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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Medição individualizada em edifícios residenciais : controle e redução do consumo de água potável / Individual measurement in residential buldings: control and reduction of the drinking water consumption

Holanda, Marcos Antonio Arruda Guerra de 25 April 2007 (has links)
Made available in DSpace on 2017-06-01T17:57:21Z (GMT). No. of bitstreams: 1 Marcos Holanda_Diss.pdf: 1903157 bytes, checksum: 12aff14850e97e4c1b0c835c68b68342 (MD5) Previous issue date: 2007-04-25 / Brazil: a water country. This thought could take the people to forget about water conservation. Although Brazil has big watersheds, it also has regions that present serious water supply crisis. The amazon region, with only 5% of brazilian population, stores 80% of water volume of all national territory, while greater part of the population is concentrated in the big cities, needing, at times, a higher volume of water. The individual measurement in residential buildings is one of the most important ways to prevent water lavishness, also to control and to reduce the water consumption. This work tries to show the individual measurement of water as a fair system of price, which permits the control and the reduction on the water consumption. In the firs part, three buildings that had changed from global measurement system to individual measurement system were studied. By these cases, it was possible to show, in the buildings, the distribution of the apartments in classes of consumption, the percentage reduction and the economic feasibility to perform the modification in the measurement system. The second part of this work was to follow a telemetric measurement system in a residential building with individual water meters. The telemetric measurement allowed to know the profile of each consumer, individually, as an important way to plan actions to control and to reduce the water consumption. / Brasil, país das águas. Este é um pensamento que pode levar a uma despreocupação quanto à conservação da água. Sim, o Brasil possui grandes bacias hidrográficas, mas, por outro lado, possui também regiões que apresentam graves crises de abastecimento. A região amazônica, com apenas 5% da população brasileira, armazena 80% do volume de água de todo o território nacional, enquanto grande parte da população concentra-se nas grandes cidades, exigindo um volume de água cada vez maior. A medição individualizada em edifícios residenciais apresenta-se como um dos meios importantes para combater o desperdício, controlar e reduzir o consumo de água. Este trabalho procura mostrar a medição individualizada como um sistema justo que permite o controle e a redução de água. Numa primeira etapa, foram estudados três edifícios que sofreram reforma, passando do sistema com medição global para o sistema com medição individualizada. Através destes três estudos de casos, foi possível mostrar a distribuição dos apartamentos em classes de consumo, a redução percentual do consumo do edifício e a viabilidade econômica para a execução da reforma. A segunda etapa deste trabalho, compreendeu o acompanhamento da medição por telemetria, associada à medição individualizada, em um edifício residencial. A medição por telemetria permitiu o traçado do perfil de cada consumidor, individualmente, funcionando como uma ferramenta importante para o planejamento de ações que visem ao controle e a redução do consumo de água.
12

Single photon detection based devices and techniques for pulsed time-of-flight applications

Hallman, L. (Lauri) 08 December 2015 (has links)
Abstract In this thesis, a new type of laser diode transmitter using enhanced gain-switching suitable for use with a single photon avalanche diode (SPAD) detector was developed and tested in the pulsed time-of-flight laser range finding (lidar) application. Several laser diode versions were tested and the driving electronics were developed. The driving electronics improvements enabled a pulsing frequency of up to 1 MHz, while the maximum laser output power was about 5–40 W depending on the laser diode dimensions. The large output power is advantageous especially in conditions of strong photon noise emerging from ambient light outdoors. The length of the laser pulse matches the jitter of a typical SPAD detector providing several advantages. The new laser pulser structure enables a compact rangefinder for 50 m distance measurement outdoors in sunny conditions with sub-centimeter precision (σ-value) at a valid distance measurement rate of more than 10 kHz, for example. Single photon range finding techniques were also shown to enable a char bed level measurement of a recovery boiler containing highly attenuating and dispersing flue gas. In addition, gated single photon detector techniques were shown to provide a rejection of fluorescent photons in a Raman spectroscope leading to a greatly improved signal-to-noise ratio. Photonic effects were also studied in the case of a pulsed time-of-flight laser rangefinder utilizing a linear photodetector. It was shown that signal photon noise has an effect on the optimum detector configuration, and that pulse detection jitter can be minimized with an appropriate timing discriminator. / Tiivistelmä Tässä työssä kehitettiin uudentyyppinen, tehostettua "gain-switchingiä" hyödyntävä laserdiodilähetin käytettäväksi yksittäisten fotonien avalanche-ilmaisimien (SPAD) kanssa, ja sitä testattiin pulssin lentoaikaan perustuvassa laseretäisyysmittaussovelluksessa. Useita laserdiodiversioita testattiin ja ohjauselektroniikkaa kehitettiin. Ohjauselektroniikan parannukset mahdollistivat jopa 1 MHz pulssitustaajuuden, kun taas laserin maksimiteho oli noin 5–40 W riippuen laserdiodin dimensioista. Suuri lähtöteho on edullinen varsinkin vahvoissa taustafotoniolosuhteissa ulkona. Laserpulssin pituus vastaa tyypillisen SPAD-ilmaisimen jitteriä tarjoten useita etuja. Uusi laserpulssitinrakenne mahdollistaa esimerkiksi kompaktin etäisyysmittarin 50 m mittausetäisyydelle ulkona aurinkoisessa olosuhteessa mm–cm -mittaustarkkuudella (σ-arvo) yli 10 kHz mittaustahdilla. Yksittäisten fotonien lentoaikamittaustekniikan osoitettiin myös mahdollistavan soodakattilan keon korkeuden mittauksen, jossa on voimakkaasti vaimentavaa ja dispersoivaa savukaasua. Lisäksi portitetun yksittäisten fotonien ilmaisutekniikan osoitettiin hylkäävän fluoresenssin synnyttämiä fotoneita Raman-spektroskoopissa, joka johtaa selvästi parempaan signaali-kohinasuhteeseen. Fotoni-ilmiöitä tutkittiin myös lineaarista valoilmaisinta hyödyntävän pulssin kulkuaikamittaukseen perustuvan lasertutkan tapauksessa. Osoitettiin, että signaalin fotonikohina vaikuttaa optimaaliseen ilmaisinkonfiguraatioon, ja että pulssin ilmaisujitteri voidaan minimoida sopivalla ajoitusdiskriminaattorilla.

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