UK PubMed Central (United Kingdom)

Absolute measurements of cerebral blood flow (CBF) are an important endpoint in studies of cerebral pathophysiology. Currently no accepted method exists for in vivo longitudinal...Full Text Available

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A method is presented to derive the absolute dimensions of early-type detached binaries by combining the observed parameters with results of evolutionary computations. The method is used to obtain the absolute dimensions of nine close binaries. We find that most systems have an initial masss ratio near 1.

Science.gov (United States)

... The development of various modeling methods for conventional eddy current probes (absolute, differential, two-port, etc.) has led to a general ...

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Published in summary form only.

International Nuclear Information System (INIS)

Fifteen quantitative bone scintigraphies were performed in an adolescent girl during the follow-up of a femoral osteogenic sarcoma treated by chemotherapy and massive allograft. Three hours after injection of the radiopharmaceutical (7.4 MBq/kg of 99mTc-MDP) bone activity was measured in the inferior limbs at several regions of interest centered on the hips, femurs (proximal, middle, distal) and proximal tibias. The variations of relative bone activities A/S (ratio of corresponding counting rates between two homologous regions in the affected A and in the healthy S limb) and of absolute bone activities (expressed in counts/pixel-second) are interpreted as a function of times during treatment. The quantitative results are discussed with regard to main phenomena influencing bone activity in this particular clinical case: bone growth, chemotherapy and neo-osteogenesis in allograft.

International Nuclear Information System (INIS)

Absolute, cascade-free excitation cross sections in an ion have been measured for the resonance "2S#->#"2P transition in Zn"+ using electron-energy-loss and merged electron-ion beams methods. Measurements were carried out at electron energies of below threshold to 6 times threshold. Comparisons are made with 2-, 5-, and 15-state close-coupling and distorted-wave theories. There is good agreement between experiment and the 15-state close-coupling cross sections over the energy range of the calculations.

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Published in summary form only.

KoreaScience (Korea)

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Applying a total energy absorption {gamma}-ray detector composed of 12 bricks (5x5 cm{sup 2}, 7.5 cm thick) of Bi{sub 4}Ge{sub 3}O{sub 12}(BGO) scintillators, the absolute measurement of capture cross sections for Au and Sb has been made in an energy region between 0.01 eV and 10 eV using the linac time-of-flight method. Incident thermal neutron flux was absolutely determined by using the BGO detection system with a Sm sample. To extend the neutron flux measurement from the thermal neutron region to higher neutron energy, the {sup 10}B(n, {alpha} {gamma}) reaction was applied. Absolute capture yield for the relevant capture sample was obtained by the saturated capture yield at a large resonance of the sample. Gold was selected to investigate the application of the BGO detection system to the absolute measurement of the capture cross sections, since the {sup 197}Au(n, {gamma}){sup ...

UK PubMed Central (United Kingdom)

OBJECTIVE AND DESIGNThis study used qualitative and quantitative methods to examine the reasons primary care physicians and nurses offered for their inability to initiate guideline-concordant...Full Text Available

International Nuclear Information System (INIS)

Measurements of absolute differential cross sections for H"+-H_2 direct, single-, and double-charge-transfer scattering at 0.5, 1.5, and 5.0 keV are reported at laboratory scattering angles less than 1 degree with an angular resolution of approximately 0.02 degree. The cross sections exhibit deep interference oscillations in single-charge-transfer scattering, but no such oscillations are present in direct and double-charge-transfer scattering. Theoretical cross sections derived using the diatoms-in-molecules method to describe the molecular states in a semiclassical molecular-orbital three-state close-coupling model within a semiclassical framework agree satisfactorily with the experimental results.

International Nuclear Information System (INIS)

The Comprehensive Nuclear-Test-Ban-Treaty (CTBT), which was opened for signature in 1996, bans all nuclear explosions in all environments. Republic of Korea has been working to monitor compliance with CTBT by deterring and detecting any nuclear explosions conducted anywhere on Earth. For the verification of CTBT, several techniques are implemented. Radionuclide monitoring is of particular importance since it is the only method which can provide absolute assurance that a nuclear detonation has occurred

British Library Electronic Table of Contents (United Kingdom)

This study assesses the current state of undergraduate instruction in empirical research methods in communication and offers recommendations for enhancing such instruction. Responses to an online questionnaire were received from 149 communication-related programs at four-year colleges and universities. Just over 85% of responding programs offered an empirical methods course. Although the course often covered both qualitative and quantitative methods, instruction was heavily slanted toward quantitative methods and topics common to both qualitative and quantitative inquiry. The empirical methods course was usually required for graduation, but it was typically not well integrated with the rest of the curriculum and taken late in students' undergraduate careers. Additional analyses examined st...

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It is both experimentally and theoretically demonstrated that ion flow velocity at an arbitrary angle with respect to the magnetic field can be measured with a directional Langmuir probe. Based on the symmetry argument, we show that the effect of magnetic field on directional probe current is exactly canceled in determining the ion flow velocity, and obtain the generalized relation between flow velocity and directional probe currents valid for any flowing direction. The absolute value of the flow velocity is determined by an in situ calibration method of the probe. The applicability limit of the present method to a strongly ion-magnetized plasma is experimentally examined. (author)

UK PubMed Central (United Kingdom)

Motivation: Cell tracking is an important method to quantitatively analyze time-lapse microscopy data. While numerous methods and tools exist for tracking cells in 2D time-lapse images,...Full Text Available

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The authors experimentally study the separate stages of the determination of iodine in thyroidin by the combustion method in a flask with oxygen. The monotypic, conventional procedures and the procedure of Kolii and Pakhomov were studied. With addition of potassium iodide, a sixfold amount (compared with the initial) of iodine is liberated. Further, the liberated iodine is titrated by sodium thiosulfate. The authors find the degree of influence of a high nitrogen content on the determination of iodine in organic compounds. The procedure developed for the quantitative determination of the iodine in thyroidin by the combustion method is simple, fairly rapid, and can be used for the reliable control of the quality of thyroidin preparations and its starting raw material.

British Library Electronic Table of Contents (United Kingdom)

Determination of thermal to fast neutron flux ratio (ffast) and fast neutron flux (phi-fast) is required for fast neutron reactions, fast neutron activation analysis, and for correcting interference reactions. The ffast and subsequently phi-fast were determined using the absolute method. The ffast ranged from 48 to 155, and the phi-fast was found in the range 1.03x1010-4.89x1010 n cm-2 s-1. These values indicate an acceptable conformity and applicable for installation of the fast neutron facility at the MNA research reactor.

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.).

Energy Technology Data Exchange (ETDEWEB)

ExternE is a pan{sub E}uropean project aimed at identifying and quantifying external effects from different energy production technologies around Europe. The Swedish implementation carried out case studies on a biomass plant, a coal plant and a hydro power plant. The conventional approach within the ExternE project is to estimate impacts for each priority pathway associated with the fuel cycle, and then economic methods to obtain estimates for the economic damage of each particular impact pathway. However, in the case of hydro power, it is generally not possible to estimate the most important impacts quantitatively. Therefore, a contingent valuation (CV) study was initiated. In a typical CV-study, a selection of individuals are asked to state their willingness to pay for a certain environmental improvement or to avoid an environmental damage. Welfare economic theory suggests that the well-being effects on people from a change from one situation ...

UK PubMed Central (United Kingdom)

Aims:To Study the religious and ideological views and practice of Palliative Care physician towards Euthanasia.Materials and Methods:An...Full Text Available

UK PubMed Central (United Kingdom)

Arbuscular mycorrhizal fungi (AMF) are obligate biotrophs, known to play an important role in ecological processes. Conventional light microscopy is the most common method used to detect their presence...Full Text Available

CERN Document Server

Particle swarm optimization (PSO) is extensively used for real parameter optimization in diverse fields of study. This paper describes an application of PSO to the problem of designing a fractional-order proportional-integral-derivative (FOPID) controller whose parameters comprise proportionality constant, integral constant, derivative constant, integral order (lambda) and derivative order (delta). The presence of five optimizable parameters makes the task of designing a FOPID controller more challenging than conventional PID controller design. Our design method focuses on minimizing the Integral Time Absolute Error (ITAE) criterion. The digital realization of the deigned system utilizes the Tustin operator-based continued fraction expansion scheme. We carry out a simulation that illustrates the effectiveness of the proposed approach especially for realizing fractional-order plants. This paper also attempts to study the behavior of fractional ...

Science.gov (United States)

The millimeter microwave source of gyrotron-traveling-wave amplifier (gyro-TWT) is capable of generating high power coherent radiation in a broad bandwidth, while its performance is severely deteriorated by the stability problems. This paper focuses on modeling and the stability analysis of the Naval Research Laboratory (NRL) Ka-band TE{sub 01} mode gyro-TWT based on an interaction circuit alternately loaded with lossy ceramic shells and metal rings. The propagation characteristics of the interaction circuit is analyzed first, based on which the boundary impedance method is employed to build an equivalent uniform lossy circuit. Then the stability of the interaction system is studied using linear and nonlinear theories. The analysis reveals that, due to the special waveguide structure and the dielectric loss, the propagation characteristics of the complex waveguide are similar to that of a uniform lossy circuit. The analysis of the absolute ...

International Nuclear Information System (INIS)

Absolute total cross sections for electron-impact excitation of the 2s"2S#->#2p"2P transition in C"3"+ were measured from 7.35 eV to 8.45 eV using the merged electron-ion-beams energy-loss technique. The results settle the discrepancy between two previous experiments using the crossed-beams fluorescence method, being in very good agreement with the older results [P. O. Taylor, D. Gregory, G. H. Dunn, R. A. Phaneuf, and D. H. Crandall, Phys. Rev. Lett. 39, 1256 (1977)] but less so with the more recent ones [D. W. Savin, L. D. Gardner, D. B. Reisenfeld, A. R. Young, and J. L. Kohl, Phys. Rev. A 51, 2162 (1995)]. The present measurements are also in good agreement with unitarized Coulomb-Born and close-coupling calculations. copyright 1998 The American Physical Society.

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High dose rate (HDR) brachytherapy for treating a cervix carcinoma has become popular, because it eliminates many of the problems associated with conventional brachytherapy. In order to improve the clinical effectiveness with HDR brachytherapy, a dose calculation algorithm, optimization procedures, and image registrations need to be verified by comparing the dose distributions from a planning computer and those from a humanoid phantom. In this study, the humanoid phantom was fabricated in order to verify the absolute doses and the relative dose distributions. The measured doses from the humanoid phantom were then compared with the treatment planning system for the dose verification. The humanoid phantom needs to be designed such that the dose distributions can be quantitatively evaluated thermoluminescent dosimeter (TLD) chips with a dimension of 1/8 and film dosimetry with a spatial resolution of <1 mm used to measure the radiation ...

Energy Technology Data Exchange (ETDEWEB)

During the past three years the program has undergone a substantial revitalization. There has been no significant change in the scientific direction of this grant, in which emphasis continues to be placed on developing new or improved methods of obtaining quantitative data from radiotracer imaging studies. However, considerable scientific progress has been made in the three areas of interest: Radiochemistry, Quantitative Methodologies, and Experimental Methods and Feasibility Studies, resulting in a sharper focus of perspective and improved integration of the overall scientific effort. Changes in Faculty and staff, including development of new collaborations, have contributed to this, as has acquisition of additional and new equipment and renovations and expansion of the core facilities. 121 refs., 30 figs., 2 tabs.

International Nuclear Information System (INIS)

Neutron radiography (NR) is a useful non-destructive method for determination of hydrogen content in various building and technical materials. Monitoring of transport processes of moisture and hydrogenous liquids in porous building materials is enabled by fast, quasi-real-time NR methods based on novel imaging plate neutron detectors (IP-NDs). Hydrogen content in the samples is determined by quantitative analysis of measured profiles of neutron attenuation in the samples. Detailed description of quantitative NR method is presented by the authors in another accompanying contribution at this conference. Deterioration of building materials is originated by different processes that all require presence of water therefore it is essential to limit or prevent the transport of water through the porous material. In this presentation, results of a study of clay brick impregnation by silicone ...

International Nuclear Information System (INIS)

The need for noninvasive sensitive techniques for the diagnosis and follow-up of metabolic bone disease in dialysis patients has stimulated the author's interest in the efficacy of more detailed quantitative bone scintigraphy. Using hemodialysis to reduce elevated soft-tissue activity at scintigraphy, an attempt was made to assess the diagnostic sensitivity of quantitative bone scintigraphy as compared to qualitative bone scintigraphic, biochemical, radiographic and bone histologic studies. The second aim of these studies was to determine if one of the two major components of renal osteodystrophy is a major determinant for skeletal radiotracer uptake. The clinical observations on the efficacy and possible specificity of quantitative bone scintigraphy in the diagnosis and follow-up during treatment of renal osteodystrophy are presented briefly in this chapter. Thus, the use of scintigraphy for the routine detection and ...

International Nuclear Information System (INIS)

An important unresolved issue in outcomes analysis for lung complications is the effect of poor or completely lacking heterogeneity corrections in previously archived treatment plans. To estimate this effect, we developed a novel method based on Monte Carlo (MC) dose calculations which can be applied retrospectively to RTOG/AAPM-style archived treatment plans (ATP). We applied this method to 218 archived nonsmall cell lung cancer lung treatment plans that were originally calculated either without heterogeneity corrections or with primitive corrections. To retrospectively specify beam weights and wedges, beams were broken into Monte Carlo-generated beamlets, simulated using the VMC++ code, and mathematical optimization was used to match the archived water-based dose distributions. The derived beam weights (and any wedge effects) were then applied to Monte Carlo beamlets regenerated based on the patient computed tomography densities. Validation ...

