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Aujourd’hui, les constructeurs automobiles continuent de chercher les technologies renouvelables face à la pénurie d’énergie et les problèmes d’émission de polluants. Un moyen important pour optimiser l’économie de carburant et réduire les émissions polluantes des moteurs à allumage commandés est le concept ‘downsizing’. Cependant, ce concept est limité par le phénomène de cliquetis dû aux conditions de haute température et haut pression. Dans cette étude, le contrôle de la concentration d’oxygène dans l’air est proposé. Car d’une part, la combustion enrichie en oxygène permet d’améliorer la densité de puissance de moteur avec le même niveau de pression d’admission. Cela permet soit de ‘booster’ la combustion pour augmenter la puissance du moteur ou de l’activer lorsque le moteur fonctionne à faible charge ou dans des conditions de démarrage à froid. D’autre part, une faible concentration en oxygène dans l’air (ou dilution de N2) par un système membranaire peut être considérée comme une alternative à la recirculation des gaz d’échappement. Les expériences ont été effectuées dans un moteur monocylindre ‘downsizing’ avec différents taux d’oxygène et richesse. L’étude de l’impact du contrôle de la concentration d’oxygène sur les caractéristiques de combustion et d’émissions a été effectuée pour plusieurs charges en fonctionnement optimum pour limiter la consommation spécifique de carburant. L’effet de la concentration en oxygène sur les caractéristiques de combustion du moteur a été simulé en utilisant le logiciel commercial AMESim avec le modèle de combustion développé par IFP-EN. En mettant en oeuvre des corrélations de la vitesse de combustion laminaire, déterminées au préalable durant ce travail, et délai d’auto-inflammation, les pressions dans les cylindres sont parfaitement calibrés avec une erreur maximale inférieure à 2% et l’intensité du cliquetis a pu être prédite. / Nowadays, car manufacturers continue to lead researches on new technologies facing to the energy shortage and pollutant emission problems. A major way to optimise fuel economy and reduce pollutant emissions for Spark-Ignition (SI) engines is the downsizing concept. However, this concept is unfortunately limited by ‘knock’ phenomena (abnormal combustion) due to high temperature and high pressure in-cylinder conditions. In the present study, control the oxygen concentration in air is proposed. Indeed, on the one hand, oxygen-enriched combustion can improve engine power density with the same intake pressure level. Thus, oxygen-enriched combustion can be used either as a booster to increase engine output or as a combustion enhancer when the engine operates at low loads or in cold start conditions. On the other hand, low oxygen concentration in air (or N2 dilution) can be considered as an alternative to exhaust gas recirculation (EGR). The experiments were carried out in a downsized single-cylinder SI engine with different rates of oxygen and equivalence ratios. The study of the impact of controlling oxygen concentration on the combustion characteristics and emissions was performed at several loads by optimizing the spark advance and the intake pressure to maintain the load and obtain a minimum value of indicated Specific Fuel Consumption (SFC). The effect of oxygen concentration on the engine combustion characteristics was simulated by using the commercial software AMESim, with the combustion model developed by IFP-EN. By implementing correlations for the laminar burning velocity, determined previously during this study, and auto-ignition delay data base, the in-cylinder pressures were perfectly calibrated with a maximum pressure relative error less than 2%, and the knock intensity was predicted.

