Multi-objective design and optimization of district energy systems including polygeneration energy conversion technologies

In the present context of finding ways to decrease CO2 emissions linked with human activity, district energy systems including polygeneration energy conversion technologies are likely to play a major role. District energy systems meet the heating, hot water, cooling and electricity requirements of a district. Because they meet several types of energy requirements, and for more than one single building, district energy systems represent good opportunities to implement polygeneration energy conversion technologies. Polygeneration energy conversion technologies indeed provide different energy services simultaneously, helping to decrease the CO2 intensity compared to energy conversion technologies that meet only one energy service. Moreover, when providing energy to a whole district, polygeneration energy conversion technologies can take advantage of the various load profiles of the buildings by compensating the fluctuations and having therefore a smoother operation. A district energy system comprises essentially two parts: the plant with the polygeneration energy conversion technologies, and the distribution networks (heating and cooling). When designing the energy system for a district, one has therefore to define which type of polygeneration energy conversion technologies are best suited for the district, as well as which building are worse connecting to the system and which buildings shouldn't be connected (for instance if they are located too far away from the other buildings or if they have too small requirements to justify a connection from the plant). Moreover the operation strategy needs to be defined. In the present thesis, a method is developed that helps designing and optimizing district energy systems, from the structuring of the information available for the district (energy consumption profiles, location of the buildings, available energy sources, possible layouts for the pipes,...), over the thermo-economic modelling of the energy conversion technologies, the design of the network and the simulation of its operation strategy, and finally the evaluation of the results in terms of CO2 emissions and costs. The design and optimization of the district energy system is a multi-objective Mixed Integer Non Linear Programming problem. To solve this problem, a decomposition strategy including a master and a slave problem was developed. The master optimization problem takes care of the energy conversion technologies, whereas the slave optimization problem optimizes the network part. The two sub-problems are solved iteratively and result in the definition of a Pareto optimal curve that gives the trade-offs between the emissions and the costs for various configurations satisfying the requirements of the district. A configuration is characterized by given types and sizes of energy conversion technologies, their location in the district, the network layout, as well as the operation strategy of the technologies. Due to the time dependent energy consumption profiles and the geographical location of the buildings and plant, the method developed combines two well known types of problems, namely the multi-period optimization problems and the network problems. The method developed allows to take into account various constraints such as limited availability of energy sources, forbidden connections between buildings (for instance if a large river separates these two buildings), or else space limitations in underground technical channels. The capabilities of the method are demonstrated by means of a test case, as well as a real case in the Canton of Geneva. The results show the importance of considering all the energy services together (and not separately). Energy systems including a gas engine or a gas turbine combined cycle, together with heat pumps, indeed help decreasing both the emissions and the costs compared to the actual configurations. In the Geneva case study for instance, emissions can be decreased by up to 45%, with a simultaneous costs reduction of 24%. However, the method only deals with water networks, while in some cases space limitations and safety issues make the use of water impossible. A new type of district energy system based on CO2 as energy transfer medium (instead of water), is therefore developed in order to take such issues into account. This new system, that led to the submission of a patent, meets all the different types of energy requirements with only two pipes (instead of three or four like in conventional water based system), and uses the latent heat of CO2 as driving force, instead of the specific heat

A RELEITURA INSÓLITA DAS GUERRAS EM "O LIVRO DAS NOITES" DE SYLVIE GERMAIN

A proposta deste estudo é analisar o surgimento de uma nova manifestação do insólito ficcional no cenário literário francês novecentista, caracterizada pela incorporação insólita de eventos históricos. Utilizando a noção de “metaficção historiográfica” proposta por Linda Hutcheon, examinaremos a confluência entre elementos insólitos e referências históricas em O Livro das Noites, de Sylvie Germain, publicado em 1985. Tal romance, caracterizado pela fusão entre o ordinário e o extraordinário, apresenta eventos históricos, como a guerra franco-prussiana e as guerras mundiais, que provocam reações sobrenaturais nos personagens. Este artigo visa identificar, por um lado, como os elementos insólitos ilustram a dimensão histórica dos personagens e, por outro lado, como o romance atribui uma conotação irreal aos eventos que constituem a história do Ocidente

