Social identity, self-categorization, and the communication of group norms

We articulate the role of norms within the social identity perspective as a basis for theorizing a number of manifestly communicative phenomena. We describe how group norms are cognitively represented as context-dependent prototypes that capture the distinctive properties of groups. The same process that governs the psychological salience of different prototypes, and thus generates group normative behavior, can be used to understand the formation, perception, and diffusion of norms, and also how some group members, for example, leaders, have more normative influence than others. life illustrate this process across a number of phenomena and make suggestions for future interfaces between the social identity perspective and communication research. We believe that the social identity approach represents a truly integrative force for the communication discipline.

O PLANEJAMENTO EDUCACIONAL E A CONSTRUÇÃO TEÓRICO-PRÁTICA DA AUTONOMIA DO EDUCADOR

Trata-se de uma pesquisa de mestrado que tem por objetivo discutir os processos de planejamento educacional e de formação continuada do professor de Ensino Médio, envolvendo aspectos do trabalho coletivo dos educadores/professores, o momento do registro, os saberes docentes e do coordenador pedagógico e a construção da autonomia docente. O trabalho visa responder às seguintes questões: por que é tão difícil que o trabalho de planejamento, a troca de experiência, o estudo conjunto aconteçam na escola, mesmo quando são destinadas horas remuneradas para esses fins? Por que as horas destinadas ao planejamento, à troca de experiências, à avaliação do trabalho pedagógico e à formação continuada não são bem aproveitadas na escola? Muitos governos estaduais e municipais e mesmo muitos mantenedores de instituições privadas, geralmente "enfiam goela abaixo" dos educadores os seus projetos, não solicitando dos mesmos a contribuição, e o que é mais importante, o envolvimento no processo de elaboração. Os professores, ao resistirem aos processos de planejamento, estão reagindo a essa forma autoritária de desencadear políticas? Se não, que razões levam o professor a rejeitar mudanças em sua prática? Quais questionamentos fazem os professores em torno do planejamento/plano? A dissertação tem como objetivo geral analisar as respostas apresentadas da sondagem exploratória realizada no início da pesquisa, com quatro professores de uma mesma escola de Ensino Médio da rede particular, e relacioná-las aos estudos bibliográficos apresentados a partir de diversos autores estudiosos no assunto. Pretende, ainda, enfocar o "como" os professores poderiam utilizar melhor o processo do trabalho coletivo para um movimento reflexivo do ato de educar; o "quanto" as horas previstas e remuneradas poderiam contribuir para as discussões sobre o processo ensino-aprendizagem-avaliação. Como procedimento metodológico, além da entrevista inicial, foi realizado um estudo bibliográfico sobre a importância da palavra a partir dos estudos de Freud e, em seguida, da abordagem multirrefrencial por permitir um olhar plural e mais humano sobre os processos educacionais. Foram apresentados estudos sobre os conceitos atribuídos às políticas de planejamento curricular: o planejamento e o plano de ensino - práticas construídas no cotidiano. Como resultados, mesmo que provisórios, apontamos para: o trabalho coletivo no espaço organizado e garantido pelos gestores da escola; a valorização da memória e autoria docente, para a reflexão de práticas, a visibilidade do trabalho e o resultado pedagógico. O trabalho ainda considera a importância da formação contínua, planejada em momentos remunerados e garantidos pela instituição, a importância da construção dos saberes, docentes e do coordenador pedagógico e a historicidade das práticas de registro dos planos como aspectos inerentes a um projeto pedagógico e que devem ser reconhecidos, valorizados e estimulados pelas políticas institucionais.(AU)

