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1

Effects of Different Fabrication Techniques on the Yttrium-Barium-Copper Oxide High Temperature Superconductor.  

National Technical Information Service (NTIS)

This study examines how several different parameters were changed in the yttrium-barium-copper oxide superconductor when the fabrication techniques were altered by using different barium precursors, including barium peroxide and barium carbonate; sinterin...

P. A. Rhea

1988-01-01

2

Synthesis of nanocomposites comprising iron and barium hexaferrites  

Microsoft Academic Search

Composites of nanometre-sized ?-iron and barium hexaferrite phases, respectively, have been synthesized by the ceramic processing route. Pure barium hexaferrite (BaO·6Fe2O3) was first of all prepared by calcinations of the precursor oxides at a maximum temperature of 1200°C for 4h. By subjecting the resulting powder having particle size of the order of 1?m to a reduction treatment in the temperature

M. Pal; S. Bid; S. K Pradhan; B. K Nath; D. Das; D. Chakravorty

2004-01-01

3

Effects of different fabrication techniques on the Yttrium-Barium-Copper oxide high temperature superconductor  

NASA Astrophysics Data System (ADS)

This study examines how several different parameters were changed in the yttrium-barium-copper oxide superconductor when the fabrication techniques were altered by using different barium precursors, including barium peroxide and barium carbonate; sintering at different temperatures, including 850, 900, 950 C; and annealing in an above ambient oxygen environment. Twelve different pellets were fabricated, and measurements were taken on them which included density, X-ray diffraction, critical temperature, critical current density, and magnetic susceptibility. The results showed that the barium peroxide derived samples had higher densities, better critical current densities and lower resistivities in the normal state.

Rhea, Paul A.

1988-12-01

4

Synthesis and properties of barium titanate solid solution thin films deposited on copper substrates  

Microsoft Academic Search

Barium titanate thin films were deposited via chemical solution deposition using a hybrid-chelate chemistry directly on copper foil substrates. A process was developed to crystallize and densify the ferroelectric films at 900°C by using a reductive atmosphere containing nitrogen, hydrogen, water vapor, and oxygen impurities such that film constituents were oxidized to form barium titanate and the foil substrate remained

Jon Fredrick Ihlefeld

2006-01-01

5

Reactions of barium-yttrium-copper oxides with aqueous media and their applications in structural characterization  

SciTech Connect

Leach studies carried out on barium-yttrium-copper oxides in water and in 0.05 M KI have shown the selective occurrence of two processes, vic. leaching of barium and loss of excess oxygen, e.g. through oxidation of iodide. The extent of these two processes during the early stages is much larger in the case of open structures, e.g. the tetragonal phase. Accordingly, leaching in aqueous media provides a sensitive and convenient method of structural characterization.

Barkatt, A.; Hojaji, H.; Michael, K.A. (Vitreous State Univ., Washington, DC (USA))

1987-07-01

6

Effects of different fabrication techniques on the yttrium-barium-copper oxide high-temperature superconductor. Master's thesis  

SciTech Connect

This study examines how several different parameters were changed in the yttrium-barium-copper oxide superconductor when the fabrication techniques were altered by using different barium precursors, including barium peroxide and barium carbonate; sintering at different temperatures, including 850, 900, and 950 C; and annealing in an above ambient oxygen environment. Twelve different pellets were fabricated, and measurements were taken on them which included density, x-ray diffraction, critical temperature, critical current density, and magnetic susceptibility. Results showed that the barium perioxide derived samples had higher densities, better critical current densities and lower resistivities in the normal state.

Rhea, P.A.

1988-12-01

7

Absorbing properties and structural design of microwave absorbers based on carbonyl iron and barium ferrite  

NASA Astrophysics Data System (ADS)

Carbonyl iron and barium ferrite powder (BaZn1.5Co0.5Fe16O27) were prepared in this work. The complex permittivity and permeability spectra for rubber radar absorbing materials employing carbonyl iron and barium ferrite powders were measured. A database describing the frequency dependence of the permittivities and permeabilities of the carbonyl iron and barium ferrite microwave absorbers with various powder percentage compositions in 2 18 GHz was created. Based on the database, the single-layer and double-layer absorbers were designed and prepared, and their microwave absorption properties were investigated. The results indicate that the carbonyl iron powder prepared via thermal decomposition of iron pentacarbonyl is single cubic iron and of spherical shape. The barium ferrite powder is single W-type ferrite and a hexagonal flake. The absorption band of the double-layer microwave absorber is obviously more than that of the single-layer absorber. The double-layer microwave absorbers with reflection loss <-13 dB over the range of 6 18 GHz and reflection loss <-8 dB over the range of 2 18 GHz were prepared. The thicknesses of the absorbers are only 3.6 and 3.7 mm, respectively.

Feng, Y. B.; Qiu, T.; Shen, C. Y.

2007-11-01

8

Fabrication, characterization and microwave properties of polyurethane nanocomposites reinforced with iron oxide and barium titanate nanoparticles  

Microsoft Academic Search

Polyurethane (PU) nanocomposites reinforced with magnetic iron oxide nanoparticles and\\/or dielectric barium titanate nanoparticles fabricated by the surface-initiated-polymerization approach were investigated. The polymer matrix incorporated with different nanoparticles shows different presenting status surrounding the nanoparticles, i.e., chemical bonding, physical entanglement and bulk polymer chain. The nanoparticles have a different effect on the thermal stability of the polymer nanocomposites. By embedding

Z. Guo; S.-E. Lee; H. Kim; H. T. Hahn; A. B. Karki; D. P. Young

2009-01-01

9

Copper Plating of Iron and Steel Wires by Cementation.  

National Technical Information Service (NTIS)

The article discusses the copper plating of iron and steel wires by concentration. Beside an introduction in the treatment procedure as used in the wire industry, some theoretical considerations of the mechanism of copper deposition are presented. Experim...

H. Y. Oei

1971-01-01

10

Iron and copper release in drinking-water distribution systems.  

PubMed

A large-scale pilot study was carried out to evaluate the impacts of changes in water source and treatment process on iron and copper release in water distribution systems. Finished surface waters, groundwaters, and desalinated waters were produced with seven different treatment systems and supplied to 18 pipe distribution systems (PDSs). The major water treatment processes included lime softening, ferric sulfate coagulation, reverse osmosis, nanofiltration, and integrated membrane systems. PDSs were constructed from PVC, lined cast iron, unlined cast iron, and galvanized pipes. Copper pipe loops were set up for corrosion monitoring. Results showed that surface water after ferric sulfate coagulation had low alkalinity and high sulfates, and consequently caused the highest iron release. Finished groundwater treated by conventional method produced the lowest iron release but the highest copper release. The iron release of desalinated water was relatively high because of the water's high chloride level and low alkalinity. Both iron and copper release behaviors were influenced by temperature. PMID:17886579

Shi, Baoyou; Taylor, James S

2007-09-01

11

Copper and nickel partitioning in iron meteorites  

SciTech Connect

Trace element analyses using proton induced x-ray emission (PIXE) and synchrotron x-ray fluorescence (SXRF) have been made on metal and troilite from 9 iron meteorites representing 5 geochemical groups. Nickel and copper distribution coefficients D (troilite/metal) vary by factors of 600 and 20, respectively, correlate positively with kamacite band width and correlate negatively with bulk nickel content. Meteorites with bulk Ni < 10% have Cu-enriched troilite (D{sub Cu} > 1) while those with Ni > 10% have Cu-depleted troilite (D{sub Cu} < 1). Since magmatic evolution and partial melting will produce Cu-enriched troilite only, the observation of Cu-depleted troilite in Ni-rich meteorites is evidence for subsolidus re-equilibration, a process which reduces D{sub Cu} by transfer of Cu to exsolving metal. Elemental redistribution may have played an important role in establishing the present chemical trends in iron meteorites.

Sutton, S.R. (Brookhaven National Lab., Upton, NY (USA) Univ. of Chicago, IL (USA)); Smith, J.V. (Univ. of Chicago, IL (USA)); Delaney, J.S.; Prinz, M. (American Museum of Natural History, New York, NY (USA))

1987-10-01

12

Iron versus Copper II. Principles and Applications in Bioinorganic Chemistry.  

ERIC Educational Resources Information Center

|Discusses the differences between iron and copper. Describes various aspects of the behaviors of these two elements, including those of biological and environmental significance. Addresses the evolution of the atmosphere and sedimentary ore formation, the phylogeny of iron and copper, and some anthropological notes regarding the use of the…

Ochiai, Ei-Ichiro

1986-01-01

13

Old Iron, Young Copper: from Mars to Venus  

Microsoft Academic Search

Iron and copper are metals which play an important role in the living world. From a brief consideration of their chemistry and biochemistry we conclude that the early chemistry of life used water soluble ferrous iron while copper was in the water-insoluble Cu(I) state as highly insoluble sulphides. The advent of oxygen was a catastrophic event for most living organisms,

R. R. Crichton; J.-L. Pierre

2001-01-01

14

Double phase conjugation in copper-doped potassium sodium strontium barium niobate crystals  

NASA Astrophysics Data System (ADS)

We show a double phase conjugator with novel crystals of copper-doped potassium sodium strontium barium niobate. The phase conjugation reflectivity can reach 278 and depends on relative input positions of both incident beams. The response time with the input beam power ratio is measured and modeled as a function of input beam power ratio. The formation of the arch coupling loop is analyzed with theoretical simulation results and a positive feedback process is proposed. The influence of a self-pumped phase conjugation process on double phase conjugation fidelity is also discussed. It is necessary to avoid generating self-pumped phase conjugation to prevent the reduction of double phase conjugation fidelity.

Zhang, Liangmin; Zhang, Wanlin; Chen, Xiaojun; Zhang, Guangyin; Pan, Shihong; Zhang, Jingwen; Shao, Zongshu; Han, Jianru; Chen, Huanchu

1997-06-01

15

Metabolism of manganese, iron, copper, and selenium in calves  

SciTech Connect

Sixteen male Holstein calves were used to study manganese and iron metabolism. The calves were fed one of the following diets for 18 days: control, control + iron, control + manganese, and control + iron and manganese. All calves were dosed orally with manganese-54. Tissue concentrations of manganese, iron and manganese-54 were determined. Small intestinal iron was lower in calves fed the high manganese diet than in controls. Tissue manganese-54 was lower in calves fed a high manganese diet. Fecal manganese content increased in calves fed both high manganese and high manganese-high iron diets. Serum total iron was not affected by the dietary treatments. To study the effects of high dietary levels of copper and selenium on the intracellular distributions of these two elements in liver and kidney cytosol, calves were fed one of four diets for 15 days. These were 0 and 100 ppM supplemental copper and 0 and 1 ppM added selenium. The control diet containing 0.1 ppM of selenium and 15 ppM of copper. All calves were orally dosed 48 hrs prior to sacrifice with selenium-75. A high copper diet increased copper concentrations in all intracellular liver fractions and most kidney fractions. Only the effects in the liver were significant. Less copper was found in the mitochondria fractions in liver and kidney of calves fed a high selenium diet. Three major copper-binding protein peaks were separated from the soluble fractions of calf liver and kidney. Peak 1 appeared to be the major copper-binding protein in liver and kidney cytosol of copper-loaded animals. Added selenium alone or in combination with copper accentuated the copper accumulation in this peak. Most of selenium-75 was recovered in the same peak as the copper. The results of this experiment indicated that the large molecular proteins in liver and kidney cytosol of calves play an important role in copper and selenium-75 metabolism. (ERB)

Ho, S.Y.

1981-01-01

16

Moessbauer study on barium ferrite magnetic recording media and iron-based thin films  

SciTech Connect

Moessbauer spectroscopy and magnetic measurements (VSM) are employed to study pure and Co-Ti substituted barium ferrite and iron-based thin films. For substituted barium ferrite, the Moessbauer spectra are superposition of five subspectra because of the five different environments of the Fe[sup 3+] ions. The author observes that spectral peak width broadens as Co-Ti substitution increases, eventually leading to very poor resolution. In this work, a series of Co-Ti substituted barium ferrite samples have been studied at room temperature in an applied field only up to 0.8 T with transmission geometry Moessbauer spectroscopy. A difference in applied-field spectra compared with zero-field spectra is observed. A computer program for generating applied Moessbauer spectra for powdered ferrimagnetic samples [11] has been implemented. Assuming a 2-sublattice structure, and comparing the simulated and experimental spectra, the author obtains a value of the anisotropy field for pure barium ferrite at room temperature of 0.35 [+-] 0.05 T. Conversion electron Moessbauer spectrometry has been used to study two series of Fe films sputtered at high and low argon pressures with variable thickness of 50 to 1000 nm. The relative intensities of the (2,5) components of the Zeeman sextet decrease with increasing film thickness for samples deposited at high argon pressure. In contrast, films deposited for samples deposited at high argon pressure. In contrast, films deposited at low argon pressure exhibit only a small decrease in (2,5) intensities over the thickness range studied, suggesting that moments retain in-plane orientation. The analysis shows that CEMS is a sensitive tool to investigate magnetic moment orientation in thin films and can supply useful information on the perpendicular anisotropy K[perpendicular] of thin films which can not be obtained by VSM or torque measurements.

Hai, J.O.

1993-01-01

17

Copper Stress Affects Iron Homeostasis by Destabilizing Iron-Sulfur Cluster Formation in Bacillus subtilis?  

PubMed Central

Copper and iron are essential elements for cellular growth. Although bacteria have to overcome limitations of these metals by affine and selective uptake, excessive amounts of both metals are toxic for the cells. Here we investigated the influences of copper stress on iron homeostasis in Bacillus subtilis, and we present evidence that copper excess leads to imbalances of intracellular iron metabolism by disturbing assembly of iron-sulfur cofactors. Connections between copper and iron homeostasis were initially observed in microarray studies showing upregulation of Fur-dependent genes under conditions of copper excess. This effect was found to be relieved in a csoR mutant showing constitutive copper efflux. In contrast, stronger Fur-dependent gene induction was found in a copper efflux-deficient copA mutant. A significant induction of the PerR regulon was not observed under copper stress, indicating that oxidative stress did not play a major role under these conditions. Intracellular iron and copper quantification revealed that the total iron content was stable during different states of copper excess or efflux and hence that global iron limitation did not account for copper-dependent Fur derepression. Strikingly, the microarray data for copper stress revealed a broad effect on the expression of genes coding for iron-sulfur cluster biogenesis (suf genes) and associated pathways such as cysteine biosynthesis and genes coding for iron-sulfur cluster proteins. Since these effects suggested an interaction of copper and iron-sulfur cluster maturation, a mutant with a conditional mutation of sufU, encoding the essential iron-sulfur scaffold protein in B. subtilis, was assayed for copper sensitivity, and its growth was found to be highly susceptible to copper stress. Further, different intracellular levels of SufU were found to influence the strength of Fur-dependent gene expression. By investigating the influence of copper on cluster-loaded SufU in vitro, Cu(I) was found to destabilize the scaffolded cluster at submicromolar concentrations. Thus, by interfering with iron-sulfur cluster formation, copper stress leads to enhanced expression of cluster scaffold and target proteins as well as iron and sulfur acquisition pathways, suggesting a possible feedback strategy to reestablish cluster biogenesis.

Chillappagari, Shashi; Seubert, Andreas; Trip, Hein; Kuipers, Oscar P.; Marahiel, Mohamed A.; Miethke, Marcus

2010-01-01

18

Evaluation of Serum Levels of Zinc, Copper, Iron, and Zinc\\/Copper Ratio in Cutaneous Leishmaniasis  

Microsoft Academic Search

Background: The purpose of this study was to evaluate the leve ls of zinc (Zn), copper (Cu), iron (Fe) and zinc\\/ c op- per ratio in the serum of patients with cutaneous l eishmaniasis in Qom Province, center of Iran. Methods: Serum levels of zinc and copper were determined by flame atomic absorption spectrophotometer and serum iron concentration was measured

S Javadian; Z Zamani; R Saghiri; S Sadeghi; B Zarea; Sh Faiaz; F Mirkhani; N Fatemi

19

Adsorption of water on copper, nickel, and iron  

SciTech Connect

In atmospheric corrosion of copper, nickel, and iron, adsorption of water affects corrosion rates. Knowledge of water adsorption and metal oxyhydroxide formation is important in understanding the atmospheric corrosion process. The quartz-crystal microbalance (QCM) technique was used to measure mass changes of copper, nickel, and iron at 0% to 100% relative humidity (RH) and 7 C to 90 C under nitrogen (N{sub 2}) and air environments. Less water was adsorbed on copper, nickel, and iron that formed oxides than on gold. The amount of water adsorption was similar on copper, nickel, and iron under N{sub 2} and air carrier gases. Shapes of isotherms suggested physical adsorption, capillary condensation, and pore filling occurred on all metals and were more significant at higher temperatures. Adsorption isotherms were Type 3 and Type 4 according to the Brunauer-Emmett-Teller (BET) classification.

Lee, S.; Staehle, R.W. [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemical Engineering and Materials Science

1997-01-01

20

Old iron, young copper: from Mars to Venus.  

PubMed

Iron and copper are metals which play an important role in the living world. From a brief consideration of their chemistry and biochemistry we conclude that the early chemistry of life used water soluble ferrous iron while copper was in the water-insoluble Cu(I) state as highly insoluble sulphides. The advent of oxygen was a catastrophic event for most living organisms, and can be considered to be the first general irreversible pollution of the earth. In contrast to the oxidation of iron and its loss of bioavailability as insoluble Fe(III), the oxidation of insoluble Cu(I) led to soluble Cu(II). A new iron biochemistry became possible after the advent of oxygen, with the development of chelators of Fe(III), which rendered iron once again accessible, and with the control of the potential toxicity of iron by its storage in a water soluble, non-toxic, bio-available storage protein (ferritin). Biology also discovered that whereas enzymes involved in anaerobic metabolism were designed to operate in the lower portion of the redox spectrum, the arrival of dioxygen created the need for a new redox active metal which could attain higher redox potentials. Copper, now bioavailable, was ideally suited to exploit the oxidizing power of dioxygen. The arrival of copper also coincided with the development of multicellular organisms which had extracellular cross-linked matrices capable of resisting attack by oxygen free radicals. After the initial 'iron age' subsequent evolution moved, not towards a 'copper age', but rather to an 'iron-copper' age. In the second part of the review, this symbiosis of iron and copper is examined in yeast. We then briefly consider iron and copper metabolism in mammals, before looking at iron-copper interactions in mammals, particularly man, and conclude with the reflection that, as in Greek and Roman mythology, a better understanding of the potentially positive interactions between Mars (iron) and Venus (copper) can only be to the advantage of our species. PMID:11508852

Crichton, R R; Pierre, J L

2001-06-01

21

40 CFR 721.10667 - Slimes and sludges, aluminum and iron casting, wastewater treatment, solid waste.  

Code of Federal Regulations, 2013 CFR

...the treatment of wastewaters during aluminum and iron casting, machining and finishing operations. It may contain aluminum, barium, chromium, copper, iron, lead, manganese, nickel, and zinc.) is subject to reporting under this section for the...

2013-07-01

22

Static and dynamic photoinduced magnetic effects in yttrium-iron garnet lightly doped with barium ions  

SciTech Connect

In yttrium-iron garnet lightly doped with barium, direct measurements of the photoinduced changes in magnetostrictive strains disagree with those in magnetostriction constants at 78-100 K. This is attributed to a considerable photoinduced modification of the initial state in this sample due to a redistribution of the charge (during illumination) between cations of the ferromagnetic octahedral sublattice. In the same sample, the temperature dependence of the photoinduced disaccomodation of magnetic permeability characterizing the initial demagnetized state is measured and calculated. A change in the electron mechanism of the phenomenon during the transition to room temperature is shown. The conclusion about the promising prospects for using such samples for remagnetization by light is advanced.

Vorob'eva, N. V., E-mail: vnv@anrb.ru; Khalilov, R. Z. [Russian Academy of Sciences, Institute of Molecule and Crystal Physics (Russian Federation)

2012-04-15

23

[Chemiluminescent determination of iron, copper and cobalt in the serum].  

PubMed

Iron in the presence of diethylenetriamine, an activator, is a catalyst of the chemiluminescent reaction between 4-diethylaminophthalhydraside and hydrogen peroxide. The following conditions are optimal for iron content determination: concentration of 4-diethylaminophthalhydraside - (4-5) X 10(-5) M, H2O2 - 1 X 10(-3) M, diethylenetriamine - 5 X 10(-4) M; pH 10-11. Chemoluminescent reaction between 4-diethylaminophthalhydrazide and hydrogen peroxide is catalyzed also by copper and cobalt ions. This reaction is studied for the possibility to be used to determine iron, copper and cobalt amount in solution without their preliminary separation. A highly sensitive procedure is developed for chemiluminescent determination of these metals concentration in the blood serum with detection limit for iron 1.0, for copper - 0.1 and for cobalt - 0.05 ng/ml. PMID:4024301

Zaporozhets, O A; Dubovenko, L I; Piatnitski?, I V

24

Effect of phase transformation in higher iron silicide on the electrical conductivity of the multiphase system iron silicide-glass. I. Conductivity mechanisms in a composite, prepared on the basis of iron silicides and barium-borosilicate glass  

Microsoft Academic Search

Conductivity mechanisms for a composite based on cermet containing iron and barium borosilicate glasses are studied. It is established that in the region of elevated (above room) temperatures the resistance of a composite is mainly governed by the conducting properties of metal inclusions consisting of iron silicides and monoboride. In the low-temperature region (T<260 K) With T?180 K transfer of

S. I. Vecherskii; F. A. Sidorenko

1992-01-01

25

Risks of copper and iron toxicity during aging in humans.  

PubMed

Copper and iron are essential but also toxic metals. Their essentiality is known, but their toxicity, except for the genetic overload diseases, Wilson's disease and hemochromatosis, is not so well known. Yet, their toxicities are so general in the population that they are a looming public health problem in diseases of aging and in the aging process itself. Both metals are transition elements, and their resulting redox properties have been used during evolution in the development of oxidative energy generation. But both contribute to the production of excess damaging oxidant radicals. Evolution has kept stores of copper and iron in excess during the reproductive years because they are so vital to life. But the oxidant damage from these excess stores of metals builds up as we age, and natural selection ceases to act after about age 50 since diseases after that do not contribute to reproductive fitness. Diseases of aging such as Alzheimer's disease, other neurodegenerative diseases, arteriosclerosis, diabetes mellitus, and others may all be contributed to by excess copper and iron. A very disturbing study has found that in the general population those in the highest fifth of copper intake, if they are also eating a relatively high fat diet, lose cognition at over three times the normal rate. Inorganic copper in drinking water and in supplements is handled differently than food copper and is therefore more toxic. Trace amounts of copper in drinking water, less than one-tenth of that allowed in human drinking water by the Environmental Protection Agency, greatly enhanced an Alzheimer's-like disease in an animal model. In the last part of this review, I will provide advice on how to lower risks from copper and iron toxicity. PMID:19968254

Brewer, George J

2010-02-15

26

A study on microstructure and toughness of copper alloyed and austempered ductile irons  

Microsoft Academic Search

In this study, ductile irons with and without 1wt% copper alloy were austempered to become austempered ductile irons (ADIs). Microstructure, impact toughness, and fracture toughness were evaluated to determine how both the copper alloying and austempering treatments influenced the toughness properties of ductile irons. The results show that, because copper increases the retained austenite content in ADI, the Cu-alloyed ADI

Cheng-Hsun Hsu; Kuan-Ting Lin

2011-01-01

27

Genotoxicity and mutagenicity of iron and copper in mice  

Microsoft Academic Search

The toxicity of trace metals is still incompletely understood. We have previously shown that a single oral dose of iron or\\u000a copper induces genotoxic effects in mice in vivo, as detected by single cell gel electrophoresis (comet assay). Here, we report\\u000a the effect of these metals on subchronic exposure. Mice were gavaged for six consecutive days with either water, 33.2 mg\\/kg\\u000a iron,

Daniel Prá; Silvia Isabel Rech Franke; Raquel Giulian; Maria Lúcia Yoneama; Johnny Ferraz Dias; Bernardo Erdtmann; João Antonio Pêgas Henriques

2008-01-01

28

Iron, zinc, copper and phytate content of standardized Nigerian dishes  

Microsoft Academic Search

Representative samples of 20 standardized Nigerian dishes were analyzed for Iron, Copper and Zinc using the automated method of flame atomic absorption spectrophotoscopy (AAS) and for phytate using a colorimetric method. Iron contents ranged from 2.28mg\\/100g for cowpeas and yam pottage to 22.10mg\\/100g for Apapafufu with tuwon shinkafa. The zinc contents ranged from 0.43mg\\/100g for stewed beans and fried plantain

O. O Onabanjo; Clara R. B Oguntona

2003-01-01

29

The transition metals copper and iron in neurodegenerative diseases  

Microsoft Academic Search

Neurodegenerative diseases constitute a worldwide health problem. Metals like iron and copper are essential for life, but they are also involved in several neurodegenerative mechanisms such as protein aggregation, free radical generation and oxidative stress. The role of Fe and Cu, their pathogenic mechanisms and possible therapeutic relevance are discussed regarding four of the most common neurodegenerative diseases, Alzheimer's, Parkinson's

Susana Rivera-Mancía; Iván Pérez-Neri; Camilo Ríos; Luis Tristán-López; Liliana Rivera-Espinosa; Sergio Montes

2010-01-01

30

Evaluation of Serum Levels of Zinc, Copper, Iron, and Zinc/Copper Ratio in Cutaneous Leishmaniasis  

PubMed Central

Background: The purpose of this study was to evaluate the levels of zinc (Zn), copper (Cu), iron (Fe) and zinc/ copper ratio in the serum of patients with cutaneous leishmaniasis in Qom Province, center of Iran. Methods: Serum levels of zinc and copper were determined by flame atomic absorption spectrophotometer and serum iron concentration was measured by using an Auto Analyzer. The study group consisted of 60 patients with cutaneous leishmaniasis and the control group of 100 healthy volunteers from the same area who were not exposed to cutaneous leishmaniasis. Result: There were no statistically significant differences in age and body mass index between the two groups. Serum Zn (P< 0.001) and Fe (P< 0.05) levels were lower in patients with cutaneous leishmaniasis than the control group. We also found serum Cu concentration (P< 0.05) in the patient group was significantly higher than that of the control group. However, zinc/ copper ratio (P< 0.001) was lower in patients with cutaneous leishmaniasis than in the control group. Conclusion: Our data indicated that Zn/Cu ratio was significantly lower in patients with CL as compared to the controls. Earlier reports suggest that, this ratio imbalance could be a useful marker for immune dysfunction in leishmaniasis. There was also strong association of Zn, Cu and Fe with CL. It suggests the use of blood zinc, copper, iron concentration and the copper/zinc ratio (Zn/Cu), as a means for estimating the prognosis of CL.

Pourfallah, F; Javadian, S; Zamani, Z; Saghiri, R; Sadeghi, S; Zarea, B; Faiaz, Sh; Mirkhani, F; Fatemi, N

2009-01-01

31

Kinetics of Formation of Yttrium Barium Copper Oxide Superconductor and Lanthanum Strontium Chromium Oxide Interconnects.  

NASA Astrophysics Data System (ADS)

This work studied the reaction mechanism and kinetics of formation of two ceramic materials: (a) rm YBa_2Cu_3O_{7-x} superconductor and (b) rm La_{0.84 }Sr_{0.16}CrO_3 interconnects for solid oxide fuel cells. In situ, time-resolved X-ray diffraction was used to follow the formation kinetics in both cases. The rm YBa_2Cu_3O _{7-x} formation kinetics from a spray-roasted precursor powder containing an intimate mixture of rm Y_2O_3, BaCO_3 and CuO, was studied as a function of gas atmosphere and temperature. It was found that in an oxygen containing environment, high temperatures (800 -840^circC) increased the rm YBa_2Cu_3O_{7 -x} yield. In nitrogen, decomposition of the product occurred at temperatures exceeding 725 ^circC with Y_2BaCuO _5 being one of the decomposition products. The extent of the decomposition was strongly influenced by the temperature. Thus, inert atmosphere is not optimal for rapid rm YBa_2Cu _3O_{7-x} formation. In oxidizing atmospheres, the formation of rm YBa_2Cu_3O_{7-x} involved the formation of BaCuO_2, instead of rm BaCu_2O_2, which was the intermediate in inert atmospheres. At low temperatures ({<}760^circ C) and highly oxidizing environments, one more barium -copper oxide was formed. The presence of CO_2 in the environment inhibited the rm YBa_2Cu_3O_{7-x} formation. Only 1% CO_2 in air completely ceased the reaction at 840^circ C. The experimental data were adequately described by a nuclei growth model assuming two-dimensional, diffusion controlled growth with second-order nucleation rate. The formation of rm La_{0.84 }Sr_{0.16}CrO_3 solid solution from an intimate stoichiometric mixture of LaCrO _3 and SrCrO_4 was also investigated. Unlike the rm YBa _2Cu_3O_{7-x}, the kinetics of rm La_{0.84}Sr _{0.16}CrO_3 formation does not involve the appearance of new diffraction peaks which correspond to the formation of this product. A novel data reduction technique was developed to determine quantitatively phase abundances from in situ high temperature X-ray data and to follow the rate of solid solution formation. The technique is based on the fact that as Sr is incorporated into La_{rm 1-x}Sr _{x}CrO_3 structure, the peak is shifted to higher angles. The linear thermal expansion coefficient of La _{rm 1-x}Sr _{x}CrO_3 with different Sr content was also measured using high temperature X-ray diffraction. It was found that the thermal expansion coefficient was not influenced by Sr content, for 0 <= {rm x} <= 0.16..

Milonopoulou, Vassiliki

32

Serum Concentration of Copper, Zinc, Iron, and Cobalt and the Copper\\/Zinc Ratio in Horses with Equine Herpesvirus1  

Microsoft Academic Search

The serum concentrations of copper, zinc, iron, and cobalt and copper\\/zinc ratio were investigated in horses infected with\\u000a equine herpesvirus-1 (EHV-1). Nine horses were naturally infected with the virus and nine healthy horses served as controls.\\u000a The concentrations of copper, zinc, iron, and cobalt were determined spectrophotometrically in the blood serum of all horses.\\u000a The results were (expressed in micrograms

?brahim Yörük; Yeter Deger; Handan Mert; Nihat Mert; Veysel Ataseven

2007-01-01

33

Effect of austenitization on austempering of copper alloyed ductile iron  

Microsoft Academic Search

A ductile iron containing 0.6% copper as the main alloying element was austempered at a fixed austempering temperature of\\u000a 330 ?C for a fixed austempering time of 60 min after austenitization at 850 ?C for different austenitization periods of 60,\\u000a 90, and 120 min. The austempering process was repeated after changing austenitization temperature to 900 ?C. The effect of\\u000a austenitization

Uma Batra; S. Ray; S. R. Prabhakar

2003-01-01

34

Formation of aromatic chlorinated compounds catalyzed by copper and iron  

Microsoft Academic Search

This study shows the catalyzing effects of iron and copper on the formation of chlorinated compounds such as chlorobenzenes (ClBzs), chlorophenols (CIPhs), polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Both total concentrations and congener distributions have been studied. The parameters and conditions varied during the combustion tests were the complete and incomplete combustion and the metal and chlorine addition. The incomplete

Halonen Ismo; Tuppurainen Kari; Ruuskanen Juhani

1997-01-01

35

Copper, iron and zinc in Alzheimer's disease senile plaques  

Microsoft Academic Search

Concentrations of copper (Cu), iron (Fe) and zinc (Zn) were measured in the rims and cores of senile plaques (SP) and in the neuropil of the amygdala of nine Alzheimer's disease (AD) patients and in the neuropil of the amygdala of five neurologically normal control subjects using micro particle-induced X-ray emission (micro-PIXE). Comparison of SP rim and core values revealed

M. A Lovell; J. D Robertson; W. J Teesdale; J. L Campbell; W. R Markesbery

1998-01-01

36

Removal of copper and iron prior to water hardness titration  

Microsoft Academic Search

Silica gel was reacted with 3-aminopropyltriethoxysilane or with the N-methyl derivative of the same reagent to produce a material with an amino silyl functional group. If a water sample in the pH range of 5.0 to 7.5 is passed through a short column of this material, iron(II) and copper(II) are completely retained, while calcium(II) and magnesium(II) pass through. This permits

James S. Fritz; Jefferey N. King

1976-01-01

37

Copper Deficiency in Sheep with High Liver Iron Accumulation  

PubMed Central

An outbreak of enzootic ataxia among sheep raised in the northeastern region of Brazil is described. Copper (Cu) deficiency was diagnosed in a herd of 56 sheep, among which five presented characteristic clinical symptoms of enzootic ataxia. The symptoms began 30 days after birth, with a clinical condition that included locomotion difficulty, limb ataxia, tremors, and continual falls. Liver biopsies were performed and blood was collected to determine hepatic and plasmatic Cu, iron (Fe), and zinc (Zn) concentration, respectively. The laboratory results showed that the animals presented low copper concentrations in the plasma and liver, without difference between the clinically healthy animals and those affected by enzootic ataxia. Even after supplementation with adequate Cu levels had been recommended, it was found on a new visit to the farm four months later that one animal still presented a clinical condition and that the hepatic Cu levels of the herd had not risen. Despite the low copper content of the diet, the high hepatic Fe levels found suggest that antagonism due to this element may have been an important factor in triggering copper deficiency in these animals, and thus, additional copper supplementation may be necessary for these animals.

de Sousa, Isadora Karolina Freitas; Hamad Minervino, Antonio Humberto; Sousa, Rejane dos Santos; Chaves, Dowglish Ferreira; Barros, Isabella de Oliveira; de Araujo, Carolina Akiko Sato Cabral; Junior, Raimundo Alves Barreto; Ortolani, Enrico Lippi

2012-01-01

38

On the origin of the semiconductivity of ceramic barium-bismuth titanate (IV) doped with iron  

Microsoft Academic Search

A considerable change in the electric conductivity of barium-bismuth titanate (IV) when doped with ferric oxide has been observed. In order to explain the origin of its semiconductive properties a substitution model is presented. This model assumes the entrance of Fe3+ ions into the crystalline lattice in three subsequent stages which mutually differ in the lattice position of the introduced

J. Schwarzbach

1967-01-01

39

Phytoplankton copper requirement under iron limited condition in the coastal Bay of Bengal  

NASA Astrophysics Data System (ADS)

Copper, a redox reactive transition metal, plays a vital role in many cellular redox reactions. Recent investigations show that many eukaryotic microorganisms including marine and coastal diatom utilize copper to perform a high affinity iron acquisition mechanism and the requirement of copper increases with decreasing iron concentrations. However, very less information is available about the role of copper in diatom physiology. Here we report for the first time about the copper utilization by coastal diatom during iron limited condition in the Bay of Bengal coast. The diatom Chaetoceros gracilis was isolated from the Visakhapatnam coast and was grown in different copper concentrations (15nM -1000nM). The concentration of total chlorophyll, the growth rate, the concentration of biogenic silica, the ratio of biogenic silica to particulate organic carbon and the ratio of total chlorophyll to particulate organic carbon were found to be increased with increasing copper concentration up to 125nM and decreased thereafter reaching a minimum value at 1000nM. 13C of Particulate organic carbon varied inversely with increasing copper concentrations indicating the signature of enhanced carbon fixation which is in agreement with the enhanced biomass and growth rate. However, to get a better understanding about the role of copper behind the enhanced growth, we had incubated the cells simultaneously in iron replete, copper replete and in varying copper concentration in presence of 200nM of iron. Surprisingly, in all cases significant enhancement in growth and biomass production was observed. The cells grown in only iron and added with copper showed very similar increase whereas, in presence of iron increasing copper concentration did not show any enhancement effect. Increased growth and biomass production in response to iron addition shows that phytoplankton growth is limited by iron in the study area. Furthermore, this observation indicates that in case of iron limitation the coastal diatom perform a high affinity iron acquisition mechanism where copper plays a vital role. Down regulation of high affinity iron acquisition mechanism was indicated by unaltered growth when copper was added in presence of iron. Collectively, our present study shows that copper likely plays an important role in the physiology of coastal diatom apart from the toxicological studies conducted earlier. A detailed investigation is needed to understand the high affinity iron acquisition mechanism existing in coastal diatom from the study area.

Biswas, H.; Bandyopadhyay, D.; Kumar, P. P.

2012-04-01

40

Iron, zinc, and copper in retinal physiology and disease.  

PubMed

The essential trace metals iron, zinc, and copper play important roles both in retinal physiology and disease. They are involved in various retinal functions such as phototransduction, the visual cycle, and the process of neurotransmission, being tightly bound to proteins and other molecules to regulate their structure and/or function or as unbound free metal ions. Elevated levels of "free" or loosely bound metal ions can exert toxic effects, and in order to maintain homeostatic levels to protect retinal cells from their toxicity, appropriate mechanisms exist such as metal transporters, chaperones, and the presence of certain storage molecules that tightly bind metals to form nontoxic products. The pathways to maintain homeostatic levels of metals are closely interlinked, with various metabolic pathways directly and/or indirectly affecting their concentrations, compartmentalization, and oxidation/reduction states. Retinal deficiency or excess of these metals can result from systemic depletion and/or overload or from mutations in genes involved in maintaining retinal metal homeostasis, and this is associated with retinal dysfunction and pathology. Iron accumulation in the retina, a characteristic of aging, may be involved in the pathogenesis of retinal diseases such as age-related macular degeneration (AMD). Zinc deficiency is associated with poor dark adaptation. Zinc levels in the human retina and RPE decrease with age in AMD. Copper deficiency is associated with optic neuropathy, but retinal function is maintained. The changes in iron and zinc homeostasis in AMD have led to the speculation that iron chelation and/or zinc supplements may help in its treatment. PMID:24160731

Ugarte, Marta; Osborne, Neville N; Brown, Laurence A; Bishop, Paul N

41

Microstructure and electrical properties of Mn-doped barium strontium titanate thin films prepared on copper foils  

NASA Astrophysics Data System (ADS)

Ba 0.7- xSr 0.3Mn xTiO 3 ( x = 0, 0.025, 0.05) thin films have been prepared on copper foils using sol-gel method. The films were processed in an atmosphere with low oxygen pressure so that the substrate oxidation is avoided and the formation of the perovskite phase is allowed. XRD and SEM results showed that Mn doping enhanced the crystallization of the perovskite phase in the films. The Mn substitution prevents the reduction of Ti 4+ to Ti 3+, which is supported by XPS analysis. The Ba 0.7- xSr 0.3Mn xTiO 3 film with x = 0.025 (BSMT25) exhibits preferred dielectric behavior and a lower leakage current density among the three thin films. The dielectric constant and loss of the BSMT25 film are 1213.5 and 0.065 at 1 MHz and around zero field, which are mostly desired for embedded capacitor applications. The mechanism of Mn doping on improving the electrical properties of barium strontium titanate (BST) thin films was investigated.

Fan, Yanhua; Yu, Shuhui; Sun, Rong; Li, Lei; Yin, Yansheng; Wong, Ka-Wai; Du, Ruxu

2010-09-01

42

Iron supplementation does not affect copper and zinc absorption in breastfed infants  

Technology Transfer Automated Retrieval System (TEKTRAN)

Iron supplements are commonly recommended for infants but were suggested to inhibit zinc and copper absorption. The objective of this study was to investigate potential effects of iron supplementation, infant age, and mineral status on zinc and copper absorption in infants at 6 and 9 mo of age. Twen...

43

Iron, copper and zinc in white sugar from Serbian sugar beet refineries  

Microsoft Academic Search

Small amounts of soluble and insoluble impurities such as iron, copper and zinc in refined white sugar determine the usefulness of sugar for various industrial applications. The content of iron, copper and zinc was evaluated in 166 white sugar samples from four Serbian beet sugar refineries during the campaign of 2003. The production of the chosen sugar factories is accounted

B. Škrbi?; J. Gyura

2007-01-01

44

EQCM study of copper and iron corrosion inhibition in presence of organic inhibitors and biocides  

Microsoft Academic Search

Attention has been devoted to the application of quartz crystal microbalance (QCM) in the field of corrosion and corrosion inhibition. In-situ measurements were performed on copper and iron surfaces. Copper corrosion inhibition by the application of several inhibitors was followed by QCM. Copper corrosion inhibition in different electrolyte solutions such as acidic sodium sulphate and neutral sodium chloride were investigated.

J Telegdi; A Shaban; E Kálmán

2000-01-01

45

Comparison of serum levels of iron, zinc and copper in anaemic and non-anaemic pregnant women in China  

Microsoft Academic Search

Zinc and copper deficiency is associated with anaemia or iron deficiency and affects fetus growth and pregnant women during pregnancy. To examine iron, zinc and copper status of Chinese pregnant women with and without anaemia in the third trimester, 1185 subjects were enrolled for measurements of Hb, ferritin, transferrin, soluble transferrin receptor (sTfR), and serum iron, zinc and copper. The

Ai-Guo Ma; Xue-Cun Chen; Rong-Xian Xu; Ming-Ci Zheng; Yu Wang; Jue-Sheng Li

2004-01-01

46

78 FR 65573 - Migratory Bird Hunting; Application for Approval of Copper-Clad Iron Shot and Fluoropolymer Shot...  

Federal Register 2010, 2011, 2012, 2013

...Hunting; Application for Approval of Copper-Clad Iron Shot and Fluoropolymer Shot...Fish and Wildlife Service, approve copper-clad iron shot and fluoropolymer coatings...published a proposed rule for approval of copper-clad iron shot and fluoropolymer...

2013-11-01

47

Early Metal in South India: Copper and Iron in Megalithic Contexts  

Microsoft Academic Search

In South India early metal artifacts, usually associated with megalithic sites, include both copper and iron. Although in\\u000a some cases copper artifacts predate those made of iron, there is no evidence of an extensive metallurgical tradition based\\u000a on copper and its alloys. Typological studies have had limited success in explaining the megalithic sites and the production\\u000a and consumption of metal,

Praveena Gullapalli

2009-01-01

48

Decomposition of the sulfates of copper, iron (II), iron (III), nickel, and zinc: XPS, SEM, DRIFTS, XRD, and TGA study  

Microsoft Academic Search

The bulk and surface characteristics during decomposition of the transition metal sulfates of copper, iron (II), iron (III), nickel, and zinc are investigated utilizing various spectroscopic techniques. An oxidized form of sulfur was detected on the surface during decomposition of all metal sulfate samples, except zinc sulfate. Surface characteristics were not necessarily representative of the bulk characteristics. Oxy-sulfate was observed

Ranjani V Siriwardane; James A Poston Jr; Edward P Fisher; Ming-Shing Shen; Angela L Miltz

1999-01-01

49

[Effect of iron-containing supplements on the level of iron, copper, and manganese in young sportsmen].  

PubMed

In was defined that 2-week intake by senior school pupils of iron-containing supplements combined with an ascorbic acid was followed by a significant increase of iron concentration in plasma and formal blood elements, hemoglobin and erythrocytes level, increase of vitamin C provision and physical performance efficiency at simultaneous decrease of copper and manganese content in blood plasma. PMID:20968011

Za?tseva, I P

2010-01-01

50

Saturation of copper-iron mattes with solid magnetite  

NASA Astrophysics Data System (ADS)

Conditions which lead to the saturation of simple copper-iron mattes with solid magnetite have been evaluated in this study. Diagrams have been developed which illustrate quantitatively the surface of saturation of matte with magnetite in the phase and stability diagrams for the Cu-Fe-S-0 system at 1468 K and 1 atm total pressure. Conditions fo. simultaneous saturation of matte with magnetite and gas ( P so2 + P s2= 1 atm) have also been estimated by extrapolation of the data on magnetitesaturated mattes. Comparison of the results with compositions of mattes from oxygen-enriched smelters indicates that these smelters operate at magnetite saturation under conditions close to equilibrium. Conditions during oxygen-enriched smelting can be predicted from the diagrams given in this paper and correlation equations for the oxygen and sulfur concentrations in magnetitesaturated matte which were previously developed from the experimental data.

Kaiser, D. L.; Elliott, J. F.

1988-12-01

51

Hyperfine field and hyperfine anomalies of copper impurities in iron  

SciTech Connect

A new value for the hyperfine magnetic field of copper impurities in iron is obtained by combining resonance frequencies from experiments involving {beta}-NMR on oriented nuclei on {sup 59}Cu, {sup 69}Cu, and {sup 71}Cu with magnetic moment values from collinear laser spectroscopy measurements on these isotopes. The resulting value, i.e., B{sub hf}(CuFe) = -21.794(10) T, is in agreement with the value adopted until now but is an order of magnitude more precise. It is consistent with predictions from ab initio calculations. Comparing the hyperfine field values obtained for the individual isotopes, the hyperfine anomalies in Fe were determined to be {sup 59{Delta}69}=0.15(9)% and {sup 71{Delta}69}=0.07(11)%.

Golovko, V. V.; Wauters, F.; Breitenfeldt, M.; De Leebeeck, V.; Roccia, S.; Soti, G.; Tandecki, M.; Traykov, E.; Van Gorp, S.; Severijns, N. [Instituut voor Kern- en Stralingsfysica, Katholieke Universiteit Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Cottenier, S. [Center for Molecular Modeling, Ghent University, Technologiepark 903, B-9052 Zwijnaarde (Belgium); Zakoucky, D. [Nuclear Physics Institute, ASCR, CZ-250 68 Rez (Czech Republic)

2011-07-15

52

The commercialization of the FENIX iron control system for purifying copper electrowinning electrolytes  

NASA Astrophysics Data System (ADS)

The FENIX Hydromet Iron Control System was installed at Western Metals Copper Ltd.’s Mt. Gordon Operations in Queensland, Australia. The system uses a novel and patented ion-exchange resin to selectively remove iron from copper electrolyte at the solvent extraction/electrowinning plant. At Mt. Gordon, the system delivered significant savings in reagent consumption (acid and cobalt sulfate for electrowinning and lime for neutralization of the raffinate bleed) and has the potential to deliver higher current efficiencies in copper electrowinning, leading to increased copper production.

Shaw, D. R.; Dreisinger, D. B.; Lancaster, T.; Richmond, G. D.; Tomlinson, M.

2004-07-01

53

Copper Deficiency Leads to Anemia, Duodenal Hypoxia, Upregulation of HIF-2? and Altered Expression of Iron Absorption Genes in Mice  

PubMed Central

Iron and copper are essential trace metals, actively absorbed from the proximal gut in a regulated fashion. Depletion of either metal can lead to anemia. In the gut, copper deficiency can affect iron absorption through modulating the activity of hephaestin - a multi-copper oxidase required for optimal iron export from enterocytes. How systemic copper status regulates iron absorption is unknown. Mice were subjected to a nutritional copper deficiency-induced anemia regime from birth and injected with copper sulphate intraperitoneally to correct the anemia. Copper deficiency resulted in anemia, increased duodenal hypoxia and Hypoxia inducible factor 2? (HIF-2?) levels, a regulator of iron absorption. HIF-2? upregulation in copper deficiency appeared to be independent of duodenal iron or copper levels and correlated with the expression of iron transporters (Ferroportin - Fpn, Divalent Metal transporter – Dmt1) and ferric reductase – Dcytb. Alleviation of copper-dependent anemia with intraperitoneal copper injection resulted in down regulation of HIF-2?-regulated iron absorption genes in the gut. Our work identifies HIF-2? as an important regulator of iron transport machinery in copper deficiency.

Matak, Pavle; Zumerle, Sara; Mastrogiannaki, Maria; El Balkhi, Souleiman; Delga, Stephanie; Mathieu, Jacques R. R.; Canonne-Hergaux, Francois; Poupon, Joel; Sharp, Paul A.; Vaulont, Sophie; Peyssonnaux, Carole

2013-01-01

54

Copper.  

PubMed

Copper is an essential trace element, which is an important catalyst for heme synthesis and iron absorption. Following zinc and iron, copper is the third most abundant trace element in the body. Copper is a noble metal, like silver and gold. Useful industrial properties include high thermal and electrical conductivity, low corrosion, alloying ability, and malleability. Most of the metallic copper appears in electrical applications. Copper is a constituent of intrauterine contraceptive devices and the release of copper is necessary for their contraceptive effects. The average daily intake of copper in the US is about 1 mg Cu with the primary source being the diet. The bioavailability of copper from the diet is about 65-70% depending on a variety of factors including chemical form, interaction with other metals, and dietary components. The biological half-life of copper from the diet is 13-33 days with bilary excretion being the major route of elimination. Copper sulfate is a gastric irritant that produces erosion of the lining of the gastrointestinal tract. Chronic copper toxicity is rare and primarily affects the liver. Wilson's disease and Indian childhood cirrhosis are examples of severe chronic liver disease that results from the genetic predisposition to the hepatic accumulation of copper. The serum copper concentration ranges up to approximately 1.5 mg/L in healthy persons. Gastrointestinal symptoms occur at whole blood concentrations near 3 mg Cu/L. Chelating agents (CaNa2EDTA, BAL) are recommended in severe poisoning, but there are little pharmacokinetic data to evaluate the effectiveness of these agents. PMID:10382557

Barceloux, D G

1999-01-01

55

Electrically and magnetically tunable phase shifters based on a barium strontium titanate-yttrium iron garnet layered structure  

NASA Astrophysics Data System (ADS)

We report on the tuning of permittivity and permeability of a ferroelectric/ferromagnetic bilayer structure which can be used as a microwave phase shifter with two degrees of tuning freedom. The structure was prepared by the growth of a yttrium iron garnet (YIG) layer on a gadolinium gallium garnet substrate by liquid phase epitaxy, the growth of a barium strontium titanate (BST) layer on the YIG layer through pulsed laser deposition, and then the fabrication of a coplanar waveguide on the top of BST through e-beam evaporation and trilayer liftoff techniques. The phase shifters exhibit a differential phase shift of 38°/cm at 6 GHz through permittivity tuning under an applied electric field of ~75 kV/cm and a static magnetic field of 1700 Oe. By tuning the permeability through the applied magnetic field we increase the differential phase shift to 52°/cm and simultaneously obtain a better match to the zero applied electric field condition, resulting in an improvement in the return loss from 22.4 to 24.9 dB. Additionally, we demonstrate the use of a lead magnesium niobate-lead titanate (PMN-PT) layer to tune the permeability of the YIG layer. This tuning relies on the piezoelectric and magnetostrictive effects of PMN-PT and YIG, respectively. Tuning of the ferromagnetic response through strain and magnetostriction as opposed to applied magnetic field can potentially pave the way for low power consumption, continuously and rapidly tunable, impedance matched phase shifters.

Leach, J. H.; Liu, H.; Avrutin, V.; Rowe, E.; Özgür, Ü.; Morkoç, H.; Song, Y.-Y.; Wu, M.

2010-09-01

56

An experimental study for enhancing the catalytic effects of various copper forms on the oxidation of ferrous iron  

Microsoft Academic Search

In this research the catalytic effect of copper compounds (ionic, oxide and oxide nanopowder) on the oxidation of ferrous iron by aeration was studied experimentally. When copper exists in solution, the oxidation rate of iron(ii) will increase. The experimental results showed that the oxidation rate increases with an increasing copper concentration. From the experimental data it can be determined that

Manizhe Moradi Shahre Babak; Ataallah Soltani Goharrizi; Mohammad Mirzaei; Emad Roayaei

2012-01-01

57

Sound emission from high-strength cast iron with copper coatings  

Microsoft Academic Search

1.Application of an electrolytic copper coating causes additional damping of vibrations and reduces the energy of the sound emitted. Such coatings can be used for vibration-absorbing and sound-absorbing materials and structure.2.As compared with gray cast irons, which have quite satisfactory acoustical characteristics, highstrength cast iron with an electrolytic copper coating has lower sound emission (115–116 dB) but higher strength characteristics.

Yu. A. Klimov; B. M. Zlobinskii

1974-01-01

58

The commercialization of the FENIX iron control system for purifying copper electrowinning electrolytes  

Microsoft Academic Search

The FENIX Hydromet Iron Control System was installed at Western Metals Copper Ltd.’s Mt. Gordon Operations in Queensland,\\u000a Australia. The system uses a novel and patented ion-exchange resin to selectively remove iron from copper electrolyte at the\\u000a solvent extraction\\/electrowinning plant. At Mt. Gordon, the system delivered significant savings in reagent consumption (acid\\u000a and cobalt sulfate for electrowinning and lime for

D. R. Shaw; D. B. Dreisinger; T. Lancaster; G. D. Richmond; M. Tomlinson

2004-01-01

59

The commercialization of the FENIX iron control system for purifying copper electrowinning electrolytes  

Microsoft Academic Search

The FENIX Hydromet Iron Control System was installed at Western Metals Copper Ltd.'s Mt. Gordon Operations in Queensland, Australia. The system uses a novel and patented ion-exchange resin to selectively remove iron from copper electrolyte at the solvent extraction\\/electrowinning plant. At Mt. Gordon, the system delivered significant savings in reagent consumption (acid and cobalt sulfate for electrowinning and lime for

D. R. Shaw; D. B. Dreisinger; T. Lancaster; G. D. Richmond; M. Tomlinson

2004-01-01

60

Total iron, heme iron, zinc, and copper content in rabbit meat and viscera.  

