No description available.

The laser-induced molecular reorientation effect of guest-host dye-doped liquid crystals in isotropic phase has been studied by measuring the signals of optical Kerr effect using pulsed frequency-doubling Nd:YAG laser as a pumping source. The critical behavior near the isotropic-nematic transition has been observed when the temperature approaches to the phase transition of liquid crystal. The relaxation time constant is about several hundreds of ns as the temperature is far above the clearing point of liquid crystals and that is longer than 1500 ns as the temperature is close to the clearing point of liquid crystals. According to Landau¡¦s second phase transition theory, the interaction between liquid crystal molecules will be increased and the nonlinearity effect of liquid crystal will be enhanced when the temperature is near the clearing point of liquid crystal. The relaxation time constant of molecular reorientation is a function of viscosity and temperature of liquid crystal, the relationship can be fitted as£b0*exp(f/T)*(1/T-T*),where £b0 is the viscosity coefficient and T* is the clearing point of the sample. The optical Kerr signal is found to be proportional to the energy density of pumping source. The optical Kerr signal can be sustained as long as 20£gs when the energy density of pumping source reaches to 1J/cm sq. The enhancement of molecular reorientation effect is also observed by increasing the concentration of dye.

No description available.

No description available.

318f. / Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2013-04-25T17:42:08Z No. of bitstreams: 1 Tese Edmerson Reisseg.pdf: 1558890 bytes, checksum: d19f2bd3d3c2dd525a47274e570e351e (MD5) / Approved for entry into archive by Rodrigo Meirelles(rodrigomei@ufba.br) on 2013-06-06T19:00:21Z (GMT) No. of bitstreams: 1 Tese Edmerson Reisseg.pdf: 1558890 bytes, checksum: d19f2bd3d3c2dd525a47274e570e351e (MD5) / Made available in DSpace on 2013-06-06T19:00:21Z (GMT). No. of bitstreams: 1 Tese Edmerson Reisseg.pdf: 1558890 bytes, checksum: d19f2bd3d3c2dd525a47274e570e351e (MD5) Previous issue date: 2009 / Discutir a reorientação curricular na perspectiva da contextualização dos conhecimentos trabalhados pela escola e o lugar dedicado ao contexto na experiência educativa da Escola Rural de Massaroca – ERUM, localizada no Distrito Rural de Massaroca, em Juazeiro – BA, campo empírico da pesquisa, foi o que nos propomos neste trabalho. No referencial teórico aprofundamos conceitos fundamentais como contexto, educação contextualizada, currículo, educação do campo entre outros. O enfoque metodológico foi o fenomenológico e optamos pela de pesquisa participante de cunho qualitativo, tendo como técnicas de construção das informações a observação participante, a entrevista semi-estruturada e a análise documental. Os atores e atrizes da pesquisa foram os discentes e docentes, tendo como outras fontes de informação, a proposta pedagógica da ERUM e os Cadernos de Realidade elaborados pelos alunos. Entre as principais conclusões a que chegamos, a mais significativa foi compreender que, tanto na proposta pedagógica de reorientação curricular, quanto nas práticas educativas desenvolvidas na singularidade desta escola, o processo contextualização tem no contexto local, o ponto de partida para o desenvolvimento das ações pedagógicas, sendo que aí, o contexto assume o lugar das possibilidades de ampliação e da articulação dos conhecimentos e saberes locais com os globais, num diálogo permanente de aprendizagem, onde, a educação contextualizada não se reduz nem a perspectiva localista, que aprisiona os sujeitos e conhecimentos ao local, nem a universalista, que termina promovendo o desenraizamento dos contextos em que vivem os sujeitos, mas que efetiva-se numa práticas educativa de sentido e significado, não alienante dos alunos do campo, e que respeita os seus processos de desenvolvimento, as dinâmicas do campo e a relação orgânica entre as condições concretas de existência com o mundo do trabalho e a função social da escola na emancipação desses sujeitos. / Salvador

