770 research outputs found

    ProThes: Thesaurus-based Meta-Search Engine for a Specific Application Domain

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    In this poster we introduce ProThes, a pilot meta-search engine (MSE) for a specific application domain. ProThes combines three approaches: meta-search, graphical user interface (GUI) for query specification, and thesaurus-based query techniques. ProThes attempts to employ domain-specific knowledge, which is represented by both a conceptual thesaurus and results ranking heuristics. Since the knowledge representation is separated from the MSE core, adjusting the system to a specific domain is trouble free. Thesaurus allows for manual query building and automatic query techniques. This poster outlines the overall system architecture, thesaurus representation format, and query operations. ProThes is implemented on J2EE platform as a Web service.The project was supported in part by the Russian Fund of Basic Research, grant # 03-07-90342

    Field induced evolution of regular and random 2D domain structures and shape of isolated domains in LiNbO<sub>3</sub> and LiTaO<sub>3</sub>

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    The shapes of isolated domains produced by application of the uniform external electric field in different experimental conditions were investigated experimentally in single crystalline lithium niobate LiNbO3 and lithium tantalate LiTaO3. The study of the domain kinetics by computer simulation and experimentally by polarization reversal of the model structure using two-dimensional regular electrode pattern confirms applicability of the kinetic approach to explanation of the experimentally observed evolution of the domain shape and geometry of the domain structure. It has been shown that the fast domain walls strictly oriented along X directions appear after domain merging

    Influence of waste glass in the foaming process of open cell porous ceramic as filtration media for industrial wastewater

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    This paper reports the development and testing results of a prototype ceramic filter with excellent sorption properties (<99% elimination in 5 min) leading to good efficacy in the removal of industrial contaminants (Reactive Bezaktiv Turquoise Blue V-G (BTB) dye). The novelty in the investigation lies in developing the filter material obtained from the recycling of waste glass combined with highly porous open-cell clay material. This newly developed material showed a significant reduction in the energy requirements (sintering temperature required for the production of industrial filters) thus addressing the grand challenge of sustainable and cleaner manufacturing. The methodology entails sintering of the clay foam (CF) at temperatures ranging from 800 to 1050 °C and blending it with 5%, 7% and 10 wt% milled glass cullet. One of the aims of this investigation was to evaluate and analyse the effect of the pH of the solution, contact time and equilibrium isotherm on the sorption process and the mechanical compressive strength, porosity, water uptake. From the kinetic studies, it was discovered that the experimental results were well aligned with the pseudo-second-order model and chemisorption was discovered to be a mechanism driving the adsorption process. These findings are crucial in designing cost-effective industrial filtration system since the filter material being proposed in this work is reusable, recyclable and readily available in abundance. Overall, the pathway for the reuse of waste glass shown by this work help address the sustainability targets set by the UN Charter via SDG 6 and SDG 12

    Vacuum effects in an asymptotically uniformly accelerated frame with a constant magnetic field

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    In the present article we solve the Dirac-Pauli and Klein Gordon equations in an asymptotically uniformly accelerated frame when a constant magnetic field is present. We compute, via the Bogoliubov coefficients, the density of scalar and spin 1/2 particles created. We discuss the role played by the magnetic field and the thermal character of the spectrum.Comment: 17 pages. RevTe

    Novel hybrid method to additively manufacture denser graphite structures using Binder Jetting.

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    This study introduces two hybrid processes integrating an additive manufacturing technique with post-processing treatments namely (i) Binder Jetting Printing (BJP) + Cold Isostatic Pressing (CIP) + cycle and (ii) BJP + cycle where cycle refers to a sequence of Impregnation-Drying-Pyrolysis. These two new processes yielded additively manufactured parts with higher density and reduced defects/porosities. As a testbed, we used these new processes to fabricate graphite structures. The samples produced by both methods were compared with each other and benchmarked to the samples produced by (a) BJP alone and (b) Traditional uniaxial pressing like compaction moulding. Various characterisation methods were used to investigate the microstructure and mechanical properties which showed that the porosity of hybrid manufactured samples reduces from 55% to a record 7%. This technological pathway is expected to create a new avalanche of industrial applications that are hitherto unexplored in the arena of hybrid additive manufacturing with BJP method

    Induced magnetic anisotropy features in FeCrSiBNbCu nanocrystalline alloy: Role of stress distribution proven by direct X-ray measurements

