Performance modelling for advanced envelope systems.

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Chemical Wave Computing from Labware to Electrical Systems

Unconventional and, specifically, wave computing has been repeatedly studied in laboratory based experiments by utilizing chemical systems like a thin film of Belousov–Zhabotinsky (BZ) reactions. Nonetheless, the principles demonstrated by this chemical computer were mimicked by mathematical models to enhance the understanding of these systems and enable a more detailedinvestigation of their capacity. As expected, the computerized counterparts of the laboratory based experiments are faster and less expensive. A further step of acceleration in wave-based computingis the development of electrical circuits that imitate the dynamics of chemical computers. A key component of the electrical circuits is the memristor which facilitates the non-linear behavior of the chemical systems. As part of this concept, the road-map of the inspiration from wave-based computing on chemical media towards the implementation of equivalent systems on oscillating memristive circuits was studied here. For illustration reasons, the most straightforward example was demonstrated, namely the approximation of Boolean gates

Mu2e Technical Design Report

The Mu2e experiment at Fermilab will search for charged lepton flavor violation via the coherent conversion process mu- N --> e- N with a sensitivity approximately four orders of magnitude better than the current world's best limits for this process. The experiment's sensitivity offers discovery potential over a wide array of new physics models and probes mass scales well beyond the reach of the LHC. We describe herein the preliminary design of the proposed Mu2e experiment. This document was created in partial fulfillment of the requirements necessary to obtain DOE CD-2 approval.Comment: compressed file, 888 pages, 621 figures, 126 tables; full resolution available at http://mu2e.fnal.gov; corrected typo in background summary, Table 3.

Measuring charged current neutrino interactions in the electromagnetic calorimeters of the ND280 detector

This thesis presents a study of neutrino interactions within the electromagnetic calorimeters (ECals) of the Tokai-to-Kamioka (T2K) off -axis near detector (ND280), using data collected from T2K Run II and Run III. Neutrino oscillation physics is a rapidly advancing field, with the recent discovery of non-zero [Symbol appears here. To view, please open pdf attachment]13 allowing the possibility of measuring CP-violation in the lepton sector. The current neutrino beam experiments must make precise measurements of the oscillation parameters and to do this require an improved understanding of neutrino interactions, which can only come through better measurements of neutrino cross-sections. This thesis describes the development of a neutrino event selection using a boosted decision tree multi-variate analysis to separate interactions within the ND280 ECals from entering backgrounds. This is then used to provide a selection of neutrino event samples from each ECal module, which are inputs to a X2 fit that is used to extract the [Symbols appears here. To view, please open pdf attachment] charged current inclusive cross-section, which was found to be [Mathematical equation appears here. To view, please open pdf attachment].Open Acces

Proposal to perform a high - statistics neutrino scattering experiment using a fine - grained detector in the NuMI Beam

The NuMI facility at Fermilab will provide an extremely intense beam of neutrinos for the MINOS neutrino-oscillation experiment. The spacious and fully-outfitted MINOS near detector hall will be the ideal venue for a high-statistics, high-resolution {nu} and {bar {nu}}-nucleon/nucleus scattering experiment. The experiment described here will measure neutrino cross-sections and probe nuclear effects essential to present and future neutrino-oscillation experiments. Moreover, with the high NuMI beam intensity, the experiment will either initially address or significantly improve our knowledge of a wide variety of neutrino physics topics of interest and importance to the elementary-particle and nuclear-physics communities

Reversible photochromism of synthetic hackmanites in radiation detection and quantification

