1,214 research outputs found

    On the implicit immersed boundary method in coupled discrete element and lattice Boltzmann method

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    The coupled discrete element method and lattice Boltzmann method (DEMLBM) has increasingly drawn attention of researchers in geomechanics due to its mesoscopic nature since 2000. Immersed boundary method (IBM) and immersed moving boundary (IMB) are two popular schemes for coupling fluid particle in DEMLBM. This work aims at coupling DEM and LBM using the latest IBM algorithm and investigating its accuracy, computational efficiency, and applicability. Two benchmark tests, interstitial fluid flow in an ideal packing and single particle sedimentation in viscous fluid, are carried out to demonstrate the accuracy of IBM through semi‐empirical Ergun equation, finite element method (FEM), and IMB. Then, simulations of particle migration with relatively large velocity in Poiseuille flow are utilized to address limitations of IBM in DEMLBM modeling. In addition, advantages and deficiencies of IBM are discussed and compared with IMB. It is found that the accuracy of IBM can be only guaranteed when sufficient boundary points are used and it is not suitable for geomechanical problems involving large fluid or particle velocity

    A direct numerical simulation method for complex modulus of particle dispersions

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    We report an extension of the smoothed profile method (SPM)[Y. Nakayama, K. Kim, and R. Yamamoto, Eur. Phys. J. E {\bf 26}, 361(2008)], a direct numerical simulation method for calculating the complex modulus of the dispersion of particles, in which we introduce a temporally oscillatory external force into the system. The validity of the method was examined by evaluating the storage G(ω)G'(\omega) and loss G"(ω)G"(\omega) moduli of a system composed of identical spherical particles dispersed in an incompressible Newtonian host fluid at volume fractions of Φ=0\Phi=0, 0.41, and 0.51. The moduli were evaluated at several frequencies of shear flow; the shear flow used here has a zigzag profile, as is consistent with the usual periodic boundary conditions

    Traumatic middle cerebral artery aneurysm: case report and review of the literature

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    The original publication is available at www.springerlink.comArticleNEUROSURGICAL REVIEW. 30(3): 263-267 (2007)journal articl

    Researches is health of Pirarucu, Arapaima gigas: partnership between EMBRAPA-SEBRAE.

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    Aiming to deepen the scientific knowledge on health aspects of pirarucu, and attempting to improve the fingerlings survival rates a partnership was signed between SEBRAE and EMBRAPA, in collaboration with the UFT

    Clinical features of cats with aqueous tear deficiency: a retrospective case series of 10 patients (17 eyes)

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    Objectives The aim of this study was to describe the clinical findings, diagnostic test results and response to therapy of cats with Schirmer tear test 1 (STT-1) values below the reference interval. Methods The medical records of three institutions were searched for cats with ocular surface disease and STT-1 values/min, confirmed at two or more separate visits. Results Ten cats (17 eyes) were included. The mean ± SD (range) age and STT-1 values in affected eye(s) were 6.1 ± 5.7 (0.2–16) years and 2.4 ± 3.1 (0–8) mm/min, respectively. Concurrent ocular surface disease was bilateral in 5/10 cats. Clinical signs included conjunctivitis (14/17 eyes), corneal ulceration (6/17 eyes), non-ulcerative keratitis (4/17 eyes), symblepharon (4/17 eyes), eosinophilic keratitis (3/17 eyes), corneal sequestrum (3/17 eyes), corneal fibrosis (2/17 eyes) and meibomitis (2/17 eyes). Management included topically applied lacrimomimetics, antiviral drugs, corticosteroids or immunomodulatory drugs; orally administered famciclovir; or surgical procedures, in various combinations. Response to therapy (defined as an increase in STT-1 value of ⩾5 mm/min) was transient (seen at a single reassessment) in 65% of eyes and sustained (seen at ⩾2 consecutive reassessments) in 18% of eyes. Conclusions and relevance Clinical features seen in cats with low STT-1 values are described, although the association between aqueous deficiency and the reported ocular changes is unknown at this time. We encourage clinicians to assess the tear film in cats with ocular surface disease, and initiate therapy with lacrimomimetics if STT-1 values are repeatedly below normal. Such information will further define aqueous tear deficiency in cats, providing a better understanding of disease prevalence, pathogenesis and treatment

    Efeito do probiótico na evolução da inflamação granulomatosa e hematologia de tilápias do Nilo, Oreochromis niloticus.

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    A atividade probiótica de um suplemento comercial composto de três microorganismos, (3x108 UFC), Saccharomyces cerevisiae (2x108 UFC) e Aspergillus oryzae (4x106 UFC), foi avaliada através da inclusão de níveis do suplemento na dieta alimentar de tilápias do Nilo (Oreochromis niloticus).Organizado por: Sílvio Ricardo Maurano; AQUACIÊNCIA 2012

    Adenomatoid tumour of the liver

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    An unusual primary adenomatoid tumour arising in the normal liver is described. Hepatectomy was performed, and the patient is alive and free of disease 1 year postsurgery. Grossly, the tumour showed a haemorrhagic cut surface with numerous microcystic structures. Histological examination revealed cystic or angiomatoid spaces of various sizes lined by cuboidal, low-columnar, or flattened epithelioid cells with vacuolated cytoplasm and round to oval nuclei. The epithelioid cells were entirely supported by proliferated capillaries and arteries together with collagenous stroma. Immunohistochemical studies showed that the epithelioid cells were strongly positive for a broad spectrum of cytokeratins (AE1/AE3, CAM5.2, epithelial membrane antigen and cytokeratin 7) and mesothelial markers (calretinin, Wilms’ tumour 1 and D2-40). These cells were negative for Hep par-1, carcinoembryonic antigen, neural cell adhesion molecule, CD34, CD31 and HMB45. Atypically, abundant capillaries were observed; however, the cystic proliferation of epithelioid cells with vacuoles and immunohistochemical profile of the epithelioid element were consistent with hepatic adenomatoid tumour
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