WorldWideScience
1

Genetic markers for lactation persistency in primiparous Australian dairy cows  

British Library Electronic Table of Contents (United Kingdom)

Good performance in extended lactations of dairy cattle may have a beneficial effect on food costs, health, and fertility. Because data for extended lactation performance is scarce, lactation persistency has been suggested as a suitable selection criterion. Persistency phenotypes were calculated in several ways: P1 was yield relative to an approximate peak, P2 was the slope after peak production, and P3 was a measure derived to be phenotypically uncorrelated to yield and calculated as a function of linear regressions on test-day deviations of days in milk. Phenotypes P1, P2, and P3 were calculated for sires as solutions estimated from a random regression model fitted to milk yield. Because total milk yield, calculated as the sum of daily sire solutions, was correlated to P1 and P2 (r=0.30 ...

2010-01-01

2

Physiologically Based Pharmacokinetic Modeling of Fetal and Neonatal Manganese Exposure in Humans: Describing Manganese Homeostasis during Development  

British Library Electronic Table of Contents (United Kingdom)

Concerns for potential vulnerability to manganese (Mn) neurotoxicity during fetal and neonatal development have been raised due to increased needs for Mn for normal growth, different sources of exposure to Mn, and pharmacokinetic differences between the young and adults. A physiologically based pharmacokinetic (PBPK) model for Mn during human gestation and lactation was developed to predict Mn in fetal and neonatal brain using a parallelogram approach based upon extrapolation across life stages in rats and cross-species extrapolation to humans. Based on the rodent modeling, key physiological processes controlling Mn kinetics during gestation and lactation were incorporated, including alterations in Mn uptake, excretion, tissue-specific distributions, and placental and lactational transfer ...

2011-01-01

4

Evaluation of models to predict the stoichiometry of volatile fatty acid profiles in rumen fluid of lactating Holstein cows  

British Library Electronic Table of Contents (United Kingdom)

Volatile fatty acids (VFA), produced in the rumen by microbial fermentation, are the main energy source for ruminants. The VFA profile, particularly the nonglucogenic (acetate, Ac; butyrate, Bu) to glucogenic (propionate, Pr) VFA ratio (NGR), is associated with effects on methane production, milk composition, and energy balance. The aim of this study was to evaluate extant rumen VFA stoichiometry models for their ability to predict in vivo VFA molar proportions. The models were evaluated using an independent data set consisting of 101 treatments from 24 peer-reviewed publications with lactating Holstein cows. All publications contained a full diet description, rumen pH, and rumen VFA molar proportions. Stoichiometric models were evaluated based on root mean squared prediction error (RMSPE)...

2011-01-01

5

Inhibition of lactate dehydrogenase A induces oxidative stress and inhibits tumor progression  

UK PubMed Central (United Kingdom)

As the result of genetic alterations and tumor hypoxia, many cancer cells avidly take up glucose and generate lactate through lactate dehydrogenase A (LDHA), which is encoded by a target gene of c-Myc...Full Text Available

2010-02-02

6

Radiosensitization of human lung fibroblasts by chemicals that decrease ATP levels  

International Nuclear Information System (INIS)

Radiosensitization by lactate, pyruvate, nalidixic acid and novobiocin was studied in exponentially growing SH-18L human lung fibroblasts. All the chemicals had a slight radiosensitizing effect at a low concentration and a definite effect at a higher one. Decreases in the D_0 and/or Dq values were present in each dose survival curve. Fibroblasts incubated with the low concentration of each chemical for 24 hrs after X irradiation showed no reduction in intracellular ATP content, whereas, the higher concentration produced a significant decrease. These observations suggest that the decrease in the ATP content may be involved in the radiosensitization of human fibroblasts at high concentrations of these chemicals. In contrast, radiosensitization at a low concentration is not explained by a relationship to ATP content. Different mechanisms may be involved in radiosensitization at low and high concentrations of these chemicals. (author).

9

A mass action model of the dose-response curve of immunoradiometric assay and its curve fitting  

International Nuclear Information System (INIS)

In view of no satisfactory mathematical model is presently available for the dose-response curve of immunoradiometric assay, a three parameter model based on single binding site mass action law has been derived. A curve fitting method based on similar principle of linear robust regression was designed and a software was prepared for use on IBM personal computers. Experiments revealed that the model is applicable to a variety of IRMA systems as well as to time-resolved immunofluorometric assay of hAFP. When there was outlier(s) of the calibration curve, the average bias of unknown samples obtained with this method is significantly smaller than methods using four parameter logistic model or four parameter single site mass action model.

10

A gravitational diffusion model without dark matter  

UK PubMed Central (United Kingdom)

In this model, without dark matter, the flat rotation curves of galaxies and the mass-to-light ratios of clusters of galaxies are described quantitatively. The hypothesis is that the agent of gravitational...Full Text Available

1998-03-31

11

Utilization of intestinal triglyceride-rich lipoproteins in mammary gland of cows.  

Science.gov (United States)

Elution profiles of total lipoproteins, apolipoprotein B (apoB) concentrations in lipoproteins, and plasma triglyceride (TG) levels were examined in early-, late-, and non-lactating cows. Additionally, arteriovenous (A-V) differences were also measured to elucidate the uptake of TG and apoB-containing lipoproteins in mammary gland. Non-lactating cows showed three major peaks corresponding to triglyceride-rich lipoprotein (TRL), low density lipoprotein (LDL), and high density lipoprotein (HDL) fraction, whereas both early- and late-lactating cows revealed two peaks corresponding to TRL and HDL. The peak area of TRL in early- and late-lactating cows were significantly (p < 0.05) smaller than that in non-lactating cows. The plasma TG levels and apoB-48 concentrations of TRL in early- and late-lactating cows were also significantly (p < 0.01) lower. ...

1999-10-01

12

Prolonged Blood Storage Does Not Effect Survival in an Animal Model of Hemorrhagic Shock  

British Library Electronic Table of Contents (United Kingdom)

Summary Background: Red blood cell (RBC) transfusion in hemorrhagic shock is life saving. However, several clinical trials have shown that blood transfusion in the critically ill patient might be associated with adverse outcomes. Furthermore, an association between prolonged blood storage and adverse effects of RBC transfusion has been postulated. The aim of this study is to examine the effect of blood storage time on resuscitation outcome, in an animal model of hemorrhagic shock. Methods: 20 Wistar rats were phlebotomized in order to induce reversible hemorrhagic shock. Half of them were resuscitated with blood stored for a short period of time (4 days), and the other ones were resuscitated with blood stored for a prolonged time (14 days). Blood samples for hemoglobin, pH, lactate, bicarb...

2011-01-01

13

GIT Constructions of Moduli Spaces of Stable Curves and Maps  

CERN Document Server

This largely expository paper first gives an introduction to Hilbert stability and its use in Gieseker's GIT construction of $\\overline{M}_g$. Then I review recent work in this area--variants for unpointed curves that arise in Hassett's log minimal model program, starting with Schubert's moduli space of pseudostable curves, and constructions for weighted pointed stable curves and for pointed stable maps due to Swinarski and to Baldwin and Swinarski respectively. The focus is on the steps at which new ideas are needed. Finally, I list open problems in the area, particularly some arising in the log minimal model program that seem inaccessible to current techniques.

2008-01-01

14

Peripartal changes in serum alkaline phosphatase activity and lactate dehydrogenase activity in dairy cows.  

UK PubMed Central (United Kingdom)

Peripartal serum alkaline phosphatase activity and lactate dehydrogenase activity were measured in 30 dairy cows in order to examine the association between retained fetal membranes and enzyme activity....Full Text Available

1987-10-01

15

Milk residues and performance of lactating dairy cows administered high doses of monensin  

UK PubMed Central (United Kingdom)

AbstractMilk residues and performance were evaluated in lactating cows that were fed up to 10 times the recommended dose of monensin. Following an acclimatization period of 14 d, during...Full Text Available

2005-07-01

16

DDE and shortened duration of lactation in a northern Mexican town.  

UK PubMed Central (United Kingdom)

OBJECTIVES. Worldwide declines in the duration of lactation are cause for public health concern. Higher levels of dichlorodiphenyl dichloroethene (DDE) have been associated with shorter durations of...Full Text Available

1995-04-01

17

Bragg curve spectroscopy  

CERN Document Server

Bragg curve spectroscopy

1981-01-01

19

Clostridiaceae and Enterobacteriaceae as active fermenters in earthworm gut content  

British Library Electronic Table of Contents (United Kingdom)

The earthworm gut provides ideal in situ conditions for ingested heterotrophic soil bacteria capable of anaerobiosis. High amounts of mucus- and plant-derived saccharides such as glucose are abundant in the earthworm alimentary canal, and high concentrations of molecular hydrogen (H2) and organic acids in the alimentary canal are indicative of ongoing fermentations. Thus, the central objective of this study was to resolve potential links between fermentations and active fermenters in gut content of the anecic earthworm Lumbricus terrestris by 16S ribosomal RNA (rRNA)-based stable isotope probing, with [13C]glucose as a model substrate. Glucose consumption in anoxic gut content microcosms was rapid and yielded soluble organic compounds (acetate, butyrate, formate, lactate, propionate, succi...

2011-01-01

20

Thermodynamic, Transport and Chemical Properties of " ...  

Science.gov (United States)

... Chem. Res., in press, 2006. 8. Smith, BL, Bruno, TJ, Advanced distillation curve measurement with a model predictive temperature controller. Int. ...

2006-06-01

21

SS 433 as a black hole candidate  

Energy Technology Data Exchange (ETDEWEB)

The inverse problem of interpreting the SS 433 optical light curves is solved for a geometrically thick model accretion disk around the compact relativistic object: most likely a black hole.

1985-01-01

22

Research on improving utilization efficiency of photoelectric cell by using fluorescence material  

Energy Technology Data Exchange (ETDEWEB)

This paper proves that it is practicable to build a new power model which can work efficiently at night by using a type of fluorescence material. The utilization efficiency of photovoltaic cell is improved by prolonging the actual working hours of the cell within 24 hours. Both theoretical analysis and experiment on this model are carried out, and base on which the current-time curve (I-t curve) is depicted. It shows that the model which applies the fluorescence material to photovoltaic system is available. According to the analysis and comparison between the attenuating curve of the material and I-t curve of the power system, we can conclude that the weak illumination and the mismatch on wavelength are primary reasons for the low current. Finally, several improved measures of this power model for practical application ...

2008-07-01

23

Robust curve fitting method for single binding site mass action model of radioimmunoassay  

International Nuclear Information System (INIS)

The difficulty and unstability of the parameter estimation of mass action model for radioimmunoassay are the major obstacles to its application in routine work. A unique robust curve fitting method for the mass action model was introduced. large numbers of simulated data were generated with Monte Carlo method to compare the accuracy and robustness of the robust fitting and the least squre fitting (Marquardt method) of the mass action model. The results demonstrated that the new robusst method significantly increased the accuracy and reliability of data processing with the mass action model. It also markedly reduced the influence of outliers in the fitting of RIA data, and it was always 'convergent'. This robust method could also be applied to other mathematical models which can be transformed into high degree equations and no initial estimates are needed for ...

24

Automatic interpretation of Schlumberger soundings  

Energy Technology Data Exchange (ETDEWEB)

The automatic interpretation of apparent resistivity curves from horizontally layered earth models is carried out by the curve-fitting method in three steps: (1) the observed VES data are interpolated at equidistant points of electrode separations on the logarithmic scale by using the cubic spline function, (2) the layer parameters which are resistivities and depths are predicted from the sampled apparent resistivity values by SALS system program and (3) the theoretical VES curves from the models are calculated by Ghosh's linear filter method using the Zhody's computer program. Two soundings taken over Takenoyu geothermal area were chosen to test the procedures of the automatic interpretation.

1980-09-01

25

GRBs Light Curves - Another Clue on the Inner Engine  

CERN Document Server

The nature of the `inner engine' that accelerate and collimate the relativistic flow at the cores of GRBs is the most interesting current puzzle concerning GRBs. Numerical simulations have shown that the internal shocks' light curve reflects the activity of this inner engine. Using a simple analytic toy model we clarify the relations between the observed $ \\gamma $-rays light curve and the inner engine's activity and the dependence of the light curves on the inner engine's parameters. This simple model also explains the observed similarity between the observed distributions of pulses widths and the intervals between pulses and the correlation between the width of a pulse and the length of the preceding interval. Our analysis suggests that the variability in the wind's Lorentz factors arises due to a modulation of the mass injected into a constant energy flow.

2002-01-01

26

Anomalous fading of the TL, Blue-SL and IR-SL signals of fluorapatite  

Energy Technology Data Exchange (ETDEWEB)

The thermoluminescence (TL), blue stimulated luminescence (BSL) and infrared stimulated luminescence (IRSL) signals of fluorapatite (originating from Durango, Mexico) were measured and found to exhibit strong anomalous fading (AF). The experimentally obtained OSL and IRSL decay curves were transformed into pseudo-linear modulated (pseudo-LM) decay curves. The resulting glow-curve shaped pseudo-LM decay curves were analyzed using a deconvolution analysis, similar to the one used for the glow-curve deconvolution (GCD) of TL glow-curves. It was found that the pseudo-LM OSL and IRSL decay curves consist of two components named fast and slow, respectively, and their individual contribution was estimated. The AF of the remnant TL, BSL and IRSL as a function of the storage time was fitted using the tunneling model equations and ...

2006-08-15

27

Anomalous fading of the TL, Blue-SL and IR-SL signals of fluorapatite  

International Nuclear Information System (INIS)

The thermoluminescence (TL), blue stimulated luminescence (BSL) and infrared stimulated luminescence (IRSL) signals of fluorapatite (originating from Durango, Mexico) were measured and found to exhibit strong anomalous fading (AF). The experimentally obtained OSL and IRSL decay curves were transformed into pseudo-linear modulated (pseudo-LM) decay curves. The resulting glow-curve shaped pseudo-LM decay curves were analyzed using a deconvolution analysis, similar to the one used for the glow-curve deconvolution (GCD) of TL glow-curves. It was found that the pseudo-LM OSL and IRSL decay curves consist of two components named fast and slow, respectively, and their individual contribution was estimated. The AF of the remnant TL, BSL and IRSL as a function of the storage time was fitted using the tunneling model equations and ...

2005-07-24

28

Photon beam modelling with Pinnacle3 Treatment Planning System for a Rokus M Co-60 Machine  

International Nuclear Information System (INIS)

The basic relationships of the convolution/superposition dose calculation technique are reviewed, and a modelling technique that can be used for obtaining a satisfactory beam model for a commercially available convolution/superposition-based treatment planning system is described. A fluence energy spectrum for a Co-60 treatment machine obtained from a Monte Carlo simulation was used for modelling the fluence spectrum for a Rokus M machine. In order to achieve this model we measured the depth dose distribution and the dose profiles with a Wellhofer dosimetry system. The primary fluence was iteratively modelled by comparing the computed depth dose curves and beam profiles with the depth dose curves and crossbeam profiles measured in a water phantom. The objective of beam modelling is to build a model ...

29

Evaluation of a computer program used to estimate water characteristic curve  

Science.gov (United States)

The soil water characteristic curve, h(theta), can be used to estimate a variety of parameters in unsaturated soils. One practical application of h(theta) is its use by DRAINMOD, a drainage model that has been widely used in shallow water table regions, to determine the water table depth¿drainage v...

30

Detonating Failed Deflagration Model of Thermonuclear Supernovae II. Comparison to Observations  

CERN Document Server

We develop and demonstrate the methodology of testing multi-dimensional supernova models against observations by studying the properties of one example of the detonation from failed deflagration (DFD) explosion model of thermonuclear supernovae. Using time-dependent multi-dimensional radiative transfer calculations, we generate the synthetic broadband optical light curves, near-infrared light curves, color evolution curves, full spectral time-series, and spectropolarization of the model, as seen from various viewing angles. All model observables are critically evaluated against examples of well-observed, standard Type Ia supernovae (SNe Ia). We explore the consequences of the intrinsic model asphericity by studying the dependence of the model emission on viewing angle, and by quantifying the ...

2006-01-01

31

Galaxy rotation curves: the effect of Formula Not Shown force  

British Library Electronic Table of Contents (United Kingdom)

Using the Galaxy as an example, we study the effect of Formula Not Shown force on the rotational curves of gas and plasma in galaxies. Acceptable model for the galactic magnetic field and plausible physical parameters are used to fit the flat rotational curve for gas and plasma based on the observed baryonic (visible) matter distribution and Formula Not Shown force term in the static MHD equation of motion. We also study the effects of varied strength of the magnetic field, its pitch angle and length scale on the rotational curves. We show that Formula Not Shown force does not play an important role on the plasma dynamics in the intermediate range of distances 6?12?kpc from the centre, whilst the effect is sizable for larger r (r?15?kpc), where it is the most crucial.

2011-01-01

32

PROBABILISTIC SYSTEMS MODELING AND COST/PERFORMANCE METHODOLOGIES ...  

Science.gov (United States)

sidered as produced in one period of time for learning curve purposes. A ...... 61 FORMAT (6X,13,3XTARGET DATE 1,13,1X,A6,' NO LATER THAN',F4.0, ...

33

Endurance time is joint-specific: A modelling and meta-analysis investigation  

UK PubMed Central (United Kingdom)

Static task intensity–endurance time (ET) relationships (e.g. Rohmert's curve) were first reported decades ago. However, a comprehensive meta-analysis to compare experimentally-observed...Full Text Available

2010-01-01

34

AEROSPACE MEDICINE AND BIOLOGY - NASA Technical Reports Server  

Science.gov (United States)

Learning curve models have gained widespread acceptance as a technique for analyzing and ...... flight segment in F4 pilots p 163 A91-30966. WILSON, JOHN W . ...

35

Environmental Kuznets curve for CO2 in Canada  

British Library Electronic Table of Contents (United Kingdom)

According to the environmental Kuznets curve hypothesis, the relationship between per-capita GDP and per-capita pollutant emissions has an inverted-U shape. This implies that, past a certain point, economic growth may actually be profitable for environmental quality. Most studies on this subject are based on estimating fully parametric quadratic or cubic regression models. While this is not technically wrong, such an approach somewhat lacks flexibility since it may fail to detect the true shape of the relationship if it happens not to be of the specified form. We use semiparametric and flexible nonlinear parametric modeling methods in an attempt to provide more robust inferences. We find little evidence in favour of the environmental Kuznets curve hypothesis. Our main results could be inte...

2010-01-01

36

Evaluation of curve-fitting method for estimating the formation temperature from logging data. Chiso heiko ondo suitei shuho de aru curve fitting ho no jitsu data ni yoru kensho to hyoka  

Energy Technology Data Exchange (ETDEWEB)

The present paper explains the curve-fitting method developed as a method to estimate the geothermal equilibrium forming temperature. In the present method, that temperature is estimated by obtaining, by non-linear lest square, the model parameter to minimize the sum of remainders squared between the temperature actually measured after a lapse of certain time from the stoppage of mud water circulation and that calculated on the basis of Middleton model, mathematical model of temperature equilibrium well. In the Horner's plotting method currently in general use, temperature recovery data during a long period of about 120h are required for estimating the geothermal equilibrium forming temperature. However in the curve-fitting method, it is confirmed from the actual well data that the well recovery temperature is estimable from three logging data during 24h after the stoppage ...

1994-05-01

37

Tritium Release Behavior from Li_4SiO_4  

International Nuclear Information System (INIS)

This paper proposes a model to explain tritium release behavior of an irradiated Li_4SiO_4 sample made by Forschungszentrum Karlsruhe. The release curves were obtained in a series of experiments carried out using out-pile temperature programmed desorption techniques in the Kyoto University Reactor (KUR). Tritium release curves obtained for different purge gas compositions (N_2, N_2 + H_2, N_2 + H_2O) were compared for selection of suitable conditions to determine the apparent diffusivity of tritium in a crystal grain of Li_4SiO_4.In the model formation, some mass transfer steps in the bulk of the crystal grain and those on the surface of the grain were taken into account, which were diffusion of tritium in the grain, adsorption and desorption of water on the surface of the grain, two types of isotope exchange reactions, and water formation reaction by the addition of hydrogen to the purge ...

2004-12-01

38

Measurements of bragg curve for 75 MeV/u "1"2C ion beam and its inactivation effect on melanoma cells  

International Nuclear Information System (INIS)

Relative doses of 75 MeV/u "1"2C ion beam after passing through different thickness of degraders were measured with the double ionization chamber method. The degrader's thickness equalized to penetration depth of the beam in water and its Bragg curve were obtained. The measured Bragg curve is compared with that calculated based on a model set up by the authors. Meanwhile, the inactivation effect of the ion beam passing through different thickness of degraders on melanoma (B_1_6) cells was measured, and the corresponding survival fraction data for B_1_6 cells were acquired

1998-08-01

39

Trishear fault-propagation folding  

Energy Technology Data Exchange (ETDEWEB)

Previous models of fault-propagation folding used kink-band geometries to approximate folding in front of propagating thrusts. However, kink-band kinematics cannot replicate the curved fold surfaces and complex strain patterns innatural and experimental fault-propagation folds, which also occur in front of steeper reverse and normal faults. Fault-propagation fold hinges tighten and converge downward, forming a triangular zone of penetrative deformation focused on the tip of the propagating fault. The downward convergence of deformation in fault-propagation folds can be modeled as triangular shear zones. Trishear, here defined as distributed, strain-compatible shear in a triangular (in profile) shear zone, provides an alternate kinematic model for fault-propagation folds. Trishear is analogous to simple shear in a tabular shear zone except that area balance in a triangular shear zone requires ...

1991-06-01

40

Improved Double-Multiple Streamtube Model for the Darrieus-Type Vertical-Axis Wind Turbine.  

Science.gov (United States)

Double streamtube codes model the curved blade (Darrieus-type) vertical-axis wind turbine (VAWT) as a double actuator-disk arrangement (one disk for the upwind half of the rotor and a second disk for the downwind half) and use conservation of momentum pri...

1983-01-01

41

Release of oxytocin and prolactin in response to suckling.  

UK PubMed Central (United Kingdom)

The oxytocin and prolactin responses to suckling were measured in 10 women in early (n = 5) and established lactation (n = 5). Oxytocin was released in a pulsatile manner during suckling in all women,...Full Text Available

1983-01-22

42

Malolactic fermentation: electrogenic malate uptake and malate/lactate antiport generate metabolic energy.  

UK PubMed Central (United Kingdom)

The mechanism of metabolic energy production by malolactic fermentation in Lactococcus lactis has been investigated. In the presence of L-malate, a proton motive force composed of a membrane potential...Full Text Available

1991-10-01

43

Illthrift in Suckling Lambs Secondary to Umbilical Infections and Possible Implication of Cryptosporidiosis as a Risk Factor  

UK PubMed Central (United Kingdom)

Illthrift was observed in 20/60 lambs aged 40–45 days in a dairy sheep flock in Greece. Cryptosporidiosis had been diagnosed and successfully treated with halofuginone lactate a month earlier....Full Text Available

44

Factors governing the periodic activation of supraoptic and paraventricular neurosecretory cells during suckling in the rat.  

UK PubMed Central (United Kingdom)

1. One hundred and thirty-two antidromically identified paraventricular (PV) and supraoptic (SO) neurones were studied during milk ejection evoked by the suckling of the young, in thirty-four lactating...Full Text Available

1975-09-01

45

Effect of precalving intramammary treatment with pirlimycin in nulliparous Holstein heifers  

UK PubMed Central (United Kingdom)

A clinical trial was conducted to determine whether prepartum intramammary pirlimycin reduces the proportion of nulliparous heifers with intramammary infection (IMI) during early lactation and improves...Full Text Available

2007-10-01

46

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

UK PubMed Central (United Kingdom)

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

2004-01-01

47

Distribution of lead in lactating mice and suckling offspring with special emphasis on the mammary gland  

Energy Technology Data Exchange (ETDEWEB)

The distribution of lead in lactating mice and suckling offspring was studied with whole body autoradiography at 4 and 24 h after a single intravenous injection of {sup 203}Pb (50 mmol Pb/kg) to the dams. In the lactating mice on day 14 of lactation, the highest uptake of radioactivity at 4 h after administration was recorded in renal cortex, skeleton and liver. A high uptake was also evident in the mannary gland. At 24 h after administration, the radioactivity had decreased in most organs except in the skeleton. In the suckling pups, exposed to lead only via dams` milk for 24 h, the highest level of radioactivity was present in the intestinal mucosa and a much lower level of radioactivity was present in the skeleton. The mammary glands from mice given three daily intravenous injections of 240 {mu}mol Pb/kg were examined with X-ray microanalysis. At 4 h after the last injection, lead was found associated with casein ...

1996-01-01

48

Distribution of lead in lactating mice and suckling offspring with special emphasis on the mammary gland  

International Nuclear Information System (INIS)

The distribution of lead in lactating mice and suckling offspring was studied with whole body autoradiography at 4 and 24 h after a single intravenous injection of "2"0"3Pb (50 mmol Pb/kg) to the dams. In the lactating mice on day 14 of lactation, the highest uptake of radioactivity at 4 h after administration was recorded in renal cortex, skeleton and liver. A high uptake was also evident in the mannary gland. At 24 h after administration, the radioactivity had decreased in most organs except in the skeleton. In the suckling pups, exposed to lead only via dams' milk for 24 h, the highest level of radioactivity was present in the intestinal mucosa and a much lower level of radioactivity was present in the skeleton. The mammary glands from mice given three daily intravenous injections of 240 #mu#mol Pb/kg were examined with X-ray microanalysis. At 4 h after the last injection, lead was found associated with casein micelles ...

49

DHA Supplementation during Pregnancy and Lactation Affects Infants' Cellular but Not Humoral Immune Response  

UK PubMed Central (United Kingdom)

Background. It is currently recommended that diet of pregnant mothers contain 200–300 mg DHA/day. Aim. To determine whether DHA supplementation...Full Text Available

2011-01-01

50

Allergy and Sensitization during Childhood Associated with Prenatal and Lactational Exposure to Marine Pollutants  

UK PubMed Central (United Kingdom)

BackgroundBreast-feeding may affect the risk of developing allergy during childhood and may also cause exposure to immunotoxicants, such as polychlorinated biphenyls (PCBs), which...Full Text Available

2010-10-01

51

Acute change in the cyclic AMP content of rat mammary acini in vitro. Influence of physiological and pharmacological agents.  

UK PubMed Central (United Kingdom)

The cyclic AMP content of acini, freshly prepared from mammary tissue of lactating rats, was measured during incubation in vitro. Neither adrenergic agonists nor cyclic AMP phosphodiesterase inhibitors...Full Text Available

1985-08-15

52

Modeling of the non isothermal and non isobaric transformations kinetics. Application to the kaolinite de-hydroxylation and to the tri-uranium octo-oxide reduction by hydrogen; Modelisation de la cinetique de transformations non isothermes et (ou) non isobares. Application a la deshydroxylation de la kaolinite et a la reduction de l'octooxyde de triuranium par l'hydrogene  

Energy Technology Data Exchange (ETDEWEB)

The aim of this work is to be able to describe transformations, occurring when solids and gases are in non isothermal and non isobaric conditions, with kinetic models. A methodology has been used. Two essential processes have to be taken into account: the germination and the growth. The germs are supposed to be formed (at constant temperature and pressure) in the grains surface with a constant velocity by surface unit, (gamma), called germination surface frequency (number of germs.m{sup -2}.s{sup -1}. The growth velocity is characterized by a growth surface reactivity, (phi) (in mol.m{sup -2}.s{sup -1}). With an appropriate transformation model, it is possible to obtain the variations of (gamma) and (phi) in terms of the temperature and pressure which are then used in the calculation of the velocity in non isothermal and non isobaric conditions. In order to validate the developed method, two reactions have been studied. For the first one, the ...

2002-12-15

53

Estimates of the hydrologic impact of drilling water on core samples taken from partially saturated densely welded tuff  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this work is to determine the extent to which drill water might be expected to be imbibed by core samples taken from densely welded tuff. In a related experimental study conducted in G-Tunnel, drill water imbibition by the core samples was observed to be minimal. Calculations were carried out with the TOUGH code with the intent of corroborating the imbibition observations. Due to the absence of hydrologic data pertaining directly to G-Tunnel welded tuff, it was necessary to apply data from a similar formation. Because the moisture retention curve was not available for imbibition conditions, the drainage curve was applied to the model. The poor agreement between the observed and calculated imbibition data is attributed primarily to the inappropriateness of the drainage curve. Also significant is the value of absolute permeability (k) assumed in the model. Provided that ...

1987-09-01

54

Tritium diffusivity in crystal grain of Li{sub 2}TiO{sub 3} and tritium release behavior under several purge gas conditions  

Energy Technology Data Exchange (ETDEWEB)

It has been reported by the present authors that behavior of tritium release from solid breeder grain is consisted of diffusion in grain, tritium transfer at surface layer and surface reactions on grain surface such as adsorption or isotope exchange reactions. Tritium release curves estimated using the tritium release model gave good agreement with observed tritium release curves from Li{sub 4}SiO{sub 4}, Li{sub 2}ZrO{sub 3} or LiAlO{sub 2}. Tritium release behavior from Li{sub 2}TiO{sub 3} under humid purge gas, dry purge gas and dry purge gas with hydrogen conditions is discussed in this study, tritium release curves using the release model that we proposed previously give a good agreements with experimental tritium release curves. Tritium effective diffusivity in the crystal grain of Li{sub 2}TiO{sub 3} is also estimated in this study using a ...

2008-05-15

55

Tritium diffusivity in crystal grain of Li_2TiO_3 and tritium release behavior under several purge gas conditions  

International Nuclear Information System (INIS)

It has been reported by the present authors that behavior of tritium release from solid breeder grain is consisted of diffusion in grain, tritium transfer at surface layer and surface reactions on grain surface such as adsorption or isotope exchange reactions. Tritium release curves estimated using the tritium release model gave good agreement with observed tritium release curves from Li_4SiO_4, Li_2ZrO_3 or LiAlO_2. Tritium release behavior from Li_2TiO_3 under humid purge gas, dry purge gas and dry purge gas with hydrogen conditions is discussed in this study, tritium release curves using the release model that we proposed previously give a good agreements with experimental tritium release curves. Tritium effective diffusivity in the crystal grain of Li_2TiO_3 is also estimated in this study using a curve-fitting method applied to the ...

2008-05-01

56

The effect of temperature on the grain growth of nanocrystalline metals and its simulation by molecular dynamics method  

British Library Electronic Table of Contents (United Kingdom)

In this study, the thermodynamic stability of the grain boundaries and the grain growth of nanocrystalline Palladium (Pd) at various temperatures were investigated. For this purpose, the Gibbs free energy curves of grain boundaries were plotted in terms of the excess volume by the use of the equation of state (EOS) and Song's thermodynamic models. The results showed that, according to the prediction of these models, the nanocrystalline growth in metals was stopped at the grain sizes less than the critical grain size. Also, the results of the temperature variations and its effect on the Gibbs free energy curves showed that by the increase of the temperature, the possibility for the stoppage of grain growth is facilitated and the critical grain size is increased. To investigate the validity ...

2012-01-01

57

Effective Parameters on the Stress-Strain Curve of Nylon 66/Clay Nanocomposite Using FEM  

British Library Electronic Table of Contents (United Kingdom)

Abstract:- In recent years, the study of polymer/clay nanocomposites has attracted major research and commercial interests due to their superior mechanical and thermal properties to those of the neat polymers. Numerical modelling is an advantageous approach to understand the material behaviour. In this work a symmetric two dimensional finite element model is developed to simulate the fully exfoliated Polymer/Clay nanocomposite behaviour and evaluate its- before stress stress-strain curve. The Nylon 66/Clay in this study has a nonlinear elastic behaviour. The influence of volume fraction and aspect ratio of clay platelet (defined as the ratio of the particle length to the particle thickness) on the tensile behaviour of exfoliated Nylon 66/clay nanocomposite is investigated with the aid of n...

2011-01-01

58

Combined inverse modeling approach and load duration curve method for variable nitrogen total maximum daily load development in an agricultural watershed  

British Library Electronic Table of Contents (United Kingdom)

Purpose Nonpoint sources (NPS) pollution has been an important cause for water quality impairment worldwide. To take the temporal variations of both NPS pollution and in-stream attenuation into consideration, an inverse modeling approach and the load duration curve (LDC) method were combined for variable nutrient total maximum daily load (TMDL) development. Methods Water quality and hydrological parameters were monitored monthly along the ChangLe River system in 2004?2008. The catchment NPS export load (EL) and TMDL for total nitrogen (TN) were estimated by the inverse format of an existing stream nutrient transport equation. The LDC method was used to describe the variability of EL, TMDL, requiring load (RLR) and percent (the ratio between the RLR and the EL, RPR) reduction, and then to s...

2011-01-01

59

Adsorption rate of phenol from aqueous solution onto organobentonite: Surface diffusion and kinetic models.  

Science.gov (United States)

The concentration decay curves for the adsorption of phenol on organobentonite were obtained in an agitated tank batch adsorber. The experimental adsorption rate data were interpreted with diffusional models as well as first-order, second-order and Langmuir kinetic models. The surface diffusion model adjusted the data quite well, revealing that the overall rate of adsorption was controlled by surface diffusion. Furthermore, the surface diffusion coefficient increased raising the mass of phenol adsorbed at equilibrium and was independent of the particle diameter in the range 0.042-0.0126cm. It was demonstrated that the overall rate of adsorption was essentially not affected by the external mass transfer. The second-order and the Langmuir kinetic models fitted the experimental data quite well; however, the kinetic constants of both models varied without any ...

2011-08-22

60

A Bragg curve ionization chamber for acceleration mass spectrometry  

CERN Document Server

A Bragg curve ionization chamber for acceleration mass spectrometry

1985-01-01

61

Topological expansion of beta-ensemble model and quantum algebraic geometry in the sectorwise approach  

CERN Document Server

We solve the loop equations of the $\\beta$-ensemble model analogously to the solution found for the Hermitian matrices $\\beta=1$. For \\beta=1$, the solution was expressed using the algebraic spectral curve of equation $y^2=U(x)$. For arbitrary $\\beta$, the spectral curve converts into a Schr\\"odinger equation $((\\hbar\\partial)^2-U(x))\\psi(x)=0$ with $\\hbar\\propto (\\sqrt\\beta-1/\\sqrt\\beta)/N$. This paper is similar to the sister paper~I, in particular, all the main ingredients specific for the algebraic solution of the problem remain the same, but here we present the second approach to finding a solution of loop equations using sectorwise definition of resolvents. Being technically more involved, it allows defining consistently the B-cycle structure of the obtained quantum algebraic curve (a D-module of the form $y^2-U(x)$, where $[y,x]=\\hbar$) and to construct explicitly the correlation ...

2010-01-01

62

Methodological study of hemodynamic analysis of lung mass by contrast enhanced dynamic CT  

Energy Technology Data Exchange (ETDEWEB)

We investigated a method of analyzing the hemodynamics of the lung mass by contrast enhanced dynamic computed tomography (dynamic CT) to determine the difference in vascular supply between the pulmonary artery and bronchial artery using an experimental model. Our experimental model consisted of two injectors connected to two tubes, representing the pulmonary artery and bronchial artery, which were further connected to a chamber representing the lung mass. Following infusion of contrast medium into each tube with some delay time, dynamic CT scans were performed to obtain time density curves of the two tubes and the chamber. Using the time-density curve of contrast passage, flow rates from the two tubes into the chamber were calculated by the curve fitting method. Calculated values correlated well with the adopted flow rates of fluid from the injectors (r=0.893) in the experiment. The ...

1996-06-01

63

Methodological study of hemodynamic analysis of lung mass by contrast enhanced dynamic CT  

International Nuclear Information System (INIS)

We investigated a method of analyzing the hemodynamics of the lung mass by contrast enhanced dynamic computed tomography (dynamic CT) to determine the difference in vascular supply between the pulmonary artery and bronchial artery using an experimental model. Our experimental model consisted of two injectors connected to two tubes, representing the pulmonary artery and bronchial artery, which were further connected to a chamber representing the lung mass. Following infusion of contrast medium into each tube with some delay time, dynamic CT scans were performed to obtain time density curves of the two tubes and the chamber. Using the time-density curve of contrast passage, flow rates from the two tubes into the chamber were calculated by the curve fitting method. Calculated values correlated well with the adopted flow rates of fluid from the injectors (r=0.893) in the experiment. The ...

64

A phenomenologically based computer model to predict soot and NO{sub x} emission in a direct injection diesel engine  

Energy Technology Data Exchange (ETDEWEB)

A phenomenological model based on the multizone method is described. The model requires a relatively low amount of central processing unit (CPU) time and memory for each run and, consequently, is useful for parameter studies. The flame morphology predicted by the model is compared to that recently uncovered in experimental studies. As a demonstration of its utility, the model is used to study the effect of the oxygen content in intake air on the emission of particulate matter (PM) and NO{sub x} from a direct injection diesel engine. A parametric study reveals that while oxygen-enriched intake air is useful for reducing PM, the reduction comes with a large increase in NO{sub x} emission. The PM-NO{sub x} trade-off curve for the oxygenated intake air is worse than that for the baseline air case. (Author)

2001-07-30

65

A Cross-National Analysis of How Economic Inequality Predicts Biodiversity Loss  

British Library Electronic Table of Contents (United Kingdom)

Abstract: We used socioeconomic models that included economic inequality to predict biodiversity loss, measured as the proportion of threatened plant and vertebrate species, across 50 countries. Our main goal was to evaluate whether economic inequality, measured as the Gini index of income distribution, improved the explanatory power of our statistical models. We compared four models that included the following: only population density, economic footprint (i.e., the size of the economy relative to the country area), economic footprint and income inequality (Gini index), and an index of environmental governance. We also tested the environmental Kuznets curve hypothesis, but it was not supported by the data. Statistical comparisons of the models revealed that the model including both economi...

2009-01-01

66

Rotation in string cosmology  

Energy Technology Data Exchange (ETDEWEB)

We describe exact cosmological solutions with rotation and expansion in the low-energy effective string theory. These models are spatially homogeneous (closed Bianchi type IX) and they belong to the family of shear-free metrics which are causal (no closed timelike curves are allowed), admit no parallax effects and do not disturb the isotropy of the background radiation. The dilaton and the axion fields are nontrivial, in general, and we consider both cases with and without the central charge (effective cosmological constant)

2003-03-21

67

Rotation in string cosmology  

International Nuclear Information System (INIS)

We describe exact cosmological solutions with rotation and expansion in the low-energy effective string theory. These models are spatially homogeneous (closed Bianchi type IX) and they belong to the family of shear-free metrics which are causal (no closed timelike curves are allowed), admit no parallax effects and do not disturb the isotropy of the background radiation. The dilaton and the axion fields are nontrivial, in general, and we consider both cases with and without the central charge (effective cosmological constant).

2003-03-21

68

Non-linearity of pre-dose response and its effects on TL dating  

Energy Technology Data Exchange (ETDEWEB)

Analytical expressions for thermoluminescence (TL) dating based on the modified Zimmerman model were derived. The non-linear behaviour of TL sensitivity is reexamined and is found to be due to electron capturing competitions in both test-dose excitation and the readout stages. A curve fitting method is proposed to determine the paleodose for the additive dose dating method. The multiple activation technique is also investigated, from which the paleodose should be regarded as an upper limit.

2009-03-15

69

Non-linearity of pre-dose response and its effects on TL dating  

International Nuclear Information System (INIS)

Analytical expressions for thermoluminescence (TL) dating based on the modified Zimmerman model were derived. The non-linear behaviour of TL sensitivity is reexamined and is found to be due to electron capturing competitions in both test-dose excitation and the readout stages. A curve fitting method is proposed to determine the paleodose for the additive dose dating method. The multiple activation technique is also investigated, from which the paleodose should be regarded as an upper limit.

2009-03-01

70

Indirect evidence for the existence of tachyons; a unified approach to the pion #-># muon #-># electron conversion problem  

International Nuclear Information System (INIS)

Using the experimentally determined cutoff energies of the muon-electron and the pion-electron conversion curves in a tachyon-bradyon model of the electron and the muon, the magnetic moments of these particles have been derived and found to be the Bohr magnetons identically. The tachyons, being bound to the bradyons and unable to drop below the speed of light, cause the bradyons to revolve in an orbit. It is this orbital motion of the charged bradyons that generates the magnetic moments.

71

Estimation of the parameter covariance matrix for aone-compartment cardiac perfusion model estimated from a dynamic sequencereconstructed using map iterative reconstruction algorithms  

Energy Technology Data Exchange (ETDEWEB)

In dynamic cardiac SPECT estimates of kinetic parameters ofa one-compartment perfusion model are usually obtained in a two stepprocess: 1) first a MAP iterative algorithm, which properly models thePoisson statistics and the physics of the data acquisition, reconstructsa sequence of dynamic reconstructions, 2) then kinetic parameters areestimated from time activity curves generated from the dynamicreconstructions. This paper provides a method for calculating thecovariance matrix of the kinetic parameters, which are determined usingweighted least squares fitting that incorporates the estimated varianceand covariance of the dynamic reconstructions. For each transaxial slicesets of sequential tomographic projections are reconstructed into asequence of transaxial reconstructions usingfor each reconstruction inthe time sequence an iterative MAP reconstruction to calculate themaximum a priori reconstructed estimate. Time-activity ...

2004-01-01

72

Estimation of skin friction of pile shaft in remodeled clay  

Energy Technology Data Exchange (ETDEWEB)

Testing results obtained from simple shear and direct shear tests were conducted for investigating the frictional properties between steel pile shaft and silty clay in this paper. By using the analyzed results of these tests, a hyperbolic curve fitting method for estimating skin friction of pile shaft was proposed in which was verified by its application on the results of undrained uplift triaxial model pile tests.

1994-12-31

73

Atomic interactions of charged particles with matter  

Energy Technology Data Exchange (ETDEWEB)

Ideas about the interactions of charged particles with matter are discussed. First, some experimental information is presented. Concepts related to collision cross sections and the Bethe model for them are given. The stopping power is derived and applied to the discussion of depth dose functions ('Bragg curves'). Some details of the energy loss in microscopic volumes are discussed.

1993-04-01

74

Supercritical fluid extraction from dried banana peel (Musa spp., genomic group AAB): Extraction yield, mathematical modeling, economical analysis and phase equilibria  

British Library Electronic Table of Contents (United Kingdom)

Supercritical fluid extraction from dried banana peel (Musa spp., subgroup Prata, genomic group AAB, popularly known in Brazil as Enxerto) was studied. The aspects investigated were: overall extraction curve (OEC), mass transfer modeling of the yield curves, economical analysis of the process and phase equilibrium data for the pseudo-ternary system of banana peel extract, carbon dioxide and ethanol. The extraction operating conditions evaluated were: pressure ranging from 100bar to 300bar, temperature from 40 to 50^oC and constant solvent flow rate of 5.0gCO2/min. Experimental extraction data were correlated using three kinetic models based on mass transfer equations (logistic, diffusion and Esquivel models). Phase equilibrium measurements were performed using pressure from 64.9bar to 239....