The subject of this thesis is centered on a mineral called hackmanite, also known as photochromic sodalite. It is found naturally in remote, mountainous places in Afghanistan, Pakistan, Greenland, Russia, Canada, and the United States. The natural mineral is costly to extract and – depending on the location – its optical properties and chemical impurities vary arbitrarily. Thus, it is not only more predictable, but also sustainable to synthesize the mineral in a laboratory from traceable reagents that contain known amounts of impurities. The synthesis route used in the experimental section in this work is a solid-state method where the reagents are mixed and heated in an oven at 850 °C and reduced with a hydrogen‒nitrogen gas mixture. The product, hackmanite (Na8Al6Si6O24(Cl,S)2), shows properties including luminescence, persistent luminescence, and reversible photochromism upon exposure to UV, X, gamma, nuclear, or particle radiation. Hackmanite’s photochromism is of particular interest since the coloration from white to pink can be reversed with visible light or heat, and this cycle can be repeated indefinitely. Hackmanite is thus able to react to its surrounding radiation atmosphere, and what makes the property even more interesting is that upon high-energy gamma radiation exposure the material “remembers” the exposure with a change of its color centers. In UV-induced coloration, the mechanism involves an electron transfer from a disulfide anion to a nearby chloride vacancy, which is a defect in the lattice due to the requirement of charge neutrality in the crystal. However, in X-ray- or other highenergy radiation-induced coloration the incident energies are so high that the coloration is caused by core-shell electrons and subsequent holes trapping after thermalization. Due to the nature of the coloration process, hackmanite’s application region spans from the high-energy gamma radiation to UV, however the material can also be used to detect visible light since the bleaching process (electrons returning to disulfide ions from the trap) occurs in the visible wavelength region. This property can be used for taking a photograph, as is shown in this thesis. KEYWORDS: hackmanite, photochromism, radiation detection, dosimetry, photographyTämän väitöskirjan aiheena on hackmaniitti-niminen mineraali, joka tunnetaan myös nimellä fotokrominen sodaliitti. Sitä esiintyy luonnossa syrjäisillä vuoristoseuduilla Afganistanissa, Pakistanissa, Grönlannissa, Venäjällä, Kanadassa ja Yhdysvalloissa. Luonnonmineraalin louhinta on kallista ja kestämätöntä, ja sen optiset ominaisuudet ja kemialliset epäpuhtaudet vaihtelevat satunnaisesti riippuen sijainnista. Näin ollen on ennakoitavampaa ja kestävämpää syntetisoida mineraalia laboratoriossa reagensseista, jotka ovat jäljitettäviä ja sisältävät tunnetut määrät epäpuhtauksia. Tämän työn kokeellisessa osassa synteesit toteutettiin kiinteän olomuodon menetelmällä, jossa lähtöaineiden seos kuumennetaan uunissa 850 °C:ssa ja pelkistetään vetytyppikaasuseoksella. Tuotteella eli hackmaniitilla (Na8Al6Si6O24(Cl,S)2), on ominaisuuksinaan luminesenssi, jälkiloiste ja palautuva fotokromismi altistuessaan UV-, röntgen-, gamma‑, ydin- ja hiukkassäteilylle. Hackmaniitin fotokromismi on erityisen kiinnostava ominaisuus, sillä vaaleanpunaiseksi värjätty hackmaniitti voidaan palauttaa takaisin valkoiseksi näkyvällä valolla tai lämmöllä, ja tätä sykliä voidaan toistaa loputtomasti. Tämän ominaisuuden tekee vielä mielenkiintoisemmaksi se, että gammasäteilyaltistuksen yhteydessä materiaali ”muistaa” korkeaenergisen altistuksensa värikeskuksensa ‒ joka on olennainen rakenne värjäytymismekanismissa ‒ muutoksella. UV-värjäytymisessä mekanismi sisältää elektronin virittymisen disulfidianionista läheiseen kloridivakanssiin, mikä on kiteen varaustasapainovaatimuksen mukaisesti muodostunut hilavirhe. Röntgen- tai muun korkeaenergisen säteilyn aiheuttamassa värjäytymisessä energiat ovat kuitenkin niin suuria, että värjäytymisen aiheuttaa sisäkuorten elektronien ja aukkojen loukkuuntuminen termalisaation jälkeen. Värjääntymisprosessin ansiosta hackmaniitin käyttöalue ulottuu korkeaenergisestä gammasäteilystä UV-säteilyyn, mutta materiaalia voidaan käyttää myös näkyvän valon havaitsemiseen, sillä haalenemisprosessi (elektronien palaaminen loukuista takaisin disulfidi-ioneihin) tapahtuu näkyvällä aallonpituusalueella. Tätä ominaisuutta voidaan käyttää valokuvaamisessa. ASIASANAT: hackmaniitti, fotokromismi, säteilyn havainnointi, dosimetria, valokuvau

