35 research outputs found
Fresh Fuel Characterization of U-Mo Alloys
The need to provide more accurate property information on U-Mo fuel alloys to reactor operators, modelers, researchers, fabricators, and regulators increases as success of the RERTR program continues. This presentation will provide an overview of fresh fuel U-Mo characterization activities on monolithic fuel occurring at the Idaho National Laboratory. The overview will particularly be focused on properties available through current and previous research, and also on the type of information still needed. The presentation will deal with mechanical, physical, and microstructural properties in terms of both integrated and separate effects. Appropriate discussion in terms of fabrication characteristics, impurities, thermodynamic response, and the effects on the topic areas will be provided, along with a brief background on the characterization techniques being used or being developed to obtain the information. Furthermore, efforts to measure similar characteristics as a function of irradiation conditions and determine end-of-life observations with beginning-of-life behavior will be discussed
Update on Fresh Fuel Characterization of U-Mo Alloys
The need to provide more accurate property information on U-Mo fuel alloys to operators, modellers, researchers, fabricators, and government increases as success of the GTRI Reactor Convert program continues. This presentation provides an update on fresh fuel characterization activities that have occurred at the INL since the RERTR 2008 conference in Washington, D.C. The update is particularly focused on properties recently obtained and on the development progress of new measurement techniques. Furthermore, areas where useful and necessary information is still lacking is discussed. The update deals with mechanical, physical, and microstructural properties for both integrated and separate effects. Appropriate discussion of fabrication characteristics, impurities, thermodynamic response, and effects on the topic areas are provided, along with a background on the characterization techniques used and developed to obtain the information. Efforts to measure similar characteristics on irradiated fuel plates are discussed
Renin, endothelial no synthase and endothelin gene expression in the 2Kidney-1clip goldblatt model of long-term renovascular hypertension
<p>Abstract</p> <p>Objective</p> <p>Numerous reports have shown the influence of renin, nitric oxide (NO) and the endothelin (ET) systems for regulation of blood pressure and renal function. Furthermore, interactions between these peptides have been reported. Aim of our study was to investigate the relative contribution of these compounds in long-term renovascular hypertension/renal ischemia.</p> <p>Methods</p> <p>Hypertension/left-sided renal ischemia was induced using the 2K1C-Goldblatt rat model. Renal renin, ET-1, ET-3 and endothelial NO synthase (eNOS) gene expression was measured by means of RNAse protection assay at different timepoints up to 10 weeks after induction of renal artery stenosis.</p> <p>Results</p> <p>Plasma renin activity and renal renin gene expression in the left kidney were increased in the clipped animals while eNOS expression was unchanged. Furthermore, an increase in ET-1 expression and a decrease of ET-3 expression was detected in early stenosis.</p> <p>Conclusions</p> <p>While renin is obviously involved in regulation of blood pressure and renal function in unilateral renal artery stenosis, ET-1, ET-3 and endothelium derived NO do not appear to play an important role in renal adaptation processes in long-term renal artery stenosis, although ET-1 and ET-3 might be involved in short-term adaptation processes.</p
Wideband, modular Diver Detection Sonar (DDS)
The complete protection of naval harbours, port approaches and anchorages requires the underwater continuous monitoring and threat detection such as divers, their delivery vehicles or AUVs from safe distances. R&D Marine Technology Centre (CTM) has began designing and building of the new generation, modular, wideband Diver Detection Sonar (DDS), based on cylindrical multielement piezocomposite transducer made by Materials Systems Inc. (Littleton, USA). The paper describes key features of the DDS technology demonstrator and specific technological principles of the sonar construction. The first DDS harbour trials are planned take place during May 2010
SHL-101/T SONAR - results of the harbour and sea trials
The safeguard of seaways, naval basis, harbours and sea frontiers from minefields, attackers, gun-running is essential in hazardous nowadays. Particularly modern sea mines sometimes buried and make in stealth technology are very difficult to detect. Therefore the echo-ranging detection systems require state-of-the-art hardware and efficient processing algorithms to protect sea areas. Such up-to-date hydroacoustic equipment was developed by R&D Marine Technology Centre. The SHL-101/T system is the triple frequency, wideband and very high resolution hull-mounted minehunting sonar. It was put into service to Polish Navy minesweeper on April 2007. Sonar underwent factory, harbour and sea acceptance trials. Presently Polish Navy carries out further exploitation and military tests. The results are remarkable and they enable to explore mysteries of the sunken objects in the Gdansk Gulf. The paper presents the results of SHL-101/T sonar harbour and sea trials. Its performances for different detection and classification modes are also depicted. Additionally displays of the found various underwater objects are included and detailed discussed
