WorldWideScience
1

Determination of some minor and trace elements in iron ores by ion exchange chromatography, spectrophotometry and atomic absorption spectrometry  

International Nuclear Information System (INIS)

A method is described for determination of aluminium, cadmium, cobalt, chromium, copper, calcium, magnesium, sodium, potassium, manganese, nickel, lead, strontium, zinc, titanium and vanadium in iron ore. After dissolution, a 1 gram sample of iron ore is applied to a column of AGI-X8 anion exchange resin (chloride form), in 100 ml of 7M HCl. Aluminium, chromium, calcium, magnesium, sodium, potassium, manganese, nickel, lead, strontium, titanium and vanadium are eluted with 7M HCl; iron, copper and cobalt are eluted with 0.5M HCl; cadmium and zinc are eluted with 2M HNO_3. Iron is subsequently removed from copper and cobalt by a solvent extraction with methyl isobutyl ketone. The elements are determined in the eluates by atomic absorption spectrometry, except for titanium and vanadium, which are determined ...

2

The separation and determination of trace elements in iron ore  

International Nuclear Information System (INIS)

The separation, concentration, and determination of trace elements in iron ores are described. After the sample has been dissolved, the iron is separated by liquid-liquid extraction with a liquid cation-exchanger, di-(2-ethylhexyl) phosphoric acid. The trace elements aluminium, cadmium, calcium, chromium, cobalt, copper, lead, magnesium, manganese, mercury, potassium, sodium, vanadium, and zinc are determined in the aqueous phase by atomic-absorption spectrophotometry.

2008-05-01

3

Phase diagrams  

International Nuclear Information System (INIS)

The description is presented of binary phase diagrams of titanium alloyed with the following elements: silver, aluminium, arsenic, gold, boron, barium, beryllium, bismuth, carbon, calcium, cadmium, cobalt, chromium, copper, iron, gallium, germanium, hydrogen, hafnium, indium, iridium, potassium, lithium, magnesium, manganese, molybdenum, nitrogen, sodium, niobium, nickel, oxygen, osmium, phosphorus, lead, palladium, platinum, plutonium, rhenium, lanthanium, cerium, preseodymium, neodymium, gadolinium, erbium, terbium, thulium, lutetium, rhodium, ruthenium, scandium, silicon, tin, strontium, tantalum, technetium, thorium, uranium, vanadium, tungsten, yttrium, ytterbium, zinc and zirconium.

4

Smoke Compositions Based on Phosphorus  

Science.gov (United States)

... Both magnesium and aluminium phosphides are therefore potentially more efficient than either calcium or sodium phosphide. ...

1958-03-01

6

Catalyst for the manufacture of acrylonitrile and methacrylonitrile  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a catalyst composition. It consists of the catalytic oxides of iron, bismuth, molybdenum and magnesium as essential components and optionally the oxides of cobalt, nickel, phosphorus and arsenic.

1989-09-05

7

Trace metal characterization of the U-Al matrix by atomic spectroscopy  

International Nuclear Information System (INIS)

Uranium-aluminum alloys with a significant enrichment of uranium with "2"3"3U or "2"3"5U serve as nuclear fuels in research reactors. The quality assurance of this fuel requires, among other things, precise knowledge that all trace metal constituents that affect neutron economy, fuel integrity, and fuel fabrication process parameters are well within the specification limits. Trace metal characterization of "2"3"5U-Al alloy has been carried out by atomic spectrometry. The trace metal constituents of interest are grouped into common metals (silver, boron, calcium, cadmium, cobalt, chromium, copper, iron, magnesium, manganese, molybdenum, sodium, nickel, lead, silicon, tin, titanium, vanadium, tungsten, and zinc) and lanthanides (cerium, dysprosium, europium, gadolinium, holminium, lutetium, samarium, and terbium). The elements yttrium and zirconium are grouped with the latter in view of the chemical separation procedure used. ...

8

Dietary Ammonium Chloride for the Acidification of Mouse Urine  

UK PubMed Central (United Kingdom)

A novel therapeutic compound was found to induce bladder tumors in male rats. Given the location of the tumors and the increased amounts of calcium- and magnesium-containing solids found in the urine...Full Text Available

2009-03-01

9

New coumarin-based sensor molecule for magnesium and calcium ions  

British Library Electronic Table of Contents (United Kingdom)

A new coumarin-based sensor molecule (L1) has been synthesized and this was found to bind calcium and magnesium ions more effectively as compared to other alkali/alkaline earth/lanthanide and certain transition metal ions. A significant enhancement in fluorescence intensity was observed on binding to Ca2+ and Mg2+ ions; while a minor quenching was observed for weakly bound Hg2+, Ni2+, Fe3+, and Co2+ ions. PET process, coupled with the ICT process, is proposed to explain the observed spectral response.

2009-01-01

10

INVESTIGATION OF GLASS-METAL COMPOSITE ...  

Science.gov (United States)

... having high fluidity. The SC-51A alloy contains 4.5 to 5.5% silicon, 1 to 1.5% coppers .4 to .6% magnesium, o35% sine, .8% iron, .5% manganes*, ...

1957-09-01

11

Stabilisation of #alpha#-Sialons using multiple additives  

International Nuclear Information System (INIS)

Multi-cation #alpha#-Sialon ceramics were prepared using mixtures of samarium with calcium, magnesium, yttrium and ytterbium, and compared with a pure Sm-Sialon of equivalent total stabilising cation composition. A ratio of 80eq% samarium to 20eq% of the second stabilising additive was used. Samples were fired at 1820 deg C and subsequently heat treated at 1450 deg C. XRD phase analysis showed that all additives resulted in greater #alpha#-Sialon stability, and that calcium was the most effective additive for the stabilisation of the #alpha#-Sialon phase. Copyright (1998) Australasian Ceramic Society

1998-09-28

12

Double promotion of palladium/silica catalysts by iron and magnesium oxide in the synthesis of methanol from carbon monoxide and hydrogen  

Energy Technology Data Exchange (ETDEWEB)

The structure and catalytic properties of 2 wt.-% Pd/SiO/sub 2/ catalysts promoted with 2 wt.-% MgO and 0.2-5 wt.-% iron have been investigated. Catalysts were characterized by TPR, hydrogen chemisorption, and Moessbauer spectroscopy and their catalytic performance in methanol formation was also measured. At 16 at.-% iron a sharp maximum was observed in the activity which can be interpreted as being due to simultaneous promotion with iron and MgO. Independent mechanisms of promotion were found for the two modifiers: iron influenced the metallic component by forming bimetallic PdFe particles while MgO changed the properties of silica in a favourable way. 6 figs., 29 refs., 1 tab.

1988-12-01

13

Radionuclide X-ray fluorescence analysis of waste water from the production of citric acid  

Energy Technology Data Exchange (ETDEWEB)

Radionuclide X-ray fluorescence analysis was used for the determination of iron, calcium, potassium, copper, manganese and zinc in waste water from the production process of citric acid.

1982-02-18

14

Radionuclide X-ray fluorescence analysis of waste water from the production of citric acid  

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence analysis was used for the determination of iron, calcium, potassium, copper, manganese and zinc in waste water from the production process of citric acid. (author).

1982-02-01

15

Magnesium Sensitizes Slow Vacuolar Channels to Physiological Cytosolic Calcium and Inhibits Fast Vacuolar Channels in Fava Bean Guard Cell Vacuoles1  

UK PubMed Central (United Kingdom)

Vacuolar ion channels in guard cells play important roles during stomatal movement and are regulated by many factors including Ca2+, calmodulin, protein kinases, and phosphatases....Full Text Available

1999-11-01

16

Dietary calcium and magnesium intakes and the risk of type 2 diabetes: the Shanghai Women's Health Study123  

UK PubMed Central (United Kingdom)

Background: Diet plays a key role in the development of type 2 diabetes (T2D), but little is known about the contributions of specific nutrients in populations in which dietary patterns...Full Text Available

2009-04-01

17

A comparison of nutrient dynamics in forest ecosystems along with the Warmth Index Gradient  

Energy Technology Data Exchange (ETDEWEB)

Nutrient elements contained in litter fall flux, that of uptake flux and turnover rate had generally tended to increase with the increase in the Warmth Index, while the amount of nutrient in the A[sub 0] horizon and nutrient use efficiency did not. However, it is suggested that topographic and climatic aridity, and the amount of available and exchangeable phosphorus, calcium and magnesium greatly affect the nutrient dynamics in a each forest ecosystem as the Warmth Index increases. (J.P.N.).

1993-01-01

18

A Laser-Pointer-Based Spectrometer for Endpoint Detection of EDTA Titrations  

Science.gov (United States)

A laser spectrometer for the ethylenediaminetetra-acetic acid (EDTA) titration of magnesium or calcium ions that is designed around a handheld laser pointer as the source and a photoresistor as the detector is developed. Findings show that the use of the spectrometer reduces the degree of uncertainty and error in one part of the EDTA titrations, however overall standard deviations depend on the skill of the student and their willingness to be careful and precise.

2004-12-01

19

Mineral carbonation accelerated by dicarboxylic acids as a disposal process of carbon dioxide  

British Library Electronic Table of Contents (United Kingdom)

Mineral carbonation is based on the reaction of carbon dioxide with metal-oxide bearing minerals, usually containing magnesium or calcium silicate, to form hardly soluble carbonates and other solid byproducts. The concept is based on acceleration of the naturally occurring rock weathering process. In the present work the calcium silicate is present in the mineral, wollastonite. To accelerate the process and make it potentially useful for practical applications, mineral carbonation is conducted here using an indirect two-step route in which the reactive component (Ca^2^+ ions in considered case) is first extracted from the mineral matrix and afterwards carbonated. Two solid byproducts are formed in this process: silica in the extraction step and calcium carbonate in the carbonation step. In...

2011-01-01

20

Process development for production of coal/sorbent agglomerates. Final technical report, September 1, 1990--August 31, 1991  

Energy Technology Data Exchange (ETDEWEB)

The goal of this work was to develop a process flow diagram to economically produce a clean-burning fuel from fine Illinois coal. To accomplish this, the process of pelletizing fine coal with calcium hydroxide, a sulfur capturing sorbent, was investigated. Carbonation, which is the reaction of calcium hydroxide with carbon dioxide (in the presence of moisture) to produce a bonding matrix of calcium carbonate, was investigated as a method for improving pellet quality and reducing binder costs. Proper moisture level is critical to allow the reaction to occur. If too much moisture is present in a pellet, the pore spaces are filled and carbon dioxide must diffuse through the water to reach the calcium hydroxide and react. This severely slows or stops the reaction. The ideal situation is when there is just enough moisture to coat the calcium hydroxide allowing for the reaction to ...

1991-12-31

21

Influence of microalloying on the corrosion resistance of steel in saturated calcium hydroxide  

International Nuclear Information System (INIS)

The influence of microalloying vanadium or titanium on improving the corrosion resistance of mild steel in saturated calcium hydroxide solution was investigated. Potential-time, potentiodynamic polarization, and impedance measurement techniques were employed. The corrosion products have been examined by infrared and X-ray diffraction analysis and by scanning electron microscopy. It has been shown that the grain refining, due to microalloying, plays an important role in enhancing the corrosion resistance of steel. Scales of calcite and iron oxides on top of a protective oxide are formed on the investigated steels.

22

Probable role of trace elements of some medicinal plants in cardio-vascular diseases  

International Nuclear Information System (INIS)

A number of herbal drugs are used in the Unani (Greco-Arab) System of Medicine for cardiovascular diseases. The herbs were analyzed by flame AAS and ICP-AES to determine if their therapeutic actions can be associated with the elements present in them. Cadmium, cobalt, chromium, copper, iron, potassium, magnesium, manganese, sodium, nickel, phosphorus, lead and zinc were some of the elements which play various roles in cardiovascular affections. An effort was made to correlate the role of these elements in cardiac diseases. (Auth.). 2 tabs., 32 refs.

23

Anodic oxide coatings on metals and anodic protection /2nd revised and enlarged edition/. Anodnye oksidnye pokrytiia na metallakh i anodnaia zashchita /2nd revised and enlarged edition/  

Energy Technology Data Exchange (ETDEWEB)

The theoretical principles underlying the formation of oxide and, in particular, anodic oxide coatings on metals produced by chemical oxidation, anodizing in solutions, and anodizing in cold plasmas are reviewed. The mechanisms and conditions of anodic oxidation are described, and the structure of anodic oxide coatings on aluminum, magnesium, beryllium, zinc, cadmium, iron, cobalt, nickel, titanium, zirconium, tantalum, and chromium alloys is examined. Attention is also given to various applictins of anodized coatings. 54 references.

1985-01-01

24

Drinking water composition and incidence of urinary calculus: introducing a new index.  

Science.gov (United States)

INTRODUCTION. We searched for a pathophysiologically based feature of major water electrolytes, which may define water quality better than the water hardness, respecting urinary calculus formation. MATERIALS AND METHODS. Utilizing a multistage stratified sampling, 2310 patients were diagnosed in the imaging centers of the provincial capitals in Iran between 2007 and 2008. These were composed of 1755 patients who were settled residents of 24 provincial capitals. Data on the regional drinking water composition, obtained from an accredited registry, and their relationships with the region's incidence of urinary calculi were evaluated by metaregression models. The stone risk index (defined as the ratio of calcium to magnesium-bicarbonate product in drinking water) was used to assess the risk of calculus formation. RESULTS. No correlation was found between the urinary calculus incidence and the amount of calcium, bicarbonate, or ...

2011-01-01

25

Development and performance of a miniature, high-voltage thermal battery  

Science.gov (United States)

A miniature, high-voltage, thermally activated battery has been developed. This battery weighs 41 grams, occupies a volume of 16.4 cu cm, and contains two separate 500-v channels, each designed to charge a 5.25 microfarad capacitor within 300 milli-seconds and remain operational under a 640-kohm load for a minimum of 28 seconds over the temperature range from +16 to +71 C. The electrochemical system utilizes a calcium anode, LiCl-KCl molten salt electrolyte, a CaCrO4-K2CrO4 mixture as the depolarizer or active cathode material, and an iron cathode. The depolarizer and electrolyte, along with a silica binder, are formed into homogeneous pellets, and these pellets are stacked alternately with calcium-iron bimetal disks in beryllium oxide tubes to form cell stacks. The cells are activated by an iron-potassium perchlorate pyrotechnic heat source external to the BeO tubes.

1974-01-01

26

Effect of secondary fuels and combustor temperature on mercury speciation in pulverized fuel co-combustion: part 1  

Energy Technology Data Exchange (ETDEWEB)

The present work mainly involves bench scale studies to investigate partitioning of mercury in pulverized fuel co-combustion at 1000 and 1300{sup o}C. High volatile bituminous coal is used as a reference case and chicken manure, olive residue, and B quality (demolition) wood are used as secondary fuels with 10 and 20% thermal shares. The combustion experiments are carried out in an entrained flow reactor with a fuel input of 7-8 kWth. Elemental and total gaseous mercury concentrations in the flue gas of the reactor are measured on-line, and ash is analyzed for particulate mercury along with other elemental and surface properties. Animal waste like chicken manure behaves very differently from plant waste. The higher chlorine contents of chicken manure cause higher ionic mercury concentrations whereas even with high unburnt carbon, particulate mercury reduces with increase in the chicken manure share. This might be a problem due to coarse fuel particles, low surface area, and ...

2007-08-15

27

Thermodynamics of aqueous magnesium chloride, calcium chloride, and strontium chloride at elevated temperatures  

International Nuclear Information System (INIS)

Heat capacities and densities of aqueous MgCl/sub 2/, CaCl/sub 2/, and SrCl/sub 2/ from the accompanying paper are combined with literature data up to 473 K to yield temperature-dependent equations by using the ion-interaction model of Pitzer. These heat capacity equations have been integrated to yield the enthalpy and the Gibbs energy. The enthalpy parameters for 298 K are evaluated in separate calculations using published high-temperature osmotic data as well as heats of dilution, while the Gibbs energy parameters for 298 K are taken from the literature. The range of validity of the final equations is described.

1987-01-01

28

Pilot testing of sodium thiosulfate  

Energy Technology Data Exchange (ETDEWEB)

Pilot plant tests have been conducted to evaluate sodium thiosulfate as an oxidation inhibition additive in five lime/limestone slurry flue gas desulfurization processes. It was found that the oxidation rate of absorbed sulfur dioxide (SO)/sub 2/ was reduced by more than 50 percent in the presence of 100 to 200 ppm of thiosulfate ion in the scrubbing slurry. Calcium sulfate dihydrate (gypsum) scaling was eliminated and the unsaturated (with respect to gypsum) operation mode was maintained by the addition of sodium thiosulfate. Other benefits of sodium thiosulfate addition observed at the pilot plant included improvement in solids dewatering properties for limestone processes and improvement in SO/sub 2/ removal efficiency for magnesium-enhanced lime/limestone processes.

1986-11-01

29

Pilot testing of sodium thiosulfate  

Energy Technology Data Exchange (ETDEWEB)

The article gives results of pilot-plant tests to evaluate sodium thiosulfate as an oxidation-inhibition additive in five lime/limestone slurry flue-gas desulfurization processes. It was found that the oxidation rate of absorbed SO/sub 2/ was reduced by more than 50% in the presence of 100-200 ppm of thiosulfate ion in the scrubbing slurry. Calcium sulfate dihydrate (gypsum) scaling was eliminated and the unsaturated (with respect to gypsum) operation mode was maintained by the addition of sodium thiosulfate. Other benefits of sodium thiosulfate addition observed at the pilot plant included improvement in solids dewatering properties for limestone processes and improvement in SO/sub 2/ removal efficiency for magnesium-enhanced lime/limestone processes.

1986-01-01

30

Pilot testing of sodium thiosulfate  

Energy Technology Data Exchange (ETDEWEB)

The article gives results of pilot-plant tests to evaluate sodium thiosulfate as an oxidation-inhibition additive in five lime/limestone slurry flue-gas desulfurization processes. It was found that the oxidation rate of absorbed SO/sub 2/ was reduced by more than 50% in the presence of 100-200 ppm of thiosulfate ion in the scrubbing slurry. Calcium sulfate dihydrate (gypsum) scaling was eliminated and the unsaturated (with respect to gypsum) operation mode was maintained by the addition of sodium thiosulfate. Other benefits of sodium thiosulfate addition observed at the pilot plant included improvement in solids dewatering properties for limestone processes and improvements in SO/sub 2/ removal efficiency for magnesium-enhanced lime/limestone processes.

1986-11-01

31

Nomographs for the rapid prediction of salt quality and influent water quality impacts on hardness leakage in steamflood water  

Energy Technology Data Exchange (ETDEWEB)

Counter-current regeneration of 2-stage sodium zeolite softeners has been employed in reducing hardness leakage level of steamflooding water to less than 1 ppm when raw water contains as much as 5,000 ppm of the total dissolved solids. Hardness leakage is caused by sodium displacement of calcium and magnesium from the bottom of the exchanger bed. This study presents nomographs providing for rapid calculations to be made, for which a convenient operational mode does not already exist. The nomographs relate the hardness leakage as a function of salt quality and influent water quality and present solutions for predicting the leakage level, salt quality requirement or the treatability of raw water required for steamflooding projects.

1982-08-01

32

Isotopes and groundwater management strategies under semi-arid area: Case of the Souss upstream basin (Morocco)  

International Nuclear Information System (INIS)

This study concerns the Souss upstream basin. The objective is to investigate the characteristics of surface water and groundwater, to assess the impact of artificial recharge as reinforcement of the natural replenishment and assess the renewal of groundwater under semi-arid area. Two major water types are observed: (i) surface waters and upstream springs (least mineralized) and (ii) all groundwater samples (prevailing calcium and magnesium bicarbonate water type). Water isotopes show a low evaporation of precipitations during infiltration. Impoverishment in heavy isotopes is the characteristic of mountain rainfalls, or of a climate colder and wetter than present. Carbon-14 activities (34-94 pmc) indicate a long residence time. The artificial recharge is low compared to the reservoir volume, due to which the renewal rate is also low.

2011-07-01

33

Fractionation of isotopes of alkali metals and alkaline earth metals in ion exchange chromatography  

International Nuclear Information System (INIS)

Fractionation of isotopes of the alkali metals and the alkaline earth metals in ion exchange chromatography of their chlorides was studied. The heavier isotopes of potassium and rubidium were found to be preferentially fractionated into the ion exchanger phase while the lighter isotopes of lithium, magnesium, calcium and strontium were enriched in the exchanger phase. This can be interpreted as a resultant of the relative significance of isotope effect upon dehydration and isotope effect accompanying the phase change of the hydrated metal ion. Found was no evidence of anomalous isotope effect attributable to the odd-even difference in mass number of isotopes. Based on the spectroscopic and solution chemical data (experimental and theoretical), the isotopic reduced partition function ratios of the hydrated alkaline metal ions and stretching force constants of metal ion-hydrating water bonds were estimated. (author).

34

Elimination of Separation Processes for Post-Consumer Polyolefin Waste: Reactive Blending Using 1,3-Phenylene Dimaleimide in Presence of Filler  

British Library Electronic Table of Contents (United Kingdom)

A novel approach using reactive processing is explored that eliminates the labour-intensive separation of post-consumer polyolefin waste from the mixed plastics waste stream. The reactive compatibiliser BMI has been used to form a modified blend of PCPW with 40% improved tensile strength relative to the uncompatibilised control. Addition of 60 wt.-% magnesium hydroxide [Mg(OH)2] during reactive compatibilisation with BMI gave rise to an even more significant enhancement (up to 100%) of the tensile strength. BMI was also able to usefully enhance the properties of a composite based on calcium carbonate and the polyolefin waste.

2009-01-01

35

Chromatography of metal ions with a triazine chelating resin  

International Nuclear Information System (INIS)

The synthesis, characterization, and some analytical applications of a new triazine resin are described. Separation of group IB, IIB, VIB, and VIIB metal ions from group VIII metal ions is achieved by this PDT-4 resin. Calcium(II) and magnesium(II) are taken up at pH = 6, 0.1 M acetate and are eluted at pH = 6, 0.1 M sodium nitrate. Copper(II) is retained at pH = 6, 0.1 M acetate and pH = 1 hydrochloric acid and is eluted subsequently by 5 M perchloric acid. Molybdenum(VI) is sorbed selectively from 0.1 N sulfuric acid or hydrochloric acid and is eluted in a tight band by 0.1 N sodium hydroxide. Numerous rapid column chromatographic separations are reported using this new resin, including analysis of NBS standard samples.

36

Chemical plant factors affecting resistance in sugarcane in against Scirpophaga Nivella f  

International Nuclear Information System (INIS)

The study was conducted during 2000 to determine the role of various chemical plant factors viz., total minerals, nitrogen, fat contents, carbohydrate, macro an micro nutrients in the leaves of five genotypes of sugarcane i.e., BF-162, SPSG-26, L-118, CP-43/33 and CP-72/2086 by correlating the infestation of top borer, Scirpophaga Nivella F. at tillering stage. None of the genotype was found completely resistant to the pest. CP-43/33 and BF-162 proved susceptible and resistant varieties, respectively. Total mineral, manganese and copper contents did not show significant correlation with the pest infestation, whereas nitrogen, potassium, calcium, magnesium and ferrous contents played a positive and significant role. Phosphorous, carbohydrates, fats and zinc contents played a significant and negative effect on the pest infestation at tillering stage. (author)

37

A method for preventing cathodic deposition of molybdenum subchloride in LiCl-KCl molten salt  

Energy Technology Data Exchange (ETDEWEB)

Effects of ions of Group IA, IIA, IIIB, and VIIB elements on the cathodic deposition of a molybdenum were investigated in a KCl-LiCl (eutectic)-MoCl/sub 3/ molten salt at 773 K (500/degree/C). The results can be summarized as follows: The addition of potassium, rubidium, cesium, and barium cations and fluorine anions to the KCl-LiCl (eutectic)-MoCl/sub 3/ molten salt is effective in depressing the cathodic deposition of the molybdenum subchloride, which hinders the smooth, flat electrodeposition of molybdenum. The addition of lithium, sodium, magnesium, calcium, strontium, and aluminum cations and bromine and iodine anions promotes the undesirable cathodic deposition of the molybdenum subchloride.

1989-01-01

38

Mine drainage treatment; Kogyo haisui shori  

Energy Technology Data Exchange (ETDEWEB)

The generation of acidic mine drainage is based on the oxidation dissolution of sulfide minerals due to the contact of ores with the natural water and the air. Namely, the sulfuric acid promotes the dissolution of sulfide minerals and gangue minerals, and Fe{sup 2+} is further oxidized to turn into Fe{sup 3+}, which acts as an oxidizer for other sulfide minerals and promotes the dissolution of the same. This paper roughly describes a mine drainage treatment focusing on an Fe{sup 2+} neutralization method and an iron bacteria oxidation method. The iron bacteria oxidation method is a method of oxidizing Fe{sup 2+} into Fe{sup 3+} by using iron bacteria, and then removing Fe{sup 3+} with calcium carbonate. This method has been used for treating the drainage in the Sakuhara Mine and the former Matsuo Mine, with good results. The paper finally introduces, as power-saving low-cost mine drainage treatment ...

1996-05-25

40

Difference in the effects produced by non-radioactive and radioactive calcium  

International Nuclear Information System (INIS)

... aluminum calcium calcium 45 cations citric acid corrosion inhibition radiation

41

Pilot project ''measurement of efficacy'' - biological monitoring of antimony pollution in the Munich test area using a standardized grass culture  

International Nuclear Information System (INIS)

This pilot project was carried out for the purpose of testing methods for active biological monitoring. It covered a period of three years (until September 1994), including two years of exposure. The measurements served to determine pollutant levels in plants used as animal fodder and dust-borne heavy metal concentrations in different sites and, on this basis, to obtain indirect information on human exposure. Among others, the pilot project investigated the suitability of Italian rye-grass as a biological indicator for aluminium, arsenic, cadmium, cobalt, chromium, copper, iron, mercury, magnesium, manganese, nickel, lead, platinum, antimony, titanium, and zinc. (orig./GL).

42

Biphasic calcium sulfate dihydrate/iron-modified alpha-tricalcium phosphate bone cement for spinal applications: in vitro study  

Energy Technology Data Exchange (ETDEWEB)

In this study, the cytocompatibility of new 'iron-modified/alpha-tricalcium phosphate (IM/alpha-TCP) and calcium sulfate dihydrate (CSD)' bone cement (IM/alpha-TCP/CSD-BC) intended for spinal applications has been approached. The objective was to investigate by direct-contact osteoblast-like cell cultures (from 1 to 14 days) the in vitro cell adhesion, proliferation, morphology and cytoskeleton organization of MG-63 cells seeded onto the new cements. The results were as follows: (a) quantitative MTT-assay and scanning electron microscopy (SEM) showed that cell adhesion, proliferation and viability were not affected with time by the presence of iron in the cements; (b) double immunofluorescent labeling of F-actin and alpha-tubulin showed a dynamic interaction between the cell and its porous substrates sustaining the locomotion phenomenon on the cements' surface, which favored the colonization, and ...

2010-04-15

43

Separation of magnesium from magnesium chloride and zirconium and/or hafnium subchlorides in the production of zirconium and/or hafnium sponge metal  

International Nuclear Information System (INIS)

This patent describes the producing of a refractory metal wherein a sponge refractory metal is produced as an intermediate product by the use of magnesium with the incidental production of magnesium chloride, and wherein residual magnesium is separated from the magnesium chloride and from refractory metal to a vacuum distillation step which fractionally distills the magnesium, the magnesium chloride, and the metal sub-chlorides; the steps of: recovering fractionally distilled vapors of magnesium chloride and metal sub-chlorides from a sponge refractory metal; separately condensing the vapors as separately recovered; and recycling the separately recovered magnesium at a purity of at least about 96%.

1990-09-21

46

Studies of the behaviour of technical chemicals introduced into the subsoil under modelled conditions  

International Nuclear Information System (INIS)

Because of the environmental hazard of organic solvents such as chlorinated or aromatic hydrocarbons, water soluble and biodegradable substitutes have come into use. It should be assessed how they affect soil and aquifer when spilled in leaks or accidents. This was simulated in a model system using methanol and percolation columns, one filled with material from the unsaturated subsurface and two with different materials from aquifers. The results reveal that a spill of the substitutes can also cause problems. In homogeneous soils and at long retention times until the substance reaches the aquifer, sorption and biological degradation are most likely to prevent contamination of the groundwater. When oxygen supply in the subsurface is insufficient, reducing conditions occur and sulphide is formed. The data show that much more methanol was eliminated than reflected by the consumption of electron acceptors. This indicates that sorption and anabolic turnover of the microorganisms play an ...

1993-04-01

47

Drying characteristics and nitrogen loss of biogas digestate during drying process  

Energy Technology Data Exchange (ETDEWEB)

The cost of transporting biogas digestate can be decreased by reducing its water content. However, the digestate emits volatile compounds during drying. This study investigated the drying behaviour and the change of digestate composition. Drying took place in a hybrid solar/waste-heat dryer that used solar energy as well as waste heat from a combined heat and power unit (CHP) and the exhaust air of a microturbine. The experiment involved the use of 60 t of liquid digestate. Climatic conditions were measured inside and outside the drying hall. Dry matter (DM) and organic dry matter (ODM) were also measured on a daily basis. In addition, the energy consumption of waste and solar heat were recorded and related to the quantity of dried feedstock. The total nitrogen, ammonium, phosphate, potassium oxide, magnesium oxide and calcium oxide in the digestate were subjected to chemical analysis before and after the drying process. Losses of nitrogen were ...

2010-07-01

48

Comparison of NH_4"+-N and NO_3"--N nutrition in hybrid and conventional rice at the late growth stage  

International Nuclear Information System (INIS)

The difference of NH_4"+-N/NO_3"--N nutrition between hybrid and conventional rice varieties at the late growth stage was studied by using "1"5N-tracer technique. The results showed that the nitrate fertilizer utilization efficiency by the hybrid rice after anthesis was 7.8% higher than that by the ordinary rice variety, and the nitrate fertilizer recovery fraction by the former was 13.2% greater than that by the latter. The varietal difference in NO_3"--N uptake and utilization was almost twice as that in NH_4"+-N. It was also showed that "1"5N distribution in ear of the hybrid rice was about 20% greater than that of the conventional variety, but there were no obvious differences between NO_3"--N and NH_4"+-N. However, "1"5N distribution in the lower node leaves and root was found to be significant higher with NO_3"--N than that with NH_4"+-N in both rice varieties, particularly in the hybrid rice. Compared with NH_4"+-N, NO_3"--N top-dressing before anthesis was observed to have much ...

49

Development of plasticity processing of magnesium alloys  

Energy Technology Data Exchange (ETDEWEB)

Recent developments on plastic forming technology of magnesium alloys are presented. Attempts have been undergoing with an aim at forming magnesium alloy parts at lower temperatures. It is believed that fine microstructure magnesium alloys usually have much higher plasticity at lower temperatures and even room temperatures. Extrusion is a method to form magnesium profile products and tube products, which is also one of the effective ways to make fine microstructure magnesium alloys. Superplasticity forming is another method to form high plasticity magnesium alloys. Hot forming of magnesium sheet parts is an important process to form magnesium products. Some developments related to above issues are discussed in the present paper. (orig.)

2003-07-01

50

Synthesis of ceramic powders by novel microwave-hydrothermal processing  

Energy Technology Data Exchange (ETDEWEB)

Microwave-hydrothermal processing was compared with conventional hydrothermal processing in the crystallization of hematite from 1M ferric nitrate and hydroxyapatite from calcium oxide and phosphoric acid. Microwave-hydrothermal processing led to the crystallization of hematite while convention-hydrothermal process led to the crystallization of a mixture of goethite and hematite under the same temperature conditions. Thus the crystallization of hematite which is the stable iron oxide phase at high temperatures has been catalyzed by microwaves. Microwave-hydrothermal processing also led to highly crystalline hydroxyapatite powders compared to the conventional hydrothermal processing which also points to the catalytic role of microwaves. The microwave induced effects may be attributed to the generation of localized high temperatures at the reaction sites which enhance reaction rates.

1996-06-01

51

Development of a pozzolanic pigment from red mud  

Energy Technology Data Exchange (ETDEWEB)

Red mud is a waste generated by the aluminum industry, and its disposal is a major problem for this industry. Very rich in iron, it can be used as cheap pigment for colored concrete. The red coloration can be enhanced by calcination in the range of 600 to 800 C. Such operation also transforms the aluminum hydroxides (goethite and boehmite) and clays minerals into pozzolanic admixtures that are able to consume the calcium hydroxide produced by cement hydration. Thus, it is possible to develop a new admixture for concrete: a pozzolanic pigment. The pozzolanic properties of calcined red mud were investigated by monitoring lime consumption of different mixtures of OPC and red mud. The main products of hydration were C-S-H and mono-carboaluminate (C{sub 4}A{bar C}H{sub 11}). A uniform and durable colored concrete was obtained using white cement interground with 11% of burnt red mud.

1997-10-01

52

Catalytic desulfurization of organic sulfur compounds over zeolite catalysts  

Energy Technology Data Exchange (ETDEWEB)

In the dehydrodesulfurization of ethanethiol at 400/sup 0/C, the activities of sodium X, Y, and A zeolites decreased in the order given as did the activities of nickel, cobalt, zinc, cadmium, copper, silver, lead, manganese, barium, calcium, sodium, and iron Y zeolite catalysts. A volcano-shape order was observed between the catalytic activity and the electronegativity of the metal ions. The changes in the activity of hydrogen Y zeolite catalyst in ethanethiol dehydrodesulfurization and cumene dealkylation by calcination agreed with the decrease in the Broensted acidity but were independent of Lewis acidity. For hydrodesulfurization of thiophene, the activities of nickel, cobalt, copper, and silver Y zeolite catalysts decreased in the order given and were greater than for a commercial hydrodesulfurization catalyst; reduced and presulfided catalysts showed selective hydrodesulfurization activity. Addition of 5% of nickel or molybdenum oxides to ...

1980-01-01

53

Anion capture with calcium, aluminium and iron containing layered double hydroxides  

British Library Electronic Table of Contents (United Kingdom)

The competitive adsorption of nitrate, chloride and carbonate in layered double hydroxides (LHD) with the general formula Formula Not Shown was investigated. Both normal ion exchange by exposure to a solution containing different anions, as well as addition of calcined material to solution thereby exploiting the memory effect of LDHs was studied. Changes in the interlayer anion changed the interlayer spacing of the LDH. The order of preference of intercalation was Formula Not Shown . When multiple anions were present in the exchange solution, LDHs with several distinct interlayer spacing were produced indicating that LDHs with different anions in the interlayer existed at the same time. However for extended exchange times (14days) where high concentrations of carbonate anion were present, ...

2011-01-01

54

Iron Therapy for Preterm Infants  

UK PubMed Central (United Kingdom)

SYNOPSISPreterm infants are at risk for both iron deficiency and iron overload. The role of iron in multiple organ functions suggests that iron supplementation is essential for...Full Text Available

2009-03-01

55

Fasting plasma magnesium concentrations and glucose disposal in diabetes.  

UK PubMed Central (United Kingdom)

Fasting plasma concentrations of magnesium were measured by neutron activation analysis in 30 non-diabetics and 87 diabetics (55 non-insulin-treated, 32 insulin treated). Plasma concentrations of magnesium...Full Text Available

1984-04-07

56

Surface modification of magnesium base alloys by gas/plasma nitridation  

Energy Technology Data Exchange (ETDEWEB)

Gas and plasma nitriding processes were executed in the magnesium with modification by titanium in search for an effective surface treatment method for magnesium alloys. Magnesium-nitrogen system has completely no solid solution or solubility, so that nitride should be only formed by eutectic reaction in the liquid phase. Hence, magnesium is difficult or nearly impossible to have its surface modified by nitriding. Addition of nitride forming element into magnesium enables us to lower the onset temperature of nitriding. Magnesium-titanium alloys with 1 to 5 wt% are yielded by the bulk mechanical alloying and, subjected to gas nitriding for various process conditions. Successful co-formation of Mg{sub 3}N{sub 2} as well as TiN becomes a proof to demonstrate the possibility of gas/plasma nitriding in the solid-state magnesium with aid of ...

2000-07-01

57

Comparison of Nutrient Content and Cost of Home-Packed Lunches to Reimbursable School Lunch Nutrient Standards and Prices  

Science.gov (United States)

Purpose: The purpose of this study was to compare nutrient content and cost of home-packed lunches to nutrient standards and prices for reimbursable school lunches. Methods: Researchers observed food and beverage contents of 333 home packed lunches at four north Texas elementary schools. Nutritionist Pro was used to analyze lunches for calories, total fat, saturated fat, protein, fiber, vitamin A, vitamin C, calcium, iron, fiber, and sodium content. These values were then compared to National School Lunch Program (NSLP) standards and other nutrient standards. Cost of each home-packed lunch was estimated based on food prices at three local supermarkets. A one-sample t-test (p = 0.05) was used to compare nutrient values of home packed lunches to National School Lunch Program (NSLP) standards. A paired t-test was used to compare cost of home packed lunches to each school's full price for a reimbursable school lunch. Results: Home packed lunches ...

2008-12-01

58

Study on the correlation between chemical and mineral composition of coal ashes; Sekitanbaibun no kobutsu soseigakuteki kento kagakubutsu sosei to kobutsugakuteki sosei no sokan  

Energy Technology Data Exchange (ETDEWEB)

Coal ash is a substance that has been mixed into minerals in the earth`s crust during their coalification process. Estimation was made on what kinds of mineral composition have been mixed into coals. Noted first was the kinds of compounds contained in the ash, wherein the ratios of mass in the compounds and minerals were correlated, and selection was made on minerals which are thought correlated. The selection criterion was based on minerals containing silica, alumina, iron oxide, lime and magnesium as compounds. Then, a phase equilibrium line diagram was used to estimate compositions and melting points of minerals which are thought to have been produced from these compounds. By comparing the estimation with the measured melting points of the ashes, mineral compositions thought reasonable were all selected. Assumption was possible on minerals that are thought to have been transferred into coal ash. Compound indications of ashes from 29 kinds of ...

1996-10-28

60

Augmented behavioral response and enhanced synaptosomal calcium transport induced by repeated cocaine administration are decreased by calcium channel blockers  

UK PubMed Central (United Kingdom)

Recent studies suggest that calcium influx via L-type calcium channels is necessary for psychostimulant-induced behavioral sensitization. In addition, chronic amphetamine upregulates subtype...Full Text Available

2007-07-26

61

Magnesium foam produced from bulk AZ31 magnesium alloy sheets  

Energy Technology Data Exchange (ETDEWEB)

Using commercial AZ31 magnesium alloy sheets, we produced a foamable preform sheet containing titanium hydride (TiH{sub 2}) powder through diffusion-bonding and hot-rolling of four cycles. Heating the preform sheets in Ar atmosphere, we obtained closed-cell magnesium alloy foams with various porosities. The foamed specimen at 883 K showed the maximum porosities of 77%. (orig.)

