(-1) is as large as 92.9% after 600 cycles. The energy dispersive X-ray maps of electrodes after numerous cycles demonstrate that the ultralong life of the as-prepared cathode is attributed to the mitigation of TM-ions segregation. Additionally, it is discovered that layered lithium transition-metal oxide cathodes with an Mn-rich surface can mitigate the segregation of TM ions and the corrosion of active materials. This study provides a new strategy to counter the segregation of TM ions in layered lithium transition-metal oxides and will help to the design and development of high-energy cathodes with ultralong life. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Phase 1 study of metallic cask systems for spent fuel management from reactor to repository. Volume I. Phase 1 study summary

International Nuclear Information System (INIS)

1986-02-01

It was proposed to perform a systems evaluation of metallic cask systems in order to define and examine the use of various metallic cask concepts or combination of concepts for the overall inventory management of spent fuel starting with its discharge from reactors to its emplacement in geologic repositories. This systems evaluation occurs in three phases. This three phase systems evaluation leads to a definition and recommendation of a sound and practical metallic cask system to accomplish efficient and effective management of spent fuel in the back end of the nuclear fuel cycle. Phase 1 Study objectives: establish system-wide functional criteria and assumptions; perform the systems engineering needed to define the metallic cask concepts and their feasibility; perform a screening evaluation of the technical and economic merits of the concepts; and recommend those to be included for a more detailed systems evaluation in Phase 2. Phase 2 Study objectives: refine the system-wide functional criteria and assumptions; perform the design engineering needed to enhance the validity and workability of those concepts recommended in Phase 1; and perform a more detailed systems evaluation. Phase 3 Study objectives: conclude the systems evaluation and develop an implementation plan. Volume I presents an overview of the detailed systems evaluation presented in Volume II

Metallization systems for stable ohmic contacts to GaAs

International Nuclear Information System (INIS)

Tandon, J.L.; Douglas, K.D.; Vendura, G.; Kolawa, E.; So, F.C.T.; Nicolet, M.A.

1986-01-01

A metallization scheme to form reproducible and stable ohmic contacts to GaAs is described. The approach is based on the configuration: GaAs/X/Y/Z; where X is a thin metal film (e.g. Pt, Ti, Pd, Ru), Y is an electrically conducting diffusion barrier layer (TiN, W or W/sub 0.7/N/sub 0.3/), and Z is a thick metal layer (e.g. Ag) typically required for bonding or soldering purposes. The value and reproducibility of the contact resistance in these metallization systems results from the uniform steady-state solid-phase reaction of the metal X with GaAs. The stability of the contacts is achieved by the diffusion barrier layer Y, which not only confines the reaction of X with GaAs, but also prevents the top metal layer Z from interfering with this reaction. Applications of such contacts in fabricating stable solar cells are also discussed

DEVELOPMENT OF AG-1 SECTION FI ON METAL MEDIA FILTERS - 9061

International Nuclear Information System (INIS)

Adamson, D.; Waggoner, C.A.

2008-01-01

Development of a metal media standard (FI) for ASME AG-1 (Code on Nuclear Air and Gas Treatment) has been under way for almost ten years. This paper will provide a brief history of the development process of this section and a detailed overview of its current content/status. There have been at least two points when dramatic changes have been made in the scope of the document due to feedback from the full Committee on Nuclear Air and Gas Treatment (CONAGT). Development of the proposed section has required resolving several difficult issues associated with scope; namely, filtering efficiency, operating conditions (media velocity, pressure drop, etc.), qualification testing, and quality control/acceptance testing. A proposed version of Section FI is currently undergoing final revisions prior to being submitted for balloting. The section covers metal media filters of filtering efficiencies ranging from medium (less than 99.97%) to high (99.97% and greater). Two different types of high efficiency filters are addressed; those units intended to be a direct replacement of Section FC fibrous glass HEPA filters and those that will be placed into newly designed systems capable of supporting greater static pressures and differential pressures across the filter elements. Direct replacements of FC HEPA filters in existing systems will be required to meet equivalent qualification and testing requirements to those contained in Section FC. A series of qualification and quality assurance test methods have been identified for the range of filtering efficiencies covered by this proposed standard. Performance characteristics of sintered metal powder vs. sintered metal fiber media are dramatically different with respect to parameters like differential pressures and rigidity of the media. Wide latitude will be allowed for owner specification of performance criteria for filtration units that will be placed into newly designed systems. Such allowances will permit use of the most

Influence of metal dental materials on MR imaging

Energy Technology Data Exchange (ETDEWEB)

Tsuchihashi, Toshio; Chiba, Michiko; Yoshizawa, Satoshi; Sasaki, Sadayuki; Maki, Toshio; Kitagawa, Matsuo; Suzuki, Takeshi [Nippon Medical School, Tokyo (Japan). Main Hospital; Nakata, Minoru; Fujita, Isao

1998-11-01

Differences in magnetic susceptibility produce artifacts and signal loss in magnetic resonance imaging (MRI). This study was undertaken to compare the degree of artifacts on MRI caused by metallic dental materials. The influence on MRI of six types of dental alloys, a dental implant, orthodontic appliance, and magnetic attachment was investigated. Among the dental metals, nickel-chromium alloy and cobalt-chromium alloy, which have ferromagnetism, caused significant metal artifacts. Gold-platinum alloy, gold-silver-palladium alloy, silver alloy, and amalgam alloy produced slight metal artifacts. The orthodontic appliance mainly consisted of iron, and the keeper for its magnetic attachment was made of stainless steel. For these reasons, marked metal artifacts and signal loss could be seen in both of them owing to their ferromagnetism. These results suggest that orthodontic appliances and magnetic attachments impair evaluation of the GRE and EPI techniques. It is therefore preferable to use predominantly diamagnetic or paramagnetic dental materials for MRI of the head and neck. Removable keepers should be used more widely to prevent metal artifacts and enhance safety on MRI. (author)

Influence of metal dental materials on MR imaging

International Nuclear Information System (INIS)

Tsuchihashi, Toshio; Chiba, Michiko; Yoshizawa, Satoshi; Sasaki, Sadayuki; Maki, Toshio; Kitagawa, Matsuo; Suzuki, Takeshi; Nakata, Minoru; Fujita, Isao

1998-01-01

Differences in magnetic susceptibility produce artifacts and signal loss in magnetic resonance imaging (MRI). This study was undertaken to compare the degree of artifacts on MRI caused by metallic dental materials. The influence on MRI of six types of dental alloys, a dental implant, orthodontic appliance, and magnetic attachment was investigated. Among the dental metals, nickel-chromium alloy and cobalt-chromium alloy, which have ferromagnetism, caused significant metal artifacts. Gold-platinum alloy, gold-silver-palladium alloy, silver alloy, and amalgam alloy produced slight metal artifacts. The orthodontic appliance mainly consisted of iron, and the keeper for its magnetic attachment was made of stainless steel. For these reasons, marked metal artifacts and signal loss could be seen in both of them owing to their ferromagnetism. These results suggest that orthodontic appliances and magnetic attachments impair evaluation of the GRE and EPI techniques. It is therefore preferable to use predominantly diamagnetic or paramagnetic dental materials for MRI of the head and neck. Removable keepers should be used more widely to prevent metal artifacts and enhance safety on MRI. (author)

Determination of preventive behaviors for pandemic influenza A/H1N1 based on protection motivation theory among female high school students in Isfahan, Iran.

Science.gov (United States)

Sharifirad, Gholamreza; Yarmohammadi, Parastoo; Sharifabad, Mohammad Ali Morowati; Rahaei, Zohreh

2014-01-01

Influenza A/H1N1 pandemic has recently threatened the health of world's population more than ever. Non-pharmaceutical measures are important to prevent the spread of influenza A/H1N1 and to prevent a pandemic. Effective influenza pandemic management requires understanding of the factors influencing preventive behavioral. This study reports on predictors of students' preventive behaviors for pandemic influenza A/H1N1 using variables based on the protection motivation theory (PMT). In a cross-sectional study, multiple-stage randomized sampling was used to select 300 female students in Isfahan who completed a questionnaire in December 2009. Data were collected using a self-report questionnaire based on PMT. The statistical analysis of the data included bivariate correlations, Mann-Whitney, Kruskal-Wallis, and linear regression. The mean age of participants was 15.62 (SE = 1.1) years old. Majority of participants were aware regarding pandemic influenza A/H1N1 (87.3%, 262 out of 300). Results showed that, protection motivation was highly significant relationship with preventive behavior and predicted 34% of its variance. We found all of the variables with the exception of perceived susceptibility, perceived severity, and response cost were related with protection motivation and explained 22% of its variance. Promotion of students' self-efficacy, and intention to protect themselves from a health threat should be priorities of any programs aimed at promoting preventive behaviors among students. It is also concluded that the protection motivation theory may be used in developing countries, like Iran, as a framework for prevention interventions in an attempt to improve the preventive behaviors of students.

Viral linkage in HIV-1 seroconverters and their partners in an HIV-1 prevention clinical trial.

Directory of Open Access Journals (Sweden)

Mary S Campbell

2011-03-01

Full Text Available Characterization of viruses in HIV-1 transmission pairs will help identify biological determinants of infectiousness and evaluate candidate interventions to reduce transmission. Although HIV-1 sequencing is frequently used to substantiate linkage between newly HIV-1 infected individuals and their sexual partners in epidemiologic and forensic studies, viral sequencing is seldom applied in HIV-1 prevention trials. The Partners in Prevention HSV/HIV Transmission Study (ClinicalTrials.gov #NCT00194519 was a prospective randomized placebo-controlled trial that enrolled serodiscordant heterosexual couples to determine the efficacy of genital herpes suppression in reducing HIV-1 transmission; as part of the study analysis, HIV-1 sequences were examined for genetic linkage between seroconverters and their enrolled partners.We obtained partial consensus HIV-1 env and gag sequences from blood plasma for 151 transmission pairs and performed deep sequencing of env in some cases. We analyzed sequences with phylogenetic techniques and developed a Bayesian algorithm to evaluate the probability of linkage. For linkage, we required monophyletic clustering between enrolled partners' sequences and a Bayesian posterior probability of ≥ 50%. Adjudicators classified each seroconversion, finding 108 (71.5% linked, 40 (26.5% unlinked, and 3 (2.0% indeterminate transmissions, with linkage determined by consensus env sequencing in 91 (84%. Male seroconverters had a higher frequency of unlinked transmissions than female seroconverters. The likelihood of transmission from the enrolled partner was related to time on study, with increasing numbers of unlinked transmissions occurring after longer observation periods. Finally, baseline viral load was found to be significantly higher among linked transmitters.In this first use of HIV-1 sequencing to establish endpoints in a large clinical trial, more than one-fourth of transmissions were unlinked to the enrolled partner

Cotransport of Herbaspirillum chlorophenolicum FA1 and heavy metals in saturated porous media: column studies and modeling approaches

Science.gov (United States)

Li, X.; Xu, H.; Wu, J.

2017-12-01

For in situ biodegradation of organic contaminants in soil and groundwater, precise prediction and monitoring of the movement of the bio-agent is vital for the effectiveness of the subsurface bioremediation technologies. Therefore, the fate and transport of functional microorganisms in porous media has been extensively investigated in the literature, and the effects of a number of physical and chemical factors have been explored. During the bioremediation of contaminated sites, it is highly likely that functional bacteria and heavy metals would be simultaneously present for heavy metals often co-exist with organic contaminants like polycyclic aromatic hydrocarbons (PAHs) in polluted environment. To date, relevant studies on the interactions between heavy metals and functional agents such as PAHs-degrading bacteria are lacking and thus require investigation. In this study, the cotransport of bioremediation agents and heavy metals were evaluated through batch and column experiments. Herbaspirillum chlorophenolicum FA1, a pure bacterial strain capable of absorbing heavy metals and degrading polycyclic aromatic hydrocarbons (PAHs), was used as the model remediation agent, and metal ions of Pb(Ⅱ) and Cd(Ⅱ) were used as the representative heavy metals. Effects of metal species, the concentration of heavy metals, the sequence of entering the media, and the activity of biomass were investigated in detail. In addition, numerical simulations of breakthrough curves (BTC) data were also performed for information gathering. Results of this study could advance our understanding of interactions between functional bacteria and heavy metals during bioremediation process and help to develop successful bioremediation strategies.This work was financially supported by the National Natural Science Foundation of China -Xinjiang Project (U1503282), the National Natural Science Foundation of China (41030746, 41102148), and the Natural Science Foundation of Jiangsu Province (BK20151385

Self-assembly of metal-organic supramolecules: from a metallamacrocycle and a metal-organic coordination cage to 1D or 2D coordination polymers based on flexible dicarboxylate ligands.

Science.gov (United States)

Dai, Fangna; Dou, Jianmin; He, Haiyan; Zhao, Xiaoliang; Sun, Daofeng

2010-05-03

To assemble metal-organic supramolecules such as a metallamacrocycle and metal-organic coordination cage (MOCC), a series of flexible dicarboxylate ligands with the appropriate angle, 2,2'-(2,3,5,6-tetramethyl-1,4-phenylene)bis(methylene)bis(sulfanediyl)dibenzoic acid (H(2)L(1)), 2,2'-(2,5-dimethyl-1,4-phenylene)bis(methylene)bis(sulfanediyl)dibenzoic acid (H(2)L(2)), 2,2'-(2,4,6-trimethyl-1,3-phenylene)bis(methylene)bis(sulfanediyl)dinicotinic acid (H(2)L(3)), and 2,2'-(2,4,6-trimethyl-1,3-phenylene)bis(methylene)bis(sulfanediyl)dibenzoic acid (H(2)L(4)), have been designed and synthesized. Using these flexible ligands to assemble with metal ions, six metal-organic supramolecules, Cd(2)(L(1))(2)(dmf)(4)(H(2)O)(2).H(2)O (1), Mn(3)((1)L(2))(2)((2)L(2))(dmf)(2)(H(2)O)(2).5dmf (2), Cu(4)(L(3))(4)(H(2)O)(4).3dmf (3), Cu(4)(L(4))(4)(dmf)(2)(EtOH)(2).8dmf.6H(2)O (4), Mn(4)(L(4))(4)(dmf)(4)(H(2)O)(4).6dmf.H(2)O (5), and Mn(3)(L(4))(3)(dmf)(4).2dmf.3H(2)O (6), possessing a rectangular macrocycle, MOCCs or their extensions, and 1D or 2D coordination polymers, have been isolated. All complexes have been characterized by single-crystal X-ray diffraction, elemental analysis, and thermogravimetric analysis. Complex 1 is a discrete rectangular macrocycle, while complex 2 is a 2D macrocycle-based coordination polymer in which the L(2) ligand adopts both syn and anti conformations. Complexes 3-5 are discrete MOCCs in which two binuclear metal clusters are engaged by four organic ligands. The different geometries of the secondary building units (SBUs) and the axial coordinated solvates on the SBUs result in their different symmetries. Complex 6 is a 1D coordination polymer, extended from a MOCC made up of two metal ions and three L(4) ligands. All of the flexible dicarboxylate ligands adopt a syn conformation except that in complex 2, indicating that the syn conformational ligand is helpful for the formation of a metallamacrocycle and a MOCC. The magnetic properties of complexes 5

Demonstration of Thermally Sprayed Metal and Polymer Coatings for Steel Structures at Fort Bragg, NC

Science.gov (United States)

2017-09-01

ER D C/ CE RL T R- 17 -3 0 DoD Corrosion Prevention and Control Program Demonstration of Thermally Sprayed Metal and Polymer Coatings...and Polymer Coatings for Steel Structures at Fort Bragg, NC Final Report on Project F07-AR10 Larry D. Stephenson, Alfred D. Beitelman, Richard G...5 2.1.2 Thermoplastic polymer coating (flame spray

Metal Pollutants and Cardiovascular Disease: Mechanisms and Consequences of Exposure

Science.gov (United States)

Solenkova, Natalia V.; Newman, Jonathan D.; Berger, Jeffrey S.; Thurston, George; Hochman, Judith S.; Lamas, Gervasio A.

2014-01-01

Introduction There is epidemiological evidence that metal contaminants may play a role in the development of atherosclerosis and its complications. Moreover, a recent clinical trial of a metal chelator had a surprisingly positive result in reducing cardiovascular events in a secondary prevention population, strengthening the link between metal exposure and cardiovascular disease (CVD). This is, therefore, an opportune moment to review evidence that exposure to metal pollutants, such as arsenic, lead, cadmium, and mercury, are significant risk factors for CVD. Methods We reviewed the English-speaking medical literature to assess and present the epidemiological evidence that 4 metals having no role in the human body (xenobiotic), mercury, lead, cadmium, and arsenic, have epidemiologic and mechanistic links to atherosclerosis and CVD. Moreover, we briefly review how the results of the Trial to Assess Chelation Therapy strengthen the link between atherosclerosis and xenobiotic metal contamination in humans. Conclusions There is strong evidence that xenobiotic metal contamination is linked to atherosclerotic disease and is a modifiable risk factor. PMID:25458643

Human health risk assessment: heavy metal contamination of vegetables in Bahawalpur, Pakistan

Directory of Open Access Journals (Sweden)

Hafiza Hira Iqbal

2016-01-01

Full Text Available Dietary exposure of toxic metals is a vital concern for human health through vegetable consumption, especially in developing countries. Aim of the current study was to determine the health risk related to vegetables contamination of heavy metals by irrigated with sewage and turbine water. Irrigation water sources, soils and vegetables were analyzed for selected metals viz: Pb, Cd, Cr and Ni. Heavy metals in water samples were within the permissible limits except Cd in sewage water. The concentration of heavy metals in soil and vegetables irrigated with turbine water were lower than the safe limits. In case of vegetables irrigated with sewage water, Cd was higher in soil while Pb, Cd and Cr were higher in most of the vegetables. Daily intake of metals, health risk index and Bio-concentration factor was also determined. Health risk index values for Cd, Pb and Ni were exceeded the permissible limits (European Union, 2002. Bio-concentration factor (BCF found to be maximum (16.4 mg/kg in Coriandrum sativum cultivated with sewage water. Raphanus caudatus, Coriandrum sativum, Daucus carota, Allium sativum and Solanum tuberosum showed Health Risk Index of Cd > 1 in adults and children. Allium sativum also showed HRI of Pb > 1 in children. We conclude that the quality of vegetables irrigated with sewage water is poor and not fit for human health, evident from the high concentration of Pb, Cd and Cr. Urgent measures are required to prevent consumption and production vegetables irrigated with of sewage water in the study area.

Incorporation of tungsten metal fibers in a metal and ceramic matrix

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V. Brozek

2017-01-01

Full Text Available Tungsten fibers have high tensile strength but a poor oxidation resistance at elevated temperatures. Using this first characteristic and to prevent oxidation of tungsten coated composite materials in which the primary requirement: reinforcement against destruction or deformation, was studied on tungsten fibers and tungsten wires which were coated by applying the metal and ceramic powders via plasma spraying device in plasma generator WSP®. Deposition took place in an atmosphere of Ar + 7 % H2, sufficient to reduce the oxidized trace amounts of tungsten.

Routine soil testing to monitor heavy metals and boron

Directory of Open Access Journals (Sweden)

Abreu Cleide Aparecida de

2005-01-01

Full Text Available Microelements are an important issue in agriculture, due to their need as micronutrients for plants and also to the possibility of the build-up of toxic levels for plants and animals. Five micronutrients (B, Cu, Fe, Mn, and Zn are routinely determined in soil analysis for advisory purposes. Other four elements (Cd, Cr, Pb, and Ni are considered environmentally important heavy metals in farmland soils. Thus high contents of these metals in cropland might go eventually unnoticed. In this paper we present an approach that can be used to monitor the contents of the nine elements in farmland soils using advisory soil testing. A total of 13,416 soil samples from 21 Brazilian states, 58% of them from the state of São Paulo, sent by farmers were analyzed. Boron was determined by hot water extraction and the other metals were determined by DTPA (pH 7.3 extraction. The ranges of content, given in mg dm-3 soil, were the following: B, 0.01-10.6; Cu, 0.1-56.2; Fe, 0.5-476; Mn, 1-325; Zn, 1-453; Cd, 0.00-3.43, Cr, 0.00-42.9; Ni, 0.00-65.1; Pb, 0.00-63.9. The respective average values for São Paulo were: B-0.32; Cu-2.5; Fe-36; Mn-16; Zn-4.8; Cd-0.02; Cr-0.03; Ni-0.18; Pb-0.85. For other states the results are in the same ranges. The higher values are indicative of anthropogenic inputs, either due to excess application of fertilizers or to industrial or mining activities. The conclusion is that massive chemical analysis of farmland soil samples could serve as a database for indicating potential micronutrient deficiency and excesses or heavy metal buil-up in croplands, allowing preventive actions to be taken.

Metal-insulator transition in SrTi1−xVxO3 thin films

International Nuclear Information System (INIS)

Gu, Man; Wolf, Stuart A.; Lu, Jiwei

2013-01-01

Epitaxial SrTi 1−x V x O 3 (0 ≤ x ≤ 1) thin films were grown on (001)-oriented (LaAlO 3 ) 0.3 (Sr 2 AlTaO 6 ) 0.7 (LSAT) substrates using the pulsed electron-beam deposition technique. The transport study revealed a temperature driven metal-insulator transition (MIT) at 95 K for x = 0.67. The films with higher vanadium concentration (x > 0.67) were metallic corresponding to a Fermi liquid system. In the insulating phase (x < 0.67), the resistivity behavior was governed by Mott's variable range hopping mechanism. The possible mechanisms for the induced MIT are discussed, including the effects of electron correlation, lattice distortion, and Anderson localization

Multifunctional methacrylate-based coatings for glass and metal surfaces

Science.gov (United States)

Pospiech, Doris; Jehnichen, Dieter; Starke, Sandra; Müller, Felix; Bünker, Tobias; Wollenberg, Anne; Häußler, Liane; Simon, Frank; Grundke, Karina; Oertel, Ulrich; Opitz, Michael; Kruspe, Rainer

2017-03-01

In order to prevent freshwater biofouling glass and metal surfaces were coated with novel transparent methacrylate-based copolymers. The multifunctionality of the copolymers, such as adhesion to the substrate, surface polarity, mechanical long-term stability in water, and ability to form metal complexes was inserted by the choice of suitable comonomers. The monomer 2-acetoacetoxy ethyl methacrylate (AAMA) was used as complexing unit to produce copper(II) complexes in the coating's upper surface layer. The semifluorinated monomer 1H,1H,2H,2H-perfluorodecyl methacrylate was employed to adjust the surface polarity and wettability. Comprehensive surface characterization techniques, such as X-ray photoelectron spectroscopy (XPS) and contact angle measurements showed that surface compositions and properties can be easily adjusted by varying the concentrations of the comonomers. The formation of copper(II) complexes along the copolymer chains and their stability against washing out with plenty of water was proven by XPS. Copolymers containing semifluorinated comonomers significantly inhibited the growth of Achnanthidium species. Copolymers with copper-loaded AAMA-sequences were able to reduce both the growth of Achnanthidium spec. and Staphylococcus aureus.

Microstructure and bonding mechanism of Al/Ti bonded joint using Al-10Si-1Mg filler metal

International Nuclear Information System (INIS)

Sohn, Woong H.; Bong, Ha H.; Hong, Soon H.

2003-01-01

The microstructures and liquid state diffusion bonding mechanism of cp-Ti to 1050 Al using an Al-10.0wt.%Si-1.0wt.%Mg filler metal with 100 μm in thickness have been investigated at 620 deg. C under 1x10 -4 Torr. The effects of bonding process parameters on microstructure of bonded joint have been analyzed by using an optical microscope, AES, scanning electron microscopy and EDS. The interfacial bond strength of Al/Ti bonded joints was measured by the single lap shear test. The results show that the bonding at the interface between Al and filler metal proceeds by wetting the Al with molten filler metal, and followed by removal of oxide layer on surface of Al. The interface between Al and filler metal moved during the isothermal solidification of filler metal by the diffusion of Si from filler metal into Al layer. The interface between Al and filler metal became curved in shape with increasing bonding time due to capillary force at grain boundaries. The bonding at the interface between Ti and filler metal proceeds by the formation of two different intermetallic compound layers, identified as Al 5 Si 12 Ti 7 and Al 12 Si 3 Ti 5 , followed by the growth of the intermetallic compound layers. The interfacial bond strength at Al/Ti joint increased with increasing bonding time up to 25 min at 620 deg. C. However, the interfacial bond strength of Al/Ti joint decreased after bonding time of 25 min at 620 deg. C due to formation of cavities in Al near Al/intermetallic interfaces

21 CFR 888.3310 - Hip joint metal/polymer constrained cemented or uncemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint metal/polymer constrained cemented or... Hip joint metal/polymer constrained cemented or uncemented prosthesis. (a) Identification. A hip joint... replace a hip joint. The device prevents dislocation in more than one anatomic plane and has components...

Devoluming method and device for radioactive metal wastes containing zirconium alloy

International Nuclear Information System (INIS)

Komatsu, Masahiko; Wada, Ryutaro.

1996-01-01

The present invention concerns a method of sealing radioactive metal wastes in a capsule and compressing the capsule for devoluming treatment. The method comprises a step of carrying radioactive metal wastes into a sealed chamber having a capacity somewhat greater than that of the capsule, a deaerating step of sucking the air in the sealed chamber to attain a substantially vacuum state, a compression-devoluming step of compression-devoluming the capsule by reducing the volume of the sealed chamber and a transporting step of transporting the devolumed capsule from the sealed chamber. The sealed chamber to which the capsule incorporated with radioactive metal wastes containing a zirconium alloy is carried is then deaerated into a substantially vacuum state. Even if ignitable powdery dusts are generated from the radioactive metal wastes crushed by compression-devoluming of the capsule in the succeeding compression-devoluming step, since the air necessary for ignition is not present, ignition of the powdery dusts is prevented. Alternatively, since the inside of the sealed chamber is filled with an inert gas, ignition of the powdery dusts can effectively be prevented. (N.H.)