O COORDENADOR PEDAGÓGICO E A FORMAÇÃO CONTINUADA DOS PROFISSIONAIS DE CRECHE: POSSIBILIDADES E DESAFIOS

O Plano Nacional de Educação (PNE) determina que 50% das crianças de 0 a 3 anos tenham vagas garantidas em Creches Públicas e a Lei do Piso n. 11.738/08 apresenta, em seu parágrafo quarto, que na composição da jornada de trabalho do professor observar-se-á um terço destinado à formação. A determinação destas mudanças aumenta a preocupação e responsabilidade em qualificar a formação continuada nestas instituições, as quais ainda sentem o peso dos vários anos de negligência. Pela atualidade e importância temática, a presente abordagem investiga a trajetória formativa e profissional de educadores de Creche, com o objetivo de possibilitar a reflexão e a análise sobre as estratégias utilizadas na formação continuada, bem como um debate dialético entre as práticas e as teorias trazidas nos estudos e pesquisas. Através da metodologia da Pesquisa de Campo de Natureza Qualitativa, buscou-se, ao contatar profissionais de cinco creches do município de São Bernardo do Campo, investigar a seguinte questão: De que forma o Coordenador Pedagógico que atua em creche tem contribuído, ou não, com a formação de profissionais reflexivos, pesquisadores e autores da própria prática? No intuito de responder a questão, foram realizadas entrevistas com cinco Coordenadoras Pedagógicas (CPs), três Professoras e dois Auxiliares em Educação e, em vista de maiores subsídios necessários ao debate, também foram entrevistadas uma Coordenadora de um curso de Pedagogia, com a finalidade de ampliar os conhecimentos sobre o curso de Pedagogia na atualidade, e uma Gestora (Chefe de Região) de São Bernardo do Campo, a fim de entender o olhar que o município tem hoje para a Creche. É importante ressaltar que o foco das entrevistas foi o trabalho desenvolvido pelo CP e que o trabalho investigativo junto aos demais profissionais envolvidos auxiliam na busca e obtenção de respostas para os questionamentos que levaram à construção deste trabalho. Os referenciais teóricos, desenvolvidos através da metodologia da Pesquisa de Natureza Bibliográfica e Documental para a revisão da literatura disponível sobre o tema, estão ancorados em Almeida e Placco (2002; 2010; 2011) que observam o papel do CP sob diversos aspectos; Day (1999) que discute os desafios fundamentais a serem considerados na formação; Fullan e Hargreaves (2002) que apresentam questionamentos sobre as estratégias formativas; Nóvoa (2009) ao investigar sobre a formação permanente dos professores; Perrenoud e Thurler (2002) que destacam novos paradigmas na formação dos professores; Vasconcellos (2009) que observa as articulações necessárias ao trabalho do CP; Campos et al (2011) que mostram a qualidade da Educação Infantil no país, entre outros. A análise dos conteúdos das entrevistas realizadas indica que a formação continuada avança gradativamente e, este mérito é dado, em grande parte, à formação que os gestores vêm recebendo e às parcerias produtivas que se estabelecem no processo, porém, os estudos e pesquisas teóricas apontam que muito ainda precisa ser feito e sinalizam mudanças imprescindíveis e que sejam capazes de impulsionar a formação a sair do tradicionalismo, tornando-se mais voltada à reflexão e humanização.

A POLÍTICA DE FORMAÇÃO DO PROFESSOR DE QUÍMICA

Considerando as inúmeras fragilidades em relação à minha própria formação de professora de Química, considerando também as disposições legais e as orientações curriculares das políticas educacionais atuais que incorporam aportes teóricos fundamentais para que a aprendizagem se concretize e considerando ainda que as transformações nos procedimentos pedagógicos não acompanham o desenvolvimento das ciências da educação, este estudo teve com foco de investigação os seguintes problemas: a) os professores de Química que atuam no Ensino Médio estão devidamente formados para enfrentar as exigências colocadas pelos Parâmetros Curriculares Nacional para o Ensino Médio (PCNEM) e a realidade vivida na escola pública? b) O que o professor faz para que o aluno aprenda Química? c) A política de formação do professor de Química dá conta de formar o químico educador? Para obter os dados para responder a estas questões, recorri a uma pesquisa qualitativa de cunho etnográfico, aplicando questionários a um grupo de 12 professores de Química que atuam no Ensino Médio da rede pública estadual da Grande São Paulo. As questões do questionário foram agrupadas em três categorias: aprendizagem de conceitos, aprendizagem de procedimentos e aprendizagem de valores. No anos de 2001, essas categorias foram utilizadas por García Barros e Martinez Losada em pesquisa com professores da educação básica na Espanha, com ênfase nas duas primeiras, para averiguar que tipo de atividades se realiza habitualmente no ensino de Química e para conhecer a importância que os professores respondentes atribuem aos procedimentos que utilizam no processo de ensino. Os dados coletados, analisados à luz de contribuições dos estudiosos que compõem o corpo teórico deste estudo e das propostas contidas nos PCNEM, evidenciam que o saber fazer do professor, como o definem Carvalho e Perez (2002), é fruto de uma formação inicial precária e da quase inexistência de processos de formação continuada na escola.(AU)

FORMAÇÃO CONTINUADA: POR QUE OS PROFESSORES NÃO LÊEM?

