Determination of the radiocarbon (14C) content of airborne particulate matter yields insight into the proportion of the carbonaceous material derived from fossil and contemporary carbon sources. Daily samples of PM2.5 were collected by high-volume sampler at an urban background site in Birmingham, UK, and the fraction of 14C in both the total carbon, and in the organic and elemental carbon fractions, determined by two-stage combustion to CO2, graphitisation and quantification by accelerator mass spectrometry. OC and EC content was also determined by Sunset Analyzer. The mean fraction contemporary TC in the PM2.5 samples was 0.50 (range 0.27-0.66, n=26). There was no seasonality to the data, but there was a positive trend between fraction contemporary TC and magnitude of SOC/TC ratio and fo...
This research has two main goals; (1) to quantify mechanisms for radon entry into homes of different types and to determine the fraction of indoor radon attributable to each source and (2) to model and calculate the dose (and therefore alpha particle fluence) to cells in the human and animal tracheobronchial tree that is pertinent to induction of bronchogenic carcinoma from inhaled radon daughters.
Airborne fine particle sulfur data from the summer intensive of Project MOHAVE (Measurement of Haze and Visual Effects) was analyzed by the Receptor Model Applied to Patterns in Space (RMAPS) model, a novel multivariate receptor-oriented model that applies to secondary and primary species. The sulfur data from 17 sites were found to be well predicted by three spatial patterns interpreted as sources along the valley of the Colorado River (including the large Mohave coal-fired power plant, a smaller power plant and the city of Las Vegas); transport from sources located to the southwest; and transport from sources located to the southeast. The model was tested by using parameters derived from the 17-site data set to apportion sulfur for six sites that were not part of the original data set. The sulfur apportionment for these site sites was in agreement with the original apportionment ...
Sucrose and mannitol are major photosynthetic products and translocates in celery. Assimilate partitioning and transport were studied by pulse-labeling leaves with /sup 14/CO/sub 2/ followed by different length chases in ambient air. After a 2 h chase in the light there was more /sup 14/C in sucrose than mannitol in source leaves and their petioles. In contrast after a 2 h dark chase leaves contained more /sup 14/C in mannitol than sucrose but petioles had more /sup 14/C in sucrose than mannitol. After a 15 h chase (6 h light; 9 h dark) labeled sucrose was higher in source petiole vascular bundles than in adjacent parenchyma tissue but label in glucose and fructose was higher in the parenchyma tissue. After the 15 h chase most of the /sup 14/C remaining in developing sink leaves ...
The biodegradation of ring-/sup 14/C- and methyl-/sup 14/C-labeled paraquat by the soil yeast Lipomyces starkeyi was studied in vitro. It was found that the degradation of paraquat (acting as a sole source of culture nitrogen) resulted in the accumulation in the extracellular medium of radiolabeled acetic acid. The culture also evolved radiolabeled CO/sub 2/. The results suggest that the degradation of paraquat by L. starkeyi is associated with the integrity of the cell wall and that disruption or removal of the wall results in a complete loss of degradative capability. A mechanism for the degradation of paraquat by this organism is postulated.
The biodegradation of ring-"1"4C- and methyl-"1"4C-labeled paraquat by the soil yeast Lipomyces starkeyi was studied in vitro. It was found that the degradation of paraquat (acting as a sole source of culture nitrogen) resulted in the accumulation in the extracellular medium of radiolabeled acetic acid. The culture also evolved radiolabeled CO_2. The results suggest that the degradation of paraquat by L. starkeyi is associated with the integrity of the cell wall and that disruption or removal of the wall results in a complete loss of degradative capability. A mechanism for the degradation of paraquat by this organism is postulated.
{sup 14}C is a is a long-lived beta-emitting nuclide (T{sub 1/2} = 5730 years) produced naturally in the upper atmosphere as a result of reactions between neutrons and stable {sup 14}N({sup 14}N(n,p){sup 14}C). Although in a lesser extent, nuclear power plants produce {sup 14}C as well during their routine operation. Since it is converted in {sup 14}CO{sub 2} and mixed throughout the atmosphere, it is incorporated into plant tissues, via photosynthesis process, and hence in food chain. Because of the biological importance of {sup 14}C and long half-life, it is of interest to quantify the amounts released by nuclear industry. The Brazilian nuclear central named Nuclear Central Admiral Alvaro Alberto (CNAAA) has two nuclear reactors of PWR type in operation, Angra I (657 MWe) and Angra II (1350 MWe), and one under ...
Fixation of /sup 14/CO/sub 2/ and activities of sucrose-synthesizing enzymes, sucrose phosphate synthetase (SPS) and sucrose synthase (SS), were assayed in tissues of developing fruit and source leaves from Citrus paradisi Macf. SPS activity of both the outer, chlorophyllous layer of the fruit (flavedo) and source leaves was 10-fold greater than that of the inner, largely non-chlorophyllous layer of the fruit peel (albedo). In contrast, SS activity of the flavedo was 2-fold greater than that of the albedo and 10-fold greater than that of leaves. Fixation of /sup 14/C-photosynthates in isolated tissues (flavedo 2x > albedo) and their redistribution in intact fruit indicated that flavedo functions as both source and sink. Activities of sucrose-synthesizing enzymes were consistent with this dual function.
Prior to this study, almost no up-to-date information was available on the 'background' level of "1"4C present in the water and biota of the UK coastal marine environment. The weighted mean "1"4C activity derived from the lowest activities of dissolved inorganic carbon (DIC) and biota for sites which are remote from potential sources is 247#centre dot#6#+-#1#centre dot#0 Bq kg"-"1 carbon. This is proposed as the best estimate of the natural/weapons testing 'background' for 1995 and should be subtracted from the activity derived for any sample to establish the excess due to UK anthropogenic inputs. "1"4C activities in the DIC component of seawater and a range of marine biota are significantly enhanced above the expected 'background' value in the environment around the British Nuclear Fuels plc reprocessing plant at Sellafield, Cumbria, NW England and Amersham International plc, Cardiff, Wales. The enrichments around Sellafield are largely confined to the NE Irish ...
The objective of this report is to review the different technologies for trapping the gaseous wastes containing Cs, Ru, Tc, {sup 14}C, Kr, Xe, I and {sup 3}H from a voloxidation process. Based on literature reviews and KAERI's experimental results on the gaseous fission products trapping, appropriate trapping method for each fission product has been selected considering process reliability, simplicity, decontamination factor, availability, and disposal. Specifically, the most promising trapping method for each fission product has been proposed for the development of the INL off-gas trapping system. A fly ash filter is proposed as a trapping media for a cesium trapping unit. In addition, a calcium filter is proposed as a trapping media for ruthenium, technetium, and {sup 14}C trapping unit. In case of I trapping unit, AgX is proposed. For Kr and Xe, adsorption on solid is proposed. SDBC (Styrene ...
The productivity of higher plants is, in part, dependent on transport of photosynthate from source to sink (in sugarcane, stalk) and upon its assimilation in cells of the sink tissue. In sugarcane, sucrose has been reported to undergo hydrolysis in the apoplast before uptake into the storage parenchyma, whereas recently, sucrose was reported to be taken up intact. This work was based on lack of randomization of ({sup 14}C)fructosyl sucrose accumulated after feeding tissue slices with this sugar. In this report, we present evidence from slices of stalk tissue that sucrose is taken up intact via a carrier-mediated, energy-dependent process. The evidence includes: (1) uptake of fluorosucrose, an analog of sucrose not subject to hydrolysis by invertase; (2) little or no randomization of ({sup 14}C) fructosyl sucrose taken up; (3) the presence of a saturable as well as a linear component ...
Lichens were collected in France in the surroundings of a military nuclear facility in Burgundy, near the la Hague reprocessing plant and in an area away from any direct source of contamination. Organically bound tritium (OBT) has been analysed on 18 samples and radiocarbon on 11. It appeared that on the most contaminated spots, the OBT activity in lichens was higher than the background by a factor of 1000 and was still a factor 10-100 at a distance of 20 km from the source. Radiocarbon from la Hague could be traced by lichens. The slow metabolism of lichens makes them suitable for the follow-up of {sup 3}H and {sup 14}C, which have been incorporated by photosynthesis.
Previous work showed that the segl mutant of barley (Hordeum vulgare o Betzes) did not differ from normal Betzes in plant growth, photosynthesis, or fertility, but it produced only shrunken seeds regardless of pollen source. To determine whether defects in sucrose uptake or starch synthesis resulted in the shrunken condition, developing grains of Betzes and segl were cultured in (/sup 14/C)sucrose solutions after slicing transversely to expose the endosperm cavity and free space. In both young grains (before genotypes differed in dry weight) and older grains (17 days after anthesis, when segl grains were smaller than Betzes), sucrose uptake and starch synthesis were similar in both genotypes on a dry weight basis. To determine if sucrose was hydrolyzed during uptake, spikes of Betzes and segl were allowed to take up (fructose-U-/sup 14/C)sucrose 14 days after anthesis and the ...
The development of the spatial N export and retention model N{sub E}XRET for large river basins is presented, utilizing remote-sensing-based land use and forest classification. Export coefficients describing the contribution from agriculture, forestry and peat harvesting were estimated based on empirical studies. Representativeness of forest treatment coefficients have been evaluated by use of data from a small, well-documented test catchment. Simulation results from the application of the model to the Oulujoki river basin (22,840 km{sup 2} ) are discussed. Model estimated N fluxes were compared with measured N fluxes in separate points of the river basin. Based on sourceapportionment, agriculture contributes 17% of the total export, varying between 8% in the uppermost subbasin and 38% in the lowermost subbasin close to the sea. Forestry contributes almost as much, 16%, with less pronounced variation (11-24%) between the different subbasins. ...
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 peanut plant (Arachis hypogaea L.), unlike other known legumes, can sustain nitrogen fixation when prolonged periods of darkness or detopping curtail the supply of photosynthate to the nodule. This ability to withstand photosynthate stress is attributed to the presence of lipid bodies in infected nodule cells. In both dark-treated and detopped plants, the lipid bodies show a gradual decrease in numbers, suggesting their utilization as a source of energy and carbon for nitrogen fixation. Lipolytic activity can be localized in the lipid bodies, and the existence of #beta#-oxidation pathway and glyoxylate cycle is shown by the release of "1"4CO_2 from "1"4C lineoleoyl coenzyme A by the nodule homogenate.
Abstract Four stratigraphic sections in the southern part of the Columbia Basin preserve a sequence of aeolian and non-aeolian sediments ranging in age from 943 to >470 14C ka based on accelerator mass spectrometry radiocarbon dating of fossil molluscs, geochemistry of Cascade Mountain-sourced tephra and association with formally recognized pedostratigraphic units (the Washtucna and Old Maid Coulee soils). Study sections are interpreted as representing concurrent deposition of loess and distal Missoula Flood rhythmites in valleys tributary to main drainages backflooded during the Missoula Floods, and formation of carbonate and iron-rich soils. Sediments belong to the formally recognized L-1 and L-2 loess units established for the Palouse loess, which were deposited in the Columbia Basin su...
The synthesis of (/sup 14/C)-10,11-Epoxy-(2E,6E)-farnesyl diazoacetate in one vessel, starting from (/sup 14/C)-glyoxylic acid, is described. This compound is useful as a potential photoaffinity labeling agent for juvenile hormone binding sites.
A simple and effective method is presented for the sizing and passage apportionment of multistream plate-fin heat exchangers. Methods for passage arrangement are discussed, and it is shown that a symmetric or mixed passage arrangement is more efficient than a segregated arrangement. A method for assessing the relative merits of various passage arrangements is presented. The use of the methods is illustrated through a worked example.
Hydrogen cyanide (HCN) production by Pseudomonas aeruginosa in a synthetic medium is stimulated by the presence of glycine. Methionine enhances this stimulation but will not substitute for glycine as a stimulator of cyanogenesis. Threonine and phenylalanine are effective substitutes for glycine in the stimulation of HCN production. Glycine, threonine, and serine are good radioisotope precursors of HCN, but methionine and phenylalanine are not. Cell extracts of P. aeruginosa convert (/sup 14/C)threonine to (/sup 14/C)glycine. H14CN is produced with low dilution of label from either (1-/sup 14/C)glycine or (2-/sup 14/C)glycine, indicating a randomization of label either in the primary or secondary metabolism of glycine. When whole cells were fed (1,2-/sup 14/C)glycine, cyanide and ...
A method was developed to synthesize /sup 14/C-labelled n-alkanes for use in cigarette smoke studies. Specifically, n-(18-/sup 14/C)-octatriacontane was synthesized from 1 mCi (1-/sup 14/C)stearic acid in a radiochemical yield of 20%. The key features of this synthesis were two consecutive alkylations of tosylmethyl isocyanide followed by acid hydrolysis to (18-/sup 14/C)-19-octatriacontanone and modified Wolff-Kishner reduction to the n-alkane. After purification on silica gel 25 mg of (18-/sup 14/C)octatriacontane was obtained with a total radioactivity of 200 ..mu..Ci, a specific activity of 4.3 mCi/mmol, and a radiochemical purity in excess of 98% by thin layer radiochromatography. The method has also been applied to the synthesis of unlabeled n-pentatriacontane and is ...
A rapid filtration technique has been used to measure at room temperature the kinetics of ADP and ATP transport in rat heart mitochondria in the millisecond time range. Transport was stopped by cessation of the nucleotide supply, without the use of a transport inhibitor, thus avoiding any quenching delay. The kinetics of ({sup 14}C)ADP transport in energized mitochondria were apparently monophasic. The rate of transport of ({sup 14}C)ATP in energized mitochondria was 5-10 times lower than that of ({sup 14}C)ADP. Upon uncoupling, the rate of ({sup 14}C)ATP uptake was enhanced, and that of ({sup 14}C)ADP uptake was decreased. However, the two rates did not equalize, indicating that transport was not exclusively electrogenic. Transport of ({sup ...
This presentation describes a method for separating {sup 14}C-hexose from {sup 14}C-sucrose in extracts of plant tissue. Portions of ethanol extracts are treated with activated charcoal in microcentrifuge tubes. Aliquots are removed, ethanol evaporated and replaced with reaction mixture that phosphorylates hexose (HEPPS, K{sub 2}HPO{sub 4}, Mg(C{sub 2}H{sub 3}O{sub 2}){sub 2}, ovalbumen, Na{sub 2}ATP, yeast hexokinase). After a time course, the hexokinase reaction is stopped (slowed considerably) to minimize effects of contamination enzyme activities. The stopping agent used is lyxose, a nonphosphorylable analogue of glucose. The strong anionic charge of phosphate introduced through the hexokinase action results in binding (> 95%) of hexose-phosphate to anion-exchange resin. Sucrose remains unbound (> 95%) in solution. This batch ion-exchange is performed in microcentrifuge tubes to allow many ...
Tilapia Nilotica were exposed to "1"4 C- carbofuran (125 MUg/1) and "1"4 C - lindane (80 MUg/1) for 96 h. Uptake period followed by 8 days depuration period. The bioconcentration factor (BCF) for carbofuran reached 32.4 at 12 h and 82 for lindane at 48 h. The amount of "1"4 C-activity found in fish treated with "1"4 C - carbofuran after the uptake period showed the following descending order: viscera > remaining parts > gills > muscles. In case of "1"4 C - lindane treated fish the recovered amount followed the order; remaining parts> viscera > gills muscles. During the depuration period, carbofuran residues taken up by fish were eliminated in 2 phases, an initial rapid phase followed by a slower gradual one. However, the rate of elimination in case of lindane was much slower especially during the first 2 days. At the end of the depuration period (8 days), the muscles (edible portion) contained 10% and 58% of "1"4 C -activity in case of carbofuran and lindane treated ...
The effect of nutrition on reproductive performance was studied in a series of experiments using two models. Increased supply of nutrients was based on feeding lupin grain as a supplement and measurements of testicular growth or ovulation rates were used to measure reproductive characteristics. Purified sources of protein and energy were provided to determine the macronutrient(s), supplied with lupin feeding, responsible for initiating increases in testicular growth and ovulation rate. Increases in both of these parameters were closely related to the supply of additional energy but not protein. The production of acetate and glucose resulting from supplementary feeding with 750 g lupins/d was measured using infusions of "1"4C tracers. Subsequently, infusions of glucose and acetate (individually and in combination) were found to produce similar increases in ovulation rate to those measured in ewes receiving lupins. It was concluded that effects of nutrition on ...
To estimate of the dispersion trend of 3H and 14C discharged from the Wolsung Nuclear Power Plants, the present level of 3H and 14C in environmental samples in the vicinity of the Wolsong site was studied. Tree-ring cellulose analyses were carried out for retrospective evaluation of 3H and 14C in the environment around the Wolsong Nuclear Power Plants. 3H released from the Wolsong Nuclear Power Plants has affected an area up to a 25-km radius from the site, while almost all 14C was deposited within a 2-km radius, reaching to a natural level over 2 km. Organically bound tritium concentrations in tree rings were strongly correlated with the gaseous tritium discharge rate, while delta14C (excess) in tree rings ranged from 204 per thousand to 460 per thousand, which did not ...
Rats from an inbred Sprague-Dawley strain were fed semisynthetic diets with a low (0.3 energy percent (en %)), normal (3 en %) or high (10 en %) content of essential fatty acids (EFA) for at least three generations. Twenty-nine- to 33-day-old male rats were given a single intragastric dose of (1-14C)linoleic acid in olive oil, and the respiratory CO2, urine and feces were collected for 46 hours (expt 1) or 20 hours (expt 2). The 14C activity in respiratory CO2, feces, urine and the carcass was determined in both experiments. In experiment 2 it was also measured in samples of the brown fat, liver, adrenals, white fat, skeletal muscles and brain. In both experiments the rats fed the low EFA diet retained significantly more 14C activity than the rats fed the normal or high EFA diets. In all groups the concentration of label was highest in the brown fat and the ...
The placental transfer of a single intravenous injection of 14C-hexoprenaline was studied in eight pregnant New Zealand white rabbits. Maternal and fetal blood was sampled intermittently for 60 minutes after the injection. An initial rapid decrease in the levels of 14C-hexoprenaline in maternal blood was followed by a second slower phase, whereas fetal levels remained insignificant. The conclusion, therefore, is that the rapid improvement in fetal heart rate after the administration of a single maternal intravenous injection of hexoprenaline in the treatment of fetal distress is due to the action on the uterus and/or on maternal cardiovascular function, and not to direct stimulation of the fetus.
The placental transfer of a single intravenous injection of 14C-hexoprenaline was studied in eight pregnant New Zealand white rabbits. Maternal and fetal blood was sampled intermittently for 60 minutes after the injection. An initial rapid decrease in the levels of 14C-hexoprenaline in maternal blood was followed by a second slower phase, whereas fetal levels remained insignificant. The conclusion, therefore, is that the rapid improvement in fetal heart rate after the administration of a single maternal intravenous injection of hexoprenaline in the treatment of fetal distress is due to the action on the uterus and/or on maternal cardiovascular function, and not to direct stimulation of the fetus.
This study in human volunteers was designed to compare the retention of diethylenetriaminepentaacetic acid (DTPA) in the body after intravenous (i.v.) injection with that following inhalation by using a /sup 14/C labelled tracer. After i.v. injection retention in the blood could be described by three exponential components with half-times of about 1.4 min (approx. 60%). By 24 Ehr more than 99% of the /sup 14/C-DTPA had been excreted in the urine and less than 0.5% remained in the plasma. After inhalation of /sup 14/C-DTPA retention in the lungs could be represented by a single component with a half time of about 75 min. As a consequence the length of time that a therapeutically useful amount of DTPA is retained in the body is approximately twice that following intravenous injection.
Labelling of "1"4C-M-ISP and its absorption, translocation and distribution in peanut and soybean seedling were studied. The results of experiments showed that the radioactive substance could be translocated in xylem and phloem of two kinds of plants. The root of peanut seedling absorbed "1"4C-M-ISP from the nutrient solution more strong than the root of soybean seedling did. After leaf treatment with "1"4C-M-ISP, the soybean seedling absorbed more radioactive substance than peanut seedling did. But the translocation's speed of radioactive substance in pnloem of two kinds of plants were similar.
The elastic and inelastic scattering of "1"4C at 51 MeV from targets of "4"0Ca, "5"6Fe, "6"0Ni, "6"6Zn and "8"8Sr has been measured using a Q3D spectrometer. The "1"4C-nucleus potentials have been derived by optical-model analysis of the observed elastic scattering; the inelastic scattering differential cross sections were interpreted in the distorted-wave Born approximation and also in the coupled-channels approach. The analysis yields "1"4C-nucleus potentials that closely resemble "1"2sup(,)"1"3C and "1"6O potentials. (orig.).
The cause of the Gulf War Syndrome may be related to soldiers being exposed to insecticides (e.g., permethrin (P)), insect repellents (e.g., N,N-diethyl-m-toluamide (DEET)), an organophosphate nerve agent simulant (e.g., diisopropyl fluorpohosphate (DFP)), and/or prophylactic treatment (e.g., pyridostigmine bromide (PB)) against potential nerve gas attacks. The purpose of this study was to assess the dermal disposition of [14C]permethrin in ethanol or ethanol:water (3:2) in the isolated perfused porcine skin flap (IPPSF) model with simultaneous dermal exposure to DEET or DFP. These IPPSFs were also simultaneously perfused arterially with or without PB, DFP, or DFP + PB. The results indicated that DFP + PB significantly increased [14C]permethrin absorption compared to controls (1.06% dose vs 0.14% dose). PB significantly increased [14C]permethrin disposition in ...
It was shown that the incorporation of "1"4C-linoleic acid in cerebrosides of normal and psoriatic human skin is different. In psoriatic epidermis and corium the turnover of this fatty acid is significantly elevated. It is suggested that in psoriasis the epidermal cell is not able to build up a regular carbohydrate sequences of lipids because the false carbohydrate chain activates the degradation of glycolipids and in compensating for the increased degradation raises the synthesis rate of glycolipids. (orig./MG).
To understand the environmental dispersion trend of "3H and "1"4C discharged from the Wolsung nuclear power plant, the present levels of "3H and "1"4C in environmental samples in the vicinity of the Wolsong site were studied. During 1992 through 2002, the annual means of HTO and "1"4C concentrations in air collected at three sampling stations around Wolsong nuclear power plant were in the range of 1.13 #approx# 29.2 Bq m"-"3 and 0.33 #approx# 0.40 Bq g-C"-"1 respectively, decreasing with distance from the site. The annual mean of TFWT concentrations in pine needle was in the range of 104 #approx# 790 Bq L"-"1 at N-1 and 62.8 #approx# 298 Bq L"-"1 at S"-"2, while the annual mean of "1"4C concentration was in the range of 0.335 #approx# 0.897 g-C"-"1 at N-1 and 0.254 #approx# 0.332 Bq g-C"-"1 #approx# at S"-"2, showing elevated value than a 0.25 Bq g-C"-"1 of background level. (author)
Following the publication (Stenhouse and Baxter, Nature; 267:828 (1977)) of the levels of bomb "1"4C and the residence times of carbon in the human body, excess radiation burdens from this radioisotope are evaluated under the assumption that no radiation dose, however small, can be regarded as entirely harmless biologically. The estimated annual absorbed dose attributable to "1"4C both natural and man-made for 1953-1973 and similar predicted figures for 1975-2025 are shown graphically. The cumulated doses to gonads (over 30 yr) and to bone marrow and bone-lining cells (over 60 yr) and also estimates of the biological damage to reproductive cells from "1"4C #beta#-irradiation (30 yr accumulated dose) are presented. It is concluded from both genetic and somatic considerations, that the potential human radiation burden due to artificially produced "1"4C calculated using the assumptions stated is certainly significant and, therefore, cannot be dismissed. However, relative to the world ...
To assess the internal dose by {sup 3}H and {sup 14}C in total diet of inhabitants near Wolsung nuclear power plants, TFWT, OBT and {sup 14}C concentration in total diet was analyzed for collection region and time. TFWT, OBT and {sup 14}C concentrations were in the range of 3.19-42.2 Bq/L, 1.00-39.4 Bq/L, and 0.230-0.856 Bq/gC, respectively. The calculated annual effective dose with TFWT, OBT and {sup 14}C is 6.10 x 10{sup -5} mSv/y, 3.71 x 10{sup -5} mSv/y and 7.08 x 10{sup -3} mSv/y, respectively. And then annual internal dose with total diet for inhabitants near Wolsung NPPs is about 7.18 x 10{sup -3} mSv/y, which is about 0.72% of annual effective dose limit 1 mSv/y.
To assess the internal dose by 3 H and 14C in total diet of inhabitants near Wolsung Nuclear Power Plants, TFWT, OBT and 14C concentration in total diet was analyzed for collection region and time. TFWT, OBT and 14C concentrations were in the range of 3.19-42.2 Bq/L , 1.00-39.4 Bq/L, and 0.230-0.856 Bq/gC, respectively. The calculated annual effective dose with TFWT, OBT and 14C is 6.1010 -5 mSv/y, 3.7110 -5 mSv/y and 7.0810 -3 mSv/y, respectively. And then annual internal dose with total diet for inhabitants near Wolsung NPPs is about 7.1810 -3 mSv/y, which is about 0.72% of annual effective dose limit 1 mSv/y.
To assess the internal dose by "3H and "1"4C in total diet of inhabitants near Wolsung nuclear power plants, TFWT, OBT and "1"4C concentration in total diet was analyzed for collection region and time. TFWT, OBT and "1"4C concentrations were in the range of 3.19-42.2 Bq/L, 1.00-39.4 Bq/L, and 0.230-0.856 Bq/gC, respectively. The calculated annual effective dose with TFWT, OBT and "1"4C is 6.10 x 10"-"5 mSv/y, 3.71 x 10"-"5 mSv/y and 7.08 x 10"-"3 mSv/y, respectively. And then annual internal dose with total diet for inhabitants near Wolsung NPPs is about 7.18 x 10"-"3 mSv/y, which is about 0.72% of annual effective dose limit 1 mSv/y.
To assess the internal dose by 3 H and 14C in total diet of inhabitants near Wolsung Nuclear Power Plants, TFWT, OBT and 14C concentration in total diet was analyzed for collection region and time. TFWT, OBT and 14C concentrations were in the range of 3.19-42.2 Bq/L , 1.00-39.4 Bq/L, and 0.230-0.856 Bq/gC, respectively. The calculated annual effective dose with TFWT, OBT and 14C is 6.1010 -5 mSv/y, 3.7110 -5 mSv/y and 7.0810 -3 mSv/y, respectively. And then annual internal dose with total diet for inhabitants near Wolsung NPPs is about 7.1810 -3 mSv/y, which is about 0.72% of annual effective dose limit 1 mSv/y.
The kinetics of {sup 14}C-photosynthate import by developing wheat grains was followed after pulse-labeling the flag leaf with {sup 14}CO{sub 2}. Samples were collected from four successive points along the transport pathway to and within the grain: exuding aphid stylets on the peduncle, exuding grain pedicels, the grain crease tissues, and the liquid contents of the endosperm cavity. In addition, microautoradiographs were prepared of the grain crease tissues during movement of the {sup 14}C pulse into the grain. At all times, sucrose accounted for 93 to 97% of the total {sup 14}C present at all four sampling sites. The main features of the {sup 14}C kinetics could be accounted for by a simple compartmental model consisting of sucrose pools in series. Microautoradiographs of the crease tissues showed fairly uniform ...
"1"4C measurement uses a number of standards and reference materials with different properties. Historically the absolute calibration of "1"4C measurement was tied to 1890 wood, through the 'primary' standard of NBS-OxI (produced by the National Bureau of Standards, now NIST - National Institute of Standards and technology) subsequently replaced by NBS-OxII. These are both internationally calibrated and certified materials, whose "1"4C activities are known absolutely. A second tier of materials, often called secondary standards or reference materials, and including internationally recognised materials such as ANU-sucrose (now also IAEA-C6), Chinese - sucrose and the IAEA C1-C6 series, augmented by additional oxalic acid samples are also used routinely. The activity of these materials has been estimated from large numbers of measurements made by many laboratories. Recently, further natural materials from the Third and Fourth International Radiocarbon Inter-comparisons (TIRI and FIRI) ...
Hydrolyzates of tissues that had been labeled with (14C)proline often contain significant amounts of cis-4-hydroxy(14C)proline. Since animal cells do not contain an enzyme which can effect formation of cis-4-hydroxyproline, there are only two possible explanations for its presence. Either it is formed during acid hydrolysis of trans-4-hydroxyproline (which is synthesized by cells and is a common constituent of connective tissues), or it is produced by a nonenzymatic mechanism such as attack by oxygen radicals. It is important to resolve this issue because if a nonenzymatic mechanism is active in connective tissues, then it will be necessary to reevaluate currently accepted ideas about production of hydroxyproline. This communication describes a method for distinguishing between the two alternate explanations. Tissues or cells are labeled with (14C)proline, and ...
Hydrolyzates of tissues that had been labeled with [14C]proline often contain significant amounts of cis-4-hydroxy[14C]proline. Since animal cells do not contain an enzyme which can effect formation of cis-4-hydroxyproline, there are only two possible explanations for its presence. Either it is formed during acid hydrolysis of trans-4-hydroxyproline (which is synthesized by cells and is a common constituent of connective tissues), or it is produced by a nonenzymatic mechanism such as attack by oxygen radicals. It is important to resolve this issue because if a nonenzymatic mechanism is active in connective tissues, then it will be necessary to reevaluate currently accepted ideas about production of hydroxyproline. This communication describes a method for distinguishing between the two alternate explanations. Tissues or cells are labeled with [14C]proline, and ...
Mesocarp tissue from sucrose-accumulating sweet melon (Cucumis melo cv. Galia) showed sucrose synthase activity (ca 1 nkat/gfw) while soluble acid invertase and sucrose phosphate synthase activities were not observed. Sucrose uptake into mesocarp discs was linear with sucrose concentration (1-500 mM) and unaffected by PCMBS and CCCP. Sucrose compartmentation into the vacuole also increased linearly with sucrose concentration as indicated by compartmental efflux kinetics. Mesocarp discs incubated in /sup 14/C-fructose + UDP-glu synthesized /sup 14/C-sucrose and efflux kinetics indicated that the /sup 14/C-sucrose was compartmentalized. These data support the hypothesis that two mechanisms are involved in sucrose accumulation in sweet melon: (1) compartmentation of intact sucrose and (2) synthesis of sucrose via sucrose synthase and subsequent compartmentation in ...
