Juvenile trees of kalmia derived from shoot tip culture, and seedlings of kobus were irradiated with #gamma#-rays. In kalmia, two mutation lines were obtained which had narrowlong leaves. In kobus two mutation lines were obtained. One mutation line has flowers with 7 to 13 petals. Another mutation line has yellow-green variegated leaves. (author).
The water culture experiment of Houttuynia cordata of the medicinal plant was carried out, and basic study on {sup 137}Cs accumulation characteristic and internal circulation in H. cordata in the fruiting stage was investigated since the flowering season. H. cordata accumulated 80% of {sup 137}Cs absorbed unlike K to the root, rhizome, terminal bud of the underground part for the rhizome reproduction. {sup 137}Cs content to the young leaf, spike, involucre increased in the flowering season. Thereafter, {sup 137}Cs was recirculated to the developing organs in second generations such as the rhizome and bud. (author)
In this study, the essential oil from lotus flower extract, including petals and stamens, was assessed with regard to its effects on melanogenesis in human melanocytes. The lotus flower essential oil...Full Text Available
Higher plants use photoperiodic cues to regulate many aspects of development, including the transition from vegetative to floral development. The EARLY FLOWERING3 (ELF3)...Full Text Available
Explants from flower stalks of Nicotiana tabacum L. were cultured on different cytokinins to induce flower bud formation. All cytokinins tested except zeatin and zeatin-riboside induced...Full Text Available
A field experiment was conducted during the summer of 1988 to test the hypothesis that water deficit affects the abscisic acid (ABA) and indole acetic acid (IAA) concentrations in cotton (Gossypium...Full Text Available
External application of auxin and cytokinin is required for the formation of flower buds on thin-layer tissue explants of Nicotiana tabacum cv Samsun. Interaction between both plant...Full Text Available
The competence of pedicel explants of tobacco (Nicotiana tabacum L. cv Samsun) to regenerate flower buds in response to auxin was manipulated by preincubating excised tissues in the...Full Text Available
For identification of genes responsible for varietal differences in flowering time and leaf morphological traits, we constructed a linkage map of Brassica rapa DNA markers including...Full Text Available
The effect of mean daily air temperature (MDT) on flowering rate (the reciprocal of days to flower) was quantified for 18 species of annual bedding plants. Plants were grown in environmental growth chambers at constant air temperature set points of 5, 7.5, 10, 15, 25, or 30^oC and under an irradiance of 160-180mmolm^-^2s^-^1, with a 16-h photoperiod. Nonlinear mathematical equations were developed to predict the effect of MDT on flowering rate and to estimate the base, optimum, and maximum temperatures (Tmin, Topt, and Tmax), which are the temperatures at which flowering rates are zero (low temperature), maximal, and zero once again (high temperature), respectively. The estimated Tmin varied among species and ranged from 1.1^oC in French marigold (Tagetes patula L.) to 9.9^oC in angelonia ...
A study was undertaken to assess the effect of different storage temperatures on senescence and postharvest performance of isolated flowers of Ranunculus asiaticus L.. The main aim of the work was to develop a cost-effective storage protocol to reduce the postharvest losses and to bring out the transportation of cut flowers of R. Asiaticus. The flowers were subjected to two different storage treatments, dry storage and wet storage, and their postharvest performance was compared under laboratory conditions. For this purpose, the buds were harvested at 8:00 AM at loose bud stage (Stage II of flower development). The harvested buds were cut to a uniform size of 15 cm and processed for dry or wet storage. For dry storage, the buds were packed after wrapping them in moistened filter papers and ...
As a new production technique of yellow cake, resorption with loaded resin-elution with acid ammonium nitrate-precipitation in two steps is studied. The results show that the produced yellow cake by the new production technique has better performance of settlement, filtration and dehydration. Each index of yellow cake accords with the first grade level issued by CNNC without washing, uranium and water content are 70% and 25%, respectively
BackgroundCo-flowering plant species frequently share pollinators. Pollinator sharing is often detrimental to one or more of these species, leading to competition for pollination....Full Text Available
BackgroundSenescence is integral to the flowering plant life-cycle. Senescence-like processes occur also in non-angiosperm land plants, algae and photosynthetic prokaryotes. Increasing...Full Text Available
This document gathers a series of very short articles concerning nuclear industry around the world. Areva company is investing 30 million euros in its Chalon-Saint-Marcel plant, it is the consequence of the extension of service life of nuclear power plants in the Usa. Areva holds 40% of the American market concerning the replacement of steam generators and 50% of that concerning the replacement of closure heads. The Obrigheim nuclear power plant was definitely closed down on may 2004, this decommissioning is a step forward in the German policy of progressively stepping out of nuclear energy. Chinese authorities are willing to construct 40 nuclear reactors in 15 years, despite that, the contribution of nuclear energy to the generation of electricity will reach only 4% in 2020. In 2007 Cea will begin the construction works of a new research reactor (Jules Horowitz reactor) in the Cadarache site. Prices of the yellow cake have ...
Previous studies with a limited number of strains have indicated that there are two genotypes of yellow fever (YF) virus in Africa, one in west Africa and the other in east and central Africa. We have...Full Text Available
Supercoiled double-stranded DNA molecules (plasmids) were isolated from plants infected with three laboratory strains of western aster yellows mycoplasma-like organism (AY-MLO) by using cesium chloride-ethidium...Full Text Available
AbstractX-ray diffraction analysis of pressure-induced structural changes in the Aequorea yellow fluorescent protein Citrine reveals the structural basis for the continuous...Full Text Available
Several independent studies of bacterial degradation of nitrate ester explosives have demonstrated the involvement of flavin-dependent oxidoreductases related to the old yellow enzyme (OYE) of yeast....Full Text Available
The author presents a new technique for production of yellow cake with double precipitation, thus solving a series of problems for precipitating uranium with traditional double precipitation. The new technique can not only remove ferric ions and sulfate radicals but also make solid-liquid separation easy, utilize effectively the sulfuric acid produced in ferric ions precipitation process, and increase uranium concentration of leaching liquor. To take it as producing yellow cake will save investment, simplify operation, and cut down the consumption of raw materials and energies. It is more competitive than ion-exchange or solvent extraction in the process of extracting-purifying and preparing yellow cake.
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)
Sugarcane yellow leaf caused by Sugarcane yellow leaf virus (ScYLV) does not produce visual symptoms in most susceptible plants until late in the growing season. An experiment was conducted to determine if leaf reflectance and pigment analysis could be used to determine ScYLV infection prior to sym...
Sorghum is a good candidate crop for breeding to increase provitamin A, i.e., biofortification. Yellow endosperm sorghums contain carotenoids, including precursors of vitamin A, and sorghum is a major staple crop in areas of Asia and Africa where vitamin A deficiency is prevalent. Our objective was to collect and characterize yellow endosperm sorghums as a potential new source of genetic diversity to increase provitamin A content. A set of 164 landraces were collected from southern Niger and northern Nigeria. The most important use of these cultivars was as food. The endosperm exhibited a significant variation in yellow intensity. Lutein, zeaxanthin and ?-carotene were the most abundant carotenoids in the ten landraces with the most intense yellow color. Cluster analysis, principal coordin...
The Korea Atomic Energy Research Institute has launched a decommissioning program of uranium conversion plant. One of the important tasks in the decommissioning program is the treatment of the sludge, which was generated during operation and stored in the two ponds of the lagoon. The treatment requires the volume reduction of lagoon sludges for the low cost of the program and the conversion of the chemical forms, including uranium, for the acceptance at the final disposal site. The physical properties, such as densities, were measured and chemical compositions and radiological properties were analyzed. The denitration was a candidate process which would satisfy the requirements for sludge treatment, and the characteristics of thermal decomposition and dissolution with water were analyzed. The main compounds of the sludge were ammonium and sodium nitrate from conversion plant and calcium nitrate, calcium carbonate from Ca precipitation and impurities of the ...
During reproduction in flowering plants, pollen grains form a tube that grows in a polarized fashion through the female tissues to eventually fertilize the egg cell. These highly polarized pollen tubes...Full Text Available
Depending on the species, the end of flower life span is characterized by petal wilting or by abscission of petals that are still fully turgid. Wilting at the end of petal life is due to programmed...Full Text Available
Polyploidy is an important force in the evolution of flowering plants. Genomic merger and doubling induce an extensive array of genomic effects, including immediate and long-term alterations in the...Full Text Available
The aromas of fruits, vegetables, and flowers are mixtures of volatile metabolites, often present in parts per billion levels or less. We show here that tomato (Lycopersicon esculentum...Full Text Available
BackgroundOncidium spp. produce commercially important orchid cut flowers. However, they are amenable to intergeneric and inter-specific crossing making phylogenetic...Full Text Available
Arabidopsis thaliana SUPERMAN (SUP) plays an important role during flower development by maintaining the boundary between stamens and carpels in the inner two whorls....Full Text Available
Experiments were conducted to investigate indole-3-acetic acid (IAA) and abscisic acid (ABA) metabolism associated with postanthesis senescence of ovaries from nonpollinated muskmelon (Cucumis...Full Text Available
FLOWER, a computer code recommended by USNRC for assessing the environmental impact in tidal regions, was adapted and improved so as to be suitable to deal with the influence of drift stream along seashore to the dilution of contaminants and heat in the bay mouth. And the code outputs were presented with more mid-results such as average concentrations and temperature values for all tides considered. Finally, the modified code is applied to the dispersion calculation of heat and liquid effluents from Daya Bay Nuclear Power Plant, and the impacts from routine operation of the plant on Daya Bay sea waters were given.
Forty synthetic food colors were determined in drinks and candies by reversed-phase high-performance liquid chromatography with photodiode array detection. The following food colors were analyzed within 19min using a short analytical column (50mmx4.6mm i.d., 1.8mm) at 50degreeC with gradient elution: Ponceau 6R, Tartrazine, Fast yellow AB, Amaranth, Indigotine, Naphthol yellow S, Chrysoine, Ponceau 4R, Sunset yellow FCF, Red 10B, Orange G, Acid violet 7, Brilliant black PN, Allura red AC, Yellow 2G, Red 2G, Uranine, Fast red E, Green S, Ponceau 2R, Azorubine, Orange I, Quinoline yellow, Martius yellow, Ponceau SX, Ponceau 3R, Fast green FCF, Eosine, Brilliant blue FCF, Orange II, Orange RN, Acid blue 1, Erythrosine, Amido black 10B, Acid red 52, Patent blue V, Acid green 9, Phloxine B, Ben...
... has confirmed at least one instance of this: in 2005, Tanzanian customs officials intercepted a shipment that contained a yellow cake-filled barrel ...
... shrouded in secrecy in 2008, Iraq sold its stock of 550 metric tons (in 3,500 barrels) of apparently commercial-grade yellow cake (milled uranium ...
... The MTT assay indicates cell viability through a yellow to purple ... besiegers were said to have catapulted plague infected corpses into the city of ...
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A Process for yellow cake production from local Euxenite was developed in Bench Scale by using sulphuric acid digestion with simultaneously ion-exchange and solvent extraction purification steps. Uranium was then precipitated as uranium diuranate by ammonia solution. Equipment used in this process includes : digestion vessels, columnar ion-exchange, solvent extraction and precipitation units Ore feed to the process could be adjusted up to 2 kilogram per day (8 hours operation) with yellow cake product purity meet the requirement of Usaec standard of about 10-50 gram per day. Included in this experiment are the leaching characteristics of the ore, the design and construction of continuous columnar 4-cycle ion exchange unit, determination of the extraction and stripping stages of a gravity flow mixer-settler and the design and construction of continuous yellow cake precipitation unit with large grain size and high density ...
The sediment content of the Yellow River is resulted from the interactions of natural, economic, and social factors, so it includes some evolutive information of the Yellow River Basin system. Sediment contents from 1952 to 2007 on Toudaoguai, Tongguan, Huayuankou and Lijin sections along the river are chosen as the study time series, and correlation dimensions (D 2), Kolmogorov entropies (K 2), and Hurst indexes (H) of the time series were calculated. Correlation dimensions on Toudaoguai, Tongguan, Huayuankou, and Lijin sections are 3.24, 5.69, 6.57 and 7.34 respectively, and the Kolmogorov entropies are 0.13, 0.37, 0.40 and 0.38 respectively, which indicates that the systems controlled by different sections along the Yellow River are chaotic systems and the chaotic degrees increase gradu...
Sesame varieties/genotypes showed a good response to radiation with gamma rays and treatments with EMS. In M_1 both gamma rays and EMS influenced germination, seedling height, survival of plants and pollen fertility/sterility, producing deleterious effects on these characters. Compared to black seeded genotypes, white seeded ones are more susceptible to radiation. Both gamma rays and EMS produced various types of morphological variations in M_2 generation. These were dwarf plant mutants, mottled and fleshy leaved mutants (sterile), fasciated stem, flower colour, altered phyllotaxy, early, uniculm, capsule size variations, multiple capsule/leaf axil, seed coat colour variations, indehiscent and semi-indehiscent type mutants. Moreover, studies on quantitative characters including seed yield revealed the induction of mutants in both positive and negative directions for such traits which made a good scope of selection of desirable mutants in M_2 ...
This paper reviews the mill flowsheet applied at the SOMAIR (Societe des Mines de l'Air) uranium mill in Niger. It focuses on the yellow cake quality improvements achieved by molybdenum and zirconium elimination through double yellow cake precipitation in tanks at first stage and through size/density control in a fluidized bed precipitator at second stage. Water saving aspects in the plant are also presented. (author)
This study was carried out mainly to produce uranium trioxide (UO_3), with the standard of commercial specifications from rock phosphate deposits in eastern part of Nuba mountains, south Kurdufan state. A simplified hydrometallurgical procedure has been adopted for production of yellow cake from the ore. Elemental analysis has shown that the ore is rich in Ca and deficient in elements of potential interest such as Fe, Cu and Zn. Uranium content in ore, phosphoric acid and purified yellow cake (UO_3) obtained with different precipitants was analyzed using alpha-spectrometry. On the average, the activity concentration of uranium in ore corresponds to 82 #+-# 24 ppm (0.10%). From the data of pregnant liquor, it was observed that the addition of KCIO_3 as an oxidant improves the dissolution of uranium from the ore by almost 20%. Data has also indicated that the yellow cake purified by hydrogen peroxide has higher concentration ...
...com: Directory Enquiries International Dialing Codes International Telephone Directory White and Yellow Pages Europe WhoWhere? Yell: Electronic Yellow Pages Comments: bubl@...6 Resource type: directory International Dialing Codes Table listing country codes (for makes telephone calls to that country) and IDD (International ...Direct Dialing) prefixes (for dialing abroad from that country). Author: Kropla, Steve ...
The Yellow Fever Vaccine 17D (YFV17D) has been used as a vector for the Lassa virus glycoprotein precursor (LASV-GPC) resulting in construction of YFV17D/LASV-GPC recombinant virus. The virus...Full Text Available
Abstract Although photosynthetic thermotolerance has been investigated extensively in cotton leaves, reports on the biochemical influence of the pistil in promoting fertilization thermostability are limited. To evaluate the effect of temperature, genotype, and exogenous calcium application on fertilization and pistil biochemistry in cotton, thermosensitive (cv. ST4554 B2RF) and thermotolerant (cv. VH260) plants were grown under control (30/20-C) or high-temperature (38/20-C) conditions during flowering, and exogenous CaCl2 was applied to flowers 1-day prior to anthesis. Measured pistil parameters included fertilization efficiency; protein concentration; glutathione reductase, superoxide dismutase (SOD) and NADPH oxidase activities; and ATP and calcium levels. Exogenous calcium had no effec...
This study was carried out mainly to produce uranium trioxide (UO_3), matching standard commercial specification from rock phosphate deposits in Uro and Kurun at eastern part of the Nuba Mountains. A simplified hydrometallurgical procedure has been adopted for production of yellow cake from the ore. The powdered ore sample was leached with concentrated H_2SO_4 acid with and without addition of KCIO_3 as an oxidant. The crude yellow cake was precipitated from the resulting green solution of phosphoric acid as Na_2U_2O_7 and (NH_4)_2U_2O_7 and subsequently purified by TBP extraction (tributylphosphate) and hydrogen peroxide as UO_4.2H_2O. TBP purified product was dried and calcined to UO_3 whereas UO_4.2H-2O was dried and reduced to UO_3 by Na_2S_2O_3. Prior to precipitation of crude yellow cake, Fe in the phosphoric acid solution was precipitated using magnesia. Elemental analysis has shown that the ore is rich in Ca and ...
In order to reduce the total number of experiments for achieving the highest removal of methylene blue (MB) from aqueous solutions using yellow passion fruit peel (Passiflora edullis, F. flavicarpa) and mandarin peel (Citrus reticulata) as biosorbents two independent sets of full 23 factorial designs with two central points (10 experiments) were experimented. In order to continue the optimization of the system a new full 22 factorial design with two central points (six experiments) and a central composite surface analysis (13 experiments, divided into four cube points, five centre points, and four axial points) were employed for yellow passion fruit peel (PFP) and mandarin peel (MP), respectively. Using these statistical tools, the best conditions for MB removal from aqueous solution were ...
The removal of color from aquatic systems caused by presence of synthetic dyes is extremely important from the environmental viewpoint because most of these dyes are toxic, mutagenic and carcinogenic. In this present study, the yellow passion fruit (Passiflora edulis Sims. f. flavicarpa Degener) peel a powdered solid waste, was tested as an alternative low-cost adsorbent for the removal of a basic dye, methylene blue (MB), from aqueous solutions. Adsorption of MB onto this natural adsorbent was studied by batch adsorption isotherms at room temperature. The effects of shaking time and pH on adsorption capacity were studied. An alkaline pH was favorable for the adsorption of MB. The contact time required to obtain the maximum adsorption was 56h at 25degreeC. Yellow passion fruit peel may be ...
Functional properties of commercial and membrane processed pea protein isolates (PPI) prepared from yellow peas were investigated. Four protein isolates were prepared from yellow pea flour using water and KCl extractions at 25^oC followed by ultrafiltration and diafiltration (UF and DF) at pHs of 7.5 and 7.5 or 6 respectively. Following assessment of compositional attributes; solubility, foaming, flow and dynamic rheology, emulsification ability and heat-induced textural and rheological properties of prepared PPIs and a commercially available PPI were tested and compared. Membrane purification of proteins resulted in 28% to 68% reduction in phytic acid and enhanced, comparatively, the tested functional properties. Solubility of membrane processed PPIs, at all tested pHs, was superior and t...
DescriptionM291272: Annex A: Project specification Introduction Lowland grassland habitats host a wide range of rare, scarce and declining flowering plants, some of which are afforded protection under UK and EU legislation, as well as qualifying for Red Data lists and Biodiversity Action Plan priority lists. Other scarce species while not qualifying for the above designations are still of conservation significance and should help inform our priorities for lowland grassland habitat management. At prese [continued...
It may be necessary to reduce microbiological contamination of crude drugs (medicinal plants or their parts like roots, leaves, flowers). This can be done by treating the drugs with ionizing radiation. Meethods for detection of such an irradiation were developed. It could be pointed out that measurements of luminescence, viscosity and electron spin resonance were suitable for specific drugs, but not for all drugs. (orig.).
Tomato (Lycopersicon esculentum var. Better Boy) plants were transformed with a tomato leaf wound-inducible polygalacturonase (PG) β-subunit gene in the antisense orientation...Full Text Available
The present study was carried out during two successive seasons of 2005 and 2006 seasons on"Montakhab El-Kanater"guavas and"Hachiya"persimmons.two different experiments were studied, the first one for pre harvest and second post harvest. Regarding pre harvest experiment,hand or chemical flower thinning by urea or ethrel and date of fruit picking (maturity) were evaluated on both guavas and persimmons.All flower thinning treatments increased fruit set,total yield,average fruit weight and decreased fruit abscission.However,a great effect on fruit quality and chemical compositions were also found with flower thinning treatments. Chemical flower thinning was more effective than hand thinning in improving yield and quality in "Montakhab El-Kanater"guavas and "Hachiya"persimmons. However,early maturation(120 and 150 days for guava and persimmon respect.) produced poor fruit quality.Whereas, medium ...
Studies of flower development in core eudicot species have established a central role for B class MADS-box genes in specifying petal and stamen identities. Similarly in maize and rice, B class genes...Full Text Available
A yellow-pigmented, gram-negative, gliding bacterium isolated from an industrial water spray air humidification system was implicated as a causative agent in several occurrences of lung disease with...Full Text Available
Begomoviruses are phytopathogens that threaten food security [18]. Sida spp. are ubiquitous weed species found in Jamaica. Sida samples were collected island-wide, DNA was extracted via a modified Dellaporta method, and the viral genome was amplified using degenerate and sequence-specific primers [2, 11]. The amplicons were cloned and sequenced. Sequence analysis revealed that a DNA-A molecule isolated from a plant in Liguanea, St. Andrew, was 90.9% similar to Sida golden yellow vein virus-[United States of America:Homestead:A11], making it a strain of SiGYVV. It was named Sida golden yellow vein virus-[Jamaica:Liguanea 2:2008] (SiGYVV-[JM:Lig2:08]). The cognate DNA-B, previously unreported, was successfully cloned and was most similar to that of Malvastrum yellow mosaic Jamaica virus (MaYMJV). Phylogenetic analysis suggested that this virus was most closely related to begomoviruses that infect malvaceous hosts in Jamaica, ...
Whereas genetic factors are known to influence both susceptibility to carcinogens and the capacity to respond to specific antigenic stimuli, little is known regarding the influence of phenotype per...Full Text Available
The objective of this study was to develop a specific immunological diagnostic assay for yellow disease in hyacinths, using monoclonal antibodies (MAbs). Mice were immunized with a crude cell wall preparation...Full Text Available
Computer-assisted analysis revealed a striking sequence similarity between the putative 24-kDa protein (p24) encoded by open reading frame (ORF) 5 of beet yellows closterovirus and the coat protein...Full Text Available
A sensitive and specific detection method was developed for Xanthomonas hyacinthi; this method was based on amplification of a subsequence of the type IV fimbrial-subunit gene fimA...Full Text Available
Purified cell walls were prepared from roots of Horse bean (Vicia faba L., var. minor) and Yellow Lupine (Lupinus luteus L.). Two methods were used:...Full Text Available
We have isolated a genomic clone containing 'Lupinus luteus' 5S ribosomal RNA genes by screening with 5S rDNA probe clones that were hybridized previously with the initiator methionine tRNA preparation (contaminated) with traces of rRNA or its degradation products). The clone isolated contains ten repeat units of 342 bp with 119 bp fragment showing 100% homology to the 5S rRNA from yellow lupine. Sequence analysis indicates only point heterogeneities among the flanking regions of the genes. (author). 6 refs, 3 figs.
Recovery of uranium by ion-exchange processes from impure acid leach liquors is described, which produce a concentrated and pure eluate employing 10% sulphuric acid elution. In situations where resin is loaded to 45 g/ltr or more the acid consumption at ambient temperature is less than 4 kg of H_2SO_4 per kilogram of U_3O_8. Precipitation with an alkali such as ammonia or magnesia produces a yellow cake of high purity. (author).
Elemental substitution of Ca by Y was investigated for Ca-#alpha#-SiAlON:Eu yellow phosphors, which is useful for the white light-emitting diode lamps of phosphor conversion type. Depending on the ratio of the elemental substitution, not only the red shift of emission in wavelength occurred but also the figure of the excitation spectra changed. Their excitation band widths and flatness were discussed. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
Continuous wave lasing operation with the shortest wavelength for semiconductor lasers was obtained from AlGaInP double heterostructure lasers at 77 K. The structure was grown by metalorganic vapor phase epitaxy. Lasing wavelength was 583.6 nm (yellow). Threshold current was 43 mA (1.9 kA/cm/sup 2/). Magnesium was adopted as a p-type dopant, and was proved to be preferable for a high aluminum composition AlGaInP cladding layer.
Full text: Dissolution test (DT) is one of the important specifications of PFBR MOX fuel. It is a macro homogeneity test used to ascertain that the dissolution of spent fuel will be easier during reprocessing. The DT specification limit for PFBR MOX fuel is ? 1.0 wt.% residue of the whole pellet when it is dissolved in HNO3 under reflux conditions. For this test, sintered MOX pellet is dissolved in reflux condition in 60 ml of 12M HNO3 for 10 hours. This test is carried out for each batch and during complete MOX campaign a lot of MOX waste in liquid form is being generated. This liquid waste is in clean form and U and Pu is required to be recovered from the clean waste. Different methods like direct denitration, precipitation and solvent extraction are available but either the product is not of good quality for pelletization or secondary liquid wastes are generated. Microwave denitration is a faster and cleaner method which has different heat ...
Typically, plant-pollinator interactions are recognized as mutualistic relationships. Flower visitors, however, can potentially play multiple roles. The floral nectar in Croton suberosus has been proposed to operate as a reward for predators, especially the wasp Polistes instabilis (Vespidae), which kills herbivorous insects, while the plant has been thought to be mainly wind-pollinated. In this study, we reassessed the pollination mode of C. suberosus and the possible role of its flower visitors. Pollinator exclusion experiments demonstrated that C. suberosus should be considered a strictly entomophilous species. Inflorescences of C. suberosus were visited by a diverse entomofauna involving 28 taxa belonging to six orders; however, wasps and bees were the only visitors that carried C. suberosus pollen. The visitation rate of wasps was approximately four times that of bees. This observation, combined with the fact that the small size of bees ...
