UK PubMed Central (United Kingdom)

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

Science.gov (United States)

Electrically triggered action potentials in the giant alga Chara corallina are associated with a transient rise in the concentration of free Ca2+ in the cytoplasm (Ca2+cyt). The present measurements of Ca2+cyt during membrane excitation show that stimulating pulses of low magnitude (subthreshold pulse) had no perceivable effect on Ca2+cyt. When the strength of a pulse exceeded a narrow threshold (suprathreshold pulse) it evoked the full extent of the Ca2+cyt elevation. This suggests an all-or-none mechanism for Ca2+ mobilization. A transient calcium rise could also be induced by one subthreshold pulse if it was after another subthreshold pulse of the same kind after a suitable interval, i.e., not closer than a few 100 ms and not longer than a few seconds. This dependency of Ca2+ mobilization on single and double pulses can be simulated by a model in which a second messenger is produced in a voltage-dependent manner. This second ...

British Library Electronic Table of Contents (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

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

DEFF Research Database (Denmark)

ATPase, endoplasmic reticulum, calcium, ischaemia

UK PubMed Central (United Kingdom)

The second messenger signaling molecule bis-(3′-5′)-cyclic dimeric guanosine monophosphate (c-di-GMP) regulates many processes in bacteria, including motility, pathogenesis,...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundMicroRNAs (miRNAs) are non-coding RNAs that regulate gene expression by binding to the messenger RNA (mRNA) of protein coding genes. They control gene expression by either...Full Text Available

UK PubMed Central (United Kingdom)

Proteins that metabolize or bind the nucleotide second messenger cyclic diguanylate regulate a wide variety of important processes in bacteria. These processes include motility, biofilm formation, cell...Full Text Available

UK PubMed Central (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

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

Science.gov (United States)

The effects of pH on the calcium phosphate phase, of Tris and of amino acids, such as aspartic acid, glutamic acid, and serine on hydroxyapatite formation and morphology, were studied in double diffusion experiments. In this system, hydroxyapatite was only formed when the pH was around 7.4 or higher for the duration of the reaction. A decrease in pH resulted in the transformation of hydroxyapatite to octacalcium phosphate. Amino acids and Tris or the buffering capacity of Tris have an effect on the morphology of the synthetic hydroxyapatite. The presence of the additive results in spheres consisting of needles, blades or plates depending on the reaction system. PMID:12175941

Energy Technology Data Exchange (ETDEWEB)

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

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

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

UK PubMed Central (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

The use of europium as a local structural probe allows the various phases appearing in the NaCaPO/sub 4/-Na/sub 3/Eu(PO/sub 4/)/sub 2/ and NaSrPO/sub 4/-Na/sub 3/Eu(PO/sub 4/)/sub 2/ systems to be detected. The broadening of the europium emission lines in going from the calcium to the strontium phases illustrates the ease of displacement of the PO/sub 4/ groups.

Energy Technology Data Exchange (ETDEWEB)

Central penetrating excisional wounds were made in the corneas of 12 rabbits and 10 trout. The scar tissue and the surrounding cornea were compared using a new method for assessing inorganic elements in the cornea: the scanning electron microscopy and energy dispersive analysis of x-ray (EDAX). Semiquantitative determination of inorganic elements within the range of atomic numbers 9-93 in the periodic system was performed, comparing the relative concentration of those elements in the scar tissue to the surrounding cornea. Results showed that calcium was the only element higher in the healing wound than in the surrounding cornea.

UK PubMed Central (United Kingdom)

An unusual S1-nuclease sensitive microsatellite (STMS) has been found in the single copy, rat polymeric immunoglobulin receptor gene (PIGR) terminal exon. In Fisher rats, elements within or beyond the...Full Text Available

Science.gov (United States)

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

KoreaScience (Korea)

Full Text Available

KoreaScience (Korea)

Full Text Available

KoreaScience (Korea)

Full Text Available

KoreaScience (Korea)

Full Text Available

Science.gov (United States)

PMID:11506019

UK PubMed Central (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

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

Science.gov (United States)

Three analogs of lidocaine (benzyl carbamyl, benzyl nitrile and methyl nitrile) were synthesized and examined for cardiovascular and central activity. The benzyl carbamyl analog was more potent than lidocaine in lowering blood pressure but possessed only slight local anesthetic, antiarrhythmic and CNS-depressant activity. At 40 mg/kg the benzyl nitrile derivative was superior to lidocaine in protecting against chloroform-induced arrhythmias. The methyl nitrile analog was less active than the benzyl nitrile analog in most parameters examined. The benzyl nitrile derivative and lidocaine had similar potencies on blood pressure depression, local anesthetic activity and ability to protect against calcium chloride-induced arrhythmias. Unlike the benzyl carbamyl derivative both lidocaine and the benzyl nitrile compounds appear to depress the cardiovascular system via a common mechanism. PMID:515167

Energy Technology Data Exchange (ETDEWEB)

Contents: recent trend of battery technologies; alkaline manganese battery with no mercury addition; high capacity zinc-air battery series for hearing aids; characteristics of vanadium-niobium-lithium rechargeable battery; high-energy density lithium-ion rechargeable battery; lithium polymer rechargeable battery: polymer gel electrolyte and electrode; high-capacity ni-cd battery sm120; high-capacity nickel-metal hydride battery; sealed-type batteries for electric vehicles; high-temperature-durable calcium-type battery for automobiles; sealed lead acid batteries for upss; solar cell power unit; solid oxide fuel cell (1); battery management system.

Energy Technology Data Exchange (ETDEWEB)

Epidemiologic studies suggest a weak link between occupational or residential exposure to extremely low frequency electromagnetic fields and cancer, especially tumors of the central nervous and hematopoietic systems. This report discusses these studies with reference to basic research on ELF EMF bioeffects relevant to cancer-promoting mechanisms. Many of the studies suggest a possible interaction of ELF EMF with the immune system, endocrine system, or growth-regulatory signals and morphogenic movements that involve calcium flux through cell membranes. Many bioeffects have been reported only with certain specific combinations of frequency, amplitude, and orientation of the EMF signal with respect to the geomagnetic field. The possibility of signal-specific effects raises a complication in dosimetry for both epidemiologic and experimental studies since ELF EMF effects may not be directly related to field ...

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

KoreaScience (Korea)

Full Text Available

Science.gov (United States)

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

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

The aim of this work is to develop an industrial process for the synthesis of an extrusible electrolyte polymer for lithium batteries. From literature data and precise specifications the high molar mass EO/OP copolymers synthesis by coordinative catalysis has been studied in order to reach a high productivity and to minimize the treatment steps. Two catalytic systems have been studied: the aluminium alkoxide-based Vandenberg-type catalysis and the calcium alcoholate amides catalysis. The first catalysis performed in solution gives excellent results. Its adaptation to silicon supported catalysis leads to a directly usable polymer in suspension but the productivity falls down and remains to be optimized. The calcium amide catalysis in heptane suspension generates acceptable productivities but also a too high proportion of low molar masses. Various approaches have been studied to minimize this proportion due to the presence of ...