2005-07-01

62

I. Introduction  

Wastenet

as a by-product during the purification of molten magnesium chloride prior to its electrolysis and during the

64

BC  

Wastenet

as a by-product during the purification of molten magnesium chloride prior to its electrolysis and during the

65

Fatigue of magnesium alloys  

Energy Technology Data Exchange (ETDEWEB)

Magnesium alloys show a high specific strength and are therefore increasingly used for light-weight constructions in transportation industry.{sup [1,2]} To predict the behaviour of the material under the influence of cyclic loading it is vital to understand the fatigue behaviour of magnesium alloys. Only when understood properly, it is possible to fully apply the potential weight reduction by using magnesium alloys. A very important aspect in fatigue of magnesium alloys is the influence of a corrosive media and elevated temperatures, of which both are relevant in automotive applications. These two factors tend to have deleterious effects on magnesium alloys and therefore also have to be considered in investigations on the fatigue behaviour of magnesium alloys. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

2004-05-01

66

Materials used in new generation vehicles: supplies, shifts, and supporting infrastructure  

Energy Technology Data Exchange (ETDEWEB)

The Partnership for a New Generation of Vehicles (PNGV) program intends to develop new designs for automobiles that will reduce fuel consumption by two thirds but otherwise have price, comfort, safety, and other measures of performance similar to the typical automobile now on the market. PNGV vehicle designs are expected to substitute lightweight materials, such as aluminum, magnesium, carbon-reinforced polymer composites, glass-reinforced polymer composites, and ultra- light steel, for heavier materials such as steel and iron in automobile components. The target mass of a PNGV vehicle is 1,960 pounds, as compared to the average current vehicle that weights 3,240 pounds. Other changes could include the use of different ferrous alloys, engineering changes, or incorporation of advanced ceramic components. Widespread adoption of these vehicle designs would affect materials markets and require concurrent development and adoption of supporting ...

1997-08-01

68

Acid mine drainage and its impact in the Black Creek watershed, Virginia  

International Nuclear Information System (INIS)

A one-year study was conducted to determine the impacts of acid min drainage (AMD) on the Black Creek watershed in Wise County, Virginia. Water quality, metal content of sediment and water column, soil pH, macroinvertebrate assemblages, habitat assessment and toxicity testing were used to assess the impact in the watershed. A total of 22 sites in the creek and surrounding watershed were actively monitored. This included six primary sources of AMD. Conductivity measurements > 1,000 microhmos/cm were found at eight sites and pH was consistently below 6.0 at seven. Of six metals analyzed, magnesium was highest in the water column, ranging from 16.5 mg/L to 130 mg/L. Aluminum and iron were both elevated in the sediment with iron concentrations as high as 176,000 mg/kg. An increase in sediment metal concentrations was noted when progressing downstream in the creek. Of nine high wall and spoils areas sampled, soil pH was ...

1996-11-17

69

Carbon tetrachloride-induced release of calcium from isolated hepatocytes  

International Nuclear Information System (INIS)

Studies have shown that CCl_4 administration to rats inhibits endoplasmic reticulum calcium pump activity and reduces the amount of calcium associated with subsequently isolated microsomal subcellular fractions. This report confirms that exposure of isolated hepatocytes to CCl_4 rapidly produces these effects in isolated parenchymal cells and demonstrates that when isolated hepacytes are exposed to CCl_4 calcium is rapidly released from cells. This release can be detected with a calcium ion-selective electrode when cells are incubated in a medium with low extracellular calcium. Calcium released from an intracellular pool(s) may initiate hepatotoxic changes in liver. (author).

70

Waste treatment process for removal of contaminants from aqueous, mixed-waste solutions using sequential chemical treatment and crossflow microfiltration, followed by dewatering  

Energy Technology Data Exchange (ETDEWEB)

In processes of this invention aqueous waste solutions containing a variety of mixed waste contaminants are treated to remove the contaminants by a sequential addition of chemicals and adsorption/ion exchange powdered materials to remove the contaminants including lead, cadmium, uranium, cesium-137, strontium-85/90, trichloroethylene and benzene, and impurities including iron and calcium. Staged conditioning of the waste solution produces a polydisperse system of size enlarged complexes of the contaminants in three distinct configurations: water-soluble metal complexes, insoluble metal precipitation complexes, and contaminant-bearing particles of ion exchange and adsorbent materials. The volume of the waste is reduced by separation of the polydisperse system by cross-flow microfiltration, followed by low-temperature evaporation and/or filter pressing. The water produced as filtrate is discharged if it meets a specified target water quality, or ...

1994-01-01

71

Waste treatment process for removal of contaminants from aqueous, mixed-waste solutions using sequential chemical treatment and crossflow microfiltration, followed by dewatering  

Energy Technology Data Exchange (ETDEWEB)

In processes of this invention aqueous waste solutions containing a variety of mixed waste contaminants are treated to remove the contaminants by a sequential addition of chemicals and adsorption/ion exchange powdered materials to remove the contaminants including lead, cadmium, uranium, cesium-137, strontium-85/90, trichloroethylene and benzene, and impurities including iron and calcium. Staged conditioning of the waste solution produces a polydisperse system of size enlarged complexes of the contaminants in three distinct configurations: water-soluble metal complexes, insoluble metal precipitation complexes, and contaminant-bearing particles of ion exchange and adsorbent materials. The volume of the waste is reduced by separation of the polydisperse system by cross-flow microfiltration, followed by low-temperature evaporation and/or filter pressing. The water produced as filtrate is discharged if it meets a specified target water quality, or ...

1994-11-22

72

Desorption of uranium from titanium-activated carbon composite adsorbent with acidic eluent, 2  

Energy Technology Data Exchange (ETDEWEB)

The desorption of uranium from the granular titanium-activated carbon composite adsorbent (concentration of uranium: 25.5 mg/l-Ad), which adsorbed uranium from natural sea water, was examined by the column process with acidic eluent at room temperature. The column operation was able to be carried out without destruction of the granular adsorbent by the generation of the carbon dioxide, and free from disturbance of the eluent flow by precipitate of calcium sulfate dihydrate with sulfuric acid eluent. The amount of acid consumption by the adsorbent was 0.87 eq/l-Ad. The alkaline earth metals were eluted in the range of elution volume below 2l/l-Ad, whereas uranium, iron, and titanium were eluted above 2l/l-Ad. Therefore, uranium was separable from the alkaline earth metals which were adsorbed in the most quantity in the adsorbent. In the range of elution volume 2 to 12l/l-Ad, the percentage of desorbed uranium and the concentration ratio of ...

1984-01-01

73

A study of the breakdown of the quasi-static approximation at high densities and its effect on the helium-like K ALPHA complex of nickel, iron, and calcium  

CERN Document Server

The General Spectral Modeling (GSM) code employs the quasi-static approximation, a standard, low-density methodology that assumes the ionization balance is separable from a determination of the excited-state populations that give rise to the spectra. GSM also allows for some states to be treated only as contributions to effective rates. While these two approximations are known to be valid at low densities, this work investigates using such methods to model high-density, non-LTE emission spectra and determines at what point the approximations break down by comparing to spectra produced by the LANL code ATOMIC which makes no such approximations. As both approximations are used by other astrophysical and low-density modeling codes, the results should be of broad interest. He-like K$\\alpha$ emission spectra are presented for Ni, Fe, and Ca, in order to gauge the effect of both approximations employed in GSM. This work confirms that at and above the temperature of maximum abundance of the ...

2007-01-01

74

A radionuclide analyzer of total sulfur in coal  

International Nuclear Information System (INIS)

The devised radionuclide analyzer for the determination of total sulfur in coal includes two radionuclide sources with different energies, which are accommodated in collimators fitted with adjustable diaphramgs. The sample compartment is located between the two sources. Moreover, an X-ray fluorescence standard can be slid into the sample compartment. A proportional detector for X-ray fluorescence and scattered gamma radiation is located off the sample compartment. The input of the proportional detector is interfaced to the output of a high-voltage supply, the output, to the information input of a control-and-evaluation unit. One of the control outputs of the control-and-evaluation unit is connected to the input of the sliding mechanism for the X-ray fluorescence standard. This arrangement enables automatic energy calibration of the analyzer. The analyzer can measure not only total sulfur in coal by radionuclide X-ray fluorescence analysis but also ash in coal by the method of ...

1987-05-13

75

Vacuum distillation refining and recycling of magnesium alloys  

Energy Technology Data Exchange (ETDEWEB)

Purification parameters of the vacuum distillation process for AM50A and AZ31B magnesium alloy were studied. The vacuum distillation tests were kept at 580 C to 620 C up to 10 h under a vacuum pressure of about 1 Pa. The purification ratio for AM50A magnesium alloy increases with increasing the purification time. The chemical compositions of materials deposited purifying at 580 C for AM50A magnesium alloy almost satisfy the values for pure magnesium specified by JIS standard specification. The chemical compositions of deposited materials at 600 C for AZ31B magnesium alloy satisfy the values specified by the standard specification except for Zn. (orig.)

2003-07-01

76

Forming characteristics of cast magnesium alloy sheets manufactured by roll strip casting process  

Energy Technology Data Exchange (ETDEWEB)

Plastic formability of cast magnesium alloy that were hot rolled after roll strip casting was investigated to ascertain the feasibility of semi-solid strip casting process of AZ31B magnesium alloy. Hot rolling and heat treatment conditions were changed to examine which conditions were appropriate for producing AZ31B wrought magnesium alloys after strip casting process. Microscopic observation of the crystals of the manufactured wrought magnesium alloys was performed. It has been found that a limiting drawing ratio of 2.7 was possible in a warm deep drawing test of the cast magnesium alloy sheets after being hot rolled. (orig.)

2004-07-01

77

Effects of rolling condition on warm deep drawability of magnesium alloy sheets produced by twin-roll strip casting  

Energy Technology Data Exchange (ETDEWEB)

Effects of rolling conditions on warm deep drawability of cast magnesium alloy that were hot rolled after roll strip casting were investigated to ascertain the feasibility of twin-roll strip casting process of AZ31B magnesium alloy. Hot rolling and heat treatment conditions were changed to examine which conditions were appropriate for producing AZ31B wrought magnesium alloys after strip casting process. Microscopic observation of the crystals of the manufactured wrought magnesium alloys was performed. It has been found that a limiting drawing ratio of 2.7 was possible in a warm deep drawing test of the cast magnesium alloy sheets after being hot rolled. (orig.)

2005-07-01

78

Uptake, transport, and storage of calcium and magnesium in spruce (Picea abies [L]Karst.) and pine (Pinus silvestris L.) as affected by variable nutrition and pollutant stress  

International Nuclear Information System (INIS)

Statements about the dynamic processes of uptake, transport, and deposition of Ca and Mg in norway spruce and Scots pine are made in this paper. Concerning the storage of these elements it is shown that there are great differences in their functional importance in cell metabolism. There is evidence that the role of Mg in enzyme and protein metabolism is of far greater significance for the understanding of Mg-deficiency symptoms than its function as the central atom of the chlorophyll complexes. In regard to the transport and especially to the incorporation of Ca into the needles differences between species were evident, expressing the special status of pine among the gymnosperms. With increasing needle age an accumulation of Ca-oxalate crystals, which are physiologically inert, could be proved for the studied conifers. This was interpreted as a 'detoxication' from surplus Ca to hold constant the level of the physiologically active fraction. Accordingly, the low Ca-contents of yellowed ...

79

Ecological risk assessment of the east branch, Finniss River  

International Nuclear Information System (INIS)

Quantitative ecological risk assessment (ERA) is a means whereby the risk posed by a toxicant in any system can be evaluated by comparing the distribution of its measured or modelled concentrations (water quality data (WQD)) with available information on the range of concentrations that are known to adversely affect biota within that, or similar, habitats (dose-response data (DRD)). Initially, the WQD are compared with regulatory criteria (e.g. ANZECC and ARMCANZ, 2000). If they fail this test, then, on the assumption that both data sets comprise subsets of the entire range of concentrations, probability density functions are derived assuming a standard distribution form a typically log-normal. In this paper, AQUARISK has been used to estimate the risk posed by copper in effluent from the Rum Jungle mine site, pre- and post-remediation, and the proportion of taxa likely to be affected in the East Branch (EB) of the Finniss River downstream of the mine. In addition, the average ...

2002-03-01

80

Spatiotemporal intracellular calcium dynamics during cardiac alternans  

UK PubMed Central (United Kingdom)

Cellular calcium transient alternans are beat-to-beat alternations in the peak cytosolic calcium concentration exhibited by cardiac cells during rapid electrical stimulation or under pathological conditions....Full Text Available

2009-09-01

81

Sodium/Calcium Exchangers Selectively Regulate Calcium Signaling in Mouse Taste Receptor Cells  

UK PubMed Central (United Kingdom)

Taste cells use multiple signaling mechanisms to generate appropriate cellular responses to discrete taste stimuli. Some taste stimuli activate G protein coupled receptors (GPCRs) that cause calcium...Full Text Available

2010-07-01

82

Role of plasma membrane calcium ATPase 2 in spinal cord pathology  

UK PubMed Central (United Kingdom)

A number of studies have indicated that plasma membrane calcium ATPases (PMCAs) are expressed in the brain and spinal cord and could play important roles not only in the maintenance of cellular calcium...Full Text Available

2010-05-26

83

Hypertrophy and Heart Failure in Mice Overexpressing the Cardiac Sodium-Calcium Exchanger  

UK PubMed Central (United Kingdom)

Background:The cardiac sodium–calcium exchanger (NCX1) is a key sarcolemmal protein for the maintenance of calcium homeostasis in the heart. Since heart failure...Full Text Available

2007-05-01

84

Demographic, Dietary, and Urinary Factors and 24-h Urinary Calcium Excretion  

UK PubMed Central (United Kingdom)

Background and objectives: Higher urinary calcium is a risk factor for nephrolithiasis. This study delineated associations between demographic, dietary, and urinary factors and 24-h urinary calcium.Design,...Full Text Available

2009-12-01

85

Calcium Requirements and Metabolism in Chinese-American Boys and Girls  

UK PubMed Central (United Kingdom)

Calcium requirements of North American adolescents were set at 1300 mg/day based on data from white girls. Calcium requirements for Asian-American adolescents have not been studied. Using metabolic...Full Text Available

2010-08-01

86

Reduction in blood pressure with a low sodium, high potassium, high magnesium salt in older subjects with mild to moderate hypertension.  

UK PubMed Central (United Kingdom)

OBJECTIVE--To examine the effect of a reduced sodium and increased potassium and magnesium intake on blood pressure. DESIGN--Randomised double blind placebo controlled trial. SETTING--General population...Full Text Available

1994-08-13

87

Effect of calcium and phosphorus on the gastrointestinal absorption of /sup 203/Pb in man  

Energy Technology Data Exchange (ETDEWEB)

Calcium and phosphorus were mainly responsible for reducing the gastrointestinal absorption of lead in human subjects. The effect of calcium was greater than phosphorus, and their combined effect was more than additive. Increasing weights of calcium and phosphorus progressively reduced lead absorption. The relationship between absorption and increasing weights could be described by two negative exponentials. These effects could be explained if lead competed with calcium and phosphorus for common transport mechanisms in the gut. Milk was also found to reduce lead absorption. Adding milk to the diet of people with low dietary calcium intake could reduce the possibility of increased absorption of ingested lead.

1983-02-01

88

Preliminary delineation of natural geochemical reactions, Snake River Plain aquifer system, Idaho National Engineering Laboratory and vicinity, Idaho  

Energy Technology Data Exchange (ETDEWEB)

The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, is conducting a study to determine the natural geochemistry of the Snake River Plain aquifer system at the Idaho National Engineering Laboratory (INEL), Idaho. As part of this study, a group of geochemical reactions that partially control the natural chemistry of ground water at the INEL were identified. Mineralogy of the aquifer matrix was determined using X-ray diffraction and thin-section analysis and theoretical stabilities of the minerals were used to identify potential solid-phase reactants and products of the reactions. The reactants and products that have an important contribution to the natural geochemistry include labradorite, olivine, pyroxene, smectite, calcite, ferric oxyhydroxide, and several silica phases. To further identify the reactions, analyses of 22 representative water samples from sites tapping the Snake River Plain aquifer system were used to determine the thermodynamic condition of ...

1997-05-01

90

Extraction of magnesium as the iodide by tributyl phosphate  

Science.gov (United States)

The extraction of magnesium by tributyl phosphate from KI solutions was investigated. With increasing KI and TBP concentrations, the extraction increased. The maximum extraction (82%) was attained at pH 4, and it did not decrease with a further pH increase. With decreasing pH, the extraction decreased because of HI extraction. The magnesium was extracted as the compound MgI/sub 2/ x 4TBP. Complexone III (at pH 3-4) does not affect the extraction of magnesium, which makes it possible to use it to mask other metals.

1987-08-20

91

Refilling Intracellular Calcium Stores  

UK PubMed Central (United Kingdom)

Within the cardiac cell, the movements of calcium ions are tightly regulated by a number of regulatory proteins including pumps, and channels. The sarcoplasmic reticulum (SR) is in large part...Full Text Available

2010-01-01

92

Calcium-Actin Waves and Oscillations of Cellular Membranes  

UK PubMed Central (United Kingdom)

AbstractWe propose a mechanism for the formation of membrane oscillations and traveling waves, which arise due to the coupling between the actin cytoskeleton and the calcium flux through...Full Text Available

2009-09-16

94

The influence of process parameters on forged magnesium alloys  

Energy Technology Data Exchange (ETDEWEB)

Two extruded magnesium alloys, AZ31 and AZ61 were selected to evaluate the influence of process parameters on the material forgeability. The processing parameters considered for forging magnesium alloys were: compression load in the range 55 KN to 60 KN and forging temperature, in the range of ambient temperature to 300 C. Uniaxial compression tests were conducted to establish the strain-temperature relationship. The influences of process parameters on the microstructure were also evaluated. (orig.)

2003-07-01

95

Influence of rolling conditions on the microstructure and mechanical properties of magnesium sheet AZ31  

Energy Technology Data Exchange (ETDEWEB)

Two aspects of the deformation behavior of magnesium sheets are the subject of this paper. First it will give a mechanical characterization of a commercial magnesium with a focus on the anisotropy and the possible microstructural causes of this behavior. The rolling process will be part of the second aspect. The aim is to show the influence of the parameters on the microstructure and texture and how this could affect the anisotropy in the rolled sheets. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

2003-12-01

96

Double-electron-capture cross section for I/sup +/ in a magnesium-vapor target  

Energy Technology Data Exchange (ETDEWEB)

Measurements of the double-electron-capture process in which a positive ion of iodine becomes a negative ion in a single collision with a magnesium atom are reported between 20 and 90 keV. The cross section is comparable to that for the rare gases and not as large as might be expected from a two-valence-electron atom. This process is probably insignificant in the production of negative ion beams using a magnesium-vapor target.

1987-06-15

97

Character of interaction of magnesium borates with water  

Energy Technology Data Exchange (ETDEWEB)

The nature of interaction of some boromagnesium minerals with water is studied, the main stages of interaction are established. The methods of thermo-gravimetric, X-ray phase and chemical analyses are applied to state intermediate and final phases of magnesium borate interaction with water. ''Preobrazhenskite'' - ''inderite'' paragenesis is established. The notion ''magnesium borate solubility'' is shown to be senseless.

1986-11-01

98

Absorption of plutonium in the iron-deficient rat  

International Nuclear Information System (INIS)

Iron deficiency did not enhance absorption of plutonium following intragastric gavage of rats. Absorption of plutonium citrate in both control and iron-deficient rats was about 0.03% of the administered dose.

1977-05-01

99

Tensile properties and bending formability of drawn magnesium alloy pipes  

Energy Technology Data Exchange (ETDEWEB)

Magnesium alloys are being increasingly utilized in a variety of fields as an alternative material to organic materials and aluminum alloys, owing to excellent properties. Those include low density, and excellent damping properties. When compared to organic materials, furthermore, Mg alloy excels at recyclability, heat radiation, and electromagnetic-shielding. Though most of magnesium alloy products are manufactured through die-casting and thixo-molding at present, the demand for the expanding of magnesium wrought alloy market is increasing. Taking full advantage of a drawing technique and applying it to the conventional extruded pipe, we have developed a new type of magnesium alloy pipe. The strength of the developed pipe is significantly higher than that of the conventional one, either extruded or die-casting. Some of the excellent properties were obtained from fundamental tests performed with the ...

2003-07-01

100

Machinability of magnesium alloy in ultra-precision diamond cutting  

Energy Technology Data Exchange (ETDEWEB)

This paper deals with an experimental study of ultra-precision diamond cutting of magnesium alloy (AZ31). In order to investigate the machinability such as the cutting force and the surface integrity and understand the problems in a micro cutting, the experiments on the diamond cutting of magnesium alloy and pure aluminum with an ultra-precision turning machine has been carried out. The machinability of magnesium alloy was compared with that of pure aluminum and discussed. Consequently, both the thrust force component and the surface roughness obtained by cutting of magnesium alloy became larger than that of pure aluminum. It was also found that the inclusions or the defects in the work material caused to generate the scratches on the finished surface and influenced the integrity of mirror surface. (orig.)

2003-07-01

101

Semi-solid twin-roll casting process of magnesium alloy sheets  

International Nuclear Information System (INIS)

An experimental approach has been performed to ascertain the effectiveness of semi-solid strip casting using a horizontal twin roll caster. The demand for light-weight products with high strength has grown recently due to the rapid development of automobile and aircraft technology. One key to such development has been utilization of magnesium alloys, which can potentially reduce the total product weight. However, the problems of utilizing magnesium alloys are still mainly related to high manufacturing cost. One of the solutions to this problem is to develop magnesium casting-rolling technology in order to produce magnesium sheet products at competitive cost for commercial applications. In this experiment, magnesium alloy AZ31B was used to ascertain the effectiveness of semi-solid roll strip casting for producing magnesium alloy sheets. The temperature of the ...

2004-06-10

113

Advancing Age Alters the Contribution of Calcium Release From Smooth Endoplasmic Reticulum Stores in Superior Cervical Ganglion Cells  

UK PubMed Central (United Kingdom)

In superior cervical ganglion (SCG) neurons calcium-induced calcium release (CICR), mediated by ryanodine receptors (RyRs), contributes to stimulation-evoked intracellular calcium ([Ca2+]i)...Full Text Available

2009-01-01

115

Serum hepcidin as a diagnostic test of iron deficiency in premenopausal female blood donors  

UK PubMed Central (United Kingdom)

BackgroundCurrently used indicators of iron status have limitations. Hepcidin, a key regulator of iron metabolism, is reduced in iron deficiency. We sought to determine the properties...Full Text Available

2011-08-01

116

Multiple mechanisms account for lower plasma iron in young copper deficient rats  

UK PubMed Central (United Kingdom)

Copper deficiency lowers brain copper and iron during development. The reduced iron content could be due to hypoferremia. Experiments were conducted to evaluate plasma iron and “ferroxidase”...Full Text Available

2008-06-01

117

Magnetic iron compounds in the human brain: a comparison of tumour and hippocampal tissue  

UK PubMed Central (United Kingdom)

Iron is a central element in the metabolism of normal and malignant cells. Abnormalities in iron and ferritin expression have been observed in many types of cancer. Interest in characterizing iron compounds...Full Text Available

2006-12-22

118

Evidence for Iron-Dependent Nitrate Respiration in the Dissimilatory Iron-Reducing Bacterium Geobacter metallireducens  

UK PubMed Central (United Kingdom)

The dissimilatory iron-reducing bacterium Geobacter metallireducens was found to require iron at a concentration in excess of 50 μM for continuous cultivation on nitrate. Growth...Full Text Available

2001-08-01

119

Carbon dioxide absorption mechanisms of sodium added to calcium oxide at high temperatures  

Energy Technology Data Exchange (ETDEWEB)

To apply the CO{sub 2} absorber at about 1000{sup o}C for integrated coal gasification combined cycle (IGCC) furnace, the reactions of calcium oxide and CO{sub 2} at high temperatures was examined. Calcium carbonate reacts with sodium hydrogen carbonate below 200{sup o}C and forms sodium-calcium complex carbonate. The sodium-calcium complex carbonate melts at 813{sup o}C, and the carbon dioxide absorption and discharge reversible reactions of calcium-oxide takes place via liquid at around 1000{sup o}C. Sintering of calcium oxide at high temperature has been successfully avoided by the addition of sodium.

2004-07-01

120

A sample preparation for quantitative determination of magnesium in individual lymphocytes by electron probe X-ray microanalysis.  

Science.gov (United States)

We present a sample preparation method for measuring magnesium in individual whole lymphocytes by electron probe X-ray microanalysis. We use Burkitt's lymphoma cells in culture as the test sample and compare X-ray microanalysis of individual cells with atomic absorption analysis of pooled cell populations. We determine the magnesium peak-to-local continuum X-ray intensity ratio by electron probe X-ray microanalysis and calculate a mean cell magnesium concentration of 39 +/- 19 mmol/kg dry weight from analysis of 100 cells. We determine a mean cell magnesium concentration of 34 +/- 4 mmol/kg dry weight by atomic absorption analysis of pooled cells in three cell cultures. The mean cell magnesium concentrations determined by the two methods are not significantly different. We find a 10% coefficient of variation for both methods of analysis and a 30% coefficient of variation in ...

1986-01-01

121

Plane-strain backward extrusion of AZ31 magnesium alloy  

Energy Technology Data Exchange (ETDEWEB)

Increase usage of magnesium components in the portable electronics industries has propelled considerable research interest on the development of magnesium forging. There have been some studies done in the area of sheet metal forming and forging of axis-symmetrical parts of magnesium alloys but there are very little work done on the plane strain backward extrusion of magnesium alloy. This paper deals with the analysis of plane strain extrusion of magnesium alloy, AZ31, using numerical modeling at different extrusion conditions of temperatures and friction coefficients. A commercially available finite element package, ANSYS/LSDYNA, was used in the finite element analysis. FE simulated results, material deformation, punch force and stress/strain distributions, were compared with actual experimental data. From the numerical analysis, a decrease in forging temperature from 300 C to 250 C ...

2003-07-01

122

Numerical Modeling of Magnesium Alloy Sheet Metal Forming at Elevated Temperature  

International Nuclear Information System (INIS)

The development of light-weight vehicle is in great demand for enhancement of fuel efficiency and dynamic performance. The vehicle weight can be reduced effectively by using lightweight materials such as magnesium alloys. However, the use of magnesium alloys in sheet forming processes is still limited because of their low formability at room temperature and the lack of understanding of the forming process of magnesium alloys at elevated temperatures. In this study, uniaxial tensile tests of the magnesium alloy AZ31B-O at various temperatures were performed to evaluate the mechanical properties of this alloy relevant for forming of magnesium sheets. To construct a FLD (forming limit diagram), a forming limit test were conducted at temperature of 100 and 200 deg. C. For the evaluation of the effects of the punch temperature on the formability of a rectangular cup drawing with AZ31B-O, ...

2007-05-17

123

Lining of magnesium alloys with foils using shot peening  

Energy Technology Data Exchange (ETDEWEB)

To improve the surface properties of magnesium alloy, a lining process using shot peening was carried out. The lining of magnesium alloy with metals such as titanium and nickel is useful in heightening the corrosion and wear properties for the components. In the shot peening experiment, the foil set on the magnesium workpiece is pelted with many shots at a high velocity. The foil is bonded to the surface of the workpiece due to plastic deformation induced by the collision of the shots. A pure aluminum foil is inserted between the hard foil and magnesium workpiece to assist the bonding. To heighten the bondability, the foil and workpiece are heated and the flow stresses of the metals are reduced. In this experiment, a centrifugal shot peening machine with an electrical heater was employed. The workpieces were commercially magnesium alloys AZ31B and AZ91D, and the foils were ...

2003-07-01

124

Evaluation on the formability of magnesium alloy, AZ31  

Energy Technology Data Exchange (ETDEWEB)

Magnesium is known to have poor formability at room temperature, mainly attributed to its hexagonal lattice structure. This paper presents the findings generated from development of warm forming to produce thin-walled magnesium components. Finite element analysis was conducted to evaluate the formability of the material and the simulated results were compared to the tensile results and product formability. Tensile tests were used to verify the formability of the sheet metal at difference temperatures. The process parameters considered in the feasibility study were forming temperature, in the range of 28 C to 300 C and magnesium sheet (AZ31B-H24) thickness, in the range of 0.4 mm to 1 mm. Magnesium hand phone covers of a thickness down to 0.4 mm have been successfully produced. The feasible forming temperature was found to be between 200 C and 250 C. Metallographic examination shows evident of ...

2003-07-01

125

Damping measurements of the magnesium wrought alloys AZ31, AZ61 and AZ80 after indirect and hydrostatic extrusion  

Energy Technology Data Exchange (ETDEWEB)

Magnesium cast parts as well as indirectly and hydrostatically extruded profiles were used in order to investigate the influence of different microstructures on the damping behaviour of magnesium AZ-alloys. Especially, hydrostatic extrusion leads to a significant grain refinement in the extruded profile compared to indirect extrusion. Strain dependent damping measurements were carried out at room temperature using alloys AZ31, AZ61 and AZ80. Damping was determined as the logarithmic decrement of free bending beam vibrations. The results of these measurements after indirect and hydrostatic extrusion are shown and discussed. (orig.)

2005-07-01

126

Corrosion and protection of magnesium alloy AZ31D by a new conversion coating  

Energy Technology Data Exchange (ETDEWEB)

A chromium-free conversion coating for magnesium alloys were described. The conversion coating could be obtained when AZ31D magnesium alloy was immersed in a solution containing a manganese salt, phosphate and an inhibitor. Corrosion resistance of the chemical conversion coating was evaluated by anodizing polarization curve and salt immersion. XRD analysis showed that the conversion coating was mainly composed of Mn{sub 3}(PO{sub 4}){sub 2}. The morphology of the coating is observed by using SEM. The effect of electrolyte pH and concentration of inhibitor on coating growth are investigated. (orig.)

2003-07-01

127

A study on the grain refining effects of carbon inoculation by C{sub 2}Cl{sub 6} addition on AZ31 magnesium alloy  

Energy Technology Data Exchange (ETDEWEB)

The effects of carbon inoculation by C{sub 2}Cl{sub 6} addition were investigated using commercial AZ31 magnesium alloy. The additions of C{sub 2}Cl{sub 6} to AZ31 magnesium alloy significantly reduce the grain size from 280 {mu}m to about 120 {mu}m and the tensile properties are also increased due to grain refinement. EPMA analysis shows that Al-C-O compounds are formed in the castings which are considered to function as nucleants. (orig.)

2003-07-01

128

Thermophysical Properties of Matter - The TPRC Data Series. ...  

Science.gov (United States)

... alloys--Lanthanum-- Magnesium--Magnasium &11oy8--Hagn*31Uft compounds--Manxganese--Manganes. alloys-- Mercury ...

2011-05-14

129

The Effects of Magnesium on State 3 Respiration of Liver Mitochondria from Control and Cold-Acclimated Rats and Hamsters  

Science.gov (United States)

Increasing the Mg(2+) concentration results in a depression of succincoxidase-linked state 3

1978-01-01

130

Temperature Dependent Constitutive Modeling for Magnesium Alloy Sheet  

International Nuclear Information System (INIS)

Magnesium alloys have been increasingly used in automotive and electronic industries because of their excellent strength to weight ratio and EMI shielding properties. However, magnesium alloys have low formability at room temperature due to their unique mechanical behavior (twinning and untwining), prompting for forming at an elevated temperature. In this study, a temperature dependent constitutive model for magnesium alloy (AZ31B) sheet is developed. A hardening law based on non linear kinematic hardening model is used to consider Bauschinger effect properly. Material parameters are determined from a series of uni-axial cyclic experiments (T-C-T or C-T-C) with the temperature ranging 150-250 deg. C. The influence of temperature on the constitutive equation is introduced by the material parameters assumed to be functions of temperature. Fitting process of the assumed model to measured data is presented and the results are ...

2010-06-15

131

Surface modification on magnesium alloys by coating with magnesium fluorides  

Energy Technology Data Exchange (ETDEWEB)

A new technique has been developed for improving corrosion resistance on magnesium alloys. Specimens of AZ31 magnesium alloy were dipped into molten salt of NaBF{sub 4} at 723 K for various times, and then cooled, rinsed with water, and dried in air. Corrosion resistance in the surface treated specimens was evaluated by salt immersion test using 1% NaCl solution as a time for occurring filiform corrosion. On an un-treated AZ31 alloy, the time for starting the filiform corrosion was about 1.2 ks, while on the surface treated specimen, the time was prolonged into about 1300 ks. Moreover, the surface treated specimen showed corrosion resistance in low pH solutions, such as 1% HNO{sub 3} and HCl solutions. (orig.)

2005-07-01

132

Pore formation during hybrid laser-tungsten inert gas arc welding of magnesium alloy AZ31B--mechanism and remedy  

International Nuclear Information System (INIS)

One of the major concerns during high speed welding of magnesium alloys is the presence of porosity in the weld metal that can deteriorate mechanical properties. This study seeks to analyze the presence method and quantity of pore during hybrid laser-tungsten inert gas arc (TIG) welding of magnesium alloy AZ31B by radiography, optical microscopy and electron probe microanalysis (EMPA). At the same time, it identifies both the mechanism of pore formation and a remedy for this problem. The experimental results indicate that lacking of shielding gas for laser beam is the dominant cause of macroporosity formation during the hybrid of laser-TIG welding of magnesium Alloys AZ31B plate, and hydrogen is not main cause to form large pores. A favorable weld without porosity can be obtained by appending lateral shielding gas for laser beam.

2005-01-15

133

Pathogenesis of hypocalcemia in magnesium depletion  

UK PubMed Central (United Kingdom)

Hypocalcemia in the hypomagnesemic state in man is usually attributed to refractoriness of end-organs to the calcemic action of parathyroid hormone. We studied the responsiveness of end-organs to bovine...Full Text Available

1971-12-01

134

Friction welding of AZ31 magnesium alloy  

Energy Technology Data Exchange (ETDEWEB)

In this paper, for an acceleration of utilization of magnesium alloy which is being interested in recent years, friction welding of AZ31 magnesium alloy was carried out, and the joint performance was discussed in relation to the deformation heat input in the upset stage and upset loss as a evaluation factor. Where, the deformation heat input in the upset stage is mechanical work represented by the product of upset speed and axial pressure. As a result, it was made clear that the friction welding of AZ31 magnesium alloy was easy in the atmosphere, and good welded joints without a non- adhesion area at the weld interface could de obtained. Moreover, the evaluation factors discussed were possible to evaluate to joint performance. (orig.)

2003-07-01

135

Direct strip casting of magnesium  

Energy Technology Data Exchange (ETDEWEB)

A new interest in magnesium alloys has arisen since light-weight constructions have become more and more attractive. Products that are currently available are mostly cast, forged, and extruded. A cost-effective production of sheet metals will render new perspectives in the design of light-weight constructions. The development of new casting technologies like thin slab casting or strip casting with an in-line rolling process is expected to result in a shorter processing time featuring a high potential of saving energy, time, and cost. Particular attention is paid to the casting process parameters such as casting speed and solidification speed. This article deals with some aspects of a magnesium-adapted single-belt caster. Results of casting experiments and material examination are shown as well as some advices given concerning safety and handling of liquid magnesium. (orig.)

2004-12-01

136

Design and microstructural analysis of magnesium alloys for dynamical applications  

British Library Electronic Table of Contents (United Kingdom)

A microanalytical characterization of cast magnesium alloys of eutectic origin based on the Mg?Al?Ca ternary matrix system has been carried out in order to investigate the influence of alloying elements on their microstructure as well as microchemistry-processing-microstructural relations using structure-sensitive techniques of electron microscopy, mechanical spectroscopy (internal friction), X-ray diffractometry, and advanced microanalytical methods including electron probe compositional analysis. Following the data obtained here there is direct correlation of microstructure with creep properties of the new experimental magnesium alloys. The creep and heat-induced properties of the multicomponent magnesium alloys containing low range of inexpensive additions of titanium (0.07?0.2%) or str...

2011-01-01

137

Corrosion resistance in magnesium alloys and deposition coated magnesium alloy  

Energy Technology Data Exchange (ETDEWEB)

Corrosion behavior of deposition coated specimens prepared by the technique proposed by the authors is investigated in salt immersion tests, and also those of pure magnesium, 3N, 4N and 6N grades, and magnesium alloys, AZ31 and AZ91E, are investigated for comparison. Inhomogeneous corrosion occurs in AZ31 and AZ91E alloys when buffered solutions with pH values of 6.5 and 9.0 including 1% NaCl and a conventional 3% NaCl solution are used for immersion tests, while 6N-Mg shows homogeneous corrosion in such solutions. Corrosion behavior of the deposition coated specimen resembles that of 6N-Mg. Purification process included in the deposition coating technique provides homogeneity in microstructural and electrochemical terms, which results in improving corrosion resistance. (orig.)

2003-07-01

138

Compatibility of magnesium alloys with methanol-containing fuels  

Energy Technology Data Exchange (ETDEWEB)

Although magnesium is not attacked by hydrocarbons, it reacts vigorously with anhydrous methanol, raising concerns about the compatibility of the metal with methanol blend fuels. This paper describes the behavior of magnesium alloys in laboratory tests in static contact with methanol-containing fuels at 110/sup 0/F. Water in small concentrations (above 0.25% by weight of the methanol content) is shown to prevent the destructive attack of magnesium by these fuels. The required water content is well within the water tolerance of methanol-GTBA (gasoline grade tertiary-butyl alcohol) cosolvent fuel blends. Die cast AZ91HP shows greater resistance to methanol reaction than does AZ31B sheet.

1986-01-01

139

A new technique for surface modification in magnesium alloys by applying magnesium oxide coating  

Energy Technology Data Exchange (ETDEWEB)

A new technique was proposed in order to improve poor corrosion resistance in magnesium. That is, magnesium hydroxide film was formed on the surface of 3 N-Mg by artificial corrosion in 1% MgCl{sub 2} solution for 3.6 ks, which followed by oxidation at 673 K for 3.6 ks in air. Corrosion resistance was evaluated by salt immersion tests in 1% NaCl solution under in situ laser microscopic observations. Bubble evolution, which occurred immediately at the beginning of the immersion test in the case of non-treated specimen, was suppressed by the process. And also, formation of filiform corrosion was suppressed for about 3.6 ks, which occurred at 180 s in the non-treated specimen. (orig.)

