WorldWideScience
2

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-04-15

3

Long-term monitoring of microleakage of dental cements by radiochemical diffusion  

International Nuclear Information System (INIS)

Radioactive "1"4C sucrose was found to be an ideal marker for microleakage because it did not penetrate tooth tissue, dental cement, or mounting resin. The main finding is that the adhesive cements--the glass-ionomer and polycarboxylate--are significantly more effective at preventing microleakage than are the traditional phosphate cements--silicate and zinc phosphate. The differences can be as high as two orders of magnitude. The adhesive cements provide almost perfect and reliable seals. By contrast, the nonadhesive cements are erratic sealants with most of the restorations leaking.

4

Ethoxylated Bisphenol Dimethacrylate-based Amorphous Calcium Phosphate Composites  

UK PubMed Central (United Kingdom)

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

2006-01-01

5

Proceedings of ARO Workshop Biostructures as Composite ...  

Science.gov (United States)

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

1990-03-01

6

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

British Library Electronic Table of Contents (United Kingdom)

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

2011-01-01

7

Well preflush fluid  

Energy Technology Data Exchange (ETDEWEB)

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

1992-01-21

8

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

UK PubMed Central (United Kingdom)

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

9

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

UK PubMed Central (United Kingdom)

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

1969-10-01

10

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

Energy Technology Data Exchange (ETDEWEB)

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

2004-11-01

11

NEW SLAG-BASED CONCRETES  

Environmental Research Database

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

1999-01-09

12

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

UK PubMed Central (United Kingdom)

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

1983-01-01

13

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

UK PubMed Central (United Kingdom)

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

2011-04-01

14

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

Science.gov (United States)

The aim of the current investigation was to study the effects of sevelamer hydrochloride (RenaGel) on serum phosphate, intact parathyroid hormone levels (iPTH), and lipid profiles in stable hemodialysis patients. Hemodialysis patients maintained on calcium containing phosphate binders were enrolled in this study. Following two weeks of washout of the phosphate binders, serum phosphate rose from 6.4 +/- 0.6 to 10.5 +/- 0.7 mg/dl (p <0.001). After 8 weeks of titration with sevelamer hydrochloride, serum phosphate fell by 4.5 +/- 0.3 to 6.3 +/- 0.7 mg/dl (p <0.0001). Serum calcium levels fell during washout (9.8 +/- 0.4 to 8.9 +/- 0.3 mg/dl, p <0.004) and were unaffected by sevelamer hydrochloride. Sevelamer hydrochloride administration was associated with a 23.0 +/- 3.1% fall in total cholesterol, a 35.9 +/- 3.0% fall in LDL ...

1998-12-01

15

Evaluation of chitosan/beta-tricalcium phosphate microspheres as a constituent to PMMA cement.  

Science.gov (United States)

Two methods, a traditional emulsion technique and a high voltage electrostatically modified encapsulation system, were used to fabricate degradable chitosan/beta -tricalcium phosphate (beta-TCP) microspheres. The two distinct kinds of microspheres both exhibited good sphericity and the beta-TCP was trapped well inside the chitosan gel. The microspheres prepared by high voltage electrostatic system exhibited a rougher outer surface and narrower size distribution. These microspheres were then used as an added constituent to commercially available PMMA bone cement. Four modified cement composites that were prepared with different composition ratios of the two kinds of chitosan/beta-TCP microspheres that were made from emulsion technique (C1P1 and C2P1) and from a process by a high voltage electrostatic system (EC1P1 and EC2P1) were compared with the PMMA cement (Pure P). The characteristics of these ...

2005-06-01

16

The influence of amino acids on the biomineralization of hydroxyapatite in gelatin.  

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

2002-08-30

17

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

International Nuclear Information System (INIS)

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

2003-07-01

18

Neutron shielding and constructional characteristics of a new type concrete and from borated clinker  

International Nuclear Information System (INIS)

A boron containing cement, which can be used as nuclear shielding material, is produced at pilot plant scale applying two different methods. In the first method, the raw mixture of a normal portland cement is mixed with pre-calcined colemanite, a calcium borate mineral, and clinkerized in a rotary kiln (borated-clinker). In the second method, the colemanite is mixed with an admixture, which contains mainly limestone and marl, and burnt in the rotary kiln to obtain a borated-lime composite. The borated-lime composite is then added to the normal portland cement clinker up to 2% B_2O_3 content for shielding purpose. The results have shown that the borated-clinker contained untolerable amount of free lime resulting in a decrease in compressive strength. The addition of the borated-lime composite to the normal portland cement clinker up to 1% B_2O_3 content did not alter the setting time ...

1994-11-07

19

Prospective observation of CAD/CAM titanium ceramic single crowns: A three-year follow up  

British Library Electronic Table of Contents (United Kingdom)

Statement of problem Computer-aided design/computer-aided manufacturing (CAD/CAM) titanium ceramic restorations were developed with the potential for replacing expensive, high noble metal ceramic restorations. However, there is a lack of information about the clinical performance of CAD/CAM titanium ceramic single crowns. Purpose The purpose of this study was to evaluate CAD/CAM titanium ceramic single crowns after 3 years in function. Material and methods A total of 41 crowns were fabricated for 21 patients. The titanium copings were CAD/CAM milled (Everest CAD/CAM system) with an even thickness of 0.5 mm, and low-fusing veneering porcelain (Vita Titanium Porcelain) was added incrementally. The crowns were cemented using zinc phosphate cement after confirming that there were no mechanical...

2009-01-01

20

Characteristics and formation mechanism of Permian Shanxi tight gas reservoir of Changbei gas field, Ordos Basin  

Energy Technology Data Exchange (ETDEWEB)

This paper discussed the lithological characteristics of tight gas reservoirs, including the diagenetic characteristics, diagenetic environment and diagenetic sequence. The link between porosity, the sedimentary environment, lithology, diagenesis and basin tectonics was examined in order to determine how tight reservoirs were formed. The study focused on the Changbei gas field located in Yishan Slope of the Ordos Basin in China. The main pay zone reservoir is the Upper Paleozoic Lower Permian Shanxi sandstone which lies at a depth of 2700-2950 m. This low porosity, low permeability tight gas reservoir was deposited in a coal bearing acid environment which controlled the diagenesis sequence. The early carbonate cement was not well developed because the original pore water was acidic with non saturated calcium carbonate. However, compaction has significantly reduced the original pore and pore volume. The acidic environment caused large amounts of ...

2010-07-01

21

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

International Nuclear Information System (INIS)

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

1983-09-01

22

Development of a pozzolanic pigment from red mud  

Energy Technology Data Exchange (ETDEWEB)

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

1997-10-01

23

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

Energy Technology Data Exchange (ETDEWEB)

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

2001-07-01

24

Development of non-phosphate detergent with zeolite and. alpha. -olefin sulfonate. Zeolite-AOS ni yoru senzai no murinka  

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 ...

1990-07-01

25

Development of value-added products from alumina industry mineral wastes using low-temperature-setting phosphate ceramics  

Energy Technology Data Exchange (ETDEWEB)

A room-temperature process for stabilizing mineral waste streams has been developed, based on acid-base reaction between MgO and H3PO4 or acid phosphate solution. The resulting waste form sets into a hard ceramic in a few hours. In this way, various alumina industry wastes, such as red mud and treated potliner waste, can be solidified into ceramics which can be used as structural materials in waste management and construction industry. Red mud ceramics made by this process were low-porosity materials ({approx}2 vol%) with a compression strength equal to portland cement concrete (4944 psi). Bonding mechanism appears to be result of reactions of boehmite, goethite, and bayerite with the acid solution, and also encapsulation of red mud particles in Mg phosphate matrix. Possible applications include liners for ponds and thickned tailings disposal, dikes for waste ponds, and grouts. Compatability problems arising at the ...

1996-01-01

26

The process for recovery of uranium from dam waste water  

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.).

27

WASTE TREATMENT AND DISPOSAL PROGRESS REPORT FOR JUNE AND JULY 1962  

Science.gov (United States)

9 9 simulated Purex waste oxides was investigated as a function of Na/sub 2/O, CaO and P/sub 2/O/sub 5/ content. All compositions lost some sulfate at 50 to 100 deg C above the softening point. In generai the volatility decreased with increase of either Na/ sub 2/O or CaO relative to P/sub 2/O/sub 5/, but no simple correlation Was indicated. Softening temperatures were lowered by inc ease in Na/sub 2/O vs CaO. Ceramic solids were obtained but no true glasses. Attempts to produce glasses by addition of varying combinations of Al/sub 2/O/sub 3/, PbO, BaO, and B/sub 2/O/ sub 3/ to simulated Pure x waste plus phosphite were unsuccessful. The use of 0.005 M Na/sub 2/C/O/sub 3/ to precipitate calcium from wastes containing up to 3 ppm of phosphate was demonstrated in four pilot plant runs and produced a decrease in the hardness of the waste leaving the clarifier. An inadvertent Sr/ sup 90/ and Cs/sup 137/ breakthrough ...

1962-12-19

28

Human tooth enamel dissolution in citric acid as a function of degree of saturation and pH  

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 ...

2002-01-01

29

Use of Eu/sup 3 +/ as an oxygen environment probe in alkali-alkaline earth-lanthanide phosphates with the. beta. -K/sub 2/SO/sub 4/ structure  

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.

1983-09-15

30

Selective detection of hexachromium ions by localized surface plasmon resonance measurements using gold nanoparticles/chitosan composite interfaces.  

Science.gov (United States)

Selective removal of hexavalent chromium ions from aqueous solutions using a chitosan/gold nanoparticles composite film was demonstrated. Localized surface plasmon resonance (LSPR) was used to measure the interface stability and detect the incorporation of chromium ions over time. The effects of pH, ethylenediaminetetraacetic acid (EDTA), and various foreign ions such as trivalent chromium, sodium, calcium, phosphate, sulfate and chloride on the adsorption of hexavalent chromium were investigated. PMID:19381379

2009-03-04

31

Influence of two changes in the composition of an acrylic bone cement on its handling, thermal, physical, and mechanical properties.  

Science.gov (United States)

This study is a contribution to the growing body of work on the influence of changes in the composition of an acrylic bone cement on various properties of the curing and cured material. The focus is on one commercially-available acrylic bone cement brand, Surgical Simplex P, and three variants of it and a series of properties, namely, setting time, maximum exotherm temperature, activation energy and frequency factor for the polymerization reaction, diffusion coefficient for the uptake of phosphate buffered saline, at 37 degrees C, ultimate compressive strength (UCS), plane-strain fracture toughness, fatigue life (under fully-reversed tension-compression stress), hardness (H) and elastic modulus (both determined using quasi-static nanoindentation), and the variation of the storage and loss moduli with frequency of the applied force in a dynamic nanoindentation test. It was found that (a) a 68% reduction in the volume of the ...

2007-05-05

32

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

International Nuclear Information System (INIS)

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

33

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

International Nuclear Information System (INIS)

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

1985-03-01

34

Coupled effects of the precipitation of secondary species on the mechanical behaviour and chemical degradation of concretes; Les effets couples de la precipitation d'especes secondaires sur le comportement mecanique et la degradation chimique des betons  

Energy Technology Data Exchange (ETDEWEB)

Sulfate attack of cement-based materials remains an important problem for the durability assessment of containers and disposal engineering barriers dedicated to the long-term storage of radioactive wastes since underground water which may reach these elements contains small quantities of sulfates (7-31 mmol/1). This work contributes to the study of sulfate-induced damage mechanisms, to their understanding and modelling. The experimental phases of this study aimed at the understanding of the different physico-chemical phenomena involved during an external sulfate attack at following their evolution and their impact on the transport and mechanical properties of the material. Leaching experiments in pure water and in a solution of sodium sulfate (with a sulfate content of 15 mmol/1), have been performed simultaneously on OPC paste (w/c 0,4)in order to allow a comparison of test results. The frequent analysis of the leachant has shown a consumption of sulfate ions by ...

2002-06-01

37

Outcome Evaluation of Ceramic Crowns Using Two Different Dental Cements  

Science.gov (United States)

Sensitivity to Dental Cements; Dental Crowns; Dental Three-unit Bridges

2011-08-02

38

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

International Nuclear Information System (INIS)

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

41

Chromium stabilization chemistry of paint removal wastes in Portland cement and blast furnace slag  

Energy Technology Data Exchange (ETDEWEB)

The use of cement based systems for solidification and stabilization of hazardous wastes has been proposed. The stabilization of Cr contaminated paint removal wastes in ordinary Portland cement and in a Portland cement and blast furnace slag matrix was investigated. A loading by volume of 75% waste and 25% cement (or cement + slag) was used. The expression of pore solution was utilized to determine the chemical environment encountered by the waste species in the cement matrix. The highly alkaline conditions of ordinary Portland cement determined the stability of the metal species, with Cr being highly soluble. The replacement of 25% of the Portland cement by blast furnace slag was found to decrease the [OH-] of the pore solution resulting in a decrease of the Cr concentration. For cement wastes forms ...

1995-12-31

43

Regulation and Function of Escherichia coli Sugar Efflux Transporter A (SetA) during Glucose-Phosphate Stress?  

UK PubMed Central (United Kingdom)

Accumulation of certain nonmetabolizable sugar-phosphates (including α-methyl glucoside-6-phosphate) in Escherichia coli is growth inhibitory and elicits the glucose-phosphate...Full Text Available

2011-01-01

44

Method of the cementing of material  

Energy Technology Data Exchange (ETDEWEB)

Invention relates to woodworking industry and concerns method of cementing of materials of foam plastic with duralumin, glued plywood, etc. Known methods of cementing of materials by effect of electromagnetic field of superhigh frequencies are unproductive and do not make it possible to cement parts on the plane. Target of invention - acceleration of process of cementing of planar, including of complex configuration, parts and assemblies from wood, foam plastic, duralumin, glued plywood and other materials. For this material is cemented under the effect of directed electromagnetic field of superhigh frequency in the range 01-50 GHz, the specific power of 0.5-15 W/cm3.

1990-10-30

45

Development of Material Properties for Slurry Infiltrated Fiber ...  

Science.gov (United States)

... Page 26 Ultimate compressive strength versus fly ash/cement limits 41 ... 222 El Ultimate compressive strength versus water/(cement + fly ash) 250 ...

1988-09-01

46

Cementless bipolar hemiarthroplasty in femoral neck fractures in elderly  

UK PubMed Central (United Kingdom)

Background:Cemented hip arthroplasty is an established treatment for femoral neck fracture in the mobile elderly. Cement pressurization raises intramedullary pressure and...Full Text Available

2011-05-01

47

Adhesive 'PED-B' for Cementing Plastics of Formula 57-40 to ...  

Science.gov (United States)

... Title : Adhesive 'PED-B' for Cementing Plastics of Formula 57-40 to the Surfaces of Contruction Units,. ... Glue PED-B is not explosive. ...

1964-08-20

48

Health-hazard evaluation report HETA 85-354-1872, Asarco, Denver, Colorado  

Science.gov (United States)

An evaluation was made of possible hazardous working conditions at the ASARCO Globe facility, Denver, Colorado. The facility was involved in the recovery of cadmium from baghouse dust, a waste byproduct of nonferrous smelters. A medical study of kidney function was conducted in 45 current or former cadmium production workers; results were compared to those for 35 hospital workers. Kidney abnormalities were more common and more severe in the cadmium workers than in the hospital workers. Abnormalities of proximal tubular function included reduced reabsorption of beta-2-microglobulin, retinol binding protein, calcium and phosphate. Glomerular dysfunction was evidenced as elevated serum creatinine. As length of exposure to cadmium increased, changes became more apparent in workers. No reversal of the conditions was noted in workers who had ceased to be exposed to cadmium some time before the study. The authors conclude that occupational ...

1988-02-01

49

Drying characteristics and nitrogen loss of biogas digestate during drying process  

Energy Technology Data Exchange (ETDEWEB)

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

2010-07-01

50

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

UK PubMed Central (United Kingdom)

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

2007-07-26

51

THE EFFECTS OF ONE MEGACYCLE ULTRASONIC ...  

Science.gov (United States)

... ULTRASONIC VIBRATION TO PORTLAND CEMENT-WATER PASTE REDUCES THE ULTIMATE COMPRESSIVE STRENGTH OF MORTARS ...

1959-09-09

55

Similarities and differences of microstructure and macro properties between portland and blended cement  

Energy Technology Data Exchange (ETDEWEB)

The relationship between microstructure and macro properties of different cementitious materials has been investigated. This study consists of the following tasks: using NMR and IR to better characterize the amorphous and poorly crystalline phases that occur in blended cements; characterizing the microstructure of the hydration products of modified Portland cement as a function of different percentages of pozzolan replacements by ESEM, SEM, and EDS; comparing the properties of blended cement pastes with a control group of normal Portland cements; and studying the engineering aspects of blended cement that are important for identifying and characterizing fundamental phenomena that are responsible for their durability. The overall influence of the nanoscale and microscale structure of blended and Portland cement on the properties of the resultant composite will be ...

1997-10-01

56

Analyses of uranium in some phosphate commercial products  

International Nuclear Information System (INIS)

The raw materials used in manufacturing of phosphate fertilizer products were derived from rocks. Rocks contain a remarkable of natural radioactivity. Uranium and phosphorous were originally initiated at the same time of the initiated rocks. The purpose of this research is to investigate solubility of uranium phosphate species at the phosphate fertilizer samples, samples including; raw phosphate material, single super phosphates (SSP) granules and powdered, triple super phosphates (TSP) and phosphogypsum samples were obtained from Abu-Zabal factory in Egypt. Solubility of uranium phosphate species was estimated. It was found that, less than half of the uranium phosphate species are soluble in water. The soluble uranium may be enter into the food chains by plant. Therefore, restriction should be done in order to limit ...

2004-02-24

57

Retardation of Bean Leaf Senescence by Benzyladenine and Its Influence on Phosphate Metabolism 1  

UK PubMed Central (United Kingdom)

The levels of glucose, sugar phosphates, and adenosine phosphates were determined in primary leaves of intact bean plants during normal senescence and compared to leaves in which senescence was delayed...Full Text Available

1970-10-01

58

Methane conversion process using phosphate-containing catalysts  

Energy Technology Data Exchange (ETDEWEB)

A process is described for covering methane to a higher order hydrocarbon comprising contacting a gaseous reactant consisting of methane with a phosphate-containing catalyst for a sufficient period of time and at an effective temperature to provide the phosphate-containing catalyst consisting essentially of the higher order hydrocarbon. The catalyst is represented by a formula.

1987-05-12

59

Isozymes of the Glycolytic Enzymes in Endosperm from Developing Castor Oil Seeds 1  

UK PubMed Central (United Kingdom)

Ion filtration chromatography on diethylaminoethyl-Sephadex A-25 has been used to separate two isozymes each of triose phosphate isomerase, glyceraldehyde 3-phosphate dehydrogenase, glycerate 3-phosphate...Full Text Available

1982-04-01

60

Disturbance of inorganic phosphate metabolism in diabetes mellitus: temporary therapeutic intervention trials  

UK PubMed Central (United Kingdom)

A paradoxical metabolic imbalance in inorganic phosphate occurs from the early onset of diabetes and may lead to a reduction of high energy phosphates and tissue hypoxia. These changes take place in...Full Text Available

61

National remediation program of radioactively contaminated sites in the Republic of Croatia  

Energy Technology Data Exchange (ETDEWEB)

The national remediation program in Croatia consists of three stages: (1) identification and characterization of radioactively contaminated sites; (2) preparing activities for restoration; and (3) physical restoration at selected (high-prioritized) sites. The program is coordinated by the APO and, in the first stage, performed by both national research institutes of Ruder Boskovi and Institute for Medical Research and Occupational Health. The program supervisors are Ministry of Health, Ministry of Economy (Department of Energy) and State Administration for Environmental Protection. There were more than thirty sites suspected to be radioactively contaminated in Croatia. They were classified into four contamination type groups: (1) dumps containing contaminated coal slag and ash; (2) dumps containing contaminated phosphates and phospho-gypsum resulting from fertilizers industry; (3) geothermal springs and gas/oil wells; and (4) sites containing natural radioactive ...

1995-12-31

62

Energy conservation potential of Portland cement particle size distribution control, Phase 2  

Energy Technology Data Exchange (ETDEWEB)

The main objectives of Phase 2 are to determine the feasibility of using cements with controlled particle size distributions (CPSD cements) in practical concrete applications, and to refine our estimates of the potential energy savings that may ensue from such use. The work in Phase 2 is divided into two main tasks, some parts of which will be carried out simultaneously: Task 1 will continue cement paste studies to optimize cement performance similar to those of Phase 1, but with particular emphasis on gypsum requirements, blended cements, and water-reducing admixtures. This task will also include preparation of sufficient CPSD cements for use in all Phase 2 work. Task 2 will be a comprehensive examination of the properties of concretes made with CPSD cements. This will include optimization of concrete mix designs to obtain the best possible ...

1983-01-01

63

Carbon tetrachloride-induced release of calcium from isolated hepatocytes  

International Nuclear Information System (INIS)

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

64

Iodination of glyceraldehyde 3-phosphate dehydrogenase  

UK PubMed Central (United Kingdom)

1. A high degree of homology in the positions of tyrosine residues in glyceraldehyde 3-phosphate dehydrogenase from lobster and pig muscle, and from yeast, prompted an examination of the reactivity...Full Text Available

1970-09-01

65

Preparation and evaluation of a novel glass-ionomer cement with antibacterial functions  

British Library Electronic Table of Contents (United Kingdom)

Objective.The objective of this study was to use the newly synthesized poly(quaternary ammonium salt) (PQAS)-containing polyacid to formulate the light-curable glass-ionomer cements and study the effect of the PQAS on the compressive strength and antibacterial activity of the formed cements.Materials and methods.The functional QAS and their constructed PQAS were synthesized, characterized and formulated into the experimental high-strength cements. Compressive strength (CS) and Streptococcus mutans viability were used to evaluate the mechanical strength and antibacterial activity of the cements. Fuji II LC cement was used as control. The specimens were conditioned in distilled water at 37 degrees C for 24 h prior to testing. The effects of the substitute chain length, loading as well as gra...

2011-01-01

66

Graft copolymers of methyl methacrylate and poly([R]-3-hydroxybutyrate) macromonomers as candidates for inclusion in acrylic bone cement formulations: Compression testing.  

Science.gov (United States)

Graft copolymers of methyl methacrylate and biodegradable, biocompatible bacterial poly([R]-3-hydroxybutyrate) (PHB) blocks were synthesized and evaluated as possible constituents in acrylic bone cements for use in orthopaedic applications. The copolymers were produced by conventional free radical copolymerization and incorporated in one commercially available acrylic bone cement brand, Antibiotic Simplex (AKZ). Cements with formulations containing 6.7 and 13.5 wt % of PMMA-graft-PHB were prepared. The morphology of the graft copolymer particles was suggested to influence the ability of the modified cement to be processed. Formulations containing more than about 20 wt % of the graft copolymer resulted in cement doughs that, both after first preparation and several hours later, were either sandy or soft spongy in texture and, thus, would be unacceptable for use in orthopaedic ...

2006-04-01

67

Isotope fractionations and radiocarbon ages of beach rock samples collected from the Nansei Islands, southwest of Japan  

International Nuclear Information System (INIS)

Beach rocks are observed frequently on the tropical and subtropical sandy beaches where they express thin beds dipping seaward at less than 15 degrees. They consist of beach sediments including fossil shells, fragments of corals, diatoms and other biocarbonates, and are well cemented within the inter-tidal zone with calcium carbonate originated in sea water. Therefore, they are not only good indicators which show the past sea level, but also provide good sample material for radiocarbon dating. The locations of beach rocks give us an optimum condition studying a carbon cycle between land and marine environment by analyzing their isotope fractionations. In order to estimate the origin of calcium carbonate which worked as an adhesive when beach rocks were formed and to estimate the formative ages of beach rocks, a total of 330 fossil corals, fossil shells and calcarenite or calcirdite samples were collected from 128 sites of ...

2004-10-25

68

Early Post-operative Periprosthetic Femur Fracture in the Presence of a Non-cemented Tapered Wedge Femoral Stem  

UK PubMed Central (United Kingdom)

Non-cemented femoral fixation in hip arthroplasty has become the standard of practice in the USA. However, recent literature has brought attention to an increasing incidence of periprosthetic femur...Full Text Available

2010-09-01

69

Uranium phosphates  

International Nuclear Information System (INIS)

Methods of preparation, stability in solutions and in the solid phase, composition of orthophosphate crystallohydrates and condensed uranyl- and uranium (4) phosphates, are considered. Structures of these compounds are discussed; it is shown that they are steric polymers with an uranylphosphate framework. The problem of phosphate-anion polymerization in the process of thermal decomposition is discussed. It is established that condensed uranyl polyphosphates are not stable during storage, capable of degradation, its degree increasing with the phosphate chain length and uranium content.

70

The harmful effect of phosphate in yellow cake on the TBP purification process  

International Nuclear Information System (INIS)

The harmful effect of phosphate in yellow cake on the TBP purification process and its removal methods are dealed with. The reason of more uranium loss in residue was analyzed. The harmful effect of phosphate on TBP extraction efficiency and operaton of extraction column was discussed. The limit value of uranium concentration in digestion solution was presented. For TBP purification process, the presence of phosphate in yellow cake does more harm than good. (authors)

2009-02-01

71

THE CONTENT OF ADENINE NUCLEOTIDES AND ...  

Science.gov (United States)

... Accession Number : AD0262144. Title : THE CONTENT OF ADENINE NUCLEOTIDES AND CREATINE PHOSPHATE IN BRAIN. ...

1961-05-01

72

Kinetics of chlorination of phosphates of actinides and fission elements in chloride melts. II. Zirconium phosphates  

Energy Technology Data Exchange (ETDEWEB)

The kinetics of the reaction of zirconium phosphates with carbon tetrachloride in sodium and potassium chloride melt as well as the effect of temperature, gas flow, solubility and weight of the solid phase of the phosphate, and stirring of the melt on the chlorination rate has been studied. The kinetic parameters of the reaction (rate constants, activation energy, etc.) have been calculated.

1987-07-01

73

Utilization of red mud from the Bayer process for producing Ferrari cements. Verwendung von Rotschlamm nach dem Bayer-Verfahren zur Herstellung von Ferrari-Zementen  

Energy Technology Data Exchange (ETDEWEB)

A report is given of investigations into the possibility of utilizing red mud from the Bayer process for producing Ferrari cements. On repeated burning at 1450deg C suitable mixtures of red mud with silica and lime form a clinker with a low free lime content from which Ferrari cement can be produced. The average 28-day compressive strengths of cements produced from this clinker are so encouraging that further investigations are appropriate. (orig.).

1989-11-01

74

KoderaUNEP_Uploaded web [Compatibility Mode  

Wastenet

complex -agriculture sector in a local community -blast furnace -cokes oven -cement kiln

75

Spatiotemporal intracellular calcium dynamics during cardiac alternans  

UK PubMed Central (United Kingdom)

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

2009-09-01

76

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

UK PubMed Central (United Kingdom)

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

2010-07-01

77

Role of plasma membrane calcium ATPase 2 in spinal cord pathology  

UK PubMed Central (United Kingdom)

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

2010-05-26

78

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

UK PubMed Central (United Kingdom)

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

2007-05-01

79

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

UK PubMed Central (United Kingdom)

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

2009-12-01

80

Calcium Requirements and Metabolism in Chinese-American Boys and Girls  

UK PubMed Central (United Kingdom)

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

2010-08-01

81

The influence of compound admixtures on the properties of high-content slag cement  

Energy Technology Data Exchange (ETDEWEB)

Based on the activation theory of alkali and sulfate, the influence of compound admixtures on the properties of high-content slag cement was studied by testing the strength, pore structure, hydrates, and microstructure, Test results show that compound admixtures can obviously improve the properties of high-content slag cement. The emphasis of the present research is two-fold: substituting gypsum with anhydrite and calcining gypsum. These both can improve early and later performance.

