1,072 research outputs found
Competitive exclusion of toxic cyanobacterial species by an allelopathic strain of Phormidium
A contribuição da competência relacional do empreendedor para aperfeiçoar a qualidade de relacionamento entre empresas de base tecnológica
ABSTRACTThe dynamic and interdependent nature of contemporary businesses requires a more open-minded conceptualization of entrepreneurial behavior, especially in regards to the acquisition of capital. It also requires an approach that is based in the study of relationships. Many partnerships fail due to the inability of an entrepreneur to develop and maintain successful relationships with partners on an interpersonal level. By means of content analysis, we describe how relationship building skills can enhance the quality of interpersonal relationships in high-tech businesses in the Recife metropolitan area. The results reveal that competence in maintaining relationships and the performance of the partnership are important aspects in terms of the quality of articulation among agents in a network. The relative bargaining power between partners and efforts at consensus building between agents are fundamental elements for negotiating and maintaining healthy relationships. An entrepreneur’s stability and endurance within social networks occurs primarily from competence in building and maintaining relationships and through the development of alliances. This is shown to be a key element for a successful partnership
Evaluation of the correlation between height and health of the spine in the student population in the age group of 16-19 years old: evaluation with spinal mouse
Physical processes contributing to harmful algal blooms in Saldanha Bay, South Africa
The study synthesises current understanding of the predominant physical processes responsible for the seasonality of harmful algal blooms, notably Alexandrium catenella and Dinophysis spp., in the nearshore environmentof Saldanha Bay on the west coast of South Africa. Saldanha Bay is one of the few naturally sheltered areas on the South African coastline suitable for in situ shellfish farming and is the major site for the productionof black mussel Mytilus galloprovincialis in South Africa. Mussel farming started there in 1985 and the present level of production is some 2 700 tons per annum. Since 1994, disruption of harvesting as a result of the presence of harmful algal species has been a regular late-summer phenomenon. Toxic blooms that are ultimately advected into the bay develop on the continental shelf to the north between 32°S and St Helena Bay, a region characterized by favourable conditions for dinoflagellate growth and circulation patterns that facilitate build-up of intenseblooms during late summer. Offshore dinoflagellate populations are advected shorewards and polewards in response to relaxation of upwelling at the Namaqua cell to the north. Dinoflagellate blooms are advected south from the southern Namaqua shelf during upwelling relaxation. Under such conditions, the gyre south of Elands Bay moves offshore and a barotropic flow past Cape Columbine is established. Evidence suggests that the nearsurface component of the flow occurs as a sudden “flood” event. These dinoflagellate-containing shelf waters are in turn advected into Saldanha Bay when upwelling relaxes, when the density gradient between the bay and the shelf drives surface inflow and bottom water outflow. These flows are reversed with the resumption of upwellingover the shelf, resulting in intrusion and entrainment of bottom water and surface outflow. Entrainment dictates that the bay acts as a net importer of bottom water and net exporter of surface waters over a synoptic cycle. Thissystem of exchange between Saldanha Bay and the shelf curtails the duration and severity of toxic episodes in the bay relative to the shelf
Caracterização de matrizes de Quitosano para a regeneração de tecidos produzidas pela técnica de TIPS
Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia BiomédicaEntre as principais aplicações biomédicas do quitosano (CS), encontra-se a produção de matrizes para Engenharia de Tecidos (ET). Este polissacarídeo apresenta diversas características de interesse, tais como a actividade antimicrobiana e a capacidade de cicatrização de lesões provenientes de agressões, como por exemplo, ferimentos ou queimaduras. Além disso, o CS estimula a proliferação celular, é biodegradável, biocompatível e confere excelente resistência mecânica aos biomateriais em si baseados. Neste trabalho foram produzidos e caracterizados hidrogéis, pensos curativos coagulados e não coagulados e matrizes 3D para a ET, produzidos a partir de soluções de CS. Foram estudados diferentes parâmetros da produção de hidrogéis: o tempo de exposição necessária para a sua coagulação dentro de uma câmara de amónia e o seu comportamento quando colocados em soluções aquosas de diferente pH. Diferentes matrizes foram produzidas pela técnica de TIPS, a saber: pensos curativos (coagulados e não coagulados) e matrizes 3D para a ET. As condições de liofilização foram optimizadas para cada um destes materiais, tendo-se verificado que é possível obter materiais com elevada anisotropia. As características físico-químicas e mecânicas destes materiais dependem das soluções precursoras, bem como do processamento. Todos os materiais foram testados à citotoxicidade e os pensos curativos não coagulados foram usados para testes “in vivo”, tendo-se verificado que este promove a cicatrização de feridas. O presente trabalho representa, assim, uma contribuição para o desenvolvimento dos nossos materiais à base de CS, para aplicações médicas
Otimização de parâmetros de lubrificação e velocidade em SPIF
With the rising competitiveness in industry, it is mandatory to develop new methods and processes in order to fill some gaps, and at the same time ameliorate the existing ones. Incremental forming appears from the necessity to produce functional and usable prototypes, or alternatively, to produce small batches or replacement parts. In fact, the traditional use of press technology represents a very high cost when the number of parts in a batch is not big enough. Within incremental forming, the cost of tools is reduced to a minimum as just a punch and a clamping frame are needed to produce a part from the CAD model, which brings high interest to this technology.