Energy Technology Data Exchange (ETDEWEB)

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

British Library Electronic Table of Contents (United Kingdom)

Tungsten, in the form of tungstate, polymerizes with phosphate, and as extensive polymerization occurs, cellular phosphorylation and dephosphorylation reactions may be disrupted, resulting in negative effects on cellular functions. A series of studies were conducted to evaluate the effect of tungsten on several phosphate-dependent intracellular functions, including energy cycling (ATP), regulation of enzyme activity (cytosolic protein tyrosine kinase [cytPTK] and tyrosine phosphatase), and intracellular secondary messengers (cyclic adenosine monophosphate [cAMP]). Rat noncancerous hepatocyte (Clone-9), rat cancerous hepatocyte (H4IIE), and human cancerous hepatocyte (HepG2) cells were exposed to 1-1000 mg/l tungsten (in the form of sodium tungstate) for 24 h, lysed, and analyzed for the ab...

CERN Document Server

Synthesis of protein molecules in a cell are carried out by ribosomes. A ribosome can be regarded as a molecular motor which utilizes the input chemical energy to move on a messenger RNA (mRNA) track that also serves as a template for the polymerization of the corresponding protein. The forward movement, however, is characterized by an alternating sequence of translocation and pause. Using a quantitative model, which captures the mechanochemical cycle of an individual ribosome, we derive an {\\it exact} analytical expression for the distribution of its dwell times at the successive positions on the mRNA track. Inverse of the average dwell time satisfies a ``Michaelis-Menten-like'' equation and is consistent with the general formula for the average velocity of a molecular motor with an unbranched mechano-chemical cycle. Extending this formula appropriately, we also derive the exact force-velocity relation for a ribosome. Often many ribosomes simultaneously move on ...

CERN Document Server

This paper presents a review of the history, motivation and current status of high energy neutrino telescopes. Many years after these detectors were first conceived, the operation of kilometer-cubed scale detectors is finally on the horizon at both the South Pole and in the Mediterranean Sea. These new detectors will perhaps provide us the first view of high energy astrophysical objects with a new messenger particle and provide us with our first real glimpse of the distant universe at energies above those accessible by gamma-ray instruments. Some of the topics that can be addressed by these new instruments include the origin of cosmic rays, the nature of dark matter, and the mechanisms at work in high energy astrophysical objects such as gamma-ray bursts, active galactic nuclei, pulsar wind nebula and supernova remnants.

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

Tumor necrosis factor alpha (TNF-alpha) and interleukin-1 (IL-1) have been shown to stimulate bone resorption in vitro. We have now investigated whether these cytokines also cause a similar action when administered in vivo. This was made possible by the adaptation of a newly developed technique that enables the continual assessment of bone resorption in vivo in mice by measuring urinary excretion of {sup 3}H from ({sup 3}H)tetracycline-prelabeled animals. Experiments using maneuvers known to influence bone resorption, such as a change in dietary calcium or administration of parathyroid hormone or dichloromethylenebisphosphonate, indicate that the technique is reliable and sensitive in mice. Daily intravenous administration of either recombinant human or recombinant murine TNF-alpha, as well as subcutaneous administration of recombinant human IL-1 alpha, were found to stimulate bone resorption in a dose-dependent manner. The effect was maximal within 2 days. Thus, ...

UK PubMed Central (United Kingdom)

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

International Nuclear Information System (INIS)

... calcium 47 combustion dry ashing high temperature labelled compounds lead

British Library Electronic Table of Contents (United Kingdom)

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

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

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

Science.gov (United States)

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

UK PubMed Central (United Kingdom)

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

International Nuclear Information System (INIS)

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

CERN Document Server

Regulatory genes called small RNAs (sRNAs) are known to play critical roles in cellular responses to changing environments. For several sRNAs, regulation is effected by coupled stoichiometric degradation with messenger RNAs (mRNAs). The nonlinearity inherent in this regulatory scheme indicates that exact analytical solutions for the corresponding stochastic models are intractable. Here, we present a variational approach to analyze a well-studied stochastic model for regulation by sRNAs via coupled degradation. The proposed approach is efficient and provides accurate estimates of mean mRNA levels as well as higher order terms. Results from the variational ansatz are in excellent agreement with data from stochastic simulations for a wide range of parameters, including regions of parameter space where mean-field approaches break down. The proposed approach can be applied to quantitatively model stochastic gene expression in complex regulatory networks.

CERN Document Server

Gamma-ray burst (GRB) is one of the candidates of high-energy cosmic-ray acceleration sites. They may be also ultra-high-energy (above 3 EeV) cosmic-ray (UHECR) sources. In this paper, we discuss possibilities and implications of high-energy cosmic-ray acceleration in GRBs. (1) First, we show that not only protons but also heavier nuclei can be accelerated up to ultra-high energies in both usual high-luminosity (HL) and low-luminosity (LL) GRBs by using the Geant4. LL GRBs may also make a significant contribution to the observed UHECR flux if they form a distinct population, and we investigate cosmic-ray acceleration in LL GRBs in detail. (2) Second, we discuss implications of the GRB-UHECR hypothesis (and Hypernova-UHECR hypothesis) to cosmic-ray astronomy. HL GRBs and LL GRBs will lead to different source number densities as UHECR sources, so that the determination of the number density of UHECR sources and strength of the mean extragalactic magnetic field (EGMF) will give us useful ...

Energy Technology Data Exchange (ETDEWEB)

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

British Library Electronic Table of Contents (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

A membrane process utilizing dialysis and selective complexation by water-soluble polymers has been developed. This process, termed affinity dialysis, has been shown to be selectively extract and concentrate both cations and anions in a manner similar to ion exchange or solvent extraction. The selective removal of calcium from sodium with selectivity of about 30, removal of chromate ion from dilute streams, and separation of transition metal ions such as Cu/Fe and Cu/Zn have all been successfully demonstrated. Effects of different polymers, polymer concentration, temperature, and flow rates have been studied. The effect of increased polymer concentration is to increase product concentration if appropriate changes in feed, polymer solution, and strip flow rates are made. A continuous polymer solution recycle and regeneration system has been constructed and operated with Cu/Zn and chromate/chloride feed streams. Removal of over 95% of the desired ...

