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Brown, Sarah Louise. "The social behaviour of neutered domestic cats (Felis catus)." Thesis, Boston Spa, U.K. : British Library Document Supply Centre, 1993. http://ethos.bl.uk/OrderDetails.do?did=1&uin=uk.bl.ethos.335664.
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Kerby, G. "The social organisation of farm cats (Felis catus)." Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382641.
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Stander, Philip. "Ecology and hunting behaviour of lions and leopards." Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337087.
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Maclean, Mairead Murdina. "The predatory behaviour of domestic house cats Felis catus L. and their impact on prey populations." Thesis, University of Exeter, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.439134.
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Ramos, Daniela. "Evaluation of medical, behavioural and physiological aspects of domestic cats (Felis catus) with inappropriate urination." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/10/10136/tde-26092012-163249/.
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Commonly reported refractoriness in feline cases of inappropriate urination, in spite of well established diagnosis schema and therapeutic regimens, emphasizes the need for reviewing traditional concepts and conducts. A case-control study with 18 "sprayer" and 23 "toileter" cats, and their respective controls from the same multi-cat households (3-9 cats), was performed to investigate the following aspects: disease, stress, personality, emotionality and social behaviour. A high prevalence of medical problems, including some alterations of the upper urinary tract, was equally found among "sprayers" and "toileters". Cystoscopy of female participant cats led to a probable diagnosis of interstitial cystitis in one "sprayer" and one "toileter". Unreliable values concerning plama bioamines restricted our understanding of the cats emotionality, but faecal glucocorticoid levels indicated that cats from spraying households ("sprayers" and their controls) were more aroused (probably more stressed) than cats from the toileting households. Cat owners were not consistent in their opinions with regard to personality but their more direct observations in respect to inter-cat relationships indicated that neither spraying nor toileting was associated with cats´ social behaviour or status. About recorded behaviours, no differences were seen between cases and "controls" from either of the groups. However, proportionally more time spent moving (as opposed to stationary) by cats from spraying houses might have reflected the higher arousal states of the former. Results reiterate the importance of medical check-ups in any case of inappropriate urination. Furthermore, they suggest spraying as a feline attempt to cope in highly stressful environments.Relatos comuns de refratariedade em casos de micção inapropriada em gatos, a despeito do esquema bem estabelecido de diagnóstico e regimes terapêuticos, enfatiza a necessidade de rever os conceitos tradicionais e condutas. Um estudo do tipo caso-controle com 18 gatos "sprayers" (manifestadores de marcação urinária) e 23 "toileters" (exibidores de micção fora da caixa sanitária), e seus respectivos controles oriundos das mesmas residências de mutiplos gatos (3-9 gatos), foi realizado para investigar os seguintes aspectos: doença, estresse, personalidade, emotividade, e comportamento social. A alta prevalência de problemas médicos, incluindo algumas alterações do trato urinário superior, foi igualmente encontrada entre os "sprayers" e "toileters". Cistoscopia realizada em fêmeas participantes da pesqusa levou ao provável diagnóstico de cistite intersticial em uma gata "sprayer" e uma "toileter". Valores não confiáveis de bioaminas plasmáticas restringiram nossa compreensão da emotividade dos gatos, mas os níveis de glicocorticóides fecais indicaram que os gatos das casas "spraying" ("sprayers" e seus controles), mostraram-se mais agitados (provavelmente mais estressados) do que os gatos das casas "toileting". Os proprietarios não se mostraram consistentes nas suas opiniões em relação à personalidade dos seus gatos, mas suas observações diretas a respeito das relações gato-gato indicaram que nem o "spraying" tampouco o "toileting" mostrou-se associado ao comportamento social e status do gato. Em relação aos comportamentos registrados em vídeo, não foram observadas diferenças entre "casos e "controles " em nenhum dos grupos. Entretanto, o maior tempo gasto movendo (proporcionalmente ao em estado estacionário) por gatos das casas "spraying" em comparação com aqueles das casas "toileting" pode ter refletido os estados mais elevados de excitação dos primeiros. Os resultados reiteram a importância dos "check-ups" médicos em qualquer caso de micção inapropriada. Além disso, sugere-se a marcação urinária como uma tentativa do felino para lidar em ambientes altamenteestressantes.
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Kalz, Beate. "Populationsbiologie, Raumnutzung und Verhalten verwildeter Hauskatzen und der Effekt von Maßnahmen zur Reproduktionskontrolle." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2001. http://dx.doi.org/10.18452/14587.
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In einem 45 ha großen Untersuchungsgebiet in der Innenstadt von Berlin wurden von Februar 1996 bis Juni 1999 alle dort vorkommenden verwilderten Katzen erfaßt. Wir untersuchten Alter- und Geschlechtsverteilung, Populationsdichte und -stabilität, Reproduktions- und Mortalitätsraten, Gesundheitsstatus, Territorialverhalten, Ver- wandtschaftsbeziehungen und den Einfluß der Kastration auf das individuelle Verhal- ten der Katzen und die Entwicklung der Population. Insgesamt wurden 75 Tiere in- nerhalb von 42 Monaten beobachtet. Im Untersuchungsgebiet waren gleichzeitig je- weils 25-32 Tiere ansässig, außerdem wurden durchschnittlich 10 Durchzügler pro Jahr registriert. Die ansässigen Katzen lebten in 2 genetisch differenzierten Teilpopu- lationen. Unkastrierte Kater hatten größere Streifgebiete (20-66 ha) als kastrierte Ka- ter, kastrierte und unkastrierte Katzen sowie Jungtiere (0,5-7,5 ha). Die Mortalität der ansässigen Katzen betrug 25 % pro Jahr. Vakante Streifgebiete wurden durch eige- ne Nachkommen aufgefüllt. Die Anzahl unkastrierter adulter Kater im Untersu- chungsgebiet blieb über die gesamte Zeit konstant, Kastration und Tod von Deckka- tern wurde durch Einwanderung fremder Kater kompensiert. Nach Kastration aller weiblicher Katzen einer Teilpopulation sank die Populationsdichte trotz signifikant höherer Zuwanderung fremder Tiere.In a 45 ha study area of Berlin city all cats were studied between February 1996 and June 1999. We investigated age and sex composition, population density and stabil- ity, rates of reproduction and mortality, health status, territorial behaviour, kinship re- lation, and the influence of neutering on individual behaviour and population devel- opment. Altogether we observed 75 cats within 42 months. 25 to 35 cats lived simul- taneously in the study area, additionally we found 10 transient animals per year on average. The resident cats lived in two genetically distinct subpopulations. Uncas- trated adult males had larger home ranges (20-66 ha) than castrated males, cas- trated and uncastrated females and subadult cats (0,5-7,5 ha). Mortality rate of resi- dent cats was 25 % per year. Vacancies were filled by own kittens. The number of uncastrated adult tomcats was constant throughout the study period, castration and death of stud males were compensated by immigration of unknown tomcats. After the castration of all females in one subpopulation population density declined, even though immigration of unknown cats increased significantly.
