Selection of steels for industrial purposes usually means choosing a type of steel to make a part or a product. The steel that is chosen must meet all the designer requirements. A quantitative selection procedure has been used to analyze the large amount of data involved in this selection process so that a complete and systematic evaluation can be made. The designer is responsible for the selection of steel, and this selection requires the designer to find data and information on the mechanical properties required, and also learns ways to improve these properties through different heat treatment processes. When a large number of steels and a large number of specified mechanical properties are being evaluated for selection, the weighed properties method can require a large number of tedious and time-consuming calculations. In such cases a computer program could greatly facilitate the selection process. This thesis reports the selection of steels for gears, shafts, fasteners and springs where the steps involved in the weighted properties method which is written in the form of a simple computer program to select steels from a data bank. This program also includes the digital logic method to help in determining weighing factors. The steels are ranked according to standard designation; BS, AISI, and DIN. It has been found that alloyed steels hardened and tempered at 2050C are most suitable for gears, shafts, fasteners, and springs when higher mechanical properties required, and carbon and low alloyed steels when cost is the main consideration.

Depuis longtemps, l'éducation relative à l'environnement (ERE) est reconnue comme une stratégie de résolution des problèmes environnementaux. Mais au-delà de cette vision pragmatique, l'ERE doit aussi être envisagée comme un processus de développement des personnes et des groupes sociaux. Cette recherche vise à intégrer l'ERE dans le curriculum scolaire des étudiant(e)s du collégial. Nos buts sont de 1) contribuer à intégrer l'ERE comme dimension de la formation fondamentale des étudiant(e)s du collégial (volet intervention) et de 2) contribuer au développement théorique du domaine de l'ERE en milieu collégial (volet recherche). Pour ce faire, nous avons entrepris une recherche-action collaborative avec la direction et les enseignant(e)s du Cégep de Sorel-Tracy (2002-2004). Nous avons adopté une stratégie d'accompagnement des enseignant(e)s basée sur un partenariat université-collégial pour le développement de projets pédagogiques dans différents cours et programmes. Nos interventions ont été centrées sur la contamination de l'environnement par le mercure comme porte d'entrée pour une appréhension écosystémique de l'environnement. Notre recherche-action a comporté treize projets. Chaque projet a donné lieu à une recherche-action spécifique qui s'est inscrite dans notre démarche globale de recherche-action. Trois des treize projets développés ont fait l'objet d'une étude approfondie. La stratégie d'accompagnement que nous avons adoptée a présenté plusieurs avantages: stimuler l'innovation pédagogique chez les enseignant(e)s, faciliter l'accès à une expertise environnementale, créer un contexte d'intervention interdisciplinaire, motiver les étudiant(e)s à participer à des activités d'apprentissages portant sur l'environnement et la santé, etc. Notre projet s'est toutefois confronté à certaines limites dont l'appréhension d'une surcharge de travail pour les enseignant(e)s, des difficultés à intégrer les activités au plan de cours, un besoin de financement pour la réalisation de certaines activités, etc. Ce mémoire identifie également des enjeux reliés au contexte institutionnel et des enjeux pédagogiques pour l'intégration de l'ERE au curriculum du collégial. Finalement, cette recherche a permis d'identifier des avenues structurantes pour l'intégration de l'ERE au collégial dont 1) la reconnaissance de l'ERE par les instances gouvemementales, 2) la prise en compte de l'ERE lors de l'établissement des plans d'études, 3) l'intégration de l'ERE dans les plans cadre et 4) la prise en compte de l'ERE lors de la détermination des compétences à atteindre. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Éducation relative à l'environnement, Éducation relative à la santé environnementale, Mercure, Contaminants, Enseignement collégial.