2000-01-01

82

Model analysis of an inter-industrial and inter-regional waste recycling system in Japan  

Energy Technology Data Exchange (ETDEWEB)

In this study, we investigate an inter-industrial and inter-regional recycling system for industrial waste by the cement industry in Japan. We develop a linear programming model that represents cement production processes and waste transportation of all cement factories in Japan. We simulate cost and CO{sub 2}-minimizing systems. The result implies that making waste transportation more efficient in cost is an effective means for CO{sub 2} reduction. (author)

2007-04-15

83

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

Energy Technology Data Exchange (ETDEWEB)

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

1983-02-01

84

Adsorption of phosphate from aqueous solution using activated red mud  

Energy Technology Data Exchange (ETDEWEB)

Adsorption of phosphate (PO{sub 4}{sup 3{minus}}) from aqueous solution on activated red mud (ARM) was studied as a function of time, pH, temperature, concentration of adsorbent and adsorbate in acetic acid-sodium acetate buffer medium. The adsorption of phosphate follows Langmuir as well as Freundlich adsorption isotherms. The process efficiency was found to be 80--90% at room temperature. This can be extended to the treatment of industrial effluents containing phosphates like that from phosphatic fertilizer plants.

1998-08-01

85

Refilling Intracellular Calcium Stores  

UK PubMed Central (United Kingdom)

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

2010-01-01

86

Calcium-Actin Waves and Oscillations of Cellular Membranes  

UK PubMed Central (United Kingdom)

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

2009-09-16

88

Rapid determination of "2"3"7Np and Pu isotopes in water by inductively-coupled plasma mass spectrometry and alpha spectrometry  

International Nuclear Information System (INIS)

A new method that allows rapid preconcentration and separation of plutonium and neptunium in water samples was developed for the measurement of "2"3"7Np and Pu isotopes by inductively-coupled plasma mass spectrometry (ICP-MS) and alpha spectrometry. "2"3"8U can interfere with "2"3"9Pu measurement by ICP-MS as "2"3"8UH"+ mass overlap and "2"3"7Np via peak tailing. The method provide enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then moving Pu to DGA resin for additional removal of uranium. The decontamination factor for uranium from Pu is almost 100,000 and the decontamination factor for U from Np is greater than 10,000. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration is performed using a streamlined calcium phosphate precipitation method. Purified solutions are split between ICP-MS and alpha spectrometry so that long and ...

2011-01-01

89

RAPID DETERMINATION OF 237 NP AND PU ISOTOPES IN WATER BY INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY AND ALPHA SPECTROMETRY  

Energy Technology Data Exchange (ETDEWEB)

A new method that allows rapid preconcentration and separation of plutonium and neptunium in water samples was developed for the measurement of {sup 237}Np and Pu isotopes by inductively-coupled plasma mass spectrometry (ICP-MS) and alpha spectrometry; a hybrid approach. {sup 238}U can interfere with {sup 239}Pu measurement by ICP-MS as {sup 238}UH{sup +} mass overlap and {sup 237}Np via peak tailing. The method provide enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then moving Pu to DGA resin for additional removal of uranium. The decontamination factor for uranium from Pu is almost 100,000 and the decontamination factor for U from Np is greater than 10,000. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration is performed using a streamlined calcium phosphate precipitation method. Purified solutions are split between ICP-MS and ...

2010-06-23

90

Liquid radwaste processing with spiral wound reverse osmosis  

International Nuclear Information System (INIS)

Two different reverse osmosis systems were investigated. The first was a 50-element plant-scale system that is used to treat 2200 m"3 of AECL liquid radwastes annually.It uses thin-film composite (TFC) membranes and operates at an applied pressure of 2760 kPa, with a fixed crossflow of about 40 L/min. The other system uses the same thin-film composite membranes for waste processing but is a two-element pilot-scale system. It is operated at pressures m ranging between 1500 and 7000 kPa, at a fixed crossflow of 55 L/min. The average lifetime of the thin-film composite membranes in the plant-scale processing application at AECL is about 3000 h. After this service life has expired the rejection efficiency declines rapidly from 99.5% to about 95% as the membranes become impaired from chemical cleaning procedures that are required after each 100 m"3 of waste is treated. The permeation flux for the plant-scale system decreases from about 2.2 L/min/element to below 0.5 L/min/element at the end ...

1996-02-25

91

Investigating the applicability of anions as indicators for verification of consistency of declarations  

International Nuclear Information System (INIS)

Full text: Nuclear material is subjected to chemical processing throughout the entire fuel cycle. Traces of the chemical reagents and solvents are left behind in the nuclear material. So far essentially metallic impurities or light elements have been investigated for their potential in providing clues on the type of process they originate from. In the present investigation, the applicability of anions for attributing nuclear material to a certain chemical process has been investigated. Anions (e.g. nitrate, sulphate, phosphate, chloride) originate from acids or salt solutions that are used for processing of solutions containing uranium or plutonium. The study presented in this paper focuses on yellow cake samples originating from different mines applying different chemical processes for leaching, dissolving and precipitating the uranium. Consequently, the anionic patterns should be different. The concentrations of different anionic species were measured by ion ...

2006-10-16

92

High extracellular calcium attenuates adipogenesis in 3T3-L1 preadipocytes  

International Nuclear Information System (INIS)

We studied the effect of extracellular Ca"2"+ concentration ([Ca"2"+]_e) on adipocyte differentiation. Preadipocytes exposed to continuous [Ca"2"+]_e higher than 2.5 mmol/l accumulated little or no cytoplasmic lipid compared to controls in 1.8 mmol/l [Ca"2"+]_e. Differentiation was monitored by Oil Red O staining of cytoplasmic lipid and triglyceride assay of accumulated lipid, by RT-PCR analysis of adipogenic markers, and by the activity of glycerol-3-phosphate dehydrogenase (GPDH). Elevated [Ca"2"+]_e inhibited expression of peroxisome proliferator-activated receptor #gamma#, CCAAT/enhancer binding protein #alpha#, and steroid regulatory binding element protein. High [Ca"2"+]_e significantly inhibited differentiation marker expression including adipocyte fatty acid binding protein, and GPDH. The decrease in Pref-1 expression that accompanied differentiation also was prevented by high [Ca"2"+]_e. Treatment of 3T3-L1 cells with high [Ca"2"+]_e did not significantly ...

2004-12-10

93

Creation of bony microenvironment with CaP and cell-derived ECM to enhance human bone-marrow MSC behavior and delivery of BMP-2.  

Science.gov (United States)

Extracellular matrix (ECM) comprises a rich meshwork of proteins and proteoglycans, which not only contains biological cues for cell behavior, but is also a reservoir for binding growth factors and controlling their release. Here we aimed to create a suitable bony microenvironment with cell-derived ECM and biodegradable ?-tricalcium phosphate (?-TCP). More specifically, we investigated whether the ECM produced by bone marrow-derived mesenchymal stem cells (hBMSC) on a ?-TCP scaffold can bind bone morphogenetic protein-2 (BMP-2) and control its release in a sustained manner, and further examined the effect of ECM and the BMP-2 released from ECM on cell behaviors. The ECM was obtained through culturing the hBMSC on a ?-TCP porous scaffold and performing decellularization and sterilization. SEM, XPS, FTIR, and immunofluorescent staining results indicated the presence of ECM on the ?-TCP and the amount of ECM increased with the incubation time. BMP-2 was loaded onto ...

2011-05-31

94

Radon diffusion studies through building construction materials using solid state nuclear track detectors  

International Nuclear Information System (INIS)

Radon appears mainly by diffusion processes from the point of origin following #alpha#- decay of "2"2"6Ra in underground soil and building materials used, in the construction of floors, walls, and ceiling. The transport phenomenon of radon through diffusion is a significant contributor to indoor radon entry. In the present study radon diffusion through sand, cement, mixtures of sand + cement (1:1), sand + cement (2:1), sand + cement (3:1), sand + cement (4:1) has been carried out using LR-115 type II solid state nuclear track detectors (SSNTDs). The radon diffusion coefficient and diffusion lengths have been calculated for different materials. The effect of compaction, which changes the porosity and permeability of the materials, on radon diffusion has also been studied. (author)

2003-10-16

95

Durability of cement-based materials: modeling of the influence of physical and chemical equilibria on the microstructure and the residual mechanical properties; Durabilite des materiaux cimentaires: modelisation de l'influence des equilibres physico-chimiques sur la microstructure et les proprietes mecaniques residuelles  

Energy Technology Data Exchange (ETDEWEB)

A large part of mechanical and durability characteristics of cement-based materials comes from the performances of the hydrated cement, cohesive matrix surrounding the granular skeleton. Experimental studies, in situ or in laboratory, associated to models, have notably enhanced knowledge on the cement material and led to adapted formulations to specific applications or particularly aggressive environments. Nevertheless, these models, developed for precise cases, do not permit to specifically conclude for other experimental conclusions. To extend its applicability domain, we propose a new evolutive approach, based on reactive transport expressed at the microstructure scale of the cement. In a general point of view, the evolution of the solid compounds of the cement matrix, by dissolutions or precipitations, during chemical aggressions can be related to the pore solution evolution, ...

2004-09-15

96

Planning and interpreting cement bond logs; Implementation of an expert system  

Energy Technology Data Exchange (ETDEWEB)

The Cement Bond Log Advisor is an expert system being developed to assist users in the design, evaluation, and interpretation of cement bond logs (CBL's). CBL's are produced by sonic tools run after the casing is cemented in a well to determine how well the cement is bonded to the casing and formation and whether a cement squeeze jog should be attempted. During the development of program, two particular challenges were encountered and resolved in ways that might be of general interest to developers of expert system applications for the petroleum industry. The first challenge was to find an efficient and effective method for guiding the user in correlating and interpreting the relationships between multiple sources of continuous visual data (the various waveforms making up the log output). Second, the nomographs, which correlate log amplitudes with ...

1991-07-01

108

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

UK PubMed Central (United Kingdom)

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

2009-01-01

109

Characteristics of diethylenetriamine-crosslinked cotton stalk/wheat stalk and their biosorption capacities for phosphate  

British Library Electronic Table of Contents (United Kingdom)

Two polymeric biosorbents were prepared from cotton stalk (CS) and wheat straw (WS) by the epichlorohydrin-diethylenetriamine-trimethylamine method. Amine-crosslinked cotton stalk (AC-CS) and wheat stalk (AC-WS) were used for the adsorption of phosphate, and their physicochemical properties as well as biosorption properties for phosphate were discussed intensively. Results indicated that the contents of holocellulose in CS and WS corresponded to the distinct phosphate adsorption capacities between AC-CS and AC-WS. Zeta potential and Raman spectra analysis illustrated the electrostatic attraction between phosphate ions and biosorbents. The adsorption of phosphate was not strongly pH dependent when the pH was about 4.0-9.0. The Langmuir isotherm provided the better fit and the maximum adsorp...

2011-01-01

110

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

Energy Technology Data Exchange (ETDEWEB)

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

2004-07-01

111

Evaluation of a novel radiopacifiying agent on the physical properties of surgical spineplex.  

Science.gov (United States)

Polymethlylmethacrylate (PMMA) is the most frequently used cement for percutaneous vertebroplasty and kyphoplasty. To aid visualisation during surgery cements are doped with radiopacifying agents such as Barium sulphate (Ba(2)SO(4)) or Zirconium Dioxide (ZiO(2)). Mounting research suggests that these agents may impair the biocompatibility of the cements. However, incorporating an alternative radiopacifier agent with excellent biocompatibility would be a significant step forward. Bioactive radiopaque glasses incorporating elements such as strontium (Sr) and zinc (Zn), known to have beneficial and therapeutic effects on bone, are of great interest in this respect. In this study, the Ba(2)SO(4) of the commercially available Spineplex was incrementally replaced with a radiopaque therapeutic glass composition. The resulting effects on cement setting time, peak isotherm, ultimate compressive strength, Young's ...

2009-08-18

112

Two tandemly linked identical genes code for the glycosomal glyceraldehyde-phosphate dehydrogenase in Trypanosoma brucei.  

UK PubMed Central (United Kingdom)

Trypanosoma brucei contains two isoenzymes for glyceraldehyde-phosphate dehydrogenase (GAPDH); one enzyme resides in a microbody-like organelle, the glycosome, the other one is found in the cytosol....Full Text Available

1986-05-01

113

Trypanosoma cruzi glycosomal glyceraldehyde-3-phosphate dehydrogenase does not conform to the 'hotspot' topogenic signal model.  

UK PubMed Central (United Kingdom)

The genes which encode glycosomal glyceraldehyde-phosphate dehydrogenase (gGAPDH) of Trypanosoma cruzi are arranged as a tandemly repeated pair on a single chromosome and are identical at the level...Full Text Available

1990-09-01

114

Triosephosphates Modulate Leaf Mitochondrial Phosphorylation by Inhibition and Uncoupling of Electron Transport 1  

UK PubMed Central (United Kingdom)

The effect of TP (triosephosphates:glyceraldehyde-3 phosphate, GAP, +dihydroxyacetone phosphate, DHAP) on respiration, phosphorylation and matrix ATP/ADP ratios of isolated oat mesophyll mitochondria...Full Text Available

1985-11-01

115

The comparative structure of mammalian glyceraldehyde 3-phosphate dehydrogenase  

UK PubMed Central (United Kingdom)

1. The amino acid sequences around the thiol groups of glyceraldehyde 3-phosphate dehydrogenase from badger and monkey skeletal muscle were compared with the sequences around the thiol groups in the...Full Text Available

1969-01-01

116

Phosphate/UO{sub 2} interaction during in vitro dissolution of inhalable particles in a medium simulating the phagolysosomal compartment  

Energy Technology Data Exchange (ETDEWEB)

Qualitative and quantitative methods have been developed to relate phosphate/UO{sub 2} interactions and U dissolution, in vitro, in a medium containing 0 or 10 mM phosphate concentrations at pH 5. This was performed by Energy Dispersive X ray Spectrometry (EDS) at 200 kV on entire particles and by fluorimetric measurement. The U dissolution rate was larger in a medium without phosphate than in a medium containing 10 mM phosphate. During the first day, the initial U dissolution involved 80.55% and 91.13% of the powder in media with and without phosphate respectively. From 5 to 15 d after beginning the assay, the dissolution half-times were longer than 92 d and 22 d for media with and without phosphate. EDS analyses have shown a constant P/U X ray intensity ratio for reference U{sub 2}O(PO{sub 4}){sub 2} for the same range of particle diameter. A gradual increase ...

1998-07-01

117

On the water-chemical regime in steam generators at NPP  

British Library Electronic Table of Contents (United Kingdom)

The effect of the water-chemical regime (WCR) on damage sustained by heating surfaces of steam generators at NPP is analyzed. It is indicated that phosphate treatment with minimal excesses of phosphates in the steamgenerator water is the most optimal method of managing the WCR regime of horizontal steam generators.

2006-01-01

118

Kinetic Properties of Pyrophosphate:Fructose-6-Phosphate Phosphotransferase from Germinating Castor Bean Endosperm 1  

UK PubMed Central (United Kingdom)

Pyrophosphate:fructose-6-phosphate phosphotransferase (PFP) was purified over 500-cold from endosperm of germinating castor bean (Ricinus commiunis L. var. Hale). The kinetic properties...Full Text Available

1984-02-01

119

Isoenzymes of Sugar Phosphate Metabolism in Endosperm of Germinating Castor Beans 1  

UK PubMed Central (United Kingdom)

Two isoenzymes each of phosphoglucomutase, hexose phosphate isomerase, aldolase, fructose diphosphatase, phosphofructokinase, and 6-phosphogluconate dehydrogenase have been separated by DEAE-cellulose...Full Text Available

1981-06-01

120

Iodination of glyceraldehyde 3-phosphate dehydrogenase from Bacillus stearothermophilus.  

UK PubMed Central (United Kingdom)

The reaction of iodine with glyceraldehyde 3-phosphate dehydrogenase from Bacillus stearothermophilus was investigated. The active-site thiol group of the cysteine residue homologous with cysteine-149...Full Text Available

1976-06-01

121

Effects of norepinephrine infusion on myocardial high-energy phosphate content and turnover in the living rat.  

UK PubMed Central (United Kingdom)

Using 31P-nuclear magnetic resonance, we studied the relationship between myocardial high-energy phosphate content and flux values for the creatine kinase reaction in the living rat under inotropic...Full Text Available

1987-06-01

122

Complete sequence of the chicken glyceraldehyde-3-phosphate dehydrogenase gene.  

UK PubMed Central (United Kingdom)

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), an evolutionarily conserved glycolytic enzyme, is constitutively expressed in most cell types yet is induced to high levels during the development of...Full Text Available

1985-03-01

123

Apoferritin Templated Synthesis of Metal Phosphate Nanoparticle Labels for Electrochemical Immunoassay  

Energy Technology Data Exchange (ETDEWEB)

W have introduced template-synthesized metal phosphate nanoparticle labels for electrochemical immunoassay. Such use of an apoferritin template offers a simple and convenient route to prepare metallic nanoparticle labels for electrochemical immunoassays and avoid the complicated and time-consuming nanoparticle synthesis process (QD synthesis). Releasing metal ions from metal phosphate in an acetate buffer (pH 4.6) eliminates the harsh condition in the traditional metallic nanoparticle dissolution (e.g., strong acid dissolution of QDs and gold nanoparticles). This method is ultrasensitive and its DL is low to 77fM. The simultaneous detection of multiple protein targets is easily performed by using different metal phosphate nanoparticle labels (cadmium phosphate and lead phosphate). This approach can be extended to prepare multiple metal (such as zinc, lead, cadmium, copper, indium, ...

2006-08-29

124

Study on the use of zirconium phosphate for radioactive waste treatment  

International Nuclear Information System (INIS)

Zirconium phosphate was one of the earliest inorganic ion-exchange suggested for removing strontium and cesium from aqueous nuclear waste. This paper studied ionic exchange to remove Cs-137 and Sr-90 by using different cationic of zirconium phosphate. In this case the parameters studied were the effect of temperature and ion concentration to percent up take and distribution coefficients. It is also conducted the study on column experiments to determine the breakthrough curves for Cs-137 and Sr-90. The result showed the potential of use of zirconium phosphate in radioactive waste treatment. (author)

1998-12-01

126

Ammoxidation of methanol to produce hydrogen cyanide  

Energy Technology Data Exchange (ETDEWEB)

Promoted antimony phosphate oxide complexes are excellent catalysts for the ammoxidation of methanol to HCN especially at high methanol throughputs.

1985-04-16

127

Production of bone cement composites: effect of fillers, co-monomer and particles properties  

International Nuclear Information System (INIS)

Artificial bone cements (BCs) based on poly(methyl methacrylate) (PMMA) powders and methyl methacrylate (MMA) liquid monomer also present in their formulation small amounts of other substances, including a chemical initiator compound and radiopaque agents. Because inadequate mixing of the recipe components during the manufacture of the bone cement may compromise the mechanical properties of the final pieces, new techniques to incorporate the fillers into the BC and their effect upon the mechanical properties of BC pieces were investigated in the present study. PMMA powder composites were produced in situ in the reaction vessel by addition of X-ray contrasts to the reacting MMA mixture. It is shown that this can lead to much better mechanical properties of test pieces, when compared to standard bone cement formulations, because enhanced dispersion of the radiopaque agents can be achieved. Moreover, it is shown that the ...

128

Preparation of special cements from red mud  

Energy Technology Data Exchange (ETDEWEB)

Red mud from HINDALCO (Hindustan Aluminium Corporation) Industries Limited, Renukoot, India, contains significant quantities of alumina, iron oxide and silica. Presence of the said constituents makes it a suitable ingredient for the preparation of special cements. Preparation of three varieties of cements was investigated, namely: (a) aluminoferrite (C{sub 4}AF)-belite ({beta}-C{sub 2}S) using lime + red mud + fly ash; (b) aluminoferrite-ferrite (C{sub 2}F)-aluminates (C{sub 3}A and C{sub 12}A{sub 7}) utilizing lime + red mud + bauxite; and (c) sulfoaluminate (C{sub 4}A{sub 3}{bar S})-aluminoferrite-ferrite using lime + red mud + bauxite + gypsum. The effects of composition (proportions of lime, red mud, fly ash, bauxite and gypsum), firing temperature and duration on the properties of cements produced were studied in detail. Cements made from lime + red mud + bauxite or lime + red mud + bauxite + ...

1996-12-31

129

Physico-chemical behaviour of a barrier composed of cement kiln dust and fly ash; Comportement physico-chimique d'une barriere a base de poussieres de four de cimenterie et de cendres volantes  

Energy Technology Data Exchange (ETDEWEB)

Controlling acid mine drainage is one of the most important challenges facing the mining industry. One of the solutions to this problem is the use of soil covers. In this poster presentation, the author described the development of a soil barrier composed of cement kiln dust and fly ash. In the study, four different cement kiln dust were associated to three different fly ash types, for a total of twelve different mix. The objective was to develop a stable environmental barrier. The origin of the cement kiln dust was described, followed by the characterization and preparation of the different mix, and the monitoring of the hydration process. The results were discussed, and indicated that a barrier composed of cement kiln dust and fly ash seemed to have great potential. The results also indicated that the fly ash improve the properties of the cement kiln dust, but that the improvement ...

2000-07-01

130

Comparative investigation of corrosion resistance of steel reinforcement in alinite and Portland cement mortars  

Energy Technology Data Exchange (ETDEWEB)

The corrosion resistance of steel-reinforced mortar specimens made from alinite cement was investigated using ordinary Portland cement (OPC) specimens as reference. The specimens were prepared and exposed in three different environments: continuous exposure in tap water, interrupted exposure in tap water, and interrupted exposure in 3.5% NaCl solution. The steel weight loss and the half cell potential were measured vs. exposure time, up to the age of 12 months. Pore solution extraction and analysis and porosity determination were also performed. In continuous exposure in tap water, alinite cement provided adequate protection against corrosion. In interrupted exposure in tap water, a higher corrosion was observed for alinite cement compared to OPC. In the case of interrupted exposure in 3.5% NaCl solution, the simultaneous action of free chlorides and oxygen resulted in the depassivation of steel ...

1998-07-01

131

The content of natural radioactive materials in phosphate fertilizers and their contribution to the radiation exposure of the human population  

International Nuclear Information System (INIS)

The Ra, Th, and K-40 content of the most important phosphate fertilizers used and authorized in the FRG was determined by #gamma#-spectroscopy. The results, together with statistical data on the consumption and use of fertilizers, were used for an estimation of the contribution of #gamma#-radiation from phosphate fertilizers to the external population exposure in the FRG. (orig./AK).

1974-09-23

132

Ribose metabolism and nucleic acid synthesis in normal and glucose-6-phosphate dehydrogenase-deficient human erythrocytes infected with Plasmodium falciparum.  

UK PubMed Central (United Kingdom)

The metabolism of pentose-phosphate was investigated in Plasmodium falciparum-infected normal and glucose-6-phosphate dehydrogenase (G6PD)-deficient human red blood cells in vitro. 5'-Phosphoribosyl-1-pyrophosphate...Full Text Available

1986-04-01

133

Treatment technology for transuranic waste streams: Cementation, vitrification, and incineration testing for the treatment of spent ion exchange media  

Energy Technology Data Exchange (ETDEWEB)

This document reports the results of testing of spent ion exchange media pretreatment technologies. Emphasis of the testing activities has been on screening pretreatment technologies, such as drying and emulsification, which are compatible with vitrification, cementation, and incineration. Ion exchange media tested for cementation and incineration pretreatment technologies were typical organic ion exchange resins and inorganic zeolites. The ion exchange medium tested for vitrification pretreatment technologies was inorganic zeolite. The results of testing activities are discussed in detail in this report.

1992-04-01

134

The crack of harden cement paste observed with multi-technique  

British Library Electronic Table of Contents (United Kingdom)

The shrinkage of the cement paste with low water-cement ratio at different relative humidity was observed and analyzed with ESEM and deformation map technique. The crack morphology was observed with different magnification with SEM and FESEM, and the formation of the crack was observed with AFM between two C-S-H nano particles. The observation by multi technique at multi scale indicated that the shrinkage was increase with the decrease of the humidity due to the increase of the pressure of the capillary pressure, the morphology of the crack in smaller scale was similar to that in the bigger scale, the smaller crack distributed in the latticework of the bigger ones, and the crack propagated along the gap between two nano particles of C-S-H with weaker bonding.

2010-01-01

135

Zhdanovka coking chemists and agriculture  

Energy Technology Data Exchange (ETDEWEB)

The Zhdanovka Coking Plant supplies materials for commercial use, e.g. ammonium sulfate and colloidal sulfur for agriculture and road-cementing materials. The method used for the production of colloidal sulfur is described briefly.

1984-01-01

136

Stabilization of geothermal residues by encapsulation in portland cement-based composites  

Energy Technology Data Exchange (ETDEWEB)

Presented are the results from a laboratory test program conducted to identify and evaluate materials for converting hazardous geothermal residues to a non-hazardous and potentially usable form. Results indicate that the residues can be effectively incorporated, as a fine aggregate, into portland cement-based composites. Five geothermal residues obtained from sites in the Salton Sea area of California were evaluated. Three of these were classified as hazardous. After mixing with cement, the leach rates were all well below specified levels. Although structural-grade composites were produced, gradual reductions in properties with time up to 1 yr were noted. This indicates ongoing chemical reactions between the cement paste and the constituents of the residues. Further research is necessary before the composites could be considered for use in structural applications. 3 refs., 8 tabs.

1988-05-01

137

Science and Technology Centers  

Science.gov (United States)

... MPS) Advanced Liquid Crystalline Optical Materials Superconductivity Computation and Visualization ... Cement-Based Materials Synthesis, Growth, and Analysis of Electronic Materials Photoinduced Charge ...

139

Micro-analysis of ?salt weathering? on cement paste  

British Library Electronic Table of Contents (United Kingdom)

Normally, concrete technologists attribute salt weathering, salt crystallization or physical attack to the deterioration of concrete that is partially exposed to sulfate environment. However, there are few convincing evidences supporting this view. The purpose of this paper is to check by means of extensive micro-analysis if traces of sulfate crystals are present in the paste. This would enable to verify in a direct way whether salt weathering really causes cement paste damage or not.In this research, cement paste and cement?fly ash paste specimens were partially exposed to sodium sulfate and magnesium sulfates solution under a constant storage condition (20 ? 2 ?C, and 60 ? 5% RH) and a sharply fluctuating environment (40 ? 2 ?C and 35 ? 5% RH for 24 h, then 10 ? 1 ?C and 85 ? 5% RH, also...

2011-01-01

140

Kinetics and mechanism of the reaction between portland cement and clinoptilolite  

International Nuclear Information System (INIS)

When clinoptilolite is immobilized in cement-based composites, a series of reactions occur, leading to release of Cs. These reactions occur in three overlapping stages: a rapid ion exchange, followed by a somewhat slower reaction between clinoptilolite and principally the Ca(OH)_2 component of cement, and, in the longer term, slower reactions with C-S-H leading either to formation of low-lime C-S-H at temperatures below 100"0C or 11 A (1.1 nm) tobermorite at higher temperatures. Kinetic data are presented to evaluate the rate of physical consumption of the zeolites at 70 and 150"0C. Reactions occurring above 100"0C appear to result in the development of extensive microcracking of cement-zeolite composites containing 50% zeolite.

141

Intravertebral body reconstruction with an injectable in situ-setting carbonated apatite: biomechanical evaluation of a minimally invasive technique.  

Science.gov (United States)

The ability to mechanically reinforce an osteoporotic vertebral body could impede spinal compression fracture and the associated pain and complications. Previous studies have shown that reinforcement of fractured vertebrae with conventional acrylic cement can relieve symptoms and avoid further collapse. In this study, we explored the use of a carbonated apatite cement combined with a minimally invasive injection technique to improve the compressive mechanical properties of cadaveric vertebral bodies. After establishing the biomechanical characteristics of cement formulations intended to have appropriate viscosities, we evaluated the infiltration of the cements into thoracic vertebral bodies using a combined suction-injection technique. The energy-absorption capabilities of the reinforced vertebral bodies were then measured during axial compressive tests and compared with those of nonreinforced ...

1999-01-01

142

Development of fluidized bed cement sintering technology  

Energy Technology Data Exchange (ETDEWEB)

In the new system presented in this paper, the cement clinker is sintered, not in a rotary kiln, but in two different furnaces: a spouted bed kiln and a fluidized bed kiln. The heat generated in the process of cooling the cement clinker is recovered by a fluidized bed cooler and a packed bed cooler, which are more efficient than the conventional coolers. Compared with the rotary kiln system, the new technology significantly reduces NO{sub x} emissions, appreciably cuts energy consumption, and reduces CO{sub 2} emissions as well. Thus, the new system is an efficient cement sintering system that is friendly to the global environment. In this paper, we describe this new technology as one of the applied technologies at an industrial level that is being developed in the Clean Coal Technology Project, and we present the results from test operations at our pilot plant.

