Electrical resistivity of coal-bearing rocks under high temperature and the detection of coal fires using electrical resistance tomography

2015 ◽  
Vol 204 (2) ◽  
pp. 1316-1331 ◽  
Author(s):  
Zhenlu Shao ◽  
Deming Wang ◽  
Yanming Wang ◽  
Xiaoxing Zhong ◽  
Xiaofei Tang ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
High Temperature ◽  
Electrical Resistance ◽  
Electrical Resistance Tomography ◽  
Coal Fires

Preliminary Evaluation of Electrical Resistance Tomography for Imaging Palm Trunks

2016 ◽  
Vol 42 (2) ◽  
Author(s):  
Monica Elliott ◽  
Timothy Broschat ◽  
Lothar Göcke
Keyword(s):  
Electrical Resistivity ◽  
Cross Sections ◽  
Electrical Resistance ◽  
Fungal Pathogens ◽  
Wood Decay ◽  
Preliminary Evaluation ◽  
Electrical Resistance Tomography ◽  
High Electrical Resistivity ◽  
Southern Florida ◽  
Syagrus Romanzoffiana

In a preliminary study, electrical resistance tomography (ERT) was used to obtain trunk images of Syagrus romanzoffiana, a common ornamental palm grown in southern Florida, U.S. Seven palms, four healthy and three diseased, were evaluated in the middle of the dry season, with four located in an irrigated site and three in a non-irrigated site. Two healthy and three diseased palms were felled and cross sections obtained to examine their internal structure and compare to the tomograms obtained. ERT was effective in illustrating the relative electrical resistance value of healthy palms, as the tomograms obtained for palms situated in the irrigated site (low electrical resistivity) were distinctly different from the tomograms of palms situated in the non-irrigated site (high electrical resistivity). ERT was also effective in visualizing internal palm trunk areas affected by the fungal pathogens Ganoderma zonatum, a wood decay pathogen, and Fusarium oxysporum f. sp. palmarum, a vascular wilt pathogen, as these areas had a low electrical resistivity.

The effect of pressure on the electrical resistance of lithium, sodium and potassium at low temperatures

1962 ◽  
Vol 270 (1341) ◽  
pp. 186-211 ◽  
Keyword(s):  
Electrical Resistivity ◽  
High Temperature ◽  
Linear Relation ◽  
Electrical Resistance ◽  
Low Temperatures ◽  
Constant Density ◽  
Theoretical Predictions ◽  
Volume Coefficient ◽  
Sodium And Potassium ◽  
The Ideal

Measurements have been made of the electrical resistivity of lithium, sodium and potassium at temperatures between 2 and 300 °K and at pressures up to 3000 atm . From our results we have calculated the ideal electrical resistivity, ρ i , and its volume derivative as functions of temperature for conditions of constant density. It is shown that, as predicted by simple theory, there is a linear relation between the temperature and volume coefficients of ρ i for each metal. We conclude that the magnitude of the volume coefficient of ρ i does not, at high temperatures at least, agree with present theoretical predictions and that this coefficient is closely connected with the high-temperature value of the thermoelectric power.

scholarly journals Optimisation of Sensor Electrode Size for in Electrical Resistance Tomography Implementing Conducting Boundary Strategy

2021 ◽  
Vol 1874 (1) ◽  
pp. 012077
Author(s):  
Suzanna Ridzuan Aw ◽  
Ruzairi Abdul Rahim ◽  
Fazlul Rahman Mohd Yunus ◽  
Mohd Hafiz Fazalul Rahiman ◽  
Yasmin Abdul Wahab ◽  
...  
Keyword(s):  
Electrical Resistance ◽  
Electrical Resistance Tomography ◽  
Electrode Size ◽  
Sensor Electrode

The Influence of Bi2O3 on SiO2-Al2O3-B2O3-RO Glass Propertiesarts

2014 ◽  
Vol 887-888 ◽  
pp. 86-89
Author(s):  
Ying Liang Tian ◽  
Jing Zhang ◽  
Shi Bing Sun ◽  
Ji Ye Fan
Keyword(s):  
Electrical Resistivity ◽  
High Temperature ◽  
Expansion Coefficient ◽  
Bismuth Oxide ◽  
Sintering Temperature ◽  
Oxide Content ◽  
Basic Composition ◽  
Wide Range ◽  
Melt Annealing ◽  
Annealing Method

