Energy Technology Data Exchange (ETDEWEB)
The purpose was to compare the findings of multi-detector computed tomography (MDCT) in prosthetic valve disorders using the operative findings as a gold standard. In a 3-year period, we prospectively enrolled 25 patients with 31 prosthetic heart valves. MDCT and transthoracic echocardiography (TTE) were done to evaluate pannus formation, prosthetic valve dysfunction, suture loosening (paravalvular leak) and pseudoaneurysm formation. Patients indicated for surgery received an operation within 1 week. The MDCT findings were compared with the operative findings. One patient with a Bjoerk-Shiley valve could not be evaluated by MDCT due to a severe beam-hardening artifact; thus, the exclusion rate for MDCT was 3.2% (1/31). Prosthetic valve disorders were suspected in 12 patients by either MDCT or TTE. Six patients received ...
2009-04-15
International Nuclear Information System (INIS)
Background: High-resolution computed tomography is the image procedure of choice in the evaluation of interstitial lung disease. Multidetector-row computed tomography provides the possibility of simultaneous reconstruction of thin and thick slices from the same raw data, acquired from one single series. Thus, it may be tempting to exclude the step-and-shoot series. Purpose: To compare high-resolution computed tomography (HRCT step-and-shoot) from single-slice CT (SSCT) and 16-channel multidetector CT (MDCT) in terms of visibility and motion artifacts, and to investigate whether thin images reconstructed from helical MDCT are equal to or better than conventional HRCT by SSCT in terms of visibility and motion artifacts. Material and Methods: 20 patients underwent HRCT step-and-shoot by SSCT (SSCT step-and-shoot) and MDCT (MDCT step-and-shoot), and a helical MDCT ...
2007-11-01
International Nuclear Information System (INIS)
Our aim was to investigate the diagnostic reliability of multidetector-row computed tomography (MDCT) for preoperative assessment of local tumoral spread in hilar cholangiocarcinoma. Thirteen of 30 consecutive patients with hilar cholangiocarcinoma who underwent surgery, excluding 17 patients who underwent biliary drainage or preoperative portal embolization, were retrospectively evaluated. Using MDCT systems of 4 detector rows or 16 detector rows, plain and dynamic contrast-enhanced images of three phases were obtained. Extent of tumor spread and lymph node metastasis were assessed with MDCT and compared with histopathological findings. The Bismuth-Corlette classification of hilar cholangiocarcinoma with MDCT were type I, 1 patient; type IIIa, 3 patients; type IIIb, 4 patients; and type IV, 5 patients; those with histopathological findings were type I, 1 patient; type IIIa, 2 ...
2008-08-01
British Library Electronic Table of Contents (United Kingdom)
Purpose Video-assisted thoracic surgery (VATS) has recently been adopted for complicated anatomical lung resections. During these thoracoscopic procedures, surgeons view the operative field on a two-dimensional (2-D) video monitor and cannot palpate the organ directly, thus frequently encountering anatomical difficulties. This study aimed to estimate the usefulness of preoperative three-dimensional (3-D) imaging of thoracic organs. Methods We compared the preoperative 64-row three-dimensional multidetector computed tomography (3DMDCT) findings of lung cancer-affected thoracic organs to the operative findings. Results In comparison to the operative findings, the branches of pulmonary arteries, veins, and bronchi were well defined in the 3D-MDCT images of 27 patients. Conclusion 3D-MDCT imag...
2009-01-01
International Nuclear Information System (INIS)
The aim of this study was to compare multidetector-row computed tomography (MDCT) findings between cases of sclerosing cholangitis with autoimmune pancreatitis (SC-AIP) and infiltrative extrahepatic cholangiocarcinoma (IEC). We retrospectively assessed MDCT findings from 16 IEC cases and 13 SC-AIP cases. MDCT findings were analyzed with regard to location, length, wall thickness, contour, stricture wall enhancement pattern, proximal duct diameter, and the presence of diffuse concentric thickening in the proximal duct and gallbladder wall thickness. Stricture length, stricture wall thickness, and proximal duct diameter were significantly smaller for SC-AIP than for IEC: 19.3#+-#8.7 vs. 31.8#+-#12.0 mm (P=0.004), 2.1#+-#1.3 vs. 4.1#+-#1.3 mm (P<0.001), and 9.2#+-#3.9 vs. 13.3#+-#5.0 mm (P=0.012), respectively. SC-AIP was correlated with stricture location in both the intrapancreatic and hilar hepatic ...
2010-04-01
What is the best contrast injection protocol for 64-row multi-detector cardiac computed tomography?
International Nuclear Information System (INIS)
Objective: To determine the optimal contrast injection protocol for 64-MDCT coronary angiography. Materials and methods: One hundred and fifty consecutive patients scheduled to undergo retrospectively electrocardiographically gated 64-MDCT. Each 30 patients were assigned to use a different contrast protocol: group 1: uniphasic protocol (contrast injection without saline flush); group 2: biphasic protocol (contrast injection with saline flush); group 3A, 3B and 3C: triphasic protocol (contrast media + different saline diluted contrast media + saline flush). Image quality scores and artifacts were compared and evaluated on both transaxial and three-dimensional coronary artery images among each contrast protocol. Results: Among the triphasic protocol groups, group 3A (30%:70% contrast media-saline mixture was used in second phase) used the least contrast media and had the least frequency of streak artifacts, but there were no ...
2010-08-01
Multidetector-row helical CT: analysis of time management and workflow
International Nuclear Information System (INIS)
The purpose of this study was to evaluate time management and workflow for multidetector-row helical CT (MDCT). Time for patient and data handling of at total of 580 patients were evaluated at two different time periods (December 1999, August 2000), each for the following baseline measurements: (a) change of clothes/instruction; (b) patient placement on the CT table/i.v. catheter; (c) CT planning and programming; (d) CT data acquisition; (e) CT data reconstruction; (f) CT data storage/printing. All imaging was performed on a Somatom Volume Zoom (Siemens, Erlangen, Germany). Time measurements summarized for different CT protocols revealed the following: (a) 5:01 min (#+-#2.06 min); (b) 4:36 min (#+-#2.43 min); (c) 4:11 min (#+-#2.55 min); (d) 0:43 min (#+-#0.15 min); (e) 6:59 min (#+-#2.39 min); (f) 09:51 min (#+-#3.51 min). Planning and programming was most time-consuming for CT angiography, whereas chest and abdominal CT needed only 3:26 and 3:30 min, ...
2002-03-01
Dual energy virtual CT colonoscopy with dual source computed tomography. Initial experience
International Nuclear Information System (INIS)
Purpose: To describe the technique of DE MDCT colonoscopy and to assess its feasibility. Materials and Methods: 8 patients were scanned with DSCT with a DE scan protocol and dose modulation software. Analysis was performed using dedicated DE software. Prone non-contrast images and DE supine images after contrast injection were obtained. Results: DE colonoscopic images were successfully obtained in 7 patients, but the FOV did not cover all colonic segments in 1 patient, thus resulting in a technical success rate was 87.5%. Streak artifacts were present in the pelvic region in 2 patients. Virtual unenhanced images and iodine map images were obtained for all patients. In 1 patient a polypoid non-enhancing structure was noted on the iodine map, and conventional colonoscopy revealed impacted stool. Enhancing rectal cancer in 1 patient was correctly shown on the iodine map. Iodine maps helped to differentiate stool fragments/retained fluid by the absence of enhancement ...
2009-09-01
64-slice multidetector coronary CT angiography: in vitro evaluation of 68 different stents
Energy Technology Data Exchange (ETDEWEB)
The purpose of this study was to test a large sample of different coronary artery stents using four image reconstruction approaches with respect to lumen visualization, lumen attenuation, and image noise in 64-slice multidetector-row computed tomography (MDCT) in vitro and to provide a catalogue of currently used coronary artery stents when imaged with state-of the-art MDCT. We examined 68 different coronary artery stents (57 stainless steel, four cobalt-chromium, one cobalt-alloy, two nitinol, four tantalum) in a coronary artery phantom (vessel diameter 3 mm, intravascular attenuation 250 HU, extravascular density -70). Stents were imaged in axial orientation with standard parameters: 32x0.6 collimation, pitch 0.24, 680 mAs, 120 kV, rotation time 0.37 s. Four different image reconstructions were obtained with varying convolution kernels and section thicknesses: (1) soft, 0.6 mm, (2) soft, 0.75, (3) medium soft, 0.6, and (4) stent-optimized ...
2006-04-15
Diagnosis for the cancer extension of cholangiocarcinoma. The current status
International Nuclear Information System (INIS)
Described is the diagnosis for the cancer extension of cholangiocarcinoma by various imaging techniques and processes to support the current surgical procedure based on preoperative biliary drainage. The cancer tends to locally extend horizontally and/or vertically and its diagnosis is important for surgical indication. For the indication, multi-detector raw CT (MDCT) and MR cholangio-pancreatography (MRCP) are useful and particularly, the former can give multi-phase (arterial, portal and delayed) images to reconstruct multiplanar (MPR) and CT angiographic 3D images, which have made the previous invasive examinations like angiography and percutaneous transportal contrasting unnecessary. MDCT and MRCP can almost complete the diagnosis of the extension. The operative procedure is decided dependently on the site of the lesion, and of which diagnosis, whether it is hepatic hilar/on upper bile duct or middle/lower ductal, is different. ...
2010-07-01
Multidetector Computed Tomography in the Preoperative Workup of Hilar Cholangiocarcinoma
International Nuclear Information System (INIS)
Hilar cholangiocarcinoma is associated with a dismal prognosis; however, curative resection may offer a chance of cure. Various factors should be considered in the surgical planning for curative resection. These factors include extent of bile duct involvement, relationship between portal vein and tumor involvement, diffuse hepato duodenal ligament infiltration, vascular invasion, lymph node metastasis, peritoneal seeding, and hepatic volume. Using high-quality volume data from multidetector-row computed tomography (MDCT) and adequate postprocessing images, radiologists can provide various types of information, imperative for curative resection of a hilar cholangiocarcinoma. This review illustrates the role of MDCT in the preoperative workup of hilar cholangiocarcinoma.
2009-10-01
International Nuclear Information System (INIS)
Herein we present an impact of diagnosis by enhanced multidetector-row computed tomography and magnetic resonance imaging for extrahepatic cholangiocarcinoma (ECC). Although the diagnosis against the longitudinal stromal extension and surrounding tissue invasion of ECC by multi detector row CT (MDCT) and MRI was very strict, we could not detect any superficial mucosal spread (SMS). Furthermore, the diagnosis of lymphnode metastasis by MDCT/MRI was miserable. We believe that misdiagnosis of SMS is permissible since positive mucosal but not stromal surgical margin was not a significant factor influencing the postoperative prognosis. However, further advances in imaging diagnosis for ECC is needed. (author)
2009-10-01
Magnetic resonance imaging in childhood epilepsy
International Nuclear Information System (INIS)
The suitability of MR imaging versus computerized tomography in observation of brain development disorders in children are compared. 13 refs.
International Nuclear Information System (INIS)
Accurate diagnosis of local invasion of hilar cholangiocarcinomas is challenging due to their small size and the anatomic complexity of the hepatic hilar region. On the other hand, the correct diagnosis of local invasion is essential for assuring the possibility of curative surgery. The purpose of this study was to evaluate the feasibility of four-channel multidetector-row computed tomography (MDCT) in the assessment of vascular and bile duct involvement, by which we could obtain useful information for the surgical management of hilar cholangiocarcinoma. The subjects were 18 patients for whom the extent of tumor invasion was surgically and pathologically confirmed. All patients underwent preoperative multiphasic CT scanning by MDCT. Arterial and portal dominant phases were acquired using a detector configuration of 1.25 mm x 4 mm, and both axial and multiplanar reconstructed images were interpreted. Longitudinal extension was evaluated up to ...
2009-01-01
UK PubMed Central (United Kingdom)
In this observational study, we compared erythrocyte membrane fatty acids in infants consuming formula supplemented with docosahexaenoic acid (DHA) and arachidonic acid (ARA) with those consuming...Full Text Available
2010-10-01
Epidemiological survey of the effects of low level radiation dose: a comparative assessment
Energy Technology Data Exchange (ETDEWEB)
This volume presents the collations tables of a six volume comparative epidemiological survey of the effects of low level radiation dose. Data are collated for the effects observed in the following irradiated groups:- Preconception irradiation, intra-uterine irradiation, childhood irradiation, adult irradiation. (UK).
1993-10-01
International Nuclear Information System (INIS)
Purpose. To validate a protocol for creating virtual models to be used in the construction of solid prototypes useful for the planning-simulation of maxillo-facial surgery, in particular for very complex anatomical and pathologic problems. To optimize communications between the radiology, engineering and surgical laboratories. Methods and materials. We studied 16 patients with different clinical problems of the maxillo-facial district. Exams were performed with multidetector computed tomography (MDCT) and single slice computed tomography (SDCT) with axial scans and collimation of 0.5-2 mm, and reconstruction interval of 1 mm. Subsequently we performed 2D multiplanar reconstructions and 3D volume-rendering reconstructions. We exported the DICOM images to the engineering laboratory, to recognize and isolate the bony structures by software. With these data the solid prototypes were generated using stereolitography. To date, surgery has been preformed on 12 patients ...
2005-11-01
Oxygen intake in track and treadmill running with observations on the effect of air resistance
UK PubMed Central (United Kingdom)
1. The relation of V̇O2 and speed was measured on seven athletes running on a cinder track and an all-weather track. The results were compared...Full Text Available
1970-05-01
UK PubMed Central (United Kingdom)
A detailed comparative assessment was made of the use of solid-phase-coupled antibodies in radioimmunoassay, by using an assay for human placental lactogen as a model system. The major advantages of...Full Text Available
1974-03-01
UK PubMed Central (United Kingdom)
BackgroundObservational clinical studies have shown that patients with diabetes have less favorable results after percutaneous coronary intervention compared with the non-diabetic...Full Text Available
Endurance time is joint-specific: A modelling and meta-analysis investigation
UK PubMed Central (United Kingdom)
Static task intensity–endurance time (ET) relationships (e.g. Rohmert's curve) were first reported decades ago. However, a comprehensive meta-analysis to compare experimentally-observed...Full Text Available
2010-01-01
Suppression of the transverse scattering amplitude in /sup 207/Pb
Energy Technology Data Exchange (ETDEWEB)
Transverse form factors have been extracted for the low-lying neutron hole (particle) states of /sup 207/Pb from inelastic-electron-scattering data. A systematic, multipolarity-and momentum-transfer-independent quenching of approx.55% in the transverse amplitude is observed when compared with single particle predictions for both electric and magnetic transitions. The magnitude of the observed effect is not readily explained by our present theoretical understanding of this nucleus.
1980-07-14
International Nuclear Information System (INIS)
A Lagrangian atmospheric dispersion model(K-LADM) combining a three dimensional sea-land breeze model has been developed and applied to the estimation of the quaterly and the annual averaged air tritium concentration around Wolsung NPP site. The estimated concentrations were compared with the observed concentration data. The results showed that the present Lagrangian Atmospheric dispersion model(K-LADM) provided very good agreement with the observations.
1998-10-01
New coumarin-based sensor molecule for magnesium and calcium ions
British Library Electronic Table of Contents (United Kingdom)
A new coumarin-based sensor molecule (L1) has been synthesized and this was found to bind calcium and magnesium ions more effectively as compared to other alkali/alkaline earth/lanthanide and certain transition metal ions. A significant enhancement in fluorescence intensity was observed on binding to Ca2+ and Mg2+ ions; while a minor quenching was observed for weakly bound Hg2+, Ni2+, Fe3+, and Co2+ ions. PET process, coupled with the ICT process, is proposed to explain the observed spectral response.
2009-01-01
Microscopic model for the higher-order nonlinearity in optical filaments
Using an exactly soluble one-dimensional atomic model we explore the idea that the recently observed high-order nonlinearity in optical filaments is due to virtual transitions involving the continuum states. We show that the model's behavior is qualitatively comparable with the experimentally observed cross-over from self-focusing to de-focusing at high intensities, and only occurs at intensities which result in significant ionization. Based on these observations, we conjecture that this continuum electron nonlinear refraction exhibits strong memory effects, and most importantly, the change of its sign is effectively masked by the de-focusing due to free electrons.
2010-01-01
Ground level cosmic ray observations
Energy Technology Data Exchange (ETDEWEB)
Cosmic rays at ground level have been collected using the NMSU/Wizard - MASS2 instrument. The 17-hr observation run was made on September 9. 1991 in Fort Sumner, New Mexico, Usa. Fort Sumner is located at 1270 meters a.s.l., corresponding to an atmospheric depth of about 887 g/cm{sup 2}. The geomagnetic cutoff is 4.5 GV/c. The charge ratio of positive and negative muons and the proton to muon ratio have been determined. These observations will also be compared with data collected at a higher latitude using the same basic apparatus.
1995-09-01
Radon transport in an activated charcoal canister
Energy Technology Data Exchange (ETDEWEB)
The transport of Rn through activated charcoal was modelled for a charcoal canister used for surface emanation measurements. Derived Rn concentration distributions in full and half charcoal charges were compared with measured Rn profiles. The distributions were also compared with an empirical expression for the measured profiles. Close agreement was observed between the measured, empirically generated and derived profiles. The influence of temperature and humidity on Rn accumulation and transport is also discussed.
1989-02-01
Kinetics of lead retention and distribution in suckling and adult rats
International Nuclear Information System (INIS)
The kinetics of lead distribution was studied in suckling and adult rats 8 days after a single intraperitoneal injection of "2"0"3Pb. Marked differences were observed in the kinetics of lead retention and distribution in suckling as compared to adult rats. The rate of "2"0"3Pb disappearance was lower in the whole body, blood and kidneys, but higher in the liver, while the deposition processes predominated in the brain, femur and teeth of sucklings as compared to adult animals. (auth).
Cosmic time dilation: The clock paradox revisited
Energy Technology Data Exchange (ETDEWEB)
The relativistic time dilation is reviewed in a cosmological context. We show that a clock or twin paradox does not arise if cosmic time is properly taken into account. The receding galaxy background provides a unique frame of reference, and the proper times of geodesic as well as accelerated observers can be linked to the universal cosmic time parameter. This suggests to compare the proper time differentials of the respective observers by determining their state of motion in the galaxy grid. In this way, each observer can figure out whether his proper time is dilated or contracted relative to any other. In particular one can come to unambiguous conclusions on the aging of uniformly moving observers, without reference to asymmetries in measurement procedures or accelerations they may have undergone.
2004-05-01
British Library Electronic Table of Contents (United Kingdom)
A distributed watershed hydrologic model soil and water assessment tool (SWAT, 2000 Version) was applied to simulate stream flow and nutrient loadings (including total nitrogen (TN) and total phosphorus (TP)) in Gucheng Lake Basin, which is located in the lower reach of Yangtze River Basin. Model parameters related to stream flow and nutrient loadings were calibrated and validated by the observed value, and the simulation showed that the simulated values were reasonably comparable to the observed data, suggesting the validity of SWAT model. The simulated surface runoff and nutrient yield between two stages, viz. 1981-2000 and 1951-1960, were compared, basically considering land reclamation in the mid-1970s. The result indicated that, the average annual runoff and output of TN and TP in 198...
2009-01-01
POP bioaccumulation in macroinvertebrates of alpine freshwater systems
International Nuclear Information System (INIS)
This study serves to investigate the uptake of POPs in the different trophic levels (scrapers, collectors, predators, shredders) of macroinvertebrate communities sampled from a glacial and a non-glacial stream in the Italian Alps. The presented results show that the contaminant concentrations in glacial communities are generally higher compared to those from non-glacial catchments, highlighting the importance of glaciers as temporary sinks of atmospherically transported pollutants. Moreover, the data also suggests that in mountain systems snow plays an important role in influencing macroinvertebrate contamination. The main chemical uptake process to the macroinvertebrates is considered to be bioconcentration from water, as similar contaminant profiles were observed between the different trophic levels. The role of biomagnification/bioaccumulation is thought to be absent or negligible. The enrichment of chemicals observed in ...
2009-12-01
Indirect Dark Matter Signals from EGRET and PAMELA compared
Dark Matter annihilation (DMA) may yield an excess of gamma rays and antimatter particles, like antiprotons and positrons, above the background from cosmic ray interactions. The excess of diffuse Galactic Gamma Rays from EGRET shows all the features expected from DMA. The new precise measurements of the antiproton and positron fractions from PAMELA are compared with the EGRET excess. It is shown that the charged particles are strongly dependent on the propagation model used. The usual propagation models with isotropic propagation models are incompatible with the recently observed convection in our Galaxy. Convection leads to an order of magnitude uncertainty in the yield of charged particles from DMA, since even a rather small convection will let drift the charged particles in the halo to outer space. It is shown that such anisotropic propagation models including convection prefer a contribution from DMA for the antiprotons, but the rise in the ...
2009-01-01
Dialysis membrane for separation on microchips
Energy Technology Data Exchange (ETDEWEB)
Laser-induced phase-separation polymerization of a porous acrylate polymer is used for in-situ fabrication of dialysis membranes inside glass microchannels. A shaped 355 nm laser beam is used to produce a porous polymer membrane with a thickness of about 15 .mu.m, which bonds to the glass microchannel and forms a semi-permeable membrane. Differential permeation through a membrane formed with pentaerythritol triacrylate was observed and quantified by comparing the response of the membrane to fluorescein and fluorescently tagging 200 nm latex microspheres. Differential permeation was observed and quantified by comparing the response to rhodamine 560 and lactalbumin protein in a membrane formed with SPE-methylene bisacrylamide. The porous membranes illustrate the capability for the present technique to integrate sample cleanup into chip-based analysis systems.
2010-07-13
On the suitability of alternate fuels for dual fuel engine operation
Energy Technology Data Exchange (ETDEWEB)
A compression ignition engine was operated on dual fuel principle inducting two commercial fuels and four pure hydrocarbon fuels in turn through intake manifold along with air and injecting diesel fuel to initiate the combustion in the conventional manner. The engine was operated at different loads and at each load the quantity of inducted fuel was increased gradually till knocking set in. The engine performance and exhaust pollutant emissions were recorded at different operating conditions. It was observed that the extent of induction and the effect on the performance depend on the properties of the inducted fuel such as volatility, self ignition temperature and oxidation characteristics. The energy release during the cycle was also observed to shift depending on the properties of inducted fuel. With the dual fuel operation, the thermal efficiency at part loads was observed to be less compared to neat ...
1980-12-01
Luminescence properties of Ca- and Yb-codoped SiAlON phosphors
International Nuclear Information System (INIS)
Luminescence properties of SiAlON phosphors codoped with Ca and Yb were investigated by changing the host lattice composition. These modifications of the host lattice were obtained by replacing Si-N bonds by Al-N and Al-O bonds. Their photoluminescence (PL) and cathodoluminescence (CL) properties were measured and compared with each other. PL allows observing the influence of the host lattice modifications by measuring wider areas. CL can excite all luminescent centers, in particular the UV luminescence centers, even if their amount is small. Thus, two additional peaks in the ultraviolet and infrared regions were observed in CL, which is not observed by PL. This work suggests that the combination of PL and CL gives more understanding about the luminescence of SiAlON phosphors, in particular the role of the secondary phases on their properties.
2008-01-15
Dynamic Model Updating Using Particle Swarm Optimization Method
This paper proposes the use of particle swarm optimization method (PSO) for finite element (FE) model updating. The PSO method is compared to the existing methods that use simulated annealing (SA) or genetic algorithms (GA) for FE model for model updating. The proposed method is tested on an unsymmetrical H-shaped structure. It is observed that the proposed method gives updated natural frequencies the most accurate and followed by those given by an updated model that was obtained using the GA and a full FE model. It is also observed that the proposed method gives updated mode shapes that are best correlated to the measured ones, followed by those given by an updated model that was obtained using the SA and a full FE model. Furthermore, it is observed that the PSO achieves this accuracy at a computational speed that is faster than that by the GA and a full FE model which is faster than the SA and a full ...
2007-01-01
Cyclic Spectral Analysis of Radio Pulsars
Cyclic spectral analysis is a signal processing technique designed to deal with stochastic signals whose statistics vary periodically with time. Pulsar radio emission is a textbook example of this signal class, known as cyclostationary signals. In this paper, we discuss the application of cyclic spectral analysis methods to pulsar data, and compare the results with the traditional filterbank approaches used for almost all pulsar observations to date. In contrast to standard methods, the cyclic spectrum preserves phase information of the radio signal. This feature allows us to determine the impulse response of the interstellar medium and the intrinsic, unscattered pulse profile directly from a single observation. We illustrate these new analysis techniques using real data from an observation of the millisecond pulsar B1937+21.
2011-01-01
We present high-precision time-series photometry of the classical delta Scuti star HD 144277 obtained with the MOST (Microvariability and Oscillations of STars) satellite in two consecutive years. The observed regular frequency patterns are investigated asteroseismologically. HD 144277 is a hot A-type star that is located on the blue border of the classical instability strip. While we mostly observe low radial order modes in classical delta Scuti stars, HD 144277 presents a different case. Its high observed frequencies, i.e., between 59.9c/d (693.9 microHz) and 71.1c/d (822.8microHz), suggest higher radial orders. We examine the progression of the regular frequency spacings from the low radial order to the asymptotic frequency region. Frequency analysis was performed using Period04 and SigSpec. The results from the MOST observing runs in 2009 and 2010 were compared to each other. ...
2011-01-01
Exploring the patterns and causes of land use changes in south-west Sweden
British Library Electronic Table of Contents (United Kingdom)
To study the causes of agricultural declines in south-west Sweden, a multi-proxy study including pollen analysis, bog surface wetness indicators and aeolian sediment influx reconstructions was carried out on the Store Mosse Bog, situated on the coastal plain of Halland. Patterns of agricultural changes during the past 6,000?years from this study were compared to one additional site on the coastal plain (Undarsmosse Bog) and to four sites in the forested upland region. First, we compared land use activity on the coastal plain and in upland regions of south-west Sweden. Three periods with reduced agricultural activities were observed, primarily in records from the coastal plain. Next, the causes for these declines were studied by comparing land use indicators in the pollen records from the S...
2011-01-01
Comparing dose calculation algorithms for an orthovoltage beam in a bone phantom
International Nuclear Information System (INIS)
The aim of this work was to compare dose calculation algorithm results at orthovoltage energies for a phantom composed of a bone slab in water. The calculation methods investigated were: no correction, ETAR, Batho, convolution/superposition and Monte Carlo. All algorithms calculated depth dose curves in a water phantom within 4% of experiment. However in the bone phantom, differences of over 40% between the No Correction / ETAR / Batho / Convolution and Monte Carlo results in the 1 cm thick bone slab were observed. These differences are predominantly because the algorithms do not account for the differing atomic number of the bone compared to water The increased dose to bone and the tissue adjacent to the bone interface should be considered when treating with orthovoltage photons. Copyright (1998) Australasian Physical and Engineering Sciences in Medicine
1998-09-01
Technetium transfer from soil to plants
International Nuclear Information System (INIS)
Technetium transfer from soil to edible parts of various agricultural plants is studied with application of the "9"5"mTc radioactive tracer. The samples of agricultural plants were grown on andesol typical for Japan soil. The technetium transfer factor to edible parts of cultivated lettuce was higher as compared to non foliate cultures. Relative low transfer factor were observed for fruit and pod like plants. the transfer factors for root crops were of intermediate value
Mobilization of plutonium burdens during pregnancy
International Nuclear Information System (INIS)
The mobilization and distribution of previously deposited "2"3"9Pu was compared in pregnant rats (15 and 20 days of gestation) and nonpregnant controls. Pregnancy had little effect on "2"3"9Pu tissue burdens and only minimal activity appeared in the fetoplacental unit. Marked differences were observed in tracer "4"5Ca deposition patterns between the experimental groups.
1977-05-01
Marsden-Ratiu reduction and W_3"2 algebra
International Nuclear Information System (INIS)
The W_3"2 algebra is deduced by the Marsden-Ratiu reduction in the bi-Hamiltonian framework proposed by Magri et al and compared with the usual derivations via the Drinfeld-Sokolov formalism. It is observed that the choice of A in the first Poisson tensor must be different for W_3"2 algebra. (orig.).
1997-01-01
Infrared stimulated luminescence-decay shape from NaCl as a function of radiation doses
Energy Technology Data Exchange (ETDEWEB)
Dose-dependent behavior of the infrared stimulated luminescence (IRSL) decay from NaCl has been studied experimentally using only one aliquot irradiated with a range of 2-200 Gy {beta}-radiation doses. It was observed that the maximum IRSL intensity has not changed by an increase in dose though the total intensity increased as expected. Considering the possible implications of our findings for dosimeter, the results were compared with the other studies and discussed.
2007-11-15
Energy Technology Data Exchange (ETDEWEB)
Experimental investigation was carried out for friction factor and heat transfer coefficient in the case of a rotating tube with a twisted-tape insert for heat transfer augmentation. The data obtained were compared with existing data for a stationary tube with a twisted-tape insert. It has been observed that the enhancement in heat transfer offsets the rise in friction factor due to rotation, with respect to a plain tube under stationary conditions. A correlation has been proposed for the data obtained.
1995-04-01
Evolution of a horizontal branch Population II star with total mass 0.63 Msub solar
The theoretical evolution of a horizontal branch star of Population II is followed through the helium burning in the core phase and is compared with the results given by other investigators. The m- fluence of different physics and interpolation schemes in the opacity tables is discussed. Some thoughts are given on the explanation of the erratic period variations observed in some of the RR Lyrae variables in the globular clusters. (auth)
1973-01-01
Electron scattering in molecular aggregates
International Nuclear Information System (INIS)
In this contribution we compare the electron scattering processes observed in pure O_2 clusters and mixed clusters like O_2/Ne, O_2/Ar and O_2/N_2. The overlap and positions of the potential curves of O_2 states show the different possible electron attachment processes and also explain the formation of O_2 in clusters. (author).
1994-03-20
International Nuclear Information System (INIS)
Isotopically selective IR multiphoton dissociation of molecules (SF_6, CF_3I) in a pulsed gas-dynamic flow interacting with a solid surface was studied for the first time. A noticeable (severalfold) increase in the yield of products (compared to excitation of molecules in an unperturbed flow) without a substantial decrease in the selectivity of the process was observed. Possible reasons for the effect are discussed. (laser applications and other topics in quantum electronics)
2000-08-31
Delta Scuti stars and stellar evolution
International Nuclear Information System (INIS)
Recent developments in the knowledge of Delta Scuti stars in relation to stellar evolution are reviewed. The stability of periods and amplitudes is examined, and a working hypothesis suggested. Furthermore, the systematics of the observed long-term period changes are compared with the computed evolutionary tracks, suggesting a severe disagreement for the evolved stars if the period changes are caused by radius changes resulting from stellar evolution. 30 refs.
1990-05-28
Coir fibre toxicity: in vivo and in vitro studies.
The biological activity of coir fibre, coir ash and their components were investigated in vitro by measuring the haemolytic activity and macrophage cytotoxicity. In vivo studies carried out by injecting guinea pigs intratracheally with coir fibres resulted in resolving granulomas. The observed haemolytic activity and macrophage cytotoxicity was more marked with coir ash compared with coir fibres. Chemical analysis of coir ash revealed the presence of toxic chemical constituents in appreciable amounts. PMID:6283694
1982-03-01
An idealized numerical simulation of mammatus-like clouds
British Library Electronic Table of Contents (United Kingdom)
A three-dimensional numerical simulation of mammatus-like clouds is presented. A portion of a cirrus outflow anvil cloud is simulated including cloud ice and snow microphysical representations. The simulated mammatus clouds appear in a cellular pattern and are compared with the few available previously published physical observations of mammatus. Copyright Copyright 2006 Royal Meteorological Society
2006-01-01
5f-electron localization in uranium compounds
International Nuclear Information System (INIS)
Observed 7-eV satellites in the XPS spectra of UGa_2 and other B-group compounds are shown to be due to two-hole final states as confirmed by existing Auger data. The presence of these satellites is an indication for a weak fd hybridization and, when compared to uranium--transition-metal compounds, increased 5f localization.
The clinical significance of Fuji computed radiography on lateral chest radiogram
Energy Technology Data Exchange (ETDEWEB)
The purpose of this study was to clarify the benefits of digital lateral chest radiogram. In the basic study, the modulation transfer factor (MTF) and the wiener spectra (WS) of conventional screen film (CSF) and Fuji computed radiography (FCR) were measured. The visibility of the simulated nodules on FCR using 3 human bodies was subjectively compared with that on CSF by 13 observers. In the clinical study, the visibility of the normal structures on FCR was subjectively compared with that on CSF using 50 lateral chest radiograms by 10 observers. The diagnostic performance to detect pulmonary nodules on FCR was also compared with that on CSF using each 30 positive and negative cases by 8 observers. In the basic study, the MTF of FCR was superior to that of CSF, and the WS of FCR displayed in half size was superior to that of CSF. In all exposure conditions, the ...
1995-02-01
The clinical significance of Fuji computed radiography on lateral chest radiogram
International Nuclear Information System (INIS)
The purpose of this study was to clarify the benefits of digital lateral chest radiogram. In the basic study, the modulation transfer factor (MTF) and the wiener spectra (WS) of conventional screen film (CSF) and Fuji computed radiography (FCR) were measured. The visibility of the simulated nodules on FCR using 3 human bodies was subjectively compared with that on CSF by 13 observers. In the clinical study, the visibility of the normal structures on FCR was subjectively compared with that on CSF using 50 lateral chest radiograms by 10 observers. The diagnostic performance to detect pulmonary nodules on FCR was also compared with that on CSF using each 30 positive and negative cases by 8 observers. In the basic study, the MTF of FCR was superior to that of CSF, and the WS of FCR displayed in half size was superior to that of CSF. In all exposure conditions, the ...
1995-01-01
International Nuclear Information System (INIS)
This paper presents a new methodology to create realistic 3D microstructures of polycrystals. The virtual microstructures are based on statistical data describing the morphological and crystallographic textures of a sample, obtained from an EBSD analysis. In addition, the methodology can reproduce the observed surface on top of the simulated microstructure. This feature allows finite element calculations on these virtual aggregates to be compared to experimental results of mechanical tests. Such a comparison leads to the identification of the mechanical parameters of constitutive laws, such as critical resolved shear stress and strain hardening, using an optimization algorithm. Two materials were simulated in this study: TiAl and grade 702 zirconium. The first one presents twins inside the microstructure and the second one has an anisotropic texture. Based on 2D simulations, the important parameters necessary to describe a microstructure were ...
Energy Technology Data Exchange (ETDEWEB)
The extent measurement error on CT colonography influences polyp categorisation according to established management guidelines is studied using twenty-eight observers of varying experience to classify polyps seen at CT colonography as either 'medium' (maximal diameter 6-9 mm) or 'large' (maximal diameter 10 mm or larger). Comparison was then made with the reference diameter obtained in each patient via colonoscopy. The Bland-Altman method was used to assess agreement between observer measurements and colonoscopy, and differences in measurement and categorisation was assessed using Kruskal-Wallis and Chi-squared test statistics respectively. Observer measurements on average underestimated the diameter of polyps when compared to the reference value, by approximately 2-3 mm, irrespective of observer experience. Ninety-five percent limits of agreement ...
2006-08-15
Stable p-channel polysilicon thin film transistors fabricated by laser doping technique
Energy Technology Data Exchange (ETDEWEB)
In this work we present the electrical characterization of non self-aligned p-channel thin film transistors fabricated by using laser doping technique for source/drain contact formation and gate oxide deposited at room temperature by Electron Cyclotron Resonance Plasma Enhanced Chemical Vapour Deposition. These techniques are suitable for a very low temperature process for TFT fabrication. The output characteristics show a current increase at high drain voltage ('kink' effect) rather moderate, if compared to self aligned polysilicon TFTs, probably due to the gradual doping profile induced by laser doping process. After bias stress at low gate voltage and high drain voltage condition a strong reduction of kink current has been observed in the output characteristics at high drain voltage, whereas minor changes has been observed in the transfer characteristics. This behaviour is similar to what ...
2005-09-01
Stable p-channel polysilicon thin film transistors fabricated by laser doping technique
International Nuclear Information System (INIS)
In this work we present the electrical characterization of non self-aligned p-channel thin film transistors fabricated by using laser doping technique for source/drain contact formation and gate oxide deposited at room temperature by Electron Cyclotron Resonance Plasma Enhanced Chemical Vapour Deposition. These techniques are suitable for a very low temperature process for TFT fabrication. The output characteristics show a current increase at high drain voltage ('kink' effect) rather moderate, if compared to self aligned polysilicon TFTs, probably due to the gradual doping profile induced by laser doping process. After bias stress at low gate voltage and high drain voltage condition a strong reduction of kink current has been observed in the output characteristics at high drain voltage, whereas minor changes has been observed in the transfer characteristics. This behaviour is similar to what observed in ...
2005-09-01
Observing Evolution in the Supergranular Length Scale During Periods of Low Solar Activity
We present the initial results of an observational study into the variation of the dominant length-scale of quiet solar emission: supergranulation. This length-scale reflects the radiative energy in the plasma of the upper solar chromosphere and transition region at the magnetic network boundaries forming as a result of the relentless interaction of magnetic fields and convective motions of the Sun's interior. We demonstrate that a net difference of ~0.5Mm in the supergranular emission length-scale occurs when comparing observations cycle 22/23 and cycle 23/24 minima. This variation in scale is reproduced in the datasets of multiple space- and ground-based instruments and using different diagnostic measures. By means of extension, we consider the variation of the supergranular length-scale over multiple solar minima by analyzing a subset of the Mt Wilson Solar Observatory (MWO) Ca II K image record. The ...
2011-01-01
Hard X-ray identification of Eta Carinae and steadiness close to periastron
Context: The colliding-wind binary Eta Car exhibits soft X-ray thermal emission that varies strongly around periastron, and non-thermal emission seen in hard X-rays and gamma-rays. Aims: To definitively identify Eta Car as the source of the hard X-ray emission, to examine how changes in the 2-10 keV band influence changes in the hard X-ray band, and to understand more clearly the mechanisms producing the non-thermal emission using new INTEGRAL observations obtained close to periastron. Methods: A Chandra observation encompassing the ISGRI error circle was analysed, and all other soft X-ray sources (including the outer shell of Eta Car itself) were discarded as likely counter-parts. New hard X-ray images of Eta Car were studied close to periastron, and compared to previous observations far from periastron. Results: The INTEGRAL component, when represented by a power law (with a photon index of 1.8), ...
2010-01-01
Cavitation during hot-torsion testing of Ti-6Al-4V
Hot-torsion testing was used to establish the cavitation behavior of a typical alpha/beta titanium alloy, Ti-6Al-4V, with a colony microstructure, during simple-shear deformation. For this purpose, sections of deformed specimens were examined by optical metallography, and by scanning and orientation-imaging microscopy (OIM). It was found that cavity nucleation occurred along prior beta boundaries as well as at triple points; in particular, most cavities nucleated along boundaries perpendicular to the axial direction of the specimen. Extensive growth was observed for cavities surrounded by both hard and soft orientations, with the soft colonies accommodating more of the imposed strain. At high degrees of deformation, dynamic globularization of the colony microstructure adjacent to the cavities was also observed. In addition, the metallographic observations revealed that the cavities did not grow in an equiaxed mode, but in ...
2005-12-01
Accretion onto Supermassive Black Holes in Quasars: Learning from Optical/UV Observations
Accretion processes in quasars and active galactic nuclei are still poorly understood, especially as far as the connection between observed spectral properties and physical parameters is concerned. Quasars show an additional degree of complexity compared to stars that is related to anisotropic emission/obscuration influencing the observed properties in most spectral ranges. This complicating factor has hampered efforts to define the equivalent of an Hertzsprung-Russel diagram for quasars. Even if it has recently become possible to estimate black hole mass and Eddington ratio for sources using optical and UV broad emission lines, the results are still plagued by large uncertainties. Nevertheless, robust trends are emerging from multivariate analysis of large spectral datasets of quasars. A firm observational basis is being laid out by accurate measurements of broad emission line properties especially ...
2006-01-01
International Nuclear Information System (INIS)
The Phebus FP project in an international reactor safety project. Its main objective is to study the release, transport and retention of fission products in a severe accident of a Light Water Reactor (LWR). The FPT4 test was performed with a fuel debris bed geometry, to look at late phase core degradation and the releases of low volatile fission products and actinides. Post Test Analyses results indicate that releases of noble gases (Xe, Kr) and high-volatile fission products (Cs, I) were nearly complete and comparable to those obtained during Phebus tests performed with a fuel bundle geometry (FPT1, FPT2). Volatile fission products such as Mo, Te, Rb, Sb were released significantly as in previous tests. Ba integral release was greater than that observed during FPT1. Release of Ru was comparable to that observed during FPT1 and FPT2. As in other Phebus tests, the Ru distribution suggests Ru ...
2006-03-01
Transmission nuclear resonance fluorescence measurements of "2"3"8U in thick targets
International Nuclear Information System (INIS)
Transmission nuclear resonance fluorescence measurements were made on targets consisting of Pb and depleted U with total areal densities near 86g/cm"2. The "2"3"8U content in the targets varied from 0% to 8.5% (atom fraction). The experiment demonstrates the capability of using transmission measurements as a non-destructive technique to identify and quantify the presence of an isotope in samples with thicknesses comparable to the average thickness of a nuclear fuel assembly. The experimental data also appear to demonstrate the process of notch refilling with a predictable intensity. Comparison of measured spectra to previous backscatter "2"3"8U measurements indicates general agreement in observed excited states. Evidence of two new "2"3"8U excited states and possibly a third state have also been observed.
2011-05-15
The evolution of the Cepheid stars
International Nuclear Information System (INIS)
The evolution of intermediate and high mass stars is reviewed focusing on the interpretation of Pop I Cepheids. First, a summary is given of the classical results of stellar evolution theory for the main evolutionary phases (main sequence and core He-burning) all over the HR diagram, putting into evidence the various points of disagreement with current observational data. Second, models incorporating the effect of convective overshoot, are reviewed, and studies are presented on the rich, young clusters in the Large Magellanic Cloud, in which the models are compared with the observational data. Arguments are given to favor the adoption of models with convective overshoot instead of the classical ones. Third, new results are presented for pulsational models of the Cepheid stars, and the shape of the instability strip in the HR diagram, the number frequency-period distribution, and the mass discrepancy are discussed. 81 refs.
1990-05-28
British Library Electronic Table of Contents (United Kingdom)
This study presents monthly estimates of groundwater anomalies in a large river basin dominated by extensive floodplains, the Negro River Basin, based on the synergistic analysis using multisatellite observations and hydrological models. For the period 2003-2004, changes in water stored in the aquifer is isolated from the total water storage measured by GRACE by removing contributions of both the surface reservoir, derived from satellite imagery and radar altimetry, and the root zone reservoir simulated by WGHM and LaD hydrological models. The groundwater anomalies show a realistic spatial pattern compared with the hydrogeological map of the basin, and similar temporal variations to local in situ groundwater observations and altimetry-derived level height measurements. Results highlight th...
2011-01-01
Properties of low residual stress silicon oxynitrides used as a sacrificial layer
Energy Technology Data Exchange (ETDEWEB)
Low residual stress silicon oxynitride thin films are investigated for use as a replacement for silicon dioxide (SiO{sub 2}) as sacrificial layer in surface micromachined microelectrical-mechanical systems (MEMS). It is observed that the level of residual stress in oxynitrides is a function of the nitrogen content in the film. MEMS film stacks are prepared using both SiO{sub 2} and oxynitride sacrificial layers. Wafer bow measurements indicate that wafers processed with oxynitride release layers are significantly flatter. Polycrystalline Si (poly-Si) cantilevers fabricated under the same conditions are observed to be flatter when processed with oxynitride rather than SiO{sub 2} sacrificial layers. These results are attributed to the lower post-processing residual stress of oxynitride compared to SiO{sub 2} and reduced thermal mismatch to poly-Si.
2000-01-04
Energy Technology Data Exchange (ETDEWEB)
The biological effects of ionizing radiation exposure are the result of a complex sequence of physical, chemical, biochemical, and physiological interactions. One way to begin a search for an understanding of health effects of radiation is through the development of phenomenological models of the response. Many models have been presented and tested in the slowly evolving process of characterizing cellular response. A range of models covering different endpoints and phenomena has developed in parallel. Many of these models employ similar assumptions about some underlying processes while differing about the nature of others. An attempt is made to organize many of the models into groups with similar features and to compare the consequences of those features with the actual experimental observations. It is assumed that by showing that some assumptions are inconsistent with experimental observations, the job of devising and ...
1990-09-01
British Library Electronic Table of Contents (United Kingdom)
To evaluate soil erodibility under different land uses and to study the applicability of nomograph for estimation of soil erodibility a field experiment was conducted under both natural and simulated rainfall conditions under four land uses viz. barren, cultivated, grassland, and forest in the sub-mountainous tract of Punjab (India). Measured soil erodibility (K) values varied from 033 to 067 under natural rainfall conditions and from 023 to 040 under simulated rainfall conditions. Among different land uses, measured K was in the order of barren > cultivated > grassland > forest soils. The values of the K estimated by nomograph were very low as compared to the observed values. The trends were also in contrast to these observed values of K under simulated and natural rainfall conditions. To...
2009-01-01
Metal Foam Heat Exchangers for Heat Transfer Augmentation from a Cylinder in Cross-Flow
British Library Electronic Table of Contents (United Kingdom)
A numerical study has been conducted to examine the heat transfer from a metal foam-wrapped solid cylinder in cross-flow. Effects of the key parameters including the free stream velocity and characteristics of metal foam such as porosity, permeability, and form drag coefficient on heat and fluid flow are examined. Being a determining factor in pressure drop and heat transfer increment, the porous layer thickness is changed systematically to observe that there is an optimum layer thickness beyond which the heat transfer does not improve while the pressure drop continues to increase. This has been verified by the application of Bejan?s Intersection of Asymptotes method. Results have been compared to those of a finned-tube heat exchanger to observe much higher heat transfer rate with reasonab...
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
Our understanding of prenatal behavior has been significantly advanced by techniques for direct observation and manipulation of unanesthetized, behaving rodent fetuses with intact umbilical connections to the mother. These techniques involve brief administration of an inhalant anesthesic, enabling spinal transection of the rat or mouse dam, after which procedures can continue with unanesthetized dams and fetuses. Because anesthetics administered to the mother can cross the placental barrier, it is possible that fetuses are anesthetized to varying degrees. We compared in perinatal rats the effects of prenatal maternal exposure to two inhalant anesthetics: ether and isoflurane. Fewer spontaneous fetal movements and first postpartum nipple attachments were observed following maternal exposure...
2007-01-01
Imaging subsurface using cross-correlation
Energy Technology Data Exchange (ETDEWEB)
This paper presents two imaging methods by using cross correlation. The one method images the subsurface by cross-correlation of the observed data and partial derivative seismograms calculated for a guessed model. The other method images the interface by use of cross-correlation of the virtual sources and the back propagated wave fields calculated from the observed data. Experimental tests show that both methods image subsurface interfaces well even if the guessed model is different from the true one. These imaging methods are reverse time migration that we perform cross-correlation as an imaging condition and have an advantage, as compared to conventional waveform inversion method, that images subsurface structure without iterative perturbation of the assumed model. (author). 18 refs., 15 figs.
1997-12-31
Gamma-rays and neutrinos from the pulsar wind nebulae
Energy Technology Data Exchange (ETDEWEB)
We construct the time-dependent radiation model for the pulsar wind nebulae (PWNe), assuming that leptons are accelerated in resonant scattering with heavy nuclei, which are injected into the nebula by the pulsar. The equilibrium spectra of these particles inside the nebula are calculated taking into account their radiation and adiabatic energy losses. The spectra of {gamma}-rays produced by these particles are compared with the observations of the PWNe emitting TeV {gamma}-rays and predictions are made for the expected {gamma}-ray fluxes from other PWNe. Expected neutrino fluxes and neutrino event rates in a 1 km{sup 2} neutrino detector from these nebulae are also calculated. It is concluded that only the Crab Nebula can produce a detectable neutrino event rate in the 1 km{sup 2} neutrino detector. Other PWNe can emit TeV {gamma}-rays on the level of a few percent of that observed from the Crab Nebula.