PubMed

The aim of this study is to determine the content of total iron (TFe), heme iron (HeFe), zinc (Zn), and copper (Cu) in different cuts of meat and viscera from rabbit. Five young New Zealand rabbits were used in the study. Samples in triplicate were obtained from three meat cuts (foreleg, hind leg, and loin) and from main viscera. TFe, Zn, and Cu concentrations from samples were determined by wet acid digestion followed by atomic absorption spectrophotometry (AAS), while HeFe was determined by acid extraction followed by AAS. Mean TFe, HeFe, Zn, and Cu in meat was 0.83?±?0.09, 0.56?±?0.11, 0.95?±?0.35, and 0.08?±?0.01 mg/100 g, respectively. TFe content was less than 1 mg/100 g in all meat cuts. Sixty-seven percent of iron content was HeFe. The cut of meat with highest Zn concentrations was the foreleg with 1.33?±?0.12 mg/100 g. Cu content was low for all meat cuts. TFe, HeFe, Zn, and Cu content in viscera varied greatly. The spleen was the organ with the highest TFe and Zn concentrations (82.79?±?9.22 mg/100 g and 3.49?±?0.63 mg/100 g, respectively). Nevertheless, the lungs had the highest concentration of HeFe (5.79?±?0.90 mg/100 g), accounting for 91% of the total iron. The liver had the highest Cu content (3.89?±?0.89 mg/100 g). Rabbit meat has low TFe concentration, similar to that of poultry, and most of the iron is HeFe. The amount of minerals in viscera closely depends on their function. PMID:21344293

Valenzuela, Carolina; de Romaña, Daniel Lopez; Schmiede, Camila; Morales, María Sol; Olivares, Manuel; Pizarro, Fernando

2011-02-23

61

Optimization of copper cementation process by iron using central composite design experiments  

Microsoft Academic Search

In this study, the effects of various experimental parameters on the cementation yield of copper by iron were investigated statistically. A statistical experimental design based on the second-order central composite rotatable design (CCRD) was planned fixing the cementation period at 2h. The experimental design was done at five levels of the operating parameters which were the initial copper concentration, temperature,

W. Djoudi; F. Aissani-Benissad; S. Bourouina-Bacha

2007-01-01

62

Purification of phosphoric acid by minimizing iron, copper, cadmium and fluoride  

Microsoft Academic Search

Commercial phosphoric acid manufactured using wet process has been purified by minimizing the iron, cadmium, copper and fluoride content. Bentonite clay is found suitable for removal of humic acids and suspended materials from crude phosphoric acid. An attempt to minimize the iron content by the addition of potassium sulfate, calcium sulfate, sodium sulfate, individually; silicon dioxide+sodium carbonate+potassium sulfate, in combination,

Ahmed A. El-Asmy; Homam M. Serag; Mohammad A. Mahdy; Moustafa I. Amin

2008-01-01

63

Use of Cement Copper in an Iron-Copper-Carbon Powder Metallurgy Alloy.  

National Technical Information Service (NTIS)

An investigation was made of the substitution of cement copper powder for commercial copper powder in an Fe-7 pct Cu-1 pct C powder metallurgy alloy. Copper powders from six different commercial cementation operations were separately upgraded by screening...

R. L. Crosby D. H. Desy R. M. Doerr

1970-01-01

64

Integration of nonlinear dielectric barium strontium titanate with polycrystalline yttrium iron garnet  

SciTech Connect

Biaxially oriented nonlinear dielectric Ba{sub 0.6}Sr{sub 0.4}TiO{sub 3} (BST) films have been grown on polycrystalline ferrite yttrium iron garnet (YIG) substrates. We use a structurally and chemically compatible MgO buffer to improve the crystallinity of the BST on polycrystalline YIG substrates, where the biaxially oriented MgO is deposited by an ion-beam assisted-deposition technique. The biaxially oriented BST has a dielectric loss of less than 0.01 and a capacitance tunability of greater than 25{percent} at a direct current bias voltage of 40 V at room temperature. {copyright} {ital 1999 American Institute of Physics.}

Jia, Q.X.; Groves, J.R.; Arendt, P.; Fan, Y.; Findikoglu, A.T.; Foltyn, S.R. [Superconductivity Technology Center, Mail Stop K763, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Jiang, H. [NZ Applied Technologies, 150-C New Boston Street, Woburn, Massachusetts 01801 (United States); Miranda, F.A. [NASA Lewis Research Center, 21000 Brookpark Road, MS 54-5, Cleveland, Ohio 44135 (United States)

1999-03-01

65

A thermodynamic study of silica-saturated iron silicate slags in equilibrium with liquid copper  

NASA Astrophysics Data System (ADS)

The thermodynamic properties of silica-saturated iron silicate slags in equilibrium with liquid copper have been studied from oxygen partial pressure measurements in the temperature range from 1490 to 1580 K by means of a solid electrolyte galvanic cell. The following cells were used: Pt, Ni-NiO/O=/slag-Cu(l), Cr2O3, Pt; Pt, Fe-FeO/O=/slag-Cu(Fe sat.), Fe. A strong correlation was found between oxygen pressure and the copper content of the slag; the copper content increased from less than 1 pct near iron saturation to about 4 pct at an oxygen partial pressure of 7.2 x 10-3 Pa. A similar correlation was found between the ferric iron/total iron ratio and the oxygen pressure. The oxygen content in liquid copper decreased with increasing iron content in liquid copper and increased slightly near iron saturation. This behavior could be explained qualitatively by using the standard free energy of formation of FeO and the activities of components.

Oishi, Toshio; Kamuo, Morinori; Ono, Katsutoshi; Moriyama, Joichiro

1983-03-01

66

An experimental study for enhancing the catalytic effects of various copper forms on the oxidation of ferrous iron.  

PubMed

In this research the catalytic effect of copper compounds (ionic, oxide and oxide nanopowder) on the oxidation of ferrous iron by aeration was studied experimentally. When copper exists in solution, the oxidation rate of iron(II) will increase. The experimental results showed that the oxidation rate increases with an increasing copper concentration. From the experimental data it can be determined that the copper oxide nanopowder is the most effective for the oxidation reaction among the used copper forms. Aeration is the most economical oxidation method when water exhibits a high ferrous iron concentration. PMID:23530309

Babak, Manizhe Moradi Shahre; Goharrizi, Ataallah Soltani; Mirzaei, Mohammad; Roayaei, Emad

67

Arsenic-75 and cobalt-59 NMR study of the electron doped barium iron cobalt arsenide  

NASA Astrophysics Data System (ADS)

We report a systematic investigation of the local electronic, magnetic, and superconducting properties of the new iron-based high temperature superconductor Ba(Fe1-xCox) 2As2 (x = 0, 0.02, 0.04, 0.082) through the measurement of 75As and 59Co NMR (Nuclear Magnetic Resonance) lineshapes, Knight shift (K), and spin-lattice relaxation rate (1/T1). The 75As NMR lineshape of the undoped parent compound splits into two sets due to discrete values of hyperfine magnetic field Bchf = +/- 1.32 Tesla below the magnetic ordering temperature to the SDW (Spin Density Wave) state, TSDW. In contrast, for lightly Co doped samples with x = 0.02 and 0.04, the 75As and 59Co lineshapes become broad and featureless below TSDW, indicating that the ground state is no longer the commensurate SDW ordered state. The observed lineshape is consistent with an incommensurate SDW ordered state, or a commensurate state with large distribution of hyperfine field Bhf. In the optimally doped superconductor with x = 0.082 (T c = 22 K), we observe two types of As sites and three types of Co sites, respectively, as expected from a binomial distribution of Co dopants. We found no evidence for induced localized moments in the vicinity of Co dopants. This finding is in remarkable contrast with the case of Zn or Ni doped high Tc cuprates, and suggests that the fundamental physics of iron-based superconductors is different from that of cuprates. The temperature dependences of 75,59K and 75,59(1/ T1T) at both 75As and 59Co sites show that Ba(Fe1-xCo x)2As2 exhibits spin pseudo-gap like behavior down to ˜ 100 K for a broad Co concentration range. Below ˜ 100 K, we observe the enhancement of residual antiferromagnetic spin fluctuations associated with inter-band spin excitations between the hole and electron Fermi surfaces even for x = 0.082. This effect is suppressed in the overdoped sample with x = 0.099, and T c decreases. Therefore, we suggest that antiferromagnetic spin fluctuations play a crucial role in the superconducting mechanism of Ba(Fe1- xCox)2As2. We also demonstrate that the superconductivity arises from a novel electronic state with spin susceptibility chis ˜ constant and in-plane resistivity rhoab ˜ T, which is not consistent with canonical Fermi-liquid behavior.

Ning, Fanlong

68

IN-HOUSE CORROSION RESEARCH EMPHASIZING LEAD, COPPER AND IRON  

EPA Science Inventory

Lead and copper are directly regulated via the "Lead and Copper Rule;" however, water suppliers must balance all water treatment processes in order to simultaneously comply with all regulations. Specific research needs for copper and lead chemistry still exist, as applications o...

69

Diel cycles in dissolved barium, lead, iron, vanadium, and nitrite in a stream draining a former zinc smelter site near Hegeler, Illinois  

USGS Publications Warehouse

Diel variations in the concentrations of a number of constituents have the potential to substantially affect the appropriate sampling regimen in acidic streams. Samples taken once during the course of the day cannot adequately reflect diel variations in water quality and may result in an inaccurate understanding of biogeochemical processes, ecological conditions, and of the threat posed by the water to human health and the associated wildlife. Surface water and groundwater affected by acid drainage were sampled every 60 to 90. min over a 48-hour period at a former zinc smelter known as the Hegeler Zinc Superfund Site, near Hegeler, Illinois. Diel variations related to water quality in the aquifer were not observed in groundwater. Diel variations were observed in the temperature, pH, and concentration of dissolved oxygen, nitrite, barium, iron, lead, vanadium, and possibly uranium in surface water. Temperature, dissolved oxygen, nitrite, barium, lead, and uranium generally attained maximum values during the afternoon and minimum values during the night. Iron, vanadium, and pH generally attained minimum values during the afternoon and maximum values during the night. Concentrations of dissolved oxygen were affected by the intensity of photosynthetic activity and respiration, which are dependent upon insolation. Nitrite, an intermediary in many nitrogen reactions, may have been formed by the oxidation of ammonium by dissolved oxygen and converted to other nitrogen species as part of the decomposition of organic matter. The timing of the pH cycles was distinctly different from the cycles found in Midwestern alkaline streams and likely was the result of the photoreduction of Fe3+ to Fe 2+ and variations in the intensity of precipitation of hydrous ferric oxide minerals. Diel cycles of iron and vanadium also were primarily the result of variations in the intensity of precipitation of hydrous ferric oxide minerals. The diel variation in the concentrations of lead, uranium, and barium may have been affected by competition with Fe+2 for sorption sites on hydrous ferric oxide minerals. ?? 2010.

Kay, R. T.; Groschen, G. E.; Cygan, G.; Dupre, David, H. , D. H.

2011-01-01

70

Inhibition of copper-catalyzed cysteine oxidation by nanomolar concentrations of iron salts.  

PubMed

Problems caused by the presence of adventitious metals in buffers and reagents are well recognized in studies of metal-catalyzed oxidation reactions. In most cases, metal contamination leads to an increase in rate, and chelating agents are inhibitory. In the present study, however, the rate of copper-catalyzed oxidation of cysteine was found to be increased by buffer purification with Chelex resin or by addition of micromolar concentrations of the specific iron chelator desferrioxamine (DFO). These effects are attributable to inhibition of copper-catalyzed oxidation by adventitious iron. In purified buffer at pH 7.25, containing 0.4 microM copper, cysteine was oxidized at a rate of 32 microM/min. Addition of iron salts to this buffer caused a dose-related decrease in this rate, up to a maximum of 85%. A 50% decrease in rate was recorded at an iron concentration of only 11 nM. Other transition metals were without effect. Similar effects of purification or addition of DFO on the rate of cysteine oxidation were seen in Tris, glycylglycine, Mops, and Pipes buffers. Catalase decreased the rate of cysteine oxidation, but the sensitivity to iron was similar in the presence and absence of catalase. Copper-catalyzed oxidation of cysteamine and reduced glutathione was much less sensitive to inhibition by iron. Our results offer an explanation for the conflicting literature reports of the effects of chelating agents and catalase on cysteine oxidation, and emphasize the need for buffer purification or addition of DFO in studies concerned with the oxidation or cytotoxicity of this thiol. The exceptional sensitivity of copper-catalyzed cysteine oxidation to iron makes this an attractive system for monitoring the iron content of buffers, and may also have application for determining the free iron content of physiological fluids. PMID:14990354

Munday, Rex; Munday, Christine M; Winterbourn, Christine C

2004-03-15

71

Evolution of Microstructures During Austempering of Ductile Irons Alloyed with Manganese and Copper  

NASA Astrophysics Data System (ADS)

The influences of relatively high manganese (0.45 through 1.0 wt pct) and copper (0.56 through 1.13 wt pct) contents on microstructure development and phase transformation in three austempered ductile irons have been studied. The experimental ductile irons alloyed with copper and manganese are found to be practically free from intercellular manganese segregation. This suggests that the positive segregation of manganese is largely neutralized by the negative segregation of copper when these alloying elements are added in appropriate proportions. The drop in unreacted austenite volume (UAV) with increasing austempering temperature and time is quite significant in irons alloyed with copper and manganese. The ausferrite morphology also undergoes a transition from lenticular to feathery appearance of increasing coarseness with the increasing austempering temperature and time. SEM micrographs of the austempered samples from the base alloy containing manganese only, as well as copper plus manganese-alloyed irons, clearly reveal the presence of some martensite along with retained austenite and ferrite. X-ray diffraction analysis also confirms the presence of these phases. SEM examination further reveals the presence of twinned martensite in the copper plus manganese-alloyed samples. The possibility of strain-induced transformation of austenite to martensite during austempering heat treatment is suggested.

Dasgupta, Ranjan Kumar; Mondal, Dipak Kumar; Chakrabarti, Ajit Kumar

2013-03-01

72

Reduction of copper(II) by iron(II).  

PubMed

Laboratory and field investigations have clearly demonstrated the important role of reduced iron (Fe(II)) in reductive transformations of first-row transition metal species. However, interactions of Fe(II) and copper (Cu) are not clearly understood. This study examined the reduction of Cu(II) by Fe(II) in stirred-batch experiments at pH 5.2 and 5.5 as influenced by chloride (Cl-) concentration (0.002-0.1 M), initial metal concentration (0.1-9.1 mM), and reaction time (1-60 min) under anoxic conditions. Reduction of Cu(II) to Cu(I) by dissolved Fe(II) was rapid under all experimental conditions and the stability of the products explains the driving force for the redox reaction. Under conditions of low [Cl-] and high initial metal concentration, >40% of total Cu and Fe were removed from solution after 1 min, which accompanied formation of a brownish-red precipitate. X-ray diffraction (XRD) patterns of the precipitates revealed the presence of cuprite (Cu2O), a Cu(I) mineral, based on d-spacings located at 0.248, 0.215, 0.151, and 0.129 nm. Fourier transform infrared (FTIR) spectroscopy corroborated XRD data for the presence of Cu2O, with features located at 518, 625, and 698 cm(-1). Increasing [Cl-] stabilized the dissolved Cu(I) product against Cu2O precipitation and resulted in more Fe precipitated from solution (relative to Cu) that appears to be present as poorly crystalline lepidocrocite (gamma-FeOOH). This process may be important in anoxic soil environments, where dissolved Fe(II) levels can accumulate. PMID:16091606

Matocha, C J; Karathanasis, A D; Rakshit, S; Wagner, K M

2005-08-09

73

Iron, copper and zinc isotopic fractionation up mammal trophic chains  

NASA Astrophysics Data System (ADS)

There is a growing body of evidence that some non-traditional elements exhibit stable isotope compositions that are distinct in botanical and animal products, providing potential new tracers for diet reconstructions. Here, we present data for iron (Fe), copper (Cu) and zinc (Zn) stable isotope compositions in plants and bones of herbivores and carnivores. The samples come from trophic chains located in the Western Cape area and in the Kruger National Park in South Africa. The Fe, Cu and Zn isotope systematics are similar in both parks. However, local Cu, and possibly Zn, isotopic values of soils influence that of plants and of higher trophic levels. Between plants and bones of herbivores, the Zn isotope compositions are 66Zn-enriched by about 0.8‰ whereas no significant trophic enrichment is observed for Fe and Cu. Between bones of herbivores and bones of carnivores, the Fe isotope compositions are 56Fe-depleted by about 0.6‰, the Cu isotope compositions are 65Cu-enriched by about 1.0‰, and the Zn isotope compositions are slightly 66Zn-depleted by about 0.2‰. The isotopic distributions of the metals in the body partly explain the observed trophic isotopic systematics. However, it is also necessary to invoke differential intestinal metal absorption between herbivores and carnivores to account for the observed results. Further studies are necessary to fully understand how the Fe, Cu and Zn isotope values are regulated within the ecosystem's trophic levels, but the data already suggests significant potential as new paleodietary and paleoecological proxies.

Jaouen, Klervia; Pons, Marie-Laure; Balter, Vincent

2013-07-01

74

Urinary excretion of copper, zinc and iron with and without D-penicillamine administration in relation to hepatic copper concentration in dogs.  

PubMed

Hereditary copper-associated hepatitis in dogs resembles Wilson's disease, a copper storage disease in humans. Values for urinary copper excretion are well established in the diagnostic protocol of Wilson's disease, whereas in dogs these have not been evaluated. The objectives of this study were to characterize both basal and D-penicillamine induced urinary copper, zinc and iron excretion in dogs in relation to hepatic copper concentration. Beagles, Beagle-Bedlington terrier cross-breeds homozygous for the COMMD1 gene mutation that causes copper toxicosis, and Labrador retrievers with normal or increased hepatic copper concentrations were investigated. The hepatic copper phenotype was determined by histological evaluation of liver biopsies and measurement of the hepatic copper concentration by instrumental neutron activation analysis. Urinary excretion of copper, iron and zinc was measured via inductively coupled plasma optical emission spectrometry under basal conditions and after oral administration of a single dose (20mg/kg bodyweight) of the chelator D-penicillamine. There was a rapid increase in urinary excretion of copper and zinc, but not iron after D-penicillamine administration. This increase was not different between dogs with high or normal hepatic copper concentrations. D-penicillamine-induced urinary copper excretion and the copper/creatinine ratio did not correlate with hepatic copper concentrations in the dogs studied, although basal urinary copper/zinc ratios did correlate with hepatic copper concentrations in Labrador retrievers. The latter parameter may be useful in diagnostic and follow-up protocols for copper-associated hepatitis in Labrador retrievers. PMID:23583003

Fieten, H; Hugen, S; van den Ingh, T S G A M; Hendriks, W H; Vernooij, J C M; Bode, P; Watson, A L; Leegwater, P A J; Rothuizen, J

2013-04-09

75

Effects of static magnetic field on dissolved oxygen levels in aqueous solutions containing copper(II), iron(II), and heme iron(III) complexes  

Microsoft Academic Search

Trace metal ions like copper and iron play important roles such as binding, transport, and storage of molecular dioxygen in a wide variety of living systems. The effects of static magnetic fields on the dissolved oxygen (DO) levels in aqueous solutions containing copper(II), iron(II), and their bioligand complexes were investigated. The DO levels in aqueous solutions containing the stable copper(II)

Hiromu Sakurai; Hiroyuki Yasui; Keisuke Kunitomi; Masayuki Kamatari; Noritsugu Kaneko; Akihiro Nakayama

2000-01-01

76

Iron, zinc, and copper concentrations in breast milk are independent of maternal mineral status1-3  

Microsoft Academic Search

Background: Little is known about the regulation of iron, zinc, and copper in breast milk and the transport of these minerals across the mammary gland epithelium. Objective: The objective was to study associations between breast-milk concentrations of iron, zinc, and copper and maternal mineral status. Design: Milk samples from 191 Swedish and Honduran mothers were collected at 9 mo postpartum.

Magnus Domellöf; Bo Lönnerdal; Kathryn G Dewey; Roberta J Cohen; Olle Hernell

77

Chronic administration of iron and copper potentiates adipogenic effect of high fat diet in Wistar rats.  

PubMed

The primary objective of this research project is explore a possible adipogenic effect of iron and/or copper in albino Wistar rats kept on standard (STD) and high-fat (HFD) diets. The female Wistar rats in the study were divided into eight experimental groups (n = 6). Rats maintained on STD and HFD received 3 mg/l FeSO??7H?O, 4.88 mg/l CuSO? and a combination of 1.5 mg/l FeSO??7H?O and 2.44 mg/l CuSO? with drinking water. Control groups were kept on STD and HFD and received pure water without metal salts. Consumption of iron and copper in the groups of rats maintained on an STD did not produce a significant increase in weight, adipose tissue content or body mass index. However, the adipocyte size and infiltration were increased in the adipose tissue of STD-fed rats receiving a mixture of iron and copper with drinking water. The rats fed iron and copper and, especially, their combination on a HFD background had a significantly higher weight gain, adipose tissue content, morphometric parameters values and adipocyte size compared to STD- and HFD-fed controls. Iron and copper consumption produced their accumulation in the rats' adipose tissue. Moreover, the studied metals reduced adipose tissue concentration of chromium and vanadium. The lipoprotein profile and serum oxidative stress biomarkers were affected in the rats receiving the metals and STD. Hyperglycemia was observed in the rats receiving the studied metals on HFD-background. Based on the analysis of the test subjects, the study suggests that iron and copper administration, especially combined, may potentiate adipogenic effect of HFD. PMID:23657865

Tinkov, Alexey A; Polyakova, Valentina S; Nikonorov, Alexandr A

2013-05-09

78

Increased serum copper and decreased serum zinc levels in children with iron deficiency anemia  

Microsoft Academic Search

In order to evaluate serum copper and zinc status in children with iron deficiency anemia (IDA), 60 children with IDA aged\\u000a 1–14 yr and 64 healthy children as controls aged 1–14 yr were included the study. Serum copper levels were higher in children\\u000a with IDA (189 ± 49 (?g\\/dL) than those of controls (163 ± 37 ?g\\/dL) (p = 0.001).

Aydin Ece; Bekir Sami Uyamik; Akin I?can; Pelin Ertan; M. Ramazan Yi?itolu

1997-01-01

79

Altered Serum Iron and Copper Homeostasis Predicts Cognitive Decline in Mild Cognitive Impairment  

PubMed Central

Alzheimer’s disease (AD) brain is marked by severe neuronal death which has been partly attributed to increased oxidative stress. The pathophysiology accounting for this free radical injury is not well-delineated at this point, but one hypothesis is that a derangement in transition metal metabolism contributes to the process. We tested the hypothesis that peripheral derangement of transition metal metabolism is present early in the dementing process. We analyzed non-heme iron and copper levels in serum from subjects with normal cognition, mild cognitive impairment, and early stage senile dementia and followed these subjects over 5 years. An increase in the ratio of serum copper to non-heme iron levels predicted which subjects with mild cognitive impairment would progress to dementia versus those that would remain cognitively stable. This increase did not correlate with changes in expression of iron regulatory protein 2 or selected downstream targets in peripheral lymphocytes. A cDNA-based microarray (IronChip) containing genes relevant to iron and copper metabolism was used to assess transition metal metabolism in circulating lymphocytes from cognitively normal and demented subjects. No gene was identified as being dysregulated more than 2-fold, and verification using quantitative RT-PCR demonstrated no significant changes in expression for ALAS2, FOS, and CTR1. The increased ratio of serum copper to serum iron prior to dementia has potential as a biomarker for cognitive decline and mirrors other changes in serum previously reported by others, but iron and copper metabolism pathways appear to be broadly unaffected in peripheral blood in AD.

Mueller, Claudius; Schrag, Matthew; Crofton, Andrew; Stolte, Jens; Muckenthaler, Martina U.; Magaki, Shino; Kirsch, Wolff

2013-01-01

80

Experimental study of methanol synthesis catalysts containing copper plated iron fibers  

SciTech Connect

An experimental study was conducted which evaluated the performance of methanol synthesis catalysts containing copper plated, polycrystalline iron fibers. The active catalyst material was comprised of Cu/ZnO/Al/sub 2/O/sub 3/ with atomic ratio, Cu/Zn/Al = 6/3/1. It was necessary to copper plate the iron fibers since iron catalyzes the more thermodynamically favorable synthesis of methane from CO, CO/sub 2/, and H/sub 2/. A deposition by displacement method and an electroless method were examined for copper plating the iron fibers. A combination of the two methods was finally used which left less than 1% surface iron exposed as determined by Scanning Electron Microscopy and Energy Dispersive X-ray Analysis. Preliminary catalyst evaluations were conducted at 100 atm, feed gas composition = .904 H/sub 2//.068 CO/.028 CO/sub 2/, flow = 300 l/hr, and 250, 260, 270, 275, 280, and 290/sup 0/C. These conditions were changed in later evaluations to 80 atm, feed gas composition = .69 H/sub 2//.27 CO/.04 CO/sub 2/, flow = 28 l/hr, and 245, 255, 265, 275, 280, and 290/sup 0/C. The latter conditions were similar to those used by other investigators and by industry. The results of the final catalyst evaluations indicate that an improvement in performance is observed with catalysts supported with 5-10 weight percent copper plated, iron fibers. It is hypothesized that the copper plated iron fibers enhance catalyst performance by conducting thermal energy, resulting from the heat of reaction, away from the active catalytic site, thus lowering the temperature there, and creating a condition more thermodynamically favorable for methanol synthesis.

Bieser, A.L. Jr.

1983-01-01

81

Altered serum iron and copper homeostasis predicts cognitive decline in mild cognitive impairment.  

PubMed

Alzheimer's disease (AD) brain is marked by severe neuronal death which has been partly attributed to increased oxidative stress. The pathophysiology accounting for this free radical injury is not well-delineated at this point, but one hypothesis is that a derangement in transition metal metabolism contributes to the process. We tested the hypothesis that peripheral derangement of transition metal metabolism is present early in the dementing process. We analyzed non-heme iron and copper levels in serum from subjects with normal cognition, mild cognitive impairment, and early stage senile dementia and followed these subjects over 5 years. An increase in the ratio of serum copper to non-heme iron levels predicted which subjects with mild cognitive impairment would progress to dementia versus those that would remain cognitively stable. This increase did not correlate with changes in expression of iron regulatory protein 2 or selected downstream targets in peripheral lymphocytes. A cDNA-based microarray (IronChip) containing genes relevant to iron and copper metabolism was used to assess transition metal metabolism in circulating lymphocytes from cognitively normal and demented subjects. No gene was identified as being dysregulated more than 2-fold, and verification using quantitative RT-PCR demonstrated no significant changes in expression for ALAS2, FOS, and CTR1. The increased ratio of serum copper to serum iron prior to dementia has potential as a biomarker for cognitive decline and mirrors other changes in serum previously reported by others, but iron and copper metabolism pathways appear to be broadly unaffected in peripheral blood in AD. PMID:22232013

Mueller, Claudius; Schrag, Matthew; Crofton, Andrew; Stolte, Jens; Muckenthaler, Martina U; Magaki, Shino; Kirsch, Wolff

2012-01-01

82

State of adsorption layers of fatty acids on the surfaces of iron, manganese, and copper ferrites  

NASA Astrophysics Data System (ADS)

States of adsorbed substances in surface layers arising during the adsorption of oleic, linoleic, and linolenic acids from carbon tetrachloride, heptane, and cyclohexane solutions on the surfaces of iron, manganese, and copper ferrites, are investigated. Adsorption isotherms and two-dimensional state diagrams of surface layers of iron, manganese, and copper ferrites are obtained experimentally. It is shown that the adsorption of fatty acids from solutions in organic solvents proceeds via filling the volume of the ferrites' porous space with adsorption solutions, while the state of ferrite surface layers changes due to the structural rearrangement of adsorption solutions upon an increase in solute concentration.

Balmasova, O. V.; Ramazanova, A. G.; Korolev, V. V.

2012-07-01

83

Identification of copper ions in aqueous and vitreous of eyes containing copper and iron foreign bodies  

Microsoft Academic Search

The reliability of aqueous analysis by the atomic absorption spectrophotometer for copper ion content in samples from eyes containing intravitreal pure copper particles was investigated. It was demonstrated that values of copper ions rose well above the normal in the aqueous as well as in the vitreous of such eyes. The standard deviations of the mean values were generally high.

Y Yassur; H Zauberman; M Zidon

1975-01-01

84

[Iron, zinc and copper status in the elderly living in Warsaw district determined by hair analysis].  

PubMed

The aim of this study was to assess the iron, zinc and copper status of elderly people using hair trace element levels determined by using atomic absorption spectrophotometry (AAS). The samples of hair were taken in May-June 1999 from 73 people aged 75-80 years (50 men and 23 women) living in Warsaw district. The mean content of iron was 17.32 +/- 12.38 micrograms/g dry weight, zinc 176.44 +/- 64.33 micrograms/g d.w. and copper 11.25 +/- 6.32 micrograms/g d.w. Although these values were in range of reference intervals almost 40% of population had iron and zinc level below them, and for copper the result was even worse (50% of the elderly people). No significant differences between trace element content in hair of male and female have been observed. However it has revealed a trend that female hair contained less iron and more zinc than male hair. The mean copper level was similar for both sexes. It has been found that subject who had not excluded any food products from their diets had higher hair iron contents than those with some dietetic restrictions. PMID:11556095

Ka?uza, J; Jeruszka, M; Brzozowska, A

2001-01-01

85

Distribution behavior of cobalt, selenium, and tellurium between nickel-copper-iron matte and silica-saturated iron silicate slag  

Microsoft Academic Search

The distribution coefficients (D\\u000a X) of cobalt, selenium, and tellurium between nickel-copper-iron matte and silica-saturated iron silicate slag were determined\\u000a as a function of matte and slag compositions, temperature, and the partial pressure of oxygen. The effect of slag additives,\\u000a such as CaO, MgO, and Al2O3, on the distribution behavior of the minor elements was also investigated. Analysis of the

N. Choi; W. D. Cho

1997-01-01

86

Copper Cofire X7R Dielectrics and Multilayer Capacitors Based on Zinc Borate Fluxed Barium Titanate Ceramic  

Microsoft Academic Search

Copper cofired dielectrics may give new opportunities for high temperature capacitors. To demonstrate feasibility, BaTiO3 has been formulated into X7R dielectrics with copper inner electrodes. This requires the development of a formulation that permits sintering at temperatures below 1000°C, and then firing in a reducing environment in atmospheres pO2 ~ 10-8 atms. ZnO—B2O3 chemistries were explored with additional dopants to

Tae-Ho Song; Clive A. Randall

2003-01-01

87

Contribution of redox-active iron and copper to oxidative damage in Alzheimer disease  

Microsoft Academic Search

Metal-catalyzed hydroxyl radicals are potent mediators of cellular injury, affecting every category of macromolecule, and are central to the oxidative injury hypothesis of Alzheimer disease (AD) pathogenesis. Studies on redox-competent copper and iron indicate that redox activity in AD resides exclusively within the neuronal cytosol and that chelation with deferoxamine, DTPA, or, more recently, iodochlorhydroxyquin, removes this activity. We have

Rudy J Castellani; Kazuhiro Honda; Xiongwei Zhu; Adam D Cash; Akihiko Nunomura; George Perry; Mark A Smith

2004-01-01

88

COPPER DEFICIENCY REDUCES IRON ABSORPTION AND BIOLOGICAL HALF-LIFE IN MALE RATS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Dietary copper deficiency (CuD) in rats leads to iron (Fe) deficiency anemia. Is this because CuD reduces Fe absorption? Fe absorption in CuD rats was determined by feeding 59Fe and using whole-body counting (WBC) to assess the amount retained over time. Two groups, each with 45 male weanling rats, ...

89

Transport kinetics of zinc, copper, selenium, and iron in perfused human placental lobule in vitro  

Microsoft Academic Search

Transport characteristics of essential trace elements as zinc, copper, selenium and iron have been studied in maternal–fetal direction in normal pregnancies, using in vitro perfusion of human placental lobules. Solutions of trace elements corresponding to twice the physiological concentrations were injected (100 µl bolus) into the maternal arterial perfusate. Serial perfusate samples were collected every 30 sec from venous outflows

M. Nandakumaran; H. M. Dashti; E. Al-Saleh; N. S. Al-Zaid

2003-01-01

90

Iron and Copper Content of Non-Milk Products Commonly Used in Ice Cream  

Microsoft Academic Search

There is a lack of information on the iron and copper content of the non-dairy ingredients that commonly are used in conjunction with dairy products in the manufacture of ice cream. These materials include such products as stabilizers, emulsifying agents, sugar, cocoas, vanillas, chocolate liquors and coatings, and flavoring extracts. It is possible that one or more of these ingredients

Harry Pyenson; P. H. Tracy

1948-01-01

91

Comparative Effects of Copper, Iron, Vanadium and Titanium on Low Density Lipoprotein Oxidation in vitro  

Microsoft Academic Search

Introduction: Oxidation of low density lipoprotein (LDL) has been strongly implicated in the phathogenesis of atherosclerosis. The use of oxidants in dietary food stuff may lead to the production of oxidized LDL and may increase both the development and the progression of atherosclerosis. The present work investigated the effects of some elements including: copper (Cu), iron (Fe), vanadium (V) and

Mohsen Ani; Ali Asghar Moshtaghie; Hassan Ahmadvand

2007-01-01

92

DIETARY COPPER DEFICIENY REDUCES IRON ABSORPTION AND DUODENAL ENTEROCYTE HEPHAESTIN PROTEIN IN MALE AND FEMALE RATS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Dietary copper (Cu) deficiency reduces iron (Fe) in male rats, but whether this occurs in female rats has been questioned. The mechanism for reduced Fe absorption in Cu deficiency is unknown, but may involve the intestinal Cu-dependent ferroxidase Dephaestin (Hp). A 2 x 2 factorial experiment was de...

93

Charcoal remains from an Iron Age copper smelting slag heap at Feinan, Wadi Arabah (Jordan)  

Microsoft Academic Search

Charcoal remains were analysed from copper ore smelting at Khirbet en-Nahas, an Iron Age site in the region of Feinan between Wadi Arabah and the highland of Edom. For the first time, a section was dug into a stratified slag heap and separate charcoal samples were taken from each layer. Radiocarbon dates from the charcoal range from the 12th to

Thomas Engel

1993-01-01

94

Oxidative stress-mediated hepatotoxicity of iron and copper: Role of Kupffer cells  

Microsoft Academic Search

Iron- or copper-mediated catalysis leads to the generation of reactive oxygen species (ROS) that can attack biomolecules directly, with the consequent enhancement in membrane lipid peroxidation, DNA damage, and protein oxidation. Reactive nitrogen species (RNS) can also be formed, leading to nitration of aromatic structures in addition to the oxidative deterioration of cellular components. Kupffer cells, the resident macrophages of

Luis A. Videla; Virginia Fernández; Gladys Tapia; Patricia Varela

2003-01-01

95

Relation between anemia and blood levels of lead, copper, zinc and iron among children  

Microsoft Academic Search

BACKGROUND: Anemia is a health problem among infants and children. It is often associated with a decrease in some trace elements (iron, zinc, copper) and an increase in heavy metals as lead. This study was done to determine the association of blood lead level > 10 ?g\\/dl, with the increased risk to anemia, also, to investigate the relationship between anemia

Amal A Hegazy; Manal M Zaher; Manal A Abd el-hafez; Amal A Morsy; Raya A Saleh

2010-01-01

96

IRON ABSORPTION AND INTESTINAL HEPHAESTIN PROTEIN IN COPPER-DEFICIENT RATS  

Technology Transfer Automated Retrieval System (TEKTRAN)

More than 100 years ago, a connection between copper (Cu) and iron (Fe) metabolism was established when some forms of anemia were found to respond to treatment with Cu but not Fe. It was later discovered that the Cu-dependent plasma ferroxidase, ceruloplasmin, was associated with Fe homeostasis. Cu ...

97

Gas tungsten arc welding of nickel-copper to nickel-chromium-iron. Welding procedure specification  

Microsoft Academic Search

Procedure WPS-2303-ASME-3 is qualified under Section IX of the ASME Boiler and Pressure Vessel Code for gas tungsten arc welding of nickel-copper N04400 (P-42) to nickel-chromium-iron N06600 (P-43), in thickness of 0.035 to 0.432 inch; filler metal is ERNiCu-7 (F-42); shielding gas is argon.

C. H. Wodtke; D. R. Frizzell; W. A. Plunkett

1985-01-01

98

Gas Tungsten Arc Welding of Nickel-Copper to Nickel-Chromium-Iron. Welding Procedure Specification.  

National Technical Information Service (NTIS)

Procedure WPS-2303-ASME-3 is qualified under Section IX of the ASME Boiler and Pressure Vessel Code for gas tungsten arc welding of nickel-copper N04400 (P-42) to nickel-chromium-iron N06600 (P-43), in thickness of 0.035 to 0.432 inch; filler metal is ERN...

C. H. Wodtke D. R. Frizzell W. A. Plunkett

1985-01-01

99

Gas tungsten arc welding of nickel-copper to nickel-chromium-iron. Welding procedure specification  

SciTech Connect

Procedure WPS-2303-ASME-3 is qualified under Section IX of the ASME Boiler and Pressure Vessel Code for gas tungsten arc welding of nickel-copper N04400 (P-42) to nickel-chromium-iron N06600 (P-43), in thickness of 0.035 to 0.432 inch; filler metal is ERNiCu-7 (F-42); shielding gas is argon.

Wodtke, C.H.; Frizzell, D.R.; Plunkett, W.A.

1985-08-01

100

Removal of copper from iron-based metal with an aluminum sulfide/ferrous sulfide matte  

NASA Astrophysics Data System (ADS)

An economically viable method for the removal of copper from iron, if available, could be used by steelmakers to turn high-copper-content scrap (above 0.1 wt.%) into useful products. Molten salt mixtures of charge-asymmetric cation species show a significant drop in the activity coefficient for monovalent cation species in the presence of trivalent or higher cation species. This phenomenon can be used to design a flux for the removal of copper as a cuprous species (monovalent) from iron-based metal. Distribution coefficients of copper (i.e., the ratio of the weight percent copper in a matte to that in the metal) were determined between a sulfide flux (containing aluminum sulfide, ferrous sulfide, and dilute concentrations of either magnesium sulfide or calcium sulfide) and carbon-saturated iron at 1,638 K. A maximum distribution coefficient of 30 ± 5 was found, and the copper level in the iron was reduced to as low as 0.07 wt.%. Magnesium sulfide and calcium sulfide both adversely affected the copper removal. The activity coefficient of cuprous sulfide dropped from 2.9 with a pure FeS matte to 0.4 with a binary matte containing XsbFeS = 0.18. The decrease with increasing concentrations of aluminum sulfide was due to the presence of the polyvalent aluminum cation in the flux. A liquid-liquid miscibility gap above XsbFeS = 0.43 was confirmed in the aluminum sulfide/ferrous sulfide pseudobinary system. Because a sulfide matte would result in a large sulfur content in the treated metal, distribution coefficients were also determined between an oxide flux (consisting of alumina, silica, calcia, and ferrous oxide) and iron with various concentration of carbon at 1,923 K. A maximum distribution coefficient of 0.5 was found. Finally, distribution coefficients were determined between a sulfide-modified oxide flux (consisting of alumina, silica, ferrous sulfide, and dilute amounts of calcia, magnesia, calcium sulfide, or magnesium sulfide) and iron with various concentrations of carbon at 1,823 K. A maximum distribution coefficient of 6.8 was found for iron with 0.1 wt.% carbon; distribution coefficients increased as carbon content decreased. Although the results are considered preliminary, further research with the mixed flux is strongly recommended because significantly higher distribution coefficients should be possible.

Cohen, Adam Barrett

101

Zinc, copper, iron, and chromium concentrations in young patients with type 2 diabetes mellitus.  

PubMed

Homeostasis of trace elements can be disrupted by diabetes mellitus. On the other hand, disturbance in trace element status in diabetes mellitus may contribute to the insulin resistance and development of diabetic complications. The aim of present study was to compare the concentration of essential trace elements, zinc, copper, iron, and chromium in serum of patients who have type 2 diabetes mellitus (n = 20) with those of nondiabetic control subjects (n = 20). The serum concentrations of zinc, copper, iron, and chromium were measured by means of an atomic absorption spectrophotometer (Shimadzu AA 670, Kyoto, Japan) after acid digestion. The results of this study showed that the mean values of zinc, copper, and chromium were significantly lower in the serum of patients with diabetes as compared to the control subjects (P < 0.05). Our results show that deficiency of some essential trace elements may play a role in the development of diabetes mellitus. PMID:22351156

Basaki, M; Saeb, M; Nazifi, S; Shamsaei, H A

2012-02-21

102

In-situ formation of barium ferrite in iron-doped “tetragonal tungsten bronze”: Elaboration of room temperature multiferroic composites  

NASA Astrophysics Data System (ADS)

Recent studies of ceramics of formula Ba2LnFeNb4O15 (Ln=rare earth) with the “tetragonal tungsten bronze” (TTB) structure have correlated their room temperature multiferroics properties to the occurrence of barium ferrite parasitic phases. This work presents the elaboration of Ba2LaFeNb4O15 and Ba2EuFeNb4O15 composite samples with an excess of hematite in the TTB nominal composition. The influence of crystal-chemistry on the phase content and properties of Ba2LnFeNb4O15 TTB composites is discussed. A particular focus on the mechanisms related to the in-situ formation of barium ferrite is given. We show that we can control the spurious ferrite phase in TTB multiferroic composites and thus modulate their magnetic response.

Castel, E.; Josse, M.; Roulland, F.; Michau, D.; Raison, L.; Maglione, M.

2009-06-01

103

Barium-doped iron oxide pigments for high-density magnetic recording. Thermal stability and magnetic properties  

Microsoft Academic Search

Magnetic particles of barium surface-doped gamma-Fe2O3 and Co-gamma-Fe2O3 were prepared from oxalic precursors to obtain the required morphological and magnetic characteristics for high density magnetic recording. The role of the alkaline-earth ions was studied, especially as they affect morphological and magnetic characteristics, along with the thermal and chemical stabilities of the products. By several methods of analysis, it has been

Ch. Sarda; Ch. Bonino; P. Mollard; A. Rousset

1992-01-01

104

Zinc Pyrithione Inhibits Yeast Growth through Copper Influx and Inactivation of Iron-Sulfur Proteins?†  

PubMed Central

Zinc pyrithione (ZPT) is an antimicrobial material with widespread use in antidandruff shampoos and antifouling paints. Despite decades of commercial use, there is little understanding of its antimicrobial mechanism of action. We used a combination of genome-wide approaches (yeast deletion mutants and microarrays) and traditional methods (gene constructs and atomic emission) to characterize the activity of ZPT against a model yeast, Saccharomyces cerevisiae. ZPT acts through an increase in cellular copper levels that leads to loss of activity of iron-sulfur cluster-containing proteins. ZPT was also found to mediate growth inhibition through an increase in copper in the scalp fungus Malassezia globosa. A model is presented in which pyrithione acts as a copper ionophore, enabling copper to enter cells and distribute across intracellular membranes. This is the first report of a metal-ligand complex that inhibits fungal growth by increasing the cellular level of a different metal.

Reeder, Nancy L.; Kaplan, Jerry; Xu, Jun; Youngquist, R. Scott; Wallace, Jared; Hu, Ping; Juhlin, Kenton D.; Schwartz, James R.; Grant, Raymond A.; Fieno, Angela; Nemeth, Suzanne; Reichling, Tim; Tiesman, Jay P.; Mills, Tim; Steinke, Mark; Wang, Shuo L.; Saunders, Charles W.

2011-01-01

105

Fabrication of a nanocomposite from in situ iron nanoparticle reinforced copper alloy.  

PubMed

In situ iron nanoparticle reinforced Cu-3Sn-8Zn-6Pb alloy has been fabricated by centrifugal casting in a vacuum chamber with a medium frequency electrical furnace. The microstructure of this alloy was analyzed with a scanning electron microscope (SEM) and a high-resolution transmission electron microscope (HRTEM), and the results show that the grains of Cu-3Sn-8Zn-6Pb alloy without iron have a typical dendrite structure with dimensions from 500 to 1500 microm, and the grains of the alloy with the addition of 1% iron are small and equiaxed, with dimensions from 20 to 60 microm. Then, the relatively uniform dispersed particles in the copper matrix were identified with the HRTEM to be pure iron with dimensions in the order of 2-20 nm. The mechanical properties of the alloys were measured and the results show a significant increase in the tensile strength of the alloy with iron nanoparticles and a slight increase of the elongation compared to that without iron. The mechanism of formation of the iron nanoparticles was analyzed by thermodynamic and dynamic theories, and the results indicate that the in situ iron nanoparticles of Cu-3Sn-8Zn-6Pb alloy can reasonably form during solidification in the centrifugal casting technique. PMID:19417426

Wang, Zidong; Wang, Xuewen; Wang, Qiangsong; Shih, I; Xu, J J

2009-01-26

106

Microstructure and electrical properties of Mn-doped barium strontium titanate thin films prepared on copper foils  

Microsoft Academic Search

Ba0.7?xSr0.3MnxTiO3 (x=0, 0.025, 0.05) thin films have been prepared on copper foils using sol–gel method. The films were processed in an atmosphere with low oxygen pressure so that the substrate oxidation is avoided and the formation of the perovskite phase is allowed. XRD and SEM results showed that Mn doping enhanced the crystallization of the perovskite phase in the films.

Yanhua Fan; Shuhui Yu; Rong Sun; Lei Li; Yansheng Yin; Ka-Wai Wong; Ruxu Du

2010-01-01

107

Relation between anemia and blood levels of lead, copper, zinc and iron among children  

PubMed Central

Background Anemia is a health problem among infants and children. It is often associated with a decrease in some trace elements (iron, zinc, copper) and an increase in heavy metals as lead. This study was done to determine the association of blood lead level > 10 ?g/dl, with the increased risk to anemia, also, to investigate the relationship between anemia and changes in blood iron, zinc and copper levels, and measure lead level in drinking water. The study is a cross-sectional performed on 60 children. Venous blood samples were taken from the studied population for estimating hematological parameters as well as iron and ferritin levels. The concentrations of zinc, copper, and lead were measured. The studied population was divided into anemic and non-anemic (control) groups. The anemic group was further classified into mild, moderate and severe anemia. The study subjects were also categorized into low and high blood lead level groups. Findings Approximately 63.33% of children had blood lead levels ? 10 ?g/dl. At the blood lead level range of 10-20 ?g/dl, a significant association was found for mild and severe anemia. The blood level of iron and ferritin was found to be significantly lower in high blood lead level and anemic groups than those of the low blood lead level and control groups. Lead level in drinking water was higher than the permissible limit. Conclusion Lead level ? 10 ?g/dl was significantly associated with anemia, decreased iron absorption and hematological parameters affection. High blood lead levels were associated with low serum iron and ferritin. Lead level in drinking water was found to be higher than the permissible limits.

2010-01-01

108

Ultrasonic recovery of copper and iron through the simultaneous utilization of Printed Circuit Boards (PCB) spent acid etching solution and PCB waste sludge.  

PubMed

A method was developed to recover the copper and iron from Printed Circuit Boards (PCB) manufacturing generated spent acid etching solution and waste sludge with ultrasonic energy at laboratory scale. It demonstrated that copper-containing PCB spent etching solution could be utilized as a leaching solution to leach copper from copper contained PCB waste sludge. It also indicated that lime could be used as an alkaline precipitating agent in this method to precipitate iron from the mixture of acidic PCB spent etching solution and waste sludge. This method provided an effective technique for the recovery of copper and iron through simultaneous use of PCB spent acid solution and waste sludge. The leaching rates of copper and iron enhanced with ultrasound energy were reached at 93.76% and 2.07% respectively and effectively separated copper from iron. Followed by applying lime to precipitate copper from the mixture of leachate and rinsing water produced by the copper and iron separation, about 99.99% and 1.29% of soluble copper and calcium were settled as the solids respectively. Furthermore the settled copper could be made as commercial rate copper. The process performance parameters studied were pH, ultrasonic power, and temperature. This method provided a simple and reliable technique to recover copper and iron from waste streams generated by PCB manufacturing, and would significantly reduce the cost of chemicals used in the recovery. PMID:20932641

Huang, Zhiyuan; Xie, Fengchun; Ma, Yang

2010-09-16

109

Direct Functionalization of (Un)protected Tetrahydroisoquinoline and Isochroman under Iron and Copper Catalysis: Two Metals, Two Mechanisms  

PubMed Central

A highly facile, straightforward synthesis of 1-(3-indolyl)-tetrahydroisoquinolines was developed using either simple copper or iron catalysts. N-protected and unprotected tetrahydroisoquinolines (THIQ) could be used as starting materials. Extension of the substrate scope of the pronucleophile from indoles to pyrroles and electron-rich arenes was realized. Additionally, methoxyphenylation is not limited to THIQ but can be carried out on isochroman as well, again employing iron and copper catalysis.

2011-01-01

110

Exploration of the copper-related compensatory response in the Belgrade rat model of genetic iron deficiency.  

PubMed

The Menkes copper ATPase (Atp7a) and metallothionein (Mt1a) are induced in the duodenum of iron-deficient rats, and serum and hepatic copper levels increase. Induction of a multi-copper ferroxidase (ceruloplasmin; Cp) has also been documented. These findings hint at an important role for Cu during iron deficiency. The intestinal divalent metal transporter 1 (Dmt1) is also induced during iron deficiency. The hypothesis that Dmt1 is involved in the copper-related compensatory response during iron deficiency was tested, utilizing a mutant Dmt1 rat model, namely the Belgrade (b/b) rat. Data from b/b rats were compared with phenotypically normal, heterozygous +/b rats. Intestinal Atp7a and Dmt1 expression was increased in b/b rats, whereas Mt1a expression was unchanged. Serum and liver copper levels did not increase in the Belgrades nor did Cp protein or activity. The lack of fully functional Dmt1 may thus partially blunt the compensatory response to iron deficiency by 1) decreasing copper levels in enterocytes, as exemplified by a lack of Mt1a induction and a lesser induction of Atp7a, 2) abolishing the frequently described increase in liver and serum copper, and 3) attenuating the documented increase in Cp expression and activity. PMID:21852364

Jiang, Lingli; Ranganathan, Perungavur; Lu, Yan; Kim, Changae; Collins, James F

2011-08-18

111

Generation of oxidant response to copper and iron nanoparticles and salts: Stimulation by ascorbate  

PubMed Central

The present work describes a two-stage approach to analyzing combustion-generated samples for their potential to produce oxidant stress. This approach is illustrated with the two commonly encountered transition metals, copper and iron. First, their abilities to generate hydroxyl radical were measured in a cell-free, phosphate-buffered saline solution containing ascorbate and/or citrate. Second, their abilities to induce heme oxygenase-1 in cultured human epidermal keratinocytes were assessed in cell culture. Combustion-generated copper oxide nanoparticles were active in both assays and were found to be soluble in culture medium. Depletion of glutathione in the cells or loading the cells with ascorbate greatly increased heme oxygenase-1 induction in the presence of copper. By contrast, iron oxide nanoparticles were active in the phosphate buffered saline but not in cell culture, and they aggregated in culture medium. Soluble salts of copper and iron exhibited the same contrast in activities as the respective combustion-generated particles. The results suggest that the capability of combustion-generated environmental samples to produce oxidant stress can be screened effectively in a two step process, first in phosphate buffered saline with ascorbate and subsequently in epithelial cell culture for those exhibiting activity initially. The results also point to an unanticipated interaction in cells of oxidant stress-generating metals with an anti-oxidant (ascorbate) that is usually missing in culture medium formulations. Thus, ascorbate supplementation of cultured human cells is likely to improve their ability to model the in vivo effects of particulate matter containing copper and other redox-active metals.

Rice, Robert H.; Vidrio, Edgar A.; Kumfer, Benjamin M.; Qin, Qin; Willits, Neil H.; Kennedy, Ian M.; Anastasio, Cort

2009-01-01

112

Generation of oxidant response to copper and iron nanoparticles and salts: Stimulation by ascorbate.  

