Energy Technology Data Exchange (ETDEWEB)

FT-IR spectroscopic studies of the adsorption of natural and {sup 18}O-enriched NO gases on thermally and cleaned MgO powders were carried out. The temperature dependence of the IR spectra was investigated to characterize the adsorbate species. Three types [1, 2, and 3] of NO adsorptions were obtained in the wavenumber region of 1500--1000 cm{sup {minus}1}. Those types were examined using density functional theory [(U)B3-LYP/6-31G*] vibrational analyses of (MgO){sub n}-NO cluster calculations. Types 1, 2, and 3 were assigned to monodentate, asymmetric, and symmetric bidentate geometries, respectively. A type 4, a tridentate model which involves a NO{sub 3}-like species, was calculated and was found to give wavenumbers of less than 1,000 cm{sup {minus}1}. The splitting of IR bands of type 3 due to the {sup 15}N{sup 18}O adsorbate was ascribed to the oxygen ...

International Nuclear Information System (INIS)

... dwba excitation functions nitrogen 15 oxygen 16 beams oxygen 16 reactions

Energy Technology Data Exchange (ETDEWEB)

This report discusses the following topics: Fusion-fission in light nuclear systems; High-resolution Q-value measurement for the {sup 24}Mg+{sup 24}Mg reaction; Heavy-ion reactions and limits to fusion; and Hybrid MWPC-Bragg curve detector development.

Energy Technology Data Exchange (ETDEWEB)

The synthesis of (3-{sup 15}N)-labeled adenine has been reported by several groups. Each of these syntheses followed essentially the same route, in which the {sup 15}N is introduced by nitration of 4-bromoimidazole under forcing conditions using ({sup 15}N)-HNO{sub 3}. The authors have devised an alternate route which uses an azo coupling reaction for introduction of the {sup 15}N and proceeds through the intermediacy of (5-{sup 15}N)-labeled 5-aminoimidazole-4-carboxamide (AICA). An unrelated route to the (5-{sup 15}N)-labeled 5-amino-imidazole ribonucleoside (AIRs) was recently reported. AICA is a versatile precursor, which is most commonly used for entry into the guanine or isoguanine families, although it is usually used as the ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

The economic attractiveness and negative environmental impact of nitrogen (N) fertilization in pastures depend on the N use efficiency in the soil-plant system. However, the recovery of urea-{sup 15}N by Panicum maximum cv. Tanzania pastures, one of the most widely used forage species in intensified pastoral systems, is still unknown. This experiment was conducted in a randomized complete block design with four treatments (0, 40, 80 and 120 kg ha-1 of N-urea) and three replications, to determine the recovery of {sup 15}N urea by Tanzania grass. Forage production, total N content and N yield were not affected by fertilization (p > 0.05), reflecting the high losses of applied N under the experimental conditions. The recovery of {sup 15}N urea (% of applied N) in forage and roots was not affected by fertilization levels (p > 0.05), but decreased ...

Energy Technology Data Exchange (ETDEWEB)

An improved method for the synthesis of (/sup 15/N) 16-Doxyl stearate, a fatty-acid spin label, is reported. The method requires only one mole of (/sup 15/N) 2-amino-2-methyl propanol per mole of methyl keto stearate with an overall yield of about 50%. In contrast, the previous method produced only 1-3% yield. The great improvement in yield was achieved mainly through the reduction of reaction volume which increases the reaction rate by the law of mass action.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

Attention was focused on the fission process in light nuclear systems. A model calculation based on the transition-state model of nuclear fission was applied to [sup 47]V fission as populated through multiple entrance channels and to fusion-fission cross sections for production of [sup 28]Al through three different entrance channels. Angular distributions are shown for different mass channels of the [sup 29]Si+[sup 27]Al reaction at E[sub lab] = 125 MeV. Pronounced structure is seen in the symmetric and near-symmetric fission channels from the [sup 24]Mg+[sup 24]Mg reaction; cross sections for binary fragment emission are shown for E[sub lab] = 90 MeV. A large Bragg-curve detector was used in this experiment. Ways to optimize detector response were studied; in addition, the Bragg detector was instrumented with an internal position-sensitive multiwire proportional counter.