2010-01-01

75

Flow behaviour and microstructure of the heat-resistant steels X20CrMoV12.1 and X5NiCrTiAl32.20 (alloy 800)  

Energy Technology Data Exchange (ETDEWEB)

Flow-curve characteristics of the heat-resistant steels X 20 CrMoV 12.1 and alloy 800 (X5NiCrTiAl32.20) were measured by tensile and compression tests at temperatures between room temperature and 800 C and strain rates {epsilon}{<=}10 s{sup -1} in connection with microstructure investigations (dislocation content, carbide precipitation) by TEM and X-ray diffraction analysis (XDA). Modelling the deformation behaviour of the steels in terms of the microstructure development indicates that it cannot be explained in a simple manner. The flow curves {sigma}={sigma}({epsilon}, {epsilon}, T) lie, in general, between those predicted by the Kocks-Mecking-Estrin model and a modified (i.e. two-parameter) Roberts model. Because of the less complicated nature of the deformation process the correspondence of experiment and modelling is more satisfying in the case of the ...

1999-10-01

76

A dynamic approach to the Environmental Kuznets Curve hypothesis  

Energy Technology Data Exchange (ETDEWEB)

The Environmental Kuznets Curve (EKC) hypothesis states that pollution levels increase as a country develops, but begin to decrease as rising incomes pass beyond a turning point. In EKC analyses, the relationship between environmental degradation and income is usually expressed as a quadratic function with the turning point occurring at a maximum pollution level. Other explanatory variables have been included in these models, but income regularly has had the most significant effect on indicators of environmental quality. One variable consistently omitted in these relationships is the price of energy. This paper analyzes previous models to illustrate the importance of prices in these models and then includes prices in an econometric EKC framework testing energy/income and CO{sub 2}/income relationships. These long-run price/income models find that income is no longer the most ...

1999-02-01

77

A dynamic approach to the Environmental Kuznets Curve hypothesis  

International Nuclear Information System (INIS)

The Environmental Kuznets Curve (EKC) hypothesis states that pollution levels increase as a country develops, but begin to decrease as rising incomes pass beyond a turning point. In EKC analyses, the relationship between environmental degradation and income is usually expressed as a quadratic function with the turning point occurring at a maximum pollution level. Other explanatory variables have been included in these models, but income regularly has had the most significant effect on indicators of environmental quality. One variable consistently omitted in these relationships is the price of energy. This paper analyzes previous models to illustrate the importance of prices in these models and then includes prices in an econometric EKC framework testing energy/income and CO_2/income relationships. These long-run price/income models find that income is no longer the most relevant ...

1999-02-01

78

Study of azeotropic mixtures with the advanced distillation curve approach  

British Library Electronic Table of Contents (United Kingdom)

Classical methods for the study of complex fluid phase behavior include static and dynamic equilibrium cells that usually require vapor and liquid recirculation. These are sophisticated, costly apparatus that require highly trained operators, usually months of labor-intensive work per mixture, and the data analysis is also rather complex. Simpler approaches to the fundamental study of azeotropes are highly desirable, even if they provide only selected cuts through the phase diagram. Recently, we introduced an advanced distillation curve measurement method featuring: (1) a composition explicit data channel for each distillate fraction (for both qualitative and quantitative analysis), (2) temperature measurements that are true thermodynamic state points that can be modeled with an equation o...

2009-01-01

79

Prediction and Preliminary Standardization of Fire Debris Constituents with the Advanced Distillation Curve Method*  

British Library Electronic Table of Contents (United Kingdom)

Abstract: The recent National Academy of Sciences report on forensic sciences states that the study of fire patterns and debris in arson fires is in need of additional work and eventual standardization. We discuss a recently introduced method that can provide predicted evaporation patterns for ignitable liquids as a function of temperature. The method is a complex fluid analysis protocol, the advanced distillation curve approach, featuring a composition explicit data channel for each distillate fraction (for qualitative, quantitative, and trace analysis), low uncertainty temperature measurements that are thermodynamic state points that can be modeled with an equation of state, consistency with a century of historical data, and an assessment of the energy content of each distillate fraction...

2011-01-01

80

Advanced Distillation Curve Measurement with a Model Predictive Temperature Controller  

British Library Electronic Table of Contents (United Kingdom)

In previous work, several significant improvements in the measurement of distillation curves for complex fluids were introduced. The modifications to the classical measurement provide for (1) temperature and volume measurement(s) of low uncertainty, and most important, (2) a composition-explicit data channel in addition to the usual temperature?volume relationship. This latter modification is achieved with a new sampling approach that allows precise qualitative as well as quantitative analyses of each fraction, on the fly. In the new approach, the distillation temperature is measured in two locations. The temperature is measured in the usual location, at the bottom of the take-off in the distillation head, but it is also measured directly in the fluid. We have further modified our developm...

2006-01-01

81

Thermodynamic Model of Aluminum Combustion in SDF Explosions  

Energy Technology Data Exchange (ETDEWEB)

Thermodynamic states encountered during combustion of Aluminum powder in Shock-Dispersed-Fuel (SDF) explosions were analyzed with the Cheetah code. Results are displayed in the Le Chatelier diagram: the locus of states of specific internal energy versus temperature. Accuracy of the results was confirmed by comparing the fuel and products curves with the heats of detonation and combustion, and species composition as measured in bomb calorimeter experiments. Results were fit with analytic functions u = f(T) suitable for specifying the thermodynamic properties required for gas-dynamic models of combustion in explosions.

2006-06-19

82

Some reflections on the network power plant interaction  

International Nuclear Information System (INIS)

The layout of the network with its frequency and transmission power control shows how the time behaviour of power plants and consumers determines the frequency curve during sudden power disturbances. As for switching processes in the network for the turbine, network operation entails loads due to shock-like disturbance functions to which one should not normally respond by switching off. The interception controllers are therefore adjusted via a simulation model by which the vibrations of the turbine rotor can be modelled in real time under different network loads. (GL).

1978-11-24

83

Optimal generation planning for a thermal system with pumped-storage based on analytical production costing model  

Energy Technology Data Exchange (ETDEWEB)

This paper presents a new algorithm for the optimal long-range generation planning for a thermal system with pumped-storage plants. The algorithm is based upon the analytical production costing model developed under the assumption of Gaussian probabilistic distribution of random load fluctuations and plant outages. The optimization problem consists of the master problem to determine the annual investment, and the pumped-storage subproblem to determine the optimal pumped-storage operation. The master problem is formulated as a Hamiltonian minimization problem, and the pumped-storage subproblem is solved using the concept of peak-shaving operation on the original load curve.

1986-01-01

84

Optimal generation planning for a thermal system with pumped-storage based on analytical production costing model  

Energy Technology Data Exchange (ETDEWEB)

This paper presents a new algorithm for the optimal long-range generation planning for a thermal system with pumped-storage plants. The algorithm is based upon the analytical production costing model developed under the assumption of Gaussian probabilistic distribution of random load fluctuations and plant outages. The optimization problem consists of the master problem to determine the annual investment, and the pumped-storage subproblem to determine the optimal pumped-storage operation. The master problem is formulated as a Hamiltonian minimization problem, and the pumped-storage subproblem is solved using the concept of peak-shaving operation on the original load curve.

1987-05-01

85

Lifetime and fatigue limit prediction for components of high strength steels; Vorhersage der Lebensdauer und Dauerfestigkeit von Bauteilen aus hochfesten, durchhaertenden Staehlen  

Energy Technology Data Exchange (ETDEWEB)

Smooth and notched specimens of the bearing steel 100Cr6 (SAE 52100) in a bainitic condition were used to determine the S-N-curves under tensile, torsional and combined in- and out-of-phase loading. In the area of high-cycle-fatigue, crack initiation was most likely caused by inclusions like Titanium Carbonitrides or Aluminium Oxides. A model was developed to describe the influence of the magnitude of these inclusions on the lifetime. A weakest link model, using the statistical distribution of inclusions and surface flaws, was used to describe the fatigue limit. (orig.)

2000-07-01

86

Formation of charge and energy distribution of heavy ions in substance according to diffusion model  

International Nuclear Information System (INIS)

The formation of the ions charge and energy distributions of the ions slowed down or randomly changing their charge in the collisions with the medium particles are studied. The effect of the ions dispersion by the charge on the Bragg curve form is investigated. The proposed diffusion approximation for the heavy ions kinetic equation makes it possible to determine simply the parameters of the ions distribution by charge and energy on the whole way of the ions motion. The relation between the ions charge distribution characteristics and the cross sections of the ionization-recombination processes is indicated. The ions distributions, calculated in the proposed analytical model, are compared with the results of the numerical calculations. Good agreement between the analytical, numerical and experimental results is obtained

2003-11-01

87

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

Energy Technology Data Exchange (ETDEWEB)

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

1992-12-31

88

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

International Nuclear Information System (INIS)

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

1991-08-25

89

A Permeability Model for Coal and Other Fractured, Sorptive-Elastic Media  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the derivation of a new equation that can be used to model the permeability behavior of a fractured, sorptive-elastic media, such as coal, under variable stress conditions commonly used during measurement of permeability data in the laboratory. The model is derived for cubic geometry under biaxial or hydrostatic confining pressures. The model is also designed to handle changes in permeability caused by adsorption and desorption of gases from the matrix blocks. The model equations can be used to calculate permeability changes caused by the production of methane from coal as well as the injection of gases, such as carbon dioxide, for sequestration in coal. Sensitivity analysis of the model found that each of the input variables can have a significant impact on the outcome of the permeability forecast as a function of changing pore pressure; thus, accurate input ...

2006-10-01

90

The Effect of Lunar-like Satellites on the Orbital Infrared Light Curves of Earth-analog Planets  

CERN Document Server

We investigate the influence of lunar-like satellites on the infrared orbital light curves of Earth-analog extra-solar planets. Such light curves will be obtained by NASA's Terrestrial Planet Finder (TPF) and ESA's Darwin missions as a consequence of repeat observations to confirm the companion status of a putative planet. We use an energy balance model to calculate disk-averaged infrared (bolometric) fluxes from planet-satellite systems over a full orbital period (one year). The satellites are assumed to lack an atmosphere, have a low thermal inertia like that of the Moon and span a range of plausible radii. The planets are assumed to have thermal and orbital properties that mimic those of the Earth while their obliquities and orbital longitudes of inferior conjunction remain free parameters. Even if the gross thermal properties of the planet can be independently constrained (e.g. via spectroscopy or visible-wavelength ...

2008-01-01

91

Scattered Light from Close-in Extrasolar Planets: Prospects of Detection with the MOST Satellite  

CERN Document Server

The ultra-precise photometric space satellite MOST (Microvariability and Oscillations of STars) will provide the first opportunity to measure the albedos and scattered light curves from known short-period extrasolar planets. Due to the changing phases of an extrasolar planet as it orbits its parent star, the combined light of the planet-star system will vary on the order of tens of micromagnitudes. The amplitude and shape of the resulting light curve is sensitive to the planet's radius and orbital inclination, as well as the composition and size distribution of the scattering particles in the planet's atmosphere. To predict the capabilities of MOST and other planned space missions, we have constructed a series of models of such light curves, improving upon earlier work by incorporating more realistic details such as: limb darkening of the star, intrinsic granulation noise in the star itself, tidal ...

2003-01-01

92

Reaction of solid sorbents with hydrogen chloride gas at high temperature in a fixed-bed reactor  

Energy Technology Data Exchange (ETDEWEB)

The gas-solid reaction and breakthrough curves in the fixed-bed reactor are of great importance, and being influenced by a number of factors makes the prediction of these factors a difficult problem. In this study, the reaction rate between solid sorbents and hydrogen chloride gas at high temperature was first investigated. On the basis of a fixed-bed reactor, the experimental results were analyzed by the shrinking core model of diffusion and surface chemical reaction control. The results showed that reaction rates of two sorbents with hydrogen chloride gas were controlled by the combination of the surface chemical reaction and diffusion of product layers, and the reaction rates nearly keep constant within 15 h of the initial reaction period and then decrease gradually. The results of the breakthrough curves show that solid sorbents in the fixed-bed reactor are capable of reducing the HCl level to near-zero levels at ...

2005-12-01

93

Quantification of antibiotic drug potency by a two-compartment radioassay of bacterial growth  

Energy Technology Data Exchange (ETDEWEB)

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 ...

1990-06-01

94

Evaluation of Mechanical Properties and Microstructure in Ion-Irradiated Surface Layer  

Science.gov (United States)

Target vessel materials used in spallation neutron source will be exposed to proton and neutron irradiation and mercury immersion environments. In order to evaluate the surface degradation of the vessel candidate materials due to such environment, the triple-ion beam irradiation taking the spallation reaction into account and mercury immersion tests were carried out. Mechanical properties of the gradient surface layer were evaluated by the inverse analysis with multi-layer model that considers distribution of surface characteristic was applied to the load and depth curves measured by using the instrumented indentation machine. Transmission electron microscopic observations were performed to evaluate the changes of microstructure in irradiated surface layer using focused ion-beam cut micro-specimen. The mechanical properties distributions in the surface layer were evaluated quantitatively and the changes in microstructures were correspondent to ...

2005-01-01

95

Proximity effect correction of a laser lithography process for photomask fabrication  

Energy Technology Data Exchange (ETDEWEB)

We report on the improvement of Critical Dimension (CD) linearity on a photomask by applying the concept of process proximity correction to a laser lithographic process used for fabrication of photomasks. Rule-based Laser Process proximity Correction (LPC) was performed using an automated optical proximity correction tool and we obtained dramatic improvement of CD linearity on a photomask. A study on model-based LPC was executed using a two-Gaussian kernel function and we extracted model parameters for the laser lithographic process by fitting the model-predicted CD linearity data with measured ones. Model-predicted bias values of isolated space (I/S), Arrayed Contact (A/C) and Isolated Contact (I/C) were in good agreement with those obtained by the nonlinear curve-fitting method used for the rule-based LPC.

2004-07-01

96

Proximity effect correction of a laser lithography process for photomask fabrication  

International Nuclear Information System (INIS)

We report on the improvement of Critical Dimension (CD) linearity on a photomask by applying the concept of process proximity correction to a laser lithographic process used for fabrication of photomasks. Rule-based Laser Process proximity Correction (LPC) was performed using an automated optical proximity correction tool and we obtained dramatic improvement of CD linearity on a photomask. A study on model-based LPC was executed using a two-Gaussian kernel function and we extracted model parameters for the laser lithographic process by fitting the model-predicted CD linearity data with measured ones. Model-predicted bias values of isolated space (I/S), Arrayed Contact (A/C) and Isolated Contact (I/C) were in good agreement with those obtained by the nonlinear curve-fitting method used for the rule-based LPC.

2004-11-04

97

On the neutrino ball model  

Energy Technology Data Exchange (ETDEWEB)

It is suggested that the model of a neutrino ball described in terms of the standard model extended by adding right-handed neutrinos and the Majorana scalar field can be presented in order to explain a body of weak interacting neutrinos. Neutrino interaction with the scalar Majorana field violates the lepton number and produces the mass splitting of neutrino due to the sea-saw mechanism. In this model a neutrino ball is an object which appears as a result of a first order cosmological phase transition. It can be regarded as a ball filled with Dirac neutrinos and can be treated as a remnant of the phase transition with unbroken global lepton symmetry. In this paper we study the macroscopic parameters of such a configuration. In the result the mass-radius curve M(R) for this object is obtained. (orig.).

1995-07-01

98

Mathematical model of heat transfer for bloom continuous casting  

British Library Electronic Table of Contents (United Kingdom)

A mathematical model for heat transfer during solidification in continuous casting of automobile steel, was established on researching under the influence of the solidifying process of bloom quality of CCM in the EAF steelmaking shop, at Shijiazhuang Iron and Steel Co. Ltd. Several steel grades were chosen to research, such as, 40Cr and 42CrMo. According to the results of the high temperature mechanical property tests of blooms, the respective temperature curves for controlling the solidification of different steels were acquired, and a simulating software was developed. The model was verified using two methods, which were bloom pinshooting and surface strand temperature measuring experiments. The model provided references for research on the solidifying process and optimization of a secon...

2008-01-01

99

Improved double-multiple streamtube model for the Darrieus-type vertical axis wind turbine  

Science.gov (United States)

Double streamtube codes model the curved blade (Darrieus-type) vertical axis wind turbine (VAWT) as a double actuator fish arrangement (one half) and use conservation of momentum principles to determine the forces acting on the turbine blades and the turbine performance. Sandia National Laboratories developed a double multiple streamtube model for the VAWT which incorporates the effects of the incident wind boundary layer, nonuniform velocity between the upwind and downwind sections of the rotor, dynamic stall effects and local blade Reynolds number variations. The theory underlying this VAWT model is described, as well as the code capabilities. Code results are compared with experimental data from two VAWT's and with the results from another double multiple streamtube and a vortex filament code. The effects of neglecting dynamic stall and horizontal wind velocity distribution are also illustrated.

1983-01-01

100

Gravitational Lens Modeling with Genetic Algorithms and Particle Swarm Optimizers  

CERN Document Server

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 ...

2011-01-01

101

Degradation of a poly(ester urethane) elastomer. IV. Sorption and diffusion of water in PBX 9501 and its components  

British Library Electronic Table of Contents (United Kingdom)

In preparation for studying the hydrolytic degradation of Estane 5703 in the plastic-bonded explosive PBX 9501, the sorption (solubility) and diffusion of water in PBX 9501 and each of its components are studied experimentally and modeled theoretically. Experiments are reported that measure the weight gain or loss due to a change in the relative humidity (RH). For all of the components, the equilibrium amount of water sorbed per gram of sample is linear in the RH at low relative humidities but curves upwards at higher relative humidities. This behavior is modeled with a water cluster model. Diffusion coefficients are determined by modeling the time dependence of the water concentrations assuming Fickian diffusion, and that fits the data for some of the materials. However, all the samples t...

2007-01-01

102

Comparative study of extraction methods for solar cell model parameters  

Energy Technology Data Exchange (ETDEWEB)

A comparative study of three methods for extracting solar cell parameters of the single-diode lumped-circuit model is presented, using experimental characteristics collected from two silicon cells over a range of illuminations and temperatures. The results show that the curve-fitting method can often give erroneous parameter values. The 5-point methods are found to be reliable and accurate in situations where the model is a good approximation of cell performance. The analytical 5-point method, however, has the added advantage of simplicity. It is also found that for the cell measured, the single diode model is valid at illuminations above one-half AM1 but gives non-physical parameter values at lower illumination.

1986-03-01

103

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

Energy Technology Data Exchange (ETDEWEB)

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

1980-01-01

104

The relationship between income and environment in Turkey: Is there an environmental Kuznets curve?  

Energy Technology Data Exchange (ETDEWEB)

In this study, we investigate the relationship between income and environmental quality for Turkey at two levels. First, the relationship between the CO{sub 2} emissions and per capita income is examined by the help of a time series model using cointegration techniques. In the second stage, the relationship between income and air pollution is investigated by using PM{sub 10} and SO{sub 2} measurements in Turkish provinces. In this part of the study panel data estimation techniques are utilized. The time series model covers 1968-2003, and the panel data model covers 1992-2001 including observations from 58 provinces. A monotonically increasing relationship between CO{sub 2} and income is found in the long-run according to time series analysis. On the other hand, panel data analysis indicates an N-shape relationship for SO{sub 2} and PM{sub 10} emissions. Therefore, the results of our time series and panel data analyses do ...

2009-03-15

105

The relationship between income and environment in Turkey: Is there an environmental Kuznets curve?  

International Nuclear Information System (INIS)

In this study, we investigate the relationship between income and environmental quality for Turkey at two levels. First, the relationship between the CO2 emissions and per capita income is examined by the help of a time series model using cointegration techniques. In the second stage, the relationship between income and air pollution is investigated by using PM10 and SO2 measurements in Turkish provinces. In this part of the study panel data estimation techniques are utilized. The time series model covers 1968-2003, and the panel data model covers 1992-2001 including observations from 58 provinces. A monotonically increasing relationship between CO2 and income is found in the long-run according to time series analysis. On the other hand, panel data analysis indicates an N-shape relationship for SO2 and PM10 emissions. Therefore, the results of our time series and panel data analyses do not support the Environmental Kuznets ...

2009-03-01

106

The relationship between income and environment in Turkey. Is there an environmental Kuznets curve?  

Energy Technology Data Exchange (ETDEWEB)

In this study, we investigate the relationship between income and environmental quality for Turkey at two levels. First, the relationship between the CO{sub 2} emissions and per capita income is examined by the help of a time series model using cointegration techniques. In the second stage, the relationship between income and air pollution is investigated by using PM{sub 10} and SO{sub 2} measurements in Turkish provinces. In this part of the study panel data estimation techniques are utilized. The time series model covers 1968-2003, and the panel data model covers 1992-2001 including observations from 58 provinces. A monotonically increasing relationship between CO{sub 2} and income is found in the long-run according to time series analysis. On the other hand, panel data analysis indicates an N-shape relationship for SO{sub 2} and PM{sub 10} emissions. Therefore, the results of our time series and panel data analyses do ...

2009-03-15

107

The effect of meal size on gastric evacuation in whiting  

DEFF Research Database (Denmark)

Gastric evacuation experiments were performed on whiting Merlangius merlangus fed discrete meals of different sizes. Herring Clupea harengus, sandeel Ammodytes tobianus, common goby Pomatoschistus microps, and brown shrimp Crangon crangon were tested as prey. A simple power model to describe gastric evacuation was evaluated and compared with a power model expanded as a function of meal size. The model parameters were estimated by means of nonlinear least squares. When all meal sizes were included the estimates of the power (curvature) parameter in the expanded model were within the range 0.36-0.77 for the different prey. The power estimates in the simple model were generally close to 0.5. The exception was crustacean prey, which gave a higher value. In the simple model the power estimate represents a compromise between the curvatures of the ...

1998-01-01

108

Improved double-multiple streamtube model for the Darrieus-type vertical-axis wind turbine  

Energy Technology Data Exchange (ETDEWEB)

Double streamtube codes model the curved blade (Darrieus-type) vertical-axis wind turbine (VAWT) as a double actuator-disk arrangement (one disk for the upwind half of the rotor and a second disk for the downwind half) and use conservation of momentum principles to determine the forces acting on the turbine blades and the turbine performance. These models differentiate between the upwind and downwind sections of the rotor and are capable of determining blade loading more accurately than the widely-used single-actuator-disk streamtube models. Additional accuracy may be obtained by representing the turbine as a collection of several streamtubes, each of which is modeled as a double actuator disk. This is referred to as the double-multiple-streamtube model. Sandia National Laboratories has developed a double-multiple streamtube model for the ...

1983-01-01

109

Cell turnover and gene activities in sheep mammary glands prior to lambing to involution  

British Library Electronic Table of Contents (United Kingdom)

Mammary glands are special tissue characterized by proliferation of the epithelium, during puberty and pregnancy and by programmed cell death, during involution. In this study, apoptosis was identified by TUNEL staining and then related to cell proliferation, as determined by Ki-67 staining. The apoptotic index was at its highest at 8 days of involution, whereas the proliferation index was at its highest during lactation. Caspase-3 was immunolocalised only in mast cells and along the basal membrane in the mammary tissue at -10 days from lambing, 150 days of lactation and at 8 days of involution. This finding could indicate that caspase-3 is not involved in sheep mammary gland apoptosis, but that other proteins - such as apoptosis inducing factor (AIF) - can trigger apoptosis, through the m...

2009-01-01

111

Neutron beam experiments using nuclear research reactors: honoring the retirement of professor Bernard W. Wehring -II. 4. Accurate Characterization of the Shape of the HPGe Detector Peak Efficiency Curve for Application in PGNAA  

International Nuclear Information System (INIS)

In various situations, measurements in prompt gamma neutron activation analysis (PGNAA) are performed to determine the amount of an elemental impurity relative to that of a major constituent of the matrix. An example of this is the measurement of hydrogen concentration in a metallic matrix. In all such cases, a major contributor to the uncertainty in the measurement is the uncertainty in the ratio of the high-purity germanium (HPGe) detector full-energy peak efficiency for the gamma-ray lines of interest (i.e., impurity and matrix gammas). Usually, the ratio is derived from the relative peak efficiency curve, which is determined using isotopic standards that emit multiple gamma ray lines (e.g., "1"5"2Eu) in the energy range <3000 keV, or using prompt gamma radionuclides (e.g., "1"4N, "3"5Cl) in the energy range >3000 keV. In either case, the uncertainty in the ratio of the peak efficiency values derived from such measurements will be on the order of a few ...

2001-06-17

112

Fault detection by Turam TEM survey. Numerical model studies and a case history; TEM ho Turam sokutei haichi ni yoru danso kenshutsu no kokoromi. Model keisan to jisshirei  

Energy Technology Data Exchange (ETDEWEB)

With an objective to detect faults estimated to exist along the Shigesumi valley in the Kamioka mine, discussions were given by using electromagnetic survey, which uses the Turam measurement arrangement based on the TEM method, and three-dimensional model calculations. The Turam measurement arrangement, which installs transmission loop fixedly, is used to identify nature and distribution of electrically conductive objects upon noticing abnormal portions in magnetic fields in the measurement data. In the model calculation, the plate model calculation method and the FDTD method were used, and so was the calculation code TEM3DL. The result revealed that strong topographical influence is seen from steep V-shaped valley existing along the traverse line in the measurement data, but an abnormal resistivity band accompanying remarkable distortion in the curve was detected. According to the result of the ...

1997-05-27

113

Complex fluid analysis with the advanced distillation curve approach.  

Science.gov (United States)

An improved method for measuring distillation curves reveals the physicochemical properties of complex fluids such as fuels. PMID:20041713

2010-02-01

114

The relationship between income and environment in Turkey: Is there an environmental Kuznets curve?  

British Library Electronic Table of Contents (United Kingdom)

In this study, we investigate the relationship between income and environmental quality for Turkey at two levels. First, the relationship between the CO2 emissions and per capita income is examined by the help of a time series model using cointegration techniques. In the second stage, the relationship between income and air pollution is investigated by using PM10 and SO2 measurements in Turkish provinces. In this part of the study panel data estimation techniques are utilized. The time series model covers 1968-2003, and the panel data model covers 1992-2001 including observations from 58 provinces. A monotonically increasing relationship between CO2 and income is found in the long-run according to time series analysis. On the other hand, panel data analysis indicates an N-shape relationshi...

2009-01-01

115

Scale-up of two-phase flow in heterogeneous chalk. Matrix properties  

Energy Technology Data Exchange (ETDEWEB)

This investigation presents scale-up of a detailed heterogeneous geostatistical model to a full field reservoir simulation model, considering both single and two-phase flow properties. The model represents a typical low permeability Danish North Sea chalk reservoir and includes capillary pressure and saturation end-point variations. Two new up-scaling methods has been investigated, all based on fine scale simulation on a cross section of the geomodel. The first methods assumes piston style behaviour and a coupled viscosity is introduced into the basic Darcy`s equations. The second method is a modification of the JBN method traditionally applied in analysing results from core flooding experiments, which emerged as the most successful and therefore also the recommended method. 1. In addition to the up scaling work we review the Equivalent Radius Method for capillary pressure normalisation with explicit derivation of type ...

1998-02-01

116

Physiologically based toxicokinetic modelling as a tool to assess target organ toxicity in route-to-route extrapolation-The case of coumarin  

British Library Electronic Table of Contents (United Kingdom)

Coumarin (1,2-benzopyrone) is occurring in food, and is also used in cosmetics. In order to perform a risk assessment for both oral and dermal exposure, we applied a physiologically based approach to model kinetics in humans by simulating both routes of exposure. The concentration-time profile in liver revealed a higher peak concentration (Cmax-hep) for the oral when compared to the dermal route. The area under the concentration-time curve in the liver (AUChep) was found the same for both routes if the same extent of absorption is assumed. Dose response information from published rat studies were used to identify the metric relevant for liver toxicity. Liver exposure levels resulting from doses and durations as outlined in the studies were simulated in a rat model. We obtained 31 data pair...

2011-01-01

117

Fatigue lifetime and endurance-limit prediction for high-strength steels; Vorhersage der Lebensdauer und Dauerfestigkeit von hochfesten, durchhaerteten Staehlen  

Energy Technology Data Exchange (ETDEWEB)

Smooth and notched specimens of the bearing steel 100Cr6 (SAE 52100) in a bainitic condition were used to determine the S-N curves under tensile, torsional and combined in- and out-of-phase loading. In the area of high-cycle fatigue, crack initiation was most likely caused by inclusions like Titanium Carbon nitrides or Aluminium Oxides. A micro mechanical model for the crack initiation by inclusions was developed. Another model was developed to describe the influence of these inclusions on the lifetime. A weakest-link model, using the statistical distribution of inclusions and surface flaws, was used to describe the endurance limit. (orig.)

2002-07-01

118

Chemically authentic surrogate mixture model for the thermophysical properties of a coal-derived liquid fuel  

Energy Technology Data Exchange (ETDEWEB)

We developed a surrogate mixture model to represent the physical properties of a coal-derived liquid fuel using only information obtained from a gas chromatography-mass spectrometry analysis of the fuel and a recently developed 'advanced distillation curve'. We then predicted the density, speed of sound, and viscosity of the fuel and compared them to limited experimental data. The surrogate contains five components (n-propylcyclohexane, trans-decalin, {alpha}-methyldecalin, bicyclohexane, and n-hexadecane), yet comparisons to limited experimental data demonstrate that the model is able to represent the density, sound speed, and viscosity to within 1, 4, and 5%, respectively. 102 refs., 2 figs., 5 tabs.

2008-09-15

119

SIMS and XRD measurements for the critical review of carbon diffusivity derivation from hardness profiles  

Energy Technology Data Exchange (ETDEWEB)

Microhardness decarburization profiles are often used in the industry to estimate the carbon distribution in steels. For quantitative evaluation, an analysis based on diffusion theory must be performed, the fundamentals and mathematical basics of which are presented. If the relationship between hardness and carbon content is known, microhardness-distance curves of steels can be analyzed in this way. For martensitic grades, for instance, a linearized expression holds in the concentration range from 0.15 to 0.6 m.% C. Microhardness depth profiles of higher carbon steels and other microstructures, however, are also evaluated in the literature. The applicability of quantitative diffusion modeling is discussed in detail. Through hardenable rolling bearing steel 100Cr6 (1.3505, SAE 52100) serves as model material: carbon concentration-distance curves are measured with high accuracy by secondary ion mass ...

2007-07-01

120

Evaluation of small-angle neutron scattering curves of unilamellar phosphatidylcholine liposomes using a multi shell model of bilayer neutron scattering length density  

International Nuclear Information System (INIS)

Computer simulated small-angle neutron scattering curves of spherical poly disperse extruded unilamellar liposomes from saturated 1,2-diacylphosphatidylcholines in the aqueous phase are evaluated by using a multi shell model, which divides the lipid bilayer of liposomes into the polar head group region, and the nonpolar hydrocarbon region consisting of the chains of methylene groups and of the region of methyl groups. In the each of these regions, the coherent neutron scattering length density is supposed to by homogeneous. The evaluation is based on obtaining of radius of gyration from Kratky-Porod plot of small-angle neutron scattering data in the Guinier region of small scattering vector values. From radii of gyration obtained at several different molar fractions N_D_2_O/(N_D-2_O + N_H_2_O) in the aqueous phase (contrasts) and independent volumetric data, the lipid surface area A_L (or the bilayer thickness d_L) and the number of water ...

2000-12-15

121

Evaluation of Dynamic Passing Sight Distance Problem Using a Finite Element Model  

Energy Technology Data Exchange (ETDEWEB)

Sufficient passing sight distance is an important control for two-lane rural highway design to minimize the possibility of a head-on collision between passing and opposing vehicles. Traditionally, passing zones are marked by checking passing sight distance that is potentially restricted by static sight obstructions. Such obstructions include crest curves, overpasses, and lateral objects along highways. This paper proposes a new concept of dynamic sight-distance assessment, which involves restricted passing sight distances due to the impeding vehicles that are traveling in the same direction. Using a finite-element model, the dynamic passing sight-distance problem was evaluated, and the writers analyzed the relationships between the available passing sight distance and other factors such as the horizontal curve radius, impeding vehicle dimensions, and a driver s following distance. It was found that the impeding vehicles may ...

2008-06-01

122

Elastic scattering of 27.2 MeV alpha particle on "4"0Ca nucleus  

International Nuclear Information System (INIS)

Elastic scattering of 27.2 MeV #alpha# particles on "4"0Ca has been investigated. Differential cross sections have been measured in the angular range from 10 deg to 175 deg in the lab. system. The theoretical analysis has proceeded from the proposition that the results of a calculation based on the optical model in the range of small angles (less than 20 deg for "4"0Ca) are independent of parameters and shape of the potential employed. Elastic scattering of #alpha# particles at angles up to 50 deg has been calculated using three sets of the optical potential parameters in the energy range 23.37-28.92 MeV. In the range of small angles a rather similar behaviour of the calculated curves can be observed whereas in the range of medium and large angles these curves behave very differently. The success in the reproduction of the angular distributions for the entire energy range is indicative of the weak energy dependence of the ...

123

Characterization system for Germanium detectors dedicated to gamma spectroscopy applied to nuclear waste  

International Nuclear Information System (INIS)

CEA-Valduc produces some radioactive waste (mainly alpha emitters). Legislation requires producers to sort their waste by activity and type of isotopes, and to package them in order to forward them to the appropriate reprocessing or storage facility. Our lab LMDE (laboratory for measurements on nuclear wastes and valuation) is in charge of the characterization of the majority of waste produced by CEA-Valduc. Among non-destructive methods to characterize a radioactive object, gamma-spectroscopy is one of the most efficient. We present to this conference the method we use to characterize nuclear waste and the system we developed to characterize our germanium detectors. The goal of this system is to obtain reliable numerical models of our detectors and calculate their efficiency curves. Measurements are necessary to checks models and improve them. These measurements are made on a bench using pinpoint sources ("1"3"3Ba, ...

2009-06-07

124

Absorption Features in Spectra of Magnetized Neutron Stars  

CERN Document Server

The X-ray spectra of some magnetized isolated neutron stars (NSs) show absorption features with equivalent widths (EWs) of 50 - 200 eV, whose nature is not yet well known. To explain the prominent absorption features in the soft X-ray spectra of the highly magnetized (B ~ 10^{14} G) X-ray dim isolated NSs (XDINSs), we theoretically investigate different NS local surface models, including naked condensed iron surfaces and partially ionized hydrogen model atmospheres, with semi-infinite and thin atmospheres above the condensed surface. We also developed a code for computing light curves and integral emergent spectra of magnetized neutron stars with various temperature and magnetic field distributions over the NS surface. We compare the general properties of the computed and observed light curves and integral spectra for XDINS RBS\\,1223 and conclude that the observations can be explained by a thin ...

2010-01-01

125

A critical survey of experimental cross section data, comparison with nuclear model calculations and estimation of production yields of "7"7Br and "7"7Kr in no-carrier-added form via various nuclear processes  

International Nuclear Information System (INIS)

Experimentally investigated nuclear reactions for production of no-carrier-added "7"7Br and "7"7Kr were critically surveyed. The survey covered nine reactions for the formation of "7"7Br and six reactions for "7"7Kr. Both radionuclides are simultaneously produced in many of the studied nuclear processes. The experimental data were compared with the results of nuclear model calculations based on the computer code ALICE-IPPE and the third version of TALYS-based Evaluated Nuclear Data Library, TENDL-2010. Good agreement was found over extended energy regions for the p-, "3He- and #alpha#-particle induced reactions on several target materials. In case of d-induced reactions, however, considerable discrepancies were noted between the experimental and theoretical data. The concordant sets of experimental cross section data for each reaction were fitted by a polynomial function to obtain a trend curve. From the thus obtained trend ...

2011-05-15

126

The persistence of antibiotic resistance: evaluation of a probiotic approach using antibiotic-sensitive M. elsdenii strains to prevent colonization of swine by antibiotic-resistant strains  

Science.gov (United States)

Megasphaera elsdenii is a lactate-fermenting, obligately anaerobic bacterium commonly present in the gastrointestinal tracts of mammals, including humans. Swine M. elsdenii strains were previously shown to have high levels of tetracycline resistance (MIC = 64->256 micro g/ml) and to carry mosaic (re...

127

Staphylococcus aureus Enterotoxin D Is Secreted in Milk and Stimulates Specific Antibody Responses in Cows in the Course of Experimental Intramammary Infection  

UK PubMed Central (United Kingdom)

An enterotoxin D (SED)-producing strain of Staphylococcus aureus was used to infect one mammary gland of each of 17 lactating dairy cows. All glands became infected and shed bacteria...Full Text Available

2006-06-01

128

Evaluation of the rapid diagnostic test SDFK40 (Pf-pLDH/pan-pLDH) for the diagnosis of malaria in a non-endemic setting  

UK PubMed Central (United Kingdom)

BackgroundThe present study evaluated the SD Bioline Malaria Ag 05FK40 (SDFK40), a three-band RDT detecting Plasmodium falciparum-specific parasite lactate dehydrogenase...Full Text Available

129

Effects of 2 commercially-available 9-way killed vaccines on milk production and rectal temperature in Holstein-Friesian dairy cows.  

UK PubMed Central (United Kingdom)

Veterinarians and farmers employing multivalent killed vaccines in lactating dairy cows have reported transient losses in milk production. Few studies have quantified this loss. In this report, effects...Full Text Available

2001-10-01

130

Uncertainties of radionuclide migration parameter values obtained from in-situ tracer experiments  

International Nuclear Information System (INIS)

One of the key issues in safety assessment of high-level nuclear waste disposal is evaluating the effects of uncertainty inherent in radionuclide migration parameter values. In this paper, radionuclide transport parameter values and error variances (uncertainties) from in-situ tracer experiments, carried out in a single fracture at the Aespoe Hard Rock Laboratory (HRL) in Sweden, are identified by solving the inverse problem in a framework of the maximum likelihood theory. From the results, it is found that the parameter value uncertainty caused by a conceptual model of radionuclide migration is greater than that caused by a fluctuation in the observed breakthrough curve data. (author)

2005-10-03

131

Stability constants of At(I)-complexes with thiourea, iodide and mixed ligands in ethanol and water  

International Nuclear Information System (INIS)

The ion mobilities of |"2"1"1At|At(I) in dependence on thiourea (tu) concentration, iodide concentration and a mixture of both ligands were measured by the electromigration method in free electrolytes. An equilibrium model was developed for the characterization of electromigration curves which permitted the calculation of stability constants and ion mobilities of the complexes |AtI|, |AtI_2|"-, |Attu|"+, |Attu_2|"+ and |AtItu| existing in these solutions. Ethanol and water served as solvents. The temperature was 298 K and the ionic strength was about 0.05 mol/dm"3. (author) 16 refs.; 2 figs.

132

Real time estimation of photovoltaic modules characteristics and its application to maximum power point operation  

Energy Technology Data Exchange (ETDEWEB)

In this paper, an approximate curve fitting method for photovoltaic modules is presented. The operation is based on solving a simple solar cell electrical model by a microcontroller in real time. Only four voltage and current coordinates are needed to obtain the solar module parameters and set its operation at maximum power in any conditions of illumination and temperature. Despite its simplicity, this method is suitable for low cost real time applications, as control loop reference generator in photovoltaic maximum power point circuits. The theory that supports the estimator together with simulations and experimental results are presented. (author)

2007-05-15

133

NMR study of one-dimensional ionic conductor with hollandite-type structure (IV) Rb-priderite  

International Nuclear Information System (INIS)

Conduction properties of Rb"+ ion in Rb-Al-priderite and K"+ ion and Rb"+ ion in (K,Rb)-Al-priderite, were investigated by NMR using "2"7Al in the framework as a probe. Size effect was observed remarkably in the activation energies. Frequency dependence of T_1 in Rb-Al-priderite at a low temperature indicates that the relaxation behavior of "2"7Al in Rb-Al-priderite can be described by the continuum model. Barrier height distributions and 'attempt frequencies' in both samples obtained by a curve-fitting method are discussed in comparison with those of K-Al-priderite. (orig.).

1985-08-18

134

Matrix Model, Kutasov Duality and Factorization of Seiberg-Witten Curves  

Energy Technology Data Exchange (ETDEWEB)

We study the duality of N=1 gauge theories in the presence of a massless adjoint field. We calculate the superpotential using the factorization method and compare with the result obtained by applying Kutasov duality. The latter result is just the leading term of the former, indicating that Kutasov duality is exact only in the IR limit as claimed in the original literature. We also study various checks for the equivalence of the calculational methods developed recently: factorization methods, diagrammatic expansion, loop equations, integrating fluxes.

2003-09-29

135

Level structure of the doubly-odd /sup 242/Am nucleus  

Energy Technology Data Exchange (ETDEWEB)

The level structure of the doubly-odd /sup 242/Am nucleus was investigated by means of thermal-neutron-capture gamma-ray and conversion electron spectroscopy. Pair, curved-crystal, and ..beta.. spectrometers were used. The data from these measurements, combined with previous direct reaction results, permit us to establish a detailed level scheme including six new well-developed bands. Our experimental results are interpreted in the framework of the Nilsson model. Precise Gallagher-Moszkowski splittings and Newby odd-even shifts extracted from the data are compared with theoretical calculations.

1988-06-01

136

Does energy substitution affect carbon dioxide emissions - Income relationship?  

British Library Electronic Table of Contents (United Kingdom)

Considerable discussion has taken place during the last decade regarding the role of economic growth in determining environmental quality. Using data from 30 OECD countries for the period 1960-2003 and the nonparametric method of generalized additive models, which enables us to use flexible functional forms, this paper examines the environmental Kuznets curve hypothesis for carbon dioxide (CO2). We find that the reduction of coal share in energy use has a significant effect on CO2. Our results imply that economic growth is not sufficient to decrease CO2 emissions.