International Nuclear Information System (INIS)

A new microdensitometry method for quantitative assessment of bone mineral content using Fuji computed radiography (FCR) was developed and the results were compared with those obtained by the conventional film-screen method. Using both methods, X-ray pictures of the 2nd metacarpal bone were taken with a reference aluminum step wedge in nine normal subjects and nine parameters representing the width and density of bone marrow and cortex were calculated in middle of the bone shaft. Interobserver reproducibility assessed for three parameters was significantly higher in the FCR method than the conventional one. The value of #SIGMA#GS computed by the FCR method, that is equivalent to the net bone density of the transverse section of the shaft, showed higher correlation with the one obtained by computed tomography in comparison with the conventional ...

Science.gov (United States)

The ultimate compressive strength of 36 thoracolumbar vertebrae was determined experimentally. In addition, the trabecular bone mineral content was measured by single energy quantitative computed tomography. The areas of fractured endplates were also determined by computed tomography. The results show that a linear relationship exists between the compressive strength and the product of bone density and endplate area. These data allow an in vivo prediction of vertebral body strength using a noninvasive method with a standard error of estimate amounting to less than 0.95 kN. PMID:3212488

Science.gov (United States)

The theory of a method of determination of reactivity from power spectral density measurements with /sup 252/Cf and the results of experiments with a critical assembly mockup of a liquid-metal fast breeder reactor (LMFBR) and with uranium (93.2 wt % /sup 235/U) metal cylinders and a sphere are presented. This method of reactivity determination has an advantage over existing methods in that it determines the reactivity only from properties of the reactor at the subcritical state of interest and thus does not require a calibration near delayed criticality. In these experiments, the reactivity was varied by changing the fissile loading or the amount of neutron absorber inserted; for the LMFBR mockup, the reactivity varied to approximately 75 dollars subcritical, and for the uranium metal assemblies to approximately 30 dollars subcritical. These experiments verified for the first time the predictions of theory that could be ...

International Nuclear Information System (INIS)

Purpose: To evaluate a simple method for quantification of focal activity in bone scintigraphy (BS). Material and methods: The gamma camera was calibrated using a phantom. Quantitative bone scintigraphy (QBS) was performed on 11 men recently diagnosed with prostate cancer (PCa), for whom routine BS showed involvement of the skeleton. Following endocrine therapy for 4 to 8 months, a second QBS was performed. Changes in QBS values were then compared to changes in serum levels of prostate-specific antigen (PSA). Results: PSA response indicating regression of PCa was accompanied by a decrease in the QBS value in 8 of the 11 patients. The overall mean error of the QBS values was 15%. conclusion: QBS according to this method is a relatively simple procedure that might contribute to objective evaluation of therapeutic effects in skeletal metastases, although its validity must be tested in a larger clinical ...

International Nuclear Information System (INIS)

Abstract only.

British Library Electronic Table of Contents (United Kingdom)

The adsorption of CO2 on a number of activated carbons, thermal carbon black, and oxide materials at 195 K was studied using static and dynamic techniques. The landing surface areas ?(CO2) ? 0.19 nm2 on thermal carbon black and the absolute values of sorption for P/P 0 < 0.4 were determined. The density of adsorbed CO2 in the micropore volume was estimated at ?(CO2) = 0.91 g/cm3. It was demonstrated that the previously found effect of a weakening of the sorption interaction of nitrogen molecules with thin-walled materials (which manifested itself in an analysis of sorption isotherms by a comparative method) was pronounced to a lesser degree for the sorption of CO2. At the same time, the presence of supermicropores in activated carbon samples resulted in overestimated values of surface area...

British Library Electronic Table of Contents (United Kingdom)

'If you wish to foresee the future of mathematics our proper course is to study the history and present condition of the science.' Henri Poincare 'It is India that gave us the ingenious method of expressing all numbers by ten symbols, each symbol receiving a value of position, as well as an absolute value. We shall appreciate the grandeur of the achievement when we remember that it escaped the genius of Archimedes and Apollonius.' P.S. Laplace 'The Greeks were the first mathematicians who are still 'real' to us today. Oriental mathematics may be an interesting curiosity, but Greek mathematics is the real thing. The Greek first spoke of a language which modern mathematicians can understand.' G.H. Hardy This article deals with a short history of mathematics and mathematical scientists during...

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Thirty-four patients with prostatic carcinoma were studied with quantitative bone scintigraphy and whole-body counting (WBC) 1 and 24 h after injection of [sup 99m]Tc-MDP before as well as two weeks and two months after orchiectomy. Thirteen of the patients had normal bone scintigrams and WBR at the three different investigations; 21 had skeletal metastases. The latter showed throughout the study higher local gamma camera count rates as well as WBR values than the patiens with normal scintigrams. In these patients a ''flare phenomenon'', with an increase in count rate two weeks after orchiectomy followed by a decrease two months post-operatively, was seen with quantitative bone scintigraphy but not with WBC. However, WBC may be a valuable method indicating the total extent of skeletal metastases in the body, while quantitative bone scintigraphy is more accurate in the ...

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Skeletal radiotracer (sup(99m)Tc-HEDP) uptake was quantitated with and without the aid of a computer in 30 chronic dialysis patients with histologic evidence of renal osteodystrophy. Before scintigraphy, elevated soft-tissue activity due to the absence of renal radiotracer excretion was reduced by hemodialysis. The results were compared with those of a normal group and with the results of the biochemical and the bone morphometric studies of these patients. In all patients the radiotracer uptake was elevated, often markedly. In several patients with minimal histologic bone disease, however, soft-tissue activity could not be normalized by hemodialysis although its influence on the quantitative data could be further reduced (but not excluded) by computer evaluation of skeletal radiotracer uptake. Since the latter technique clearly distinguished the majority of the patients from the normals, it appears that computerized ...

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Nowadays, the floating production, storage, and offloading (FPSO) units are used to marginal oil fields and deep seas, because of mobility and reduced lead time from discovery to first production. One of the methods for offloading is to moor a tanker alongside the FPSO unit. In this case motion response of the system becomes highly complex, and will be affected by many factors such as hydrodynamic interaction and mechanical connections between the vessels. In this study, a quite general method is developed which has taken into account the hydrodynamic interaction as well as the effects of connectors and mooring lines, in motion response analysis of a multi-body floating system. For this purpose, 3-D source distribution method is applied for hydrodynamic analysis, and linear stiffness matrices are introduced to represent the effect of connectors and mooring lines on the motion equations. The method has ...

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Quantitative hepatic scintiangiography was previously used for evaluating the relative contribution of hepatic arterial and portal venous blood flows to the hepatic circulation. The present study compares 3 different procedures (automatic and manual integration, and slope fitting methods) for analyzing the hepatic time activity curves obtained after bolus i.v. injection of 370 MBq /sup 99m/Tc-diethylentriaminopentacetic acid. Twenty five subjects were studied: Five controls, ten cirrhotics, and ten portal hypertensive patients previously submitted to side to side portacaval anastomosis. The correspondence between results given by the different methods was satisfactory only in shunted patients, and the reproducibility of computed parameters was quite poor for all procedures. Accordingly, none of the methods can be considered as supporting reliable quantitative pathophysiological ...

Science.gov (United States)

An intemted approach to building a networking infrastructure is an absolute necessiry for meeting the multidisciplinary science networking requirements of ...

Science.gov (United States)

In this article, we propose a model selection method, the Bayesian composite model space approach, to map quantitative trait loci (QTL) in a half-sib population for continuous and binary traits. In our method, the identity-by-descent-based variance component model is used. To demonstrate the performance of this model, the method was applied to map QTL underlying production traits on BTA6 in a Chinese half-sib dairy cattle population. A total of four QTLs were detected, whereas only one QTL was identified using the traditional least square (LS) method. We also conducted two simulation experiments to validate the efficiency of our method. The results suggest that the proposed method based on a multiple-QTL model is efficient in mapping multiple QTL for an outbred half-sib population and is more powerful than the LS method ...

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The part of the FFTF Reactor Characterization Program reported in this paper is a measurement of absolute fission rates of eight major fuel isotopes at two different positions within the reactor. The instruments employed in these tests were fission ionization chambers for which the absolute efficiency and fissionable deposit mass assay have been rigorously established.

British Library Electronic Table of Contents (United Kingdom)

In this paper we present the results of time series analysis for a coal mining region based on partial unmixing. We test the method also known as mixture tuned matched filtering on an eight image Landsat 5 TM and Landsat 7 ETM+ time series covering the period from 1987 to 2003. Common change detection methods often include the comparison of two interactively generated classification results, such as derived from Maximum Likelihood classification. These approaches often yield highly accurate results. However, disadvantages include a strong analyst bias and hardly repeatable results. For a quantitative monitoring of a single surface class' development over time they are often not recommendable. Our goal was to test an unbiased quantitative way to assess the development of coal surfaces, such...

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...

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Development of an assessment framework and indicators can be used to evaluate effectiveness of wetland restoration. Example of these include index of biotic integrity and the hydrogeomorphic method. Both approaches provide qualitative ranks. We propose a new method based on the EPA wetland research program. Similar to other methods, indexes are compared to reference communities; however, the comparisons are quantitative. In this paper we discuss the results of our framework using the Pen Branch riparian wetland system as an example.

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This paper describes a novel Fourier transform infrared (FTIR) spectroscopic method that can be used to rapidly screen soil samples from potentially hazardous waste sites. Samples are heated in a thermal desorption unit and the resultant vapors are collected and analyzed in a long-path gas cell mounted in a FTIR. Laboratory analysis of a soil sample by FTIR takes approximately 10 minutes. This method has been developed to identify and quantify microgram concentrations of explosives in soil samples and is directly applicable to the detection of selected volatile organics, semivolatile organics, and pesticides.

Energy Technology Data Exchange (ETDEWEB)

The United States Air Force School of Aerospace Medicine (USAFSAM) tests the quantitative fit of masks which are worn by military personnel during nuclear, biological, and chemical warfare. Subjects are placed in a Dynatech-Frontier Fit Testing Chamber, salt air is fed into the chamber, and samples of air are drawn from the mask and the chamber. The ratio of salt air outside the mask to salt air inside the mask is called the quantitative fit factor. A motion-time study was conducted to evaluate the efficiency of the layout and work method presently used in the laboratory. A link analysis was done to determine equipment priorities, and the link data and design guidelines were used to develop three proposed laboratory designs. The proposals were evaluated by projecting the time and motion efficiency, and the energy expended working in each design. Also evaluated were the lengths of the equipment links for each proposal, and ...

Science.gov (United States)

A statistical method is presented for detecting quantitative trait loci (QTLs), based on the linear model. Unlike methods able to detect a few well separated QTLs and to estimate their effects and positions, this method considers the genome as a whole and enables the detection of chromosomal segments involved in the differences between two homozygous lines, and their backcross, doubled haploid, or F[sub 2] progenies, for a quantitative trait. Genetic markers must be codominant, but missing markers are accepted, provided they are missing independently from the experiment. Asymptotic properties, which are of practical use, are developed. This method does not rely on strong genetic hypotheses, and thus does not permit any precise genetic analysis of the trait under study, but it does assess which regions of the genome are involved, whatever the complexity of the ...

CERN Document Server

The method of spectral disentangling has now created the opportunity for studying the chemical composition in previously inaccessible components of binary and multiple stars. This in turn makes it possible to trace their chemical evolution, a vital aspect in understanding the evolution of stellar systems. We review different ways to reconstruct individual spectra from eclipsing and non-eclipsing systems, and then concentrate on some recent applications to detached binaries with high-mass and intermediate-mass stars, and Algol-type mass-transfer systems.

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The authors study the nonuniformity of a-Si:H films obtained by the method of vacuum condensation, with the help of x-ray small-angle scattering (SLS) and transmission electron microscopy. Films of hydrogenated amorphous silicon are greatest interest, because the electronic properties of this material can be controlled by doping. As a result of the compensation of the ruptured bonds, and possibly, effects of melting, the properties of such films are analogous to those of singlecrystalline silicon. XLS enables a quantitative determination of the prameters of the regions of low electron density (RLD) in such objects.

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Laser-Induced Breakdown Spectroscopy was selected by NASA as part of the ChemCam instrument package for the Mars Science Laboratory rover to be launched in 2009. ChemCam's Laser-Induced Breakdown Spectroscopy instrument will ablate surface coatings from materials and measure the elemental composition of underlying rocks and soils at distances from 1 up to 10 m. The purpose of our studies is to develop an analytical methodology enabling identification and quantitative analysis of these geological materials in the context of the ChemCam's Laser-Induced Breakdown Spectroscopy instrument performance. The study presented here focuses on several terrestrial rock samples which were analyzed by Laser-Induced Breakdown Spectroscopy at an intermediate stand-off distance (3 m) and in an atmosphere similar to the Martian one (9 mbar CO{sub 2}). The experimental results highlight the matrix effects and the measurement inaccuracies due to the noise accumulated ...

Wastenet

... There is an evident, growing public discontent among supervisors and regulators with quantitative risk evaluation techniques, including Value-at-Risk and similar methods, so it is surprising to see the same authorities now advocating their use in more doubtful circumstances to risk weight bonuses. Deferrals and claw backs ...

Energy Technology Data Exchange (ETDEWEB)

Critical properties of a fluid or fluid mixtures are important for describing fluid phase behavior, predicting physical properties, developing equations of state, and designing supercritical-fluid extraction processes, and compression and refrigeration units. The predictive capability of the Peng-Robinson-Styjek-Vera (PRSV-2) equation of state (1986) for critical properties of binary mixtures was investigated. The procedure adopted by Heidemann and Khalil (1980) and discussed by Abu-Eishah et al. (1998) was followed. An optimized value for the binary interaction parameter based on minimization of error between experimental and predicted critical temperatures was used. The standard and the average of the absolute relative deviations in critical properties are included. The predicted critical temperature and pressure for several nonpolar and polar systems agree well with experimental data and are always better than those predicted by the group-contribution ...