Each year, thousands of Chinese international students come to the United States to further their education. Most of them need to adjust their identities in some degrees to adapt to U.S. American social and cultural contexts. One key transition that is significantly under discussed and often ignored is Chinese international students’ adjustment into a racialized system in the U.S. Because of different racial and ethnic contexts in China, Chinese international students have to disorient from the racial and ethnic identity of their home country and adapt to and accept the U.S. American hierarchy of race and ethnicity. Lacking sufficient social and intellectual support, this process often leads to struggle, depression, and ambivalence amongst Chinese international students in relation to their identity and communication in the U.S. society. As a Chinese international student myself in the U.S., my own experiences with the shifting of racial and ethnic knowledge, and the struggles these experiences have produced in relation to my identity (ies), leads me to investigate this topic further. Thus, in this study I examine how members of a socio-cultural group that I identify with, Chinese international students, negotiate and make sense of their/our new racial and ethnic identity upon entering the cultural space of the U.S. Race and ethnicity, as social categories of identity and power, play out differently on bodies located in different spatial, national/historical and cultural contexts. The meanings and hierarchies of race and ethnicity presumed to be commonsense in one national context are not so in others. At the same time, in today’s increasingly mobile and globalizing world, how we make sense of and communicate race are acted upon by complex transnational forces. In recent years, there has been a growing interest among critical intercultural communication scholars to theorize race and ethnicity as social constructions and relations of power, but this theorization has mostly happened in the U.S. and Western contexts. The transnational and globalized dimensions of race and ethnicity still largely remain under studied (Shome, 2010). Tomlinson (2007) points out that, under the conditions of contemporary globalization, the global-local dialectical relationship could be interpreted as the global’s entry into the local; the local’s identity in the global; and the “disembedding” of the local to the global. This global-local dialectical approach provides me with a conceptual lens to look at how race and ethnicity are constructed, understood, and communicated in the climate of today’s increasingly transnational world. In this dissertation, I use critical complete-member ethnography (CCME), as “an insider-looking-in-and-out-critical approach” (Toyosaki, 2011, p. 66), to study the racial and ethnic identity dis/reorientation process of Chinese international students in the U.S. Specifically, I used ethnographic observations, interviews, and autoethnographic journaling as my research methods to examine the direct, subjective, and embodied experiences of my 13 participants and myself, negotiate and make sense of their-our new racial and ethnic identities upon entering a global-local dialectical context in the U.S. I strategically categorize my analysis into “disorientation” and “reorientation” from a critical intercultural perspective, and use CCME’s consensual-conflictual and cultural-individual dialectical theorizations to study their-our dis/reorientation processes. My findings reveal that Chinese international students’ previous “Chinese” racial and ethnic identity become invalid and even problematic in the U.S. context. We often find ourselves struggling with sentiments of exhaustion, cynicism, and nihilism (Warren & Fassett, 2012), and interconnected yet ambivalent double consciousness such as insider–outsider, Chinese-–people of color, and majority–minority in the racial and ethnic identity dis/reorientation processes. In my findings, it is clear that Chinese international students have experienced and formed a similar sense of uncomfortable-ness, lost-ness, and struggle in our racial and ethnic disorientation process when we enter the U.S. context from the Chinese context. My participants all reported that after they were geographically relocated in the U.S., they have gone through the phase of being lost and confused because they were unable to find or construct a new racial and ethnic selfhood that made them immediately fit into the U.S. society. After their initial transition and adjustment, they reported experiencing certain forms of racial and ethnic discrimination in the U.S. that they had never faced in China. These lived and embodied discriminatory experiences in the U.S., which often turned out to be very direct, uncomfortable and stressful, forced them to consciously disorient their normative identity and reorient themselves to becoming a racial and ethnic minority for the first time in their lives. At the same time, they felt that the new and transformative outcome they reoriented to was a temporary state rather than a permanent identity. As a result, most of them became more open-minded, and felt the need to keep constantly reorienting their sense of their racial and ethnic identities, meanings, and presences in the U.S. My findings demonstrate that contemporary globalization not only produces different interpretations of race and ethnicity, it also constantly alters possibilities and conditions of our real racial and ethnic experiences in the world. As we try to respond to racial and ethnic issues and crises in today’s transnational world, simply recognizing that race and ethnicity are socially constructed rather than biologically innate does not make racial and ethnic conflicts and problems easier to solve. The relative nature of race and ethnicity in different local and global contexts are far more intricate than we ever imagined. Therefore, it is necessary and useful to study how race and ethnicity are understood and communicated through the direct, embodied, and performative experiences of non-Western and non-White bodies in transnational and globalized contexts. This study also shows the possibility that might lie in pushing the concept of race and ethnicity beyond the hegemony of the ways it is understood and deployed in the U.S. and other Western cultural and social contexts. In this regard, this study opens up a constructive approach for critical intercultural scholarship to more effectively engage in understanding and communicating race and ethnicity in the global-local dialectical context of globalization.