2003-07-01

140

A Subchronic Intravenous Toxicity Study of Magnesium Fructose-1,6-Diphosphate in Beagle Dogs  

British Library Electronic Table of Contents (United Kingdom)

Magnesium fructose-1,6-diphosphate is a novel agent of antimyocardial ischaemia. In the present study, the subchronic toxicity of magnesium fructose-1,6-diphosphate was investigated after 13-week repeated intravenous administration in beagle dogs. The animals received doses of 0, 75, 150 and 300 mg/kg/day (three males and three females for each dose). During the study period, clinical signs, mortality, body weights, food consumption, electrocardiogram, urinalysis, haematology, clinical biochemistry, macroscopic findings, organ weights and histopathology were examined. The administration of magnesium fructose-1,6-diphosphate resulted in increased incidence of clinical signs, including salivation and emesis. These effects were transient and were noted in almost all dogs given 300 mg/kg/day a...

2009-01-01

141

Rapid laser fluorometric method for the determination of uranium in soil, ultrabasic rock, plant ash, coal fly ash and red mud samples  

International Nuclear Information System (INIS)

A simple and rapid laser fluorometric determination of trace and ultra trace level of uranium in a wide variety of low uranium content materials like soil, basic and ultra basic rocks, plant ash, coal fly ash and red mud samples is described. Interference studies of some common major, minor and trace elements likely to be present in different geological materials on uranium fluorescence are studied using different fluorescence enhancing reagents like sodium pyrophosphate, orthophosphoric acid, penta sodium tri-polyphosphate and sodium hexametaphosphate. The accurate determination of very low uranium content samples which are rich in iron, manganese and calcium, is possible only after the selective separation of uranium. Conditions suitable for the quantitative single step extraction of 25 ng to 20 #mu#g uranium with tri-n-octylphosphine oxide and single step quantitative stripping with dilute neutral sodium pyrophosphate, which also acts as ...

1999-10-01

142

Element distribution in the brain sections of rats measured by synchrotron radiation X-ray fluorescence  

International Nuclear Information System (INIS)

The concentration of trace elements in brain sections was measured by synchrotron radiation X-ray fluorescence. The relative concentration was calculated by means of the normalization of Compton scattering intensity approximately 22 keV, after the normalization for collecting time of X-ray spectrum and the counting of the ion chamber, and subtracting the contribution of the polycarbonate film for supporting sample. Furthermore, the statistical evaluation of the element distribution in various regions of the brain sections of the 20-day-old rats was tested. For investigating the distribution of elements in the brain of iodine deficient rats, Wistar rats were fed with iodine deficient diet and deionized water (ID group). The rats were fed the same iodine deficient diet, but drank KIO_3 solution as control (CT group). The results showed that the contents of calcium (Ca) in thalamus (TH) and copper (Cu) and iron (Fe) in cerebral cortex (CX) of ID ...

2004-02-27

143

Meat factor peptides as a good iron source for vegetarians  

Environmental Research Database

DescriptionIron deficiency anaemia is a common problem and may be particularly important to certain groups of vegetarians. This project investigates isolating and identifying iron-binding constituents of meat digests using human Caco-2 cell lines. Stable isotope techniques used to test whether one or more of these compounds enhance iron absorpion in vivo and could therefore be added to vegetarian products to imporve iron nutrition.

2005-01-31

144

The role of calcium ions and calcium channel entry blockers in experimental ischemia-reperfusion-induced liver injury.  

UK PubMed Central (United Kingdom)

Verapamil administered before treatment, but not after treatment, had a beneficial effect on a 90-minute warm ischemia-reperfusion rat liver injury model. The possible activation of proteases converting...Full Text Available

1991-02-01

145

The Functional Role of Calcineurin in Hypertrophy, Regeneration, and Disorders of Skeletal Muscle  

UK PubMed Central (United Kingdom)

Skeletal muscle uses calcium as a second messenger to respond and adapt to environmental stimuli. Elevations in intracellular calcium levels activate calcineurin, a serine/threonine phosphatase, resulting...Full Text Available

2010-01-01

146

Strategies for the uses of lanthanide NMR shift probes in the determination of protein structure in solutio. Application to the EF calcium binding site of carp parvalbumin.  

UK PubMed Central (United Kingdom)

The homologous sequences observed for many calcium binding proteins such as parvalbumin, troponin C, the myosin light chains, and calmodulin has lead to the hypothesis that these proteins have homologous...Full Text Available

1980-10-01

147

Modulation of B-cell endoplasmic reticulum calcium homeostasis by Epstein-Barr virus Latent Membrane Protein-1  

UK PubMed Central (United Kingdom)

BackgroundCalcium signaling plays an important role in B lymphocyte survival and activation, and is critically dependent on the inositol-1,4,5-tris-phosphate-induced...Full Text Available

148

Mapping the Spatiotemporal Dynamics of Calcium Signaling in Cellular Neural Networks Using Optical Flow  

UK PubMed Central (United Kingdom)

An optical flow gradient algorithm was applied to spontaneously forming networks of neurons and glia in culture imaged by fluorescence optical microscopy in order to map functional calcium signaling...Full Text Available

2010-08-01

149

Hair Mercury Negatively Correlates with Calcium Pump Activity in Human Term Newborns and Their Mothers at Delivery  

UK PubMed Central (United Kingdom)

BackgroundCalcium homeostasis is a known target of several environmental toxicants including lead and mercury.ObjectiveOur goal was to determine...Full Text Available

2008-02-01

150

Ethoxylated Bisphenol Dimethacrylate-based Amorphous Calcium Phosphate Composites  

UK PubMed Central (United Kingdom)

Improving the anti-demineralizing/remineralizing and mechanical properties of amorphous calcium phosphate (ACP) composites has been the focus of our recent research. In this study, an ethoxylated...Full Text Available

2006-01-01

151

Effects of calcium supplementation on bone density in healthy children: meta-analysis of randomised controlled trials  

UK PubMed Central (United Kingdom)

Objectives To assess the effectiveness of calcium supplementation for improving bone mineral density in healthy children and to determine if any effect is modified by other factors and...Full Text Available

2006-10-14

152

Detrusor overactivity is associated with downregulation of large-conductance calcium- and voltage-activated potassium channel protein  

UK PubMed Central (United Kingdom)

Large-conductance voltage- and calcium-activated potassium (BK) channels have been shown to play a role in detrusor overactivity (DO). The goal of this study was to determine whether bladder outlet...Full Text Available

2010-06-01

153

Calcium, Vitamin D, VDR Genotypes, and Epigenetic and Genetic Changes in Rectal Tumors  

UK PubMed Central (United Kingdom)

Calcium, vitamin D, exposure to sunshine, and vitamin D receptor (VDR) genotypes have been associated rectal cancer. We used data from 750 rectal tumors and 1,205 population-based...Full Text Available

2010-05-01

154

Calcium - blood test: MedlinePlus Medical Encyclopedia  

Science.gov (United States)

Names Ca+2; Serum calcium; Ca++ References Wysolmerski JJ, Insogna KL. The parathyroid glands, hypercalcemia, and hypocalcemia. In: Goldman L, Ausiello D, eds. Cecil...

2011-08-30

155

A Comparison between Quin-2 and Aequorin as Indicators of Cytoplasmic Calcium Levels in Higher Plant Cell Protoplasts 1  

UK PubMed Central (United Kingdom)

Assessment of the regulation of plant metabolism by the calcium ion requires a knowledge of its intracellular levels and dynamics. Technical problems have prevented direct measurement of the concentration...Full Text Available

1989-06-01

156

17?-estradiol regulation of T-type calcium channels in gonadotropin-releasing hormone neurons  

UK PubMed Central (United Kingdom)

T-type calcium channels are responsible for generating low-threshold spikes that facilitate burst firing and neurotransmitter release in neurons. GnRH neurons exhibit burst firing, but the underlying...Full Text Available

2009-08-26

157

Investigation of new materials for SOFC applications; Untersuchungen zum Einsatz neuer Werkstoffe fuer SOFC-Anwendungen  

Energy Technology Data Exchange (ETDEWEB)

Fuel cells based on solid oxides ('SOFC') are excellent alternative devices for power generation, when they are operated at high temperature, e.g. above 600 C. Having only fixed parts for the power generating part of the device is only one advantage of the fuel cell. Due to their unique design, these devices offer a maximum of efficiency for energy conversion compared to conventional power generating systems, which are mainly based on turbines. One aim of this thesis is the examination of alternative electrolyte and cathode materials for the SOFC applications at reduced temperatures, which means in the temperature range between 600 C and 750 C. For the first main task, several materials from the oxygen ion conducting electrolytes were selected. Different strontium and magnesium doped lanthanum gallate (LSGM) materials with additional transition metal doping were selected and prepared via two different preparation methods. The optimum calcining ...

2007-05-04

159

Proceedings of ARO Workshop Biostructures as Composite ...  

Science.gov (United States)

... interactive surfaces and interfaces, and 3) the more complex a ... carbonate or calcium phosphate with a thin interface ... diameter) for nerve prosthesis. ...

1990-03-01

160

Well preflush fluid  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a preflush fluid for preventing lost circulation during the cementing of a well, the fluid consisting essentially of: (a) water; (b) about 10 to about 30 percent by weight of water (% BWOW) cement; (c) about 5 to about 30% BWOW calcium sulfate selected from the group consisting of calcium sulfate hemihydrate, calcium sulfate dihydrate, and mixtures thereof; and (d) an alkali metal-containing quick-hardening accelerator.

1992-01-21

161

Removal of noxious contaminants from gas  

Science.gov (United States)

Gas contaminated with at least one noxious component, such as SO/sub 2/, HF or NOx, is scrubbed with a clear, calcium-containing, initially-basic washing liquid which also comprises the anion of a strong inorganic acid, that of a polybasic carboxylic acid and, optionally, that of a monobasic carboxylic acid. Apparatus is provided for scrubbing the gas, oxidizing produced calcium bisulfite to calcium sulfate, separating out and removing solids, and recirculating clarified liquid for scrubbing contaminated gas.

1980-09-16

162

Calcium fluoride window mounting  

International Nuclear Information System (INIS)

A technique has been developed for joining a large calcium fluoride crystal to a stainless-steel flange by means of a silver transition ring. The process involves both vacuum brazing using a copper-silver alloy and air brazing using silver chloride. This paper describes the procedure used in fabricating a high-vacuum leak-tight calcium fluoride window assembly.

163

Transplantation of allogeneic T cells alters iron homeostasis in NOD/SCID mice  

UK PubMed Central (United Kingdom)

Iron overload is common in patients undergoing allogeneic hematopoietic cell transplantation (HCT), but the mechanisms leading to overload are unknown. Here, we determined iron levels and the expression...Full Text Available

2009-02-19

164

The effect of high ascorbic acid supplementation on body iron stores  

Energy Technology Data Exchange (ETDEWEB)

The level of assimilation of dietary iron is believed to have an important influence on iron status. To examine the effect of enhancing the availability of dietary iron on iron balance, 17 adult volunteer subjects were given 2 g of ascorbic acid daily with meals for 16 weeks. Serum ferritin levels before and after the study averaged 46 and 43 micrograms/L, respectively, indicating a negligible effect on iron stores. When vitamin C supplementation was continued for an additional 20 months in five iron-replete and four iron-deficient subjects, serum ferritin determinations again failed to indicate any significant effect of the vitamin C on iron reserves. These findings were not explained by intestinal adaptation to the enhancing effect of the vitamin, because radioisotopic measurements of nonheme iron ...

1984-09-01

165

Iron Metabolism in the Anaemia of Chronic Renal Failure. Effects of Dialysis and of Pareuteral Iron  

UK PubMed Central (United Kingdom)

Serial studies of iron transport in patients on maintenance dialysis showed normal or raised values in almost all subjects and a transient increase soon after the start of dialysis in three. These...Full Text Available

1969-07-26

166

Assessment of battery technologies for electric vehicles  

Energy Technology Data Exchange (ETDEWEB)

This document, Part 2 of Volume 2, provides appendices to this report and includes the following technologies, zinc/air battery; lithium/molybdenum disulfide battery; sodium/sulfur battery; nickel/cadmium battery; nickel/iron battery; iron/oxygen battery and iron/air battery. (FI)

1990-02-01

167

A small RNA promotes siderophore production through transcriptional and metabolic remodeling  

UK PubMed Central (United Kingdom)

Siderophores are essential factors for iron (Fe) acquisition in bacteria during colonization and infection of eukaryotic hosts, which restrain iron access through iron-binding protein, such as lactoferrin...Full Text Available

2010-08-24

168

Fabrication of magnesium alloy (AZ31) sheet by extrusion  

Energy Technology Data Exchange (ETDEWEB)

In order to investigate the extrusion characteristics of magnesium alloy (AZ31), a computer simulation was attempted. Tensile properties of as-cast billet with different strain rates were incorporated into the simulation. The results showed a great change in distribution of stress and strain at near die region by the ram travel. It was found that the average grain size at longitudinal edge of the extruded sheet was smaller than that at center region, which might be attributed to recrystallization caused by severe plastic deformation. (orig.)

2004-07-01

169

Deep drawing and impact extrusion of magnesium alloys at room temperature  

Energy Technology Data Exchange (ETDEWEB)

Magnesium alloys and composites are potentially highly attractive materials for lightweight design in the automotive industry - if common forming technologies, i.e., deep drawing and cold extrusion, are applicable to them; so far, this is seldom the case. The authors have tested some candidate Mg alloys and discuss the results of their measurements in detail. The Figure shows a typical workpiece part obtained by a deep-drawing technique. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

2003-04-01

170

A sample preparation for quantitative determination of magnesium in individual lymphocytes by electron probe X-ray microanalysis  

International Nuclear Information System (INIS)

We present a sample preparation method for measuring magnesium in individual whole lymphocytes by electron probe X-ray microanalysis. We use Burkitt's lymphoma cells in culture as the test sample and compare X-ray microanalysis of individual cells with atomic absorption analysis of pooled cell populations. We determine the magnesium peak-to-local continuum X-ray intensity ratio by electron probe X-ray microanalysis and calculate a mean cell magnesium concentration of 39 +- 19 mmol/kg dry weight from analysis of 100 cells. We determine a mean cell magnesium concentration of 34 +- 4 mmol/kg dry weight by atomic absorption analysis of pooled cells in three cell cultures. The mean cell magnesium concentrations determined by the two methods are not significantly different. We find a 10% coefficient of variation for both methods of analysis and a 30% coefficient of variation in ...

1986-01-01

171

The forming process of magnesium alloy for Japanese home electric components  

Energy Technology Data Exchange (ETDEWEB)

Magnesium alloys have replaced resins as a material for the components of electronic products such as cell phone and notebook personal computer mainly, because of their lightness and rigidity. Thin walls, a complicated shape, and high appearance quality are all needed in the external parts. Die-casting and injection molding are the main method of manufacturing magnesium alloy parts. The optimal cast conditions and mold design have been investigated in order that a few defects such as surface cracks and mold cavities in casting parts would be reduced. Instead of cast, plastic forming technologies such as warm drawing and hot forging have been developed to form thinner walls and less defects. Plastic formability of magnesium alloy in hot working is dependent on a grain size of material. The material with fine grains has advantage of being formed at high strain rate. The characteristics of forming processes of ...

2005-07-01

172

PVD-CrN coated magnesium alloy AZ91hp and steel 100Cr6 - investigation on the influence of the substrate material on coating properties; PVD-CrN Beschichtungen auf Magnesium AZ91hp und Stahl 100Cr6 - Untersuchung des Substrateinflusses auf die Schichteigenschaften  

Energy Technology Data Exchange (ETDEWEB)

PVD-chromium-nitride coated samples of substrates of the magnesium alloy AZ91hp and the roller and ball bearing steel 100Cr6 were investigated regarding structure, mechanical characteristics, adhesion and internal stresses. For the coatings the parameters layer thickness and substrate BIAS voltage were varied. Both substrate materials were coated in one lad. Results of the X-ray analysis of the internal stresses show significant differences between the coated magnesium and the coated steel substrates. In the case of the variation of the substrate BIAS voltage, for the coated steel a dependency of the internal stresses to coating parameters could be obtained. For the coated magnesium no dependency was recognizable. The coating structure was examined with scanning electron microscopy. Element depth profiles of the coated samples were performed with SIMS. (orig.)

2001-03-01

173

Fatigue properties of magnesium alloy under biaxial stress  

Energy Technology Data Exchange (ETDEWEB)

Machines and structures, such as automobiles are usually subjected to biaxial or three-axial stresses instead of uniaxial stress. However, research on a fatigue failure under multi-axial stress has not been fully presented because such experiments are difficult. To solve this problem, we developed the servo biaxial fatigue-testing machine. In this research, we performed the biaxial fatigue tests of a magnesium alloy in order to clarify the effects from different heat treatments. Magnesium alloy is the lightest in weight among metal materials for structural use. The fatigue characteristics of a magnesium alloy are indispensable in order to create the design which ensures the reliability and the safety of the vehicles especially in long-distance run. The main conclusions are summarized as follows; (1) The mechanical property of magnesium alloy AZ31B falls by heat treatment at low temperature. (2) The ...

2004-07-01

174

The hepcidin-binding site on ferroportin is evolutionarily conserved  

UK PubMed Central (United Kingdom)

SummaryMammalian iron homeostasis is regulated by the interaction of the liver-produced peptide hepcidin and its receptor, the iron transporter ferroportin. Hepcidin binds to...Full Text Available

2008-08-01

175

Inelastic electron scattering, M1 giant resonances and the quest for subnuclear degrees of freedom  

International Nuclear Information System (INIS)

... electrons fine structure giant resonance inelastic scattering iron 54 iron 54

1983-01-17

176

Differential responses of the freshwater wetland species Juncus effusus L. and Caltha palustris L. to iron supply in sulfidic environments  

British Library Electronic Table of Contents (United Kingdom)

Sulfur pollution can lead to serious problems in freshwater wetlands, including phosphorus eutrophication and sulfide toxicity. We tested the effects of anaerobic iron-rich groundwater discharge in fens, simulated by iron injection, on two characteristic species (Juncus effusus and Caltha palustris) in a sulfidic environment. Biomass production of C. palustris roots showed an optimum response to the combined addition of iron and sulfide, with highest values at intermediate concentrations of both substances. Iron deficiency apparently occurred at low iron concentrations, while at high iron concentrations, growth was decreased. For J. effusus, in contrast, no toxic effects were found of both iron and sulfide. This could be explained by larger radial oxygen loss (ROL) of J. effusus and could ...

2007-01-01

177

Creation of the iron-group elements in a supernova explosion  

Energy Technology Data Exchange (ETDEWEB)

The relative abundances of iron-peak elements produced by the e-process in a supernova outburst are calculated. The results agree quite well with the cosmic abundances of elements in the range Z=23--28.

1980-01-01

178

Characterization of the product of the thiosulfate process for desulfurization of flue gases  

Energy Technology Data Exchange (ETDEWEB)

X-ray diffraction, infrared spectroscopy, thermal analysis, scanning electron microscopy, and particle size analysis were used to characterize the product of the thiosulfate process. It was found to consist of a mixture of a solid solution of calcium sulfate in calcium sulfite hemihydrate, calcium sulfate dihydrate, and calcium carbonate. Reactions taking place on heating the byproduct were identified in oxidizing and reducing atmospheres. Pure calcium sulfite hemihydrate as well as solid solutions of CaSO[sub 4] in CaSO[sub 3] [center dot] (1/2)H[sub 2]O with different sulfate concentrations were synthesized in the laboratory. Thermal analyses of pure solid solutions proved that the higher the sulfate content, the higher is the dehydration temperature. Accordingly, taking SO[sub 4][sup 2[minus

1994-05-01

179

IMPROVED NATURAL GAS STORAGE WELL REMEDIATION  

Energy Technology Data Exchange (ETDEWEB)

This report summarizes the research conducted during Budget Period One on the project ''Improved Natural Gas Storage Well Remediation''. The project team consisted of Furness-Newburge, Inc., the technology developer; TechSavants, Inc., the technology validator; and Nicor Technologies, Inc., the technology user. The overall objectives for the project were: (1) To develop, fabricate and test prototype laboratory devices using sonication and underwater plasma to remove scale from natural gas storage well piping and perforations; (2) To modify the laboratory devices into units capable of being used downhole; (3) To test the capability of the downhole units to remove scale in an observation well at a natural gas storage field; (4) To modify (if necessary) and field harden the units and then test the units in two pressurized injection/withdrawal gas storage wells; and (5) To prepare the project's final report. This report covers activities ...

2001-12-01

180

Synthesis and physicochemical properties of iron (2) perrhenates  

Energy Technology Data Exchange (ETDEWEB)

By dissolution of iron (2) carbonate in rhenium acid iron (2) perrhenate of the Fe(ReO/sub 4/)/sub 2/x4H/sub 2/O composition is obtained. By the method of thermal analysis the limits of tetra-, dihydrate and anhydrous iron (2) perrhenate stability are revealed. By means of X ray phase and IR spectroscopic analysis methods modification of structure in the process of synthesized salt dehydration is shown.

1983-01-01

181

Surprising collectivity in neutron-rich iron isotopes  

International Nuclear Information System (INIS)

... VDPEAZ (Bonn 2010 issue) NUCLEAR PHYSICS AND RADIATION PHYSICS

2010-03-15

182

Reductive dechlorination of chlorinated solvents by zero-valent iron, iron oxide and iron sulfide minerals  

Energy Technology Data Exchange (ETDEWEB)

The degradation of chlorinated solvents by reduction at the surface of zero-valent metals and bimetallic systems has emerged as an important approach to the in-situ remediation of ground water. Reduction by iron metal was studied in batch and column systems to develop a mechanistic understanding of the reaction chemistry and to determine the factors that affect dechlorination rate and long term performance in field applications.

1996-10-01

183

Moessbauer studies of the molybdenum-iron-protein in the nitrogenase of Xanthobacter autotrophicus GZ 29. Moessbaueruntersuchungen am Molybdaen-Eisen-Protein der Nitrogenase von Xanthobacter Autotrophicus GZ 29  

Energy Technology Data Exchange (ETDEWEB)

Biological cells of the nitrogen fixating bacteria Xanthobacter autotrophicus GZ 29 have been cultivated with 57-Fe, and from the nitrogenase of these cells the 57-Fe marked molybdenum-iron-protein is extracted. The Moessbauer spectra of this enzyme show that the structure of the iron cluster is similar to the structure in the molybdenum-iron-proteins of Azotobacter vinelandii, Klebsiella pneumoniae or Clostridium pasteurianum.

1983-05-01

184

Iron in cookies prepared with fortified flour  

International Nuclear Information System (INIS)

... Italy) Istituto Superiore di Sanita (Italy) 207 p. ENVIRONMENTAL SCIENCES

2009-04-01

185

Dioxins in the Baltic sea  

Wastenet

for municipal waste iron ore sinter plants incinerators for clinical waste facilities of the non-ferrous metal

187

Coated Superalloys for Power Installations  

International Science & Technology Center (ISTC)

Characterization and Testing of Coated Nickel- and Iron-Based Superalloys for Application in High-Temperature Power Installations

188

Responses of the toxic cyanobacterium Microcystis aeruginosa to iron and humic substances  

British Library Electronic Table of Contents (United Kingdom)

Iron is an essential element to marine biota. Different types of dissolved organic matter (DOM), such as humic substances have impacts on the marine coastal waters iron chemistry.The aim of the study was to examine how the presence of humic substances (both aquatic and sedimentary) may affect iron bioavailability to the bloom-forming cyanobacterium Microcystis aeruginosa Kutzing incubated on standard and modified mineral BG-11 media. The final iron concentrations in the growth media ranged from 0.1 to 100mM.The results demonstrate that both the growth rate and the concentration of chlorophyll a in cultures of M. aeruginosa are limited by insufficient (a 15-fold as compared with the cultures exposed to iron only at the same concentration. Sedimentary humic acids in the presence of iron at a...

2007-01-01

189

Application of electrochemically dissolved iron in the removal of tannic acid from water  

British Library Electronic Table of Contents (United Kingdom)

Effects of some experimental parameters (supporting electrolyte, initial pH and current density) on the performance of electrocoagulation process using iron electrodes were investigated. Results of experiments showed that dissolution of iron is purely electrochemical and fits well with Faraday's law and leads to Fe^2^+ which are chemically oxidized into Fe^3^+ in aerated conditions. In neutral and alkaline conditions, the reaction between hydroxyl ions generated at the cathode and dissolved iron ions forms insoluble hydroxo-iron species. Potentiodynamic polarization tests showed that the formation of passive film on iron anode limits the continuous electrochemical dissolution of iron. Corrosion and pitting potentials largely depend on the nature of supporting electrolyte. The dissolution o...

2011-01-01

190

Superplastic forming behaviors and microstructure characters of magnesium alloy sheet AZ31B  

International Nuclear Information System (INIS)

An experimental study on superplastic forming behaviors and microstructure characters of commercial magnesium alloy sheet AZ31B is presented in this paper. The main experimental results show that the commercial magnesium alloy AZ31B sheet has superplastic capability. For the received sheet without any pre-processing, the maximum elongation is 295%. The dynamic recrystallization and grain refinement can be found, In the case of temperature =# 350 deg. C. The superplastic behaviors can be improved by controlling the dynamic recrystallization and grain refinement. Some experimental results of free superplastic bulging are presented in this paper. The results show that influence of temperature on forming capability is much less than the influences of temperature on elongation. In addition, the maximum principle strain.

2004-06-10

191

Microstructures and tensile properties of wrought magnesium alloys processed by ECAE  

Energy Technology Data Exchange (ETDEWEB)

Magnesium alloys are ideal candidates to benefit from equal channel angular extrusion (ECAE) because of their poor forming characteristics due to a hcp structure. In this study, ECAE processing was applied to ZK31 and AZ31 magnesium alloys under various conditions. The grain size of as-ECAE specimens decreases with decreasing the processing temperature, however, the grain size decreases slightly with increasing number of repetitive processing. Both the tensile strength and 0.2% proof stress of as-ECAE specimens are high when processed at low temperature, but the elongation is high when processed at high temperature. Crystal orientation is different in the two alloys and it also varies according to the processing temperature for the two alloys. The difference of the crystal orientation influences the tensile properties, especially 0.2% proof stress. (orig.)

2003-07-01

192

Materials and processing designs for high-performance magnesium alloys  

Energy Technology Data Exchange (ETDEWEB)

Materials and processing designs for advanced magnesium alloys with fine microstructures and superior properties were established by the combination of the repeated plastic working and the Mg{sub 2}Si synthesis in solid-state. The grain size was less than 1 {mu}m via RPW process due to its severe plastic working on raw powder. The hot extruded magnesium alloys produced in industries showed high ultimate tensile strength, e.g. 420{proportional_to}450 MPa, when employing Mg-Zn-Al-Ca-RE (Rare Earth) alloy coarse powder, having 0.5{proportional_to}2 mm diameter, as input materials. (orig.)

2005-07-01

193

Isothermal sheet formability and microstructure study of rolling processed magnesium alloy AZ31  

Energy Technology Data Exchange (ETDEWEB)

Applications of magnesium alloys are motivated mainly by their lightweight. However, manufacturing cost should also be evaluated when considering applying them. From this point of consideration, adoption of sheet forming processes, which previously have not been heavily researched, should be an option. This paper is intended to pioneer the study of the formability of magnesium alloy AZ31 out of rolled sheets at elevated temperatures. The rolled microstructures are examined and correlated with their formability. Post-forming conditions will also be investigated. The tool employed to perform the sheet forming experiments was a punchless die-setting which used pressurized gas to press the sheet into a female die cavity. This technique applied to Mg-alloy is unconventional and warrants attention for its potential utilization in the industry. (orig.)

2003-07-01

194

Hydrostatic extrusion of magnesium: process mechanics and performance  

Energy Technology Data Exchange (ETDEWEB)

Following the breakthrough for cast magnesium products, interest is now spreading to wrought applications - triggering a variety of technological questions. A major bottleneck in the manufacture of magnesium sections (profiles) by conventional hot extrusion is the low productivity, with extrusion speeds typically five to ten times lower than for comparable aluminium sections. This paper focuses on the use of hydrostatic extrusion as a means to overcome this problem. On the basis of an analytical model, it is clarified why and how process limits are affected by the process mechanics. Experimental work on the hydrostatic extrusion of the alloys M1A, ZM21 and AZ31 confirms that extrusion speed is indeed multiplied, whereas the resulting mechanical properties are similar to or better than those for conventional extrusions. (orig.)

2003-07-01

195

Fracture behavior under dynamic biaxial stress on magnesium alloy  

Energy Technology Data Exchange (ETDEWEB)

We conduct the static and dynamic loading fracture experiments on magnesium alloy (AZ31B) under the equitable and inequitable biaxial stress. We process specimens as cross type with cracks. There are different kinds of cracks defined by their crack angles. By using a hydraulic high-speed biaxial experiment machine, we put the equitable and inequitable stresses on the specimen. We analyze results using the caustic method. The experiments reveal a few important results. There is negative correlation between the fracture toughness value and the plate thickness in the magnesium alloy sheet specimen. The fracture toughness value decrease in the case the crack has the angle different from the loading direction. The fracture toughness value decreases significantly under the inequitable biaxial stress. (orig.)

2004-07-01

196

Anisotropic properties of magnesium sheet AZ31  

Energy Technology Data Exchange (ETDEWEB)

Car weight corresponds directly to fuel consumption and driving performance. So in order to improve the fuel efficiency and performance of a car the weight has to be reduced. Magnesium as a light metal offers a wide range of weight saving opportunities, especially Magnesium wrought alloys with their improved mechanical properties have a high potential for structural applications. Mechanical properties in terms of their quality and anisotropy are dependent on the microstructure of the material and can be characterized by their degree of inhomogeneity, their grain size distribution and their crystallographic texture. Therefore the orientation distribution of grains, the grain size, its size distribution, the chemical composition (precipitates) itself influence the mechanical parameters and their anisotropy. In this presentation first results of mechanical anisotropy are given: differences in yield stress, r-values and their relation to the ...

2003-07-01

197

Differential responses of the freshwater wetland species Juncus effusus L. and Caltha palustris L. to iron supply in sulfidic environments  

Energy Technology Data Exchange (ETDEWEB)

Sulfur pollution can lead to serious problems in freshwater wetlands, including phosphorus eutrophication and sulfide toxicity. We tested the effects of anaerobic iron-rich groundwater discharge in fens, simulated by iron injection, on two characteristic species (Juncus effusus and Caltha palustris) in a sulfidic environment. Biomass production of C. palustris roots showed an optimum response to the combined addition of iron and sulfide, with highest values at intermediate concentrations of both substances. Iron deficiency apparently occurred at low iron concentrations, while at high iron concentrations, growth was decreased. For J. effusus, in contrast, no toxic effects were found of both iron and sulfide. This could be explained by larger radial oxygen loss (ROL) of J. effusus and could not be explained by differences in phosphorous ...

2007-05-15

198

Iron catalyzed hydrogenation of high sulphur content coals  

Energy Technology Data Exchange (ETDEWEB)

Four high-sulphur low-rank coals have been treated at hydrogenation conditions with three iron-based catalyst precursors: Red Mud (Fe[sub 2]O[sub 3]), iron sulphide and iron pentacarbonyl. The obtained yields show a dependence with the sulphur content of the coals; the organic sulphur content correlates with the conversion and THF-solubles when Red Mud and iron sulphide are added. In spite of the high hydrogen sulphide partial pressure in the reaction, the addition of other sources of sulphur enhances the percentages in conversion products. 15 refs., 2 figs., 3 tabs.

1993-12-01

199

Method of treating final products from flue gas desulfurization  

Science.gov (United States)

A method of treating final products from a flue gas desulfurization. The flue gas desulfurization is carried out by the absorption of sulfur oxide in a spray dryer with a suspension which contains lime, or in a reactor with a dry, fine-grained, absorbent which contains lime. Prior to desulfurization, the fly ash carried along by the flue gas which is to be desulfurized is separated entirely, partially, or not at all from the flue gas, and the final products from the flue gas desulfurization, prior to any further treatment thereof, amount to 1-99% by weight, preferably 1-70% by weight, of fly ash, and 1-99% by weight, preferably 30-99% by weight, of the sum of the desulfurization products, preferably calcium sulfite hemihydrate, and/or calcium sulfite, and/or calcium sulfate dyhydrate, and/or calcium sulfate hemihydrate, and/or calcium sulfate, as well as residue of the absorbent. ...

1984-10-23

200

Synthesis and photoluminescence properties of Sm3+-doped LaMgB5O10 and GdMgB5O10  

International Nuclear Information System (INIS)

Luminescence and reflection spectra as well as luminescence kinetics of the 1 mol% Sm3+-doped crystalline lanthanum magnesium meta borate (LaMgB5O10) and gadolinium magnesium meta borate (GdMgB5O10) were analyzed. Materials were synthesized by conventional solid state route and showed bright orange-red emission under UV excitation. Emission spectra contain sharp and well resolved Sm3+4G5/2#->#6HJ transitions indicating a strong crystal-field effect. In case of gadolinium compound energy transfer between Gd3+ and Sm3+ was detected. The luminescent kinetics of the Sm3+ in analyzed powders is characterized by single exponential decay and experimental values vary in the range 2.2-2.4 ms. - Research highlights: ? Phosphorescence of samarium-doped lanthanide magnesium meta borates. ? Bright and well resolved orange-red emission of Sm3+ under UV excitation. ? Energy transfer from Gd3+ to Sm3+ in gadolinium ...

2011-07-01

201

Sol-gel coatings with phosphonate functionalities for surface modification of magnesium alloys  

International Nuclear Information System (INIS)

Hybrid organic-inorganic coatings with phosphonate functionalities have been synthesized and evaluated as prospective surface treatments for magnesium materials. These coatings have been processed via a sol-gel route by hydrolysis and condensation of a mixture of diethylphosphonatoethyltriethoxy-silane and tetraethoxy-silane with variable molar ratios. The coatings morphology and the surface chemistry at the coating/substrate interface have been characterized using scanning electron microscopy, X-ray photoelectron spectroscopy, "3"1P nuclear magnetic resonance spectroscopy, and time-of-flight secondary ion mass spectrometry. The corrosion protection performance of the coatings deposited on magnesium alloy AZ31B has been examined by a group of electrochemical techniques including potentiodynamic polarization and electrochemical impedance spectroscopy. In addition, a scanning Kelvin probe technique has been used to investigate interfacial ...

2006-08-30

202

Oxide growth on aluminium alloys in the presence of ammonium fluoborate  

Energy Technology Data Exchange (ETDEWEB)

The aim of this study as to determine the mechanisms involved in using ammonium fluoborate as a reducing atmosphere when preheating a high magnesium content aluminium alloy. Rutherford Backscattering (RBS) has been the major technique used in the analysis of samples, it revealed significant reduction in both the diffusion of magnesium to the surface and the calculated oxide thickness in the presence of NH{sub 4}BF{sub 4}. At temperatures above 500 deg C in air, SEM images revealed depressions and voids due to incipient melting at various stages, around the grain boundaries. Grain boundaries effectively acted as pipes aiding the diffusion of magnesium to the surface. These results have been verified through compositional analysis with both RBS and auger electron spectroscopy (AES). Results from NH{sub 4}BF{sub 4} atmosphere preheat conditions showed significant improvements. It was verified experimentally that above 500 deg ...

1996-12-31

203

Heterogeneous coupling of phenylethyne over Cu-Mg-Al mixed oxides. Influence of catalyst composition and calcination temperature on structural and catalytic properties  

Science.gov (United States)

The catalytic effects of copper-aluminium-magnesium oxides in the oxidative coupling of phenylethyne is described. The importance of surface properties as a redox site are discussed.

1997-07-01

204

Flow microfluorometric and spectrophotofluorometric analysis of DNA staining in mammalian cells  

Science.gov (United States)

The effects of various fixative agents, pH, ionic strength, stain concentration, and magnesium concentration on DNA staining with the antibiotics olivomycin, chromomycin A3, and mithramycin were examined with DNA in solution and in mammalian cells.

1977-01-01

205

Corrosion and histopathological studies on anode materials for implantable power sources. [In vivo corrosion studies on anode material  

Science.gov (United States)

The biocompatibility and corrosion resistance of various materials for use as sacrificial anodes in in vivo hybrid fuel cells were studied. Aluminium, zinc, and magnesium alloy AZ31B were studied, and the results are discussed.

1974-01-01

206

A mechanistic understanding of the formability of magnesium: examining the role of temperature on the deformation mechanisms  

Energy Technology Data Exchange (ETDEWEB)

The possibility of improving the cold formability of wrought magnesium alloys is considered in light of their good hot forming characteristics. Magnesium alloy AZ31B sheet is selected as a model system. Parameters affecting formability, such as strain hardening rate, strain rate sensitivity, and the degree of anisotropy are examined systematically by conducting tensile tests over a range of temperatures (room temperature to 250 C) and strain rates (1 x 10{sup -5} to 0.1 s{sup -1}). The plastic anisotropy and deformation texture evolution are examined in samples aligned with the sheet rolling and transverse directions. Polycrystal plasticity simulations using a viscoplastic self-consistent (VPSC) formulation are used to model the observed anisotropy and texture evolution. The adjustable parameters in the model are the relative critical resolved shear stresses of the dislocation mechanisms known to operate within magnesium. ...

2003-07-01

207

Wet limestone FGD solids analysis by thermogravimetry  

Energy Technology Data Exchange (ETDEWEB)

Wet limestone scrubbing is once again becoming a popular technology for removal of sulfur dioxide (SO{sub 2}) from power plant emissions. Critical to the operation of wet limestone flue gas desulfurization (FGD) systems is accurate chemical analysis of scrubber solids. The analytical technique of thermogravimetry is ideal for this application, as the instrument can give precise readings of the principal scrubber solids components, calcium sulfite/sulfate hemihydrate, calcium sulfate dihydrate (gypsum), and unused calcium carbonate. The data provides plant chemists, engineers, and operators with information needed to fine-tune scrubber operation and detect process upsets. (orig.)

2004-07-01

208

The effect of temperature and flow stress for climb-controlled dislocation creep in magnesium alloy  

Energy Technology Data Exchange (ETDEWEB)

Effect of strain rate, temperature and grain size in the climb-controlled dislocation creep region for AZ31 magnesium alloy was examined at lower temperature of {proportional_to}473 K. The flow stress was not affected by the difference in grain size. The strain rate sensitivity, m, was obtained 0.14 and 0.2 at low temperatures in high strain rate and at high temperature in low strain rate, respectively. It was found that the notion of effective diffusivity could express the dominant diffusion process during climb-controlled dislocation creep behavior uniquely. (orig.)

2003-07-01

209

Study of titanium-niobium alloys manufactured by magnesium thermic reduction of chlorides  

International Nuclear Information System (INIS)

Chemical and phase homogeneity of titanium-niobium sponge, produced by a combined magnesium-thermic reduction of niobium pentachloride and titanium tetrachloride mixtures, is investigated. It is ascertained that a sponge consists of spherical shape particles and has a large number of pores. Particle sizes are reduced with niobium being substituted for titanium from 50-500 #mu#m for titanium sponge to 1-40 #mu#m for niobium one, which testifies to the bormation in a titanium-niobium sponge of an alloy and not a mechanical mixture. A number of solid solutions is detected by X-ray phase analysis. Lattice parameters are determined.