2010-01-01

137

Transient radon diffusion through radon-proof membranes: A new technique for more precise determination of the radon diffusion coefficient  

Energy Technology Data Exchange (ETDEWEB)

The following paper is focused on the numerical modelling of the transient radon diffusion through radon-proof membranes during the measurement of their radon diffusion coefficient. The major aim of such numerical modelling is to increase the accuracy of radon diffusion coefficients derived from the measured data sets. The developed complex ''transient'' numerical model is able to calculate the radon diffusion coefficient with sufficient accuracy from almost any data set - even from a short-time measurement with a non-linear course of results. This numerical model can also be used for various analyses of transient radon transfer processes (e.g. for the calculation of radon distribution curves within the membrane). The following paper presents governing equations for the simulation model, together with a brief description of ...

2009-06-15

138

Semiempirical model based on thermodynamic principles for determining 6 kW proton exchange membrane electrolyzer stack characteristics  

Energy Technology Data Exchange (ETDEWEB)

The performance of a 6 kW proton exchange membrane (PEM) electrolyzer was modeled using a semiempirical equation. Total cell voltage was represented as a sum of the Nernst voltage, activation overpotential and ohmic overpotential. A temperature and pressure dependent Nernst potential, derived from thermodynamic principles, was used to model the 20 cell PEM electrolyzer stack. The importance of including the temperature dependence of various model components is clearly demonstrated. The reversible potential without the pressure effect decreases with increasing temperature in a linear fashion. The exchange current densities at both the electrodes and the membrane conductivity were the coefficients of the semiempirical equation. An experimental system designed around a 6 kW PEM electrolyzer was used to obtain the current-voltage characteristics at different stack temperatures. A nonlinear curve fitting ...

2008-12-01

139

Estimation of parameters affecting the uptake of sup(99m)Tc-methylenediphosphonate in rat femur with model simulation  

Energy Technology Data Exchange (ETDEWEB)

The uptake of sup(99m)Tc-methylenediphosphonate (MDP) in different parts of rat femur was simulated using a local three-space model for tracer transfer. The model consisted of bone blood, bone ECF-space and space for tracer deposition. The measured sup(99m)Tc-MDP concentration in the systemic blood and the local bone blood flow measured by /sup 131/I-macroaggregated albumin microspheres were used as input parameters. The measured blood flow values were 6.3, 3.1 and 15.3 ml/100 g/min for proximal, middle and distal femur, respectively. the model parameters that gave the best fit to measured sup(99m)Tc-MDP uptake curves in computer simulation showed that bone blood flow, volume of ECF-space, permeability surface area product and accretion constant from ECF-space to space for tracer deposition were highest in distal and lowest in middle femur. The values corresponded to peak extraction fractions of 0.38, ...

1985-01-01

140

Estimation of parameters affecting the uptake of sup(99m)Tc-methylenediphosphonate in rat femur with model simulation  

International Nuclear Information System (INIS)

The uptake of sup(99m)Tc-methylenediphosphonate (MDP) in different parts of rat femur was simulated using a local three-space model for tracer transfer. The model consisted of bone blood, bone ECF-space and space for tracer deposition. The measured sup(99m)Tc-MDP concentration in the systemic blood and the local bone blood flow measured by "1"3"1I-macroaggregated albumin microspheres were used as input parameters. The measured blood flow values were 6.3, 3.1 and 15.3 ml/100 g/min for proximal, middle and distal femur, respectively. the model parameters that gave the best fit to measured sup(99m)Tc-MDP uptake curves in computer simulation showed that bone blood flow, volume of ECF-space, permeability surface area product and accretion constant from ECF-space to space for tracer deposition were highest in distal and lowest in middle femur. The values corresponded to peak extraction fractions of 0.38, ...

141

Simulation of uranium oxides reduction kinetics by hydrogen. Reactivities of germination and growth; Modelisation de la cinetique de reduction d`oxydes d`uranium par l`hydrogene. Reactivites de germination et de croissance  

Energy Technology Data Exchange (ETDEWEB)

The aim of this work is to simulate the reduction by hydrogen of the tri-uranium octo-oxide U{sub 3}O{sub 8} (obtained by uranium trioxide calcination) into uranium dioxide. The kinetics curves have been obtained by thermal gravimetric analysis, the hydrogen and steam pressures being defined. The geometrical modeling which has allowed to explain the trend of the kinetics curves and of the velocity curves is an anisotropic germination-growth modeling. The powder is supposed to be formed of spherical grains with the same radius. The germs of the new UO{sub 2} phase appear at the surface of the U{sub 3}O{sub 8} grains with a specific germination frequency. The growth reactivity is anisotropic and is very large in the tangential direction to the grains surface. Then, the uranium dioxide growths inside the grain and the limiting step is the grain surface. The variations of the growth ...

1997-12-04

142

DNA damage intensity in fibroblasts in a 3-dimensional collagen matrix correlates with the Bragg curve energy distribution of a high LET particle  

International Nuclear Information System (INIS)

The DNA double-strand break (DSB) damage response induced by high energy charged particles on lung fibroblast cells embedded in a 3-dimensional (3-D) collagen tissue equivalents was investigated using antibodies to the DNA damage response proteins gamma-histone 2AX (#gamma#-H2AX) and phosphorylated DNA-PKcs (p-DNA-PKcs). 3-D tissue equivalents were irradiated in positions across the linear distribution of the Bragg curve profiles of 307.7 MeV/nucleon, 556.9 MeV/nucleon, or 967.0 MeV/nucleon "5"6Fe ions at a dose of 0.30 Gy. Patterns of discrete DNA damage streaks across nuclei or saturated nuclear damage were observed, with saturated nuclear damage being more predominant as samples were positioned closer to the physical Bragg peak. Quantification of the DNA damage signal intensities at each distance for each of the examined energies revealed a biological Bragg curve profile with a pattern of DNA damage intensity similar to the physical Bragg ...

2010-03-01

143

Structure and kinematics of edge-on galaxy discs -- IV. The kinematics of the stellar discs  

CERN Document Server

The stellar disc kinematics in a sample of fifteen intermediate- to late-type edge-on spiral galaxies are studied using a dynamical modeling technique. The sample covers a substantial range in maximum rotation velocity and deprojected face-on surface brightness and contains seven spirals with either a boxy- or peanut-shaped bulge. Dynamical models of the stellar discs are constructed using the disc structure from $I$-band surface photometry and rotation curves observed in the gas. The differences in the line-of-sight stellar kinematics between the models and absorption line spectroscopy are minimized using a least-squares approach. The modeling constrains the disc surface density and stellar radial velocity dispersion at a fiducial radius through the free parameter $\\sqrt{M/L}$ $(\\sigma_{\\rm z}/\\sigma_{\\rm R})^{-1}$, where $\\sigma_{\\rm z}/\\sigma_{\\rm R}$ is the ratio of ...

2005-01-01

144

Probabilistic power generation planning with environmental consideration for Lebanon  

International Nuclear Information System (INIS)

Full text.This paper describes a software tool for generation expansion planning based on dynamic programming, probabilistic production simulation, and environmental assessment. The aim is to determine the units needed to expand a given system in order to minimize either the cost or the environmental impact or some weighed function of the two. The problem of generation expansion planning is solved in stages using Tunnel Dynamic Programming (TDP) with Heuristic rules to limit the number of options analyzed. The production costing methodology is based on combining a probabilistic generation model known as the capacity outage table (COT) with the load duration curve (LDC) of the system to deduce a risk model from which the expected energy not supplied (EENS) is estimated. The generation model is built recursively using an efficient numerical convolution procedure and is combined at each step with the LDC ...

2000-11-23

145

A unified model of combined energy systems with different cycle modes and its optimum performance characteristics  

Energy Technology Data Exchange (ETDEWEB)

A unified model is presented for a class of combined energy systems, in which the systems mainly consist of a heat engine, a combustor and a counter-flow heat exchanger and the heat engine in the systems may have different thermodynamic cycle modes such as the Brayton cycle, Carnot cycle, Stirling cycle, Ericsson cycle, and so on. Not only the irreversibilities of the heat leak and finite-rate heat transfer but also the different cycle modes of the heat engine are considered in the model. On the basis of Newton's law, expressions for the overall efficiency and power output of the combined energy system with an irreversible Brayton cycle are derived. The maximum overall efficiency and power output and other relevant parameters are calculated. The general characteristic curves of the system are presented for some given parameters. Several interesting cases are discussed in detail. The results obtained here are very ...

2009-06-15

146

A simple model for strontium breakthrough on zeolite columns  

Science.gov (United States)

The Process Waste Treatment Plant (PWTP) at the Oak Ridge National Laboratory is designed to remove radioactive contaminants, principally {sup 90}Sr, from process wastewater. Planned upgrades to the PWTP will use chabazite zeolite columns. Pilot-scale studies have shown that mass transfer zone lengths increase from 10 to about 30 cm as the superficial velocity increases from 5.5 to 22 cm/min. Calculations with a multicomponent equilibrium model showed that the distribution coefficient for strontium remains essentially constant over the process conditions, suggesting that a simple kinetic model (the Rosen long-bed solution) should adequately represent breakthrough behavior. Using a distribution coefficient of 4.87 L/g predicted by the equilibrium model, good agreement was found between experimental breakthrough curves and those calculated with the Rosen solution. This model allows ...

1995-04-01

147

Use of structural equation modeling to examine the relationships between growth, trade and the environment in developing countries  

British Library Electronic Table of Contents (United Kingdom)

According to the environmental Kuznets curve hypothesis, environmental degradation increases in the early stages of growth, but it eventually decreases as income exceeds a threshold level. It is thus often argued that if international trade increases incomes then it can also have a positive impact on environmental quality. So far, these hypotheses have been widely empirically tested for the developed countries. However, it is still uncertain whether positive effects of international trade on growth and on the environment may also hold in developing countries. One of the major difficulties in testing these relations in developing countries is the poor quality of environment related data. In this analysis this problem is reduced by constructing a structural equation model (SEM) with three la...

2006-01-01

148

Understanding the volatility smile of options markets through microsimulation  

CERN Document Server

In this work, we aim to gain a better understanding of the volatility smile observed in options markets through microsimulation (MS). We adopt two types of active traders in our MS model: speculators and arbitrageurs, and call and put options on one underlying asset. Speculators make decisions based on their expectations of the asset price at the option expiration time. Arbitrageurs trade at different arbitrage opportunities such as violation of put-call parity. Difference in liquidity among options is also included. Notwithstanding its simplicity, our model can generate implied volatility (IV) curves similar to empirical observations. Our results suggest that the volatility smile is related to the competing effect of heterogeneous trading behavior and the impact of differential liquidity.

2007-01-01

149

Predicting moisture state of timber members in a continuously varying climate  

British Library Electronic Table of Contents (United Kingdom)

A prerequisite for a sensible estimate of moisture induced stresses in timber members is an accurate prediction of the members' moisture states during their service life. There are, however, an infinite number of possible moisture states for an arbitrary timber member in a natural varying climate. The naturally varying humidity is possible to describe as harmonic cycles, with different periods, superimposed. This work presents realizations of envelop curves over the possible moisture states in a timber member for some carefully chosen harmonic humidity variations. The calculations, on which the realizations were made, are based on a fully coupled transport model including a model for the influential sorption hysteresis of wood. A format containing required information suitable for assessin...

2011-01-01

150

Grain mantles: The impact on grain evolution and selective extinction  

International Nuclear Information System (INIS)

Depletion studies are used to infer the presence of mantles and to constrain grain evolutionary models in the diffuse interstellar medium. The presence of these mantles appears to be important in the evolution of the grains inside diffuse as well as dense clouds. In dense clouds where the element-to-element abundances sometimes differ from those found in diffuse clouds, empirical relationships are starting to emerge between gas abundances and various types of peculiar selective extinction. These peculiar extinction curves may be the results of nonvolatile mantle formation on grain cores or may reflect chemical differences due to variations in the intrinsic metalicity from one cloud to another. A simple model of the time evolution of a parcel of gas and dust as observed by the depletion of two elements is presented. Different studies of grain evolution and selective extinction are discussed and compared.

1989-12-01

151

Forced vibration tests on three types of embedded structures (embedment effect test on soil-structure interaction)  

International Nuclear Information System (INIS)

A series of Model Tests of Embedment Effect on Reactor Buildings has been carried out by the Nuclear Power Engineering Corporation (NUPEC), under the sponsorship of the Ministry of International Trade and Industry (MITI) of Japan. Sinusoidal forced vibration tests were carried out on three types of large-scale models to study the embedment effect on dynamic soil-structure interaction. The differences in the resonance curves and the impedance functions were discussed in relation to the vibration characteristics of the respective structures. The embedment effects on the structural responses vary according to the stiffness of the structure. The responses of the structures can be evaluated by the Axisymmetric FEM analyses. (author)

1993-08-15

152

Economic analysis of nuclear power generation  

Energy Technology Data Exchange (ETDEWEB)

The major contents in this study are as follows : - long-term forecast to the year of 2040 is provided for nuclear electricity generating capacity by means of logistic curve fitting method. - the role of nuclear power in a national economy is analyzed in terms of environmental regulation. To do so, energy-economy linked model is developed. By using this model, the benefits from the introduction of nuclear power in Korea are estimated. Study on inter-industry economic activity for nuclear industry is carried out by means of an input-output analysis. Nuclear industry is examined in terms of inducement effect of production, of value-added, and of import. - economic analysis of nuclear power generation is performed especially taking into consideration wide variations of foreign currency exchange rate. The result is expressed in levelized generating costs. (author). 27 refs., 24 tabs., 44 figs

1997-12-01

153

An analysis and evaluation of differential pressure calculation of motor operated valve using system flow model  

Energy Technology Data Exchange (ETDEWEB)

As part of the EPRI Motor-Operated Valve (MOV) Performance Prediction Methodology, a System Flow Model (SFM) has been developed to determine the differential pressure (DP) across MOVs as they are stroked in typical power plant systems. Input to the SFM includes valve flow characteristics (such as flow coefficient) and system characteristics (such as pump head/flow curve). The primary output is differential pressure across the valve at each stroke position. The SFM was validated by comparison with test data from the EPRI Flow Loop Test Program. In this study, we calculated DP using SFM and performed DP test for four MOVs. Compared between calculated DP and test DP of four MOV, respectively good agreements are found. (author). 6 refs., 9 figs., 1 tab.

1999-11-01

154

Seismic stratigraphy and stratigraphic modelling of the South-eastern German Molasse Basin  

Science.gov (United States)

Although the German Molasse Basin can be regarded as a mature hydrocarbon province, no regional sequence stratigraphic analysis has been carried out so far. We have studied seismic lines and well data from the region between the Isar and Inn rivers (SE Germany) that have been generously supplied by German oil companies (DEE, BEB, Mobil, RWE-DEA and Wintershall). Initial work indicates that five major seismic sequences within three main depositional cycles are developed. The Alpine thrust belt to the south serves as the primary sediment source in the foreland basin. However, sedimentary infill mainly took place parallel to the basin axis. Our analysis suggests that the stratigraphic development of the Molasse Basin was mainly controlled by eustatic sea-level changes which caused the shoreline to shift in the W-E direction. The shifting of the depocenter axis in a N-S direction was controlled by the tectonic evolution of the thrust belt. The sea-level curve ...

1995-08-01

155

Dynamical Cycles in Charge and Energy for Iron Ions Accelerated in a Hot Plasma  

Science.gov (United States)

We consider a unified model of Fe ion acceleration in the solar corona. The model comprises charge-changing processes, Coulomb energy losses, and both regular and stochastic acceleration. At a given acceleration scenario, the type of acceleration is found to have a minor effect on the mean charge states, but the shapes of the charge-state distributions produced by regular acceleration and by stochastic acceleration are different. During a continual acceleration at coronal temperatures, iron ions typically follow rising trajectories on the charge-energy plane. These trajectories are situated below the mean equilibrium charge curve defined from the balance of ionization and recombination at fixed energy. During stopping, the iron ions cross the equilibrium charge curve and run through a series of charge states above the mean equilibrium charge at current energy, because the Coulomb deceleration rate ...

2001-08-01

156

User's manual of SECOM2: a computer code for seismic system reliability analysis  

International Nuclear Information System (INIS)

This report is the user's manual of seismic system reliability analysis code SECOM2 (Seismic Core Melt Frequency Evaluation Code Ver.2) developed at the Japan Atomic Energy Research Institute for systems reliability analysis, which is one of the tasks of seismic probabilistic safety assessment (PSA) of nuclear power plants (NPPs). The SECOM2 code has many functions such as: Calculation of component failure probabilities based on the response factor method, Extraction of minimal cut sets (MCSs), Calculation of conditional system failure probabilities for given seismic motion levels at the site of an NPP, Calculation of accident sequence frequencies and the core damage frequency (CDF) with use of the seismic hazard curve, Importance analysis using various indicators, Uncertainty analysis, Calculation of the CDF taking into account the effect of the correlations of responses and capacities of components, and Efficient sensitivity analysis by changing parameters on ...

157

The effect of heat transfer augmentation on two-phase flow instabilities in a vertical boiling channel  

International Nuclear Information System (INIS)

Experimental and theoretical work have been carried out to find out the effects of heat transfer augmentation on two-phase flow instabilities in a single channel system. The effect of mass flow rate, heat input and inlet subcooling on the system behavior is studied using Freon-11 as the test fluid and six different heater surfaces are tested at various experimental conditions. Experimental evaluation is done using the steady-state pressure drop versus mass flow rate curves along with the curves of additional inlet pressure drop required to stabilize the system during the oscillations, and tables generated using the experimental data. Homogeneous equilibrium flow model and finite differences are used in theoretical analysis. An empirical relationship is obtained to calculate the pressure drop across the exit restriction. Characteristic equation for the system is found by linearizing the dynamic equations of the overall ...

1985-11-01

158

Structure and kinematics of edge-on galaxy discs - I. Observations of the stellar kinematics  

CERN Document Server

We present deep optical long-slit spectra of 17 edge-on spiral galaxies of intermediate to late morphological type, mostly parallel to their major axes and in a few cases parallel to the minor axes.The line-of-sight stellar kinematics are obtained from the stellar absorption lines using the improvedc ross-correlation technique. In general, the stellar kinematics are regular and can be traced well into the disc-dominated region. The mean stellar velocity curves are far from solid-body, indicating that the effect of dust extinction is not large. The line-of-sight stellar disc velocity dispersion correlates with the galaxy maximum rotational velocity, but detailed modeling is necessary to establish whether this represents a physical relation. In four spirals with a boxy- or peanut-shaped bulge we are able to detect asymmetric velocity distributions, having a common signature with projected radius in the mean line-of-sight velocity and the $h_{3}$ ...

2004-01-01

159

Rotational velocities and central velocity dispersions for a sample of S0 galaxies  

International Nuclear Information System (INIS)

Central velocity dispersions and rotation curves to radii of approx.5 kpc have been measured for 32 galaxies, mostly field S0's. Our rotation curves confirm the result of Kormendy and Illingworth that the bulges of S0 galaxies are in rapid rotation, with enough rotational kinetic energy to account for their flattenings. The V/sigma-ellipticity relation we find for S0 bulges is compared with similar data for elliptical galaxies from Davies et al. We conclude that (1) faint SO bluges and elliptical galaxies (M/sub B/ fainter than -20.5) are both consistent with oblate rotators with isotropic velocity dispersions (although in our sample, S0 bluges are flatter, on the average, than ellipticals) and (2) bright S0 bulges, -22.0models, but bright ellipticals are not. Hence a significant kinematic difference persists between S0 bulges and ellipticals. This difference suggests ...

160

Quantification of the local glucose utilization and local blood flow in the heart of the awake rat using the /sup 14/C-2-deoxyglucose and /sup 14/C-iodoantipyrine methods  

Science.gov (United States)

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.

1986-03-05

161

Evaluation of the Curve-fitting method and the Horner-plot method for estimation of the true formation temperature using temperature recovery logging data  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the method to estimate the true formation temperature using temperature recovery logging data after the well reach to total depth (T.D.). The method designated as ''Curve-fitting method (CFM)'' is based on mathematical model proposed by Middleton (1979, 1982). The accuracy and applicability of this method are evaluated with several field data and compared advantageously with the Horner-plot method. Then, real-time data acquisition system including interpretation software has also been successfully developed. As a conclusion, the followings are confirmed: (1) The developed CFM can be applicable to the estimation of the true formation temperature even using 24 hours temperature recovery data, although the Horner-plot method might need up to 120 hours recovery data, usually. (2) Though depending upon the quality of the data and/or number of the temperature recovery logging data, it might be ...

1995-01-26

162

Effects of palladium particle size and palladium silicide formation on fourier transform infrared spectra of CO adsorbed on Pd/SiO sub 2 catalysts  

Energy Technology Data Exchange (ETDEWEB)

Two major modes of CO adsorption on SiO{sub 2}-supported Pd reflect different extents of back-donation, which is, at least in part, controlled by the local electron density at the adsorption site. The fraction of CO in the bridging mode (B) increases and that of the linear mode (L) decreases, with increasing size of the Pd particles, indicating high electron density at Pd atoms in terraces of close-packed crystal faces, in agreement with Smoluchowski's classical model. For samples reduced at 300{degree}C our data points and those of other authors are located on a common curve of B/L vs metal dispersion. Extensive reduction at 600{degree}C results in significantly lower B/L values, attributed to the incipient formation of a palladium silicide. Oxidation followed by reduction at 300{degree}C destroys the silicide, and the B/L value returns to the original curve.

1989-06-15

163

Effects of palladium particle size and palladium silicide formation on fourier transform infrared spectra of CO adsorbed on Pd/SiO sub 2 catalysts  

Science.gov (United States)

Two major modes of CO adsorption on SiO{sub 2}-supported Pd reflect different extents of back-donation, which is, at least in part, controlled by the local electron density at the adsorption site. The fraction of CO in the bridging mode (B) increases and that of the linear mode (L) decreases, with increasing size of the Pd particles, indicating high electron density at Pd atoms in terraces of close-packed crystal faces, in agreement with Smoluchowski's classical model. For samples reduced at 300{degree}C our data points and those of other authors are located on a common curve of B/L vs metal dispersion. Extensive reduction at 600{degree}C results in significantly lower B/L values, attributed to the incipient formation of a palladium silicide. Oxidation followed by reduction at 300{degree}C destroys the silicide, and the B/L value returns to the original curve.

1989-06-15

164

A new approach towards anomalous fading correction for feldspar IRSL dating - tests on samples in field saturation  

Energy Technology Data Exchange (ETDEWEB)

Anomalous fading of the feldspar infrared stimulated luminescence (IRSL) signal hampers possibilities of using feldspar IRSL to obtain burial ages for sediments beyond the dating range of quartz optically stimulated luminescence. Here, we propose a new approach to quantify anomalous fading of the feldspar IRSL signal over geological burial times based on laboratory fading experiments. The approach builds on the description of the quantum mechanical tunnelling process recently proposed by Huntley [2006. An explanation of the power-law decay of luminescence. J. Phys. Condensed Matter 18, 1359-1365]. We show that our methods allow the construction of un-faded and natural IRSL dose-response curves as well as anomalous fading rates in field saturation. The predicted level of field saturation closely approximates the measured saturation level for five samples from fluvial deposits (Lower Rhine) known to be older than 1 Ma. The modelled anomalous ...

2008-02-15

165

A Bragg curve counter with an internal production target for the measurement of the double-differential cross-section of fragment production induced by neutrons at energies of tens of MeV  

Energy Technology Data Exchange (ETDEWEB)

A Bragg curve counter equipped with an internal production target was developed for the measurements of double-differential cross-sections of fragment production induced by neutrons at energies of tens of MeV. The internal target permitted a large detection solid angle and thus the registration of processes at low production rates. In this specific geometry, the detection solid angle depends on the emission angle and the range of the particle. Therefore the energy, atomic number, and angle of trajectory of the particle have to be taken into account for the determination of the solid angle. For the selection of events with tracks confined within a defined cylindrical volume around the detector axis, a segmented anode was applied. The double-differential cross-sections for neutron-induced production of lithium, beryllium, and boron fragments from a carbon target were measured at 0 deg. for 65 MeV neutrons. The results are in good agreement with theoretical ...

2009-11-11

166

Theoretical and experimental modelling of the gas droplet flow in premixing and pre-evaporation regions of gas turbine burners. Theoretische und experimentelle Modellierung der Gas-Tropfen-Stroemung in Vormisch-/Vorverdunstungszonen von Gasturbinenbrennern  

Energy Technology Data Exchange (ETDEWEB)

Precondition for the low-NO operation of gas turbine burners is the generation of as homogeneous as possible a gaseous fuel/air mixture. Such a burner behavior can be achieved by selective adaptation of the flow and injection. A computing model is introduced that calculates the dynamically balanced GASs/droplet flow through numerical solution of the transport equations in a curved orthogonal coordinate system. The feedback reaction of the fuel droplets to the gas phase is considered by source terms and/or sink terms. Test computations were carried out for comparison with analytical solutions from the flow mechanics and validated by comparison with measurement results. Droplet motion and evaporation were checked by means of published experimental results on single droplets. For the validation of the developed computing technique, model tests were carried out with water in place of fuel. It is pointed out that the choice of ...

1989-01-01

167

A critical look at the kinetic models of thermoluminescence-II. Non-first order kinetics  

Energy Technology Data Exchange (ETDEWEB)

Non-first order (FO) kinetics models are of three types; second order (SO), general order (GO) and mixed order (MO). It is shown that all three of these have constraints in their energy level schemes and their applicable parameter values. In nature such restrictions are not expected to exist. The thermoluminescence (TL) glow peaks produced by these models shift their position and change their shape as the trap occupancies change. Such characteristics are very unlike those found in samples of real materials. In these models, in general, retrapping predominates over recombination. It is shown that the quasi-equilibrium (QE) assumption implied in the derivation of the TL equation of these models is quite valid, thus disproving earlier workers' conclusion that QE cannot be held under retrapping dominant conditions. However notwithstanding their validity, they suffer from the shortcomings as stated ...

2005-01-07

168

Extensions to the energy system GMM model: An overview  

International Nuclear Information System (INIS)

This report describes recent extensions to the energy-systems GMM (Global Multiregional MARKAL) model undertaken by the Energy Economics Group (EEG) of the Paul Scherrer Institute (PSI) in Switzerland (hereon referred to as PSI-EEG) in the context of the SAPIENTIA project sponsored by the European Commission (DG Research) and the Swiss National Centre for Competence in Research on Climate (NCCR-Climate). GMM is a multi-regional 'bottom-up' energy-systems optimization model that endogenizes technology learning. The model has been developed and is used at PSI-EEG. The main extensions undertaken here concern the incorporation of a clusters approach to technology learning, the introduction of an improved representation of the transportation sector with emphasis on the passenger sub-sector and the implementation of marginal abatement curves for CH4 and N2O, two main non-CO2 greenhouse gases. Also, a linear ...

2005-06-12

169

Protons and glucose metabolism in shock  

Energy Technology Data Exchange (ETDEWEB)

When oxygen is limiting, animals can ferment glucose via several metabolic pathways varying in energetic efficiency and leading to various end products (such as lactate, succinate, or propionate). Because the pH dependence of H/sup +/ production by fermentation is opposite to that by hydrolysis of adenosine triphosphate formed in the fermentation, the total number of moles of protons generated is always two per mole of fermentable substrate. However, two and three times more adenosine triphosphate can be turned over per mole of protons produced in succinate and propionate fermentations, respectively, than in lactate fermentation. At its limit, this advantage would achieve the same balance between H/sup +/ production and H/sup +/ consumption during ATP cycling that is observed in aerobic metabolism, a situation observed in certain alcohol fermentations. Since proton balance during anaerobiosis is clearly adaptable, we consider possible impact ...

1983-01-01

170

Comparison of maintenance energy expenditures and growth yields among several rumen bacteria grown on continuous culture.  

Science.gov (United States)

Maintenance energy expenditures were mesured for five rumen bacteria, Selenomonas ruminantium, Butyrivibrio fibrisolvens, Bacteroides ruminicola, Megasphaera elsdenii, and Streptococcus bovis, by using a complex medium with glucose as the carbon source. Large differences (as high as 8.5-fold) in maintenance energy expenditures were seen among these bacteria. The suggestion is made that maintenance requirements could be a significant determinant of bacterial competition in the rumen. Theoretical maximum growth yields, calculated from double reciprocal plots of yield versus dilution rate, were compared to theoretical Y(ATP) values in order to estimate minimum molar adenosine 5'-triphosphate yields from glucose for each bacterium. Results showed that relative yield among the bacteria was growth rate dependent. At high dilution rates, both S. ruminantium and S. bovis produced lactate as their principal fermentation product. At lower dilution rates very little ...

1979-03-01

171

Omaha childhood blood lead and environmental lead: a linear total exposure model  

Energy Technology Data Exchange (ETDEWEB)

The majority of experimental and population studies of blood lead (PbB) and environmental lead, including the Omaha study, have utilized the Goldsmith-Hexter log-log or power function model. Comparison was made of the log-log model and a linear model of total exposure as they described the Omaha Study of 1074 PbBs from children ages 1-18 years as related to air (PbA), soil (PbS), and housedust (PbHD) lead. The data fit of the linear model was statistically equivalent to the power model and the predicted curves were biologically more plausible. The linear model avoids the mathematical limitations of the power model which predicts PbB zero at PbA zero. From the Omaha data, this model, ln PbB = ln (..beta../sub 0/ + B/sub 1/ PbA + B/sub 2/ PbS + ..beta../sub 3/ PbHD) predicts that PbB increases 1.92 ...

1984-10-01

172

Volume IIr - NASA Technical Report Server (NTRS)  

Science.gov (United States)

f4. HRS. 65. 119 HRS. Figure 2-39. Space Processing Shared Flows ..... Learning Curve: An 80 percent learning curve will be used to extrap ...

173

The Environmental Kuznets Curve. An empirical analysis for OECD countries  

Energy Technology Data Exchange (ETDEWEB)

This paper tests the Environmental Kuznets Curve hypothesis for four local (SOx, NOx, CO, VOC) and two global (CO2, GHG) air pollutants. Using a new panel data set of thirty OECD countries, the paper finds that the postulated inverted U-shaped relationship between income and pollution does not hold for all gases. A meaningful Environmental Kuznets Curve exists only for CO, VOC and NOx, where for CO2 the curve is monotonically increasing. For GHG there is indication of an inverted U-shaped relationship between income and pollution, but still most countries are on the increasing path of the curve and hence the future development of the curve is uncertain. For SOx it was found that emissions follow an U-shaped curve. Based on the empirical results, the paper concludes that the Environmental Kuznets Curve does not hold for all gases, it is ...

2008-09-15

174

The Environmental Kuznets Curve. An empirical analysis for OECD countries  

International Nuclear Information System (INIS)

This paper tests the Environmental Kuznets Curve hypothesis for four local (SOx, NOx, CO, VOC) and two global (CO2, GHG) air pollutants. Using a new panel data set of thirty OECD countries, the paper finds that the postulated inverted U-shaped relationship between income and pollution does not hold for all gases. A meaningful Environmental Kuznets Curve exists only for CO, VOC and NOx, where for CO2 the curve is monotonically increasing. For GHG there is indication of an inverted U-shaped relationship between income and pollution, but still most countries are on the increasing path of the curve and hence the future development of the curve is uncertain. For SOx it was found that emissions follow an U-shaped curve. Based on the empirical results, the paper concludes that the Environmental Kuznets Curve does not hold for all gases, it is ...

2008-01-01

175

The Deep Space Network Progress Report 42-39 - NASA Technical ...  

Science.gov (United States)

C. Learning Curve. The learning curve concept has long been recognized and ...... F4. TERMIA. S - STATION EQUIPMENT. V - VLBI VALIDATION EQUIPMENT ...

176

T. I --. - NASA Technical Report Server (NTRS)  

Science.gov (United States)

curves are also directly translatable to metal-matrix composites. ..... 4~f4'4 ..... result of learning curve. The most important reduction in cost as a ...

177

Osteocyte death and hip fracture.  

Science.gov (United States)

The viability of osteocytes can be demonstrated in sawn decalcified sections of bone by their lactate dehydrogenase activity. In the cancellous bone of the femoral head, the proportion of lacunae containing viable osteocytes decreased from 88 +/- 7% (mean +/- SD) at 10-29 years to 58 +/- 12% (P Ultimate compressive strength did not correlate with osteocyte viability. In the femoral head there is gradual, age-related reduction in osteocyte viability that can be more pronounced in hip fracture. Osteocyte death may affect bone quality by impairing repair of fatigue damage. PMID:8275364

1993-01-01

178

"1H MR spectroscopy in pediatrics  

International Nuclear Information System (INIS)

Spectral appearance and concentrations of the most prominent metabolites are affected by brain development. This knowledge is essential for the detection of pathological changes in pediatric patients. This paper discusses specific conditions of MR spectroscopic examination of children and the effects of age on MR spectra quality and quantitation of the studied metabolites. Clinical examples show several diseases that are reflected in changes in "1H MR spectra due to pathological alterations in the biochemical pathways of the observed metabolites. Attention is given to the main metabolites such as N-acetylaspartate, creatine/phosphocreatine, cholines, lactate, inositol, etc.

2008-08-01

179

The pisa experiment: spallation products identified by bragg curve spectroscopy  

International Nuclear Information System (INIS)

In the framework of spallation neutron sources and accelerator-driven systems, the international PISA (Proton-induced Spallation) collaboration has initiated measurements of total- and double-differential cross-sections for products of spallation reactions in a wide range of target nuclei (GU) at the COSY proton accelerator in Julich (Germany). The purpose is to study secondary particle production created in structural, window and target materials via proton beams up to 2.5 GeV of incident kinetic energy. Residual nuclei [H, He up to intermediate mass fragment (IMF)] production cross-sections are of great importance for estimating the damage to target and structure materials involving the planned spallation neutron sources, given that the lifetime of window and target materials is directly associated to those cross-sections. The demand for reliable theoretical predictions on production cross-sections is by no means satisfied by the models and codes that are ...

2004-05-17

180

Effect of energy intake on the metabolism of glucose and glutamine in rumen epithelial tissue  

International Nuclear Information System (INIS)

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 ...

1986-04-13

181

Comparison of medetomidine and fentanyl-droperidol in dogs: sedation, analgesia, arterial blood gases and lactate levels.  

Science.gov (United States)

Medetomidine and fentanyl-droperidol (Innovar-vet) were assessed over a three hour period in 80 healthy dogs. Following physical examination, electrocardiogram (ECG), arterial blood sample analysis, and dynamometer pressure threshold (analgesia score), the dogs were randomly assigned to one of four treatments: Miv--medetomidine (750 micrograms/M2) administered intravenously (IV), Mim--medetomidine (1000 micrograms/M2) administered intramuscularly (IM), Iiv--Innovar-vet IV (0.05 mL/kg) or Iim--Innovar-vet IM (0.1 mL/kg). All assessments were carried out by a single individual unaware of the treatment used. Objective assessments included temperature, heart and respiratory rates, analgesia score, arterial blood gases, acid-base and lactate levels. Subjective evaluation included degree of sedation, response to various clinical procedures, noise responsiveness, posture, and the incidence of side effects. Onset and duration of effect were also recorded. The ECG strips ...

1993-04-01

182

Well Test Analysis in Naturally Fissured, Geothermal Reservoirs with Fracture Skin  

Science.gov (United States)

Mineral deposition or alteration is commonly found at fracture-block interfaces is fissured, geothermal reservoirs. In response to pressure reduction in the fissures such mineralization, if less permeable than the matrix rock, will retard the flow of fluid from the blocks to the fissures and is termed fracture skin in this paper. The problem of fluid flow to a production well in a double-porosity reservoir with fracture skin was analyzed theoretically. One of the findings of the analysis was that fully transient block-to-fissure flow can be approximated by pseudo-steady state flow if fracture skin permeability is sufficiently low. Type curves generated by numerical inversion of Laplace transform solutions are used to cooroborate the results of a finite-difference model of steam transport to a well in a naturally fissured, geothermal reservoir with fracture skin.

1983-12-15

183

The influence of heating rate on the response and trapping parameters of {alpha}-Al{sub 2}O{sub 3}:C  

Energy Technology Data Exchange (ETDEWEB)

The effects of the heating rate from 0.6 up to 50{sup o}C.s{sup -1} on the thermoluminescence of {alpha}-Al{sub 2}O{sub 3}:C are very intensive. The material rapidly loses its high sensitivity as the heating rate increases. The peak shape characteristics, peak maximum and full width at half maximum agree only qualitatively with those theoretically predicted. The trapping parameters calculated by the curve fitting method, the peak shape method, the variable heating rate method and the initial rise method, were found to decrease as the heating rate increases. The validity of the results are discussed in the framework of the kinetic models. (author).

1994-12-31

184

The influence of heating rate on the response and trapping parameters of #alpha#-Al_2O_3:C  

International Nuclear Information System (INIS)

The effects of the heating rate from 0.6 up to 50"oC.s"-"1 on the thermoluminescence of #alpha#-Al_2O_3:C are very intensive. The material rapidly loses its high sensitivity as the heating rate increases. The peak shape characteristics, peak maximum and full width at half maximum agree only qualitatively with those theoretically predicted. The trapping parameters calculated by the curve fitting method, the peak shape method, the variable heating rate method and the initial rise method, were found to decrease as the heating rate increases. The validity of the results are discussed in the framework of the kinetic models. (author).

185

Study on fracture behaviour of Al?15%Mg2Si metal matrix composite with and without beryllium additions  

British Library Electronic Table of Contents (United Kingdom)

In this study, the influence of Beryllium (Be) content on the fracture behaviour of Al?15%Mg2Si composite was investigated. The results showed an increase in mechanical properties with increasing of Be content. The stress?strain curves of samples showed a same category of serrations reflecting non-uniform deformation. Scanning electron microscopy was employed to examine the crack nucleation and fracture model. The results indicate that Al?15%Mg2Si composite shows different behaviours of crack initiation and fracture for samples with and without Be. Differences observed in the fracture behaviour were attributed to microstructural changes as well as morphological aspects of primary Mg2Si particles.

2011-01-01

186

Studies on the diagnostic accuracy of lymphography  

International Nuclear Information System (INIS)

Contradictory reports in the literature on the reliability of lymphography stimulated the authors to test the diagnostic accuracy, employing methods which are approximately analogous to practice, using carcinoma of the cervix as the model on which the study was carried out. Using 21 observers it was found that there was no correlation between their experience and on-target accuracy of the diagnosis. Good observers obtained an accuracy of 85% with good proportions between sensitivity in the recognition of detail, specificity and readiness to arrive at a decision on the basis of discriminatory ability. With the help of the concept of the ROC curves, the position taken up by the observers in respect of diagnostic decisions, and a complex manner of assessing the various characteristic factors determining diagnostic accuracy, are demonstrated. This form of test, which permits manipulation of different variants of diagnosis, is recommended, among ...

187

Stepping, Strain Gating, and an Unexpected Force-Velocity Curve for Multiple-Motor-Based Transport  

British Library Electronic Table of Contents (United Kingdom)

SummaryBackground Intracellular transport via processive kinesin, dynein, and myosin molecular motors plays an important role in maintaining cell structure and function. In many cases, cargoes move distances longer than expected for single motors; there is significant evidence that this increased travel is in part due to multiple motors working together to move the cargoes. Although we understand single motors experimentally and theoretically, our understanding of multiple motors working together is less developed. Results We theoretically investigate how multiple kinesin motors function. Our model includes stochastic fluctuations of each motor as it proceeds through its enzymatic cycle. Motors dynamically influence each other and function in the presence of thermal noise and viscosity. We...

2008-01-01

188

Residual stresses in darrieus vertical axis wind turbine blades  

Energy Technology Data Exchange (ETDEWEB)

A numerical package called RESID has been assembled to calculate the residual stresses in VAWT blades induced during cold forming. Using a strength of materials - elementary beam theory approach, RESID models the material response with a bilinear stress-strain curve, and the cross-sectional geometry with an array of area increments. Through an iterative solution procedure residual stresses are predicted for a specified final radius of curvature or applied bending moment. RESID results are compared to theoretical solutions for simple geometries and with MARC Finite element results for VAWT blade geometries. Calculating residual stress levels, determining acceptable residual stress levels, and a method of reducing residual stresses are discussed. A complete listing and sample run are included in the appendicies.

1981-04-01

189

Reporting bias when using real data sets to analyze classification performance  

British Library Electronic Table of Contents (United Kingdom)

Motivation: It is commonplace for authors to propose a new classification rule, either the operator construction part or feature selection, and demonstrate its performance on real data sets, which often come from high-dimensional studies, such as from gene-expression microarrays, with small samples. Owing to the variability in feature selection and error estimation, individual reported performances are highly imprecise. Hence, if only the best test results are reported, then these will be biased relative to the overall performance of the proposed procedure. Results: This article characterizes reporting bias with several statistics and computes these statistics in a large simulation study using both modeled and real data. The results appear as curves giving the different reporting biases as...

2010-01-01

190

Relating Complex Fluid Composition and Thermophysical Properties with the Advanced Distillation Curve Approach  

British Library Electronic Table of Contents (United Kingdom)

Complex fluids have long posed a significant challenge in our ability to characterize and model fluid properties. Here, we consider complex fluids to be mixtures with many components that can differ significantly in polarity and polarizability. The penultimate complex fluid is crude oil, although many other fluids such as finished fuels are also highly complex. We have recently introduced a measurement strategy that can simplify these efforts and provides the added potential of linking chemical composition (i.e. analytical) information with physical property information. In addition to chemical characterization, the approach provides the ability to calculate thermodynamic and transport properties for such complex heterogeneous streams. The technique is based on the advanced distillation cu...

2010-01-01

191

Power from triticale straw  

Energy Technology Data Exchange (ETDEWEB)

This study examined the feasibility of using triticale straw for production of electricity in Canada. Triticale is a manmade hybrid of wheat and rye and it has a high potential of growth in Canada. The cost ($/MWh) of producing electricity from triticale straw was estimated using a data intensive techno-economic model. The study also determined the optimum size of a biomass power plant (MW) which is a trade-off between capital cost of the plant and transportation cost of biomass. Cost curves were also developed in order to evaluate the impact of scale on power production costs. The location of the power plant and the future expansion of triticale were among the factors considered in the techno-economic mode. The scope of the work included all the processes beginning with the collection of straw to the conversion to electricity through direct combustion at the power plant. According to the preliminary results, the cost of producing power from ...

2010-07-01

192

Mode shape and natural frequency identification for seismic analysis from background vibration  

International Nuclear Information System (INIS)

Background vibration in a CANDU plant can be used to determine the dynamic characteristics of major items of equipment, such as calandria, the fuelling machines and the primary heat transport pumps. These dynamic characteristics can then be used to verify the seismic response of the equipment which, at present, is based on theoretical models only. The feasibility and basic theory of this new approach (which uses accelerations measured at several points on a structure and does not require knowledge of the source of excitation) was established in Phase I of the study. This report is based on Phase II in which the methods of analysis developed in Phase I were improved and verified experimentally. A Fast Fourier Transform (FFT) algorithm was incorporated and an interactive curve fitting technique was developed to obtain the dynamic characteristics in the form of natural frequencies, mode shapes and damping ratios. The method is now available for ...

