7,703 research outputs found

    Equivelar and d-Covered Triangulations of Surfaces. I

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    We survey basic properties and bounds for qq-equivelar and dd-covered triangulations of closed surfaces. Included in the survey is a list of the known sources for qq-equivelar and dd-covered triangulations. We identify all orientable and non-orientable surfaces MM of Euler characteristic 0>χ(M)≥−2300>\chi(M)\geq -230 which admit non-neighborly qq-equivelar triangulations with equality in the upper bound q≤⌊12(5+49−24χ(M))⌋q\leq\Bigl\lfloor\tfrac{1}{2}(5+\sqrt{49-24\chi (M)})\Bigl\rfloor. These examples give rise to dd-covered triangulations with equality in the upper bound d≤2⌊12(5+49−24χ(M))⌋d\leq2\Bigl\lfloor\tfrac{1}{2}(5+\sqrt{49-24\chi (M)})\Bigl\rfloor. A generalization of Ringel's cyclic 7mod127{\rm mod}12 series of neighborly orientable triangulations to a two-parameter family of cyclic orientable triangulations Rk,nR_{k,n}, k≥0k\geq 0, n≥7+12kn\geq 7+12k, is the main result of this paper. In particular, the two infinite subseries Rk,7+12k+1R_{k,7+12k+1} and Rk,7+12k+2R_{k,7+12k+2}, k≥1k\geq 1, provide non-neighborly examples with equality for the upper bound for qq as well as derived examples with equality for the upper bound for dd.Comment: 21 pages, 4 figure

    Evaluating the Chinese Revised Controlling Behaviors Scale (C-CBS-R)

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    The present study evaluated the utility of the Chinese version of the Revised Controlling Behaviors Scale (C-CBS-R) as a measure of controlling behaviors in violent Chinese intimate relationships. Using a mixed-methods approach, in-depth, individual interviews were conducted with 200 Chinese women survivors to elicit qualitative data about their personal experiences of control in intimate relationships. The use of controlling behaviors was also assessed using the C-CBS-R. Interview accounts suggested that the experiences of 91 of the women were consistent with the description of coercive control according to Dutton and Goodman’s (2005) conceptualization of coercion. Using the split-half validation procedure, a receiver operating characteristics (ROC) curve analysis was conducted with the first half of the sample. The area under the curve (AUC) for using the C-CBS-R to identify high control was .99, and the cutoff score of 1.145 maximized both sensitivity and specificity. Applying the cutoff score to the second half gave a sensitivity of 96% and a specificity of 95%. Overall, the C-CBS-R has demonstrated utility as a measure of controlling behaviors with a cutoff score for distinguishing high from low levels of control in violent Chinese intimate relationships

    Microbiological Spoilage of Aviation Turbine Fuel: Part II Evaluation of a Suitable Biocide

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    Addition of ethylene glycol monoethyl ether, an anti-icing fuel additive supports microbial growth when added to aviation turbine fuel in low dosages. however, increases in its concentration to certain limits effectively prevents bioactivity in the fuel. The optimum dosage of this biocide for prevention of bioactivity in aviation turbine fuel has been studied by the specified qualitative performance tests after 18 months storage of the inhibited fuel under accelerated conditions of temperature and humidity

    Thermodynamics of viscous Matter and Radiation in the Early Universe

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    Assuming that the background geometry is filled with free gas consisting of matter and radiation and no phase transitions being occurred in the early Universe, we discuss the thermodynamics of this {\it closed} system using classical approaches. We find that essential cosmological quantities, such as Hubble parameter HH, scale factor aa and curvature parameter kk, can be derived from this simple model, which on one hand fulfills and entirely obeys the laws of thermodynamics. On the other hand, the results are compatible with the Friedmann-Lemaitre-Robertson-Walker model and the Einstein field equations. The inclusion of finite bulk viscosity coefficient derives to important changes in all these cosmological quantities. Accordingly, our picture about the evolution of the Universe and its astrophysical consequences seems to be a subject of a radical revision. We find that kk strongly depends on the thermodynamics of background matter. The time scale, at which negative curvature might take place, depends on the relation between the matter content and the total energy. Using quantum and statistical approaches, we assume that the size of the Universe is given by the volume occupied one particle and one photon. Different types of their interactions are taken into account. Expressions for HH and aa are introduced. Therefore, the expansion of the Universe turns to be accessible.Comment: 9 pages, 2 figures (3 eps graphs

    Underground Corrosion by Microorganisms Part II : Role of Anaerobic Sulphate Reducing Bacteria-Desulfotomaculum SP

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    During the course of studies on the corrosion causing soil microflora from different geoclimatic regions of India, several strains of anaerobic sulphate reducing bacteria belonging to genus Desulfotomaculum were isolated and characterised. Their corrosive action on mild steel, galvanised iron and structural aluminium, the three main metals of construction of underground structures, have been studied under laboratory conditions
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