International Nuclear Information System (INIS)

Red mud is a kind of alumina production, characterized by high content of fine-dispersion Fe, Al and Ti oxyhydrates; it is studied from the viewpoint of its application as a sorbent for Sr. The red mud specific surface constitutes 23-25 m"2/g, the density is of 3.3-3.4 g/cm"3 and the melting temperature is 1350-1370 deg C. It is established that the maximum sorption capacity of the red mud for strontium equals 420 #+-# 24 mg-eq/100 g. The red mud high sorption properties make it possible to recommend it as a sorbent by constructing technogenic barriers at the radioactive wastes disposal sites

Energy Technology Data Exchange (ETDEWEB)

Using discrete air sampling, values of {delta}{sup 13}C and {delta}{sup 18}O in atmospheric CO{sub 2}, as well as its concentration, were measured in a forest in the central part of the main island of Japan during the period from June 1994 to June 1996 to examine the biospheric contribution to their temporal variations. {delta}{sup 13}C shows a prominent diurnal variation with high values in the daytime and low values in the nighttime, especially during the warm season. {delta}{sup 13}C also vary seasonally, showing a maximum in summer and a minimum in spring. The diurnal and seasonal variations of {delta}{sup 13}C are opposite in phase with those of the CO{sub 2} concentration. The rate of change in {delta}{sup 13}C with respect to the CO{sub 2} concentration is found to be approximately -0.005 per mille/ppmv. This suggests that the diurnal and seasonal variations of the CO{sub 2} concentration are produced primarily by diurnally- and ...

Energy Technology Data Exchange (ETDEWEB)

The rate of the oxygen-exchange reaction in an aqueous solution of a heterocyclic oxygen compound, 2,4,6-trimethylpyrylium perchlorate, was quantitated. The /sup 18/O isotope effect in /sup 13/C NMR spectroscopy affords a direct, continuous, and relatively simple analysis of the reaction and was used to obtain data on the incorporation of /sup 18/O from solvent H/sub 2//sup 18/O into the pyrylium salt. Due to the low solubility of this salt in aqueous solutions, 2,4,6-trimethyl(2-/sup 13/C)pyrylium perchlorate and 2,4,6-trimethyl(2,6-/sup 13/C/sub 2/)pyrylium perchlorate were synthesized to facilitate the acquisition of the data on an NTC-200 spectrometer operating at 50.31 MHz. Upon incorporation of /sup 18/O into the pyrylium salt, the /sup 13/C NMR signal of the directly bonded carbon atom is shifted upfield 0.038 ...

International Nuclear Information System (INIS)

We performed density functional calculations to examine the effects of solvation, hydrogen bonding, backbone conformation, and the side chain on 15N chemical shielding in proteins. We used N-methylacetamide (NMA) and N-formyl-alanyl-X (with X being one of the 19 naturally occurring amino acids excluding proline) as model systems. In addition, calculations were performed for selected fragments from protein GB3. The conducting polarizable continuum model was employed to include the effect of solvent in the density functional calculations. Our calculations for NMA show that the augmentation of the polarizable continuum model with the explicit water molecules in the first solvation shell has a significant influence on isotropic 15N chemical shift but not as much on the chemical shift anisotropy. The difference in the isotropic chemical shift between the standard ?-sheet and ?-helical conformations ranges ...

Energy Technology Data Exchange (ETDEWEB)

To understand more fully the mechanism of enzyme-catalyzed phospho group transfer, the stereochemical course at phosphorus of four enzymes has been determined. First, using adenosine (..gamma..-(S)-/sup 16/O, /sup 17/O, /sup 18/O)triphosphate as the substrate, the reaction catalyzed by creatine kinase has been found to proceed with overall inversion of configuration at phosphorus. Second, using adenosine (..beta..-(S)-/sup 16/O, /sup 17/O, /sup 18/O)diphosphate as the substrate, the reaction catalyzed by adenylate kinase has been found also to proceed with overall inversion. Third, the reaction catalyzed by phosphoenolpyruvate carboxylase has been studied using ((S/sub p/)-/sup 16/O, /sup 17/O)thiophospoenolpyruvate as the substrate in H/sub 2/ /sup 18/O. Fourth, using adenosine 5'-O-((..gamma..S/sub p/)-..beta gamma..-/sup 17/O,..gamma..-/sup 17/O,/sup ...

International Nuclear Information System (INIS)

Elastic scattering of 22 MeV alpha particles by "2"3Na, sup(24-25-26)Mg, "2"7Al and "2"8Si has been measured between 24"0 and 174"0 lab. Partial angular distributions, from 120"0 to 174"0, were also measured at incident energies of 18.4 and 20.7 MeV for "2"4Mg, and 18.9 and 20.5 MeV for "2"8Si. The most striking feature of the data is the large angle behaviour: spin-zero nuclei display more pronounced backward oscillations and the cross section rises more steeply towards 180"0 for 4n nuclei than for the others. (Z.M.).