1984-02-06

193

Memory of multiple aging stages above the freezing temperature in the Relaxor ferroelectric PLZT.  

Science.gov (United States)

The dynamic dielectric susceptibility and the elastic compliance of the relaxor ferroelectric lanthanum lead zirconate titanate (PLZT) 9/65/35 have been measured under different cooling and heating protocols in order to study aging and memory. The memory of multiple aging stages at different temperatures has been found (several dips in the susceptibility curves on heating), as in spin glass systems below the glass transition. Remarkably, in PLZT the memory of several aging stages is retained also above the freezing temperature deduced from the dynamic susceptibilities. The results are discussed in light of the existing models of aging and memory in spin and dipolar glasses. PMID:15447139

2004-08-24

194

Kinetics of pore coarsening in glassy carbon  

Energy Technology Data Exchange (ETDEWEB)

One third of the microstructure of glassy carbon (GC) consists of closed pores. Density measurements indicate that the total pore volume depends only on the heat treatment temperature and not on the heat treatment time, a characteristic of coarsening. The kinetics of coarsening of these pores on heat treatment has been investigated by analyzing the changes in specific surface area of the pores as determined by the small angle X-ray scattering (SAXS) technique. A part of the surface area change is due to thermal expansion induced microcracking. Both the superposition method after correcting the thermal expansion induced surface area change and the curve fitting method give an activation energy of 64 +/- 10 kcal/mole. This value is compared with the activation energies of various rate processes in graphite. A model of coarsening of the pores based on a vacancy migration mechanism is proposed.

1981-01-01

195

Influence of pH on electrochemical properties of passive films formed on Alloy 690 in high temperature aqueous environments  

Energy Technology Data Exchange (ETDEWEB)

Passive films formed on Alloy 690 in different pH solutions at high temperatures were studied by potentiodynamic polarization, Auger electron spectroscopy, thermodynamic diagrams and the Mott-Schottky relation. The chemical compositions and electronic structures of the passive films were found to be strongly pH-dependent. In alkaline solutions, a secondary passivation was clearly observed on potentiodynamic polarization curves. The passive films were a mixture of Cr{sub 2}O{sub 3} and FeCr{sub 2}O{sub 4} below the flat band potential of nickel oxide and were NiFe{sub 2}O{sub 4} above this potential. Electronic structure models, describing the electrochemical properties of the passive films, are proposed and discussed.

2009-12-15

196

Influence of pH on electrochemical properties of passive films formed on Alloy 690 in high temperature aqueous environments  

International Nuclear Information System (INIS)

Passive films formed on Alloy 690 in different pH solutions at high temperatures were studied by potentiodynamic polarization, Auger electron spectroscopy, thermodynamic diagrams and the Mott-Schottky relation. The chemical compositions and electronic structures of the passive films were found to be strongly pH-dependent. In alkaline solutions, a secondary passivation was clearly observed on potentiodynamic polarization curves. The passive films were a mixture of Cr2O3 and FeCr2O4 below the flat band potential of nickel oxide and were NiFe2O4 above this potential. Electronic structure models, describing the electrochemical properties of the passive films, are proposed and discussed.

2009-12-01

197

Impedance Spectra of Mixed Conductors: a 2D Study of Ceria  

CERN Document Server

In this paper we develop an analytical framework for the study of electrochemical impedance of mixed ionic and electronic conductors (MIEC). The framework is based on first-principles and it features the coupling of electrochemical reactions, surface transport and bulk transport processes. We utilize this work to analyze two dimensional systems relevant for fuel cell science via finite element method (FEM). Alternate current Impedance Spectroscopy (IS) of a ceria symmetric cell is simulated near equilibrium condition (zero bias) for a wide array of working conditions including variations of temperature and $H_2$ partial pressure on a two dimensional fuel cell sample with patterned metal electrodes. The model shows agreement of IS curves with the experimental literature with the relative error on the impedance being consistently below 2%. Important two-dimensional effects such the effects of thickness decrease and the influence of variable ...

2009-01-01

198

Electron transport through asymmetric DNA molecules  

British Library Electronic Table of Contents (United Kingdom)

We investigate quantum mechanical electron transport along the long axis of the DNA molecule using an effective tight-binding model. The overall contour plot of transmission, the current-voltage characteristics, and the differential conductance are examined for the variation of backbone onsite energy, the energy-dependent hopping strength, and the contact coupling between the leads and the DNA molecule. It is shown that as backbone asymmetry increases, the merging and collapse of the two mini-bands take place and an extra resonance peak in the transmission appears. In addition, we present the modulation of voltage threshold in the current-voltage curves and a double-peak structure in the differential conductance due to the disappearance of the merged mini-band. Finally, in the Coulomb bloc...

2010-01-01

199

Dynamic control rod worth measurement of Yonggwang Unit 1 cycle 14  

Energy Technology Data Exchange (ETDEWEB)

A dynamic control rod worth measurement was performed for control bank D, C, B, and A of Yonggwang unit 1 cycle 14 during its low power physics test. MASTER was used for three-dimensional core kinetics calculations required to convert excore detector signal into static rod worth, using the same modeling and cross sections as ANC which was used for the core static design. A signal curve fitting method was proposed to solve a low signal problem due to large amount of rod worth, which leads to the distortion of resulting static worth. The static worths measured in this test well agreed with the predicted worth of design within {+-}15% which is a test requirement of rod worth measurement.

2002-05-01

200

Dynamic control rod worth measurement of Yonggwang Unit 1 cycle 14  

International Nuclear Information System (INIS)

A dynamic control rod worth measurement was performed for control bank D, C, B, and A of Yonggwang unit 1 cycle 14 during its low power physics test. MASTER was used for three-dimensional core kinetics calculations required to convert excore detector signal into static rod worth, using the same modeling and cross sections as ANC which was used for the core static design. A signal curve fitting method was proposed to solve a low signal problem due to large amount of rod worth, which leads to the distortion of resulting static worth. The static worths measured in this test well agreed with the predicted worth of design within #+-#15% which is a test requirement of rod worth measurement.

2002-05-01

201

Declining inter-industry wage dispersion in the US  

British Library Electronic Table of Contents (United Kingdom)

Industrial effects have long been significant factors in wage inequality. Previous research indicates that wage differentials across industries were increasing through the mid 1980s. Using more recent data, however, we find that the level of inter-industry wage dispersion declined by 36% from 1986 to 2002 despite the continued trend towards increasing inequality in the labor force. This decline in inter-industry wage dispersion is evident across gender and educational groups. Using multilevel growth curve models, our multivariate results indicate that the decline is only weakly related to industrial changes in education, occupation or even productivity despite the fact that the latter variable had been a critical factor in the prior period. Indicators of globalization and downsizing also d...

2008-01-01

202

Contribution of several mechanisms to the alpha particle elastic scattering in the angle range near 180 deg  

International Nuclear Information System (INIS)

The contribution of exchange processes (heavy stripping and substitution) into the amplitude of the 25-30 MeV #alpha#-particle elastic scattering by "1"2C and "4"0Ca nuclei is examined taking into account the distortion of plane waves of initial and finite particles. The eikonal approximation is used for accounting for distortions. The matrix elements of exchange processes are calculated. The results of calculations show that the Wronskian cutoff radii are close to those which have been obtained for calculation of exchange processes in the plane-wave approximation. The moduli of the values defining the contribution of exchange processes to the total S matrix are plotted. Also presented are Argand diagrams and angular distributions for both reactions. It has been established that the account for exchange processes improves the agreement of theoretical curves with the experiment in the whole range of angles, as compared with the optical model.

203

Simultaneous biosorption of chromium(VI) and copper(II) on Rhizopus arrhizus in packed column reactor: Application of the competitive Freundlich model  

Energy Technology Data Exchange (ETDEWEB)

The simultaneous biosorption of Cr(VI) and Cu(II) on free Rhizopus arrhizus in a packed column operated in the continuous mode was investigated and compared to the single metal ion situation. The breakthrough curves were measured as a function of feed flow rate, feed pH, and different combinations of metal ion concentrations in the feed solutions. Column competitive biosorption data were evaluated in terms of the maximum (equilibrium) capacity in the column, the amount of metal loading on the R. arrhizus surface, the adsorption yield, and the total adsorption yield. In the single-ion situation the adsorption isotherms were developed for optimum conditions, and it was seen that the adsorption equilibrium data fit the noncompetitive Freundlich model. For the multicomponent adsorption equilibrium the competitive adsorption isotherms were also developed. The competitive Freundlich model for binary metal mixtures represented ...

1999-12-01

204

Evolution of spiral galaxies in modified gravity  

CERN Document Server

We compare N-body simulations of isolated galaxies performed in both frameworks of modified Newtonian dynamics (MOND) and Newtonian gravity with dark matter (DM). We have developed a multigrid code able to efficiently solve the modified Poisson equation derived from the Lagrangian formalism AQUAL. We take particular care of the boundary conditions that are a crucial point in MOND. The 3-dimensional dynamics of initially identical stellar discs is studied in both models. In Newtonian gravity the live DM halo is chosen to fit the rotation curve of the MOND galaxy. For the same value of the Toomre parameter (Q_T), galactic discs in MOND develop a bar instability sooner than in the DM model. In a second phase the MOND bars weaken while the DM bars continue to grow by exchanging angular momentum with the halo. The bar pattern speed evolves quite differently in the two models: there is no dynamical friction ...

2007-01-01

205

Biosorption of Acid Red 274 (AR 274) on Enteromorpha prolifera in a batch system  

Energy Technology Data Exchange (ETDEWEB)

The biosorption of Acid Red 274 (AR 274) dye on Enteromorpha prolifera, a green algae grown on Mersin costs of the Mediterranean, Turkey, was studied as a function of initial pH, temperature, initial dye and biosorbent concentration. The experiments were conducted in a batch manner. The Langmuir and Freundlich isotherms were used for modelling the biosorption equilibrium. At optimum temperature 30 deg C and initial pH 2.0-3.0, the Langmuir isotherm fits best to the experimental equilibrium data with a maximum monolayer coverage of 244 mg/g. The equilibrium AR 274 concentration of the exit stream of a single batch was also obtained by using the experimental equilibrium curve and operating line graphically. The pseudosecond-order kinetic model and Weber-Morris model were applied to the experimental data and it was found that both the surface adsorption as well as intraparticle diffusion contribute to the ...

2005-11-11

206

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

DEFF Research Database (Denmark)

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

1997-01-01

207

True potential energy curve and dissociation energy of BeO  

International Nuclear Information System (INIS)

The true potential energy curve for the x "1#SIGMA#"+ state of BeO has been calculated using the RKRV method. The dissociation energy of the ground state has been estimated to be 5.15 +- 0.05 eV by the curve-fitting method using the three-parameter potential energy function of Lippincott with an RKRV potential energy curve. (author).

210

Environmental Economics  

Wastenet

environmental burden is studied by testing the Environmental Kuznets Curve hypothesis as well as application of statistical decomposition

212

Effects of organic and inorganic lead on the oxygen equilibrium curves of the fresh water field crab, Barytelphusa guerini  

Energy Technology Data Exchange (ETDEWEB)

Haemocyanin serves as normal transporter of oxygen in many Arthropods. The oxygen equilibrium curves have been described for the haemocyanins of many Arthropods and Molluscs. Oxygen equilibrium curves of the blood reveal the relationship between the oxygen tension and the percentage saturation of the haemocyanin. The shape of the oxygen equilibrium curves vary in position from sigmoid to hyperbolic in different animals or even undulatory as shown in some chitons. Oxygen equilibrium curves are known to be influenced by pH, temperature and inorganic ions. The effect of environmental pollutants like the heavy metals on the oxygen equilibrium curves of the fresh water crab has not been previously reported. One of the toxic heavy metals with regard to aquatic organisms is lead. Hence the present study was designed to determine the effect of organic and inorganic lead on the oxygen ...

1989-02-01

213

Approximate convolution with pairs of cubic B?zier LN curves  

British Library Electronic Table of Contents (United Kingdom)

In this paper we present an approximation method for the convolution of two planar curves using pairs of compatible cubic B?zier curves with linear normals (LN). We characterize the necessary and sufficient conditions for two compatible cubic B?zier LN curves with the same linear normal map to exist. Using this characterization, we obtain the cubic spline approximation of the convolution curve. As illustration, we apply our method to the approximation of a font where the letters are constructed as the Minkowski sum of two planar curves. We also present numerical results using our approximation method for offset curves and compare our method to previous results.

2011-01-01

214

Theory of mirror machines at high beta  

Science.gov (United States)

The kinetic and guiding center fluid theories of high-..beta.. plasma containment in mirror machines have been developed in a number of self-consistent models. The geometrical effects of magnetic field and ambipolar potential variation have been incorporated in a bounce-averaged Fokker-Planck code which shows that the square-well model somewhat overestimates the n tau and ..beta.. achievable in a mirror field. Simple analytic approximations to the resulting pressure profiles have been incorporated in three-dimensional fluid-equilibrium codes which show the effect of coil geometry on the maximum ..beta... Strongly curved vacuum fields allow higher ..beta.., but short plasmas in weakly curved fields tend to reverse the curvature locally before the mirror-mode limit is reached. Adiabaticity of particle orbits is described in terms of general formulas, applicable in high-..beta.. plasma equilibria, and is ...

1976-08-06

215

Monte Carlo simulation and scatter correction of the GE Advance PET scanner with SimSET and Geant4  

Energy Technology Data Exchange (ETDEWEB)

For Monte Carlo simulations to be used as an alternative solution to perform scatter correction, accurate modelling of the scanner as well as speed is paramount. General-purpose Monte Carlo packages (Geant4, EGS, MCNP) allow a detailed description of the scanner but are not efficient at simulating voxel-based geometries (patient images). On the other hand, dedicated codes (SimSET, PETSIM) will perform well for voxel-based objects but will be poor in their capacity of simulating complex geometries such as a PET scanner. The approach adopted in this work was to couple a dedicated code (SimSET) with a general-purpose package (Geant4) to have the efficiency of the former and the capabilities of the latter. The combined SimSET+Geant4 code (SimG4) was assessed on the GE Advance PET scanner and compared to the use of SimSET only. A better description of the resolution and sensitivity of the scanner and of the scatter fraction was obtained with SimG4. The accuracy of ...

2005-10-21

216

Luminescence and laser transition studies of Dy3+:K-Mg-Al fluorophosphate glasses  

International Nuclear Information System (INIS)

Dysprosium ion doped fluorophosphate glasses with compositions of PKMAFDy: (56-x/2) P2O5+17K2O+8Al2O3+(15-x/2)MgO+4AlF3+xDy2O3 (x=0.01, 0.05, 0.1, 1.0 and 2.0 mol%) have been prepared by melt quenching technique and are characterized by optical absorption, emission spectra and fluorescence lifetime measurements. The observed bands in the absorption spectrum are analysed by using free-ion Hamiltonian (HFI) model. The Judd-Ofelt (JO) analysis has been performed and the intensity parameters (??, ?=2, 4, 6) have been evaluated that are used to predict radiative properties. From emission spectra, the effective bandwidth (??eff) and the stimulated emission cross-section (?(?p)) were evaluated. The fluorescence decay from the 4F9/2 level of Dy3+ ions have been measured by monitoring the intense 4F9/2#->#6H13/2 transition (573 nm). The lifetimes (?) are found to decrease with increasing concentration due to concentration quenching. The decay curves ...

2009-02-28

217

Thermodynamic prediction of distribution coefficients for the solvent extraction of the rare earth metals  

International Nuclear Information System (INIS)

A thermodynamic model for predicting the distribution coefficients has been developed by taking into account the extraction mechanism and the chloride complexation when Sm, Eu, Gd, Tb, Dy and Ho for single component systems are extracted from acidic chloride solutions by di-2-ethylhexyl ester in kerosene, respectively. The model equation includes two constants, of which one corresponds to the apparent extraction equilibrium constant and the other is due to the variation of the activity coefficients of organic species. These values are determined from a few experimental data by the curve fitting method. Then, the distribution coefficients under untried calculations, Bromley's formulation is used to estimate the activity coefficients of aqueous species and the interaction parameters for some rare earth chlorides are reported in terms of morality and molarity using data from Spedding et al. According to the authors the ...

218

Research in heavy-ion nuclear physics. [Dept. of Physics and Astronomy, The Univ. of Kansas, Lawrence, Kansas  

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.

1992-01-01

219

Research in heavy-ion nuclear physics. Annual progress report, May 1, 1992--April 30, 1993  

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.

1992-01-01

220

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

Energy Technology Data Exchange (ETDEWEB)

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

1995-01-30

221

KINEMATICS AT THE EDGE OF THE GALACTIC BULGE: EVIDENCE FOR CYLINDRICAL ROTATION  

International Nuclear Information System (INIS)

We present new results from BRAVA, a large-scale radial velocity survey of the Galactic bulge, using M giant stars selected from the Two Micron All Sky Survey catalog as targets for the Cerro Tololo Inter-American Observatory 4 m Hydra multi-object spectrograph. The purpose of this survey is to construct a new generation of self-consistent bar models that conform to these observations. We report the dynamics for fields at the edge of the Galactic bulge at latitudes b = -8 deg. and compare to the dynamics at b = -4 deg. We find that the rotation curve V(r) is the same at b = -8 deg. as at b = -4 deg. That is, the Galactic boxy bulge rotates cylindrically, as do boxy bulges of other galaxies. The summed line-of-sight velocity distribution at b = -8 deg. is Gaussian, and the binned longitude-velocity plot shows no evidence for either a (disk) population with cold dynamics or for a (classical bulge) population with hot dynamics. The observed ...

2009-09-10

222

Jet initiation and penetration of explosives  

Energy Technology Data Exchange (ETDEWEB)

The two-dimensional Eulerian hydrodynamic code 2DE, with the shock initiation of heterogeneous explosive burn model called Forest Fire, is used to model numerically the interaction of jets of steel, copper, tantalum, aluminum, and water with steel, water, and explosive targets. The calculated and experimental critical condition for propagating detonation may be described by the Held V/sup 2/d expression (jet velocity squared times the jet diameter). In PBX 9502, jets initiate an overdriven detonation smaller than the critical diameter, which either fails or enlarges to greater than the critical diameter while the overdriven detonation decays to the C-J state. In PBX 9404, the jet initiates a detonation that propagates only if it is maintained by the jet for an interval sufficient to establish a stable curved detonation front. The calculated penetration velocities into explosives, initiated by a low-velocity jet, are ...

1983-01-01

223

Jet initiation and penetration of explosives  

Energy Technology Data Exchange (ETDEWEB)

The two-dimensional Eulerian hydrodynamic code 2DE with the shock initiation of heterogeneous explosive burn model called Forest Fire, is used to model numerically the interaction of jets of steel, copper, tantalum, aluminum, and water with steel, water, and explosive targets. The calculated and experimental critical condition for propagating detonation may be described by the Held V/sup 2/d expression (jet velocity squared times the jet diameter). In PBX 9502, jets initiate an overdriven detonation smaller than the critical diameter, which either fails or enlarges to greater than the critical diameter while the overdriven detonation decays to the C-J state. In PBX 9404, the jet initiates a detonation that propagates only if it is maintained by the jet for an interval sufficient to establish a stable curved detonation front. The calculated penetration velocities into explosives, initiated by a low-velocity jet, are ...

1983-01-01

224

Estimation of the detection limit of an experimental model of tritium storage bed designed for 'in-situ' accountability  

International Nuclear Information System (INIS)

During the water detritiation process most of the tritium inventory is transferred from water into the gaseous phase, then it is further enriched and finally extracted and safely stored. The control of tritium inventory is an acute issue from several points of view: - Financially - tritium is an expensive material; - Safeguard - tritium is considered as nuclear material of strategic importance; - Safety - tritium is a radioactive material: requirements for documented safety analysis report (to ensure strict limits on the total tritium allowed) and for evaluation of accident consequences associated with that inventory. Large amounts of tritium can be stored, in a very safely manner, as metal tritides. A bench-scale experiment of a tritium storage bed with integrated system for in-situ tritium inventory accountancy was designed and developed at ICSI Rm. Valcea. The calibration curve and the detection limit for this experimental model of tritium ...

2009-10-12

225

Effect of site wind properties on wind-electric conversion costs  

Energy Technology Data Exchange (ETDEWEB)

The unit cost of energy production of wind generators is examined by means of a model of the turbine power curve and the Weibull model of wind probability function, by applying the usual economic equations. The analysis is carried out in terms of dimensionless variables whose range of variability is defined by examining the data of 80 modern commercial wind turbines; likewise, the economic parameters are based on the present state of costs. The unit cost decreases asymptotically when alpha (ratio between mean wind speed and cut-in speed) - increases and shows a lower limit of 2 to 5 Ecent/kWh. This cost depends both on the value of the machine parameter {phi} (ratio between nominal and cut-in speed) and on the basic prices. The effect of the Weibull shape parameter kappa is different according to the values of {alpha} and {phi}: with low {alpha} and high {phi} the unit cost increases along with {kappa} (that is with the ...

2004-12-01

226

Behavior of instrumented model batter piles in clay  

Energy Technology Data Exchange (ETDEWEB)

Pile foundations in several coastal and offshore structures are subjected to significant amounts of lateral loads due to wave action. Usually batter piles are adopted to resist large lateral loads. In this investigation an attempt has been made to study the behavior of batter pile in clayey soils through an experimental program carried out on instrumented model aluminium piles of 26 mm diameter in a test tank of size, 1,200 mm x 800mm x 1,100 mm. The pile was instrumented with electrical resistance type strain gauges to determine the bending moment variations along the depth of embedment of pile. Bending moment vis depth relationships were used to determine the Soil reaction (p) and lateral displacement (y) along the length of the pile for the applied load. From the bending moment vs depth curves it is found that depth of maximum bending moment is greater for negative batter pile than for vertical and positive batter pile. The data of soil ...

1995-12-31

227

Assessment of dose-time-effect surfaces for somatic late effects after low dose irradiation  

International Nuclear Information System (INIS)

Awaiting new data from RERF, an attempt was made to estimate the somatic risks of low doses of radiation for members of the German public. The new estimate follows closely the approach used in deriving the values published in the NIH Radioepidemiological Tables. The lifetime risk factors thus calculated are significantly larger than the estimates presented in ICRP Report 26 and are consistent with estimates recently made in the ongoing reactor safety study of NUREG. The increase in lifetime risks is mainly due to the introduction of a new time projection model which appears to be more consistent with the epidemiological data for many late effect end points than the constant absolute risk model previously employed. Results from a study in which epidemiological data were stochastically simulated with a computer indicate that the shapes of actual dose effect curves might be significantly more influenced by pure chance than by ...

1988-04-01

228

Analysis of reverse flow in inverted U-tubes of steam generator under natural circulation condition  

International Nuclear Information System (INIS)

In this paper, we report on the analysis of reverse flow in inverted U-tubes of a steam generator under natural circulation condition. The mechanism of reverse flow in inverted U-tubes of the steam generator with natural circulation is graphically analyzed by using the full-range characteristic curve of parallel U-tubes. The mathematical model and numerical calculation method for analyzing the reverse flow in inverted U-tubes of the steam generator with natural circulation have been developed. The reverse flow in an inverted U-tube steam generator of a simulated pressurized water reactor with natural circulation in analyzed. Through the calculation, the mass flow rates of normal and reverse flows in individual U-tubes are obtained. The predicted sharp drop of the fluid temperature in the inlet plenum of the steam generator due to reverse flow agrees very well with the experimental data. This indicates that the developed mathematical ...

2008-12-01

229

Corrosion inhibition of steel in crude oil storage tanks  

Energy Technology Data Exchange (ETDEWEB)

The corrosion behavior of steel in water from certain oil fields with various organic inhibitors was studied by applying potentiodynamic technique at pH 5.9. The inhibitors which were used include 2-methylbenzimidazole (I), 2-mercaptobenzimidazole (II), 2-mercapto-5-methylbenzimidazole (III), and 2-mercaptothiazole (IV). The inhibiting efficiency of the different additives was evaluated from their anodic and cathodic polarization curves at different temperatures. A comparative study of curve fitting procedures using the kinetic thermodynamic model and those utilizing well-known adsorption isotherms was undertaken. Three types of isotherms were used, Langmuir, Frumkin and Flory-Huggins isotherm. The results show that the kinetic-thermodynamic model and Flory-Huggins isotherms are more suitable to fit the data for the four inhibitors, at all applied temperatures. From the values of binding constants, K, ...

2003-04-01

230

Analysis of myocardial time-activity curves of /sup 123/I-heptadecanoic acid. Pt. 1. Curve fitting  

Energy Technology Data Exchange (ETDEWEB)

Myocardial time-activity curves can be described by two or more parameters. To establish the optimal curve fitting method 33 myocardial time-activity curves were analyzed with different curve fitting methods: monoexponential, biexponential and monoexponential plus constant. A background correction was not applied. Biexponential curve fitting resulted in redundancy of parameters. Optimal curve fitting was obtained with monoexponential plus constant. The constant represents the background activity together with the stores radiolabelled lipids and the half-time value represents the wash-out of radioiodide from the myocardium. A strong relation was found between the constant and the half-time value: small errors in the determination of the constant (background activity) resulted in considerable errors of the half-time value. It is concluded that optimal analysis of ...

1987-12-01

231

Polynomial curve fitting method for refraction-angle extraction in diffraction enhanced imaging  

International Nuclear Information System (INIS)

X-ray diffraction enhanced imaging (DEI) is applied to inspect internal structures of weakly absorbing low-Z sample. How to extract phase information from raw images measured in different positions of rocking curve is the key problem of DEI. In this paper, we present an effective extraction method called polynomial curve fitting method, in order to extract accurate information angular in a fast speed. It is com- pared with the existing methods such as multiple-images statistical method and Gaussian curve fitting method. The experiments results on a plastic cylinder and a black ant at the Beijing Synchrotron Radiation Facility prove that the polynomial curve fitting method can obtain most approximate refraction-angle values and its computation speed is 10 times faster than the Gaussian curve fitting method. (authors)

2009-11-01

232

GHG emissions, GDP growth and the Kyoto Protocol: A revisit of Environmental Kuznets Curve hypothesis  

British Library Electronic Table of Contents (United Kingdom)

The Kyoto Protocol attempts through political negotiations to guide participating industrialized countries' greenhouse gas (GHG) emissions from a positive growing trend, to reach a peak point (or turning point), and then be reduced to a negative growth. That means the relationship between decreasing GHG emissions and economic growth may be described by an inverted-U curve (or called a bell-shaped curve), which is consistent with the concept of the Environmental Kuznets Curve (EKC) hypothesis.This research observed that the economic development and GHG emissions in Economies in Transition (EITs) exhibit a hockey-stick curve trend (or called quasi-L-shape curve), that also generates a lot of "hot air" which is significant to the implementation of the Kyoto Protocol. In addition, through the ...

2008-01-01

233

Rapamycin (sirolimus) protects against hypoxic damage in primary heart cultures via Na^+/Ca^2^+ exchanger activation  

British Library Electronic Table of Contents (United Kingdom)

Aims: Rapamycin (sirolimus) is an antibiotic that inhibits protein synthesis through mammalian targeting of rapamycin (mTOR) signaling, and is used as an immunosuppressant in the treatment of organ rejection in transplant recipients. Rapamycin confers preconditioning-like protection against ischemic-reperfusion injury in isolated mouse heart cultures. Our aim was to further define the role of rapamycin in intracellular Ca^2^+ homeostasis and to investigate the mechanism by which rapamycin protects cardiomyocytes from hypoxic damage. Main methods: We demonstrate here that rapamycin protects rat heart cultures from hypoxic-reoxygenation (H/R) damage, as revealed by assays of lactate dehydrogenase (LDH) and creatine kinase (CK) leakage to the medium, by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-d...

2011-01-01

234

National survey of the levels of persistent organochlorine pesticides in the breast milk of mothers in China  

British Library Electronic Table of Contents (United Kingdom)

The occurrence of persistent organochlorine pesticides (OCPs) in breast milk samples collected from mothers from twelve provinces in mainland China was investigated. Dichlorodiphenyltrichloroethanes (DDTs) were the most prevalent agent, followed by HCHs and HCB, whereas levels of chlordane compounds, drins and mirex were lower. The relatively lower DDE/DDT ratio in the Fujian rural area suggested more recent exposure to DDT than in other areas. The mean level of DDTs in breast milk from the southern China was higher than those from northern China (p < 0.05). A positive correlation was observed between concentration of DDTs in human milk and consumption of animal-origin food, suggesting that this parameter could play an important part in influencing OCPs burdens in lactating women. The mean...

2011-01-01

235

Metabolic and molecular stress responses of gilthead seam bream Sparus aurata during exposure to low ambient temperature: an analysis of mechanisms underlying the winter syndrome  

British Library Electronic Table of Contents (United Kingdom)

The winter syndrome in the gilthead sea bream Sparus aurata indicates that the species is exposed to critically low temperatures in Mediterranean aquaculture in winter. The present study of metabolic patterns and molecular stress responses during cold exposure was carried out to investigate this ?disease?, in light of the recent concept of oxygen and capacity limited thermal tolerance. The metabolic profile of fuel oxidation was examined by determining the activities of the enzymes hexokinase (HK), aldolase (Ald), pyruvate kinase (PK), l-lactate dehydrogenase (l-LDH), citrate synthase (CS), malate dehydrogenase (MDH) and 3-hydroxyacyl CoA dehydrogenase (HOAD) in heart, red and white muscle after exposure to temperatures of 10, 14 and 18?C. Especially, the increase in LDH activity combined ...

2010-01-01

236

Humectant. Hoshitsuzai  

Energy Technology Data Exchange (ETDEWEB)

This paper elucidates the effect of humectant performance on the wettability of the skin. Humectants are divided into the organic compounds, such as polyols, the organometallic compounds, such as sodium lactate and pyrolidone sodium carboxylate, and the water soluble high molecular compounds, such as polyethylene glycol and hyaluronic acid. Firstly, hygroscopic performances and characteristics of various hcmectants are illustrated. Then, the humectant performance of the skin and relation between amino acid in the horny layer and moisture content are described. The humectant performance possessed in the intercellular lipid of horny layer is also described. Furthermore, are explained the wettability of the skin by cosmetics and the role of humectant as an emulsifying assistant. A mechanism of the dry skin, improvement effect of the skin by humectants, and combining effect of the humectants are presented. Are also presented the nonaqueous emulsification, amino acid ...

1993-06-20

237

Effects of swimming training at the intensity equivalent to aerobic/anaerobic metabolic transition in alloxan diabetic rats  

British Library Electronic Table of Contents (United Kingdom)

The present study was designed to determine the exercise intensity equivalent to the metabolic aerobic/anaerobic transition of alloxan diabetic rats, through lactate minimum test (LMT), and to evaluate the effects of swimming exercise at this intensity (LM) on the glucose and protein metabolism of these animals. Adult male Wistar rats received alloxan (SD, alloxan-injected rats that remained sedentary) intravenously (30 mg kg?1 body weight) for diabetes induction. As controls (SC, vehicle-injected rats that remained sedentary), vehicle-injected rats were utilized. Two weeks later, the animals were submitted to oral glucose tolerance test (oGTT) and LMT. After the tests, some of the animals were submitted to swimming exercise training [TC (vehicle-injected rats that performed a 6-week exerc...

2007-01-01

238

ENSO affects sex ratio progeny in captive Iberian red deer despite a steady feeding regime  

British Library Electronic Table of Contents (United Kingdom)

Climate variability greatly affects animals through direct and indirect effects. Animals with slow reproductive adaptation to ecological changes such as large mammals are likely to have evolved mechanisms to anticipate early such impacts of climate variability on the environment. One of the adaptive mechanisms between reproductive costs and benefits in mammals affects parental investment through biases in sex ratio. Deer might be likely to show an early detection of climate variability because conception takes place in early autumn, but the main raising cost in deer concerns lactation, which takes place at the end of the following spring. The aim of this paper is to assess whether there is a relationship between global indices of climate variability such as El Ni?o-Southern Oscillation (EN...

2011-01-01

239

Cell culture and gene transcription effects of copper sulfate on Chinese hamster ovary cells  

British Library Electronic Table of Contents (United Kingdom)

Abstract This study reports the effects of varying concentrations of copper sulfate on the metabolic and gene transcriptional profile of a recombinant Chinese hamster ovary (CHO) cell line producing an immunoglobulin G (IgG)-fusion protein (B0). Addition of 50 M copper sulfate significantly decreased lactate accumulation in the cultures while increasing viable cell density and protein titer. These changes could be seen from day 6 and became increasingly evident with culture duration. Reducing the copper sulfate concentration to 5 M retained all the above beneficial effects, but with the added benefit of reduced levels of the aggregated form of the B0 protein. To profile the cellular changes due to copper sulfate addition at the transcriptional level, Affymetrix CHO microarrays were used to...

2011-01-01

240

Biochemical alterations induced by Zn and Cd individually or in combination in the serum of Oreochromis niloticus  

British Library Electronic Table of Contents (United Kingdom)

Measurement of serum biochemical parameters in response to metal exposures can be especially useful to help identify target organs of toxicity as well as the general health status of animals. Oreochromis niloticus were exposed to 5.0?mg/L?Zn, 1.0?mg/L?Cd, and 5.0?mg/L?Zn?+?1.0?mg/L?Cd mixture for 7 and 28?days, and alterations in serum enzyme activities and ion levels were measured. Significant changes in all the biochemical parameters were found to be time dependent. Following metal exposure, alkaline phosphatase activity was elevated at both exposure periods. No changes in activities of lactate dehydrogenase and lipase were observed in response to single or combined Zn and Cd exposure at 7?days while they increased at 28?days. Fish exposed to metals showed a decrease in cholinesterase ac...

2010-01-01

241

A Bayesian approach to analyze energy balance data from lactating dairy cows  

British Library Electronic Table of Contents (United Kingdom)

The objective of the present investigation was to develop a Bayesian framework for updating and integrating covariate information into key parameters of metabolizable energy (ME) systems for dairy cows. The study addressed specifically the effects of genetic improvements and feed quality on key parameters in current ME systems. These are net and metabolizable energy for maintenance (NEM and MEM, respectively), efficiency of utilization of ME for milk production (kL) and growth (kG), and efficiency of utilization of body stores for milk production (kT). Data were collated from 38 studies, yielding 701 individual cow observations on milk energy, ME intake, and tissue gain and loss. A function based on a linear relationship between milk energy and ME intake and correcting for tissue energy lo...

2011-01-01

242

Use of sting-response techniques for simulate diagnostics in human esophagus; Uso de tecnicas estimulo-respuesta para simular diagnosticos en esofago humano  

Energy Technology Data Exchange (ETDEWEB)

In this work a study of simulation of the gamma graphic studies that are carried out in human esophagus in the Dept. of Nuclear Medicine of the 'Celestino Hernandez Robau Hospital of Santa Clara is presented. For the investigation tubular reactors were used and sting-response techniques with radioactive tracer of Technetium 99 metastable to a concentration of 1 mCi and several flows were applied. The distribution curves of residences times were obtained, those that respond to an equation of the type: Y = A + B exp (- exp((x-C)/D)) - ((x-C/D)+1). They were also carried out, optimizations studies of the doses of the radioactive to give to the patients from 1 mCi (that is the one used in studies) up to 0,5 mCi, and the influences on the obtained distributions of residence time were analyzed. It was confirmed the possibility to lower the doses with clear information of the signal. It was also carried out a simulation of the attenuation of the radiations that ...

2003-07-01

243

Thermoluminescence emission of X-irradiated Eu{sup 2+} doped KBr single crystals  

Energy Technology Data Exchange (ETDEWEB)

In this paper we discuss the results of thermoluminescence (TL) studies carried out on freshly quenched crystals of KBr doped with {approx} 50 ppm of Eu{sup 2+} ions which were X-irradiated at room temperature. The TL glow curve of this phosphor material consists of three glow peaks at 355, 376 and 398 K whose intensities increased as a function of X-irradiation time. The TL glow peaks were analyzed by the total curve-fitting method in order to obtain the characteristic parameters; activation energy, pre-exponential factor and kinetic order. The spectral character of the emission recorded during thermoluminescence was found to be the same for all glow peaks and consists of a broad band centered at {approx} 420 nm. It is proposed that the model of the TL process most consistent with our experimental results is one in which the Eu{sup 2+} impurity acts as an electron trap during the irradiation process and that the radiation ...

1996-12-31

244

Thermoluminescence emission of X-irradiated Eu"2"+ doped KBr single crystals  

International Nuclear Information System (INIS)

In this paper we discuss the results of thermoluminescence (TL) studies carried out on freshly quenched crystals of KBr doped with #approx# 50 ppm of Eu"2"+ ions which were X-irradiated at room temperature. The TL glow curve of this phosphor material consists of three glow peaks at 355, 376 and 398 K whose intensities increased as a function of X-irradiation time. The TL glow peaks were analyzed by the total curve-fitting method in order to obtain the characteristic parameters; activation energy, pre-exponential factor and kinetic order. The spectral character of the emission recorded during thermoluminescence was found to be the same for all glow peaks and consists of a broad band centered at #approx# 420 nm. It is proposed that the model of the TL process most consistent with our experimental results is one in which the Eu"2"+ impurity acts as an electron trap during the irradiation process and that the radiation induced ...

245

Kinetic study of formic acid oxidation on Ti/IrO_2 electrodes prepared using the spin coating deposition technique  

International Nuclear Information System (INIS)

In the first part of this paper, IrO_2 electrodes produced by thermal decomposition of H_2IrCl_6 precursor were manufactured using the spin coating deposition technique, where centrifugal forces spread the precursor solution with simultaneous evaporation of the solvent on the rotating Ti substrate. It was found using this technique, that it is possible to obtain thin and uniform IrO_2 coatings with controlled loadings. The influence of the concentration of iridium salt in the precursor solution (c_0) as well as the influence of the rotation speed at which the substrate spins (#omega#) on the IrO_2 loading have been studied using voltammetric charge measurements. From these results, a simple relation has been proposed for the estimation of the IrO_2 loading for a given c_0 and #omega#. In the second part of this paper and from measurements performed using different IrO_2 loadings and formic acid concentrations, the kinetic parameters of the oxidation of formic acid have been ...

2010-09-30

246

Effect of earthquakes on ambient noise cross-correlation function  

Science.gov (United States)

Surface wave tomography method based on analysis of ambient noise is widely used during the last decade. It is assumed that correlated component of noise is composed of surface waves generated by sources distributed over the Earth's surface more or less uniformly. In such a case the cross-correlation function (CCF) at two stations may be considered as the Green's function of surface wave. This function should be symmetric relatively to zero time. However analysis of CCF at the stations located at the East-European Platform shows that as a rule CCF is characterized with a strong asymmetry. Since "purered noise cannot be extracted from seismic records due to superposition of earthquake signals, the method for calculation of CCF includes amplitude normalization for suppression of earthquakes that reduces signals from earthquakes to a noise level. The parts of records containing waves from earthquakes are neglected because of their short duration. Present study shows that this contribution ...

2011-09-01

247

The Charles University in Prague Environment Centre - Environmental Kuznets curve  

Wastenet

... The main goal was the analysis of the Environmental Kuznets Curve hypothesis for the Czech Republic. A paper by Bruha and Scasny, accepted to the European Society of Ecological Economics, ( Lisbon June 2005), analyses driving forces (including economic policy) on ...

248

Some problems about the spline curve fitting method  

International Nuclear Information System (INIS)

The parameters including knot numbers, knot positions and the weights associated with the systematic errors in the cubic spline curve fitting method were discussed. The conditions of using fitting criterion were given as well.

249

Bragg curves of fission fragments in gases  

Energy Technology Data Exchange (ETDEWEB)

An unexpectedly high probability of collisions between the fission particles and the atoms in an ionization chamber along the entire particle track causes a strong fluctuation of the shapes of the Bragg curves. This fluctuation imposes an upper limit of the charge resolution ..delta..Z/Z which can be achieved.

1986-03-01

250

A boosting method for maximizing the partial area under the ROC curve  

UK PubMed Central (United Kingdom)

BackgroundThe receiver operating characteristic (ROC) curve is a fundamental tool to assess the discriminant performance for not only a single marker but also a score function combining...Full Text Available

251

THE EFFECT OF THE ICE-SEPARATION CURVE ON THE ...  

Science.gov (United States)

... However, the solution of the Stefan problem in this context becomes abruptly complicated, since within each zone, the differential equations ...

252

Spreadsheet determines hyperbolic-decline parameters  

Energy Technology Data Exchange (ETDEWEB)

Production decline-curve analysis is accepted for prediction of future performance of oil and gas wells and fields. One type of decline-curve analysis involves the hyperbolic-decline-curve equation. The challenge with this equation is to determine simultaneously three parameters. The new method creates a computer spreadsheet containing a set of production data. Then, the specific arrangement of cells and columns containing data and/or formulas allows for statistical fits of the data. Finally, setting-up the nonlinear solver allows for optimization of the three parameters by maximization of the square of the regression coefficient. Eight field cases demonstrated the repeatable and rapid curve-fitting of the method.

1994-03-14

253

Simulation of relative permeability hystersis to the nonwetting phase  

Energy Technology Data Exchange (ETDEWEB)

In reservoir fluid flow, the situation described by an increase in nonwetting phase saturation followed by an increase in wetting phase saturation causes a relative permeability hysteresis effect that is well known. This paper presents a method which allows the calculation of imbibition relative permeability starting at any saturation. The data required are the drainage curve, the historical maximum non wetting saturation, and a minimum of one additional point on some corresponding experimental imbibition curve. In this development, all imbibition curves are shown to be parallel. Also significant is the fact that the residual nonwetting phase saturation can be calculated without a complete experimental specification of the imbibition curve. 5 refs.

1981-01-01

254

New method for determining the energy gap of a superconductor using the maximum in differential conductance of electron tunneling spectrum  

Energy Technology Data Exchange (ETDEWEB)

A new method for determining the energy gap of a superconductor using the maximum in the differential conductance curve of electron tunneling spectrum is given in this paper. The V/sub max//kT versus ..delta../kT curve was calculated from tunneling theory. V/sub max/, the voltage of the conductance maximum, can be measured from electron tunneling spectrum. ..delta../kT can be found from this curve, then the energy gap ..delta.. can be calculated. This method is simple, fast and accurate. The accuracy almost approaches that of the curve fitting method.

1986-02-01

255

Influence of HNS on the Microstructure and Properties of Cast ...  