An antibiotic, heavy metal resistant and halotolerant Bacillus cereus SIU1 and its thermoalkaline protease

Directory of Open Access Journals (Sweden)

Vikram Surendra

2010-07-01

Full Text Available Abstract Background Many workers have reported halotolerant bacteria from saline conditions capable of protease production. However, antibiotic resistance and heavy metal tolerance pattern of such organisms is not documented very well. Similarly, only a few researchers have reported the pattern of pH change of fermentation medium during the course of protease production. In this study, we have isolated a halotolerant Bacillus cereus SIU1 strain from a non-saline environment and studied its antibiotic and heavy metal resistance pattern. The isolate produces a thermoalkaline protease and changes the medium pH during the course of fermentation. Thermostability of protease was also studied for 30 min. Results Seventy bacterial strains isolated from the soils of Eastern Uttar Pradesh, India were screened for protease production. All of them exhibited protease activity. However, 40% bacterial isolates were found good protease producers as observed by caseinolytic zones on milk agar plates. Among them, culture S-4 was adjudged as the best protease producer, and was identified as Bacillus cereus by morphological, biochemical and 16 S rDNA sequence analyses. The isolate was resistant to heavy metals (As2+, Pb2+, Cs1+ and antibiotics (penicillin, lincomycin, cloxacillin, pefloxacin. Its growth behavior and protease production was studied at 45°C and pH 9.0. The protease units of 88 ml-1 were noted in unoptimized modified glucose yeast extract (GYE medium during early stationary phase at 20 h incubation period. The enzyme was stable in the temperature range of 35°-55°C. Conclusions An antibiotic and heavy metal resistant, halotolerant Bacillus cereus isolate is capable of producing thermoalkaline protease, which is active and stable at pH 9.0 and 35°-55°C. This isolate may be useful in several industrial applications owing to its halotolerance and antibiotic and heavy metal resistance characteristics.

Temperature dependence of rippled corrugations induced on the Rh(1 1 0) surface via ion sputtering

International Nuclear Information System (INIS)

Molle, Alessandro; Buatier de Mongeot, F.; Granone, F.; Buzio, R.; Firpo, G.; Boragno, C.; Valbusa, U.

2005-01-01

Metal surfaces can be easily nanopatterned via ion sputtering: mounds or ripples can be created depending on the surface symmetry and temperature. However, in many cases these structures are unstable at room temperature and above, due to the adatom fast diffusion. This fact prevents the use of such systems as substrate or nanostamps for a technological implementation. In this paper we present a spot profile analysis low energy electron diffraction (SPA-LEED) study on the nanopatterning of a Rh(1 1 0) single crystal. Like the other (1 1 0) metal surfaces, previously investigated, also Rh(1 1 0) shows for increasing temperatures a transition between different rippled morphologies. The main advantage of this system is its stability at room temperature. From SPA-LEED data we can measure the structural features (average periodicity and local faceting) of the observed rippled structures

Space-time quantitative source apportionment of soil heavy metal concentration increments.

Science.gov (United States)

Yang, Yong; Christakos, George; Guo, Mingwu; Xiao, Lu; Huang, Wei

2017-04-01

Assessing the space-time trends and detecting the sources of heavy metal accumulation in soils have important consequences in the prevention and treatment of soil heavy metal pollution. In this study, we collected soil samples in the eastern part of the Qingshan district, Wuhan city, Hubei Province, China, during the period 2010-2014. The Cd, Cu, Pb and Zn concentrations in soils exhibited a significant accumulation during 2010-2014. The spatiotemporal Kriging technique, based on a quantitative characterization of soil heavy metal concentration variations in terms of non-separable variogram models, was employed to estimate the spatiotemporal soil heavy metal distribution in the study region. Our findings showed that the Cd, Cu, and Zn concentrations have an obvious incremental tendency from the southwestern to the central part of the study region. However, the Pb concentrations exhibited an obvious tendency from the northern part to the central part of the region. Then, spatial overlay analysis was used to obtain absolute and relative concentration increments of adjacent 1- or 5-year periods during 2010-2014. The spatial distribution of soil heavy metal concentration increments showed that the larger increments occurred in the center of the study region. Lastly, the principal component analysis combined with the multiple linear regression method were employed to quantify the source apportionment of the soil heavy metal concentration increments in the region. Our results led to the conclusion that the sources of soil heavy metal concentration increments should be ascribed to industry, agriculture and traffic. In particular, 82.5% of soil heavy metal concentration increment during 2010-2014 was ascribed to industrial/agricultural activities sources. Using STK and SOA to obtain the spatial distribution of heavy metal concentration increments in soils. Using PCA-MLR to quantify the source apportionment of soil heavy metal concentration increments. Copyright © 2017

Metallic implants and exposure to radiofrequency radiation

International Nuclear Information System (INIS)

Joyner, K.H.; Fleming, A.H.F.; MacFarlane, I.P.; Hocking, B.

1988-01-01

There is increasing use of radiofrequency radiation (RFR) in industry for communications, welding, security, radio, medicine, navigation etc. It has been recognised for some years that RFR may interact with cardiac pacemakers and steps have been taken to prevent this interference. It is less well recognised that other metallic implants may also act as antennas in an RFR field and possibly cause adverse health effects by heating local tissues. There are a large and increasing number of implants having metal components which may be found in RFR workers. These implants include artificial joints, rods and plates used in orthopaedics, rings in heart valves, wires in sutures, bionic ears, subcutaneous infusion systems and (external) transdermal drug delivery patches 1 . The physician concerned with job placement of such persons requires information on the likelihood of an implant interacting with RFR so as to impair health. The following outlines the approach developed in Telecom Australia, beginning with the general principles and then presenting a specific example discussion of a specific example

Sensor-Augmented Insulin Pumps and Hypoglycemia Prevention in Type 1 Diabetes

DEFF Research Database (Denmark)

Steineck, Isabelle; Ranjan, Ajenthen; Nørgaard, Kirsten

2017-01-01

prevention. We present evidence from randomized trials, observational studies, and meta-analyses including nonpregnant individuals with type 1 diabetes mellitus. We also outline concerns regarding SAPs with and without automated insulin suspension. There is evidence that SAP treatment reduces episodes...

Perceptions of and willingness to engage in public health precautions to prevent 2009 H1N1 influenza transmission

Directory of Open Access Journals (Sweden)

Kozlowski Lynn T

2011-03-01

Full Text Available Abstract Background Recommendations about precautionary behaviors are a key part of public health responses to infectious disease threats such as the 2009 H1N1 pandemic. Individuals' interpretation of recommendations, willingness to comply, and factors predicting willingness were examined. Methods A telephone survey of adult residents of New York State was conducted (N = 807. Respondents reported how they interpreted recommendations, willingness to engage in recommended actions, risk perceptions for H1N1 infection, and perceived efficacy of recommendations. Demographic characteristics were used to calculate sampling weights to obtain population-representative estimates. Results There was substantial variability in interpretation of preventive actions. Willingness to engage in preventive actions also varied substantially; vaccination willingness was substantially lower than other preventive actions. No pattern of demographic characteristics consistently predicted willingness. Perceived efficacy was associated with willingness for all recommendations, and perceived severity was associated with willingness for some recommendations. Conclusions Results suggest that individual interpretation of actions differ widely. The results suggest that current recommendations are not clear to laypeople and are open to different interpretations. These varying interpretations should be considered in crafting public health messages about precautionary behaviors.

[Studies on high temperature oxidation of noble metal alloys for dental use. (III) On high temperature oxidation resistance of noble metal alloys by adding small amounts of alloying elements. (author's transl)].

Science.gov (United States)

Ohno, H

1976-11-01

The previous report pointed out the undesirable effects of high temperature oxidation on the casting. The influence of small separate additions of Zn, Mg, Si, Be and Al on the high temperature oxidation of the noble metal alloys was examined. These alloying elements were chosen because their oxide have a high electrical resistivity and they have much higher affinity for oxygen than Cu. The casting were oxidized at 700 degrees C for 1 hour in air. The results obtained were as follows: 1. The Cu oxides are not observed on the as-cast surface of noble metal alloys containing small amounts of Zn, Mg, Si, Be, and Al. The castings have gold- or silver-colored surface. 2. After heating of the unpolished and polished castings, the additions of Si, Be and Al are effective in preventing oxidation of Cu in the 18 carats gold alloys. Especially the golden surface is obtained by adding Be and Al. But there is no oxidation-resistance on the polished castings in the alloys containing Zn and Mg. 3. The zinc oxide film formed on the as-cast specimen is effective in preventing of oxidation Cu in 18 carats gold alloys. 4. It seems that the addition of Al is most available in dental application.

Development of 1 m HTS conductor using YBCO on textured metal substrate

International Nuclear Information System (INIS)

Yagi, M.; Sakamoto, H.; Mukoyama, S.; Yamamoto, K.; Amemiya, N.; Nagaya, S.; Kashima, N.; Shiohara, Y.

2009-01-01

We fabricated 1 m high temperature superconducting conductor (HTS conductor) using YBa 2 Cu 3 O 7-x coated conductors (YBCO tapes) on textured metal substrates, which are expected to be lower in cost than YBCO tapes using ion-beam assisted deposition. Those substrate and intermediate layers were manufactured by Furukawa Electric, and YBCO and a protective layer were applied to the intermediate layer by Chubu Electric Power. Before fabricating the conductor, a 0.1 mm thick copper tape was soldered to the YBCO tape, and 10 mm wide YBCO tape was divided into three strips by a YAG laser. To have sufficient current capacity for 1 kA, a two-layer conductor was fabricated, and its critical current (I c ) was 1976 A, but the magnetic properties of the textured metal substrates affected the increase in AC loss. In a low current region, the AC loss in this conductor was much higher than the Norris strip model, but approached the Norris strip model in the high current region because the magnetization was almost saturated. Low AC loss of 0.144 W/m at 1 kA rms was achieved even though the conductor had a small outer diameter of 20 mm and was composed of YBCO tapes with magnetic substrates.

Oxidized LDL-induced angiogenesis involves sphingosine 1-phosphate: prevention by anti-S1P antibody.

Science.gov (United States)

Camaré, Caroline; Trayssac, Magali; Garmy-Susini, Barbara; Mucher, Elodie; Sabbadini, Roger; Salvayre, Robert; Negre-Salvayre, Anne

2015-01-01

Neovascularization occurring in atherosclerotic lesions may promote plaque expansion, intraplaque haemorrhage and rupture. Oxidized LDL (oxLDL) are atherogenic, but their angiogenic effect is controversial; both angiogenic and anti-angiogenic effects have been reported. The angiogenic mechanism of oxLDL is partly understood, but the role of the angiogenic sphingolipid, sphingosine 1-phosphate (S1P), in this process is not known. Thus, we investigated whether S1P is involved in the oxLDL-induced angiogenesis and whether an anti-S1P monoclonal antibody can prevent this effect. Angiogenesis was assessed by capillary tube formation by human microvascular endothelial cells (HMEC-1) cultured on Matrigel and in vivo by the Matrigel plug assay in C57BL/6 mice. Human oxLDL exhibited a biphasic angiogenic effect on HMEC-1; low concentrations were angiogenic, higher concentrations were cytotoxic. The angiogenic response to oxLDL was blocked by the sphingosine kinase (SPHK) inhibitor, dimethylsphingosine, by SPHK1-siRNA and by an anti-S1P monoclonal antibody. Moreover, inhibition of oxLDL uptake and subsequent redox signalling by anti-CD36 and anti-LOX-1 receptor antibodies and by N-acetylcysteine, respectively, blocked SPHK1 activation and tube formation. In vivo, in the Matrigel plug assay, low concentrations of human oxLDL or murine oxVLDL also triggered angiogenesis, which was prevented by i.p. injection of the anti-S1P antibody. These data highlight the role of S1P in angiogenesis induced by oxLDL both in HMEC-1 cultured on Matrigel and in vivo in the Matrigel plug model in mice, and demonstrate that the anti-S1P antibody effectively blocks the angiogenic effect of oxLDL. © 2014 The British Pharmacological Society.

Identification of a divalent metal cation binding site in herpes simplex virus 1 (HSV-1) ICP8 required for HSV replication.

Science.gov (United States)

Bryant, Kevin F; Yan, Zhipeng; Dreyfus, David H; Knipe, David M

2012-06-01

Herpes simplex virus 1 (HSV-1) ICP8 is a single-stranded DNA-binding protein that is necessary for viral DNA replication and exhibits recombinase activity in vitro. Alignment of the HSV-1 ICP8 amino acid sequence with ICP8 homologs from other herpesviruses revealed conserved aspartic acid (D) and glutamic acid (E) residues. Amino acid residue D1087 was conserved in every ICP8 homolog analyzed, indicating that it is likely critical for ICP8 function. We took a genetic approach to investigate the functions of the conserved ICP8 D and E residues in HSV-1 replication. The E1086A D1087A mutant form of ICP8 failed to support the replication of an ICP8 mutant virus in a complementation assay. E1086A D1087A mutant ICP8 bound DNA, albeit with reduced affinity, demonstrating that the protein is not globally misfolded. This mutant form of ICP8 was also recognized by a conformation-specific antibody, further indicating that its overall structure was intact. A recombinant virus expressing E1086A D1087A mutant ICP8 was defective in viral replication, viral DNA synthesis, and late gene expression in Vero cells. A class of enzymes called DDE recombinases utilize conserved D and E residues to coordinate divalent metal cations in their active sites. We investigated whether the conserved D and E residues in ICP8 were also required for binding metal cations and found that the E1086A D1087A mutant form of ICP8 exhibited altered divalent metal binding in an in vitro iron-induced cleavage assay. These results identify a novel divalent metal cation-binding site in ICP8 that is required for ICP8 functions during viral replication.

Metal-metal interaction mediates the iron induction of Drosophila MtnB

International Nuclear Information System (INIS)

Qiang, Wenjia; Huang, Yunpeng; Wan, Zhihui; Zhou, Bing

2017-01-01

Metallothionein (MT) protein families are a class of small and universal proteins rich in cysteine residues. They are synthesized in response to heavy metal stresses to sequester the toxic ions by metal-thiolate bridges. Five MT family members, namely MtnA, MtnB, MtnC, MtnD and MtnE, have been discovered and identified in Drosophila. These five isoforms of MTs are regulated by metal responsive transcription factor dMTF-1 and play differentiated but overlapping roles in detoxification of metal ions. Previous researches have shown that Drosophila MtnB responds to copper (Cu), cadmium (Cd) and zinc (Zn). Interestingly in this study we found that Drosophila MtnB expression also responds to elevated iron levels in the diet. Further investigations revealed that MtnB plays limited roles in iron detoxification, and the direct binding of MtnB to ferrous iron in vitro is also weak. The induction of MtnB by iron turns out to be mediated by iron interference of other metals, because EDTA at even a partial concentration of that of iron can suppress this induction. Indeed, in the presence of iron, zinc homeostasis is altered, as reflected by expression changes of zinc transporters dZIP1 and dZnT1. Thus, iron-mediated MtnB induction appears resulting from interrupted homeostasis of other metals such as zinc, which in turns induced MtnB expression. Metal-metal interaction may more widely exist than we expected. - Highlights: • Metallothionein B expression is regulated by iron in Drosophila melanogaster. • MtnB has limited physiological roles in iron detoxification. • Binding affinity of MtnB to iron is weak in vitro. • Induction of Drosophila MtnB by iron is mediated indirectly through metal-metal interaction.

Inspection and control of recycling metals in Iran

International Nuclear Information System (INIS)

Rostampour Samarin, A.

2002-01-01

Full text: Recently, the metal recycling industries have become aware of radioactive materials in metal scrap. There have been some cases where radiation sources were unintentionally smelted in the course of recycling metal scrap internationally. To solve the problem, industry and Regulatory Authority have jointly undertaken initiatives to increase awareness of the problem within the industry. Radiation detection systems have been installed by custom services and mills to lessen the potential for the risk to public health from radiation contamination and for financial losses. Based on above matters, the article presents how National Radiation Protection Department (NRPD) can lessen the imports of potential contamination through several means, such as the installation of monitoring system, and implementation of prevention measures. (author)

[Regulatory role of NKT cells in the prevention of type 1 diabetes].

Science.gov (United States)

Ghazarian, Liana; Simoni, Yannick; Pingris, Karine; Beaudoin, Lucie; Lehuen, Agnès

2013-01-01

Type 1 diabetes is an autoimmune disease resulting from the destruction of pancreatic β cells by the immune system. NKT cells are innate-like T cells that can exert potent immuno-regulatory functions. The regulatory role of NKT cells was initially proposed after the observed decreased frequency of this subset in mouse models of type 1 diabetes, as well as in patients developing various autoimmune pathologies. Increasing NKT cell frequency and function prevent the development of type 1 diabetes in mouse models. Several mechanisms including IL-4 and IL-10 production by NKT cells and the accumulation of tolerogenic dendritic cells are critical for the dampening of pathogenic anti-islet T cell responses by NKT cells. Importantly, these cells can at the same time prevent diabetes and promote efficient immune responses against infectious agents. These results strengthen the potential role of NKT cells as a key target for the development of therapeutic strategies against type 1 diabetes. © 2013 médecine/sciences – Inserm.

SU-E-I-92: Is Photon Starvation Preventing Metal Artifact Reduction Algorithm From Working in KVCT?

Energy Technology Data Exchange (ETDEWEB)

Paudel, M [University of Alberta, Cross Cancer Institute, Edmonton, AB (Canada); currently at University of Toronto, Sunnybrook Health Sciences Center, Toronto, ON (Canada); MacKenzie, M; Fallone, B; Rathee, S [University of Alberta, Cross Cancer Institute, Edmonton, AB (Canada)

2014-06-01

Purpose: High density/high atomic number metallic objects create shading and streaking metal artifacts in the CT image that can cause inaccurate delineation of anatomical structures or inaccurate radiation dose calculation. A modified iterative maximum-likelihood polychromatic algorithm for CT (mIMPACT) that models the energy response of detectors, photon interaction processes and beam polychromaticity has successfully reduced metal artifacts in MVCT. Our extension of mIMPACT in kVCT did not significantly reduce metal artifacts for high density metal like steel. We hypothesize that photon starvation may result in the measured data in a commercial kVCT imaging beam. Methods: We measured attenuation of a range of steel plate thicknesses, sandwiched between two 12cm thick solid water blocks, using a Phillips Big Bore CTTM scanner in scout acquisition mode with 120kVp and 200mAs. The transmitted signal (y) was normalized to the air scan signal (y{sub 0}) to get attenuation [i.e., ln(y/y{sub 0})] data for a detector. Results: Below steel plate thickness of 13.4mm, the variations in measured attenuation as a function of view number are characterized by a quantum noise and show increased attenuation with metal thickness. On or above this thickness the attenuation shows discrete levels in addition to the quantum noise. Some views have saturated attenuation value. The histograms of the measured attenuation for up to 36.7mm of steel show this trend. The detector signal is so small that the quantization levels in the analog to digital (A-to-D) converter are visible, a clear indication of photon starvation. Conclusion: Photons reaching the kVCT detector after passing through a thick metal plate are either so low in number that the signal measured has large quantum noise, or are completely absorbed inside the plate creating photon starvation. This is un-interpretable by the mIMPACT algorithm and cannot reduce metal artifacts in kVCT for certain realistic thicknesses of steel

Synthesis, characterization and photocatalytic activity of noble metal-modified TiO2 nanosheets with exposed {0 0 1} facets

International Nuclear Information System (INIS)

Diak, Magdalena; Grabowska, Ewelina; Zaleska, Adriana

2015-01-01

Graphical abstract: - Highlights: • TiO 2 nanosheets with exposed {0 0 1} facets were prepared by hydrothermal method. • Pd and Ag NPs-loaded enhanced the photocatalytic activity under visible irradiation. • Photodeposition is an effective method to obtain noble metal NPs on TiO 2 surface. - Abstract: Pt, Pd, Ag and Au nanoparticles were photodeposited on the {0 0 1} crystal facets of the TiO 2 anatase nanosheets. Morphological and surface characterization of the samples as well as photocatalytic activity were studied. The influence of metal precursor concentration used during photodeposition (0.05−0.5%) on size of formed metal nanoparticles together with UV and vis-mediated activity of Pt, Pd, Ag or Au−TiO 2 was investigated. Generally, samples obtained by photodeposition of noble metal nanoparticles using their 0.2% precursor solutions revealed highest activity in phenol degradation reaction under visible light (λ > 420 nm). The photoactivity of the as-prepared samples with respect to the modified metal species was ordered Ag≅Pd > Au > Pt. TEM analysis showed that photodeposited metal nanoparticles appeared only on {0 0 1} facets of TiO 2 . The average degradation rate of phenol in the presence of Pd and Ag−TiO 2 was 0.5 μmol dm −3 min −1 after 60 min of irradiation under visible light, and was five times higher than that of pure TiO 2 nanosheets

Prediction of molecular separation of polar-apolar mixtures on heterogeneous metal-organic frameworks: HKUST-1.

Science.gov (United States)

Van Assche, Tom R C; Duerinck, Tim; Van der Perre, Stijn; Baron, Gino V; Denayer, Joeri F M

2014-07-08

Due to the combination of metal ions and organic linkers and the presence of different types of cages and channels, metal-organic frameworks often possess a large structural and chemical heterogeneity, complicating their adsorption behavior, especially for polar-apolar adsorbate mixtures. By allocating isotherms to individual subunits in the structure, the ideal adsorbed solution theory (IAST) can be adjusted to cope with this heterogeneity. The binary adsorption of methanol and n-hexane on HKUST-1 is analyzed using this segregated IAST (SIAST) approach and offers a significant improvement over the standard IAST model predictions. It identifies the various HKUST-1 cages to have a pronounced polar or apolar adsorptive behavior.

Studies of Metal-Metal Bonded Compounds in Catalysis

Energy Technology Data Exchange (ETDEWEB)

Berry, John F. [Univ. of Wisconsin, Madison, WI (United States)

2018-01-19

The overall goals of this research are (1) to define the fundamental coordination chemistry underlying successful catalytic transformations promoted by metal-metal bonded compounds, and (2) to explore new chemical transformations that occur at metal-metal bonded sites that could lead to the discovery of new catalytic processes. Transformations of interest include metal-promoted reactions of carbene, nitrene, or nitrido species to yield products with new C–C and C–N bonds, respectively. The most promising suite of transition metal catalysts for these transformations is the set of metal-metal bonded coordination compounds of Ru and Rh of the general formula M₂(ligand)₄, where M = Ru or Rh and ligand = a monoanionic, bridging ligand such as acetate. Development of new catalysts and improvement of catalytic conditions have been stymied by a general lack of knowledge about the nature of highly reactive intermediates in these reactions, the knowledge that is to be supplied by this work. Our three specific objectives for this year have been (A) to trap, isolate, and characterize new reactive intermediates of general relevance to catalysis, (B) to explore the electronic structure and reactivity of these unusual species, and how these two properties are interrelated, and (C) to use our obtained mechanistic knowledge to design new catalysts with a focus on Earth-abundant first-row transition metal compounds.

Broadly neutralizing antibodies for treatment and prevention of HIV-1 infection.

Science.gov (United States)

Cohen, Yehuda Z; Caskey, Marina

2018-04-24

Several anti-HIV-1 broadly neutralizing antibodies (bNAbs) with exceptional breadth and potency that target different HIV-1 envelope epitopes have been identified. bNAbs are an attractive new strategy for HIV-1 prevention and therapy, and potentially, for long-term remission or cure. Here, we discuss findings from early clinical studies that have evaluated these novel bNAbs. Phase 1 studies of bNAbs targeting two distinct HIV-1 envelope epitopes have demonstrated their favorable safety and pharmacokinetic profile. Single bNAb infusions led to significant, but transient, decline in viremia with selection of escape variants. A single bNAb also delayed viral rebound in ART-treated participants who discontinued ART. Importantly, in-vivo efficacy was related to antibody potency and to the level of preexisting resistance. Studies in animal models showed that bNAbs can clear HIV-infected cells and modulate host immune responses. These findings suggest that bNAbs may target the latent HIV reservoir in humans and could contribute to long-term remission of HIV-1 infection. bNAbs may offer advantages over traditional ART for both the prevention and treatment of HIV-1 infection. In addition, bNAbs may target the latent viral reservoir. bNAb combinations and bNAbs engineered for prolonged half-life and increased potency are currently undergoing clinical evaluation.

Synthesis of metal-adeninate frameworks with high separation capacity on C{sub 2}/C{sub 1} hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

He, Yan-Ping, E-mail: hyp041@163.com [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Zhou, Nan [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Hunan GuangYi Experimental Middle School, Changsha, Hunan 410014 (China); Tan, Yan-Xi; Wang, Fei; Zhang, Jian [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)

2016-06-15

By introducing isophthalic acid or 2,5-thiophenedicarboxylic acid to assemble with adenine and cadmium salt, two isostructural and anionic porous metal-organic frameworks (1 and 2) possessing the novel (4,8)-connected sqc topology are presented here. 1 shows permanent porosity with Langmuir surface area of 770.1 m{sup 2}/g and exhibits high separation capacity on C{sub 2}/C{sub 1} hydrocarbons. - Graphical abstract: The assembly between isophthalic acid, adenine ligands and Cd{sup 2+} ions leads to an anionic porous metal-organic frameworks, which shows permanent porosity and exhibits high C{sub 2}/C{sub 1} hydrocarbons separation capacity. Display Omitted.

Fenretinide causes emphysema, which is prevented by sphingosine 1-phoshate.

Directory of Open Access Journals (Sweden)

Masanori Yasuo

Full Text Available Sphingolipids play a role in the development of emphysema and ceramide levels are increased in experimental models of emphysema; however, the mechanisms of ceramide-related pulmonary emphysema are not fully understood. Here we examine mechanisms of ceramide-induced pulmonary emphysema. Male Sprague-Dawley rats were treated with fenretinide (20 mg/kg BW, a synthetic derivative of retinoic acid that causes the formation of ceramide, and we postulated that the effects of fenretinide could be offset by administering sphingosine 1-phosphate (S1P (100 µg/kg BW. Lung tissues were analyzed and mean alveolar airspace area, total length of the alveolar perimeter and the number of caspase-3 positive cells were measured. Hypoxia-inducible factor alpha (HIF-1α, vascular endothelial growth factor (VEGF and other related proteins were analyzed by Western blot analysis. Immunohistochemical analysis of HIF-1α was also performed. Ceramide, dihydroceramide, S1P, and dihydro-S1P were measured by mass spectrometer. Chronic intraperitoneal injection of fenretinide increased the alveolar airspace surface area and increased the number of caspase-3 positive cells in rat lungs. Fenretinide also suppressed HIF-1α and VEGF protein expression in rat lungs. Concomitant injection of S1P prevented the decrease in the expression of HIF-1α, VEGF, histone deacetylase 2 (HDAC2, and nuclear factor (erythroid-derived 2-like 2 (Nrf2 protein expression in the lungs. S1P injection also increased phosphorylated sphingosine kinase 1. Dihydroceramide was significantly increased by fenretinide injection and S1P treatment prevented the increase in dihydroceramide levels in rat lungs. These data support the concept that increased de novo ceramide production causes alveolar septal cell apoptosis and causes emphysema via suppressing HIF-1α. Concomitant treatment with S1P normalizes the ceramide-S1P balance in the rat lungs and increases HIF-1α protein expression via activation of

Requirement of RIZ1 for cancer prevention by methyl-balanced diet.