2005-08-01
First observation of psi(2S)-->K_S K_L
The decay psi(2S)-->K_S K_L is observed for the first time using psi(2S) data collected with the Beijing Spectrometer (BESII) at the Beijing Electron Positron Collider (BEPC); the branching ratio is determined to be B(psi(2S)-->K_S K_L) = (5.24\\pm 0.47 \\pm 0.48)\\times 10^{-5}. Compared with J/psi-->K_S K_L, the psi(2S) branching ratio is enhanced relative to the prediction of the perturbative QCD ``12%'' rule. The result, together with the branching ratios of psi(2S) decays to other pseudoscalar meson pairs (\\pi^+\\pi^- and K^+K^-), is used to investigate the relative phase between the three-gluon and the one-photon annihilation amplitudes of psi(2S) decays.
2003-01-01
Exploring the Physics of Type Ia Supernovae Through the X-ray Spectra of their Remnants
We present the results of an ongoing project to use the X-ray observations of Type Ia Supernova Remnants to constrain the physical processes involved in Type Ia Supernova explosions. We use the Tycho Supernova Remnant (SN 1572) as a benchmark case, comparing its observed spectrum with models for the X-ray emission from the shocked ejecta generated from different kinds of Type Ia explosions. Both the integrated spectrum of Tycho and the spatial distribution of the Fe and Si emission in the remnant are well reproduced by delayed detonation models with stratified ejecta. All the other Type Ia explosion models fail, including well-mixed deflagrations calculated in three dimensions.
2005-01-01
Enhanced coherent undulator radiation from bunched electron beams
International Nuclear Information System (INIS)
When energetic bunches of electrons traverse an undulator field, they can spontaneously emit radiation both coherently and incoherently. Although it has generally been assumed that undulator radiation is incoherent at wavelengths short compared to the longitudinal size of the electron bunch, several recent observations have proved this assumption false. Furthermore, the appearance of coherent radiation is often accompanied by a significant increase in radiated power. Here we report observations of strongly enhanced coherent spontaneous radiation together with direct measurements, using transition radiation techniques, of the electron distributions responsible for the coherent emission. We also report demonstrated enhancements in the predicted spontaneous radiated power by as much as 6x10"4 using electron bunch compression. copyright 1996 American Institute of Physics.
1995-09-28
Caburization kinetics of alloy-800 in liquid sodium at 550_0C
International Nuclear Information System (INIS)
Preliminary observations on the isothermal carbon transfer in low-carbon Alloy-800 exposed in sodium with AISI-304 type of steel at 550_0 are reported. The alloy was found to undergo a carburization comparable or slightly lower than that observed for the AISI-304 stainless steel for carbon activities above 6 x 10 /sup -3/ at 550_0C, but was not found to decarburize below such a carbon activity value. In the examined range the chemical composition of the alloys does not affect the process out of the experimental uncertainty of measure. Conclusions concerning the effective diffusion for carbon in the alloy are formulated. Preliminary relationships were found for an empirical evaluation of the carburization of the Alloy-800 in sodium of known carbon activity.
International Nuclear Information System (INIS)
The Monte-Carlo method and experimental methods were used to determine the neutron fluxes in the irradiation channels of the Ghana Research Reactor -1. The MCNP5 code was used for this purpose to simulate the radial and axial distribution of the neutron fluxes within all the ten irradiation channels. The results obtained were compared with the experimental results. After the MCNP simulation and experimental procedure, it was observed that axially, the fluxes rise to a peak before falling and then finally leveling out. Axially and radially, it was also observed that the fluxes in the centre of the channels were lower than on the sides. Radially, the fluxes dip in the centre while it increases steadily towards the sides of the channels. The results have shown that there are flux variations within the irradiation channels both axially and radially. (au)
2009-01-01
Alpha decay of "2"1"6At and the level structure of "2"1"2Bi
International Nuclear Information System (INIS)
The level structure of "2"1"2Bi has been studied by observing the alpha decay of "2"1"6At which is in secular equilibrium with "2"2"0Fr and "2"2"4Ac. Eight states are observed and tentatively assigned to the configuration #pi#h_9_/_2#nu#(g_9_/_2)"3 and three to the configuration #pi#h_9_/_2#nu#(g_9_/_2)"2i_1_1_/_2. These two lowest configurations in "2"1"2Bi are compared with the corresponding configurations in "2"1"0Bi and the calculations of Warburton.
British Library Electronic Table of Contents (United Kingdom)
We compared an idealised mathematical model of the lower part of the pelagic food web to experimental data from a mesocosm experiment in which the supplies of mineral nutrients (nitrogen and phosphorous), bioavailable dissolved organic carbon (BDOC, as glucose), and silicate were manipulated. The central hypothesis of the experiment was that bacterial consumption of BDOC depends on whether the growth rate of heterotrophic bacteria is limited by organic-C or by mineral nutrients. In previous work, this hypothesis was examined qualitatively using a conceptual food web model. Here we explore the extent to which a ?simplest possible?? mathematical version of this conceptual model can reproduce the observed dynamics. The model combines algal?bacterial competition for mineral nutrients (phosphor...
2007-01-01
[High-dose thalamonal-rohypnol for premedication. A randomized double-blind study].
The combination of fentanyl and droperidol, Innovar, was compared to flunitrazepam (1-2 mg) in a higher dosage (2.5-5 ml) for i.m. premedication. We measured psychological (ESB) and physiological (blood pressure, heart rate, p.cortisol) stress parameters before and after premedication. Side effects were registered. The day after surgery the patients were asked about the quality of premedication. Flunitrazepam reduced anxiety; Innovar did not. After Innovar the feeling of weakness increased significantly compared to flunitrazepam. Two patients panicked and refused operation. Other severe side effects were not observed. There were slight advantages for flunitrazepam on physiological stress. Patients were more satisfied with flunitrazepam than with Innovar premedication. The results show that Innovar also in a higher dosage cannot be recommended for premedication. PMID:6391270
1984-10-01
Wood-plastic composites using woods native to Iran
International Nuclear Information System (INIS)
Radiation induced polymerization of methylmethacrylate and copolymerization of styrene-acrylonitrile mixture in mamrase Carpinus betulus was carried out by means of #gamma#-ray, under different moisture levels and additives. Under all conditions the degree of polymerization was as high as 60%. No pronounced differences were observed in the kinetics of the polymerization of MMA either with moisture content of wood nor with kind and amount of additives. At high moisture (80% RH) content the dimensional stability of wood-PMMA was increased four fold as compared with untreated wood. The hardness increased about 100% for a weight conversion of monomer of about 30 to 40%. Hardness of this wood-polymer composite is comparable to that of the best noble woods in the world. (author).
1978-10-26
Energy Technology Data Exchange (ETDEWEB)
This paper reports on a series of laboratory and controlled test site measurements of the thermal conductivity of polyisocyanurate foam laminated boardstock roof insulations produced with several different blowing agents; CFC-11, HCFC-123, HCFC-14lb, and two blends of the HCFCs. The behavior of the experimental foams with HCFCs is compared to that of conventional polyisocyanurate foam blown with CFC-11. Thermal drift observed from two years of field exposure is compared to laboratory accelerated aging tests and the laboratory and field measurement techniques are described. This work is part of a Joint Industry/Government Project established in the United States to evaluate the technical viability of HCFC alternative blowing agents for polyisocyanurate foam roof insulations.
1992-01-01
British Library Electronic Table of Contents (United Kingdom)
We revisit a recently proposed agent-based model of active biological motion and compare its predictions with own experimental findings for the speed distribution of bacterial cells, Salmonella typhimurium. Agents move according to a stochastic dynamics and use energy stored in an internal depot for metabolism and active motion. We discuss different assumptions of how the conversion from internal to kinetic energy d(v) may depend on the actual speed, to conclude that d 2 v ? with either ? = 2 or 1 ? < 2 are promising hypotheses. To test these, we compare the model?s prediction with the speed distribution of bacteria which were obtained in media of different nutrient concentration and at different times. We find that both hypotheses are in line with the experimental observations, with ? bet...
2011-01-01
Spectroscopic properties of the f-elements in compounds and solutions. [79 references
Energy Technology Data Exchange (ETDEWEB)
In this systematic examination of some of the spectroscopic properties of the f-elements we deal with both the trivalent lanthanides and actinides. We summarize the present status of our energy level calculations in single crystal matrices and in aqueous solution, and compare the predicted crystal-field structure in certain low-symmetry sites with that observed. Some interesting new structural insights are thereby gained. The state eigenvectors from these calculations are then used in part in reassessing and interpreting the intensities of transitions in aqueous solution via the Judd-Ofelt theory. The parameters of this theory derived from fitting experimental data are compared with those computed from model considerations. Finally, we discuss some recent contributions to the interpretation of excited state relaxation processes in aqueous solution. 79 references, 23 figures, 17 tables.
1982-01-01
Referential Failures and Affective Reactivity of Language in Schizophrenia and Unipolar Depression
British Library Electronic Table of Contents (United Kingdom)
Reference failures, and their increase in affectively negative conditions (known as affective reactivity of speech), are more frequently observed in schizophrenia patients than in normal controls, but no information is available comparing schizophrenia with depression, ie, a mental disorder closely linked to the concept of affective reactivity. To address this gap in the literature, the present study compared 24 schizophrenia inpatients, 21 unipolar depression inpatients and 21 normal controls. Two 10-minute conversational speech samples (1 on negative and 1 on positive memories) were collected from each patient. The transcripts of the audiotaped interviews were analyzed blindly for frequencies of 6 types of referential failures, employing the Communication Disturbances Index, adapted for ...
2011-01-01
Continuing the search for a fundamental law of mortality
Energy Technology Data Exchange (ETDEWEB)
For 170 years, scientists have attempted to explain why consistent temporal patterns of death are observed among individuals within populations. Historical efforts to identify a {open_quotes}law of mortality{close_quotes} from these patterns ended in 1935 when it was declared that such a law did not exist. These empirical tests for a law of mortality were constructed using mortality curves based on all causes of death. We predicted that patterns of mortality consistent with the historical concept of a law would be revealed if mortality curves for species were constructed using only senescent causes of death. Using data on senescent mortality for laboratory animals and humans, we demonstrate that patterns of mortality overlap when compared on a biologically comparable time scale. These results are consistent with the existence of a law of mortality following sexual maturity as asserted by Benjamin Gompertz and Raymond Pearl. ...
1997-08-01
Continuing the search for a fundamental law of mortality
Energy Technology Data Exchange (ETDEWEB)
for 170 years, scientists have attempted to explain why consistent temporal patterns of death are observed among individuals within populations. Historical efforts to identify a `law of mortality` from these patterns ended in 1935 when it was declared that such a law did not exist. These empirical tests for a law of mortality were constructed using mortality curves based on all causes of death. We predicted patterns of mortality consistent with the historical concept of a law would be revealed if mortality curves for species were constructed using only senescent causes of death. Using data on senescent mortality for laboratory animals and humans, we demonstrate patterns of mortality overlap when compared on a biologically comparable time scale. The results are consistent with the existence of a law of mortality following sexual maturity. The societal, medical, and research implications of such a law are discussed.
1996-03-01
British Library Electronic Table of Contents (United Kingdom)
This work reports a systematic comparative study of the technological properties of natural lattices and rubbers extracted from Hancornia speciosa Gomes and Hevea brasiliensis [(Willd. ex Adr. de Juss.) Muell.-Arg.] (clone RRIM 600) trees from 11 collections in Brazil throughout 2004. Natural rubber latex particle sizes and distributions were quite similar with an average diameter around 1 mm. Molecular weight, Wallace plasticity, and Mooney viscosity values were approximately the same for both rubbers. Fourier transform infrared spectroscopy peaks characteristic of natural rubber were observed for both Hancornia and Hevea. The measured differences in technological properties included lower values for Hancornia dry rubber content, % ash, % nitrogen, and plasticity retention index but highe...
2009-01-01
Apheresis affects bone and mineral metabolism
British Library Electronic Table of Contents (United Kingdom)
Background: Apheresis is a procedure to selectively obtain blood components. For the collection process citrate is routinely used. It inhibits coagulation by binding to ionized calcium and leads to metabolic alkalosis. Objective: Whether regular apheresis affects bone and mineral metabolism is unknown. The intention of this study was to investigate 1) the acute effects of apheresis on acid-base balance, bone and mineral metabolism and 2) to compare bone mineral density (BMD) at the lumbar spine and hip of donors to matched control subjects. Design: In this open, observational, single-center, cross-sectional study we enrolled 102 regular plasma and thrombocyte donors to pursue objective 1) and compared those to 102 matched controls (CTR) for objective 2). Results: Platelet donation led to s...
2010-01-01
British Library Electronic Table of Contents (United Kingdom)
An observational cohort study was conducted to compare the performance of the RIFLE (risk, injury, failure, loss and end-stage kidney disease), AKIN (acute kidney injury network) and conventional graded criteria to identify acute kidney injury (AKI) following SCT and to predict long-term mortality in 141 myeloablative allogeneic SCT (m-allo), 60 non-myeloablative allogeneic SCT (nm-allo) and 48 autologous SCT (auto) cases. The AKIN criteria had less ability to identify patients as having the lowest category, stage 1 (analogous to RIFLE risk): 33% (37%) in m-allo, 23% (32%) in nm-allo and 8.3% (16.7%) in auto. Cox regression showed that categories higher than the intermediate stage were independent predictors of mortality in all three definitions. The areas under receiver operating characte...
2010-01-01
British Library Electronic Table of Contents (United Kingdom)
Background There is some evidence that a patient?s pre-operative condition influences short-term and long-term post-operative outcomes. The aim of the present study is to compare the physiological and operative severity score for the enumeration of mortality and morbidity (POSSUM) and modified Glasgow prognostic score (mGPS) models in the prediction of post-operative outcome, both short term and long term, in patients undergoing resection of oesophago-gastric cancer. Patients and Methods Patients who underwent curative resection for oesophago-gastric cancer from January 2005 to May 2009 and who had data to score the POSSUM, P-POSSUM, O-POSSUM and mGPS models were included in the study. Observed morbidity and mortality rates were compared with predicted outcome in different risk groups. Bot...
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
A new microbial transglutaminase (MTGase or MTG, EC 2.3.2.13) from a Streptomyces sp. strain isolated from Brazilian soil samples was characterized in crude and purified forms. The aim of this work is to provide relevant information about a new transglutaminase and to compare its characteristics with the well-known commercial transglutaminase from Ajinomoto Co. Inc. (Activa? TG-BP). The enzyme from Streptomyces sp., in both crude and pure forms, exhibited optimal activity in the 6.0?6.5 pH range and at 35?40?C. The results for the commercial enzyme were the same. A second maximum of activity was observed at pH?10.0 with both the crude Streptomyces sp. enzyme and the commercial enzyme. This interesting fact has not been reported in the literature previously. The fact that this second maximu...
2010-01-01
Photochemical processes and ozone production in Finnish conditions
Energy Technology Data Exchange (ETDEWEB)
Photochemical ozone production is observed in March-September. Highest ozone concentrations and production efficiencies are observed in spring in the northern parts and in summer in the southern parts of the country. VOC concentrations are relatively low compared to continental areas in general. During the growing season a substantial part of the total reactive mass of VOCs is of biogenic origin. Large forest areas absorb ozone substantially, decreasing the ambient ozone concentrations in central and northern parts of Finland where long-range transport of ozone is relatively important compared to local production. The aim of the work conducted at Finnish Meteorological Institute has been to characterise concentrations of photochemically active species in the boundary layer and their photochemical formation and deposition including the effects on vegetation. Also interactions between the boundary layer ...
1996-12-31
Lubrication properties of molybdenum disulfide films deposited by RF sputtering method
Energy Technology Data Exchange (ETDEWEB)
A radio frequency sputtering apparatus with a pair of targets has been developed for depositing a film of uniform thickness onto a complex-geometric specimen such as the retainer of a ball bearing. The deposition characteristics of the apparatus were compared with those of the conventional sputtering apparatus. Lubrication properties of MoS/sub 2/ films made by these devices were also compared under a variety of conditions. Finally, friction and wear of MoS/sub 2/ films applied to angular-contact type ball bearings of 20 mm bore were studied in air, nitrogen and vacuo. The two-target sputtering has an advantage mentioned above. However, the films deposited by the method exhibited a rather short wear life because of the temperature rise of the substrate during ion bombardment and during the sputtering process. This temperature dependence was observed in films on those substrates that had been heated with a built-in heater ...
1986-01-01
Forecasting neutrino masses from combining KATRIN and the CMB: Frequentist and Bayesian analyses
We present a showcase for deriving bounds on the neutrino masses from laboratory experiments and cosmological observations. We compare the frequentist and Bayesian bounds on the effective electron neutrino mass m_beta which the KATRIN neutrino mass experiment is expected to obtain, using both an analytical likelihood function and Monte Carlo simulations of KATRIN. Assuming a uniform prior in m_beta, we find that a null result yields an upper bound of about 0.17 eV at 90% confidence in the Bayesian analysis, to be compared with the frequentist KATRIN reference value of 0.20 eV. This is a significant difference when judged relative to the systematic and statistical uncertainties of the experiment. On the other hand, an input m_beta=0.35 eV, which is the KATRIN 5sigma detection threshold, would be detected at virtually the same level. Finally, we combine the simulated KATRIN results with cosmological data in the form of ...
2007-01-01
Vibration experiment for a three-loop PWR reactor building
Energy Technology Data Exchange (ETDEWEB)
Forced vibration experiment has been conducted for the reactor building of Sendai Unit 1 nuclear power plant. The beam vibrational behaviors of the outer shielding building and the internal concrete structure have been observed by using a 50 tf vibration for low frequency region, and a 10 tf vibration for high frequency region, respectively. The outline of the experimental methods, the data handling system and the major results of experiment are described. The experimental results were simulated by an analytical model. The proper vibrational frequency and the vibration modes obtained by the analysis were compared with those obtained by the experiment. By these comparisons, the adequacy of the analytical method employed for the design was confirmed.
1983-12-01
The identical bands in [sup 177]Ta
Energy Technology Data Exchange (ETDEWEB)
The 4025/2 bands in [sup 177]Ta which are ''identical'' to the neighboring even-even [sup 176]Hf groundstate band have been extended to higher angular momentum. These bands in the two nuclei are seen to diverge from each other in the region of the first i[sub 13/2] neutron alignment. The lower observed crossing frequency for the 4025/2 bands indicates a lower deformation for these bands compared to [sup 176]Hf. Extensions to the h[sub 9/2] 5411/2 yrast band are also reported. (orig.)
1993-10-01
The identical bands in "1"7"7Ta
International Nuclear Information System (INIS)
The [402]5/2 bands in "1"7"7Ta which are ''identical'' to the neighboring even-even "1"7"6Hf groundstate band have been extended to higher angular momentum. These bands in the two nuclei are seen to diverge from each other in the region of the first i_1_3_/_2 neutron alignment. The lower observed crossing frequency for the [402]5/2 bands indicates a lower deformation for these bands compared to "1"7"6Hf. Extensions to the h_9_/_2 [541]1/2 yrast band are also reported. (orig.).
Tachyon cosmology, supernovae data, and the big brake singularity
International Nuclear Information System (INIS)
We compare the existing observational data on type Ia supernovae with the evolutions of the Universe predicted by a one-parameter family of tachyon models which we have introduced recently [Phys. Rev. D 69, 123512 (2004)]. Among the set of the trajectories of the model which are compatible with the data there is a consistent subset for which the Universe ends up in a new type of soft cosmological singularity dubbed big brake. This opens up yet another scenario for the future history of the Universe besides the one predicted by the standard #LAMBDA#CDM model.
2009-04-15
Sustaining integrated technology in undergraduate mathematics
British Library Electronic Table of Contents (United Kingdom)
The effective integration of technology into the teaching and learning of mathematics remains one of the critical challenges facing contemporary tertiary mathematics. This article reports on some significant findings of a wider study investigating the use of technology in undergraduate mathematics. It first discusses a taxonomy developed to describe and compare technology use within individual courses and departments that identifies a complex range of factors, summarized under six defining characteristics of an integrated technology mathematics curriculum (ITMC). An instrument for a simple comparison of technology use employing the elements of this taxonomy is provided. It then presents evidence gathered from an observational study of technology implementation at The University of Auckland...
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
The relaxation oscillation of the amplified spontaneous radiation pulses emitted from a single-mirror Cu/CuBr laser has been observed for the first time and the experimental characteristics of the relaxation oscillation were obtained. In addition, the spatial and temporal distributions of the light pulse intensity of the amplified spontaneous radiation were also measured and found to be comparatively and uniform. The spatial coherence of the amplified spontaneous radiation was found to be better than that of the laser with the same lasant.
1985-10-01
Reactive sticking coefficients for silane and disilane on polycrystalline silicon
Energy Technology Data Exchange (ETDEWEB)
Reactive sticking coefficients (RSCs) were measured for silane and disilane on polycrystalline silicon for a wide range of temperature and flux (pressure) conditions. The data were obtained from deposition-rate measurements using molecular beam scattering and a very low-pressure cold-wall reactor. The RSCs have nonlinear Arrhenius temperature dependencies and decrease with increasing flux at low (710 /sup 0/C) temperatures. Several simple models are proposed to explain these observations. The results are compared with previous studies of the SiH/sub 4//Si(s) reaction and low-pressure chemical vapor deposition-rate measurements.
1988-04-15
Propagation of jarrah (Eucalyptus marginata) by organ and tissue culture
Energy Technology Data Exchange (ETDEWEB)
Micropropagation methods are described for the production of clonal lines from Eucalyptus marginata (jarrah) seedlings. Nodal explants from mature trees can also yield shoot cultures, but a high frequency of contamination occurs among such explants. Uncontaminated callus cultures can be produced from mature trees by culturing stamen filaments and shoots can subsequently be regenerated from this callus. The rooting percentage of shoot cultures from either nodes or stamen callus of mature trees is low compared with that from seedling explants. Considerable variation was observed between trees in the ability of stamen callus to regenerate shoots and in the frequency of rooting. (Refs. 27)
1982-01-01
Propagation of jarrah (Eucalyptus marginata) by organ and tissue culture
Energy Technology Data Exchange (ETDEWEB)
Methods are described for the production of callus and subsequent shoot and root induction and multiplication using stamen filaments, nodes of young stems of mature trees or cotyledon petioles. A high frequency of contamination occurred using nodal sections from mature trees, whereas up to 100% sterility was obtained with cotyledons and stamens. The rooting % of shoot cultures from nodes or stamen callus was low compared with that of shoots from seedling callus. Considerable variation was observed between clones from different trees in their ability to produce shoots and roots. 27 references
1982-01-01
Energy Technology Data Exchange (ETDEWEB)
System-level-operational testing of the ETX-II test-bed electric vehicle is described and the results discussed. Because the traction battery is a major factor in the performance of an electric vehicle, previously reported work on the sodium-sulfur battery designed for use with the ETX-II is reviewed in detail. Chassis dynamometer performance of the test-bed vehicle met or exceeded design goals and compared reasonably well with SIMPLEV computer modeling results. Areas are identified wherein further work is needed to establish a firmer basis for comparison of the simulation and the observed results.
1993-06-01
Optimization of inspection and replacement period by using Bayesian statistics
International Nuclear Information System (INIS)
This study describes the formulations to optimize the time interval of inspections and/or replacements of equipment/parts taking into account the probability density functions (PDF) for failure rates and parameters of failure distribution functions (FDF) and evaluates the optimized results of these time intervals using our formulations by comparing with those using only representative values of failure rates and the parameters of FDF instead of using these PDFs. The PDFs are obtained with Bayesian method and the representative values are obtained with likelihood estimation method. However, any significant difference is not observed between both optimized results within our preliminary calculations. (author)
2006-07-01
Nuclear design analysis of wolsung-1 CANDU-PHW nuclear generating station
International Nuclear Information System (INIS)
A combination of computer codes such as LATREP, HWRAXAV and CITATION is utilized in an attempt to analyze the nuclear design characteristics of the CAXDU-PHWR of the Wolsung Unit 1. The major nuclear properties to be computed are the lattice properties of CANDU fuel channel and the core channel power distribution. The computed results are compared with the preliminary safety reports documentation for the Wolsung reactor. The observed discrepancies between our computations and the preliminary safety reports values are discussed in terms of incomplete information on the description of the core configuration in the preliminary safety reports and the different calculation methods. (author).
1978-01-01
Nuclear data sheets for A = 177
International Nuclear Information System (INIS)
Nuclear structure information for all nuclei with mass number A = 177 is summarized. Data from various decay and reaction experiments are compared. Evaluated data and the adopted spin, parity, and Nilsson--state assignments are given. Deviations from the regional trend of Nilsson ground-state assignments are noted for "1"7"7W and "1"7"7Re. Similar shifts have been observed in this region for nuclei 8 to 10 neutrons removed from the #beta#-stability line. In all cases, low-lying K/sup #pi#/ = 1/2/sup +-/ orbitals move to ground. Data received prior to February 1975 were included. (auth).
Multielement analysis of air samples
International Nuclear Information System (INIS)
Radionuclide X-ray fluorescence analysis for nondestructive determination of Fe, Zn, Pb, and Br in air samples collected on nitrocellulose membrane filter Synpor 4 is described. A "2"3"8Pu source for the excitation and a semiconductor Si/Li detector for the detection of characteristic and L-fluorescent radiation of the above elements were used. A correction method based upon the measurements of simple or multiple Compton scattering for compensation of varying mass per unit area values in sample deposits was theoretically proposed and experimentally tested. The results obtained both with and without the correction were compared and good agreement with those given by atomic absorption spectrometry was observed. (author).
1981-01-01
Magnetic response of ultrathin Fe on MgO: A polarized neutron reflectometry study
Energy Technology Data Exchange (ETDEWEB)
The magnetization of ultrathin bcc Fe films (two and three monolayers) on MgO was measured and compared with the behavior predicted for a two-dimensional ferromagnet. The experiment indicated that no hysteresis was present in the magnetization. Instead, the magnetization at low temperature was affected by a marked field cooling effect. These observations lead to the conclusion that films of Fe on MgO of such thickness exhibit superparamagnetic behavior as if they were not entirely continuous. In contrast, films thicker than five monolayers exhibit a magnetic response close to that of bulk iron.
1994-11-15
Knock limitations of methane-air mixtures in a turbocharged dual-fuel engine
Energy Technology Data Exchange (ETDEWEB)
Knock limitations are investigated using natural gas, with diesel pilot ignition, as a fuel for the 3406 DI-TA Caterpillar diesel engine. Thermodynamic properties at TDC are generated by computer and compared with experimental results. Exhaust emissions are analyzed. A comparison is made of dual-fuel operation relative to diesel. Observations are made to determine the onset of knock. The onset of knock is characterized as a function of engine speed, load, inlet manifold temperature, and air-fuel ratio (A/F). The conditions at the inset of knock are determined using cylinder pressure data. The most efficient operating range is determined with knock avoidance as a prime parameter.
1987-01-01
Evolution of binary stars in the LMC with helium enrichment
International Nuclear Information System (INIS)
Recent surveys of supergiants stars in the LMC indicate that the post-main-sequence region of the colour-magnitude diagram is well populated, although numerical evolution of massive stars with normal surface hydrogen indicates to the contrary. Supergiant stars having surface enrichment of helium acquired for example from a previous phase of accretion from a binary companion, however, evolve in a way so that the evolved models and observed data are consistent. We compare the available data with computed evolutionary tracks of massive stars of metallicity relevant to the LMC with and without helium-enriched envelopes and conclude that a large fraction of supergiant stars may occur in binaries. (author).
Engineering electromagnetic response of composite terahertz metamaterial with broken symmetry
We proposed and numerically investigated the influence of spatial symmetry on the terahertz frequency region response of composite planar metamaterials based on deformed split ring resonators. Compared with the original simple structures, the composite metamaterials with different spatial symmetries exhibited exotic electromagnetic properties. The electromagnetic response of a specific configuration with C4 symmetry was identical to the structure with simple lattice. Especially, for configurations with broken symmetry, very sharp Drude-like resonances with high quality factor were observed. The electric field and current distribution associated the resonances were analyzed for deep understanding of the underlying physical properties.
2011-09-01
Electrical properties of airborne nanoparticles produced by a commercial spark-discharge generator
International Nuclear Information System (INIS)
A nanoparticle generator based on the principle of electrical discharge (PALAS GFG-1000) was used to produce nanoparticles of different chemical natures. The fractions of electrically neutral particles were then measured by means of a Spectrometre de Mobilite Electrique Circulaire (SMEC, i.e. radial-flow mobility analyzer) for different operating conditions. The experimental results were compared with the theoretical values calculated from the Fuchs extended charge equilibrium model for spherical particles and agglomerates. For the smallest particles (below 20 nm), the deviations observed remain below 10%, and tend towards 20% for larger particles (over 35 nm).
2010-08-01
Effects of avalanche hole injection in fluorinated SiO[sub 2] MOS capacitors
Energy Technology Data Exchange (ETDEWEB)
Significantly improved immunity to hot-hole damage of the SiO[sub 2]/Si structure is achieved by a shallow fluorine implantation into the poly-Si gate of MOS capacitors followed by a drive-in process. Compared to the nonfluorinated control, the fluorinated samples exhibit a dramatic reduction of both hole trapping probability and interface-trap generation under avalanche hole injection conditions. The degree of such an improvement increases monotonically as a function of the F implantation dose (up to 10[sup 16]/cm[sup 2]). Significant decrease of the hole detrapping rate is also observed in fluorinated samples. Possible mechanisms are discussed.
1993-04-01
Damage mechanism in high temperature fatigue of alloy 800 H
Energy Technology Data Exchange (ETDEWEB)
In order to investigate the influence of grain boundary cavities on the life time of Alloy 800 H various fatigue tests have been performed at 800/sup 0/C. Cavity formation has been observed only in asymmetrical tests. Compared to the corresponding symmetrical tests, the cyclic life time is shorter. As the cavitation damage increases, the ratio of life times in vacuum and in air steadily decreases from an initial value of 5. In extreme cases it can reach a value close to 1. In this case, cavitation damage dominates over the usual damage mechanism, which is cracks from the surface.
1986-09-01
Continuous measurement of blast-furnace coke moisture
International Nuclear Information System (INIS)
After presenting the advantages of applying neutron moisture gages to the continuous measurement of blast-furnace coke moisture and explaining the factors influencing the measurement accuracy, the necessity of calibrating these devices under flow conditions and the encountered difficulties are discussed. Using statistical methods it has been observed that the main source of calibration errors is the sampling phase. Based on results of mathematical processing, a new calibration method with higher performance - compared with the earlier ones - is proposed. This method allows to achieve high accuracy in a relatively short time. (author).
This study compares the effectiveness of potassium chloride with guanidine chlorhydrate in the prevention of clay swelling. The results given on various swelling tests on calcic montmorillonite led to the conclusions that (1) guanidine chlorhydrate is more effective than potassium chloride, especially in low concentrations, and (2) water immersion of samples treated by both solutions shows the permanent feature of the inhibitive action of guanidine chlorhydrate in swelling on one hand and the important increase in swelling of immersed samples treated by potassium chloride on the other. The viscosity measure of montmorillonite suspensions, before and after solution ion elimination by dialysis, confirms these observations.
1982-08-01
Comparison of the green- and infrared-stimulated luminescence of feldspar
Energy Technology Data Exchange (ETDEWEB)
The differences are highlighted of various aspects of behaviour of the luminescence signal from feldspar when stimulated by green light and when stimulated by infrared radiation. In respect of bleaching, a comparison is made of the influence of white light (daylight) on the two stimulated luminescence signals, as well as a comparison of the influence of infrared exposure on the green-stimulated signal with the influence of green exposure on the infrared-stimulated signal. The influence of preheating on the two stimulated signals is also compared. Light-emitting diode systems were used for both green and infrared stimulation. The observations are considered in relation to the mechanism relevant to green- and infrared-stimulated luminescence from feldspar. (author).
1994-04-01
Comparison of the green- and infrared-stimulated luminescence of feldspar
International Nuclear Information System (INIS)
The differences are highlighted of various aspects of behaviour of the luminescence signal from feldspar when stimulated by green light and when stimulated by infrared radiation. In respect of bleaching, a comparison is made of the influence of white light (daylight) on the two stimulated luminescence signals, as well as a comparison of the influence of infrared exposure on the green-stimulated signal with the influence of green exposure on the infrared-stimulated signal. The influence of preheating on the two stimulated signals is also compared. Light-emitting diode systems were used for both green and infrared stimulation. The observations are considered in relation to the mechanism relevant to green- and infrared-stimulated luminescence from feldspar. (author).
1993-07-01
Autonomic Management of Maintenance Scheduling in Chord
This paper experimentally evaluates the effects of applying autonomic management to the scheduling of maintenance operations in a deployed Chord network, for various membership churn and workload patterns. Two versions of an autonomic management policy were compared with a static configuration. The autonomic policies varied with respect to the aggressiveness with which they responded to peer access error rates and to wasted maintenance operations. In most experiments, significant improvements due to autonomic management were observed in the performance of routing operations and the quantity of data transmitted between network members. Of the autonomic policies, the more aggressive version gave slightly better results.
2010-01-01
International Nuclear Information System (INIS)
The asymmetric fingered structure for polysilicon thin-film transistors (AF-TFTs) is analysed in detail by combining experimental characteristics and two-dimensional numerical simulations. This structure allows an effective reduction of the kink effect and off-current, without introducing any additional series resistance. In addition, a substantial improvement in the device stability is also observed when compared to conventional TFT. The AF-TFT characteristics have been explained by considering a two transistor model.
2006-01-01
A low temperature synthesized NbC grain growth inhibitor in WC-Co hardmetal alloy
Energy Technology Data Exchange (ETDEWEB)
The efficiency of NbC on WC grain coarsening in a WC-10wt.%Co hardmetal alloy was demonstrated by hardness measurement and WC granulation observation. The heterogeneous and overall grain growth were controlled. A low temperature experimentally produced NbC was used and compared to the inhibition potential of a commercial NbC powder. The results were the same in terms of structural fineness and hardness. The dispersion of the experimental NbC was not a problem, in spite of its size. The experimental NbC has very large particles, formed by agglomerates of small crystallites. During milling these agglomerates could be broken down. (orig.)
2001-07-01
International Nuclear Information System (INIS)
The A dependence of cumulative pion production yield cross sections on the basis of the comparison of the data on relative pion yields on Be,C,Al,Ti,Mo and W nuclei at the 159 deg angle laboratory system for the incident proton energy E_0 from 25 to 62 GeV is considered. The regular A dependence on cumulative variable X is noted. The results are compared with the data at E_0< 10 GeV. A possible interpretation of the observed behaviour on the basis of the hypothesis of the flucton mechanism of the pion production in the cumulative region is discussed. 15 refs.; 4 figs.
A critical study of poiseuille flow of couple stress fluid with applications to blood flow
It is shown that the method used for comparing theoretical and experimental results is erroneous and the values of the couple stress parameters obtained for blood flow are incorrect. A method for determining the couple stress parameters is presented. The computational work in the improved method is considerably less. It is observed that both the couple stress parameters are functions of concentration. An empirical relation between concentration and the stress parameters is obtained. The shear viscosity and non-dimensional axial velocity are functions of concentration. Some uses of determining the values of the couple stress parameters are suggested.
1981-01-01
Energy Technology Data Exchange (ETDEWEB)
Molar excess volumes, V{sup E}, molar excess enthalpies, H{sup E}, and speeds of sound, u, of o-toluidine (i) + cyclohexane or n-hexane or n-heptane (j) binary mixtures have been determined over entire range of composition at 308.15 K. Speeds of sound data have been utilized to predict isentropic compressibility changes of mixing, {kappa}{sub S}{sup E} of (i + j) mixtures. The observed V{sup E}, H{sup E} and {kappa}{sub S}{sup E} data have been analyzed in terms of Graph theory. The analysis of V{sup E} data by Graph theory reveals that o-toluidine exists as an associated molecular entity and (i + j) mixtures contain 1:1 molecular complex. It has been observed that V{sup E}, H{sup E} and {kappa}{sub S}{sup E} values calculated by Graph theory compare well with their corresponding experimental values. The observed data have also been analyzed in term of Flory theory.
2008-09-15
International Nuclear Information System (INIS)
Molar excess volumes, VE, molar excess enthalpies, HE, and speeds of sound, u, of o-toluidine (i) + cyclohexane or n-hexane or n-heptane (j) binary mixtures have been determined over entire range of composition at 308.15 K. Speeds of sound data have been utilized to predict isentropic compressibility changes of mixing, ?SE of (i + j) mixtures. The observed VE, HE and ?SE data have been analyzed in terms of Graph theory. The analysis of VE data by Graph theory reveals that o-toluidine exists as an associated molecular entity and (i + j) mixtures contain 1:1 molecular complex. It has been observed that VE, HE and ?SE values calculated by Graph theory compare well with their corresponding experimental values. The observed data have also been analyzed in term of Flory theory.
2008-09-15
Spectroscopy of "8"8Sr with the "8"7Sr(n,#gamma#) and "8"7Sr(d,p) reactions
International Nuclear Information System (INIS)
The #gamma#-ray spectrum emitted after thermal neutron capture in "8"7Sr was studied at the ILL high flux reactor with pair- and intrinsic Ge-spectrometers. 661 transitions were assigned to the reaction "8"7Sr(n,#gamma#)"8"8Sr and 205 of them were placed into a "8"8Sr level scheme of 47 levels. This represents 88% of the observed intensity. The level energies were determined with a precision of better than 22 ppm; the neutron binding energy was determined as 11 112.69 (22) keV. To aid the analysis high resolution particle spectra of the reaction "8"7Sr(d,p)"8"8Sr were measured at 20 MeV deuteron energy with the Munich Q3D spectrometer. 85 states were observed with this reaction. The data helped to establish newly found levels and to differentiate between primary and secondary transitions in the (n,#gamma#) data. The observed level densities and primary transition strengths are compared with statistical ...
Selective oxidation of n-butane and butenes over vanadium-containing catalysts
The oxidative dehydrogenation (OXDH) of n-butane, 1-butene, and trans-2-butene on different vanadia catalysts has been compared. MgO, alumina, and Mg-Al mixed oxides with Mg/(Al + Mg) ratios of 0.25 and 0.75 were used as supports. The catalytic data indicate that the higher the acid character of catalysts the lower is both the selectivity to C{sub 4}-olefins from n-butane and the selectivity to butadiene from both 1-butene or trans-2-butene. Thus, OXDH reactions are mainly observed from n-butane and butenes on basic catalysts. The different catalytic performance of both types of catalysts is a consequence of the isomerization of olefins on acid sites, which appears to be a competitive reaction with the selective way, i.e., the oxydehydrogenation process by a redox mechanism. Infrared spectroscopy data of 1-butene adsorbed on supported vanadium oxide catalysts suggest the presence of different adsorbed species. O-containing species (carbonyl and ...
2000-01-01
The variation of metallic particle size and sample porosity significantly alters the dynamic mechanical properties of high density granular composite materials processed using a cold isostatically pressed mixture of polytetrafluoroethylene (PTFE), aluminum (Al), and tungsten (W) powders. Quasistatic and dynamic experiments are performed with identical constituent mass fractions with variations in the size of the W particles and pressing conditions. The relatively weak polymer matrix allows the strength and fracture modes of this material to be governed by the granular type behavior of agglomerated metal particles. A higher ultimate compressive strength was observed in relatively high porosity samples with small W particles compared to those with coarse W particles in all experiments. Mesoscale granular force chains of the metallic particles explain this unusual phenomenon as observed in hydrocode simulations of a ...
2008-11-01
OZONE PRODUCTION IN URBAN PLUMES
International Nuclear Information System (INIS)
Ozone levels observed during a field campaign in Houston were significantly higher than that observed in Phoenix or Philadelphia. An examination of the slope of O(sub x) versus NO(sub z) in the urban plumes shows that NO(sub x) is used 2 to 3 times more efficiently in Houston as compared with Phoenix and Philadelphia. Representative values of OPEx are 7-12, 3, and 4, in Houston, Phoenix, and Philadelphia. Aircraft observations have been used to calculate P(O(sub 3))/P(NO(sub z)). Values in Houston are significantly higher than in Phoenix and Philadelphia. We show that P(O(sub 3))/P(NO(sub z)) is proportional to a VOC/NO(sub 2)-OH reactivity ratio. High values of P(O(sub 3))/P(NO(sub z)) in Houston are due to emissions of reactive olefins from the ship channel region. It is significant that high values of P(O(sub 3))/P(NO(sub z)) occur at NO(sub x) levels up to several 10's of ppb. Not only is the ...
Locally Optimally-emitting Clouds and the Narrow Emission Lines in Seyfert Galaxies
The narrow emission line spectra of active galactic nuclei are not accurately described by simple photoionization models of single clouds. Recent Hubble Space Telescope images of Seyfert 2 galaxies show that these objects are rich with ionization cones, knots, filaments, and strands of ionized gas. Here we extend to the narrow line region the ``locally optimally emitting cloud'' (LOC) model, in which the observed spectra are predominantly determined by powerful selection effects. We present a large grid of photoionization models covering a wide range of physical conditions and show the optimal conditions for producing many of the strongest emission lines. We show that the integrated narrow line spectrum can be predicted by an integration of an ensemble of clouds, and we present these results in the form of diagnostic line ratio diagrams making comparisons with observations. We also predict key diagnostic line ratios as a function of distance ...
1997-01-01
Kepler Mission Stellar and Instrument Noise Properties
Kepler Mission results are rapidly contributing to fundamentally new discoveries in both the exoplanet and asteroseismology fields. The data returned from Kepler are unique in terms of the number of stars observed, precision of photometry for time series observations, and the temporal extent of high duty cycle observations. As the first mission to provide extensive time series measurements on thousands of stars over months to years at a level hitherto possible only for the Sun, the results from Kepler will vastly increase our knowledge of stellar variability for quiet solar-type stars. Here we report on the stellar noise inferred on the timescale of a few hours of most interest for detection of exoplanets via transits. By design the data from moderately bright Kepler stars are expected to have roughly comparable levels of noise intrinsic to the stars and arising from a combination of fundamental ...
2011-01-01
KINEMATICS AT THE EDGE OF THE GALACTIC BULGE: EVIDENCE FOR CYLINDRICAL ROTATION
International Nuclear Information System (INIS)
We present new results from BRAVA, a large-scale radial velocity survey of the Galactic bulge, using M giant stars selected from the Two Micron All Sky Survey catalog as targets for the Cerro Tololo Inter-American Observatory 4 m Hydra multi-object spectrograph. The purpose of this survey is to construct a new generation of self-consistent bar models that conform to these observations. We report the dynamics for fields at the edge of the Galactic bulge at latitudes b = -8 deg. and compare to the dynamics at b = -4 deg. We find that the rotation curve V(r) is the same at b = -8 deg. as at b = -4 deg. That is, the Galactic boxy bulge rotates cylindrically, as do boxy bulges of other galaxies. The summed line-of-sight velocity distribution at b = -8 deg. is Gaussian, and the binned longitude-velocity plot shows no evidence for either a (disk) population with cold dynamics or for a (classical bulge) population with hot dynamics. The ...
2009-09-10
Integral Field Unit Observations of NGC 4302: Kinematics of the Diffuse Ionized Gas Halo
We present moderate resolution spectroscopy of extraplanar diffuse ionized gas (EDIG) emission in the edge-on spiral galaxy NGC 4302. The spectra were obtained with the SparsePak integral field unit (IFU) at the WIYN Observatory. The spectra are used to construct position-velocity (PV) diagrams at several ranges of heights above the midplane. Azimuthal velocities are directly extracted from the PV diagrams using the envelope tracing method, and indicate an extremely steep dropoff in rotational velocity with increasing height, with magnitude ~30 km/s/kpc. We find evidence for a radial variation in the velocity gradient on the receding side. We have also performed artificial observations of galaxy models in an attempt to match the PV diagrams. The results of a statistical analysis also favor a gradient of ~30 km/s/kpc. We compare these results with an entirely ballistic model of disk-halo flow, and find a strong dichotomy between the ...
2007-01-01
Independent Emission and Absorption Abundances for Planetary Nebulae
Emission-line abundances have been uncertain for more than a decade due to unexplained discrepancies in the relative intensities of the forbidden lines and weak permitted recombination lines in planetary nebulae (PNe) and H II regions. The observed intensities of forbidden and recombination lines originating from the same parent ion differ from their theoretical values by factors of more than an order of magnitude in some of these nebulae. In this study we observe UV resonance line absorption in the central stars of PNe produced by the nebular gas, and from the same ions that emit optical forbidden lines. We then compare the derived absorption column densities with the emission measures determined from ground-based observations of the nebular forbidden lines. We find for our sample of PNe that the collisionally excited forbidden lines yield column densities that are in basic agreement with the column ...
2008-01-01
EFFICIENCY OF OZONE PRODUCTION IN THE HOUSTON PLUME
International Nuclear Information System (INIS)
Ozone levels observed during a field campaign in Houston were significantly higher than that observed in Phoenix or Philadelphia. An examination of the slope of O(sub x) versus NO(sub z) in the urban plumes shows that NO(sub x) is used 2 to 3 times more efficiently in Houston as compared with Phoenix and Philadelphia. Representative values of OPEx are 7-12, 3, and 4, in Houston, Phoenix, and Philadelphia. Aircraft observations have been used to calculate P(O(sub 3))/P(NO(sub z)). Values in Houston are significantly higher than in Phoenix and Philadelphia. We show that P(O(sub 3))/P(NO(sub z)) is proportional to a VOC/NO(sub 2)-OH reactivity ratio. High values of P(O(sub 3))/P(NO(sub z)) in Houston are due to emissions of reactive olefins from the ship channel region. It is significant that high values of P(O(sub 3))/P(NO(sub z)) occur at NO(sub x) levels up to several 10's of ppb. Not only is the ...
An adaptive filter to approximate the Bayesian strategy for sonographic beamforming.
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 ...
2010-07-19
A variability study of the first catalog of gamma-ray sources on the 2.3 years AGILE data archive
AGILE pointed observations performed from July 9, 2007 to October 30, 2009 are a recent, high quality gamma-ray data archive for monitoring studies of medium to high brightness gamma-ray sources in the 30 MeV -50 GeV energy range. We present a variability study of the 1AGL sources over the complete AGILE pointed Observation Blocks (OBs) dataset. The first AGILE Gamma-Ray Imaging Detector (GRID) catalog (Pittori et al. 2009) included a significance-limited (4 sigma) sample of 47 sources (1AGL), detected with a conservative analysis over a first-year non-uniform sky coverage dataset. In this analysis we used data of an improved full Field of View (FOV) event filter, on a much larger (about 27.5 months) observation dataset, analyzing each OB separatedly. This data processing resulted in an improved source list as compared to the 1AGL one. We present here some results on the variability of some of these ...
2010-01-01
A numerical simulation of the evolution and fate of a FRI jet. The case of 3C 31
The evolution of FRI jets has been long studied in the framework of the FRI-FRII dichotomy. In this paper, we test the present theoretical and observational models via a relativistic numerical simulation of the jets in the radio galaxy 3C 31. We use the parameters derived from the modelling presented by \\cite{lb02a,lb02b} as input parameters for the simulation of the evolution of the source, thus assuming that they have not varied over the lifetime of the source. We simulate about 10 % of the total lifetime of the jets in 3C 31. Realistic density and pressure gradients for the atmosphere are used. The simulation includes an equation of state for a two-component relativistic gas that allows a separate treatment of leptonic and baryonic matter. We compare our results with the modelling of the observational data of the source. Our results show that the bow shock evolves self-similarly at a quasi-constant speed, with slight ...
2007-01-01
Energy Technology Data Exchange (ETDEWEB)
To determine a suitable combination of X-ray filter and tube kilovoltage for Fuji Computed Radiography (FCR), provide better detection of pulmonary nodules, and reduce patient exposure, we compared observer performance with different X-ray filters and tube voltages. Radiographs were obtained with a copper filter backed by aluminium, with a tungsten filter backed by yttrium and aluminium, and with a lead filter backed by yttrium and aluminium, at both 100 kVp and 135 kVp. Observer performance in detecting simulated lung nodules, which were placed on the posterior aspect of a chest phantom, was compared using receiver operating characteristic (ROC) techniques for each combination of the X-ray filter and tube voltage. The results of the study indicated that (1) nodule detection was superior for the images obtained with 135 kVq as compared with 100 kVp; (2) approximately equal detection ...