Science.gov (United States)

... The ultimate compressive strength was measured, and values for Young's modulus were calculated from the linear portion of the test curve. ...

1981-04-01

256

Fatigue lifetime and endurance limit prediction for high-strength steels; Vorhersage der Lebensdauer und Dauerfestigkeit von hochfesten, durchhaertenden Staehlen  

Energy Technology Data Exchange (ETDEWEB)

Smooth and notched specimens of the bearing steel 100Cr6 (SAE 52100) in a bainitic condition were used to determine the S-N curves under tensile, torsional and combined in- and out-of-phase loading. In the area of high-cycle fatigue, crack initiation was most likely caused by inclusions like Titanium Carbonnitrides or Aluminium Oxides. A micro mechanical model for the crack initiation by inclusions was developed. Another model was developed to describe the influence of these inclusions on the lifetime. A weakest-link model, using the statistical distribution of inclusions and surface flaws, was used to describe the endurance limit. (orig.) [German] Es wurden Woehlerlinien unter Zug-Druck-, Torsions- sowie kombinierter phasengleicher und phasenverschobener Zug-Druck- und Torsionsbelastung fuer glatte und gekerbte Proben des Stahls 100Cr6 (SAE 52100) im bainitischen Zustand erstellt. Im Bereich der ...

2002-05-01

257

Assessment of predictive models for the failure of titanium and ferrous alloys due to hydrogen effects. Report for the period of June 16 to September 15, 1981  

Energy Technology Data Exchange (ETDEWEB)

The 1977 version of the Simpson-Puls-Dutton model appears to be the most amenable with respect to utilizing known or readily estimated quantities. The Pardee-Paton model requires extensive calculations involving estimated quantities. Recent observations by Koike and Suzuki on vanadium support the general assumption that crack growth in hydride forming metals is determined by the rate of hydride formation, and their hydrogen atmosphere-displacive transformation model is of potential interest in explaining hydrogen embrittlement in ferrous alloys as well as hydride formers. The discontinuous nature of cracking due to hydrogen embrittlement appears to depend very strongly on localized stress intensities, thereby pointing to the role of microstructure in influencing crack initiation, fracture mode and crack path. The initiation of hydrogen induced failures over relatively short periods of time can be characterized with fair ...

1982-04-01

258

Determination of efficiency curves of germanium detectors using natural radioactive materials  

International Nuclear Information System (INIS)

Efficiency calibration curves for different densities and geometries are necessary for activity determination of various environmental samples. Commercially available standards or natural radioactive materials are used for calibration. Potassium compounds are especially suitable, since they can be mixed with unknown samples. It is possible to determine efficiency curve and unknown activity of sample knowing "4"0 K activity. (author).

259

Bragg curve spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

A new method named 'Bragg curve spectroscopy', based on the Bragg curve of the heavy ion being stopped in a gaseous ionization chamber, has been developed for identifying the particle and measuring its energy. The design of such a chamber and the experience obtained with chamber using various kinds of fast heavy ions are described. In conclusion, several problems to be solved in this method are pointed out.

1982-05-01

260

Bragg curve spectroscopy  

International Nuclear Information System (INIS)

A new method named 'Bragg curve spectroscopy', based on the Bragg curve of the heavy ion being stopped in a gaseous ionization chamber, has been developed for identifying the particle and measuring its energy. The design of such a chamber and the experience obtained with chamber using various kinds of fast heavy ions are described. In conclusion, several problems to be solved in this method are pointed out. (orig.).

261

Atomic interactions between plutonium and helium.  

Energy Technology Data Exchange (ETDEWEB)

An essential issue in gallium (Ga)-stabilized fcc-phase plutonium ({delta}-Pu) is the formation of helium (He) voids and bubbles emanating from the radiolytic decay of the Pu. The rate of formation of He voids and bubbles is related to the He-defect formation energies and their associated migration barriers. The size and shape distributions of the bubbles are coupled to these critical migration processes. The values of the defect formation energies, internal pressure, and migration barriers can be estimated from atomistic calculations. Complicating this picture is the destruction of He-filled voids and bubbles by subsequent radiolytic decay events. The present study concerns the construction of the necessary potential energy surfaces for the Pu-He and He-He interactions within the modified embedded atom method (MEAM). Once fully tested, the potentials will be used to estimate the He-defect formation energies and barriers to the migration of these defects for both interstitial and ...

2002-01-01

262

Valuing climate protection through willingness to pay for biomass ethanol  

Energy Technology Data Exchange (ETDEWEB)

This study uses a multi-part, split-sample contingent valuation method (CVM) and fair share (FS) survey to better understand the public's valuation of mitigating global climate change through its willingness to pay for biomass or 'cellulosic' ethanol. In addition to a basic CVM question, a related scenario was developed that asked half of the survey respondents to state their fair share cost to lessen a potential food shortage in the next decade, also through the expanded use of cellulosic ethanol. Three alternative biomass feedstocks were assessed: farming residues, forestry residues and paper mill wastes, and municipal solid wastes. Overall a slightly larger proportion of respondents were WTP extra for cellulosic ethanol in the basic CVM scenario than in the FS scenario, though no significant differences were found in the WTP for the different feedstocks. Bid curve lognormal regression results for the two models ...

2009-05-15

263

The design and performance of a capacitance sensor for two-phase flow concentration measurements in a square duct  

Energy Technology Data Exchange (ETDEWEB)

The use of capacitance sensors for measuring phase concentrations in two-phase flow has gained popularity in recent years. In designing such sensors, there are many issues which must be considered in order to optimize performance: two-phase flow regime, permittivity of the phases, duct geometry, electrical shielding, desired spacial resolution of film thickness, and temperature variation in the flow field. These design issues are discussed and are used to optimize the design of a capacitance sensor which is used to measure vapor volume fraction in annular, two-phase vertical upflow and downflow in a square duct. The sensor was tested and implemented in a 12.7 mm square duct mounted in a flow boiling facility containing FC-72, a low permittivity dielectric fluid ({epsilon}{sub r} = 1.75). Using analytical modeling, an adjustable-length, parallel-plate design was developed and refined to achieve good sensitivity to flow conditions. The sensor output was calibrated ...

1995-12-31

264

Swift panchromatic observations of the bright gamma-ray burst GRB050525a  

CERN Document Server

The bright gamma-ray burst GRB050525a has been detected with the Swift observatory, providing unique multiwavelength coverage from the very earliest phases of the burst. The X-ray and optical/UV afterglow decay light curves both exhibit a steeper slope ~0.15 days after the burst, indicative of a jet break. The timing of the jet break combined with the total gamma-ray energy of the burst constrains the opening angle of the jet to be 2.5 degrees. We derive an empirical `time-lag' redshift from the BAT data of z_hat = 0.69 +/- 0.02, in good agreement with the spectroscopic redshift of 0.61. Prior to the jet break, the X-ray data can be modelled by a simple power law with index alpha = -1.2. However after 300s the X-ray flux brightens by about 30% compared to the power-law fit. The optical/UV data have a more complex decay, with evidence of a rapidly falling reverse shock component that dominates in the first minute or so, giving way to a flatter ...

2006-01-01

265

Suzaku and Optical Spectroscopic Observations of SS 433 in the 2006 April Multiwavelength Campaign  

CERN Document Server

We report results of the 2006 April multi-wavelengths campaign of SS 433, focusing on X-ray data observed with Suzaku at two orbital phases (in- and out-of- eclipse) and simultaneous optical spectroscopic observations. By analyzing the Fe25 K_alpha lines originating from the jets, we detect rapid variability of the Doppler shifts, dz/dt ~ 0.019/0.33 day^-1, which is larger than those expected from the precession and/or nodding motion. This phenomenon probably corresponding to "jitter" motions observed for the first time in X-rays, for which significant variability both in the jet angle and intrinsic speed is required. From the time lag of optical Doppler curves from those of X-rays, we estimate the distance of the optical jets from the base to be ~(3-4) \\times 10^14 cm. Based on the radiatively cooling jet model, we determine the innermost temperature of the jets to be T_0 = 13 +/- 2 keV and 16 +/- 3 keV (the average of the blue and red jets) ...

2010-01-01

266

Radiometric measurement of temperature distributions in solar cavity receivers  

Energy Technology Data Exchange (ETDEWEB)

An engineering tool incorporating a scanning infrared radiometer, an image digitizer, a microcomputer, and the software to drive the system was developed to allow remote mapping of the temperature distribution in solar cavity receivers. Using enclosure analysis, the infrared image processing program extracts the irradiance map from the radiosity map of the cavity to yield an emissive power map. Using the calibration curve of the radiometer and the emissivity of the surface of the cavity, the emissive power map is transformed into a temperature map. The system was tested by comparing its calculated temperatures to temperatures measured by thermocouples at several locations on the surfaces of heated model cavity receivers. The average relative error for the cavities ranged from 4.6%--34.9%, with the relative error on the base usually less than half that on the wall. Some work was also carried out to compensate the detected radiosity field for the ...

1989-03-01

267

Multidimensional two-phase flow regime distribution in a PWR downcomer during an LBLOCA refill phase  

Energy Technology Data Exchange (ETDEWEB)

The multidimensional countercurrent two-phase flow regimes that occur in a pressurized-water reactor (PWR) vessel downcomer during the refill phase of a large-break loss-of-coolant accident are studied using a transparent 1/10 scale model of a PWR vessel. The various flow regimes and their distribution in the downcomer have been identified and mapped for a range of air-water flooding experiments. The two-phase flow patterns that are identified in the downcomer included various types of film flows, droplet flows, countercurrent churn flows and cocurrent flows depending on the flooding condition. Through observation of the two-phase flow dynamics it was deduced that the physical mechanisms associated with the flooding processes could be separated into a liquid entrainment process and a film flow reversal process. In addition to the above exercise, the effect of non-uniform injection of water into the downcomer via different combinations of cold leg was studied ...

1994-09-01

268

Multidimensional two-phase flow regime distribution in a PWR downcomer during an LBLOCA refill phase  

International Nuclear Information System (INIS)

The multidimensional countercurrent two-phase flow regimes that occur in a pressurized-water reactor (PWR) vessel downcomer during the refill phase of a large-break loss-of-coolant accident are studied using a transparent 1/10 scale model of a PWR vessel. The various flow regimes and their distribution in the downcomer have been identified and mapped for a range of air-water flooding experiments. The two-phase flow patterns that are identified in the downcomer included various types of film flows, droplet flows, countercurrent churn flows and cocurrent flows depending on the flooding condition. Through observation of the two-phase flow dynamics it was deduced that the physical mechanisms associated with the flooding processes could be separated into a liquid entrainment process and a film flow reversal process. In addition to the above exercise, the effect of non-uniform injection of water into the downcomer via different combinations of cold leg was studied ...

1993-10-01

269

Medical image transmission via communication satellite. Evaluation of bone scintigraphy  

International Nuclear Information System (INIS)

As compared with terrestrial circuits, the communication satellite possesses superior characteristics such as wide area coverage, broadcasting, high capacity, and robustness to disasters. Utilizing the narrow band channel (64 kbps) of the geostationary satellite JCSAT 1 located at the altitude of 36,000 km above the equator, the authors investigated satellite-relayed medical imagings by video signals, with bone scintigraphy as a model. Each bone scintigraphy was taken by a handy-video camera, digitalized and transmitted from faculty of technology located at 25 kilometers apart from our department. Clear bone scintigraphy was obtained via satellite, as seen on the view box. Eight nuclear physicians evaluated 20 cases of bone scintigraphy. ROC (Receiver Operating Characteristic) analysis was performed between the scintigraphies on view box and via satellite by the rating method. The area under the ROC curve was 91.6#+-#2.6% via satellite, and ...

270

Isotope exchange reaction between tritiated water and hydrogen on SiC  

Energy Technology Data Exchange (ETDEWEB)

SiC has been considered as a primary candidate material for a first wall component in future fusion reactor because it has been claimed that SiC has excellent high-temperature properties, good chemical stability and low activation. However, the behavior of tritium on SiC has not been discussed yet. In this study, tritium trapping capacity on the surface of SiC was experimentally obtained at the temperature range of 25-800 deg. C in consideration of tritium trapping to the experimental system. The capacity, which was independent of the water vapor pressure in the gas phase and the temperature, was determined as about 10{sup 6} Bq/cm{sup 2}. The isotope exchange reaction rate between tritiated water in a gas phase and hydrogen on the surface was quantified at the temperature of 25, 500 and 700 deg. C in consideration of the behavior of tritium trapping at change of experimental condition by the numerical curve fitting method applying the serial reactor ...

2003-11-15

271

Isotope exchange reaction between tritiated water and hydrogen on SiC  

International Nuclear Information System (INIS)

SiC has been considered as a primary candidate material for a first wall component in future fusion reactor because it has been claimed that SiC has excellent high-temperature properties, good chemical stability and low activation. However, the behavior of tritium on SiC has not been discussed yet. In this study, tritium trapping capacity on the surface of SiC was experimentally obtained at the temperature range of 25-800 deg. C in consideration of tritium trapping to the experimental system. The capacity, which was independent of the water vapor pressure in the gas phase and the temperature, was determined as about 10"6 Bq/cm"2. The isotope exchange reaction rate between tritiated water in a gas phase and hydrogen on the surface was quantified at the temperature of 25, 500 and 700 deg. C in consideration of the behavior of tritium trapping at change of experimental condition by the numerical curve fitting method applying the serial reactor ...

2003-11-15

272

Interactions among transportation fuel substitution, vehicle quality growth, and national economic growth  

Energy Technology Data Exchange (ETDEWEB)

Estimates of annual rates of change of fuel switching are constructed using logistic curve models fitted to often sparse historical data on fuel use in the USA. The estimated annual rate of loss of market share of an old fuel is then shown to be correlated with five-year averages of declines in the rate of growth of affected vehicle numbers. Other statistical tests show a positive correlation between five-year average changes in the rate of growth of the vehicle numbers and of macroeconomic activity when the affected vehicles are directly responsible for a large share of that activity. The vehicle types shown to have this effect are locomotives from 1885-1915 and automobiles thereafter. The third set of tests supports an interpretation that the indirect effects of fuel switches are significant and consistent with GNP throughout the 1880-1980 period. It is shown that a pronounced drop in GNP growth occurs at the time when the important fuel ...

1989-05-01

273

Influence of the menstrual cycle and of menopause on the gastric emptying rate of solids in female volunteers  

Energy Technology Data Exchange (ETDEWEB)

The aim of this study was to assess the influence of the normal menstrual cycle and of menopause on the gastric emptying rate of solids. Gastric emptying was studied in 15 premenopausal and ten postmenopausal women with an isotopic technique after the ingestion of a radiolabelled test meal. Premenopausal women were studied twice: Within 1 week prior to menses and again 1 week after onset of menses. Postmenopausal women were studied only once. The emptying curves of the solid component of the meal fitted a linear model. The half-emptying time was 78[+-]5 min during the follicular phase, 75[+-]7 min during the luteal phase and 76[+-]6 min in postmenopausal women (differences not statistically significant). The mean percentages of the meal retained in the stomach at different time intervals were also similar in the three groups. These results suggest that the menstrual cycle does not influence the gastric emptying rate of solids, which remains ...

1993-07-01

274

Influence of the menstrual cycle and of menopause on the gastric emptying rate of solids in female volunteers  

International Nuclear Information System (INIS)

The aim of this study was to assess the influence of the normal menstrual cycle and of menopause on the gastric emptying rate of solids. Gastric emptying was studied in 15 premenopausal and ten postmenopausal women with an isotopic technique after the ingestion of a radiolabelled test meal. Premenopausal women were studied twice: Within 1 week prior to menses and again 1 week after onset of menses. Postmenopausal women were studied only once. The emptying curves of the solid component of the meal fitted a linear model. The half-emptying time was 78#+-#5 min during the follicular phase, 75#+-#7 min during the luteal phase and 76#+-#6 min in postmenopausal women (differences not statistically significant). The mean percentages of the meal retained in the stomach at different time intervals were also similar in the three groups. These results suggest that the menstrual cycle does not influence the gastric emptying rate of solids, which remains ...

275

High temperature susceptibilities of actinide monopnictides and monochalcogenides  

International Nuclear Information System (INIS)

The inverse susceptibilities of the monopnictides and monochalcogenides of the light rare earths plotted vs. temperature flatten off at high temperatures. This behaviour is well explained by van Vleck paramagnetism of the excited states of the multiplet. For almost all actinide pnictides and chalcogenides a similar flattening-off is observed. Since spin orbit coupling is much stronger than in the light rare earth compounds an analogous interpretation is not possible. Susceptibility curves for uranium compounds can be fitted by adding a temperature dependent enhanced Pauli paramagnetism to the Curie-Weiss term (modified Curie-Weiss law). The high temperature susceptibility behaviour of neptunium compounds is very similar to uranium compounds i.e. an appreciable deviation from the Curie-Weiss law is only visible for the chalcogenides. The plutonium chalcogenides show a temperature independent paramagnetism, which can be explained either by a ...

1998-06-12

276

Fuzzy decision making in multiobjective long-term scheduling of hydrothermal system  

Energy Technology Data Exchange (ETDEWEB)

In the paper, a fuzzy decision-making methodology is presented to decide the generation schedule of long-term hydrothermal problems with explicit recognition of statistical uncertainties in system production cost data, NO{sub x} emission data, system load demand and hydro reservoir water inflows. In deciding the optimal operation, three objectives operating cost, NO{sub x} emission and unsatisfied load demand over the whole of the planning period are simultaneously minimised. Specific technique is put forth to convert the stochastic models into their deterministic equivalents. The weighted minimax method is used to simulate the tradeoff relation between the conflicting objectives in the non-inferior domain. The fuzzy set theory is exploited to choose the best operating point over the tradeoff curve. An efficient decomposition technique is applied to reduce the complexity of the problem. In each subproblem, thermal generations are obtained by ...

2001-01-01

277

Enhanced corrosion resistance of mild steel in hydrochloric acid solution by new thiadiazole derivatives: Electrochemical, theoretical and XPS studies  

Energy Technology Data Exchange (ETDEWEB)

In this work, a new class of thiadiazole derivatives, namely 3,5-bis(2-thienyl)-1,3,4-thiadiazole (2-TTH) and 3,5-bis(3-thienyl)-1,3,4-thiadiazole (3-TTH), have been studied as possible corrosion inhibitors for mild steel in molar hydrochloric acid (1M HCl). Polarisation curves and AC impedance methods have been used. These studies have shown that the thiadiazole derivatives were very good inhibitors for mild steel in 1M HCl. Comparison of results showed that 3-TTH was the best inhibitor. The potential of zero charge (PZC) of mild steel was studied by ac impedance method, and the mechanism of adsorption has been predicted. X-ray photoelectron spectroscopy surface analysis with thiadiazole derivatives shows that it chemisorbed at the mild steel/HCl interface. The adsorption of these inhibitors followed Langmuir's adsorption isotherm. The electronic properties of 2-TTH and 3-TTH, obtained using the AM1 semi-empirical quantum chemical approach, were ...

2004-07-01

278

Effect of velocity variation on secondary-ion-emission probability: Quantum stationary approach  

Energy Technology Data Exchange (ETDEWEB)

The ion-velocity dependence of the ionization probability for an atom ejected from a surface is examined by using a quantum approach in which the coupled motion between electrons and the outgoing nucleus is followed along the whole trajectory by solving the stationary Schroedinger equation. We choose a very-small-cluster-model system in which the motion of the atom is restricted to one dimension, and with energy potential curves corresponding to the involved channels varying appreciably with the atom position. We found an exponential dependence on the inverse of the asymptotic ion velocity for high emission energies, and a smoother behavior with slight oscillations at low energies. These results are compared with those obtained within a dynamical-trajectory approximation using either a constant velocity equal to the asymptotic ionic value, or expressions for the velocity derived from the eikonal approximation and from the classical limit of the ...

1989-11-01

279

Detailed comparison of the structures and kinematics of simulated and observed barred galaxies  

CERN Document Server

We examine the observable properties of simulated barred galaxies including radial mass profiles, edge-on structure and kinematics, bar lengths and pattern speed evolution for detailed comparison to real systems. We have run several simulations in which bars are created through inherent instabilities in self-consistent simulations of a realistic disc+halo galaxy model with a disc-dominated, flat rotation curve. These simulations were run at high (N=20M particles) and low (N=500K) resolution to test numerical convergence. We determine the pattern speeds in simulations directly from the phase angle of the bar versus time and the Tremaine-Weinberg method. Fundamental dynamics do not change between the high and low resolution, suggesting that convergence has been reached in this case. We find the higher resolution is needed to simulate structural and kinematic properties accurately. The edge-on view of the higher-resolution system clearly shows the ...

2003-01-01

280

Crystallization fouling of calcium sulfate dihydrate on heat-transfer surfaces  

Energy Technology Data Exchange (ETDEWEB)

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

1996-02-01

281

Characteristics of volatile fatty acid decomposition in anaerobic fluidized bed  

Energy Technology Data Exchange (ETDEWEB)

The growth kinetics constants and concentration of active attached biomass in an anaerobic fluidized bed which decomposes acetic, propionic and butyric acid were estimated. The mixture of above mentioned fatty acids was supplied to the fluidized bed in the range of hydraulic retention time (HRT) from 0.25 to 2 days. After the effluent reached in a steady state in quality, batch experiments were conducted separately with each fatty acid as a substrate in order to investigate the decomposition characteristics of each substrate by attached biomass. In order to estimate the parameter values of the growth kinetics of the bacteria, batch experiments were also conducted under the completely mixed condition using detached biomass from a support material. The changes of fatty acid concentrations with time were clearly expressed with the Monod growth model. Maximum specific substrate decomposition rates and saturation constants, and active biomass concentrations were ...

1988-06-01

282

CRC customer versus rater octane number requirement program (1990)  

Energy Technology Data Exchange (ETDEWEB)

A CRC cooperative program was conducted to determine the difference in octane requirements between technical raters and 'customers' (the general driving public). The tests were conducted in two phases, with the second being a repeat of the first to verify the results obtained. The trained raters used the CRC E-15 procedure to determine the octane requirement of the vehicles while the customers' perception and objection to knock were determined through the use of a questionnaire. The customers' responses (perception and objection level) were based upon audible knock, acceleration performance, and after-run on a series of full-boiling-range customer/rater unleaded (FBRCU) reference-fuels. Data were analyzed from 168 1988-1991 model-year vehicles, with 126 of these tested in Phase II. The results showed that the customers, objections and perceptions were overwhelmingly based on knock, rather than acceleration performance or ...

1993-10-01

283

Analytical study on analysis methods of several random variables for seismic nonlinear responses of reactor buildings  

International Nuclear Information System (INIS)

In the case wherein nonlinear seismic response analyses are carried out, the response values vary due to the variations in materials and modeling. In this paper, nonlinear analyses of several random variables are carried out using: i. a conventional method; ii. a two-point estimation method (i. and ii. are simplified methods); and iii. Monte Carlo simulation (detailed method) to examine the variability of the response in the excessive nonlinear range for seismic responses of shear walls. The analyses are performed to a PWR-3 loop type reactor building which is one of the most typical reactor buildings in Japan. The variations are considered in specified compressive strength of concrete, concrete damping factor, shear wave velocity of soil and shapes of shear stress-strain relation curves of shear walls. As the results by the two simplified methods closely matched the Monte Carlo simulation results, the appropriateness for applying the ...

1993-08-15

284

A Numerical Algorithm for Determining the Contact Stress of Circular Crowned Roller Compressed between Two Flat Plates  

Science.gov (United States)

The main purpose of this paper is to explore a numerical algorithm for determining the contact stress when a circular crowned roller is compressed between two plates. To start with, the deformation curve on a plate surface will be derived by using the contact mechanical model. Then, the contact stress distribution along the roller which occurs on the plate surface is divided into three parts: from the center of contact to the edge, the edge and apart from the contact line. The first part is calculated by the elastic contact theorem for the contact subjected to nominal stress between non-crowned parts of roller and plates, the second part is obtained by the classical Hertzian contact solution for the contact between crowned parts of roller and plates, and the third part is simulated as exponential decay. In order to overcome the defect of the half space theorem, in which a plate with infinite thickness is assumed initially, a weighting method is ...

2007-01-01

285

Meadow voles, Microtus pennsylvanicus, have the capacity to recall the "what", "where", and "when" of a single past event.  

Science.gov (United States)

Some non-human animals may possess the ability to recall the "what", "where", and "when" of a single past event. We tested the hypothesis that male meadow voles possess the capacity to recall the "what", "where", and "when" of a single past event associated with mate selection in two experiments. Briefly, male voles were allowed to explore an apparatus that contained two chambers. One chamber contained a day-20 pregnant female (24 h prepartum). The other chamber contained a sexually mature female that was neither pregnant nor lactating (REF female). Twenty-four hour after the exposure, the males were placed in the same apparatus, which was empty and clean. At this time, the pregnant female would have entered postpartum estrus (PPE), a period of heightened sexual receptivity. Males initially chose and spent significantly more time investigating the chamber that originally housed the pregnant female (now a PPE female) than the chamber that originally housed the REF ...

2007-07-26

286

In vitro toxicity of silica nanoparticles in human lung cancer cells  

International Nuclear Information System (INIS)

The cytotoxicity of 15-nm and 46-nm silica nanoparticles was investigated by using crystalline silica (Min-U-Sil 5) as a positive control in cultured human bronchoalveolar carcinoma-derived cells. Exposure to 15-nm or 46-nm SiO_2 nanoparticles for 48 h at dosage levels between 10 and 100 #mu#g/ml decreased cell viability in a dose-dependent manner. Both SiO_2 nanoparticles were more cytotoxic than Min-U-Sil 5; however, the cytotoxicities of 15-nm and 46-nm silica nanoparticles were not significantly different. The 15-nm SiO_2 nanoparticles were used to determine time-dependent cytotoxicity and oxidative stress responses. Cell viability decreased significantly as a function of both nanoparticle dosage (10-100 #mu#g/ml) and exposure time (24 h, 48 h, and 72 h). Indicators of oxidative stress and cytotoxicity, including total reactive oxygen species (ROS), glutathione, malondialdehyde, and lactate dehydrogenase, were quantitatively assessed. Exposure to SiO_2 ...

2006-12-15

287

Characterization of decarburisation processes during austenitising of the rolling bearing steel 100Cr6. Part 2: Modelling of the carbon concentration profile by means of the finite element method; Charakterisierung von Randentkohlungsvorgaengen bei der Austenitisierung des Waelzlagerstahls 100Cr6. Teil 2: Modellierung des Kohlenstoff-Tiefenverlaufs mit Hilfe der Methode der Finiten Elemente  

Energy Technology Data Exchange (ETDEWEB)

The quantitative measurement of carbon concentration-distance curves serves as fundamental prerequisite for the evaluation of rim zone properties connected with decarburisation processes in material science. This was shown in part 1 of the present work with two samples from through-hardenable rolling bearing steel 100Cr6 (SAE 52100) austenitised in different oxidising atmospheres by position dependent determination of hardness, residual stresses, and X-ray line broadening ({l_brace}211{r_brace} {alpha}'-Fe diffraction line). In practice, it is important to predict carbon concentration-distance curves under prevailing heat treatment conditions or to conclude conversely from profile measurements. Based on a refined kinetics model of a diffusion-controlled process, part 2 therefore presents a simulation tool developed by means of the finite element method (FEM). Apart from the concentration dependence of the diffusion ...

2003-08-01

288

Random walk function in the analysis of time-activity curves from dynamic radionuclide studies  

Energy Technology Data Exchange (ETDEWEB)

The random walk function is a mathematical function derived from studies of the mass transport and flow of diffusible materials through tubes. Approximations to the function were first used some time ago in the field of cardiac tracer dilution curves, but in the absence of rapid and reproducible curve fitting the method never became commonplace. The current study uses the latest curve-fitting techniques and shows how the method may be used with precision in the analysis of time-activity curves from dynamic oesophageal and blood flow studies. The physiological basis of the method is given and parameters obtained which relate to both the rate of flow and the local dispersion of the bolus.

1987-04-01

289

Nonlinear response and stability of a spindle system supported by Ball bearings  

Energy Technology Data Exchange (ETDEWEB)

In this effort, the nonlinear responses and stability of a spindle system supported by ball bearings are presented. The dynamics of this system is described by a set of second order differential equations with a nonlinear piecewise smooth force. The Floquet theory is applied to investigate the stability of the periodic solution. Due to the loss of contact between the raceways and balls in the ball bearing, the bending of the frequency response curves switch to the left at the weak resonance region, which is similar to the frequency response curves of a system with a soft spring. With the decrease of the bearing clearance, the bending of the frequency response curves switch to the right, which is similar to the frequency response curves of a system with a hard spring. Increase of the frequency ratio, the bending of frequency response curves transforms from left to right. The route to ...

2010-09-15

290

Evaluation method for corrosion resistance of zirconium alloy  

International Nuclear Information System (INIS)

The present invention concerns a method of evaluating corrosion resistance of a zirconium alloy easily and in a short period of time. An anode polarization curve of the zirconium alloy is measured to obtain an anode polarization curve expressed by logarithm. The curve is converted to a potential-current density curve expressed by absolute values. The peak area in the curve of the converted potential-current density is indicated by numerical values. Further, the corrosion resistance of the zirconium alloy is evaluated based on the peak area converted into the numerical values as a reference. This method is based on the finding that the peak area has a close relation with nodular corrosion resistance, and the corrosion resistance can be judged with respect to a specific zircaloy-2. (T.M.).

1993-03-26

291

Bragg Curve Spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

An alternative utilization is presented for the gaseous ionization chamber in the detection of energetic heavy ions, which is called Bragg Curve Spectroscopy (BCS). Conceptually, BCS involves using the maximum data available from the Bragg curve of the stopping heavy ion (HI) for purposes of identifying the particle and measuring its energy. A detector has been designed that measures the Bragg curve with high precision. From the Bragg curve the range from the length of the track, the total energy from the integral of the specific ionization over the track, the dE/dx from the specific ionization at the beginning of the track, and the Bragg peak from the maximum of the specific ionization of the HI are determined. This last signal measures the atomic number, Z, of the HI unambiguously.

1981-05-01

292

Analysis of thermoluminescence glow curves of minerals sphene and epidote for radiation damage studies  

Energy Technology Data Exchange (ETDEWEB)

Thermoluminescence (TL) properties of sphene and epidote are of interest in studies related to their radiation damage. Natural and artificially induced TL of these minerals has, therefore, been investigated. Both minerals exhibit complex glow curves with several overlapping peaks. The Tsub(m) -Tsub(STOP) thermal cleaning procedure has revealed three peaks in the ..gamma.. ray induced glow curve of each mineral. That these peaks obey second order kinetics was indicated by the continuously slanting structure of the Tsub(m)-Tsub(STOP) curve. The TL parameters E and s have been calculated using (i) the initial rise method, and (ii) the glow-peak shape method. In general, the values of E calculated by the first method are found to be higher than those from the second. The TL curve-fitting method is also applied in order to calculate these parameters and to serve as a cross-check on the results.

1986-01-01

293

Surgical adjuvant therapy in colon carcinoma: a human tumor spheroid model for evaluating radiation sensitizing agents  

International Nuclear Information System (INIS)

HT-29 human colon tumor cells growing as spheroids have been evaluated as a model system for measuring the response of human colon tumor cell to antineoplastic agents. HT-29 cells have been capacity to form spheroids up to 1 mm or more in diameter when grown in spinner culture. The multicellular HT-29 spheroids develop hypoxic centers reflecting the cellular conditions found in human cancer treatment, i.e., nutritionally deficient hypoxic cells that are felt to be a significant source of both radiation and chemotherapy clinical treatment failures. Spheroids of increasing size were radiated and then dispersed into single cells for colony survival assay. Compared with irradiated single cell suspensions, the spheroid cells demonstrated a significant increase in radioresistance. Growing spheroids developed a complex radiation survival curve which was variable with respect to size of the spheroid. The drug 5-Fu was studied to examine in a ...

294

Safety of pipe whip restraints  

International Nuclear Information System (INIS)

Pipe whip restraints are used in nuclear power plants in order to limit the consequences of ruptured pipe whip effects and are thus an important part of the plant safety concept. The design of these devices is based on the choice of adequate construction and computational analysis supported by experimental investigation. Pipe whip restraints should, by means of deforming components, be able to absorb the energy of a ruptured pipe accelerated by the fluid reaction force. Since the elastic deformation of the restraint material is not sufficient for this purpose, or would result in excessive anchor loads, pipe whip restraints must generally be designed to work in the plastic range. Two types of restraints are presented in this paper, including the description of their mode of operation, design and computation. A comparison and critical evaluation of the calculation methods presently available are also given. The range of methods covers those developed for very simple ...

295

Experimental study on the air/water counter-current flow limitation in a model of the hot leg of a pressurized water reactor  

Energy Technology Data Exchange (ETDEWEB)

An experimental investigation on the air/water counter-current two-phase flow in a horizontal rectangular channel connected to an inclined riser has been conducted. This test-section representing a model of the hot leg of a pressurized water reactor is mounted between two separators in a pressurized experimental vessel. The cross-section and length of the horizontal part of the test-section are (0.25 m x 0.05 m) and 2.59 m, respectively, whereas the inclination angle of the riser is 50 deg. The flow was captured by a high-speed camera in the bended region of the hot leg, delivering a detailed view of the stratified interface as well as of dispersed structures like bubbles and droplets. Countercurrent flow limitation (CCFL), or the onset of flooding, was found by analyzing the water levels measured in the separators. The counter-current flow limitation is defined as the maximum air mass flow rate at which the discharged water mass flow rate is equal to the inlet ...

2008-12-15

296

Emergency ampacities of direct buried three phase underground cable systems  

Energy Technology Data Exchange (ETDEWEB)

A thermal model is formulated for the determination of the emergency transient ampacities of a three phase, horizontally spaced underground cable system. The model is based on a finite difference heat transfer analysis and the principle of superposition which permits the summation of the temperature rise of individual heat sources to eventually provide for the temperature rise of a multiple cable system. The thermal model is transformed into a complex computer program that is capable of calculating the real time cable temperature for any change in conductor current. The program is used to calculate the response of conductor temperatures caused by both ramp and step changes in currents for four conductor sizes between 4/0 and 1500 kcmil. The amount of time to reach conductor temperatures of 100/sup 0/C and 120/sup 0/C from a steady conductor temperature of 75/sup 0/C is calculated for the different conductor sizes and for ...

1983-07-01

297

A radiation hardening model of 9Cr-martensitic steels including Dpa and helium  

International Nuclear Information System (INIS)

Full text of publication follows: Low activation ferritic/martensitic steels are receiving a high priority in the European long term materials research. Although extensively investigated, the available experimental data do not cover all required parameter ranges and cannot unambiguously be used to produce hardening/embrittlement trend curves. Therefore, the main objective of this work is to provide a physically-based engineering model offering a rational to experimental observations. From the literature, experimental data were selected to establish a database that mainly consists of 8 to 9Cr-steels irradiated in the range of 50 to 600 deg. C up to 30 dpa and with a He-content up to 5000 appm. The database includes neutron and proton irradiations, He-implanted as well as B- and Ni-doped steels. Because of the difficulty of interpretation inherent to the Charpy impact test, only tensile data were considered. The difficulty stems from the large ...

2007-12-10

298

A model of episodic memory: mental time travel along encoded trajectories using grid cells.  

Science.gov (United States)

The definition of episodic memory includes the concept of mental time travel: the ability to re-experience a previously experienced trajectory through continuous dimensions of space and time, and to recall specific events or stimuli along this trajectory. Lesions of the hippocampus and entorhinal cortex impair human episodic memory function and impair rat performance in tasks that could be solved by retrieval of trajectories. Recent physiological data suggests a novel model for encoding and retrieval of trajectories, and for associating specific stimuli with specific positions along the trajectory. During encoding in the model, external input drives the activity of head direction cells. Entorhinal grid cells integrate the head direction input to update an internal representation of location, and drive hippocampal place cells. Trajectories are encoded by Hebbian modification of excitatory synaptic connections between hippocampal place cells and ...

2009-07-15

299

Computerized tomography and head growth curve infantile macrocephaly with normal psychomotor development  

Energy Technology Data Exchange (ETDEWEB)

Macrocephaly was defined as a head measuring larger than 98th percentile. We have evaluated CT findings and head growth curves in 25 infants with large heads. Ten (40%) of 25 infants with large heads were normal developmentally and neurologically. Five (20%) of those were mentally retarded. The other 10 infants (40%) included hydrocephalus (4 cases), malformation syndrome (3 cases), brain tumor (1 case), metabolic disorder (1 case) and degenerative disorder (1 case). Their head growth curves were typed as (I), (II) and (III): Type (I) (excessive head growth curve to 2 SDs above normal); Type (II) (head growth curve gradually approached to 2 SDs above normal); Type (III) (head growth curve parallel to 2 SDs above normal). Ten of macrocephaly with normal psychomotor development were studied clinically and radiologically in details. They were all male. CT pictures of those showed ...

1982-01-01

300

Research and Service Experience with Environmentally-Assisted Cracking in Carbon and Low-Alloy Steels in High-Temperature Water  

Energy Technology Data Exchange (ETDEWEB)

The most relevant aspects of research and service experience with environmentally-assisted cracking (EAC) of carbon (C) and low-alloy steels (LAS) in high-temperature (HT) water are reviewed, with special emphasis on the primary pressure boundary components of boiling water reactors (BWRs). The main factors controlling the susceptibility to EAC under light water reactor (LWR) conditions are discussed with respect to crack initiation and crack growth. The adequacy and conservatism of the current BWRVIP-60 stress corrosion cracking (SCC) disposition lines (DLs), ASME III fatigue design curves, and ASME XI reference fatigue crack growth curves, as well as of the GE EAC crack growth model are evaluated in the context of recent research results. The operating experience is summarized and compared to the experimental/mechanistic background knowledge. Finally, open questions and possible topics for further research are identified. ...

2005-11-15

301

AISI/DOE Technology Roadmap Program: Development of Appropriate Resistance Spot Welding Practice for Transformation-Hardened Steels  

Energy Technology Data Exchange (ETDEWEB)

This report describes work accomplished in the project, titled ''Development of Appropriate Resistance Spot Welding Practice for Transformation-Hardened Steels.'' The Phase 1 of the program involved development of in-situ temper diagrams for two gauges of representative dual-phase and martensitic grades of steels. The results showed that tempering is an effective way of reducing hold-time sensitivity (HTS) in hardenable high-strength sheet steels. In Phase 2, post-weld cooling rate techniques, incorporating tempering, were evaluated to reduce HTS for the same four steels. Three alternative methods, viz., post-heating, downsloping, and spike tempering, for HTS reduction were investigated. Downsloping was selected for detailed additional study, as it appeared to be the most promising of the cooling rate control methods. The downsloping maps for each of the candidate steels were used to locate the conditions necessary for the peak response. Three ...

2002-07-08

302

Numerical simulation of progressive inlet orifices in boiling water reactor fuel  

International Nuclear Information System (INIS)

This thesis was carried out at Forsmark Nuclear Power Plant. The power plant in Forsmark consists of three boiling water reactors (BWR) which produce about 17% of Swedish electricity. In a BWR the nuclear reactions are used to boil water inside the reactor vessel. The water works both as a coolant and as a moderator and the resulting steam is used directly to run the turbines. A problem when running a BWR at low flow conditions is the density wave oscillations that might occur to the water flow inside the fuel assemblies. These oscillations arise due to the connection between power and flow rate in a heated channel with two-phase flow. In order to improve the stability performance of the channel an orifice plate is placed at the inlet of each fuel assembly. Today these orifice plates have sharp edges and a constant resistance coefficient. Experimental work has been done with progressive orifices, the edge of which is half-oval in shape. The advantage of progressive orifices is the ...

2004-01-01

303

Water structure as a function of temperature from X-ray scatteringexperiments and ab initio molecular dynamics  

Energy Technology Data Exchange (ETDEWEB)

We present high-quality X-ray scattering experiments on pure water taken over a temperature range of 2 to 77 C using a synchrotron beam line at the advanced light source (ALS) at Lawrence Berkeley National Laboratory. The ALS X-ray scattering intensities are qualitatively different in trend of maximum intensity over this temperature range compared to older X-ray experiments. While the common procedure is to report both the intensity curve and radial distribution function(s), the proper extraction of the real-space pair correlation functions from the experimental scattering is very difficult due to uncertainty introduced in the experimental corrections, the proper weighting of OO, OH, and HH contributions, and numerical problems of Fourier transforming truncated data in Q-space. Instead, we consider the direct calculation of X-ray scattering spectra using electron densities derived from density functional theory based on real-space configurations generated with ...

2003-03-01

304

On the influence of microstructure and carbide content of steels on the electrochemical dissolution process in aqueous NaCl-electrolytes  

Energy Technology Data Exchange (ETDEWEB)

The electrochemical dissolution behaviour of armco-iron and of the steels C15, C45, C60 and 100Cr6 in concentrated sodium chloride media has been investigated. Anodic metal dissolution experiments have been carried out using the flow channel cell (parallel plate reactor), the rotating cylinder electrode (RCE) and the capillary cell. The microstructure of the steel has been varied through variation of carbon content and heat treatment (e.g. soft annealed with globular carbides or pearlitic). Current-efficiency values have been obtained by gravimetric measurements in the current-density range from i=5 to 60 A/cm{sup 2}. For the soft annealed steels, the divalent ferrite dissolution in combination with electroless cementite removal dominates. For the pearlitic steels, the occurrence of oxygen evolution electronically conductive metal carbides or trivalent ferrite dissolution, depending on the current density applied, was detected. Microstructure dependent potentiostatic current transients ...

2002-10-01

305

MRT of carotid stents: influence of stent properties and sequence parameters on visualization of the carotid artery lumen; MRT bei Karotisstens: Einfluss von Stenteigenschaften und Geraeteparametern auf die Darstellbarkeit des Karotislumens  

Energy Technology Data Exchange (ETDEWEB)

Purpose: To evaluate MR artifacts of carotid artery stents and to optimize stent properties and sequence parameters. Material and Methods: Four carotid artery stents - Wallstent (mediloy), Precise (nitinol), ACCULINK (nitinol) and a stent prototype (nitinol) - were investigated in a flow model of the cervical vessels. The model was made of silicon tubing and a flow pump that produces realistic flow curves of the carotid artery. To investigate the effects of magnetic susceptibility and radiofrequency induced shielding artifacts, turbo spin echo and gradient echo sequences as well as CE-MRAs were measured. To improve the visualization of the stent lumen in a CE-MRA, flip angle as well as geometry and covering of the stent prototype were altered. Results: Susceptibility artifacts in stents of the carotid artery only influence the lumen visualization at the proximal and distal end of the braided mediloy stent. A change of stent ...