1994-12-31

143

Cement-clay pastes for stabilization/solidification of 2-chloroaniline  

International Nuclear Information System (INIS)

Immobilization of a model liquid organic pollutant, i.e. the 2-chloroaniline (2-CA), into a cement matrix using organoclays as pre-sorbent agents was investigated. Five cement-clay pastes were prepared with different nominal water-to-cement ratios (w/c=0.40, 0.25 and 0.15 wt/wt) and various amounts of waste (waste-to-cement o/c=0.20, 0.60 and 1.00 wt/wt); for comparison, a neat cement paste was also prepared. Dynamic leach tests were performed on solidified monoliths in order to assess the successful immobilization of the 2-CA. In monoliths at constant w/c ratio (0.40) the total amount of pollutant released increases with its initial content, and ranges from 15 to 35% with respect to it. By lowering w/c from 0.40 to 0.15 at constant o/c, the performances improved (<25% released). The microstructure of the hardened cement-clay pastes was characterized by ...

2004-01-01

144

Microtiter plate assay for phosphate using a europium-tetracycline complex as a sensitive luminescent probe  

Energy Technology Data Exchange (ETDEWEB)

A new luminescent europium probe is presented for the determination of phosphate (P) in microtiter plate format. The assay is based on the quenching of the luminescence of the europium-tetracycline (EuTc) 1:1 complex by phosphate using a reagent concentration of 20.8 {mu}mol/L. The probe is excited at 400 nm and displays a large Stokes' shift of 210 nm. The emission maximum is located at 616 nm. The system works best at neutral pH 7 and is therefore suitable for phosphate determination in biological and biochemical systems. The linear range of the calibration plot is from 5 x 10{sup -6} mol/L to 7.5 x 10{sup -4} mol/L of phosphate, and the limit of detection is 3 {mu}mol/L.

2006-01-12

145

Removal of phosphate by mesoporous ZrO{sub 2}  

Energy Technology Data Exchange (ETDEWEB)

A type of mesoporous ZrO{sub 2} was synthesized and its phosphate removal potential was investigated in this study. The adsorption isotherm, pH effect, ionic strength effect and desorption were examined in batch experiments. The adsorption data fitted well to the Langmuir model with which the maximum P adsorption capacity was estimated to be 29.71 mg P/g. The amount of phosphate adsorbed increased rapidly in the first 5 h and slowly towards the end of the run, suggesting the possible monolayer coverage of phosphate ions on the surface of the adsorbent. The phosphate adsorption tended to increase with a decrease of pH and an increase of ionic strength. A phosphate desorbability of approximately 60% was observed with 0.5 M NaOH, which indicated a relatively strong bonding between the adsorbed PO{sub 4}{sup 3-} and the sorptive sites on the surface of the adsorbent. The immobilization ...

2008-03-01

146

Apoferritin-Templated Yttrium Phosphate Nanoparticle Conjugates for Radioimmunotherapy of Cancers  

Energy Technology Data Exchange (ETDEWEB)

We report a templated-synthetic approach based on apoferritin to prepare radionuclide nanoparticle (NP) conjugates. Non-radioactive yttrium (89Y) was used as model target and surrogate for radioyttrium (90Y) to prepare the nanoparticle conjugate. The center cavity and multiple channel structure of apoferritin offer a fast and facile method to precipitate yttrium phosphate by diffusing yttrium and phosphate ions into the cavity of apofrritin, resulting a core-shell nanocomposite. The yttrium phosphate/apoferritin nanoparticle was functionalized with biotin for further application. The synthesized nanoparticle was characterized by transmission electron microscopy (TEM) and x-ray photoelectron spectroscopy (XPS). We found that the resulting nanoparticles were uniform in size, with a diameter of around 8 nm. We tested the pre-targeting capability of the biotin-modified yttrium phosphate/apoferritin ...

2008-05-01

147

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

UK PubMed Central (United Kingdom)

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

1991-02-01

148

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

UK PubMed Central (United Kingdom)

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

2010-01-01

149

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

UK PubMed Central (United Kingdom)

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

1980-10-01

150

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

UK PubMed Central (United Kingdom)

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

2010-08-01

151

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

UK PubMed Central (United Kingdom)

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

2008-02-01

152

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

UK PubMed Central (United Kingdom)

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

2006-10-14

153

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

UK PubMed Central (United Kingdom)

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

2010-06-01

154

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

UK PubMed Central (United Kingdom)

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

2010-05-01

155

Calcium - blood test: MedlinePlus Medical Encyclopedia  

Science.gov (United States)

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

2011-08-30

156

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

UK PubMed Central (United Kingdom)

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

1989-06-01

157

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

UK PubMed Central (United Kingdom)

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

2009-08-26

158

Powder metallurgical high performance materials. Proceedings. Volume 3: general topics  

International Nuclear Information System (INIS)

The proceedings of these seminars form an impressive chronicle of the continued progress in the understanding of refractory metals and cemented carbides and in their manufacture and application. The 15"t"h Plansee Seminar was convened under the general theme 'Powder Metallurgy High Performance Materials'. Under this broadened perspective the seminar will strive to look beyond the refractory metals and cemented carbides, which remain at its focus, to novel classes of materials, such as intermetallic compounds, with potential for high temperature applications. (boteke)

2001-05-01

159

Development of Bulk Nanocrystalline Cemented Tungsten Carbide for Industrial Applicaitons  

Energy Technology Data Exchange (ETDEWEB)

This report contains detailed information of the research program entitled "Development of Bulk Nanocrystalline Cemented Tungsten Carbide Materials for Industrial Applications". The report include the processes that were developed for producing nanosized WC/Co composite powders, and an ultrahigh pressure rapid hot consolidation process for sintering of nanosized powders. The mechanical properties of consolidated materials using the nanosized powders are also reported.

2009-03-10

160

Clinical and biological assessment of cemented titanium femoral stems: an 11-year experience  

UK PubMed Central (United Kingdom)

This study prospectively assessed the outcome of 134 cemented titanium stems and serum ion levels. The stems were polished (0.1 μm Ra) with circular cross section. At the end point,...Full Text Available

2009-10-01

162

Smoke Compositions Based on Phosphorus  

Science.gov (United States)

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

1958-03-01

163
164

Effect of VC and NbC additions on microstructure and properties of ultrafine WC-10Co cemented carbides  

British Library Electronic Table of Contents (United Kingdom)

The nanocomposite WC-Co powders were prepared through planetary ball milling method. Effects of grain growth inhibitor addition and the vacuum sintering parameters on the microstructure and properties of ultrafine WC-10Co cemented carbides were investigated using X-ray diffractometer, scanning electron microscope and mechanical property tester. The results show that VC and NbC additions can refine the WC grains, decrease the volume fraction of Co3W3C phase in ultrafine WC-10Co cemented carbides, and increase the hardness and fracture toughness of the base alloys. After sintering for 60 min at 1400 degreeC, the average grain size and hardness of ultrafine-grained WC-10Co-1VC cemented carbide are 470 nm and HRA 91.5, respectively. The fracture toughness of cemented carbide WC-10Co-1NbC alloy...

2009-01-01

165

Effect of Non-aqueous Solvents on the Rate of Production of Copper Powder from Copper Sulphate Solution by Cementation on Stationary Zinc Sheet and Rotating Zinc Cylinder  

Scientific Electronic Library Online (English)

Abstract in english The rate of copper II/zinc cementation from copper sulphate solutions in the absence and in the presence of methanol (CH3OH) and dimethyl sulphoxide (DMSO) has been studied and the reaction was found to follow first-order kinetics. The influence of several parameters on the course of the reaction, such as cylinder rotation speed, initial concentration of Cu2+ ions, temperature and concentration of organic solvent, was investigated. In the case of CH3OH, rotating zinc cyli (more) nder was used, while in the presence of DMSO stationary zinc sheet and rotating zinc cylinder were used. It was found that (1) the percentage inhibition caused by methanol ranged from 10.70 to 58.38 depending on the concentration of the alcohol used; (2) the rate of cementation in the presence of DMSO using rotating zinc cylinder > the rate of cementation in the presence of DMSO using stationary zinc sheet; (3) the rate of ...

2004-01-01

166

Deposition and diagenesis of a cratonic Silurian platform reef, Pipe Creek Jr. , Indiana  

Energy Technology Data Exchange (ETDEWEB)

Petrographic and geochemical characteristics of the Pipe Creek Jr. paragenesis record the stratigraphic and burial evolution of the cratonic Silurian platform of Indiana during Late Silurian to Pennsylvanian. A variety of several diagenetic fluids acting over geological time affected the reef. The paragenetic sequence is as follows: (1) precipitation of turbid, fibrous, blotchy cathodoluminescent (CL) cement; (2) dolomitization of mud-rich facies; (3) precipitation of clear, zoned CL equant calcite cements; (4) fracturing and karst formation, partially filled by geopetal silt and sandstone; (5) precipitation of clear, dull CL, ferroan to nonferroan equant calcite cement, ferroan dolomite overgrowth and equant dolomite cement in moldic porosity, caves and fractures; (6) microdissolution and hydrocarbon emplacement; and (7) stylolitization. The New Albany Shale was both the hydrocarbon source and top seal ...

1988-02-01

167

Removal of noxious contaminants from gas  

Science.gov (United States)

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

1980-09-16

168

Calcium fluoride window mounting  

International Nuclear Information System (INIS)

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

169

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

Energy Technology Data Exchange (ETDEWEB)

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

1994-05-01

170

Equilibrium, kinetics and thermodynamic studies on phosphate biosorption from aqueous solutions by Fe(III)-treated Staphylococus xylosus biomass: Common ion effect  

British Library Electronic Table of Contents (United Kingdom)

The biosorption of phosphate from aqueous solutions using Fe(III)-treated Staphylococus xylosus cells was investigated. Langmuir and Freundlich isotherm models were applied to describe the adsorption equilibrium and found that Langmuir isotherm model fitted the equilibrium data better than Freundlich isotherm model. The biosorption capacity of Fe(III)-treated biomass for phosphate was found to be 70.92mg/g at optimum conditions of pH 3.0, biomass concentration 0.5g/L and equilibrium phosphate-biomass time 60min respectively. The sorption efficiency at initial phosphate concentration of 50mg/L was not influenced upon addition of SO4^2^-, Cl^-, CO3^2^-, NO3^-, Mg^2^+ and Ca^2^+ ions from 0 to 800mg/L, whereas under the same conditions, phosphate sorption was increased with increase in concen...

2011-01-01

171

IMPROVED NATURAL GAS STORAGE WELL REMEDIATION  

Energy Technology Data Exchange (ETDEWEB)

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

2001-12-01

172

The compressive strength of cement blocks permeated with an organic phase change material  

Energy Technology Data Exchange (ETDEWEB)

The authors investigate the feasibility of constructing walls and partitions with enhanced heat storage capability from cement blocks permeated with an organic phase change material (pressed stearic acid). The blocks are lightweight, easy to produce and are cured in the same way as cement or concrete. The ratio of components (cement, stearic acid (SA) and water) was optimized with respect to compressive strength. With normal portland cement, the best compressive strength 2.2 MPa was obtained with a ratio C:SA:W of 1:0.8:0.65 (i.e. 32% stearic acid) after 28 days of curing. This was increased to 4.4 MPa when high early strength cement was used, about as strong as Sipporex, lightweight concrete or lightweight clay bricks. As expected, the compressive strength decreased linearly with temperature between 25/sup 0/C and 100/sup 0/C, at a rate of 15 kPa//sup 0/C. The drying shrinkage of ...

1984-01-01

173

The phosphate complexation of neptunium(V)  

International Nuclear Information System (INIS)

The phosphate complexation of Np(V) is investigated in the pH range from 6.4 to 10.0 in 0.1 M NaClO_4 at 22#+-#2 C by absorption spectroscopy. The formation of two phosphate complexes is confirmed by spectroscopic speciation: NpO_2HPO"-_4 at 988.8 nm and NpO_2PO"2"-_4 at 993.6 nm with molar extinction coefficients of 251#+-#8 and 201#+-#11 1/mol cm, respectively. The complexation constants are determined to be log #beta# = 2.54#+-#0.02 for NpO_2HPO"-_4 and log #beta# = 6.33#+-#0.08 for NpO_2PO"2"-_4. The competition of the phosphate complexation with the carbonate complexation is demonstrated by speciation calculation under different geochemical conditions. (orig.).

1996-01-01

174

Research Activities in the Spokane, Washington, Field Office...  

Science.gov (United States)

other chemical applications include use in water softeners, detergents, and food additives. The development of phosphate resources as a leasable commodity provides income to...

2011-08-20

175

New NZP-phosphates B{sub 0.5}FeTa(PO{sub 4}){sub 3} (where B - Ca, Sr, Ba)  

Energy Technology Data Exchange (ETDEWEB)

New phosphates with NaZr{sub 2}(PO{sub 4}){sub 3} structure of the B{sub 0.5}FeTa(PO{sub 4}){sub 3}-type (where B-Ca, Sr, Ba) are synthesized and characterized by X-ray diffraction analysis and IR-spectroscopy. The heating behavior of the phosphates is studied using high-temperature X-ray crystallography in the range 15-625 deg. C. The unit-cell parameters, the coefficients of thermal expansion {alpha}{sub a}, {alpha}{sub c} and their thermal expansion anisotropy |{alpha}{sub c} - {alpha}{sub a}| of the phosphates under study are determined and the dependences of these characteristics on the nature of cations are established and analyzed.

2009-05-05

176

A high-performance liquid chromatography-based radiometric assay for sucrose-phosphate synthase and other UDP-glucose requiring enzymes  

Energy Technology Data Exchange (ETDEWEB)

A method for product analysis that eliminates a problematic step in the radiometric sucrose-phosphate synthase assay is described. The method uses chromatography on a boronate-derivatized high-performance liquid chromatography column to separate the labeled product, (14C)sucrose phosphate, from unreacted uridine 5{prime}-diphosphate-(14C)glucose (UDP-Glc). Direct separation of these compounds eliminates the need for treatment of the reaction mixtures with alkaline phosphatase, thereby avoiding the problem of high background caused by contaminating phosphodiesterase activity in alkaline phosphatase preparations. The method presented in this paper can be applied to many UDP-Glc requiring enzymes; here the authors show its use for determining the activities of sucrose-phosphate synthase, sucrose synthase, and uridine diphosphate-glucose pyrophosphorylase in plant extracts.

1991-05-01

177

Waste form development. [Hydraulic cements, hydraulic cements with additives, polymer modified gypsum cement, thermosetting polymers  

Energy Technology Data Exchange (ETDEWEB)

In this program, contemporary solidification agents are being investigated relative to their applications to major fuel cycle and non-fuel cycle low-level waste (LLW) streams. Work is being conducted to determine the range of conditions under which these solidification agents can be applied to specific LLW streams. These studies are directed primarily towards defining operating parameters for both improved solidification of problem wastes and solidification of new LLW streams generated from advanced volume reduction technologies. Work is being conducted to measure relevant waste form properties. These data will be compiled and evaluated to demonstrate compliance with waste form performance and shallow land burial acceptance criteria and transportation requirements (both as they exist and as they are modified with time). 6 tables.

1982-01-01

178

WC-TiC-Ni cemented carbide with enhanced properties  

British Library Electronic Table of Contents (United Kingdom)

In the paper, the effect of Ni content, WC grain size and Mo2C addition on WC-6.25wt%TiC-9.3wt%Ni cemented carbide were investigated to improve the properties of Ni-bonded cemented carbides. The results show that the decrease of Ni content will result in the decrease of transverse rupture strength and increase of hardness; with the decrease of WC particle size, hardness increases due to the refinement of WC grains, however, the transverse rupture strength decrease due to the decrease of Ni binder thickness; Mo2C proves to be an effective grain growth inhibitor. With the increase of Mo2C content, the WC grains are refined and the hardness and transverse rupture strength are improved. Generally, when the Ni content is decreased to 8.4wt%, 13.45mm WC is used and 1.2wt% Mo2C is added, a higher...

2008-01-01

179

Thermal denitration and mineralization of waste constituents  

Energy Technology Data Exchange (ETDEWEB)

In order to produce a quality grout from LLW using hydraulic cements, proper conditioning of the waste is essential for complete cement curing. Several technologies were investigated as options for conditions. Since the LLW is dilute, removal of all, or most, of the water will significantly reduce the final waste volume. Neutralization of the LLW is also desirable since acidic liquids to not allow cement to cure properly. The nitrate compounds are very soluble and easily leached from solid waste forms; therefore, denitration is desirable. Thermal and chemical denitration technologies have the advantages of water removal, neutralization, and denitration. The inclusion of additives during thermal treatment were investigated as a method of forming insoluable waste conditions.

1997-08-01

180

Preliminary study on improvement of cementitious grout thermal conductivity for geothermal heat pump applications  

Energy Technology Data Exchange (ETDEWEB)

Preliminary studies were preformed to determine whether thermal conductivity of cementitious grouts used to backfill heat exchanger loops for geothermal heat pumps could be improved, thus improving efficiency. Grouts containing selected additives were compares with conventional bentonite and cement grouts. Significant enhancement of grout alumina grit, steel fibers, and silicon carbide increased the thermal conductivity when compared to unfilled, high solids bentonite grouts and conventional cement grouts. Furthermore, the developed grouts retained high thermal conductivity in the dry state, where as conventional bentonite and cement grouts tend to act as insulators if moisture is lost. The cementitious grouts studied can be mixed and placed using conventional grouting equipment.

1996-06-01

181

Influence of substructure design and spacer settings on the in vitro performance of molar zirconia crowns  

British Library Electronic Table of Contents (United Kingdom)

Objectives: The aim of this study was to evaluate the in vitro behaviour of all-ceramic zirconia molar crowns in regard to different core designs and marginal fit. Methods: Identically shaped methacrylate molars were prepared according to the ceramic restoration directives resulting in a 1-mm deep circular shoulder preparation. They were embedded in polymethylmethacrylate resin after covering their roots with a polyether layer to simulate periodontal mobility. The crown cores were made of yttria-stabilized zirconia veneered with a corresponding veneering ceramic. The crowns were divided into 5 groups (n=8) which differed in core design and cement gap thickness: #1: simple core, 40mm cement; #2: core with minimal occlusal support, 40mm cement; #3: core with optimized cusp support, 40mm ceme...

2009-01-01

182

Impact of Cr3C2/VC addition on the dry sliding friction and wear response of WC-Co cemented carbides  

British Library Electronic Table of Contents (United Kingdom)

Two grades of WC-10wt.%Co cemented carbide with or without addition of Cr3C2/VC grain growth inhibitor during liquid phase sintering were produced with the goal to investigate their reciprocating sliding friction and wear behaviour against WC-6wt.%Co cemented carbide under unlubricated conditions. The tribological characteristics were obtained on a Plint TE77 tribometer using distinctive normal contact loads. The generated wear tracks were analyzed by scanning electron microscopy and quantified topographically using surface scanning equipment. The post-mortem obtained wear volumes were compared to the online assessed wear. Correlations between wear volume, wear rate and coefficient of friction on the one hand and sliding distance and microstructural properties on the other hand were determ...

2009-01-01

183

Characterisation and use of biomass fly ash in cement-based materials  

British Library Electronic Table of Contents (United Kingdom)

This paper presents results about the characterisation of the biomass fly ashes sourced from a thermal power plant and from a co-generation power plant located in Portugal, and the study of new cement formulations incorporated with the biomass fly ashes. The study includes a comparative analysis of the phase formation, setting and mechanical behaviour of the new cement-fly ash formulations based on these biomass fly ashes. Techniques such as X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), thermal gravimetric and differential thermal analysis (TG/DTA), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and environmental scanning electron spectroscopy (ESEM) were used to determine the structure and composition of the formulations. Fly ash F1 from the t...

2009-01-01

184

Vertebroplasty and Kyphoplasty Can Restore Normal Spine Mechanics following Osteoporotic Vertebral Fracture  

UK PubMed Central (United Kingdom)

Osteoporotic vertebral fractures often lead to pain and disability. They can be successfully treated, and possibly prevented, by injecting cement into the vertebral body, a procedure known as vertebroplasty....Full Text Available

185

Pullout behavior of steel fibers from cement-based composites  

Energy Technology Data Exchange (ETDEWEB)

A comprehensive experimental program on pullout tests of steel fibers from cement based matrices is described. A specially designed single fiber pullout apparatus was used to provide a quantitative determination of interfacial properties that are relevant to toughening brittle materials through fiber reinforcement. The parameters investigated included a specially designed high strength cement based matrix called Densified Small Particles system (DSP), a conventional mortar matrix, fiber embedment length, and the fiber volume fraction. The mediums from which the fiber was pulled included a control mortar mix without fibers, a mortar mix with 3, and 6 percent fibers by volume. The results indicate that: (1) the dense DSP matrix has significantly improved interfacial properties as compared to the conventional mortar matrix. (2) Increasing the fiber embedment length and the fiber volume fraction in the cement matrix increase ...

1997-06-01

186

Physico Mechanical Properties of Irradiated Waste Rubber Cement Mortar  

International Nuclear Information System (INIS)

In the present study a partial replacement of aggregate with two different ratios of waste rubber (5%, 10%) with the addition of a constant ratio of rice husk ash (RHA), 5% was carried out. The hardened cement mortar used the optimum water of consistency. The specimens were molded into 1 inch cubic moulds .The specimens were first cured for 24 hours, at 100% relative humidity and then cured under tap water for 3, 7 and 28 days followed by irradiation at different doses of gamma irradiation namely 5 and 10 kGy. The physico-chemical and mechanical properties such as compressive strength, total porosity and bulk density were studied for the three types of specimens. The results showed that the values of the compressive strength, bulk density and chemically combined water of the blended cement mortar paste (OPC-RHA) increase ,while blended cement mortar paste with 5% RHA and 5, 10% waste rubber decrease. The results were ...

187

Mesoscopic failure simulation of cement-based composites; Cement kei fukugo zairyo no junbishiteki hakai katei no suchi simulation  

Energy Technology Data Exchange (ETDEWEB)

An experiment was conducted on the structure of mesoscopic calculating method for cement-based composite materials. The purpose was utilization for the simulation of mesoscale failure processes and the development of new composite materials. Mesh split based on Voronoi polygons was applied as the discrete limit analysis of the cement-based composite materials containing aggregate particles taking the arrangement of random particles into consideration, and a two-dimensional rigid-body/spring model was employed as the model. The nonhomogeneity of concrete was represented by three kinds of different spring parameters which were aggregate, mortar matrix and their interfaces. The simulation results were summarized as follows: The stress-strain curve went into a non-linear state from the 30% of the maximum stress. The generation of interfacial crack started on the side of the aggregate, but the propagation of the crack was stable. Deformation became ...

1995-01-30

188

Influence of temperature on strength of cemented surrogate nitrate salt waste  

Energy Technology Data Exchange (ETDEWEB)

The Rocky Flats Plant (RFP) generates large volumes of a low level aqueous waste stream high in nitrate salts. The aqueous waste is concentrated by evaporation and then mixed with Portland cement prior to transport and disposal. Planned process upgrades include a new horizontal thin film evaporator. Temperature of brine at discharge end of the new evaporator will be near boiling point. Introduction of hot water to cement can degrade the monolithic waste form. However, the RFP salt waste contains high concentrations of compounds known to retard hydration. This paper discusses impact of introducing high temperature waste to cement. The study evaluated three waste compositions: (1) highest probable nitrate composition, (2) highest probable chloride composition, and (3) current composition. Results showed that compressive strength of final waste form increased with brine temperature, and waste forms from brine at the boiling ...

1993-01-01

189

Influence of temperature on strength of cemented surrogate nitrate salt waste  

Energy Technology Data Exchange (ETDEWEB)

The Rocky Flats Plant (RFP) generates large volumes of a low level aqueous waste stream high in nitrate salts. The aqueous waste is concentrated by evaporation and then mixed with Portland cement prior to transport and disposal. Planned process upgrades include a new horizontal thin film evaporator. Temperature of brine at discharge end of the new evaporator will be near boiling point. Introduction of hot water to cement can degrade the monolithic waste form. However, the RFP salt waste contains high concentrations of compounds known to retard hydration. This paper discusses impact of introducing high temperature waste to cement. The study evaluated three waste compositions: (1) highest probable nitrate composition, (2) highest probable chloride composition, and (3) current composition. Results showed that compressive strength of final waste form increased with brine temperature, and waste forms from brine at the boiling ...

1993-03-01

190

Evaluation of red mud as pozzolanic material in replacement of cement for production of mortars; Avaliacao da lama vermelha como material pozolanico em substituicao ao cimento para producao de argamassas  

Energy Technology Data Exchange (ETDEWEB)

Red mud is a by-product of the alkaline extraction of aluminum from the bauxite and represents a renewed environmental problem due the significant annual throughput by the plants. In the present work, the pozzolanic properties of Brazilian red mud fired at 600, 700, 800 and 900 deg C were investigated by monitoring lime consumption using DTA analysis and Brazilian standard methodology NBR 5772 (1992). Products and kinetics of hydration were determined in cement pastes produced with 5 and 15% red mud using x-ray diffraction and DTA analysis. Compressive strength and capillary absorption tests were realized on mortars constituted by 5, 10 and 15% red mud in replacement of cement. When calcined at 600 deg C, the red mud develops good pozzolanic properties, and the compressive strength of mortars produced with this waste meet values in accordance with regulatory standard. These results shown than red mud can be used, in partial replacement of ...

2010-07-01

191

Evaluation of red mud as pozzolanic material in replacement of cement for production of mortars  

International Nuclear Information System (INIS)

Red mud is a by-product of the alkaline extraction of aluminum from the bauxite and represents a renewed environmental problem due the significant annual throughput by the plants. In the present work, the pozzolanic properties of Brazilian red mud fired at 600, 700, 800 and 900 deg C were investigated by monitoring lime consumption using DTA analysis and Brazilian standard methodology NBR 5772 (1992). Products and kinetics of hydration were determined in cement pastes produced with 5 and 15% red mud using x-ray diffraction and DTA analysis. Compressive strength and capillary absorption tests were realized on mortars constituted by 5, 10 and 15% red mud in replacement of cement. When calcined at 600 deg C, the red mud develops good pozzolanic properties, and the compressive strength of mortars produced with this waste meet values in accordance with regulatory standard. These results shown than red mud can be used, in partial replacement of ...

2010-11-21

192

Cement-based composites: Strain rate effects on fracture  

Energy Technology Data Exchange (ETDEWEB)

This book contains over 20 selections. Some of the titles are: Continuum damage mechanics studies on the dynamic fracture of concrete; Dynamic compressive strength of cementitious materials; Rate-sensitivity of mode I and mode II fracture concrete; and An impact damage model of concrete.

1986-01-01

193

Theoretical studies of metal-phosphate interactions: interaction of Li+, Na+, K+, Be++, Mg++, and Ca++ with H2PO4- and (CH3O)2PO2-: implications for nucleic acid solvation.  

UK PubMed Central (United Kingdom)

Model phosphate-metal solvation complexes have been studied by ab-initio self-consistent-field techniques. The complexes studied include (RO)2PO2-(R = H or CH3) with Li+, Na+, K+, Be++, Mg++, Ca++,...Full Text Available

1975-10-01

194

The complete sequence of a full length cDNA for human liver glyceraldehyde-3-phosphate dehydrogenase: evidence for multiple mRNA species.  

UK PubMed Central (United Kingdom)

A recombinant M13 clone (O42) containing a 65 b.p. cDNA fragment from human fetal liver mRNA coding for glyceraldehyde-3-phosphate dehydrogenase has been identified and it has been used to isolate from...Full Text Available

1984-12-11

195

The Isolation and Characterization of d-Glucose 6-Phosphate Cycloaldolase (NAD-Dependent) from Acer pseudoplatanus L. Cell Cultures  

UK PubMed Central (United Kingdom)

A soluble enzyme system from suspension cultures of Acer pseudoplatanus L. converts d-glucose 6-phosphate to myoinositol. A Mg2+-dependent phosphatase, present in...Full Text Available

1971-09-01

196

Synergistic Activation of Glucose-6-Phosphate Dehydrogenase and NAD(P)H oxidase by Src kinase Elevates Superoxide in Type 2 Diabetic, Zucker fa/fa, Rat Liver  

UK PubMed Central (United Kingdom)

Glucose metabolism through glycolysis and hexosamine pathway has been shown to be altered in type 2 diabetes. However, its fate through the pentose phosphate pathway (PPP) is currently unclear....Full Text Available

2009-08-01

197

Silicon effect on corrosion resistance of austenite stainless steels in strongly oxidizing media containing fluoride and phosphate admixtures  

International Nuclear Information System (INIS)

Paper estimates the corrosion resistance and studies the character of dissolving of silicon-bearing austenite stainless steels in strongly oxidizing media containing phosphate and fluoride admixtures. Corrosion behaviour of the studied steels is determined to depend essentially on the content of admixture or alloying silicon, as well as, on their phase composition in many respects determined by the thermal treatment condition. Refs. 22, figs. 1, tabs. 2.