Pilot industrial-scale testing of TSK-25 and TSK-10 compounds produced by NPP Tekhmet has been performed at Ruspolimet for siphon casting of 0.7?1.5-metric-ton ingots which are broader on the top (?flowers??) used for production of all-rolled rings; this is as an alternative to the existing process of pouring the steel into molds lubricated with petrolatum. The evaluation tests led to recommendation of the TSK-10 compound for industrial-scale testing; use of this compound enabled the petrolatum-lubricated steel casting process to be abandoned, thereby improving working conditions, and reducing rejects of the all-rolled ring products.
DescriptionOrchids belong to the family Orchidaceae which, with around 20,000 species, is the largest in the Plant Kingdom. Orchids hold a particular fascination because of their spectacular flowers and the rarity of many species- which has increased in recent years as a result of plant collecting, intensification of agriculture and land use changes have placed many species in jeopardy. One feature of orchids that distinguishes them from many other plants is that their seeds are so reduced in size that th [continued...
This paper describes the development and a detailed analysis carried out on the luminescence characteristics of Pr"3"+ doped ZrF_4-BaF_2-LaF_3-YF_3-AlF_3-NaF glasses. In the present work our objectives are to elucidate the possible mechanisms that are responsible for NIR to red upconversion process and yellow to blue upconversion emission in terms of energy level schemes from the praseodymium containing fibre optical glass composition. We have studied their different physical and optical properties. Besides our investigation on the upconversion emission of these glasses, normal fluorescence studies have also been undertaken in explaining the mechanisms in demonstrating bright red and blue emissions upon excitations at visible and UV wavelengths. Besides these measurements works, a bright blue colour emission was observed under an UV source (202 nm) and upconverted prominent red emissions were observed with a laser diode (LD of 980 nm). Similarly under a ...
Lethal yellow (A{sup y}) is a mutation at the mouse agouti locus in chromosome 2 that causes a number of dominant pleiotropic effects, including a completely yellow coat color, obesity, an insulin-resistant type II diabetic condition, and an increased propensity to develop a variety of spontaneous and induced tumors. Additionally, homozygosity for A{sup y} results in preimplantation lethality, which terminates development by the blastocyst stage. The A{sup y} mutation is the result of a 170-kb deletion that removes all but the promoter and noncoding first exon of another gene called Raly, which lies in the same transcriptional orientation as agouti and maps 280 kb proximal to the 3{prime} end of the agouti gene. The authors present a model for the structure of the A{sub y} allele that can explain the dominant pleiotropic effects associated with this mutation, as well as the recessive lethality, which is unrelated to the agouti gene.
The yellow Iranian scorpion Odontobuthus doriae can cause fatal envenoming, but its mechanism of action is unclear. One of the reported manifestations of envenoming is moderate to severe involuntary tremor of skeletal muscle. In order to understand better the mechanism of action of this venom on skeletal muscle function, we examined the effects of the venom in vitro on chick biventer cervicis (CBC) and mouse hemidiaphragm (MHD) nerve muscle preparations. O. doriae venom (0.3-10mg/ml) initially increased and then decreased twitch height. The venom also caused contracture in both preparations. In mouse triangularis sterni preparations, used for all intracellular recording techniques, the venom enhanced the release of acetylcholine and induced repetitive firing of nerve action potentials and ...
Abstract In this study, surfactant-modified zeolite (SMZ) was used to remove Remazol Brillant Blue R and Remazol Yellow reactive dyes from aqueous solutions. The influences of suspension pH, temperature, agitation rate, and the SMZ dosage on reactive dyes removal and adsorption capacity were investigated by conducting a series of batch adsorption experiments. The adsorption kinetics was tested for pseudo-first-order, pseudo-second order, intraparticle diffusion model, Elovich, and Bangham models, and rate constants of the kinetic models were calculated. Equilibrium isotherms for the adsorption of reactive dyes were analyzed by the Freundlich, Langmuir, Dubinin-Radushkevich, and Tempkin isotherm models. The Langmuir monolayer adsorption capacities of Remazol Brillant Blue R and Remazol Yell...
This study started with a comprehensive and critical review of the published information of relevance to the different methods to produce uranium dioxide from raw materials. we have chosen this method 'flame denitration' or flame process to produce Uo_2. from its compounds, uranyl nitrate Uo_2 ( NO_3) _2 .6H_2o) prepared from raw uranium 'yellow cake'. This method in short produces uranium dioxide from aqueous uranyl nitrate by contacting the atomized liquid which has 40 #mu# in diameter with hot reducing gases (butane and oxygen mixture) till we obtain a suitable and yellow red colour light for the flame and this is a prof that there is carbon monoxide and hydrogen, the temperature of the reactor at is least 950 degree C.
Abstract Plant metabolomics has been well established and applied across multiple fields including medicine, biotechnology, and environmental sciences in the post-genomic era. The Chenopodiaceae C3 halophyte Suaeda salsa is the most important plant species in the vegetation of saline soil and even intertidal zone in the Yellow River Delta, which is economically consumed as food, widely used as a bioindicator of environmental stresses (salinity, drought, and pollution) and typically applied for the phyto-remediation of degraded wetland. However, no global studies have been focused on the metabolic profile of this halophyte which is widely applied in environment related research areas. In metabolomics, the first crucial step is the preparation of plant samples. In this work, several strategi...
Lead is contained as trace element in uranium ores and propagates throughout the production process to intermediate products like yellow cake or uranium oxide. The lead isotopes in such material originate from two sources: natural lead and radiogenic lead. The variability of the isotopic composition of lead in ores and yellow cakes was studied and the applicability of this parameter for nuclear forensic investigations was investigated. Furthermore, the chemical impurities contained in these materials were measured in order to identify characteristic differences between materials from different mines. For the samples investigated, it could be shown, that the lead isotopic composition varies largely from mine to mine and it may be used as one of the parameters to distinguish between materials of different origins. Some of the chemical impurities show a similar pattern and support the conclusions drawn from the lead isotope data. (orig.)
The effects of O and C ion implantation with different implantation doses on the yellow luminescence (YL) from unintentional doped n-type GaN have been studied by the photoluminescence (PL) spectra. O and C ions were implanted in the GaN samples with different doses from 1.0 x l013 to 1.0 x l017cm-2. Post-annealing was done in a quartz open-tube furnace under flowing N2 gas for 30 min at 950 degree C. By comparing with N ion implanted samples, it is assumed that different deep-level centers involving in the YL were produced in GaN after O and C ion implantation. In addition, with a dose of 1017 cm-2, the concentration of deep C centers involving in the YL was enhanced markedly. (authors)
Our long-term goal is to enable highly productive plant species to extract, resist, detoxify, and/or sequester toxic heavy metal pollutants as an environmentally friendly alternative to physical remediation methods. We have focused this phytoremediation research on soil and water-borne ionic and methylmercury. Mercury pollution is a serious world-wide problem affecting the health of human and wild-life populations. Methylmercury, produced by native bacteria at mercury-contaminated wetland sites, is a particularly serious problem due to its extreme toxicity and efficient biomagnification in the food chain. We engineered several plant species (e.g., Arabidopsis, tobacco, canola, yellow poplar, rice) to express the bacterial genes, merB and/or merA, under the control of plant regulatory sequences. These transgenic plants acquired remarkable properties for mercury remediation. (1) Transgenic plants expressing merB (organomercury lyase) extract methylmercury from their ...
This paper reviews the mill flowsheet applied at the COMINAK uranium mill (Compagnie Miniere d'Akouta) in Niger. For ore treatment, it focuses on the major improvements to the operations using sulfonitric pugging and solids/liquid separation using belt filter double filtration after leaching. The precipitation circuits have been improved with molybdenum elimination through caustic washing of the yellow cake. (author)
To the crushed ore leaching is applied. The resulting solid-liquid mixture is fed to a hydro-cyclon grading facility; here the superfine grain is separated before the concentrated mixture can be filtered or centrifuged. The grading is done in several steps. From the liquid, ultimately ridded of the solid, uranium compounds are precipitated and the yellow cake is obtained. (DG).
The goal of this study was to identify and characterize the hypothesized apical cation/H+ exchanger responsible for K+ and/or Na+ secretion in...Full Text Available
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.
Full text: Pigments possessing the ability to confer high solar reflectance have received considerable attention in recent years. The inorganic class of NIR reflective pigments are mainly metal oxides and are primarily employed in two applications: (i) visual camouflage and (ii) reducing heat build up. More than half of the solar radiation consists of near-infrared radiation (52%), the remaining being 43% visible light and 5% ultraviolet radiation. Over heating due to solar radiation negatively affects comfort in the built environment and contributes substantially to electrical consumption for air conditioning and release of green house gases. A pigment which has strong reflections in the NIR region (780-2500 nm) can be referred to as a 'cool' pigment. However, most of the NIR reflective inorganic pigments particularly yellow (eg. cadmium yellow, lead chromate, chrome titanate yellow etc.) contain toxic metals and hence ...
Photosynthetic carbohydrates from the leaves are exported through the phloem to growing tips, roots, flowers and fruits. If sucrose labelled with {sup 14}C is applied to the leaves of bean plants, the pathway for sugar movement may be readily observed by autoradiography. Students apply the labelled sucrose during class time and return the next day to press their plants. During the next class, the pressed and dried plants are placed against X-ray film and left in the dark for four weeks. the film is then developed, examined for presence of label and compared to the pressed plants. Source to sink movement is clearly illustrated and information about the mechanism of phloem transport and loading is gained through experimental treatments, which include blocking the phloem pathway and inhibiting energy production.
The petroleum ether fraction (PEF) from the EtOH extract of flowers and buds of Chrysanthemum indicum was evaluated on antinociception in mice using chemical and thermal models of nociception. PEF administered orally at doses of 188 and 376mg/kg produced significant inhibitions on chemical nociception induced by intraperitoneal acetic acid, subplantar formalin or capsaicin injections and on thermal nociception in the tail-flick test and the hot plate test. In the pentobarbital sodium-induced sleep time test and the open-field test, PEF neither enhanced the pentobarbital sodium-induced sleep time nor impaired the motor performance, indicating that the observed antinociception was unrelated to sedation or motor abnormality. In a measurement of core body temperature, PEF did not affect temper...
Eremostachys laciniata (L) Bunge (family: Lamiaceae alt. Labiatae; subfamily: Lamioideae) is one of the 15 endemic Iranian herbs of the genus Eremostachys. A decoction of the roots and flowers of E. laciniata has traditionally been taken orally for the treatment of allergies, headache and liver diseases. Three antibacterial iridoid glucosides, phloyoside I (1), phlomiol (2) and pulchelloside I (3) have been isolated from the rhizomes of this plant. The structures of these compounds were elucidated unequivocally by a series of 1D and 2D NMR analyses. The antibacterial activity and brine shrimp toxicity of these compounds were assessed using the resazurin microtitre assay and the brine shrimp lethality assay, respectively. All three iridoid glycosides 1-3 exhibited from low to moderate level...
We report here a many-year study of the qualitative and quantitative content of flavonoids in the reproductive organs of the showy tick trefoil (Desmodium canadense (L.) DC., Fabaceae) - stems, leaves, buds, inflorescences,pods, and seeds - collected at different phases of growth at the Department of Medicinal Plants, Kaunas Botanical Garden, Vytautas Magnus University. HPLC studies identified 15 aglycone and glycoside flavonoids: apigenin, apigenin-7-O-glycoside, luteolin, rutin, vicenin-2, vitexin, isovitexin, vitexin rhamnoside, orientin, homoorientin, quercetrin, quercetin, hyperoside, astralagin, and kaempferol. The largest quantities of flavonoids in the vegetative organs from year 2 to year 4 of plant growth were present in the leaves (2.64% and 2.61% at budding and flowering in the...
Recent central processing of domestic wastewater in Malaysia has initiated investigations into the disposal/utilization of the sewage sludge produced. We had conducted an experiment to investigate the feasibility of using dewatered sewage sludge and coconut coir as a peat substitute in a potting medium for chrysanthemum. The experiment involved 9 treatments with sewage sludge (SS) and coconut coir (CC) mixed in different ratios (v/v) to replace peat in the standard potting medium of 3:2:1 (soil: peat: sand).The potting medium contained the following treatments, T1: peat + recommended rates of Agroblend (Ag), a slow release fertilizer, and Grofas (Gf), a foliar fertilizer (commonly used medium and fertilization), T2: [1SS:1CC] + Ag, T3: [1SS:1CC] + half recommended rates of Agroblend and Grofas (1/2Ag + 1/2Gf), T4: [2SS:1CC] + Ag, T5: [2SS:1CC] + 1/2Ag + 1/2Gf, T6: [3SS:1CC] + Ag, T7: [3SS:1CC] + 1/2Ag + 1/2Gf, T8: [4SS:1CC] + Ag, and T9: [4SS:1CC] + 1/2Ag + 1/2Gf; laid-out in a ...
The research work carried out on mutation breeding in Egypt during the 1980s is summarized. Several mutations have been developed in bread wheat, maize, rice and barley. A higher yield, tolerance to salinity, shorter types and earliness were obtained after use of different mutagens and growth regulators. Great attention has been paid to the fababean and chickpea, particularly in improving their quality and quantity of protein, and their resistance to insect weevils such as Callosobruchus sp. Tolerance or resistance to broom rape has also been reported. Various grain legumes such as lentil, pea, cowpea, bean, fenugreek and lupin received some attention. Mutation work on fibre crops such as cotton, kenaf and flax has led to some promising results. Zero type, glandless and early maturing mutants were obtained in cotton, and early flowering, high yielding (fibre or oil) mutants in flax. Some attention has been given to oil crops such as sesame, rapeseed, peanuts, ...
The Anadenathera macrocarpa, Schinus molle, Hymenaea courbaril, Cariniana legalis, Solidago microglossa and Stryphnodendron barbatiman, were collected ''in natura'' samples (leaves, flowers, barks and seeds) from different commercial suppliers. The pharmaco-active compounds in ethanolic extracts had been made by the Mato Grosso Federal University (UFMT). The energy-dispersive x-ray fluorescence (ED-XRF) spectrometry was used for the elemental analysis in different parts of the plants and respective ethanolic extracts. The Ca, Cl, Cu, Fe, K, Mg, Mn, Na, Ni, P, Rb, S, Sr and Zn concentrations were determined by the fundamental parameters method. Some specimens showed a similar inorganic profile for ''in natura'' and ethanolic extract samples and some ones showed a distinct inorganic profile. For example, the Anadenathera macrocarpa showed a similar concentration in Mg, P, Cu, Zn and Rb elements ...
Field cage studies were carried out to evaluate the F_1 sterility technique for population suppression of the pink bollworm, Pectinophora gossypiella (Saunders), in cotton. For this purpose, six field cages (1.8 m x 1.8 m x 1.8 m) were placed over cotton seedlings in the field. Five pairs of laboratory reared, untreated adult moths were released in all six cages during the first week of August. In addition, on the same data 100 pairs of adults, following irradiation of the mature pupae at 100 Gy, were released in two cages and 250 such pairs of irradiated adults in two other cages in ratios of 20:1 and 50:1 (irradiated:normal), respectively. The results of per cent larval infestation in the rosette blooms in different field cages indicated that larval infestation in the flowers was significantly lower (4.93%) in cages where the moths were released at the 50:1 ratio than in cages where moths were released at the 20:1 ratio (6.71%). Larval infestation in the ...
Yellow-emitting pulsed laser operation of an Al/sub 0.37/Ga/sub 0.15/In/sub 0.48/P/Al/sub 0.16/Ga/sub 0.36/In/sub 0.48/P/ Al/sub 0.37/Ga/sub 0.15/In/sub 0.48/P double heterostructure laser diode was obtained at 77 K. The emission wavelength was 579 nm. The threshold current density was 5.6 kA/cm/sup 2/ for a diode with a Si/sub 3/N/sub 4/ insulated 8-..mu..m-wide and 250-..mu..m-long stripe geometry. The device was made from a DH wafer grown by conventional metalorganic chemical vapor deposition using triethyl metals and phosphine as source materials.
Chloride-induced pitting corrosion of stainless steel (Materials No. 1.4301 and 1.4571) was investigated with the aid of chronopotentiostatic tests. Oxide films upon the surface (temper colours), addition of inhibitors (sulphate and nitrate) and temperature were the testing variables. Two different critical pitting potentials have been found, which give information on the potential ranges for stable passivity, latent and stable pitting corrosion. The results only indicate a small effect of Mo content of the material and test temperature. The inhibitors (sulphate and nitrate) have a marked effect. Specimens with a clean surface produced by pickling are markedly more resistant against pitting corrosion than specimens with a yellow temper colour, whereas the difference in corrosion resistance between yellow and blue films is relatively small. The width of the critical potential range for pitting corrosion generally increases with increasing oxide ...
The geology and resources of the lower Yellow Creek area, an area at the northwestern margin of the Piceance Creek basin comprising of four 7.5-minute quadrangles, are described. Subsurface face rocks penetrated by drill holes range in age from Pennsylvania to Cretaceous. Measured sections show the Mancos Shale and the Castlegate Sandstone, Iles Formation, and Williams Fork Formation of the Mesaverde Group of Late Cretaceous age and the Fort Union, Wasatch, Green River, and Uinta formations of Tertiary age. Surficial deposits of Quaternary age include terrace gravels, alluvium, and landslides. Fold axes and faults in the area trend northwesterly. The southern part of the area contains major oil-shale resources. Coal-bearing zones in the Williams Fork and Iles formations contain considerable coal. The coal-resources potential is limited, however, by nonpersistence of the thicker coal beds. Small amounts of gas have been produced from shallow, lenticular Tertiary ...
The AlGaInP materials system has recently supported the development of a variety of visible diode laser devices at wavelengths ranging from yellow to red. Presently, the majority of published results are with materials prepared by organometallic vapor phase epitaxy (OMVPE). Many issues with such materials exist, including impurity doping, the role of crystal ordering, defect formation during epitaxial growth, and the proper quantum well heterostructure design required for best device results. This paper addresses these topics and reviews the present state of the art, and projects the anticipated results when the materials' problems have been solved.
Approximately 1.2 million kg of uranium oxide (yellow cake) has been produced from the area surrounding Gunnison, Colorado. Over 99 percent of this has come form the Cochetopa and Marshall Pass districts. Uranium in both districts and many of the other occurrences is associated closely with fault and shear zones which cut brittle host formations (sandstones and dolomites) of Paleozonic and Mesozoic age. Minor uranium occurrences are in pegmatites and shear zones in Precambrian rocks, Cambrian vein material, and sandstones of Tertiary age. In the paper presented, the uranium occurences are described by districts. In addition, possibilities for additional discoveries are discussed. (JMT)
Radiological hazard in uranium mining and milling operations are primarily due to exposure to external beta and gamma radiation as well as to airborne radionuclides which consist of radon and its short-lived daughter products. In May 1981 a radiological survey programme was performed in order to make a general assessment of the radiation hazards associated with the uranium mines and the Uranium Pilot Plant operated by the M.T.A. Institute in the Koprubasi district of the Manisa province. In this paper a preliminary radiological risk evaluation attempt is presented based on the radiation and radioactivity measurements performed in this district in May 1981.
The reactor fuel cycle based on uranium is described. The various stages in the cycle include mining of uranium ores followed by crushing and grinding, leaching and purification of leach liquor by ion exchange resin process or solvent extraction process, refining of uranium concentrate (yellow cake) by digesting with HNO_3 and then solvent extracting uranyl nitrate with TBP, conversion of uranyl nitrate to uranium hexafluoride, production of uranium metal, uranium enrichment, fabrication of reactor fuel elements and reprocessing of the spent fuel. Chemical reactions wherever they are involved are explained. (M.G.B.).
Homestake Ore from the Ambrosia Lake District of New Mexico was treated in the Alkaline Leach-- Filtration Pilot Plant at Grand Junction, Colorado. Detailed information on grinding, leaching, flltration, and precipitation in connection with the processing of this ore is given. Autoclave leaching and continuous yellow cake precipitation were employed. The circuit liquors contnined organic material that was detrimental to clariflcation and precipitation and the results show that ihe ore was amenable to the Alkaline Leach--Filtration process only if a special additive was used. (auth)
This paper first reviews the history of the Port Hope uranium refinery of Eldorado Nuclear Limited. The current processes used for the production of UO_3, UO_2 and UF_6 from yellow cake are then discussed. Recent process changes and developments in the areas of solvent extraction and UO_3 production together with new processes for the production of ceramic UO_2 and UF_4, are described. Environmental and waste management problems, progress and solutions are next considered. Finally, some experience in siting a new UF_6 refinery, with respect to Environmental Impact Statements and public hearings, conclude the paper. (author).
This paper describes the development and a detailed analysis carried out on the luminescence characteristics of Pr{sup 3+} doped ZrF{sub 4}-BaF{sub 2}-LaF{sub 3}-YF{sub 3}-AlF{sub 3}-NaF glasses. In the present work our objectives are to elucidate the possible mechanisms that are responsible for NIR to red upconversion process and yellow to blue upconversion emission in terms of energy level schemes from the praseodymium containing fibre optical glass composition. We have studied their different physical and optical properties. Besides our investigation on the upconversion emission of these glasses, normal fluorescence studies have also been undertaken in explaining the mechanisms in demonstrating bright red and blue emissions upon excitations at visible and UV wavelengths. Besides these measurements works, a bright blue colour emission was observed under an UV source (202 nm) and upconverted prominent red emissions were observed with a laser diode (LD of 980 nm). ...
Grain refinement behavior of copper alloys cast in permanent molds was investigated. This is one of the least studied subjects in copper alloy castings. Grain refinement is not widely practiced for leaded copper alloys cast in sand molds. Aluminum bronzes and high strength yellow brasses, cast in sand and permanent molds, were usually fine grained due to the presence of more than 2% iron. Grain refinement of the most common permanent mold casting alloys, leaded yellow brass and its lead-free replacement EnviroBrass III, is not universally accepted due to the perceived problem of hard spots in finished castings and for the same reason these alloys contain very low amounts of iron. The yellow brasses and Cu-Si alloys are gaining popularity in North America due to their low lead content and amenability for permanent mold casting. These alloys are prone to hot tearing in permanent mold casting. Grain refinement is one of the ...
Discussions were given on the characteristics of a diesel engine to emit unburned hydrocarbon (HC) created in a long idling operation. The engine tested in the experiment is a direct injection diesel engine with six water-cooled were investigated varying the jet hole diameter and length of the jet nozzle. In the initial operation period, the HC showed high values. This is thought because part of the injected fuel has deposited on the wall because of low combustion chamber wall temperature, and the fuel deposit that did not evaporate during combustion evaporated during expansion process and emitted unburned. The head was dismantled to investigate the carbon flowers deposited on the nozzle and the relationship between the carbon and the HC deposited on the head face and the combustion chamber wall. It was clarified that the HC increase was phenomenal compared with that of the carbon. This is because the injected fuel was adsorbed into the carbon, part of it remained ...
Six species having characteristics of plants with the C(4) dicarboxylic photosynthetic pathway, Echinochloa utilis L. Ohwi et Yabuno (Japanese millet), Cynodon dactylon L. (Bermuda grass), Kyllinga brevifolia Rottb., Amaranthus tricolor L. cv. Early splendour, Kochia childsii Hort., and Portulaca grandiflora Hook (rose moss), responded decisively to 0.1 milliequivalent per liter NaCl supplied to their culture solutions initially containing less than 0.08 microequivalent per liter Na. Chlorosis and necrosis occurred in leaves of plants not receiving sodium. Portulaca failed to set flower in the sodium-deficient cultures. Under similar conditions Poa pratensis L. (Kentucky blue grass) having characteristics of the C(3) photosynthetic pathway made normal growth and did not respond to the addition of sodium. It is concluded from these results and previously reported work that sodium is generally essential for species having the C(4) pathway but not for species with the ...
Six species having characteristics of plants with the C4 dicarboxylic photosynthetic pathway, Echinochloa utilis L. Ohwi et Yabuno (Japanese millet), Cynodon dactylon L. (Bermuda grass), Kyllinga brevifolia Rottb., Amaranthus tricolor L. cv. Early splendour, Kochia childsii Hort., and Portulaca grandiflora Hook (rose moss), responded decisively to 0.1 milliequivalent per liter NaCl supplied to their culture solutions initially containing less than 0.08 microequivalent per liter Na. Chlorosis and necrosis occurred in leaves of plants not receiving sodium. Portulaca failed to set flower in the sodium-deficient cultures. Under similar conditions Poa pratensis L. (Kentucky blue grass) having characteristics of the C3 photosynthetic pathway made normal growth and did not respond to the addition of sodium. It is concluded from these results and previously reported work that sodium is generally essential for species having the C4 pathway but not for species with the C3 ...
One of the most important factors affecting the postharvest life and quality of horticultural crops is temperature. Quality loss after harvest occurs as a result of physiological and biological processes, the rates of which are influenced primarily by product temperature. As the maintenance of market quality is of vital importance to the success of the horticultural industry, it is necessary not only to cool the product but to cool it as quickly as possible after harvest. The process of precooling is the removal of field heat which arrest the deteriorative and senescence processes so as to maintain a high level of quality that ensures customer satisfaction. This paper provides a critical review to portray precooling as an intricate part of temperature management and to highlight the importance of its utilisation for extending the shelf life and maintaining the quality of horticultural products with emphasis on cut flowers. Various different precooling methods are ...