Analyse de la topologie des flammes prémélangées swirlées confinées

This work deals with the stabilization of premixed turbulent swirling flames of methane/hydrogen/air combustible mixtures with different dilution rates of nitrogen and carbon dioxide. A central bluff body helps stabilizing the flames at low swirl numbers. The flame tip eventually impinges the combustor peripheral wall. The general objective is to gain understanding of the mechanisms governing the stabilization and the topology of these flames. It is found that the swirl number, the combustible mixture composition, the geometry of the combustor, and the thermal boundary conditions have a strong impact on the shape taken by these flames. The experimental setup used to characterize flames topologies is first described. Flames prone to topology bifurcations are selected and are studied for different arrangement of the combustor when the combustion chamber shape and size, the injection tube diameter, and swirl number are varied. One operating condition is fully characterized under non-reactive and reactive conditions using Planar Hydroxyl Laser Induced Fluorescence (OH-PLIF), Particle Imaging Velocimetry (PIV), and Laser Induced Phosphorescence of thermographic phosphors (LIP) to generate a detailed database of the flow and the corresponding boundary conditions. An analysis is then conducted to understand the mechanisms controlling shape bifurcations when the flame interacts with the combustor peripheral wall. Effects of the combustible mixture composition, the bulk flow velocity, and the swirl number are analyzed. It is shown that the transition from a V to an M flame is triggered by a flashback of the V flame tip in the boundary layer of the combustor peripheral wall. Dimensionless numbers controlling these transitions are identified and a simplified model is developed to help the prediction of the flame shapes. The physics of these shape bifurcations differs when the flame does not interact with the combustor wall. The large influence of the hydrogen enrichment in the fuel on the flame shape is analyzed using flame chemiluminescence and OH-PLIF. LIP and thermocouple measurements demonstrate that the thermal boundary conditions still have a strong impact on the flame topology. The combined effects of strain and heat losses are investigated using joint OH-PLIF and PIV experiments. It is shown that flammability limits of premixed flames are reduced due to heat losses and the transitions from M to V shaped flames is consecutive to localized extinctions of flame front elements located in the outer shear layer of the jet flow that are submitted to large strain rates. These experiments are completed by an analysis of the dynamics of methane/hydrogen/air flames. It is shown that low frequency and high amplitude velocity modulations generated by a loudspeaker alter the shape taken by these flames. The stabilization of methane/hydrogen/air flames diluted by nitrogen and carbon dioxide is finally examined. It was possible to stabilize swirled flames featuring important dilution rates due to the presence of the bluff body, installed on the axis of the injection tube. The recirculation zone behind this element supplies hot burnt gases to the flame anchoring point. Using OH* chemiluminescence imaging, it is shown than increasing the molar fraction of diluent in the fuel reduces the light emission from excited OH* radicals. The influence of dilution on the flame chemistry is emphasized with experiments conducted at a fixed thermal power and fixed adiabatic flame temperature. It is also demonstrated that the composition of the diluent has a strong influence on the temperature field of the burnt gases and of the combustor wall surfaces. Dilution with carbon dioxide increases radiative heat losses from the burnt gases in comparison to dilution with nitrogen. This penalizes the combustor efficiency equipped with four transparent quartz walls. [...]Ce travail porte sur la stabilisation de flammes prémélangées et swirlées de mélanges combustibles méthane/hydrogène/air avec différents taux de dilution d’azote et de dioxyde de carbone. Une tige centrale permet de stabiliser des flammes pour de faibles nombres de swirl. Le sommet de la flamme interagît éventuellement avec les parois de la chambre de combustion. L’objectif ces travaux est d’améliorer la connaissance des mécanismes qui gouvernent la stabilisation et la topologie de ces