198

D-Glyceraldehyde-3-Phosphate Dehydrogenase: Three-Dimensional Structure and Evolutionary Significance  

UK PubMed Central (United Kingdom)

A 3.0-Å resolution electron density map of lobster glyceraldehyde-3-phosphate dehydrogenase (EC 1.2.1.12) was computed. The essentially single isomorphous replacement map was very substantially...Full Text Available

1973-11-01

199

Structural bonding-breakage constitutive model for natural unsaturated clayey soils  

British Library Electronic Table of Contents (United Kingdom)

The natural clayey soils are usually structural and unsaturated, which makes their mechanical properties quite different from the remolded saturated soils. A structural constitutive model is proposed to simulate the bonding-breakage micro-mechanism. In this model, the unsaturated soil element is divided into a cementation element and a friction element according to the binary medium theory, and the stress-strain coordination for these two elements is obtained. The cementation element is regarded as elastic, whereas the friction element is regarded as elastoplastic which can be described with the Gallipoli?s model. The theoretical formulation is verified with the comparative experiments of isotropic compressions on the saturated and unsaturated structural soils. Parametric analyses of the e...

2010-01-01

200

Corrosion of hardened cement paste by acetic and nitric acids; Part 1: Calculation of corrosion depth  

Energy Technology Data Exchange (ETDEWEB)

The rate of corrosion of hardened cement paste in solutions of nitric, hydrochloric, sulfuric, acetic and formic acids was compared. Corrosion in solutions of acetic and nitric acids with different concentrations was studied in more detail. The results made it possible to obtain the relationships expressing the influence of concentration and the time of action of acid solutions on the depth of corrosion. The rates of corrosion in nitric acid solutions during the first 3 years were about 2 to 4 times that in acetic acid solutions, depending on the concentration.

1994-01-01

201

Application of fracture mechanics to cementitious composites  

Energy Technology Data Exchange (ETDEWEB)

This work contains 27 chapters which cover recent advances in fracture mechanics applied to cement-based composites: concrete, reinforced concrete, and fiber reinforced concrete. The book, based on a NATO Advanced Study Institute, is a comprehensive survey of treating nonlinearity associated with crack growth in brittle materials such as cement composites, rocks and ice. The book is divided into 8 major themes: advances in nonlinear fracture mechanics; fracture processes; numerical modelling of fracture; experimental methods of determining fracture parameters; damage and continuum modelling; strain-rate and dynamic effects of crack propagation; stress-corrosion, time and temperature effects on fracture; and implications for concrete structures.

1985-01-01

202

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

Energy Technology Data Exchange (ETDEWEB)

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

1991-12-31

203

Method of treating final products from flue gas desulfurization  

Science.gov (United States)

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

1984-10-23

204

Microbial degradation of low-level radioactive waste. Final report  

Energy Technology Data Exchange (ETDEWEB)

The Nuclear Regulatory Commission stipulates in 10 CFR 61 that disposed low-level radioactive waste (LLW) be stabilized. To provide guidance to disposal vendors and nuclear station waste generators for implementing those requirements, the NRC developed the Technical Position on Waste Form, Revision 1. That document details a specified set of recommended testing procedures and criteria, including several tests for determining the biodegradation properties of waste forms. Information has been presented by a number of researchers, which indicated that those tests may be inappropriate for examining microbial degradation of cement-solidified LLW. Cement has been widely used to solidify LLW; however, the resulting waste forms are sometimes susceptible to failure due to the actions of waste constituents, stress, and environment. The purpose of this research program was to develop modified microbial degradation test procedures that would be more ...

1996-06-01

205

High volume fly ash RCC for dams - I : mixture optimization and mechanical properties  

Energy Technology Data Exchange (ETDEWEB)

Roller compacted concretes (RCC) were developed for the Norwegian Skjerka hydropower project. RCCs were developed to have a high-volume fly ash content to address environmental issues, including the reduction of carbon dioxide emissions associated with dam construction. They also makes good use of waste product and conserve natural resources. This study examined a series of mixtures to determine the appropriateness of using RCC as a competing alternative to the traditional rock fill dam proposed for the Skjerka hydropower project. The main advantage of RCC is speed, allowing a relatively large dam to be constructed in just one summer season, saving financial costs and providing early return on the investment. In addition, fly ash can be used in the structure, using clean and renewable energy. Several procedures to proportion RCC mixtures were proposed, including the optimal paste volume method which is based on the assumption that an optimal RCC should have just enough paste to fill ...

2001-07-01

206

Burial dissolution and dolomitization relationships to moldic, stylolite and fracture porosity in the Cretaceous Sunniland Formation rudistid carbonate reservoir facies, Florida  

Energy Technology Data Exchange (ETDEWEB)

Cretaceous Sunniland Formation rudistid reservoir facies buried at 3,520 meters (92 C) between evaporite units contain marginally mature algal sapropelic carbonate source rock hydrocarbons. The closed system aids in identification of porosity redistribution related to hydrocarbon emplacement. Multiple dissolution and cementation events associated with hydrocarbon migration pulses are particularly evident along stylolites. Corrosion usually predates typically interparticle first generation saddle dolomite, and corroded saddle dolomite may be observed with two generations of optically continuous limpid overgrowths separated by a corrosive boundary. Dissolution or dedolomitization may provide a magnesium source for subsequent dolomite cements. Carbonic and organic acids are probable primary corrosive agents. Moldic, stylolite and fracture porosity, often reduced by dolomite cements, was generated. Moldic pores may develop from ...

1994-03-01

207

Evaluation of influence of fertilizers in radium concentration from tomato culture; Avaliacao da influencia dos fertilizantes nos teores de radio encontrados na cultura do tomate  

Energy Technology Data Exchange (ETDEWEB)

The fertilizer contribution to radio uptake by tomato plants was assessed. Tomato and soil samples from four different plantations were analyzed: two using organic fertilizer and two using phosphate fertilizer. The Ra concentrations in eight of the most used tomato fertilizers were determined. The concentration values ranged from 14 to 221 Bq/kg of Ra-226 and from 25 to 176 Bq/kg of Ra-228. Owing to the low Ra concentration and to the used fertilizer quantities, the fertilizers would not increase significantly the Ra soil concentration. However, the highest soil to plant concentration ratios were found in the plantations using phosphate fertilizers. This outcome pointed out the higher Ra availability in the phosphate fertilizer plantations than in the organic fertilizer plantations, showing a possible positive influence of phosphate fertilizers for the tomato Ra uptake. Due to the ...

2001-07-01

208

Wet limestone FGD solids analysis by thermogravimetry  

Energy Technology Data Exchange (ETDEWEB)

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

2004-07-01

209

Vitamin D and respiratory health  

UK PubMed Central (United Kingdom)

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

2009-10-01

210

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

British Library Electronic Table of Contents (United Kingdom)

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

2010-01-01

211

Transformation of Verapamil by Cunninghamella blakesleeana  

UK PubMed Central (United Kingdom)

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

2004-05-01

213

Role of temperature in the spontaneous precipitation of calcium sulfate dihydrate  

Energy Technology Data Exchange (ETDEWEB)

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

1999-02-16

214

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

British Library Electronic Table of Contents (United Kingdom)

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

2011-01-01

215

Loss of Skeletal Calcium by Patients on Maintenance Dialysis  

UK PubMed Central (United Kingdom)

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

1970-08-29

216

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

International Nuclear Information System (INIS)

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

217

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

Science.gov (United States)

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

1986-01-01

218

Effects of compost and phosphate amendments on arsenic mobility in soils and arsenic uptake by the hyperaccumulator, Pteris vittata L  

International Nuclear Information System (INIS)

Chinese brake fern (Pteris vittata L.), an arsenic (As) hyperaccumulator, has shown the potential to remediate As-contaminated soils. This study investigated the effects of soil amendments on the leachability of As from soils and As uptake by Chinese brake fern. The ferns were grown for 12 weeks in a chromated-copper-arsenate (CCA) contaminated soil or in As spiked contaminated (ASC) soil. Soils were treated with phosphate rock, municipal solid waste, or biosolid compost. Phosphate amendments significantly enhanced plant As uptake from the two tested soils with frond As concentrations increasing up to 265% relative to the control. After 12 weeks, plants grown in phosphate-amended soil removed >8% of soil As. Replacement of As by P from the soil binding sites was responsible for the enhanced mobility of As and subsequent increased plant uptake. Compost additions facilitated As uptake from the CCA soil, but decreased As ...

2003-11-01

219

Effect of radiation on some prepared polymeric moulds for use in environmental applications  

International Nuclear Information System (INIS)

The aim of this study is to prepare some polymeric moulds using Natural rubber latex (NRL)- portland cement composites based on a delayed-action mechanism. Factors affecting the preparation process such as concentration, mixing percentage, additives and their effects on what is regarded as a delayed-action coacervant combination was studied. The effect of Gamma-radiation on the mechanical properties of these moulds was investigated. The effect of natural aging on the prepared moulds was investigated to determine the possibility of using the prepared product in the construction field as expansion joints and cracks filling materials ...etc. The results may be summarized as follows: 1) Composites of natural rubber latex (NRL)-portland cement mould were prepared as two separate parts. The stabilized natural rubber latex (NRL) with hydroxy ethyl cellulose (HEC) as stabilizer and a delayed-action coacervant (sodium meta silicate) present in the ...

220

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

UK PubMed Central (United Kingdom)

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

2011-04-08

221

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

Energy Technology Data Exchange (ETDEWEB)

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

1986-07-01

222

Tungsten Effects on Phosphate-Dependent Biochemical Pathways are Species and Liver Cell Line Dependent  

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...

2010-01-01

223

Physicochemical investigation of the behavior of elements in chloride melts in the presence of solid phases based on phosphates of polyvalent elements. II. Behavior of strontium and barium  

Energy Technology Data Exchange (ETDEWEB)

The distribution of the alkaline earth elements strontium and barium between the solid phases of phosphates of transition elements of group 4 and chloride melts was studied. The distribution coefficients of strontium and barium were found at T = 700-800/sup 0/C. Phosphates of the type NaM/sub 2//sup (IV)/(PO/sub 4/)/sub 3/, where M/sub (IV)/ represents titanium, zirconium, and hafnium, were used as the solid phases. It was established that there is an enrichment of the precipitates with the distributed components. The distribution coefficient depends on the nature of the solid phase and the temperature. It was suggested that M/sup (II)/ x M/sub 4//sup (IV)/(PO/sub 4/)/sub 6/ is formed in processes of distribution, where M/sup (II)/ represents Sr, Ba.

1987-07-01

224

Effects of hydrous pyrolysis on biomarker thermal maturity parameters: Monterey Phosphatic and Siliceous members  

Energy Technology Data Exchange (ETDEWEB)

Hydrous pyrolysis of immature Monterey Phosphatic or Siliceous rock at progressively higher temperatures causes systematic changes in biomarker thermal maturity parameters of the generated hydrocarbons. Biomarker ratios based on proposed carbon-carbon cracking or aromatization reactions increase during hydrous pyrolysis along similar pathways for both Siliceous and Phosphatic members. An increase in these biomarker ratios is also observed for oils of increasing thermal maturity from the offshore Santa Maria Basin, although the rates of changes for each parameter differ between the hydrous pyrolysis and natural samples. Changes in some cracking parameters during maturation appear to result from differential thermal stability of the compounds rather than conversion of precursors to products. (author).

1990-01-01

225

Ectopic mineralization of connective tissue in Abcc6-/- mice: effects of dietary modifications and a phosphate binder - a preliminary study  

British Library Electronic Table of Contents (United Kingdom)

Please cite this paper as: Ectopic mineralization of connective tissue in Abcc6-/- mice: effects of dietary modifications and a phosphate binder - a preliminary study. Experimental Dermatology 2008; 17: 203-207. Abstract: Pseudoxanthoma elasticum (PXE), a heritable multisystem disorder, is caused by mutations in the ABCC6 gene. We have developed a murine model for PXE by targeted inactivation of the corresponding mouse gene. A feature of this mouse model is ectopic mineralization of connective tissue capsule surrounding the bulb of vibrissae. This study was designed to investigate the effect of dietary sevelamer hydrochloride (Renagel), a phosphate binder, and specific mineral modifications on ectopic mineralization of connective tissue in Abcc6-/- mice. Three groups were fed a specific di...

2008-01-01

226

Comparison of sodium zirconium phosphate-structured HLW forms and synroc for high-level nuclear waste immobilization  

Energy Technology Data Exchange (ETDEWEB)

The incorporation of (a) Cs/Sr as simulated heat-generating isotopes contained in Purex reprocessing waste, (b) simulated actinides, and (c) simulated Purex waste in sodium zirconium phosphate (NZP) has been studied. The samples were prepared by sintering, by hot pressing and by hot isostatic pressing in metal bellows containers. The short-term chemical durability of the phosphate-based material containing Purex waste was within an order of magnitude of that for Synroc-C, as measured by 7-day MCC-1 tests at 90{degrees}C. The dissolution behavior showed evidence of re-precipitation phenomena, even after times as short as 28 days. Potential for improvement of NZP-based ceramics for HLW management is discussed. 19 refs., 4 figs., 3 tabs.

1996-12-31

227

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

Energy Technology Data Exchange (ETDEWEB)

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

2003-11-01

228

Biosorption of Acid Blue 25 by unmodified and CPC-modified biomass of Penicillium YW01: Kinetic study, equilibrium isotherm and FTIR analysis  

British Library Electronic Table of Contents (United Kingdom)

The main objective of this work was to investigate the biosorption performance of unmodified and Cetylpyridinium chloride (CPC)-modified biomass of Penicillium YW 01 for Acid Blue 25 (AB 25). Maximum biosorption capacity of AB 25 onto CPC-modified biosorbent was 118.48mgg^-^1 under phosphoric-phosphate buffer with initial dye concentration of 200mgL^-^1 at 30^oC. The biosorption pattern of AB 25 onto unmodified biosorbent in aqueous solution and phosphoric-phosphate buffer was well fitted with both Langmuir and Freundlich isotherm models. While the equilibrium data of CPC-modified biosorbent in aqueous solution and phosphoric-phosphate buffer failed to fit the Freundlich isotherm model, indicating the monolayer biosorption formed onto CPC-modified biosorbent. The values of initial biosorpt...

2011-01-01

229

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

Energy Technology Data Exchange (ETDEWEB)

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

1981-10-01

230

Human complement protein C99 is a calcium binding protein  

International Nuclear Information System (INIS)

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

231

The characteristics of a hydroxyapatite-chitosan-PMMA bone cement.  

Science.gov (United States)

In this study, we propose a new bioactive bone cement (BBC), composed of natural bone powder (hydroxyapatite; HA), chitosan powder, and the currently available polymethylmethacrylate (PMMA) bone cement, for use in orthopedic surgeries such as vertebroplasty or as bone filler. Three types of BBCs (BBC I, BBC II, and BBC III) were prepared with different composition ratios. In vitro tests and animal studies were performed with the new BBCs, and with a currently available commercial PMMA bone cement. Surface morphology, chemical composition, changes in pH over time, exothermic temperatures, intrusion, and cellular responses were investigated in vitro. Scanning electron microscopy (SEM) and radiological and histological examinations were performed in animal studies. The results showed that the major components of the BBCs were C, O, Ca, P, Cl, Si, S, Ba, and Mg. The pH values of the BBCs decreased after 1 day, but eventually ...

2004-11-01

232

Study on immobilizing radioactive slurry based on alkali-activated slag-clay minerals composite cement  

International Nuclear Information System (INIS)

The feasibility of immobilizing simulated radioactive slurry (SRS) by alkali-activated slag---clay minerals composite cement (AASCM) was studied under the experimental conditions. The results show that the dosage of SRS and water cement ratio (W/C) have significant effect on the flowability of the mixture of AASCM and SRS. The more dosage of SRS, the lower flowability. When cement/sand ratio is 1: 1 and W/C is 0.45, the flowability of the mixture meets the case of solidification engineering and the compressive strength of the waste forms containing 20% SRS meets the needs of GB 14569.1-93. The setting time of the mixture of AASCM and SRS is highly dependent on temperature while sorts of anions have little influence on it. The application of AASCM is suitable below 20 degree C. The leaching resistance of AASCM based waste forms is superior to that of OPC based waste forms. The control of the forms to Sr2+ is stronger than ...

2006-03-01

233

Microbial degradation of low-level radioactive waste. Volume 2, Annual report for FY 1994  

Science.gov (United States)

The Nuclear Regulatory Commission stipulates in 10 CFR 61 that disposed low-level radioactive waste (LLW) be stabilized. To provide guidance to disposal vendors and nuclear station waste generators for implementing those requirements, the NRC developed the Technical Position on Waste Form, Revision 1. That document details a specified set of recommended testing procedures and criteria, including several tests for determining the biodegradation properties of waste forms. Cement has been widely used to solidify LLW; however, the resulting waste forms are sometimes susceptible to failure due to the actions of waste constituents, stress, and environment. The purpose of this research program is to develop modified microbial degradation test procedures that will be more appropriate than the existing procedures for evaluating the effects of microbiologically influenced chemical attack on cement-solidified LLW. Groups of microorganisms indigenous to ...

1995-08-01

234

Calibration curves of a PGNAA system for cement raw material analysis using the MCNP code  

Energy Technology Data Exchange (ETDEWEB)

In large samples, the {gamma}-ray count rate of a prompt gamma neutron activation analysis system is a multi-variable function of the elemental dry composition, density, water content and thickness of the material. The experimental calibration curves require tremendous laboratory work, using a great number of standards with well-known compositions. Although a Monte Carlo simulation study does not avoid the experimental calibration work, it reduces the number of experimental calibration standards. This paper is part of a feasibility study for a PGNAA system for on-line continuous characterisation of cement raw material conveyed on a belt (Oliveira, C., Salgado, J. and Carvalho, F. G. (1997) Optimisation of PGNAA instrument design for cement raw materials using the MCNP code. J. Radioanal. Nucl. Chem. 216(2), 191-198; Oliveira, C., Salgado, J., Goncalves, I. F., Carvalho, F. G. and Leitao, F. (1997a) A Monte Carlo study of the influence of ...

1998-12-01

235

Achievement report in fiscal 2000. Model project to reduce electric power consumption at cement burning plant; 2000 nendo seika hokoku. Semento shosei plant denryoku shohi sakugen model jigyo  

Energy Technology Data Exchange (ETDEWEB)

In order to serve for efficient energy utilization and environmental improvement in the Republic of Vietnam, a 'Model project to reduce electric power consumption at cement burning plant' has been implemented. This paper summarizes the achievements. This project is intended to add an advanced, matured and reliable electric power generation facility using cement waste heat to the existing cement plant in Vietnam to produce steam and generate power by utilizing the waste heat generated from the preheating process in the burning plant. The present project has performed the detailed designing on the piping, electric facilities and instrumentation based on the basic agreement on the project. Fabrication of the piping has been executed by the Vietnam side. Valves and electric devices were procured and transported, including those fabricated in the previous fiscal year. Technology guiding personnel were sent for ...

2002-03-01

236

A simplified method of opacifying and mixing acrylic cement for percutaneous vertebroplasty: a clinical and in vitro study.  

Science.gov (United States)

The objective of this study was to simplify the opacifying mixing process of the bone cement and contrast used for percutaneous vertebroplasty (PVP). We performed a biomechanical study of polymethyl methacrylate (PMMA) (Corinplast 3) using three different mixtures of PMMA, monomer, and contrast: group I, 2:1; group II, 3:2; group III, 3:2:1 ratio of powder/monomer/iodinated contrast (Omnipaque). In vitro biomechanical testing of ultimate compressive strength was carried out in all samples. Following the conclusion of a proper bone cement mixture regimen drawn from the in vitro study, PVP was performed in 125 patients: 58 with cancer, 12 with hemangioma, and 54 with osteoporotic fracture. The ultimate compressive strength in group III was decreased by 38% compared to groups II and I. Proper fluoroscopic visualization was achieved in all PVP procedures using this mixture. There were no major complications associated with injection of the ...

237

A Simplified Method of Opacifying and Mixing Acrylic Cement for Percutaneous Vertebroplasty: A Clinical and In Vitro Study  

Science.gov (United States)

The objective of this study was to simplify the opacifying mixing process of the bone cement and contrast used for percutaneous vertebroplasty (PVP). We performed a biomechanical study of polymethyl methacrylate (PMMA) (Corinplast{sup TM} 3) using three different mixtures of PMMA, monomer, and contrast: group I, 2:1; group II, 3:2; group III, 3:2:1 ratio of powder/monomer/iodinated contrast (Omnipaque). In vitro biomechanical testing of ultimate compressive strength was carried out in all samples. Following the conclusion of a proper bone cement mixture regimen drawn from the in vitro study, PVP was performed in 125 patients: 58 with cancer, 12 with hemangioma, and 54 with osteoporotic fracture. The ultimate compressive strength in group III was decreased by 38% compared to groups II and I. Proper fluoroscopic visualization was achieved in all PVP procedures using this mixture. There were no major complications associated with injection of the ...

2005-06-15

238

skittles, a Drosophila phosphatidylinositol 4-phosphate 5-kinase, is required for cell viability, germline development and bristle morphology, but not for neurotransmitter release.  

UK PubMed Central (United Kingdom)

The phosphatidylinositol pathway is implicated in the regulation of numerous cellular functions and responses to extracellular signals. An important branching point in the pathway is the phosphorylation...Full Text Available

1998-12-01

239

Use of Dimethyl Suberimidate, a Cross-Linking Reagent, in Studying the Subunit Structure of Oligomeric Proteins*  

UK PubMed Central (United Kingdom)

Amidination of aldolase, glyceraldehyde-3-phosphate dehydrogenase, tryptophan synthetase B protein, L-arabinose isomerase, and the catalytic subunit of E. coli aspartate transcarbamylase...Full Text Available

1970-07-01

240

The effect of lecithin on intestinal cholesterol uptake by rat intestine in vitro  

UK PubMed Central (United Kingdom)

1. Sacs 20 cm long were obtained from the upper half of the small intestine of bile fistula rats (bile duct cannulated 48 hours previously). The sacs were everted, filled with oxygenated phosphate...Full Text Available

1973-03-01

241

The control of sulphate reduction in bacteria  

UK PubMed Central (United Kingdom)

1. An enzyme from Escherichia coli 9723 that reduces adenosine 3′-phosphate 5′-sulphatophosphate to inorganic sulphite is described. Extracts of E. coli...Full Text Available

1965-07-01

242

The Structure of Sucrose Phosphate Synthase from Halothermothrix orenii Reveals Its Mechanism of Action and Binding Mode  

Energy Technology Data Exchange (ETDEWEB)

Sucrose phosphate synthase (SPS) catalyzes the transfer of a glycosyl group from an activated donor sugar, such as uridine diphosphate glucose (UDP-Glc), to a saccharide acceptor D-fructose 6-phosphate (F6P), resulting in the formation of UDP and D-sucrose-6'-phosphate (S6P). This is a central regulatory process in the production of sucrose in plants, cyanobacteria, and proteobacteria. Here, we report the crystal structure of SPS from the nonphotosynthetic bacterium Halothermothrix orenii and its complexes with the substrate F6P and the product S6P. SPS has two distinct Rossmann-fold domains with a large substrate binding cleft at the interdomain interface. Structures of two complexes show that both the substrate F6P and the product S6P bind to the A-domain of SPS. Based on comparative analysis of the SPS structure with other related enzymes, the donor substrate, nucleotide diphosphate glucose, binds to the ...

2008-01-01

243

Targeting the Pentose Phosphate Pathway in Syndrome X-related Cardiovascular Complications  

UK PubMed Central (United Kingdom)

Syndrome X is a combination or co-occurrence of several known cardiovascular risk factors (including central obesity, dyslipidemias, fatty liver disease, hyperinsulinemia, insulin resistance,...Full Text Available

2010-05-01

244

Regulation of lactose catabolism in Streptococcus mutans: purification and regulatory properties of phospho-beta-galactosidase.  

UK PubMed Central (United Kingdom)

Phospho-beta-galactosidase (P-beta-gal), the enzyme which catalyzes the first step in the metabolism of intracellular lactose phosphate, occurred at high specific activity in the cytoplasm in 12 of...Full Text Available

1979-01-01

245

PGM2 overexpression improves anaerobic galactose fermentation in Saccharomyces cerevisiae  

UK PubMed Central (United Kingdom)

BackgroundIn Saccharomyces cerevisiae galactose is initially metabolized through the Leloir pathway after which glucose 6-phosphate enters glycolysis. Galactose...Full Text Available

246

Nitrogen metabolite repression of nitrate reductase in Neurospora crassa.  

UK PubMed Central (United Kingdom)

The effect of different nitrogen compounds on the induction of reduced nicotinamide adenine dinucleotide phosphate-nitrate reductase was examined in Neurospora crassa. Whereas in the wild-type strain...Full Text Available

1979-03-01

247

Method for inhibiting fouling of petrochemical processing equipment  

Energy Technology Data Exchange (ETDEWEB)

Method for inhibiting the formation of foulants on petrochemical equipment which involves adding to the petrochemical, during processing, a composition comprising a thiodipropionate and either a dialkyl acid phosphate ester or a dialkyl acid phosphite ester.

1980-10-07

248

Method for determining the temporal response of microbial phosphate transport affinity.  

UK PubMed Central (United Kingdom)

Nutrient transport affinities of nutrient-starved microbial populations were measured as initial slopes of plots of limiting-nutrient transport rates versus extracellular limiting-nutrient concentrations....Full Text Available

1986-03-01

249

Lipid A biosynthesis in Rhizobium leguminosarum: Role of a 2-keto-3-deoxyoctulosonate-activated 4{prime} phosphatase  

Energy Technology Data Exchange (ETDEWEB)

Lipid A from several strains of the N{sub 2}-fixing bacterium Rhizobium leguminosarum displays significant structural differences from Escherichia coli lipid A, one of which is the complete absence of phosphate groups. However, the first seven enzymes of E. coli lipid A biosynthesis, leading from UDP-GlcNAc to the phosphorylated intermediate, 2-keto-3-deoxyoctulosonate (Kdo{sub 2})-lipid IV{sub A}, are present in R. leguminosarum. We now describe a membrane-bound phosphatase in R. leguminosarum extracts that removes the 4{prime} phosphate of Kdo{sub 2}-lipid IV{sub A}. The 4{prime} phosphatase is selective for substrates containing the Kdo domain. It is present in extracts of R. leguminosarum biovars phaseoli, viciae, and trifolii but is not detectable in E. coli and Rhizobium meliloti. A nodulation-defective strain (24AR) of R. leguminosarum bovar trifolii, known to contain a 4{prime} phosphate residue on its lipid A, also ...

1995-08-01

250

Formate Dehydrogenase of Clostridium thermoaceticum: Incorporation of Selenium-75, and the Effects of Selenite, Molybdate, and Tungstate on the Enzyme  

UK PubMed Central (United Kingdom)

The formation of the nicotinamide adenine dinucleotide phosphate-dependent formate dehydrogenase in Clostridium thermoaceticum is stimulated by the presence of molybdate and selenite...Full Text Available

1973-11-01

251

Carbon Partitioning in Eelgrass (Regulation by Photosynthesis and the Response to Daily Light-Dark Cycles).  

UK PubMed Central (United Kingdom)

Diel variations in rates of C export, sucrose-phosphate synthase (SPS) and sucrose synthase (SS) activity, and C reserves were investigated in Zostera marina L. (eelgrass) to elucidate the environmental...Full Text Available

1995-08-01

252

A proton nuclear magnetic resonance investigation of the anion Bohr effect of human normal adult hemoglobin  

International Nuclear Information System (INIS)

High-resolution proton nuclear magnetic resonance spectroscopy has been used to investigate the molecular mechanism of the Bohr effect of human normal adult hemoglobin in the presence of two allosteric effectors, i.e., chloride and inorganic phosphate ions. The individual hydrogen ion equilibria of 22-26 histidyl residues of hemoglobin have been measured in anion-free 0.1 M HEPES buffer and in the presence of 0.18 M chloride or 0.1 M inorganic phosphate ions in both deoxy and carbonmonoxy forms. The results indicate that the #beta#2-histidyl residues are strong binding sites for chloride and inorganic phosphate ions in hemoglobin. The affinity of the #beta#2-histidyl residues for these anions is larger in the deoxy than in the carbonmonoxy form. Nevertheless, the contribution of these histidyl residues to the anion Bohr effect is small due to their low pK value in deoxyhemoglobin in anion-free solvents. The interactions of ...