Wonderful opportunities await particle physics over the next decade, with the coming of the Large Hadron Collider at CERN to explore the 1-TeV scale (extending efforts at LEP and the Tevatron to unravel the nature of electroweak symmetry breaking) and many initiatives to develop our understanding of the problem of identity: what makes a neutrino a neutrino and a top quark a top quark. Here I have in mind the work of the B factories and the Tevatron collider on CP violation and the weak interactions of the b quark; the wonderfully sensitive experiments at Brookhaven, CERN, Fermilab, and Frascati on CP violation and rare decays of kaons; the prospect of definitive accelerator experiments on neutrino oscillations and the nature of the neutrinos; and a host of new experiments on the sensitivity frontier. We might even learn to read experiment for clues about the dimensionality of spacetime. If we are inventive enough, we may be able to follow this rich menu with the physics opportunities ...
Soils of arid regions of Central Asia contain salts of different types that may differentially affect seed germination and plant development. We studied effect of NaCl, Na2SO4, 2NaCl + KCl + CaCl2 and 2Na2SO4+K2SO4+MgSO4 on germination of Kochia prostrata and Kochia scoparia seeds under a range of concentrations from 0.5 to 5% and at two constant temperature regimes +22 degrees C and +6 degrees C. The observed salt tolerance limit of germination at constant temperature +22 degrees C for both species was 5-6%, while at low temperature (+6 degrees C) this limit was 2%. The salt tolerance of young plants (before flowering) was 3% for NaCl. Low concentrations of sulfuric and mixed salts had a stimulating effect on seed germination in K. prostrata. Despite similarity of salt-tolerance limits...
Cooling towers of power plants are used to dissipate waste heat into the atmosphere. If saline water is used for cooling, a saline aerosol known as drift is released into the atmosphere. Drift effects on vegetation are not well known. To simulate drift for a field study, cooling tower basin water was sprayed thirty separate times during a 46-day period in 1975 on Virginia pine (Pinus virginiana), flowering dogwood (Cornus florida), tulip tree (Liriodendron tulipfera), and California privet (Ligustrum ovalifolium), Norway spruce (Picea abies), and white ash (Fraxinus americana) were added in 1976 and all trees were sprayed 43 times during a 59-day period. Only dogwood leaves showed significant injury. Absence of injury on other species was probably due to the ability of their leaves to exclude, or reduce absorption of, toxic concentrations of the ions supplied.
Thermodynamic data has been selected for solids and aqueous species of technetium. Equilibrium constants have been calculated in the temperature range 0 to 300 deg C at a pressure of 1 bar for T<100 deg C and at the steam saturated pressure at higher temperatures. For aqueous species, the revised Helgeson-Kirkham-Flowers model is used for temperature extrapolations. The data base contains a large amount of estimated data, and the methods used for these estimations are described in detail. A new equation is presented that allows the estimation of #DELTA#_rCdeg_p_m values for mononuclear hydrolysis reactions. The formation constants for chloro complexes of Tc(V) and Tc(IV), whose existence is well established, have been estimated. The majority of entropy and heat capacity values in the data base have also been estimated, and therefore temperature extrapolations are largely based on estimations. The uncertainties derived from these calculations are described. Using ...
Upon addition of permanganate to a solution of tryptophan (Trp), yellow-brown color species appears within the time of mixing of tryptophan in absence and presence of cetyltrimethylammonium bromide (CTAB), which was stable for some days. Spectroscopic and kinetic evidences suggest the formation of water-soluble colloidal MnO2 as the most stable reduction product of MnO4-. Carbon dioxide and ammonia are not formed as the oxidation products. Carbon-carbon double bond of indole moiety of Trp is responsible for the fast reduction of permanganate. Cetyltrimethylammonium bromide catalyses the permanganate oxidation of Trp with a rate enhancement of ca. 200-fold. Sub- and postmicellar catalytic effect of CTAB ascribed to the association/incorporation/solubilization of both reactants (MnO4- and Tr...
Insect attraction to host plants may be partly mediated by visual stimuli. In the present study, the responses of adult Hycleus apicicornis (Gur.) (Coleoptera: Meloidae) to plant models of different colours, different combinations of two colours, or three hues of blue of different shapes are compared. Single-colour models comprised the colours sky blue, bright green, yellow, red, white and black. Sky blue (reflecting light in the 440-500 nm region) is the most attractive, followed by white, which reflects light over a broader range (400-700 nm). On landing on sky blue targets, beetles exhibit feeding behaviour immediately. When different hues of blue (of different shapes) are compared, sky blue is preferred over turquoise, followed by dark blue, indicating that H. apicicornis is more attra...
During their catalytic cycle, proteins involved in biological signal transduction undergo unexpectedly large conformational changes, which are at the core of their biological functioning. Until now it has been extremely difficult to obtain experimental insight into the nature of these conformational changes. Mathematical modeling and time-resolved X-ray crystallography have resulted in probable routes along which these conformational changes may take place, but so far this fundamental biological phenomenon has hardly been tackled experimentally. Here, we report on an attempt to observe structural changes in Photoactive Yellow Protein with time-resolved small-angle neutron scattering using diffractometer D22 at the high-flux reactor of the Institut Laue-Langevin, Grenoble, France.
During their catalytic cycle, proteins involved in biological signal transduction undergo unexpectedly large conformational changes, which are at the core of their biological functioning. Until now it has been extremely difficult to obtain experimental insight into the nature of these conformational changes. Mathematical modeling and time-resolved X-ray crystallography have resulted in probable routes along which these conformational changes may take place, but so far this fundamental biological phenomenon has hardly been tackled experimentally. Here, we report on an attempt to observe structural changes in Photoactive Yellow Protein with time-resolved small-angle neutron scattering using diffractometer D22 at the high-flux reactor of the Institut Laue-Langevin, Grenoble, France
A process is described for the recovery of uranium values from phosphoric acid utilizing an alkyl pyrophosphoric acid (Appa) primary extractant. After extracting the uranium from the phosphoric acid, the appa extractant is deactivated by heating and the uranium values stripped into a phosphoric acid strip solution containing ferric ion as a salting agent. The uranium values may then be re-extracted directly from this stripping solution without adjustment of its concentration into a dialkyl phosphoric acid trialkyl phosphine oxide synergistic extractant from which a relatively pure yellow cake is precipitated. A new procedure for preparing the requisite appa primary extractants is also disclosed.
Red laser diodes emitting at 636 nm and 645 nm are studied as a function of pressure up to 20 kbar and temperature from 300 K down to 80 K. The 636 nm samples reveal anomalous L-I-V dependence at low temperatures and at high pressures. The 645 nm samples do not show these anomalies and can be tuned by pressure and temperature down to 575 nm, i.e., in the 70 nm range with powers above 200 mW and low threshold currents. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
We identify a source coincident with SN 2009kr in Hubble Space Telescope pre-explosion images. The object appears to be a single point source with an intrinsic color V - I = 1.1 #+-# 0.25 and M_V = -7.6 #+-# 0.6. If this is a single star, it would be a yellow supergiant of log L/L _s_u_n #approx# 5.1 and a mass of 15"+"5 _-_4 M _s_u_n. The spatial resolution does not allow us yet to definitively determine if the progenitor object is a single star, a binary system, or a compact cluster. We show that the early light curve is similar to a Type IIL SN, but the prominent H#alpha# P-Cygni profiles and the signature of the end of a recombination phase are reminiscent of a Type IIP. The evolution of the expanding ejecta will play an important role in understanding the progenitor object.
A study of the influence of the concentration of secondary addition, high concentrations of primary dopant, diffusion enhancer and stabilizer on radiation hardness is presented. It is concluded that the diffusion enhancing technique is the most powerful method for improving radiation hardness. A new polystyrene scintillator which contains 2% pT, 0.02% POPOP, 20% diffusion enhancer and 0.02% stabilizer gave 91% of initial light output immediately after 3 Mrad irradiation in air. Data are presented that show that scintillator prepared from commercial polymer is more radiation-hard and has greater light output than scintillator prepared from monomer. It is assumed that this difference is due to different molecular weight distributions. Some protocols for acceleration of aging (yellowing and crazing) are presented. It is shown that one of the main reasons for aging of plastic scintillators is residual monomer. 10 refs., 18 figs., 1 tab.
A set of 35 uranium ore and 10 yellow cake samples, collected worldwide from different mines and production sites, were analyzed for their impurity spectrum by ICP-MS. Pattern recognition techniques such as cluster analysis were applied to the data set in order to characterize samples with relation to their geographical origin. The results obtained show a clear relationship between samples taken from the same geological origin and constitute a satisfactory fingerprint for establishing the origin of the material. In addition to the impurity data, data on the isotopic composition of radiogenic lead is used to resolve ambiguity when impurity cluster analysis fails to deliver unambiguous origin data. (author)
Curcumin, the yellow pigment from the rhizoma of Curcuma longa, is a widely studied phytochemical with a variety of biological activities. The ongoing research and clinical trials have proved that this natural phenolic compound has great and diverse pharmacological potencies. Beside its effective antioxidant, antiinflammatory, and antimicrobial/antiviral properties, curcumin is also considered as a cancer chemopreventive agent. While the antioxidant activity of curcumin is well documented, its interaction with DNA and RNA is not fully investigated. This study was designed to examine the interactions of curcumin with calf thymus DNA and yeast RNA in aqueous solution at physiological conditions, using constant DNA and RNA concentration (6.25?mM) and various curcumin/polynucleotide (phosphate...
Old World Bluestems (OWB), introduced from Europe and Asia in the 1920s, recently have begun to raise concerns in the Great Plains. Despite suggestion in the late 1950s that OWB were weedy and negatively impacted biological diversity, they were widely introduced throughout the Great Plains for agricultural purposes. Anecdotal evidence suggests that OWB exhibit invasive characteristics that promote competitive exclusion of native species. The objective of our study was to quantify the competitive abilities of two OWB species (Caucasian bluestem; Bothriochloa bladhii (Retz.) S.T. Blake (=?Bothriochloa caucasica (Trin.) C.E. Hubb.) and yellow bluestem; Bothriochloa ischaemum (L.) Keng) with three native grass species (big bluestem (Andropogon gerardii Vitman), little bluestem (Schizachyrium s...
A research was started aiming at evaluating the possible use of natural zeolites as exchange conditioners to improve and make durable the soil resilience against the adverse effects of the use of anomalous waters for irrigation purposes. This paper deals with a preliminary investigation on the comparative resilience of an Entisol with poor exchange properties and of a Neapolitan yellow tuff (NYT) sample against the adverse features of a dirty municipal sewage (DSW). Results showed that NYT treatment largely and significantly improved the poor soil exchange activity. In particular. NYT exchange sites selectively took up ammonium from DSW. As a consequence, ammonium was trapped, then protected against losses in the environment and, concurrently, exchangeable cations, such as K and Ca, were made free as plant nutrients. The results highlight the possible positive role of zeolitized tuff in restoring and sustaining soil resilience.
Cytophotometric measurements of DNA content after Feulgen's reaction and autoradiography after incubation with "3H-thymidine were performed to investigate the early stages of development of yellow lupin root nodule. The first response of the host plant to the contact with Rhizobium lupini was the enhancement of nuclear DNA endoreplication in root cortex cells. A conversion of the initially mixoploid nodule meristem into a diploid one during root nodule formation was found. Differentiation of bacteroid-containing tissue both from diploid and polyploid cells was observed. The highest content of nuclear DNA in the uninfected root cortex, nodule cortex and in bacteroid-containing tissue was 16 C. (author).
The total amount of uranium dissolved in seawater at a uniform concentration of 3 mg U/m{sup 3} in the world's oceans is 4.5 billion tons. An adsorption method using polymeric adsorbents capable of specifically recovering uranium from seawater is reported to be economically feasible. A uranium-specific nonwoven fabric was used as the adsorbent packed in an adsorption cage 16 m{sup 2} in cross-sectional area and 16 cm in height. We submerged three adsorption cages in the Pacific Ocean at a depth of 20 m at 7 km offshore of Japan. The three adsorption cages consisted of stacks of 52 000 sheets of the uranium-specific non-woven fabric with a total mass of 350 kg. The total amount of uranium recovered by the nonwoven fabric was >1 kg in terms of yellow cake during a total submersion time of 240 days in the ocean.
The total amount of uranium dissolved in seawater at a uniform concentration of 3 mg U/m3 in the world's oceans is 4.5 billion tons. An adsorption method using polymeric adsorbents capable of specifically recovering uranium from seawater is reported to be economically feasible. A uranium-specific nonwoven fabric was used as the adsorbent packed in an adsorption cage 16 m2 in cross-sectional area and 16 cm in height. We submerged three adsorption cages in the Pacific Ocean at a depth of 20 m at 7 km offshore of Japan. The three adsorption cages consisted of stacks of 52 000 sheets of the uranium-specific non-woven fabric with a total mass of 350 kg. The total amount of uranium recovered by the nonwoven fabric was >1 kg in terms of yellow cake during a total submersion time of 240 days in the ocean.
Brazil is the world?s main producer of passion fruit. Previous reports show that passion fruit rinds, an industrial waste, contain large amounts of pectin. Pectin is a dietary fiber that is widely used in the food industry as a gelling agent and stabilizer. In this study, the quality and characteristics of pectin extracted from yellow passion fruit rind flour was investigated. Pectin was extracted from both commercially available and prepared passion fruit peels using nitric acid. Once extracted, the pectin was evaluated for its molecular characteristics and chemical composition as well as for the apparent and reduced viscosity of the gel. Prepared (blanched) rind flour yielded 203.4?g?kg?1 of pectin, which contained a uronic acid content of 681?mg?g?1, a degree of esterification of 80, a ...
The electrochemical treatment of solutions containing C.I. Basic Yellow 2 (BY2) in aqueous solutions with carbon-PTFE (polytetrafluoroethylene) and carbon nanotube (CNT)-PTFE electrodes as cathode has been studied. The fabricated electrodes were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The amount of electrogenerated H2O2 on the surface of these electrodes was investigated, too. The results showed that the amount of H2O2 obtained with the CNT-PTFE electrode was nearly three times higher than that of carbon-PTFE electrode. The decolorization efficiency of BY2 in peroxi-coagulation process reached 62% and 96% in the first 10 min by carbon-PTFE and CNT-PTFE electrodes at 100 mA, respectively. The effect of operational parameters such as applied current, initial pH and initial dye concentration was studied in an attempt to reach higher decolorization efficiency. The degradation and mineralization of BY2 using CNT-PTFE ...
Full text: Nuclear material is subjected to chemical processing throughout the entire fuel cycle. Traces of the chemical reagents and solvents are left behind in the nuclear material. So far essentially metallic impurities or light elements have been investigated for their potential in providing clues on the type of process they originate from. In the present investigation, the applicability of anions for attributing nuclear material to a certain chemical process has been investigated. Anions (e.g. nitrate, sulphate, phosphate, chloride) originate from acids or salt solutions that are used for processing of solutions containing uranium or plutonium. The study presented in this paper focuses on yellow cake samples originating from different mines applying different chemical processes for leaching, dissolving and precipitating the uranium. Consequently, the anionic patterns should be different. The concentrations of different anionic species were measured by ion ...
Non-radiative energy transfers (ET) from Ce3+ to Pr3+ in Y3Al5O12:Ce3+, Pr3+ and from Sm3+ to Eu3+ in CaMoO4:Sm3+, Eu3+ are studied based on photoluminescence spectroscopy and fluorescence decay patterns. The result indicates an electric dipole-dipole interaction that governs ET in the LED phosphors. For Ce3+ concentration of 0.01 in YAG:Ce3+, Pr3+, the rate constant and critical distance are evaluated to be 4.5x10-36 cm6 s-1 and 0.81 nm, respectively. An increase in the red emission line of Pr3+ relative to the yellow emission band of Ce3+, on increasing Ce3+ concentration is observed. This behavior is attributed to the increase of spectral overlap integrals between Ce3+ emission and Pr3+ excitation due to the fact that the yellow band shifts to the red spectral side with increasing Ce3+ concentration. In CaMoO4:Sm3+, Eu3+, Sm3+-Eu3+ transfer occurs from 4G5/2 of Sm3+ to 5D0 of Eu3+. The rate constant of 8.5x10-40 cm6 s-1 and the critical ...
This patent describes an ignition system of an internal combustion engine which consists of: a permanent magnet supported by a rotary member of the engine adapted to rotate in synchronism with a rotary shaft of the engine; a generating coil for generating an electromotive force to produce an electric current as the permanent magnet acts on the generating coil during the rotation of the rotary member; an ignition capacitor charged by the electric current generated by the generating coil; a thyristor caused to turn on by a counter electromotive force generated by the generating coil to thereby cause the ignition capacitor to begin to discharge; and an ignition coil generating a high voltage as the ignition capacitor begins to discharge, to cause a spark discharge to take place in an ignition plug of the internal combustion ...
The improving uranium extraction efficiency of yellow cake production from shale deposit by acid pugging and curing with D263B resin adsorption is described in this paper. The analysis and examination show that the composition of uranium minerals in one of uranium ores is very complex, which directly influence the extraction efficiency of uranium and processing technology. Conventional experimental results indicate that uranium leaching efficiency is changed between 50?60% by conventional agitation method. In this case, acid pugging and curing experiments are employed in order to improving the extraction efficiency. A series of acid pugging and curing experiments are carried out to get parameters for heap leaching in pilot plant experiment. The experiment results by acid pugging and curing technology showed that uranium leaching efficiency can reach to 90% of extraction efficiency mixed with 1% manganese dioxide, 12% sulfuric acid pugging, curing 3 days and leached ...
ABS>A horizontal steam generator design for the SM-2 was lysis to determine the per formance of such a steam generator under steady state operating conditions and during load transients, The configuration for this design is a two- drum unit consisting of a heat exchanger unit and separator drum interconnected by integral riser and downcomer. An analog computer was used to analyze the steam generator behavior Wring load transients. The effect of various design changes on the response of the steam generator to step chages in load was determined. The horizontal steam generator design was compared to the existing vertical steam generator design for weight, size, price, and performance. (auth)
Apparent molar volumes of aqueous methyldiethanolamine and its salt were determined with platinum vibrating tube densitometers over a range of temperatures from 283K=<T=<576K and at pressures from 0.1MPa to 20MPa. Apparent molar heat capacities were obtained using a Sodev Picker flow microcalorimeter at a pressure of 0.1MPa and within the temperature range of 283K=<T=<328K. Apparent molar adiabatic and isothermal compressibilities at a pressure of 0.1MPa were obtained at temperatures from 283K=<T=<313K with speed of sound measurements. The experimental results were extrapolated to infinite dilution to obtain values for the standard partial molar volumes V{sup o}, heat capacities C{sub p}{sup o}, and isothermal compressibilities {kappa}{sub T}{sup o}. The standard partial molar volumes V{sup o} for the neutral amine and its salt show increasingly positive and negative values, respectively, at high temperatures and pressures, as predicted by ...
Apparent molar volumes of aqueous methyldiethanolamine and its salt were determined with platinum vibrating tube densitometers over a range of temperatures from 283K=
Relative densities and relative massic heat capacities have been measured for aqueous solutions of Y(ClO_4)_3, Yb(ClO_4)_3, Dy(ClO_4)_3, and Sm(ClO_4)_3 at T=(288.15,298.15,313.15, and 328.15) K and p=0.1 MPa. These measurements were made in the concentration range 0.01624#<=#m/(mol#centre dot#kg"-"1)#<=#0.41822 using a Sodev 02D Vibrating Tube Densimeter and a Picker Microflow Calorimeter, respectively. To counter the potential effects of hydrolysis, aqueous solutions of the investigated salts were acidified with perchloric acid. After correcting for the presence of the acid, the measured properties were used to calculate apparent molar volumes and apparent molar heat capacities for solutions of the perchlorate salts in water. The calculated apparent molar properties were modeled at each investigated temperature using Pitzer ion interaction equations to produce estimates of apparent molar volumes and heat capacities at infinite dilution. In addition, the temperature dependences ...
The authors have interpreted 1,400 km of industry and government multichannel seismic reflection data from eastern Lake Superior. Seismic sequences have been identified by using reflection character and reflector terminations and truncations. This framework, coupled with outcrop information, has allowed them to assign lithologic units to some of these reflectors and reconstruct the timing and geometry of structures within the basin. The authors have mapped the Base Jacobsville-Bayfield Group/Top oronto Group, Base oronto Group/Top Keweenawan volcanics, and Basement as well as several reflectors internal to these groups. Integration of gravity and magnetic data with the seismic grid permits regional mapping of faults and folds between seismic lines. In the eastern part of the basin, high-angle basement-involved reverse faults, such as the southeastern combination of the Keweenaw fault, trend NNW-SSE, while broad folds trend E-W. The Keweenaw fault is a complex structural zone and, in ...
(1) Young chrysanthemums were planted after being irradiated at the time of shoot tip culture and the influence of irradiation was evaluated from the point of view of establishment of mutants. (2) Two cultivars, Kin-tenryu and Tenryu-no-asa were used in this experiment. The percentage of cultivars healthy enough to transplant on June 10, 1972 showed a decrease in proportion to the increase of dosage. Some plants of cultivar Kin-tenryu died after being transplanted. (3) Few plants of either cultivar could overwinter, and in particular no plant irradiated by gamma-rays of 20 kR. (4) Plant height showed a tendency of inhibition in both cultivars. (5) Three chlorophyll mutants showing chimera appeared. One of them was in the cultivar Tenryu-no-asa irradiated by 10 kR at 3 days after planting; two of them were in the cultivar Tenryu-no-asa irradiated by 10 kR at 5 days after planting. One mutant exhibiting malformation of entire leaves appeared in the cultivar Kin-tenryu irradiated by 20 kR ...
High oleic acid sunflower oils have been commercially available for some years now. Due to their high content of monounsaturated fatty acids these oils have a number of potential applications in the oleochemical industry, especially where technical oleic acids and their derivatives are used. Whereas conventional sunflower oil contains approx. 68% linoleic acid (C{sub 1}8:2), it is now possible through breeding measures to obtain ''new sunflower oils'' (NSb oils) with oleic acid levels of 70-95% oleic acid (C{sub 1}8:1). The oil itself is of interest for technical applications: it is light-coloured, has a neutral odour and is relatively resistant to oxidation. Plant oils, especially those with a low content of polyunsaturated fatty acids, are increasingly gaining interest as ester oils in technical application areas, e.g. as lubricants. However, there are limits to the technical applicability of triglycerides due to their temperature behaviour or ...
Tm3+ and Dy3+ ions co-doped aluminoborosilicate glasses were prepared in this study. The luminescence properties of the glasses were analyzed. A combination of blue, green, yellow, and red emission bands was shown for these glasses, and white light emission could be observed under UV light excitation. White light luminescence color could be changed by varying the excitation wavelength. Concentration quenching effect was investigated in this paper. Furthermore, the dependence of luminescence properties on glass compositions was studied. Results showed that the luminescence intensity changed with different network modifier oxides, while the white color luminescence was not affected significantly. - Graphical abstract: Tm3+ and Dy3+ ions co-doped aluminoborosilicate glasses, which emit white light under UV light excitation, were prepared. The dependence of luminescence properties on glass compositions was studied, and results showed that the white color luminescence ...
The extensive reserves of mined coal types, their great variety and the complexity of the composition and properties, as well as their important role as an energy fuel and industrial feedstock, cause one to give special attention to their classification. Of course, one of the principal fields of technological processing of coal is coking. In addition to the production of blast furnace coke, in the future specialized plants will be developed for production of coke and other carbonized materials for non-blast-furnace processes (electrothermal processes, production of calcium carbide, ferroalloys, zinc, yellow phosphorus, copper, etc.). One important area is new nonfuel uses, including a number of processes for processing of coal feedstocks to obtain a wide range of carbonaceous materials (coal-graphite products, carbon black, adsorbents, etc.), liquid fuels, and chemical products. In choosing a given area of coal utilization a determining factor is the ...
Ultraviolet (UV) photoirradiation of Ag(I) compounds in the presence of an aqueous Triton X-100 solution has been exploited for the first time to prepare reproducible yellow silver hydrosol. The evolution of nanosized silver particles has been examined critically under the influence of different anions/ligands. Hence, time dependent evolution of silver hydrosol from different silver compounds in micelle via photochemical reduction is observed. Anions/ligands of precursor salts have been found to show profound influence (due to electron scavenging property, solubility, stability etc.) on the evolution route and efficiency of photochemical reduction of Ag(I) to Ag(O) in micelle and thereby classification of silver compounds becomes possible. Kinetic results reveal that the formation of silver particles proceeds via autocatalytic growth mechanism. The observed variation in rate constant values for the evolution of nanoparticles from different silver compounds have ...
Lutein is a yellow pigment found in common foods that promotes the health of eyes and skin and is associated with reduced risk of age-related macular degeneration and cataracts. In the present study, selected high-lutein wheat and corn were milled into wholegrain flours by two mills to improve flour uniformity. The high-lutein and lutein-fortified wholegrain flours were processed into breads, cookies, and muffins to study lutein stability during baking and subsequent storage. Lutein and its isomers were separated, identified, and quantified by LC-UV/vis and LC-MS following extraction with water-saturated 1-butanol. Baking resulted in a significant reduction in all-trans-lutein and the formation of cis-lutein and cis-zeaxanthin isomers. Subsequent storage at ambient temperature had a slight impact on the content of all-trans-lutein. Effects of processing were more pronounced in lutein-fortified products, and the degradation rate of lutein was influenced by ...