UK PubMed Central (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

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

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

DEFF Research Database (Denmark)

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

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

International Science & Technology Center (ISTC)

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

DEFF Research Database (Denmark)

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

Science.gov (United States)

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

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

The neuronal nicotinic acetylcholine receptor {alpha}7 subunit is a member of a family of ligand-gated ion channels, and is the only subunit know to bind {alpha}-bungarotoxin in mammalian brain. {alpha}-Bungarotoxin binding sites are known to be more abundant in the hippocampus of mouse strains that are particularly sensitive to nicotine-induced seizures. The {alpha}7 receptor is highly permeable to calcium, which could suggest a role in synaptic plasticity in the nervous system. Auditory gating deficiency, an abnormal response to a second auditory stimulus, is characteristic of schizophrenia. Mouse strains that exhibit a similar gating deficit have reduced hippocampal expression of the {alpha}7 subunit. We have cloned and sequenced the full length cDNA for the mouse {alpha}7 gene (Acra-7) and characterized its gene structure. The murine {alpha}7 shares amino acid identity of 99% and 93% with the rat and human {alpha}7 subunits, respectively. ...

Energy Technology Data Exchange (ETDEWEB)

The authors have localized and characterized 2-125I-iodomelatonin binding sites in the chicken brain using in vitro quantitative autoradiography. Binding sites were widely distributed throughout the chicken brain, predominantly in regions associated with the visual system. The specific binding of 2-125I-iodomelatonin to discrete chicken brain areas was found to be saturable, reversible, and of high affinity. The specific binding of 2-125I-iodomelatonin (75 pm) was quantitated for 40 identifiable brain regions. Eight brain regions were chosen for binding characterization and pharmacological analysis: optic tectum, Edinger-Westphal nucleus, oculomotor nucleus, nucleus rotundus, ventral supraoptic decussation, ventrolateral geniculate nucleus, neostriatum, and ectostriatum. These regions showed no rostral-caudal gradient in 2-125I-iodomelatonin specific binding, and saturation analysis revealed a single class of high-affinity sites with KD values in the range of 33-48 ...

Energy Technology Data Exchange (ETDEWEB)

ICP emission analyses are prone to errors due to changes in power level, nebulization rate, plasma temperature, and sample matrix. As a result, accurate analyses of complex samples often require frequent bracketing with matrix matched standards. Information needed to track and correct the matrix errors is contained in the emission spectrum. But most commercial software packages use only the analyte line emission to determine concentrations. Changes in plasma temperature and the nebulization rate are reflected by changes in the hydrogen line widths, the oxygen emission, and neutral ion line ratios. Argon and off-line emissions provide a measure to correct the power level and the background scattering occurring in the polychromator. The authors` studies indicated that changes in the intensity of the Ar 404.4 nm line readily flag most matrix and plasma condition modifications. Carbon lines can be used to monitor the impact of organics on the analyses and calcium and ...

International Nuclear Information System (INIS)

Full text: Chemical-technology approaches allowing to intensification the prevention processes of gas hydrates formation at motion of gas-liquid stream of natural gas in system natural gas well - gas wire have been worked up. Technological regimes of treatment of gas stream have been determined. Linear correlation dependences inhibitor electrolytes contained hydrated ions with different ion radii and charges of subgroups of alkali elements with one - type electron configuration were obtained. Important physico-chemical parameters of electrolytes have been determined: activity; coefficients of activity, viscosity, diffusion; density; heat capacity; heat conductivity; surface tension and freezing-point. The features of continuous influence of inhibitory factors on process of gas flow at low temperatures and relatively high pressure differences ?P have been studied by using of technological installation modulating the system natural gas well - gas ...

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

British Library Electronic Table of Contents (United Kingdom)

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

Environmental Research Database

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

British Library Electronic Table of Contents (United Kingdom)

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

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

Purpose : To detect differentially expressed genes in the patients with uterine cervical cancer during the radiation therapy. Materials and Methods : In patients with biopsy proven uterine cervical cancer, we took a tumor tissue just before radiation therapy and at 40 minutes after external irradiation of 1.8 Gy. Total RNAs isolated from non-irradiated and irradiated tumor tissue samples were analyzed using the differential-display reverse transcription-polymerase chain reaction (DDRT-PCR). Complementary DNA (cDNA) fragments corresponding to differentially expressed messenger RNAs(mRNAs) were eluted, and cloned. The differential expression of the corresponding mRNAs was confirmed by reverse northern blot. Differentially expressed cDNA bands were sequenced. Nucleotide sequence data were analyzed in the Gene Bank and EMBL databases via the BLAST network server to identify homologies to known genes or cDNA fragments. Expression pattern of down-regulated clone was ...

Science.gov (United States)

The natriuretic peptides are considered to be cardioprotective; however, their receptors have not been identified in human myocardium using radiolabeled analogs. Dendroaspis natriuretic peptide (DNP) has been recently identified as a new member of this peptide family and is thought to be less susceptible to enzymatic degradation. Therefore, we have developed the novel radiolabeled analog [125I]-DNP and used this to localize high-affinity (K(D)=0.2 nmol/L), saturable, specific binding sites in adult human heart (n=6) and coronary artery (n=8). In competition binding experiments, atrial natriuretic peptide and brain type natriuretic peptide had greater affinity for [125I]-DNP binding sites than C-type natriuretic peptide and the natriuretic peptide receptor (NPR)-C ligand, cANF. This rank order of potency suggested binding of [125I]-DNP was specific to NPR-A. Messenger RNA encoding NPR-A was identified in left ventricle and coronary artery smooth muscle, and ...

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

International Nuclear Information System (INIS)

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

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

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

UK PubMed Central (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

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

Science.gov (United States)

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

CERN Document Server

The Delft Systems Approach

International Nuclear Information System (INIS)

The suitability of calcium silicate bricks (CSBs) for the retrospective measurement of gamma dose using luminescence techniques has been investigated. Bricks of this type are distinguished from fired clay bricks by containing negligible clay and requiring comparatively low temperature treatment during manufacture. They have been used widely in the construction f buildings in the Former Soviet Union since the 1970s but hitherto have not been used for retrospective dosimetry measurements. A procedure based on the se of the 210 deg. C thermoluminescence (TL) peak of quartz was tested with granular quartz extracted from three types of CSB, one of which had been taken from a settlement downwind of Chernobyl. The degree to which the residual geological TL signal within the temperature range of the 210 deg. C L peak had been reduced during manufacture varied with brick type; the levels of residual TL corresponded, in the samples tested, to absorbed doses n the range ...

CERN Document Server

Calcium (Ca) plays an important role in regulating various cellular processes. In a variety of cell types, Ca signaling occurs within microdomains where channels deliver localized pulses of Ca which activate a nearby collection of Ca-sensitive receptors. The small number of channels involved ensures that the signaling process is stochastic. The aggregate response of several thousand of these microdomains yields a whole-cell response which dictates the cell behavior. Here, we study analytically the statistical properties of a population of these microdomains in response to a trigger signal. We apply these results to understand the relationship between Ca influx and Ca release in cardiac cells. In this context, we use a first passage time approach to show analytically how Ca release in the whole cell depends on the single channel kinetics of Ca channels and the properties of microdomains. Using these results, we explain the underlying mechanism for the graded ...

