3,493 research outputs found

    Reliability of GaN-on-Si high-electron-mobility transistors for power electronics application

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    Wireless Sensor Integrated Tool for Characterization of Machining Dynamics in Milling

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    A first step towards practical sensing in the machining environment is the development and use of low cost, reliable sensors. Historically, the ability to record in-process data at an end mill tool tip has been limited by the sensor location. Often, these sensors are mounted on the material workpiece or the machine spindle at significant physical distance from the cutting process. Of specific interest are the problems of tool chatter which causes limitations to productivity and part quality. Although tool chatter is a substantial issue in machining, it remains an open research topic. In this research, a sensor integrated cutting tool holder is developed to specifically analyze the problems related to tool chatter. With the sensor integrated cutting tool holder, the signal to noise ratio is higher than traditional sensing methods. Because of the higher sensitivity, new data analysis methods can be explored. Specifically, the sensor is used in conjunction with a data dependent linear predictive coding algorithm to demonstrate effective prediction of chatter frequencies from stable cutting

    Advanced photonic and electronic systems WILGA 2018

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    WILGA annual symposium on advanced photonic and electronic systems has been organized by young scientist for young scientists since two decades. It traditionally gathers around 400 young researchers and their tutors. Ph.D students and graduates present their recent achievements during well attended oral sessions. Wilga is a very good digest of Ph.D. works carried out at technical universities in electronics and photonics, as well as information sciences throughout Poland and some neighboring countries. Publishing patronage over Wilga keep Elektronika technical journal by SEP, IJET and Proceedings of SPIE. The latter world editorial series publishes annually more than 200 papers from Wilga. Wilga 2018 was the XLII edition of this meeting. The following topical tracks were distinguished: photonics, electronics, information technologies and system research. The article is a digest of some chosen works presented during Wilga 2018 symposium. WILGA 2017 works were published in Proc. SPIE vol.10445. WILGA 2018 works were published in Proc. SPIE vol.10808

    Photonic skin based on polymer embedding of optical sensors and interrogation units

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    JRA3 Electromagnetic Calorimeter Technical Design Report

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    This report describes the design of the prototype for an Silicon Tungsten electromagnetic calorimeter with unprecedented high granularity to be operated in a detector at the International Linear Collider (ILC). The R&D for the prototype is co-funded by the European Union in the FP6 framework within the so called EUDET project in the years 2006-2010. The dimensions of the prototype are similar to those envisaged for the final detector. Already at this stage the prototype features a highly compact design. The sensitive layers, the Very Front End Electronics serving 64 channels per ASIC and copper plates for heat draining are integrated within 2000 μm

    The ALICE TPC, a large 3-dimensional tracking device with fast readout for ultra-high multiplicity events

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    The design, construction, and commissioning of the ALICE Time-Projection Chamber (TPC) is described. It is the main device for pattern recognition, tracking, and identification of charged particles in the ALICE experiment at the CERN LHC. The TPC is cylindrical in shape with a volume close to 90 m^3 and is operated in a 0.5 T solenoidal magnetic field parallel to its axis. In this paper we describe in detail the design considerations for this detector for operation in the extreme multiplicity environment of central Pb--Pb collisions at LHC energy. The implementation of the resulting requirements into hardware (field cage, read-out chambers, electronics), infrastructure (gas and cooling system, laser-calibration system), and software led to many technical innovations which are described along with a presentation of all the major components of the detector, as currently realized. We also report on the performance achieved after completion of the first round of stand-alone calibration runs and demonstrate results close to those specified in the TPC Technical Design Report.Comment: 55 pages, 82 figure

    Radiation Test Challenges for Scaled Commerical Memories

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    As sub-100nm CMOS technologies gather interest, the radiation effects performance of these technologies provide a significant challenge. In this talk, we shall discuss the radiation testing challenges as related to commercial memory devices. The focus will be on complex test and failure modes emerging in state-of-the-art Flash non-volatile memories (NVMs) and synchronous dynamic random access memories (SDRAMs), which are volatile. Due to their very high bit density, these device types are highly desirable for use in the natural space environment. In this presentation, we shall discuss these devices with emphasis on considerations for test and qualification methods required

    Conductive Trace Design in 3-D Circuit Architectures: Heat Transfer Analysis and Experiments

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    Recent research efforts have been devoted to developing technologies for fabricating electronic circuits in three dimensions using ink-jet processes. The management of generated heat in such circuits will require them to incorporate specialized design features for promoting the removal of unwanted heat from key areas and the limiting of component temperatures to safe levels. Hence, effective tools for predicting the heat transfer characteristics of three-dimensional circuits are required to develop optimum designs.This research encompasses a course of investigation including the development of such design tools and their verification using experimental methods. These experimental methods consisted of thermal tests conducted with prototype circuits constructed in three dimensions, with materials appropriate to the overarching design concept. After the verification process, the investigation proceeded with the construction of numerical models to compare a range of design features expected to enhance passive heat rejection in the discrete resistive component. The relative impact of each of these structures as well as the impact of specific material choices is comparatively evaluated using the developed tools.Further research centered on the fabrication and testing of a circuit which more fully incorporated the 3-D architecture by employing a surface-mount technology (SMT) resistor and by embedding the resistor and conductive components within a cast polymer matrix. Experiments with this circuit and corresponding finite-element models showed that for the power dissipation levels investigated, the presence of the embedding medium actually results in lower temperatures at the resistive component.It was shown in the course of this latter investigation that film coefficients calculated by standard methods do not effectively account for interactions between adjacent convective surfaces in these circuit architectures. A numerical model featuring thermal/fluid dynamics capability and simplified geometry compared to the actual circuit was shown to correlate well with live tests. These model results can be used to calculate improved values for the film coefficients to be applied to models not featuring fluid capability. The models with improved film coefficients similarly provided resistor temperature values which correlated well with the live test results
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