A rapid and sensitive method for the separation and determination of titanium and iron in thiocyanate system has been developed. The extractability of Ti(II) by high molecular weight (HMWA) in organic solvent (HCl/sub 3/) and its separation from Fe(III) was examined. The yellow coloured complex of Ti(II)-SCN in quantitatively extracted into the organic phase containing tribenzyl tribenzylamine (TBA) - a high molecular weight amine, whereas the blood red coloured complex of Fe(III)-SCN formed under the same conditions get separated in the aqueous phase. On the basis of the selective extractability, a method has been developed for the separation as well as simultaneous determination of Ti(II) and Fe(III) in presence of many other elements. The molar extinction coefficients were found to be 1.9 x 10/sup 5/ l mol/sup -1/ cm/sup -1/ and 1.11 x 10/sup 5/ l mol/sup -1/ cm/sup -1/ respectively for Ti(II) and Fe(III). The extractability of the complex of fully applied to ...
Differentiating a benign from a malignant lesion by information such as density data, or signal intensities or echo gradients, is not possible with CT, nor MRI, nor ultrasonography. Only some lesions show characteristic signs. Inflammations cannot be difscriminated from malignant tumors. CTs of small tumors in particular are so poor in contrast that it is much more difficult to detect tumors or discriminate them from other lesions, as compared to MR images or ultrasonographs. CT does not detect surface tumors, but is more sensitive than MRI or US in detecting discrete cortical bone lesions. The same applies to small calcified tumors. MRI however is most sensitive in detecting tumor volumes in the yellow marrow, and is the best modality for evaluation of extraossal extension of tumors. CT yields better results than MRI if applied for simultaneous screening of lymph node metastases in the lower neck. MRI frequently is spoilt by movement artefacts. High-resolution, ...
Anatomical specimens and normal persons were studied by gradient echo MR imaging to determine the influence of different echo times (TE) on bone marrow contrast. First of all, six normal persons were studied to determine specific echo times for in-phase and opposed-phase states. Using different sequences bone marrow contrast in isolated femoral bones was determined and compared to results of pathological exams. Red bone marrow had no signal on opposed-phase images; contrast between red and yellow marrow was higher on opposed-phase than on in-phase images. Bone marrow lesions can be expected to be visualised with high signal on opposed-phase images; this technique should be especially suited for MR imaging of bone marrow. (orig.).
Through DNA methylation, histone modifications, and small regulatory RNAs the epigenome systematically controls gene expression during development, both in utero and throughout life. The epigenome is also a very reactive system; its labile nature allows it to sense and respond to environmental perturbations to ensure survival during fetal growth. This pliability can lead to aberrant epigenetic modifications that persist into later life and induce numerous disease states. Endocrine-disrupting compounds (EDCs) are ubiquitous chemicals that interfere with growth and development. Several EDCs also interfere with epigenetic programming. The investigation of the epigenotoxic effects of bisphenol A (BPA), an EDC used in the production of plastics and resins, has further raised concern over the impact of EDCs on the epigenome. Using the Agouti viable yellow (A(vy)) mouse model, dietary BPA exposure was shown to hypomethylate both the A(vy) and the Cabp(IAP) metastable ...
Passion fruit (Passiflora edulis f. flavicarpa L.) yellow variety is composed of 50-55g peel per 100g of fresh fruit which is discarded as waste during processing. Utilization of passion fruit peel for pectin extraction was studied. Passion fruit peel obtained after juice extraction was blanched in boiling water for 5min, dehydrated in a cross flow hot air drier at 60+-1degreeC to a moisture content of 4g/100g of dried peel. The dehydrated passion fruit peel was used for extraction experiments of pectin. The effect of pH, peel to extractant ratio, and number of extractions, extraction time and temperature on the yield and quality characteristics of pectin were investigated. The optimized conditions for extraction of pectin from passion fruit peel yielded 14.8g/100g of dried peel. Pectin ex...
Economic analysis was performed at KAERI with the assistance of US DOE to compare single reactor fuel cycle costs for a once-through option and a thermal recycle option to operate 1 GWe of a PWR plant for its lifetime. A reference fuel cycle cost was first calculated for each option with best estimated reference input data. Then a sensitivity analysis was performed changing each single value of such fuel cycle component costs as yellow cake price, enrichment charges, spent fuel storage cost, reprocessing cost, spent fuel disposal cost and reprocessing waste disposal cost. Savings due to thermal recycle in requirements of uranium, conversion, and enrichment were examined using formulas suggested by US DOE, while MOX fabrication penalty was accounted for. As a result of the reference fuel cycle cost analysis, it is calculated that the thermal recycle option is marginally more economical than the once-through option. The major factors affecting the comparative costs ...
Thorium-230, together with "2"3"8U and "2"2"6Ra, was determined (mainly by #gamma#-spectrometry) in samples from the waste piles at Borst and Jazbec in the vicinity of the former uranium mine at Zirovski vrh, Slovenia. Activity (and in the case of uranium, also mass) balances for these nuclides were constructed for the overall operation of the mine and yellow cake plant, using experimental data and known data on ore and uranium production, and nuclide emissions to the environment. All the "2"2"6Ra resulting from ore exploitation is presently contained in the Borst tailings pile. However, because of the very high content of "2"3"0Th in red mud deposited at Jazbec, where 60% of this nuclide is found, the majority of "2"2"6Ra will be found at the Jazbec pile in the future, due to its ingrowth from "2"3"0Th over the next few thousand years. (Author).
Macrophage differentiation antigen associated with complement three receptor function (Mac-1) belongs to #beta#_2 subfamily of integrins that mediate important cell-cell and cell-extracellular matrix interactions. Biochemical studies have indicated that Mac-1 is a constitutive heterodimer in vitro. Here, we detected the heterodimerization of Mac-1 subunits in living cells by means of two fluorescence resonance energy transfer (FRET) techniques (fluorescence microscopy and fluorescence spectroscopy) and our results demonstrated that there is constitutive heterodimerization of the Mac-1 subunits and this constitutive heterodimerization of the Mac-1 subunits is cell-type independent. Through FRET imaging, we found that heterodimers of Mac-1 mainly localized in plasma membrane, perinuclear, and Golgi area in living cells. Furthermore, through analysis of the estimated physical distances between cyan fluorescent protein (CFP) and yellow fluorescent protein (YFP) fused ...
The 2,860-acre Conforth Ranch near Umatilla, Oregon is being considered for acquisition and management to partially mitigate wildlife losses associated with McNary Hydroelectric Project. The Habitat Evaluation Procedures (HEP) estimated that management for wildlife would result in habitat unit gains of 519 for meadowlark, 420 for quail, 431 for mallard, 466 for Canada goose, 405 for mink, 49 for downy woodpecker, 172 for yellow warbler, and 34 for spotted sandpiper. This amounts to a total combined gain of 2,495 habitat units -- a 110 percent increase over the existing values for these species combined of 2,274 habitat units. Current water delivery costs, estimated at $50,000 per year, are expected to increase to $125,000 per year. A survey of local interest indicated a majority of respondents favored the concept with a minority opposed. No contaminants that would preclude the Fish and Wildlife Service from agreeing to accept the property were identified. 21 refs., ...
Design process of steam generator and condenser at Russian nuclear power plant type WWER-1000 is identified. The four chapter of the books are organized as nuclear power plant, types of steam generators specially horizontal steam generator, process of steam generator design and the description of condenser and its process design.
Analytical relations are obtained for estimating how the distributions of temperature and heat flux vary along a steam-generating tube and how the steam-generator power output reduces due to formation and accumulation of deposits.
Analytical relations are obtained for estimating how the distributions of temperature and heat flux vary along a steam-generating tube and how the steam-generator power output reduces due to formation and accumulation of deposits.
The effect of the water-chemical regime (WCR) on damage sustained by heating surfaces of steam generators at NPP is analyzed. It is indicated that phosphate treatment with minimal excesses of phosphates in the steamgenerator water is the most optimal method of managing the WCR regime of horizontal steam generators.
1. Nitric oxide generation is important in the regulation of resistance vessel tone. Until now, however, there has been no evidence of such a role for basal generation of nitric oxide in the skin microcirculation...Full Text Available
IntroductionThe aim of the study was to assess and classify incidents of electromagnetic interference (EMI) by second-generation and third-generation mobile phones on critical care...Full Text Available
Statistical data on experience gained from operation of steam generators around the world are presented, problems arising in vertical and horizontal steam generators are described, and the conditions of heattransfer tubes used in them are compared.
Results are described of a study and of the characteristics of sources of a non-equilibrium gas-discharge plasma. The plasma generators considered include glow, high frequency, and arc discharge generators. Thermodynamic, ionic, and electronic processes occurring in the plasmas are evaluated.
The general objective of the International Seminars of Horizontal Steam Generator Modelling has been the improvement in understanding of realistic thermal hydraulic behaviour of the generators when performing safety analyses for VVER reactors. The main to...
The main problems encountered during the operation of horizontal steam generators are considered. Design features of the new PGV-1000MK and PGV-1500 steam generators are analyzed.
The thermal-hydraulic tests for a horizontal steam generator of a next-generation PWR (New PWR-21) were performed. The purpose of these tests is to understand the thermal-hydraulic behavior in the secondary side of horizontal steam generator during the plant normal operation. A test was carried out with cross section slice model simulated the straight tube region. In this paper, the results of the test is reported, and the effect of the horizontal steam generator internals on the thermal-hydraulic behavior of the secondary side and the circulation characteristics of the secondary side are discussed. (author)
The thermal-hydraulic tests for a horizontal steam generator of a next-generation PWR (New PWR-21) were performed. The purpose of these tests is to understand the thermal-hydraulic behavior in the secondary side of horizontal steam generator during the plant normal operation. A test was carried out with cross section slice model simulated the straight tube region. In this paper, the results of the test is reported, and the effect of the horizontal steam generator internals on the thermal-hydraulic behavior of the secondary side and the circulation characteristics of the secondary side are discussed. (author).
... of waste food generated at McMurdo Station. Some of the difficulties of disposing of waste food ... change waste generation or management at the site? Yes. This will be a temporary waste management ...
We investigate the solar neutrino problem in the scenario of three generation neutrino oscillation hypothesis, taking into account other phenomenological constraints to the neutrino mixing and mass parameters.
This perspective view of Venus, generated by computer from NASA's Magellan data and color-coded with emissivity, shows part of the lowlands to the north of ...
This dissertation is devoted to the study of the phenomenological consequences of the three-generation heterotic string models based on the Calabi-Yau compactifications and the N = 2 superconformal constructions.
This paper describes the construction of PWR horizontal steam generator in Soviet Union, the water chemistry treatment for secondary side, the design of steam separator, the test of heat transfer characteristics and operation. (author).
Network generators that capture the Internet's large-scale topology are crucial for the development of efficient routing protocols and modeling Internet traffic. Our ability to design realistic generators...Full Text Available
The results obtained from experimental investigations and mathematical simulation of horizontal steam generators are considered. Recommendations for continuing these works are given.
This paper presents a new method and newly developed stabilizing equipment to prevent the loss of synchronism of generators in pumped-storage plants from spreading. The proposed method includes functions to estimate the swing of each generator by using on-line generator output sampled at a rate of 600 times per second after an occurrence of disturbance such as fault, faulty equipment and so on, to predict generator swing 200-300 milliseconds ahead and loss of synchronism between generators in pumped-storage plants and those in thermal and nuclear plants, and to decide the number of generators that must be shed to maintain stability. Tokyo Electric Power Co. (TEPCO) installed the newly developed stabilizing equipment based on this method in the power system in June, 1986.
This paper presents a new method and newly developed stabilizing equipment to prevent the loss of synchronism of generators in pumped-storage plants from spreading. The proposed method includes functions to estimate the swing of each generator by using on-line generator output sampled at a rate of 600 times per second after an occurrence of disturbance such as fault, faulty equipment and so on, to predict generator swing 200-300 milliseconds ahead and loss of synchronism between generators in pumped-storage plants and those in thermal and nuclear plants, and to decide the number of generators that must be shed to maintain stability. Tokyo Electric Power Co. (TEPCO) installed the newly developed stabilizing equipment based on this method in the power system in June, 1986.
Additional measurements have been made of deposition and retention of inhaled radioactively labeled iron oxide aerosols generated by a spinning top aerosol generator.
Several proposals have been made on the method of calculating generation of formaldehyde released from plywood. In calculating generation per hour of a volatile organic compound of adhesives or coatings using a chamber method, such models are frequently used that the generation is largest when the specimen is exposed in the chamber and that the generation attenuates with lapse of time. In the meantime, a number of studies for calculating formaldehyde generation from construction materials are often those determining a specific quantity of generation in a stationary state, while few studies are the observation of time series variation from immediately after the exposure into the chamber. Accordingly, the subject studies used lauan plywood as the samples and examined the method of calculating the change with lapse of time of the formaldehyde ...
Horizontal steam generators are typical parts of nuclear power plants with pressure water reactor type VVER. By means of this computer program, a detailed thermal-hydraulic study of the horizontal steam generator PGV-1000 has been carried out and a special attention has been paid to the thermal-hydraulics of the secondary side. A set of important steam generator characteristics has been obtained and analyzed. Some of the interesting results of the analysis are presented in the paper. (author)
The principal types of corrosion are presented which can occur in CANDU steam generator. There are also presented the operation conditions, the specifications referring to the water chemistry and the construction materials of Steam Generator, the factors that have a great influence on the corrosion behaviour during the whole exploitation period of this equipment. The most important elements of CANDU Steam Generator ageing management program are also discussed. (R. P.)
A survey was conducted of experience with steam generator tubes at nuclear power stations during 1976. Failures were reported at 25 out of 68 water-cooled reactors. The causes of these failures and the repair and inspection procedures designed to cope with them are summarized. Examination of the data indicates that corrosion was the major cause of steam generator tube failures. Improvements are needed in steam generator design, condenser integrity and secondary water chemistry control. (author).
The presentation deals with the flows on the primary side of a horizontal steam generator under conditions typical to natural circulation cooling of the reactor. The main goal is to analyse the effect of primary flow patterns on the heat transfer capability of the steam generator. Conclusions pertinent to steam generator modelling with system codes are also drawn. (10 refs., 9 figs., 4 tabs.).
The presentation deals with the flows on the primary side of a horizontal steam generator under conditions typical to natural circulation cooling of the reactor. The main goal is to analyse the effect of primary flow patterns on the heat transfer capability of the steam generator. Conclusions pertinent to steam generator modelling with system codes are also drawn. (10 refs., 9 figs., 4 tabs.).
Peculiarities of design of the PGV-1000 horizontal steam generator affecting soluble impurity distribution in its water volume are considered in brief. The results of estimating sodium distribution in different zones of the steam generator are presented. The conclusion is made on the necessity of arrangement of representative measurements of sodium and chloride content in water volume of the steam generator, particularly, in the hot bottom zone for optimization of blow-through flowsheet and its regulations.
Results are given of numerical simulation of three-dimensional pattern of flow of a two-phase steam-water mixture in the house of a PGV-1000 horizontal steam generator obtained using the BAGIRA best-estimate thermohydrodynamic computer codes. The space distributions of velocities and local void fractions in the steam generator housing for different modes of operation of power-generating unit are calculated and compared with available experimental data.
Results are given of numerical simulation of three-dimensional pattern of flow of a two-phase steam-water mixture in the house of a PGV-1000 horizontal steam generator obtained using the BAGIRA best-estimate thermohydrodynamic computer codes. The space distributions of velocities and local void fractions in the steam generator housing for different modes of operation of power-generating unit are calculated and compared with available experimental data.
... Three prototype reactors were constructed and the photocatalysts used were TiO2 for hydroxyl radical generation, dyes such as methylene blue and rose bengal for singlet oxygen generation, and ferric chloride/hydrogen peroxide in Photo-Fenton OH radical generation. Singlet oxygen was effective against some of the pesticides but reacted slowly or not at all with others. All pesticides were degraded by OH radical generating agents (such as methylene blue)...
This paper will describe the application of power generation by the use of microturbine technology by Capstone Turbine Corporation throughout South America. The purpose of this paper is to describe the technology and the experience gained over the last six years. The microturbines are power generation systems that produce energy from a diverse range of liquid or gaseous fuels. The generator is driven by a small gas turbine with a common shaft for the rotors of the generator and the engine. (author)
Superconducting generators for high power applications have been of interest for a number of years. Superconducting generators using low temperature superconductors (LTS) have been manufactured to produce up to 20 MW of electrical power and have been configured in either synchronous alternators which have an AC output that may be subsequently rectified to produce DC and homopolar generators which produce low voltage DC. Typically these generators require scrupulous attention to vacuum integrity for cryogenic insulation at 4.2K and tend to be somewhat fragile because of extensive thermal and magnetic shields that are not required in conventional power generators. Recently, high purity aluminum composites have been developed for a high power AC generator that is cooled by cryogenic hydrogen at 21K. This aluminum generator is very compact and ...
The objective of this study was to identify and assess the present and future dimensions of environmental effects and impacts of various energy generation alternatives, and to place safety and environmental risks associated with the nuclear industry in Canada in perspective with the risks from other sources. It was found that nuclear power generation involves a comparable risk to that of conventional methods of thermoelectric power generation.
This paper deals with dynamic study of co-generator system with derived dynamic models of generator, excitation system, and turbine/governor from field tests. Mainly this study concentrates on frequency control by under-frequency relay. We simulates dynamic study of co-generator system using EMTDC. (author). 4 refs., 13 figs., 4 tabs.
Implementation of a plan to charge waste management costs to the facility that generates such waste requires a long-term commitment and consistent administration. The benefit is that generators are provided the incentive to optimize waste management practices if the charges are appropriately applied. This paper summarizes (1) a plan to charge waste generators, (2) the administrative structure of the plan, (3) a comparison between the rate structure and changes in waste disposal operations, and (4) issues that have surfaced as the plan is implemented. 2 refs., 1 fig., 1 tab.
Ways of improving the water chemistry used in the turbine generator stator?s cooling systems at Russian nuclear power plants are considered. Data obtained from operational chemical monitoring of indicators characterizing the quality of cooling water in the turbine generator stator cooling systems of operating power units at nuclear power plants are presented.
The paper analyses the advantages and disadvantages of the second generation improved technologies and third generation technologies mainly developed in China in terms of safety and economy. The paper also discusses the maturity of the second generation improved technologies and the sophistication of the third generation technologies respectively. Meanwhile, the paper proposes that the advantage and disadvantage of second generation improved technologies and third generation technologies should be carefully taken into consideration and the relationship between the maturity and sophistication should be properly dealt with in the current stage. A two-step strategy shall be taken as a solution to solve the problem of insufficient capacity of nuclear power, trace and develop the third generation technologies, so as to ensure the sound and fast ...
The Steam Generator (SG) tubing degradation caused by corrosion and other age-related mechanisms continues to be a significant safety and cost concern for many Nuclear Power Plants (NPP). The understanding of the steam generator ageing mechanisms is the key to effective management of steam generator ageing and consists of the knowledge of steam generator materials and these one properties, stressors and operating conditions, like degradation sites and wear mechanisms. The principal types of corrosion are presented which can occur in CANDU steam generator. There are also presented the operation conditions, the specifications referring to the water chemistry and the construction materials of Steam Generator, the factors that have a great influence on the corrosion behaviour during the whole exploitation period of this equipment. (R.P.)
The steam generator is a very important component of a nuclear power plant. Historically, vertical steam generators came to be used abroad and horizontal steam generators in our country. Both types of steam generators operate successfully in nuclear power plants and satisfactorily fulfill their functions, enabling the production of electricity. Repeated attempts to re-examine the existing concepts in one or another country have been unsuccessful because there are no convincing arguments for this. Nonetheless, the question of using a different type of steam generator is raised periodically in our country and abroad. This article briefly reviews different concepts of steam generators. Their parameters, characteristics, and thermal efficiency are compared and ways to increase the latter are a...
This article describes the project for the installation of an additional emergency diesel generator in both Asco and Vandellos NPPs. The basic objectives of this project are to improve the availability of the emergency generation system, in order to provide greater ability to address potential contingencies, and also to increase the flexibility of the preventive periodic maintenance of the emergency diesel generators. This maintenance, that is currently a milestone of the critical path of the refueling outage, will be performed on-line. The new diesel generator will be sized to support all the loads considered in the safety case and also the consumption of its own auxiliary systems, and will be tested for operability assessment on the same periodical basis than the existing ones. The solution adopted will also permit that the N diesel generator may be connected to any bus bar class ...
In the current wind turbine generation system, there are substantial problems such as the maximum power of the wind turbine cannot be obtained under the fluctuating wind speed, high in cost and low in annual net electricity production (due to mismatch between a generator and a wind turbine). A new wind turbine generator optimized for the wind turbine output is presented in order to solve such problems. This wind turbine generator consists of a permanent magnet generator, a reactor and a rectifier, and uses neither a control circuit which requires standby electricity nor a PWM converter having a switching element. By selecting most appropriate combination of the permanent magnet generator having multiple windings and the reactor connected in series with each winding, the maximum output of the wind turbine can be obtained without using a control circuit. The new ...
The Stefan problem involving a source term is considered in this technical note. As an example, planar solidification with time-dependent heat generation in a semi-infinite plane is solved by use of a perturbation technique. The perturbation solution is validated by reducing the problem to the case without heat generation whose exact solution is available. An application to the case with constant heat generation is presented, for which a closed-form solution is obtained. The effects of heat generation and Stefan number on the evolution of solidification are examined using the perturbation solution.
A method of detecting explosives in a vehicle includes providing a first rack on one side of the vehicle, the rack including a neutron generator and a plurality of gamma ray detectors; providing a second rack on another side of the vehicle, the second rack including a neutron generator and a plurality of gamma ray detectors; providing a control system, remote from the first and second racks, coupled to the neutron generators and gamma ray detectors; using the control system, causing the neutron generators to generate neutrons; and performing gamma ray spectroscopy on spectra read by the gamma ray detectors to look for a signature indicative of presence of an explosive. Various apparatus and other methods are also provided.
Purpose: In a case of automatically controlling the water level at the time of generating a lower power, to impact the followability of the control necessary for the power variation of the steam generator thereby to obtain good controllability. Constitution: A signal of deviation of water level of a steam generator and its set value and a signal of a difference between the temperature of the primary coolant in the high temperature side pipeline and that of the primary coolant in the low temperature side pipeline are used to automatically or manually control the flow quantity of water fed to the steam generator. (Yoshihara, H.).
A method of detecting explosives in a vehicle includes providing a first rack on one side of the vehicle, the rack including a neutron generator and a plurality of gamma ray detectors; providing a second rack on another side of the vehicle, the second rack including a neutron generator and a plurality of gamma ray detectors; providing a control system, remote from the first and second racks, coupled to the neutron generators and gamma ray detectors; using the control system, causing the neutron generators to generate neutrons; and performing gamma ray spectroscopy on spectra read by the gamma ray detectors to look for a signature indicative of presence of an explosive. Various apparatus and other methods are also provided.
This paper extends the analytical procedure described in another paper in these proceedings to analyze a variety of compact and light-weight OSC-designed radioisotope-heated generators. Those generators employed General Purpose Heat Source (GPHS) modules and a converter containing sixteen AMTEC cells of OSC`s revised five-tube design with enhanced cell wall reflectivity described in a companion paper in these proceedings. OSC found that the performance of the generator is primarily a function of the thermal insulation between the outside of the generator`s 16 cells and the inside of its wall. After examining a variety of insulation options, it was found that the generator`s performance is optimized by employing a hybrid insulation system, in which the space between the cells is filled with fibrous Min-K insulation, and the generator walls are lined with tapered ...
Current light water reactor (LWR) steam generators have been affected by a variety of corrosion and mechanical damage degradation mechanisms. Included are wear caused by tube vibration, intergranular corrosion, pitting, and thinning or wastage of the steam generator tubing and accelerated corrosion of carbon steel supports (denting). The Electric Power Research Institute (EPRI) and the Steam Generator Owners Groups (I, II) have sponsored laboratory and field studies to provide ameliorative actions for the majority of the damage forms experienced to date. Some of the current corrosion mechanisms are aggravated or caused by unique materials choices or materials interactions. New materials have been proposed and at least partially qualified for use in replacement model steam generators, including an advanced LWR design. In so far as possible, the materials choices for the advanced LWR steam ...
The 3D modeling of the thermal hydraulic processes and soluble impurity distribution in the horizontal steam generator PGV-1000 was fulfilled with the thermal hydraulic code STEG. Steady-state operation of horizontal seam generator PGV-1000 was analyzed at nominal power. The modeling of the soluble impurity distribution was fulfilled on the basis of the previous thermal hydraulic modeling results. The processes of the soluble impurity deposition on the steam generator tube bundles and deposits outwash were considered in the mathematical model of the code. The modeling was fulfilled for horizontal steam generators with different peculiarities in construction. Calculation results were compared with experimental results obtained at NPP. The agreement between calculated and experimental results is quite reasonable. Results of modeling are sensible to the peculiarities of the horizontal steam ...
A method and system for enhancing the transient stability of an intertied three-phase electric power generating system. A set of power exporting generators (10) is connected to a set of power importing generators (20). When a transient cannot be controlled by conventional stability controls, and imminent loss of synchronism is detected (such as when the equivalent rotor angle difference between the two generator sets exceeds a predetermined value, such as 150 degrees), the intertie is disconnected by circuit breakers. Then a switch (30) having a 120-degree phase rotation, or a circuit breaker having a 120-degree phase rotation is placed in the intertie. The intertie is then reconnected. This results in a 120-degree reduction in the equivalent rotor angle difference between the two generator sets, making the system more stable and allowing more time for the conventional controls to ...