Science.gov (United States)

Zhou, Wenyun; Alonso, Sergio; Takai, Daisaku; Lu, Shelly C; Yamamoto, Fumiichiro; Perucho, Manuel; Huang, Shi

2008-01-01

The typical Western diet is not balanced in methyl nutrients that regulate the level of the methyl donor S-adenosylmethionine (SAM) and its derivative metabolite S-adenosylhomocysteine (SAH), which in turn may control the activity of certain methyltransferases. Feeding rodents with amino acid defined and methyl-imbalanced diet decreases hepatic SAM and causes liver cancers. RIZ1 (PRDM2 or KMT8) is a tumor suppressor and functions in transcriptional repression by methylating histone H3 lysine 9. Here we show that a methyl-balanced diet conferred additional survival benefits compared to a tumor-inducing methyl-imbalanced diet only in mice with wild type RIZ1 but not in mice deficient in RIZ1. While absence of RIZ1 was tumorigenic in mice fed the balanced diet, its presence did not prevent tumor formation in mice fed the imbalanced diet. Microarray and gene expression analysis showed that, unlike most of its related enzymes, RIZ1 was upregulated by methyl-balanced diet. Methyl-balanced diet did not fully repress oncogenes such as c-Jun in the absence of RIZ1. Higher RIZ1 activity was associated with greater H3 lysine 9 methylation in RIZ1 target genes as shown by chromatin immunoprecipitation analysis. The data identify RIZ1 as a critical target of methyl-balanced diet in cancer prevention. The molecular understanding of dietary carcinogenesis may help people make informed choices on diet, which may greatly reduce the incidence of cancer.

Basis and Statistical Design of the Passive HIV-1 Antibody Mediated Prevention (AMP) Test-of-Concept Efficacy Trials.

Science.gov (United States)

Gilbert, Peter B; Juraska, Michal; deCamp, Allan C; Karuna, Shelly; Edupuganti, Srilatha; Mgodi, Nyaradzo; Donnell, Deborah J; Bentley, Carter; Sista, Nirupama; Andrew, Philip; Isaacs, Abby; Huang, Yunda; Zhang, Lily; Capparelli, Edmund; Kochar, Nidhi; Wang, Jing; Eshleman, Susan H; Mayer, Kenneth H; Magaret, Craig A; Hural, John; Kublin, James G; Gray, Glenda; Montefiori, David C; Gomez, Margarita M; Burns, David N; McElrath, Julie; Ledgerwood, Julie; Graham, Barney S; Mascola, John R; Cohen, Myron; Corey, Lawrence

2017-01-01

Anti-HIV-1 broadly neutralizing antibodies (bnAbs) have been developed as potential agents for prevention of HIV-1 infection. The HIV Vaccine Trials Network and the HIV Prevention Trials Network are conducting the Antibody Mediated Prevention (AMP) trials to assess whether, and how, intravenous infusion of the anti-CD4 binding site bnAb, VRC01, prevents HIV-1 infection. These are the first test-of-concept studies to assess HIV-1 bnAb prevention efficacy in humans. The AMP trials are two parallel phase 2b HIV-1 prevention efficacy trials conducted in two cohorts: 2700 HIV-uninfected men and transgender persons who have sex with men in the United States, Peru, Brazil, and Switzerland; and 1500 HIV-uninfected sexually active women in seven countries in sub-Saharan Africa. Participants are randomized 1:1:1 to receive an intravenous infusion of 10 mg/kg VRC01, 30 mg/kg VRC01, or a control preparation every 8 weeks for a total of 10 infusions. Each trial is designed (1) to assess overall prevention efficacy (PE) pooled over the two VRC01 dose groups vs. control and (2) to assess VRC01 dose and laboratory markers as correlates of protection (CoPs) against overall and genotype- and phenotype-specific infection. Each AMP trial is designed to have 90% power to detect PE > 0% if PE is ≥ 60%. The AMP trials are also designed to identify VRC01 properties (i.e., concentration and effector functions) that correlate with protection and to provide insight into mechanistic CoPs. CoPs are assessed using data from breakthrough HIV-1 infections, including genetic sequences and sensitivities to VRC01-mediated neutralization and Fc effector functions. The AMP trials test whether VRC01 can prevent HIV-1 infection in two study populations. If affirmative, they will provide information for estimating the optimal dosage of VRC01 (or subsequent derivatives) and identify threshold levels of neutralization and Fc effector functions associated with high-level protection, setting a benchmark

Metal-adeninate vertices for the construction of an exceptionally porous metal-organic framework.

Science.gov (United States)

An, Jihyun; Farha, Omar K; Hupp, Joseph T; Pohl, Ehmke; Yeh, Joanne I; Rosi, Nathaniel L

2012-01-03

Metal-organic frameworks comprising metal-carboxylate cluster vertices and long, branched organic linkers are the most porous materials known, and therefore have attracted tremendous attention for many applications, including gas storage, separations, catalysis and drug delivery. To increase metal-organic framework porosity, the size and complexity of linkers has increased. Here we present a promising alternative strategy for constructing mesoporous metal-organic frameworks that addresses the size of the vertex rather than the length of the organic linker. This approach uses large metal-biomolecule clusters, in particular zinc-adeninate building units, as vertices to construct bio-MOF-100, an exclusively mesoporous metal-organic framework. Bio-MOF-100 exhibits a high surface area (4,300 m(2) g(-1)), one of the lowest crystal densities (0.302 g cm(-3)) and the largest metal-organic framework pore volume reported to date (4.3 cm(3) g(-1)).

Control of Orphan Sources and Other Radioactive Material in the Metal Recycling and Production Industries. Specific Safety Guide

International Nuclear Information System (INIS)

2014-01-01

Accidents involving orphan sources and other radioactive material in the metal recycling and production industries have resulted in serious radiological accidents as … well as in harmful environmental, social and economic impacts. This Safety Guide provides recommendations, the implementation of which should prevent such accidents and provide confidence that scrap metal and recycled products are safe. Contents: 1. Introduction; 2. Protection of people and the environment; 3. Responsibilities; 4. Monitoring for radioactive material; 5. Response to the discovery of radioactive material; 6. Remediation of contaminated areas; 7. Management of recovered radioactive material; Annex I: Review of events involving radioactive material in the metal recycling and production industries; Annex II: Categorization of radioactive sources; Annex III: Some examples of national and international initiatives

Control of Orphan Sources and Other Radioactive Material in the Metal Recycling and Production Industries. Specific Safety Guide

International Nuclear Information System (INIS)

2012-01-01

Accidents involving orphan sources and other radioactive material in the metal recycling and production industries have resulted in serious radiological accidents as well as in harmful environmental, social and economic impacts. This Safety Guide provides recommendations, the implementation of which should prevent such accidents and provide confidence that scrap metal and recycled products are safe. Contents: 1. Introduction; 2. Protection of people and the environment; 3. Responsibilities; 4. Monitoring for radioactive material; 5. Response to the discovery of radioactive material; 6. Remediation of contaminated areas; 7. Management of recovered radioactive material; Annex I: Review of events involving radioactive material in the metal recycling and production industries; Annex II: Categorization of radioactive sources; Annex III: Some examples of national and international initiatives.

ADVANCES IN BIOTREATMENT OF ACID MINE DRAINAGE AND BIORECOVERY OF METALS: 1. METAL PRECIPITATION FOR RECOVERY AND RECYCLE

Science.gov (United States)

Acid-mine drainage (AMD) is a severe pollution problem attributed to past mining activities. AMD is an acidic, metal-bearing wastewater generated by the oxidation of metal sulfides to sulfates by Thiobacillus bacteria in both active and abandoned mining operations. The wastewater...

Soil Contamination with Heavy Metals around Jinja Steel Rolling Mills in Jinja Municipality, Uganda

Directory of Open Access Journals (Sweden)

Noel Namuhani

2015-01-01

Conclusions. The concentration levels of heavy metals around the steel rolling mills did not appear to be of serious concern, except for copper and cadmium, which showed moderate pollution and moderate to strong pollution, respectively. All heavy metals were within the limits of the United States Environmental Protection Agency (USEPA residential soil standards and the Dutch intervention soil standards. Overall, soils around the Jinja steel rolling mills were slightly polluted with heavy metals, and measures therefore need to be taken to prevent further soil contamination with heavy metals.

A double metal process

International Nuclear Information System (INIS)

Hawley, F.; Vasche, G.; Caywood, J.M.; Houck, B.; Boyce, J.; Tso, L.

1988-01-01

A dual layer metallization process is studied using a Tungsten 10% Titanium/Molybdenum sandwich (TiW/Mo) first metal with an Al/.5% Cu for the second metal. This metallization process has: 1) very reliable shallow junction contacts without junction spiking, 2) very high electromigration resistance and (3) A very smooth defect free surface throughout the process. Contact resistance of 50 and 30 ohm-um2 for P and N type silicon respectively is achieved. The TiW/Mo film stress is studied and an optimum condition for low compressive stress is defined. The TiW/Mo is etched using a corrosion free etch process. Electromigration data is presented showing TiW/Mo to be at least an order of magnitude better than Al/Si. The intermetal oxide layer is a planarized sandwich of LTO/SOG/LTO providing a smooth positive slope surface for the Metal 2. Metal l/Metal 2 via resistances are studied with 1.25 ohm-um2 values obtained

Accumulation of heavy metals in edible organs of different meat products available in the markets of lahore, pakistan

International Nuclear Information System (INIS)

Baqar, N.; Manzoor, M.; Qadir, M.

2015-01-01

The present study assessed the accumulation of selected heavy metals (Cd, Cr, Pb and Cu) indifferent organs including brain, heart, lungs, liver, stomach, kidney and flesh (muscles) of several animals commercially available in the market of Lahore, Pakistan. The concentrations found in different organs of chicken, goat and cow ranged between 0.132-2.165 mg/g for Cd, 0.768-2.335 mg/g for Cr, 0.260-1.411 mg/g for Pb and 0.092-1.195 mg/g for Cu. In the absence of national safety standards in respect to the content of heavy metals in foodstuffs, the results obtained were compared with international guidelines and found concentrations considerably higher than the prescribed safe limits. Therefore, immediate attention must be paid to prevent public health risks associated with the presence of toxic heavy metals in the commercially available meat products. (author)

Method and Apparatus for Thermal Spraying of Metal Coatings Using Pulsejet Resonant Pulsed Combustion

Science.gov (United States)

Paxson, Daniel E. (Inventor)

2014-01-01

An apparatus and method for thermal spraying a metal coating on a substrate is accomplished with a modified pulsejet and optionally an ejector to assist in preventing oxidation. Metal such as Aluminum or Magnesium may be used. A pulsejet is first initiated by applying fuel, air, and a spark. Metal is inserted continuously in a high volume of metal into a combustion chamber of the pulsejet. The combustion is thereafter controlled resonantly at high frequency and the metal is heated to a molten state. The metal is then transported from the combustion chamber into a tailpipe of said pulsejet and is expelled therefrom at high velocity and deposited on a target substrate.

The potential of socio-psychological models for the development of prevention programs (Part 1

Directory of Open Access Journals (Sweden)

Bovina I.B.

2014-12-01

Full Text Available This paper considers the problem of designing prevention programs in health and disease. We note that smoking cessation on the planet would reduce mortality from various types of cancer by 25%, and would also save the lives of hundreds of thousands of people who die each year from heart attacks. Losing weight by only 10% through proper nutrition and exercise would reduce the incidence of cardiovascular disease, as well as certain types of cancer. Based on the literature review, we reveal the different types of prevention, show the importance of preventive measures aimed at the patient's immediate environment. Among the main difficulties associated with the development of effective prevention programs we discuss the following: 1 ignoring the psychological mechanisms of behavior change; 2 irrelevance of media broadcast methods in prevention campaigns; 3 the time between the problem behavior and its negative effects on health. We discuss the potential of social influence models for the development of prevention programs in the field of health and disease.

Cone Penetrometer for Subsurface Heavy Metals Detection. Semiannual report, November 1, 1996--March 31, 1997

International Nuclear Information System (INIS)

Grisanti, Ames A.; Timpe, Ronald C.; Foster, H.J.; Eylands, Kurt E.; Crocker, Charlene R.

1997-01-01

Surface and subsurface contamination of soils by heavy metals, including Pb, Cr, Cu, Zn, and Cd, has become an area of concern for many industrial and government organizations (1). Conventional sampling and analysis techniques for soil provide a high degree of sensitivity and selectivity for individual analytes. However, obtaining a representative sampling and analysis from a particular site using conventional techniques is time consuming and costly (2). Additionally, conventional methods are difficult to implement in the field for in situ and/or real-time applications. Therefore, there is a need for characterization and monitoring techniques for heavy metals in soils which allow cost-effective, rapid, in situ measurements. Laser-induced breakdown spectroscopy (LIBS) has been used to successfully measure metals content in a variety of matrices (3-15) including soil (16,17). Under the Department of Energy (DOE) Federal Energy Technology Center (FETC) Industry Program, Science ampersand Engineering Associates (SEA) is developing a subsurface cone penetrometer (CPT) probe for heavy metals detection that employs LIBS (18). The LIES-CPT unit is to be applied to in situ, real-time sampling and analysis of heavy metals in soil. As part of its contract with DOE FETC, SEA is scheduled to field test its LIBS-CPT system in September 1997

Cone Penetrometer for Subsurface Heavy Metals Detection. Semiannual report, November 1, 1996--March 31, 1997

Energy Technology Data Exchange (ETDEWEB)

Grisanti, Ames A.; Timpe, Ronald C.; Foster, H.J.; Eylands, Kurt E.; Crocker, Charlene R.

1997-12-31

Surface and subsurface contamination of soils by heavy metals, including Pb, Cr, Cu, Zn, and Cd, has become an area of concern for many industrial and government organizations (1). Conventional sampling and analysis techniques for soil provide a high degree of sensitivity and selectivity for individual analytes. However, obtaining a representative sampling and analysis from a particular site using conventional techniques is time consuming and costly (2). Additionally, conventional methods are difficult to implement in the field for in situ and/or real-time applications. Therefore, there is a need for characterization and monitoring techniques for heavy metals in soils which allow cost-effective, rapid, in situ measurements. Laser-induced breakdown spectroscopy (LIBS) has been used to successfully measure metals content in a variety of matrices (3-15) including soil (16,17). Under the Department of Energy (DOE) Federal Energy Technology Center (FETC) Industry Program, Science {ampersand} Engineering Associates (SEA) is developing a subsurface cone penetrometer (CPT) probe for heavy metals detection that employs LIBS (18). The LIES-CPT unit is to be applied to in situ, real-time sampling and analysis of heavy metals in soil. As part of its contract with DOE FETC, SEA is scheduled to field test its LIBS-CPT system in September 1997.

Metal transformation as a strategy for bacterial detoxification of heavy metals.

Science.gov (United States)

Essa, Ashraf M M; Al Abboud, Mohamed A; Khatib, Sayeed I

2018-01-01

Microorganisms can modify the chemical and physical characters of metals leading to an alteration in their speciation, mobility, and toxicity. Aqueous heavy metals solutions (Hg, Cd, Pb, Ag, Cu, and Zn) were treated with the volatile metabolic products (VMPs) of Escherichia coli Z3 for 24 h using aerobic bioreactor. The effect of the metals treated with VMPs in comparison to the untreated metals on the growth of E. coli S1 and Staphylococcus aureus S2 (local isolates) was examined. Moreover, the toxic properties of the treated and untreated metals were monitored using minimum inhibitory concentration assay. A marked reduction of the treated metals toxicity was recorded in comparison to the untreated metals. Scanning electron microscopy and energy dispersive X-ray analysis revealed the formation of metal particles in the treated metal solutions. In addition to heavy metals at variable ratios, these particles consisted of carbon, oxygen, sulfur, nitrogen elements. The inhibition of metal toxicity was attributed to the existence of ammonia, hydrogen sulfide, and carbon dioxide in the VMPs of E. coli Z3 culture that might responsible for the transformation of soluble metal ions into metal complexes. This study clarified the capability of E. coli Z3 for indirect detoxification of heavy metals via the immobilization of metal ions into biologically unavailable species. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ionothermal synthesis and structural transformation targeted by ion exchange in metal-1,3,5-benzenetricarboxylate compounds

Energy Technology Data Exchange (ETDEWEB)

Xu, Qing-Qing [Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi’an 710062, Shaanxi (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Liu, Bing [College of Chemistry and Chemical Engineering, Shaanxi University of Sciences and Technology, Xi’an 710021, Shaanxi (China); Xu, Ling, E-mail: xuling@snnu.edu.cn [Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi’an 710062, Shaanxi (China); Jiao, Huan, E-mail: jiaohuan@snnu.edu.cn [Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi’an 710062, Shaanxi (China)

2017-03-15

Ionothermal reactions of 1,3,5-benzenetricarboxylate acid (H{sub 3}BTC) and Ni(NO{sub 3}){sub 2}, Co(NO{sub 3}){sub 2} and Cu(NO{sub 3}){sub 2} gave two discrete 32-membered ring-like allomers, [M{sub 2}(HBTC){sub 2}(NH{sub 2}CONH{sub 2}){sub 2}(H{sub 2}O){sub 4}]·3H{sub 2}O (M=Ni(1), Co(2)) and one layered [Cu{sub 2}(BTC)Cl(H{sub 2}O){sub 4}] (3). The weak interactions in 1 can be deconstructed to some degree in ion exchange by exploring the factors of divalent and trivalent metal species, metal concentration and soaking time, which are demonstrated by PXRD and N{sub 2} absorption. Cu{sup 2+} has the highest N{sub 2} adsorbance when soaking with 1, and 1 can keep structure stable when Cu{sup 2+} below 0.16 mol L{sup −1} and the soaking time within 24d. As Cu{sup 2+} beyond 0.16 mol L{sup −1} and the soaking time beyond 24d, the structure of compound 1 starts to transform with the crystal morphology from clear pale green to opaque blue. Ionothermal reactions of compound 1 with different Cu{sup 2+} amounts obtained Ni{sup 2+}-Cu{sup 2+} hetero complexes, whose PXRD patterns are similar to that of 3 and EDS indicates Cu{sup 2+}% increases with Cu{sup 2+} additions and close to 100% as Cu{sup 2+} being 1.6 mmol. It suggests that 3 is a controlled product and Cu{sup 2+} can transform discrete compound 1 into 2D compound 3. - Graphical abstract: Three compounds were synthesized through ionothermal reactions. The weak interactions in compound 1 can be deconstructed by ion exchange and discrete compound 1 can be transformed into layered compound 3. - Highlights: • Two discrete ring-like and one layered compounds were ionothermally synthesized. • Metal species, metal concentration and soaking time deconstruct the H-bondings in 1. • 1 can be transformed to 3 through ionothermal reaction, otherwise forbidden.

Leading research on supermetal. Part 1. Large-scale materials (iron system); Super metal no sendo kenkyu. 1. Ogata sozai (tetsukei)

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

Supermetal with critical characteristics is under advanced investigation for further improvement of metal materials. Although iron is most frequently used as structural material among various metals, it should be used more carefully and effectively because of resource limitation and global environmental problem. It is essential to draw various excellent properties much more from iron and to improve recyclability. In particular, the best way to meet these requirements is achievement of more fine structure and higher purity. Since the lowest crystalline grain size is now limited to nearly 10{mu}m, metallic structure composed of grains below 1{mu}m is expected by mesoscopic control. Various methods have been studied to achieve ultra-fine crystalline structure, and study of precise heat treatment control and ultra-strength metallurgy is required. Heat treatment in magnetic field and layered structure by mechanical alloying are also promising. Drastic enhancement of characteristics is expected for heat resistant steel by combining of high purity with fine structure. 299 refs., 166 figs., 18 tabs.

Hot electrons and the approach to metallic behavior in Kx(KCl)1-x

NARCIS (Netherlands)

Silvestrelli, P.L.; Alavi, A.; Parrinello, M.; Frenkel, D.

1996-01-01

The approach to the metallic phase of molten Kx(KCl)1-x mixtures is studied using ab initio molecular dynamics based on finite-temperature density functional theory. The finite electronic temperature is found to result in new and unexpected effects. In particular, we observe a thermally induced

Surface/structure functionalization of copper-based catalysts by metal-support and/or metal-metal interactions

Science.gov (United States)

Konsolakis, Michalis; Ioakeimidis, Zisis

2014-11-01

Cu-based catalysts have recently attracted great attention both in catalysis and electro-catalysis fields due to their excellent catalytic performance and low cost. Given that their performance is determined, to a great extent, by Cu sites local environment, considerable efforts have been devoted on the strategic modifications of the electronic and structural properties of Cu sites. In this regard, the feasibility of tuning the local structure of Cu entities by means of metal-support or metal-metal interactions is investigated. More specifically, the physicochemical properties of Cu entities are modified by employing: (i) different oxides (CeO2, La2O3, Sm2O3), or (ii) ceria-based mixed oxides (Ce1-xSmxOδ) as supporting carriers, and (iii) a second metal (Cobalt) adjacent to Cu (bimetallic Cu-Co/CeO2). A characterization study, involving BET, XRD, TPR, and XPS, reveal that significant modifications on structural, redox and electronic properties of Cu sites can be induced by adopting either different oxide carriers or bimetallic complexes. Fundamental insights into the tuning of Cu local environment by metal-support or metal-metal interactions are provided, paving the way for real-life industrial applications.

Peroxotitanates for Biodelivery of Metals

Energy Technology Data Exchange (ETDEWEB)

Hobbs, David; Elvington, M.

2009-02-11

Metal-based drugs are largely undeveloped in pharmacology. One limiting factor is the systemic toxicity of metal-based compounds. A solid-phase, sequestratable delivery agent for local delivery of metals could reduce systemic toxicity, facilitating new drug development in this nascent area. Amorphous peroxotitanates (APT) are ion exchange materials with high affinity for several heavy metal ions, and have been proposed to deliver or sequester metal ions in biological contexts. In the current study, we tested a hypothesis that APT are able to deliver metals or metal compounds to cells. We exposed fibroblasts (L929) or monocytes (THP1) to metal-APT materials for 72 h in vitro, then measured cellular mitochondrial activity (SDH-MTT method) to assess the biological impact of the metal-APT materials vs. metals or APT alone. APT alone did not significantly affect cellular mitochondrial activity, but all metal-APT materials suppressed the mitochondrial activity of fibroblasts (by 30-65% of controls). The concentration of metal-APT materials required to suppress cellular mitochondrial activity was below that required for metals alone, suggesting that simple extracellular release of the metals from the metal-APT materials was not the primary mechanism of mitochondrial suppression. In contrast to fibroblasts, no metal-APT material had a measurable effect on THP1 monocyte mitochondrial activity, despite potent suppression by metals alone. This latter result suggested that 'biodelivery' by metal-APT materials may be cell type-specific. Therefore, it appears that APT are plausible solid phase delivery agents of metals or metal compounds to some types of cells for potential therapeutic effect.

Corrosion of metallic materials. Dry corrosion, aqueous corrosion and corrosion by liquid metal, methods of protection

International Nuclear Information System (INIS)

Helie, Max

2015-01-01

This book is based on a course on materials given in an engineering school. The author first gives an overview of metallurgy issues: metallic materials (pure metals, metallic alloys), defects of crystal lattices (point defects, linear defects or dislocations), equilibrium diagrams, steels and cast, thermal processing of steels, stainless steels, aluminium and its alloys, copper and its alloys. The second part addresses the properties and characterization of surfaces and interfaces: singularity of a metal surface, surface energy of a metal, energy of grain boundaries, adsorption at a material surface, metal-electrolyte interface, surface oxide-electrolyte interface, techniques of surface analysis. The third chapter addresses the electrochemical aspects of corrosion: description of the corrosion phenomenon, free enthalpy of a compound and free enthalpy of a reaction, case of dry corrosion (thermodynamic aspect, Ellingham diagram, oxidation mechanisms, experimental study, macroscopic modelling), case of aqueous corrosion (electrochemical thermodynamics and kinetics, experimental determination of corrosion rate). The fourth part addresses the different forms of aqueous corrosion: generalized corrosion (atmospheric corrosion, mechanisms and tests), localized corrosion (galvanic, pitting, cracking, intergranular, erosion and cavitation), particular cases of stress cracking (stress corrosion, fatigue-corrosion, embrittlement by hydrogen), and bi-corrosion (of non alloyed steels, of stainless steels, and of aluminium and copper alloys). The sixth chapter addresses the struggle and the protection against aqueous corrosion: methods of prevention, scope of use of main alloys, geometry-based protection of pieces, use of corrosion inhibitors, use of organic or metallic coatings, electrochemical protection. The last chapter proposes an overview of corrosion types in industrial practices: in the automotive industry, in the oil industry, in the aircraft industry, and in the

Metal ion-mediated agonism and agonist enhancement in melanocortin MC1 and MC4 receptors

DEFF Research Database (Denmark)

Holst, Birgitte; Elling, Christian E; Schwartz, Thue W

2002-01-01

-melanocortin stimulating hormone (alpha-MSH) in the MC1 and MC4 receptors, respectively. In the presence of peptide agonist, Zn(II) acted as an enhancer on both receptors, because it shifted the dose-response curves to the left: most pronounced was a 6-fold increase in alpha-MSH potency on the MC1 receptor. The effect......An endogenous metal-ion site in the melanocortin MC1 and MC4 receptors was characterized mainly in transiently transfected COS-7 cells. ZnCl(2) alone stimulated signaling through the Gs pathway with a potency of 11 and 13 microm and an efficacy of 50 and 20% of that of alpha...... affinities and profiles were similar for a number of the 2,2'-bipyridine and 1,10-phenanthroline analogs in complex with Zn(II) in the MC1 and MC4 receptors. However, the potencies and efficacies of the metal-ion complexes were very different in the two receptors, and close to full agonism was obtained...

Metal interactions with boron clusters

International Nuclear Information System (INIS)

Grimes, R.N.

1982-01-01

This book presents information on the following topics: the structural and bonding features of metallaboranes and metallacarboranes; transition-metal derivatives of nido-boranes and some related species; interactions of metal groups with the octahydrotriborate (1-) anion, B 3 H 8 ; metallaboron cage compounds of the main group metals; closo-carborane-metal complexes containing metal-carbon and metal-boron omega-bonds; electrochemistry of metallaboron cage compounds; and boron clusters with transition metal-hydrogen bonds

Maternal pravastatin prevents altered fetal brain development in a preeclamptic CD-1 mouse model.

