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In order to further improve crashworthiness and reduce weight, tailor-welded blanks (TWBs) have been widely applied in auto-body design. In this paper, the discrete optimization design of TWBs structures with top-hat thin-walled section subjected to front dynamic impact is performed by using Taguchi-based gray relational analysis. Material grades and thicknesses with three levels are taken as discrete design variables. The total energy absorption ( EA ), the total weight ( Mass ) and the peak crashing force ( F max ) are chosen as optimization indicators. Considering the uncertain weight ratio of responses, four different cases would be analyzed. In order to determine the optimal parameter combination more accurately and eliminate errors from range analysis, the analysis of variance (ANOVA) would be performed. The optimized results demonstrate that it is feasible to increase the crashworthiness of TWBs by increasing the gray correlation of the structure. Compared to initial structure, case 1 ( w ( F max ): w ( EA ): w ( Mass )= 1/3:1/3:1/3) has the largest improvement among the four cases, i.e., the F max and the Mass are reduced by 29.3% and 2.7%, respectively, while the EA is increased by 3.5%. The discrete optimization method with only 27 iterations is a low computing cost or cost-effective and provides some guidance for some similar structural design. More comprehensive studies are essential to optimize performance of multi-components with more discrete variables. [ABSTRACT FROM AUTHOR]

Longquan celadon is one of the most valuable treasures in Chinese ceramic history. Representative products are Ge ware (Ge meaning elder brother, black body celadon) and Di ware (Di meaning younger brother, gray body celadon) of the Song Dynasty (960–1279 A.D.). In this study, Ge and Di ware shards excavated from Wayaoyang kiln site in Longquan were collected and studied. Chemical and crystallite composition, microstructure, body and glaze thickness, firing temperature and glaze reflectance spectrum were observed and examined. Differences in raw materials and manufacturing technology between Ge and Di ware were studied. Based on the results and historical background, it was speculated that some Ge wares from Wayaoyang kiln site might be the test products of jade-like black body celadon for the imperial court. [ABSTRACT FROM AUTHOR]

The paper presents multi-sector stable IR grey body radiation source, that can be used for testing of MRT. Its main element is monolithic metal plate with a test pattern, made of material with high thermal conductivity. On the surface of the test plate the sectors of different emissivity are created during manufacturing process. As a result when viewed by a thermal camera those sectors exhibit thermal contrast depending mainly on the radiative properties of each sector. The value of thermal contrast between particular sectors can be adjusted by changing the temperature of a test plate with respect to ambient. The emissivity values of particular sectors have been calculated and the procedure of adjusting the thermal contrast has been described, as well as the technology used to create the test plate. The model of described emitter has been tested and the results of temperature values obtained from thermal camera were compared with theoretical, calculated figures. The proposed emitter is dedicated for testing and calibrating of modern observations IR systems. [ABSTRACT FROM AUTHOR]

Abstract: Extremization of a weak form for the continuum energy conservation principle differential equation naturally implements fluid convection, radiation and flux Robin boundary conditions associated with unsteady heat transfer. Combining a spatial semi-discretization via finite element trial space basis functions with time-accurate integration for computing. Closure for grey body radiation is a newly derived radiosity formulation generating piecewise discontinuous solutions, while that for natural-forced-mixed convection heat transfer is extracted from the literature. Algorithm performance, mathematically predicted by asymptotic convergence theory, is subsequently validated with data obtained in 24h diurnal field experiments for 1/8’’ and 1’’ thick aluminum plates. [Copyright &y& Elsevier]

Abstract: Emission from sapphire window material was measured by spontaneous spectroscopic and multi-wavelength pyrometer techniques. The spectral distribution as a function of wavelength fit well to the grey-body spectrum. We analyzed the emissions and discovered that they arise from shear banding, which is a typical thermal radiation. It was found that the color temperature of shocked sapphire changes linearly and regularly with stress increases from 40GPa to 59GPa but becomes monotonic for stresses from 87GPa to 120GPa. The change in behavior indicates that a shock-induced phase transformation occurs between 59GPa and 87GPa. [Copyright &y& Elsevier]

The (3 + 1) -dimensional Einstein-Gauss-Bonnet theory of gravity which breaks the Lorentz invariance in a theoretically consistent and observationally viable way has been recently suggested by Aoki, Gorji and Mukohyama [5]. Here we calculate grey-body factor for Dirac, electromagnetic and gravitational fields and estimate the intensity of Hawking radiation and lifetime for asymptotically flat black holes in this theory. Positive coupling constant leads to much smaller evaporation rate and longer life-time of a black hole, while the negative one enhances Hawking radiation. The grey-body factors for electromagnetic and Dirac fields are smaller for larger values of the coupling constant. [ABSTRACT FROM AUTHOR]