CERN Document Server

There is increasing concern among the dental community regarding the damage caused to teeth by the acids in soft drinks. Enamel dissolution in acidic solution can be reduced by addition of calcium and/or phosphate salts to increase the degree of saturation with respect to hydroxyapatite (DS sub H sub A), or by an increase in pH. In soft drinks, however, both of these approaches are associated with a reduced taste quality. The separate effects of each parameter are not known. In the work presented here, enamel dissolution was studied in citric acid solutions with compositions typical of soft drinks. Nanoindentation and atomic force microscopy (AFM) were used to investigate very early stages of enamel dissolution, with typical exposure times of 30-600 s. Preliminary investigations of the application of SIMS, ESEM and XPS to enamel dissolution studies are also reported. The individual effects of DS sub H sub A , pH and calcium and phosphate ...

Energy Technology Data Exchange (ETDEWEB)

The Korea Atomic Energy Research Institute has launched a decommissioning program of uranium conversion plant. One of the important tasks in the decommissioning program is the treatment of the sludge, which was generated during operation and stored in the two ponds of the lagoon. The treatment requires the volume reduction of lagoon sludges for the low cost of the program and the conversion of the chemical forms, including uranium, for the acceptance at the final disposal site. The physical properties, such as densities, were measured and chemical compositions and radiological properties were analyzed. The denitration was a candidate process which would satisfy the requirements for sludge treatment, and the characteristics of thermal decomposition and dissolution with water were analyzed. The main compounds of the sludge were ammonium and sodium nitrate from conversion plant and calcium nitrate, calcium carbonate from Ca precipitation and ...

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence analysis (XFA) was used in the determination of the contents of metal residues in dosing plates for coin minting. XFA was also used for the determination of the strontium/calcium ratio in bone samples of different animals with the aim to obtain information on the food composition of these animals. It was found that bones of different animals can be distinguished based on the Sr/Ca ratio. No significant differences in the Sr/Ca ratio were observed in human bones of individuals from different social groups. (author). 1 fig., 5 tabs., 4 refs.

International Nuclear Information System (INIS)

Results of monitoring milk and tap water in New York City are presented. The New York City sample is a monthly composite of pasteurized milk purchased daily at retail stores. The monthly "9"0Sr to calcium ratios for New York City since the inception of the sampling program in 1954 are presented. Samples of New York City tap water are taken daily, so that by the end of the month, approximately 100 liters have been collected. The available cesium-137 data expressed as the "1"3"7Cs to "9"0Sr ratio are also given.

International Nuclear Information System (INIS)

The problem of search for new materials for spectrally positioned laser sources, which is central for modern photonics, is discussed. The use of the stimulated Raman scattering effect in crystals offers a highly efficient way to the design of such sources. The recent results of investigations into this effect for a large number of various types of crystalline materials are presented. The most promising compounds, as regards the realisation of different laser operation modes, are considered, including calcium, strontium, barium and lead molybdates and tungstates. Several examples of functioning efficient lasers based on novel materials exhibiting the stimulated Raman light scattering effect are given.

International Nuclear Information System (INIS)

In this study, Multi-Walled Carbon Nanotubes (MWCNTs) / Hydroxylapatite (HAp) composites were made to improve mechanical properties by using Spark Plasma Sintering (SPS) method. Slurry 6 mol of CaHPO4#centre dot#2H2O (DCPD), 4 mol calcium hydroxide and MWCNTs were mixed and sintered by using SPS at 5-120 MPa pressure, 1200-1250 deg. C and in vacuum or N2 atmosphere. The fracture toughness of sintered MWCNTs/HAp composites was increased.

Energy Technology Data Exchange (ETDEWEB)

Radian Corporation was contracted to investigate duct injection and ESP phenomena in a 1.7 MW pilot plant constructed for this test program. This study was an attempt to resolve problems found in previous studies and answer remaining questions for the technology using an approach which concentrates on the fundamental mechanisms of the process. The goal of the study was to obtain a better understanding of the basic physical and chemical phenomena that control: (1) the desulfurization of flue gas by calcium-based reagent, and (2) the coupling of an existing ESP particulate collection device to the duct injection process. Process economics are being studied by others. (VC)

Science.gov (United States)

Calcium stannate (CaSnO3) powders with the distorted perovskite structure have been synthesized by solid state and the sol-gel methods and their electrochemical performance was compared. The sol-gel CaSnO3 shows stable cycling performance with a reversible capacity of 430-440 mAh/g (0.005-1.0 V; 60 mA/g) up to 50 cycles. The role of preparatory conditions, morphology and cycling conditions (current density and potential window) on the anodic performance of the compounds are addressed.

Energy Technology Data Exchange (ETDEWEB)

Bone images obtained by single exposure dual energy subtraction with computed radiography, a new image processing method, were evaluated for the detectability of calcification in lung nodules in both phantom and clinical studies. In the phantom study, five simulated nodules containing known and uniformly distributed amounts of calcium hydroxide were placed in a human chest phantom and images were obtained the following five techniques: (1) conventional radiography (CXR), (2) low kV conventional radiography (Low), (3) Fuji computed radiography (FCR), (4) bone images with conventional singles exposure energy subtraction (ES) and (5) bone image with fine single exposure energy subtraction (FES). The detectability of calcification in the simulated nodules was evaluated by six radiologists using ROC analysis and two-way analysis of variance. In the clinical study, images of 42 lung nodules (21 calcified lung nodules and 21 non-calcified nodules), in which calcification ...

Energy Technology Data Exchange (ETDEWEB)

Exogenous adenosine 5{prime}-triphosphate (ATP) mobilized intracellular calcium in human carcinoma A43l cells and in Swiss 3T3 and 3T6 mouse fibroblasts by increasing inositol trisphosphate similar to well down growth factors (platelet-derived growth factor (PDGF), epidermal growth factor (EGF), bradykinin (BK), serum). Calcium mobilization was examined by video imaging of fura-2 fluorescence is single cells, following the radioactive isotope {sup 45}Ca, and monitoring the decrease in fluorescence of cells loaded with chlortetracycline. Uridine 5{prime}-triphosphate, but not other nucleotides, mimicked ATP. Single-cell analysis revealed synchronous responses in 10 sec to ATP, BK or serum, while PDGF (3T3) and EGF (A431) produced slower signals with significant cell-to-cell variation. PDGF desensitized 3T3 cells to ATP and BK added 100 sec later but ATP or BK did not desensitized to PDGF. Homologous desensitization was seen with all agonists. ...

