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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

¡]¤@¡^Pyrolytic Study of 2-Azido-1-(4-methoxyphenyl)ethanone and 2-(2-Azidoethyl)furan¡]¤G¡^Pyrolytic Study of 3-Methyl-2-Cyclohexno[b]furylmethyl Benzoate

Chen, Shao-Yu 26 July 2012 (has links)
¤@¡BPyrolysis of 2-azido-1-(4-methoxyphenyl)ethanone (69) and 2-(2-azidoethyl)furan (85) gave nitrene intermediate to study. There is 2-(4-methoxybenzoyl)-4-(4- methoxyphenyl)imidazole (81) ¡B2-(4-methoxybenzoyl)-5-(4-methoxyphenyl) imidazole] (81¡¦)¡B2,3-di(4-methoxybenzoyl)-5-(4-methoxyphenyl) pyrazine] (82) and 3,5-di(2-furyl) pyridine (92) for pyrolysis products. ¤G¡BPyrolysis of3-methyl-2-cyclohexen[b] furylmethyl benzoate) (50) gave carbene intermediate to study. There is 2,3-dimethylene cyclohexen[b]furan (59) for pyrolysis products.
12

Energi- och kostnadsmässig jämförelse av FTX- och FVP-system i ett flerbostadshus : Jämförelse av ventilationssystem i ett flerbostadshus

Tofte, Nathalie January 2021 (has links)
The choice of heating system and to add heat recovery is becoming increasinglyimportant in order to meet the climate goals. The need for renovation of homesbuilt in the so-called million program is extensive. The purpose of the work is toevaluate two different ventilation systems and its profitability in connection withthe renovation of a property in Ljungby. The systems to be compared are asystem with presence-controlled FTX-apartment units and a system with exhaustair heat pumps. The goal is to present a result about which ventilation systemleads to the largest energy and cost savings compared to the existing ventilationsystem in the property.The results show that the ventilation system with presence-controlled FTXapartment units in each apartment should generate the lowest primary energy.The life cycle cost analysis showed that the most economically profitableventilation system is with FTX apartment units. The results also showed thatprojected and calculated average heat transfer coefficient can vary markedly. Insummary, the best choice is FTX apartment units with presence control. Thesystem consumes less energy than the FVP system, while avoiding dependenceon electrical energy.
13

Gas-phase electron diffraction studies of unstable molecules

Noble-Eddy, Robert January 2009 (has links)
Gas-phase electron diffraction (GED) is the only viable technique for the accurate structural study of gas-phase molecules that contain more than ~10 atoms. Recent advances in Edinburgh have made it possible to study larger, more complex, stable molecules using the SARACEN method. This thesis is concerned with obtaining the structures of unstable species, using both standard GED techniques and by developing a new method in which ash vacuum pyrolysis is used to generate short-lived species in situ. In the first part of this thesis nine primary phosphines (R-PH2) with different substituents (R = methyl, vinyl, ethynyl, allenyl, allyl, propargyl, phenyl, benzyl and chloromethyl) are studied by GED. Vinylarsine and vinyldichloroarsine are also studied. Primary phosphines and arsines appear infrequently in the literature owing to their toxicity and high reactivity, especially of the unsaturated systems. The conformational behaviour in these molecules and trends throughout the series are rationalised. As appropriate, comparisons are made to analogous amines and the differences found are discussed. Tertiary phosphines (R3P) are routinely protected by complexation with borane (BH3) and it has been proposed that this technique could be extended to primary phosphines. As an extension of the initial investigation, the GED study of methylphosphine-borane offers an insight into structural changes that occur upon complexation, although attempts to study larger phosphine-borane complexes by GED proved dificult. The structures and bonding trends in a series of phosphineborane adducts are discussed, mainly using the results of ab initio calculations. The second part of the thesis details the implementation of a new, very high temperature nozzle, which allows the generation of short-lived species by pyrolysis. The workings of this nozzle are discussed and the study of the structure of ketene, generated from three different precursors, is detailed. The benzyl radical has also been studied, and a preliminary GED structure is presented. As a result of this work the molecular structures of Meldrum's acid and dibenzylsulfone are also presented, having been determined in the gas phase for the first time.
14

Att bygga energisnålt med olika ventilationssystem / To build energy efficient with various ventilation systems

Bengtsdottir, Fanney, Hagerup Norrman, Christel January 2018 (has links)
Ett ventilationssystem i en byggnad ska tillföra en tillräcklig mängd frisk luft och skapa ett undertryck för att minska fuktrelaterade problem. Idag finns flera typer av ventilationssystem tillgängliga, några med värmeåtervinning, vilka bidrar med olika funktioner och begränsningar. Studien undersöker skillnaden mellan frånluftsventilation (F), frånluftsvärmepump (FVP) samt fläktstyrt till- och frånluftssystem med roterande återvinning (FTX) i NNE-hus. Tre enfamiljshus i Kronobergs län blev strategiskt utvalda för insamling av data, mätningar, intervjuer och beräkningar. Därefter gjordes en utvärdering och jämförelse mellan systemens prestanda med avseende på termisk komfort, luftomsättning, effektbehov, energianvändning och kostnader. Resultaten visar att kriterierna för termisk komfort uppfylls i samtliga hus under tiden för undersökningar och den specifika energiförbrukningen för de olika husen är mindre än hälften av det maximalt tillåtna. El- och värmeeffektbehovet är minst för F-systemet enligt resultaten men FVP är mest lönsam med hänsyn till återvinning. FVP är även mest lönsam med avseende på ackumulerade kostnader. Resultaten är begränsade för ett specifikt uteklimat under perioden för undersökningen. För en större översikt och tillförlitlighet i beräkningar rekommenderas studier som sträcker sig över ett år. / A ventilation system in a building provides sufficient amount of fresh air and create a negative pressure to reduce moisture-related problems. Today several ventilation systems, some with different energy recovery, are available and those inherence different features and limitations. This study examines differences between exhaust air ventilation without heat recovery (F), exhaust air heat pump (FVP) and exhaust and supply air ventilation with a rotating heat exchanger (FTX) in nearly zero-energy houses. Three single-family houses in Kronoberg County were strategically chosen for the data collection, measurements, interviews and calculations to evaluate and compare their system’s performances in terms of thermal comfort, air circulation, heat recovery effects, energy use and financial attractiveness. The results show that the criteria for thermal comfort are satisfied and the specific energy consumption are within the current requirements in all these houses. Under the period of investigation, the house without heat recovery requires minimum quantity of electricity for ventilation system where as the house with FVP is the most energy efficient. Also, the house with an FVP shows to be the most cost-efficient with lowest accumulated costs. The results are limited for a specific outdoor climate during the studied period. Therefore, examinations over a longer term in different contexts are recommended for a more comprehensive view.

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