253

Process of making particle board from pyrophosphate treated polyisocyanates  

Energy Technology Data Exchange (ETDEWEB)

A process is disclosed for the preparation of liquid, storage-stable, polyisocyanate compositions containing a release agent formed in situ which compositions are useful, for example, as binder resins in the formation of particle boards which latter, because of the presence of the release agent, show no tendency to adhere to the face of metal platens used in their formation. The process comprises heating an organic polyisocyanate (polymethylene polyphenyl polyisocyanate preferred) with an acid phosphate (e.g. a mixture of mono-and di-alkyl acid phosphates) under conditions controlled as to time and temperature so as to yield a product which is storage stable and shows no tendency to deposit solid or to separate into two liquid phases.

1984-10-09

254

Moessbauer spectroscopy study of iron corrosion underneath painting system  

International Nuclear Information System (INIS)

The effect of pigments on the development of corrosion products between the painting system and metal surface when exposed to marine environments has been discussed. The pigments studied were: red mud zinc chromate, zinc chromate, red oxide zinc phosphate, manganese phosphate barium chromate and basic lead silico chromate. Moessbauer spectroscopy revealed that the upper rust layer in all the cases consisted of #gamma#-Fe_2O_3, #gamma#-FeOOH and #alpha#-FeOOH. The lower rust layer immediately in contact with the metal surface consisted of an asymmetrical doublet due to #gamma#-FeOOH. (Auth.).

255

Extraction of magnesium as the iodide by tributyl phosphate  

Science.gov (United States)

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

1987-08-20

256

Crystal structure of telluric acid ammonium phosphate (TAAP) in the paraelectric phase  

Energy Technology Data Exchange (ETDEWEB)

Crystal structure of monoclinic telluric acid ammonium phosphate (TAAP) has been studied by an X-ray diffraction method in the paraelectric phase at 333 K and in the ferroelectric phase at room temperature. It is confirmed that the space group in the paraelectric phase is P2/n. Comparison of the results between the two temperatures suggests that the plane which is made by the PO{sub 4} tetrahedron linked by hydrogen bonds has an important role for the ferroelectric phase transition. This plane is almost parallel to the direction of spontaneous polarization.

2005-01-15

257

Thermally conductive cementitious grouts for geothermal heat pumps. Progress report FY 1998  

Energy Technology Data Exchange (ETDEWEB)

Research commenced in FY 97 to determine the suitability of superplasticized cement-sand grouts for backfilling vertical boreholes used with geothermal heat pump (GHP) systems. The overall objectives were to develop, evaluate and demonstrate cementitious grouts that could reduce the required bore length and improve the performance of GHPs. This report summarizes the accomplishments in FY 98. The developed thermally conductive grout consists of cement, water, a particular grade of silica sand, superplasticizer and a small amount of bentonite. While the primary function of the grout is to facilitate heat transfer between the U-loop and surrounding formation, it is also essential that the grout act as an effective borehole sealant. Two types of permeability (hydraulic conductivity) tests was conducted to evaluate the sealing performance of the cement-sand grout. Additional properties of the proposed grout that were ...

1998-11-01

258

Safety evaluation methodology of engineering barriers at repository for low and intermediate level radioactive waste  

International Nuclear Information System (INIS)

Analyses of the roles of cement-based barriers in radioactive waste isolation show that models used to estimate their characteristics during the lifetime of the repository must consider the alteration of material properties with time due to degradation processes. Reinforced concrete barriers at repositories shall be designed in such manner that they fulfil besides isolative capabilities also the required functions of mechanical resistance and stability. Key elements of safety evaluation are mainly the correct selection of materials for mineral composites with cement binder (cements, aggregates, mineral additives and chemical admixtures) and their design, execution of construction works and production of precast concrete containers (continuous casting of concrete - no cold joints, limited number of construction joints, proper placing and consolidation, finishing and curing), strict control of used materials and inspection of ...

2007-09-10

259

Pore size distribution, strength, and microstructure of portland cement paste containing metal hydroxide waste  

Energy Technology Data Exchange (ETDEWEB)

Stabilization/solidification of hazardous wastes is used to convert hazardous metal hydroxide waste sludge into a solid mass with better handling properties. This study investigated the pore size development of ordinary portland cement pastes containing metal hydroxide waste sludge and rice husk ash using mercury intrusion porosimetry. The effects of acre and the addition of rice husk ash on pore size development and strength were studied. It was found that the pore structures of mixes changed significantly with curing acre. The pore size shifted from 1,204 to 324 {angstrom} for 3-day old cement paste, and from 956 to 263 {angstrom} for a 7-day old sample. A reduction in pore size distribution for different curing ages was also observed in the other mixtures. From this limited study, no conclusion could be made as to any correlation between strength development and porosity. 10 refs., 6 figs., 3 tabs.

1996-12-31

260

EB-curing of coatings on wood composite boards  

International Nuclear Information System (INIS)

The industrial radiation processing using low energy electron beam (EB) accelerators lower than 300 keV offers high speed, safe technologies for the chemical conversion of thin layer coatings. Because of the nonselective mode of initiating chain reaction polymerization involving free radicals in synthetic coating layers and suitable substrates, the EB curing of the coatings on woods and papers has particular advantage. Hungary decided to start an up-to-date EB line to process cement-bound (CB) wood chipboards with pigmented acrylic coatings. The CB wood chipboards contain more than 60 % of portland cement and up to 40 % of wood particles. They are produced as large boads of 6 - 16 mm thickness. In their fireproof character and other aspects, they are similar to asbestos-cement boards without containing carcinagenic asbestos, and are stable against moisture and atmospheric influences. EB-cured acrylate coating improved ...

1988-10-01

261

Structural definition of the active site and catalytic mechanism of 3,4-dihydroxy-2-butanone 4-phosphate synthase  

Energy Technology Data Exchange (ETDEWEB)

X-ray crystal structures of L-3,4-dihydroxy-2-butanone-4-phosphate synthase from Magnaporthe grisea are reported for the E-SO{sub 4}{sup 2-}, E-{sub 4}{sup 2-}-Mg{sup 2+}, E-SO{sub 4}{sup 2-}-Mn{sup 2+}, E-SO{sub 4}{sup 2-}-Mn{sup 2+}-glycerol, and E-SO{sub 4}{sup 2-}-Zn{sup 2+} complexes with resolutions that extend to 1.55, 0.98, 1.60, 1.16, and 1.00 {angstrom}, respectively. Active-site residues of the homodimer are fully defined. The structures were used to model the substrate ribulose 5-phosphate in the active site with the phosphate group anchored at the sulfate site and the placement of the ribulose group guided by the glycerol site. The model includes two Mg{sup 2+} cations that bind to the oxygen substituents of the C2, C3, C4, and phosphate groups of the substrate, the side chains of Glu37 and His153, and water molecules. The position of the metal cofactors and the substrate's ...

2010-03-08

262

Effects of pH and phosphate on metal distribution with emphasis on As speciation and mobilization in soils from a lead smelting site  

Energy Technology Data Exchange (ETDEWEB)

Arsenic in soils from the Asarco lead smelter in East Helena, Montana was characterized by X-ray absorption spectroscopy (XAS). Arsenic oxidation state and geochemical speciation were analyzed as a function of depth (two sampling sites) and surface distribution. These results were compared with intensive desorption/dissolution experiments performed in a pH stat reactor for samples from the site with the highest degree of As heterogeneity. The objectives of the study were to investigate the solid-phase geochemical As speciation, assess the speciation of As in solutions equilibrated with the solids under controlled pH (pH=4 or 6) and Eh (using hydrogen or air) environments, observe the effects of phosphate on the release of As into solution, and examine the effects of phosphate on metal mobility in the systems. Arsenic was predominantly found in the As(V) valence state, though there was evidence that As(III) and As(0) were present also. The ...

2005-06-01

263

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

Science.gov (United States)

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

2007-12-14

264

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

International Nuclear Information System (INIS)

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

265

Proceedings of the 8. CANMET/ACI international conference on superplasticizers and other chemical admixtures in concrete[ACI SP-239  

Energy Technology Data Exchange (ETDEWEB)

This international conference brought together representatives from industry, academia and government agencies to present the latest developments on the subject of chemical admixtures and superplasticizers in concrete. Recent technological advances in the development of superplasticizers were reviewed, as well as new approaches to manufactured aggregates. The influence of new materials on the rheology of cement systems was discussed, as well as the influence of superplasticizers on various types of aggregates. The addition of hydrophobic admixtures in corrosion prevention strategies were reviewed. Various interactions between cements and superplasticizers were evaluated. Issues concerning adsorption and concrete materials were also investigated. A total of 70 papers were presented at the conference, of which 3 have been catalogued separately for inclusion in this database. refs., tabs., figs.

2006-07-01

266

New wear resistant composite material  

Energy Technology Data Exchange (ETDEWEB)

A composite material consisting of WC-Co particles in a steel matrix was fabricated by sintering mixtures of WC-Co particles and a steel powder and infiltrating the sintered pieces with a copper alloy. Its wear resistance and mechanical properties were studied as a function of the content in WC-Co particles and other characteristics of the composite material microstructure. Infiltration provided a simple means to obtain a strong cohesion between WC-Co particles and the steel matrix. An effective matrix protection against wear is obtained with relatively low additions of particles especially with a silica abrasive which is soft with respect to cemented carbide. The experimental results show that this material has good mechanical properties and wear resistance. Depending upon abrasion resistance, wear losses are reduced up to 10 times by a 30 vol% addition of cemented carbide particles.

1983-01-01

267

Experimental modelling of thermal consolidation effects around a high level waste repository  

International Nuclear Information System (INIS)

This report summarizes the results of a research programme which involves the development of a laboratory experimental facility for the simulation and study of hydro-thermo-mechanical processes in saturated geomaterials with low permeability. The experimentation involves a synthetic cement based porous material made of cement grout which possesses permeabilities in the range of dense unfractured sandstones or shale. Specially manufactured pore-pressure transducers were installed within the cylindrical block at locations adjacent to a plane free boundary. The block was saturated with the periodic application of a vacuum. In its saturated state the plane boundary of the block was subjected to heating via a circular heater the temperature of which was maintained constant. The resulting pore pressure generation along with temperature at these locations was monitored continuously. The results of a series of experiments are documented and further ...

268

Diagenesis and porosity development in the carbonate reservoirs in the Ordovician Majiagou Formation, northern Ordos Basin, China  

Energy Technology Data Exchange (ETDEWEB)

The carbonate rocks of the Lower Ordovician Majiagou Formation represent important hydrocarbon reservoirs in the Ordos basin in the western part of the North China plate. Cores and thin sections from more than 60 wells were examined. The main reservoir in the Majiagou Formation consists of fine crystalline dolomite, which was altered by meteoric water during an extended subaerial exposure. Three phreatic zones have been identified in the Majiagou Formation in the northern part of the basin. Oxygen isotopes and fluid inclusion microthermometry data indicates that the porosity developed during the early karst event was considerably reduced by the late-stage, coarse crystalline calcite cements that appear to be related to hydrothermal fluids during deep burial. It was concluded that the main factors that determine the porosity and permeability of these carbonate reservoirs are dolomitization, karstification, and calcite cementation.

2006-07-01

269

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

International Nuclear Information System (INIS)

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

2003-01-02

270

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

British Library Electronic Table of Contents (United Kingdom)

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

2010-01-01

271

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

International Nuclear Information System (INIS)

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

272

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

Energy Technology Data Exchange (ETDEWEB)

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

1986-06-12

273

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

British Library Electronic Table of Contents (United Kingdom)

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

2010-01-01

274

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

British Library Electronic Table of Contents (United Kingdom)

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

2011-01-01

275

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

Energy Technology Data Exchange (ETDEWEB)

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

1986-02-01

276

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

Energy Technology Data Exchange (ETDEWEB)

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

1990-01-01

277

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

International Nuclear Information System (INIS)

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

278

Chemistry of strontium  

International Nuclear Information System (INIS)

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

279

Low-pH injection grout for deep repositories. Summary report from a co-operation project between NUMO (Japan), Posiva (Finland) and SKB (Sweden)  

Energy Technology Data Exchange (ETDEWEB)

The use of standard cementitious material creates pulses of pH in the magnitude of 12-13 in the leachates and release alkalis. Such a high pH is detrimental and also unnecessarily complicates the safety analysis of the repository. As no reliable pH-plume models exist, the use of products giving a pH below 11 in the leachates facilitates the safety analysis. Also, according to current understanding, the use of low-pH cement (pH = 11) will not disturb the functioning of the bentonite, although limiting the amount of low-pH cement is recommended. A result of the project is that there are both low-pH cementitious material for grouting larger fractures (= 100 {mu}m) and non-cementitious material for grouting smaller fractures (< 100 {mu}m) that will, after further optimisation work, be recommended for grouting of deep repositories. This project concentrated on the technical development of properties for the low pH grouts. Long-term safety and ...

2005-06-01

280

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

UK PubMed Central (United Kingdom)

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

281

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

UK PubMed Central (United Kingdom)

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

2010-01-01

282

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

Energy Technology Data Exchange (ETDEWEB)

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

1994-02-01

283

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

UK PubMed Central (United Kingdom)

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

2002-04-15

284

Studies on Inhibition of Intestinal Absorption of Radioactive Strontium  

UK PubMed Central (United Kingdom)

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

1964-08-08

285

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

UK PubMed Central (United Kingdom)

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

2008-11-01

286

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

UK PubMed Central (United Kingdom)

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

2011-01-01

287

Role of Calcium in Serine Transport into Tobacco Cells  

UK PubMed Central (United Kingdom)

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

1978-12-01

288

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

UK PubMed Central (United Kingdom)

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

1967-07-01

289

Regulation of Vacuolar H+-Pyrophosphatase by Free Calcium 1  

UK PubMed Central (United Kingdom)

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

1992-12-01

290

Regulation of Calcium Influx in Chara1  

UK PubMed Central (United Kingdom)

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

1992-10-01

291

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

UK PubMed Central (United Kingdom)

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

2008-03-01

292

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

Energy Technology Data Exchange (ETDEWEB)

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

1982-02-18

293

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

International Nuclear Information System (INIS)

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

1982-02-01

294

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

Energy Technology Data Exchange (ETDEWEB)

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

1980-09-16

295

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

UK PubMed Central (United Kingdom)

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

2002-12-16

296

Neurobehavioral effects of power-frequency electromagnetic fields.  

UK PubMed Central (United Kingdom)

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

1993-12-01

297

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

UK PubMed Central (United Kingdom)

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

1994-02-01

298

Imaging of calcium transients in skeletal muscle fibers.  

UK PubMed Central (United Kingdom)

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

1991-01-01

299

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

UK PubMed Central (United Kingdom)

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

300

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

Energy Technology Data Exchange (ETDEWEB)

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

1992-11-05

301

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

UK PubMed Central (United Kingdom)

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

2011-01-01

302

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

UK PubMed Central (United Kingdom)

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

2007-05-01

303

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

UK PubMed Central (United Kingdom)

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

2004-01-01

304

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

UK PubMed Central (United Kingdom)

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

1978-09-01

305

Dietary Ammonium Chloride for the Acidification of Mouse Urine  

UK PubMed Central (United Kingdom)

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

2009-03-01

306

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

UK PubMed Central (United Kingdom)

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

2008-02-01

307

Citrat og nyresten  

DEFF Research Database (Denmark)

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

1993-01-01

308

Chemical neutralization to control denting in nuclear steam generators  

International Nuclear Information System (INIS)

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

309

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

UK PubMed Central (United Kingdom)

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

2010-08-01

310

Calcium gradients and buffers in bovine chromaffin cells.  

UK PubMed Central (United Kingdom)

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

1992-05-01

311

Calcium Effects on Stomatal Movement in Commelina communis L. 1  

UK PubMed Central (United Kingdom)

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

1988-07-01

312

Cadherin Mechanics and Complexation: The Importance of Calcium Binding  

UK PubMed Central (United Kingdom)

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

2005-12-01

313

Amyloid Oligomer Neurotoxicity, Calcium Dysregulation, and Lipid Rafts  

UK PubMed Central (United Kingdom)

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

314

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

UK PubMed Central (United Kingdom)

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

2007-06-01

315

Acetylsalicylic acid as soluble tablets  

International Science & Technology Center (ISTC)

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

316

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

UK PubMed Central (United Kingdom)

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

2010-04-01

317

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

DEFF Research Database (Denmark)

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

1997-01-01

318

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

UK PubMed Central (United Kingdom)

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

2010-02-01

319

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

Science.gov (United States)

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

320

THERMALLY CONDUCTIVE CEMENTITIOUS GROUTS FOR GEOTHERMAL HEAT PUMPS. PROGRESS REPORT BY 1998  

Energy Technology Data Exchange (ETDEWEB)

Research commenced in FY 97 to determine the suitability of superplasticized cement-sand grouts for backfilling vertical boreholes used with geothermal heat pump (GHP) systems. The overall objectives were to develop, evaluate and demonstrate cementitious grouts that could reduce the required bore length and improve the performance of GHPs. This report summarizes the accomplishments in FY 98.

1998-11-01

321

Some aspects for structure selection; Algunas consideraciones para seleccionar una estructura  

Energy Technology Data Exchange (ETDEWEB)

This paper shows some considerations about the cost of wood, steel and cement support pillars in rural power distribution systems. The life span, mechanical properties, cost estimation and general durability of each type of pillar was evaluated, aiming a better selection of the desired one. 6 figs., 8 tabs., 4 refs.

1986-12-31

322

Characterization of pore structure in cement-based materials using pressurization-depressurization cycling mercury intrusion porosimetry (PDC-MIP)  

International Nuclear Information System (INIS)

Numerous mercury intrusion porosimetry (MIP) studies have been carried out to investigate the pore structure in cement-based materials. However, the standard MIP often results in an underestimation of large pores and an overestimation of small pores because of its intrinsic limitation. In this paper, an innovative MIP method is developed in order to provide a more accurate estimation of pore size distribution. The new MIP measurements are conducted following a unique mercury intrusion procedure, in which the applied pressure is increased from the minimum to the maximum by repeating pressurization-depressurization cycles instead of a continuous pressurization followed by a continuous depressurization. Accordingly, this method is called pressurization-depressurization cycling MIP (PDC-MIP). By following the PDC-MIP testing sequence, the volumes of the throat pores and the corresponding ink-bottle pores can be determined at every pore size. These values are used to ...

2010-07-01

323

Advanced composite materials made by radiation processing  

Energy Technology Data Exchange (ETDEWEB)

An industrial EB processing line is started to produce cement-bound /CB/ chipboard with radiation cured acrylic coating. The basic features of this line are presented here. The main technological parameters of coating such as: effect of oligomer- and monomer reactivity, monomer functionality, dose-rate and inerting atmosphere on the progress of curing have been discussed. The EB processed CB board is an advanced composite material for the modern lightweight architecture.

1988-01-01

324

Yttrium Calcium Oxyborate for high average power frequency doubling and OPCPA  

Science.gov (United States)

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

2006-06-20

325

The early days of parathyroid surgery.  

Science.gov (United States)

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

2011-03-01

326

Stabilisation of #alpha#-Sialons using multiple additives  

International Nuclear Information System (INIS)

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

1998-09-28

327

Physical aspects of FGD by-products  

Energy Technology Data Exchange (ETDEWEB)

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

1992-01-01

328

New coumarin-based sensor molecule for magnesium and calcium ions  

British Library Electronic Table of Contents (United Kingdom)

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

2009-01-01

329

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

Energy Technology Data Exchange (ETDEWEB)

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

1985-03-05

330

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

International Nuclear Information System (INIS)

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

331

Heat storage composition  

Energy Technology Data Exchange (ETDEWEB)

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

1987-05-05

332

Exact solution to NO/sub 2/ absorption  

Energy Technology Data Exchange (ETDEWEB)

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

1984-04-01

333

Regulation of the phosphoinositide pathway in cultured Sertoli cells from immature rats: effects of follicle-stimulating hormone and fluoride  

International Nuclear Information System (INIS)

Many hormones elicit effects on target cells by stimulating the enzyme phospholipase-C, which catalyzes the hydrolysis of phosphoinositides to the intracellular second messengers diacylglycerol and inositol phosphates. The present study examined the roles of FSH and guanine nucleotide-binding proteins (G-proteins) in regulating the hydrolysis of phosphoinositides in Sertoli cells. Sertoli cell cultures prepared from 16- to 18-day-old rats were incubated for 24 h with myo-[2-3H] inositol to label endogenous phospholipids. Treatment of cells from 0.5-20 min with preparations of ovine FSH ranging in potency from 1-60 times that of NIH FSH S1 did not affect accumulation of inositol phosphates. Levels of total [3H]inositol phosphates [[3H]inositol mono-, di-, and triphosphates (IP, IP2, and IP3)] in FSH-treated cultures was 75-120% the levels in control cultures over the various time intervals studied. Addition of testosterone ...

334

Radiolabeling of a wound-inducible pyridoxal phosphate utilizing protein from tomato: evidence for its identification as ACC synthase  

International Nuclear Information System (INIS)

Aminocyclopropane 1-carboxylic acid (ACC) synthase, a pyridoxal phosphate utilizing enzyme, catalyzes the conversion of S-adenosylmethionine to ACC, the rate limiting step in the biosynthesis of the plant hormone, ethylene. Ethylene, besides being involved in normal plant growth processes, is also produced in response to stress, e.g. wounding, pathogen infection, etc. The authors report the partial purification (400 fold) of ACC synthase from wounded pink tomato pericarp by classical techniques including ammonium sulfate precipitation, ion exchange and phenyl sepharose chromatography. Further purification results in a decrease in specific activity apparently due to the instability of the enzyme and the low levels present in plant tissue. Radiolabeling of a pyridoxal phosphate-utilizing protein in the ACC synthase enriched fraction was achieved. Evidence that this radiolabeled protein is ACC synthase will be presented. Amino acid sequence ...

1986-06-08

335

Mechanism of biosorption of Heavy metals by mucor rouxii  

Energy Technology Data Exchange (ETDEWEB)

Fungi such as Aspergillus niger and Mucor rouxii are capable of removing heavy metals from aqueous solutions. The role various functional groups play in the cell wall of M. rouxii in metal biosorption of lead, cadmium, nickel and zinc was investigated in this paper. The biomass was chemically treated to modify the functional carboxyl, amino and phosphate groups. These modifications were examined by means of infrared spectroscopy. It was found that an esterification of the carboxyl groups and phosphate and a methylation of the amine groups significantly decreased the biosorption of the heavy metals studied. Thus, the carboxylate, amine and phosphate groups were recognized as important in the biosorption of metal ions by M. rouxii biomass. The role the lipids fraction play was not significant. The study showed that Na, K, Ca and Mg ions were released from the biomass after biosorption of Pb,Cd,Ni and Zn, indicating that ion ...

2008-08-15

336

Identification of the binding domain for NADP"+ of human glucose-6-phosphate dehydrogenase by sequence analysis of mutants  

International Nuclear Information System (INIS)

Human erythrocyte glucose-6-phosphate is normally quite stable in the presence of 10 #mu#M NADP"+. Certain glucose-6-phosphate dehydrogenase variants lose virtually all their activity at this concentration of NADP"+ but are reactivated by 200 #mu#M NADP"+. Such variants presumably have a defect in their NADP"+-binding site. The authors analyzed the sequence of cDNA or genomic DNA from seven unrelated patients with hemolytic anemia due to the inheritance of variants that are reactivated by NADP"+. Six patients had substitutions of one of three adjacent amino acids, and the seventh patient had another amino acid substitution 23 residues downstream. These amino acids are highly conserved, all being present in rat and all but one being found also in Drosophila. The anomalous electrophoretic behavior of some of the variants can be explained by their loss of ability to bind NADP"+. The conclude that the region in which these mutations occur defines ...

337

Development and application of microbial selective plugging processes  

Energy Technology Data Exchange (ETDEWEB)

Phillips Petroleum Company recently completed a microbial selective plugging (MSP) pilot at the North Burbank Unit (NBU), Shidler, Oklahoma. Nutrients were selected for the pilot that could stimulate indigenous microflora in the reservoir brine to grow and produce exopolymer. It was found that soluble corn starch polymers (e.g., maltodextrins) stimulated the indigenous bacteria to produce exopolymer, whereas simple sugars (e.g., glucose and sucrose), as well as complex media (e.g., molasses and Nutrient Broth), did not. Injection of maltodextrin into rock cores in the presence of indigenous NBU bacteria resulted in stable permeability reductions (> 90%) across the entire length, while injection of glucose resulted only in face plugging. In addition, it was found that organic phosphate esters (OPE) served as a preferable source of phosphorus for the indigenous bacteria, since orthophosphates and condensed phosphates precipitated in NBU brine ...

1995-12-31

338

Status and progress in sludge washing: A pivotal pretreatment method  

Energy Technology Data Exchange (ETDEWEB)

Separation of the bulk soluble chemical salts from the insoluble metal hydroxides and radionuclides is central to the strategy of disposing Hanford tank waste. Sludge washing and caustic leaching have been selected as the primary methods for processing the 230 million L (61,000,000 gal) of Hanford tank waste. These processes are very similar to those selected for processing waste at the West Valley Site in New York and the Savannah River Site in South Carolina. The purpose of sludge washing is to dissolve and remove the soluble salts in the waste. Leaching of the insoluble solids with caustic will be used to dissolve aluminum hydroxide and chromium hydroxide, and convert insoluble bismuth phosphate to soluble phosphate. The waste will be separated into a high-level solids fraction and a liquid fraction that can be disposed of as low-level waste after cesium removal. The washing and leaching operations involve batchwise mixing, settling, and ...

1995-01-01

339

Precise lithium isotopic analysis by thermal ionization mass spectrometry using lithium phosphate as an ion source material  

International Nuclear Information System (INIS)

A high-precision Li isotope analysis was developed for determining the Li"+ ion emitted from lithium phosphate as an ion source material by a Re double-filament ionization method in the thermal ionization mass spectrometry. In this method, Li isotopic fractionation is distinctly less sensitive to the filament temperature than those in the previous methods, and stable and high ion beam intensity of more than 8 x 10"-"1"1 A for "7Li is obtained. These advantages in determining the "7Li/"6Li ratio result in the analytical reproducibility of 0.26 per mille (1#sigma#). Furthermore, the sample preparation is simple and the low temperature (850degC) required by this method ensures the analysis of the isotopic composition of small amounts of Li with less influence of Li contamination to the sample, compared with the previous methods. (author).

340

Kinetics of inhibition of green crab (Scylla serrata) alkaline phosphatase by sodium (2,2'-bipyridine) oxodiperoxovanadate.  

Science.gov (United States)

Green crab (Scylla serrata) alkaline phosphatase (EC 3.1.3.1) is a metalloenzyme, which catalyzes the nonspecific hydrolysis of phosphate monoesters. The kinetics of inhibition of the enzyme by sodium (2, 2'-bipyridine) oxodiperoxovanadate, pV(bipy), has been studied. The time course of the hydrolysis of p-nitrophenyl-phosphate catalyzed by the enzyme in the presence of different pV(bipy) concentrations showed that at each pV(bipy) concentration, the rate decreased with increasing time until a straight line was approached, the straight line slopes are the same for all concentrations. The results suggest that the inhibition of the enzyme by pV(bipy) is a slow, reversible reaction with fractional remaining activity. The microscopic rate constants are determined for the reaction of inhibitor with the enzyme. PMID:10691182

1999-10-01

341

High-temperature investigations of the rare earth NZP phosphates R {sub 1/3}Zr{sub 2}(PO{sub 4}){sub 3} (R = La, Nd, Eu, Lu) by drop calorimetry  

Energy Technology Data Exchange (ETDEWEB)

The high-temperature enthalpy increments of the phosphates La{sub 1/3}Zr{sub 2}(PO{sub 4}){sub 3}, Nd{sub 1/3}Zr{sub 2}(PO{sub 4}){sub 3}, Eu{sub 1/3}Zr{sub 2}(PO{sub 4}){sub 3} and Lu{sub 1/3}Zr{sub 2}(PO{sub 4}){sub 3} have been measured by high-temperature drop calorimetry in the temperature range 484.5-1090.7 K. From these results the heat capacity of the studied compounds has been derived.