Energy Technology Data Exchange (ETDEWEB)

Purpose: To visualise the vessel wall of the descending thoracic aorta using magnetic resonance imaging. To evaluate the diagnostic potential of tailored T{sub 1}-weighted sequences with contrast enhancement to assess systemic atherosclerotic disease. Methods: This study was performed on a clinical 1.5 Tesla scanner using a gradient strength of 30 mT/m and the phased array spine coil. A cadaver was examined to optimise a magnetic resonance imaging (MRI) protocol to evaluate atherosclerotic aortic wall disease. The acquired MR images were compared to gross specimens and histology. Subsequently seven patients who had undergone transesophageal ultrasound (TEU) with detailed assessment of the descending thoracic aorta were examined with MRI. The optimised protocol included untriggered and fat suppressed T{sub 2}-weighted turbo spin echo sequences and ECG-triggered and fat suppressed T{sub 1}-weighted spin echo sequences before and after iv administration of Gd-DTPA. ...

International Nuclear Information System (INIS)

For the treatment of dam waste water containing micro quantities of uranium, the so-called chemical precipitation method is conventionally used, that is, acidic sodium phosphate is added to it and so the uranium (UO_2"2"+) is removed in coprecipitation with the then occurring calcium phosphate (solid). The method, however, has several problems, such as the large space required and large quantities of sludge. For the pupose of eliminating such difficulties and removal and recovery of the uranium, development of the new uranium adsorption method was started. Of the many uranium adsorbents available, excellent ones were selected and then the continuous treatment test was made with small apparatus. Subsequently, the dam waste water uranium recovery facility was completed in 1983. (Mori, K.).

British Library Electronic Table of Contents (United Kingdom)

A novel microcapsule adsorbent for separation of uranium from phosphoric acid solutions was developed by immobilizing the di(2-ethylhexyl) phosphoric acid-?trioctyl phosphine oxide extractants in the polymeric matrix of calcium alginate. Physical characterization of the microcapsules was accomplished by scanning electron microscopy and thermogravimetric techniques. Equilibrium experiments revealed that both ion exchange and solvent extraction mechanisms were involved in the adsorption of Formula Not Shown ions, but the latter prevailed in a wider range of acid concentration. According to the results of kinetics study, at low acidity level, the rate controlling step was slow chemical reaction of Formula Not Shown ions with the microdroplets of extractant, whereas it changed to intraparticle...

Energy Technology Data Exchange (ETDEWEB)

Calcium sulfate dihydrate which is co-produced in the scrubbing of waste gases from bituminous coal power plants is employed in the underground road securing after recrystallization. Beta-sulfate semi hydrate is obtained from the dihydrate by recrystallisation and it is used as such or as a stiff mixture with additives as a stowing material. Particularly fly ash from coal combustion units, washery refuses and development rocks from coal mining or slags from the metallurgical industry can be used as additives. The compressive and the bending tensile strength of the stowing material can be adjusted by the water content in case beta sulfate semihydrate is used as such.

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

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

British Library Electronic Table of Contents (United Kingdom)

Dysregulation of intracellular Ca2+ homeostasis is associated with various pathological conditions and arrhythmogenesis of the heart. The objective of this study was to investigate the effects of an acute increase in intracellular Ca2+ concentration ([Ca2+]i) on the electrophysiology of ventricular myocytes by mimicking intracellular Ca2+ overload. The [Ca2+]i was clamped to either a controlled (65?100 nmol L?1) or increased (1 ?mol L?1) level. The transmembrane action potentials and ionic currents were recorded using whole-cell patch clamp techniques. We found that the acute increase in [Ca2+]i shortened the action potential duration, reduced the action potential amplitude, maximum depolarization velocity and resting membrane potential, caused delayed after-depolarizations (DADs), and tri...

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

Deferoxamine (DFA) (250 mg/kg), orally administered to rats, decreased Pu absorption from orally administered "2"3"8Pu(NO_3)_4 by about 1/3. The calcium salt of diethylenetriaminepentaacetic acid (Ca-DTPA), given orally 5 to 10 min after the Pu, increased absorption about four times. DFA given 10 min before the DTPA decreased the effect of the latter by a factor of two. Deferoxamine administration prior to inhalation treatment of man with DTPA may be one way to decrease possible DTPA-enhanced gut absorption of Pu.

Energy Technology Data Exchange (ETDEWEB)

The anticonvulsant drugs carbamazepine, phenobarbital, trimethadione, valproic acid and ethosuximide at pharmacologically relevant concentrations inhibit (/sup 3/H)diazepam binding to astrocytes in primary cultures but have much less effect on a corresponding preparation of neurons. Phenytoin as well as pentobarbital (which is not used chronically as an anticonvulsant) are equipotent in the two cell types. The convulsants picrotoxinin and pentylenetetrazol, the convulsant benzodiazepine RO 5-3663 and the two convulsant barbiturates DMBB and CHEB similarly inhibit diazepam binding to astrocytes but have little effect on neurons. On the basis of these findings it is suggested that these convulsants and anticonvulsants owe at least part of their effect to an interaction with the astrocytic benzodiazepine receptor, perhaps by interference with a calcium channel.

British Library Electronic Table of Contents (United Kingdom)

A new stem cell-scaffold construct based on poly-l-lactide (PLLA) nanofibers grafted with collagen (PLLA-COL) and cord blood-derived unrestricted somatic stem cells (USSC) were proposed to hold promising characteristics for bone tissue engineering. Fabricated nanofibers were characterized using SEM, ATR-FTIR, tensile and contact angle measurements. The capacity of PLLA, plasma-treated PLLA (PLLA-pl) and PLLA-COL scaffolds to support proliferation and osteogenic differentiation of USSC was evaluated using MTT assay and common osteogenic markers such as alkaline phosphatase (ALP) activity, calcium mineral deposition and bone-related genes. All three scaffolds showed nanofibrous and porous structure with suitable physical characteristics. Higher proliferation and viability of USSC was observe...

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

Hydrate addition at low temperature (or the HALT process) is a retrofit option for moderate SO/sub 2/ removal efficiency in coal burning utility plants. This dry FGD process involves injecting calcium based dry hydrate particles into flue gas ducting downstream of the air preheater where the flue gas temperature is typically in the range of 280-325/degree/F. This report is comprised of the conceptual scaleup design of the HALT process to a 180 MW and a 500 MW coal fired utility station followed by detailed capital and operating cost estimates. A cost sensitivity analysis of major process variables for the 500 MW unit is also included. 1 fig.

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

Bone mineral content as determined by computerized tomography (CT) and mechanical strength on axial loading were compared in 36 cadaveric femur specimens. Based on the CT measurements of density and area, the mass of a transverse slice of the femur was estimated. Highly significant correlations were demonstrated between strength and cancellous bone density. Even higher correlations were revealed when the bone masses of the proximal and distal femoral areas were calculated. Based on these findings, an equal distribution of the effective mass of the femur was postulated. This hypothesis was confirmed in an experimental rotational model. The CT attenuation values were also correlated to direct measurements of bone mineral content, i.e. calcium. Moreover, the strength of different metal implants, commonly used in femoral neck fractures, were assessed in cadaver specimens. 134 refs., 13 figs., 12 tabs.

