4,254 research outputs found
International students experiencing super-mobility in Scotland, Malta, Sweden, and Portugal through the TourDC programme
This dissertation aims to explore and complete the existent literature regarding student mobility in Europe. Furthermore, it intends to provide an understanding of the motivations, perceptions, and pre-conceptions of Erasmus Mundus students, also known as `super mobile` students. This dissertation will focus on students undertaking the EMJMD in Tourism and Culture (TourDC), taking place in Scotland, Malta, Sweden, and Portugal. The research has been made through semi-structured interviews conducted amongst a sample of fourteen TourDC students or alumni X. It thus attempts to further our understanding about how students live their academic and cultural experiences during the Erasmus Mundus TourDC programme. The obligation of the findings are firstly understanding the motivations of Erasmus Mundus TourDC students; secondly, the study of the cultural acclimatisation to the countries visited during the programme; and finally the identification of potential patterns for Erasmus Mundus students in terms of family, education, and cultural backgrounds. This paper demonstrates that almost all the students had a positive experience throughout their mobilities and therefore now feel prepared to pursue their chosen career path after graduation
Hybridization effect on mechanical properties of composite laminates
Composite materials are increasingly being used in the aeronautical industry. Although
carbon fibers are the strongest and most used in the aeronautical sector, these fibers collapse quite suddenly due to their fragile nature leading to catastrophic damage. In order to
minimize this effect, an alternative technique is used, which consists of combining these
fibers with another less fragile type, such as Kevlar fiber, in order to obtain a material
with a more ductile behavior. As the viscoelastic behavior is not much discussed in the
available open literature, this work intends to study this mechanical property in several
hybrid composites involving carbon, kevlar and glass fibers. For a better understanding
of this phenomenon, the static behavior and tenacity of these materials were also studied.
For this purpose, the effect of hybridization on flexural properties, interlaminar shear
strength, creep and stress relaxation was studied in eighteen hybrid combinations combined with an epoxy matrix. It was observed that hybridization can create a more tenacious and balanced composite. The stacking sequence has a significant influence on the
mechanical properties of laminates. As such, for all mechanical tests, carbon fibers are
better in compression if hybridized with kevlar and better in tension if hybridized with
glass. Glass fibers have always performed better under compression and kevlar fibers always perform better under tension, regardless of which other fiber they are hybridized to.
With these positions in the laminate, the composites achieve greater tension and stiffness,
but less deformation, greater interlaminar shear strength, less creep and less stress relaxation. As for the number of fiber layers, in the bending properties, a lower percentage of
kevlar in the laminate results in higher bending stress and interlaminar shear strength.
However, for the viscoelastic behavior of hybrid composites, the number of layers has no
direct influence on the creep and stress relaxation values, since molecular rearrangements
occur. In addition, a study of the bending properties for different strain rates in carbon
fiber composites and fiberglass composites was carried out. In this way, it could be shown
that there is a relationship between the strain rate and the flexural stress and stiffness of
the composites. As the strain rate increases, there is an increase in bending stress and
stiffness.Os materiais compósitos estão cada vez mais a ser utilizados na indústria aeronáutica. Apesar das fibras de carbono serem as mais resistentes e as mais usadas no setor
aeronáutico, estas fibras colapsam de maneira bastante repentina devido a sua natureza
frágil levando a danos catastróficos. Com o intuito de minimizar este efeito utilizase uma
técnica alternativa que consiste em combinar estas fibras com outro tipo menos frágil,
como por exemplo a fibra de kevlar, de modo a obterem material com um comportamento
mais dúctil. Como o comportamento viscoelástico não é muito abordado na literatura
aberta disponível, este trabalho pretende então estudar esta propriedade mecânica em
vários compósitos híbridos envolvendo fibras de carbono, kevlar e vidro. Para o melhor
entendimento deste fenómeno estudouse igualmente o comportamento estático e tenacidade destes materiais. Para este propósito, o efeito da hibridização nas propriedades
de flexão, resistência ao cisalhamento interlaminar, fluência e relaxamento de tensões
foi estudado em dezoito combinações hibridas combinadas com uma matriz epoxídica.