For the first time a comprehensive level and decay scheme has been obtained for a T=(5/2) nucleus in the s-d shell ("2"7Na) by using a radioactive beam and target. Particle-#gamma# and p-#gamma#-#gamma# coincidences were measured following the "1"4C("1"4C,p#gamma#)"2"7Na reaction at E_l_a_b=22 MeV. The results do not support an inversion of the 2s_1_/_2 and 1d_5_/_2 orbitals, as previously proposed for T_z#>=#3, but they do suggest an increased N=16 gap between the 2s_1_/_2 and 1d_3_/_2 orbitals due to the neutron excess. A consistent interpretation of the level scheme in terms of the s-d shell model using the USD Hamiltonian is possible below 4 MeV, but differences increase at higher excitation energies. Another interpretation is that the influences of both the p_1_/_2 and f_7_/_2 intruder orbitals increase simultaneously with increasing T, an effect not included in the USD Hamiltonian.
1. Rates and rate coefficients of glucose utilization and replacement were determined with [5-3H]- and [U-14C]-glucose in rats starved for 24h, either conscious or under halothane anaesthesia, in a...Full Text Available
After treatment with NN-di[14C]methylnitrosamine, samples of DNA were isolated from rat livers by a conventional phenol procedure and examined for the presence of phosphotriesters. A method of capable...Full Text Available
Degradation of "1"4C terbufos was studied under greenhouse conditions. A mixture of "1"4C labelled compound (2.48 x 10"4 Bq of O-ethyl-1- "1"4C) und unlabelled compound (0.09 g of the granule formulation Counter 10 G) was applied to pots containing 750 g of sandy loam clay Ultisol soil with 4.9% organic matter and a cation exchange capacity of 7.6. Two treatments were established, one where maize (cultivar Cristiani) was grown and the other without plants. The soil and plants were extracted at 0, 4, 8, 16, 32 and 64 days and analyzed by a liquid scintillation counter, gas chromatography-flame photometric detector (GC-FPD) and autoradiography. The total "1"4C compounds extracted on day 64 were 31 #+-# 5.6% of the radioactivity applied in the treatments with plants and 46.1 #+-# 1.1% without plants. From the autoradiography results it can be concluded that all times the compounds identified by this technique were terbufos, terbufos sulphoxide and terbufos sulphone. These results will be ...
The acute effects of injections of the human growth hormone-like factor purified from plerocercoids of the tapeworm Spirometra mansonoides on carbohydrate, lipid, and protein metabolisms were determined in intact rats. Male rats were injected ip with saline, insulin, or various doses of partially purified PGF. The rats injected with insulin had significantly reduced serum glucose concentrations but no dose of PGF caused a change in serum glucose levels. Insulin and PGF stimulated [14C]glucose and [14C]leucine oxidation to 14CO2 in adipose tissue and muscle and increased incorporation of both [14C]glucose carbons into lipids and [14C]leucine into protein in fat and muscle. The responses to PGF were dose-dependent and persisted after 3 hr of incubation in vitro. Injections of naloxone prior to injecting PGF to block the ...
The suprachiasmatic nucleus (SCN) of the hypothalamus is thought to play a critical role in circadian rhythm generation and entrainment to the light/dark cycle. In adult rats, the SCN shows a circadian...Full Text Available
1 The plasma protein binding of theophylline was determined after addition of [14C]-theophylline (15 micrograms/ml) to plasma from 24 healthy drug-free volunteers and equilibrium dialysis for 2 h at...Full Text Available
The basic approach to radioactive labeling techniques in hemoglobin identification consists of mixing 14C labeled normal carrier globin with 3H labeled unknown globin and carrying out the subsequent separations and purifications looking at the distribution of 3H and 14C radioactivity. This technique was devised to ascertain the amino acid substitution in Hb Indianapolis and was instrumental in solving the structure of Hb Vicksburg. It was also useful in determining the purity of gamma-chains from cultures of human and baboon erythroid progenitors. Another use of this technique would be in identifying aberrant peaks of radioactivity in chain separation chromatograms, such as ''pre-peaks''.
We operate a new NEC 250kV single-stage accelerator mass spectrometer (SSAMS) next to our established 5MV tandem. This permits good comparison of 14C-AMS and challenges SSAMS performance. Initial SSAMS ion-optical deficiencies have been addressed by shimming the injection magnet and 3permil 14C/13C measurement with background limited by sample chemistry is routine. Higher-precision analysis is also achievable. A problematic measurement interference remains, however. The small spectrometer was procured to add measurement capacity, and for experiments with positive ions, but is now the preferred instrument for both convenience and measurement quality.
At the Savannah River Site (SRS), nuclear production reactors used de-ionizers to control the chemistry of the reactor moderator during their operation to produce nuclear materials primarily for the weapons program. These de-ionizers were removed from the reactors and stored as a legacy waste with no path to disposal due to the relatively high 14C contamination (i.e., on the order of 20 curies per de-ionizer for 48-50 de-ionizers) and the low disposal limit of 4.2 Ci previously established for the Intermediate Level Vault (ILV). The ILV is considered most appropriate facility within which to dispose these items due to the method of solidifying waste items with cementitious material inside concrete vaults. In previous analyses the 14C ILV disposal limit was established at 4.2 Ci resulting from the use of a very conservative method to analyze the dose received from atmospheric releases of gaseous ...
PAH biomineralization measurements of yardwaste compost samples indicated heterogeneous distribution of active microorganisms and substantial sequestration of the non-polar substrate in the compost matrix. - The purpose of the study was to evaluate the potential of phenanthrene and fluoranthene biodegradation in yardwaste compost materials. These polynuclear aromatic hydrocarbons were chosen for this work because they are relatively readily biodegradable and ubiquitous in the environment. Compost samples were incubated in biometers with "1"4C-labeled phenanthrene and the evolution of "1"4CO_2 was assessed as a measure of mineralization. The "1"4CO_2 evolution varied widely among replicate biometers, possibly as the result of (1) uneven and patchy colonization of phenanthrene-degrading microorganisms on compost particles, and (2) non-uniform dispersion of the labeled substrate spike into the yardwaste microenvironment. Mineralization of phenanthrene reached about 40% extent of "1"4CO_2 ...
Epididymal adipocytes, isolated from rats pretreated with (/sup 14/C)-2,4,5,2',4',5'-hexachlorobiphenyl (6-CB), were utilized to examine the relationship between the mobilization of lipid and 6-CB and to determine whether 6-CB was differentially associated with subcellular organelles over time as has been demonstrated for newly synthesized lipid. Lipolysis, depleted approximately 1% of total cellular triacylglycerols (TG) regardless of time from treatment with 6-CB. The percentage of cellular 6-CB released from adipocytes to incubation buffer infranatants was not correlated with the magnitude of lipolysis produced over the 50-min incubation period; nor was the percentage of 6-CB released to the buffers correlated with the length of the incubation period, regardless of the presence of ISO. Although adipocytes responded similarly to lipolytic stimuli independent of time (days) since 6-CB treatment, significant decreases ...
Metabolism of benzene is thought to be necessary to produce the toxic effects, including carcinogenicity, associated with benzene exposure. To extrapolate from the results of rodent studies to potential health risks in man, one must know how benzene metabolism is affected by species, dose, dose rate, and repeated versus single exposures. The purpose of our studies was to determine the effect of repeated inhalation exposures on the metabolism of [14C]benzene by rodents. Benzene metabolism was assessed by characterizing and quantitating urinary metabolites, and by quantitating 14C bound to hemoglobin and micronuclei induction. F344/N rats and B6C3F1 mice were exposed, nose-only, to 600 ppm benzene or to air (control) for 6 hr/day, 5 days/week for 3 weeks. On the last day, both benzene-pretreated and control animals were exposed to 600 ppm, 14C-labeled benzene for ...
The release of {sup 14}C as {sup 14}CO{sub 2} from partly failed spent fuel containers has been analyzed by the flow of gases into and out of the containers. This flow of gases is driven by pressure differences, which are in turn caused by heating by the spent fuel. In this analysis, the timing and size of holes in the containers are assumed to be given. A better means of predicting the time distribution and sizes of penetrations in nuclear waste containers is needed. For the purposes of far-field transport calculations, we have adopted release rates that are shown to be bonding for the large range of hole sizes studied. The transport of released {sup 14}CO{sub 2} has been analyzed by transport in equivalent porous medium. The peak {sup 14}CO{sub 2} concentration in pore gas at 350 m above the repository does not depend on the time of hole occurrence, although the time of penetration obviously affects the arrival and duration of exposure to ...
This study sought to quantitate lidocaine's interaction with alpha-1-acid glycoprotein (AAG), human serum albumin (HSA), and AAG in the presence of HSA, and to determine the extent of displacement of lidocaine from its binding site(s) by selected cardiovascular drugs (dipyridamole, disopyramide and quinidine). Since the limited experimental work reported in this area has involved the use of a single lidocaine concentration, this study involved the evaluation of a range of lidocaine concentrations. Lidocaine interaction with plasma proteins (AAG and HSA) was studied at 37/sup 0/C using an isothermal equilibrium dialysis system and /sup 14/C-lidocaine HCl. A dialysis membrane (M.W. cutoff 12,000 to 14,000) separated the two chambers of each dialysis cell. The extent of /sup 14/C-lidocaine dialysis was studied with respect to both drug and protein concentrations. Aliquots of each chamber of each ...
Local cardiac glucose utilization (LCarGU) was quantified in the rat heart according to the Sokoloff model and local cardiac blood flow (LCarBF) according to the /sup 14/C-iodoantipyrine method. For quantitative autoradiography calibration curves for heart slices were performed. They differed from the brain calibration curves by 8%. The lumped constant was 0.377 in isolated working hearts. LCarGU and LCarBF could then be quantified in awake rats. At different locations mean LCarGU of different hearts varied from 85 to 200 ..mu..moles/100g/min and mean LCarBF from 390 to 831 ml/100g/min. The ratio subendocardial/subepicardial glucose utilization or blood flow was not systematically different from 1. The results indicate that glucose can be an important fuel in the heart of the awake rat, although its contribution to overall metabolism varies from animal to animal.
Results from three separate experiments that have some relevance to bound residues are reported. In the first, "1"4C-labelled paraquat was lost when applied to soil in the field, about 26% of the radioactivity disappearing in 15 months, whereas in laboratory incubation studies there was no loss of radioactivity in one year. Two possible explanations are (i) that there was photolytic decomposition in the field, (ii) the preparation of the soil for the laboratory study upset the microbial ecology of the soil to the detriment of organisms that can degrade paraquat. In an experiment with "1"4C-labelled isoproturon, there was an indication that there was slightly more "1"4C in the unextractable humin fraction in soil in which wheat plants were grown than in bare soil. Work in the UK, Federal Republic of Germany and in Switzerland has shown that the phytotoxicity of residues of atrazine, carbetamide, chloridazone, propyzamide, simazine, lenacil, monolinuron, linuron, propachlor and ...
Peanut grains (1500g) were placed in a jute sack which was sprayed with "1"4C- pirimiphos-methyl [0-2-diethylamino-6-methylpyrimidin-4-yl-O, O-dimethylphosphorothiate, "1"4C-labelled in the 2-position of the pyrimidine ring]; total dose 5.55 MBq + 22.5 mg cold insecticide. As in practice, the sack was stored under local conditions for 36 weeks. The grain was crushed, dried at 50 deg. C for 2 hours and soxhlet extracted with chloroform-methanol (1:1). The crude oil was then subjected to sequential processes of alkali treatment, bleaching and deodorization. The initial residue concentration in the crude oil (5.66 ppm) was reduced to 4.50 ppm through alkali treatment and declined further to 3.78 ppm after bleaching. Deodorization removed a substantial amount of "1"4C-residues leaving 1.35 ppm in the refined oil. It may be concluded that simulated commercial processing of crude oil were capable of removing 76% of pirimiphos-methyl and/or products. The most efficient process was ...
The effect of butylated hydroxytoluene (BHT) pretreatment (0.5% in the diet for 10 days) on the excretion, tissue distribution and DNA binding of orally administered (/sup 14/C)aflatoxin B1 (AFB1) was determined in male Fischer F344 rats. The amount of radioactivity excreted in the urine and feces by 24 hr was higher in BHT-treated rats than in controls. Treatment with BHT enhanced the excretion of water-soluble metabolites in the urine and in the large intestines plus feces at the earlier sampling times. The amount of radioactivity bound to hepatic nuclear DNA was six times less in the BHT-pretreated rats than in controls 6 hr after administration of the isotope. The half-lives of (/sup 14/C)DNA in the rat liver were 30 and 46 hr for control and BHT-pretreated rats, respectively. These results indicate that BHT pretreatment may protect the animal from the carcinogenic effects of AFB1 by enhancing the ...
Investigations of sucrose synthase in maize root tips have required development of a means to circumvent the rapid decline of activity observed after extraction dialysis and either synthetic or degradative assays. Several protease inhibitors were tested; although PMSF increased initial activity, no inhibitor prevented the drop in activity with time. Western blot analysis indicated that activity decline was not associated with protein degradation. Therefore, a procedure was developed which (1) shortened extraction-to-assay period from ca. 24 hours to 7 minutes, (2) simplified previous assays and (3) reduced the amount of tissue required. Extract was desalted with spun columns and the {sup 14}C-UDPG product recovered with DEAE ion exchange paper. The minute quantities of product recovered can be concealed by the presence of trace impurities in the {sup 14}C-sucrose utilized. DEAE ion exchange paper was ...
Guard cells rely on import for their supply with reduced carbon. The authors tested by silicone oil centrifugation the ability of guard cell protoplasts to accumulated ({sup 14}C)-sucrose. Uptake rates were corrected after measurement of {sup 14}C-sorbitol and {sup 3}H{sub 2}O spaces. Sucrose uptake followed biphasic kinetics, with a high-affinity component below 1 mM external sucrose (apparent K{sub m} 0.8 mM at 25C) and a low-affinity nonsaturable component above. Uptake depended on pH (optimum at pH 5.0). Variations in the concentrations of external KCl, CCCP, and valinomycin indicated that about one-half of the sucrose uptake rate could be related to an electrochemical gradient across the plasmalemma. Total uptake rates measured at 5 mM external sucrose seem to be sufficient to replenish emptied plastids with starch within a few hours.
Mineralization and volatilization of ring labelled "1"4C-2,4-dichlorophenoxyacetic acid in soil was studied over a period of six weeks under laboratory conditions at 25 deg. C in three different soils collected from three sites, Delhi, Jaipur and Ludhiana. A very slow rate of both mineralization and volatilization was observed in all the three soils. The observed mineralization, was highest for the Delhi soil, 0.93%, followed by the Ludhiana soil, 0.73% and the Jaipur soil 0.14% in 42 days. The extent of volatilization was 0.46% for the Jaipur soil, 0.37% for the Ludhiana soil and 0.32% for the Delhi soil. (author)
This evaluation has for object to inform about the levels in carbon 14 in the environment of the factories of La Hague. Two sectors were differentiated on one hand the terrestrial environment, and on the other hand the marine environment. The investigations concerned first and foremost food products stemming as the vegetable culture (vegetables) or individual breeding (milk, eggs) but also foodstuffs stemming from the local agriculture (cereal). In touch with the second sector, the marine environment, the sampling concerned the accessible products of the sea by all and those locally marketed (fishes, molluscs, shellfishes). The different results are presented in tables. (N.C.)
A method for product analysis that eliminates a problematic step in the radiometric sucrose-phosphate synthase assay is described. The method uses chromatography on a boronate-derivatized high-performance liquid chromatography column to separate the labeled product, (14C)sucrose phosphate, from unreacted uridine 5{prime}-diphosphate-(14C)glucose (UDP-Glc). Direct separation of these compounds eliminates the need for treatment of the reaction mixtures with alkaline phosphatase, thereby avoiding the problem of high background caused by contaminating phosphodiesterase activity in alkaline phosphatase preparations. The method presented in this paper can be applied to many UDP-Glc requiring enzymes; here the authors show its use for determining the activities of sucrose-phosphate synthase, sucrose synthase, and uridine diphosphate-glucose pyrophosphorylase in plant extracts.
1. Novel methods, using L-[ring-2-14C]tryptophan, are described for the measurement of tryptophan 2,3-dioxygenase activity and tryptophan accumulation in isolated rat liver cells. 2. The effects of...Full Text Available
{sup 14}C-Sugar uptake and incorporation into starch by slices of developing maize (Zea mays L.) endosperm were examined and compared with sugar uptake by maize endosperm-derived suspension cultures. Rates of sucrose, fructose, and D- and L-glucose uptake by slices were similar, whereas uptake rates for these sugars differed greatly in suspension cultures. Concentration dependence of sucrose, fructose, and D-glucose uptake was biphasic (consisting of linear plus saturable components) with suspension cultures but linear with slices. These and other differences suggest that endosperm slices are freely permeable to sugars. After diffusion into the slices, sugars were metabolized and incorporated into starch. Starch synthesis, but not sugar accumulation, was greatly reduced by 2.5 millimolar p-chloromercuribenzenesulfonic acid and 0.1 millimolar carbonyl cyanide m-chlorophenylhydrazone. Starch synthesis was dependent on kernel age and incubation ...
Six major use pesticides (Atrazine, Dicamba, Isoproturon, Lindane, Paraquat and Trifluralin) with differing physico-chemical properties were evaluated for the significance of 'bound' or non extractable residue formation. Investigations were carried out in purpose-built microcosms where mineralization, volatilisation, 'soil water' extractable and organic solvent extractable residues could be quantified. Extractable residues were defined as those accessible by sequential extraction where the solvent used became increasingly non-polar. Dichloromethane was the 'harshest' solvent used at the end of the sequential extraction procedure. {sup 14}C-labelled volatilised and {sup 14}CO{sub 2} fractions were trapped on exit from the microcosm. The pesticides were categorised into 3 classes based on their behaviour. (i) Type A (Atrazine, Lindane and Trifluralin) in which ring degradation was limited as ...
Phlorizin is a competitive inhibitor of Na/sup +//glucose symport in animal cells and of H/sup +//3-O-methylglucose (3-O-MeG) symport in liverworts. The effects of this compound on the uptake of (U-/sup 14/C) sucrose and of (/sup 14/C) 3-O-MeG by broadbean (Vicia faba L.) leaf discs were studied. Leaf discs without lower epidermis were preincubated in the dark for 30 min (fresh discs) or for 12 h (aged discs) on a medium buffered at pH 5.0 containing mannitol as an osmoticum. They were then incubated for 30 min in the light on a similar solution added with 1 mM (/sup 14/C) sucrose or (/sup 14/C) 3-O-MeG and 5 mM phlorizin. Phlorizin inhibited uptake of 3-O-MeG by 37 and 50% respectively in fresh and aged discs. Sucrose uptake was more sensitive to the inhibitor than 3-O-MeG uptake and was also more inhibited in aged than ...
Assimilation and metabolism of /sup 14/CO/sub 2/ was compared to that of (U-/sup 14/C) sucrose in young grapefruit (ca 25 mm diameter) to determine their respective roles in fruit growth. Fixation of /sup 14/CO/sub 2/ by isolated fruit tissues during 10 min in light exceeded that in dark by 2- to 30-fold depending on tissue content of chlorophyll. Greatest apparent photosynthesis occurred in outer green peel, but green juice tissues assimilated more than did adjoining inner peel tissue. In the dark, juice tissues incorporated 2.5-fold more /sup 14/CO/sub 2/ than any other tissue. Neutral sugars accounted for a smaller proportion and organic acids, a greater proportion, of the /sup 14/C-assimilates in interior peel and juice tissues. These data suggest more extensive production of organic acids from /sup 14/CO/sub 2/ in tissues isolated from the fruit interior. In contrast, little difference among ...
A microemulsion comprised of water, Brij 78, pentanol and styrene into which PPO and bis-MSB had been dissolved was prepared. Polymerization of the styrene resulted in a suspension of fluor-containing polystyrene nanoparticles (<100 nm). After a concentration step, the aqueous nanosuspension was able to detect {sup 14}C with counting efficiencies over 50% of those of a commercially available scintillation cocktail. Monte Carlo calculations demonstrated that the size and concentration of the nanoparticles were appropriate for optimum detection efficiency.
Following tuber excision from the mother plant sucrose synthase activity fell from 3,120 to 960 nmol/g.f. wt./h within 7 days and starch synthesis ({sup 14}C sucrose incorporated into isolated discs) from 23 to 7 nmol/g.f. wt./h. While the maximum catalytic activity of sucrose synthase was more than sufficient to account for the observed rate of starch synthesis a maximum of 27% of sucrose incorporated by discs was converted into starch within 3 h. This compared with 80% conversion of {sup 14}C glucose incorporated. Tuber excision also reduced the rate of starch biosynthesis with glucose as a substrate (from 206 to 64 nmol/g.f. wt./h). The activities of UDPG-pyrophosphorylase, PPi-PFK, ATP-PFK, starch synthase and hexokinase (glucose or fructose substrates) were unaffected by tuber removal. ADPG pyrophosphorylase activity was reduced from 8,000 to 4,500 nmol/g.f. wt./h. Preliminary experiments indicate ...
Dynamics and metabolism of sugars translocated into the fruit region were investigated in tomato using {sup 14}C-labelled compounds. The translocation substance in tomato is thought to be sucrose, but the amount of sucrose in its fruit is very small. Therefore, the degradation of sucrose in the fruit and its translocation to the fruit was investigated. The sucrose was digested into hexoses such as glucose, fructose, etc. and the degradation rate was considerably low. In the stage of thickening growth, sucrose was more extensively converted into other substances except for sugars compared with the coloring stage. Then, {sup 14}C-labelled fructose was given through its gynophore to investigate the degree of reproduction to sucrose. The fructose level in the fruit reached the platean by 48 hrs after the addition and gradually decreased. The radioactivities were detected in sugars, organic acids and other ...
The persistence and binding of the insecticide in soil and its residual effect in tomato plant were studied under green house conditions using "1"4 C -labelled chemical. When the insecticide was applied topically on tomato plant, its residues were detected in different plant parts; the amounts of which varied according to the mode of application and time of sampling. At the end of the experimental period (45 days) about 10% of the applied dose was recovered in the aerial parts of the plant following foliar application as compared with 2.4% recovery after soil application. Soil application of lindane led to higher residual content in the fruits than foliar application. The insecticide was also found to dissipate than to leach to lower soil horizons and was confined to the upper layers with no pronounced degradation capacity. Time to 50% disappearance (Dt_5_0 value) for lindane was estimated to be 18 days. 1 fig., 3 tabs.
Safety studies related to the disposal of low- and intermediate waste indicate that the long term risk is determined by the presence of long-lived nuclides such as "1"4C, "5"9Ni, "6"3Ni, "9"9Tc, "1"2"9I and the transuranium elements. As most of these nuclides are difficult to measure, the correlation between these critical nuclides and some other easily measurable key nuclides such as "6"0Co and "1"3"7Cs has been investigated for typical waste streams of Paks Nuclear Power Plant (Hungary) and scaling factors have been proposed. An automated gamma-scanning monitor has been purchased and calibrated to determine the gamma-emitting radionuclides. Radiochemical methods have been developed to determine significant difficult-to-measure radionuclides. The radionuclides of interest have been "3H, "1"4C, "9"0Sr, "5"5Fe, "5"9Ni, "9"9Tc, "1"2"9I and TRUs. The measurements taken so far have revealed brand new information and data on radiological composition of waste of WWER-type reactors. The ...
Neutron-rich He-, Li-, and Be-isotopes in the vicinity of the drip-line have been studied by "1"2C- and "1"4C-induced multi-nucleon transfer reactions on "1"0Be and "1"3","1"4C-targets. This study revealed unknown excited states in "8","1"0He, "1"0","1"1Li and in "1"3","1"4Be. Both excitation energies and widths have been measured. In some cases most probable spins and parities could be assigned to the particle-unstable states observed. (orig.).
The ability of the Packard 2000 CA/LL liquid scintillation counter to reduce background count rates relies on pulse shape/duration analysis in which short duration organic scintillation events are discriminated from longer duration non-quenchable background events. A consequence of this is a loss in the counting efficiency. The results of this investigation indicate that much of the lost efficiency can be regained by sharpening the true #beta#"- pulse widths via the use of different scintillant combinations and by certain counter modifications. (author).
Radioactive "1"4C sucrose was found to be an ideal marker for microleakage because it did not penetrate tooth tissue, dental cement, or mounting resin. The main finding is that the adhesive cements--the glass-ionomer and polycarboxylate--are significantly more effective at preventing microleakage than are the traditional phosphate cements--silicate and zinc phosphate. The differences can be as high as two orders of magnitude. The adhesive cements provide almost perfect and reliable seals. By contrast, the nonadhesive cements are erratic sealants with most of the restorations leaking.
An on-going inter-comparison programme which is focused on assessing and establishing consensus protocols to be applied in the identification, selection and sub-sampling of materials for subsequent "1"4C analysis is described. The outcome of the programme will provide a detailed quantification of the uncertainties associated with "1"4C measurements including the issues of accuracy and precision. Such projects have become recognised as a fundamental aspect of continuing laboratory quality assurance schemes, providing a mechanism for the harmonisation of measurements and for demonstrating the traceability of results. The design of this study and its rationale are described. In summary, a suite of core samples has been defined which will be made available to both AMS and radiometric laboratories. These core materials are representative of routinely dated material and their ages span the full range of the applied "1"4C time-scale. Two of the samples are of wood from the German and Irish ...
Up to now the retention of radioactive material for nuclear facilities has been based on the maximum individual dose. The maximum individual dose can locally be lowered considerably by higher dissolution. In general, the collective doses are not lowered by this. In order to set up regulations concerning collective doses, the new recommmendations of the ICRP are very welcome. However, the costs of detriment and the period to be considered have not yet been defined. Therefore there are no fixed methods for carrying out a cost-benefit analysis. Furthermore, for nuclear technology the costs and the effectiveness of the retention of radioactive material for non-realized facilities can only be quoted roughly, which makes a cost-benefit analysis more difficult. A cost-benefit analysis for the retention of radioactive material in nuclear power plants with LWRs and reprocessing plants of the PUREX process has been carried out with best estimate data. The results show that the development of ...
Full text: Many factors including drug efficacy, compliance and antibiotic resistance may influence HP eradication rates. The "1"4C urea breath test is a sensitive method of confirming HP colonisation and eradication. The aim was to study the relationships between the peak "1"4CO_2 counts on the breath test prior to treatment, smoking and HP eradication, and to assess if persistent or recurrent symptoms implied failure of eradication. 117 patients with DU and HP colonisation proved on biopsy or rapid urease test who underwent "1"4C urea breath tests at least one month after eradication treatment was ceased were studied (69 male, 48 female, mean age 41, range 26-87 y). Questionnaire assessment of treatment regimen, smoking history and dyspeptic symptoms was made at the time of the breath test. A sub-group of 43 patients who had pre- and post-treatment breath tests was studied to assess if high peak "1"4CO_2 counts on the pre-treatment breath test related to treatment success. The mean ...
Dunaliella salina cells were pulse-labeled for 2 min with (/sup 14/C)palmitic acid, (/sup 14/C)oleic acid, or (/sup 14/C)lauric acid in order to trace the pathway of galactolipid biosynthesis and desaturation. Through the use of high performance liquid chromatography it was possible to follow the movement of radioactivity through many individual molecular species of monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) for periods of 24 h and, in some cases, as much as 120 h. Analysis of the fatty acid fluxes permitted us to refine current views regarding biosynthesis of the predominantly prokaryotic galactolipids. The initial D. salina MGDG molecular species, containing paired oleate and palmitate (18:1/16:0), can follow two metabolic routes. If the palmitoyl chain is desaturated to 16:1, the resulting 18:1/16:1 MGDG is subject to rapid ...
["1"4C]Cadaverine was applied to leaves of Lupinus polyphyllus, L. albus, L. angustifolius, L. perennis, L. mutabilis, L. pubescens, and L. hartwegii and it was preferentially incorporated into lupanine. In Lupinus arboreus sparteine was the main labelled alkaloid, in L. hispanicus it was lupanine. A pulse chase experiment with L. angustifolius and L. arboreus showed that the incorporation of cadaverine into lupanine and sparteine was transient with a maximum between 8 and 20 h. Only leaflets and chlorophyllous petioles showed active alkaloid biosynthesis, whereas no incorporation of cadaverine into lupanine was observed in roots. Using in vitro organ cultures of Lupinus polyphyllus, L. succulentus, L. subcarnosus, Cytisus scoparius and Laburnum anagyroides the inactivity of roots was confirmed. Therefore, the green aerial parts are the major site of alkaloid biosynthesis in lupins and in other legumes. (orig.).
Since 1999, several studies on nuclear fuels were realised in C11/C12 Atalante Hot Cell. This paper presents firstly an overview of the apparatus used for fuel dissolution and characterisation like reactor design, gas trapping flask and solid/liquid separation. Then, the general methodology is described as a function of fuel, temperature, reagents, showing for each step, the reachable experimental data: Dissolution rate, chemical and radiochemical fuel composition including volatile LLRN, insoluble mass, composition, morphology, cladding chemical, radiochemical and physical characterisation using SIMS (made in Cadarache/LECA facilities), MEB. To conclude, some of the obtained results on 129I and 14C composition of oxide fuels, rate of dissolution and first results on dissolution studies of RERTR UMo fuel will be detailed. (Author)
The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materals in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 ...
Antibodies to hemoglobin have been studied with a radioimmunoassay which employs ["1"4C]carbamylated (= carbamoylated) hemoglobin S. An antiserum raised against hemoglobin S, which initially discriminated poorly between hemoglobins S and A, was fractionated by absorption to a column of Sepharose to which a synthetic peptide corresponding to the first 13 amino-acid residues of the #beta# chain of sickle hemoglobin had been covalently bound. A subpopulation of the antiserum was eluted from this column with 4 M guanidine . HCl. These antibodies showed binding to hemoglobin S but not to hemoglobin A and this interaction could be inhibited by the synthetic peptide. These antibodies, of demonstrated fine structural specificity, may be useful in the detection of sickle hemoglobin and in the study of its structure in solution.
