Search results for "conversion"
showing 10 items of 707 documents
Genetic basis of human complement C4A deficiency. Detection of a point mutation leading to nonexpression.
1993
Abstract The fourth component of the human complement system (C4) is coded for by two genes, C4A and C4B, located within the MHC. Null alleles of C4 (C4Q0) are defined by the absence of C4 protein in plasma. These null alleles are due either to large gene deletions or to nonexpression of the respective genes. In a previous study, evidence was obtained for nonexpressed defective genes at the C4A locus, and for gene conversion at the C4B locus. To further characterize the molecular basis of these non-expressed C4A genes, we selected nine pairs of PCR primers from flanking genomic intron sequences to amplify all 41 exons from individuals with a defective C4A gene. The amplified products were s…
Synthesis and characterization of zinc carboxy–porphyrin complexes for dye sensitized solar cells
2018
Two zinc porphyrins, 2 and 8, have been synthesized. Porphyrin 8 displays better electronic communication between the dye and the TiO2 electrode. Photophysical measurements and electrochemistry experiments suggest that both porphyrins are very promising sensitizers for dye-sensitized solar cells (DSSCs). It was found that their molecular orbital energy levels favor electron injection and dye regeneration in DSSCs. Solar cells sensitized by 2 and 8 were fabricated, and it was found that they show power conversion efficiencies (PCEs) of 5.27% and 7.13%, respectively. Photovoltaic measurements (J–V curves) together with the incident photon-to-electron conversion efficiency spectra of the two c…
Design, assembly and characterization of silicide-based thermoelectric modules
2016
ID: 1143 In: Energy conversion and management, 13-21. Summary: Highlights•Novel silicide-based thermoelectric modules were experimentally investigated.•The modules produced high power of 1.04 W at 405 °C and 3.24 W at 735 °C.•An estimated module efficiency of 5.3% represent the highest reported for silicide systems.AbstractSilicides have attracted considerable attention for use in thermoelectric generators due mainly to low cost, low toxicity and light weight, in contrast to conventional materials such as bismuth and lead telluride. Most reported work has focused on optimizing the materials properties while little has been done on module testing. In this work we have designed and tested mod…
Online optimization of a multi-conversion-level DC home microgrid for system efficiency enhancement
2017
In this paper, an on-line management system for the optimal efficiency operation of a multi-bus DC home distribution system is proposed. The operation of the system is discussed with reference to a distribution system with two conversion stages and three voltage levels. In each of the conversion stages, three paralleled DC/DC converters are implemented. A Genetic Algorithm performs the on-line optimization of the DC network’s global efficiency, generating the optimal current sharing ratios of the concurrent power converters. The overall DC/DC conversion system including the optimization section is modelled using MATLAB/Simulink. Thanks to the implemented online algorithm, considering …
A microcontroller-based portable electrocardiograph recorder.
2004
We describe a low cost portable Holler design that can be implemented with off-the-shelf components. The recorder is battery powered and includes a graphical display and keyboard. The recorder is capable of acquiring up to 48 hours of continuous electrocardiogram data at a sample rate of up to 250 Hz.
Sustainability of the Renewable Energy Extraction Close to the Mediterranean Islands
2017
The aim of this work is to explore the possibility of transitioning a fuel powered island to a renewable powered one. This transition is analyzed for the real MV/LV distribution system of the island of Pantelleria, in the Mediterranean Sea. Particularly, this work is focused on a renewable source nowadays totally unused: wave energy. Thanks to the innovative generator prototype designed by Department of Energy of University of Palermo (Italy), wave energy is able to represent a primary source for the production of electric energy in the Mediterranean islands. The procedures applied in the present article, as well as the main equations used, are the result of previous applications made in di…
On the Efficacy of PCM to Shave Peak Temperature of Crystalline Photovoltaic Panels: An FDM Model and Field Validation
2013
The exploitation of renewable energy sources and specifically photovoltaic (PV) devices have been showing significant growth; however, for a more effective development of this technology it is essential to have higher energy conversion performances. PV producers often declare a higher efficiency respect to real conditions and this deviation is mainly due to the difference between nominal and real temperature conditions of the PV. In order to improve the solar cell energy conversion efficiency many authors have proposed a methodology to keep the temperature of a PV system lower: a modified crystalline PV system built with a normal PV panel coupled with a Phase Change Material (PCM) heat stor…
Quasi-digital conversion for resistive devices: application in GMR-based IC current sensors
2013
Resistive devices, including sensors, are used in a huge range of applications within different scenarios. When a complete system is considered, a quasi-digital output is often recommendable. If the conversion is operated at device level, some problems such as noise disturbs, insertion losses and so on, can be reduced. In this work, we describe a resistance-tofrequency (R-f) converter with a suggested application in low current monitoring by means of GiantMagnetoResistance (GMR) sensors. Specific devices have been designed and microfabricated. The system has been tested by means of discrete components with a PCB. The complete microsystem monolithic integration in a standard CMOS technology …
The European DEMO fusion reactor: Design status and challenges from balance of plant point of view
2017
DEMO initial conceptual design studies are being conducted in Europe as part of the European Union Roadmap to Fusion Electricity, which aims to demonstrate the feasibility of electricity produced by nuclear fusion reactors around the middle of this century. The aim of this paper is to provide an overview of the DEMO project, highlighting its main characteristics and challenges in terms of design, integration, and operation. Particular emphasis is given on some important systems of the Balance of Plant (BoP), such as the primary heat transfer systems, the related power conversion systems, and the electrical power plant. The relevance of such systems is due to the need of a continuous reanaly…
A multiphysics approach to the design of a seawave energy conversion system
2008
This paper presents a multiphysics approach to the design of a seawave energy conversion system which consists of a both a permanent magnet linear generator directly coupled to sea waves and the related power electronics conversion system. The thermal, electromagnetic and circuital aspects are included in the proposed approach. In order to maximize energy extraction, the stochastic features of the energy source is considered in the mathematical model of the whole system. An optimization procedures which includes the stochastic features of the model is presented and a machine built on the basis of the results of this procedure is shown.