flammes. Ces travaux démontrent que le nombre de swirl, la composition du mélange combustible, la géométrie de la chambre de combustion ainsi que les conditions aux limites thermiques ont une grande influence sur la forme prise par la flamme. Le dispositif expérimental permet de modifier la forme et la taille de la chambre de combustion, le diamètre du tube d’injection et le nombre de swirl. Des conditions opératoires propices aux transitions de forme de flamme sont ensuite étudiées pour différentes configurations de brûleur. Une caractérisation expérimentale fouillée d’un point de fonctionnement est réalisée grâce à la Fluorescence Induite par Laser sur le radical Hydroxyle (OH-PLIF), la Vélocimétrie par Images de Particules (PIV) et la Phosphorescence Induite par Laser de phosphores sensibles à la température (LIP). Une base de donnée de l’écoulement et des conditions aux limites associées est obtenue sans et avec combustion. Les mécanismes qui contrôlent les transitions de formes de flamme sont ensuite analysés lorsque la flamme interagit avec les parois de la chambre de combustion. L’influence de la composition du mélange combustible, de la vitesse débitante et du nombre de swirl est caractérisée et il est démontré que la transition d’une flamme en V vers une flamme en M est déclenchée par un retour de flamme dans la couche limite le long d’une des parois latérales de la chambre de combustion. Les nombres sans dimension contrôlant ces transitions sont identifiés et un modèle de prévision de la forme de ces flammes est développé. La physique déterminant les transitions de forme de flammes est différente lorsque celles-ci n’interagissent pas avec les parois de la chambre de combustion. En utilisant le signal de chimiluminescence OH* et la OH-PLIF, il est montré que la teneur en hydrogène dans le combustible a une grande influence sur la forme de flamme. L’utilisation de la LIP et de thermocouples a également permis de montrer que les conditions aux limites thermiques jouent un rôle prépondérant sur la forme de flamme. Les effets combinés de l’étirement et des pertes thermiques sont examinés par l’utilisation conjointe de la PIV et de la OH-PLIF. Il est montré que les limites d’extinction de flammes pauvres prémélangées sont réduites par les pertes thermiques et que la transition d’une flamme en M vers une flamme en V est consécutive à l’extinction du front de flamme situé dans la couche de cisaillement externe du jet soumis à un étirement trop important. Ces expériences sont complétées par une analyse de la dynamique de ces flammes. Des modulations de la vitesse débitante à basse fréquence et à haute amplitude modifient la forme de flamme. La stabilisation de flammes CH4/H2/air diluées par du N2 ou du CO2 est finalement examinée. La zone de recirculation produite par la tige centrale permet d’alimenter la base de la flamme avec des gaz brûlés chauds et de stabiliser des flammes fortement diluées. Augmenter la fraction molaire de diluant dans le combustible réduit l’intensité de lumière émise par le radical OH*. Il est également montré que la composition du diluant a un impact sur le champ de température des gaz brûlés et des surfaces de la chambre de combustion. La dilution par du CO2 augmente les pertes thermiques par rayonnement des gaz brûlés. Cela réduit l’efficacité de la chambre de combustion équipée de quatre parois transparentes. [...

A Lexical Description of English for Architecture: A Corpus-based Approach

Every knowledge community has a distinct type of discourse and a linguistic identity which brings together the ideas of that discipline. These are expressed through characteristic linguistic realizations which are of considerable interest in the study of English for Specific Purposes (ESP) from many different perspectives. Despite the fact that ESP is a recent area of linguistic research, there is already a varied literature on academic and professional languages: English for law, business, computer and technology, advertising, marketing and engineering, just to mention a few. According to Dudley-Evans (1998:19), the development of ESP arose as a result of general improvements in the world economy in the 1960’s, along with the expansion of science and technology. Other relevant factors were the growing use of English as the international language of science, technology and business, and the increasing flow of exchange students to and from the UK, US and Australia