Dans l'industrie métallurgique, le refroidissement est une étape fondamentale qui permet de donner certaines qualités aux matériaux (résistance mécanique, souplesse). L'impact d'un spray est une méthode de refroidissement connue mais mal comprise, limitant aujourd'hui ses champs d'applications. Cette thèse vise à mettre en place un outil numérique apte à l'étude et à l'optimisation futur du refroidissement par spray. La littérature met en évidence la multitude des mécanismes du refroidissement, et le peu d'informations sur les liens entre ces mécanismes et les caractéristiques du spray (diamètre, vitesse et répartition spatiale des gouttes). Pour simuler le refroidissement, on propose de séparer l'étape d'écoulement du spray de celle du calcul du refroidissement de la plaque. Une corrélation sur la densité de flux de chaleur issue de la littérature permet de lier les deux étapes. Une analyse poussée du spray est réalisée grâce à plusieurs outils expérimentaux: Analyseur à Phase Doppler, caméra rapide, mesure de débit surfacique. Les éléments clefs pour caractériser puis initialiser le spray dans la simulation sont ainsi mis en évidences. La méthode d'initialisation, la configuration numérique (Euler-Lagrange, modèle RANS k-ω), ainsi que le domaine de calcul sont validés avec l'écoulement d'un spray libre. La méthode est ensuite utilisée pour simuler l'écoulement du spray en présence d'une plaque. Finalement, le refroidissement d'une plaque est simulé. On obtient la densité de flux de chaleur extraite de la plaque en fonction des caractéristiques du spray. Cette thèse soulève des questions sur des points de simulation couramment utilisés mais menant à des erreurs dans le calcul du refroidissement / In the metallurgy industry, the cooling is a fundamental stage which allows to bring certain qualities to materials (mechanical resistance, flexibility). The impact of a spray is one known process but it is not well understood, limiting its today's scopes. This thesis aims at developing a simulation procedure, in order to obtain a useful numerical tool for the study and the future optimization of the spray cooling. Literature highlights the multitude of the mechanisms of spray cooling, but also the few existing information linking these mechanisms and the characteristics of the spray (diameter, speed and space distribution of droplets). In order to simulate the spray cooling, one proposes to split this process in two stages, the spray flow and the calculation of the cooling. Based on the literature, a correlation on the density of flow of heat removed from the plat is used to link the two stages. A full spray characterization is realized thanks to several experimental tools: Phase Doppler Analyser, speed-camera, measure of surface liquid flow density. Key elements required to characterize and also to initialize the spray in the simulation, are highlighted as well. The method of initialization, the numerical configuration (Eulerian-Lagrangian simulation, RANS k-ω turbulence model), as well as the domain of calculation are validated with the simulation of a free-fall spray. The method is then used to calculate characteristics of the spray in the presence of a surface. Finally, the cooling of plate is simulated, bringing results on the heat flow density removed from the plate in accordance with characteristics of the spray. Main results concern the highlighting of major points of simulation communally used but leading to error in the cooling simulation

The interest of gaining on-line information related to non-metallic inclusions during the steelmaking process has recently increased due to the development as well as the promising results of the Pulse Distribution Analysis with Optical Emission Spectroscopy method (PDA/OES). Even though, the time from sampling to presented results on inclusions is only about 5-10 minutes, the method has also shown limitations with respect to the determination of some inclusion characteristics. Therefore, a first step was to perform a study on other methods such as the cross-section method (CS) on a polished sample surface, the cross-section after etching method (CSE), the bromine-methanol extraction method (BME), and the electrolytic extraction method (EE). This study focused on the evaluation of these methods with respect to the time consumption for preparation and analysis of a sample, the analyzed volume and the determination of inclusion and cluster characteristics such as size, number, particle size distribution (PSD) and composition. The CS and CSE methods were found to be suitable in the determination of the largest cluster in a sample which can be recommended in order to select proper extraction parameters for further studies. The BME method was considered to be fast with the possibility of analyzing a large volume. However, the used solution is chemically stronger compared to electrolytic extraction solutions, which can affect the results. In most aspects, the EE method was found to be the most stable, reliable and accurate method with some limitations regarding the time aspect. Based on this conclusion, the EE method was selected for a comparative study with the PDA/OES method. Reliably detected size ranges by using the PDA/OES method were defined for two low-alloyed steel grades. These are 2.0-5.7 μm and 1.4-5.7 μm for steel samples taken before and after a Ca-addition during the secondary steelmaking, respectively. Moreover, agreements between the EE and PDA/OES methods were observed in the average size and number of detected inclusions when only inclusions with the size &gt; 2 μm were considered. Also, a theoretical minimum size and a maximum number ofinclusions present in the steel sample, which can be detected by using the PDA/OES method, were estimated. The work continued by successfully applying the EE method to study correlations between inclusions observed in the liquid steel samples and in a clogged nozzle (clogging material). It was found that the average sizes of spherical and non-spherical inclusions observed in the steel corresponded well with those observed in the clogging material. However, there were some differences in the frequencies of these inclusions. This was explained by a possible transformation of the present inclusions due to a reoxidation and a reaction with the nozzle refractory of the steel melt. The results of this study may contribute in the selection of proper process parameters or inclusion characteristics for future studies on the improvement and application of on-line methods. Finally, suggestions on how to present and interpret data obtained by the PDA/OES method during production of stainless steels were given in the present thesis. More specifically, the possibilities of defining operating windows with respect to inclusion composition and the use of a B-factor for Al (the total content of Al in inclusions detected by using the PDA/OES method) during the secondary steelmaking were discussed. In addition, a correlation study between B-factors for Al and numbers of inclusions (dV &gt; 4 μm) obtained by using the PDA/OES method on process samples, and corresponding slivers indices from plate products was performed. The results showed a moderate correlation between these parameters as well as an increase of the slivers index with increased values of the chosen PDA/OES data. This indicates that it could be possible to predict when there is an increased risk of having slivers on the final rolled product at an early stage of the steelmaking process. / <p>QC 20150525</p>

