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.

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.)

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 ...

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...

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 ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared

Science.gov (United States)

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

International Nuclear Information System (INIS)

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

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 ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

KoreaScience (Korea)

Full Text Available

UK PubMed Central (United Kingdom)

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

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

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

KoreaScience (Korea)

Full Text Available

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 ...

Wastenet

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

Wastenet

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

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

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

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 ...

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

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 ...

Energy Technology Data Exchange (ETDEWEB)

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

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

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)

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.

Wastenet

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

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.

KoreaScience (Korea)

Full Text Available

International Nuclear Information System (INIS)

Russian (1972). USSR Desyatnik, VN Kurbatov, NN Raspopin, SP Trifonov,

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

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)

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 ...

Energy Technology Data Exchange (ETDEWEB)

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

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...

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 ...

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

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

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 ...

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

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

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

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, ...

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. ...

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.

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 + ...

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 ...

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

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.

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

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

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.

International Nuclear Information System (INIS)

Russian 2008 p. 27-29 Russian Federation Belanova, EA Kozlov, PV FGUP

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 ...

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 ...

Energy Technology Data Exchange (ETDEWEB)

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

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

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

UK PubMed Central (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

British Library Electronic Table of Contents (United Kingdom)

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

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 ...

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.

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.

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 occurred during one ...

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 ...

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

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

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

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

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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 ...

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...

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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.

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...

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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.

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...

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...

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

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

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

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

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 ...

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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 ...

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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 ...

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 ...

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

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

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.

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

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...

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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.

International Nuclear Information System (INIS)

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

Science.gov (United States)

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

Science.gov (United States)

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

Science.gov (United States)

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

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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 ...

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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 ...

International Nuclear Information System (INIS)

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

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.

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

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

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 ...

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...

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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).

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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.

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...

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 ...

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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 secondary quartz ...

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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 ...

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 ...

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

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

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 ...

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

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

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.

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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 ...

Energy Technology Data Exchange (ETDEWEB)

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

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

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

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.).

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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 ...

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.

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 ...

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

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

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.

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.

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

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.

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 ...

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.

International Nuclear Information System (INIS)

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

Science.gov (United States)

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

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.).

International Nuclear Information System (INIS)

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

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 ...

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 ...

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.).

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).

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.

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...

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.)

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 ...

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.

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 ...

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 ...

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.

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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)

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

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...

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.

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.

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.

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

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...

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...

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.

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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.

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

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.

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 ...

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

British Library Electronic Table of Contents (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

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

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 ...

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

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.

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

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

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 ...