1,627 research outputs found

    Correlation equalities and upper bounds for the transverse Ising model

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    Starting from an exact formal identity for the two-state transverse Ising model and using correlation inequalities rigorous upper bounds for the critical temperature and the critical transverse field are obtained which improve effective results.Comment: 8 pages, 1 figur

    Alfalfa Response to Phosphorus Sources Associated with the Application of Liming and Gypsum-Shoot Numbers

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    Alfalfa (Medicago sativa L.) was grown in a Typic Mapluolox soil with triple superphosphate (TS), Gafsa phosphate (GP) and GP with gypsum (GP + G). Three rates of phosphorus application were used 50, 100 and 200 mg P dm-3, before and after liming. Alfalfa was harvested three times. Basal and axillary shoot numbers in alfalfa increased with increasing phosphorus rates. Shoots were produced in higher number with GP in comparison with TS. GP + G resulted in higher basal shoot number than GP. However, there was no gypsum effect on axillary shoot numbers. Liming before or after TS, GP and GP + G application had similar responses on shoot numbers

    Commentary: Human liver Flukes

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    Insights about destination brand: Madeira case study

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    The concept of brand as known today is passed through various (re) definitions over the years. Initially, the brand was associated with house products, but with the evolution of society has come to represent industrial products, people, values, and services. Nowadays due to the great offer of tourist destinations, brands also represent countries, cities, and regions. This type of brands, result from maturation and of the coverage of the functionality of the same. Thus, the tourist brands or place brands, come from the necessity to value the places through its unique characteristics, boosting the visit of tourists and the sustainability of the destination. The island of Madeira is a typical tourist destination, which stands out from the competition through its heritage, in terms of culture and patrimony. With its economy based on tourism and to measure the importance of the Brand, an interview was conducted at one of the main actors in this area, specifically the Regional Tourism Director of the Autonomous Region of Madeira. In addition we have interview 118 tourists during July and August 2017 at Madeira airport.info:eu-repo/semantics/publishedVersio

    The behavior of academic investigators using an institutional repository

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    Institutional repositories (IRs) are a new strategy for universities to expedite changes in scientific communication. They are digital collections that store, preserve, and make available the intellectual output of one or more universities. Housing this production in an IR can solve problems such as the high acquisition and maintenance costs of collections, and the publication of gray literature, reports and post-prints. However, the IR brings new questions about copyright that are still in discussion. It can also improve the situation of the universities that are responsible for producing 70% of the scientific papers, buying from commercial editors about 90% of the articles they consume, compromising part of the budget in the acquisition of periodicals that bring back the results of their own work. The use of open archives by IRs should stimulate self-archiving, since it assures a more efficient dissemination of digital documents. However, self-archiving is a new task, sometimes perceived as an additional burden in overcrowded schedules, not yet part of the habits and routines of researchers and academic staff. This work is justified in a socio-cultural context, especially in understanding the behavior of investigators from different knowledge areas and cultures in their acceptance and use of IRs, being possible to know important factors in its adoption. This way, we intend to provide the academic managers guidelines that help them to promote a culture of sharing and disseminating the scientific information produced by their institutions, increasing the investigation’s excellence

