Epäsuoralla lämmöntuonnilla varustetut mikroturbiinit

Epäsuorassa lämmöntuonnissa biomassan poltto ja mikroturbiinin kiertoprosessi on erotettu toisistaan lämmönsiirtimen avulla. Tämän avulla mikroturbiiniprosessissa voidaan hyö-dyntää myös likaavia savukaasuja tuottavia polttoaineita kuten biomassaa. Prosessissa hyö-tysuhde ei nouse niin korkealle kuin kaasumaista polttoainetta käytettäessä lähinnä turbiinin alemmasta sisääntulolämpötilasta johtuen. Lämmönsiirtimen suunnittelu on erittäin tärkeässä asemassa prosessin sähköntuottohyötysuhdetta ajatellen. Mitä suurempi osa bio-massan savukaasujen lämpöenergiasta saadaan hyödynnettyä sitä suurempi on hyötysuhde. Kaupallisessa tarjonnassa on vielä hieman ongelmia juuri näistä syistä. Lämmönsiirrin ei välttämättä kestä korkeita lämpötiloja. Suuremmilla lämpötiloilla (yli 800 °C) joudutaan käyttämään seostettuja teräslaatuja tai jopa keraamisia ratkaisuja. Hyötysuhteeltaan ja in-vestointikustannuksiltaan epäsuoralla lämmöntuonnilla varustettu mikroturbiini on etuase-massa muihin teknologioihin nähden, kunhan lämmönsiirtimen materiaaliongelma ja opti-maalinen biomassan poltto ratkaistaan.

Lämmöntuotannon energiatehokkuuden parantaminen Sotek-säätiön rakennuksissa

Diplomityössä tarkastellaan lämmöntuotannon energiatehokkuuden parantamista neljässä Sotek- säätiön rakennuksessa. Työssä oli tarkoitus selvittää, minkälainen lämmitysjärjestelmä on juuri kyseiseen kiinteistöön järkevin ja investointikustannuksiltaan kannattava. Työssä käydään läpi polttoaineita, lämmöntuotanto- ja lämmönjakotapoja, sekä mietitään kannattaako rakennuksia lisäeristää. Työssä verrataan vanhojen järjestelmien hiilidioksidipäästöjä valittujen uusien järjestelmien hiilidioksidipäästöihin. Kiinteistöjen lämmitys tuottaa Suomessa noin 30 % kaikista hiilidioksidipäästöistä. Se on siis merkittävä alue, josta päästöjä voitaisiin vähentää. Tehtävänä oli laskea kaikille kiinteistöille tarkat lämmitystarpeet ja lämmitystehontarpeet käyttäen apuna Suomen rakennusmääräyskokoelmaa. Työn perusteella lämmöntuotannon energiatehokkuuden parantaminen kohteissa on järkevää ja taloudellisesti kannattavaa muuttamalla lämmöntuotanto pääosin lämpöpumpuille. Täystehoiset järjestelmät eivät tulleet investoinnillisesti kannattavaksi, eikä se ilmalämpöpumpuissa ollut edes mahdollista. Tulosten perusteella lämmitysenergian kustannuksia saatiin vähennettyä parhaiten mitoittamalla kohteisiin osatehoiset lämpöpumput. Lisälämmöneristäminen kohteissa ei taloudellisesti tullut kannattavaksi, vaikka lämmitystarve väheni. Lämmöntuotannon hiilidioksidipäästöt vähenisivät kohteissa keskimäärin noin 50 %.

Semi-automatic measurement of visual verticality perception in humans reveals a new category of visual field dependency

Previous assessment of verticality by means of rod and rod and frame tests indicated that human subjects can be more (field dependent) or less (field independent) influenced by a frame placed around a tilted rod. In the present study we propose a new approach to these tests. The judgment of visual verticality (rod test) was evaluated in 50 young subjects (28 males, ranging in age from 20 to 27 years) by randomly projecting a luminous rod tilted between -18 and +18° (negative values indicating left tilts) onto a tangent screen. In the rod and frame test the rod was displayed within a luminous fixed frame tilted at +18 or -18°. Subjects were instructed to verbally indicate the rod’s inclination direction (forced choice). Visual dependency was estimated by means of a Visual Index calculated from rod and rod and frame test values. Based on this index, volunteers were classified as field dependent, intermediate and field independent. A fourth category was created within the field-independent subjects for whom the amount of correct guesses in the rod and frame test exceeded that of the rod test, thus indicating improved performance when a surrounding frame was present. In conclusion, the combined use of subjective visual vertical and the rod and frame test provides a specific and reliable form of evaluation of verticality in healthy subjects and might be of use to probe changes in brain function after central or peripheral lesions.