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Shreve, Kristyn R. "The Influence of Food Distribution and Relatedness on the Social Behaviours and Proximities of Free-Roaming Cats (Felis silvestris catus)." Miami University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=miami1414773468.
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Gomes, Mariana Martins Barbeito. "Clínica e cirurgia de felinos domésticos." Master's thesis, Universidade de Évora, 2021. http://hdl.handle.net/10174/29772.
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O presente relatório foi elaborado na sequência do estágio curricular do Mestrado Integrado de Medicina Veterinária da Universidade de Évora, realizado no Hospital do Gato, entre setembro de 2019 e fevereiro de 2020.
A primeira parte trata-se de uma análise casuística e breve descrição das atividades desenvolvidas e acompanhadas pela autora. Inclui revisões bibliográficas sucintas sobre uma afeção de cada área.
A segunda parte do relatório é uma monografia sobre «Abordagem cat-friendly» na qual é também apresentado um caso clínico.
A abordagem cat-friendly inclui o conhecimento do comportamento do gato, técnicas de contenção, realização de procedimentos e dicas para organização do CAMV (centro de atendimento médico veterinário) de modo a que o paciente felino se sinta o mais confortável e menos stressado possível; Abstract:
Feline medicine and surgery
The present report was written following the externship of the master’s degree in Veterinary Medicine of Universidade de Évora, performed at Hospital do Gato, between September of 2019 and February of 2020.
The first part includes the case analysis and a brief description of the activities developed and accompanied by the author. It contains succinct bibliographic reviews about a disease from each field.
The second part of the report is a monography about «Cat-friendly handling» including a clinical case.
The cat-friendly handling incorporates the knowledge about cat behavior, restraint techniques, procedure techniques and tips for organizing and preparing the clinic in order to provide a more comfortable and less stressful visit for the pacient.
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Hanson, Michaela. "Facial expressions and other behavioral responses to pleasant and unpleasant tastes in cats (Felis silvestris catus)." Thesis, Linköpings universitet, Biologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-119771.
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The behavior and facial expressions performed by cats have been reported to be visibly affected by the perceived taste quality of a food item. The goal of the present study was to assess how cats react to pleasant and unpleasant tastes. The facial and behavioral reactions of 13 cats to different concentrations of L-Proline and quinine monohydrochloride as well as mixtures with different concentrations of the two substances were assessed using a two-bottle preference test. The cats were videotaped during the tests and the frequency and duration of 50 different behaviors was analyzed in Noldus the Observer XT. The cats responded to tastes regarded as pleasant by having their eyes less than 50 % open for significantly longer periods of time compared to a water control. Tongue protrusions were also observed significantly more frequently when the cats sampled from a solution with a preferred taste compared to a water control. When encountering solutions of quinine monohydrochloride or mixtures containing quinine monohydrochloride the cats were observed to perform tongue protrusion gapes much more frequently compared to a water or L-Proline control. Even though the cats did not significantly differ in the number of times they licked at spouts containing the 50 mM L-Proline and 500 mM quinine monohydrochloride mixture compared to a 50 mM L-Proline, no masking effect could be confirmed as there was no increase in the acceptance of the mixture was observed. The present study suggests that the knowledge about behavioral responses to pleasant or unpleasant taste can be utilized in future studies on how cats perceive different tastes.
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Arney, Fiona. "Feral cats : a behavioural study in the South Australian Murray Mallee /." Title page, contents and abstract only, 1996. http://web4.library.adelaide.edu.au/theses/09SPS/09spsa748.pdf.
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D'sa, Candida Anne. "Behavioural aspects defining male dominance in feral farm cats (Felis silvestris catus)." Thesis, University of Southampton, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402396.
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Mendl, M. T. "Effects of litter size and sex of young on behavioural development in domestic cats." Thesis, University of Cambridge, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382658.
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Olofsson, Jakob. "Microstructure-based Mechanical Behaviour in Structural Analyses of Cast Components." Licentiate thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH. Forskningsmiljö Material och tillverkning – Gjutning, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-19127.
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In the process of developing cast iron and cast aluminium components, the co-operation between product development and production is important. On the engineering level, this co-operation is limited already in the product development phase e.g. by the lack of established methods to consider the mechanical behaviour of the completed component. This thesis aims to increase the possibilities for co-operation in the product realisation process between product development and production by enabling the use of predicted local mechanical behaviour in structural analyses of cast components. A literature review on existing simulation methods and a work on characterization of mechanical behaviour from microstructural features are performed to identify important knowledge gaps. A simulation strategy is formulated that is able to predict local mechanical behaviour throughout the entire component and incorporate the behaviour into a Finite Element Method (FEM) simulation of the structural behaviour of the component. In the simulation strategy, the component specific microstructure-based mechanical behaviour is predicted using a casting process simulation. A computer program is developed to create FEM material definitions that capture the local variations in mechanical behaviour throughout the component. The relevance of the simulation strategy is demonstrated for a ductile iron component. It is found that the local variations in mechanical behaviour result in a stress-strain distribution in the component that a homogeneous material description fails to express. Residual stresses affect the mechanical behaviour at low loads. At higher loads, however, the accuracy of the simulation is determined by the local variations in mechanical behaviour. Using a material reduction technique, the local mechanical behaviour can be incorporated without increasing the FEM simulation time.
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Li, Jing. "Alloying effect on boride formation behaviour in cast TiAl alloys." Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7170/.
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Boron addition has been used to refine the microstructures in TiAl castings, such as LPT blades, to improve ductility. However, boride precipitates with undesired morphologies could reduce ductility and even wipe out the entire benefit from grain refinement. Boride morphology in Ti45Al2Mn2Nb1B was found to be closely related to solidification conditions and proper processing windows have been established. In order to improve temperature capability of cast TiAl alloys to cater for the demand in new engines TiAl alloys have to be alloyed with more refractory elements, such as Nb and Ta, which will inevitably affect the boride morphologies. In this study variant alloys based on Ti45Al2Mn2Nb1B have been investigated with emphasis on the relationship between boride morphology, alloying element species and cooling conditions and distinctly different boride formation behaviour in different alloys was observed. In addition, curvy borides were found both on the fracture surface and within the microstructure in tensile test pieces, especially in Hf-containing test pieces, which indicate that curvy borides have the strongest effect in reducing ductility regardless of alloy composition.
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Cao, Jing. "The shear behaviour of the reinforced concrete four-pile caps." Thesis, University of Southampton, 2009. https://eprints.soton.ac.uk/73699/.