This work is part of the SPIF-A project (Single Point Incremental Forming at Aveiro). From many possible parameters, focus will be given to lubrication and federate (the travel speed of the forming tool). These two parameters are utmost importance either for the quality of parts and for the process time efficiency.
After experimental tests, results will allow for conclusions that will certainly constitute a vital contribute for a better implementation of incremental forming processes into industrial environment.Com a constante competitividade da indústria, existe a necessidade de criar novos métodos e processos que colmatem lacunas dos já existentes, assim como procurar soluções com rendimentos superiores, tanto quantitativamente como qualitativamente. A estampagem incremental surge aliada à dificuldade de produção de protótipos funcionais e reais. A necessidade de produção de pequenos lotes de peças a um custo competitivo é outro fator preponderante para a evolução deste tipo de tecnologia, visto que os métodos de estampagem tradicionais implicam custos muito elevados para a conceção das ferramentas necessárias. Esta tecnologia permite à indústria produzir uma grande variedade de produtos com custos reduzidos e numa janela de tempo bastante mais curta que a generalidade dos processos convencionais, o que torna a estampagem convencional numa tecnologia muito flexível proporcionando à industria uma vertente bastante interessante trazendo novas soluções para os vários tipos de mercado.
Neste trabalho, inserido no projeto SPIF-A (Single Point Incremental Forming at Aveiro) são estudados com recurso a testes experimentais, duas classes de parâmetros importantes quer para a qualidade, quer para o rendimento do processo: i) o efeito dos lubrificantes na qualidade superficial dos componentes produzidos e forças geradas durante a conformação e ii) o efeito do aumento da velocidade do punção conformador nas forças geradas e formabilidade das peças produzidas.
Face ao conhecimento gerado, considera-se que esta tese teve um contributo importante do desenvolvimento do processo de estampagem incremental com vista à sua melhor implementação industrial.CENTRO-01-0145-FEDER-022083Mestrado em Engenharia Mecânic
Os projectos organizacionais da economia social no contexto da crise atual
A presente investigação tem como objetivo aferir e analisar o impacto da crise atual nas organizações da Economia Social, com especial atenção aos financiamentos e aos projetos.
Neste sentido, a investigação incide, numa primeira fase, na compreensão do surgimento da crise atual e o modo como esta se estendeu à Europa. De seguida, contextualiza-se o impacto da crise na Europa, bem como o modo como o mesmo foi agravado por problemas com a dívida soberana.
O impacto da crise conduziu o Estado Português à necessidade de recorrer a ajuda externa, o que em contrapartida implicou a adoção de medidas de austeridade que incluem uma reestruturação e redução da despesa pública. Inevitavelmente, estas medidas originaram um impacto negativo na economia e nos seus atores, atingindo também direta e indiretamente a Economia Social.
A fim de aferir o impacto da crise atual nas organizações da Economia Social foi aplicado um inquérito por questionário. A amostra do estudo foi constituída por 186 organizações de todo o país e com distintas formas jurídicas. Tendo como base a metodologia quantitativa, realizou-se uma análise estatística descritiva e aplicados testes paramétricos e não paramétricos.
Os resultados obtidos confirmam a hipótese de que a crise atual tem um impacto nas organizações da Economia Social, nomeadamente ao nível da redução dos fincamentos e número de projetos executados. Em sentido inverso, o número de clientes/utentes manteve-se ou aumentou, facto que aponta para a importância e situação paradoxal da Economia Social na atual conjuntura.This research aims to assess and analyze the impact of the current crisis on Social Economy organizations, with special regard to funding and projects.
The research thus focuses initially on understanding the emergence of the current crisis and how it has affected Europe. It then contextualizes the impact of the crisis in Europe and its relation to sovereign debt.
The impact of the crisis constrained the Portuguese State to seek assistance abroad, which in turn led to the adoption of austerity measures such as restructuring and cutting public expenses. Inevitably these measures have resulted in a negative impact on the economy and its actors, affecting directly and indirectly the Social Economy.
In order to measure the impact of the current crisis on Social Economy organizations, a questionnaire was developed and applied to a sample consisting of 186 organizations from across the country and with including different legal forms. Based on the quantitative methodology, we carried out a descriptive statistical analysis and applied parametric and nonparametric tests.