International Nuclear Information System (INIS)

Purpose/Objective: With the advent of computed tomography and magnetic resonance imaging, the three dimensional representation of the patient anatomy has become an invaluable resource for better diagnosis and delineation of the target volume and sensitive structures in radiation therapy. Although the therapeutic linear accelerator industry has made available highly sophisticated equipment, the aggressiveness in dose prescription and delivery has to be complimented by accurate dose computation methods. We have adopted a convolution/superposition algorithm for the calculation of absolute dose that fully accounts for the external shape and internal structure of the patient for photon treatment radiotherapy. In this paper, we will discuss the principles of the convolution algorithm and we will show how the computed dose compares to clinically relevant treatment techniques. Materials and Methods: A computer controlled data ...

Science.gov (United States)

Methods for the synthesis and quantitation of the novel choline analogues, telluronium choline and acetyltelluronium choline, are described. An assay procedure utilizing pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) with cold trapping was developed with [2H4]telluronium choline and [2H4]acetyltelluronium choline as internal standards. The telluronium compounds were ion-pair extracted from tissue with dipicrylamine, washed with 2-butanone, and pyrolyzed prior to GC-MS analysis. The compounds were monitored using selected ion monitoring at m/z 232 and m/z 190 for acetyltelluronium and telluronium choline, respectively, and at m/z 236 and m/z 194 for the analogous deuterated internal standards. The assay was linear over a range of 20 pmol-20 nmol of compound taken through the assay. PMID:8130881

British Library Electronic Table of Contents (United Kingdom)

To define the quantitative and qualitative effects of gossypol (GP) on deer (Cervus elaphus) semen, the animals were fed cottonseed (CS). Adult stags each received 350?g of CS for 109?days. Animals received 15?mg of gossypol per kilogram body weight per day. Quantitative and qualitative parameters of experimental ejaculates (n?=?182) were compared to ejaculates (n?=?571) of control animals (n?=?5) collected during three previous natural reproductive seasons. Ejaculate fractions were evaluated by classical methods used in domestic animals. In this paper, we show that mature male deer fed CS exhibited morphological changes and decreased motility of spermatozoa and abnormalities in spermatogenesis. Radioimmunoassay measured concentrations of various steroid hormones (T-testosterone, A4-andros...

Science.gov (United States)

Ab initio lattice dynamics based on linear response method are performed for high pressure phase of yttrium to describe electron-phonon coupling and subsequent superconducting behavior. The critical temperature Tc in fcc-Y increases monotonically with pressure up to 9.25 K at 31 GPa, which is quantitatively in excellent agreement with two quasihydrostatic experiments and is qualitatively compatible with recent experiments. The excellent agreement with experiments gives us a better understanding of the effective pseudopotential ?* as well as spectral function ?2(?)F(?) in yttrium. These results demonstrate that there exists strong electron-phonon coupling in Y within the studied pressure regime, and for lower pressure electron correlation becomes stronger. Generally, it is found that superconductivity in yttrium under pressure can be described quantitatively within standard theory of phonon-mediated superconductivity.

British Library Electronic Table of Contents (United Kingdom)

Nowadays there are many sun-protection cosmetics incorporating organic or inorganic UV filters as active ingredients. Chemically stable inorganic sunscreen agents, usually metal oxides, are widely employed in high-SPF (sun protection factor) products. Titanium dioxide is one of the most frequently used inorganic UV filters. It has been used as a pigment for a long period of cosmetic history. With the development of micronization techniques, it has become possible to incorporate titanium dioxide in sunscreen formulations without the previous whitening effect, and hence its use in cosmetics has become an important research topic. However, there are very few works related to quantitation of titanium dioxide in sunscreen products. In this research, we analysed the amounts of titanium dioxide i...

Science.gov (United States)

The authors described a method for determination of tissue renin activity with heterologous substrate. The preparation of the substrate was performed at several stages: salting with amonium sulfate; dialisis of the precipitate till complete separation of amonium sulfate molecules; distruction of angiotensinases by interchangeble souring and alcalization of the medium; lyophylization of the pure substrate. The obtained renin-substrate was preserved in ampules and its usage had a series of advantages--duration, economic, a possibility for standartization of the determination, etc., which were described in details in the article. The described in details also the quantitative determination of the renin activity in the tissues (renal and cerebral) with the help of the obtained substrate as the moments, modiied by the authors, were indicated. PMID:436712

Energy Technology Data Exchange (ETDEWEB)

The refrigerant two-phase flows in a distributor and a simulated plate heat exchanger with a single passage used in a compression-type refrigerator were visualized by real-time neutron radiography. For a distributor, the liquid fraction in the each tube was measured by some image processing method. On the other hand, for a plate heat exchanger, the two-dimensional distribution of void fraction was measured quantitatively by the umbra method. As a result, it was shown that the dynamic behaviors of refrigerant at the inlet of the section strongly affected on the performance, that is, a distribution performance of a distributor and a liquid distribution in a plate heat exchanger. (author)

Energy Technology Data Exchange (ETDEWEB)

A method is proposed for the quantitative isolation of radiothallium in gas form from proton-bombarded lead of mass up to 20 g. The molten lead is kept at about 800 K in hydrofluoric-acid vapor (HF/H/sub 2/O approx. = 1) at a reduced pressure (less than or equal to4 Pa). We used 99.9% lead with the U-240 cyclotron at the Nuclear Research Institute, Academy of Sciences of the Ukrainian SSR, or the phasotron at the Join Nuclear Research Institute, which gave protons at 65 and 680 MeV correspondingly.

Energy Technology Data Exchange (ETDEWEB)

In the framework of the carbon storage two forestry methods are analyzed by the author: the standing capitalization (slowing of the crops) and the spices substitution (slow growing species by fast growing species). The construction of a model taking into account the all stage of the carbon implication (biomass, soil, forest products) offers simulation and quantitative results on these methods. (A.L.B.)

International Nuclear Information System (INIS)

Qualitative technetium Tc 99m bone scintigraphy using phosphate compounds and gallium 67 scintigraphy were described as a helpful means in diagnosing necrotizing external otitis (NEO). They were, however, claimed to be nonspecific. Quantitative Tc 99m methylene diphosphonate bone scintigraphy and gallium 67 scintigraphy were performed in eight patients with NEO and in 20 patients with severe external otitis, in order to prove usefulness of scintigraphy in the diagnosis of NEO. Ratios of lesion to nonlesion for bone scintigraphy were 1.67 #+-# 0.16 in patients with NEO and 1.08 #+-# 0.09 in patients with severe external otitis, and for gallium 67 scintigraphy they were 1.35 #+-# 0.24 in NEO patients and 1.05 #+-# 0.03 in patients with severe external otitis. There was no difference in uptake between diabetic patients with severe external otitis and nondiabetic patients. The scintigraphic studies were also evaluated using a qualitative scoring ...

CERN Document Server

We demonstrate the use of a variational method to determine a quantitative lower bound on the rate of convergence of Markov Chain Monte Carlo (MCMC) algorithms as a function of the target density and proposal density. The bound relies on approximating the second largest eigenvalue in the spectrum of the MCMC operator using a variational principle and the approach is applicable to problems with continuous state spaces. We apply the method to one dimensional examples with Gaussian and quartic target densities, and we contrast the performance of the basic Metropolis-Hastings algorithms with a ``smart'' variant that incorporates gradient information into the trial moves. We find that the variational method agrees quite closely with numerical simulations. We also see that the smart MCMC algorithm often fails to converge geometrically in the tails of the target density except in the simplest case we examine, ...

CERN Document Server

The previous decade has brought a remarkable increase of the interest in applications that deal with querying and mining of time series data. Many of the research efforts in this context have focused on introducing new representation methods for dimensionality reduction or novel similarity measures for the underlying data. In the vast majority of cases, each individual work introducing a particular method has made specific claims and, aside from the occasional theoretical justifications, provided quantitative experimental observations. However, for the most part, the comparative aspects of these experiments were too narrowly focused on demonstrating the benefits of the proposed methods over some of the previously introduced ones. In order to provide a comprehensive validation, we conducted an extensive experimental study re-implementing eight different time series representations and nine similarity ...

International Nuclear Information System (INIS)

The purpose of the present study is to develop a new method for chemical state analysis by means of EPMA(Electron probe microanalyser). The measured X-ray intensity of Si-K#beta# characteristic X-ray spectra were read-out by a 16 bit microcomputer with a RS-232C interface. And using the curve fitting method the quantitative analysis of chemical compositions in a ternary compound that constituted of the same element has been established. The present method was applied to analyse of the friction and wear properties of Si-base ceramics sliding materials. It was found that the wear debris contains both the compositions of the sliding materials and SiO_2, and the SiO_2 contents in wear debris was changed with relative humidity. The results clearly showed that the proposed method is very useful for determing the compositions in the ternary compound. (author).

Energy Technology Data Exchange (ETDEWEB)

The aim of this paper is offering a critical review of Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS), the approach of multi-elemental quantitative analysis of LIBS spectra, based on the measurement of line intensities and plasma properties (plasma electron density and temperature) and on the assumption of a Boltzmann population of excited levels, which does not require the use of calibration curves or matrix-matched standards. The first part of this review focuses on the applications of the CF-LIBS method. Quantitative results reported in the literature, obtained in the analysis of various materials and in a wide range of experimental conditions, are summarized, with a special emphasis on the departure from nominal composition values. The second part is a discussion of the simplifying assumptions which lie at the basis of the CF-LIBS algorithm (stoichiometric ablation and complete atomization, thermal ...

Energy Technology Data Exchange (ETDEWEB)

By using this doping method, silicon semiconductors with extremely uniform dopant distributions can be produced, and this is the dominant advantage of NTD compared with a conventional chemical doping. Good uniformity of a dopant concentration is usually required for high power applications such as thyristor (SCR), IGBT, IGCT and GTO and for special sensors. Achieving an accurate neutron fluence corresponding to a target resistivity as well as a uniform irradiation is the prime target of a neutron irradiation for NTD. Generally, in order to reach an accurate neutron fluence, a real time neutron flux is monitored by a neutron detector such as a Self-powered Neutron Detector(SPND). And, after an irradiation, the total irradiation fluence is confirmed by measuring the absolute activity of a neutron activation sample that has been irradiated with a silicon ingot, and thus the SPND can be properly calibrated. Excellent irradiation uniformity and a ...

International Nuclear Information System (INIS)

A bulge-disk decomposition is made for 737 spiral and lenticular galaxies drawn from a Sloan Digital Sky Survey galaxy sample for which morphological types are estimated. We carry out the bulge-disk decomposition using the growth curve fitting method. It is found that bulge properties, effective radius, effective surface brightness, and also absolute magnitude, change systematically with the morphological sequence; from early to late types, the size becomes somewhat larger, and surface brightness and luminosity fainter. In contrast, disks are nearly universal, their properties remaining similar among disk galaxies irrespective of detailed morphologies from S0 to Sc. While these tendencies were often discussed in previous studies, the present study confirms them based on a large homogeneous magnitude-limited field galaxy sample with morphological types estimated. The systematic change of bulge-to-total luminosity ratio, B/T, along the ...

Energy Technology Data Exchange (ETDEWEB)

The research and development for the first year of the project are performed through specialization of researchers, information from aborad and international cooperation, securement of advanced nuclear technology, development and installation of test equipment, application of external man-power, establishment of advanced test techniques, and certified test method. 1. Absolute efficiency measurement examination technology development of gamma scanning system 2. Sample preparation technology development of SEM and EPMA for micro-structural observation and chemical composition analysis 3. Irradiated high burn-up nuclear fuel transportation and test for PWR 4. Development of hot cell examination techniques and equipment 5. Acquirement of KOLAS system. In addition to the project, the following activities are carried out as follows; - PIE of Hanaro fuel(KH99H-001) - PIE of U-Mo advanced nuclear fuel irradiated at Hanaro - PIE of Hi-MET advanced ...

Science.gov (United States)

Least-squares analyses were performed on a set of atomic masses using standard and generalized senaiempirical mass laws. Presumably because of errors in the assured form of the standand mass law, its least-squares coefficients can be determined at best to an accuracy of about 10%, and masses are predicted with an uncertainty of several Mev/c/sup 2/. The standard mass law was generalized by addition of shell effect and deformation terms. While the least-squares fitting of the generalized mass law is better than for the standard mass law, it is still not possible to predict atomic masses to an accuracy better than a few Mev/c/sup 2/. The nuclear deformations and the well depth . of the nuclear interaction obtained from the additional mass-law terms are in reasonable agreement with more accurate determinations by other methods. A similar statement applies to the nuclear radius constant as obtained from the least-squares coefficient of ...

Energy Technology Data Exchange (ETDEWEB)

We suggest and describe the use of a binary pseudo-random (BPR) grating as a standard test surface for measurement of the modulation transfer function (MTF) of interferometric microscopes. Knowledge of the MTF of a microscope is absolutely necessary to convert the measured height distribution of a surface undergoing metrology into an accurate power spectral density (PSD) distribution. For an'ideal' microscope with an MTF function independent of spatial frequency out to the Nyquist frequency of the detector array with zero response at higher spatial frequencies, a BPR grating would produce a flat 1D PSD spectrum, independent of spatial frequency. For a'real' instrument, the MTF is found as the square root of the ratio of the PSD spectrum measured with the BPR grating to the'ideal,' spatial frequency independent, PSD spectrum. We present the results from a measurement of the MTF of MicromapTM-570 interferometric ...