In the pre-genomic era, the relationships among species and their evolutionary histories were often determined by examining the fossil records. In the genomic era, these relationships are identified by analysing the genetic data, which also enables us to take a close-up view of the differences between the individual samples. Nevertheless, these relationships are often described by a tree-like structure or a network. In this thesis, we investigate some of the models that are used to describe these relationships. This thesis can be divided into two main parts. The first part focuses on investigating the theoretical properties of several neutral tree models that are often considered in phylogenetics and population genetics studies, such as the Yule–Harding model, the proportional to distinguishable arrangements and the Kingman coalescent models. In comparison to the first part, the other half of the thesis is more computationally oriented: we focus on developing and implementing methods of calculating gene tree probabilities of given species networks, and simulating genealogies within species networks.

O fungo entomopatogênico Beauveria felina produz as destruxinas, hexadepsipeptídeos cíclicos que apresentam diversas atividades biológicas, como por exemplo: atividade inseticida, fitotóxica, citotóxica contra células tumorais, atividade antiviral contra o vírus da hepatite B, dentre outras. Devido à atividade inseticida das destruxinas, os fungos que as produzem têm grande importância econômica. Assim, o objetivo deste trabalho foi realizar a otimização das condições de crescimento e produção das destruxinas pelo fungo Beauveria felina utilizando diferentes meios de cultivo, a fim de se isolar destruxinas em maiores quantidades para a avaliação de seu potencial tóxico. Foram utilizados métodos de planejamento experimental e análise multivariada para a otimização das condições de crescimento, resultando em três condições ótimas de cultivo para cada um dos meios de cultura MF, PDB e SBD. Em todas as condições ótimas de cultivo foram observadas destruxinas conhecidas, desconhecidas e destruxinas que não foram isoladas anteriormente de Beauveria felina. O cultivo de Beauveria felina no meio PDB foi o que mais apresentou destruxinas desconhecidas (5). Em seguida foi realizada uma otimização das condições de análise cromatográfica de destruxinas por CLAD-DAD-DELE-EM e a validação deste método. Uma das frações obtidas do meio de cultura de Beauveria felina apresentou atividade vermífuga contra Haemonchus contortus. Duas de suas frações purificadas, P1 (destruxina Ed1 - m/z 625 e pseudodestruxina B ou pseudodestruxina C - isobáricas, m/z 669) e P7 (destruxina D ou hidroxihomodestruxina B ou roseotoxina C - isobáricas, m/z 623), foram ativas contra o carrapato bovino Rhipicephalus microplus. / The entomopathogenic fungus Beauveria felina produces destruxins, cyclic hexadepsipeptides which have several biological activities, such as insecticidal, phytotoxic, cytotoxic against tumor cells, antiviral activity against hepatitis B virus, among others. Because of the insecticidal activity of destruxins, fungi that produce them have a considerable economic importance. Therefore the aim of this study was to optimize the conditions for the growth of Beauveria felina and its production of destruxins by using different culture media, in order to isolate larger quantities for the evaluation of their toxic potential. Experimental design and multivariate analysis were used for the optimization of growth conditions, resulting in three conditions for optimum growth for each of the culture media MF, PDB and SBD. Both known and unknown destruxins were observed in each of the optimal conditions, along with destruxins that were not previously isolated from Beauveria felina. The cultivation of Beauveria felina in PDB was the one that showed the largest amount of unknown destruxins (5). We then carried out an optimization of the chromatographic analysis of destruxins by HPLC-PDA-ELSD-MS and the validation of this method. One of the fractions obtained from the culture medium of Beauveria felina showed anthelmintic activity against Haemonchus contortus, while two of its purified fractions, P1 (destruxin Ed1 - m/z 625 and pseudodestruxin B or pseudodestruxin C - isobaric m/z 669) and P7 (destruxin D or hydroxyhomodestruxin B or roseotoxin C - isobaric m/z 623), were active against the cattle tick Rhipicephalus microplus.