Directory of Open Access Journals (Sweden)

Alissa R Carver

Full Text Available Using an animal model, we have previously shown that preeclampsia results in long-term adverse neuromotor outcomes in the offspring, and this phenotype was prevented by antenatal treatment with pravastatin. This study aims to localize the altered neuromotor programming in this animal model and to evaluate the role of pravastatin in its prevention.For the preeclampsia model, pregnant CD-1 mice were randomly allocated to injection of adenovirus carrying sFlt-1 or its control virus carrying mFc into the tail vein. Thereafter they received pravastatin (sFlt-1-pra "experimental group" or water (sFlt-1 "positive control" until weaning. The mFc group ("negative control" received water. Offspring at 6 months of age were sacrificed, and whole brains underwent magnetic resonance imaging (MRI. MRIs were performed using an 11.7 Tesla vertical bore MRI scanner. T2 weighted images were acquired to evaluate the volumes of 28 regions of interest, including areas involved in adaptation and motor, spatial and sensory function. Cytochemistry and cell quantification was performed using neuron-specific Nissl stain. One-way ANOVA with multiple comparison testing was used for statistical analysis.Compared with control offspring, male sFlt-1 offspring have decreased volumes in the fimbria, periaquaductal gray, stria medullaris, and ventricles and increased volumes in the lateral globus pallidus and neocortex; however, female sFlt-1 offspring showed increased volumes in the ventricles, stria medullaris, and fasciculus retroflexus and decreased volumes in the inferior colliculus, thalamus, and lateral globus pallidus. Neuronal quantification via Nissl staining exhibited decreased cell counts in sFlt-1 offspring neocortex, more pronounced in males. Prenatal pravastatin treatment prevented these changes.Preeclampsia alters brain development in sex-specific patterns, and prenatal pravastatin therapy prevents altered neuroanatomic programming in this animal model.

Plasmons in metallic monolayer and bilayer transition metal dichalcogenides

DEFF Research Database (Denmark)

Andersen, Kirsten; Thygesen, Kristian S.

2013-01-01

We study the collective electronic excitations in metallic single-layer and bilayer transition metal dichalcogenides (TMDCs) using time dependent density functional theory in the random phase approximation. For very small momentum transfers (below q≈0.02 Å−1), the plasmon dispersion follows the √q...

Demonstration of Low Impact Development (LID) to Mitigate Stormwater Metal Contaminants in Navy Commercial Areas

Science.gov (United States)

2018-04-01

perforated pipe (1/4-in holes); 7) drain cleanout; 8) backflow preventer on underdrain; 9) blood meal fertilizer by Pro-Pell-it!: soil, Bioswale Mix...several hours expected for these project sites). These metals can form soluble complexes with different inorganic and organic ligands. The complex...valence can range from -2 to +2. Organic and inorganic complexes may be treated by chemically active filtration through compost, peat, and soil. Also

Nondestructive Early Detection of Metal Corrosion in Pigmented Coatings with Fluorescent Smart Materials (First-year Report)

Science.gov (United States)

2012-05-01

dimethylsulfoxide [ DMSO ]), δ ppm: 1.73 (s, 3H), 1.82 (s, 3H), 6.44 (m, 4H), 6.52 (m, 2H), 7.02 (m, 1H), 7.51 (m, 2H), 7.78 (m, 1H). 13 C NMR (d- DMSO ...EtOH (table 4). One explanation could be that DMSO preferentially coordinated with the salts and prevented dye- metal binding. Figure 6. Solvent ...Acronyms Al aluminum CDCl3 deuterated chloroform Cu copper Cr chromium DMSO dimethylsulfoxide DoD Department of Defense EtOH ethanol FDI

Prevention of Device-Related Healthcare-Associated Infections [version 1; referees: 2 approved

Directory of Open Access Journals (Sweden)

Edward J. Septimus

2016-01-01

Full Text Available Healthcare-associated infections (HAIs are a leading cause of morbidity and mortality in hospitalized patients. Up to 15% of patients develop an infection while hospitalized in the United States, which accounts for approximately 1.7 million HAIs, 99,000 deaths annually and over 10 billion dollars in costs per year. A significant percentage of HAIs are preventable using evidenced-based strategies. In terms of device-related HAIs it is estimated that 65-70% of catheter-line associated bloodstream infections (CLABSIs and catheter-associated urinary tract infections (CAUTIs are preventable. To prevent CLABSIs a bundle which includes hand hygiene prior to insertion and catheter manipulation, use of chlorhexidene alcohol for site preparation and maintenance, use of maximum barrier for catheter insertion, site selection, removing nonessential lines, disinfect catheter hubs before assessing line, and dressing changes are essential elements of basic practices. To prevent CAUTIs a bundle that includes hand hygiene for insertion and catheter or bag manipulation, inserting catheters for appropriate indications, insert using aseptic technique, remove catheters when no longer needed, maintain a close system keeping bag and tubing below the bladder are the key components of basic practices.

In-situ ductile metal/bulk metallic glass matrix composites formed by chemical partitioning

Science.gov (United States)

Kim, Choong Paul; Hays, Charles C.; Johnson, William L.

2004-03-23

A composite metal object comprises ductile crystalline metal particles in an amorphous metal matrix. An alloy is heated above its liquidus temperature. Upon cooling from the high temperature melt, the alloy chemically partitions, forming dendrites in the melt. Upon cooling the remaining liquid below the glass transition temperature it freezes to the amorphous state, producing a two-phase microstructure containing crystalline particles in an amorphous metal matrix. The ductile metal particles have a size in the range of from 0.1 to 15 micrometers and spacing in the range of from 0.1 to 20 micrometers. Preferably, the particle size is in the range of from 0.5 to 8 micrometers and spacing is in the range of from 1 to 10 micrometers. The volume proportion of particles is in the range of from 5 to 50% and preferably 15 to 35%. Differential cooling can produce oriented dendrites of ductile metal phase in an amorphous matrix. Examples are given in the Zr--Ti--Cu--Ni--Be alloy bulk glass forming system with added niobium.

Self-assembled monolayers on mosoporous supports (SAMMS) for RCRA metal removal

Energy Technology Data Exchange (ETDEWEB)

Feng, Xiangdong; Liu, Jun; Fryxell, G. [Pacific Northwest National Lab., Richland, WA (United States)

1997-10-01

The Mixed Waste Focus Area has declared mercury removal and stabilization as the first and fourth priorities among 30 prioritized deficiencies. Resource Conservation and Recovery Act (RCRA) metal and mercury removal has also been identified as a high priority at DOE sites such as Albuquerque, Idaho Falls, Oak Ridge, Hanford, Rocky Flats, and Savannah River. Under this task, a proprietary new technology, Self-Assembled Monolayers on Mesoporous Supports (SAMMS), for RCRA metal ion removal from aqueous wastewater and mercury removal from organic wastes such as vacuum pump oils is being developed at Pacific Northwest National Laboratory (PNNL). The six key features of the SAMMS technology are (1) large surface area (>900 m{sup 2}/g) of the mesoporous oxides (SiO{sub 2}, ZrO{sub 2}, TiO{sub 2}) ensures high capacity for metal loading (more than 1 g Hg/g SAMMS); (2) molecular recognition of the interfacial functional groups ensures the high affinity and selectivity for heavy metals without interference from other abundant cations (such as calcium and iron) in wastewater; (3) suitability for removal of mercury from both aqueous wastes and organic wastes; (4) the Hg-laden SAMMS not only pass TCLP tests, but also have good long-term durability as a waste form because the covalent binding between mercury and SAMMS has good resistance to ion exchange, oxidation, and hydrolysis; (5) the uniform and small pore size (2 to 40 nm) of the mesoporous silica prevents bacteria (>2000 nm) from solubilizing the bound mercury; and (6) SAMMS can also be used for RCRA metal removal from gaseous mercury waste, sludge, sediment, and soil.

Heavy metal driven co-selection of antibiotic resistance in soil and water bodies impacted by agriculture and aquaculture

OpenAIRE

Seiler, Claudia; Berendonk, Thomas U.

2012-01-01

The use of antibiotic agents as growth promoters was banned in animal husbandry to prevent the selection and spread of antibiotic resistance. However, in addition to antibiotic agents, heavy metals used in animal farming and aquaculture might promote the spread of antibiotic resistance via co-selection. To investigate which heavy metals are likely to co-select for antibiotic resistance in soil and water, the available data on heavy metal pollution, heavy metal toxicity, heavy metal tolerance ...

Dumpy-30 family members as determinants of male fertility and interaction partners of metal-responsive transcription factor 1 (MTF-1 in Drosophila

Directory of Open Access Journals (Sweden)

Renkawitz-Pohl Renate

2008-06-01

Full Text Available Abstract Background Metal-responsive transcription factor 1 (MTF-1, which binds to metal response elements (MREs, plays a central role in transition metal detoxification and homeostasis. A Drosophila interactome analysis revealed two candidate dMTF-1 interactors, both of which are related to the small regulatory protein Dumpy-30 (Dpy-30 of the worm C. elegans. Dpy-30 is the founding member of a protein family involved in chromatin modifications, notably histone methylation. Mutants affect mating type in yeast and male mating in C. elegans. Results Constitutive expression of the stronger interactor, Dpy-30L1 (CG6444, in transgenic flies inhibits MTF-1 activity and results in elevated sensitivity to Cd(II and Zn(II, an effect that could be rescued by co-overexpression of dMTF-1. Electrophoretic mobility shift assays (EMSA suggest that Dpy-30L1 interferes with the binding of MTF-1 to its cognate MRE binding site. Dpy-30L1 is expressed in the larval brain, gonads, imaginal discs, salivary glands and in the brain, testes, ovaries and salivary glands of adult flies. Expression of the second interactor, Dpy-30L2 (CG11591, is restricted to larval male gonads, and to the testes of adult males. Consistent with these findings, dpy-30-like transcripts are also prominently expressed in mouse testes. Targeted gene disruption by homologous recombination revealed that dpy-30L1 knockout flies are viable and show no overt disruption of metal homeostasis. In contrast, the knockout of the male-specific dpy-30L2 gene results in male sterility, as does the double knockout of dpy-30L1 and dpy-30L2. A closer inspection showed that Dpy-30L2 is expressed in elongated spermatids but not in early or mature sperm. Mutant sperm had impaired motility and failed to accumulate in sperm storage organs of females. Conclusion Our studies help to elucidate the physiological roles of the Dumpy-30 proteins, which are conserved from yeast to humans and typically act in concert with

Requirement of RIZ1 for Cancer Prevention by Methyl-Balanced Diet

Science.gov (United States)

Zhou, Wenyun; Alonso, Sergio; Takai, Daisaku; Lu, Shelly C.; Yamamoto, Fumiichiro; Perucho, Manuel; Huang, Shi

2008-01-01

Background The typical Western diet is not balanced in methyl nutrients that regulate the level of the methyl donor S-adenosylmethionine (SAM) and its derivative metabolite S-adenosylhomocysteine (SAH), which in turn may control the activity of certain methyltransferases. Feeding rodents with amino acid defined and methyl-imbalanced diet decreases hepatic SAM and causes liver cancers. RIZ1 (PRDM2 or KMT8) is a tumor suppressor and functions in transcriptional repression by methylating histone H3 lysine 9. Methodology/Principal Findings Here we show that a methyl-balanced diet conferred additional survival benefits compared to a tumor-inducing methyl-imbalanced diet only in mice with wild type RIZ1 but not in mice deficient in RIZ1. While absence of RIZ1 was tumorigenic in mice fed the balanced diet, its presence did not prevent tumor formation in mice fed the imbalanced diet. Microarray and gene expression analysis showed that, unlike most of its related enzymes, RIZ1 was upregulated by methyl-balanced diet. Methyl-balanced diet did not fully repress oncogenes such as c-Jun in the absence of RIZ1. Higher RIZ1 activity was associated with greater H3 lysine 9 methylation in RIZ1 target genes as shown by chromatin immunoprecipiation analysis. Conclusions/Significance The data identify RIZ1 as a critical target of methyl-balanced diet in cancer prevention. The molecular understanding of dietary carcinogenesis may help people make informed choices on diet, which may greatly reduce the incidence of cancer. PMID:18852888

Development of Metallic Fuels for Actinide Transmutation

Energy Technology Data Exchange (ETDEWEB)

Hayes, Steven Lowe [Idaho National Laboratory; Fielding, Randall Sidney [Idaho National Laboratory; Benson, Michael Timothy [Idaho National Laboratory; Chichester, Heather Jean MacLean [Idaho National Laboratory; Carmack, William Jonathan [Idaho National Laboratory

2015-09-01

and 60%. In general, the performance of all of these substantially disparate metallic fuel alloys has been observed to be excellent, and their irradiation behaviors are generally consistent with historic norms for metallic fuels without minor actinide additions and having lower Pu or Zr contents. Future work is being undertaken with a view toward increasing the burnup potential of metallic fuels even more. Design innovations under investigation include: 1) lowering the fuel smear density in order to accommodate more swelling, 2) annular fuel geometry to eliminate the need for a sodium bond, 3) minor alloy additions to stabilize lanthanide fission products inside the fuel and prevent their transport to the cladding where they can participate in fuel-cladding chemical interaction (FCCI), and 4) coatings/liners on the cladding inner surface to mitigate FCCI and enable higher temperature operation. This paper will present the current state of development of metallic fuels for actinide transmutation in the US. Highlights will include recent results from metallic fuel casting experiments, experiments to identify alloy additions to immobilize lanthanide fission products, and postirradiation examinations of annular metallic fuels at low burnup.

Photocatalytic properties of zinc sulfide nanocrystals biofabricated by metal-reducing bacterium Shewanella oneidensis MR-1

Energy Technology Data Exchange (ETDEWEB)

Xiao, Xiang [School of The Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013 (China); State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Ma, Xiao-Bo [School of The Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013 (China); Yuan, Hang [Key Laboratory of Ion Beam Bioengineering, Institute of Technical Biology & Agriculture Engineering, Chinese Academy of Sciences, Hefei 230031 (China); Liu, Peng-Cheng; Lei, Yu-Bin; Xu, Hui [School of The Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013 (China); Du, Dao-Lin, E-mail: ddl@ujs.edu.cn [School of The Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013 (China); State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Sun, Jian-Fan [School of The Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013 (China); Feng, Yu-Jie, E-mail: yujief@hit.edu.cn [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China)

2015-05-15

Highlights: • S. oneidensis MR-1 biofabricated ZnS nanocrystals using artificial wastewater. • ZnS nanocrystals were 5 nm in diameter and aggregated extracellularly. • ZnS had good catalytic activity in the degradation of RHB under UV irradiation. • Photogenerated holes mainly contributed to the degradation of RhB. - Abstract: Accumulation and utilization of heavy metals from wastewater by biological treatment system has aroused great interest. In the present study, a metal-reducing bacterium Shewanella oneidensis MR-1 was used to explore the biofabrication of ZnS nanocrystals from the artificial wastewater. The biogenic H{sub 2}S produced via the reduction of thiosulfate precipitated the Zn(II) as sulfide extracellularly. Characterization by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and field emission scanning electron microscope (FESEM) confirmed the precipitates as ZnS nanocrystals. The biogenic ZnS nanocrystals appeared spherical in shape with an average diameter of 5 nm and mainly aggregated in the medium and cell surface of S. oneidensis MR-1. UV–vis DRS spectra showed ZnS nanoparticles appeared a strong absorption below 360 nm. Thus, the photocatalytic activity of ZnS was evaluated by the photodegradation of rhodamine B (RhB) under UV irradiation. The biogenic ZnS nanocrystals showed a high level of photodegradation efficiency to RhB coupled with a significant blue-shift of maximum adsorption peak. A detailed analysis indicated the photogenerated holes, rather than hydroxyl radicals, contributed to the photocatalytic decolorization of RhB. This approach of coupling biosynthesis of nanoparticles with heavy metal removal may offer a potential avenue for efficient bioremediation of heavy metal wastewater.

Photocatalytic properties of zinc sulfide nanocrystals biofabricated by metal-reducing bacterium Shewanella oneidensis MR-1

International Nuclear Information System (INIS)

Xiao, Xiang; Ma, Xiao-Bo; Yuan, Hang; Liu, Peng-Cheng; Lei, Yu-Bin; Xu, Hui; Du, Dao-Lin; Sun, Jian-Fan; Feng, Yu-Jie

2015-01-01

Highlights: • S. oneidensis MR-1 biofabricated ZnS nanocrystals using artificial wastewater. • ZnS nanocrystals were 5 nm in diameter and aggregated extracellularly. • ZnS had good catalytic activity in the degradation of RHB under UV irradiation. • Photogenerated holes mainly contributed to the degradation of RhB. - Abstract: Accumulation and utilization of heavy metals from wastewater by biological treatment system has aroused great interest. In the present study, a metal-reducing bacterium Shewanella oneidensis MR-1 was used to explore the biofabrication of ZnS nanocrystals from the artificial wastewater. The biogenic H 2 S produced via the reduction of thiosulfate precipitated the Zn(II) as sulfide extracellularly. Characterization by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and field emission scanning electron microscope (FESEM) confirmed the precipitates as ZnS nanocrystals. The biogenic ZnS nanocrystals appeared spherical in shape with an average diameter of 5 nm and mainly aggregated in the medium and cell surface of S. oneidensis MR-1. UV–vis DRS spectra showed ZnS nanoparticles appeared a strong absorption below 360 nm. Thus, the photocatalytic activity of ZnS was evaluated by the photodegradation of rhodamine B (RhB) under UV irradiation. The biogenic ZnS nanocrystals showed a high level of photodegradation efficiency to RhB coupled with a significant blue-shift of maximum adsorption peak. A detailed analysis indicated the photogenerated holes, rather than hydroxyl radicals, contributed to the photocatalytic decolorization of RhB. This approach of coupling biosynthesis of nanoparticles with heavy metal removal may offer a potential avenue for efficient bioremediation of heavy metal wastewater

Prevention of Blast-Related Injuries

Science.gov (United States)

2017-09-01

in a canvas harness. The harness was further supported by a steel frame which was suspended from a metal beam (3.7 m off the ground) mounted on...direction of the wave propagation (Figure 5). After proper alignment of the head with respect to the center of the C4 charge, the steel frame was...further tied to four hooks cemented to the concrete ground with straps to prevent excessive motion during the blast exposure. The intensity of the two

Metal Stabilization of Collagen and de Novo Designed Mimetic Peptides.

Science.gov (United States)

Parmar, Avanish S; Xu, Fei; Pike, Douglas H; Belure, Sandeep V; Hasan, Nida F; Drzewiecki, Kathryn E; Shreiber, David I; Nanda, Vikas

2015-08-18

We explore the design of metal binding sites to modulate triple-helix stability of collagen and collagen-mimetic peptides. Globular proteins commonly utilize metals to connect tertiary structural elements that are well separated in sequence, constraining structure and enhancing stability. It is more challenging to engineer structural metals into fibrous protein scaffolds, which lack the extensive tertiary contacts seen in globular proteins. In the collagen triple helix, the structural adjacency of the carboxy-termini of the three chains makes this region an attractive target for introducing metal binding sites. We engineered His3 sites based on structural modeling constraints into a series of designed homotrimeric and heterotrimeric peptides, assessing the capacity of metal binding to improve stability and in the case of heterotrimers, affect specificity of assembly. Notable enhancements in stability for both homo- and heteromeric systems were observed upon addition of zinc(II) and several other metal ions only when all three histidine ligands were present. Metal binding affinities were consistent with the expected Irving-Williams series for imidazole. Unlike other metals tested, copper(II) also bound to peptides lacking histidine ligands. Acetylation of the peptide N-termini prevented copper binding, indicating proline backbone amide metal-coordination at this site. Copper similarly stabilized animal extracted Type I collagen in a metal-specific fashion, highlighting the potential importance of metal homeostasis within the extracellular matrix.

Corrosion resistant amorphous metals and methods of forming corrosion resistant amorphous metals

Science.gov (United States)

Farmer, Joseph C [Tracy, CA; Wong, Frank M. G. [Livermore, CA; Haslam, Jeffery J [Livermore, CA; Yang, Nancy [Lafayette, CA; Lavernia, Enrique J [Davis, CA; Blue, Craig A [Knoxville, TN; Graeve, Olivia A [Reno, NV; Bayles, Robert [Annandale, VA; Perepezko, John H [Madison, WI; Kaufman, Larry [Brookline, MA; Schoenung, Julie [Davis, CA; Ajdelsztajn, Leo [Walnut Creek, CA

2009-11-17

A system for coating a surface comprises providing a source of amorphous metal, providing ceramic particles, and applying the amorphous metal and the ceramic particles to the surface by a spray. The coating comprises a composite material made of amorphous metal that contains one or more of the following elements in the specified range of composition: yttrium (.gtoreq.1 atomic %), chromium (14 to 18 atomic %), molybdenum (.gtoreq.7 atomic %), tungsten (.gtoreq.1 atomic %), boron (.ltoreq.5 atomic %), or carbon (.gtoreq.4 atomic %).

Fatal chlorine gas exposure at a metal recycling facility: Case report.

Science.gov (United States)

Harvey, Robert R; Boylstein, Randy; McCullough, Joel; Shumate, Alice; Yeoman, Kristin; Bailey, Rachel L; Cummings, Kristin J

2018-06-01

At least four workers at a metal recycling facility were hospitalized and one died after exposure to chlorine gas when it was accidentally released from an intact, closed-valved cylinder being processed for scrap metal. This unintentional chlorine gas release marks at least the third such incident at a metal recycling facility in the United States since 2010. We describe the fatal case of the worker whose clinical course was consistent with acute respiratory distress syndrome (ARDS) following exposure to high concentrations of chlorine gas. This case report emphasizes the potential risk of chlorine gas exposure to metal recycling workers by accepting and processing intact, closed-valved containers. The metal recycling industry should take steps to increase awareness of this established risk to prevent future chlorine gas releases. Additionally, public health practitioners and clinicians should be aware that metal recycling workers are at risk for chlorine gas exposure. © 2018 Wiley Periodicals, Inc.

Heavy-metal-induced Inhibition of Aspergillus niger nitrate reductase: Applications for Rapid Contaminant Detection in Aqueous Samples

Energy Technology Data Exchange (ETDEWEB)

Apel, William Arnold; Aiken, Abigail Marie; Peyton, Brent Michael; Petersen, James N.

2003-03-01

Enzyme inhibition assays have the potential to rapidly screen and identify heavy metals in environmental samples. Inhibition of nitrate reductase (NR) was examined as a method for detecting toxic metals. The activity of NR (EC 1.6.6.2) from Aspergillus niger was assayed as a function of metal concentration in the presence of Cd2+, Cr3+, Cr6+, Cu2+, Ni2+, Pb2+, and Zn2+. NR exhibited sensitivity to these metals at concentrations below 10 µM. Various buffers were screened for their ability to protect NR activity from metal inhibition, and 3-(N-morpholino) propanesulfonic acid (MOPS) was selected as the buffering system for the NR assays as it exhibited the least interference with metal inhibition, thus providing increased assay sensitivity. The hypothesis that chelating agents could prevent the inhibition of NR activity by metal ions was also tested. Results indicated that 10 mM ethylenediaminetetraacetic acid (EDTA) could protect NR activity from inhibition by Cr3+, Cu2+, Cd2+, Ni2+, and Zn2+ at concentrations below 100 µM, but that the EDTA had no effect on NR inhibition by Cr6+. An amount of 10 mM nitrilotriacetic acid (NTA) prevented NR inhibition by Cd2+, Cu2+, Ni2+, Pb2+, and Zn2+ at metal concentrations below 100 µM. However, 10 mM NTA was unable to protect the enzyme from inhibition by either Cr3+ or Cr6+. These results indicated that through specific metal chelation, a NR-based method for individually quantifying Cr3+ and Cr6+ species in aqueous solutions could be developed. The ability to restore activity to NR which been previously inhibited by exposure to 100 µM Pb2+, Cd2+, Zn2+, Cu2+, and Cr3+ was explored to determine whether NR activity could be recovered by EDTA additions for use in consecutive metal inhibition assays. The results showed NR activity could not be regained after exposure to Cr3+ or Cu2+, but did partially recover activity after Cd2+, Pb2+, and Zn2+ exposure.

Spin-diffusion lengths in metals and alloys, and spin-flipping at metal/metal interfaces: an experimentalist's critical review

International Nuclear Information System (INIS)

Bass, Jack; Pratt, William P Jr

2007-01-01

In magnetoresistance (MR) studies of magnetic multilayers composed of combinations of ferromagnetic (F) and non-magnetic (N) metals, the magnetic moment (or related 'spin') of each conduction electron plays a crucial role, supplementary to that of its charge. While initial analyses of MR in such multilayers assumed that the direction of the spin of each electron stayed fixed as the electron transited the multilayer, we now know that this is true only in a certain limit. Generally, the spins 'flip' in a distance characteristic of the metal, its purity, and the temperature. They can also flip at F/N or N1/N2 interfaces. In this review we describe how to measure the lengths over which electron moments flip in pure metals and alloys, and the probability of spin-flipping at metallic interfaces. Spin-flipping within metals is described by a spin-diffusion length, l sf M , where the metal M F or N. Spin-diffusion lengths are the characteristic lengths in the current-perpendicular-to-plane (CPP) and lateral non-local (LNL) geometries that we focus upon in this review. In certain simple cases, l sf N sets the distance over which the CPP-MR and LNL-MR decrease as the N-layer thickness (CPP-MR) or N-film length (LNL) increases, and l sf F does the same for increase of the CPP-MR with increasing F-layer thickness. Spin-flipping at M1/M2 interfaces can be described by a parameter, δ M1/M2 , which determines the spin-flipping probability, P = 1-exp(-δ). Increasing δ M1/M2 usually decreases the MR. We list measured values of these parameters and discuss the limitations on their determinations. (topical review)

FINAL TAILINGS OF METAL-WORKING PRODUCTION. Part 3. PHYSICO-MECHANICAL CHARACTERISTICS

Directory of Open Access Journals (Sweden)

O. M. Djakonov

2011-01-01

Full Text Available The indices of adhesion and friability of metal-containing tailings, their water absorbency and wettability and also abrasive characteristics of tailings with the purpose of prevention of contacting surfaces wear are studied.

Metallated metal-organic frameworks

Energy Technology Data Exchange (ETDEWEB)

Bury, Wojciech; Farha, Omar K.; Hupp, Joseph T.; Mondloch, Joseph E.

2017-08-22

Porous metal-organic frameworks (MOFs) and metallated porous MOFs are provided. Also provided are methods of metallating porous MOFs using atomic layer deposition and methods of using the metallated MOFs as catalysts and in remediation applications.

Undoped Polyaniline/Surfactant Complex for the Corrosion Prevention

Science.gov (United States)

Liu, Lo-Min; Levon, Kalle

1998-01-01

Due to the strict regulations on the usage of heavy metals as the additives in the coating industries, the search for effective organic corrosion inhibitors in replace of those metal additives has become essential. Electrically conducting polymers have been shown to be effective for corrosion prevention but the poor solubility of these intractable polymers has been a problem. We have explored a polyaniline/4-dodecylphenol complex (PANi/DDPh) to improve the dissolution and it has been shown to be an effective organic corrosion inhibitor. With the surfactant, DDPh, PANi could be diluted into the coatings and the properties of the coatings were affected. Emeraldine base (EB) form of PANi was also found to be oxidized by the hardener. The oxidized form of polyaniline provides improved corrosion protection of metals than that of emeraldine base since the value of the standard electrode potential for the oxidized form of PANi is higher than that of EB. Additionally, the surfactant improves the wet adhesion property between the coating and the metal surface.