An interleukin-33/ST2 signaling deficiency reduces overt pain-like behaviors in mice

Interleukin (IL)-33, the most recent member of the IL family of cytokines, signals through the ST2 receptor. IL-33/ST2 signaling mediates antigen challenge-induced mechanical hyperalgesia in the joints and cutaneous tissues of immunized mice. The present study asked whether IL-33/ST2 signaling is relevant to overt pain-like behaviors in mice. Acetic acid and phenyl-p-benzoquinone induced significant writhing responses in wild-type (WT) mice; this overt nociceptive behavior was reduced in ST2-deficient mice. In an antigen-challenge model, ST2-deficient immunized mice had reduced induced flinch and licking overt pain-like behaviors. In the formalin test, ST2-deficient mice also presented reduced flinch and licking responses, compared with WT mice. Naive WT and ST2-deficient mice presented similar responses in the rota-rod, hot plate, and electronic von Frey tests, indicating no impairment of motor function or alteration in basal nociceptive responses. The results demonstrate that IL-33/ST2 signaling is important in the development of overt pain-like behaviors.

Thick Section Laser Beam Welding of Structural Steels: Methods for Improving Welding Efficiency

Laser beam welding (LBW) is applicable for a wide range of industrial sectors and has a history of fifty years. However, it is considered an unusual method with applications typically limited to welding of thin sheet metal. With a new generation of high power lasers there has been a renewed interest in thick section LBW (also known as keyhole laser welding). There was a growing body of publications during 2001-2011 that indicates an increasing interest in laser welding for many industrial applications, and in last ten years, an increasing number of studies have examined the ways to increase the efficiency of the process. Expanding the thickness range and efficiency of LBW makes the process a possibility for industrial applications dealing with thick metal welding: shipbuilding, offshore structures, pipelines, power plants and other industries. The advantages provided by LBW, such as high process speed, high productivity, and low heat input, may revolutionize these industries and significantly reduce the process costs. The research to date has focused on either increasing the efficiency via optimizing process parameters, or on the process fundamentals, rather than on process and workpiece modifications. The argument of this thesis is that the efficiency of the laser beam process can be increased in a straightforward way in the workshop conditions. Throughout this dissertation, the term “efficiency” is used to refer to welding process efficiency, specifically, an increase in efficiency refers an increase in weld’s penetration depth without increasing laser power level or decreasing welding speed. These methods are: modifications of the workpiece – edge surface roughness and air gap between the joining plates; modification of the ambient conditions – local reduction of the pressure in the welding zone; modification of the welding process – preheating of the welding zone. Approaches to improve the efficiency are analyzed and compared both separately and combined. These experimentally proven methods confirm previous findings and contribute additional evidence which expand the opportunities for laser beam welding applications. The focus of this research was primarily on the effects of edge surface roughness preparation and pre-set air gap between the plates on weld quality and penetration depth. To date, there has been no reliable evidence that such modifications of the workpiece give a positive effect on the welding efficiency. Other methods were tested in combination with the two methods mentioned above. The most promising - combining with reduced pressure method - resulted in at least 100% increase in efficiency. The results of this thesis support the idea that joining those methods in one modified process will provide the modern engineering with a sufficient tool for many novel applications with potential benefits to a range of industries.

Kaukolämpöjohdon lämpöhäviöiden talteenotto lämpöpumpputeknologian avulla

Tämän tutkimuksen tavoitteena oli laatia tarkastelumalli, jonka perusteella pystyttäisiin analysoimaan tutkimuksessa tarkasteltavan kaukolämpöjohdon lämpöhäviöiden talteenot-toratkaisun taloudellista kannattavuutta yleisellä tasolla sekä sen mahdollisissa sovellus-kohteissa. Työssä tarkastellaan kaukolämpöjohtoa, jonka sisään on sijoitettu lämmönke-ruuputki. Lämmönkeruuputken on tarkoitus kerätä lämpöä kaukolämpöjohdon vaipasta sekä pitää vaipan lämpötilaa ympäristön lämpötilaa matalampana, jolloin johdon ulkopuo-lisia lämpöhäviöitä ei synny. Tarkastelumalli laadittiin perustuen lämpöpumppuprosessin ja kaukolämpöverkoston yleisiin mitoitusperiaatteisiin sekä ratkaisuun liittyvien järjestelmien osalta kerättyihin tarkas-teluhetkeä edustaviin kustannustietoihin. Tarkastelumallista laadittiin Excel-laskentataulukkona, jota voidaan tulevaisuudessa soveltaa järjestelmän sovelluskohdekoh-taiseen tarkasteluun sekä mitoitukseen. Lasketut takaisinmaksuajat osoittautuivat kaikissa tarkastelluissa tapauksissa järjestelmien arvioitua teknistä käyttöikää lyhyemmäksi. Järjestelmällä voisi olla tietynlaisissa sovellus-kohteissa myös strateginen, kaukolämpöliiketoiminnan riskejä vähentävä merkitys.