2007-07-31

342

Fluoride phosphate Li{sub 2}CoPO{sub 4}F as a high-voltage cathode in Li-ion batteries  

Energy Technology Data Exchange (ETDEWEB)

As a new high-voltage cathode candidate for post 4V cathodes, ordered-olivine LiCoPO{sub 4} and fluoride phosphate, Li{sub 2}CoPO{sub 4}F were synthesized by solid-state reaction. Their structures were identified by neutron diffraction. The 5V discharge profiles were demonstrated using coin-type cells. Two important issues for commercial use, metal dissolution and oxygen release at elevated temperatures, were also tested with an atomic absorption spectrophotometer and differential scanning calorimeter, respectively. (author)

2005-08-26

343

Distinguishing two groups of flavin reductases by analyzing the protonation state of an active site carboxylic acid  

British Library Electronic Table of Contents (United Kingdom)

Abstract Flavin-containing reductases are involved in a wide variety of physiological reactions such as photosynthesis, nitric oxide synthesis, and detoxification of foreign compounds, including therapeutic drugs. Ferredoxin-NADP(H)-reductase (FNR) is the prototypical enzyme of this family. The fold of this protein is highly conserved and occurs as one domain of several multidomain enzymes such as the members of the diflavin reductase family. The enzymes of this family have emerged as fusion of a FNR and a flavodoxin. Although the active sites of these enzymes are very similar, different enzymes function in opposite directions, that is, some reduce oxidized nicotinamide adenine dinucleotide phosphate (NADP+) and some oxidize reduced nicotinamide adenine dinucleotide phosphate (NADPH). In t...

2011-01-01

344

Comparison of sodium zirconium phosphate and Synroc matrices for immobilization of high-level waste  

Energy Technology Data Exchange (ETDEWEB)

The aims of the present work were to investigate possible compatibility between sodium zirconium phosphate (NZP) and Synroc titanate phases, to prepare NZP-based waste forms by hot-pressing rather than sintering, and to investigate the incorporation in NZP of (a) Cs/Sr as simulated heat-generating nuclides; (b) simulated actinides; and (c) simulated Purex waste. The NZP samples were prepared by methods similar to those used for Synroc. The precursor NZP phase was formed from tetrabutyl zirconate Zr(OC{sub 4}H{sub 9}){sub 4}, sodium nitrate, and 85% orthophosphoric acid. Simulated waste nitrate solutions were then mixed with the liquid precursor. After stir drying of the precursor, calcination was carried out at 700{degree}C to remove nitrates and organics.

1996-12-31

345

A novel structural mechanism for redox regulation of uridine phosphorylase 2 activity  

British Library Electronic Table of Contents (United Kingdom)

Uridine phosphorylase (UPP) catalyzes the reversible conversion of uridine to uracil and ribose-1-phosphate and plays an important pharmacological role in activating fluoropyrimidine nucleoside chemotherapeutic agents such as 5-fluorouracil and capecitabine. Most vertebrate animals, including humans, possess two homologs of this enzyme (UPP1 & UPP2), of which UPP1 has been more thoroughly studied and is better characterized. Here, we report two crystallographic structures of human UPP2 (hUPP2) in distinctly active and inactive conformations. These structures reveal that a conditional intramolecular disulfide bridge can form within the protein that dislocates a critical phosphate-coordinating arginine residue (R100) away from the active site, disabling the enzyme. In vitro activity measurem...

2011-01-01

346

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

Science.gov (United States)

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

2005-07-05

347

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

Energy Technology Data Exchange (ETDEWEB)

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

1981-10-01

348

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

Energy Technology Data Exchange (ETDEWEB)

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

1985-01-01

349

Upward migration of underground injected wastes through hydrologic conduits around the wellbore  

Energy Technology Data Exchange (ETDEWEB)

Underground injection, compared to other waste disposal methods, is considered to have the advantages of isolating wastes in a confined brine aquifer well below the horizon of human activity and underground sources of drinking water (USDWs). While most of injected wastes move laterally in the injection zone, posing a long-term concern to the human health and environment, a small amount can migrate upward to the upper aquifers, causing a greater threat to the quality of USDWs. Both the dual porosity and the single porosity models were used to investigate the migration of injected wastes through these hydrologic conduits. The results indicate that regional upward migration through an extensive confining formation is a slow process. Nevertheless, injected wastes can move upward rapidly through microannuli and channels in the cement sheath and spread over a distance in the upper aquifer. The wastes can also migrate fast through fractures in the disturbed zone. The ...

1988-01-01

350

Radiological aspects of the usability of red mud as building material additive  

International Nuclear Information System (INIS)

Several researchers have examined and achieved favourable results in connection with the building industry's use of red mud extracted in large quantities from the processing of bauxite. These days more and more precedence is being given to limiting the radiological dose to the population. In this study carried out in Hungary, the use of red mud, bauxite, and clay additives recommended for the production of special cements, were examined from a radiological aspect. "2"2"6Ra and "2"3"2Th activity concentrations measured in Hungarian bauxite, red mud and clay samples were significantly similar with the levels for such raw materials mentioned in international literature. Taking radiation protection aspects into consideration, none of these products can be directly used for building construction. Taking Hungarian and international values into consideration, a small amount of red mud, not exceeding 15% could be used for brick production, for example as a colouring ...

2008-02-11

351

Radiochemical separation of no-carrier-added {sup 177}Lu as produced via the {sup 176}Ybn,{gamma}{sup 177}Yb{yields}{sup 177}Lu process  

Energy Technology Data Exchange (ETDEWEB)

The {sup 176}Ybn,{gamma}{sup 177}Yb-{beta}{sup -}{yields}{sup 177}Lu process was investigated to provide no-carrier-added (nca) {sup 177}Lu. The radiochemical separation of the {sup 177}Lu from the macro-amounts of the ytterbium target based on the cementation process, i.e. the selective extraction of Yb by Na(Hg) amalgam from Cl{sup -}/CH{sub 3}COO{sup -} electrolytes, followed by a final cation exchange purification. The cementation separation process provides a decontamination factor of Yb(III) of 10{sup 4}, the cation exchange purification adding a decontamination factor of >10{sup 2}. The nca {sup 177}Lu is available in radiochemically pure form despite the chemical similarity of the lanthanides with 75{+-}5% overall separation yield within 4-5 h. It can be used to synthesise nca {sup 177}Lu labelled radiotherapeuticals.

2000-09-15

352

Oxidation resistance of C/C composites coated by SiC in premixed methane-air combustion; SiC hifuku sareta C/C konpojietto no metan-kuki yokongo nenshojochu ni okeru taisanka tokusei  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the effects of SiC coating on the oxidation resistance of C/C composites in combusting fields, which are expected to be applied to high temperature structural materials at over 1770K. The coating methods employed were CVD and pack cementation. The time changes in weight loss of the specimens were measured at temperatures of 1770K and 1900K under the equivalence ratio of 0.9 generated by methane-air combustion, and the surface of the specimens before and after the experiment was observed by SEM. Although the weight loss of the specimens coated by the CVD method was minimal, the coating layer was easily peeled off from the substrate. On the other hand, the layer of the specimens coated by the pack cementation method was stable and adhered to the substrate, but the substrate was degraded because of penetration of oxygen through the pores in the layer. To cover the pores, the specimens were additionally coated with glass ...

1997-11-01

353

Mixed waste solidification testing on polymer and cement-based waste forms in support of Hanford`s WRAP 2A facility  

Energy Technology Data Exchange (ETDEWEB)

A testing program has been conducted by the Westinghouse Hanford Company to confirm the baseline waste form selection for use in Waste Receiving and Processing (WRAP) Module 2A. WRAP Module 2A will provide treatment required to properly dispose of containerized contact-handled, mixed low-level waste at the US Department of Energy Hanford Site in south-central Washington State. Solidification/stabilization has been chosen as the appropriate treatment for this waste. This work is intended to test cement-based, thermosetting polymer, and thermoplastic polymer solidification media to substantiate the technology approach for WRAP Module 2A. Screening tests were performed using the major chemical constituent of each waste type to measure the gross compatibility with the immobilization media and to determine formulations for more detailed testing. Surrogate materials representing each of the eight waste types were prepared in the laboratory. These surrogates were then ...

1993-10-01

354

Experience on resin pyrolysis  

International Nuclear Information System (INIS)

The Swedish State Power Board has together with Nukem, Hanau, West-Germany carried out pyrolysis o powder resins in a pilot plant with a capacity of about 30 kg/hr. The pyrolysis reactor with its afterburner and offgas scrubber system has been operated under steady state condition. About 2200 kg resins have been pyrolysed under November-December 1983 and the decontamination factor for Cs has been measured. Solidification of the residues from the pyrolysis reactor and scrubber water solutions has been carried out and various recipes with cement have been tested. The pyrolysis process has high decontamination factors and no offgas problems as the operating temperature of the reactor is Low. The residues from the reactor are chemically dead and can not cause swelling problems. Compared with a normal cementation process the final waste volume will be reduced with a factor of 4 if also the scrubber water after neutralization is solidified. The ...

355

EDF waste packages transport and compliance with regulations: prediction of retention of radionuclides by cementitious materials  

International Nuclear Information System (INIS)

Different concrete waste packages have been designed by Electricite de France (EDF) for the long-term storage of radioactive Low Level Waste (LLW). Their main function is to confine radionuclides from the biosphere for three hundred years in a near-surface disposal. According to the transport regulations, a Type-B package is needed for some waste like water filters. The water filters from EDF nuclear power plants are encapsulated in mortar and placed in a concrete container. Transport regulations for these containers have required the development of a methodology for safety assessment. The reference scenario of container degradation during transport considers a 9 m drop and a 800"oC fire for 30 min. First, the different chemical and physical processes involved in the containment of radionuclides are analysed. In particular, the radionuclide transport mechanisms in cement-based materials have been reviewed. Secondly, the effects of a container drop on the mortar and ...

356

Diverter bop system and method for a bottom supported offshore drilling rig  

Energy Technology Data Exchange (ETDEWEB)

A system and method for installing a fluid flow controller and telescoping spools beneath an offshore bottom supported drilling rig rotary table is disclosed. Upper and lower telescoping spools are provided for initially connecting a Diverter/BOP convertible fluid flow controller between structural casing in the well and a permanent housing beneath the drilling rig rotary table. Clamp means are provided for clamping the rig vent line to an opening in the housing wall of the fluid flow controller during drilling of the borehole through the structural casing in preparation for setting and cementing the conductor casing. In that mode, the system is adapted as a diverter system. After the well is drilled for the conductor casing and the conductor casing is cemented and cut off at its top, a mandrel is fitted at the top of the conductor casing to which the lower end of the lower spool may be connected. The system may be used in this configuration as ...

1985-06-25

357

Column leaching test to evaluate the use of alkaline industrial wastes to neutralize acid mine tailings  

Energy Technology Data Exchange (ETDEWEB)

Acid mine drainage is a serious environmental problem caused by the oxidation of sulfide minerals that releases highly acidic, sulfate, and metals-rich drainage. In this study, alkaline industrial wastes were mixed with acid mine tailings in order to obtain neutral conditions. A series of column leaching tests were performed to evaluate the behavior of reactive mine tailings amended with alkaline-additions under dynamic conditions. Column tests were conducted of oxidized mine tailings combined with cement kiln dust, red mud bauxite, and mixtures of cement kiln dust with red mud bauxite. The pH results show the addition of 10% of alkaline materials permits the maintenance of near neutral conditions. In the presence of 10% alkaline material, the concentration of toxic metals such as Al, Cu, Fe, Zn are significantly reduced as well as the number of viable cells (Thiobacillus ferrooxidans) compared to control samples.

2005-08-01

358

Chromized/siliconized diffusion coatings for iron-base alloy by pack cementation  

Energy Technology Data Exchange (ETDEWEB)

This paper reports that the co-deposition of chromium and silicon into a 2.25Cr-1.0Mo-0.15C steel, alloy 800, and type 304 stainless steel has been achieved using the pack cementation process. The ferritic coating produced on the 2.25 Cr-1.0Mo steel was approximately 225 {mu}m (9 mils) thick, whereas the inward diffusion of chromium and silicon produced a two-phase structure of ferrite and austenite for type 304. Chromium and silicon were incorporated into the austenitic solid solution upon diffusion into alloy 800. All coatings had approximately 25 to 35 wt% Cr and 2 to 3% Si at the surface. Cyclic oxidation testing in air of the coated 2.25Cr-1.0Mo steel (T = 700{degrees} C) and type 304 (T = 1035{degrees} C) showed a dramatic decrease in the oxidation kinetics compared to the original uncoated alloys. The cyclic oxidation of alloy 800 was also improved.

1991-09-01

359

Waste treatment by dialysis. (Latest citations from Pollution abstracts). Published Search  

Energy Technology Data Exchange (ETDEWEB)

The bibliography contains citations concerning the use of dialysis in the treatment of wastewaters. Techniques for the removal of metals, ammonia, waste acids, nitrates, and phosphates are described. Special attention is given to the desalination of liquid wastes. Applications of this technology to the treatment of effluent from the agrochemical, petrochemical, tanning, and electroplating industries are discussed. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

1996-02-01

360

Three Homologous Genes Encoding sn-Glycerol-3-Phosphate Acyltransferase 4 Exhibit Different Expression Patterns and Functional Divergence in Brassica napus1[C][W][OA]  

UK PubMed Central (United Kingdom)

Brassica napus is an allotetraploid (AACC) formed from the fusion of two diploid progenitors, Brassica rapa (AA) and Brassica oleracea...Full Text Available

2011-02-01

361

The direct interaction between ASH2, a Drosophila trithorax group protein, and SKTL, a nuclear phosphatidylinositol 4-phosphate 5-kinase, implies a role for phosphatidylinositol 4,5-bisphosphate in maintaining transcriptionally active chromatin.  

UK PubMed Central (United Kingdom)

The products of trithorax group (trxG) genes maintain active transcription of many important developmental regulatory genes, including homeotic genes. Several trxG proteins have been shown to act in...Full Text Available

2004-07-01

362

Sustainable phosphorous fertilisation of potatoes (Potato CHIPS)  

Environmental Research Database

DescriptionThis project has two independent aims: (1) to investigate the use of struvite as an alternative to chemical P fertilisers and (2) to develop an oligonucleotide microarray to monitor the P status of the potato crop. The UK horticultural and agricultural industries rely on large inputs of phosphate (P) fertilisers to maintain crop yields and quality. However, the use of non-renewable, chemical P fertilisers is unsustainable, and the alternatives to chemical P-fertilisers must be identified as an [continued...

2008-01-31

363

Superoxide production by NAD(P)H oxidase and mitochondria is increased in genetically obese and hyperglycemic rat heart and aorta before the development of cardiac dysfunction. The role of glucose-6-phosphate dehydrogenase-derived NADPH  

UK PubMed Central (United Kingdom)

Increased oxidative stress is a known cause of cardiac dysfunction in animals and patients with diabetes, but the sources of reactive oxygen species [e.g., superoxide anion (O2)]...Full Text Available

2009-07-01

364

Safe venting of ``red oil`` runaway reactions  

Energy Technology Data Exchange (ETDEWEB)

Calorimetry testing of Tri-n-butyl phosphate (TBP) saturated with strong nitric acid was performed to determine the relationship between vent size and pressure buildup in the event of a runaway reaction. These experiments show that runaway can occur in an open system, but that even when runaway is induced in the TBP/HN0{sub 3} system, dangerous pressure buildup will be prevented with practical vent size.

1994-12-21

365

Phosphorus-containing catalyst and catalytic cracking process utilizing the same  

Energy Technology Data Exchange (ETDEWEB)

A phosphorus-containing low alkali metal content zeolitic catalyst made from a clay starting material is provided. The catalyst is obtained by contacting a partially cation exchanged calcined zeolite-containing catalyst with a dihydrogen phosphate anion or a dihydrogen phosphite anion. A hydrocarbon catalytic cracking process utilizing the phosphorus-containing catalyst is also provided.

1985-02-12

366

Phosphorus-containing catalyst and catalytic cracking process utilizing the same  

Energy Technology Data Exchange (ETDEWEB)

A phosphorus-containing low alkali metal content zeolitic catalyst made from a clay starting material is provided. The catalyst is obtained by contacting a partially cation exchanged calcined zeolite-containing catalyst with an anion such as a dihydrogen phosphate anion or a dihydrogen phosphite anion and additionally with an ammonium salt other than a salt of an inorganic acid of phosphorus. A hydrocarbon catalytic cracking process utilizing the phosphorus-containing catalyst is also provided.

1985-03-12

367

Nucleotide sequence and genetic analysis of a 13.1-kilobase-pair Pseudomonas denitrificans DNA fragment containing five cob genes and identification of structural genes encoding Cob(I)alamin adenosyltransferase, cobyric acid synthase, and bifunctional cobinamide kinase-cobinamide phosphate guanylyltransferase.  

UK PubMed Central (United Kingdom)

A 13.1-kb DNA fragment carrying Pseudomonas denitrificans cob genes has been sequenced. The nucleotide sequence and genetic analysis revealed that this fragment contained five different cob genes named...Full Text Available

1991-10-01

368

Method of purifying uranium tetrafluoride hydrate and preparing uranium (VI) peroxide hydrate using a fluoride complexing agent  

International Nuclear Information System (INIS)

The annual production of phosphate rock, on the order of about 30-40 million tons yearly, represents several million pounds of uranium. The present invention provides a process of purifying uranium tetrafluoride hydrate to produce a uranium (VI) peroxide product meeting 'yellow cake' standards using a double precipitation procedure. A fluoride complexing agent is used in the precipitation.

1978-06-27

369

Hydrothermal synthesis of tobermorite/hydroxyapatite composites  

British Library Electronic Table of Contents (United Kingdom)

A tobermorite/hydroxyapatite composite was prepared by hydrothermal treatment using diatomaceous earth, ?-tricalcium phosphate and slaked lime starting materials. The XRD patterns of the composite confirmed that tobermorite and hydroxyapatite were formed after the hydrothermal process. The bending strength of the composite reached a level higher than 9?MPa after the hydrothermal process. The development of the bending strength was due to the formation of tobermorite and hydroxyapatite during the hydrothermal process. The composite had a high specific surface area due to these newly formed crystals.

2008-01-01

370

Evolution of a bifunctional enzyme: 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase.  

UK PubMed Central (United Kingdom)

The bifunctional rat liver enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (ATP:D-fructose-6-phosphate 2-phosphotransferase/D-fructose-2,6-bisphosphate 2-phosphohydrolase, EC 2.7.1.105/EC...Full Text Available

1989-12-01

371

Essential Role for Cellular Phosphoglucomutase in Virulence of Type 3 Streptococcus pneumoniae  

UK PubMed Central (United Kingdom)

Synthesis of the Streptococcus pneumoniae type 3 capsule requires the pathway glucose-6-phosphate (Glc-6-P) → Glc-1-P → UDP-Glc → UDP-glucuronic acid (UDP-GlcUA)...Full Text Available

2001-04-01

372

Elucidating novel pathways and regulation of nitrogen assimilation in alpha proteobacteria exemplified by the soil organism Paracoccus denitrificans  

Environmental Research Database

DescriptionThe importance of inorganic nitrate for the nutrition and growth of marine and freshwater autotrophic phytoplankton has long been recognised, in particularly because of the 'blooms' formed in nitrate and phosphate polluted water and their possible roles as carbon dioxide sinks. By contrast, the utilisation of nitrate by heterotrophic bacteria has historically received less attention. Up until now, the primary role of heterotrophic bacteria has classically been considered to be the decomposition [continued...

2010-01-31

373

Electrophilic addition of astatine  

International Nuclear Information System (INIS)

It has been shown for the first time that astatine is capable of undergoing addition reactions to unsaturated hydrocarbons. A new compound of astatine, viz., ethylene astatohydrin, has been obtained, and its retention numbers of squalane, Apiezon, and tricresyl phosphate have been found. The influence of various factors on the formation of ethylene astatohydrin has been studied. It has been concluded on the basis of the results obtained that the univalent cations of astatine in an acidic medium is protonated hypoastatous acid.

374

EFFECTS OF PH AND PHOSPHATE ON METAL DISTRIBUTION WITH EMPHASIS ON AS SPECIATION AND MOBILIZATION IN SOILS FROM A LEAD SMELTING SITE  

Science.gov (United States)

Arsenic in soils from the Asarco Lead Smelter in East Helena, Montana was characterized by X-ray absorption spectroscopy (XAS). As oxidation state and geochemical speciation were analyzed as a function of depth (two sampling sites) and surface distribution. These results were c...

375

Adenine and guanine recognition of stop codon is mediated by different N domain conformations of translation termination factor eRF1  

UK PubMed Central (United Kingdom)

Positioning of release factor eRF1 toward adenines and the ribose-phosphate backbone of the UAAA stop signal in the ribosomal decoding site was studied using messenger RNA (mRNA) analogs containing...Full Text Available

2011-09-01

376

Solidification of problem wastes: Annual progress report, October 1985-September 1986  

Energy Technology Data Exchange (ETDEWEB)

This report describes initial work on the development of solidification systems for sodium nitrate waste and compacted waste. Sodium nitrate waste has been solidified in three types of materials: polyethylene, polyester-styrene (PES), and latex cement. Evaluations of the properties of the waste form, such as the ANS 16.1 leaching test, water immersion test and compressive strength measurements were performed on the waste forms containing various amounts of sodium nitrate. 9 refs., 9 figs., 7 tabs.

1987-02-01

377

Radiological performance assessment for the E-Area Vaults Disposal Facility  

Energy Technology Data Exchange (ETDEWEB)

This report is the first revision to ``Radiological Performance Assessment for the E-Area Vaults Disposal Facility, Revision 0'', which was issued in April 1994 and received conditional DOE approval in September 1994. The title of this report has been changed to conform to the current name of the facility. The revision incorporates improved groundwater modeling methodology, which includes a large data base of site specific geotechnical data, and special Analyses on disposal of cement-based wasteforms and naval wastes, issued after publication of Revision 0.

2000-04-11

378

Proceedings of the 8. CANMET/ACI international conference on superplasticizers and other chemical admixtures in concrete : supplementary papers[ACI SP-239  

Energy Technology Data Exchange (ETDEWEB)

This book provided a set of supplementary papers provided to delegates at the eighth international CANMET/ACI conference on superplasticizers and chemical admixtures in concrete. Recent research on chemical admixtures and superplasticizers was presented along with new approaches to the practical application of concrete admixtures. The presentations highlighted technological advances in the development of superplasticizers and new approaches to the manufacture and implementation of aggregates. Issues regarding the application of plasticizers with various aggregates were addressed, and interactions between cements and superplasticizers were evaluated. Four of the supplementary papers have been catalogued separately for inclusion in this database. refs., tabs., figs.

2006-07-01

379

Problems and approach to geological disposal of radioactive waste  

International Nuclear Information System (INIS)

This feature articles described a concept and technical problems of geological disposal of high-level radioactive waste in the civil engineering. It consists of six papers such as the present statues and subjects of geological disposal by KITAYAMA Kazumi, the diastrophism, igneous activity, and upheaval and erosion by YAMAZAKI Haruo, the groundwater flow and evaluation of nuclear transfer by IJIRI Yuji, evaluation of alteration of cement materials in the ultra-long period by HAGA Kazuko, The Mizunami Underground Research Laboratory in course of construction by SAKAMAKI Masanori, and interview of the ninetieth president of JSCE (Japan Society of Civil Engineers), he places his hope on JSCE and civil engineers by KISHI Kiyoshi. (S.Y.)

2006-11-01

380

Problematic of atmospheric pollution in Lebanon: the better stake is apprehended, the best acts are taken  

International Nuclear Information System (INIS)

The article is an overview on atmospheric pollution in Lebanon. It presents an analysis of sources of pollution in the country and their impacts on local and global environment and describes their control. Air pollution is mainly due to the industrial, electrical and transportation sectors. Pollutants from fuel combustion are analyzed. It is estimated that in 2010, CO_2 emissions will reach 5987250 tons, SO_2 emissions is estimated to be 182950 tons, Nox to 105180 and dusts to 4965 tons. CFC consumption and measures of control according to Montreal protocol are described. Consumption of primary energy, consumption of petroleum products, quantity of petroleum in refineries and production of cement in Lebanon are also presented in tables

2000-02-01

381

Multi-scale modeling of fiber and fabric reinforced cement based composites  

Science.gov (United States)

With an increased use of fiber reinforced concrete in structural applications, proper characterization techniques and development of design guides are needed. This dissertation presents a multi-scale modeling approach for fiber and fabric reinforced cement-based composites. A micromechanics-based model of the yarn pullout mechanism due to the failure of the interfacial zone is presented. The effect of mechanical anchorage of transverse yarns is simulated using nonlinear spring elements. The yarn pullout mechanism was used in a meso-scale modeling approach to simulate the yarn bridging force in the crack evolution process. The tensile stress-strain response of a tension specimen that experiences distributed cracking can be simulated using a generalized finite difference approach. The stiffness degradation, tension stiffening, crack spacing evolution, and crack width characteristics of cement composites can be derived using matrix, interface and ...

2008-01-01

382

In situ monitoring of grouted electrolytes  

Energy Technology Data Exchange (ETDEWEB)

Cement-based composites are widely used in applications which demand long-term service life. One important example is in immobilization matrices for low-level radioactive and other hazardous wastes, which demands long-term retention and durability. The authors describe conductivity measurements of grouts flooded with water and in contact with a sink that consists of pure water. The conductivity measurements were designed and carried out in parallel with present quality verification methods and standard leach tests of the nuclear waste management industry. For the first time, the authors show that the method of replacing intrusive chemical analysis with conductivity measurements of the leaching samples yields equivalent results.

1996-04-01

383

Geothermal well cost sensitivity analysis: current status  

Energy Technology Data Exchange (ETDEWEB)

The geothermal well-cost model developed by Sandia National Laboratories is being used to analyze the sensitivity of well costs to improvements in geothermal drilling technology. Three interim results from this modeling effort are discussed. The sensitivity of well costs to bit parameters, rig parameters, and material costs; an analysis of the cost reduction potential of an advanced bit; and a consideration of breakeven costs for new cementing technology. All three results illustrate that the well-cost savings arising from any new technology will be highly site-dependent but that in specific wells the advances considered can result in significant cost reductions.

1980-01-01

384

Construction: Masonry. Secondary Schools. Curriculum Guide.  

Science.gov (United States)

This construction curriculum guide on masonry for secondary students is one of six developed for inservice teachers at Marianas High School in Saipan. The guide provides the rationale, description, goals, and objectives of the program; the program of studies and performance objectives by levels; samples of lesson plans for effective delivery of instruction; and a listing of references. Concepts covered include orientation to masonry construction, safety, tools and equipment, cement, concrete, concrete block masonry, concrete forms, and concrete reinforcement. Appended materials include transparency copies, tests and answer keys, information sheets, and student activities. (CT)

1980-08-01

385

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

Energy Technology Data Exchange (ETDEWEB)

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

1994-03-15

386

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

Energy Technology Data Exchange (ETDEWEB)

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

1999-11-01

387

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

Energy Technology Data Exchange (ETDEWEB)

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

1999-01-01

388

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

Energy Technology Data Exchange (ETDEWEB)

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

1986-03-05

389

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

International Nuclear Information System (INIS)

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

1986-04-13

390

Crystallization fouling of calcium sulfate dihydrate on heat-transfer surfaces  

Energy Technology Data Exchange (ETDEWEB)

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

1996-02-01

391

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

Energy Technology Data Exchange (ETDEWEB)

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

1997-02-03

392

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

Energy Technology Data Exchange (ETDEWEB)

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

1988-02-01

393

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

Energy Technology Data Exchange (ETDEWEB)

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

1983-01-01

394

Activation of fat cell adenylate cyclase by protein kinase C  

Energy Technology Data Exchange (ETDEWEB)

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

1986-05-01

395

Hydrogeochemical properties of caulk dykes : impact on underground stowing and surface storage; Proprietes hydrogeochimiques des remblais en pate : impact sur le remblayage souterrain et l'entreposage en surface  

Energy Technology Data Exchange (ETDEWEB)

Samples from three mine tailings, the Hemlo Mine (located in Northern Ontario), the Louvicourt Mine, and the Laronde Mine (both located in Northwestern Quebec) and four different types of hydraulic binder in three different proportions (3, 4.5, 6 per cent of total dry weight of tailings) were used to prepare 33 recipes for cement caulk. The sulphur content of the three tailings is, respectively, 5 per cent, 16 per cent, and 32 per cent. Three of the four hydraulic binders are in fact a mix of two cement types: binder based on Portland cement (CP), binder based on fly ash (FA), and binder based on dross (CL). The fourth binder is based mainly on dross. The coupons of caulk dykes were flushed at 14, 28, 56, and 91 days in a humid chamber. At each of these steps, the samples were characterized for chemical, geochemical, physical, microstructural, and mechanical attributes to better understand the hydrogeochemical properties of ...