Submitted by Liliane Ferreira (ljuvencia30@gmail.com) on 2018-09-25T12:39:15Z No. of bitstreams: 2 Dissertação - Milena de Oliveira Matos - 2018.pdf: 2506209 bytes, checksum: bfdb3acfab27ac25a55e97555788f3f4 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-09-26T11:39:25Z (GMT) No. of bitstreams: 2 Dissertação - Milena de Oliveira Matos - 2018.pdf: 2506209 bytes, checksum: bfdb3acfab27ac25a55e97555788f3f4 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-09-26T11:39:25Z (GMT). No. of bitstreams: 2 Dissertação - Milena de Oliveira Matos - 2018.pdf: 2506209 bytes, checksum: bfdb3acfab27ac25a55e97555788f3f4 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-08-28 / Considering that the curriculum is of central importance in the educational process and that it is configured as a field of study and research with theories that underlie and question it, the authors who discuss traditional, critical and post-critique of the curriculum, in addition to presenting a historical context of Fundamental Education in Brazil and in the Goiânia city from the years 1990 to the year 2014. The objective of this dissertation was to understand the understanding of the teachers of Natural Sciences of Elementary School II (6th to 9th year) of the State Schools of the Goiânia city regarding the construction of the curriculum, as well as curricular reorientations for the teaching of sciences. For that, used the statements of the teachers who work in State Schools of Goiânia in Elementary School II, registered in a mixed type questionnaire. Thus, it was possible to observe that the way education is organized is mechanical, "ritualistic" and does not contribute to the generation of an awareness of the educational process to the agents of education involved in the production and reproduction of the current educational system. The majority Elementary School II teachers do not feel they are participants in the curricular construction process, the utilization of the Reference Curriculum is done in an imposed and obligatory way, which according to them, withdraws your autonomy in the teaching of Natural Sciences. From this trajectory studies it is possible to conclude that it is appropriate to conceive the curriculum not as something technical, apolitical, a-historical, neutral, that concerns only the systematization of school knowledge, the organization of contents, the formulation of objectives, the choice of methodologies and the form of evaluation, but as a historical, uninterrupted and critical process. / Considerando que o currículo é de central importância no processo educacional, e que se configura como um campo de estudo e pesquisas com teorias que o fundamentam e o questionam, utilizou-se na fundamentação teórica os autores que discutem sobre as teorias tradicionais, críticas e pós-críticas do currículo, além de ser apresentada uma contextualização histórica da Educação Fundamental no Brasil e na cidade de Goiânia a partir dos anos 1990 até o ano de 2014. Objetivou-se nesta dissertação conhecer a compreensão dos docentes de Ciências da Natureza do Ensino Fundamental II (6⁰ ao 9⁰ ano) da Rede Estadual da cidade de Goiânia a respeito da construção do currículo, bem como das reorientações curriculares para o ensino de ciências. Para tanto, foram utilizadas as falas dos docentes que atuam em Escolas Estaduais de Goiânia no Ensino Fundamental II, registradas em questionário do tipo misto. Desse modo, foi possível observar que a maneira como a educação está organizada é mecânica, “ritualista” e que não contribui para a geração de uma conscientização do próprio processo educacional aos agentes da educação envolvidos na produção e reprodução do sistema educacional vigente. Os docentes do Ensino Fundamental II, em sua grande maioria, não se sentem participantes do processo de construção curricular, a utilização do Currículo Referência é feita de maneira imposta e obrigatória o que, segundo eles, retira sua autonomia no ensino de Ciências da Natureza. A partir dessa trajetória de estudos fica permitido concluir que é adequado conceber o currículo não como algo técnico, apolítico, a-histórico, neutro, que diz respeito apenas à sistematização de conhecimentos escolares, à organização de conteúdos, à formulação de objetivos, à escolha de metodologias e à forma de avaliação, mas como um processo histórico, ininterrupto e crítico.