The effect of NaCl and Na_2SO_4 treatments on chlorophyll content, rate of "1"4C assimilation and products of photosynthesis in peanut (Arachish hypogaea L.) variety TMV-10 has been investigated. It was observed that chlorophyll content was affected mainly by NaCl, Na_2SO_4 treatment lowered the rate of photosynthetic "1"4CO_2 fixation. The analysis of labelled products revealed that the salts affect the carbon metabolism differently. The radioactivity was found to be accumulated in fractions of sugars and sugarphosphates in the leaves of NaCl treated plants. Na_2SO_4 treatment brought about considerable decline in labelling of sugars and an increase in labelling of amino acids and sugarphosphates. (orig.).
A new method for determining the year of birth, the year of death, and hence, the age at death, of post-bomb and recently deceased elephants has been developed. The technique is based on Accelerator Mass Spectrometry radiocarbon analyses of small-sized samples extracted from along the length of a ge-line of an elephant tusk. The measured radiocarbon concentrations in the samples from a tusk can be compared to the {sup 14}C atmospheric bomb-pulse curve to derive the growth years of the initial and final samples from the tusk. Initial data from the application of this method to two tusks will be presented. Potentially, the method may play a significant role in wildlife management practices of African national parks. Additionally, the method may contribute to the underpinnings of efforts to define new international trade regulations, which could, in effect, decrease poaching and the killing of very young animals.
Three holes the size of deposition holes (depth 7.5 m and diameter 1.5 m) were bored in the Research Tunnel at Olkiluoto, Finland. A novel full-face boring technique was used based on rotary crushing of rock and removal of crushed rock by vacuum flushing through the drill string. The purpose of the work was to demonstrate the feasibility of the technique. During the boring test procedures were carried out in order to determine the effect of changes in operating parameters on the performance of the boring machine and the quality of the hole. The boring method was found to be technically feasible and efficient. Evaluation of the quality of the hole included studies of the geometry of the hole, measurements of the surface roughness using a laser profilometer and study of excavation disturbances in the zone adjacent to the surface of the holes using two novel methods, He-gas diffusion and the {sup 14}C-polymethylmethacrylate methods. 43 refs.
Iodo(/sup 14/C)antipyrine autoradiography was used to measure gastric mucosal blood flow in anesthetized rats and to study regional distribution. Blood flows of 61 +/- 8 ml.100 g-1.min-1 (means +/- SE) in corpus and 84 +/- 9 ml.100 g-1.min-1 in antral mucosa compared well with previously reported measurements by hydrogen clearance. Blood flow in the crests of corpus mucosal folds was significantly higher than in the valleys between folds, indicating that the greater susceptibility of the former areas to acute injury, documented in several studies, is not associated with a perfusion defect in the resting stomach. Corpus mucosal blood flow was also higher in the side walls of the stomach than in the greater curvature region, and in distal than in proximal locations. No systematic regional variations within antral mucosa were demonstrated.
Soya- and oats-lipoxygenase (E.C. 1.13.1.13) are incubated by "1"4C-marked linoleic acid. The volatile aldehydes arising thereby are isolated. The activity of the components separated by gaschromatography is written down by a printing indicator and the impulses/min are registered and printed out by a ratemeter. Thus the aldehydes which are produced by the enzymatic oxydation with lipoxygenase from the molecule of the linoleic acid can be determined. The composition of the mixture of aldehydes is calculated in mol-% from the measured impulses for peak. A possible origin of pathway is indicated for the main reaction products hexanal (soyalipoxygenase) and non-trans-2-enal (oats-lipoxygenase). (orig.).
The purpose of this study was to examine arachidonic acid (AA) metabolism and to characterize the type of adrenergic receptor (AR) involved in the production of the major metabolite of this fatty acid. ({sup 14}C)AA was incubated with GPT-rings and the radiolabelled products were extracted and separated by TLC method. The medium was also assayed for radiolabelled immunoreactive PG's (iPG's) and leukotrienes (LT) B4 and C4 by RIA or Enzyme immunoassay (EIA) after exposure to various AR agonists. ({sup 14}C)AA was incorporated into GPT-rings and metabolized mainly into iPGE2 and smaller amounts into PGF2{alpha}. Trace amounts of PGD2 and 6-keto-PGF1{alpha} but not LTB4 or LTC4 were detected by RIA and/or EIA. Incubation of GPT rings for 15 minutes with isoproterenol and salbutamol resulted in a significant increase of PGE2 synthesis (optimum conc: 10{sup {minus}7}, 10{sup {minus}7}M ...
The purpose of this study was to examine arachidonic acid (AA) metabolism and to characterize the type of adrenergic receptor (AR) involved in the production of the major metabolite of this fatty acid. ["1"4C]AA was incubated with GPT-rings and the radiolabelled products were extracted and separated by TLC method. The medium was also assayed for radiolabelled immunoreactive PG's (iPG's) and leukotrienes (LT) B4 and C4 by RIA or Enzyme immunoassay (EIA) after exposure to various AR agonists. ["1"4C]AA was incorporated into GPT-rings and metabolized mainly into iPGE2 and smaller amounts into PGF2#alpha#. Trace amounts of PGD2 and 6-keto-PGF1#alpha# but not LTB4 or LTC4 were detected by RIA and/or EIA. Incubation of GPT rings for 15 minutes with isoproterenol and salbutamol resulted in a significant increase of PGE2 synthesis (optimum conc: 10"-"7, 10"-"7M respectively). In contrast, dobutamine, norepinephrine, phenylnephrine and xylazine (up to 10"-"6M) did not significantly increase ...
The metabolic actions of GH can be divided into acute (insulin-like) and chronic (lipolytic/anti-insulin). The insulin-like actions of GH are most readily elicited in GH-deficient animals as GH induces resistance to its own insulin-like action. Like GH, PGF stimulates growth and cross-reacts with anti-hGH antibodies. Independent experiments were conducted comparing the direct actions of PGF to insulin or hGH in vitro. Insulin-like effects were determined by the ability of PGF, insulin or hGH to stimulate (U-/sup 14/C)glucose metabolism in epidydimal fat pads from normal rats and by inhibition of epinephrine-stimulated lipolysis. Direct stimulation of lipolysis was used as anti-insulin activity. To determine if PGF competes for insulin or GH receptors, adipocytes (3 x 10/sup 5/ cells/ml) were incubated with either (/sup 125/I)insulin or (/sup 125/I)hGH +/- PGF, +/- insulin or +/- hGH. PGF stimulated glucose oxidation and /sup ...
The metabolic actions of GH can be divided into acute (insulin-like) and chronic (lipolytic/anti-insulin). The insulin-like actions of GH are most readily elicited in GH-deficient animals as GH induces resistance to its own insulin-like action. Like GH, PGF stimulates growth and cross-reacts with anti-hGH antibodies. Independent experiments were conducted comparing the direct actions of PGF to insulin or hGH in vitro. Insulin-like effects were determined by the ability of PGF, insulin or hGH to stimulate [U-"1"4C]glucose metabolism in epidydimal fat pads from normal rats and by inhibition of epinephrine-stimulated lipolysis. Direct stimulation of lipolysis was used as anti-insulin activity. To determine if PGF competes for insulin or GH receptors, adipocytes (3 x 10"5 cells/ml) were incubated with either ["1"2"5I]insulin or ["1"2"5I]hGH +/- PGF, +/- insulin or +/- hGH. PGF stimulated glucose oxidation and "1"4C-incorporation into lipids. Insulin, hGH and PGF inhibited lipolysis (33%, ...
The disposition of three (1-/sup 14/C)-chlorododecanes (MCDD, PCDD I and PCDD II; 17.4%, 55.9%, and 68.5% chlorination) was studied in C57Bl mice. (1-/sup 14/C)-lauric acid (LA) was studied as reference compound. Fifty-two percent (MCDD), 32% (PCDD I), and 8% (PCDD II) of the radioactive doses were exhaled as /sup 14/CO/sub 2/ during 12 h after i.v. injection. Similar results were obtained after p.o. administration. In addition to a marked labelling of the liver and fat, the distribution patterns observed at 24 h after administration revealed an uptake of radioactivity in tissues with high cell turnover/high metabolic activity, e.g., intestinal mucosa, bone marrow, salivary glands and thymus. The concentration of radioactivity in these sites and the exhalation of /sup 14/CO/sub 2/, which were inverse to the degree of chlorination, indicate that the chloroalkanes are degraded to metabolites which can be ...
Callus cultures derived from pith tissue of Nicotiana tobacum were grown on two media either under continuous illumination or in complete darkness. The first medium limited greening ability of callus grown in the light (3 milligrams per liter naphthalene acetic acid, 0.3 milligram per liter 2-isopentenylaminopurine, Murashige and Skoog salts, and 2% sucrose). The second medium encouraged chlorophyll synthesis (greening) though not shoot formation (0.3 milligram per liter naphthalene acetic acid; 0.3 milligrams per liter 2-isopentylaminopurine). To measure intracellular concentrations, calli were grown for 15 days on these standard media containing (U-/sup 14/C)sucrose. The dry weight proportions of the calli (as a fraction of fresh weight) and many metabolite concentrations nearly doubled in light-grown cells compared to dark-grown cells and increase 30 to 40% on low-auxin media relative to high-auxin media. Glutamine concentrations (from 4 to ...
Cultured 3T3-L1 cells have been used as a model system to investigate the mechanism of fatty acid uptake by adipose tissue. Using a 1:1 molar ratio of /sup 14/C-oleate and defatted bovine serum albumin (BSA), fatty acid (FA) uptake was quantitated at 4/sup 0/ and 37/sup 0/ as cell associated radioactivity. The profile of FA uptake in preadipocytes and adipocytes was biphasic; an initial rapid phase (1-20s) followed by a second slower phase (60-480s). At 37/sup 0/ the initial rate of FA accumulation in preadipocytes was identical to that in adipocytes, whereas the rate of accumulation during the second phase increased 7-fold (100 ..mu..M total FA) as a consequence of adipose conversion. When uptake measurements were made at 4/sup 0/ in adipocytes, the initial rate was identical to that at 37/sup 0/, however the rate of second phase decreased 5-fold. Incubation of /sup 14/C-BSA and nonradiolabeled FA with ...
Regional arterial CO2 tension (PaCO2) reactivity of cerebral blood flow (CBF) and the effect of PaCO2 on the spatial and temporal heterogeneity of CBF were investigated by using autoradiographically determined CBF in the rat middle cerebral artery occlusion model after a 2-h period under pentobarbital anesthesia to clarify the relation between PaCO2 reactivity, CBF heterogeneity, and the temporal cycling of CBF. PaCO2 was adjusted to one of four levels. CBF was determined in four cortical areas and white matter using the tissue fractionation of [14C]iodoantipyrine [( 14C]IAP) in combination with vessel mapping using in vivo 4% thioflavine S. Specific PaCO2 reactivity and CBF were normal in the nonischemic cortex, normal, although slightly depressed, in the border zone far from the ischemic core area, and depressed in the border zone adjacent to the ischemic core area (P less than 0.001) and the ischemic ...
This document presents the findings of an extensive study of the ore mining and dressing industry, for the purpose of developing effluent limitations guidelines for existing point sources and standards for performance new sources, to implement Sections 30...
...2010-10-01 false Ordering from Government supply sources. 51.103 Section 51.103...CONTRACTORS Contractor Use of Government Supply Sources 51.103 Ordering from Government supply sources. (a) Contractors placing...
...false Priorities for use of Government supply sources. 208.002 Section 208...ACQUISITION PLANNING REQUIRED SOURCES OF SUPPLIES AND SERVICES 208.002 Priorities for use of Government supply sources. (a)(1)(v)...
The inhibitory activity of chicken and crocodilian ovomacroglobulins against trypsin was measured before and after their incubation with methylamine. The result for crocodilian ovomacroglobulin showed that methylamine treatment destroyed half of its activity, in unique contrast to human alpha 2-macroglobulin and chicken ovomacroglobulin for which methylamine either destroys the inhibitory activity of the former completely or does not affect that of the latter at all. Free sulfhydryl groups of chicken and crocodilian ovomacroglobulins were titrated with 5,5'-dithiobis(2-nitrobenzoic acid) before and after incubation with trypsin. Prior to the incubation with trypsin the chicken and crocodilian proteins respectively had 0 and 1 titratable sulfhydryl per molecule of Mr 720,000. After treatment with trypsin the crocodilian protein had 3.5-4 titratable sulfhydryls, whereas there were no titratable sulfhydryls in the chicken protein. After denaturation of the crocodilian protein in ...
The transfer kinetics of the negatively charged glycosphingolipid II"3-N-acetylneuraminosyl-gangliotetraosylceramide (GM_1) were investigated by monitoring tritiated GM_1 movement between donor and acceptor vesicles. After appropriate incubation times at 45 "0C, donor and acceptor vesicles were separated by molecular sieve chromatography. Donors were small unilamellar vesicles produced by sonication, whereas acceptors were large unilamellar vesicles produced by either fusion or ethanol injection. Initial GM_1 transfer to acceptors followed first-order kinetics with a half-time of about 40 h assuming that GM_1 is present in equal mole fractions in the exterior and interior surfaces of the donor vesicle bilayer and that no glycolipid flip-flop occurs. GM_1 net transfer was calculated relative to that of ["1"4C]cholesteryl oleate, which served as a nontransferable marker in the donor vesicles. Factors affecting the GM_1 interbilayer transfer rate included phospholipid matrix composition, ...
The authors studied the flow of carbon ({sup 14}C) from CO{sub 2} through sucrose to oligofructans in wheat (Triticum aestivum L.) leaves that had been induced by excision to accumulate fructan. Leaves were either labeled for 30 min and then chased in ambient air for 2 h or labeled continuously for 2 h. Fructans were chromatographed on BioGel P2 column. During continuous labeling, the specific activity was highest in sucrose and decreased for fructans with DP 3 to 5, and each increased linearly with time for 2 h. During the chase period, sucrose specific activity increased for 60 min and then declined while oligofructans gained in specific activity through the 2 h period. After 30 min of labeling, the specific activity of fructose moiety of sucrose was equal to glucose but, in oligofructans, those of the individual fructose units were not. The results may provide insight into the fructosyl donor-acceptor pool relations in wheat leaves.
The two-compartment radioassay for microbial kinetics based on continuous measurement of the {sup 14}CO{sub 2} released by bacterial metabolism of 14C-labeled substrate offers a valuable approach to testing the potency of antimicrobial drugs. By using a previously validated radioassay with gram-positive and gram-negative bacteria, a group of protein synthesis inhibitors was evaluated for their effect on microbial growth kinetics. All tested drugs induced changes in both the slopes and intercepts of the growth curves. An exponential growth model was applied to quantify the drug effect on the processes of bacterial {sup 14}CO{sub 2} liberation and cell generation. The response was measured in terms of a generation rate constant. A linear dependence of the generation rate constant on the dose of spectinomycin was observed with Escherichia coli. Sigmoidal-shaped curves were found in the assays of chloramphenicol and tetracycline. The implications ...
This study focuses on the regulation of sucrose transport across the plasmalemma. Initially, we re-examined the use of leaf discs to study the kinetics of phloem loading using Allium cepa leaves. All tissues exhibited the same linear plus saturable profile as Beta vulgaris, except fructose uptake into the inner parenchyma and bundle-sheath cells; in this case the response was linear. These results indicate that all tissues of the leaf retrieve exogenous sucrose such that kinetics from leaf discs cannot be taken to represent phloem loading per se. We continued our study by investigating the influence of internal sugars on sugar transport across the plasmalemma. We found that if internal sugars were manipulated by heat-girdling techniques or DCMU treatment there was no appreciable change in sucrose influx. However, longer term heat-girdling decreased sucrose uptake. These data indicate that carbohydrate partitioning among the chloroplast, cytosol, and vacuole modulates cytosolic sugar ...
The most abundant minor hemoglobin component of human hemolysate is Hb A1c, which has glucose bound to the N-terminus of the beta chain by a ketoamine linkage. Hb A1c is formed slowly and continuously throughout the 120 day lifespan of the red cell. It can be synthesized in vitro by incubating purified hemoglobin with 14C-glucose. Other minor components, Hb A1a1 and Hb A1a2 are adducts of sugar phosphates at the N-terminus of the beta chain. Hb A1b contains an unidentified nonphosphorylated sugar at the beta N-terminus. In addition, a significant portion of the major hemoglobin component (Hb Ao) is also glycosylated by a glucose ketoamine linkage at other sites on the molecule, including the N-terminus of the alpha chain and the epsilon-amino group of several lysine residues on both the alpha and the beta chains. The results indicate that the interaction of glucose and hemoglobin is rather nonspecific and suggests that other proteins are ...
Obtained experimental data on integral cross sections (ICS) of inelastic scattering of 50.5 MeV #alpha# particles with the excitation of "6","7Li, "9Be, "1"2","1"3C, "1"4C, "1"4N, "2"0Ne, "2"4Mg, "2"8Si nucleus low-lying energy levels are discussed. Regularities, detected in the behaviour of ICS forward scattering for 20-90 deg angles and backscattering for 90-160 deg angles for the target-nucleus under investigation are considered. Effect of reaction open channel number on #alpha#-particle scattering ICS where n,p,d- and #alpha#-channels were considered as the main channels for all the target-nuclei, is discussed. Dependence of #alpha#-particle scattering ICS on the target-nucleus level excitation energy and dependences of reaction open channel number on the channel spin, calculated for 50.5 MeV #alpha# particles and different target nuclei are shown in the diagrams. It is noted that the observed regularities in the #alpha#-particle inelastic scattering ICS are explained by a ...
Glycosaminoglycan synthesis by two subpopulations of a mouse mammary tumor cell line was compared. The two sublines express distinctly different growth characteristics in vitro and in vivo which indicate differences in growth regulation. Newly made glycosaminoglycans were recovered from the culture media, the cell surfaces, and residual cellular material. The cell population which grows more aggressively in vivo (+SA subline, a subline that grows in soft agarose) incorporated about 8 times more (/sup 14/C)glucosamine per cell into total glycosaminoglycans than did the slower-growing population (-SA subline, which does not grow in soft agarose). Appropriate control experiments indicated that the apparent difference in rates of synthesis was not due to discrepancies in glucosamine uptake. The main residual cellular molecule labeled was heparan sulfate, but the predominant molecule at the cell surface and in the culture fluid was hyaluronic acid. ...
The transfer kinetics of the monosiaylated glycosphingolipid, GM_1, between different size phospholipid vesicles was measured using molecular sieve chromatography. At desired time intervals, small unilamellar donor vesicles were separated from large unilamellar acceptor vesicles by elution from a Sephacryl S-500 column ["3H]-GM_1 net transfer was calculated relative to ["1"4C]-cholesteryl oleate, which served as a nontransferable marker in the donor vesicles. The initial GM_1 transfer rate between 1-palmitoyl-2-oleoyl phosphatidylcholine vesicles at 45"0C deviated slightly from first order kinetics and possessed a half time of 3.6 days. This transfer half time is an order of magnitude shorter than that observed from the desiaylated derivative of GM_1. The transfer kinetics are consistent with the authors recent electron microscopic results suggesting a molecular distribution of GM_1 in liquid-crystalline phosphatidylcholine bilayers.
The time of appearance of newly synthesized rRNAs and ribosomal proteins (r-proteins) in the ribosomes of pea cotyledons (Pisum sativum L.) during germination was investigated. The ribosomal fraction was isolated and analyzed according to the method of germination of the embryo in the presence of labeled precursors or after pulse labeling of the embryos at different stages of germination. For the identification of newly synthesized rRNAs in the ribosomes we estimated the relative stability of labeled RNAs to the action of RNase, the sedimentation rate, the ability to be methylated in vivo in the presence of (/sup 14/C)CH/sub 3/-methionine, and the localization in the subunits of dissociated ribosomes. The presence of newly synthesized r-proteins in the ribosomes was judged on the basis of the electrophoretic similarity in SDS-disc electrophoresis of labeled polypeptides of purified ribosome preparations and of genuine r-proteins, as well as ...
Gene analysis was used to determined the presence, abundance and phylogenetic affiliation of methanogens that exist in gas-hydrate-bearing sediment samples obtained from 23 drill cores from the JAPEX/JNOC/GSC et al. Mallik 5L-38 gas hydrate research well. Rates of methane production were examined using sediment-inoculated enrichments containing {sup 14}C-labeled carbon substrates, carbon dioxide and acetate. Archaeal 16S rDNA was only detected in 6 of the samples, resulting in 8 sequences with relationships to the Miscellaneous Crenarchaeotic Group (7 clones) and the Subsurface Euryarchaeotic Group (1 clone). The single Euryarchaeota sequence did not appear to be related to methanogens. Subsamples from the cores showed variable results upon DNA extraction and amplification. Methanogenic Coenzyme M (CoM) was detected in 13 of the 20 cores, but methanogenic methyl CoM reductase genes were not amplified from the samples when using a sensitive ...
Escherichia coli B and K-12 are equally susceptible to the bacteriostatic effects of aerobic paraquat, but they differed strikingly when the lethality of paraquat was evaluated. E. coli B suffered an apparent loss of viability when briefly exposed to paraquat, whereas E. coli K-12 did not. This difference depended on the ability of the B-strain, but not the K-12 strain, to retain internalized paraquat; the B strain was killed on aerobic tryptic soy-yeast extract plates during the incubation which preceded the counting of colonies. This difference in retention of paraquat between strains was demonstrated by delayed loss of viability, by growth inhibition, and by cyanide-resistant respiration after brief exposure to paraquat, washing, and testing in fresh medium. This difference was also shown by using ({sup 14}C)paraquat. This previously unrecognized difference between E. coli B and K-12 has been the cause of apparently contradictory reports and ...
Ependymal cells line the cerebral ventricles forming the interface that separates the cerebrospinal (CSF) and interstitial fluids (ISF). Extracellular molecules move between ependymal cells, whereas lipid soluble molecules pass both between and through cells. We measured the transfer of tritiated water (TOH) from CSF to blood across the ependymal and capillary interfaces by ventriculocisternal (VC) steady-state tissue clearance. Adult cats anesthetized with pentobarbital sodium underwent VC perfusion with the extracellular marker (/sup 14/C)sucrose and TOH added to the artificial CSF. Brain tissue was analyzed for depth of penetration of the isotopes into periventricular gray matter. We found that TOH distribution space was lower than expected from water content measurements, whereas sucrose space was normal. Using VC steady-state equations we calculated an ependymal permeability that was similar to the permeability of the cerebral capillary. ...
Planktivores, zooplankton grazers, and macrobenthos were studied to determine how changes in animal community structure may alter the flow of material in Dunham Pond, CT. Chaoborus and chironomid larvae were studied to determine how they affect the flux of matter across the sediment/water interface. This was done by incubating undisturbed cores in situ and relating changes in water chemistry to larval density. The log-transformed flux rates of iron, manganese, and phosphorus were linearly related to larval biomass. Functional groups may be successfully used to predict rates of material flow. Changes in the mass of macroinvertebrates affect the flux rates of redox-active substances across the sediment/water interface. The use of population densities and feeding characteristics to estimate trophic transfer in Dunham Pond indicate that (1) visual planktivory by larval perch may result in overutilization of prey, (2) ambush planktivory by univoltine Chaoborus appears to under utilize prey, ...
An assay for the microsomal hydroxylation of lauric acid (LA), based on HPLC with flow-through radiochemical detection, has been developed. Conditions were optimized for resolution and quantitation of three microsomal metabolites of "1"4C-LA, one of which has not been reported previously as a metabolite of LA in mammalian microsomal incubations. These products, 12-(omega)-hydroxy-LA, 11-(omega-1)-hydroxy-LA, and a novel metabolite, 10-(omega-2)-hydroxy-LA, were isolated by HPLC and identified by gas chromatography/mass spectrometry. In the presence of NADPH, the formation of all three metabolites was linear with time and microsomal protein concentration. Hydrogen peroxide also supported the microsomal metabolism of LA, although the ratio of metabolites was substantially different than that produced by NADPH-supported microsomes. Several biochemical probes (metyrapone, #alpha#-naphthoflavone, 2-diethylaminoethyl-2,2-diphenylvalerate hydrochloride, and 10-undecynoic acid) were used to ...
Determining the time of most recent fault movement is an important part of assessing a possible site for a nuclear power plant. The purpose of this paper is not to present research information but to provide a practical guide to some of the dating techniques available to the engineering geologist working on nuclear power plant siting. Emphasis is placed on the practical aspects, such as usable minerals, conditions necessary for them to yield correct dates, degree of accuracy, sample collection, sample size, and sample packaging. In this paper, the usual geologic field techniques are taken for granted (such as those used in stratigraphy, paleontology, and structural analysis) for assessing fault history. Laboratory techniques used in conjunction with or supplemental to field methods are discussed. The specific radiometric methods discussed are "1"4C(carbon-14), fission track, K-Ar (potassium-argon), thermoluminescense, Rb-Sr (rubidium-strontium), and U-Th (uranium-thorium). Racemization ...
Characteristics of sugar uptake by immature maize embryos were determined in vitro utilizing a /sup 14/C-sugar solution incubation method. Hexose uptake rates were greater than those for sucrose, however, all showed biphasic kinetics. Glucose and fructose saturable components were evidence at <50 mM and sucrose at <5 mM. Chemical inhibitors (CCCP, DNP, NaCN, and PCMBS) and low temperature reduced sugar uptake. Sucrose influx was pH dependent while glucose was not. Embryos maintained a high sucrose to hexose ratio throughout development. At 25 days after pollination sucrose levels exceeded 200 mM while hexose levels remained below 5 mM. Glucose was rapidly converted to sucrose upon transport into the embryo. These circumstantial data indicate that sugar uptake by immature maize embryos is metabolically dependent and carrier mediated. Furthermore, sucrose transport appears to occur against its concentration gradient involving a H+/sucrose ...
Penicillic acid-negative mutants were obtained from a color mutant derived from Penicillium cyclopium NRRL 1888 through N-methyl-N'-nitro-N-nitrosoguanidine treatment. One mutant (SK2N6) accumulated 6-methyl-1,2,4-benzenetriol, which was not previously known to be a metabolite of P. cyclopium, in addition to orsellinic acid and orcinol. The radioactivity of [1-"1"4C]acetic acid was rapidly incorporated into 6-methyl-1,2,4-benzenetriol in a culture of P. cyclopium SK2N6. Moreover, the radioactivity of ["1"4C]6-methyl-1,2,4-benzenetriol was efficiently incorporated into penicillic acid in a culture of P. cyclopium NRRL 1888. These data indicate that 6-methyl-1,2,4-benzenetriol is a precursor for penicillic acid biosynthesis. The results on the addition of 1,4-dihydroxy-6-methoxy-2-methylbenzene, 6-methoxy-2-methylbenzoquinone (1,4), and 1-O-methylorcinol to a culture of P. cyclopium SK2N6 indicated that only the former two compounds are converted to penicillic acid. Thus, a new portion ...
A comparison between chicken and rat lung was made for microsomal prostaglandin (PG) synthesis from 1-/sup 14/C-arachidonic acid. Microsomal protein (2.0 mg) from chicken or rat lung was incubated in the presence of 20 ..mu..g of 1-/sup 14/C-arachidonic acid (specific activity = 3 x 10/sup 6/ dpm/..mu..mol for chicken; 6 x 10/sup 6/ dpm/..mu..mol for rat), 0.05 M Tris-HCl buffer (pH = 8.0), 0.5 mM epinephrine, and 1 mM reduced glutathione in a total volume of 0.5 ml in a 37/sup 0/C water bath with shaking for 15 min. After acidification with 1 M HCl to pH 3, prostaglandins were extracted with ethyl acetate. The products of the reactions were separated by reversed phase chromatography, and the radioactivity of each prostanoid fraction was determined. The predominant prostanoid synthesized by chicken lung microsomes was PGE/sub 2/, followed by much lower amounts of thromboxane B/sub 2/ (TXB/sub 2/), ...
The advent, in the near future, of compact X-ray sources like Thomson Back-Scattering (TBS) will allow the clinical application of advanced X-ray imaging techniques, such as phase contrast, with higher sensitivity and lower impact in terms of dose delivery. In this work, we theoretically investigated the possibility of using such sources for phase contrast imaging of micro-calcifications included in a breast tissue. In our study we analyzed the phase and amplitude distribution of the TBS source and we showed that this source can be used for phase contrast imaging since the source coherence at the sample position is sufficiently high for achieving good contrast and micrometer spatial resolution. Indeed the spatial coherence of a TBS source is closer to that of a synchrotron radiation source, and much better than that of a laboratory ...
'Small radioactive source results in big accident' have occurred repeatedly in China and worldwide alike. Radioactive source management is one of the key activities for a nuclear power plant to maintain its good safety record and image to the public. From aspects of establishing the management system, centralized storage, periodic accounting, performing whole process control to the source usage and experience feedback etc., the author reports the practice and experience of radioactive source management in Daya Bay Nuclear Power Plant
A spherical-geometry, self-extraction negative ion source has been designed and fabricated. The source utilizes direct surface ionization to form negative ion beams resulting from interactions between high electron affinity gaseous elemental or molecular materials and a negatively biased, spherical-sector LaB{sub 6} surface ionizer maintained at {similar to}1300 K. The design features of this source and principles upon which the source is based are discussed in this report.
The reference medium for brachytherapy dose measurements is water. Accuracy of dose measurements of brachytherapy sources is critically dependent on precise measurement of the source–detector...Full Text Available
A car-borne NaI(Tl) spectrometric system was used together with a {sup 137}Cs source to obtain realistic data in the search for unshielded and semi-shielded orphan sources. The potassium-stripped counts (PSC) method was used to estimate the influence by the shielding on the detection ability. A reduction of about 5% in the critical distance was obtained for the semi-shielded source. A curve fitting method was also developed and evaluated. Results from the curve fitting method showed inferior ability to find the source compared to the PSC method. However, it can be a useful complementary tool, for characterisation of the source shielding, and estimation of the distance from the road.