Neste estudo, busco desvelar a relação entre formação continuada de professores e a prática de leitura, considerando a instituição do ato de ler e suas implicações e relacionando conceitos, fatos, causas e efeitos. Apresento uma retrospectiva da iniciação às letras no mundo, pontuando conceitos e as diferentes metodologias utilizadas para o desenvolvimento da indissociável dupla leitura e escrita, considerando os aspectos sociais e as exigências de cada época. Tomo como base os escritos de Alberto Manguel, Uma história da leitura, e a obra Formação do Brasil Colonial, de Arno Wheling & Maria José C.M. Wheling, que direcionam a síntese da implementação da aquisição de leitura e escrita no Brasil e conduzem o discurso para um breve histórico da formação continuada na rede estadual de São Paulo. A instituição da formação continuada e a concepção do conceito de formação continuada, segundo a literatura específica, permitem a percepção de algumas mudanças nas representações sociais assumidas pelos docentes em relação à educação, ao processo de ensino e aprendizagem e ao seu papel como indivíduo ativo historicamente situado. Exemplifico a formação continuada de professores com a análise do programa EMR Ensino Médio em Rede. O estudo inclui inicialmente a observação, seguida da análise, das opiniões expressas em questionários e entrevistas de professores com participação efetiva no programa EMR. A história da vida de três professores, enfocando a formação leitora, auxilia no entendimento do processo de leitura e sua influência na constituição dos sujeitos enquanto leitores e o impacto da prática de leitura em sua atividade docente. A identificação das situações que envolvem o processo de leitura e escrita, bem como dos elementos que corroboram ou não para seu aprimoramento, contribui para uma discussão relevante para a efetiva ampliação da prática de leitura.(AU)

FORMAÇÃO DE PROFESSORES(AS) E RELAÇÕES INTERPESSOAIS: UM ESTUDO EM SÃO BERNARDO DO CAMPO

Este trabalho investiga as relações interpessoais entre professores(as) e formadores(as), tendo como foco o(a) Professor(a) de Apoio Pedagógico (PAP), na Prefeitura de São Bernardo do Campo. Analisa a complexidade que envolve o trabalho formativo e verifica as relações estabelecidas entre estes pares: hierarquia, intervenções formativas, relações de poder, trabalho coletivo e veiculações de conhecimento. O(a) PAP ao final do ano é avaliado(a), num passado recente, pelo grupo, e atualmente, pelo(a) diretor(a) e referendado a assumir a função no ano seguinte, dando continuidade ao seu trabalho ou não. Se não referendado, volta para a sala de aula. Observa-se que alguns(mas) PAP s vem conseguindo ser referendados(as) e mantém-se há dez anos na função. A questão desta pesquisa é: O que leva o(a) formador(a) de professores(as) a conseguir tal legitimidade do grupo? Foram realizadas entrevistas, com vistas a uma abordagem metodológica de Histórias de Vida com análise das trajetórias formativas e profissionais de sete PAP´s (três que estão na função desde 1998, quando da sua criação, e quatro que estão na função desde 2007). Os referenciais teóricos estão ancorados em Antònio Nóvoa quando discute identidade e autoconhecimento do(a) professor(a); Paulo Freire na abordagem sobre dialogicidade como prática da liberdade; Madalena Freire quando analisa a resistência e constituição de grupo. A conclusão da pesquisa aponta que para conquistar a legitimidade do grupo, o(a) formador(a) deve estar atento para não cair na armadilha da burocracia, a qual por muitos anos tem feito parte das instituições escolares, promovendo enquadramento e controle; também não deve se aprisionar na arrogância que a posição gestora pode suscitar. Para conquistar a legitimidade do grupo, a capacidade de enfrentamento dos medos e conflitos através do diálogo como prática da liberdade é fundamental e, neste sentido, construir uma identidade formadora da qual faz parte o ouvir atento e o observar apurado dos movimentos do grupo, demanda uma postura ética em que as relações se constroem através do respeito, amorosidade, fé nos homens e criticidade.(AU)