Observouse que a hibridização pode criar um compósito mais tenaz e balanceado. A sequência de empilhamento tem uma influência significativa nas propriedades mecânicas
dos laminados. Como tal, para todos os testes mecânicos, as fibras de carbono são melhores na compressão se hibridizadas com kevlar e melhores em tensão se hibridizadas
com vidro. As fibras de vidro sempre apresentaram melhores resultados sob compressão
e as fibras de kevlar sempre apresentam melhores resultados sob tensão, independentemente da outra fibra com a qual são hibridizadas. Com essas posições no laminado, os
compósitos alcançam maior tensão e rigidez, mas menor deformação, maior resistência
ao cisalhamento interlaminar, menor fluência e menor relaxamento de tensão. Quanto
ao número de camadas de fibras, nas propriedades de flexão, uma menor percentagem de
kevlar no laminado resulta em maior tensão de flexão e resistência ao cisalhamento interlaminar. Porém, para o comportamento viscoelástico dos compósitos híbridos, o número
de camadas não tem influência direta nos valores de fluência e relaxamento de tensão,
uma vez que ocorrem rearranjos moleculares. Além disso, foi feito um estudo das propriedades de flexão para diferentes taxas de deformação em compósitos de fibra de carbono e compósitos de fibra de vidro. Desta forma, pôdese mostrar que existe uma relação
entre a taxa de deformação e a tensão de flexão e rigidez dos compósitos. Com o aumento
da taxa de deformação, ocorre um aumento da tensão de flexão e da rigidez
Scalar extensions of derived categories and non-Fourier-Mukai functors
Orlov's famous representability theorem asserts that any fully faithful exact functor between the bounded derived categories of coherent sheaves on smooth projective varieties is a Fourier–Mukai functor. This result has been extended by Lunts and Orlov to include functors from perfect complexes to quasi-coherent complexes. In this paper we show that the latter extension is false without the full faithfulness hypothesis. Our results are based on the properties of scalar extensions of derived categories, whose investigation was started by Pawel Sosna and the first author
A k-linear triangulated category without a model
In this paper we give an example of a triangulated category, linear over a field of characteristic zero, which does not carry a DG-enhancement. The only previous examples of triangulated categories without a model have been constructed by Muro, Schwede and Strickland. These examples are however not linear over a field
Adsorption of cobalt (II) 5,10,15,20-tetrakis(2-aminophenyl)-porphyrin onto copper substrates: characterization and impedance studies for corrosion inhibition
An investigation into whether poaching creates an ecological trap for white rhinoceros in Hluhluwe-iMfolozi Park, South Africa
In an ecological trap, animals choose habitat based upon cues that once led members of their species to optimal habitat, but now lead to habitat where individual fitness is reduced because of changing conditions. The southern white rhinoceros (Ceratotherium simum) is a threatened species due to poaching for its keratin horn. Here, I investigate the degree to which poaching creates an ecological trap for white rhinoceros in South Africa’s Hluhluwe-iMfolozi Park. To this end, I develop a model for white rhino habitat preference and analyse rhino movement through time over the gradient of habitat preference and poaching risk. Three aspects of the ecological trap scenario were assessed: environmental habitat quality in hotspots relative to cold-spots for poaching, rhino movement into high-quality habitat regardless of poaching risk, and the impact of poaching on white rhino fitness at the population level. I found that while high quality habitat exists in poaching hotspots, net colonization was higher into high quality habitat in low-risk areas for poaching than in high-risk poaching hotspots. Further, fitness has declined for rhino populations in hotspots relative to cold-spots of the same quality, and likely represents a loss in fitness to the park population as a whole. While at this time there is little evidence to suggest rhino are pulled away from high quality cold-spots to areas at high risk for poaching, continued monitoring of the habitat quality-risk gradient is crucial to understanding and managing the white rhino population in Hluhluwe-iMfolozi Park
Convergence and Divergence in Ada Cambridge’s A Woman’s Friendship
Although Ada Cambridge is a major writer of the colonial period, she has long been neglected in Australian literary history. Her serial novel A Woman’s Friendship, published in the Melbourne paper The Age (August-October 1889), was widely read and circulated and, as such, offered a way in the social and gender debates of the time. This paper aims to reflect on Cambridge’s ambivalent representation of female characters and gender issues in the 1880s Australian society, oscillating between convergence and divergence with conventions, and between conformism and radicalism
Unconventional Memoirs: Mary Fortune’s Account of Life on the Diggings
In “Twenty-Six Years Ago: or, the Diggings from ’55,” published in The Australian Journal (1882-83), Waif Wander (Mary Fortune’s pen name) provides an autobiographical account of an unconventional woman’s life on the Australian goldfields. This article seeks to stress the unconventionality of Mary Fortune’s memoirs, written beyond norms of genre and gender, in order to contribute to their re-evaluation. It addresses Fortune’s exclusion from the Australian literary histories as well as her eccentric and marginal way of life
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