A car-borne NaI(Tl) spectrometric system was used together with a "1"3"7Cs source to obtain realistic data in the search for unshielded and semi-shielded orphan sources. The potassium-stripped counts (PSC) method was used to estimate the influence by the shielding on the detection ability. A reduction of about 5% in the critical distance was obtained for the semi-shielded source. A curve fitting method was also developed and evaluated. Results from the curve fitting method showed inferior ability to find the source compared to the PSC method. However, it can be a useful complementary tool, for characterisation of the source shielding, and estimation of the distance from the road.
Two sources of negative ions are described. An rf source produces up to 14 ..mu..A beams of He/sup -/ by charge exchange in Rb vapor. The other Source of Negative Ions by Cesium Sputtering (SNICS) produces a wide variety of negative ion beams in the ..mu..A range. Two important features of SNICS are its simple, compact construction and its very good beam emittance (2 to 4..pi..mm mrad MeV/sup 1/2/). Both sources have lifetimes >200 hours and they are used extensively on the Wisconsin EN tandem.
The relative role of the maternal source and the filial sink in controlling the composition of maize (Zea mays L.) kernels is unclear and may be influenced by the genotype and the N...Full Text Available
Polarized electron sources for high energy accelerators took a significant step forward with the introduction of a new laser-driven photocathode source for the SLC in 1992. With an electron beam polarization of >80% and with {approximately}99% uptime during continuous operation, this source is a key factor in the success of the current SLC high-energy physics program. The SLC source performance is used to illustrate both the capabilities and the limitations of solid-state sources. The beam requirements for future colliders are similar to that of the SLC with the addition in most cases of multiple-bunch operation. A design for the next generation accelerator source that can improve the operational characteristics and at least minimize some of the inherent limitations of present sources is presented. Finally, the possibilities for producing ...
Apr 18, 2008 ... The FSS was produced by point-source filtering the individual detector data ... a 1-sigma noise map; and a coverage map giving the count of ...
Sources of industrial emissions of 1,3-butadiene are discussed both by process (production, consumers) and type (equipment leaks, point sources). Quantification of the emissions are presented, as reported...Full Text Available
The present paper describes the development of a radon standard source for use in establishing the traceability of radon concentration measurements in air. Previously, radon generated by bubbling air through a radium salt solution was widely used for calibration of radon measurement equipment; however, the handling of a solid-phase radon source is easier. In the present study, the radioactivity of radon released in a vapor phase was determined from the difference between the radioactivity of the radium and the residual radon progenies in the source. A germanium detector, calibrated using gamma reference sources, was used for these radioactivity measurements. Under equilibrium conditions the radioactivity of the radon released from the radium source was found to be 988 Bq. The source was sealed in a stainless-steel container having a nominal capacity of 6 l to ...
Jan 25, 2006 ... Source positions are determined using matched-filter and centroiding .... The upper 1-sigma statistical error in the full-band counts. ...
One of the aims in the safety assessment of SFR-1 is to estimate the release to the environment. In order to make these calculations there is a need to describe the inventory in greater detail. The new computerised database of waste in SFR-1 gives a good possibility to achieve this. The aim for project SAFE is to make both conservative and realistic radionuclide transport calculations. To achieve this goal there must be two inventories. The conservative inventory is the inventory used in the design of the repository, which in most parts is identical with the limits in the licence for SFR-1. There is a great interest to have good estimates of the volumes of the different waste types. A thorough prognosis should be made in 1999, but until then the latest one from 1995 could be used in the calculations. The total (actual) inventory of nuclides is calculated from the measurements of the easy-to-measure nuclides since, in principle, all hard-to-measure nuclides are calculated by correlation ...
A summary of the topics covered in papers presented at the 1995 Brookhaven joint conference on production, neutralization, and application of negative ion beams is given. The conference topics covered included plasma ion sources, plasma seeding of these sources for increased ion production, beam extraction and transport, computer simulation and design studies, and operation of existing and experimental ion source facilities. Application of the sources to accelerator, tokamak, and thin film deposition are discussed. (AIP) {copyright} {ital 1996 American Institute of Physics.}
The authors report an extension of the source imaging method for analyzing three-dimensional sources from three-dimensional correlations. The technique consists of expanding the correlation data and the underlying source function in spherical harmonics and inverting the resulting system of one-dimensional integral equations. With this strategy, they can image the source function quickly, even with the extremely large data sets common in three-dimensional analyses.
Clear effects of the Act on Power Generation from Renewable Energy Sources (EEWaermeG) on the market cannot be recognized both for the depth geothermal energy and ground source geothermal energy. Due to the concrete design of the law a position that is inferior to others is attained in relation to some other renewable energy sources.
An electron accelerator unit is described for electron beam therapy, comprising: a source of an electron beam; means for finally directing at least a portion of the beam to a therapy site, the directing means being mechanically independent of, and electrically isolated from, the source, and having a target area; and means for aligning the source with the directing means, the aligning means comprising means for projecting at least one beam of light from the source toward the target area.
An electron accelerator unit is described for electron beam therapy, comprising: a source of an electron beam; means for finally directing at least a portion of the beam to a therapy site, the directing means being mechanically independent of, and electrically isolated from, the source, and having a target area; and means for aligning the source with the directing means, the aligning means comprising means for projecting at least one beam of light from the source toward the target area.
This document provides a technical basis for the revision of chemical effluent limitations guidelines for the Steam Electric Power Industry reflecting the Best Available Technology Economically Achievable (BATEA) for existing sources, New Source Performance Standards (NSPS) and Pretreatment Standards. The analysis of pollutants and the technologies applicable to their control has been based on specific waste streams of concern.
Severe depletion of nutrients through removal of the above ground litter caused a cessation of growth of a Eucalyptus exserta forest in tropical China. Since there is no above ground input of C in this forest, microbial biomass (C_m_i_c) and soil organic C (C_o_r_g) are maintained by the below ground input only. By determining the maintenance requirement of the soil microflora, it should be possible to estimate the below ground production of this forest. To check this hypothesis the authors performed an experiment with labelled C. Since large scale production and field application of "1"4C labelled Eucalyptus litter were not feasible, 'naturally labelled' C_4 plant litter (Zea mays) was used. Maize litter has a #delta#"1"3C of -12.7 per mille as compared with a #delta#"1"3C of -30.7 per mille for Eucalyptus leaf litter. The "1"3C abundance is used to determine the amount of maize C in each of the soil layers. Investigations were made of how supplementation of the soil with litter ...
One-year-old seedlings of mulberry, the variety of Shinichinose, were used to fix /sup 14/CO/sub 2/ for 10 minutes under light of 18,000 lux at 28 deg C. Photosynthesis was continued after that in the air not containing /sup 14/CO/sub 2/. The specimens were collected immediately after and 10 and 30 minutes after the /sup 14/CO/sub 2/ fixation, divided into mesophyll, vein and stem bark, frozen in liquid N/sub 2/, and the contents of sucrose, glucose and fructose and their radioactivity were measured. The ratio of the radioactivity incorporated into sucrose to the total radioactivity incorporated into each tissue was very large, and the incorporation into glucose or fructose was very little. The content of sucrose was also larger than that of the other sugars in all the tissues. These findings showed that the photosynthates were translocated mainly in the form of sucrose. The ratio of specific radioactivity (dpm/mg sugar) in the mesophyll to that in the vein was 0.28, 0.58 and 0.42, ...
One such agent is the widely used anesthetic, halothane. To study the toxicity of u.v. decomposed halothane, mice were exposed to anesthetic concentrations (1.3%) of non- and u.v.-irradiated halothane in oxygen for 90 min. Halothane sleeping times increased from 14.3 min to 72.5 min. Microsomal mixed function oxidase activity decreased, as shown by prolonged pentobarbital sleeping times 1 day after exposure to halothane and irradiated halothane (54.6 min and 149.1 min, respectively, as compared to a 34.6-min control). Quantitative and qualitative differences were found in the amount of (/sup 14/C)-pentobarbital metabolites excreted by u.v. irradiated halothane-exposed mice compared to either oxygen or non-irradiated halothane-exposed groups. In addition, serum glutamic-oxalacetic transaminase (SGOT) of irradiated halothane-exposed mice increased to 233% of the control values, and serum glutamic-pyruvic transaminase (SGPT) were 377% of control ...
In this study, we measured the effects of different concentrations of paraquat (0,01 mM and 1,0 mM) on the 1-"1"4CO_2 and 6-"1"4CO_2 production of rabbit lung slices and isolated alveolar macrophages, in 20% and 95% oxygen phases respectively. A 95% oxygen phase induced an increase in the 6-"1"4C-glucose oxidation of control lung slices over a 3-hour period, while the increased activity of the pentose pathway over the first 2 hours started to decline during the third hour of incubation. Paraquat (1,0mM) in 20% oxygen caused a consistent increase in the 6-"1"4CO_2 production by lung slices, but in a 95% oxygen phase gradually inhibited the 6-"1"4C-glucose oxidation over a period of 3 hours. The pentose phosphate pathway was highly significantly stimulated by 1,0 mM paraquat in 20% and 95% oxygen over 3 hours. When isolated alveolar macrophages (viability 95%) were incubated in a 20% and 95% oxygen phase respectively, both the 6-"1"4C-glucose and 1-"1"4C-glucose oxidation rates were ...
The stoichiometry of photorespiration, S, is defined as the fraction of glycolate carbon photorespired. It is postulated that under steady-state conditions there are two determinants of the ratio of photorespiration to net photosynthesis: the partitioning of ribulose bisphosphate between oxidation and carboxylation, and the partitioning of glycolate between reactions leading to complete oxidation to CO/sub 2/ (S . 100%) and those yielding CO/sub 2/ plus serine (S . 25%). S may be calculated using two independent probes of the system. The physical probe, using an infrared gas analyzer, measured photorespiration and net photosynthesis, and hence their ratio PR/NPS . pn(phys). The metabolic probe employed tracer (3R)-D-(3-/sup 3/H1,3-/sup 14/C)glyceric acid to determine r, the fraction of /sup 3/H retained in the triose phosphates leaving the chloroplasts. It is deduced from the postulated model that S . pn(phys) . r/(1 - r). Experiments have been ...
A portion of the active site of rabbit skeletal myosin near the ribose ring of ATP can be labeled by the photoaffinity analogue 3{prime}(2{prime})-O-(4-benzoylbenzoyl)adenosine triphosphate (Bz{sub 2}ATP). The specificity of the photolabeling was assured by first trapping ({sup 14}C)Bz{sub 2}ATP at the active site by use of thiol cross-linking agents. Five radioactive peptides were isolated by high-performance liquid chromatography after extensive trypsin and subtilisin digestion of photolabeled myosin subfragment 1. Four of these peptides were sequenced by Edman techniques, and all originated from a region with the sequence Gly-Glu-Ile-Thr-Val-Pro-Ser-Ile-Asp-Asp-Gln, which corresponds to rabbit myosin heavy chain residues 312-328. The fifth labeled peptide had an amino acid composition appropriate for residues 312-328. Amino acid composition, radiochemical analysis, and sequence data indicate that Ser-324 is the major amino acid residue ...
The photosynthetic response to light of epiphytic algae from Lake Wingra, Wisconsin was determined monthly during the 1978 and 1979 growing seasons.A /sup 14/C technique was developed for measurement of photosynthesis of the intact epiphyte community which was then removed by shaking. The photosynthetic rate at low light, ..cap alpha.., varied from 5.56 to 18.26 ..mu..g C (mg Chl a)/sup -1/ h/sup -1/ (..mu..Em/sup -2/s/sup -1/)/sup -1/ while P/sup B//sub max/, the photosynthetic rate at light saturation, ranged from 1.0 to 2.6 mg C (mg Chl a)/sup -1/ h/sup -1/. During 1979, variations in ..cap alpha.. and P/sup B//sub max/ followed the sun-shade model for photosynthetic adaptation: P/sup B//sub max/ was highest in summer and lowest in spring and fall, while ..cap alpha.. followed the opposite pattern. Patterns in ..cap alpha.. and P/sup B//sub max/ for 1978 were less apparent. During 1979, P/sup B//sub max/ was significantly correlated with ...
We used the tissue distribution of ({sup 14}C)butanol to quantitate regional blood flow in the spinal cord (RSCBF) of pentobarbital-anesthetized, normothermic rats in which segmental local cooling pentobarbital-anesthetized, normothermic rats in which segmental local cooling of the spinal cord (to 25-28{degrees}C) at vertebral levels C4-C6 (n = 6) or T13-L1 (n = 6) was induced. Thirty minutes later, blood flow measurements were made at seven levels of the spinal cord and in the sciatic nerve trunks and biceps femoris muscles. Sham-cooled rats served as controls (n = 12). In control rats, RSCBF varied between 41.5 +/- 2.4 and 65.1 +/- 3.2 ml.min-1.100 g-1. Local cooling of the C4-C6 cord segment reduced RSCBF by 32%, from 65.1 +/- 3.2 to 44.4 +/- 3.5 ml.min-1.100 g-1 (P less than 0.01). Tissue vascular resistance (R) in the cooled C4-C6 segment was elevated versus control. There were no other changes in RSCBF at the other cord levels or in the ...
Administration of [ring-U-14C]propanil (3,4-dichloropropionanilide) to male Sprague-Dawley rats (30, 100, and 300 mg/kg, ip) increased the formation of methemoglobin at the two highest doses. Following a propanil dose of 100 mg/kg, methemoglobin formation attained a maximum level of 5% by 1.5 hr and declined to normal levels (approximately 2.5%) by 12 hr. Hemoglobin binding attained a maximum level of 50 pmol/mg protein by 12 hr, and remained constant for 24 hr. Following a propanil dose of 300 mg/kg, methemoglobin formation attained a maximum level of 24% by 4.5 hr, and declined to a level of 5% by 24 hr. Hemoglobin binding attained a maximum level of 425 pmol/mg protein by 12 hr, and remained constant for 24 hr. Hemoglobin binding was also detected at the lowest propanil dose (10 pmol/mg protein) even though methemoglobin formation was not observed. HPLC analysis of alkaline-treated hemoglobin from propanil-treated rats indicated the presence ...
Nitrogen metabolism and protozoa production rate using "1"4C-choline as marker were studied on 9 adult male crossbred (Tharparker x Brown Swiss) rumen fistulated animals divided into 3 groups (A, B and C). All the animals were fed concentrate mixture and wheatstraw. However, groundnut cake (GNC) in concentrate mixture was untreated in group A, 50 per cent formaldehyde treated in group B and 100 per cent formaldehyde treated in group C. Although, DM intake was similar in these groups but water intake was significantly (P<0.05) higher in control group. Total-N, ammonia-N and blood urea were significantly lower in group B and C as compared to group A. Apparent CP digestibility was not affected by addition of formaldehyde treated GNC at 50 and 100 per cent levels. However, N balances increased significantly (P<0.05) due to addition of protected protein in diet. Protozoal pool as well as production rate were significantly (P<0.01) decreased due to formaldehyde treatment of GNC ...
Microorganisms associated with fractured basalt core were compared to those suspended in groundwater pumped from the same well in the eastern Snake River Plain Aquifer (Idaho, USA). Two wells influenced to different degrees by a mixed-waste plume in the fractured basalt aquifer were examined. In one well, an array of dialysis cells filled with either deionized water or crushed basalt was equilibrated to compare the microorganisms collected in this fashion with those from core and groundwater samples collected in a traditional manner from the same well. Analyses were performed to characterize these samples and to provide a basis for comparison. These included total cell counts by microscopy; total biomass by phospholipid fatty acid analysis; enumerations of viable aerobic heterotrophs, groups of putative aerobic co-metabolic TCE-degraders and aerobic H2-oxidizing bacteria; mineralization of 14C- labeled acetate; and enrichments for dissimilatory ...
The process of carbonate dissolution at the sediment-water interface has two possible end-member boundary conditions. Either the carbonate particles dissolve mostly before they are incorporated into the sediment by bioturbation (interface dissolution), or the vertical mixing is rapid relative to their extermination rate (homogeneous dissolution). In this study, a detailed radiocarbon profile was determined in deep equatorial Pacific sediment that receives a high rate of carbonate supply. In addition, a box model of sediment mixing was used to simulate radiocarbon, carbonate content, and excess thorium profiles that result from either boundary process following a dissolution increase. Results from homogeneous dissolution imply a strong, very recent erosional event, while interface dissolution suggests that moderately increased dissolution began about 10,000 years ago. In order to achieve the observed mixed layer radiocarbon age, increased homogeneous dissolution would concentrate a ...
The influence of sediment dwelling macroinvertebrates on fate and bioavailability of contaminants in freshwater systems was determined using the burrowing mayfly, Hexagenia limbata, as a representative benthic organism. Two series of experiments were conducted: the first to determine the effect of mayflies on movement of contaminants into sediment and organisms, and the second to examine the effect of mayflies on release of contaminants from sediments to the water column and their subsequent accumulation in fish. Concentrations of "1"4C labelled DDT, hexachlorobenzene (HCB), and dihexylphthalate (DHP) in water were 0.11 +/- 0.01, 0.062 +/- 0.005 and 0.006 +/- 0.007 ppb, respectively. Total mass of DHP in the burrow wall was about equal to mass on the surface, indicating that mayflies were capable of doubling the amount of DHP sorbed per unit surface area of sediment. Adsorption of contaminants from water pumped through mayfly burrows increased depth of penetration and mass of DDT, DHP, ...
The effects of purified Helminthosporium maydis T (HmT) toxin on active Ca/sup 2 +/ transport into isolated mitochondria and microsomal vesicles were compared for a susceptible (T) and a resistant (N) strain of corn (Zea mays). ATP, malate, NADH, or succinate could drive /sup 45/Ca/sup 2 +/ transport into mitochondria of corn roots. Ca/sup 2 +/ uptake was dependent on the proton electrochemical gradient generated by the redox substrates or the reversible ATP synthetase, as oligomycin inhibited ATP-driven CA/sup 2 +/ uptake while KCN inhibited transport driven by the redox substrates. Purified native HmT toxin completely inhibited Ca/sup 2 +/ transport into T mitochondria at 5 to 10 nanograms per milliliter while transport into N mitochondria was decreased slightly by 100 nanograms per milliliter toxin. Malate-driven Ca/sup 2 +/ transport in T mitochondria was frequently more inhibited by 5 nanograms per milliliter toxin than succinate or ATP-driven Ca/sup 2 +/ uptake. However, ...
Ten Holstein steers (579 kg average body weight) were fed either alfalfa hay (12.2% crude protein) or a 90% concentrate diet to supply 14.2 or 25.2 Mcal ME respectively for a minimum of 28 days. Samples of rumen epithelial tissue were removed at slaughter from the anterior ventral sac, washed free of feed particles and transported to the laboratory in oxygenated Krebs-Ringer bicarbonate buffer (KRB; pH 7.4). Papillae were weighed (100-200 mg) in triplicate into flasks containing 3 ml KRB with 1 mM glutamine or 5 mM glucose and acetate (50 mM), propionate (25 mM), butyrate (15 mM), lactate (1 mM) and glucose (5 mM) or glutamine (1 mM) as competing substrates. A parallel set of flasks contained 1 or .5 #mu#Ci of [U-"1"4C]-glutamine or glucose respectively for "1"4CO_2 production. There were no interactions with dietary energy intake and substrate addition. Increasing the dietary energy intake increased (P < .01) rates of uptake, "1"4CO_2 production and net lactate production from ...
The NCRP Wound Model, which describes the retention of selected radionuclides at the site of a contaminated wound and their uptake into the transfer compartment, has been combined with the ICRP element-specific systemic models for those radionuclides to derive dose coefficients for intakes via contaminated wounds. These coefficients can be used to generate derived regulatory guidance (i.e., the activity in a wound that would result in an effective dose of 20 or 50 mSv, or in some cases, a organ-equivalent dose of 500 mSv) and clinical decision guidance (i.e., activity levels that would indicate the need for consideration of medical intervention to remove activity from the wound site, administration of decorporation therapy or both). Data are provided for 38 radionuclides commonly encountered in various activities such as nuclear weapons, fuel fabrication or recycling, waste disposal, medicine, research, and nuclear power. These include 3H, 14C, ...
The effect of prenatal cimetidine exposure (PreCM) on the duration of pentobarbital-induced narcosis (DPN) was assessed in immature (14- and 28-day old) and adult (50-60-day old) male and female rats. PreCM exposure was accomplished by treating mothers with cimetidine (CM) (20 mg/kg, ip) daily for the last two days of gestation and then (0.01% in drinking water) throughout lactation. Pregnant mothers of untreated offspring (Con) received saline. PreCM decreased DPN to 505 +/- 33 min (from 611 +/- 23 min in Con) and 393 +/- 190 min (from 686 +/- 44 min in Con) in 14-day old male and female rats, respectively. Similarly, PreCM decreased DPN to 88 +/- 15 min (from 134 +/- 3 min in Con) and 102 +/- 19 min (from 171 +/- 44 min in Con) in 28-day old male and female rats, respectively. At 21 days, PreCM did not alter DPN in either sex. At 50-60 days, however, it decreased DPN to 144 +/- 41 min (from 238 +/- 7 min in Con) in females but had no effect in males; PreCM also increased the plasma ...
Polychlorinated n-alkanes (PCAs) are group of chemicals manufactured by chlorination of liquid n-paraffin or paraffin wax that contain 30 to 70% chlorine by weight. Large amounts of PCAs are widely used as plasticizers for vinyl chloride, lubricants, paints, and flame retardants and number of other industrial applications. Annual global production of PCAs is approximately 300 kilo tones, with a majority having medium-carbon-chain (C14-C19) length. According to the investigation made by Kagaku Kogyo Nippon-Sha, the annual consumption of PCAs in Japan was about 83,000 tons in between 1986-2001. Short-carbon-chain (C10-C13) has been placed on the Priority Substance List under Canadian Environmental Protection Act and on the Environmental Protection Agency Toxic Release Inventory in the USA due to its potential to act as tumor promoters in mammals. Data on environment levels of PCAs is meager, nevertheless, PCAs have been measured at relatively ...
Under certain growth conditions, the human colon adenocarcinoma cell line HT-29 exhibits intestinal enterocyte-like properties. The differentiated cells possess a brush border with the enzyme markers (aminopeptidase and sucrase) normally associated with the intestine. To aid in the characterization of the transport properties of these cells, the uptake of a non-metabolizable amino acid analog, "1"4C-#alpha#-methylaminoisobutyric acid (MeAIB) as examined in the HT-29-Al subclone which possesses a brush border. The cells exhibited a time-dependent uptake of MeAIB which was concentrative and sodium-dependent. The pH optimum for uptake was about 7.8. Uptake was inhibited by low temperature, 1 mM ouabain, or 0.5 mM dinitrophenol. A 1 hr-preincubation of the cells in an isotonic KCl solution resulted in a decreased uptake rate, suggesting that a negative membrane potential is important for MeAIB uptake. The rate of 0.5 mM MeABIB uptake was inhibited by 40 to 90% by 5 mM of certain small ...
Studies investigated whether changes in omega- and (omega-1)-hydroxylation (OH) of lauric acid (LA) occurred in renal microsomes prepared from SHR compared to Wistar-Kyoto (WK) control rats. Systolic blood pressure in age-matched adult SHR and WKR were 189 +/- 3 and 123 +/- 4 mm Hg(anti X +/- SE) respectively (p < 0.001). No significant differences between SHR and WKR were seen in body weight, kidney weight or renal microsomal protein content. Renal microsomes, prepared from whole kidneys, were incubated with 10 mM NADPH and ["1"4C]LA at concentrations between 5-50 #mu#M. The 11- and 12-OH metabolites of LA were separated by HPLC using a reverse phase column with a methanol:water:acetic acid (62:37.8:0.2) mobile phase. Apparent (app) V/sub max/ values for 12-OH in WKR and SHR were 0.87 +/- 0.19 vs 1.48 +/- .11 nmoles/mg protein/min (p < 0.05), respectively, while values for 11-OH were 0.51 +/- 0.12 vs 0.60 +/- .07, respectively. No significant differences were found in app K/sub ...
Materials for the construction of cold neutron sources must satisfy a range of demands. The cryogenic temperature and irradiation create a severe environment. Candidate materials are identified and existing cold sources are briefly surveyed to determine which materials may be used. Aluminum- and magnesium-based alloys are the preferred materials. Existing data for the effects of cryogenic temperature and near-ambient irradiation on the mechanical properties of these alloys are briefly reviewed, and the very limited information on the effects of cryogenic irradiation are outlined. Generating mechanical property data under cold source operating conditions is a daunting prospect. It is clear that the cold source material will be degraded by neutron irradiation, and so the cold source must be designed as a brittle vessel. The continued effective operation of many different cold ...
An analyser for detecting explosives has at least one neutron source and a plurality of gamma ray detectors. An article to be analysed is moved adjacent the source and detectors and is subjected to neutrons which generate gamma rays from any nitrogen in the article. The gamma rays are detected and analysed to determine the nitrogen concentration within the article. In order to achieve an area of uniform detection there are a plurality of detectors equidistant both from the or each source and from the article to be analysed. In order to avoid a decrease in sensitivity away from the source(s) and detectors there may be a second opposing array of source(s) and detectors on the opposite side of the article. For greatest uniformity of detection, a source in one array opposes a detector in the other array and vice versa. Transmission of radiation from the analyser is ...
To respond to an increase of social problems concerning orphan sources in Japan, a working group was formed in the Japan Health Physics Society. In this working group, we investigated how to prevent acute radiation hazard or social panic regarding orphan sources in scrap metal and detection system for orphan sources brought into scrap yards before recycle. For detection system in a scrap yard we conducted an experiment on detectability of monitoring instrument using a radiation source mixed in scrap metal on a truck. The result showed that it was not easy to detect even a high-level source if it was shielded by scrap metal. We also estimated detection limits for radioactive materials in scrap metal by calculation that was validated with experimental data. We summarized present status about orphan sources in Japan and proposed a categorization of orphan ...
The PAH (polycyclic aromatic hydrocarbons) concentration in coastal zones in the Arctic were studied. Assessment in remote areas is difficult because PAHs contamination from fossil fuel discharges and combustion can be masked by PAHs from natural sources, such as oil seeps, bitumens and forest fires. It is believed that the most important source of anthropogenic PAHs in the Arctic is the long range transport of combustion emissions. A comparison study of PAH distribution between the Beaufort Sea and the Barents Sea led to the interpretation of PAH distributions in terms of potential sources and their geochemistry. PAH concentrations in the Barents Sea sediments were found to be 2 to 20 times lower than in the Beaufort Sea sediments; they are believed to be from anthropogenic sources. In the Beaufort Sea the sediments were found to have been derived from natural sources. 7 refs., 2 ...
The Plasma and Ion Source Technology Group at the Lawrence Berkeley National Laboratory have been developing rf-driven ion sources for the last two decades. These sources are being used to generate both positive and negative ion beams. Some of these sources are operating in particle accelerators such as the Spallation Neutron Source (SNS) at Oak Ridge, while others are being employed in various industrial ion beam systems. There are four areas where the rf-driven ion sources are commonly used in industry. (1) In semiconductor manufacturing, rf-driven sources have found important applications in plasma etching, ion beam implantation, and ion beam lithography. (2) In material analysis and surface modification, miniature rf-ion sources can be found in focused ion beam systems. They can provide ion beams of essentially any ...
Analysis of the use of information sources by family physicians is important for both practical and theoretical reasons. First, analysis of the ways in which family physicians handle information may...Full Text Available
Behavioral detection of a low-frequency (40 Hz) vibratory dipole at source distances of 1.5–24 cm was measured by classically conditioned respiratory suppression in goldfish (Carassius...Full Text Available
Cultural monitoring was used to study the incidence and sources of salmonellae in a 4160 bird broiler flock during the growing period, transport and processing in a commercial plant. No salmonellae...Full Text Available
Taking the development of large current, negative ion sources which is in progress aiming at nuclear fusion reactors and the development of high luminance ion sources planned as a part of the Omega Project as the examples, the technology for generating high power ion beams is explained. Both these projects are positioned at the limit of the present technology of high power ion beam application as their targeted beam power reaches several tens MW. Consequently, the requirement for the ion sources is severe, and in particular, the generation of the ion beams having large current density with good convergence is beyond all precedents. The application of high power ion sources has been realized as the neutral beam injectors for large tokamaks. Also the hydrogen negative ion source of large current and the electrostatic acceleration technology for negative ion beams have been developed. ...
A new miniature high-frequency (HF) plasma source intended for bio-medical applications is studied using nitrogen/oxygen mixture at atmospheric pressure. This plasma source can be used as an element of a plasma source array for applications in dermatology and surgery. Nitric oxide and ozone which are produced in this plasma source are well-known agents for proliferation of the cells, inhalation therapy for newborn infants, disinfection of wounds and blood ozonation. Using optical emission spectroscopy, microphotography and numerical simulation, the gas temperature in the active plasma region and plasma parameters (electron density and electron distribution function) are determined for varied nitrogen/oxygen flows. The influence of the gas flows on the plasma conditions is studied. Ozone and nitric oxide concentrations in the effluent of the plasma source are measured using ...
The Holifield Radioactive Ion Beam Facility (HRIBF) now under construction at the Oak Ridge National Laboratory will use the 25-MV tandem accelerator for the acceleration of radioactive ion beams to energies appropriate for research in nuclear physics; negative ion beams are, therefore, required for injection into the tandem accelerator. Because charge exchange is an efficient means for converting initially positive ion beams to negative ion beams, both positive and negative ion sources are viable options for use at the facility; the choice of the type of ion source will depend on the overall efficiency for generating the radioactive species of interest. A high-temperature version of the CERN-ISOLDE positive ion source has been selected and a modified version of the source designed and fabricated for initial use at the HRIBF because of its low emittance, relatively high ionization efficiencies and ...
The Holifield Radioactive Ion Beam Facility (HRIBF) now under construction at the Oak Ridge National Laboratory will use the 25-MV tandem accelerator for the acceleration of radioactive ion beams to energies appropriate for research in nuclear physics; negative ion beams are, therefore, required for injection into the tandem accelerator. Because charge exchange is an efficient means for converting initially positive ion beams to negative ion beams, both positive and negative ion sources are viable options for use at the facility; the choice of the type of ion source will depend on the overall efficiency for generating the radioactive species of interest. A high-temperature version of the CERN-ISOLDE positive ion source has been selected and a modified version of the source designed and fabricated for initial use at the HRIBF because of its low emittance, relatively high ionization efficiencies and ...