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There has been a consistent discrepancy between UK design standards BS5400 and BS8110 in the prediction of the shear capacity of 2-way spanning reinforced concrete pile caps from bending theory-based empirical design formulae. This causes designers difficulty to predict an accurate shear capacity of the pile cap. The inherently empirical character of the formulae is due to the fact that the formulae have been extrapolated from semi-empirical shear formulae for simply supported deep 1-way spanning beam structures, and been further empirically developed for 2-way spanning caps. Thus the essential cause of the discrepancy is that the formulae lack both physical explanation in terms of the cap’s shear behaviour, and sufficient basis as empirical formulae due to the shortage of experimental data. This research focuses on the revelation of the true shear capacity and failure mechanism of pile caps by consideration of a particular prototype form, namely a singly reinforced four-pile concrete cap under wall loading. It is aided by a series of laboratory experiments which are validated by an advanced non-linear numerical modelling for the reinforced concrete structure. The experience from the numerical modelling is taken further to carry out a parametric study expanding the sample size to a range covering more practical samples and covering different load patterns in order to enrich the limited data from the experiments. The results give a verdict that both BS5400 and BS8110 are conservative with the former one most conservative. The level of conservatism of the standards, the actual shear capacity and failure mechanism of the cap vary with key pile cap dimensions such as longitudinal and transverse pile spacing, shear enhancement factor, and the width of the cap over which the shear enhancement factor is applied. The shear behaviour of pile caps is also influenced by the load patterns. In this research, the strut-and-tie method has been proved to be a more efficient and precise method than the empirical formulae because it presents a physical explanation of the shear mechanism. Suggestions to improve the design method are given. A particular feature of this research is the application of a digital photogrammetry technique (PIV), normally applied in soil and fluid mechanics, to a solid mechanics situation. The tool has successfully detected the full-field displacement on the concrete surface and strains which are of high magnitude. The outputs have been compared with those from numerical modelling and they are in the same order of magnitude. The thesis describes the procedure of the application and an analysis of errors expected to occur in its application.
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Chiang, Mei-Fang. "Retirement Consumption Behavior: Evidence from HRS CAMS 2001-2009." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1338247837.
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MacLeod, Gavin 1972. "Influence of concrete strength on the behaviour of bridge pier caps." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=27239.
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Two full-scale reinforced concrete bridge pier caps were constructed and tested to investigate the influence of concrete strength on their behaviour. The amount of uniformly distributed reinforcement required for crack control at service load levels was also varied in order to investigate the suitability of current design approaches for these disturbed regions. In addition, strut-and-tie models, refined strut-and-tie models and non-linear finite element analyses are used to predict the complete behaviour of the test specimens.
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MacLeod, Gavin Drew. "Influence of concrete strength on the behaviour of bridge pier caps." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ29612.pdf.
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Hall, Sarah Louise. "Object play in the adult domestic cat : Felis silvestris catus." Thesis, University of Southampton, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263860.
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Li, Zili. "Long-term behaviour of cast-iron tunnel cross passage in London clay." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708631.
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Asbia, Salim Badre. "Short and long-term behaviour of dental cast restorations under compressive stresses." Thesis, University of Edinburgh, 2007. http://hdl.handle.net/1842/24720.
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This study examined indirectly the behaviour of zinc phosphate cement used to lute cast gold crowns. In order to standardise an in vitro method, cast nickel chrome dies were to represent natural molar teeth prepared to receive full gold crowns whilst the cast gold crowns were produced using standardised laboratory techniques. Initial work was undertaken to develop methods to control the distribution and film thickness of the cement beneath the crown. These were investigated together with the effects of preparations geometry and casting rigidity. Cement coverage had a strong influence on strain distribution. Increasing the cement film thickness led to an increase in compressive microstrain in the walls of the crowns, whilst both increasing the convergence angle and reducing the axial wall height of the preparation increased the axial compressive microstrain. However, the influence of axial wall height was greater than that of convergence angle. The influence of the casting rigidity showed an interesting finding. Heat treatment of the crown did not show differences in microstrain compared with the as cast control group, but increasing the occlusal surface thickness by a factor of three doubled the compressive axial microstrain recorded. The strain response curves for uncemented, partially cemented and fully cemented gold crowns to increasing static loads were recorded: these data were used to characterise the microstrain measurements from the later series of dynamic loading experiments. In the dynamic loading series, the crowns were partially cemented on their dies and axial loading was applies between 0-450N for approximately 300,000 cycles with a frequency of about 2Hz. In a series of four experiments, pairs of crowns were tested dry, immersed in water, in water and acid, and in acid alone (pH 2.74). The results were plotted as microstrain against a number of cycles. These showed that the hydration had a strong effect on the strain recorded on the axial surfaces of the cemented crowns compared with the dry samples. Whilst the presence of pure water decreased the microstrain, the presence of acid increased it. The pronounced effects were recorded in the presence of acidic media. Microscopic investigation showed damage to the luting cement was increased by the presence of moisture and further increased by the presence of acid. The conclusions drawn from this study were that the use of axially-placed strain gauges provided a method for monitoring the strain in the axial walls of cast gold crowns cemented with zinc phosphate cement. The strains were indicative of the condition of the bond between the die and crown provided by the cement. This method has further application in the non-destructive monitoring of the bond provided by luting cements between an indirect restoration and the underlying preparation.
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Zubritsky, Adam David. "Fatal Crashes Caused by Light Trucks Relative to Cars: A Test of the Offsetting Behavior Hypothesis." Master's thesis, University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3098.
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This thesis presents an econometric test of the offsetting behavior hypothesis concerning drivers of light trucks relative to cars. The main objective is to determine whether drivers of light trucks offset perceived safety benefits associated with larger vehicles by driving more aggressively than drivers of cars, subsequently causing more fatal crashes, holding all else constant. An empirical model using data on pedestrian fatalities across the United States over a five-year period is developed and analyzed in order to capture the desired results. Estimates provide substantial evidence in support of the offsetting behavior hypothesis. To strengthen the case for driver offsetting behavior beyond previous studies, the model is estimated again using pedalcyclist fatalities. The results also point to interesting conclusions regarding the effects of increased speed limits on the behavior of drivers.M.A.A.E.
Department of Economics
Business Administration
Applied Economics
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Jenkins, Jacqueline Marie. "Modeling the interaction between passenger cars and trucks." Texas A&M University, 2004. http://hdl.handle.net/1969.1/1296.
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The topic of this dissertation was the use of distributed computing to improve the modeling of the interaction between passenger cars and trucks. The two main focus areas were the development of a methodology to combine microscopic traffic simulation programs with driving simulator programs, and the application of a prototype distributed traffic simulation to study the impact of the length of an impeding vehicle on passing behavior.
The methodology was motivated by the need to provide an easier way to create calibrated traffic flows in driving simulations and to capture vehicle behavior within microscopic traffic simulations. The original design for the prototype was to establish a two-way, real time exchange of vehicle data, however problems were encountered that imposed limitations on its development and use.
