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Paper materials are used as the insulation of power transformers. Over time these materials slowly degrade, until they reach a point when they no longer function effectively as transformer insulation, and the transformer has then reached its end of life. The aging rate of paper is affected by temperature, water, oxygen and acids. Investigations have been performed previously on Kraft and Kraft thermally...
We present a methodology to characterize BAW resonators both linearly and nonlinearly. The procedure uses physical modeling along with measurements that exploit different manifestations of the nonlinear phenomena to identify the dominant linear and nonlinear material properties. Such methodology allows obtaining consistent nonlinear material parameters by use of two independents measurements.
The flash method for measuring thermophysical properties (TPP) has attracted wide-spread interest since it was introduced by Parker et al (1961). In an extension of this technique, we introduced a front-face flash-monitoring method (FFFMM) in which a radiative source delivering short heat pulses and an infrared detector to measure temperature excursion with time are positioned on the same side of...
The influence has been studied of the absorbing layers to the efficiency of solar drying chamber. Proposed solar drying chamber walls are composed of translucent coating from outside and absorbing layers are placed its inside. A technique is used for calculating the effective value of transparent wall's transmittance and investigated average system efficiency with effective value of wall transmittance...
A physical model is used to describe one or more field-size phenomena and, in representing them, it generates other quantities, which are the final output of the system. Sometimes the required thorough measurement of such quantities can lead to lose the total perception of the phenomenon under investigation. Digital image processing can not and should not obviously replace the measurements, but it...
Numerical modeling of high temperature pressure pipes including delaminations were constructed using ANSYS, then heat flux and convection are loaded on the outside surface. The influence of pulse excitation parameters, depth of defects, thickness of defects, length of defects on maximum thermal contrast and time for maximum thermal contrast are analysised. Length of defects are measured by using the...
Fading at room temperature is one of the most important properties of TL material. The purpose of the present studies is to find out the suitability of natural salt extracted from rivers of Mizoram for dosimetry applications. TL analysis of the gamma irradiated samples stored at room temperature was done within 2 hours, after 48 hours and 96 hours of irradiation. Experimental glow curves were fitted...
The Hard Disk Drive is the important storage component in computer. The high volume of Hard Disk Drive manufacturing is required. The cost improvements are strictly focused on yield, direct material, indirect material, and operation cost. The defect reduction is a important key to improve cost. The small percentage of defect reduction will contribute the huge profit for manufacturing due to the high...
High-concentration anaerobic fermentation of cow manure was investigated using anaerobic batch reactors under laboratory conditions at 20 °C. The quadratic orthogonal rotational combination design was employed. The influencing law of the temperature, the liquid concentration and retention time on prop ionic acid content was explored. The ranges of temperature, liquid concentration and retention time...
This paper analyzed ⋀ item in the gravitational field equation of Einstein from the perspective of the universe symmetry, pointed out the ⋀ term exists is the ether existence. In the transform of Euclid, allows the physical information superluminal. Ether is light and superluminal information carrier.
In general, different coefficients of thermal expansion (CTE) values of constitutive materials are considered as the main cause of warpage for flip chip packages. Accordingly, during the past years, the cure-induced volume shrinkage in integrated circuit packages has been neglected in warpage simulation. However, in recent years, there are more and more evidences showing that it is not sufficient...
In this paper, the liquidus temperature of nNaF·AlF3-Al2O3-ZrO2 molten salt system was determined by thermal analysis method. The effects of molar ratio of NaF and AlF3, and ZrO2 concentration on the liquidus temperature were studied by orthogonal regression experimental design method. The results show that the trends of liquidus temperatures of melts with five different molar ratios of NaF and AlF...
In this paper a finite element analysis (FEA) of machining for AISI1045 is presented. In particular, the thermodynamical constitutive equation (T-C-E) in FEA is applied for both workpiece material and tool material. Cutting temperature and tool wear depth are predicted. The comparison between the predicted and experimental cutting temperature and tool wear depth are presented and discussed. The results...
Taking sealed boxes as the research object, the author analyzes the main source of its moisture content. Based on the permeability mechanism of the sealed boxes and the moisture mechanism of the items inside the boxes, the paper establishes the mathematical model of the relative humidity inside changing over time, applying MATLAB to make a simulation analysis of the mathematical model. The simulation...
A radiosity model used for predicting effective hyperspectral emissivity spectra and radiant temperatures for rough surfaces has been developed. Here we compare the computer model results to analytic model results in order to verify that the computer model is working properly, and validate the model results by comparison to spectra measured in the field by an hyperspectral imaging spectrometer. We...
Microwave-assisted extract process for flavonoids from ginger (FG) was studied. Influences of concentration of extracting agent, microwave power, material ratio and irradiation time on the extraction were investigated. From orthogonal experiments the optimum extracting parameters were determined as follows: microwave power, 640W, concentration of alcohol, 80%, the materials ratio, 1:30 (W: V) and...
Tobermorite is a mineral material with good ion exchange properties. The potassium feldspar ore from Lushi country is muscovite syenite. Potassium feldspar was hydrothermally decomposed with CaO as an additive, and then tobermorite nano-scale powder was synthesized. Based on the research work of our group, the adsorption property of tobermorite to Pb2+ from aqueous solution was studied. The factors...
The transient and steady-state thermal modelling of a power bus bar used in automobile power electrical architectures is presented in this paper. Using the developed model, the current carrying capacity, also called ampacity, of this kind of power cable can be accurately predicted. After brief information about bus bars for hybrid-electric vehicle (HEV) and electric vehicle (EV), the study then focuses...
The main objective of this paper is to characterise and numerically model the sorption of water vapour in three commercially available water blocking tapes for medium and high voltage extruded cables. The main purpose of these tapes is to avoid longitudinal water penetration. However, the swelling tapes can also delay radial water ingress in the cable, thus delaying the formation of water trees and...
A physical yet analytical phase change memory (PCM) model simultaneously accounting for thermal and electrical conductivities is presented. Due to the physics based nature of the model, the essential temperature from heating and cooling of PCM during operation is instantaneously updated. More importantly, the model can be applied to non-conventional circuit design technique. We show that for the first...
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