Development and evaluation of a non-destructive adhesion test

The object of this work was to further develop the idea introduced by Muaddi et al (1981) which enables some of the disadvantages of earlier destructive adhesion test methods to be overcome. The test is non-destructive in nature but it does need to be calibrated against a destructive method. Adhesion is determined by measuring the effect of plating on internal friction. This is achieved by determining the damping of vibrations of a resonating specimen before and after plating. The level of adhesion was considered by the above authors to influence the degree of damping. In the major portion of the research work the electrodeposited metal was Watt's nickel, which is ductile in nature and is therefore suitable for peel adhesion testing. The base metals chosen were aluminium alloys S1C and HE9 as it is relatively easy to produce varying levels of adhesion between the substrate and electrodeposited coating by choosing the appropriate process sequence. S1C alloy is the commercially pure aluminium and was used to produce good adhesion. HE9 aluminium alloy is a more difficult to plate alloy and was chosen to produce poorer adhesion. The "Modal Testing" method used for studying vibrations was investigated as a possible means of evaluating adhesion but was not successful and so research was concentrated on the "Q" meter. The method based on the use of a "Q" meter involves the principle of exciting vibrations in a sample, interrupting the driving signal and counting the number of oscillations of the freely decaying vibrations between two known preselected amplitudes of oscillations. It was not possible to reconstruct a working instrument using Muaddi's thesis (1982) as it had either a serious error or the information was incomplete. Hence a modified "Q" meter had to be designed and constructed but it was then difficult to resonate non-magnetic materials, such as aluminium, therefore, a comparison before and after plating could not be made. A new "Q" meter was then developed based on an Impulse Technique. A regulated miniature hammer was used to excite the test piece at the fundamental mode instead of an electronic hammer and test pieces were supported at the two predetermined nodal points using nylon threads. This instrument developed was not very successful at detecting changes due to good and poor pretreatments given before plating, however, it was more sensitive to changes at the surface such as room temperature oxidation. Statistical analysis of test results from untreated aluminium alloys show that the instrument is not always consistent, the variation was even bigger when readings were taken on different days. Although aluminium is said to form protective oxides at room temperature there was evidence that the aluminium surface changes continuously due to film formation, growth and breakdown. Nickel plated and zinc alloy immersion coated samples also showed variation in Q with time. In order to prove that the variations in Q were mainly due to surface oxidation, aluminium samples were lacquered and anodised Such treatments enveloped the active surfaces reacting with the environment and the Q variation with time was almost eliminated especially after hard anodising. This instrument detected major differences between different untreated aluminium substrates.Also Q values decreased progressively as coating thicknesses were increased. This instrument was also able to detect changes in Q due to heat-treatment of aluminium alloys.

Using min-sum loopy belief propagation for decentralised supply chain formation

Modern business trends such as agile manufacturing and virtual corporations require high levels of flexibility and responsiveness to consumer demand, and require the ability to quickly and efficiently select trading partners. Automated computational techniques for supply chain formation have the potential to provide significant advantages in terms of speed and efficiency over the traditional manual approach to partner selection. Automated supply chain formation is the process of determining the participants within a supply chain and the terms of the exchanges made between these participants. In this thesis we present an automated technique for supply chain formation based upon the min-sum loopy belief propagation algorithm (LBP). LBP is a decentralised and distributed message-passing algorithm which allows participants to share their beliefs about the optimal structure of the supply chain based upon their costs, capabilities and requirements. We propose a novel framework for the application of LBP to the existing state-of-the-art case of the decentralised supply chain formation problem, and extend this framework to allow for application to further novel and established problem cases. Specifically, the contributions made by this thesis are: • A novel framework to allow for the application of LBP to the decentralised supply chain formation scenario investigated using the current state-of-the-art approach. Our experimental analysis indicates that LBP is able to match or outperform this approach for the vast majority of problem instances tested. • A new solution goal for supply chain formation in which economically motivated producers aim to maximise their profits by intelligently altering their profit margins. We propose a rational pricing strategy that allows producers to earn significantly greater profits than a comparable LBP-based profitmaking approach. • An LBP-based framework which allows the algorithm to be used to solve supply chain formation problems in which goods are exchanged in multiple units, a first for a fully decentralised technique. As well as multiple-unit exchanges, we also model in this scenario realistic constraints such as factory capacities and input-to-output ratios. LBP continues to be able to match or outperform an extended version of the existing state-of-the-art approach in this scenario. • Introduction of a dynamic supply chain formation scenario in which participants are able to alter their properties or to enter or leave the process at any time. Our results suggest that LBP is able to deal easily with individual occurences of these alterations and that performance degrades gracefully when they occur in larger numbers.

