533 research outputs found
Effect of Electron Beam Irradiation on Structural, Electrical and Thermo-electric Power of La0.8Sr0.2MnO3
In this communication, we are reporting the effect of electron beam (e-beam) irradiation on thermoelectric
properties of La0.8Sr0.2MnO3 manganites. The samples were prepared using solid state reaction technique.
It is observed that the lattice volume increases with increase in dosage of e-beam. With irradiation
an increase in resistivity is observed. For small irradiation dosage, we first observe a decreases in metalinsulator
transition temperature TMI; thereafter TMI increases with further increase in dosage of irradiation.
Both, the resistivity data and thermo-electric power data demonstrate that small polaron hopping
model is valid in high temperature region
Effect of Electron Beam Irradiation on Structural, Electrical and Thermo-electric Power of La0.8Sr0.2MnO3
In this communication, we are reporting the effect of electron beam (e-beam) irradiation on thermoelectric
properties of La0.8Sr0.2MnO3 manganites. The samples were prepared using solid state reaction technique.
It is observed that the lattice volume increases with increase in dosage of e-beam. With irradiation
an increase in resistivity is observed. For small irradiation dosage, we first observe a decreases in metalinsulator
transition temperature TMI; thereafter TMI increases with further increase in dosage of irradiation.
Both, the resistivity data and thermo-electric power data demonstrate that small polaron hopping
model is valid in high temperature region
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Advanced Power Plant Development and Analyses Methodologies
Under the sponsorship of the U.S. Department of Energy/National Energy Technology Laboratory, a multi-disciplinary team led by the Advanced Power and Energy Program of the University of California at Irvine is defining the system engineering issues associated with the integration of key components and subsystems into advanced power plant systems with goals of achieving high efficiency and minimized environmental impact while using fossil fuels. These power plant concepts include ''Zero Emission'' power plants and the ''FutureGen'' H{sub 2} co-production facilities. The study is broken down into three phases. Phase 1 of this study consisted of utilizing advanced technologies that are expected to be available in the ''Vision 21'' time frame such as mega scale fuel cell based hybrids. Phase 2 includes current state-of-the-art technologies and those expected to be deployed in the nearer term such as advanced gas turbines and high temperature membranes for separating gas species and advanced gasifier concepts. Phase 3 includes identification of gas turbine based cycles and engine configurations suitable to coal-based gasification applications and the conceptualization of the balance of plant technology, heat integration, and the bottoming cycle for analysis in a future study. Also included in Phase 3 is the task of acquiring/providing turbo-machinery in order to gather turbo-charger performance data that may be used to verify simulation models as well as establishing system design constraints. The results of these various investigations will serve as a guide for the U. S. Department of Energy in identifying the research areas and technologies that warrant further support
Synthesis And Characterization Of Co-Doped SnO2/TiO2 Semiconductor Nano Crystallites Via Sol-Gel Method
SnO2/TiO2 nano particles are novel wide band gap semiconductors with modified applications of SnO2 and TiO2 in some fields including gas sensing, photo catalytic, solar cells and so on. The Co-doped SnO2/TiO2 nano particles were obtained via sol-gel method with different amounts of doping material as 2.5 %, 6 % and 10 mol %. The crystallite sizes of resulting material were from 3.8 nm for 0.1 wt % Co-doped SnO2/TiO2 to 19.1 nm for un-doped. Morphology and nanostructure of the crystalline SnO2/TiO2 nano particles were characterized by means of X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), Thermal gravimetric analysis (TGA), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDX). It has been shown that fine semiconductor nano structures were formed.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/933
Pregnancy associated plasma protein-A (PAPP-A) as an early marker for the diagnosis of acute coronary syndrome.
Aims and objectives
Pregnancy associated plasma protein-A (PAPP-A), a metalloproteinase plays a pivotal role in the pathogenesis of atherosclerosis. Recent studies have reported that elevated levels of PAPP-A, signal the onset of acute coronary syndrome (ACS). We, therefore, proposed to study the analytical competence of PAPP-A in patients admitted to the emergency department with chest pain and finally diagnosed as ACS.
Methods and results
Pregnancy associated plasma protein-A was measured using enzyme-linked immunosorbent assay (ELISA) in 485 patients admitted to emergency care unit, of which 89 patients were diagnosed as Non-cardiac chest pain (NCCP). Elevated levels of PAPP-A were observed in patients diagnosed as ACS on comparison with the controls. Receiver operator characteristic (ROC) curve analysis showed PAPP-A to be a good discriminator between ischaemic and non-ischaemic patients. The area under the curve was found to be 0.904, 95% CI (0.874–0.929) with 90% sensitivity and 85% specificity (P< 0.0001). The cut-off value from the ROC curve was 0.55 μg/mL above which PAPP-A was considered to be positive.
Conclusion
Pregnancy associated plasma protein-A seems to be a promising biomarker for identification and risk stratification for patients with ACS
A Simple Sol Gel Protocol Towards Synthesis Of Semiconducting Oxide Nanomaterial
Nanostructured Tin oxide (SnO2), powders was synthesized by employing a novel Sol-gel protocol at RT. A wide variety of techniques such as energy – dispersive spectroscopy(EDX), N2 sorption, X-ray diffraction (XRD), have been used to study the formation process and characterization of the nanoparticles obtained. Transmission electron microscopy (TEM) has been applied to find out about the shape and size distribution of the particles. The nanoparticles thus synthesized were monodispersed, with an average particle size of ~ 10 nm and spherical in shape. The EDX analysis revealed the presence of Sn, O signal in the synthesized nanoparticles confirming the purity of the synthesized samples. This protocol appears promising for application in large-scale synthesis of nanoparticles.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/933
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Vision 21 Systems Analysis Methodologies Annual Report
Under the sponsorship of the U.S. Department of Energy/National Energy Technology Laboratory, a multi-disciplinary team led by the Advanced Power and Energy Program of the University of California at Irvine is defining the system engineering issues associated with the integration of key components and subsystems into power plant systems that meet performance and emission goals of the Vision 21 program. The study efforts have narrowed down the myriad of fuel processing, power generation, and emission control technologies to selected scenarios that identify those combinations having the potential to achieve the Vision 21 program goals of high efficiency and minimized environmental impact while using fossil fuels. The technology levels considered are based on projected technical and manufacturing advances being made in industry and on advances identified in current and future government supported research. Included in these advanced systems are solid oxide fuel cells and advanced cycle gas turbines. The results of this investigation will serve as a guide for the U. S. Department of Energy in identifying the research areas and technologies that warrant further support
Battery Aware Dynamic Scheduling for Periodic Task Graphs
Battery lifetime is a primary design constraint for mobile embedded systems. It has been shown to depend heavily on the load current profile (i.e. evolution of the current drawn over time). However, up to now, very few low-power scheduling policies take this fact into account. We explore how scheduling guidelines drawn from battery models can help in the extension of battery capacity. We proposed a 'Battery-Aware Scheduling' methodology for periodically arriving task-graphs (Directed Acyclic Graph) with real time deadlines and precedence constraints. The methodology presented divides the problem into two steps. First, a good DVS algorithms dynamically determines the minimum frequency of execution. Then, a greedy algorithm allows a near optimal priority function to choose the task which would maximize slack recovery. Battery simulations carried out on the profile generated by our approach for a large set of task-graphs show that battery life time is extended up to 23.3% compared to existing dynamic scheduling schemes
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