Landsskytterstevnets suksesskriterier og suksessfaktorer

Masteroppgave i økonomi og administrasjon - Universitetet i Agder 2012Utgangspunktet for denne oppgaven er å se på hvordan Landsskytterstevnet planlegges og gjennomføres. Oppgaven har som mål å finne ut hva som bidar til at arrangementet blir en suksess og derfor kunne si noe om hva arrangører av Landsskytterstevnet i fremtiden bør fokusere på. Oppgavens tredje del definerer suksesskriterier og suksessfaktorer og sammenhengen mellom disse. Teoridelen munner ut i figur 7 i del 3.4 Sammenheng mellom suksessfaktorer og suksesskriterier og forsøker å beskrive forholdet mellom disse. Undersøkelsen har en kvantitativ del og en supplerende kvalitativ del. I den kvantitative delen er det gjennomført en faktoranalyse av både suksesskriteriene og suksessfaktorene. En regresjonsanalyse og korrelasjonsanalyse er videre gjennomført for suksessfaktorene. Faktoranalysen grupperer variabler sammen og er utgangspunktet for faktorene som videre analyseres. Landsskytterstevnet vurderes å være en stor suksess av både arrangører, skyttere, foresatte til skyttere og publikum. Arrangørene vurderer stevnene i større grad enn brukerne å være en suksess. Suksessfaktorene F.1 Prosjektets_målsetting, F.7 Frivillige og F.14 Læring_fra_eget_LS fremgår av den kvantitative analysen som de viktigste for å oppnå suksess. Den kvalitative analysen viser at flere, og andre, faktorer er viktige for oppnåelsen av suksess. Analysen viser at hovedfokuset bør legges på faktorene F.2 Støtte_fra_toppledelsen, F.8 Organisering_av_teamet, F.10 Kommunikasjon, F.12 Problemløsing og F.13 Læring_fra_andre_LS

Impact du Percussionaire® et de la kinésithérapie respiratoire conventionnelle après chirurgie cardiaque : étude randomisée contrôlée

peer reviewedaudience: researcher, professional, studen

Immunologic and Molecular Characteristics of Encephalitozoon-Like Microsporidia Isolated from Humans and Rabbits Indicate That Encephalitozoon cuniculi Is a Zoonotic Parasite

To assess the zoonotic potential of Encephalitozoon-like microsporidia, we isolated and cultivated spores from specimens of urine, respiratory secretions, and stool from six patients infected with human immunodeficiency virus and from nine rabbits. Because spores of Encephalitozoon-like species are indistinguishable by microscopy, we characterized the isolates by western blot analysis and by restriction enzyme analysis of the small subunit (SSU) rDNA after amplification by the polymerase chain reaction. We identified Septata intestinalis in one patient and Encephalitozoon hellem in two symptomatic patients. Encephalitozoon cuniculi was found in all rabbits and in three patients. One of these patients had clinical manifestations of infection with this parasite (severe interstitial pneumonitis). We observed abatement of symptoms and cessation of parasite excretion when these patients were treated with albendazole. Our findings suggest that E. cuniculi may be pathogenic in humans and that it is a zoonotic parasit

Assessment of Confounding Factors Affecting the Tumor Markers SMRP, CA125, and CYFRA21-1 in Serum

The purpose of this analysis was to evaluate if serum levels of potential tumor markers for the diagnosis of malignant mesothelioma and lung cancer are affected by confounding factors in a surveillance cohort of workers formerly exposed to asbestos. SMRP, CA125, and CYFRA21-1 concentrations were determined in about 1,700 serum samples from 627 workers formerly exposed to asbestos. The impact of factors that could modify the concentrations of the tumor markers was examined with linear mixed models. SMRP values increased with age 1.02-fold (95% CI 1.01–1.03) and serum creatinine concentration 1.32-fold (95% CI 1.20–1.45). Levels differed by study centers and were higher after 40 years of asbestos exposure. CA125 levels increased with longer storage of the samples. CYFRA21-1 values correlated with age 1.02-fold (95% CI 1.01–1.02), serum creatinine 1.21-fold (95% CI 1.14–1.30) and varied by study centers due to differences in sample handling. Tumor marker concentrations are influenced by subject-related factors, sample handling, and storage. These factors need to be taken into account in screening routine