210

Recrystallization during and following hot working of magnesium alloy AZ31  

Energy Technology Data Exchange (ETDEWEB)

The microstructures of magnesium AZ31 are examined following hot compression testing and annealing. The grain size, fraction dynamically recrystallized and, in a couple of cases, the crystallographic texture are reported. It was found that the progress of dynamic recrystallization is strongly sensitive to processing conditions but that the dynamically recrystallized grain size was less sensitive to stress than in other metals. It was also found that, for structures containing between 80 and 95% dynamic recrystallization, abnormal grain growth occurs during annealing. The crystallographic texture produced is also sensitive to the deformation conditions. (orig.)

2003-07-01

211

Microstructure, texture and mechanical properties of the magnesium alloy AZ31 processed by ECAP  

Energy Technology Data Exchange (ETDEWEB)

To investigate the influence of equal channel angular pressing on the microstructure and texture of the magnesium alloy AZ31, electron backscattering diffraction and well as neutron diffraction experiments were carried out. Through these experiments it was possible to trace the microstructure and texture evolution with strain accumulated with the increasing number of equal channel angular pressing passes. It was further demonstrated by subsequent compression tests that the microstructural changes produced by equal channel angular pressing have a beneficial effect on both the compressive strength and ductility of AZ31. (orig.)

2008-01-15

212

Hot workability, microstructural control and rate-controlling mechanisms in cast-homogenized AZ31 magnesium alloy  

Energy Technology Data Exchange (ETDEWEB)

Optimum conditions for microstructural control in industrial hot working of cast and homogenized AZ31 magnesium alloys are evaluated by using a processing map. The recommended window for bulk metal working of this alloy is the domain in the temperature range 300-450 C and strain rate range 1-10 s{sup -1}, and the optimum processing parameters are 400 C and 10 s{sup -1}, where grain-boundary self diffusion is the rate-controlling mechanism. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

2009-03-15

213

Effect of mineralizer on the nitridation of sialon-bonded silicon carbide products  

International Nuclear Information System (INIS)

The effect of a mineralizer, magnesium silicate, on the nitridation of compacts consisting of silicon, clay, silica and silicon carbide was examined in terms of their reaction depth, density, porosity, phase composition and microstructure. It was found that addition of mineralizer slowed down the nitridation significantly. The kinetic process of isothermal nitridation in the presence of magnesium silicate obeys a parabolic rate law. Otherwise it obeys a linear rate law. The results suggest that nitrogen transportation is the limiting step during nitridation when mineralizer is added. The mechanism of nitridation is discussed in terms of phase composition and microstructure. Copyright (2000) The Australian Ceramic Society

214

Diffusion bonding on superplastic-aluminum and -magnesium alloys  

Energy Technology Data Exchange (ETDEWEB)

The superplastic characteristics and diffusion bonding behaviors were investigated in commercial 7475 aluminum alloy and AZ31 magnesium alloy sheets. In this study, the presently used materials behaved in a superplastic manner at {proportional_to} 773 K (7475Al) and {proportional_to} 523 K (AZ31). Then, by the theoretical relationship between pressure and time, these materials were successfully diffusion bonded at the superplastic temperatures. The bonding strength was more than 65 MPa. The experimental bonding conditions in high quality joining, times and pressures, were good agreed with prediction analysis. (orig.)

2004-07-01

215

Vitamin D and respiratory health  

UK PubMed Central (United Kingdom)

Vitamin D is now known to be of physiological importance outside of bone health and calcium homeostasis, and there is mounting evidence that it plays a beneficial role in the prevention and/or treatment...Full Text Available

2009-10-01

216

Two-photon calcium imaging from head-fixed Drosophila during optomotor walking behavior  

British Library Electronic Table of Contents (United Kingdom)

Drosophila melanogaster is a model organism rich in genetic tools to manipulate and identify neural circuits involved in specific behaviors. Here we present a technique for two-photon calcium imaging in the central brain of head-fixed Drosophila walking on an air-supported ball. The ball's motion is tracked at high resolution and can be treated as a proxy for the fly's own movements. We used the genetically encoded calcium sensor, GCaMP3.0, to record from important elements of the motion-processing pathway, the horizontal-system lobula plate tangential cells (LPTCs) in the fly optic lobe. We presented motion stimuli to the tethered fly and found that calcium transients in horizontal-system neurons correlated with robust optomotor behavior during walking. Our technique allows both behavior ...

2010-01-01

217

Transformation of Verapamil by Cunninghamella blakesleeana  

UK PubMed Central (United Kingdom)

A filamentous fungus, Cunninghamella blakesleeana AS 3.153, was used as a microbial model of mammalian metabolism to transform verapamil, a calcium channel antagonist. The metabolites...Full Text Available

2004-05-01

219

Role of temperature in the spontaneous precipitation of calcium sulfate dihydrate  

Energy Technology Data Exchange (ETDEWEB)

The spontaneous precipitation of calcium sulfate in supersaturated solutions over the temperature range between 25.0 and 80.0 C was investigated by monitoring the solution specific conductivity during desupersaturation. From measurements of the induction times preceding the onset of precipitation the surface energy of the forming solid, identified as gypsum, was found between ca. 12 and 25 mJ/m{sup 2} for the temperature range between 80.0 and 25.0 C, respectively. Kinetics analysis showed that over 50 C it is possible that anhydrous calcium sulfate is forming as a transient phase converting into the more stable calcium sulfate dihydrate. The linear dependence of the rates of precipitation on the relative solution supersaturation suggested a mechanism according to which the growth units are integrated into the active sites of the supercritical nuclei by surface diffusion. According to the morphological examination of the ...

1999-02-16

220

Mechanisms of Reproductive Thermotolerance in Gossypium hirsutum: The Effect of Genotype and Exogenous Calcium Application  

British Library Electronic Table of Contents (United Kingdom)

Abstract Although photosynthetic thermotolerance has been investigated extensively in cotton leaves, reports on the biochemical influence of the pistil in promoting fertilization thermostability are limited. To evaluate the effect of temperature, genotype, and exogenous calcium application on fertilization and pistil biochemistry in cotton, thermosensitive (cv. ST4554 B2RF) and thermotolerant (cv. VH260) plants were grown under control (30/20-C) or high-temperature (38/20-C) conditions during flowering, and exogenous CaCl2 was applied to flowers 1-day prior to anthesis. Measured pistil parameters included fertilization efficiency; protein concentration; glutathione reductase, superoxide dismutase (SOD) and NADPH oxidase activities; and ATP and calcium levels. Exogenous calcium had no effec...

2011-01-01

221

Loss of Skeletal Calcium by Patients on Maintenance Dialysis  

UK PubMed Central (United Kingdom)

Direct radiological measurements of the mineral content of femoral bone were performed in 13 patients on maintenance dialysis. They were found to be sufficiently sensitive to be used for monitoring,...Full Text Available

1970-08-29

222

Instrumental-activation analysis of Mo, Al, Ca, Mn, Cl, Na, and K in soil-plant samples  

International Nuclear Information System (INIS)

... activation analysis aluminium 28 calcium 49 chlorine 38 cotton plants li-drifted

223

Effects of manganese doping on properties of sol-gel derived biphasic calcium phosphate ceramics  

British Library Electronic Table of Contents (United Kingdom)

We have investigated the effect of manganese (Mn) doping on properties of nanosized biphasic calcium phosphate powders and their dense bodies. Manganese levels of 0.6, 1.3, 1.9, 4.3, 7.0 and 11.9at.% were successfully incorporated into biphasic calcium phosphate via a sol-gel route. The prepared powders were calcined at temperatures of 500-1200^oC. The X-ray diffraction analysis revealed that a mix phase comprising of hydroxyapatite and @b-tricalcium phosphate were present, however the content of each phases in the structure was affected by the Mn content. The studies found that the largest portion of @b-tricalcium phosphate was detected at 4.3at.% Mn doping. The incorporation of Mn has also greatly increased the crystallinity of the biphasic calcium phosphate powder due to progressive den...

2011-01-01

224

Noninvasive analysis of skin iron and zinc levels in beta-thalassemia major and intermedia  

Energy Technology Data Exchange (ETDEWEB)

Diagnostic x-ray spectrometry, a method based on x-ray fluorescence analysis, was used for noninvasive determination of iron and zinc in two distinct skin areas, representing predominantly dermal and epidermal tissues, in 56 patients with beta-thalassemia major and intermedia. The mean iron levels in the skin of patients with beta-thalassemia major and intermedia were elevated by greater than 200% and greater than 50%, respectively, compared with control values. The zinc levels of both skin areas examined were within the normal range. The data indicate that the rate and number of blood transfusions, which correlated well with serum ferritin levels (r . 0.8), are not the only factors that determine the amount of iron deposition in the skin (r less than 0.6). Other sources of iron intake contribute to the total iron load in the tissues, particularly in patients who are not given ...

1985-01-01

225

Feasibility study of iron mineral separation from red mud by high gradient superconducting magnetic separation  

International Nuclear Information System (INIS)

Research highlights: #-># Red mud residues (RM) were disposed in alumina production. #-># Utilization of Red mud residues was affected by its iron content. #-># Superconducting magnetic separation (HGSMS) was used in iron separation from RM. #-># RM with high and low iron contents were separated in HGSMS. - Abstract: The disposal of bayer red mud tailings now seriously threats the environment safety. Reduction and recycling of red mud is now an urgent work in aluminum industry. High gradient superconducting magnetic separation (HGSMS) system was applied to separate the extreme fine RM particles (<100 #mu#m) into high iron content part and low iron content part. Two sorts of RM were fed in the HGSMS. The iron oxide contents in concentrates were about 65% and 45% when RM 1 and RM 2 were fed respectively. Meanwhile, the residues contained 52.0% or ...

2011-02-01

226

Neutron and gamma-ray penetrations in thick iron  

Energy Technology Data Exchange (ETDEWEB)

Measurements of neutron and gamma-ray penetrations in an iron shield were performed up to a 60-cm depth in a tightly coupled source shield configuration with the fast-neutron reactor YAYOI as a source. Rates of neutron reactions and gamma-ray dose rates in the iron shield were obtained using activation foils and thermoluminescent dosimeters. Analyses of the experiments were made by using the DOT-III code with coupled neutron and gamma-ray cross sections from ENDF/B-IV and POPOP4 libraries. To obtain the source condition for the iron shield analyses, the calculated spectrum was adjusted to the measured reaction rates at the reactor shield boundary. The calculated neutron and gamma-ray distributions in the iron shield show fairly good agreement with the experiments. The effect of difference in Bondarenko-type self-shielding factors on the analyses of the iron shield is also shown.

1980-03-01

227

Chemically bonded phosphate ceramics : part III : reduction mechanism and its application to iron phosphate ceramics.  

Energy Technology Data Exchange (ETDEWEB)

In this, the last of a series of three papers, we discuss a method of forming iron phosphate ceramics by a reduction process. We report the formation of iron oxide ceramics by reducing hematite with iron in a phosphoric acid solution. The reaction results in a rapid-setting ceramic (at room temperature) with a compressive strength of 3700 psi and a density of 1.7 g/cm{sup 3}. Although the exact mineral form of the binder is difficult to determine because it is mostly amorphous and hence is not amenable to X-ray diffraction analyses, this material is expected to consist of iron hydrophosphates. The reduction process is very useful in recycling several industrial wastes that are rich in hematite, including iron mine tailings, red mud (a caustic waste from the alumina industry), and machining swarfs. Formation of ceramics with red mud and swarfs is also discussed.

2003-11-01

228

The effects of a calcium deficient diet on the mechanical properties and morphology of goose bone.  

Science.gov (United States)

A control group of geese (Anser anser) on a normal calcium diet for egg laying poultry was compared to egg laying geese on a calcium deficient diet. The ultimate compressive strength and modulus of elasticity of femoral cortical bone from each group were determined by compressing right circular cylinders which were 2.4 mm in height and 0.8 mm in diameter. The bending strength and bending modulus of elasticity of tibial cortical bone were determined by three point bend tests on rectangular prisms which were approximately 25 mm by 0.8 mm by 0.8 mm. Bone calcium content and eggshell calcium content were determined by atomic absorption spectrophotometry. Blood samples were analyzed for free calcium ion concentration. Histological observations included studies of cross-sectional microradiographs, examinations of cross sections stained by a modified Masson's technique, and a determination ...

1986-01-01

229

Isotope aided studies of the bioavailability of iron and zinc from human diets consumed in Venezuela  

International Nuclear Information System (INIS)

Previous studies on Venezuelan diets provided information on food consumed in each diet and their nutritional contents. It also showed the comparison of the iron absorption from these diets when given in the morning after over-night fast and when given at the customary time of the day. It was observed that the iron absorption from the lunch given at noon was slightly higher (although not significant) in Zulia and Sucre diets. There were no significant differences between the Zulia lunch given in the morning after over-night fast at noon. Similar results were observed in the Sucre diet lunch repeated twice. From these results we can state that iron absorption from meals is not affected by the time it is administered with the condition that the subjects tested have had a previous fast of three hours before the meal is administered. The significant difference in iron absorption in the first study could be ...

1992-11-16

230

Selective Expression in Carotid Body Type I Cells of a Single Splice Variant of the Large Conductance Calcium- and Voltage-activated Potassium Channel Confers Regulation by AMP-activated Protein Kinase*  

UK PubMed Central (United Kingdom)

Inhibition of large conductance calcium-activated potassium (BKCa) channels mediates, in part, oxygen sensing by carotid body type I cells. However, BKCa channels remain active...Full Text Available

2011-04-08

231

Physicochemical basis for formation of renal stones of calcium phosphate origin: calculation of the degree of saturation of urine with respect to brushite  

UK PubMed Central (United Kingdom)

Brushite (CaHPO4·2H2O) was considered to govern the formation of renal calculus of calcium phosphate origin. The degree of saturation of urine with respect to this phase...Full Text Available

1969-10-01

232

Effects of xylitol on the absorption of /sup 203/Pb in mice and cockerels  

Energy Technology Data Exchange (ETDEWEB)

Earlier studies have indicated that xylitol may increase the absorption and urinary excretion of dietary oxalate. It has also been indicated that xylitol increases the absorption of calcium. Intestinal absorption of lead, a divalent contaminant in the diet, is in many respects similar to that of calcium. The purpose of this study was to evaluate the effects of xylitol on the intestinal absorption of lead using two different approaches: the in situ ligated intestinal loop technique in cockerels and gastric gavage in mice.

1986-07-01

233

TMPRSS6 rs855791 modulates hepcidin transcription in vitro and serum hepcidin levels in normal individuals.  

Science.gov (United States)

The iron hormone hepcidin is inhibited by matriptase-2, a liver serine-protease encoded by TMPRSS6 gene. Cleaving the BMP-coreceptor hemojuvelin, matriptase-2 impairs the BMP/SMAD signaling pathway, downregulates hepcidin and facilitates iron absorption. TMPRSS6 inactivation causes iron-deficiency-anemia refractory to iron administration both in humans and mice. Genome wide association studies have shown that the SNP rs855791, which causes the matriptase-2 V736A amino acid substitution, is associated with variations of serum iron, transferrin saturation, hemoglobin and erythrocyte traits. Here we show that in vitro matriptase-2 736(A) inhibits hepcidin more efficiently than 736(V). Moreover, in a genotyped population, after exclusion of samples with iron deficiency and inflammation, hepcidin, hepcidin/transferrin saturation and hepcidin/ferritin ratios were ...

2011-08-26

234

Synthesis and characterization of PVP-coated large core iron oxide nanoparticles as an MRI contrast agent  

UK PubMed Central (United Kingdom)

The purpose of this study was to synthesize biocompatible polyvinylpyrrolidone (PVP)-coated iron oxide (PVP-IO) nanoparticles and to evaluate their efficacy as a magnetic resonance imaging (MRI)...Full Text Available

2008-04-01

235

Stable isotope studies on iron bio-availability in young Indian women: Effects of nutritional status, interactions and ethnicity  

International Nuclear Information System (INIS)

Iron is an essential micronutrient. As an integral part of hemoglobin, it is essential for the transport of oxygen in blood to the tissues. It is an important component of cytochromes and other tissue enzymes that are critical for cellular respiration and of myoglobin that helps maintain oxygen reserve in the muscle. It is also involved in the normal functioning of the immune function, and in the synthesis of steroid hormones and bile acids. There are serious functional consequences to iron deficiency and iron deficiency anemia (IDA) in the human body. The deleterious effects include increased morbidity, preterm delivery, low birth weight, delayed cognitive development, lowered cellular immunity and reduced physical work capacity. However, iron deficiency and IDA remain the world's most common deficiency disease in the 21st century. Recent estimates of people affected with iron ...

2002-06-24

236

Serum Prohepcidin Levels in Helicobacter Pylori Infected Patients with Iron Deficiency Anemia  

UK PubMed Central (United Kingdom)

Background/AimsHelicobacter pylori (H. pylori) infection appears to subvert the human iron regulatory mechanism and thus upregulates hepcidin, resulting...Full Text Available

2010-06-01

237

Oxidation of phosphine by iron(III) chloride complexes supported on activated charcoal  

Energy Technology Data Exchange (ETDEWEB)

It has been discovered that iron(III) chloride complexes supported on activated charcoal oxidize phosphine under normal conditions. The process accelerates as the concentration of the chloride ions and the proton acid increases.

1988-06-01

238

Isotope - aided studies of the bioavailability of iron and zinc from human diets consumed in Poland  

International Nuclear Information System (INIS)

The main aims of the study were: 1) the evaluation of iron and zinc status in women of Lodz aged 18-45 years, 2) adaptation of the whole body counter to in vivo measurements absorption of iron given to the gastro-intestinal tract of volunteers and 3) in rat model estimation iron bioavailability from fortified wheat flour combined with products usually consumed in Poland. During five months investigations thirty seven women were examined each one twice in two months interval. Following variables were measured: iron and zinc in blood serum, in public and scalp hair and in food, taste acuity score, serum ferritin, hemoglobin, total iron binding capacity, red blood cells, mean corpuscular concentration and corpuscular volume. Prevalence of iron deficiency and iron deficient anemia were assessed by two models in terms of the depression of serum ...

239

Iron Overload, Hematopoietic Cell Transplantation, and Graft-versus-Host Disease  

UK PubMed Central (United Kingdom)

Many patients who undergo hematopoietic cell transplantation (HCT) present with anemia and have received red blood cell transfusions before HCT. As a result, iron overload is frequent and appears...Full Text Available

2009-10-01

240

Impact of the 3,6,9-Trioxadecyloxy Group on Desazadesferrithiocin Analogue Iron Clearance and Organ Distribution  

UK PubMed Central (United Kingdom)

The impact of introducing a 3,6,9-trioxadecyloxyl group at various positions of the desazadesferrithiocin (DADFT) aromatic ring on iron clearance and organ distribution is described. Three DADFT...Full Text Available

2007-07-12

241

Gallium Disrupts Iron Uptake by Intracellular and Extracellular Francisella Strains and Exhibits Therapeutic Efficacy in a Murine Pulmonary Infection Model ?  

UK PubMed Central (United Kingdom)

Francisella tularensis requires iron (Fe) for growth, but the biologic sources of Fe for this organism are largely unknown. We found that Francisella sp. growing in...Full Text Available

2010-01-01

242

Equation of state of laser-shocked compressed iron; Equation d'etat du fer comprime par choc laser  

Energy Technology Data Exchange (ETDEWEB)

This thesis enters the field of highly compressed materials equation of state studies. In particular, it focuses on the case of laser shock compressed iron. This work indeed aims at getting to the conditions of the earth's core, comprising a solid inner core and a liquid outer core. The understanding of phenomena governing the core's thermodynamics and the geodynamic process requires the knowledge of iron melting line locus around the solid-liquid interface at 3.3 Mbar. Several experiments were performed to that extent. First, an absolute measurement of iron Hugoniot was obtained. Following is a study of partially released states of iron into a window material: lithium fluoride (LiF). This configuration enables direct access to compressed iron optical properties such as reflectivity and self-emission. Interface velocity measurement is dominated by compressed LiF ...

2004-01-01

243

Effectiveness of zinc protoporphyrin/heme ratio for screening iron deficiency in preschool-aged children  

UK PubMed Central (United Kingdom)

Hemoglobin and zinc protoporphyrin (ZPP) tests are commonly used to screen for iron deficiency, but little research has been done to systematically evaluate the sensitivity and specificity of these...Full Text Available

2011-02-01

244

Consequences of Low Neonatal Iron Status due to Maternal Diabetes Mellitus on Explicit Memory Performance in Childhood  

UK PubMed Central (United Kingdom)

Diabetic pregnancies are characterized by chronic metabolic insults, including iron deficiency, that place the developing brain at risk and for memory impairment later in life. A behavioral...Full Text Available

2009-11-01

245

Clinical evaluation of serum ferritin to iron ratio in malignant diseases  

Energy Technology Data Exchange (ETDEWEB)

Serum ferritin levels were measured in 72 normal subjects and in 214 cases with various diseases by an immunoradiometric assay. In normal subjects, the serum ferritin levels were 27-230 ng/ml. Elevated serum ferritins were observed in most cases with iron excess and acute hepatitis. Markedly elevated levels were found in the majority of cases with acute leukemia, malignant lymphoma, hepatoma, and pancreatic cancer. High ferritin levels were also found in other malignant diseases. However, the range overlapped broadly with that of nonmalignant diseases. The serum ferritin correlated significantly with serum iron in normals and in those with iron deficiency anemia. In most nonmalignant cases, the serum ferritin and iron levels distributed on a regression line obtained from levels in normals and those with iron deficiency anemia. However, 92% of the malignant cases showed a serum ...

1981-07-01

246

Biosynthesis and Uptake of Siderophores Is Controlled by the PacC-Mediated Ambient-pH Regulatory System in Aspergillus nidulans  

UK PubMed Central (United Kingdom)

Biosynthesis and uptake of siderophores in Aspergillus nidulans are regulated not only by iron availability but also by ambient pH: expression of this high-affinity iron uptake system...Full Text Available

2004-04-01

247

Solid-gas equilibria in CaSO/sub 3/-H/sub 2/O/sub (g)/ system and Lewis-acid-base alloys  

Energy Technology Data Exchange (ETDEWEB)

The role played by calcium sulfite in the flue gas desulfurization of lime/limestone scrubbers makes it desirable to work out its thermodynamic properties. A thermogravimetric apparatus was used to study the equilibria between calcium sulfite hemihydrate and calcium sulfite anhydrite under different conditions. Efforts were made to analyze the difficulties encountered in the dynamic approach to equilibration after calcium sulfate dihydrate failed in calibration of the apparatus. Finally, the kinetics and thermodynamics for the dissociation of calcium sulfite hemihydrate were examined. The confirmation of Engel-Brewer's correlation between the electronic configuration and crystal structure in metallic systems has long been pursued in this group by studying the Lewis-acid-base interactions. Tantalum-iridium alloys of different compositions were brought into equilibrium with ...

1981-10-01

248

Human complement protein C99 is a calcium binding protein  

International Nuclear Information System (INIS)

Human complement protein C9 is shown to be a metalloprotein that binds 1 mol of Ca"2"+/mol of C9 with a dissociation constant of 3 #mu#m as measured by equilibrium dialysis. Incubation with EDTA removes the bound calcium, resulting in a apoprotein with decreased thermal stability. This loss in stability leads to aggregation and, therefore, to loss of hemolytic activity upon heating to a few degrees above the physiological temperature. Heat-induced aggregation of apoC9 can be prevented by salts that stabilize proteins according to the Hofmeister series of lyotropic ions, suggesting that the ion in native C9 may ligand with more than one structural element of domain of the protein. Ligand blotting indicates that the calcium binding site is located in the amino-terminal half of the protein. Removal of calcium by inclusion of EDTA in assay mixtures has no effect on the hemolytic activity of C9, and its capacity to bind to C8 in ...

250

Kinetics of reduction of iron oxides using microwaves as power source  

Energy Technology Data Exchange (ETDEWEB)

This work deals with kinetic description of carbothermic reduction of iron oxides using microwaves as power source. Previous researches show that it is possible to conduct this kind of process successfully, but real kinetic comparisons between conventional and microwaves procedure have been presented partially. The aim of this work is to describe reduction kinetics, taking into account how the iron oxide is reduced by microwaves compared with conventional energy supply. In this study the authors used iron ore in pellet shape and dust. They found that both, pellet and dust reduction stops when it reaches approximately 40%, even at whole power.

1996-12-31

252

Ductile aluminide alloys for high temperature applications  

Energy Technology Data Exchange (ETDEWEB)

Alloys are described which contain nickel, aluminum, boron, iron and in some instances manganese, niobium and titanium.

1987-01-01

254

Anaerobic oxidation of carbon steel in granitic groundwaters: A review of the relevant literature  

International Nuclear Information System (INIS)

This report reviews the published literature on the anaerobic oxidation of iron in aqueous solutions which are of particular relevance to Swedish granitic groundwaters. The thermodynamics of iron corrosion in water are briefly considered. Following this the experimental data found in the literature are presented and discussed. Results were found for corrosion of iron in both pure water and solutions containing mineral salts. The literature work in the nature of the films formed on iron surfaces under anaerobic conditions is reviewed and the possible mechanisms of film formation are discussed. Conclusions are drawn on the factors most likely to influence and control film growth. 32 refs.

2010-02-01

255

Thin Wall Iron Castings  

Energy Technology Data Exchange (ETDEWEB)

Results of an investigation made to develop methods of making iron castings having wall thicknesses as small as 2.5 mm in green sand molds are presented. It was found that thin wall ductile and compacted graphite iron castings can be made and have properties consistent with heavier castings. Green sand molding variables that affect casting dimensions were also identified.

2001-10-31

256

Isotope aided studies of the bioavailability of iron from human diets consumed in Peru  

International Nuclear Information System (INIS)

Iron deficiency anaemia is an important health problem in Peru, which affects approximately 25% of the population. The most vulnerable groups are children below 5 years of age and pregnant women, of whom 64% and 53% respectively are anemic. The main reason for this deficiency is inadequate iron intake. Heme iron consumption is very low, and non-heme iron is virtually the only source of iron in the diet. Despite regional differences in food consumption, wheat, salt and sugar are widely consumed in all areas. Wheat is likely to be the most suitable food vehicle for iron fortification due to the processing required. Based on the recent food consumption surveys conducted in Lima by the IIN, we selected examples of typical main meals and measured iron bioavailability in the diet using an extrinsic tag method with 1.5 #mu#Ci of "5"9Fe and 5 #mu#Ci ...

1992-11-16

257

Formation of iron oxides during mechanical activation in water  

International Nuclear Information System (INIS)

It has been shown that mechanical milling of iron in water results in formation of nanocrystalline magnetite Fe3O4 with an average particle size of 0.6 ?m, saturation magnetization of 77 Am2/kg and coercivity of ?150 A/cm. Along with magnetite, an antiferromagnetic Fe-O phase (?10 wt%), which is an aggregate of small iron-oxygen clusters forms.

2007-05-21

258

Effect of the most common spices and herbs in typical northwestern Thai diet on human iron absorption. Highlights and achievements  

International Nuclear Information System (INIS)

Iron deficiency anaemia is highly prevalent among rural population of Northeast Thailand. The habitual diets are plant-based. Several herbal vegetables and spices such as lead tree leaves, ivy gourd, Thai basil, chilli peppers etc are consumed in a substantial in common Northeast dishes. High contents of phytate and polyphenol compounds including tannin in these herbs and spices may profoundly influence iron bioavailability in the northeast population

2002-06-24

259

The surface chemistry of iron Fischer-Tropsch catalysts  

Energy Technology Data Exchange (ETDEWEB)

The indirect conversion of coal to liquid hydrocarbons via steam gasification followed by synthesis gas (CO/H/sub 2/) chemistry has been the subject of intensive study for a number of decades. A key technological challenge facing researchers in this area is control over the product distribution during the hydrocarbon synthesis step. In the case of iron Fischer-Tropsch catalysts, it has been known that the addition of alkali to the metal catalyst has a significant impact on the product distribution. Iron catalysts treated with alkali produce less methane more alkenes and higher molecular weight products. In spite of numerous investigations, the details of this promotional effect are not understood on a molecular level. To explore the role of alkali in the surface chemistry of iron catalysts, the authors have carried out a combined surface science and catalytic kinetic study of a model iron catalyst with ...

1986-04-01

260

Scuffing behavior of gray iron and 1080 steel in reciprocating and rotational sliding  

British Library Electronic Table of Contents (United Kingdom)

Scuffing damage is catastrophic and typically not self-healing. It severely affects the life and reliability of engineering components, such as cams, roller bearings, piston rings, cylinder bores and gears. Gray iron and 1080 steel are important materials for these extremely demanding structural components. There have been several scuffing studies done in the past with various types of steel and cast iron. However, in these studies there was no attempt to compare the scuffing resistance of cast iron and steel materials with similar matrices. In the present study, scuffing tests were performed with the matrices of gray iron and 1080 steel being fully pearlitic. This allows for a direct evaluation of the effect of the graphite flakes on scuffing resistance. The scuffing behavior for these ma...

2011-01-01

261

Manufacturing of oxide-dispersion-strengthened steels with the use of preliminary surface oxidation  

British Library Electronic Table of Contents (United Kingdom)

Regularities of deformation-induced dissolution of a surface layer of iron oxides in matrixes of iron-based alloys with bcc and fcc lattices have been studied by the methods of M?ssbauer spectroscopy, transmission electron microscopy, and X-ray diffraction. A method of producing iron alloys strengthened by dispersed oxide nanoparticles and alloyed with elements possessing a high affinity to oxygen (titanium and yttrium) has been proposed, which implies a dynamic dissolution of a surface layer of iron oxides upon strong cold deformation and a precipitation of secondary yttrium and titanium nanooxides upon a subsequent high-temperature sintering of mechanically alloyed powders. There has been demonstrated a possibility of oxide strengthening of pure iron upon its interaction with air without...

2011-01-01

262

Cancer-cell-specific cytotoxicity of non-oxidized iron elements in iron core-gold shell NPs  

British Library Electronic Table of Contents (United Kingdom)

Gold-coated iron nanoparticles (NPs) selectively and significantly (P <0.0001) inhibit proliferation of oral- and colorectal-cancer cells in vitro at doses as low as 5 mg/mL, but have little adverse effect on normal healthy control cells. The particle treatment caused delay in cell-cycle progression, especially in the S-phase. There was no significant difference in the NP uptake between cancer and control cells, and cytotoxicity resulted primarily from the iron core, before oxidation, rather than from the Fe ions released from the core. In contrast with magnetic NPs that usually serve as drug carriers, diagnostic probes or hyperthermia media, the iron, before oxidation, in the NPs selectively suppressed cancer cell growth and left healthy control cells unaffected in vitro and in vivo. This...

2011-01-01

263

Small-molecule screen identifies inhibitors of a human intestinal calcium-activated chloride channel.  

Science.gov (United States)

Calcium-activated chloride channels (CaCCs) are widely expressed in mammalian tissues, including intestinal epithelia, where they facilitate fluid secretion. Potent, selective CaCC inhibitors have not been available. We established a high-throughput screen for identification of inhibitors of a human intestinal CaCC based on inhibition of ATP/carbachol-stimulated iodide influx in HT-29 cells after lentiviral infection with the yellow fluorescent halide-sensing protein YFP-H148Q/I152L. Screening of 50,000 diverse, drug-like compounds yielded six classes of putative CaCC inhibitors, two of which, 3-acyl-2-aminothiophenes and 5-aryl-2-aminothiazoles, inhibited by >95% iodide influx in HT-29 cells in response to multiple calcium-elevating agonists, including thapsigargin, without inhibition of calcium elevation, calcium-calmodulin kinase II activation, or cystic fibrosis transmembrane conductance ...

2007-12-14

264

Molecular mechanisms of the epithelial transport of toxic metal ions, particularly mercury, cadmium, lead, arsenic, zinc, and copper. Progress report, January 1, 1979-December 31, 1979  

International Nuclear Information System (INIS)

The mechanism of lead transport is presented, and especially the particular similarities or dissimilarities between lead and calcium in this process. The absorption of these metals was determined cockerels, raised on a commercial diet or on a specified diet, using in vivo ligated loop procedure. The dose administered into the loop contained 0.5 #mu#Ci "2"0"3Pb (and/or 0.1 #mu#Ci "4"7Ca), and 0.01 mM lead acetate (and/or mM CaCl_2) in 0.5 ml 0.15 M NaCl,pH 6.5. It was shown that lead is rapidly taken up by the mucosal tissue, and slowly transferred into the body, whereas less calcium is retained by the tissue and the transfer of calcium is many times as effective as that for lead. They appear to respond in a similar manner to a low calcium intake and vitamin D treatment. Increasing luminal stable lead concentration significantly reduced the percentage of radiolead significantly reduced the percentage of ...

265

The reduction of feedwater iron by using absorption characteristics of cation exchange resins for BWR condensate demineralizers  

International Nuclear Information System (INIS)

Iron concentration control in feedwater is one of the most important subjects in water chemistry. Especially for the BWR plants without 100% flow volume of hollow fiber filter (HFF), rather high iron concentration in feedwater is one of the big issues as this causes relatively high radiation dose rate in drywell area. Cation exchange resins especially used in the plants with partial flow rate of HFF are expected to have the important role of capturing iron in feedwater. For this purpose, we have investigated the effective method for using iron absorption characteristics of cation exchange resin. The Cation-Over Layer method (COL) in condensate demineralizers (CD) effectively utilizes these characteristics. In order to demonstrate a performance of the cation overlay method, we had applied this method for three CD vessels at Fukushima Daiichi NPP Unit 3 for testing purpose. The result of this actual plant ...

2009-10-01

266

In vitro corrosion, cytotoxicity and hemocompatibility of bulk nanocrystalline pure iron  

International Nuclear Information System (INIS)

Bulk nanocrystalline pure iron rods were fabricated by the equal channel angular pressure (ECAP) technique up to eight passes. The microstructure and grain size distribution, natural immersion and electrochemical corrosion in simulated body fluid, cellular responses and hemocompatibility were investigated in this study. The results indicate that nanocrystalline pure iron after severe plastic deformation (SPD) would sustain durable span duration and exhibit much stronger corrosion resistance than that of the microcrystalline pure iron. The interaction of different cell lines reveals that the nanocrystalline pure iron stimulates better proliferation of fibroblast cells and preferable promotion of endothelialization, while inhibits effectively the viability of vascular smooth muscle cells (VSMCs). The burst of red cells and adhesion of the platelets were also substantially suppressed on contact with the ...

2010-12-01

267

The phospholipid vesicles coating on metal chelated inorganic surfaces  

International Nuclear Information System (INIS)

This work showed the formation of phospholipid vesicle coating on inorganic sericite surface with characterization by combining electron microscopy of FE-SEM, TEM, AFM, and qualitatively evaluated the coated phospholipid vesicle by XPS as a function of etching time. The possibility of phospholipid vesicle mobility on the surface was restrained by the chelation effect of magnesium cation. The stabilization properties of phospholipid vesicles on sericite surface were demonstrated by the various concentration of magnesium cation. The presence of magnesium was found to have a much more pronounced influence on the lipid deposition process. The Mg cation plays an important role for attaching the phospholipids with optimum concentration of 7 mM. Totally, the phospholipid vesicles coating on inorganic powder could be useful for bio-related fields such as cosmetics and drug delivery system as the key functional compounds. We hope ...

2007-09-01

268

Rapidly solidified AZ31 magnesium alloy ribbons used in rechargeable batteries  

Energy Technology Data Exchange (ETDEWEB)

Better properties of magnesium make it a natural choice for use as an anode material in rechargeable batteries. However, the magnesium alloy thin sheets used in rechargeable batteries were produced by ingot casting and rolling. That technology was so complex and the cost was high. Rapidly solidification by melt spinning is an effect way to solve that problem. In this paper, the technology of rapidly solidified (RS) ribbons in Mg-3%Al-1%Zn-0.2%Mn alloy has been investigated using melt spinning technique. The effect of wheel speed on thickness and microhardness of the ribbons is presented. Microhardness is found to increase with the wheel speed. Rapidly solidification leads to small grains (1{proportional_to}2 {mu}m). The plasticity of the ribbons was well. The quantity of Mg{sub 17}Al{sub 12} decreases with the increase in wheel speed. When the wheel speed reaches 1600 rpm, no Mg{sub 17}Al{sub 12} phase precipitates. As the increase of the wheel ...

2005-07-01

269

Particle size effects on the desorption properties of nanostructured magnesium dihydride (MgH2) synthesized by controlled reactive mechanical milling (CRMM)  

International Nuclear Information System (INIS)

In the present work the hydrogen desorption properties of nanostructured magnesium hydride (MgH2) synthesized by controlled reactive mechanical milling (CRMM) of elemental Mg powder under hydrogen are investigated. A profound effect of the particle size of synthesized MgH2 hydride on its hydrogen desorption characteristics measured by differential scanning calorimetery (DSC) has been found. All synthesized MgH2 powders are characterized by a double hydrogen desorption peak. Furthermore, below a certain threshold particle size the DSC desorption temperature of the peak doublet starts decreasing rapidly with decreasing of the mean hydride powder particle size (expressed as equivalent circle diameter-ECD). In contrast, the nanograin (crystallite) size of MgH2 does not seem to have apparent effect on the DSC desorption temperature. It is also observed that for powder particles smaller than some threshold value, X-ray diffraction shows the presence of two polymorphic ...

2006-11-09

270

Mushy state forming of magnesium alloy making use of resistance heating  

Energy Technology Data Exchange (ETDEWEB)

Feasibility of mushy state forming of magnesium alloys making use of resistance heating was examined. Magnesium alloys, AZ31, AZ61 and AZ91, were taken up as experimental materials and cylindrical billets with a diameter of 15 mm and a height of 20 mm were used for both resistance heating and forming experiments. Input heat control was applied to the billet heating and insertion of thin discs of austenitic stainless steel with a low thermal conductivity between the billet and copper electrodes was attempted in order to improve the efficiency of the billet heating. Results were summarized as follows. (1) Resistance heating by input heat control was successful to heat the billets to their respective mushy state. (2) Insertion of the discs was very helpful in heating the billets and realized the heating in a couple of seconds. (3) The force applied to the electrodes to ensure the electrical contacts being too small, sparks occurred and welds arose ...

2003-07-01

271

In situ ellipsometric studies of formation kinetics of rare earth metal conversion coatings on magnesium alloy  

International Nuclear Information System (INIS)

In situ spectroscopic ellipsometry was employed to investigate the initial regime of rare earth metal (REM) conversion coatings formation on AZ31 magnesium alloy. Three REM salts solutions, 0.05 mol.dm"-"3 Ce(NO_3)_3, La(NO)_3 and Sm(NO)_3 solutions, were used for REM conversion coatings preparation. By deconvoluting the ellipsometric data, the surface of the fresh well-polished AZ31 magnesium alloy was found to be covered with 15.80 nm thick native (hydr)oxide film; the refractive indices and the thickness of Ce, La and Sm conversion coatings were obtained. The formation kinetics of three REM coatings follows different exponential functions and the coatings exhibit different optical properties. La conversion coating has the largest n values and the lowest k values while Sm conversion coating is just opposite. Moreover, the pH variation of the bulk conversion solutions upon the coatings formation was recorded. It is confirmed that the reduction ...