PubMed

The present work describes a two-stage approach to analyzing combustion-generated samples for their potential to produce oxidant stress. This approach is illustrated with the two commonly encountered transition metals, copper and iron. First, their abilities to generate hydroxyl radical were measured in a cell-free, phosphate-buffered saline solution containing ascorbate and/or citrate. Second, their abilities to induce heme oxygenase-1 in cultured human epidermal keratinocytes were assessed in cell culture. Combustion-generated copper oxide nanoparticles were active in both assays and were found to be soluble in culture medium. Depletion of glutathione in the cells or loading the cells with ascorbate greatly increased heme oxygenase-1 induction in the presence of copper. By contrast, iron oxide nanoparticles were active in the phosphate-buffered saline but not in cell culture, and they aggregated in culture medium. Soluble salts of copper and iron exhibited the same contrast in activities as the respective combustion-generated particles. The results suggest that the capability of combustion-generated environmental samples to produce oxidant stress can be screened effectively in a two step process, first in phosphate-buffered saline with ascorbate and subsequently in epithelial cell culture for those exhibiting activity initially. The results also point to an unanticipated interaction in cells of oxidant stress-generating metals with an antioxidant (ascorbate) that is usually missing in culture medium formulations. Thus, ascorbate supplementation of cultured human cells is likely to improve their ability to model the in vivo effects of particulate matter containing copper and other redox-active metals. PMID:19683516

Rice, Robert H; Vidrio, Edgar A; Kumfer, Benjamin M; Qin, Qin; Willits, Neil H; Kennedy, Ian M; Anastasio, Cort

2009-08-14

113

Determination of lead, copper, zinc, magnesium, calcium and iron in fresh eggs by atomic absorption spectrometry  

Microsoft Academic Search

In this study, lead, copper and zinc, calcium, magnesium and iron in fresh egg samples have been determined by electrothermal and flame atomic absorption spectrometry (ETAAS–FAAS) with Zeeman-effect background correction. Y+Pd+citric acid (CA) has been found a powerful modifier mixture for the determination of Pb, Cu and Zn. Maximum pyrolysis and optimum atomization temperatures of analyte elements were determined in

Ziya Kiliç; Orhan Acar; Mehmet Ula?an; Murat Ilim

2002-01-01

114

Direct observation of liquid-phase sintering in the system iron-copper  

Microsoft Academic Search

The hot-stage of a scanning electron microscope has been used to observe liquid-phase sintering in the system iron-copper. The densification behaviour of compacts of Fe and Cu particles were determined. The influence of particle size of both components and the amount of liquid phase developed were investigated. In samples with about 20 vol % liquid phase, the densification kinetics as

Leonhard Froschauer; Richard M. Fulrath

1975-01-01

115

Densification dynamics of copper and iron powder billets in hot shock compaction: Simulation and analysis  

Microsoft Academic Search

The paper presents the results from computer simulation and analysis of experimental data on the densification of copper and\\u000a iron powder billets during hot shock compaction. It is established for the first time that the shear viscosity of the porous\\u000a material matrix shows a stronger dependence on the initial impact velocity than the billet temperature does. The estimated\\u000a activation energy

M. S. Koval’chenko; L. F. Ochkas

2008-01-01

116

Tensile properties of copper alloyed austempered ductile iron: Effect of austempering parameters  

Microsoft Academic Search

A ductile iron containing 0.6% copper as the main alloying element was austenitized at 850 ?C for 120 min and was subsequently\\u000a austempered for 60 min at austempering temperatures of 270, 330, and 380 ?C. The samples were also austempered at 330 ?C for\\u000a austempering times of 30–150 min. The structural parameters for the austempered alloy austenite (X\\u000a \\u000a ?\\u000a ),

U. Batra; S. Ray; S. R. Prabhakar

2004-01-01

117

Evaluation of trace elements iron, zinc, copper and lead In the diet of female university students  

Microsoft Academic Search

Food consumption of 50 female students in Universiti Kebangsaan Malaysia was recorded for 7 days. Foods and drinks most frequently consumed were selected for analysis of iron, zinc, copper and lead content. The mean daily intakes of energy, protein, carbohydrate and fat among the students are 6.5±1.4 MJ (1550±335 kcal), 59.8±18.5g. 227. 1±54.6 g and 46.0±11.5 g respectively. This diet

Zawiah Hashim

118

Effect of austempering heat treatment on fracture toughness of copper alloyed gray iron  

Microsoft Academic Search

Austempering heat treatment was applied to gray cast iron in order to study the effect of matrix toughening on fracture mechanics behavior. Copper alloying was applied to increase the hardenability of the metal. The as-cast material was austenitized at 900°C for 1.5h, and then austempered at 300°C\\/3h or 360°C\\/2h so as to obtain different matrix morphology, namely, lower ausferrite or

Cheng-Hsun Hsu; Yih-Hsun Shy; Yuan-Hsin Yu; Shen-Chih Lee

2000-01-01

119

Magnetic properties of alloys containing mischmetal, cobalt, copper, iron, and magnesium. Report of investigations\\/1981  

Microsoft Academic Search

The Bureau of Mines investigated alloys containing mischmetal (MM), cobalt, copper, magnesium, and iron for use in permanent magnets in place of the scarce samarium-cobalt alloys. The magnetic properties of MM-Co, MM-Co-Cu, MM-Co-Cu-Mg, and MM-Co-Cu-Fe-Mg alloys were evaluated. Magnets were fabricated by powder metallurgy consisting of arc-melting the metals, crushing and grinding the resultant alloys, alining and compacting the powder,

J. W. Walkiewicz; J. S. Winston; M. M. Wong

1981-01-01

120

Copper and iron substituted hydrotalcites: properties and catalyst precursors for methylamines synthesis  

Microsoft Academic Search

Layered double hydroxides (LDHs) in which magnesium was partially substituted by copper or iron in the hydrotalcite-like layer were synthesized by a coprecipitation method. The effects of the substitution on the physicochemical properties of the samples were studied by using various techniques such as X-ray diffraction (XRD), X-ray fluorescence (XRF), N2 adsorption, scanning electron microscopy (SEM), thermogravimetry (TGA), X-ray photoelectron

Gabriela Carja; Ryuichi Nakamura; Hiroo Niiyama

2002-01-01

121

Effects of Copper and Malleablizing Time on Mechanical Properties of Austempered Malleable Iron  

NASA Astrophysics Data System (ADS)

In this study, both the unalloyed and 1 wt pct copper alloyed white irons were successively treated with a duplex heating process consisting of malleablizing and austempering, and then the effects of copper and processing variables on microstructure and mechanical properties of the austempered malleable iron (AMI) were investigated. The results showed that AMI could effectively shorten malleablizing time to obtain the constituents of irregular graphite, acicular ferrite, and retained austenite in the microstructure. Moreover, 1 pct Cu-AMI had a higher retained austenite content than unalloyed AMI. This is because copper is an austenite stabilizer and acts to delay the start of the transformation into ausferrite. In the case of mechanical properties, AMI increased tensile strength (1083 to 1190 MPa) and impact toughness (16 to 22 J) by 2 to 3 times after 930 °C 20 hours malleablizing treatment as compared to as-cast (572 to 580 MPa and 5 to 6 J). In particular, 1 pct Cu-AMI had better performance than unalloyed AMI except for hardness. In comparison with conventional malleable irons, AMI was found to possess better tensile and impact properties.

Hsu, Cheng-Hsun; Lu, Jung-Kai; Chen, Fan-Shiong

2007-10-01

122

Retronasal perception and flavour thresholds of iron and copper in drinking water.  

PubMed

Drinking water flavour has a strong role in water quality perception, service satisfaction, willingness to pay and selection of water sources. Metallic flavours are often caused by the dissolved iron and copper, commonly found in groundwater or introduced to tap water by corroding infrastructure. Taste thresholds of iron and copper have been investigated by several studies; however, reported results and test methods vary considerably. This study determined the taste thresholds of ferrous and cuprous ions in room temperature reagent water by using the one-of-five test with multi-nation panellists in the United States. For ferrous and cuprous ions, individual thresholds ranged from 0.003 to >5 mg l(-1) and 0.035 to >5 mg l(-1), respectively. Population thresholds were determined by logistic regression and geometric mean methods as 0.031 and 0.05 mg l(-1) for ferrous ion, and 0.61 mg l(-1) for cuprous ion by both methods. The components of metallic sensation were investigated by use of nose-clips while panellists ingested iron and copper solutions. Results showed that metallic sensation has a significant odour component and should be treated as a flavour instead of a taste. Ferrous, cuprous and cupric ions also produced weak bitter and salty tastes as well as astringent mouthfeel. In comparison, ferric ion produced no sensation. PMID:21301110

Omur-Ozbek, Pinar; Dietrich, Andrea M

2011-03-01

123

Influence of orange juice in the levels and in the genotoxicity of iron and copper.  

PubMed

World consumption of natural juices is increasing as a consequence of the human search for a healthier life. The juice production industry, especially for orange juice, is expanding in several countries and particularly in Brazil. Despite scientific data reporting beneficial properties derived from juice consumption, some components of juices have been identified as mutagenic or carcinogenic. Carcinogenic or genotoxic effects may be mediated by the interaction of juice components with transition metals or by sub-products of juice auto-oxidation. In this study, the mutagenic potential of orange juice and two metallic agents used in dietary supplementation, FeSO(4) and CuSO(4), were investigated using the comet assay in mouse blood cells (in vivo). Both metal compounds were genotoxic for eukaryotic cells after 24h treatment at the doses used. Significant damage repair was observed after 48h of treatment with the same compounds. Orange juice had a modulating effect on the action of metallic sulfates. In the case of iron treatment, the presence of the orange juice had a preventive, but not restorative, effect. On the other hand, in the case of copper treatment, the effects were both preventive and restorative. PIXE (particle induced X-ray emission) analysis indicated a positive correlation between DNA damage and the hepatic levels of iron and a negative correlation between whole blood copper and DNA damage. A negative correlation between hepatic iron and whole blood copper content was also seen in the treatment with both ferrous and cupric sulfates. PMID:16263202

Franke, Silvia Isabel Rech; Prá, Daniel; Giulian, Raquel; Dias, Johnny Ferraz; Yoneama, Maria Lúcia; da Silva, Juliana; Erdtmann, Bernardo; Henriques, João Antonio Pêgas

2005-11-02

124

Synthesis of Yttrium BARIUM(2) COPPER(3) Oxygen (7-X) Superconducting Thin Films by Metalorganic Chemical Vapor Deposition  

NASA Astrophysics Data System (ADS)

Yttrium barium cuprate (YBCO) superconducting thin films have been synthesized by metalorganic chemical vapor deposition (MOCVD) on various substrates. The depositions were conducted in a vertical, high-speed rotating (0-2000 rpm) disk reactor which was designed and assembled by this purpose. The 2,2,6,6-tetramethyl-3,5-heptanedione metal chelates of Y, Ba, and Cu were used as precursors, which were transported by nitrogen carrier gas. Oxygen gas was introduced uniformly through the top of the reactor. The films were grown by three different processes. First, YBCO layers were deposited at 500^circ C on (100) YSZ and (100) SrTiO_3 . Post-deposition annealing treatments were performed in order to convert the materials to the superconducting phase. The observed morphologies and the superconducting transition temperatures depended on the annealing process. Films annealed at 980^circC for 18 min exhibited a smooth morphology and metallic characteristics, and had a very sharp transition width (<=q 2K), with onset and zero resistance values of 90 and 88K, respectively. Second, in situ growth of YBCO thin films was performed at a temperature of 800 ^circC. After deposition, the films were cooled down at a rate of 5^circ C/min under 1 atm of oxygen. X-ray diffraction data showed the films to be highly oriented with the c -axis perpendicular to the plane of the substrate. Four -point resistance measurement yielded T_ {c}(R=O) at 91.8K (Delta T_{c} = 2.2K) and 85K (DeltaT_ {c} = 7K) on (100) YSZ and (100) MgO substrates, respectively. Finally, dense YBCO thin films with mirror-like surfaces and well-developed c-axis textures were prepared in situ at a substrate temperature as low as 570^circC by plasma -enhanced MOCVD (PE-MOCVD). Nitrous oxide was remotely activated by a microwave discharge, and transported to the surface of the growing film as atomic oxygen. The films deposited on (100) SrTiO_3 and (100) YSZ attained zero resistance at 72K without further processing. The results of this study indicate that low -temperature in situ fabrication of high-quality high-T _{c} superconducting oxide films by PE-MOCVD is a very attractive thin-film deposition process for the technology of superconducting devices.

Noh, Daniel Dong-Wook

125

Source Assessment: Major Barium Chemicals.  

National Technical Information Service (NTIS)

This report summarizes data on air emissions from the production of major barium chemicals. Compounds studied include barium sulfide, barium carbonate, barium chloride, barium hydroxide, and barium sulfate. In order to evaluate potential environmental eff...

H. D. Troy R. B. Rezink

1978-01-01

126

SOURCE ASSESSMENT: MAJOR BARIUM CHEMICALS  

EPA Science Inventory

This report summarizes data on air emissions from the production of major barium chemicals. Compounds studied include barium sulfide, barium carbonate, barium chloride, barium hydroxide, and barium sulfate. In order to evaluate potential environmental effects the source severity,...

127

Two new barium-copper-ethylene glycol complexes: Synthesis and structure of BaCu(C[sub 2]H[sub 6]O[sub 2])[sub n](C[sub 2]H[sub 4]O[sub 2])[sub 2] (N = 3, 6)  

SciTech Connect

Two crystalline barium-copper-ethylene glycol complexes have been isolated and structurally characterized by single-crystal x-ray diffraction. The solution-phase complex has also been investigated as a molecular precursor for use in sol-gel synthesis of high-temperature superconductors. The first crystalline form has the formula BaCu(C[sub 2]H[sub 6]O[sub 2])[sub 6](C[sub 2]H[sub 4]O[sub 2])[sub 2] (1) and has been isolated directly from ethylene glycol solutions of the barium-copper salt. In this molecule, copper is coordinated to the four xygens of two ethylene glycolate ligands in a nearly square planar geometry. Barium is coordinated by three bidentate ethylene glycol molecules and three monodentate ethylene glycol molecules; the 9-fold coordination resembles a trigonal prism with each rectangular face capped. Copper and barium moieties do not share any ethylene glycol or glycolate oxygens; they are found by hydrogen bonding to form linear chains. The second crystal type has formula BaCu(C[sub 2]H[sub 6]O[sub 2])[sub 3](C[sub 2]H[sub 4]O[sub 2])[sub 2] (2). It was prepared via crystallization of the mixed-metal alkoxide from an ethylene glycol/methyl ethyl ketone solution. As for 1, the copper is coordinated to four oxygen atoms of two ethylene glycolate ligands in a nearly square planar arrangement. Barium is 8-coordinate in a distorted cubic geometry. It is coordinated to three bidentate ethylene glycol molecules and shares two of the oxygen atoms bound to the copper (one from each coordinated ethylene glycol) to form a discrete molecular barium-copper complex.

Love, C.P.; Page, C.J. (Univ. of Oregon, Eugene (United States)); Torardi, C.C. (Du Pont, Wilmington, DE (United States))

1992-05-13

128

Tensile properties of copper alloyed austempered ductile iron: Effect of austempering parameters  

NASA Astrophysics Data System (ADS)

A ductile iron containing 0.6% copper as the main alloying element was austenitized at 850 °C for 120 min and was subsequently austempered for 60 min at austempering temperatures of 270, 330, and 380 °C. The samples were also austempered at 330 °C for austempering times of 30 150 min. The structural parameters for the austempered alloy austenite (X ? ), average carbon content (C ? ), the product X ? C ? , and the size of the bainitic ferrite needle (d ? ) were determined using x-ray diffraction. The effect of austempering temperature and time has been studied with respect to tensile properties such as 0.2% proof stress, ultimate tensile strength (UTS), percentage of elongation, and quality index. These properties have been correlated with the structural parameters of the austempered ductile iron microstructure. Fracture studies have been carried out on the tensile fracture surfaces of the austempered ductile iron (ADI).

Batra, U.; Ray, S.; Prabhakar, S. R.

2004-10-01

129

A comparative study of thermal behavior of iron and copper nanofluids  

NASA Astrophysics Data System (ADS)

Nanofluids consist of nanoparticles dispersed in heat transfer carrier fluid and are typically used for enhancing thermal conductivity in devices and systems. This study investigated the synthesis of iron and copper nanoparticle-based thermal fluids prepared using a two-step process. Chemical precipitation was used for the synthesis of the powders, and ultrasonic irradiation was used to disperse the nanoparticles in the carrier fluid (ethylene glycol). The size distributions of the nanopowders in the carrier fluid were determined using dynamic light scattering resulting in average particle sizes of around 500 nm. The crystallite sizes of the powders were below 20 nm. Thus, both types of nanofluids are comparable with regard to crystallite size, particle size, and morphology resulting in a direct comparison of material properties and their effect on thermal conductivity of the nanofluids. A guarded hot parallel-plate method and dynamic tests were used to compare the thermal conductivities of the nanofluids. It was shown that thermal conductivity can be enhanced by up to 70% for copper nanofluids. It was also demonstrated that for a given particle concentration, copper nanofluids are superior in thermal conductivity compared to iron nanofluids.

Sinha, Kaustav; Kavlicoglu, Barkan; Liu, Yanming; Gordaninejad, Faramarz; Graeve, Olivia A.

2009-09-01

130

Responses of seedling growth and antioxidant activity to excess iron and copper in Triticum aestivum L.  

PubMed

The purpose of this study was to analyze phytotoxicity mechanism involved in root growth and to compare physiological changes in the leaves of wheat seedlings exposed to short term iron (Fe) and copper (Cu) stresses (0, 100, 300 and 500?M). All applied Fe or Cu concentrations reduced root and shoot lengths, but seed germination was inhibited by Cu only at 500?M. Analyses using fluorescent dye 2',7'-dichlorodihydrofluorescein diacetate indicated enhanced H(2)O(2) levels in seedling roots under Fe and Cu treatments. Cu stress at the same concentration induced a great reduction in cell viability and a strong damage on membrane lipid in the roots with respect to Fe treatment. Significant increases in the total chlorophyll (chl) content including chl a and chl b were observed in response to higher Fe concentrations, whereas the highest Cu concentration (500?M) led to significant decreases in the total chl content including chl a. Additionally, leaf peroxidase (POD) and ascorbate peroxidase (APX) were stimulated by Fe stress, but the highest Fe concentration exhibited inhibitory effect on leaf APX activity. In contrast, copper treatment resulted in an elevation in leaf catalase and POD activities. Therefore, H(2)O(2) content in the leaves associated with copper was significantly lower than that with iron at the same concentration. PMID:23025893

Li, Xiaoning; Ma, Haizhen; Jia, Pengxiang; Wang, Juan; Jia, Lingyun; Zhang, Tengguo; Yang, Yingli; Chen, Haijian; Wei, Xia

2012-09-29

131

Interactions of hydroxycarbamide (hydroxyurea) with iron and copper: implications on toxicity and therapeutic strategies.  

PubMed

Presented at the 19th International Conference on Chelation, London, UK, 13-16 November 2009 Preliminary spectrophotometric and potentiometric studies have shown that hydroxycarbamide or hydroxyurea (HU) can interact with copper(II) [Cu(II)], iron(II) [Fe(II)] and Fe(III) ions and form complexes, for example, a ratio of 1 HU:1 metal at pH 5. The affinity for Cu (log ?1 = 3.1) and Fe (log ?1 = 5) by HU is much lower than that of the Fe and Cu chelating drug deferiprone (L1), which is used for the treatment of iron overload. It is anticipated that under certain conditions of high concentrations of these metal ions such as in transfusional iron overload, the therapeutic, pharmacological and toxicological properties of HU could be affected. It is also suggested that excess chelatable and labile forms of Fe or Cu ions, such as non transferrin-bound iron (NTBI) or intracellular low molecular weight labile iron, are among the main factors that may cause variations in the therapeutic response to HU in cancer, sickle cell anemia, thalassemia intermedia and other groups of patients. Further studies are needed to clarify the interaction mechanisms of HU with metal ions in vitro, in vivo and in clinical conditions. PMID:21599436

Konstantinou, Eleni; Pashalidis, Ioannis; Kolnagou, Annita; Kontoghiorghes, George J

2011-01-01

132

Picosecond X-Ray Diffraction from Laser-Shocked Copper and Iron  

SciTech Connect

In situ X-ray diffraction allows the determination of the structure of transient states of matter. We have used laser-plasma generated X-rays to study how single crystals of metals (copper and iron) react to uniaxial shock compression. We find that copper, as a face-centred-cubic material, allows rapid generation and motion of dislocations, allowing close to hydrostatic conditions to be achieved on sub-nanosecond timescales. Detailed molecular dynamics calculations provide novel information about the process, and point towards methods whereby the dislocation density might be measured during the passage of the shock wave itself. We also report on recent experiments where we have obtained diffraction images from shock-compressed single-crystal iron. The single crystal sample transforms to the hcp phase above a critical pressure, below which it appears to be uniaxially compressed bcc, with no evidence of plasticity. Above the transition threshold, clear evidence for the hcp phase can be seen in the diffraction images, and via a mechanism that is also consistent with recent multi- million atom molecular dynamics simulations that use the Voter- Chen potential. We believe these data to be of import, in that they constitute the first conclusive in situ evidence of the transformed structure of iron during the passage of a shock wave.

Wark, J. S.; Hawreliak, J.; Higginbotham, A.; Rosolankova, K.; Sheppard, J. [Department of Physics, Clarendon Laboratory, Parks Road, University of Oxford, OX1 3PU (United Kingdom); Belak, J. F.; Collins, G. W.; Colvin, J. D.; Duchaineau, M.; Eggert, J. H.; Kalantar, D. H.; Lorenzana, H. E.; Remington, B. A.; Rudd, R. E.; Stolken, J. S. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Davies, H. M. [AWE Aldermaston, Reading (United Kingdom); Germann, T. C.; Holian, B. L.; Kadau, K.; Lomdahl, P. S. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)] (and others)

2006-07-28

133

Copper, iron and zinc absorption, retention and status of young women fed vitamin B-6 deficient diets  

SciTech Connect

A study was conducted in young women to determine the effect of vitamin B-6 deficient diets on copper, iron and zinc metabolism. Young women were confined to a metabolic research unit for 84 and 98 days. They were fed a vitamin B-6 deficient formula diet initially, followed by food diet containing four increasing levels of vitamin B-6. Copper, iron and zinc absorption, retention and status were determined at intervals throughout the study. Absorption was determined using the stable isotopes {sup 65}Cu, {sup 54}Fe, and {sup 67}Zn. Status was based on serum copper and zinc, hemoglobin, hematocrit and mean corpuscular volume. Copper absorption averaged 18 {plus minus} 1% during vitamin B-6 depletion, significantly lower than 24 {plus minus} 1% during repletion, but serum copper was not affected and balance was positive. Iron absorption was not impaired significantly by vitamin B-6 deficient diets, but status declined during the depletion period. Zinc absorption averaged 40 {plus minus} 2% during depletion and 27 {plus minus} 2% during repletion. Zinc absorption and retention were significantly greater during vitamin B-6 depletion, but serum zinc declined suggesting the absorbed zinc was not available for utilization. The results suggest that vitamin B-6 depletion of young women may inhibit copper absorption, affect iron status and alter zinc metabolism. The effects of vitamin B-6 depletion differ markedly among these elements.

Turnlund, J.R.; Keyes, W.R.; Hudson, C.A.; Betschart, A.A.; Kretsch, M.J.; Sauberlich, H.E. (USDA/ARS, San Francisco, CA (United States) Western Regional Research Center, Albany, CA (United States))

1991-03-11

134

Yttrium Barium Copper Oxide Thin Films and Josephson Weak Links: the Role of Oxygen Disorder and Vacancy Aggregation.  

NASA Astrophysics Data System (ADS)

This dissertation describes the highlights of several years' research into the materials and transport properties of rm YBa_2Cu_3O _{7-delta} thin films. These films are capable of supporting over 10^6 rm A/cm^2 of supercurrent at the temperature of liquid nitrogen. This feat is possible, however, only for films which are deposited on a handful of suitable substrate materials. I herein examine some of the complex structural characteristics of this high -T_{c} material which render somewhat tricky its growth on slightly non-lattice-matched substrates such as MgO. The materials properties of rm YBa_2Cu_3O_{7-delta }<=ad to the formation of myriad structural defects even in "high-quality" films (ironically, the high critical current densities are a result of the ability of these defects to "pin" magnetic vortices). However, due to the very short superconductive coherence lengths of these unusual materials, their superconductive properties are quite sensitive to these defects on a local scale. As a result, structural irregularities such as grain boundaries are capable of producing Josephson weak link behavior, one of the remarkable macroscopic quantum aspects of superconductivity. Depending on the application, such high-T_{c } weak links can be either nirvana or anathema. I will describe the results of our investigations into the non-ideal weak link properties of in-plane high-angle tilt grain boundaries and basal-plane-faced c-a tilt boundaries. An additional rather stunning property of rm YBa_2Cu_3O_{7-delta } is the very large degree to which its materials as well as normal-state and superconductive transport properties depend directly upon how oxygen is incorporated into its structure. I have found that the nonuniform and nonreproducible weak-link characteristics in our thin films may also be related to the probable inhomogeneous oxygen distribution. I have also shown that oxygen atoms residing on the basal -plane chain sites in the rm YBa_2Cu _3O_{7-delta} structure move easily in the presence of a small external electric field. This oxygen electromigration demonstrates interesting and unusual behavior, which I will describe.

Moeckly, Brian Harold

135

Manufactures and Characterizations of Photodiode Thin Film Barium Strontium Titanate (BST) Doped by Niobium and Iron as Light Sensor  

Microsoft Academic Search

Pure Ba0,5Sr0,5TiO3 (BST) thin film, BST doped by niobium (BNST) and BST doped by iron (BFST) have been synthesized on p-type Si (100) substrates using Chemical Solution Deposition (CSD) methods followed by spin coating and annealing techniques. Current-voltage characterizations on these sample result in agreement that all of the BST, BNST, and BFST thin films have photodiode properties. Electrical conductivity

Muhammad Dahrul; Heriyanto Syafutra; Ardian Arif; Irzaman; Muhammad Nur Indro; Siswadi

2010-01-01

136

Relationship between Paratuberculosis and the microelements Copper, Zinc, Iron, Selenium and Molybdenum in Beef Cattle.  

PubMed

To study the deficiency of minerals and its relationship with Paratuberculosis, blood, serum, and fecal samples were obtained from 75 adult bovines without clinical symptoms of the disease and from two bovines with clinical symptoms of the disease, from two beef herds with a previous history of Paratuberculosis in the Province of Buenos Aires, Argentina. Serum samples were processed by ELISA and feces were cultured in Herrolds medium. Copper, zinc and iron in serum were quantified by spectrophotometry and selenium was measured by the activity of glutathione peroxidase. We also determined copper, zinc, iron and molybdenum concentrations in pastures and the concentration of sulfate in water. Mycobacterium avium subsp paratuberculosis (Map) was isolated from 17.3% of fecal samples of asymptomatic animals and from the fecal samples from the two animals with clinical symptoms. All the Map-positive animals were also ELISA-positive or suspect, and among them, 84.6% presented low or marginal values of selenium and 69.2% presented low or marginal values of copper. The two animals with clinical symptoms, and isolation of Map from feces and organs were selenium-deficient and had the lowest activity of glutathione peroxidase of all the animals from both herds. All the animals negative to Map in feces and negative to ELISA had normal values of Se, while 13.8% of animals with positive ELISA or suspect and culture negative presented low levels of Se. Half of the animals that were negative both for ELISA and culture in feces were deficient in copper but none of them presented low values of selenium. The content of molybdenum and iron in pasture was high, 2.5 ppm and 1.13 ppm in one herd and 2.5 ppm and 2.02 ppm in the other, respectively, whereas the copper:molybdenum ratio was 1.5 and 5.2, respectively. These results do not confirm an interaction between imbalances of the micronutrients and clinical Paratuberculosis, but show evidence of the relationship between selenium deficiencies in animals with Map infection and ELISA positive results. PMID:24159298

Paolicchi, F; Perea, J; Cseh, S; Morsella, C

2013-05-17

137

Relationship between Paratuberculosis and the microelements Copper, Zinc, Iron, Selenium and Molybdenum in Beef Cattle  

PubMed Central

To study the deficiency of minerals and its relationship with Paratuberculosis, blood, serum, and fecal samples were obtained from 75 adult bovines without clinical symptoms of the disease and from two bovines with clinical symptoms of the disease, from two beef herds with a previous history of Paratuberculosis in the Province of Buenos Aires, Argentina. Serum samples were processed by ELISA and feces were cultured in Herrolds medium. Copper, zinc and iron in serum were quantified by spectrophotometry and selenium was measured by the activity of glutathione peroxidase. We also determined copper, zinc, iron and molybdenum concentrations in pastures and the concentration of sulfate in water. Mycobacterium avium subsp paratuberculosis (Map) was isolated from 17.3% of fecal samples of asymptomatic animals and from the fecal samples from the two animals with clinical symptoms. All the Map-positive animals were also ELISA-positive or suspect, and among them, 84.6% presented low or marginal values of selenium and 69.2% presented low or marginal values of copper. The two animals with clinical symptoms, and isolation of Map from feces and organs were selenium-deficient and had the lowest activity of glutathione peroxidase of all the animals from both herds. All the animals negative to Map in feces and negative to ELISA had normal values of Se, while 13.8% of animals with positive ELISA or suspect and culture negative presented low levels of Se. Half of the animals that were negative both for ELISA and culture in feces were deficient in copper but none of them presented low values of selenium. The content of molybdenum and iron in pasture was high, 2.5 ppm and 1.13 ppm in one herd and 2.5 ppm and 2.02 ppm in the other, respectively, whereas the copper:molybdenum ratio was 1.5 and 5.2, respectively. These results do not confirm an interaction between imbalances of the micronutrients and clinical Paratuberculosis, but show evidence of the relationship between selenium deficiencies in animals with Map infection and ELISA positive results.

Paolicchi, F.; Perea, J.; Cseh, S.; Morsella, C.

2013-01-01

138

Seasonal changes of zinc, copper, and iron in gilthead sea bream ( Sparus aurata ) fed fortified diets  

Microsoft Academic Search

Four groups of gilthead sea bream (Sparus aurata) were fed diets with additional metal contents: a basal diet (diet A) contained Zn at 60.9 ± 1.9 mg\\/kg diet, Cu at 3.9 ±\\u000a 0.9 mg\\/kg diet, and Fe at 138.3 ± 6.8 mg\\/kg diet; the other diets were supplemented with copper (20 mg\\/kg, diet B), iron (100\\u000a mg\\/kg, diet C), or

Emilio Carpeme; Rossella Serra; Maurizio Manera; Gloria Isani

1999-01-01

139

Contact Killing of Bacteria on Copper Is Suppressed if Bacterial-Metal Contact Is Prevented and Is Induced on Iron by Copper Ions  

PubMed Central

Bacteria are rapidly killed on copper surfaces, and copper ions released from the surface have been proposed to play a major role in the killing process. However, it has remained unclear whether contact of the bacteria with the copper surface is also an important factor. Using laser interference lithography, we engineered copper surfaces which were covered with a grid of an inert polymer which prevented contact of the bacteria with the surface. Using Enterococcus hirae as a model organism, we showed that the release of ionic copper from these modified surfaces was not significantly reduced. In contrast, killing of bacteria was strongly attenuated. When E. hirae cells were exposed to a solid iron surface, the loss of cell viability was the same as on glass. However, exposing cells to iron in the presence of 4 mM CuSO4 led to complete killing in 100 min. These experiments suggest that contact killing proceeds by a mechanism whereby the metal-bacterial contact damages the cell envelope, which, in turn, makes the cells susceptible to further damage by copper ions.

Mathews, Salima; Hans, Michael

2013-01-01

140

Austempering and austempered ductile iron microstructure in copper alloyed ductile iron  

Microsoft Academic Search

The variation in the austempered microstructure, the volume fraction of retained austenite, X?, the average carbon content of retained austenite, C?, their product X?C? and the size of bainitic ferrite needles with austempering temperature for 0.6% Cu alloyed ductile iron have been investigated\\u000a for three austempering temperatures of 270, 330, and 380 ?C for 60 min at each temperature after

Uma Batra; S. Ray; S. R. Prabhakar

2003-01-01

141

Rapid chemical synthesis of the barium ferrate super-iron Fe (VI) compound, BaFeO 4  

Microsoft Academic Search

An alternate rapid synthesis of BaFeO4 is demonstrated. Fe(VI) salts, including BaFeO4, are energetic cathode materials in super-iron batteries ranging from primary to secondary, and including aqueous and non-aqueous cells. Of the Fe(VI) salts, BaFeO4 sustains unusually facile charge transfer, of importance to the high power domain of alkaline batteries. Unlike previous syntheses, BaFeO4 preparation is demonstrated from all solid

Stuart Licht; Vera Naschitz; Baohui Wang

2002-01-01

142

Ferric iron uptake genes are differentially expressed in the presence of copper sulfides in Acidithiobacillus ferrooxidans strain LR  

Microsoft Academic Search

Acidithiobacillus ferrooxidans is one of the most widely used microorganisms in bioleaching operations to recover copper from low-grade copper sulfide ores.\\u000a This work aimed to investigate the relative expression of genes related to the iron uptake system when A. ferrooxidans LR was maintained in contact with chalcopyrite or bornite as the sole energy source. Real-time quantitative PCR analysis\\u000a revealed that

Lúcio F. C. Ferraz; Leandro C. L. Verde; Renato Vicentini; Ana P. Felício; Marcelo L. Ribeiro; Fabiana Alexandrino; Maria T. M. Novo; Oswaldo Garcia; Daniel J. Rigden; Laura M. M. Ottoboni

2011-01-01

143

Maternal-fetal status of copper, iron, molybdenum, selenium and zinc in insulin-dependent diabetic pregnancies  

Microsoft Academic Search

Objective: The objective was to assess the sta- tus of essential trace elements such as copper, iron, molybdenum, selenium and zinc in insulin-dependent diabetic pregnancies at term and to compare the data with a control group. Fetal-maternal ratios of the ele- ments and copper:zinc ratio were also computed in the control and study populations. Methodology: Samples from maternal vein, umbilical

Eyad Al-Saleh; Moorkath Nandakumaran; Majed Al-Shammari; Maasoumah Makhseed; Teena Sadan; Assem Harouny

2005-01-01

144

Copper  

MedlinePLUS

... form. Copper is often added to vitamin and mineral supplements. But most people are able to get ... arthritis. Today, many multivitamins and other herbal and mineral supplements include copper. What is the evidence? Copper ...

145

Temperature Dependences of Laser Induced Plasma Thresholds and Periodic Structures by Nanosecond Infrared Laser for Copper, Iron, and Chrome  

NASA Astrophysics Data System (ADS)

The temperature dependences of laser induced plasma thresholds for copper, iron, and chrome with linearly and circularly polarized pulses from a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser (wavelength 1064 nm, pulse width 4 ns) were evaluated at different temperatures from 123 to 423 K. The temperature dependence of copper with linearly polarized pulses was different from those of iron and chrome. On the other hand, the dependences of all materials with circularly polarized light showed the same tendency. The geometries of the ablated sites presented interesting tendencies, revealing some aspects of interaction between metal materials and laser that warrant further investigation.

Mikami, Katsuhiro; Motokoshi, Shinji; Fujita, Masayuki; Somekawa, Toshihiro; Jitsuno, Takahisa; Tanaka, Kazuo A

2012-06-01

146

Content of iron, copper and zinc in white sugar samples from Polish and other European sugar factories.  

PubMed

White sugar is a very pure food product, even though it contains very small, significant amounts of soluble and insoluble impurities. The content of these impurities has nutritional significance and determines the usefulness of sugar for various industrial applications. The aim was to evaluate the content of iron, copper and zinc in samples of white sugar from Polish factories compared with commercial white sugar samples from other European countries. The investigations were conducted on 72 campaign-averaged white sugar samples from 37 different Polish sugar factories from 1996 to 2000 and on 16 commercial white sugar samples from nine European countries. The content of iron, copper and zinc in those sugar samples was determined by means of FAAS both in the sediment and in the solution after filtration on 0.45- micro m filters of sugar water solution. The content of iron, copper and zinc was low (averages 0.29, 0.06 and 0.07 mg x kg(-1), respectively) in all the white sugar samples from Polish sugar factories and other European countries. Iron and copper found in all white sugar samples were mainly in insoluble form - 77 and 69%, respectively. The contents of water-insoluble iron and water-soluble zinc in white sugar increase with a lowering of the quality of sugar evaluated according to the standards of the EU sugar market regime. PMID:12443561

Wojtczak, M; Król, B

2002-10-01

147

Copper and iron concentrations in Ascophyllum nodosum (Fucales, Phaeophyta) from different sites in Ireland and after culture experiments in relation to thallus age and epiphytism  

Microsoft Academic Search

In laboratory experiments, copper concentrations in plants of Ascophyllum nodosum (L.) Le Jolis (Fucales, Phaeophyta) increased with the concentrations in the culture media and were highest in younger, meristematic thallus parts. After initial accumulation in high-copper medium and subsequent transfer to clean seawater for 5 days, no release of copper could be detected. Iron concentrations in A. nodosum tissue were

Dagmar B. Stengel; Matthew J. Dring

2000-01-01

148

Integrating naive Bayes models and external knowledge to examine copper and iron homeostasis in S. cerevisiae.  

PubMed

A novel suite of analytical techniques and visualization tools are applied to 78 published transcription profiling experiments monitoring 5,687 Saccharomyces cerevisiae genes in studies examining cell cycle, responses to stress, and diauxic shift. A naive Bayes model discovered and characterized 45 classes of gene profile vectors. An enrichment measure quantified the association between these classes and specific external knowledge defined by four sets of categories to which genes can be assigned: 106 protein functions, 5 stages of the cell cycle, 265 transcription factors, and 16 chromosomal locations. Many of the 38 genes in class 42 are known to play roles in copper and iron homeostasis. The 17 uncharacterized open reading frames in this class may be involved in similar homeostatic processes; human homologs of two of them could be associated with as yet undefined disease states arising from aberrant metal ion regulation. The Met4, Met31, and Met32 transcription factors may play a role in coregulating genes involved in copper and iron metabolism. Extensions of the simple graphical model used for clustering to learning more complex models of genetic networks are discussed. PMID:11120873

Moler, E J; Radisky, D C; Mian, I S

2000-12-18

149

Rapid Size- Controlled Synthesis of Dextran-Coated, Copper-Doped Iron Oxide Nanoparticles  

NASA Astrophysics Data System (ADS)

Development of dual modality probes enabled for magnetic resonance imaging (MRI) and positron emission tomography (PET) has been on the rise in recent years due to the potential for these probes to facilitate combining the complementary high resolution of MRI and the high sensitivity of PET. The efficient synthesis of multimodal probes that include the radiolabels for PET can be hindered due to prolonged reaction times during radioisotope incorporation, and the resulting decay of the radiolabel. Along with a time-efficient synthesis, one also needs an optimal synthesis that yields products in a desirable size range (between 20-100 nm) to increase blood retention time. In this work, we describe a novel, rapid, microwave-based synthesis of dextran-coated iron oxide nanoparticles doped with copper (DIO/Cu). Traditional methods for synthesizing dextran-coated iron oxide particles require refluxing for 2 hours and result in approximately 50 nm particles. We demonstrate that microwave synthesis can produce 50 nm nanoparticles in 5 minutes of heating. We discuss the various parameters used in the microwave synthesis protocol to vary the size distribution of DIO/Cu, and demonstrate the successful incorporation of copper into these particles with the aim of future use for rapid 64Cu incorporation.

Wong, Ray M.

150

Dynamic properties of edge dislocations decorated by interstitial dislocation loops in alpha-iron and copper.  

SciTech Connect

Clusters of self-interstitial atoms (SIAs) in the form of parallel crowdions are created directly in high-energy displacement cascades produced in metals by neutron irradiation. They are equivalent to small perfect dislocation loops and, in isolation in pure metals, undergo fast thermally-activated glide in the direction of their Burgers vector. Their strain field and ability to glide allows long-range interaction with other extended defects. Indeed, dislocations decorated by dislocation loops are commonly observed after neutron irradiation. Dislocations gliding under applied stress also encounter these mobile defects. These effects influence mechanical properties and require further investigation. This paper presents results from an atomic-scale study of copper and {alpha}-iron at either 0 K or 300 K. Loop drag and breakaway effects are investigated for an edge dislocation under applied stress interacting with a row of SIA loops below its glide plane. The maximum speed at which a loop is dragged is lower in copper than iron, and the applied stress at which this occurs is also lower. These differences in the dynamics of cluster-dislocation interaction are determined by the atomic structure of the defects and cannot be investigated by continuum treatment.

Osetskiy, Yury N [ORNL; Bacon, David J [University of Liverpool; Rong, Zhouwen [University of Liverpool; Singh, Bachu [Riso National Laboratory, Roskilde, Denmark

2004-01-01

151

Calorie restriction up-regulates iron and copper transport genes in Saccharomyces cerevisiae.  

PubMed

Calorie restriction (CR) is a non genetic intervention, known to confer longevity benefits across the various phyla from unicellular yeast to mammals. CR also invokes homeostatic responses similar to stress, however the sequence of molecular events leading to longevity is still illusive. In this study, we analysed the whole genome gene expression profile in response to CR, mutations mimicking CR, heat shock and H(2)O(2) from a gene ontology perspective. Our analysis revealed that mitochondrion is a common hub in the gene expression programme under these conditions and the electron transport chain (ETC) is a major player. Consequently the genes involved in the metal ion transport were also significantly up-regulated. We confirmed the results of the in silico analysis using quantitative real time PCR which showed up-regulation of genes involved in respiration and transport of iron and copper. The promoter activity of one of the representative genes, FET3, was also found to be higher upon calorie restriction. Altogether, our results indicate that upon calorie restriction the levels of iron and copper fall in cells, which elicits a transcriptional response up-regulating the genes involved in their uptake to maintain cellular homeostasis. PMID:21031176

Sharma, Praveen Kumar; Mittal, Nitish; Deswal, Sumit; Roy, Nilanjan

2010-10-28

152

Iron, copper, and nickel behavior in buffered, neutral aluminum chloride:1-methyl-3-ethylimidazolium chloride molten salt  

Microsoft Academic Search

Iron, copper, and nickel electrodes were examined as possible metal\\/metal(II) chloride cathodes for the room temperature sodium\\/metal chloride battery in a molten salt composed of sodium chloride (NaCl), aluminum chloride (AlClâ), and 1-methyl-3-ethylimidazolium chloride (MEIC). The iron electrode was investigated in basic, neutral-like, and acidic MEIC:AlClâ melts. The solubility and the kinetics of the reduction of Fe(II) was a function

Stephen Pye; J. Winnick; P. A. Kohl

1997-01-01

153

Calcium, Copper, Iron, Magnesium and Zinc Utilization of Humans as Affected by Consumption of Black, Decaffeinated Black and Green Teas  

Microsoft Academic Search

LEARNING OUTCOME: The black, decaffeinated black and green teas had little, if any, influence on the subjects’ utilization of calcium, copper, iron, magnesium and zinc.Controversy exists as to the nutritional effects of tea. Both beneficial and detrimental nutritional effects have been demonstrated in animal and human studies. The objectives of the study were to compare effects of black, decaffeinated black

E. A. Prystai; C. V Kies; J. A. Driskell

1997-01-01

154

Uptake of iron, zinc, manganese, and copper by seedlings of hybrid and traditional rice cultivars from different soil types  

Microsoft Academic Search

In pot experiments, uptake of zinc (Zn), copper (Cu), iron (Fe), and manganese (Mn) by hybrid rice from different soil types was compared with a traditional rice (Oryza sativa L.) cultivar. The concentration and total uptake of Fe in the shoots of hybrid rice grown in Oxisol and Ultisol were lower than those of the traditional cultivar. The concentration and

X. Yang; V. Römheld; H. Marschner

1994-01-01

155

Influence of iron and copper nanoparticle powder on the production of lignocellulose degrading enzymes in the fungus Trametes versicolor  

Microsoft Academic Search

White rot fungi are one of the key group of microorganisms that help to enrich the soil via degradation of wood. In the current communication, influence of iron and copper nanoparticles on the production of lignocellulolytic enzymes by Trametes versicolor have been investigated. The production of enzymes in the presence of the two nanoparticles was compared to that of ferrous

Vishal Shah; Petra Dobiášová; Petr Baldrian; František Nerud; Amit Kumar; Sudipta Seal

2010-01-01

156

pH-Dependent reactivity of oxidants formed by iron and copper-catalyzed decomposition of hydrogen peroxide.  

PubMed

The decomposition of hydrogen peroxide catalyzed by iron and copper leads to the generation of reactive oxidants capable of oxidizing various organic compounds. However, the specific nature of the reactive oxidants is still unclear, with evidence suggesting the production of hydroxyl radical or high-valent metal species. To identify the reactive species in the Fenton system, the oxidation of a series of different compounds (phenol, benzoic acid, methanol, Reactive Black 5 and arsenite) was studied for iron- and copper-catalyzed reactions at varying pH values. At lower pH values, more reactive oxidants appear to be formed in both iron and copper-catalyzed systems. The aromatic compounds, phenol and benzoic acid, were not oxidized under neutral or alkaline pH conditions, whereas methanol, Reactive Black 5, and arsenite were oxidized to a different degree, depending on the catalytic system. The oxidants responsible for the oxidation of compounds at neutral and alkaline pH values are likely to be high-valent metal complexes of iron and copper (i.e., ferryl and cupryl ions). PMID:23433935

Lee, Hongshin; Lee, Hye-Jin; Sedlak, David L; Lee, Changha

2013-02-20

157

Group concentration and atomic-absorption determination of iron, manganese, Zinc, Copper, Cobalt, and nickel in powdered molybdenum and tungsten  

SciTech Connect

This paper proposes a rapid, selective, and simple method for the group concentration and separation of trace concentrations (n /SUP ./ 10/sup -4/%) of iron (III), manganese (II), zinc (II), copper (II), cobalt (II), and nickel (II) from powdered molybdenum and tungsten using the polymeric chelate sorbent polystyrene-methyleneiminino-4-nitro-6-sulfophenol.

Basargin, N.N.

1986-08-01

158

Copper, iron, and zinc imbalances in severely degenerated brain regions in Alzheimer's disease: possible relation to oxidative stress  

Microsoft Academic Search

Copper (Cu), iron (Fe), and zinc (Zn) levels in five different brain regions (amygdala, hippocampus, inferior parietal lobule, superior and middle temporal gyri, and cerebellum) were determined by instrumental neutron activation analysis (INAA) in samples from Alzheimer's disease (AD) patients and age-matched control subjects. A significant decrease in Cu, and significant increases in Zn and Fe were found in AD

M. A Deibel; W. D Ehmann; W. R Markesbery

1996-01-01

159

Iron, Zinc, and Copper Concentration in Serum, Various Organs, and Hair of Dogs with Experimentally Induced Exocrine Pancreatic Insufficiency  

Microsoft Academic Search

The concentration of iron, zinc, and copper in serum, pancreas, liver, duodenum, kidneys, myocardium, brain, and hair was studied in dogs with experimentally induced exocrine pancreatic insufficiency. Exocrine pancreatic insufficiency was performed surgically in eight healthy, 8-month-old, mongrel dogs (group I). An equal number of dogs, of the same breed and age, were used as controls (group II). One month

Katerina Adamama-Moraitou; Timoleon Rallis; Achilles Papasteriadis; Nikolaos Roubies; Helen Kaldrimidou

2001-01-01

160

Concentrations of Calcium, Copper, Iron, Magnesium, and Zinc in Young Female Hair with Different Body Mass Indexes in Taiwan  

Microsoft Academic Search

An investigation of the metal concentrations of calcium, copper, iron, magnesium, and zinc in three groups of young female hair (n = 180), from women aged between 15 to 19 years, with different body mass indexes (BMI) of BMI < 18, BMI between 18 and 23, and BMI > 24 was performed using atomic absorption spectroscopy (AAS). The hair samples

Chin-Thin Wang; Wei-Tun Chang; Lin-Her Jeng; Po-En Liu; Li-Yun Liud

2005-01-01

161

Management of dietary essential metals (iron, copper, zinc, chromium and manganese) by Wistar and Zucker obese rats fed a self-selected high-energy diet  

Microsoft Academic Search

The balances and content of essential elements (iron, copper, zinc, chromium and manganese) in the body of Wistar, Zucker lean and Zucker obese rats fed a reference or cafeteria diet from day 30 to 60 after birth have been studied. Intestinal iron absorption compensated for low iron content of the cafeteria diet and the extra needs of growth and fat

José-Antonio Fernández-López; Montserrat Esteve; Immaculada Rafecas; Xavier Remesar; Marià Alemany

1994-01-01

162

ESR of copper and iron complexes with antitumor and cytotoxic properties.  

PubMed Central

The relatively few iron and copper metal complexes which have been examined in cells and tissues for their redox properties, radical generation properties, and antitumor activity are discussed for studies which utilized electron spin resonance spectroscopy (ESR). A common property of a number of metal complexes, which include bleomycin, adriamycin, and thiosemicarbazones described in this review, is that they are readily reduced by thiol compounds and oxidized by oxygen or reduced species of oxygen to produce radicals. Structural features of these reactions are identified by ESR spectroscopy in model systems and often in cells. Furthermore, ESR spectroscopy has been most useful to probe the environment of the complexes in cells and to measure the rate of reduction of their oxidized forms. As a result of these studies, it is anticipated that more attention will be given to the exploration of redox-active metal complexes as drugs.

Antholine, W E; Kalyanaraman, B; Petering, D H

1985-01-01

163

Hot gas desulfurization with sorbents containing oxides of zinc, iron, vanadium and copper  

SciTech Connect

The main objective of this research is to evaluate the desulfurization performance of novel sorbents consisting of different combinations of zinc, iron, vanadium and copper oxides; and to develop a sorbent which can reduce H{sub 2}S levels to less than 1 ppmv, which can stabilize zinc, making operations above 650{degrees}C possible, and which can produce economically recoverable amounts of elemental sulfur during regeneration. This objective will be accomplished by evaluating the sorbent performance using fixed-bed and TGA experiments supported by sorbent characterization at various reaction extents. In the seventh quarter, the screening of the promoted sorbents in the packed bed reactor was continued. The results of this work were presented at the 1992 University Coal Research Contractors, Review Conference at Pittsburgh, PA.

Akyurtlu, A.; Akyurtlu, J.F.

1992-01-01

164

Hot gas desulfurization with sorbents containing oxides of zinc, iron, vanadium and copper  

SciTech Connect

The main objective of this research is to evaluate the desulfurization performance of novel sorbents consisting of different combinations of zinc, iron, vanadium and copper oxides; and to develop a sorbent which can reduce H{sub 2}S levels to less than 1 ppmv, which can stabilize zinc, making operations above 650{degrees}C possible, and which can produce economically recoverable amounts of elemental sulfur during regeneration. This objective will be accomplished by evaluating the sorbent performance using fixed-bed and TGA experiments supported by sorbent characterization at various reaction extents. The work done in the fourth quarter can be summarized as follows: (1) Calibration of the gas chromatograph for low and high H{sub 2}S and SO{sub 2} is completed. (2) The determination of surface areas and densities of the promoted sorbents is completed. (3) Preliminary screening of the promoted sorbents in the packed bed reactor has started.

Akyurtlu, A.

1991-10-01

165

Analytical methods for copper, zinc and iron quantification in mammalian cells.  

PubMed

Highly complex analytical methods with different accuracies of measurement, reproducibilities and ease of analyses are currently being used to quantify metals in cellular media and tissue samples. In this review, the analytical methods commonly used for iron, copper and zinc quantification in mammalian cells are presented and discussed. Herein, we present a literature survey of the most commonly found concentrations of these metals in various mammalian cells in culture and tissues. The aim of this review is to help researchers in metallomic-related areas identify the method that best suits their needs for the accurate quantification of these metals in cells. This accuracy goes beyond simple knowledge of the limit of detection of each technique and needs to be evaluated through comparisons with similar previous studies. PMID:23925479

Cerchiaro, Giselle; Manieri, Tania Maria; Bertuchi, Fernanda Rodrigues

2013-09-25

166

Distribution of nickel between copper-nickel and alumina saturated iron silicate slags  

NASA Astrophysics Data System (ADS)

The solubility of nickel in slag was determined by equilibrating copper-nickel alloys with alumina-saturated iron silicate slags in an alumina crucible at 1573 K. The experiments were carried out under controlled oxygen partial pressures in the range of 10-10 to 10-8 atm by use of suitable CO-CO2 gas mixtures, and at Fe/SiO2 ratio 1.34. The results showed that nickel dissolves in slag both as Ni2+ (nickel oxide) and Ni‡ (nickel metal), and the relation obtained was: (Wt pct Ni in slag) = (ie33-01) The activity coefficient of nickel oxide (?dgNio) and distribution coefficient of nickel (ANi) is calculated to be 0.375 and 233.3, respectively. ?dgNio and ANi are found to be independent of oxygen partial pressures. The presence of alumina increases the solubility of nickel in slags.

Reddy, R. G.; Acholonu, C. C.

1984-01-01

167

Three histidine residues of amyloid-beta peptide control the redox activity of copper and iron.  

PubMed

Zinc, iron and copper are concentrated in senile plaques of Alzheimer disease. Copper and iron catalyze the Fenton-Haber-Weiss reaction, which likely contributes to oxidative stress in neuronal cells. In this study, we found that ascorbate oxidase activity and the intensity of ascorbate radicals measured using ESR spectroscopy, generated by free Cu(II), was decreased in the presence of amyloid-beta (Abeta), the major component of senile plaques. Specifically, the ascorbate oxidase activity was strongly inhibited (85% decrease) in the presence of Abeta1-16 or Abeta1-42, whereas it was only slightly inhibited in the presence of Abeta1-12 or Abeta25-35 (<20% inhibition). Ascorbate-dependent hydroxyl radical generation by free Cu(II) decreased in the presence of Abeta in the identical order of Abeta1-42, Abeta1-16 > Abeta1-12 and was abolished in the presence of 2-fold molar excess glycylhystidyllysine (GHK). Ascorbate oxidase activity and ascorbate-dependent hydroxyl radical generation by free Fe(III) were inhibited by Abeta1-42, Abeta1-16, and Abeta1-12. Although Cu(II)-Abeta shows a significant SOD-like activity, the rate constant for the reaction of superoxide with Cu(II)-Abeta was much slower than that with SOD. Overall, our results suggest that His6, His13, and His14 residues of Abeta1-42 control the redox activity of transition metals present in senile plaques. PMID:17929832

Nakamura, M; Shishido, N; Nunomura, Akihiko; Smith, Mark A; Perry, George; Hayashi, Y; Nakayama, K; Hayashi, T

2007-10-11

168

Bioremediation of copper-containing wastewater by sulfate reducing bacteria coupled with iron.  

PubMed

In order to treat copper-containing wastewater effectively using sulfate reducing bacteria (SRB), iron (Fe(0)) was added to enhance the activity of SRB. The SRB system and the SRB + Fe(0) system were operated under continuous operation. The sulfate reduction efficiency of the SRB + Fe(0) system was twice as much as that of the SRB system with the sulfate loading rate at 125  mg L(-1) h(-1). The effect of COD/SO4(2-) on sulfate reduction indicates an enhanced activity of SRB by adding Fe(0). 99% of total sulfate was deducted in both systems at pH 4.0-7.0, and temperature slightly influenced the removal of sulfate in the SRB + Fe(0) system. In the copper-containing wastewater treatment, the SRB + Fe(0) system shows a better performance since sulfate removal in this system was higher than the SRB system, and the removal ratio of Cu(2+) was held above 95% in SRB + Fe(0) system at all influent Cu(2+) concentrations. PMID:23981707

Bai, He; Kang, Yong; Quan, Hongen; Han, Yang; Sun, Jiao; Feng, Ying

2013-08-26

169

Regulation of Brain Iron and Copper Homeostasis by Brain Barrier Systems: Implication in Neurodegenerative Diseases  

PubMed Central

Iron (Fe) and copper (Cu) are essential to neuronal function; excess or deficiency of either is known to underlie the pathoetiology of several commonly known neurodegenerative disorders. This delicate balance of Fe and Cu in the central milieu is maintained by the brain barrier systems, i.e., the blood-brain barrier (BBB) between the blood and brain interstitial fluid and the blood- cerebrospinal fluid barrier (BCB) between the blood and cerebrospinal fluid (CSF). This review provides a concise description on the structural and functional characteristics of the brain barrier systems. Current understanding of Fe and Cu transport across the brain barriers is thoroughly examined, with major focuses on whether the BBB and BCB coordinate the direction of Fe and Cu fluxes between the blood and brain/CSF. In particular, the mechanism by which pertinent metal transporters in the barriers, such as the transferrin receptor (TfR), divalent metal transporter (DMT1), copper transporter (CTR1), ATP7A/B, and ferroportin (FPN), regulate metal movement across the barriers is explored. Finally, the detrimental consequences of dysfunctional metal transport by brain barriers, as a result of endogenous disorders or exogenous insults, are discussed. Understanding the regulation of Fe and Cu homeostasis in the central nervous system aids in the design of new drugs targeted on the regulatory proteins at the brain barriers for the treatment of metal’s deficiency or overload-related neurological diseases.

Zheng, Wei; Monnot, Andrew D.

2011-01-01

170

Regulation of brain iron and copper homeostasis by brain barrier systems: implication in neurodegenerative diseases.  