    A crise social desenhada pelas crianças: imaginação e conhecimento social

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    A crise social e económica que tem atingido o mundo desde 2008, com efeitos especialmente sentidos nos países do Sul da Europa, causou impactos fortes e visíveis na infância, como o aumento das taxas efetivas e de risco de pobreza e a vulnerabilidade e a exposição a fatores de risco social e de perda consistente de direitos. A análise dessas incidências tem vindo a ser trabalhada num conjunto de relatórios nacionais e internacionais, de ONG’s e estudos académicos. No entanto, poucos estudos têm dedicado atenção ao modo como a interpretação das representações das crianças sobre a crise é feita e sobre as expressões específicas que estas assumem na sua vida quotidiana. As crianças são capazes de observar os modos como a crise impacta o seu próprio grupo geracional, bem como os adultos que mais lhe são próximos. Da mesma forma, promovem interpretações económicas sobre os fenómenos, sejam elas mais “ingénuas” ou mais complexas. Este artigo incide sobre as representações das crianças sobre a crise social e económica em Portugal. São especialmente analisadas narrativas gráficas produzidas por crianças oriundas de classes trabalhadoras, com idades compreendidas entre os 6 e os 10 anos de idade. Por meio dessas narrativas, as crianças constroem formas visuais a partir da sua imaginação sobre a sua condição. Assim, a imaginação das crianças é um modo de acesso ao conhecimento na sociedade onde se inserem e aos seus modos próprios de compreensão de realidades complexas.The social and economic crisis that has hit the world since 2008, with effects strongly felt in the countries of Southern Europe, has had fierce and visible impacts in childhood with the increase of the effective rates, the risk of poverty and vulnerability, and the exposure to factors of social risk and consistent loss of rights. The analysis of these incidents has been worked on in a series of national and international reports from NGOs and academic studies. However, few studies have devoted attention to the way in which the interpretation of the representations of children about the crisis is made and the specific expressions that they assume in their daily lives. Children are able to observe the ways in which the crisis affects their own generational group as well as the adults closest to them. In the same way, they promote economic interpretations of phenomena, whether “naïve” or more complex. This article focuses on the representations of children about the social and economic crisis in Portugal. Graphical narratives produced by children from working classes, aged between 6 and 10 years old, are given focus. From these narratives, children construct visual forms from their imagination about their social condition. Thus, the child’s imagination is a way of accessing knowledge in the society they belong to and their own way of understanding complex realities.CIEC - Centro de Investigação em Estudos da Criança, IE, UMinho (UI 317 da FCT), Portugalinfo:eu-repo/semantics/publishedVersio

    Tensión de adhesión de revestimientos cerámicos obtenidos por proyección robótica a llama