British Library Electronic Table of Contents (United Kingdom)

In closed systems, the O2 compensation point (?O) was previously defined as the upper limit of O2 level, at a given CO2 level, above which plants cannot have positive carbon balance and survive. Studies with 18O2 measure the actual O2 uptake by photorespiration due to the dual function of Rubisco, the enzyme that fixes CO2 and takes O2 as an alternative substrate. One-step modelling of CO2 and O2 uptakes allows calculating a plant specificity factor (Sp) as the sum of the biochemical specificity of Rubisco and a biophysical specificity, function of the resistance to CO2 transfer from the atmosphere to Rubisco. The crossing points (Cx, Ox) are defined as CO2 and O2 concentrations for which O2 and CO2 uptakes are equal. It is observed that: (1) under the preindustrial atmosphere, photorespir...

International Nuclear Information System (INIS)

To make the doubly labelled water method for determining energy expenditure more applicable in a free-living population, collection of a single daily urine or breath sample would have advantages compared to a 24-hr urine collection. Coward et al. reported the use of a single daily urine sample. In the previously described study, a single urine collection and a fasting morning breath sample were collected from four men during two 21-day periods (fall, F, spring, S) while maintaining their body wts. on controlled diets (20% calories from protein, 40% from fat, 60% from CHO [F]; 20% protein, 20% fat, 60% CHO [S]). Urine and breath samples were analyzed to determine disappearance rates of D and "1"8O for up to 21 days. Values were compared with metabolizable energy intake levels (EI), with or without corrections for estimated changes in body composition assessed by several methods. Preliminary evaluations suggest that the single daily urine sample values may overestimate and values from ...

International Nuclear Information System (INIS)

We describe a compact ultrafiltration system for the removal of pyrogens and bacteria from water labeled with the stable isotopes of deuterium and oxygen-18. The ultrafiltration system is constructed from readily available commercial components and can achieve complete removal of pyrogens and bacteria from 1L contaminated water within 30 min. By use of our procedure, loss of the isotopically labeled water by retention in the filtration system was minimal. The purified water is suitable for both oral and intravenous administration to healthy human subjects participating in nutrition studies.

British Library Electronic Table of Contents (United Kingdom)

The Eph tyrosine kinase receptors and their ephrin ligands play a central role in several human cancers and their deregulated expression or function promotes tumorigenesis, inducing aggressive tumor phenotypes. Green tea extracts (GTE) have been recently found to inhibit Eph-kinase phosphorylation. In order to evaluate the potential contribution of edible and medicinal plants on EphA2-ephrinA1 modulation, 133 commercially available plant extracts used as food supplements, essential and fixed oils were screened with an ELISA-based binding assay. Nine plant extracts, rich of polyphenols, reversibly inhibited binding in a dose-dependent manner (IC"5"0 0.83-24@mg/ml). Functional studies on PC3 prostate adenocarcinoma cells revealed that active extracts antagonized ephrinA1-Fc-induced EphA2-pho...

International Nuclear Information System (INIS)

The "2"0 "2"1 "2"2Ne("6Li, d)"2"4 "2"5 "2"6Mg reactions have been studied at a bombarding energy of 32 MeV. Alpha particle spectroscopic strengths have been extracted for several low-lying levels by a finite-range distorted wave analysis. These are compared with theoretical predictions. The agreement is good both for relative strengths to different levels within a nucleus and for ground-state strengths relative to the "1"6O("6Li, d) result. Strengths calculated using eigenfunctions determined in large shell-model computations agree well with pure symmetry SU(3) predictions. The "2"1Ne("6Li, d) angular distributions for transitions to the ground-state band of "2"5Mg are characterized by the lower of the two L-transfers allowed for populating each level. For the 3"+(5.24 MeV) unnatural parity level in "2"4Mg, a two-step calculation gives a better account of the data than does a compound nuclear calculation. (Auth.).

Energy Technology Data Exchange (ETDEWEB)

Total mercury (THg), methylmercury (MeHg) and 22 other trace elements were measured in ice algae, three species of zooplankton, mixed zooplankton samples, Arctic cod (Boreogadus saida), ringed seals (Phoca hispida) and eight species of seabirds to examine the trophodynamics of these metals in an Arctic marine food web. All samples were collected in 1998 in the Northwater Polynya (NOW) located between Ellesmere Island and Greenland in Baffin Bay. THg and MeHg were found to biomagnify through the NOW food web, based on significant positive relationships between log THg and log MeHg concentrations vs. {delta} {sup 15}N muscle and liver . The slope of these relationships for muscle THg and MeHg concentrations (slope = 0.197 and 0.223, respectively) were similar to those reported for other aquatic food webs. The food web behavior of THg and {delta} {sup 15}N appears constant, regardless of trophic state ...

