Magnetic And Magnetocaloric Properties On The U1-y Ry Ga2 (r=er And Dy) Compound

The magnetic, calorimetric, and magnetocaloric properties of the pseudobinary U1-y Ry Ga2 (R=Er and Dy) series were studied to determine its potential as a candidate for use in cryogenic magnetic refrigeration. The partial substitution of Dy and Er for U provides a wide range of the ordering temperature and increases the saturation magnetic moment. The results for U1-y Dyy Ga2 with 0.6<y<0.9 show evidences of a spin-glass-like (SG) behavior, possibly as a consequence of competing anisotropy and exchange interactions within a frustrated hexagonal spin lattice. The isothermal magnetic entropy change (Δ Smag) observed for U Ga2 shows a well defined peak centered on TC, which is gradually broadened and shifted to lower temperatures as the Er and Dy content increases. For low concentrations (0.2≤y≤0.4) a tablelike profile is observed in the Δ Smag curve. © 2008 American Institute of Physics.1037Gschneidner Jr., K.A., Pecharsky, V.K., Tsokol, A.O., (2005) Radiat. Prot. Dosim., 68, p. 1479Bruck, E., (2005) J. Phys. D, 38, p. 381Yu, B.F., Gao, Q., Zhang, B., Meng, X.Z., Chen, Z., (2003) Int. J. Refrig., 26, p. 622Gschneidner Jr., K.A., Pecharsky, A.O., Pecharsky, V.K., (2001), 11, p. 433. , Cryoolers (Academic-Plenum, New York), Vol.,Smaili, A., Chahine, R., (1996) Adv. Cryog. Eng., 42, p. 445Hashimoto, T., Kuzuhura, T., Sahashi, M., Inomata, K., Tomokiyo, A., Yayama, H., (1987) J. Appl. Phys., 62, p. 3873Lima, A.L., Gschneidner Jr., K.A., Pecharsky, V.K., Pecharsky, A.O., (2003) Phys. Rev. B, 68, p. 134409De Oliveira, N.A., Von Ranke, P.J., (2003) J. Magn. Magn. Mater., 264, p. 55Tsai, T.H., Sellmyer, D.J., (1979) Phys. Rev. B, 20, p. 4577Doukouŕ, M., Gignoux, D., (1982) J. Magn. Magn. Mater., 30, p. 111Gignoux, D., Schimitt, D., Takeuchi, A., Zhang, F.Y., (1991) J. Magn. Magn. Mater., 97, p. 15Andreev, A.V., Belov, K.P., Deryagin, A.V., Levitin, R.Z., Menovsky, M., (1979) J. Phys. Colloq., 4, p. 82Mydosh, J.A., (1993), Spin Glasses: An Experimental Introduction (Taylor&Francis, London)Markin, P.E., Baranov, N.V., Sinitsyn, E.V., (1991) Physica B, 168, p. 19

Crystallographic texture evolution in Ti–35Nb alloy deformed by cold rolling

This work presents the results of a microstructural characterization of the Ti–35Nb alloy deformed by cold rolling. Initially, samples of the Ti–35Nb (wt%) alloy were obtained by electric arc melting. After melting, these samples were solution heat-treated at 1000 °C for 8 h and water quenched. The resulting microstructure was composed of β-phase (bcc) combined with orthorhombic martensite (α″). Samples were cold-rolled in multiple passes to reduce their thickness by up to 85% without intermediary annealing. They were then characterized by light optical microscopy, X-ray diffraction and Vickers hardness measurements. Young’s modulus was determined by ultrasonic methods and nanoindentation measurements. The texture evolution and orientation relationship between phases were studied by X-ray diffraction and electron backscatter diffraction (EBSD). The results reveal the presence of shear bands in the deformed samples, an orientation of the orthorhombic martensite phase in relation to the rolling direction, and variations of Young’s modulus in response to deformation. The textural results of the β-phase show a typical bcc rolling texture with strong (1 1 0) fiber and weak (1 1 1) fiber. The intensity of the (1 1 0) fiber increases with deformation60653660CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPNão temNão temNão temThe authors gratefully acknowledge the Brazilian research funding agencies FAPESP (State of São Paulo Research Foundation), CNPq (National Council for Scientific and Technological Development) and CAPES (Federal Agency for the support and Evaluation of Graduate Education) for their financial support of this wor

Relato de Pesquisa: Projeto Ciência e Performance, estudo da Conferência Internacional sobre Comunicação Pública da Ciência e Tecnologia