PubMed

Iron (Fe) and copper (Cu) are essential to neuronal function; excess or deficiency of either is known to underlie the pathoetiology of several commonly known neurodegenerative disorders. This delicate balance of Fe and Cu in the central milieu is maintained by the brain barrier systems, i.e., the blood-brain barrier (BBB) between the blood and brain interstitial fluid and the blood-cerebrospinal fluid barrier (BCB) between the blood and cerebrospinal fluid (CSF). This review provides a concise description on the structural and functional characteristics of the brain barrier systems. Current understanding of Fe and Cu transport across the brain barriers is thoroughly examined, with major focuses on whether the BBB and BCB coordinate the direction of Fe and Cu fluxes between the blood and brain/CSF. In particular, the mechanism by which pertinent metal transporters in the barriers, such as the transferrin receptor (TfR), divalent metal transporter (DMT1), copper transporter (CTR1), ATP7A/B, and ferroportin (FPN), regulate metal movement across the barriers is explored. Finally, the detrimental consequences of dysfunctional metal transport by brain barriers, as a result of endogenous disorders or exogenous insults, are discussed. Understanding the regulation of Fe and Cu homeostasis in the central nervous system aids in the design of new drugs targeted on the regulatory proteins at the brain barriers for the treatment of metal's deficiency or overload-related neurological diseases. PMID:22115751

Zheng, Wei; Monnot, Andrew D

2011-11-13

171

Study of Reaction Mechanisms for Copper-Cobalt-Iron Sulfide Concentrates in the Presence of Lime and Carbon  

NASA Astrophysics Data System (ADS)

The reaction mechanisms for the carbothermic reduction of complex mineral sulfide concentrates in the presence of lime were studied between 1073 K and 1323 K. The reaction mechanisms were studied by stopping the reduction experiments at different times and analyzing the reaction products by x-ray diffraction and scanning electron microscopy techniques. Magnetite (Fe3O4) and digenite (Cu1.8S) were the initial phases formed during reduction of CuFeS2 and Cu5FeS4 mineral particles, such that metallization of iron occurred before copper above 1173 K and at an equal stoichiometric ratio of CaO and C. The metallization of iron was found to take place via reduction of intermediate oxide phase (Fe3O4/FeO), whereas metallization of copper occurred via diffusion of S2- ions away from the mineral particles or via formation of Cu-O-S liquid phase. Metallic iron and cobalt were embedded in the copper matrix due to a preferential reduction of iron and cobalt from the Cu-Fe-S and Cu-Co-S type of mineral particles. The effects of CaO/C ratio were analyzed and the rate of reactions was increasing with an increase in the CaO/C ratio. The formation of liquid phase has been discussed. The experimental results were found to be in good agreement with the thermodynamic predictions.

Hara, Yotamu Stephen Rainford

2013-09-01

172

The Homeostasis of Iron, Copper, and Zinc in Paracoccidioides Brasiliensis, Cryptococcus Neoformans Var. Grubii, and Cryptococcus Gattii: A Comparative Analysis  

PubMed Central

Iron, copper, and zinc are essential for all living organisms. Moreover, the homeostasis of these metals is vital to microorganisms during pathogenic interactions with a host. Most pathogens have developed specific mechanisms for the uptake of micronutrients from their hosts in order to counteract the low availability of essential ions in infected tissues. We report here an analysis of genes potentially involved in iron, copper, and zinc uptake and homeostasis in the fungal pathogens Paracoccidioides brasiliensis, Cryptococcus neoformans var. grubii, and Cryptococcus gattii. Although prior studies have identified certain aspects of metal regulation in Cryptococcus species, little is known regarding the regulation of these elements in P. brasiliensis. We also present amino acid sequences analyses of deduced proteins in order to examine possible conserved domains. The genomic data reveals, for the first time, genes associated to iron, copper, and zinc assimilation and homeostasis in P. brasiliensis. Furthermore, analyses of the three fungal species identified homologs to genes associated with high-affinity uptake systems, vacuolar and mitochondrial iron storage, copper uptake and reduction, and zinc assimilation. However, homologs to genes involved in siderophore production were only found in P. brasiliensis. Interestingly, in silico analysis of the genomes of P. brasiliensis Pb01, Pb03, and Pb18 revealed significant differences in the presence and/or number of genes involved in metal homeostasis, such as in genes related to iron reduction and oxidation. The broad analyses of the genomes of P. brasiliensis, C. neoformans var. grubii, and C. gattii for genes involved in metal homeostasis provide important groundwork for numerous interesting future areas of investigation that are required in order to validate and explore the function of the identified genes and gene pathways.

Silva, Mirelle Garcia; Schrank, Augusto; Bailao, Elisa Flavia L.C.; Bailao, Alexandre Melo; Borges, Clayton Luiz; Staats, Charley Christian; Parente, Juliana Alves; Pereira, Maristela; Salem-Izacc, Silvia Maria; Mendes-Giannini, Maria Jose Soares; Oliveira, Rosely Maria Zancope; Silva, Livia Kmetzsch Rosa e; Nosanchuk, Joshua D.; Vainstein, Marilene Henning; de Almeida Soares, Celia Maria

2011-01-01

173

Barium enema (image)  

MedlinePLUS

A barium enema is performed to examine the walls of the colon. During the procedure, a well lubricated enema tube is inserted gently into the rectum. The barium, a radiopaque (shows up on X-ray) contrast ...

174

A stable-isotope study of zinc, copper, and iron absorption and retention by young women fed vitamin B6--deficient diets13  

Microsoft Academic Search

ABSTRACI' A 98-d study was conducted in young women to determine the effect of vitamin B-6--deficient diets on zinc, copper, and iron metabolism. Young women were fed vitamin B-6-.dcficicnt formula initially, followed by food diets containing four increasing amounts ofvitamin B-6. Zinc, copper, and iron absorption, retention, and status were determined at intervals throughout the study. Zinc absorption and retention

Judith R Turniund; William R Keyes; Carol A Hudson; Antoinette A Betschart; Mary J Kretsch; Howerde E Sauberlich

175

Comparison of the early stages of corrosion of copper and iron investigated by in situ TM-AFM  

NASA Astrophysics Data System (ADS)

Tapping mode atomic force microscopy (TM-AFM) was used for the investigation of the early stages of atmospheric corrosion of pure copper and pure iron. The information obtained by this method is the change of the topography of the sample surfaces with emphasis on the shape and lateral distribution of the corrosion products grown within the first 1300 min of weathering. Investigations were carried out in synthetic air at 80 and 90% relative humidity (RH) with additions of 250 ppb SO 2 and 250 ppb NO 2. On a polished copper surface the growth of corrosion products could be observed already at 80% RH and 250 ppb SO 2, whereas an iron surface had to be exposed to 90% RH with 250 ppb SO 2 and 250 ppb NO 2 to produce detectable changes on the surface.

Kleber, Ch.; Weissenrieder, J.; Schreiner, M.; Leygraf, C.

2002-06-01

176

Effects of zinc, iron and copper deficiencies on cadmium in tissues of Japanese quail. [Coturnix coturnix japonica  

SciTech Connect

Experiments with young Japanese quail were conducted to determine whether combined moderate deficiencies of zinc, iron and copper would cause greater uptake and tissue retention of cadmium than the single deficiencies. Birds were fed the experimental diets containing 62 ppb cadmium from hatching to 16 days of age. On day 9 each bird received a dose of /sup 109/CdCl/sub 2/ in its diet. On day 10, the duodenal and jejunal-ileal tissues contained large amounts of cadmium, and there were many significant effects of treatment on cadmium-109 retention in the livers and kidneys. At day 16, zinc deficiency caused increased cadmium in the liver, whereas iron and copper deficiencies each caused increased cadmium in the kidneys. Combined deficiencies had little or no greater effect than single deficiencies and in some cases the combined effect was less than that of a single deficiency. 13 references, 11 tables.

Fox, M.R.S.; Tao, S.H.; Stone, C.L.; Fry, B.E. Jr.

1984-03-01

177

An intrusion-related origin for Cu–Au mineralization in iron oxide–copper–gold (IOCG) provinces  

Microsoft Academic Search

Major Cu–Au deposits of iron oxide–copper–gold (IOCG) style are temporally associated with oxidized, potassic granitoids similar to those linked to major porphyry Cu–Au deposits. Stable and radiogenic isotope evidence indicates fluids and ore components were likely sourced from the intrusions. IOCG deposits form over a range of crustal levels because CO2-rich fluids separate from the magmas at higher pressures than

Peter J. Pollard

2006-01-01

178

Assimilation of zinc, cadmium, lead, copper, and iron by the spider Dysdera crocata, a predator of woodlice  

SciTech Connect

In this paper, an experiment is described on the assimilation of zinc, cadmium, lead, copper and iron by Dysdera crocata collected from a site in central Bristol. The spiders were fed on woodlice from their own site, and on woodlice from a site contaminated by a smelting works which contained much higher levels of zinc, cadmium and lead than the spiders would have been used to in their normal diet.

Hopkin, S.P.; Martin, M.H.

1985-02-01

179

The effect of malathion, diazinon, and various concentrations of zinc, copper, nickel, lead, iron, and mercury on fish  

Microsoft Academic Search

Acute and chronic toxicity tests for malathion, diazinon, copper (Cu), mercury (Hg), lead (Pb), zinc (Zn), nickel (Ni), and\\u000a iron (Fe) were conducted. Mortalities ofBarilius vagra andCyprinus carpio (common carp) were variable but LC50-96 hr were similar for pesticides. AdultB. vagra seem to be more sensitive to malathion than juvenile carp. Both juvenile carp and adultB. vagra were extremely sensitive

M. K. Alam; O. E. Maughan

1992-01-01

180

Multiple Menkes copper ATPase (Atp7a) transcript and protein variants are induced by iron deficiency in rat duodenal enterocytes.  

PubMed

The Menkes copper ATPase (Atp7a) pumps copper into the trans-Golgi for cuproenzyme synthesis, and translocates to the basolateral membrane of enterocytes for copper export. Recent studies demonstrated that three 5' end splice variants of the Atp7a transcript exist in rat duodenum, all of which are strongly induced during iron deprivation. To explore a possible role for Atp7a (and copper) in intestinal iron absorption, the current studies were undertaken to test the hypothesis that multiple Atp7a transcript and protein variants exist in intestinal epithelial cells. Northern blot analyses using probes generated from the full-length Atp7a cDNA revealed several specific hybridization bands, all of which were more intense in RNA samples extracted from duodenal enterocytes isolated from iron-deficient rats. A PCR-based approach, using forward primers specific for the alternative 5' end splice variants and a reverse primer in exon 23, demonstrated that 3 full-length transcripts exist in rat IEC-6 cells. To identify possible Atp7a protein variants, three distinct polyclonal antisera were utilized. The specificity of the antisera was first established by western blotting and immunoprecipitation studies using samples derived from isolated rat enterocytes and Atp7a knockdown IEC-6 cells. Several specific immunoreactive bands were documented, and a unique Atp7a protein distribution in cytosolic vesicle-like structures was noted. In conclusion, multiple Atp7a transcript and protein variants exist in rodent intestinal epithelial cells and are induced by dietary iron deprivation. Further studies will be designed to determine the subcellular distribution of Atp7a protein variants and possible unique functions of each. PMID:22579041

Lu, Yan; Kim, Changae; Collins, James F

2012-05-10

181

Rapid quantification of iron, copper and zinc in food premixes using energy dispersive X-ray fluorescence  

Microsoft Academic Search

A simple and rapid method for the determination of iron, copper and zinc in food premixes (used during human food processing) by energy dispersive X-ray fluorescence (XRF) has been established and validated using 25 samples. Reference values were obtained by inductively coupled plasma-optical emission spectroscopy after microwave acidic digestions. Studied samples presenting wide ranges of concentrations: Fe=500–35000mg\\/kg, Cu=50–4000mg\\/kg and Zn=700–32000mg\\/kg

Loïc Perring; Daniel Andrey; Daniel Hammer

2005-01-01

182

Specific Inhibition of NEIL-initiated Repair of Oxidized Base Damage in Human Genome by Copper and Iron  

PubMed Central

Dyshomeostasis of transition metals iron and copper as well as accumulation of oxidative DNA damage have been implicated in multitude of human neurodegenerative diseases, including Alzheimer disease and Parkinson disease. These metals oxidize DNA bases by generating reactive oxygen species. Most oxidized bases in mammalian genomes are repaired via the base excision repair pathway, initiated with one of four major DNA glycosylases: NTH1 or OGG1 (of the Nth family) or NEIL1 or NEIL2 (of the Nei family). Here we show that Fe(II/III) and Cu(II) at physiological levels bind to NEIL1 and NEIL2 to alter their secondary structure and strongly inhibit repair of mutagenic 5-hydroxyuracil, a common cytosine oxidation product, both in vitro and in neuroblastoma (SH-SY5Y) cell extract by affecting the base excision and AP lyase activities of NEILs. The specificity of iron/copper inhibition of NEILs is indicated by a lack of similar inhibition of OGG1, which also indicated that the inhibition is due to metal binding to the enzymes and not DNA. Fluorescence and surface plasmon resonance studies show submicromolar binding of copper/iron to NEILs but not OGG1. Furthermore, Fe(II) inhibits the interaction of NEIL1 with downstream base excision repair proteins DNA polymerase ? and flap endonuclease-1 by 4–6-fold. These results indicate that iron/copper overload in the neurodegenerative diseases could act as a double-edged sword by both increasing oxidative genome damage and preventing their repair. Interestingly, specific chelators, including the natural chemopreventive compound curcumin, reverse the inhibition of NEILs both in vitro and in cells, suggesting their therapeutic potential.

Hegde, Muralidhar L.; Hegde, Pavana M.; Holthauzen, Luis M. F.; Hazra, Tapas K.; Rao, K. S. Jagannatha; Mitra, Sankar

2010-01-01

183

MULTIPLE MENKES COPPER ATPASE (ATP7A) TRANSCRIPT AND PROTEIN VARIANTS ARE INDUCED BY IRON DEFICIENCY IN RAT DOUDENAL ENTEROCYTES  

PubMed Central

The Menkes copper ATPase (Atp7a) pumps copper into the trans-Golgi for cuproenzyme synthesis, and translocates to the basolateral membrane of enterocytes for copper export. Recent studies demonstrated that three 5’ end splice variants of the Atp7a transcript exist in rat duodenum, all of which are strongly induced during iron deprivation. To explore a possible role for Atp7a (and copper) in intestinal iron absorption, the current studies were undertaken to test the hypothesis that multiple Atp7a transcript and protein variants exist in intestinal epithelial cells. Northern blot analyses using probes generated from the full-length Atp7a cDNA revealed several specific hybridization bands, all of which were more intense in RNA samples extracted from duodenal enterocytes isolated from iron-deficient rats. A PCR-based approach, using forward primers specific for the alternative 5’ end splice variants and a reverse primer in exon 23, demonstrated that 3 full-length transcripts exist in rat IEC-6 cells. To identify possible Atp7a protein variants, three distinct polyclonal antisera were utilized. The specificity of the antisera was first established by western blotting and immunoprecipitation studies using samples derived from isolated rat enterocytes and Atp7a knockdown IEC-6 cells. Several specific immunoreactive bands were documented, and a unique Atp7a protein distribution in cytosolic vesicle-like structures was noted. In conclusion, multiple Atp7a transcript and protein variants exist in rodent intestinal epithelial cells and are induced by dietary iron deprivation. Further studies will be designed to determine the subcellular distribution of Atp7a protein variants and possible unique functions of each.

Lu, Yan; Kim, Changae; Collins, James F.

2013-01-01

184

Synovial fluid and plasma selenium, copper, zinc, and iron concentrations in patients with rheumatoid arthritis and osteoarthritis  

Microsoft Academic Search

In recent years, a great number of studies have investigated the possible role of trace elements in the etiology and pathogenesis\\u000a of rheumatoid arthritis (RA) and osteoartritis (OA). We studied synovial fluid and plasma concentrations of selenium (Se),\\u000a zinc (Zn), copper (Cu), and iron (Fe) in patients with RA and OA and compared them with sex- and age-matched healthy subjects.

M. Yazar; S. Sarban; A. Kocyigit; U. E. Isikan

2005-01-01

185

Tribological behaviour and statistical experimental design of sintered iron–copper based composites  

NASA Astrophysics Data System (ADS)

The sintered iron–copper based composites for automotive brake pads have a complex composite composition and should have good physical, mechanical and tribological characteristics. In this paper, we obtained frictional composites by Powder Metallurgy (P/M) technique and we have characterized them by microstructural and tribological point of view. The morphology of raw powders was determined by SEM and the surfaces of obtained sintered friction materials were analyzed by ESEM, EDS elemental and compo-images analyses. One lot of samples were tested on a "pin-on-disc" type wear machine under dry sliding conditions, at applied load between 3.5 and 11.5 × 10?1 MPa and 12.5 and 16.9 m/s relative speed in braking point at constant temperature. The other lot of samples were tested on an inertial test stand according to a methodology simulating the real conditions of dry friction, at a contact pressure of 2.5–3 MPa, at 300–1200 rpm. The most important characteristics required for sintered friction materials are high and stable friction coefficient during breaking and also, for high durability in service, must have: low wear, high corrosion resistance, high thermal conductivity, mechanical resistance and thermal stability at elevated temperature. Because of the tribological characteristics importance (wear rate and friction coefficient) of sintered iron–copper based composites, we predicted the tribological behaviour through statistical analysis. For the first lot of samples, the response variables Yi (represented by the wear rate and friction coefficient) have been correlated with x1 and x2 (the code value of applied load and relative speed in braking points, respectively) using a linear factorial design approach. We obtained brake friction materials with improved wear resistance characteristics and high and stable friction coefficients. It has been shown, through experimental data and obtained linear regression equations, that the sintered composites wear rate increases with increasing applied load and relative speed, but in the same conditions, the frictional coefficients slowly decrease.

Popescu, Ileana Nicoleta; Ghi??, Constantin; Bratu, Vasile; Palacios Navarro, Guillermo

2013-11-01

186

Iron, copper, and nickel behavior in buffered, neutral aluminum chloride:1-methyl-3-ethylimidazolium chloride molten salt  

SciTech Connect

Iron, copper, and nickel electrodes were examined as possible metal/metal(II) chloride cathodes for the room temperature sodium/metal chloride battery in a molten salt composed of sodium chloride (NaCl), aluminum chloride (AlCl{sub 3}), and 1-methyl-3-ethylimidazolium chloride (MEIC). The iron electrode was investigated in basic, neutral-like, and acidic MEIC:AlCl{sub 3} melts. The solubility and the kinetics of the reduction of Fe(II) was a function of acidity. In the basic melt, the FeCl{sub 2} was soluble; however, its reduction was not observed due to slow kinetics. In the neutral-like and acidic melts, the quasi-reversible reduction of Fe(II) to Fe(0) was observed. The redox potential of copper was approximately 1 V more positive of iron; however, the oxidized copper was soluble in the neutral-like melt, making it unacceptable without a separator. The oxidized and reduced forms of nickel were insoluble and the redox potential was 2.5 V positive of Na/Na{sup +}. The nickel electrode supported a charge density of 3.5 mC/cm{sup 2} at room temperature, suggesting that a high-surface-area electrode would be needed in a practical device.

Pye, S.; Winnick, J.; Kohl, P.A. [Georgia Inst. of Tech., Atlanta, GA (United States). School of Chemical Engineering

1997-06-01

187

Copper, iron, manganese, and zinc content of hair from two populations of rhesus monkeys.  

PubMed

The concentrations of the elements copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) in hair of caged (in Maryland) and free-ranging (in Puerto Rico) rhesus monkey populations were determined. Significant chronological age-related decreases were evident for the trace elements Mn and Zn in both populations (P < or = 0.01) and for Cu and Fe in free-ranging monkeys (P < or = 0.005). The only overall gender difference was higher hair Mn concentration in free-ranging males than in females (P < 0.03). There were no significant differences in hair Cu, Fe, or Mn related to pregnancy status. Hair Zn was lower in samples from pregnant than from nonpregnant monkeys from the caged monkeys (P < or = 0.05), but did not differ in the free-ranging monkeys. Comparison of the two populations revealed that hair Zn levels were significantly higher in caged vs free-ranging animals (P < 0.001). We attribute this higher hair Zn in the caged monkeys to contact and ingestion of Zn from their galvanized enclosures. Hair iron levels were significantly higher (P < 0.001) in free-ranging monkeys, possibly as a result of Fe-rich soil ingestion from their environment. These data support continued investigation of the use of hair as an indicator of the exposure of large groups or populations to potentially high levels of specific minerals, and the use of nonhuman primates as models for the study of trace element deficiency and/or toxicity in humans. PMID:8862746

Marriott, B M; Smith, J C; Jacobs, R M; Jones, A O; Altman, J D

1996-01-01

188

Mixed messages in iron oxide–copper–gold systems of the Cloncurry district, Australia: insights from PIXE analysis of halogens and copper in fluid inclusions  

Microsoft Academic Search

Proterozoic rocks of the Cloncurry district in NW Queensland, Australia, are host to giant (tens to hundreds of square kilometers)\\u000a hydrothermal systems that include (1) barren regional sodic–calcic alteration, (2) granite-hosted hydrothermal complexes with\\u000a magmatic–hydrothermal transition features, and (3) iron oxide–copper–gold (IOCG) deposits. Fluid inclusion microthermometry\\u000a and proton-induced X-ray emission (PIXE) show that IOCG deposits and the granite-hosted hydrothermal complexes

Timothy Baker; Roger Mustard; Bin Fu; Patrick J. Williams; Guoyi Dong; Louise Fisher; Geordie Mark; Chris G. Ryan

2008-01-01

189

Influence of Copper Addition and Temperature on the Kinetics of Austempering in Ductile Iron  

NASA Astrophysics Data System (ADS)

Austempered ductile iron (ADI) is a material that exhibits excellent mechanical properties because of its special microstructure, combining ferrite and austenite supersaturated with carbon. Two ADI alloys, Fe-3.5 pct C-2.5 pct Si and Fe-3.6 pct C-2.7 pct Si-0.7 pct Cu, austempered for various times at 623 K (350 °C) and 673 K (400 °C) followed by water quenching, were investigated. The first ferrite needles nucleate mainly at the graphite/austenite interface. The austenite and ferrite weight fractions increase with the austempering time until stabilization is reached. The increase in the lattice parameter of the austenite during austempering corresponds to an increase of carbon content in the austenite. The increase in the ferrite weight fraction is associated with a decrease in microhardness. As the austempering temperature increases, the ferrite weight fraction decreases, the high carbon austenite weight fraction increases, but the carbon content in the latter decreases. Copper addition increases the high carbon austenite weight fraction. The results are discussed based on the phases composing the Fe-2Si-C system.

Amran, Yogev; Katsman, Alexander; Schaaf, Peter; Bamberger, Menachem

2010-10-01

190

Microstructure and Mechanical Properties of As-Cast Ductile Irons Alloyed with Manganese and Copper  

NASA Astrophysics Data System (ADS)

The present investigation was carried out to study the effect of manganese and copper addition, singly as well as in combination, on the microstructure, micro-segregation, and mechanical properties of ductile irons. Alloy A (3.18C, 2.64Si, 0.45Mn), alloy B (3.35C, 2.51Si, 0.82Mn), alloy C (3.16C, 2.80Si, 1.08Mn, 0.56Cu), and alloy D (3.18C, 3.00Si, 1.04Mn, 1.13Cu) were melted and cast in the form of Y-block test pieces. The cast microstructures varied from ferrito-pearlitic in alloys A, B, and C to pearlitic in alloy D. However, on XRD analysis and SEM examination, the presence of martensite patches was also detected. There was a marginal decrease in nodule count in alloy B. In alloys C and D, nodule counts were higher, but the proportion of ferrite decreased drastically. Alloy D was found to be the strongest (UTS ? 800 MPa, El = 5%) with alloys A and C coming next in strength; while alloy B was weakest of the four. The presence of martensite patches in association with pearlite appears to be responsible for low toughness of these alloys. Microprobe analysis shows some silicon segregation near the graphite nodules and practically little segregation of manganese. Elemental mapping by FE-SEM does not indicate any manganese segregation.

Dasgupta, Ranjan Kumar; Mondal, Dipak Kumar; Chakrabarti, Ajit Kumar; Ganguli, Ashis Chandra

2012-08-01

191

Three-dimensional electric field predictions of an iron-copper galvanic couple  

NASA Astrophysics Data System (ADS)

Based on completed experimental electric field scans and the corresponding finite element field predictions, it appears that the finite element numerical technique presents a strong analytical tool in calculating the nearfield electric intensity distributions about active microcells. These calculations were analytically achieved with the new double membrane finite element configuration representing nonlinear polarization and with a local tangent slope (impedance) definition dependent on the local potential difference. The experimental determination of the multidimensional current density structure was realized with a newly developed scanning vibrating electrode technique (SVET). The finite element model developed in this paper uses a priori measured uncoupled polarization curves for pure iron and pure copper. The current densities and the electric field intensities were calculated in the X, Y, and Z directions within specific regions of the electrolyte and on its boundaries. Results appear to indicate that first-order anodic mass loss can be predicated using (1) numerically predicted current density distributions on the anodic surface and (2) Faraday's law. The electric field correlation established in this work for the three-dimensional current density components provides the confidence to proceed in the evaluation of time-dependent effects of electric fields and multipolarized surfaces associated with pitting and crevice corrosion.

Kasper, Rolf G.

1987-02-01

192

Anticonvulsant-induced changes in tissue manganese, zinc, copper, and iron concentrations in Wistar rats.  

PubMed

Human epileptics have been reported to have low blood manganese (Mn) concentrations in comparison to nonepileptics, an observation that is important because Mn deficiency can increase seizure susceptibility in experimental animals. Factors that have been suggested to contribute to the low blood Mn levels in epileptics include anticonvulsant use, seizure-induced tissue redistribution of Mn, and genetics; in the present study, the first of these possibilities was tested. Wistar rats were fed semipurified diets containing diphenylhydantoin ([DPH] 3 g/kg diet), phenobarbital ([PB] 2 g/kg diet), or primidone ([PRIM] 3 g/kg diet) for 7 weeks, at which time they were killed and tissues collected and analyzed for Mn, zinc (Zn), copper (Cu), and iron (Fe) concentrations. In comparison to pair-fed rats, DPH- and PRIM-fed rats had significantly elevated liver Mn concentrations, while Mn concentrations in blood, brain, heart, and kidney were unaffected by anticonvulsant exposure. Changes in the concentrations of Zn, Cu, and Fe in specific tissues were also found. Overall, these findings suggest that the anticonvulsants tested do not lead to significant derangements in the metabolism of Mn. PMID:8345801

Critchfield, J W; Carl, F G; Keen, C L

1993-07-01

193

Barium appendicitis 1 month after a barium meal.  

PubMed

Abstract Because barium sulfate (BaSO(4)) is not harmful to the mucosa, it is widely used for gastrointestinal imaging. Barium appendicitis is a very rare complication of barium meals and barium enema. We report a case of acute appendicitis associated with retained appendiceal barium. A 47-year-old man presented with right lower abdominal pain after upper gastrointestinal imaging was performed using barium 1 month earlier. The abdominal plain roentgenogram showed an area of retained barium in the right lower quadrant. Multiplanar reconstruction of computed tomography scans showed barium retention in the appendix. Emergency appendectomy was performed. A cross section of the specimen revealed the barium mass. Barium-associated appendicitis is a very rare clinical entity but we should be cautious of this uncommon disease when we encounter barium deposits in the appendix after barium examination. This report is significant because barium was identified both macroscopically and microscopically. PMID:23294068

Urade, Masaaki; Shinbo, Toshihumi

194

Barium Appendicitis 1 Month After a Barium Meal  

PubMed Central

Because barium sulfate (BaSO4) is not harmful to the mucosa, it is widely used for gastrointestinal imaging. Barium appendicitis is a very rare complication of barium meals and barium enema. We report a case of acute appendicitis associated with retained appendiceal barium. A 47-year-old man presented with right lower abdominal pain after upper gastrointestinal imaging was performed using barium 1 month earlier. The abdominal plain roentgenogram showed an area of retained barium in the right lower quadrant. Multiplanar reconstruction of computed tomography scans showed barium retention in the appendix. Emergency appendectomy was performed. A cross section of the specimen revealed the barium mass. Barium-associated appendicitis is a very rare clinical entity but we should be cautious of this uncommon disease when we encounter barium deposits in the appendix after barium examination. This report is significant because barium was identified both macroscopically and microscopically.

Urade, Masaaki; Shinbo, Toshihumi

2012-01-01

195

Effect of the metals iron, copper and silver on fluorobenzene biodegradation by Labrys portucalensis.  

PubMed

Organic and metallic pollutants are ubiquitous in the environment. Many metals are reported to be toxic to microorganisms and to inhibit biodegradation. The effect of the metals iron, copper and silver on the metabolism of Labrys portucalensis F11 and on fluorobenzene (FB) biodegradation was examined. The results indicate that the addition of 1 mM of Fe(2+) to the culture medium has a positive effect on bacterial growth and has no impact in the biodegradation of 1 and 2 mM of FB. The presence of 1 mM of Cu(2+) was found to strongly inhibit the growth of F11 cultures and to reduce the biodegradation of 1 and 2 mM of FB to ca. 50 %, with 80 % of stoichiometrically expected fluoride released. In the experiments with resting cells, the FB degraded (from 2 mM supplied) was reduced ca. 20 % whereas the fluoride released was reduced to 45 % of that stoichiometrically expected. Ag(+) was the most potent inhibitor of FB degradation. In experiments with growing cells, the addition of 1 mM of Ag(+) to the culture medium containing 1 and 2 mM of FB resulted in no fluoride release, whereas FB degradation was only one third of that observed in control cultures. In the experiments with resting cells, the addition of Ag(+) resulted in 25 % reduction in substrate degradation and fluoride release was only 20 % of that stoichiometrically expected. The accumulation of catechol and 4-fluorocatechol in cultures supplemented with Cu(2+) or Ag(+) suggest inhibition of the key enzyme of FB metabolism-catechol 1,2-dioxygenase. PMID:22842857

Moreira, Irina S; Amorim, Catarina L; Carvalho, Maria F; Ferreira, António C; Afonso, Carlos M; Castro, Paula M L

2012-07-29

196

The acute toxicity of iron and copper: biomolecule oxidation and oxidative damage in rat liver.  

PubMed

The transition metals iron (Fe) and copper (Cu) are needed at low levels for normal health and at higher levels they become toxic for humans and animals. The acute liver toxicity of Fe and Cu was studied in Sprague Dawley male rats (200 g) that received ip 0-60 mg/kg FeCl(2) or 0-30 mg/kg CuSO(4). Dose and time-responses were determined for spontaneous in situ liver chemiluminescence, phospholipid lipoperoxidation, protein oxidation and lipid soluble antioxidants. The doses linearly defined the tissue content of both metals. Liver chemiluminescence increased 4 times and 2 times after Fe and Cu overloads, with half maximal responses at contents (C(50%)) of 110 ?gFe/g and 42 ?gCu/g liver, and with half maximal time responses (t(1/2)) of 4h for both metals. Phospholipid peroxidation increased 4 and 1.8 times with C(50%) of 118 ?g Fe/g and 45 ?g Cu/g and with t(1/2) of 7h and 8h. Protein oxidation increased 1.6 times for Fe with C(50%) at 113 ?g Fe/g and 1.2 times for Cu with 50 ?g Cu/g and t(1/2) of 4h and 5h respectively. The accumulation of Fe and Cu in liver enhanced the rate of free radical reactions and produced oxidative damage. A similar free radical-mediated process, through the formation HO(•) and RO(•) by a Fenton-like homolytic scission of H(2)O(2) and ROOH, seems to operate as the chemical mechanism for the liver toxicity of both metals. PMID:23010331

Boveris, Alberto; Musacco-Sebio, Rosario; Ferrarotti, Nidia; Saporito-Magriñá, Christian; Torti, Horacio; Massot, Francisco; Repetto, Marisa G

2012-07-11

197

Iron and copper accumulation in the brain of coxsackievirus-infected mice exposed to cadmium  

SciTech Connect

Cadmium (Cd) is a potentially toxic metal widely distributed in the environment and known to cause adverse health effects in humans. During coxsackievirus infection, the concentrations of essential and nonessential trace elements (e.g., iron (Fe), copper (Cu), and Cd) change in different target organs of the infection. Fe and Cu are recognized cofactors in host defence reactions, and Fe is known to be associated with certain pathological conditions of the brain. However, whether nonessential trace elements could influence the balance of essential trace elements in the brain is unknown. In this study the brain Fe, Cu, and Cd contents were measured through inductively coupled plasma mass spectrometry and their distributions determined by nuclear microscopy in the early phase (day 3) of coxsackievirus B3 (CB3) infection in nonexposed and in Cd-exposed female Balb/c mice. In CB3 infection the brain is a well-known target that has not been studied with regard to trace element balance. The brain concentration of Cu compared with that of noninfected control mice was increased by 9% (P<0.05) in infected mice not exposed to Cd and by 10% (not significant) in infected Cd-exposed mice. A similar response was seen for Fe, which in infected Cd-exposed mice, compared to noninfected control mice, tended to increase by 16%. Cu showed an even tissue distribution, whereas Fe was distributed in focal deposits. Changes in Cd concentration in the brain of infected mice were less consistent but evenly distributed. Further studies are needed to define whether the accumulation and distribution of trace elements in the brain have an impact on brain function.

Ilbaeck, N.-G. [Section of Infectious Diseases, Department of Medical Sciences, Uppsala University Hospital, S-751 85 Uppsala (Sweden) and Toxicology Division, National Food Administration, Uppsala (Sweden)]. E-mail: nils-gunnar.ilback@slv.se; Lindh, U. [Research in Metal Biology, Rudbeck Laboratory, Uppsala University, Uppsala (Sweden); Minqin, R. [Centre for Ion Beam Applications, Department of Physics, National University of Singapore (Singapore); Friman, G. [Section of Infectious Diseases, Department of Medical Sciences, Uppsala University Hospital, S-751 85 Uppsala (Sweden); Watt, F. [Centre for Ion Beam Applications, Department of Physics, National University of Singapore (Singapore)

2006-11-15

198

Influence of copper, iron, zinc and fe (3) (+) haemoglobin levels on the etiopathogenesis of chronic calcific pancreatitis--a study in patients with pancreatitis.  

PubMed

Chronic pancreatitis is a serious condition associated with severe abdominal pain, and a significant percentage of patients progresses to irreversible calcification in pancreas. The present study evaluates the degree to which the levels of trace elements, copper, iron, selenium, zinc and haemoglobin-Fe(3+), in blood, serum and pancreas have any role to play in the calcification process associated with fibrosis in pancreas. Twenty-seven calcific (CCP) and 23 non-calcific chronic pancreatitis (CP) patients and equal number of age- and sex-matched normal volunteers (50) were enrolled in the study. Surgically removed pancreatic tissue and blood samples were analysed for copper, iron, selenium, zinc, protein, collagen and lipid peroxidation products in terms of malondialdehyde, protein carbonyls, glutathione, methemoglobin, methemoglobin reductase and ceruloplasmin activity levels. We could find that the pancreatic tissue levels of copper, iron, protein and collagen contents were significantly elevated in CCP patients when compared to CP patients. Serum levels of copper, free ionic copper and iron were also elevated in CCP patients. The serum and the pancreatic tissue level of zinc and selenium showed a significant decrease in CCP patients. The level of methemoglobin was elevated more significantly with the concomitant decline in the activity of methemoglobin reductase. There was a positive correlation between the pancreatic level of copper and iron with the collagen and protein levels. The results of the present study revealed that the levels of copper and iron, the pro-oxidants and zinc and selenium may influence calcification process in CCP patients. Hypoxia-related tissue injury due to the formation of oxidised haemoglobin may also contribute to the pathogenesis of calcification in pancreas. PMID:20809271

Arumugam, Geetha; Padmanaban, Monika; Krishnan, Dhanya; Panneerselvam, Saranya; Rajagopal, Surendran

2010-09-01

199

Observed transitions in n = 2 ground configurations of copper, nickel, iron, chromium and germanium in tokamak discharges  

SciTech Connect

A number of spectrum lines of highly ionized copper, nickel, iron, chromium, and germanium have been observed and the corresponding transitions identified. The element under study is introduced into the discharge of the PLT Tokamak by means of rapid ablation by a laser pulse. The ionization state is generally distinguishable from the time behavior of the emitted light. New identifications of transitions are based on predicted wavelengths (from isoelectronic extrapolation and other data) and on approximate expected intensities. All the transitions pertain to the ground configurations of the respective ions, which are the only states strongly populated at tokamak plasma conditions. These lines are expected to be useful for spectroscopic plasma diagnostics in the 1-3 keV temperature range, and they provide direct measurement of intersystem energy separations from chromium through copper in the oxygen, nitrogen, and carbon isoelectronic sequences.

Hinnov, E.; Suckewer, S.; Cohen, S.; Sato, K.

1981-11-01

200

Molecular-level investigation into copper complexes on vermiculite: Effect of reduction of structural iron on copper complexation  

Microsoft Academic Search

In this paper we present results that describe the speciation of Cu sorbed to the clay mineral vermiculite, with special attention to the effects of reduction on Cu sorption complexes. Sorption complexes were studied using powdered extended X-ray absorption fine structure (EXAFS) spectroscopy, polarized EXAFS spectroscopy, and X-ray diffraction (XRD). Ionic strength (I), background ion, and clay reduction (structural iron)

Luca J. Furnare; Arturas Vailionis; Daniel G. Strawn

2005-01-01

201

Zinc, iron, manganese, and magnesium accumulation in crayfish populations near copper-nickel smelters at Sudbury, Ontario, Canada  

SciTech Connect

The Sudbury basin has been subjected to extreme ecological disturbances from logging, mining and smelting activities. Elevated concentrations of copper, cadmium, and nickel have been reported in crayfish populations close to the Sudbury smelting works. The present study compares concentrations of zinc (Zn), iron (Fe), manganese (Mn) and magnesium (Mg) in freshwater crayfish at selected distances of the habitat from the emission source. These metals were selected since they are known to be emitted in moderately high quantities into the Sudbury environment as byproduct of the smelting process. Various tissue concentrations in crayfish were also examined to determined specific tissue sites for these accumulations.

Bagatto, G.; Alikhan, M.A.

1987-06-01

202

Attenuation in iron of neutrons produced by 120 GeV/c positive hadrons on a thick copper target  

NASA Astrophysics Data System (ADS)

A deep penetration experiment in a thick iron shield was carried out at CERN, at the CERN-EU high-energy Field (CERF) facility. A 120 GeV/c positive hadron beam impinged on a 50 cm thick copper target located inside an irradiation cave covered by an iron shield, the thickness of which could be varied from 40 to 240 cm. Measurements of neutron fluence and ambient dose equivalent were performed with a Bonner Sphere Spectrometer and an extended-range rem counter and the results compared with Monte Carlo simulations carried out with the FLUKA code. A comparison with literature data shows an acceptable agreement. A discussion is also given on the contribution of the neutron background and of its influence on a deep penetration experiment.

Agosteo, Stefano; Pozzi, Fabio; Silari, Marco; Ulrici, Luisa

2013-10-01

203

Dietary Copper, Manganese and Iron Affect the Formation of Aberrant Crypts in Colon of Rats Administered 3,2*Dimethyl4Aminobiphenyl1,2  

Microsoft Academic Search

Aberrant crypt foci (ACF) are preneoplastic lesions for colon cancer. Altered amounts of copper-zinc (CuZnSOD) and manganese (MnSOD) superoxide dismutases have been implicated in multistage carcinogesis of both rodents and humans. Dietary factors are potential modulators of both CuZnSOD and MnSOD activity. The purpose of this study was to investigate the interactive effects of dietary copper, manganese, and iron on

Cindy D. Davis; Yi Feng

204

Prevention of iron- and copper-mediated DNA damage by catecholamine and amino acid neurotransmitters, L-DOPA, and curcumin: metal binding as a general antioxidant mechanism.  

PubMed

Concentrations of labile iron and copper are elevated in patients with neurological disorders, causing interest in metal-neurotransmitter interactions. Catecholamine (dopamine, epinephrine, and norepinephrine) and amino acid (glycine, glutamate, and 4-aminobutyrate) neurotransmitters are antioxidants also known to bind metal ions. To investigate the role of metal binding as an antioxidant mechanism for these neurotransmitters, L-dihydroxyphenylalanine (L-DOPA), and curcumin, their abilities to prevent iron- and copper-mediated DNA damage were quantified, cyclic voltammetry was used to determine the relationship between their redox potentials and DNA damage prevention, and UV-vis studies were conducted to determine iron and copper binding as well as iron oxidation rates. In contrast to amino acid neurotransmitters, catecholamine neurotransmitters, L-DOPA, and curcumin prevent significant iron-mediated DNA damage (IC(50) values of 3.2 to 18 ?M) and are electrochemically active. However, glycine and glutamate are more effective at preventing copper-mediated DNA damage (IC(50) values of 35 and 12.9 ?M, respectively) than L-DOPA, the only catecholamine to prevent this damage (IC(50) = 73 ?M). This metal-mediated DNA damage prevention is directly related to the metal-binding behaviour of these compounds. When bound to iron or copper, the catecholamines, amino acids, and curcumin significantly shift iron oxidation potentials and stabilize Fe(3+) over Fe(2+) and Cu(2+) over Cu(+), a factor that may prevent metal redox cycling in vivo. These results highlight the disparate antioxidant activities of neurotransmitters, drugs, and supplements and highlight the importance of considering metal binding when identifying antioxidants to treat and prevent neurodegenerative disorders. PMID:22450660

García, Carla R; Angelé-Martínez, Carlos; Wilkes, Jenna A; Wang, Hsiao C; Battin, Erin E; Brumaghim, Julia L

2012-03-26

205

Friedreich's ataxia causes redistribution of iron, copper, and zinc in the dentate nucleus.  

PubMed

Friedreich's ataxia (FRDA) causes selective atrophy of the large neurons of the dentate nucleus (DN). High iron (Fe) concentration and failure to clear the metal from the affected brain tissue are potential risk factors in the progression of the lesion. The DN also contains relatively high amounts of copper (Cu) and zinc (Zn), but the importance of these metals in FRDA has not been established. This report describes nondestructive quantitative X-ray fluorescence (XRF) and "mapping" of Fe, Cu, and Zn in polyethylene glycol-dimethylsulfoxide (PEG/DMSO)-embedded DN of 10 FRDA patients and 13 controls. Fe fluorescence arose predominantly from the hilar white matter, whereas Cu and Zn were present at peak levels in DN gray matter. Despite collapse of the DN in FRDA, the location of the peak Fe signal did not change. In contrast, the Cu and Zn regions broadened and overlapped extensively with the Fe-rich region. Maximal metal concentrations did not differ from normal (in micrograms per milliliter of solid PEG/DMSO as means ± S.D.): Fe normal, 364 ± 117, FRDA, 344 ± 159; Cu normal, 33 ± 13, FRDA, 33 ± 18; and Zn normal, 32 ± 16, FRDA, 33 ± 19. Tissues were recovered from PEG/DMSO and transferred into paraffin for matching with immunohistochemistry of neuron-specific enolase (NSE), glutamic acid decarboxylase (GAD), and ferritin. NSE and GAD reaction products confirmed neuronal atrophy and grumose degeneration that coincided with abnormally diffuse Cu and Zn zones. Ferritin immunohistochemistry matched Fe XRF maps, revealing the most abundant reaction product in oligodendroglia of the DN hilus. In FRDA, these cells were smaller and more numerous than normal. In the atrophic DN gray matter of FRDA, anti-ferritin labeled mostly hypertrophic microglia. Immunohistochemistry and immunofluorescence of the Cu-responsive proteins Cu,Zn-superoxide dismutase and Cu(++)-transporting ATPase ?-peptide did not detect specific responses to Cu redistribution in FRDA. In contrast, metallothionein (MT)-positive processes were more abundant than normal and contributed to the gliosis of the DN. The isoforms of MT, MT-1/2, and brain-specific MT-3 displayed only limited co-localization with glial fibrillary acidic protein. The results suggest that MT can provide effective protection against endogenous Cu and Zn toxicity in FRDA, similar to the neuroprotective sequestration of Fe in holoferritin. PMID:22562713

Koeppen, Arnulf H; Ramirez, R Liane; Yu, Devin; Collins, Sarah E; Qian, Jiang; Parsons, Patrick J; Yang, Karl X; Chen, Zewu; Mazurkiewicz, Joseph E; Feustel, Paul J

2012-12-01

206

Bosonics in the copper and iron based high transition temperature superconductors  

NASA Astrophysics Data System (ADS)

It has been long established that the phenomenon of superconductivity is administered by lattice deformations (phonons) which act to pair electrons into spinless bosons free to condense into a coherent ground state. This superconducting phase is protected up to a critical temperature above which thermal fluctuations are potent enough to destroy the resistance free phase. The strength of this phonon mediation has been calculated by strong coupling theory and found to be capable of accommodating pairing up to near 40 K. So with the advent of copper-oxide (cuprate) superconductors boasting transitions temperatures exceeding 90 K it was clear that these material represented a new breed of superconducting physics. More than twenty years after the initial discovery of these high-transition temperatures the most basic questions are yet to be answered, the most fundamental of which is by what mechanism does pairing occur? The field splits between those who feel that a boson mediator is still necessary to act as the virtual glue which binds electrons into cooper pairs while others insist that really the Coulomb force alone is enough to induce pairing physics. Even within the boson-seeker community there is no consensus on what particular type of boson is contained in this system whether it be a lattice excitation or spin excitation. This answer has been clouded by previous experimental results on the hole-doped cuprates which have made strong cases for every scenario rendering them largely inconclusive. For this answer though it is possible to explore materials that have not yet been clouded by conflicting results by performing the first high resolution ultra-high-vacuum low-temperature scanning tunneling microscopy (STM) study of an electron-doped cuprate. A distinct and unambiguous bosonic mode is found at energy near 10.5 meV. Through comparison with other experimental data it is found that this mode does not fit the characteristics of a phonon. It is found, through comparison with neutron scattering experiments on the same sample, that this mode is consistent with a spin collective mode. Further more it is found that this mode is linked with the strength of superconductivity nominating it as the possible electron pairing mechanism. Doping and temperature dependence studies are performed to investigate this possibility. Finally the same procedures developed can be applied to the newly discovered iron based superconductors which may represent yet another type of new superconductor physics. Initial results on the first bosonic mode STM study of SrFe 2-xCoxAs 2 and BaFe2-xCo xAs2 are presented.

Niestemski, Francis Charles

207

Circulating Immune Complexes and trace elements (Copper, Iron and Selenium) as markers in oral precancer and cancer : a randomised, controlled clinical trial  

PubMed Central

Aim To evaluate the levels of circulating immune complexes, trace elements (copper, iron and selenium) in serum of patients with oral submucous fibrosis (OSMF), oral leukoplakia (L), and oral squamous cell carcinoma (SCC), analyze the alteration and identify the best predictors amongst these parameters for disease occurrence and progression. Methods Circulating immune complexes (CIC) were estimated using 37.5% Polyethylene Glycol 6000(PEG) serum precipitation. Serum estimation of copper (Cu), Iron (Fe) and selenium (Se) was done using the Oxalyl Dihydrazide method, Colorimetric Dipyridyl method and the Differential Pulse Cathodic Stripping Voltametry respectively. Results The data analysis revealed increased circulating immune complex levels in the precancer and cancer patients. Serum copper levels showed gradual increase from precancer to cancer patients. However, serum iron levels were decreased significantly in the cancer group. Selenium levels showed marked decrease in the cancer group. Among CIC, serum, copper, iron and selenium the best predictors for the occurrence of lesions were age, serum iron, CIC, serum selenium in the decreasing order. Conclusion The present study shows that these immunological and biological markers may be associated with the pathogenesis of oral premalignant and malignant lesions and their progressions. Concerted efforts would, therefore, help in early detection, management, and monitoring the efficacy of treatment.

Khanna, Sunali S; Karjodkar, Freny R

2006-01-01

208

Catalytic combustion of methane on substituted barium hexaaluminates  

Microsoft Academic Search

A sol–gel method using metallic barium, aluminum alkoxides and metal nitrates has been used to synthesize barium hexaaluminate partially substituted by either manganese, iron or both metal ions. The ?-alumina structure was obtained by calcination under oxygen at 1200°C. X-ray analysis revealed that formation of a pure single phase BaMxAl12?xO19 occurred up to x=4 for Fe, x=3 for Mn and

P Artizzu-Duart; J. M Millet; N Guilhaume; E Garbowski; M Primet

2000-01-01

209

Sputtered (barium(x), strontium(1-x))titanate, BST, thin films on flexible copper foils for use as a non-linear dielectric  

NASA Astrophysics Data System (ADS)

Ferroelectric thin film dielectrics have a non-linear DC bias dependent permittivity and can be used as the dielectric between metal electrodes to make tunable Metal-Insulator-Metal (MIM) capacitors. Varactors can be used to change the resonance frequency of a circuit allowing high speed frequency switching intra- and inter-band. 2-D geometric arrays of circuitry, where resonant frequency is independently controlled by tunable elements in each section of the array, allow electromagnetic radiation to be focused and the wave front spatial trajectory controlled. BST thin films varactors allow large DC fields to be applied with modest voltages providing large tunabilities. If ferroelectric thin film based devices are to complement or supplant semiconductor varactors as tunable elements then devices must be synthesized using a low cost processing techniques. The Film on Foil process methodology for depositing BST thin films on copper foil substrates was used to create BST/Cu specimens. Sputtering conditions were determined via BST deposition on platinized silicon. Sputtered BST thin films were synthesized on Cu foil substrates and densified using high T, controlled pO2 anneals. XRD showed the absence of Cu2O in as-deposited, post crystallization annealed, and post "re-ox" annealed state. Data showed a polycrystalline BST microstructure with a 55--80 nm grain size and no copper oxidation. HRTEM imaging qualitatively showed evidence of an abrupt BST/Cu interface free from oxide formation. Dielectric properties of Cu/BST/Pt MIM devices were measured as a function of DC bias, frequency, and temperature. A permittivity of 725 was observed with tunability >3:1 while zero bias tan delta of 0.02 saturating to tan delta < 0.003 at high DC bias. No significant frequency dispersion was observed over five decades of frequency. Temperature dependent measurements revealed a broad ferroelectric transition with a maximum at -32°C which sustains a large tunability over -150°C to 150°C. Sputtered BST thin films on copper foils show comparable dielectric properties to CVD deposited films on platinized silicon substrates proving sputtered BST/Cu specimens can reproduce excellent properties using a more cost-effective processing approach. A concept for reducing the temperature dependence was explored. Stacks of multiple compositions of BST thin films were considered as an extension of core-shell structures to a thin film format. Temperature profiles of BST/Cu films were modeled and mathematically combined in simulations of multi-composition film stacks. Simulations showed singular composition BST thin films could meet X7R specifications if a film has a 292 K < TC < 330 K. Simulations of series connected film stacks show only modest temperature profile broadening. Parallel connected dual composition film stacks showed a 75°C temperature range with essentially flat capacitance by simulating compositions that create a DeltaTC = 283°C. Maximum permittivity and temperature profile shape independent of film thickness or composition were assumed for simulations. BST/Cu thickness and compositions series were fabricated and dielectric properties characterized. These studies showed films could be grown from 300 nm and approaching 1 mum without changing the dielectric temperature response. In studying BST composition, an increasing TC shift was observed when increasing Ba mole fraction in BST thin films while tunability >3:1 was maintained. These results provide a route for creating temperature stable capacitors using a BST/Cu embodiment. An effort to reduce surface roughness of copper foil substrates adversely impacted BST film integrity by impairing adhesion. XPS analysis of high surface roughness commercially obtained Cu foils revealed a surface treatment of Zn-Cu-O that was not present on smooth Cu, thus an investigation of surface chemistry was conducted. Sessile drop experiments were performed to characterize Cu-BST adhesion and the effects of metallic Zn and ZnO in this system. The study revealed the work of adhesio

Laughlin, Brian James

210

Synthesis of a chitosan derivative recognizing planar metal ion and its selective adsorption equilibria of copper(II) over iron(III) 1  

Microsoft Academic Search

In order to improve the selectivity of copper(II)\\/iron(III), crosslinked N-(2-pyridyhnethyl)chitosan (PMC) with lower affinity for iron(III) was synthesized by crosslinking the Schiff's base formed in order to prevent amino groups to be metal adsorption sites from a attack of (chloromethyl)oxirane. The final chitosan derivative, PMC, was obtained by reducing the imine moiety of the Schiff's base with sodium borohydride. By

Yoshinari Baba; Koichi Masaaki; Yoshinobu Kawano

1998-01-01

211

Deuteron activation analysis for the determination of carbon in iron and copper oxide, reagents for 14 C-dating by accelerator mass spectrometry  

Microsoft Academic Search

In the14C-dating by accelerator mass spectrometry (AMS) iron and copper oxide are used during sample preparation. In an investigation on the origin of the14C-blank, which in practice determines the dating limit of AMS, the carbon contamination was measured in both reagents by deuteron activation analysis via the12C(d,n)13N reaction. A first batch of iron was analysed radiochemically and a carbon concentration

K. De Neve; K. Strijckmans; K. Vandeputte; R. Dams

1997-01-01

212

Domoic acid: The synergy of iron, copper, and the toxicity of diatoms  

Microsoft Academic Search

Diatom blooms generated by the alleviation of iron limitation in high nitrate-low chlorophyll (HNLC) regions of the oceans often are composed of pennate diatoms of the genus Pseudo-nitzschia, many of which periodically produce the potent neurotoxin domoic acid. We show that toxigenic diatoms have an inducible high-affinity iron uptake capability that enables them to grow efficiently on iron complexed by

Mark L. Wells; Charles G. Trick; William P. Cochlan; Margaret P. Hughes; Vera L. Trainer

2005-01-01

213

Removal of copper from carbon-saturated steel with an aluminum sulfide/iron sulfide slag.  

National Technical Information Service (NTIS)

Scrap iron and steel has long been considered a resource in the steel-making industry, and its value is largely determined by its impurity content. As the mini-mills, the major consumers of scrap iron and steel, expand into producing flat-rolled sheet, th...

A. Cohen M. Blander

1995-01-01

214

Preparing Copper Powder from Cemented Copper.  

National Technical Information Service (NTIS)

Techniques were developed for preparing metallurgical-grade copper powder from industrially produced cement copper. Flotation was used for rejecting discrete gangue particles, acid leaching to remove residual iron and aluminum, hydrogen reduction to elimi...