Indwelling catheters and medical implants with FXIIIa inhibitors:a novel approach to the treatment of catheter and medical device-related infections

Central venous catheters (CVCs) are being utilized with increasing frequency in intensive care and general medical wards. In spite of the extensive experience gained in their application, CVCs are related to the long-term risks of catheter sheath formation, infection, and thrombosis (of the catheter or vessel itself) during catheterization. Such CVC-related-complications are associated with increased morbidity, mortality, duration of hospitalization, and medical care cost [1]. The present study incorporates a novel group of Factor XIIIa (FXIIIa, plasma transglutaminase) inhibitors into a lubricious silicone elastomer in order to generate an optimized drug delivery system whereby a secondary sustained drug release profile occurs following an initial burst release for catheters and other medical devices. We propose that the incorporation of FXIIIa inhibitors into catheters, stents, and other medical implant devices would reduce the incidence of catheter sheath formation, thrombotic occlusion, and associated staphylococcal infection. This technique could be used as a local delivery system for extended release with an immediate onset of action for other poorly aqueous soluble compounds. © 2012 Elsevier B.V. All rights reserved.

Uncatalysed and potassium-catalysed pyrolysis of the cell-wall constituents of biomass and their model compounds

Cell-wall components (cellulose, hemicellulose (oat spelt xylan), lignin (Organosolv)), and model compounds (levoglucosan (an intermediate product of cellulose decomposition) and chlorogenic acid (structurally similar to lignin polymer units)) have been investigated to probe in detail the influence of potassium on their pyrolysis behaviours as well as their uncatalysed decomposition reaction. Cellulose and lignin were pretreated to remove salts and metals by hydrochloric acid, and this dematerialized sample was impregnated with 1% of potassium as potassium acetate. Levoglucosan, xylan and chlorogenic acid were mixed with CHCOOK to introduce 1% K. Characterisation was performed using thermogravimetric analysis (TGA) and differential thermal analysis (DTA). In addition to the TGA pyrolysis, pyrolysis-gas chromatography-mass spectrometry (PY-GC-MS) analysis was introduced to examine reaction products. Potassium-catalysed pyrolysis has a huge influence on the char formation stage and increases the char yields considerably (from 7.7% for raw cellulose to 27.7% for potassium impregnated cellulose; from 5.7% for raw levoglucosan to 20.8% for levoglucosan with CHCOOK added). Major changes in the pyrolytic decomposition pathways were observed for cellulose, levoglucosan and chlorogenic acid. The results for cellulose and levoglucosan are consistent with a base catalysed route in the presence of the potassium salt which promotes complete decomposition of glucosidic units by a heterolytic mechanism and favours its direct depolymerization and fragmentation to low molecular weight components (e.g. acetic acid, formic acid, glyoxal, hydroxyacetaldehyde and acetol). Base catalysed polymerization reactions increase the char yield. Potassium-catalysed lignin pyrolysis is very significant: the temperature of maximum conversion in pyrolysis shifts to lower temperature by 70 K and catalysed polymerization reactions increase the char yield from 37% to 51%. A similar trend is observed for the model compound, chlorogenic acid. The addition of potassium does not produce a dramatic change in the tar product distribution, although its addition to chlorogenic acid promoted the generation of cyclohexane and phenol derivatives. Postulated thermal decomposition schemes for chlorogenic acid are presented. © 2008 Elsevier B.V. All rights reserved.