The passing study was motivated by the possible changes in federal truck size and weight regulations and the current inconsistency between the passing sight distance criteria for the design of two lane highways and the marking of no-passing zones. Test drivers made passing maneuvers around impeding vehicles that differed in length and speed. The main effects of the impeding vehicle length were found to be significant for the time and distance in the left lane, and the start and end gap distances.
Passing equations were formulated based on the mechanics of the passing maneuver and included behavior variables for calibration. Through a sensitivity analysis, it was shown that increases in vehicle speeds, vehicle length, and gap distance increased the distance traveled in the left lane, while increases in the speed difference and speed gain decreased the distance traveled in the left lane. The passing equations were calibrated using the current AASHTO values and used to predict the impact of increased vehicle lengths on the time and distance in the left lane. The passing equations are valuable for evaluating passing sight distance criteria and observed passing behavior.
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Stella, Judith Lynn. "An Investigation of Environmental Factors that Affect the Behavior and Welfare of Domestic Cats (Felis sylvestris catus)." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1364486788.
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Berghuvud, Ansel. "Curving performance and nonlinear dynamic behaviour of freight cars with three-piece bogies /." Luleå, 2001. http://epubl.luth.se/1402-1544/2001/09/index.html.
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Brayshaw, Damien. "Use of numerical optimisation to determine on-limit handling behaviour of race cars." Thesis, Cranfield University, 2004. http://hdl.handle.net/1826/4506.
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The aim of this research is to use numerical optimisation to investigate the on-limit
behaviour of an open wheel downforce type race car using the best compromise of
modelling accuracy and computational effort.
The current state of lap simulation methods are identified, and the GG speed diagram
is described. The use of constrained optimisation, which is a form of optimal control,
is used to develop the methods described in this thesis. A seven degree of freedom
vehicle model validated by other researchers is used for method validation purposes,
and is extended, where possible, to make the modelling of vehicle components more
physically significant, without adversely affecting the computational time.
This research suggests a quasi steady state approach that produces a GG speed diagram
and circuit simulation tool that is capable of optimising vehicle parameters and
subsystems in addition to the prevailing control vector of steer and throttle response.
The use of numerical optimisation to optimise the rear differential hydraulic pressure
and the roll stiffness distribution to maximise vehicle performance is demonstrated.
The optimisation of the rear differential hydraulic pressure showed a very
small improvement in vehicle performance in combined high speed braking and cornering,
but highlighted the ability of the differential to affect the cornering behaviour
of the vehicle. The optimisation of the roll stiffness distribution research showed that
a significant improvement in the lateral acceleration capability of the vehicle could be
achieved at all vehicle speeds between 20 and 80m/s, especially in combined braking
and cornering.
In addition, a parameter sensitivity study around a realistic Formula One vehicle
setup was conducted, looking at the sensitivity of vehicle mass, yaw inertia, tyres,
centre of gravity location and engine torque to vehicle performance. An investigation
into the importance of the path finding calculation is also reported.
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Haidari, Hussein. "The Effect of Company Cars on the Travel Behaviour of Employees in Sweden." Thesis, KTH, Industriell ekonomi och organisation (Inst.), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-291451.
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Company cars are vehicles that are provided to employees owned by companies and organizations. These cars are provided for work-related travels and are also used for travels with private purposes. The issue is the way that company cars are affecting travel behaviour of employees and their family members, which in turn have implications on climate policies within Europe and even from economic aspects. Therefore, this paper will consider the impact that company cars have on the travel behaviour of employees with company car in Sweden. The thesis methodology takes advantage of both quantitative and qualitative method. Gathered quantitative data from Transport Analysis (TrafikAnalysen) was analyzed by regression analysis and qualitative data is analyzed by PESTEL-framework. The main outcomes of this paper are that company cars change individual’s travel behaviour in Sweden in terms of longer driven kilometers, which include even private travels. This depends on both economic aspects and the fact that "driving a company car" is a part of employee's behaviour now. Besides that, future environmental problems are also consequences of negative impacts of company cars on travel behaviour.Förmånsbilar är fordon som erbjuds från företag till anställda, som ägs av företag och organisationer. Dessa bilar tillhandahålls för arbetsrelaterade resor och används också för resor med privata ändamål. Problemet är det sättet som företagsbilar påverkar de anställdas och deras familjemedlemmars resbeteende, vilket i sin tur har konsekvenser för klimatpolitiken inom Europa och även från ekonomiska perspektiv. Därför, kommer denna uppsats att ta hänsyn tillhur företagsbilar påverkar resbeteendet av anställda som har förmånsbil i Sverige. Uppsatsen utnyttjar både kvantitativ och kvalitativ metod, där kvantitativa data analyseras med hjälp av regressionsanalys som är samlad av TrafikAnalysen och den kvalitativa delen analyseras genom PESTEL-framework. De viktigaste resultaten av denna uppsats är att förmånsbilar förändrar individens resbeteende i form av längre körda kilometer, vilket innebär även resor med privata syften. Detta beror på både ekonomiska aspekter och faktan att ”köra en förmånsbil” har blivit en vana hos de anställda. Dessutom, är framtida miljöproblem också konsekvenser av negativa påverkan som förmånsbilar har på individens resebeteende.
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Ward, Kristen. "Improving the Behavior of Special Concentrically Brace Frames with Cast Steel Inserts." Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/265376.
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A Cast Modular Ductile Bracing System (CMDB) has been developed as an alternative to special concentrically braced frames. The CMDB system introduces cast components at the ends and center of the brace in an attempt to produce a system with reliable strength, stiffness, and deformation capacity. A cruciform cross-section has been chosen for the cast component geometry, which is specially detailed to enhance energy dissipation and increase low cycle fatigue life thereby reducing the likelihood of fracture. In this dissertation, capacity design parameters are established that describe the axial strength and flexural strength of the cast components relative to the main hollow structural section member. These parameters are varied in 2D finite element models to understand the nature of the system and identify the best performing designs. The cruciform shape of the casting is varied to produce better performance and self-centering enhancements are introduced. 3D FE models of the CMDB system and a typical special concentrically braced frame, in combination with fracture indices, are used to compare the expected low cycle fatigue life of the two systems. The dynamic performance of the system is assessed through nonlinear finite element anaylses and conclusions are drawn. The performance of the system is proved experimentally.
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Butler, Luke C. "Behavior and Design of Cast-in-Place Anchors under Simulated Seismic Loading." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1382427376.
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Sjögren, Torsten. "Influences of the Graphite Phase on Elastic and Plastic Deformation Behaviour of Cast Irons." Doctoral thesis, Linköpings universitet, Konstruktionsmaterial, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8776.