Thermal modelling of commercial lithium-ion batteries

The accelerating adoption of electrical technologies in vehicles over the recent years has led to an increase in the research on electrochemical energy storage systems, which are among the key elements in these technologies. The application of electrochemical energy storage systems for instance in hybrid electrical vehicles (HEVs) or hybrid mobile working machines allows tolerating high power peaks, leading to an opportunity to downsize the internal combustion engine and reduce fuel consumption, and therefore, CO2 and other emissions. Further, the application of electrochemical energy storage systems provides an option of kinetic and potential energy recuperation. Presently, the lithium-ion (Li-ion) battery is considered the most suitable electrochemical energy storage type in HEVs and hybrid mobile working machines. However, the intensive operating cycle produces high heat losses in the Li-ion battery, which increase its operating temperature. The Li-ion battery operation at high temperatures accelerates the ageing of the battery, and in the worst case, may lead to a thermal runaway and fire. Therefore, an appropriate Li-ion battery cooling system should be provided for the temperature control in applications such as HEVs and mobile working machines. In this doctoral dissertation, methods are presented to set up a thermal model of a single Li-ion cell and a more complex battery module, which can be used if full information about the battery chemistry is not available. In addition, a non-destructive method is developed for the cell thermal characterization, which allows to measure the thermal parameters at different states of charge and in different points of cell surface. The proposed models and the cell thermal characterization method have been verified by experimental measurements. The minimization of high thermal non-uniformity, which was detected in the pouch cell during its operation with a high C-rate current, was analysed by applying a simplified pouch cell 3D thermal model. In the analysis, heat pipes were incorporated into the pouch cell cooling system, and an optimization algorithm was generated for the estimation of the optimalplacement of heat pipes in the pouch cell cooling system. An analysis of the application of heat pipes to the pouch cell cooling system shows that heat pipes significantly decrease the temperature non-uniformity on the cell surface, and therefore, heat pipes were recommended for the enhancement of the pouch cell cooling system.

A preliminary study of the MDH variability in Lemna minor - Lemna turionifera /

Lemna minor is a small aquatic polyploid angiosperm which reproduces apomictically and has a worldwide distribution. This study was vmdertaken to characterize the extent and nature of phenotypic variability. The techniques of starch gel electrophoresis were used in this investigation and. MDH phenotypes of several populations from Ontario, USA and Africa were examined and compared. Heat stability, molecular weight and cell fractionation analyses were also done to identify locus specific MDH bands. The results of the population surveys suggest that there is little genetic variability present both within and between Lemna minor/Lemna turionifera . Evidence of correlation of physiological and seasonal variation patterns was found.

Passive Solar Building Design Using Genetic Programming

Passive solar building design is the process of designing a building while considering sunlight exposure for receiving heat in winter and rejecting heat in summer. The main goal of a passive solar building design is to remove or reduce the need of mechanical and electrical systems for cooling and heating, and therefore saving energy costs and reducing environmental impact. This research will use evolutionary computation to design passive solar buildings. Evolutionary design is used in many research projects to build 3D models for structures automatically. In this research, we use a mixture of split grammar and string-rewriting for generating new 3D structures. To evaluate energy costs, the EnergyPlus system is used. This is a comprehensive building energy simulation system, which will be used alongside the genetic programming system. In addition, genetic programming will also consider other design and geometry characteristics of the building as search objectives, for example, window placement, building shape, size, and complexity. In passive solar designs, reducing energy that is needed for cooling and heating are two objectives of interest. Experiments show that smaller buildings with no windows and skylights are the most energy efficient models. Window heat gain is another objective used to encourage models to have windows. In addition, window and volume based objectives are tried. To examine the impact of environment on designs, experiments are run on five different geographic locations. Also, both single floor models and multi-floor models are examined in this research. According to the experiments, solutions from the experiments were consistent with respect to materials, sizes, and appearance, and satisfied problem constraints in all instances.