The isotopic labelling of carbon in tree-rings varies as a function of growth season temperature and relative humidity. The isotopic labelling of oxygen in tree-rings varies as a function of source-water isotopic composition and humidity-dependent evaporative enrichment of leaf water during the growth season. The season of carbon-isotope labelling was identified statistically as late-spring to early-fall (April to October) for temperatures and relative humidity with a three-year weighted (50-30-20) carry-over due mainly to stored photosynthates. The season of oxygen-isotope labelling was identified statistically as a combination of a winter (pDecember to March) source-water signal (temperature-dependent precipitation isotope composition) with a late-spring to early-fall (April to October) humidity signal (evaporative enrichment of leaf water). A two-year carry-over was attributed to the residence time of soil water, but no notable photosynthate carry-over was identified. Carbon- and oxygen- (mechanistic) isotope response surface models were then compared and contrasted to regression-based bivariate and univariate models. It was found that in most cases the isotope response surface models were the best means of predicting isotopic labelling when environmental data are known. The carbon-isotope response surface was used to reconstruct 50-years (AD 1900-1954) of relative humidity data by introducing measured carbon isotope values and instrumental growth season temperature. During the analysis of the oxygen-isotope response surface we found an isotope-temperature relation that appears to reflect circulation-dependent damping. To verify this we introduced scaled values of the North Pacific index as a proxy for this suppression. The coupling of the isotope response surfaces generated a humidity reconstruction that is also thought to be driven by atmospheric circulation. Our reconstruction shows that the fluctuations in temperature range have not exceeded the natural variability in the instrumental record of the 20th century; however, the atmospheric moisture (humidity) reconstruction predicts a directional drying trend in the Peace-Athabasca Delta that appears to reflect increasingly zonal circulation in western Canada over this period.

Vehicular ad hoc networks (VANETs) are an extreme case of mobile ad hoc networks (MANETs). High speed and frequent network topology changes are the main characteristics of vehicular networks. These characteristics lead to special issues and challenges in the network design, especially at the medium access control (MAC) layer. Due to high speed of nodes and their frequent disconnections, it is difficult to design a MAC scheme in VANETs that satisfies the quality-of-service requirements in all networking scenarios. In this thesis, we provide a comprehensive evaluation of the mobility impact on the IEEE 802.11p MAC performance. The study evaluates basic performance metrics such as packet delivery ratio, throughput, and delay, as well as the impact of mobility factors. The study also presents a relation between the mobility factors and the respective medium access behavior. Moreover, a new unfairness problem according to node relative speed is identified for both broadcast and unicast scenarios. To achieve better performance, we propose two dynamic contention window mechanisms to alleviate network performance degradation due to high mobility. Extensive simulation results show the significant impact of mobility on the IEEE 802.11p MAC performance, an identification of a new unfairness problem in the vehicle-to-vehicle (V2V) communications, and the effectiveness of the proposed MAC schemes.

Bakgrund: Demens tillhör en av Sveriges största folksjukdomar och idag finns det cirka 150 000 personer som lider utav någon form av demenssjukdom, varav Alzheimers sjukdom är den vanligaste formen. Sjukdomen medför kognitiv nedsättning som successivt försämras under sjukdomsförloppet och ställer då allt högre krav på den sjukes familj. Syfte: Att beskriva upplevelsen av att vara anhörig till en person med Alzheimers sjukdom. Metod: Studien utfördes som en litteraturöversikt där 15 kvalitativa artiklar granskades och analyserades. Resultat: I resultatet framkom det att anhöriga upplevde en mängd olika känslor under sjukdomsprocessen, vilka kunde skilja sig beroende på vilken relation de hade till den sjuke. Känslorna var såväl positiva som negativa, med dominans av den negativa upplevelsen. Anhöriga upplevde bland annat ovisshet, sorg, förändrade roller, skuld och längtan efter det tidigare livet. Slutsats: När en person drabbas av Alzheimers sjukdom påverkas hela familjen och en stor livsförändring sker. Eftersom sjuksköterskan ofta är en naturlig samtalspartner är det viktigt att hon uppmärksammar den anhöriges upplevelser och genom förståelsen kan hon hjälpa anhöriga att uppleva situationen som meningsfull. Denna studie är menad att belysa anhörigas upplevelser och medvetandegöra att såväl den sjuke som dess anhörige är i behov av omtanke och stöd. / Background: Dementia is one of Sweden's most common diseases, and there are today currently about 150 000 people suffering of some form of dementia, of which Alzheimer's disease is the most common form. The disease results in cognitive impairment that gradually deteriorate during the course of the disease and be more demanding for their family. Aim: To describe the experience of being a relative of a person with Alzheimer's disease. Method: The study was performed as a literature study in which 15 qualitative articles were reviewed and analyzed. Result: The results revealed that relatives experienced a variety of emotions during the disease process, which could vary depending on the relationship they had for the ill familymember. The feelings were both positive and negative, with the dominance of the negative experience. Relatives perceived among other things uncertainty, grief, changing roles, guilt and longing for the past life. Conclusion: Since nurses often are a natural interlocutor, it´s important that they recognizes relative's experiences and through this understanding, they can support relatives to experience the situation as meaningful. This study is meant to highlight the family's experiences and awareness that both the ill family member and his or her relative is in need of kindness and support.