A lack of available data exists regarding environmental factors related to prescription drug abuse (PDA), which could explain the ineffectiveness of efforts to reduce PDA in Florida. Prescription drug abuse among adults older than age 18 varies with the level of education achieved, and these metrics potentially reflect socioeconomic differences. The purpose of this quantitative study was to examine the connections between contextual aspects of prescription opioid abuse among Florida's middle and high school students to understand youth PDA in relation to their environments. This study consisted of a secondary analysis of existing PDA data (dependent variable) in relation to a number of independent variables, including the incidence of female-headed households, the nature of residential environment, adherence to religious precepts, and students' ability to achieve educational goals. Incidence of female-headed households, the nature of residential environment, and adherence to religious precepts were not found to predict youth PDA. The only finding of significance was that PDA predicted lowered students' ability to achieve educational goals (p = .015). Data collected from this study might be used by school counselors and administrators when developing drug abuse prevention, intervention, and educational programs, thereby leading to positive social change in helping to reduce PDA among youth.

<p>On radar level gauges currently shipped by Saab Rosemount, some adjustments of the unit's parameters has to be performed in the field. Presently, this is a cumbersome procedure; the operator has to be very close to the gauge and he either has to carry with him a bulky configuration unit or use a basic control unit on the gauge. A wireless solution, where a portable device and a receiver replace the control unit, would both allow the operator to work from a distance and eliminate the need for the bulky device. </p><p>The most conspicuous restraint for such a solution is a very low allowed power dissipation. The reason for this is that some gauges do not have a separate power supply, but are fed directly off the communication bus. A viable solution should also be commercially available and robust enough to operate in an industrial environment. </p><p>To meet these requirements both a theoretical and a practical assessment was conducted, where the two techniques for wireless communication, IrDA, and Bluetooth, was given special consideration. As for the portable device, the market for hand-held computers was investigated and ultimately a PDA from Palm was selected for this project. Together with this PDA, a prototype for each of the two wireless techniques was tested to ascertain their performance with respect to power dissipation, communication range, and communication robustness. </p><p>This investigation revealed that Bluetooth could be used over a much greater distance than IrDA and it did also provide a more robust solution overall. IrDA is nonetheless also a competent technique, and has its primary advantage in terms of much lower power dissipation compared to Bluetooth.</p>

<p>Today, information and communication technology is not only for professional use, but also for private tasks. In this thesis, the use of such technology for managing family information flow is investigated. Busy family life today, with school, work and leisure activites, makes coordination and synchronisation a burden. In what way cell-phones and Internet provides a support for those tasks is investigated, together with proposals for future technology.</p><p>The problem with coordination and synchronisation were found to be managed by a bulletin board placed at a central point at home. Besides the bulletin board, we found that calendars, shopping lists, and to-do lists are important. The families we investigated in field studies were all intensive users of both Internet and cell-phones.</p><p>Since the bulletin board played such an important role in the family life, we equipped families with cameras to be able to track what happened at those places with help of photo diaries. The field studies revealed that each family had their own unconscious procedure to manage the flow of notes on the bulletin board.</p><p>With technology, new problem will emerge. We investigated how notes on typical family bulletin boards may be visualised on a computer screen, and compared click-expand, zoom-pan and bifocal interfaces. The click-expand interface was substantially faster for browsing, and also easier to use.</p><p>An advantage of information and communication technology is that it may provide possibilities for multiple interfaces to information, and not only different terminals but also from different places. At home, a digital refrigerator door or a mobile web tablet; at work or at school, a conventional computer; when on the move, a cell-phone or a PDA. System architecture for these possibilities is presented.</p> / Report code: LiU-TEK-LIC-2004:39.