2008-05-01

272

Impact of elevated CO{sub 2} and nitrogen fertilization on foliar elemental composition in a short rotation poplar plantation  

Energy Technology Data Exchange (ETDEWEB)

The experiment was carried out on a short rotation coppice culture of poplars (POP-EUROFACE, Central Italy), growing in a free air carbon dioxide enriched atmosphere (FACE). The specific objective of this work was to study whether elevated CO{sub 2} and fertilization (two CO{sub 2} treatments, elevated CO{sub 2} and control, two N fertilization treatments, fertilized and unfertilized), as well as the interaction between treatments caused an unbalanced nutritional status of leaves in three poplar species (P. x euramericana, P. nigra and P. alba). Finally, we discuss the ecological implications of a possible change in foliar nutrients concentration. CO{sub 2} enrichment reduced foliar nitrogen and increased the concentration of magnesium; whereas nitrogen fertilization had opposite effects on leaf nitrogen and magnesium concentrations. Moreover, the interaction between elevated CO{sub 2} and N fertilization amplified some element unbalances such ...

2007-06-15

273

Evaluation of press formability in magnesium alloy  

Energy Technology Data Exchange (ETDEWEB)

A press formability of magnesium alloy sheet cannot be evaluated by only general characteristics in tensile test; tensile strength, elongation n-value and r-value. For example, AZ31-alloy elongates about 20% in room temperature but breaks easily at shallow stage in deep drawing, which is caused by little local elongation (local necking). Crystallographic restriction of slip deformation in this alloy produces high strength, which almost equal to macroscopic fracture strength. In press forming, the bending under high tension requires a large deformability. A great difference in the deformability between AZ31 magnesium alloy and a strain hardened A1100 Aluminum (only 5% in elongation) is shown by static bending test with V-notch. In a rolled plate of AZ31, a crack is produced by stress concentration and propagates with reduced load at all testing temperature up to 453 K. In contrast, the point of notch in A1100 is dulled by local plastic ...

2003-07-01

274

Thermal stability of mixed-cation #alpha#-sialon ceramics  

International Nuclear Information System (INIS)

A series of #alpha#-sialon (#alpha#') compositions containing mixed stabilising cations were prepared, by introducing additional CaO to a basic Sm #alpha#-sialon compositions. The thermal stability of these Sm-Ca-containing #alpha#-sialon phases was investigated using XRD, SEM and EDXS techniques. It was found that the addition of calcium into the Sm #alpha#-sialon systems greatly improved the stability of the #alpha#-sialon phases. Calcium was found to be incorporated into the #alpha#-sialon structure, coexistent with the samarium, and partitioning of the calcium and samarium was observed between the #alpha#' phase and grain boundary phases. This indicates a technique which may be used to improve the thermal stability of the #alpha#' phase while maintaining good refractory phases at the sialon grain boundaries.

2003-01-02

275

Spermatozoa of Sharpsnout sea bream (Diplodus puntazzo) and European sea bass (Dicentrarchus labrax) express opioid receptors  

British Library Electronic Table of Contents (United Kingdom)

Endogenous opioid peptides (EOP) are molecules affecting many biological functions influencing productive and reproductive performance. They increase in stress conditions and interact with specific opioidergic receptors (OR): delta, kappa and mu. Several studies in other animal species suggest that they can also affect sperm cell motility. In fish the ionic external environment modulates the increase of intracellular calcium ion that is required to activate sperm motility after spawning. In mammals OR are functionally associated to calcium channels and in fishes calcium is highly required for fish sperm activation. In this study the presence of OR on spermatozoa of two Perciform fish, the sharpsnout seabream (Diplodus puntazzo, family Sparidae) and the European sea bass (Dicentrarchus labr...

2010-01-01

276

Separation of lithium and calcium isotopes during chemical isotopic exchange in extraction systems with phosphoryl-containing podands  

International Nuclear Information System (INIS)

A study was made on extraction of a series of lithium and calcium salts by monopodands L with common formula R-C_6H_4-O-(CH_2CH_2O)_n-C_6H_4-R, where R - CH_2P(O)Ph_2, n 1-3. Extraction-chromatographic separation of lithium and calcium isotopes in systems of metal aquacomplex-solvatocomplex with L in organic phase was conducted. It was established that separation coefficients of "6Li/"7Li isotopes ranged between 1.003 #+-#0.001 and 1.017 #+-#0.002 at the maximal separation degree equal to 1.60. Separation of "4"0Ca/"4"4Ca isotopes was not fixed. 12 refs., 4 figs., 1 tab.

277

Process for producing calcium sulfate dihydrate during desulfurization of stack gases from power station boilers. Verfahren zur Herstellung von Calciumsulfat-Dihydrat im Zuge der Entschwefelung von Rauchgasen aus Kraftwerkskesselfeuerungen  

Energy Technology Data Exchange (ETDEWEB)

This is a process for producing calcium sulfate dihydrate during desulfurization of stack gases from power station boilers, where the stack gases are introduced into a washing tower and are treated with a washing water suspension containing lime in the washing tower, where oxygen in the form of air or of air enriched in oxygen is also blown into the washing tower, and where the washing water suspension drawn off from the washing tower is fed back to the washing tower at a temperature of 45 to 50/sup 0/C in the circuit and at least part of the flow goes via a thickener and where calcium sulfate dihydrate slurry is drawn off from the thickener.

1986-06-12

278

Nanoscale calcium bismuth mixed oxide with enhanced photocatalytic performance under visible light  

British Library Electronic Table of Contents (United Kingdom)

The objective of materials research is the development of economical, safe and efficient synthesis routes that lead to the formation of a photocatalyst which is able to overcome performance problems related to particle size, crystallinity, or low surface area. Here, we report high-quality functional nanoparticles of calcium bismuth mixed oxide with 15nm nominal size corresponding to a specific surface area of 41m^2/g which were produced by single-step flame spray synthesis (FSS). The high temperature of the flame afforded creation of oxygen vacancies which were quantified by near edge X-ray absorption fine structure (NEXAFS) spectra. These two parameters, developed active surface area and created in the flame oxygen vacancies, allowed to enhance the photocatalytic activity of calcium bismu...

2010-01-01

279

Luminescence properties of thallium crystal phosphors and their use in determining microgram quantities of thallium  

Energy Technology Data Exchange (ETDEWEB)

The preparation and luminescence properties of crystal phosphors based on alkali metal iodide and calcium oxide substrates were studied. The highest luminescence intensities were achieved with iodide substrates at 200/sup 0/ and with the calcium oxide substrate at 800/sup 0/. The calibration graphs were linear in the thallium concentration ranges 0.03-5.0 and 0.1-2.0 mu g using sodium and potassium oxides, respectively, and in the range 0.05-5 mu g using cesium iodide and calcium oxide. A method is proposed for the determination of down to 3 x 10/sup -4/% thallium in rocks, using a crystal phosphor with sodium iodide substrate.

1986-02-01

280

Depression of calcium pump activity in renal cortex of vitamin D-deficient rats with secondary hyperparathyroidism  

Energy Technology Data Exchange (ETDEWEB)

To examine the hormonal regulation of the ATP-dependent Ca{sup 2+} pump in the kidneys, the ATP-dependent Ca{sup 2+} uptake by the basolateral membrane vesicles in the renal cortex was measured using radioactive calcium ({sup 45}Ca{sup 2+}) in rats with vitamin D deficiency or rats undergoing thyroparathyroidectomy. The V{sub max} of the Ca{sup 2+} pump activity was increased not only by administering calcitriol, but also by normalizing the serum calcium level in vitamin D-deficient rats. PTH suppressed the Ca{sup 2+} pump activity in normocalcemic vitamin D-deficient rats. Thyroparathyroidectomy did not affect the Ca{sup 2+} pump activity in the kidneys of normal rats. It was concluded that the ATP-dependent Ca{sup 2+} pump activity was depressed by secondary hyperparathyroidism in vitamin D-deficient rats. (author).

1990-01-01

281

Depression of calcium pump activity in renal cortex of vitamin D-deficient rats with secondary hyperparathyroidism  

International Nuclear Information System (INIS)

To examine the hormonal regulation of the ATP-dependent Ca"2"+ pump in the kidneys, the ATP-dependent Ca"2"+ uptake by the basolateral membrane vesicles in the renal cortex was measured using radioactive calcium ("4"5Ca"2"+) in rats with vitamin D deficiency or rats undergoing thyroparathyroidectomy. The V_m_a_x of the Ca"2"+ pump activity was increased not only by administering calcitriol, but also by normalizing the serum calcium level in vitamin D-deficient rats. PTH suppressed the Ca"2"+ pump activity in normocalcemic vitamin D-deficient rats. Thyroparathyroidectomy did not affect the Ca"2"+ pump activity in the kidneys of normal rats. It was concluded that the ATP-dependent Ca"2"+ pump activity was depressed by secondary hyperparathyroidism in vitamin D-deficient rats. (author).

282

Chemistry of strontium  

International Nuclear Information System (INIS)

This paper describes stable strontium as composed of four stable isotopes ( Sr 88, Sr 87, Sr 86, and Sr 84), of which Sr 88 contributes more than 82% to its composition. Strontium exists in three crystalline, plymorphic forms; face-centered cubic alpha form, hexagonal beta form and body-centered cubic gamma form. Strontium occupies in many physicochemical aspects an intermediate position between calcium and barium, as does the solubility of strontium salts. As a result of its oxidation potential, strontium readily forms oxides, halides, and sulfide. The author proposes that the slight discrimination against strontium incorporation into bony tissues may be due to the difference in ionic potential (14%) between strontium and calcium. Ionic potential is an indicator of the strength of ionic bonds: strontium has a smaller ratio of ionic charge to ionic radius when compared with calcium.

283

The diffusion bonding and theoretical model including void growth mechanism in magnesium alloys  

Energy Technology Data Exchange (ETDEWEB)

There are many factors affecting diffusion bonding in order to obtain high quality joining. Therefore, in the beginning, we constructed diffusion bonding model based on void growth mechanism to predict bonding pressures and times. In addition, in order to compare theoretical values with experimental values, diffusion bonding tests were carried out by using commercial AZ31 magnesium alloy sheets with different grain sizes, 16 and 130 {mu}m. The present AZ31 alloys were successfully diffusion bonded at several conditions, and the bonding strength was more than 0.8 of each parent materials. The experimental bonding conditions in high quality joining, times and pressures, were good agreed with prediction analysis. (orig.)

2003-07-01

284

Study on the interface of PVDF coatings and HF-treated AZ31 magnesium alloy: Determination of interfacial interactions and reactions with self-healing properties  

International Nuclear Information System (INIS)

Research highlights: ? Reports a high protection system for the alloy in corrosive environment. ? Describes an interfacial process with self-healing properties. ? Reports the influence of substrate pre-treatment in the coating performance. - Abstract: In this paper the interface of poly(vinylidene fluoride) coatings prepared by the dip coating method and HF-treated AZ31 magnesium alloy was evaluated. The best performance of this system in corrosion tests compared to ground, as-received and acetic acid cleaned substrates is related to an acid-base interaction at the interface and to interfacial reactions which resulted in a self-healing process. The protectiveness of the samples was investigated using impedance and immersion tests while the coating morphology and interface stability were investigated by scanning electron microscopy, X-ray photoelectron spectroscopy and adhesion tests.

2011-02-01

285

Sodium monocarboxylates as inhibitors of AZ31 alloy corrosion in a synthetic cooling water  

Energy Technology Data Exchange (ETDEWEB)

This research investigated the inhibiting effects that sodium salts of linear monocarboxylic acids displayed towards the corrosion process of AZ31 Mg alloy in ASTM D 1387 saline solution (a synthetic industrial cooling water). The length of the aliphatic chain of the acids ranged between 7 and 15 carbon atoms. The inhibiting action of these salts can be related to the precipitation of an insoluble magnesium salt, which mainly affected the anodic reaction. The aliphatic chain length controlled the anion solubility and the reaction rate of magnesium carboxylate formation. For all the salts, an optimum concentration was experienced: 10{sup -2} M for sodium decanoate (caprate), 10{sup -3} M for sodium dodecanoate (laurate), 10{sup -4} M for sodium tetradecanoate (myristate); when this concentration was exceeded, a diminution (even a disappearance) in the inhibiting action was found. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

2009-03-15

286

Microstructures of friction welded joints of AZ31 to AM60 magnesium alloys  

Energy Technology Data Exchange (ETDEWEB)

AZ31 magnesium alloy was friction-welded to AM60 and the microstructures and the friction welding process were studied. The microstructures changed near the weld interface. The AZ31 was refined to a grain size of several {mu}m near the weld interface. The nucleation occurred in the shear bands that were introduced during the welding process. On the other hand, the eutectic structure was deformed and the lamellar structure which was composed of {alpha}-Mg and Mg{sub 17}Al{sub 12} was formed near the weld interface in AM60 alloy. In the friction process, the adhesion and peel off occurred alternately between AZ31 and AM60. Eventually, bonding was completed during upset process. (orig.)

2003-07-01

287

Ion-radiation hardening of magnesium oxide crystals  

International Nuclear Information System (INIS)

Consideration is given to the data, demonstrating the effect of ion radiation on strength characteristics of ionic crystals, presented by magnesium oxide. Crystals, prepared in the form of plates, were irradiated by Si"+, Fe"+, C"+ ions by the dose of 10"1"6-10"1"7 ion/cm"2 at room temperature in vacuum. The following characteristics were investigated: dislocation density, microhardness, crack resistance. Investigation of dislocation structure showed, that dislocation density in irradiated sample was 2-3 times higher, as compared to nonirradiated one. Sufficient increase of fracture viscosity of MgO crystals was revealed. It can be conditioned by occurrence of compression stresses in the surface layer, decelerating crack formation and propagation.

288

Internal strain and texture evolution during deformation twinning in magnesium  

Energy Technology Data Exchange (ETDEWEB)

The development of a twinned microstructure in hexagonal close-packed rolled magnesium compressed in the in-plane direction has been monitored in situ with neutron diffraction. The continuous conversion of the parent to daughter microstructure is tracked through the variation of diffraction peak intensities corresponding to each. Approximately 80% of the parent microstructure twins by 8% compression. Elastic lattice strain measurements indicate that the stress in the newly formed twins (daughters) is relaxed relative to the stress field in the surrounding matrix. However, since the daughters are in a plastically 'hard' deformation orientation, they quickly accumulate elastic strain as surrounding grains deform plastically. Polycrystal modeling of the deformation process provides insight about the crystallographic deformation mechanism involved.

2005-06-15

289

Initial grain size effect of dynamic recrystallization of magnesium alloy AZ31  

Energy Technology Data Exchange (ETDEWEB)

Dynamic development of new grain boundaries was studied in compression of a magnesium alloy AZ31 with initial grain sizes (D{sub 0}) of 22 {mu}m and 90 {mu}m at a temperature of 673 K. Kink bands are evolved near corrugated grain boundaries and in grain interiors at low strains accompanied with new fine grains. Kink bands are developed often perpendicular to the basal plane. The boundary misorientation of kink band as well as the volume fraction of new grains increases rapidly with increasing strain and approaches a saturation value in high strain. New fine grains are developed faster with decrease in the D{sub 0}. It is concluded that new grain evolution is controlled by a deformation-induced continuous reaction, i.e. continuous dynamic recrystallization (DRX). (orig.)

2003-07-01

290

Grain refinement on AZ31 magnesium alloy by highly strained and annealed method  

Energy Technology Data Exchange (ETDEWEB)

Grain refinement in AZ31 magnesium alloy has been attempted by hot-rolling and annealing process. Specimens were solution heat treated at 673 K for 36 ks, then hot-rolled at 423-773 K with total reduction of 20-80% by multi pass process. The rolled specimens were annealed at 473-673 K for 3.6 ks. Grain sizes after the solution heat treatment were about 20 to 150 {mu}m. After hot-rolling at 573 K and annealing at 473 K, grain sizes decreased into about 5 to 10 {mu}m. Suppression of grain growth by pinning due to precipitates was observed by transmission electron microscopic observations. (orig.)

2004-07-01

291

Zero-valent iron and iron oxide-coated sand as a combination for removal of co-present chromate and arsenate from groundwater with humic acid  

International Nuclear Information System (INIS)

The combination of zero-valent iron (Fe0) and iron oxide-coated sand (IOCS) was used to remove Cr(VI) and As(V) from groundwater in this study. The efficiency and the removal mechanism of Cr(VI) and As(V) by using this combination, with the influence of humic acid (HA), were investigated using batch experiments. Results showed that, compared to using Fe0 or IOCS alone, the Fe0-IOCS can perform better on the removal of both Cr(VI) and As(V). Metal extraction studies showed that As(V) was mainly removed by IOCS and iron corrosion products while Cr(VI) was mainly removed by Fe0 and its corrosion products. Competition was found between Cr(VI) and As(V) for the adsorption sites on the iron corrosion products. HA had shown insignificant effects on Cr(VI) removal but some effects on As(V) removal kinetics. As(V) was adsorbed on IOCS at the earlier stage, but adsorbed/coprecipitated with the ...

2011-02-01

292

Noninvasive assessment of skin iron content in hemodialysis patients. An index of parenchymal tissue iron content  

Energy Technology Data Exchange (ETDEWEB)

Iron overload has been described in patients undergoing chronic hemodialysis. The present study was undertaken to evaluate a rapid, noninvasive method for determination of skin iron by the technique of diagnostic x-ray spectrometry (DXS). Thirty-five patients receiving chronic hemodialysis treatment entered the study and were compared with 25 normal controls. Since pathological skin iron deposition occurs mainly at the dermal-epidermal junction in the basal cells of the epidermis, measurements were made in the thenar eminence representing mainly epidermal tissue (FeE), and in the forearm representative mainly of dermis (FeD). The mean +/- SD FeE iron concentrations were equivalent to 14.5 +/- 8.8 and 18.2 +/- 10.2 parts per million wet weight tissue (ppm) and both were significantly higher than in normal controls in which they averaged 9.2 +/- 2.5 ppm (P less than 0.005) and 10.2 +/- 3.2 ppm (P less ...

1988-07-01

293

Kinetic, spectroscopic and chemical modification study of iron release from transferrin; iron(III) complexation to adenosine triphosphate  

Energy Technology Data Exchange (ETDEWEB)

Amino acids other than those that serve as ligands have been found to influence the chemical properties of transferrin iron. The catalytic ability of pyrophosphate to mediate transferrin iron release to a terminal acceptor is largely quenched by modification non-liganded histine groups on the protein. The first order rate constants of iron release for several partially histidine modified protein samples were measured. A statistical method was employed to establish that one non-liganded histidine per metal binding domain was responsible for the reduction in rate constant. These results imply that the iron mediated chelator, pyrophosphate, binds directly to a histidine residue on the protein during the iron release process. EPR spectroscopic results are consistent with this interpretation. Kinetic and amino acid sequence studies of ovotransferrin and lactoferrin, in addition to human ...

1985-01-01

294

Ellipsometric and XPS analysis of surface films on iron formed in methanol solutions; Methanol yoekichu de keiseisareta tetsu no hyomen himaku no eripsometori oyobi X sen kodenshi  

Energy Technology Data Exchange (ETDEWEB)

Surface films on iron formed in methanol solutions containing various amounts of water with or without 0.1 kmol/m{sup 3} LiClO4 have been analyzed by in-situ ellipsometry and ex-situ XPS. It was found that surface films having refractive indices n2 and absorption coefficients k2 in the range of 1.8-2.2 and 0.25-0.3, respectively, are formed on iron at potentials of the passive state. The values of n2 and k2 for passive films on iron obtained in the methanol are smaller than those of passive films formed in aqueous solutions. The refractive index n2 of the surface film on iron in the methanol became larger with increasing water or dissolved oxygen content. In the deaerated methanol with the water content less than 0.07%, a surface film having a refractive index of 1.7 was formed on iron, and XPS spectrum of this film showed a spectrum which was similar to that obtained from ...

1995-08-20

295

Efficacy and safety of total dose infusion of low molecular weight iron dextran in the treatment of iron deficiency anemia during pregnancy  

International Nuclear Information System (INIS)

To determine the efficacy and safety of Total Dose Infusion (TDI) of low molecular weight iron dextran for the treatment of iron deficiency anemia compared to oral iron replacement during pregnancy through improvement in hemoglobin (Hb) after intervention. Non-randomized control trial. A group of 100 pregnant women with gestational age greater than 12 weeks with confirmed diagnosis of iron deficiency anemia attending the antenatal clinics were enrolled in this study. Total dose iron infusion of low molecular iron dextran was given to these patients after calculating iron deficit, in a monitored in-patient setting. Control comprised of a second group of 50 pregnant females matched for age, parity and baseline hemoglobin, tolerant to oral iron supplementation (ferrous sulphate 200 mg three times a day) attending the ...

2008-07-01

296

Zinc release from thapsigargin/IP3-sensitive stores in cultured cortical neurons  

UK PubMed Central (United Kingdom)

BackgroundChanges in ionic concentration have a fundamental effect on numerous physiological processes. For example, IP3-gated thapsigargin sensitive intracellular calcium...Full Text Available

297

Vectors containing a prokaryotic dihydrofolate reductase gene transform Drosophila cells to methotrexate-resistance.  

UK PubMed Central (United Kingdom)

Transformed Drosophila Kc cell lines, resistant to methotrexate, an inhibitor of de novo purine and pyrimidine synthesis, have been obtained by calcium phosphate transfection of plasmids containing...Full Text Available

1983-01-01

298

The opening of the two pores of the Hv1 voltage-gated proton channel is tuned by cooperativity  

UK PubMed Central (United Kingdom)

SUMMARYIn voltage-gated sodium, potassium, and calcium channels the functions of ion conduction and voltage sensing are performed by two distinct structural units: the pore domain...Full Text Available

2010-01-01

299

The nucleation kinetics of calcium sulfate dihydrate in NaCl solutions up to 6 m and 90 C  

Energy Technology Data Exchange (ETDEWEB)

The crystallization of calcium sulfate from aqueous solutions with NaCl is both geological and industrial interest because NaCl is the dominant solute in natural brines and many industrial fluids. Induction periods for the nucleation of calcium sulfate dihydrate were experimentally determined as a function of supersaturation in NaCl solutions from 0 to 6 m at 25 C and in 3.0-m NaCl solutions at temperatures from 25 to 90 C. Using classic nucleation theory, the interfacial tension between gypsum and 3.0-m NaCl solution was estimated to be about 39 mJ/m[sup 2] at 25 C and increases with increasing temperature (to 63 mJ/m[sup 2] at 90 C). It was observed that the induction period decreases with increasing NaCl concentrations up to 3 m and then starts to increase slightly at a given temperature and saturation state. The electrolyte effect on nucleation was proportional to the enhanced solubility of calcium sulfate dihydrate in ...

1994-02-01

300

The L-type calcium channel inhibitor diltiazem prevents cardiomyopathy in a mouse model  

UK PubMed Central (United Kingdom)

Dominant mutations in sarcomere protein genes cause hypertrophic cardiomyopathy, an inherited human disorder with increased ventricular wall thickness, myocyte hypertrophy, and disarray. To understand...Full Text Available

2002-04-15

301

Studies on Inhibition of Intestinal Absorption of Radioactive Strontium  

UK PubMed Central (United Kingdom)

A method is reported which permits selective suppression of absorption of radioactive strontium from ingested food material, permitting the calcium to be available to the body. Studies were carried...Full Text Available

1964-08-08

302

Strength and fluoride release characteristics of a calcium fluoride based dental nanocomposite  

UK PubMed Central (United Kingdom)

Secondary caries and restoration fracture remain the two most common problems in restorative dentistry. Release of fluoride ions (F) could be a substantial benefit because F could enrich neighboring...Full Text Available

2008-11-01

303

Severe Hypocalcemia due to Vitamin D Deficiency after Extended Roux-en-Y Gastric Bypass  

UK PubMed Central (United Kingdom)

Vitamin D deficiency is a well-known comorbidity of obesity that can be exacerbated after bariatric surgery and can predispose the patient for hypocalcemia. Vitamin D and calcium doses to prevent and...Full Text Available

2011-01-01

304

Role of Calcium in Serine Transport into Tobacco Cells  

UK PubMed Central (United Kingdom)

The transport of serine into tobacco (Nicotiana tabacum L. var. Xanthi) cells grown in liquid medium was studied. Serine transport was maximal below pH 4.0. A time-dependent stimulation...Full Text Available

1978-12-01

305

Resistance of Bacillus subtilis var. niger Spores Occluded in Water-insoluble Crystals to Three Sterilization Agents  

UK PubMed Central (United Kingdom)

The resistance to destruction of spores of Bacillus subtilis var. niger occluded in crystals of calcium carbonate and exposed to ethylene oxide and moist and dry heat...Full Text Available

1967-07-01

306

Regulation of Vacuolar H+-Pyrophosphatase by Free Calcium 1  

UK PubMed Central (United Kingdom)

The H+-translocating inorganic pyrophosphatase (H+-PPase) associated with vesicles of the vacuolar membrane (tonoplast) isolated from beet (Beta vulgaris L.) is...Full Text Available

1992-12-01

307

Regulation of Calcium Influx in Chara1  

UK PubMed Central (United Kingdom)

Measurements were made of 45Ca influx into isolated internodal cells of Chara corallina and also into internodal cells of intact plants. 45Ca influx was closely...Full Text Available

1992-10-01

308

Rapid Action of Estrogens on Intracellular Calcium Oscillations in Primate Luteinizing Hormone-Releasing Hormone-1 Neurons  

UK PubMed Central (United Kingdom)

Feedback controls of estrogen in LHRH-1 neurons play a pivotal role in reproductive function. However, the mechanism of estrogen action in LHRH-1 neurons is still unclear. In the present study, the...Full Text Available

2008-03-01

309

Propagation of an alkaline wave with a short contact time through an argilite sample from the Meuse-Haute Marne underground laboratory; Propagation d'une onde alcaline a temps de contact court a travers un echantillon d'argilite de l'est  

Energy Technology Data Exchange (ETDEWEB)

In the framework of the feasibility study of radioactive waste disposal in deep geologic formations, a clay formation (named 'argilite de l'Est') has been selected in the Meuse-Haute Marne region (France) for the construction of an underground laboratory. The percolation of alkaline solutions through the argilite has been studied using column experiments with short residence times (30 min). These experiments simulate the leaching of a cement which could be used in the building materials of the laboratory. The alkaline solutions used are mono-cationic solutions of calcium, sodium and strontium. The behaviour of calcium is differentiated from the other cations. For all alkaline solutions (NaOH, Ca(OH){sub 2} or Sr(OH){sub 2}) chemical reactions consuming both hydroxide ions and their associated cations have been evidenced. These reactions are heterogenous reactions of surface adsorption by site ionization. The ...

2001-07-01

310

Process for the removal of sulfur oxides from exhaust gases using slurry of red mud containing calcium ion  

Energy Technology Data Exchange (ETDEWEB)

A process is given for the removal of sulfur oxides from exhaust gases by absorbing with a slurry of red mud containing calcium ion which comprises the steps of: (1) contacting an exhaust gas containing sulfur oxides of not higher than about 100/sup 0/ C with a slurry of red mud containing calcium ion led from the next step (2) to take up sulfur oxides in the gas until ph of the slurry becomes in the range of 4.3 to less than 6 while maintaining the molar fraction of SO/sub 4/-- to total SO/sub 2/ in the slurry within the said pH range at 0.05 to 0.7; and then, (2) contacting the treated gas with a fresh slurry of red mud containing calcium ion to further take up sulfur oxides in the gas while maintaining the concentration of NaHSO/sub 3/ in the slurry at not more than about 8 g/l.

1980-09-16

311

Physiological calcium concentrations regulate calmodulin binding and catalysis of adenylyl cyclase exotoxins  

UK PubMed Central (United Kingdom)

Edema factor (EF) and CyaA are calmodulin (CaM)-activated adenylyl cyclase exotoxins involved in the pathogenesis of anthrax and whooping cough, respectively. Using spectroscopic, enzyme kinetic and...Full Text Available

2002-12-16

312

Neurobehavioral effects of power-frequency electromagnetic fields.  

UK PubMed Central (United Kingdom)

Some laboratory experiments have suggested that power-frequency electric and magnetic fields (EMF) may be capable of influencing calcium efflux from cell membranes, pineal function, and circadian rhythms....Full Text Available

1993-12-01

313

Intra- and extracellular calcium modulates stereocilia stiffness on chick cochlear hair cells.  

UK PubMed Central (United Kingdom)

Segments of the chick basilar papilla were isolated and maintained in culture medium. The sensory hair bundle of individual hair cells was observed with light microscopy and stimulated with a water...Full Text Available

1994-02-01

314

Imaging of calcium transients in skeletal muscle fibers.  

UK PubMed Central (United Kingdom)

Epifluorescence images of Ca2+ transients elicited by electrical stimulation of single skeletal muscle fibers were studied with fast imaging techniques that take advantage of the large fluorescence...Full Text Available

1991-01-01

315

Hysteretic Behavior of Proprotein Convertase 1/3 (PC1/3)  

UK PubMed Central (United Kingdom)

The proprotein convertases (PCs) are calcium-dependent proteases responsible for processing precursor proteins into their active forms in eukariotes. The PC1/3 is a pivotal enzyme of this family that...Full Text Available

316

Hydrogenolysis reaction of deashed coal loaded K and Ca. K to Ca wo tanjishita dakkai sekitan no suisoka bunkai tokusei  

Energy Technology Data Exchange (ETDEWEB)

Taiheiyo coal deashed using acid treatment and loaded with potassium or calcium was hydro-cracked under gaseous phase to discuss effects of these metals on liquefaction reaction. In addition, the loaded coal was added with red mud catalyst to examine effects of the addition. The loaded potassium has a softening power, and particularly the potassium adsorbed into surface and micropores in the coal decomposes selectively HI-BS and BI-PS and generates gas and HS. On the other hand, potassium deposited on coal surface promotes direct gas production from the coal. Irrespective of its loading modes, calcium has a catalytic nature to produce HI-BS selectively. Calcium also acts to impede decomposition of HI-BS into HS. Adding red mud catalyst to potassium loaded coal increases the inversion rate and the liquefaction yield, and most of the increase is accounted for by HI -BS, and BI-PS. When red mud catalyst is added to ...

1992-11-05

317

Gynura procumbens Merr. decreases blood pressure in rats by vasodilatation via inhibition of calcium channels  

UK PubMed Central (United Kingdom)

INTRODUCTION:Gynura procumbens has been shown to decrease blood pressure via inhibition of the angiotensin‐converting enzyme. However, other mechanisms that...Full Text Available

2011-01-01

318

Effects of Prolonged High Phosphorus Diet on Phosphorus and Calcium Balance in Rats  

UK PubMed Central (United Kingdom)

The amount of phosphorus contained in food as food additives is currently increasing and a high intake of phosphorus can cause various diseases. To determine the effects of a prolonged high phosphorus...Full Text Available

2007-05-01

319

Effect of Anionic Salt and Highly Fermentable Carbohydrate Supplementations on Urine pH and on Experimentally Induced Hypocalcaemia in Cows  

UK PubMed Central (United Kingdom)

The objective of this experiment was to determine the effect of dietary grain on calcium homeostasis. Six rumen-fistulated dairy cows with 3 or more previous lactations and no history of parturient...Full Text Available

2004-01-01

320

Disulfide Bonds and the Quaternary Structure of Factor VIII/von Willebrand Factor  

UK PubMed Central (United Kingdom)

Human Factor VIII/von Willebrand factor, purified by calcium citrate-cellulose chromatography and 4% agarose gel filtration was subjected to sodium dodecyl sulfate gel electrophoresis on gels containing...Full Text Available

1978-09-01

321

Cytoplasmic Calcium Increases in Response to Changes in the Gravity Vector in Hypocotyls and Petioles of Arabidopsis Seedlings1  

UK PubMed Central (United Kingdom)

Plants respond to a large variety of environmental signals, including changes in the gravity vector (gravistimulation). In Arabidopsis (Arabidopsis thaliana) seedlings, gravistimulation...Full Text Available

2008-02-01

322

Citrat og nyresten  

DEFF Research Database (Denmark)

Citrate is an important naturally occurring inhibitor of calcium stone formation in urine. Urinary citrate excretion was examined in 43 consecutive patients with recurrent idiopathic calcium nephrolithiasis and in 50 normal controls by a specific enzymatic technique. Hypocitraturia (<1.6 mmol/24h) was found in 14 (33%) stone formers compared to 6 (12%) normal controls (p = 0.03). Citrate excretion expressed as citrate-creatinine ratio in 24 hour urine samples was significantly lower in the stone formers than in the healthy controls (p = 0.03), and significantly lower in healthy men, compared to healthy females (p = 0.006). There was a great variability in urinary citrate levels in both groups, and a considerable overlap in the urinary citrate excretion between normal subjects and stone formers. Factors other than urinary citrate excretion must therefore be of importance in the pathophysiology of calcium stone formation. ...

1993-01-01

323

Chemical neutralization to control denting in nuclear steam generators  

International Nuclear Information System (INIS)

Laboratory testing at Combustion Engineering has indicated promise in controlling simulated steam generator tube denting through chemical neutralization. Testing was limited to on-line treatment, and two neutralizers have been evaluated: calcium hydroxide and boric acid. On-line treatment with calcium hydroxide successfully halted active denting whenever the bulk calcium concentration (in ppm) equaled or exceeded the bulk chloride concentration (in ppm). Calcium hydroxide also was effective as an alternative to ammonia as a pH controlling agent in two tests conducted without ingress of chloride. On-line treatment with boric acid consisted of a four-day soak at simulated low (approximately 30 percent) power with 50 ppm B followed by one month full-power operation with 10 ppm B. This treatment also halted denting. Nondestructive and destructive examination of test boilers gave no indication of adverse ...

324

Case series of maxillary sinus augmentation with biphasic calcium phosphate: a clinical and radiographic study  

UK PubMed Central (United Kingdom)

PurposeThe aim of this study was to evaluate 3.5 years-cumulative survival rate of implants placed on augmented sinus using Osteon, a bone graft material, and to assess the height...Full Text Available

2011-04-01

325

Calcium/Calmodulin-Dependent Protein Kinase II Mediates Hippocampal Glutamatergic Plasticity During Benzodiazepine Withdrawal  

UK PubMed Central (United Kingdom)

Benzodiazepine withdrawal anxiety is associated with potentiation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptor (AMPAR) currents in hippocampal CA1 pyramidal...Full Text Available

2010-08-01

326

Calcium gradients and buffers in bovine chromaffin cells.  

UK PubMed Central (United Kingdom)

1. Digital imaging and photometry were used in conjunction with the fluorescent Ca2+ indicator, Fura-2, to examine intracellular Ca2+ signals produced by depolarization of single adrenal chromaffin...Full Text Available

1992-05-01

327

Calcium Effects on Stomatal Movement in Commelina communis L. 1  

UK PubMed Central (United Kingdom)

Stomatal movements depend on both ion influx and efflux; attainment of steady state apertures reflects modulation of either or both processes. The role of Ca2+ in those two processes was...Full Text Available

1988-07-01

328

Cadherin Mechanics and Complexation: The Importance of Calcium Binding  

UK PubMed Central (United Kingdom)

E-cadherins belong to a family of membrane-bound, cellular adhesion proteins. Their adhesive properties mainly involve the two N-terminal extracellular domains (EC1 and EC2). The junctions between these...Full Text Available

2005-12-01

329

Amyloid Oligomer Neurotoxicity, Calcium Dysregulation, and Lipid Rafts  

UK PubMed Central (United Kingdom)

Amyloid proteins constitute a chemically heterogeneous group of proteins, which share some biophysical and biological characteristics, the principal of which are the high propensity to acquire an incorrect...Full Text Available

330

Age-dependent changes in Ca2+ homeostasis in peripheral neurones: implications for changes in function  

UK PubMed Central (United Kingdom)

Calcium ions represent universal second messengers within neuronal cells integrating multiple cellular functions, such as release of neurotransmitters, gene expression, proliferation, excitability,...Full Text Available

2007-06-01

331

Acetylsalicylic acid as soluble tablets  

International Science & Technology Center (ISTC)

Realization of Pharmacological Tests, Development of the Specifications and Technical Documentation and Registration in the Russian Federation of Medical Products as Soluble Tablets of Acetylsalicylic Acid/Calcium Carbonate in Two Dosages Intended for use as Medical Products Smoothing, Febrifugal and Antiaggregation Action and Development of Technology of Tableting the Above-Stated Preparations

332

A new method to measure necrotic core and calcium content in coronary plaques using intravascular ultrasound radiofrequency-based analysis  

UK PubMed Central (United Kingdom)

Although previous intravascular ultrasound (IVUS) radiofrequency-based analysis data showed acceptable reproducibility for plaque composition, measurements are not easily obtained, particularly that...Full Text Available

2010-04-01

333

A mathematical/physiological model of parathyroid hormone secretion in response to blood-ionized calcium lowering in vivo.  

DEFF Research Database (Denmark)

The aim of the present study was to test a mathematical model of the biochemical processes in the parathyroid glands responsible for the secretion of parathyroid hormone resulting from extracellular calcium reduction. A double exponential curve described the parathyroid hormone secretion induced by rapid lowering of blood-ionized calcium in humans with normal as well as abnormal parathyroid tissue. Our data show that it was possible to establish a simple mathematical model of the parathyroid hormone response to blood-ionized calcium lowering, sufficient to fit experimental data obtained from patients with abnormal and normal parathyroid tissue. The fitted parameters showed no significant differences between patients with insulin-dependent diabetes mellitus and controls. In primary hyperparathyroidism, the parathyroid hormone production and steady-state transport across the cell membrane were increased, probably due to the ...

1997-01-01

334

A Kinetic Model of Dopamine- and Calcium-Dependent Striatal Synaptic Plasticity  

UK PubMed Central (United Kingdom)

Corticostriatal synapse plasticity of medium spiny neurons is regulated by glutamate input from the cortex and dopamine input from the substantia nigra. While cortical stimulation alone results in long-term...Full Text Available

2010-02-01

335

* NASA TECHNICAL TRANSLATION NASA TT F-11435 INFLUENCE OF ...  

Science.gov (United States)

isotherme, dans un courant d'azote ou sous vide entretenu. I t. Comptes Rendus Scientific Academy, Paris, Vol. 265 pyrolyse du carbonate de calcium, ...