Safety in Academic Chemistry Laboratories: Volume 1. Accident Prevention for College and University Students, 7th Edition.

Science.gov (United States)

American Chemical Society, Washington, DC.

This book contains volume 1 of 2 and describes safety guidelines for academic chemistry laboratories to prevent accidents for college and university students. Contents include: (1) "Your Responsibility for Accident Prevention"; (2) "Guide to Chemical Hazards"; (3) "Recommended Laboratory Techniques"; and (4) "Safety Equipment and Emergency…

Option managing for radioactive metallic waste from the decommissioning of Kori Unit 1

Energy Technology Data Exchange (ETDEWEB)

Kessel, David S.; Kim, Chagn Lak [KEPCO International Nuclear Graduate School (KINGS), Ulsan (Korea, Republic of)

2017-06-15

The purpose of this paper is to evaluate several leading options for the management of radioactive metallic waste against a set of general criteria including safety, cost effectiveness, radiological dose to workers and volume reduction. Several options for managing metallic waste generated from decommissioning are evaluated in this paper. These options include free release, controlled reuse, and direct disposal of radioactive metallic waste. Each of these options may involve treatment of the metal waste for volume reduction by physical cutting or melting. A multi-criteria decision analysis was performed using the Analytic Hierarchy Process (AHP) to rank the options. Melting radioactive metallic waste to produce metal ingots with controlled reuse or free release is found to be the most effective option.

Transition metal-catalyzed couplings of alkynes to 1,3-enynes: modern methods and synthetic applications.

Science.gov (United States)

Trost, Barry M; Masters, James T

2016-04-21

The metal-catalyzed coupling of alkynes is a powerful method for the preparation of 1,3-enynes, compounds that are of broad interest in organic synthesis. Numerous strategies have been developed for the homo- and cross coupling of alkynes to enynes via transition metal catalysis. In such reactions, a major issue is the control of regio-, stereo-, and, where applicable, chemoselectivity. Herein, we highlight prominent methods for the selective synthesis of these valuable compounds. Further, we illustrate the utility of these processes through specific examples of their application in carbocycle, heterocycle, and natural product syntheses.

Species redistribution during solidification of nuclear fuel waste metal castings

Energy Technology Data Exchange (ETDEWEB)

Naterer, G F; Schneider, G E [Waterloo Univ., ON (Canada)

1994-12-31

An enthalpy-based finite element model and a binary system species redistribution model are developed and applied to problems associated with solidification of nuclear fuel waste metal castings. Minimal casting defects such as inhomogeneous solute segregation and cracks are required to prevent container corrosion and radionuclide release. The control-volume-based model accounts for equilibrium solidification for low cooling rates and negligible solid state diffusion for high cooling rates as well as intermediate conditions. Test problems involving nuclear fuel waste castings are investigated and correct limiting cases of species redistribution are observed. (author). 11 refs., 1 tab., 13 figs.

Uptake of heavy metals by Typha capensis from wetland sites polluted by effluent from mineral processing plants: implications of metal-metal interactions.

Science.gov (United States)

Zaranyika, M F; Nyati, W

2017-10-01

The aim of the present work was to demonstrate the existence of metal-metal interactions in plants and their implications for the absorption of toxic elements like Cr. Typha capensis , a good accumulator of heavy metals, was chosen for the study. Levels of Fe, Cr, Ni, Cd, Pb, Cu and Zn were determined in the soil and roots, rhizomes, stems and leaves of T. capensis from three Sites A, B and C polluted by effluent from a chrome ore processing plant, a gold ore processing plant, and a nickel ore processing plant, respectively. The levels of Cr were extremely high at Site A at 5415 and 786-16,047 μg g -1 dry weight in the soil and the plant, respectively, while the levels of Ni were high at Site C at 176 and 24-891 μg g -1 in the soil and the plant, respectively. The levels of Fe were high at all three sites at 2502-7500 and 906-13,833 μg g -1 in the soil and plant, respectively. For the rest of the metals, levels were modest at 8.5-148 and 2-264 μg g -1 in the soil and plant, respectively. Pearson's correlation analysis confirmed mutual synergistic metal-metal interactions in the uptake of Zn, Cu, Co, Ni, Fe, and Cr, which are attributed to the similarity in the radii and coordination geometry of the cations of these elements. The implications of such metal-metal interactions (or effects of one metal on the behaviour of another) on the uptake of Cr, a toxic element, and possible Cr detoxification mechanism within the plant, are discussed.

Combining Nitrilotriacetic Acid and Permeable Barriers for Enhanced Phytoextraction of Heavy Metals from Municipal Solid Waste Compost by and Reduced Metal Leaching.

Science.gov (United States)

Zhao, Shulan; Jia, Lina; Duo, Lian

2016-05-01

Phytoextraction has the potential to remove heavy metals from contaminated soil, and chelants can be used to improve the capabilities of phytoextraction. However, environmentally persistent chelants can cause metal leaching and groundwater pollution. A column experiment was conducted to evaluate the viability of biodegradable nitrilotriacetic acid (NTA) to increase the uptake of heavy metals (Cd, Cr, Ni, Pb, Cu, and Zn) by L. in municipal solid waste (MSW) compost and to evaluate the effect of two permeable barrier materials, bone meal and crab shell, on metal leaching. The application of NTA significantly increased the concentrations and uptake of heavy metals in . The enhancement was more pronounced at higher dosages of NTA. In the 15 mmol kg NTA treatment using a crab shell barrier, the Cr and Ni concentrations in the plant shoots increased by approximately 8- and 10-fold, respectively, relative to the control. However, the addition of NTA also caused significant heavy metal leaching from the MSW compost. Bone meal and crab shell barriers positioned between the compost and the subsoil were effective in preventing metal leaching down through the soil profile by the retention of metals in the barrier. The application of a biodegradable chelant and the use of permeable barriers is a viable form of enhanced phytoextraction to increase the removal of metals and to reduce possible leaching. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Surface Termination of the Metal-Organic Framework HKUST-1: A Theoretical Investigation.

Science.gov (United States)

Amirjalayer, Saeed; Tafipolsky, Maxim; Schmid, Rochus

2014-09-18

The surface morphology and termination of metal-organic frameworks (MOF) is of critical importance in many applications, but the surface properties of these soft materials are conceptually different from those of other materials like metal or oxide surfaces. Up to now, experimental investigations are scarce and theoretical simulations have focused on the bulk properties. The possible surface structure of the archetypal MOF HKUST-1 is investigated by a first-principles derived force field in combination with DFT calculations of model systems. The computed surface energies correctly predict the [111] surface to be most stable and allow us to obtain an unprecedented atomistic picture of the surface termination. Entropic factors are identified to determine the preferred surface termination and to be the driving force for the MOF growth. On the basis of this, reported strategies like employing "modulators" during the synthesis to tailor the crystal morphology are discussed.

Heavy metal extraction from PCB wastewater treatment sludge by sulfuric acid

International Nuclear Information System (INIS)

Kuan, Yu-Chung; Lee, I-Hsien; Chern, Jia-Ming

2010-01-01

Heavy metals contaminated wastewater sludge is classified as hazardous solid waste and needs to be properly treated to prevent releasing heavy metals to the environment. In this study, the wastewater treatment sludge from a printed circuit board manufacturing plant was treated in a batch reactor by sulfuric acid to remove the contained heavy metals. The effects of sulfuric acid concentration and solid to liquid ratio on the heavy metal removal efficiencies were investigated. The experimental results showed that the total and individual heavy metal removal efficiencies increased with increasing sulfuric acid concentration, but decreased with increasing solid to liquid ratio. A mathematical model was developed to predict the residual sludge weights at varying sulfuric concentrations and solid to liquid ratios. The trivalent heavy metal ions, iron and chromium were more difficult to be removed than the divalent ions, copper, zinc, nickel, and cadmium. For 5 g/L solid to liquid ratio, more than 99.9% of heavy metals can be removed from the sludge by treating with 0.5 M sulfuric acid in 2 h.

Accelerating Industrial Adoption of Metal Additive Manufacturing Technology

Science.gov (United States)

Vartanian, Kenneth; McDonald, Tom

2016-03-01

While metal additive manufacturing (AM) technology has clear benefits, there are still factors preventing its adoption by industry. These factors include the high cost of metal AM systems, the difficulty for machinists to learn and operate metal AM machines, the long approval process for part qualification/certification, and the need for better process controls; however, the high AM system cost is the main barrier deterring adoption. In this paper, we will discuss an America Makes-funded program to reduce AM system cost by combining metal AM technology with conventional computerized numerical controlled (CNC) machine tools. Information will be provided on how an Optomec-led team retrofitted a legacy CNC vertical mill with laser engineered net shaping (LENS®—LENS is a registered trademark of Sandia National Labs) AM technology, dramatically lowering deployment cost. The upgraded system, dubbed LENS Hybrid Vertical Mill, enables metal additive and subtractive operations to be performed on the same machine tool and even on the same part. Information on the LENS Hybrid system architecture, learnings from initial system deployment and continuing development work will also be provided to help guide further development activities within the materials community.

Diabetic subjects diagnosed through the Diabetes Prevention Trial-Type 1 (DPT-1) are often asymptomatic with normal A1C at diabetes onset.

Science.gov (United States)

Triolo, Taylor M; Chase, H Peter; Barker, Jennifer M

2009-05-01

Upon diagnosis of type 1 diabetes, patients are usually symptomatic, and many have ketoacidosis. Screening for islet autoantibodies (IAs) has been shown to decrease A1C level and rate of hospitalization at diabetes onset. Metabolic tests and the presence of symptoms were described at diabetes onset during the Diabetes Prevention Trial-Type 1 (DPT-1). The DPT-1 screened relatives of patients with type 1 diabetes for islet cell autoantiobodies (ICAs). Those with positive ICAs had intravenous and oral glucose tolerance tests (IVGTTs and OGTTs) and were randomized into one of two prevention trials. Throughout the DPT-1 parenteral and oral insulin study, 246 people were diagnosed with type 1 diabetes. Of the 246 subjects diagnosed with diabetes, 218 had data regarding the presence of symptoms, and 138 (63.3%) reported no symptoms suggestive of diabetes. Eight subjects (3.67%) presented with ketosis. Subjects presented with a mean +/- SD A1C of 6.41 +/- 1.15%. At diagnosis, 90 subjects (50.8%) had A1C in the normal range (IA followed by OGTT) may allow diagnosis of diabetes before severe metabolic decompensation. Screening with A1C will miss identifying many of the subjects with newly diagnosed type 1 diabetes in this cohort.

Antiretroviral pre-exposure prophylaxis prevents vaginal transmission of HIV-1 in humanized BLT mice.

Directory of Open Access Journals (Sweden)

Paul W Denton

2008-01-01

Full Text Available Worldwide, vaginal transmission now accounts for more than half of newly acquired HIV-1 infections. Despite the urgency to develop and implement novel approaches capable of preventing HIV transmission, this process has been hindered by the lack of adequate small animal models for preclinical efficacy and safety testing. Given the importance of this route of transmission, we investigated the susceptibility of humanized mice to intravaginal HIV-1 infection.We show that the female reproductive tract of humanized bone marrow-liver-thymus (BLT mice is reconstituted with human CD4+ T and other relevant human cells, rendering these humanized mice susceptible to intravaginal infection by HIV-1. Effects of HIV-1 infection include CD4+ T cell depletion in gut-associated lymphoid tissue (GALT that closely mimics what is observed in HIV-1-infected humans. We also show that pre-exposure prophylaxis with antiretroviral drugs is a highly effective method for preventing vaginal HIV-1 transmission. Whereas 88% (7/8 of BLT mice inoculated vaginally with HIV-1 became infected, none of the animals (0/5 given pre-exposure prophylaxis of emtricitabine (FTC/tenofovir disoproxil fumarate (TDF showed evidence of infection (Chi square = 7.5, df = 1, p = 0.006.The fact that humanized BLT mice are susceptible to intravaginal infection makes this system an excellent candidate for preclinical evaluation of both microbicides and pre-exposure prophylactic regimens. The utility of humanized mice to study intravaginal HIV-1 transmission is particularly highlighted by the demonstration that pre-exposure prophylaxis can prevent intravaginal HIV-1 transmission in the BLT mouse model.

Liquid-metal dip seal with pneumatic spring

International Nuclear Information System (INIS)

Poindexter, A.M.

1977-01-01

An improved liquid-metal dip seal for sealing the annulus between rotating plugs in the reactor vessel head of a liquid-metal fast-breeder nuclear reactor has two legs of differing widths communicating under a seal blade; the wide leg is also in communication with cover gas of the reactor and the narrow leg is also in communication with an isolated plug annulus above the seal. The annulus contains inert gas which acts as a pneumatic spring. Upon increasing cover gas pressure which depresses the level in the wide leg and greatly increases the level in the narrow leg, the pneumatic spring is compressed, and resists further level changes, thus preventing radioactive cover gas from bubbling through the seal

Spirulina maxima extract prevents cell death through BDNF activation against amyloid beta 1-42 (Aβ1-42) induced neurotoxicity in PC12 cells.

Science.gov (United States)

Koh, Eun-Jeong; Kim, Kui-Jin; Choi, Jia; Kang, Do-Hyung; Lee, Boo-Yong

2018-04-23

Spirulina maxima is a blue-green micro alga that contains abundant amounts of proteins (60-70%), vitamins, chlorophyll a, and C-phycocyanin (C-PC). It has been shown to reduce oxidative stress, and prevent diabetes and non-alcoholic fatty liver disease. However, it is unclear whether Spirulina maxima 70% ethanol extract (SM70EE), chlorophyll a, and C-PC prevent Aβ 1-42 -induced neurotoxicity in PC12 cells. The aim of this study was to investigate whether SM70EE, chlorophyll a, and C-PC prevent Aβ 1-42 -induced cell death. SM70EE, chlorophyll a, and C-PC suppressed the Aβ 1-42 -induced increase in poly-ADP ribose polymerase-1 (PARP-1) cleavage and reduced Aβ 1-42 -induced decreases in glutathione and its associated factors. The level of brain-derived neurotrophic factor (BDNF), which plays a critical role in neuronal survival and neuroprotection, was increased by SM70EE, chlorophyll a, and C-PC in Aβ 1-42 -treated cells. SM70EE treatment decreased oxidative stress and cell death in response to Aβ 1-42 treatment, while simultaneously suppressing PARP cleavage and increasing the levels of glutathione (GSH) and its associated factors. Moreover, SM70EE lowered the levels of APP and BACE1, two major factors involved in APP processing, and increased BDNF expression during Aβ 1-42 -induced neurotoxicity in PC12 cells. We suggest that SM70EE prevents cell death caused by Aβ 1-42 -induced neurotoxicity via the activation of BDNF signaling. Copyright © 2018 Elsevier B.V. All rights reserved.

Influence of heavy metals in non-anthropized soils with high levels of primordial radionuclides

International Nuclear Information System (INIS)

Bezerra, Jairo Dias; Amaral, Romilton dos Santos; Santos Junior, Jose Araujo dos; Rocha, Edilson Accioly; Oliveira, Jose Valdez Monterazo de; Bispo, Rodrigo Cesar Bezerra

2011-01-01

High concentrations of heavy metals in the ecosystem depend naturally geological formation in each area of the planet and of anthropic activities that contribute to contamination of soil, water sources and food produced in these areas. In this context, we highlight the importance in the study of As, Cr and Ba because of the level of toxicity, availability and chemical speciation that have. The study area was chosen to present agricultural activity and milk production on a large scale. This area is located in the rugged region of the state of Pernambuco, in the town of stone, where the arable soil was monitored aiming to determine the levels of these metals. Analyses were performed by the technique of neutron activation analysis coupled with the high-resolution gamma spectrometry. Were analyzed twenty-three soil samples collected from the horizon C. The results obtained varied from values smaller that (0.2 to 6.7) mg.kg -1 for As; (12.1 to 65.5) mg.kg -1 for Cr and (443 a 1,497) mg.kg -1 for Ba. Comparing them with the values established by CONAMA Resolution 420/2009, it was found that the concentrations of Ba are 100% above the value of prevention, and approximately 91% of values above the intervention value. The As and Cr showed 100% of results below the value of prevention. Whereas the study area has no industrial activity, high concentrations are determined for the Ba from natural processes. For the levels found evidence of a possible contamination of water sources and food produced in this region. (author)

Effects of gamma-ray-induced free radicals on the metal content and amino acid composition of human metallothionein-1

International Nuclear Information System (INIS)

Goossens, Lieven

2011-01-01

Metallothioneins (MTs), a low-mass class of metalloproteins, are characterized by a high thiolate sulphur and metal content. MTs are involved in metal homeostasis and heavy metal detoxification, and are efficient scavengers of free radicals. This article describes zinc release from human MT-1 and modification of its amino acid composition when subjected to free radicals generated during gamma ray radiolysis. The effect of gamma ray radiolysis of untreated and metal-depleted human MT-1 was tested under multiple aerobic and anaerobic conditions at increasing irradiation doses. Under all conditions, a rapid increase of serine in the early stages of irradiation was observed. Irradiation for longer times led to cysteic acid formation, except under argon atmosphere. Several other amino acid concentrations gradually decreased. Formation of limited amounts of hydroxyproline, hydroxylysine and ornithine as well as some less common derivatives such as cystathionine occurred as side-effects. (author)

Chemoelectronic circuits based on metal nanoparticles

Science.gov (United States)

Yan, Yong; Warren, Scott C.; Fuller, Patrick; Grzybowski, Bartosz A.

2016-07-01

To develop electronic devices with novel functionalities and applications, various non-silicon-based materials are currently being explored. Nanoparticles have unique characteristics due to their small size, which can impart functions that are distinct from those of their bulk counterparts. The use of semiconductor nanoparticles has already led to improvements in the efficiency of solar cells, the processability of transistors and the sensitivity of photodetectors, and the optical and catalytic properties of metal nanoparticles have led to similar advances in plasmonics and energy conversion. However, metals screen electric fields and this has, so far, prevented their use in the design of all-metal nanoparticle circuitry. Here, we show that simple electronic circuits can be made exclusively from metal nanoparticles functionalized with charged organic ligands. In these materials, electronic currents are controlled by the ionic gradients of mobile counterions surrounding the ‘jammed’ nanoparticles. The nanoparticle-based electronic elements of the circuitry can be interfaced with metal nanoparticles capable of sensing various environmental changes (humidity, gas, the presence of various cations), creating electronic devices in which metal nanoparticles sense, process and ultimately report chemical signals. Because the constituent nanoparticles combine electronic and chemical sensing functions, we term these systems ‘chemoelectronic’. The circuits have switching times comparable to those of polymer electronics, selectively transduce parts-per-trillion chemical changes into electrical signals, perform logic operations, consume little power (on the scale of microwatts), and are mechanically flexible. They are also ‘green’, in the sense that they comprise non-toxic nanoparticles cast at room temperature from alcohol solutions.

1-D Metal Nanobead Arrays within Encapsulated Nanowires via a Red-Ox-Induced Dewetting: Mechanism Study by Atom-Probe Tomography.

Science.gov (United States)

Sun, Zhiyuan; Tzaguy, Avra; Hazut, Ori; Lauhon, Lincoln J; Yerushalmi, Roie; Seidman, David N

2017-12-13

Metal nanoparticle arrays are excellent candidates for a variety of applications due to the versatility of their morphology and structure at the nanoscale. Bottom-up self-assembly of metal nanoparticles provides an important complementary alternative to the traditional top-down lithography method and makes it possible to assemble structures with higher-order complexity, for example, nanospheres, nanocubes, and core-shell nanostructures. Here we present a mechanism study of the self-assembly process of 1-D noble metal nanoparticles arrays, composed of Au, Ag, and AuAg alloy nanoparticles. These are prepared within an encapsulated germanium nanowire, obtained by the oxidation of a metal-germanium nanowire hybrid structure. The resulting structure is a 1-D array of equidistant metal nanoparticles with the same diameter, the so-called nanobead (NB) array structure. Atom-probe tomography and transmission electron microscopy were utilized to investigate the details of the morphological and chemical evolution during the oxidation of the encapsulated metal-germanium nanowire hybrid-structures. The self-assembly of nanoparticles relies on the formation of a metal-germanium liquid alloy and the migration of the liquid alloy into the nanowire, followed by dewetting of the liquid during shape-confined oxidation where the liquid column breaks-up into nanoparticles due to the Plateau-Rayleigh instability. Our results demonstrate that the encapsulating oxide layer serves as a structural scaffold, retaining the overall shape during the eutectic liquid formation and demonstrates the relationship between the oxide mechanical properties and the final structural characteristics of the 1-D arrays. The mechanistic details revealed here provide a versatile tool-box for the bottom-up fabrication of 1-D arrays nanopatterning that can be modified for multiple applications according to the RedOx properties of the material system components.

[Transcatheter embolization for huge pulmonary arteriovenous fistula using metallic "spider" and spring embolus--application of hand-made metallic "spider" using partial monorail technique].

Science.gov (United States)

Hirota, S; Sako, M; Fujita, Y; Hasegawa, Y; Sugimoto, K; Suzuki, Y; Kono, M

1992-07-25

We performed transcatheter embolization in two cases with huge pulmonary arteriovenous fistula (AVF) using a metallic "spider" and spring embolus. Conventional spring embolus or detachable balloon could not be used in these cases. Metallic spider was indicated for pulmonary AVF with a feeding artery diameter of more than 16 mm to prevent embolus passing through the AVF. In the first case, we used large handmade metallic spiders of 25 mm in diameter followed by embolization by numerous spring coils. At that time, a partial monorail technique was newly devised to carry the large metallic spider into the feeding artery, otherwise the spider could not pass into a 9F catheter. After embolization, symptoms and PaO2 in arterial blood improved remarkably in both cases. In the second case, a spring coil migrated into the normal pulmonary artery, but no infarction resulted. In conclusion, the metallic spider was very useful for embolization of hugee pulmonary AVF to avoid the embolus passing through and to tangle spring coils together with it. If commercially available "spiders" are too small, ones can be made easily.

Weld metal resistant to neutron-bombardment embrittlement

International Nuclear Information System (INIS)

Biemiller, E.C.

1980-01-01

The object of the invention is the provision of a broad range of weldments for reactor pressure vessels that exhibit resistance to neutron-induced changes sufficient to prevent the weldments from being limiting factors in reactor operation. The weld materials of the present invention are defined by as deposited weight percentages in the following ranges: carbon 0.00-0.l5, manganese 1.00 - 2.20, phosphorus 0.000 - 0.015, sulfur 0.00 - 0.02, silicon 0.00 - 0.40, nickel 0.00 - 1.20, chromium 0.00 - 2.50, molybdenum 0.30 - 1.20, copper 0.00 - 0.10, vanadium 0.00 - 0.15, balance essentially iron. A further constraint is that, in its deposited state, A/B <0.4, where A is the sum of the weight percents of nickel and silicon in the metal and B is the sum of the weight percents of manganese, chromium, and molybdenum. (LL)

Inorganic metal settlement in fuel tanks and their environmental effect for disposal

International Nuclear Information System (INIS)

Malana, M.A.; Nadeem, M.

2000-01-01

Air-quality or, more precisely, the health and environmental consequences of poor air-quality are currently the center of great deal of attention from media, pressure groups and government. Usage of petroleum-sludge, after its disposal, is also a cause of air pollution. The sludge is generally used for burning small local industrial and brick-kilns, without any preventive measures. This study is based on the estimation of trace-metal concentrations in petroleum sludge, which are emitting sulphur and metal contents into the environment, unknowingly. It is also noted that the concentration-ratio of metal-contents is higher in sludge samples. (author)

Waste minimization and pollution prevention awareness plan. Revision 1

International Nuclear Information System (INIS)

1994-07-01

The purpose of this plan is to document Lawrence Livermore National Laboratory (LLNL) projections for present and future waste minimization and pollution prevention. The plan specifies those activities and methods that are or will be used to reduce the quantity and toxicity of wastes generated at the site. It is intended to satisfy Department of Energy (DOE) requirements. This Waste Minimization and Pollution Prevention Awareness Plan provides an overview of projected activities from FY 1994 through FY 1999. The plans are broken into site-wide and problem-specific activities. All directorates at LLNL have had an opportunity to contribute input, estimate budgets, and review the plan. In addition to the above, this plan records LLNL's goals for pollution prevention, regulatory drivers for those activities, assumptions on which the cost estimates are based, analyses of the strengths of the projects, and the barriers to increasing pollution prevention activities

The use of intermediate endpoints in the design of type 1 diabetes prevention trials.

Science.gov (United States)

Krischer, Jeffrey P

2013-09-01

This paper presents a rationale for the selection of intermediate endpoints to be used in the design of type 1 diabetes prevention clinical trials. Relatives of individuals diagnosed with type 1 diabetes were enrolled on the TrialNet Natural History Study and screened for diabetes-related autoantibodies. Those with two or more such autoantibodies were analysed with respect to increased HbA1c, decreased C-peptide following an OGTT, or abnormal OGTT values as intermediate markers of disease progression. Over 2 years, a 10% increase in HbA1c, and a 20% or 30% decrease in C-peptide from baseline, or progression to abnormal OGTT, occurred with a frequency between 20% and 41%. The 3- to 5-year risk of type 1 diabetes following each intermediate endpoint was high, namely 47% to 84%. The lower the incidence of the endpoint being reached, the higher the risk of diabetes. A diabetes prevention trial using these intermediate endpoints would require a 30% to 50% smaller sample size than one using type 1 diabetes as the endpoint. The use of an intermediate endpoint in diabetes prevention is based on the generally held view of disease progression from initial occurrence of autoantibodies through successive immunological and metabolic changes to manifest type 1 diabetes. Thus, these markers are suitable for randomised phase 2 trials, which can more rapidly screen promising new therapies, allowing them to be subsequently confirmed in definitive phase 3 trials.

Genetic variation in metallothionein and metal-regulatory transcription factor 1 in relation to urinary cadmium, copper, and zinc

International Nuclear Information System (INIS)

Adams, Scott V.; Barrick, Brian; Christopher, Emily P.; Shafer, Martin M.; Makar, Karen W.; Song, Xiaoling; Lampe, Johanna W.; Vilchis, Hugo; Ulery, April; Newcomb, Polly A.