International Nuclear Information System (INIS)

In this paper, steady-state isotopic transient kinetic analysis (SSITKA) is used to study two model reactions, CO oxidation and CO-NO reactions, on a typical formulation of a three-way auto-catalyst. Under steady-state conditions, abrupt switches in the isotopic composition of CO ("1"2C"1"6O/"1"3C"1"8O) were carried out to produce isotopic transients in both labeled reactants and products. Along with the determination of the average surface lifetimes and concentrations of reaction intermediates, an analysis of the transient responses along the carbon reaction pathway indicated that the distribution of active sites for the formation of CO_2 was bimodal for both reactions. Furthermore, relatively few surface sites contributed to the overall reaction rate.

International Nuclear Information System (INIS)

The determination of ratio of neutron over proton matrix elements by inelastic proton scattering, for 0"+#->#2"+ transitions, is investigated via the comparison between experimental data and theoretical calculations. Calculations into the context of a macroscopic and a microscopic description are performed for a wide mass range nuclei: "1"8O, "3"0Si, "3"2","3"4S, "4"8Ca, "8"8Sr, for which these ratios were determined previously with an independent technique. At that point the choice of the theoretical model may be very critical. It is thus the purpose of this investigation to point out the most suitable model. It is found that in general both theoretical models can be employed for the reliable determination of neutron over proton matrix element ratios.

International Nuclear Information System (INIS)

A compact, quasi-4? position sensitive silicon array, TIARA, designed to study direct reactions induced by radioactive beams in inverse kinematics is described here. The Transfer and Inelastic All-angle Reaction Array (TIARA) consists of 8 resistive charge division detectors forming an octagonal barrel around the target and a set of double-sided silicon-strip annular detectors positioned at each end of the barrel. The detector was coupled to the ?-ray array EXOGAM and the spectrometer VAMOS at the GANIL Laboratory to demonstrate the potential of such an apparatus with radioactive beams. The 14N(d,p)15N reaction, well known in direct kinematics, has been carried out in inverse kinematics for that purpose. The observation of the 15N ground state and excited states at 7.16 and 7.86 MeV is presented here as well as the comparison of the measured proton angular distributions with DWBA calculations. ...

Science.gov (United States)

We have designed a new nucleobase, benzodeazaadenine (BDA) that has a stronger charge transport ability than guanine and is not destroyed during charge transport process. By incorporating this new nucleobase into DNA, we demonstrated a protocol for real DNA nano-wire that is far superior to natural DNA. We also demonstrated that the selectivity for the interaction of Mn(II) ion with guanine N7 in G runs is a HOMO-controlled process, and as a consequence, the selectivity for G-metal ion interactions obtained by 15N-NMR studies would directly reflect the HOMO distribution of G-containing sequences in B-DNA. PMID:12903077

International Nuclear Information System (INIS)

The high nutrient nitrogen and organic matter contents of sewage sludge (SS) make it a potential organic fertilizer for sandy soil. In this study, "1"5N-labelled ammonium sulphate was used to investigate the availability of nitrogen from irradiated and non-irradiated sewage sludge to tomato plants. The application of sewage sludge to sandy soil increased dry matter production (DMP), nitrogen yield (NY) and nitrogen recovery (NR) over two successive years. A positive relationship was found between sludge application rate and DMP and NY. The increase was significantly higher (P=0.05) in irradiated than non-irradiated sewage sludge. Total nitrogen derived from non-irradiated sewage sludge are : 48.0, 63.7, 73.5, 105.2 Kg/ha, whereas, the total nitrogen derived from irradiated sewage sludge are: 55.1, 72.5, 88.9, 141.4 Kg/ha corresponding to application rates of 10 t/ha, 20 t/ha, 30 t/ha, respectively. This was attributed to higher dry matter production in the later than the former. A ...

International Nuclear Information System (INIS)

In the present study 12 diets, each one consisting of a pool of seven day diets, composed by four meals: breakfast, lunch, dinner and snack, adequate in energy and macro nutrients according to the RDA (Recommended Daily Allowance) recommendations, were elaborated and offered to a group of 12 men (19-42 years). The diets were collected by duplicate portion technique and dried by two different processes: freeze drying and 60 deg C ventilated oven drying. In the total, 24 diets were analyzed. The content of some minerals and trace elements (Ca, Fe, Mg, Mn, Na, Se and Zn) were determined by Instrumental Neutron Activation Analysis. The validation of methodology was made by analysis of the reference materials Typical Diet (NIST SRM 1548"a), Orchard Leaves (NIST SRM 1541) and Peach Leaves (NIST SRM 1547). The results observed by two different drying processes used were statistically compared by test T of Student. It was possible to conclude that the concentration means can be considered as ...