336

Yttrium Calcium Oxyborate for high average power frequency doubling and OPCPA  

Science.gov (United States)

Significant progress has been achieved recently in the growth of Yttrium Calcium Oxyborate (YCOB) crystals. Boules have been grown capable of producing large aperture nonlinear crystal plates suitable for high average power frequency conversion or optical parametric chirped pulse amplification (OPCPA). With a large aperture (5.5 cm x 8.5 cm) YCOB crystal we have demonstrated a record 227 W of 523.5nm light (22.7 J/pulse, 10 Hz, 14 ns). We have also demonstrated the applicability of YCOB for 1053 nm OPCPA.

2006-06-20

337

The early days of parathyroid surgery.  

Science.gov (United States)

The parathyroid endocrine glands, usually four in number and about the size of a split pea, lie on either side of the posterior aspect of the thyroid gland. Occasionally one or more of these structures are found in an aberrant position in the neck or even in the superior mediastinum. The parathyroid secretion, parathormone, regulates the level of serum calcium within sharply defined limits. Lack of parathormone, with lowering of the serum calcium, results in hyper-irritability of skeletal muscle, the clinical condition known as tetany. This is encountered following inadvertent removal or bruising of the parathyroid glands at thyroidectomy. PMID:21488463

2011-03-01

338

Physical aspects of FGD by-products  

Energy Technology Data Exchange (ETDEWEB)

Air pollution constraints continue to intensify, resulting in solid waste volume increases. An example of this is coal burning power plant flue gas desulfurization by scrubbing. The aqueous suspensions of calcium sulfate hemihydrate or calcium sulfate dihydrate will exceed 200 million tons annually by the year 2000. Disposal of these wastes can have massive environmental effects, due to physical instability and leaching to groundwater. One alternate disposal technique is sulfopozzolanic fixation, converting the FGD waste by addition of fine coal ash and an alkaline earth additive, into a monolithic mass. 6 refs., 17 figs., 3 tabs.

1992-01-01

339

Method of producing calcium sulfate semihydrate in conjunction with the desulfurization of flue gases  

Energy Technology Data Exchange (ETDEWEB)

Calcium sulfate dihydrate in large crystal form is produced by maintaining the circulation of the lime containing scrubbing solution in the desulfurization scrubbing of flue gases from a power plant boiler so that it has a residence time of 5 to 25 hours, preferably 15 hours. The crystals are moved by passing a portion of the recirculation through a thinner in which a sludge containing crystals with a mean particle size of which 90% is in excess of 100 microns is removed. This product can be dewatered and treated with sulfuric acid and steam to convert it to the alpha semihydrate and is free from sulfite.

1985-03-05

340

Heat storage composition  

Energy Technology Data Exchange (ETDEWEB)

A heat storage compostion comprises sodium sulfate decahydrate as main component, a supercooling inhibitor, and a solid-liquid separation inhibitor. The composition is characterized in that hydraulic calcium sulfate and/or calcium sulfate dihydrate is contained as the solid-liquid separation inhibitor in an amount of 2-15 wt% base on the whole weight of the composition, whereby the solid-liquid separation, i.e. the sedimentation of the anhydrous sodium sulfate during the phase transition, is effectively prevented and the long-term stability is improved. The long-term stabilty of the composition can be more improved by addition of a silcia series of thickener.

1987-05-05

341

Exact solution to NO/sub 2/ absorption  

Energy Technology Data Exchange (ETDEWEB)

This paper describes an exact solution to the problem of absorbing nitrogen dioxide into aqueous solution, in which case the nitrogen dioxide concentration is allowed to vary over a wide range. The authors have worked on the rate of calcium sulfate dihydrate scale formation on the reverse osmosis membrane and find this phenomena can be treated by the crystallization theory. The authors performed long-term experiments using calcium sulfate dihydrate solution with addition of sodium hexametaphosphate (SHMP) and commercially available organophosphates and investigated the mechanism of the inhibitor's action quantitatively.

1984-04-01

342

Laser induced local and periodic phase transformations in iron oxide thin films obtained by chemical vapour deposition  

International Nuclear Information System (INIS)

Iron oxide films have been deposited on Si(100) substrates by chemical vapour deposition (CVD) of iron(III) tert-butoxide ([Fe(O "tBu)_3]_2) in the temperature range 350-450 deg. C. The precursor flux and substrate temperature were varied to control the phase composition, average grain size and film thickness. The nature of substrate and deposition temperature markedly influence the morphology and iron-oxygen stoichiometry in the CVD deposits. Phase transformations in iron oxide films were achieved through precise local and periodic heating of the films by interfering laser beams. The interaction of iron oxide films with short laser pulses (Nd:YAG, 355 nm) induced partial transformation of hematite (#alpha#-Fe_2O_3) to magnetite (Fe_3O_4) or magnetite to wuestite (Fe_1_-_xO), respectively. The phase characterization and morphology of the hematite and magnetite films were ...

2005-07-15

343

Exploring the 2D to 3D dimensionality crossover in thin iron films  

Energy Technology Data Exchange (ETDEWEB)

The temperature dependence of the spontaneous magnetization of epitaxial iron films with a thickness ranging from d=20 to 200nm has been measured. The films are grown on GaAs (100) substrates which are covered by a 150nm thick silver (100) buffer layer. For three-dimensional BCC iron it was observed already in 1929 that saturation of the spontaneous magnetization for T->0 is perfectly described by a T{sup 2} power law. On the other hand, for thin two-dimensional (2D) iron films a T{sup 3/2} law has been established in many recent experimental investigations. In our iron films grown on diamagnetic silver, this dimensionality change occurs at a thickness between d=100 and 200nm. Comparison of the here-observed T{sup 3/2} coefficients with those on iron films grown on paramagnetic tungsten (110) shows that the 2D interactions are {approx}20 times larger in the films on tungsten. ...

2006-05-15

344

Enhancement of corrosion protection efficiency of iron by poly(aniline-co-amino-naphthol-sulphonic acid) nanowires coating in highly acidic medium  

International Nuclear Information System (INIS)

Nanowires of copolymers film based on aniline and 1-amino-2-naphthol-4-sulphonic acid were electrochemically synthesized on the iron electrode by cyclic voltammetry using oxalic acid as a supporting electrolyte. Protective properties of copolymer film on the iron surface in 1.0 M HCl solution was investigated by chronoamperometry, potentiodynamic polarization technique and electrochemical impedance spectroscopy (EIS). The results showed that the copolymer film showed the significant shifting in the corrosion potential and greater charge transfer resistance. Moreover, the copolymer showed the larger degree of surface coverage onto the iron surface, reflecting the higher protection for corrosion of the iron in acidic medium. In addition, the film constitutes a physical as well as a chemical barrier layer due to the presence of -OH and -NH groups in ANSA unit, which provides passivity protection in polymer ...

2010-11-30

345

Enhanced corrosion resistance by sol-gel-based ZrO_2-CeO_2 coatings on magnesium alloys  

International Nuclear Information System (INIS)

The physical, chemical and mechanical properties of magnesium alloys make them attractive materials for automotive and aerospace applications. However, these materials are susceptible to corrosion and wear. This work discusses the potential of using sol-gel based coatings consisting of ZrO_2 and 15 wt.% of CeO_2. The CeO_2 component provides enhanced corrosion protection, while ZrO_2 impart corrosion as well as wear resistance. Coating deposition was performed by the dip coating technique on two magnesium alloy substrates with different surface finishes: AZ91D (as-casted, sand-blasted, and machined) and AZ31 (rolled and machined). All as-deposited coatings (xerogel coatings) were then subjected to 10 h annealing: a temperature of 180 C was applied to the AZ91D alloy and 140 C to the AZ31 alloy. Morphological and structural properties of the annealed coatings were investigated by scanning electron microscopy, atomic force microscopy and ...

2005-02-01

346

Development of zirconium alloys. Part II  

Science.gov (United States)

A number of alloys of zirconium have been investigated as part of a program aimed at improving the high-temperature tensile and creep strength of zirconium. These alloys include aluminum, beryllium, lead, magnesium, molybdenum, niobium, tantalum, tin, titanium, tungsten, vanadium, and zinc, binary and ternary alloys. The data indicate that aluminum, lead, molybdenum niobium, tin, titanium, tungsten, and vanadium can be used successfully to harden zirconium, and that aluminum, tin, titanium, and vanadium are particularly effective in maintaining the strength of zirconium at elevated temperatures.

1952-01-02

347

Corrosion behaviors of Zn/Al-Mn alloy composite coatings deposited on magnesium alloy AZ31B (Mg-Al-Zn)  

International Nuclear Information System (INIS)

After being pre-plated a zinc layer, an amorphous Al-Mn alloy coating was applied onto the surface of AZ31B magnesium alloy with a bath of molten salts. Then the corrosion performance of the coated magnesium alloy was examined in 3.5% NaCl solution by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results showed that the single Zn layer was active in the test solution with a high corrosion rate while the Al-Mn alloy coating could effectively protect AZ31B magnesium alloy from corrosion in the solution. The high corrosion resistance of Al-Mn alloy coating was ascribed to an intact and stable passive film formed on the coating. The performances of the passive film on Al-Mn alloy were further investigated by Mott-Schottky curve and X-ray photoelectron spectroscopy (XPS) analysis. It was confirmed that the passive film exhibited n-type semiconducting behavior in 3.5% NaCl solution with a ...

2009-12-30

348

A Flow Stress Formulation of Magnesium Alloy at Elevated Temperature  

International Nuclear Information System (INIS)

Dynamic recrystallization (DRX) is the main softening mechanism of magnesium alloy AZ31B in hot deformation. Theoretically, in the flow rule the atomic diffusibility and the driving force of dislocation migration are dependent on the temperature, and the dislocation density and the cumulation of grain boundary energy are dependent on the strain rate. The peak stress will appear when the flow driving force and resistance force reach a balance, after which the stress descending will take place due to recrystallization fraction. Since the DRX is a thermally activated process, the recrystallized volume fraction can be regarded as the function of strain through Avrami equation. Based on this idea, the paper proposes a new constitutive model characterizing dynamic recrystallization for magnesium alloy AZ31B. The model is described by a peak stress and a strain softening rate, in which the peak stress depends only on Zener-Hollomon parameter and is ...

2007-05-17

349

On the hydrogen etching mechanism in plasma nitriding of metals  

International Nuclear Information System (INIS)

Iron alloys and aluminum were nitrogen implanted in a controlled oxygen atmosphere and the role of hydrogen on the surface etching mechanisms studied. The surface composition was analyzed by in situ photoemission electron spectroscopy (XPS). In iron alloys, hydrogen strongly etches oxygen, improving nitrogen retention on the surface. On the other hand, hydrogen removes nitrogen from aluminum surfaces, with a deleterious effect on the nitriding effectiveness. The oxygen removal in iron alloys is associated with the catalytic effect of electrons in d-orbitals and the nitrogen removal in aluminum is associated with a steric effect.

2006-12-15

350

Magnetic separation of antibiotics by electrochemical magnetic seeding  

Energy Technology Data Exchange (ETDEWEB)

Magnetic separation of several classes of antibiotics was investigated using electrochemical magnetic seeding. Electrocoagulation with a sacrificial anode followed by addition of magnetite particles was applied for the magnetic seeding of antibiotics. With electrochemical magnetic seeding using an iron anode, tetracycline antibiotics (oxytetracycline, chlortetracycline, doxycycline and tetracycline) and cephalosporin antibiotic (cefdinir) were rapidly removed from synthetic wastewater by magnetic separation using a neodymium magnet. Iron and aluminium anodes were suitable for magnetic seeding of the antibiotics. The results indicated that the ability of antibiotics to form strong complex with iron and aluminium allowed the higher removal by magnetic separation. This method would be appropriate for rapid treatment of antibiotics in wastewater.

2009-03-01

351

Computer processing of Moessbauer spectrum data  

International Nuclear Information System (INIS)

Computer processing was adopted to pick up significant signals from the undefined Moessbauer spectra. A program, by which smoothing and curve fitting was made possible, was devised and applied to the analysis of the Moessbauer spectra of "5"7Fe enriched iron and other specimens. Although this processing sometimes distorted the absorption peaks, it was quite effective for elimination of noise and finding of exact positions of absorption peaks. Availability of the processing was demonstrated by several examples obtained for "5"7Fe enriched iron, natural iron, calcined ferric oxyhydroxides, red mud residue and its calcined product. (auth.).

352

An intracranial aspergilloma with low signal on T2-weighted images corresponding to iron accumulation  

Energy Technology Data Exchange (ETDEWEB)

We present a case of cerebral aspergillosis in an immunocompetent patient. The MRI signal characteristics were compared with the histologic findings. Irregular low-signal zones were demonstrated between the wall of the abscess and the central necrosis on T2-weighted images; the pathology specimen revealed concentrated iron in these transitional zones but no hemosiderin. Iron is an essential element for the growth of fungal hyphae. The low-signal zones may represent the areas where there was active proliferation of aspergillus, and the unique location of the low signal may be a helpful imaging characteristic for the diagnosis of an aspergillus abscess. (orig.)

2001-07-01

353

WHAT OLD MEANS TO BONE  

UK PubMed Central (United Kingdom)

The adverse effects of aging of other organs (ovaries at menopause) on the skeleton are well known, but ironically little is known of skeletal aging itself. Evidence indicates that age-related...Full Text Available

2010-06-01

354

Urinary catecholamines in iron deficiency anemia: effects of environmental temperature  

Energy Technology Data Exchange (ETDEWEB)

Iron deficiency (ID) is associated with increased levels of norepinephrine (NE) in plasma and urine. They investigated the effect of 5-7 days exposure to three different environmental temperatures (10/sup 0/C, 24/sup 0/C, 30/sup 0/C) on urinary catecholamine levels to test the hypothesis that increased thermogenic activity is causal to this increased excretion in iron deficiency. Catecholamines were analyzed from acidified urine by HPLC-EC. The mean Hb in ID animals was 3.1 +/- .5 versus controls of 12.8 +/- 9. These data demonstrate that contrary to previous reports NE excretion is not normalized at a thermoneutral temperature and suggests a basic abnormality in peripheral SNS activity and NE metabolism in iron deficiency that is independent of environmental drive from thermogenesis.

1986-03-05

355

Tuning the spin state of iron phthalocyanine by ligand adsorption  

International Nuclear Information System (INIS)

The future use of single-molecule magnets in applications will require the ability to control and manipulate the spin state and magnetization of the magnets by external means. There are different approaches to this control, one being the modification of the magnets by adsorption of small ligand molecules. In this paper we use iron phthalocyanine supported by an Au(111) surface as a model compound and demonstrate, using x-ray photoelectron spectroscopy and density functional theory, that the spin state of the molecule can be tuned to different values (S #approx# 0, 1/2, 1) by adsorption of ammonia, pyridine, carbon monoxide or nitric oxide on the iron ion. The interaction also leads to electronic decoupling of the iron phthalocyanine from the Au(111) support. (fast track communication)

2010-12-01

356

The mammalian neuroendocrine hormone norepinephrine supplies iron for bacterial growth in the presence of transferrin or lactoferrin.  

Science.gov (United States)

Norepinephrine stimulates the growth of a range of bacterial species in nutritionally poor SAPI minimal salts medium containing 30% serum. Addition of size-fractionated serum components to SAPI medium indicated that transferrin was required for norepinephrine stimulation of growth of Escherichia coli. Since bacteriostasis by serum is primarily due to the iron-withholding capacity of transferrin, we considered the possibility that norepinephrine can overcome this effect by supplying transferrin-bound iron for growth. Incubation with concentrations of norepinephrine that stimulated bacterial growth in serum-SAPI medium resulted in loss of bound iron from iron-saturated transferrin, as indicated by the appearance of monoferric and apo- isoforms upon electrophoresis in denaturing gels. Norepinephrine also caused the loss of iron from lactoferrin. The pharmacologically inactive ...

2000-11-01

357

Synergistic effect of iodide ion and polyacrylic acid on corrosion inhibition of iron in H2SO4 investigated by electrochemical techniques  

British Library Electronic Table of Contents (United Kingdom)

Corrosion inhibition of iron in H2SO4 by polyacrylic acid (PAA) was investigated using electrochemical techniques at 30degreeC. Results obtained indicate that PAA inhibited the corrosion of iron in the acid medium. Inhibition efficiency increases with increase in PAA concentration and synergistically enhanced on addition of iodide ions. Potentiodynamic polarization results suggest that PAA functions as a modest cathodic inhibitor. The adsorption of PAA onto the iron surface followed Temkin adsorption isotherm. FTIR analysis revealed that the synergistic effect due to co-adsorption of iodide ions and PAA is co-operative in nature.

2010-01-01

358

PPT - AstroGravS - NASA  

Science.gov (United States)

Form as the end result of massive star evolution; Type II supernova: collapse of iron core in highly evolved massive star; outer regions blasted away in ...

359

Novel Magnetic Fluids for Breast Cancer Therapy  

Science.gov (United States)

... metal-oleate complexes. At this point, this method has been reported only for iron nanoparticles [15]. We have demonstrated ...

2008-01-01

360

N79-27658 Potential for Cogeneration of Heat and Electricity in ...  

Science.gov (United States)

nances, an iron ore sintering plant, and several fuel oil boilers.***. The use of undemonstrated technology presents problems for evaluatingi ...

361

Ischemic-Anoxia of the Central Nervous System: Iron ...  

Science.gov (United States)

... Joint Staff and other US Military (ie, Army, Navy, Air ... The major products of this work are significant advances in ... Keywords: Dogs; Laboratory animals ...

1986-10-15

363

Intrepidity, Iron Will, and Intellect: General Robert L. ...  

Science.gov (United States)

... John F. Shortal's Forged by ... Harold ... As a youth, Eichelberger read the works of Shakespeare, Dickens, Thackeray, and Bulwer-Lyton. ...

2004-06-17

365

Green synthesis of iron nanoparticles and their application as a Fenton-like catalyst for the degradation of aqueous cationic and anionic dyes  

British Library Electronic Table of Contents (United Kingdom)

Iron nanoparticles were produced using extracts of green tea leaves (GT-Fe NPs). The materials were characterized using TEM, SEM/EDX, XPS, XRD, and FTIR techniques and were shown to contain mainly iron oxide and iron oxohydroxide. The obtained nanoparticles were then utilized as a Fenton-like catalyst for decolorization of aqueous solutions containing methylene blue (MB) and methyl orange (MO) dyes. The related experiments investigated the removal kinetics and the effect of concentration for both MB and MO. The concentrations of dyes in aqueous solution were monitored using ultraviolet-visible (UV-vis) spectroscopy. The results indicated fast removal of the dyes with the kinetic data of MB following a second order removal rate, while those of MO were closer to a first order removal rate. T...

2011-01-01

366

Gamma-spectroscopy of "6"4Mn_3_9 and "6"6Mn_4_1 decays  

International Nuclear Information System (INIS)

... v. 33(4). beta-minus decay de-excitation delayed gamma radiation iron 64

367

Electrochemical and ellipsometric investigations of Passive Films formed on iron in borate solutions: the kinetics of film growth on iron at constant anodic potentials  

Energy Technology Data Exchange (ETDEWEB)

The kinetics of passive film formation on iron in borate buffer solution has been studied at different anodic potentials. The process of film growth has been found to occur in four distinct stages. About 80-90% of the total film thickness formed in 1h grows during the initial two stages which last for only 1-3s (depending upon potential). The electric field strength across the film is not constant but decreases with progressing film growth. The thickness of the film determined ellipsometrically is less than that calculated from the electric charge consumed. The process of anodic film formation is accompanied by the dissolution of iron which occurs over the whole range of potentials.

1984-02-01

369

Double perovskite catalysts for oxidative coupling  

Energy Technology Data Exchange (ETDEWEB)

Alkali metal doped double perovskites containing manganese and at least one of cobalt, iron and nickel are useful in the oxidative coupling of alkane to higher hydrocarbons.

1991-01-01

370

Dislocation structure and mechanical properties of. cap alpha. -iron in dependence on plastic deformation conditions  

Energy Technology Data Exchange (ETDEWEB)

Investigations of dislocation structure and mechanical properties of iron after rolling deformation in shaped rolls and after hydroextrusion are conducted. It is shown that dislocation iron structure slightly changes with deformation degree after rolling in shaped rolls and annealing and it is characterized by low density of screw dislocations. Cold brittleness temperature decreases in the result of rolling and the succeeding recrystallization and impact strength increases both at room temperature and at low temperatures. Screw dislocations having high Peierls barrier prevail in the structure after hydroextrusions. The iron deformed by hydroextrusion at 400 mPa and higher after annealing has high cold brittleness temperature and low impact strength.

1982-03-01

371

Deposition of inhaled aerosols in beagle dogs  

International Nuclear Information System (INIS)

Additional measurements have been made of deposition and retention of inhaled radioactively labeled iron oxide aerosols generated by a spinning top aerosol generator.

1977-05-01

372

Comparison of LAHET code system calculations with experimental results for protons of energies less than 50 MeV incident on copper and iron  

Energy Technology Data Exchange (ETDEWEB)

The LAHET code system calculations and experimental results for proton interactions with an energy <50 MeV are compared. For these energies, the theories behind the LAHET models are not applicable. Three quantities compared are (a) the magnitude of the neutron yield generated through proton interactions, (b) the energy and angular distributions of the resultant neutrons, and (c) the residual nuclei produced by proton interactions (spallation products). The comparisons are for protons incident on iron and copper, except in the case of the energy and angular distributions, which are calculated only for iron. The neutron yields predicted by LAHET agree with published measurements to within 50% for both materials. For iron, the predicted energy and angular distributions agree to within a factor of 3. Finally, the predicted spallation product yields of both materials agree with measurements to within a factor of 4.

1997-03-01

373

Are Stars with Planets Polluted?  

CERN Document Server

We compare the metallicities of stars with radial velocity planets to the metallicity of a sample of field dwarfs. We confirm recent work indicating that the stars-with-planet sample as a whole is iron rich. However, the lowest mass stars tend to be iron poor, with several having [Fe/H]0.48) that contributes to but does not explain the mass-metallicity trend in the stars-with-planets sample. We use Monte Carlo models to show that adding an average of 6.5 Earth masses of iron to each star can explain both the mass-metallicity and the age-metallicity relations of the stars-with-planets sample. However, for at least one star, HD 38529, there is good evidence that the bulk metallicity is high. We conclude that the observed metallicities and metallicity trends are the result of the interaction of three effects; accretion of about 6 Earth masses of iron rich material, selection effects, and in some cases, ...

2002-01-01

374

Abstract - NASA Technical Report Server (NTRS)  

Science.gov (United States)

This suggests that Ms of the iron nanoparticles is about 125 emu/g, about half of M~u.lk, which contradicts previous reports on transition metals. ...

375

A child with hyperferritinemia: Case report  

UK PubMed Central (United Kingdom)

Hereditary hyperferritinemia cataract syndrome (HHCS) is a rare condition caused by mutations in the gene coding for the light chain of ferritin; it does not lead to iron overload, but it is associated...Full Text Available

376

The molybdenum iron-sulphur protein from Desulfovibrio gigas as a form of aldehyde oxidase.  

UK PubMed Central (United Kingdom)

The molybdenum iron-sulphur protein originally isolated from Desulfovibrio gigas by Moura, Xavier, Bruschi, Le Gall, Hall & Cammack [(1976) Biochem. Biophys. Res. Commun. 72, 782-789] has been...Full Text Available

1987-05-01

377

The method for iron removal from cadmium in the course of refining process; Sposob usuwania zelaza z kadmu w procesie jego rafinacji  

Energy Technology Data Exchange (ETDEWEB)

The pyrometallurgic method consisting in introduction of refining agent into the liquid cadmium has been presented. The refining agent consisting of silicon nitride, carbon dust and sodium hydroxide has been added in several portion into the liquid cadmium. Iron has been removed from the cadmium surface in the form of floating slag.

1992-10-30

378

MCNPX analysis of 68 MeV neutron transmission on iron  

Energy Technology Data Exchange (ETDEWEB)

A 68 MeV neutron transmission experiment on iron has been analyzed with MCNPX using the Los Alamos LA150 neutron data library, the ECN/BRC 150 MeV neutron data library and with the intranuclear cascade code LAHET. The clear improvement of using the data libraries is confirmed. Also, other materials present in LA150 have been checked using the same MCNPX set-up. 10 refs.

1999-02-01

379

Impact of the ENDF/B-VI Cross Section on the RPV Fluence Determination  

Energy Technology Data Exchange (ETDEWEB)

The calculations with the broad-group cross-section library Bugle-96, and atom displacement (dpa) cross sections for iron, both derived from ENDF/B-VI data, result in higher calculated fast neutron fluxes, better agreement of calculations with radiometric dosimeter measurements, and significantly slower dpa rate attenuation through pressure vessel walls relative to the results with their predecessors: the Sailor library and ASTM iron dpa cross sections.

1999-09-12

380

Electron impact excitation of lithium-like iron  

Energy Technology Data Exchange (ETDEWEB)

Calculations of total and angle-differential excitation cross sections for the electron impact excitation of lithium-like iron were performed with the R-matrix formulation. The alignments of the excited states 1s{sup 2}np {sup 2}P{sub 3/2} are also presented for n=3 and 4 along with the angular photon distribution from these states to the ground state. Relativistic effects were included in the present calculations by the Breit-Pauli Hamiltonian.

1996-05-01

381

Development of coal utilization technology in the Japanese steel industry - co-operation with coal suppliers  

Energy Technology Data Exchange (ETDEWEB)

Past and current development of coal utilization technology in the Japanese steel industry is reviewed and some projects currently under research and development briefly described. These include DIOS, an iron making process which directly utilizes both iron ore and coal without a sintering plant or a coke oven; and the development of a new generation coke oven. 15 figs.

1994-12-31

382

Coal liquefaction catalzsed by iron ores. Catalytic activities of laterite ores  

Energy Technology Data Exchange (ETDEWEB)

The catalytic activities of various iron ores were investigated in the search for a high-activity catalyst for direct coal liquefaction. Laterite ores were shown to have a high catalytic activity in this process. Comparison of the ore with red mud in hydrocracking of 1-methylnaphthalene showed that the ore had higher activity in the hydrogenation of aromatic rings and in hydrocracking of alkylaromatics.

1984-10-01

383

Optimizing the specific surface area of fly ash-based sorbents for flue gas desulfurization.  

Science.gov (United States)

High performance sorbents for flue gas desulfurization can be synthesized by hydration of coal fly ash, calcium sulfate, and calcium oxide. In general, higher desulfurization activity correlates with higher sorbent surface area. Consequently, a major aim in sorbent synthesis is to maximize the sorbent surface area by optimizing the hydration conditions. This work presents an integrated modeling and optimization approach to sorbent synthesis based on statistical experimental design and two artificial intelligence techniques: neural network and genetic algorithm. In the first step of the approach, the main and interactive effects of three hydration variables on sorbent surface area were evaluated using a full factorial design. The hydration variables of interest to this study were hydration time, amount of coal fly ash, and amount of calcium sulfate and the levels investigated were 4-32 h, 5-15 g, and 0-12 g, respectively. In ...

2005-07-05

384

Gastrointestinal absorption of lead (/sup 203/Pb) in chicks: influence of lead, calcium, and age  

Energy Technology Data Exchange (ETDEWEB)

The present study was designed to investigate, in more detail, the mechanism of lead transport by the gastrointestinal tract and particularly the similarities or dissimilarities between lead and calcium in this process. The absorption of these metals was determined in 3-week-old white Leghorn cockerels, raised on a commercial diet or special diets, using an in vivo ligated loop procedure. The dose administered into the loop usually contained 0.5 ..mu..Ci /sup 203/Pb (and/or 0.1 ..mu..Ci /sup 47/Ca), 0.01 mM lead acetate (and/or 1 mM CaCl/sub 2/) in 0.5 ml of 0.15 M NaCl, pH 6.5. It was shown that lead is rapidly taken up by the intestinal tissue, and only slowly transferred into the circulation whereas calcium, also accumulated rapidly by the tissue, is rapidly released from the tissue in the serosal direction. The absorption processes of these cations show similar responses to various experimental conditions (low calcium ...

1981-10-01

385

Contribution of calcium ions and hydrogen ions to the signal transduction chain in phytochrome-mediated spore germination. [Onoclea sensibilis L  

Energy Technology Data Exchange (ETDEWEB)

Red light stimulates germination in the spores of Onoclea sensibilis L. Phytochrome is confirmed to be the photoreceptor pigment in the germination response by demonstrating red-far-red photoreversibility. External Ca/sup 2 +/ is required for this response with a threshold at a submicromolar concentration. Red light stimulates an increase in the total concentration of intracellular calcium in the spores as determined by atomic absorption spectroscopy. Subsequent exposure to far-red light inhibits the red light-induced increase in intracellular calcium. The majority of the increase occurs 5 minutes after the onset of irradiation. The calcium-antagonist, La/sup 3 +/ inhibits both germination and the red light-induced increase in intracellular calcium. Using /sup 31/P-nuclear magnetic resonance spectroscopy, the author tested the hypothesis that a sustained increase in intracellular pH contributes to the ...

1985-01-01

386

XPS study on the correlation between chemical state and oxygen-sensing properties of an iron oxide thin film  

International Nuclear Information System (INIS)

We have studied the correlation between the chemical state and the oxygen-sensing properties of an iron oxide thin film using a setup that allows simultaneous sensor resistance measurements and X-ray photoelectron spectroscopy (XPS) data acquisition. The gas exposures were performed at the highest operating pressure of the XPS spectrometer at a controlled sample temperature which allows direct comparison between the sensor response and the chemical state of the surface. The iron oxide film was modified by a sequence of argon ion sputtering steps and the induced changes in the chemical state, resistance, and sensitivity to oxygen were investigated. The sputtering was found to reduce the iron from the Fe"3"+ to the Fe"2"+ state and to decrease the sensor resistance. The measured sensitivity to oxygen first increased by a factor of two but then collapsed to its original level. The mechanism for oxygen sensing was found to be ...

2007-10-15

387

Structural, optical, electrical and dielectrical properties of electrosynthesized nanocrystalline iron oxide thin films  

International Nuclear Information System (INIS)

Electrodeposition of semiconducting iron oxide (Fe_2O_3) thin film was carried out from an alkaline sulphate bath. A 0.1 M ferrous sulphate (FeSO_4#centre dot#7H_2O) was complexed with 0.1 M citric acid. By addition of 1 N NaOH, pH of the solution was made alkaline (pH=9) and deposition of iron oxide (Fe_2O_3) thin films was carried out potentiostatically at room temperature (300 K). From cyclic voltametry (CV), electrochemical studies were carried out for deposition of iron oxide thin films. The XRD studies reveal that Fe_2O_3 with epsilon (#epsilon#) phase having monoclinic crystal structure is formed. By observing scanning electron microscope (SEM), it is seen that iron oxide films were homogeneous, uniform and well covered to surface of the substrate. Grain size was found to be in nanometers range from XRD analysis. The optical band gap of Fe_2O_3 thin film was estimated to be 1.90 eV. Electrical ...

2003-09-28

388

Mechanism of pyrrhotite formation from ferric oxyhydroxide catalyst; Kokoritsu sekitan ekika shokubai no kaihatsu (Okishi suisankatetsu shokubai karano pyrrhotite seisei kyodo)  

Energy Technology Data Exchange (ETDEWEB)

It is thought that iron-based catalysts for coal liquefaction exercise their catalytic activity by forming pyrrhotite (Fe(1-x)S). However, there are still a lot of unknown problems remained concerning the formation and agglomeration behaviors of pyrrhotite. These make a difficulty for improving the activity of iron-based catalysts. In this study, sulfiding behaviors of {alpha}-iron oxyhydroxide ({alpha}-FeOOH) and {gamma}-iron oxyhydroxide ({gamma}-FeOOH) were investigated to reveal the formation and agglomeration behaviors of pyrrhotite. It was found that pyrrhotite was easily converted from ferric oxyhydroxide catalysts having large specific surface areas at the sulfiding temperature below 250{degree}C, and fine crystallites of pyrrhotite were formed at the initial stage of sulfiding. Crystal growth of pyrrhotite at the sulfiding temperature over 350{degree}C depended on the catalyst forms. It was ...

1996-10-28

389

Effect of limestone and iron ore additives on ash fusion behavior  

Energy Technology Data Exchange (ETDEWEB)

Effect of Limestone, iron ore and red mud as a flux for hot coal gasification wastes was examined as they are regarded easily available, pollution-less and less costly. (1) Fusion behavior of ash-iron ore mixture and ash-limestone mixture approximately coincided with that of the reagent; red mud with low iron purity also coincided when the addition was less than 40%. (2) According to a microscopic observation, localized melting of the ash was observed even at 900 - 950/sup 0/C which was lower than the mpt. by almost more than 100/sup 0/C, which was attributed to the formation of iron-based compound. (3) The softening point reduced down to 1000 - 1050/sup 0/C irrespective of type of ash or ion-based flux; they were in the form of slurry; it formed a slurry state by the localized melting of ashes. (4) At above mpt., most of the ash component minerals are liquid and evaporation of CO/sub 2/ or any low ...

1988-05-20

390

Direct measurement of the alpha-epsilon transition stress and kinetics for shocked iron  

Energy Technology Data Exchange (ETDEWEB)

Iron undergoes a polymorphic phase transformation from alpha phase (bcc) to the epsilon phase (hcp) when compressed to stresses exceeding 13 CPa. Bccause the epsilon phase is denser than the alpha phase, a single shock wave is unstable and breaks up into an elastic wave, a plastic wave, and a phase transition wave. Examination of this structured wave coupled with various phase transformation models has been used to indirectly examine the transition kinetics. Recently, multimillion atom simulations (molecular dynamics) have been used to examine the shock-induced transition in single crystal iron illustrating an orientation dependence of the transition stress, mechanisms, and kinetics. The objective of the current work was to perform plate impact experiments to examine the shock-response of polycrystalline and single crystal iron with nanosecond resolution for impact stresses spanning the {alpha} - {epsilon} transition. The ...

2009-01-01

391

Development of a cupola furnace process model. Final technical report  

Science.gov (United States)

A strategic partnership was formed among the American Foundrymen`s Society and the Federal government to develop and transfer the technology needed by the US foundry industry to: increase energy efficiency of cupola melting; improve recovery of carbon, silicon, and manganese through reduced oxidation losses; and improve productivity due to more uniform and predictable iron compositions. An effective mathematical model of the cupola offers a solution to the complex and interactive chemical and heat transfer processes to melt cast iron. The transient changes in charge size, charge composition, blast rate, and coke rate are used to optimize operation to improve melting rates, minimize oxidation losses of valuable alloying elements (C, Si, and Mn), and maintain iron composition. Despite these challenges, the cupola produces iron at a lower cost, and have better environmental controls than other melting ...

1995-07-01

392

Briquetting of self-reducing blendings of waste iron oxide mixtures. Final report  

Energy Technology Data Exchange (ETDEWEB)

The objectives of this project were to develop technologies to manufacture self-reducing briquettes out of waste iron oxides and to recycle them in an electric arc furnace or a cupola furnace. CRM has investigated and determined the optimal characteristics (binder, size, grain size, compositions and activator for the reduction reaction) for briquettes containing mixtures of mill scales, mill sludges, electric arc furnace (EAF) dust and coal as reduction agent. The goal of obtaining briquettes, in which iron oxides are totally reduced when these briquettes are loaded with the scrap into an electric arc furnace, was achieved. Trials at ProfilARBED have shown that it is possible to recycle mill and EAF by-products conditioned in self-reducing briquettes in an electric arc furnace without influence on the performance and on the environment. The iron content of the slag does not increase as the iron of the ...

2002-07-01

393

The seeded growth of calcium sulfate dihydrate crystals in NaCl solutions up to 6 m and 90 C  

Energy Technology Data Exchange (ETDEWEB)

The kinetics of calcium sulfate crystal growth is of importance in various fields, such as geochemistry, desalination technology, petroleum industry, and water and wastewater treatment. The seeded crystal growth rate of calcium sulfate dihydrate was measured as a function of supersaturation in NaCl electrolyte solutions from 0 to 6 m at temperatures of 25, 50, 70, and 90 C. The growth followed a second-order parabolic rate law with activation energies greater than 53 kJ/mol which suggested the surface reaction as the rate-limiting step. It was observed that the rate constant and the activation energy are solution composition dependent. The rate constant increases with NaCl concentration up to 3 molal and then begins to fall slightly. The activation energy dropped from 61 kJ/mol in the pure Ca-SO[sub 4]H[sub 2]O system to 53 kJ/mol in 3.0 m NaCl solutions. The electrolyte effect was similar to the crystal solubility behavior in aqueous ...

1994-03-15

394

Role of HCl in adsorption of elemental mercury vapor by calcium-based sorbents. Report for September 1998--May 1999  

Energy Technology Data Exchange (ETDEWEB)

The paper gives results of a study to identify active sites and surface functional groups that may contribute to the absorption of elemental mercury (Hg) by relatively inexpensive calcium (Ca)-based sorbents. The study investigated the formation of chlorine (Cl) sites in CA-based sorbents as well as their role and reactivity in the absorption of Hg. HCl-exposed calcium sulfate dihydrate (gypsum) exhibited a superior Hg sorption capability. Crystalline water molecules on the surface of the gypsum were confirmed to contribute indirectly to Hg uptake. These surface molecules may have absorbed HC1 through hydrogen bond formation between an oxygen atom of a crystalline water molecule and a hydrogen atom of an HCl molecule. Two adjacent, physically absorbed HCl molecules could then trap an Hg molecule through formation of a mercuric-chloride-like molecule. Significant correlations between Cl and Hg uptake by gypsum were noted.

1999-11-01

395

Role of HCl in adsorption of elemental mercury vapor by calcium-based sorbents. Report for September 1998--May 1999  

Energy Technology Data Exchange (ETDEWEB)

The paper gives results of a study to identify active sites and surface functional groups that may contribute to the absorption of elemental mercury (Hg) by relatively inexpensive calcium (Ca)-based sorbents. The study investigated the formation of chlorine (Cl) sites in CA-based sorbents as well as their role and reactivity in the absorption of Hg. HCl-exposed calcium sulfate dihydrate (gypsum) exhibited a superior Hg sorption capability. Crystalline water molecules on the surface of the gypsum were confirmed to contribute indirectly to Hg uptake. These surface molecules may have absorbed HC1 through hydrogen bond formation between an oxygen atom of a crystalline water molecule and a hydrogen atom of an HCl molecule. Two adjacent, physically absorbed HCl molecules could then trap an Hg molecule through formation of a mercuric-chloride-like molecule. Significant correlations between Cl and Hg uptake by gypsum were noted.