Au cours d'une étude sur le contrôle transcriptionnel du gène de l'alpha-foetoprotéine, le laboratoire s'était intéressé aux facteurs de transcription de la famille SP/KLF et S. Scohy avait découvert une séquence définissant un nouveau membre: SP6.<p><p>Afin de déterminer la structure du gène chez la souris, nous avons isolé un fragment génomique contenant la totalité du gène et nous l'avons séquencé. Une analyse informatique de cette séquence, l'isolement d'ESTs ainsi qu'une expérience d'extension d'amorce, nous ont permis d'affirmer que le gène Sp6 murin possède deux exons, générant une protéine de 376 acides aminés à partir d'un ATG repéré au début de l'exon 2.<p>En même temps, des travaux réalisés sur un gène nommé epiprofin ont été publiés (Nakamura et al. 2004). Ce gène s'est avéré correspondre au gène Sp6 car il code pour la même protéine. Les exons 2 sont en effet identiques, seuls les exons 1 diffèrent.<p>Nos études sur l'expression du gène Sp6 ont indiqué qu'elle est ubiquiste mais que c'est durant le développement embryonnaire, et surtout pendant les stades les plus tardifs de celui-ci, qu'il est le plus exprimé. Cette expression se localise surtout au niveau des dents, de l'épithélium olfactif, du cerveau, des bourgeons de membres et des follicules pileux de l'embryon. A l'état adulte, l'expression de Sp6 se réduit fortement dans tous les tissus; seuls les poumons présentent un taux d'expression relativement important.<p>Ce travail a également permis de mettre en évidence l'existence d'un transcrit non-codant issu d'une transcription antisens du locus Sp6 et dont le premier exon inclu la totalité de l'exon 2 du gène Sp6. Nous l'avons appelé Sp6os et avons montré que son expression est absente dans de nombreux tissus et est très faible dans les tissus où on détecte le transcrit. Une comparaison de l'expression des transcrits Sp6 et Sp6os nous a permis d'imaginer un rôle pour Sp6 dans le développement et une possible modulation de son activité, par Sp6os, dans certains tissus.<p><p>Afin de préciser la fonction du locus Sp6, nous l'avons invalidé chez la souris. Les mutants Sp6-/- se sont avérés viables mais présentent des anomalies dans tous les tissus où Sp6 est le plus fortement exprimé. En effet, ils n'ont ni pelage, ni vibrisse et montrent des anomalies des dents, des membres et des poumons. Nous avons également noté une dérégulation importante de l'apoptose (et parfois aussi de la prolifération cellulaire) chez ces souris Sp6-/-. / Doctorat en sciences, Spécialisation biologie moléculaire / info:eu-repo/semantics/nonPublished

This study has been performed at Powertrain Engineering Sweden AB (PES), a fully owned subsidiary of Volvo Cars Group, which is constantly working to develop and improve internal combustion engines. As part of this work, durability tests are performed to analyse the impact of wear on the engines. At present, there is a strong focus on visual inspections after the engines have undergone durability tests. PES wants to develop a method where collected data from these tests can be used to explain how the phenomenon of knocking and the control of lambda changes over time. The study analyses one specific durability test and investigates the methodology of data analysis by using the open-source software platform Sympathy for Data, with an add-on developed by Volvo Cars Group, for data management, visualisation and analysis. To execute the analysis, engine parameters that affect these systems as well as parameters suitable to use as response variables are identified through literature studies of internal combustion engine fundamentalsas well as internal material, and knowledge acquired at the company. The result is presented in the form of an analysis generated by the node for partial least squares regression (PLSR) which is pre-programmed in Sympathy for Data as well as the images and graphs obtained as output. For knock, the signal for the final ignition angle was found to be suitable to use as the response variable in the PLSR. A suitable response variable for lambda was more difficult to identify, this is why both signals for the measured lambda and lambda adaptation are analysed. Studies of the internal material and knowledge highlighted the fact that several engine subsystems are highly dependent on each other and that even deeper research would be necessary to fully understand the process and identify the primary cause for the variations observed in the generated models. However, partial least squares regression was performed using parameters derived from literature reviews as input (predictors) in order produce regression models to explain the variance in sought response. Well-fitting models could be created with a varying number of latent variables needed for the different responses. The output obtained from the PLSR enables further studies of the specific cases as well as the methodology itself, hence, increase the use of data analysis with the help of the software used in the department for durability testing at PES. / Denna studie är utförd hos Powertrain Engineering Sweden AB (PES), vilka är ett helägt dotterbolag till Volvo Cars Group, som arbetar med att ta fram och förbättra förbränningsmotorer. En del i detta arbete är att genomföra långtidstest för att analysera hur motorernas egenskaper ändras vid förslitning över tid. I nuläget ligger stort fokus på visuella inspektioner efter att motorerna genomgått långtidstester. PES önskar utveckla en metod där redan insamlad data som registrerats i dessa tester kan förklara hur fenomenet knack och regleringen för lambda