International Nuclear Information System (INIS)

Due to severe drought conditions in Pakistan over the past several years, most of the areas are facing extinction of its potable water reserves and inadequate replenishment of groundwater aquifers. Due to over exploitation, the groundwater flow dynamics is changing and water quality is degrading due to induced infiltration from polluted surface sources. Isotope hydrology is relatively a new discipline having great potential for studying various water-related problems. RIAD, PINSTECH has established analytical facilities for commonly used environmental isotopes and applied to investigate various hydrological problems. This paper briefly describes practical examples on recharge mechanism and dating of groundwater in Lahore and Ziarat areas using isotopes like deuterium (/sup 2/H), Oxygen-18 (/sup 18/O), Tritium (/sup 3/H) and CFCs in water. In Lahore, the areas having different contribution of the river Ravi in groundwater recharge have been ...

CERN Document Server

We report the results of mapping observations of the bipolar nebula with SiO maser emission, IRAS 19312+1950, in the CO (J=1-0 and J=2-1), 13CO (J=1-0 and J=2-1), C18O (J=1-0), CS (J=2-1), SO (J_K=3_2-2_1) and HCO+ (J=3-2) lines with the Berkeley-Illinois-Maryland Association array. Evolutional status of this source has been evoking a controversy since its discovery, though SiO maser sources are usually identified as late-type stars with active mass loss. In line profiles, two kinematical components are found as reported in previous single-dish observations: a broad pedestal component and a narrow component. Spatio-kinetic properties of a broad component region traced by 12CO lines are roughly explained by a simple spherical outflow model with a typical expanding velocity of an AGB star, though some properties of the broad component region still conflict with properties of a typical AGB spherical outflow. A narrow component region apparently ...

Energy Technology Data Exchange (ETDEWEB)

Gamma-aminobutyric acid type A receptor-associated protein (GABARAP) belongs to a family of small ubiquitin-like adaptor proteins implicated in intracellular vesicle trafficking and autophagy. We have used diffusion-ordered nuclear magnetic resonance spectroscopy to study the temperature and concentration dependence of the diffusion properties of GABARAP. Our data suggest the presence of distinct conformational states and provide support for self-association of GABARAP molecules. Assuming a monomer-dimer equilibrium, a temperature-dependent dissociation constant could be derived. Based on a temperature series of {sup 1}H{sup 15}N heteronuclear single quantum coherence nuclear magnetic resonance spectra, we propose residues potentially involved in GABARAP self-interaction. The possible biological significance of these observations is discussed with respect to alternative scenarios of oligomerization.

International Nuclear Information System (INIS)

Endurance-trained older men have a higher proportion of lean tissue and greater muscle cell oxidative capacity, reversing age-related trends and suggesting major changes in protein metabolism. In this study, protein turnover was determined in 6 middle-aged (52+/-1 yr) men who were well trained (VO_2 max 55.2+/-5.0 ml O_2/kg.min) and lean (body fat 18.9+/-2.8%, muscle mass 36.6+/-0.6%). The maintained habitual exercise while consuming 0.6, 0.9 or 1.2 g protein/kg.day for 10-day periods. N flux was measured from "1"5N in urea after oral "1"5N-glycine administration. Myofibrillar protein breakdown was estimated from urinary 3-methyl-histidine. Dietary protein had no effect on turnover rates, even when N balance was negative. Whole body protein synthesis was 3.60+/-0.12 g/kg.day and breakdown was 3.40+/-0.14 g/kg.day for all N intakes. Whole body protein flux, synthesis and breakdown were similar to values reported for sedentary young (SY) or sedentary old (SO) men on comparable diets. ...

International Nuclear Information System (INIS)

Effect of two organic chemicals viz., 2,4-dinitrophenyl hydrazone (C_1) and naphthyl ethylene diamine (C_2) was studied by their application alone and together (Csub(1+2) at the rate of 10 ppm by growing wheat on a loamy soil (Typic ustochrept) containing recently immobilized fertilizes N of "1"5N - urea applied at 60, 120 and 180 ppm N to preceding rice under greenhouse conditions of a rice-wheat sequence. The application of C_1 and C_2 alone; and their combined application (Csub(1+2) produced 12, 15 and 18 per cent higher wheat grain yield over no-chemical application i.e. Co (3.50 g/pot). The chemicals also showed their beneficial effect on utilization of recently immobilized fertilizer N, as was evidenced by significantly higher "1"5N recovery values in wheat with C_1, C_2 and Csub(1+2)(2.84, 3.63 and 3.54 per cent, respectively) than that of Co (2.29 per cent). The soil N fractions were affected by chemical application during wheat as total hydrolyzable N, hydrolyzable ...