2015-01-01

Background: Metallothionein (MT) proteins play critical roles in the physiological handling of both essential (Cu and Zn) and toxic (Cd) metals. MT expression is regulated by metal-regulatory transcription factor 1 (MTF1). Hence, genetic variation in the MT gene family and MTF1 might influence excretion of these metals. Methods: 321 women were recruited in Seattle, WA and Las Cruces, NM and provided demographic information, urine samples for measurement of metal concentrations by mass spectrometry and creatinine, and blood or saliva for extraction of DNA. Forty-one single nucleotide polymorphisms (SNPs) within the MTF1 gene region and the region of chromosome 16 encoding the MT gene family were selected for genotyping in addition to an ancestry informative marker panel. Linear regression was used to estimate the association of SNPs with urinary Cd, Cu, and Zn, adjusted for age, urinary creatinine, smoking history, study site, and ancestry. Results: Minor alleles of rs28366003 and rs10636 near the MT2A gene were associated with lower urinary Cd, Cu, and Zn. Minor alleles of rs8044719 and rs1599823, near MT1A and MT1B, were associated with lower urinary Cd and Zn, respectively. Minor alleles of rs4653329 in MTF1 were associated with lower urinary Cd. Conclusions: These results suggest that genetic variation in the MT gene region and MTF1 influences urinary Cd, Cu, and Zn excretion. - Highlights: • Genetic variation in metallothionein (MT) genes was assessed in two diverse populations. • Single nucleotide polymorphisms (SNPs) in MT genes were associated with mean urinary Cd, Cu and Zn. • Genetic variation may influence biomarkers of exposure, and associations of exposure with health.

Genetic variation in metallothionein and metal-regulatory transcription factor 1 in relation to urinary cadmium, copper, and zinc

Energy Technology Data Exchange (ETDEWEB)

Adams, Scott V., E-mail: sadams@fhcrc.org [Public Health Sciences Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, Seattle, WA 98109 (United States); Barrick, Brian [Department of Plant and Environmental Sciences, New Mexico State University, Box 30003 MSC 3Q, Las Cruces, NM 88003 (United States); Christopher, Emily P. [Public Health Sciences Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, Seattle, WA 98109 (United States); Shafer, Martin M. [Environmental Chemistry and Technology, Wisconsin State Laboratory of Hygiene, University of Wisconsin, 2601 Agriculture Dr., Madison, WI 53718 (United States); Makar, Karen W.; Song, Xiaoling [Public Health Science Biomarker Laboratory, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, Seattle, WA 98109 (United States); Lampe, Johanna W. [Public Health Sciences Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, Seattle, WA 98109 (United States); Vilchis, Hugo [Border Epidemiology and Environmental Health Center, New Mexico State University, Box 30001 MSC 3BEC, Las Cruces, NM 88003 (United States); Ulery, April [Department of Plant and Environmental Sciences, New Mexico State University, Box 30003 MSC 3Q, Las Cruces, NM 88003 (United States); Newcomb, Polly A. [Public Health Sciences Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, Seattle, WA 98109 (United States)

2015-12-15

Background: Metallothionein (MT) proteins play critical roles in the physiological handling of both essential (Cu and Zn) and toxic (Cd) metals. MT expression is regulated by metal-regulatory transcription factor 1 (MTF1). Hence, genetic variation in the MT gene family and MTF1 might influence excretion of these metals. Methods: 321 women were recruited in Seattle, WA and Las Cruces, NM and provided demographic information, urine samples for measurement of metal concentrations by mass spectrometry and creatinine, and blood or saliva for extraction of DNA. Forty-one single nucleotide polymorphisms (SNPs) within the MTF1 gene region and the region of chromosome 16 encoding the MT gene family were selected for genotyping in addition to an ancestry informative marker panel. Linear regression was used to estimate the association of SNPs with urinary Cd, Cu, and Zn, adjusted for age, urinary creatinine, smoking history, study site, and ancestry. Results: Minor alleles of rs28366003 and rs10636 near the MT2A gene were associated with lower urinary Cd, Cu, and Zn. Minor alleles of rs8044719 and rs1599823, near MT1A and MT1B, were associated with lower urinary Cd and Zn, respectively. Minor alleles of rs4653329 in MTF1 were associated with lower urinary Cd. Conclusions: These results suggest that genetic variation in the MT gene region and MTF1 influences urinary Cd, Cu, and Zn excretion. - Highlights: • Genetic variation in metallothionein (MT) genes was assessed in two diverse populations. • Single nucleotide polymorphisms (SNPs) in MT genes were associated with mean urinary Cd, Cu and Zn. • Genetic variation may influence biomarkers of exposure, and associations of exposure with health.

Control of Orphan Sources and Other Radioactive Material in the Metal Recycling and Production Industries. Specific Safety Guide (Arabic Edition)

Energy Technology Data Exchange (ETDEWEB)

NONE

2014-09-01

Accidents involving orphan sources and other radioactive material in the metal recycling and production industries have resulted in serious radiological accidents as well as in harmful environmental, social and economic impacts. This Safety Guide provides recommendations, the implementation of which should prevent such accidents and provide confidence that scrap metal and recycled products are safe. Contents: 1. Introduction; 2. Protection of people and the environment; 3. Responsibilities; 4. Monitoring for radioactive material; 5. Response to the discovery of radioactive material; 6. Remediation of contaminated areas; 7. Management of recovered radioactive material; Annex I: Review of events involving radioactive material in the metal recycling and production industries; Annex II: Categorization of radioactive sources; Annex III: Some examples of national and international initiatives.

Control of Orphan Sources and Other Radioactive Material in the Metal Recycling and Production Industries. Specific Safety Guide (Arabic Edition)

International Nuclear Information System (INIS)

2014-01-01

Accidents involving orphan sources and other radioactive material in the metal recycling and production industries have resulted in serious radiological accidents as well as in harmful environmental, social and economic impacts. This Safety Guide provides recommendations, the implementation of which should prevent such accidents and provide confidence that scrap metal and recycled products are safe. Contents: 1. Introduction; 2. Protection of people and the environment; 3. Responsibilities; 4. Monitoring for radioactive material; 5. Response to the discovery of radioactive material; 6. Remediation of contaminated areas; 7. Management of recovered radioactive material; Annex I: Review of events involving radioactive material in the metal recycling and production industries; Annex II: Categorization of radioactive sources; Annex III: Some examples of national and international initiatives

Control of Orphan Sources and Other Radioactive Material in the Metal Recycling and Production Industries. Specific Safety Guide (Spanish Edition)

International Nuclear Information System (INIS)

2013-01-01

Accidents involving orphan sources and other radioactive material in the metal recycling and production industries have resulted in serious radiological accidents as well as in harmful environmental, social and economic impacts. This Safety Guide provides recommendations, the implementation of which should prevent such accidents and provide confidence that scrap metal and recycled products are safe. Contents: 1. Introduction; 2. Protection of people and the environment; 3. Responsibilities; 4. Monitoring for radioactive material; 5. Response to the discovery of radioactive material; 6. Remediation of contaminated areas; 7. Management of recovered radioactive material; Annex I: Review of events involving radioactive material in the metal recycling and production industries; Annex II: Categorization of radioactive sources; Annex III: Some examples of national and international initiatives

dAdd1 and dXNP prevent genome instability by maintaining HP1a localization at Drosophila telomeres.

Science.gov (United States)

Chavez, Joselyn; Murillo-Maldonado, Juan Manuel; Bahena, Vanessa; Cruz, Ana Karina; Castañeda-Sortibrán, América; Rodriguez-Arnaiz, Rosario; Zurita, Mario; Valadez-Graham, Viviana

2017-12-01

Telomeres are important contributors to genome stability, as they prevent linear chromosome end degradation and contribute to the avoidance of telomeric fusions. An important component of the telomeres is the heterochromatin protein 1a (HP1a). Mutations in Su(var)205, the gene encoding HP1a in Drosophila, result in telomeric fusions, retrotransposon regulation loss and larger telomeres, leading to chromosome instability. Previously, it was found that several proteins physically interact with HP1a, including dXNP and dAdd1 (orthologues to the mammalian ATRX gene). In this study, we found that mutations in the genes encoding the dXNP and dAdd1 proteins affect chromosome stability, causing chromosomal aberrations, including telomeric defects, similar to those observed in Su(var)205 mutants. In somatic cells, we observed that dXNP and dAdd1 participate in the silencing of the telomeric HTT array of retrotransposons, preventing anomalous retrotransposon transcription and integration. Furthermore, the lack of dAdd1 results in the loss of HP1a from the telomeric regions without affecting other chromosomal HP1a binding sites; mutations in dxnp also affected HP1a localization but not at all telomeres, suggesting a specialized role for dAdd1 and dXNP proteins in locating HP1a at the tips of the chromosomes. These results place dAdd1 as an essential regulator of HP1a localization and function in the telomere heterochromatic domain.

Revision rates for metal-on-metal hip resurfacing and metal-on-metal total hip arthroplasty – a systematic review

DEFF Research Database (Denmark)

Ras Sørensen, Sofie-amalie L.; Jørgensen, Henrik L.; Sporing, Sune L.

2016-01-01

Purpose To compare revision rates of metal-on-metal (MoM) hip resurfacing (HRS) and MoM total hip arthroplasty (THA), as well as the primary causes for revisions. Methods The PubMed database was queried for potentially relevant articles addressing MoMTHA and MoMHRS, a total of 51 articles were....... The odds ratio was 1.25 (1.03:1.53) 95% CI (p = 0.03) (MoMHRS vs. MoMTHA). The studies of hip prostheses were separated into 2 categories of short- and long-term (more or less than 5 years). Short-term revision rate for MoMTHA was 4.5% after 4.8 years, and for MoMHRS 4.0% after 4.2 years. The odds ratio...

Optimization of Sintering Time and Holding Time for 3D Printing of Fe-Based Metallic Glasses

Directory of Open Access Journals (Sweden)

Wenzheng Wu

2018-06-01

Full Text Available Fe-based metallic glasses are amorphous alloys with high strength, high hardness, and excellent corrosion resistance; however, the immaturity of processing methods has prevented their wide application in industrial production. Fe-based metallic glass parts were manufactured employing pneumatic injection additive manufacturing in this study. An evenly dispersed and stable Fe-based metallic glass powder slurry with a solids content of 50% was prepared firstly. Then the Fe-based metallic glass parts were printed. The printed parts were dried, debinded, and sintered for strengthening. The deformations of the printed parts and sintered parts relative to the original model were then analyzed by a 3D scanning reconstruction method. The slightly average bulging and sunken deformation of the printed parts and sintered parts confirmed the good printing accuracy of the pneumatic injection manufacture system. The effects of the sintering temperature and holding time on the properties of the sintered parts were studied. For a sintering temperature of 580 °C and holding time of 1 h, the surface quality of the sintered parts was better. The sintering of 3D-printed Fe-based metallic glass parts was preliminarily realized in this study, and the feasibility of preparing Fe-based metallic glass using pneumatic injection additive manufacture was verified.

Evaluation of the effect of divalent metal transporter 1 gene polymorphism on blood iron, lead and cadmium levels

Energy Technology Data Exchange (ETDEWEB)

Kayaaltı, Zeliha, E-mail: kayaalti@ankara.edu.tr; Akyüzlü, Dilek Kaya; Söylemezoğlu, Tülin

2015-02-15

Divalent metal transporter 1 (DMT1), a member of the proton-coupled metal ion transporter family, mediates transport of ferrous iron from the lumen of the intestine into the enterocyte and export of iron from endocytic vesicles. It has an affinity not only for iron but also for other divalent cations including manganese, cobalt, nickel, cadmium, lead, copper, and zinc. DMT1 is encoded by the SLC11a2 gene that is located on chromosome 12q13 in humans and express four major mammalian isoforms (1A/+IRE, 1A/-IRE, 2/+IRE and 2/-IRE). Mutations or polymorphisms of DMT1 gene may have an impact on human health by disturbing metal trafficking. To study the possible association of DMT1 gene with the blood levels of some divalent cations such as iron, lead and cadmium, a single nucleotide polymorphism (SNP) (IVS4+44C/A) in DMT1 gene was investigated in 486 unrelated and healthy individuals in a Turkish population by method of polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP). The genotype frequencies were found as 49.8% homozygote typical (CC), 38.3% heterozygote (CA) and 11.9% homozygote atypical (AA). Metal levels were analyzed by dual atomic absorption spectrometer system and the average levels of iron, lead and cadmium in the blood samples were 446.01±81.87 ppm, 35.59±17.72 ppb and 1.25±0.87 ppb, respectively. Individuals with the CC genotype had higher blood iron, lead and cadmium levels than those with AA and CA genotypes. Highly statistically significant associations were detected between IVS4+44 C/A polymorphism in the DMT1 gene and iron and lead levels (p=0.001 and p=0.036, respectively), but no association was found with cadmium level (p=0.344). This study suggested that DMT1 IVS4+44 C/A polymorphism is associated with inter-individual variations in blood iron, lead and cadmium levels. - Highlights: • DMT1 IVS4+44 C/A polymorphism is associated with inter-individual variations in blood iron, cadmium and lead levels. �

Evaluation of the effect of divalent metal transporter 1 gene polymorphism on blood iron, lead and cadmium levels

International Nuclear Information System (INIS)

Kayaaltı, Zeliha; Akyüzlü, Dilek Kaya; Söylemezoğlu, Tülin

2015-01-01

Divalent metal transporter 1 (DMT1), a member of the proton-coupled metal ion transporter family, mediates transport of ferrous iron from the lumen of the intestine into the enterocyte and export of iron from endocytic vesicles. It has an affinity not only for iron but also for other divalent cations including manganese, cobalt, nickel, cadmium, lead, copper, and zinc. DMT1 is encoded by the SLC11a2 gene that is located on chromosome 12q13 in humans and express four major mammalian isoforms (1A/+IRE, 1A/-IRE, 2/+IRE and 2/-IRE). Mutations or polymorphisms of DMT1 gene may have an impact on human health by disturbing metal trafficking. To study the possible association of DMT1 gene with the blood levels of some divalent cations such as iron, lead and cadmium, a single nucleotide polymorphism (SNP) (IVS4+44C/A) in DMT1 gene was investigated in 486 unrelated and healthy individuals in a Turkish population by method of polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP). The genotype frequencies were found as 49.8% homozygote typical (CC), 38.3% heterozygote (CA) and 11.9% homozygote atypical (AA). Metal levels were analyzed by dual atomic absorption spectrometer system and the average levels of iron, lead and cadmium in the blood samples were 446.01±81.87 ppm, 35.59±17.72 ppb and 1.25±0.87 ppb, respectively. Individuals with the CC genotype had higher blood iron, lead and cadmium levels than those with AA and CA genotypes. Highly statistically significant associations were detected between IVS4+44 C/A polymorphism in the DMT1 gene and iron and lead levels (p=0.001 and p=0.036, respectively), but no association was found with cadmium level (p=0.344). This study suggested that DMT1 IVS4+44 C/A polymorphism is associated with inter-individual variations in blood iron, lead and cadmium levels. - Highlights: • DMT1 IVS4+44 C/A polymorphism is associated with inter-individual variations in blood iron, cadmium and lead levels. �

Non-Native Metal Ion Reveals the Role of Electrostatics in Synaptotagmin 1-Membrane Interactions.

Science.gov (United States)

Katti, Sachin; Nyenhuis, Sarah B; Her, Bin; Srivastava, Atul K; Taylor, Alexander B; Hart, P John; Cafiso, David S; Igumenova, Tatyana I

2017-06-27

C2 domains are independently folded modules that often target their host proteins to anionic membranes in a Ca 2+ -dependent manner. In these cases, membrane association is triggered by Ca 2+ binding to the negatively charged loop region of the C2 domain. Here, we used a non-native metal ion, Cd 2+ , in lieu of Ca 2+ to gain insight into the contributions made by long-range Coulombic interactions and direct metal ion-lipid bridging to membrane binding. Using X-ray crystallography, NMR, Förster resonance energy transfer, and vesicle cosedimentation assays, we demonstrate that, although Cd 2+ binds to the loop region of C2A/B domains of synaptotagmin 1 with high affinity, long-range Coulombic interactions are too weak to support membrane binding of individual domains. We attribute this behavior to two factors: the stoichiometry of Cd 2+ binding to the loop regions of the C2A and C2B domains and the impaired ability of Cd 2+ to directly coordinate the lipids. In contrast, electron paramagnetic resonance experiments revealed that Cd 2+ does support membrane binding of the C2 domains in full-length synaptotagmin 1, where the high local lipid concentrations that result from membrane tethering can partially compensate for lack of a full complement of divalent metal ions and specific lipid coordination in Cd 2+ -complexed C2A/B domains. Our data suggest that long-range Coulombic interactions alone can drive the initial association of C2A/B with anionic membranes and that Ca 2+ further augments membrane binding by the formation of metal ion-lipid coordination bonds and additional Ca 2+ ion binding to the C2 domain loop regions.

Multiheteromacrocycles that Complex Metal Ions. Second Progress Report, 1 May 1975 -- 30 April 1976

Science.gov (United States)

Cram, D. J.

1976-01-15

Objective is to develop cyclic and polycyclic host organic compounds to complex and lipophilize metal ions. Macrorings were synthesized: (OCH{sub 2} CH{sub 2} O CH{sub 2}COCH{sub 2} COCH{sub 2}){sub 2} and (OCH{sub 2} CH{sub 2} O CH{sub 2} COCH{sub 2} COCH{sub 2}){sub 3}. The smaller ring complexes divalent metals 10{sup 1+9} times better than the open-chain model CH{sub 3} O CH{sub 2} CO CH{sub 2} COCH{sub 2} O CH{sub 3}, and the order in which metal ions are complexed is Cu{sup 2+}, UO{sub 2}{sup 2+} greater than Ni{sup 2+} greater than Fe{sup 2+}, Co{sup 2+}, Zn{sup 2+}, Cd{sup 2+} greater than Mn{sup 2+}. The UO{sub 2}{sup 2+} and Cu{sup 2+} complexes were isolated and characterized. The larger ring complexes trivalent metals 10{sup 0.9-1.7} times better than the open- chain model compound, and the order is La{sup 3+}, Ce{sup 3+} greater than Cr{sup 3+}. Five other macrocycles were also synthesized, and their binding constants with Na, K, NH{sub 4}, and Cs picrates were measured. Six compounds containing one macroring and two inward-pointing ArOH or ArOCH{sub 3} groups were also prepared and tested for binding of Li, Na, K, Rb, and NH{sub 4} picrates. Racemic compounds containing two binaphthyls and its sulfur analog were prepared. Cage-shaped multiheteromacrocycles containing ten O ligand sites or four S and six O ligand sites were prepared and the binding capability of the first compound for picrates studied. Two ring systems with phosphonate ester groups were also prepared. (DLC)

Ligand intermediates in metal-catalyzed reactions; Annual technical report, August 1, 1992--August 1, 1993

Energy Technology Data Exchange (ETDEWEB)

Gladysz, J.A.

1993-08-10

Achievements are reported for the following 4 areas: {pi}/{sigma} equillibria in aldehyde and ketone complexes; thermodynamic ligand binding affinities ({alpha},{beta} unsaturated organic carbonyl compounds); (a new form of coordinated carbon) an unsupported C{sub 3} chain that spans two different transition metals; and (a new form of coordinated carbon) an C{sub 3} chain that is anchored by a metal on each end and spanned by a third.

Metal-phthalocyanine ordered layers on Au(110): Metal-dependent adsorption energy

Energy Technology Data Exchange (ETDEWEB)

Massimi, Lorenzo, E-mail: lorenzo.massimi@uniroma1.it; Angelucci, Marco; Gargiani, Pierluigi; Betti, Maria Grazia [Dipartimento di Fisica, Università di Roma La “Sapienza,” 00185 Roma (Italy); Montoro, Silvia [IFIS Litoral, CONICET-UNL, Laboratorio de Fisica de Superficies e Interfaces, Güemes 3450, Santa Fe (Argentina); Mariani, Carlo, E-mail: carlo.mariani@uniroma1.it [Dipartimento di Fisica, CNISM, Università di Roma La “Sapienza,” 00185 Roma (Italy)

2014-06-28

Iron-phthalocyanine and cobalt-phthalocyanine chains, assembled along the Au(110)-(1×2) reconstructed channels, present a strong interaction with the Au metallic states, via the central metal ion. X-ray photoemission spectroscopy from the metal-2p core-levels and valence band high-resolution ultraviolet photoelectron spectroscopy bring to light signatures of the interaction of the metal-phthalocyanine single-layer with gold. The charge transfer from Au to the molecule causes the emerging of a metal-2p core level component at lower binding energy with respect to that measured in the molecular thin films, while the core-levels associated to the organic macrocycle (C and N 1s) are less influenced by the adsorption, and the macrocycles stabilize the interaction, inducing a strong interface dipole. Temperature Programmed Desorption experiments and photoemission as a function of temperature allow to estimate the adsorption energy for the thin-films, mainly due to the molecule-molecule van der Waals interaction, while the FePc and CoPc single-layers remain adsorbed on the Au surface up to at least 820 K.

APPARATUS FOR MELTING AND POURING METAL

Science.gov (United States)

Harris, F.A.

1958-02-25

This patent relates to a crucible for melting and pouring a metal under controlled atmospheric conditions. The crucible has a frangible plug in the bottom and a retaining device to prevent the entrance of the broken portions of the plug into the mold without interfering with the flow of the melt. After the charge has been melted, a knockout rod is lowered through the charge and forced against the frangible plug sufficiently to break off the closure disk along a previously scored line. The disk drops onto a retaining grid large enough to permit the flow of metal around the disk and into the mold below. Thts arrangement elimnates the entry of broken portions of the plug into the mold, thereby elimnating a common cause of imperfect castings.

Structural characterisation of 1- and 2-dimensional transition metal polymers using powder neutron diffraction

International Nuclear Information System (INIS)

James, M.

1999-01-01

Powder neutron diffraction provides an alternate technique for the structural study of transition metal polymers and finds utility over standard X-ray methods in two significant ways. Firstly, due to a different instrument geometry, preferred orientation effects are removed from the system. The second advantage gained by utilising neutrons is that H atoms in the sample contribute much more to the nuclear scattering of the diffraction profile - allowing their atomic position to be accurately determined. In X-ray diffraction studies, where H atoms typically account for only ∼3-5% of the scattering from the sample, it is essentially impossible to refine their position in the molecular structure. The structures of several transition metal polymers have been determined using neutrons from the HIFAR reactor at ANSTO and the Powder Diffractometers HRPD and MRPD, along with Rietveld refinement methods. The 1-dimensional polymer dibromobis(thiazole)nickel(II) illustrated in the paper is characteristic of these types of systems which are comprised of transition metal centres bridged by halogen atoms with pendant amine side groups

Manganese Abundances in the Stars with Metallicities -1 <[Fe/H]< +0.3

Science.gov (United States)

Mishenina, T.; Gorbaneva, T.; Pignatari, M.; Thielemann, F.-K.; Korotin, S.

2018-01-01

We estimate the Mn abundances in the atmospheres of 247 F-G-K-type dwarf stars belonging to the thin and thick disk populations in the metallicity range -1 LTE approximation; the synthetic spectrum for the Mn lines was computed accounting for the hyperfine structure. Starting from the results obtained, we discuss the evolution of the [Mn/Fe] ratio with respect to [Fe/H] in the galactic disk.

Barrier Coatings for Refractory Metals and Superalloys

Energy Technology Data Exchange (ETDEWEB)

SM Sabol; BT Randall; JD Edington; CJ Larkin; BJ Close

2006-02-23

In the closed working fluid loop of the proposed Prometheus space nuclear power plant (SNPP), there is the potential for reaction of core and plant structural materials with gas phase impurities and gas phase transport of interstitial elements between superalloy and refractory metal alloy components during service. Primary concerns are surface oxidation, interstitial embrittlement of refractory metals and decarburization of superalloys. In parallel with kinetic investigations, this letter evaluates the ability of potential coatings to prevent or impede communication between reactor and plant components. Key coating requirements are identified and current technology coating materials are reviewed relative to these requirements. Candidate coatings are identified for future evaluation based on current knowledge of design parameters and anticipated environment. Coatings were identified for superalloys and refractory metals to provide diffusion barriers to interstitial transport and act as reactive barriers to potential oxidation. Due to their high stability at low oxygen potential, alumina formers are most promising for oxidation protection given the anticipated coolant gas chemistry. A sublayer of iridium is recommended to provide inherent diffusion resistance to interstitials. Based on specific base metal selection, a thin film substrate--coating interdiffusion barrier layer may be necessary to meet mission life.

Barrier Coatings for Refractory Metals and Superalloys

International Nuclear Information System (INIS)

SM Sabol; BT Randall; JD Edington; CJ Larkin; BJ Close

2006-01-01

In the closed working fluid loop of the proposed Prometheus space nuclear power plant (SNPP), there is the potential for reaction of core and plant structural materials with gas phase impurities and gas phase transport of interstitial elements between superalloy and refractory metal alloy components during service. Primary concerns are surface oxidation, interstitial embrittlement of refractory metals and decarburization of superalloys. In parallel with kinetic investigations, this letter evaluates the ability of potential coatings to prevent or impede communication between reactor and plant components. Key coating requirements are identified and current technology coating materials are reviewed relative to these requirements. Candidate coatings are identified for future evaluation based on current knowledge of design parameters and anticipated environment. Coatings were identified for superalloys and refractory metals to provide diffusion barriers to interstitial transport and act as reactive barriers to potential oxidation. Due to their high stability at low oxygen potential, alumina formers are most promising for oxidation protection given the anticipated coolant gas chemistry. A sublayer of iridium is recommended to provide inherent diffusion resistance to interstitials. Based on specific base metal selection, a thin film substrate--coating interdiffusion barrier layer may be necessary to meet mission life

SOCS-1 deficiency does not prevent diet-induced insulin resistance

DEFF Research Database (Denmark)

Emanuelli, Brice; Macotela, Yazmin; Boucher, Jérémie

2008-01-01

Obesity is associated with inflammation and increased expression of suppressor of cytokine signaling (SOCS) proteins, which inhibit cytokine and insulin signaling. Thus, reducing SOCS expression could prevent the development of obesity-induced insulin resistance. Using SOCS-1 knockout mice, we...... investigated the contribution of SOCS-1 in the development of insulin resistance induced by a high-fat diet (HFD). SOCS-1 knockout mice on HFD gained 70% more weight, displayed a 2.3-fold increase in epididymal fat pads mass and increased hepatic lipid content. This was accompanied by increased mRNA expression...... of leptin and the macrophage marker CD68 in white adipose tissue and of SREBP1c and FAS in liver. HFD also induced hyperglycemia in SOCS-1 deficient mice with impairment of glucose and insulin tolerance tests. Thus, despite the role of SOCS proteins in obesity-related insulin resistance, SOCS-1 deficiency...

Method for preparation of melts of alkali metal chlorides with highly volatile polyvalent metal chlorides

International Nuclear Information System (INIS)

Salyulev, A.B.; Kudyakov, V.Ya.

