952 resultados para spiral bevel gear
Resumo:
We study how conveyor drives in refrigerating rooms affect total energy costs. Studied conveyor drives are different types of gear motor drives. Energy efficiencies of the conveyor drives are determined by using direct torque measurement and energy costs of the conveyor drives are approximated from these results. From the measurement results and the approximated total costs it can be seen how the energy efficiency of a conveyor drive has a considerable influence on the total costs, especially, with large operating hours. An energy efficient conveyor drive can minimize the total energy costs by reducing the energy consumption of the conveyor motor while cooling costs in refrigerated rooms are also reduced.
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Coronary artery disease (CAD) is a chronic process that evolves over decades and may culminate in myocardial infarction (MI). While invasive coronary angiography (ICA) is still considered the gold standard of imaging CAD, non-invasive assessment of both the vascular anatomy and myocardial perfusion has become an intriguing alternative. In particular, computed tomography (CT) and positron emission tomography (PET) form an attractive combination for such studies. Increased radiation dose is, however, a concern. Our aim in the current thesis was to test novel CT and PET techniques alone and in hybrid setting in the detection and assessment of CAD in clinical patients. Along with diagnostic accuracy, methods for the reduction of the radiation dose was an important target. The study investigating the coronary arteries of patients with atrial fibrillation (AF) showed that CAD may be an important etiology of AF because a high prevalence of CAD was demonstrated within AF patients. In patients with suspected CAD, we demonstrated that a sequential, prospectively ECG-triggered CT technique was applicable to nearly 9/10 clinical patients and the radiation dose was over 60% lower than with spiral CT. To detect the functional significance of obstructive CAD, a novel software for perfusion quantification, CarimasTM, showed high reproducibility with 15O-labelled water in PET, supporting feasibility and good clinical accuracy. In a larger cohort of 107 patients with moderate 30-70% pre-test probability of CAD, hybrid PET/CT was shown to be a powerful diagnostic method in the assessment of CAD with diagnostic accuracy comparable to that of invasive angiography and fractional flow reserve (FFR) measurements. A hybrid study may be performed with a reasonable radiation dose in a vast majority of the cases, improving the performance of stand-alone PET and CT angiography, particularly when the absolute quantification of the perfusion is employed. These results can be applied into clinical practice and will be useful for daily clinical diagnosis of CAD.
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This study addresses the role of EFL education, its potential and shortcomings, and the challenges the future of EFL education will bring. It is argued that new societal demands and the limited time we have at our disposal in the classroom make it necessary to rethink goals and content and move away from the transmissionof limited sets of facts and information to helping students develop awareness and competences that can be applied in many different situations, also in a perspective of lifelong learning. The overall aim of the current study is to problematize and increase understanding of the implementation of cultural aspects in the language classroom by addressing the interrelated what, why and how of the cultural dimension within EFL education. This has been conducted by means of theoretical explorations into the area, alongside an attempt at promoting intercultural competence (IC) in a more systematic and insightful manner within my own educational praxis. The focus of the intercultural work in the classroom was on the promotion of awareness of difference and diversity, as well as respect for such difference through the ability to decenter from cultural norms and behavior that previously have been taken for granted. These are two elements that have been suggested as fundamental for other work with IC in the classroom and for the realization of important aspects of the underlying values of basic education. In the context of this study, IC comprises several interconnected components supportingeach other in a variety of ways, with the further aim being interaction with and respect for difference in general, not only concerning e.g. representatives ofcertain English-speaking communities. The methodology was informed by action research, with myself in the role of the teacher-researcher or the reflective practitioner. For the purpose of the project I was authorized to take on the EFL education for the three years of upper comprehensive school of one random class of students originally assigned to one of the language teachers of the selected Finland-Swedish school. Thus, the class of 17 students was not specifically chosen for the project, and the aims and contents chosen for the development project were placed within the framework of the ordinary curriculum. By exploring the students¿ insights concerning different English-speaking cultural groups, mainly through a set of questionnaires, it was possible to outline the work with the cultural dimension in the classroom for the following three years. Work progress was evaluated at specific stages, and the final project evaluations were conducted through individual student interviews in grade 9. The interviews were focused on possible development of students¿ insights concerning different aspects of the cultural dimension. In particular this concerned awareness of difference and diversity, including modification of stereotypes, as well as the ability to decenterin order to be better able to respect such difference. I also explored students¿ awareness and views of the activities and approaches