1994-10-01
International Nuclear Information System (INIS)
To determine a suitable combination of X-ray filter and tube kilovoltage for Fuji Computed Radiography (FCR), provide better detection of pulmonary nodules, and reduce patient exposure, we compared observer performance with different X-ray filters and tube voltages. Radiographs were obtained with a copper filter backed by aluminium, with a tungsten filter backed by yttrium and aluminium, and with a lead filter backed by yttrium and aluminium, at both 100 kVp and 135 kVp. Observer performance in detecting simulated lung nodules, which were placed on the posterior aspect of a chest phantom, was compared using receiver operating characteristic (ROC) techniques for each combination of the X-ray filter and tube voltage. The results of the study indicated that 1) nodule detection was superior for the images obtained with 135 kVq as compared with 100 kVp; 2) approximately equal detection ...
1994-01-01
Coir fibers received three treatments, namely washing with water, alkali treatment (mercerization) and bleaching. Treated fibers were incorporated in starch/ethylene vinyl alcohol copolymers (EVOH) blends. Mechanical and thermal properties of starch/EVOH/coir biocomposites were evaluated. Fiber morphology and the fiber/matrix interface were further characterized by scanning electron microscopy (SEM). All treatments produced surface modifications and improved the thermal stability of the fibers and consequently of the composites. The best results were obtained for mercerized fibers where the tensile strength was increased by about 53% as compared to the composites with untreated fibers, and about 33.3% as compared to the composites without fibers. The mercerization improved fiber-matrix adhesion, allowing an efficient stress transfer from the matrix to the fibers. The increased adhesion between fiber and matrix was also ...
2009-06-26
The aim of this study was to observe both the clinical signs and symptoms of wounds at risk of infection, that is critically colonised (biofilm infected) and antimicrobial-performance of an ionic silver alginate/carboxymethylcellulose (SACMC) dressing, in comparison with a non silver calcium alginate fibre (AF) dressing, on chronic venous leg and pressure ulcers. Thirty-six patients with venous or pressure ulcers, considered clinically to be critically colonised (biofilm infected), were randomly chosen to receive either an SACMC dressing or a non silver calcium AF dressing. The efficacy of each wound dressing was evaluated over a 4-week period. The primary study endpoints were prevention of infection and progression to wound healing. The SACMC group showed a statistically significant (P = 0.017) improvement to healing as indicated by a reduction in the surface area of the wound, over the 4-week study period, compared with AF controls. In ...
2010-05-31
The static indentation behavior of composite sandwich panels with thin quasi-isotropic skins
The quasi-static normal indentation of sandwich panels with quasi-isotropic laminated composite skins and honeycomb or foam cores, by spherical indentors, has been investigated using experiments and finite element analysis. The experimental program emphasized the effects of indentor size on the resulting load indentation responses, failure mechanisms in the skin and the core, and the measurement of contact areas between indentor and the target. The sandwich panels were indented up to the initiation of skin fracture and the resulting contact data was used to characterize contact power laws. A non-linear finite element model was developed based on the experimental observations to systematically explore the indentation behavior of diverse sandwich configurations and to investigate the contact pressure distributions. The finite element model was used as an experimental tool in the development of a simple non-dimensional semi-empirical model that was based on the ...
2001-01-01
Energy Technology Data Exchange (ETDEWEB)
Multi-dimensional modelling of two-phase flow requires accurate constitutive relationships for interfacial parameters such as interfacial heat transfer, void fraction distribution, interfacial area, etc. However, existing diagnostic systems for measurement of two-phase flow parameters have difficulty measuring two or three-dimensional void distributions required for determination of interfacial parameters. In this work, a Real-Time Neutron Radiography (RTNR) system is developed for non-intrusive measurement of two-phase flow parameters in nuclear fuel channels at low thermal neutron fluxes (on the order of 10{sup 6}n/cm{sup 2}-s). This advanced radiation technique has the advantage of measuring two-phase flow in 3 1/2 dimensions (x,{integral}dy,t) where the 1/2 dimension refers to an integrated or averaged space dimension. Pipe flow channels, annulus flow channels, MAPLE-type nuclear fuel flow channels, and CANDU-type nuclear fuel flow channels are investigated. Measurements of flow ...
1995-07-01
International Nuclear Information System (INIS)
Multi-dimensional modelling of two-phase flow requires accurate constitutive relationships for interfacial parameters such as interfacial heat transfer, void fraction distribution, interfacial area, etc. However, existing diagnostic systems for measurement of two-phase flow parameters have difficulty measuring two or three-dimensional void distributions required for determination of interfacial parameters. In this work, a Real-Time Neutron Radiography (RTNR) system is developed for non-intrusive measurement of two-phase flow parameters in nuclear fuel channels at low thermal neutron fluxes (on the order of 10"6n/cm"2-s). This advanced radiation technique has the advantage of measuring two-phase flow in 3 1/2 dimensions (x,#integral#dy,t) where the 1/2 dimension refers to an integrated or averaged space dimension. Pipe flow channels, annulus flow channels, MAPLE-type nuclear fuel flow channels, and CANDU-type nuclear fuel flow channels are investigated. Measurements of flow regime, void ...
1346-01-01
The risk of ano-genital malignancies in dialysis and transplant patients.
The incidence of anogenital malignancies is greatly increased in patients who have received a renal transplant, but this has not been well studied in patients receiving maintenance dialysis. Our aim was to assess the incidence of these malignancies in patients on dialysis and compare these to transplanted patients. The age standardized incidence ratio (SIR) for anogenital malignancies was calculated by comparing the observed number of malignancies to the expected number. The expected number was calculated by multiplying the age specific incidence rates for each malignancy by the person years at risk in 5-year age cohorts. Of 15,820 patients in the Australia and New Zealand data base, 8,215 had received a renal transplant. A total of 39,750 person years at risk were contributed by patients who had received a renal transplant, while 29,276 person years at risk were contributed by dialysis patients who had not received a renal ...
1994-02-01
Laser flash effects on chromatic discrimination in monkeys. Final report, April 1986-June 1987
Energy Technology Data Exchange (ETDEWEB)
Detecting a camouflaged target in a visually noisy background depends on the ability of the observer to discriminate the target from the surrounding terrain. Visible laser irradiation at less than damage levels can act as a masking source by compromising or reducing the observer's ability to resolve differences in the visual scene. Previous research has examined this concept by investigating laser flash effects on: acuity (size discrimination); tracking (motion discrimination); visual sensitivity (color); and contrast sensitivity functions (luminance contrast). In all cases, flashes from continuous-wave (CW) sources have proven more effective visually than pulsed (Q-switched) sources, when compared on peak-energy criteria (i.e., MPE), even though Q-switched lasers induce damage at lower energy doses. Additionally, the inherent safety of ultra-short laser pulses has been questioned. Past animal research has shown ...
1987-10-01
Thermal Hydraulics Analysis for the 3MW TRIGA MARK-II Research Reactor Under Transient Condition
International Nuclear Information System (INIS)
Some important thermal hydraulic parameters of the 3 MW TRIGA MARK-II research reactor operating under transient condition were investigated using two computer codes PULTRI and TEMPUL. Major transient parameters, such as, peak power and prompt energy released after pulse, maximum fuel and coolant temperature, surface heat flux, time and radial distribution of temperature within fuel element after pulse, fuel, fuel-cladding gap width variation, etc. were computer and compared with the experimental and operational values as reported in the safety Analysis Report (SAR). It was observed that pulsing of the reactor inserting an excess reactivity of $2.00 shoots the reactor power level to 854.353 MW compared to an experimental value of 852 MW; the maximum fuel temperature corresponding to this peak power was found to be 846.76"o C which is much less than the limiting maximum value of fuel temperature of 1150"0 C as reported in ...
1985-07-01
Polyp measurement based on CT colonography and colonoscopy: variability and systematic differences
Energy Technology Data Exchange (ETDEWEB)
To assess the variability and systematic differences in polyp measurements on optical colonoscopy and CT colonography. Gastroenterologists measured 51 polyps by visual estimation, forceps comparison and linear probe. CT colonography observers randomly assessed polyp size two-dimensionally (abdominal and intermediate window) and three-dimensionally (manually and semi-automatically). Linear mixed models were used to assess the variability and systematic differences between CT colonography and optical colonoscopy techniques. The variability of forceps and linear probe measurements was comparable and both showed less variability than measurement by visual assessment. Measurements by linear probe were 0.7 mm smaller than measurements by visual assessment or by forceps. The variability of all CT colonography techniques was lower than for measurements by forceps or visual assessment and sometimes lower (only 2D intermediate window and manual 3D) ...
2010-06-15
Energy Technology Data Exchange (ETDEWEB)
A comparative test in mice for pulmonary toxicity between butylated hydroxytoluene (2,6-di-tert.-butyl-4-methylphenol, BHT) and 2,6-di-tert.-butyl-4-(alpha, alpha, alpha-2H3)methylphenol (BHT-d3) showed a significantly lower toxic potency of the latter. The rate of in vitro BHT metabolism to 2,6-di-tert.-butyl-4-methylene-2,5-cyclohexadienone (BHT-QM) was slowed by deuterating BHT in the 4-methyl group. On the other hand, the rate of in vitro metabolism to 2,6-di-tert.-butyl-4-hydroxy-4-methyl-2,5-cyclohexadienone (BHT-OH) was increased with the deuteration. A similar isotope effect of the deuterium substitution on the in vivo metabolic rates of BHT was observed. These observations support the concept that the lung damage caused by BHT is mediated by BHT-QM. The pulmonary toxicity of 2-tert.-butyl-4-ethylphenol (4-EP) and their deuterated analogs was also compared. 2-tert.-Butyl-4-(1,1-2H2)ethylphenol ...
1983-06-30
New sets of cross sections for the production of krypton isotopes from targets of Rb, Sr, Y, and Zr were constructed primarily on the bases of experimental excitation functions for Kr production from Y. These cross sections were used to calculate galactic-cosmic-ray and solar-proton production rates for Kr isotopes in the moon. Spallation Kr data obtained from ilmenite separates of rocks 10017 and 10047 are reported. Production rates and isotopic ratios for cosmogenic Kr observed in ten well-documented lunar samples and in ilmenite separates and bulk samples from several lunar rocks with long but unknown irradiation histories were compared with predicted rates and ratios. The agreements were generally quite good. Erosion of rock surfaces affected rates or ratios for only near-surface samples, where solar-proton production is important. There were considerable spreads in predicted-to-observed production rates of /sup 83/Kr, ...
1979-01-01
Understanding of the volatility of GeO/sub 2/ in the presence of WO/sub 2/
Energy Technology Data Exchange (ETDEWEB)
The equilibria composition of the gaseous and the solid phase in the system GeO/sub 2//WO/sub 2/ is calculated with an improved thermodynamical program for temperatures 1100 < T < 1400 K and constant volume. By means of the results the experimental observed migration of GeO/sub 2/ in the presence of WO/sub 2/ in a temperature gradient T/sub 2/ ..-->.. T/sub 1/ (1200 ..-->.. 1100 K) in sealed evacuated silica tubes is due to a chemical transport with H/sub 2/ as the transporting agent. The H/sub 2/ is formed by H/sub 2/O which is desorbed by the quartz glass of the ampoules. The also observed volatility of WO/sub 2/ and its deposition in form of Ge/sub 0.75/W/sub 3/O/sub 9/ at the 'cold' end (T/sub 1/) of the tubes is performed by gaseous GeWO/sub 4/. The calculated and experimental transport rates are compared and discussed.
1983-08-01
Energy Technology Data Exchange (ETDEWEB)
Molar excess volumes, V{sup E}, molar excess enthalpies, H{sup E}, and speeds of sound data, u, of chloroform (i) + aniline or o-toluidine (j) binary mixtures have been measured as a function of composition at 308.15 K. Isentropic compressibility changes of mixing, {kappa}{sub S}{sup E} have been determined by employing speed of sound data. Topological investigations of V{sup E} data reveals that aniline, chloroform and o-toluidine are associated entities and these (i + j) mixtures contain a 1:1 molecular complex. The IR studies lend further support to the nature and extent of interaction for the proposed molecular entity in the mixtures. H{sup E} and {kappa}{sub S}{sup E} values have also been calculated by employing Moelwyn-Huggins concept [Polymer 12 (1971) 387] taking topology of the constituents of the mixtures. It has been observed that calculated H{sup E} and {kappa}{sub S}{sup E} values compare well with their corresponding experimental ...
2008-05-30
International Nuclear Information System (INIS)
Molar excess volumes, VE, molar excess enthalpies, HE, and speeds of sound data, u, of chloroform (i) + aniline or o-toluidine (j) binary mixtures have been measured as a function of composition at 308.15 K. Isentropic compressibility changes of mixing, ?SE have been determined by employing speed of sound data. Topological investigations of VE data reveals that aniline, chloroform and o-toluidine are associated entities and these (i + j) mixtures contain a 1:1 molecular complex. The IR studies lend further support to the nature and extent of interaction for the proposed molecular entity in the mixtures. HE and ?SE values have also been calculated by employing Moelwyn-Huggins concept [Polymer 12 (1971) 387] taking topology of the constituents of the mixtures. It has been observed that calculated HE and ?SE values compare well with their corresponding experimental values. The observed VE, HE and ?SE data have also been ...
2008-05-30
Energy Technology Data Exchange (ETDEWEB)
An ASTER (advanced spaceborne thermal emission and reflection radiometer) is one of the image sensors. It is to be installed in an earth survey polar orbit platform satellite, EOS-AM1, which is to be launched in 1998, and it is going to start its operation. Data observed by the thermal infrared remote sensing of ASTER include the spectral emissivity, and the spectral emission reflectivity which is expressed by the function of temperature. It is required to overcome technical problems how to extract the spectral emissivity from the observed data. The spectral emissivity extracted from the remote sensing data by the MMD method, measured for samples collected in Cuprite area, Nevada, and/or measured at sampled points were compared to each other and discussed. The hemisphere spectral reflectivity, which is indirect spectral emissivity, agreed well with the direct spectral emissivity. Data suggesting the establishment of ...
1996-10-01
The pre-outburst flare of the A 0535+26 August/September 2005 outburst
We study the spectral and temporal behavior of the High Mass X-ray Binary A 0535+26 during a `pre-outburst flare' which took place ~5 d before the peak of a normal (type I) outburst in August/September 2005. We compare the studied behavior with that observed during the outburst. We analyse RXTE observations that monitored A 0535+26 during the outburst. We complete spectral and timing analyses of the data. We study the evolution of the pulse period, present energy-dependent pulse profiles both at the initial pre-outburst flare and close to outburst maximum, and measure how the cyclotron resonance-scattering feature (hereafter CRSF) evolves. We present three main results: a constant period P=103.3960(5)s is measured until periastron passage, followed by a spin-up with a decreasing period derivative of Pdot=(-1.69+/-0.04)x10^(-8)s/s at MJD 53618, and P remains constant again at the end of the main outburst. The spin-up ...
2008-01-01
We investigate the physics of the lightest CP-even MSSM Higgs boson at the Tevatron, the LHC, a linear e+e- collider, a gamma gamma collider and a mu+mu- collider. The analysis is performed in the three most prominent soft SUSY-breaking scenarios, mSUGRA, mGMSB and mAMSB. For all colliders the observability and parameter regions with suppressed production cross sections (compared to a SM Higgs boson with the same mass) are investigated. For the lepton and photon colliders the potential is analyzed of precision measurements of the branching ratios of the light CP-even Higgs boson for obtaining indirect bounds on the mass of the CP-odd Higgs boson and the high-energy parameters of the soft SUSY-breaking scenarios. In regions of the parameter space where the LHC can detect the heavy Higgs bosons, precision measurements of the properties of the light Higgs boson at the linear collider can provide valuable information for distinguishing between the ...
2003-01-01
Energy Technology Data Exchange (ETDEWEB)
The generation of available potential energy (APE) in the space-time domain in January and July in a present-day climate simulation with a general circulation model (GCM) is compared with observations. An attempt is made to explain the differences. The generation is computed from the fields of diabatic heating and temperature. The heating is computed with the residual method, using UKMO (United Kingdom Meteorological Office) Unified Model GCM circulation data and ECMWF (European Centre for Medium-Range Weather Forecasts) initialized analyses for the period 1989-1992. The global value of the generation of APE is about 35% larger in the GCM climate than the value computed from the analyses. This is mainly because the generation of transient eddy APE in the GCM is too large, due to the more than 40% too large generation of transient eddy kinetic energy by baroclinic processes. In most of the extratropics the local contribution to the generation of ...
1995-03-01
Energy Technology Data Exchange (ETDEWEB)
The sedimentary geometry is determined by several types of stratigraphic surfaces: transgressive surfaces (TS), maximum flooding surfaces (MFS) and downward shift surfaces (DS). They are organized hierarchically into major and minor surfaces from the facies stacking-pattern. These surfaces which are observable on well logs and cores structure the sedimentary architecture and are, therefore, the best candidates to form major seismic reflectors. The well (logs and cores) to seismic (surface seismic) passage involves inherently a change of observation scale. That is from a high resolution sequence stratigraphy (metric to pluri-metric) to a sequence stratigraphy s.l. (decametric to pluri-decametric). This passage is composed of two phases. The first phase consists of the validation of density and sonic logs whose product corresponds to the acoustic impedance. The second phase allows for the modelling of the geological cross section of a field in a ...
1996-12-31
International Nuclear Information System (INIS)
We present 14 years of contemporaneous photometric and spectroscopic observations of 28 solar analog stars, taken with the Tennessee State University Automatic Photometric Telescopes at Fairborn Observatory and the Solar-Stellar Spectrograph at Lowell Observatory. These are the best observed and most nearly Sun-like of the targets in our magnitude-limited (V #<=# 7.5) sample. The correlations between luminosity and activity reveal the expected inverse activity-brightness correlations for active stars. Strong direct correlations between activity and brightness are not prevalent for the less active solar age stars, but are precision limited. The Sun does not appear to have unusually low photometric variability when compared with the most Sun-like inactive solar analogs. We present evidence that the activity index R'_H_K is not a good discriminant of Maunder Minimum candidate stars. On the basis of a star that appears to ...
2009-07-01
Superplastic deformation of nitrogen-rich Ca-#alpha#-sialon ceramics
International Nuclear Information System (INIS)
Nitrogen-rich Ca-#alpha#-sialon ceramics, prepared with CaH_2 as one of the starting powders, were compressively deformed in spark plasma sintering equipment. Compared with the oxygen-rich Ca-#alpha#-sialons, increasing onset deformation temperatures (about 150 K higher) were observed for nitrogen-rich Ca-#alpha#-sialons deformed at a rate of 2 x 10"-"3 s"-"1. High hardness (H_V_1_0 = 18-20 GPa) and toughness (K_I_C = 4-7 MPa m"1"/"2) were maintained after the deformation. Anisotropic grain growth was found to take place during deformation, resulting in anisotropic microstructures, containing coarse and elongated grains. The observed differences in deformation behaviour and properties between nitrogen-rich and oxygen-rich Ca-#alpha#-sialons are, as indicated by transmission electron microscopy and electron energy loss spectroscopy analysis, attributed to the presence of reduced amounts of a nitrogen-rich grain-boundary ...
2008-02-25
Sunyaev-Zeldovich profiles for clusters and groups of galaxies
The Sunyaev-Zeldovich (SZ) effect gives a measure of the thermal energy and electron pressure in groups and clusters of galaxies. In the near future SZ surveys will map hundreds of systems, shedding light on the pressure distribution in the systems. The thermal energy is related to the total mass of a system of galaxies, but it is only a projection that is observed through the SZ effect. A model for the 3D distribution of pressure is needed to link the SZ signal to the total mass of the system. In this work we construct an empirical model for the 2D and 3D SZ profile, and compare it to a set of realistic high resolution SPH simulations of galaxy clusters and groups, and to a stacked SZ profile for massive clusters derived from WMAP data. Furthermore, we combine observed temperature profiles with dark matter potentials to yield an additional constraint, under the assumption of hydrostatic equilibrium. We find a very tight ...
2007-01-01
The strain dependence of Si-Ge interdiffusion in epitaxial Si/Si{sub 1-y}Ge{sub y}/Si heterostructures on relaxed Si{sub 1-x}Ge{sub x} substrates has been studied using secondary ion mass spectrometry, Raman spectroscopy, and simulations. At 800 and 880 deg. C, significantly enhanced Si-Ge interdiffusion is observed in Si/Si{sub 1-y}Ge{sub y}/Si heterostructures (y=0.56, 0.45, and 0.3) with Si{sub 1-y}Ge{sub y} layers under compressive strain of -1%, compared to those under no strain. In contrast, tensile strain of 1% in Si{sub 0.70}Ge{sub 0.30} layer has no observable effect on interdiffusion in Si/Si{sub 0.70}Ge{sub 0.30}/Si heterostructures. These results are relevant to the device and process design of high mobility dual channel and heterostructure-on-insulator metal oxide semiconductor field effect transistors.
2006-01-02
We report on the spectral cross-calibration results of the Konus-Wind, the Suzaku/WAM, and the Swift/BAT instruments using simultaneously observed gamma-ray bursts (GRBs). This is the first attempt to use simultaneously observed GRBs as a spectral calibration source to understand systematic problems among the instruments. Based on these joint spectral fits, we find that 1) although a constant factor (a normalization factor) agrees within 20% among the instruments, the BAT constant factor shows a systematically smaller value by 10-20% compared to that of Konus-Wind, 2) there is a systematic trend that the low-energy photon index becomes steeper by 0.1-0.2 and Epeak becomes systematically higher by 10-20% when including the BAT data in the joint fits, and 3) the high-energy photon index agrees within 0.2 among the instruments. Our results show that cross-calibration based on joint spectral analysis is an important step to ...
2010-01-01
DEFF Research Database (Denmark)
Connective tissue in biopsy specimens taken from the lower part of the uterine cervix in 40 pregnant women at various gestational ages was compared to that in similar biopsy specimens from 15 nonpregnant women. The concentrations of collagen, sulfated glycosaminoglycans, and hyaluronic acid decreased during pregnancy. At the gestational age of 10 weeks, the collagen concentration was 70%, and at term 30%, of that in the nonpregnant cervix. After delivery, no further decrease was observed. The extractability of collagen increased during pregnancy, as well as during labor. Also, the water concentration increased. An increase in the collagenolytic activity was observed with advancing gestational age. The 2,4-dinitrophenyl-Pro-Gln-Gly-Ile-Ala-Gly-Gin-D-Arg hydrolytic activity (collagenase) and the concentration of leukocyte elastase increased gradually by a factor of 10. The physiologic importance of the collagen was also ...
1983-01-01
Energy Technology Data Exchange (ETDEWEB)
The Atmospheric Radiation Monitor (ARM) uninhabited aerospace vehicle (UAV) program aims to develop measurement techniques and instruments suitable for a new class of high altitude, long endurance UAVs while supporting the climate community with valuable data sets. Using the Scaled Composites Proteus aircraft, ARM UAV participated in Mixed-Phase Arctic Cloud Experiment (M-PACE), obtaining unique data to help understand the interaction of clouds with solar and infrared radiation. Many measurements obtained using the Proteus were coincident with in-situ observations made by the UND Citation. Data from M-PACE are needed to understand interactions between clouds, the atmosphere and ocean in the Arctic, critical interactions given large-scale models suggest enhanced warming compared to lower latitudes is occurring.
2005-03-18
Pharmacokinetics of buspirone as determined by ex vivo (/sup 3/H)-DPAT binding
Energy Technology Data Exchange (ETDEWEB)
Ex vivo (/sup 3/H)-8-hydroxy-2-(di-n-propylamino)-tetraline ((/sup 3/H)-DPAT) binding to the hippocampus has been utilized to determine the pharmacokinetic parameters of buspirone after i.v. and oral administration of this drug to rats. Intravenous buspirone rapidly penetrated the brain as demonstrated by a maximum inhibition of (/sup 3/H)-DPAT binding at 1 min. Elimination of drug from the brain was biphasic, with a first component half-life of 24.8 min and a second component half-life of 96 min. Oral buspirone at 3 times the i.v. dose produced less than one-third the maximum inhibition of (/sup 3/H)-DPAT binding compared to that observed with i.v. buspirone. The pharmacokinetic parameters of buspirone observed in the present study are in agreement with those reported previously. Thus, the ex vivo binding assay could be utilized to determine the bioavailability of the drug to the brain, and its duration of action. 20 ...
1988-01-01
Energy Technology Data Exchange (ETDEWEB)
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 either side of the ...
1999-05-14
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 either side of the ...
1999-05-14
On the temperature dependence of the magnetic excitations
International Nuclear Information System (INIS)
We compare experimental data for temperature dependence of the magnetic order parameter and the magnetic excitations (spin waves) in materials with a quenched orbital moment and a well-defined spin quantum number. It is observed that the thermal decrease of the two quantities proceeds according to the same analytical function of the type y(T)=1-cT"#epsilon# with an identical exponent #epsilon#. This power function applies not only asymptotically for T->0 but holds over a wide temperature range. The exponent #epsilon# is universal, i.e. independent of spin order type and lattice symmetry and depends only on the dimensionality of the relevant interactions and on whether the spin quantum number is integer or half-integer. The different T"#epsilon# functions are identified as representations of stable universality classes. The fact that order parameter and magnetic excitations follow the same T"#epsilon# function shows that the two quantities ...
2005-07-15
Observations of toroidal and poloidal rotation in the high-beta tokamak Torus II
The macroscopic rotation of plasma in a toroidal containment device is an important feature of the equilibrium. Toroidal and polidal rotation in the high-beta tokamak Torus II is measured experimentally by examining the Doppler shift of the 4685.75 A He II line emitted from the plasma. The toroidal flow at an average velocity of 1.6 x 10/sup 6/ cm/sec, a small fraction of the ion thermal speed, moves in the same direction as the toroidal-plasma current. The poloidal flow follows the ion diamagnetic current direction, also at an average speed of 1.6 x 10/sup 6/ cm/sec. In view of certain ordering parameters, the toroidal flow is compared with predictions from neoclassical theory in the collisional, Pfirsch-Schluter regime. The poloidal motion, however, results from an E x B drift in a positive radial electric field, approaching a stable ambipolar state. This radial electric field is determined from theory by using the measured poloidal velocity. Mechanisms for the ...
1983-01-01
Observations of toroidal and poloidal rotation in the high beta tokamak Torus II
The macroscopic rotation of plasma in a toroidal containment device is an important feature of the equilibrium. Toroidal and poloidal rotation in the high beta tokamak Torus II is measured experimentally by examining the Doppler shift of the 4685.75 A He II line emitted from the plasma. The toroidal flow at an average velocity of 1.6 x 10/sup 6/ cm/sec, a small fraction of the ion thermal speed, moves in the same direction as the toroidal plasma current. The poloidal flow follows the ion diamagnetic current direction, also at an average speed of 1.6 x 10/sup 6/ cm/sec. In view of certain ordering parameters, the toroidal flow is compared with predictions from neoclassical theory in the collosional, Pfirsch-Schluter regime. The poloidal motion, however results from an E x B drift in a positive radial electric field, approaching a stable ambipolar state. This radial electric field is determined from theory by using the measured poloidal velocity. Mechanisms for the ...
1983-01-01
Observation of high permittivity in Ho substituted BaZr_0_._1Ti_0_._9O_3 ceramics
International Nuclear Information System (INIS)
The authors observed an extremely high permittivity (#approx#35 000 at T_C) in barium zirconate titanate (BaZr_0_._1Ti_0_._9O_3) ceramics with holmium substitution (1-5 mol %) in Ba site. Careful microstructural investigation and energy dispersive spectroscopy analysis of the 1-2 mol % of Ho substituted ceramics showed the enrichment of a Ho-phase along the grain boundaries with a composition close to the Ho_2Ti_2O_7 pyrochlore. The formation of Ho rich phase resulted in the Maxwell-Wagner polarization mechanism, which leads to this unusually high permittivity. Ceramics with 3 mol % or higher Ho content showed lesser permittivity values compared to 1-2 mol %, probably due to the increase in pyrochlore phase. These high dielectric constant ceramics are useful in nanoscale devices.
2007-07-09
Neutron scattering studies of mixed-valence semiconductors
Energy Technology Data Exchange (ETDEWEB)
Neutron scattering experiments on the mixed-valence (MV) compounds SmB{sub 6} are reported. The inelastic magnetic response of SmB{sub 6} at T = 2 K, measured on a double-isotope single crystal,displays a strongly damped peak at 35 meV corresponding to the inter multiplet transition of Sm{sup 2+}. At lower energies ( h.{omega} {approx_equal} 14 meV), a narrow magnetic excitation is observed, with remarkable scattering-vector and temperature dependences of its intensity. This novel feature is discussed in terms of recent theoretical works describing the formation of an anisotropic local bound state in semiconducting MV materials. If the average samarium valence is decreased by substituting La for Sm, a peak is found to appear at high energies. The elastic magnetic form factor of SmB{sub 6} was determined using polarised neutrons and no significant difference is observed in its Q-dependence with respect to that of pure divalent samarium. This ...
1994-12-31
Microstructural evaluation of as-solidified and heat-treated [gamma]-TiAl based powders
Energy Technology Data Exchange (ETDEWEB)
Powders with nominal compositions (in atomic percent) Ti-48Al and Ti-48Al-2Nb-2Cr were prepared by the plasma rotating electrode process (PREP) and gas atomization (GA) techniques. As-solidified and heat-treated (1000degC per 3 h) powder samples were examined by metallography, scanning electron microscopy, X-ray diffraction and transmission electron microscopy. The microstructures of the powders were characterized as a function of atomization technique, alloy content, powder particle size (solidification rate) and thermal history. All of the as-solidified powders were comprised of disordered [alpha], and ordered [alpha][sub 2]-Ti[sub 3]Al and [gamma]-TiAl. For both alloys, a larger volume fraction of [alpha] and [alpha][sub 2] was observed in the PREP powders relative to GA powders of comparable size. Additionally, for both alloys and both atomization techniques, the volume fraction of [alpha][sub 2] was observed to ...
1992-05-15
International Nuclear Information System (INIS)
The level structure and configurations of "2"1"6At have been studied by observing the alpha decay of "2"2"0Fr, which is in secular equilibrium with "2"2"4Ac. Six of the 16 observed states are tentatively assigned to the configuration #pi#(h_9_/_2)"3#upsilon#(g_9_/_2)"5, and four to the mixed configuration #pi#(h_9_/_2)"3#upsilon#(g_9_/_2)"4(i_1_1_/_2)+#pi#(h_9_/_2)"2(f _7_/_2)#upsilon#(g_9_/_2)"5. These two configurations in "2"1"6At are compared with the corresponding configurations in "2"1"2Bi and "2"1"0Bi. The shape transitions are traced from the quadrupole-octupole deformed "2"2"4Ac through "2"2"0Fr and "2"1"6At, to "2"1"2Bi, described by the spherical shell model, using the alpha decay sequence beginning with "2"2"8Pa. copyright 1996 The American Physical Society.
InAIP/InAlGaP distributed Bragg reflectors for visible vertical cavity surface-emitting lasers
International Nuclear Information System (INIS)
Distributed Bragg reflectors (DBRs) composed of In_0_._5Al_0_._5P/In_0_._5(Al_yGa_1_-_y)_0_._5P quarter-wave layers have been prepared using metalorganic vapor phase epitaxy. The structures were grown over a wide range of high-index layer composition (0#<=#y#<=#0.6) and peak reflectivity wavelength (720 nm#<=##lambda##<=#565 nm, covering the spectrum from deep red to green). In all cases observed and calculated reflectance spectra were in excellent agreement. Using these DBRs, an undoped all-phosphide visible vertical cavity surface-emitting laser structure was grown. Under pulsed optical excitation at room temperature, lasing was obtained at a wavelength of #lambda##approx#670 nm, with a threshold power density comparable to that observed from similar structures prepared using AlAs/AlGaAs DBRs.
IR double-resonance spectroscopy applied to the 4-aminophenol(H{sub 2}O){sub 1} cluster
Energy Technology Data Exchange (ETDEWEB)
The IR double-resonance techniques IR/R2PI (infrared/resonant 2-photon ionization), IR/PIRI (infrared-photo-induced Rydberg ionization) and IR-photodissociation spectroscopy are valuable tools to investigate structure, vibrations, and dynamical processes of neutral and ionic hydrogen-bonded clusters containing aromatic molecules. In this paper we report on the application of the IR double-resonance techniques to determine the NH and OH stretching vibrations of 4-aminophenol and 4-aminophenol(H{sub 2}O){sub 1}, both in the neutral (S{sub 0}) and ionic (D{sub 0}) ground state. All vibrational frequencies obtained for 4-aminophenol and the cluster are compared with the values obtained from ab initio and DFT calculations. In the S{sub 0} state, a trans-linear arrangement of 4-aminophenol(H{sub 2}O){sub 1} is obtained containing an O-H. O hydrogen bond. In the D{sub 0} state an overlay of two spectra can be observed resulting from the trans-linear ...
2001-03-01
High Velocity Molecular Outflows In Massive Cluster Forming Region G10.6-0.4
We report the arcsecond resolution SMA observations of the $^{12}$CO (2-1) transition in the massive cluster forming region G10.6-0.4. In these observations, the high velocity $^{12}$CO emission is resolved into individual outflow systems, which have a typical size scale of a few arcseconds. These molecular outflows are energetic, and are interacting with the ambient molecular gas. By inspecting the shock signatures traced by CH$_{3}$OH, SiO, and HCN emissions, we suggest that abundant star formation activities are distributed over the entire 0.5 pc scale dense molecular envelope. The star formation efficiency over one global free-fall timescale (of the 0.5 pc molecular envelope, $\\sim$10$^{5}$ years) is about a few percent. The total energy feedback of these high velocity outflows is higher than 10$^{47}$ erg, which is comparable to the total kinetic energy in the rotational motion of the dense molecular envelope. From ...
2010-01-01
Expert overseer for mass spectrometer system
Energy Technology Data Exchange (ETDEWEB)
This patent describes an expert overseer for the operation and real-time management of a mass spectrometer and associated laboratory equipment. The overseer is a computer-based expert diagnostic system implemented on a computer separate from the dedicated computer used to control the mass spectrometer and produce the analysis results. An interface links the overseer to components of the mass spectrometer, components of the laboratory support system, and the dedicated control computer. Periodically, the overseer polls these devices and as well as itself. These data are fed into an expert portion of the system for real-time evaluation. A knowledge base used for the evaluation includes both heuristic rules and precise operation parameters. The overseer also compares current readings to a long-term database to detect any developing trends using a combination of statistical and heuristic rules to evaluate the results. The overseer has the capability to alert lab ...
1991-06-18
Expert overseer for mass spectrometer system
International Nuclear Information System (INIS)
This patent describes an expert overseer for the operation and real-time management of a mass spectrometer and associated laboratory equipment. The overseer is a computer-based expert diagnostic system implemented on a computer separate from the dedicated computer used to control the mass spectrometer and produce the analysis results. An interface links the overseer to components of the mass spectrometer, components of the laboratory support system, and the dedicated control computer. Periodically, the overseer polls these devices and as well as itself. These data are fed into an expert portion of the system for real-time evaluation. A knowledge base used for the evaluation includes both heuristic rules and precise operation parameters. The overseer also compares current readings to a long-term database to detect any developing trends using a combination of statistical and heuristic rules to evaluate the results. The overseer has the capability to alert lab ...
1989-04-04
The purpose of this study was to prepare recombinant human epidermal growth factor (rhEGF) collagen sponges for topical applications and investigate the effects of different types of crosslinked collagen sponges as platforms for the controlled release of rhEGF. The microstructure and the drug release rates of collagen sponges were modified through treatment with different types (glutaraldehyde (GTA), genipin and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC)), different concentrations of crosslinking agents and various preparation conditions. A controlled release profile was observed for the crosslinked collagen sponges as compared to the non-crosslinked ones. The results indicated that the GTA crosslinked sponges have the most potent controlling effect. As the amount of GTA increased, a greater rigidity of the collagen sponge structure combined with a lower hydrophilicity was observed, leading to a decreased drug ...
2007-10-04
Energy Technology Data Exchange (ETDEWEB)
To assess the potential of CT in evaluating the histological severity of acute appendicitis in comparison with surgical and pathological findings. The CT images of 75 patients with surgically proven appendicitis, including 10 cases of catarrhal, 34 of phlegmonous, and 31 of gangrenous appendicitis, were retrospectively analyzed for the following five CT findings: hazy periappendiceal densities, enlarged appendix, increased enhancement of the appendiceal wall, increased enhancement of the periappendiceal intestinal wall, and deficiency of the appendiceal wall. By comparing all the CT findings and the pathological severity of appendicitis (catarrhal, phlegmonous, and gangrenous), the prevalence of the five CT findings was calculated for each pathological category. Abnormal CT findings were noted in only one case of catarrhal appendicitis. Increased enhancement of the appendiceal wall was observed in all 29 cases of phlegmonous appendicitis ...
2001-08-01
Effect of the ASARCO smelter shutdown on the acidity of rainfall in the Puget sound area
The influence of the sulfur dioxide emissions from a large copper smelter in Tacoma, Washington, USA, was studied by measuring the chemical composition of rainwater collected upwind and downwind of the source, before and after permanent closure of the smelter in 1985. Data analysis was based on a statistical model that accounted for variability associated with location of 25 sampling sites within three geographic regions, smelter operation, ten individual rain events observed over 2 years, and measurement uncertainty. After smelter closure, the upwind-downwind differences in mean hydrogen ion and excess sulfate ion concentrations within a 600 km/sup 2/ region extending to 25 km downwind of the source had decreased significantly compared to the pre-closure value. No significant decreases in mean ion concentrations were observed farther downwind in the Seattle, urban area. During five events sampled prior to smelter closure, ...
1988-04-01
Energy Technology Data Exchange (ETDEWEB)
Experimental discussions were given on effect of V and W addition on the high temperature strength properties of 12% Cr-15% Mn austenite steels. The test samples were added with W at 0% to 3.5% and V at 0% to 0.5% in addition to C and N, and were given aging treatment or solution treatment. This paper describes the following matters on the results of high-temperature strength measurements and structural observation: A remarkable trend was observed that M23 Cb type carbides precipitate in the aging treatment, wherein aging hardening appears prominently which is attributable to ultra-fine deposits of vanadium nitride (VN) in the V-added material; the V addition is very effective in increasing the high-temperature tensile strength and creep fracture strength as compared with single W addition, wherein the said carbides that accelerate the precipitation as a result of the V addition make a large contribution, in addition to ...
1992-11-01
Energy Technology Data Exchange (ETDEWEB)
The real-time neutron radiography system of the Kyoto University Reactor (KUR) has been practically applied to penetrating the side plates containing boron burnable poison to test MTR type reactor fuels and to investigation of moving objects. Compared with the image obtained by the direct film method, however, the image from the TV system is in low-contrast and poor-resolution. This paper presents some digital processing approaches to improve the image quality and the neutron TV system is successfully applied to neutron computed tomography (NCT). The frame summing technique is effective to increase the quality of the radiographic image. By using the NTV system in NCT, the projection data are able to be acquired in a single measurement as observing the projection image on a CRT monitor. Two weighting functions based on the Fourier-convolution algorithm are employed to obtain the reconstructed image. The image quality could be satisfactory to ...
1984-09-01
International Nuclear Information System (INIS)
The real-time neutron radiography system of the Kyoto University Reactor (KUR) has been practically applied to penetrating the side plates containing boron burnable poison to test MTR type reactor fuels and to investigation of moving objects. Compared with the image obtained by the direct film method, however, the image from the TV system is in low-contrast and poor-resolution. This paper presents some digital processing approaches to improve the image quality and the neutron TV system is successfully applied to neutron computed tomography (NCT). The frame summing technique is effective to increase the quality of the radiographic image. By using the NTV system in NCT, the projection data are able to be acquired in a single measurement as observing the projection image on a CRT monitor. Two weighting functions based on the Fourier-convolution algorithm are employed to obtain the reconstructed image. The image quality could be satisfactory to ...
1984-01-01
Energy Technology Data Exchange (ETDEWEB)
A C{sub 60} {sup +} primary ion source has been coupled to an ion microscope secondary ion mass spectrometry (SIMS) instrument to examine sputtering of silicon with an emphasis on possible application of C{sub 60} {sup +} depth profiling for high depth resolution SIMS analysis of silicon semiconductor materials. Unexpectedly, C{sub 60} {sup +} SIMS depth profiling of silicon was found to be complicated by the deposition of an amorphous carbon layer which buries the silicon substrate. Sputtering of the silicon was observed only at the highest accessible beam energies (14.5 keV impact) or by using oxygen backfilling. C{sub 60} {sup +} SIMS depth profiling of As delta-doped test samples at 14.5 keV demonstrated a substantial (factor of 5) degradation in depth resolution compared to Cs{sup +} SIMS depth profiling. This degradation is thought to result from the formation of an unusual platelet-like grain structure on the SIMS crater bottoms. Other ...
2006-07-30
Delta Scorpii 2011 periastron: worldwide observational campaign and preliminary photometric analysis
Delta Scorpii is a double giant Be star in the forefront of the Scorpio, well visible to the naked eye, being normally of magnitude 2.3. In the year 2000 its luminosity rose up suddenly to the magnitude 1.6, changing the usual aspect of the constellation of Scorpio. This phenomenon has been associated to the close periastron of the companion, orbiting on a elongate ellipse with a period of about 11 years. The periastron, on basis of high precision astrometry, is expected to occur in the first decade of July 2011, and the second star of the system is approaching the atmosphere of the primary, whose circumstellar disk has a H-alpha diameter of 5 milliarcsec, comparable with the periastron distance. The preliminary results of a photometric campaign, here presented in the very days of the periastron, show an irregular behavior of the star's luminosity, which can reflect some shocks between material around the two stars. The small luminosity increasement detected in the ...
2011-01-01
International Nuclear Information System (INIS)
The electronic structure and surface interactions vapor-deposited Cu on single-crystal and polycrystalline Bi_2Ca/sub 1+//sub x//sub Sr>2-//sub x//sub Cu>2/O/sub 8+//sub y/ were studied using x-ray photoelectron spectroscopy. The results are compared to the Cu/YBa_2Cu_3O/sub 7-//sub x/ interface. Changes in the Cu 2p satellite emission indicate that the Cu adatoms do not disrupt Bi_2Ca/sub 1+//sub x/Sr/sub 2-//sub x/Cu_2O/sub 8+//sub y/ as extensively as YBa_2Cu_3O/sub 7-//sub x/. However, deposition of Cu induces changes in the Bi environment in the superconductor, and surface segregation of Bi metal was observed at high coverages. Core-level attenuation results suggests minimal outdiffusion of oxygen, in contrast with what is observed for Cu/YBa_2Cu_3O/sub 7-//sub x/.
5545-01-01
Energy Technology Data Exchange (ETDEWEB)
A Real-Time Neutron Radiography (RTNR) system and a high speed X-ray Computed tomography (X-CT) system are compared for measurement of two-phase flow. Each system is used to determine the flow regime, and the void fraction distribution in a vertical annulus flow channel. A standard optical video system is also used to observe the flow regime. The annulus flow channel is operated as a bubble column and measurements obtained for gas flow rates from 0.0 to 30.01/min. The flow regimes observed by all three measurement systems through image analysis shows that the two-dimensional void fraction distribution can be obtained. The X-CT system is shown to have a superior temporal resolution capable of resolving the void fraction distribution in an (r,{theta}) plane in 33.0 ms. Void fraction distribution for bubbly flow and slug flow is determined.
1995-09-01
International Nuclear Information System (INIS)
A Real-Time Neutron Radiography (RTNR) system and a high speed X-ray Computed tomography (X-CT) system are compared for measurement of two-phase flow. Each system is used to determine the flow regime, and the void fraction distribution in a vertical annulus flow channel. A standard optical video system is also used to observe the flow regime. The annulus flow channel is operated as a bubble column and measurements obtained for gas flow rates from 0.0 to 30.01/min. The flow regimes observed by all three measurement systems through image analysis shows that the two-dimensional void fraction distribution can be obtained. The X-CT system is shown to have a superior temporal resolution capable of resolving the void fraction distribution in an (r,#theta#) plane in 33.0 ms. Void fraction distribution for bubbly flow and slug flow is determined.
1995-09-01
Based on studies on the genetic and molecular basis of Shigella flexneri invasive properties, we have constructed and evaluated a double mutant of S. flexneri serotype 5 for utilization as a live attenuated oral vaccine against shigellosis. The first mutation, icsA, blocks intracellular spread of bacteria as well as cell-to-cell infection. It affects the capacity of the invasive pathogen to form large abscesses in epithelia. The second mutation, iuc, eliminates production of the siderophore aerobactin thus impairing growth of the bacterium within tissues. This double mutant, SC5700 appeared safe when administered intragastrically to macaque monkeys as three doses (5 x 10(10) c.f.u. each) at weekly intervals. Protection against a challenge by the wild type isolate (M90T) was observed 4 weeks after the last vaccine inoculation. Duration of carriage was considerably reduced as compared to the control group in which all animals had developed severe ...
1989-10-01
Comprehensive simulations of superhumps
(Abridged) We use 3D SPH calculations with higher resolution, as well as with more realistic viscosity and sound-speed prescriptions than previous work to examine the eccentric instability which underlies the superhump phenomenon in semi-detached binaries. We illustrate the importance of the two-armed spiral mode in the generation of superhumps. Differential motions in the fluid disc cause converging flows which lead to strong spiral shocks once each superhump cycle. The dissipation associated with these shocks powers the superhump. We compare 2D and 3D results, and conclude that 3D simulations are necessary to faithfully simulate the disc dynamics. We ran our simulations for unprecedented durations, so that an eccentric equilibrium is established except at high mass ratios where the growth rate of the instability is very low. Our improved simulations give a closer match to the observed relationship between superhump period excess and binary ...
2007-01-01
Energy Technology Data Exchange (ETDEWEB)
The circulation in microvascularized rib grafts has been compared with that in conventional rib grafts and in those augmented by a direct vascular bundle implantation into the bone grafts. A new experimental model has been designed to correlate vascular perfusion, bone scan patterns, tetracycline labeling, and histological findings in these bone grafts. Posterior microvascularized rib grafts were found to have a circulatory pattern identical to that of the normal rib. Failed microvascularized rib grafts were revascularized more slowly than conventional rib grafts. Vascular bundles implanted into rib grafts remained patent and increased the rate of revascularization. The stripping or preservation of periosteum had no observable effects on the rate or pattern of conventional rib graft revascularization. The circulation in rib grafts was accurately reflected in technetium 99 bone scans, as was the patency of the anastomoses of microvascularized ...
1984-11-01
Benzyl carbamyl analogue of lignocaine: vasodepressor mechanism of action.
1. The benzyl carbamyl analogue of lignocaine [2-(diethylaminoacetamido)-3-carbamyl-4-methyl-5-benzylpyrrole] at an intravenous dose of 4 mg/kg caused a blood pressure decrease of 54 mmHg. 2. A greater hypotensive effect was observed in hypertensive compared to normotensive animals. Anaesthesia magnified the vasodepressor effect in both groups. 3. The analogue did not possess centrally-mediated effects on blood pressure but exerted its hypotensive effect via a peripheral mechanism. 4. The analogue produced a relaxant effect on intestinal and vascular smooth muscle while exerting minimal effects on muscarinic, sympathetic, or ganglionic nicotinic receptors. 5. The analogue exhibited less cardiac depressant action on left ventricular rate (dp/dt) and force of contraction than lignocaine. 6. Lethal effects for the analogue were first observed at 16 mg/kg following intravenous administration and at 500 mg/kg following ...