Convolutive mixtures of signals, which are common in acoustic environments, can be difficult to separate into their component sources. Here we present a uniform probabilistic framework to separate...Full Text Available
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...
The electrode structure of an inverted cesium sputtering negative ion source has been modified to produce a convergent Cs/sup +/ beam. The intensities of negative ion beams produced with this electrode structure are approximately an order of magnitude greater than previously obtained.
Recent organic geochemical studies differ radically in their interpretation of the origin of the Gulf coast oils. However all studies since (and including) Thompson, et al. 1989, emphasize the considerable geographic variation in genetic oil types and are in generalized agreement as to the genetic oil types present and their spatial and stratigraphic relationships. In particular it is accepted that the Gulf rim (both north and south) is encircled by a ring of Mesozoic carbonate-sourced oils and that there is also at least one major deep water trend of carbonate-sourced oils in the northern Gulf. It is also generally agreed that many of the Gulf rim oils are of Oxfordian-Kimmeridgian age, though some, like the Sunniland oils of Florida, are of lower Cretaceous origin. Major disagreement still occurs over the sources of the Louisiana offshore oils and onshore Wilcox reservoired oils. One {open_quotes}school of ...
Using the Sloan Digital Sky Survey (SDSS) and the FIRST (Faint Images of the Radio Sky at Twenty Centimeters) catalogs, we examined the optical environments around double-lobed radio sources. Previous studies have shown that multi-component radio sources exhibiting some degree of bending between components are likely to be found in galaxy clusters. Often this radio emission is associated with a cD-type galaxy at the center of a cluster. We cross-correlated the SDSS with the FIRST catalog and measured the richness of the cluster environments surrounding both bent and straight multi-component sources. This led to the discovery and classification of a large number of galaxy clusters out to a redshift of z ~ 0.5. We divided our sample into smaller subgroups based on their optical and radio properties. We find that FR I radio sources are more likely to be found in galaxy clusters than FR II ...
Cultural monitoring was used to determine the incidence and sources of salmonellae in a 4160-bird broiler flock raised on litter in 32 pens. Twenty-five of the pens remained apparently free of salmonellae...Full Text Available
The author demonstrates through a specific example that it is possible to extract rotational energy from a Kerr source (in principle, of arbitrary size but not turned black) through a reversible process by suitably injecting tachyons. (Auth.).
BackgroundBlood spots collected onto filter paper are an established and convenient source of antibodies for serological diagnosis and epidemiological surveys. Although recommendations...Full Text Available
This section presents background information supporting the development of effluent limitations guidelines and standards for the concentrated aquatic animal production (CAAP) point source category. Section 1.1 presents the legal authority to regulate the ...
The polarization of extracted SATURNE II proton beam as a function of different ion source configurations was studied. Two distinct experiments were necessary for this purpose. In the first one, the left-right instrumental asymmetry of the beam polarimeter was determined using an unpolarized beam. In the second one this correction factor was applied to asymmetries measured with the beam from the polarized ion source in all polarization states. The measurements were carried out at the proton beam kinetic energy 0.80 GeV, where the pp-elastic scattering analyzing power is near its maximum. The results confirmed that the two so-called ``unpolarized states`` of the source were polarized to several percent, whereas the absolute values of the beam polarizations in the so-called ``polarized states`` were equal and opposite. It was observed that the hexapole lens of the ion source produced beam polarization in ...
This table contains point-source catalogs for the ~2 Ms exposure of the Chandra Deep ... Source positions are determined using centroid and matched-filter techniques; .... The 1-sigma upper statistical error (Gehrels 1986, ApJ, 303, ...
We have investigated the usefulness of ribotyping for the differentiation of aeromonads isolated from five patients with gastroenteritis and from the source water, treatment plant, and distribution...Full Text Available
...identity of a confidential source and, in the case of...lawful national security intelligence investigation, confidential...only by the confidential source, (v) Disclose investigative...exercise its authority to open to public observation...requires that the meeting be...
The possibility of providing high accuracy of absorption and albedo methods of radiometric testing due to the use of high-energy radiation component that has passed through a barrier and gone from it in the opposite direction as a reference source, is considered. It is shown that the use of high-energy component of penetrating radiation as a reference source decreases the device response to the main interference in a much larger degree than its response to the change of measured parameter. Experiments are performed using steel pipes and plates. "2"4"1Am, "1"3"7Cs and "6"0Co are used as sources.
... If the terminal classes were to be information sources ... current credibility of inputs by classes of terminals; the most ... the stochastic queue lengths. ...
Subcritical source-driven noise measurements are simultaneous Rossia and randomly pulsed neutron measurements that provide measured quantities that can be related to the subcritical neutron multiplication factor. In fact, subcritical source-driven noise measurements should be performed in lieu of Rossia measurements because of the additional information that is obtained from noise measurements such as the spectral ratio and the coherence functions. The basic understanding of source-driven noise analysis measurements can be developed from a point reactor kinetics model to demonstrate how the measured quantities relate to the subcritical neutron multiplication factor.
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This paper describes the performance of AlGaN/GaN HEMTs with 2.4 #mu#m source-drain spacing. So far these are the smallest source-drain spacing AlGaN/GaN HEMTs which have been implemented with a domestic wafer and domestic process. This paper also compares their performance with that of 4 #mu#m source-drain spacing devices. The former exhibit higher drain current, higher gain, and higher efficiency. It is especially significant that the maximum frequency of oscillation noticeably increased. (semiconductor integrated circuits)
Negative ion based neutral beam injector is one of the most attractive heating system in future fusion reactors. In realizing the system, the crucial device which has to be developed is a high intensity negative ion source. Significant progress has been made on the negative ion source in these years. Among them, a few ampere negative ion beam were produced stably, while the divergence of negative ion beams becomes to be as low as < 10 mrad. We consider these results are demonstrating the potential of the negative ion source for the heating device in future reactors.
Source-term codes to predict the release of radionuclides from nuclear waste packages have been developed and implemented worldwide. A survey and initial comparison of the attributes and capabilities of 13 international source-term codes was recently completed. This preliminary analysis focused on comparison of transport factors/processes and solution methods. This initial comparison is a necessary first step in a properly-conceived, systematic benchmarking of source-term codes. Advantages of such a comparison include assurance of the mathematical correctness of implemented models, comparison and quantification of variances introduced by different types of simplifications, and identification and quantification of the impact of near-field processes.
The addition of a thermionic rf gun [1] and a photocathode rf gun will allow the Advanced Photon Source (APS) linear accelerator (linac) [2] [3] to become a free-electron laser (FEL) driver [4]. As the FEL project progresses, the existing high-charge DC thermionic gun will no longer be critical to APS operation and could be used to generate high-energy or low-energy electrons to drive a slow-positron source. We investigated possibilities to create a useful low-energy source that could operate semi-independently and would have a low neutron background.
The regional concentrations of nine radiochemicals were measured in rat brain after induction of cerebral ischemia to identify tracers concentrated by brain undergoing selective neuronal necrosis. Transient (30 minute) forebrain ischemia was produced in the rat; 24 hours after cerebral recirculation the radiochemicals were injected intravenously and allowed to circulate for 5 hours. The brain concentrations of the radiochemicals in dissected regions were determined by scintillation counting. Forebrain ischemia of this nature will produce extensive injury to striatal neurons but will spare the great majority of neocortical neurons at 24 hours. The regional concentrations of these radiochemicals varied considerably in both control and ischemic animals. In postischemic animals, 4 radionuclides (/sup 63/Ni, /sup 99/TcO/sub 4/, /sup 22/Na, and (/sup 3/H)tetracycline) were concentrated in the irreversibly damaged striatum in amounts ranging from 1.4 to 2.4 times greater than in normal ...
Full text: Many studies have demonstrated significant declines in 24-hour energy expenditure (TEE) measured by whole body calorimetry with either the process of weight loss or the maintenance of reduced body weight. The aims of this study were to determine the effect of weight loss and two weeks of weight maintenance on TEE using ["1"4C]-bicarbonate-urea, Eleven subjects (6 males, 5 females), mean (#+-#SE) age 50 #+-# 3 years, BMI 34.1 #+-# 2.1 kg/m2 and body fat 38.7 #+-# 3% were studied before and after a decrease in body weight of > 8% over a period of 8 weeks, followed by two weeks of weight maintenance. Weight loss was induced using the combination of Modifast and one small meal a day (#approx#3.34 MJ/day). Body composition (DEXA), resting energy expenditure (REE) and the thermic effect of a 2.7 MJ test meal (TEF) were measured in addition to TEE at week 2 and again at week 12. Diet was assessed using diaries and physical activity energy expenditure (PAEE) was calculated from ...
Southeastern Finland belongs to the area covered by the Weichselian ice sheet, where the release of the ice load caused a rapid isostatic rebound during the postglacial time. While the mean overall apparent uplift is of the order of 2 mm/yr today, in the early Holocene time it was several times higher. A marked decrease in the rebound rate occurred around 8500 BP, however, since then the uplift rate has remained high until today, with a slightly decreasing trend towards the present time. According to current understanding there have neither been temporary increases nor decreases in the rate of uplift during the postglacial time. Even so, it is not known for sure whether there are regional irregularities on the rebound in Finland. Concurrently with land uplift, relative sea-level changes in the Baltic basin were also strongly affected by the global eustatic rise of sea-level. During the early Litorina Sea stage on the southern coast of Finland around 7000 BP, the rise in sea-level ...
Understanding the link between the Sun and climate is vital in the current incidence of global climate change, and 10Be in natural archives constitutes an excellent tracer for this purpose. As cosmic rays enter the atmosphere, cosmogenic isotopes like 10Be and 14C are formed. Variations in solar activity modulate the amount of incoming cosmic rays, and thereby cosmogenic isotope production. Atmospherically produced 10Be enters natural archives such as sediments and glaciers by wet and dry deposition within about a year of production. 10Be from natural archives therefore provides information on past solar activity, and because these archives also contain climate information, solar activity and climate can be linked. One remaining question is to what degree 10Be in natural archives reflects production, and to what extent the local and regional environment overprints the production signal. To explore this, 10Be was measured at annual resolution ...
There are 13 Electron Beam Ion Sources in operation which produce highly charged ions, up to Th[sup 80+] and Xe[sup 53+]. Most of the sources are used to study these ions under electron impact or when recombining with gaseous or solid targets. That provides an insight into the atomic physics of these highly charged ions and into the physics of the plasma in which such ions can be found. This paper reviews the present knowledge of atomic processes, important in the production of such ions with an EBIS.
There are 13 Electron Beam Ion Sources in operation which produce highly charged ions, up to Th{sup 80+} and Xe{sup 53+}. Most of the sources are used to study these ions under electron impact or when recombining with gaseous or solid targets. That provides an insight into the atomic physics of these highly charged ions and into the physics of the plasma in which such ions can be found. This paper reviews the present knowledge of atomic processes, important in the production of such ions with an EBIS.
The current status and future plans of the Ok Ridge Spallation Neutron Source (ORSNS) are reviewed. The ORSNS is a new project initiated by the U.S. Department of Energy (DOE) beginning October 1, 1995, to prepare the conceptual for a new spallation neutron source. (author) 2 refs.
Operation at ITER specifications of the Kamaboko III ion source for 1000 second pulses of deuterium negative ion beams is underway on the MANTIS test stand. Efficient production of negative ions at low arc power requires injection of cesium into the source, temperature control of the plasma grid, and a period of conditioning of several days. Two different concepts of temperature regulated plasma grids are currently being tested. (author)
Results are described of the study of the analytical applicability of a highly efficient ion source developed for a mass spectrometer. Its ionizer is in the form of a partially closed cavity with a small aperture for leading out ions, heated to a high temperature. The new ion source increases the sensitivity of the apparatus in operations with transuranium elements by almost two orders of magnitude. It is possible to perform isotopic analyses with a high salt content in the sample, and to study the characteristics of nuclear fuel, even without chemical separation of the sample elements.
This study intends to develop an efficient market design for the German electricity market, with particular regard to renewable energy sources. The German electricity market is disintegrated, i.e. market sectors are not coordinated by a central agency but by their own interactions. The first part of the investigation analyzes the interdependences of market sectors, while the second part will analyze funding instruments for renewable energy sources on this basis. (orig.)
In conveyor type irradiators, the movement of conveyor and the product boxes is not there until the source is fully in the irradiation position. In case the conveyor system fails the source must automatically be returned to its shielded storage vault. The dose received by the product during the movement of the source from or to the shield becomes significant if the total dose to be received by the product is small. A study has been carried out for evaluating the transient dose received by onions in the POTON irradiator. The results of the study are discussed in this paper. (author)
A study was made of the timber products processing point source category, for the purpose of developing information to assist the EPA in establishing effluent limitations guidelines and standards to implement sections 301, 304, 306, and 307 of the Federal Water Pollution Control Act Amendments of 1972. The document is the result of that study.
This document presents the findings of a study of the Ink Manufacturing Industry for the purpose of developing effluent limitations and standards, and pretreatment standards for existing and new sources to implement Sections 301, 304, 306, 307 and 501 of ...
A method of calculating the neutron source strength in irradiated Fast Flux Test Facility (FFTF), fuel has been developed and is presented in this paper. This method has been used to perform calculations in support of the reactivity monitoring of the FFTF reactor by the modified source multiplication method during refueling operations. 31 refs.
A new, magnetically insulated negative ion source has recently been discovered which can produce pulsed negative ion beams (H/sup -/, Li/sup -/, and C/sup -/) with intensities of 100-300 A/cm/sup 2/ at 1-4 MeV. This source may provide the basis for a high energy neutral beam system for heating large tokamaks.
Abstract The Planck-ATCA Coeval Observations (PACO) project collected data between 4.5 and 40 GHz for 482 sources selected within the Australia Telescope 20 GHz (AT20G) catalogue and observed with the Australia Telescope Compact Array. Observations were done almost simultaneously with the-Planck-satellite, in the period between 2009 July and 2010 August. In this paper, we present and discuss the data for the complete sample of 159 sources with-SAT20G > 200-mJy in the South Ecliptic Pole region. The Planck Early Release Compact Source Catalogue (ERCSC) contains 57 of our sources. A comparison between the PACO catalogue and the ERCSC confirms that the reliability of the latter is better than 95-per cent. The missing ERCSC sources are typically associated with the Large Magellanic Cloud, the ...
We observed at 22 GHz with the VLBI array VERA a sample of 1536 sources with correlated flux densities brighter than 200 mJy at 8 GHz. One half of target sources has been detected. The detection limit was around 200 mJy. We derived the correlated flux densities of 877 detected sources in three ranges of projected baseline lengths. The objective of these observations was to determine the suitability of given sources as phase calibrators for dual-beam and phase-referencing observations at high frequencies. Preliminary results indicate that the number of compact extragalactic sources at 22 GHz brighter than a given correlated flux density level is twice less than at 8 GHz.
The desire to study negative ion structure and negative ion-photon interactions has spurred the development of ion sources for use in research and industry. The many different types of negative ion sources available today differ in their characteristics and abilities to produce anions of various species. Thus the importance of choosing the correct type of negative ion source for a particular research or industrial application is clear. In this study, the results of an investigation on the production of beams composed of negatively-charged rare-earth ions from a cylindrical-cathode-geometry, cesium-sputter-type negative ion source are presented. Beams of atomic anions have been observed for most of the first-row rare-earth elements, with typical currents ranging from hundreds of picoamps to several nanoamps.
Despite the widely recognized usefulness of the AAPM TG-43 brachytherapy dose calculation formalism, a straightforward application of this approach to describe the dose distribution about intravascular line sources as proposed by TG-60 may be difficult or even impossible, especially when these line sources emit low-energy photons or beta particles. The causes of these limitations are investigated and illustrated by means of some numerical examples. In order to solve the observed limitations an adapted formalism is proposed, intended specifically for the description of the dose rate distribution about line sources but conceptually similar to the TG-43/TG-60 formalism. Several examples are presented to illustrate the usefulness of the proposed line source dose calculation formalism.
The Alpine Foreland Basin is a minor oil and moderate gas province in central Europe. In the Austrian part of the Alpine Foreland Basin, oil and minor thermal gas are thought to be predominantly sourced from Lower Oligocene horizons (Schoneck and Eggerding formations). The source rocks are immature where the oil fields are located and enter the oil window at ca. 4 km depth beneath the Alpine nappes indicating long-distance lateral migration. Most important reservoirs are Upper Cretaceous and Eocene basal sandstones.Stable carbon isotope and biomarker ratios of oils from different reservoirs indicate compositional trends in W-E direction which reflect differences in source, depositional environment (facies), and maturity of potential source rocks. Thermal maturity parameters from oils of di...
Consider the set of source distributions within a fixed maximum relative entropy with respect to a given nominal distribution. Lossless source coding over this relative entropy ball can be approached in more than one way. A problem previously considered is finding a minimax average length source code. The minimizing players are the codeword lengths --- real numbers for arithmetic codes, integers for prefix codes --- while the maximizing players are the uncertain source distributions. Another traditional minimizing objective is the first one considered here, maximum (average) redundancy. This problem reduces to an extension of an exponential Huffman objective treated in the literature but heretofore without direct practical application. In addition to these, this paper examines the related problem of maximal minimax pointwise redundancy and the problem considered by Gawrychowski and Gagie, which, for a ...
Both travelers were members of a nine-person US delegation that participated in an international workshop on accelerator-based 14 MeV neutron sources for fusion materials research hosted by the University of Tokyo. Presentations made at the workshop reviewed the technology developed by the FMIT Project, advances in accelerator technology, and proposed concepts for neutron sources. One traveler then participated in the initial meeting of the IEA Working Group on High Energy, High Flux Neutron Sources in which efforts were begun to evaluate and compare proposed neutron sources; the Fourth FFTF/MOTA Experimenters' Workshop which covered planning and coordination of the US-Japan collaboration using the FFTF reactor to irradiate fusion reactor materials; and held discussions with several JAERI personnel on the US-Japan collaboration on fusion reactor materials.
The Holifield Radioactive Ion Beam Facility now under construction at the Oak Ridge National Laboratory will use the 25 MV tandem accelerator for the acceleration of radioactive ion beams to energies appropriate for research in nuclear physics; negative ion beams are, therefore, required for injection into the tandem accelerator. Because charge exchange is an efficient means for converting initially positive ion beams to negative ion beams, both positive and negative ion sources are viable options for use at the facility. The choice of the type of ion source will depend on the overall efficiency for generating the radioactive species of interest. Although direct-extraction negative ion sources are clearly desirable, the ion formation efficiencies are often too low for practical consideration; for this situation, positive ion sources, in combination with charge exchange, are the logical choice. The ...
Soon there will be only 14 states in two compacts that are able to dispose of Low Level Waste (LLW): the Northwest and Rocky Mountain compact with disposal options in Richland, Washington, and the Atlantic compact with disposal options in Barnwell, South Carolina. How do states not in one of the two compacts dispose of their LLW? The Off-Site Source Recovery Project can take possession and dispose of some of the unwanted transuranic sources at the Waste Isolation Pilot Plant (WIPP). However, there will be no path forward for states outside of the two compacts for disposal of their non-transuranic LLW. A solution that has been much discussed, debated and researched, but has not been put into wide scale practice, is the borehole disposal concept. It is the author's position that companies that drill and explore for oil have been disposing of sources in borehole-like structures for years. It should be noted that these ...
XMM-Newton EPIC observations reveal the population of X-ray sources of the bright Local Group spiral galaxy M 31, a low-star-formation-rate galaxy like the Milky Way, down to a 0.2-4.5 keV luminosity of 4.4E34 erg/s. With the help of X-ray hardness ratios and optical and radio information different source classes can be distinguished. The survey detected 856 sources in an area of 1.24 square degrees. Sources within M 31 are 44 supernova remnants (SNR) and candidates, 18 super-soft sources (SSS), 16 X-ray binaries (XRBs) and candidates, as well as 37 globular cluster sources (GlC) and candidates, i.e. most likely low mass XRBs within the GlC. 567 hard sources may either be XRBs or Crab-like SNRs in M 31 or background AGN. 22 sources are new SNR candidates in M 31 based on X-ray selection criteria. Time variability ...
The 3-D model program was developed to apply a mise-a-la-masse method to linear current sources with optional shapes. Mise-a-la-masse method is a bipolar mapping survey method using current sources installed in wells, and recently has been widely used for direct exploration of geothermal reservoirs. This method is also used for monitoring underground fluid as electrode arrangement of fluid flow tomography for surveying underground fluid (geothermal fluid, underground water, petroleum). In the geothermal reservoir exploration, the casing pipes of wells are used as linear current sources, and measured data are processed as those based on vertical current source. In the largely inclined well, the inclination of current sources should be considered. The 3-D modeling program was developed by difference calculus using the theoretical potential equation and apparent resistivity based on ...
Electron cyclotron resonance (ECR) ion sources possess several advantages over ion sources conventionally used for injectors of electrostatic accelerators: improved reliability, high efficiency, simplicity, and the capability of generating bright, high-current ion beams. We have adapted a high-current ECR source originally developed as an injector for a CW RFQ proton linac to serve as a source of intense negative-ion beams for the Tandem Accelerator Superconducting Cyclotron (TASCC) facility at Chalk River. The range of ion species of the source has been extended from H{sup 1+} alone up to Bi{sup 1+}, with both gaseous and nonvolatile feeds. Two intense negative-ion beams of He{sup -} and O{sup -} have been generated so far with the source coupled to a standard charge-exchange canal. We foresee no major problems generating a broad range of negative ions with ...
Electron cyclotron resonance (ECR) ion sources possess several advantages over ion sources conventionally used for injectors of electrostatic accelerators: improved reliability, high efficiency, simplicity, and the capability of generating bright, high-current ion beams. We have adapted a high-current ECR source originally developed as an injector for a CW RFQ proton linac to serve as a source of intense negative-ion beams for the Tandem Accelerator Superconducting Cyclotron (TASCC) facility at Chalk River. The range of ion species of the source has been extended from H1+ alone up to Bi1+, with both gaseous and nonvolatile feeds. Two intense negative-ion beams of He- and O- have been generated so far with the source coupled to a standard charge-exchange canal. We foresee no major problems generating a broad range of negative ions with this system. (author)
Because the number of neutrons and gamma rays and the energy spectrum of particles from spontaneous fission are well characterized for {sup 252}Cf, it can be used as a timed source of fission neutrons and gamma rays. The first such usage incorporated a {sup 252}Cf source into gas scintillators. This paper describes a timed source of neutrons and gamma rays made by depositing {sup 252}Cf on one electrode of a parallel plate ionization chamber that can then be used for determining detection-system characteristics. The emission time of neutrons from spontaneous fission has also been determined by recording the emission time of prompt gamma rays from a {sup 252}Cf source (not incorporated into a detector) adjacent to the surface of a solid or liquid scintillator. This well characterized source of neutrons can thus be used as a randomly pulsed source for a variety of ...
The flux of cosmic ray antiprotons with kinetic energies between /approximately/1 and 15 GeV is /approximately/5 times greater than the flux predicted on the basis of the leaky-box model. This excess is attributed to secondary antineutron production in compact sources. Because the antineutrons are not confined by the magnetic field of the compact source, they leave the interaction site, decay in interstellar space and account for the apparent excess cosmic ray antiproton flux. The escape and decay of neutrons produced in association with the antineutrons is a source of cosmic ray protons. Observations of the angular variation of the intensity and spectral shape of 100 MeV ..gamma..-rays produced by neutron-decay protons in the reaction p + p ..-->.. ..pi../sup 0/ ..-->.. 2..gamma.. could reveal compact-source cosmic ray production sites. COS-B observations of spectral hardening near point ...
A statistical method is developed to determine the locations of major pollutant sources affecting a distant downwind receptor, provided that air trajectories can be estimated. Probability density functions are estimated which indicate the overall residence time of air parcels over a given geographic region as they travel toward a receptor and residence time for the case of high pollutant concentrations at the receptor. These functions are used to estimate a conditional probability function which indicates the potential for a source region to contribute to high air pollution concentrations. Finally, a source contribution function is formulated to indicate the relative contribution of different source regions to high concentrations at the receptor. The method is tested using data collected at Grand Canyon National Park in 1980. The dominant pathway for air masses arriving at Grand Canyon during this ...
A versatile, high brightness, volume type, low power RF source, capable of producing positive ion beams with intensities as high as 1 mA from gaseous feed materials and microamperes of negative ion beams has been characterized. The source can also be operated as a plasma sputter negative ion source to generate up to 1 mA of a selected species. The performance of the source in the positive and negative volume modes of operation can be greatly enhanced by addition of a removable, water cooled filament assembly in place of the negative sputter probe. For examine, the material utilization efficiencies of gaseous feed species can be more than doubled, total current intensities increased up to 40%, molecular dissociation fractions increased by 20% and minimum operating pressures reduced by a factor of four when operated in the volume mode. These added electrons also favorably effect, as a consequence of lower ...
The power source facilities of JT-60 consist of poloidal magnetic coil power source, toroidal magnetic coil power source, the power generation facility for heating, operation power distribution facility and secondary cooling facility, and at the time of the experiment operation of JT-60, they supply 1300 MVA of instantaneous maximum power to loads. The component machinery and equipment of the power source facilities are installed in about 20 indoor and outdoor places, and their mounted parts are about 15,000 kinds. About 3,000 kinds of spare parts are preserved in 15 exclusively used stores. The managing system for mounted parts and spare parts of JT-60 power source facilities which possesses the functions of rapidly and efficiently carrying out the storage of large quantity of information, mutual relating and retrieval by making mounted parts and spare parts into a data base and ...
Recent analyses of the anisotropy of cosmic rays at 10{sup 18} eV (the AGASA and SUGAR data) show significant excesses from regions close to the galactic centre and Cygnus. Our aim is to check whether such anisotropies can be caused by single sources of charged particles. We investigate propagation of protons in two models of the galactic regular magnetic field (with the irregular component included) assuming that the particles are injected by a short-lived discrete source lying in the direction of the galactic centre. We show that apart from a prompt image of the source, the regular magnetic field may cause delayed images at quite large angular distances from the actual source direction. The image is strongly dependent on the time elapsed after ejection of particles and it is also very sensitive to their energy. For the most favourable conditions for particle acceleration by a young pulsar, the ...
Monte Carlo calculations using the codes PENELOPE and GEANT4 have been performed to characterize the dosimetric parameters of the new 20 mm long catheter based $^{32}$P beta source manufactured by Guidant Corporation. The dose distribution along the transverse axis and the two dimensional dose rate table have been calculated. Also, the dose rate at the reference point, the radial dose function and the anisotropy function were evaluated according to the adapted TG-60 formalism for cylindrical sources. PENELOPE and GEANT4 codes were first verified against previous results corresponding to the old 27 mm Guidant $^{32}$P beta source. The dose rate at the reference point for the unsheathed 27 mm source in water was calculated to be $0.215 \\pm 0.001$ cGy s$^{-1}$ mCi$^{-1}$, for PENELOPE, and $0.2312 \\pm 0.0008$ cGy s$^{-1}$ mCi$^{-1}$, for GEANT4. For the unsheathed 20 mm source these ...
Volume sources is used for standard sources by radioactive measurement using Ge semiconductor detector of environmental sample, e.g. water, soil and etc. that require large volume. The commercial volume source used in measurement of the water sample is made of agar-agar, and that used in measurement of the soil sample is made of alumina powder. When the plastic receptacles of this two kinds of volume sources were damaged, the leakage contents cause contamination. Moreover, if hermetically sealing performance of volume source made of agar-agar fell, volume decrease due to an evaporation off moisture gives an error to radioactive measurement. Therefore, we developed the two type methods using unsaturated polyester resin, vinilester resin, their hardening agent and acrylicresin. The first type is due to dispersing the hydrochloric acid solution included the radioisotopes uniformly in ...
A multi-stage, multi-disk type seismic source was developed as a downhole seismic source. The seismic source is an improved version of the downhole seismic source of a system in which an elastic wave is generated by a weight accelerated by restitutive force of a spring striking the upper part of a laminated structure consisted of metal disks and elastic bodies installed in water in a well. Enhancing the vibration exciting efficiency requires impedance radiated from the disks to be increased. The multi-disk structure was adopted because of restrictions on the disk area under the limiting condition of being inside the well. Further limitation has still existed, which led to finally structuring the multi-disk type to a multi-stage construction to increase the radiated impedance. In order to increase average velocity on the radiation surface, mass relationship between the hammer and the anvil was sought so ...
We present a development of the use of the AAPM TG-43 dose formalism applied to "1"3"7Cs gynecological implant sources. The geometry factor, radial dose function, and anisotropy function of a "1"3"7Cs source modeled after the Nuclear Associates 67-809 series stainless steel jacketed tube source were derived following the AAPM TG-43 formalism. The dose rate distribution through the center of the source using the AAPM TG-43 dose formalism is calculated and compared with the calculations obtained using the Sievert summation and Monte Carlo simulation. The three methods resulted in an agreement within less than 5%, or an isodose rate line agreement within 2 mm. We demonstrate that the AAPM TG-43 formalism can be applied to "1"3"7Cs linear sources and is capable of serving as a "1"3"7Cs dose calculation algorithm that can be used for treatment planning purpose.
AGILE pointed observations performed from July 9, 2007 to October 30, 2009 are a recent, high quality gamma-ray data archive for monitoring studies of medium to high brightness gamma-ray sources in the 30 MeV -50 GeV energy range. We present a variability study of the 1AGL sources over the complete AGILE pointed Observation Blocks (OBs) dataset. The first AGILE Gamma-Ray Imaging Detector (GRID) catalog (Pittori et al. 2009) included a significance-limited (4 sigma) sample of 47 sources (1AGL), detected with a conservative analysis over a first-year non-uniform sky coverage dataset. In this analysis we used data of an improved full Field of View (FOV) event filter, on a much larger (about 27.5 months) observation dataset, analyzing each OB separatedly. This data processing resulted in an improved source list as compared to the 1AGL one. We present here some results on the variability of some of these ...