2005-03-01

306

Korea-Japan joint research on development of seismic capacity evaluation and enhancement technology considering near-fault effect (annual report 2004)  

Energy Technology Data Exchange (ETDEWEB)

In Chapter 2 the evaluation methods of input ground motions for seismic design are summarized and especially the empirical and/or stochastic Green's function method is introduced in order to calculate the broadband strong motions based on the physically reliable fault model. Then the evaluation procedure is applied to the Ulsan fault system near which Wolsung nuclear power plant is located. In chapter3, the PSHA case studies for Wolsung NPP site are performed, in which multi attenuation equations of earthquake motions are adopted. Moreover, the results of seismic hazard evaluation for eight sites in Korea are shown. In addition, the contents of two literatures on seismic hazard evaluation are introduced. In chapter 4, isolation devices for emergency diesel generator have been studied. The models for friction-pendulum system, high damping rubber bearing and natural rubber bearing are developed and implemented in the TDAP-III. Then, the ...

2004-12-01

307

Korea-Japan Joint Research on Development of Seismic Capacity Evaluation and Enhancement Technology Considering Near-Fault Effect (Final Report)  

Energy Technology Data Exchange (ETDEWEB)

We compiled the results of the source analysis obtained under the collaboration research. Recent construction scheme for source modeling adopted in Japan is described, and strong-motion prediction is performed assuming the scenario earthquakes occurring in the Ulsan fault system, Korea. Finally Qs values beneath the Korean inland crust are estimated using strong-motion records in Korea from the 2005 Off West Fukuoka earthquake (M7.0). Probabilistic seismic hazard for four NPP sites in Korea are evaluated, in which the site specific attenuation equations with Index SA developed for NPP sites are adopted. Furthermore, the uniform hazard spectra for the four NPP sites in Korea are obtained by conducting the PSHA by using the attenuation equations with the index of response spectra and seismic source model cases with maximum weights. The supporting tools for seismic response analysis, the evaluation tool for evaluating annual probability of ...

2006-12-15

308

Autoregressive model-based compensation method for the saturated secondary current of a current transformer  

Energy Technology Data Exchange (ETDEWEB)

This paper presented a technique to compensate for distorted secondary currents. Since current distortion can cause operating time delays in protective relays, attempts are made to minimize current transformer (CT) saturation by choosing a CT with a voltage rating that is at least twice that required for the maximum steady-state symmetrical fault current. However, the possibility of saturation still exists because of the DC component of an asymmetrical fault current and the remanent flux in a CT core. An advanced algorithm for the compensation of the distorted signal due to CT saturation was proposed. The secondary current can be expressed as the linear combination of sinusoidal and exponential signals, if no saturation occurs. In this study, the algorithm first utilized the third difference function for detecting the start and end of saturation in real-time. The AR model-based FIR filter and the least mean square curve fitting method were then ...

2006-07-01

309

Nuclear borehole logging using lithium detector assemblies  

International Nuclear Information System (INIS)

A method and apparatus for nuclear borehole logging, and in particular, neutron porosity logging, uses a neutron source, and a pair of spaced lithium detectors, preferably Li"6I crystal or Li"6 doped glass, to detect neutrons emitted from a borehole formation being logged. The spectrum developed by the lithium detectors is processed to remove the gamma ray background radiation and the hydrogen absorption peak, thus allowing a more accurate neutron count. A Gaussian curve is fitted to the neutron peak of the spectrum, the curve eliminating the hydrogen absorption peak. The area under this Gaussian curve represents the neutron count. (author).

1991-11-01

310

New method for determining the energy gap of a superconductor using the maximum in differential conductance of the electron tunneling spectrum  

Energy Technology Data Exchange (ETDEWEB)

This paper presents a new method for the determination of the energy gap of superconductors. The V/sub max//kT versus ..delta../kT curve was calculated from tunneling theory. The maximum voltage in differential conductance V/sub max/ was measured from the electron tunneling spectrum. From V/sub max//kT and the curve, one can easily calculate the energy gap value ..delta... This method is simple, and the accuracy almost approaches that of the curve-fitting method.

1986-07-01

311

New method for determining the energy gap of a superconductor using the maximum in differential conductance of the electron tunneling spectrum  

International Nuclear Information System (INIS)

This paper presents a new method for the determination of the energy gap of superconductors. The V/sub max//kT versus #DELTA#/kT curve was calculated from tunneling theory. The maximum voltage in differential conductance V/sub max/ was measured from the electron tunneling spectrum. From V/sub max//kT and the curve, one can easily calculate the energy gap value #DELTA#. This method is simple, and the accuracy almost approaches that of the curve-fitting method.

312

LET-dependence of the trapping parameters in TLD-100 determined with a computerised curve fitting method  

International Nuclear Information System (INIS)

With a computerized curve fitting method the trapping parameters of TLD-100 chips were calculated after #alpha#-, #beta#- and #gamma#-irradiation. The absorption of radiation produces an additional glow peak at 250 deg C, and the dominant one arises at 280 deg C. After the analysis of the glow curves only a little LET-dependence of the trap depths and that of the half widths was detected. The charge densities after irradiation before heating of the taps responsible for the high temperature glow peaks (T>240 deg C) show a LET-dependence. (author).

1985-10-22

313

Condensing curves for a number of mixed-hydrocarbon working fluids  

Energy Technology Data Exchange (ETDEWEB)

Condensing curves are presented for a number of two-component mixed hydrocarbon working fluids which are potentially usable in binary geothermal cycles. Performance of geothermal thermodynamic cycles incorporating these fluids has been evaluated under separate cover; two figures summarizing the results of those evaluations have been included here for continuity. The purpose of this report is: first, to document the condensing curves which were used in the mixed fluid cycle analyses, and second, to provide background useful in the preliminary evaluation of heat rejection systems for advanced geothermal electric power plants utilizing mixed hydrocarbon working fluids. Some concluding remarks are presented.

1981-07-01

314

Radioimmunoassay determination of the effect on animal reproduction of alternative of feeding suplementation in dairy cows  

International Nuclear Information System (INIS)

The principal object of this trial was to evaluate the influence of three alternatives of feeding suplementation in dairy cows in the post-partum period in ecuadorian highlands. Thirty sic animals in fist lactation were used in this experiment and were divided in three groups according to the feed intake: Group A diet was 5 Kg. of a commercial concentrate mixture with 12 per cent of crude protein plus pasture ad libitum; Group B diet was green banans (Musa paradisiaca) and pasture and Group C diet was the control only pasture. Using Radioimmunoassay technique (RIA), progesterone values were determinated in milk from each cow. the sampling was sequential, two samples a week, starting 6 days after parturition, until the animal was pregnant or until the study was finished, 150 days after post-partum for each cow. This research allowed us to evaluate the ovaric post-partum activity of each group: Frequency and length of the oestrus cycles; efficiency of oestrus ...

315

Milk yield and quality in Guernsey cows fed cottonseed cake-based diets partially substituted with baobab (Adansonia digitata L.) seed cake  

British Library Electronic Table of Contents (United Kingdom)

The objective of this study was to determine the effects of partially substituting cottonseed cake with graded levels of baobab (Adansonia digitata L.) seed cake (BSC) on milk yield and quality in Guernsey cows. Sixteen cows in mid-lactation and in their third parity were allocated to diets containing 0% (control), 5%, 10%, and 15% BSC in a completely randomized design. Each cow was given a daily feed ration of 6?kg and a basal diet of soya bean stover ad libitum. There were no differences in daily feed intake (P?>?0.05), but basal intake differed among all treatment groups with cows on the control diet having the highest intake (30???0.34?kg/day). Mean daily milk yield differed (P?P?P?P?P?>?0.05). These results indicate that BSC can substitute soya bean cake in dairy diets, but milk produ...

2011-01-01

316

L'exercice physique d'endurance est plus efficace que l'exercice aerobie pour le controle par la pression arterielle sur 24heures chez des diabetiques de type 2  

British Library Electronic Table of Contents (United Kingdom)

Aim: The study aimed to analyze blood pressure (BP) responses in individuals with type 2 diabetes (T2D) over a 24h period following resistance (RES) and aerobic (AER) exercise. Methods: Ten adults with T2D (age: 55.8+/-7.7 years; weight: 79.4+/-14.0kg; fasting glucose: 133.0+/-36.7mg.dL^-^1) underwent: (1) AER: 20min of cycling at 90% lactate threshold (90% LT); (2) RES: three laps of a circuit of six exercises with eight repetitions at 70% 1-RM and 40s of recovery; and (3) a control session of no exercise. Heart rate (HR), and systolic (SBP), diastolic (DBP), mean arterial (MAP) and pulse (PP) BP, as well as lactataemia (Lac), VO2, respiratory exchange ratio (RER) and rate of perceived exertion (RPE) were measured at rest, during exercise and control (CON) periods, and 60min after interve...

2011-01-01

317

Homo-d-lactic acid production from mixed sugars using xylose-assimilating operon-integrated Lactobacillus plantarum  

British Library Electronic Table of Contents (United Kingdom)

In order to achieve efficient d-lactic acid fermentation from a mixture of xylose and glucose, the xylose-assimilating xylAB operon from Lactobacillus pentosus (PXylAB) was introduced into an l-lactate dehydrogenase gene (ldhL1)-deficient Lactobacillus plantarum (?ldhL1-xpk1::tkt-?xpk2) strain in which the phosphoketolase 1 gene (xpk1) was replaced with the transketolase gene (tkt) from Lactococcus lactis, and the phosphoketolase 2 (xpk2) gene was deleted. Two copies of xylAB introduced into the genome significantly improved the xylose fermentation ability, raising it to the same level as that of ?ldhL1-xpk1::tkt-?xpk2 harboring a xylAB operon-expressing plasmid. Using the two-copy xylAB integrated strain, successful homo-d-lactic acid production was achieved from a mixture of 25?g/l xylos...

2011-01-01

318

Evaluation of magnetization transfer ratios for breast tissues and breast diseases  

Energy Technology Data Exchange (ETDEWEB)

To determine MTRs for normal structures and benign diseases in the breast two-dimensional magnetization transfer imaging was performed in 62 patients and in 3 young female volunteers. With regard to the MTRs of measurements in the normal breast tissues, fat tissues which is close to simple cysts in MTRs show little transfer of longitudinal magnetization. MTRs of the muscles was 15.15{+-}6.22%, which exceeded those of breast parenchyma. The breast parenchyma didn`t show the change of MTR value due to the difference of patient age and due to variable amount of fat and fibrous tissues. Breast parenchyma in the two young volunteers clearly showed biphasic change of MTR values in accordance with the menstrual cycle; little transfer value was due to hydration in the postovulatory period and high transfer value was due to dehydration in the preovulatory period. In the remaining one volunteer during lactation period, mammary parenchyma shows sever decrease in MTR, because ...

1997-03-01

319

Crystal structure of Spot 14, a modulator of fatty acid synthesis  

Energy Technology Data Exchange (ETDEWEB)

Spot 14 (S14) is a protein that is abundantly expressed in lipogenic tissues and is regulated in a manner similar to other enzymes involved in fatty acid synthesis. Deletion of S14 in mice decreased lipid synthesis in lactating mammary tissue, but the mechanism of S14's action is unknown. Here we present the crystal structure of S14 to 2.65 {angstrom} and biochemical data showing that S14 can form heterodimers with MIG12. MIG12 modulates fatty acid synthesis by inducing the polymerization and activity of acetyl-CoA carboxylase, the first committed enzymatic reaction in the fatty acid synthesis pathway. Coexpression of S14 and MIG12 leads to heterodimers and reduced acetyl-CoA carboxylase polymerization and activity. The structure of S14 suggests a mechanism whereby heterodimer formation with MIG12 attenuates the ability of MIG12 to activate ACC.

2011-09-06

320

Complexation study on no-carrier-added astatine with insulin: A candidate radiopharmaceutical  

Energy Technology Data Exchange (ETDEWEB)

No-carrier-added astatine radionuclides produced in the {sup 7}Li-irradiated lead matrix were separated from bulk lead nitrate target by complexing At with insulin, followed by dialysis. The method offers simultaneous separation of At from lead as well as its complexation with insulin. The At-insulin complex might be a potential radiopharmaceutical in the treatment of hepatocellular carcinoma. The stability of At-insulin complex was checked by dialysis against deionized water and Ringer lactate (RL) solution. It has been found that the half-life of At-insulin complex is about {approx}12 h, when dialyzed against deionized water and is only 6 h, when dialyzed against RL solution having the same composition as blood serum. The 6 h half-life of this Insulin-At complex is perfect for killing cancer cells from external cell surfaces as the half-life of internalization of insulin molecule inside the cell is 7-12 h.

2008-12-15

321

Complexation study on no-carrier-added astatine with insulin: A candidate radiopharmaceutical  

International Nuclear Information System (INIS)

No-carrier-added astatine radionuclides produced in the "7Li-irradiated lead matrix were separated from bulk lead nitrate target by complexing At with insulin, followed by dialysis. The method offers simultaneous separation of At from lead as well as its complexation with insulin. The At-insulin complex might be a potential radiopharmaceutical in the treatment of hepatocellular carcinoma. The stability of At-insulin complex was checked by dialysis against deionized water and Ringer lactate (RL) solution. It has been found that the half-life of At-insulin complex is about #approx#12 h, when dialyzed against deionized water and is only 6 h, when dialyzed against RL solution having the same composition as blood serum. The 6 h half-life of this Insulin-At complex is perfect for killing cancer cells from external cell surfaces as the half-life of internalization of insulin molecule inside the cell is 7-12 h.

2008-12-01

322

User's Guide - NSSDC - NASA  

Science.gov (United States)

F4.1 . MONOTON. Increasing . FILLVAL ... Interface is easier-to-use and requires a much shorter learning curve than the Internal Interface, ...

323

Ultimate Compressive Strength and Nonlinear Stress-Strain ...  

Science.gov (United States)

... Accession Number : ADD421949. Title : Ultimate Compressive Strength and Nonlinear Stress-Strain Curves of Graphite/Epoxy Laminates,. ...

1976-10-12

324

TEST PLANNING APPROACH AND LESSONS. - NASA Technical Report Server ...  

Science.gov (United States)

requirements) + f3(accuracy of analyses) + f4(accuracy of fabrication) + f5( design time) + .... Learning curves suggest an evolution in rocket engines& ...

325

SPACE ACT AGREEMENT FOR COTS - NASA  

Science.gov (United States)

F4. Totai Cost by System. Two K-l's will be built to assure successful COTS Demos. ...... has started that learning curve.with the Falcon 1 first stage. ...

326

New symmetry of intended curved reaches  

UK PubMed Central (United Kingdom)

BackgroundMovement regularities are inherently present in automated goal-directed motions of the primate's arm system. They can provide important signatures of intentional behaviours...Full Text Available

327

Neural Learning of Predicting Driving Environment  

Science.gov (United States)

... This paper presents our research in neural learning for predicting ... Denote this feature set as F4. ... can be observed that the SOC curves generated by ...

2008-06-01

328

NI\\S/\\ - NASA Technical Report Server (NTRS)  

Science.gov (United States)

The first point in the learning curve has been obtained. REFERENCES ..... Lens 4 is selected such that l/fl=1/f4+1/x, where x is ...

329

Identification of fatigue damage in cortical bone by diffraction enhanced imaging  

International Nuclear Information System (INIS)

In an effort to explore Diffraction Enhanced Imaging of bone tissue, experiments were performed to determine if it was possible to use Diffraction Enhanced Imaging to detect microdamage in bovine cortical bone. Measurements were made at the National Synchrotron Light Source where pre- and post-fatigue rocking curve widths of the bone were studied. The rocking curve widths were then compared. Since no consistent pattern of narrowing or broadening of the rocking curve emerged, it is likely that the ultra-small-angle X-ray scattering present in the bone overshadowed any additional changes to rocking curve caused by microdamage of the bone. Larger bone structures were able to be visualized which suggests that microdamage may be visualized with a higher resolution detector.

2005-08-11

330

Eighth Goddard Conference on Mass Storage Systems and Technologies ...  

Science.gov (United States)

f4 f5 f1 f2. (a) Overall process decompress ...... involved the shortest learning curve, was available on several platforms, and was ...

331

CIVIL USES OF REMOTELY PILOTED AIRCRAFT' - NASA Technical Report ...  

Science.gov (United States)

to, an altitude of 5000 ft (1500 m) AGL and f4.ies tight circles. If link has ...... The learning-curve effect reflects the observable ...

332

Appendix F. List of citations accepted and rejected by ...  

Science.gov (United States)

... F4 ... Sublethal Toxicity of Nine Pesticides on Olfactory Learning Performances of ... Daphnia and Preparation of Dosage- Mortality Curves for Pesticides ...

2008-02-21

333

Algebraic complexities and algebraic curves over finite fields  

UK PubMed Central (United Kingdom)

We consider the problem of minimal (multiplicative) complexity of polynomial multiplication and multiplication in finite extensions of fields. For infinite fields minimal complexities are known [Winograd,...Full Text Available

1987-04-01

334

Advanced distillation curve measurement: Application to a bio-derived crude oil prepared from swine manure  

British Library Electronic Table of Contents (United Kingdom)

We have recently introduced several important improvements in the measurement of distillation curves for complex fluids. This new method is a significant improvement over current approaches, with features including a composition-explicit data channel for each distillate fraction (for both qualitative and quantitative analysis), trace chemical analysis of each distillate fraction, and a corrosivity assessment of each distillate fraction. In the present contribution, we present the application of the advanced distillation curve method to a bio-derived crude oil prepared from swine manure. One motivation behind the work was to precisely measure the distillation curve of the oil derived from swine manure with our advanced distillation apparatus and compare the bio-derived oil to traditional pe...

2008-01-01

335

A Worst-case Bound for Topology Computation of Algebraic Curves  

CERN Document Server

Computing the topology of an algebraic plane curve $\\mathcal{C}$ means to compute a combinatorial graph that is isotopic to $\\mathcal{C}$ and thus represents its topology in $\\mathbb{R}^2$. We prove that, for a polynomial of degree $n$ with coefficients bounded by $2^\\rho$, the topology of the induced curve can be computed with $\\tilde{O}(n^8(n+\\rho^2))$ bit operations deterministically, and with $\\tilde{O}(n^8\\rho^2)$ bit operations with a randomized algorithm in expectation. Our analysis improves previous best known complexity bounds by a factor of $n^2$. The improvement is based on new techniques to compute and refine isolating intervals for the real roots of polynomials, and by the consequent amortized analysis of the critical fibers of the algebraic curve.

2011-01-01

336

TYPE Ib/c SUPERNOVAE IN BINARY SYSTEMS. I. EVOLUTION AND PROPERTIES OF THE PROGENITOR STARS  

International Nuclear Information System (INIS)

We investigate the evolution of Type Ib/c supernova (SN Ib/c) progenitors in close binary systems, using new evolutionary models that include the effects of rotation, with initial masses of 12-25 M_s_u_n for the primary components, and of single helium stars with initial masses of 2.8-20 M_s_u_n. We find that, despite the impact of tidal interaction on the rotation of primary stars, the amount of angular momentum retained in the core at the presupernova stage in different binary model sequences converges to a value similar to those found in previous single star models. This amount is large enough to produce millisecond pulsars, but too small to produce magnetars or long gamma-ray bursts. We employ the most up-to-date estimate for the Wolf-Rayet mass-loss rate, and its implications for SN Ib/c progenitors are discussed in detail. In terms of stellar structure, SN Ib/c progenitors in binary systems at solar metallicity are ...

2010-12-10

337

FDS3 simulations of indoor hydrocarbon fires engulfing radioactive waste packages  

International Nuclear Information System (INIS)

The thermal environment of a hypothetical large indoor hydrocarbon pool fire is more complex compared to outdoor fires and can be more severe for engulfed objects. In order to analyze potential thermal environments for interim storage of spent fuel casks or low-level radioactive waste packages engulfed in pool fires numerical simulations with the CFD fire code FDS3 were carried out for different storage configurations. In addition, data of indoor pool fire experiments were used to validate the model for this type of application. A series of pool fire experiments under different ventilation conditions and varied pool surface (1 m"2 - 4 m"2) inside a compartment of 3.6 m x 3.6 m x 5.7 m was conducted at iBMB (Institut fuer Baustoffe, Massivbau und Brandschutz) of Braunschweig University of Technology, Germany. The instrumentation included thermocouples, heatflux and pressure gauges, bi-directional flow probes and gas concentration measurements. A mock low-level waste ...

2004-09-20

338

S-N curves for welded tubular joints  

Energy Technology Data Exchange (ETDEWEB)

The objective of the project was to develop a welded tubular joint database to assess the fatigue design curves (X and X{prime}) in the American Petroleum Institute design code (API RP2A). Changes in the curve-fitting method and screening criteria (primarily the exclusion of the very thin tubular joints) produced results different from those reported previously. The current results show that the X and X{prime} curves are too conservative and that a new curve should be adopted. The Department of Energy T{prime} curve was found to be consistent with the screened tubular joint air data and is recommended for use in API RP2A. The weldment size effect exponent (n) of 0.25 in the current version of API RP2A was found to be too small, and a higher value of 0.30 consistent with the Department of Energy recommendations is recommended. The fatigue test results for tubular joints tested in air ...

1995-12-31

339

Performance of a large Bragg-curve spectrometer  

Energy Technology Data Exchange (ETDEWEB)

A large Bragg-curve spectrometer has been constructed and tested. The detector has a cylindrical geometry and operates with a homogeneous electric field. Energy resolutions of <0.8% and Z resolutions of Z/..delta..Z=80 have been achieved for eleastically scattered /sup 58/Ni ions. These results demonstrate the suitability of this large solid-angle detector for use in a wide variety of heavy-ion scattering experiments.

1987-04-01

340

Performance of a large Bragg-curve spectrometer  

International Nuclear Information System (INIS)

A large Bragg-curve spectrometer has been constructed and tested. The detector has a cylindrical geometry and operates with a homogeneous electric field. Energy resolutions of <0.8% and Z resolutions of Z/#DELTA#Z=80 have been achieved for eleastically scattered "5"8Ni ions. These results demonstrate the suitability of this large solid-angle detector for use in a wide variety of heavy-ion scattering experiments. (orig.).

341

Particle identification through the measurement of the Bragg curve centroid  

Energy Technology Data Exchange (ETDEWEB)

A new method of particle identification of heavy ions through the measurement of the Bragg curve centroid and particle energy has been developed using a gas ionization chamber with a resistive anode layer. Z-resolutions comparable to the conventional ..delta..E-E counter telescope could be rather easily attained.

1983-07-01

342

Particle identification through the measurement of the Bragg curve centroid  

International Nuclear Information System (INIS)

A new method of particle identification of heavy ions through the measurement of the Bragg curve centroid and particle energy has been developed using a gas ionization chamber with a resistive anode layer. Z-resolutions comparable to the conventional #DELTA#E-E counter telescope could be rather easily attained. (orig.).

343

Particle identification by modified Bragg-curve centroid detection  

Energy Technology Data Exchange (ETDEWEB)

A new article identification method based on the measurement of Bragg-curve centroids using a gas-filled ionization chamber has been improved for detection of low-energy particles around 1 MeV per nucleon by introducing a nonuniform distribution of resistance on the anode electrode. Almost the same quality of Z-resolutions as in the conventional ..delta..E-E method could be obtained up to Z=19.

1987-03-01

344

Optimization of lead content in bismuth (2223) superconductor  

International Nuclear Information System (INIS)

In the present study the Pb content in Bi(2223) phase by regression or curve fitting method are optimized. The best fitting curve can be obtained by the method of least square. To study the effect of Pb content in Pb substituted Bi (2223) superconductors, prepared by solid state reaction method data is obtained. The deviation of T_c from the target value for different Pb content is summarized

2003-01-29

345

Nitrogen isotope identification by Bragg-curve spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

Projectilelike fragments following the 80 MeV /sup 16/O+/sup 27/Al reaction have been detected using a Bragg-curve spectroscopy ionization chamber (BCS-IC). The atomic number is deduced from the Bragg-peak amplitude. Nitrogen isotopes are clearly resolved using either range or energy loss data. This is the first application of the BCS method for complete ion identification in a heavy-ion-induced reaction.

1984-07-14

346

Nitrogen isotope identification by Bragg-curve spectroscopy  

International Nuclear Information System (INIS)

Projectilelike fragments following the 80 MeV "1"6O+"2"7Al reaction have been detected using a Bragg-curve spectroscopy ionization chamber (BCS-IC). The atomic number is deduced from the Bragg-peak amplitude. Nitrogen isotopes are clearly resolved using either range or energy loss data. This is the first application of the BCS method for complete ion identification in a heavy-ion-induced reaction.

347

Magnetization and magnetostriction curves for highly magnetostrictive materials  

Energy Technology Data Exchange (ETDEWEB)

The macroscopic behavior of magnetostrictive materials results from domain evolutions occurring at a microscopic scale. The author shows how to compute magnetization and magnetostriction curves by appraising the behavior of the underlying microstructures. The method hinges on an averaging device (Young measures), which allows one to pass from the microscopic to the macroscopic scale. He takes into account the kinematical constraints on the accommodation of elastic effects, and he highlights the role of material symmetry in the selection of energetically optimal microstructures.

1994-12-31

348

Energy intensity, CO{sub 2} emissions and the environmental Kuznets curve. The Spanish case  

Energy Technology Data Exchange (ETDEWEB)

This article analyses the role of energy intensity and the relationship between CO{sub 2} emissions and primary energy in order to explain the evolution of CO{sub 2} emissions by unit of real GDP. It also distinguishes two different meanings of CO{sub 2} emissions Kuznets curve hypothesis: the weak and the strong sense. It considers the case of Spain in the period 1972-1997 as an example in which there is not any evidence supporting this hypothesis in either sense. (author)

2001-06-01

349

Dissociation energies of HfO and ThO  

International Nuclear Information System (INIS)

The RKR potential energy curves are constructed for the ground states of diatomic hafnium oxide and thorium oxide. Using Lippincott and Hulburt-Hirschfelder potential function the dissociation energies are estimated by curve fitting method. The H-H potential function was found to give a better fit in both cases. The dissociation energies of hafnium oxide and thorium oxide are estimated as 9.04 #+-# 0.02 eV and 10.34 #+-# 0.01 eV respectively. (author).

350

Bragg curve spectroscopy in a 4? geometry  

Science.gov (United States)

Ionization counters employing Bragg curve spectroscopy have been constructed for use in a 4? geometry. These detectors compare very favorably in terms of both energy and charge resolution with small solid angle devices. These detectors have a large dynamic range because they are backed by scintillation detectors, and are thus capable of detecting and identifying particles with energies from 1 MeV/nucleon up to 200 MeV/nucleon.

1991-02-01

351

Bragg curve spectroscopy in a 4. pi. geometry  

Energy Technology Data Exchange (ETDEWEB)

Ionization counters employing Bragg curve spectroscopy have been constructed for use in a 4{pi} geometry. These detectors compare very favorably in terms of both energy and charge resolution with small solid angle devices. These detectors have a large dynamic range because they are backed by scintillation detectors, and are thus capable of detecting and identifying particles with energies from 1 MeV/nucleon up to 200 MeV/nucleon. (orig.).

1991-02-01

352

Bragg curve spectroscopy in a 4#pi# geometry  

International Nuclear Information System (INIS)

Ionization counters employing Bragg curve spectroscopy have been constructed for use in a 4#pi# geometry. These detectors compare very favorably in terms of both energy and charge resolution with small solid angle devices. These detectors have a large dynamic range because they are backed by scintillation detectors, and are thus capable of detecting and identifying particles with energies from 1 MeV/nucleon up to 200 MeV/nucleon. (orig.).

353

Bragg curve spectroscopy detector for particle identification  

International Nuclear Information System (INIS)

The operation principle, construction and characteristics of the Bragg curve spectroscopy detector (BCS detector) are described. The electric field of the BCS detector is parallel to the particle trajectories. The detector was tested by 8.78 MeV and 6.02 MeV #alpha# particles from a ThC-ThC's source. The energy resolutions are 1.5% and 2.6% respectively for two groups of #alpha# particles, and the charge resolution is 2.7%. Further test experiments with heavy ions will be arranged.

354

Application of neural networks to pulse-shape analysis of Bragg curves  

Energy Technology Data Exchange (ETDEWEB)

A novel approach is presented to extract relevant parameters associated with the energy loss of ejectiles from nuclear reactions obtained by digitizing the signals of a Bragg curve spectrometer. New and more powerful computational paradigms allow a more thorough pulse-shape analysis. This is fulfilled using a back-propagation artificial neural network as a pattern identifier. The known problem of over-training is discussed.

2006-01-15

355

Analysis of TL glow curves in differently doped LiF:Mg,Ti  

International Nuclear Information System (INIS)

A computerised curve-fitting method was developed to calculate the trapping parameters in LiF TLD-100 and LiF:Mg, Ti. After irradiation in a "6"0Co field and with X rays emitted at different voltages the TL process is best described by first-order kinetics. A dependence of the trapping parameters on both the concentration of Mg and Ti and photon energy was detected. (author).

356

A large-acceptance Bragg curve spectrometer with a longitudinal electric field and a segmented anode  

Energy Technology Data Exchange (ETDEWEB)

A large-acceptance Bragg curve spectrometer with a longitudinal electron collection field and a segmented anode has been constructed and tested. The effects on the charge resolution of the entrance angle and entrance position of the incident particle have been studied. Simulations have been done in order to isolate the contribution to the overall detector performance of the signal-shaping electronics from that of the intrinsic design of the detector. ((orig.))

1994-07-15

357

Therapeutic efficacy of intralesional 131I-labelled hyaluronectin in grafted human glioblastoma  

Energy Technology Data Exchange (ETDEWEB)

The grafted human glioblastoma cell CB109 was used as a model for intralesional therapy with 131I-labelled hyaluronectin glycoprotein (131I-HN). 131I-HN bound specifically to in situ hyaluronic acid (HA), a main component of the extracellular matrix which is involved in tumour invasion. Labelling experimental conditions were determined and, finally, 25 {mu}Ci/{mu}gHN, 1 {mu}g chloramine-T/{mu}gHN and a 60-s stirring period provided a 131I-HN preparation with an optimal affinity for HA (64% compared to unlabelled HN). Following intratumoral injection, 131I-HN was retained with a limited diffusion outside the tumour. On day 4 the radioactivity concentrated in the tumour was still 25 times greater than that in the liver, spleen and kidneys combined. For therapeutic assays, 65 {mu}Ci 131I-HN was injected into the tumour, resulting in a delivery of 6.8 Gy over a 7-day period. Controls received unlabelled HN, heat-inactivated HN, a mixture of inactivated HN plus free ...

2000-07-01

358

The calibration of sub-Coulomb heavy ion proton transfer reactions  

Energy Technology Data Exchange (ETDEWEB)

Measurements were made of the cross sections for the /sup 27/Al(/sup 16/O,/sup 15/N)/sup 28/Si, /sup 89/Y(/sup 15/N,/sup 16/O)/sup 88/Sr and /sup 89/Y(/sup 27/Al,/sup 28/Si)/sup 88/Sr reactions at energies near and below the Coulomb barrier. The first reaction required separate measurements of the transfer to elastic cross section ratio for particular charge states, the charge state distribution for /sup 27/Al and /sup 28/Si ions, and the absolute elastic scattering cross section for the /sup 27/Al + /sup 16/O system. The ratio measurement required the combined use of two relatively new scientific instruments: the momentum filter and the Bragg curve spectrometer. The latter two transfer measurements were performed using the same setup involving surface barrier detectors at backward angles. Additional elastic scattering data for the /sup 15/N + /sup 28/Si, /sup 89/Y + /sup 15/N, /sup 89/Sr + /sup 27/Al, and /sup 88/Sr + /sup 28/Si systems was collected to provide ...

1987-01-01

359

Spectral absorption properties of colored dissolved organic matter (CDOM) and total suspended matter (TSM) of inland waters  

Science.gov (United States)

Spectral absorption properties of total suspended matter (TSM) and colored dissolved organic matter (CDOM) are important for the use of the bio-optical model to estimate water quality parameters. This study aims to investigate the variation in the absorption coefficients of TSM and CDOM of inland waters. A total of 92 water samples were collected from Shitoukoumen Reservoir and Songhua Lake in Northeast China, analyzed for TSM and Chl-a, and measured for the absorption coefficient of TSM, CDOM and total pigments using a laboratory spectrophotometer. The absorption coefficient of TSM has been decomposed for phytoplankton and inorganic sediments. The results show that for Shitoukoumen Reservoir, CDOM has strong absorptions with shallow absorption slopes (i.e., the coefficient S in a(?)=a(?0)exp[-S(?- ?0)]) and large absorption at 355 nm; and for Songhua Lake, CDOM follows similar spectral absorption curves but less variation in the S value. The ...

2010-08-01

360

Optimizing the fMRI data-processing pipeline using prediction and reproducibility performance metrics: I. A preliminary group analysis.  

Science.gov (United States)

We argue that published results demonstrate that new insights into human brain function may be obscured by poor and/or limited choices in the data-processing pipeline, and review the work on performance metrics for optimizing pipelines: prediction, reproducibility, and related empirical Receiver Operating Characteristic (ROC) curve metrics. Using the NPAIRS split-half resampling framework for estimating prediction/reproducibility metrics (Strother et al., 2002), we illustrate its use by testing the relative importance of selected pipeline components (interpolation, in-plane spatial smoothing, temporal detrending, and between-subject alignment) in a group analysis of BOLD-fMRI scans from 16 subjects performing a block-design, parametric-static-force task. Large-scale brain networks were detected using a multivariate linear discriminant analysis (canonical variates analysis, CVA) that was tuned to fit the data. We found that tuning the CVA model ...

2004-01-01

361

Investigations on process design and fuel substitution in a cokeless, natural-gas-fuelled cupola furnace; Untersuchung zur Prozessgestaltung und Brennstoffsubstitution an einem kokslosen erdgasbefeuerten Kupolofen (KLKO)  

Energy Technology Data Exchange (ETDEWEB)

A process model is presented and used for identifying options for controlling the cupola furnace process and for investigating natural gas substitutes. Fuel substitution will affect temperature curves (i.e. tapping temperatures and melting capacity), outlet temperatures and gas mass flow out of the preheating zone. The contribution presents several process variations to overcome these problems and compares them with the natural gas process. [German] Mit dem Prozessmodell werden zunaechst Moeglichkeiten der Steuerung von Abstichtemperatur und Schmelzleistung, insbesondere unter Beruecksichtigung der Schrottqualitaet (spezifische Oberflaeche a{sub G}), untersucht. Es wird gezeigt, dass das Prozessmodell die Ergebnisse aus der Praxis wiedergibt. Daran anschliessend wird mit dem Prozessmodell die Substitution von Erdgas durch minderwertige Gase untersucht (Brennstoffsubstitution, Ressourcenschonung). Durch die Brennstoffsubstitution veraendern sich ...

2001-07-01

362

Influence of plasma nitriding on fatigue strength and fracture of a B-Mn steel  

Energy Technology Data Exchange (ETDEWEB)

The first part of a systematic investigation is presented of surface treatments affecting the fatigue behavior of smooth and notched quenched and tempered (Q and T) specimens made of a B-Mn SS2131 ({approx}AISI 15B21H) steel. In this part, the effects of plasma nitriding (nitriding temperature=480 C, time=24 h) on the fatigue strength and notch sensitivity were investigated. Constant stress amplitude plane reversed bending fatigue tests (R=-1) at 47 Hz were conducted using cylindrical plasma nitriding (PN) and Q and T steel specimens with K{sub t}=1.05 and 1.7. The compound layer was found to consists of {epsilon}-phase and {gamma}`-phase. S-N curves show that plasma nitriding improves the fatigue limit by 53 and 115% of Q and T smooth and notched specimens, respectively. The fatigue strength of smooth specimens is improved through the whole fatigue life but only for long fatigue lives for notched specimens. Plasma nitriding reverses the low notch sensitivity (at ...

1998-02-01

363

Hydroxo-species of uranium (VI) in aqueous media  

International Nuclear Information System (INIS)

The large degree of confusion and many contradictions which are evident in the literature regarding the dioxo-uranium(VI)-hydroxide system has prompted the re-investigation of the hydrolysis of UO_2"2"- in aqueous media. The hydrolysis reactions of the uranyl ion have been investigated by potentiometric (pH)-, spectrophotometric- and conductometric titrations of uranyl chloride solutions with sodium hydroxide solutions. In all these titrations two clearly defined endpoints were obtained, indicating the predominance in solution of only a limited number of species. From a consideration of all the experimentally obtained data the following set of species was proposed to be present in significant concentrations in the pH range 0 to 12: UO_2"2"-, (UO_2)_2(OH)_2"2"-, (UO_2)_2(OH)_3"- and (UO_2)_9(OH)_1_9"-. By using the proposed set of species, a mathematical model of the uranyl-hydroxo system was developed with which the titration curves obtained by ...

1600-01-01

364

Evaluation of the flow forces on a direct (single stage) proportional valve by means of a computational fluid dynamic analysis  

International Nuclear Information System (INIS)

The aim of this paper is to investigate the fluid dynamic behaviour of a commercial hydraulic proportional valve in order to evaluate and justify its global performances and, in particular, to analyze the effects of some additional design features on the reduction of the force required to maintain the valve open. The proposed analysis has been performed by applying the commercial computational fluid dynamics (CFD) code, Fluent, to the solution of the three dimensional turbulent flow field through a circumferential sector of the entire valve for different spool strokes. The reliability of the employed modelization is demonstrated by the comparison between the computed flow rate curve and the corresponding experimental data provided by the manufacturer. With regard to the metering edge design, it is shown that the cylindrical hole provided on the top of the hemi-spherical notch to improve metering at small valve openings has no influence on the ...

2007-03-01

365

Enhanced corrosion resistance properties of radiofrequency cold plasma nitrided carbon steel: Gravimetric and electrochemical results  

Energy Technology Data Exchange (ETDEWEB)

Cold plasma nitriding treatment was performed to improve the corrosion resistance of C38 carbon steel. Nitriding process was conducted using a radiofrequency nitrogen plasma discharge for different times of treatment on non-heated substrates. The modification of the corrosion resistance characteristic of the C38 steel due to the treatment in acid medium (1 M HCl) were investigated by gravimetric and electrochemical tests such as potentiodynamic polarisation curves and electrochemical impedance spectroscopy (EIS). It was shown that the plasma nitriding treatment improves the corrosion resistance. Indeed, in the gravimetric tests, nitrided samples showed lower weight loss and lower corrosion rate in comparison to untreated one. In the Tafel polarisation tests, the nitrided samples showed greatly reduced corrosion current densities, anodic dissolution and also retarded the hydrogen evolution reaction. Using EIS method, an adequate structural model ...

2009-03-01

366

Dosimetric validation of the anisotropic analytical algorithm for photon dose calculation: fundamental characterization in water  

International Nuclear Information System (INIS)

In July 2005 a new algorithm was released by Varian Medical Systems for the Eclipse planning system and installed in our institute. It is the anisotropic analytical algorithm (AAA) for photon dose calculations, a convolution/superposition model for the first time implemented in a Varian planning system. It was therefore necessary to perform validation studies at different levels with a wide investigation approach. To validate the basic performances of the AAA, a detailed analysis of data computed by the AAA configuration algorithm was carried out and data were compared against measurements. To better appraise the performance of AAA and the capability of its configuration to tailor machine-specific characteristics, data obtained from the pencil beam convolution (PBC) algorithm implemented in Eclipse were also added in the comparison. Since the purpose of the paper is to address the basic performances of the AAA and of its configuration procedures, only data relative ...

2006-03-21

367

Dose proportionality and the effect of food on vildagliptin, a novel dipeptidyl peptidase IV inhibitor, in healthy volunteers.  

Science.gov (United States)

Vildagliptin is a potent and selective dipeptidyl peptidase IV inhibitor in development for the treatment of type 2 diabetes that improves glycemic control by enhancing alpha- and beta-cell responsiveness to glucose. Two open-label, single-dose, randomized, crossover studies in healthy subjects (ages 18-45 years) investigated the dose proportionality of vildagliptin pharmacokinetics (n = 20) and the effect of food (n = 24) on vildagliptin pharmacokinetics. There was a linear relationship (r(2) = 0.999) between vildagliptin doses of 25, 50, 100, and 200 mg and area under the plasma concentration-time curve from time zero to infinity (AUC(0-infinity)) and maximum plasma concentration (C(max)). Dose proportionality was assessed using a statistical power model [X = alpha x (dose)(beta)]. The 90% confidence intervals of the proportionality coefficient, beta, for AUC(0-infinity) (1.15-1.19) and C(max) (1.04-1.14) indicated that deviations from dose ...

2007-07-26

368

Development of experimental verification techniques for non-linear deformation and fracture on the nanometer scale.  

Energy Technology Data Exchange (ETDEWEB)

This work covers three distinct aspects of deformation and fracture during indentations. In particular, we develop an approach to verification of nanoindentation induced film fracture in hard film/soft substrate systems; we examine the ability to perform these experiments in harsh environments; we investigate the methods by which the resulting deformation from indentation can be quantified and correlated to computational simulations, and we examine the onset of plasticity during indentation testing. First, nanoindentation was utilized to induce fracture of brittle thin oxide films on compliant substrates. During the indentation, a load is applied and the penetration depth is continuously measured. A sudden discontinuity, indicative of film fracture, was observed upon the loading portion of the load-depth curve. The mechanical properties of thermally grown oxide films on various substrates were calculated using two different numerical methods. The first method ...

2005-11-01

369

Crack growth rates and fracture toughness of irradiated austenitic stainless steels in BWR environments.  

Energy Technology Data Exchange (ETDEWEB)

In light water reactors, austenitic stainless steels (SSs) are used extensively as structural alloys in reactor core internal components because of their high strength, ductility, and fracture toughness. However, exposure to high levels of neutron irradiation for extended periods degrades the fracture properties of these steels by changing the material microstructure (e.g., radiation hardening) and microchemistry (e.g., radiation-induced segregation). Experimental data are presented on the fracture toughness and crack growth rates (CGRs) of wrought and cast austenitic SSs, including weld heat-affected-zone materials, that were irradiated to fluence levels as high as {approx} 2x 10{sup 21} n/cm{sup 2} (E > 1 MeV) ({approx} 3 dpa) in a light water reactor at 288-300 C. The results are compared with the data available in the literature. The effects of material composition, irradiation dose, and water chemistry on CGRs under cyclic and stress corrosion cracking conditions were ...