Analysis of dose rate build-up in Tarapur Atomic Power Station unit-4
International Nuclear Information System (INIS)
Tarapur Atomic Power Station Unit-4 was made critical on 6th March 2005. Since radiation field builds up with the power level due to formation of fission products and activation products in different systems. Radiation dose rates were recorded from different areas using Area Radiation Monitors (ARMs) installed at different areas. These monitors are connected to Radiation Data Acquisition System (RADAS). The trend of radiation field build-up was also analyzed by making survey of different plant areas at various power levels and comparison was made with RADAS readings. The results obtained were compared with 220 MWe dose rates. This study discusses about the dose rates observed at accessible area, shut down accessible area and hotspots observed during the early stage of operation of the reactor. The attempt was also made to find the contributing factors of the high dose rates. It was found that the finding of the study was ...
2005-11-23
Absorption Features in Spectra of Magnetized Neutron Stars
The X-ray spectra of some magnetized isolated neutron stars (NSs) show absorption features with equivalent widths (EWs) of 50 - 200 eV, whose nature is not yet well known. To explain the prominent absorption features in the soft X-ray spectra of the highly magnetized (B ~ 10^{14} G) X-ray dim isolated NSs (XDINSs), we theoretically investigate different NS local surface models, including naked condensed iron surfaces and partially ionized hydrogen model atmospheres, with semi-infinite and thin atmospheres above the condensed surface. We also developed a code for computing light curves and integral emergent spectra of magnetized neutron stars with various temperature and magnetic field distributions over the NS surface. We compare the general properties of the computed and observed light curves and integral spectra for XDINS RBS\\,1223 and conclude that the observations can be explained by a thin hydrogen atmosphere above ...
2010-01-01
A Distinctive Disk-Jet Coupling in the Seyfert-1 AGN NGC 4051
We report on the results of a simultaneous monitoring campaign employing eight Chandra X-ray (0.5-10 keV) and six VLA/EVLA (8.4 GHz) radio observations of NGC 4051 over seven months. Evidence for compact jets is observed in the 8.4 GHz radio band; This builds on mounting evidence that jet production may be prevalent even in radio-quiet Seyferts. Assuming comparatively negligible local diffuse emission in the nucleus, the results also demonstrate an inverse correlation of L_radio proportional to L_X-ray ^(-0.72+/-0.04) . Current research linking the mass of supermassive black holes and stellar-mass black holes in the "low/hard" state to X-ray luminosities and radio luminosities suggest a "fundamental plane of accretion onto black holes" that has a positive correlation of L_radio proportional to L_X-ray^(0.67+/-0.12) . Our simultaneous results differ from this relation by more than 11 sigma, indicating that a separate mode of ...
2010-01-01
$\\gamma$-ray bursts from internal shocks in a relativistic wind temporal and spectral properties
We construct models for gamma-ray bursts where the emission comes from internal shocks in a relativistic wind with a highly non uniform distribution of the Lorentz factor. We follow the evolution of the wind using a very simplified approach where a large number of layers interact by direct collisions but where all pressure waves have been suppressed. We suppose that the magnetic field and the electron Lorentz factor reach large equipartition values in the shocks. Synchrotron photons emitted by the relativistic electrons have a typical energy in the gamma-ray range in the observer frame. Synthetic bursts are constructed as the sum of the contributions from all the internal elementary shocks and their temporal and spectral properties are compared to the observations. We reproduce the diversity of burst profiles, the ``FRED'' shape of individual pulses and the short time scale variability. Synthetic bursts also satisfy the ...
1998-01-01
On the Role of Convection and Turbulence for Tropospheric Ozone and its Precursors
International Nuclear Information System (INIS)
The aim of the work in this thesis is to investigate the convective and diffusive transport in the TM chemistry transport model, and to investigate some aspects of the consequences for NOx. The large inaccuracy and uncertainty in the description of processes like convection and turbulent diffusion, the strong dependence of the radiative forcing of ozone on its vertical distribution, and the strong dependence of the ozone production on the distribution of NOx, are the main motivation. The availability of the ERA-40 data, where convective data and vertical diffusion coefficients are archived, allows a study of the effect of different convective mass flux sets, and different vertical diffusion coefficients on the model-simulated distribution of tracers. In this thesis the following questions are addressed : (1) How large is the sensitivity of the (model simulated) distribution of ozone and nitrogen oxides on (the) convection (parameterisation)?; (2) What requirements should be fulfilled ...
SUBMILLIMETER ARRAY OBSERVATIONS TOWARD THE MASSIVE STAR-FORMING CORE MM1 OF W75N
International Nuclear Information System (INIS)
The massive star-forming core MM1 of W75N was observed using the Submillimeter Array with #approx#1'' and 2'' spatial resolutions at 217 and 347 GHz, respectively. From the 217 GHz continuum we found that the MM1 core consists of two sources, separated by about 1'': MM1a (#approx#0.6 M_s_u_n) and MM1b (#approx#1.4 M_s_u_n), located near the radio continuum sources VLA 2/VLA 3 and VLA 1, respectively. Within MM1b, two gas clumps were found to be expanding away from VLA 1 at about #+-#3 km s"-"1, as a result of the most recent star formation activity in the region. Observed molecular lines show emission peaks at two positions, MM1a and MM1b: sulfur-bearing species have emission peaks toward MM1a, but methanol and saturated species at MM1b. We identified high-temperature (#approx#200 K) gas toward MM1a and the hot core in MM1b. This segregation may result from the evolution of the massive star-forming core. In the very early phase of star ...
2010-11-10
Energy Technology Data Exchange (ETDEWEB)
The goal of the present work has been to clarify the influence of sulphate ions on the oxide films formed on stainless steel and Ni-based alloys in simulated crack chemistry conditions using different ex situ analytical techniques. The main observations of this work can be summarised as follows: The thickness of the films formed in simulated oxygen-free crack chemistry conditions during an exposure of circa 4 days varies roughly in the range 200..500 nm, which corresponds to observations reported in the literature [2]. The presence of 10000 ppb sulphate ions in simulated crack tip conditions seems to lead to a considerably lower thickness of the oxide films when compared to sulphate-free conditions. The presence of 10000 ppb sulphate ions leads also to considerable changes in the morphology of the oxide crystals on the material samples. In the absence of sulphate the outer oxide layer contains elongated round-edged ...
2002-07-01
Energy Technology Data Exchange (ETDEWEB)
Since 1984 the Environmental Protection Agency (LfU) of the State of Baden-Wuerttemberg has been investigating the heavy metal burden of earthworms from representative long-term forest observation plots. These investigations are aimed at elucidating and assessing adverse effects of pollutants on the soil biocenosis. Methods: At first only lead and cadmium were measured in the worms; in repetitive measurements over the years further metals or metalloid elements such as aluminum, arsenic, chromium, cobalt, copper, manganese, mercury, nickel, thallium, vanadium, and zinc were added to the agenda. Results and conclusion: The frequency distribution of the metals in the earthworms was characterized statistically. For the first time state-wide background values, normal values and threshold values were established for all the elements measured. A comparable study with a similar range of parameters is known neither nationally nor internationally. Time ...
2006-08-15
Energy Technology Data Exchange (ETDEWEB)
The dry deposition of pollutants can be calculated from the concentration of pollutants in the atmosphere and deposition velocity. To calculate deposition velocity, turbulence parameters such as friction velocity and Monin-Obukhov length are used. However, due to the difficulties in observation of turbulence parameters, usually mean values of wind speed and temperature observed using conventional meteorological instruments are used to estimate the dry deposition. The dry deposition velocity is the function of aerodynamic resistance (R{sub a}), sublayer resistance (R{sub b}), surface resistance (R{sub c}). R{sub a} and R{sub b} are calculated from turbulence parameters and R{sub c} is related to surface characteristics. The purpose of the present study is to compare the dry deposition obtained using the data sets of mean values and turbulence parameters measured by sonic anemometer-thermometer. The field ...
1996-12-31
International Nuclear Information System (INIS)
This study was carried out to evaluate the effects of irradiation (gamma irradiation at dose levels of 0.0, 2.5, 5.0, 10.0 or 20.0 kGy, He-Ne and their combination) on nutritive characteristics of Vicia faba L. seeds (Giza 843). Analyses included levels of anti-nutrients (total phenolic compounds, tannins, phytic acid, trypsin inhibitor and vicine), chemical composition (sugars, crude proteins, fat, dry matter and ash) and fatty acids profile. All treatments caused significant (P<0.05) decreases in the antinutrational factors under investigation. The reduction in the content of tannins and phenolic compounds were more pronounced with He-Ne alone or He-Ne in combination with gamma irradiation. At dose levels 10.0 and 20.0 kGy without or with combination of He-Ne were more efficiency in the reduction of phytic acid content by 24.3, 32.8, 34.5 and 45.5 %, respectively. Also, for trypsin inhibitor activity, the maximum inhibition was observed with the treatment of ...
{sup 35}Cl + {sup 12}C asymmetrical fission excitation functions
Energy Technology Data Exchange (ETDEWEB)
The fully energy-damped yields from the {sup 35}Cl + {sup 12}C reaction have been systematically investigated using particle-particle coincidence techniques at a {sup 35}Cl bombarding energy of {approx} 8 MeV/nucleon. The fragment-fragment correlation data show that the majority of events arises from a binary-decay process with rather large numbers of secondary light-charged particles emitted from the two excited exit fragments. No evidence is observed for ternary breakup events. The binary-process results of the present measurement, along with those of earlier, inclusive experimental data obtained at several lower bombarding energies are compared with predictions of two different kinds of statistical model calculations. The methods give comparable predictions and are both in good agreement with the experimental results thus confirming the fusion-fission origin of the fully-damped yields. (author). 39 refs. Submitted to ...
1996-04-01
Xeroradiography and computed radiography comparative study on diagnosis for breast cancer
Energy Technology Data Exchange (ETDEWEB)
Xeroradiography (XR) was retrospectively compared with a newly developed computed radiography (FCR) for diagnostic availability for breast cancer. FCR provides with the image processed by a computer. Subjects were 65 breast cancer patients for XR and 51 for FCR. Both methods were performed preoperatively. No significant difference was observed in distribution of age between the two groups but the average tumor size in XR group was larger than that in FCR group. Tumor shadow appeared in 44 of 65 xeromammograms (67.7%) and in 34 of 51 computed radiograms (66.7%). Microcalcification was detected in 27 of 65 xeromammograms (41.5%) and in 21 of 51 computed radiograms (41.2%). Consequently, diagnosis of breast cancer could be achieved in 47 of 65 patients (72.3%, established: 39, suspective: 8) through XR and in 41 of 51 (80.4%, established: 33, suspected: 8) through FCR. Thus FCR is thought to be more useful for breast cancer because it not only ...
1990-04-01
Xeroradiography and computed radiography comparative study on diagnosis for breast cancer
International Nuclear Information System (INIS)
Xeroradiography (XR) was retrospectively compared with a newly developed computed radiography (FCR) for diagnostic availability for breast cancer. FCR provides with the image processed by a computer. Subjects were 65 breast cancer patients for XR and 51 for FCR. Both methods were performed preoperatively. No significant difference was observed in distribution of age between the two groups but the average tumor size in XR group was larger than that in FCR group. Tumor shadow appeared in 44 of 65 xeromammograms (67.7%) and in 34 of 51 computed radiograms (66.7%). Microcalcification was detected in 27 of 65 xeromammograms (41.5%) and in 21 of 51 computed radiograms (41.2%). Consequently, diagnosis of breast cancer could be achieved in 47 of 65 patients (72.3%, established: 39, suspective: 8) through XR and in 41 of 51 (80.4%, established: 33, suspected: 8) through FCR. Thus FCR is thought to be more useful for breast cancer because it not only ...
1990-01-01
Energy Technology Data Exchange (ETDEWEB)
Today, as a result of increase in oil prices, limited fossil fuel resources, environmental consideration and global warming, the methyl ester fuels have been focused on alternative fuels. Methyl ester fuels can be used more efficiently in low heat rejection engines (LHR), in which the temperature of combustion chamber is increased by creating a thermal barrier. In this study, the piston, cylinder head, exhaust and inlet valves of a diesel engine were coated with the ceramic material Al{sub 2}O{sub 3}-TiO{sub 2} by the plasma spray method. Thus, a thermal barrier was provided for the parts of the combustion chamber with these coatings. The effects of corn oil methyl ester that produced by the transesterification method, and No. D2 fuels' performance and exhaust emissions' rate were studied by using equal in every respect coated and uncoated engines. Tests were performed on the uncoated engine, and then repeated on the coated engine and the results were ...
2010-10-15
The effect of meal size on gastric evacuation in whiting
DEFF Research Database (Denmark)
Gastric evacuation experiments were performed on whiting Merlangius merlangus fed discrete meals of different sizes. Herring Clupea harengus, sandeel Ammodytes tobianus, common goby Pomatoschistus microps, and brown shrimp Crangon crangon were tested as prey. A simple power model to describe gastric evacuation was evaluated and compared with a power model expanded as a function of meal size. The model parameters were estimated by means of nonlinear least squares. When all meal sizes were included the estimates of the power (curvature) parameter in the expanded model were within the range 0.36-0.77 for the different prey. The power estimates in the simple model were generally close to 0.5. The exception was crustacean prey, which gave a higher value. In the simple model the power estimate represents a compromise between the curvatures of the curves fitted to the observations for each meal size and the relationship between meal size and overall ...
1998-01-01
International Nuclear Information System (INIS)
Pulmonary clearance of an aerosol of "9"9Tc"m DTPA was measured in 21 non-smoking AIDS and pneumocystosis patients. The results were compared with those of pulmonary scintiscanning with gallium. All the patients exhibited increased clearance, evidence of a considerable alteration in alveolar permeability. This increase was also observed in patients with normal chest X-rays and normal blood gases. The average clearance in these patients was 6 #+-# 2% min"-"1 as compared with a normal 1.1 #+-# 0.3% min"-"1. Conversely, only four out of eight patients with normal chest X-rays had abnormal gallium scans. Clearance returned to normal after recovery. Measurement of DTPA clearance appears to be a very sensitive indicator for the detection and follow-up of pneumocystosis. However, it is not very specific since it can be increased by tobacco poisoning, drug abuse and the presence of lymphocytic alveolitis. An examination with normal ...
1988-08-15
Reduction in radiation-induced brain injury by use of pentobarbital or lidocaine protection
Energy Technology Data Exchange (ETDEWEB)
To determine if barbiturates would protect brain at high doses of radiation, survival rates in rats that received whole-brain x-irradiation during pentobarbital- or lidocaine-induced anesthesia were compared with those of control animals that received no medication and of animals anesthetized with ketamine. The animals were shielded so that respiratory and digestive tissues would not be damaged by the radiation. Survival rates in rats that received whole-brain irradiation as a single 7500-rad dose under pentobarbital- or lidocaine-induced anesthesia was increased from between from 0% and 20% to between 45% and 69% over the 40 days of observation compared with the other two groups (p less than 0.007). Ketamine anesthesia provided no protection. There were no notable differential effects upon non-neural tissues, suggesting that pentobarbital afforded protection through modulation of ambient neural activity during radiation ...
1990-05-01
Pulse Shapes From Rapidly-Rotating Neutron Stars: Equatorial Photon Orbits
We demonstrate that fitted values of stellar radius obtained by fitting theoretical light curves to observations of millisecond period X-ray pulsars can significantly depend on the method used to calculate the light curves. The worst-case errors in the fitted radius are evaluated by restricting ourselves to the case of light emitted and received in the equatorial plane of a rapidly-rotating neutron star. First, using an approximate flux which is adapted to the one-dimensional nature of such an emission region, we show how pulse shapes can be constructed using an exact spacetime metric and fully accounting for time-delay effects. We compare this to a method which approximates the exterior spacetime of the star by the Schwarzschild metric, inserts special relativistic effects by hand, and neglects time-delay effects. By comparing these methods, we show that there are significant differences in these methods for some ...
2005-01-01
Energy Technology Data Exchange (ETDEWEB)
Glacier fluctuations exclusively due to internal variations in the climate system are simulated using downscaled integrations of the ECHAM4/OPYC coupled general circulation model (GCM). A process-based modeling approach using a mass balance model of intermediate complexity and a dynamic ice flow model considering simple shearing flow and sliding are applied. Multi-millennia records of glacier length fluctuations for Nigardsbreen (Norway) and Rhonegletscher (Switzerland) are simulated using auto-regressive processes determined by statistically downscaled GCM experiments. Return periods and probabilities of specific glacier length changes using GCM integrations excluding external forcings such as solar irradiation changes, volcanic or anthropogenic effects are analyzed and compared to historical glacier length records. Preindustrial fluctuations of the glaciers as far as observed or reconstructed, including their advance during the ...
2001-08-01
Kinetics of the stress induced phase transition in quartz by real-time neutron scattering
International Nuclear Information System (INIS)
Complete text of publication follows. The stability regime of the incommensurate phase of quartz is influenced by uniaxial stress. Hence, the phase transition can be induced under isothermal conditions by the application of external mechanical forces. Using real-time neutron scattering the time evolution of structural changes is investigated id detail during stress variations. The time dependent behaviour of the satellite reflection is compared with that one of the fundamental Bragg reflection which - via primary extinction - gives information about the perfection of the crystal. On increasing stress the perfection of the lattice is destroyed immediately while the modulated structure is built up with a delay of about 1 s. Decreasing the stress leads to a reverse behaviour. Moreover, there is evidence that under periodical load residual non-relaxed strain fields survive leading to a different temperature dependence as compared to static ...
1999-09-01
Improvement of the mechanical properties of austenitic stainless steel after plasma nitriding
Energy Technology Data Exchange (ETDEWEB)
In this paper, we report on a series of experiments designed to study the influence of plasma nitriding on the mechanical properties of austenitic stainless steel. Plasma nitriding experiments were conducted on AISI 304L steel in a temperature range of 375-475 C using pulsed-DC plasma with different N{sub 2}-H{sub 2} gas mixtures and treatment times. Firstly the formation and the microstructure of the modified layer will be highlighted followed by the results of hardness measurement, adhesion testing, wear resistance and fatigue life tests. The modified surface was analyzed directly after plasma nitriding as well as using a depth profiling method. The microhardness after plasma nitriding is increased up to 19 GPa, that is a factor of five higher compared to the untreated material (3.3 GPa). The adhesion is examined by Rockwell indentation and scratch test. No delamination of the treated layer could be observed. The wear rate after plasma ...
2000-11-01
Extreme Ultraviolet Emission from Abell 4059
We present the results of a search for Extreme Ultraviolet emission in A4059, a cluster with an X-ray emitting cluster gas. Our analysis of Extreme Ultraviolet Explorer (EUVE) Deep Survey observations of this cluster shows that it is associated with diffuse EUV emission. Outside the central 2 arcmin radius the entire EUV emission detected is explained by the low energy tail of the X-ray emitting gas. Within the central 2 arcmin region of the cluster we find a deficit of EUV emission compared to that expected from the X-ray gas. This flux deficit is discussed in the context of the cluster's cooling flow. The results derived for A4059 are compared to EUVE results obtained for other clusters such as Coma, Virgo, A1795, and A2199. As part of the study we have carried out a detailed investigation of the stability of the EUVE Deep Survey detector background. Based on long integrations of blank sky over 27 months we disprove ...
2000-01-01
Energy Technology Data Exchange (ETDEWEB)
Swift heavy ion-solid interaction leads in volume to track creation and on the surface to the ejection of particles into the vacuum. To learn more about initial mechanisms of track formation, we are focused on the sputtering of uranium dioxide by fast heavy ions. This present study is exclusively devoted to the influence of the electronic stopping power on the emission of neutral particles and especially on their angular distribution. These measurements are completed by those of the ions emitted from UO{sub 2} targets bombarded with swift heavy ions. The whole experimental results give access to: i) the nature of the sputtered particles; ii) the charge state of the emitted particles; iii) the direction of ejection of the sputtered particles ; iv) the sputtering yields deduced from the angular distributions. These results are compared to the prediction of the sputtering models proposed in the literature and it seems that the supersonic gas flow model is well suited ...
2001-03-01
International Nuclear Information System (INIS)
To assess the diagnostic capability Fuji computed radiography (FCR) using a dual side reading system was compared to the conventional radiography using a film-screen system. Twenty-eight patients with lung cancer were examined with a new FCR system (FCR 5501D) and a conventional screen-film system concurrently. FCR utilizes a reading system that detects emissions from dual sides of imaging plate. Chest X-rays were obtained with same exposure factors in both systems. Image qualities of both systems were compared by two radiologists using a five-level score. There were no lesion that FCR images were inferior to film-screen images. The frequency of score +1 or +2 that FCR images were superior to film-screen images was 31% in large nodular shadows, 40% in accompanying shadows with a nodule, 67% of small nodular shadows, and 43% of the lymph node swelling in the hilum of the lung or mediastinum. In large nodular shadows which were the most frequent ...
2003-02-01
Energy Technology Data Exchange (ETDEWEB)
The corrosion resistance of steel-reinforced mortar specimens made from alinite cement was investigated using ordinary Portland cement (OPC) specimens as reference. The specimens were prepared and exposed in three different environments: continuous exposure in tap water, interrupted exposure in tap water, and interrupted exposure in 3.5% NaCl solution. The steel weight loss and the half cell potential were measured vs. exposure time, up to the age of 12 months. Pore solution extraction and analysis and porosity determination were also performed. In continuous exposure in tap water, alinite cement provided adequate protection against corrosion. In interrupted exposure in tap water, a higher corrosion was observed for alinite cement compared to OPC. In the case of interrupted exposure in 3.5% NaCl solution, the simultaneous action of free chlorides and oxygen resulted in the depassivation of steel reinforcing bars in alinite and Portland cement ...
1998-07-01
The vertical profiles of disc galaxies are built by the material trapped around stable periodic orbits, which form their "skeletons". According to this, the knowledge of the stability of the main families of periodic orbits in appropriate 3D models, can predict possible morphologies for edge-on disc galaxies. In a pilot survey we compare the orbital structures which lead to the appearance of "peanuts" and "X"-like features with the edge-on profiles of three disc galaxies (IC 2531, NGC 4013 and UGC 2048). The subtraction from the images of a model representing the axisymmetric component of the galaxies reveals the contribution of the non-axisymmetric terms. We find a direct correspondence between the orbital profiles of 3D bars in models and the observed main morphological features of the residuals. We also apply a simple unsharp masking technique in order to study the sharpest features of the images. Our basic conclusion is that the morphology ...
2006-01-01
Examination of measurement invariance provides a powerful method to evaluate the hypothesis that the same set of psychological constructs underlies a set of test scores in different populations. If measurement invariance is observed, then the same psychological meaning can be ascribed to scores in both populations. In this study, the measurement model including core and supplementary subtests of the Wechsler Adult Intelligence Scale-Fourth edition (WAIS-IV) were compared across the U.S. and Canadian standardization samples. Populations were compared on the 15 subtest version of the test in people aged 70 and younger and on the 12 subtest version in people aged 70 or older. Results indicated that a slightly modified version of the four-factor model reported in the WAIS-IV technical manual provided the best fit in both populations and in both age groups. The null hypothesis of measurement invariance across populations was not ...
2011-06-01
A new application of MRT of the lung using ultra-shot turbo spin echo sequences (UTSE)
International Nuclear Information System (INIS)
T_2 weighted ultra-short turbo spin echo sequences were used in five individuals with variations in echo times, delayed triggering and echo intervals. To reduce movement artifacts all examinations were carried out with ECG and respiratory triggering. The sequences giving optimal image quality were then employed in 19 patients having various pulmonary abnormalities. Image resolutions, artifacts, image contrasts and diagnostic value were then judged by two observers and compared with CT. In the first study, a diastole-triggered UTSE sequence with the shortest echo proved optimal (T_E=90 ms, T_R=2-4 s, echo=9 ms, turbo factor=19). In the patient series studied, MRT was inferior to CT with regard to resolution and number of artifacts, but better in respect of contrast and diagnostic value. Using UTSE of the lung, MRT can produce images of good quality. Compared with CT, contrast is better with MRT, offering diagnostic ...
British Library Electronic Table of Contents (United Kingdom)
Recent studies have shown Y chromosome microdeletions associated with male infertility. The factors responsible for Y chromosome microdeletions in spermatozoa remain unresolved. However, the environmental pollutants are known to damage DNA in differentiating and maturing germ cells in the male reproductive tract. Therefore, the aim of this study was to investigate the effects of seminal hexachlorocyclohexane (HCH) and its isomers, an environmental pollutant, in 50 fertile and 50 infertile males in relation to semen quality and the incidence of Y chromosome microdeletion in azoospermic factor (AZF) region. As compared to control, an increased HCH level and significantly decreased semen quality were observed in the infertile males. A positive significant association was found between sperm c...
2010-01-01
British Library Electronic Table of Contents (United Kingdom)
Objectives This paper examines the determinants of the insureds decision to use their health insurance card when seeking outpatient and inpatient health care in Vietnam. Methods Uses Vietnams latest Household Living Standard Survey data and random-intercept logistic regression to assess the influence of the observed individual, household and commune/ward factors on the insureds decision to access health insurance benefits while controlling for the unobserved commune/ward-specific factors. Results Compared to the compulsory enrollees, the voluntary enrollees and the beneficiaries of the Health Care Fund for the Poor are less likely to use their card when seeking inpatient care. An individuals likelihood of accessing insurance benefits varies inversely with income and the level of education,...
2009-01-01
Vibration experiment for a three-loop PWR reactor building
International Nuclear Information System (INIS)
Forced vibration experiment has been conducted for the reactor building of Sendai Unit 1 nuclear power plant. The beam vibrational behaviors of the outer shielding building and the internal concrete structure have been observed by using a 50 tf vibration for low frequency region, and a 10 tf vibration for high frequency region, respectively. The outline of the experimental methods, the data handling system and the major results of experiment are described. The experimental results were simulated by an analytical model. The proper vibrational frequency and the vibration modes obtained by the analysis were compared with those obtained by the experiment. By these comparison, the adequacy of the analytical method employed for the design was confirmed. (Aoki, K.).
1983-01-01
British Library Electronic Table of Contents (United Kingdom)
In order to provide pigs a comfortable sleeping area in hot weather, a floor cooling system was designed and applied to production buildings. Experiments were conducted to compare the floor temperatures and to observe the lying behaviour of pigs in the sleeping area of the buildings with and without floor cooling system. The results showed that, without the floor cooling system, the floor temperature was nearly the same as the air temperature in the open pig house. With the floor cooling system, the floor temperature of the sleeping area was controlled at 22-26degreeC, even though the air temperature was as high as 34degreeC, which improved the comfort of the pigs in the sleeping area. The pig lying behaviour was greatly affected by the floor temperature. More than 85% of the pigs were lyi...
2006-01-01
Energy Technology Data Exchange (ETDEWEB)
The detectors used in the TS93 balloon flight produced a large volume of information for each cosmic ray trigger. Some of the data was visual in nature, other portions contained energy deposition and timing information. The data sets are amenable to conventional analysis techniques but there is no assurance that conventional techniques make full use of subtle correlations and relations amongst the detector responses. With the advent of neural network technologies, particularly adept at classification of complex phenomena, it would seem appropriate to explore the utility of neural network techniques to classify particles observed with the instruments. In this paper neural network based methodology for signal/background discrimination in a cosmic ray space experiment is discussed. Results are presented for electron and positron classification in the TS93 flight data set and will be compared to conventional analyses.
1995-09-01
Translocation of labelled sucrose: A student exercise
Energy Technology Data Exchange (ETDEWEB)
Photosynthetic carbohydrates from the leaves are exported through the phloem to growing tips, roots, flowers and fruits. If sucrose labelled with {sup 14}C is applied to the leaves of bean plants, the pathway for sugar movement may be readily observed by autoradiography. Students apply the labelled sucrose during class time and return the next day to press their plants. During the next class, the pressed and dried plants are placed against X-ray film and left in the dark for four weeks. the film is then developed, examined for presence of label and compared to the pressed plants. Source to sink movement is clearly illustrated and information about the mechanism of phloem transport and loading is gained through experimental treatments, which include blocking the phloem pathway and inhibiting energy production.
1990-05-01
Three-dimensional modeling of the flow and the interface surface in a continuous casting mold model
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.
1999-12-01
Based on a collisional-radiative model, an atomic-kinetic calculation of the gains on the 41.8-nm transitions of Pd-like xenon was performed for the plasma produced due to the interaction of a femtosecond laser pulse with gaseous xenon. The gains g(z,{tau}) averaged over the spatial and temporal coordinates were compared with the known gains which had been measured experimentally in Xe{sup 8+}. The amplification was shown to occur under the conditions of ionisation of the working ions, and the time of output radiation saturation depends on the time of Xe{sup 8+} transformation to higher-ionised ions. Our theoretical investigation enables determining the optimal pump parameters, at which the product of the gain g by the active medium length L is about 20, which exceeds the experimental gL value. (active media)
2004-11-30
International Nuclear Information System (INIS)
Based on a collisional-radiative model, an atomic-kinetic calculation of the gains on the 41.8-nm transitions of Pd-like xenon was performed for the plasma produced due to the interaction of a femtosecond laser pulse with gaseous xenon. The gains g(z,?) averaged over the spatial and temporal coordinates were compared with the known gains which had been measured experimentally in Xe8+. The amplification was shown to occur under the conditions of ionisation of the working ions, and the time of output radiation saturation depends on the time of Xe8+ transformation to higher-ionised ions. Our theoretical investigation enables determining the optimal pump parameters, at which the product of the gain g by the active medium length L is about 20, which exceeds the experimental gL value. (active media)
2004-11-30
The type III secretion system is involved in Escherichia coli K1 interactions with Acanthamoeba
British Library Electronic Table of Contents (United Kingdom)
The type III secretion system among Gram-negative bacteria is known to deliver effectors into host cell to interfere with host cellular processes. The type III secretion system in Yersina, Pseudomonas and Enterohemorrhagic Escherichia coli have been well documented to be involved in the bacterial pathogenicity. The existence of type III secretion system has been demonstrated in neuropathogenic E. coli K1 strains. Here, it is observed that the deletion mutant of type III secretion system in E. coli strain EC10 exhibited defects in the invasion and intracellular survival in Acanthamoeba castellanii (a keratitis isolate) compared to its parent strain. Next, it was determined whether type III secretion system plays a role in E. coli K1 survival inside Acanthamoeba during the encystment process...
2011-01-01
The geometry emerging from the symmetries of a quantum system
We investigate the relation between the symmetries of a quantum system and its topological quantum numbers, in a general C*-algebraic framework. We prove that, under suitable assumptions on the symmetry algebra, there exists a generalization of the Bloch-Floquet transform which induces a direct-integral decomposition of the algebra of observables. Such generalized transform selects uniquely the set of "continuous sections" in the direct integral, thus yielding a Hilbert bundle. The emerging geometric structure provides some topological invariants of the quantum system. Two running examples provide an Ariadne's thread through the paper. For the sake of completeness, we review two related theorems by von Neumann and Maurin and compare them with our result.
2009-01-01
Many alternative therapies are used as first aid treatment for burns, despite limited evidence supporting their use. In this study, Aloe vera, saliva and a tea tree oil impregnated dressing (Burnaid) were applied as first aid to a porcine deep dermal contact burn, compared to a control of nothing. After burn creation, the treatments were applied for 20 min and the wounds observed at weekly dressing changes for 6 weeks. Results showed that the alternative treatments did significantly decrease subdermal temperature within the skin during the treatment period. However, they did not decrease the microflora or improve re-epithelialisation, scar strength, scar depth or cosmetic appearance of the scar and cannot be recommended for the first aid treatment of partial thickness burns. PMID:18603378
2008-07-07
The effect of hydrogenation/dehydrogenation cycles on palladium physical properties
International Nuclear Information System (INIS)
A series of hydrogenation/dehydrogenation cycles have been performed on palladium wire samples, stressed by a constant mechanical tension, in order to investigate the changes in electrical and mechanical properties. A large increase of palladium electrical resistivity has been reported due to the combined effects of the production of defects linked to hydrogen insertion into the host lattice and the stress applied to the sample. An increase of the palladium sample strain due to hydrogenation/dehydrogenation cycles in ????? phase transitions is observed compared to the sample subjected to mechanical tension only. The loss of initial metallurgical properties of the sample occurs already after the first hydrogen cycle, i.e. a displacement from the initial metallic behavior (increase of the resistivity and decrease of thermal coefficient of resistivity) to a worse one occurs already after the first hydrogen cycle. A linear correlation between ...
2009-08-24
The effect of excimer laser pretreatment on diffusion and activation of boron implanted in silicon
International Nuclear Information System (INIS)
We have investigated the effect of excimer laser annealing (ELA) on transient enhanced diffusion (TED) and activation of boron implanted in Si during subsequent rapid thermal annealing (RTA). It is observed that ELA with partial melting of the implanted region causes reduction of TED in the region that remains solid during ELA, where the diffusion length of boron is reduced by a factor of #approx#4 as compared to the as-implanted sample. This is attributed to several mechanisms such as liquid-state annealing of a fraction of the implantation induced defects, introduction of excess vacancies during ELA, and solid-state annealing of the defects beyond the maximum melting depth by the heat wave propagating into the Si wafer. The ELA pretreatment provides a substantially improved electrical activation of boron during subsequent RTA.
2005-11-07
Television interference and acoustic emissions associated with the operation of the Darrieus VAWT
Field surveys were conducted to assess the community annoyance potential from electromagnetic interference to television reception (TVI) and acoustic emissions associated with the operation of a Darrieus-type, vertical axis wind turbine (VAWT). The type and extent of interference to nearby television reception was evaluated using a 17 meter VAWT. A series of measurements of observed interference levels were made at a number of sites in the turbine vicinity employing the locally available VHF and UHF television signals as sources. A simple theoretical model was developed for analyzing the TVI produced by the Darrieus turbine. Using this model in conjunction with the field measurements, it was found the Darrieus/VAWT produces the same amount of interference on the lower VHF channels as a horizontal axis turbine with a comparably sized blade scattering area, but less on all other channels.
1981-01-01
Three adolescents (ages 14-17) with emotional and behavioral disorders displayed chronic disruptive behavior in their self-contained classrooms at a self-contained alternative school. A descriptive functional behavioral assessment was conducted for each student. Data from file review, structured interviews, and direct observations were used to identify the functions of their disruptive behaviors. Then, function-based interventions were systematically constructed for each student and implemented for an extended period (nearly 6 weeks) within the most problematic situation in their classrooms. The interventions improved each student's behavior and the effects maintained during follow-up and generalized to instruction in a nonintervention classroom. Social validity data comparing the interventions to baseline practices revealed the function-based intervention had moderately higher social validity among teachers and substantially higher social ...
2011-02-01
British Library Electronic Table of Contents (United Kingdom)
A stable BSA blocking poly(dimethylsiloxane) (PDMS) microchannel was prepared based on in situ synthesized PDMS-gold nanoparticles composite films. The modified microchip could successfully suppress protein adsorption. The assembly was followed by contact angle, charge-coupled device (CCD) imaging, electroosmotic flow (EOF) measurements and electrophoretic separation methods. Contact angle measurements revealed the coated surface was hydrophilic, water contact angle for coated chips was 45.2^o compared to a water contact angle for native PDMS chips of 88.5^o. The coated microchips exhibited reproducible and stable EOF behavior. With FITC-labeled myoglobin incubation in the coated channel, no fluorescence was observed with CCD image, and the protein exhibited good electrophoretic effect in ...
2010-01-01
Statistical analyses of coads wind data in coastal regions of the United States
Energy Technology Data Exchange (ETDEWEB)
In the study, wind data from the Comprehensive Ocean-Atmosphere Data Set (COADS) are used to determine atmospheric circulation changes which are empirically associated with the air temperature changes. Some understanding of the natural processes which produce climate change is anticipated from the study of these associations. Systematic changes of wind in US coastal regions with periods of climate warming and cooling suggest circulation changes, in addition to carbon dioxide-controlled radiation effects, could produce the climate changes indicated by air temperature. A statistical procedure for analyses of COADS was used to determine decade-period vector wind-field differences from the COADS record period. The statistical procedure for these analyses is explained and the wind differences are compared to summaries of mid-Atlantic coast island-station observations.
1992-08-01
Some properties of composite panels made from wood flour and recycled polyethylene.
This study investigated the effect of board type (unmodified vs. MAPE modified) on the surface quality and thickness swelling-water absorption properties of recycled high density polyethylene (HDPE) based wood plastic composites. Additionally, two commercially available coatings (cellulosic coating and polyurethane lacquer coating) were also applied to composite surfaces and their adhesion strength, abrasion and scratch resistance, and gloss values were determined. This study showed that modification of the composites with MAPE coupling agent increased the surface smoothness and reduced the water absorption and thickness swelling of the panels. Abrasion resistance of the composites was also improved through MAPE modification. Regardless of board type, higher scratch resistance and gloss values were observed for polyurethane lacquer coated samples compared to those of cellulosic varnish coated ones. Improvement of adhesion strength was also seen ...
2008-12-10
Some geotechnical aspects of the Hyogo-ken Nanbu (Kobe) earthquake of January 17, 1995
Energy Technology Data Exchange (ETDEWEB)
A geological and geotechnical framework was provided in order to facilitate understanding of the damage to structures resulting from soil conditions during the earthquake of January 17, 1995 at Hyogo-ken Nanbu (Kobe), Japan. Special attention was paid to the large scale failures of the quay walls in the port of Kobe, resulting from liquefaction. The performance of structures in improved and unimproved ground were compared. It was observed that locations with some previous site improvements through densification behaved satisfactorily, despite unanticipated high levels of ground motion. Soil-structure interaction problems, such as pile foundations, bridge piers, lifelines, and an underground subway station were also described. Reference was made to the significance of these failures for the seismic design in the Fraser Delta in British Columbia in view of the area`s proneness to liquefaction during a major earthquake. 31 refs., 5 tabs., 45 figs.
1996-06-01
International Nuclear Information System (INIS)
Bisaminoethanethiol (BAT) ligands with various gem-dimethyl and amide groups were prepared, and the corresponding neutral Tc-99m complexes were prepared and evaluated for their relative stabilities by ligand-exchange reactions. It was demonstrated that technetium complexes containing gem-dimethyl substituents have higher lipophilicities, whereas those with an amide group possess greater stability, which enhances ligand-exchange reaction. The most interesting observation was that the brain uptake in rats is not determined only by lipophilicity. Apparently, Tc-99m complexes with an amide functional group display lower brain uptakes in rats compared to those without an amide group. The brain uptake was strongly influenced by substituents on the BAT ligand. These factors are critically important and should be taken into consideration when designing Tc-99m-labeled agents for CNS receptor imaging.
1998-02-01
Search for tachyons associated with EAS at energies E>=3x10"1"6eV
International Nuclear Information System (INIS)
This paper describes an experiment which has been performed with a somewhat different philosophy in its approach as compared to previous work. (a) The trigger threshold energy was increased by more than a factor of ten on previous experiments reducing the dilution effect of many lower energy showers known not to produce tachyons. 1673 shower were recorded. (b) The exposure time was made longer than previous experiments in order to obtain a reasonably large statistical sample at the higher threshold. Observations were made between February 1979 and June 1980, the total live time being 9768 hours. (c) Records of the detector output amplitude for the 480#mu#s lead time were integrated point by point as is sometimes done in radio astronomy, this gives the integrated energy deposition within the detector.
SPH simulations of accretion flow via Roche lobe overflow and via mass transfer from Be disk
We compare the accretion flow onto the neutron star induced by Roche lobe overflow with that by the overflow from the Be disk, in a zero eccentricity, short period binary with the same mass transfer rate, performing three-dimensional Smoothed Particle Hydrodynamics simulations. We find that a persistent accretion disk is formed around the neutron star in both cases. The circularization radius of the material transferred via Roche lobe overflow is larger than that of the material transfered from the Be disk. Thus, the growth of the accretion disk in the former case becomes significantly slower than in the latter case. In both cases, the mass accretion rate is very small and varies little with orbital phase, which is consistent with the observed X-ray behaviour of Be/X-ray binaries with circular orbits (e.g. XTE J1543-568).
2005-01-01
Energy Technology Data Exchange (ETDEWEB)
In order to realize simultaneous reduction of NO{sub x} and Particulate emissions, effects of combustion chamber geometry were investigated in a high speed direct-injection diesel engine. The reentrant combustion chambers with different throat diameter were compared in terms of engine performance, combustion characteristics and emissions such as NO{sub x}, particulate and THC. The phenomena of combustion process were also observed with endoscopic high speed photography. The results showed that when the throat diameter of a reentrant combustion chamber was reduced to an extent, NO{sub x} and particulate decreased simultaneously due to retarded injection timing and the intensified squish. (author)
1999-10-25
Energy Technology Data Exchange (ETDEWEB)
The impact of the azimuthal wave refraction in the middle atmosphere on the distribution of gravity wave amplitudes, propagation azimuths, and other wave parameters is investigated using a numerical ray-tracing model of gravity wave propagation through a representative zonal mean reference model of geostrophic winds and temperature in the middle atmosphere. Simulations are first performed with only a single type of gravity wave to help explain some important effects which occur during the refraction process. Then, a multiray simulation is performed which traces a crude spectrum of waves from different altitudes through the atmosphere for every month of a climatological year. The simulated wave climatologies are compared with observations. 108 refs.
1992-10-01
Properties and physiological effects of thermal carbon black.
Studies have been carried out to determine the possible physiological effects of contact with carbon black made by the thermal process. Contact was made by ingestion, skin application and/or inhalation. Ingestion and/or skin application do not appear to lead to any changes from the normal. Inhalation exposures do not produce pulmonary function changes (antemortem or postmortem studies) but may lead to moderate to severe "perifocal" emphysema in Rhesus monkeys (not observed in guinea pigs). Inhalation studies also suggest right ventricular septal and to a degree, left ventricular hypertrophy in Rhesus monkeys as an effect. Additional studies are necessary to support these finding and consideration must be given to the variability among exposed subjects as compared to controls. PMID:136503
1976-11-01
Preparation of cost-effective Pt-Co electrodes by pulse electrodeposition for PEMFC electrocatalysts
International Nuclear Information System (INIS)
Graphical abstract: - Abstract: Low loading platinum-cobalt (Pt-Co) cathode catalyst on a Nafion(Na+)-bonded carbon layer is fabricated by using galvanostatic pulse technique to show the advantage of electrodeposition for high utilization of catalyst in proton exchange membrane fuel cell (PEMFC). We observed that Pt-Co catalysts evenly exist on the surface of carbon electrode and its thickness is about 5.8 ?m, which is four times thinner than conventional Pt/C. Improved single cell power performance of Pt-Co cathode catalysts with a ratio of 3.2:1 compared with Pt/C is clearly presented.
2011-03-01
International Nuclear Information System (INIS)
Neutron energy spectra were measured for two OSURR experimental facilities. The method of multiple foil activation was used with the SAND-II neutron spectrum unfolding code to obtain spectral data for the Central Irradiation Facility and Rabbit tube. Limited data was obtained for the thermal column using only gold foils. Calculations were made of the neutron environment in various locations using the MORSE code. A shift towards higher neutron energies was observed comparing results for LEU and HEU cores. A slight loss in total thermal neutron flux was measured for all positions. Calculational results show reasonable agreement with measured data.
1993-07-01
Plasma diagnostics by spectra from LHD and atomic data
International Nuclear Information System (INIS)
We have observed EUV spectra from the Large Helical Device (LHD) at the National Institute for Fusion Science (NIFS). We measured spectra of impurity ions; carbon, iron, xenon, tin and tungsten ions. In some cases, the plasma evolution was stable and a steady discharge was obtained, but sometimes the plasma underwent radiation collapse and rapid cooling. For carbon and iron spectra, we studied plasma diagnostics by intensity ratios of spectral lines. For other spectra of higher Z element, xenon, tin and tungsten, we studied mainly on line identifications comparing with theoretical calculations and experimental data. Related atomic data for these researches will be also discussed. (author)
2009-04-01
Photobiology and photosynthesis
British Library Electronic Table of Contents (United Kingdom)
To test the hypothesis that leaf level photosynthetic related traits might confer late successionals a competitive advantage over early successionals in low light growth conditions, steady photosynthetic assimilation and dynamic photosynthetic induction related traits were examined in low light grown seedlings with contrasting successional status. Compared with the early successionals, late successionals as a group significantly exhibited lower leaf gas exchange rates. While late successionals required a longer time to respond to simulated sunflecks, they had lower rates of induction losses after sunflecks. Such photosynthetic induction traits allowed late successionals to more effectively utilize subsequent sunflecks. It was observed that plants with lower gas exchange rates responded mor...
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
We perform an optimal-observable analysis of the final charged-lepton/b-quark momentum distributions in {gamma}{gamma}{yields}t t-bar {yields}lX/bX for various beam polarizations in order to study possible anomalous t t-bar {gamma}, tbW and {gamma}{gamma}H couplings, which could be generated by SU(2) x U(1) gauge-invariant dimension-6 effective operators. We find optimal beam polarizations that will minimize the uncertainty in determination of those non-standard couplings. We also compare e e-bar and {gamma}{gamma} colliders from the viewpoint of the anomalous-top-quark-coupling determination.
2005-11-15
Optimal beam polarizations for new-physics search through #gamma##gamma##->#t t-bar #->#lX/bX
International Nuclear Information System (INIS)
We perform an optimal-observable analysis of the final charged-lepton/b-quark momentum distributions in #gamma##gamma##->#t t-bar #->#lX/bX for various beam polarizations in order to study possible anomalous t t-bar #gamma#, tbW and #gamma##gamma#H couplings, which could be generated by SU(2) x U(1) gauge-invariant dimension-6 effective operators. We find optimal beam polarizations that will minimize the uncertainty in determination of those non-standard couplings. We also compare e e-bar and #gamma##gamma# colliders from the viewpoint of the anomalous-top-quark-coupling determination.
2005-11-01
Nuclear astrophysics with radioactive ion beams
International Nuclear Information System (INIS)
Nuclear astrophysics seeks for a possible explanation of the observed abundance distribution of various elements and their isotopes in the universe. Most of the relevant nuclear reactions take place in thermally equilibrium environments with bare nuclei, rather than accelerated and head-on colliding situations with low ionisation states of reactant atoms and molecules that are emulated in the laboratories. Moreover, the temperature of the astrophysical environments is quite often low compared to the centre-of-mass energy of the projectile nuclides, that is required for the reaction to be meaningfully investigated in the laboratory. Therefore, an extrapolation of the data on the reaction cross sections to very low energies and to extremely high density situations is generally called for, which are substantially altered every now and then for a number of astrophysically important reactions. The radioactive ion beams will provide us important data ...
International Nuclear Information System (INIS)
We describe the analysis of forward mutations induced in the tetracycline resistance gene of the plasmid pBR322 by directing the reaction of the carcinogen N-acetoxy-N-2-acetylaminofluorene (N-AcO-AAF) to a small restriction fragment (BamHI, SalI) that is located in the proximal part of the antibiotic-resistance gene. Mutant plasmids obtained both in wild type and excision repair deficient (uvrA) bacterial cells are compared. Preliminary data showing the distribution of the -AAF adducts along this restriction fragments are discussed in relation to the observed spectrum of mutations. 20 references, 4 figures.
Energy Technology Data Exchange (ETDEWEB)
Radionuclide X-ray fluorescence analysis for nondestructive determination of Fe, Zn, Pb, and Br in air samples collected on nitrocellulose membrane filter Synpor 4 is described. A /sup 238/Pu source for the excitation and a semiconductor Si/Li detector for the detection of characteristic and L-fluorescent radiation of the above elements were used. A correction method based upon the measurements of simple or multiple Compton scattering for compensation of varying mass per unit area values in sample deposits was theoretically proposed and experimentally tested. The results obtained both with and without the correction were compared and good agreement with those given by atomic absorption spectrometry was observed.
1981-01-01
Multi walled carbon nanotubes/epilson polylysine nanocomposite with enhanced antibacterial activity
British Library Electronic Table of Contents (United Kingdom)
Abstract Aims: To develop a new nano composite of multi walled carbon nanotubes (MWNTs) with enhanced antimicrobial activity. Methods and Results: A novel antimicrobial nanocomposite [MWNT epilson polylysine (MEPs)] was synthesized via covalent attachment of epilson polylysine on MWNTs with hexamethylene diisocyanate (HDI) as the coupling agent. UV visible spectra and Fourier transform infrared spectra (FT IR) investigations indicate that MEPs is stable, with epilson polylysine leaching effectively eliminated. When compared to MWNTs, the new nano composite MEPs exhibits enhanced antimicrobial activities. In 20 mg l 1 suspensions, significant increases of 72 1, 64 5 and 69% against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus can be observed. The deposited film of MEPs...