A multicusp magnetic field plasma surface ion source, normally used for H/sup /minus//ion beam formation, has been modified for the generation of high-intensity, pulsed, heavy negative ion beams suitable for a variety of uses. To date, the source has been utilized to produce mA intensity pulsed beams of more than 24 species. A brief description of the source, and basic pulsed-mode operational data, (e.g., intensity versus cesium oven temperature, sputter probe voltage, and discharge pressure), are given. In addition, illustrative examples of intensity versus time and the mass distributions of ion beams extracted from a number of samples along with emittance data, are also presented. Preliminary results obtained during dc operation of the source under low discharge power conditions suggest that sources of this type may also be used to produce high-intensity (mA) dc beams. The results ...
As there are many efforts devoted in order to manage the cancer, here the researcher handle one of these efforts that play a major part in treating the cancer internationally, it is a brachytherapy system. Brachytherapy was carried out mostly with radium sources, but recently some artificial sources are incorporated in this mode of treatment such as Cs-137, Ir-192, Au-198, P-32, Sr-90 and I-125. The research cover history of brachytherapy and radioactive sources used in, techniques of implementation, radiation protection and methods of brachytherapy dose calculation, as well as brachytherapy in radiation and isotopes centre in Khartoum.
Considering the hardware characteristics of the laser-induced plasma X-ray source and the limitations of the conventional cone-beam reconstruction algorithm, a general cone-beam reconstruction algorithm has been developed at our laboratory, in which the motion locus of the X-ray source is an arbitrary curve corresponding to at least a 2{pi} continuous horizontal angular displacement in the coordinate system of the specimen. The preliminary simulation shows that the general cone-beam reconstruction algorithm consistently results in visually satisfactory images.
Considering the hardware characteristics of the laser-induced plasma X-ray source and the limitations of the conventional cone-beam reconstruction algorithm, a general cone-beam reconstruction algorithm has been developed at our laboratory, in which the motion locus of the X-ray source is an arbitrary curve corresponding to at least a 2{pi} continuous horizontal angular displacement in the coordinate system of the specimen. The preliminary simulation shows that the general cone-beam reconstruction algorithm consistently results in visually satisfactory images.
Ammonia gas (NH{sub 3}) has been used as a nitrogen source for plasma source ion implantation processing of electroplated chromium. No evidence was found of increased hydrogen concentrations in the bulk material, implying that ammonia can be used without risking hydrogen embrittlement. The retained nitrogen dose of 2.1 {times} 10{sup 17} N-at/cm{sup 2} is sufficient to increase the surface hardness of electroplated Cr by 24% and decrease the wear rate by a factor of 4.
Two experiments are currently underway to measure the single-particle weak mixing matrix element for the 1064 KeV transition in "2"0"7Pb. One experiment measures the circular polarization of the 1064 KeV gamma ray emitted from an unpolarized source, while the other experiment measures the forward-backward asymmetry of gamma rays emitted from a polarized source. Analysis of the first set of polarized source data yields an upper limit of 46 eV for the single-particle weak mixing matrix element. copyright 1995 American Institute of Physics.
This paper presents calculations of the {sup 252}Cf-source-driven noise analysis measurements for subcritical highly enriched uranium metal cylinders using the Monte Carlo code MCNP-DSP. This code directly calculates the noise analysis data from the {sup 252}Cf- source-driven noise analysis method for both neutron and gamma ray detectors. Direct calculation of experimental observables by the Monte Carlo method allows for the benchmarking of the calculational model and the cross sections and for determining the bias in the calculation.
Average emittance data for ion beams extracted from cesium-sputter negative ion sources equipped with spherical, ellipsoidal, and cylindrical geometry cesium-surface ionizers are presented. The attributes of the respective source geometries are described in terms of their cesium ion optical properties. The results of recent measurement of the emittances of momentum-analyzed beams extracted from the ellipsoidal geometry source are also presented. These measurements indicate the presence of a species-dependent effect. The effect is believed to be attributable to differences in the energy spreads of the respective negative ion beams introduced by the sputter generation process.
Average emittance data for ion beams extracted from cesium-sputter negative ion sources equipped with spherical, ellipsoidal, and cylindrical geometry cesium-surface ionizers are presented. The attributes of the respective source geometries are described in terms of their cesium ion optical properties. The results of recent measurement of the emittances of momentum-analyzed beams extracted from the ellipsoidal geometry source are also presented. These measurements indicate the presence of a species-dependent effect. The effect is believed to be attributable to differences in the energy spreads of the respective negative ion beams introduced by the sputter generation process. 11 refs., 8 figs.
Technical Development Document supporting proposed water discharge regulations for the Coal Mining Industry authorized by the Clean Water Act. Proposed regulations include revised best practicable technology limitations, best available technology limitations and new source performance standards for the Coal Mining Industry. Industry operations include: coal preparation and amillary operations, active mining, F bituminous, anthracite and lignite coal, and the reclamation phase of mining.
... Biogas: The green gas? | EurActiv Biogas has become an attractive alternative source of energy in Europe as the renewable fuel ...Graduate Programme Research Analyst Junior Consultant Training Coordinator Post an EU job Biogas: The green gas? Published: 09 April 2010 |...Updated: 06 July 2010 Biogas has become an attractive alternative source of energy in Europe as the renewable fuel serves several policy priorities, ranging from ... Policy Summary Biogas is a renewable energy source that can be used for heating or electricity production. If compressed, it can ...
The physical foundations are described of radionuclide X-ray fluorescence analysis (RXFA) and the table shows the values of K- and L-absorption thresholds and the K- and L-line energies of elements. The calculation of the intensity of characteristic radiation during RXFA proceeds from relations derived for conventional X-ray fluorescence analysis. The choice of the radionuclide source is ruled by the nature of the analysed substance and the used detection technique. The diagram shows the areas of radionuclide sources and the energy of the fluorescence radiation of elements. The table shows the spectra of radionuclide sources suitable for the purposes of RXFA measured by semiconductor Si(Li) and Ge(Li) detectors. (ES).
Slide 10 Slide 11 23 ground-floor apartments Ancillary Information Gathered Median total PAH [mg/g] Slide 15 What are the principal sources of PAHs to urban lakes?...
Research at the world's accelerator- (storage-ring and linac) based light sources is one of the most dynamic and rapidly growing fields of science. It frequently results in direct benefits to society, thereby demonstrating the value of the research with very concrete examples, but this is not widely understood or appreciated outside of the immediate user community. Our growing group of light source communicators from facilities in Europe, Asia, and the Americas, inspired by the Interactions.org Web site created by high-energy (elementary-particle)physics communicators, concluded that a light source community Web site (lightsources.org) would be the best tool for establishing effective collaboration between the communications offices of the world's light sources and to maximize the impact of our efforts. We envision lightsources.org to serve as a one-stop-shopping site for information ...
BackgroundDuplications of stretches of the genome are an important source of individual genetic variation, but their unrecognized presence in laboratory organisms would be a confounding...Full Text Available
Skip to main content About USAID Locations Our Work Public Affairs Careers Business / Policy USAID: From The American People Policy USAID's 50th Anniversary Policy Home »...
and Vendors on the Web Bartleby.com "Great books online." Electronic Texts & Digital Libraries Links to the full text of books and other texts on the Web. Law and Politics...
from a broad range of sources including industrial and consumer products, food additives and drugs that never made it to the market to evaluate the predictive toxicity...
The growth power-time curves of a strain of petroleum bacteria, B-2, in various kinds of cultures containing different kinds of carbon sources, glucose, n-tetradecane, n-hexadecane and n-octadecane, and different kinds of microemulsions have been determined by using a 2277 Thermal Activity Monitor. The curves showed a single peak for cultures containing a single carbon source, glucose, and two peaks for cultures containing two kinds of carbon sources, glucose and one of the n-alkanes. The first peak indicated that bacteria grew by consuming glucose and the second peak indicated that bacteria grew by consuming n-alkane. The curves were complex when the bacterium grows in a microemulsion culture. According to a kinetic equation of bacterial growth under limited conditions, the rate constants of bacterial growth were obtained. The results showed that the microemulsion culture was more appropriate to bacteria to grow on ...
Mitochondrial superoxide production is an important source of reactive oxygen species in cells, and may cause or contribute to ageing and the diseases of ageing. Seven major sites of superoxide...Full Text Available
Local anesthetics are frequently administered in dentistry and thus can be expected to be a major source of drug-related complications in the dental office. Additionally, the dentist will more often...Full Text Available
BackgroundElementary schools represent both a source of childhood sun exposure and a setting for educational interventions.MethodsSun Protection...Full Text Available
BackgroundWith the exception of vertebrates, most organisms have plasma membrane associated ammonium transporters which primarily serve to import a source of nitrogen for nutritional...Full Text Available
Streptococcus agalactiae continues to be a major cause of subclinical mastitis in dairy cattle and a source of economic loss for the industry. Veterinarians are often asked to provide information on...Full Text Available
In this talk, we summarize recent results obtained from the combined neutrino telescopes IceCube and AMANDA. The combined approach, including data taken from both detectors simultaneously, is compared to other analyses that are using IceCube only data. The main benefit of the combined detector is its improved performance at low energies, meaning energies below 1 TeV (close to the energy threshold of the detector). The discussion is focused on the search for extra-terrestrial neutrinos from candidate sources in our Galaxy. Using appropriate cuts, the sensitivity can be optimized for soft spectra neutrino sources. With the resulting data sample, several studies are performed: an unbinned Galactic Plane Scan and a Cygnus region analysis: the Multi Point Source analysis. The current status of these analyses is presented.
High resolution of NMR spectroscopic data of biosamples are a rich source of information on the metabolic response to physiological variation or pathological events. There are many advantages...Full Text Available
The installation and performance of a water source heat pump in Minnesota are discussed. The operating cost was found to be higher than expected. (MHR)
... stenosis. It looks from the transesophageal and the 3-D echo that most of the problem is really ... posterior leaflet, which you can see on the 3-D echo image is a major source. The anterior ...
This document is a collection of spreadsheets detailing on a county by county basis the agricultural crop, agricultural wastes, municipal wastes, and industrial wastes of Virginia that are potential biomass energy sources.
This document is a collection of spreadsheets detailing in a county by county manner the agricultural crop, agricultural wastes, municipal wastes and industrial wastes in Florida that are potential biomass energy sources.
This document is a collection of spreadsheets detailing on a county by county basis the agricultural crop, agricultural wastes, municipal wastes and industrial wastes of Alabama that are potential biomass energy sources.
... The goal of filtering (the sequential Bayesian ... 5] and the unscented Kalman filter (UKF) [16 ... set of deterministically chosen sample (or sigma) points. ...
BackgroundHealth service databases of administrative type can be a useful tool for the study of progression of a disease, but the data reported in such sources could be affected...Full Text Available
... that range from relatively low frequency strong ground motion modeling [Vidale et al., 1985] to high frequency reverse time migration of seismic ...
Solid-state single-photon sources have many desirable features that make them attractive for applications in quantum information processing. However, the phase coherence of such devices can be severely compromised by coupling to the solid-state environment. Here, we study the effects of realistic dephasing environments on a pair of solid-state single photon sources in the context of quantum interference effects such as the Hong-Ou-Mandel dip. By means of exact solutions for the non-Markovian dynamics of the sources, we show that the resulting loss of visibility depends crucially on the timing of photon detection events. Our results demonstrate that the effective visibility can be improved via temporal post-selection, and also that time-resolved interference can be a useful probe of the interaction between the emitter and its host environment.
light-emitting diode A light-emitting diode, or LED, is a semi-conductor light source that emits visible light or invisible infrared radiation. Semi-conductors ...
A miniature x-ray source utilizing a hot filament cathode. The source has a millimeter scale size and is capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature source consists of a compact vacuum tube assembly containing the hot filament cathode, an anode, a high voltage feedthru for delivering high voltage to the cathode, a getter for maintaining high vacuum, a connector for initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is fabricated from highly x-ray transparent materials, such as sapphire, diamond, or boron nitride.
... the open source OpenMap Java toolkit from BBN ... 2001), Handbook of Multisensor Data Fusion ... Oxenham (2002), Sensor Registration Using Airlanes ...
Investigation of the Macrokinetics and Energy of Self-Oscillatory Processes of Gasless Combustion of Solid Fuel Mixtures Proposed for the Design of Short-Term Thermal and Electrical Sources
familiarity fire triangle (i.e., fuel, oxidant, and ignition source) are excluded. It Is obvious that for the baseline safety goal for spacecraft this ...
Little is known about the state of experimentation in the field of medicine during the Medieval Islamic era. With few exceptions, most of the contemporary sources on history of medicine propagate the...Full Text Available
Objective and sourcesWe reviewed the epidemiologic literature for PFOA.Data synthesisPerfluorooctanoic acid (PFOA) does not occur naturally but is...Full Text Available
... Environmental Assessment of Proposed Effluent Limitations Guidelines and Standards for the Meat and Poultry Industry Point Source; EPA-821-B-01-008; US ...
discharges. Proposed Stormwater ELG from Construction Sites - EPA has proposed effluent limitations guidelines (ELGs) and new source performance standards (NSPS) to control...
Proton exchange membrane (PEM) fuel cells are energy sources that have the ... for H2 /02 PEM fuel cells because their catalysts have properties suitable for 0 ...
Monte Carlo calculations using the codes PENELOPE and GEANT4 have been performed to characterize the dosimetric properties of monoenergetic photon point sources in water. The dose rate in water has been calculated for energies of interest in brachytherapy, ranging between 10 keV and 2 MeV. A comparison of the results obtained using the two codes with the available data calculated with other Monte Carlo codes is carried out. A chi2-like statistical test is proposed for these comparisons. PENELOPE and GEANT4 show a reasonable agreement for all energies analyzed and distances to the source larger than 1 cm. Significant differences are found at distances from the source up to 1 cm. A similar situation occurs between PENELOPE and EGS4.
1 Recommendations for correct therapy with digoxin from twenty-five sources are reviewed. 2 Some recommendations may be unsuitable for use with high bioavailability...Full Text Available
A new methane cold neutron source has been tested at the IBR-2 pulsed reactor at the Frank Laboratory of Neutron Physics. In a paper the results of experiments at neutron diffractometers HRFD and DN-2 which are placed at the IBR-2 from the methane moderator side are given. A comparison with the results obtained with the conventional water comb-like moderator is performed. The perspectives of the cold source for various kinds of neutron diffraction experiments, including atomic and magnetic structural analysis and real time experiments are discussed. It is shown, that for a huge number of the experiments which are performing at both HRFD and DN-2 the methane cold neutron source provides the better conditions than water comb-like moderator.
The development of a new configuration of chemical ionization (CI)-based ion source is presented. The ambient air containing the gaseous sample is sniffed into an enclosed ionization chamber which is of sub-ambient pressure, and is subsequently mixed with metastable species in front of the ion inlet of the mass spectrometer. Metastable helium atoms (He*) are used in this study as the primary ionizing agents and are generated from a dielectric barrier discharge (DBD) source. The DBD is powered by an AC high-voltage supply and the configuration of the electrodes is in such a way that the generated plasma is confined within the discharge tube and is not extended into the ionization chamber. The construction of the ion source is simple, and volatile compounds released from the bulky sample can...
Numerous bacteria from a salt-marsh environment are capable of degrading malathion, an organophosphate insecticide, when supplied with additional nutrients as energy and carbon sources. Seven isolates...Full Text Available
A project is underway at Oak Ridge National Laboratory (ORNL) to design, test, and install a cold neutron source facility in the High Flux Isotope Reactor (HFIR). This new cold source employs supercritical hydrogen at cryogenic temperatures both as the medium for neutron moderation and as the working fluid for removal of internally-generated nuclear heating. The competing design goals of minimizing moderator vessel mass and providing adequate structural integrity for the vessel motivated the requirement of detailed multidimensional thermal-hydraulic analyses of the moderator vessel as a critical design subtask. This paper provides a summary review of the HFIR cold source moderator vessel design and a description of the thermal-hydraulic studies that were carried out to support the vessel development.
... increasing its economic results, tapping mew financial sources and augmenting its income, but also a basic task in financial and tax management. ...
Following a brief overview of the terrestrial distribution of boron in rocks, soil, and water, the history of the discovery, early utilization, and geologic origin of borate minerals is summarized....Full Text Available
Fire-driven deforestation is the major source of carbon emissions from Amazonia. Recent expansion of mechanized agriculture in forested regions of Amazonia ...
A method and apparatus for determining the condition of tissue or otherwise making chemical identifications includes exposing the sample to a light source, and using a synchronous luminescence system to produce a spectrum that can be analyzed for tissue condition.
... applications related to military and intelligence area ... the technology solved yet, but the open issue still ... fields, columns; ie data source, document type ...
Hydrogen peroxide is a commonly used oxidizing agent with a variety of uses depending on its concentration. Ingestion of hydrogen peroxide is not an uncommon source of poisoning, and results in morbidity...Full Text Available
A collection of cost estimating relationships (CER's) and their proprietary database sources. The cost estimating relationships can be used in the aerospace ...
... with dynamic gridding capability to account for material ablation, as well as the addition of energy sources and heat transfer augmentation due to ...
Maintaining efforts at the end of a very average year in terms of tonnages marketed, maintaining a high degree of vigilance art responsiveness in the face of competition from other energy sources, emphasizing the exemplary safety of industrial plant, and playing an increased role as a source of proposals within the context of dialogue with the authorities in the current environment of stricter regulations. (author)
Diffuse celestial sources of relatively low surface brightness such as the Milky Way, zodiacal light, and gegenschein (or contre lumière) can be studied most reliably from above...Full Text Available
We review the status of free electron laser (FEL) research being conducted at LBL and LLNL as part of a broader program of research on two beam accelerators (TBAs). Induction accelerator-driven FELs for use as power sources for high-gradient accelerators are discussed, along with preliminary cost estimates for this type of power source. Finally, a promising new version of an FEL/TBA is described. 25 refs., 1 fig., 3 tabs.
This research validates a novel approach for source tracking based on denaturing gradient gel electrophoresis (DGGE) analysis of DNA extracted from Escherichia coli isolates. Escherichia coli from different animal sources and from river samples upstream from, at, and downstream of a combined sewer overflow were subjected to DGGE to determine sequence variations within the 16S-23S intergenic spacer region (ISR) of the rrnB ribosomal operon. The ISR was analyzed to determine if E. coli isolates from various animal sources could be differentiated from each other. DNA isolated from the E. coli animal sources was PCR amplified to isolate the rrnB operon. To prevent amplification of all 7 E. coli ribosomal operons by PCR amplification using universal primers, sequence-specific primers were utilized for the rrnB operon. Another primer set was then used to prepare samples of the 16S-23S ISR for DGGE. Comparison ...
An irradiation head with sample holders is described and measurement geometry is reported. Measurements were made for optimizing the distance between the source and the sample and for optimizing the sample diameter. The optimal distance between the source and the sample does not depend on the collimator diameter. The sample diameter should not exceed 30 - 35 mm. Sensitivity and detection limits were determined for Zn, Pb and Br and calibration curves were plotted. (M.D.) 6 figs., 2 tabs., 4 refs.
Atmospheric and ionospheric perturbations associated with the acoustic-gravity waves (AGW) with typical frequencies of a few hertz -millihertz are considered. These events may be caused by the influence from space and atmosphere as well as by oscillations of the Earth surface and other near-surface phenomena. The surface sources include long-period oscillations of the Earth's surface, earthquakes, explosions, thermal heating, seisches and tsunami waves. The wavelike phenomena manifest themself as travelling disturbances of air (in the atmosphere) and of electron density (in the ionosphere). Travelling ionospheric disturbances (TIDs) are well detected by radio physical methods. AGW generation by near-surface sources is modeled by the numerical solution of the equation of geophysical fluid dynamics for different sources in two-dimensional non-linear dissipative compressible atmosphere. The numerical calculations are based on ...
We discuss optimal detection of fast radio transients from astrophysical objects while taking into account the effects of propagation through intervening ionized media, including dispersion, scattering and scintillation.Our analysis applies to the giant-pulse phenomenon exhibited by some pulsars, for which we show examples, and to radio pulses from other astrophysical sources, such as prompt radio emission from gamma-ray burst sources and modulated signals from extra-terrestrial civilizations.
A project to demonstrate residential heating and cooling with a well-water source heat pump is documented. The system is schematically illustrated and described, and project experience is discussed. The system is capable of using source water as cool as 40/sup 0/F. Project expenses are accounted for. (LEW)
Brachytherapy consists of sealed radioactive source implantation. The diversity in the nature of radioelements, in their energy and activity requires strict implantation and utilization rules. These rules include radioactive source physical parameters check, after-loading machine and treatment planning system quality assurance and safe and reproducible dosimetric systems. Patient and medical workers information guarantee radioprotection and prevention of accidental exposures. (authors)
This comprehensive guide offers several tried and true steps to help you successfully manage the complex process of developing free software. Topics include project management, developer motivation, technical infrastructure to support collaboration, and project promotion. Producing Open Source Software is ideal for developers starting their own free software projects, or people who simply want to participate in the process.
Daya Bay Nuclear Power Station has made a series of tries and efforts on radiation source control and benefited from them since it was put into commercial operation. Some of them were introduced from experience feedbacks of foreign nuclear power industry and others came from our own good practices
One-velocity angular flux of a neutron field generated by a polarly anisotropic point source in an infinite homogeneous region is calculated in P3 approximation, using the spherical harmonics operator formalism adapted to two-dimensional spherical geometry. The problem is reduced to simple algebraic equations. For weak absorption and linearly anisotropic scattering, the solution is given in closed form. (orig.).
The change of the transport coefficient due to the fusion energy source is studied. The scale invariance property of the reduced set of equations is investigated in the presence of the self-heating term due to the fusion reaction. The pressure gradient as well as the fusion power are the free energy sources that dictate the turbulent transport. It is shown that the burning transport coefficient can have a form with much wider variety, and that the transport property could be different owing to the self-heating by the fusion reactions. (author)
In this report is described the sources to nitrogen emission and how the emission have changed over time. The cost and effect of the proposals given by the Swedish Environmental Protection Agency to cope with the emission of nitrogen to the sea is also treated. A separate chapter describes what we know today about phosphorus and eutrophication Basic document to report SNV--4735. 25 figs, 11 tabs
A brilliant X ray source is proposed for lithography instruments with use of a multi-mirror system. The inverse Compton scattering between the stored electron beam in the storage ring and the stored photon beam in the multi-mirror system, is applied for the X-ray generation. (author)
The proliferation of 'botnets,' phishing schemes, denial-of-service attacks, root kits, and other cyber attack schemes designed to capture a system or network creates a climate of concern for system administrators, especially for those managing accelerator and large experimental-physics facilities, as they are very public targets. This paper will describe the steps being taken at the Advanced Photon Source (APS) to protect the infrastructure of the overall network with emphasis on security for the APS control system.
Hydrology and hydrogeochemical are auxiliary techniques to valid conceptual hydrogeology an recharge models. Stable isotopes from water trace sources and path flow and Tritium indicates age. This paper is about the use of D 18, D2H y 3H to study the aquifer system on Bajo Cauca antioqueno.
High-brightness negative ion beams, especially O{sup -} beams, from a compact gaseous plasma source are studied to evaluate the suitability for high-resolution SIMS. Ion-optical calculations are made using the beam parameters from the new source. Results suggest that sub-100 nm spot with O{sup -} beam current of 10 pA is achievable. Beam focusing, the resulting beam current distributions at the target and the expected instrumental performance are discussed.
Fe, Mn, Ni, V, Ti and Mo were determined in aerosols from manual arc welding. Samples of welding aerosols were trapped on a Synpor 4 filter. The amount of determined elements in aerosols was detected using the method of radionuclide X-ray fluorescence analysis. A /sup 241/Am annular source was used as the source of excitation radiation and radiation was processed using a Si(Li) spectrometer.
Fe, Mn, Ni, V, Ti and Mo were determined in aerosols from manual arc welding. Samples of welding aerosols were trapped on a Synpor 4 filter. The amount of determined elements in aerosols was detected using the method of radionuclide X-ray fluorescence analysis. A "2"4"1Am annular source was used as the source of excitation radiation and radiation was processed using a Si(Li) spectrometer. (E.S.).
Power generated by manufacturers and third-party suppliers in venture capital projects is available to military and other government users at a cost 10 to 20% lower. Tax benefits and other financial incentives keep suppliers' costs low. Users are required to contract for a minimum amount of energy over a 20- to 30-year period. Military use of these energy projects includes sources based on solar energy, cogeneration, geothermal heat, and refuse-derived fuel. (DCK)
Radioactive ion beams (RIBs) of short-lived isotopes of fluorine are in demand for investigating astrophysical phenomena related to the hot CNO cycle and rp processes responsible for stellar nucleosynthesis. Since negative ion beams are required for injection into tandem electrostatic accelerators, such as the 25 MV tandem accelerator used for post acceleration of RIBs for the Holifield Radioactive Ion Beam Facility (HRIBF) research program at the Oak Ridge National Laboratory (ORNL), efficient, direct-formation F{sup -} ion sources are highly desirable for RIB applications involving this type of post-accelerator. We have conceived and evaluated a direct extraction F{sup -} source for potential RIB applications which is predicated on the reverse polarity operation of a positive electron-beam-plasma target/ion source (EBPTIS) while simultaneously feeding fluorine rich compounds and Cs vapor into the ...
This study analyzes the economic impact that could result from the application of effluent standards and limitations issued under Sections 301, 304, 306, 307 of the Clean Water Act to the pulp, paper, and paperboard industry, including builders' paper and roofing felt manufacturing.
Distribution of scattered elements in basic minerals of salt-rocks is studied. It is shown that rubidium and cesium are accumulated mainly in carnallites and are contained in small quantities halites. These elements are accumulated primarily in the carnallite production products, wherein their content in a number of cases exceeds by dozens and hundred times their content in source rocks. It is noted that only carnallites may be considered in the list of actual sources for rubidium and cesium separation
This paper describes the research and development activities in three areas of radiation processing, namely: food irradiation, medical product sterilization and wood plastic combination. Plans and efforts exerted to acquire a larger gamma source to augment our present 5,000 curie source are discussed. Cost estimates for a radiation facility are presented on the basis of the market potential of food irradiation and medical product sterilization. Existing local industries that can benefit from the adaptation of irradiation technology in their processing requirements are described.
Brachytherapy is used for treating certain types of cancer by inserting radioactive sources into tumours. CDTN/CNEN is developing brachytherapy seeds to be used mainly in prostate cancer treatment. Dose calculations play a very significant role in the characterization of the developed seeds. The current state-of-the-art of computation dosimetry relies on Monte Carlo methods using, for instance, MCNP codes. However, deterministic calculations have some advantages, as, for example, short computer time to find solutions. This paper presents a software developed to calculate doses in a two-dimensional space surrounding the seed, using a deterministic algorithm. The analysed seeds consist of capsules similar to IMC6711 (OncoSeed), that are commercially available. The exposure rates and absorbed doses are computed using the Sievert integral and the Meisberger third order polynomial, respectively. The software also allows the isodose visualization at the surface plan. The ...
A large IMF- and event characterizing multidetector system (CHICSI) is under development for storage ring experiments. In ''test'' experiments with telescopes of CHICSI type the IMF production has been measured for "1"4N induced reactions at 14A and 32A MeV. Detailed information about the emission sources, particularly from the IMF yield in reactions with isotope separated targets and from isobaric yield ratios in the sub-Coulomb region is discussed. (orig.).
The electron beam ion source (EBIS) at Texas A and M University was constructed and is currently undergoing tests on the injection and transmission of the electron beam through the solenoid. Results of computer simulation of the electron beam are presented, as well as measurements of electron beam profiles using a pinhole beam analyzer.
The inevitability of sustainable economic development and its linkage to a gradual shift to renewable energy sources, especially solar energy, was discussed. Means to measure sustainability of technology were described, and policy instruments (essentially research, development and demonstration, and punitive taxes on conventional energy carriers) to accelerate the shift to renewable energy sources were outlined.
The apex dimensions and length are calculated as a function of current for the ion-emitting jet in liquid-metal ion sources (LMIS). The results agree well with observations. Since the final expressions are analytical, they give more insight into the fundamental mechanisms involved than do numerical calculations. Some implications of the model are discussed concerning focused ion beam (FIB) systems employing LMIS. (author).
Clastic sediments of Albian age provide hydrocarbon source rocks, reservoirs and seals. Major reservoirs occur in sandstones to the north, and have a limited reservoir potential in offshore Qatar. Distal shales are a major seal in offshore Qatar, the United Arab Emirates and Oman. Local source-rock potential exists in the northern part of the Arabian Gulf and in the extreme SE of Saudi Arabia (in the Rub Al Khali Basin). (author)
The work reported in this paper addresses the problem of structure-borne sound transmission between vibrating sources and ribbed-plate receiver structures. Vibrating sources, such as pumps, motors, fans, etc., transmit vibro-acoustic power, causing noise complaints by occupants in cars, trains, aircraft, buildings and/or material fatigue and damage. The transmission process is complicated in that sources transmit power through several contacts and by up to six components of excitation at each contact. The structure-borne sound power is a function of source activity, source mobility and receiver mobility, and all three quantities must be known to some degree. For non-homogeneous receiver structures, such as thin-plate cavity constructions or lightweight framed constructions, the sheathing plates are typically fastened to the framing members using bolts, screws or spot-welded joints. ...
Full text: Recent geoarchaeological research in the Erzurum district, north-eastern Anatolia, has revealed an abundance of obsidian at numerous neolithic and Bronze Age sites. Geochemical characterisation using neutron activation analysis indicates that the obsidian was obtained from several sources that are chemically distinct from the major sources already known from Central Anatolia an the Lake Van area. Multiple sources are represented in the samples collected from at least two of the sites, namely the sites of Sos and Pulur. The primary source of some of the obsidian utilised at the site of Sos has been located in the volcanic sequence outcropping tot he north-west of Pasinler. Field survey however has shown that the alluvial deposits along the main rivers and some of their tributaries were the main sources of the obsidian utilised at the sites near Erzurum. Trade or exchange ...
In the High Flux Reactor (HFR) at Grenoble a new horizontally arranged cold neutron source will be installed that uses liquid deuterium (D_2) as the moderator for cold neutrons. This cold source should provide a high neutron flux, it should be simple in design, and be characterized by high reliability and by safe operation. A high neutron flux calls for installation of the cold source near the HFR core and good moderation requires a D_2 volume of #DELTA#5 litres. Hence, the moderator, contained in a horizontally arranged cylindrical cell of 21 cm diameter and 20 cm length, is installed at the end nearest to the core of a horizontal beam tube of roughly 4.5 m length with an inner diameter of only 23 cm (Fig. 1). The HFR will be equipped with a second cold neutron source. The installation in the existing horizontal beam tube together with the amount of heat released determined the problems to be solved: ...