<p>Internetanvändning med mobila enheter såsom PDAs och smartphones är idag vanligt. De flesta webbsidor är dock designade för att visas på stationära datorer med stora skärmar. När användare med mobila enheter besöker webbsidorna uppstår ofta användbarhetsproblem som i främsta hand kan kopplas till de mobila enheternas små skärmar. </p><p>Syftet med denna studie var att undersöka vilka faktorer som är viktiga att ta hänsyn till, då en söksida på Internet skall anpassas för att presenteras på mobila enheter med små skärmar.</p><p>Studien bestod av tre olika faser, där den första var en litteraturstudie som syftade till att samla in information som berör design och omvandling av webbsidor mot små skärmar. I den andra fasen utvecklades två olika prototyper av en befintlig söksida på Internet, anpassade för små skärmar. I den tredje och sista fasen, utvärderades prototyperna på ett antal respondenter. Utvärderingarna bestod av uppgiftsbaserade utvärderingar med efterföljande intervjuer. Därefter analyserades resultatet av utvärderingarna utefter begrepp som behandlats i uppsatsens teoretiska del.</p><p>En slutsats som kunde dras var att flera av de designriktlinjer som idag finns för små skärmar även är lämpliga för en söksida. Studien har även resulterat i egna rekommendationer för hur en söksida kan migreras till mobila enheter med små skärmar för att vara användbar. En av dessa är att resultaten av en sökning bör presenteras kompakt så att användarna kan få en god överblick och inte behöva skrolla för mycket för att läsa dem.</p>

<p>Mobila applikationer har under senare år fått ett allt större användningsområde. En typ av applikation som blir allt populärare är mobila kartapplikationer. Denna uppsats belyser problematik kring mobila kartapplikationer och den brist som idag råder i fråga om att skapa gränssnitt med bra användbarhet till denna typ av applikationer. Uppsatsen identifierar och undersöker interaktionselement som används i två befintliga mobila kartapplikationer genom en kvalitativ studie. En inledande studie genomfördes för att identifiera interaktionselement i två befintliga mobila kartapplikationer; Yahoo! Go och Eniros mobila karttjänst.  Kartapplikationerna testades i en emulator för mobiltelefon av mindre modell eftersom det ansågs vara svårare att uppnå bra användbarhet desto mindre skärmytan i enheten är. Utifrån teori inom området kategoriserades interaktionselement in i fyra områden. Områdena var: navigering, innehåll, layout och feedback. Teorin sammanfattades i en teoretisk referensram. Undersökningen återkopplade även till användbarhet då det i uppsatsens syfte ingick att lyfta fram designriktlinjer, som utifrån användares perspektiv kan göra mobila kartapplikationer mer lätthanterliga. I studien samlades data in genom ett uppgiftsbaserat test där respondenterna uppmanades att tänka högt i syfte att fånga deras känslor kring gränssnittens olika interaktionselement. Det uppgiftsbaserade testet följdes av en intervju, där frågor som återkopplade till interaktionselement och användbarhet i de testade gränssnitten ställdes. Intervjun återkopplade även till de problem och kommentarer som respondenterna yttrat under testet. Resultatet av observationen och intervjuerna analyserades och ställdes mot den teoretiska referensramen och slutsatser kunde dras för hur olika interaktionselement påverkar i fråga om användbarhet i mobila kartapplikationer. De slutsatserna som kunde härledas var bland annat att scroll bör undvikas och att på vilket sätt knappsatsen utnyttjas av systemet påverkar användbarhet. Slutsatserna sammanställdes och presenterades som riktlinjer för att uppnå en högre användbarhet i mobila kartapplikationer.</p>

På sektionen Flygsystem/Teknik på Saab Aerotech har man gedigen erfarenhet av att ta fram underhållsinstruktioner för försvarsmaktens flygande system. En mängd olika typer av underhållsinstruktioner produceras inom avdelningen. Volymen på instruktionerna är stor och revisionsfrekvensen på olika delar varierar mellan 20 gånger per år till en gång var 18:de månad. Gemensamt för alla är att de presenteras och distribueras i tryckformat. Försvarsmakten har börjat digitalisera distributionen, men då instruktionen ska användas skrivs den ut på papper. Nu finns tekniken för att göra underhållsinstruktionerna mer intelligenta ur användarens perspektiv. Alltså att ge användaren ett effektivare och bättre verktyg. För sektionen är det mycket viktigt, inte minst ur affärssynpunkt, att följa med i teknikutvecklingen. Det är också viktigt att erbjuda kunden en produkt där all information som kan behövas finns samlad på ett smidigare sätt än i dagens system. Syftet med det här examensarbetet är att undersöka hur en publikation kan utvecklas och förbättras genom att utnyttja interaktivitet och multimedia; beskriva vilka krav produktionen av en sådan publikation ställer på hårdvara, mjukvara och personalkompetens; samt slutligen ta fram en prototyppublikation för handdator. Idéer om hur prototypen skulle kunna se ut utvecklades genom en användarcentrerad metod. Både slutanvändarna av publikationen samt producenterna av den analyserades liksom de bägge gruppernas uppgifter. Dessa idéer renodlades och prototypen utvecklades. Resultatet är en prototyp för hur en digital publikation kan se ut samt en beskrivning av vilka möjliga fördelar den ger användarna. Resultaten av analysen och erfarenheterna från prototyparbetet ledde fram till en idé om hur en utvecklingsprocess för strukturerad teknisk information kan se ut, samt vilka krav detta kommer att ställa på utvecklarna.