2011-01-01
Mother and infant coordinate heart rhythms through episodes of interaction synchrony
British Library Electronic Table of Contents (United Kingdom)
Animal studies demonstrated the powerful impact of maternal-infant social contact on the infant's physiological systems, yet the online effects of social interactions on the human infant's physiology remain poorly understood. Mothers and their 3-month old infants were observed during face-to-face interactions while cardiac output was collected from mother and child. Micro-analysis of the partners' behavior marked episodes of gaze, affect, and vocal synchrony. Time-series analysis showed that mother and infant coordinate heart rhythms within lags of less than 1s. Bootstrapping analysis indicated that the concordance between maternal and infant biological rhythms increased significantly during episodes of affect and vocal synchrony compared to non-synchronous moments. Humans, like other mamm...
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
All-atom molecular dynamics simulations were used to study the morphology of polymer/inorganic composite particles prepared by heterocoagulation. The results were also compared to those of our previous study of the preparation of TiO2/poly(acrylic acid-co-methyl methacrylate) and Fe3O4/polystyrene composite particles. In the simulation system, polymer or inorganic particles were simulated by surface-charge-modified C60 or Na atoms. Through a combination of analysis of the radial distribution functions of charged atoms and snapshots of the equilibrated structure, three kinds of particle distributions were observed under different conditions. When the polymer and inorganic particles had opposite surface charges and their sizes were very different, the composite morphology showed a core-shell...
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
AISI 316L stainless steel was welded by the electron beam (EB) and laser techniques. Microstructural characteristics, hardness profile, creep rupture properties and creep damage of the welds were investigated. Fully austenitic microstructure was obtained in the two welds. The solidification structure of the welds consisted of the cellular and equiaxed dendrites. The creep rupture lives of the two welds were almost the same, and they were reduced by a factor of about two compared to the base metal. Moreover, the rupture elongation of the welds was lower than that of the base metal. Creep damage was observed in the ``parting`` region of the welds and in the heat-affected zone (HAZ), respectively. Final creep fracture occurred in the ``parting`` region of the welds. (orig.).
1995-12-01
International Nuclear Information System (INIS)
AISI 316L stainless steel was welded by the electron beam (EB) and laser techniques. Microstructural characteristics, hardness profile, creep rupture properties and creep damage of the welds were investigated. Fully austenitic microstructure was obtained in the two welds. The solidification structure of the welds consisted of the cellular and equiaxed dendrites. The creep rupture lives of the two welds were almost the same, and they were reduced by a factor of about two compared to the base metal. Moreover, the rupture elongation of the welds was lower than that of the base metal. Creep damage was observed in the ''parting'' region of the welds and in the heat-affected zone (HAZ), respectively. Final creep fracture occurred in the ''parting'' region of the welds. (orig.).
Measurement of induced radioactivity in materials found around a neutron generator
The induced radioactivity in the construction materials of a Cockcroft-- Walton type neutron generator was measured. Major activation products (/sup 24/ Na, /sup 28/Al, /sup 56/Mn, /sup 64/Cu, /sup 65/Ni, /sup 69m/Zn, /sup 88/Rb /sup 91/Sr /sup 101/Mo, /sup 187/W/ and resulting doses are tabulated. Results show that the highest gamma activities would be observed in the fluorescent bulbs, copper pipe, aluminum lattice rod, and the aluminum pipe clamp. Thermoluminescent dosimeter readings yield the highest doses for the copper pipe tee, copper pipe, and aluminum lattice rod. Results of measuremerts of the neutron and gamma dose profiles of the facility are shown. However the indication is clearly that the tritium target, compared to other components, is the major source of radiation both during and after shutdown. (UK)
1974-01-01
Mannose-specific interaction of Lactobacillus plantarum with porcine jejunal epithelium
British Library Electronic Table of Contents (United Kingdom)
Abstract Host-microorganism interactions in the intestinal tract are complex, and little is known about specific nonpathogenic microbial factors triggering host responses in the gut. In this study, mannose-specific interactions of Lactobacillus plantarum 299v with jejunal epithelium were investigated using an in situ pig Small Intestinal Segment Perfusion model. The effects of L. plantarum 299v wild-type strain were compared with those of two corresponding mutant strains either lacking the gene encoding for the mannose-specific adhesin (msa) or sortase (srtA; responsible for anchoring of cell surface proteins like Msa to the cell wall). A slight enrichment of the wild-type strain associated with the intestinal surface could be observed after 8 h of perfusion when a mixture of wild-type and...
2008-01-01
Magnetization transfer contrast effect on multislice fast spin echo
Energy Technology Data Exchange (ETDEWEB)
Magnetization transfer contrast (MTC) on fast spin echo (FSE) images was evaluated in normal brain tissue as well as in brain tumors to better understand contrast of FSE images. On multislice FSE images, attenuation of the signal intensity of brain tissue due to MTC is observed. The rate of MTC (MTR) is obtained by comparing with additional single slice images. The effect of signal attenuation is greater on images with smaller interslice gap, larger number of slices, and longer echo train length. MTR of brain tumors is less than that of normal brain tissue. Among them, meningiomas have relatively high MTR, and cavernous malformation has relatively low MTR. Determination of MTC can be easily specified by obtaining multislice and single slice FSE images, and it may help differentiate brain tumors. (author).
1994-03-01
Jump in the air gasification rate of potassium-doped cellulosic chars
Energy Technology Data Exchange (ETDEWEB)
Chars prepared from potassium-exchanged carboxy methyl cellulose at several heat treatment temperatures (HTTs) were gasified in air isothermally at selected gasification temperatures (GTs) in the range 633-893 K to investigate the catalytic effectiveness of potassium species. The chars displayed a noticeable jump in gasification rate at a particular gasification temperature (called jump temperature, T{sub j}). The magnitude of jump was much less than that reported for copper and nickel catalysis, but comparable with that for calcium catalysis. Increase in HTT caused a decrease in the jump temperature of chars in contrast with the increase observed in copper, nickel and calcium catalysis; also the magnitude of jump did not decrease, but remained unaltered, on increasing HTT. The different behavior of potassium catalysis is correlated to a change in the chemical state of potassium at higher HTT. The results reveal the dependence of jump ...
2010-12-15
International Nuclear Information System (INIS)
This study concerns the Souss upstream basin. The objective is to investigate the characteristics of surface water and groundwater, to assess the impact of artificial recharge as reinforcement of the natural replenishment and assess the renewal of groundwater under semi-arid area. Two major water types are observed: (i) surface waters and upstream springs (least mineralized) and (ii) all groundwater samples (prevailing calcium and magnesium bicarbonate water type). Water isotopes show a low evaporation of precipitations during infiltration. Impoverishment in heavy isotopes is the characteristic of mountain rainfalls, or of a climate colder and wetter than present. Carbon-14 activities (34-94 pmc) indicate a long residence time. The artificial recharge is low compared to the reservoir volume, due to which the renewal rate is also low.
2011-07-01
Ion-induced M X-ray emission from heavy lanthanides
International Nuclear Information System (INIS)
Thick targets of several heavy lanthanide (Ho-Lu) compounds were bombarded by protons and "3He ions of 3 MeV/amu, and M_#alpha# and M_#beta# X-rays were measured with a crystal spectrometer. Ionization probabilities of the N-shell for zero impact parameter were obtained from the X-ray intensity ratio for proton and "3He ion impacts. A shell dependence of the ionization probability was found in a scaling plot. X-ray spectra of lanthanide compounds were compared and no chemical effect was observed. This result is considered to be due to the fact that the main component of M_#alpha# and M_#beta# lines is for radiative transition after the refilling of the 4f orbit (3d"-"14f"n"+"1 #-># 4f"n) where n denotes the number of 4f electrons of the target atom before ionization. (orig.).
1987-12-01
Internal friction of amorphous Pd/sub 80/ Si/sub 20/ metal doped with hydrogen isotopes
Energy Technology Data Exchange (ETDEWEB)
Internal friction of amorphous Pd/sub 80/Si/sub 20/ metal doped with hydrogen or deuterium was measured with a specially designed apparatus using amorphous metal sheet as a part of the electric oscillating circuit. Two peaks in Q/sup -1/ curve are observed. Applying the peak shift method to the first Snoek-like peak, we can determine the relaxation time from which the microdiffusion coefficient can be calculated. The obtained microdiffusion coefficient is about 10/sup -14/ m/sup 2//s at 200 K, being comparable with the macrodiffusion coefficient obtained from the releasing method. It can, however, not elucidate the hydrogen isotopic effect on the peak temperature of Q/sup -1/ curve, the activation energy for relaxation and the relaxation time from the present work because of the broadness of obtained Q/sup -1/ curve.
1983-02-01
Inhibitory activity of Pseudomonas sp. on Flavobacterium psychrophilum, in vitro
British Library Electronic Table of Contents (United Kingdom)
Abstract A Pseudomonas sp. isolate MSB1 efficiently inhibited the growth of Flavobacterium psychrophilum of different serotypes on agar medium. A significant difference in the inhibition was observed between isolates of the less virulent FpT serotype compared to the Fd and Th serotypes. In broth coculture experiments, a low number of cells of MSB1 inhibited and outcompeted the F.psychrophilum cells. Also cell-free culture supernatant of MSB1 clearly repressed the growth of F.psychrophilum. A chromoazurol S assay suggested that MSB1 produced efficient siderophores, which most probably were responsible for the iron deficiency in the supernatant. The limited growth of F.psychrophilum in the supernatant was found to be partly because of the lack of available iron, but the results also indicate...
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
Objective:- To review the rate of inadvertent cystotomy during laparoscopic hysterectomy performed by the Sydney West Advanced Pelvic Surgery Unit (SWAPS). To compare this rate with other published data. To identify the risk factors for bladder injury at laparoscopic hysterectomy and to review the management and outcome following such injury. Method:- This was a retrospective observational study. All hysterectomies where the SWAPS clinical fellow was involved were included. The study period was from January 2001 to June 2009. Simple statistical formulae were used to analyse data in this study. Results:- There were 1223 hysterectomies performed during this period. Eighty-one percent of these were performed laparoscopically. There were 14 (1.1%) bladder injuries reported during this period. ...
2011-01-01
Impact of Hight Velocity Cold Spray Particles
Energy Technology Data Exchange (ETDEWEB)
This paper presents experimental data and an computational model of the cold spray solid particle impact process. Copper particles impacting onto a polished stainless steel substrate are examined. The high velocity impact causes significant plastic deformation of both the particle and the sub- strate, but no melting is observed. The plastic deformation exposes clean surfaces that, under the high impact pressures, result in significant bond strengths between the particle and substrate. Experimental measurements of the splat and crater sizes compare well with the numerical calculations. It is shown that the crater depth is significant and increases with impact velocity. However, the splat diameter is much less sensitive to the impact velocity. It is also shown that the geometric lengths of the splat and crater scale linearly with the diameter of the impacting particle. It is hoped that the results presented will allow better understanding of the ...
1998-12-01
High-field magnetization of CeRh{sub 2}Si{sub 2} and CePd{sub 2}Si{sub 2}
Energy Technology Data Exchange (ETDEWEB)
High-field magnetization properties of single crystalline CeRh{sub 2}Si{sub 2} and CePd{sub 2}Si{sub 2} were investigated. Two-step metamagnetic transition (H{sub c1}=25.4 T and H{sub c2}=26.0 T) was observed in the case of CeRh{sub 2}Si{sub 2}, whereas no anomaly was found in the magnetization process of CePd{sub 2}Si{sub 2} up to 28 T. The mean field analysis has shown that CeRh{sub 2}Si{sub 2} is quite anisotropic compared to CePd{sub 2}Si{sub 2}, which results in the sharp contrast between the magnetization processes of the two compounds.
1998-07-01
High-field magnetization of CeRh_2Si_2 and CePd_2Si_2
International Nuclear Information System (INIS)
High-field magnetization properties of single crystalline CeRh_2Si_2 and CePd_2Si_2 were investigated. Two-step metamagnetic transition (H_c_1=25.4 T and H_c_2=26.0 T) was observed in the case of CeRh_2Si_2, whereas no anomaly was found in the magnetization process of CePd_2Si_2 up to 28 T. The mean field analysis has shown that CeRh_2Si_2 is quite anisotropic compared to CePd_2Si_2, which results in the sharp contrast between the magnetization processes of the two compounds
1997-08-04
Heat and fluid flow during the formation of metallic glasses by splat cooling
A model is presented for heat and fluid flow during hammer and anvil splat cooling. Predictions are made for the effects of superheat and hammer speed on splat thickness, cooling rate, and subsequent glass formation. The regime of Newtonian heat flow is extended well beyond the previously accepted limiting value of Nusselt number. Measurements of the structure, stability, and thickness of Fe{sub 80}B{sub 20} and Pd{sub 80}Si{sub 20} hammer and anvil splats qualitatively confirm the model prediction. Variations of superheat in shock tube splats produced similar trends to those observed in the hammer and anvil device. In an attempt to vary the equivalent of hammer speed in a shock tube device, an orifice producing a supersonic shock wave was utilized. Significant splat flake thickness reductions resulted as compared to subsonic orifices.
Energy Technology Data Exchange (ETDEWEB)
The Bureau of Mines has investigated the hazards of military explosives dispersed as dust clouds in a 20-L test chamber. For purposes of personnel safety, the spark ignitability of the explosives in the form of unconfined dust layers was also studied. The 20-L data show that most of the explosives dusts were capable of sustaining explosions as dust clouds dispersed in air and some dusts were even capable of sustaining explosions when dispersed in nitrogen. The finest sizes of explosives dusts were less reactive than the larger sizes; this is opposite to the particle size effect observed previously for the pure fuel dusts. The data for the explosives dusts were compared to those for pure fuel dusts. 27 refs., 47 figs.
1989-01-01
Grain mantles: The impact on grain evolution and selective extinction
International Nuclear Information System (INIS)
Depletion studies are used to infer the presence of mantles and to constrain grain evolutionary models in the diffuse interstellar medium. The presence of these mantles appears to be important in the evolution of the grains inside diffuse as well as dense clouds. In dense clouds where the element-to-element abundances sometimes differ from those found in diffuse clouds, empirical relationships are starting to emerge between gas abundances and various types of peculiar selective extinction. These peculiar extinction curves may be the results of nonvolatile mantle formation on grain cores or may reflect chemical differences due to variations in the intrinsic metalicity from one cloud to another. A simple model of the time evolution of a parcel of gas and dust as observed by the depletion of two elements is presented. Different studies of grain evolution and selective extinction are discussed and compared.
1989-12-01
Gluino-Squark Production at the LHC: The Threshold
An analysis of the cross section for hadronic production of gluino-squark pairs close to threshold is presented. Within the framework of non-relativistic QCD a significant enhancement compared to fixed order perturbation theory is observed which originates from the characteristic remnants of the gluino-squark resonances below the nominal pair threshold. The analysis includes all colour configurations of S-wave gluino-squark pairs, i.e. triplet, sextet and 15 representation. Matching coefficients at leading order are separately evaluated for all colour configurations. The dominant QCD corrections, arising from initial- and final-state radiation are included. The non-relativistic dynamics of the gluino pair is solved by calculating the Green's function in Next-to-Leading Order (NLO). The results are applied to benchmark scenarios, based on Snowmass Points and Slopes (SPS). As a consequence of the large decay rate of at least one of the ...
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
From their genesis by weathering and sedimentation, bauxites, the principal aluminium ores, contain appreciable amounts of uranium and thorium. High resolution gamma spectrometry with a high purity germanium detector was used for an analysis of four industrially used bauxites from Gondama, Sierra Leone; Boke, Guinea; Weipa, Queensland, Australia; Gove, Northern Territory, Australia. Significant differences in uranium to thorium ratios and in activities of the uranium and thorium daughters were observed for the four bauxites. It was found that the bauxite from Gondama, Sierra Leone has an activity of only 10% compared with the others. Red mud tailings from such a bauxite may well be used as an additive to bricks, which is now illegal for normal red mud from more active bauxites. (author).
1992-01-01
International Nuclear Information System (INIS)
From their genesis by weathering and sedimentation, bauxites, the principal aluminium ores, contain appreciable amounts of uranium and thorium. High resolution gamma spectrometry with a high purity germanium detector was used for an analysis of four industrially used bauxites from Gondama, Sierra Leone; Boke, Guinea; Weipa, Queensland, Australia; Gove, Northern Territory, Australia. Significant differences in uranium to thorium ratios and in activities of the uranium and thorium daughters were observed for the four bauxites. It was found that the bauxite from Gondama, Sierra Leone has an activity of only 10% compared with the others. Red mud tailings from such a bauxite may well be used as an additive to bricks, which is now illegal for normal red mud from more active bauxites. (author).
Fission neutron damage rates and efficiencies in several metals
International Nuclear Information System (INIS)
Initial rates of resistivity-measured low-temperature damage production by fission-spectrum fast neutrons have been determined for 14 metals in the same very well characterized irradiation facility. Six of these metals were fcc, 5 bcc, and 3 hcp. Most were of quite high purity. Observed damage rates, after correction for all known extraneous resistivity-producing effects, were compared with rates predicted by the damage calculation code RECOIL, using parameters chosen from the literature. These parameters, effective displacement threshold energy, E/sub d/, and Frenkel-pair resistivity, rho/sub F/, were in many cases only best estimates, the further refinement of which may be aided by the present results. Damage efficiencies (measured/predicted rates) follow the same trends by crystal classes as seen in other fast-neutron studies.
2003-04-01
Fish intake and acute coronary syndrome
British Library Electronic Table of Contents (United Kingdom)
Aims To study the effect of fish consumption on the risk of acute coronary syndrome (ACS) in healthy subjects. Methods and results This Danish follow-up study included 57 053 men and women between 50 and 64 years. Intake of lean and fatty fish was estimated from a detailed and validated food frequency questionnaire. Potential cases of ACS were identified through nationwide medical databases. A total of 1122 cases of ACS were verified during a mean follow-up period of 7.6 years. Among men, intake of fatty fish was associated with a lower risk of ACS. For men in the highest quintile of fish intake compared with the lowest quintile, the hazard ratio was 0.67 (95% confidence interval: 0.53-0.85). The inverse association was observed for intakes >6 g of fatty fish per day with no obvious additi...
2010-01-01
British Library Electronic Table of Contents (United Kingdom)
The greater amberjack, Seriola dumerilii (Risso 1810) is a semi-pelagic fish and a worldwide species; it is considered a promising candidate for the diversification of Mediterranean aquaculture. In this paper an experimental injection with Listonella (Vibrio) anguillarum was performed to study the immune response of S. dumerilii. Antibody titres to L. anguillarum O1 were determined with indirect-ELISA at different times over a period of 42 days. Results showed that the antibody levels against L. anguillarum were significantly higher in the challenged fish compared to the control. They started developing since the 5th day reaching the highest peak on day 20 after injection, indicating a fast response of the immune system. The observed antibody titre was very high versus L. anguillarum if co...
2008-01-01
Facesheet debonding criteria for composite sandwich panels under in-plane compression
A method for determining the critical debond size between the facesheet and the core in composite sandwich panels under in-plane compression is described. The approach uses fracture mechanics together with a buckling criterion for a debonded faceskin. The technique yields predictions for the critical in-plane compressive load for debond propagation as a function of core-to-faceskin debond size, faceskin thickness, lay-up, composite material properties, and honeycomb properties and geometry. A computer program, developed in this work, calculates the critical buckling load and facesheet deformed shape by solving an eigenvalue problem. The output predicts, for several cases, critical initial debond lengths comparable to those that have been observed on tests on sandwich panels.
1992-07-01
British Library Electronic Table of Contents (United Kingdom)
The thermodynamic characteristics of adsorption (the Henry constant, the heat and entropy of adsorption) of amino acids associates with acetic, trifluoroacetic, nonafluoropentanoic acids and formamide with different values of hydrogen bond lengths and various conformations on a graphitized thermal carbon black (GTCB) were calculated. The experimental results, as the Henry constant, lnK1, and the differences in the molar Gibbs energies, d(DG), obtained by a high performance liquid chromatography (HPLC) on a carbon sorbent Hypercarb, were compared with the values of thermodynamic characteristics of adsorption of the amino acids on the GTCB surface calculated by a molecular-statistical method. A satisfactory correlation was observed between the experimental and calculated values with a coeffi...
2011-01-01
Experimental Comparison of Representation Methods and Distance Measures for Time Series Data
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 measures and their variants, and testing ...
2010-01-01
Evaluation of a temperature model of the continuous steel casting process
Energy Technology Data Exchange (ETDEWEB)
This report summarizes some experiences gathered when using the semi-empirical temperature model that forms the heart of the steel casting advisory system `TUNDTEMP` in simulating the casting process. The model estimates the evolution of the liquid steel temperature in a tundish of a continuous casting machine through a temperature prediction at a couple of central time instants during the casting process. The results are compared with corresponding actual observations during the castings - measured steel temperatures and recorded casting difficulties and interruptions. Explanations for the possible discrepancies are suggested. Starting from a heuristically chosen set of model parameter values, some developing steps have been tested to reduce the simulation errors. The study concentrates mainly on temperature predictions for single heat castings. At the end of the report, some simulations of sequence castings are also briefly discussed
1993-11-01
Estimation of "1"3"7Cs body burden in Japanese, 2
International Nuclear Information System (INIS)
The biological half-life of "1"3"7Cs in the total body of human subjects was determined in 23 individuals of Japanese male adult in their normal works by measuring amount of "1"3"7Cs in both their total body and daily urine in the same period. For the group, the value was determined by averaging the half-lives for individuals, by comparing the mean body burden and the mean daily urinary excretion, or by applying a curve fitting method to the body burden estimate. The biological half-life averaged 86 days, ranging from 50 to 161 days. The averages of the biological half-lives for the group were 83, 87 and 82 days in the different periods of observation. By the curve fitting method, 85 days was found for the group. The biological half-life for the individuals depended on both body weight and age, to a lesser extent, of the subjects. (author).
Estimating a parameter of Burr type XII distribution using hybrid censored observations
British Library Electronic Table of Contents (United Kingdom)
Purpose - Burr distribution has been proved to be a useful failure model. It can assume different shapes which allow it to be a good fit for various lifetimes data. Hybrid censoring is an important way of generating lifetimes data. The purpose of this paper is to estimate an unknown parameter of the Burr type XII distribution when data are hybrid censored. Design/methodology/approach - The problem is dealt with through both the classical and Bayesian point of view. Specifically, the methods of estimation used to tackle the problem are maximum likelihood estimation method and Bayesian method. Empirical Bayesian approach is also considered. The performance of all estimates is compared through their mean square error values. The paper employs Monte Carlo simulation to evaluate the mean square...
2011-01-01
Energy transfer study of europium-tetracycline complexes
Energy Technology Data Exchange (ETDEWEB)
The aim of this work was to study the energy transfer mechanisms from the ligand to the central lanthanide ion of tetracycline-europium (Tc-Eu) complex. The absorption spectra of a EuCl{sub 3}.H{sub 2}O solution was measured and absorption cross-section of Eu{sup 3+} was estimated. The observed overlap predicts a resonant energy transfer from Tetracycline to Eu{sup 3+}. The microscopic parameter of energy transfer was obtained using the overlap integral calculation considering a dipole-dipole energy transfer mechanism and results were compared considering an energy transfer by exchange. In this work, we report also the optical properties of Tc-Eu complex when urea hydrogen peroxide is added to the aqueous solution.
2007-01-15
International Nuclear Information System (INIS)
The absorption spectra of an unoriented single crystal of the title compound (1) have been measured at room and at low temperatures. Assuming a similar sequence of crystal field (CF) levels as for the previously analyzed Nd[N(SiMe_3)_2]_3 (2) a truncated CF splitting pattern is derived from the spectra obtained. The parameters of an empirical Hamiltonian are fitted to the energies of 71 levels to give an r.m.s. deviation of 24.2 cm"-"1. The parameters obtained are compared with those of 2 and Nd[N(SiMe_3)_2]_3(CNC_6H_1_1)_2 (3). The observed trends of CF parameters are consistent with the results of simple model calculations in the framework of the angular overlap model. (orig.)
1998-07-24
Effect of thermal cycling on the alloy 800/2.25 Cr-1 Mo steel joint
International Nuclear Information System (INIS)
The critical part of the trimetallic transition joint (type 304 stainless steel/Alloy 800/2.25 Cr-1 Mo steel), the Alloy 800/2.25 Cr-1 Mo steel joint welded with Inconel 182, was subjected to thermal cycling between room temperature and 873 K. The thermal cycling test procedure used produces accelerated failures in transition joints similar to those observed in steam generators of operating power plants. On thermal cycling, precipitation at the weld/ferritic steel interface decreased on post-weld heat treatment. This precipitation increased with increased prior ageing and applied stress. The results of these tests indicated a considerable improvement in performance of the trimetallic transition joint compared to the direct (bimetallic) transition joint. (orig.).
British Library Electronic Table of Contents (United Kingdom)
To test the effect of humidity on the radiation resistance of Deinococcus radiodurans, air-dried cells were irradiated with germicidal 254?nm UV, and simulated environmental UV or ?-radiation and survival was compared to cells in suspension. It was observed that desiccated cells exhibited higher levels of resistance than cells in suspension toward UV or ?-radiation as well as after 85?C heat shock. It was also shown that low relative humidity improves survival during long-term storage of desiccated D. radiodurans cells. It can be concluded that periods or environments in which cells exist in a dehydrated state are beneficial for D. radiodurans? survival exposed to various other stresses.
2011-01-01
Dissipative dynamics of circuit-QED in the mesoscopic regime
We investigate the behavior of a circuit QED device when the resonator is initially populated with a mesoscopic coherent field. The strong coupling between the cavity and the qubit produces an entangled state involving mesoscopic quasi-pointer states with respect to cavity dissipation. The overlap of the associated field components results in collapse and revivals for the Rabi oscillation. Although qubit relaxation and dephasing do not preserve these states, a simple analytical description of the dissipative dynamics of the circuit QED device including cavity relaxation as well as qubit dissipation is obtained from the Monte-Carlo approach. Explicit predictions for the spontaneous and induced Rabi oscillation signals are derived and sucessfully compared with exact calculations. We show that these interesting effects could be observed with a 10 photon field in forthcoming circuit QED experiments.
2007-01-01
Dispersion of Spilled Heavy Oil by Impinging Waterjet
The purpose of this study is to search for a new method of dispersing spilled heavy oil, which has a detrimental effect on the natural environment and marine ecosystem. A method ejecting a waterjet vertically downward to heavy oil on the water surface was studied, particularly focusing on the effect of the guide nozzle shape. The waterjet comprised heavy oil and minute air bubbles, and passed through the hole of the guide nozzle. Thirteen guide nozzle shapes were tested and compared. The dispersion efficiency of a tapered hole was the best among the 13 nozzles. The flow in the hole of the guide nozzles was recorded by a high-speed video camera. The occurrence of two flows, regular and counter flows, was observed in the taper guide nozzle. It seemed that the counter flows generated the shearing force between the waterjet and the heavy oil layer. It is considered that the shearing force determines the surplus efficiency of disperse.
2009-01-01
Dielectric properties of sols of silver nanoparticles capped by alkyl carboxylate ligands
British Library Electronic Table of Contents (United Kingdom)
Sols of silver nanoparticles in toluene were studied by broadband dielectric spectroscopy (10?3?105 Hz). The frequency dependences of the specific alternating current (ac) conductivity and the complex electric modulus were used to estimate the temperature/frequency intervals of long- and short-range charge transfer occurs, respectively. A considerable increase (by more than 30 ?C) in the Vogel temperature T 0 and the glass transition temperature T g in sols compared with the pure solvent was found. It can be hypothesized that these cooperative effects reflect the initial stage of the superlattice formation. Although the dielectric characteristics of sols are generally controlled by the conductivity relaxation, the dielectric response was observed in the high-frequency range (1?103 Hz) at l...
2011-01-01
Development of an advanced power system stabilizer using a strict linearization approach
Energy Technology Data Exchange (ETDEWEB)
This paper presents a practical design for a power system stabilizer using the differential geometric linearization approach. This stabilizer uses the information at the secondary bus of the step-up transformer as input signals, enabling its application to multi-machine power systems. The stabilizer makes it possible to obtain all necessary information within its own power station without observing an equivalent reactance in other power systems. To evaluate the dynamic performance of this stabilizer, the authors tested it on a multi-machine system model using the computer. The simulation results showed that the stabilizer offered good dynamic performance and robustness compared with conventional power system stabilizers, thus confirming its very effective and practical application in power system stabilization.
1996-05-01
Development of a detailed kinetic model for gasoline surrogate fuels
Energy Technology Data Exchange (ETDEWEB)
A detailed chemical kinetic model to describe the autoignition of gasoline surrogate fuels is presented consisting of the fuels iso-octane, n-heptane, toluene, diisobutylene and ethanol. Model predictions have been compared with shock tube ignition delay time data for surrogates of gasoline over practical ranges of temperature and pressure, and the model has been found to be sensitive to both changes in temperature and pressure. Moreover, the model can qualitatively predict the observed synergistic and antagonistic non-linear blending behaviour in motor octane number (MON) for different combinations of primary reference fuels (PRFs) and non-PRFs by correlating calculated autoignition delay times from peak pressures and temperatures in the MON test to experimental MON values. The reasons for the blending behaviour are interpreted in terms autoignition chemistry. 37 refs., 11 figs., 4 tabs.
2008-08-15
International Nuclear Information System (INIS)
The simultaneous hydrogen and silicon atom densities in amorphous silicon, a-Si, films prepared by the glow discharge technique have been measured by 25 MeV #alpha#-particle elastic scattering. Integrated band intensities for the silicon-hydrogen stretching modes, #omega#_1sup(s) and #omega#_2sup(s) in the region 1800 to 2200 cm"-"1 were determined for the same freely supported films. A similar analysis has been carried out for the bands observed at 890, 840 and 640 cm"-_1. Effective oscillator strengths for the #omega#_1sup(s) and #omega#_2sup(s) modes in a-Si films have been estimated and compared with the current theories on the effect of the silicon matrix on the infrared absorption characteristics. (author).
Determination of selected microelements in polish herbs and their infusions
Energy Technology Data Exchange (ETDEWEB)
Ba, Cd, Cr, Cu, Fe, Ni, Pb and Zn were determined in birch leaves (Folium Betulae), dandelion roots (Radix Taraxacae), hawthorn blossom (Inflorescentia Crataegi) and their infusions by graphite furnace atomic absorption spectrometry (GFAAS) after microwave digestion of plant samples. Infusions were made from herbs according to prescription for patients, provided by the producer of medicine on the package. The results obtained were compared with daily requirements for each element. Results show high content of cadmium in the medicinal plants analyzed. The highest level in infusions was observed for Ni and Zn (over 90% of the total element concentration for Ni and in most cases over 50% for Zn), and the lowest for Cd and Pb. The calculated daily intake of majority of the analyzed elements was very low (under 1% of daily requirements)
2007-08-01
Energy Technology Data Exchange (ETDEWEB)
The deterioration of AA2024, AA6061 and AA7475 anodised in an environmentally-compliant tartaric acid/sulphuric acid electrolyte has been examined as a function of the immersion time in the electrolyte after termination of anodising. By transmission electron microscopy and scanning electron microscopy, degradation of the porous oxide film was qualitatively observed on AA2024. Electrochemical impedance spectroscopy revealed that AA2024 and AA7075 were more sensitive to prolonged immersion in the anodising electrolyte compared with AA6061, due to increased barrier layer thinning rates and increased susceptibility to localized corrosion. Salt spray tests confirmed the previous, indicating decay of anticorrosion performance for AA2024 and AA7075.
2010-07-15
Energy Technology Data Exchange (ETDEWEB)
Because of the importance of water vapor, the ARM program initiated a series of three intensive operating periods (IOPs) at its CART (Cloud And Radiation Testbed) site. The goal of these IOPs is to improve and validate the state-of-the-art capabilities in measuring water vapor. To date, two of the planned three IOPs have occurred: the first was in September of 1996, with an emphasis on the lowest kilometer, while the second was conducted from September--October 1997 with a focus on both the upper troposphere and lowest kilometer. These IOPs provided an excellent opportunity to compare measurements from other systems with those made by the CART Raman lidar. This paper addresses primarily the daytime water vapor measurements made by the lidar system during the second of these IOPs.
1998-04-01
International Nuclear Information System (INIS)
The activity of tyrosine aminotransferase (TAT) in the liver of mice subjected simultaneously to ionizing radiation and to local inflammatory process showed in the first 24 hours of the experiment statistically significant changes resulting from summation of the harmful effects of both factors. In the second 24-hour period an evident tendency was observed for return of a normal circadian rhythm of the enzyme. This points to presence of an endogenous mechanism of suppression of the manifestations of significant desynchronization of the circadian rhythm. The paper contains also a trial of mathematical analysis of changes in TAT activity in the circadian rhythm, a description and analysis or the suppression process, qualitative and quantitative determination of the phenomenon of cumulation of the effects of powerful stress factors acting on the animal organism. The obtained results were compared with the results of investigations of TAT activity ...
1980-01-01
International Nuclear Information System (INIS)
Off-axis electron holography is used to characterize a linear array of transistors, which was prepared for examination in cross-sectional geometry in the transmission electron microscope (TEM) using focused ion beam (FIB) milling from the substrate side of the semiconductor device. The measured electrostatic potential is compared with results obtained from TEM specimens prepared using the more conventional 'trench' FIB geometry. The use of carbon coating to remove specimen charging effects, which result in electrostatic fringing fields outside 'trench' specimens, is demonstrated. Such fringing fields are not observed after milling from the substrate side of the device. Analysis of the measured holographic phase images suggests that the electrically inactive layer on the surface of each FIB-milled specimen typically has a thickness of 100 nm.
2005-04-01
Comparative planetology, climatology and biology of Venus, Earth and Mars
British Library Electronic Table of Contents (United Kingdom)
Spacecraft studies of the three terrestrial planets with atmospheres have made it possible to make meaningful comparisons that shed light on their common origin and divergent evolutionary paths. Early in their histories, all three apparently had oceans and extensive volcanism; Mars and Earth, at least, had magnetic fields, and Earth, at least, had life. All three currently have climates determined by energy balance relationships involving carbon dioxide, water and aerosols, regulated by solar energy deposition, atmospheric and ocean circulation, composition, and cloud physics and chemistry. This paper addresses the extent to which current knowledge allows us to explain the observed state of each planet, its planetology, climatology and biology, within a common framework. Areas of ignorance...
2011-01-01
Chemical absorption of carbon dioxide with aqueous sodium hydroxide solution spray
Energy Technology Data Exchange (ETDEWEB)
Measurements of local mass fluxes of liquid, local number fluxes of the drop and local drop size distributions at various locations in the test column were made for wide ranges of liquid flow rates and gas flow rates. An empirical correlation for the volume mean diameter of the drop at the nozzle exit was proposed. Measurements of the rates of absorption of carbon dioxide from carbon dioxide-air mixtures with water sprays (physical absorption) and aqueous sodium hydroxide sprays (chemical absorption) were made for wide range so fluid flow rates, feed gas concentrations, and initial alkali concentrations. The observed dimensionless rates of absorption were compared with the theoretical values by assuming penetration model with second-order irreversible reaction. 11 refs., 7 figs.
1996-12-31
Assessment of effects of Fort St. Vrain HTGR primary coolant on Alloy 800. Final report
Energy Technology Data Exchange (ETDEWEB)
A comprehensive review was conducted of primary helium coolant chemistry data, based on current and past operating histories of helium-cooled, high-temperature reactors (HTGRs), including the Fort St. Vrain (FSV) HTGR. A reference observed FSV reactor coolant environment was identified. Further, a slightly drier expected FSV coolant chemistry was predicted for reactor operation at 100% of full power. The expected environment was compared with helium test environments used in the US, United Kingdom, Germany, France, and Japan. Based on a comprehensive review and analysis of mechanical property data reported for Alloy 800 tested in controlled-impurity helium environments (and in air when appropriate for comparison), an assessment was made of the effect of FSV expected helium chemistry on material properties of alloy 800, with emphasis on design properties of the Alloy 800 material utilized in the FSV steam generators.
1982-08-01
Assessment of effects of Fort St. Vrain HTGR primary coolant on Alloy 800. Final report
International Nuclear Information System (INIS)
A comprehensive review was conducted of primary helium coolant chemistry data, based on current and past operating histories of helium-cooled, high-temperature reactors (HTGRs), including the Fort St. Vrain (FSV) HTGR. A reference observed FSV reactor coolant environment was identified. Further, a slightly drier expected FSV coolant chemistry was predicted for reactor operation at 100% of full power. The expected environment was compared with helium test environments used in the US, United Kingdom, Germany, France, and Japan. Based on a comprehensive review and analysis of mechanical property data reported for Alloy 800 tested in controlled-impurity helium environments (and in air when appropriate for comparison), an assessment was made of the effect of FSV expected helium chemistry on material properties of alloy 800, with emphasis on design properties of the Alloy 800 material utilized in the FSV steam generators.
Are Stars with Planets Polluted?
We compare the metallicities of stars with radial velocity planets to the metallicity of a sample of field dwarfs. We confirm recent work indicating that the stars-with-planet sample as a whole is iron rich. However, the lowest mass stars tend to be iron poor, with several having [Fe/H]0.48) that contributes to but does not explain the mass-metallicity trend in the stars-with-planets sample. We use Monte Carlo models to show that adding an average of 6.5 Earth masses of iron to each star can explain both the mass-metallicity and the age-metallicity relations of the stars-with-planets sample. However, for at least one star, HD 38529, there is good evidence that the bulk metallicity is high. We conclude that the observed metallicities and metallicity trends are the result of the interaction of three effects; accretion of about 6 Earth masses of iron rich material, selection effects, and in some cases, high intrinsic metallicity.
2002-01-01
Application of a prognostic model validation system to real-time dispersion modeling
Energy Technology Data Exchange (ETDEWEB)
The Atmospheric Release Advisory Capability (ARAC) at the Lawrence Livermore National Laboratory uses the U.S. Navy's Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS) to supply high-resolution wind data for use in its real-time dispersion modeling system. ARAC has used COAMPS products to support several events and exercises, and COAMPS forecasts appear accurate, based on qualitative examination. Recently ARAC has developed a quantitative verification system which calculates COAMPS error and bias statistics, comparing COAMPS forecasts of various lengths with observational data. This paper shows how this system has been used to guide ARAC operators, who need an estimate of the likely behavior of COAMPS forecasts of various lengths in different regions, seasons, and weather patterns.
1999-10-18
Analysis of recent {eta} photoproduction data
Energy Technology Data Exchange (ETDEWEB)
Recent data on {eta} -meson photoproduction off a proton target in the energy range 2 {<=}{radical}(s){<=} 3 GeV are analyzed with regard to their overall consistency. Results from the ELSA and CLAS measurements are compared with predictions of a Regge model whose reaction amplitude was fixed via a global fit to pre-2000 measurements of differential cross sections and polarization observables for {gamma}p{yields}{eta}p at higher energies. We find that all recent experimental results on differential cross sections for {eta} -meson photoproduction are in good agreement with each other, except for the CLAS data from 2009. However, the latter can be made consistent with the other data at the expense of introducing an energy-dependent renormalization factor. We point out that there are indications in the data for a possible excitation of baryon resonances with masses around 2.1 and 2.4GeV. (orig.)
2010-12-15
An application of artificial neural networks in breast cancer recognition using scintimammography
International Nuclear Information System (INIS)
The aim of the study was to assess the usefulness of artificial neural networks (ANN) application in evaluation of scintimammography in the context of clinical data in the diagnosis of breast cancer. The results produced by ANN were compared with the diagnosis of two independent observers, nuclear medicine specialists. Material and methods: The clinical data and the numerical values derived from scintimammograms of 103 patients were the material for the study. The reference method was the result of histopathology study (core biopsy and /or FNB). Results: The overall sensitivity of physician diagnosis was 78% with specificity of 72%. The ANN produced 71% sensitivity and specificity of 73%. The physicians and ANN results were not significantly different (p=0.4619). Conclusions: Artificial neutral networks are useful tool in clinical diagnosis of breast cancer. (authors)
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.
AFM Imaging of SWI/SNF action: mapping the nucleosome remodeling and sliding
We propose a combined experimental (Atomic Force Microscopy) and theoretical study of the structural and dynamical properties of nucleosomes. In contrast to biochemical approaches, this method allows to determine simultaneously the DNA complexed length distribution and nucleosome position in various contexts. First, we show that differences in the nucleo-proteic structure observed between conventional H2A and H2A.Bbd variant nucleosomes induce quantitative changes in the in the length distribution of DNA complexed with histones. Then, the sliding action of remodeling complex SWI/SNF is characterized through the evolution of the nucleosome position and wrapped DNA length mapping. Using a linear energetic model for the distribution of DNA complexed length, we extract the net wrapping energy of DNA onto the histone octamer, and compare it to previous studies.
2007-01-01
A study of binary mixture boiling: boiling site density and subcooled heat transfer
Energy Technology Data Exchange (ETDEWEB)
(Boiling site densities and heat-transfer coefficients have been measured for ethanol-water and ethanol-benzene mixtures at 1.01 bar for a heated vertical brass disk. A strong effect of composition on the boiling site density was observed, which was attributed to the nature of the activation of the boiling surface and mass diffusion effects. The boiling heat-transfer coefficient was found to decrease with increasin subcooling, but for the mixtures at a given level of subcooling the decrease was less than that for the single components and azeotropic mixtures.) The heat-transfer coefficient at a given heat flux was seen to be quite insensitive to the very large increase in boiling site density in comparing the pure water and the ethanol-water azeotrope results, leading one to question pool boiling models that predict heat-transfer rates on the basis of boiling site density.
1985-05-01
A note on the flow and heat transfer enhancement in a channel with built-in winglet pair
International Nuclear Information System (INIS)
Counter rotating longitudinal vortices produced by winglet in a channel are known to enhance heat transfer. In the present investigation the flow structure and heat-transfer enhancement by a winglet pair of non-zero thickness has been studied. A delta winglet pair type vortex generator is placed in a hydrodynamically developed and thermally developing laminar channel flow. Computations are done by solving the unsteady, three-dimensional, incompressible Navier-Strokes equations and energy equation using a modified Marker-and-Cell (MAC) method. The flow structure is complex and consists of main, corner and induced vortices. It is observed that as compared to a channel without winglets, the heat transfer is enhanced by 33% when single winglet is used and by 67% when a winglet pair is employed. Effects of thickness of the winglets and Reynolds number on the heat transfer augmentation are presented.
2007-04-01
British Library Electronic Table of Contents (United Kingdom)
A superhydrophobic SiO2/nylon 6,6 nanocomposite coating was fabricated by a facile casting process. Compared with the intrinsically hydrophilic pure nylon 6,6, the as-prepared coating displayed a superhydrophobic property in the pH range from 1 to 14. It was also found that the resulting water contact angles of the as-prepared surface were always larger than 159?, but the sliding angles had an obvious decrease from about 33.4??1? as the content of SiO2 nanoparticles increased. In addition, a transition from the transitional superhydrophobic state between Wenzel?s and Cassie?s state to the Cassie?s state was observed.
2011-01-01
The natural background approach to setting radiation standards
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 ...
1979-03-09
Purpose: The purpose of this study was to compare nutrient content and cost of home-packed lunches to nutrient standards and prices for reimbursable school lunches. Methods: Researchers observed food and beverage contents of 333 home packed lunches at four north Texas elementary schools. Nutritionist Pro was used to analyze lunches for calories, total fat, saturated fat, protein, fiber, vitamin A, vitamin C, calcium, iron, fiber, and sodium content. These values were then compared to National School Lunch Program (NSLP) standards and other nutrient standards. Cost of each home-packed lunch was estimated based on food prices at three local supermarkets. A one-sample t-test (p = 0.05) was used to compare nutrient values of home packed lunches to National School Lunch Program (NSLP) standards. A paired t-test was used to compare cost of home packed lunches to each school's full price ...
2008-12-01
Bombyx mandarina nucleopolyhedrovirus (BomaNPV) is a variant of Bombyx mori nucleopolyhedrovirus (BmNPV). BomaNPV S1 strain has been reported to be significantly less virulent than the BmNPV T3 strain via the oral infection route in B. mori larvae, but other features of S1 including budded virus (BV) infectivity and virus propagation in cultured cells are still unknown. In this study, we compared BV infectivity of S1 and T3 in B. mori larvae and cultured cells. Larval bioassays by intrahemocoelic BV injection revealed that the median lethal dose of S1's BV was approximately three times lower than that of T3. In addition, S1 produced more BVs and occlusion bodies (OBs) in the hemolymph of B. mori larvae compared with T3. Furthermore, we observed that the locomotion was enhanced earlier and the median lethal time was shorter in S1-infected larvae compared with those in T3-infected larvae. Western blot ...
2011-05-22
Am/Cm canister temperature evaluation in CIM5
Energy Technology Data Exchange (ETDEWEB)
To facilitate the evaluation of alternate canister designs, 2 canisters were outfitted with thermocouples at elevations of 1/2, 3 1/2, and 6 1/2 inches from the canister bottom. The canisters were fabricated from two inch diameter schedule 10 and two inch diameter schedule 40 stainless steel pipe. Each canister was filled with approximately 2 kilograms of 49 wt percent lanthanide (Ln) loaded 25SrABS glass during 5 inch Cylindrical Induction Melter (CIM5) runs for TTR Tasks 3.03 and 4.03. Melter temperature, total mass of glass poured, and the glass pour rates were almost identical in both runs. The schedule 40 canister has a slightly smaller ID compared to the schedule 10 canister and therefore filled to a level of 9.5 inches compared to 8.0 inches for the schedule 40 canister. The schedule 40 canister had an empty mass of 1906 grams compared to 919 grams for the schedule 10 canister. The schedule 10 canister was found to ...
2000-02-17
Aerosol composition, chemistry, and source characterization during the 2008 VOCALS Experiment
Energy Technology Data Exchange (ETDEWEB)
Chemical composition of fine aerosol particles over the northern Chilean coastal waters was determined onboard the U.S. DOE G-1 aircraft during the VOCALS (VAMOS Ocean-Cloud-Atmosphere-Land Study) field campaign between October 16 and November 15, 2008. SO42-, NO3-, NH4+, and total organics (Org) were determined using an Aerodyne Aerosol Mass Spectrometer, and SO42-, NO3-, NH4+, Na+, Cl-, CH3SO3-, Mg2+, Ca2+, and K+ were determined using a particle-into-liquid sampler-ion chromatography technique. The results show the marine boundary layer (MBL) aerosol mass was dominated by non- sea-salt SO42- followed by Na+, Cl-, Org, NO3-, and NH4+, in decreasing importance; CH3SO3-, Ca2+, and K+ rarely exceeded their respective limits of detection. The SO42- aerosols were strongly acidic as the equivalent NH4+ to SO42- ratio was only ~0.25 on average. NaCl particles, presumably of sea-salt origin, showed chloride deficits but retained Cl- typically more than half the equivalency of Na+, and are ...
2010-03-15
Transient enhanced diffusion from decaborane molecular ion implantation
Energy Technology Data Exchange (ETDEWEB)
Transient enhanced diffusion (TED) from implantation of 5thinspkeVthinspB{sub 10}H{sub 14} and 0.5 keV B ions has been quantified and compared for nominal boron doses of 10{sup 14} and 10{sup 15}thinspcm{sup {minus}2}. Boron diffusivity during annealing was extracted from secondary ion mass spectroscopy depth profiles of diffused marker layers in boron doping-superlattices and the actual implanted B dose was independently measured by nuclear reaction analysis. Comparable enhancements were observed from both ions. Transmission electron microscopy analysis revealed that both boron- and decaborane-implanted samples were amorphized at a nominal 10{sup 15}thinspcm{sup {minus}2}thinspB dose. A comparison with data from low energy Si implants revealed a similar dependence of diffusivity enhancement on implant dose. These findings are consistent with the understanding that TED is caused by the interstitial supersaturation resulting ...