UK PubMed Central (United Kingdom)

BackgroundThrough differentiation processes, keratinocytes provide a physical barrier to our bodies and control skin features such as moisturization, wrinkles and pigmentation. Keratinocyte...Full Text Available

International Nuclear Information System (INIS)

Quantitative, experimentally based assessments of the biases of the methods used to develop the neutronics design of the FTR are presented together with brief descriptions of the design methods. Uncertainties in biases have been established that are sufficiently small to allow a high degree of confidence in the nuclear design. Experimental data for these assessments have been developed in full-scale zero-power mockups of the final design of the reactor, except for Doppler data from SEFOR. Temperature, power coefficient, and stability methods evaluations are necessarily deferred to acceptance testing during initial startup of the FTR. Sodium voiding and small sample worths continue to be the technical areas of greatest complexity with least experiment-theory correlation. Critical mass, Doppler effects, control rod worth, and spatial power distribution have generally good experiment-theory correlations.

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...

British Library Electronic Table of Contents (United Kingdom)

Derivative spectrophotometry and bivariate calibration algorithm were used for study of run of photooxidation of levomepromazine hydrochloride (LV). The actual concentrations of LV and its main degradation product levomepromazine sulphoxide (LV-SO) were calculated using data provided by applied methods. The direct reading of absorbance values at 302nm and 334nm were employed for quantification of LV and LV-SO, respectively, in the case of bivariate method. The derivative spectrophotometric method is based on transformation of zero-order spectra into first derivative. The values of first derivative at 334nm were used for quantification of LV while at 278nm for assay of LV-SO. The obtained quantitative data were applied for investigation of kinetics of photodegradation of LV.

Science.gov (United States)

This work investigates the potential use of simultaneously near-infrared (NIR) and mid-infrared (MIR) spectroscopies for the quantitative analysis of fatty acids and triacylglycerols and for identifying the Registered Designation of Origin (RDO) of extra virgin olive oils. The two spectral ranges were used separately using PLS and PLS-DA regressions. To combine both information, concatenated matrix was used at the first time, multiblock method using H-PLS models were constructed at the second time. The models were compared in terms of prediction errors. The results obtained with MIR spectroscopy are better than the ones obtained with NIR spectroscopy. The H-PLS methodology seems to be very interesting for quantitative analysis with the use of additional information in the NIR range, which is not present in the MIR one. For RDO identification by discriminant analysis, the use of multiblock method was ...

International Nuclear Information System (INIS)

Mass distributions of fragments in the low-energy fission of nuclei from "1"8"7Ir to "2"1"3At have been analysed. This analysis has shown that shell effects in symmetric-mode fragment mass yields from the fission of pre-actinide nuclei could be described if one assumes the existence of two strongly deformed neutron shells in the arising fragments with neutron numbers N_1#approx#52 and N_2#approx#68. A new method has been proposed for quantitatively describing the mass distributions of the symmetric fission mode for pre-actinides with A#approx#180-220. (orig.)

Science.gov (United States)

Leachability of neutron irradiated fly ash is investigated as a method for studying element leaching properties of this material with various leaching media. Quantitative aspects of radiation damage are shown to be minor. Therefore, the technique should be applicable for this purpose. It is further shown that this technique affords significant advantages over the conventional post-leaching analysis with respect to utilization of natural solutions for the investigation of fly ash leachability. However, for a few elements such as Pb, Bi, V, and Al, the various nuclear parameters involved invalidate applicability of the present technique.

International Nuclear Information System (INIS)

An interferometric technique for hard X-rays is presented. It is based on two transmission gratings and a phase-stepping technique, and it provides separate radiographs of the phase and absorption profiles of bulk samples. Tomographic reconstruction yields quantitative three-dimensional maps of the X-ray refractive index and of the attenuation coefficient, with a spatial resolution down to a few microns. The method is mechanically robust, it requires little monochromaticity, and can be scaled up to large fields of view. These are important prerequisites for use with laboratory X-ray sources. Numerous applications ranging from wave front sensing to medical radiography are presently under investigation.

Energy Technology Data Exchange (ETDEWEB)

The addition of carbon to samples, during imaging, presents a barrier to accurate TEM analysis, the controlled deposition of hydrocarbons by a focused electron beam can be a useful technique for local nanometer-scale sculpting of material. Here we use hydrocarbon deposition to form nanopores from larger focused ion beam (FIB) holes in silicon nitride membranes. Using this method, we close 100-200nm diameter holes to diameters of 10nm and below, with deposition rates of 0.6nm per minute. I-V characteristics of electrolytic flow through these nanopores agree quantitatively with a one dimensional model at all examined salt concentrations.

CERN Document Server

We provide a both qualitative and quantitative comparison among different approaches aimed to solve the problem of non-linear diffusive acceleration of particles at shocks. In particular, we show that state-of-the-art models (numerical, Monte Carlo and semi-analytical), even if based on different physical assumptions and implementations, for typical environmental parameters lead to very consistent results in terms of shock hydrodynamics, cosmic ray spectrum and also escaping flux spectrum and anisotropy. Strong points and limits of each approach are also discussed, as a function of the problem one wants to study.

Energy Technology Data Exchange (ETDEWEB)

Cross sections for some electro- and photoinduced spallation reactions on {sup 27}Al and {sup 51}V are measured in the energy region 130 MeV to 580 MeV with the activation method. Comparisons are made with calculations based on the Dalitz formalism for virtual photon spectra, and Monte Carlo calculations based on a cascade evaporation model, respectively. By use of Bremsstrahlung with end-point energies from threshold to 750 MeV, the yields for photo- production of{pi}{sup -}leading to ground and isomeric states in {sup 197}Hg are measured with the activation method. The activity from the Hg-isotopes were measured after a chemical separation of Hg from the target material. The yields and isomeric ratios are compared with impulse approximation calculations. For the photoproduction of {sup 195m}Hg and {sup 192}Hg from {sup 197}Au, the yields were measured. The experimental mean cross sections are compared with data from other experiments and with ...

Energy Technology Data Exchange (ETDEWEB)

Here the authors try to dissolve some commonly held misconceptions about the operation of eddy current probes used for inspecting heat exchanger tubes. With the help of computer model results, the authors demonstrate that, for optimized operation, absolute/differential probes should be operated with coil current flowing in phase with another. This month's feature should be of interest to researchers as well as for NDT field personnel.

Energy Technology Data Exchange (ETDEWEB)

A 'Laboratory of Quantitative Methods in Monument Research' is being built at the CTU Prague. Its primary orientation is the investigation of historic architecture, although other objects of art can also be investigated. In the first phase, two radiation methods are being established, but it is set up in such a way, that various other methods can readily be added in its future development. The radiation methods chosen for the initial development of the laboratory are: thermoluminescence dating and X-ray fluorescence analysis. The design of the automated TL-reader, built in our laboratories, is adjusted for the purpose of dating of historic brick architecture (which, of course, does not exclude applications for ceramics and other materials). The investigation of renaissance architecture in southern Bohemia and Moravia is under preparation as the first large campaign ...

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...

British Library Electronic Table of Contents (United Kingdom)

Eddy current testing is one of the most widely used methods in non-destructive testing for the inspection of conductive materials. Numerical modelling of eddy current testing has emerged as an important approach alongside experimental studies. This paper investigates an application of numerical modelling and experimental study as a means of the quantitative non-destructive evaluation (QNDE) of defects in conductive samples. There are two methods of measuring eddy current response, more commonly by measuring the change in impedance of the eddy current probe coil, or as used in this work, by measuring the change in magnetic field directly using magnetic field sensors such as superconducting quantum interference devices, giant magneto resistance, or as in this case Hall sensors. Specifically,...

International Nuclear Information System (INIS)

The authors have evaluated bone mineral content in the vertebral spongiosa by means of Computed Tomography. The method proposed by Genant and Cann [17, 18] has been applied to examine 164 healthy volunteers and 108 patients. Both healthy males and females showed a progressive bone mineral loss increasing with age; the bone mineral loss was most severe in females during the 4th and 5th decade of life. Pathology included patients with osteoporotic fractures (vertebral and femural neck), patients with partial gastrectomy, renal failure, primary hyperparathyroidism, Cushing syndrome, corticosteroid therapy. Bone mineral values were significantly lower in most pathologic groups. Computed Tomography proves thus to be a valuable method to assess bone mineral content and to identify patients at risk for fractures.

Energy Technology Data Exchange (ETDEWEB)

The Eddy covariance technique allows to measure different components of turbulent air fluxes, including the flow of water vapour. Sap flux measurements determine directly the water flow in tree stems. We compared the water flux just above the crowns of trees in a forest by the technique of Eddy covariance and the water flux by the xylem sap flux method. These two completely different approaches showed a good qualitative correspondence. The correlation coefficient is 0.8. With an estimation of the crown diameter of the measured tree we also find a very good quantitative agreement. (author) 3 figs., 5 refs.

Energy Technology Data Exchange (ETDEWEB)

The murine 3T3-L1 fibroblast under appropriate incubation conditions differentiates into an adipocyte phenotype. This 3T3-L1 adipocyte exhibits many of the morphologic, biochemical, and insulin-responsive features of the normal rodent adipocyte. Using quantitative electron microscopic (EM) autoradiography we find that, when /sup 125/I-insulin is incubated with 3T3-L1 adipocytes, the ligand at early times of incubation localizes to the plasma membrane of the cell preferentially to microvilli and coated pits. When the incubation is continued at 37 degrees C, /sup 125/I-insulin is internalized by the cells and preferential binding to the villous surface is lost. With the internalization of the ligand, two intracellular structures become labeled, as determined by the method of hypothetical grain analysis. These include large clear, presumably endocytotic, vesicles and multivesicular bodies. Over the first hour of incubation the labeling of these ...

Energy Technology Data Exchange (ETDEWEB)

Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS) has been proposed several years ago as an approach for quantitative analysis of Laser-Induced Breakdown Spectroscopy spectra. Recently developed refinement of the spectral processing method is described in the present work. Accurate quantitative results have been demonstrated for several metallic alloys. However, the degree of accuracy that can be achieved with Calibration-Free Laser-Induced Breakdown Spectroscopy analysis of generic samples still needs to be thoroughly investigated. The authors have undertaken a systematic study of errors and biasing factors affecting the calculation in the Calibration-Free Laser-Induced Breakdown Spectroscopy spectra processing. These factors may be classified in three main groups: 1) experimental aberrations (intensity fluctuations and inaccuracy in the correction for spectral efficiency of a detection system), 2) inaccuracy ...

Energy Technology Data Exchange (ETDEWEB)

There are several methods for the risk assessment and risk management applied to pipelines, among them the Muhlbauer's Method. W. Kent Muhlbauer is an internationally recognized authority on pipeline risk management. He made a detailed identification about 300 distinct conditions that influence the risk assessment in pipelines and he proposed a score system that is known as method of Muhlbauer. The purpose of this model is to evaluate the public exposure to the risk and identify ways for management that risk in fact. The assessment is made by the attribution of quantitative values to the several items that influences in the pipeline risk. This paper approaches the Muhlbauer's basic model for risk assessment and management in pipelines. In the beginning, the basic model for risk assessment is presented, and methodology for pipelines in onshore environment is detailed. After, presents ...

International Nuclear Information System (INIS)

Electron probe microanalysis (EPMA) offers high sensitivity and high accuracy in quantitative measurements of chemical compositions and mass coverages. Owing to the low detection limits of the wavelength-dispersive technique, monolayers with mass coverages of about 0.05 pg cm z can be detected. Assuming a density of 5 g cm--3 this corresponds to a thickness of 0.1 nm. With these advantages in mind, EPMA was extended to depth profile analysis in the sub-micron range using a surface removal technique. The present paper shows how depth profile analysis can be improved by combining EPMA and the focused ion beam (FIB) technique. The focused ion beam system uses a Ga+ ion beam. The ion beam allows the milling of defined geometries on the nanometer scale, so that very shallow bevels with exactly defined angles in relation to the surface can be obtained. Low surface damage is expected due to low sputtering effects. Calibrated WDX measurements along the bevel deliver ...

Energy Technology Data Exchange (ETDEWEB)

The overall objective of this project has been to develop immunochemical methods to quantitate unique DNA base damages in order to facilitate studies on radiation-induced damage production and repair. Specifically, we have been using antibodies raised to damaged bases to quantitate unique lesions in model systems in order to evaluate their potential biological consequences. Our approach has been to synthesize modified nucleotides or nucleosides, conjugate them to protein carriers, and use the conjugates as immunogens in rabbits or to prepare monoclonal antibodies. We have been studying damages that are stable radiolysis products found in X-irradiated DNA and thus of potential biological consequence. Our aim is to build an in vitro and in vivo data base on the interactions between model DNA lesions and such cellular enzymes as DNA polymerases and repair endonucleases. Initial studies have focused on pyrimidine ring ...

Energy Technology Data Exchange (ETDEWEB)

The objectives of the project were to demonstrate and evaluate several small-scale methods of harvesting small (200 mm or less) trees and chipping them for fuel, as well as a method of processing such chips for use in dry chip-fired heating appliances. Nine field trials were conducted using various combinations of equipment. The trials consisted of 2 slash reclamation tests, 2 thinning tests, and 5 clear-cutting tests. The tests were conducted on various sites ranging from 0.2 to 1.8 hectares in area. The trees harvested were small; their average stem diameter was 70 mm. Every site was measured before harvest to predict the amount of biomass present. The amount of material obtained from the sites varied from 50% to 80% of the biomass present. Harvesting consisted of chain-saw felling and delimbing, skidding to roadside using winch, and then chipping into a 30 m{sup 3} portable bin. At the processing facility, the chips were weighed and dumped, ...

