Search results for "Semiconductor"
showing 10 items of 974 documents
Detection of Partial Discharges at Square Shaped Voltages
2018
Due to the wide use of electronic converters and the introduction of new powerful power electronics devices, the input waveforms most often used are becoming much different than the traditional power frequent sinusoidal one. In High Voltage (HV) apparatus particularly, this condition can increase the stress on the insulation systems that may lower the reliability of the whole power grid. This type of input voltage, often showing an increased voltage gradient, causes problems in the Partial Discharge (PD) measurement setup and acquisition systems, also due to the increased harmonic content. In this paper, the main aim is to discuss how to suitably approach the measurement technique of PDs at…
A Simple Model for Ac Impedance Spectra in Bipolar Membranes
1996
A new model accounting for the ac impedance spectra of synthetic ion-exchange bipolar membranes is presented. The theoretical approach is based on the Nernst−Planck and Poisson equations and applies some of the concepts used in the semiconductor pn junctions to the case of a bipolar membrane. The results presented are the current−voltage curves and the impedance spectra at electric currents above the limiting current. It is shown that the model is able to identify the main contributions to the bipolar membrane impedance and gives valuable information about the bipolar junction structure and its influence on the characteristic parameters involved in the field-enhanced water dissociation phen…
A block access unit for 2D memory access
2007
Many of the coding tools in the H.264/AVC video coding standard are based on 2D processing resulting in rowwise and column-wise memory accesses starting from arbitrary memory addresses. This paper discusses a low-cost hardware realization of these accesses on sub-word parallel processors. The proposed block access unit is placed between the processor and memory. It supports unaligned 2D block accesses according to several 2D access patterns. The 2D block accesses are pipelinable and they result in minimum number of memory accesses required to deliver the desired data.
Analyzing the Energy Efficiency of the Memory Subsystem in Multicore Processors
2014
In this paper we analyze the energy overhead incurred when operating with data stored in different levels of the memory subsystem (cache levels and DDR chips) of current multicore architectures. Our approach builds upon servet, a portable framework for the memory characterization of multicore processors, extending this suite with a power-related test that, when applied to a platform equipped with a power measurement mechanism, provides information on the efficiency of memory energy usage. As additional contributions, i) we provide a complete experimental study of the impact that the CPU performance states (also known as P-states) exert on the memory energy efficiency of a collection of rece…
Insights into archaeological human sample microbiome using 16S rRNA gene sequencing
2017
Human body is inhabited by a vast number of microorganisms, collectively known as human microbiome, and there is a tremendous interest in evolutionary changes of human microbial ecology, diversity and function. The field of paleomicrobiology – study of ancient human microbiome – is powered by modern techniques of Next Generation Sequencing (NGS), which allows extracting microbial genomic data directly from archaeological sample of interest. One of the major techniques is 16S rRNA gene sequencing, by which certain 16S rRNA gene hypervariable regions are being amplified and sequenced. However, some limitations of this method exist including taxonomic precision and efficacy of different region…
Ultralow thermal conductivity in 1D and 2D imidazolium-based lead halide perovskites
2021
Low-dimensional hybrid organic–inorganic metal halide perovskites are rapidly emerging as a fascinating sub-class of the three-dimensional parent structures, thanks to their appealing charge and thermal transport properties, paired to better chemical and thermal stabilities. Extensive investigations of the thermal behavior in these systems are of paramount relevance to understand their optoelectronic and thermoelectric applications. Herein, we present a complete thermophysical characterization of imidazolium lead iodide, (IMI)PbI3, a 1D pseudo-perovskite with chains of face-sharing octahedra, and histammonium lead iodide, (HIST)PbI4, a 2D layered perovskite with corner-sharing octahedra. Up…
German-Wide Interlaboratory Study Compares Consistency, Accuracy and Reproducibility of Whole-Genome Short Read Sequencing.
2020
We compared the consistency, accuracy and reproducibility of next-generation short read sequencing between ten laboratories involved in food safety (research institutes, state laboratories, universities and companies) from Germany and Austria. Participants were asked to sequence six DNA samples of three bacterial species (Campylobacter jejuni, Listeria monocytogenes and Salmonella enterica) in duplicate, according to their routine in-house sequencing protocol. Four different types of Illumina sequencing platforms (MiSeq, NextSeq, iSeq, NovaSeq) and one Ion Torrent sequencing instrument (S5) were involved in the study. Sequence quality parameters were determined for all data sets and central…
Compositional and Optical Gradient in Films of PbZrxTi1-xO3 (PZT) Family
2011
Pb(ZrxTi1-x)O3 (PZT) (x = 0-1) films have attracted the attention of researchers for the past 30 years due to their excellent ferroelectric (FE) and electromechanical properties, which have led to the commercialization of thin PZT films for ferroelectric random access memory (FeRAM), forming a market of several millions USD annually. Ferroelectricity of perovskite oxide thin films, especially PZT thin films, can be exploited in semiconductor devices to achieve non-volatile random access memory (NVRAM) with high-speed access and long endurance, which can overcome the barriers, encountered in current semiconductor memory technologies. The ferroelectricity can be also exploited to voltage depe…
Devices based on semiconductor nanowires
2009
Recently, nanoelectromechanical systems (NEMS) have attracted much attention due to their unique properties and possible applications that differ greatly from those of microelectromechanical systems. NEMS operating frequencies may achieve giga- and terahertz levels and their power consumption and heat capacity is extremely low. Moreover, integration levels may reach 1012 devices per cm−2. In this review, we present techniques for integrating semiconductor materials in NEMS. In particular, we examine fabrication, structure, properties and potential applications of two main classes of NEMS, namely, resonators and switches.
Evidence of Magnetoresistance in the Prussian Blue Lattice during a Voltammetric Scan
2008
This manuscript reports evidence of magnetoresistance effects in the Prussian Blue lattice during a voltammetric scan at room temperature. Accordingly, the PB is a well-known semiconductor that becomes surprisingly an almost metallic conductor in the presence of an internal magnetic field induced during the voltammetric scan. This offers appealing perspectives for the control of this interesting phenomenon from electrochemical techniques that could be used for the fabrication of the recent phase-change computational memories, which are electronically configurable. Herein, the PB magnetic properties have been monitored in situ by means of resonating magnetic microsensors based on the shift i…