The results confirm the hypothesis that the current crisis has an impact on the Social Economy organizations, particularly in terms of reducing financial resources and the number of projects executed. Conversely the number of clients / users remained stable or increased, thus indicating the importance and the paradoxical situation of the Social Economy in the current conjuncture
Translation and validation of Hyperhidrosis Disease Severity Scale
Introduction: The evaluation of patients with hyperhidrosis (HH) can be accomplished, among other ways, through questionnaires and scales. The Hyperhidrosis Disease Severity Scale (HDSS) has been used as a simple and quick tool to perform this evaluation. Although HDSS has been well established in several languages, it has not been translated into Portuguese, restricting its specific use for Brazilian patients. The aim of this study was to translate HDSS into Portuguese and validate it in a sample of Brazilian subjects.
Method: 290 Brazilian patients (69% women, with a mean age of 28.7±9.6 years and BMI 22.4±3.9 kg/m2) diagnosed with HH were evaluated using HDSS, Quality of Life Questionnaire (QLQ) and Sweating Evolution Questionnaire (SEQ) before and after a five-week oxybutynin treatment. Regarding validation, an association between HDSS results and two other questionnaires was performed. To analyze HDSS sensitivity, evaluation of effects pre- and post-treatment with oxybutynin was conducted. Furthermore, HDSS reproducibility was analyzed in a subsample in which the scale was applied again after 7 days of the first follow-up appointment.
Results: There was statistical correlation between HDSS and QLQ and between HDSS and SEQ before treatment and after 5 weeks. Additionally, HDSS was reproducible and sensitive to clinical changes after the treatment period.
Conclusion: The Portuguese version of HDSS has been validated and shown to be reproducible in a Brazilian sample. Therefore it can be used as a tool to improve medical assistance in patients with HH
Ultrafine grained titanium for biomedical applications: An overview of performance
AbstractUltrafine grain sized titanium (UFG Ti) obtained by severe plastic deformation presents a bright potential for biomedical applications because it provides the strength of titanium alloys without toxic alloying elements, such as Al and V that, by dissolving away from the implant, may be harmful to human health. The most recent developments and challenges in this field are reviewed. UFG Ti mini-devices were implanted in rabbits and the removal torque was compared with that of conventional commercially pure (cp) grain sized Ti Grade 2 and Ti6Al4V alloy Grade 5. The osseointegration of the UFG Ti was slightly superior of that of cp Ti Grade 2. The microstructure and mechanical properties of the UFG Ti, with special emphasis on dental implant application are reviewed and some additional properties evaluated and presented
Determinación de los coeficientes de arrastre y sustentación en un perfil angular de alas iguales con el empleo de simulación numérica
Telecommunications towers and other structures composed of steel sections are particularly susceptible to the action of wind loads that need to be quantified for a correct design of these sections. In the obtaining of wind loads, the determination of the drag (CD) and lift (CL) coefficients of the elements that compose the lattice, is vitally important because, from these coefficients, the separation and the permeability of the lattice is estimated the acting wind load. This paper studies the influence of the blockage ratio on the CD and CL coefficients in an equal-leg angle section, widely used in this kind of structure. To obtain these coefficients, computational fluid dynamics (CFD) was used through OpenFOAM software. As part of the experiment, three blockage ratios were simulated: 5 %, 10 % and 20%, using as a comparison pattern the CD and CL values provided by the NBR 6123 1988, NC 285 2003, NBCC 2005 and ASCE 7-10 2010 standards [1]-[4] . The best results were obtained for a 5 % blockage.Torres de telecomunicaciones y otras estructuras compuestas por perfiles metálicos resultan particularmente susceptibles a la acción de las cargas de viento, las cuales deben cuantificarse para un correcto dimensionamiento de estos perfiles. En la obtención de la carga ecológica de viento, la determinación de los coeficientes de arrastre (CD) y la sustentación (CL) de los elementos que componen el reticulado reviste vital importancia debido a que, a partir de estos coeficientes, la separación entre los reticulados y su permeabilidad, se estima la carga de viento actuante. Este trabajo estudia la influencia de la relación de bloqueo en los coeficientes CD y CL en un perfil angular de alas iguales, muy utilizado en este tipo de estructuras. A fin de obtener estos coeficientes se empleó la dinámica de fluidos computacional (CFD por su sigla en inglés) a través del software OpenFOAM. Como parte del experimento se simularon tres relaciones de bloqueo: 5 %, 10 % y 20 %, al emplear como patrón de comparación los coeficientes brindados por las normativas NBR 6123 1988, NC 285 2003, NBCC 2005 y ASCE 7-10 2010 [1]-[4]. Los mejores resultados de la comparación efectuada entre el experimento numérico y los valores normados se obtuvieron para un 5 % de bloqueo
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