J. K. Winter L. G. Evans R. D. Groves

1971-01-01

215

IRON  

Technology Transfer Automated Retrieval System (TEKTRAN)

Iron is an essential mineral. Although abundant in nature, it is mostly insoluble and biological absorbable forms are limited to most organisms. Iron is of fundamental importance to a variety of iron-containing proteins, especially the oxygen-carrying molecules hemoglobin and myoglobin. Iron may als...

216

Identification of Genes Involved in the Toxic Response of Saccharomyces cerevisiae against Iron and Copper Overload by Parallel Analysis of Deletion Mutants  

Microsoft Academic Search

Iron and copper are essential nutrients for life as they are required for the function of many proteins but can be toxic if present in excess. Accumulation of these metals in the human body as a consequence of overload disorders and\\/or high environmental exposures has detrimental effects on health. The budding yeast Saccharomyces cerevisiae is an accepted cellular model for

William J. Jo; Alex Loguinov; Michelle Chang; Henri Wintz; Corey Nislow; Adam P. Arkin; Guri Giaever; Chris D. Vulpe

2008-01-01

217

The presence of traces of iron and copper ions during ?-irradiation does not result in clear mutational hot spots in the lacI gene  

Microsoft Academic Search

Oxidative radicals, which are produced during ionizing irradiation of DNA in water, damage the DNA and may result in mutations, which are in general randomly distributed. Alternatively, the addition of transition metal ions, like iron or copper, to DNA in combination with H2O2 and a reducing agent also results in the production of oxidative radicals. Due to binding of the

Carola A Wijker; M Vincent; M Lafleur

1999-01-01

218

Circulating Immune Complexes and trace elements (Copper, Iron and Selenium) as markers in oral precancer and cancer : a randomised, controlled clinical trial  

Microsoft Academic Search

AIM: To evaluate the levels of circulating immune complexes, trace elements (copper, iron and selenium) in serum of patients with oral submucous fibrosis (OSMF), oral leukoplakia (L), and oral squamous cell carcinoma (SCC), analyze the alteration and identify the best predictors amongst these parameters for disease occurrence and progression. METHODS: Circulating immune complexes (CIC) were estimated using 37.5% Polyethylene Glycol

Sunali S Khanna; Freny R Karjodkar

2006-01-01

219

Welding Procedure Specification: Gas Tungsten Arc Welding of Nickel-Copper to Nickel-Chromium-Iron. Supplement 1. Records of Procedure Qualification Tests.  

National Technical Information Service (NTIS)

Procedure WPS-2303-ASME-3 is qualified under Section IX of the ASME Boiler and Pressure Vessel Code for gas tungsten arc welding of nickel-copper N04400 (P-42) to nickel-chromium-iron N06600 (P-43), in thickness range of 0.035 to 0.432 inch; filler metal ...

C. H. Wodtke D. R. Frizzell W. A. Plunkett

1986-01-01

220

Barium and Radium Radiopolarography.  

National Technical Information Service (NTIS)

Radiopolarography has been applied to the study of two elements (barium and radium) which is difficult by classical polarography because of their strong electropositivity. Various parameters have been considered: nature, concentration and pH of supporting...

B. Fourest

1979-01-01

221

Photochemical aerobic detoxification of aqueous phenol and chlorophenol solutions promoted by iron salts and iron, vanadium, and copper oxides  

SciTech Connect

Phenol, 2,4,5-trichlorophenol, and pentachlorophenol in air in the presence of soluble iron salts or insoluble V{sub 2}O{sub 5}, Fe{sub 2}O{sub 3}, and CuO decompose in aqueous solution when irradiated by a luminescent lamp. The degree and the rate of decomposition are strongly influenced by the nature of the substrate and metal-containing promoter. As a result of decomposition, toxicity of solutions containing 2,4,5-trichlorophenol with respect to two types of living organisms - Protozoa (Tetrahymena pyriformis) and bacteria (Beneckea harveyi) - decreases significantly.

Nizova, G.V.; Bochkova, M.M.; Kozlova, N.B.; Shul`pin, G.B. [N.N. Semenov Institute of Chemical Physics, Moscow (Russian Federation)

1995-09-10

222

Evaluation of micronutrient (zinc, copper and iron) levels in periodontitis patients with and without diabetes mellitus type 2: A biochemical study.  

PubMed

Context: Periodontal tissue destruction is caused by an inappropriate host response to microorganisms. Diabetes is a metabolic disease and most of its complications are due to hyperglycemia. Periodontitis is considered as its sixth complication. Micronutrients such as zinc, copper and iron are essential for human health. There is accumulating evidence that the metabolism of several trace elements is altered in diabetes mellitus and that these nutrients might have specific roles in the pathogenesis and progress of this disease and its complication. An association between micronutrients and periodontitis has also been suggested by preliminary studies. However, till date there is a lack of relevant clinical data. Aim: This study was designed to estimate and compare the serum levels of zinc, copper and iron in diabetes mellitus type 2 patients and healthy individuals with and without periodontitis. Setting and Design: Single centre case-control study. Subjects and Materials: This study included 150 subjects, 50 in each group. Group 1 comprised of 50 subject with diabetes mellitus type 2 and periodontitis. Group 2 comprised of 50 subjects with chronic periodontitis and Group 3 comprised of 50 control subjects. Atomic absorption spectrophotometry method was used to measure clinical level of zinc and copper in serum. Estimation of serum iron levels was done by bathophenanthroline method. Statistical analysis: The results obtained were tabulated and subjected to statistical analysis by analysis of variance and Tukey multiple comparison tests using statistical software SPSS version 17. Results: The results showed that the serum levels of zinc decreased and serum levels of iron and copper increased in diabetes patients with periodontitis compared to healthy individuals with and without periodontitis. Conclusion: Imbalance of Zinc, copper and iron levels in the serum can predispose an individual to the risk of developing periodontitis. PMID:24047840

Thomas, Biju; Gautam, Anshuman; Prasad, B Rajendra; Kumari, Suchetha

223

Interaction of Copper with Iron, Iodine, and Thyroid Hormone Status in Goitrous Patients  

Microsoft Academic Search

In many developing countries, men and women are at high risk of goiter and iron deficiency. The aim of the recent study is\\u000a to assess the interaction of (Cu), with iron (Fe), iodine\\/iodide (I), and thyroid hormones in goitrous patients. Sixty goitrous\\u000a male (GMPs) and 72 female patients (GFPs) were evaluated for the Cu, Fe, I, and thyroid hormones status

Tasneem Gul Kazi; Ghulam Abbas Kandhro; Hassan Imran Afridi; Naveed Kazi; Jameel Ahmed Baig; Mohammad Balal Arain; Abdul Qadir Shah; Nasreen Syed; Sham Kumar; Nida Fatima Kolachi; Sumaira Khan

2010-01-01

224

Hot gas desulfurization with sorbents containing oxides of zinc, iron, vanadium and copper. Quarterly technical progress report, July 1992  

SciTech Connect

The main objective of this research is to evaluate the desulfurization performance of novel sorbents consisting of different combinations of zinc, iron, vanadium and copper oxides; and to develop a sorbent which can reduce H{sub 2}S levels to less than 1 ppmv, which can stabilize zinc, making operations above 650{degrees}C possible, and which can produce economically recoverable amounts of elemental sulfur during regeneration. This objective will be accomplished by evaluating the sorbent performance using fixed-bed and TGA experiments supported by sorbent characterization at various reaction extents. In the seventh quarter, the screening of the promoted sorbents in the packed bed reactor was continued. The results of this work were presented at the 1992 University Coal Research Contractors, Review Conference at Pittsburgh, PA.

Akyurtlu, A.; Akyurtlu, J.F.

1992-09-01

225

Copper, iron, zinc, and selenium dietary intake and status of Nepalese lactating women and their breast-fed infants.  

PubMed

The dietary intake of copper, iron, zinc, and selenium of 26 Nepalese lactating mothers was estimated from chemical analysis of 24-h food and beverage composites. Fasting blood and milk samples were obtained from the mothers and blood samples were obtained from the infants. The Nepalese mothers consumed significantly more Cu, significantly less Fe and Se, and similar amounts of Zn as compared with American lactating women. Blood Fe status indices and plasma concentrations of Cu, Zn, and Se were lower in the Nepalese mothers than in the American mothers. These lower values may in part be related to the high neutral detergent fiber and phytate content of the Nepalese diet, which could make these minerals less available for absorption. The high exposure to infections in Nepal may also depress Fe status indices and plasma Zn concentrations. The lower dietary Se intake of the Nepalese mothers was reflected in lower milk concentrations. PMID:3354498

Moser, P B; Reynolds, R D; Acharya, S; Howard, M P; Andon, M B; Lewis, S A

1988-04-01

226

Hot gas desulfurization with sorbents containing oxides of zinc, iron, vanadium and copper. Quarterly technical progress report  

SciTech Connect

The main objective of this research is to evaluate the desulfurization performance of novel sorbents consisting of different combinations of zinc, iron, vanadium and copper oxides; and to develop a sorbent which can reduce H{sub 2}S levels to less than 1 ppmv, which can stabilize zinc, making operations above 650{degrees}C possible, and which can produce economically recoverable amounts of elemental sulfur during regeneration. This objective will be accomplished by evaluating the sorbent performance using fixed-bed and TGA experiments supported by sorbent characterization at various reaction extents. The work done in the fourth quarter can be summarized as follows: (1) Calibration of the gas chromatograph for low and high H{sub 2}S and SO{sub 2} is completed. (2) The determination of surface areas and densities of the promoted sorbents is completed. (3) Preliminary screening of the promoted sorbents in the packed bed reactor has started.

Akyurtlu, A.

1991-10-01

227

Calculation of binodals and spinodals in multicomponent alloys by different statistical methods with application to iron-copper-manganese alloys  

SciTech Connect

A generalization of the pair-cluster (PC) approximation in the theory of disordered systems to multicomponent alloys is proposed. It is shown that phase equilibrium boundaries (binodals) calculated in the mean-field (MF) approximation, which is used in standard calculations of phase diagrams by the CALPHAD method, coincide with the results of rigorous calculations for dilute alloys; however, the application of these methods to calculating the boundaries of the stability region with respect to the decomposition of an alloy (spinodals) leads to large errors. At the same time, in the PC approximation, the description of all statistical properties, including binodals and spinodals, turns out to be exact for dilute alloys. The methods developed are illustrated by an example of iron-copper-manganese ternary alloys.

Vaks, V. G., E-mail: vaks@mbslab.kiae.ru; Zhuravlev, I. A.; Khromov, K. Yu. [Russian Research Centre Kurchatov Institute (Russian Federation)

2010-11-15

228

Interactions of free copper (II) ions alone or in complex with iron (III) ions with erythrocytes of marine fish Dicentrarchus labrax.  

PubMed

As a consequence of human activity, various toxicants - especially metal ions - enter aquatic ecosystems and many fish are exposed to considerable levels. As the free ion and in some complexes, there is no doubt that copper promotes damage to cellular molecules and structures through radical formation. Therefore, we have investigated the influence of copper uptake by the red blood of the sea bass (Dicentrarchus labrax), and its oxidative action and effects on cells in the presence of complexed and uncomplexed Fe3+ ions. Erythrocytes were exposed to various concentrations of CuSO4, Fe(NO3)3, and K3Fe(CN)6 for up to 5h, and the effects of copper ions alone and in the combination with iron determined. The results show that inside the cells cupric ion interacts with hemoglobin, causing methemoglobin formation by direct electron transfer from heme Fe2+ to Cu2+. Potassium ferricyanide as a source of complexed iron decreases Met-Hb formation induced by copper ions unlike Fe(NO3)3. We also found that incubation of fish erythrocytes with copper increased hemolysis of cells. But complexed and uncomplexed iron protected the effect of copper. CuSO4 increased the level of lipid peroxidation and a protective effect on complexed iron was observed. Incubation of erythrocytes with copper ions resulted in the loss of a considerable part of thiol content at 10 and 20 microM. This effect was decreased by potassium ferricyanide and Fe(NO3)3 only after 1 and 3h of incubation. The level of nuclear DNA damage assayed by comet assay showed that 20 microM CuSO4 as well as 20 microM Fe(NO3)3 and 10 mM K3Fe(CN)6 induce single- and double-strand breaks. The lower changes were observed after the exposure of cells to K3Fe(CN)6. The data suggest that complexed iron can act protectively against copper ions in contrast to Fe(NO3)3. PMID:19524693

Labieniec, Magdalena; Milowska, Katarzyna; Balcerczyk, Aneta; Rucinska, Agata; Sadowska, Magdalena; Jokiel, Marta; Brichon, Gerard; Gabryelak, Teresa

2009-06-12

229

Assessment of zerovalent iron for stabilization of chromium, copper, and arsenic in soil  

Microsoft Academic Search

Stabilization of soil contaminated with trace elements is a remediation practice that does not reduce the total content of contaminants, but lowers the amounts of mobile and bioavailable fractions. This study evaluated the efficiency of Fe0 to reduce the mobility and bioavailability of Cr, Cu, As and Zn in a chromated copper arsenate (CCA)-contaminated soil using chemical, biochemical and biotoxicity

Jurate Kumpiene; Solvita Ore; Giancarlo Renella; Michel Mench; Anders Lagerkvist; Christian Maurice

2006-01-01

230

The Phalabowra (Palabora) carbonatite-hosted magnetite–copper sulfide deposit, South Africa: an end-member of the iron-oxide copper–gold–rare earth element deposit group?  

Microsoft Academic Search

Olympic Dam-type iron-oxide copper–gold deposits are widely recognised in terrains with significant Palaeoproterozoic to\\u000a Mesoproterozoic granitic magmatism. Most researchers favour a magmatic association for these deposits, but none of the 100–2000?Mt\\u000a recognised copper-bearing deposits has a spatial and\\/or temporal relationship to an intrusive body of sufficient dimensions\\u000a to produce the hosting giant breccia and\\/or hydrothermal systems. In other words, if

David I. Groves; Noreen M. Vielreicher

2001-01-01

231

Iron  

MedlinePLUS

... high in calories but low in vitamins and minerals. Sugar sweetened sodas and most desserts are examples ... higher doses of iron supplementation [ 86 ]. Iron and mineral interactions Some researchers have raised concerns about interactions ...

232

The Crd1 gene encodes a putative di-iron enzyme required for photosystem I accumulation in copper deficiency and hypoxia in Chlamydomonas reinhardtii  

PubMed Central

Chlamydomonas reinhardtii adapts to copper deficiency by degrading apoplastocyanin and inducing Cyc6 and Cpx1 encoding cytochrome c6 and coproporphyrinogen oxidase, respectively. To identify other components in this pathway, colonies resulting from insertional mutagenesis were screened for copper- conditional phenotypes. Twelve crd (copper response defect) strains were identified. In copper-deficient conditions, the crd strains fail to accumulate photosystem I and light-harvesting complex I, and they contain reduced amounts of light-harvesting complex II. Cyc6, Cpx1 expression and plastocyanin accumulation remain copper responsive. The crd phenotype is rescued by a similar amount of copper as is required for repression of Cyc6 and Cpx1 and for maintenance of plastocyanin at its usual stoichiometry, suggesting that the affected gene is a target of the same signal transduction pathway. The crd strains represent alleles at a single locus, CRD1, which encodes a 47 kDa, hydrophilic protein with a consensus carboxylate-bridged di-iron binding site. Crd1 homologs are present in the genomes of photosynthetic organisms. In Chlamydomonas, Crd1 expression is activated in copper- or oxygen-deficient cells, and Crd1 function is required for adaptation to these conditions.

Moseley, Jeffrey; Quinn, Jeanette; Eriksson, Mats; Merchant, Sabeeha

2000-01-01

233

IRON  

EPA Science Inventory

The document surveys the effects of organic and inorganic iron that are relevant to humans and their environment. The biology and chemistry of iron are complex and only partially understood. Iron participates in oxidation reduction processes that not only affect its geochemical m...

234

Lower GI Series (Barium Enema)  

MedlinePLUS

... because the large intestine is filled with barium liquid. The barium liquid coats the lining of the large intestine and ... bowel prep instructions. Generally, patients follow a clear liquid diet for 1 to 3 days before the ...

235

Iron Absorption by Infants.  

National Technical Information Service (NTIS)

The research team studied absorption of iron from carefully selected iron-fortified foods that are now commercially available or are attractive candidates for future iron fortification. Because of possible adverse interactions with zinc and copper when in...

S. J. Fomon

1995-01-01

236

Solubilization of Cu 2+ from copper ore by iron-oxidizing bacteria isolated from the natural environment and identification of the enzyme that determines Cu 2+ solubilization activity  

Microsoft Academic Search

Solubilization of Cu2+ from copper concentrate by 67 strains of iron-oxidizing bacteria isolated from the natural environment was studied. In the case of static growth on copper concentrate (5%)-salt medium (pH 2.5) at 30°C, Cu2+ solubilization activities of 65 strains including Thiobacillus ferrooxidans strains AP19-3, OK-2, OK-3, OK1–50, Funis and NASF-1 ranged from 2.5–3.5 mg Cu2+\\/ml\\/33 d. In contrast, the

Tsuyoshi Sugio; Fauzia Akhter

1996-01-01

237

Experimental analysis of iron impact on heavy metal (copper) migration in the soil  

Microsoft Academic Search

The paper focusses on analysis of the impact of iron particles on heavy metals migration in the soil within the northern area of Klaipeda city. The city has been chosen due to its function as a transit harbour locating 19 big companies related to the sea business and cargo services. Like every ecosystem, the soil is characterized by accumulating different

Vaidotas Vaišis; Lidija Šuksta

2010-01-01

238

The effect of copper additions to the mechanical properties of austempered ductile iron (ADI)  

Microsoft Academic Search

Previous unpublished studies into the wear behaviour of austempered ductile irons have shown that under sliding conditions, the mechanism is one of the initial delaminations followed by so generated third body wear. Microstructural examination indicated that the sub-surface crack propagation (which lead to the delamination) was initiating at graphite spheroids in the ADI. This is similar to that type of

P. W. Shelton; A. A. Bonner

2006-01-01

239

Effect of copper content on the microstructure and mechanical properties of a modified nodular iron  

Microsoft Academic Search

During the drilling operation of two crankshafts, both made of modified nodular iron, the drilling tool failed in one of them and a failure analysis was conducted on the two crankshafts. Results indicate that in the crankshaft where the drilling tool failed had a finer pearlitic microstructure with a higher hardness compared with the other. This difference in the microstructure

M. A. Neri; C. Carreño

2003-01-01

240

Rosette iron deficiency transcript and microRNA profiling reveals links between copper and iron homeostasis in Arabidopsis thaliana  

PubMed Central

Iron (Fe) is an essential plant micronutrient, and its deficiency limits plant growth and development on alkaline soils. Under Fe deficiency, plant responses include up-regulation of genes involved in Fe uptake from the soil. However, little is known about shoot responses to Fe deficiency. Using microarrays to probe gene expression in Kas-1 and Tsu-1 ecotypes of Arabidopsis thaliana, and comparison with existing Col-0 data, revealed conserved rosette gene expression responses to Fe deficiency. Fe-regulated genes included known metal homeostasis-related genes, and a number of genes of unknown function. Several genes responded to Fe deficiency in both roots and rosettes. Fe deficiency led to up-regulation of Cu,Zn superoxide dismutase (SOD) genes CSD1 and CSD2, and down-regulation of FeSOD genes FSD1 and FSD2. Eight microRNAs were found to respond to Fe deficiency. Three of these (miR397a, miR398a, and miR398b/c) are known to regulate transcripts of Cu-containing proteins, and were down-regulated by Fe deficiency, suggesting that they could be involved in plant adaptation to Fe limitation. Indeed, Fe deficiency led to accumulation of Cu in rosettes, prior to any detectable decrease in Fe concentration. ccs1 mutants that lack functional Cu,ZnSOD proteins were prone to greater oxidative stress under Fe deficiency, indicating that increased Cu concentration under Fe limitation has an important role in oxidative stress prevention. The present results show that Cu accumulation, microRNA regulation, and associated differential expression of Fe and CuSOD genes are coordinated responses to Fe limitation.

Waters, Brian M.; Stein, Ricardo J.

2012-01-01

241

Abundant, seasonally variable supply of glacier flour-derived iron drives high nitrate consumption in Copper River plume and adjacent Gulf of Alaska continental shelf  

NASA Astrophysics Data System (ADS)

Recent work has suggested that high iron supply may contribute to a northward increase in phytoplankton biomass along the U.S. west coast, consistent with “bottom-up” control of these coastal ecosystems. We examine this hypothesis in waters of the Copper River plume and nearby continental shelf in the northern Gulf of Alaska (GoA). These are the first data we know of examining “bottom up” control of this coastal ecosystem by the supply of nitrate and iron. These are also the first data we know of that examine seasonal variability in the mechanisms that supply iron to this region, and in the iron concentrations. High concentrations (several hundred nM) of “total dissolveable” Fe (unfiltered, pH ~2) were present in surface waters spanning the continental shelf in early April 2010, from resuspension of fine glacial flour. Concentrations decreased dramatically beyond the shelf break. This fine particulate matter represents a large source of “dissolved” Fe to these waters. Surface-water nitrate concentrations were fairly uniform (~15 uM) across the entire shelf at this time, due to deep winter mixing. By late July this shelf particulate Fe source is greatly diminished, owing to strong stratification. Yet there is abundant “total dissolveable” Fe (several mM) at this time from the Copper River plume (largest single freshwater source to the GoA) and lower (several hundred nM) concentrations in the AK coastal current (that reflect the cumulative impact of melting glaciers from further south). By late July this abundant supply of iron in the Copper River vicinity, together with strong stratification, lead to complete consumption of surface-water nitrate across the entire shelf (and extending tens of km beyond the shelf). These data are consistent with the idea that high primary productivity in this region is fueled by abundant wintertime surface-water nitrate, together with iron supply from fine, labile, glacier-derived particulate matter from seasonally variable sources.

Crusius, J.; Schroth, A. W.; Campbell, R. W.; Nielsen, J. L.; Hoyer, I. R.; Brooks, W.

2010-12-01

242

Trace determination of iron, cobalt, nickel and copper in zirconium fluoride by substoichiometric radioactivation analysis  

Microsoft Academic Search

Trace amounts of transition elements (Fe, Co, Ni and Cu) in zirconium fluoride and NBS SRM's were determined by substoichiometric radioactivation analysis. The contents of impurities in sublimed sample were less than those of high-purity material and of reagent grade. The detection limits of these elements in zirconium fluoride were 10 ng\\/g for iron, 0.01 ng\\/g for cobalt, 1 ng\\/g

K. Kobayashi; T. Shigematsu

1987-01-01

243

Heat treatment of copper-alloy cast irons with spheroidal graphite  

Microsoft Academic Search

The Ukrainian Scientific-Research Institute of Metallurgy has developed cast irons with 1.5-4.0% Ni, 0.1-0.5% Mo, and 1.5-3.3% Cu and which are intended for the fabrication of rolls for the finishing stands of structural and merchant mills producing hot-rolled products [I-3]. In the cast state [i] and after a second kind of annealing (heating to 1000°C and cooling at a rate

V. I. Vakula; T. S. Skoblo; V. A. Dubrov

1987-01-01

244

Phytotoxicity and some interactions of the essential trace metals iron, manganese, molybdenum, zinc, copper, and boron  

Microsoft Academic Search

The essential trace elements Fe, Mn, Zn, Cu, and B in high concentrations can produce phytotoxicities. Iron toxicity resulted from 5 × 10 M and 10 M FeSO4, but not from equivalent amounts of FeEDDHA (ferric ethylenediamine di (o?hydroxyphenylacetic acid) ). Leaf concentrations in bush beans of 465 ?g Mn\\/g, 291 ?g B\\/g, and 321 ?g Zn\\/g all on the

A. Wallace; E. M. Romney; G. V. Alexander; J. Kinnear

1977-01-01

245

Semiconducting barium titanate  

Microsoft Academic Search

Barium titanate, which is well known as a basic ferroelectric material, is also of interest when doped because of the interaction between semiconductivity and ferroelectricity. The resistance of blocking layers at surfaces and grain-boundaries is governed mainly by the ferroelectric properties, so that a resistance jump of four decades is observed on heating above the Curie temperature. A survey of

W. Heywang

1971-01-01

246

Carbon and oxygen isotope constraints on fluid sources and fluid–wallrock interaction in regional alteration and iron-oxide–copper–gold mineralisation, eastern Mt Isa Block, Australia  

Microsoft Academic Search

The source of metasomatic fluids in iron-oxide–copper–gold districts is contentious with models for magmatic and other fluid sources having been proposed. For this study, ?\\u000a 18O and ?\\u000a 13C ratios were measured from carbonate mineral separates in the Proterozoic eastern Mt Isa Block of Northwest Queensland, Australia. Isotopic analyses are supported by petrography, mineral chemistry and cathodoluminescence imagery. Marine meta-carbonate

Lucas J. Marshall; Nicholas H. S. Oliver; Garry J. Davidson

2006-01-01

247

Influence of Copper, Iron, Zinc and Fe 3 + Haemoglobin Levels on the Etiopathogenesis of Chronic Calcific Pancreatitis—A Study in Patients with Pancreatitis  

Microsoft Academic Search

Chronic pancreatitis is a serious condition associated with severe abdominal pain, and a significant percentage of patients\\u000a progresses to irreversible calcification in pancreas. The present study evaluates the degree to which the levels of trace\\u000a elements, copper, iron, selenium, zinc and haemoglobin-Fe3+, in blood, serum and pancreas have any role to play in the calcification process associated with fibrosis in

Geetha Arumugam; Monika Padmanaban; Dhanya Krishnan; Saranya Panneerselvam; Surendran Rajagopal

2011-01-01

248

Determination of Copper, Iron, Nickel, and Zinc in Ethanol Fuel by Flame Atomic Absorption Spectrometry Using On?Line Preconcentration System  

Microsoft Academic Search

In this work, an on?line system for preconcentration and determination of copper, iron, nickel, and zinc at µg L level by flame atomic absorption spectrometry (FAAS) has been developed. Amberlite XAD?4 functionalized with 3,4?dihydroxybenzoic acid packed in a minicolumn was used as metal sorbent. The retained metals can be quickly eluted from sorbent material, with the eluent stream consisting of hydrochloric

Leonardo S. G. Teixeira; Marcos de A. Bezerra; Valfredo A. Lemos; Hilda C. dos Santos; Djane S. de Jesus; Antônio C. S. Costa

2005-01-01

249

Reconnaissance-scale conceptual fuzzy-logic prospectivity modelling for iron oxide copper-gold deposits in the northern Fennoscandian Shield, Finland  

Microsoft Academic Search

The conceptual approach used in this study incorporates spatial analysis techniques for data integration and analysis to perform reconnaissance-scale mineral prospectivity mapping for iron oxide copper – gold (IOCG) mineralisation in Finland. The known IOCG occurrences in Finland are characterised by the following features: (i) an epigenetic magnetite-rich host-rock; (ii) an association of Fe – Cu – Au ± Co ± U; (iii) ore minerals comprising magnetite, chalcopyrite, pyrite or

V. Nykänen; D. I. Groves; V. J. Ojala; P. Eilu; S. J. Gardoll

2008-01-01

250

Comparative study of alloxan effects in copper-loaded and iron-loaded rats: lipid peroxidation, protein oxidation, proteasome and antioxidant enzyme activities  

Microsoft Academic Search

The in-vivo effects of alloxan on protein oxidation and lipid peroxidation, as well as on proteasome and antioxidant enzyme activities\\u000a in liver and kidney of copper-loaded and iron-loaded rats, were studied. In control animals, a single alloxan dose (120 mg\\/kg,\\u000a i.p.) increased blood-glucose concentration at the 24th hr and 48th hr and, especially, on the 5th day. For these periods

Albena Alexandrova; Almira Georgieva; Lubomir Petrov; Elina Tsvetanova; Margarita Kirkova

2006-01-01

251

Effects of free iron oxyhydrates and soil organic matter on copper sorption-desorption behavior by size fractions of aggregates from two paddy soils  

Microsoft Academic Search

Effects of free iron oxyhydrates (Fed) and soil organic matter (SOM) on copper (Cu2+) sorption-desorption behavior by size fractions of aggregates from two typical paddy soils (Ferric-Accumulic Stagnic Anthrosol (Soil H) and Gleyic Stagnic Anthrosol (Soil W)) were investigated with and without treatments of dithionite-citrate-bicarbonate and of H2O2. The size fractions of aggregates were obtained from the undisturbed bulk topsoil

Fang WANG; Genxing PAN; Lianqing LI

2009-01-01

252

Effect of excess dietary iron as ferrous sulfate and excess dietary ascorbic acid on liver zinc, copper and sulfhydryl groups and the ovary  

Microsoft Academic Search

Female guinea pigs of the NIH 13\\/N strain, weighing between 475 and 512 g, were fed diets supplemented with 50 to 2500 mg of iron per kg of diet as ferrous sulfate and 0.2 to 8.0 g of ascorbic acid per kg of diet. A significant effect was observed on tissue copper and zinc, ovary weight and liver protein sulfhydryl

C. H. Edwards; J. S. Adkins; B. Harrison

1986-01-01

253

Electron transfer characterization of iron and cobalt porphyrins and copper complexes, and of their metal-carbon and metal-oxygen bond energies  

Microsoft Academic Search

The electron-transfer and oxidation-reduction chemistry for the alkyl-iron and alkyl-cobalt porphyrins [(Por)M-R] and copper complexes has been investigated on the basis of cyclic voltammetric and controlled-potential-electrolysis measurements. Half-wave potentials for the oxidation and the reduction of (Por)M-R are directly influenced by the nature of the electron-donating or electron-withdrawing groups on the porphyrin ring and the structure of the alkyl groups.

Qui; Aimin

1992-01-01

254

Welding procedure specification: gas tungsten arc welding of nickel-copper to nickel-chromium-iron. Supplement 1. Records of procedure qualification tests  

SciTech Connect

Procedure WPS-2303-ASME-3 is qualified under Section IX of the ASME Boiler and Pressure Vessel Code for gas tungsten arc welding of nickel-copper N04400 (P-42) to nickel-chromium-iron N06600 (P-43), in thickness range of 0.035 to 0.432 inch; filler metal is ERNiCu-7 (F-42); shielding gas is argon.

Wodtke, C.H.; Frizzell, D.R.; Plunkett, W.A.

1986-06-01

255

Copper, zinc, and iron concentrations in blood serum and diet of dairy cattle on semi-industrial farms in central Iran  

Microsoft Academic Search

The aim of this study was to evaluate the blood serum and diet concentrations of copper, zinc, and iron in Holstein dairy\\u000a cattle kept under semi-industrial farming in Isfahan province, central Iran. Moreover, the effects of season, pregnancy, and\\u000a daily milk yield on serum Cu, Zn, and Fe concentrations were also evaluated. The study was carried out on 12 semi-industrial

Vahid Noaman; Mohsen Rasti; Ahmad Reza Ranjbari; Edris Shirvani

256

Effect of pressure on the behavior of copper-, iron-, and nickel-based oxygen carriers for chemical-looping combustion  

SciTech Connect

This work analyzes the main characteristics related to the chemical looping combustion (CLC) process necessary to use the syngas obtained in an integrated gasification combined cycle (IGCC) power plant. The kinetics of reduction with H{sub 2} and CO and oxidation with O{sub 2} of three high-reactivity oxygen carriers used in the CLC system have been determined in a thermogravimetric analyzer at atmospheric pressure. The iron- and nickel-based oxygen carriers were prepared by freeze-granulation, and the copper-based oxygen carrier was prepared by impregnation. The changing grain size model (CGSM) was used for the kinetic determination, assuming spherical grains for the freeze-granulated particles containing iron and nickel and a platelike geometry for the reacting surface of the copper-based impregnated particles. The dependence of the reaction rates on temperature was low, with the activation energy values varying from 14 to 33 kJ mol{sup -1} for the reduction and 7 to 15 kJ mol{sup -1} for the oxidation. The reaction order depended on the reacting gas and oxygen carrier, with values ranging from 0.25 to 1. However, an increase in the operating pressure for the IGCC + CLC system increases the thermal efficiency of the process, and the CO{sub 2} is recovered as a high pressure gas, decreasing the energy demand for further compression. The effect of pressure on the behavior of the oxygen carriers has been analyzed in a pressurized thermogravimetric analyzer at 1073 K and pressures up to 30 atm. It has been found that an increase in total pressure has a negative effect on the reaction rates of all the oxygen carriers. Moreover, the use of the CGSM with the kinetic parameters obtained at atmospheric pressure predicted higher reaction rates than those experimentally obtained at higher pressures, and therefore, the kinetic parameters necessary to design pressurized CLC plants must be determined at the operating pressure. 34 refs., 8 figs., 2 tabs.

Francisco Garcia-Labiano; Juan Adanez; Luis F. de Diego; Pilar Gayan; Alberto Abad [Instituto de Carboquimica (CSIC), Zaragoza (Spain). Department of Energy and Environment

2006-02-01

257

Nickel-cobalt-iron-copper sulfides and arsenides in solution-collapse breccia pipes, northwestern Arizona  

SciTech Connect

An extensive suite of Ni-Co-Fe-Cu sulfides and arsenides lies within the matrix of solution-collapse breccias buried deep within the plateaus of the Grand Canyon region. Ceilings over large caverns in the Redwall collapsed, brecciating the overlying sandstone and forming cylindrical breccia pipes up to 300 ft in diameter that extend vertically as much as 3,000 ft. These highly permeable breccias served as a host for the precipitation of a suite of over 100 minerals, including uraninite, sphalerite, galena and various copper phases, in addition to the Ni-Co-bearing-phase discussed here. Intricately zoned crystals of small (<1 mm), euhedral Ni-Co-Fe-As-S minerals were the first to form during the second major episode of mineralization in these pipes. Several of these phases replace minerals, such as barite and anhydrite, from the first episode. Extensive microprobe work has been done on samples from two breccia pipe mines, the Hack 2 and Orphan, which are about 50 miles apart. Mineral compositions are similar except that no copper is found in the Ni-Co-Fe phases from the Hack 2 mine, while pyrites containing 1 wt % Cu are common from the Orphan, which was mined for copper. In some of these pyrites', Cu is dominant and the mineral is actually villamaninite. Pyrites from both mines characteristically contain 0.5 to 3 wt % As. Metal contents in zones pyrite-bravoite-vaesite (M[sub 1]S[sub 2]) crystals at the Hack 2 mine range from Fe[sub 1] to Fe[sub .12], Ni[sub 0] to Ni[sub .86], and Co[sub 0] to Co[sub .10]. The metal content for polydymite-siegenite-violarite averages about (Ni[sub 2.33]Co[sub .39]Fe[sub .23])(S[sub 3.9]As[sub .1]). Orphan mine pyrite-bravoite-vaesite-villamaninite ranges in composition from pure FeS[sub 2] to (Ni[sub .6]Fe[sub .21]Co[sub .17])S[sub 2], and (Cu[sub .46]Ni[sub .27]Fe[sub .21]Co[sub .13])S[sub 2]. Of all the sulfides or arsenides found in these breccia pipes, only nickeline consistently occurs as the pure end member.

Wenrich, K.J. (Geological Survey, Denver, CO (United States)); Hlava, P.F. (Sandia National Labs., Albuquerque, NM (United States))

1993-04-01

258

Enthalpies of formation of borides of iron, cobalt, and nickel by solution calorimetry in liquid copper  

Microsoft Academic Search

The enthalpies of formation at 1385 ?2 K of the following crystalline borides have been determined by high temperature solution\\u000a calorimetry using liquid copper as the calorimetric solvent. Fe2B-67.87 ?8.05 kJ mol?1, Co2B -58.1 ?7.0 kJ mol?1, Ni2B -67.66 ?4.12 kJ ml?1, FeB-64.63 ?4.34 kJ mol?1, CoB -69.52 ?6.0 kJ mol?1, and NiB -40.2 ?3.77 kJ mol?1. The enthalpy of

Seichi Sato; O. J. Kleppa

1982-01-01

259

Interaction of copper with iron, iodine, and thyroid hormone status in goitrous patients.  

PubMed

In many developing countries, men and women are at high risk of goiter and iron deficiency. The aim of the recent study is to assess the interaction of (Cu), with iron (Fe), iodine/iodide (I), and thyroid hormones in goitrous patients. Sixty goitrous male (GMPs) and 72 female patients (GFPs) were evaluated for the Cu, Fe, I, and thyroid hormones status in biological samples (serum and urine), and compared to non-goitrous subjects of both genders (M = 106, F = 120). The biological samples were analyzed for Cu and Fe concentration using atomic absorption spectrometer, while I was measured by the potentiometric method, prior to microwave-assisted acid digestion (MD). Quality control for the method was established with certified samples. Significantly higher mean values of Cu in serum, and urine samples of GMPs and GFPs, while lower value of Fe and I were observed as compared to control subjects (p < 0.015), respectively. The mean values of free triiodothyronine (FT3) and free thyroxin (FT4) were found to be lower in goitrous patients of both genders than in the age-matched healthy controls (p < 0.006 and 0.002), respectively, in contrast high mean values of thyroid-stimulating hormone (TSH) were detected in patients (p < 0.009), as compared to non-goitrous subjects. It was observed that the deficiencies of Fe, I, and thyroid hormone in goitrous patients could be influenced by efficiency of Cu. PMID:19693445

Kazi, Tasneem Gul; Kandhro, Ghulam Abbas; Afridi, Hassan Imran; Kazi, Naveed; Baig, Jameel Ahmed; Arain, Mohammad Balal; Shah, Abdul Qadir; Syed, Nasreen; Kumar, Sham; Kolachi, Nida Fatima; Khan, Sumaira

2009-08-08

260

Electrochromic multilayer films of tunable color by combination of copper or iron complex and monolacunary dawson-type polyoxometalate.  

PubMed

Electrochromic multilayer films consisting of polyoxometalate (POM) cluster alpha-K(10)[P(2)W(17)O(61)].17H(2)O (P(2)W(17)), copper(II) complex [Cu(II)(phen)(2)](NO(3))(2) (phen = 1,10-phenithroline), and iron complex [Fe(II)(phen)(3)](ClO(4))(2) were fabricated on silicon, quartz and ITO substrates by layer-by-layer self-assembly method. The multilayer films, PSS/Cu(II)(phen)(2)/[(P(2)W(17)/Cu(II)(phen)(2))](n) and PSS/Fe(II)(phen)(3)/[(P(2)W(17)/Fe(II) (phen)(3))](n) were characterized by UV-vis spectra, X-ray photoelectron spectra, cyclic voltammetry (CV), chronoamperometric (CA) and in-situ spectral electrochemical measurements. The interesting feature of the electrochromic film is its adjustable color by reduction of both transition metal complex and polyoxometalate at different potentials. The multilayer films also exhibit high optical contrast, suitable response time and low operation potential due to the presence of mono-lacunary-substituted polyoxometalate and transition metal complex. This is the first example that the color of electrochromic film can be adjustable, which gives valuable information for exploring new electrochromic materials with tunable colors. PMID:16852064

Gao, Guanggang; Xu, Lin; Wang, Wenju; An, Wenjia; Qiu, Yunfeng; Wang, Zhenqing; Wang, Enbo

2005-05-12

261

Macrosegregation and sedimentation in liquid phase sintering: Specific studies in the nickel-tungsten system and iron-copper system  

NASA Astrophysics Data System (ADS)

Based on experimental results, a macrosegregation model has been proposed to explain sedimentation occurring in liquid phase sintering (LPS). Macrosegregation has been observed both in the sintering process of nickel-tungsten (Ni-W) alloys and iron-copper (Fe-Cu) alloys. The experimental results indicate that whether the mushy zone is located at the top or at the bottom of the sample, macrosegregation can occur if a nonuniform structure is formed during LPS. The initial particle settling or floating gives rise to the liquid composition gradient. Elimination of the gradient requires substantial time and is accompanied by a retreat of the mushy zone. At the same time, the mass in the mushy zone is transported to the liquid zone. If the initial settling does not happen, macrosegregation will not appear. But a "true" sedimentation can be observed. These two types of sedimentation were compared and the rates were quasi-quantitatively estimated. A numerical simulation model has been developed to simulate the macrosegregation process. This calculation provided a further understanding of the sedimentation mechanisms.

Xu, Lei

262

Barium carbonate intoxication  

Microsoft Academic Search

A 22-year-old man attempted to commit suicide by swallowing an unknown amount of barium carbonate dissolved in hydrochloric acid. Shortly after ingestion, he developed crampy abdominal pain and generalized muscle weakness. About 2 h later, respiratory failure ensued necessitating orotracheal intubation and mechanical ventilation. Concomitantly, life-threatening arrhythmias including ventricular fibrillation occurred, and he had to be resuscitated for 45 min.

Th. F. Schorn; Ch. Olbricht; A. Schüler; A. Franz; K. Wittek; H.-J. Balks; E. Hausmann; H.-H. Wellhoener

1991-01-01

263

Barium Vanadate Microspheres  

NASA Astrophysics Data System (ADS)

It has been found that many glass powders can form micro- or nanospheres when heated in a flame or by a laser. Much of the research in this area of microspheres has concentrated on making hollow spheres, called microballoons, of silica and borosilicate glasses. Our aim was to create highly porous barium vanadate microspheres for possible future applications in material storage. The surface area of porous spheres would provide a greater amount of bonding surface area for dopants than hollow spheres. Barium vanadate glass with a molar fraction of 0.4 to 0.6 barium oxide was used because this glass is stable and has a low Tg. Size distributions of the spheres were quantified and the extent of sphere formation and porosity was examined using a scanning electron microscope. The size of spheres formed is affected by powder size, dropping method, and flame position. The porosity of the microspheres is affected by flame temperature, time spent in flame, and the material onto which the spheres fall. The greatest porosity was achieved by first heating the glass powder at a low temperature and then immediately sending it through the flames of two MAPP gas torches at approximately 2100^oC onto a metal sheet.

Yosinski, Shari; Tweeton, Landon; Feller, Steve; Affatigato, Mario

2009-11-01

264

Microstructural Evolution and Mechanical Properties of Fusion Welds in an Iron-Copper-Based Multicomponent Steel  

NASA Astrophysics Data System (ADS)

NUCu-140 is a copper-precipitation-strengthened steel that exhibits excellent mechanical properties with a relatively simple chemical composition and processing schedule. As a result, NUCu-140 is a candidate material for use in many naval and structural applications. Before NUCu-140 can be implemented as a replacement for currently used materials, the weldability of this material must be determined under a wide range of welding conditions. This research represents an initial step toward understanding the microstructural and mechanical property evolution that occurs during fusion welding of NUCu-140. Microhardness traverses and tensile testing using digital image correlation show local softening in the heat-affected zone (HAZ). Microstructural characterization using light optical microscopy (LOM) revealed very few differences in the softened regions compared with the base metal. Local-electrode atom-probe (LEAP) tomography demonstrates that local softening occurs as a result of dissolution of the Cu-rich precipitates. MatCalc kinetic simulations (Vienna, Austria) were combined with welding heat-flow calculations to model the precipitate evolution within the HAZ. Reasonably good agreement was obtained between the measured and calculated precipitate radii, number density, and volume fraction of the Cu-rich precipitates in the weld. These results were used with a precipitate-strengthening model to understand strength variations within the HAZ.

Farren, Jeffrey D.; Hunter, Allen H.; Dupont, John N.; Seidman, David N.; Robino, Charles V.; Kozeschnik, Ernst

2012-11-01

265

Adsorption and decomposition of hydrazine on metal films of iron, nickel, and copper  

SciTech Connect

The interaction of hydrazine with evaporated metal films of Fe, Ni, and Cu has been investigated in the temperature range 243-393 K. Dissociative chemisorption of hydrazine occurred on Fe and Ni films at 243 K with liberation of NH/sub 3/, N/sub 2/, and H/sub 2/ gases. Adsorption on Cu film at the same temperature was molecular and a significant fraction of the adsorption was reversible. Two different mechanisms have been suggested for the adsorption and the subsequent formation of the decomposition products. Ammonia was the main gaseous product of hydrazine decomposition on the films at all temperatures. The desorption of the products was more extensive in the case of Ni film as compared with the other two metals. The activation energy (E/sub a/) of hydrazine adsorption as well as the pre-exponential factor (A) in the rate equation remained independent of extent of adsorption. The relationship which was found to exist between the values of log A and those of E/sub a/ indicated the operation of a compensation effect in the hydrazine adsorption on the films. Copper film was found to have a greater capability for hydrazine adsorption than the other two films. The geometric requirements for appropriate hydrazine adsorption on this metal are probably more satisfied than on the other two metals. 27 references, 6 figures, 4 tables.

Al-Haydari, Y.K.; Saleh, J.M.; Matloob, M.H.

1985-07-18

266

Properties of Semiconductive Barium Titanates  

Microsoft Academic Search

The resistivity of barium titanate which is usually of the order of 109˜1012 ohm-cm, may be remarkably reduced with suitable control in valency. The valency-controlled barium titanate, whose resistivity is of the order of 10˜104 ohm-cm at room temperature, shows anomalous positive character in the temperature dependency of the resistivity. For example, the resistivity of barium titanate containing 0.1 mol.

Osamu Saburi

1959-01-01

267

75 FR 33824 - Barium Chloride From China  

Federal Register 2010, 2011, 2012, 2013

...731-TA-149 (Third Review)] Barium Chloride From China Determination On the basis...the antidumping duty order on barium chloride from China would be likely to lead to...4157 (June 2010), entitled Barium Chloride from China: Investigation No....

2010-06-15

268

75 FR 19657 - Barium Chloride From China  

Federal Register 2010, 2011, 2012, 2013

...731-TA-149 (Third Review)] Barium Chloride From China AGENCY: United States International...the antidumping duty order on barium chloride from China...the antidumping duty order on barium chloride from China would be likely to lead...

2010-04-15

269

Adsorption of nickel and copper onto natural iron oxide-coated sand from aqueous solutions: study in single and binary systems.  

PubMed

Natural iron oxide-coated sand (NCS), extracted from the iron ore located in North-West of Tunisia, was employed to investigate its capacity to remove copper and nickel from aqueous solutions. The aim of this work was to characterize the considered sorbent (NCS) and to assess the possibility of removing nickel and copper from aqueous solutions by this sorbent. The effects of agitation time, pH, initial metal ion concentration and temperature on the removal of these metals were studied. In order to study the sorption isotherm, two equilibrium models, the Freundlich and Langmuir isotherms, were analyzed. The effect of solution pH on the adsorption onto NCS was studied in the pH range from 2 to 7 and 2 to 9 for copper and nickel respectively. The adsorption was endothermic and the computation of the parameters, DeltaH degrees, DeltaS degrees and DeltaG degrees, indicated that the interactions were thermodynamically favourable. Experiments with Cu and Ni adsorption measured together showed that Cu severely interfered with Ni adsorption to the NCS and vice versa under the conditions of the two coexisted ions adsorption. PMID:18701213

Boujelben, N; Bouzid, J; Elouear, Z

2008-07-11

270

Barium isotope fractionation in the global barium cycle: Evidence from barium minerals and precipitation experiments  

NASA Astrophysics Data System (ADS)

In this study, we present first results from an ongoing investigation on the stable barium (Ba) isotope fractionation in the natural barium cycle. Stable Ba isotope signatures of international IAEA reference materials (synthetic barium sulfate and barium carbonate), and terrestrial Ba gangue minerals have been analyzed as a first approach to evaluate potential discriminating processes in the global geochemical barium cycle. Measurements were carried out on a multi-collector ICP-MS applying a 130Ba/135Ba double spike. Data are given as per mil deviations from a laboratory Ba nitrate standard solution in the d137/134Ba notation (external 2s stdev < 0.1 per mil). Whereas the various synthetic solid standards and p.a. quality synthetic barium chloride show very similar isotope results close to the nitrate standard solution, the terrestrial barium gangue minerals (four barites, one norsethite [BaMg(CO3)2]) were depleted in the heavy isotope (d137/134Ba values between 0 and -0.2 per mil). A natural barite, from an unknown Chinese locality, gave an isotope value of -0.4 per mil. Also measured high 34S/32S and 18O/16O ratios in this sample indicate that this barite has been formed under influence of microbial sulfate reduction, probably in a marine diagenetic environment. The observed natural discriminations are by far larger than the analytical uncertainty of the isotope measurements, indicating isotope discrimination in the natural barium cycle. Precipitation experiments from aqueous barium chloride solutions at temperatures of 20° and 80°C indicate that the light Ba isotope is enriched in pure barium carbonate or barium sulfate compared to the aqueous solution. A maximum isotope fractionation of -0.3 per mil is observed, for both barium carbonate and sulfate, that seems to be influenced by precipitation rate (BaCO3) and/or the aqueous speciation, but less by temperature.

von Allmen, Katja; Böttcher, Michael E.; Samankassou, Elias; Nägler, Thomas F.

2010-05-01

271

Production of free radicals arising from the surface activity of minerals and oxygen. Part II. Arsenides, sulfides, and sulfoarsenides of iron, nickel, and copper.  

PubMed

The excess incidence of lung cancers observed in metallic mines other than iron mines probably can be correlated not only to radioactivity, but also to dust pollution. The present work investigates the role of surface properties of sulfides and arsenides, which are present in metal mines, in oxidizing mechanisms capable of inducing oxidative stress and, possibly, of participating in carcinogenesis. Using added spin-trapping agent followed by ESR spectroscopy, it was observed that nickel and copper arsenides can be very active in the oxidation of formate or DMSO, by reducing the oxygen dissolved in a cell-free medium. Sulfides, on the other hand, are not active, except for the iron sulfides, which are very active as an air-aged powder. The process of activation and rendering the particle surface passive was investigated. Surface dissolution and moderate grinding were found to be activating factors, while air-aging generally rendered the particle surface passive. The critical factor in determining activity is the availability of reducing species of iron, copper, or nickel on the surface of the minerals. PMID:2626758

Costa, D; Guignard, J; Pezerat, H

1989-12-01

272

Synthesis and structure of an "iron-doped" copper selenide cluster molecule: [Cu30Fe2Se6(SePh)24(dppm)4].  

PubMed

CuCl and bis(diphenylphosphanyl)methane (dppm) react in the presence of small amounts of FeCl(3) with PhSeSiMe(3) and Se(SiMe(3))(2) to yield [Cu(30)Fe(2)Se(6)(SePh)(24)(dppm)(4)]. The crystal structure of the compound was determined by single-crystal X-ray analysis to give a mixed copper selenide/selenolate cluster molecule of a new structural type incorporating two central iron atoms. The formal oxidation state of the iron atoms was determined by Mössbauer spectroscopy to be +3, in agreement with quantum chemical calculations and modeling of the magnetic data. In addition, Mössbauer studies show no magnetic hyperfine structure in zero field, and the magnetically perturbed spectrum displays a pattern typical for a diamagnetic species in a transverse field, suggesting a singlet ground state. However, the inclusion of the iron atoms has a distinct influence on the optical properties of the compound compared to similar clusters containing only copper and selenium atoms. PMID:19691303

Eichhöfer, Andreas; Olkowska-Oetzel, Jolanta; Fenske, Dieter; Fink, Karin; Mereacre, Valeriu; Powell, Annie K; Buth, Gernot

2009-09-21

273

Mechanism of copper transport at the blood-cerebrospinal fluid barrier: influence of iron deficiency in an in vitro model.  

PubMed

Copper (Cu) is an essential trace element that requires tight homeostatic regulation to ensure appropriate supply while not causing cytotoxicity due to its strong redox potential. Our previous in vivo study has shown that iron deficiency (FeD) increases Cu levels in brain tissues, particularly in the choroid plexus, where the blood-cerebrospinal fluid (CSF) barrier resides. This study was designed to elucidate the mechanism by which FeD results in excess Cu accumulation at the blood-CSF barrier. The effect of FeD on cellular Cu retention and transporters Cu transporter-1 (Ctr1), divalent metal transporter 1 (DMT1), antioxidant protein-1 (ATOX1) and ATP7A was examined in choroidal epithelial Z310 cells. The results revealed that deferoximine treatment (FeD) resulted in 70% increase in cellular Cu retention (P < 0.05). A significant increase in the mRNA levels of DMT1, but not Ctr1, was also observed after FeD treatment, suggesting a critical role of DMT1 in cellular Cu regulation during FeD. Knocking down Ctr1 or DMT1 resulted in significantly lower Cu uptake by Z310 cells, whereas the knocking down of ATOX1 or ATP7A led to substantial increases of cellular retention of Cu. Taken together, these results suggest that Ctr1, DMT1, ATOX1 and ATP7A contribute to Cu transport at the blood-CSF barrier, and that the accumulation of intracellular Cu found in the Z310 cells during FeD appears to be mediated, at least in part, via the upregulation of DMT1 after FeD treatment. PMID:22442359

Monnot, Andrew D; Zheng, Gang; Zheng, Wei

2012-03-01

274

Barium uranyl diphosphonates  

SciTech Connect

Three Ba{sup 2+}/UO{sub 2}{sup 2+} methylenediphosphonates have been prepared from mild hydrothermal treatment of uranium trioxide, methylendiphosphonic acid (C1P2) with barium hydroxide octahydrate, barium iodate monohydrate, and small aliquots of HF at 200 Degree-Sign C. These compounds, Ba[UO{sub 2}[CH{sub 2}(PO{sub 3}){sub 2}]{center_dot}1.4H{sub 2}O (Ba-1), Ba{sub 3}[(UO{sub 2}){sub 4}(CH{sub 2}(PO{sub 3}){sub 2}){sub 2}F{sub 6}]{center_dot}6H{sub 2}O (Ba-2), and Ba{sub 2}[(UO{sub 2}){sub 2}(CH{sub 2}(PO{sub 3}){sub 2})F{sub 4}]{center_dot}5.75H{sub 2}O (Ba-3) all adopt layered structures based upon linear uranyl groups and disphosphonate molecules. Ba-2 and Ba-3 are similar in that they both have UO{sub 5}F{sub 2} pentagonal bipyramids that are bridged and chelated by the diphosphonate moiety into a two-dimensional zigzag anionic sheet (Ba-2) and a one-dimensional ribbon anionic chain (Ba-3). Ba-1, has a single crystallographically unique uranium metal center where the C1P2 ligand solely bridges to form [UO{sub 2}[CH{sub 2}(PO{sub 3}){sub 2}]{sup 2-} sheets. The interlayer space of the structures is occupied by Ba{sup 2+}, which, along with the fluoride ion, mediates the structure formed and maintains overall charge balance. - Graphical abstract: Illustration of the stacking of the layers in Ba{sub 3}[(UO{sub 2}){sub 4}(CH{sub 2}(PO{sub 3}){sub 2}){sub 2})F{sub 6}]{center_dot}6H{sub 2}O viewed along the c-axis. The structure is constructed from UO{sub 7} pentagonal bipyramidal units, U(1)O{sub 7}=gray, U(2)O{sub 7}=yellow, barium=blue, phosphorus=magenta, fluorine=green, oxygen=red, carbon=black, and hydrogen=light peach. Highlights: Black-Right-Pointing-Pointer The polymerization of the UO{sub 2}{sup 2+} sites to form uranyl dimers leads to structural variations in compounds. Black-Right-Pointing-Pointer Barium cations stitch uranyl diphosphonate anionic layers together, and help mediate structure formation. Black-Right-Pointing-Pointer HF acts as both a mineralizing agent and a ligand.