UK PubMed Central (United Kingdom)

The evaluation of biological markers is recognized as necessary to the future of toxicology, epidemiology, and quantitative risk assessment. For biological markers to become widely accepted, their validity...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

This research aims at elucidating thermal hydraulic phenomena by carrying out their visualization and measurement which are difficult by conventional method, utilizing the excellent properties of real time neutron radiography and showing the usefulness of neutron radiography. The experiments were carried out on the visualization and measurement of liquid metal flow and mixed phase flow and the visualization and diagnosis of mixed phase flow equipment. As the achievement in this fiscal year, the image-processing method for visualizing quantitatively the distribution of void fraction in gas-liquid two-phase flow has been devised, therefore, its method and results are reported. For the analysis of multi-dimensional two-phase flow, in order to prepare the model and determine the constitution equation, the data on the multi-dimensional distribution of void fraction are required. Void fraction is defined. The ...

Science.gov (United States)

A multicentre evaluation of the urine test strip analyser Super Aution-4220 was carried out in six laboratories. The analytical performance of the instrument with regard to imprecision, linearity, detection limit, drift, carry-over and method comparison was studied. Using the Aution stick 8 test strip the pH, glucose, protein, ketones, bilirubin, blood, urobilinogen and leukocyte esterase were analysed. Specific gravity measurements were performed by refractive index method. Within-run and between-run imprecision determined at three levels of analyte were good. No carry-over was observed. Obtained results were linear through all the described analytical range. No significant drift was detected. Method comparison with some quantitative methods was performed and showed a good correlation with most of the analytes. The study of interferences showed minor interferences by common ...

Energy Technology Data Exchange (ETDEWEB)

The absolute cross section of the [sup 3]He([ital n],[gamma])[sup 4]He reaction was measured at five energies between [ital E][sub [ital n

UK PubMed Central (United Kingdom)

The clotting activity of Staphylococcus aureus strain 104 was purified 46,000-fold, but absolute purity was not achieved. Carbohydrate content of the purified material was not more than 5%. Elution...Full Text Available

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

Energy Technology Data Exchange (ETDEWEB)

Absolute fission rate measurements using modified National Bureau of Standards fission chambers were performed in the Fast Flux Test Facility at two core locations for isotopic deposits of {sup 232}Th, {sup 233}U, {sup 235}U, {sup 238}U, {sup 237}Np, {sup 239}Pu, {sup 240}Pu, and {sup 241}Pu. Monitor chamber results at a third location were analyzed to support other experiments involving passive dosimeter fission rate determinations.

CERN Document Server

Liquid-liquid wetting failure is investigated in a two-dimensional Couette system with two immiscible fluids of arbitrary viscosity. The problem is solved exactly using a sharp interface treatment of hydrodynamics (lubrication theory) as a function of the capillary number, viscous ratio and separation of scale, i.e. slip length versus macroscopic scale of the system. The existence of critical velocities, above which no stationary solutions are found, is analyzed in detail in terms of the relevant parameters of the system. Comparisons with existing analysis for other geometries are also carried out. A numerical method of analysis is also presented, based on diffuse interface models obtained from multiphase extensions of the lattice Boltzmann equation (LBE). Sharp interface and diffuse interface models are quantitatively compared face to face indicating the correct limit of applicability of the diffuse interface models.

Energy Technology Data Exchange (ETDEWEB)

A new methodology for three-dimensional (3-D) numerical modeling of the continuous steel casting process is presented and evaluated. The results are compared with available experimental data obtained in a water-oil mold model for various flow rates and immersion depths of the submerged entry nozzle. The water-oil interface pattern at the top of the mold is also investigated. Wave formation and evolution in time is simulated with a volume tracking method. The predicted flow field inside the mold exhibits quite satisfactory agreement with the corresponding measurements, whereas some quantitative differences are observed referring to the final wave amplitude at low casting speeds. Conclusions of scientific and engineering importance concerning both the computer algorithm and the mold performance are also drawn.

CERN Document Server

We have combined perturbative unitarity and renormalisation group equation arguments in order to find a dynamical way to constrain the space of the gauge couplings ($g'_1$, \\widetilde{g}$) of the so-called "Minimal $Z'$ Models". We have analysed the role of the gauge couplings evolution in the perturbative stability of the two-to-two body scattering amplitudes of the vector and scalar sectors of these models and we have shown that perturbative unitarity imposes an upper bound that is generally stronger than the triviality constraint. We have also demonstrated how this method quantitatively refines the usual triviality bound in the case of benchmark scenarios such as the $U(1)_\\chi$, the $U(1)_R$ or the "pure" $U(1)_{B-L}$ extension of the Standard Model. Finally, a description of the underlying model structure in Feynman gauge is provided.

International Nuclear Information System (INIS)

Quantitative structure activity relationship (QSAR) analysis of the correlations between initial brain uptake and structure parameters, for example lipophilicity F_r, molar refractivity MR and electronic parameters #sigma#_1 of the "9"9Tc"m-N_2S_2 complexes have been studied with multiple regression analysis method. The main structural factors which affect the initial brain uptake of this kind of brain imaging agents have been discussed. The results may give some theoretical information for designing new brain imaging agents

Energy Technology Data Exchange (ETDEWEB)

Mass distributions of fragments in the low-energy fission of nuclei from {sup 187}Ir to {sup 213}At have been analysed. This analysis has shown that shell effects in symmetric-mode fragment mass yields from the fission of pre-actinide nuclei could be described if one assumes the existence of two strongly deformed neutron shells in the arising fragments with neutron numbers N{sub 1}{approx}52 and N{sub 2}{approx}68. A new method has been proposed for quantitatively describing the mass distributions of the symmetric fission mode for pre-actinides with A{approx}180-220. (orig.) 28 refs.

British Library Electronic Table of Contents (United Kingdom)

Porous flow occurs in a wide range of materials and applies to many commercially relevant applications such as oil recovery, chemical reactors and contaminant transport in soils. Typically, breakthrough and pressure curves of column floods are used in the laboratory characterization of these materials. These characterization methods lack the detail to easily and unambiguously resolve flow mechanisms with similar effects at the core scale that can dominate at the aquifer or oil field scale, as well as the effects of geometry that control the flow at interfaces as in a perforated well or the inlet of an improperly designed column. Non-invasive imaging techniques such as MRI have been shown to provide a far more detailed characterization of the properties of the solid matrix and flow, but usu...

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As thin films become increasingly popular (for solar cells, LEDs, microelectronics, batteries), quantitative morphological information is needed to predict and optimize the film's electronic, optical and mechanical properties. This quantification can be obtained quickly and easily with X-ray diffraction using an area detector and synchrotron radiation in two simple geometries. In this paper, we describe a methodology for constructing complete pole figures for thin films with fiber texture (isotropic in-plane orientation). We demonstrate this technique on semicrystalline polymer films, self-assembled nanoparticle semiconductor films, and randomly-packed metallic nanoparticle films. This method can be immediately implemented to help understand the relationship between film processing and microstructure, enabling the development of better and less expensive electronic and optoelectronic devices.

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Real-time neutron radiography was demonstrated to be a viable and useful tool in studying water flow in unsaturated media. The experiment was designed to test the method for following water flow. The wetting front advance, water-flow patterns, and neutron attenuation density were observed in a 7.7-cm diameter sand column. The advance was fit with a simple i = A t/sup B/ equation yielding an excellent correlation. Theoretical calculations presented estimate the minimum and maximum detectable water content in various sizes of columns. The ability of real-time neutron radiography to allow both qualitative and quantitative spatial and time measurements to be made in an nonintrusive manner was demonstrated.

British Library Electronic Table of Contents (United Kingdom)

Noninvasive prediction of vertebral body strength under compressive loading condition is a valuable tool for the assessment of clinical fractures. This paper presents an effective specimen-specific approach for noninvasive prediction of human vertebral strength using a nonlinear finite element (FE) model and an image based parameter based on the quantitative computed tomography (QCT). Nine thoracolumbar vertebrae excised from three cadavers with an average age of 42 years old were used as the samples. The samples were scanned using the QCT. Then, a segmentation technique was performed on each QCT sectional image. The segmented images were then converted into three-dimensional FE models for linear and nonlinear analyses. A new material model was implemented in our nonlinear model being more...

British Library Electronic Table of Contents (United Kingdom)

Terrain attributes derived from digital elevation models have been used widely for mapping soil organic matter (SOM). Among these attributes, the topographic wetness index (TWI), an index for quantitatively indicating the balance between water accumulation and drainage conditions at the local scale, has been shown to correlate with SOM. However, TWIs used in most studies are calculated using a single-flow-direction (SFD) algorithm, which assumes that all water from a grid cell flows into only one neighboring cell. This assumption is not always valid, especially in areas with low relief where movement of water may be divergent. To overcome this SFD limitation, a multiple-flow-direction (MFD) algorithm has been developed, which distributes flow from a grid cell to several downslope neighbors...

International Nuclear Information System (INIS)

The purpose of this work is the elucidation of the f"n electronic structure of neutral mono base adducts derived from tris(#eta#"5-cyclopentadienyl)-lanthanide(III) (Cp_2Ln). The available data on related compounds like bis adducts and anionic mono adducts of the same moiety was also analyzed. The first aim was to derive the experimental crystal field splitting pattern from optical, magnetooptical and magnetochemical measurements and to reproduce it using an empirical Hamiltonian operator. The eigenvalues and eigenvectors obtained in this manner were used for a quantitative interpretation of the magnetochemical, EPR- and NMR-spectroscopic properties. For the latter subject it was necessary to develop an own procedure for the NMR analysis of paramagnetic compounds. This method is based on factor analysis and as demonstrated in the second part of this work, is clearly superior to all previous procedures. (orig.).

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A first-principles quasiparticle approach to the electronic excitation energies in crystals and at surfaces is described. The quasiparticle energies are calculated within the GW approximation for comparison with photoemission and other spectroscopic experiments. Applications of the method to bulk semiconductors and the Si(111)2[times]l, Ge(111)2[times]l. and H/Si(III) surfaces are presented. In both cases, significant self-energy corrections arising from many-electron effects to the excitation energies are found. Using atomic positions from total energy minimization, the calculated excitation energies explain quantitatively the experimental spectra. This approach thus provides an ab initio means for analyzing and predicting results from spectroscopic probes.

British Library Electronic Table of Contents (United Kingdom)

Background: Quantifying HIV levels in mucosal secretions is essential to study compartmentalized expression of HIV and facilitate development of intervention strategies to prevent disease progression and transmission. Objectives: To develop a sensitive, reliable, and cost-effective technique to quantify HIV from blood and vaginal secretions that is compatible with efficient implementation in clinical research environments. Study design: A sensitive, reliable, internally-controlled real-time reverse transcriptase (RT) PCR assay, which uses the HIV-1 pol gene as a target (Hpol assay) was developed to quantify HIV levels in plasma and genital secretions, and compared to the widely used Roche Amplicor(TM) HIV-1 Monitor assay. In addition, a simplified method of sample collection and processing...

International Nuclear Information System (INIS)

Pyrochemical processing of nuclear fuels using molten salts has attracted much attention because of its potential to be applied for a future spent nuclear fuel management. In the pyrochemical processing, there are a number of steps to electro-refine and electro-win each element of lanthanides and actinides, commonly called trans-uranic elements (TRU). In order to materialize the pyrochemical processing in the nuclear power plant environments, qualitatively and quantitatively monitoring of each elements is necessary. Thus, we have undertaken to develop an on-line observing system of the TRU in LiCl-KCl molten salt media by using electrochemical and spectroscopic methods. In this work, the electrochemical and spectroscopic behaviors of europium as a proxy material for TRU were investigated simultaneously in the LiCl-KCl molten salt

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Twenty-six patients with late complications following femoral neck fracture were examined with both skeletal and bone marrow radionuclide scintimetry. There was no correlation between the methods with respect to the quantitative assessment of femoral head vascularity based on different uptake ratios comparing the fractured and the intact side. Skeletal scintimetry always had good image quality and permitted reliable differentation between nonunion of the fracture and late segmental collapse, in contrast to bone marrow scintimetry which gave poor image quality. Skeletal scintimetry thus seems superior to bone marrow scintimetry for assessment and differential diagnosis of late complications following femoral neck fracture. It is emphasized that the physiological mechanisms for radionuclide uptake must be taken into account when comparing scintimetric studies using different tracers.

British Library Electronic Table of Contents (United Kingdom)

Abstract Lysis and extraction of cells are essential sample processing steps for investigations pertaining to metabolism of xenobiotics in cell culture studies. Of particular importance to these procedures are maintaining high lysis efficiency and analyte integrity as they influence the qualitative and quantitative distribution of drug and toxicant metabolites in the intra- and extracellular milieus. In this study we have compared the efficiency of different procedures viz. homogenization, sonication, bead beating, and molecular grinding resin treatment for disruption of HT-29 colon cells exposed to benzo(a)pyrene (BaP), a polycyclic aromatic hydrocarbon (PAH) compound and a suspected colon carcinogen. Also, we have evaluated the efficiency of various procedures for extracting BaP parent c...

International Nuclear Information System (INIS)

In this work, a water-soluble polymer, polyethylenimine (PEI) was used for the simultaneous separation and preconcentration of trace Cu and Mn prior to their determination by flame atomic absorption spectrometry. For this purpose, the sample and the PEI solution were mixed and the metal-bound polymer was precipitated by adding acetone. The precipitate was separated and dissolved in a minimum amounts of water and aspirated into a flame AAS. By increasing the ratio of the volumes of sample to water used in dissolving the precipitate, the analyte elements were concentrated as needed. The sorption is quantitative in the pH ?6. Detection limits were 5.2 ?g/L for Cu and 5.4 ?g/L for Mn. This method is simple, fast and precise.