British Library Electronic Table of Contents (United Kingdom)

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

CERN Document Server

The CMS RPC system overview

CERN Document Server

Handbook on decision support systems

CERN Document Server

Dynamic system identification

Energy Technology Data Exchange (ETDEWEB)

Field and laboratory work sponsored by the Gas Research Institute (GRI) and the Department of Energy (DOE) have shown that calcium-carbonate scale formation in waters produced with natural gas and oil can be prevented by injection of phosphonate inhibitor into the formation, even if the formation is sandstone without calcite binding material. Inhibitor squeeze jobs have been carried out on DOE's geopressured-geothermal Gladys MaCall brine-gas well and GRI's co-production wells in the Hitchcock field. Following the inhibitor squeeze on Gladys McCall, the well produced over five million barrels of water at a rate of approximately 30,000 BPD without calcium-carbonate scaling. Before the inhibitor squeeze, the well could not be produced above 15,000 BPD without significant scale formation. In the GRI brine-gas co-production field tests, inhibitor squeezes have been used to successfully prevent scaling. Laboratory work has been ...

Energy Technology Data Exchange (ETDEWEB)

Radiation inactivation and sedimentation equilibrium analysis were used to determine the functional and physical size of the chicken hepatic membrane receptor that binds N-acetylglucosamine-terminated glycoproteins. Purified plasma membranes from chicken liver were irradiated with high energy electrons and assayed for 125I-agalactoorosomucoid binding. Increasing the dose of ionizing radiation resulted in a monoexponential decay in binding activity due to a progressive loss of binding sites. The molecular mass of the chicken lectin, determined in situ by target analysis, was 69,000 +/- 9,000 Da. When the same irradiated membranes were solubilized in Brij 58 and assayed, the binding protein exhibited a target size of 62,000 +/- 4,000 Da; in Triton X-100, the functional size of the receptor was 85,000 +/- 10,000 Da. Sedimentation equilibrium measurements of the purified binding protein yielded a lower limit molecular weight of 79,000 +/- 7,000. However, the solubilized lectin was detected ...

Energy Technology Data Exchange (ETDEWEB)

Human senescence marker protein 30 (SMP30), which functions enzymatically as a lactonase, hydrolyzes various carbohydrate lactones. The penultimate step in vitamin-C biosynthesis is catalyzed by this enzyme in nonprimate mammals. It has also been implicated as an organophosphate hydrolase, with the ability to hydrolyze diisopropyl phosphofluoridate and other nerve agents. SMP30 was originally identified as an aging marker protein, whose expression decreased androgen independently in aging cells. SMP30 is also referred to as regucalcin and has been suggested to have functions in calcium homeostasis. The crystal structure of the human enzyme has been solved from X-ray diffraction data collected to a resolution of 1.4 {angstrom}. The protein has a 6-bladed {beta}-propeller fold, and it contains a single metal ion. Crystal structures have been solved with the metal site bound with either a Ca{sup 2+} or a Zn{sup 2+} atom. The catalytic role of the metal ion has been ...

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

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

KoreaScience (Korea)

Full Text Available

Science.gov (United States)

Not Available

Science.gov (United States)

Not Available

Energy Technology Data Exchange (ETDEWEB)

As part of a U.S. multi-regional pilot study conducted by the six Centers for Radiological Physics, 12-mm-diameter by 0.4-mm-thick CaSO/sub 4/:Dy Teflon-embedded discs were evaluated and used to measure patient entrance exposure on 60 average patients at 12 clinical centers. The discs were found to have adequate sensitivity, reproducibility and linearity up to 69.7 microC kg-1 (270 mR). The minimum measurable exposure was estimated as 0.4 microC kg-1 (1.5 mR). All responses were corrected for energy dependence, which varied +/- 20% from 1.7 to 6.5 mm Al half-value layer. Patient entrance exposure values ranged from 1.3 to 28 microC kg-1 (5 to 110 mR), with a median value of 5.2 microC kg-1 (20 mR). This value agreed with exposure measurements made on the chest radiography equipment using an ionization chamber and a phantom which simulated an average patient, and with published Nationwide Evaluation of X-Ray Trends (NEXT) data for the same period.

Science.gov (United States)

The ultimate compressive strength and modulus of elasticity of femoral cortical bone from adult geese (Anser anser), were determined by sex and by quadrant by compressing small right circular cylinders which were 2.4 mm in height and 0.8 mm in diameter. The average ultimate compressive strength was 183 +/- 29 MPa. The average modulus of elasticity was 13.2 +/- 3.4 GPa. The bending strength and bending modulus of elasticity were determined by a three point bend test on rectangular prisms which had the approximate dimensions 0.75 mm X 0.75 mm X 25 mm. The average bending strength was 263 +/- 44 MPa while the average bending modulus was 19.6 +/- 3.1 GPa. The calcium content was determined by atomic absorption spectrophotometry and no correlation was found with the mechanical properties. The histology of the cortical bone was examined both quantitatively and qualitatively. A unique type of Haversian bone is described. Goose bone was found to be morphologically similar ...

International Nuclear Information System (INIS)

The Yb"3"+-doped non-linear rare-earth calcium oxoborate crystals GdCa_4O (BO_3)_3 (GdCOB) and YCa_4O(BO_3)_3 (YCOB) were investigated by low-temperature absorption and selective excitation spectroscopy. The selective excitation and emission spectra revealed the spectral features of the main Yb"3"+ centre and the principal minority one in both crystals. The energy level schemes for these centres in both hosts, as well as structural assignments, were proposed. It was established that the minority centre, which represents about 10% of the total intensity and was assigned to Yb"3"+ in a Ca"2"+ site, is not a trap but an energy donor for the main centre. Common features of and differences between the vibronic structure of the two centres in GdCOB and YCOB are discussed. The existence of additional features in YCOB:Yb spectra is pointed out. (author)

International Nuclear Information System (INIS)

Quantitative bone scans were evaluated in 16 patients with osteoporosis and in a control group of 7 healthy subjects. Along with a detailed biochemical analysis of calcium-phosphorus metabolism and standartized reongenographs, a quantitative dynamic bone scintigraphy was performed according to the method proposed by the authors. The bone-accumulating factor K_b was determined on the base of mathematical analysis of the graph reflecting activity changes in bone tissue unit during the investigation, the blood-elimination factor K_h and kidney-elimination factor K_k. In addition the accumulation index AI (in %) was calculated as a relation between the activity in bone tissue unit, registered in 20 min interval, and the activity in soft tissues for the same time. Whereas the static gamma camera scintigraphy, made 3-4 hrs after injecting of the osteotrope radiopharmaceuticals, showed no specific changes in the patients examined, the method proposed realised higher K_b ...