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    Fe73.5-xCrxSi13.5B9Nb 3Cu1 (x = 1, 2, and 3) amorphous ribbons were prepared by single roller rapid quenching technique. Both conventional and stress annealing at 520 C for 2 h at the value of the specific load of 150 MPa resulted in the formation of a nanocrystalline structure with average grain size about 13 nm. No significant differences in crystallite size were observed for all samples under consideration. The crystallite orientations were practically isotropic indicating no texture in the samples of all types. For all conventionally annealed ribbons a longitudinal effective magnetic anisotropy with an easy magnetization axis parallel to the ribbon axis was observed. For all stress annealed ribbons a transverse induced magnetic anisotropy with the anisotropy constant value of about 1800 ± 50 J/m3 was evident. Induced magnetic anisotropy features in FeCrSiBNbCu nanocrystalline alloy, namely an importance of the stress distribution was proven by direct X-ray measurements. A very good correlation between the induced magnetic anisotropy constant values and anisotropic stress distribution was observed. © 2013 Elsevier B.V. All rights reserved

    The Angular Momentum Operator in the Dirac Equation

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    The Dirac equation in spherically symmetric fields is separated in two different tetrad frames. One is the standard cartesian (fixed) frame and the second one is the diagonal (rotating) frame. After separating variables in the Dirac equation in spherical coordinates, and solving the corresponding eingenvalues equations associated with the angular operators, we obtain that the spinor solution in the rotating frame can be expressed in terms of Jacobi polynomials, and it is related to the standard spherical harmonics, which are the basis solution of the angular momentum in the Cartesian tetrad, by a similarity transformation.Comment: 13 pages,CPT-94/P.3027,late

    Relationship between various pathways of cellular death at distinct stages of ontogenesis in normal state and systemic diseases of connective tissue

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    The aim of our research  was to reveal quantitative ratios existing between  the pathways of cellular death in normal state, as well as in immunocomplex pathology. The proportion of different pathways of cell death (autophagy, apoptosis, necrosis) in autoimmune (systemic  connective tissue diseases (SDCT) – rheumatoid arthritis (RA), systemic lupus erythematosus (SLE)  and systemic scleroderma (SSD) is a subject of age-related changes. On the one hand, aging process can be considered a genetically determined overall decrease in adaptive potential of the body, and a systemic  age-related chronic inflammatory response, with a pronounced cytokine proinflammatory shift. On the other hand, a polygenic decrease in energy and information capacity  of the cells, represent the basis of multisystem and multiorgan functional and metabolic disorders  in SDCT.Blood plasma  samples were analyzed  in the patients of two age groups. The first group consisted of 10 SLE cases (4 men and 6 women, average age 43.8 years), 13 patients with RA (5 men and 8 women, average age 45.6 years),  7 SSD (women, average age 35.8 years),  and 10 healthy  donors  (6 men and 4 women, average age 40.7 years). The second age group consisted of 9 SLE cases (2 men and 7 women, average age 69.8 years), 10 patients with RA (5 men and 5 women, average age 65.6 years), 5 patients with SSD (women, average age 65.7 years) and 12 healthy  donors  (normal biological  aging – 7 men and 5 women, average age 64.7 years). The data presented in this paper  were obtained with informed consent of the  patients. When  carrying  out  biomedical research, we followed  internationally recognized ethical  standards of the Helsinki Declaration (International Medical Association, 1996, revision  2013). The proportion of various cell death  types (autophagy, apoptosis, necrosis) in  autoimmune disorders  (systemic  diseases  of connective tissue,  SDCT), i.e.,  rheumatoid arthritis (RA), systemic  lupus erythematosus (SLE), and systemic  scleroderma (SSD) proved to be subject to age-dependent changes. Close  interaction were revealed  between  the  ways of cellular  death  in SDCT (most  pronounced in SLE), correlating with age changes and clinical  manifestations of autoimmune process. In SDCT, the affected tissues exhibit all types of cellular  death, however, degree of their expression  depends on the disease nosology. Upon systemic diffuse pathology of connective tissue, autophagy (especially in case of SLE and RA) is directly involved in development of immune response  and inflammatory process.In normal biological  aging, like as in SDCT, one may observe a sharply increased activity of the metabolic trigger – AMP-activated protein kinase (AMPK), a sensor of intracellular energy, along with shifted acid-base equilibrium. The quantity of active oxygen radicals  increases, oxidoreductive potential of the cells is changed, with  activation of cellular  destruction components. Activity  of cytokine system  in the  organism  is changed causing  apoptosis regulation; expression  of chaperons is decreased, and  the immune-oxygenase homeostasis is also displaced. Inhibition of genetically determined process of death  of cells (apoptosis) comprises the basis for development of autoimmune diseases. Transition of late apoptosis into secondary necrosis  is accompanied by decrease of antioxidant protection and  development of autoimmune pathology. The  chaperon-mediated induction of immune response as the signaling mechanism of autophagy, being evolutionarily fixed in mammals only, may be the common central  link and “the  molecular switch”  causing both development of autoimmune diseases of connective tissue, and aging processes
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