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The amount and morphology of the graphite phase largely controls the resulting properties of cast iron. For instance, in flake graphite cast irons the mechanical properties are low while the thermal conductivity is high. This is in contrast with spheroidal graphite cast irons where the mechanical properties are high and the thermal conductivity is low. These differences are due to the different graphite morphologies and must be accounted for in the design work and material selection of cast iron components. In this work the influence of the graphite phase on the elastic and plastic deformation behaviour of cast irons has been studied. The material grades studied originate from castings for marine diesel engine piston rings with different chemical analyses. Two groups of pearlitic cast iron materials were studied; one with differences in graphite morphology and one with grey irons that differed in graphite content. For these different material grades the mechanical properties were correlated to microstructural parameters. In addition to standard uniaxial tensile tests, acoustic emission measurements were used for the study of deformation. When studying the modulus of elasticity of the cast iron it was found that the modulus of elasticity of the inherent graphite phase depends on the roundness of the graphite particles and is due to the strong anisotropy of the graphite phase. A linear correlation between nodularity and the modulus of elasticity of the graphite phase was derived. This correlation made it possible to account for the anisotropy of the graphite phase in the model used. By applying the linear function when modelling the effective modulus of elasticity, a high accuracy between experimental and theoretical values was achieved. Another factor affecting the elastic response when subjecting a cast iron component to tensile load was found to be the plastic deformation that actually occurs at very low strains for all of the studied cast iron grades. It was observed that the plastic deformation in the low strain elastic region, quantified by using acoustic emission measurements, increased linearly with decreasing modulus of elasticity. These measurements showed that the amount of plastic deformation in the elastic region was largely controlled by the graphite morphology. It was concluded that as the roundness of the graphite particles increases, the plastic deformation activity in the elastic region decreases. The plastic deformation activity continued linearly into the pronounced plastic region of the tensile tests. A decrease in roundness or increase in graphite fraction resulted in an increase of the amount of plastic deformation and the strain hardening exponent. A dependence between strength coefficient and graphite fraction was observed. Models for the flow curves for pearlitic cast irons were developed and shown to accurately reproduce the observed experimental curves. The surveys performed and conclusions from this thesis will be helpful in the design of new cast iron materials.
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Chen, Weijie. "Microstructure modification and mechanical behaviour of an investment cast near ã-TiAl intermetallic alloy." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0016/NQ57605.pdf.
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Sjögren, Torsten. "Influences of the graphite phase on elastic and plastic deformation behaviour of cast irons /." Jönköping : Linköping : Department of Mechanical Engineering, School of Engineering, Jönköping University ; Department of Management and Engineering, Linköping University, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8776.
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Chen, Weijie Carleton University Dissertation Engineering Mechanical and Aerospace. "Microstructure midification and mechanical behaviour of an investment cast near gamma-TiAl intermetallic alloy." Ottawa, 2000.
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Mohseni, Seyyed Mohammad. "Constitutive behaviour of aluminium alloy B206 : in the as-cast and artificially aged states." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/54534.
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The constitutive behaviour of the aluminum foundry alloy B206 has been investigated in both the as-cast and artificially aged states by combining compression, tension, hardness and calorimetry testing. Aluminum alloy B206 is a recently-developed high-strength foundry alloy that has strong potential for use in automotive, aerospace and energy applications. The results of the compression tests, performed on as-cast material and conducted on a Gleeble 3500 thermo-mechanical simulator over a broad range of temperature (50-530⁰C) and strain rates (10-³ ₋ 1s-¹), were used to develop an inclusive constitutive plastic flow behaviour model. A new unified constitutive model was introduced that combines a Ludwik model for flow stress description at low temperatures (50-300⁰C) with a Zener-Hollomon model at high temperatures (300-530⁰C) while accounting for the strain rate dependency of the transition between these two models. The results of the tensile tests, performed on the artificially aged material (ageing performed over a temperature range of 150-250⁰C and a heating duration range of 1-24h), were combined with the calorimetry experiments to develop a model that predicts yield strength. To fit the experimental data into a linear-fit type model that states the yield strength as a linear summation of the effective parameters, temperature and time dependency were introduced through a microstructural variable, precipitation fraction. The precipitation kinetics of B206 were described by an Avrami model that utilized the experimental data acquired from non-isothermal calorimetry followed by an analysis based on the Kissinger method. The remaining material constants in the linear-fit model were found by fitting the model against the tensile test results explaining the yield strength evolution up to the peak-aged state. The model predictions were then qualitatively compared to the results of the hardness measurements, restating the fast precipitation kinetics of B206 at the temperature range used during artificial aging and predicted by the Avrami model. Together, the developed models of B206 in the as-cast and artificially aged states can be used as part of a Through-Process model to optimize the performance of castings made from this alloy.Applied Science, Faculty of
Engineering, School of (Okanagan)
Graduate
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Geffen, Eli. "The behavioural ecology of the Blanford's fox, Vulpes cans, in Israel." Thesis, University of Oxford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257737.
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Riestra, Perna Martin Ignacio. "TAILORING PROPERTIES TO REPRESENT HPDC TENSILE AND FATIGUE BEHAVIOUR IN ALUMINIUM-SILICON CAST ALLOY PROTOTYPES." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH. Forskningsmiljö Material och tillverkning – Gjutning, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-27734.
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The work presented aims to find alternatives for the prototyping of components by sand and plaster mold manufacturing processes that deliver properties similar to high pressure die casting (HPDC). Sand and plaster test samples have been casted. The Al-7Si-0.35Mg alloy has been tested in as cast condition and in a heat treated condition; T5 for sand cast samples and T6 for those plaster cast. The Al-7Si-2Cu-0.35Mg alloy was also tested in as cast condition. Tensile, fatigue and hardness tests have been performed. Microstructural investigation comprising secondary dendrite arm spacing, defects, Fe-rich β-phases and Si size measurements has been performed on the different conditions. The results have been compared to available data for Al-9Si-3Cu-(Fe) alloy used in HPDC. The T5 heat treated sand cast condition has shown to have properties similar to HPDC. All other sand cast conditions, including the previously tested Al-9Si-3Cu-(Fe) alloy, have been shown to be reasonable alternatives.
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Al-Akaidi, Marwan Muhammad Hussain. "Prediction of the behaviour of light in light pipes for LCD instrument clusters." Thesis, Loughborough University, 1988. https://dspace.lboro.ac.uk/2134/26992.
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Liquid Crystal Displays are commonly used in automotive dashboards. The back lighting necessary for a Liquid Crystal Display (LCD) can be achieved by the use of a light source and a light box, light pipe, or a diffusing screen. The space constraints of an automobile dashboard often mean that the light pipe is the most suitable method of illumination. At present an optimum design for the light pipe is obtained by a "Cut and Try" approach in which several light pipes are usually moulded and tested before a satisfactory candidate is found. This thesis reports on experimental and theoretical work to improve the legibility and readability of 'on' and 'off' segments of liquid crystal displays and to automate the design of the light pipes using Computer-Aided Design.
