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Este trabalho consiste no desenvolvimento de um detector composto por um calorímetro com núcleo de água para dosimetria de feixes de 60Co e 137Cs com média intensidade. Além do calorímetro, foi também dimensionada a instrumentação, a metodologia de calibração e a medição de temperatura. O trabalho foi dividido em 4 etapas distintas: escolha do melhor projeto como base para desenvolvimento do calorímetro, dimensionamento de parâmetros e ajuste fino do projeto, construção e calibração. Durante o desenvolvimento deste trabalho foi construída uma Unidade de Tratamento de Água que permite a produção da água que o calorímetro emprega. Em seguida foi construído o calorímetro em sí com os conceitos das etapas anteriores. O equipamento foi testado tanto nas instalações da GMR quanto no CTR do IPEN, obtendo taxas de dose na água com fontes de 137Cs e 60Co com diversas atividades (3,3 TBq, 15,54 TBq e 7 TBq) e em algumas distâncias. Foram obtidas taxas de dose que variavam de 2 mGy/s até 15 mGy/s, dependendo do tipo de fonte e SDD escolhida. O projeto contou com simulações de códigos como MCNP5 e FLUENT 14 e foram essenciais na construção do equipamento. O objetivo deste trabalho foi aprimorar a infraestrutura do LCI, desenvolvendo um detector que deverá aumentar a gama dos serviços prestados pelo LCI com um tipo de medição dosimétrica ainda inexistente no país. / This work aims to develop a radiation detector composed by a water calorimeter for beam dosimetry of 60Co and 137Cs gamma radiation with medium intensity. Besides the calorimeter itself, all the instrumentation, methodology, calibration and testing protocols were established. This work was divided into 4 parts: the choice of the best design; simulation and setting of the ideal operation parameters; adaptation of the project; construction and calibration. During the development of this work a water treatment unit was built which allows the production of distilled water for the calorimeter. Then the calorimeter itself was built with the concepts from the previous steps. The equipment has been tested both in the facilities of GMR as the CTR at IPEN, obtaining dose rates ( from 2 mGy/s up to 15 mGy/s) in water for 137Cs and 60Co sources in some activities (3,3 TBq, 15,54 TBq e 7 TBq) and distances. The MCNP5 and FLUENT 14 have been used and proved essential in the development of the prototype. The main goal was to improve the LCI infrastructure with a new radiation detector that will increase the calibration laboratory service range with a still absent kind of dosimetric measurement in Brazil.

A fire growth calculation method has been developed that couples a computational fluid dynamics (CFD) model with bench scale cone calorimeter test data for predicting the rate of flame spread on compartment contents such as furniture. The commercial CFD code TASCflow has been applied to solve time averaged conservation equations using an algebraic multigrid solver with mass weighted skewed upstream differencing for advection. Closure models include k-epsilon for turbulence, eddy breakup for combustion following a single step irreversible reaction with Arrhenius rate constant, finite difference radiation transfer, and conjugate heat transfer. Radiation properties are determined from concentrations of soot, CO2 and H2O using the narrow band model of Grosshandler and exponential wide band curve fit model of Modak. The growth in pyrolyzing area is predicted by treating flame spread as a series of piloted ignitions based on coupled gas-fluid boundary conditions. The mass loss rate from a given surface element follows the bench scale test data for input to the combustion prediction. The fire growth model has been tested against foam-fabric mattresses and chairs burned in the furniture calorimeter. In general, agreement between model and experiment for peak heat release rate (HRR), time to peak HRR, and total energy lost is within pm 20%. Used as a proxy for the flame spread velocity, the slope of the HRR curve predicted by model agreed with experiment within pm 20% for all but one case.

Traditional probability and statistics methodologies recommended by ISO and NIST were applied to standardize measurement uncertainty analysis on calorimetry bench scale apparatuses. The analysis was conducted for each component instrument (direct measurement) and each related physics quantity measured indirectly. There were many sources contributing to the ultimate uncertainty, however, initially, we dealt with the intrinsic uncertainty of each measuring instrument and the uncertainty from calibration. All other sources of uncertainty, i.e., drift, data acquisition, data reduction (round off, truncation, and curve smoothing) and personal operation were assumed to be negligible. Results were expressed as an interval having 95% confidence that the ¡°true¡± value would fall within. A Monte Carlo Simulation technique with sampling size of 10000 was conducted to model the experiments. It showed that at least 95% of the modeled experiment results were inside the estimate interval. The consistency validated our analysis method. An important characteristic of composite material systems is the ability to ¡°custom design¡± the system to meet performance criteria such as cost, durability, strength and / or reaction to fire. To determine whether a new system is an improvement over previous ones and can meet required performance criteria, sufficiently accurate and precise instruments are needed to measure the system¡¯s material properties in bench scale testing. Commonly used bench scale apparatuses are the cone calorimeter (Cone) and the FMGR fire propagation apparatus (FPA). For this thesis, thermally ¡°thin¡± and ¡°thick¡± specimens of a natural composite, red oak, were tested in the Cone in an air environment and in the FPA in a nitrogen environment. Cone test data of two FRP composite systems from the previous work of Alston are also considered. The material reaction to fire properties were estimated considering both ignition and pyrolysis measurements made via the Cone and FPA. Investigation of the ultimate uncertainty of these material fire properties based on the intrinsic uncertainty of the component instruments (e.g. load cell) as well as the uncertainty introduced via use of a current ignition and pyrolysis model are considered.