Gambling about money is a frequent phenomenon in our modern community’s. The gambling has for some people resulted in a compulsive gambling. These consequences affects not only the gambler but also have impact on his or hers relatives. The purpose of this study is to describe how a small selection off relatives to persons with a compulsive gambling experience the gambling consequences in there life. The empirical material consists of five interviews with five relatives to persons with a gambling dependence. Coping theory, theory of crises and a systemic perspective has been used to analyse the empirical material. The results that appear are that the relatives have all described early signs that they at the time could not interpret. They have felt that the gambler has been absent in mind. The discovery of the gambling describes as a chocking experience. They have created there own cooping strategies. The relatives show a great amount of strength and they have drawn positive experiences from a difficult reality like better relations and communication with the gambler, and can see that they have to take care of them selfs and not only care for the gambler. The study also indicates that family ties are hard to brake, especially between parents and there children.

Bakgrund: Antalet personer som insjuknar i demenssjukdom ökar världen över. Behovet efter utbildad personal och sjuksköterskans ansvar att kunna ge stöd och hjälp till demenssjukas anhöriga ökar därför också då en demenssjukdom påverkar hela familjen. Syfte: Syftet är att beskriva anhörigas upplevelser av att ha en nära familjemedlem med demenssjukdom. Metod: En systematisk litteraturstudie enligt Evans (2002) analysmetod har använts för att analysera 12 stycken kvalitativa artiklar. Nyckelfynd sammanfördes och bildade tre teman och sex stycken subteman. Resultat: Resultatet påvisar att anhöriga upplever blandade känslor av att en nära familjemedlem fått diagnosen demenssjukdom. Dessa upplevelser delades in i livet efter diagnosen, förluster och förändrad delaktighet till vården av den demenssjuke. Viljan att vårda sin familjemedlem, en förändrad vardag, förlust av kontroll, förlust av social samvaro och egen identitet, lämna över ansvaret och vara delaktig i vården på boendet var de subteman som uppkom. Slutsats: I arbetet klargjordes en rad upplevelser anhöriga hade utifrån att ha en nära familjemedlem med demenssjukdom. Dessa upplevelser bör sjuksköterskan ta del av inför det stöd och den handledning som erbjuds anhöriga. Mer forskning bör göras angående den hjälp som ges till anhöriga till demenssjuka. / Background: The number of people diagnosed with dementia is increasing worldwide. The need for trained personnel and the nurse's responsibility to provide support and assistance to families of people with dementia therefore increases since dementia affects the whole family. Aim: The purpose is to describe the relatives' experiences of having a close family member with dementia. Method: A systematic literature review of Evans (2002) analysis was used to analyze the 12 pieces of qualitative articles. Key findings were merged and formed three themes and six subthemes. Results: The results indicate that families are experiencing mixed feelings of a close family member diagnosed with dementia. These experiences were divided into life after diagnosis, losses and changes in participation to the care of people suffering from dementia. The desire to care for their family member, a change in living, loss of control, loss of social interaction and self-identity, hand over responsibility and be involved in the care of the accommodation was the subthemes that arose. Conclusion: This essay was made clear a number of relatives had experiences from having a close family member with dementia. These experiences should the nurse take note of for the support and guidance offered to relatives. More research should be done about the help given to families of people with dementia.