 O presente artigo está relacionado ao Projeto de Pesquisa “Ciência e Performance: estudo da Conferência Internacional sobre Comunicação Pública da Ciência e Tecnologia”. Apresentamos aqui os resultados parciais de um questionário disponibilizado no dia 13 de maio de 2014, logo após a Conferência na Bahia-Brasil, numa lista de discussão da Network for the Public Communication of Science and Technology (PCST). O questionário obteve 42 respostas de pesquisadores de diferentes países, com predominância do Brasil, Índia, Estados Unidos e Itália, seguidos da Austrália e da Inglaterra. INFORME DE INVESTI GACION : PROYE CTO DE INVESTI GACIÓN “CIEN CIA Y PERFOR MAN CE: ESTU DIO DE LA CONFEREN CIA INTERNA CIO NAL SOBRE COMUNI CACIÓN PÚBLI CA DE LA CIEN CIA Y LA TE CNO LO GÍA ”Resumen: El presente artículo está relacionado con el Proyecto de Investigación “Ciencia y Performance: estudio de la Conferencia Internacional sobre Comunicación Pública de la Ciencia y la Tecnología”. Presentamos aquí los resultados parciales de una encuesta realizada en el día 13 de mayo de 2014, poco después de la Conferencia en Bahía-Brasil, en una lista de discusión de la Network for the Public Communication of Science and Technology (PCST). El cuestionario obtuvo 42 respuestas de investigadores de diferentes países, con predominio de Brasil, India, Estados Unidos e Italia, seguidos de Australia e InglaterraRESEARCH RE PORT : RESEAR CH PRO JECT “SCIEN CE AN D PERFOR MAN CE: STU DY OF INTERNATIONAL INTERNATIONAL PUBLI C COMMUNI CATION ATION OF SCIEN CE AN D TE CHNOLO GY CONFEREN CE”ABSTRACT: The present work is a report Concerning the Research Project “Science and Performance: Study of International Public Communication of Science and Technology Conference”. We present here the partial results of a questionnaire made available on May 13, 2014, shortly after the Conference in Bahia, Brazil, in a mailing list of the Network for the Public Communication of Science and Technology. The survey received 42 responses from researchers of different countries, especially Brazil, India, United States and Italy, followed by Australia and England

Magnetization And Specific Heat In U 1-xla Xga 2 And Magnetocaloric Effect In Uga 2

We have investigated the properties of the ferromagnetic series U1-x Lax Ga2. The magnetization results show a reduction of μeff and of Tc when x is increased. The electronic coefficient γ of the specific heat increases to a maximum of 260 mJUmol K2 at x=0.75. This behavior is probably consequence of delocalization of 5f electrons, causing enhancement of the density of states. For x=0.9 the ordering disappears and a non-Fermi-liquid behavior is observed. U Ga2 also presented a significant magnetocaloric effect of Δ Smag =-3.5 Jkg K at 120 K and H=7 T which can be modified by chemical pressure. © 2005 American Institute of Physics.9710Andeev, A.V., Belov, K.P., Deriagin, A.V., Levitin, R.Z., Menovsky, A., (1979) J. Phys. Colloq., 4, p. 82Da Silva, L.M., Gandra, F.G., Rojas, D.P., Cardoso, L.P., Medina, A.N., (2002) Physica B, 312-313, p. 906Tran, V.H., Kaczorowski, D., Roisnel, T., Tróc, R., Noel, H., Bouŕe, F., Andŕ, G., (1995) Physica B, 205, p. 24Gandra, F.G., Rojas, D.P., Shlyk, L., Cardoso, L.P., Medina, A.N., (2001) J. Magn. Magn. Mater., 226, p. 1312Barbara, B., (1973) J. Phys. (Paris), 34, p. 1039Sechovsky, V., Havela, L., Svoboda, P., (1986) J. Less-Common Met., 121, p. 163Segal, E., Wallace, W.E., (1975) J. Solid State Chem., 13, p. 201Radwanski, R.J., Kim-Ngan, N.H., (1995) J. Magn. Magn. Mater., 140, p. 1373Zapf, V.S., Dickey, R.P., Freeman, E.J., Sirvent, C., Maple, M.B., (2002) Phys. Rev. B, 65, p. 024437Pecharsky, V.K., Gschneider Jr., K.A., (1997) Phys. Rev. Lett., 78, p. 4494Pecharsky, V.K., Gschneider Jr., K.A., (1997) Phys. Rev. Lett., 78, p. 4494Plackowski, T., Junod, A., Bouquet, F., Sheikin, I., Wang, Y., Jezÿowski, A., Mattenberger, K., (2003) Phys. Rev. B, 67, p. 184406Svobodaa, P., Sechovsky, V., Menovsky, A.A., (2003) Physica B, 339, p. 177Gama, S., Coelho, A.A., De Campos, A., Carvalho, A.M.G., Gandra, F.G., Von Ranke, P.J., De Oliveira, N.A., Phys. Rev. Lett