In an ignition timing control apparatus for controlling the ignition timing of each cylinder in order to reduce knock generation in a multi-cylinder engine, a lag-angle correction is made for the ignition timing of a cylinder in which a knock is generated and at the same time, a slight lag-angle correction is made for the ignition timing of the other cylinders in which no knock is generated. When the operating condition of engine is rapidly changed for example, under the condition in which knock is liable to occur in all cylinders as at rapid acceleration time, a lag-angle correction is made by the same amount as in the knock generating cylinder, for the ignition timing of cylinders in which no knock is generated. When no knock is generated for a predetermined time, a lead-angle correction is made for the ignition timing subjected to the lag-angle correction of ...
The Institute of Energetic and Nuclear Research - IPEN is a research and development institution, located in a densely populated area, in the city of Sao Paulo. The nuclear fuel cycle was developed from the Yellow Cake to the enrichment and reconversion at IPEN. After this phase, all the technology was transferred to private enterprises and to the Brazilian Navy (CTM/SP). Some plants of the fuel cycle were at semi-industrial level, with a production over 20 kg/h. As a research institute, IPEN accomplished its function of the fuel cycle, developing and transferring technology. With the necessity of space for the implementation of new projects, the uranium hexafluoride (UF{sub 6}) production plant was chosen, since it had been idle for many years and presented potential leaking risks, which could cause environmental aggression and serious accidents. This plant decommission required accurate planning, as this work had not been carried out in Brazil before, for this ...
Statements about the dynamic processes of uptake, transport, and deposition of Ca and Mg in norway spruce and Scots pine are made in this paper. Concerning the storage of these elements it is shown that there are great differences in their functional importance in cell metabolism. There is evidence that the role of Mg in enzyme and protein metabolism is of far greater significance for the understanding of Mg-deficiency symptoms than its function as the central atom of the chlorophyll complexes. In regard to the transport and especially to the incorporation of Ca into the needles differences between species were evident, expressing the special status of pine among the gymnosperms. With increasing needle age an accumulation of Ca-oxalate crystals, which are physiologically inert, could be proved for the studied conifers. This was interpreted as a 'detoxication' from surplus Ca to hold constant the level of the physiologically active fraction. Accordingly, the low Ca-contents of ...
This work is concerned with the development and application of ion implantation techniques for improving the corrosion resistance of zircaloy-4. The corrosion resistance in nitrogen implanted zircaloy-4 under a 120 keV nitrogen ion beam at an ion dose of 3 x 10"1"7 cm"-"2 depends on the implantation temperature. The characteristics of surface oxidation and corrosion resistance were analyzed with the change of implantation temperature. It is shown that as implantation temperature rises from 100 to 724 C, the colour of specimen surface changes from its original colour to light yellow at 100 C, golden at 175 C, pink at 300 C, blue at 440 C and dark blue at 550 C. As the implantation temperature goes above 640 C, the colour of surface changes to light black, and the surface becomes a little rough. The corrosion resistance of zircaloy-4 implanted with nitrogen is sensitive to the implantation temperature. The pitting potential of specimens increases from 176 to 900 mV ...
Calcium-activated chloride channels (CaCCs) are widely expressed in mammalian tissues, including intestinal epithelia, where they facilitate fluid secretion. Potent, selective CaCC inhibitors have not been available. We established a high-throughput screen for identification of inhibitors of a human intestinal CaCC based on inhibition of ATP/carbachol-stimulated iodide influx in HT-29 cells after lentiviral infection with the yellow fluorescent halide-sensing protein YFP-H148Q/I152L. Screening of 50,000 diverse, drug-like compounds yielded six classes of putative CaCC inhibitors, two of which, 3-acyl-2-aminothiophenes and 5-aryl-2-aminothiazoles, inhibited by >95% iodide influx in HT-29 cells in response to multiple calcium-elevating agonists, including thapsigargin, without inhibition of calcium elevation, calcium-calmodulin kinase II activation, or cystic fibrosis transmembrane conductance regulator chloride channels. These compounds also inhibited ...
Poly(methyl methacrylate), PMMA, Acrigel, a Brazilian polymer, is used in the manufacture of medical supplies sterilisable by ionizing radiation. However, when PMMA is gamma-irradiated it undergoes main chain scissions, which promote molecular degradation causing reduction in its physical properties. Therefore, radiolytic stabilization of PMMA is important for to become it commercially radio sterilisable. In this work we investigated the radiolytic stabilization of PMMA by using HALS (Hindered Amine Light Stabilizer) additive, commercially used for photo and thermo oxidative stabilization of polymers. The investigation of the radiation-induced main chain scissions was carried out by viscometric method. The additive added to the polymer system at 0.3 % w/w promotes a molecular radioprotection of 61%. That means a reduction of G value (scissions/100 eV) from 2.6 to 1.0. In addition, the glassy transition temperature (Tg) of PMMA (no additive), significantly changed by radiation, does not ...
The decision of the United Kingdom to adopt a policy of solidification of high level waste had led to renewed interest in vitrification. The HARVEST process chosen is an adaptation of the FINGAL concept developed at Harwell 15 years ago. Because of certain changes in engineering design and differences in the composition of the waste, additional chemical engineering data are required for HARVEST. The new inactive pilot plant has been built to provide this information. Its size is virtually full-scale and batches of glass up to 1 tonne can be manufactured in vessels of diameter up to 750mm. Five glass-making runs have been carried out. Attention has concentrated on the performance of the off-gas system which employs wet methods. Carry-over of solids occurs, primarily as a result of physical entrainment. The carry-over of synthetic fission products is improved from 2.5 to 0.1% by directing the feed down the vessel walls. Most of the entrained solids is caught in the condensate which gives ...
The objective of this research is to study the effects of elevated ozone, carbon dioxide and their combination on ultrastructural, physiological and biochemical responses of Scots pine needles and how these effects are reflected to photosynthesis, carbohydrate and nutrient allocation and finally to shoot and root growth of trees. In addition the interactions of the studied trees and mycorrhizal fungi as well as insect herbivores are studied. The exposures have been running only for two growing periods and it seems necessary to continue the experiment over the third growing season in 1996. Since the analyses are partially incomplete, only preliminary conclusions are possible at the moment. The slightly increased shoot growth and needle width and increased amount of starch in chloroplasts point to the slight stimulating effect of elevated CO{sub 2} among the chamber treatments. Altogether the growth of the seedlings was best in the chamberless treatment indicating a negative chamber ...
This paper discusses a new type of supramolecular material tris{5-N-[3-(9H-carbazol-9-yl)propyl]-N-(4-methylphenyl) aminesulfonyl-8-hydroxyquinolato} aluminum(III), Al(SCarq)3, which we synthesized using three 5-N-[3-(9H-carbazol-9-yl)propyl]-N-(4-methylphenyl) aminesulfonyl-8-hydroxyquinoline as bidentate ligands. The peak photoluminescence in the solid phase appears at 488 nm. In cyclic voltammetric measurement, two oxidation peaks, which were obtained at -5.6 and -5.9 eV, correspond to HOMO sites of carbazoyl and aluminum quinolates, respectively. In the investigation of solid morphological thin film, the flat surface was investigated using an atomic force microscope. The root mean square (rms) and mean roughness (Ra) were respectively measured to be 0.427 and 0.343 nm. For the fabrication of organic light-emitting devices (OLEDs) using spin-coating techniques, the turn-on voltage and maximum luminescence of the optimized electroluminescence device, glass/ITO (20 nm)/PEDOT:PSS (75 ...
The coupling between cerebral metabolic rate of oxygen (CMRO2) and blood flow (CBF) in response to visual stimulation was evaluated by means of a model of oxygen delivery. The model predicted a nonlinear relationship between stimulus-evoked changes of oxygen consumption and blood flow. The magnitude of the CMRO2/CBF ratio index (IO2) was used to indicate the degree of flow-metabolism coupling prevailing in specific areas of the brain during physiological stimulation. Therefore, the index provided a measure of the blood oxygenation level dependent (BOLD) magnetic resonance contrast. To evaluate the changes of IO2 in response to visual stimulation, the model was applied to the effect of a changing flicker rate of a visual stimulus on the magnitudes of CBF, CMRO2, and oxygen diffusion capacity, in the human brain. Positron emission tomography (PET) was used to measure the CBF and the CMRO2 in 12 healthy volunteers who viewed a cross-hair (baseline) or a yellow-blue ...
In Japan, the Ningyo-toge uranium deposit was discovered in 1955, and the Tono deposit in 1962. Geology of these mines is different from that of other metal mines developed in Japan. Therefore, it appeared that some changes were required in the usual mining methods applied to existing metal mines to mine uranium ore in these deposits. At the Ningyo-toge mine, effective methods were studied for mining the ore, such as the room and pillar method, long-wall method, slicing method, and the hydraulic method; as a result, it was determined that a modified long-wall method is the most useful and practicable for recovering uranium ore from this underground sedimentary deposit. Applicatons of in-place and microbiological leaching to these deposits are being studied to secure mine safety and decrease mine pollution. Since 1959, when the Ningyo-toge mine went into operation, no hazards for workers nor any pollution of the environment were permitted. Research and development on uranium processing ...
Detecting a camouflaged target in a visually noisy background depends on the ability of the observer to discriminate the target from the surrounding terrain. Visible laser irradiation at less than damage levels can act as a masking source by compromising or reducing the observer's ability to resolve differences in the visual scene. Previous research has examined this concept by investigating laser flash effects on: acuity (size discrimination); tracking (motion discrimination); visual sensitivity (color); and contrast sensitivity functions (luminance contrast). In all cases, flashes from continuous-wave (CW) sources have proven more effective visually than pulsed (Q-switched) sources, when compared on peak-energy criteria (i.e., MPE), even though Q-switched lasers induce damage at lower energy doses. Additionally, the inherent safety of ultra-short laser pulses has been questioned. Past animal research has shown that, on the measures of acuity, sensitivity, tracking, and ...
A new high-sensitivity wide-bandwidth 1.25-5.5 eV (225-1000 nm) spectrometer has been constructed to measure luminescence emission spectra of minerals that are of interest for optical dating. Spectra of emission resulting from 1.43 eV (IR) excitation after #gamma#-irradiation are reported for 13 cut rock feldspars and 20 feldspar separates. Also reported are phosphorescence spectra following #gamma#-irradiation, and after 1.4 eV excitation. The main differences between the infrared stimulated luminescence spectra and the phosphorescence is the almost complete absence of the violet, 3.1 eV, and yellow-green, 2.2 eV, bands in the phosphorescence, and the presence of a green emission band centred at 2.7 eV in the phosphorescence following #gamma#-irradiation (but absent in the phosphorescence following 1.4 eV excitation). The red, 1.7 eV, band is present in all the phosphorescence spectra but is not always seen during 1.4 eV excitation. A band at #approx# 1.3 eV is ...
Anionic complexes of transition metals were stabilized in aqueous solutions containing high concentrations of various short-chain quaternary ammonium salts. Compounds with longer paraffin chains were effective in much less concentrated solution. Complex ions were detected spectrophotometrically. FeCl/sub 4//sup -/, which is usually formed in concentrated HCl, was the predominant Fe(III) complex in 30 m choline chloride containing only 0.12 M HCl. A yellow transitory Tc(VII) chloro-addition intermediate, formed in the reduction of TcO/sub 4//sup -/ by concentrated HCl, was stabilized when the solution also contained 25 m choline chloride. Its spectrum, as well as the isolation of an already known Tc(VII) bipyridyl complex, is reported. Concentrated organic electrolytes also stabilized Tc(V) oxide halides against disproportionation and Tc(IV) hexahalides against hydrolysis. Halochromates of Cr(VI) were formed and stabilized in dilute acid containing quaternary ...
The authors present electric-field dependent electroreflectance and photocurrent spectra of visible-bandgap In{sub x}(Al{sub y}Ga{sub 1{minus}y}){sub 1{minus}x}P/In{sub x{prime}}(Al{sub y{prime}}Ga{sub 1{minus}y{prime}}){sub 1{minus}x{prime}}P multiple-quantum-well (MQW) structures. These structures, grown by metal-organic vapor phase epitaxy on 6{degrees}-misoriented (100) GaAs substrates, have undoped MQWs sandwiched between doped In{sub 0.5}Al{sub 0.5}P layers, forming p-i-n diodes. Quantum-well compositions in the range 0.46{le}x{le}0.52 and 0{le}y{le}0.4, corresponding to bandgaps in the red to yellow-green range, were used. The Stark shifts in these various samples were measured and found to depend on the details of the Mg p-type doping profile, confirming important diffusion effects, in agreement with secondary ion mass spectrometry and capacitance-voltage data. The results show that these new materials are promising for visible-wavelength optical modulator ...
Water model experiments were conducted to develop a two-stage stirring method for obtaining higher yields and a more uniform distribution of graphite particles in copper alloys. This was followed by several melts for synthesis of copper-graphite alloys in which Ti was used as a wetting agent to improve the wettability of graphite in the copper melt. In the first stage, a vortex method was employed to facilitate the addition of graphite particles into the copper melt. In the second stage, a specially designed stirrer was used for uniform particle distribution while avoiding the formation of vortex in the melt. The two-stage stirring was found to considerably improve the recovery of graphite, over those obtained with the prior practice of single-stage stirring and resulting in a more uniform particle distribution. In addition, graphite recoveries increased with increasing Ti content in the range investigated. Floatation, fluidity, and directional solidification experiments were also ...
Outcrops of Tertiary coal-bearing units in sea cliffs of the Kenai Peninsula provide an excellent study area for volcanic ash partings in coals. Twenty mid-to late-Miocene, 50-cm to 3-m thick coal seams exposed in the sea cliffs about 10 km west of Homer contain an average of 10 volcanic ash or lapilli tuff partings each. The bedding relationships of the coal with any one parting cannot be predicted, and the contacts of the partings with the coal range from very sharp to predominantly gradational. These bedding relationships provide clues about the surface on which the ashes fell and on which the coal was accumulating. For example, some ashes fell in standing water, others on irregular subaerial surfaces. The partings are in various stages of alteration to kaolinite and bentonite, and vary in thickness from a few millimeters to about 10 cm. The consistency and texture of the partings depend on the degree of alteration; the less altered partings display visible pumice fragments and ...
We report a whole-genome shotgun assembly (called WGSA) of the human genome generated at Celera in 2001. The Celera-generated shotgun data set consisted of 27 million sequencing reads organized in pairs...Full Text Available
This 2-page fact sheet gives statistics on routine waste generation and projected reduction by waste type, and 1994 pollution prevention and recycling accomplishments at ORNL.
A novel soft commutated direct current (DC) motor is introduced. The current of the commutated coil is intentionally drained before the brush disconnects the coil. This prevents the spark generation that normally occurs in conventional DC motors. A similar principle can be applied for DC generators.
This 1978 annual report contains the results of ''Seismic testing of Wolsung-1 steam generator model'' which was initiated in 1977 as a part of a study on nuclear components testing. Model 78, improved version of Model 77 which did not take into account f...
The Second International Seminar on Horizontal Steam Generator Modelling was arranged to continue the international cooperation that was started during the first seminar in March 1991. The main topics of the seminar were: (1) further experimental results ...
Prospects for using new structural materials instead of Grade 08Kh18N10T steel for making heat-transfer tubes for horizontal steam generators with the purpose to increase their service life from 30?40 to 60 or more years are considered.
Processes and apparatus are disclosed for generation of radioisotope contaminant fission fragment free ozone from oxygen containing streams by chemonuclear irradiation accomplished by passing the stream past high energy radiation sources placed in sealed chambers.
This report discusses the following topics on superconductivity: nonlinearities in hard superconductors such as surface impedance of a type II superconductimg half space and harmonic generation and intermodulation due to alternating transport currents; and nonlinearities in superconducting weak links such as harmonic generation by a long Josephson Junction in a superconducting slab.
A model was developed to compute concentration of impurities in the WWER 440 steam generator (SG) secondary water along the tube bundle. Calculated values were verified by concentration values obtained from secondary water sample chemical analysis. (orig.). 2 refs.
A submerged nuclear power station has been proposed as an alternative power station with a relatively low environmental impact for use by both industrialized and developing countries. The station would be placed 10 m above the seabed at a depth of 30--100 m and a distance of 10--30 km from shore. The submerged nuclear power station would be manufactured and refueled in a central facility, thus gaining the economies of factoryfabrication and the flexibility of short-lead-time deployment. To minimize the size of the submerged hull, horizontal steam generators are proposed for the primary-to-secondary heat transfer, instead of the more traditional vertical steam generators. The horizontal steam generators for SNPS would be similar in design to the horizontal steam generators used in the N-Reactors except the tube orientation is horizontal (the tube's inlet and outlet connection points on the ...
A submerged nuclear power station has been proposed as an alternative power station with a relatively low environmental impact for use by both industrialized and developing countries. The station would be placed 10 m above the seabed at a depth of 30--100 m and a distance of 10--30 km from shore. The submerged nuclear power station would be manufactured and refueled in a central facility, thus gaining the economies of factoryfabrication and the flexibility of short-lead-time deployment. To minimize the size of the submerged hull, horizontal steam generators are proposed for the primary-to-secondary heat transfer, instead of the more traditional vertical steam generators. The horizontal steam generators for SNPS would be similar in design to the horizontal steam generators used in the N-Reactors except the tube orientation is horizontal (the tube`s inlet and outlet connection points on the tubesheet are ...
A submerged nuclear power station has been proposed as an alternative power station with a relatively low environmental impact for use by both industrialized and developing countries. The station would be placed 10 m above the seabed at a depth of 30--100 m and a distance of 10--30 km from shore. The submerged nuclear power station would be manufactured and refueled in a central facility, thus gaining the economies of factoryfabrication and the flexibility of short-lead-time deployment. To minimize the size of the submerged hull, horizontal steam generators are proposed for the primary-to-secondary heat transfer, instead of the more traditional vertical steam generators. The horizontal steam generators for SNPS would be similar in design to the horizontal steam generators used in the N-Reactors except the tube orientation is horizontal (the tube's inlet and outlet connection points on the tubesheet are ...
In this paper the authors show the means putting in place for examination of steam generators tubes. These means (eddy current probes, ultrasonic testing) associated with a knowledge on degradation phenomena allow mapping controlled tubes and limiting undesirable obturations.
An understanding of the mechanism of generation of Lg from underground nuclear explosions is essential for seismic monitoring and source discrimination. Near-source scattering of explosion-generated Rg into S appears to be responsible for the low-frequenc...
Main results of the 40-year experience gained from operation of horizontal steam generators in VVER-type reactor installations used in Russia and many foreign countries are described. Existing unresolved problems are pointed out.
Lactobacillus buchneri ST2A vigorously decarboxylates histidine to the biogenic amine histamine, which is excreted into the medium. Cells grown in the presence of histidine generate both a transmembrane...Full Text Available
PsychoPy is a software library written in Python, using OpenGL to generate very precise visual stimuli on standard personal computers. It is designed to allow the construction of as wide a variety of...Full Text Available
Drosophila neuroblasts divide asymmetrically by aligning their mitotic spindle with cortical cell polarity to generate distinct sibling cell types. Neuroblasts asymmetrically localize...Full Text Available
Electrical power is generated by steam turbines (steam being produced by coal, oil, gas or nuclear reactors), hydro units, gas turbines, internal combustion engines, jet engines, and pumped storage plants. Nuclear Power Plants generate only 15% of the total electrical power in the US. Nuclear Power Plants being cheaper to run are generally base loaded. The pumped-storage and gas turbine plants have ideal characteristics for peaking duty. In the pumping mode, pumped storage plants are used to provide additional system load and in the generating mode, they supply reactive power during peak load demands. Gas turbine plants have higher running costs, but are used as peaking units with a fast start capability. Fossil power plants need a minimum of 1 hour to stabilize expansion in the boiler and turbine generator. Due to a more competitive power supply market due to deregulation, most of the utilizes plan ...
BackgroundOur motor actions normally generate sensory events, but how do we know which events were self generated and which have external causes? Here we use temporal adaptation...Full Text Available
Generation of replicative defective viruses is frequently observed during viral infections. We now report that encapsidation and reverse transcription of spliced viral RNA is an additional mechanism...Full Text Available
In the study three loss-of-feedwater type experiments which were preformed with the PACTEL facility has been calculated with two computer codes. The purpose of the experiments was to gain information about the behaviour of horizontal steam generator in a ...
This report discusses the work done on EPRI program S149-1. In this program the feasibility of cleaning steam generators off line with organic chelants as a means of arresting denting corrosion was investigated. The rationale behind this program is to mak...
Steam generator tube plugging rates have increased markedly at Bruce since the end of the 1980s. A new programme of refurbishment aims to keep the steam generators operating successfully until around 2015. (Author).
Steam generator tube plugging rates have increased markedly at Bruce since the end of the 1980s. A new programme of refurbishment aims to keep the steam generators operating successfully until around 2015. (Author).
Increased production of reactive oxygen species (ROS) in mitochondria underlies major systemic diseases, and this clinical problem stimulates a great scientific interest in the mechanism of ROS generation....Full Text Available
In this paper, we report on the analysis of reverse flow in inverted U-tubes of a steam generator under natural circulation condition. The mechanism of reverse flow in inverted U-tubes of the steam generator with natural circulation is graphically analyzed by using the full-range characteristic curve of parallel U-tubes. The mathematical model and numerical calculation method for analyzing the reverse flow in inverted U-tubes of the steam generator with natural circulation have been developed. The reverse flow in an inverted U-tube steam generator of a simulated pressurized water reactor with natural circulation in analyzed. Through the calculation, the mass flow rates of normal and reverse flows in individual U-tubes are obtained. The predicted sharp drop of the fluid temperature in the inlet plenum of the steam generator due to reverse flow agrees very well with the experimental ...
The lateral bearing device is made of 7 lateral supports, each positioned to allow the displacement of the steam generator due to thermal or seismic effects. Each support includes a buffer plate that can be positioned on the steam generator using a position control assembly. This control assembly consists of a screw jack arrangement where the nut is fastened via an energy absorbing layer to a footplate that is fixed to the concrete wall of the steam generator enclosure. 4 figs.
We present the results obtained from tests and studies carried out on the model of tube bundles for a PGV-1000 horizontal steam generator that were conducted for experimentally substantiating the design service life of a steam generator tube bundle intended for use at new nuclear power stations equipped with a PGV-1000MKP steam generator. Measures taken to minimize the incipience and development of local corrosion damage to the heat-transfer tubes and ensure their design service life are substantiated and confirmed.
We consider the impact of a 4th generation on Higgs to $\\gamma\\gamma$ and $WW,ZZ$ signals and demonstrate that the Tevatron and LHC have essentially eliminated the possibility of a 4th generation if the Higgs is SM-like and has mass below 200 GeV. We also show that the absence of enhanced Higgs signals in current data sets in the $\\gamma\\gamma$ and $WW,ZZ$ final states can strongly constrain (almost eliminate) the possibility of a 4th generation in two-Higgs-doublet models of type II (in the MSSM).
A method for cleaning timing optimization in a parallel steam generator system is described. The method is based on the minimization of a suitable objective function, and takes into account the load allocation on steam generators. In order to establish appropriate fouling growth models the mechanism of the particle deposition and removal on heat transfer surfaces is analyzed. The objective function is related to the short time management costs which are based on depreciation of steam generators, fuel costs and the costs of cleaning interventions. The optimization problem is described; a direct one level method is compared with a two level method. Some applications and their results are reported and discussed. (author)
An electric power generating apparatus is described, including: a solar collector; a primary thermal loop including primary thermal fluid; a cavity receiver to receive reflected solar energy from the solar reflector, convert the solar energy into thermal energy, and transmit the thermal energy to the primary thermal fluid by heating the primary thermal fluid not to exceed a given temperature, the given temperature being substantially equal to 700 F; a Stirling engine receiving the primary thermal fluid heated by the cavity receiver, including means to generate mechanical power and means to generate electrical power from the means to generate mechanical power.
Low cycle fatigue (LCF) of a fourth-generation single-crystal (SC) Ni-base superalloy TMS-138 was studied by comparison with a typical third-generation (TMS-75) and a second-generation (CMSX-4) Ni-base SC superalloys. TMS-138 exhibits improved LCF behaviour under a condition of the R ratio of 0 at temperatures of 1073 K and 1173 K. The addition of refractory elements resulted in a remarkable improvement of the LCF properties compared to those of the reference superalloys due to the different microstructure developed in TMS-138. (orig.)
The general objective of the International Seminars of Horizontal Steam Generator Modelling has been the improvement in understanding of realistic thermal hydraulic behaviour of the generators when performing safety analyses for VVER reactors. The main topics presented in the fourth seminar were: thermal hydraulic experiments and analyses, primary collector integrity, feedwater distributor replacement, management of primary-to-secondary leakage accidents and new developments in the VVER safety technology. The number of participants, representing designers and manufacturers of the horizontal steam generators, plant operators, engineering companies, research organizations, universities and regulatory authorities, was 70 from 10 countries.
... in the design of such devices as fusion reactors, magnetohydrodynamic generators, magnetically levitated vehicles, magnetic forming devices, and ...
This invention relates to new phosphor materials and to combinatorial methods of synthesizing and detecting the same. In addition, methods of using phosphors to generate luminescence are also disclosed.
... nent to the design and construction of metal-semiconductor solar cells, in that both the photovoltage and the efficiency of metal-semiconductor cells ...