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Xiao, Shuyuan, and Wei He. "A study of Chinese consumers’ attitudes toward Volvo cars." Thesis, Högskolan Väst, Avd för företagsekonomi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-3363.
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Zhejiang Geely holding Co. succeeded in purchasing Ford Motor Co’s Volvo unit, which was the hottest news in the world in 2010. Volvo needs the Chinese potential car market; Geely needs Volvo cars’ advanced technology. Such purchase arouses our interesting to conduct a research study on Chinese consumers’ attitude and intentions toward Volvo cars. Our aim with this study was to identify the most important attributes of Volvo for Chinese consumers; to analyse how Chinese consumers were influenced by other people’s opinions and to explore how Chinese culture factors such as face concern and group conformity influence consumers’ attitudes towards Volvo. In order to find the result, we used online self-completion questionnaires and choose customers from a life insurance company in Shanghai as our sample group. From the survey result we found that Volvo is the second most favourable brand that Chinese consumers want to own in the near future. The top three car attributes for the Chinese consumers when they were going to choose a car were quality, safety and fuel economy. But they had less knowledge or beliefs that Volvo car has an advantage with those attributes. Besides that, we find that Chinese consumers’ behavioural intention of buying Volvo is influenced by family, friends, perceived behaviour control and group conformity, but there is no relationship between face concern and buying behaviour.
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Bucher, Benoit Cyril Albert. "Underlying mechanisms and evolutionary roots of prosocial behaviors in non-human animals." Kyoto University, 2020. http://hdl.handle.net/2433/254500.
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Engesser, Valeska Katharina, and Inna Sawatzki. "Consumer Restistance to Innovations : The Case of Electric Passenger Cars on Gotland." Thesis, Uppsala universitet, Företagsekonomiska institutionen, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-303085.
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Background: The Swedish island Gotland provides suitable conditions for the successful implementation of electric cars. Despite these conditions and the availability of the product in the Gotlandic market, electric cars do not find acceptance among consumers on Gotland. This phenomenon of consumer resistance behavior represents a rather under-researched area in current literature. Since resistance behavior is one of the main reasons responsible for the high failure rate of innovative products such as electric cars, this justifies the relevance of this study. Purpose: The aim of this study is to explore the reasons for consumer resistance behavior towards electric cars on Gotland. By answering this question, the authors intend to contribute not only theoretically to the existing theory of this phenomenon but also to shed new light on the special case of Gotland regarding the non-adoption of electric cars. Methodology: In order to answer the research question, an exploratory case study approach was chosen. Quantitative data in form of a questionnaire as well as qualitative data including a group interview and six expert interviews were collected and analyzed. Key findings: The barriers preventing consumers on Gotland from adopting electric cars are rooted in four different areas. First, functional barriers occur due to the limited range of electric cars, the existing charging infrastructure, the purchase cost, as well as the technological development status of the car batteries. Second, institutional barriers arise since the local government does not provide sufficient support for the further implementation of electric cars and related issues. Third, a contextual barrier in terms of the local car industry was figured out. This contributes a lot the last identified barrier, the cognitive barrier, which concerns the consumers themselves since their lacking knowledge and awareness about issues related to electric cars on Gotland is one of the main reasons for the resistance towards this innovation. As long as these barriers exist, consumers tend to postpone the buying decision of this product to a future point in time.
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Dabayeh, Ashraf A. "The role of casting defects in the fatigue behavior of notched cast aluminum alloys." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0013/NQ32821.pdf.
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Bommaraju, Ramaprasad V. "Mold behavior, heat transfer and quality of billets cast with in-mold electromagnetic stirring." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28628.
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Mold behavior, mold-related quality and the columnar-to-equiaxed transition influenced by in-mold EMS were examined by performing trials at two steel companies, metallurgical examination of the billet samples and mathematical modelling. The thermal fields in the walls of billet molds (102 X 102mm and 127 X 178mm) and in the cooling water were monitored by a system of thermocouples as the EMS was switched on and off during the continuous casting of several heats. The effect of electro-magnetic stirring on mold heat extraction was found to be negligible. The mold temperatures and cooling water temperatures are strongly dependent on the mold/billet gap which is affected by dynamic distortion of the mold tube. In the case of the square mold, the time-dependent mold distortion resulted from boiling adjacent to the cold face due to low water velocity and poor water quality. In the rectangular mold, differential expansion of the wide and narrow faces of the mold led to periodic wall movement at the midface causing cycling in the mold and water temperature. Both effects completely dominated any potential influence of EMS on mold heat extraction.
Cooling water velocities measured in separate experiments and the mold temperature profiles were input to a two-dimensional heat-flow model to establish mold heat-flux profiles. A steep taper of 2.6 %/m in the upper regions of the mold increased heat extraction compared to previously published heat-flux data in 0.8 %/m tapered-molds. However, due to the periodic wall movement in the rectangular mold, the heat flux declines to lower values periodically. The calculated heat flux profiles were employed in a one-dimensional transient heat flow model to predict superheat removal from the liquid pool under a variety of assumed fluid flow conditions. The major heat flow effect of EMS was inferred to be one of increasing the convective heat flow at the solidification front leading to earlier superheat extraction from the liquid steel.
Solidification structures in billet samples collected during the trials were examined. The columnar-to-equiaxed transition in continuous casting takes place provided all the superheat is removed from the melt and there is a sufficient density of nuclei present in the pool. At superheats of <20° C in the tundish, high heat extraction in the mold and remelting of the mold generated nuclei facilitate the removal of the superheat well within the mold and the columnar-equiaxed transition is triggered after 10-15 mm of shell growth on both the inside and outside radius faces. At higher superheat in the tundish, the liquid pool leaves the mold with residual superheat which takes longer to remove because of the declining fluid flow. Even though all the superheat is removed lower in the machine, the columnar-equiaxed transition occurs only if dendrite debris generated in the vicinity of the mold has survived in their descent through the superheated liquid. The effect of carbon on the columnar-to-equiaxed transition appears to stem from its influence on facilitating dendrite arm remelting and the survival of the dendrite fragments till the pool reaches sub-liquidus temperature. EMS extracts more superheat by maintaining a steep temperature gradient in the thermal boundary ahead of the solidification front and achieves an earlier columnar-equiaxed transition.
Electro-magnetic stirring appears not to affect either the average depth or the variation of depth of oscillation marks across a given face. However, the electro-magnetically driven flow dominates the turbulance at the meniscus due to the input stream and stabilizes a meniscus shape with the result that the oscillation marks are also of a well-defined shape unlike the unstirred billets.