International Nuclear Information System (INIS)

The CaWO_4:Ln"3"+ SiO_2 (Ln=Tb, Dy and Ho) nanoparticles were synthesized via a combustion process at 800 "oC, using citric acid as chelating agent and fuel, ammonium nitrate as fuel, boric acid as flux material and silica as supports. The persistent phosphor nanoparticles were characterized by X-ray diffraction (XRD), reflectance UV-vis and fluorescence spectroscopy (PL) and transmission electron microscopy (TEM) techniques. XRD patterns indicated that crystalline calcium tungstate with scheelite structure was produced. The reflectance UV-vis spectra showed the broad absorption band of WO_4"2"- groups and the PL spectra showed the WO_4"2"- wide excitation band, broad emission band of WO_4"2"- and characteristic emissions of Ln"3"+ ions. The average particle sizes were determined by TEM, which are about 50 nm.

Energy Technology Data Exchange (ETDEWEB)

We present the results of modeling intended to evaluate the feasibility of using neutrons from induced fission in highly enriched uranium (HEU) as a means of detecting clandestine HEU, even when it is embedded in absorbing surroundings, such as commercial cargo. We characterized radiation from induced fission in HEU, which consisted of delayed neutrons at all energies and prompt neutrons at energies above a threshold. We found that for the candidate detector and for the conditions we considered, a distinctive HEU signature should be detectable, given sufficient detector size, and should be robust over a range of cargo content. In the modeled scenario, an intense neutron source was used to induce fissions in a spherical shell of HEU. To absorb, scatter, and moderate the neutrons, we place one layer of simulated cargo between the source and target and an identical layer between the target and detector. The resulting neutrons and gamma rays are resolved in both time and energy to reveal ...

CERN Document Server

We have carried out studies on the rheological properties of regenerated silk fibroin (RSF) solution using video microscopy. The degummed silk from the Bombyx mori silkworm was used to prepare RSF solution by dissolving it in calcium nitrate tetrahydrate-methanol solvent. Measurements were carried out by tracking the position of an embedded micron-sized polystyrene bead within the RSF solution through video imaging. The time dependent mean squared displacement (MSD) of the bead in solution and hence, the complex shear modulus of this solution was calculated from the bead's position information. An optical tweezer was used to transport and locate the bead at any desired site within the micro-volume of the sample, to facilitate the subsequent free-bead video analysis. We present here the results of rheological measurements of the silk polymer network in solution over a frequency range, whose upper limit is the frame capture rate of our camera, at full resolution. By ...

Science.gov (United States)

Summaries are presented for those research contracts which expired between December 31, 1960 and December 31, 1981. Topics covered include: factors controlling distribution of fission products in biosphere, non-destructive methods of evaluating the U/sup 235/ and Pu content of irradiated fuel elements, studies of contamination in local marine resources, tracer studies of anemia, non-destructive analysis of irradiated fuel elements using a flux integrating monitor, mechanism of proteolysis of I/sup 131/-labeled fibrinogen, radiosensitivity of spermatogonia of Drosophila melel elements by gamma scanning, uptake and loss of radioactive material by marine bacteria, factors which influence the movement of radioactive strontium from soils to plants, biological concentration of fission products in mollusks from water, decay scheme of Tl/sup 210/, calcium balance in metabolic bone disease, development of radioactive drugs with special reference ...

Energy Technology Data Exchange (ETDEWEB)

A heat resistant nickel base alloy which is excellent in not only hot and cold workability but also high temperature strength properties and which also possesses satisfactory oxidation resistance. The nickel base alloy consists essentially of 0.001-0.15 percent carbon, 0.0005-0.05 percent calcium, 20.0-126.0 percent chromium, 4.7-9.4 percent cobalt, 5.0-16.0 percent molybdenum, 0.5-4.0 percent tungsten, with the total of molybdenum plus tungsten being from 9.0 to 16.5 percent, and the balance nickel and inevitable impurities. The alloy may further contain one selected from the group consisting of (1) 0.3-1.5 percent aluminum and 0.1-1.0 percent titanium, (2) 0.001-0.30 percent at least one of yttrium and rare earth elements, and (3) 0.001-1.0 percent at least one of niobium, vanadium and tantalum, whereby the aforementioned characteristics are further enhanced.

Energy Technology Data Exchange (ETDEWEB)

A method of grafting lignin-containing materials is now known which allows 1-phenylethylene or 4-methyl-2-oxy-3-oxopent-4-ene graft copolymers of wood to be quantitatively made. Graft copolymer is formed by conducting a free-radical polymerization with 1-phenylethene in nitrogen-saturated, organic or aqueous/organic solvent containing a lignin source, calcium chloride, and a hydroperoxide. Grafting changes solubility and surface properties of the wood. The lignin-containing materials grafted are unbleached wood pulps produced by chemical, thermal, and mechanical pulping. Grafting wood pulp produces a wood-reinforced, thermoplastic composite. When a particular plastic is to be blended with wood, we react the wood with the monomer used to make that plastic. This creates a hydrophobic surface of the plastic on the wood. This plastic coating can readily bond to the continuous plastic phase. The products of this grafting reaction are thermoplastic composites with ...

Energy Technology Data Exchange (ETDEWEB)

Two physical pre-treatment methods, particle size reduction by grinding and thermo-mechanical extrusion, were evaluated as alternatives to traditional biomass pretreatments for lignocellulosic ethanol. Commonly available agricultural co-products wheat bran and soybean hull were the model substrates. Extrusion led to higher reducing sugar yields as compared to grinding for wheat bran, but not in the case of soybean hulls. The best combination of extrusion screw speed and maximum barrel temperature were 7 Hz/150 C and 3.7 Hz/110 C. The use of a solvent mixture (sodium hydroxide, urea, and thiourea) and calcium chloride solution in combination with extrusion treatment did not lead to improvement in reducing sugar yield. However, extensive washing to get rid of solvents and enzymatic inhibitors improved the conversion efficiency substantially, resulting in total reducing sugar yields of 60-73% and 25-36%, respectively, for wheat bran and soybean hull. (author)

Energy Technology Data Exchange (ETDEWEB)

For high-efficiency coal gasification, investigations were given on effect of coal chars with different conversion rates on coal gasification reactivity. In coal gasification, reactivity of char after pyrolysis governs the efficiency. The reference char conversion in CO2 gasification of coal (weight loss) changes linearly in the initial stage of the reaction, but the reactivity declines as the end point is approached. Char surface area is as large as 400 m{sup 2}/g in the initial stage with the conversion at 20%, but it decreases in the final stage. This phenomenon relates closely with changes in pore size and crystalline structure. Change in the Raman value R which shows incompleteness of char graphite structure and amorphous carbon ratio suggests that an active portion with high reactivity is oxidized preferentially, and a portion with low reactivity remains finally. Minerals in coal are known to accelerate the gasification. However, their catalytic effect is related with chemical ...

