1,675 research outputs found

    On the Integral Law of Thermal Radiation

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    The integral law of thermal radiation by finite-size emitters is studied. Two geometrical characteristics of a radiating body or a cavity, its volume and its boundary area, define two terms in its radiance. The term defined by the volume corresponds to the Stefan– Boltzmann law. The term defined by the boundary area is proportional to the third power of temperature and inversely proportional to emitter’s effective size, which is defined as the ratio of its volume to its boundary area. This generalized law is valid for arbitrary temperature and effective size. It is shown that the cubic temperature contribution is observed in experiments. This term explains the intrinsic uncertainty of the NPL experiment on radiometric determination of the Stefan–Boltzmann constant. It is also quantitatively confirmed by data from the NIST calibration of cryogenic blackbodies. Its relevance to the size of source effect in optical radiometry is proposed and supported by the experiments on thermal emission from nano-heaters

    Finite temperature quantum field theory in the heat kernel method

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    Cluster Exploration using Informative Manifold Projections

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    Dimensionality reduction (DR) is one of the key tools for the visual exploration of high-dimensional data and uncovering its cluster structure in two- or three-dimensional spaces. The vast majority of DR methods in the literature do not take into account any prior knowledge a practitioner may have regarding the dataset under consideration. We propose a novel method to generate informative embeddings which not only factor out the structure associated with different kinds of prior knowledge but also aim to reveal any remaining underlying structure. To achieve this, we employ a linear combination of two objectives: firstly, contrastive PCA that discounts the structure associated with the prior information, and secondly, kurtosis projection pursuit which ensures meaningful data separation in the obtained embeddings. We formulate this task as a manifold optimization problem and validate it empirically across a variety of datasets considering three distinct types of prior knowledge. Lastly, we provide an automated framework to perform iterative visual exploration of high-dimensional data

    Comparative research of effectiveness of cellulose and fiberglass porous membrane carriers for bio sampling in veterinary and food industry monitoring

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    The aim of proposed research is to study the applicability of fiberglass porous membrane materials in a new strip format for dried blood storage in food industry monitoring. A comparative analysis of cellulosic and fiberglass porous membrane materials was carried out to obtain dried samples of serum or blood and the possibility of further species-specific analysi

    Observation of intersexuality in land hermit crabs (Anomura: Coenobitidae)

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    We report here the first observation of intersexuality in a land hermit crab (Coenobitidae). Three species of land hermit crabs from Okinawa were investigated. In the population of the terrestrial hermit crab Coenobita rugosus two per cent of males were found to be intersex. Besides the true male gonopores on the coxae of the 5th pair of pereopods, they had additional openings on the coxae of the 3rd pair of pereopods. Both specimens examined had a normally developed male reproductive system. In the populations of two other species studied, C. brevimanus and C. purpureus, however, no intersex individuals have been found. Examples of intersexuality in decapod crustaceans are discussed and putative explanations of this phenomenon in land hermit crabs are proposed

    LOW-FREQUENCY PULSE DIELECTRIC SPECTROMETER.

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    Apparatus is described for study of dispersion of the dielectric constants of low-conducting dielectrics in the time range of 5. 10** minus **7-3. 10**2 sec. The charge response of a measuring capacitor to a voltage discontinuity is recorded in a logarithmic time scale

    Calculation of resonances in the Coulomb three-body system with two disintegration channels in the adiabatic hyperspherical approach

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    The method of calculation of the resonance characteristics is developed for the metastable states of the Coulomb three-body (CTB) system with two disintegration channels. The energy dependence of K-matrix in the resonance region is calculated with the use of the stabilization method. Resonance position and partial widths are obtained by fitting the numerically calculated K(E)-matrix with the help of the generalized Breit-Wigner formula.Comment: Latex, 11 pages with 5 figures and 2 table
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