Nelson, Anna-Gay D., E-mail: nelsoa@umich.edu [Department of Civil Engineering and Geological Sciences and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (United States); Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109-1005 (United States); Alekseev, Evgeny V. [Institute of Energy and Climate Research (IEK-6), Forschungszentrum Juelich Wilhelm-Johnen-Strasse, Juelich 52428 (Germany); Ewing, Rodney C. [Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109-1005 (United States); Albrecht-Schmitt, Thomas E. [Department of Civil Engineering and Geological Sciences and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (United States)

2012-08-15

275

Effects of silicon, copper and iron on static and dynamic properties of alloy 206 (aluminum-copper) in semi-solids produced by the SEED process  

NASA Astrophysics Data System (ADS)

The advantages of producing metal parts by rheocasting are generally recognised for common foundry alloys of Al-Si. However, other more performing alloys in terms of mechanical properties could have a great interest in specialized applications in the automotive industry, while remaining competitive in the forming. Indeed, the growing demand for more competitive products requires the development of new alloys better suited to semi-solid processes. Among others, Al-Cu alloys of the 2XX series are known for their superior mechanical strength. However, in the past, 2XX alloys were never candidates for pressure die casting. The main reason is their propensity to hot tearing. Semi-solid processes provide better conditions for molding with the rheological behavior of dough and molding temperatures lower reducing this type of defect. In the initial phase, this research has studied factors that reduce hot tearing susceptibility of castings produced by semi-solid SEED of alloy 206. Subsequently, a comparative study on the tensile properties and fatigue was performed on four variants of the alloy 206. The results of tensile strength and fatigue were compared with the specifications for applications in the automotive industry and also to other competing processes and alloys. During this study, several metallurgical aspects were analyzed. The following main points have been validated: i) the main effects of compositional variations of silicon, iron and copper alloy Al-Cu (206) on the mechanical properties, and ii) certain relationships between the mechanism of hot cracking and the solidification rate in semi-solid. Parts produced from the semi-solid paste coming from the SEED process combined with modified 206 alloys have been successfully molded and achieved superior mechanical properties than the requirements of the automotive industry. The fatigue properties of the two best modified 206 alloys were higher than those of A357 alloy castings and are close to those of the wrought alloy AA6061. At present, there is simply no known application for pressure die-cast alloy with 206 (Liquid Die-casting). This is mainly due to the high propensity to hot cracking and limitations facing the part geometry and the subsequent assembly. This study demonstrated that in addition to pieces produced by semi-solid die-casting using large variations in chemical composition, the SEED process allows obtaining spare sound (sound part) and more complex geometry. Moreover, as the semi-solid parts have less porosity, they can also be machined and welded for some applications. The conclusions of this study demonstrate significant progress in identifying the main issues related to the feasibility of die-casting good parts with high performance using the modified 206 alloy combined with SEED process. This work is therefore a baseline work in the development of new Al-Cu alloys for industries of semi-solid and, at the same time, for the expansion of aluminum for high performance applications in the industry. N.B. This thesis is part of a research project developed by the NSERC / Rio Tinto Akan Industrial Research Chair in Metallurgy of Innovative Aluminum Transformation (CIMTAL).

Lemieux, Alain

276

Reversed-phase high-performance liquid chromatography of iron(II) and copper(II) chelates with 4,7-diphenyl-1,10-phenanthroline disulfonate  

Microsoft Academic Search

The chromatographic behaviour of negatively-charged iron(II) and copper(II) chelates with 4,7-diphenyl-1,10-phenanthroline (bathophenanthroline) disulfonate (BPS) on a reversed-phase Inertsil ODS-2 column was studied by using methanol–water (60:40, v\\/v) containing 0.02 M tetramethylammonium bromide (TMAB) and 0.025 M tris(hydroxymethyl)aminomethane (Tris)–HCl at pH 7.5 as a mobile phase. The possibility that the hydrophilic Tris–HCl buffer also serves as a counter ion together with

X Mudasir; Meiko Arai; Naoki Yoshioka; Hidenari Inoue

1998-01-01

277

Simultaneous high performance liquid chromatographic determination of vanadium, nickel, iron and copper in crude petroleum oils using bis(acetylpivalylmethane)ethylenediimine as a complexing reagent.  

PubMed

A method is described for the simultaneous high performance liquid chromatographic (HPLC) determination of copper, iron, nickel and vanadium, based on complexation of analytes by bis(acetylpivalylmethane)ethylenediimine (H(2)APM(2)en) followed by solvent extraction and HPLC separation on a reversed-phase. C-18, 5 microm column with UV detection at 260 nm. The method has been applied to the determination of metals in crude petroleum oils collected from the South Indus Basin oil fields. The results obtained are compared with those obtained by flame atomic absorption spectrometry. PMID:18966546

Khuhawar, M Y; Lanjwani, S N

1996-05-01

278

Highly aluminium doped barium and strontium ferrite nanoparticles prepared by citrate auto-combustion synthesis  

Microsoft Academic Search

Aluminium doped barium and strontium hexaferrite nanoparticles BaAlxFe(12?x)O19 and SrAlxFe(12?x)O19 were synthesised via a sol–gel route using citric acid to complex the ions followed by an auto-combustion reaction. This method shows promise for the synthesis of complex ferrite powders with small particle size. It was found that around half of the iron could be substituted for aluminium in the barium

Neil J.. Shirtcliffe; Simon Thompson; Eoin S. O’Keefe; Steve Appleton; Carole C.. Perry

2007-01-01

279

Barium iron arsenide, barium cobalt arsenide, barium nickel arsenide single crystals and superconductivity upon cobalt doping  

SciTech Connect

The crystal structure and physical properties of BaFe{sub 2}As{sub 2}, BaCo{sub 2}As{sub 2}, and BaNi{sub 2}As{sub 2} single crystals are surveyed. BaFe{sub 2}As{sub 2} gives a magnetic and structural transition at T{sub N} = 132(1) K, BaCo{sub 2}As{sub 2} is a paramagnetic metal, while BaNi{sub 2}As{sub 2} has a structural phase transition at T{sub 0} = 131 K, followed by superconductivity below {Tc} = 0.69 K. The bulk superconductivity in Co-doped BaFe{sub 2}As{sub 2} below {Tc} = 22 K is demonstrated by resistivity, magnetic susceptibility, and specific heat data. In contrast to the cuprates, the Fe-based system appears to tolerate considerable disorder in the transition metal layers. First principles calculations for BaFe{sub 1.84}Co{sub 0.16}As{sub 2} inter-band scattering due to Co is weak.

Ronning, Filip [Los Alamos National Laboratory; Sefat, A S [ORNL; Mcguire, M M [ORNL; Sales, B [ORNL; Jin, R [ORNL; Mandrus, D [ORNL

2009-01-01

280

Characterization of iron- and sulphide mineral-oxidizing moderately thermophilic acidophilic bacteria from an Indonesian auto-heating copper mine waste heap and a deep South African gold mine  

Microsoft Academic Search

Iron- and chalcopyrite-oxidizing enrichment cultures were obtained at 50°C from acidic, high-temperature, copper\\/gold mine environments in Indonesia and South Africa. Over 90% copper yield was obtained from chalcopyrite concentrate with the Indonesian enrichment in 3 months with 2% solids concentration, when pH was maintained at around 2. Neither addition of silver cations nor an enhanced nutrient concentration influenced chalcopyrite leaching. Excision

Päivi H.-M. Kinnunen; Jaakko A. Puhakka

2004-01-01

281

Direct functionalization processes: a journey from palladium to copper to iron to nickel to metal-free coupling reactions.  

PubMed

The possibility of finding novel disconnections for the efficient synthesis of organic molecules has driven the interest in developing technologies to directly functionalize C-H bonds. The ubiquity of these bonds makes such transformations attractive, while also posing several challenges. The first, and perhaps most important, is the selective functionalization of one C-H bond over another. Another key problem is inducing reactivity at sites that have been historically unreactive and difficult to access without prior inefficient prefunctionalization. Although remarkable advances have been made over the past decade toward solving these and other problems, several difficult tasks remain as researchers attempt to bring C-H functionalization reactions into common use. The functionalization of sp(3) centers continues to be challenging relative to their sp and sp(2) counterparts. Directing groups are often needed to increase the effective concentration of the catalyst at the targeted reaction site, forming thermodynamically stable coordination complexes. As such, the development of removable or convertible directing groups is desirable. Finally, the replacement of expensive rare earth reagents with less expensive and more sustainable catalysts or abandoning the use of catalysts entirely is essential for future practicality. This Account describes our efforts toward solving some of these quandaries. We began our work in this area with the direct arylation of N-iminopyridinium ylides as a universal means to derivatize the germane six-membered heterocycle. We found that the Lewis basic benzoyl group of the pyridinium ylide could direct a palladium catalyst toward insertion at the 2-position of the pyridinium ring, forming a thermodynamically stable six-membered metallocycle. Subsequently we discovered the arylation of the benzylic site of 2-picolonium ylides. The same N-benzoyl group could direct a number of inexpensive copper salts to the 2-position of the pyridinium ylide, which led to the first description of a direct copper-catalyzed alkenylation onto an electron-deficient arene. This particular directing group offers two advantages: (1) it can be easily appended and removed to reveal the desired pyridine target, and (2) it can be incorporated in a cascade process in the preparation of pharmacologically relevant 2-pyrazolo[1,5-a]pyridines. This work has solved some of the challenges in the direct arylation of nonheterocyclic arenes, including reversing the reactivity often observed with such transformations. Readily convertible directing groups were applied to facilitate the transformation. We also demonstrated that iron can promote intermolecular arylations effectively and that the omission of any metal still permits intramolecular arylation reactions. Lastly, we recently discovered a nickel-catalyzed intramolecular arylation of sp(3) C-H bonds. Our mechanistic investigations of these processes have elucidated radical pathways, opening new avenues in future direct C-H functionalization reactions. PMID:23098328

Mousseau, James J; Charette, André B

2012-10-26

282

Minor-element behavior and iron partition during the cleaning of copper converter slag under reducing conditions  

Microsoft Academic Search

A mathematical model has been developed to describe the reduction process and the minor-element behavior during the cleaning of copper converter slag under equilibrium conditions. The results of simulation show that large fractions of Pb, Bi, Sb and As, but little of Zn, are absorbed into the recovered copper phase. Generally, the distribution behavior of minor elements is affected by

Hang Goo Kim; H. Y. Sohn

1997-01-01

283

Serum levels of calcium, selenium, magnesium, phosphorus, chromium, copper and iron--their relation to zinc in rats with induced hypothyroidism.  

PubMed

There is an important relation between thyroid hormones and zinc. Establishment of low zinc levels in hypothyroidism and high levels in hyperthyroidism is a significant proof of this relation. The aim of the present study was to explore changes in serum levels of some elements and their relation to zinc in rats with hypothyroidism. Thirty adult male rats of Sprague-Dawley type were divided into 3 equal groups: group 1, control; group 2, sham-hypothyroidism group supplemented with 10 mg/kg serum physiologic i.p. for 4 weeks; and group 3, hypothyroidism group supplemented with 10 mg/kg propylthiouracil i.p. for 4 weeks. Blood samples were collected from all animals by decapitation and serum calcium, phosphorus, chromium, copper, iron, magnesium, selenium and zinc levels were analyzed using an atomic emission apparatus. Group 3 had lower calcium, selenium and zinc levels, and higher chromium, copper, iron and phosphorus levels (p < 0.01 all) relative to groups 1 and 2. Study parameters did not differ between groups 1 and 2. Results obtained in this study indicate that hypothyroidism leads to changes in serum levels of some elements in rats. These changes may be associated with reduced zinc levels in hypothyroidism. PMID:24053074

Baltaci, Abdulkerim Kasim; Mogulkoc, Rasim; Belviranli, Muaz

2013-06-01

284

Simultaneous Determination of Iron, Copper and Cobalt in Food Samples by CCD-diode Array Detection-Flow Injection Analysis with Partial Least Squares Calibration Model  

NASA Astrophysics Data System (ADS)

A flow injection-CCD diode array detection spectrophotometry with partial least squares (PLS) program for simultaneous determination of iron, copper and cobalt in food samples has been established. The method was based on the chromogenic reaction of the three metal ions and 2- (5-Bromo-2-pyridylazo)-5-diethylaminophenol, 5-Br-PADAP in acetic acid - sodium acetate buffer solution (pH5) with Triton X-100 and ascorbic acid. The overlapped spectra of the colored complexes were collected by charge-coupled device (CCD) - diode array detector and the multi-wavelength absorbance data was processed using partial least squares (PLS) algorithm. Optimum reaction conditions and parameters of flow injection analysis were investigated. The samples of tea, sesame, laver, millet, cornmeal, mung bean and soybean powder were determined by the proposed method. The average recoveries of spiked samples were 91.80%~100.9% for Iron, 92.50%~108.0% for Copper, 93.00%~110.5% for Cobalt, respectively with relative standard deviation (R.S.D) of 1.1%~12.1%. The sampling rate is 45 samples h-1. The determination results of the food samples were in good agreement between the proposed method and ICP-AES.

Mi, Jiaping; Li, Yuanqian; Zhou, Xiaoli; Zheng, Bo; Zhou, Ying

2006-01-01

285

Microstructural Evolution and Mechanical Properties of Fusion Welds and Simulated Heat-Affected Zones in an Iron-Copper Based Multi-Component Steel  

NASA Astrophysics Data System (ADS)

NUCu-140 is a copper-precipitation strengthened steel that exhibits excellent mechanical properties with a relatively simple chemical composition and processing schedule. As a result, NUCu-140 is a candidate material for use in many naval and structural applications. Before NUCu-140 can be implemented as a replacement for currently utilized materials, a comprehensive welding strategy must be developed under a wide range of welding conditions. This research represents an initial step toward understanding the microstructural and mechanical property evolution that occurs during fusion welding of NUCu-140. The following dissertation is presented as a series of four chapters. Chapter one is a review of the relevant literature on the iron-copper system including the precipitation of copper in steel, the development of the NUCu family of alloys, and the formation of acicular ferrite in steel weldments. Chapter two is a detailed study of the precipitate, microstructural, and mechanical property evolution of NUCu-140 fusion welds. Microhardness testing, tensile testing, local-electrode atom probe (LEAP) tomography, MatCalc kinetic simulations, and Russell-Brown strengthening results for gas-tungsten and gas-metal arc welds are presented. Chapter three is a thorough study of the microstructural and mechanical property evolution that occurs in the four critical regions of the HAZ. Simulated HAZ specimens were produced and evaluated using microhardness, tensile testing, and charpy impact testing. MatCalc simulations and R-B strengthening calculations were also performed in an effort to model the experimentally observed mechanical property trends. Chapter 4 is a brief investigation into the capabilities of MatCalc and the R-B model to determine if the two techniques could be used as predictive tools for a series of binary iron-copper alloys without the aid of experimentally measured precipitate data. The mechanical property results show that local softening occurs in the heat-affected zone (HAZ) as a result of either full or partial dissolution of the copper-rich precipitates responsible for strengthening. Re-precipitation of the copper-rich precipitates was observed during the cooling portion of the weld thermal cycle but the resultant precipitate phase fractions were too low to fully recover the lost strength. The coarse-grained HAZ and fusion zone exhibited an acicular type microstructure which led to improved tensile properties when compared to the other regions of the HAZ. MatCalc simulations displayed excellent agreement with the precipitate parameters measured experimentally using the LEAP. The R-B model was shown to provide reasonable agreement under select conditions, but in general was determined to be overly sensitive to small variations in precipitate parameters. As a result in should be considered a qualitative tool only for precipitate radii less than ˜2 nm. Finally, it was determined that the current generation of MatCalc software was unable to accurately capture the precipitate evolution of various binary iron-copper alloys when experimental data sets were not available for calibration of the model parameters.

Farren, Jeffrey David

286

Effect of chronic ethanol ingestion on the metabolism of copper, iron, manganese, selenium, and zinc in an animal model of alcoholic cardiomyopathy  

SciTech Connect

Alcoholic cardiomyopathy (AC) is one of the diseases caused by alcohol abuse, and there has been considerable debate about the possibility that nutritional factors may be important in the etiology of AC. In addition, there is evidence that ethanol may affect the metabolism of trace elements. The purpose of this investigation was to determine if chronic ethanol administration produces changes in the metabolism of the essential metals copper, iron, manganese, zinc, and selenium using an animal model of AC. Eighteen male Sprague-Dawley rats were divided into three groups; an ad libitum control group (AL), a pair-fed control group (PF), and an ethanol-dosed group (ETOH). The latter group received gradually increasing concentrations (5-25%) of ethanol in the drinking water for 15 wk. Food intake was monitored and urine and feces collected for a 4-d period during the study to determine ethanol effects on trace-element balance. Growth of both the PF and ETOH animals was inhibited. Ethanol produced substantial increases in liver manganese and decreases in liver copper and zinc. Metal concentrations in heart and concentrations in other tissues studied (spleen, testes, brain, bone, kidney, and muscle) did not differ significantly among the groups, except for testes selenium and kidney zinc. Reduced food intake and ethanol ingestion were associated with a reduced percentage of ingested selenium excreted in the urine. Deficiencies of copper, iron, manganese, selenium, and zinc in myocardial tissue are not likely to be involved in the pathogenesis of AC in the rat. 38 references, 1 figure, 4 tables.

Bogden, J.D.; Al-Rabiai, S.; Gilani, S.H.

1984-01-01

287

Discovery of the barium isotopes  

SciTech Connect

Thirty-eight barium isotopes have been observed so far and the discovery of these isotopes is discussed here. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

Shore, A.; Fritsch, A.; Ginepro, J.Q.; Heim, M.; Schuh, A. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Thoennessen, M., E-mail: thoennessen@nscl.msu.ed [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States)

2010-11-15

288

Iron, manganese and copper emitted by cargo and passenger trains in Zürich (Switzerland): Size-segregated mass concentrations in ambient air  

NASA Astrophysics Data System (ADS)

Particle emissions caused by railway traffic have hardly been investigated in the past, due to their obviously minor influence on air quality compared to automotive traffic. In this study, emissions related to particle abrasion from wheels and tracks were investigated next to a busy railway line in Zürich (Switzerland), where trains run nearly exclusively with electrical locomotives. Hourly size-segregated aerosol samples (0.1-1, 1-2.5 and 2.5-10 ?m) were collected with a rotating drum impactor (RDI) and subsequently analyzed by synchrotron radiation X-ray fluorescence spectrometry (SR-XRF). In this way, hourly elemental mass concentrations were obtained for chromium, manganese, iron and copper, which are the elements most relevant for railway abrasion. Additionally, daily aerosol filters were collected at the same site as well as at a background site for subsequent analysis by gravimetry and wavelength dispersive XRF (WD-XRF). Railway related ambient air concentrations of iron and manganese were calculated for the coarse (2.5-10 ?m) and fine (<2.5 ?m) particle fraction by means of a Mn/Fe ratio investigation. The comparison to train type and frequency data showed that 75% and 60% of the iron and manganese mass concentrations related to cargo and passenger trains, respectively, were found in the coarse mode. The railway related iron mass concentration normalized by the train frequency ranges between 10 and 100 ng m -3 h iron in 10 m distance to the tracks, depending on train type. It is estimated that the personal exposure next to a busy railway line above ground is more than a magnitude lower than inside a subway station.

Bukowiecki, Nicolas; Gehrig, Robert; Hill, Matthias; Lienemann, Peter; Zwicky, Christoph N.; Buchmann, Brigitte; Weingartner, Ernest; Baltensperger, Urs

289

Suicidal poisoning with barium chloride.  

PubMed

A 49-year-old male pharmacist suffering from depression phoned the emergency services telling of how he had ingested barium chloride. He was found semicomatose in bed and resuscitation attempts were to no avail and he died at the scene. A white plastic container labelled "Barium chloride... Poison", and a book with a writing on a blank page... "give sulphate... SO(4)" were found. At autopsy, 1l of whitish-yellow fluid was found in the stomach. Autopsy barium levels were: blood 9.9mg/l; bile 8.8mg/l; urine 6.3mg/l; gastric 10.0g/l. Cause of death was given as cardiorespiratory arrest due to barium chloride poisoning. The issue of barium toxicity in a variety of itatrogenic and non itatrogenic situation is discussed together with the two only other cases of suicidal barium ingestion, and the feasibility of early intervention at the scene by an emergency team. PMID:11376995

Jourdan, S; Bertoni, M; Sergio, P; Michele, P; Rossi, M

2001-06-15

290

Simultaneous determination of manganese, iron and cobalt in copper with a multi-element graphite furnace atomic absorption spectrometer  

Microsoft Academic Search

A simple method was developed for the determination of trace metals (Mn, Fe and Co) in copper simultaneously using a multi-element graphite furnace atomic absorption spectrometer (Perkin-Elmer SIMAA6000) equipped with a transversely heated graphite atomizer. Copper was dissolved in nitric acid before analysis using a microwave digestion system. Pd(NO3)2 with the special gas (5% H2 in Ar) was used as

Chun-Hao Chiu; Yu-Hsiang Sung; Shang-Da Huang

2003-01-01

291

Metal ions as potential regulatory factors in the biosynthesis of red hair pigments: a new benzothiazole intermediate in the iron or copper assisted oxidation of 5- S-cysteinyldopa  

Microsoft Academic Search

In the presence of iron or copper ions, the course of the oxidation in air of 5-S-cysteinyldopa (1), the main biosynthetic precursor of pheomelanins and trichochromes, was markedly changed affording two main products. One of these was identified as the oxobenzothiazine 8, previously obtained under nonphysiologically relevant conditions, while the other was characterized as the novel hydroxybenzothiazole 9. Besides 8

Paola Di Donato; Alessandra Napolitano; Giuseppe Prota

2002-01-01

292

Entrainment behavior of copper and copper matte in copper smelting operations  

Microsoft Academic Search

In copper smelting, the loss of copper to the slag due to entrainment is largely influenced by the flotation of copper metal\\u000a and\\/or matte in the slag phase. To evaluate this behavior, the surface tension of copper as a function of temperature and\\u000a oxygen pressure and the interfacial tension of the copper-iron matte-slag system as a function of matte grade

S. W. Ip; J. M. Toguri

1992-01-01

293

Built-Up Films of Barium Stearate and Their Optical Properties  

Microsoft Academic Search

The technique of depositing successive single layers of molecules of various stearates on a solid surface is described. Films containing 3001 layers have been built of barium-copper stearate. A photograph shows films built in a series of steps having intervals of 2 molecular layers. The contrast of the steps is plainly visible when the slide is illuminated by polarized light

Katharine B. Blodgett; Irving Langmuir

1937-01-01

294

Formation of yttrium barium cuprate powder at low temperatures  

SciTech Connect

Yttrium barium cuprate can be formed at temperatures below 800{degrees}C from mixed oxides and carbonate if a low-oxygen-pressure atmosphere is used. This eliminates the formation of a high-oxygen-content nonsuperconducting phase which has been previously shown to form at lower temperatures. Reaction of barium carbonate and the oxides of copper and yttrium at temperatures as low as 750{degrees}C in reducing atmospheres is shown to form tetragonal YBa{sub 2}Cu{sub 3}O{sub x} with x about 6. This compound can then be oxidized by cooling in an oxidizing atmosphere to obtain the desired x value of about 7.

Lay, K.W. (Research and Development Center, General Electric Co., Schenectady, NY (US))

1989-04-01

295

Removal of Tin and Copper from Liquid Iron by Al2O3-Saturated Ca-CaCl2 Slags at 1448 to 1648 K  

NASA Astrophysics Data System (ADS)

The removal of tin and copper from liquid iron by Al2O3-saturated Ca-CaCl2 slags was carried out in separate alumina crucibles at 1448 to 1648 K that showed small partition ratios of less than 1. The tin content of the liquid iron typically decreased from its initial value of 50 to 40 wt pct and the (gross) copper content of the iron-copper mixture from 50 to 45 wt pct, at equilibrium. The small refining efficiencies (37 pct, maximum) of the slags, the initial composition of which were, in most cases, Ca-50 wt pct CaCl2, may be attributed to the significant dissolution in them of alumina, up to 42.0 wt pct (29.6 mol pct), in experiments with Sn, and up to 54.4 wt pct (38.6 mol pct), in experiments with Cu. Treating Ca as the solvent, a number of interaction coefficients such as \\varepsilon_{{{text{Al}}_{ 2} {text{O}}_{ 3} }}^{{{text{Al}}_{ 2} {text{O}}_{ 3} }} , \\varepsilon_{{{text{Al}}_{ 2} {text{O}}_{ 3} }}^{{{text{CaCl}}_{ 2} }} , \\varepsilon_{{{text{Al}}_{ 2} {text{O}}_{ 3} }}^{text{Sn}} , \\varepsilon_{{{text{CaCl}}_{ 2} }}^{{{text{CaCl}}_{ 2} }} , \\varepsilon_{{{text{CaCl}}_{ 2} }}^{text{Sn}} , and \\varepsilon_{text{Sn}}^{text{Sn}} as well as the activity coefficient ?_{{{text{Al}}_{ 2} {text{O}}_{ 3} }}0 were all determined at 1448 K. The activity of Ca (relative to pure liquid Ca) was obtained as approximately 0.65 to 0.75 in the system. Further, the two partial molar mixing/excess properties of alumina bar{H}_{{{text{Al}}_{ 2} {text{O}}_{ 3} }}M and bar{S}_{{{text{Al}}_{ 2} {text{O}}_{ 3} }}^{XS} in the alumina-saturated Ca-17 pct CaCl2- 37 pct Al2O3 (molar basis) slag were evaluated and found to be -118.3(±10.8) kJ/mol and -0.062(±0.007) kJ/K·mol, respectively, at 1448 to 1648 K. In addition, in view of the reported success of CaC2 as a refining agent, some experiments were carried out with CaC2-CaF2 mixtures in alumina, magnesia, and graphite crucibles at 1873 K, to remove tin from liquid Fe-2 wt pct Sn. However, alumina and magnesia crucibles leaked owing to their dissolution in calcium fluoride; in graphite crucibles, only a small transfer of tin, 3 to 7 pct of its initial mass, to the slag phase took place.

Ghosh, Dinabandhu

2009-08-01

296

Synthesis and Characterization of New Alkoxotitanates of Yttrium, Barium, and Copper: Single Crystal X-ray Diffraction Structures of Cl(2)Y{Ti(2)(OPr(i))(9)}, {Ti(OPr(i))(5)}Ba{Ti(2)(OPr(i))(9)}, and ClCu{Ti(2)(OPr(i))(9)}  

PubMed

The synthesis and characterization of new mixed-metal alkoxides of titanium with yttrium, barium, and copper, achieved via salt elimination and acid-base reactions, is described. The metathesis reactions of KTi(2)(OPr(i))(9) with anhydrous YCl(3) (1:1 and 2:1) and CuCl(2) (1:1) afford chloro-functionalized heterobimetallic alkoxides Cl(2)Y{Ti(2)(OPr(i))(9)} (1), ClY{Ti(2)(OPr(i))(9)}(2) (2), and ClCu{Ti(2)(OPr(i))(9)} (3), respectively, in high yields. The barium-titanium derivatives [Ba{Ti(2)(OPr(i))(10)}](2) (4), {Ti(2)(OPr(i))(9)}Ba{Ti(OPr(i))(5)} (5), and Ba{Ti(2)(OPr(i))(9)}(2) (6) result from the reaction between [Ba(OPr(i))(2)](n) and Ti(OPr(i))(4) in 1:2, 1:3, and 1:4 molar ratios, respectively. All the new derivatives (1-6) have been characterized by elemental analyses, variable-temperature (1)H and (13)C NMR, infrared spectroscopy, cryoscopy, and single crystal X-ray diffraction studies for 1, 3, and 5. The crystallographic study of 1 reveals a mononuclear species where the yttrium atom, coordinated by four alkoxide oxygen atoms of the {Ti(2)(OPr(i))(9)}(-) unit and two chloride ligands, is in a pseudo-octahedral arrangement. The NMR ((1)H and (13)C) and cryoscopic data for 1 indicate that the bioctahedral {Ti(2)(OPr(i))(9)} framework, as observed in the solid state structure, is retained in solution also. The X-ray structure of copper derivative 3 exhibits a triangular heterometallic core CuTi(2)(&mgr;(2)-OPr(i))(3)(&mgr;(3)-OPr(i))(2) with chloride as a terminal ligand on copper. Each titanium bears two terminal OPr(i) groups and displays a distorted octahedral geometry whereas copper has a pseudotrigonal bipyramidal environment. The high-temperature NMR studies for the paramagnetic 3 are in agreement with Curie law behavior; the isotropic shifts indicate that the OPr(i) groups bound directly to the Cu(II) center experience a greater paramagnetic influence in comparison to OPr(i) groups attached to titanium only. Barium titanates reveal an interesting observation of structural and stoichiometry (Ba/Ti) change. The dimeric compound 4 (Ba/Ti, 1:2) reacts with 1 mol of Ti(OPr(i))(4) to offer mononuclear 5 with a Ba/Ti stoichiometry of 1:3; on further addition of 1 mol of Ti(OPr(i))(4), 5 is converted to 6 (Ba/Ti, 1:4). X-ray crystallography performed on 5 shows the molecular structure to be formed by the coordination of monoanionic {Ti(OPr(i))(5)}(-) and {Ti(2)(OPr(i))(9)}(-) units to Ba(2+) in bi- and tetradentate fashion, respectively. The coordination figure of the central atom, barium, corresponds to a trigonal prism distorted toward an octahedron. Crystal data for 1: monoclinic space group Cc, a = 21.618(14) Å, b = 9.878(5) Å, c = 19.949(13) Å, beta = 109.51(4) degrees, V = 4015(4) Å(3), Z = 4. Crystal data for 3: triclinic space group P&onemacr;, a = 10.085(2) Å, b = 10.210(2) Å, c = 21.551(4) Å, alpha = 84.40(3) degrees, beta = 84.03(3) degrees, gamma = 60.86(3) degrees, V = 1924.9(6) Å(3), Z = 2. Crystal data for 5: triclinic space group P&onemacr;, a = 11.850(2)Å, b = 13.888(3) Å, c = 18.716(4) Å, alpha = 86.08(3) degrees, beta = 89.15(3) degrees, gamma = 83.36(3) degrees, V = 3052.3(11) Å(3), Z = 4. PMID:11669876

Veith, Michael; Mathur, Sanjay; Huch, Volker

1997-05-21

297

Effect of lead in water on the absorption of copper, iron, manganese and zinc by sheep (Ovis aries) infected with sheep tapeworm (Moniezia expansa).  

PubMed

The sheep tapeworm (Moniezia expansa) and its host Ovis aries were analyzed by inductively coupled plasma optical emission spectrometry (ICP-OES) for their copper, iron, manganese, zinc and lead levels. Element concentrations in cestode parasites were compared to those in various organs (liver, kidney, and muscle) of sheep. Tapeworms in the small intestine of sheep that were administered 2g of Pb(CH(3)COO)(2) per os daily (7 days) had significantly higher lead concentrations than sheep tissues. Cu levels significantly increased after Pb administration in sheep muscle and sheep tapeworms. Contrarily, Zn content significantly decreased in sheep muscle, but significantly increased in sheep tapeworms. However, Mn content significantly decreased after Pb administration in sheep tapeworms. Furthermore, Fe content significantly decreased after Pb administration in sheep liver and kidneys. PMID:22425750

Jankovská, I; Száková, J; Lukešová, D; Langrová, I; Válek, P; Vadlejch, J; ?adková, Z; Petrtýl, M

2012-03-08

298

[Preliminary study of the effect of supplementation of iron, copper, cobalt and zinc on cellulolytic activity in the cecum of the pony].  

PubMed

We studied a caecum-cannulated pony fed hay libitum in order to determine the mineral elements likely to cause deficiencies which decrease microbial activity in the caecum. During four successive 1-month periods, we observed the effects of adding 50 mg of iron, 1 mg of cobalt, 40 mg of copper and 200 mg of zinc, respectively. Except for the introduction of zinc, which greatly diminishes cellulolytic activity measured with the nylon bag technique, there was no significant modification in that activity as shown by pH, NH3-nitrogen, total nitrogen and volatile fatty acid production (table 1). It can be concluded that endogenous secretion in the pre-caecal part of the digestive system of the mineral elements used was sufficient to guarantee good symbiosis between the microbial population of the caecum and the organism. PMID:7349504

Tisserand, J L; Boulard, F; Deponge, P

1980-01-01

299

Deflocculants for Tape Casting Barium Titanate.  

National Technical Information Service (NTIS)

The dispersion properties of disperants with barium titanate were studied. Rheological, settling, volume and adsorption isotherms were obtained for barium titanate in MEK-ethanol using a phosphate ester dispersant. Effects of storage conditions, dispersan...

W. R. Cannon

1983-01-01

300

Barium hexaferrite (M-phase) exhibiting superstructure  

Microsoft Academic Search

Barium hexaferrite (M-phase) prepared by the flux method is found to exhibit a ..sqrt..3a x ..sqrt..3a superstructure similar to barium hexaaluminate. Morgan and Shaw as well as Iyi et al have recently reported the formation of a barium-rich phase of barium hexaaluminate possessing a ..sqrt..3a x ..sqrt..3a superstructure of the magnetoplumbite structure. In view of the similarities between the layer

L. Ganapathi; J. Gopalakrishnan; C. N. R. Rao

1984-01-01

301

Barium Stars and Thermohaline Mixing  

SciTech Connect

Barium stars are formed in binary systems through mass transfer from the carbon and s-element rich primary in the AGB phase, to the secondary star which is in a less evolved evolutionary stage. The mixing of the accreted material from the AGB donor with the envelope of the secondary results in a dilution of the s-element abundances. Dilution in red giants is explained by the occurence of the first dredge up, while in case of dwarfs thermohaline mixing would determine it. A comparison between the theoretical predictions of the AGB stellar models and the spectroscopical observations of a large sample of barium stars has been made. Dilution due to thermohaline mixing was taken into account when searching for best fits of the observational data. The importance of thermohaline mixing in barium dwarfs is discussed.

Husti, Laura [Dipartimento di Fisica Generale, Universita di Torino, Via Pietro Giuria 1, 10125 Turin (Italy)

2008-01-24

302

SOURCES OF COPPER AIR EMISSIONS  

EPA Science Inventory

The report gives results of a study to update estimates of atmospheric emissions of copper and copper compounds in the U.S. Source categories evaluated included: metallic minerals, primary copper smelters, iron and steel making, combustion, municipal incineration, secondary coppe...

303

Comparison of injectable iron complexes in their ability to iron load tissues and to induce oxidative stress  

Microsoft Academic Search

Iron and copper homeostasis have been studied in various tissues after iron-loading with the polynuclear ferric hydroxide carbohydrate complexes, iron dextran, iron polymaltose, iron sucrose and iron gluconate for four weeks. There were significant increases in the iron content of the different rat tissues compared to controls, with the exception of the brain, which showed no change in its iron

R. Legssyer; P. Geisser; Harry McArdle; R. R. Crichton; R. J. Ward

2003-01-01

304

Calcium, potassium, iron, copper and zinc concentrations in the white and gray matter of the cerebellum and corpus callosum in brain of four genetic mouse strains  

NASA Astrophysics Data System (ADS)

In the central nervous system, metallic cations are involved in oligodendrocyte maturation and myelinogenesis. Moreover, the metallic cations have been associated with pathogenesis, particularly multiple sclerosis and malignant gliomas. The brain is vulnerable to either a deficit or an excess of available trace elements. Relationship between trace metals and myelinogenesis is important in understanding a severe human pathology : the multiple sclerosis, which remains without efficient treatment. One approach to understand this disease has used mutant or transgenic mice presenting myelin deficiency or excess. But to date, the concentration of trace metals and mineral elements in white and gray matter areas in wild type brain is unknown. The aim of this study is to establish the reference concentrations of trace metals (iron, copper and zinc) and minerals (potassium and calcium) in the white and gray matter of the mouse cerebellum and corpus callosum. The brains of four different genetic mouse strains (C57Black6/SJL, C57Black6/D2, SJL and C3H) were analyzed. The freeze-dried samples were prepared to allow PIXE (Proton-induced X-ray emission) and RBS (Rutherford backscattering spectrometry) analyses with the nuclear microprobe in Bordeaux. The results obtained give the first reference values. Furthermore, one species out of the fours testes exhibited differences in calcium, iron and zinc concentrations in the white matter.

Sergeant, C.; Vesvres, M. H.; Devès, G.; Guillou, F.

2005-04-01

305

Zeus: Fast-spectrum critical assemblies with an iron-HEU core surrounded by a copper reflector  

SciTech Connect

Experiments to investigate critical systems of iron moderated highly enriched uranium in the intermediate-energy range were attempted. However, due to size limitations, the systems fell into the fast-energy range. Two critical configurations were established with a uranium mass of {approx} 198 kg and a Fe/{sup 235}U Ratio of {approx}15. Experimental uncertainties were systematically evaluated to estimate their effect on multiplication. The combined uncertainty for these experiments is estimated to be {+-}0.0024 {Delta}{sub eff}. Consequently, both Zeus iron configurations are judged to be acceptable for use as criticality-safety benchmark experiments. (authors)

Hayes, D. K.; Sanchez, R. G.; Kahler, A. C. [Los Alamos National Laboratory, PO Box 1663, Los Alamos, NM 87545 (United States)

2006-07-01

306

Effects of CaO, Al 2 O 3 , and MgO additions on the copper solubility, ferric\\/ferrous ratio, and minor-element behavior of iron-silicate slags  

Microsoft Academic Search

The effects of CaO, Al2O3, and MgO additions, singly or in combination, on the copper solubility, the Fe3+\\/Fe2+ ratio in slag, and on the minor-element behavior of silica-saturated iron silicate slags were examined at 1250 °C and a p\\u000a O2 of 10?12 to 10?6 atm. The results indicated that copper solubility in slag was lowered with the addition of CaO,

Hang Goo Kim; H. Y. Sohn

1998-01-01

307

Computer modelling of barium titanate  

Microsoft Academic Search

Barium titanate is an important material for both scientific and industrial applications. Much of the interest centres around its ferroelectric properties, since it is structurally the most simple in this class. In addition rare-earth doped ceramics are found to exhibit a very steep positive temperature coefficient of resistance (PTCR) above the Curie point. The theory of this PTCR effect is

G. V. Lewis; C. R. A. Catlow

1983-01-01

308

The Vapor Pressure of Barium.  

National Technical Information Service (NTIS)

The vapor pressure and the heat of vaporization of barium were measured using the Knudsen target technique. A recording microbalance was used to measure both the effusion rate and the recoil force exerted by the beam onto the target. The measured vapor pr...

P. D. Zavitsanos

1968-01-01

309

Solid Sliding Friction and Wear of Iron, Cobalt, Copper, Silver, Magnesium and Aluminum in an Oxygen-Nitrogen Mixture Between 760 Torr and 0.2 Microtorr . Festk Oerpergleitreibung und Verschleiss Voneisen, Kobalt, Kupfer, Silber, Magnesium und Aluminium in Einem Sauerstoff-Stickstoffgemisch Zwischen 760 Torr und 0.2 Microtorr.  

National Technical Information Service (NTIS)

Wear tests were carried out on iron, cobalt, copper, silver, magnesium, and aluminum, in an evacuable test chamber, in order to determine how far friction and wear depend on the crystal structures of the metallic friction partners, their reciprocal solubi...

K. Habig K. Kirschke W. Maennig H. Tischer

1972-01-01

310

Evidence for a copper-dependent iron transport system in the marine, magnetotactic bacterium strain MV1  

Microsoft Academic Search

Cells of the magnetotactic marine vibrio, strain MV-1, produce magnetite-containing magnetosomes when grown anaerobically or microaerobically. Stable, spontaneous, non-magnetotactic mutants were regularly observed when cells of MV-1 were cultured on solid media incubated under anaerobic or microaerobic conditions. Randomly amplified polymorphic DNA analysis showed that these mutants are not all genetically identical. Cellular iron content of one non-magnetotactic mutant strain,

Bradley L. Dubbels; Alan A. DiSpirito; John D. Morton; Jeremy D. Semrau; J. N. E. Neto; Dennis A. Bazylinski

2004-01-01

311

Iron, manganese and copper concentrations in wet precipitations and kinetics of the oxidation of SO 2 in rain water at two urban sites, Jaipur and Kota, in Western India  

Microsoft Academic Search

Rain-water samples were collected from Jaipur and Kota in Western India during the monsoon seasons of 1996–1999. In all cases, the pH of rain-water samples exceeded 7.0 and fell in the range (7.1–8.5). In view of the fact that the trace metals particularly iron, manganese and copper have been held responsible for the catalytic activity of rain-water, the chemical analysis

S. V Manoj; C. D Mishra; M Sharma; A Rani; R Jain; S. P Bansal; K. S Gupta

2000-01-01

312

Incoherent scattering functions of iron, copper, zirconium, tin, tantalum, tungsten, gold and lead, in the momentum range 2 Å-1 ? q ? 46 Å-1 at 661.6 keV photon energy  

NASA Astrophysics Data System (ADS)

The incoherent scattering functions were calculated from the measured differential incoherent scattering cross sections for 661.6 keV photons with a hyper pure germanium detector in the angular range of 5 120° covering the momentum range 2 Å-1 ? q ? 46 Å-1 for iron, copper, zirconium, tin, tantalum, tungsten, gold and lead. The measured incoherent scattering functions were compared with the NRHF values, recent DHFR values and other measured values.

Krishnaveni, S.; Gowda, Ramakrishna

2005-04-01

313

Measurement of fast-neutron activation cross sections for copper, europium, hafnium, iron, nickel, silver, terbium and titanium at 10.0 and 14.7 MeV and for the Be( d, n) thick-target spectrum  

Microsoft Academic Search

Several fast-neutron activation reactions for copper, europium, hafnium, iron, nickel, silver, terbium and titanium that are important to fusion energy have been investigated in three distinct neutron fields generated by accelerators at Argonne National Laboratory (ANL) and Los Alamos National Laboratory (LANL), U.S.A., and Japan Atomic Energy Research Institute (JAERI), Tokai, Japan. The experimental data acquired from this collaboration, which

J. W. Meadows; D. L. Smith; L. R. Greenwood; R. C. Haight; Y. Ikeda; C. Konno

1996-01-01

314

A validation of copper, nickel and iron data in endf\\/b-vi.2, jef-2.2 and jendl-3.2 through a series of br-1 critical core analysis  

Microsoft Academic Search

This report discusses the lessons learned from a validation of copper, nickel and iron data in ENDF\\/B-VI.2, JEF-2.2 and JENDL-3.2 through an analysis of 97.6 at. % 239PU metal fueled BR-1 fast reactor benchmarks. The specifications for the benchmarks in this study were taken from the ICSBEP handbook. The Monte Carlo code MCNP4B and continuous-energy cross-section libraries processed from the

Won-Guk Hwang; J KIM; S OH

1998-01-01

315

Precipitation and Characterization of Arsenate Phases from Calcium-Copper-Iron-Arsenic Oxide-Sulfate Hydrothermal Systems  

NASA Astrophysics Data System (ADS)

The scope of this thesis is the study of three Fe(III)-As(V) hydrothermal systems. The first one is the Fe(III)-AsO4-SO 4 system and crystalline phases that are produced under high temperature (150-225°C); this was studied to clear up previous contradicting information on this system in relation to industrial arsenic products that are formed during the autoclave processing of arsenical sulphide gold feedstocks and asses their arsenic stability. The second system studied was Cu(II)-Fe(III)-AsO 4-SO4 system at 150°C; this was investigated due to its relevance to industrial pressure leaching of copper concentrates. This system was studied in order to examine the possible effect of copper on the precipitation of scorodite. Finally, the structural and molecular examination of two members of the Ca(II)-Fe(III)-AsO4 system, namely yukonite (synthetic and natural and arseniosiderite was undertaken due to their relatively unknown nature and the potential role play in controlling arsenic release in tailings.

Gomez, Mario Alberto

316

DISTRIBUTION OF NATURAL AND ADDED COPPER AND 1RON IN MILK 1  

Microsoft Academic Search

SUMMARY A radioactive tracer was used to determine the distribution of copper in milk. For comparison, the distribution of radioactive iron also was determined. The method can readily distinguish the sources (natural or added) of copper or iron. Marked differences were observed in the distribution of natural and added copper. Naturally occurring copper was concentrated (ca. 10-35% of the copper)

R. L. KING; J. R. LUICK; I. I. LITMAN; W. G. JENNINGS; W. L. DUNKLEY

1958-01-01

317

Bacteremia during barium enema study.  

PubMed

The occurrence of bacteremia was studied in patients undergoing barium enema. Blood cultures were done on 34 patients before, during, and after the procedure using two schedules. Cultures were obtained once during the procedure in the first schedule and four times in the second. None of the cultures were positive by the first schedule, while 23% of patients studied by the second schedule had one or more positive cultures. Organisms isolated were anaerobes. The bacteremia was transient and self-limited, without serious clinical sequelae. The incidence of bacteremia during barium enema examination was statistically indistinguishable from bacteremia previously reported during colonscopy. It is concluded that antibiotic prophylaxis is not indicated in most patients undergoing colonic diagnostic procedures. Prophylaxis in selected high-risk patients requires further study. PMID:416682

Butt, J; Hentges, D; Pelican, G; Henstorf, H; Haag, T; Rolfe, R; Hutcheson, D

1978-04-01

318

Yttrium and barium in open clusters  

NASA Astrophysics Data System (ADS)

Based on the VLT high-resolution spectra for stars of five open clusters: Ruprecht 4, Ruprecht 7, Berkeley 25, Berkeley 73, and Berkeley 75 (G. Carraro et al., 2007) we determined the yttrium and barium abundances using the synthetic-spectrum method. Barium abundance was calculated under a non-LTE approximation. We analyzed the correlation between yttrium and barium abundances and the ages of open clusters and stars of the Galactic thin disk.

Mishenina, T. V.; Korotin, S. A.; Yegorova, I. A.; Kovtukh, V. V.; Carraro, G.

2013-06-01

319

Synthesis and characterization of new alkoxotitanates of yttrium, barium and copper: Single crystal X-ray diffraction structures of Cl{sub 2}Y(Ti{sub 2}(OPr{sup i}){sub 9}), (Ti(OPr{sup i}){sub 5})Ba(Ti{sub 2}(OPr{sup i}){sub 9}), and ClCu(Ti{sub 2}(OPr{sup i}){sub 9})  

SciTech Connect

The synthesis and characterization of new mixed-metal alkoxides of titanium with yttrium, barium, and copper, achieved via salt elimination and acid-base reactions, is described. The metathesis reactions of KTi{sub 2}(OPr{sup i}){sub 9} with anhydrous YCl{sub 3} (1:1 and 2:1) and CuCl{sub 2} (1:1) afford chloro-functionalized heterobimetallic alkoxides Cl{sub 2}Y(Ti{sub 2}(OPr{sup i}){sub 9}) (1), ClY(Ti{sub 2}(OPr{sup i}){sub 9}){sub 2} (2), and ClCu(Ti{sub 2}(OPr{sup i}){sub 9}) (3), respectively, in high yields. The barium - titanium derivatives [Ba(Ti{sub 2}(OPr{sup i}){sub 10})]{sub 2} (4), (Ti{sub 2}(OPr{sup i}){sub 9})Ba(Ti(OPr{sup i}){sub 5}) (5), and Ba(Ti{sub 2}(OPr{sup i}){sub 9}){sub 2} (6) result from the reaction between [Ba(OPr{sup i}){sub 2}]{sub n} and Ti(OPr{sup i}){sub 4} in 1:2, 1:3, and 1:4 molar ratios, respectively. All the new derivatives (1-6) have been characterized by elemental analyses, variable-temperature {sup 1}H and {sup 13}C NMR, infrared spectroscopy, cryoscopy, and single crystal X-ray diffraction studies for 1, 3, and 5. The crystallographic study of 1 reveals a mononuclear species where the yttrium atom, coordinated by four alkoxide oxygen atoms of the (Ti{sub 2}(OPr{sup i}){sub 9}){sup -} unit and two chloride ligands, is in a pseudo-octahedral arrangement. The NMR ({sup 1}H and {sup 13}C) and cryoscopic data for 1 indicate that the bioctahedral (Ti{sub 2}(OPr{sup i}){sub 9}) framework, as observed in the solid state structure, is retained in solution also. The X-ray structure of copper derivative 3 exhibits a triangular heterometallic core CuTi{sub 2}({mu}{sub 2}-OPr{sup i}){sub 3}({mu}{sub 3}-OPr{sup i}){sub 2} with chloride as a terminal ligand on copper. 46 refs., 3 figs., 4 tabs.

Veith, M.; Mathur, S.; Huch, V. [Univ. of Saarland, Saarbruecken (Germany)

1997-05-21

320

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Barium calcium manganese strontium oxide. ...Chemical Substances § 721.10011 Barium calcium manganese strontium oxide. ...The chemical substance identified as barium calcium manganese strontium...

2010-07-01

321

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Barium calcium manganese strontium oxide. ...Chemical Substances § 721.10011 Barium calcium manganese strontium oxide. ...The chemical substance identified as barium calcium manganese strontium...

2009-07-01

322

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Barium calcium manganese strontium oxide. 721.10011...Chemical Substances § 721.10011 Barium calcium manganese strontium oxide. (a...chemical substance identified as barium calcium manganese strontium oxide (PMN...

2013-07-01

323

Improved extraction method for the determination of iron, copper, and nickel in new varieties of sunflower oil by atomic absorption spectroscopy.  

PubMed

A simple and fast procedure is proposed for the extraction of iron (Fe), copper (Cu), and nickel (Ni) in 16 varieties of sunflower seed oil samples using an ultrasonic bath. The experimental parameters of the ultrasonic-assisted extraction (UAE) method were optimized to improve the sensitivity and detect the metals at trace levels in minimum time. Conventional wet acid digestion method was used for comparative purposes. The optimum recovery of all 3 metals was obtained by UAE for 7 min, while the separation of aqueous and organic phases after extraction using centrifugation (UAE-2) required 3 min, as compared to the conventional equilibration method (UAE-1) that required 90 min. The respective recoveries of Cu, Fe, and Ni obtained with UAE-2 were in the range of 95.8-97.5, 93.5-98.3, and 95.6-98.2%, respectively, for different varieties of sunflower oil samples. Accuracy was determined by the standard addition method. Under the optimum operating conditions, the limits of detection obtained from the standard addition curves were 21.7, 20.4, and 35.6 ng/mL for Fe, Cu, and Ni, respectively. The fact that all varieties of sunflower oil contain significant amounts of Fe, Cu, and Ni indicates the deterioration of sunflower oil quality immediately after extraction from seeds, which poses a threat to oil quality and human health. PMID:18476355

Ansari, Rehana; Kazi, Tasneem G; Jamali, Mohammad K; Arain, Mohammad B; Sherazi, Syed T; Jalbani, Nusrat; Afridi, Hassan I

324

Biosorption of copper(II), lead(II), iron(III) and cobalt(II) on Bacillus sphaericus-loaded Diaion SP-850 resin.  

PubMed

The biosorption of copper(II), lead(II), iron(III) and cobalt(II) on Bacillus sphaericus-loaded Diaion SP-850 resin for preconcentration-separation of them have been investigated. The sorbed analytes on biosorbent were eluted by using 1 mol L(-1) HCl and analytes were determined by flame atomic absorption spectrometry. The influences of analytical parameters including amounts of pH, B. sphaericus, sample volume etc. on the quantitative recoveries of analytes were investigated. The effects of alkaline, earth alkaline ions and some metal ions on the retentions of the analytes on the biosorbent were also examined. Separation and preconcentration of Cu, Pb, Fe and Co ions from real samples was achieved quantitatively. The detection limits by 3 sigma for analyte ions were in the range of 0.20-0.75 microg L(-1) for aqueous samples and in the range of 2.5-9.4 ng g(-1) for solid samples. The validation of the procedure was performed by the analysis of the certified standard reference materials (NRCC-SLRS 4 Riverine Water, SRM 2711 Montana soil and GBW 07605 Tea). The presented method was applied to the determination of analyte ions in green tea, black tea, cultivated mushroom, boiled wheat, rice and soil samples with successfully results. PMID:17386450

Tuzen, Mustafa; Uluozlu, Ozgur Dogan; Usta, Canan; Soylak, Mustafa

2006-08-26

325

Biofortification of crops with seven mineral elements often lacking in human diets--iron, zinc, copper, calcium, magnesium, selenium and iodine.  

PubMed

The diets of over two-thirds of the world's population lack one or more essential mineral elements. This can be remedied through dietary diversification, mineral supplementation, food fortification, or increasing the concentrations and/or bioavailability of mineral elements in produce (biofortification). This article reviews aspects of soil science, plant physiology and genetics underpinning crop biofortification strategies, as well as agronomic and genetic approaches currently taken to biofortify food crops with the mineral elements most commonly lacking in human diets: iron (Fe), zinc (Zn), copper (Cu), calcium (Ca), magnesium (Mg), iodine (I) and selenium (Se). Two complementary approaches have been successfully adopted to increase the concentrations of bioavailable mineral elements in food crops. First, agronomic approaches optimizing the application of mineral fertilizers and/or improving the solubilization and mobilization of mineral elements in the soil have been implemented. Secondly, crops have been developed with: increased abilities to acquire mineral elements and accumulate them in edible tissues; increased concentrations of 'promoter' substances, such as ascorbate, beta-carotene and cysteine-rich polypeptides which stimulate the absorption of essential mineral elements by the gut; and reduced concentrations of 'antinutrients', such as oxalate, polyphenolics or phytate, which interfere with their absorption. These approaches are addressing mineral malnutrition in humans globally. PMID:19192191

White, Philip J; Broadley, Martin R

2009-01-13

326

75 FR 20625 - Barium Chloride From China  

Federal Register 2010, 2011, 2012, 2013

...INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-149 (Third Review)] Barium Chloride From China AGENCY: United States International Trade Commission. ACTION: Revised schedule for the subject...

