Transportation noise contains significant low frequency components. It is difficult to sound insulate buildings against transportation noise because wall cavities are only effective in increasing sound insulation above the mass-air-mass resonance frequency. Stud walls can also have a significant structural resonance in this low frequency range, although it is not yet clear if this is significan...

The current multi-layer insulation used in the extravehicular mobility unit (EMU) will not be effective in the atmosphere of Mars due to the presence of interstitial gases. Alternative thermal insulation means have been subjected to preliminary evaluation by NASA to attempt to identify a material that will meet the target conductivity of 0.005 W/m-K. This study analyzes numerically the thermal ...

1.1 The computer programs included in this practice provide a calculational procedure for predicting the heat loss or gain and surface temperatures of insulated pipe or equipment systems. This procedure is based upon an assumption of a uniform insulation system structure, that is, a straight run of pipe or flat wall section insulated with a uniform density insulation. Questions of applicability...

Insulating concrete is a material designed to reduce heat conduction with pores/insulations, and these pores strongly affect the material characteristics. In general, the insulation effect is directly proportion to the pore volume, while the material strength decreases as the porosity increases. To overcome this contrary, anisotropic insulations with different spatial distributions are proposed...

According to the European prestandard ENV 342:1998, the thermal insulation of cold-protective clothing is measured with a thermal manikin. Systematic studies on the reproducibility of the values, measured with different types of clothing on the commonly used standing and walking manikins, have not been reported in the literature. Over 300 measurements were done in 8 different European laborator...

In a graph G, a k-insulated set S is a subset of the vertices of G such that every vertex in S is adjacent to at most k vertices in S, and every vertex outside S is adjacent to at least k + 1 vertices in S. The insulation sequence i0, i1, i2, . . . of a graph G is defined by setting ik equal to the maximum cardinality of a k-insulated set in G. We determine the insulation sequence for paths, cy...

Magnet coil insulation consists of inorganic materials such as glass fiber, fillers, and organic thermosetting resins. Most of the usual insulation systems are damaged if subjected to high radiation levels such as those anticipated at the Stanford Linear Accelerator, where the expected dose rate may be as high as lOi rads per year. This paper describes tests carried out at SLAC in which several...

HVDC (high voltage direct current) transmission is an effective way to transport electrical power over long distances by using direct current. The insulation system of HVDC components has to be designed for both AC and DC field distributions. It consists of mineral oil and pressboard. The used insulation material behavior has not been completely understood under DC stress. In this paper, electr...

Insulation co-ordination and the risk of failure for insulation can be predicted if critical flashover (CFO) and insulation withstand voltages are known. The paper aims at using the statistical method of evaluating the critical flashover and the withstand voltage for an airgap distance of 10cm. The work was carried out with a point-plane electrode (needle point) arrangement using air as the die...

The condition of the internal cellulosic paper and oil insulation are of concern for the performance of power transformers. Over the years, a number of methods have been developed to diagnose and monitor the degradation/aging of the transformer internal insulation system. Some of this degradation/aging can be assessed from electrical responses. Currently there are a variety of electrical-based ...