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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...

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In order to maintain a safe operation and availability of generating facilities, qualitative and quantitative assessment of piping vibration was performed vibration sources and damages of piping support was identified on the second piping system of Wolsung nuclear power plant unit 1 .Inspected piping supports and structures in both hot and cold condition .Established evaluation procedures of piping vibration .Performed the static analysis of 2 nd piping system .Established optimal vibration reducing method .The measured vibration level after installing rigid supports and energy absorbing type restraint was reduced about 7 times in velocity unit (author). 24 refs., 95 figs.

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The quantitative determination of oxide concentration by laser-induced breakdown spectroscopy is relevant in various fields of applications (e.g.: analysis of ores, concrete, slag). Calibration free laser-induced breakdown spectroscopy and the multivariate calibration are among the methods employed for quantitative concentration analysis of complex materials. We measured the intensity of neutral and ionized atomic emission lines of oxide materials by laser-induced breakdown spectroscopy and we modified the calibration free laser-induced breakdown spectroscopy method to increase the accuracy. The concentration of oxides was obtained by using stoichiometric relations. Sample materials were prepared from oxide powder (Fe{sub 2}O{sub 3}, MgO, CaO) by mixing and pressing. The concentration was 9.8-33.3 wt.% Fe{sub 2}O{sub 3}, 7.6-33.3 wt.% MgO and 33.3-81.2 wt.% CaO for different samples. Nd:YAG laser ...

Science.gov (United States)

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The brain hypothermia treatment is an attractive therapy for the neurologist because of its neuroprotection in hypoxic-ischemic encephalopathy patients. The present paper deals with the possibility of controlling the brain and other viscera in different temperatures from the viewpoint of system control. It is theoretically attempted to realize the special brain hypothermia treatment to cool only the head but to warm the body by using the simple apparatus such as the cooling cap, muffler and warming blanket. For this purpose, a biothermal system concerning the temperature difference between the brain and the other thoracico-abdominal viscus is synthesized from the biothermal model of hypothermic patient. The output controllability and the asymptotic stability of the system are examined on the basis of its structure. Then, the maximum temperature difference to be realized is shown dependent on the temperature range of the apparatus and also on the maximum gain determined from the ...

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Objective. To compare turbo inversion recovery magnitude (TIRM) with standard T1-weighted (T1-W) and T2-weighted (T2-W) MR sequences in the very early detection of acute osteomyelitis in children. Materials and methods. In 15 children with osteomyelitis, 15 sets of T1-W spin-echo (SE) (TR/TE, 400-640/12-17), T2-W turbo spin-echo (TSE) (TR/TE/ETL, 3290-4465/112-120/11), and TIRM (TR/TE/TI, 4000-6120/60/160) images were acquired with a 1.0-T magnet. Contrast-to-noise (C/N) ratios and percentage of signal between lesion and normal bone marrow were analysed with a computer-assisted image analysing system in a region of interest (ROI). Results. In 13 of 15 patients, the absolute signal enhancement in a ROI on the TIRM images was better than on the T1-W SE and T2-W TSE images and in 14 of 15 cases, C/N ratios were also better on the TIRM images than on the other sequences. In the other cases, the TIRM signal was diagnostically equivalent. On the TIRM ...

International Nuclear Information System (INIS)

An outline is given of time-dependent wavepacket methods as applied to calculations of molecular collisions with solid surfaces. The methods reviewed include numerical integration algorithms for the time-dependent Schroedinger equation, semiclassical wavepacket treatments, and approximations that treat some of the degrees-of-freedom quantum-mechanically and others classically. The computational and numerical characteristics of these methods are discussed, with emphasis on their particular advantages and relevance in the context of certain molecule/surface scattering problems. For the semiclassical and mixed quantal-classical treatments, the approximation errors and their physical origins are discussed. For the quantum wavepacket techniques a numerical error analysis is presented. The computational efficiency of the various algorithms is considered and examined in the context of several applications. The main focus is on ...

International Nuclear Information System (INIS)

Recently developed oxygen O18 method [K. Franzreb, J. Lorincik, P. Williams, Surf. Sci. 573 (2004) 291; R.C. Sobers, K. Franzreb, P. Williams, Appl. Surf. Sci. 231-232 (2004) 729; P. Williams, R.C. Sobers Jr., K. Franzreb, J. Lorincik, Appl. Surf. Sci. 252 (2006) 6429] is able to quantitatively determine the flux ratio of oxygen to matrix species at dynamical SIMS sputtering. This flux ratio can be directly related to the surface oxygen concentration at dynamical sputtering - an important parameter controlling the ionization yield of emitted species. It is argued that the oxygen O18 method is a worthy step forward in gathering relevant experimental data that might eventually lead to the understanding of oxygen enhancement mechanism in SIMS. A current status of understanding of the ionization processes in SIMS is briefly discussed in terms of non-adiabatic strongly velocity dependent processes represented by the electron ...

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A sensitive and rapid automated method has been developed for the selective analysis of acid extractable sulfide in environmental samples by combining gas dialysis separation techniques with methylene blue detection procedures. Acid extractable sulfide is separated from the sample matrix by the gas dialysis membrane and subsequently trapped in a dilute sodium hydroxide receiving stream. This stream is reacted with N,N-dimethyl-p-phenylenediamine and ferric chloride to produce methylene blue which is then quantitated colorimetrically at 660 nm. For standards and nonturbid environmental samples, there is good agreement between the results obtained by this procedure and the standard methylene blue method. The effect of interferences on the accurate determination of sulfide by both methods was also examined and it was found that cupric ions significantly interfered with sulfide estimation. To obtain ...

Science.gov (United States)

The purpose of this study was to use high-resolution magnetic resonance (MR) imaging combined with image analysis to investigate the three-dimensional (3D) trabecular structure, anisotropy, and connectivity of human vertebral, femoral, and calcaneal specimens. The goal was to determine whether: (a) MR-derived measures depict known skeletal-site-specific differences in architecture and orientation of trabeculae; (b) 3D architectural parameters combined with bone mineral density (BMD) improve the prediction of the elastic modulus using a fabric tensor formulation; (c) MR-derived 3D architectural parameters combined with BMD improve the prediction of strength using a multiple regression model, and whether these results corresponded to the results obtained using higher resolution depictions of trabecular architecture. A total of 94 specimens (12 x 12 x 12 mm cubes) consisting of trabecular bone only were obtained, of which there were 7 from the calcaneus, 15 from distal femur, 47 from the ...

International Nuclear Information System (INIS)

CT is the most accurate method to detect pulmonary emphysema in vivo. They compared prospectively two different methods for emphysema quantitation in 5 normal volunteers and 20 consecutive patients with chronic obstructive pulmonary disease (COPD). All subjects were submitted to function tests and HRCT; three scans were acquired at preselected levels during inspiration. The type and extent of pulmonary emphysema were defined by two independent observers under blind conditions. Disagreements were subsequently settled by consent. All subjects were also examined with expiratory spiral CT using a density mask program, at two different cut-off levels (-850,-900 HU). Visual score and expiratory spiral density mask values (-850 HU) were significantly correlated (r = 0.86), but the visual extent of emphysema was always higher than shown by expiratory spiral CT. The emphysema extent assessed with both CT methods ...

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The aim of this study was to evaluate the automated urine test strip analyzer Aution Max AX 4280 which uses strips able to measure 12 urinary parameters. For precision study, we considered glucose, protein, blood, leukocytes, nitrite, and pH and the four first were compared with usual methods: chemical measurement or microscopic examination. Reproducibility of the semi quantitative results was determined as the proportion of results falling into the same concentration range. Within-run reproducibility assessed using urine specimens were between 83% and 96%. Between day on quality controlled materials, it was higher (96%), and leukocytes were shared between two classes 250 and 500 cells/microL. For glucose and proteins, linearity was good and comparison with quantitative methods yielded high correlation. The false negative fraction was low and there was no false positive results. For blood, fraction of ...

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A new method for the separation and determination of trace amounts of cadmium and zinc in water as their thenoyltrifluoroacetone (TTA) complexes with dibenzo-18-crown-6 (DB18C6) in o-dichlorobenzene has been established by means of synergistic extraction and back-extraction combined with atomic absorption spectrometry. The effect of various factors (synergism with TTA and DB18C6, shaking time, composition of the extracted species, and mutual separation etc.) on the extraction and back-extraction of cadmium and zinc has been in- vestigated. When the mixtures were extracted for 4 min at pH 4.9, only zinc was extracted quantitatively, whereas cadmium remained in the aqueous phase. After the phases were separated, cadmium was again extracted quantitatively at pH 7.5. Then, the two phases were each shaken with 0.05-0.1 mol/l HCl in order to back-extract cadmium and zinc from the organic phases; the ions were determined ...

International Nuclear Information System (INIS)

In not infected knee prostheses bone scintigraphy is a possible method to diagnose mechanical loosening, and therefore, to affect treatment regimes in symptomatic patients. However, hitherto studies showed controversial results for the reliability of bone scintigraphy in diagnosing loosened knee prostheses by using asymptomatic control groups. Therefore, the aim of our study was to optimize the interpretation procedure and to evaluate the accuracy using results from revision surgery as standard. Methods: Retrospectively, we were able to examine the tibial component in 31 cemented prostheses. In this prostheses infection was excluded by histological or bacteriological examination during revision surgery. To quantify bone scintigraphy, we used medial and lateral tibial regions with a reference region from the contralateral femur. Results: to differentiate between loosened and intact prostheses we found a threshold of 5.0 for the maximum tibia to ...

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 ...

International Nuclear Information System (INIS)

A rapid and sensitive method for the separation and determination of titanium and iron in thiocyanate system has been developed. The extractability of Ti(II) by high molecular weight (HMWA) in organic solvent (HCl/sub 3/) and its separation from Fe(III) was examined. The yellow coloured complex of Ti(II)-SCN in quantitatively extracted into the organic phase containing tribenzyl tribenzylamine (TBA) - a high molecular weight amine, whereas the blood red coloured complex of Fe(III)-SCN formed under the same conditions get separated in the aqueous phase. On the basis of the selective extractability, a method has been developed for the separation as well as simultaneous determination of Ti(II) and Fe(III) in presence of many other elements. The molar extinction coefficients were found to be 1.9 x 10/sup 5/ l mol/sup -1/ cm/sup -1/ and 1.11 x 10/sup 5/ l mol/sup -1/ cm/sup -1/ respectively for Ti(II) and Fe(III). The ...

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.

International Nuclear Information System (INIS)

The Rocky Flats Environmental Technology Site (RFETS) has historically released radionuclide chemicals of potential concern into the surrounding environment. The off-site environment was evaluated for Pu"2"3"9"/"2"4"0 and Am"2"4"1 occurrence. An evaluation of exposure and effects to the aquatic ecology within off-site areas including: Standley Lake, Great Western Reservoir, Mower Reservoir and portions of Big Dry Creek, Walnut Creek, and Woman Creek was performed for the completion of an Ecological Risk Assessment. Collocated sampling activities were performed for surface water, sediment, benthic macroinvertebrates and fish. Results of the analytical data were used to assess ongoing exposure and effects. Data collected to determine effects (chemical content of fish tissue, diversity and density of macroinvertebrate populations) provided some of the necessary information needed to evaluate risk. However, due to conditions of interfering stressor effects, a ...

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This paper is a result of a research with the primary purpose of extending Probabilistic Risk Assessment (PRA) modeling frameworks to include the effects of organizational factors as the deeper, more fundamental causes of accidents and incidents. There have been significant improvements in the sophistication of quantitative methods of safety and risk assessment, but the progress on techniques most suitable for organizational safety risk frameworks has been limited. The focus of this paper is on the choice of 'representational schemes' and 'techniques.' A methodology for selecting appropriate candidate techniques and their integration in the form of a 'hybrid' approach is proposed. Then an example is given through an integration of System Dynamics (SD), Bayesian Belief Network (BBN), Event Sequence Diagram (ESD), and Fault Tree (FT) in order to demonstrate the feasibility and value of hybrid ...

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In order to clarify the alkali-resistance of fibers to be utilized as reinforcing materials for concrete, such as glass fiber, Aramid fiber, and carbon fiber, accelerated aging tests in alkaline solution were conducted. In detail, the degree of degradation of the fracture strength and Young's modulus were investigated through static tensile strength tests after soaking in alkaline solution of these fibers and then the mechanism of degradation was examined by observation using a scanning electron microscope. The conclusion obtained was as follows. Glass fiber was easily degraded in the alkaline solution and the progress of degradation was simulated quantitatively by the method proposed in this paper, which was based on a diffusion theory. Both Aramid fiber and carbon fiber showed a significant alkali-resistance without degrading. The reaction of glass fiber with alkaline solution proceeded uniformly from the surface of glass fiber into ...

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When the foundations of the building are designed and worked, the prediction calculation of immediate settlement of the building exercised practically is to calculate assuming the earth is a linear elastic body, but the actual stress-strain relationship of the earth is nonlinear and rigidity of the earth becomes lower as strain (or stress) increases. Hence in order to grasp the actual settling behavior of the earth, it is necessary to elucidate the nonlinear relationship between stress and strain. In this article, a prediction method of building settlement is introduced which uses an analytical technique of the multi-layered earth by the linear elasticity theory and takes into consideration strain dependency of rigidity of the earth. Part of the conclusion is as follows which has been obtained by studying the settling behaviors observed in examples of vertical loading tests of the pile foundations and the elasto-plastic settlement analytical ...

