770 research outputs found
ProThes: Thesaurus-based Meta-Search Engine for a Specific Application Domain
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>
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
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
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.
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
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
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
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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