Este trabalho consiste no desenvolvimento de um detector composto por um calorímetro com núcleo de água para dosimetria de feixes de 60Co e 137Cs com média intensidade. Além do calorímetro, foi também dimensionada a instrumentação, a metodologia de calibração e a medição de temperatura. O trabalho foi dividido em 4 etapas distintas: escolha do melhor projeto como base para desenvolvimento do calorímetro, dimensionamento de parâmetros e ajuste fino do projeto, construção e calibração. Durante o desenvolvimento deste trabalho foi construída uma Unidade de Tratamento de Água que permite a produção da água que o calorímetro emprega. Em seguida foi construído o calorímetro em sí com os conceitos das etapas anteriores. O equipamento foi testado tanto nas instalações da GMR quanto no CTR do IPEN, obtendo taxas de dose na água com fontes de 137Cs e 60Co com diversas atividades (3,3 TBq, 15,54 TBq e 7 TBq) e em algumas distâncias. Foram obtidas taxas de dose que variavam de 2 mGy/s até 15 mGy/s, dependendo do tipo de fonte e SDD escolhida. O projeto contou com simulações de códigos como MCNP5 e FLUENT 14 e foram essenciais na construção do equipamento. O objetivo deste trabalho foi aprimorar a infraestrutura do LCI, desenvolvendo um detector que deverá aumentar a gama dos serviços prestados pelo LCI com um tipo de medição dosimétrica ainda inexistente no país. / This work aims to develop a radiation detector composed by a water calorimeter for beam dosimetry of 60Co and 137Cs gamma radiation with medium intensity. Besides the calorimeter itself, all the instrumentation, methodology, calibration and testing protocols were established. This work was divided into 4 parts: the choice of the best design; simulation and setting of the ideal operation parameters; adaptation of the project; construction and calibration. During the development of this work a water treatment unit was built which allows the production of distilled water for the calorimeter. Then the calorimeter itself was built with the concepts from the previous steps. The equipment has been tested both in the facilities of GMR as the CTR at IPEN, obtaining dose rates ( from 2 mGy/s up to 15 mGy/s) in water for 137Cs and 60Co sources in some activities (3,3 TBq, 15,54 TBq e 7 TBq) and distances. The MCNP5 and FLUENT 14 have been used and proved essential in the development of the prototype. The main goal was to improve the LCI infrastructure with a new radiation detector that will increase the calibration laboratory service range with a still absent kind of dosimetric measurement in Brazil.

The PAMELA satellite experiment will soon be launched and during its 3 year mission perform measurement of charged particle fluxes in the cosmic radiation. PAMELA is specifically designed to identify antiprotons and positrons in the vast background of other charged particles. These antiparticle measurements will be performed using: a permanent magnet spectrometer, a scintillator based time of flight system, an electromagnetic imaging calorimeter, a transition radiation detector and a scintillator triggered neutron detector. There is also a scintillator based anticoincidence system to reject spurious triggers from out of acceptance events (developed and built at KTH). These detectors will allow the background in the antiproton and positron measurements to be significantly reduced, and PAMELA will thus be able to perform high precision measurements with unprecedented statistics and over a wide energy range, far surpassing any previous experiment. To determine the antiparticle identification and background rejection capability of the experiment, studies have been performed using simulations and data collected at particle beams. These studies have focused on: the proton rejection in positron measurements (using the calorimeter), contamination by locally produced pions in antiproton measurements and estimations of the expected statistics due to the energy dependence (caused by e.g. the geomagnetic field and the magnetic field in the spectrometer) of the gathering power. This work significantly extends previous studies of the PAMELA performance in antiparticle identification.

<p>The PAMELA satellite experiment will soon be launched and during its 3 year mission perform measurement of charged particle fluxes in the cosmic radiation. PAMELA is specifically designed to identify antiprotons and positrons in the vast background of other charged particles. These antiparticle measurements will be performed using: a permanent magnet spectrometer, a scintillator based time of flight system, an electromagnetic imaging calorimeter, a transition radiation detector and a scintillator triggered neutron detector. There is also a scintillator based anticoincidence system to reject spurious triggers from out of acceptance events (developed and built at KTH). These detectors will allow the background in the antiproton and positron measurements to be significantly reduced, and PAMELA will thus be able to perform high precision measurements with unprecedented statistics and over a wide energy range, far surpassing any previous experiment. To determine the antiparticle identification and background rejection capability of the experiment, studies have been performed using simulations and data collected at particle beams. These studies have focused on: the proton rejection in positron measurements (using the calorimeter), contamination by locally produced pions in antiproton measurements and estimations of the expected statistics due to the energy dependence (caused by e.g. the geomagnetic field and the magnetic field in the spectrometer) of the gathering power. This work significantly extends previous studies of the PAMELA performance in antiparticle identification.</p>

Extracts from Thesis (Ph. D.)--University of Michigan, 1934. / Part 2 has title: Evaluation of oils from the manufacture of carburetted water gas by their available hydrogen content. Bibliography at end of each part.

A search for displaced photons from exotic decays of the Higgs boson is presented, specifically targeting the relatively weak constraints on the branching ratio of Higgs boson decays to invisible particles imposed by other searches. 139 fb⁻¹ of 𝑝-𝑝 collision data at center-of-mass energy √𝑠 = 13 TeV, collected between 2015 and 2018, is analyzed. Exploiting the excellent timing performance and longitudinal segmentation of the ATLAS electromagnetic calorimeter, the photon arrival time and extrapolation to the beam axis, or pointing, can be used to extract the displaced photon signature from Standard Model background processes. The background photon timing and pointing distributions are predicted using carefully constructed, data-derived templates. Signal contributions are analyzed in the context of a Gauge-Mediated Supersymmetry Breaking model in which the Higgs boson decays into two, long-lived next-to-lightest supersymmetric particle neutralinos, which each subsequently decay into a photon and a gravitino. Agreement with background is observed with no significant excesses for any signal models considered. Limits at the 95% confidence level are placed on the branching ratio of the Higgs boson to two neutralinos in the context of the various signal models.