förändras över tid. Studien är genomförd i form av en fallstudie av ett specifikt långtidstest där den öppna programvaran Sympathy for Data, tillsammans med det av Volvo Cars Group utvecklade tillägget, används för datahantering, visualisering och analys. Studien undersöker också metodiken för dataanalys med nämnd programvara. För att genomföra detta identifieras motorparametrar som påverkar de undersökta systemen samt parametrar som lämpar sig att användas som responsvariabler i en regressionsmodell. Dessa parametrar togs fram genom litteraturstudier om de fundamentala delarna i en förbränningsmotor samt från företaget förvärvad intern kunskap kring systemen. Resultatet presenteras i form av en analys genomförd med den, i Sympathy for Data, förprogrammerade noden för partial least squares regression(PLSR) samt de bilder och grafer som erhålls. För knack visade det sig att den slutliga tändningsvinkeln var lämplig att använda som respons i PLSR-modellen. En lämplig responsvariabel för lambda var mer svåridentifierad, detta förklarar varför signalerna för uppmätt lambda och lambda adaption analyseras. Inläsning av internt material och grundläggande information om förbränningsmotorer visade att delsystem i ottomotorn är beroende och påverkas av varandra vilket innebär att mer ingående studier i dessa delsystem är nödvändigt för att förstå hela processen och hitta grundorsakerna till variationerna som påvisas för responssignalerna. Vidare utfördes PLSR med de parametrar som härletts från litteraturstudier som indatasignaler (prediktorer) för att skapa en regressionsmodell som förklarar variansen i sökta responssignaler. Beroende av responssignal krävdes varierande antal latenta variabler för att uppnå en tillräckligt precis modell. Resultatet från PLSR möjliggör vidare forskning inom området och metoden som använts och har på så sätt möjliggjort för fortsatt utveckling. Detta i sin tur kan öka användandet av dataanalys med hjälp av den programvara som används vid avdelningen för långtidstest hos PES.

The door lock - a key function in every modern home, as well as a product which is today undergoing drastic change. The digital revolution has not left the door lock untouched, and there is today a wide variety of digital door locks utilizing technologies ranging from touch displays to fingerprint readers. The premises of the project was to try a different approach to the digital door lock and implement it schoolyard-style using a secret knock sequence, set by the user. The secret sequence would consist of two elements, both a rhythmical and a positional pattern. To unlock the door, the user would therefore need to simultaneously knock the correct rhythm and knock at the correct positions. To record and analyze the knock vibrations, piezo electric sensors connected to an Arduino Uno were used. To unlock the door, a small servo motor, two gears and a timing belt were used to turn the lock turning knob . Despite a short time frame and hardships due to the limitations caused by the coronavirus outbreak, a fully functional prototype which fulfilled both reliability and consistency was achieved. It could with good consistency recognize the test sequence, which was the intro rhythm to ”We Will Rock You” knocked in a square pattern. But even with flawless functionality, the conclusion would have been the same. The security of the system may be exceptional from a technical perspective, but it falls flat when the human factor is taken into account. The ability for a potential burglar to simply watch as one executes the secret knock is too much of a security hazard for the system to ever be considered as a competitor to other alternatives. The usage of the system is therefore better suited for applications where the thrill of using the product is more important than the actual security of it. / Dörrlåset - en grundläggande funktion i varje modernt hem, och samtidigt en produkt som idag genomgår drastisk förändring. Som resultat av den digitala revolutionen finns det idag en uppsjö av olika digitala dörrlås som utnyttjar allt från touchskärmar till fingeravtrycksläsare. Syftet med projektet var att testa en annorlunda tappning på det digitala dörrlåset, och förverkliga något många hade drömt om i barndomen - ett dörrlås aktiverat genom ett eget hemligt knackningsmönster. Det hemliga knackningsmönstret skulle då bestå av både ett rytmiskt och ett positionellt mönster. Därmed skulle den som ville öppna dörren behöva knacka både rätt rytm, och på rätt ställen på dörren. För att spela in och analysera vibrationerna från knackningarna användes piezoelektriska sensorer kopplade till en Arduino Uno. Mekanismen som styrde själva upplåsningen bestod av en liten servomotor, två kugghjul och en kuggrem som kopplade samman det hela. Trots en begränsad tidsram och motgångar orsakade av coronaviruset lyckades en fullt fungerande prototyp med hög pålitlighet färdigställas. Den kunde med hög tillförlitlighet känns igen testsekvensen, som var introrytmen till ”We Will Rock You” knackat i mönstret av en kvadrat. Men även med felfri prestanda hade slutsatsen varit densamma. Säkerheten för systemet må vara exeptionell ur ett rent tekniskt perspektiv, men den faller platt när den mänskliga faktorn tas med i beräkningen. Risken att en potentiell inbrottstjuv helt enkelt tittar på när någon knackar det hemliga mönstret är för stor för att systemet någonsin skulle kunna betraktas som en seriös konkurrent till andra digitala dörrlås. Produkten är därmed bäst lämpad för användningsområden där nöjet av att använda den är av högre prioritet än själva säkerheten.