1998-10-01
Transient enhanced diffusion from decaborane molecular ion implantation
International Nuclear Information System (INIS)
Transient enhanced diffusion (TED) from implantation of 5keVB_1_0H_1_4 and 0.5 keV B ions has been quantified and compared for nominal boron doses of 10"1"4 and 10"1"5cm"-"2. Boron diffusivity during annealing was extracted from secondary ion mass spectroscopy depth profiles of diffused marker layers in boron doping-superlattices and the actual implanted B dose was independently measured by nuclear reaction analysis. Comparable enhancements were observed from both ions. Transmission electron microscopy analysis revealed that both boron- and decaborane-implanted samples were amorphized at a nominal 10"1"5cm"-"2B dose. A comparison with data from low energy Si implants revealed a similar dependence of diffusivity enhancement on implant dose. These findings are consistent with the understanding that TED is caused by the interstitial supersaturation resulting from a number of excess interstitials approximately equal to the ...
1998-10-01
Thermal action of 2. 45 GHz microwaves on the cytoplasm of Chinese hamster cells
Energy Technology Data Exchange (ETDEWEB)
In order to demonstrate possible specific effects of microwaves at the cellular level V-79 Chinese hamster cells were exposed to 2.45-GHz radiation at power levels of 20-200 mW/cm2 and at specific absorption rates of 10-100 mW/g. Intracellular cytoplasmic changes were observed by fluorescence polarization using a method based on the intracellular enzymatic hydrolysis of nonfluorescent fluorescein diacetate (FDA). At levels of absorbed energy below 90 J/g, modifications of microviscosity and mitochondrial state were absent, but a slight stimulation of enzymatic hydrolysis of FDA was observed which may be explained by microwave-induced alterations of cellular membranes possibly due to differences in heating pattern of microwaves compared to water-bath heating. At levels of absorbed energy above 90 J/g, the decrease of enzymatic hydrolysis of FDA, increase in degree of polarization, and increase of permeation of the ...
1984-01-01
Synopsis of some preliminary computational studies related to unsaturated zone transport at Area G
Energy Technology Data Exchange (ETDEWEB)
Computational transport models are described with applications in three problem areas related to unsaturated zone moisture movement beneath Area G. These studies may be used to support the ongoing maintenance of the site Performance Assessment. The three areas include: a 1-D transient analysis with average tuff hydraulic properties in the near surface region with computed results compared to field data; the influence on near surface transient moisture percolation due to realistic distributions in hydraulic properties derived statistically from the observed variance in the field data; and the west to east moisture flow in a 2-D steady geometry approximation of the Pajarito Plateau. Results indicate that a simple transient model for transport of moisture volume fraction fits field data well compared to a moisture pulse observed in the active disposal unit, pit 37. Using realistic infiltration boundary ...
1998-03-01
Steam generator local water chemistry and SCC of austenitic steel
Energy Technology Data Exchange (ETDEWEB)
The titanium stabilized austenitic steel similar to the type of 321 is sensitive to the stress corrosion crackingunder horizontal steam generator operating condition. SCC was observed under crevice corrosion parameters and has resulted in the transgranular or intergranular cracking at the both, components primary collectors and heat exchange tubes. The crevice environment is characterized by aggressive impurities and 'non aggressive' compounds. Sulfates and chlorides as aggressive species and silicates and alumino-silicates as 'non aggressive' species on the other hand are present in significant amount in the crevice environment under operating condition. Local water chemistry parameters were evaluated with MULTEQ Code. As input data the measured operational values of local and bulk environments have been used. The determined parameters were compared with the results of thread hole environment analyses and ...
1998-07-01
Regeneration of granular activated carbon using hydrothermal technology
Energy Technology Data Exchange (ETDEWEB)
The economic feasibility of using granular activated carbon (GAC) to remove organic contaminants from industrial and municipal wastewater is contingent upon its reuse during multiple adsorption-regeneration cycles. The most common process for the regeneration of GAC is the thermal method. Drawbacks associated with thermal regeneration include a 5--10% loss of carbon due to oxidation and attrition, a decrease in adsorption capacity, and high energy costs. The purpose of this study was to investigate the regeneration of GAC using hydrothermal technology. Phenol contaminated and non-contaminated GAC samples were regenerated using supercritical water (411 deg C and 26.2 MPa) with dissolved oxygen concentrations of 0 mg/L, 5 mg/L, and 100 mg/L. For comparative purposes, GAC was regenerated using subcritical water (300 deg C and 12.4 MPa) with a dissolved oxygen concentration of 5 mg/L. Regenerated GAC samples were evaluated in terms of adsorption capacity, BET surface ...
1999-05-01
Protein expression in white spot syndrome virus infected Penaeus monodon fabricius.
White spot syndrome virus (WSSV) is the causative agent of the white spot disease of shrimp. Penaeus monodon were captured from Muttukadu Estuary in Chennai, India, transported to the laboratory and maintained in an aerated system with continuous water circulation-biofiltration. WSSV-free P. monodon were challenged by feeding them only once with WSSV-infected tissues of P. monodon. Cumulative mortality (100%) of the infected individuals was determined. Tissues from infected and uninfected shrimp such as muscles, hepatopancreas, heart, gills and eye tissues (100mg of each) and haemolymph (50 microl) were subjected to SDS-PAGE. In infected muscle tissue, six newly expressed proteins were detected. In infected haemolymph, four new proteins and three intensely expressed high molecular weight proteins were observed. Three intensely expressed high molecular weight proteins were detected in infected heart tissue and two new proteins in infected hepatopancreatic tissues. ...
2005-06-01
Energy Technology Data Exchange (ETDEWEB)
The adhesion of a Mg:Ag cathode to the tris-(8-hydroxyquinoline) aluminum (Alq{sub 3}) in organic light emitting devices (OLEDs) can be greatly enhanced by a remote plasma treatment of the Alq{sub 3} layer using either air or N{sub 2} prior to metal deposition. The altered surface properties which lead to increased sticking coefficients of Mg and Ag, as well as enhanced adhesion, are attributed to the introduction of new functional groups into the organic layer, as observed by X-ray photoelectron spectroscopy (XPS). The storage life of the plasma treated devices in air without any capping treatment, as judged by a visible deterioration of the cathode, was increased by approximately five to six times compared to untreated OLEDs. Current-voltage characteristics and EL efficiency, however, were shown to deteriorate for devices incorporating either an air or an N{sub 2} plasma treated Alq{sub 3} layer. For OLEDs subjected to short treatment times ...
2004-05-31
International Nuclear Information System (INIS)
To evaluate the diagnostic performance of commercially available CRT monitors used in a teleradiology system by determining the rate of detection of simulated lung nodules. Three types of CRT monitors were tested in the observation study. They had matrix sizes of 1024 x 768 (16 inches, color), 1024 x 768 (20 inches, color) and 1600 x 1125 (24 inches, black and white). Twenty chest radiographs were obtained by Fuji computed radiography (FCR) of an anthropomorphic chest phantom with ten simulated nodules on its surface. These FCR films were digitized by a film digitizer with 125 DPI (1024 x 1024 matrix sizes) and 12 bit gray scales, and the image data were transferred from Shinshu University Hospital to other hospitals where interpretation was carried out by the radiologists. Ten radiologists of three hospitals were asked to interpret independently both the original FCR films and the images shown on the CRT monitors and to indicate the presence or absence of ...
Ramsar, a city in the northern Iran, has the highest level of natural background radiation in the world. It has been clearly shown that low doses of ionising radiation can induce resistance to subsequent higher exposures. This phenomenon is termed radioadaptive response. We have compared induction of cytogenetic radioadaptive response by High Natural Background Radiation (HNBR) in Ramsar and X-ray occupational exposure as conditioning doses in human peripheral blood lymphocytes. 30 healthy control individuals, living in Ramsar but in normal background radiation areas, 15 healthy individuals from Talesh Mahalleh, a region with extraordinary high level of background radiation, and 7 X-ray radiographers working in Ramsar hospital located in normal natural background ionising radiation area were evaluated. Peripheral blood samples were prepared and exposed to challenge dose of 0 and 2 Gy. Lymphocytes were scored using analysis of metaphase, for the presence of ...
2003-01-01
Minerals and trace elements determination in diets by neutron activation analysis
International Nuclear Information System (INIS)
In the present study 12 diets, each one consisting of a pool of seven day diets, composed by four meals: breakfast, lunch, dinner and snack, adequate in energy and macro nutrients according to the RDA (Recommended Daily Allowance) recommendations, were elaborated and offered to a group of 12 men (19-42 years). The diets were collected by duplicate portion technique and dried by two different processes: freeze drying and 60 deg C ventilated oven drying. In the total, 24 diets were analyzed. The content of some minerals and trace elements (Ca, Fe, Mg, Mn, Na, Se and Zn) were determined by Instrumental Neutron Activation Analysis. The validation of methodology was made by analysis of the reference materials Typical Diet (NIST SRM 1548"a), Orchard Leaves (NIST SRM 1541) and Peach Leaves (NIST SRM 1547). The results observed by two different drying processes used were statistically compared by test T of Student. It was possible to conclude that the ...
2002-08-11
MONTE CARLO SIMULATIONS OF GLOBULAR CLUSTER EVOLUTION. V. BINARY STELLAR EVOLUTION
International Nuclear Information System (INIS)
We study the dynamical evolution of globular clusters containing primordial binaries, including full single and binary stellar evolution using our Monte Carlo cluster evolution code updated with an adaptation of the single and binary stellar evolution codes SSE and BSE from Hurley et al. We describe the modifications that we have made to the code. We present several test calculations and comparisons with existing studies to illustrate the validity of the code. We show that our code finds very good agreement with direct N-body simulations including primordial binaries and stellar evolution. We find significant differences in the evolution of the global properties of the simulated clusters using stellar evolution compared with simulations without any stellar evolution. In particular, we find that the mass loss from the stellar evolution acts as a significant energy production channel simply by reducing the total gravitational binding energy and can significantly ...
2010-08-10
International Nuclear Information System (INIS)
Cigarette smoking is the major environmental risk factor for bladder cancer in humans. Aromatic amines, potent DNA-reactive bladder carcinogens present in cigarette smoke, contribute significantly. However, increased cell proliferation, caused by direct mitogenesis or in response to cytotoxicity, may also play a role since urothelial hyperplasia has been observed in human cigarette smokers. We examined the urothelial effects of cigarette smoke (whole body inhalation exposure (Teague) system) in female C57BL/6 mice at various times in two studies, including reversibility evaluations. In both studies, no urothelial hyperplasia was observed by light microscopy in any group. However, in study 1, the Ki-67 labeling index (LI) of the urothelium was significantly increased in the smoke exposed group compared to controls through 3 months, but was not present at 6, 9 or 12 months even with continued exposures. In the groups that ...
2007-11-20
Influence of local waste burning on atmospheric aerosol properties in urban environment
International Nuclear Information System (INIS)
Aerosols affect the radiative energy budget on both the regional and global scales. The wavelength-dependent aerosol optical depth (AOD) is a fundamental determinant of the amount by which extra-terrestrial incoming sunlight and outgoing terrestrial radiation are being attenuated in the atmosphere. The present study addresses the influence of local waste burning on aerosol characteristics, black carbon (BC) aerosol mass concentration and spectral solar irradiance using ground-based measurements over the tropical urban environment of Hyderabad, India. AOD has been observed to be maximum during burning days compared to normal days. Aerosol size spectra suggest bimodal distributions during pre-and post-burning periods and trimodal distributions during burning periods. Angstrom wavelength exponent estimated from spectral variation of AOD suggested dominance of accumulation mode particle loading during burning days compared to ...
2006-03-01
International Nuclear Information System (INIS)
In July 2005 a new algorithm was released by Varian Medical Systems for the Eclipse planning system and installed in our institute. It is the anisotropic analytical algorithm (AAA) for photon dose calculations, a convolution/superposition model for the first time implemented in a Varian planning system. It was therefore necessary to perform validation studies at different levels with a wide investigation approach. To validate the basic performances of the AAA, a detailed analysis of data computed by the AAA configuration algorithm was carried out and data were compared against measurements. To better appraise the performance of AAA and the capability of its configuration to tailor machine-specific characteristics, data obtained from the pencil beam convolution (PBC) algorithm implemented in Eclipse were also added in the comparison. Since the purpose of the paper is to address the basic performances of the AAA and of its configuration procedures, only data relative ...
2006-03-21
Energy Technology Data Exchange (ETDEWEB)
A study of mine-waste contamination effects on Methow River habitat on the eastern slopes of the north Cascade Mountains in Washington state, U.S.A., revealed impacts at ecosystem, community, population, individual, tissue, and cellular levels. Ore deposits in the area were mined for gold, silver, copper and zinc until the early 1950's, but the mines are now inactive. An above-and-below-mine approach was used to compare potentially impacted to control sites. The concentrations of eleven trace elements (i.e., Al, As, B, Ba, Cd, Cr, Cu, Mn, Pb, Se, and Zn) in Methow River sediments downstream from the abandoned mine sites were higher than background levels. Exposed trout and caddisfly larvae in the Methow River showed reduced growth compared to controls. Samples of liver from juvenile trout and small intestine from exposed caddisfly larvae were examined for evidence of metal accumulation, cytopathological change, and chemical toxicity. ...
2003-05-15
Developmental cortical thinning in fetal alcohol spectrum disorders.
Regional cortical thickness was evaluated using CIVET processing of 3D T1-weighted images (i) to compare the variation in cortical thickness between 33 participants with fetal alcohol spectrum disorders (FASD) aged 6-30 years (mean age 12.3 years) versus 33 age/sex/hand-matched controls, and (ii) to examine developmental changes in cortical thickness with age from children to young adults in both groups. Significant cortical thinning was found in the participants with FASD in large areas of the bilateral middle frontal lobe, pre- and post- central areas, lateral and inferior temporal and occipital lobes compared to controls. No significant cortical thickness increases were observed for the FASD group. Cortical thinning with age in a linear model was observed in both groups, but the locations were different for each group. FASD participants showed thinning with age in the left middle frontal, bilateral ...
2011-06-17
The mixture of 1,3-dichloropropene (1,3-D) and chloropicrin (CP) is used as a preplant soil fumigant. In comparison with individual fumigants, application of a mixture may affect the environmental dissipation and fate of each chemical, such as emission and degradation. We investigated the degradation of CP, 1,3-D, and their mixture in fresh soils and sterile soils, and evaluated the competitive characteristic of fumigants in the mixture. The degradation of low concentrations of CP in fresh soil was accelerated at early times in the presence of 1,3-D, whereas the addition of CP reduced the degradation rate of trans-1,3-D, possibly by inhibiting the activity of trans-1,3-D degrading microorganisms. The potential of applying amendments to the soil to increase the rate of CP and 1,3-D degradation was also illustrated. The degradation of both fumigants was significantly enhanced in soils amended with ammonium thiosulfate (ATS) and sodium diethyldithiocarbamate (Na-DEDTC) ...
Correlation between electrochemical properties and corrosion resistance of zirconium alloys
International Nuclear Information System (INIS)
The electrochemical behavior of some zirconium alloys including Zry-2 with various #SIGMA#Ai from 2.5 x 10"-"2"0 to 1.2 x 10"-"1"7 (h), modified Zry-2 with iron contents of 0.15, 0.25, and 0.5%, and standard Zry-4 was studied by measuring anodic polarization curves in sulfuric acid solution. The results of these electrochemical tests were compared with those of steam autoclave tests. In Zry-2, the current peak was observed at 1250 mV (versus SCE) on the anodic polarization curve, and this peak area increased with #SIGMA#Ai and with the size of secondary precipitates. Also, this peak was closely correlated with nodular corrosion resistance as expected from the above results. As iron contents in modified Zry-2 increased, the current peak at 1,250 mV decreased and a new peak at 1,900 mV appeared. The former peak disappeared and the latter peak increased further at 0.5% iron. In Zry-4, the current peak was observed at 1,900 mV, ...
1995-09-11
Energy Technology Data Exchange (ETDEWEB)
Two window layer materials, Al{sub 0.51}In{sub 0.49}P (E{sub g} = 2.3 eV) and Ga{sub 0.51}In{sub 0.49}P (E{sub g} = 1.88 eV) were compared for gas-source and solid-source MBE grown GaAs and Ga{sub 0.84}In{sub 0.16}As{sub 0.68}P{sub 0.32} (E{sub g} = 1.55 eV) solar cells. Due to the wider band-gap of Al{sub 0.51}In{sub 0.49}P, the increased spectral response was observed for both GaAs and Ga{sub 0.84}In{sub 0.16}As{sub 0.68}P{sub 0.32} material based solar cells. In the case of the GaAs cells, the short-circuit current density was observed to increase from 32.5 mA/cm{sup 2} to 34.4 mA/cm{sup 2} with the Al{sub 0.51}In{sub 0.49}P window layer at AM0. Similar improvement was observed for the Ga{sub 0.84}In{sub 0.16}As{sub 0.68}P{sub 0.32} solar cells.
1997-12-31
International Nuclear Information System (INIS)
Aqueous deoxyhemoglobin solutions (2 mg/ml) were gamma-irradiated by a "6"0Co source in the presence of methanol, ethanol, 1-butanol and t-butanol under N_2O or argon. The effects of the interaction of the particular alcohol radical species with hemoglobin were determined according to the detected spectral alterations in the visible range. The amounts of stable final products in the form of methemoglobin (MetHb) and the sum of hemichromes and cholehemichromes (Hemichr) were estimated in irradiated preparations. For preparations irradiated under N_2O, the radiation yield for MetHb formation was three-fold lower in the presence of ethanol and 1-butanol [G(MetHb) = 0.33[ compared with preparations irradiated in the presence of t-butanol or without alcohol [G(MetHb) = 1.00[. The yield of hemichromes and cholehemichromes in preparations irradiated under N_2O increased in the order: ethanol (G = 0.38), 1-butanol (B = 0.52), t-butanol (G = 0.59), and in the absence of ...
Saddle field fast atom beam source: A new low pressure plasma nitriding method for a alloy Ti-6Al-4V
Energy Technology Data Exchange (ETDEWEB)
Ti and its alloys (Ti-6Al-4V) have been used in different engineering applications due to their several outstanding properties. Nevertheless, their use in practical applications is limited in many cases due to their poor tribological property. Researches are ongoing on surface modification of Ti based materials by different plasma and ion based techniques to overcome this problem. However, the conventional plasma nitriding techniques have several problems such as formation of an arc, increased possibility of surface contamination due to a comparatively higher operating pressure, production of a very thin nitrided layer after a long processing time, etc. In this present work, the possibility of a new low-pressure plasma nitriding process using a Plasma Enhanced Chemical Vapor Deposition (PECVD) based saddle field fast atom beam source on a Ti-6Al-4V alloy sample is investigated. Plasma nitriding was carried out at 900 deg. C and at a pressure 0.1 Pa for 8 h by using ...
2006-09-25
Saddle field fast atom beam source: A new low pressure plasma nitriding method for a alloy Ti-6Al-4V
International Nuclear Information System (INIS)
Ti and its alloys (Ti-6Al-4V) have been used in different engineering applications due to their several outstanding properties. Nevertheless, their use in practical applications is limited in many cases due to their poor tribological property. Researches are ongoing on surface modification of Ti based materials by different plasma and ion based techniques to overcome this problem. However, the conventional plasma nitriding techniques have several problems such as formation of an arc, increased possibility of surface contamination due to a comparatively higher operating pressure, production of a very thin nitrided layer after a long processing time, etc. In this present work, the possibility of a new low-pressure plasma nitriding process using a Plasma Enhanced Chemical Vapor Deposition (PECVD) based saddle field fast atom beam source on a Ti-6Al-4V alloy sample is investigated. Plasma nitriding was carried out at 900 deg. C and at a pressure 0.1 Pa for 8 h by using ...
2006-09-25
Energy Technology Data Exchange (ETDEWEB)
Microorganisms associated with fractured basalt core were compared to those suspended in groundwater pumped from the same well in the eastern Snake River Plain Aquifer (Idaho, USA). Two wells influenced to different degrees by a mixed-waste plume in the fractured basalt aquifer were examined. In one well, an array of dialysis cells filled with either deionized water or crushed basalt was equilibrated to compare the microorganisms collected in this fashion with those from core and groundwater samples collected in a traditional manner from the same well. Analyses were performed to characterize these samples and to provide a basis for comparison. These included total cell counts by microscopy; total biomass by phospholipid fatty acid analysis; enumerations of viable aerobic heterotrophs, groups of putative aerobic co-metabolic TCE-degraders and aerobic H2-oxidizing bacteria; mineralization of 14C- labeled acetate; and enrichments for dissimilatory ...
2004-04-01
Ionizing radiation-induced mutation of human cells with different DNA repair capacities
Energy Technology Data Exchange (ETDEWEB)
We have observed significant differences in the response to ionizing radiation of two closely related human cell lines, and now compare the effects on these lines of both low and intermediate LET radiation. Compared to TK6, WTK1 has an enhanced X-ray survival, and is also more resistant to cell killing by {alpha}-particles. The hprt locus is more mutable in WTK1 than in TK6 by both X-rays and {alpha}-particles. WTK1 is also more mutable by {alpha}-particles than by X-rays at the hprt locus. X-ray-induced mutation at the heterozygous tk locus in WTK1 is about 25 fold higher than in TK6, while {alpha}-particle-induced mutation is nearly 50 fold higher at this locus. Also, the slowly growing tk- mutants, which comprise the majority of spontaneous and X-ray-induced tk- mutants of TK6, were not induced significantly by {alpha}-particles. Previously, we showed that TK6 has a reduced capacity for recombination ...
1994-12-31
Electronic and geometric structure of transition-metal nanoclusters
Energy Technology Data Exchange (ETDEWEB)
A massively-parallel ab initio computer code, which uses Gaussian bases, pseudopotentials, and the local density approximation, permits the study of transition-metal systems with literally hundreds of atoms. We present total energies and relaxed geometries for Ru, Pd, and Ag clusters with N = 55, 135, and 140 atoms; we also used the DMOL code to study 13-atom Pd and Cu clusters, with and without hydrogen. The N = 55 and 135 clusters were chosen because of simultaneous cubo-octahedral (fcc) and icosahedral (icos) sub-shell closings, and we find icos geometries are preferred. Remarkably large compressions of the central atoms are observed for the icos structures (up to 6% compared with bulk interatomic spacings), while small core compressions ({approx} 1 %) are found for the fcc geometry. In contrast, large surface compressive relaxations are found for the fcc clusters ({approx} 2-3% in average nearest neighbor spacing), while the icos surface ...
1996-08-01
International Nuclear Information System (INIS)
Male rats were injected intravenously for 15 min with physiological saline (as control) (0.05 #mu#g/kg/min) or norepinephrine (NE) (0.1 #mu#g/kg/min) followed by 740 kBq of MIBG. Rats were injected for more 30 min (early stage group) and for more 4 hr (late stage group) with physiological saline or NE. Five MBq of "9"9"mTc-tetrofosmin (TF) was administered instead of MIBG in another group. The heart was isolated and uptake of MIBG or TF of right ventricle, apex, and left ventricle (divided into 8 parts) was measured. In control group, MIBG uptake of apex was significantly lower than that of lateral wall in both early and late groups. In NE group, MIBG uptake showed a tendency to decrease in both early and late groups. Compared with control group, the uptake of anterior wall in late group decreased significantly at NE 0.1 #mu#/kg/min. The TF uptake in control group was not different in each part. In NE group, the TF uptake of right ventricle decreased significantly ...
1998-06-01
International Nuclear Information System (INIS)
The purpose of this work was to study and quantify the differences in dose distributions computed with some of the newest dose calculation algorithms available in commercial planning systems. The study was done for clinical cases originally calculated with pencil beam convolution (PBC) where large density inhomogeneities were present. Three other dose algorithms were used: a pencil beam like algorithm, the anisotropic analytic algorithm (AAA), a convolution superposition algorithm, collapsed cone convolution (CCC), and a Monte Carlo program, voxel Monte Carlo (VMC++). The dose calculation algorithms were compared under static field irradiations at 6 MV and 15 MV using multileaf collimators and hard wedges where necessary. Five clinical cases were studied: three lung and two breast cases. We found that, in terms of accuracy, the CCC algorithm performed better overall than AAA compared to VMC++, but AAA remains an attractive option for routine ...
2007-07-07
International Nuclear Information System (INIS)
The purpose of this work was to study and quantify the differences in dose distributions computed with some of the newest dose calculation algorithms available in commercial planning systems. The study was done for clinical cases where large density inhomogeneities were present. Three dose algorithms were used: a pencil beam like algorithm, the anisotropic analytic algorithm (AAA), a convolution superposition algorithm, collapsed cone convolution (CCC) and a Monte Carlo program, voxel Monte Carlo (VMC++). The dose calculation algorithms were compared under static field irradiations at 6 MV and 15 MV using multileaf collimators and hard wedges where necessary. Five clinical cases were studied: three lung and two breast cases. We found that the CCC algorithm performed overall better than AAA compared to VMC++, but AAA remains an attractive option for routine use in the clinic due to its short computation times. Dose differences between the ...
2007-06-01
DISSIPATION AND EXTRA LIGHT IN GALACTIC NUCLEI. III. 'CORE' ELLIPTICALS AND 'MISSING' LIGHT
International Nuclear Information System (INIS)
We investigate how 'extra' or 'excess' central light in the surface brightness profiles of cusp or power-law elliptical galaxies relates to the profiles of ellipticals with cores. The envelopes of cusp ellipticals are established by violent relaxation in mergers acting on stars present in gas-rich progenitor disks, while their centers are structured by the relics of dissipational, compact starbursts. Ellipticals with cores are formed by the subsequent merging of the now gas-poor cusp ellipticals, with the fossil starburst components combining to preserve a dense, compact component in these galaxies as well (although mixing of stars smooths the transition from the outer to inner components in the profiles). By comparing extensive hydrodynamical simulations to observed profiles spanning a broad mass range, we show how to observationally isolate and characterize the relic starburst component in core ellipticals. Our method ...
2009-04-01
Adaptive Waveform Correlation Detectors for Arrays: Algorithms for Autonomous Calibration
Energy Technology Data Exchange (ETDEWEB)
Waveform correlation detectors compare a signal template with successive windows of a continuous data stream and report a detection when the correlation coefficient, or some comparable detection statistic, exceeds a specified threshold. Since correlation detectors exploit the fine structure of the full waveform, they are exquisitely sensitive when compared to power (STA/LTA) detectors. The drawback of correlation detectors is that they require complete knowledge of the signal to be detected, which limits such methods to instances of seismicity in which a very similar signal has already been observed by every station used. Such instances include earthquake swarms, aftershock sequences, repeating industrial seismicity, and many other forms of controlled explosions. The reduction in the detection threshold is even greater when the techniques are applied to arrays since stacking can be performed on the ...
2009-07-23
Evolution of improved varieties of sesame through induced mutations
International Nuclear Information System (INIS)
Sesame varieties/genotypes showed a good response to radiation with gamma rays and treatments with EMS. In M_1 both gamma rays and EMS influenced germination, seedling height, survival of plants and pollen fertility/sterility, producing deleterious effects on these characters. Compared to black seeded genotypes, white seeded ones are more susceptible to radiation. Both gamma rays and EMS produced various types of morphological variations in M_2 generation. These were dwarf plant mutants, mottled and fleshy leaved mutants (sterile), fasciated stem, flower colour, altered phyllotaxy, early, uniculm, capsule size variations, multiple capsule/leaf axil, seed coat colour variations, indehiscent and semi-indehiscent type mutants. Moreover, studies on quantitative characters including seed yield revealed the induction of mutants in both positive and negative directions for such traits which made a good scope of selection of desirable mutants in M_2 generation. Mutants ...
2001-01-01
Energy Technology Data Exchange (ETDEWEB)
Proton and alpha particle spectral shapes and multiplicities have been measured in coincidence with evaporation residues from {sup 28}Si+{sup 165}Ho and {sup 16}O + {sup 197}Au, {sup 208}Pb fusion reactions. Our experiments used 145 to 220 MeV {sup 28}Si and 115 and 140 MeV {sup 16}O beams produced with the Stony Brook LINAC. ER`s were separated using an electrostatic deflector and detected with large area surface barrier detectors. Light charged particles were detected at forward and backward angles with fourteen single NaI detectors. In the context of the statistical model, charged particle spectra yield information about emission barriers and compound nucleus equilibrium level densities. These are significant ingredients in calculations determining fission timescales from other observables such as pre-scission neutron multiplicities or fusion-evaporation excitation functions. Results will also be compared to analyses of pre-scission charged ...
1993-10-01
cDNA Cloning and mRNA analysis of PGC-1 in epitrochlearis muscle in swimming-exercised rats.
Peroxisome proliferator-activated receptor gamma coactivator-1 (PGC-1), a cold-inducible coactivator of nuclear receptors, stimulates mitochondrial biogenesis and respiration in muscle cells. In the present study, we first cloned a rat PGC-1 gene from a brown adipose tissue cDNA library which encodes a predicted 796-amino-acid protein and exhibits respectively 98% and 95% identity with the mouse and human homologues. Next, we examined the effect of swimming exercise training on the level of expression of the PGC-1 gene in rat epitrochlearis (Epi) muscle. PGC-1 mRNA level in Epi muscle in rats that swam 2 h a day for 3 and 7 days increased dramatically by 154% and 163%, respectively, compared to the non-exercised control group. PGC-1 mRNA up-regulation was not observed in an immersion group treated at 35 degrees C during the training program but without swimming exercise. These results demonstrate that expression of the PGC-1 gene in Epi muscle ...
2000-08-01
British Library Electronic Table of Contents (United Kingdom)
Abstract Salmonella Typhimurium and Listeria monocytogenes are major bacterial pathogens associated with poultry products. A controlled released ClO2 sachet applied with modified atmosphere packaging (MAP) was evaluated for its ability to control the growth of S. Typhimurium and L. monocytogenes on raw chicken breast during refrigerated storage. The fresh chicken samples were inoculated with one or the other of the pathogens at 104-cfu/g, and the packages (with and without ClO2 sachet) were flushed with ambient air or 30% CO2/70% N2 before sealing, and then stored at 4C for up to 21 days. The maximum reduction in MAP plus ClO2 (compared with MAP alone) was 0.68-log-cfu/g for S. Typhimurium and 1.87-log-cfu/g for L. monocytogenes. Color and pH changes of the chicken breast were observed at ...
2011-01-01
Tritium Release Behavior from Li_4SiO_4
International Nuclear Information System (INIS)
This paper proposes a model to explain tritium release behavior of an irradiated Li_4SiO_4 sample made by Forschungszentrum Karlsruhe. The release curves were obtained in a series of experiments carried out using out-pile temperature programmed desorption techniques in the Kyoto University Reactor (KUR). Tritium release curves obtained for different purge gas compositions (N_2, N_2 + H_2, N_2 + H_2O) were compared for selection of suitable conditions to determine the apparent diffusivity of tritium in a crystal grain of Li_4SiO_4.In the model formation, some mass transfer steps in the bulk of the crystal grain and those on the surface of the grain were taken into account, which were diffusion of tritium in the grain, adsorption and desorption of water on the surface of the grain, two types of isotope exchange reactions, and water formation reaction by the addition of hydrogen to the purge gas.Diffusivities of tritium in the crystal grain of Li_4SiO_4 were estimated ...
2004-12-01
Transient enhanced diffusion of Sb and B due to MeV silicon implants
Energy Technology Data Exchange (ETDEWEB)
We measure the transient enhanced diffusion of shallow molecular-beam-epitaxy grown marker layers of Sb and B due to deep MeV Si{sup +} ion implants at very high doses ({approx}10{sup 16}cm{sup {minus}2}). We expect the near-surface region of these implants to be vacancy rich, and we observe transient enhanced diffusion of Sb (the classic vacancy diffuser). The large enhancements imply a significant vacancy supersaturation ({approx}700 at 740{degree}C). Double implantation of the high-dose MeV Si followed by a shallow (40 keV) Si implant and annealing produces a greatly reduced number of {l_brace}311{r_brace} defects compared to a 40 keV implant into virgin Si, again consistent with a vacancy-rich region in the near-surface region of an MeV implant. However, the shallow B marker layers also show transient enhanced diffusion for the same MeV implant under similar annealing conditions, implying that an interstitial supersaturation is present at ...
1997-06-01
Transient enhanced diffusion of Sb and B due to MeV silicon implants
International Nuclear Information System (INIS)
We measure the transient enhanced diffusion of shallow molecular-beam-epitaxy grown marker layers of Sb and B due to deep MeV Si"+ ion implants at very high doses (#approx#10"1"6cm"-"2). We expect the near-surface region of these implants to be vacancy rich, and we observe transient enhanced diffusion of Sb (the classic vacancy diffuser). The large enhancements imply a significant vacancy supersaturation (#approx#700 at 740 degree C). Double implantation of the high-dose MeV Si followed by a shallow (40 keV) Si implant and annealing produces a greatly reduced number of #left brace#311#right brace# defects compared to a 40 keV implant into virgin Si, again consistent with a vacancy-rich region in the near-surface region of an MeV implant. However, the shallow B marker layers also show transient enhanced diffusion for the same MeV implant under similar annealing conditions, implying that an interstitial supersaturation is present at the same ...
Energy Technology Data Exchange (ETDEWEB)
High concentrations of toxic chemicals in sediment and white croaker (Genyonemus lineatus), as well as liver diseases (e.g., carcinomas) in this species, were found in the Los Angeles area. The highest concentrations of aromatic hydrocarbons (AHs) in the sediment were in San Pedro Bay, and the highest concentrations of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) derivatives were in sediment from near the White Point sewer outfall. Concentrations of AHs, polychlorobiphenyls (PCBs), and DDT derivatives were generally higher in food organisms from the croaker's stomach than in sediment. Moreover, croaker from San Pedro Bay and White Point were substantially contaminated with DDT derivatives and metabolites of aromatic compounds, compared to croaker from the Hyperion outfall and Dana Point. The evidence suggest that the observed pathological conditions of the liver were associated with exposure of the croaker to toxic chemicals, ...
1987-08-01
International Nuclear Information System (INIS)
The thermodynamics of the Sr-Si system is of fundamental importance for the understanding of eutectic modification of Al-Si alloys. At the same time, strontium silicides have recently been found to have potential applications in electronic devices. Renewed research efforts have led to a re-evaluation of the phase equilibria in this system, resulting in the discovery of previously undetected stable intermetallic compounds. In this work, we investigate the finite temperature thermodynamic properties of the stable (and metastable) Sr-Si intermetallics. The vibrational properties of the intermetallic compounds are calculated within harmonic theory, with quasi-harmonic corrections to account for the effects of thermal expansion. The total free energies of the compounds are computed considering vibrational and electronic contributions, as well as weak anharmonic corrections. The ground state of the system is predicted and compared to previous experimental and ...
2009-09-18
Thermal energy storage system using stearic acid as a phase change material
Energy Technology Data Exchange (ETDEWEB)
The thermal performance and phase change stability of stearic acid as a latent heat energy storage material has been studied experimentally. The thermal performance and heat transfer characteristics of the stearic acid were tested and compared with other studies given in the literature. In the present study, parameters such as transition times, temperature range and propagation of the solid-liquid interface as well as the effect of heat flow rate on the phase change stability of stearic acid as a phase change material (PCM) were studied. The experimental results showed that the melting stability of the PCM is better in the radial direction than in the axial direction. The variation in the melting and solidification parameters of the PCM with the change of inlet water temperature is also studied. We observed that while the heat exchanger tube is in the horizontal position, the PCM has more effective and steady phase change characteristics than ...
2001-07-01
Energy Technology Data Exchange (ETDEWEB)
This work presents a comparative study of low-alloy steel nitriding for different possible techniques. Active screen plasma nitriding (ASPN) is a successful surface modification method that has many advantages over the conventional DC plasma nitriding (CPN). The corrosion behavior of 30CrNiMo8 low-alloy steel has been examined using anodic polarization tests in 3.5% NaCl solution under varying conditions of ASPN and CPN processes. The process variables included active screen setup parameters, treatment temperature (550 and 580 deg. C), gas mixture (25/75 and 75/25 of N{sub 2}/H{sub 2}) and treatment time (5 and 10 h) in 500 Pa pressure. The structure and phases composition of the compound layer was studied by X-ray diffraction (XRD), microhardness tests, optical microscopy and scanning electron microscopy (SEM). It was observed that ASPN treated samples surface enhanced corrosion resistance while the temperature and/or hole size of screen setup ...
2009-09-18
International Nuclear Information System (INIS)
This work presents a comparative study of low-alloy steel nitriding for different possible techniques. Active screen plasma nitriding (ASPN) is a successful surface modification method that has many advantages over the conventional DC plasma nitriding (CPN). The corrosion behavior of 30CrNiMo8 low-alloy steel has been examined using anodic polarization tests in 3.5% NaCl solution under varying conditions of ASPN and CPN processes. The process variables included active screen setup parameters, treatment temperature (550 and 580 deg. C), gas mixture (25/75 and 75/25 of N_2/H_2) and treatment time (5 and 10 h) in 500 Pa pressure. The structure and phases composition of the compound layer was studied by X-ray diffraction (XRD), microhardness tests, optical microscopy and scanning electron microscopy (SEM). It was observed that ASPN treated samples surface enhanced corrosion resistance while the temperature and/or hole size of screen setup ...
2009-09-18
The in-reactor deformation of the PCA alloy
Energy Technology Data Exchange (ETDEWEB)
The swelling and in-reactor creep behaviors of the PCA alloy have been determined from the irradiation of pressurized tube specimens in the FFTF reactor. These data have been obtained to a peak neutron fluence corresponding to approximately 80 dpa in the FFTF reactor for irradiation temperatures between 400 and 750/sup 0/C. Diametral measurements performed on the unstressed specimens indicate the possible onset of swelling in the PCA alloy for irradiation temperatures between 400 and 550/sup 0/C and at a neutron fluence corresponding to approx.50 dpa. The creep data suggest a non-linear fluence dependence and linear stress dependence (for hoop stresses less than 100 MPa) which is consistent with the in-reactor creep behavior of many cold worked austenitic stainless steels. These PCA creep data are compared to available 316 SS in-reactor creep data. The in-reactor creep strains for PCA are significantly less than observed in 20% cold worked 316 ...
1986-04-01
The in-reactor deformation of the PCA alloy
International Nuclear Information System (INIS)
The swelling and in-reactor creep behaviors of the PCA alloy have been determined from the irradiation of pressurized tube specimens in the FFTF reactor. These data have been obtained to a peak neutron fluence corresponding to approximately 80 dpa in the FFTF reactor for irradiation temperatures between 400 and 750"0C. Diametral measurements performed on the unstressed specimens indicate the possible onset of swelling in the PCA alloy for irradiation temperatures between 400 and 550"0C and at a neutron fluence corresponding to #approx#50 dpa. The creep data suggest a non-linear fluence dependence and linear stress dependence (for hoop stresses less than 100 MPa) which is consistent with the in-reactor creep behavior of many cold worked austenitic stainless steels. These PCA creep data are compared to available 316 SS in-reactor creep data. The in-reactor creep strains for PCA are significantly less than observed in 20% cold worked 316 SS over ...
1986-04-13
Swift panchromatic observations of the bright gamma-ray burst GRB050525a
The bright gamma-ray burst GRB050525a has been detected with the Swift observatory, providing unique multiwavelength coverage from the very earliest phases of the burst. The X-ray and optical/UV afterglow decay light curves both exhibit a steeper slope ~0.15 days after the burst, indicative of a jet break. The timing of the jet break combined with the total gamma-ray energy of the burst constrains the opening angle of the jet to be 2.5 degrees. We derive an empirical `time-lag' redshift from the BAT data of z_hat = 0.69 +/- 0.02, in good agreement with the spectroscopic redshift of 0.61. Prior to the jet break, the X-ray data can be modelled by a simple power law with index alpha = -1.2. However after 300s the X-ray flux brightens by about 30% compared to the power-law fit. The optical/UV data have a more complex decay, with evidence of a rapidly falling reverse shock component that dominates in the first minute or so, giving way to a flatter forward shock ...
2006-01-01
British Library Electronic Table of Contents (United Kingdom)
Several thin film composite nanofiltration membranes have been prepared by spin coating a sulfonated poly(ether ether ketone) solution on a polyethersulfone support, followed by thermal treatment. The most optimal developed nanofiltration membrane shows a clean water permeance of ~4.5Lm^-^2h^-^1bar^-^1 and a molecular weight cut off (MWCO) of ~500gmol^-^1. No irreversible changes in membrane performance have been observed after prolonged exposure (up to several weeks) of this membrane to solutions with a pH in the range 0-14. Compared to Desal-5-DK, the developed membrane displays a similar water permeance and a higher NaCl retention. In comparison to commercially available pH stable membranes, MPF-34 and NP030P, it reveals a higher water permeance. Permeance and MWCO analysis at varying p...
2011-01-01
Subcellular distribution of ryanodine receptors in the cardiac muscle of carp (Cyprinus carpio).
We examined the subcellular localization of ryanodine receptors (RyR) in the cardiac muscle of carp using biochemical, immunohistochemical, and electron microscopic methods and compared it with those of rats and guinea pigs. To achieve this goal, an anti-RyR antibody was newly raised against a synthetic peptide corresponding to an amino acid sequence that was conserved among all sequenced RyRs. Western blot analysis using this antibody detected a single RyR band following the SDS-PAGE of sarcoplasmic reticulum (SR) membranes from carp atrium and ventricle as well as from mammalian hearts and skeletal muscles. The carp heart band had slightly greater mobility than those of mammalian hearts. Although immunohistochemical staining showed evident striations corresponding to the Z lines in longitudinal sections of mammalian hearts, clusters of punctate staining, in contrast, were distributed ubiquitously throughout carp atrium and ventricle. Electron microscopic images ...
2003-06-12
International Nuclear Information System (INIS)
Structural and functional responses of a benthic macroinvertebrate assemblage to pulses of the insecticide imidacloprid were assessed in outdoor stream mesocosms. Imidacloprid pulses reduced invertebrate abundance and community diversity in imidacloprid-dosed streams compared to control streams. These results correlated well with effects of imidacloprid on leaf litter decomposition and feeding rates of Pteronarcys comstocki, a stonefly, in artificial streams. Reductions in oxygen consumption of stoneflies exposed to imidacloprid were also observed in laboratory experiments. Our findings suggest that leaf litter degradation and single species responses can be sensitive ecotoxicological endpoints that can be used as early warning indicators and biomonitoring tools for pesticide contamination. The data generated illustrates the value of mesocosm experiments in environmental assessment and how the consideration of functional and structural ...
Strength functions of primary transitions following thermal neutron capture in strontium
Energy Technology Data Exchange (ETDEWEB)
The primary E1, M1 and E2 ..gamma..-radiation in /sup 87,88,89/Sr observed after thermal neutron capture was compared with the predictions of single particle and giant resonance models. The nuclei feature a wide range of neutron binding energies between 6.3 and 11.1 MeV, which makes a 5.5 MeV spectrum of primary transition energies available for investigation. The (n, ..gamma..) reaction was used to estimate the parameters of the spin-flip M1 giant resonance in strontium. The total energy weighted M1 strength of this resonance exceeds the results of shell model and random phase approximation calculations for /sup 90/Zr by a factor of 3-4. The E1 strengths were found to agree with the established giant dipole resonance model. The few data on primary E2 transitions do not allow to differentiate between the giant quadrupole resonance and the single particle models.
1989-04-01
Strength functions of primary transitions following thermal neutron capture in strontium
International Nuclear Information System (INIS)
The primary E1, M1 and E2 #gamma#-radiation in "8"7","8"8","8"9Sr observed after thermal neutron capture was compared with the predictions of single particle and giant resonance models. The nuclei feature a wide range of neutron binding energies between 6.3 and 11.1 MeV, which makes a 5.5 MeV spectrum of primary transition energies available for investigation. The (n, #gamma#) reaction was used to estimate the parameters of the spin-flip M1 giant resonance in strontium. The total energy weighted M1 strength of this resonance exceeds the results of shell model and random phase approximation calculations for "9"0Zr by a factor of 3-4. The E1 strengths were found to agree with the established giant dipole resonance model. The few data on primary E2 transitions do not allow to differentiate between the giant quadrupole resonance and the single particle models. (orig.).
Stereotactic body radiotherapy for unresectable cholangiocarcinoma
International Nuclear Information System (INIS)
Purpose: To report outcomes of a single institution study of stereotactic body radiotherapy (SBRT) for unresectable cholangiocarcinoma. The dose-volume dependency of the observed gastrointestinal toxicity is explored. Methods and materials: Twenty-seven patients with unresectable cholangiocarcinoma (n = 26 Klatskin tumours and one intrahepatic cholangiocarcinoma (IHCC)) were treated by linac-based SBRT. The dose schedule was 45 Gy in three fractions prescribed to the isocenter. Results: The median progression-free survival and overall survival were 6.7 and 10.6 months, respectively. With a median follow-up of 5.4 years, 6 patients had severe duodenal/pyloric ulceration and 3 patients developed duodenal stenosis. Duodenal radiation exposure was higher in patients developing moderate to high-grade gastrointestinal toxicity with the difference in mean maximum dose to 1 cm"3 of duodenum reaching statistical significance. A statistically significant association between ...
2010-01-01
Some observations on the flow of financial resources to developing countries
Energy Technology Data Exchange (ETDEWEB)
This paper highlights some of the conceptual and methodological problems involved in the compilation of statistics on economic aid to developing countries. Figures from the OECD Development Assistance Committee (DAC) and the Organization of Petroleum Exporting Countries (OPEC) member states are compared to point up problems in the interpretation of the statistics. One area of concern is the listing of funds provided by financial institutions located in the DAC countries. OPEC capital often forms a majority of such institutions; yet the figures do not measure the OPEC share of the capital nor its share of the risk borne in its provision of the loans. Another area of concern is bond purchases and subscriptions to syndicated loans by OPEC financial institutions in the financial markets of DAC countries. The flows in these instances, originating from OPEC sources, are merely channeled through the DAC financial markets. Based on origin and risk (borne exclusively by ...
1980-03-01
We analytically work out the orbital effects caused by a Rindlertype extra-acceleration ARin which naturally arises in some recent models of modified gravity at large distances. In particular, we focus on the perturbations induced by it on the two-body range {\\rho} and range-rate {\\rho}\\cdot which are commonly used in satellite and planetary investigations as primary observable quantities. The constraints obtained for ARin by comparing our calculations with the currently available range and range-rate residuals for some of the major bodies of the solar system, obtained without explicitly modeling ARin, are 1 - 2 \\times 10-13 m s-2 (Mercury and Venus), 1 \\times 10-14 m s-2 (Saturn), 1 \\times 10-15 m s-2 (Mars), while for a terrestrial Rindler acceleration we have 5 \\times 10-16 m s-2 (Moon). Another approach which could be followed consists of taking into account ARin in re-processing all the available data sets with accordingly modified ...
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
Bisaminoethanethiol (BAT) ligands with various gem-dimethyl and amide groups were prepared, and the corresponding neutral Tc-99m complexes were prepared and evaluated for their relative stabilities by ligand-exchange reactions. It was demonstrated that technetium complexes containing gem-dimethyl substituents have higher lipophilicities, whereas those with an amide group possess greater stability, which enhances ligand-exchange reaction. The most interesting observation was that the brain uptake in rats is not determined only by lipophilicity. Apparently, Tc-99m complexes with an amide functional group display lower brain uptakes in rats compared to those without an amide group. The brain uptake was strongly influenced by substituents on the BAT ligand. These factors are critically important and should be taken into consideration when designing Tc-99m-labeled agents for CNS receptor imaging.