2000-07-01

396

Uranium and thorium based phosphate matrix: synthesis, characterizations and lixiviation; Matrices a base de phosphate d'uranium et de thorium: syntheses, caracterisations et lixiviation  

Energy Technology Data Exchange (ETDEWEB)

In the framework of the search for a ceramic material usable in the radioactive waste storage, uranium and thorium phosphates have been investigated. Their experimental synthesis conditions have been entirely reviewed, they lead to the preparation of four new compounds: U(UO{sub 2})(PO{sub 4}){sub 2}, U{sub 2}O(PO{sub 4}){sub 2}, UCIPO{sub 4}, 4H{sub 2}O, and Th{sub 4}(PO{sub 4}){sub 4}P{sub 2}O{sub 7}. Experimental evidenced are advanced for non existent compounds such as: U{sub 3}(PO{sub 4}){sub 4}, U{sub 2}O{sub 3}P{sub 2}O{sub 7} and Th{sub 3} (PO{sub 4}){sub 4}. Characterization by several techniques (X-rays and neutron powder diffractions, UV-Visible and Infra-red spectroscopies, XPS,...) were performed. The ab initio structure determination of U(UO{sub 2})(PO{sub 4}){sub 2} has been achieved by X-rays and refined by neutron diffractions. Through its physico-chemical analysis, we found that this compound was a new mixed valence uranium ...

1995-03-01

397

Technical-economic aspects of the utilization of geothermal waters  

International Nuclear Information System (INIS)

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

398

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

British Library Electronic Table of Contents (United Kingdom)

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

2011-01-01

399

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

British Library Electronic Table of Contents (United Kingdom)

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

2007-01-01

400

Scale prevention with special reference to threshold treatment  

Energy Technology Data Exchange (ETDEWEB)

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

1983-01-01

401

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-12-15

402

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

British Library Electronic Table of Contents (United Kingdom)

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

2011-01-01

403

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

International Nuclear Information System (INIS)

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

2010-09-01

404

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

International Nuclear Information System (INIS)

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

405

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

Energy Technology Data Exchange (ETDEWEB)

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

1980-05-29

406

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

British Library Electronic Table of Contents (United Kingdom)

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

2010-01-01

407

The separation and determination of trace elements in iron ore  

International Nuclear Information System (INIS)

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

2008-05-01

408

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

UK PubMed Central (United Kingdom)

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

1979-02-01

409

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

UK PubMed Central (United Kingdom)

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

2008-04-01

410

Research on the liquefaction of lignite by hydrogenation  

Energy Technology Data Exchange (ETDEWEB)

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

1985-01-01

411

Radioactive lead studies in the human  

International Nuclear Information System (INIS)

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

412

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

UK PubMed Central (United Kingdom)

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

1996-08-01

413

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

UK PubMed Central (United Kingdom)

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

2007-08-15

414

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

DEFF Research Database (Denmark)

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

1993-01-01

415

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

UK PubMed Central (United Kingdom)

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

1999-11-01

416

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

International Nuclear Information System (INIS)

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

2005-08-01

417

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

Science.gov (United States)

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

2011-03-29

418

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

Energy Technology Data Exchange (ETDEWEB)

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

1984-04-01

419

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

International Nuclear Information System (INIS)

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

420

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

UK PubMed Central (United Kingdom)

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

1994-07-01

421

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

Energy Technology Data Exchange (ETDEWEB)

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

2007-08-15

422

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

UK PubMed Central (United Kingdom)

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

423

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

UK PubMed Central (United Kingdom)

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

2009-04-01

424

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

UK PubMed Central (United Kingdom)

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

2009-06-01

425

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

Energy Technology Data Exchange (ETDEWEB)

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

1998-05-01

426

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

Energy Technology Data Exchange (ETDEWEB)

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

1993-01-01

427

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

Science.gov (United States)

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

2004-12-01

428

Agonist-directed trafficking of signalling at serotonin 5-HT2A, 5-HT2B and 5-HT2C-VSV receptors mediated Gq/11 activation and calcium mobilisation in CHO cells.  

Science.gov (United States)

Several examples of agonist-directed trafficking of receptor signalling at 5-HT2A and 5-HT2C receptors have been reported that involve independent downstream transduction pathways. We now report the functional selectivity of a series of chemically diverse agonists at human (h)5-HT2A, h5-HT2B and h5-HT2C-VSV by examining two related responses, the upstream activation of Gq/11 proteins in comparison with its associated cascade of calcium mobilisation. At the h5-HT2A receptor, d-lysergic acid diethylamide (LSD) and the antiparkinsonian agents lisuride, bromocriptine and pergolide exhibit a higher potency for Gq/11 activation than calcium release in contrast with all the other tested ligands such as 5-HT, mCPP and BW723C86, that show an opposite preference of signalling pathway. Comparable observations are made at h5-HT2B and h5-HT2C-VSV receptors, suggesting a similar mechanism of functional selectivity for the three serotonin receptors. ...

2008-07-30

429

Unusual carbon partitioning during phosphate deficiency in celery, a mannitol-synthesizing species  

Energy Technology Data Exchange (ETDEWEB)

Mannitol and sucrose are the main photosynthetic products and translocated carbon compounds in celery (Apium graveolens L.). Carbon partitioning was studied in greenhouse-grown celery plants supplied with a nutrient solution containing or lacking phosphate (P). P-deficient plants developed new leaves at about the same rate as control plants, but showed greatly reduced growth of leaves and petioles; root growth was apparently unaffected. P-deficient leaves contained less mannitol and more sucrose than control leaves. Starch content increased with P-deficiency only in mature (the most photosynthetically-active) leaves, and then amounted to less than 10 mg/g fresh weight. Similarly, when {sup 14}CO{sub 2} was supplied to intact plants, P-deficient leaves contained less label in mannitol and more in sucrose than did control leaves; labeling of starch changed little. The P-status of celery leaves apparently affects the partitioning of carbon between mannitol and sucrose ...

1989-04-01

430

The reduction of actinide ions by hydroxamic acids  

Science.gov (United States)

Simple hydroxamic acids have been shown to have useful applications in an Advanced Purex process for the reprocessing of irradiated nuclear fuel. They are especially suited to the separation of neptunium (IV) from uranium (VI) by the selective formation of a hydrophilic complex with Np(IV). U(VI) extraction in to 30% tributyl phosphate is unaffected. However, they have also been shown to be very fast reducing agents for Np(VI). The timescales of the reduction have been defined under a range of typical Purex Process conditions although the accurate determination of the reaction kinetics was not possible due to the rapidity of the reaction. U(VI) was shown not to be reduced. Therefore, Np(VI) can be efficiently reductively stripped when solvent phase (30% tributyl phosphate in odourless kerosene) solutions of Np(VI) and U(VI) are contacted with aqueous phase hydroxamic acid solutions. The slow reduction of plutonium (IV) to Pu(III) has also been ...

1999-01-01

431

Sucrose phosphate synthase activity in rice grown at elevated CO sub 2 and temperature  

Energy Technology Data Exchange (ETDEWEB)

Rice (Oryza sativa L.) was grown at 330 and 660 {mu}L CO{sub 2} L{sup {minus}1} and at 40/33/37, 34/27/31, and 28/21/25{degree}C day/night/paddy water temperatures respectively. Sucrose phosphate synthase (SPS) activity was measured at saturating substrate concentrations at 59 days after planting. SPS activity increased 2 and 3 fold with increasing CO{sub 2} at 28 and 34{degree}C air temperatures respectively. At 40{degree}C SPS activity decreased by 37% at elevated CO{sub 2} and most plants failed to reach maturity. Similar responses were found in leaf samples taken in the dark. These results indicate that SPS, an enzyme involved in the regulation of C partitioning in leaves, increases in activity at elevated CO{sub 2}. This is in contrast to previous results with soybean. The changes in SPS activity will also be discussed in relation to leaf starch/sucrose ratios.

1990-05-01

432

Research on development of adsorbent for separating and collecting light element isotopes  

International Nuclear Information System (INIS)

Lithium isotopes are used as the raw material of tritium which is the fuel for fusion power generation and the material for fusion reactors, accordingly those are indispensable for future nuclear fusion power generation. As for boron isotopes, the neutron absorption corss section is very large, therefore, they are used for shielding neutrons and controlling fast neutron reactors. In order to further develop the utilization of nuclear power, it is important to develop the technology for separating and refining light element isotopes in large amount. In fiscal year 1995, the relation of the ion sieve characteristics of inorganic ion exchanger and the behavior of lithium isotope separation was examined. The behavior of forming boron complex of polyol amine was examined by B-11 NMR. These experiments and the results are reported. It was shown to be feasible that lithium is adsorbed from seawater, and isotopes are concentrated. Titanium phosphate and its heat treated ...

433

Rapid toxicity testing based on mitochondrial respiratory activity  

Energy Technology Data Exchange (ETDEWEB)

The need exists for rapid and inexpensive methods to determine the health effects of environmental contaminants on biological systems. One of the current research approaches for assessing cytotoxicity is to monitor the respiratory activity of the mitochondrion, a sensitive, nonspecific subcellular target site. Detected changes in mitochondrial function after the addition of a test chemical could be correlated to toxic effects. Mitochondrial respiration can be characterized by three indices: state 3 and state 4 respiratory rates, and the respiratory control ratio (RCR). State 4, the idle or resting state, results when coupled mitochondrial respire in a medium containing inorganic phosphate and a Kreb's cycle substrate in the absence of a phosphate acceptor such as adenosine diphosphate (ADP). In the presence of ADP the respiration rate increases to a maximum (state 3), accompanied by phosphorylation of ADP to adenosine triphosphate ...

1990-05-01

434

Lithium ion conductive glass?ceramics with Li3Fe2(PO4)3 and YAG laser-induced local crystallization in lithium iron phosphate glasses  

British Library Electronic Table of Contents (United Kingdom)

The glasses with the composition of 37.5Li2O?(25?x)Fe2O3?xNb2O5?37.5P2O5 (mol%) (x=5,10,15) are prepared, and it is found that the addition of Nb2O5 is effective for the glass formation in the lithium iron phosphate system. The glass?ceramics consisting of Nasicon-type Li3Fe2(PO4)3 crystals with an orthorhombic structure are developed through conventional crystallization in an electric furnace, showing electrical conductivities of 3?10?6?Scm?1 at room temperature and the activation energies of 0.48?eV (x=5) and 0.51?eV (x=10) for Li+ ion conduction in the temperature range of 30?200??C. A continuous wave Nd:YAG laser (wavelength: 1064?nm) with powers of 0.14?0.30?W and a scanning speed of 10??m/s is irradiated onto the surface of the glasses, and the formation of Li3Fe2(PO4)3 crystals is c...

2008-01-01

435

LiPF{sub 6}. Synthesis and stability in EC/DMC and PC/DMC mixtures; LiPF{sub 6}. Synthese et stabilite dans les melanges EC/DMC et PC/DMC  

Energy Technology Data Exchange (ETDEWEB)

Lithium hexa-fluoro-phosphate LiPF{sub 6} is recommended for the replacement of the toxic LiAsF{sub 6} and the explosive perchlorates (like LiClO{sub 4}) in rechargeable lithium electrochemical generators. The aim of this work is to develop a new method of synthesis of this salt and to check its stability with respect to carbonated solvents: ethylene carbonate (EC), propylene carbonate (PC) and dimethyl-carbonate (DMC) in already optimized EC/DMC and PC/DMC binary mixtures. Two methods using HPF{sub 6} are proposed: the first one uses the direct neutralization of this commercial acid by LiOH in aqueous, alcoholic or acetonitrile environment, while in the second one LiPF{sub 6} is obtained from pyridinium hexa-fluoro-phosphate synthesized from HPF{sub 6} using a new and simple protocol. (J.S.) 24 refs.

1996-12-31

436

Hybrid porous phosphate heterostructures as adsorbents of Hg(II) and Ni(II) from industrial sewage  

British Library Electronic Table of Contents (United Kingdom)

Porous phosphate heterostructures (PPH), functionalized with different ratios of aminopropyl and mercaptopropyl groups, labelled as Nx=5,25,50-PPH and Sx=5,25,50-PPH, respectively, were tested as adsorbents for Ni(II) and Hg(II) found in industrial sewage from electroplating processes and button battery recycling. X-ray diffraction was used to study the structures. The specific surface area of the pristine material (PPH) was 620m^2g^-^1, whereas the specific surface areas of the modified mercaptopropyl (S5-PPH) and aminopropyl (N5-PPH) were 472 and 223m^2g^-^1, respectively. The adsorption data were fitted to a Langmuir isotherm model. The S5-PPH material was saturated by 120mmol Hg(II) per 100g of material, whereas for Ni(II) adsorption, N25-PPH material displayed the highest adsorption w...

2011-01-01

437

Genetic engineering of group 2 sigma factor SigE widely activates expressions of sugar catabolic genes in Synechocystis species PCC 6803.  

Science.gov (United States)

Metabolic engineering of photosynthetic organisms is required for utilization of light energy and for reducing carbon emissions.Control of transcriptional regulators is a powerful approach for changing cellular dynamics, because a set of genes is concomitantly regulated. Here, we show that overexpression of a group 2 ? factor, SigE, enhances the expressions of sugar catabolic genes in the unicellular cyanobacterium, Synechocystis sp. PCC 6803. Transcriptome analysis revealed that genes for the oxidative pentose phosphate pathway and glycogen catabolism are induced by overproduction of SigE. Immunoblotting showed that protein levels of sugar catabolic enzymes, such as glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, glycogen phosphorylase, and isoamylase, are increased. Glycogen levels are reduced in the SigE-overexpressing strain grown under light. Metabolome analysis revealed that metabolite levels of the TCA cycle and ...

2011-07-11

438

Fluorimetric study of the interaction between nicotinamide adenine dinucleotide phosphate and tetracycline-europium complex and its application  

Energy Technology Data Exchange (ETDEWEB)

A new spectrofluorimetric method was developed for the determination of trace amount of nicotinamide adenine dinucleotide phosphate (NADP). Using europium (Eu{sup 3+})-tetracycline (TC) complex as a fluorescent probe, in the buffer solution of pH 7.60. NADP can remarkably enhance the fluorescence intensity of the Eu{sup 3+}-TC complex at {lambda} = 612 nm and the enhanced fluorescence intensity of Eu{sup 3+} ion is in proportion to the concentration of NADP. Optimum conditions for the determination of NADP were also investigated. The dynamic range for the determination of NADP is 4.4 x 10{sup -7} to 2.2 x 10{sup -6} mol l{sup -1} with detection limit of 6.9 x 10{sup -8} mol l{sup -1}. This method is simple, practical and relatively free interference from coexisting substances and can be successfully applied to determination of NADP in synthetic water samples and in serum samples. Moreover, the enhancement mechanisms of the fluorescence intensity in the Eu{sup ...

2005-09-06

439

Enhancement of glass-forming ability and bio-corrosion resistance of Zr-Co-Al bulk metallic glasses by the addition of Ag  

International Nuclear Information System (INIS)

A novel Ni and Cu-free Zr-based bulk metallic glass (BMG) system with enhancement of glass-forming ability (GFA) and bio-corrosion resistance was prepared by copper mold casting by the addition of Ag. It was found that the addition of Ag can considerably enhance the glass-forming ability, as indicated by the increase of the critical glass dimension from 3 mm diameter of the ternary system to over 10 mm in the alloy of Zr_5_3Co_1_8_._5Al_2_3_._5Ag_5. The bio-corrosion behaviors of the Zr-based BMGs in phosphate buffered solution (PBS) were investigated by electrochemical polarization at 310 K. It was found that the addition of appropriate amount of Ag can enhance the corrosion resistance of the BMGs. The X-ray photoelectron spectroscopy (XPS) indicated that the formation of an Al_2O_3-enriched passive film is mainly responsible for the high corrosion resistance of Ag-bearing alloy in phosphate buffered solution.

2010-08-01

440

Batch test equilibration studies examining the removal of Cs, Sr, and Tc from supernatants from ORNL underground storage tanks by selected ion exchangers  

Energy Technology Data Exchange (ETDEWEB)

Bench-scale batch equilibration tests have been conducted with supernatants from two underground tanks at the Melton Valley Storage Tank (MVST) Facility at Oak Ridge National Laboratory (ORNL) to determine the effectiveness of selected ion exchangers in removing cesium, strontium, and technetium. Seven sorbents were evaluated for cesium removal, nine for strontium removal, and four for technetium removal. The results indicate that granular potassium cobalt hexacyanoferrate was the most effective of the exchangers evaluated for removing cesium from the supernatants. The powdered forms of sodium titanate (NaTiO) and cystalline silicotitanate (CST) were superior in removing the strontium; however, for the sorbents of suitable particle size for column use, titanium monohydrogen phosphate (TiHP {phi}), sodium titanate/polyacrylonitrile (NaTiO-PAN), and titanium monohydrogen phosphate/polyacrylonitrile (TiP-PAN) gave the best results and were about ...

1995-06-01

441

A procedure for batch separation of sup 14 C-hexose from sup 14 C-sucrose  

Energy Technology Data Exchange (ETDEWEB)

This presentation describes a method for separating {sup 14}C-hexose from {sup 14}C-sucrose in extracts of plant tissue. Portions of ethanol extracts are treated with activated charcoal in microcentrifuge tubes. Aliquots are removed, ethanol evaporated and replaced with reaction mixture that phosphorylates hexose (HEPPS, K{sub 2}HPO{sub 4}, Mg(C{sub 2}H{sub 3}O{sub 2}){sub 2}, ovalbumen, Na{sub 2}ATP, yeast hexokinase). After a time course, the hexokinase reaction is stopped (slowed considerably) to minimize effects of contamination enzyme activities. The stopping agent used is lyxose, a nonphosphorylable analogue of glucose. The strong anionic charge of phosphate introduced through the hexokinase action results in binding (> 95%) of hexose-phosphate to anion-exchange resin. Sucrose remains unbound (> 95%) in solution. This batch ion-exchange is performed in microcentrifuge tubes to allow many samples to be processed simultaneously. ...

1991-05-01

442

Wastewater treatment of industrial effluent using activated dolomite adsorption  

Environmental Research Database

SummaryInitial results from the use of activated dolomite from QUESTOR project L1 have proved extremely encouraging in terms of metallic ion (also phosphate, nitrate and dye) removal from wastewater, with capacities in some instances in excess of commercially available activated carbons.This new project involves investigating actual plant effluent in laboratory scale columns and the design of a pilot scale rig for on site trials. The project also involves investigating disposal options and an economic [continued...

2007-01-01

443

Synthesis of high specific activity tritium labelled [2-{sup 3}H]-adenosine-5`-triphosphate  

Energy Technology Data Exchange (ETDEWEB)

A procedure for high level tritium labelling at the C2-H position of adenosine 5`-triphosphate ([2-{sup 3}H]-ATP, 1), based on the tritiodehalogenation reaction of 2-bromoadenosine 5`-triphosphate (2) has been elaborated. This precursor was prepared in a six-step synthesis from guanosine. The tritiodehalogenation of (2) for three hours over palladium oxide in phosphate buffer yielded tritium labelled ATP with high specific activity, in good chemical yield. (author).

1996-08-01

444

Solubility and rate of dissolution for Miscanthus in hydrophilic ionic liquids  

British Library Electronic Table of Contents (United Kingdom)

Miscanthus is a potential feedstock for the production of biofuels. Lignocellulosic biomass is not soluble in conventional solvents, but Miscanthus and other lignocellulosic biomass have reasonable solubilities in some ionic liquids. The solubility of Miscanthus in a variety of hydrophilic ionic liquids was measured as a function of particle size, temperature and time for dissolution. In addition to temperature and time, the ionic liquid anion has a significant effect on solubility and rate of dissolution. The moisture content of Miscanthus lowers its solubility in certain ionic liquids. Chloride, acetate, and phosphate-based ionic liquids favor solubility. A tentative correlation for the solubility of Miscanthus is proposed in terms of Abraham solvation parameters obtained from quantum-ch...

2011-01-01

445

Production of the radioisotope "8"8Y  

International Nuclear Information System (INIS)

Carrier-free "8"8Y radioisotope, which has the longest half life (T=106.6 d) of yttrium radioisotopes and is a #gamma#-ray emitter, was obtained by proton irradiation of strontium, followed by cooling for one month. Then, "8"8Y was purified by precipitating strontium as strontium nitrate and extracting yttrium with tri-n-butyl phosphate (TBP). The decontamination factor of strontium to yttrium was more than 4x10"3 and chemically pure yttrium radioisotope was obtained. (author) 6 refs.

446

Preparation of poly (aryl ether ketones) in the presence of an alkali, alkaline earth of lanthanide metal salt  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a process for preparing poly(aryl ether ketones) by nucleophilic displacement polymerization in the presence of at least one alkali metal base selected from potassium, rubidium or cesium, and fluoride ions, which comprises adding to the polymerization: (a) an effective amount of at least one metal salt selected from lithium, sodium, alkaline earth or lanthanide chloride, bromide, iodide, sulfate, alkyl or aryl carboxylate, cyanide, borate or phosphate to slow or stop advancement of molecular weight and (b) an end-capping agent.

1988-09-27

447

Orthophosphoric acid interactions with ultrastable zeolite Y: Infrared and NMR studies  

Energy Technology Data Exchange (ETDEWEB)

Zeolite Y is the active component of most commercial cracking catalysts. Interaction of H[sub 3]PO[sub 4] with extraframework aluminum of ultra-stable zeolite (USY) leads to the formation of different types of aluminum phosphates, while there is no indication of the formation of SAPO zeotype structures. The total acidity of USY slightly decreases upon the H[sub 3]PO[sub 4] treatment, while the maximum in the distribution of acid strength is shifted to milder acidities. Dealumination of the zeolite and creation of POH sites associated with AIPO[sub 4] are responsible for the modifications observed. 37 refs., 8 figs., 3 tabs.

1994-01-01

448

Electrochemical behavior of Alloy 800 under steam generators temperature and pressure conditions comparison, based on (I,E) polarization curves, with 316L and A533B steels  

Energy Technology Data Exchange (ETDEWEB)

We propose a dissolution-passivation model to account for the electrochemical behavior of Alloy 800 and 316L stainless steel under steam generators operating conditions. This model is similar to the one defined for nickel, considering the known importance of this element on the studied alloys. The comparison of the rates of the elementary steps points out the favorable influence of dissolved oxygen and phosphate ions on the dissolution of Alloy 800, even in the presence of chloride ions. The sensitivity of 316L SS is greater, especially because of the lowest stability of oxide-like intermediate.

1992-12-31

449

Electrochemical behavior of Alloy 800 under steam generators temperature and pressure conditions comparison, based on (I,E) polarization curves, with 316L and A533B steels  

International Nuclear Information System (INIS)

We propose a dissolution-passivation model to account for the electrochemical behavior of Alloy 800 and 316L stainless steel under steam generators operating conditions. This model is similar to the one defined for nickel, considering the known importance of this element on the studied alloys. The comparison of the rates of the elementary steps points out the favorable influence of dissolved oxygen and phosphate ions on the dissolution of Alloy 800, even in the presence of chloride ions. The sensitivity of 316L SS is greater, especially because of the lowest stability of oxide-like intermediate.

1991-08-25

450

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

Energy Technology Data Exchange (ETDEWEB)

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

2003-07-01

451

Synthesis and crystal structure of a new open-framework iron phosphate (NH4)4Fe3(OH)2F2[H3(PO4)4]: Novel linear trimer of corner-sharing Fe(III) octahedra  

International Nuclear Information System (INIS)

A new iron phosphate (NH4)4Fe3(OH)2F2[H3(PO4)4] has been synthesized hydrothermally at HF concentrations from 0.5 to 1.2 mL. Single-crystal X-ray diffraction analysis reveals its three-dimensional open-framework structure (monoclinic, space group P21/n (No. 14), a=6.2614(13) A, b=9.844(2) A, c=14.271(3) A, ?=92.11(1)o, V=879.0(3) A3). This structure is built from isolated linear trimers of corner-sharing Fe(III) octahedra, which are linked by (PO4) groups to form ten-membered-ring channels along [1 0 0]. This isolated, linear trimer of corner-sharing Fe(III) octahedra, [(FeO4)3(OH)2F2], is new and adds to the diverse linkages of Fe polyhedra as secondary building units in iron phosphates. The trivalent iron at octahedral sites for the title compound has been confirmed by synchrotron Fe K-edge XANES spectra and magnetic measurements. Magnetic measurements also show that this compound exhibit a strong antiferromagnetic exchange below TN=17 K, ...

2010-12-01

452

Physical basis of the effect of hemoglobin on the "3"1P NMR chemical shifts of various phosphoryl compounds  

International Nuclear Information System (INIS)

The marked difference between the intra- and extracellular "3"1P NMR chemical shifts of various phosphoryl compounds when added to a red cell suspension may be largely understood in terms of the effects of hemoglobin on the "3"1P NMR chemical shifts. The presence of [oxy- or (carbonmonoxy)-] hemoglobin inside the red cell causes the bulk magnetic susceptibility of the cell cytoplasm to be significantly less than that of the external solution. This difference is sufficient to account for the difference in the intra- and extracellular chemical shifts of the two phosphate esters trimethyl phosphate and triethyl phosphate. However, in the case of the compounds dimethyl methylphosphonate, diethyl methylphosphonate, and trimethylphosphine oxide as well as the hypophosphite, phenylphosphinate, and diphenylphosphinate ions, hemoglobin exerts an additional, much larger, effect, causing the "3"1P NMR resonances to shift to lower ...

453

Chemical Makeup of Microdamaged Bone Differs from Undamaged Bone  

International Nuclear Information System (INIS)

Microdamage naturally occurs in bone tissue as a result of cyclic loading placed on the body from normal daily activities. While it is usually repaired through the bone turnover process, accumulation of microdamage may result in reduced bone quality and increased fracture risk. It is unclear whether certain areas of bone are more susceptible to microdamage than others due to compositional differences. This study examines whether areas of microdamaged bone are chemically different than undamaged areas of bone. Bone samples (L3 vertebrae) were harvested from 15 dogs. Samples were stained with basic fuchsin, embedded in poly-methylmethacrylate, and cut into 5-(micro)m-thick sections. Fuchsin staining was used to identify regions of microdamage, and synchrotron infrared microspectroscopic imaging was used to determine the local bone composition. Results showed that microdamaged areas of bone were chemically different than the surrounding undamaged areas. Specifically, the mineral ...

2006-01-01

454

"1H and "3"1P nuclear magnetic resonance investigation of the interaction between 2,3-diphosphoglycerate and human normal adult hemoglobin  

International Nuclear Information System (INIS)

High-resolution "1H and "3"1P nuclear magnetic resonance spectroscopy has been used to investigate the binding of 2,3-diphosphoglycerate to human normal adult hemoglobin and the molecular interactions involved in the allosteric effect of the 2,3-diphosphoglycerate molecule on hemoglobin. Individual hydrogen ion NMR titration curves have been obtained for 22-26 histidyl residues of hemoglobin and for each phosphate group of 2,3-diphosphoglycerate with hemoglobin in both the deoxy and carbonmonoxy forms. The results indicate that 2,3-diphosphoglycerate binds to deoxyhemoglobin at the central cavity between the two #beta# chains and the binding involves the #beta#2-histidyl residues. Moreover, the results suggest that the binding site of 2,3-diphosphoglycerate to carbonmonoxyhemoglobin contains the same (or at least some of the same) amino acid residues responsible for binding in the deoxy form. As a result of the specific interactions with 2,3-diphosphoglycerate, the ...