used in class, as well asaffordances both inside and outside the EFL classroom in relation to these intended insights. A further focus area was the perceived relevance to students of different aspects of the cultural dimension. The frameworks and approaches adopted for the work in the classroom all have in common that they are based on a constructivist framework, where knowledge is constructed and reconstructed through interaction with one¿s social and cultural environment, including interaction with others. Reflective processes precede or are simultaneous with the learning of basic factual knowledge. This entails a view of learning as a progression from simple to more complex models rather than as a progression from facts to understanding and analysis. Here, the development of intercultural competence is seen asa cyclical process, or along a spiral curriculum, from simple to more complex levels through a combination of cognitive, affective and behavioral elements within a framework of experiential learning. This project has shown one possible wayforward concerning the development of intercultural competence within EFL education through a more systematic and comprehensive approach regarding linguistic and cultural aspects. The evaluation of the educational process explored in the study suggests the possibilities for work with the promotion of awareness of difference and diversity concerning some specific context that, based on students¿ prior knowledge and preconceptions, would benefit from further work. In this case, the specific context primarily concerned different aspects of both cultural and linguistic conditions in the UK. It is also suggested that many students developed the ability to decenter, described in the study as integral to being able to respect otherness. What still remains to be explored are more individualized approaches considering students¿ different levels of departure. Further work alsoneeds to be put into how to apply insights gained in these specific situations to more general contexts. It is also necessary to explore the use of the suggested approaches in a wider range of different contexts.
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This study is made in the context of basic research within the field ofcaring science. The aim is to make a theoretical and ontological investigation of what the space is in the world of caring. The basic proposition is that the space, as a fundamental dimension, has an impact on how the appreciation of one's mental health and suffering is shaped, and vice versa. The overall purpose is to develop a theoretical model of space from the caring science point of view andalso to offer an ideal concept of space to caring science. Guided by a theoretical horizon (Eriksson 1993, Eriksson 1995, Eriksson 2001) and methodological approach grounded in Gadamer's philosophic and existential hermeneutics a three-stage analysis and interpretation is conducted. The hermeneutic spiral of this investigation starts through a procedure in accordance with Eriksson's model (1997) of concept definition. The goal is to clarify the etymology of the concept as well as semantic differences between synonymous concepts, i.e. to identify the different extents of the concept of `space` (`rum`) in order to bring these closer for an exploration. The second phase is to analyse and interpret a sample of narratives in order to explicate the ontological nature and meaning of the space. The material used here is literary texts. The goal is to clarify the characteristics of the very inside of the space when it is shaped in relation to the human being in encountering suffering. In the third phase an interview study is taken place. The focus of the study is directed towards the phenomenon of space as it is known by a patient in a landscape of psychiatric care, i.e. what the space is in a contextual meaning. Then, a gradual hermeneutic understanding of the space is attempted by using theories from the field of caring science as well as additional theories from other disciplines. Metaphors are used as they are vivid and expressive tools for generating meaning. Different metaphoric space formations depict here a variety of purports that, although not quite the same, share extensive elements. Six metaphorically summarized entities of meaning emerged. The comprehensive form of space is pointed out as the Mobile-Immobile Room. Furthermore, the Standby, the Asylum, the Wall and the Place. In the further dialogue with the texts the understanding has deepened ontologically. The theoretical model ofthe space sums up the vertical, horizontal and the inward extent of deepness inthe movement of mental health. Three entities of ontological meaning have emerged as three significant rooms: the Common Land emerges as the ideal concept of mutual creation in the freedom of doing, being and becoming health. On the interpersonal level it means freedom, which includes sovereignty, choice and dignity of the human being. The Ice World signifies, ultimately, the space as a kind of frozenness of despair which "wallpapers" the person's entire being in the world in the drama of suffering. The Spiritual Home is shaped when the human being has acquired the very core of his/her inner and outer placeness as a kind of "at-homeness" and rootedness. Time is a central element and the inward extent of deepness of this trialectic space. Each of the metaphors is then the human being's unique, although even paradoxical, way of conceiving reality, and mastering spiritual suffering. They condense characteristic structures and patterns of dynamic scenery, which take place within the movement of health. The space encloses a contradictory spatiality constituted through the dynamic field of meaningfulness and meaninglessness. Anyway, it is not through a purging of these contradictions but through bringing them together in a drama of suffering that the space is shaped as ontologically good and meaningful in the world of caring.