1999-01-01

396

Inhibition of calmodulin - regulated calcium pump activity in rat brain by toxaphene  

Energy Technology Data Exchange (ETDEWEB)

In vivo effects of toxaphene on calcium pump activity in rat brain synaptosomes was studied. Male Sprague-Dawley rats were dosed with toxaphene at 0,25,50, and 100 mg/kg/day for 3 days and sacrificed 24 h after last dose. Ca/sup 2 +/-ATPase activity and /sup 45/Ca uptake were determined in brain P/sub 2/ fraction. Toxaphene inhibited both Ca/sup 2 +/-ATPase activity and /sup 45/Ca/sup 2 +/ uptake and the inhibition was dose dependent. Both substrate and Ca/sup 2 +/ activation kinetics of Ca/sup 2 +/-ATPase indicated non-competitive type of inhibition as evidenced by decreased catalytic velocity but not enzyme-substrate affinity. The inhibited Ca/sup 2 +/-ATPase activity and Ca/sup 2 +/ uptake were restored to normal level by exogenously added calmodulin which increased both velocity and affinity. The inhibition of Ca/sup 2 +/-ATPase activity and Ca/sup 2 +/ uptake and restoration by calmodulin suggests that toxaphene may impair active calcium ...

1986-03-05

397

Inhibition of calmodulin - regulated calcium pump activity in rat brain by toxaphene  

International Nuclear Information System (INIS)

In vivo effects of toxaphene on calcium pump activity in rat brain synaptosomes was studied. Male Sprague-Dawley rats were dosed with toxaphene at 0,25,50, and 100 mg/kg/day for 3 days and sacrificed 24 h after last dose. Ca"2"+-ATPase activity and "4"5Ca uptake were determined in brain P_2 fraction. Toxaphene inhibited both Ca"2"+-ATPase activity and "4"5Ca"2"+ uptake and the inhibition was dose dependent. Both substrate and Ca"2"+ activation kinetics of Ca"2"+-ATPase indicated non-competitive type of inhibition as evidenced by decreased catalytic velocity but not enzyme-substrate affinity. The inhibited Ca"2"+-ATPase activity and Ca"2"+ uptake were restored to normal level by exogenously added calmodulin which increased both velocity and affinity. The inhibition of Ca"2"+-ATPase activity and Ca"2"+ uptake and restoration by calmodulin suggests that toxaphene may impair active calcium transport mechanisms by decreasing regulator protein ...

1986-04-13

398

Experimental investigation on denting in PWR steam generators: causes and corrective actions  

International Nuclear Information System (INIS)

Denting studies have been undertaken in order to assess the influence of the most important parameters which could initiate corrosion of the carbon steel occurring in the tube-tube support plate crevices of some PWR steam generators. Tests have been carried out in model boilers where feedwater was polluted with sea or river water. Specific effects of chloride or sulfate and influence of oxygen content, magnetite addition and pH value were investigated. In magnetite prepacked crevices, denting is obtained within 1000 hrs for seawater pollution of 0.3 ppm chloride at the blowdown. In neutral chloride or in river water, denting is observed only with oxygen addition. Denting prevention is effective in the case of an on-line addition of phosphate, boric acid, or calcium hydroxide. For denting stopping, boric acid or calcium hydroxide is efficient even with a high seawater pollution. Soaks cannot stop denting if they are not followed by an on-line ...

399

Experimental investigation on denting in PWR steam generators, causes and corrective actions  

International Nuclear Information System (INIS)

Denting studies have been undertaken in order to assess the influence of the most important parameters which could initiate corrosion of the carbon-steel occurring in the tube-tube support plate crevices of some PWR steam generators. Tests have been carried out in model boilers, feedwater being polluted with sea or river water. Specific effect of chloride or sulfate and influence of oxygen content, magnetite addition and pH value were investigated. In magnetite prepacked crevices, denting is obtained within 1000 hours for sea-water pollution of 0.3 ppm chloride at the blowdown. In neutral chloride or in river water denting is observed only with oxygen addition. Denting prevention is effective in the case of an on-line addition of phosphate, boric acid or calcium hydroxide. For denting stopping, boric acid or calcium hydroxide is efficient even with a high sea-water pollution. Soaks cannot stop denting if they are not followed by an on-line ...

1985-03-01

400

Crystallization fouling of calcium sulfate dihydrate on heat-transfer surfaces  

Energy Technology Data Exchange (ETDEWEB)

The present paper deals with the fouling process of calcium sulfate dehydrate on heat-transfer surfaces. The crystallization of calcium sulfate showed typical asymptotic fouling curves, the asymptotic value of which was greatly influenced by the surface temperature and fluid velocity. The fouling mechanism was discussed with a generalized fouling model and proved to be surface process controlled, where the activation energy was 6.2 {times} 10{sup 4} J/mol. The availability of mechanical cleaning against the formed scale was quantitatively evaluated by applying the particle abrasion method. The removal test verified that the removing rate per unit particle concentration decreased in an inverse proportion to the overall particle load, to the power of 0.8, and that it was affected by the fluid velocity. The observed final residual fouling resistance decreased asymptotically with an increase in particle concentration. The suitable concentration of ...

1996-02-01

401

Clear liquor scrubbing with anhydrite production. Fourth quarter 1996 technical progress report  

Energy Technology Data Exchange (ETDEWEB)

This project is part of PETC`s Advanced Power Systems Program, whose mission is to accelerate the commercialization of affordable, high- efficiency, low emission, coal-fueled electric generating technologies. A process concept - Clear Liquor Scrubbing with Anhydrite Production - was proposed and accepted by PETC as a Phase I project in its Mega-PRDA program. the project integrated three process operations - chloride control upstream of the flue gas desulfurization (FGD) system, a clear liquor process for enhanced SO{sub 2} removal performance, and production of anhydrite (anhydrous calcium sulfate) rather than calcium sulfite or gypsum (calcium sulfate dihydrate). The first step in the project was to perform batch and flow-through experiments in the laboratory to confirm theoretical calculations and preliminary laboratory results concerning anhydrite formation, these laboratory experiments were designed to prove that ...

1997-02-03

402

Calcium sulfate crystallization along citrus root channels in a Florida soil exhibiting acid sulfate properties  

Energy Technology Data Exchange (ETDEWEB)

The authors observed euhedral crystals in Manatee soil in a citrus grove in St. Lucie County, Florida. The material was identified as gypsum (CaSO/sub 4/ /times/ 2H/sub 2/O) using x-ray diffraction and infrared spectra. Photomicrography and scanning electron microscopy revealed that gypsum accumulated both in old root channels and within citrus root tissue of the Btg horizon. The subsurface horizons had elevated sulfate levels, a low initial pH, a drop (0.5 unit) in pH upon air-drying. Electrical conductivity paralleled the concentration of water-soluble sulfate. High levels of calcium and sulfate occurred for horizons above the water table. This accumulation is attributed to groundwater bearing these ions and subsequently discharging them to the overlying soil. Dead citrus roots appear to act as wicks to aid water transfer from lower to higher horizons. The roots and their empty channels provide spaces in which the gypsum can precipitate if the concentrations of ...

1988-02-01

403

An indicator, high speed method for determining the water and aqueous phase content in a hydrocarbon fuel  

Energy Technology Data Exchange (ETDEWEB)

A method and an instrument for determining the total water content in a hydrocarbon fuel using an indicator composition, which includes calcium hydride and phenolphthaleyn, are developed. The essence of the method is fixing the presence of water with its interaction with the calcium hydride and subsequent indication of the formed Ca(OH)2 using the phenolphthallen. To make the indicator composition, a hygroscopic cotton, prewashed by rectified alcohol and dried for 30 minutes at 105 degrees, is impregnated by a 1 percent alcohol solution of phenolphthaleyn and is dried in the same conditions. Then the cotton is processed by a powder form calcium hydride (a layer thickness of 0.1 to 0.2 millimeters, and a granule size of less than or equal to 80 micromters). The indicator composition is placed in a glass tube (a diameter of 4 to 7 millimeters and a length of 80 to 100 millimeters), whose ends are sealed or filled with ...

1983-01-01

404

Alternative calcium-sulfate-bearing materials as cement retarders: Part II. FGD gypsum  

Energy Technology Data Exchange (ETDEWEB)

The aim of this paper is to investigate the possible displacement of natural gypsum (CaSO{sub 4}2H{sub 2}O) in cement with an alternative setting retarder, such as the industrial by-product derived from flue gas desulfurization process called FGD gypsum. These calcium-sulfate-bearing materials (CSBM), alone or in mixtures, were ground with clinker both in laboratory and industrial scale to examine their influence on the physical and mechanical properties of cement, as well as on the industrial production line of cement. From the present work, it is extracted that the use of mixtures of sulfate-bearing materials with gypsum seems to be advantageous for the actual control of setting time. The addition of FGD gypsum increases setting time without affecting compressive strength profile. During the industrial trial, the formation of hemihydrate form of calcium sulfate dihydrate has a profound regulatory effect on the setting and strength performance ...

2004-11-01

405

Activation of fat cell adenylate cyclase by protein kinase C  

Energy Technology Data Exchange (ETDEWEB)

Purified protein kinase C (C-kinase) from guinea pig pancreas and rat brain stimulated adenylate cyclase activity in purified rat adipocyte membranes. Cyclase stimulation occurred over 100 to 1000 mU/ml of C-kinase activity, required greater than 10 ..mu..M calcium, proceeded without a lag, was not readily reversible, and required no exogenous phospholipid. Moreover, C-kinase inhibitors, such as chlorpromazine and palmitoyl carnitine, inhibited selectively adenylate cyclase which was activated by C-kinase and calcium. Depending on assay conditions, 10 nM 12-0-tetradecanoylphorbol-13-acetate (TPA) either enhanced or was required for kinase action on cyclase. Also, TPA plus calcium promoted the quantitative association of C-kinase with membranes. Adenylate cyclase activation by C-kinase was seen both in the presence and absence of exogenous GTP, indicating that the kinase effect does not result from an action on the ...

1986-05-01

406

Study on warm caliber rolling of magnesium alloy  

Energy Technology Data Exchange (ETDEWEB)

The warm caliber rolling was experimented using the AZ31 magnesium alloy round bar of 20 mm in diameter machined from cast ingot materials. In warm caliber rolling in final size of 10 mm in diameter at 623 K via 8passes, each width-spreading, the change of each microstructure, X-ray analysis of final texture and final mechanical properties were investigated. Microstructure, texture and mechanical properties of warm caliber rolled round bar at 473 K via latter 4passes were compared with those at 623 K consistently. Obtained results are as follows: (1) The width-spreading in caliber rolling of round bar is relatively large, compared with that in flat rolling of the flat bar. The largeness of width-spreading of round bar makes the shape control of cross section difficult, and causes the cracks around the free surface. (2) Finer microstructure and inclined c axis of hexagonal lattice of 10 degrees to vertical direction of the rolled surface are obtained in warm caliber ...

2003-07-01

407

Stearic acid gel derived MgTiO{sub 3} nanoparticles: A low temperature intermediate phase of Mg{sub 2}TiO{sub 4}  

Energy Technology Data Exchange (ETDEWEB)

Stearic acid gel is employed to study the phase evolution of MgTiO{sub 3} nanoparticles by thermal gravimetric analysis, X-ray diffraction, and Fourier transform infrared. During the preparation of stearic acid gel, tetrabutyl titanate easily absorbed moisture to hydrolyze into Ti(OH){sub 4} firstly, and then reacts with stearic acid and magnesium stearate to form magnesium-titanium oxide network polymer gel, meanwhile n-butanol is generated. When stearic acid gel is calcined in air, a series of oxidation and combustion reactions occur, meanwhile apparent heat is given off. The results show that a metastable intermediate phase Mg{sub 2}TiO{sub 4} is generated at 450 {sup o}C and nearly disappeared at 550 {sup o}C. Simultaneously, a new solid phase of MgTiO{sub 3} appears. The metastable intermediate phase Mg{sub 2}TiO{sub 4} is successfully identified in the current work.

2010-03-04

408

Research on deformation characteristic of AZ31Mg alloy and its constitutive equations  

Energy Technology Data Exchange (ETDEWEB)

Superplasticity of polycrystalline metallic materials is a phenomenon which shows hundreds to thousands of percents of large plastic deformation without necking in a steady state of low stress, when the uni-axial tensile loading is done in some special thermo-mechanical conditions (some limited ranges of properly high temperature and low strain rate). The main mechanism of superplastic phenomenon is the grain boundary sliding, while the main mechanism of usual plastic deformation is the trans-granular sliding. In this research, the possibility of superplastic deformation in a magnesium alloy (AZ31Mg alloy) was experimentally investigated, because generally speaking, the magnesium alloy whose atomic structure is hexagonal does not have enough formability in a form of trans-granular sliding mechanism. In this paper, the detail of experimental results are shown and discussed. Moreover, the constitutive equations of Mg alloy are proposed on the ...

2004-07-01

409

Recrystallization in AZ31 magnesium alloy during hot deformation  

Energy Technology Data Exchange (ETDEWEB)

In this study, isothermal torsion tests were carried out on magnesium AZ31B alloy under constant strain rate conditions, in the range of 250 to 400 C at 0.01, 0.1, and 1.0 s{sup -1}. Alloy flow stress dependence on strain rate and temperature can be described by a power law with activation energy of 130 kJ/mol. Microstructural examination of hot deformed samples shows very fine recrystallized grains decorating grain boundaries of larger gains in the form of a necklace. These fine grains are produced by dynamic recrystallization at the grain boundaries of original grains. Microstructure evolution, based on samples quenched at different strain levels, indicates that increasing deformation strain has little effect on recrystallized grain size but widens the recrystallized region, with full recrystallization achieved at a certain high strain level. Recrystallized grain size increases with increasing deformation temperature and strain rate. The latter suggests ...

2005-07-01

410

Oxidative dimerization of methane over lead-magnesium mixed oxide catalysts  

Energy Technology Data Exchange (ETDEWEB)

Our goal was a process to convert methane to higher hydrocarbons oxidatively, since this circumvents thermodynamic yield limits of a strictly degydrogenative process. Keller and Bhasin converted thermodynamic yield limits of a strictly dehydrogenative process. Keller and Bhasin converted methane to higher hydrocarbons by using metal oxides as oxidants, without co-fed oxygen. They stated that selectivity is necessarily poor if gaseous oxygen is present. Jones and Sofranko have also used reducible metal oxides as oxidants in a group of their parents, but later used some of those materials with continuous O{sub 2} feed without much loss of selectivity. Baerns, Lunsford and Otsuka have shown that high selectivity could be possible with co-fed O{sub 2} at least for low O{sub 2} partial pressures, over PbO-A1{sub 2}O{sub 3}, Li-MgO and rare earths. The performance of a group of multicomponent oxide catalysts, containing lead and magnesium oxides, for oxidative conversion ...

1987-08-01

411

On methods for improving the fatigue performance of the wrought magnesium alloys AZ31 and AZ80  

Energy Technology Data Exchange (ETDEWEB)

The tensile and compressive properties as well as LCF and HCF performance of the extruded magnesium alloys AZ31 and AZ80 were determined in extrusion (L) and long-transverse (T) directions. Owing to marked crystallographic textures, both alloys showed pronounced directional mechanical properties in monotonic as well as cyclic loading with strength values in L-direction being significantly superior to those in T-direction. Thermomechanical treatments such as pressing, swaging and rolling were found to increase yield stresses and HCF strengths and to alter the directionality in properties due to textural modifications. To further improve HCF strengths, mechanical surface treatments such as shot peening, roller-burnishing and deep rolling were utilized. The results indicate marked improvements provided that suitable process parameters are used. The improvement of the HCF strengths is explained by the process-induced changes in near-surface dislocation densities and ...

2003-07-01

412

Method for preparing drilling solutions that are resistant in Zechstein deposits  

Energy Technology Data Exchange (ETDEWEB)

The patent is for a method of preparing drilling muds that are notable for their chemical resistance to Zechstein deposits, especially to magnesium, carbonate and carboxylic acid ions. To achieve chemical resistance of the drilling mud to Zechstein deposits, it is suggested to saturate them with salt (the amount of added salt depends on the absorption properties of the solution), and then to process them with caustic soda or potassium oxide hydrate and lime in proportions that would cause filtrate alkalinity not to exceed 0.5. For example, to prepare drilling solution to bore through mediums containing magnesium salts, potassium salts, rock salt, anhydrate, dolomite, limestone, red salt clay: add 340 kg potassium chloride into 1 m/sup 3/ drilling solution with weighed bentonic clay, 10 kg. ferro-chromate lignosulfite, 7 kg. unslaked lime, 2 kg. sodium hydroxide, 5 kg. carboxy-methyl-cellulose, 5 kg. carboxy-methyl-hydroxylethyl-cellulose, 50 ...

1980-05-31

413

Influence of second phase particles on fracture toughness in AZ31 magnesium alloys  

Energy Technology Data Exchange (ETDEWEB)

Three kinds of thin AZ31 wrought magnesium alloys sheets were used in order to investigate the influence of the second phase particles on fracture toughness. From the theoretical model, the ratio of {lambda}{sub p}/d{sub p} would be estimated 5 {proportional_to} 6. On the other hand, from the microstructural observation, average particle spacing on each material was sample A: 13.1 {mu}m, sample B: 14.1, and sample C: 12 {mu}. In addition, average particle size on each sample was sample A: 2.1, sample B: 1.9, and sample C: 2.3 {mu}m. Therefore, the ratio of {lambda}{sub p}/d{sub p} calculated from fracture surface observation would be predicted 6 {proportional_to} 7. In comparison with the result of the prediction by theoretical analysis was in good agreement with the result of fracture toughness observation. It was found that the variation in plane-strain fracture toughness on AZ31 were affected by both of particle spacing and particle size. (orig.)

2004-07-01

414

Improvement in mechanical properties of magnesium alloy (AZ31) sheet fabricated by casting and subsequent plastic working  

Energy Technology Data Exchange (ETDEWEB)

In order to enhance the mechanical properties of magnesium alloy (AZ31) sheet, an integrated sheet-making process including billet casting, extrusion and rolling was attempted. Microstructural analysis was carried out and the mechanical properties at each processing step were also investigated by tensile tests. By an extrusion process of ingot-processed billet, average grain size of billet was reduced from 91.2 to 28.2 {mu}m, and a further reduction in grain size to 16.9 {mu}m was obtained by subsequent rolling of extruded 5 mm thin slab. In the final step, a rolled sheet of 1 mm showed a remarkable refinement in grain size down to 8.8 {mu}m. Regarding mechanical properties, tensile strength and elongation for as-cast billet, as-extruded thin slab and as-rolled sheet increased from 189, 258 to 234 MPa, and from 13, 16.5 to 23%, respectively. (orig.)

2003-07-01

415

Grain refinement in magnesium alloy AZ31 during hot deformation  

Energy Technology Data Exchange (ETDEWEB)

The deformation behavior and structure changes of magnesium alloy AZ31 were studied in compression at temperatures ranging from 523 K to 673 K and at a strain rate of 3 x 10{sup -3} s{sup -1}. They depend sensitively on deformation temperature. At high temperatures, grain fragmentation takes place due to frequent formation of kink bands initially at corrugated grain boundaries and then in grain interiors, followed by full development of new grains in high strain. At lower temperatures, in contrast, twinning takes place in rather coarse grains and kink bands are formed mainly in finer original ones in low strain. It is concluded that new grain evolution can be controlled by a deformation-induced continuous reaction resulting in grain fragmentation by kink bands, i.e. continuous dynamic recrystallization (cDRX). The latter is discussed comparing with conventional, i.e. discontinuous, DRX. (orig.)

2004-07-01

416

Enhancing compressive response of AZ31B using nano-Al2O3 and copper additions  

British Library Electronic Table of Contents (United Kingdom)

In the present study, new light weight nano-composites (AZ31B-3.3Al2O3-Cu) based on magnesium alloy AZ31B are developed using disintegrated melt deposition technique. Microstructural characterization studies revealed grain refinement and significant increase in amount of second phases as a result of increasing presence of copper. All the samples exhibited minimal porosity and good matrix-second phase interfacial integrity. The results also showed that addition of both nano-Al2O3 and Cu led to a simultaneous improvement in 0.2% yield compressive strength (0.2%YCS), ultimate compressive strength (UCS) and work of fracture (WoF) of the AZ31B magnesium alloy while failure strain was marginally affected. The results of this study clearly illustrate the capability of AZ31B-Al2O3-Cu formulations ...

2010-01-01

417

Effect of field natural rubber latex with different ammonia contents and storage period on physical properties of latex concentrate, stability of skim latex and dipped film  

British Library Electronic Table of Contents (United Kingdom)

The effect of ammonia treatment in field natural rubber (NR) latex with different storage period time on the properties of concentrated NR latex and stability of skim latex was investigated. Fresh NR latex was treated with various ammonia contents such as 0.35, 0.60 and 0.80% w/w, and then they were centrifuged to get the concentrated NR latex with 60% dry rubber content (DRC) containing 0.16, 0.18 and 0.25% w/w, respectively and skim NR latex with roughly 5% DRC containing 0.42, 0.60 and 0.80% w/w, respectively. The effect of storage times with ?0, 15, 30 and 45 days for concentrated NR latex with different ammonia contents on their properties such as alkalinity, magnesium content and viscosity was observed. It was found that generally, magnesium content in field NR latex and latex...

2009-01-01

418

Dynamic nucleation of new grains in magnesium alloy during hot deformation  

Energy Technology Data Exchange (ETDEWEB)

Microstructure evolution under hot deformation was investigated in compression of a magnesium alloy AZ31 at 673 K (0.73T{sub m}). Two kinds of samples were machined along the parallel and transverse direction of the extruded rods. New fine grains are evolved at corrugated grain boundaries at low strains and developed rapidly in grain interiors in the medium range of strain, finally leading to a roughly full evolution of equiaxial fine grains. Kink bands are evolved at corrugated grain boundaries and in grain interiors at low strains. The boundary misorientation of kink band increases rapidly with increasing strain. These characteristics of new grain evolution process are not changed by the orientation of the samples, while the flow behaviors clearly depend on it. It is concluded that new grain evolution can be controlled by a deformation-induced continuous reaction resulting in grain fragmentation by kink bands, i.e. continuous dynamic recrystallization (DRX). The ...

2003-07-01

419

Anisotropy of tensile properties of extruded magnesium alloy AZ31  

Energy Technology Data Exchange (ETDEWEB)

The mechanical behaviour of wrought magnesium alloy AZ31 has been characterised by tensile testing at room temperature. Tests were carried out at various strain rates between 0.00003 s{sup -1} and 0.01 s{sup -1} on material which had been extruded to a bar of approximately 6 mm thick, and 80 mm wide. Specimens were machined from three orientations relative to the extrusion direction: parallel, perpendicular, and 45 from the extrusion direction. Significant variations of the properties were observed depending on the extrusion orientation and strain rate. At all strain rates the yield stress declined as the test orientation was rotated away from the extrusion direction. Parallel to the extrusion direction, the yield stress was found to increases markedly with increasing strain rate, whereas at 45 and 90 a lesser influence of strain rate was observed. The work hardening exponent was also influenced by the test orientation. Metallographic studies revealed a ...

2003-07-01

420

Texture development of AZ31 magnesium alloy during ECAE processing  

Energy Technology Data Exchange (ETDEWEB)

Mg-3%Al-1%Zn (AZ31) alloy was subjected to ECAE processing at 523 and 573 K. Microstructure observation and texture analysis were carried out using optical microscope and SEM-EBSD technique in order to investigate the process of microstructural changes including texture development during ECAE processing. Grain refinement during ECAE processing is enhanced by dynamic continuous recrystallization. The texture of the ECAE-processed AZ31 alloy specimens change with ECAE processing temperature, and the textural changes relate to deformation mechanisms that change with ECAE processing temperature. (orig.)

2003-07-01

421

Flue gas desulfurization system capabilities for coal-fired steam generators. Volume II. Technical report. Final task report apr-dec 77  

Science.gov (United States)

The availability of technology for reducing SO2 emissions from coal-fired steam generators using flue gas desulfurization (FGD) systems is discussed. Foreign and domestic lime, limestone, double alkali, magnesium slurry, and Wellman-Lord FGD systems are described, and the design parameters and operating experiences are discussed. Steps that have been taken to achieve high system operability are discussed. Also, disposal of FGD system wastes is discussed briefly.

1978-03-01

422

FFTF reactor immersion heaters. Revision 1  

Energy Technology Data Exchange (ETDEWEB)

This specification establishes requirements for design, testing, and quality assurance for electric heaters that will be used to maintain primary Sodium temperature in the Fast Test Facility (FFTF) reactor vessel. The Test Specification (WHC-SD-FF-SDS-003) has been revised to Rev. 1. This change modifies the fabrication of approximately 25 feet of the subject heater using ceramic insulators over the heater lead wire rather than compressed magnesium oxide. Also, 304 or 316 stainless steel can be used for the heater sheath. This change should simplify fabrication and improve the heater operational reliability.

1994-08-26

423

Continuous wave operation (77 K) of yellow (583. 6 nm) emitting AlGaInP double heterostructure laser diodes  

Science.gov (United States)

Continuous wave lasing operation with the shortest wavelength for semiconductor lasers was obtained from AlGaInP double heterostructure lasers at 77 K. The structure was grown by metalorganic vapor phase epitaxy. Lasing wavelength was 583.6 nm (yellow). Threshold current was 43 mA (1.9 kA/cm/sup 2/). Magnesium was adopted as a p-type dopant, and was proved to be preferable for a high aluminum composition AlGaInP cladding layer.

1986-03-03

424

Adsorption properties of. cap alpha. -modification of boron nitride  

Science.gov (United States)

The adsorption properties of four samples of ..cap alpha..-BN were studied by means of gas chromatography. The particles of ..cap alpha..-BN particles, according to data obtained by electron microscopy, have the shape of thin platelets. A sample of ..cap alpha..-BN prepared from magnesium polyboride was found to be the most nearly homogeneous adsorbent. For a number of n-alkanes, benzene, and alkylbenzenes, data have been obtained on the retention volumes (Henry constants) and the differential heats of adsorption for surface coverages approaching zero. These thermodynamic data on the adsorption showed that ..cap alpha..-BN, like graphitized thermal carbon black, is a nonspecific adsorbent.

1986-11-01

425

Adsorption properties of #alpha#-modification of boron nitride  

International Nuclear Information System (INIS)

The adsorption properties of four samples of the #alpha#-modification of boron nitride (#alpha#-BN) were investigated by the gas-chromatographic method. According to the electron microscopy data, the #alpha#-BN particles possess the shape of thin plates. An #alpha#-BN sample prepared from magnesium polyboride, is the most uniform adsorbent. For a series of n-alkanes, benzene, and alkyl benzenes, by testing the #alpha#-BN samples one has obtained the retained volumes (Henry constants) and the values of the differential adsorption heat, which are close to those of the surface zero filling. These thermodynamic characteristics of adsorption have shown that the #alpha#-BN, line the graphitized thermal carbon black, is not a specific adsorbent.

426

Adsorption of ammonia and pyridine on copper(II)-doped magnesium-exchanged smectite clays studied by electron spin resonance  

Science.gov (United States)

The interaction between N-donor adsorbates such as ammonia and pyridine with Cu(II)-exchanged montmorillonite, beidellite, flourohectorite into smectite clays has been studied by electron spin resonance. Cu(II) cations exchanged into smectites coordinate five ammonia or pyridine molecules in beidellite, four ammonia of pyridine molecules in hydroxyhectorite. Thus, the Cu(II) cations bound to the interior surfaces of these smectite clays constitute strong Lewis acid sites. 26 refs., 7 figs., 1 tab.

1993-01-14

427

Technical-economic aspects of the utilization of geothermal waters  

International Nuclear Information System (INIS)

A brief description is given of the physico-chemical parameters characterized a hot water geothermal reservoir and of its exploitation by means of single or coupled (doublet) wells. The technical aspects of geothermal heat to the users is then discussed, beginning with corrosion of materials caused by seven main agents: oxygen, hydrogen sulphide, carbon dioxide, ammonia, hydrogen, sulphates and chlorides. A brief mention is made of scaling due to calcium carbonate, silica and calcium sulphates. The basic components of a geothermal plant for non-electric uses are then discussed: production pumps, surface pipelines, heat exchangers, heat pumps and reinjection pumps. The advantages and disadvantages of the different equipment and materials used in the geothermal sector are also presented. A list is also given of the criteria used in the energy and economic balance of a geothermal operation. (author). 24 refs, 13 figs, 2 tabs.

428

Studies on the chemical composition and possible mechanisms underlying the antispasmodic and bronchodilatory activities of the essential oil of Artemisia maritima L.  

British Library Electronic Table of Contents (United Kingdom)

This study describes the chemical composition of the essential oil of Artemisia maritima (Am.Oil) and the pharmacological basis for its medicinal use in gut and airways disorders. Twenty five compounds, composing 93.7% of the oil, were identified; among these, chrysanthenyl propionate and elixene were identified for the first time from any Artemisia species. The Am.Oil (0.3?1.0 mg/mL) suppressed spontaneous and high K+ (80 mM)-induced contractions in isolated rabbit jejunum, suggestive of an antispasmodic effect mediated possibly through calcium channel blockade. The calcium channel blockade activity was confirmed when pre-treatment of the tissue with Am.Oil (0.01?0.03 mg/mL) shifted the Ca++ concentration-response curves to the right, similar to verapamil and papaverine. In isolated trach...

2011-01-01

429

Sterilization of male stray dogs with a single intratesticular injection of calcium chloride: a dose-dependent study  

British Library Electronic Table of Contents (United Kingdom)

ObjectiveTo study a method of chemical sterilization and its efficacy in adult male stray dogs.MethodsSterilization was performed 45 days after a single bilateral intratesticular injection of calcium chloride (CaCl2) at the doses of 5, 10, 15 or 20 mg per testis per kg body weight.ResultsHistomorphological measures of testes showed total necrosis of testicular tissue at 45 days after an injection of either 10 or 15 or 20 mg CaCl2 along with fibrosis and hyalinization in seminiferous tubules and interstitial spaces. Infiltration of leucocytes was also observed with the 10- or 15-mg dose. Disintegration of germ cell arrangement in seminiferous tubules and washing out of germ cells from the tubules were noted with the 5-mg dose. Relative organ weight, epididymal sperm count, plasma and intrat...

2007-01-01

430

Scale prevention with special reference to threshold treatment  

Energy Technology Data Exchange (ETDEWEB)

Various chemical, physical, and mechanical methods to prevent unwanted deposition of mineral scale are described. The suitability of the different methods, which largely depends on the specific features and requirements of the system involved, is discussed. Special emphasis is placed upon the threshold treatment, where the growth process is retarded by the addition of trace amounts of growth inhibitors. Growth experiments have been performed on barium sulfate and calcium sulfate dihydrate seed crystals, suspended in a supersaturated solution with and without organic bisphosphonates as inhibitors. Two methods are selected for the analysis of the growth data. A degree of inhibition is defined to obtain a quantitative description of the influence of a growth inhibitor on the growth rate of the crystals. In addition the influence of the molecular structure of various bisphosphonates with different substituents is shown. The effect of a bisphosphonate on the geometry of ...

1983-01-01

431

NEW SLAG-BASED CONCRETES  

Environmental Research Database

ObjectivesTo determine the reaction rate of slag during curing and factors affecting reactivity.~%~~%~To measure the rates of chloride ingress into concrete and the extent of chloride binding.~%~~%~To determine conditions for pitting corrosion and the nature of corrosion products.~%~~%~To characterise the reactions in slag-calcium alumina cement hydration and the nature of the products.~%~DescriptionBlast-furnace slag has latent hydraulic properties, giving considerable potential for commercial use in addition to its widespread use as a partial replacement for Portland cement, notably in alkali-activated slag (AAS) and slag-calcium alumina cement (CAC) concretes. Use of AAS concretes is already well-established in China and the former USSR, but their further application is hindered by lack of research into setting, hydration and durability, Slag/CAC blends are new materials whose chemistr ...

1999-01-09

432

Jump in the air gasification rate of potassium-doped cellulosic chars  

Energy Technology Data Exchange (ETDEWEB)

Chars prepared from potassium-exchanged carboxy methyl cellulose at several heat treatment temperatures (HTTs) were gasified in air isothermally at selected gasification temperatures (GTs) in the range 633-893 K to investigate the catalytic effectiveness of potassium species. The chars displayed a noticeable jump in gasification rate at a particular gasification temperature (called jump temperature, T{sub j}). The magnitude of jump was much less than that reported for copper and nickel catalysis, but comparable with that for calcium catalysis. Increase in HTT caused a decrease in the jump temperature of chars in contrast with the increase observed in copper, nickel and calcium catalysis; also the magnitude of jump did not decrease, but remained unaltered, on increasing HTT. The different behavior of potassium catalysis is correlated to a change in the chemical state of potassium at higher HTT. The results reveal the dependence of jump ...

2010-12-15

433

Intermediate-conductance calcium-activated potassium channels participate in neurovascular coupling  

British Library Electronic Table of Contents (United Kingdom)

BACKGROUND AND PURPOSE Controlling vascular tone involves K+ efflux through endothelial cell small- and intermediate-conductance calcium-activated potassium channels (KCa2.3 and KCa3.1, respectively). We investigated the expression of these channels in astrocytes and the possibility that, by a similar mechanism, they might contribute to neurovascular coupling. EXPERIMENTAL APPROACH Transgenic mice expressing enhanced green fluorescent protein (eGFP) in astrocytes were used to assess KCa2.3 and KCa3.1 expression by immunohistochemistry and RT-PCR. KCa currents in eGFP-positive astrocytes were determined in situ using whole-cell patch clamp electrophysiology. The contribution of KCa3.1 to neurovascular coupling was investigated in pharmacological experiments using electrical field stimulatio...

2011-01-01

434

Interaction studies between Crofer-22APU alloy and P2O5 containing barium calcium alumino-borosilicate (BCABS) sealant glass-ceramics  

International Nuclear Information System (INIS)

We present the effect of P2O5 addition on barium calcium aluminum borosilicate BCABS glasses of composition (mol %) 35BaO-15CaO-5Al2O3-(37-x)SiO2-8B2O3-xP2O5 (0?x?5). The incorporation of P2O5 increased network polymerization and crystallization tendency. However, addition of P2O5 leads to the formation of Cr2O3 at the interface, saturating it in the ions of the metal. This improves glass-to-metal bonding. (author)

2010-09-01

435

Calcium phosphate glass-ceramics for bioactive coating on a #beta#-titanium alloy  

International Nuclear Information System (INIS)

The formation of a porous coating is the decisive feature for the bio-compatibility of silica-free calcium phosphate glass ceramics on alloy surfaces like the #beta#-Ti structured Ti-29Nb-13Ta-4.6Zr used in this work. The ceramic composition is highly important: 50CaO-40P_2O_5-7Na_2O-3TiO_2 glass powder produces a pore-free coating unable to bind hydroxyapatite, whereas 60CaO-30P_2O_5-7Na_2O-3TiO_2 glass incorporates pores from which a crystalline hydroxyapatite phase can grow over the surface from simulated body fluid (see Figure). (Abstract Copyright [2003], Wiley Periodicals, Inc.)

2003-07-01

436

Acid-site distribution on Faujasite-type zeolites determined by n-butylamine titration--1. Comparison of the use of hammett and arylmethanol indicators on zeolites X  

Energy Technology Data Exchange (ETDEWEB)

The combined Lewis and Broensted acidities were measured of 13X (sodium) zeolite and of its 84.2% calcium-exchanged, 86.0% lanthanum-exchanged, and 69.2% protonated forms, calcined at 400/sup 0/C. The butylamine titrations were performed to visible color changes of Hammett indicators. The H/sub 0/ acidities were 0 for the sodium X zeolite, and 0.2, 0.98, and 0.75 for the calcium, lanthanum, and hydrogen zeolites, respectively. These acidities compared well with trends reported in literature for zeolites pretreated under different conditions. Titration of Broensted sites with arylmethanol indicators did not give satisfactory visible endpoints.

1980-05-29

437

A prospective randomised open label study to evaluate the potential of a new silver alginate/carboxymethylcellulose antimicrobial wound dressing to promote wound healing  

British Library Electronic Table of Contents (United Kingdom)

The aim of this study was to observe both the clinical signs and symptoms of wounds at risk of infection, that is critically colonised (biofilm infected) and antimicrobial-performance of an ionic silver alginate/carboxymethylcellulose (SACMC) dressing, in comparison with a non silver calcium alginate fibre (AF) dressing, on chronic venous leg and pressure ulcers. Thirty-six patients with venous or pressure ulcers, considered clinically to be critically colonised (biofilm infected), were randomly chosen to receive either an SACMC dressing or a non silver calcium AF dressing. The efficacy of each wound dressing was evaluated over a 4-week period. The primary study endpoints were prevention of infection and progression to wound healing. The SACMC group showed a statistically significant (P = ...

2010-01-01

438

Severity of iron deficiency anemia and its relationship to growth and morbidity  

Energy Technology Data Exchange (ETDEWEB)

The relationships between severity of iron deficiency anemia, response to iron treatment, respiratory and gastrointestinal illness and weight changes were assessed before (T1) and after (T2) iron therapy. Seventy-five pre-school children from rural Guatemala received daily oral iron (ferrous sulfate 5 mg/kg/day) for eleven weeks, and were classified into one of three groups: (1) severe iron deficient (Hgb < 9.25 g/dl at T1 and > 1g/dl Hgb response (T2-T1) to Fe Rx; (2) moderately iron deficient (Hgb 9.25 g/dl to 11.5 g/dl and T2-T1 > 1g/dl); (3) normal controls (Hgb > 11.5 g/dl and T2-T1 < 1g/dl). When both severely and moderately anemic children were pooled together, there was a statistical significant difference between the number of days ill with gastrointestinal symptoms of these children and those in the control group. Children with T1 Hgb ...

1986-03-01

439

Serum ferritin in recurrent oral ulceration  

Energy Technology Data Exchange (ETDEWEB)

A sensitive radio-assay for ferritin was developed and used to examine serum ferritin levels in 105 patients with recurrent oral ulceration (ROU), 41 patients with Behcet's syndrome (BS), 42 with other ulcerative oral lesions, 35 patients with non-ulcerative oral lesions and in 78 controls. Ferritin levels increased with age and were significantly higher in males than females. The mean ferritin concentrations in male patients with ROU, BS or with other oral ulcers were significantly reduced in comparison with controls, and in female patients were significantly reduced in those with major aphthous ulcers. The prevalence of low serum ferritin levels was about 8% in patients with ROU, 15% in BS and 9.5% in patients with other ulcerative oral lesions, compared with less than 3% in patients with non-ulcerative oral disorders and in controls. Most of the iron-deficient patients were female. Serum ferritin levels did not directly correlate with serum ...