Insufficient literature exists in the area of incremental and revolutionary change to explain and predict the convergence and reorientation phenomena happening in organizations. The process of strategic reorientation involves the internal organizational complexities of fast-paced (within two years) changes in competitive strategy as a necessary condition coupled with changes in at least two of organization structure, power distribution, and control systems. Antecedent forces believed to influence the discontinuous change process include industry sales turbulence, structural inertia/firm size, firm past financial performance, CEO turnover, top management team turnover, management team heterogeneity, management environmental awareness, and external attributions for negative financial performance. Punctuated equilibrium was the foundational theory for this study in which a strategic reorientation model published in Strategic Management Journal was reconstructed. The research question was: What seem to be the significant time-based antecedent forces or conditions that lead to strategic reorientation? The study used two hierarchical logit regression models to analyze data gathered from COMPUSTAT PC Industrial Data Base and Compact Disclosure (CD-ROM) over the years 1987-1993 from the turbulent computer software and stable furniture industries. Qualitative data were found in 10-K reports and President's Letters in Annual Reports filed with the SEC and available on Laserdisclosure. The sample, exclusive of 3 multivariate outliers, included 74 software firms and 43 furniture firms for a pooled total of 117 firms. When separate industries were analyzed using the first of the Systat logit hierarchical regressions, results showed no statistically significant effects. By contrast, when data were pooled, the second hierarchical logit regression model, which included industry turbulence and firm size, showed these one-tailed statistically significant results: strategic reorientation is positively affected by prior industry turbulence and CEO turnover, but is negatively affected by prior top management team turnover and the interaction between industry turbulence and external attributions for negative financial performance.

The present Thesis explored spatial reorientation behaviour of three species of fish (the zebrafish Danio rerio, the redtail splitfin fish Xenotoca eiseni, the goldfish Carassius auratus) and one species of reptiles (the Hermann tortoise Testudo hermanni) to widely assess three issues: 1) the use of environmental geometry with and without landmarks; 2) the role of two geometric tasks, one driven by spontaneous behaviour (“social-cued memory task”) and the other by learning processes (“rewarded exit task”); 3) the involvement of extra-visual sensory channels in visual transparency conditions, and motion patterns. The present Thesis applied behavioural assessments and analyses to pursue a line of comparison, across species, methodologies, and sensory systems. As regards environmental geometry and landmarks in fish and tortoises (Chapter 2), the studies were carried out within several apparatuses, that is, a rectangular opaque arena or two different sized square opaque arenas or a transparent square arena, with conspicuous or local landmarks: Study 1, Conspicuous landmark (blue wall) in zebrafish; Study 2: Local landmarks (corner panels) in zebrafish; Study 3, Environmental geometry in tortoises; Study 4, Conspicuous landmark (blue wall) in tortoises. As regards spontaneous vs. acquired geometric spatial reorientation in fishes (Chapter 3), the studies were carried out within a rectangular or square transparent arena, with or without geometric cues or a 3D landmark: Study 5, Nonvisual environmental geometry in zebrafish, redtail splitfin fish, and goldfish; Study 6, Isolated environmental geometric cues in zebrafish; Study 7, 3D outside landmark (blue cylinder) in zebrafish. As regards extra-visual sensory systems and motion patterns in fish (Chapter 4), one study was carried out within a rectangular transparent arena: Study 8, Lateral line pharmacological ablation in zebrafish. In respect of comparisons among species, overall results suggested that zebrafish, redtail splitfin fish, and goldfish reoriented similarly through transparent surfaces, which defined a distinctive global shape, supporting spatial reorientation under undefined situations (e.g., seek out food within a visually lacking and unenriched environment) as a shared skill among teleosts, despite ecological specificities. Likewise, the Hermann tortoise reoriented within a geometric environment with precision to meet a survival need, suggesting that even non-nomadic species that hibernate for long can benefit from orientation by extended terrain surfaces. In respect of memory tests (“working” vs. “reference”, spontaneous vs. acquired), overall results indicated that the rewarded exit task designed to train fish and tortoise to reorient required learning processes allowing them to overcome natural predispositions to improve other related abilities, such as landmark-use. The dissociation between working and reference memory in spatial domain must be considered highly dependent on task’s demands where attentional factors determine short-term memories and motivational states long-term ones. In respect of sensory channels and motion patterns, overall results revealed that fish and tortoises used modalities driven by touch, in synch with sight, to determine geometric parameters during spatial reorientation. Therefore, a promising link between other vertebrates and humans takes place, in consideration of orientation mechanisms used to face situations of visual deprivation or impairments. The present Thesis may even contribute to a general understanding of reorientation behaviour in phylogenetically remote vertebrate species, thus supporting the widespread use of geometry-grounded tools in everyday activities. This also provides comparative support among species that inhabit on Earth and share cognitive adaptations to deal with similar requests.