Infrared thermography: A non-invasive window into thermal physiology

Infrared thermography is a non-invasive technique that measures mid to long-wave infrared radiation emanating from all objects and converts this to temperature. As an imaging technique, the value of modern infrared thermography is its ability to produce a digitized image or high speed video rendering a thermal map of the scene in false colour. Since temperature is an important environmental parameter influencing animal physiology and metabolic heat production an energetically expensive process, measuring temperature and energy exchange in animals is critical to understanding physiology, especially under field conditions. As a non-contact approach, infrared thermography provides a non-invasive complement to physiological data gathering. One caveat, however, is that only surface temperatures are measured, which guides much research to those thermal events occurring at the skin and insulating regions of the body. As an imaging technique, infrared thermal imaging is also subject to certain uncertainties that require physical modeling, which is typically done via built-in software approaches. Infrared thermal imaging has enabled different insights into the comparative physiology of phenomena ranging from thermogenesis, peripheral blood flow adjustments, evaporative cooling, and to respiratory physiology. In this review, I provide background and guidelines for the use of thermal imaging, primarily aimed at field physiologists and biologists interested in thermal biology. I also discuss some of the better known approaches and discoveries revealed from using thermal imaging with the objective of encouraging more quantitative assessment.

‘Designer Vaginas': The Representation of Female Genitals on Canadian Cosmetic Surgeons' Websites

This thesis critically examines the online marketing tactics of 10 (English language) Canadian cosmetic surgery clinics’ websites that offer Female Genital Cosmetic Surgery (FGCS), specifically, labiaplasty (labial reduction) and vaginoplasty (vaginal tightening). Drawing on a qualitative Multimodal Critical Discourse Analysis (MCDA) and a feminist-informed social constructionist framework (Lazar, 2007), I examine how FGCS discourses reiterate and reinforce heteronormative sexual scripts for women, and impose restrictive models of femininity through the pathologization of genital diversity and the appropriation of postfeminist and neoliberal discourses of individual choice and empowerment. I explore feminist analyses of the links between FGCS and contemporary Western women’s postfeminist subjectivity, and the reconfiguration of women’s sexual agency, to better understand what these contemporary shifts may mean for women’s sexual anxiety and expression. My analysis highlights several discourses that organize the online marketing material of Canadian FGCS websites, including: the pathologization of genital diversity; restrictive models of femininity; heteronormative sexual scripts; neoliberal and post-feminist rhetorics of individual choice and empowerment; and psychological and sexual transformation. Overall, these discourses undermine acceptance of women’s genital diversity, legitimize the FGCS industry and frame FGCS as the only viable solution to alleviate women’s genital and sexual distress despite the lack of evidence regarding the long-term benefits and risks of these procedures, and the recommendations against FGCS by professional medical organizations.

Contrôle postural et intégration sensorielle chez l’enfant en santé, chez l’adolescent atteint du syndrome Gilles de la Tourette ainsi que chez l’adulte atteint de la maladie de Huntington