2008-01-21

370

Biosorption of heavy metals  

Energy Technology Data Exchange (ETDEWEB)

Only within the past decade has the potential of metal biosorption by biomass materials been well established. For economic reasons, of particular interest are abundant biomass types generated as a waste byproduct of large-scale industrial fermentations or certain metal-binding algae found in large quantities in the sea. These biomass types serve as a basis for newly developed metal biosorption processes foreseen particularly as a very competitive means for the detoxification of metal-bearing industrial effluents. The assessment of the metal-building capacity of some new biosorbents is discussed. Lead and cadmium, for instance, have been effectively removed from very dilute solutions by the dried biomass of some ubiquitous species of brown marine algae such as Ascophyllum and Sargassum, which accumulate more than 30% of biomass dry weight in the metal. Mycelia of the industrial steroid-transforming fungi Rhizopus and Absidia are excellent biosorbents for lead, cadmium, copper, zinc, ...

1995-05-01

371

Survey of Families with Children  

Wastenet

heterogeneity bias Static models: Other models:

372

Statistical modelling for social researchers principles and practice  

CERN Document Server

Statistical modelling for social researchers

2008-01-01

373

In vitro H2AX phosphorylation and micronuclei induction in human fibroblasts across the Bragg curve of a 577MeV/nucleon Fe incident beam  

Energy Technology Data Exchange (ETDEWEB)

The space environment consists of a varying field of radiation particles including high-energy ions, with spacecraft shielding material providing the only major protection to astronauts from harmful exposure. Unlike low-linear energy transfer (LET) {gamma} or X-rays, the presence of shielding does not always reduce the radiation risks for energetic charged particle exposure, since the dose delivered by the charged particle increases sharply as the particle approaches the end of its range, a position known as the Bragg peak. The Bragg curve does not necessarily represent the biological damage along the particle traversal, and the 'biological Bragg curve' is dependent on the energy and the type of the primary particle, and may vary for different biological endpoints. Here we used a unique irradiation geometry to measure the biological response across the Bragg curve in human fibroblasts exposed to ...

2006-10-15

374

Thermokinetic investigation of effects of carbon source on petroleum bacterial growth  

Energy Technology Data Exchange (ETDEWEB)

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 ...

2002-02-07

375

The mass dependence of the signal peak height of a Bragg-curve ionization chamber  

International Nuclear Information System (INIS)

The Bragg-curve detector of the parallel plate ionization chamber type generates a signal that is a distorted replica of the original Bragg-curve. In result of this distortion, the signal peak height is not only a function of the atomic number of the heavy ion, as it is often stated, but also of the particle mass. This mass effect was studied with the aid of computer simulation, and it was found to be dependent on the Frisch grid to anode gap width and on the detector gas. The charge resolution of the detector is affected very significantly by this mass dependence of the signal peak height. Therefore, a careful selection of the detector gas and the grid to anode gap width is necessary, if good charge resolution over a wide range of heavy ions is required. (orig.).

376

Plasma density measurement of electron cyclotron resonance ion source for neutron generator  

International Nuclear Information System (INIS)

It is a traditional method to diagnose electron-cyclotron-resonance (ECR) plasma source, using a single probe to measure the current-voltage curve of the plasma, based on which and theoretic formula the plasma density can be computed. The article adopts a Langmuir probe having a role of emission electrons to measure two different current-voltage curves with and without emission. It is ease to get the plasma potential via the inflexion of the two curves and compute directly various physical quantities by the assistant computer, such as electron temperature, electron/ion density, plasma potential etc. The deviation is about percent 1.8 between the measurement results by traditional and the new method, but the latter has higher efficiency. (authors)

2007-12-01

377

Particle identification for heavy ions in a time-of-flight spectrometer  

Energy Technology Data Exchange (ETDEWEB)

A time-of-flight (TOF) spectrometer has been constructed at the JAERI 20 MV tandem accelerator facility. A position-sensitive start detector, which consists of a thin carbon foil, microchannel plates and a resistive plate, was developed for the TOF measurements through the spectrometer. The time and position resolutions obtained were 120 ps and 0.3 mm for ..cap alpha.. particles from /sup 241/Am, respectively. A two-dimensional position-sensitive detector was also developed to measure the solid angle of the spectrometer and the maximum solid angle obtained was 9.5 msr. As a particle detector a Bragg curve ionization chamber was developed. From the Bragg curves of heavy ions in the detector, energies, ranges and Bragg curve peaks were measured and used for particle identification. The resolving power Z/..delta..Z of the atomic number was about 50.

1982-05-01

378

Optimum aspect ratio for heat transfer enhancement in curved rectangular channels  

Science.gov (United States)

Enhanced heat transfer in curved rectangular channels depends on at least two geometric factors, the radius of curvature of the duct and the aspect ratio, which is the width/depth ratio of the duct. In this work, an expression for optimum aspect ratio is derived mathematically from a correlation that includes both aspect ratio and bend curvature parameters. Enhancement factors are developed that show optimal, near-optimal, and nonoptimal aspect ratios for curved rectangular ducts. Predicted enhancements are within 25% of published literature results for individual designs, two of which show heat transfer enhancement of 200% over that of a straight duct with turbulent flow. The theoretical maximum enhancement is shown to be about 480% over a straight-duct, turbulent-flow situation. This is not achievable in practice, but near-optimal solutions are achievable, yielding enhancements on the order of 200--300%.

379

On the anatomy of the adsorption heat versus loading as a function of temperature and adsorbate for a graphitic surface  

British Library Electronic Table of Contents (United Kingdom)

In this paper we review and classify the various patterns of isosteric heat versus loading for adsorption of gases on graphitised thermal carbon black at temperatures ranging from below the 3D triple point to temperatures above it, but less than the 3D critical point. We have identified the features of heat curve and highlighted the microscopic origin of these features. The patterns vary with temperature and with the relative strength of the fluid-fluid interaction and solid-fluid interaction. For simple adsorptives (by simple we meant there is no strong association between fluid particles), the heat curve is typified by fluid-fluid attraction and layering phenomena. For adsorptives showing strong association such as water, ammonia and methanol, the heat curve essentially begins below the ...

2008-01-01

380

Mass dependence of the signal peak height of a Bragg-curve ionization chamber  

Energy Technology Data Exchange (ETDEWEB)

The Bragg-curve detector of the parallel plate ionization chamber type generates a signal that is a distorted replica of the original Bragg-curve. In result of this distortion, the signal peak height is not only a function of the atomic number of the heavy ion, as it is often stated, but also of the particle mass. This mass effect was studied with the aid of computer simulation, and it was found to be dependent on the Frisch grid to anode gap width and on the detector gas. The charge resolution of the detector is affected very significantly by this mass dependence of the signal peak height. Therefore, a careful selection of the detector gas and the grid to anode gap width is necessary, if good charge resolution over a wide range of heavy ions is required.

1985-01-01

381

Mapping of local cerebral blood flow with stable xenon-enhanced CT and the curve-fitting method of analysis  

Energy Technology Data Exchange (ETDEWEB)

A noninvasive method is described for estimating local cerebral blood flow (LCBF) and local partition coefficients by means of computed tomographic scanning during inhalation of 30% stable xenon gas in oxygen. Time-dependent xenon concentrations in arterial blood and brain tissue during the wash-in and washout phases are used to calculate partition coefficients and LCBF values by means of a least-squares curve-fitting analysis. Control values for partition coefficient and LCBF obtained from control subjects with minor head trauma in the chronic stage were compatible with those in several past reports, and reproducibility was satisfactory. The theoretic grounds underlying this new method of curve-fitting analysis are discussed.

1988-07-01

382

Mapping of local cerebral blood flow with stable xenon-enhanced CT and the curve-fitting method of analysis  

International Nuclear Information System (INIS)

A noninvasive method is described for estimating local cerebral blood flow (LCBF) and local partition coefficients by means of computed tomographic scanning during inhalation of 30% stable xenon gas in oxygen. Time-dependent xenon concentrations in arterial blood and brain tissue during the wash-in and washout phases are used to calculate partition coefficients and LCBF values by means of a least-squares curve-fitting analysis. Control values for partition coefficient and LCBF obtained from control subjects with minor head trauma in the chronic stage were compatible with those in several past reports, and reproducibility was satisfactory. The theoretic grounds underlying this new method of curve-fitting analysis are discussed.

383

Internal friction of amorphous Pd/sub 80/ Si/sub 20/ metal doped with hydrogen isotopes  

Energy Technology Data Exchange (ETDEWEB)

Internal friction of amorphous Pd/sub 80/Si/sub 20/ metal doped with hydrogen or deuterium was measured with a specially designed apparatus using amorphous metal sheet as a part of the electric oscillating circuit. Two peaks in Q/sup -1/ curve are observed. Applying the peak shift method to the first Snoek-like peak, we can determine the relaxation time from which the microdiffusion coefficient can be calculated. The obtained microdiffusion coefficient is about 10/sup -14/ m/sup 2//s at 200 K, being comparable with the macrodiffusion coefficient obtained from the releasing method. It can, however, not elucidate the hydrogen isotopic effect on the peak temperature of Q/sup -1/ curve, the activation energy for relaxation and the relaxation time from the present work because of the broadness of obtained Q/sup -1/ curve.

1983-02-01

384

Focused ion beam sculpting curved shapes.  

Energy Technology Data Exchange (ETDEWEB)

A focused ion beam (FIB) is used to accurately sculpt predetermined micron-scale, curved shapes in a number of solids. Using a digitally scanned ion beam system, various features are sputtered including hemispheres and sine waves having dimensions from 1-50 {micro}m. Ion sculpting is accomplished by changing pixel dwell time within individual boustrophedonic scans. The pixel dwell times used to sculpt a given shape are determined prior to milling and account for the material-specific, angle-dependent sputter yield, Y({theta}), as well as the amount of beam overlap in adjacent pixels. A number of target materials, including C, Au and Si, are accurately sculpted using this method. For several target materials, the curved feature shape closely matches the intended shape with milled feature depths within 5% of intended values.

2005-02-01

385

Effect of mass transport on the determination of corrosion rates from polarization measurements  

Energy Technology Data Exchange (ETDEWEB)

Many methods have been proposed for the determination of the corrosion current density from polarization curves; the two most commonly used ones are the three-point method and the curve-fitting method. The basis of these methods is a polarization equation that was derived for the complete absence of mass-transport effect or considers the cathodic partial reaction to be under complete mass-transport control. The mixed-control case has been much less investigated, even though this case may quite frequently reflect practical situations. A completely generalized polarization equation is proposed that can be used as a basis for curve-fitting data evaluation under any conditions. This equation was used to determine the error caused by the neglect of mass-transport effect in conventional data evaluation.

1986-10-01

386

Atmospheric emissions and economic growth. Environmental Kuznets Curve and Kyoto protocol; Emisiones atmosfericas y crecimiento economico en Espana. La Curve de Kuznets ambiental y el protocolo de Kyoto  

Energy Technology Data Exchange (ETDEWEB)

From the beginning of the 90s the analysis of the relationships between economic growth and environmental pressures has been influenced by the Environmental Kuznets Curve hypothesis or inverted-U shaped relationship between environmental pressure and per capita income. Following this hypothesis, once achieved certain income level, more economic growth is followed by environmental quality improvement. In this paper, we analyse and discuss the theories that support this hypothesis as well as the empirical evidence on this subject. Further on we analyse the relationship between per capita income and the main environmental pollutants for the case does not support the hypothesis. The empirical evidence shows that economic growth, by itself, does not entail a pollution reduction. (Author) 35 refs.

2004-07-01

387

Advanced distillation curve measurements for corrosive fluids: Application to two crude oils  

British Library Electronic Table of Contents (United Kingdom)

We have recently introduced several important improvements in the measurement of distillation curves for complex fluids. The modifications include a composition-explicit data channel for each distillate fraction (for both qualitative and quantitative analysis) and corrosivity assessment of each distillate fraction. The composition-explicit information is achieved with a new sampling approach that allows precise qualitative as well as quantitative analyses of each fraction, on the fly. We have applied the new method to a variety of fluids, including simple n-alkanes, rocket propellant, gasoline, jet fuels, and a hydrocarbon fluid made corrosive with dissolved hydrogen sulfide. In the current contribution, we present the application of the advanced distillation curve method to two samples of...

2008-01-01

388

A large solid angle, high stopping power Bragg curve spectrometer for coincidence measurements  

Energy Technology Data Exchange (ETDEWEB)

A large acceptance, high stopping power, Bragg curve spectrometer has been developed for use in coincidence experiments with heavy ions. The electron collection fields are radial and position information is obtained from a resistive anode. The detector is 60 cm deep and operates at pressures of up to 2.5 atm of P-10 gas. It is mated to a scattering chamber which allows it to be moved out of plane during coincidence measurements. The detector design was aided by the results of computer simulations of the electron collection process in the detector, and of the signal processing in the electronics. The signals from the Bragg curve spectrometer are recorded in a waveform digitizer and the Bragg peak height, range, position and pileup rejection information are determined from software analysis of the recorded signals. Factors limiting the performance of the detector are discussed, and results obtained with the detector are presented. (orig.).

1991-09-01

389

A large solid angle, high stopping power Bragg curve spectrometer for coincidence measurements  

International Nuclear Information System (INIS)

A large acceptance, high stopping power, Bragg curve spectrometer has been developed for use in coincidence experiments with heavy ions. The electron collection fields are radial and position information is obtained from a resistive anode. The detector is 60 cm deep and operates at pressures of up to 2.5 atm of P-10 gas. It is mated to a scattering chamber which allows it to be moved out of plane during coincidence measurements. The detector design was aided by the results of computer simulations of the electron collection process in the detector, and of the signal processing in the electronics. The signals from the Bragg curve spectrometer are recorded in a waveform digitizer and the Bragg peak height, range, position and pileup rejection information are determined from software analysis of the recorded signals. Factors limiting the performance of the detector are discussed, and results obtained with the detector are presented. (orig.).

390

i " GeorgeC. Marshall Space Flight Center _i. Marshall SpaceFlight ...  

Science.gov (United States)

learning curve values as observed from data taken to plot a trend .... Log QF = Log F1 + Log F2 + Log F3 + Log F4 ffi 2.98227 . ...

391

Selected results in hadron structure from lattice QCD  

Energy Technology Data Exchange (ETDEWEB)

I present results for the mass spectrum of excited baryons and pentaquarks using overlap fermions and Bayesian curve-fitting method; and magnetic moments and polarizabilities for a variety of hadrons in the background field method.

2006-03-15

392

Selected results in hadron structure from lattice QCD  

International Nuclear Information System (INIS)

I present results for the mass spectrum of excited baryons and pentaquarks using overlap fermions and Bayesian curve-fitting method; and magnetic moments and polarizabilities for a variety of hadrons in the background field method.

2006-03-01

393

STUDY OF SYSTEMS AND COST/PERFORMANCE METHODOLOGIES FOR ...  

Science.gov (United States)

of first unit and learning curve (LC) factor for hardware, ETR, and WTR recurring cost respectively. ...... 105 FORMAT (12,A6,F4.2,6X.F7 0,F6 OF7 0.12. 2012) ...

394

SN1987A: The supernova of a lifetime  

Energy Technology Data Exchange (ETDEWEB)

The current status of cosmological observations is presented; and the light curves and radiation spectra from supernova SN1987A are used in comparison between expected and observed universal nucleosynthesis and star evolution data./aip/.

1988-09-20

395

Research in heavy-ion nuclear physics  

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.

1992-01-01

396

RENDEZVOUS AND DOCKING - NASA Technical Report Server (NTRS)  

Science.gov (United States)

An indicator of when the learning curve reaches a standard is when fuel consumption remains relatively ...... f4 7'tI. 1.i7J43t. F ,oo,. , F17i [ !i ...

397

Noncooperativity of the ?? Dimer in the Reaction of Hemoglobin with Oxygen  

UK PubMed Central (United Kingdom)

The theory that the αβ dimer is the functional unit of cooperativity in hemoglobin has been tested by determination of the oxygen equilibrium curve of stable deoxy dimers, obtained by...Full Text Available

1972-01-01

398

Measurement of local cerebral blood flow by computerized tomography with inhalation of stable xenon and curve-fitting method  

Energy Technology Data Exchange (ETDEWEB)

Non-invasive methods are described for estimating local cerebal blood flows (LCBF) and local partition coefficients (Llambda) during inhalation of 30 % stable xenon gas (Xe) in oxygen during CT scanning. After the denitrogenation with pure oxygen breathing, 30 % Xe is inhaled for four minutes to minimize subanesthetic effects with a rubber facemask and the delivery system of Xe. Local time-..delta.. Hounsfield units curve during the Xe wash-in and wash-out phase is utilized in order to calculate Llambda and LCBF using a least squares curve fitting analysis. Calculated Llambda and LCBF with the new method manifested reasonable distribution between the grey and white matters, and reproducibility was excellent in our study. Several case studies of patients with cerebral infarction are presented to demonstrate the characterization of Llambda and LCBF patterns in various tissues and theoretical grounds underlying the new method of ...

1988-07-01

399

Measurement of local cerebral blood flow by computerized tomography with inhalation of stable xenon and curve-fitting method  

International Nuclear Information System (INIS)

Non-invasive methods are described for estimating local cerebal blood flows (LCBF) and local partition coefficients (L#lambda#) during inhalation of 30 % stable xenon gas (Xe) in oxygen during CT scanning. After the denitrogenation with pure oxygen breathing, 30 % Xe is inhaled for four minutes to minimize subanesthetic effects with a rubber facemask and the delivery system of Xe. Local time-#DELTA# Hounsfield units curve during the Xe wash-in and wash-out phase is utilized in order to calculate L#lambda# and LCBF using a least squares curve fitting analysis. Calculated L#lambda# and LCBF with the new method manifested reasonable distribution between the grey and white matters, and reproducibility was excellent in our study. Several case studies of patients with cerebral infarction are presented to demonstrate the characterization of L#lambda# and LCBF patterns in various tissues and theoretical grounds underlying the new method of ...

401

MAGIC - Multi Anode Gas Ionization Chamber  

Energy Technology Data Exchange (ETDEWEB)

A novel approach to the Bragg curve spectroscopy is utilized to construct a charged particle detector which makes fragment elemental identification and energy measurement possible. The advantage of the construction includes good timing and spectroscopic properties with a very low energy threshold. ((orig.))

1994-12-01

402

Intelligent Motion and Interaction Within Virtual Environments  

Science.gov (United States)

Typical aircraft types supported include F4-Phantom, Tornado, MiG-29 ...... attempt to develop a theoretical explanation for learning phenomena [16]. ..... perspective, a primary reason for this is that an exponential curve approximates ...

403

First body fat percentiles for 607 children from Thessaloniki-Northern Greece  

UK PubMed Central (United Kingdom)

Background and Aim: The purpose of this study was to establish for the first time reference curves for body fat levels in a Greek pediatric population aged 7-15y.Methods:...Full Text Available

2010-07-01

404

Evaluation of femoral head perfusion by dynamic MRI  

International Nuclear Information System (INIS)

The purpose of this study was to evaluate the usefulness of dynamic MRI for femoral head perfusion. Objects were 64 femoral heads of 44 normal cases (20-95 years old), 10 cases (33-90 y) of femoral neck fracture and 8 cases (61-86 y) using steroid due to articular rheumatism, nephrosis and other diseases. Siemens 1.0 T Magneton Impact with body array coil was used for dynamic MRI by the fast low-angle shot 2D method for every 17 sec interval. Gd-DTPA was injected intravenously. ROI was defined in the center of femur head and of trochanter to monitor their values for the dynamic curve. Evaluation was done on the ratio of enhancement ratio (ER) in the head/trochanter and on the curve in both heads. In normal cases, the head ER was significantly lower in >60 years old cases. There was neither significant correlation between their head/trochanter ER ratios nor significant difference between their dynamic curves. In fracture ...

1998-05-01

405

Effects of Daily Morphine Administration and Deprivation on Choice and Demand for Remifentanil and Cocaine in Rhesus Monkeys  

UK PubMed Central (United Kingdom)

Choice procedures have indicated that the relative reinforcing effectiveness of opioid drugs increases during opioid withdrawal. The demand curve, an absolute measure of reinforcer value, has not been...Full Text Available

2011-01-01

406

Developments of heavy-ion gas detectors at LNL  

Energy Technology Data Exchange (ETDEWEB)

The most important developments in gaseous detectors at LNL are reviewed. Some aspects of timing, pulse height and position resolutions of avalanche counters are reported. The experimental work on heavy-ion identification by Bragg curve spectroscopy is summarized.

1984-05-01

407

Development of highly reliable screening by using x-ray fluorescence spectrometry. Applications to determine lead in tin plated and tin-bismuth plated samples  

International Nuclear Information System (INIS)

A highly reliable screening method was developed for the determination of lead in tin plated layers and tin-bismuth plated layers. The contents of lead in the layers of the various samples were determined by inductively coupled plasma optical emission spectrometry. The calibration curve for lead in the tin and tin-bismuth plated layers by using WD-XRF exhibited linear correlation from 130 #mu#g/g to 2070 #mu#g/g. Calibration curve of lead normalized with Pb-L#alpha#/Sn-K#alpha# intensity was more linear, and this method was possible to evaluate very small sample. The calibration curve for lead in the tin plated layers by using ED-XRF was good linearly, but it for lead in the tin-bismuth plated layers was affected by Pb-L#alpha# spectrum and Bi-L#alpha# spectrum overlap each other. It was effective for decreasing affect of Bi-L#alpha# spectrum by using curve fitting method. (author)

2009-03-01

408

Computational Analysis of Dynamic SPK(S8)-JP-8 Fueled ...  

Science.gov (United States)

the Advanced Distillation Curve, Energy & Fuels, Vol. 22, No. 2, pp. 11041114. http://pubs.acs.org/doi/full/10.1021/ef700562c. Lemmon, E. W., Huber, M. L., ...

409

Comparative experimental study of dual energy subtraction and conventional digital radiography on chest  

International Nuclear Information System (INIS)

Objective: To compare the efficiency of dual energy subtraction and conventional direct digital radiography in signal detecting ability. Methods: 200 plastic balls which were 4 mm in diameter were taken as signals and were placed on a 10 cm thick plastic board and the right upper thorax of a healthy volunteer. The signals were examined by DES and CDR separately and were estimated by 3 radiologists with 5-value-differentiation method. ROC curve analysis was made by ROC kit software. Results: when signals on plastic board were detected by CDR and DES, ROC curve analysis indicated that there was no significant difference (P=0.4851 > 0.05, two-tailed) between the area under the ROC curves of the two methods (Az=0.9931 for CDR and Az=0.9879 for DES). The difference was significant (P=0.0002 <0.01, two-tailed) between the area under the ROC curves of CDR and DES (Az=0.7276 for CDR and Az=0.8561 for ...

2005-06-01

410

Cargo Projects Milestones, Schedules and Status Summary  

Science.gov (United States)

subject to a learning curve which should help to lessen the user's time at KSC. An MMSE Payload Handling Fixture has ...... (F4.I ASSlUN IASILlM.ny.CTC I ...

411

Average output lasing power of a He-Ne laser as a function of the modulation frequency of resonator losses  

Science.gov (United States)

The frequency dependence of the lasing power of a He-Ne laser was studied using the electrooptic effect in a KDP crystal. The gain profile of the power curve was found to differ noticeably between the high-frequency and low-frequency edges. (AIP). (AIP)

1976-09-01

412

- 1 AND MIqlTORING OF RESOURCES - NASA Technical Report Server (NTRS)  

Science.gov (United States)

SEG DAVO'24,(F4). 74. IN LARSYS DAVD'i? 75. SE( DAVD 13., (Ft). 76. INl LARSYS jAV) 13 ...... The main premise of the learning curve, or the manufac ...

413

Thermally developing flow in curved square ducts with internal fins  

Energy Technology Data Exchange (ETDEWEB)

The laminar incompressible hydrodynamically fully developed and thermally developing flow is studied in a curved square duct with four longitudinal fins. The duct is successively subjected to constant wall temperature, to circumferentially uniform temperature and axially linearly or exponentially varying temperature. The local and fully developed Nusselt numbers are examined for various values of the Dean number and it is found that the heat transfer rate increases for high fins. The parameters that affect the entry length are studied and the fluctuations of the local Nu that appear in the entrance region are investigated. Temperature contour plots are presented for the visualization of the temperature field and functional relations for the Nusselt number are proposed in terms of the Dean and Prandtl numbers. (orig.)

2005-11-01

414

Theoretical magnon dispersion curves for Gd  

International Nuclear Information System (INIS)

The magnon dispersion curve of Gd metal has been determined from first principles by use of augmented-plane-wave energy bands and wave functions. The exchange matrix elements I (k,k') between the 4f electrons and the conduction electrons from the first six energy bands were calculated under the assumption of an unscreened Coulomb interaction. The results are in good overall agreement with experiment provided the I (k,k') are diminished by a constant scale factor of about 2 which may be caused by screening.

415

The circadian rhythm for the number and sensitivity of radiation-induced apoptosis in the crypts of mouse small intestine  

Energy Technology Data Exchange (ETDEWEB)

Survival curves were constructed from dose-incidence curves for apoptosis in the crypts of mouse small intestine, using the number of apoptotic cells after high doses (N{sub M}) as maximum cell population size. The mean lethal doses (D{sub 0}) for the dose range 0-0.5 Gy were calculated for each time of day. A circadian rhythm in both D{sub 0} and N{sub M} values was detected, indicating that both the number and sensitivity of radiation-induced apoptosis were changing throughout the day. (author).

1990-07-01

416

T-duality, space-time spinors and R-R fields in curved backgrounds  

Energy Technology Data Exchange (ETDEWEB)

We obtain the T-duality transformations of space-time spinors (the supersymmetry transformation parameters, gravitinos and dilatinos) of type-II theories in curved backgrounds with an isometry. The transformation of the spinor index is shown to be a consequence of the twist that T-duality introduces between the left- and right-moving local Lorentz frames. The result is then used to derive the T-duality action on Ramond-Ramond field strengths and potentials in a simple way. We also discuss the massive IIA theory and, using duality, give a short derivation of 'mass'-dependent terms in the Wess-Zumino actions on the D-brane world-volumes.

2000-02-28

417

Study of total ionizing dose radiation effects on nitride/oxide stack gate MOS capacitor  

International Nuclear Information System (INIS)

The aim of this paper is to investigate the total ionizing dose (TID) radiation effects on MOS capacitor with nitride/oxide stack gate. The stack gate MOS capacitors are fabricated with 20 nm oxide, 40 nm nitride or 110 nm nitride respectively. Through the analysis of CV curve of the irradiation capacitors, it is found that the degradation of the CV curve is due to a significant increase of interface traps and somewhat smaller oxide charge. It is also shown that the thicker of the nitride, more interface traps and oxide charge will be occurred. (authors)

2008-07-01

418

Shielded and unshielded geometries in the search for orphan sources  

Energy Technology Data Exchange (ETDEWEB)

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.

2006-05-15

419

Shielded and unshielded geometries in the search for orphan sources  

International Nuclear Information System (INIS)

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.

2006-05-01

420

Results from a Bragg Curve Spectrometer  

Energy Technology Data Exchange (ETDEWEB)

The Bragg Curve Spectrometer (BCS) is an ionization chamber long enough to stop particles of interest. Particles enter through the cathode window and leave an ionization track parallel to the electric field. The ionization electrons drift through a Frisch grid and are collected on an anode. The anode current, as a function of time, is split and used as input for two amplifiers, one with a long integration time constant for energy measurement, and one with a short time constant to pick off the maximum ionization or Bragg peak. The Bragg peak, which is proportional to the nuclear charge, is used for particle identification. We have constructed and tested several versions of the BCS. The results are described.

1984-01-01

421

Results from a Bragg Curve Spectrometer  

International Nuclear Information System (INIS)

The Bragg Curve Spectrometer (BCS) is an ionization chamber long enough to stop particles of interest. Particles enter through the cathode window and leave an ionization track parallel to the electric field. The ionization electrons drift through a Frisch grid and are collected on an anode. The anode current, as a function of time, is split and used as input for two amplifiers, one with a long integration time constant for energy measurement, and one with a short time constant to pick off the maximum ionization or Bragg peak. The Bragg peak, which is proportional to the nuclear charge, is used for particle identification. We have constructed and tested several versions of the BCS. The results are described.

1984-10-22

422

Practical measurement of diffusion constants in sintered zirconias by using a light-scattering method  

Energy Technology Data Exchange (ETDEWEB)

A practical method to determine the ionic diffusion coefficient and activation energy by using quasielastic light scattering (QELS) is presented. It is shown that a temperature dependence curve of the QELS intensity at a fixed frequency can be well fitted by Jonscher's formula and that the diffusion parameters can be obtained from this curve fitting. This method is successfully applied not only to crystals with high optical quality, as reported earlier, but also to opaque ceramics, which are more important than the crystals from a practical point of view. The composition dependence of the ionic diffusion coefficient is studied in sintered YbSZ to show the usefulness of this method.

1991-03-01

423

Phenomenological study of light-induced effects in #alpha#-Al_2O_3:C  

International Nuclear Information System (INIS)

A computerised glow curve deconvolution (CGCD) analysis was applied to the main dosimetric peak of #alpha#-Al_2O_3:C in order to study the effects of light on the glow curve shape. It was shown that both the light-induced signal and the light-induced fading effects tend to shift the main dosimetric peak to higher temperatures and at the same time change its shape. Furthermore it was confirmed that the magnitude of the light-induced signal depends on radiation history and, by increasing the duration of light exposure, the magnitude of the light-induced signal reaches a plateau, thereby implying the saturation of the phototransfer process. (author).

1995-07-10

424

On the Generic vanishing of certain Koszul cohomology groups  

CERN Document Server

We propose a new approach to study Koszul cohomology of general $g^r_d$'s on general curves via degenerations and deformations. As an application of this new method, we prove projective normality for general line bundles $L$ on general curves with $h^1(L)\\le1$ and degree greater than roughly $(5/4)g$. This improves the bound in a classical theorem of Green and Lazarsfeld. Also we give some partial results on vanishing of higher syzygies for line bundles with $h^1(L)=1$.

2011-01-01

425

Man-made disasters: A cross-national analysis  

British Library Electronic Table of Contents (United Kingdom)

This research investigates the impact of national culture and several institutional factors on the safety performance of society and establishes statistically significant relationships between those variables. As expected, the research results reveal that some cultural variables such as uncertainty avoidance, gender orientation and institutional variables such as the degree of law avoidance can directly influence the safety performance of the society. The findings also support the inverted u-curve (Safety Kuznet curve) hypothesis indicating even if we expect a negative trend at the beginning stage of industrialization, we can expect a positive trend in safety performance as their income level continues to improve beyond a certain point.

2011-01-01

426

Large solid angle Bragg-curve spectrometer  

Energy Technology Data Exchange (ETDEWEB)

A conical Bragg-curve spectrometer (BCS) has been constructed. The outer case was a molded plastic cone. Printed circuit techniques were used to form an insert with inscribed equipotentials to approximate a 1/r/sup 2/ electric field shape. The charge and energy resolution were measured for elastically scattered beams of 206 MeV /sup 28/Si, 413 and 378 MeV /sup 56/Fe, and 670 MeV /sup 86/Kr ions. Performance of this detector, particularly its charge resolution, is discussed with respect to variation in solid angle.

1984-02-01

427

High Resolution Eddy Current Probes for Non Destructive Testing  

Science.gov (United States)

New industrial Non Destructive Testing requires the development of new probes: technologies such as high spatial resolution probes for small breaking flaws detection or flexible probes for complex curved surfaces inspection. The CEA/LIST has designed and integrated 2 probes to answer industrial's constraints. The first one is based on Giant Magneto-Resistance and is able to detect 50 ?m3 flaws. The second one is based on micro-coils etched on kapton and its flexibility is adapted to curved surfaces inspection. Both are multi-elements probes, allowing fast inspection. This paper presents those new probes, their design and their performances.

2008-02-01

428

Findings of long-term SO/sub 2/ measurements in Stuttgart  

Energy Technology Data Exchange (ETDEWEB)

SO/sub 2/ concentrations in the Stuttgart air have been measured continuously since 1965. The two measuring points were located at the bottom of the Stuttgart city basin and 900 m east on the side of one of the surrounding hills. Long-term curves of pollutant loads have been established in consideration of meteorological parameters, as well as curves showing the average daily, weekly, and yearly pollution. The information thus gained may help to plan air pollution abatement measures in city planning.

1982-02-01

429

Effect of the size of an artificial neural network used as pattern identifier  

Energy Technology Data Exchange (ETDEWEB)

A novel way to extract relevant parameters associated with the outgoing ions from nuclear reactions, obtained by digitizing the signals provided by a Bragg curve spectrometer (BCS) is presented. This allowed the implementation of a more thorough pulse-shape analysis. Due to the complexity of this task, it was required to take advantage of new and more powerful computational paradigms. This was fulfilled using a back-propagation artificial neural network (ANN) as a pattern identifier. Over training of ANNs is a common problem during the training stage. In the performance of the ANN there is a compromise between its size and the size of the training set. Here, this effect will be illustrated in relation to the problem of Bragg Curve (BC) identification. (Author)

2003-07-01

430

Determination methods of alpha activity ratio  

International Nuclear Information System (INIS)

The three determination methods of alpha activity ration are described, namely geometric progression method, extrapolation method and curve fitting method. The validity of the geometric progression method is demonstrated in the present work. The "2"3"8Pu/("2"3"9Pu + "2"4"0Pu) evaluated by extrapolation method is compared with that by geometric progression method. Also, the "2"3"8Pu/("2"3"9Pu + "2"4"0Pu)evaluated by curve fitting method is compared with that by geometric progression.

431

Application of the digital waveform analysis to Bragg curve spectrometer  

International Nuclear Information System (INIS)

Energy and angular double-differential cross-section (DDX) data of fragment production reactions by neutrons or protons are very scarce due to experimental difficulties of fragment detection. We adopted a Bragg curve spectrometer (BCS), which is a gridded-ionization chamber that can identify fragments on the basis of the Bragg peak value. We have been developing the BCS for neutron and proton-induced reactions applying the digital waveform analysis technique to obtain better ability of particle discrimination than the analog electronic circuit. (T. Tanaka)

2004-11-01

432

A high stopping power, large acceptance Bragg curve spectrometer for heavy ion detection  

Energy Technology Data Exchange (ETDEWEB)

A large acceptance, high stopping power Bragg curve spectrometer has been developed for use in coincidence experiments with heavy ions. The electron collection fields are radial and position information is obtained from a resistive anode. The detector is 60 cm deep and operates at pressures of up to 2.5 atm of P-10 gas. It is mated to a scattering chamber which allows it to be moved out of plane during coincidence measurements. Factors affecting the performance of the detector are discussed, and results obtained with the detector are presented. (orig.).

1991-05-01

433

A high stopping power, large acceptance Bragg curve spectrometer for heavy ion detection  

International Nuclear Information System (INIS)

A large acceptance, high stopping power Bragg curve spectrometer has been developed for use in coincidence experiments with heavy ions. The electron collection fields are radial and position information is obtained from a resistive anode. The detector is 60 cm deep and operates at pressures of up to 2.5 atm of P-10 gas. It is mated to a scattering chamber which allows it to be moved out of plane during coincidence measurements. Factors affecting the performance of the detector are discussed, and results obtained with the detector are presented. (orig.).

434

GHG emissions, GDP growth and the Kyoto Protocol: A revisit of Environmental Kuznets Curve hypothesis  

Energy Technology Data Exchange (ETDEWEB)

The Kyoto Protocol attempts through political negotiations to guide participating industrialized countries' greenhouse gas (GHG) emissions from a positive growing trend, to reach a peak point (or turning point), and then be reduced to a negative growth. That means the relationship between decreasing GHG emissions and economic growth may be described by an inverted-U curve (or called a bell-shaped curve), which is consistent with the concept of the Environmental Kuznets Curve (EKC) hypothesis. This research observed that the economic development and GHG emissions in Economies in Transition (EITs) exhibit a hockey-stick curve trend (or called quasi-L-shape curve), that also generates a lot of 'hot air' which is significant to the implementation of the Kyoto Protocol. In addition, through the analysis of single-country time series data and GDP data, this ...

2008-01-15

435

GHG emissions, GDP growth and the Kyoto Protocol: A revisit of Environmental Kuznets Curve hypothesis  

Energy Technology Data Exchange (ETDEWEB)

The Kyoto Protocol attempts through political negotiations to guide participating industrialized countries' greenhouse gas (GHG) emissions from a positive growing trend, to reach a peak point (or turning point), and then be reduced to a negative growth. That means the relationship between decreasing GHG emissions and economic growth may be described by an inverted-U curve (or called a bell-shaped curve), which is consistent with the concept of the Environmental Kuznets Curve (EKC) hypothesis. This research observed that the economic development and GHG emissions in Economies in Transition (EITs) exhibit a hockey-stick curve trend (or called quasi-L-shape curve), that also generates a lot of 'hot air' which is significant to the implementation of the Kyoto Protocol. In addition, through the analysis of single-country time series data and GDP data, this ...

2008-01-15

436

The Protective Effect of Antioxidants on Oxidative Stress in Rats Exposed to the 950 MHz Electromagnetic Field  

International Nuclear Information System (INIS)

Studies have linked cell phone radiation to health problems such as headaches, high blood pressure, cancer and more. There is a latency period for most diseases and it may take years and more studies before the required weight of evidence is established. But the effects are cumulative and precautions should be taken now before it is too late. The aim of the present study was to investigate if supplementation with antioxidants would protect heart and liver tissues from harmful radiation emitted by cell phone. Thirty two male albino rats were randomly divided into four equal groups: I- Control, II- Antioxidants treated group, III- 950 MHz EMR, IV- 950 MHz EMR + antioxidants. A 950 MHz EMR radiation (217-Hz pulse rate, 2-W maximum peak power, SAR Specific Absorption Rate"1.6 W/Kg) was applied to groups III and IV 60 min/day, for 30 days using an experimental exposure device. Antioxidants supplement (Vitamins A, E and C + Se) was administered to rats daily, by gavages, during the period of ...

437

Punica granatum peel extract protects against ionizing radiation-induced enteritis and leukocyte apoptosis in rats  

International Nuclear Information System (INIS)

Radiation-induced enteritis is a well-recognized sequel of therapeutic irradiation. Therefore we examined the radioprotective properties of Punica granatum peel extract (PPE) on the oxidative damage in the ileum. Rats were exposed to a single whole-body X-ray irradiation of 800 cGy. Irradiated rats were pretreated orally with saline or PPE (50 mg/kg/day) for 10 days before irradiation and the following 10 days, while control rats received saline or PPE but no irradiation. Then plasma and ileum samples were obtained. Irradiation caused a decrease in glutathione and total antioxidant capacity, which was accompanied by increases in malondialdehyde levels, myeloperoxidase activity, collagen content of the tissue with a concomitant increase 8-hydroxy-2'-deoxyguanosine (an index of oxidative DNA damage). Similarly, pro-inflammatory cytokines (TNF-?, IL-1? and IL-6) and lactate dehydrogenase were elevated in irradiated groups as compared to control. PPE treatment reversed ...

2009-07-01

438

Manganite reduction by Shewanella putrefaciens MR-4  

Energy Technology Data Exchange (ETDEWEB)

Previous studies have documented dissimilatory growth of bacteria on solid Mn{sup 4+} oxide, but Mn{sup 3+} oxides have not been previously studied; here the authors have demonstrated for the first time the bacterial reduction of manganite. Strain MR-4 of Shewanella putrefaciens was able to grow on and rapidly reduce insoluble needle-shaped crystals of synthetic manganite (MnOOH), converting them to soluble Mn{sup 2+} in the process. The rate of Mn{sup 3+} reduction was optimal at pH of 7.0 and 26 C consistent with an enzymatic reaction. In addition the rates of reduction were in proportion to the amount of manganite added, but nearly independent of the cell concentration present (e.g., cell number had only a small effect on the rate of Mn{sup 3+} reduction at early stages of growth) suggesting that surface properties were dictating the rates of metal reduction. This thesis was supported by major differences in reduction rates when Mn oxides of different surface areas were studied. ...

1998-11-01

439

Genome analysis of F. nucleatum sub spp vincentii and its comparison with the genome of F. nucleatum ATCC 25586.  

Science.gov (United States)

We present the draft genome sequence and its analysis for Fusobacterium nucleatum sub spp. vincentii (FNV), and compare that genome with F. nucleatum ATCC 25586 (FN). A total of 441 FNV open reading frames (ORFs) with no orthologs in FN have been identified. Of these, 118 ORFs have no known function and are unique to FNV, whereas 323 ORFs have functional orthologs in other organisms. In addition to the excretion of butyrate, H2S and ammonia-like FN, FNV has the additional capability to excrete lactate and aminobutyrate. Unlike FN, FNV is likely to incorporate galactopyranose, galacturonate, and sialic acid into its O-antigen. It appears to transport ferrous iron by an anaerobic ferrous transporter. Genes for eukaryotic type serine/threonine kinase and phosphatase, transpeptidase E-transglycosylase Pbp1A are found in FNV but not in FN. Unique ABC transporters, cryptic phages, and three types of restriction-modification systems have been identified in FNV. ORFs for ...

2003-06-01

440

Dose dependent transfer of [sup 203]lead to milk and tissue uptake in suckling offspring studied in rats and mice  

Energy Technology Data Exchange (ETDEWEB)

The dose-dependent transfer of [sup 203]Pb to milk and uptake in suckling rats and mice during a three-day nursing period was studied. On day 14 of lactation, the dams were administered a single intravenous dose of lead, labelled with [sup 203]Pb, in four or five doses from 0.0005 to 2.0 mg Pb/kg b.wt. There was a linear relationship between Pb levels in plasma and milk of both species. The Pb milk: plasma ratios at 24 hr after administration were 119 and 89 in mice and rats, respectively. At 72 hr the Pb milk: plasma ratio had decreased to 72 in mice and 35 in rats. The tissue levels of lead in the suckling rats and mice were also linearly correlated with lead concentration in milk at 72 hr, showing that milk could be used as an indicator of lead exposure to the suckling offspring. It is concluded that lead is transported into rat and mouse milk to a very high extent and the excretion into milk is more efficient in mice than in rats. On the other hand, rat pups ...

1993-09-01

441

Decreased duration of pentobarbital-induced narcosis in immature and adult female rats prenatally exposed to cimetidine  

Energy Technology Data Exchange (ETDEWEB)

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 ...