The water and steam circuits of steam generators in pressurized-water nuclear power plants are described together with the mechanism of denting, and the corrosion of spacer plates that leads to cracks in tubes by constriction. The different chemical specifications applicable to the water of the secondary circuit of the generators in normal operation and on first commissioning are listed. The results obtained and the measurements of chemical values taken in operation on the water in the secondary circuits of steam generators at Fessenheim and Bugey are presented.
The water and steam circuits of steam generators in pressurized-water nuclear power plants are described together with the mechanism of denting, and the corrosion of spacer plates that leads to cracks in tubes by constriction. The different chemical specifications applicable to the water of the secondary circuit of the generators in normal operation and on first commissioning are listed. The results obtained and the measurements of chemical values taken in operation on the water in the secondary circuits of steam generators at Fessenheim and Bugey are presented.
In this article, the results of low-current gas-discharge plasma generator investigations carried out by a group of scientists from the Kazan' Aviation Institute are presented. When considered necessary, the results are compared with the data obtained by other authors. The basic configurations and theoretical calculation peculiarities of plasma generators are described. The electrical, thermal and energy characteristics of discharges in gas flows, as well as summarised empirical formulae and experimental data necessary for calculations and design of plasma devices are presented. (author)
Design considerations are given for the secondary side region of a vertical U-tube nuclear stream generator with an integral preheater. The thermal shield design, the novel recirculating water flow distribution scheme, the high porosity tube supports used in the parallel flow regions, and the U-bend supports are discussed for the Wolsung Plant steam generators. Experimental and analytical development programs undertaken to verify the design features are outlined.
The main features are presented of a computer programme for 3-D thermohydraulic and thermodynamic analysis of the PGV-1000 horizontal steam generator used at the Temelin NPP. The programme provides analyses of primary side hydraulics, heat exchange behavior and the steam generator secondary side thermohydraulics and thermodynamics. Given are calculated data on the circulation flow rate, void fraction, heat transfer dynamics and the swelled level. (Z.S.) 9 figs.
The nuclear power plants with WWER type reactors are characterized by horizontally situated steam generators (SG). During seismic event the horizontal and vertical ground accelerations induce fluid motion in directions of longitudinal and transversal axis. Resulting dynamic forces act on the SG attachment and could cause the failure of screws. In obvious PSA scenarios, these phenomena are classified as a indirect induced LOCA. In this paper the effects of transversal sloshing of fluid are analyzed.
The Second International Seminar on Horizontal Steam Generator Modelling was arranged to continue the international cooperation that was started during the first seminar in March 1991. The main topics of the seminar were: (1) further experimental results on horizontal steam generator behaviour, (2) resent developments in modelling, (3) results on analyses and studies on primary-to-secondary side leakages, and (4) results of the common exercise calculations.
This paper dealt with the identification of possible damaging mechanism of the collector of the WWER 440 steam generator, cracking of primary collectors, corrosion damage of the protective coat of the primary collector circumferential weld, cracking of breathing space in the region of blinding effect by corrosion and strain, leaking of disassembling joint of the primary collector lid and with the integrity of heat exchanging tubes.
Previous models and evaluation techniques based on the Monte Carlo simulation for the reliability assessment of mixed hydrothermal generation systems are extended. Models for reservoirs on multiple rivers and pumped storage plants are developed. Operating and water management policies are extended to include the relative economical effects of operating alternative sources of generation. These effects and the benefits are described and discussed using an extended IEEE reliability test system. (Author).
As a maintenance optimization project to improve the safety of Wolsung NPP (Nuclear Power Plant), reliability of diesel generators are estimated based on the operating experience, and improvement options are suggested. A reliability measure is suggested for the estimation of reliability for standby safety systems to reflect availability. It is assessed that the reliability of diesel generators can be mush improved if the suggested improvement options are implemented. (Author) 6 refs., 1 tab.
As a maintenance optimization project to improve the safety of Wolsung NPP (Nuclear Power Plant), reliability of diesel generators are estimated based on the operating experience, and improvement options are suggested. A reliability measure is suggested for the estimation of reliability for standby safety systems to reflect availability. It is assessed that the reliability of diesel generators can be much improved if the suggested improvement options are implemented.
The article applies the Probability Safety Assessment approach to analyze the risk impact of extension of allowed outage time of emergency diesel generator in Daya Bay NPP and adopts the risk-acceptance criteria used by NRC to evaluate changes to the licensing basis. The assessment results show that the risk impact is acceptable to increase the emergency diesel generator allowed outage time from 3 days to 14 days. (authors)
This paper presents a series of modeling experiences and problems in simulating the thermal-hydraulic behavior of large PWR steam generators using the RELAP4 and RELAP5 computer codes. Sensitivity studies investigating the heat transfer characteristics of both once-through and U-tube steam generators are discussed. Suggestions and recommendations are given for effective use and potential future improvements of these codes.
Design layout of horizontal steam generator (SJ) with a special feedwater heating surface (by a surface water economizer), designated for NPPs with WWER-1000 reactors, is suggested. The design enables to decrease sharply the difference between the temperatures of saturation and feedwater. Blowdown outlet is organized against PG face, which increases the efficiency of flowing. The suggested layout enables to decrease thermal stresses in structural units and PG metal content, as compared to the PGV-1000 steam generator.
This paper presents results of solid-liquid phase change, driven by volumetric energy generation, in a vertical cylinder. We show excellent agreement between a quasi-static, approximate analytical solution valid for Stefan numbers less than one, and a computational model solved using the CFD code FLUENT®. A computational study also shows the effect that the volumetric energy generation has on both the mushy zone thickness and convection in the melt during phase change.
We study the possibility of utilizing the superfluid to Mott-insulator quantum phase transition in an array of quantum well exciton-polariton traps to generate indistinguishable single photons in a massive parallel fashion. By means of analytical and numerical methods, the device operations and system properties are examined using realistic experimental parameters. Such a deterministic, massive parallel generation may find new applications in photonic quantum information processing.
A nozzle plug for blocking a nozzle in a nuclear steam generator is improved by the addition of hinges which allow the nozzle plug to be inserted into the steam generator through an access port of substantially smaller diameter than the nozzle. A recess is provided in one of the semi-circular plates allowing the plates to nest, further reducing the necessary size of the access port.
Plasma with a gas temperature below room temperature is not yet fully understood although it is expected to be an attractive tool for applications to material processing. In the present work, gas-temperature-dependent generation of a cryoplasma jet was studied. So far, we have generated a helium cryoplasma jet (296-5 K) under atmospheric pressure. At gas temperatures below 20 K, the helium excimer, He2, was observed clearly from by optical emission spectroscopy.
Electricity is a universal energy and one of the driving powers of civilisation. World-wide, future developments like growing economies and structural changes in industry, a higher standard of living and a bigger world population - are impossible without appropriate supply of power and electricity. An expert of Siemens Power Generation presents his views. (orig.)
This document describes a simple and general way to generate House Simulation Protocol (HSP)-consistent internal sensible and latent loads in unoccupied homes. It is newly updated based on recent experience, and provides instructions on how to calculate and set up the operational profiles in unoccupied homes. The document is split into two sections: how to calculate the internal load magnitude and schedule, and then what tools and methods should be used to generate those internal loads to achieve research goals.
We propose a scheme able to generate stationary continuous variable entanglement between an optical and a microwave cavity mode by means of their common interaction with a micro-mechanical resonator. We show that when both cavities are intensely driven one can generate bipartite entanglement between any pair of the tripartite system, and that, due to entanglement sharing, optical-microwave entanglement is efficiently generated at the expense of microwave-mechanical and opto-mechanical entanglement.
Statistical detail is given of the electricity generation and transmission systems in the UK. Breakdown by type of station, by fuel and the proportion generated by others apart from the generating or area boards is presented. Figures are provided for the various high voltage transmission lines in terms of route and circuit length as well as the number of towers and the capacity of mains transformers.
This is a manuscript for a lecture contents: 1. Steam power and fundamentals of the steam power process, 2. conventional, nuclear and other steam generation processes, 3. cooling systems for steam power plants, 4. gas turbine power plants and combined-cycle power plants, 5. cogeneration, 6. development of thermal power plants and environmental effects. (orig.).
This is a manuscript for a lecture contents: 1) Steam power and fundamentals of the steam power process, 3) conventional, nuclear and other steam generation processes, 4) cooling systems for steam power plants, 5) gas turbine power plants and combined-cycle power plants, 6) cogeneration, 7) development of thermal power plants and environmental effects. (GL).
Results of weight measurement of PGV-213 steam generator during filling in, heating-up and power increase are described. Special measurement system based on stress gauges has been developed. Method of derivation of secondary water inventory is described. Comparison of the data for two steam generators prove accuracy of the measurements. (orig.). 1 refs.
This current awareness bulletin announces on a semimonthly basis the current worldwide information entered into the Energy Data Base on all aspects of direct energy conversion. Categories include photovoltaic conversion, magnetohydrodynamic generators, electrohydrodynamic generators, thermoelectric generators, thermionic converters, fuel cells, and miscellaneous converters. An abstract is inclluded with each citation. (WHK)
Specifications of the PGV-1000 steam generators applied at the WWER-1000 NPP power units, operational experience and data on damages at the 'cold' heat carriers of steam generators are considered and their results are presented. Developed and introduced measures aimed at improving reliability and operational life of the PGV-1000 collectors are described.
We present an approach to automatically generate interfaces supporting personalized interaction with digital libraries; these interfaces augment the user-DL dialog by empowering the user to (optionally) supply out-of-turn information during an interaction, flatten or restructure the dialog, and enquire about dialog options. Interfaces generated using this approach for CITIDEL are described.
The presentation gives a brief insight on possibility of using the VEERA facility in studying the stratification phenomenon. The idea for such experiments is to use the facility upper plenum part to simulate the conditions in upper part of horizontal steam generator hot collector. The upper part of steam generator hot collector is one of the locations where the stratification can take part during natural circulation mode. 4 refs.
This program is designed in order to calculate electricity generation cost by different energy sources, and menu type is adopted for user convenience. This program also graphically shows the share of capital investment cost, O and M cost, and fuel cost. Sensitivity analysis about discount rate can also be carried out by this program, taking into consideration the important role of the discount rate in the generation costs calculation. (Author) 7 refs., 1 fig., 3 tabs.
There are a total of nine operational nuclear plants in Spain totalling 7.350 MWe. These units produced 54.265 x 106 KWh in 1990, 36% of the total generation in Spain. Seven of these plants are of the PWR type. The first plant in operation was Jose Cabrera (ZORITA) in 1968, one loop Westinghouse plant with a model 24 Steam Generator. Due to the design margin and careful operation of the Steam Generator of this plant its performance have been very good, with only 5% tubes plugged after 23 years of operation. This is one of the few units in the world that remains in phosphate chemistry. During the period 1981-1985 a total of four units, two in Almaraz and two in Asco entered in operation. These three loop s Westinghouse units use model D-3 preheater Steam Generators. The poor design and manufacture of the Steam Generators of these units have caused a large number of problems: ...
A nonlinear mathematical model is presented of a WWER-440 nuclear power plant horizontal steam generator. On the proposed model is based a computer program for investigating transients in steam generators during loss of coolant accidents. Processes taking place at the primary side of the steam generator are described by a set of partial differential equations while those at the secondary side of the steam generator are described by plain differential equations with the variables being complex time functions. The model takes account of the coolant as both a single- and two-phase medium, of changes in the direction of the primary coolant flow and of changes in the direction of heat transfer. Heat transfer through the wall is based on a simple model of heat transfer through a thin-walled tube and includes a correction for the heat resistance of the wall. (author).
After explaining the main causes for the limited power output of turbine generators with 50 s"-"1, the limits for superheated-steam turbines and for saturated-steam turbines are given. A comparison of the economy in the limiting output range (1,200 MW) shows that half load plants as well as two-shaft turbine generators do not bring any advantages as compared with a single-shaft turbine generator. For the selection of speed of the single-shaft turbine generator the planned way of application is decisive. For base load plants already a speed of 25 s"-"1 is economic in this power range. Concluding, some design features and problems of development for such large turbines with 25 s"-"1 for conventional steam conditions are discussed. (orig.).
This paper uses multi-pass iteration particle swarm optimization (MIPSO) to solve short term hydroelectric generation scheduling of a power system with wind turbine generators. MIPSO is a new algorithm for solving nonlinear optimal scheduling problems. A new index called iteration best (IB) is incorporated into particle swarm optimization (PSO) to improve solution quality. The concept of multi-pass dynamic programming is applied to modify PSO further and improve computation efficiency.The feasible operational regions of the hydro units and pumped storage plants over the whole scheduling time range must be determined before applying MIPSO to the problem. Wind turbine power generation then shaves the power system load curves. Next, MIPSO calculates hydroelectric generation scheduling. It beg...
This study presents a full cost approach to determine the levelized cost of energy (LCOE) of 14 electricity generation technologies. It encompasses costs incurred at all stages of the fuel cycle, including those that are traditionally omitted from economic evaluations of generation technologies. Incorporating these 'externalities' increases the likelihood of developing the most economical and sustainable power resource from a societal perspective. The following externalities are included in this analysis: damage from air pollution, energy security, transmission and distribution costs, and other environmental impacts. Incorporating externalities has a large impact on the LCOE and the relative attractiveness of electricity generation options. Results indicate that clean and efficient generation technologies are the most attractive when all options are examined using a full cost, ...
This paper reviews generation methods of artificial earthquake motion and proposes an improved method of generating input motions for use in vibration tests of equipment to prove aseismic performance. The improved method employs beat wave repetition characteristic that inherently appears in the component waves of recorded earthquakes decomposed by bandpass filter and algebraic function phase for the component waves. Typical motions generated by the improved method satisfies prescribed severe conditions such as target response spectrum that are defined with a wideband frequency component and a limited maximum acceleration due to shaking table performance. The motions had never been generated by the conventional method.
Rice husk generated as a by-product of rice processing is an important energy resource. The availability of this resource in India has been assessed and the technologies for exploitation of its energy potential in rice processing industry discussed. Nomographs have been developed for estimation of the husk required to meet the energy demand of parboiling, drying and milling operations. The unit cost of electricity using rice husk gasifier-based power generation systems has been calculated and its financial feasibility assessed in comparison with utility-supplied and diesel-generated electricity. With the cost and efficiency data assumed here, the unit cost of electricity produced by rice husk gasifier-dual fuel engine-generator system varies between Rs 2/kWh and Rs 7/kWh. (author)
Rice husk generated as a by-product of rice processing is an important energy resource. The availability of this resource in India has been assessed and the technologies for exploitation of its energy potential in the rice processing industry discussed. Nomographs have been developed for estimation of the husk required to meet the energy of parboiling, drying and milling operations. The unit cost of electricity using rice husk gasifier-based power generation systems has been calculated and its financial feasibility assessed in comparison with utility-supplied and diesel-generated electricity. With the cost and efficiency data assumed here, the unit cost of electricity produced by rice husk gasifier-dual fuel engine-generator system varies between Rs 2/kWh and Rs 7/kWh. (35 Rs approximates to SUS 1.). (author)
Event generators that handle neutrino-nucleon interaction have been developed for the FLUKA code [1]. In earlier FLUKA versions only quasi-elastic (QEL) interactions were included, and the code relied on external event generators for the resonance (RES) and deep inelastic scattering (DIS). The new DIS+RES event generator is fully integrated in FLUKA and uses the same hadronization routines as those used for simulating hadron-nucleon interactions. Nuclear effects in neutrino-nucleus interactions are simulated within the same framework as in the FLUKA hadron-nucleus interaction model (PEANUT), thus profiting from its detailed physics modelling and longstanding benchmarking. The generators are available in the standard FLUKA distribution. They are presently under development and several improvements are planned to be implemented. The physics relevant to the neutrino-nucleon interactions and the results of ...
Since the first operation of nuclear steam generator early 1960s, its performance requirements have been met but the steam generator problems have been met but the steam generator problems have been major cause of reducing the operational reliability, plant safety and availability. U-tube assembly of steam generator forms the primary system pressure boundary of the plant and have experienced several types of tube degradation problems. Tube failure and leakage resulting from the degradation will cause radioactive contamination of secondary system by the primary coolant, and this may lead to unplanned plant outages and costly repair operations such as tube plugging or steam generator replacement. For the case of steam generators for heavy water reactors, e.g. Wolsong 2, 3, and 4 NPP, a high cost of heavy water will be imposed additionally. During the plant ...
Two major developments have given impetus to wider adoption of variable-speed turbine/generators in hydroelectric plants, both essentially environmental: (1) the need for stream-bed stability below river dams, and (2) the need to minimize fish damage. Also, the need to stabilize pumped-storage and generating efficiencies to match extreme changes in head levels has been a driving force. Variable-speed operation in hydro applications is relatively new to North America. In other parts of the world, it has been used in pumped-storage plants since 1971. In the US, and increasing potential exists for variable-speed hydro, considering the 30 pumped-storage plants already in operation and several river plants struggling with high head fluctuations--including four at stations operated by the Bonneville Power Administration. Several modifications to hydro-plant hardware and operating procedures are actively being considered at Bonneville--all of them ...
Power system stabilizers (PSSs) are used to enhance damping of power system oscillations through excitation control of synchronous generator. The objective of the PSS is to generate a stabilizing signal, which produces a damping torque component on the generator shaft. Conventional PSSs are designed with the phase compensation technique in the frequency domain and include the lead-lag blocks whose parameters are determined according to a linearized power system model. The performance of conventional PSSs (CPSSs) depends upon the generator operating point and the system parameters, but a reasonable level of robustness can be achieved depending on the tuning method. This paper presents a new three-dimensional PSS (3D PSS), which uses rotor speed deviation, rotor acceleration and load angle deviation as input signals. The 3D PSS attempts to return the generator to the state-space ...
The generation of available potential energy (APE) in the space-time domain in January and July in a present-day climate simulation with a general circulation model (GCM) is compared with observations. An attempt is made to explain the differences. The generation is computed from the fields of diabatic heating and temperature. The heating is computed with the residual method, using UKMO (United Kingdom Meteorological Office) Unified Model GCM circulation data and ECMWF (European Centre for Medium-Range Weather Forecasts) initialized analyses for the period 1989-1992. The global value of the generation of APE is about 35% larger in the GCM climate than the value computed from the analyses. This is mainly because the generation of transient eddy APE in the GCM is too large, due to the more than 40% too large generation of transient eddy kinetic energy by baroclinic processes. In most ...
Vertical U-tube steam generators in Pressurized Water Reactors (PWRs) operating an All Volatile Treatment (AVT) secondary chemistry have experienced corrosion problems, particularly denting and sludges. The studies reported evaluate the feasibility of using a low-concentration (0.5 wt%) chemical cleaning process to remove corrosion product deposits from steam generator surfaces and magnetite from tube-to-support plate crevices of PWR steam generators. The process potentially may be applied at schedule intervals, such as during normal refueling outages, to maintain a steam generator in clean operating condition. This report describes the results of testing to evaluate the effectiveness of several chelant acids for dissolving steam generator sludges and crevice magnetite. Corrosion of carbon steel by the chelant acids and the effects of various inhibitors are evaluated. The ...
A reflux condensing start-up system includes a steam generator, a start-up vessel connected parallel to the steam generator, a main steam line connecting steam outlets of the steam generator and start-up vessel to a steam turbine, a condenser connected to an outlet of the turbine and a feedwater return line connected between the condenser and inlets of the steam generator and start-up vessel. The start-up vessel has one or more heaters at the bottom thereof for heating feedwater which is supplied over a start-up line to the start-up vessel. Steam is thus generated to pressurize the steam generator before the steam generator is supplied with a heat transfer medium, for example liquid sodium, in the case of a liquid metal fast breeder reactor. The start-up vessel includes upper and lower bulbs with a smaller diameter mid-section to act as ...
Construction of the French PWR nuclear program started in the early 70s, at the time a number of operating plants in the US were being affected by the first corrosion problems. Since, at that time, its construction program was in an early stage, FRAMATOME was able to make modifications on the first units to improve steam generator resistance to corrosion. For instance, full depth expansion of the tubes in the tube-sheet using an explosive process (Westex) was performed on Fessenheim 1 steam generators already installed on site. Later on, continuous operating experience was being obtained in the US, before startup of the French units. This allowed FRAMATOME to react rapidly and take immediate corrective actions at the design stage, during fabrication and sometimes even on site in order to mitigate the risk of corrosion in the steam generators. FRAMATOME is confident that the present design of its steam ...
This project evaluated the feasibility of using a low-concentration (approx. 0.5 wt %) chemical cleaning process to remove corrosion product deposits from steam generator surfaces and magnetite from tube-to-support plate crevices of PWR steam generators. The primary objective was to develop a dilute process that could be safely applied at scheduled intervals, such as during normal refueling outages, to maintain a clean operating condition in the steam generator. The dilute chemical cleaning process developed in this project was demonstrated successfully on two model generators which were operated on faulted chemistry by DOE/CRC at Commonwealth's State Line Facility. Unit 5 was cleaned after 48 days of operation with 1% seawater fouling, and Unit 6 was cleaned after 112 days of operations with Lake Michigan water. This report describes work leading to the model generator ...
This project evaluated the feasibility of using a low-concentration (approx. 0.5 wt %) chemical cleaning process to remove corrosion product deposits from steam generator surfaces and magnetite from tube-to-support plate crevices of PWR steam generators. The primary objective was to develop a dilute process that could be safely applied at scheduled intervals, such as during normal refueling outages, to maintain a clean operating condition in the steam generator. The dilute chemical cleaning process developed in this project was demonstrated successfully on two model generators which were operated on faulted chemistry by DOE/CRC at Commonwealth's State Line Facility. Unit 5 was cleaned after 48 days of operation with 1% seawater fouling, and Unit 6 was cleaned after 112 days of operations with Lake Michigan water. This report describes work leading to the model generator cleaning ...
The interrelations between the factors causing the main effects on the primary circuit coolant flow rate distribution in the horizontal steam generator pipes in reactor facilities with the WWER type reactors under the modes with natural circulation are discussed. The criterion showing the presence or absence of coolant circulation reversal in bottom rows of the steam generator pipes is obtained. It is shown that large hydraulic non-uniformity in steam generator pipes operating in parallel under coolant natural circulation leads to decreasing the heat transfer surface efficiency under reactor facility emergency cooling, restricts its servicing capabilities. The circulation reverse in steam generator pipes under coolant natural circulation mode can give unfavourable effect on separate structural elements of the steam generators and as a result it can cause additional temperature ...
Nuclear Engineering Laboratory of the Technical Research Centre of Finland has widely used RELAP5/MOD2 and -MOD3 codes to simulate horizontal steam generators. Several models have been developed and successfully used in the VVER-safety analysis. Nevertheless, the models developed have included only rather few nodes in the steam generator secondary side. The secondary side has normally been divided into about 10 to 15 nodes. Since the secondary side at the steam generators of VVER-440 type reactors consists of a rather large water pool, these models were only roughly capable to predict secondary side flows. The paper describes an attempt to use RELAP5/MOD3 code to predict secondary side flows in a steam generator of a VVER-440 reactor. A 2D/3D model has been developed using RELAP5/MOD3 codes cross-flow junctions. The model includes 90 volumes on the steam generator secondary side. ...
Nuclear Engineering Laboratory of the Technical Research Centre of Finland has widely used RELAP5/MOD2 and -MOD3 codes to simulate horizontal steam generators. Several models have been developed and successfully used in the VVER-safety analysis. Nevertheless, the models developed have included only rather few nodes in the steam generator secondary side. The secondary side has normally been divided into about 10 to 15 nodes. Since the secondary side at the steam generators of VVER-440 type reactors consists of a rather large water pool, these models were only roughly capable to predict secondary side flows. The paper describes an attempt to use RELAP5/MOD3 code to predict secondary side flows in a steam generator of a VVER-440 reactor. A 2D/3D model has been developed using RELAP5/MOD3 codes cross-flow junctions. The model includes 90 volumes on the steam generator secondary side. ...
A calculation model was developed for the analysis of thermal and hydraulic processes in the PGV-1000 horizontal steam generator. The model makes it possible to examine the hydraulics of the primary medium, i.e., the distribution of flow velocities and mass flows in the exchanger tube system and hydraulic losses of the primary medium in the steam generator during its flow between the two connecting sites to the main circulation pipeline, spatial distribution of heat fluxes between the primary and secondary sides of the steam generator and the total transmitted thermal power, pressure on the secondary side of the generator, natural circulation of the working medium on the secondary side, and the mean circulation number, spatial distribution of the volume fraction of the steam component in the intertubular space, effect of the perforated sheet on the thermo-hydraulic processes in the steam ...
The steam generator low water level trip setpoint of KORI NPP units 3 and 4(KNU 3 and 4), three-loop Westinghouse pressurized water reactor, is higher than that of OPR1000. In addition, steam generator downcomer water level in KNU 3 and 4 could fluctuate easily during a transient because of smaller downcomer water inventory, compared to the total water inventory in the steam generator. Due to these reasons, there is a higher possibility of unnecessary reactor trips caused by the steam generator low-low water level in KNU 3 and 4. Its operating history shows that most of reactor trips were caused by steam generator low-low level reactor trip signal. Such reactor trips, especially unnecessary ones, result in time and economic losses. In this paper, a feasibility study was performed to reduce unnecessary reactor trip by changing steam generator low-low water level ...