1990-01-01

A method for production of alkali metal (Cs, Rb, K) chloride melts with highly volatile polyvalent metal chlorides is suggested. The method consists, in saturation of alkali metal chlorides, preheated to the melting point, by volatile component vapours (titanium tetrachloride, molybdenum or tantalum pentachloride) in proportion, corresponding to the composition reguired. The saturation is realized in an evacuated vessel with two heating areas for 1-1.5 h. After gradual levelling of temperature in both areas the product is rapidly cooled. 1 fig.; 1 tab

A proposal for prevention of acute radiation hazard and social panic regarding orphan sources in Japan

Energy Technology Data Exchange (ETDEWEB)

Takahash, T. [Research Reactor Institute, Kyoto Univ., Osaka (Japan); Kai, M. [Oita Univ., of Nursing and Health Sciences, Oita (Japan); Yamazaki, K. [Chiyoda Technol Corporation, Tokyo (Japan); Gomi, K. [Japan Radioisotope Association, Tokyo (Japan); Nakazato, K. [School of Medicine, Keio univ., Tokyo (Japan); Iida, T. [Nagoya Univ., Nagoya (Japan)

2002-07-01

To respond to an increase of social problems concerning orphan sources in Japan, a working group was formed in the Japan Health Physics Society. In this working group, we investigated how to prevent acute radiation hazard or social panic regarding orphan sources in scrap metal and detection system for orphan sources brought into scrap yards before recycle. For detection system in a scrap yard we conducted an experiment on detectability of monitoring instrument using a radiation source mixed in scrap metal on a truck. The result showed that it was not easy to detect even a high-level source if it was shielded by scrap metal. We also estimated detection limits for radioactive materials in scrap metal by calculation that was validated with experimental data. We summarized present status about orphan sources in Japan and proposed a categorization of orphan sources according to dose rates to deal with unknown sources in a scrap yard. Our report includes some proposals to the government, industry and academic world for preventing acute radiation hazard and social panic.

A proposal for prevention of acute radiation hazard and social panic regarding orphan sources in Japan

International Nuclear Information System (INIS)

Takahash, T.; Kai, M.; Yamazaki, K.; Gomi, K.; Nakazato, K.; Iida, T.

2002-01-01

To respond to an increase of social problems concerning orphan sources in Japan, a working group was formed in the Japan Health Physics Society. In this working group, we investigated how to prevent acute radiation hazard or social panic regarding orphan sources in scrap metal and detection system for orphan sources brought into scrap yards before recycle. For detection system in a scrap yard we conducted an experiment on detectability of monitoring instrument using a radiation source mixed in scrap metal on a truck. The result showed that it was not easy to detect even a high-level source if it was shielded by scrap metal. We also estimated detection limits for radioactive materials in scrap metal by calculation that was validated with experimental data. We summarized present status about orphan sources in Japan and proposed a categorization of orphan sources according to dose rates to deal with unknown sources in a scrap yard. Our report includes some proposals to the government, industry and academic world for preventing acute radiation hazard and social panic

The lectin from Musa paradisiaca binds with the capsid protein of tobacco mosaic virus and prevents viral infection.

Science.gov (United States)

Liu, Xiao-Yu; Li, Huan; Zhang, Wei

2014-05-04

It has been demonstrated that the lectin from Musa paradisiaca (BanLec-1) could inhibit the cellular entry of human immunodeficiency virus (HIV). In order to evaluate its effects on tobacco mosaic virus (TMV), the banlec-1 gene was cloned and transformed into Escherichia coli and tobacco, respectively. Recombinant BanLec-1 showed metal ions dependence, and higher thermal and pH stability. Overexpression of banlec-1 in tobacco resulted in decreased leaf size, and higher resistance to TMV infection, which includes reduced TMV cellular entry, more stable chlorophyll contents, and enhanced antioxidant enzymes. BanLec-1 was found to bind directly to the TMV capsid protein in vitro , and to inhibit TMV infection in a dose-dependent manner. In contrast to limited prevention in vivo , purified rBanLec-1 exhibited more significant effects on TMV infection in vitro . Taken together, our study indicated that BanLec-1 could prevent TMV infection in tobacco, probably through the interaction between BanLec-1 and TMV capsid protein.

Characteristics of Women Enrolled into a Randomized Clinical Trial of Dapivirine Vaginal Ring for HIV-1 Prevention.

Science.gov (United States)

Palanee-Phillips, Thesla; Schwartz, Katie; Brown, Elizabeth R; Govender, Vaneshree; Mgodi, Nyaradzo; Kiweewa, Flavia Matovu; Nair, Gonasagrie; Mhlanga, Felix; Siva, Samantha; Bekker, Linda-Gail; Jeenarain, Nitesha; Gaffoor, Zakir; Martinson, Francis; Makanani, Bonus; Naidoo, Sarita; Pather, Arendevi; Phillip, Jessica; Husnik, Marla J; van der Straten, Ariane; Soto-Torres, Lydia; Baeten, Jared

2015-01-01

Women in sub-Saharan Africa are a priority population for evaluation of new biomedical HIV-1 prevention strategies. Antiretroviral pre-exposure prophylaxis is a promising prevention approach; however, clinical trials among young women using daily or coitally-dependent products have found low adherence. Antiretroviral-containing vaginal microbicide rings, which release medication over a month or longer, may reduce these adherence challenges. ASPIRE (A Study to Prevent Infection with a Ring for Extended Use) is a phase III, randomized, double-blind, placebo-controlled trial testing the safety and effectiveness of a vaginal ring containing the non-nucleoside reverse transcriptase inhibitor dapivirine for prevention of HIV-1 infection. We describe the baseline characteristics of African women enrolled in the ASPIRE trial. Between August 2012 and June 2014, 5516 women were screened and 2629 HIV-1 seronegative women between 18-45 years of age were enrolled from 15 research sites in Malawi, South Africa, Uganda, and Zimbabwe. The median age was 26 years (IQR 22-31) and the majority (59%) were unmarried. Nearly 100% of participants reported having a primary sex partner in the prior three months but 43% did not know the HIV-1 status of their primary partner; 17% reported additional concurrent partners. Nearly two-thirds (64%) reported having disclosed to primary partners about planned vaginal ring use in the trial. Sexually transmitted infections were prevalent: 12% had Chlamydia trachomatis, 7% Trichomonas vaginalis, 4% Neisseria gonorrhoeae, and 1% syphilis. African HIV-1 seronegative women at risk of HIV -1 infection were successfully enrolled into a phase III trial of dapivirine vaginal ring for HIV-1 prevention.

Characteristics of Women Enrolled into a Randomized Clinical Trial of Dapivirine Vaginal Ring for HIV-1 Prevention.

Directory of Open Access Journals (Sweden)

Thesla Palanee-Phillips

Full Text Available Women in sub-Saharan Africa are a priority population for evaluation of new biomedical HIV-1 prevention strategies. Antiretroviral pre-exposure prophylaxis is a promising prevention approach; however, clinical trials among young women using daily or coitally-dependent products have found low adherence. Antiretroviral-containing vaginal microbicide rings, which release medication over a month or longer, may reduce these adherence challenges.ASPIRE (A Study to Prevent Infection with a Ring for Extended Use is a phase III, randomized, double-blind, placebo-controlled trial testing the safety and effectiveness of a vaginal ring containing the non-nucleoside reverse transcriptase inhibitor dapivirine for prevention of HIV-1 infection. We describe the baseline characteristics of African women enrolled in the ASPIRE trial.Between August 2012 and June 2014, 5516 women were screened and 2629 HIV-1 seronegative women between 18-45 years of age were enrolled from 15 research sites in Malawi, South Africa, Uganda, and Zimbabwe. The median age was 26 years (IQR 22-31 and the majority (59% were unmarried. Nearly 100% of participants reported having a primary sex partner in the prior three months but 43% did not know the HIV-1 status of their primary partner; 17% reported additional concurrent partners. Nearly two-thirds (64% reported having disclosed to primary partners about planned vaginal ring use in the trial. Sexually transmitted infections were prevalent: 12% had Chlamydia trachomatis, 7% Trichomonas vaginalis, 4% Neisseria gonorrhoeae, and 1% syphilis.African HIV-1 seronegative women at risk of HIV -1 infection were successfully enrolled into a phase III trial of dapivirine vaginal ring for HIV-1 prevention.

Characteristics of Women Enrolled into a Randomized Clinical Trial of Dapivirine Vaginal Ring for HIV-1 Prevention

Science.gov (United States)

Palanee-Phillips, Thesla; Schwartz, Katie; Brown, Elizabeth R.; Govender, Vaneshree; Mgodi, Nyaradzo; Kiweewa, Flavia Matovu; Nair, Gonasagrie; Mhlanga, Felix; Siva, Samantha; Bekker, Linda-Gail; Jeenarain, Nitesha; Gaffoor, Zakir; Martinson, Francis; Makanani, Bonus; Naidoo, Sarita; Pather, Arendevi; Phillip, Jessica; Husnik, Marla J.; van der Straten, Ariane; Soto-Torres, Lydia; Baeten, Jared

2015-01-01

Introduction Women in sub-Saharan Africa are a priority population for evaluation of new biomedical HIV-1 prevention strategies. Antiretroviral pre-exposure prophylaxis is a promising prevention approach; however, clinical trials among young women using daily or coitally-dependent products have found low adherence. Antiretroviral-containing vaginal microbicide rings, which release medication over a month or longer, may reduce these adherence challenges. Methods ASPIRE (A Study to Prevent Infection with a Ring for Extended Use) is a phase III, randomized, double-blind, placebo-controlled trial testing the safety and effectiveness of a vaginal ring containing the non-nucleoside reverse transcriptase inhibitor dapivirine for prevention of HIV-1 infection. We describe the baseline characteristics of African women enrolled in the ASPIRE trial. Results Between August 2012 and June 2014, 5516 women were screened and 2629 HIV-1 seronegative women between 18–45 years of age were enrolled from 15 research sites in Malawi, South Africa, Uganda, and Zimbabwe. The median age was 26 years (IQR 22–31) and the majority (59%) were unmarried. Nearly 100% of participants reported having a primary sex partner in the prior three months but 43% did not know the HIV-1 status of their primary partner; 17% reported additional concurrent partners. Nearly two-thirds (64%) reported having disclosed to primary partners about planned vaginal ring use in the trial. Sexually transmitted infections were prevalent: 12% had Chlamydia trachomatis, 7% Trichomonas vaginalis, 4% Neisseria gonorrhoeae, and 1% syphilis. Conclusions African HIV-1 seronegative women at risk of HIV -1 infection were successfully enrolled into a phase III trial of dapivirine vaginal ring for HIV-1 prevention. PMID:26061040

Shock Hazard Prevention through Self-Healing Insulative Coating on SSA Metallic Bearings, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The space suit assembly (SSA) contains metallic bearings at the wrist, neck, and waist, which are exposed to space environment, and pose a potential shock hazard....

Cytology of pollutant metals in marine invertebrates: A review of microanalytical applications

International Nuclear Information System (INIS)

Nott, J.A.

1991-01-01

x-ray microanalysis (XRMA) is customized for investigations of the metabolic and detoxification strategies of heavy metals taken by marine organisms from polluted environments. Sites of uptake, intracellular accumulation, transport and excretion are visualized, analysed and quantified. Cryopreparation techniques are required to prevent the translocation or loss from specimens of soluble metal species. In marine invertebrates, metals are detoxified by systems of chemical binding and intracellular compartmentalization. XRMA investigations have concentrated on marine molluscs and crustaceans and even within these restricted groups there are marked inter-species differences in the biochemical and cytological processes which reduce metal bioavailability. Some detoxification systems also protect the carnivores which ingest the metal-laden tissues of the prey. This results in the bioreduction of metals along a food chain. These processes are investigated by XRMA which can be tuned to observe the complex interactions which operate at all levels within and between the biota and polluted environments. 90 refs

Metals for bone implants. Part 1. Powder metallurgy and implant rendering.

Science.gov (United States)

Andani, Mohsen Taheri; Shayesteh Moghaddam, Narges; Haberland, Christoph; Dean, David; Miller, Michael J; Elahinia, Mohammad

2014-10-01

New metal alloys and metal fabrication strategies are likely to benefit future skeletal implant strategies. These metals and fabrication strategies were looked at from the point of view of standard-of-care implants for the mandible. These implants are used as part of the treatment for segmental resection due to oropharyngeal cancer, injury or correction of deformity due to pathology or congenital defect. The focus of this two-part review is the issues associated with the failure of existing mandibular implants that are due to mismatched material properties. Potential directions for future research are also studied. To mitigate these issues, the use of low-stiffness metallic alloys has been highlighted. To this end, the development, processing and biocompatibility of superelastic NiTi as well as resorbable magnesium-based alloys are discussed. Additionally, engineered porosity is reviewed as it can be an effective way of matching the stiffness of an implant with the surrounding tissue. These porosities and the overall geometry of the implant can be optimized for strain transduction and with a tailored stiffness profile. Rendering patient-specific, site-specific, morphology-specific and function-specific implants can now be achieved using these and other metals with bone-like material properties by additive manufacturing. The biocompatibility of implants prepared from superelastic and resorbable alloys is also reviewed. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Heavy metal-induced cytotoxicity to cultured human epidermal keratinocytes and effects of antioxidants.

Science.gov (United States)

Kappus, H; Reinhold, C

1994-04-01

Human epidermal keratinocytes which have been cultured were treated with the heavy metal ions of cadmium, mercury, copper and zinc. Cytotoxicity was measured either by protein estimation or by using the neutral red assay. Antioxidants were added in order to find out whether heavy metal-induced cytotoxicity is related to oxidative stress. All metals used showed considerable cytotoxic effects within 24 h in moderate concentrations. None of the antioxidants vitamin E (alpha-tocopherol), pyrogallol, propyl gallate, BHT or ebselen showed any protective or preventive effect. This indicates that oxidative stress may not be involved in the cytotoxicity induced by heavy metals in human epidermal keratinocytes. The cells used are, however, a valuable tool to study mechanisms of cytotoxicity.

Preventing thefts and wilful damage

CERN Multimedia

DG Unit

2011-01-01

The best means of preventing crime is to make it difficult to commit. As the summer holidays begin, in everybody’s interest we advise the following precautions: 1. MONEY, VALUABLES & KEYS Never leave money or objects of value unattended in offices or changing rooms, even locked. Keys and spares must always be taken away or kept in a safe place. Supposedly “safe” hiding places such as drawers, even locked, metal boxes and flower pots, are well known to burglars and should be avoided. Change lock codes regularly. 2. DOORS & WINDOWS Offices, workshops and meeting-rooms, etc. should be locked when vacated. Care should also be taken that windows are properly shut, especially if they are easily accessible from the outside. 3. VANDALISM If you witness an act of vandalism of public or private property, please report all the facts and your observations immediately to the CERN Fire Brigade (74444). 4. REPORTING INCIDENTS Every misdemeanour solved increases the chances of others be...

The ICAM-1 antisense oligonucleotide ISIS-3082 prevents the development of postoperative ileus in mice

NARCIS (Netherlands)

The, Frans O.; de Jonge, Wouter J.; Bennink, Roel J.; van den Wijngaard, Rene M.; Boeckxstaens, Guy E.

2005-01-01

1 Intestinal manipulation (IM) during abdominal surgery triggers the influx of inflammatory cells, leading to postoperative ileus. Prevention of this local muscle inflammation, using intercellular adhesion molecule-1 ( ICAM-1) and leukocyte function-associated antigen-1-specific antibodies, has been

Coordination Polymers and Metal Organic Frameworks Derived from 1,2,4-Triazole Amino Acid Linkers

Directory of Open Access Journals (Sweden)

Yann Garcia

2011-10-01

Full Text Available The perceptible appearance of biomolecules as prospective building blocks in the architecture of coordination polymers (CPs and metal-organic frameworks (MOFs are redolent of their inclusion in the synthon/tecton library of reticular chemistry. In this frame, for the first time a synthetic strategy has been established for amine derivatization in amino acids into 1,2,4-triazoles. A set of novel 1,2,4-triazole derivatized amino acids were introduced as superlative precursors in the design of 1D coordination polymers, 2D chiral helicates and 3D metal-organic frameworks. Applications associated with these compounds are diverse and include gas adsorption-porosity partitioning, soft sacrificial matrix for morphology and phase selective cadmium oxide synthesis, FeII spin crossover materials, zinc-b-lactamases inhibitors, logistics for generation of chiral/non-centrosymmetric networks; and thus led to a foundation of a new family of functional CPs and MOFs that are reviewed in this invited contribution.

A stochastic empirical model for heavy-metal balnces in Agro-ecosystems

NARCIS (Netherlands)

Keller, A.N.; Steiger, von B.; Zee, van der S.E.A.T.M.; Schulin, R.

2001-01-01

Mass flux balancing provides essential information for preventive strategies against heavy-metal accumulation in agricultural soils that may result from atmospheric deposition and application of fertilizers and pesticides. In this paper we present the empirical stochastic balance model, PROTERRA-S,

Feet sunk in molten aluminium: The burn and its prevention.

Science.gov (United States)

Alonso-Peña, David; Arnáiz-García, María Elena; Valero-Gasalla, Javier Luis; Arnáiz-García, Ana María; Campillo-Campaña, Ramón; Alonso-Peña, Javier; González-Santos, Jose María; Fernández-Díaz, Alaska Leonor; Arnáiz, Javier

2015-08-01

Nowadays, despite improvements in safety rules and inspections in the metal industry, foundry workers are not free from burn accidents. Injuries caused by molten metals include burns secondary to molten iron, aluminium, zinc, copper, brass, bronze, manganese, lead and steel. Molten aluminium is one of the most common causative agents of burns (60%); however, only a few publications exist concerning injuries from molten aluminium. The main mechanisms of lesion from molten aluminium include direct contact of the molten metal with the skin or through safety apparel, or when the metal splash burns through the pants and rolls downward along the leg. Herein, we report three cases of deep dermal burns after 'soaking' the foot in liquid aluminium and its evolutive features. This paper aims to show our experience in the management of burns due to molten aluminium. We describe the current management principles and the key features of injury prevention. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

Method of producing homogeneous mixed metal oxides and metal-metal oxide mixtures

International Nuclear Information System (INIS)

Quinby, T.C.

1980-01-01

A method for preparing particulate metal or metal oxide of controlled partile size comprises contacting an an aqueous solution containing dissolved metal values with excess urea at a temperature sufficient to cause urea to react with water to provide a molten urea solution containing the metal values; heating the molten urea solution to cause the metal values to precipitate, forming a mixture containing precipitated metal values; heating the mixture containing precipitated metal values to evaporate volatile material leaving a dry powder containing said metal values. The dry powder can be calcined to provide particulate metal oxide or reduced to provide particulate metal. Oxide mixtures are provided when the aqueous solution contains values of more than one metal. Homogeneousmetal-metal oxide mistures for preparing cermets can be prepared by selectively reducing at least one of the metal oxides. (auth)

Zirconium sponge and other forms of virgin metal for nuclear applications - approved standard 1973

International Nuclear Information System (INIS)

Anon.

1975-01-01

This specification covers virgin zirconium metal commonly designated as sponge because of its porous, sponge-like texture, but it may also take other forms such as chunklets. One grade is described which is designated as reactor grade R-1, suitable for use in nuclear applications. The most important characteristic of the reactor grade is its low nuclear cross section as achieved by removal of hafnium and careful quality control in manufacturing procedures to prevent contamination with other high cross section materials

Simultaneous Formation of Artificial SEI Film and 3D Host for Stable Metallic Sodium Anodes.

Science.gov (United States)

Zhang, Di; Li, Bin; Wang, Shuai; Yang, Shubin

2017-11-22

Metallic sodium is a promising anode for sodium-based batteries, owing to its high theoretical capacity (1165 mAh g -1 ) and low potential (-2.714 V vs standard hydrogen electrode). However, the growth of sodium dendrites and the infinite volume change of metallic sodium during sodium striping/plating result in a low Coulombic efficiency and poor cycling stability, generating a safety hazard of sodium-based batteries. Here, an efficient approach was proposed to simultaneously generate an artificial SEI film and 3D host for metallic sodium based on a conversion reaction (CR) between sodium and MoS 2 (4Na + MoS 2 = 2Na 2 S + Mo) at room temperature. In the resultant sodium-MoS 2 hybrid after the conversion reaction (Na-MoS 2 (CR)), the production Na 2 S is homogeneously dispersed on the surface of metallic sodium, which can act as an artificial SEI film, efficiently preventing the growth of sodium dendrites; the residual MoS 2 nanosheets can construct a 3D host to confine metallic sodium, accommodating largely the volume change of sodium. Consequently, the Na-MoS 2 (CR) hybrid exhibits very low overpotential of 25 mV and a very long cycle stability more than 1000 cycles. This novel strategy is promising to promote the development of metal (lithium, sodium, zinc)-based electrodes.

Metal complexes with 1,5- and 1,8-dihydroxy-9,10-anthraquinones: electronic absorption spectra and structure of ligands

International Nuclear Information System (INIS)

Fajn, V.Ya.; Zajtsev, B.E.; Ryabov, M.A.

2004-01-01

By spectrophotometric, quantum-chemical, and correlation methods it is determined that in complexes of metals (Nd, Pr, Sm, Th, UO 2 2+ , V) with 1,5-dihydroxy-9,10-anthraquinone ligand could be in 7 excited states differing not only by ionization degree but primary contribution of tautomeric 9,10-, 1,10-, and 1,5-anthraquinoid structures. On all known complexes with 1,8-dihydroxy-9,10-anthraquinone containing once ionized ligand the last has 1,10-anthraquinoid structure; for complexes containing twofold ionized ligand 9,10-anthraquinoid structure of ligand is the most characteristic. Known complexes are classified in accordance with structure of ligands [ru

Optical amplifier operating at 1.3 microns useful for telecommunications and based on dysprosium-doped metal chloride host materials

Energy Technology Data Exchange (ETDEWEB)

Page, R.H.; Schaffers, K.I.; Payne, S.A.; Krupke, W.F.; Beach, R.J.

1997-12-02

Dysprosium-doped metal chloride materials offer laser properties advantageous for use as optical amplifiers in the 1.3 {micro}m telecommunications fiber optic network. The upper laser level is characterized by a millisecond lifetime, the host material possesses a moderately low refractive index, and the gain peak occurs near 1.31 {micro}m. Related halide materials, including bromides and iodides, are also useful. The Dy{sup 3+}-doped metal chlorides can be pumped with laser diodes and yield 1.3 {micro}m signal gain levels significantly beyond those currently available. 9 figs.

Optical amplifier operating at 1.3 microns useful for telecommunications and based on dysprosium-doped metal chloride host materials

Energy Technology Data Exchange (ETDEWEB)

Page, Ralph H. (San Ramon, CA); Schaffers, Kathleen I. (Pleasanton, CA); Payne, Stephen A. (Castro Valley, CA); Krupke, William F. (Pleasanton, CA); Beach, Raymond J. (Livermore, CA)

1997-01-01

Dysprosium-doped metal chloride materials offer laser properties advantageous for use as optical amplifiers in the 1.3 .mu.m telecommunications fiber optic network. The upper laser level is characterized by a millisecond lifetime, the host material possesses a moderately low refractive index, and the gain peak occurs near 1.31 .mu.m. Related halide materials, including bromides and iodides, are also useful. The Dy.sup.3+ -doped metal chlorides can be pumped with laser diodes and yield 1.3 .mu.m signal gain levels significantly beyond those currently available.

RIKEN 200 kV high current implanter for metal surface modification

International Nuclear Information System (INIS)

Iwaki, M.; Yoshida, K.; Sakudo, N.

1985-01-01

A high current, metal ion implanter was constructed in order to aid the formation of a new metastable surface alloy. This implanter, called a RIKEN 200 kV high current implanter, is a modified Lintott high current machine (Series III), which has the advantages of having its own microwave ion source and an extra target chamber. The microwave discharge ion source without a hot-filament has a comparatively long lifetime because the chloride ions and radicals in a plasma during discharge of metal chlorides might prevent metal to deposit on the inner walls of the discharge chamber by bombarding and chemically cleaning them. An extra target chamber for metal modification is able to control the surface composition by utilizing the sputtering effect of the ion beam during ion implantation. The use of this ion source and the extra target chamber is suggested to be suitable for the production of metallic ions and for the implantation into metals. The case study will be introduced for TI implantation into Fe. (orig.)

Method of producing homogeneous mixed metal oxides and metal--metal oxide mixtures

International Nuclear Information System (INIS)

Quinby, T.C.

1978-01-01

Metal powders, metal oxide powders, and mixtures thereof of controlled particle size are provided by reacting an aqueous solution containing dissolved metal values with excess urea. Upon heating, urea reacts with water from the solution to leave a molten urea solution containing the metal values. The molten urea solution is heated to above about 180 0 C, whereupon metal values precipitate homogeneously as a powder. The powder is reduced to metal or calcined to form oxide particles. One or more metal oxides in a mixture can be selectively reduced to produce metal particles or a mixture of metal and metal oxide particles

Metal-ion catalyzed polymerization in the eutectic phase in water-ice

DEFF Research Database (Denmark)

Monnard, Pierre-Alain; Szostak, Jack W.

2008-01-01

The emergence of an RNA world requires among other processes the non-enzymatic, template-directed replication of genetic polymers such as RNA or related nucleic acids, possibly catalyzed by metal ions. The absence of uridilate derivative polymerization on adenine containing templates has been...... the main issue preventing an efficient template-directed RNA polymerization. We report here the investigation of template-directed RNA polymerization in the eutectic phase in water-ice. In particular, it was found that activated Uridilate monomers in the presence of metal-ion catalysts could efficiently......-pairing opportunities. These results suggest that a template-directed RNA polymerization catalyzed by metal-ions could be carried out under eutectic phase in water-ice conditions....

Stability of metallic foams studied under microgravity

CERN Document Server

Wuebben, T; Banhart, J; Odenbach, S

2003-01-01

Metal foams are prepared by mixing a metal powder and a gas-releasing blowing agent, by densifying the mix to a dense precursor and finally foaming by melting the powder compact. The foaming process of aluminium foams is monitored in situ by x-ray radioscopy. One observes that foam evolution is accompanied by film rupture processes which lead to foam coalescence. In order to elucidate the importance of oxides for foam stability, lead foams were manufactured from lead powders having two different oxide contents. The two foam types were generated on Earth and under weightlessness during parabolic flights. The measurements show that the main function of oxide particles is to prevent coalescence, while their influence on bulk viscosity of the melt is of secondary importance.