1983-01-01

440

Role of iron in dry coal hydroconversion  

Energy Technology Data Exchange (ETDEWEB)

The behaviour of two different catalytic precursors based on iron (FeSO{sub 4}.7H{sub 2}O) and Fe{sub 2}O{sub 3} in direct hydroconversion of two coals are studied in this paper. Coal itself was the catalytic support of the dispersed iron sulfide (from iron sulfate); when the catalyst precursor was iron oxide (from red mud), coal and catalyst were directly mixed as powders. The reaction conditions were: 10 MPa (H{sub 2}, cold) initial pressure, 30 min, and reaction temperatures of 300, 350, 400, and 425{degree}C, reaching 450 and 500{degree}C for the high-rank coal. The results from Moessbauer spectroscopy demonstrate that pyrite in all the runs, inherent to coal or added as catalyst precursor, is converted into pyrrhotite to a variable extent according to the previous iron distribution and the iron chemical state in the catalyst precursors as well as the CS{sub ...

1995-09-01

441

The basic experiment on the high-temperature chemical reaction between sodium compound and iron-base material. Pt. 2. Structure observations  

Energy Technology Data Exchange (ETDEWEB)

This experiment is carried out in the series of the investigation on the damage mechanism of carbon steel. In this paper, the damage situation is considered by structure observations. The test were carried out in 600degC-1200degC temperature range, in blowing an argon gas. The reagents are Na{sub 2}O, Na{sub 2}O{sub 2} and NaOH. From structure observations, the holes are observed on the surface of iron-base material in some test conditions. This result is indicated that the selective reaction occurs. The selective reaction is more obvious as the time exposed to the high temperature is longer. It is considered that the selective reaction occurs after the chemical reaction between iron-base material and sodium compound. The areas, in which Mn-concentration is higher, are observed in products on the surface of specimen. (author)

1997-07-01

442

Synthesis of magnetic particles via a cationic-anionic surfactant vesicle method  

Energy Technology Data Exchange (ETDEWEB)

In this work, a mixed cationic--anionic [i.e. cetyltrimethylammonium bromide-sodium octyl sulphate] surfactant system was used to synthesize the magnetite particles. The loading content of iron ions (Fe{sup 3+} and Fe{sup 2+}) into the surfactant system was varied to study its effect on the formation of magnetite, magnetic and morphological properties of the magnetite particles encapsulated by the surfactant vesicles. It has been verified that the vesicle-encapsulated magnetite particles with sizes from 100 to 200 nm were formed, which were almost independent of the loading content of iron ions. However, the morphological structure of the magnetite particles was dependent on the loading content of iron ions and there existed an optimal loading content for a full packing of the surfactant vesicles with the magnetite particles.

2006-10-15

443

Synthesis of magnetic particles via a cationic-anionic surfactant vesicle method  

International Nuclear Information System (INIS)

In this work, a mixed cationic--anionic [i.e. cetyltrimethylammonium bromide-sodium octyl sulphate] surfactant system was used to synthesize the magnetite particles. The loading content of iron ions (Fe"3"+ and Fe"2"+) into the surfactant system was varied to study its effect on the formation of magnetite, magnetic and morphological properties of the magnetite particles encapsulated by the surfactant vesicles. It has been verified that the vesicle-encapsulated magnetite particles with sizes from 100 to 200 nm were formed, which were almost independent of the loading content of iron ions. However, the morphological structure of the magnetite particles was dependent on the loading content of iron ions and there existed an optimal loading content for a full packing of the surfactant vesicles with the magnetite particles.

2006-10-01

444

Surface modification of the pure iron by the pulse plasma nitriding: Application of a kinetic model  

Energy Technology Data Exchange (ETDEWEB)

In this work, the pulse plasma nitriding process of pure iron is modelled using a kinetic model derived from the Fick's laws. This approach based on the error function model allows to simulate the growth kinetics of a biphase configuration consisting of {gamma}'-Fe{sub 4}N{sub 1-x} and {epsilon}-Fe{sub 2-3}N iron nitrides under specified conditions. By coupling the kinetics data about the diffusivities of nitrogen in {alpha}-Fe, {gamma}' and {epsilon} phases to the thermodynamic description of the Fe-N phase diagram, it is possible to evaluate the kinetic constant at each growing phase interface, the thickness of nitrided layer, and predict the nitrogen concentration profiles. The comparison between the experimental and theoretical results shows the reliability of the simulation results.

2007-07-25

445

Surface modification of the pure iron by the pulse plasma nitriding: Application of a kinetic model  

International Nuclear Information System (INIS)

In this work, the pulse plasma nitriding process of pure iron is modelled using a kinetic model derived from the Fick's laws. This approach based on the error function model allows to simulate the growth kinetics of a biphase configuration consisting of #gamma#'-Fe_4N_1_-_x and #epsilon#-Fe_2_-_3N iron nitrides under specified conditions. By coupling the kinetics data about the diffusivities of nitrogen in #alpha#-Fe, #gamma#' and #epsilon# phases to the thermodynamic description of the Fe-N phase diagram, it is possible to evaluate the kinetic constant at each growing phase interface, the thickness of nitrided layer, and predict the nitrogen concentration profiles. The comparison between the experimental and theoretical results shows the reliability of the simulation results.

2007-07-25

446

Stellar Pollution in the Solar Neighborhood  

CERN Document Server

We study spectroscopically determined iron abundances of 642 solar-type stars to search for the signature of accreted iron-rich material. We find that the metallicity [Fe/H] of a subset of 466 main sequence stars, when plotted as a function of stellar mass, mimics the pattern seen in lithium abundances in open clusters. Using Monte Carlo models we find that, on average, these stars have accreted about 0.4 Earth masses of iron while on the main sequence. A much smaller sample of 19 stars in the Hertzsprung gap, which are slightly evolved and whose convection zones are significantly more massive, have lower average [Fe/H], and their metallicity shows no clear variation with stellar mass. These findings suggest that terrestrial-type material is common around solar type stars.

2000-01-01

447

Passivity of iron in red mud's water solutions  

International Nuclear Information System (INIS)

Red mud suspensions are studied as passivating agents for iron in alkaline chloride media. Red mud particles in alkaline media are negatively charged, and can absorb considerable amounts of protons without significant changes in pH. These particles adhere easily to an iron surface forming aggregates of heterogeneous shape, smaller than 10 #mu#mx10 #mu#m. These adhered particles recrystallise on potential cycling, and hinder metal dissolution and magnetite formation. Carbon steel samples passivated in red mud suspensions become resistant to corrosion in alkaline chloride media. Corrosion potential versus time records and impedance spectroscopy measurements allow formulating some hypotheses about the inhibiting mechanism.

2004-07-30

448

Passivity of iron in red mud's water solutions  

Energy Technology Data Exchange (ETDEWEB)

Red mud suspensions are studied as passivating agents for iron in alkaline chloride media. Red mud particles in alkaline media are negatively charged, and can absorb considerable amounts of protons without significant changes in pH. These particles adhere easily to an iron surface forming aggregates of heterogeneous shape, smaller than 10 {mu}mx10 {mu}m. These adhered particles recrystallise on potential cycling, and hinder metal dissolution and magnetite formation. Carbon steel samples passivated in red mud suspensions become resistant to corrosion in alkaline chloride media. Corrosion potential versus time records and impedance spectroscopy measurements allow formulating some hypotheses about the inhibiting mechanism.

2004-07-30

449

Moessbauer spectroscopic determination of chemical state of iron in bauxite  

International Nuclear Information System (INIS)

The chemical state of iron contained in several kinds of bauxite, which are utilized as a raw material in the aluminum industry in Japan, were investigated by Moessbauer spectroscopy. The main compounds of iron were identified from the results, which showed variations of the Moessbauer absorption spectra with calcination and measuring temperature. Although the absorption intensities of the spectra differed significantly, major species identified were paramagnetic or superparamagnetic #alpha#-Fe_2O_3 in all of these bauxite samples. The superparamagnetic #alpha#-Fe_2O_3 was found mainly in the gibbsite-type bauxite, but not in the boehmite/gibbsite-type or the boehmite-type bauxite. The Moessbauer absorption spectra of red mud and its calcined products were also given. (author).

450

Influence of organic additives on the corrosion of iron-based amorphous alloys in dilute sulfuric acid solution  

Energy Technology Data Exchange (ETDEWEB)

Some N-containing or S-containing organic substances and some acetylenic alcohols were tested as inhibitors of the corrosive attack suffered by Fe-based metallic glasses in deaerated 0.1 N sulfuric acid (H{sub 2}SO{sub 4}) solution at 25 C. It was verified that the specific action these compounds exerted on the corrosion process of the amorphous alloys was similar to the one these compounds exerted on polycrystalline iron. The most efficient substances were those containing a sulfur atom with available lone pairs, which chiefly inhibited the anodic reaction of both metal specimens. Owing to the chemical and physical homogeneity of the amorphous alloy, the chemisorbed inhibitor film that formed on the glassy surface was more stable and protective than that formed on the polycrystalline iron.

1999-07-01

451

Ferrihydrite phase transformation in the presence of aqueous sulfide and supercritical CO2  

British Library Electronic Table of Contents (United Kingdom)

The transformation of ferrihydrite to siderite (FeCO3) in the presence of supercritical CO2 (scCO2) and aqueous sulfide has been investigated by in situ attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and ex situ X-ray diffraction (XRD). The chemical transformation of iron-bearing minerals to form iron carbonates may play a role in the chemistry related to the geological sequestration of carbon dioxide in the Earth's (sub)surface. The iron oxyhydroxide ferrihydrite in an aqueous solution containing sodium sulfide in contact with scCO2 at 100^oC reacts within 24h to form siderite and elemental sulfur. In situ studies of this reaction with ATR-FTIR show that ferrihydrite exists with an adsorbed layer of carbonate. However, the presence of the carbonate adsorbat...

2010-01-01

452

Estimation and characterization of PCDD/Fs and dioxin-like PCBs from Chinese iron foundries  

British Library Electronic Table of Contents (United Kingdom)

The iron foundry industry is considered to be a potential source of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). This study investigated the emission factors and total emission amounts of PCDD/Fs and dioxin-like polychlorinated biphenyls (DL-PCBs) from iron foundries in China. The concentrations and the World Health Organization toxicity equivalents (WHO-TEQs) are presented and the congener profiles are discussed in this paper. In the present work, 26 fly ash samples were collected and tested to quantify the PCDD/Fs and DL-PCBs generated by 14 plants of different scales, and five stack gas samples were collected from two (named as EFG and LFG) of those plants. The emission levels of PCDD/Fs and DL-PCBs indicated that hot-air cupolas had lower emissions than cold-air cupol...

2011-01-01

453

Adhesive wear of iron chromium nickel silicon manganese molybdenum niobium alloys with duplex structure. Untersuchung von Eisen-Chrom-Nickel-Silizium-Mangan-Molybdaen-Niob-Legierungen mit Duplexgefuege auf adhaesiven Verschleiss  

Energy Technology Data Exchange (ETDEWEB)

Iron nickel chromium manganese silicon and iron chromium nickel manganese silicon molybdenum niobium alloys have a so-called duplex structure in a wide concentration range. This causes an excellent resistance to wear superior in the case of adhesive stress with optimized concentrations of manganese, silicon, molybdenum and niobium. The materials can be used for welded armouring structures wherever cobalt and boron-containing alloy systems are not permissible, e.g. in nuclear science. Within the framework of pre-investigations for manufacturing of filling wire electrodes, cast test pieces were set up with duplex structure, and their wear behavior was examined. (orig.).

1991-11-01

454

Use of Eu"3"+ as an oxygen environment probe in alkali-alkaline earth-lanthanide phosphates with the #beta#-K_2SO_4 structure  

International Nuclear Information System (INIS)

The use of europium as a local structural probe allows the various phases appearing in the NaCaPO_4-Na_3Eu(PO_4)_2 and NaSrPO_4-Na_3Eu(PO_4)_2 systems to be detected. The broadening of the europium emission lines in going from the calcium to the strontium phases illustrates the ease of displacement of the PO_4 groups. (Auth.).

1983-09-01

455

The relation between net calcium, alkali cation and chloride movements in red cells exposed to salicylate.  

UK PubMed Central (United Kingdom)

1. From a 150 mM-NH4 salicylate medium salicylate enters human red cells with a rate constant of 1.9 min-1 at 0 degrees C. 2. Salicylate increases the red cell permeability for Ca2+ (and Mg2+). There...Full Text Available

1979-02-01

456

Simultaneous lowering of serum phosphate and LDL-cholesterol by sevelamer hydrochloride (RenaGel) in dialysis patients.  

Science.gov (United States)

The aim of the current investigation was to study the effects of sevelamer hydrochloride (RenaGel) on serum phosphate, intact parathyroid hormone levels (iPTH), and lipid profiles in stable hemodialysis patients. Hemodialysis patients maintained on calcium containing phosphate binders were enrolled in this study. Following two weeks of washout of the phosphate binders, serum phosphate rose from 6.4 +/- 0.6 to 10.5 +/- 0.7 mg/dl (p <0.001). After 8 weeks of titration with sevelamer hydrochloride, serum phosphate fell by 4.5 +/- 0.3 to 6.3 +/- 0.7 mg/dl (p <0.0001). Serum calcium levels fell during washout (9.8 +/- 0.4 to 8.9 +/- 0.3 mg/dl, p <0.004) and were unaffected by sevelamer hydrochloride. Sevelamer hydrochloride administration was associated with a 23.0 +/- 3.1% fall in total cholesterol, a 35.9 +/- 3.0% fall in LDL cholesterol, and a 35.2 +/- 5.3% fall in the LDL:HDL cholesterol ratio (p <0.001). There was no change in HDL ...

1998-12-01

457

Roles of mitochondria and temperature in the control of intracellular calcium in adult rat sensory neurons  

UK PubMed Central (United Kingdom)

SUMMARYWe recorded Ca2+ current and intracellular Ca2+ ([Ca2+]i) in isolated adult rat dorsal root ganglion (DRG) neurons at 20 and...Full Text Available

2008-04-01

458

Research on the liquefaction of lignite by hydrogenation  

Energy Technology Data Exchange (ETDEWEB)

The investigations of lignite hydroliquefaction were aimed at improving reaction control in order to minimize residue and gas portion and hence increase the oil yield. To reach this goal, the process parameters were optimized and various catalysts tested for use in sump phase hydrogenation. Detailed investigations were also carried out on the problem of calcium carbonate agglomeration and the maceral decomposition behaviour of different lignite samples under hydrogenation conditions.

1985-01-01

459

Radioactive lead studies in the human  

International Nuclear Information System (INIS)

The differing susceptibility of individuals to the toxic effects of chronic lead exposure has never been fully understood. As the major intake of lead in the human is from food and beverages, any variation between individuals of the quantity of lead absorbed from the gut, and of the distribution and excretion of this lead, may account for the differences in individual susceptibility. The food and beverages themselves may have an influence, and to investigate their effects on absorption, distribution and excretion of lead, experiments were performed on normal subjects using a short lived radionuclide of lead, "2"0"3Pb, and instruments generally available in Nuclear Medicine. Lead absorption between different individuals showed a wide variation when "2"0"3Pb was taken as a single dose between meals. Minerals were found to be mainly responsible for affecting absorption when one subject ingested "2"0"3Pb in control meals from which one dietary constituent at a time was omitted. ...

460

Photolysis of the novel inotropes EMD 57033 and EMD 57439: evidence that Ca2+ sensitization and phosphodiesterase inhibition depend upon the same enantiomeric site.  

UK PubMed Central (United Kingdom)

1. We studied the effects of flash photolysis on the novel enantiomeric cardiac inotropes EMD 57033 (a calcium sensitizer) and EMD 57439 (a phosphodiesterase III inhibitor) in rat isolated ventricular...Full Text Available

1996-08-01

461

Perlinhibin, a Cysteine-, Histidine-, and Arginine-Rich Miniprotein from Abalone (Haliotis laevigata) Nacre, Inhibits In Vitro Calcium Carbonate Crystallization  

UK PubMed Central (United Kingdom)

We have isolated a 4.785 Da protein from the nacreous layer of the sea snail Haliotis laevigata (greenlip abalone) shell after demineralization with acetic acid. The sequence of 41...Full Text Available

2007-08-15

462

Pathophysiology of incomplete renal tubular acidosis in recurrent renal stone formers: evidence of disturbed calcium, bone and citrate metabolism  

DEFF Research Database (Denmark)

Urinary acidification, bone metabolism and urinary excretion of calcium and citrate were evaluated in 10 recurrent stone formers with incomplete renal tubular acidosis (iRTA), 10 recurrent stone formers with normal urinary acidification (NUA) and 10 normal controls (NC). Patients with iRTA had lower plasma standard bicarbonate after fasting (P <0.01) and lower urinary excretion of titratable acid (P <0.05) and citrate (P <0.01) compared with NUA patients and NC, and higher urinary excretion of ammonia (P <0.05) compared with NC (P <0.05). Hypercalciuria was found in 6 of 10 patients with iRTA compared with 3 of 10 with NUA, and 0 of 10 NC. The citrate/calcium ratio in urine was significantly reduced in iRTA compared with the value in NUA (P <0.01), and in NUA compared with NC (P <0.05). Biochemical markers of bone formation (serum osteocalcin) and bone resorption (urinary hydroxyproline) were significantly increased in iRTA ...

1993-01-01

463

Involvement of protein kinase C in the mechanism of action of Escherichia coli heat-stable enterotoxin (STa) in a human colonic carcinoma cell line, COLO-205  

International Nuclear Information System (INIS)

The present study was undertaken to determine the involvement of calcium-protein kinase C pathway in the mechanism of action of Escherichia coli heat stable enterotoxin (STa) apart from STa-induced activation of guanylate cyclase in human colonic carcinoma cell line COLO-205, which was used as a model cultured cell line to study the mechanism of action of E. coli STa. In response to E. coli STa, protein kinase C (PKC) activity was increased in a time-dependent manner with its physical translocation from cytosol to membrane. Inhibition of the PKC activity in membrane fraction and inhibition of its physical translocation in response to IP_3-mediated calcium release inhibitor dantrolene suggested the involvement of intracellular store depletion in the regulation of PKC activity. Among different PKC isoforms, predominant involvement of calcium-dependent protein kinase C (PKC#alpha#) was specified using isotype-specific ...

2005-08-01

464

Inactivating calcium-sensing receptor mutations in patients with primary hyperparathyroidism.  

Science.gov (United States)

Objective:? Primary hyperparathyroidism (HPT) is characterised by autonomous secretion of PTH from enlarged parathyroid glands leading, in most patients, to asymptomatic hypercalcaemia. Familial hypocalciuric hypercalcaemia (FHH) is an autosomal dominant disorder caused by inactivating mutations in the calcium sensing receptor (CaSR) gene; it is characterised by lifelong and usually asymptomatic hypercalcaemia. Establishing the correct diagnosis is important because surgery can be curative in HPT, but ineffective in FHH. There is overlap in the diagnostic criteria for the two disorders and some patients carrying inactivating mutations in the CaSR gene, which is suggestive of FHH, also have HPT with hyperplastic parathyroid glands or adenomas. Design and Patients:? CaSR gene mutations were analyzed and clinical and biochemical parameters evaluated in 139 consecutive out-patients presenting with hypercalcaemia and suspected of having HPT. Results:? Six different ...

2011-03-29

465

Gastrointestinal absorption of lead in chicks: involvement of the cholecalciferol endocrine system  

Energy Technology Data Exchange (ETDEWEB)

The role of dietary calcium and phosphorus in modifying the intestinal absorption of lead and also the effect of lead ingestion on the metabolism of cholecalciferol were studied in chicks. The efficiency of absorption of /sup 203/Pb and /sup 47/Ca was increased when the animals were fed a low calcium diet and treated with cholecalciferol. The synthesis of the vitamin D-induced calcium-binding protein (CaBP) was correspondingly increased. When the chicks were depleted of vitamin D and repleted with 1,25-dihydroxycholecalciferol (1,25(OH)/sub 2/D/sub 3/) as their only source of the vitamin, the absorption of both /sup 47/Ca and /sup 203/Pb was unaffected by dietary calcium levels, and no change in CaBP levels occurred. Low dietary intake of phosphorus resulted in an increase in /sup 47/Ca and /sup 203/Pb absorption and in CaBP synthesis when the animals were treated with cholecalciferol. However, when the ...

1984-04-01

466

Gastrointestinal absorption of lead in chicks: involvement of the cholecalciferol endocrine system  

International Nuclear Information System (INIS)

The role of dietary calcium and phosphorus in modifying the intestinal absorption of lead and also the effect of lead ingestion on the metabolism of cholecalciferol were studied in chicks. The efficiency of absorption of "2"0"3Pb and "4"7Ca was increased when the animals were fed a low calcium diet and treated with cholecalciferol. The synthesis of the vitamin D-induced calcium-binding protein (CaBP) was correspondingly increased. When the chicks were depleted of vitamin D and repleted with 1,25-dihydroxycholecalciferol [1,25(OH)_2D_3] as their only source of the vitamin, the absorption of both "4"7Ca and "2"0"3Pb was unaffected by dietary calcium levels, and no change in CaBP levels occurred. Low dietary intake of phosphorus resulted in an increase in "4"7Ca and "2"0"3Pb absorption and in CaBP synthesis when the animals were treated with cholecalciferol. However, when the birds were repleted with ...

467

Gamma interferon induces rapid and coordinate activation of mitogen-activated protein kinase (extracellular signal-regulated kinase) and calcium-independent protein kinase C in human monocytes.  

UK PubMed Central (United Kingdom)

Gamma interferon plays an important role in regulating the functional properties of mononuclear phagocytes. In the present study, the role of activated protein kinases in the mechanism of action of...Full Text Available

1994-07-01

468

Differential Roles for STIM1 and STIM2 in Store-Operated Calcium Entry in Rat Neurons  

UK PubMed Central (United Kingdom)

The interaction between Ca2+ sensors STIM1 and STIM2 and Ca2+ channel-forming protein ORAI1 is a crucial element of ...Full Text Available

469

Autocrine regulation of T-cell activation by ATP release and P2X7 receptors  

UK PubMed Central (United Kingdom)

T-cell activation requires the influx of extracellular calcium, although mechanistic details regarding such activation are not fully defined. Here, we show that P2X7 receptors play a key...Full Text Available

2009-06-01

470

A progress for the health of south countries. The solar refrigerator; Un progres pour la sante dans les pays du Sud. Le refrigerateur solaire  

Energy Technology Data Exchange (ETDEWEB)

In order to conserve vaccines in hot countries a solar refrigerator has been made by a French university. It is a photothermal refrigerator without batteries. It uses two gases: ammonia and calcium chloride. The refrigerator is autonomous and can work eleven days without sun. (N.C.)

1998-05-01

471

World Declaration on Nutrition 1  

Wastenet

...5 kg or less) to less than 10 percent; (c) Reduction of iron deficiency anemia in women by one-third of the 1990 levels; (d) Virtual elimination of iodine deficiency disorders; (e) Virtual elimination of vitamin A deficiency and its consequences, including blindness; (...

472

Utilizing Gorlovsk Basin anthracite in metallurgical production  

British Library Electronic Table of Contents (United Kingdom)

The composition and physicochemical properties of Gorlovsk Basin anthracite are studied, with a view to expanding its metallurgical use. In industrial tests, anthracite is employed in smelting hot metal in cupola furnaces, in the production of carbonized products and briquets, in ferroalloy production, in sintering iron ore, and in batch for foundry coke.

2008-01-01

473

The Mammalian Neuroendocrine Hormone Norepinephrine Supplies Iron for Bacterial Growth in the Presence of Transferrin or Lactoferrin  

UK PubMed Central (United Kingdom)

Norepinephrine stimulates the growth of a range of bacterial species in nutritionally poor SAPI minimal salts medium containing 30% serum. Addition of size-fractionated serum components to SAPI...Full Text Available

2000-11-01

474

Sulfur dioxide oxidation catalyst and process  

Energy Technology Data Exchange (ETDEWEB)

A catalytic process for the oxidation of sulfur-containing gases , E.G., sulfur dioxide and simultaneous production of sulfuric acid wherein a sulfur-containing gas is reacted with an oxygencontaining gas in the presence of a catalyst comprising an iron group metal on a solid support comprising a zeolite in a silicaalumina matrix.

1981-01-13

475

Study on effectiveness of transfusion program in thalassemia major patients receiving multiple blood transfusions at a transfusion centre in Western India  

UK PubMed Central (United Kingdom)

Background:Children suffering from beta-thalassemia major require repeated blood transfusions which may be associated with dangers like iron overload and contraction of...Full Text Available

2010-07-01

476

Simulation of the electron-paramagnetic-resonance spectrum of the iron-protein of nitrogenase. A prediction of the existence of a second paramagnetic centre.  

UK PubMed Central (United Kingdom)

The e.p.r. spectra of the Fe-proteins of nitrogenase from all sources studied have unusual features in that they have very anisotropic linewidths and low integrated intensities. These characteristics...Full Text Available

1978-12-01

477

Safety Implications of High-Field MRI: Actuation of Endogenous Magnetic Iron Oxides in the Human Body  

UK PubMed Central (United Kingdom)

BackgroundMagnetic Resonance Imaging scanners have become ubiquitous in hospitals and high-field systems (greater than 3 Tesla) are becoming increasingly common. In light of recent...Full Text Available

478

Rhizosphere Acidification by Iron Deficient Bean Plants: The Role of Trace Amounts of Divalent Metal Ions  

UK PubMed Central (United Kingdom)

Rhizosphere acidification by Fe-deficient bean (Phaseolus vulgaris L.) plants was induced by trace amounts of divalent metal ions (Zn, Mn). The induction of this Fe-efficiency reaction...Full Text Available

1989-05-01

479

Process for purifying alumina  

Energy Technology Data Exchange (ETDEWEB)

In a process for separating insoluble red mud from Bayer process streams the improvement is described which comprises contacting and mixing a Bayer process stream with a tertiary polyamine having a molecular weight of at least about 10,000 in an amount effective to reduce the iron content thereof.

1988-01-05

480

Preparation and characterization of iron oxide thin films by spray pyrolysis using methanolic and ethanolic solutions  

International Nuclear Information System (INIS)

Iron oxide thin films have been obtained by spray pyrolysis using 100% methanolic and ethanolic solutions of iron tri-chloride. The films were deposited onto ITO-coated glass substrates. The preparative conditions have been optimized to obtain compact, pin-hole-free and smooth thin films which are adherent to the substrate. The structural, morphological and compositional characterizations have been carried out by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis. The films deposited using ethanolic solution results into pure hematite; #alpha#-Fe_2O_3 thin films, however, films deposited using methanolic solution consists of hematite and maghemite-c phases of iron oxide. The films are nanocrystalline with particle size of 30-40 nm. The optical absorbance of the film was of the order of 10"5 cm"-"1. The optical band gap of films was found to be 2.26 and 2.20 eV for the films deposited using ...

2006-01-15

481

Physico-chemical, optical and electrochemical properties of iron oxide thin films prepared by spray pyrolysis  

International Nuclear Information System (INIS)

Iron oxide thin films were prepared by spray pyrolysis technique onto glass substrates from iron chloride solution. They were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and (UV-vis) spectroscopy. The films deposited at T _s #<=# 450 deg. C were amorphous; while those produced at T _s_u_b = 500 deg. C were polycrystalline #alpha#-Fe_2O_3 with a preferential orientation along the (1 0 4) direction. By observing scanning electron microscopy (SEM), it was seen that iron oxide films were relatively homogeneous uniform and had a good adherence to the glass substrates. The grain size was found (by RX) between 19 and 25 nm. The composition of these films was examined by X-ray photoelectron spectroscopy and electron probe microanalysis (EPMA). These films exhibited also a transmittance value about 80% in the visible and infrared range. The cyclic ...

2006-12-15

482

Natural gels: crystal-chemistry of short range ordered components in Al, Fe, and Si systems  

Energy Technology Data Exchange (ETDEWEB)

In this review, the most important inorganic natural gels are presented: opal, aluminosilicate (allophanes) and hydrous iron oxides and silicates. It is demonstrated that natural gels are ordered at the atomic scale. In allophanes, Al is distributed between octahedral and tetrahedral sites. The amount of Al increases as Al/Si ratio decreases. Si-rich allophane have a local structure around Al and Si very different of that is known in kaolinite or halloysite. Transformation of Si-rich allophanes to crystallized minerals implies dissolution-recrystallization processes. On the contrary, in iron silicate with Fe/Si = 0.72, Si and Fe environments are close to those found in nontronite. The gel transformation to Fe-smectite may occur by long range ordering during ageing. In ferric silicate gels, the similarity of local structure around Fe in poorly ordered precursors and what is known in crystallized minerals suggests a solid transformation during ...

1997-07-01

483

Mutation analysis of the ferritin L-chain gene in age-related cataract  

UK PubMed Central (United Kingdom)

PurposeTo investigate whether acquired somatic mutations in the iron response element of the ferritin L-chain gene account for the age-related cataract.MethodsThe...Full Text Available

484

Mechanical properties of an as-cast heavy-sectioned ferritic spheroidal graphite cast iron  

Energy Technology Data Exchange (ETDEWEB)

In the production of heavy-sectioned ferritic spheroidal graphite iron castings for such parts as spent fuel shipping container (cask), undesirable structures like abnormal graphite lamella, pearlite or so-called chinese script type of inclusions tend to appear, deteriorating the mechanical properties at the central part of the section where molten iron freezes last. 500 mm thick cylindrical vessels with bottom, weighing 18 tons and 33 tons, were poured as trial products of casks. Solidification structure and mechanical properties were examined at many portions of the castings. By controlling chemical composition, solidification time and inoculation process the structure and the mechanical properties in the last portion of the section to solidify were improved. Sufficiently homogeneous heavy-sectioned ferritic spheroidal graphite iron castings were successfully produced in the as-cast state. In addition, quality assurance ...

1987-11-01

485

Intelligent control of cupola melting  

Energy Technology Data Exchange (ETDEWEB)

The cupola is a furnace used for melting steel scrap, cast iron scrap, and ferroalloys to produce cast iron. Its main energy source is coal coke. It is one of the oldest methods of producing cast iron, and it remains the dominate method because of its simplicity and low fuel cost. Cupolas range in size from 18 inches to 13 feet in diameter, and can produce up to 100 tons per hour of cast iron. Although cupola melting has a long history, automatic control has been elusive because the process has been poorly understood. Most foundries rely on the intuition of experienced operators to make control decisions. The purpose of this work, which has been underway for three years of an anticipated four year program, is to develop a controller for the cupola using intelligent and conventional control methods. The project is a cooperative effort between the Idaho National Engineering and Environmental Laboratory, ...

1997-05-01

486

Influence of iron deficiency in the radiopharmaceutical behavior of red blood cells labeled with "9"9"mTc("9"9"mTC-RBC)  

International Nuclear Information System (INIS)

Full text: Red blood cells (RBCs) labeled with "9"9"mTc are commonly used in the evaluation of cardiac function, gastrointestinal tract bleeding, red blood cell volume or splenic sequestration. Generally stannous ion is used as reducing agent. A proposed mechanism is that once the stannous ion (Sn) and the pertechnetate ("9"9"mTc) reach the interior of the RBC, the radionuclide is mainly house in the #beta#-chain of hemoglobin. The aim of this study was to determine if hemoglobin content reduction, an indicator of iron deficiency anemia, could affect the efficiency of RBC labeling and the biological distribution of this radiopharmaceutical. We studied 30 rats fed for 3 weeks after weaning with diets with iron contents of 6.5 ppm (group A), 18 ppm (group B) and 100 ppm (control). For all groups, the labeling yields were always higher than 97%; the percentage of radioactivity was mostly founded in blood with almost negligible radioactivity the ...

2005-11-09

487

In vitro growth inhibition of bloodstream forms of Trypanosoma brucei and Trypanosoma congolense by iron chelators  

UK PubMed Central (United Kingdom)

African trypanosomes exert significant morbidity and mortality in man and livestock. Only a few drugs are available for the treatment of trypanosome infections and therefore, the development of new...Full Text Available

488

Identification and validation of heavy metal and radionuclide hyperaccumulating terrestrial plant species. Quarterly technical progress report, March 20, 1995--June 20, 1995  

Energy Technology Data Exchange (ETDEWEB)

The biological accumulation of heavy metals and cesium, strontium, and uranium in plants is discussed. The role of nutrient deficiencies and foliar treatments of manganese and iron compounds is described.

1995-12-01

489

Experimental control of a cupola furnace  

Energy Technology Data Exchange (ETDEWEB)

In this paper the authors present some final results from a research project focused on introducing automatic control to the operation of cupola iron furnaces. The main aim of this research is to improve the operational efficiency and performance of the cupola furnace, an important foundry process used to melt iron. Previous papers have described the development of appropriate control system architectures for the cupola. In this paper experimental data is used to calibrate the model, which is taken as a first-order multivariable system with time delay. Then relative gain analysis is used to select loop pairings to be used in a multiloop controller. The resulting controller pairs melt rate with blast volume, iron temperature with oxygen addition, and carbon composition with metal-to-coke ratio. Special (nonlinear) filters are used to compute melt rate from actual scale readings of the amount of iron ...

1998-08-01

490

Evaluation of heterogeneity in thickness of passive films on pure iron by scanning electrochemical microscopy  

Energy Technology Data Exchange (ETDEWEB)

Scanning electrochemical microscopy (SECM) was applied to evaluate the heterogeneity of a passive film formed on a pure iron electrode in deaerated pH 8.4 borate solution. A probe current image of SECM was measured with a tip-generation/sub-strate-collection (TO/SC) mode in deaerated pH 8.4 borate solution containing 0.03 moldm{sup -3} Fe(CN){sub 6}{sup 4-} as a mediator. The difference in thickness of passive films formed on two iron plates at different potentials could be evaluated from the probe current image. The probe current image of the passivated iron surface with distinctive crystal grains was composed of the patch patterns, the shapes of which coincided completely with the shapes of the substrate crystal grains. The probe current flowed above the grain surface oriented to {l_brace}100{r_brace} plane was less than that above the grain surface oriented to {l_brace}110{r_brace} or {l_brace}111{r_brace} plane. The ...

1999-04-01

491

Effect of iron catalyst on the composition of oil from coal liquefaction  

Energy Technology Data Exchange (ETDEWEB)

The effect of two iron catalysts, red mud and CGS S-G, as well as Co-Mo/Al/sub 2/O/sub 3/ and Ni-Mo/Al/sub 2/O/sub 3/ commercial catalysts on the composition of oil derived from the liquefaction of Japanese subbituminous coal have been investigated comparatively by conventional autoclave experiments at 440 and 450C under initial hydrogen pressure of 85kg/cm/sup 2/ . G with tetralin to coal weight ratio of 3. From the results obtained at 450C, total conversion and the yield of gas revealed almost same level with four catalysts, but the oil product from molybdenum catalysts showed higher yield than that from iron catalysts. CGS S-G catalyst also showed higher yield of oil product than red mud catalyst. Reaction behavior of two iron catalysts were also tested by solvent recycle mode experiments.

1987-01-01

492

Differential expression of Haemophilus parasuis genes in response to iron restriction and cerebrospinal fluid  

UK PubMed Central (United Kingdom)

Haemophilus parasuis is an important opportunistic pathogen in swine of high health status, but to date no proven virulence factors have been described. As virulence factors are known...Full Text Available

2007-07-01

493

Development of a Coke-Free Cupola Furnace. Energy Conserving Shaft Furnace for Iron Materials. Final Report.  

Science.gov (United States)

Coke-fired cupola furnaces were improved and made suitable for the production of high-quality casting melts by numerous additional devices. Moreover, they were equipped with environmental protection systems with numerous dust separation devices and afterb...

1986-01-01

494

Decreased CSF Transferrin in sCJD: A Potential Pre-Mortem Diagnostic Test for Prion Disorders  

UK PubMed Central (United Kingdom)

Sporadic Creutzfeldt-Jakob-disease (sCJD) is a fatal neurodegenerative condition that escapes detection until autopsy. Recently, brain iron dyshomeostasis accompanied by increased transferrin (Tf) was...Full Text Available

495

Curcumin, a cancer chemopreventive and chemotherapeutic agent, is a biologically active iron chelator  

UK PubMed Central (United Kingdom)

Curcumin is a natural product currently in human clinical trials for a variety of neoplastic, preneoplastic, and inflammatory conditions. We previously observed that, in cultured cells, curcumin exhibits...Full Text Available

2009-01-08

496

Cupola Furnace: Machine-Readable Bibliographic Data Base.  

Science.gov (United States)

One of the tasks comprising ERDA Contract EY-76-S-02-2840, ''Minimization of Cupola Energy and Air Pollution,'' has been the carrying out of a comprehensive survey of world literature relating to the cupola furnace for melting of cast iron. It was decided...

1978-01-01

497

Characterization and gas-sensing behavior of an iron oxide thin film prepared by atomic layer deposition  

International Nuclear Information System (INIS)

In this work we investigate an iron oxide thin film grown with atomic layer deposition for a gas sensor application. The objective is to characterize the structural, chemical, and electrical properties of the film, and to demonstrate its gas-sensitivity. The obtained scanning electron microscopy and atomic force microscopy results indicate that the film has a granular structure and that it has grown mainly on the glass substrate leaving the platinum electrodes uncovered. X-ray diffraction results show that iron oxide is in the #alpha#-Fe_2O_3 (hematite) phase. X-ray photoelectron spectra recorded at elevated temperature imply that the surface iron is mainly in the Fe"3"+ state and that oxygen has two chemical states: one corresponding to the lattice oxygen and the other to adsorbed oxygen species. Electric conductivity has an activation energy of 0.3-0.5 eV and almost Ohmic current-voltage dependency. When exposed to O_2 ...

2008-07-31

498

Catalyst for olefin production  

Energy Technology Data Exchange (ETDEWEB)

A process is claimed for selectively preparing alpha-olefins having from 2 to about 22 carbon atoms by contacting a gaseous mixture containing carbon monoxide and hydrogen with an iron titanate alkali metal hydroxide catalyst at reaction conditions correlated so as to favor the formation of a substantial proportion of such alpha-olefin product.

1981-04-14

499

Bacterial response to siderophore and quorum-sensing chemical signals in the seawater microbial community  

UK PubMed Central (United Kingdom)

BackgroundOceans are iron-deficient and nutrient-poor environments. These conditions impart limitations on our understanding of and our ability to identify microorganisms from the...Full Text Available

500

Assembly of Linear Nano-Chains from Iron Oxide Nanospheres with Asymmetric Surface Chemistry  

Science.gov (United States)

Besides the multifunctionality, another equally important aspect of nanoparticles is their engineerability to control the geometrical and chemical properties during fabrication. In this work, we exploited this aspect to define asymmetric surface chemistry of an iron oxide nanosphere by controlling the topology of ligand expression on its surface resulting in a particle with two faces, one displaying only amines and the other only thiols. Specifically, amine-functionalized iron oxide nanospheres were attached on a solid support via a crosslinker containing a disulfide bridge. Liberation of the nanosphere using thiolytic cleavage created thiols on the portion of the particle's surface that interacted with the solid support. Employing a solid-phase strategy and a step-by-step addition of particles, the two unique faces on the same nanosphere served as fittings to assemble them into linear nano-chains. Assembly of chains with various lengths and ...

2011-01-06