International Nuclear Information System (INIS)

The Compton backscatter technique has been applied to lap-joint in aircraft structure in order to determine mass loss due to exfoliative corrosion of the aluminum alloy sheet skin. The mass loss of each layer has been estimated from Compton backscatter A-scan including the aluminum sheet, the corrosion layer, and the sealant. A Compton backscattering imaging system has been also developed to obtain a cross-sectional profile of corroded lap-splices of aging aircraft using a specially designed slit-type camera. The camera is to focus on a small scattering volume inside the material from which the backscattered photons are collected by a collimated scintillator detector for interpretation of material characteristics. The cross section of the layered structure is scanned by moving the scattering volume through the thickness direction of the specimen. The theoretical model of the Compton scattering based on Boltzmann transport theory is presented for quantitative ...

Science.gov (United States)

A first-principles task-based approach to the design of medical ultrasonic imaging systems for breast lesion discrimination is described. This study explores a new approximation to the ideal Bayesian observer strategy that allows for object heterogeneity. The new method, called iterative Wiener filtering, is implemented using echo data simulations and a phantom study. We studied five lesion features closely associated with visual discrimination for clinical diagnosis. A series of human observer measurements for the same image data allowed us to quantitatively compare alternative beamforming strategies through measurements of visual discrimination efficiency. Employing the Smith-Wagner model observer, we were able to breakdown efficiency estimates and identify the processing stage at which performance losses occur. The methods were implemented using a commercial scanner and a cyst phantom to explore development of spatial ...

International Nuclear Information System (INIS)

A merged-beams electron-energy-loss technique is described, by which absolute cross sections can be measured for near-threshold electron-impact excitation of multipy charged ions. Results are reported here for absolute total electron-impact excitation cross sections for the O"5"+(2s#->#2p) transition from below threshold to 1.6 eV above threshold. The experimental data are in good agremeent with a seven-state close-coupling calculation throughout the energy range of the experiment. Results agree with calculations showing that more than 90% of the electrons causing excitation are ejected in the backward direction in the center-of-mass frame. This backscattering is shown in both quantum-mechanical and semiclassical calculations. Evidence is observed for high-lying metastable autoionizing states with a lifetime of approximately 0.9 #mu#s which are made to ionize by electron impact.

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A simple and specific method has been developed for the simultaneous determination of the four major Cinchona alkaloids and their dihydroderivatives and pyridoxine hydrochloride (Vitamin B_6) by high-performance liquid chromatography (HPLC) with fluorescence detection (#lambda#_e_m=420 nm with #lambda#_e_x=330 nm). The chromatographic separation was performed on a Phenomenex Prodigy ODS column (5 #mu#m, 250 mmx3.2 mm i.d.), recommended for basic compounds, under isocratic reversed-phase conditions. The method allowed a good peak shape and an effective resolution of the tested compounds. The extraction of alkaloids from the Cinchona succirubra bark was carried out in mild and fast conditions (ambient temperature, 20 min) by ultrasonication. The procedure showed to be advantageous respect to a reference method, which involved Soxhlet extraction. The results were compared statistically by means of the Student's t-test and the ...

International Nuclear Information System (INIS)

We present a sample preparation method for measuring magnesium in individual whole lymphocytes by electron probe X-ray microanalysis. We use Burkitt's lymphoma cells in culture as the test sample and compare X-ray microanalysis of individual cells with atomic absorption analysis of pooled cell populations. We determine the magnesium peak-to-local continuum X-ray intensity ratio by electron probe X-ray microanalysis and calculate a mean cell magnesium concentration of 39 +- 19 mmol/kg dry weight from analysis of 100 cells. We determine a mean cell magnesium concentration of 34 +- 4 mmol/kg dry weight by atomic absorption analysis of pooled cells in three cell cultures. The mean cell magnesium concentrations determined by the two methods are not significantly different. We find a 10% coefficient of variation for both methods of analysis and a 30% coefficient of variation in magnesium concentration among individual cells by ...

UK PubMed Central (United Kingdom)

Emphasis was put on the comparative quantitative structure-activity approaches to the exploration of action mechanisms of structurally different classes of compounds showing the same type of activity...Full Text Available

UK PubMed Central (United Kingdom)

A single radial hemolysis test was developed for quantitation of specific antibody to non-hemagglutinating viruses. With the human coronaviruses as models, this test utilizes the binding properties...Full Text Available

UK PubMed Central (United Kingdom)

Gene expression data has been used in lieu of phenotype in both classical and quantitative genetic settings. These two disciplines have separate approaches to measuring and interpreting epistasis, which...Full Text Available

International Nuclear Information System (INIS)

Positron emission tomography (PET) is a fully quantitative technology for imaging metabolic pathways and dynamic processes in vivo. Attenuation correction of raw PET data is a prerequisite for quantification and is typically based on separate transmission measurements. In PET/CT attenuation correction, however, is performed routinely based on the available CT transmission data. Recently, combined PET/magnetic resonance (MR) has been proposed as a viable alternative to PET/CT. Current concepts of PET/MRI do not include CT-like transmission sources and, therefore, alternative methods of PET attenuation correction must be found. This article reviews existing approaches to MR-based attenuation correction (MR-AC). Most groups have proposed MR-AC algorithms for brain PET studies and more recently also for torso PET/MR imaging. Most MR-AC strategies require the use of complementary MR and transmission images, or morphology templates generated from ...

International Nuclear Information System (INIS)

An attempt was made for early quantitative assessment of the severety of an injury, using the nuclear acids (NA) content as a biochemical indicator. Sexually mature male rats with body mass 160-180 g were irradiated with doses 0.5, 1, 2, 4 and 8 Gy of "1"3"7Cs source. Uneven irradiation was achieved by shielding the abdominal-lumbar area with lead rings, measuring 2,5/50 mm. A 28-30% fall of the dose beneath the shielded zone was thus provided. Dose-dependent quantitative changes in Na content were determined on hours 24 and 72 within the range from 0.5 to 8 Gy and followed up until day 30 after irradiation with nonlethal (2 Gy) and lethal (8 Gy) doses. The total NA content in the leucocytes was determined by the method of Kritski and Aleksandrov. The uneven irradiation of rats within the 0,5-8 Gy range induced early dose-dependent changes in NA content. The nature of their post-irradiation dynamics also depended on the ...

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New York City data indicate that seasonal and annual variations in dispersion-normalized air pollutant concentrations appear to accurately reflect changes in source emission patterns. The normalized concentrations make it possible to observe the impact of regulatory changes on ambient air quality without these impacts being obscured by meteorological fluctuations. It is found that numerical modeling techniques and regression analysis can be powerful tools for extracting information from large sets of air quality data. The use of differential, as opposed to absolute, pollutant concentration values will reduce artifact correlations caused by seasonal, weekly, or daily meteorological fluctuations and will permit more accurate estimation of the regression coefficients. This technique was successfully applied to a set of daily pollution measurements whose absolute concentrations were found not to yield a statistically significant fit by multiple ...

CERN Document Server

Using data from atmospheric neutrino mixing, and a simple functional form for mixing angles, the absolute values of three neutrino masses are calculated: $m_3\\cong 5.37\\times 10^{-2} eV$, $m_2\\cong 1.94\\times 10^{-2} eV$, $m_1\\cong 1.46\\times 10^{-2} eV$. The quantities relevant for solar neutrino mixing are calculated: $(m_2^2-m_1^2) \\cong 1.63\\times 10^{-4} eV^2$, with non-maximal mixing $\\tan^2\\theta_\\sol \\cong 0.56$. The analysis gives a suggestion of a dynamical origin for the empirical, large CP-violating phase associated with an intrinsically, very small mixing angle in the quark sector.

International Nuclear Information System (INIS)

Absolute total cross sections for electron-impact excitation of the 3s"2"1S#->#3s3p"3P and 3s"2"1S#->#3s3p"1P transitions in Si"2"+ were measured using the merged electron-ion beams energy-loss technique. The results are compared to R-matrix close-coupling theory, which predicts a strong resonance enhancement of the cross section near the threshold for excitation of the "3P state and this is confirmed by the experiments. The observed disagreement between theory and experiment for the dipole excitation is suggested to be due to resonance interference. copyright 1997 The American Physical Society.

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1986. p. 390-392. Germany Brecht-Krauss, D. Kusmierek, J. Adam, WE Ulm

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International Nuclear Information System (INIS)

The suggestion has often been made that an additional radiation exposure imposed on humanity as a result of some important activity such as electricity generation would be acceptable if the exposure was 'small' compared to the natural background. In order to make this concept quantitative and objective, we propose that 'small compared with the natural background' be interpreted as the standard deviation (weighted with the exposed population) of the natural background. We believe that this use of the variation in natural background radiation is less arbitrary and requires fewer unfounded assumptions than some current approaches to standard-setting. The standard deviation is an easily calculated statistic that is small compared with the mean value for natural exposures of populations. It is an objectively determined quantity and its significance is generally understood. Its determination does not omit any of the pertinent data. When this method ...

Energy Technology Data Exchange (ETDEWEB)

Described herein are the results of the FY1994 research program for analysis and evaluation for thin film solar cells. The study on quantitative analysis of hydrogen atoms in a plasma determines quantity of hydrogen atoms in the plasma of monosilane diluted with hydrogen. It is found, contrary to expectation, that quantity of hydrogen atoms in the plasma decreases as it is more diluted with hydrogen. The study on light-induced degradation of the thin chlorine-base amorphous silicon films confirms that the plasma CVD method with 20% of dichlorosilane gas added to monosilane gas produces the thin amorphous silicon film 3 times faster than the conventional method. The thin film has essentially the same defect density as the one prepared by the conventional method, showing good photoelectric characteristics. The thin film of chlorinated amorphous silicon has a 1 digit lower defect density than the ...

Energy Technology Data Exchange (ETDEWEB)

The influence of high temperature thermal ageing treatments on the development of intercrystalline creep damage in two variants of Alloy 800 has been investigated. Ageing up to 3000 h and creep testing were carried out at 800 and 900 C. The high temperature behaviour of the 800HT variant is discussed with reference to the effect of heat treatments on the microstructure. The metallographic methods by which the creep damage was quantitatively determined are described. The growth rate of intercrystalline microcracks was described using a statistical model and the dependence of crack growth rate on the thermal history for both 800HT and 800H was determined. The carbide precipitation and growth processes were determined as functions of the exposure temperature and duration. The results showed the three characteristic stages, precipitation, growth and coarsening (Ostwald ripening). The largest increase in the intergranular creep damage was found in ...

International Nuclear Information System (INIS)

A calculation program (URA 6.F4) was elaborated on FORTRAN IV language, that through finite differences solves the unidimensional scalar Helmholtz equation, assuming only one energy group, in spherical cylindrical or plane geometry. The purpose is the determination of the flow distribution in a reactor of spherical cylindrical or plane geometry and the critical dimensions. Feeding as entrance datas to the program the geometry, diffusion coefficients and macroscopic transversals cross sections of absorption and fission for each region. The differential diffusion equation is converted with its boundary conditions, to one system of homogeneous algebraic linear equations using the box integration technique. The investigation on criticality is converted then in a succession of eigenvalue problems for the critical eigenvalue. In general, only is necessary to solve the first eigenvalue and its corresponding eigenvector, employing the power method. The obtained results by ...

International Nuclear Information System (INIS)

Purpose: In an experimental study, the correlation between the trabecular bone density of the different regions of the proximal femur and the fracture load in the setting of femoral neck fractures was examined. Methods: The bone mineral density 41 random proximal human femora was estimated by single-energy quanitative CT (SE-QCT). The trabecular bone density was measured at the greatest possible extracortical volume at midcapital, midneck and intertrochanteric level and in the 1 cm"3 volumes of the centres of these regions in a standardised 10 mm thick slice in the middle of the femoral neck axis (in mg/ml Ca-hydroxyl apatite). The proximal femora were then isolated and mounted on a compression/bending device under two-legged stand conditions and loaded up to the point when a femoral neck fracture occurred. Results: Statistical analysis revealed a linear correlation between the trabecular bone density and the fracture load for the greater regions, with the highest ...

Energy Technology Data Exchange (ETDEWEB)

Qualitative and quantitative methods have been developed to relate phosphate/UO{sub 2} interactions and U dissolution, in vitro, in a medium containing 0 or 10 mM phosphate concentrations at pH 5. This was performed by Energy Dispersive X ray Spectrometry (EDS) at 200 kV on entire particles and by fluorimetric measurement. The U dissolution rate was larger in a medium without phosphate than in a medium containing 10 mM phosphate. During the first day, the initial U dissolution involved 80.55% and 91.13% of the powder in media with and without phosphate respectively. From 5 to 15 d after beginning the assay, the dissolution half-times were longer than 92 d and 22 d for media with and without phosphate. EDS analyses have shown a constant P/U X ray intensity ratio for reference U{sub 2}O(PO{sub 4}){sub 2} for the same range of particle diameter. A gradual increase of this ratio was measured for UO{sub 2} incubated in a 10 mM phosphate medium ...

International Nuclear Information System (INIS)

The study of natural convection flow and heat transfer within a cylindrical annulus has received considerable attention because of its numerous applications, such as in nuclear reactor design, electronic component cooling, thermal storage systems, energy conservation, energy storage, and energy transmission. Here, the effects of multiple geometric perturbations on the inner and outer cylinders of an annulus with impermeable end walls are investigated in this work. A three-dimensional study was done using a numerical scheme based on a Galerkin method of finite element formulation. The nature of the buoyancy-induced flow field has been analyzed in detail. The flow fields for the cases considered were found to be qualitatively similar, and the introduction of each additional perturbation altered the flow field in a regular and recurring manner. The introduction of each perturbation on the outer cylinder causes clockwise and counterclock-wise rotating patterns on ...