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    Introduction: One of the possible applications of ceramic thermal barriers is in shells (permanent moulds – die casting). The moulds` capacity to support very high temperatures (up to 1600 °C) plays a crucial role in the selection of materials due to the liquid state of the cast iron. Objectives: This paper presents and discusses the obtained results from robotic flame projection tests, carried out with the purpose to quantify the influence of several factors of flame sprayed in the adhesion strength of coatings of Nickel-Aluminium Molybdenum and Zirconium Oxide. In literature a minimum adhesion strength was not found for the application of thermal ceramic barriers in the coating of permanent casting moulds, so in this work it is intended to obtain its values considering several combinations of projection parameters and substrates. Methods: The determination of the adhesion strength was performed according to the standard ASTM C633-79 where the coated test specimens were glued to CK45 steel against-specimens with a cyanoacrylate glue (LOCTITE 415). A weight of 100 N was then applied for 3 minutes to promote the initiation of the polymerization reaction of the cyanoacrylates and a period of 24 hours was needed so the bonded glue could acquire its maximum strength (sufficient enough to tear off the coating of the specimen). Finally tensile tests were carried out at the speed of 1 mm/min. Results: The main parameters studied are the material of the substrate, the projection angle and the substrate preheating temperature. The higher adhesion strength for the sprayed to 90° (average value of 6.2 MPa) was obtained by the specimens of spheroidal graphite cast iron (SGCI) with a preheating temperature of 120 °C. For the preheating of 90 °C and spray angle of 90° the aluminum-copper (AlCu) and brass specimens were the ones that obtained the higher adhesion strengths (average value of 4.5 MPa). The sprayed of 65° originates the higher adhesion strength in all the materials used for the substrate, being the highest value (average value of 8.3 MPa) obtained by the spheroidal graphite cast iron. Conclusions: The results obtained clearly suggest that the substrate material and the preheating temperature strongly influence the adhesion strength. The analysis of the coatings microstructures, using optical microscopy, supports this observation.Introdução: Uma das possíveis aplicações de barreiras térmicas cerâmicas é no revestimento de moldes permanentes para fundição. A capacidade do molde suportar temperaturas muito elevadas (até 1600 °C), devido ao estado líquido do ferro fundido, desempenha um papel crucial na seleção de materiais. Objetivos: Este artigo apresenta e discute os resultados obtidos a partir de testes de projeção robótica à chama, com o objetivo de quantificar a influência de vários fatores da projeção à chama na tensão de adesão de revestimentos de Níquel-Alumínio Molibdênio e Óxido de Zircónia. Na literatura não foi encontrada uma tensão mínima de adesão requerida para a aplicação de barreiras térmicas cerâmicas no revestimento de moldes permanentes para fundição, assim, no trabalho apresentado neste artigo, pretende-se obter seus valores considerando várias combinações de parâmetros de projeção e substratos. Métodos: A determinação da tensão de adesão foi realizada de acordo com a norma ASTM C633-79 em que os provetes revestidos foram colados a contra-provetes de aço CK45 grenalhados, com uma cola à base de cianoacrilatos (LOCTITE 415). De seguida aplicou-se um peso de 100 N durante 3 minutos para a força de compressão promover o início da reação de polimerização dos cianoacrilatos e aguardou-se 24 horas para que a junta colada tivesse tempo de adquirir a resistência máxima (o suficiente para arrancar o revestimento do provete). Realizaram-se depois ensaios de tração à velocidade de 1 mm/min. Resultados: Os principais parâmetros estudados foram o material do substrato, o ângulo de projeção e a temperatura de pré aquecimento do substrato. A maior força de adesão para a projeção a 90° (média de 6,2 MPa) foi obtida com os provetes de ferro fundido com grafite esferoidal (SGCI) com uma temperatura de pré-aquecimento de 120 ° C. Para o pré-aquecimento de 90 °C e ângulo de projeção de 90°, foram os provetes de duralumínio (AlCu) e de latão que obtiveram as maiores forças de adesão (média de 4,5 MPa). A projeção a 65 ° origina a maior tensão de adesão em todos os materiais utilizados para o substrato, sendo o maior valor (média de 8,3 MPa) obtido pelo ferro fundido de grafite esferoidal. Conclusões: Os resultados obtidos sugerem claramente que o material do substrato e a temperatura de pré-aquecimento influenciam fortemente a tensão de adesão. A análise das microestruturas dos revestimentos, utilizando microscopia ótica, comprova esta observação.Introducción: Una de las posibles aplicaciones de barreras térmicas cerámicas es en el revestimiento de moldes permanentes para fundición. La capacidad del molde para soportar temperaturas muy altas (hasta 1600 °C), debido al estado líquido del hierro fundido, desempeña un papel crucial en la selección de materiales. Objetivos: Este artículo presenta y discute los resultados obtenidos a partir de pruebas de proyección robótica a la llama, con el objetivo de cuantificar la influencia de varios factores de la proyección a la llama en la resistencia a la adhesión de revestimientos de Niquel-Aluminio-Molibdeno y Óxido de Zirconia. En la literatura no se encontró una tensión mínima de adhesión requerida para la aplicación de barreras térmicas cerámicas en el revestimiento de moldes permanentes para fundición, así en el trabajo presentado en este artículo, se pretende obtener sus valores considerando varias combinaciones de parámetros de proyección y sustratos. Métodos: La determinación de la tensión de adhesión se realizó de acuerdo con la norma ASTM C633-79 en la que se probaron las probetas revestidas a contra-probetas de acero CK45 gralladas, con un pegamento a base de cianoacrilatos (LOCTITE 415). A continuación se aplicó un peso de 100 N durante 3 minutos para la fuerza de compresión promover el inicio de la reacción de polimerización de los cianoacrilatos y se aguardó 24 horas, para que la junta adhesiva tuviera tiempo de adquirir la resistencia máxima (suficiente para arrancar el revestimiento de la probeta). Se realizaron después los ensayos de tracción a velocidad de 1 mm/min. Resultados: Los principales parámetros estudiados son el material del sustrato, el ángulo de proyección y la temperatura de precalentamiento del sustrato. La mayor fuerza de adhesión para la proyección a 90° (media de 6,2 MPa) fue obtenida con las probetas de hierro fundido con grafito esferoidal (SGCI) con una temperatura de precalentamiento de 120 °C. Para el precalentamiento de 90 °C y ángulo de proyección de 90°, fueron las probetas de duraluminio (AlCu) y de latón que obtuvieron las mayores fuerzas de adhesión (media de 4,5 MPa). La proyección a 65° origina la mayor tensión de adhesión en todos los materiales utilizados para el sustrato, siendo el mayor valor (media de 8,3 MPa) obtenido por el hierro fundido de grafito esferoidal. Conclusiones: Los resultados obtenidos sugieren claramente que el material del sustrato y la temperatura de precalentamiento influyen fuertemente en la fuerza de adhesión. El análisis de las microestructuras de los revestimientos, utilizando microscopia óptica, comprueba esta observación

