169 research outputs found
Phase statistics of the WMAP 7 year data
We performed a comprehensive statistical analysis using complex phases of the
a_lm coefficients computed from the most recent data of the Wilkinson Microwave
Anisotropy Probe (WMAP). Our aim was to confirm or constrain the presence of
non-Gaussianities in the data. We found phase correlations - that suggest
non-Gaussianity - at high-l in a_lm coefficients by applying various
statistical tests. Most of all, we detected a non-Gaussian signal reaching a
significance of 4.7 sigma using random walk statistics and simulations.
However, our conclusion is that the non-Gaussian behavior is due to
contamination from galactic foregrounds that show up in small scales only. When
masked out the contaminated regions, we found no significant non-Gaussianity.
Furthermore, we constrained the f_NL parameter using CMB simulations that mimic
primordial non-Gaussianity. Our estimate is f_NL=40 +/- 200, in agreement with
previous measurements and inflationary expectations.Comment: 4 pages, 4 figures, Accepted for Publication in A
Synthesis of Shape-Tailored WO3 Micro-/Nanocrystals and the Photocatalytic Activity of WO3/TiO2 Composites
A traditional semiconductor (WO3) was synthesized from different precursors via hydrothermal crystallization targeting the achievement of three different crystal shapes (nanoplates, nanorods and nanostars). The obtained WO3 microcrystals were analyzed by the means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and diffuse reflectance spectroscopy (DRS). These methods contributed to the detailed analysis of the crystal morphology and structural features. The synthesized bare WO3 photocatalysts were totally inactive, while the P25/WO3 composites were efficient under UV light radiation. Furthermore, the maximum achieved activity was even higher than the bare P25's photocatalytic performance. A correlation was established between the shape of the WO3 crystallites and the observed photocatalytic activity registered during the degradation of different substrates by using P25/WO3 composites
Synthesis of Shape-Tailored WO3 Micro-/Nanocrystals and the Photocatalytic Activity of WO3/TiO2 Composites
A traditional semiconductor (WO3) was synthesized from different precursors via hydrothermal crystallization targeting the achievement of three different crystal shapes (nanoplates, nanorods and nanostars). The obtained WO3 microcrystals were analyzed by the means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and diffuse reflectance spectroscopy (DRS). These methods contributed to the detailed analysis of the crystal morphology and structural features. The synthesized bare WO3 photocatalysts were totally inactive, while the P25/WO3 composites were efficient under UV light radiation. Furthermore, the maximum achieved activity was even higher than the bare P25's photocatalytic performance. A correlation was established between the shape of the WO3 crystallites and the observed photocatalytic activity registered during the degradation of different substrates by using P25/WO3 composites
Szerkezeti topolĂłgia = Structural topology
Numerikus megoldásokat állĂtottunk elĹ‘ a körpárok Ă©s körhármasok gömbön valĂł legsűrűbb elhelyezĂ©sĂ©nek problĂ©májára, Ă©s szimmetria alapĂş vizsgálatokat vĂ©geztĂĽnk a gömbi körelhelyezĂ©s gráfjának Danzer-fĂ©le merevsĂ©gĂ©re vonatkozĂłan. Egy általunk bevezetett gömbölyűsĂ©gi kritĂ©rium alapján optimális, gömböt közelĂtĹ‘ poliĂ©dereket konstruáltunk. A szakrális Ă©pĂĽleteken elĹ‘fordulĂł csillagpoliĂ©derekre alakmeghatározást Ă©s számĂtĂłgĂ©pes rekonstrukciĂłt hajtottunk vĂ©gre. Konvex testekre vonatkozĂłan több tĂ©telt bizonyĂtottunk. Meghatároztuk a gömbi Ă©s tĂ©rbeli trivalens szálhálĂłzatok megfeszĂthetĹ‘sĂ©gĂ©nek feltĂ©teleit. Gömbi koordinátákban Ărtuk fel a gömbfelszĂnre illeszkedĹ‘ csuklĂłs rĂşdszerkezetek egyensĂşlyi Ă©s kompatibilitási egyenleteit, Ă©s állĂtottuk elĹ‘ a szerkezet potenciálfĂĽggvĂ©nyĂ©t. BebizonyĂtottuk, hogy egy tĂşlhatározott, háromszorosan szimmetrikus Bricard-mechanizmus esetĂ©ben bizonyos paramĂ©ter Ă©rtĂ©keknĂ©l elĹ‘fordulhat a kompatibilitási Ăşt elágazása. A katasztrĂłfaelmĂ©letet kompatibilitási utak elágazásának vizsgálatára alkalmaztuk. Az itt elĹ‘fordulĂł kettĹ‘scsĂşcs-katasztrĂłfával kapcsolatban egy olyan modellcsaládot elemeztĂĽnk, amely a kettĹ‘scsĂşcs-katasztrĂłfa nĂ©gy alosztályán is keresztĂĽlhalad. | Numerical solutions are established to the problem of the densest packing of pairs and triplets of circles on a sphere, and symmetry extended analysis of the Danzerian rigidity of the packing graphs is executed. On the basis of a sphericity criterion introduced by us, polyhedra approximating the sphere are constructed. Shape determination and computer aided reconstruction is done for star polyhedra occurring on sacred buildings. A number of theorems are proved for convex bodies. Criteria of stressability of spherical and spatial trivalent fibre nets are determined. Equilibrium and compatibility equations as well as potential function of bar-and-joint assemblies lying on the surface of a sphere are written with spherical co-ordinates. It is proved that, for certain parameter values, there exists bifurcation of the compatibility path of an overconstrained, threefold symmetric Bricard linkage. Catastrophe theory is applied for investigation of bifurcation of compatibility paths. Concerning double cusp catastrophe, a family of models is analysed, which goes through four subclasses of the double cusp catastrophe
ASSESSING THE POSSIBLE INTERACTION BETWEEN CARDUUS MARIANUS AND DIETARY DEOXYNIVALENOL ON CAECAL MICROBIOTA AND FERMENTATION OF GROWING RABBITS
Contamination of feed with mycotoxins is a common problem encountered in animal farming. Mycotoxin exposure can affect adversely the health of animals. In rabbits caecal fermentation is an essential digestive process being indication of physiological alterations. Deoxynivalenol (DON) is one of the most frequent contaminants of grains which affect the growth of monogastric animals. Data about dietary DON and its effect in rabbits are scarce. Medicinal plants are often used as feed additives to enhance the performance of the animals. Carduus marianus (milk thistle) is known for its hepatoprotective and antioxidant effects (among others) but no data are available about the effect on rabbit caecum. Considering the aforementioned, the aim of this study was to assess the possible interactive effect of Carduus marianus and DON on the caecum of growing rabbits. 75 Pannon White rabbits were reared for six weeks from 35 (after weaning) till 77 days of age. Rabbits received the following diets: control (C), control with DON (CT), control supplemented with C. marianus in 0,5% (H1), control supplemented with C. marianus in 0,5% and DON (H1T), control supplemented with C. marianus in 1% (H2) and control supplemented with C. marianus in 1% and DON (H2T). On slaughter, caecum was collected for the analysis of total volatile fatty acids (VFA) and the microbiota of the caecum, pH of the caecum was also recorded. There was no significant difference in total VFA concentration or individual VFA. Number of aerobic bacteria significantly differed among toxin and non-toxin groups. DON affected adversely the number of aerobic bacteria. An interactive effect of DON and Carduus marianus on E.coli number was observed. There was no effect on total or individual VFA amounts
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