Energy Technology Data Exchange (ETDEWEB)

Development was explained of non-phosphate detergent with zeolite (Z) and alpha-olefin sulfonate (AOS). 4A type Z was taken notice of as a builder to replace phosphate. In calcium ion trapping power, conventional sodium tripolyphosphate (STP) and Z are 158mgCaO/g and 150mg/g, respectively. However, because Z by the conventional method is large in crystal diameter, coagulates and adheres to matter to be washed, was newly developed fine Z, 0.9 {mu} m in primary grain diameter, which does not give abrasion nor occlusion to the washing machine, nor precipitate in the river. Because linear alkylbenzene sulfonate, combined with Z, is poorer in washing power than that, done with STP, was developed AOS, new non-phoshate use interfacial active detergent, which is excellent in all washing power, biodegradation speed and physical powder property. Improvement was variously made also in powdery detergent production technology. Though the non-phosphate detergent controlled water ...

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

Chemical-looping combustion is a promising technology for the combustion of gas or solid fuel with efficient use of energy and inherent separation of CO{sub 2}. Chemical-looping combustion of methane with calcium sulfate as a novel oxygen carrier was conducted in a laboratory scale fixed bed reactor. The effects of reaction temperature, gas flow rate, sample mass, and particle size on reduction reactions were investigated and an optimum operating condition was determined. The results show that this novel oxygen carrier has a high reduction reactivity and stability in a long-time reduction/oxidation test. The conversions of CH{sub 4} increased with a higher temperature, smaller gas flow rate, larger sample mass and smaller particle size. The suitable reaction temperature seems to be around 950 deg. C. Low temperatures lead to a low CH{sub 4} conversion, but a significant SO{sub 2} formation was observed at a higher temperature. The release of SO{sub 2}, CO, H{sub 2} ...

British Library Electronic Table of Contents (United Kingdom)

Genome-wide association studies have linked lung cancer risk with a region of chromosome 15q25.1 containing CHRNA3, CHRNA5 and CHRNB4 encoding a3, a5 and b4 subunits of nicotinic acetylcholine receptors (nAChR), respectively. One of the strongest associations was observed for a non-silent single-nucleotide polymorphism at codon 398 in CHRNA5. Here, we have used pharmacological (antagonists) or genetic (RNA interference) interventions to modulate the activity of CHRNA5 in non-transformed bronchial cells and in lung cancer cell lines. In both cell types, silencing CHRNA5 or inhibiting receptors containing nAChR a5 with a-conotoxin MII exerted a nicotine-like effect, with increased motility and invasiveness in vitro and increasing calcium influx. The effects on motility were enhanced by addit...

CERN Document Server

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

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

Since chlordecone (Kepone, CD) interferes with cardiac Na{sup +} ion translocases, we have studied CD effects on cardiac SR calcium pump activity. SR was isolated from heart ventricles of male Sprague-Dawley rats. Cardiac SR Ca{sup 2+}-ATPase, {sup 45}Ca-uptake and cAMP as well as calmodulin (CaM) dependent protein phosphorylation were measured. Ca{sup 2+}-ATPase was differentiated into low affinity and high affinity forms by measuring the activity using 50 and 0.7 {mu}M free Ca{sup 2+} respectively. CD in vitro inhibited {sup 45}Ca-uptake by SR in a concentration dependent manner with an IC50 value of 7 {mu}M and SR {sup 45}Ca-uptake was totally inhibited at 20-30 {mu}M CD. In agreement with this, both high affinity and low affinity Ca{sup 2+}-ATPases, which are involved in Ca{sup 2+} transport across membranes, were also inhibited by CD in a concentration dependent manner with IC50 values of 0.7 and 3.2 {mu}M respectively. Both Ca{sup 2+}-ATPase and {sup ...

Science.gov (United States)

The heterogeneous processing of atmospheric aerosols by reaction with nitrogen oxides results in the formation of particulate and adsorbed nitrates. The water content of these hygroscopic nitrate aerosols and consequently the nitrate ion concentration depend on relative humidity, which can impact the physicochemical properties of these aerosols. This report focuses on the 310 nm photolysis of aqueous sodium and calcium nitrate solutions at pH 4 over a wide concentration range of nitrate ion concentrations representative of atmospheric aerosols. In particular, the quantum yield (phi) of nitrite formation was measured and found to significantly decrease at high concentrations of nitrate for Ca(NO(3))(2). In particular, phi for Ca(NO(3))(2) was found to have a maximum value of (7.8 +/- 0.1) x 10(-3) for nitrate ion solution concentrations near one molal, with the smallest quantum yield for the highest concentration solution above 14 m nitrate ion, phi = (2.3 +/- 2.0) ...

CERN Document Server

Randomized Algorithms for Analysis and Control of Uncertain Systems

Science.gov (United States)

vibration Isolation system for the camera. ... to further define the response of the camera vibration isolation system. These ...

Science.gov (United States)

The Java Mission Evaluation Workstation System (JMEWS) is a collection of applications designed to

KoreaScience (Korea)

Full Text Available

CERN Document Server

Beam Diagnostic System for High Intensity Proton Linac at KAERI

Energy Technology Data Exchange (ETDEWEB)

This report presents the results of a study of the Japanese MLU magnetic-levitation (maglev) system. The development of the MLU system is reviewed, and the dynamic circuit model then is introduced and applied to the figure-eight-shaped null-flux coil suspension system. Three different types of figure-eight-shaped null-flux suspension systems are discussed in detail: (1) the figure-eight-shaped null-flux coil suspension system without cross-connection; (2) the combined suspension and guidance system; and (3) the combined propulsion, levitation, and guidance system. The electrodynamic-suspension maglev systems developed in Japan seem to be very promising and could result in a commercial application in the near future.

Science.gov (United States)

was deemed adequate and a cooling system designed utilizing the Melcor CP2-15- 10B thermoelectric module. Wall temperature achieved with this system was - 36 ...

Science.gov (United States)

Figure 23 presented detailed layout of the cooling system designed for the Mach 6 hypersonic- transport. The distribution system consisted of thin-wall ...

Science.gov (United States)

... BFS Breadth-First Search BIS Biological Immune System CCNA Cisco-Certified Network Associate CDIS Computer Defense Immune System ...

Energy Technology Data Exchange (ETDEWEB)

This paper presents an analysis of the applicability of alternative systems for electric vehicle (EV) heating and air conditioning (HVAC). The paper consists of two parts. The first part is a cooling and heating load calculation for electric vehicles. The second part is an evaluation of several systems that can provide the desired cooling and heating in EVs. These systems are ranked according to their overall weight The overall weight is calculated by adding the system weight and the weight of the battery necessary to provide energy for system operation. The system with the minimum overall weight is considered to be the best, because minimum vehicle weight decreases the energy required for propulsion, and therefore increases the vehicle range. Three systems are considered as the best choices for EV HVAC. These are, vapor compression, ice ...