2010-04-20

327

A Possible Mechanism of Iron Neurotoxicity  

Microsoft Academic Search

Iron-dependent microsomal lipid peroxidation and catechol-iron (copper-induced lipid peroxidation have been studied to prove possible nigrostriatal cell damage. Iron-dependent microsomal lipid peroxidation could be initiated by reduced irons coordinated with phosphate moieties in the membranes and significantly inhibited by copper salicylate (hydrophobic and permeable O2-scavenger) and desferrioxamine (a powerful iron-chelating agent), but not by SOD. Ferric or cupric ion significantly

Minora Nakano

1993-01-01

328

Hydrogen bonding of sulfur ligands in blue copper and iron-sulfur proteins: detection by resonance raman spectroscopy  

SciTech Connect

The resonance Raman spectrum of the blue copper protein azurin from Alcaligenes denitrificans exhibits nine vibrational modes between 330 and 460 cm/sup -1/, seven of which shift 0.4-3.0 cm/sup -1/ to lower energy after incubation of the protein in D/sub 2/O. These deuterium-dependent shifts have been previously ascribed to exchangeable protons on imidazole ligands or to exchangeable protons on amide groups which are hydrogen bonded to the cysteine thiolate ligands (a feature common to all blue copper proteins of known structure). In order to distinguish between these two possibilities, a systematic investigation of Fe/sub 2/S/sub 2/(Cys)/sub 4/-containing proteins was undertaken. Extensive hydrogen bonding between sulfur ligands and the polypeptide backbone had been observed in the crystal structure of ferredoxin from Spirulina platensis. The resonance Raman spectrum of this protein is typical of a chloroplast-type ferredoxin and exhibits deuterium-dependent shifts of -0.3 to -0.5 cm/sup -1/ in the Fe-S modes at 283, 367, and 394 cm/sup -1/ and -0.6 to -0.8 cm/sup -1/ in the Fe-S modes at 328 and 341 cm/sup -1/. Considerably greater deuterium sensitivity is observed in the Raman spectra of spinach ferredoxin and bovine adrenodoxin, particularly for the symmetric stretching vibration of the Fe/sub 2/S/sub 2/ moiety at approx. 390 cm/sup -1/. This feature decreases of 9.8 and 1.1 cm/sup -1/, respectively, for the two oxidized proteins in D/sub 2/O and by 1.8 cm/sup -1/ for reduced adrenodoxin in D/sub 2/O. These results suggest that the bridging sulfido groups may be more extensively hydrogen bonded in spinach ferredoxin and adrenodoxin than in S. platensis ferredoxin, with a further increase in hydrogen-bond strength in the reduced form of adrenodoxin.

Mino, Y.; Loehr, T.M.; Wada, K.; Matsubara, H.; Sanders-Loehr, J.

1987-12-15

329

Modeling and minimization of barium sulfate scale  

Treesearch

Barium carbonate dissolves in the bleach plant when the pH drops below 7 and, if barium and ... at higher pH, but this will work only in mills where calcium scales are not a concern. A third option is to use crystal modifiers (scale inhibitors).

330

Opacity of iron, nickel, and copper plasmas in the x-ray wavelength range: Theoretical interpretation of 2p-3d absorption spectra  

SciTech Connect

This paper deals with theoretical studies on the 2p-3d absorption in iron, nickel, and copper plasmas related to LULI2000 (Laboratoire pour l'Utilisation des Lasers Intenses, 2000J facility) measurements in which target temperatures were of the order of 20 eV and plasma densities were in the range 0.004-0.01 g/cm{sup 3}. The radiatively heated targets were close to local thermodynamic equilibrium (LTE). The structure of 2p-3d transitions has been studied with the help of the statistical superconfiguration opacity code sco and with the fine-structure atomic physics codes hullac and fac. A new mixed version of the sco code allowing one to treat part of the configurations by detailed calculation based on the Cowan's code rcg has been also used in these comparisons. Special attention was paid to comparisons between theory and experiment concerning the term features which cannot be reproduced by sco. The differences in the spin-orbit splitting and the statistical (thermal) broadening of the 2p-3d transitions have been investigated as a function of the atomic number Z. It appears that at the conditions of the experiment the role of the term and configuration broadening was different in the three analyzed elements, this broadening being sensitive to the atomic number. Some effects of the temperature gradients and possible non-LTE effects have been studied with the help of the radiative-collisional code scric. The sensitivity of the 2p-3d structures with respect to temperature and density in medium-Z plasmas may be helpful for diagnostics of LTE plasmas especially in future experiments on the {Delta}n=0 absorption in medium-Z plasmas for astrophysical applications.

Blenski, T.; Loisel, G.; Poirier, M.; Thais, F.; Arnault, P.; Caillaud, T.; Fariaut, J.; Gilleron, F.; Pain, J.-C.; Porcherot, Q.; Reverdin, C.; Silvert, V.; Villette, B.; Bastiani-Ceccotti, S.; Turck-Chieze, S.; Foelsner, W.; Gaufridy de Dortan, F. de [CEA, IRAMIS, Service 'Photons, Atomes et Molecules', Centre d'Etudes de Saclay, F-91191 Gif-sur-Yvette Cedex (France); CEA, DAM, DIF, F-91297 Arpajon (France); LULI, UMR No. 7605 CNRS - Ecole Polytechnique, F-91128 Palaiseau Cedex (France); CEA, IRFU, Service d'Astrophysique, Centre d'Etudes de Saclay, F-91191 Gif-sur-Yvette Cedex (France); Max-Planck-Institut fuer Quantenoptik, D-85748 Garching (Germany); Institute of Nuclear Fusion, Universidad Politecnica de Madrid, Spain and Laboratoire d'Optique Appliquee, ENSTA-Paritech-Polytechnique, Chemin de la Huniere, F-91671 Palaiseau (France)

2011-09-15

331

One-dimensional strain initiated by rapid compaction of a heterogenous granular mixture consisting of copper, iron, silicon dioxide, carbon, molybdenum disulfide, and tin  

NASA Astrophysics Data System (ADS)

The dynamic compaction of metal powders is of great interest to the metallurgical and military communities. The compaction of a heterogeneous granular mixture consisting of copper, iron, silica, graphite, molybdenum-disulfide, and tin predominately used in aviation break-pad creation is presented. The initial density of the material was on average 2.756 gcm3 . The research also required developing a working projectile velocity measurement system and a proper target assembly for pressure measurements. Manganin gages were used to record the shock wave transit time and the pressure of the transmitted waveform into the powder mixture. An impedance matching technique was utilized to determine the particle velocity at the powder-impact plate interface and the shock velocity was determined from the measured data. The shock velocity and particle velocity were plotted to develop a linear equation of state, Us = SUp + C0. The linear equation of state was determined to have a Hugoniot slope of S = 0.3949 +/- 1.2869 and a bulk sound speed of C0 = 0.552 +/- .188( m/s). The equation of state was then employed in bulk one-dimensional computer simulations to compare to the waveform obtained from the pressure measurement system. The post-impact samples were investigated using a scanning electron microscope and electron dispersive spectroscopy to compare the microstructure of the dynamically compacted samples to the commercially manufactured pressed and sintered sample. The bulk scale simulations proved to recreate the pressure waveform from the pressure measurement system. It was also found that the dynamically compressed samples had minimal evidence of sintered grains, but had significant lateral fractures resulting from release.

Braun, Cullen A.

332

Levels of lead, cadmium, copper, iron, and zinc in deciduous teeth of children living in Irbid, Jordan by ICP-OES: some factors affecting their concentrations.  

PubMed

The aim of this study was to measure the concentrations of lead (Pb), cadmium (Cd), copper (Cu), iron (Fe), and zinc (Zn) in deciduous teeth from children living in Jordan and to investigate the affecting factors. Deciduous teeth samples (n = 320, without fillings) were collected from 5- to 12-year-old children and analyzed for Pb, Cd, Cu, Fe, and Zn using inductively coupled plasma-optical emission spectrometry. A questionnaire was used to gather information on each child, such as sex, age, tooth type (incisors, canines, and molars), tooth position within the mouth (upper or lower jaw), caries status, presence of amalgam fillings inside the mouth, type of drinking water (tap water, home purified water, and plant purified water), and zone of residence (close to or far from heavy traffic roads). The mean concentrations of Pb, Cd, Cu, Fe, and Zn were 30.26, 0.55, 6.23, 34.72, and 128.21 ?g/g, respectively. Our results indicate that there is a clear relation between the concentrations of the metals analyzed in this study and tooth type, tooth position within the mouth, caries status, presence of amalgam fillings inside the mouth, and type of drinking water. No significant differences in the concentrations of the five metals analyzed were observed due to sex. Our results also show that no significant difference among Pb, Cd, Cu, Fe, and Zn concentrations and age among the ages of 5-6, 7-8, 9-10, and 11-12, except for Pb, which decreases at age 11-12. PMID:22851195

Alomary, A; Al-Momani, I F; Obeidat, S M; Massadeh, A M

2012-08-01

333

Lead, mercury, cadmium, chromium, nickel, copper, zinc, calcium, iron, manganese and chromium (VI) levels in Nigeria and United States of America cement dust.  

PubMed

This study was aimed at investigating the relative abundance of heavy metals in cement dust from different cement dust factories in order to predict their possible roles in the severity of cement dust toxicity. The concentrations of total mercury (Hg), copper (Cu), chromium (Cr), cadmium (Cd), nickel (Ni), manganese (Mn), lead (Pb), iron (Fe) and chromium (VI) (Cr (VI)) levels in cement dust and clinker samples from Nigeria and cement dust sample from the United States of America (USA) were determined using graphite furnace atomic absorption (GFAAS), while Zn and Ca were measured by flame atomic absorption spectrophotometry (FAAS), and Cr (VI) by colorimetric method. Total Cu, Ni and Mn were significantly higher in cement dust sample from USA (p<0.05), also, both total Cr and Cr (VI) were 5.4-26 folds higher in USA cement dust compared with Nigeria cement dust or clinker (p<0.001). Total Cd was higher in both Nigeria cement dust and clinker (p<0.05 and p<0.001), respectively. Mercury was more in both Nigeria cement dust and clinker (p<0.05), while Pb was only significantly higher in clinker from Nigeria (p<0.001). These results show that cement dust contain mixture of metals that are known human carcinogens and also have been implicated in other debilitating health conditions. Additionally, it revealed that metal content concentrations are factory dependent. This study appears to indicate the need for additional human studies relating the toxicity of these metals and their health impacts on cement factory workers. PMID:23261125

Ogunbileje, J O; Sadagoparamanujam, V-M; Anetor, J I; Farombi, E O; Akinosun, O M; Okorodudu, A O

2012-12-21

334

Oxidation resistant copper  

NASA Astrophysics Data System (ADS)

Oxidation resistant particles composed of copper and at least one metal having a valence of +2 or +3 and having an intermediate lattice energy for the metal in its hydroxide form are presented. The metal is selected from nickel, cobalt, iron, manganese, cadmium, zinc, tin, magnesium, calcium and chromium. In one embodiment, the phases of copper and at least one metal in the particles are separate and the concentration of the metal is greater near the surface of the particles than inwardly thereof. Process for making the oxidation resistant copper particles includes the steps of dissolving a copper salt and a salt of at least one of the metals in a suitable solvent or diluent; forming primary particles of copper and at least one metal in basic form by mixing a base and the salt solution; separating, washing and drying the primary particles; reducing the primary particles to metallic form; and heat treating the particles in metallic form at an elevated temperature.

Edelstein, Alan S.; Kaatz, Forrest H.; Harris, Vincent G.

1993-11-01

335

Syntheses, Spectral, Thermal and Electrochemical Studies of 3-Carboxylacetonehydroxamic Acid and its Iron(Ii), Cobalt(Ii), Nickel(Ii), Copper(Ii) and Zinc(Ii) Complexes  

Microsoft Academic Search

3-Carboxylacetonehydroxamic acid (CAHA) and its iron(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes were synthesized and characterized by elemental analysis, UV-Vis and IR spectra and magnetic susceptibility. The pKa1 and pKa2 values of the ligand in aqueous solution were found to be 6.5 ± 0.1 and 8.6 ± 0.1, which correspond to dissociation of carboxyl and hydroxamic protons, respectively. The dianion

Fatih Yilmaz; Veysel T. Yilmaz; Saim Topcu; Necati Menek

2003-01-01

336

New barium ferrite particles: Spherical shape  

NASA Astrophysics Data System (ADS)

Pure and ZnTi-doped spherical barium ferrite particles were prepared using two different methods: semicoprecipitation and ultrasonic spray pyrolysis. The ultrasonic spray pyrolysis method was more effective in controlling particle shape. Particle size was in between 0.27 and 0.3 ?m. Coercivity and saturation magnetization were in the range of 1000 to 5000 Oe and 49 to 53 emu/g, respectively. Crystallization of amorphous Ba-Fe-O spherical precursors occurs at a lower temperature than Ba-Fe-Zn-Ti-O precursors. ?M measurement shows that magnetic interaction in spherical barium ferrite tape is weaker than hexagonal platelet barium ferrite.

Hong, Y. K.; Jung, H. S.

1999-04-01

337

Method for harvesting rare earth barium copper oxide single crystals  

DOEpatents

A method of preparing high temperature superconductor single crystals is disclosed. The method of preparation involves preparing precursor materials of a particular composition, heating the precursor material to achieve a peritectic mixture of peritectic liquid and crystals of the high temperature superconductor, cooling the peritectic mixture to quench directly the mixture on a porous, wettable inert substrate to wick off the peritectic liquid, leaving single crystals of the high temperature superconductor on the porous substrate. Alternatively, the peritectic mixture can be cooled to a solid mass and reheated on a porous, inert substrate to melt the matrix of peritectic fluid while leaving the crystals melted, allowing the wicking away of the peritectic liquid. 2 figs.

Todt, V.R.; Sengupta, S.; Shi, D.

1996-04-02

338

Method for harvesting rare earth barium copper oxide single crystals  

DOEpatents

A method of preparing high temperature superconductor single crystals. The method of preparation involves preparing precursor materials of a particular composition, heating the precursor material to achieve a peritectic mixture of peritectic liquid and crystals of the high temperature superconductor, cooling the peritectic mixture to quench directly the mixture on a porous, wettable inert substrate to wick off the peritectic liquid, leaving single crystals of the high temperature superconductor on the porous substrate. Alternatively, the peritectic mixture can be cooled to a solid mass and reheated on a porous, inert substrate to melt the matrix of peritectic fluid while leaving the crystals melted, allowing the wicking away of the peritectic liquid.

Todt, Volker R. (Lemont, IL); Sengupta, Suvankar (Columbus, OH); Shi, Donglu (Cincinnati, OH)

1996-01-01

339

Hydrogen production from water using copper and barium hydroxide  

DOEpatents

A process for producing hydrogen comprises the step of reacting metallic Cu with Ba(OH).sub.2 in the presence of steam to produce hydrogen and BaCu.sub.2 O.sub.2. The BaCu.sub.2 O.sub.2 is reacted with H.sub.2 O to form Cu.sub.2 O and a Ba(OH).sub.2 product for recycle to the initial reaction step. Cu can be obtained from the Cu.sub.2 O product by several methods. In one embodiment the Cu.sub.2 O is reacted with HF solution to provide CuF.sub.2 and Cu. The CuF.sub.2 is reacted with H.sub.2 O to provide CuO and HF. CuO is decomposed to Cu.sub.2 O and O.sub.2. The HF, Cu and Cu.sub.2 O are recycled. In another embodiment the Cu.sub.2 O is reacted with aqueous H.sub.2 SO.sub.4 solution to provide CuSO.sub.4 solution and Cu. The CuSO.sub.4 is decomposed to CuO and SO.sub.3. The CuO is decomposed to form Cu.sub.2 O and O.sub.2. The SO.sub.3 is dissolved to form H.sub.2 SO.sub.4. H.sub.2 SO.sub.4, Cu and Cu.sub.2 O are recycled. In another embodiment Cu.sub.2 O is decomposed electrolytically to Cu and O.sub.2. In another aspect of the invention, Cu is recovered from CuO by the steps of decomposing CuO to Cu.sub.2 O and O.sub.2, reacting the Cu.sub.2 O with aqueous HF solution to produce Cu and CuF.sub.2, reacting the CuF.sub.2 with H.sub.2 O to form CuO and HF, and recycling the CuO and HF to previous reaction steps.

Bamberger, Carlos E. (Oak Ridge, TN); Richardson, deceased, Donald M. (late of Oak Ridge, TN)

1979-01-01

340

The Intec Copper Process: A Detailed Environmental Analysis  

Microsoft Academic Search

The Intec Copper Process is an environmentally advantageous hydrometallurgical process for the production of high purity copper and associated precious metals from copper sulphide concentrates. The process uses a mixed chloride-bromide lixiviant in an elegant cyclic circuit to leach the copper into solution, rejecting the iron as stable hematite rather than as unstable jarosite. After purification of the pregnant liquor,

D Sammut; N J Welham

341

Removal of Barium and Radium from Groundwater.  

National Technical Information Service (NTIS)

A research project was undertaken to investigate processes for removing barium and radium from drinking water. Special emphasis was placed on ion exchange processes that can be used without adding large concentrations of sodium to the water. The wastes fr...

V. L. Snoeyink C. C. Chambers C. K. Schmidt R. F. Manner A. G. Myers

1987-01-01

342

Deflocculants for Tape Casting Barium Titanate Dielectrics.  

National Technical Information Service (NTIS)

The tape casting slip composition barium titanate powder, MEK-Ethanol solvent, phosphate ester dispersant, acrylic binder, PEG and butyl-benzyl-phthalate plasticizers and cyclohexanone was studied. The nature of the dispersion mechanism for the phosphate ...

W. R. Cannon

1985-01-01

343

Spatial and temporal zoning of hydrothermal alteration and mineralization in the Sossego iron oxide-copper-gold deposit, Carajás Mineral Province, Brazil: paragenesis and stable isotope constraints  

NASA Astrophysics Data System (ADS)

The Sossego iron oxide-copper-gold deposit (245 Mt @ 1.1% Cu, 0.28 g/t Au) in the Carajás Mineral Province of Brazil consists of two major groups of orebodies (Pista-Sequeirinho-Baiano and Sossego-Curral) with distinct alteration assemblages that are separated from each other by a major high angle fault. The deposit is located along a regional WNW-ESE-striking shear zone that defines the contact between metavolcano-sedimentary units of the ˜2.76 Ga Itacaiúnas Supergroup and tonalitic to trondhjemitic gneisses and migmatites of the ˜2.8 Ga Xingu Complex. The deposit is hosted by granite, granophyric granite, gabbro, and felsic metavolcanic rocks. The Pista-Sequeirinho-Baiano orebodies have undergone regional sodic (albite-hematite) alteration and later sodic-calcic (actinolite-rich) alteration associated with the formation of massive magnetite-(apatite) bodies. Both these alteration assemblages display ductile to ductile-brittle fabrics. They are cut by spatially restricted zones of potassic (biotite and potassium feldspar) alteration that grades outward to chlorite-rich assemblages. The Sossego-Curral orebodies contain weakly developed early albitic alteration and very poorly developed subsequent calcic-sodic alteration. These orebodies contain well-developed potassic alteration assemblages that were formed during brittle deformation that resulted in the formation of breccia bodies. Breccia matrix commonly displays coarse mineral infill suggestive of growth into open space. Sulfides in both groups of deposits were precipitated first with potassic alteration and more importantly with a later assemblage of calcite-quartz-epidote-chlorite. In the Sequeirinho orebodies, sulfides range from undeformed to deformed; sulfides in the Sossego-Curral orebodies are undeformed. Very late, weakly mineralized hydrolytic alteration is present in the Sossego/Currral orebodies. The sulfide assemblage is dominated by chalcopyrite with subsidiary siegenite, and millerite. Pyrrhotite and pyrite are minor constituents of ore in the Sequerinho orebodies while pyrite is relatively abundant in the Sossego-Curral bodies. Oxygen isotope partitioning between mineral pairs constrains temperatures in the deposit spatially and through time. In the Sequeirinho orebody, the early sodic-calcic alteration stage was characterized by temperatures exceeding 500°C and ? ^{{{text{18}}}} {text{O}}_{{{text{H}}_{{text{2}}} {text{O}}}} values for the alteration fluid of 6.9 ± 0.9‰. Temperature declines outward and upward from the zone of most intense alteration. Paragenetically later copper-gold mineralization displays markedly lower temperatures (<300°C) and was characterized by the introduction of 18O-depleted hydrothermal fluids -1.8 ± 3.4‰. The calculated ?DH2O and ? ^{{{text{18}}}} {text{O}}_{{{text{H}}_{{text{2}}} {text{O}}}} values suggest that the fluids that formed the early calcic-sodic alteration assemblage were of formational/metamorphic or magmatic origin. The decrease of ? ^{{{text{18}}}} {text{O}}_{{{text{H}}_{{text{2}}} {text{O}}}} values through time may reflect influx of surficially derived waters during later alteration and mineralization events. Influx of such fluids could be related to episodic fluid overpressure, resulting in dilution and cooling of the metalliferous fluid, causing deposition of metals transported as metal chloride complexes.

Monteiro, Lena V. S.; Xavier, Roberto P.; de Carvalho, Emerson R.; Hitzman, Murray W.; Johnson, Craig A.; de Souza Filho, Carlos Roberto; Torresi, Ignácio

2008-02-01

344

Analysis of the fuel wood used in Late Bronze Age and Early Iron Age copper mining sites of the Schwaz and Brixlegg area (Tyrol, Austria)  

Microsoft Academic Search

Charcoal analysis was carried out as part of an interdisciplinary project focusing on the copper mining history of the former mining area of Schwaz and Brixlegg, a region pivotal as a copper source in prehistoric Europe. The goal was to use remains of carbonised wood to investigate environmental implications of prehistoric mining, as well as to gain new insight about

Andreas G. Heiss; Klaus Oeggl

2008-01-01

345

Interactions of free copper (II) ions alone or in complex with iron (III) ions with erythrocytes of marine fish Dicentrarchus labrax  

Microsoft Academic Search

As a consequence of human activity, various toxicants – especially metal ions – enter aquatic ecosystems and many fish are exposed to considerable levels. As the free ion and in some complexes, there is no doubt that copper promotes damage to cellular molecules and structures through radical formation. Therefore, we have investigated the influence of copper uptake by the red

Magdalena Labieniec; Katarzyna Milowska; Aneta Balcerczyk; Agata Rucinska; Magdalena Sadowska; Marta Jokiel; Gerard Brichon; Teresa Gabryelak

2009-01-01

346

Dielectric and Piezoelectric Properties of Barium Titanate  

Microsoft Academic Search

The dielectric constant and loss of barium titanate and barium-strontium titanate have been measured at biasing field strengths from 0 to 5 megavolts per meter, at temperatures from -50°C to +135°C and at frequencies from 0.1 to 25 megacycles. The measurements versus temperature indicate the expected agreement with the Curie-Weiss law at temperatures above the Curie point. Measurements versus field

Shepard Roberts

1947-01-01

347

Small barium rail gun for plasma injection.  

PubMed

A small rail gun with a barium electrode can be operated at higher than one shot per second to produce more than 2x10(16) barium ions with energy 10-20 eV. The operation of the gun takes advantage of the external magnetic field for cross-field plasma injection into a trap. Up to 7 kG of the magnetic field examined, the gun performance improves with the increased magnetic field strength. PMID:18647050

Kiwamoto, Y

1980-03-01

348

Effect of dietary Garcinia cambogia extract on serum essential minerals (calcium, phosphorus, magnesium) and trace elements (iron, copper, zinc) in rats fed with high-lipid diet.  

PubMed

The aim of the study was to investigate the effect of Garcinia cambogia extract on serum calcium (Ca), phosphorus (P), magnesium (Mg), iron (Fe), zinc (Zn) and copper (Cu) concentrations in rats fed with the normal or the high-lipid and -cholesterol diet. Thirty 1-year-old female Sprague-Dawley rats (pathogen-free), weighing an average of 229 g, were randomly assigned to three experimental groups of ten animals each. Diets and tap water were given ad libitum for 75 days. Group 1 (control group) was fed with basal diet (2 % liquid vegetable oil, 0 % cholesterol), while the diets of groups 2 and 3 contained vegetable oil (2 % liquid vegetable oil and 5 % hydrogenated vegetable oil) and cholesterol (3 %) in high levels. 4,5 % G. cambogia extract containing 65 % HCA was added to the diet of group 3 as from day 45. Blood samples were withdrawn on days 0, 45 and 75. Serum mineral levels were analyzed using standard enzymatic colorimetric methods with a spectrophotometer. All significant differences were p<0.05. Serum Ca levels were not significantly different between all groups on days 45 and 75. Serum P level was significantly higher in the group fed with high-lipid diet and G. cambogia extract than in the control group on day 45. Serum Mg level was significantly higher in group 2 than in the control group on day 45. Serum Fe levels were significantly lower in the control group than in the other groups on days 45 and 75. Serum Zn level of the group fed with high-lipid diet and G. cambogia extract was significantly higher than in the control group on day 75. Serum Cu levels were significantly higher in group 2 than in the control group, and in group 3 than in group 2 on day 75. In conclusion, a diet containing the high fat amounts may lead to the increase in circular levels of some minerals due to the short-chain fatty acid production lowering the luminal pH which increases mineral solubility, or serving as a fuel for mucosal cells and stimulating cell proliferation in the large intestine. G. cambogia extract may be used in the P and Cu deficiencies due to increases resulting in the present P and Cu amounts in G. cambogia extract, or the use of phytate P in diet. It was hoped that with further evidence-based study this product will enter to mainstream medicines. PMID:22419377

Gürsel, Feraye Esen; Ate?, Atila; Bilal, Tanay; Altiner, Ay?en

2012-03-15

349

Carbon and oxygen isotope constraints on fluid sources and fluid-wallrock interaction in regional alteration and iron-oxide-copper-gold mineralisation, eastern Mt Isa Block, Australia  

NASA Astrophysics Data System (ADS)

The source of metasomatic fluids in iron-oxide-copper-gold districts is contentious with models for magmatic and other fluid sources having been proposed. For this study, ? 18O and ? 13C ratios were measured from carbonate mineral separates in the Proterozoic eastern Mt Isa Block of Northwest Queensland, Australia. Isotopic analyses are supported by petrography, mineral chemistry and cathodoluminescence imagery. Marine meta-carbonate rocks (ca. 20.5‰ ? 18O and 0.5‰ ? 13C calcite) and graphitic meta-sedimentary rocks (ca. 14‰ ? 18O and -18‰ ? 13C calcite) are the main supracrustal reservoirs of carbon and oxygen in the district. The isotopic ratios for calcite from the cores of Na-(Ca) alteration systems strongly cluster around 11‰ ? 18O and -7‰ ? 13C, with shifts towards higher ? 18O values and higher and lower ? 13C values, reflecting interaction with different hostrocks. Na-(Ca)-rich assemblages are out of isotopic equilibrium with their metamorphic hostrocks, and isotopic values are consistent with fluids derived from or equilibrated with igneous rocks. However, igneous rocks in the eastern Mt Isa Block contain negligible carbon and are incapable of buffering the ? 13C signatures of CO2-rich metasomatic fluids associated with Na-(Ca) alteration. In contrast, plutons in the eastern Mt Isa Block have been documented as having exsolved saline CO2-rich fluids and represent the most probable fluid source for Na-(Ca) alteration. Intrusion-proximal, skarn-like Cu-Au orebodies that lack significant K and Fe enrichment (e.g. Mt Elliott) display isotopic ratios that cluster around values of 11‰ ? 18O and -7‰ ? 13C (calcite), indicating an isotopically similar fluid source as for Na-(Ca) alteration and that significant fluid-wallrock interaction was not required in the genesis of these deposits. In contrast, K- and Fe-rich, intrusion-distal deposits (e.g. Ernest Henry) record significant shifts in ? 18O and ? 13C towards values characteristic of the broader hostrocks to the deposits, reflecting fluid-wallrock equilibration before mineralisation. Low temperature, low salinity, low ? 18O (<10‰ calcite) and CO2-poor fluids are documented in retrograde metasomatic assemblages, but these fluids are paragenetically late and have not contributed significantly to the mass budgets of Cu-Au mineralisation.

Marshall, Lucas J.; Oliver, Nicholas H. S.; Davidson, Garry J.

2006-08-01

350

The rise and phalli of barium stars  

NASA Astrophysics Data System (ADS)

Barium stars are thought to be formed by accretion of material from the wind of an s-process-rich asymptotic giant branch star onto a main sequence star in a binary system. The accretor then evolves up the giant branch and, as it cools, absorption lines of barium are prominent in its spectrum. This is the barium star we see today. Barium stars are excellent probes of binary-star physics because orbital periods and eccentricities are known for nearly all of them, i.e. the sample set is complete. Binary-star theory predicts that barium stars with periods shorter than a few thousand days should circularise by tidal interaction, but the observed stars are often highly eccentric. We investigate a potential source of their eccentricity: white dwarf kicks. We can reproduce the observed period-eccentricity distribution if we introduce a moderate kick speed of a few km/s together with efficient angular momentum loss in stellar winds and efficient common-envelope ejection. Many open questions remain which are key to the wind-accretion mechanism by which barium stars and other chemically-peculiar binaries such as CH and carbon-enhanced metal-poor (CEMP) stars form.

Izzard, R. G.; Dermine, T.; Church, R. P.

351

Extractive separation of copper and nickel from copper bleed stream by solvent extraction route  

Microsoft Academic Search

Bleed stream from electro refining step of copper smelter was processed to recover the metals as high value products such as copper and nickel powders or salts. The process consists of partial decopperisation of the bleed stream followed by crystallization of a mixed salt of copper and nickel sulphate, leaching of the mixed salt, removal of iron, solvent extraction for

Archana Agrawal; M. K. Manoj; S. Kumari; D. Bagchi; V. Kumar; B. D. Pandey

2008-01-01

352

Sulphate removal from sodium sulphate-rich brine and recovery of barium as a barium salt mixture.  

PubMed

Sulphate removal from sodium sulphate-rich brine using barium hydroxide and recovery of the barium salts has been investigated. The sodium sulphate-rich brine treated with different dosages of barium hydroxide to precipitate barium sulphate showed sulphate removal from 13.5 g/L to less than 400 mg/L over 60 min using a barium to sulphate molar ratio of 1.1. The thermal conversion of precipitated barium sulphate to barium sulphide achieved a conversion yield of 85% using coal as both a reducing agent and an energy source. The recovery of a pure mixture of barium salts from barium sulphide, which involved dissolution of barium sulphide and reaction with ammonium hydroxide resulted in recovery of a mixture of barium carbonate (62%) and barium hydroxide (38%), which is a critical input raw material for barium salts based acid mine drainage (AMD) desalination technologies. Under alkaline conditions of this barium salt mixture recovery process, ammonia gas is given off, while hydrogen sulfide is retained in solution as bisulfide species, and this provides basis for ammonium hydroxide separation and recovery for reuse, with hydrogen sulfide also recoverable for further industrial applications such as sulfur production by subsequent stripping. PMID:23485244

Vadapalli, Viswanath R K; Zvimba, John N; Mulopo, Jean; Motaung, Solly

2013-01-01

353

Copper Test  

MedlinePLUS

... 3. What happens if I am exposed to toxic amounts of copper? Copper poisoning can cause vomiting ... Asked Questions American Cancer Society: Copper Agency for Toxic Substances and Disease Registry: Public Health Statement for ...

354

Copper in microbial pathogenesis: meddling with the metal  

PubMed Central

Transition metals such as iron, zinc, copper and manganese are essential for the growth and development of organisms ranging from bacteria to mammals. Numerous studies have focused on the impact of iron availability during bacterial and fungal infections, and increasing evidence suggests that copper is also involved in microbial pathogenesis. Not only is copper an essential co-factor for specific microbial enzymes, but several recent studies also strongly suggest that copper is used to restrict pathogen growth in vivo. Here, we review evidence that animals use copper as an anti-microbial weapon and, in turn, microbes have developed mechanisms to counteract the toxic effects of copper.

Samanovic, Marie I.; Ding, Chen; Thiele, Dennis J.; Darwin, K. Heran

2012-01-01

355

Corrosion resistant gray cast iron graphite flake alloys  

Microsoft Academic Search

Corrosion resistant gray cast iron alloys useful in downhole oil well environments and the like. The alloys are substantially lower in cost and substantially higher in tensile strength than high nickel-copper cast irons commonly used downhole in submergible pumps. The alloys contain substantial amounts of aluminum in combination with nickel, chromium, manganese, molybdenum, carbon, silicon, and iron. Copper, tin, vanadium,

1985-01-01

356

Property and Microstructural Nonuniformity in the Yttrium-Barium Superconductor Determined from Electrical, Magnetic, and Ultrasonic Measurements  

Microsoft Academic Search

The purpose of this dissertation was to (1) characterize the effect of pore fraction on a comprehensive set of electrical and magnetic properties for the yttrium-barium-copper-oxide (YBCO) high temperature ceramic superconductor and (2) determine the viability of using a room-temperature, nondestructive characterization method to aid in the prediction of superconducting (cryogenic) properties. The latter involved correlating ultrasonic velocity measurements at

Don Jeremy Roth

1991-01-01

357

Hydrothermal alteration, fluid inclusions and stable isotope systematics of the Alvo 118 iron oxide-copper-gold deposit, Carajás Mineral Province (Brazil): Implications for ore genesis  

NASA Astrophysics Data System (ADS)

The Alvo 118 iron oxide-copper-gold (IOCG) deposit (170 Mt at 1.0 wt.% Cu, 0.3 g/t Au) lies in the southern sector of the Itacaúnas Shear Belt, Carajás Mineral Province, along a WNW-ESE-striking, 60-km-long shear zone, close to the contact of the ~2.76-Ga metavolcano-sedimentary Itacaiúnas Supergroup and the basement (~3.0 Ga Xingu Complex). The Alvo 118 deposit is hosted by mafic and felsic metavolcanic rocks and crosscutting granitoid and gabbro intrusions that have been subjected to the following hydrothermal alteration sequence towards the ore zones: (1) poorly developed sodic alteration (albite and scapolite); (2) potassic alteration (biotite or K-feldspar) accompanied by magnetite formation and silicification; (3) widespread, pervasive chlorite alteration spatially associated with quartz-carbonate-sulphide infill ore breccia and vein stockworks; and (4) local post-ore quartz-sericite alteration. The ore assemblage is dominated by chalcopyrite (~60%), bornite (~10%), hematite (~20%), magnetite (10%) and subordinate chalcocite, native gold, Au-Ag tellurides, galena, cassiterite, F-rich apatite, xenotime, monazite, britholite-(Y) and a gadolinite-group mineral. Fluid inclusion studies in quartz point to a fluid regime composed of two distinct fluid types that may have probably coexisted within the timeframe of the Cu-Au mineralizing episode: a hot (>200°C) saline (32.8‰ to 40.6 wt.% NaCl eq.) solution, represented by salt-bearing aqueous inclusions, and a lower temperature (<200°C), low to intermediate salinity (<15 wt.% NaCl eq.) aqueous fluid defined by two-phase (LH2O + VH2O) fluid inclusions. This trend is very similar to those defined for other IOCG systems of the Carajás Mineral Province. ? 18OH2O values in equilibrium with calcite (-1.0‰ to 7.5‰ at 277°C to 344°C) overlap the lower range for primary magmatic waters, but the more 18O-depleted values also point to the involvement of externally derived fluids, possibly of meteoric origin. Furthermore, sulphide ? 34S values (5.1‰ to 6.3‰), together with available boron isotope and Cl/Br-Na/Cl data provide evidence for a significant component of residual evaporative fluids (e.g., bittern fluids generated by seawater evaporation) in this scenario that, together with magma-derived brines, would be the main sources of the highly saline fluids involved in the formation Alvo 118 IOCG deposit. The restricted high temperature sodic alteration, the pervasive overprinting of the potassic alteration minerals by chlorite proximal to the ore zones, ore breccias with open-space filling textures in brittle structures, microthermometric and stable isotope data indicate, collectively, that the Alvo 118 IOCG system developed at structurally high levels and may be considered the shallower representative of the IOCG systems of the CMP.

Torresi, Ignacio; Xavier, Roberto Perez; Bortholoto, Diego F. A.; Monteiro, Lena V. S.

2012-03-01

358

Intramural extravasation of barium simulating carcinoma of the rectum  

Microsoft Academic Search

This report describes two patients found to have barium granuloma of the rectum. The lesions appeared as indurated, ulcerated\\u000a rectal masses that resembled carcinoma on endoscopic examination. Deep mucosal biopsy results demonstrated no malignancy and\\u000a barium sulfate crystals in tissue macrophages. Radiographs showed persistent soft-tissue barium in the rectum. Past reports\\u000a of barium granuloma have described ulcerated or polypoid masses

John E. Phelps; Robert A. Sanowski; Richard A. Kozarek

1981-01-01

359

Improved spectrophotometric analysis of barium styphnate  

SciTech Connect

A spectrophotometric procedure to determine the purity of barium styphnate monohydrate based upon the absorbance of the styphnate ion at 326 and 413.3 nm has been developed. The purity is determined by comparing the absorbance of the styphnate ion in barium styphnate and in styphnic acid. Our investigation has shown that the molar absorptivity and lambda maxima of the styphnate ion are quite pH dependent; therefore, the pH is buffered to 6.8 to 7.0 with ammonium acetate. Under these conditions the molar absorptivity is 1.6 x 10/sup 4/ L/mol-cm. Analyses following the procedure in the Navy specification WS13444A using water were found to give low molar absorptivities (1.3 x 10/sup 4/ L/mol-cm) for the styphnic acid calibration resulting in erroneous values for barium styphnate purity.

Brown, N E; Blasi, J A

1983-01-01

360

The Effects of Iron and Thorium Ions on the Kinetics of Precipitation of BaSO4.  

National Technical Information Service (NTIS)

The Coulter Counter has been used to record in situ growth and aging curves for the precipitation of barium sulfate. Teflon was found to catalyze the nucleation of barium sulfate, and iron and thorium were found to alter the mechanism of precipitation by ...

C. E. Bricker D. J. Myers

1969-01-01

361

Particulate barium fluxes and their relationships to biological productivity  

Microsoft Academic Search

To understand better the processes that control the transport of particulate barium through the water column and its preservation in marine sediments, we measured particulate barium fluxes along an equatorial transect at 140°W using moored sediment traps. The fluxes of barium correlate strongly with the fluxes of organic carbon; however, this relationship is non-linear—higher carbon fluxes have proportionately less associated

Jack Dymond; Robert Collier

1996-01-01

362

Barium titanate fabricated from fur-fibres  

Microsoft Academic Search

Long-fibrous barium titanate (BaTiO3) particles were prepared by a hydrothermal reaction of potassium titanate hydrate (2K2O·11TiO2·3H2O) and barium hydroxide (Ba(OH)2). Effects of preparation conditions on crystal structure and powder morphology were examined. Fur-fibres of K2O·4TiO2, 1–10 mm long and 1–100 ?m in diameter, were obtained by heating a mixture of K2CO3 and TiO2 powders at 1000 ‡C for 100 h.

Yoshinobu Ohara; Masaru Miyayama; Tadao Shimizu; Hiroaki Yanagida

1996-01-01

363

Electrodeposition of titania and barium titanate thin films for high dielectric applications  

NASA Astrophysics Data System (ADS)

In order to address the requirement of a low-temperature low-cost cost processing for depositing high dielectric constant ceramic films for applications in embedded capacitor and flexible electronics technology, two different chemical bath processes, namely, thermohydrolytic deposition (TD) and cathodic electrodeposition (ED) have been exploited to generate titania thin films. In thermohydrolytic deposition technique, titania films were generated from acidic aqueous solution of titanium chloride on F: SnO2 coated glass and Si substrates by temperature assisted hydrolysis mechanism. On the other hand, in cathodic electrodeposition, in-situ electro-generation of hydroxyl ions triggered a fast deposition of titania on conductive substrates such as copper and F: SnO2 coated glass from peroxotitanium solution at low temperatures (˜0°C). In both techniques, solution compositions affected the morphology and crystallinity of the films. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques have been employed to perform such characterization. As both processes utilized water as solvent, the as-deposited films contained hydroxyl ligand or physically adsorbed water molecules in the titania layer. Besides that, electrodeposited films contained peroxotitanium bonds which were characterized by FTIR studies. Although as-electrodeposited titania films were X-ray amorphous, considerable crystallinity could be generated by heat treatment. The films obtained from both the processes showed v moderately high dielectric constant (ranging from 9-30 at 100 kHz) and high breakdown voltage (0.09-0.15 MV/cm) in electrical measurements. To further improve the dielectric constant, electrodeposited titania films were converted to barium titanate films in high pH barium ion containing solution at 80-90°C. The resultant film contained cubic crystalline barium titanate verified by XRD analysis. Simple low-temperature hydrothermal technique of conversion worked perfect for F:SnO2 coated glass substrates, but in this process, high pH precursor caused corrosion in copper substrates and deposition of copper oxide in the final films. To overcome this, an innovative technique, which incorporates an electrochemical protection of substrates by application of cathodic potential in addition to common hydrothermal conversion, has been adopted. Films generated by common hydrothermal technique on F:SnO 2/glass substrates and via electrochemical-hydrothermal technique on Cu substrates showed promising dielectric behavior. Apart from the experimental studies, this report also includes various thermodynamic studies related to hydrolysis and precipitation of titanium ion, protection of copper during titania deposition and barium titanate conversion. Gibbs free energy based model and speciation studies were used to understand supersaturation which is a controlling factor in thermohydrolytic deposition. Similar approaches were utilized to understand the possibilities of barium titanate formation at different Ba2+ concentrations with different pH conditions. Possibilities of atmospheric carbon dioxide incorporation to generate barium carbonate instead of barium titanate formation were also determined by mathematical calculations. Whenever relevant, results of such theoretical analysis were utilized to design the experiment or to explain the experimental observations.

Roy, Biplab Kumar

364

Copper Efflux Is Induced during Anaerobic Amino Acid Limitation in Escherichia coli To Protect Iron-Sulfur Cluster Enzymes and Biogenesis.  

PubMed

Adaptation to changing environments is essential to bacterial physiology. Here we report a unique role of the copper homeostasis system in adapting Escherichia coli to its host-relevant environment of anaerobiosis coupled with amino acid limitation. We found that expression of the copper/silver efflux pump CusCFBA was significantly upregulated during anaerobic amino acid limitation in E. coli without the supplement of exogenous copper. Inductively coupled plasma mass spectrometry analysis of the total intracellular copper content combined with transcriptional assay of the PcusC-lacZ reporter in the presence of specific Cu(I) chelators indicated that anaerobic amino acid limitation led to the accumulation of free Cu(I) in the periplasmic space of E. coli, resulting in Cu(I) toxicity. Cells lacking cusCFBA and another copper transporter, copA, under this condition displayed growth defects and reduced ATP production during fumarate respiration. Ectopic expression of the Fe-S cluster enzyme fumarate reductase (Frd), or supplementation with amino acids whose biosynthesis involves Fe-S cluster enzymes, rescued the poor growth of ?cusC cells. Yet, Cu(I) treatment did not impair the Frd activity in vitro. Further studies revealed that the alternative Fe-S cluster biogenesis system Suf was induced during the anaerobic amino acid limitation, and ?cusC enhanced this upregulation, indicating the impairment of the Fe-S cluster assembly machinery and the increased Fe-S cluster demands under this condition. Taken together, we conclude that the copper efflux system CusCFBA is induced during anaerobic amino acid limitation to protect Fe-S cluster enzymes and biogenesis from the endogenously originated Cu(I) toxicity, thus facilitating the physiological adaptation of E. coli. PMID:23893112

Fung, Danny Ka Chun; Lau, Wai Yin; Chan, Wing Tat; Yan, Aixin

2013-07-26

365

Self-pumped phase conjugation with mechanism transformation in potassium sodium strontium barium niobate  

NASA Astrophysics Data System (ADS)

Both multistage and a great number of four-wave mixing interaction region models arising from contradirectional two-wave mixing to generate phase conjugation beam are suggested for the first time to our knowledge with a beam entering negative c face of the crystal. The mechanism transformation with geometric parameters is also observed and discussed. The backscattering beams from random noise beams may be expected to be amplified by contradirectional two-wave mixing under the beam entering negative c face of copper-doped potassium sodium strontium barium niobate. The maximum of reflectivity attains 33%.

Liangmin, Zhang; Zongshu, Shao; Xiaodong, Mu; Huanchu, Chen; Minhua, Jiang

1996-02-01

366

STABILIZED BARIUM TITANATE CERAMICS FOR CAPACITOR DIELECTRICS  

Microsoft Academic Search

The effects of additions of LaâOâ and LaâOâ--; 3TiOâ on the electronic properties of barium titanate were investigated. ; It was found that small additions of the components markedly increase the ; lifetime of the material subjected to d-c fields of 50 v per mil at 200 l ; C. (auth);

J. B. MacChesney; P. K. Gallagher; F. V. DiMarcello

1963-01-01

367

Prospects for Barium Tagging in Gaseous Xenon  

Microsoft Academic Search

Tagging events with the coincident detection of a barium ion would greatly reduce the background for a neutrino-less double beta decay search in xenon. This paper describes progress towards realizing this goal. It outlines a source that can produce large quantities of Ba++ in gas, shows that this can be extracted to vacuum, and demonstrates a mechanism by which the

D. Sinclair; E. Rollin; J. Smith; A. Mommers; N. Ackerman; B. Aharmim; M. Auger; P. S. Barbeau; C. Benitez-Medina; M. Breidenbach; A. Burenkov; S. Cook; A. Coppens; T. Daniels; R. DeVoe; A. Dobi; M. J. Dolinski; K. Donato; Fairbank W. Jr; J. Farine; G. Giroux

2012-01-01

368

Low Temperature Thermal Expansion of Barium Ferrite.  

National Technical Information Service (NTIS)

The linear thermal expansion of polycrystalline barium ferrite, BaFe12O19, was measured from 76 to 293 K both parallel and perpendicular to the magnetization direction. An anisotropy of about 15-20% was observed. The results match well the available data ...

A. F. Clark W. M. Haynes V. A. Deason R. J. Trapani

1975-01-01

369

Deflocculants for Tape Casting Barium Titanate Dielectrics.  

National Technical Information Service (NTIS)

The first part of this study has been directed towards understanding the mechanisms of dispersion for barium titanate in a methylathyl ketone-ethanol system using a commercial phosphate ester dispersant. The dispersant was found to be very effective in lo...

W. R. Cannon

1986-01-01

370

Deflocculants for Tape Casting Barium Titanate Dielectrics.  

National Technical Information Service (NTIS)

A typical nonaqueous tape casting system based on a commercial acrylic binder was studied to understand the system in more depth. The following conclusions were drawn: The best surfactants for dispersing barium titanate in the MEK-ethanol solvent system a...

W. R. Cannon

1988-01-01

371

Photorefraction in Barium-Titanate  

NASA Astrophysics Data System (ADS)

This thesis summarizes the results of experimental investigations of the photorefractive properties of melt -grown BaTiO(,3) single crystals. Three basic photorefractive material properties are studied: (1) the effective density of photorefractive charges, (2) the photoconductivity of the photorefractive charges, and (3) the relative contributions of electron and hole photoconduction. Volume holographic measurement techniques are used: two-beam energy coupling, four-wave mixing, and erasure of volume holograms. The photorefractive properties were altered experimentally by chemically reducing or oxidizing a BaTiO(,3) crystal. I have extended the "hopping conduction" model of photorefractive transport to include simultaneous electron and hole photoconduction. The extension of the hopping conduction model also describes all ranges of photorefractive site occupancy as observed in photorefractive crystals. The photorefractive speed, and hence the photoconductivity, is shown experimentally to be sublinear in the optical intensity in contrast to the predictions of existing models of photorefractive transport. A model of the photorefractive sites is proposed to explain the observed changes in the photorefractive properties of BaTiO(,3) when a crystal is oxidized or reduced. The model postulates that oxygen vacancies produced by reduction combine with iron impurities to form photorefractive donors, and that the remaining iron impurities are the photorefractive acceptors. The model of the photorefractive sites describes the experimental observation that the photorefractive sites switch from acceptor to donor and the photoconductivity from hole- to electron-dominated at the same density of oxygen vacancies as oxygen vacancies are introduced into a BaTiO(,3) crystal. The electrooptic and piezoelectric coefficients of BaTiO(,3) were measured by interferometric techniques and compared to holographic measurements. In addition, a technique for electrical poling of multidomain single crystals of BaTiO(,3) containing both 90(DEGREES) and 180(DEGREES) domain walls is described. (Copies available exclusively from Micrographics Department, Doheny Library, USC, Los Angeles, CA 90089-0182.).

Ducharme, Stephen

372

Metallurgy Beyond Iron  

Microsoft Academic Search

Metallurgy is one of the oldest sciences. Its history can be traced back to 6000 BCE with the discovery of Gold, and each new discovery - Copper, Silver, Lead, Tin, Iron and Mercury - marked the beginning of a new era of civilization. Currently there are 86 known metals, but until the end of the 17th century, only 12 of

Isabella Gallino; Ralf Busch

2009-01-01

373

Iron and Iron Deficiency  

MedlinePLUS

... them to get enough iron from their normal diet. Women who are pregnant have higher iron needs. To ... iron sources in the diet (e.g., vegetarian diets) Low absorption Taking antacids beyond ... Young children and pregnant women are at higher risk of iron deficiency because ...

374

Influence of chelators and iron ions on the production and degradation of H 2O 2 by ?-amyloid–copper complexes  

Microsoft Academic Search

?-Amyloid peptide (A?) 1–42, involved in the pathogenesis of Alzheimer’s disease, binds copper ions to form A?·Cun complexes that are able to generate H2O2 in the presence of a reductant and O2. The production of H2O2 can be stopped with chelators. More reactive than H2O2 itself, hydroxyl radicals HO (generated when a reduced redox active metal complex interacts with H2O2)

Céline Deraeve; Marguerite Pitie; Bernard Meunier

2006-01-01

375

ARE THERE ANY STARS LACKING NEUTRON-CAPTURE ELEMENTS? EVIDENCE FROM STRONTIUM AND BARIUM  

SciTech Connect

The cosmic dispersion in the abundances of the heavy elements strontium and barium in halo stars is well known. Strontium and barium are detected in most cool, metal-poor giants, but are these elements always detectable? To identify stars that could be considered probable candidates for lacking these elements, I examine the stellar abundance data available in the literature for 1148 field stars and 226 stars in dwarf galaxies, 776 of which have metallicities lower than [Fe/H] <-2.0. Strontium or barium have been detected in all field, globular cluster, and dwarf galaxy environments studied. All upper limits are consistent with the lowest detected ratios of [Sr/H] and [Ba/H]. The frequent appearance of these elements raises the intriguing prospect that at least one kind of neutron-capture reaction operates as often as the nucleosynthesis mechanisms that produce lighter elements, such as magnesium, calcium, or iron, although the yields of heavy elements may be more variable.

Roederer, Ian U., E-mail: iur@obs.carnegiescience.edu [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)

2013-01-01

376

High-field conduction in barium titanate  

NASA Astrophysics Data System (ADS)

We present current-voltage studies of very thin (~77 nm) barium titanate single crystals up to 1.3 GV/m applied field. These show that the mechanism of leakage current at high fields is that of space charge limited conduction (SCLC) in a regime with a continuous distribution of traps, according to the original model of Rose [Phys. Rev. 97, 1538 (1955)]. This study represents a factor of ×5 in field compared with the early studies of BaTiO3 conduction [A. Branwood et al., Proc. Phys. Soc. London 79, 1161 (1962)]. Comparison is also given with ceramic multilayer barium titanate capacitors, and with variable range hopping [B. I. Shklovskii, Sov. Phys. Semicond. 6, 1964 (1973)], reported in SrTiO3 films [D. Fuchs, M. Adam, and R. Schneider, J. Phys. IV France 11, 71 (2001)].

Morrison, F. D.; Zubko, P.; Jung, D. J.; Scott, J. F.; Baxter, P.; Saad, M. M.; Bowman, R. M.; Gregg, J. M.

2005-04-01

377

Electrical properties of polycrystalline PTCR barium titanate  

Microsoft Academic Search

Semiconducting n-type barium titanate with a positive temperature coefficient of resistance (PTCR) has been made by doping BaTiO3 with 0.4 mol% Ho2O3. The d.c. resistivity, a.c. resistivity (1.2 kHz) and relative permittivity (1.2 kHz) at different temperatures between room temperature and 523 K have been measured. The high relative permittivity and the PTCR effect are attributed to the existence of

M. A. A. Issa

1992-01-01

378

Densities of liquid metals: calcium, strontium, barium  

Microsoft Academic Search

We report a method of measuring the densities of liquids at intermediate temperatures which employs Archimedes' Principle in a two-sinker arrangement. This method is then used to measure the densities of pure liquid calcium, strontium, and barium. We find ?(Ca) = 1.4931 ? 1.37 × 10 T(°C) from 850 ? 950°C, ?(Sr) = 2.5547 ? 2.83 × 10 T(°C) from

S. Hiemstra; D. Prins; G. Gabrielse; J. B. Van Zytveld

1977-01-01

379

Prospects for Barium Tagging in Gaseous Xenon  

NASA Astrophysics Data System (ADS)

Tagging events with the coincident detection of a barium ion would greatly reduce the background for a neutrino-less double beta decay search in xenon. This paper describes progress towards realizing this goal. It outlines a source that can produce large quantities of Ba++ in gas, shows that this can be extracted to vacuum, and demonstrates a mechanism by which the Ba++ can be efficiently converted to Ba+ as required for laser identification.