Simulation of the time - spatial filtration algorithm by 2d FFT expanded method and its properties
The article presents the simulation results of the time-spatial matched filtration algorithm in detail described in [1]. The features of the algorithm are presented on figures of the realized simulations. Firstly, the simulation results in case of jar field are described. Successively the realizability of different filtrations types within algorithms is presented. Next the possibility of the algorithm adaptation to nearfield is shown. The last of the presented properties are possibilities of the directions of arrival choice
Machine Learning-Based Predictions of Customers’ Decisions in Car Insurance
Predicting customer decisions allows companies to obtain higher profits due to better resource management. The accuracy of those predictions can be currently boosted by the application of machine learning algorithms. We propose a new method to predict a car driver’s decision about taking a replacement car after a vehicle accident happens. We use feature engineering to create attributes of high significance. The generated attributes are related to time (e.g., school holidays), place of collision (e.g., distance from home), time and conditions (e.g., weather), vehicles (e.g., vehicle value), addresses of both the victim and the perpetrator. Feature engineering involves external sources of data. Five machine learning methods of classification are considered: decision trees, multi-layer perceptrons, AdaBoost, logistic regression and gradient boosting. Algorithms are tested on real data from a Polish insurance company. Over 80% accuracy of prediction is achieved. Significance of the attributes is calculated using the linear vector quantization method. Presented work shows the applicability of machine learning in the car insurance market
Thermotransport In Γ(Bcc) U-Zr Alloys: A Phase-Field Model Study
Atomic transport in the presence of a temperature gradient, commonly known as thermotransport or the thermomigration phenomenon, was simulated for U-Zr alloys using a phase-field model derived from irreversible thermodynamics. The free energy of the U-Zr system, a necessary ingredient for the phase-field-model, was directly incorporated from the available thermodynamic database. Kinetic parameters such as atomic mobility and heat of transport terms were obtained from experimental values reported in the literature. The model was applied to a single-phase (bcc-γ phase) alloy and to a diffusion couple consisting of two single-phase (bcc-γ phase) alloys of different compositions, both subjected to a constant temperature gradient. Constituent redistribution in the absence and presence of a compositional gradient was examined. An enrichment of Zr with a corresponding depletion of U was observed at the hot end of the initially homogeneous single-phase alloy. A similar atomic transport behavior was observed in the diffusion couple, where the magnitude and direction of the final composition gradient was dictated by the combined influence of atomic mobility and heat of transport terms. © 2010 Elsevier B.V. All rights reserved
Impurity migration and effects on vacancy formation enthalpy in polycrystalline depleted uranium
We have used Doppler-broadening of the positron-electron annihilation radiation technique and VASP calculations to verify the previously reported vacancy formation enthalpy Hvf in polycrystalline depleted uranium. Experimentally we have confirmed a Hvf of (1.6 ± 0.2) eV. VASP calculations using GGA and LDA approximations gave vacancy formation enthalpies values of 1.98 eV and 2.22 eV respectively. We found residual oxygen in the sample diminished these values by 50% or more. Our new experimental and theoretical data supports the notion that oxygen impurities in the sample are responsible for lower values of vacancy formation enthalpies. Measured and calculated vacancy formation enthalpies, as well as the obtained oxygen migration enthalpy of (0.6 ± 0.1) eV, are compared and discussed with values reported in the literature.Fil: Lund, K. R.. Washington State University; Estados UnidosFil: Lynn, K. G.. Washington State University; Estados UnidosFil: Weber, M. H.. Washington State University; Estados UnidosFil: Macchi, Carlos Eugenio. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires. - Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires; ArgentinaFil: Somoza, Alberto Horacio. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires. - Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires; ArgentinaFil: Juan, Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Física del Sur. Universidad Nacional del Sur. Departamento de Física. Instituto de Física del Sur; ArgentinaFil: Okuniewski, M. A.. Idaho National Laboratory; Estados Unido