Ahnak ist ein ubiquitäres Protein, das an einer Vielzahl biologischer Prozesse beteiligt ist. In der Herzmuskelzelle ist Ahnak überwiegend am Sarkolemma lokalisiert und bindet an Aktin und an die regulatorischen Beta2-Untereinheit des L-Typ-Kalzium-Kanals. Das Ziel dieser Arbeit war die Funktion von Ahnak im Herzen mit Hilfe eines Knock-out-Maus-Modells und in Bindungsstudien zu untersuchen. Morphologische Untersuchungen zeigten, dass das Längenwachstum adulter Kardiomyozyten bei Ahnakdefizienz signifikant reduziert war. Die Kontraktionseigenschaften adulter isolierter Ahnak-defizienter Kardio-myozyten (im Alter von 6 Monaten) waren ebenfalls verändert. Die Kontraktions- und Relaxaktionsgeschwindigkeiten waren erhöht. Eine Erhöhung des diastolischen Kalzium-Spiegels zeigten die Kardiomyozyten schon im Alter von 3 Monaten. Diese beobachteten phänotypischen Veränderungen lassen vermuten, dass die Aktivität des L-Typ-Kalzium-Kanals erhöht ist. In dieser Arbeit konnte das PXXP-Motiv, in der C-terminalen Ahnak-Domäne, als die hochaffine Beta2-Bindungsstelle (KD ~ 60 nM) identifiziert werden. Substitution von Prolin gegen Alanin verringerte zwar die Bindung zur Beta2-Untereinheit dramatisch (KD ~ 1 µM), hob sie aber nicht auf. In weiteren Bindungsstudien zeigte sich, dass die natürlich vorkommende Missensmutation I5236T die Bindung zur regulatorischen Beta2-Untereinheit verstärkte, dagegen verminderte die PKA-abhängige Phosphorylierung der beiden Proteinpartner die Bindung. Experimente am ganzen isoliert perfundierten Herzen zeigten, dass Ahnak-Knock-Out-Herzen geringer Beta-adrenerg stimulierbar waren. Ahnak scheint wie eine physiologische Bremse des kardialen Kalzium-Kanals zu wirken. / Ahnak is an ubiquitous protein with in unique structure, which has been implicated in cell type specific functions. In cardiomyocytes, ahnak is predominantly localized at the sarcolemma and is associated with actin and with the regulatory beta2 subunit of the L-type calcium-channel. The aim of this work was to unravel the function of ahnak in the heart, using a knock-out-mouse model and binding studies. Morphological studies showed a significant decrease in the cell-length of ahnak deficient cardiomyocytes. The contractile parameters of isolated adult ahnak deficient cardiomyocytes (in the age of 6 month) were altered. The development of tension and relaxation were increased. An increase of diastolic calcium was already observed at the age of 3 month. In general the observed phenotypic changes suggested an increased activity of the L-type calcium-channel. In this study, a PXXP-motif, which locates in ahnaks C-terminus, was identified as the high affinity beta2 subunit binding site (KD ~ 60 nM). Substitution of both proline residues by alanine reduced, but did not abolish the binding (KD ~ 1 µM). Further binding studies revealed that the natural occurring ahnak missense mutation I5236T increases the binding affinity to the regulatory beta2 subunit. By contrast PKA dependant phosphorylation of both protein partners decreases the interaction. In studies with isolated perfused working heart preparations, the ahnak deficient hearts were less beta-adrenergic stimulated than hearts from wild type. Taken together ahnak seems to be a physiological brake of the cardiac calcium-channel.