International Nuclear Information System (INIS)

Protected cultures are widespread along the Lebanese narrow coastline, encouraged by mild winter conditions. Although one of the most intensive production systems, water and nutrients managements are mostly empirical, based on the experience of the grower himself or of his workers. So far, water has been available in Lebanon, but it will become scarce within ten years. The conservation of water quality by a rational addition of nutrients is particularly relevant to protected cultures. This is important as greenhouses are developed on imported shallow soils that could be fragile and highly vulnerable to pollution. Sound management includes the amount and the forms of fertilizers as well as the modality of fertigation. An experiment was conducted during two spring seasons in a location along the northern coast in a typical unheated greenhouse. The cucumber response to two frequencies and modalities of fertigation was followed: continuous T2C and T3C and discontinuous T2D and T3D every ...

Energy Technology Data Exchange (ETDEWEB)

A concept for a fast spectrum irradiation facility has been developed for insertion in the High Flux Isotope Reactor at Oak Ridge National Laboratory. The design is based on the very large fast flux that is available in this reactor combined with the use of a strongly-absorbing thermal neutron shield. The preferred concept from the several considered consists of a three-pin design surrounded by a Eu{sub 2}O{sub 3} thermal neutron shield located in the reactor flux trap. Preliminary analyses showed that this concept can provide a fast flux larger than 1x10{sup 15} n/cm{sup 2}{center_dot}s and a fast-to-thermal flux ratio greater than 300 while having an acceptable impact on the HFIR operation. Additional analyses are necessary to confirm that this design is feasible and meets the requirements for fast fuel irradiation. If the design proves to be suitable, it can provide a relatively low-cost, near-term capability.

Energy Technology Data Exchange (ETDEWEB)

The mechanisms involved in the glacial inception are still poorly constrained due to a lack of high resolution and cross-dated climate records at various locations. Using air isotopic measurements in the recently drilled NorthGRIP ice core, we show that no evidence exists for stratigraphic disturbance of the climate record of the last glacial inception ({proportional_to}123-100 kyears BP) encompassing Dansgaard-Oeschger events (DO) 25, 24 and 23, even if we lack sufficient resolution to completely rule out disturbance over DO 25. We quantify the rapid surface temperature variability over DO 23 and 24 with associated warmings of 10{+-}2.5 and 16{+-}2.5 C, amplitudes which mimic those observed in full glacial conditions. We use records of {delta}{sup 18}O of O{sub 2} to propose a common timescale for the NorthGRIP and the Antarctic Vostok ice cores, with a maximum uncertainty of 2,500 years, and to examine the interhemispheric sequence of events ...

Energy Technology Data Exchange (ETDEWEB)

Late plagiogranite bodies in the Semail ophiolite have been previously suggested to represent late stage fractionates within an episodic spreading center magma chamber or the roots of seamount chains. Field and lab observations suggest that these late silicic magma chambers represent zones of repeated injection by dikes of intermediate to mafic composition. Multiple generations of intrusion, partial resorption and reintrusion are preserved in the plagiogranite as 1) relict phantom xenoliths, 2) angular xenoliths with quartz-rich margins, 3) deformed fine-grained dikes with distinct chilled margins, and 4) planes of rectangular blocks with cuspate margins or ellipsoids of similar fine grained mafic materials. The blocks and ellipsoids are actually dismembered mafic dikes that chilled by intruding a cooler silicic liquid and were either thermally fractured or pinched out. All of the dikes are hydrothermally altered to assemblages including amph., qtz., epi., preh., and chl. and are ...

Energy Technology Data Exchange (ETDEWEB)

The effect of powder particle sizes of n- and p-Bi2Te3 on the thermoelectric properties has been studied. The powder was formed from the each ingot and sieve into <63, 63-90 and 90-150{mu}m for p-type, and <355 and >355 {mu}m for n-type. Those powders are pressed followed by CIP, then sinterd at 773K for S. Effects of CIP on the densities were not so large such as 1-4% depending on the powder sizes. The Setback coefficients and electric conductivities for p-type were 110{mu}V/K and 0.8{times}10{sup 2}ohm{sup -1}m{sup -1} at 333K, while 18O{mu}V/K and 2.0{times}10{sup 4}ohm{sup -1}m{sup -l} for n-type, respectively. The thermal conductivity for n-type was 0.7W/mK leading to the figure of merit of 2.1{times}10{sup -3}(/K). The hybrid texture of the suitable amount of smaller and larger grains has a possibility of an improvement for thermoelectric properties. 10 refs., 5 figs., 5 tabs.