1986-03-01

442

Chronic treatment with polychlorinated biphenyls (PCB) during pregnancy and lactation in the rat  

International Nuclear Information System (INIS)

The gender-specific expression pattern of aromatase and 5alpha-reductases (5alpha-R) during brain development provides neurons the right amount of estradiol and DHT to induce a dimorphic organization of the structure. Polychlorinated biphenyls (PCBs) are endocrine disruptive pollutants; exposure to PCBs through placental transfer and breast-feeding may adversely affect the organizational action of sex steroid, resulting in long-term alteration of reproductive neuroendocrinology. The study was aimed at: a) evaluating the hypothalamic expression of aromatase, 5alpha-R1 and 5alpha-R2 in fetuses (GD20), infant (PN12), weaning (PN21) and young adult (PN60) male and female rats exposed to PCBs during development; b) correlating these parameters with the time of testicular descent, puberty onset, estrous cyclicity and copulatory behavior; c) evaluating possible alterations of some non reproductive behaviors (locomotion, learning and memory, depression/anxiety behavior). A reconstituted ...

2009-08-15

443

Caldicellulosiruptor obsidiansis sp. nov., an anaerobic, extremely thermophilic, cellulolytic bacterium isolated from Obsidian Pool, Yellowstone National Park  

Energy Technology Data Exchange (ETDEWEB)

A novel, obligately anaerobic, extremely thermophilic, cellulolytic bacterium, designated OB47T, was isolated from Obsidian Pool, Yellowstone National Park, WY, USA. The isolate was a non-motile, non-spore forming, Gram-positive rod approximately 2 m long by 0.2 m wide and grew at temperatures between 55-85oC with the optimum at 78oC. The pH range for growth was 6.0-8.0 with values of near 7.0 being optimal. Growth on cellobiose produced the fastest specific growth rates at 0.75 hr-1. The organism also displayed fermentative growth on glucose, maltose, arabinose, fructose, starch, lactose, mannose, sucrose, galactose, xylose, arabinogalactan, Avicel, xylan, filter paper, processed cardboard, pectin, dilute acid-pretreated switchgrass and Populus. OB47T was unable to grow on mannitol, fucose, lignin, Gelrite, acetate, glycerol, ribose, sorbital, carboxymethylcellulose and casein. Yeast extract stimulated growth and thiosulfate, sulfate, nitrate, and sulfur were not reduced. Fermentation ...

2010-02-01

444

The role of 3D Helical CT in the reconstructive treatment of maxillofacial cancers  

International Nuclear Information System (INIS)

Purpose of this work is to investigate the role of Helical CT and the usefulness of three-dimensional (3D) imaging for pre-operative planning and follow-up of reconstructive maxillofacial surgery with alloplastic material in neoplastic disease involving this region. From 1996 to 1999 eleven patients were examined with Helical CT and 3D images for planning of maxillofacial plastic and reconstructive surgery for advanced cancer of this anatomically complex region. A 3D-modulated titanium mesh (100%) or micro nets was used to rebuild the anterior surface of maxillary bone and the orbital floor. The mesh was cut to the appropriate size and shape and curved where necessary. Within the residual sinusal cavity a siliconed filling was used surmounting an acrylic prosthesis with dental arch to rebuild the palate. A rehydrated bovine pericardium was affixed and moduled on the borders in two cases only. Three-dimensionally reconstructed CT images were obtained preoperatively ...

2000-12-01

445

THE DOUBLE-DEGENERATE NUCLEUS OF THE PLANETARY NEBULA TS 01: A CLOSE BINARY EVOLUTION SHOWCASE  

International Nuclear Information System (INIS)

We present a detailed investigation of SBS 1150+599A, a close binary star hosted by the planetary nebula PN G135.9+55.9 (TS 01). The nebula, located in the Galactic halo, is the most oxygen-poor known to date and is the only one known to harbor a double degenerate core. We present XMM-Newton observations of this object, which allowed the detection of the previously invisible component of the binary core, whose existence was inferred so far only from radial velocity (RV) and photometric variations. The parameters of the binary system were deduced from a wealth of information via three independent routes using the spectral energy distribution (from the infrared to X-rays), the light and RV curves, and a detailed model atmosphere fitting of the stellar absorption features of the optical/UV component. We find that the cool component must have a mass of 0.54 #+-# 0.2 M_s_u_n, an average effective temperature, T_e_f_f, of 58,000 #+-# 3000 K, a mean ...

2010-05-01

446

Interaction of antimicrobial peptides with lipid membranes  

International Nuclear Information System (INIS)

This study aims to investigate the difference in the interaction of antimicrobial peptides with two classes of zwitterionic peptides, phosphatidylethanolamines (PE) and phosphatidylcholines (PC). Further experiments were performed on model membranes prepared from specific bacterial lipids, lipopolysaccharides (LPS) isolated from Salmonella minnesota. The structure of the lipid-peptide aqueous dispersions was studied by small-and wide-angle X-ray diffraction during heating and cooling from 5 to 85 C. The lipids and peptides were mixed at lipid-to-peptide ratios 10-10000 (POPE and POPC) or 2-50 (LPS). All experiments were performed at synchrotron soft condensed matter beamline A2 in Hasylab at Desy in Hamburg, Germany. The phases were identified and the lattice parameters were calculated. Alamethicin and melittin interact in similar ways with the lipids. Pure POPC forms only lamellar phases. POPE forms lamellar phases at low temperatures that upon heating transform ...

447

Characterization of decarburisation processes during austenitising of the rolling bearing steel 100Cr6. Part 1: Correlation between rim zone properties and carbon concentration profile; Charakterisierung von Randentkohlungsvorgaengen bei der Austenitisierung des Waelzlagerstahls 100Cr6. Teil 1: Korrelation zwischen Randschichteigenschaften und Kohlenstoff-Tiefenverlauf  

Energy Technology Data Exchange (ETDEWEB)

The influence of a decarburisation process during austenitising of the through-hardenable rolling bearing steel 100Cr6 (SAE 52100) on the rim zone properties of the martensitic through-hardened material was investigated by means of material analysis and diffusion calculations. For this purpose, two specimens were prepared under defined heat treatment conditions, and the near-surface carbon distribution was determined micro-chemically by using secondary ion mass spectrometry (SIMS). In part 1 of the present work, these concentration profiles are compared with the depth variation of the micro-hardness and with the distance curves of the residual stresses and the line broadening ({l_brace}211{r_brace} {alpha}'-Fe diffraction line) both measured by X-ray diffraction (XRD). In addition, microstructure investigations were performed. In part 2, a refined kinetics model of a diffusion-controlled reaction based on the finite element method ...

2003-08-01

448

Anthropogenic materials and products containing natural radionuclides. Pt. 2a. Investigation of occupational radiation doses. Specific and long-term measurements in a drinking-water conditioning plant; Anthropogene Stoffe und Produkte mit natuerlichen Radionukliden. T. 2a. Untersuchungen zur Strahlenexposition beim beruflichen Umgang. Detail- und Langzeitmessungen in einer Trinkwasseraufbereitungsanlage  

Energy Technology Data Exchange (ETDEWEB)

The measuring series was performed from November 1991 through April 1992 in seven drinking-water conditioning plants of the Fichtel mountains area in the north-eastern part of Bavaria, and the results revealed as an annual average a dose of about 1 - 40 WLM. The area of interest is a drinking-water catchment area where the ground water and other water resources include waters particularly rich in radon content, which explains this relatively high dose range. This is why comprehensive, specific local and long-term mearurements were carried out in order to assess the occupational radiation dose in the drinking-water conditioning plants, taking as a model site the conditioning plant of the municipal utilities of Hof in Weissenstadt. These more specific measurements were performed by the Technical Inspectorates (TUeV) of Bavaria and Saxony and the isotope laboratory of Georg-August University of Goettingen in mid-April 1994 (Goettingen University, TUeV Saxonia and ...

1995-03-01

449

Investigation of dominant loss mechanisms in low-temperature polymer electrolyte membrane fuel cells  

Energy Technology Data Exchange (ETDEWEB)

This thesis deals with the analysis of dominant loss mechanisms in direct methanol fuel cells (DMFC) and hydrogen fed polymer electrolyte membrane fuel cells (PEFC) by means of experimental characterization and modeling work. Due to different fuels used in these two fuel cell types, the dominant loss mechanisms are different in their nature. All in-situ characterization techniques that are used in this work are based on a novel test fuel cell with embedded reference electrodes. The first part of this work presents a new concept for realizing a reference electrode configuration in a polymer electrolyte membrane fuel cell by means of laser ablation. The laser beam is used to evaporate a small gap into the electrode surface of a catalyst coated membrane (CCM) to isolate the reference electrode from the working/counter electrode (WE/CE). This method enables the simultaneous ablation of the electrodes on both sides of the CCM because the membrane is transparent for the ...

2010-07-01

450

FEBEX II Project Final report on thermo-hydro-mechanical laboratory tests  

International Nuclear Information System (INIS)

The results of the thermo-hydro-mechanical (THM) study of the FEBEX bentonite performed during FEBEX II are presented. The laboratory test program continued in part with the works carried out during FEBEX I, particularly in activities related to tests aimed to the calibration of the models, the acquisition of parameters by back-analysis and the improvement of the knowledge on the behaviour of expansive clays. But the program has also included tests on new areas: investigations about the influence of the microstructure changes in bentonite, of temperature and of the solute concentration on the behaviour of clay. Besides, several tests were proposed in order to understand the unexpected behaviour observed in the mock-up test, towards the end of year 2. Temperature effects on water retention curves in confined and unconfined conditions were determined, and swelling pressure, hydraulic conductivity and swelling and consolidation strains as a ...

451

Development of a computerized portal verification scheme for pelvic treatment fields  

International Nuclear Information System (INIS)

Purpose/Objective: At present, treatment verification between portal and reference images is performed based on manually-identified features by radiation oncologist, which is both time-consuming and potentially error-prone. There is a demand for the computerized verification procedure in clinical application. The purpose of this study is to develop a computerized portal verification scheme for pelvic treatment fields. Materials/Methods: The automated verification system involves image acquisition, image feature extraction, feature matching between reference and portal images and quantitative evaluation of patient setup. Electronic portal images with a matrix size of 256 x 256 and 12 bit gray levels were acquired using a liquid matrix electronic portal imaging device. Simulation images were acquired by digitizing simulation films using a TV camera into images with 256 x 256 matrix and 8 bit gray levels. Initially a Canny edge detector is applied to identify the field edges and an ...

1996-09-01

452

SIMV: An Application of Mathematical Modeling in Ventilator Management  

UK PubMed Central (United Kingdom)

SIMV (simulation and modeling of ventilation) is a quantitative system for the mathematical modeling and simulation of pulmonary...Full Text Available

1989-11-08

457

Modeling survival in colon cancer: a methodological review  

UK PubMed Central (United Kingdom)

The Cox proportional hazards model is the most widely used model for survival analysis because of its simplicity. The fundamental assumption in this model is the proportionality of the hazard function....Full Text Available

462

A Multichannel Personal Telemetry System Using Pulse ...  

Science.gov (United States)

... Multivibrators were used in the first model, which is called the "MV Model." Mwe second model, "1ST Model," has a saw-toothed voltage. ...

1961-07-01

463

Some fundamental factors in quantitative analysis by ion microanalyzer  

International Nuclear Information System (INIS)

In analysis of hydrogen in metals and alloys by SIMS, control of the hydrogen blank mainly due to residual gases is a persistent problem. Contrarity, this problem becomes less important in case of deuterium analysis. The prescribed amounts of deuterium were introduced into a pure titanium and a beta-titanium alloy (Ti- 6.6wt%Fe) by the gas reaction method. Intensities of the various secondary ions sputtered from each sample were measured by the Hitachi Ion Microanalyzer with primary ions of Ar"+. Energy distributions of the various secondary ion species were measured with the energy window of about 15eV width. The effects of oxygen gas pressure in the target chamber and the bulk deuterium concentration on the shape of energy distribution curves are discussed. For all samples, intensity of D"- ions is higher than that of D"+ ions, especially at higher energy ranges. With increasing the deuterium concentration: a) intensities of D"+ and D"- ions from Ti-D system ...

464

Numerical ray tracing of electrons in different 3D fringing fields of spherical deflectors  

Science.gov (United States)

This paper presents the results of numerical investigations on electron trajectories in different 3D fringing fields of spherical defectors. We start with a chosen set of geometrical values for the electrodes such as radius of curvature, electrode gap, angle between entrance and exit face. We do a first numerical calculation of the spatial potential distribution using a 3D electron optics program based on the finite difference method (FDM). Ray tracing through this potential distribution is then performed using another program, which also gives the potential and the electric field strength along the curved beam path. In the next step we estimate the position and the geometry of the field clamp using Herzog's formulae assuming the entrance of a parallel plate condenser to be a good approximation for the entrance of the spherical deflector in first order. For the consecutive numerical recalculations of the real potential distribution of the spherical deflector with ...

1999-11-01

465

Genus 4 trigonal reduction of the Benney equations  

International Nuclear Information System (INIS)

It was shown by Gibbons and Tsarev (1996 Phys. Lett. A 211 19, 1999 Phys. Lett. A 258 263) that N-parameter reductions of the Benney equations correspond to particular N-parameter families of conformal maps. In recent papers (Baldwin and Gibbons 2003 J. Phys. A: Math. Gen. 36 8393-417, Baldwin and Gibbons 2004 J. Phys. A: Math. Gen. 37 5341-54), the present authors have constructed examples of such reductions where the mappings take the upper half p-plane to a polygonal slit domain in the #lambda#-plane. In those cases, the mapping function was expressed in terms of the derivatives of Kleinian #sigma# functions of hyperelliptic curves, restricted to the one-dimensional stratum #THETA#_1 of the #THETA#-divisor. This was done using an extension of the method given in Enolskii et al (2003 J. Nonlinear Sci. 13 157) extended to a genus 3 curve (Enolski V Z and Gibbons J Addition theorems on the strata of the theta divisor of genus three ...

2006-04-07

466

Voltage and reactive power control by means of static compensators of vars in electric power systems; Control de voltaje y potencia reactiva mediante compensadores estaticos de Vars en sistemas electricos de potencia  

Energy Technology Data Exchange (ETDEWEB)

In this thesis a study is made of the of voltage characteristics and reactive power control in the transmission network of the Electric Power Systems (EPS) with static compensators of VARs (SCVs). The necessity of voltage and reactive power control and the application of SCVs as a solution means for three representative operation stages of the EPS, considering balanced operation conditions and fundamental frequency is analyzed: Operation in the presence of incremental voltage changes, quasi-stationary operation or steady state and behavior at the occurrence of big disturbances. The application of SCVs to systems of integral transmission is in general a closed loop control system, reason why the analysis of the interaction of the system EPS-SCV is considered as an essential part of the voltage and reactive power control study. Firstly, the response analysis of the control loop is made for incremental voltage changes, representing the power system by means of its equivalent of Thevenin ...

1987-07-01

467

Validating eddy current array probes for inspecting steam generator tubes  

International Nuclear Information System (INIS)

A CANDU nuclear reactor was shut down for over one year because steam generator (SG) tubes had failed with outer diameter stress-corrosion cracking (ODSCC) in the U-bend section. Novel, single-pass eddy current transmit-receive probes, denoted as C3, were successful in detecting all significant cracks so that the cracked tubes could be plugged and the unit restarted. Significant numbers of tubes with SCC were removed from a SG in order to validate the results of the new probe. Results from metallurgical examinations were used to obtain probability-of-detection (POD) and sizing accuracy plots to quantify the performance of this new inspection technique. Though effective, the above approach of relying on tubes removed from a reactor is expensive, in terms of both economic and radiation-exposure costs. This led to a search for more affordable methods to validate inspection techniques and procedures. Methods are presented for calculating POD curves based on ...

1997-11-16

468

Validating eddy current array probes for inspecting steam generator tubes  

Energy Technology Data Exchange (ETDEWEB)

A CANDU nuclear reactor was shut down for over one year because steam generator (SG) tubes had failed with outer diameter stress-corrosion cracking (ODSCC) in the U-bend section. Novel, single-pass eddy current transmit-receive probes, denoted as C3, were successful in detecting all significant cracks so that the cracked tubes could be plugged and the unit restarted. Significant numbers of tubes with SCC were removed from a SG in order to validate the results of the new probe. Results from metallurgical examinations were used to obtain probability-of-detection (POD) and sizing accuracy plots to quantify the performance of this new inspection technique. Though effective, the above approach of relying on tubes removed from a reactor is expensive, in terms of both economic and radiation-exposure costs. This led to a search for more affordable methods to validate inspection techniques and procedures. Methods are presented for calculating POD curves based on ...

1997-07-01

469

Thermally stimulated currents in ZnS sandwich structure deposited by spray pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Polycrystalline ZnS semiconducting films have been prepared in sandwich configuration by spray pyrolysis technique using ZnO-coated glass substrates and mixed aqueous solutions of ZnCl{sub 2} and thiourea. The sandwich structures have been produced successfully by means of ZnO-coated glass substrates. The produced ZnS films have been crystallized in a wurtzite structure and had a direct band gap energy of 3.62 eV. The electrical properties of the sample have been studied by an analysis based on the thermally stimulated current spectra in the temperature range of 40-300 K with various heating rates. A set of curves of I (T) for varying initial density of filled traps at a heating rate of {beta} {sub 2}=0.06 K s{sup -1} indicate that the observed peaks in the TSC curve of polycrystalline ZnS films have first-order features. In order to evaluate the trap parameters of ZnS films, we have used curve-fitting method. The values of ...

2007-05-31

470

Thermal aging of cast stainless steels in LWR systems: Estimation of mechanical properties  

Energy Technology Data Exchange (ETDEWEB)

A procedure and correlations are presented for predicting Charpy-impact energy, tensile flow stress, fracture toughness J-R curve, and J{sub IC} of aged cast stainless steels from known material information. The ``saturation`` impact strength and fracture toughness of a specific cast stainless steel, i.e., the minimum value that would be achieved for the material after long-term service, is estimated from the chemical composition of the steel. Mechanical properties as a function of time and temperature of reactor service are estimated from impact energy and flow stress of the unaged material and the kinetics of embrittlement, which are also determined from chemical composition. The J{sub IC} values are determined from the estimated J-R curve and flow stress. Examples of estimating mechanical properties of cast stainless steel components during reactor service are presented. A common ``lower-bound`` J-R curve for cast ...

1991-11-01

471

Position sensitive and Bragg curve spectroscopy detector system for heavy ion reaction studies  

International Nuclear Information System (INIS)

A complete heavy ion identification system in heavy ion reaction studies consists, in general, of: 1) a position sensitive avalanche counter, and 2) ionization chamber to obtain total energy as well as a heavy ion identifier signal (such as the E#DELTA#E signal from a E-#DELTA#E type detector or the height of the Bragg peak that scales as Z of the heavy ion in a Bragg curve ionization chamber). In addition, a time-of-flight information may be needed to resolve the masses of the ions. With this motivation in mind, a composite detector system consisting of a Bragg curve spectroscopy ionization chamber (BCS-IC) and a one dimensional position sensitive parallel grid avalanche counter (XPS-PGAC) has been developed and used successfully at the BARC-TIFR pelletron accelerator facility. The design and performance of this gas detector system are reported. (author). 4 refs., 2 figs.

472

Photoconductive ultraviolet detectors based on ZnO films  

Energy Technology Data Exchange (ETDEWEB)

Properties of photoconductive ultraviolet detectors fabricated on ZnO films were presented. Highly c-axis oriented ZnO films were grown on glass substrates by pulsed laser deposition. Ultraviolet photodetectors were fabricated based on metal-semiconductor-metal planar structures. The photoresponsivity and the quantum efficiency are much higher in the ultraviolet range than in the visible range, and the peak values are around 360 nm. Photocurrent transients show that the detector has a large photocurrent with the peak value of 2.8 mA, and a slow photoresponse with a rise time of 5 min and a decay time of 7 min. The response curve of the detector is fitted well with exponential curve. The large photocurrent should result from the both effects of the accumulation of conduction electrons and the decrease of the barrier height between crystallites. The relaxation time constant {tau} obtained from the curve fitting represents the ...

2006-12-15

473

Photoconductive ultraviolet detectors based on ZnO films  

International Nuclear Information System (INIS)

Properties of photoconductive ultraviolet detectors fabricated on ZnO films were presented. Highly c-axis oriented ZnO films were grown on glass substrates by pulsed laser deposition. Ultraviolet photodetectors were fabricated based on metal-semiconductor-metal planar structures. The photoresponsivity and the quantum efficiency are much higher in the ultraviolet range than in the visible range, and the peak values are around 360 nm. Photocurrent transients show that the detector has a large photocurrent with the peak value of 2.8 mA, and a slow photoresponse with a rise time of 5 min and a decay time of 7 min. The response curve of the detector is fitted well with exponential curve. The large photocurrent should result from the both effects of the accumulation of conduction electrons and the decrease of the barrier height between crystallites. The relaxation time constant #tau# obtained from the curve fitting represents the ...

2006-12-15

474

Luminescence characteristics for the detection of radiation treatment of shellfish by using isolated minerals  

International Nuclear Information System (INIS)

Seven types of shellfish were irradiated by gamma ray at doses of 0, 3 and 6 kGy. Pulse photo-stimulated luminescence (PPSL) and thermoluminescence (TL) methods were employed to detect the radiation treatment. The screening of irradiation was carried out by the PPSL method followed by identification using the TL technique. Most of the irradiated shellfish were screened out correctly and only a few showed photon counts a bit higher than the lower threshold value by much lower than the upper threshold value. The TL method was employed using minerals isolated from all the control and irradiated shellfish samples by density gradient treatment. Three parameters, integrated intensities of first glow curves (TL1), ratios of first to that of second glow curves (TL1/TL2), and the shapes of maxima of first glow curves, were utilized for the identification of gamma ray treatment of shellfish. (author)

475

Effects of microwaves on cell survival at elevated temperatures  

Energy Technology Data Exchange (ETDEWEB)

Since microwaves are used in human cancer therapy, information on specific biological effects of microwaves at elevated temperatures is important. To help supply this information, we exposed mammalian cells (CHO) and bacteria (Serratia marcescens) to hyperthermal temperatures (43, 44, and 45/sup o/C for CHO and 48, 49, and 50/sup o/C for the bacteria) with and without microwave irradiation. Temperature control was maintained by a refrigeration-reheat system and high-velocity water recirculation. The 2450-MHz microwave source was operated in a pulsed mode with power density up to 500 mW/cm/sup 2/. As expected, the survival curve slopes for both cell types increased rapidly with temperature, doubling for each degree Celsius. Microwave irradiation produced no significant change in extrapolation number for either cell type. However, survival curves of CHO cells which received microwaves were steeper by a factor of 1.25 than their sham-irradiated ...

1981-12-01

476

Effect of Aging on the Toughness of Human Cortical Bone: Evaluation by R-Curves  

Energy Technology Data Exchange (ETDEWEB)

Age-related deterioration of the fracture properties of bone, coupled with increased life expectancy, are responsible for increasing incidence of bone fracture in the elderly, and hence, an understanding of how its fracture properties degrade with age is essential. The present study describes ex vivo fracture experiments to quantitatively assess the effect of aging on the fracture toughness properties of human cortical bone in the longitudinal direction. Because cortical bone exhibits rising crack-growth resistance with crack extension, unlike most previous studies the toughness is evaluated in terms of resistance-curve (R-curve) behavior, measured for bone taken from wide range of age groups (34-99 years). Using this approach, both the ex vivo crack-initiation and crack-growth toughness are determined and are found to deteriorate with age; the initiation toughness decreases some 40% over six decades from 40 to 100 years, while the growth ...

2004-10-08

477

Computed radiography in X-ray examination of stomach. Evaluation by phantom experiments and clinical studies  

Energy Technology Data Exchange (ETDEWEB)

The usefulness and clinical applicability of computed radiography(FCR) in X-ray examination of the stomach were evaluated in comparison with film-screen (FS) radiography by both phantom experiments and clinical studies. Receiver operating characteristic (ROC) curve analysis consisting of 25 normal and 25 artificially created simulated lesions on an orginally created Styrofoam phantom showed no difference in lesion detectability between FCR and FS radiography. Both were also equal in evaluation of the internal structure and margin of the 25 lesions by visual ranking. ROC curve analysis of clinical cases was performed in 30 cases, 20 normal and 10 abnormal, while evaluation by visual ranking was performed on 18 lesions. There was no significant difference between FCR and FS radiography either with ROC curve analysis or visual ranking, although the variations were somewhat greater in the clinical cases than in the phantom ...

1995-08-01

478

Computed radiography in X-ray examination of stomach. Evaluation by phantom experiments and clinical studies  

International Nuclear Information System (INIS)

The usefulness and clinical applicability of computed radiography(FCR) in X-ray examination of the stomach were evaluated in comparison with film-screen (FS) radiography by both phantom experiments and clinical studies. Receiver operating characteristic (ROC) curve analysis consisting of 25 normal and 25 artificially created simulated lesions on an orginally created Styrofoam phantom showed no difference in lesion detectability between FCR and FS radiography. Both were also equal in evaluation of the internal structure and margin of the 25 lesions by visual ranking. ROC curve analysis of clinical cases was performed in 30 cases, 20 normal and 10 abnormal, while evaluation by visual ranking was performed on 18 lesions. There was no significant difference between FCR and FS radiography either with ROC curve analysis or visual ranking, although the variations were somewhat greater in the clinical cases than in the phantom ...

1995-01-01

479

To study the role of dynamic magnetic resonance imaging in assessing the femoral head vascularity in intracapsular femoral neck fractures  

Energy Technology Data Exchange (ETDEWEB)

Intracapsular femoral neck fractures remain unsolved fractures even after improvement in techniques of diagnosis and internal fixation. Individuals who sustain displaced femoral neck fractures are at high risk of developing avascular necrosis and non-union. Although several methods for predicting the viability of femoral head have been reported, they are not effective or widely used because of unreliability, potential complications and technical difficulties. Dynamic MRI was introduced in the recent past as a simple, non-invasive technique to predict the femoral head viability after the femoral neck fractures. In this study role of dynamic MRI was studied in 30 patients with 31 intracapsular femoral neck fractures. Fractures were divided in to three types according to dynamic curve patterns on MRI evaluation and were followed up for 6 months to 2 years to observe the final outcome. Sensitivity, Specificity and the Accuracy of dynamic MRI in predicting vascularity ...

2010-09-15

480

To study the role of dynamic magnetic resonance imaging in assessing the femoral head vascularity in intracapsular femoral neck fractures  

International Nuclear Information System (INIS)

Intracapsular femoral neck fractures remain unsolved fractures even after improvement in techniques of diagnosis and internal fixation. Individuals who sustain displaced femoral neck fractures are at high risk of developing avascular necrosis and non-union. Although several methods for predicting the viability of femoral head have been reported, they are not effective or widely used because of unreliability, potential complications and technical difficulties. Dynamic MRI was introduced in the recent past as a simple, non-invasive technique to predict the femoral head viability after the femoral neck fractures. In this study role of dynamic MRI was studied in 30 patients with 31 intracapsular femoral neck fractures. Fractures were divided in to three types according to dynamic curve patterns on MRI evaluation and were followed up for 6 months to 2 years to observe the final outcome. Sensitivity, Specificity and the Accuracy of dynamic MRI in predicting vascularity ...

2010-09-01

481

Wavelength shift of lasing from a dye-doped asymmetrically deformed liquid jet  

International Nuclear Information System (INIS)

We examined the spectral behaviors of lasing from a asymmetrically deformed liquid jet (a ? 14 ?m) which is induced by a laterally flowing gas. Th liquid sample was methanols which contains DCM dye. When n distortion is induced, the lasing spectrum appears as two periodic peaks which are corresponding to the resonance modes of cylindrical cavity. As the distortion parameter exceeds about 4%, the lasing spectrum shifts continuously to short wavelength. When the distortion parameter reaches ? 10%, the amount of blue shift was ? 30 nm. The blue shift can be explained as the shift of optimum wavelength of threshold curves. From the absorption and fluorescence curve of liquid sample, we estimated the spoiled Q with the distortion parameter.

1997-11-01

482

The environmental Kuznets curve hypothesis for water pollution: Do regions matter?  

Energy Technology Data Exchange (ETDEWEB)

This study revisits the environmental Kuznets curve (EKC) hypothesis for water pollution by using a recent dynamic technique, which is the generalized method of moments (GMM) approach, for a board sample of 97 countries during the period 1980-2001. On a global scale, as we cannot obtain the EKC relationship between real income and biological oxygen demand (BOD) emissions, this paper further classifies these countries into four regional groups - Africa, Asia and Oceania, America, and Europe - to explore whether the different regions have different ECK relationships. The empirical results show evidence of the inverted U-shaped EKC relationships' existence in America and Europe, but not in Africa and Asia and Oceania. Thus, the regional difference of EKC for water pollution is supported. Furthermore, the estimated turning points are, approximately, US$13,956 and US$38,221 for America and Europe, respectively.

2010-01-15

483

The environmental Kuznets curve hypothesis for water pollution: Do regions matter?  

International Nuclear Information System (INIS)

This study revisits the environmental Kuznets curve (EKC) hypothesis for water pollution by using a recent dynamic technique, which is the generalized method of moments (GMM) approach, for a board sample of 97 countries during the period 1980-2001. On a global scale, as we cannot obtain the EKC relationship between real income and biological oxygen demand (BOD) emissions, this paper further classifies these countries into four regional groups - Africa, Asia and Oceania, America, and Europe - to explore whether the different regions have different ECK relationships. The empirical results show evidence of the inverted U-shaped EKC relationships' existence in America and Europe, but not in Africa and Asia and Oceania. Thus, the regional difference of EKC for water pollution is supported. Furthermore, the estimated turning points are, approximately, US$13,956 and US$38,221 for America and Europe, respectively.

2010-01-01

484

The environmental Kuznets curve hypothesis for water pollution. Do regions matter?  

Energy Technology Data Exchange (ETDEWEB)

This study revisits the environmental Kuznets curve (EKC) hypothesis for water pollution by using a recent dynamic technique, which is the generalized method of moments (GMM) approach, for a board sample of 97 countries during the period 1980-2001. On a global scale, as we cannot obtain the EKC relationship between real income and biological oxygen demand (BOD) emissions, this paper further classifies these countries into four regional groups - Africa, Asia and Oceania, America, and Europe - to explore whether the different regions have different ECK relationships. The empirical results show evidence of the inverted U-shaped EKC relationships' existence in America and Europe, but not in Africa and Asia and Oceania. Thus, the regional difference of EKC for water pollution is supported. Furthermore, the estimated turning points are, approximately, US$13,956 and US$38,221 for America and Europe, respectively. (author)

2010-01-15

485

Photoconductive ultraviolet detectors based on ZnO films  

British Library Electronic Table of Contents (United Kingdom)

Properties of photoconductive ultraviolet detectors fabricated on ZnO films were presented. Highly c-axis oriented ZnO films were grown on glass substrates by pulsed laser deposition. Ultraviolet photodetectors were fabricated based on metal-semiconductor-metal planar structures. The photoresponsivity and the quantum efficiency are much higher in the ultraviolet range than in the visible range, and the peak values are around 360nm. Photocurrent transients show that the detector has a large photocurrent with the peak value of 2.8mA, and a slow photoresponse with a rise time of 5min and a decay time of 7min. The response curve of the detector is fitted well with exponential curve. The large photocurrent should result from the both effects of the accumulation of conduction electrons and the d...

2006-01-01

486

On the Robustness of Robustness Checks of the Environmental Kuznets Curve Hypothesis  

British Library Electronic Table of Contents (United Kingdom)

Since its first inception in the debate on the relationship between environment and growth in 1992, the Environmental Kuznets Curve hypothesis (EKC hereafter) has been subject of continuous and intense scrutiny. The most recent line of investigation criticizes the EKC hypothesis on more fundamental grounds, in that it stresses the lack of sufficient statistical testing of the empirical relationship and questions the very existence of the notion of EKC. Attention is in particular drawn on the stationarity properties of the series involved?per capita emissions or concentrations and per capita GDP?and, in case of presence of unit roots, on the cointegration property that must be present for the EKC to be a well-defined concept. Only at that point can the researcher ask whether the long-run re...

2009-01-01

487

Influence of the curved geometrical shape on the thin shell buckling phenomenon behaviour  

British Library Electronic Table of Contents (United Kingdom)

The present paper deals with instabilities of long homogeneous and isotropic thin shells, characterized by geometrical non-linearities and imperfections, with reference to a bent helicoidally geometrical shape of particular interest for the helicoidal steam generators tube bundle. Apparently no data exist in the literature to describe the non-linear buckling behaviour of curved thin shells under external pressure, thus, the theoretical analyses based on the classical linear elastic theory, as expected, might be inadequate to evaluate the collapse load especially if the curvature is rather large. To the purpose of determining the buckling pressure load the effects of a pre-existing level of geometrical and technological imperfection, unavoidably caused by various manufacturing processes wer...

2009-01-01

488

FG Sge at the stage of dust shell ejection  

British Library Electronic Table of Contents (United Kingdom)

New photometric observations of the variable star FG Sge, a rapidly evolving planetary nebula nucleus, were performed in 2003?2008. On 230 nights, we obtained 86 UBV and 155 BV RI (or R c , I c ) magnitude estimates. The maximum amplitude of the V-band light variations was >8 m . Six deep minima and four high maxima were observed. Analysis of the light curve has shown that the pulsation period of the star remained constant since 1991 and was P = 115 days. We have studied the wavelength dependence of the extinction at various phases of the light curve. The blueing of the B-V color at deep minima is interpreted as the result of light scattering in the circumstellar dust shell of the star formed by preceding dust ejections since 1992. Our spectroscopic observations performed on nine nights in...

2009-01-01

489

Estimation of dry rubber content in natural rubber latex by differential scanning calorimetry  

British Library Electronic Table of Contents (United Kingdom)

Differential Scanning Calorimetry (DSC) is employed to study the changes in enthalpy of natural rubber latex samples when heated under a controlled temperature program. It is found that the mass normalized areas of the DSC curves between room temperature and 170??C for different latex samples are inversely proportional to the dry rubber content (DRC) of the samples, measured following the weighing and drying method. The changes in total enthalpy of the samples in this temperature range are interpreted as due to the variations in the quantity of water present in the samples. The measurements have been repeated by diluting selected samples with known quantities of water, and it is found that the normalized areas of the DSC curves are directly proportional to the amount of water added to the ...

2010-01-01

490

Estimation of "1"3"7Cs body burden in Japanese, 2  

International Nuclear Information System (INIS)

The biological half-life of "1"3"7Cs in the total body of human subjects was determined in 23 individuals of Japanese male adult in their normal works by measuring amount of "1"3"7Cs in both their total body and daily urine in the same period. For the group, the value was determined by averaging the half-lives for individuals, by comparing the mean body burden and the mean daily urinary excretion, or by applying a curve fitting method to the body burden estimate. The biological half-life averaged 86 days, ranging from 50 to 161 days. The averages of the biological half-lives for the group were 83, 87 and 82 days in the different periods of observation. By the curve fitting method, 85 days was found for the group. The biological half-life for the individuals depended on both body weight and age, to a lesser extent, of the subjects. (author).

491

Effect of defect local piles and dislocation multiplication on radiation hardening of metals  

International Nuclear Information System (INIS)

Computer experiments imitating specimen strain on tension with constant deformation rate have been carried out. A formation possibility of atmosphere from defects around gliding dislocations (I) and a work of Frank-Read sources (II) have been accounted for. In result deformation curves until stresses do not exceed a critical shear stress were calculated. Influence of effects (I) and (II) was analyzed. It is determined that both by pass of dislocations over defect ''atmospheres'' and dislocation multiplication can cause a peak in flow stress occurrence on the deformation curves. Reasons and conditions of such peak occurrence have been studied. 12 refs.; 9 figs. (author).

1990-05-22

492

Determine equilibrium absorption rates  

Energy Technology Data Exchange (ETDEWEB)

Process engineers can predict quickly and accurately the equilibrium behavior of simultaneous H/sub 2/S and CO/sub 2/ absorptions in monoethanolamine and diethanolamine systems by using the nomographs developed by H.K. Ferguson Co. Correlation lines for temperature and amine concentration provided with the loading curves make the nomographs useful for any combination of temperature, concentration, and liquid loadings. The accuracy of the nomographs is within the acceptable range for normal engineering applications when the operating parameters lie in the region of practical gas-treating conditions. Correction curves given for each nomograph to improve the accuracy are generally not needed except for cases where the gas loadings are higher than 0.5 mole/mole of amine.

1980-04-01

493

Corruption and the environmental Kuznets Curve: Empirical evidence for sulfur  

British Library Electronic Table of Contents (United Kingdom)

We investigate how corruption influences the income level at the turning point of the relationship between sulfur emissions and income, using a wide cross-national panel of countries, at different levels of development and with different degrees of corruption. Our results support the Environmental Kuznets Curve hypothesis for sulfur. We find evidence that the higher the country's degree of corruption, the higher the per capita income at the turning point, suggesting different income-pollution paths across countries due to corruption. We build upon a new specification for the EKC developed by Bradford et al. (2005) that avoids using nonlinear transformations of potentially nonstationary regressors in panel estimation. Also, we account for the indirect impact of corruption on emissions throu...

2010-01-01

494

Continuing the search for a fundamental law of mortality  

Energy Technology Data Exchange (ETDEWEB)

For 170 years, scientists have attempted to explain why consistent temporal patterns of death are observed among individuals within populations. Historical efforts to identify a {open_quotes}law of mortality{close_quotes} from these patterns ended in 1935 when it was declared that such a law did not exist. These empirical tests for a law of mortality were constructed using mortality curves based on all causes of death. We predicted that patterns of mortality consistent with the historical concept of a law would be revealed if mortality curves for species were constructed using only senescent causes of death. Using data on senescent mortality for laboratory animals and humans, we demonstrate that patterns of mortality overlap when compared on a biologically comparable time scale. These results are consistent with the existence of a law of mortality following sexual maturity as asserted by Benjamin Gompertz and Raymond Pearl. The societal, ...

1997-08-01

495

Continuing the search for a fundamental law of mortality  

Energy Technology Data Exchange (ETDEWEB)

for 170 years, scientists have attempted to explain why consistent temporal patterns of death are observed among individuals within populations. Historical efforts to identify a `law of mortality` from these patterns ended in 1935 when it was declared that such a law did not exist. These empirical tests for a law of mortality were constructed using mortality curves based on all causes of death. We predicted patterns of mortality consistent with the historical concept of a law would be revealed if mortality curves for species were constructed using only senescent causes of death. Using data on senescent mortality for laboratory animals and humans, we demonstrate patterns of mortality overlap when compared on a biologically comparable time scale. The results are consistent with the existence of a law of mortality following sexual maturity. The societal, medical, and research implications of such a law are discussed.

1996-03-01

496

Characteristics of infrared-stimulated luminescence from a feldspar at low temperatures  

International Nuclear Information System (INIS)

The characteristics of infrared-stimulated luminescence (IRSL) from a sample of potassium feldspar at low temperatures are presented. These studies extend the previous work from this laboratory on the optical bleaching characteristics and emission spectra of feldspars at room temperature and recent measurements of the stimulated spectrum for a sample of potassium feldspar at room temperature. Stimulation spectra have been measured at 290, 160 and 145 K. By fitting Gaussian functions to the spectra, the peak position is shown to shift to higher photon energies at lower temperatures and the full-width half-maximum of the peak to reduce with decreasing temperature. The variation of IRSL intensity with temperature for several stimulating wavelengths has been determined and the form of the IRSL decay curve measured at 290 and 160 K. No substantial differences were observed in the form of the decay curves at each temperature. (author).

1993-07-01

497

An empirical test of the environmental Kuznets curve in China: A panel cointegration approach  

British Library Electronic Table of Contents (United Kingdom)

This paper investigates the relationship between environmental pollution and economic growth in China based on the environmental Kuznets curve hypothesis, using Chinese provincial data over 1985?2005. Waste gas, waste water and solid wastes are used as environmental indicators and GDP is used as the economic indicator. It is found by panel cointegration test that there is a long-run cointegrating relationship between the per capita emission of three pollutants and the per capita GDP. According to comparisons with the dynamic OLS estimator and the Within OLS estimator, we find that panel cointegration estimation is preferable for all pollutants except for solid wastes. The results also show that all three pollutants are inverse U-shaped, and water pollution has been improved earlier than ga...

2008-01-01

498

Alloy 800: New stress rupture and creep data for pressurised components in high-temperature reactors  

International Nuclear Information System (INIS)

A new evaluation of the 1% time strain limit for creep strength and the isochronous stress/strain relationship was to be undertaken for the type 800 alloy, based on up to date experimental data. After the evaluation of the 1% time strain limit curves and time fracture curves of individual melts, multilinear regression analyses were made to clear up the relationship between parameters of the creep behaviour such as creep strength, 1% time strain limit and time fracture strain on the one hand and metallurgical parameters such as C, Ti, Al, Ni, Cr contents or grain size and type of manufacture, on the other hand. Based on the knowledge gained from these calculations, new limits were determined for HTR material specifications for variants of the 800 alloy of the Rk, NT, DE, and HT type. (orig./DG).

1988-10-06

499

Activity of ginsenoside Rh2 on the growth of mice splenic lymphocytes investigated by microcalorimetry and factor analysis  

British Library Electronic Table of Contents (United Kingdom)

The power?time curves of mice splenic lymphocytes growth at 37??C affected by ginsenoside Rh2 were determined by microcalorimetry using a 3114/3236 TAM air bioactivity monitor with ampoule mode. Then, the minimal inhibitory concentration (MIC) of Rh2 on splenic lymphocytes growth was determined by serial dilution method. From factor analysis (FA) on six quantitative thermokinetic parameters from the power?time curves, the activity of Rh2 on splenic lymphocytes could be quickly evaluated by analyzing the changes in the two main parameters: growth rate constant k, and maximum heat-output power, P m. The results showed that Rh2 had strong inhibitory activity on splenic lymphocytes growth, and this inhibitory activity was strengthened with increasing concentration of Rh2 in the concentration r...

2011-01-01

500

A Kuznets curve in environmental efficiency. An application on OECD countries  

Energy Technology Data Exchange (ETDEWEB)

The role of the environment is an important issue in policy making and the accurate assessment of the environmental conditions is vital. In this paper, using nonparametric techniques, an environmental efficiency index is developed for each of the OECD countries. These indexes allow one both to do cross section comparisons on the state of each country's production process in its treatment of undesirable outputs and also to trace each country's modification of their production processes overtime. Furthermore in this study we investigate the factors underlying societies' environmental concerns that eventually lead to changes in the environmental efficiency. The results provide further empirical evidence for the environmental Kuznets curve hypothesis. 16 refs.

2000-09-01