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Distributed Generation (DG) has an important role regarding the quality of power of distribution networks. It can impact in many ways such as the improvement of reliability and the voltage quality levels of the network. This paper is an extension of a previous work, which proposes a methodology, allocating generators from different sizes and technologies in distribution networks, in order to assess...
Physiological and anatomical changes with age in the ear, nose, and throat have long been the subject of clinical interest; increasingly, they are the subject of basic and clinical investigations [1–7]. Nonetheless, the role of alterations in cells and tissues and distinctions among genetic, pathological, environmental, and interactive effects on cellular, tissue, and organ function are still emerging...
This paper presents a methodology and a computational tool developed for the assessment of the impacts caused by photovoltaic and wind generators, up to 100 kW, connected to the distribution networks, and aims at a real network application. The impact on the power distribution systems planning derive from the new network configuration caused by the installation of distributed generators and the demand...
We present an R&D program to develop an ASIC that contains a 12-channel VCSEL (Vertical Cavity Surface Emitting Laser) array driver operating at 10 Gb/s per channel, yielding an aggregated bandwidth of 120 Gb/s. The design of the 10 Gb/s array driver ASIC is based on a prototype ASIC for driving a VCSEL array at 5 Gb/s. We will briefly describe the design of the 5 Gb/s ASIC that was fabricated...
The Large Hadron Collider at CERN is presently in a two year shutdown for upgrades. Among the upgrades include insertion of a new detector in the ATLAS experiment called the Diamond Beam Monitor. Included in the DBM is a radiation hard application specific integrated circuit, the Hitbus chip platform, to allow the DBM to trigger its own readout. Intellectual property (IP) from several collaborating...
We have recently developed a circuit theory based method to analyze large CMUT arrays and shown that mutual acoustic interactions significantly influence the transducer performance. We connect each cell in the array to a radiation impedance matrix that contains the mutual radiation impedance between every pair of cells, in addition to their self radiation impedances. However, efficient analysis of...
In this study, an equivalent electrical circuit model for a single circular CMUT in both uncollapsed and collapsed modes is obtained. In order to model the collapsed mode mechanics, the governing differential equation is solved semi-analytically for a large number of normalized cases. Then the calculations are adapted to the equivalent electrical circuit model. The model uses the self radiation impedance...
This paper presents a methodology that defines the most suitable configurations to allocate reclosers in power distribution networks. The methodology is composed by two stages. At the first stage, optimal configurations to install reclosers in each feeder are established, considering the improvement promoted in continuity indexes. Each configuration corresponds to a previously fixed number of reclosers...
This paper discusses the connection of photovoltaic system, including microgrids formation, in power distribution networks. The proposed model integrates the descriptive elements of a photovoltaic system: solar radiation, typical load behaviors (residential, commercial and industrial). Based on the developed methodology, a computer implementation of the modules for simulation and impact analysis of...
This paper presents a methodology for assessment of the impacts on the distribution network faced with the presence of electric vehicles (EV) and aims at its application in the distribution networks of two power utilities in Brazil. The impact on the electrical system is originated by the loads on the network, which are represented by particular and typical load curves associated to consumers, and...
A very accurate equivalent circuit model for circular CMUT cell is recently proposed. As a consequence of this model, the operating characteristics of the cell is derived and presented as a biasing chart for CMUTs. We discuss these operating characteristics and show how the coupling coefficient can be derived from the model. We present an analysis of receiver performance of a CMUT cell. We also demonstrate...
We present a design method for airborne capacitive micromachined ultrasonic transducers (CMUT). We use an equivalent lumped element circuit to model both electrical and mechanical properties of CMUT and analyze it in frequency domain using harmonic balance approach. We use this method to design CMUTs for large transmitted power generation at low drive voltage amplitude. We determine the dimensions...
We have designed an ASIC for use in a parallel optical engine for a new layer of the ATLAS pixel detector in the initial phase of the LHC luminosity upgrade. The ASIC is a 12-channel VCSEL (Vertical Cavity Surface Emitting Laser) array driver capable of operating up to 5 Gb/s per channel. The ASIC is designed using a 130 nm CMOS process to enhance the radiation-hardness. A scheme for redundancy has...
An equivalent electrical circuit model valid for collapsed mode operation of CMUT is described. The across and through variables of the circuit model are chosen to be rms force and rms displacement over the surface of the CMUT membrane. The relation between rms displacement and applied voltage is obtained through analytical calculations utilizing the exact force distribution. The radiation impedance...
The Axial PET (AX-PET) concept proposes a novel detection geometry for PET, based on layers of long scintillating crystals axially aligned with the bore axis. Arrays of wavelength shifting (WLS) strips are placed orthogonally and underneath the crystal layers; both crystals and strips are individually readout by G-APDs. The axial coordinate is obtained from the WLS signals by means of a Center-of-Gravity...
AX-PET is a novel PET concept based on long crystals axially arranged and orthogonal Wavelength shifter (WLS) strips, both individually readout by Geiger-mode Avalanche Photo Diodes (G-APD). Its design was conceived in order to reduce the parallax error and simultaneously improve spatial resolution and sensitivity. The assessment of the AX-PET concept and potential was carried out through a set of...
Our ultimate goal is to provide continuously updated 3-dimensional reconstructed PET images during surgery that are re-projected in real time onto a plane whose orientation is driven by a tracking device. The intra-operative PET imaging probe system can be viewed as a handheld, clinician-guided camera capable of seeing the distribution of the radiotracer. We present the first generation of the PET...
PET probes are showing a lot of promise in extending performance of the conventional PET ring. The underlying idea is to supplement basic PET data with information collected in the finely segmented probe placed close to the region of interest. The benefit is two fold: a) data collected near the object are less prone to errors related to scattering and acolinearity and b) the object itself is magnified...
Detection and spectroscopic tests of three self-triggered silicon detection modules constructed using Tape Automated Bonding and micro-cable technologies and equipped by VATA read-out chips are presented and compared. Results of these tests are demonstrated using hit maps and pulse-height spectra induced by 133Ba, 241Am, and 57Co radioactive sources of X- and gamma rays. We have observed significant...
Detection and spectroscopy tests of the first functional unit of a self-dependent silicon detection module constructed on the base of micro-cable and TAB technology are presented. The tests were performed using pulse-height analysis of the signals induced by gamma rays in the silicon sensor. Good shapes of the spectra and satisfactory spectroscopy resolution (given by FWHM which is less than 2 keV)...
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