The steam generator low water level trip setpoint of KORI NPP units 3 and 4(KNU 3 and 4), three-loop Westinghouse pressurized water reactor, is higher than that of OPR1000. In addition, steam generator downcomer water level in KNU 3 and 4 could fluctuate easily during a transient because of smaller downcomer water inventory, compared to the total water inventory in the steam generator. Due to these reasons, there is a higher possibility of unnecessary reactor trips caused by the steam generator low-low water level in KNU 3 and 4. Its operating history shows that most of reactor trips were caused by steam generator low-low level reactor trip signal. Such reactor trips, especially unnecessary ones, result in time and economic losses. In this paper, a feasibility study was performed to reduce unnecessary reactor trip by changing steam generator low-low water level ...
Because of past military operations, lack of upkeep and looting there are now enormous radioactive waste problems in Iraq. These waste problems include destroyed nuclear facilities, uncharacterized radioactive wastes, liquid radioactive waste in underground tanks, wastes related to the production of yellow cake, sealed radioactive sources, activated metals and contaminated metals that must be constantly guarded. Iraq currently lacks the trained personnel, regulatory and physical infrastructure to safely and securely manage these facilities and wastes. In 2005 the International Atomic Energy Agency (IAEA) agreed to organize an international cooperative program to assist Iraq with these issues. Soon after, the Iraq Nuclear Facility Dismantlement and Disposal Program (the NDs Program) was initiated by the U.S. Department of State (DOS) to support the IAEA and assist the Government of Iraq (GOI) in eliminating the threats from poorly controlled radioactive materials. ...
The inherited sterility of the spiny bollworm Earias Insulana Boisd. Irradiated as parental male adults, with sub sterilizing doses of 100-200 Gy has been studied throughout three successive generations. In general, the female fecundity decreased at the three doses of irradiations (100, 150 and 200 Gy) throughout P_1. F_1, F_2 and F_3 generations as compared to control. The reduction was insignificant in all treatments with some exceptions at 200 Gy, in the parental generation and 150 and 200 Gy bin F_2 generation. Egg hatch of the parental generation was obviously reduced at 100, 150 and 200 Gy treatments as compared to the control. The progeny of F_1 males were evidently more sterile than their irradiated male parents. The effect continued in the F_2, population, however F_3 males almost regained their fertility. Irradiation of P_1 males did not greatly affect mating ability among ...
Different types of generators have been developed for the convenient use of {sup 99m}Tc as the demand for this radioisotope is strong. Currently, the demand for {sup 99m}Tc is more than 80 % of the total demand for medical isotopes in the world. A {sup 99m}Tc generator, in general, is composed of a column packed with ceramic adsorbent, tubing, eluent reservoir or vials, collection vials, and shielding. The key technology to develop a good generator is how to load {sup 99}Mo as much as possible while maintaining the quality of eluted {sup 99}mTc as good as possible. The technology is well developed and already available commercially for the case of the fission {sup 99}Mo/{sup 99}mTc because loading of few curries of {sup 99}Mo on a conventional adsorbent, i.e. alumina is not a serious task in the chemical point of view. However, the current infrastructure of the supply of {sup 99}Mo to the world market is sturdy as the ...
The trade-off which must be established between the various functions of pumped-storage plants is examined. A compromise between supply security and economic planning can be found only by coordinated planning of pumped-storage units and thermal generation plants. A model used by Electricite de France (EDF) to ensure optimized daily planning of thermal and pumped-storage units is described. The model, called the DEMETER model, ensures the optimization of the daily planning of thermal and pumped-storage plants. The model iterates between two levels: coordination where the prices of the generated energy and the operating reserve are determined to adjust generation to load and keep a sufficient reserve; and decomposition where the schedule of each unit is optimized on the basis of the above prices and taking into account local constraints such as unavailability, and minimum shut down time. The role of EDF is to supply customers ...
Object: To control the average liquid level of each steam generator at a constant level irrespective of the flow rate of sodium thereby to decrease change in the retained amount of sodium and at the same time to improve the load response characteristic. Construction: A method for decreasing to as large an extent as possible a change in the amount of sodium retained in a steam generator due to change in the flow rate, which comprises the steps of detecting the main recirculating flow rate of liquid sodium by the use of a sodium flow rate detector, amplifying the detected flow rate signal depending upon the ratio between the flow rates respectively in a super-heater and a re-heater (distribution ratio), delivering the amplified signal to a function generator which generates a liquid level setting signal for maintaining the respective average liquid levels of the super-heater and the re-heater at constant ...
the cotton leaf worm, Spodoptera littoralis (boisd.) were irradiated with 100,150 and 200 Gy to induce inherited sterility. the effects of the tested doses applied to these pupae through three consequent fillial generations and the retarded influence on their F_1,F_2 and F_3 generations progeny were examined . irradiation of parental male induced damage to their daughter females ovaries. the overioles of females among P_1 ,F_1 and F_2 generations showed that the follicular epithelial cells appeared abnormal beside their limited separation from developing oocytes which became shrinked, semi absorbed or completely absorbed leaving vacuoles. the nurse cells were reduced or absent in some parts. damage was obvious through the first and second generations especially at 150 and 200 Gy. in the third generation, ovaries were not greatly affected
The Feedwater System supplies feedwater to the steam generator at the required pressure, temperature and flow rate during the plant start-up, normal power operation, shutdown. When the Feedwater System is inoperable or unavailable, the Auxiliary Feedwater System supplies emergency feedwater to the steam generator. If main steam line break occurs, the increase of feedwater flow rate of the faulted steam generator due to decrease of the pressure in the faulted steam generator results in adverse effects in aspect of overcooling the Reactor Coolant System and increased containment pressure/temperature. To optimize the containment mass/energy analysis, this paper evaluates the maximum feedwater and auxiliary feedwater flow rate delivered to the faulted steam generator at each stage of pressure decrease in the faulted steam generator after a main steam line break ...
Relativistic electron beams are used for generating high power microwaves. These microwave sources require electron beam generators spanning significant ranges in voltage and impedance. The pulsed power technology used to generate these electron beams is presented. Electron beam generators that produce beams with pulse durations in the 10-ns to 100-ns regime consist of an energy-storage section, pulse-shaping section, and an electron beam diode. The energy-storage section is either a Marx generator or capacitor bank-pulsed transformer. The pulse shaping is done with high-voltage transmission lines. The electron beam diode is usually a cold-cathode, space-charge-limited flow device. For longer pulses (/approximately/1 ..mu..s) the energy storage and pulse chaping can be combined. Lumped-element pulse-forming networks (PFN) can be designed to produce the desired pulse shape. The Marx ...
Relativistic electron beams are used for generating high power microwaves. These microwave sources require electron beam generators spanning significant ranges in voltage and impedance. The pulsed power technology used to generate these electron beams is presented. Electron beam generators that produce beams with pulse durations in the 10 ns to 100 ns regime consist of an energy storage section, pulse shaping section, and an electron beam diode. The energy storage section is either a Marx generator or capacitor bank-pulsed transformer. The pulse shaping is done with high-voltage transmission lines. The electron beam diode is usually a cold-cathode, space-charge-limited flow device. For longer pulses (approx.1 ..mu..s) the energy storage and pulse shaping can be combined. Lumped-element pulsed-forming networks (PFN) can be designed to produce the desired pulse shape. The Marx ...
Pressurized fluidized bed combustion (PFBC) is an emerging coal-fired, combined-cycle power generation technology nearing commercial status through several operating and planned demonstration plants throughout the world. Current-generation PFBC plants use ``ruggedized`` gas turbines that can tolerate dust loading common with conventional cyclone gas cleaning. The next generation of PFBC will apply advanced hot gas cleaning systems that will reuse the dust loading to low levels acceptable to high performance, industrial gas turbines. These advances should result in performance and cost advantages. This article examines the demonstration of PFBC technology at Tidd power station.
TVA is currently engaged in an extensive program to mitigate steam generator tube denting at the Sequoyah Nuclear Plant, which is in commercial operation, and to prevent or minimize the onset of denting at the Watts Bar Nuclear Plant, which is under construction. This paper describes TVA's denting mitigation program, which is primarily feedwater chemistry and system operation improvement, and the effect the changes that have been implemented have had on the incidence as well as the progression rate of steam generator tube denting during the past 220 effective full power days of Sequoyah unit 1 operation.
The color centers, which are generated in yttrium-aluminium perovskite (YAP):Nd(1 at.%) and YAP:Er(50 at.%) crystals under the influence of ultraviolet and #gamma#-irradiation, have been studied by absorption spectroscopy. The generated color centers are both stable and transient at room temperature. It is shown that the transient color centers are mainly responsible for the decrease of laser generation efficiency of Nd:YAP and YAP:Er irradiated crystals, although physical mechanisms leading to efficiency decrease are different in these materials. (orig.)
This report illustrates how, thanks to the development of a new algorithm for the probabilistic evaluation in a given period (e.g. one week) of the operating costs and risk indices (reliability) of a generation system with energy-constrained units, it has been possible to significantly improve the WAT program, used for many years by ENEL for generation expansion planning studies. In particular, it describes how the annual simulation of the system operation is accomplished, so as to calculate the mean expected values of the yearly operating costs (fuel) and the risk indices, at the same time optimizing the use of hydro resources and pumped-storage plants. (author).
Taiwan`s LNG consumption is planned to rise more than threefold over the next four years as medium-term plans to develop power generation facilities increasingly rely on gas-fired combined-cycle stations to avoid the threat of power shortages. State-run Taiwan Power Company (Taipower) expects its LNG consumption to rise from 1.1 mn tonnes in 1996 to 3.4 mn tonnes in the year 2000. By then the first of several gas-fired private power stations is expected to enter service, further increasing Taiwan`s total LNG requirement for power generation. (Author)
In situ optical absorption spectroscopy was used to study the generation of E' centres in amorphous SiO_2 occurring by photo-induced breaking of Si-H groups under 4.7eV pulsed laser radiation. The dependence from laser intensity of the defect generation rate is consistent with a two-photon mechanism for Si-H rupture, while the growth and the saturation of the defects are conditioned by their concurrent annealing due to reaction with mobile hydrogen arising from the same precursor. A rate equation is proposed to model the kinetics of the defects and tested on experimental data.
We studied the optimum plasma conditions that are required for efficient high-order harmonic generation in platinum plume. Harmonics up to the 49th order (?=16.32 nm) are analyzed under various conditions of laser-plasma interaction. Time-resolved ultraviolet spectra of platinum plasma at both optimum and nonoptimum conditions of harmonic generation are presented. We calculated the ionization states of the plasma, free electron density, and singly charged ion density at different prepulse intensities and compared them with experimental results.
Eight years ago, corrosion and tube denting seriously threatened the reliability and design life of steam generators, especially for closed loop arrangements in pressurized water reactors (PWRs). Concentrated research by the Steam Generator Owners Group (SGOG) diagnosed the causes and produced effective solutions, notably guidelines for water chemistry control in the secondary loop. The guidelines recommend specific levels of water impurities and remedial actions to prevent cooling-water leaks in the condenser, prevent air leaks, limit corrosion product buildup, and remove some impurities while neutralizing others. Continued research in SGOB-II is investigating intergranular corrosion and stress corrosion cracking. 3 figures.
Eight years ago, corrosion and tube denting seriously threatened the reliability and design life of steam generators, especially for closed loop arrangements in pressurized water reactors (PWRs). Concentrated research by the Steam Generator Owners Group (SGOG) diagnosed the causes and produced effective solutions, notably guidelines for water chemistry control in the secondary loop. The guidelines recommend specific levels of water impurities and remedial actions to prevent cooling-water leaks in the condenser, prevent air leaks, limit corrosion product buildup, and remove some impurities while neutralizing others. Continued research in SGOB-II is investigating intergranular corrosion and stress corrosion cracking. 3 figures.
All power plant engineers face the problem of peak power demands. Pumped storage plants are used to generate peak load power by pumping up water utilizing off-peak energy of hydrothermal and thermonuclear plants. This is the first accessible text/reference to cover hydroelectric power generation with emphasis on engineering to meet peak power demands by means of pumped storge plants, tidal power plants, and low head power generation. Text covers hydrology, mechanical and electrical equipment, accessories such as penstocks and valves, and civil engineering considerations. Contains descriptions of several existing plants. Includes 200 diagrams and 50 photographs.
All power plant engineers face the problem of peak power demands. Pumped storage plants are used to generate peak load power by pumping up water utilizing off-peak energy of hydrothermal and thermonuclear plants. This is a reference to cover hydroelectric power generation with emphasis on engineering to meet peak power demands by means of pumped storage plants, tidal power plants, and low head power generation. Text covers hydrology, mechanical and electrical equipment, accessories such as penstocks and valves, and civil engineering considerations. Contains descriptions of several existing plants. Includes 200 diagrams and 50 photographs.
This study presents a theoretical analysis of heat generation and dissipation of field-controllable magneto-rheological fluid (MRF) shock absorbers. Since MRF dampers are energy- dissipating devices, the issues of heat generation and dissipation are important in predicting their performance. A theoretical model is developed based on Bingham plastic model to estimate temperature history of the MRF dampers. The governing equation includes the MRF viscosity as a function of the temperature. The numerical solutions are compared with experimental results in order to validate the accuracy of the model, and excellent agreements are obtained.
Coherent x-ray production by a seeded free electron laser (FEL) is important for next generation synchrotron light sources. The authors examine the feasibility and features of FEL emission seeded by a high-order harmonic generation (HHG) of an infrared laser. In addition to the intrinsic FEL chirp, the longitudinal profile and spectral bandwidth of the HHG seed are modified significantly by the FEL interaction well before saturation. This smears out the original attosecond pulselet structure. The authors introduce criteria for this smearing effect on the pulselet and the stretching effect on the entire pulse. They discuss the noise issue in such a seeded FEL.
Large scale steam storage power generation, one of the new energy storage systems for the future of inflexible electric power sources consisting of nuclear and coal power plants has been studied on the subjects of the systems to be attached to coal and nuclear power units, of the definition of storage efficiency and of the vertical steam storage vessel technology. Steam storage power generation may be hopeful for its higher efficiency similarly defined as of pumped storage plants while high temperature heat storage and the internal structure of large vertical steam storage vessel (accumulator) need to be developed.
Large scale steam storage power generation, one of the new energy storage systems for the future of inflexible electric power sources consisting of nuclear and coal power plants has been studied on the subjects of the systems to be attached to coal and nuclear power units, of the definition of storage efficiency and of the vertical steam storage vessel technology. Steam storage power generation may be hopeful for its higher efficiency similarly defined as of pumped storage plants while high temperature heat storage and the internal structure of large vertical steam storage vessel (accumulator) need to be developed. (author).
A confocal microscopy imaging system was devised to selectively detect Second harmonic signals generated by biological tissues. Several types of biological tissues were examined using this imaging system, including human teeth, bovine blood vessels, and chicken skin. All these tissues generated strong second harmonic signals. There is considerable evidence that the source of these signals in tissue is collagen. Collagen, the predominant component of most tissues, is known to have second order nonlinear susceptibility. This technique may have diagnostic usefulness in pathophysiological conditions characterized by changes in collagen structure including malignant transformation of nevi, progression of diabetic complications, and abnormalities in wound healing.
System instability as result of high power generation of one of the largest plants of the Iranian electric power grid prevented the plant to be fully utilized. PSSs were installed on the generating units of the power station, to improve its small signal stability, and enhance the stable generation limit. Domain separation and pole assignment techniques were applied for the PSS design. Several field tests were also carried out to verify its effectiveness. This paper presents the PSS tuning procedure, including the design criteria and some of the field test results.
When analyzing the loss-of-coolant accidents at VVER reactor NPP the problem of the effect of noncondensable gases on heat transfer in a horizontal steam generator (HSG) is gaining in importance. Based on the RELAP5/MOD3.2 computer code one analyzed the experiments to condense steam-and-gas mixture in a HSG. The calculations are shown to predict satisfactorily duration of steam generator poisoning from noncondensable gas
In this paper the thermal design of a horizontal steam generator for the Indian PHWR nuclear power plant is described. The main attraction is absence of tube sheet and use of stainless steel 'U' tubes. It is emphasised that with appropriate water chemistry it is possible to use stainless steel tubes, which is many times cheaper than the Incoloy tubes used elsewhere. The design approach, applicable equation for the design and the results of computation in the form of heat transfer area and some important dimensions of the steam generator are presented.
This Fact Sheet presents the mission of the West Valley Demonstration Project and information on the 1994 pollution prevention and recycling accomplishments.
or third generation fuels. These are biofuels that can directly substitute for gasoline, jet fuel, and diesel. Today more than 9 billion gallons of biofuels are produced annually...
... animal through a mask by isoflurane and maintained by a balanced anesthesia, which consisted of an intramuscular injection of Innovar-vet (0.11 ...
The lateral bearing device is made of 7 lateral supports, each positioned to allow the displacement of the steam generator due to thermal or seismic effects. Each support includes a buffer plate that can be positioned on the steam generator using a position control assembly. This control assembly consists of a screw jack arrangement where the nut is fastened via an energy absorbing layer to a footplate that is fixed to the concrete wall of the steam generator enclosure. 4 figs.
Denturism, an organized movement by dental laboratory technicians to increase their control over the provision of denture services to the public, has generated a great deal of controversy among members...Full Text Available
The removal of toxic metals and alkalis from gas streams at high temperatures was investigated. This is important for the development of coal-fired combined cycle power generation systems.
... the effect of MBH on steam generator crevice corrosion; model boiler test results show that MBH is effective against denting corrosion and Alloy 600 ...
This paper describes the modeling of horizontal steam generator with the TRACE code and calculation results of a loss-of-feedwater (LOF-10) experiment at the PACTEL facility. Parallel Channel Test Loop (PACTEL) is an integral test facility for a VVER-440 type nuclear reactor. The main objectives were to prepare a simulation model for its horizontal steam generator with the TRACE thermal hydraulic code and assess different modeling options of the code. PACTEL experiment LOF-10 was chosen for this assessment. The calculation results showed that TRACE is capable in simulating horizontal steam generator behavior both in steady state and during loss-of-feedwater transient. The phenomenon of heat transfer from primary to secondary side, steam superheating and flow reversal in the lowest heat exc...
Mitsubishi is now developing a next-generation Pressurized Water Reactor (PWR) which has the innovative feature of hybrid safety systems (optimum combination of passive safety system and active safety system) and passive core cooling by horizontal steam generators during Loss of Coolant Accident (LOCA). In order to confirm the capability of this passive core cooling system during LOCAs, the thermal-hydraulic tests of horizontal steam generator and the integral thermal-hydraulic tests simulating the LOCAs were performed. The thermal-hydraulic tests of horizontal steam generator consist of a single tube test and a multi-tubes test. On the basis of these test results, the heat transfer characteristics of steam-water two-phase flow with noncondensable gas along a long horizontal tube is understood and the heat transfer correlation including the effect of noncondensable gas is presented. The integral ...
Steam generators for nuclear plants require access to the primary and secondary side for various inspection, cleaning and repair procedures and upon achieving access various inspection and cleaning tasks must be carried out. Steam generators currently at manufacture are therefore provided with; primary side access via the primary manways, steam drum access via the steam drum manway, U-bend region access via the secondary manway and drum-internals access passages, tubesheet secondary side access via tubesheet level inspection ports and tube support plate access via tube support level access ports. Many CANDU steam generators were built with only primary and drum manways and either no tubesheet ports or ports which were located ineffectively. The steam generators at Wolsong 1 were built with secondary side inspection ports that provided only limited access away from the no-tube-lane. In addition they have ...
The steam generator availability is one of the important problems encountered during the pressurized water nuclear plant operation. Various kinds of corrosion phenomena were observed in the past. These phenomena result from the concentration of impurities mainly in three locations in the steam generators: the tubesheet crevices, the tube support plate crevices, and the sludge pile. Corrections were made in the design and the materials used but a number of steam generators suffer or will suffer from corrosion processes inducing in many cases forcing their replacement. In order to prevent or to retard the corrosions several laboratories have performed experiments to reproduce and to study the corrosion processes. The first step of the degradation is the concentration of chemical species. A method using /sup 24/Na as a radioactive tracer was used to establish the concentration kinetics of caustic which was identified as the ...
The go ahead for setting up the Smart Grid has been given - on the consumer side, for example, in the form of intelligent electricity meters (Smart Meter). It will be some years, however, before a comprehensive and integrated generation, transport and consumer concept can be implemented. An integral part of this implementation concept will be intelligent energy systems that coordinate individual local power grids and thus ensure optimum exploitation of the power generated. But even without full grid networking energy management can be shaped more intelligently - for example by combining and optimising the power generation capacities of several power plant locations and energy carriers. (orig.)
A reasonable understanding of PWR steam generator corrosion mechanisms such as denting and wastage has been developed, and adequate chemistry control programs defined to obviate the magnitude and effects of these modes of attack. However, relatively unique corrosion attack modes have been encountered at several plants notwithstanding the presence of a reasonable to very good chemistry control program when considered in light of the Steam Generator Owners Group chemistry guidelines. The uniqueness of attack also suggests that parameters not routinely measured or monitored may be playing a significant role. In the authors opinions, the only reasonable method of routinely identifying corrosion accelerating species present in crevices, sludge piles, and deposits in PWR steam generators is by performing detailed chemical return studies during power transients, shutdowns, and long term layups. Although it would be preferable to ...
cellulose casing material made by Food Products Division,. Union Carbide Corporation. tion of the anode from oxygen generated at the charging electrode. ...
In order to improve the reliability of PWR steam generators, we have performed research to improve the tubing material and tube-support-plate configuration, based on our wide operating experience, and have developed and verified Alloy TT690 as the optimum tubing material and the BEC (Broached Egg Crate) type tube-support design. In the research, we have studied the metallurgical mechanism of the alloy to improve its corrosion resistance, evaluated corrosion susceptible region quantitatively, estimated the actual environment in a steam generator and confirmed the reliability by a model boiler test over a long period. It has been verified that the steam generator with the latest design has higher reliability with respect to the corrosion resistance of tubes. (author).
Process residues are generated at both the Rocky Flats Plant (RFP) and the Savannah River Plant (SRP) during aqueous chemical and pyrochemical operations. Frequently, process operations will result in either impure products or produce residues sufficiently contaminated with transuranics to be nondiscardable as waste. Purification and recovery flowsheets for process residues have been developed to generate solutions compatible with subsequent Purex operations and either solid or liquid waste suitable for disposal. The ''scrub alloy'' and the ''anode heel alloy'' are examples of materials generated at RFP which have been processed at SRP using the developed recovery flowsheets. Examples of process residues being generated at SRP for which flowsheets are under development include LECO crucibles and alpha-contaminated hydraulic oil.
fuel obligation under the RFS2 program for the production or importation of conventional jet fuel, RINs can be generated for renewable jet fuel. Is that right? A: As described in...
The Lie algebra so(2n+1) and the Lie superalgebra osp(1/2n) are quantized in terms of 3n generators, called preoscillator generators. Apart from n "Cartan" elements the preoscillator generators are deformed para-Fermi operators in the case of so(2n+1) and deformed para-Bose operators in the case of osp(1/2n). The corresponding deformed universal enveloping algebras U_q[so(2n+1)] and U_q[osp(1/2n)] are the same as those defined in terms of Chevalley operators. The name "preoscillator" is to indicate that in a certain representation these operators reduce to the known deformed Fermi and Bose operators.
The chronology of installing solar power in a rural area of Ontario is described. The installation took all of seven years, and was characterized by a lot of joy, but also a lot of heartache and hardship, all of which are chronicled in this article. The project started with four solar modules generating 300 watts, nickel cadmium batteries of 225 Ah, an inverter of 600 watt, and a three-cylinder 6.5 Kw water-cooled propane generator. Today, nearly seven years later, the installation consists of 18 solar modules supplying 1350 watts of power, lead-acid batteries of 2770 Ah, a 2500 watt inverter, a one cylinder, 5.5 kw propane-gasoline generator, a heated, underground generator house, complete with an amp-hour meter and MPPT charge controller.
Non-linear optics encompasses a range of optical phenomena, including two- and three-photon fluorescence, second harmonic generation (SHG), sum frequency generation (SFG), difference frequency generation (DFG), third harmonic generation (THG), coherent anti-Stokes Raman scattering (CARS), and stimulated Raman scattering (SRS). The combined advantages of using these phenomena for imaging complex pharmaceutical systems include chemical and structural specificities, high optical spatial and temporal resolutions, no requirement for labels, and the ability to image in an aqueous environment. These features make such imaging well suited for a wide range of pharmaceutical and biopharmaceutical investigations, including material and dosage form characterisation, dosage form digestion and drug rele...
In this paper, we suggest that perception could be modeled by assuming that sensory input is generated by a hierarchy of attractors in a dynamic system. We describe a mathematical model which exploits...Full Text Available
The kWh model finds the kWh outputs of each plant and reservoir capacities of hydro and pumped storage plants and minimizes the sum of fixed charges for constructing the reservoirs and generating facilities, also the fuel costs of thermal and nuclear plants. It is a linear programming problem whose constants are represented by nonlinear functions of kW running capacity of each plant. The optimal pattern of nuclear and thermal units is found by solving the linear programming problem derived for the pumped storage and hydroplants. Excluding the upper bound constraints, the number of constraint equations are few and do not increase with the number of units, although the number of variables increases. The computing time increases only in proportion to the number of groupings of generating units. Sensitivity analysis can be done easily. The detailed operational behavior of each generating unit can be taken into account.
Data on French nuclear electricity generation sites, nuclear power plant operations personnel, operation simulators, nuclear training centers and training statistics are presented.