1998-02-01
Site-selective spectroscopy of Er{sup 3+} ions in the Bi{sub 12}SiO{sub 20} piezoelectric crystal
Energy Technology Data Exchange (ETDEWEB)
Site-selective spectroscopy fluorescence experiments (emission and excitation) in the near-infrared region associated with the {sup 4}I{sub 15/24}I{sub 11/2} transitions of Er{sup 3+} ions have been successfully used to show the presence of two different Er{sup 3+} centres in the Bi{sub 12}SiO{sub 20} piezoelectric crystal. Green (545-570 nm), red (650-690 nm) and near-infrared (850-890 nm) up-converted emissions have been observed and resolved for each type of centre under excitation up to the {sup 4}{sub I11/2} state. The Stark energy level schemes of the three lower energy states of Er{sup 3+} ions have been determined and compared for both centres, showing two quite different crystalline field environments. The mechanisms responsible for the up-conversion process (excited state absorption and/or energy transfer up-conversion) are also analysed. (author)
2001-12-03
Site-selective spectroscopy of Er"3"+ ions in the Bi_1_2SiO_2_0 piezoelectric crystal
International Nuclear Information System (INIS)
Site-selective spectroscopy fluorescence experiments (emission and excitation) in the near-infrared region associated with the "4I_1_5_/_2_4I_1_1_/_2 transitions of Er"3"+ ions have been successfully used to show the presence of two different Er"3"+ centres in the Bi_1_2SiO_2_0 piezoelectric crystal. Green (545-570 nm), red (650-690 nm) and near-infrared (850-890 nm) up-converted emissions have been observed and resolved for each type of centre under excitation up to the "4_I_1_1_/_2 state. The Stark energy level schemes of the three lower energy states of Er"3"+ ions have been determined and compared for both centres, showing two quite different crystalline field environments. The mechanisms responsible for the up-conversion process (excited state absorption and/or energy transfer up-conversion) are also analysed. (author)
2001-12-03
Signal Processing in Large Systems: a New Paradigm
For a long time, signal processing applications, and most particularly detection and parameter estimation methods, have relied on the limiting behaviour of test statistics and estimators, as the number n of observations of a population grows large comparatively to the population size N, i.e. n>>N. Modern technological and societal advances now demand the study of sometimes extremely large populations, while simultaneously requiring fast signal processing due to accelerated system dynamics; this results in not-so-large practical ratios n/N, sometimes even smaller than one. A disruptive change in classical signal processing methods has therefore been initiated in the past ten years, mostly spurred by the field of large dimensional random matrix theory. The early literature in random matrix theory for signal processing applications is however scarce and highly technical. This tutorial proposes an accessible methodological introduction to the ...
2011-01-01
Shell-model predictions for electromagnetic properties of N = 50 nuclei
Energy Technology Data Exchange (ETDEWEB)
Predictions for E2, M1, and M4 transition rates and moments, together with examples of transition-charge densities, are presented for states of N = 50 nuclei. These predictions are based on one-body spectroscopic amplitudes obtained from the wave functions of a new N = 50 shell-model calculation which incorporates the 0f/sub 5/2/, 1p/sub 3/2/, 1p/sub 1/2/, and 0g/sub 9/2/ single-particle orbits and an empirically determined effective Hamiltonian for this space. The predictions are compared with experimental data, first in order to evaluate how well the model space, as applied by this Hamiltonian, accounts for observations, and then to assess the importance of configurations excluded from the model space and to determine the values of the operator renormalizations (effective charges and effective g factors) which optimally map the theoretical results onto the corresponding experimental values.
1988-12-01
Energy Technology Data Exchange (ETDEWEB)
The authors present a search for excited and exotic muon states {mu}*, conducted using an integrated luminosity of 371 pb{sup -1} of data collected in p{bar p} collisions at {radical}s = 1.96 TeV at the Tevatron with the CDF II detector. They search for associated production of {mu}{mu}* followed by the decay {mu}* {yields} {mu}{gamma}, resulting in the {mu}{mu}{gamma} final state. They compare the data to model predictions as a function of the mass of the excited muon M{sub {mu}*}, the compositeness energy scale {Lambda}, and the gauge coupling factor f. No signal above the standard model expectation is observed in the {mu}{gamma} mass spectrum. In the contact interaction model, they exclude 107 < M{sub {mu}*} < 853 GeV/c{sup 2} for {Lambda} = M{sub {mu}*}; in the gauge-mediated model, they exclude 100 < M{sub {mu}*} < 410 GeV/c{sup 2} for f/{Lambda} = 10{sup -2} GeV{sup -1}. These 95% confidence level exclusions ...
2006-06-01
Energy Technology Data Exchange (ETDEWEB)
In 10 cases of femoral neck fracture treated with prosthetic replacement, the preoperative sup(99m)Tc-MDP scintigraphs were investigated and then compared with each histological findings of the extracted femoral head. The appearances of the scintigraphs were classified into following 3 patterns; increased activity pattern of sup(99m)Tc-MDP uptake in the overall femoral head (type I) in 4 cases, deficient activity pattern at the lateral side correspond to weight-bearing area (type II) in 2 cases and considerably deficient activity pattern in the whole femoral head (type III) in remaining 4 cases. Histological examination of the extracted femoral heads revealed the narrow part of ischemic necrosis in type I. However type II showed extensive necrosis in the portion of deficient activity by scintigraphs and in type III, the femoral heads except articular cartilage were entirely necrotic. This classification of sup(99m)Tc-MDP scintigraphy is correlated with the degree ...
1984-06-01
Scintigraphical observation of femoral head in femoral neck fractures
International Nuclear Information System (INIS)
In IO cases of femoral neck fracture treated with prosthetic replacement, the preopera tive sup(99m)Tc-MDP scintigraphs were investigated and then compared with each histological findings of the extracted femoral head. The appearances of the scintigraphs were classified into following 3 patterns; increased activity pattern of sup(99m)Tc-MDP uptake in the overall femoral head (type I) in 4 cases, deficient activity pattern at the lateral side correspond to weight-bearing area (type II) in 2 cases and considerably deficient activity pattern in the whole femoral head (type III) in remaining 4 cases. Histological examination of the extracted femoral heads revealed the narrow part of ischemic necrosis in type I. However type II showed extensive necrosis in the portion of deficient activity by scintigraphs and in type III, the femoral heads except articular cartilage were entirely necrotic. This classification of sup(99m)Tc-MDP scintigraphy is correlated with the degree ...
Regulation of starch synthesis in potato tubers
Energy Technology Data Exchange (ETDEWEB)
Following tuber excision from the mother plant sucrose synthase activity fell from 3,120 to 960 nmol/g.f. wt./h within 7 days and starch synthesis ({sup 14}C sucrose incorporated into isolated discs) from 23 to 7 nmol/g.f. wt./h. While the maximum catalytic activity of sucrose synthase was more than sufficient to account for the observed rate of starch synthesis a maximum of 27% of sucrose incorporated by discs was converted into starch within 3 h. This compared with 80% conversion of {sup 14}C glucose incorporated. Tuber excision also reduced the rate of starch biosynthesis with glucose as a substrate (from 206 to 64 nmol/g.f. wt./h). The activities of UDPG-pyrophosphorylase, PPi-PFK, ATP-PFK, starch synthase and hexokinase (glucose or fructose substrates) were unaffected by tuber removal. ADPG pyrophosphorylase activity was reduced from 8,000 to 4,500 nmol/g.f. wt./h. Preliminary experiments indicate that the decline in sucrose synthease ...
1990-05-01
Quantitative bone scintigraphy in renal osteodystrophy
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 follow-up of renal ...
Proton G{sub E}/G{sub M} from beam-target asymmetry
The ratio of the proton's electric to magnetic form factor, G{sub E}/G{sub M}, can be extracted in elastic electron-proton scattering by measuring cross sections, beam-target asymmetry, or recoil polarization. Separate determinations of G{sub E}/G{sub M} by cross sections and recoil polarization observables disagree for Q{sup 2}>1 (GeV/c){sup 2}. Measurement by a third technique might uncover an unknown systematic error in either of the previous measurements. The beam-target asymmetry has been measured for elastic electron-proton scattering at Q{sup 2} = 1.51 (GeV/c){sup 2} for target spin orientation aligned perpendicular to the beam momentum direction. This is the largest Q{sup 2} at which G{sub E}/G{sub M} has been determined by a beam-target asymmetry experiment. The result, {mu}G{sub E}/G{sub M}=0.884{+-}0.027{+-}0.029, is compared to previous world data.
2006-09-15
Energy Technology Data Exchange (ETDEWEB)
Highly resistant, high-transmittance woodceramic thin films were prepared using rf magnetron sputtering of a woodceramic disk in argon plasma. A film series was deposited based on substrate temperature, which was varied from 50 to 500 degree C. The film's electrical and optical properties depended on substrate temperature. Films deposited below 300 degree C were insulative, {rho}>10{sup 10} {omega} {center_dot} cm. Films deposited at 50 degree C had a density of 1.9-2.2 g/cm{sup 3} comparable to that of single crystal graphite. Below 200 degree C, films had higher transmittance than typical DLC films in the visible and infrared region. Infrared C-H absorption spectrum was observed by Ft-IR and there exist two types of bonding corresponding to sp{sup 2} or SP{sup 3}. (author)
1999-08-01
Energy Technology Data Exchange (ETDEWEB)
The X-ray spectra of {approx}200 AGN collected from Swift-BAT were analyzed to test the Unified Model for AGN. Specifically, the photon indices, high energy cutoffs, and reflection components of Sy1 and Sy2 were compared. Under the Unified Model, the photon indices and reflection components for Sy1 should be larger than Sy2 and the high energy cutoffs should be the same. Fitting a simple power law model to the sample spectra proved to be insufficient. The PEXRAV model fit the spectra of the Sy1 and Sy2 significantly better, indicating that a reflection component and/or high energy cutoff exists as the Unified Model expects. Using both the simple power law and PEXRAV models it was concluded that in the population studied, Sy1 had a larger photon index than Sy2, as expected by the Unified Model. For Sy1 and Sy2, the reflection components were found to be compatible, but given the large errors, this finding cannot be said to be evidence against the Unified Model. ...
2010-08-25
Energy Technology Data Exchange (ETDEWEB)
Reductive quenching of two photoexcited ruthenium(II) complexes by an anionic electron donor, 2,2{prime}-azinobis(3-ethyl-benzothiazoline-6-sulfonate) (ABTS{sup 2{minus}}), in aqueous solution was examined by laser flash photolysis before and after adding positively charged colloidal (250-{angstrom} diameter) alumina-coated silica particles. The kinetics and quantum yields of electron transfer with an anionic sensitizer, RuL{sub 3}{sup 4{minus}} (L = bathophenanthroline disulfonate), and a cationic one, Ru(bpy){sub 3}{sup 2+} (bpy = 2,2{prime}-bipyridine), were compared. Coadsorption of ABTS{sup 2{minus}} and RuL{sub 3}{sup 4{minus}} by the particles greatly enhanced the rate of quenching such that only the reaction occurring on the surfaces of the particles was observed. Electron transfer from ABTS{sup 2{minus}} to RuL{sub 3}{sup 4-*} occurred by a static (nondiffusional) process, and the quenching efficiency was maximal when there was close ...
1989-02-23
Energy Technology Data Exchange (ETDEWEB)
Five corrosion probes were received from West Valley Nuclear Services for evaluation in simulated tank 8D-2 3rd-stage sludge wash slurry. The same waste slurry simulated was also used in a series of ongoing corrosion studies assessing the effects of in-tank sludge washing on the integrity of tank 8D-2. Two of the corrosion probes were installed in the coupon corrosion test vessels operating at {approximately}150{degrees}F to compare performance of the probes with that observed by coupon tests conducted in the same vessels. Corrosion rate data calculated from electrical resistance measurements of the corrosion probes were evaluated for this study using two slightly different approaches. One approach uses the total length of exposure of the probe to give a ``time-averaged`` value of the corrosion rate. The other approach uses a shorter period of time (relative to the length of the test) in the calculation of corrosion rate, and is referred to as ...
1994-07-01
Passivation behavior of SUS 304 stainless steel in neutral solutions at elevated temperature
International Nuclear Information System (INIS)
Cyclic voltammograms of SUS 304 stainless steel in various neutral solutions such as Na_2SO_4 at high temperature were measured, as a successive study to previous report in which effects of temperature and pH on polarization behavior of stainless steel were studied. In this measurement Ag/AgCl reference electrode and platinum counter electrode were used in a static autoclave lined with inconel. Passive films formed in various conditions were analysed by electron diffraction and Auger spectroscopy. Results obtained were compared with anodic behavior of iron, chromium and nickel and with thermodynamical stabilities of their compounds. The main results are summarized as follows. (1) Stainless steel shows such electrochemical behavior as active dissolution, passivation and transpassivation in a deaerated neutral solution at 250"0C after fully reductive treatment of the specimen. In air-saturated solution, the peak of active dissolution is not ...
1981-01-01
Energy Technology Data Exchange (ETDEWEB)
Onset of convection in a layer of couple-stress fluid-saturated porous medium is investigated for different types of basic temperature gradients. The boundaries are considered to be adiabatically insulated to temperature perturbations. The eigenvalue equations of the perturbed state obtained from the normal mode analysis are solved analytically using a regular perturbation technique with wave number as a perturbation parameter and also numerically using the Galerkin technique. The critical stability parameters obtained from these two techniques are in excellent agreement and an increase in the value of couple-stress parameter is found to delay the onset of convection. The results also indicate that the piecewise linear temperature profile hastens the onset of convection when compared to linear, parabolic, and inverted parabolic temperature profiles. In addition, the influence of thermal depth on the critical conditions is assessed in the case of piecewise linear ...
2010-08-15
On the bending response of Kevlar 49/epoxy beams and rings
Energy Technology Data Exchange (ETDEWEB)
Kevlar 49/epoxy laminates often exhibit substantial material nonlinearity when subjected to bending. This is a consequence of the yeild-like behavior of a Kevlar 49/epoxy lamina in fiber-directed compression. In this paper, analyses that utilize a simple idealization of compressive yielding are described and calculated results for Kevlar 49 reinforced beams and rings are compared with available data. First, results of a finite element analysis of a thin, unidirectionally reinforced ring subjected to diametral compression are presented. This analysis uses beam elements that incorporate linear tensile and elastic-perfectly plastic compressive behavior. Then a method used to analyze quasi-isotropic beams tested in four-point bending is discussed. This finite element analysis uses a layered shell element with a lamina constitutive model that permits elastic-perfectly plastic response to fiber-directed compression, but otherwise assumes linear elastic behavior. ...
1988-05-01
On the Dark Matter Solutions to the Cosmic Ray Lepton Puzzle
Recent measurements of cosmic ray leptons by PAMELA, ATIC, HESS and Fermi revealed interesting excesses. Many authors suggested particle Dark Matter (DM) annihilations could be at the origin of these effects. In this paper, we critically assess this interpretation by reviewing some results questioning the naturalness and robustness of such an interpretation. Natural values for the DM particle parameters lead to a poor leptons production so that models often require signal enhancement effects that we constrain here. Considering DM annihilations are likely to produce antiprotons as well, we use the PAMELA antiproton to proton ratio measurements to constrain a possible exotic contribution. We also consider the possibility of an enhancement due to a nearby clump of DM. This scenario appears unlikely when compared to the state-of-the-art cosmological N-body simulations. We conclude that the bulk of the observed signals most likely has no link with ...
2009-01-01
Observing the Sunyaev-Zel'dovich Effect Closer to Home
Hot gas trapped in a dark matter halo will produce a decrement in the surface brightness of the microwave background, the Sunyaev-Zel'dovich (SZ) effect. While massive clusters produce the strongest central SZ decrements, we point out that a local galaxy halo, specifically the halo of M31, may be one of the brightest integrated SZ sources in the sky. For various realistic gas distributions consistent with current X-ray limits, we show that the integrated SZ decrement from M31 will be comparable to decrements already detected in more distant sources, provided its halo contains an appreciable quantity of hot gas. A measurement of this decrement would provide direct information on the mass, spatial distribution and thermodynamic state of hot gas in a low-mass halo, and could place important constraints on current models of galaxy formation. Detecting such an extended (~ 10 degree), low-amplitude signal will be challenging, but should be possible with all-sky SZ maps ...
2003-01-01
Observations on computerized quantitative bone scintigraphy in renal osteodystrophy
Energy Technology Data Exchange (ETDEWEB)
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 quantitative skeletal analysis is a potentially ...
1984-09-01
Observations on computerized quantitative bone scintigraphy in renal osteodystrophy
International Nuclear Information System (INIS)
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 quantitative skeletal analysis is a potentially ...
We review results from general relativistic axisymmetric magnetohydrodynamic simulations of accretion in Sgr A*. We use general relativistic radiative transfer methods and to produce a broad band (from millimeter to gamma-rays) spectrum. Using a ray tracing scheme we also model images of Sgr A* and compare the size of image to the VLBI observations at 230 GHz. We perform a parameter survey and study radiative properties of the flow models for various black hole spins, ion to electron temperature ratios, and inclinations. We scale our models to reconstruct the flux and the spectral slope around 230 GHz. The combination of Monte Carlo spectral energy distribution calculations and 230 GHz image modeling constrains the parameter space of the numerical models. Our models suggest rather high black hole spin ($a_*\\approx 0.9$), electron temperatures close to the ion temperature ($T_i/T_e \\sim 3$) and high inclination angles ($i \\approx 90 \\deg$).
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
The reactions between (100) GaAs and the near-noble metals Ni, Pd, and Pt have been investigated by application of high-resolution transmission electron microscopy (TEM), energy-dispersive analysis of x rays in the scanning TEM and Rutherford backscattering spectrometry. Emphasis is placed on the evolution of the phase distributions, film compositions, and interface morphologies during annealing at temperatures up to 480 /sup 0/C. The first phase in the Ni/GaAs reaction is shown to have the nominal composition Ni/sub 3/GaAs. Ternary phases of the type Pd/sub x/GaAs are also found to be the dominant products of the Pd/GaAs reaction. Conversely, only binary phases result from the Pt/GaAs reaction. These observations are used to construct isothermal sections of the M--Ga--As thin-film phase diagrams. The behavior of a thin (1--2 nm) native oxide--hydrocarbon layer during the Ni/GaAs, Pd/GaAs, and Pt/GaAs reactions is also investigated. Only the Ni/GaAs reaction is ...
1987-03-01
New constraints on the primordial black hole number density from Galactic gamma-ray astronomy
Primordial black holes are unique probes of cosmology, general relativity, quantum gravity and non standard particle physics. They can be considered as the ultimate particle accelerator in their last (explosive) moments since they are supposed to reach, very briefly, the Planck temperature. Upper limits on the primordial black hole number density of mass $M_{\\star} = 5 10^{14}$ g, the Hawking mass (born in the big-bang terminating their life presently), is determined comparing their predicted cumulative $\\gamma$-ray emission, galaxy-wise, to the one observed by the EGRET satellite, once corrected for non thermal $\\gamma$-ray background emission induced by cosmic ray protons and electrons interacting with light and matter in the Milky Way. A model with free gas emissivities is used to map the Galaxy in the 100 MeV photon range, where the peak of the primordial black hole emission is expected. The best gas emissivities and additional model ...
2009-01-01
Neutrino-induced pion production from nuclei at medium energies
We present a fully relativistic formalism for describing neutrino-induced $\\Delta$-mediated single-pion production from nuclei. We assess the ambiguities stemming from the $\\Delta$ interactions. Variations in the cross sections of over 10% are observed, depending on whether or not magnetic-dipole dominance is assumed to extract the vector form factors. These uncertainties have a direct impact on the accuracy with which the axial-vector form factors can be extracted. Different predictions for $C_5^A(Q^2)$ induce up to 40-50% effects on the $\\Delta$-production cross sections. To describe the nucleus, we turn to a relativistic plane-wave impulse approximation (RPWIA) using realistic bound-state wave functions derived in the Hartree approximation to the $\\sigma$-$\\omega$ Walecka model. For neutrino energies larger than 1 GeV, we show that a relativistic Fermi-gas model with appropriate binding-energy correction produces comparable results as ...
2008-01-01
Multidimensional two-phase flow regime distribution in a PWR downcomer during an LBLOCA refill phase
Energy Technology Data Exchange (ETDEWEB)
The multidimensional countercurrent two-phase flow regimes that occur in a pressurized-water reactor (PWR) vessel downcomer during the refill phase of a large-break loss-of-coolant accident are studied using a transparent 1/10 scale model of a PWR vessel. The various flow regimes and their distribution in the downcomer have been identified and mapped for a range of air-water flooding experiments. The two-phase flow patterns that are identified in the downcomer included various types of film flows, droplet flows, countercurrent churn flows and cocurrent flows depending on the flooding condition. Through observation of the two-phase flow dynamics it was deduced that the physical mechanisms associated with the flooding processes could be separated into a liquid entrainment process and a film flow reversal process. In addition to the above exercise, the effect of non-uniform injection of water into the downcomer via different combinations of cold leg was studied ...
1994-09-01
Multidimensional two-phase flow regime distribution in a PWR downcomer during an LBLOCA refill phase
International Nuclear Information System (INIS)
The multidimensional countercurrent two-phase flow regimes that occur in a pressurized-water reactor (PWR) vessel downcomer during the refill phase of a large-break loss-of-coolant accident are studied using a transparent 1/10 scale model of a PWR vessel. The various flow regimes and their distribution in the downcomer have been identified and mapped for a range of air-water flooding experiments. The two-phase flow patterns that are identified in the downcomer included various types of film flows, droplet flows, countercurrent churn flows and cocurrent flows depending on the flooding condition. Through observation of the two-phase flow dynamics it was deduced that the physical mechanisms associated with the flooding processes could be separated into a liquid entrainment process and a film flow reversal process. In addition to the above exercise, the effect of non-uniform injection of water into the downcomer via different combinations of cold leg was studied ...
1993-10-01
Mott-Schwinger Scattering of Polarized Low Energy Neutrons up to Thermal Energies
Energy Technology Data Exchange (ETDEWEB)
The availability of new, high-intensity, cold and thermal neutron sources has opened the possibility of performing high-precision fundamental neutron physics experiments, including measurements that study the hadronic weak interaction and standard model test measurements, using neutron decay. The observables in these experiments are usually correlated with the direction of neutron polarization and are often very small (10 8 10 6). Mott-Schwinger scattering of polarized neutrons can produce spin-dependent shifts in beam centroids, which has the potential to produce significant systematic effects for these types of experiments. An accurate calculation of this process for neutral atoms and basic molecules has not been carried out for low neutron energies. In this work, we derive a general expression for the electromagnetic (Mott-Schwinger) contributions to the analyzing power for low-energy neutron scattering. We obtain numerical results for 11 nuclei in the range of ...
2008-10-01
Monte-Carlo simulations of 2-MeV #alpha#-particle channeling in Si_1_-_xSn_x alloy
International Nuclear Information System (INIS)
Monte-Carlo simulations of 2-MeV #alpha#-particle channeling in Si_1_-_xSn_x alloys with 0#<=#x#<=#1 have been performed. The simulations are compared with measured channeling-angular scans for strained Si_0_._9_5Sn_0_._0_5 layers grown by molecular beam epitaxy (MBE). Agreement between simulated and measured angular scans can only be achieved if we assume a deviation of the crystal structure from the ideal one. This deviation can be attributed to a mosaic structure in the films and to an atomic-scale distortion of the crystal lattice due to an expected difference in the bond lengths between the Si-Si, Si-Sn and Sn-Sn atoms (such a difference in bond lengths has been observed in the epitaxial Si_1_-_xGe_x system). The contributions from both of these imperfections are estimated and discussed.
2000-04-01
In previous molecular phylogenetic analyses of the freshwater mussel family Unionidae (Bivalvia: Unionoida), the Afrotropical genus Coelatura had been recovered in various positions, generally indicating a paraphyletic Unionidae. However that result was typically poorly supported and in conflict with morphology-based analyses. We set out to test the phylogenetic position of Coelatura by sampling tropical lineages omitted from previous studies. Forty-one partial 28S nuclear rDNA and partial COI mtDNA sequences (1130 total aligned nucleotides) were analyzed separately and in combination under both maximum parsimony and likelihood, as well as Bayesian inference. There was significant phylogenetic incongruence between the character sets (partition homogeneity test, p<0.01), but a novel heuristic for comparing bootstrap values among character sets analyzed separately and in combination illustrated that the observed conflict was due to homoplasy ...
2011-07-30
Modulation of gene expression in differentiating 3T3 - L1 preadipocytes
Energy Technology Data Exchange (ETDEWEB)
3T3 - L1 cells can be induced to differentiate by exposing cell culture to a medium containing 3-isobutyl-1-methyl-xanthine together with insulin and dexamethasone. They have observed that oxalomalate (OMA) which inhibits aconitase thus blocking the citric cycle, also favours differentiation to adipocytes leading to fatty acids accumulation and increased synthesis of specific proteins. They compared the effects of 3-isobutyl-1-methyl-xanthine-insulin-dexamethasone and OMA on the steady-state levels of mRNA of c / EBP, H-ferritin and aconitase / IRE-BP. OMA does not affect the steady-state mRNA amount of C / EBP, H-ferritin and aconitase / IRE-BP but the 3-isobutyl-1-methyl-xanthine-insulin-dexamethasone mixture is able to induce a five-fold increase of mRNA levels for aconitase / IRE-BP. This is the first finding correlating iron metabolism to adipocyte differentiation. Further studies will clarify a possible role for the aconitase inhibitor ...
1997-12-31
Energy Technology Data Exchange (ETDEWEB)
Microstructural evolution due to thermal effects was studied in micro solder joints (55 {+-} 5 {micro}m). The composition of the Sn/Pb solder studied was found to be hypereutectic with a tin content of 65--70 wt%.This was determined by Energy Dispersive X-ray analysis and confirmed with quantitative stereology. The quantitative stereological value of the surface-to-volume ratio was used to characterize and compare the coarsening during thermal cycling from 0--160 C to the coarsening during annealing at 160 C. The initial coarsening of the annealed samples was more rapid than the cycled samples, but tapered off as time to the one-half as expected. Because the substrates to which the solder was bonded have different thermal expansion coefficients, the cycled samples experienced a mechanical strain with thermal cycling. The low-strain cycled samples had a 2.8% strain imposed on the solder and failed by 1,000 cycles, despite undergoing less coarsening than the annealed ...
1998-12-01
Energy Technology Data Exchange (ETDEWEB)
The Natural Gas Vehicle Challenge `92, organized by Argonne National Laboratory and sponsored by the US Department of Energy, the Energy, Mines, and Resources - Canada, the Society of Automotive Engineers, and many others, resulted in 20 varied approaches to the conversion of a gasoline-fueled, spark-ignited, internal combustion engine to dedicated natural gas use. Starting with a GMC Sierra 2500 pickup truck, donated by General Motors, teams of college and university student engineers strived to optimize Chevrolet V-8 engines operating on natural gas for improved emissions, fuel economy, performance, and advanced design features. This paper focuses on the results of the emission event, and compares engine mechanical configurations, engine management systems, catalyst configurations and locations, and approaches to fuel control and the relationship of these parameters to engine-out and tailpipe emissions of regulated exhaust constituents. Nine of the ...
1992-09-01
International Nuclear Information System (INIS)
Classification and ranking of the solid solution on their reaction to the irradiation is suggested on the basis of binary system structure controlled by mixing enthalpy sign, melting temperatures relation of components and solidus curves slope. Several combinations of these characteristics permit to pick out three groups of substitutional elements capable of forming the vacancy-solute atom complexes either low-mobile or fast-mobile ones as compared to monovacancies migration. The radiation hardening (and embrittlement) of binary alloys should be intensified respectively either due to heterogeneous point defect clusters nucleation on solute traps or due to solute atom clusters/ precipitate formation. A local cohesion decrease may also occur especially if low-melting elements (characterized by low surface energy) are segregating on internal sinks or grain boundaries. The predicted specifics of different alloy group under irradiation and during post-irradiation ...
1994-06-20
International Nuclear Information System (INIS)
Precise measurements of the single spin asymmetry AN, and the double spin asymmetry ANN, in proton-proton (pp) elastic scattering in the region of four-momentum transfer squared 0.0012 have been performed using a polarized atomic hydrogen gas jet target and the Relativistic Heavy Ion Collider (RHIC) polarized proton beam. We present measurements of AN and ANN at center-of-mass energies ?(s)=6.8 and 13.7 GeV. These spin-dependent observables are sensitive to the poorly known hadronic spin-dependent amplitudes. Comparing AN at different energies, a ?(s) dependence of the hadronic single spin-flip amplitude is suggested. A hadronic double spin-flip amplitude from the ANN data is consistent with zero within a 2-? level. We also present ??T, estimated from the measured ANN data. The results for ??T are consistent with zero. Our results provide significant constraints toward a comprehensive understanding of the reaction mechanism for pp elastic ...
2009-05-01
Energy Technology Data Exchange (ETDEWEB)
Yields of light fission products (A = 68, 70-84, 87, 88, 94, 96, 98, 102 and 106-108), their kinetic energies and nuclear charge distributions (A 71-84, 87 and 88) in the thermal neutron induced fission of the odd-Z nucleus {sup 242m}Am(Z = 95) were measured using the mass-separator Lohengrin at the Institute Laue-Langevin in Grenoble (France). The mass yield curve shows a fine structure at A = 70, probably due to shell and/or odd-even effects affecting also the nuclear charge distribution. The analysis of isotopic chain yields gives evidence for a very low excitation energy of the lightest fission fragments observed. A preferential formation of fragments with even Z is found for this odd-Z compound nucleus. Calculated values for the local odd-even effect are comparable with those for the neighbouring even-Z fissile nuclides and increase from 13% to 30% with increasing asymmetry of the mass split (A{sub L} = 84 to 68 and Z{sub L} = 35 to 28). ...
1999-10-25
MEMS-based Speckle Spectrometer
We describe a new concept for a MEMS-based active spatial filter for astronomical spectroscopy. The goal of this device is to allow the use of a diffraction-limited spectrometer on a seeing limited observation at improved throughput over a comparable seeing-limited spectrometer, thus reducing the size and cost of the spectrometer by a factor proportional to r0/D (For the case of a 10 meter telescope this size reduction will be approximately a factor of 25 to 50). We use a fiber-based integral field unit (IFU) that incorporates an active MEMS mirror array to feed an astronomical spectrograph. A fast camera is used in parallel to sense speckle images at a spatial resolution of lambda/D and at a temporal frequency greater than that of atmospheric fluctuations. The MEMS mirror-array is used as an active shutter to feed speckle images above a preset intensity threshold to the spectrometer, thereby increasing the signal-to-noise ratio (SNR) of the ...
2006-01-01
Low-energy measurements of electron capture by multicharged ions from excited hydrogen atoms
International Nuclear Information System (INIS)
For very low collision energies electron capture from excited hydrogen by multicharged ions is characterized by enormous cross sections, the predicted maximum being comparable to the geometric size of the Rydberg atom. The ion-atom merged-beams technique is being used to study these collisions for the variety of charge states and the wide range of energies (0.1 to 1000 eV/amu) accessible to the apparatus. A neutral D beam containing a Rydberg atom population proportional to 1/n"3 is produced by collisional electron detachment of 8 keV D"- in N_2 gas. An applied electric field results in the range (n=24--11) depending on the strength of the field applied. This beam is then merged with O"3"+ or O"5"+ ion beams at low relative collision velocities where the resultant beam-beam signal of D"+ due to electron loss is dominated by electron capture. From the sharp decrease in the observed beam-beam signal as the electric field increases it is inferred ...
Energy Technology Data Exchange (ETDEWEB)
An attempt was made to minimize the channeling tail by implantation along a random equivalent direction following a careful alignment of the target. In order to analytically determine the random equivalent directions, critical angles for channeling were mapped on a stereogram. Boron ions with energies of 17 and 45 keV are implanted along specified directions determined from the map. The depth distribution of the dopant is profiled by SIMS and the effects of water orientation upon the channeling tail are noted. Industrial common use of a 7/sup 0/ tilt is not optimum. However, implantation with the wafer tilted at 5.5 +/- 0.5/sup 0/ from the surface normal and rotated at 7.0 +/- 0.5/sup 0/ from a (100) plane shows the least channel-tail compared to implantation along other directions. Rapid thermal annealing (RTA) is a promising annealing method for shallow junction formation. Transient enhanced diffusion of implanted boron is observed. Two ...
1985-01-01
International Nuclear Information System (INIS)
An attempt was made to minimize the channeling tail by implantation along a random equivalent direction following a careful alignment of the target. In order to analytically determine the random equivalent directions, critical angles for channeling were mapped on a stereogram. Boron ions with energies of 17 and 45 keV are implanted along specified directions determined from the map. The depth distribution of the dopant is profiled by SIMS and the effects of water orientation upon the channeling tail are noted. Industrial common use of a 7"0 tilt is not optimum. However, implantation with the wafer tilted at 5.5 +/- 0.5"0 from the surface normal and rotated at 7.0 +/- 0.5"0 from a (100) plane shows the least channel-tail compared to implantation along other directions. Rapid thermal annealing (RTA) is a promising annealing method for shallow junction formation. Transient enhanced diffusion of implanted boron is observed. Two different mechanisms ...
Long term mineralogical changes in salt formations due to water and brine interactions
International Nuclear Information System (INIS)
Four very common long term mineralogical changes in salt formations are discussed in the view of the safety considerations for underground repositories. Two of these processes, the 'Hartsalz' and 'Carnallite' dissolution were studied in two scale in situ experiments. The results are presented and compared with the results of the geochemical modelling with the computer code EQ3/6. Furthermore the reactions leading to the formation of the gypsum cap rock on the top of the Zechstein salt formations and to the polyhalitization of anhydrite are discussed. Geological field observations and mineral assemblages agree well with the results of the geochemical modelling employing the Pitzer formalism along with the Harvie, Moller and Weare database. We conclude that once the mechanisms of the chemical reactions are well understood it becomes possible to evaluate realistically whether such processes, when encountered in the repository, are still active or ...
1994-09-01
K beta X-ray transition energies of M-shell-ionized ions of Ti through Ni in a plasma
Energy Technology Data Exchange (ETDEWEB)
K beta X-ray lines from partially M-shell-ionized ions of titanium through nickel which are produced in vacuum-spark plasmas have been observed systematically for the first time, using a high-resolution curved-crystal spectrometer. Each K beta line is clearly separated into its corresponding charge state. As a result, it is possible to measure the K beta-type transition energies of the M-shell-ionized ions. The transition energies accurately determined are compared with those calculated for iron ions, and the agreement is excellent except for ions having some additional 3d outer-shell electrons or 3s inner-shell vacancies. The square root of the K beta transition frequency is expressed as a linear function of the nuclear charge for isoelectronic sequences. The effective nuclear charges have been also determined for each K beta transition. The 3p electrons do not affect the effective nuclear charges. 10 references.
1985-05-01
Isotope exchange reaction between tritiated water and hydrogen on SiC
Energy Technology Data Exchange (ETDEWEB)
SiC has been considered as a primary candidate material for a first wall component in future fusion reactor because it has been claimed that SiC has excellent high-temperature properties, good chemical stability and low activation. However, the behavior of tritium on SiC has not been discussed yet. In this study, tritium trapping capacity on the surface of SiC was experimentally obtained at the temperature range of 25-800 deg. C in consideration of tritium trapping to the experimental system. The capacity, which was independent of the water vapor pressure in the gas phase and the temperature, was determined as about 10{sup 6} Bq/cm{sup 2}. The isotope exchange reaction rate between tritiated water in a gas phase and hydrogen on the surface was quantified at the temperature of 25, 500 and 700 deg. C in consideration of the behavior of tritium trapping at change of experimental condition by the numerical curve fitting method applying the serial reactor model. The reaction rate was ...
2003-11-15
Isotope exchange reaction between tritiated water and hydrogen on SiC
International Nuclear Information System (INIS)
SiC has been considered as a primary candidate material for a first wall component in future fusion reactor because it has been claimed that SiC has excellent high-temperature properties, good chemical stability and low activation. However, the behavior of tritium on SiC has not been discussed yet. In this study, tritium trapping capacity on the surface of SiC was experimentally obtained at the temperature range of 25-800 deg. C in consideration of tritium trapping to the experimental system. The capacity, which was independent of the water vapor pressure in the gas phase and the temperature, was determined as about 10"6 Bq/cm"2. The isotope exchange reaction rate between tritiated water in a gas phase and hydrogen on the surface was quantified at the temperature of 25, 500 and 700 deg. C in consideration of the behavior of tritium trapping at change of experimental condition by the numerical curve fitting method applying the serial reactor model. The reaction rate was ...
2003-11-15
Ion mixing of near-noble monosilicides with Si substrates
Energy Technology Data Exchange (ETDEWEB)
Xe ion irradiation of NiSi, PdSi, and PtSi on Si was performed at various substrate temperatures. The phase formation and mixing behavior of the three monosilicides with their Si substrates are quite different. For NiSi, NiSi/sub 2/ was formed on amorphous Si substrates at 350 /sup 0/C, while NiSi remained stable on crystalline Si substrates even at 400 /sup 0/C. PtSi reacted with Si to form a metastable Pt/sub 4/Si/sub 9/ phase, which decomposed back to PtSi and Si by successive irradiation at higher temperatures. The decomposition of the metastable Pt/sub 4/Si/sub 9/ was easier on crystalline Si substrates than on amorphous substrates. No mixing was observed for PdSi on Si in the temperature range of 35--400 /sup 0/C. The ion mixing results were compared with those from thermal annealing. The importance of demixing of a thermally stable system was explored.
1989-05-01
Ion mixing of near-noble monosilicides with Si substrates
International Nuclear Information System (INIS)
Xe ion irradiation of NiSi, PdSi, and PtSi on Si was performed at various substrate temperatures. The phase formation and mixing behavior of the three monosilicides with their Si substrates are quite different. For NiSi, NiSi_2 was formed on amorphous Si substrates at 350 "0C, while NiSi remained stable on crystalline Si substrates even at 400 "0C. PtSi reacted with Si to form a metastable Pt_4Si_9 phase, which decomposed back to PtSi and Si by successive irradiation at higher temperatures. The decomposition of the metastable Pt_4Si_9 was easier on crystalline Si substrates than on amorphous substrates. No mixing was observed for PdSi on Si in the temperature range of 35--400 "0C. The ion mixing results were compared with those from thermal annealing. The importance of demixing of a thermally stable system was explored.
International Nuclear Information System (INIS)
Production treatment chemicals represent a diverse collection of chemical classes, added at various points from the wellhead to the final flotation cell, to prevent operational upsets and enhance the separation of oil from water. Information in the literature indicates that while many treatment chemicals are thought to partition into oil and not into the produced water, there are cases where a sufficiently water soluble treatment chemical is added at high enough concentrations to suggest that the treatment chemical may add to the aquatic toxicity of the produced water. A study was conducted to evaluate the potential effect of production treatment chemicals on the toxicity of produced waters using the US EPA Seven-day Mysidopsis bahia Survival, Growth and Fecundity Test. Samples of produced water were collected and tested for toxicity from three platforms under normal operating conditions, followed by repeated sampling and testing after a 72-hour period in which treatment chemical usage ...
1993-11-14
Investigation of cardio-vascular reflex in atomic bomb survivors, (2)
Energy Technology Data Exchange (ETDEWEB)
Electrographic R-R interval variation was examined in a total of 915 A-bomb survivors exposed at {<=}2,000 m from the hypocenter (the {<=} 2,000 m group) and a total of 1,162 A-bomb survivors exposed at >3,000 m or entered the city after the A-bombing (the >3,000 m group). Coefficient of variation (CV) for R-R interval variation on ECG tended to be decreased with advancing age in the >3,000 m group, irrespective of sex. Especially for men in this group, CV values were significantly lower for the age group of 45 to 54 years than the groups of 65 to 74 years and 75 to 84 years. Similar tendency was observed for CV values at deep breath. Decreased CV values tended to be associated with a decrease in glucose tolerance in both men and women of the >3,000 m group. In comparing the aforementioned CV values with those in the {<=}2,000 m group, there was no significant difference between the groups. R-R interval variation on ECG was ...
1990-11-01
International Nuclear Information System (INIS)
Theoretical interpretation of fast-charged-particle spectra, observed in the #alpha#-particle-induced reactions on the s-d shell nuclei (A = 24-28), in terms of the Intranuclear Cascade Model and the GDH exciton model (ALICE) is presented. The de-excitation of the excited residual nuclei is accounted for by the evaporation process. The theoretically predicted fast-proton and #alpha#' spectral shapes compare reasonably well with the corresponding measured spectra. However, the magnitude depends critically (as expected) on the reaction cross section employed by the model. As a first step to improve the model predictability of the reaction products, a closer look at the calculation of the #alpha#-particle reaction cross sections was undertaken. A microscopic approach using the optical theorem of Glauber's theory was employed to estimate the #alpha#-induced reaction cross sections for the light target nuclei under consideration. The calculated ...
International Nuclear Information System (INIS)
Megavoltage photon intensity-modulated radiation therapy (IMRT) is typically used in the treatment of prostate cancer at our institution. Approximately 1% to 2% of patients with prostate cancer have hip prostheses. The presence of the prosthesis usually complicates the planning process because of dose perturbation around the prosthesis, radiation attenuation through the prosthesis, and the introduction of computed tomography artifacts in the planning volume. In addition, hip prostheses are typically made of materials of high atomic number, which add uncertainty to the dosimetry of the prostate and critical organs in the planning volume. When the prosthesis is bilateral, treatment planning is further complicated because only a limited number of beam angles can be used to avoid the prostheses. In this case study, we will report the observed advantages of using noncoplanar beams in the delivery of IMRT to a prostate cancer patient with bilateral hip prostheses. The ...
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
The infrastructure of the Mexican southeastern coastal zone is affected by corrosion problems which are due, mainly, to the construction bad practices and to the aggressive environmental agents (temp., Relative Humidity, chlorides). The first actions for knowing and controlling them have been taken on the coast of Progreso, Yucatan. Cylinders of solid concrete and others with an embedded rebar were constructed and exposed to the marine environment studying different variables like w/c ratio, time of curing, coated and uncoated rebars, chlorides and CO{sub 2} penetration and place of exposure with respect to the seashore. The cylinders were tested through corrosion potential and polarization resistance measurements in order to detect, in a first stage, the onset and propagation stages of the corrosion processes and to correlate the apparent corrosion current density (Icorr.) with the chloride concentration in the rebar surface. These results are discussed and ...
1995-10-01
International Nuclear Information System (INIS)
The inelastic energy losses for single collisions of Xe"+ ions with Xe targets have been measured for incident ion energies from 0.3 to 1.2 MeV and for scattering angles from 3"0 to 20"0. The energy losses were found to range from 1 to 11 keV with distinct steps at distances of closest approach of 0.22 and 0.12 A. By comparing these data with earlier ionization data by the same authors these steps are shown to be caused by M-shell excitation. Other excitations observed in the ionization data may be attributed to N-shell excitation. The distances of closest approach at which these excitations occur agree well with calculations by Eichler and Wille and co-workers, giving further evidence of the usefulness of Fano and Lichten's one-electron molecular model and these calculations.
International Nuclear Information System (INIS)
Studies of collisions between Rydberg atoms with values of principal quantum number n in the range 100 approx-lt n approx-lt 400 and H_2S and C_6H_5NO_2 are reported. These targets were selected because they have very different dipole moments: 0.97 and 4.22 D, respectively. Analysis of the data using the essentially-free-electron model shows that at micro-electron-volt energies the cross sections for rotationally inelastic electron scattering by these targets have very different energy dependences. This difference suggests that, in the case of C_6H_5NO_2, dipole-supported states might be important in the scattering. To examine this further, the data are compared with the results of calculations using a free-electron cross section that assumes the presence of dipole-supported states, and it is demonstrated that, with a reasonable choice of parameters, it is possible to reproduce the experimental observations.
Energy Technology Data Exchange (ETDEWEB)
The expression of three c-onc genes (c-erb, c-myc, c-myb) was investigated in five cell lines established from fibrosarcomas induced with 20-methylcholanthrene (MCA) of Japanese quails. These cell lines showed low levels of the three c-onc genes, with the exception of two cell lines that accumulated moderate (MCAQ 1-4) and large amounts (MCAQ 3-5) of c-myc RNA. Molecular cloning and restriction endonuclease analyses indicated that expression of c-myc in these two cell lines were not associated with detectable rearrangements in the c-myc locus, that the size of the c-myc transcript (2.7 kb) in MCAQ 3-5 was similar to that of the normal c-myc messenger RNAs (mRNA) and that the transcriptional activatin observed in MCAQ 3-5 was not mediated by the LTR (long terminal repeat) of a proximate ALV (avian leukosis virus) provirus. Finally, when analyzed with the restriction enzymes Msp I and Hpa II, the c-myc locus of MCAQ 3-5 and MCAQ 1-4 was found hypomethylated as ...
1984-12-01
Implantation damage and anomalous diffusion of implanted boron in silicon through SiO_2 films
International Nuclear Information System (INIS)
Boron is implanted in crystalline silicon through oxide layers with different thicknesses. The implantation is carried out at various doses and energies of interest in ultra large scale integration (ULSI) application. Rapid thermal annealings (RTA) are used to obtain shallow junctions and electrical activation of the B atoms. However, transient enhanced diffusion induced by implantation damage can be observed. The boron concentration profiles before and after annealing are obtained with secondary ion mass spectrometry (SIMS). It is found that the diffusion transient in the tail region of the boron profile increases with decreasing oxide thickness. Even more, if the implantation damage concerns mostly the oxide, i.e. when the concentration peak is located in this oxide, the oxygen knocked into the silicon substrate could play this way an important role in restricting the boron diffusion, which is good to obtain very shallow junctions. On the other hand, for thinner ...
Implantation damage and anomalous diffusion of implanted boron in silicon through SiO[sub 2] films
Energy Technology Data Exchange (ETDEWEB)
Boron is implanted in crystalline silicon through oxide layers with different thicknesses. The implantation is carried out at various doses and energies of interest in ultra large scale integration (ULSI) application. Rapid thermal annealings (RTA) are used to obtain shallow junctions and electrical activation of the B atoms. However, transient enhanced diffusion induced by implantation damage can be observed. The boron concentration profiles before and after annealing are obtained with secondary ion mass spectrometry (SIMS). It is found that the diffusion transient in the tail region of the boron profile increases with decreasing oxide thickness. Even more, if the implantation damage concerns mostly the oxide, i.e. when the concentration peak is located in this oxide, the oxygen knocked into the silicon substrate could play this way an important role in restricting the boron diffusion, which is good to obtain very shallow junctions. On the other hand, for thinner ...
1993-07-16
Hot Nights on Extrasolar Planets: Mid-IR Phase Variations of Hot Jupiters
We present results from Spitzer Space Telescope observations of the mid-infrared phase variations of three short-period extrasolar planetary systems: HD 209458, HD 179949 and 51 Peg. We gathered IRAC images in multiple wavebands at eight phases of each planet's orbit. We find the uncertainty in relative photometry from one epoch to the next to be significantly larger than the photon counting error at 3.6 micron and 4.5 micron. We are able to place 2-sigma upper limits of only 2% on the phase variations at these wavelengths. At 8 micron the epoch-to-epoch systematic uncertainty is comparable to the photon counting noise and we detect a phase function for HD 179949 which is in phase with the planet's orbit and with a relative peak-to-trough amplitude of 0.00141(33). Assuming that HD 179949b has a radius R_J < R_p < 1.2R_J and a small Bond albedo, it must recirculate less than 30% of incident stellar energy to its night side at the 1-sigma ...
2007-01-01
High-dose neutron-irradiation effects in fcc metals at 4.6 K
International Nuclear Information System (INIS)
The rate of residual-resistivity increase and the isochronal recovery have been studied on the fcc metals Al, Ni, Cu, Pd, Ag, Pt, and Au irradiated at 4.6 K with reactor neutrons to a dose of about 10"1"9 (fast neutrons)/cm"2. The rate of resistivity increase is nonlinear as a function of irradiation-induced resistivity; computer analysis shows that the data are best fitted with an erxpression having up to third-order terms in #DELTA#rho. There are deviations from simple damage-rate theory in all cases, but an anomalous negative deviation from a linear law (convex curvature) is observed in Ni, Pd, Pt (and Fe). This behavior is most probably caused by a decrease of the specific Frenkel-defect resistivity due to defect clustering, an effect which should contribute in all metals after fast-neutron irradiation to high doses. Saturation values of resistivity and defect concentration as well as recombination volumes have veen obtained more accurately than from previous ...