A thermoluminescence (TL) sheet and its spatial readout system for in vivo measurement of spatial dose distribution around sources has been newly developed for intracavitary high dose-rate radiation therapy. The TL sheet (40 cm x 50 cm x 200 {mu}m), which is composed of teflon mixed with BaSO{sub 4} (Eu doped) powder, has a linear response with a very wide dynamic range from at least 0.002 cGy to 5000 cGy for {sup 60}Co sources. Phantom test of the TL sheet readout system demonstrated that absorbed dose with TL sheet and that with ionization chamber as standard dosimeter agreed well. For clinical application, TL sheet was attached on an applicator of intracavitary radiation therapy for rectal cancer. After irradiation with high dose-rate {sup 60}Co sources, the in vivo dose distribution on the surface of the rectum was determined. The TL sheet was suggested to provide a convenient means of measuring the dose distribution ...
The detection efficiency of gamma scanning system in irradiated materials examination facility has been measured. Gamma-ray sources used in this experiment are Cs-Co standard sources a PWR spent fuel rod in which {sup 134}Cs and {sup 154}Eu peaks are clearly identified in the energy region of 500 to 1,600 keV. The distance between source and detector is about 1.6 m. A slit type collimator with 3 mm-width window and 30 mm-thick lead block are installed between source and detector. The detector is a HPGe detector. This equipment is mainly used in gamma scanning of irradiated nuclear fuel. The measured detection efficiency seems to be 1.89 x 10{sup -6} % for 1 MeV gamma-ray. With these results the activities of unknown sources could be measured. This results are expected to be used in the measurement of the absolute distribution of gamma emitting nuclides in nuclear fuel.
A brief description of a method for producing relatively intense molecular negative ion beams for the difficult Group IIA elements is given which offers considerable improvement in terms of source operation and beam intensity stability over other methods conventionally utilized. It is particularly suited for use in cesium plasma sources such as the Aarhus geometry and axial geometry versions of the source. The method utilizes H/sub 2/ source feed gas for the production of a hydrogen-rich plasma discharge which sputters a negatively biased probe made of elemental or copper alloy material. Negative ion beams of MgH/sub 3//sup -/>=12 ..mu.. A have been realized during routine operation of the 25 MV tandem accelerator. Negative ion beam intensity data, typical source operational parameters, and examples of mass spectra associated with their production are given. Interesting ...
This research focuses on the development and application of high order statistical analyses applied to measurements performed with subcritical fissile systems driven by an introduced neutron source. The signatures presented are derived from counting statistics of the introduced source and radiation detectors that observe the response of the fissile system. It is demonstrated that successively higher order counting statistics possess progressively higher sensitivity to reactivity. Consequently, these signatures are more sensitive to changes in the composition, fissile mass, and configuration of the fissile assembly. Furthermore, it is shown that these techniques are capable of distinguishing the response of the fissile system to the introduced source from its response to any internal or inherent sources. This ability combined with the enhanced sensitivity of higher order signatures indicates that these ...
The quasar B2005+403 located behind the Cygnus region, is a suitable object for studying the interplay between propagation effects, which are extrinsic to the source and source intrinsic variability. On the basis of VLBI experiments performed at 1.6, 5, 8, 15, 22, and 43GHz between 1992-2003 and parallel multi-frequency monitoring of the total flux density, we investigated the variability of total flux density and source structure. Below 8 GHz, the point-like VLBI source is affected by scatter-broadening of the turbulent interstellar medium, which is located along the line of sight and likely associated with the Cygnus region. We present and discuss the measured frequency dependence of the source size, which shows a power-law with slope of -1.91+/-0.05. From the measured scattering angle at 1GHz of 77.1+/-4.0mas a SM=0.43+/-0.04 m^{-20/3} kpc is derived, consistent with the general ...
An International Workshop on Metrology for X-ray and Neutron Optics has been held March 16-17, 2000, at the Advanced Photon Source, Argonne National Laboratory, near Chicago, Illinois (USA). The workshop gathered engineers and scientists from both the U.S. and around the world to evaluate metrology instrumentation and methods used to characterize surface figure and finish for long grazing incidence optics used in beamlines at synchrotrons radiation sources. This two-day workshop was motivated by the rapid evolution in the performance of x-ray and neutron sources along with requirements in optics figure and finish. More specifically, the performance of future light sources, such as free-electron laser (FEL)-based x-ray sources, is being pushed to new limits in term of both brilliance and coherence. As a consequence, tolerances on surface figure and finish of the next generation of ...
Ground-source heat pump systems (GSHPSs), also referred to as geothermal heat pump systems (GHPSs), have been widely used in residential and commercial buildings for years due to their outstanding energy utilization efficiencies. In this study, an energy and exergy modeling of solar assisted ground-source heat pump systems for residential applications is presented for system analysis and performance evaluation. In this regard, the performance of a solar assisted ground-source heat pump heating system, installed in Solar Energy Institute of Ege University, Izmir, Turkey, is evaluated based on the actual operational data to show how energy and exergy efficiencies values change with the system. The average heating coefficient of performances (as energy efficiencies) of the solar assisted ground-source heat pump (GSHP) unit and the overall system are obtained to be 2.64 and 2.38, respectively. The average ...
The consequences of converting a facility from brown coal fuel to gas fuel were analyzed by model simulation. Treated were a district heating plant with an output of 700 TJ/yr and minor local heating sources (stoves) at a density of 1 family house per 100 m"2. Emissions of particulate matter, sulfur dioxide, nitrogen oxides, carbon monoxide, and hydrocarbons before and after the conversion are given for the two types of source. Conversion of a major air pollution source to gas fuel would result in a reduction of the contribution of sulfur dioxide emissions of the order of 10"-"4, of particulate matter and carbon monoxide of the order of 10"-"3, and of hydrocarbons of the order of 10"-"2. The decrease will be lowest for nitrogen oxides, viz. about 40%. Analogous data for local heating sources in towns would be 10"-"5 for sulfur dioxide, 10"-"4 for particulate matter, 10"-"3 for carbon monoxide and ...
A method for determining the reactivity of subcritical systems of fissile material, using neutron-noise power spectral density measurements in conjunction with a /sup 252/Cf source, has been tested in experiments with an aqueous solution containing uranium fluoride (4.95 wt% /sup 235/U). The kappasub(eff)-values obtained from the ratio of spectral densities G*/sub 12/G/sub 13//G/sub 11/G/sub 23/ agreed with those from break-frequency noise analysis and with bias-corrected transport theory calculations within the statistical uncertainty of the measurements. Corrections for the effects of spatial modes and source-detector locations appear to be well-understood, since measurements for a variety of source-detector positions resulted in essentially the same kappasub(eff)-values. Modal correction factors were such that ignoring them would result in higher values of kappasub(eff) than actually occur. The measurements have ...
The BNL Neutral Beam Development Group has been active in the program for the development of high energy, high power neutral beam systems since 1973. These injectors are based on the production, acceleration and neutralization of negative hydrogen or deuterium ions and are supposed to be used for plasma heating and current drive in the next generation of fusion devices. Over the span of 10 years the group has studied plasma-surface type of negative hydrogen ion sources, transport and acceleration of negative ion beams and neutralization of negative ions in gases and plasmas. As the required source parameters (current, pulse length, efficiency) were changing over this period of time, the group developed several types of sources, resulting finally in the design of a steady state device operating with an excellent gas efficiency and having the possibility of scaling-up to the size necessary for a high power neutral beam ...
Jordan is an example of a third world country that is non-oil producing but contains huge reserves of other energy sources such as tar sand, oil shale, and olive cake. Some limited research is available about how to utilize these energy sources in pure form. However, available research does not deal with combinations of these energy sources. This experimental study investigates combinations of these energy forms as potential energy sources in Jordan. The experimental procedure involves characterization of samples by proximate analysis, calorific value determination of different combinations, and a compacting process of the different particles. The best combination, with respect to calorific value, is found to be 20% tar sand, 20% olive cake, and 60% oil shale. Compacting materials either with starch or with heated tar sand up to 110{sup o}C for 1 h indicates a feasible process for handling, packaging, ...
Plutonium-containing compounds vary widely in isotopic content, and as a result, the dose as function of isotopic content also varies considerably. Determination of the dose from neutrons, decay and capture gammas from plutonium in the form of compounds thus requires that the spontaneous fission and ({alpha},n) source and spectra from each individual isotope be known. To facilitate dose calculations from plutonium-containing compounds, we have calculated the spontaneous fission and ({alpha},n) sources and spectra for 1 g of each of the plutonium isotopes in the form of either PuF{sub 4} or PuO{sub 2}. As {sup 241}Am is often a component in a mixture of plutonium isotopic compounds, the source and spectra from 1 g of {sup 241}Am mixed with PuF{sub 4} or PuO{sub 2} has also been determined. Using these results, the neutron source and spectra may be determined for any sample composition. 2 refs., 3 tabs.
This thesis consists of an introduction and five included papers. Of these, four papers are published in international journals and the fifth was submitted for review in April 2000. Emphasis has been placed on both naturally and artificially generated light hydrocarbons in petroleum fluids and their proposed source rocks as well as direct application of light hydrocarbons to oil/source rock correlations. Collectively, these papers describe a strategy for interpreting the source of the light hydrocarbons in original oils and condensates as well as the source of the asphaltene fractions from the reservoir fluids. The influence of maturity on light hydrocarbon composition has also been evaluated. The papers include (1) compositional data on the light hydrocarbons from thermal extracts and kerogen pyrolysates of sediment samples, (2) light hydrocarbon data of oils and condensates as well as the pyrolysis ...
The results of the 2006 investigation of contaminant sources at Navarre, Kansas, clearly demonstrate the following: {sm_bullet} Sources of carbon tetrachloride contamination were found on the Navarre Co-op property. These sources are the locations of the highest concentrations of carbon tetrachloride found in soil and groundwater at Navarre. The ongoing groundwater contamination at Navarre originates from these sources. {sm_bullet} The sources on the Co-op property are in locations where the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) never conducted grain storage operations. {sm_bullet} No definitive sources of carbon tetrachloride were identified on the portion of the current Co-op property formerly used by the CCC/USDA. {sm_bullet} The source areas on the Co-op property are consistent with the locations ...
A new generation of quasimonochromatic high-flux X-ray sources, based on the X-ray radiation produced through Compton scattering between an electron beam and a laser beam, is under development. One of the possible applications of this source is inline phase contrast mammography, based on the observation of the edge-enhancement effect that can be observed at the border of structures inside the breast in images produced using a partially or totally coherent X-ray beam. In this work we present the results of a set of simulations of inline phase contrast mammography using typical inverse Compton scattering sources parameters. The simulated sample was a tumour-like mass having spherical shape, diameter between 200 {mu}m and 5 mm, placed inside a breast-like matrix, 4 cm thick, and a standard composition of 50% glandular tissue and 50% adipose tissue. We discuss the minimum requirements for mammography using inverse Compton ...
The lakes formed in the Amazon floodplain play a key role in sustaining the highest populational density in the Amazon Basin because of its high primary productivity. The water volume in these lakes vary greatly during the year and possible water sources are the feeding river during high water state of the hydrographs and local inputs from its drainage basin. As these sources are chemically distinct, to understand the nutrient dynamics in these lakes, it is very important to know the relative water contribution of different water sources. In this paper we use "1"8O as a conservative to know the water sources for the lakes and our hypothesis is that: 1) In the high water stage lake water is derived predominantly from its feeding river. Therefore their #delta#"1"8O should be similar. 2) In the low water stage lake water is a mixture of watershed and last flood event waters. In this case, lake #delta#"1"8O ...
The genetic type, source and charging history of natural gas in the Yulin gas field in the Ordos Basin have been studied by combining the carbon isotopic composition of natural gas and geochemical characteristics of light hydrocarbons with carbon isotope fractionation model results and fluid inclusion analysis. The carbon isotopic composition of methane and ethane in the Yulin gas field is relatively enriched in {sup 13}C with {delta}{sup 13}C{sub 1} values ranging from - 35.3 permille to - 29.8 permille (average value = - 32.4 permille) and {delta}{sup 13}C{sub 2} ranging from - 26.3 permille to - 23.5 permille (average value = - 24.8 permille). The C{sub 7} light hydrocarbons are predominated by methylcyclohexane, accounting for 65.8% to 80.9% (average value = 71.6%), which is characteristic of coal-derived gas. Furthermore, the gas geochemistry indicates that, although marine limestone source rocks are present in the region, the contribution ...
Renewable energy technologies such as photovoltaics, solar thermal power plants, and wind turbines are nonconventional, environmentally attractive sources of energy that can be considered for electric power generation. Many of the areas with abundant renewable energy resources (very sunny or windy areas) are far removed from major load centers. Although electrical power can be transmitted over long distances of many hundreds of miles through high-voltage transmission lines, power transmission systems often operate near their limits with little excess capacity for new generation sources. This study assesses the available capacity of transmission systems in designated abundant renewable energy resource regions and identifies the requirements for high-capacity plant integration in selected cases. In general, about 50 MW of power from renewable sources can be integrated into existing transmission systems to supply local loads ...
The subcriticality of two interacting solution tanks was determined using /sup 252/Cf-source-driven neutron noise analysis methods. These experiments were the first test of this method for an interacting system with materials (in this case, uranyl nitrate) typical of nuclear materials in processing plants. The experiments were performed to test the conclusions from previous interaction experiments with uranium metal discs for a fissile system with moderation, and to provide data to test theoretical models for coupled systems. The uranium metal experiments showed that the subcritical neutron multiplication factor, k/sub eff/, could be determined using point kinetics without any correction for spatial effects from measurements with the source and detectors located adjacent to the same cylinder, whereas for source-detector configurations with either the source and/or detectors adjacent to different ...
Purpose: The purpose of this course is to review the physical principles underlying design, clinical application and execution of interstitial and intracavitary implants in the classical low dose-rate (LDR) range. This year, the course will focus on quality assurance of sources, applicators and treatment planning software. In addition, development of procedures and QA checks designed optimize treatment delivery accuracy and patient safety during each individual procedure will be reviewed. The level of presentation will be designed to accommodate both physicists and physicians. Implementation of recently published AAPM Task Group reports (no. 40, 'Comprehensive Quality Assurance' and No. 43, 'Dosimetry of Interstitial Brachytherapy Sources') will be reviewed. Outline: (A) General Principles (1) QA endpoints: temporal accuracy, positional accuracy, dose delivery accuracy, and safety of the patient, personnel, and the institution (2) QA procedure ...
Power source requirements for the military were presented to provide guidelines for research and development planning. Power sources that contain a high amount of energy and are small, light and durable are a common request from military users. Safety, reliability and low temperature performance are also important factors in the selection of power sources, as are cost and energy efficiency. Issues concerning advanced batteries were reviewed with reference to high energy density cathode materials. Various thermoelectric and renewable energy materials were discussed, with reference to recovery and conversion of waste heat. It was suggested that photovoltaic devices could help revolutionize military logistics by modifying energy re-supply requirements. Solid Oxide Fuel Cells (SOFC) were considered in relation to the high price of the ceramic materials required for operation. It was noted that the development of SOFC anodes ...
The feasibility was evaluated using MCNP-DSP, an analog Monte Carlo transport cod to simulate source-driven measurements. Models of an isolated Westinghouse 17x17 PWR fuel assembly in a 1500-ppM borated water storage pool were used. In the models, the fuel burnup profile was represented using seven axial burnup zones, each with isotopics estimated by the PDQ code. Four different fuel assemblies with average burnups from fresh to 32 GWd/MTU were modeled and analyzed. Analysis of the fuel assemblies was simulated by inducing fission in the fuel using a {sup 252}Cf source adjacent to the assembly and correlating source fissions with the response of a bank of {sup 3}He detectors adjacent to the assembly opposite the source. This analysis was performed at 7 different axial positions on each of the 4 assemblies, and the source-detector cross-spectrum signature was calculated for each of ...
Lacustrine rocks are a significant component of many rift-valley sequences. Comparisons of both active and ancient rift valleys indicate that the lacustrine facies are commonly rich in organic matter and may be important sources for oil. For example, Holocene sediments in Lake Tanganyika and Cretaceous lacustrine rocks in west Africa contain as much as 12% and 20% TOC, respectively. The Newark Supergroup contains abundant lacustrine rocks. The widespread occurrence of black shales, the general similarity to known organically rich rift systems, and a few isolated geochemical analyses have caused some speculation about the potential of the Newark Supergroup to be an effective source of oil and gas. Sufficient geochemical analyses are available from lacustrine rocks in the Newark, Connecticut, and Deep River basins to evaluate their potential as hydrocarbon sources. In general, both the quantity and quality of organic matter ...
In this experiment, we measured the detection efficiency of gamma-scanning system of Irradiated Materials Examination Facility (IMEF) in Korea Atomic Energy Research Institute(KAERI) for the spent PWR fuel and activity known sources with high activity. We measured the absolute detection efficiency of gamma scanning system of IMEF to the {sup 137}Cs-source with 10.4 GBq and {sup 60}Co source with 25.9 GBq High-activity sources as standard sources, and a fuel burned in the KORI -1 reactor of the Kori Nuclear power plant. In analyzing, we used three peeks those were the 661.64 keV peak form {sup 137} Cs 1173.23 and 1332.51 keV{sup 60} Co sources, and 14 peaks of {sup 134}Cs and {sup 154}Eu on the spent fuel gamma spectrum which are in the energy range from 500 to 1,600 keV. We find second order equations for detection efficiency by using our experimental results. ...
In this experiment, we measured the detection efficiency of gamma-scanning system of Irradiated Materials Examination Facility (IMEF) in Korea Atomic Energy Research Institute(KAERI) for the spent PWR fuel and activity known sources with high activity. We measured the absolute detection efficiency of gamma scanning system of IMEF to the "1"3"7Cs-source with 10.4 GBq and "6"0Co source with 25.9 GBq High-activity sources as standard sources, and a fuel burned in the KORI -1 reactor of the Kori Nuclear power plant. In analyzing, we used three peeks those were the 661.64 keV peak form "1"3"7 Cs 1173.23 and 1332.51 keV"6"0 Co sources, and 14 peaks of "1"3"4Cs and "1"5"4Eu on the spent fuel gamma spectrum which are in the energy range from 500 to 1,600 keV. We find second order equations for detection efficiency by using our experimental results. The equation show ...
We have observed the CH_3OH J = 2-1, SiO J = 2-1, C"3"4S J = 2-1, H"1"3CO"+ J = 1-0, HN"1"3C J = 1-0, CCH N = 1-0, OCS J = 8-7, and SO J_N = 2_2-1_1 lines toward 20 massive clumps, including Midcourse Space Experiment (MSX) 8 #mu#m dark sources (infrared dark clouds) and MSX 8 #mu#m sources, by using the Nobeyama Radio Observatory 45 m telescope. We have found that the velocity widths of the CH_3OH and C"3"4S lines are broader than those of the H"1"3CO"+ line in the MSX dark sources. On the other hand, they are comparable to the velocity width of the H"1"3CO"+ line in the MSX sources. In addition, the [SiO]/[H"1"3CO"+] abundance ratio is found to be enhanced in the MSX dark sources in comparison with the MSX sources. These results suggest that shocks caused by interaction between an outflow and an ambient dense gas would have substantial impact on the chemical ...
The inner part of a fusion reactor will have to operate at very high neutron loads. In steady-state reactors the minimum fluence before the scheduled replacement of the reactor core should be at least l0-15 Mw.yr/m2. A more frequent replacement of the core is hardly compatible with economic constraints. A most recent summary of the discussions of these issues is presented in Ref. [l]. If and when times come to build a commercial fusion reactor, the availability of information on the behavior of materials and components at such fluences will become mandatory for making a final decision. This makes it necessary an early development and construction of a neutron source for fusion material and component testing. In this paper, we present information on one very attractive concept of such a source: a source based on a so called Gas Dynamic Trap. This neutron source was proposed in the ...
The GSD must be considered as a quantity by means of which the risk in a given population can be described exclusively in terms of genetic risk. In cases of a simultaneous increase in the rate of examinations, the GSD may lead to a misinterpretation of the population exposure, suggesting a decreasing trend, although there is an actual increase in the somatic radiation exposure. It is recommended to indicate not only the GSD but also the amount of somatic radiation exposure of the population for each specific source when comparing and evaluating radiation exposures from different sources. Although the somatically significant dose formally would be suited as a complement to the GSD, it is recommended to use the effective per caput dose equivalent. It must be pointed out that the application of the concept of effective dose equivalent is only appropriate for comparative evaluations of the population exposure to different ...
This report reviews Soviet R and D of (1) high-intensity negative ion sources and (2) transport and focusing of negative ion beams, using Soviet open literature of the past ten years, and correlates this data with data on Soviet institutes responsible for negative ion beam development. The Soviets are developing intense negative ion beams as the basis for creating neutral beams for injection into mirror traps and tokamaks, for inertial confinement fusion, and possibly for exoatmospheric beam weapon applications. The report focuses specifically on surface-plasma-type ion sources, which were first developed in the USSR and which show great promise for creating beams of high intensity, high brightness, and low emittance. Mechanisms for optimum negative ion beam transport are also discussed.
We present physical properties of two submillimeter selected gravitationally lensed sources, identified in the Herschel Astrophysical Terahertz Large Area Survey. These submillimeter galaxies (SMGs) have flux densities > 100 mJy at 500 um, but are not visible in existing optical imaging. We fit light profiles to each component of the lensing systems in Spitzer IRAC 3.6 and 4.5 um data and successfully disentangle the foreground lens from the background source in each case, providing important constraints on the spectral energy distributions (SEDs) of the background SMG at rest-frame optical-near-infrared wavelengths. The SED fits show that these two SMGs have high dust obscuration with Av ~4 to 5 and star formation rates of ~100 M_sun/yr. They have low gas fractions and low dynamical masses compared to 850 um selected galaxies.
A real-time orbit feedback system has been implemented at the Advanced Photon Source in order to meet the stringent orbit stability requirements. The system reduces global orbit motion below 30Hz by a factor of four to below 5{micro}m rms horizontally and 2{micro}m rms vertically. This paper focuses on dynamic orbit stability and describes the all-digital orbit feedback system that has been implemented at the APS. Implementation of the global orbit feedback system is described and its latest performance is presented. Ultimately, the system will provide local feedback at each x-ray source point using installed photon BPMs to measure x-ray beam position and angle directly. Technical challenges associated with local feedback and with dynamics of the associated corrector magnets are described. The unique diagnostic capabilities provided by the APS system are discussed with reference to their use in identifying sources of the ...
This manual was written for individuals who wish to become qualified in radiation protection as an adjunct to working with sources of ionizing radiation or using radionuclides in the field of medicine. It provides the radiation user with information needed to protect himself and others and to understand and comply with governmental and institutional regulations regarding the use of radionuclides and radiation machines. It is designed for a wide spectrum of users, including physicians, research scientists, engineers, and technicians. It should be useful also to radiation safety officers, members of radiation safety committees, and others who are responsible for the proper use of radiation sources, although they may not be working with the sources directly. The presentation in this manual is designed to obviate the need for reviews of atomic and radiation physics, and the mathematics has been limited to elementary ...
The Front End Enclosure (FEE) of the Linac Coherent Light Source (LCLS) is a shielding housing located between the electron dump area and the first experimental hutch. The upstream part of the FEE hosts the commissioning diagnostics for the FEL beam. In the downstream part of the FEE, two sets of grazing incidence mirror and several collimators are used to direct the beam to one of the experimental stations and reduce the bremsstrahlung background and the hard component of the spontaneous radiation spectrum. This paper addresses the beam loss assumptions and radiation sources entering the FEE used for the design of the FEE shielding using the Monte-Carlo code FLUKA. The beam containment system prevents abnormal levels of radiations inside the FEE and ensures that the beam remains in its intended path is also described.
Ion beams of halogens can be produced either positively or negatively charged, depending on the employed ion source. At CERN-ISOLDE, although positively charged fluorine and astatine can be obtained from a hot plasma ion source, they are often contaminated by isobars and molecular sidebands. This has generated a request from the scientific community for fluorine and astatine negative ion beams free of contaminants. The high selectivity ensured by the surface ionisation process also makes negative beams of chlorine, bromine and iodine highly attractive. However, the efficiency figures for negative surface ionisation of fluorine and astatine were lower than the ones from the hot plasma. Here we report our R and D on new surface ion sources suitable for the production of negative halogen beams.
The proposal made in this paper refers to a free electron laser FEL with small-period electromagnet undulator in SASE regime and a FEL transverse optical klystron in the amplifier regime. The relativistic electron beam source for this FEL is the 7 MeV electron linac of the National Institute for Laser, Plasma and Physics Radiation (NILPRP) in Bucharest. The paper presents the main features of the design and performance of both FELs and discusses the improvements which must be made to the accelerator in order to use it as a free electron source concerning the injection system of electrons and formation of accelerated electron beam. The findings show that this FEL can be employed as a coherent radiation source in the IR range. (author)
A new process engineering flowsheet reflecting an improved design of the LASL Bismuth Sulfate thermochemical cycle is presented. The design is based on laboratory data that indicate a lowered endothermic heat load for a partial decomposition of the solid bismuth sulfate. A small electrical energy demand should result from operation of the sulfur dioxide electrolytic step at lower acid concentration, in principle. The results of the flowsheeting analysis yield a thermal efficiency of 50% for the cycle when coupled to a conceptual fusion energy heat source at 1500/sup 0/K. A parametric analysis shows a slight drop in efficiency as the temperature of the heat source is decreased. The LASL Bismuth Sulfate thermochemical cycle appears to have potential as a means of producing hydrogen from high-temperature heat sources such as fusion, fission, and solar energy; it also appears to be competitive with alternative thermochemical ...
Measurements of neutron and gamma-ray penetrations in an iron shield were performed up to a 60-cm depth in a tightly coupled source shield configuration with the fast-neutron reactor YAYOI as a source. Rates of neutron reactions and gamma-ray dose rates in the iron shield were obtained using activation foils and thermoluminescent dosimeters. Analyses of the experiments were made by using the DOT-III code with coupled neutron and gamma-ray cross sections from ENDF/B-IV and POPOP4 libraries. To obtain the source condition for the iron shield analyses, the calculated spectrum was adjusted to the measured reaction rates at the reactor shield boundary. The calculated neutron and gamma-ray distributions in the iron shield show fairly good agreement with the experiments. The effect of difference in Bondarenko-type self-shielding factors on the analyses of the iron shield is also shown.
During the 1990's, natural gas was the energy source with the fastest rate of growth in the world energy balance. Nevertheless, recent evolutions of the energy context, in particular in terms of prices, have had a rather strong impact on the progress of the different energy sources penalizing gas a little. Beyond this competition between energies, which may increase, the medium-term perspectives of natural gas development is in keeping with an environment full of uncertainties. This article presents: the world supply and demand prospects for 2010-2015 (impact of high gas prices on other energy sources, occurrence of production constraints, political decisions of producing countries and world gas industry balance), trends on main markets (North America, Europe, Asia-Oceania), and international trade. (J.S.)
Kundur [Benincasa hispida (Thunb.) Cogn.], a member of the family Cucurbitaceae, is one of the famous crops that are grown primarily for its fruits and usually recognized with its nutritional and medicinal properties especially in Asian countries. Kundur fruit has been valued as a nutritious vegetable as it provides a good source for natural sugars, amino acids, organic acids, mineral elements and vitamins. A number of medicinal properties such as anti-diarrheal, anti-obesity, anti-ulcer, and antioxidant and diuretic have been ascribed to this fruit of high economic value. As a rich source of functionally important bioactives and therapeutics such as triterpenes, phenolics, sterols, and glycosides, the fruit has been widely used for the treatment of epilepsy, ulcer, and other nervous disor...
Background: The Internet has become a popular source of health information for patients with a variety of medical concerns; however, research examining patient interactions on the Internet has been limited. Purpose: Four questions were examined in a survey study of hysterectomy patients who visited http://www.hystersisters.com: (a) Do hysterectomy patients use the support Web site because they perceive their proximal sources of social support to be inadequate? (b) What kinds of support do patients receive from the Web site? (c) What attributes characterize the "Hystersisters" that are perceived to be most helpful? (d) How do informational sources vary depending on the nature of the patient concern? Methods: Women (N = 137) responded to questions about social support, Web site use, and perc...
PSI has a relatively long tradition in neutron imaging since the first trials were done at its formerly existing research reactor SAPHIR with film methods. This reactor source was replaced after its shutdown in 1994 by the spallation neutron source SINQ in 1996, driven by the 590MeV cyclotron for protons with presently up to 2.3mA beam current. One of the first experimental devices at SINQ was the thermal neutron imaging facility NEUTRA, which was designed from scratch and has been the first device of its kind at a spallation source. Until now, NEUTRA has been successfully in use for many investigations in a wide range of studies covering fuel cell research, environmental behavior of plants, nuclear fuel inspection and the research on cultural heritage objects. It has been the host of PhD ...
Entanglement swapping allows to establish entanglement between independent particles that never have interacted nor share a common past. This feature makes it an integral constituent of quantum repeaters and a promising tool for future tests of the foundations of quantum physics. Here, we demonstrate entanglement swapping with time-synchronized independent sources with a fidelity high enough to violate a Clauser-Horne-Shimony-Holt (CHSH) inequality by more than four standard deviations. The fact that both entangled photon pairs are created by fully independent laser sources, which are only electronically connected, ensures that this technique is suitable for future long-distance entanglement swapping and quantum-repeater experiments.
Strong gravitational lensing of an extended object is described by a mapping from source to image coordinates that is nonlinear and cannot generally be inverted analytically. Determining the structure of the source intensity distribution also requires a description of the blurring effect due to a point spread function. This initial study uses an iterative gravitational lens modeling scheme based on the semilinear method to determine the linear parameters (source intensity profile) of a strongly lensed system. Our 'matrix-free' approach avoids construction of the lens and blurring operators while retaining the least squares formulation of the problem. The parameters of an analytical lens model are found through nonlinear optimization by an advanced genetic algorithm (GA) and particle swarm optimizer (PSO). These global optimization routines are designed to explore the parameter space thoroughly, mapping model degeneracies in ...