International Nuclear Information System (INIS)

The autors examined the hypothesis that current recommendations on dietary energy requirements may underestimate the total energy needs of young adult men, by measuring total energy expenditure (TEE) and resting energy expenditure (REE) in 14 weight-maintaining healthy subjects leading unrestricted lives. TEE and body composition were measured by using 2H(2)18O, and REE was measured by using indirect calorimetry. All subjects had sedentary full-time occupations and participated in strenuous leisure activities for 34 #+-# 6 (SE) min/d. TEE and REE were 14.61 #+-# 0.76 and 7.39 #+-# 0.26 MJ/d, respectively, and 202 #+-# 2 and 122 #+-# 2 kJ.kg-1.d-1. There were significant relationships between TEE and both body fat-free mass (r = 0.732, P less than 0.005) and measured REE (r = 0.568, P less than 0.05). Measured TEE:REE values were significantly higher than the recommended energy requirement (1.98 #+-# 0.09, compared with 1.55 or 1.67, P less than ...

International Nuclear Information System (INIS)

The improving uranium extraction efficiency of yellow cake production from shale deposit by acid pugging and curing with D263B resin adsorption is described in this paper. The analysis and examination show that the composition of uranium minerals in one of uranium ores is very complex, which directly influence the extraction efficiency of uranium and processing technology. Conventional experimental results indicate that uranium leaching efficiency is changed between 50?60% by conventional agitation method. In this case, acid pugging and curing experiments are employed in order to improving the extraction efficiency. A series of acid pugging and curing experiments are carried out to get parameters for heap leaching in pilot plant experiment. The experiment results by acid pugging and curing technology showed that uranium leaching efficiency can reach to 90% of extraction efficiency mixed with 1% manganese dioxide, 12% sulfuric acid pugging, curing 3 days and leached out with 5 g.L-1 ...

International Nuclear Information System (INIS)

Austenitic stainless steels (304-type) have been implanted with nitrogen ions in order to investigate the effects of implanted nitrogen on their electrochemical behaviour and on the nature of the passive film formed on the steels in acid (0.5M H_2SO_4). Alloys with two nitrogen doses have been prepared (2.5x10"1"6 and 2x10"1"7 N atoms/cm"2). The implanted alloys have been characterized by "1"5N-NRA (nuclear reaction analysis) and XPS (X-ray photoelectron spectroscopy). Alloy surfaces with well-defined N concentrations were prepared, prior to the electrochemical measurements, by argon-ion sputtering of the implanted material for a fixed time in order to reach a well-defined point on the nitrogen depth profile. The samples were then transferred without exposure to air to an electrochemical cell mounted in an inert gas glove box. The implanted nitrogen modifies the electrochemical behaviour of the alloy. The anodic dissolution in the active state is enhanced, and the current density in ...

Energy Technology Data Exchange (ETDEWEB)

NMR spectroscopy combined with paramagnetic relaxation agents was used to study the positioning of the 40-residue Alzheimer Amyloid {beta}-peptide A{beta}(1-40) in SDS micelles. 5-Doxyl stearic acid incorporated into the micelle or Mn{sup 2+} ions in the aqueous solvent were used to determine the position of the peptide relative to the micelle geometry. In SDS solvent, the two {alpha}-helices induced in A{beta}(1-40), comprising residues 15-24, and 29-35, respectively, are surrounded by flexible unstructured regions. NMR signals from these unstructured regions are strongly attenuated in the presence of Mn{sup 2+} showing that these regions are positioned mostly outside the micelle. The central helix (residues 15-24) is significantly affected by 5-doxyl stearic acid however somewhat less for residues 16, 20, 22 and 23. This {alpha}-helix therefore resides in the SDS headgroup region with the face with residues 16, 20, 22 and 23 directed away from the hydrophobic interior of the micelle. ...