Fungal Infections in Neonatal Intensive Care

Neonates represent a unique and highly vulnerable patient population. Advances in medical technology have improved the survival and quality of life of newborns, particularly those with extreme prematurity or with congenital defects. Furthermore, immunologic immaturity and altered cutaneous barriers play some role in the vulnerability of neonates to nosocomial infections. In this context, the incidence of invasive fungal infections has increased significantly worldwide, representing an important infective complication in patients hospitalized in intensive care units. Invasive fungal infections in Neonatal Intensive Care Unit (NICUs) show high mortality; being species of Candida, the most isolates etiologic agents. The better prognosis of the patient is associated with the early diagnosis and fast treatment. However, guidelines to facilitate the optimal therapy choice for the treatment of neonatal fungal disease do not exist. The current antifungal agents that are available to treat fungemia among newborns and children are based on clinical trials in adults, since there are few comparative studies of antifungal agents in infants. The most commonly used drugs for the treatment of invasive fungal infections in neonates are classified in four different classes: polyene, azoles, analogs of pyrimidines and echinocandins

Modelos acoplados do IPCC-AR4 e o gradiente meridional de temperatua da superficie do mar no atlântico tropical : relaçoes com a precipitaçao no norte do nordeste do Brasil

Este artigo mostra como três modelos acoplados do Intergovernmental on Panel Climate Change - (IPCC-AR4), o FGOALS1. 0G &#8211; LASG do Institute of Atmospheric Physics of China, o GISSER da National Aeronautics Space Admnistration (NASA) e o GFDL_CM2 da National Oceanic and Atmospheric Administration (NOAA), simularam a variabilidade do gradiente meridional de Temperatura da Superfície do Mar (TSM), entre os meses de fevereiro a maio, no Atlântico Tropical (1901-1999). A precipitação durante a estação chuvosa (fevereiro a maio) no setor norte do Nordeste do Brasil (NEB) foi também analisada pelos três modelos e comparada com as observações. Os modelos GISSER e FGOALS1.0G mostraram melhor desempenho na simulação do sinal do gradiente meridional de TSM no Atlântico Tropical para o período de 1901 a 1999. Destaca-se que os modelos apresentaram um melhor desempenho na simulação da tendência decadal, conseguindo explicar entre 50% a 80% da variabilidade do gradiente, com a TSM do setor sul sendo mais bem simulada

Anticorpos líticos induzidos por infecção pelo Trypanosoma cruzi reconhecem epitopos presentes nas formas tripomastigotas e epimastigotas do parasita

Sera of Chaga's disease patients containing anti-T. cruzi lytic antibodies were submitted to affinity chromatography using Sepharose 4B conjugated with antigen extracted from epimasiigote or trypomasiigote forms of the parasite. Epimastigotes were obtained from culture at the exponential growth phase and the trypomastigotes from blood of infected and immunosuppressed mice. Antigen of both parasite forms was obtained by sonication of the parasites followed by centrifugation. Both antigens were then conjugated to activated Sepharose 4B. Affinity chromatography was performed by passing sera from chagasic patients through an immunoadsorbent column containing either epimasiigote or trypomasiigote antigens. Antibodies bound to the column were eluted with cold 0,2 M glycine buffer pH 2,8. The eluted antibodies were analysed regarding their isotype and lytic activity. The results showed that anti-T. cruzi lytic antibodies present in sera from chagasic patients are mainly located in the IgG isotype and recognize epitopes present in both trypomasiigote and epimastigote forms. A brief report of this work has already been published12.Soro de pacientes com doença de Chagas na fase crônica foram submetidos a cromatografia de afinidade com Sepharose 4B conjugada com um extrato antigênico obtido de formas epimastigotas ou tripomastigotas de T. cruzi: os epimastigotas foram obtidos de cultura na fase exponencial de crescimento e os tripomastigotas de sangue de camundongos infectados e imunossuprimidos. Os antígenos de ambas formas parasitárias foram obtidos por tratamento dos parasitas por ultra-som, seguido de centrifugação. A cromatografia de afinidade foi feita passando-se os soros chagásicos através de uma coluna de imunoadsorvente contendo antígenos de epimastigotas ou tripomastigotas. Os anticorpos foram eluídos da coluna com tampão glicina 0,2 M pH 2,8 a 4°C. Os anticorpos eluidos foram analisados quanto ao seu isotipo e atividade lítica. Os resultados mostraram que os anticorpos anti-T. cruzi com atividade lítica presentes em soros chagásicos estão localizados no isotipo IgG e reconhecem epitopos presentes tanto nos tripomastigotas quanto nos epimastigotas