We have modelled structures and dynamics of hydrogen bond networks that form from imidazoles tethered to oligomeric aliphatic backbones in crystalline and glassy phases. We have studied the behavior of oligomers containing 5 or 10 imidazole groups. These systems have been simulated over the range 100-900 K with constantpressure molecular dynamics using the AMBER 94 force field, which was found to show good agreement with ab initio calculations on hydrogen bond strengths and imidazole rotational barriers. Hypothetical crystalline solids formed from packed 5-mers and 10-mers melt above 600 K, then form glassy solids upon cooling. Viewing hydrogen bond networks as clusters, we gathered statistics on cluster sizes and percolating pathways as a function of temperature, for comparison with the same quantities extracted from neat imidazole liquid. We have found that, at a given temperature, the glass composed of imidazole 5-mers shows the same hydrogen bond mean cluster size as that from the 10-mer glass, and that this size is consistently larger than that in liquid imidazole. Hydrogen bond clusters were found to percolate across the simulation cell for all glassy and crystalline solids, but not for any imidazole liquid. The apparent activation energy associated with hydrogen bond lifetimes in these glasses (9.3 kJ/mol) is close to that for the liquid (8.7 kJ/mol), but is substantially less than that in the crystalline solid (13.3 kJ/mol). These results indicate that glassy oligomeric solids show a promising mixture of extended hydrogen bond clusters and liquid-like dynamics. This study prompted a continued look at smaller oligomers (monomers, dimers, trimers, and pentamers). Using many of the above statistics we found that decreased chain length decreased the tendency to form global hydrogen bonding networks (percolation pathways). We also developed an reorientational correlation for the imidazole ring which allowed us to extract a timescale for reorientation. Smaller chains produce faster reorientation timescales and thus there is a trade off between faster reorientation dynamics and long global hydrogen bonding networks. Moreover we showed that homogeneity of chain length has no effect on hydrogen bonding statistics. Initial development on a multi-state empirical valence bond model has been to study proton transfer in liquid imidazole. We have shown that GAFF produces very large proton transfer barriers created by a highly repulsive N· · ·H VDW interaction at the transition point. In order to produce an acceptable fit to the potential energy surface while still producing stable dynamics this interaction must be turned off. This is in contrary to what is reported in the literature [14]. Using our model we have produced simulations with acceptable drift in the total energy (3.2 kcal/mol per ns) and negligible drift in the temperature (.12 K/ns).