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Studiens overordnede hensikt er å bestemme begrepet ensomhet i et vårdvitenskapelig perspektiv. Avhandlingen er en monografisk eksplorativ hermeneutisk studie og oppbygget i fire større helheter, der første hoveddel starter med en inntreden i den hermeneutiske spiral, og hvor paradigme, ontologiske, epistemologiske og metodologiske overveielser angir studiens videre retning. Andre hoveddel anses som studiens teoretiske substans og belyser ensomhetens `Hva´ gjennom ulike teoretiske perspektiv og begrepsanalyse av ensom. I belysningen framkommer ensomhet både som lidelse og som meningsfullt for eksistensen. Første hoveddel avsluttes med en bestemmelse av ensomhet som substanskunnskap innenfor vårdvitenskapens helse-og lidelsesforhold som utgjør ulike nivåer av gjørende, værende og vardende. Tredje hoveddel er en empiriskstudie med deltagende observasjon, forskersamtaler og kvalitative intervjuer i samtaleform. Informantene var åtte aleneboende personer med alvorlig psykisk lidelse i en storby og foregikk over ca. ett år. I tolkningsprosessen søkes en gradvis fordypende forståelse av den enkelte informants ensomhet i relasjon til vårdvitenskapens livs-, sykdoms- og vårdlidelse. Tolkningsrammen er i det vesentligefra første teoridel, samtidig som nye tolkningsteoretikere innlemmes som opplysende "lamper". Forståelsens tolkningsresultater framkommer gjennom en sammenfattende diskusjon, der livsberettelsens felles skjebne synliggjør savn som ideografisk invarians. Fjerde hoveddel er en vårdvitenskapelig filosofisk belysning av forholdet ensomhet og savn, hvor Levinas' fundamentaletikk utgjør tolkningsrammen. Studien avsluttes med en horisontsammensmeltning av forholdet ensomhet og savngjennom fellesskap og oppfyllelse i tid og rom. Horisontsammensmeltningen viserat ensomhet og savn i sin dybdestruktur forholder seg til hverandre i en dialektikk til motsetningene: fellesskap og oppfyllelse. Det nedfelles fem teser som ansatser til vårdvitenskapelig teori. Resultatene får implikasjoner for så vel pedagogikk som vårdpraksis.
Resumo:
Appearance of the vibration is the very important problem in long tool turning and milling. Current solutions of minimizing vibrations provided by different tool suppliers are very expensive. This Master’s Thesis is presenting the new type of vibration free machining tools produced by Konepaja ASTEX Gear Oy that have cheaper production costs compare to competitors’ products. Vibration problems in machining and their today’s solutions are analyzed in this work. The new vibration damping invention is presented and described. Moreover, the production, laboratory experimental modal analysis and practical testing of the new vibration free prototypes are observed and analyzed on the pages of this Thesis. Based on the testing results the new invention is acknowledged to be successful and approved for further studies and developments.