A technology for removal of undissolved impurities from a horizontal steam generator using purge water is developed on the basis of a theoretical analysis. A purge with a maximal flow rate is drawn off from the zone with the highest accumulation of sludge in the lower part of the steam generator after the main circulation pump of the corresponding loop is shut off and the temperatures of the heat transfer medium at the inlet and outlet of the steam generator have equilibrated. An improved purge configuration is used for this technology; it employs shutoff and regulator valves, periodic purge lines separated by a cutoff fixture, and a D y 100 drain union as a connector for the periodic purge. Field tests show that the efficiency of this technology for sludge removal by purge water is severa...
... This paper presents our research in neural learning for predicting ... Denote this feature set as F4. ... can be observed that the SOC curves generated by ...
Sep 1, 2011 ... Description: What amount of extra energy can be generated after subtracting the total energy consumed to produce the biomass energy? ...
In the National Water Plan it is described which measures must be taken to keep the Netherlands safe and livable for future generations and to make use of the chances offered by water.
Jun 4, 2004 ... On a two-year trip to Mars, according to one estimate, a crew of six humans will generate more than six tons of solid organic waste--much of ...
Reporters are invited to a tour and ceremony for the Lockheed Martin C-130J, the military's next generation of front-line cargo aircraft and troop carrier, ...
material may survive intact and mix back into interstellar gas clouds, helping to fuel the next generation of stars. NASA's Jet Propulsion Laboratory, Pasadena, Calif.,...
Mice are an ideal mammalian model for studying the genetics of aging: considerable resources are available, the generation time is short, and the environment can be easily controlled, an important...Full Text Available
The kinetic energy transferred to some elements by an electron of kinetic energy 100 to 400 kV is discussed. The displacement rates are compared to the signal generation. (DCL)
Male reproductive proteins (MRPs), associated with sperm and semen, are the moieties responsible for carrying male genes into the next generation. Evolutionary biologists have focused on their...Full Text Available
Jun 16, 2011 ... Description: Most of the approximately 25 to 30 million tons of industrial wood waste generated in the United States per year is burned for ...
Mechanisms, AGARD Conference Proceedings No. 131, 1974, Paper No. 11. ... Olsen, W. and Karchmer, A., Lip Noise Generated by Flow Separation From Nozzle ...
Results of calculational investigations into circulation of water and steam-and-water mixture in the PGV-1000 steam generator heat exchanger bundle used at NPPs with the WWER-1000 reactors, are considered. Model of water circulation in horizontal steam generator with submerged heating surface under conditions of steam generation irregularity along the heat transfer tubes is made. On the basis of the obtained data the assumption is made about water essential overflows from the hot collector zone into the cold one. Overflow rate over the upper line of the heat transfer tubes may constitute 0.7 m/s. The conclusion is made about the necessity to set up the vertical barrier which divides hot and cold sections of heat transfer tubes and helps to avoid water transverse overflows.
Engineering details of a high voltage driven corona-plasma ozone generator are described. The plasma diode of generator has coaxial cylindrical geometry with cathode located inside anode. Cathode is made of a large number of radial gas nozzles arranged on central tubular mast which admits oxygen gas. The sharp endings of the nozzles along with a set of corona rings create the high electric field at the cathode required for formation of dense corona plume responsible for O_3 evolution. A model of coronal plasma generation and ozone production is presented. The plasma formation is strongly dependent on the electric field and temperature in side diode where a high electron density in a low temperature negative corona is suited for high ozone yields. These are established by suitable regulation of A-K gap, voltage, oxygen pressure, and cathode-nozzle population.
This paper deals with the heat transfer characteristics of horizontal steam generators, particularly under natural circulation (decay heat removal) conditions on the primary side. Special emphasis is on the inherent features of horizontal steam generator behaviour. A mathematical model of the horizontal steam generator primary side is developed and qualitative results are obtained analytically. A computer code, called HSG, is developed to solve the model numerically, and its predictions are compared with experimental data. The code is employed to obtain for VVER 440 steam generators quantitative results concerning the dependence of primary-to-secondary heat transfer efficiency on the primary side flow rate, temperature and secondary level. It turns out that the depletion of the secondary inventory leads to an inherent limitation of the decay energy removal in VVER steam generators. ...
Nanocrystalline powders of GaN with grain sizes ranging from 2 to 30 nm were examined under high external pressures by in situ diffraction techniques in a diamond anvil cell at DESY (HASYLAB, Station F3). The experiments on densification of pure powders under high pressure were performed without a pressure medium. The mechanism of generation and relaxation of internal strains and their distribution in nanoparticles was deduced from Bragg reflections recorded in situ under high pressures at room temperature. The microstrain was calculated from the full-width at half-maximum (FWHM) values of the Bragg lines. It was found that microstrains in GaN crystallites are generated and subsequently relaxed by two mechanisms: generation of stacking faults and change of the size and shape of the grains occurring under external stress. (author)
Experience with the identification and tuning of exciter constants for a generating unit as the Second Nuclear Power Plant of Taiwan Power Company is reported. Field test is first performed on the excitation system with the generator open-circuited. Since the field test results differ from the computer simulation results using manufacturer`s constants, the authors first modify the manufacturer`s constants based on their previous experience to reach a preliminary set of parameters for the excitation system. Then a hybrid nonlinear simulation-sensitivity matrix method is developed to further refine the excitation system parameters. The exciter constants are tuned in order to give better dynamic response before a power system stabilizer is applied to the generator. Field tests are then performed in order to compare the dynamic response of the generator without and with power system stabilizer.
Experience with the identification and tuning of exciter constants for a generating unit as the Second Nuclear Power Plant of Taiwan Power Company is reported. Field test is first performed on the excitation system with the generator open-circuited. Since the field test results differ from the computer simulation results using manufacturer's constants, the authors first modify the manufacturer's constants based on their previous experience to reach a preliminary set of parameters for the excitation system. Then a hybrid nonlinear simulation-sensitivity matrix method is developed to further refine the excitation system parameters. The exciter constants are tuned in order to give better dynamic response before a power system stabilizer is applied to the generator. Field tests are then performed in order to compare the dynamic response of the generator without and with power system stabilizer.
The rational use of energy has become a priority for all industries in Brazil, mainly after the energy rationing in 2001. Methodologies to quantify and improve the performance of plants that consume and generate electricity and thermal energy are being used to reach this goal. Exergoeconomic analysis provides a complete diagnosis of a plant, both in exergetic and in monetary values. This study shows the methodology used to assess the power generation system of the Companhia Siderurgica Tubarao (CST). The current system is based on a regenerative Rankine cycle using two gases from steel production - blast furnace gas (BFG) and coke oven gas (COG) - to generate electric power and occasionally steam for the process. Use of the Theory of Exergetic Cost allowed determination of monetary and exe...
An energy saving dc-dc converter circuit is disclosed having two energy efficient means which operate in tandem, an energy conserving means and a voltage doubling means. These energy efficient means are applied in combination with elements commonly found in dc-dc converter circuits, namely an ac voltage generator, a transformer for stepping up the generated ac voltage, and means for storing the converted dc voltage. The energy conserving means is connected to the dc voltage storage means. It comprises a resettable inhibit circuit which cuts off the provision of dc voltage for conversion for a predetermined interval when the output of the converter exceeds a predetermined level. The voltage doubling means is reponsive to outputs of the inhibit circuit of the energy conserving means and the ac voltage generator. It provides a phase inverted waveform of the generated ac voltage on one of two leads to the ...
The Coal and Electric Data and Renewables Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy prepares the EPM. This publication provides monthly statistics at the State, Census division, and US levels for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fossil fuels are also displayed for the North American Electric Reliability Council (NERC) regions. The EIA publishes statistics in the EPM on net generation by energy source; consumption, stocks, quantity, quality, and cost of fossil fuels; and capability of new generating units by company and plant. 68 tabs.
The Coal and Electric Data and Renewables Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy prepares the EPM. This publication provides monthly statistics at the State, Census division, and U.S. levels for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fossil fuels are also displayed for the North American Electric Reliability Council (NERC) regions. The EIA publishes statistics in the EPM on net generation by energy source; consumption, stocks, quantity, quality, and cost of fossil fuels; and capability of new generating units by company and plant.
The possible long-term effects of chronic radiation exposure have been studied. Rats were given tritiated drinking water (3 #mu#Ci/ml) before and during pregnancy and thereafter continuously through five generations. The brains were studied at 30 and 120 days postnatally. Significant decreases in weight and DNA and protein contents of specific parts of the brain were found, the most pronounced decreases being in the diencephalon. The decrease in protein content were more pronounced than the decreases in DNA content; the decreases were also more pronounced at 30 days than at 120 days, and more pronounced in the fith generation than in previous generations.
Effect of Abdominal Active Can on DFTs. Introduction: Many patients with implantable cardioverter defibrillators (ICDs) have older lead systems, which are usually not replaced at the time of pulse generator replacement unless a malfunction is noted. Therefore, optimization of defibrillation with these lead systems is clinically important. The objective of this prospective study was to determine if an active abdominal pulse generator (Can) affects chronic defibrillation thresholds (DFTs) with a dual-coil, transvenous ICD lead system. Methods and Results: The study population consisted of 39 patients who presented for routine abdominal pulse generator replacement. Each patient underwent two assessments of DFT using a step-down protocol, with the order of testing randomized. The distal right ...
The major contents in this study are as follows : - long-term forecast to the year of 2040 is provided for nuclear electricity generating capacity by means of logistic curve fitting method. - the role of nuclear power in a national economy is analyzed in terms of environmental regulation. To do so, energy-economy linked model is developed. By using this model, the benefits from the introduction of nuclear power in Korea are estimated. Study on inter-industry economic activity for nuclear industry is carried out by means of an input-output analysis. Nuclear industry is examined in terms of inducement effect of production, of value-added, and of import. - economic analysis of nuclear power generation is performed especially taking into consideration wide variations of foreign currency exchange rate. The result is expressed in levelized generating costs. (author). 27 refs., 24 tabs., 44 figs
SOME SCIENTISTS ALLEGE that exposure to electric and magnetic fields generated by electric power delivery systems is responsible for certain cancers (particularly among children), reproductive dysfunction,...Full Text Available
There is an ever increasing demand to perform flow simulations that incorporate the complete details of geometry as well as sophisticated flow physics. This has led to the development of numerical algorithms that can simulate the actual flow phenomena with greater fidelity. However, the success of these algorithms hinges on the grid that models the geometry. Grid generation methods for 2-D models have long existed and the general lack of complexity of the simpler 2-D models has not quite challenged the efforts in this area. However, demands for generating better 3-D geometric models for flow simulations involving complex geometries have completely changed the perspective of grid generation strategies. As a consequence, grid generation efforts have earned equal significance as that of numerical solver efforts.
Interactions (FCCI) University of Wisconsin, Madison Thermal Properties of LiCl-KCl Molten Salt for Nuclear Waste Separation University of Wisconsin, Madison Next Generation...
A full analysis is shown in this paper for the cost of kWh generated from photovoltaic station located in Kuwait. By using a 21 years weather data for Kuwait, the yearly generated energy was found by proposing the PV station capacity with known panels tilt angle. The cost of kWh generated from PV station was compared with the kWh generated from conventional units in the country. A sensitivity analysis was done to some factors, capital cost per installed PV peak watt, discount rate, and operating peak hours, which affect the cost of kWh production from both PV and conventional units. If the PV station is proposed to be installed in Kuwait, the capital cost per PV installed peak watt must be less than today`s prices. (author)
May 25, 2007 ... This form will generate a bibliography of cost estimating references. The form will search the NASA Technical Report Service (NTRS) database ...
The objective of the C-E/EPRI project, ''Alternative Steam Generator Materials and Designs,'' was to evaluate the corrosion behavior of contemporary or alternative steam generator materials under prototypic design and secondary fault (high contaminant) water conditions. Two model steam generators built with various support materials and designs were tested under representative thermal and hydraulic conditions. One model operated under seawater faulted all-volatile treatment (AVT) secondary water chemistry conditions. The other model operated under acidified fresh water faulted AVT conditions. This presentation focuses on the tube support and tubesheet corrosion results obtained by destructive examination of both models.
Objectives:The efficacy of user-defined subject tagging and software-generated subject tagging for describing and organizing cancer blog contents was explored.Methods:The...Full Text Available
High-throughput genomic and proteomic technologies have generated a wealth of publicly available data on ageing. Easy access to these data, and their computational analysis, is of great importance in...Full Text Available
The possible long term effects of chronic radiation exposure have been studied. Rats were given tritiated drinking water (3#mu#Ci/ml) before pregnancy, during pregnancy and threafter, continuously through 5 generations. The brains were studied at 30 and 120 days postnatally. Significant decreases in weight, DNA and protein contents of specific parts of the brain were found, the most pronounced decreases being in the diencephalon. The decreases in protein content were more pronounced than the decreases in DNA content; the decreases were also more pronounced at 30 days than at 120 days, and more pronounced in the fifth generation than in previous generations. An attempt was made to explain these complex phenomena on the basis of known periods of proliferation of various brain cells, damage to mothers themselves in each generation, and damage and repair of nucleic acids caused by radioactivity.
Several steam generator tube rupture accidents have occurred at plants in the past. In this paper the Computational Multi-Fluid Dynamics (CMFD) investigation of the horizontal steam generator thermal-hydraulics during the tube rupture accident is performed. A guillotine of a steam generator U-tube is assumed with choked flow from the primary to the secondary side of the steam generator. We have computed water and steam velocity fields, steam volume fraction distribution on the steam generator secondary (shell) side, as well as the swell level increase. The simulation results are a support to the safety analyses of the steam generator tube rupture accident. Numerical simulation is performed with the multidimensional multi-fluid modelling approach. The two-phase flow around steam generator tubes in the bundle is modelled by the porous media ...
The next generation of particle accelerator is currently being designed at CERN. An understanding of the market forces in the computer industry will play a crucial role in the success of the project.
... Thus initiation will be from the shock generated from the front surface of the pellet after traversing the inert packing. Exploding bridgewire detonator ...
SummaryObjectiveTo assess the level of noise generated by music shops in an urban city in Nigeria. Study designCross-sectional, descriptive study. MethodologyThe study involved music shops in three out of eight identified clusters of market areas in Benin City. A semi-structured, researcher-administered questionnaire was also used to collect data from music shop owners. Noise levels generated by speakers in the music shops were measured using a sound level meter, and blood pressure measurements were taken with a mercury sphygmomanometer. ResultsOf the 250 music shops studied, more than 90.0% generated noise levels >85 dB, and 54.8% had a continuous pattern of noise. Longer duration of working years was significantly associated with decreased hearing (P = 0.01), shouting when talking (P = 0...
The effects of antimalarials, chloroquine and quinacrine, on the generation of reactive oxygen species were examined both in polymorphonuclear leucocytes and in the xanthine-xanthine oxidase system....Full Text Available
Three experiments were conducted to study the behaviour of the new horizontal steam generator construction of the PACTEL test facility. In the experiments the secondary side coolant level was reduced stepwise. The experiments were calculated with two computer codes RELAP5/MOD3.1 and APROS version 2.11. A similar nodalization scheme was used for both codes so that the results may be compared. Only the steam generator was modeled and the rest of the facility was given as a boundary condition. The results show that both codes calculate well the behaviour of the primary side of the steam generator. On the secondary side both codes calculate lower steam temperatures in the upper part of the heat exchange tube bundle than was measured in the experiments. (orig.) 4 refs.
Three experiments were conducted to study the behaviour of the new horizontal steam generator construction of the PACTEL test facility. In the experiments the secondary side coolant level was reduced stepwise. The experiments were calculated with two computer codes RELAP5/MOD3.1 and APROS version 2.11. A similar nodalization scheme was used for both codes so that the results may be compared. Only the steam generator was modeled and the rest of the facility was given as a boundary condition. The results show that both codes calculate well the behaviour of the primary side of the steam generator. On the secondary side both codes calculate lower steam temperatures in the upper part of the heat exchange tube bundle than was measured in the experiments. (orig.).
within the United States for the benefit of present and future generations of Americans Kenai National Wildlife Refuge. Photo Credit: USFWS/Steve Hillebrand Kenai National Wildlife...
Several scientists have proposed that DNA repair deficiencies and the induction of a mutator phenotype are responsible for the generation of multiple mutagenic alterations in cancer cells. I propose...Full Text Available
In two recent papers, we constructed a new N#->##infinity# limit of the W_N algebras, which we denote W_#infinity# having generators of conformal spins 2, 3, ..., with central terms for all spins. In this paper, we construct another new algebra, which we denote W_1_+_#infinity#, with generators of conformal spins, 1, 2, 3, ..., again with central terms for all spins. The requirement that the algebras be closed requires that one include the spin-1 generators in W_1_+_#infinity#, and prohibits their inclusion in W_#infinity#. Paralleling our analogous construction for W_#infinity#, we show that the new algebra can also be realised as the antisymmetric part of an associative 'lone-star' product, which also closes on the set of generators with conformal spins #>=#1. (orig.).
In the spring of 2009, the Romanian government has proposed a restructuring of the national power generation sector segment that is still owned by the state. As most of the power generation capacity is still state-owned, this restructuring will dramatically alter the competitive landscape of this sector. This paper is analyzing the rationale and principles of the restructuring as stated by government documents and officials, the assessment methodology and criteria proposed by the government, as well as the proposed final outcome of the restructuring initiative. Based on this critical assessment and the early results of the restructuring's implementation, we are able to make recommendations that can be considered for a revised restructuring approach. - Research highlights: #-># Power generation sector restructuring is proposed in 2009 by the Romanian government. #-># We assess the objectives, methodology and proposed ...
We briefly discuss the transcendental constants generated through the #epsilon# expansion of generalized hypergeometric functions and their interrelation with the 'sixth root of unity.'
Smith-Purcell (S-P) radiation is produced when electrons graze the surface of a grating. Calculations based on the theory of diffraction radiation show that, given severe restrictions on e"--beam quality, S-P radiation is highly efficient. Efficient S-P x-ray generation requires relativistic e"- beams having a transverse momentum and dimension whose product approaches the Heisenberg uncertainty limit.
New non-collinear schemes are suggested for transverse velocity modulation of electron beams and for the generation of coherent spontaneous radiation by these transversely modulated beams. It is shown that due to the non-collinearity some orders of magnitude enhancement can be achieved for the coherent spontaneous radiation (CSR) power at both the fundamental and harmonic frequencies.
Some general topical information (generating capacity and electric power generation, development and structure of electric power consumption, frequency and peak load, exchange of electricity) is followed by an account of the situation of coal-fired power plants, hydroelectric power plants and nuclear power plants, and a brief discussion of the environmental situation (emissions and wastes, immissions, and air pollution abatement measures for power plants). (orig./UA).
An operator of FE-closure is introduced on the set of functions of a multivalued logic based on the systems of functional equations. It is proved that, for every k ? 2, the FE-closure operator generates a finite classification on the set P k of functions of k-valued logic. The least class in this classification is shown to be the class H k of all homogeneous functions. Also a series of corollaries are obtained concerning the finite FE-generating sets in the FE-closed classes.
The approach estimating the leak probability of flanged joint due to the destruction of fastening studs is described. The mentioned approach consists of two stages. The probability of destroying one stud is calculated at the first stage, and the probability of different combination interpositions of intact and destroyed studs is calculated at the second one. The probability calculation of leak in the area of collector cover of steam generator PGV-1000 is used as an example of developed approach
Background. New-generation drug-eluting stents (DES) may solve several problems encountered with first-generation DES, but there is a lack of prospective head-to-head comparisons between...Full Text Available
Computer simulations and experiments indicate that we can shape the infrared picosecond pulses of the Mark III FEL in amplitude, frequency, and phase. Strongly modulated fundamental and second harmonic pulses have been generated by operating the Mark III FEL in the regime of strong sideband growth. In this paper, we present the results of simulations and experiments for second harmonic generation with fundamental inputs from 2 to 3 {mu}m.
An experimental study of second harmonic generation in a copper-vapor pulsed laser with an ADP crystal is presented. The ratio of the conversion into the second harmonic is found to depend on the average power of the exciting radiation. The maximum conversion ratio was 8.5%. Thermal self-defocusing is the main obstacle to obtaining high average powers at the double frequency.
Peak at 60 deg in angular proton distribution in inelastic pion-carbon interactions is interpreted as generation of Cherenkov gluon radiation in flucton, passing into the shock wave with successive nucleus decay. Investigation of hadron-nuclear interactions with anomalous peak in angular proton distribution can be used as additional means for study both of flucton and mechanism of hadron-nuclear interactions. 5 refs.
As part of a handbook on the efficient use of energy a chapter is included which is intended to give an appreciation of the principles and problems involved in the generation of nuclear power. The subject is discussed under the following headings: introductory nuclear physics; basic reactor physics; thermal reactors; fast reactors; fuel reserves and utilization; environmental considerations; nuclear fusion. (U.K.).
This document draws together data on hydroelectric power generation and dam construction for 1996. Machinery such as turbines and hydroelectric generators are listed together with their manufacturers. Contact addresses for international organizations concerned with water power are listed. Listings are also given for hydro resources worldwide, and the global distribution of pumped-storage plants, dams and hydroelectric plants. Company data is also listed providing a buyer`s guide for 1996. (UK)
With the frequent load changes to which a hard coal power station is subjected in the middle and peak load range, great demands are linked with the transient behaviour of the steam generator. Due to the serial connection of the crusher and boiler, the strongly delaying transient behaviour of the crusher compounds entirely with the transient behaviour of the steam generator. Therefore, a suggestion is to be made here as to the improvement of the dynamics of the crusher.
Implementation of an adaptive power system stabilizer (PSS) based on linear optimal control is described in this paper. The generator is identified in real time, and a special 3rd order discrete Riccati equation is solved in each sample interval. Because the output of the generator is fed back directly, the controller can track the system very fast. Experimental studies on a physical model of a power system demonstrate the effectiveness of the proposed adaptive optimal controller.
The generating functional in which the residual gauge freedom has been broken is related to the conventional generating functional for QED in arbitrary dimension. Closed expressions which relate ordinary N-point Green functions to N-point Green functions in the different gauges are derived. The leading logarithmic behaviour of the electron propagator in three dimensions is thus obtained. It is argued that one should not ascribe much importance to the infrared behaviour of the fermion propagator in the context of confinement.
The technical rule intends to maintain the function of the safety facilities in case of explosion hazards resulting from materials capable of generating explosive atmospheres or forming explosive mixtures if such materials are brought or released into the nuclear facility or are generated on site. (orig.).
The technical rule intends to maintain the function of the safety facilities in case of explosion hazards resulting from materials capable of generating explosive atmospheres or forming explosive mixtures if such materials are brought or released into the nuclear facility or are generated on site. (orig.).
A novel approach to the reliability analysis of a power system with both hydro and pumped storage plants is presented in this paper. The proposed method is based on the concept of peak shaving for the hydro and pumped storage units. Different values of the stored energy of the pumped storage units are employed to demonstrate their effect on the generation reliability of a power system. The proposed scheme has been applied successfully to the reliability analysis of Taiwan power system.
It is often advantageous to generate power with combinations of wind and ocean waves. In fact ocean waves, their generation, propagation, dissipation are directly related to wind velocity and its duration oven the sea. In this paper an attempt has been made to demonstrate statistically to present some advantages with combined wind and ocean wave power generation. Even though many conceptual techniques and methods are possible to harness combined power generation, it is important to test feasibility of combined output as well as individual outputs mathematically. One of the major advantages of combined wind and wave power generation is to improve probability of continuous power supply (it minimises the interruptions and compensates power fluctuations with one another). Some of the major wave characteristics like wave Height (H), Time period (T), Wave length (L) significantly ...
In in-service inspection of steam-generator tubes, the need for reproducibility of the measurement results and for comparison of these results over two successive inspections has led EDF to specify the main characteristics of the Eddy-Current probes and to design equipment to measure them. This equipment is presented here and the electrical and magnetic results are correlated with those obtained by testing tubes with reference defects. 5 refs.
Literature references related to definition, generation, and use of evaluated cross section uncertainty (variance-covariance) files are listed with comments intended primarily to guide the reader toward materials of immediate interest. Papers are also cited that cover covariance information for individual experiments and that relate to production and use of multigroup covariance matrices. Titles are divided among several major categories.
Recent work on the aerodynamics of flapping flight reveals fundamental differences in the mechanisms of aerodynamic force generation between fixed and flapping wings. When fixed wings translate at high angles of attack, they periodically generate and shed leading and trailing edge vortices as reflected in their fluctuating aerodynamic force traces and associated flow visualization. In contrast, wings flapping at high angles of attack generate stable leading edge vorticity, which persists throughout the duration of the stroke and enhances mean aerodynamic forces. Here, we show that aerodynamic forces can be controlled by altering the trailing edge flexibility of a flapping wing. We used a dynamically scaled mechanical model of flapping flight (Re approximately 2000) to measure the aerodynamic forces on flapping wings of variable flexural stiffness (EI). For low to medium angles of attack, as flexibility of the wing ...
British Nuclear Fuels (BNFL) is currently operating its third generation of nuclear plant for the management of irradiated nuclear fuel. Development for the fourth generation plant must meet requirements for processing higher burn-up fuel with lower unit costs, lower environmental impact, better process control, and more flexible control of actinides. .
A self-tuning Power System Stabilizer (PSS) is suggested in this paper. Computer simulations, of a lightly-damped single turbine-generator supplying power to an infinite bus system, show that this self-tuning PSS can work over a large operating range and make a significant improvement in rotor damping.