International Nuclear Information System (INIS)

As with science, so with security--in both arenas, the extraordinary sensitivity of cryogenic sensors enables high-confidence detection and high-precision measurement even of the faintest signals. Science applications are more mature, but several national and international security applications have been identified where cryogenic detectors have high potential payoff. International safeguards and nuclear forensics are areas needing new technology and methods to boost speed, sensitivity, precision and accuracy. Successfully applied, improved nuclear materials analysis will help constrain nuclear materials diversion pathways and contribute to treaty verification. Cryogenic microcalorimeter detectors for X-ray, gamma-ray, neutron, and alpha-particle spectrometry are under development with these aims in mind. In each case the unsurpassed energy resolution of microcalorimeters reveals previously invisible spectral features of nuclear materials. Preliminary results of ...

International Nuclear Information System (INIS)

In this work trailing edge noise levels of a research aerofoil have been computed and compared to aeroacoustic measurements using two different approaches. On the other hand, aerodynamic and aeroacoustic calculations were performed with the full Navier-Stokes CFD code Fluent [Fluent Inc 2005 Fluent 6.2 Users Guide, Lebanon, NH, USA] on the basis of a steady RANS simulation. Aerodynamic characteristics were computed by the aid of various turbulence models. By the combined usage of implemented broadband noise source models, it was tried to isolate and determine the trailing edge noise level. Throughout this work two methods of different computational cost have been tested and quantitative and qualitative results obtained. On the one hand, the semi-empirical noise prediction tool NAFNoise [Moriarty P 2005 NAFNoise User's Guide. Golden, Colorado, July. http://wind.nrel.gov/designcodes/ simulators/NAFNoise] was used to directly predict trailing edge ...

Energy Technology Data Exchange (ETDEWEB)

In the present paper, the chemical composition of passive films formed on both phases of two types of duplex stainless steels (UNS S31803 and UNS S32304) is determined at the micro-scale using Auger electron spectroscopy (AES). Samples were either mechanically polished (down to diamond pastes) or electrochemically etched in acidic solutions. The micro-electrochemical behavior of samples was then determined in sodium chloride media by means of the electrochemical micro-cell technique (capillary diameters of 30 {mu}m). The results obtained were analyzed considering the passive film chemical composition. Quantitative relationships between electrochemical parameters and the distribution of chromium and iron in the oxide layer were found. Due to differences in mechanical properties between ferrite and austenite, a heterogeneous stress distribution is generated in both phases. A method based on thermal-mechanical simulation was used to quantify ...

Energy Technology Data Exchange (ETDEWEB)

Silicon nitride based ceramics have attracted considerable attention as good candidates for structural applications due to their excellent mechanical properties including strength, hardness, fracture toughness, and high temperature strength. These properties are strongly influenced by grain size and morphology, and by the degree of crystallinity and chemistry of grain boundary phases. In this work, the microstructure of Si{sub 3}N{sub 4} densified with Nd{sub 2}O{sub 3}, Y{sub 2}O{sub 3} and Al{sub 2}O{sub 3} sintering additives was studied. Sintered samples were polished and plasma etched for microstructural analysis using scanning electron microscope. Quantitative evaluation of materials microstructure was accomplished using Quantikov software. Fracture toughness was measured by Vickers indentation method. The observed microstructure is typical of silicon nitride based materials and is characterized by high aspect ratio.-Si{sub 3}N{sub 4} ...

Energy Technology Data Exchange (ETDEWEB)

Hepatobiliary scintigraphy is the only non-invasive technique providing real-time assessment of hepatocytes function and bile progression from the liver to the intestine; for this reason it is of great importance in the study of jaundice and many other disorders of the liver and the biliary tract in children. Ultrasonography is the initial method of evaluating the intra- and extrahepatic bile ducts dilatation: the differential diagnosis between biliary atresia and neonatal hepatitis cannot however be done without hepatobiliary scintigraphy. Cystic fibrosis patients also require hepatobiliary scintigraphy; liver and biliary tract disease can really occur independently of the underlying disease severity and the presence of steatorrhoea. Hepatobiliary imaging in children who have undergone liver transplantation is of major importance; it can assess vascularity, parenchymal function biliary drainage, possible presence of a bile leak and obstruction; it has very good ...

International Nuclear Information System (INIS)

We investigated the isotropic diffusion coefficient (D') and fractional anisotropy (FA) in white matter (WM) during brain development, using an optimised diffusion-tensor imaging (DTI) method with whole brain coverage in a clinically acceptable time. We images 52 children with no evident neurological abnormality (30 boys, 22 girls aged 1 day-16 years) using high-angle DTI with optimised temporal gradient performance. D' and FA were calculated in 10 regions of interest in white matter. We saw that the age-related reduction in D' and increase in FA follow a mono- or biexponential model in white matter, probably depending on the compactness and myelination rate of the fibre tracts. In contrast to other areas, in which adult values were reached during the third year, there is a trend to continuous increase in FA in all deep white-matter areas, suggesting continuing maturation and organisation of deep tracts not detected on conventional MRI. (orig.)

Energy Technology Data Exchange (ETDEWEB)

Gene analysis was used to determined the presence, abundance and phylogenetic affiliation of methanogens that exist in gas-hydrate-bearing sediment samples obtained from 23 drill cores from the JAPEX/JNOC/GSC et al. Mallik 5L-38 gas hydrate research well. Rates of methane production were examined using sediment-inoculated enrichments containing {sup 14}C-labeled carbon substrates, carbon dioxide and acetate. Archaeal 16S rDNA was only detected in 6 of the samples, resulting in 8 sequences with relationships to the Miscellaneous Crenarchaeotic Group (7 clones) and the Subsurface Euryarchaeotic Group (1 clone). The single Euryarchaeota sequence did not appear to be related to methanogens. Subsamples from the cores showed variable results upon DNA extraction and amplification. Methanogenic Coenzyme M (CoM) was detected in 13 of the 20 cores, but methanogenic methyl CoM reductase genes were not amplified from the samples when using a sensitive quantitative polymerase ...

Energy Technology Data Exchange (ETDEWEB)

Sterile aqueous N-methylaniline solutions were allowed to equilibrate at various nitrite, F-400 granular-activated carbon, and pH levels for 1 week. The aqueous and activated carbon phases were extracted and analyzed for nitrosamines relative to an added internal standard. Selected ion monitoring GC/MS, utilizing continuous monitoring of the NO/sup +/ ion (m/z 29.9980) characteristic of nitrosamines, at medium resolution (R = 2500-3000) was applied to quantitatively measure nitrosamines at picograms per microliter concentrations. This method selected for nitrosamine products only and eliminated interferences from non-nitrosamine reaction products. Results indicate that the pressure of granular-activated carbon significantly enhanced the formation of nitrosamine from N-methyl-aniline (F = 145, P< 0.0001). The amount of N-nitrosomethylaniline formed in the presence of activated carbon was 75 times more than that formed in the absence of ...

Science.gov (United States)

We report on the contents and results for 360 students of a mathematics assessment administered at the start of the second-semester introductory chemistry course required for science and engineering majors at the University of Minnesota. This calculator-free, 20-question, 30-minute, multiple-choice, diagnostic quiz includes questions selected specifically for their relevance to this course, concerning logarithms, scientific notation, graphs, and algebra. For the 325 students in degree-granting programs, significant correlations are reported between their mathematics assessment scores and success in this course, as measured by performance on exams (for which scientific calculators were permitted) and course grades. These observations suggest that responses to the simple questions on this unannounced quiz have some predictive utility as signatures of underlying thinking and learning patterns that are associated with success in this course. In addition, we argue that these results ...

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 ...

International Nuclear Information System (INIS)

For good image quality using ultrasound inverse scattering, one alternately solves the well-posed forward scattering equation for an estimated total field and the ill-posed inverse scattering equation for the desired object property function. In estimating the total field, error or noise contaminates the coefficients of both matrix and data of the inverse scattering equation. Previous work on ill-posed inverse ultrasonic scattering commonly used Tikhonov regularization, which considers error only in the data. The solution so obtained is not precise enough to reconstruct the quantitative internal structure of a large or high-contrast object. This paper adopts the truncated total least squares method, simultaneously considering error and noise on both sides of the inverse scattering equation, and compares it with the classical Tikhonov regularization. We show that it can substantially improve reconstruction fit and image quality when the inverse ...

Energy Technology Data Exchange (ETDEWEB)

It is shown that the existence of faster-than-light signals (tachyons) would imply the existence (and detectability) of a privileged inertial frame and that one can avoid all problems with reversed-time order only by using absolute synchronization instead of the standard one. The connection between these results and the EPR-paradox is discussed.

CERN Multimedia

Joanna Geary joined a Birmingham University team of scientists working on the project in Geneva. Simond Hadley took the pictures. "The most exciting thing of all" says professor Peter Watkins with a smile, "is we have absolutely no idea what will happen until we switch it on."

Science.gov (United States)

Previous investigations have shown that both the early biological response and the mechanical properties of a porous hydroxyapatite bone graft substitute are highly sensitive to its pore structure. The objective of this study was to evaluate whether the pore structure continued to influence bone integration in the medium to long term. Two screened batches of porous hydroxyapatite (PHA) designated as batch A and batch B, with porosities of approximately 60 and 80%, respectively, were selected for this study and implanted for periods of 5, 13, and 26 weeks into the lower femur of New Zealand White rabbits. Histomorphometric analysis of the absolute volume of bone ingrowth within batch A and B implants from 5 to 26 weeks showed that the absolute volume of bone ingrowth was consistently lower in batch A (10-21%), compared to batch B implants (24-31%). However, when the volume of bone ingrowth was normalised for the available pore space, this ...

CERN Document Server

Families of regimes for discrete control systems are studied possessing a special quasi-controllability property that is similar to the Kalman controllability property. A new approach is proposed to estimate the amplitudes of transient regimes in quasi-controllable systems. Its essence is in obtaining of constructive a priori bounds for degree of overshooting in terms of the quasi-controllability measure. The results are applicable for analysis of transients, classical absolute stability problem and, especially, for stability problem for desynchronized (asynchronous, switching) systems.

Science.gov (United States)

The paper investigates the controversial relation between the continuum luminosity and the C IV 1550 emission-line strength in the spectra of quasars, commonly referred to as the Baldwin effect, as a possible indicator of absolute luminosity. It is concluded that the Baldwin effect does represent a physical correlation between the continuum and the C IV 1550 equivalent width rather than a consequence of selection effects. In addition to the C IV results, a similar relation is found for the Lyman-alpha emission line. 38 refs.

Science.gov (United States)

On-orbit spectral calibration of hyperspectral imaging data is a key step for quantitatively analyzing them. Like the atmospheric correction, accurate spectral calibration is very necessary for improved studies of land or ocean surface properties. Based on the previous literatures, a new method which coupled an optimization algorithm was developed to simultaneously retrieve the central wavelength and the full width at half maximum (FWHM) of the hyperspectral sensor without needing the in situ reflectance spectra. Firstly, the Hyperion data set simulated using MODTRAN4 with the Hyperion spectral specification was used to test the new method, and the results indicated that the maximum error was less than 0.1 and 0.7 nm for central wavelength and FWHM respectively when the spectral shift is 5 nm. Then the algorithm was applied to the Hyperion data acquired on May 20, 2008 over Heihe River Basin and it was iteratively performed ...

Energy Technology Data Exchange (ETDEWEB)

Part I of this thesis is on long-term iceberg collision-risk assessment methods for fixed offshore structures. Estimates for the long-term probability that an iceberg will hit a fixed offshore structure are based on estimates of the total volume of produced iceberg, a model for the size distribution of icebergs and a description of how iceberg trajectories ``fill`` the plane (the ocean`s surface). Part II of the thesis discusses methods for analysis of low resolution data in the sense that the size of the area covered by each pixel is not small compared to the dominating floes. Still, this type of data can provide estimates of the ice extent (and hence the ice edge) and ice concentration. The estimates of the ice edge (at least) seem to be physically significant in the sense that ``in some way`` they can reflect ice drift in an image time sequence. A priori this is far from obvious. A central idea is that the ``ice edge`` is close to a ...

Energy Technology Data Exchange (ETDEWEB)

The hydroelectric industry's recognition of the importance of avoiding unexpected failure, or forced outages, led to the development of probabilistic, or risk-based, methods in order to attempt to quantify exposures. Traditionally, such analysis has been carried out by qualitative assessments, relying on experience and sound engineering judgment to determine the optimum time to maintain, repair or replace a part or system. Depending on the nature of the problem, however, and the level of experience of those included in the decision making process, it is difficult to find a balance between acting proactively and accepting some amount of risk. The development of a practical means for establishing the probability of failure of any part or system, based on the determination of the statistical distribution of engineering properties such as acting stresses, is discussed. The capacity-demand analysis methodology, coupled with probablistic, risk-based analysis, ...

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 coefficient, it also ...

Science.gov (United States)

... These assumptions are quantitatively investigated by calculating tie icldti\\e inportance of ... A modified lon-shore current model is used to study the ...

UK PubMed Central (United Kingdom)

A specific application of single photon emission tomography to the relative quantitation of the pituitary region is described together with the results obtained in 19 patients with pituitary adenoma...Full Text Available

Science.gov (United States)

Typing Workshop": [Introductions] [Intro, DNA Basics, and Historical Perspective] [DNA Extraction] [Validation and QA/QC] [DNA Quantitation] [PCR Amplification] [STR Loci and Kits]...

Science.gov (United States)

This laboratory exercise demonstrates some basic principles in parasitology by using experimental studies of the relationship of Hymenolepis diminuta with its rodent host.

Science.gov (United States)

... and high-quality photospheric-phase Type II SN spectra to constrain core- collapse SN explosions, massive star evolution, and distances in the Universe ...