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The ability of plants to sense and respond to environmental and endogenous signals is essential to their growth and development. As part of these diverse cellular functions, ubiquitin-mediated proteolysis has emerged to be an important process involved in how plant signalling pathways can be regulated in response to such cues. Of the three enzymes involved in linking ubiquitin to protein targets, E3 ubiquitin ligases are of interest as they confer substrate specificity during this ubiquitination process. The overall focal point of this research is on plant U-box (PUB) E3 ubiquitin ligases, a family that has undergone a large gene expansion possibly attributable to the regulation of biological processes unique to the plant life cycle. In Arabidopsis there are 64 predicted PUBs, many for which biological roles have yet to be determined. And as research continues to uncover PUB functions, the functional diversity in the gene family will likely expand. Specifically the focus of this research is on characterizing two ARM repeat-containing PUBs – AtPUB18 and AtPUB19. General analysis of pub18 and pub19 T-DNA insertion lines for growth defects did not yield distinct altered phenotypes. Closer inspection of selected lines showed independent gene assortment phenotypes that, with further inordinately convoluted pursuit, proved to have an AtPUB18/19-unrelated outcome. The availability of Arabidopsis microarray databases provided exploratory expression profiling as a starting point to elucidate PUB function. AtPUB19 and closely related AtPUB18 are notable for their increased expression during abiotic stresses. While condition-directed germination assays showed a decreased sensitivity to salt and ABA for pub18 pub19 double insertion lines, no related change in susceptibility to these or other abiotic stress treatments were seen with condition-directed root growth assays. Thus, this preliminary work has begun to reveal insight into the complex abiotic stress-related roles AtPUB18 and AtPUB19 have during mediation of environmental stress acclimation in Arabidopsis.

The ability of plants to sense and respond to environmental and endogenous signals is essential to their growth and development. As part of these diverse cellular functions, ubiquitin-mediated proteolysis has emerged to be an important process involved in how plant signalling pathways can be regulated in response to such cues. Of the three enzymes involved in linking ubiquitin to protein targets, E3 ubiquitin ligases are of interest as they confer substrate specificity during this ubiquitination process. The overall focal point of this research is on plant U-box (PUB) E3 ubiquitin ligases, a family that has undergone a large gene expansion possibly attributable to the regulation of biological processes unique to the plant life cycle. In Arabidopsis there are 64 predicted PUBs, many for which biological roles have yet to be determined. And as research continues to uncover PUB functions, the functional diversity in the gene family will likely expand. Specifically the focus of this research is on characterizing two ARM repeat-containing PUBs – AtPUB18 and AtPUB19. General analysis of pub18 and pub19 T-DNA insertion lines for growth defects did not yield distinct altered phenotypes. Closer inspection of selected lines showed independent gene assortment phenotypes that, with further inordinately convoluted pursuit, proved to have an AtPUB18/19-unrelated outcome. The availability of Arabidopsis microarray databases provided exploratory expression profiling as a starting point to elucidate PUB function. AtPUB19 and closely related AtPUB18 are notable for their increased expression during abiotic stresses. While condition-directed germination assays showed a decreased sensitivity to salt and ABA for pub18 pub19 double insertion lines, no related change in susceptibility to these or other abiotic stress treatments were seen with condition-directed root growth assays. Thus, this preliminary work has begun to reveal insight into the complex abiotic stress-related roles AtPUB18 and AtPUB19 have during mediation of environmental stress acclimation in Arabidopsis.