Resumo:
Konecranes Corporation manufactures huge steel structures in 16 factories worldwide, in which the environment and quality varies. The company has a desire to achieve the same weld quality in each factory, regardless of the manufacturing place. The main subject of this master’s thesis was to develop the present box girder crane welding process, submerged arc welding and especially the fillet welding. Throughput time and manufacturing costs can be decreased by welding the full penetration fillet weld without a bevel, changing present groove types for more appropriate ones and by achieving the desired weld quality on the first time. Welding experiments of longitudinal fillet welding were made according to the present challenges, which the manufacturing process is facing. In longitudinal fillet welding tests the main focus was to achieve full penetration fillet weld for 6, 8 and 10 millimeters thick web plates with single and twin wire submerged arc welding. Full penetration was achieved with all the material thicknesses, both with single and twin wire submerged arc welding processes. The main problem concerning the weld was undercutting and shape of the weld bead. The question about insufficiency of presently used power sources with twin wire was risen up during testing, due to the thicknesses that require high welding current. Bigger power source is required when box girders are welded nonstop, if twin wire is used. For single wire process the penetration was achieved with significantly less amperage than with twin wire.
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Tässä väitöskirjassa tarkastellaan suurnopeustekniikan eri sovelluksissa ilmeneviä roottoreihin liittyviä rakenteellisia vaatimuksia ja haasteita. Tässä yhteydessä suurnopeustekniikalla tarkoitetaan järjestelyä, jossa sähkökone (moottori, generaattori) ja toimilaite (turbiini, kompressori, puhallin) on kytketty ilman vaihdetta suoraan mekaanisesti yhteen ja jossa yhteisen roottorin pyörimisnopeus on selvästi suurempi kuin 50/60 hertsin verkosta syötetyn kaksinapaisen vaihtovirtasähkökoneen tahtinopeus. Tyypillistä suurnopeuskoneen roottorille on suuri tehotiheys ja suuri mekaaninen kuormitus. Siksi esimerkiksi sähkökoneen jäähdytys on entistä haasteellisempaa kasvavien rautahäviöiden ja pienempien lämmönsiirtopinta-alojen vuoksi. Tämän työn tavoitteet voidaan jakaa kolmeen osaan: Yhdistetyn sähkö- ja turbokoneen roottorin mekaanisen rakenteen tarkastelu, jonka tavoitteena on pienentää lämmönkehitystä ja tehostaa kriittisten kohtien jäähdytystä. Tähän liittyy sähkömagneettisten häviöiden keskittäminen jäähdytyksen kannalta edullisiin kohtiin Yhdistetyn sähkö- ja turbokoneen roottorin mekaanisen rakenteen tarkastelu kriittisten ominaistaajuuksien kannalta Yhdistetyn sähkö- ja turbokoneen roottorin mekaanisen rakenteen analysointi lujuustekniseltä kannalta. Tähän liittyvät mm. erilaiset ahdistussovitteet ja niiden säilyminen korkeilla pyörimisnopeuksilla sekä niiden roottoria jäykistävä vaikutus ja lämmön johtuminen kyseisissä liitospinnoissa. Tämän työn tieteellinen uutuusarvo on nimenomaan yhdistetyn sähkö- ja turbokoneen roottorin rakenteen analysointi ottamalla samanaikaisesti huomioon kaikki edellä mainitut näkökohdat: jäähtyminen erityisen kuumissa kohdissa, sähköisten häviöiden alentaminen ja niiden jakautuman huomioon ottaminen, roottorin jäykkyyden maksimointi, lujuusrasitusten hallinta ja rakenteen mekaaninen stabiliteetti sekä lämpöteknisten ylimenovastusten tarkastelu.