455

Use of post-consumer waste plastics in cement-based composites  

Energy Technology Data Exchange (ETDEWEB)

This paper describes an innovative use of post-consumer waste HDPE plastic in concrete as a soft filler. A reference concrete was proportioned to have the 28-day compressive strength of 5000 psi (35 MPa). A high-density plastic was shredded into small particles for use in the concrete. These particles were subjected to three chemical treatments (water, bleach, bleach + NaOH) to improve their bonding with the cementitious matrix. The plastic particles were added to the concrete in the range of 0--5% of total mixture by weight. Compressive strengths were measured for each test mixture. The results showed that chemical treatment has a significant effect on performance of the plastic filler in concrete. Of the three treatments used on the plastic, the best performance was observed with the alkaline bleach treatment (bleach + NaOH) with respect to compressive strength of concrete.

1996-10-01

456

Removal of short range order minerals prior to grain size analysis of volcanic ash soils  

British Library Electronic Table of Contents (United Kingdom)

Abstract Incomplete dispersion of aggregates is a well known difficulty when analyzing soil texture of Andosols, particularly if no fresh soil material is available. To facilitate such investigations, several dispersion procedures were carried out on air dried samples rich in short range order minerals, originating from selected Andosol profiles (S Mexico). As a result, we propose an improved method based on a sequential chemical treatment with K oxalate, NH4 oxalate, and oxalic acid that reliably removes cementing agents and allows for a stable dispersion of soil particles after addition of Na pyrophosphate. This method was proved to be well reproducible and highly reliable for routine grain size determinations. The potential error caused by the inherent risk of dissolving primary mineral...

2010-01-01

457

Problematic of atmospheric pollution in Lebanon: the better stake is apprehended, the best acts are taken  

International Nuclear Information System (INIS)

Lebanon has imported in 1996 5000 Kt of carburants causing about 80 Kt of SO_x; 40 Kt of NO_x; 3 Kt of dusts and 3.5 million tons of CO_2. The atmospheric pollution in Lebanon is due to three main sources: - Thermal central of electric production - Industries (cement) - Transportation sector The document describes in tables: the inventory of pollutants and pollutant emissions in 1993 and 2010; industrial and heating gas oil; liquified petroleum gas commercial propane; fuel oil for EDL; consumption of energy in 1996; sectorial distribution of pollutants PPM; emissions of CO_2 per tons per habitant in 1993; consumption in 1993 broken down by use and application. Finally, three projects concerning public transportation were presented

1999-06-02

458

Problematic of atmospheric pollution in Lebanon: the better stake is apprehended, the best acts are taken  

International Nuclear Information System (INIS)

The document presents an overview on atmospheric pollution in Lebanon, with an analysis of sources of pollution, their impact on local and global environment and their control.Local causes of pollution are mainly: -Thermal power plants of electric power production which produce 75% SO_2 emission and 60% dust - Industries, especially cement industry - Land transportation which produces 70% NOX emission and 50% CO_2 A description of air pollution caused by these three sectors is revealed. Pollutants derived from fuel combustion are analyzed. It is estimated that in 2010, Co_2 emission will reach 5204450 tons, SO_2 emission will be 136470 tons, NOX emissions 96870 and dust estimated to 4130 tons. CFC consumption and measures of control according to Montreal Protocol are described. Recommendations for control of air pollution in Lebanon within a national policy are presented.

459

Insitu Assessment of Contaminant Containment Systems  

Environmental Research Database

Objectives(1) Evaluate various insitu techniques for determination of the permeability of slurry walls and investigate the extent of material disturbance and fracturing during drilling and testing.~%~~%~(2) Perform laboratory tests of block samples obtained from the field testing site and compare the results with field measurements.~%~~%~(3) Investigate the mechanisms of drilling using a newly developed instrumented self-boring device and develop a theoretical framework for drilling mechanisms in soils.~% [continued...]DescriptionCement-bentonite and clay liner systems are used as components of containment systems by the environmental industry to control the migration of pollution. In the interest of public safety, following construction, there is a requirement to test these structures in orde to assess if they meet the design critetia. At present this is done only indirectly via laboratory testing on samples obtained from the ...

2006-01-30

460

Genesis of the Jurassic Carbonate-Hosted Pb-Zn Deposits of Jebel Ressas (North-Eastern Tunisia): Evidence from Mineralogy, Petrography and Trace Metal Contents and Isotope (O, C, S, Pb) Geochemistry  

British Library Electronic Table of Contents (United Kingdom)

Abstract The Jebel Ressas Pb-Zn deposits in North-Eastern Tunisia occur mainly as open-space fillings (lodes, tectonic breccia cements) in bioclastic limestones of the Upper Jurassic Ressas Formation and along the contact of this formation with Triassic rocks. The galena-sphalerite association and their alteration products (cerussite, hemimorphite, hydrozincite) are set within a calcite gangue. The Triassic rocks exhibit enrichments in trace metals, namely Pb, Co and Cd enrichment in clays and Pb, Zn, Cd, Co and Cr enrichment in carbonates, suggesting that the Triassic rocks have interacted with the ore-bearing fluids associated with the Jebel Ressas Pb-Zn deposits. The 18O content of calcite associated with the Pb-Zn mineralization suggests that it is likely to have precipitated from a fl...

2011-01-01

461

Fracture Resistance of Metal Ceramic Restorations with Two Different Margin Designs After Exposure to Masticatory Simulation  

British Library Electronic Table of Contents (United Kingdom)

Statement of problem Although the esthetic outcome of a collarless metal ceramic restoration is superior to that of a restoration with a metal margin, its mechanical strength has not been evaluated. Purpose The purpose of this study was to evaluate and compare the fracture resistance of metal ceramic restorations with metal margins to that of metal ceramic restorations with circumferential porcelain margins, after exposure to masticatory simulation. Material and methods Twenty-four metal ceramic restorations were fabricated and paired with 24 cobalt-chrome tooth analogs. Twelve of the specimens had metal margins, while the remainder had circumferential porcelain margins. The restorations were cemented on the metal tooth analogs with a resin-modified glass ionomer luting agent (FujiCEM). Al...

2009-01-01

462

Explosives solve downhole problems  

Energy Technology Data Exchange (ETDEWEB)

Shaped charges were first used more than 30 years ago to perforate casing, cement sheath and reservoir to provide selective communication between the reservoir and well bore. Since then, advances have been made in design of shaped charge sand ancillary equipment. Penetration has increased considerably. Miniaturization of equipment allows passing through relatively small restrictions and effectively communicating with reservoirs. Gun debris has been drastically reduced and in some designs eliminated. Deep reservoirs can be effectively penetrated under down-hole environments exceeding 500 F and 20,000 psi. This work covers the problems encountered and reviews successful devices employing shaped charge and explosive technology.

1981-11-01

463

Evaluation of the long-term mechanical behavior in the near-fields considering chemical transitions of barrier materials  

International Nuclear Information System (INIS)

An analysis system for the long-term mechanical behavior of barrier materials (MACBECE: Mechanical Analysis system considering Chemical transitions of BEntonite-based and CEment-based materials) was developed in order to improve the reliability of the evaluation of the hydraulic field which is one of the important environmental conditions in the safety assessment of the TRU waste disposal. MACBECE is the system that calculates the deformation of barrier materials using their chemical property changes as inputs, and subsequently calculates their hydraulic conductivity taking both their chemical property changes and deformation into consideration. By using MACBECE, the long-term deformation and the transition of hydraulic field for the round-type disposal cavities were evaluated, assuming some sets of chemical evolution data as input. Based on the analysis result, it is considered that the influence of the long-term deformation of the barrier materials on the nuclide ...

2007-04-22

464

Desulphurisation of fumes as a potential source of prime materials  

Energy Technology Data Exchange (ETDEWEB)

A survey is given by the authors of methods of removing the sulphur dioxide content of fumes which can be linked together with producing useful final products. From these technologies those suppling well utilizable gypsum, the Walther process, producing ammonium sulphate, the Wellman-Lord and Bergbau-Forschung processes, respectively adapted to produce sulphuric acid or sulphur, may be of interest. Also in the method of fumes desulphurisation by catalysis by manganese, developed in KBFI, utilizable final products are given. Background of the work of developing this method. Detailed description of the manganese catalytic method based on the use of a red mud desulphurizing agent. By this process, in addition to desulphurizing fumes, enriched red mud with reduced Na/sub 2/O content is produced, which as an iron carrier, is to be reckoned with, or to be used in the cement industry for replacing imported calcined pyrites.

1986-01-01

465

Coal development potential in Pakistan  

Energy Technology Data Exchange (ETDEWEB)

A total of 48 papers were presented, and covered the following topics: the current situation in Pakistan with respect to development and utilization of coal resources; the policies that have been responsible for the development and utilization of coal resources in Pakistan; coal development and utilization in other developing nations e.g. Indonesia, Greece, Philippines, China, Thailand and Haiti; and technological developments in coal exploration; extraction, handling, transport and utilization which could accelerate future development of Pakistan's coal resources. Specific subjects covered include the use of coal in the cement industry of Pakistan; the production of briquettes for domestic use, development and training of personnel for the coal industry; and sources of finance for coal development projects. Particular emphasis is given throughout the conference to the Lakhra coal mine/power plant project which aims to develop and effectively utilize the ...

1986-01-01

466

Bottom barrier by new soil improvement method, Superjet{sup {trademark}}, to confine vertical plume of contamination  

Energy Technology Data Exchange (ETDEWEB)

The first task for remediation actions against underground contamination should be an effective confinement of contamination plumes. Some conventional barrier techniques have been already proved to have sufficient features to prevent such plumes from extending horizontally, but further technical development is required to construct a bottom barrier to stop plumes going deeper. Superjet{sup {trademark}} is a powerful version of the jet grouting method (1) and is characterized by prompt construction of an underground cement pile when exceeds 5 meter in diameter. Its application to a case of construction of underground lapping beams has shown satisfactory completion to sustain underground open space. The results and some basic experiments indicate that this method is technically feasible to build a bottom barrier with a certain mechanical strength.

1994-12-31

467

Dynamic {sup 31}P-MR-spectroscopy of the quadriceps muscle. Influence of sex and age on spectroscopic results; Die dynamische 31-Phosphor-Magnetresonanz-Spektroskopie des M. quadriceps. Einfluss von Geschlecht und Alter auf spektroskopische Parameter  

Energy Technology Data Exchange (ETDEWEB)

Purpose: {sup 31}P-MRS is used to assess the influence of sex and age on quadriceps muscle metabolism before and after exercise. Materials and Methods: 32 healthy volunteers (15 women, 17 men; mean age: 38{+-}17 yrs.) were examined by dynamic phosphorus-31 ({sup 31}P) magnetic resonance spectroscopy (MRS). In the magnet, the quadriceps muscle was stressed by an isometric and an isotonic form of exercise until exhaustion, respectively. Results: Resting conditions: With increasing subjects` age, the ratio {beta}-adenosine triphosphate/total phosphate decreased (r=-0.37; p=0.02). With increasing subjects` age, the ratios inorganic phosphate/phosphocreatine (r=0.79; p=5x10{sup -8}), phosphomonoester/{beta}-adenosine triphosphate (r=0.74; p=10{sup -6}) and phosphodiester/{beta}-adenosine triphosphate (r=0.62; p=10{sup -4}) increased. The pH was the only one of the evaluated spectroscopic parameters which showed a sex-dependence: Female subjects had ...

1999-05-01

468

{sup 3}H-tetracycline as a proxy for {sup 41}Ca for measuring dietary perturbations of bone resorption  

Energy Technology Data Exchange (ETDEWEB)

Our group is interested in evaluating early effects of dietary interventions on bone loss. Postmenopausal women lose bone following reduction in estrogen which leads to increased risk of fracture. Traditional means of monitoring bone loss and effectiveness of treatments include changes in bone density, which takes 6 months to years to observe effects, and changes in biochemical markers of bone turnover, which are highly variable and lack specificity. Prelabeling bone with {sup 41}Ca and measuring urinary {sup 41}Ca excretion with accelerator mass spectrometry provides a sensitive, specific, and rapid approach to evaluating effectiveness of treatment. To better understand {sup 41}Ca technology as a tool for measuring effective treatments on reducing bone resorption, we perturbed bone resorption by manipulating dietary calcium in rats. We used {sup 3}H-tetracycline ({sup 3}H-TC) as a proxy for {sup 41}Ca and found that a single dose is feasible to study bone ...

2007-06-15

469

The use of calcium silicate bricks for retrospective dosimetry  

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 ...

2004-02-01

470

Production of hydrogen by radiolysis  

Energy Technology Data Exchange (ETDEWEB)

The possibility of obtaining high yields of hydrogen through the exposure of calcium hydroxide to natural uranium fission fragments is confirmed experimentally. The amounts of hydrogen obtained in some experiments were determined not only from the mass-spectrometry data, but also with the use of standard chemical analysis methods. The radiolytic hydrogen yield averaged over six independent experiments comprises 20.41 hydrogen molecules per 100 eV of absorbed fission fragment energy. The corresponding energy efficiency makes up to 60.62. Since on interaction with water or water vapor calcium hydroxide enters into the exothermal reaction to liberate 15.6 kcal/mole, it can easily be regenerated; this was attested to by one of irradiation experiments. Therefore, in the long run, we are dealing with a radiolytic decomposition of water at low temperatures or at temperatures readily available with modern reactor engineering techniques. Comparison of ...

1998-07-01

471

Macroscopic consequences of calcium signaling in microdomains: A first passage time approach  

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 ...

2007-01-01

472

Lead and calcium distributions in blood, plasma, and milk of the lactating mouse  

Energy Technology Data Exchange (ETDEWEB)

Although it has been established that lead is transferred in milk from mother to suckling offspring, the physiological processes and parameters involved are not well understood. Single i.v. doses (0.2 mg/kg) or p.o. doses (2 mg/kg) of radiolabeled lead were administered to lactating and nonlactating female mice, and lead concentrations in blood, plasma, and milk were determined during a 21-day period. Large differences in lead elimination were observed between lactating and nonlactation mice. A significant fraction (25%) of the initial maternal dose (absorbed dose) was transferred to the suckling pups. The ratio of lead concentration in milk to lead concentration in plasma was found to be nearly constant over time. However, the milk-to-blood concentration ratios decreased during the same period. Furthermore, the concentration of lead in milk exceeded the plasma concentration by a factor of approximately 25, indicating that there is a physiological process(es) which establishes a large ...

1980-01-01

473

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

Science.gov (United States)

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

1974-01-01

474

Comparison of intrinsic and extrinsic tracer methods for estimating calcium bioavailability to rats from dairy foods  

International Nuclear Information System (INIS)

Dairy products doubly labeled with 45Ca and 47Ca were used to evaluate an extrinsic labeling procedure for calcium bioavailability determination. Nonfat milk, yogurt, and fresh cheese curd were prepared from caprine milk that was intrinsically labeled with 45Ca. The products were then labeled extrinsically with 47Ca and administered to rats by gavage. The 47Ca to 45Ca ratio in bone and teeth averaged about 1.00 with either milk, yogurt, or CaCl2, but the ratio was about 1.04 when dosed with cheese curd. Ca absorption, determined by whole-body counting of 47Ca, was lower (P less than 0.05) in cheese curd (59%) than in either milk (69%), yogurt (72%), or CaCl2 (72%). Expressed as percent of dose, the absorption of 47Ca was highly correlated with bone 47Ca (r = 0.973) and with bone 45Ca (r = 0.946). Correlation between tibia 47Ca and tibia 45Ca was r = 0.923. For the dairy products tested, our results indicated that extrinsic 47Ca was absorbed similarly to intrinsic ...

475

Analysis of lagoon sludge characteristics for choice of treatment process  

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 ...

2002-04-01

476

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

Science.gov (United States)

The aim of this study was to observe both the clinical signs and symptoms of wounds at risk of infection, that is critically colonised (biofilm infected) and antimicrobial-performance of an ionic silver alginate/carboxymethylcellulose (SACMC) dressing, in comparison with a non silver calcium alginate fibre (AF) dressing, on chronic venous leg and pressure ulcers. Thirty-six patients with venous or pressure ulcers, considered clinically to be critically colonised (biofilm infected), were randomly chosen to receive either an SACMC dressing or a non silver calcium AF dressing. The efficacy of each wound dressing was evaluated over a 4-week period. The primary study endpoints were prevention of infection and progression to wound healing. The SACMC group showed a statistically significant (P = 0.017) improvement to healing as indicated by a reduction in the surface area of the wound, over the 4-week study period, compared with AF controls. In ...

2010-05-31

477

Immobilization of chloride-rich radioactive wastes produced by pyrochemical operations  

Energy Technology Data Exchange (ETDEWEB)

A a result of its former role as a producer of nuclear weapons components, the Rocky Flats Environmental Technology Site (RFETS), Golden, Colorado accumulated a variety of plutonium-contaminated materials. When the level of contamination exceeded a predetermined level (the economic discard limit), the materials were classified as residues rather than waste and were stored for later recovery of the plutonium. Although large quantities of residues were processed, others, primarily those more difficult to process, remain in storage at the site. It is planned for the residues with lower concentrations of plutonium to be disposed of as wastes at an appropriate disposal facility, probably the Waste Isolation Pilot Plant (WIPP). Because the plutonium concentration is too high or because the physical or chemical form would be difficult to get into a form acceptable to WIPP, it may not be possible to dispose of a portion of the residues at WIPP. The pyrochemical salts are among the residues ...

1997-08-01

478

Depositional environment and petrographic and seismic interpretation of B Sandstone (a primary, waterflood, and enhanced recovery target), Olive Field, southwestern Mississippi  

Energy Technology Data Exchange (ETDEWEB)

Olive field is oil productive from a thin stratigraphically trapped sandstone within the Upper Cretaceous lower Tuscaloosa Formation. The discovery of Olive in 1981 led to renewed interest in the Mid-Dip Tuscaloosa Trend that continues today. Discovery and development was based on the correlation of the B sandstone to a mappable soft seismic event at a depth of 10,500 ft. The field was developed by 25 wells on 40-acre spacing. Olive has been waterflooded since 1983 and is a target for enhanced recovery using carbon dioxide. A total of 7.5 million stock tank bbl or approximately 75% of the original oil in place is estimated to be recoverable by conventional and enhanced recovery methods. The B sandstone was deposited by a northwest to southeast-flowing high-sinuosity meandering river system. Point bar, channel, and channel abandonment deposits are present. The point bar formed from the lateral migration of the river system from west to east, and channel abandonment is evident at the ...

1987-05-01

479

Approaches to Modeling Coupled Flow and Reaction in a 2-D Cementation Experiment  

Energy Technology Data Exchange (ETDEWEB)

Porosity evolution at reactive interfaces is a key process that governs the evolution and performances of many engineered systems that have important applications in earth and environmental sciences. This is the case, for example, at the interface between cement structures and clays in deep geological nuclear waste disposals. Although in a different transport regime, similar questions arise for permeable reactive barriers used for biogeochemical remediation in surface environments. The COMEDIE project aims at investigating the coupling between transport, hydrodynamics and chemistry when significant variations of porosity occur. The present work focuses on a numerical benchmark used as a design exercise for the future COMEDIE-2D experiment. The use of reactive transport simulation tools like Hytec and Crunch provides predictions of the physico-chemical evolutions that are expected during the future experiments in laboratory. Focus is given in this paper on the ...

2008-04-01

480

Use of X-ray fluorescence analysis in the study of archeological samples  

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.

1988-09-26

481

Radiostrontium in milk and tap water. Appendix D  

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.

1980-01-01

482

Pitting corrosion of steel pipeline in oil-water-gas multiphase flow system  

Energy Technology Data Exchange (ETDEWEB)

Severe pitting corrosion occurred in a horizontal steel pipeline used to transport multiphase fluid, including water, oil, and natural gas, after 2 months of service. The pitting corrosion rate was up to 42 mm/year. Chemical analysis, X-ray diffractometry, and EDAX showed that the corrosion products mainly consisted of Fe9S8, FeCO3, and NaCl. Calcium containing inclusions were also found in the matrix of the steel, which may accelerate corrosion. The early failure was attributed to the high proportion of water, the slow flow velocity, and the use of unqualified material. (Author)

2000-07-01

483

Phase diagrams  

International Nuclear Information System (INIS)

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

484

New materials for SRS lasers  

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.

2006-10-31

485

Models of cardiac electromechanics based on individual hearts imaging data  

British Library Electronic Table of Contents (United Kingdom)

Current multi-scale computational models of ventricular electromechanics describe the full process of cardiac contraction on both the micro- and macro- scales including: the depolarization of cardiac cells, the release of calcium from intracellular stores, tension generation by cardiac myofilaments, and mechanical contraction of the whole heart. Such models are used to reveal basic mechanisms of cardiac contraction as well as the mechanisms of cardiac dysfunction in disease conditions. In this paper, we present a methodology to construct finite element electromechanical models of ventricular contraction with anatomically accurate ventricular geometry based on magnetic resonance and diffusion tensor magnetic resonance imaging of the heart. The electromechanical model couples detailed repres...

2011-01-01

486

Mineral analysis in experimental corneal scars. An EDAX study  

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.

1988-01-01

487

Mechanical Properties of Carbon Nanotubes / Hydroxyapatite Composites Prepared by Spark Plasma Sintering  

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.

2006-05-05

488

Fundamental investigation of duct/ESP phenomena. Final report  

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)

1991-10-21

489

Fundamental investigation of duct/ESP phenomena  

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)

1991-10-21

490

Elemental concentration analysis in some plant samples by EDXRF at Trabzon  

International Nuclear Information System (INIS)

The elemental analysis of some plant samples have been carried out in Trabzon region (Turkey) using energy-dispersive X-ray fluorescence (EDXRF) spectrometry. We have analyzed plant samples for nine stations using 1.85 GBq 55Fe radioactive sources. We have found that potassium and calcium within 0.3-1.4% and 0.3-2.8% were present in concentration in plants for every station, respectively. The concentration of Cl and Ti generally changed according to the plant species and the sampling station.

2006-12-01

491

CaSnO3:. a high capacity anode material for Li-ion batteries  

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.

2002-12-01

492

Two Functional S100A4 Monomers Are Necessary for Regulating Nonmuscle Myosin-IIA and HCT116 Cell Invasion.  

Science.gov (United States)

S100A4, a member of the Ca(2+)-activated S100 protein family, regulates the motility and invasiveness of cancer cells. Moreover, high S100A4 expression levels correlate with poor patient survival in several cancers. Although biochemical, biophysical, and structural data indicate that S100A4 is a noncovalent dimer, it is unknown if two functional S100A4 monomers are required for the productive recognition of protein targets and the promotion of cell invasion. To address this question, we created covalently linked S100A4 dimers using a glycine rich flexible linker. The single-chain S100A4 (sc-S100A4) proteins exhibited wild-type affinities for calcium and nonmuscle myosin-IIA, retained the ability to regulate nonmuscle myosin-IIA assembly, and promoted tumor cell invasion when expressed in S100A4-deficient colon carcinoma cells. Mutation of the two calcium-binding EF-hands in one monomer, while leaving the other monomer intact, caused a ...

2011-07-13

493

Evaluation of calcification in pulmonary nodules using bone images obtained with single exposure energy subtraction  

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 ...

1995-08-01

494

Evaluation of calcification in pulmonary nodules using bone images obtained with single exposure energy subtraction  

International Nuclear Information System (INIS)

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 was ...

1995-01-01

495

Crystallographic data for new phases in the CaSO/sub 3/-H/sub 2/O system  

Energy Technology Data Exchange (ETDEWEB)

Among the three modifications of calcium sulfite hemihydrate, two of them, hexagonal ..beta..-CaSO/sub 3/.1/2H/sub 2/O with a rhombohedral lattice and ..gamma..-CaSO/sub 3/.1/2H/sub 2/O with a simple triangular hexagonal lattice, were found in the authors' recent work. By heating ..cap alpha..- and/or ..gamma..-hemihydrate at 330-360/sup 0/C in a nitrogen atmosphere, the orthorhombic anhydrate ..cap alpha..-CaSO/sub 3/ was formed, with lattice constants of 6.472, 15.93, and 23.44 angstrom for a, b, and c respectively, while the body-centered tetragonal anhydrate ..beta..-CaSO/sub 3/, with lattice constants of 15.68 and 19.44 angstrom for a and c respectively, was formed by heating the ..beta..-hemihydrate. The dehydration of three hemihydrates and the hydration of two anhydrates were discussed. Calcium sulfite hemihydrate (CaSO/sub 3/.1/2H/sub 2/O) is useful as an architectural material since it has a high thermal stability and a low ...

1982-03-01

496

Biological effects of exogenous adenosine 5 prime -triphosphate on cultured mammalian cells: Evidence for a receptor mechanism and its regulation by desensitization  

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. ...

1989-01-01

497

Surface modification, organometallic and polyaryl polymer coatings, and flame spray technologies for preventing corrosion of metals. Final report  

Energy Technology Data Exchange (ETDEWEB)

To improve adherent properties of electrogalvanized steel (EGS) to polymeric topcoats, the surfaces of EGS were modified by polyelectrolyte-modified zinc phosphating solution. The electrochemical reaction between phosphating solution and EGS led to the complete coverage with fully grown hopeite crystals after only 5 sec treatment, thereby improving adhesion to topcoating and providing protection of EGS against corrosion. To evaluate the ability of polyphenylene sulfide (PPS) polyaryl thermoplastic coatings to protect zinc phosphate (Zn{center_dot}Ph)treated steels from corrosion in a wet, harsh environment ( 1.0 wt % H{sub 2}SO{sub 4}, 3.0 wt % NaCl and 96.0 wt % water at temperatures from 25{degrees} to 200{degree}C), we exposed them in an autoclave to attempt heating-cooling cyclic fatigue tests (1 cycle = 12 hr at 200{degrees}C + 12 hr at 25{degrees}C) up to 90 times. The major chemical reaction at the interface between ...

1995-07-01

498

Immobilization of tetravalent actinides in three phosphate based ceramics: britholites, TPD and monazites/brabantites  

Energy Technology Data Exchange (ETDEWEB)

Three phosphate based ceramics were studied for the immobilization of tri- and tetravalent actinides: britholites Ca{sub 9}Nd{sub 1-x}An{sub x} {sup IV}(PO{sub 4}){sub 5-x}(SiO{sub 4}){sub 1+x}F{sub 2}, monazites/brabantites Ln{sub 1-2x}{sup III}Ca{sub x}An{sub x}{sup IV}PO{sub 4} and Thorium Phosphate Diphosphate (TPD) Th{sub 4-x}An{sub x}{sup IV}(PO{sub 4}){sub 4}P{sub 2}O{sub 7}. For each material, the incorporation of Th, U(IV), or Ce(IV) in the structure was examined. This work was the early beginning of the incorporation of {sup 239}Pu and/or {sup 238}Pu in order to evaluate the effects of {alpha} -decay on these three crystallographic structures. The syntheses were carried out using dry chemistry methods, involving mechanical grinding then heating treatment (1100 deg C {<=} {theta} {<=} 1400 deg C). For britholites, we showed that the incorporation of thorium was complete for weight loading lower than 20 wt.% through the ...

2004-07-01

499

Study of coastal water zone ecosystem health in Zhejiang Province based on remote sensing data and GIS  

British Library Electronic Table of Contents (United Kingdom)

The coastal ecosystem health assessment is a field of increasing importance. In this paper, a preliminary assessment of ecosystem health in Zhejiang coastal water zone was made, mainly based on remote sensing data and GIS technique. Its spatial and quantitative evaluation was facilitated by the progress of remote sensing and GIS technique development. Firstly, human activities, hydrology and ecosystem problems in the study area were discussed and analyzed. Secondly, from 4 aspects of human stress, physical, chemical and biological responses to anthropogenic activities and natural stress, several indicators such as water transparency (Secchi Disk Depth, SDD), suspended substance concentration, dissolved inorganic nitrogen, active phosphate, chlorophyll, harmful algae bloom, as well as distr...

2010-01-01

500

Polymeric nanosponges as an alternative carrier for improved retention of econazole nitrate onto the skin through topical hydrogel formulation  

British Library Electronic Table of Contents (United Kingdom)

The present study was carried out to exploit the feasibility of using polymeric nanosponges as an alternative carrier for targeting econazole nitrate (EN) to the skin through topical hydrogel formulation. Nanosponges prepared by emulsion solvent diffusion method were evaluated for various physicochemical parameters and in vitro drug release. The nanosponges of EN were discrete free flowing nanosized particles with perforated orange peel like morphology as visualized by SEM. The nanosponge formulated using PVA:EC (3:2) displayed highest in vitro release after 12 ?h in phosphate buffer (pH 6.8) that fitted matrix model. Selected nanosponge was formulated as Carbopol 934 NF hydrogel using varying concentrations of permeation enhancers propylene glycol and N-methyl-2-pyrrolidone. The EN nanosp...

2011-01-01