In the paper, regarded SiO2-Al2O3-B2O3-RO system as basic composition, high-temperature glass glaze was prepared successfully by using Bi2O3 in place of Al2O3, and traditional melt annealing method was adopted .The influence of Bi2O3 on expansion coefficient, sintering temperature, electrical resistivity was investigated by DIL-2008, SJY sintering imager, Keythley2410. The results show that the sintering temperature of glass glaze has a wide range, which can reach 270°C, so it is easy to sinter; with the increasing of bismuth oxide content, expansion coefficient of glass glaze gradually increases, whereas sintering temperature and electrical resistivity continuously decreases.

scholarly journals Cooper Pair-Like Systems at High Temperature and their Role on Fluctuations Near the Critical Temperature

1998 ◽  
Vol 12 (29n31) ◽  
pp. 3216-3219 ◽  
Author(s):  
M. Ausloos ◽  
S. Dorbolo
Keyword(s):  
Phase Transition ◽  
Electrical Resistivity ◽  
High Temperature ◽  
Critical Temperature ◽  
Oxygen Diffusion ◽  
Cooper Pair ◽  
Anomalous Behavior ◽  
Anomalous Effect ◽  
Linear Temperature ◽  
Ybco Sample

A logarithmic behavior is hidden in the linear temperature regime of the electrical resistivity R(T) of some YBCO sample below 2T c where "pairs" break apart, fluctuations occur and "a gap is opening". An anomalous effect also occurs near 200 K in the normal state Hall coefficient. In a simulation of oxygen diffusion in planar 123 YBCO, an anomalous behavior is found in the oxygen-vacancy motion near such a temperature. We claim that the behavior of the specific heat above and near the critical temperature should be reexamined in order to show the influence and implications of fluctuations and dimensionality on the nature of the phase transition and on the true onset temperature.

scholarly journals XIX.—Magnetization and Resistance of Nickel Wire at High Temperatures. Part II.

1907 ◽  
Vol 45 (3) ◽  
pp. 547-554
Author(s):  
C. G. Knott
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Electrical Resistance ◽  
British Association ◽  
Nickel Wire ◽  
Present Communication ◽  
Association Meeting ◽  
The Subject ◽  
The Wire

The experiments which form the subject of the present communication were carried out two years ago, and supplement results already published. A brief note of some of the results was read before the Society in June 1904, and was also read before the British Association Meeting at Cambridge in August of the same year.The previous paper discussed the effect of high temperature on the relation between electrical resistance and magnetization when the wire was magnetized longitudinally, that is, in the direction in which the resistance was measured.The present results have to do with the effect of high temperature on the relation between resistance and magnetization when the magnetization was transverse to the direction along which the resistance was measured.

Silicon Carbide Die Attach Scheme for 500°C Operation

2000 ◽  
Vol 622 ◽  
Author(s):  
Liang-Yu Chen ◽  
Gary W. Hunter ◽  
Philip G. Neudeck
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Electrical Resistance ◽  
Room Temperature ◽  
Semiconductor Devices ◽  
Single Crystal Silicon ◽  
Film Material ◽  
Crystal Silicon ◽  
Pure Alumina ◽  
Die Attach

ABSTRACTSingle crystal silicon carbide (SiC) has such excellent physical, chemical, and electronic properties that SiC based semiconductor electronics can operate at temperatures in excess of 600°C well beyond the high temperature limit for Si based semiconductor devices. SiC semiconductor devices have been demonstrated to be operable at temperatures as high as 600°C, but only in a probe-station environment partially because suitable packaging technology for high temperature (500°C and beyond) devices is still in development. One of the core technologies necessary for high temperature electronic packaging is semiconductor die-attach with low and stable electrical resistance. This paper discusses a low resistance die-attach method and the results of testing carried out at both room temperature and 500°C in air. A 1 mm2 SiC Schottky diode die was attached to aluminum nitride (AlN) and 96% pure alumina ceramic substrates using precious metal based thick-film material. The attached test die using this scheme survived both electronically and mechanically performance and stability tests at 500°C in oxidizing environment of air for 550 hours. The upper limit of electrical resistance of the die-attach interface estimated by forward I-V curves of an attached diode before and during heat treatment indicated stable and low attach-resistance at both room-temperature and 500°C over the entire 550 hours test period. The future durability tests are also discussed.

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