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’Bry sig om’ förekommer flitigt i sammanhang där människor vårdar och tar hand om varandra såväl i det vardagliga naturliga vårdandet som i det professionella vårdandet. ’Bry sig om’ är ett språkligt uttryck i människors vardagsspråk som hör samman med ’små vardagliga saker’ som är av betydelse. ’Bry sig om’ har även tydlig förbindelse med vårda och ansa i Erikssons caritativa vårdteori men har inte tidigare varit föremål för klinisk vårdvetenskaplig forskning vilket är bakgrunden till denna studie. Inom Erikssons caritativa vårdteori utgörs grundordningen av kärnbegreppen caritas, enheten människa, hälsa, lidande och vårdande. I den här avhandlingen är syftet att vidga förståelsen för kärnbegreppet vårdandet genom att utforska innebörden i praxisbegreppet ’bry sig om’. Studien har en hermeneutisk ansats och är en sammanläggningsavhandling med fyra delstudier i form av begreppsanalys och tre empiriska studier. Materialet i begreppsutredningen är etymologisk ordbok och svenska ordböcker. I de empiriska delstudierna består materialet av självbiografisk text skrivet av en patient och händelser som patienter och vårdare varit med om vilket förstås som betydelsefullt material för klinisk vårdvetenskaplig forskning. Den nya förståelsen gestaltas i ett tankemönster där ’bry sig om’ framträder som en inre etisk hållning där människan som är på plats kan finnas till och därmed betyda något för en annan människa. Att betyda något för en annan människa är uttryck för det naturliga omsorgsfulla vårdandet där patienten förnimmer en kärleksfull hållning i vårdarens varsamma kärleksfulla händer och varma röst. ’Bry sig om’, har sin grundval i det naturliga omsorgsfulla vårdandet som konstituerar människan som människa. Det som framkommit i avhandlingen är möjligheten att undersöka praxisbegrepp inom vårdvetenskapen där ’bry sig om’ bidragit till att synliggöra vårdandet och därmed innebörden och meningen i ansandet, lekandet och lärandet på ett nytt och annorlunda sätt ur ett kliniskt vårdvetenskapligt perspektiv.
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Työn lähtökohtana on ICT-alan yrityksen AinaCom Oy:n toimintaympäristön muutos, ja siihen toteutettava vaatimusmäärittely. Vaatimusmäärittelyn toteutukseen otetaan tueksi tietojohtaminen, jonka avulla saadaan syvyyttä perinteiseen vaatimusmäärittelyyn. Sekä vaatimusmäärittelyä että toimintaympäristön muutosta, tarkemmin ERP (Enteprise Resource Planning) toiminnanohjausjärjestelmä-projektia, tehostetaan tietojohtamisen keinoin. Työn tavoitteena on selvittää miten tietojohtaminen voidaan ottaa vaatimusmäärittelyn tueksi toimintaympäristön muutoksessa. Sekä kirjallisuuskatsauksen että AinaCom Oy:n vaatimusmäärittelyprojektin perusteella voidaan todeta, että tietojohtamisen ja tiedon spiraalin (SECI-malli) avulla voidaan edesauttaa tiedon hallitsemista mittavissa ohjelmistoprojekteissa, kuten ERP-projektissa, sekä vaatimusmäärittelyssä. Näin tietojohtamisen avulla voidaan saavuttaa hallittavampia aikatauluja, kohtuullisempia kustannuksia, sekä menestyksekkäämpiä projekteja.
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This study aimed to determine both the lethal and sublethal concentrations of Cypermethrin in young Silver Catfish (Brazilian "Jundiá", Rhamdia quelen) on aquatic environment during 96 hours, as well as to determine the Cypermethrin and Deltamethrin sublethal concentrations during the initial embryonic development period of Rhamdia quelen, and to verify their respective rates of fertilization, hatching and survival. Pyrethroid nowadays is a widely used insecticide, which presents a high toxicity to fish. In order to determine lethal and sublethal concentrations, 120 silver catfish were used; each one had an average weight of 59.58±4.50g and an average size of 20.33±2.34cm. Concentrations used were 0, 1.0, 1.5, 2.0, 2.5, 3.0, 5.0, 10.0, 15.0 and 20.0mg of Cypermethrin per liter of water (mg/L). Fish were exposed to the product in 30-liter fish tanks. In each fish tank there were four fishes and the product was applied three times, i.e., a total of twelve fish were exposed to the product at each application, and a total of 120 fish during the entire experiment (n=120). In order to determine the Cypermethrin and Deltamethrin sublethal concentrations during the initial embryonic development, ovulation induction was performed on female fishes using hormones, and then and egg collection was performed. The eggs were then hydrated and fertilized in Cypermethrin and Deltamethrin in different concentrations: 0.001, 0.01, 0.1, 1.0 and 10.0mg/L of Cypermethrin and 0.001, 0.01, 0.1, 0.5 and 1.0mg/L of Deltamethrin, in addition to the control group (0mg/L). After fertilization, the eggs were kept in containers with the respective pesticides of Cypermethrin and Deltamethrin until hatching, when hatching rate was verified. Then the alevins, from the hatching, were kept on their respective concentrations of Cypermethrin and Deltamethrin so that the survival rate could be analyzed regarding the tested insecticides, during both 12-hour and 