Orbit correction is now routinely performed at the few-micron level in the Advanced Photon Source (APS) storage ring. Three diagnostics are presently in use to measure and control both AC and DC orbit motions: broad-band turn-by-turn rf beam position monitors (BPMs), narrow-band switched heterodyne receivers, and photoemission-style x-ray beam position monitors. Each type of diagnostic has its own set of systematic error effects that place limits on the ultimate pointing stability of x-ray beams supplied to users at the APS. Limiting sources of beam motion at present are magnet power supply noise, girder vibration, and thermal timescale vacuum chamber and girder motion. This paper will investigate the present limitations on orbit correction, and will delve into the upgrades necessary to achieve true sub-micron beam stability.
An apparatus for non-invasively inspecting an object, such as an item of luggage, for explosives material is described. It comprises a multi-channel thermal neutron inspection system having a plurality of neutron irradiation chambers. Simultaneous operation of several channels increases the maximum system throughput several times. Each chamber has a lithium neutron source which is stimulated to neutron production by a proton beam. Beam switching magnets are energised by pulsing to divert a common proton beam to each source in turn. The initial beam is generated by a radio frequency quadrupole accelerator. The advantages of this system are very low residual source activity and controllable neutron production thereby minimising safety hazards. The irradiation chamber may contain several different gamma ray detectors to identify the elements present in explosives material. In addition, a neutron radiography imaging means may ...
Objective:EEG source imaging provides important information regarding the underlying neural activity from noninvasive electrophysiological measurements. The aim of the present study was to evaluate source reconstruction techniques by means of the intracranial electrocorticograms (ECoGs) and functional MRI.Methods:Five source imaging algorithms, including the minimum norm least square (MNLS), LORETA with Lp-norm (p equal to 1, 1.5 and 2), sLORETA, the minimum Lp-norm (p equal to 1 and 1.5; when p=2, the MNLS method is mathematically equivalent to the minimum Lp-norm) and L1-norm (the linear programming) methods, were evaluated in a group of 10 human subjects, in a paradigm with somatosensory stimulation. Cortical current density (CCD) distributions were estimated from the scalp somatosensor...
The development and occurrence of new electron accelerators and applications are according to the human society development law, as a whole. The period of economic standstill is generating an intense creative activity in the domain of science and engineering which also resulting in great achievements in the field of electron accelerators. This paper presents the basic principle of the electron beam applications and the accelerators required characteristics for their present and potential applications in the domains: radiation sources, diagnostics, radiation processing, energetics, environment, defense and basic sciences. All these are correlated to the new generation of accelerators which, for the acceleration process, may employ electromagnetic fields generated by standard sources, atomic lasers, free electron lasers, Cerenkov effect, Smith - Purcell effect, electron beams, plasma, excited atoms into a crystal or other ...
With the combination of source ventilation and ceiling cooling for air-conditioning of working and recreation rooms, a ventilation system is available which fulfills the highest demands regarding thermal comfort. In order to utilize the advantages of this ventilation system with regard to air quality and thermal comfort to an optimum, the influence of the radiation exchange between cooling ceiling and walls on the flow in the room is investigated experimentally. Energy transfer from the walls to the cooled ceiling may result in an insufficient temperature of the walls compared to ambient air and in an upward flow on the wall surfaces (downward flow of) driven by gravity, which influences the flow pattern in the case of source ventilation. (orig.)
The report identifies and analyzes the economic impacts of water pollution control regulations on the battery manufacturing industry. These regulations include effluent limitations and standards based on BPT (best practical control technology currently available), BAT (best available technology economically achievable), PSES (pretreatment standards existing sources), NSPS (new source performance standards), and PSNS (pretreatment standards new sources), that have been promulgated under authority of Sections 301, 304, 306, 307, 308, and 501 of the Federal Water Pollution Control Act, as Amended (the Clean Water Act). The primary economic impact variables of interest include price changes, plant closures, substitution effects, changes in employment, shifts in the balance of foreign trade, changes in industry profitability, structure, and competition, and impacts on small business.
To investigate the 2D/1D fusion core analysis method, a 1D neutron transport problem solver, PEACH-ID, is developed. It is a code of method of characteristics (MOC), both the usual fiat-source step characteristics (SC) scheme and linear source (LS) approximation scheme are adopted for tracking calculation along the neutron flying trajectory. Exponential function interpolation table and fission source extrapolation are adopted as two major methods to accelerate the computational process. Numerical results demonstrate that PEACH-1D is accurate and efficient, and the proposed LS scheme is able to handle quite larger mesh division and deserves much more application in the MOC codes. (authors)
The coupled neutron-gamma cross section libraries BUGLE-80 and SAILOR are compared, with focus on gamma production and transport and its sensitivity to the thermal component of the neutron flux. In addition, the importance of the prompt versus delayed components of the gamma source is addressed. Although BUGLE-80 shows some discrepancies in the core region, the two libraries demonstrate similar capability in the vicinity of the pressure vessel and beyond. The delayed fission product gammas from the core have little impact on the local gamma fluxes beyond the pressure vessel. Although thermal neutron capture is the dominant component of the gamma source, there is little sensitivity of the gamma source to uncertainties in the thermal neutron cross sections, due to compensating effects which tend to keep the thermal neutron capture rate relatively constant.
The emittances of hydrogen and deuterium negative ion beams produced by volume ion sources have been measured in a transverse plane normal to the beam trajectory. The extraction voltage was varied from 10 to 40 kV, and the transverse magnetic field in the Penning discharges was varied from 0.1 to 0.2 T. Measurements were made on beams with current densities up to 60 mA/cm/sup 2/ at Oak Ridge National Laboratory with an emittance scanner originally developed at Los Alamos National Laboratory. The beam profile at the scanner can be used to improve the accuracy of the emittance measurements. Other factors affecting emittance measurements are discussed. This analysis may be applicable to other ion sources. 6 figs.
This chapter consists of some points including an introduction, the basic parts of mass spectroscope device, sample introduction into the inductively coupled plasma, pneumatic nebuliser, ultrasonic nebuliser, dry gas cloud system, laser ablation unit, inductively coupled plasma-ion source, extraction of ions from ion source, mass analysis, quad-polar mass spectrometer, dual assembly mass spectrometer, mass spectrometer by calculation of time of flight, ion interferences and the ability of resolution, ion counter, working conditions of inductively coupled plasma mass spectroscope device, efficiency of ion transportation in an inductively coupled plasma mass spectroscope device and applications of analysis using mass spectroscope of induced plasma including nuclear, industrial, geological, environmental and archaeological applications, measurement of isotopes ratio and applications in tracing crimes.
The /sup 252/Cf-source-driven noise analysis method determines the subcriticality of a system containing fissionable material from the ratio of cross power spectral densities between the detectors that detect particles from the fission process and between these detectors and an ionization chamber containing a spontaneously fissioning neutron source which provides neutrons to induce fission in the system. This method has two advantages: (1) a calibration is not required and thus subcriticality can be determined from measurements only on the subcritical system of interest, and (2) the subcriticality is independent of the type of detector or its efficiency. These properties of this technique are illustrated by measurements.
The problem of passively tracking a moving signal source has importance in a variety of applications such as radar, sonar, seismology, and radio astronomy. In many applications, only limited information is available about the signal source. It will be assumed here that only the signals which are detected by the sensors and the velocity of the source signal are known. The objective of this document is to present a program which passively tracks a target using an array of sensors. This program is available in MATLAB, version 3.5. The algorithm which is implemented consists of three main parts: time delay estimation, passive localization, and data post processing. Each of these parts are discussed, and the mathematical foundation for their solution given. Following, this the organization of the program is presented, and an example of its usage is given.
An analytical method was proposed for calculating radiative fluxes incident on a planar circular detector from a volume multiple point chemi- or bio-luminescent source inside a coaxial cylindrical reactor. The method was designed for a cylindrical reactor when the surface reflections were neglected and when chemi- or bio-luminescence reaches a detector embedded in the same homogeneous optical medium as the point emitters of the volume multiple point source model. The radiative fluxes from arbitrarily distributed point emitters were expressed by one generalized quadruple-integral formula. Then some double- and single-integral formulas were obtained for calculating radiative fluxes from identically radiating point emitters uniformly distributed within the reactor. Selected results were compu...
This work addresses the problem of estimating the direction-of-arrival (DOA) of two sources using an array of sensors. This problem is mostly useful in radar applications, where we have few targets at each range bin. Super-resolution algorithms, such as maximum likelihood (ML) estimation and multiple signal classification (MUSIC), have been applied to this problem, but the former involves high computation efforts, while the later has poor estimation performance for coherent sources. In this work, we propose a DOA estimation network, named RBF-AML, which combines the approximated ML (AML) estimator and a radial basis function (RBF) neural network (NN). In the proposed RBF-AML network, the entire two dimensional DOA space is divided into multiple sectors covered by RBF experts. The AML funct...
Suppose an astronomer is equipped with a device capable of detecting emissions -- whether they be electromagnetic, gravitational, or neutrino -- from transient sources distributed throughout the cosmos. Because of source rate density evolution and variation of cosmological volume elements, the sources first detected when the machine is switched on are likely to be ones in the high-redshift universe; as observation time increases, rarer, more local, events will be found. We characterize the observer's evolving record of events in terms of a "probability event horizon", converging on the observer from great distances at enormous speed, and illustrate it by simulating neutron star birth events distributed throughout the cosmos. As an initial application of the concept, we determine the approach of this horizon for gamma-ray bursts (GRBs) by fitting to redshift data. The event rates required to fit the model are consistent with ...
Experiments with fresh PWR fuel assemblies were performed to assess the {sup 252}Cf-source-driven frequency analysis method for measuring the subcriticality of spent fuel. The measurements at the Babcox and Wilcox Critical Experiments Facility mocked up between 17x17 fuel pins (single assembly) and a full array of 4961 fuel pins (about 17 fuel assemblies) in borated water with a fixed B concentration. For the full array, the B content of the water was varied from 1511 at delayed criticality to 4303 ppM. Measurements were done for various source-detector-fuel pin configurations; they showed high sensitivity of frequency analysis parameters to B content and fissile mass. Parameters such as auto and cross power spectral densities can be calculated directly by a more general model of the Monte Carlo code (MCNP-DSP). Calculation-measurement comparisons are presented. This model permits the validation of neutron and gamma ray transport calculational ...
Coupled rat heart mitochondria produce externally hydrogen peroxide at the rates which correspond to about 0.8 and 0.3 per cent of the total oxygen consumption at State 4 with succinate and...Full Text Available
OBJECTIVE: To use Medicaid claims data to construct patient origin-based market areas for dental services and compare constructed market areas with those based on the practice county. DATA SOURCES:...Full Text Available
Strain F, a recently isolated ruminal bacterium, grew rapidly with glutamate or glutamine as an energy source in the presence but not the absence of Na. Monensin, a Na+/H+ antiporter, completely inhibited...Full Text Available
OBJECTIVE. This study examines variations in the efficient use of hospital resources across individual physicians. DATA SOURCES AND SETTING. The study is conducted over a two-year period (1989-1990)...Full Text Available
The purpose of this study was to examine relationships between weather and outdoor physical activity (PA). An online weather source was used to obtain daily max temperature [DMT], precipitation, and...Full Text Available
Y{sub 2-x}Tb{sub x}SiO{sub 5} and Y{sub 2-x}Eu{sub x}SiO{sub 5} nanophosphors with seven different kinds of silicate sources were synthesized by sol-gel method. The structures have been investigated to be composed of nanometer-size grains of 30-60 nm through X-ray diffraction (XRD) and scanning electron microscopy (SEM) was used to compare the different morphology of patterns from seven different silicon sources. The photoluminescence of Y{sub 2-x}Tb{sub x}SiO{sub 5} was investigated as a function of silicate sources and the results revealed that these nanometer materials showed the characteristic emission {sup 5}D{sub 4} {yields} {sup 7}F{sub J} (J 6, 5, 4, 3) of Tb ions. The characteristic emission {sup 5}D{sub 0} {yields} {sup 7}F{sub J} (J = 1, 2, 4) of Eu ions was also found in the materials of Y{sub 2-x}Eu{sub x}SiO{sub 5}.
This paper describes recent measurements of the subcritical neutron multiplication factor using the /sup 252/Cf source-driven neutron noise analysis method. This work was supported by a program of collaboration between the United States Department of Energy and the Power Reactor and Nuclear Fuel Development Corporation of Japan related to the development of fast breeder technology. The experiment reported consists of a configuration of two interacting tanks of uranyl nitrate aqueous solution with different uranium concentrations in each tank. The /sup 252/Cf-source-driven neutron noise analysis method obtains the subcriticality from the signals of three detectors: the first, a parallel plate ionization chamber with /sup 252/Cf electroplated on one of its plates that is located in or near the system containing the fissile material, and produces an electrical pulse for every spontaneous fission that occurs and thereby serves as a timed ...
The pollutants from the exhausts of internal combustion engines cause a range of illnesses and are the main source of atmospheric contamination. This article explores the options for curbing pollution in the UK including catalytic converters, electric cars, and natural gas cars. It is likely that the onus will remain with the car manufacturers for developing solutions. (UK)
This paper discussed issues related to the storage of electricity produced from renewable energy sources. Storage systems currently used by distribution systems were reviewed. The study showed that successful storage systems ensure high charging and discharging rates for shorter periods of time. Systems with high storage capacities must also be able to store energy for longer periods of time than traditional energy storage systems. Systems include pumped storage plants; electro-chemical accumulators; compressed air accumulators; and redox flow batteries. Hydrogen technologies for the storage of electric energy from renewable sources were reviewed. The paper also outlined energy storage and fuel cell research currently being conducted by researchers in the Czech Republic. The study concluded by stating that new energy storage technologies are required to ensure the reliability of electricity produced from renewable energy ...
Beta silicon carbide is an excellent candidate semiconductor material for demanding applications in high power and high temperature electronic devices due to its high breakdown voltage, relatively large band gap, high thermal conductivity and high melting...
The e.p.r. spectra of the Fe-proteins of nitrogenase from all sources studied have unusual features in that they have very anisotropic linewidths and low integrated intensities. These characteristics...Full Text Available
The most publicly justifiable application of human cloning, if there is one at all, is to provide self-compatible cells or tissues for medical use, especially transplantation. Some have argued that...Full Text Available
The planned spallation source can be of considerable significance for biomedical basic research and for clinically relevant diagnostic and therapeutic applications. The following gives a brief description and explanations for its possible use in clinical medicine: I. Treatment of Malignant Tumors II. Production of Isotopes for Biochemical Investigations in Living Organisms for Diagnostic Purposes.
This document is a collection of spreadsheets detailing in a county by county manner the agricultural crop, agricultural wastes, municipal wastes, and industrial wastes of South Carolina that are potential biomass energy sources.
This document is a collection of spreadsheets detailing in a county by county manner the agricultural crop, agricultural wastes, municipal wastes and industrial wastes of North Carolina that are potential biomass energy sources.
Computer-aided diagnosis of neural diseases from EEG signals (or other physiological signals that can be treated as time series, e.g., MEG) is an emerging field that has gained much attention in past...Full Text Available
... based, disease treatment remains promising, the emphasis for stem cell research from the biomedical research community is clear, and ... diagnosis as a novel source of embryos for stem cell research. Repr...
Sep 28, 2011 ... Source: Flagstaff, AZ: Northern Arizona University. 87 p. Thesis. Description: High severity wildfires have been increasing across southwestern ...
Various energy sources and motors of divers types can be used in electric cars with operating modes subjected to a number of particular constraints. As a result, the possible structures of the converters, that are analysed in detail, are about a dozen in number. Also considered is the use of solid-state components - thyristors, power transistors and new components.
... being reported (Kisseberth et al., 1984; Ma, 1989; Shore and Douben, 1994). Small mammals are useful indicator species because they have relatively small home ranges allowing a direct tie to the source of ...
The genus of filamentous cyanobacteria, Lyngbya, has been found to be a rich source of bioactive metabolites. However, identification of such compounds from Lyngbya...Full Text Available
We present photoelectric BVRI photometry for 16 T Tau and related stars in the Rho Oph dark cloud, as well as vidicon spectroscopic observations for nine stars. The color excesses of these stars favor circumstellar dust shells as the source of the observed infrared excesses.
This report focuses on air quality at the Nevada Test Site (NTS) for 1994. A general description of the effluent sources are presented. Each potential source of NTS emissions was characterized by one of the following: (1) by monitoring methods and procedures previously developed at NTS; (2) by a yearly radionuclide inventory of the source, assuming that volatile radionuclides are released to the environment; (3) by the measurement of tritiated water concentration in liquid effluents discharged to containment ponds and assuming all the effluent evaporates over the course of the year to become an air emission; or (4) by using a combination of environmental measurements and CAP88-PC to calculate emissions. Appendices A through J describe the methods used to determine the emissions from the sources. These National Emission Standards for Hazardous Air Pollutants (NESHAP) emissions are very conservative, are ...
Klebsiella oxytoca can use nitrate and nitrite as sole nitrogen sources. The enzymes required for nitrate and nitrite assimilation are encoded by the nasFEDCBA operon....Full Text Available
considers a wide range of pathways to advance the nation's current capabilities. The present ... opment of new energy sources, aging infrastruc- ture and ... and manufacturing TA strategic roadmap as brief- ..... pellant storage and transport. ...
Aluminium (Al) toxicity, affecting around half of the world¿s arable land, severely hinders the ability of crop plants to utilize moisture and nutrients by restricting root growth and function. Among the cultivated cereals, rye is the most Al-tolerant and represents an important potential source of ...
Methylosulfonomonas methylovora M2 is an unusual gram-negative methylotrophic bacterium that can grow on methanesulfonic acid (MSA) as the sole source of carbon and energy. Oxidation...Full Text Available
OBJECTIVE. This study was conducted to determine whether an index for measuring quality of care for psychiatric emergencies is reliable and valid. DATA SOURCES/STUDY SETTING. The study used primary...Full Text Available
We construct a sample of low-redshift Ly-alpha emission-line selected sources from GALEX grism spectroscopy of nine deep fields to study the role of Ly-alpha emission in galaxy populations with cosmic time. Our final sample consists of 122 (142) sources selected in the redshift interval z=0.195-0.44 (z=0.65-1.25) from the FUV (NUV) channel. We classify the Ly-alpha sources as AGNs if high-ionization emission lines are present in their UV spectra and as galaxies otherwise. These classifications are broadly supported by comparisons with X-ray and optical spectroscopic observations. We classify additional sources as AGNs using line widths for our Ly-alpha emitter (LAE) analysis. Defining the GALEX LAE sample in the same way as high-redshift LAE samples, we show that LAEs constitute only about 5% of NUV-continuum selected galaxies at z~0.3. We also show that they are less common at z~0.3 than they are at ...
Summary: The small DNA tumor viruses have provided a very long-lived source of insights into many aspects of the life cycle of eukaryotic cells. In recent years, the emphasis has been on cancer-related...Full Text Available
New developments in fluorophores as well as in detection methods have fueled the rapid growth of optical imaging in the life sciences. Commercial widefield microscopes generally use arc lamps, excitation/emission...Full Text Available
A short survey of the energy situation in Iran is given with the aid of some interesting figures. Following remarks on the national and international energy policy, the developments regarding individual energy sources and electricity production are described.
Large population sizes, rapid growth and 3.8 billion years of evolution firmly establish microorganisms as a major source of the planet's biological and genetic diversity. However, up to 99% of the...Full Text Available
Characteristics of inertia gravity waves associated with convection are investigated in the lower stratosphere using high-resolution radiosonde data observed from 18 June to 15 July of 2005 and 2007 in Korea. Three-dimensional ray-tracing model and reanalysis data are used to investigate the propagation and the sources of the observed waves. The observed waves associated with convections are discriminated based on the existence of convections when and where the rays reach the average height range of convective clouds. Waves observed in 2005 and 2007 show similar spectral characteristics, but wave energy in 2007 is significantly larger than in 2005. The observed waves propagate from three source regions: the northeastern, southeastern, and western regions around Korea. They show preferential propagation directions based on their sources, and convections from the western region generate larger-amplitude gravity waves than the ...
Water samples from several ponds in Minnesota were evaluated for their capacity to induce malformations in embryos of Xenopus laevis. The FETAX assay was used to assess the occurrence of malformations...Full Text Available
Reichert's membrane, an extraembryonic membrane present in developing rodents, has been proposed as an in vivo model for the study of basement membranes. We have used this membrane as a source for isolation...Full Text Available
Gamma-ray burst (GRB) is one of the candidates of high-energy cosmic-ray acceleration sites. They may be also ultra-high-energy (above 3 EeV) cosmic-ray (UHECR) sources. In this paper, we discuss possibilities and implications of high-energy cosmic-ray acceleration in GRBs. (1) First, we show that not only protons but also heavier nuclei can be accelerated up to ultra-high energies in both usual high-luminosity (HL) and low-luminosity (LL) GRBs by using the Geant4. LL GRBs may also make a significant contribution to the observed UHECR flux if they form a distinct population, and we investigate cosmic-ray acceleration in LL GRBs in detail. (2) Second, we discuss implications of the GRB-UHECR hypothesis (and Hypernova-UHECR hypothesis) to cosmic-ray astronomy. HL GRBs and LL GRBs will lead to different source number densities as UHECR sources, so that the determination of the number density of UHECR ...
Growth of Lactococcus lactis subsp. lactis biovar diacetylactis was observed on media with citrate as the only energy source. At pH 5.6, steady state was achieved in...Full Text Available
The sensitive explosives used in initiating devices like primers and detonators are called primary explosives. Successful detonations of secondary explosives are accomplished by suitable sources of...Full Text Available
Differential phase-contrast X-ray imaging has been performed in a Talbot-Lau configuration, where a multiline X-ray source was used instead of a combination of a hard-X-ray multiple slit and a normal focus X-ray generator. When the multiple slit is used, a high aspect ratio structure is needed and slit width should be below 10 ?m for its function. The fabrication and use of such a multislit can be omitted using the presented configuration. The multiline X-ray source was developed by making grooves on a tungsten rotating anode, which was irradiated by an electron beam to generate X-rays. An array of 10?m line sources with a pitch of 30?m was formed and combined with a 4.5 ?m pitch phase grating and a 5.3 ?m pitch amplitude grating to generate differential phase contrast. With a total exposure time of 40 s, a differential phase image depicting cartilages was obtained. (author)
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.
Francisella tularensis requires iron (Fe) for growth, but the biologic sources of Fe for this organism are largely unknown. We found that Francisella sp. growing in...Full Text Available
A prototype detector based on the inclined boron layer principle is introduced. For typical measurement conditions at the Liquids Reflectometer at the Spallation Neutron Source, its count rate capability is shown to be superior to that of the current detector by nearly two orders of magnitude.
A prototype detector based on the inclined absorber layer principle is introduced. For the Liquids Reflectometer at the Spallation Neutron Source, it is shown to be a significant improvement over its current detector, which imposes an instantaneous count rate limitation of 50 kcps.
The report summarizes the environmental significance of the priority pollutants being discharged from thirteen subcategories of the ore mining and dressing point source category. In addition, the impact of proposed effluent limitations guidelines is assessed from an environmental perspective.
The report discusses the capabilities of equipment vendors to supply and install the quantity of flue gas desulfurization systems required to meet alternative standards for coal-fired steam generators. It analyzes limiting factors affecting supply capabilities (such as the availa...
The Calorie (kcal) of present U.S. food labels is similar to the original French definition of 1825. The original published source (now available on the internet) defined the Calorie as the quantity...Full Text Available
This document is a technical background document for proposed regulations to limit effluent discharges to waters of the United States and introductions of pollutants into publicly owned treatment works from facilities engaged in porcelain enameling. The p...
This paper hopes to share the insights we experienced during designing, building, and running an indexing solution for a large set of radiological reports and images in a production environment for...Full Text Available
Drawing on published tobacco document research and related sources, this article applies Farnsworth and Holden's conceptual framework for the analysis of corporate power and corporate involvement...Full Text Available
The influence of location of airborne particle source, ventilation rate, air inlet size, supply air velocity, air outlet location, and heat source on the distributions of airborne particle concentration and draught risk in an operating room is investigated. The investigation is carried out by using a flow program with the k-[epsilon] model of turbulence. Based on a standard case, five cases, each with one changed parameter, are computed, and the detailed field distributions of air velocity, temperature, airborne particle concentration, and draught risk are presented. The parametric study concludes that, for a better air quality and thermal comfort, it is desirable to use a higher inflow rate, a larger inlet area, and a uniform velocity profile of supply air. Outlet location and heat source have little influence on the distributions of the particle concentration in the room. It has also been found that the distributions of ...
I present here a review of past and present multi-disciplinary research of the Pittsburgh Computational AstroStatistics (PiCA) group. This group is dedicated to developing fast and efficient statistical algorithms for analysing huge astronomical data sources. I begin with a short review of multi-resolutional kd-trees which are the building blocks for many of our algorithms. For example, quick range queries and fast n-point correlation functions. I will present new results from the use of Mixture Models (Connolly et al. 2000) in density estimation of multi-color data from the Sloan Digital Sky Survey (SDSS). Specifically, the selection of quasars and the automated identification of X-ray sources. I will also present a brief overview of the False Discovery Rate (FDR) procedure (Miller et al. 2001a) and show how it has been used in the detection of ``Baryon Wiggles'' in the local galaxy power spectrum and source identification ...
Shilajit has been used traditionally in folk medicine for treatment of a variety of disorders, including syndromes involving excessive complement activation. Extracts of Shilajit contain significant...Full Text Available
Massive particle candidates for dark matter provide a potentially observable signature by virtue of their annihilations in the galactic halo at a known but model-dependent rate. Possible signatures are described, including cosmic ray antiproton and gamma-ray production. (orig.).
Klebsiella pneumoniae is able to grow anaerobically with citrate as a sole carbon and energy source by a fermentative pathway involving the Na+-dependent citrate...Full Text Available
This technical report describes an outline, features, total energy efficiency, and specifications of binary heat pump system. A closed circuit distributed water heat source heat pump method is employed in the binary heat pump system. Since the circulating water, which is adjusted at a constant temperature, is used as the heat source of the indoor unit, a stable performance can be obtained regardless of outside atmospheric temperature. The binary heat pump system is mainly composed of a center heat pump unit, indoor heat pump unit, heat source water pipes, and circulating pump. The center heat pump unit and the indoor heat pump unit are connected with each other by the heat source water, and each unit can be operated independently. This system is characterized by the simultaneous operation of cooling and heating, high efficiency, high energy saving, high reliability of system, excellent environmental ...
Atmospheric electrodynamics research is summarized, focusing on three general areas: the ionosphere as a source for middle atmospheric electrodynamics, regional and global scale electrodynamics, and thunderstorms and lightning. New or improved instrumentation techniques which have furthered atmospheric electrodynamics research are also discussed. 93 refs.
The different radiation loads caused by natural and artificial radionuclides are compared in this paper. This examples will serve to illustrate that the problem of population exposure to radiation can only be solved in consideration of all components and to show which effects of the radiation from natural sources are of special importance in this connexion. (orig./AK).
The lift and drag characteristics of a wide range of bluff body shapes were studied using data from sources including wind tunnel testing and flow visualization. For a given orientation of any body, it is found that its drag is strongly influenced by its ...
The TRIGA-SPEC experiment has been installed recently at the research reactor TRIGA Mainz. Ground state properties like masses, charge radii, spins, and moments of short-lived nuclides can be determined with very-high precision using the Penning trap mass spectrometer TRIGA-TRAP, and the collinear laser spectroscopy setup TRIGA-LASER. Short-lived neutron-rich radionuclides in the mass range 80 < A < 140 are produced by thermal neutron induced fission of e.g. U-235, Pu-239 or Cf-249, respectively. For the extraction and ionization of the fission products a gas-jet system is coupled to a 2.45-GHz ECR ion source for the production of singly charged ions. The gas-jet has been tested on-line and fission products have been extracted. First off-line tests of the ion source have been performed successfully with argon gas. The results of the commissioning test of the ion source and the on-line coupling of the experiments are ...
Several widely recognized sources of nomenclature regarding the bovine external digit were reviewed, compared, and utilized in a clinical survey of bovine digital disease. During this process, some...Full Text Available
Recent X-ray and radio observations have identified a transient low-mass X-ray binary (LMXB) located only 0.1 pc in projection from the Galactic center, CXOGC J174540.0-290031. In this paper, we report the detailed analysis of X-ray and infrared observations of the transient and its surroundings. Chandra bservations detect the source at a flux of F_X = 2e-12 erg cm^-2 s^-1 (2-8 keV). After accounting for absorption both in the interstellar medium and in material local to the source, the implied luminosity of the source is only L_X = 4e34 erg/s (2-8 keV; D=8 kpc). However, the diffuse X-ray emission near the source also brightened by a factor of 2. The enhanced diffuse X-ray emission lies on top of a known ridge of dust and ionized gas that is visible infrared images. We interpret the X-ray emission as scattered flux from the outburst, and determine that the peak luminosity of CXOGC J174540.0-290031 was ...
ADVANCED MODELING, S IMULATION, AND ANALYSIS (ROADMAP 14). ...... Metal/Silicon Extraction from Regolith & manufacturing ..... addresses solar power, energy storage (in conjunction with solar power and as a prime source of ...
The /sup 252/Cf-source-driven neutron noise analysis method for obtaining the subcriticality of an assembly of fissile material from cross-power spectral densities (CPSDs) was developed to avoid some difficulties inherent in other measurement methods. This method requires measurement of frequency-dependent CPSD between a pair of detectors in or near the fissile assembly and CPSDs between these detectors and a source of correlated neutron noise from an ionization chamber containing /sup 252/Cf, also in or near the fissile assembly. Also, the auto-power spectral density of the source is required. The ratio of spectral densities is then formed and is related to the subcriticality. To date various measurements have been performed which demonstrate the usefulness of the method including measurements with single uranium metal cylinders. The experiments described here, which used coupled uranium (93.15 wt % /sup 235/U) metal ...