No influence of EMS was found on the formation of "hooks" or the fine equiaxed crystal zone near the surface. The influence of EMS on inclining the growing dendrites appears to not come into effect until about 1 mm of shell has formed. It appears that the existence of the momentum boundary layer where the velocity of the rotating steel falls to zero at the surface is the reason for the absence of the influence of EMS on the subsurface solidification.
Rhomboidity and off-corner crack formation were found to depend, as reported by previous researchers, on mold distortion and its dynamic nature. The absence of any effect of EMS on these defects is due to its lack of effect on mold heat transfer and thus mold distortion.Applied Science, Faculty of
Materials Engineering, Department of
Graduate
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Olsson, Magnus. "Behavior Trees for decision-making in Autonomous Driving." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-183060.
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This degree project investigates the suitability of using Behavior Trees (BT) as an architecture for the behavioral layer in autonomous driving. BTs originate from video game development but have received attention in robotics research the past couple of years. This project also includes implementation of a simulated traffic environment using the Unity3D engine, where the use of BTs is evaluated and compared to an implementation using finite-state machines (FSM). After the initial implementation, the simulation along with the control architectures were extended with additional behaviors in four steps. The different versions were evaluated using software maintainability metrics (Cyclomatic complexity and Maintainability index) in order to extrapolate and reason about more complex implementations as would be required in a real autonomous vehicle. It is concluded that as the AI requirements scale and grow more complex, the BTs likely become substantially more maintainable than FSMs and hence may prove a viable alternative for autonomous driving.
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Yi, Jianzhang. "Effect of microstructure and defects on the fatigue behaviour of cast A356-T6 aluminium-silicon alloy." Thesis, Imperial College London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405613.
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Byron, David W. "Aspects of the biology, behavior, bionomics, and control of immature stages of the cat flea Ctenocephalides felis felis (Bouche) (Siphonaptera: Pulicidae) in the domiciliary environment." Diss., Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/74762.
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The larval stage of the cat flea, Ctenocephalides felis felis (Bouche), was found to exhibit behaviors that were conducive to its security in carpet. Larvae exhibited positive geotactic, and negative phototactic behaviors. This resulted in the larvae spending greater than 80% of their time at the base of the carpet pile. Cat flea larvae also exhibited a positive hydrotaxis, and appeared to exhibit undirected movements when foraging. Larva were observed to respond to disturbances by coiling their body longitudinally.
Cat flea hatched and unhatched eggs, and larval exuviae were found to be dispersed in a contagious fashion within carpet. The spatial pattern of the immature stages and remains was influenced by the habits of the pet host within a given room. First-instar larvae do not move far, if at all, from the location of eclosion. The movement of the larval stage is influenced by biotic and abiotic factors in the environment. Areas of high pedestrian or pet traffic are not conducive to successful eclosion from the egg or for successful larval development.
Various methods of control exist for controlling an indoor infestation including both non-chemical and chemical tactics. A method for the physical control of immature stages in carpet is vacuuming. A beater-bar vacuum removes about 50% of the eggs but less than 30% of the larvae from a carpet. Chemical control tactics indoors are normally conducted using a compressed-air sprayer. Pressure within the application system is critical for creating spray patterns which can be overlapped to allow even insecticide coverage of the substrate. A compressed-air application system is not capable of delivering pesticides in a manner that will completely penetrate the carpet substrate to reach the base of the carpet. No significant differences in carpet penetration were observed over a range of 20 to 70 psi. Regardless of pressure, more than 93% of the solution applied to carpet was deposited in the upper third (6 mm) of the carpet.
Pet owners were surveyed about their knowledge and perceptions of household infestations of the cat flea, and also about financial expenditures and their willingness to pay for a flea-free environment. The importance and the pest status of flea infestations were determined to be based on physical, psychological, and economic impacts on homeowners. Respondents' perceptions of infestations on their pet were associated with infestation levels in the house. The respondents were willing to pay more for flea control in July, the onset of the flea season, than they were at the peak or decline of the season. They were also willing to pay more as their perception of the intensity of the problem on the pet or in the home increased. Household income was not shown to affect a respondent's actual financial expenditures or his willingness to pay for flea control on the pet or in the home.Ph. D.
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Damacena, Thais Borges 1988. "A singularidade dobra-dobra e o caos não determinístico." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/305969.
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Orientador: Marco Antonio TeixeiraDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matemática, Estatística e Computação Científica
Made available in DSpace on 2018-08-20T09:21:57Z (GMT). No. of bitstreams: 1 Damacena_ThaisBorges_M.pdf: 1821590 bytes, checksum: 6b7242d4adbe1ac4b9b0dcbe04dd70b7 (MD5) Previous issue date: 2012
Resumo: Um campo vetorial descontínuo 3D sobre uma superfície suave de codimensão um, pode ser genericamente tangente a ambos os lados da superfície em um ponto p. Os pontos onde esse fenômeno ocorre são chamados de singularidade dobra-dobra. Nesse trabalho, estudamos a dinâmica local de um sistema dinâmico suave por partes tri-dimensional em uma dobra-dobra. Vimos que a dinâmica local depende principalmente de um único parâmetro que controla uma bifurcação. Especificamente no caso onde as dobras são ambas invisíveis, a chamada singularidade Teixeira, encontramos que o sistema pode admitir um fluxo exibindo dinâmica caótica, mas não determinística
Abstract: A 3D discontinuous vector field on a smooth surface of codimension one, can be generically tangent to both sides of the surface at a point p. The points where this phenomenon occurs are called two-fold singularities. In this project, we study the local dynamics of a three-dimensional piecewise smooth dynamical systems at a two-fold. We have seen that the local dynamics depends mainly on a single parameter that controls a bifurcation. Specifically in the case where the folds are both invisibles, the so-called singularity Teixeira, we find that the system can admit a flow exhibiting chaotic but non-deterministic dynamics
Mestrado
Matematica
Mestre em Matemática
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Batmanghelich, Farhad. "Effect of mixed denitrifying and sulfate reducing bacterial biofilms on corrosion behavior of cast iron." University of Toledo / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1451311653.
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Kotadia, Hirenkumar R. "Solidification behaviour of Al-Sn-Cu immiscible alloys and Al-Si cast alloys processed under intensive shearing." Thesis, Brunel University, 2010. http://bura.brunel.ac.uk/handle/2438/4517.