24-hour periods. Concerning the sublethal and lethal concentrations, Silver Catfish was sensitive to the tested concentrations of Cypermethrin, showing symptoms of poisoning, such as loss of balance, swimming alteration, dyspnea (they kept their mouths and opercula open), upright swimming and sudden spiral swimming movements. The intensity of such symptoms varied in proportion to the concentration used. The concentrations above 3.0mg/L were considered lethal to the species, since every animal exposed to concentrations between 3.0 and 20.0mg/L had died, while concentrations between 1.0 and 2.5mg/L were considered sublethal. Lethal concentration of Cypermethrin to Silver catfish, in 96 hours, was 1.71 milligram per liter of water. Concerning the sublethal concentration of Cypermethrin and Deltamethrin during the initial embryonic development, the results show that both pyrethroids had significantly decreased the analyzed parameters when comparing them with the control group. It was concluded that, even with the fish being more resistant to pyrethroids in comparison with other species, both the young animals and the ones in stage of embryonic development were susceptible to the effects of these pesticides.
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This study is a survey of benefits and drawbacks of embedding a variable gearbox instead of a single reduction gear in electric vehicle powertrain from efficiency point of view. Losses due to a pair of spur gears meshing with involute teeth are modeled on the base of Coulomb’s law and fluid mechanics. The model for a variable gearbox is fulfilled and further employed in a complete vehicle simulation. Simulation model run for a single reduction gear then the results are taken as benchmark for other types of commonly used transmissions. Comparing power consumption, which is obtained from simulation model, shows that the extra load imposed by variable transmission components will shade the benefits of efficient operation of electric motor. The other accomplishment of this study is a combination of modified formulas that led to a new methodology for power loss prediction in gear meshing which is compatible with modern design and manufacturing technology.
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The rapid economic growth in China has resulted in environmental challenges ranging from air pollution to water-related issues. Thus supporting clean technology, or cleantech, that encompasses industries that focus on alternative energy, pollution and recycling, power supplies and conservation has become one of the focal points in the Chinese economic policy for the next decade. Simultaneously, the Finnish government has initiated programs to support the internationalisation of domestic cleantech companies in an attempt to spiral the industry into one of the pillars of Finnish economic growth. This study concentrates on the conjunction of these two themes and studies the challenges faced by Finnish cleantech SMEs in the Chinese market. Consequently, the study answers the following sub questions: 1. What human and financial resource-based challenges do Finnish cleantech SMEs face in the Chinese market and what are their solutions? 2. What knowledge-based challenges do Finnish cleantech SMEs face in the Chinese market and how can these difficulties be resolved? 3. What network-based challenges do Finnish cleantech SMEs face in the Chinese market, how do they relate to the resource- and knowledge-based challenges, and how can these difficulties be resolved? This qualitative study is conducted by analysing four semi structured interviews collected from four Finnish SMEs that operate in China. The findings of the study indicate that in human resources the most important challenges are related to the hiring and retaining of employees. In contrast to extant academic literature results distinguish salary and social status as the main solutions to this challenge. Regarding financial resources it is discovered that cleantech companies enjoy a benign business environment in China and benefit from the Chinese government’s support for cleantech industry. Challenges related to knowledge resources can be grouped into categories with the most interesting knowledge flows being the stream of local market knowledge into to the foreign parent company and the outward flow of manufacturing and business practice information into the target venture. The challenge related to the first flow is gathering relevant information and the main solutions are clustering at the foreign location and hiring knowledge prior to internationalisation. Regarding the second flow the main challenge is related to intellectual property rights and the most interesting solution is the purposeful transformation of explicit knowledge into tacit knowledge. Finally, it is discovered that networks, called guanxi in China, greatly affect the business processes. Within the guanxi system there is the concept of face which was found to affect employee propensity to stay as well as, as a novel academic result, employees’ knowledge sharing intention.