1,810 research outputs found

    MASS TRANSFER CORRELATION FOR THE REMOVAL OF COPPER IONS FROM WASTEWATER

    Get PDF
    One of the biggest problems with ore processing in extractive metallurgical industries is the high toxicity of the heavy metals waste content (e.g., copper, lead, nickel and chrome). This work investigates the copper (II) íons removal from aqueous solutions in concentrations up to 1000 ppm. Therefore, a fluidized bed electrolytic reactor was used with flow-by configuration considered as a hopeful method due to the large specific surface area and the high mass transfer rate. The performance of the electrochemical reactor was investigated by using different porosities. Dimensionless Sherwood and Reynolds numbers were correlated to characterize the mass transport properties of the reactor, and they were fitted to the equation Sh = a.Reb.Sc1/3

    Catatonia em Encefalite Anti-Receptor N-Metil-D-Aspartato (NMDA) Confundida com Esquizofrenia

    Get PDF
    Anti-N-Mmethyl-D-aspartate receptor encephalitis is an autoimmune disease of the central nervous system with prominent neurologic and psychiatric features. Symptoms appear progressively and sometimes with an exclusively psychiatric initial presentation. The patient's evaluation should be meticulous, and we should use all the diagnostic tests required for the exclusion of entities that can mimic this disease. We report the diagnostic investigation of a case of anti-N-methyl-D-aspartate receptor encephalitis in a patient with a previous diagnosis of schizophrenia with poor response to antipsychotics. The aim of this case report is to highlight the importance of close surveillance for neuropsychiatric symptoms, especially catatonia, and to recognize autoimmune encephalitis in the differential diagnosis of psychotic disorders with neurological symptoms and resistance or intolerance to antipsychotics. A prompt diagnosis will contribute to a faster onset of therapy and an overall improvement in prognosis.info:eu-repo/semantics/publishedVersio

    Modeling Heterogeneous Materials via Two-Point Correlation Functions: I. Basic Principles

    Full text link
    Heterogeneous materials abound in nature and man-made situations. Examples include porous media, biological materials, and composite materials. Diverse and interesting properties exhibited by these materials result from their complex microstructures, which also make it difficult to model the materials. In this first part of a series of two papers, we collect the known necessary conditions on the standard two-point correlation function S2(r) and formulate a new conjecture. In particular, we argue that given a complete two-point correlation function space, S2(r) of any statistically homogeneous material can be expressed through a map on a selected set of bases of the function space. We provide new examples of realizable two-point correlation functions and suggest a set of analytical basis functions. Moreover, we devise an efficient and isotropy- preserving construction algorithm, namely, the Lattice-Point algorithm to generate realizations of materials from their two- point correlation functions based on the Yeong-Torquato technique. Subsequent analysis can be performed on the generated images to obtain desired macroscopic properties. These developments are integrated here into a general scheme that enables one to model and categorize heterogeneous materials via two-point correlation functions.Comment: 37 pages, 26 figure

    Intraepidermal Epidermotropic Metastatic Melanoma: a Clinical and Histopathological Mimicker of Melanoma in Situ Occurring in Multiplicity

    Get PDF
    The distinction between primary melanoma and melanoma metastatic to the skin has major prognostic implications. We report a case of a 67-year-old male with a diagnosis of a superficial spreading melanoma (stage IB) rendered 6 years earlier who presented clinically with an atypical nevus on his left thigh. Histopathological examination showed an intraepidermal melanocytic proliferation that was interpreted as melanoma in situ. Subsequently, 45 additional pigmented macules appeared in crops over a 9-month period. Clinically and dermoscopically, these lesions were extremely polymorphic. Histopathological findings were compatible with melanoma in situ, as each lesion consisted of a wholly intraepidermal proliferation of markedly atypical melanocytes arranged singly and in nests. A complete gastrointestinal study showed multiple pigmented metastatic lesions throughout the stomach and small bowel, which supported a diagnosis of metastatic melanoma with gastrointestinal and epidermotropic skin involvement. Monosomy of chromosome 9 and a BRAF V600E mutation were detected in the primary tumor sample and in macro-dissected secondary lesions. No CDKN2A or CDK4 germline mutations were found. Intraepidermal epidermotropic metastases of melanoma have been rarely described in literature. In this case, histopathology alone was insufficient to distinguish metastatic melanoma from multiple in situ melanomas. The recognition of epidermotropic metastases should be based on the correlation between clinical, dermoscopic, histopathological and molecular findings

    Integration of Dirac-Jacobi structures

    Full text link
    We study precontact groupoids whose infinitesimal counterparts are Dirac-Jacobi structures. These geometric objects generalize contact groupoids. We also explain the relationship between precontact groupoids and homogeneous presymplectic groupoids. Finally, we present some examples of precontact groupoids.Comment: 10 pages. Brief changes in the introduction. References update

    Detecção de Cucumber mosaic virus em alface no estado do Pará.

    Get PDF
    A alface (Lactuca sativa L.) é uma planta anual, originária de clima temperado, pertencente à família Asteracea, e certamente uma das hortaliças mais populares e consumidas no Brasil e no mundo. Diversas viroses podem causar danos à cultura da alface. O objetivo deste trabalho foi detectar a presença do Cucumber mosaic virus (CMV) na cultura da alface, utilizando o teste RT-PCR. Foram coletadas 50 amostras de alface aparentemente sem sintomas característicos de viroses no município de Ananindeua-PA e na horta da UFRA campus Belém-PA. O ácido nucléico total foi extraído a partir de folhas de alface. Para a detecção do CMV por meio do RT-PCR utilizou-se um par de iniciadores denominados CMV-CPR e CMV-CPF que permitem a amplificação do fragmento de cerca de 700 pb do DNA do gene da capa proteica. O CMV foi detectado em três amostras analisadas. Este foi o primeiro relato de CMV em alface no estado do Pará

    Path Integral Approach to Strongly Nonlinear Composite

    Full text link
    We study strongly nonlinear disordered media using a functional method. We solve exactly the problem of a nonlinear impurity in a linear host and we obtain a Bruggeman-like formula for the effective nonlinear susceptibility. This formula reduces to the usual Bruggeman effective medium approximation in the linear case and has the following features: (i) It reproduces the weak contrast expansion to the second order and (ii) the effective medium exponent near the percolation threshold are s=1s=1, t=1+κt=1+\kappa, where κ\kappa is the nonlinearity exponent. Finally, we give analytical expressions for previously numerically calculated quantities.Comment: 4 pages, 1 figure, to appear in Phys. Rev.

    Electromagnetically induced transparency and dynamic Stark effect in coupled quantum resonators

    Full text link
    In this work we reproduce the phenomenology of the electromagnetically induced transparency and dynamic Stark effect in a dissipative system composed by two coupled bosonic fields under linear and nonlinear amplification process. Such a system can be used as a quantum switch in networks of oscillators
    corecore