The isotopic labelling of carbon in tree-rings varies as a function of growth season temperature and relative humidity. The isotopic labelling of oxygen in tree-rings varies as a function of source-water isotopic composition and humidity-dependent evaporative enrichment of leaf water during the growth season. The season of carbon-isotope labelling was identified statistically as late-spring to early-fall (April to October) for temperatures and relative humidity with a three-year weighted (50-30-20) carry-over due mainly to stored photosynthates. The season of oxygen-isotope labelling was identified statistically as a combination of a winter (pDecember to March) source-water signal (temperature-dependent precipitation isotope composition) with a late-spring to early-fall (April to October) humidity signal (evaporative enrichment of leaf water). A two-year carry-over was attributed to the residence time of soil water, but no notable photosynthate carry-over was identified. Carbon- and oxygen- (mechanistic) isotope response surface models were then compared and contrasted to regression-based bivariate and univariate models. It was found that in most cases the isotope response surface models were the best means of predicting isotopic labelling when environmental data are known. The carbon-isotope response surface was used to reconstruct 50-years (AD 1900-1954) of relative humidity data by introducing measured carbon isotope values and instrumental growth season temperature. During the analysis of the oxygen-isotope response surface we found an isotope-temperature relation that appears to reflect circulation-dependent damping. To verify this we introduced scaled values of the North Pacific index as a proxy for this suppression. The coupling of the isotope response surfaces generated a humidity reconstruction that is also thought to be driven by atmospheric circulation. Our reconstruction shows that the fluctuations in temperature range have not exceeded the natural variability in the instrumental record of the 20th century; however, the atmospheric moisture (humidity) reconstruction predicts a directional drying trend in the Peace-Athabasca Delta that appears to reflect increasingly zonal circulation in western Canada over this period.

Vehicular ad hoc networks (VANETs) are an extreme case of mobile ad hoc networks (MANETs). High speed and frequent network topology changes are the main characteristics of vehicular networks. These characteristics lead to special issues and challenges in the network design, especially at the medium access control (MAC) layer. Due to high speed of nodes and their frequent disconnections, it is difficult to design a MAC scheme in VANETs that satisfies the quality-of-service requirements in all networking scenarios. In this thesis, we provide a comprehensive evaluation of the mobility impact on the IEEE 802.11p MAC performance. The study evaluates basic performance metrics such as packet delivery ratio, throughput, and delay, as well as the impact of mobility factors. The study also presents a relation between the mobility factors and the respective medium access behavior. Moreover, a new unfairness problem according to node relative speed is identified for both broadcast and unicast scenarios. To achieve better performance, we propose two dynamic contention window mechanisms to alleviate network performance degradation due to high mobility. Extensive simulation results show the significant impact of mobility on the IEEE 802.11p MAC performance, an identification of a new unfairness problem in the vehicle-to-vehicle (V2V) communications, and the effectiveness of the proposed MAC schemes.

The dynamics of a single underwater vehicle in an ideal irrotational fluid may be modeled by a Lagrangian system with configuration space the Euclidean group. If hydrodynamic coupling is ignored then two coupled vehicles may be modeled by the direct product of two single-vehicle systems. We consider this system in the case that the vehicles are coupled mechanically, with an ideal spherically symmetric joint, finding all of the relative equilibria. We demonstrate that there are relative equilibria in certain novel momentum-generator regimes identified by Patrick et.al. "<i>Stability of Poisson equilibria and Hamiltonian relative equilibria by energy methods</i>", Arch. Rational Mech. Anal., 174:301--344, 2004.