Sinclair, D.; Rollin, E.; Smith, J.; Mommers, A.; Ackeran, N.; Aharmin, B.; Auger, M.; Barbeau, P. S.; Benitez-Medina, C.; Breidenbach, M.; Burenkov, A.; Cook, S.; Coppens, A.; Daniels, T.; DeVoe, R.; Dobi, A.; Dolinski, M. J.; Donato, K.; Fairbank, W., Jr.; Farine, J.; Giroux, G.; Gornea, G.; Graham, K.; Gratta, G.; Green, M.; Hagemann, C.; Hall, C.; Hall, K.; Hallman, D.; Hargrove, C.; Herrin, S.; Kaufman, L. K.; Leonard, D. S.; LePort, F.; Mackay, D.; MacLennan, R.; Mong, B.; Montero Díez, M.; Müller, A. R.; Neilson, R.; Niner, E.; Odian, A.; O'Sullivan, K.; Ouellet, C.; Piepke, A.; Pocar, A.; Prescott, C. Y.; Pushkin, K.; Rowson, P. C.; Slutsky, S.; Stekhanov, V.; Twelker, K.; Voskanian, N.; Vuilleumier, J.-L.; Wichoski, U.; Wodin, J.; Yang, L.; Yen, Y.-R.

2011-08-01

380

Electrical properties of barium-borosilicate glasses  

Microsoft Academic Search

Bulk and thin-blown films of barium-borosilicate glass were prepared and their electrical conduction properties at high and\\u000a low fields were measured as functions of temperature. The electrical conductivity is an exponential function of inverse temperature\\u000a at high temperatures with an activation energy in the range 1.0 to 1.4 eV, depending on composition. The conduction process\\u000a is believed to involve polarons

G. R. Moridi; A. Nouruzi; C. A. Hogarth

1991-01-01

381

Aqueous processing of barium titanate powders  

Microsoft Academic Search

In many modern electronic devices, multi-layer ceramic capacitors (MLCCs) are used in large quantities. For a greater volume efficiency of MLCCs, current efforts include thinner dielectric layers and a larger number of layers in a given volume, togethe r with embedded-capacitor design. All of these require a smaller particle size of the raw ceramic material, barium titanate (BaTiO3) powders, with

B. I. Lee; M. Wang; D. Yoon; M. Hu

2003-01-01

382

Development of barium tagging technology for EXO  

NASA Astrophysics Data System (ADS)

The Enriched Xenon Observatory (EXO) is a series of experiments designed to search for the neutrinoless double beta decay of Xenon-136. The first experiment, known as EXO-200, is comprised of a liquid xenon TPC containing 200 kg of xenon enriched to 80% in Xenon-136 and is nearing completion. To suppress possible radioactive backgrounds, the EXO collaboration is also pursuing the development of a new technique to identify the production of the barium daughter ions produced by double beta decay. For this purpose, a linear radio-frequency ion trap has been constructed. Individual barium ions are trapped in this helium or argon buffer gas-filled trap and observed with a high signal-to-noise ratio by resonance fluorescence. Furthermore, two ion transfer methods are under parallel development, both involving the capture and transport of the ions on the surface of a specially designed tip. This talk will present the results obtained in the trapping of single buffer gas-cooled barium ions and the transfer of ions using a cryogenic tip, and our plans for an ion transfer tip using resonance ionization spectroscopy.

Montero Diez, Maria

2008-04-01

383

Rapid barium removal in the Delaware estuary  

SciTech Connect

Six profiles of dissolved barium covering the entire salinity range of the Delaware River and Bay estuary from March through September 1996 were collected and analyzed. The profiles are similar to one another in both shape and magnitude except for one attribute. A sudden ({le} 24 days), nearly complete (>90%) removal of dissolved Ba in midestuary occurs in mid-May followed by an 80% recovery in early June. This removal appears to be temporally and spatially coupled to the end of the spring bloom. Based on such episodic behavior, and on recent work with flocculation of diatom exudates, the authors conclude that the Ba depletion is caused by barite precipitation in the estuary during the late stages of the bloom. This would imply that lower estuary and inner coastal margin sediments associated with eutrophic estuaries receive a seasonal pulse of barite. The suddenness of this event also implies that sedimentary barite is strongly influenced by high productivity events. Comparison of the riverine Ba concentration with the effective riverine end member after desorptive barium release yields an estimated 30--40 nM Ba available from the suspended sediments as they enter the estuary. This estimate is supported by excess barium in unfiltered samples over filtered samples taken from the river and also by calculations done elsewhere.

Stecher, H.A. III [Univ. of Delaware, Lewes, DE (United States). College of Marine Studies]|[Univ. of Delaware, Newark, DE (United States). Dept. of Geology; Kogut, M.B. [Univ. of Washington, Seattle, WA (United States). School of Oceanography

1999-04-01

384

Establishment of a Protocol for Determining Gastrointestinal Transit Time in Mice Using Barium and Radiopaque Markers  

PubMed Central

Objective The purpose of this study was to establish a minimally invasive and reproducible protocol for estimating the gastrointestinal (GI) transit time in mice using barium and radiopaque markers. Materials and Methods Twenty 5- to 6-week-old Balb/C female mice weighing 19-21 g were used. The animals were divided into three groups: two groups that received loperamide and a control group. The control group (n = 10) animals were administered physiological saline (1.5 mL/kg) orally. The loperamide group I (n = 10) and group II (n = 10) animals were administered 5 mg/kg and 10 mg/kg loperamide orally, respectively. Thirty minutes after receiving the saline or loperamide, the mice was administered 80 µL of barium solution and six iron balls (0.5 mm) via the mouth and the upper esophagus by gavage, respectively. Afterwards, the mice were continuously monitored with fluoroscopic imaging in order to evaluate the swallowing of the barium solution and markers. Serial fluoroscopic images were obtained at 5- or 10-min intervals until all markers had been excreted from the anal canal. For analysis, the GI transit times were subdivided into intestinal transit times (ITTs) and colon transit times (CTTs). Results The mean ITT was significantly longer in the loperamide groups than in the control group (p < 0.05). The mean ITT in loperamide group II (174.5 ± 32.3) was significantly longer than in loperamide group I (133.2 ± 24.2 minute) (p < 0.05). The mean CTT was significantly longer in loperamide group II than in the control group (p < 0.05). Also, no animal succumbed to death after the experimental procedure. Conclusion The protocol for our study using radiopaque markers and barium is reproducible and minimally invasive in determining the GI transit time of the mouse model.

Myagmarjalbuu, Bolormaa; Moon, Myeong Ju; Heo, Suk Hee; Jeong, Seo In; Park, Jong-Seong; Jun, Jae Yeoul; Kang, Heoung Keun

2013-01-01

385

Adaptation of Aerobically Growing Pseudomonas aeruginosa to Copper Starvation  

Microsoft Academic Search

Restricted bioavailability of copper in certain environments can interfere with cellular respiration because copper is an essential cofactor of most terminal oxidases. The global response of the metabolically versatile bacterium and opportunistic pathogen Pseudomonas aeruginosa to copper limitation was assessed under aerobic conditions. Expression of cioAB (encoding an alternative, copper-independent, cyanide-resistant ubiquinol oxidase) was upregulated, whereas numerous iron uptake functions

Emanuela Frangipani; Vera I. Slaveykova; Cornelia Reimmann; Dieter Haas

2008-01-01

386

Copper slag thermal storage -- projections of performance and economics  

Microsoft Academic Search

A solid residual regarded as waste from copper smelters, known as copper slag, offers an excellent medium for the storage of heat energy. Over one billion tons of slag is available at hundreds of smelters around the world. Copper slag is predominantly iron orthosilicate (2FeO.SiOâ), with sizable amounts of calcium, aluminum, magnesium and copper oxides. Formed in a highly oxidized

Curto

1984-01-01

387

Direct Production of Copper  

NASA Astrophysics Data System (ADS)

The use of commercially pure oxygen in flash smelting a typical chalcopyrite concentrate or a low grade comminuted matte directly to copper produces a large excess of heat. The heat balance is controlled by adjusting the calorific value of the solid feed. A portion of the sulfide material is roasted to produce a calcine which is blended with unroasted material, and the blend is then autogeneously smelted with oxygen and flux directly to copper. Either iron silicate or iron calcareous slags are produced, both being subject to a slag cleaning treatment. Practically all of the sulfur is contained in a continuous stream of SO2 gas, most of which is strong enough for liquefaction. A particularly attractive feature of these technologies is that no radically new metallurgical equipment needs to be developed. The oxygen smelting can be carried out not only in the Inco type flash furnace but in other suitable smelters such as cyclone furnaces. Another major advantage stems from abolishion of the ever-troublesome converter aisle, which is replaced with continuous roasting of a fraction of the copper sulfide feed.

Victorovich, G. S.; Bell, M. C.; Diaz, C. M.; Bell, J. A. E.

1987-09-01

388

Pyochelin, a siderophore of Pseudomonas aeruginosa: physicochemical characterization of the iron(III), copper(II) and zinc(II) complexes.  

PubMed

Pseudomonas aeruginosa is an opportunistic pathogen, synthesizing two major siderophores, pyoverdine (Pvd) and pyochelin (Pch), to cover its needs in iron(III). If the high affinity and specificity of Pvd toward iron(III) (pFe = 27.0) was well described in the literature, the physicochemical and coordination properties of Pch toward biologically relevant metals (Fe(III), Cu(II) or Zn(II)) have been only scarcely investigated. We report a thorough physico-chemical investigation of Pch (potentiometry, spectrophotometries, ESI/MS) that highlighted its moderate but significantly higher affinity for Fe(3+) (pFe = 16.0 at p[H] 7.4) than reported previously. We also demonstrated that Pch strongly chelates divalent metals such as Zn(II) (pZn = 11.8 at p[H] 7.4) and Cu(II) (pCu = 14.9 at p[H] 7.4) and forms predominantly 1 : 2 (M(2+)/Pch) complexes. Kinetic studies revealed that the formation of the ferric Pch complexes proceeds through a Eigen-Wilkins dissociative ligand interchange mechanism involving two protonated species of Pch and the Fe(OH)(2+) species of Fe(III). Our physico-chemical parameters supports the previous biochemical studies which proposed that siderophores are not only devoted to iron(III) shuttling but most likely display other specific biological role in the subtle metals homeostasis in microorganisms. This work also represents a step toward deciphering the role of siderophores throughout evolution. PMID:22261733

Brandel, Jérémy; Humbert, Nicolas; Elhabiri, Mourad; Schalk, Isabelle J; Mislin, Gaëtan L A; Albrecht-Gary, Anne-Marie

2012-01-20

389

Simultaneous removal of nitrate and heavy metals by iron metal*  

PubMed Central

Great attention should be paid now to simultaneously removing common pollutants, especially inorganic pollutants such as nitrate and heavy metals, as individual removal has been investigated extensively. Removing common pollutants simultaneously by iron metal is a very effective alternative method. Near neutral pH, heavy metals, such as copper and nickel, can be removed rapidly by iron metal, while nitrate removal very much slower than that of copper and nickel, and copper can accelerate nitrate removal when both are removed simultaneously. Even a little amount of copper can enhance nitrate removal efficiently. Different mechanisms of these contaminants removal by iron metal were also discussed.

Hao, Zhi-wei; Xu, Xin-hua; Jin, Jian; He, Ping; Liu, Yong; Wang, Da-hui

2005-01-01

390

Copper-tuned magnetic order and excitations in iron-based superconductors Fe1+yTe1-xSex  

NASA Astrophysics Data System (ADS)

We report neutron scattering results on the Cu-substitution effects in the iron-based superconductors, Fe1+yTe1-xSex. In the parent compound, it is found that Cu drives the low-temperature magnetic ground state from long-range commensurate antiferromagnetic order in Fe1.06TeCu0.04 to short-range incommensurate order in FeTeCu0.1. In the former sample, the structural and magnetic ordering temperature is 40 K; in FeTeCu0.1, the structural phase transition is not obvious and a transition to the spin-glass state is found at 22 K. Cu suppresses superconductivity in FeTe0.5Se0.5---Tc is reduced to 7 K with a 2% Cu doping, and no superconductivity is found in the 10% Cu-doped sample. In the meantime, the intensity and energy of the resonance mode are suppressed in the 2% Cu-doped sample, while there is no resonance in the non-superconducting sample. Besides, the low-temperature magnetic excitation spectra are distinct for these two samples, with the superconducting one having an ``hour-glass" shape and the other one having a ``waterfall" shape. Our results provide further insights on the interplay between magnetism and superconductivity in the iron-based superconductors.

Wen, Jinsheng; Xu, Zhijun; Xu, Guangyong; Lumsden, Mark; Matsuda, Masaaki; Valdivia, Patrick; Bourret, Edith; Lee, Dunghai; Gu, Genda; Tranquada, John; Birgeneau, Robert

2012-02-01

391

Barium Granuloma of the Rectum: An Uncommon Complication of Barium Enema  

PubMed Central

Barium sulfate granuloma of the rectum may develop when this contrast material is forced through a discontinuity in the rectal mucosa. The ensuing mass may be confused with carcinoma. Preoperative biopsy and attention to plain films will prevent unnecessary inappropriate surgery. ImagesFig. 1.Fig. 2.Fig. 3a.Fig. 3b.

Lewis, Joseph W.; Kerstein, Morris D.; Koss, Neal

1975-01-01

392

Determination of calcium, copper, iron, magnesium, manganese, potassium, phosphorus, sodium, and zinc in fortified food products by microwave digestion and inductively coupled plasma-optical emission spectrometry: single-laboratory validation and ring trial.  

PubMed

A single-laboratory validation (SLV) and a ring trial (RT) were undertaken to determine nine nutritional elements in food products by inductively coupled plasma-optical emission spectrometry in order to modernize AOAC Official Method 984.27. The improvements involved extension of the scope to all food matrixes (including infant formula), optimized microwave digestion, selected analytical lines, internal standardization, and ion buffering. Simultaneous determination of nine elements (calcium, copper, iron, potassium, magnesium, manganese, sodium, phosphorus, and zinc) was made in food products. Sample digestion was performed through wet digestion of food samples by microwave technology with either closed- or open-vessel systems. Validation was performed to characterize the method for selectivity, sensitivity, linearity, accuracy, precision, recovery, ruggedness, and uncertainty. The robustness and efficiency of this method was proven through a successful RT using experienced independent food industry laboratories. Performance characteristics are reported for 13 certified and in-house reference materials, populating the AOAC triangle food sectors, which fulfilled AOAC criteria and recommendations for accuracy (trueness, recovery, and z-scores) and precision (repeatability and reproducibility RSD, and HorRat values) regarding SLVs and RTs. This multielemental method is cost-efficient, time-saving, accurate, and fit-for-purpose according to ISO 17025 Norm and AOAC acceptability criteria, and is proposed as an extended updated version of AOAC Official Method 984.27 for fortified food products, including infant formula. PMID:22468357

Poitevin, Eric

393

DITHIOCARBAMATES DERIVED FROM NATURALLY OCCURING AMINO ACIDS AND THEIR COMPLEXES WITH NICKEL AND COPPER  

Microsoft Academic Search

Dithiocarbamates of tryptophane (tryp), lysine (lys) and arginine (arg) have been synthetized by direct rection of the corresponding amino acid with carbon sulphide in a basic medium. Barium salts isolated had formulae Ba(dtc tryp), Ba3(dtc lys)2 and Ba3(dtc arg)2. These dithiocarbamates react with nickel(II) salts forming square-planar complexes. However, reaction copper(II) salts leads to reduction to copper(I).

Benigno Macías; María V. Villa; Alfonso Mateos; Myriam Páramo

1998-01-01

394

Composition and structure measurements in an ionospheric barium cloud  

NASA Astrophysics Data System (ADS)

A 48 kg barium payload was launched from Eglin Air Force Base, Florida on 12 December 1980 at 2311 GMT and detonated at 183.7 km. At 2342:50.25 GMT, a second rocket, instrumented with an ion mass spectrometer and pulsed plasma probes, was fired to traverse the barium cloud. Composition, ion density, and structure measurements were acquired up to 241.2 km in both the natural and disturbed ionosphere. The rocket penetrated the barium cloud between 147 and 184 km. In addition to the Ba+, Ba++ produced by H Lyman alpha ionization, and Ca+, an impurity in the barium were detected in the cloud. A peak barium ion concentration of about 6,000,000 ions cu cm was measured at 161 km where the ionospheric NO+ and O2+ ions were essentially eliminated by large recombination loss. The bottom side of the barium cloud had a relatively smooth structure while the top side showed significant density fluctuations. The first experimental evidence of a theoretically predicted E region 'image cloud' was found in the form of an enhanced NO+ layer just below the barium cloud. Unexplained wave-like density variations in O+, NO+, and O2(+) also were seen above the barium cloud to 195 km. A quantitative estimate of the outgassing water vapor concentrations near the payload's surface was made using the fast change transfer rate coefficient for O+ + H2O yields H2O+ + O that created the observed water vapor ions.

Narcisi, R.; Tracinski, E.; Federico, G.; Wlodyka, L.; Bench, P.

1981-12-01

395

A study of positional disorder in strontium barium niobate  

Microsoft Academic Search

The first systematic examination of trends in the site occupancies of strontium and barium ions in strontium barium niobate (SBN) at three compositions across the phase range is presented. X-ray powder diffraction and Rietveld structure refinement were used to obtain refined structures for SBN. Some problems were encountered in the structure refinement due to the domain structure in the material.

M. P. Trubelja; E. Ryba; D. K. Smith

1996-01-01

396

Acute barium intoxication following ingestion of ceramic glaze.  

PubMed Central

A case of deliberate overdose of barium sulphide in a psychiatric setting is presented, with resulting flaccid paralysis, malignant arrhythmia, respiratory arrest and severe hypokalaemia, but ultimately with complete recovery. The degree of paralysis appears to be related directly to serum barium levels. The value of early haemodialysis, particularly with respiratory paralysis and hypokalaemia, is emphasised.

Thomas, M.; Bowie, D.; Walker, R.

1998-01-01

397

SEPARATION OF RADIUM AND BARIUM BY ION EXCHANGE ELUTION  

Microsoft Academic Search

Radium can be separated from barium-radium mixtures in ratios as high as ; 4440to 1 by a single elution from a cation exchange resin. Bariuim elution ; characteristics from Dowex 50 resin, position of elution maxima, and maximum ; barium loadings are correlated with citrate concentration and pH by the use of ; citrate complex equilibria, Ammonium citrate, 0.32M at

W. H. Power; H. W. Kirby; W. C. McCluggage; G. D. Nelson; J. H. Jr. Payne

1959-01-01

398

Thermal decomposition of (BaTi) citrates into barium titanate  

Microsoft Academic Search

From aqueous solutions of barium and titanium citrates two different (BaTi) citrate salts can be precipitated, depending on the pH of the solution. The ratio of barium to titanium in the salts is either 1 : 1 or 2 : 1. The thermal decomposition of the salts was investigated by means of DTA, TGA, infrared spectroscopy, and X-ray diffraction. At

D. Hennings; W. Mayr

1978-01-01

399

Barium in Teeth as Indicator of Body Burden.  

National Technical Information Service (NTIS)

A study was conducted to determine the biological availability of naturally occurring barium in a municipal drinking water by the analysis of barium in deciduous teeth of children. The grade school children of two Illinois towns were chosen for the study....

R. G. Miller J. D. B. Featherstone M. E. J. Curzon T. S. Mills C. P. Shields

1985-01-01

400

Protection of iron powder by heavy-metal azelates  

Microsoft Academic Search

Conclusions 1.A method is proposed for protecting iron powder against atmospheric corrosion by impregnating it with lead, zinc, calcium or barium azelate.2.It was established that the protective effect of heavy-metal azelates is due to their hydrophobizing effect.3.Treatment of iron powder with azelates improves the distribution of its grain sizes by reducing the content of the fine fractions.4.Under the same test

A. P. Brynza; N. A. Kormshchikova

1966-01-01

401

Europium-doped barium bromide iodide  

SciTech Connect

Single crystals of Ba0.96Eu0.04BrI (barium europium bromide iodide) were grown by the Bridgman technique. The title compound adopts the ordered PbCl2 structure [Braekken (1932). Z. Kristallogr. 83, 222-282]. All atoms occupy the fourfold special positions (4c, site symmetry m) of the space group Pnma with a statistical distribution of Ba and Eu. They lie on the mirror planes, perpendicular to the b axis at y = +-0.25. Each cation is coordinated by nine anions in a tricapped trigonal prismatic arrangement.

Gundiah, Gautam; Hanrahan, Stephen M.; Hollander, Fredrick J.; Bourret-Courchesne, Edith D.

2009-10-21

402

Barium silicate films for integrated optical circuits.  

PubMed

This paper describes the preparation and properties of rf sputtered barium silicate films that are suitable for use as transmission media in integrated optical circuits. It is shown that the films, which can be produced with a wide range of refractive indices by suitable selection of the ratio of the target constituents, exhibit low optical attenuation. The techniques used to deposit the films and the effect on loss of a number of parameters including pressure, film thickness, and substrate bias are discussed. PMID:20125380

Goell, J E

1973-04-01

403

Scattering lengths of calcium and barium isotopes  

SciTech Connect

We have calculated the s-wave scattering length of all the even isotopes of calcium (Ca) and barium (Ba) in order to investigate the prospect of Bose-Einstein condensation (BEC). For Ca we have used an accurate molecular potential based on detailed spectroscopic data. Our calculations show that Ca does not provide other isotopes alternative to the recently Bose condensed {sup 40}Ca that suffers strong losses because of a very large scattering length. For Ba we show by using a model potential that the even isotopes cover a broad range of scattering lengths, opening the possibility of BEC for at least one of the isotopes.

Dammalapati, U.; Willmann, L.; Knoop, S. [Kernfysisch Versneller Instituut (KVI), University of Groningen, Zernikelaan 25, 9747 AA Groningen (Netherlands); LaserLaB Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam (Netherlands)

2011-11-15

404

Evaluation of barium hydroxide treatment efficacy on a dolomitic marble.  

PubMed

The Arch of Peace, by Luigi Cagnola, is one of the most famous neoclassical monuments in Milan. It has been subjected to conservative intervention in 1998. In the present paper the efficacy of the consolidation by means of barium hydroxide has been evaluated. The stone material showed severe degradation phenomena as: erosion, pulverisation, exfoliation. The analytical data acquired through X-ray diffraction (XRD), infrared spectrophotometry (FTIR) and scanning electron microscopy (SEM-EDX), allowed to compare the conditions of stone before and after the treatment with barium hydroxide. The presence of barium has been put in evidence mainly on the surface as barium sulphate, whereas barium is only sporadically present within the thickness of the decayed material. The treatment was judged not satisfying and its inefficacy is, most probably, due to a not suitable cleaning procedure carried out before the consolidation. PMID:11836959

Toniolo, L; Colombo, C; Realini, M; Peraio, A; Positano, M

405

How to Perform and Interpret Timed Barium Esophagogram  

PubMed Central

Timed barium esophagogram (TBE) is a simple and objective method for assessing the esophageal emptying. The technique of TBE is similar to usual barium swallow with some modifications, which include taking multiple sequential films at pre-decided time interval after a single swallow of a fixed volume of a specific density barium solution. While many authors have used height and width of the barium column to assess the esophageal emptying, others have used the area of the barium column. TBE is being used in patients with suspected or confirmed achalasia and to follow-up those who have been treated with pneumatic dilation or myotomy. This review discusses technique of performing TBE, interpretation and its utility in clinical practice.

Gupta, Mahesh; Ghoshal, Uday C

2013-01-01

406

Dispersion strengthened copper  

DOEpatents

A composition of matter comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide, and a method for making this composition of matter.

Sheinberg, Haskell (Los Alamos, NM); Meek, Thomas T. (Knoxville, TN); Blake, Rodger D. (Santa Fe, NM)

1990-01-01

407

Dispersion strengthened copper  

DOEpatents

A composition of matter comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide, and a method for making this composition of matter.

Sheinberg, Haskell (Los Alamos, NM); Meek, Thomas T. (Knoxville, TN); Blake, Rodger D. (Santa Fe, NM)

1989-01-01

408

Impact of Copper Limitation on Expression and Function of Multicopper Oxidases (Ferroxidases)12  

PubMed Central

Copper is an essential trace element whose recommended intake is met by most North American diets. However, incidence of new cases of secondary copper deficiency is rising due to complications of gastric bypass surgery and high zinc exposure. Patients frequently are ataxic and anemic. Anemia of copper deficiency was first described in the 19th century, but the underlying biochemistry remains unknown. Approximately one dozen cuproenzymes have been characterized in mammals. Four of these are referred to as multicopper oxidases (MCO) due to their copper binding geometries. They have iron oxidase activity (ferroxidase). These include the hepatic secreted protein ceruloplasmin representing ?90% of plasma copper, a splice-variant of ceruloplasmin originally characterized in brain linked by glycosylphosphatidylinositol (GPI) to membranes, an intestinal enriched MCO named hephaestin, and newly described MCO in placenta called zyklopen. Limitation in available copper appears to limit function of the MCO group exhibited as impaired iron flux due to the copper requirement of MCO for their ferroxidase activity. Dietary copper deficiency is associated with lower levels of ceruloplasmin, GPI-ceruloplasmin, and hephaestin. Limitation of copper does not appear to limit synthesis of MCO but rather their stability and turnover. However, there appears to be a disconnect between limitation in MCO function and anemia, because humans and mice missing ceruloplasmin are not anemic despite hepatic iron overload and hypoferremia. Furthermore, anemic copper-deficient mammals are not improved by iron replacement. This suggests that the anemia of copper deficiency is not caused by iron limitation but rather impairment in iron utilization.

Prohaska, Joseph R.

2011-01-01

409

Neutron diffraction studies on ABO3 (A=Lanthanum, Strontium, B=Iron, Cobalt , Nickel, Copper, Manganese, Titanium) perovskite used in solid oxide fuel cell (SOFC) and double perovskite Barium2YttriumRuthenium0.85Copper0.15Oxygen6 superconductor  

NASA Astrophysics Data System (ADS)

ABO3(A=La, Sr, B=Fe, Co, Ni, Cu, Mn, Ti) perovskites are of great interest due to their mixed electronic and oxygen ion conductivity. They are candidates for the electrodes of SOFCs. The mixed conductivity can be enhanced through the substitution of La3+ by Sr2+ at A sites, and the substitution of Fe3+ by other transition metal ions at B sites. The charge imbalance and overall charge neutrality can be maintained by the presence of charged oxygen vacancies and mixed valence state ions at the B sites. These point defects are the origin of the mixed electronic and oxygen ion conductivity. This study investigates the effects of substitutions at A sites and/or B sites on the crystal and magnetic structure, oxygen vacancies, and the thermal expansion coefficients at different temperatures and gaseous environment. The oxygen vacancy concentration can relax the perovskite distortion and has a close relationship with the magnetic properties. La0.6Sr0.4FeO3-delta, La0.6Sr0.4Fe0.8Co0.2O3-delta , and La0.8Sr0.2Fe0.8Co0.2O 3-delta can be good candidates for the cathodes of SOFCs at intermediate temperature. The double perovskite Ba2YRu0.85Cu0.15O 6 superconductor and a mixture of 5wt% YBa2Cu3O 7-delta and undoped Ba2YRuO6 were investigated with the aid of neutron diffraction. The 1:1 B site ordering is observed and long range antiferromagnetic ordering of the Ru sublattice with a type I magnetic structure appears when the temperature is below 38K. An incommensurate antiferromagnetic ordering of Cu is observed in the temperature range 38K-85K. This ordering is not seen in undoped material. The decomposition of Cu-doped Ba2YRuO6 into undoped Ba 2YRuO6 and YBa2Cu3O7-delta is not seen. YBa2Cu3O7-delta is not stable at the temperature used to prepare the Cu-doped Ba2YRuO6 superconductor. These results confirm the presence of superconductivity without CuO2 planes.

Cai, Qingsheng

410

Fracture toughness of austempered chilled ductile iron  

Microsoft Academic Search

The structure and properties of ductile iron are highly dependent on the solidification mechanism and chills are used to promote directional solidification to get sound castings. A series of fracture toughness experiments were carried out involving austempered chilled ductile iron containing 3.42% C, 1.8% Si and other alloying elements. By using copper chills of different thickness, the fracture toughness of

Joel Hemanth

1998-01-01

411

Proton conductivity of potassium doped barium zirconates  

SciTech Connect

Potassium doped barium zirconates have been synthesized by solid state reactions. It was found that the solubility limit of potassium on A-sites is between 5% and 10%. Introducing extra potassium leads to the formation of second phase or YSZ impurities. The water uptake of barium zirconates was increased even with 5% doping of potassium at the A-site. The sintering conditions and conductivity can be improved significantly by adding 1 wt% ZnO during material synthesis. The maximum solubility for yttrium at B-sites is around 15 at% after introducing 1 wt% zinc. The conductivity of Ba{sub 0.95}K{sub 0.05}Zr{sub 0.85}Y{sub 0.11}Zn{sub 0.04}O{sub 3-{delta}} at 600 deg. C is 2.2x10{sup -3} S/cm in wet 5% H{sub 2}. The activation energies for bulk and grain boundary are 0.29(2), 0.79(2) eV in wet 5% H{sub 2} and 0.31(1), 0.74(3) eV in dry 5% H{sub 2}. A power density of 7.7 mW/cm{sup 2} at 718 deg. C was observed when a 1 mm thick Ba{sub 0.95}K{sub 0.05}Zr{sub 0.85}Y{sub 0.11}Zn{sub 0.04}O{sub 3-{delta}} pellet was used as electrolyte and platinum electrodes. - Graphical abstract: Potassium doped barium zirconates have been synthesized by solid state reactions. It was found that the solubility limit of potassium on A-sites is between 5% and 10 %. The sintering conditions and conductivity can be improved significantly by adding 1 wt% ZnO during material synthesis. Five percent doping of potassium at A-site can double the total conductivity.

Xu Xiaoxiang [School of Chemistry, University of St. Andrews, Fife KY16 9ST (United Kingdom); Tao Shanwen, E-mail: s.tao@hw.ac.u [School of Chemistry, University of St. Andrews, Fife KY16 9ST (United Kingdom); Department of Chemistry, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Irvine, John T.S. [School of Chemistry, University of St. Andrews, Fife KY16 9ST (United Kingdom)

2010-01-15

412

Migration and redistribution of oxygen vacancy in barium titanate ceramics  

NASA Astrophysics Data System (ADS)

Degradation of barium titanate based multilayer capacitor mainly results from migration and redistribution of oxygen vacancy. For barium titanate ceramics, the authors observe an internal friction relaxation peak around 70 °C due to oxygen vacancy, and its relaxation strength differs greatly for specimen aged at 85 °C for 120 h and at 150 °C for 5 h. Two possible explanations are proposed, one based on symmetry-conforming short-range order while the other on the interaction between oxygen vacancy and domain wall during aging process. In any case, relaxation thermodynamics is a powerful tool to investigate the migration and redistribution of oxygen vacancy in barium titanate ceramics.

Chen, L.; Xiong, X. M.; Meng, H.; Lv, P.; Zhang, J. X.

2006-08-01

413

A high-altitude barium radial injection experiment  

NASA Astrophysics Data System (ADS)

A rocket launched from Poker Flat, Alaska, carried a new type of high-explosive barium shaped charge to 571 km, where detonation injected a thin disk of barium vapor with high velocity nearly perpendicular to the magnetic field. The TV images of the injection are spectacular, revealing three major regimes of expanding plasma which showed early instabilities in the neutral gas. The most unusual effect of the injection is a peculiar rayed barium-ion structure lying in the injection plane and centered on a 5 km 'black hole' surrounding the injection point. Preliminary electrostatic computer simulations show a similar rayed development.

Wescott, E. M.; Stenbaek-Nielsen, H. C.; Hallinan, T. J.; Deehr, C. S.; Romick, G. J.; Olson, J. V.; Roederer, J. G.; Sydora, R.

1980-12-01

414

Hepatic Copper Accumulation Induces DNA Strand Breaks in the Liver Cells of Long-Evans Cinnamon Strain Rats  

Microsoft Academic Search

Effects of accumulation of copper and iron on the production of DNA strand breaks were investigated in Long-Evans Cinnamon (LEC) strain rats that spontaneously develop fulminant hepatitis. Copper and iron accumulated in the liver of LEC rats in an age-dependent manner from 4 to 15 weeks. Low-copper food prevented the accumulation of copper in the liver, but did not prevent

Masanobu Hayashi; Tomoko Kuge; Daiji Endoh; Kenji Nakayama; Jiro Arikawa; Akira Takazawa; Toyo Okui

2000-01-01

415

Synthesis and characterization of barium hexagonal ferrite  

NASA Astrophysics Data System (ADS)

Barium Hexagonal ferrite (BaFe12O19) was synthesized by a two step process, first by high-energy ball milling and then sintering the milled powder subsequently at 950°C. The phase formation and morphology studies were carried out using X-ray Diffraction (XRD) and High Resolution Scanning Electron Microscopy (HRSEM) respectively. XRD results clearly show the phase purity and the good crystalline nature of BaFe12O19. The mean particle size was found to be 80 nm from the SEM image. The magnetic properties such as saturation magnetization and coercive field were calculated from the magnetization curve, which was obtained using Vibrating Sample Magnetometer (VSM). A possible relation between the magnetic hysteresis curve and the microstructure of the sintered sample has been investigated.

Manikandan, M.; Venkateswaran, C.

2013-02-01

416

Effect of Strain Hardening on Friction Behavior of Iron Lubricated with Benzyl Structures.  

National Technical Information Service (NTIS)

Sliding friction experiments were conducted with iron, copper, and aluminum in contact with iron in various states of strain. The surfaces were examined in dry sliding and with various benzyl compounds applied as lubricants. Friction experiments were cond...

D. H. Buckley W. A. Brainard

1974-01-01

417

Yellow discoloration in veal calves: the role of hepatic copper  

Microsoft Academic Search

Liver samples from four groups of calves were analysed chemically and histologically for copper and iron levels. Milk replacer-fed 'yellow' calves were compared with milk replacer-fed 'white' calves, concentrate and silage-fed 'pink' calves and concentrate and silage-fed young 'red' fattening bulls. In the milk replacer-fed calves high copper and low iron levels were measured in the liver, whereas in the

MJ Groot; E Gruys

1993-01-01

418

Mechanisms of Copper Ion Mediated Huntington's Disease Progression  

Microsoft Academic Search

Huntington's disease (HD) is caused by a dominant polyglutamine expansion within the N-terminus of huntingtin protein and results in oxidative stress, energetic insufficiency and striatal degeneration. Copper and iron are increased in the striata of HD patients, but the role of these metals in HD pathogenesis is unknown. We found, using inductively-coupled-plasma mass spectroscopy, that elevations of copper and iron

Jonathan H. Fox; Jibrin A. Kama; Gregory Lieberman; Raman Chopra; Kate Dorsey; Vanita Chopra; Irene Volitakis; Robert A. Cherny; Ashley I. Bush; Steven Hersch; Katrina Gwinn-Hardy

2007-01-01

419

Iron, transferrin and myelinogenesis  

NASA Astrophysics Data System (ADS)

Transferrin (Tf), the iron binding protein of vertebrates serum, is known to be synthesized by oligodendrocytes (Ols) in the central nervous system. It has been postulated that Tf is involved in Ols maturation and myelinogenesis. This link is particularly important in the understanding of a severe human pathology: the multiple sclerosis, which remains without efficient treatment. We generated transgenic mice containing the complete human Tf gene and extensive regulatory sequences from the 5' and 3' untranslated regions that specifically overexpress Tf in Ols. Brain cytoarchitecture of the transgenic mice appears to be normal in all brain regions examined, total myelin content is increased by 30% and motor coordination is significantly improved when compared with non-transgenic littermates. Tf role in the central nervous system may be related to its affinity for metallic cations. Normal and transgenic mice were used for determination of trace metals (iron, copper and zinc) and minerals (potassium and calcium) concentration in cerebellum and corpus callosum. The freeze-dried samples were prepared to allow proton-induced X-ray emission and Rutherford backscattering spectrometry analyses with the nuclear microprobe in Bordeaux. Preliminary results were obtained and carbon distribution was revealed as a very good analysis to distinguish precisely the white matter region. A comparison of metallic and mineral elements contents in brain between normal and transgenic mice shows that iron, copper and zinc levels remained constant. This result provides evidence that effects of Tf overexpression in the brain do not solely relate to iron transport.

Sergeant, C.; Vesvres, M. H.; Devès, G.; Baron, B.; Guillou, F.

2003-09-01

420

Physico-chemical properties of copper electrorefining and electrowinning electrolytes  

NASA Astrophysics Data System (ADS)

Densities, viscosities, electrical conductivities and specific heats of solutions containing copper, nickel, arsenic, iron and sulphuric acid in the concentration ranges of copper electrorefining and electrowinning electrolytes have been measured. Equations are presented for calculating these properties as a function of electrolyte composition and temperature.

Price, Derek C.; Davenport, William G.

1981-12-01

421

Physicochemical properties of copper electrorefining and electrowinning electrolytes  

Microsoft Academic Search

Densities, viscosities, electrical conductivities and specific heats of solutions containing copper, nickel, arsenic, iron\\u000a and sulphuric acid in the concentration ranges of copper electrorefining and electrowinning electrolytes have been measured.\\u000a Equations are presented for calculating these properties as a function of electrolyte composition and temperature.

Derek C. Price; William G. Davenport

1981-01-01

422

Physicochemical properties of copper electrorefining and electrowinning electrolytes  

Microsoft Academic Search

Densities, viscosities, electrical conductivities and specific heats of solutions containing copper, nickel, arsenic, iron and sulphuric acid in the concentration ranges of copper electrorefining and electrowinning electrolytes have been measured. Equations are presented for calculating these properties as a function of electrolyte composition and temperature.

Derek C. Price; William G. Davenport

1981-01-01

423

Microscopic Theory of the Phonon Frequencies in bcc Barium.  

National Technical Information Service (NTIS)

The phonon dispersion frequencies are calculated from first principles for bbc barium using a resonance pseudopotential model which incorporates the effect of s-d hybridization. It was also possible using this scheme to account for the anomalous feature o...

B. A. Oli

1988-01-01

424

Calculated emission rates for barium releases in space  

NASA Astrophysics Data System (ADS)

The optical emissions from barium releases in space are caused by resonance and fluorescent scattering of sunlight. Emission rates for the dominant ion and neutral lines are calculated assuming the release to be optically thin and the barium to be in radiative equilibrium with the solar radiation. The solar spectrum has deep Fraunhofer absorption lines at the primary barium ion resonances. A velocity component toward or away from the sun will Doppler shift the emission lines relative to the absorption lines and the emission rates will increase many-fold over the rest value. The Doppler brightening is important in shaped charge or satellite releases where the barium is injected at high velocities. Emission rates as a function of velocity are calculated for the 4554, 4934, 5854, 6142 and 6497 A ion emission lines and the dominant neutral line at 5535 A. Results are presented for injection parallel to the ambient magnetic field, B, and for injection at an angle to B.

Stenbaek-Nielsen, H. C.

1989-11-01

425

Intracellular Copper Does Not Catalyze the Formation of Oxidative DNA Damage in Escherichia coli?  

PubMed Central

Because copper catalyzes the conversion of H2O2 to hydroxyl radicals in vitro, it has been proposed that oxidative DNA damage may be an important component of copper toxicity. Elimination of the copper export genes, copA, cueO, and cusCFBA, rendered Escherichia coli sensitive to growth inhibition by copper and provided forcing circumstances in which this hypothesis could be tested. When the cells were grown in medium supplemented with copper, the intracellular copper content increased 20-fold. However, the copper-loaded mutants were actually less sensitive to killing by H2O2 than cells grown without copper supplementation. The kinetics of cell death showed that excessive intracellular copper eliminated iron-mediated oxidative killing without contributing a copper-mediated component. Measurements of mutagenesis and quantitative PCR analysis confirmed that copper decreased the rate at which H2O2 damaged DNA. Electron paramagnetic resonance (EPR) spin trapping showed that the copper-dependent H2O2 resistance was not caused by inhibition of the Fenton reaction, for copper-supplemented cells exhibited substantial hydroxyl radical formation. However, copper EPR spectroscopy suggested that the majority of H2O2-oxidizable copper is located in the periplasm; therefore, most of the copper-mediated hydroxyl radical formation occurs in this compartment and away from the DNA. Indeed, while E. coli responds to H2O2 stress by inducing iron sequestration proteins, H2O2-stressed cells do not induce proteins that control copper levels. These observations do not explain how copper suppresses iron-mediated damage. However, it is clear that copper does not catalyze significant oxidative DNA damage in vivo; therefore, copper toxicity must occur by a different mechanism.

Macomber, Lee; Rensing, Christopher; Imlay, James A.

2007-01-01

426

Inhibition of copper uptake in yeast reveals the copper transporter Ctr1p as a potential molecular target of saxitoxin.  

PubMed

Saxitoxin is a secondary metabolite produced by several species of dinoflagellates and cyanobacteria which targets voltage-gated sodium and potassium channels in higher vertebrates. However, its molecular target in planktonic aquatic community members that co-occur with the toxin producers remains unknown. Previous microarray analysis with yeast identified copper and iron-homeostasis genes as being differentially regulated in response to saxitoxin. This study sought to identify the molecular target in microbial cells by comparing the transcriptional profiles of key copper and iron homeostasis genes (CTR1, FRE1, FET3, CUP1, CRS5) in cells exposed to saxitoxin, excess copper, excess iron, an extracellular Cu(I) chelator, or an intracellular Cu(I) chelator. Protein expression and localization of Ctr1p (copper transporter), Fet3p (multicopper oxidase involved in high-affinity iron uptake), and Aft1p (iron regulator) were also compared among treatments. Combined transcript and protein profiles suggested saxitoxin inhibited copper uptake. This hypothesis was confirmed by intracellular Cu(I) imaging with a selective fluorescent probe for labile copper. On the basis of the combined molecular and physiological results, a model is presented in which the copper transporter Ctr1p serves as a molecular target of saxitoxin and these observations are couched in the context of the eco-evolutionary role this toxin may serve for species that produce it. PMID:22304436

Cusick, Kathleen D; Minkin, Steven C; Dodani, Sheel C; Chang, Christopher J; Wilhelm, Steven W; Sayler, Gary S

2012-02-16

427

Copper modulates the degradation of copper chaperone for Cu,Zn superoxide dismutase by the 26 S proteosome.  

PubMed

Copper chaperones are copper-binding proteins that directly insert copper into specific targets, preventing the accumulation of free copper ions that can be toxic to the cell. Despite considerable advances in the understanding of copper transfer from copper chaperones to their target, to date, there is no information regarding how the activity of these proteins is regulated in higher eukaryotes. The insertion of copper into the antioxidant enzyme Cu,Zn superoxide dismutase (SOD1) depends on the copper chaperone for SOD1 (CCS). We have recently reported that CCS protein is increased in tissues of rats fed copper-deficient diets suggesting that copper may regulate CCS expression. Here we show that whereas copper deficiency increased CCS protein in rats, mRNA level was unaffected. Rodent and human cell lines cultured in the presence of the specific copper chelator 2,3,2-tetraamine displayed a dose-dependent increase in CCS protein that could be reversed with the addition of copper but not iron or zinc to the cells. Switching cells from copper-deficient to copper-rich medium promoted the rapid degradation of CCS, which could be blocked by the proteosome inhibitors MG132 and lactacystin but not a cysteine protease inhibitor or inhibitors of the lysosomal degradation pathway. In addition, CCS degradation was slower in copper-deficient cells than in cells cultured in copper-rich medium. Together, these data show that copper regulates CCS expression by modulating its degradation by the 26 S proteosome and suggest a novel role for CCS in prioritizing the utilization of copper when it is scarce. PMID:12832419

Bertinato, Jesse; L'Abbé, Mary R

2003-06-27

428

Ion beam synthesis and investigation of nanocomposite multiferroics based on barium titanate with 3 d metal nanoparticles  

NASA Astrophysics Data System (ADS)

Samples of nanocomposite multiferroics have been synthesized by implantation of Co+, Fe+, and Ni+ ions with an energy of 40 keV into ferroelectric barium titanate plates to doses in the range (0.5-1.5) × 1017 ions/cm2. It has been found that nanoparticles of metallic iron, cobalt, or nickel are formed in the barium titanate layer subjected to ion bombardment. With an increase in the implantation dose, the implanted samples sequentially exhibit superparamagnetic, soft magnetic, and, finally, strong ferromagnetic properties at room temperature. The average sizes of ion-synthesized 3 d-metal nanoparticles vary in the range from 5 to 10 nm depending on the implantation dose. Investigation of the orientation dependence of the magnetic hysteresis loops has demonstrated that the samples show a uniaxial ("easy plane") magnetic anisotropy typical of thin granular magnetic films. Ferromagnetic BaTiO3: 3 d metal samples are characterized by a significant shift of the ferromagnetic resonance signal in an external electric field, as well as by a large (in magnitude) magnetodielectric effect at room temperature. These results indicate that there is a strong magnetoelectric coupling between the ferroelectric barium titanate matrix and ion-synthesized nanoparticles of magnetic metals.

Khalitov, N. I.; Lyadov, N. M.; Valeev, V. F.; Khaibullin, R. I.; Faizrakhmanov, I. A.; Dulov, E. N.; Tagirov, L. R.; Ibragimov, Sh. Z.; Prikhodko, K. E.; Roddatis, V. V.; Maksutoglu, M.; Kazan, S.; Mikailzade, F. A.

2013-06-01

429

Composition and structure measurements in an ionospheric barium cloud  

Microsoft Academic Search

A 48 kg barium payload was launched from Eglin Air Force Base, Florida on 12 December 1980 at 2311 GMT and detonated at 183.7 km. At 2342:50.25 GMT, a second rocket, instrumented with an ion mass spectrometer and pulsed plasma probes, was fired to traverse the barium cloud. Composition, ion density, and structure measurements were acquired up to 241.2 km

R. Narcisi; E. Tracinski; G. Federico; L. Wlodyka; P. Bench

1981-01-01

430

Ultrafine Barium Titanate Powders via Microemulsion Processing Routes  

Microsoft Academic Search

Three processing routes have been used to prepare barium titanate powders, namely conventional coprecipitation, single-microemulsion coprecipitation using diether oxalate as the precipitant, and double-microemulsion coprecipita- tion using oxalic acid as the precipitant. A single-phase perovskite barium titanate was obtained when the double- microemulsion-derived oxalate precursor was calcined for 2 h at a temperature of as low as 550°C, compared to

John Wang; Jiye Fang; Ser-Choon Ng; Leong-Ming Gan; Chwee-Har Chew; Xianbin Wang; Zexiang Shen

2004-01-01

431

The problem of heavy-element synthesis in barium stars  

NASA Astrophysics Data System (ADS)

An abundance analysis of the atmospheres of 33 stars, barium and normal G-K giants, is carried out using the differential model atmosphere method. Twenty barium stars which reveal a considerable enhancement of s-process elements exhibit slight depletions (about 0.2 dex) of Na, Mg, Mn, and Co; solar abundances for Si to Ni; and enhanced abundances (up to 1.5 dex) for Y to Eu. Mean parameters of the atmospheres are determined.

Zacs, L.

1991-07-01

432

Investigations on surface composition and microstructure of sintered barium titanate  

Microsoft Academic Search

The paper describes studies on surface atomic composition, microstructure and microarea elemental distribution in sintered\\u000a undoped as well as donor or acceptor doped polycrystalline barium titanate ceramics. The specimens examined are derived from\\u000a barium titanate powders synthesized by two different wet chemical procedures namely oxalate precursor route and gel-to-crystallite\\u000a conversion. The compositional analysis is carried out by backscattering spectrometry (BS)

Sanjiv Kumar; V. S. Raju; T. R. N. Kutty

2007-01-01

433

Coprecipitation of uranium and thorium with barium sulfate  

Microsoft Academic Search

The coprecipitation behaviour of uranium or thorium with barium sulfate is investigated from the variation of yields with uranium or thorium concentration, acid and acidity, and amount of sodium and\\/or potassium sulfate. Uranium or thorium in quantities less than 1.5 mg is quantitatively coprecipitated with barium (5.9 mg) sulfate when using an optimum conditions. The chemical form of uranium in

T. Kimura; Y. Kobayashi

1985-01-01

434

Iron and Mechanisms of Neurotoxicity  

PubMed Central

The accumulation of transition metals (e.g., copper, zinc, and iron) and the dysregulation of their metabolism are a hallmark in the pathogenesis of several neurodegenerative diseases. This paper will be focused on the mechanism of neurotoxicity mediated by iron. This metal progressively accumulates in the brain both during normal aging and neurodegenerative processes. High iron concentrations in the brain have been consistently observed in Alzheimer's (AD) and Parkinson's (PD) diseases. In this connection, metalloneurobiology has become extremely important in establishing the role of iron in the onset and progression of neurodegenerative diseases. Neurons have developed several protective mechanisms against oxidative stress, among them, the activation of cellular signaling pathways. The final response will depend on the identity, intensity, and persistence of the oxidative insult. The characterization of the mechanisms mediating the effects of iron-induced increase in neuronal dysfunction and death is central to understanding the pathology of a number of neurodegenerative disorders.

Salvador, Gabriela A.; Uranga, Romina M.; Giusto, Norma M.

2011-01-01

435

Microbial iron management mechanisms in extremely acidic environments: comparative genomics evidence for diversity and versatility  

Microsoft Academic Search

BACKGROUND: Iron is an essential nutrient but can be toxic at high intracellular concentrations and organisms have evolved tightly regulated mechanisms for iron uptake and homeostasis. Information on iron management mechanisms is available for organisms living at circumneutral pH. However, very little is known about how acidophilic bacteria, especially those used for industrial copper bioleaching, cope with environmental iron loads

Héctor Osorio; Verónica Martínez; Pamela A Nieto; David S Holmes; Raquel Quatrini

2008-01-01

436

Role of corrosion inhibiting pigments on the electrochemical kinetics of a copper-containing aluminum alloy  

SciTech Connect

The electrochemical polarization behavior of the copper-containing Al 2024-T3 alloy in deaerated 0.01 M NaCl saturated with a number of solid inhibitors demonstrates that one of the compounds examined, barium metaborate, exhibits an inhibiting power in excess of that of zinc chromate. Electrochemical polarization of a synthetic {theta}-phase CuAl{sub 2} intermetallic in aerated 0.01 M NaCl with and without the presence of the barium metaborate and zinc chromate inhibitors has also been examined.

Kendig, M.; Cunningham, M.; Jeanjaquet, S.; Hardwick, D. [Rockwell Science Center, Thousand Oaks, CA (United States)

1997-11-01

437

Barium abundance in red giants of NGC 6752. Non-local thermodynamic equilibrium and three-dimensional effects  

NASA Astrophysics Data System (ADS)

Aims: We study the effects related to departures from non-local thermodynamic equilibrium (NLTE) and homogeneity in the atmospheres of red giant stars, to assess their influence on the formation of Ba II lines. We estimate the impact of these effects on the barium abundance determinations for 20 red giants in Galactic globular cluster NGC 6752. Methods: One-dimensional (1D) local thermodynamic equilibrium (LTE) and 1D NLTE barium abundances were derived using classical 1D ATLAS9 stellar model atmospheres. The three-dimensional (3D) LTE abundances were obtained for 8 red giants on the lower RGB, by adjusting their 1D LTE abundances using 3D-1D abundance corrections, i.e., the differences between the abundances obtained from the same spectral line using the 3D hydrodynamical and classical 1D stellar model atmospheres. The 3D-1D abundance corrections were obtained in a strictly differential way using the 3D hydrodynamical and classical 1D codes CO5BOLD and LHD. Both codes utilized identical stellar atmospheric parameters, opacities, and equation of state. Results: The mean 1D barium-to-iron abundance ratios derived for 20 giants are ?[Ba/Fe]?1D LTE = 0.24 ± 0.05(stat.) ± 0.08(sys.) and ?[Ba/Fe]?1D NLTE = 0.05 ± 0.06(stat.) ± 0.08(sys.). The 3D-1D abundance correction obtained for 8 giants is small (~+0.05 dex), thus leads to only minor adjustment when applied to the mean 1D NLTE barium-to-iron abundance ratio for the 20 giants, ?[Ba/Fe]?3D + NLTE = 0.10 ± 0.06(stat.) ± 0.10(sys.). The intrinsic abundance spread between the individual cluster stars is small and can be explained in terms of uncertainties in the abundance determinations. Conclusions: Deviations from LTE play an important role in the formation of barium lines in the atmospheres of red giants studied here. The role of 3D hydrodynamical effects should not be dismissed either, even if the obtained 3D-1D abundance corrections are small. This result is a consequence of subtle fine-tuning of individual contributions from horizontal temperature fluctuations and differences between the average temperature profiles in the 3D and 1D model atmospheres: owing to the comparable size and opposite sign, their contributions nearly cancel each other. This fine-tuning is characteristic of the particular set of atmospheric parameters and the element investigated, hence should not necessarily be a general property of spectral line formation in the atmospheres of red giant stars.

Dobrovolskas, V.; Ku?inskas, A.; Andrievsky, S. M.; Korotin, S. A.; Mishenina, T. V.; Bonifacio, P.; Ludwig, H.-G.; Caffau, E.

2012-04-01

438

Gastrointestinal tract labeling for MDCT of abdomen: Comparison of low density barium and low density barium in combination with water  

Microsoft Academic Search

The purpose of the study was to compare the quality of stomach and small bowel marking\\/labeling using 1,350 ml of low-density\\u000a barium alone (VoLumen) with 900 ml of low-density barium and 450 ml of water for 16-MDCT scans of the abdomen and pelvis and\\u000a assess cost benefits with the two protocols. In this IRB approved study, 80 consecutive patients scheduled for routine CECT

Kavita Gulati; Zarine K. Shah; Nisha Sainani; Raul Uppot; Dushyant V. Sahani

2008-01-01

439

The metalloreductase FreB is involved in adaptation of Aspergillus fumigatus to iron starvation  

PubMed Central

Aspergillus fumigatus employs two high affinity iron uptake mechanisms, siderophore mediated iron uptake and reductive iron assimilation (RIA). The A. fumigatus genome encodes 15 putative metalloreductases (MR) but the ferrireductases involved in RIA remained elusive so far. Expression of the MR FreB was found to be transcriptionally repressed by iron via SreA, a repressor of iron acquisition during iron sufficiency, indicating a role in iron metabolism. FreB-inactivation by gene deletion was phenotypically largely inconspicuous unless combined with inactivation of the siderophore system, which then decreased growth rate, surface ferrireductase activity and oxidative stress resistance during iron starvation. This study also revealed that loss of copper-independent siderophore-mediated iron uptake increases sensitivity of A. fumigatus to copper starvation due to copper-dependence of RIA.

Blatzer, Michael; Binder, Ulrike; Haas, Hubertus

2011-01-01

440