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Alloy castings are usually solidified with a coarse columnar grain structure under normal casting conditions unless the mode of the solidification is carefully controlled. It is desirable for the grain structure to be fine and equiaxed to improve their mechanical performance as finished castings. It is possible to develop a fine and equiaxed grain structure either by increasing the number of nucleation sites or by grain multiplication. Immiscible alloys with a microstructure in which a soft phase is dispersed homogeneously in a hard matrix have significant potential applications in advanced bearing systems, especially for the automotive industry. Despite considerable efforts made worldwide, including extensive space experiments, no casting techniques so far can produce the desired immiscible microstructure of alloys. Experimental results on Al-Sn-Cu immiscible alloys have confirmed that intensive shearing using melt conditioning by an advanced shearing technology (MCAST) unit, is an effective way to achieve a fine and uniform dispersion of the soft phase without macro-demixing, and that such a dispersed microstructure can be further refined in alloys with precipitation of the primary Al phase prior to the demixing reaction. In addition, it was found that melt shearing at 200 rpm for 60 s will be adequate to produce a fine and uniform dispersion of the Sn phase, and that a higher shearing speed and prolonged shearing time can only achieve further minor refinement. A study of Al-Si hypoeutectic and hypereutectic alloys presents the effects of the processing temperature and intensive shearing on the microstructural and mechanical properties which have been investigated systematically. Attempts have been made to explain the solidification mechanism with intensive melt shearing. The sheared melt was cast into tensile test samples by high pressure die caster (HPDC) to examine the microstructures and mechanical properties. The experimental results reveal that significant grain refinement and uniformity of grains was achieved by the intensive shearing and also a considerable increase in mechanical properties with pouring temperature by changing intermetallic particles morphology, the position of defect band and reduced microscopic defects.
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Oliveira, Adriana Sicuto de. "Uso do espaço por animais confinados: o papel modulatório do enriquecimento ambiental." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/59/59134/tde-21052013-144138/.
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A garantia de bem-estar animal é essencial para assegurar resultados científicos confiáveis, e as técnicas de enriquecimento ambiental, utilizadas nessa busca, não podem ignorar as preferências e necessidades da espécie em questão, tais como o modo de utilização do espaço disponível. Nosso objetivo foi analisar como 35 gatos domésticos (12 machos e 23 fêmeas) utilizam seu espaço e as influências do enriquecimento ambiental nessa questão, visto que tal grupo contempla características de animais de companhia e também de biotério, sendo modelo em diversas pesquisas científicas. A utilização do espaço vertical foi quantificada a partir de filmagens das camas continuamente disponíveis em 4 níveis (0,60; 0,88; 1,16 e 1,46 m) e de refúgios (enriquecimento) em 3 diferentes alturas: 0, 0,5 e 1,0 m. Os resultados indicaram predileção pelas camas mais elevadas (1,46 m); entretanto, houve diferença significativa no tempo de utilização apenas para os refúgios a 0,5m, reforçando a importância de testar e confrontar as preferências dos animais em diferentes circunstâncias. Quanto ao uso do espaço horizontal, a disponibilização de refúgios alterou a distribuição dos animais na área de teste e aumentou comportamentos ativos e passivos. Testamos a escolha entre refúgios descobertos (100%) e com 50% de cobertura e também entre refúgios com aberturas laterais de 25% e 100%. Preferências não identificadas no primeiro teste (100% e 50% descobertas) tornaram-se aparentes quando as aberturas estavam nas laterais: os refúgios com 25% de abertura lateral foram utilizados por mais tempo. Tais resultados podem estar relacionados a ansiedade dos animais confinados, podendo esse teste ser uma potencial alternativa ao labirinto em cruz elevado para estudos de ansiedade com felinos. As diferenças observadas entre machos e fêmeas podem apontar influência diferenciada entre gêneros do confinamento no comportamento de animais castrados. Nossas conclusões ressaltam a necessidade do enriquecimento ambiental bem fundamentado na manutenção do bem-estar animal e sua interferência no uso do espaço.The guarantee of animal welfare is essential to ensure reliable scientific results, and the techniques of environmental enrichment, used in this quest, shall not ignore the needs and preferences of the species in question, such as how to use the available space. Our objective was to analyze how 35 cats (12 males and 23 females), use their space and the influences of environmental enrichment on this issue, since this group includes characteristics of pets and also of laboratory animals, being a model in several scientific studies. The use of vertical space was quantified through the filming of the continuously available beds in four levels (0.60, 0.88, 1.16 and 1.46 m) and the refuges (enrichment) in three different heights: 0, 0.5 and 1.0 m. Our results show that there is a preference for the higher beds (1.46 m); however, significant differences in time use was observed only for refuges in 0.5 m, reinforcing the importance of testing and comparing the preferences of animals in different circumstances. Regarding the use of horizontal space, the availability of refuges changed the distribution of animals in the test area and increased active and passive behaviors. We tested the choice between uncovered shelters (100%) and ones with 50% coverage and also shelters with lateral openings between 25% and 100%. Preferences which were not identified in the first test (100% and 50% uncovered) became apparent when the openings were on the sides: refuges with 25% side opening were used for a longer period. This finding may be related to the anxiety of confined animals, and this test may be a potential alternative to the elevated plus maze for studies of anxiety in cats. The differences observed between males and females may indicate the influence between genders of confinement on the behavior of castrated animals. Our findings highlight the need for well founded environmental enrichment in the maintenance of animal welfare and its interference with the use of space.
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Westhof, Liesel. "Corrective actions for indecisive behaviour of Foundation Phase learners during art activities." Diss., University of Pretoria, 2014. http://hdl.handle.net/2263/45873.
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The Foundation Phase in education provides the primary building blocks for young learners’ fundamental intellectual, social, physical and emotional basis of development. Holistic development is critical during the early years of the emergent learner’s life. Research has shown that it is imperative for young learners to make choices of their own accord, as room for independent decision making affords them the right to a “voice” and the opportunity to raise their own opinions which can contribute incrementally to their educational development.
Exercising personal choices demands self-confidence and resolution. Indecisiveness implies a lack of taking a stance at all, as passive learners who constantly vacillate cannot succeed in accomplishing the task at hand. Various internal and external factors contribute to young learners’ indecisive behaviour and this, in turn, leads to a lack of self-confidence and fear. One of the main external factors identified is the child-rearing style of caregivers and parents. When learners experience fear and a lack of self-confidence, their educational experiences are also negatively impacted and therefore holistic development cannot take place.
Research has indicated that visual art activities benefit young learners tremendously as they endow the learners with a more relaxed approach during activities due to the enjoyable character thereof. The focus in this study is consequently on rectifying young learners’ indecisiveness during visual art activities. All young learners dispose of the inherent potential to be creative and to express themselves through engaging with artwork, but when they lack self-confidence, they will be overcome with fear, hesitance and indecision. Social interaction as teaching strategy, as proposed by Lev Vygotsky (1896-1934) supports learners who have not yet reached their full potential, therefore group work can be introduced where a decisive learner can support indecisive peers to gain self-confidence, giving rise to a more enterprising and venturesome approach. (Van der Veer, 2007: 114–115; Newman & Holzman, 1993: 67).Dissertation (MEd)--University of Pretoria, 2014.
tm2015
Early Childhood Education
MEd
Unrestricted