Energy Technology Data Exchange (ETDEWEB)

Interactions beween a high latitude, continental shelf, spring phytoplankton bloom and water column physics and chemistry were studied using /sup 15/N measured rates of nitrogen uptake. Peak bloom conditions commenced when the mixed layer shallowed and minimized respirational losses. Integrative light-mixing growth models were accurate during early bloom stages. An advection-diffusion model associated peak bloom nitrate uptake with pycnocline mixing rates of 2.1 m d/sup -1/ in an 18 m mixed layer. Maximum nitrogen specific uptake rates (hr/sup -1/), unlike those of carbon, coincided with peak bloom conditions. Although species compositions among peak bloom periods were similar, particulate C/N ratios were not. Apparently, both intercellular factors and prevailing mixing conditions influence specific uptake rates and cell composition. A large proportion of new (nitrate) to total productivity was associated with the dominance of the early bloom ...

International Nuclear Information System (INIS)

The beneficial effect of compost application to the sandy soil on dry matter production of shoots and fruits as well as its effect on l5N-uptake and nitrogen utilization percent of cucumber plant (Cucumis sativus L.) were studied under field conditions. Two types of natural compost (i.e. sugar cane bagasse (SC) and beet compost (BC)) with three levels (2, 4, 6 ton/fed) in addition to check treatment for each kind of compost (sheep manure with rate of 20 in/fed) combined with three rates of nitrogen fertilizer rates (50, 75, 100% from the recommended rate, i.e. 75 kg /fed) were used. The bagasse compost in both seasons gave a significantly higher response than the beet compost. There was a greet reduction in cucumber dry weight, N yield, Ndff%, FN yield and N utilization % of shoots and fruits as the level of compost application decreased. However, cucumber plants grown on high compost application level (6 ton/fed) were similar in their responses to plants grown on the check treatment. ...

Energy Technology Data Exchange (ETDEWEB)

Micron-size Ni-base alloy (NBA) powders were mixed with both 1.5 wt.% (hereinafter %) micron-size CeO{sub 2} (m-CeO{sub 2}) and also 1.5% and 3.0% nano-size CeO{sub 2} (n- CeO{sub 2}) powders. These mixtures were coated on low-carbon steel (Q235) by 2.0 kW CO{sub 2} laser cladding. The effects on the microstructures, phases and electrochemical corrosion of the coatings upon the addition of m- and n- CeO{sub 2} powders to NBA (m- and n- CeO{sub 2} /NBA) have been investigated. The results showed that a smooth coating was prepared under suitable processing parameters (P= 2.0 kW, V= 180 mm min{sup -1}) by adding 1.5% n- CeO{sub 2}. In addition to the primary phases of {gamma}-Ni, Cr{sub 23} C{sub 6} and Ni{sub 3} B in the Ni-base alloy coating, CeNi{sub 3} was formed in Ni-base alloy coatings with both n- CeO{sub 2} and m-CeO{sub 2} particles, and CeNi{sub 5} appeared in the coating upon decreasing the size of CeO{sub 2} particles. Well-developed dendrites were observed in the Ni-base ...

International Nuclear Information System (INIS)

Analyzing various SBLOCA with high pressure safety injection (HPSI) at VVER-440/213, we met a surprising phenomenon - a 'natural' circulation post SG heat transfer reversal. This is not usual, because normal natural circulation (NC) in primary circuit is connected with positive heat transfer at SG. If there is reverse heat transfer at SG (as soon as the break enthalpy outflow is sufficient for removal of reactor decay heat), it should obstruct any natural circulation. The question was, what is the driving force of this 'non-standard natural circulation'. After all we revealed that force - it is the density difference between the colder water in reactor downcomer (cold water from HPSI) and warmer water in inner reactor (lower plenum, core, upper plenum). This phenomenon could be confusing for operating personal, because there would be an opposite temperature difference at the loop than by normal natural circulation (under non-standard NC conditions water is heated in SG so there is ...

Science.gov (United States)

The purpose of this study was to correlate histopathological with CT findings in patients suffering from hepatocellular carcinoma (HCC) eligible for orthotopic liver transplantation (OLT), with a special focus on the antitumoral effect of transarterial chemoembolization (TACE) therapy. A total of 42 consecutive patients suffering from HCC had been treated prior to OLT by means of TACE. TACE was carried out with a mixture of Lipiodol (10-20 ml) and mitomycin C (max. dosage, 10 mg). TACE was performed at 6- to 8-week intervals. Follow-up investigation included contrast-enhanced multislice CT controls and laboratory control. Liver explants were evaluated macroscopically and microscopically to determine the number and size of the tumor lesions as well as the degree of tumor necrosis. Necrosis was investigated in H and E-stained sections. The degree of necrosis was classified as follows: 0-25%, 26-50%, 51-75%, 75-99%, and complete necrosis. Two hundred thirty-one TACE procedures (5.5 {+-} ...