    Epstein-Barr virus encephalitis presenting with brain mass lesions in a patient with human immunodeficiency virus infection

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    Epstein-Barr virus (EBV) disease of central nervous system (CNS) in human immunodeficiency virus (HIV) patients is mostly associated with primary CNS lymphoma (PCNSL). In patients who cannot undergo biopsy and have typical clinical and radiographic findings, detection of EBV deoxyribonucleic acid in CSF may provide enough evidence to start treatment for PCNSL. Here, we described a case of EBV encephalitis presenting with fever, memory, and psycho-motor deficits in a patient with HIV infection and severe immunosuppression who started antiretroviral therapy (ART) one month earlier. Brain magnetic resonance imaging showed periventricular lesions with nodular enhancing pattern and restricted diffusion, and CSF was positive for EBV. Brain biopsy revealed inflammatory lesions and lymphoid infiltrate without signs of malignancy. After three months of ART, patient improved significantly and MRI showed a marked reduction of lesions. Two years later, patient’s condition remains stable. PCNSL is the leading diagnosis in HIV patients with CNS mass lesions and positive CSF for EBV. In the case described, starting treatment for PCNSL could have been considered if the patient could not undergo biopsy, or if there was no improvement under ART. However, EBV encephalitis can be a differential diagnosis in patients with compatible histopathology and clinical course. © 2023 Termedia Publishing House Ltd.. All rights reserved

    Endemicity Analysis of the Ichtyofauna of the Rio Doce Basin, Southeastern Brazil

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    The Rio Doce is a very important freshwater system in Brazil running through the Atlantic Forest, however available information about its biodiversity is scarce. In 2015, the Rio Doce basin was damaged by a burst of Fundão tailing dam in Mariana (Minas Gerais) causing an extraordinary environmental damage, with consequences still incompletely known. In the present paper we analyzed 6042 latitude/longitude records of 208 fish species from the Rio Doce deposited in collections prior to November 2015, in order to identify areas of endemism in the river before the burst. Several areas of endemism were identified along the basin, most of them describing small and novel patterns. Our analyses helped to identify areas of major diversity along the basin as well as information gaps concerning fish sampling. We hope this contribution will help obtaining quantitative measures on the impact caused by the Fundão dam catastrophe on fish biodiversity and will be useful to orient general actions towards the restoration of the basin.Fil: Sarmento Soares, Luisa M.. Universidade Estadual de Feira de Santana; Brasil. Universidade Federal do Espírito Santo; Brasil. Instituto Nossos Riachos; BrasilFil: Martins Pinheiro, Ronaldo F.. Instituto Nossos Riachos; BrasilFil: Casagranda, Maria Dolores. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentin
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