Molecular and genetic evidence for abnormalities in the nodes of Ranvier in schizophrenia

Context: Genetic, neuroimaging, and molecular neurobiological evidence support the hypothesis that the disconnectivity syndrome in schizophrenia (SZ) could arise from failures of saltatory conduction and abnormalities at the nodes of Ranvier (NOR) interface where myelin and axons interact. Objective: To identify abnormalities in the expression of oligodendroglial genes and proteins that participate in the formation, maintenance, and integrity of the NOR in SZ. Design: The messenger RNA (mRNA) expression levels of multiple NOR genes were quantified in 2 independent postmortem brain cohorts of individuals with SZ, and generalizability to protein expression was confirmed. The effect of the ANK3 genotype on the mRNA expression level was tested in postmortem human brain. Case-control analysis tested the association of the ANK3 genotype with SZ. The ANK3 genotype's influence on cognitive task performance and functional magnetic resonance imaging activation was tested in 2 independent cohorts of healthy individuals. Setting: Research hospital. Patients: Postmortem samples from patients with SZ and healthy controls were used for the brain expression study (n=46) and the case-control analysis (n=272). Healthy white men and women participated in the cognitive (n=513) and neuroimaging (n=52) studies. Main Outcome Measures: The mRNA and protein levels in postmortem brain samples, genetic association with schizophrenia, cognitive performance, and blood oxygenation level-dependent functional magnetic resonance imaging. Results: The mRNA expression of multiple NOR genes was decreased in schizophrenia. The ANK3 rs9804190 C allele was associated with lower ANK3 mRNA expression levels, higher risk for SZ in the case-control cohort, and poorer working memory and executive function performance and increased prefrontal activation during a working memory task in healthy individuals. Conclusions: These results point to abnormalities in the expression of genes and protein associated with the integrity of the NOR and suggest them as substrates for the disconnectivity syndrome in SZ. The association of ANK3 with lower brain mRNA expression levels implicates a molecular mechanism for its genetic, clinical, and cognitive associations with SZ. ©2012 American Medical Association. All rights reserved.

Phenomenology, psychoanalysis, and subject identity: Locating Narcissus and Proteus in the text

This paper examines the ways in which subject identity obtains in either philosophical or psychoanalytical theory, which subject may be duplicated—and disclosed—in literary narratives via their principles and ideas. ^ The technique has a double approach. First, the thesis examines subject formation in (and by) language, through psychoanalysis as it draws upon abiding mythic resources, phenomenological methods and aims (e.g., the subject as consciousness intending its object), and the existentialist turn. It then brings these ideas and principles to bear upon an analysis of literary works as cultural expressions of these identities. ^ Beginning with scientific and philosophical referents (as opposed to the somewhat ‘inclusive’ analysis of, for example, the New Criticism or explication de texte), allows for alternative readings not previously available to either author or reader. ^ Access to extra-literary sources, theories, and ideas enables a ‘reading’ of the subject on a par with one existing in the Life-World. ^

Plasma and cold sprayed aluminum carbon nanotube composites: Quantification of nanotube distribution and multi-scale mechanical properties

Carbon nanotubes (CNT) could serve as potential reinforcement for metal matrix composites for improved mechanical properties. However dispersion of carbon nanotubes (CNT) in the matrix has been a longstanding problem, since they tend to form clusters to minimize their surface area. The aim of this study was to use plasma and cold spraying techniques to synthesize CNT reinforced aluminum composite with improved dispersion and to quantify the degree of CNT dispersion as it influences the mechanical properties. Novel method of spray drying was used to disperse CNTs in Al-12 wt.% Si prealloyed powder, which was used as feedstock for plasma and cold spraying. A new method for quantification of CNT distribution was developed. Two parameters for CNT dispersion quantification, namely Dispersion parameter (DP) and Clustering Parameter (CP) have been proposed based on the image analysis and distance between the centers of CNTs. Nanomechanical properties were correlated with the dispersion of CNTs in the microstructure. Coating microstructure evolution has been discussed in terms of splat formation, deformation and damage of CNTs and CNT/matrix interface. Effect of Si and CNT content on the reaction at CNT/matrix interface was thermodynamically and kinetically studied. A pseudo phase diagram was computed which predicts the interfacial carbide for reaction between CNT and Al-Si alloy at processing temperature. Kinetic aspects showed that Al4C3 forms with Al-12 wt.% Si alloy while SiC forms with Al-23wt.% Si alloy. Mechanical properties at nano, micro and macro-scale were evaluated using nanoindentation and nanoscratch, microindentation and bulk tensile testing respectively. Nano and micro-scale mechanical properties (elastic modulus, hardness and yield strength) displayed improvement whereas macro-scale mechanical properties were poor. The inversion of the mechanical properties at different scale length was attributed to the porosity, CNT clustering, CNT-splat adhesion and Al 4C3 formation at the CNT/matrix interface. The Dispersion parameter (DP) was more sensitive than Clustering parameter (CP) in measuring degree of CNT distribution in the matrix.