Air quality in the Kootenays: fine particulate (PM{sub 1}0) airborne metals and sulphur dioxide levels, 1993-1999

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-09-01

Air quality monitoring data collected in the Kootenays over a seven year period from 1993 to 1999 are summarized in an effort to inform the public about air quality in the Kootenays and to assist them in understanding air quality monitoring results. Data includes hourly (TEOM) and weekly (NAPS) data for particulate matter (PM{sub 1}0) airborne metals (arsenic, cadmium, lead and zinc) and sulphur dioxide. Analysis of monitoring data showed that particulate matter levels remained constant in most communities, with Johnson Lake and Slocan reporting the lowest levels, while Golden had the highest values during this period. Trail-Butler Park showed a clear declining trend in PM{sub 1}0. Airborne metals and sulphur dioxide levels have decreased in the Kootenays during the seven year period, with only occasional exceedances of both Level A and B air quality objectives in some communities. The report includes a detailed description of the sampling methodology and the analyzed results for PM{sub 1}0, airborne metals and sulphur dioxide for 10 communities in the region. 6 refs., 1 tab., 16 figs., 1 map.

Application of siliceous metal product for preliminary deoxidizing of metal in open-hearth furnaces

International Nuclear Information System (INIS)

Luk'yanenko, A.A.; Evdokimov, A.V.; Kornilov, V.N.; Il'in, V.I.; Kuleshov, Yu.V.

1995-01-01

Metal wastes of abrasive processes-concomitant product of synthetic corundum production containing approximately 10 % Si - were tested for preliminary deoxidizing of metal in furnace to reduce manganese loss in burning and to increase the steel deoxidizing. The technology of preliminary deoxidizing of metal by siliceous metal product was mastered in the course of low carbon steel melting (st3sp, st4sp). The results of the study has shown that the use of siliceous metal product permits reducing the consumption of manganese-containing ferroalloys. 1 tab

Shock Hazard Prevention through Self-Healing Insulative Coating on SSA Metallic Bearings, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The space suit contains metallic bearings at the wrist, neck, and waist, which are exposed to the space environment. There is a need to maintain a high degree of...

The interaction of bacteria and metal surfaces

International Nuclear Information System (INIS)

Mansfeld, Florian

2007-01-01

This review discusses different examples for the interaction of bacteria and metal surfaces based on work reported previously by various authors and work performed by the author with colleagues at other institutions and with his graduate students at CEEL. Traditionally it has been assumed that the interaction of bacteria with metal surfaces always causes increased corrosion rates ('microbiologically influenced corrosion' (MIC)). However, more recently it has been observed that many bacteria can reduce corrosion rates of different metals and alloys in many corrosive environments. For example, it has been found that certain strains of Shewanella can prevent pitting of Al 2024 in artificial seawater, tarnishing of brass and rusting of mild steel. It has been observed that corrosion started again when the biofilm was killed by adding antibiotics. The mechanism of corrosion protection seems to be different for different bacteria since it has been found that the corrosion potential E corr became more negative in the presence of Shewanella ana and algae, but more positive in the presence of Bacillus subtilis. These findings have been used in an initial study of the bacterial battery in which Shewanella oneidensis MR-1 was added to a cell containing Al 2024 and Cu in a growth medium. It was found that the power output of this cell continuously increased with time. In the microbial fuel cell (MFC) bacteria oxidize the fuel and transfer electrons directly to the anode. In initial studies EIS has been used to characterize the anode, cathode and membrane properties for different operating conditions of a MFC that contained Shewanella oneidensis MR-1. Cell voltage (V)-current density (i) curves were obtained using potentiodynamic sweeps. The current output of a MFC has been monitored for different experimental conditions

The interaction of bacteria and metal surfaces

Energy Technology Data Exchange (ETDEWEB)

Mansfeld, Florian [Corrosion and Environmental Effects Laboratory (CEEL), The Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089-0241 (United States)

2007-10-10

This review discusses different examples for the interaction of bacteria and metal surfaces based on work reported previously by various authors and work performed by the author with colleagues at other institutions and with his graduate students at CEEL. Traditionally it has been assumed that the interaction of bacteria with metal surfaces always causes increased corrosion rates ('microbiologically influenced corrosion' (MIC)). However, more recently it has been observed that many bacteria can reduce corrosion rates of different metals and alloys in many corrosive environments. For example, it has been found that certain strains of Shewanella can prevent pitting of Al 2024 in artificial seawater, tarnishing of brass and rusting of mild steel. It has been observed that corrosion started again when the biofilm was killed by adding antibiotics. The mechanism of corrosion protection seems to be different for different bacteria since it has been found that the corrosion potential E{sub corr} became more negative in the presence of Shewanella ana and algae, but more positive in the presence of Bacillus subtilis. These findings have been used in an initial study of the bacterial battery in which Shewanella oneidensis MR-1 was added to a cell containing Al 2024 and Cu in a growth medium. It was found that the power output of this cell continuously increased with time. In the microbial fuel cell (MFC) bacteria oxidize the fuel and transfer electrons directly to the anode. In initial studies EIS has been used to characterize the anode, cathode and membrane properties for different operating conditions of a MFC that contained Shewanella oneidensis MR-1. Cell voltage (V) - current density (i) curves were obtained using potentiodynamic sweeps. The current output of a MFC has been monitored for different experimental conditions. (author)

Mechanism of selective ion flotation. 1. Selective flotation of transition metal cations

International Nuclear Information System (INIS)

Walkowiak, W.

1991-01-01

An experimental investigation is presented of the batch ion flotation of the transition metal cations Cr 3+ , Fe 3+ , Mn 2+ , Co 2+ , Zn 2+ , Ag + , Cd 2+ , and In 3+ from acidic aqueous solutions with sodium dodecylsulfonate and sodium dodecylbenzenesulfonate as anionic surfactants. The selectivity sequences Mn 2+ 2+ 2+ 3+ 3+ and Ag + 2+ 3+ are established, both from data for single and multi-ion metal cations solutions, where sublate was not formed in the bulk solution. Good agreement between the selectivity sequences and the values of ionic potential of metal cations was found. An experimental investigation was also performed on the solubility of sublates. The sublates solubility values are discussed in terms of ionic potentials of metal cations as well as of the surfactant size

Education for AIDS Prevention: Bibliography--Supplement No. 1=Education pour la prevention du SIDA: Bibliographie--Supplement No. 1=Educacion para la Prevencion del SIDA: Bibliografia--Suplemento No. 1.

Science.gov (United States)

United Nations Educational, Scientific, and Cultural Organization, Paris (France). Documentation and Information Service.

This supplement to the Education for AIDS Prevention Bibliography provides a list of titles received by ASERC (AIDS School Education Resource Centre) from August 1991 to December 1992, consisting mainly of educational material for schools. It also includes documents of a more general nature on AIDS and AIDS prevention. ASERC is a documentation…

Heavy metals in wild house mice from coal-mining areas of Colombia and expression of genes related to oxidative stress, DNA damage and exposure to metals.

Science.gov (United States)

Guerrero-Castilla, Angélica; Olivero-Verbel, Jesús; Marrugo-Negrete, José

2014-03-01

Coal mining is a source of pollutants that impact on environmental and human health. This study examined the metal content and the transcriptional status of gene markers associated with oxidative stress, metal transport and DNA damage in livers of feral mice collected near coal-mining operations, in comparison with mice obtained from a reference site. Mus musculus specimens were caught from La Loma and La Jagua, two coal-mining sites in the north of Colombia, as well as from Valledupar (Cesar Department), a city located 100km north of the mines. Concentrations in liver tissue of Hg, Zn, Pb, Cd, Cu and As were determined by differential stripping voltammetry, and real-time PCR was used to measure gene expression. Compared with the reference group (Valledupar), hepatic concentrations of Cd, Cu and Zn were significantly higher in animals living near mining areas. In exposed animals, the mRNA expression of NQ01, MT1, SOD1, MT2, and DDIT3 was 4.2-, 7.3-, 2.5-, 4.6- and 3.4-fold greater in coal mining sites, respectively, than in animals from the reference site (pmining may generate pollutants that could affect the biota, inducing the transcription of biochemical markers related to oxidative stress, metal exposure, and DNA damage. These changes may be in part linked to metal toxicity, and could have implications for the development of chronic disease. Therefore, it is essential to implement preventive measures to minimize the effects of coal mining on its nearby environment, in order to protect human health. Copyright © 2014 Elsevier B.V. All rights reserved.

Aromatic plant production on metal contaminated soils

International Nuclear Information System (INIS)

Zheljazkov, Valtcho D.; Craker, Lyle E.; Xing Baoshan; Nielsen, Niels E.; Wilcox, Andrew

2008-01-01

Field and container experiments were conducted to assess the feasibility of growing aromatic crops in metal contaminated areas and the effect of metals on herbage and oil productivity. The field experiments were conducted in the vicinities of the Non-Ferrous Metals Combine (Zn-Cu smelter) near Plovdiv, Bulgaria using coriander, sage, dill, basil, hyssop, lemon balm, and chamomile grown at various distances from the smelter. Herbage essential oil yields of basil, chamomile, dill, and sage were reduced when they were grown closer to the smelter. Metal removal from the site with the harvestable plant parts was as high as 180 g ha -1 for Cd, 660 g ha -1 for Pb, 180 g ha -1 for Cu, 350 g ha -1 for Mn, and 205 g ha -1 for Zn. Sequential extraction of soil demonstrated that metal fractionation was affected by the distance to the smelter. With decreasing distance to the smelter, the transfer factor (TF) for Cu and Zn decreased but increased for Cd, while the bioavailability factor (BF) for Cd, Pb, Cu, Mn, and Zn decreased. Scanning electron microscopy and X-ray microanalyses of contaminated soil verified that most of the Pb, Cd, Mn, Cu, and Zn were in the form of small (< 1 μm) particles, although there were larger particles (1-5 μm) with high concentrations of individual metals. This study demonstrated that high concentrations of heavy metals in soil or growth medium did not result in metal transfer into the essential oil. Of the tested metals, only Cu at high concentrations may reduce oil content. Our results demonstrated that aromatic crops may not have significant phytoremediation potential, but growth of these crops in metal contaminated agricultural soils is a feasible alternative. Aromatic crops can provide economic return and metal-free final product, the essential oil

Aromatic plant production on metal contaminated soils

Energy Technology Data Exchange (ETDEWEB)

Zheljazkov, Valtcho D. [Mississippi State, Department of Plant and Soil Sciences and North Mississippi Research and Extension Center, 5421 Highway 145 South, Verona, MS 38879 (United States)], E-mail: vj40@pss.msstate.edu; Craker, Lyle E.; Xing Baoshan [Department of Plant and Soil Sciences, 12 Stockbridge Hall, University of Massachusetts, Amherst, MA 01003 (United States); Nielsen, Niels E. [Plant Nutrition and Soil Fertility Lab, Department of Agricultural Sciences, Royal Veterinary and Agricultural University, Thorvaldsensvej 40, DK1871, Copenhagen (Denmark); Wilcox, Andrew [Harper Adams University College, Newport, Shropshire, TF10 8NB (United Kingdom)

2008-06-01

Field and container experiments were conducted to assess the feasibility of growing aromatic crops in metal contaminated areas and the effect of metals on herbage and oil productivity. The field experiments were conducted in the vicinities of the Non-Ferrous Metals Combine (Zn-Cu smelter) near Plovdiv, Bulgaria using coriander, sage, dill, basil, hyssop, lemon balm, and chamomile grown at various distances from the smelter. Herbage essential oil yields of basil, chamomile, dill, and sage were reduced when they were grown closer to the smelter. Metal removal from the site with the harvestable plant parts was as high as 180 g ha{sup -1} for Cd, 660 g ha{sup -1} for Pb, 180 g ha{sup -1} for Cu, 350 g ha{sup -1} for Mn, and 205 g ha{sup -1} for Zn. Sequential extraction of soil demonstrated that metal fractionation was affected by the distance to the smelter. With decreasing distance to the smelter, the transfer factor (TF) for Cu and Zn decreased but increased for Cd, while the bioavailability factor (BF) for Cd, Pb, Cu, Mn, and Zn decreased. Scanning electron microscopy and X-ray microanalyses of contaminated soil verified that most of the Pb, Cd, Mn, Cu, and Zn were in the form of small (< 1 {mu}m) particles, although there were larger particles (1-5 {mu}m) with high concentrations of individual metals. This study demonstrated that high concentrations of heavy metals in soil or growth medium did not result in metal transfer into the essential oil. Of the tested metals, only Cu at high concentrations may reduce oil content. Our results demonstrated that aromatic crops may not have significant phytoremediation potential, but growth of these crops in metal contaminated agricultural soils is a feasible alternative. Aromatic crops can provide economic return and metal-free final product, the essential oil.

Do constructed wetlands remove metals or increase metal bioavailability?

Science.gov (United States)

Xu, Xiaoyu; Mills, Gary L

2018-07-15

The H-02 wetland was constructed to treat building process water and storm runoff water from the Tritium Processing Facility on the Department of Energy's Savannah River Site (Aiken, SC). Monthly monitoring of copper (Cu) and zinc (Zn) concentrations and water quality parameters in surface waters continued from 2014 to 2016. Metal speciation was modeled at each sampling occasion. Total Cu and Zn concentrations released to the effluent stream were below the NPDES limit, and the average removal efficiency was 65.9% for Cu and 71.1% for Zn. The metal-removal processes were found out to be seasonally regulated by sulfur cycling indicated by laboratory and model results. High temperature, adequate labile organic matter, and anaerobic conditions during the warm months (February to August) favored sulfate reduction that produced sulfide minerals to significantly remove metals. However, the dominant reaction in sulfur cycling shifted to sulfide oxidation during the cool months (September to next March). High concentrations of metal-organic complexes were observed, especially colloidal complexes of metal and fulvic acid (FA), demonstrating adsorption to organic matter became the primary process for metal removal. Meanwhile, the accumulation of metal-FA complexes in the wetland system will cause negative effects to the surrounding environment as they are biologically reactive, highly bioavailable, and can be easily taken up and transferred to ecosystems by trophic exchange. Copyright © 2018 Elsevier Ltd. All rights reserved.

Synthesis, characterization, antimicrobial and anthelmentic activities of some metal complexes with a new Schiff base 3-[(Z)-5-amino-1,3,3-trimethyl cyclohexylmethylimino]-1,3-dihydroindol-2-one

International Nuclear Information System (INIS)

Reddy, K. R. K; Mahendra, K.N.

2008-01-01

The complexes of Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), dioxouranium(VI), and Th(IV) with a new Schiff base, 3-[(Z)-5-amino-1,3,3-trimethyl cyclohexylmethylimino]-1,3-dihydroindol-2-one formed by the condensation of isatin (Indole-2.3-dione) with isophoronediamine(5-amino-1,3,3-trimethyl-cyclohexane methylamine) were synthesized and characterized by microanalysis, conductivity, UV-visible, FT-IR, 1 H NMR, TGA, and magnetic susceptibility measurements. All the complexes exhibit 1: 1 metal to ligand ratio except for the dioxouranium(VI) and thorium(IV) complexes, where the metal: ligand stoichiometry is 1: 2. The spectral data revealed that the ligand acts as monobasic bidentate, coordinating to the metal ion through the azomethine nitrogen and carbonyl oxygen of the isatin moiety. Tetrahedral geometry for Co(II), Ni(II), Zn(II), Cd(II), and Hg(II) complexes, square planar geometry for Cu(II) complexes, and the coordination numbers 6 and 8 for UO 2 (VI) and Th(IV) complexes, respectively, are proposed. Both the ligand and the metal complexes were screened for their antibacterial activity against Bacillus subtilis, Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Pseudomonas aeruginosa, and the complexes are more potent bactericides than the ligand. The anthelmintic activity of the ligand and its complexes against earthworms was also investigated [ru

Control of Orphan Sources and Other Radioactive Material in the Metal Recycling and Production Industries. Specific Safety Guide (Spanish Edition); Control de fuentes huérfanas y otros materiales radiactivos en las industrias de reciclado y producción de metales. Guía de seguridad específica

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-12-15

Accidents involving orphan sources and other radioactive material in the metal recycling and production industries have resulted in serious radiological accidents as well as in harmful environmental, social and economic impacts. This Safety Guide provides recommendations, the implementation of which should prevent such accidents and provide confidence that scrap metal and recycled products are safe. Contents: 1. Introduction; 2. Protection of people and the environment; 3. Responsibilities; 4. Monitoring for radioactive material; 5. Response to the discovery of radioactive material; 6. Remediation of contaminated areas; 7. Management of recovered radioactive material; Annex I: Review of events involving radioactive material in the metal recycling and production industries; Annex II: Categorization of radioactive sources; Annex III: Some examples of national and international initiatives.

Gas metal arc weldability of 1.5 GPa grade martensitic steels

Science.gov (United States)

Hwang, Insung; Yun, Hyeonsang; Kim, Dongcheol; Kang, Munjin; Kim, Young-Min

2018-01-01

The gas metal arc weldability of 1.5 GPa grade martensitic (MART) steel was evaluated using both inverter direct current (DC) and DC pulse power type welders, under conditions of different welding currents, welding speeds, and shielding gasses. By investigating the bead appearance, tensile strength, and arc stability, it was determined that DC pulse power is better than inverter DC power for arc welding of 1.3 mm thick 1.5 GPa grade MART steel. Further, from the results of the weldability for various shielding gases, it was determined that mixed shielding gas is more effective for welding 1.5 GPa grade MART steel than is pure inert gas (Ar) or active (CO2) gas. In the case of pure shielding gas, no sound bead was formed under any conditions. However, when the mixed shielding gas was used, sound and fine beads were obtained.

Peruvian perovskite Between Transition-metal to PGM/PlatinumGroupMetal Catalytic Fusion

Science.gov (United States)

Maksoed, Wh-

2016-11-01

Strongly correlated electronic materials made of simple building blocks, such as a transition-metal ion in an octahedral oxygen cage forming a perovskite structure- Dagotto & Tokura for examples are the high-temperature superconductivity & the CMR/Colossal Magnetoresistance . Helium-4 denotes from LC Case,ScD: "Catalytic Fusion of Deuterium into Helium-4"- 1998 dealt with gaseous D2- "contacted with a supported metallic catalyst at superatmospheric pressure". The catalyst is a platinum-group metal, at about 0.5% - 1% by weight, on activated C. Accompanies Stephen J Geier, 2010 quotes "transition metal complexes", the Energy thus produced is enormous, and because the deuterium is very cheap in the form of heavy water (less than US 1/g), the fuel cost is very low (seas &Deuteronomy to be eternally preserves. Heartfelt Gratitudes to HE. Mr. Prof. Ir. HANDOJO.

Structure and properties of transition metal-metalloid glasses based on refractory metals

International Nuclear Information System (INIS)

Johnson, W.L.; Williams, A.R.

1979-01-01

The structure and properties of several new transition metal-metalloid (TM/sub 1-x/M/sub x/) metallic glasses based on refractory transition metals (e.g. Mo, W, Ru etc.) have been systemically investigated as a function of composition. The structure of the alloys has been investigated by x-ray diffraction methods and measurements of superconducting properties, electrical resistivity, density, hardness, and mechanical behavior were made. These data are used in developing a novel description of the structure of TM/sub 1-x/M/sub x/ glasses. The experimental evidence suggests that an ideal amorphous phase forms at a specific composition x/sub c/ and that this phase has a well defined atomic short range order. For metallic glasses having x x/sub c/. This novel picture can explain the variation of many properties of these glasses with metalloid concentration

HIV Prevention

Centers for Disease Control (CDC) Podcasts

2012-02-01

Dr. Kevin Fenton, Director of CDC’s National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, talks about steps people can take to protect their health from HIV.  Created: 2/1/2012 by National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP).   Date Released: 2/1/2012.

Potential of RNA aptamers in the prevention of HIV-1 subtype C infections

CSIR Research Space (South Africa)

London, GM

2014-10-01

Full Text Available Compounds that have been used to prevent human immunodeficiency virus type-I (HIV-1) infections include synthetic chemicals, plant extras and monoclonal antibodies. Although most of these compounds have potent antiviral activity, they often fail...

In Alzheimer's disease, 6-month treatment with GLP-1 analog prevents decline of brain glucose metabolism

DEFF Research Database (Denmark)

Gejl, Michael; Gjedde, Albert; Egefjord, Lærke

2016-01-01

In animal models, the incretin hormone GLP-1 affects Alzheimer's disease (AD). We hypothesized that treatment with GLP-1 or an analog of GLP-1 would prevent accumulation of Aβ and raise, or prevent decline of, glucose metabolism (CMRglc) in AD. In this 26-week trial, we randomized 38 patients...... with AD to treatment with the GLP-1 analog liraglutide (n = 18), or placebo (n = 20). We measured Aβ load in brain with tracer [11C]PIB (PIB), CMRglc with [18F]FDG (FDG), and cognition with the WMS-IV scale (ClinicalTrials.gov NCT01469351). The PIB binding increased significantly in temporal lobe...

Metal assessment in urban park soils in Sao Paulo. 3. Aclimacao Park

International Nuclear Information System (INIS)

Pavese, Arthur C.; Figueiredo, Ana Maria G.; Camargo, Sonia P.; Gumiero, Felipe C.; Enzweiler, Jacinta

2007-01-01

As part of a project which aims metal assessment in urban park soils from Sao Paulo, in the present paper the concentration of the elements As, Ba, Zn, Sb, Se, Co, Cr, Cu and Pb were determined in surface soil samples (0-5 cm and 0-20 cm) from Aclimacao park of Sao Paulo. Urban soils play an important role in maintaining the environmental quality as they can act as both source and sink for pollutants that can affect human health. Parks and playgrounds are where urban children spend most of their time outdoors and are also where children most frequently come in contact with soil. Aclimacao park is located at the central region of the city, in a residential area. Instrumental Neutron Activation Analysis (INAA) and X-Ray Fluorescence (XRF) were used for metal analysis. The results obtained for Zn were higher than the values considered as reference values for soils in Sao Paulo, according to the Environmental Protection Agency of the State of Sao Paulo (CETESB), but lower than the Prevention values. For Ba, Cr, and Sb, the results obtained showed concentration levels higher than Prevention value reported by CETESB. According to CETESB, metal concentration levels above the Prevention value can cause prejudicial alterations in soil and subterranean water quality. For As, in the 0-5 cm samples, the concentration levels were near or above the Intervention value for agricultural area reported by CETESB. (author)

Evaluation of Heavy Metal Contamination Ecological Risk in a Food-Producing Ecosystem

Directory of Open Access Journals (Sweden)

mohsen Mirzaei

2017-09-01

Full Text Available Introduction and purpose: The consumption of agricultural products cultivated in soils contaminated with heavy metals is very health-threatening. Therefore, the implementation of an inclusive and multilateral assessment of the heavy metal risk on the verge of their entrance to the food chain is a matter of fundamental importance. Regarding this, the present study was conducted with the aim of monitoring the concentration of heavy metals in the surface soil of grape gardens and zoning the area in terms of geoaccumulation index (Igeo, contamination factor, degree of contamination, modified degree of contamination (MDC, pollution load index (PLI, and ecological risk index (RI. Methods: For the purpose of the study, 31 grape gardens were selected in Gahru region (i.e., the main center of grape production through simple random sampling technique. The surface soil samples were transferred to the laboratory for the analysis of the concentration of cadmium, lead, chromium, copper, and zinc. Results: According to the results, the concentration of the metals in the region was Zn > Cu > Pb > Cr > Cd with the mean total concentrations of 74.87, 55.31, 22.32, 9.81, and 0.91 mg/kg, respectively. Based on the results of the PLI, six grape gardens were classified as insignificantly contaminated (1≤PLI≤2, and the remaining gardens were classified as noncontaminated (PLI300, medium (150metals and critical stations. Meanwhile, cadmium and copper caused the highest concern in some of the grape gardens of the investigated region. Therefore, it is suggested to prevent the entrance of larger amounts of cadmium in the area by training and raising the awareness of the gardeners about the amount of phosphate fertilizers and fungicide and encouraging them to use animal manures and take preventive

Alkali metal and alkali earth metal gadolinium halide scintillators

Science.gov (United States)

Bourret-Courchesne, Edith; Derenzo, Stephen E.; Parms, Shameka; Porter-Chapman, Yetta D.; Wiggins, Latoria K.

2016-08-02

The present invention provides for a composition comprising an inorganic scintillator comprising a gadolinium halide, optionally cerium-doped, having the formula A.sub.nGdX.sub.m:Ce; wherein A is nothing, an alkali metal, such as Li or Na, or an alkali earth metal, such as Ba; X is F, Br, Cl, or I; n is an integer from 1 to 2; m is an integer from 4 to 7; and the molar percent of cerium is 0% to 100%. The gadolinium halides or alkali earth metal gadolinium halides are scintillators and produce a bright luminescence upon irradiation by a suitable radiation.

Safety design analyses of Korea Advanced Liquid Metal Reactor

International Nuclear Information System (INIS)

Suk, S.D.; Park, C.K.

2000-01-01

The national long-term R and D program updated in 1997 requires Korea Atomic Energy Research Institute (KAERI) to complete by the year 2006 the basic design of Korea Advanced Liquid Metal Reactor (KALIMER), along with supporting R and D work, with the capability of resolving the issue of spent fuel storage as well as with significantly enhanced safety. KALIMER is a 150 MWe pool-type sodium cooled prototype reactor that uses metallic fuel. The conceptual design is currently under way to establish a self consistent design meeting a set of the major safety design requirements for accident prevention. Some of current emphasis include those for inherent and passive means of negative reactivity insertion and decay heat removal, high shutdown reliability, prevention of and protection from sodium chemical reaction, and high seismic margin, among others. All of these requirements affect the reactor design significantly and involve supporting R and D programs of substance. This paper summarizes some of the results of engineering and design analyses performed for the safety of KALIMER. (author)

The radiological monitoring protocol for metallic products and cleared scrap management

International Nuclear Information System (INIS)

Gil Lopez, E.

2003-01-01

Event though the use of nuclear and radiological techniques is subject to strict controls in most countries, the presence of radioactive material in batches of metallic scrap has been detected with relative frequency in the last few years. This circumstance has motivated the implementation of a series of national and international initiatives aimed at detecting and preventing this type of events, whether they be intentional or involuntary. The Spanish iron and steel industry is one of the country's most important industrial sectors, and to a great extent it depends on the importation of a very significant amount of metallic scrap that it uses as raw material. Experience has shown that countries that import large amounts of scrap, apart from supporting the mentioned international initiatives, should complement them with other national initiatives to reduce the risks resulting from the presence of radioactive material in scrap. In this context, the Spanish authorities, together with trade unions and entrepreneurial associations in the metal reclamations and smelting sectors and ENRESA, have signed a voluntary Protocol that defines and implements a national radiological monitoring and control system for scrap materials and their byproducts. The Protocol defines the obligations and rights of the signatories, and it describes the monitoring and control system and its legal bases, the operation of both specific and other general-purpose radiological monitoring equipment that existed prior to this initiative, the development of radiological training and dissemination plans for professionals in the metal reclamation and smelting sectors, the establishment of effective systems for the safe management of any radioactive materials detected, and the general improvement of the national response system in the event of radiological emergencies. Since the Protocol took effect in November 1999, more than 100 enterprises from the metallurgical (steel, copper, lead and aluminum