Le contrôle postural et la perception des limites de la stabilité sont des processus complexes qui nécessitent le traitement et l’intégration d’informations sensorielles multimodales. Pendant l’enfance, le développement de la stabilité posturale s’effectue de façon non-monotonique. Plusieurs auteurs ont suggéré que ce profil non linéaire serait provoqué par une période de recalibration des systèmes sensoriels. Cette phase, nommée période de transition, est observée vers l’âge de 6-7 ans. Nous disposons toutefois de très peu d’information sur le rôle spécifique des afférences et des mécanismes d’intégration sensorielle au cours du développement postural. Les dysfonctions dans les noyaux gris centraux, telles que ceux observés dans la maladie de Parkinson, ont été associées à divers déficits dans le contrôle de la posture, dans le traitement et l’intégration sensoriel plus particulièrement, au niveau des informations proprioceptives. De plus, les limites fonctionnelles de la stabilité posturale des personnes atteintes de la maladie de Parkinson sont significativement réduites. Cependant, les connaissances concernant comment certaines pathologies des noyaux gris centraux, telles que le syndrome Gilles de la Tourette (SGT) et la maladie de Huntington (MH) affectent la capacité d’utiliser les informations sensorielles pour contrôler la posture demeurent à ce jour, incomplètes. Cette thèse porte sur le rôle des noyaux gris centraux dans les processus de traitements et d’intégration sensorielle, particulièrement les afférences proprioceptives dans le contrôle de la posture au cours du développement de l’enfant en santé, atteint du SGT et chez l’adulte atteint de la MH avec et sans symptôme clinique. Notre protocole expérimental a été testé chez ces trois populations (enfants en santé, SGT et MH). Nous avons utilisé des mesures quantitatives à partir de données issues d’une plateforme de force afin d’évaluer les ajustements posturaux dans les limites de la stabilité posturale. Les participants devaient s’incliner le plus loin possible dans quatre différentes directions (avant, arrière, droite et gauche) et maintenir l’inclinaison posturale maximale pendant 10 secondes. Afin de tester la capacité à traiter et à intégrer les informations sensorielles, la tâche expérimentale a été exécutée dans trois conditions sensorielles : 1) yeux ouverts, 2) yeux fermés et 3) yeux fermés, debout sur une mousse. Ainsi, la contribution relative de la proprioception pour le contrôle postural augmente à travers les conditions sensorielles. Dans la première étude, nous avons évalué la capacité à traiter et à intégrer les informations sensorielles avant (4 ans) et après (8-10 ans) la période de transition comparativement aux adultes. Dans la deuxième et la troisième étude, nous avons également évalué le traitement et l’intégration des informations sensorielles chez les patients atteints de désordres des noyaux gris centraux. La deuxième étude portera spécifiquement sur les adolescents atteints du SGT et la troisième, sur la MH avant et après l’apparition des symptômes cliniques. En somme, les résultats de la première étude ont démontré que la performance des enfants est affectée de façon similaire par les différentes conditions sensorielles avant et après la période de transition. Toutefois, le profil de développement des mécanismes responsables des ajustements posturaux de l’axe antéropostérieur est plus précoce comparativement à ceux de l’axe médiolatéral. Ainsi, nos résultats ne supportent pas l’hypothèse de la période de recalibration des systèmes sensoriels pendant cette période ontogénétique mais suggèrent que la période de transition peut être expliquée par la maturation précoce des mécanismes d’ajustements posturaux dans l’axe antéropostérieur. Dans l’ensemble, les résultats de nos études chez les populations atteintes de désordres des noyaux gris centraux (MH et SGT) démontrent non seulement qu’ils ont des déficits posturaux mais également que les ajustements posturaux dans les deux axes sont affectés par les conditions sensorielles. Pour la première fois, nos études démontrent des déficits globaux de traitements et d’intégration sensorielle accentués pour les signaux proprioceptifs. Ces résultats sont similaires à ceux observés dans la maladie de Parkinson. De plus, les adolescents atteints du SGT éprouvent également des troubles posturaux marqués dans la condition visuelle ce qui suggère des déficits d’intégrations visuelles et/ou multimodaux.

Vulnérabilité à la chaleur dans le contexte des changements climatiques.

Thèse réalisée en cotutelle avec Université Paris 11 (Ecole Doctorale 420)

Activation of Progesterone Receptor by ATP

Progesterone-receptor complex from freshly prepared hen oviduct cytosol acquired the ability to bind to isolated nuclei, DNA-cellulose and ATP-Sepharose when incubated with 5-10 mM ATP at 4°C. The extent of this ATP-dependent activation was higher when compared with heat-activation achieved by warming the progesterone- receptor complex at 23 °C. The transformation of progesterone-receptor complex which occurred in a time-dependent manner was only partially dependent on hormone presence. The ATP effect was selective in causing this transformation whereas ADP, AMP and cAMP failed to show any such effect. The non-hydrolizable analogs of ATP, adenosine 5'-[a,/3-methylene]triphosphate and adenosine 5-[/l,y-imido]triphosphate were also found to be ineffective. Presence of 10 mM sodium molybdate blocked both the ATP and the heat-activation of progesterone-receptor complex. Mn" or Mg` had no detectable effect on the receptor activation but the presence of Ca" increased the extent of ATP-activation slightly. EDTA presence (> 5 mM) decreased the extent of receptor activation by about 40 % and was, therefore, not included in the buffers used for activation studies. Divalent cations were also ineffective when tested in the presence of 1- 5 mM EDTA. The properties of progesterone-receptor complex remained intact under the above conditions when analyzed for steroid-binding specificity and Scatchard analysis. However, the ATP-activated progesterone-receptor complex lost the ability to aggregate when tested on low-salt sucrose gradients. ATP was equally effective in activating the rat-uterine estradiol-receptor complex at 4 "C and influenced the transformation of 4-S receptor form into a 5-S form when analyzed on sucrose gradients containing 0.3 M KCI. The presence of ATP also increased the rate of activation of progesterone-receptor complex at 23 °C. These findings suggest a role for ATP in receptor function and offer a convenient method of studying the process of receptor activation at low temperature and mild assay conditions.