Integrated Carbon Budget Models for the Everglades Terrestrial-Coastal-Oceanic Gradient: Current Status and Needs for Inter-Site Comparisons

Recent studies suggest that coastal ecosystems can bury significantly more C than tropical forests, indicating that continued coastal development and exposure to sea level rise and storms will have global biogeochemical consequences. The Florida Coastal Everglades Long Term Ecological Research (FCE LTER) site provides an excellent subtropical system for examining carbon (C) balance because of its exposure to historical changes in freshwater distribution and sea level rise and its history of significant long-term carbon-cycling studies. FCE LTER scientists used net ecosystem C balance and net ecosystem exchange data to estimate C budgets for riverine mangrove, freshwater marsh, and seagrass meadows, providing insights into the magnitude of C accumulation and lateral aquatic C transport. Rates of net C production in the riverine mangrove forest exceeded those reported for many tropical systems, including terrestrial forests, but there are considerable uncertainties around those estimates due to the high potential for gain and loss of C through aquatic fluxes. C production was approximately balanced between gain and loss in Everglades marshes; however, the contribution of periphyton increases uncertainty in these estimates. Moreover, while the approaches used for these initial estimates were informative, a resolved approach for addressing areas of uncertainty is critically needed for coastal wetland ecosystems. Once resolved, these C balance estimates, in conjunction with an understanding of drivers and key ecosystem feedbacks, can inform cross-system studies of ecosystem response to long-term changes in climate, hydrologic management, and other land use along coastlines.

Plasma And Cold Sprayed Aluminum Carbon Nanotube Composites: Quantification Of Nanotube Distribution And Multi-Scale Mechanical Properties

Carbon nanotubes (CNT) could serve as potential reinforcement for metal matrix composites for improved mechanical properties. However dispersion of carbon nanotubes (CNT) in the matrix has been a longstanding problem, since they tend to form clusters to minimize their surface area. The aim of this study was to use plasma and cold spraying techniques to synthesize CNT reinforced aluminum composite with improved dispersion and to quantify the degree of CNT dispersion as it influences the mechanical properties. Novel method of spray drying was used to disperse CNTs in Al-12 wt.% Si pre-alloyed powder, which was used as feedstock for plasma and cold spraying. A new method for quantification of CNT distribution was developed. Two parameters for CNT dispersion quantification, namely Dispersion parameter (DP) and Clustering Parameter (CP) have been proposed based on the image analysis and distance between the centers of CNTs. Nanomechanical properties were correlated with the dispersion of CNTs in the microstructure. Coating microstructure evolution has been discussed in terms of splat formation, deformation and damage of CNTs and CNT/matrix interface. Effect of Si and CNT content on the reaction at CNT/matrix interface was thermodynamically and kinetically studied. A pseudo phase diagram was computed which predicts the interfacial carbide for reaction between CNT and Al-Si alloy at processing temperature. Kinetic aspects showed that Al4C3 forms with Al-12 wt.% Si alloy while SiC forms with Al-23wt.% Si alloy. Mechanical properties at nano, micro and macro-scale were evaluated using nanoindentation and nanoscratch, microindentation and bulk tensile testing respectively. Nano and micro-scale mechanical properties (elastic modulus, hardness and yield strength) displayed improvement whereas macro-scale mechanical properties were poor. The inversion of the mechanical properties at different scale length was attributed to the porosity, CNT clustering, CNT-splat adhesion and Al4C3 formation at the CNT/matrix interface. The Dispersion parameter (DP) was more sensitive than Clustering parameter (CP) in measuring degree of CNT distribution in the matrix.