1977-12-01
High tunability of pulsed laser deposited Ba0.7Sr0.3TiO3 thin films on perovskite oxide electrode
British Library Electronic Table of Contents (United Kingdom)
Ferroelectric thin films such as BST, PZT and PLZT are extensively being studied for the fabrication of DRAMS since they have high dielectric constant. The large and reversible remnant polarization of these materials makes it attractive for nonvolatile ferroelectric RAM application. In this paper we report the characterization of Ba0.7Sr0.3TiO3 (BST) thin films grown by pulsed laser ablation on oxide electrodes. The structural and electrical properties of the fabricated devices were studied. Growth of crystalline BST films was observed on La0.5Sr0.5CoO3 (LSCO) thin film electrodes at relatively low substrate temperature compared to BST grown on PtSi substrates. Electrical characterization was carried out by fabricating PtSi/LSCO/BST/LSCO heterostructures. The leakage current of the heteros...
2011-01-01
Higgs friends and counterfeits at hadron colliders
We consider the possibility of "Higgs counterfeits" - scalars that can be produced with cross sections comparable to the SM Higgs, and which decay with identical relative observable branching ratios, but which are nonetheless not responsible for electroweak symmetry breaking. We also consider a related scenario involving "Higgs friends," fields similarly produced through gg fusion processes, which would be discovered through diboson channels WW, ZZ, gamma gamma, or even gamma Z, potentially with larger cross sections times branching ratios than for the Higgs. The discovery of either a Higgs friend or a Higgs counterfeit, rather than directly pointing towards the origin of the weak scale, would indicate the presence of new colored fields necessary for the sizable production cross section (and possibly new colorless but electroweakly charged states as well, in the case of the diboson decays of a Higgs friend). These particles could easily be ...
2011-01-01
Genetic organization of Bungarus multicinctus protease inhibitor-like proteins.
The structural organization of the genes encoding Bungarus multicinctus protease inhibitor-like proteins (PILPs), PILP-1, PILP-2 and PILP-3, are reported in this study. Unlike PILP-2 and PILP-3, recombinant PILP-1 exhibited inhibitory activity on trypsin. PILP genes and B chain genes shared identical organization with three exons interrupted by two introns in similar positions. On the contrary, intron 1 of these genes had a similar size, a notable variation with the size of intron 2 was observed. It was found that two regions at the second intron of B1 chain and B2 chain genes were absent in that of PILP genes. Noticeably, intronic insertion in the second intron of B chain genes appeared in the promoter region of PILP-1 gene, but not in that of PILP-2 and PILP-3 genes. Comparative analyses of PILP genes and B chain genes showed that the protein-coding regions of the exons are more diverse than introns, except for in the signal peptide domain. ...
2008-03-27
International Nuclear Information System (INIS)
The new proton-induced nuclear reaction data for C, Fe, Cu and Pb for KASKAD-S have been generated using a newly developed data preparation system. The new system utilizes the NJOY and TRANSX codes to prepare these data with the latest evaluation instead of using the SADCO code with the built-in nuclear data. Auxiliary codes have been developed to help the conversion of TRANSX output into the reaction data for running the KASKAD-S. The basic nuclear data selected for this work are the LA150 and KAERI high energy files whose energy ranges are up to 150 and 250 MeV, respectively. The total neutron yields were calculated using KASKAD-S and the new reaction data up to 250 MeV bombarding energy. The calculations were compared with the measurements or MCNPX calculations when the measured data were absent. The comparison shows that our calculations give an overall good agreement with the measurements and MCNPX calculations except around 30 MeV where large discrepancies ...
2003-10-01
Generation of ammonia plasma using a helical antenna and nitridation of GaAs surface
International Nuclear Information System (INIS)
Using the ammonia (NH3) plasma generated by a helical antenna surrounded by two magnetic coils, the transition of the discharge mode from low-density plasma to high-density one was observed. At the transition, the emission intensities from the H atoms and NH radicals especially increased in the optical emission spectroscopy, while the intensities of the other emission lines also increased abruptly. The nitridation of gallium arsenide (GaAs) surface was performed using the high-density NH3 plasma, and the properties of the nitrided surface layer were compared with those nitrided by high-density N2 plasma using the same apparatus. From the spectroscopic ellipsometry measurements, the thickness of the nitrided layer was estimated to be 16-18 nm, while that by N2 was 3-4 nm. From the Ga 3d spectra, the contamination with oxygen in the nitridation layer by NH3 plasma was less than that by N2 plasma.
2003-05-15
International Nuclear Information System (INIS)
In this paper, we present the results of Plasma-Enhanced Chemical Vapor Deposition gate-oxide (SiO_2) integrity on ELC (excimer-laser-crystallized), MILC (metal-induced lateral-crystallized) and SPC (solid-phase-crystallized) polysilicon films. We observed that gate oxide strength of poly-Si TFT strongly depends on the crystallization method for the active silicon layer. In the case of ELC films, asperities on the silicon surface reduce the SiO_2 breakdown field significantly. The metallic contaminants in MILC films are responsible for a deleterious impact on gate oxide integrity. Among the three cases, the SiO_2 breakdown field was the highest for the SPC silicon films. The breakdown fields at the 50 % failure points in Weibull plots for the ELC, MILC and SPC cases were 5.1 MV/cm, 6.2 MV/cm, and 8.1 MV/cm, respectively. We conclude that the roughness and metallic contamination of the poly-Si films are the main factors that cause enhanced breakdown of SiO_2 films.
2006-01-01
Fused Silica Final Optics for Inertial Fusion Energy: Radiation Studies and System-Level Analysis
International Nuclear Information System (INIS)
The survivability of the final optic, which must sit in the line of sight of high-energy neutrons and gamma rays, is a key issue for any laser-driven inertial fusion energy (IFE) concept. Previous work has concentrated on the use of reflective optics. Here, we introduce and analyze the use of a transmissive final optic for the IFE application. Our experimental work has been conducted at a range of doses and dose rates, including those comparable to the conditions at the IFE final optic. The experimental work, in conjunction with detailed analysis, suggests that a thin, fused silica Fresnel lens may be an attractive option when used at a wavelength of 351 nm. Our measurements and molecular dynamics simulations provide convincing evidence that the radiation damage, which leads to optical absorption, not only saturates but that a 'radiation annealing' effect is observed. A system-level description is provided, including Fresnel lens and phase ...
2003-06-01
British Library Electronic Table of Contents (United Kingdom)
Abstract Juvenile cobia (Rachycentron canadum) (100-g) were fed four moist diets (447-476-g-kg-1-dry-wt) where 0, 130, 260 or 390-g-kg-1 of concentrated lizardfish (Saurida undosquamis) silage replaced fresh lizardfish, respectively. Blood and livers were sampled at 0, 6, 12, 24 and 48-h postfeeding at the end of the 3-week experiment. At 6-h postfeeding in all groups, maximum concentrations of most plasma essential amino acids were observed, while significantly lower levels of most non-essential amino acid levels were recorded compared to the other sampled times. At 6 and 12-h after feeding, the concentration of most plasma free amino acid (FAA) increased with an increase in dietary fish silage levels. Most FAA in livers of all groups peaked at 12 and 24-h postfeeding. However, at 48-h po...
2011-01-01
International Nuclear Information System (INIS)
The local density functional theory is used to study the electrical levels and thermal stabilities of complexes of interstitial boron with O and C and a boron dimer with H. The energy levels of these defects are compared with those found from deep level transient capacitance spectroscopy experiments on irradiated p-Si containing B. The levels observed at E_c-0.23, E_v+0.29, and E_v+0.51 eV are assigned to B_iO_i, B_iC_s, and B_iB_sH_i respectively. B_iC_s is passivated by one H atom. Evidence for the existence of B_iC_s has implications for mechanisms involved in the suppression of transient-enhanced diffusion of boron in ion-implanted Si by C.
2003-07-28
Ferroelectric and magnetic properties of Ho{sub 2}CuTiO{sub 6} double perovskite
Energy Technology Data Exchange (ETDEWEB)
Ho{sub 2}CuTiO{sub 6} double pervoskite is synthesized by solid state reaction method and the phase formation was confirmed by X-ray diffraction. Ho{sub 2}CuTiO{sub 6} crystallizes in space group P63 cm and are isostructural in AMnO{sub 3} structure. We have investigated the effect of the presence of a magnetic ion (Ho{sup 3+}{approx}10.4{mu}{sub B}) in Ho{sub 2}CuTiO{sub 6}, on the magnetic properties, compared to that of an isostructural double perovskite containing Y-ion (non-magnetic), i.e., Y{sub 2}CuTiO{sub 6}. Magnetization measurements on Ho{sub 2}CuTiO{sub 6} showed paramagnetic moment of 0.026{mu}{sub B}/Ho at room temperature in an applied field of 7 T although no saturation is observed at room temperature, whereas, at 5 K, the paramagnetic moment was 0.3{mu}{sub B}/Ho in the same field. Since this compound is non-centrosymmetric, it is of interest to look into the possibility of realizing multiferroicity (coexistence of magnetic and ...
2006-08-15
Energy Technology Data Exchange (ETDEWEB)
The PERMCAT process chosen for the final clean-up stage of the Tokamak Exhaust Processing system of the ITER tritium plant combines in a single component a catalytic reactor and a permeator using Pd/Ag membranes. This study covers the mechanical behaviour of a Pd/Ag membrane under different operating conditions. The consequences of hydrogen uptake by the membrane during nominal operation but also during off-normal events are presented. Depending on the operating conditions, expansions around 2% and significant deformations are observed. Different mechanical designs of PERMCAT reactors are then discussed. The first generation comprises finger-type membranes and two new mechanical designs use either additional edge welded bellows or a special corrugated Pd/Ag membrane. These upgraded designs improve the robustness and simplify the geometry of the component. The experimental validation of these new units has been carried out based on the measurements of the processing ...
2007-10-15
International Nuclear Information System (INIS)
The PERMCAT process chosen for the final clean-up stage of the Tokamak Exhaust Processing system of the ITER tritium plant combines in a single component a catalytic reactor and a permeator using Pd/Ag membranes. This study covers the mechanical behaviour of a Pd/Ag membrane under different operating conditions. The consequences of hydrogen uptake by the membrane during nominal operation but also during off-normal events are presented. Depending on the operating conditions, expansions around 2% and significant deformations are observed. Different mechanical designs of PERMCAT reactors are then discussed. The first generation comprises finger-type membranes and two new mechanical designs use either additional edge welded bellows or a special corrugated Pd/Ag membrane. These upgraded designs improve the robustness and simplify the geometry of the component. The experimental validation of these new units has been carried out based on the measurements of the processing ...
2007-10-01
Energy Technology Data Exchange (ETDEWEB)
An experimental study of forced convection heat transfer at the inner tube wall of a double pipe heat exchanger with coiled wire inserts as heat transfer augmentation devices was performed over a turbulent flow region. The test results from twelve augmented tubes with inserts of different combinations of wire diameters (0.813, 1.016 and 1.575 mm) and pitches (2.82, 3.63, 5.08 and 8.47 mm) indicate that the turbulence promoters studied improve heat transfer by a factor of 1.4 to 2.24 compared with a smooth tube, although at a cost of 10-30 times increase in friction factor. A formula for presenting dimensionless exergy losses in a tubular heat exchanger is derived first and then the thermohydrodynamic optimum instead of economic optimum is found by minimizing the exergy losses in the system. From the heat transfer improvement number defined, it is observed that coiled wire turbulence promoters are more effective at Reynolds numbers less than ...
1992-12-01
Experimental investigation on the fretting wear of alloy 800 in room remperature water
Energy Technology Data Exchange (ETDEWEB)
Fretting wear test in room temperature water was performed to evaluate the wear coefficient of CANDU (CANadian Deuterium Uranium) steam generator (SG) tube material (Alloy 800) against 410 type martensitic stainless steels. The main focus is to compare the wear behaviors between Alloy 800 and Inconel 690. Test conditions are 10{approx}30N of normal load, 200{approx}450mm of sliding amplitude and 30Hz of frequency. The result indicated that the wear rate of Alloy 800 was higher than those of Inconel 690 at various test condition such as normal loads, sliding amplitudes etc. From the results of SEM observation, there was little evidence of plastic deformation layer that were dominantly formed on the worn surfaces of Inconel 690. Also, wear particles in Alloy 800 were released from contacting asperities deformed by severe plastic flow during fretting wear. Main cause of wear rate between Alloy 800 and Inconel 690 may be due to the difference of ...
2002-05-01
Experimental investigation on the fretting wear of alloy 800 in room remperature water
International Nuclear Information System (INIS)
Fretting wear test in room temperature water was performed to evaluate the wear coefficient of CANDU (CANadian Deuterium Uranium) steam generator (SG) tube material (Alloy 800) against 410 type martensitic stainless steels. The main focus is to compare the wear behaviors between Alloy 800 and Inconel 690. Test conditions are 10#approx#30N of normal load, 200#approx#450mm of sliding amplitude and 30Hz of frequency. The result indicated that the wear rate of Alloy 800 was higher than those of Inconel 690 at various test condition such as normal loads, sliding amplitudes etc. From the results of SEM observation, there was little evidence of plastic deformation layer that were dominantly formed on the worn surfaces of Inconel 690. Also, wear particles in Alloy 800 were released from contacting asperities deformed by severe plastic flow during fretting wear. Main cause of wear rate between Alloy 800 and Inconel 690 may be due to the difference of ...
2002-05-01
Evaluation of heat exchange rate of GHE in geothermal heat pump systems
Energy Technology Data Exchange (ETDEWEB)
Total thermal resistance of ground heat exchanger (GHE) is comprised of that of the soil and inside the borehole. The thermal resistance of soil can be calculated using the linear source theory and cylindrical source theory, while that inside the borehole is more complicated due to the integrated resistance of fluid convection, and the conduction through pipe and grout. Present study evaluates heat exchange rate per depth of GHE by calculating the total thermal resistance, and compares different methods to analyze their similarities and differences for engineering applications. The effects of seven separate factors, running time, shank spacing, depth of borehole, velocity in the pipe, thermal conductivity of grout, inlet temperature and soil type, on the thermal resistance and heat exchange rate are analyzed. Experimental data from several real geothermal heat pump (GHP) applications in Shanghai are used to validate the present calculations. The ...
2009-12-15
Energy Technology Data Exchange (ETDEWEB)
Live cores were obtained from five reservoirs using special precautions to prevent contamination by exogenous microorganisms and minimize exposure to oxygen. The depths from which the cores were obtained ranged from 2,705 ft to 6,568 ft. Core plugs were cut radially from live cores, encased in heat-shrink plastic tubes, placed in core holders, and fitted with inlets and outlets. Nutrient additions stimulated the in-situ microbial population to increase, dissolve stratal material, produce gases, and release oil. Reduction in flow through the core plugs was observed in some cases, while in other cases flow was increased, probably due to the dissolution of carbonates in the formation. A field demonstration of the ability of the in-situ microbial population to increase oil recovery by blocking the more permeable zones of the reservoir is currently underway. This demonstration is being conducted in the North Blowhorn Creek Unit situated in Lamar County, Alabama. Live ...
1995-12-31
Electron momentum spectroscopy of H_2 and D_2: Ionization to ground and excited final states
International Nuclear Information System (INIS)
The symmetric noncoplanar (e,2e) cross sections (momentum profiles) of H_2 and D_2 for the transitions to the 2p#sigma#_u and 2s#sigma#_g excited ion states have been measured, relative to the ground-state ion transition, using a high-sensitivity multichannel momentum-dispersive electron momentum spectrometer (EMS) at an impact energy of 1200 eV. Newly calculated plane-wave impulse approximation (PWIA) cross sections, based on a full-configuration-interaction H_2 wave function, are compared to the experimental results. These calculations are in better agreement with the experimental results for the transition to the 2s#sigma#_g ion state than the earlier theoretical work of Liu and Smith, Jr. [Phys. Rev. A 31, 3003 (1985)] which has been found to be in error. Nevertheless, significant discrepancies between the relative experimental and theoretical cross sections are observed for the transitions to excited ion states, suggesting a failure of the ...
Effects of Thermal Annealing Upon the Nanomorphology of Poly(3-hexylselenophene)-PCBM Blends
British Library Electronic Table of Contents (United Kingdom)
Abstract Grazing incidence X-ray diffraction (GI-XRD) is used to characterize the crystallographic dynamics of low molecular weight (LMW) and high molecular weight (HMW) poly(3-hexylselenophene) (P3HS) films and blend films of P3HS with [6-6-]-phenyl-C61-butyric acid methyl ester (PCBM) as a function of -step-by-step- thermal annealing, from room temperature to 250-C. The temperature-dependent GIXRD data show how the melting point of P3HS crystallites is decreased by the presence of PCBM. P3HS crystallite domain sizes dramatically increase upon annealing to the P3HS melting temperature. The formation of well-oriented HMW P3HS crystallites with the (100) plane parallel to the substrate (edge-on orientation), when cooled from melt, are observed. We compare the behaviour of P3HS pure and blen...
2011-01-01
International Nuclear Information System (INIS)
Salinisation of freshwater has been identified as a serious environmental issue in Australia and around the world. Protective concentrations (trigger values) for salinity can be used to manage salinity impacts, though require locally relevant salinity tolerance information. 72-h acute salinity tolerance values were determined for 102 macroinvertebrates collected from 11 locations in four biologically distinct freshwater bio-regions in Northeast Australia and compared with sensitivities observed in Southeast Australia. The salinity tolerance of individual taxa was consistent across Northeast Australia and between Northeast and Southeast Australia. However, two distinct communities were identified in Northeast Australia using distributions of the acute tolerance values and a calculated index of salinity sensitivity. Salinity trigger values should therefore be representative of local or regionally relevant communities and may be adequately ...
2008-02-01
Effect of pressure on iodine complexes, 2
International Nuclear Information System (INIS)
Absorption spectra of the CT bands of I_2 complexes with Et_2O, Et_2S, and Et_2Se in heptane have been measured up to 4400 bar at 25"0C. The equilibrium constants and the volume changes accompanying complex formation, and the molar extinction coefficients and absorption maxima have been estimated. The volume changes were comparable with those estimated by the visible I_2 bands and by the X-ray data of the I_2 complexes in the crystalline state. In the CT bands of Et_2S-I_2 and Et_2Se-I_2 complexes inversion of shift from red to blue has been observed with increasing pressure though the CT band of Et_2O-I_2 complex shifted only through red. This inversion appears to be characteristic of the strong CT complex. Enhancement of the molar extinction coefficient of the CT band has been found with increasing pressure suggesting enhancement of the CT interaction between I_2 and the n-donor. (author).
1979-01-01
International Nuclear Information System (INIS)
The effect of mean stress, or the stress ratio (R), on the fatigue-crack growth (FCG) behavior of #alpha#-aged and #omega#-aged microstructures of the beta titanium alloy Ti-10V-2Fe-3Al was investigated. While the mean stress had a negligible effect on the FCG behavior of the #alpha#-aged microstructure, a strong effect was observed in the #omega#-aged microstructure. In particular, the values of the threshold stress-intensity range (#DELTA#K_t_h) exhibited a strong dependence on R in the #omega#-aged microstructure, while this dependence was weak in the #alpha#-aged microstructure. These effects seem to arise primarily from fracture-surface roughness-induced crack closure. The crack closure levels for the #alpha#-aged microstructure were found to be very low compared to those for the #omega#-aged microstructure. Transmission electron microscopy and scanning electron microscopy studies of microstructures and fracture surfaces were performed to ...
2000-03-01
Effect of grain size on engineering properties of coal ash
Energy Technology Data Exchange (ETDEWEB)
The main object of the present study was to obtain the relationship of primary, secondary and index properties; compressibility; and angle of repose of coal ash. Representative samples of coal ash from different storage locations of Ropar thermal power plant, Punjab, were analysed. Based on test results of various primary characteristics of ash, the following observations have been made. (1) Ashes sampled for the study have a common mineralogical origin. The uniformity coefficient increases for ash collected near location of discharge compared to ash collected far from the location. (2) The void ratio extent, that is, a different of emax. or a ratio of emax. and emin. decreases with an increase of mean size. The maximum dry density obtained in dry vibration and proctor test differs for fine ash. Maximum dry density decreases and optimum moisture content increases with increase in mean size. Permeability of ash at proctor density is more, ...
2003-07-01
Effect of Li-Al co-doping on the energy gaps of MgB2
International Nuclear Information System (INIS)
We studied the effects of co-doping with Li and Al on the energy gaps of MgB2 by performing point-contact Andreev-reflection spectroscopy (PCAR) in polycrystalline Mg1-x(Al?Li1-?)xB2 samples with x?0.4. Even though the lattice parameters and the critical temperature of the compound simply scale with the effective Al content ?x, irrespective of the Li concentration, the energy gaps do not. In particular, for a given effective Al content, the comparison with Mg1-y(Al)yB2 with y = ?x shows that the ? bandgap is practically the same while the ? bandgap is higher. A clear gap merging is observed in the most doped sample (x = 0.4) when Tc<20 K. The results are discussed within the two-band Eliashberg theory and compared to the outcomes of first-principles calculations of the effects of Li and Al co-doping on the electronic structure of magnesium diboride.
2009-02-01
Dynamic Batch Bayesian Optimization
Bayesian optimization (BO) algorithms try to optimize an unknown function that is expensive to evaluate using minimum number of evaluations/experiments. Most of the proposed algorithms in BO are sequential, where only one experiment is selected at each iteration. This method can be time inefficient when each experiment takes a long time and more than one experiment can be ran concurrently. On the other hand, requesting a fix-sized batch of experiments at each iteration causes performance inefficiency in BO compared to the sequential policies. In this paper, we present an algorithm that asks a batch of experiments at each time step t where the batch size p_t is dynamically determined in each step. Our algorithm is based on the observation that the sequence of experiments selected by the sequential policy can sometimes be almost independent from each other. Our algorithm identifies such scenarios and request those experiments at the same time ...
2011-01-01
Distribution of activation energies for impurity hopping in amorphous metals
Energy Technology Data Exchange (ETDEWEB)
The distribution of activation energies ..delta.. for classical over-the-barrier hopping is computed for a model amorphous metal. The spread in ..delta.. is determined by the variation in equilibrium-site and saddle-point sizes for the assumed model of dense random packing (DRP) of soft spheres. The size distribution is related to the radial distribution function in a manner which reproduces recent numerical results for the interstitials in DRP models. Size (distance) variation in general is related to energy variation by the form of the potential energy V(r). We show, however, that the distribution of equilibrium-site energies can be related directly to the impurity-induced lattice expansion and bulk modulus without detailed knowledge of V(r). The form of V(r) is necessary for the saddle-point distribution, and we estimate this using simple analytic expressions which fit the observed lattice expansion and impurity (hydrogen) vibrational frequency. The effects of a ...
1983-02-15
Energy Technology Data Exchange (ETDEWEB)
The usual method of introducing engineers to the concept of dislocations and their role in plastic flow is to compare an estimate of the theoretical strength of solid (of order {micro}/30 where {micro} is the shear modulus) and the observed strength of either single crystals ({mu}/10{sup 4}) or practical engineering material such as structural steels where the yield stress in shear is of order {mu}/10{sup 3}. However, if one considers the problem in reverse, one can consider the accumulation of dislocations as an important mechanism by which one can produce engineering materials in which the strength level approaches the theoretical strength. If one assumes that the flow stress can be expressed in terms of te mean free path between stored dislocations or as the square root of the global dislocation density, then one can see the influence of dislocation density in a diagrammatic form. It is clear that the strengthening by dislocation ...
1999-04-01
Differential pressure measurement using a free-flying insect-like ornithopter with an MEMS sensor
International Nuclear Information System (INIS)
This paper presents direct measurements of the aerodynamic forces on the wing of a free-flying, insect-like ornithopter that was modeled on a hawk moth (Manduca sexta). A micro differential pressure sensor was fabricated with micro electro mechanical systems (MEMS) technology and attached to the wing of the ornithopter. The sensor chip was less than 0.1% of the wing area. The mass of the sensor chip was 2.0 mg, which was less than 1% of the wing mass. Thus, the sensor was both small and light in comparison with the wing, resulting in a measurement system that had a minimal impact on the aerodynamics of the wing. With this sensor, the 'pressure coefficient' of the ornithopter wing was measured during both steady airflow and actual free flight. The maximum pressure coefficient observed for steady airflow conditions was 1.4 at an angle of attack of 30"0. In flapping flight, the coefficient was around 2.0 for angles of attack that ranged from 25"0 to 40"0. Therefore, a ...
2010-09-01
Energy Technology Data Exchange (ETDEWEB)
Diagnostic capability of Fuji Computed Radiography (FCR) of the chest was compared to the conventional radiography (CoR) using regular film-screen system. FCR utilizers imaging plates of scanning laser stimulated luminescence. Visibility of 14 structures of the chest radiography was evaluated by 3 radiologists in 100 pairs of FCR and CoR which were taken at the same time with the same exposure factors. FCR was superior to CoR especially in observation of the mediastinum and areas behind the heart and diaphragm. The minor fissure was better seen on CoR. Superiority of FCR to CoR was thought to be mainly due to the processed image of FCR, and the so-called normal image of FCR had little diagnostic advantage. Simulated abnormal densities: nodular, alveolar, and interstitial densities with a chest phantom, were made, and detectability of alteration of these densities on FCR and CoR was evaluated by 19 radiologists, using ROC curve analysis. FCR and ...
1989-02-01
International Nuclear Information System (INIS)
Diagnostic capability of Fuji Computed Radiography (FCR) of the chest was compared to the conventional radiography (CoR) using regular film-screen system. FCR utilizers imaging plates of scanning laser stimulated luminescence. Visibility of 14 structures of the chest radiography was evaluated by 3 radiologists in 100 pairs of FCR and CoR which were taken at the same time with the same exposure factors. FCR was superior to CoR especially in observation of the mediastinum and areas behind the heart and diaphragm. The minor fissure was better seen on CoR. Superiority of FCR to CoR was thought to be mainly due to the processed image of FCR, and the so-called normal image of FCR had little diagnostic advantage. Simulated abnormal densities: nodular, alveolar, and interstitial densities with a chest phantom, were made, and detectability of alteration of these densities on FCR and CoR was evaluated by 19 radiologists, using ROC curve analysis. FCR and ...
1989-01-01
Development of a methodology to assess the climate evolution and its impacts on wind energy
International Nuclear Information System (INIS)
Maps of wind resources were used to develop a method of evaluating climatic changes and their potential impacts on wind energy resources. Global IPCC climate change scenarios were used to predict climatic conditions for the future, while past wind resource availability was simulated and validated using NCEP and NCAR reanalysis data as well as observed meteorological data from Environment Canada. The simulations were used to compare each 5-year period with a 50-year reference period. Regional scale climate change impacts were evaluated using a statistical dynamic down-scaling method. Advanced meteorological models were used to predict wind flow patterns across specific landscapes. The evolution of past wind resource availability was then simulated. Five-year wind resource simulations for a 50-year period were simulated at 25 km"2 wind speeds at 80 m above the ground. Average wind speed variations were then evaluated. The method has been used to ...
2010-11-01
Energy Technology Data Exchange (ETDEWEB)
A new method is being developed to quickly screen for the human exposure potential to polycyclic aromatic hydrocarbons (PAHs) and organochlorines (OCs). The development involves two key elements: identifying suitable signals that represent intracellular changes that are specific to PAH and OC exposure, and constructing a device to guide the biological cell growth so that signals from individual cells are consistent and reproducible. We are completing the identification of suitable signals by using synchrotron radiation-based (SR) Fourier-transform infrared (FTIR) spectromicroscopy in the mid-infrared region (4000-400 cm-1). Distinct changes have been observed in the IR spectra after treatment of human cells in culture medium with PAHs and OCs. The potential use of this method for detecting exposure to PAHs and OCs has been tested and compared to a reverse transcription polymerase chain reaction (RT-PCR) assay that quantifies increased ...
1999-01-10
Energy Technology Data Exchange (ETDEWEB)
This research involves the development of an analysis which yielded recommendations regarding the plate thickness at which the effects of transverse shear become significant enough to be taken into consideration during vibration testing of composite plates. The specimens designed using this analysis are to be used for the {open_quotes}inverse{close_quotes} problem of determining through-the-thickness elastic constants as well as in-plane elastic constants from modal vibration response data. The effects of transverse shear were studied over the range of practical plate aspect ratios (length to thickness ratios) and mode numbers. Behavior of composite plates ranging from isotropic to highly orthotropic was studied in order to investigate the effects of transverse shear. Orthotropic plates having in-plane dimensions of 254 x 254 mm and thicknesses varying from 10 mm to 80 mm, with free-free edge boundary conditions, were considered. A methodology was developed to use Finite Element ...
1997-12-31
Crystallization fouling of calcium sulfate dihydrate on heat-transfer surfaces
Energy Technology Data Exchange (ETDEWEB)
The present paper deals with the fouling process of calcium sulfate dehydrate on heat-transfer surfaces. The crystallization of calcium sulfate showed typical asymptotic fouling curves, the asymptotic value of which was greatly influenced by the surface temperature and fluid velocity. The fouling mechanism was discussed with a generalized fouling model and proved to be surface process controlled, where the activation energy was 6.2 {times} 10{sup 4} J/mol. The availability of mechanical cleaning against the formed scale was quantitatively evaluated by applying the particle abrasion method. The removal test verified that the removing rate per unit particle concentration decreased in an inverse proportion to the overall particle load, to the power of 0.8, and that it was affected by the fluid velocity. The observed final residual fouling resistance decreased asymptotically with an increase in particle concentration. The suitable concentration of the abrasive ...
1996-02-01
International Nuclear Information System (INIS)
We report a study of the physical characteristics of the pillars of C, Pt and W grown by 10-30 keV Ga focused ion beam (FIB) as a function of Ga ion flux, and present a quantitative analysis of the elements using energy-dispersive analysis of X-rays (EDAX). All the FIB grown pillars exhibit a rough morphology with whisker like protrusions on the cylindrical surface and broadening of the base as compared to the nominal size. For a constant fluence, the height of the pillar initially increases and then reduces after going through a maximum as a function of ion flux in all the cases. The compositional analysis shows good metallic quality for Pt structures but reveals significant contamination of Ga in C and Ga and C in W structures at higher ion fluxes. Explanation to all these observations has been sought in the light of secondary ion and electron effects and the different processes involved which lead to the FIB induced deposition.
2008-04-01
Computer modeling of oil spill trajectories with a high accuracy method
Energy Technology Data Exchange (ETDEWEB)
This paper proposes a high accuracy numerical method to model oil spill trajectories using a particle-tracking algorithm. The Euler method, used to calculate oil trajectories, can give adequate solutions in most open ocean applications. However, this method may not predict accurate particle trajectories in certain highly non-uniform velocity fields near coastal zones or in river problems. Simple numerical experiments show that the Euler method may also introduce artificial numerical dispersion that could lead to overestimation of spill areas. This article proposes a fourth-order Runge-Kutta method with fourth-order velocity interpolation to calculate oil trajectories that minimise these problems. The algorithm is implemented in the OilTrack model to predict oil trajectories following the 'Nissos Amorgos' oil spill accident that occurred in the Gulf of Venezuela in 1997. Despite lack of adequate field information, model results compare well with ...
1999-07-01
International Nuclear Information System (INIS)
The difference of NH_4"+-N/NO_3"--N nutrition between hybrid and conventional rice varieties at the late growth stage was studied by using "1"5N-tracer technique. The results showed that the nitrate fertilizer utilization efficiency by the hybrid rice after anthesis was 7.8% higher than that by the ordinary rice variety, and the nitrate fertilizer recovery fraction by the former was 13.2% greater than that by the latter. The varietal difference in NO_3"--N uptake and utilization was almost twice as that in NH_4"+-N. It was also showed that "1"5N distribution in ear of the hybrid rice was about 20% greater than that of the conventional variety, but there were no obvious differences between NO_3"--N and NH_4"+-N. However, "1"5N distribution in the lower node leaves and root was found to be significant higher with NO_3"--N than that with NH_4"+-N in both rice varieties, particularly in the hybrid rice. Compared with NH_4"+-N, NO_3"--N top-dressing before anthesis was ...
British Library Electronic Table of Contents (United Kingdom)
Soils of arid regions of Central Asia contain salts of different types that may differentially affect seed germination and plant development. We studied effect of NaCl, Na2SO4, 2NaCl + KCl + CaCl2 and 2Na2SO4+K2SO4+MgSO4 on germination of Kochia prostrata and Kochia scoparia seeds under a range of concentrations from 0.5 to 5% and at two constant temperature regimes +22 degrees C and +6 degrees C. The observed salt tolerance limit of germination at constant temperature +22 degrees C for both species was 5-6%, while at low temperature (+6 degrees C) this limit was 2%. The salt tolerance of young plants (before flowering) was 3% for NaCl. Low concentrations of sulfuric and mixed salts had a stimulating effect on seed germination in K. prostrata. Despite similarity of salt-tolerance limits...
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
To attain reproducible and stable contacts to compound semiconductor devices, it is necessary to achieve thermodynamically stable phases after the reaction of metals with the compound semiconductor. In this study, the final phases produced by the reactions between GaAs and thin metal films of Co, Rh, Ir, Ni, Pd, and Pt have been investigated. They are identified as MGa for M = Co, Rh, Ni, Pd, and Pt, monoarsenides of Co and Ni, diarsenides of Rh, Ir, Pd, and Pt, and Ir/sub 3/Ga/sub 5/. These phases, if deposited directly onto GaAs, will produce thermally stable contacts. In addition to the identification of these stable phases, analyses of the products of thin-film M/GaAs reactions by transmission electron microscopy, x-ray diffraction, and Rutherford backscattering spectrometry reveal the distribution, grain size, and crystallographic texture of these end phases. Trends in these observations across the six metal/GaAs reactions studied are explained by considering ...
1987-09-01
Coherent transport of matter waves in disordered optical potentials
Energy Technology Data Exchange (ETDEWEB)
The development of modern techniques for the cooling and the manipulation of atoms in recent years, and the possibility to create Bose-Einstein condensates and degenerate Fermi gases and to load them into regular optical lattices or disordered optical potentials, has evoked new interest for the disorder-induced localization of ultra-cold atoms. This work studies the transport properties of matter waves in disordered optical potentials, which are also known as speckle potentials. The effect of correlated disorder on localization is first studied numerically in the framework of the Anderson model. The relevant transport parameters in the configuration average over many different realizations of the speckle potential are then determined analytically, using self-consistent diagrammatic perturbation techniques. This allows to make predictions for a possible experimental observation of coherent transport phenomena for cold atoms in speckle potentials. Of particular ...
2007-07-01
Energy Technology Data Exchange (ETDEWEB)
To evaluate the diagnostic accuracy of Fuji computed radiography (FCR) in the detection of interstitial pulmonary infiltrates, FCR life-size images at a pixel size of 0.1 mm were compared with conventional radiographs taken on the same day. Seventeen radiologists assessed the radiographs and FCR images of 56 cases, including 39 cases of various interstitial lung diseases such as interstitial pneumonia, pulmonary abnormalities associated with collagen disease, sarcoidosis, multiple pulmonary metastases, diffuse panbronchiolitis and pulmonary emphysema, and 17 normal controls. All of the pulmonary abnormalities were confirmed by high resolution CT. Observer performance tests were carried out using receiver operating characteristic analysis. In 21 cases of increased pulmonary density revealed by high resolution CT, FCR was significantly superior to conventional radiographs in the detection of reticular or linear shadows. In 11 cases of subtle ...
1991-11-01
International Nuclear Information System (INIS)
To evaluate the diagnostic accuracy of Fuji computed radiography (FCR) in the detection of interstitial pulmonary infiltrates, FCR life-size images at a pixel size of 0.1 mm were compared with conventional radiographs taken on the same day. Seventeen radiologists assessed the radiographs and FCR images of 56 cases, including 39 cases of various interstitial lung diseases such as interstitial pneumonia, pulmonary abnormalities associated with collagen disease, sarcoidosis, multiple pulmonary metastases, diffuse panbronchiolitis and pulmonary emphysema, and 17 normal controls. All of the pulmonary abnormalities were confirmed by high resolution CT. Observer performance tests were carried out using receiver operating characteristic analysis. In 21 cases of increased pulmonary density revealed by high resolution CT, FCR was significantly superior to conventional radiographs in the detection of reticular or linear shadows. In 11 cases of subtle ...
1991-01-01
Energy Technology Data Exchange (ETDEWEB)
The purpose of this study is to prevent the deactivation of catalysts recycled in the 0.1 t/d bench scale unit (BSU). Catalysts recovered during reactions in the BSU and after reactions in the 5-liter autoclave were analyzed, to investigate the influences of the reaction condition on the property and activity of catalysts. Were used {gamma}-iron oxyhydroxide ({gamma}-FeOOH), {alpha}-iron oxyhydroxide ({alpha}-FeOOH), and natural pyrite (FeS2) as catalysts. At the S/Fe atomic ration of 1.2 under the BSU reaction condition, troilite was more easily formed from {gamma}-FeOOH compared with pyrite and {alpha}-FeOOH. As the reaction proceeded through the first, second, and third reactors, the crystal size increased, the pyrrhotite content decreased, and the troilite content increased. Deactivation due to the formation of troilite was irreversible. At the S/Fe of 3.0, however, both the formation of troilite and the crystal growth of pyrrhotite were not ...
1996-10-28
Energy Technology Data Exchange (ETDEWEB)
Simultaneous reduction of NO{sub x} and particulate emissions in a direct-injection diesel engine has been realized experimentally with a high squish combustion chamber. The purpose of this study is to investigate the effects of high squish combustion chamber on combustion process in detail. Engine CFD code FREC was used for the analysis. The results show the followings. (1) Compared with standard toroidal chamber, high squish chamber generates high turbulence due to strong squish and large expansion flow is caused in the cavity. (2) Rich and high-turbulence combustion, which forms ring area in the cavity under squish lip, continues during the combustion. (3) The high squish combustion chamber keeps fuel long in the cavity and less hid spreads out to the cold clearance volume. (4) For the condition of retarded injection timing, the effect of high squish is mainly observed at initial combustion and high swirl is more effective at diffusion ...
1999-08-25
Energy Technology Data Exchange (ETDEWEB)
This paper investigated the effect of hydrogen (H{sub 2}) addition on the combustion process of a heavy-duty diesel engine. The addition of a small amount of H{sub 2} was shown to have a mild effect on the cylinder pressure and combustion process. When operated at high load, the addition of a relatively large amount of H{sub 2} substantially increased the peak cylinder pressure and the peak heat release rate. Compared to the two-stage combustion process of diesel engines, a featured three-stage combustion process of the H{sub 2}-diesel dual fuel engine was observed. The extremely high peak heat release rate represented a combination of diesel diffusion combustion and the premixed combustion of H{sub 2} consumed by multiple turbulent flames, which substantially enhanced the combustion process of H{sub 2}-diesel dual fuel engine. However, the addition of a relatively large amount of H{sub 2} at low load did not change the two-stage heat release ...
2010-10-15
British Library Electronic Table of Contents (United Kingdom)
One method of increasing juvenile fish escapement from net cod-ends is to encourage fish to approach the netting by placing an active stimulating device (ASD) in the cod-end. Two types of ASD were tested inside model cod-ends to generate variable visual stimuli. One was a free-end flag-like net panel and the other consisted of an array of free-ended ropes. Escape responses of juvenile red seabream were observed in a circulating water channel using a cod-end fitted with the ASD, and they were compared with responses to conventional polyethylene multi-ply, high-contrast cod-ends with and without ASD made from either 28- or 43-mm mesh under three light conditions. With the ASD attached, the retention rate was significantly lower, 20%, than for conventional cod-ends except in dim light with 28...
2010-01-01
Activation of Polymethyl-Methacrylate by Proton Beam
International Nuclear Information System (INIS)
Activation has been used for many kinds of useful applications, such as use of the radioisotopes for diagnosis and treatment of cancer, and wear (or corrosion) investigation for using thin layer activation (TLA) technique, etc. But activation also has severe problems for the post-processing of the samples; such as time-loss, inconvenience of sample handling, personal radiation safety, etc. For in-vitro experiments, we observed death of tumor cells by proton irradiation. The use of large activated container material can cause erroneous results in this case. To solve these problems, we studied why the samples were activated and how the level of the activation could be reduced. In proton beam irradiation experiments, the target materials could be defined as the container and sample itself. We could easily reduce activation of container material comparing to activation of sample itself. Therefore, we tried to find less activated container material ...
2010-10-01
The giant alga Chara corallina generates action potentials (APs) in response to mechanical stimulation, injury, or direct electrical stimulation. Students examine the waveform characteristics of these APs using standard intracellular recording techniques. Intracellular recording is easier than with neurons because of the large size of the Chara cell. Students observe very negative resting potentials (up to -250 mV), large AP amplitudes with depolarizing peaks approaching 0 mV, AP durations of seconds, and refractory periods up to several minutes. Students calculate Nernst potentials for the ions distributed across the Chara cell membrane to hypothesize the ions responsible for the resting potential and for the depolarizing phase of the AP. These calculations suggest that K+ is responsible for the resting potential and that Ca2+ influx and Ca2+-activated Cl- efflux are responsible for depolarizing phases of the AP, which they are. Comparison of the Chara AP ...
2008-06-11
Energy Technology Data Exchange (ETDEWEB)
Negative ion electrospray ionization (ESI) coupled with high field Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) allows for the direct detection of acidic NSO compounds in petroleum. The technique requires no chromatographic separation, is able to distinguish 18 different compound classes (e.g., neutral nitrogen, carboxylic acids and oxygenates), and can identify {approx}14,000 distinct masses by ultra-high mass resolution and mass accuracy. We previously studied three crude oils from different geological origins [Organic Geochemistry 33 (2002b) 743-759]. Here, we expand our research by comparing two source-equivalent Smackover oils of different levels of thermal maturity. We observe clear differences in the distribution of NSO compound classes, types (number of rings plus double bonds within a class), and number of alkyl carbons. With increasing thermal stress, the relative amount of sulfur and oxygen containing ...
2004-07-01
Abundances of Jupiter's Trace Hydrocarbons From Voyager and Cassini
The flybys of Jupiter by the Voyager spacecraft in 1979, and over two decades later by Cassini in 2000, have provided us with unique datasets from two different epochs, allowing the investigation of seasonal change in the atmosphere. In this paper we model zonal averages of thermal infrared spectra from the two instruments, Voyager 1 IRIS and Cassini CIRS, to retrieve the vertical and meridional profiles of temperature, and the abundances of the two minor hydrocarbons, acetylene (C2H2) and ethane (C2H6). The spatial variation of these gases is controlled by both chemistry and dynamics, and therefore their observed distribution gives us an insight into both processes. We find that the two gases paint quite different pictures of seasonal change. Whilst the 2-D cross-section of C2H6 abundance is slightly increased and more symmetric in 2000 (northern summer solstice) compared to 1979 (northern fall equinox), the major trend of equator to pole ...
2010-01-01
Absorption of the atmospheric CO{sub 2} by oceanic biota near the air-sea interface
Energy Technology Data Exchange (ETDEWEB)
The oceanic phytoplancton productivity may essentially influence the total rate of the atmospheric CO{sub 2} absorption by the ocean - that is, a considerable amount of CO{sub 2} will be taken-up in the 50 micrometers thick layer near the air-sea interface. Even if phytoplancton production constitutes only 5% of the total oceanic biota production, this will increase the rate of CO{sub 2} absorption more than twice compared with the present estimates. The reason is that metabolic activity of phytoplancton leads to the emergence in a thin scin (50 micrometers, the average size of phytoplancton cells) layer near the water surface of an additional minimum in the CO{sub 2} partial pressure profile and of an additional maximum of {Delta} {sup 13}C in the same area. These two extremums cannot be detected if the corresponding characteristics are averaged over any microscopic area in the well mixing layer that is more than 1 meter deep, which is usually the case when the ...
1997-12-31
API 5L X80M OD 34 inches cold bending
Energy Technology Data Exchange (ETDEWEB)
One of the main factors that require special attention in a pipeline construction is the cold bending process, once depending on the region that the line will be installed the number of bends may achieve 75%, as it was observed in some areas during Campinas-Rio pipeline construction. A study was carried out to evaluate the X80 cold bending operational parameters in order to make viable the use of high strength pipes in the construction of onshore pipelines. For this analysis three pipes of 34 inches x 0.750 inches had been cold bended, the operation was carried out using a hydraulic equipment with punches applications along the pipe, recording the correspondent angles related to the elastic and plastic deformations in order to assess the material spring-back. After the bending process, samples of the weld, extrados and intrados were subjected to mechanical and metallographic tests, as well as performed dimensional inspection of the pipes. It was possible to obtain ...
2009-07-01
A sensitive submillimetre survey of Broad Absorption Line quasars
Using the SCUBA bolometer array on the JCMT, we have carried out a submillimetre survey of Broad Absorption Line quasars (BALQs). The sample has been chosen to match, in redshift and optical luminosity, an existing benchmark 850um sample of radio-quiet quasars, allowing a direct comparison of the submm properties of BAL quasars relative to the parent radio-quiet population. We reach a submm limit 1.5mJy at 850um, allowing a more rigorous measure of the submm properties of BAL quasars than previous studies. Our submm photometry complements extensive observations at other wavelengths, in particular X-rays with Chandra and mid-infrared with Spitzer. To compare the 850um flux distribution of BALQs with that of the non-BAL quasar benchmark sample, we employ a suite of statistical methods, including survival analysis and a novel Bayesian derivation of the underlying flux distribution. Although there are no strong grounds for rejecting the null ...
2006-01-01
A quantitative structural analysis of the low temperature phase of lithium-7
International Nuclear Information System (INIS)
Calculations in "7Li have been carried out for the differential coherent elastic scattering cross-section of thermal neutrons at a fixed scattering angle #theta#_0(148"o) and varying the energy of incident neutrons (or corresponding d-spacings). The results are reported, as variations of the ratio #SIGMA#_0"c"o"h (#theta#_0, d)/#SIGMA#_0"c"o"h (#theta#_0) with d-spacing, at atmospheric pressure and at two temperatures, 80 and 20 K. The calculations at 80 K correspond to BCC lithium whereas at 20 K all the possible crystallographic structures of polytype lithium (BCC, 9R, HCP and FCC) were considered. On comparing our results with the time-of-flight (TOF) measurements of Berliner et al. (Physical Review, B40, 12086, 1989) we find that up to 80 K lithium-7 does not undergo any martenistic transformation whereas the structural state at 20 K can be described by the co-existence of the original BCC phase with 9R, HCP and FCC closed packed structures. A quantitative ...
A Wide-Band Electromagnetic Impedance Profiling System forNon-Invasive Subsurface Characterization
Energy Technology Data Exchange (ETDEWEB)
A non-invasive, wide-band electromagnetic (EM) impedance difference system for shallow subsurface electrical structure characterization in environmental and engineering problems has been developed at the Lawrence Berkeley National Laboratory (LBNL). Electrical parameters of interest are electrical conductivity and dielectric permittivity that are deduced from the impedance difference data. The prototype system includes a magnetic loop transmitter, which operates between 0.1 MHz and 100 MHz, an electrical dipole antenna for observing the electric field, and a loop antenna for measuring the magnetic field.All antennas are mounted on a cart made of non-metallic material for easy movement of the whole array for profiling. Surface EM impedance difference is obtained by taking the difference of the ratios of the electric fields to the magnetic fields at selected frequencies at two different levels. Numerical simulations will be presented to verify this new approach. A ...
2004-12-17
A reactor-neutrino experiment, Daya Bay, has been proposed to determine the least-known neutrino mixing angle theta_13 using electron antineutrinos produced at the Daya Bay nuclear power complex in China. Daya Bay is an international collaboration with institutions from China, the United States, the Czech Republic, Hong Kong, Russia, and Taiwan. The experiment will use eight identical detectors deployed at three different locations optimized for monitoring the antineutrino rates from the six reactors and for detecting any rate deficit and spectral distortion near the first oscillation maximum. The overburden of the under ground experimental halls, connected with tunnels, ranges from about 250 to 900 meters-water-equivalent so that the cosmogenic background is small compared to the number of observed antineutrino events. Civil construction of tunnels and experimental facilities is planned to start in 2007, with detector construction beginning in ...
2007-01-01
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