Влияние содержания технического углерода на температурные зависимости электропроводности полимерного композита

It was found that in the region of the percolation threshold, depending on the dominance of one or another conduction mechanism, the temperature dependence of the specific volume resistivity ρ(Т) of the polymer composite based on a matrix of ethylene vinyl acetate is significantly transformed. With an increase in the CB content, there is a decrease by several orders of magnitude in the maximum value of the relative resistivity ρ(Т)max/ρ20 in its temperature dependence. Peroxide crosslinking of matrix macromolecules leads to a change in the nature of the temperature dependence of resistivity.

Heat Treatment of Cast and Cold Rolled Al–Yb and Al–Mn–Yb–Zr Alloys

The microstructure, electrical properties and microhardness of as-cast and cold rolled AlYb and AlMnYbZr alloys were investigated. The addition of Mn, Yb and Zr has a positive influence on grain size. A deformed structure of the grains with no changes of their size was observed after cold rolling. The Al3Yb particles coherent with the matrix were observed in the AlYb alloys. The size of the particles was about 20 nm in the initial state; after isochronal treatment up to 540 °C the particles coarsen, and their number density was lower. The deformation has a massive effect on the microhardness behavior until treatment at 390 °C, after which the difference in microhardness changes between as-cast and cold rolled alloys disappeared. Relative resistivity changes show a large decrease in the temperature interval of 330–540 °C which is probably caused by a combination of recovery of dislocations and precipitation of the Al3(Yb,Zr) particles. Precipitation hardening was observed between 100 and 450 °C in the AlYb alloy after ageing at 625 °C/24 h and between 330 and 570 °C in the AlMnYbZr alloy after ageing at 625 °C/24 h.

Analysis of geological-geophysical materials and qualitative assessment of the oil and gas perspectives of the Yuzhno-Kharbizhinsky area (Northern Caucasus)

На современном этапе развитие нефтяной промышленности Российской Федерации невозможно без пополнения ресурсной базы и поэтому актуальной задачей является поиск новых методик оценки и анализа нефтегазоносности перспективных участков. Цель исследований: анализ емкостно-фильтрационных свойств пород коллекторов прикамского горизонта в пределах Южно-Харбижинского участка, с целью прогноза емкостно-фильтрационных параметров на участке Восточный. Методика исследований. Для выполнения анализа емкостно-фильтрационных и геолого-геофизических параметров пород коллекторов кумской свиты Южно-Харбижинского участка, были построены графики изменчивости емкостно-фильтрационных и геолого-геофизических параметров и проведен их корреляционный анализ. Для этого были использованы данные ГИС и данные лабораторных исследований коллекторов, полученные при бурении скважины №88-РД. Оценка коэффициента пористости, объемной плотности, минералогической плотности и плотности насыщенности пород определена на стадии оценки месторождений по методикам А.М. Нечая и Б.Ю. Вендельштейна, Н.В. Манчевой, базирующимся на комплексной интерпретации БК (БКЗ) – НГК и БК (БКЗ) – НГК – ПС. Результаты исследований. Значимой положительной корреляционной связью обладают следующие пары параметров: коэффициент пористости и удельное сопротивление пород, коэффициент пористости и относительное сопротивление пород, коэффициент пористости и объемная плотность, коэффициент пористости и плотность минералогическая, коэффициент пористости и плотность насыщенных пород, удельное сопротивление пород и относительное сопротивление пород, удельное сопротивление пород и объемная плотность, удельное сопротивление пород и плотность минералогическая, удельное сопротивление пород и плотность насыщенных пород, относительное сопротивление пород и объемная плотность, относительное сопротивление пород и плотность минералогическая, относительное сопротивление пород и плотность насыщенных пород, объемная плотность и плотность минералогическая, объемная плотность и плотность насыщенных пород, плотность минералогическая и плотность насыщенных пород. Наблюдается зависимость пористости от сопротивления, что указывает на наличие в породах коллектора углеводородов, т.е. с увеличением пористости увеличивается сопротивление, что также наблюдается на графиках.Изучив распределение показателей на Южно-Харбижинском участке по одному горизонту можно сделать вывод, что эти показатели различаются очень слабо, что свидетельствует об однородности свойств пласта. Качественные показатели остаются без изменения. На Восточном участке можно ожидать схожие показатели. Наличие промышленных скоплений углеводородного сырья оценивается как весьма вероятное At the present stage, the development of the oil industry of the Russian Federation is impossible without replenishing the resource base, and therefore an urgent task is to search for new methods for assessing and analyzing the oil and gas content of promising areas. Aim. Analysis of the reservoir-filtration properties of reservoir rocks of the Kama horizon within the Yuzhno-Kharbizhinsky area, in order to predict the reservoir-filtration parameters for the Vostochny area. Methods. To analyze the reservoir-filtration and geological-geophysical parameters of the reservoir rocks of the Kuma suite of the Yuzhno-Kharbizhinsky area, graphs of the variability of the reservoir-filtration and geological-geophysical parameters were constructed and their correlation analysis was carried out. For this, well logging data and data from laboratory studies of reservoirs obtained during drilling of well No. 88-RD were used. The estimation of the porosity coefficient, bulk density, mineralogical density and saturation density of rocks were determined at the stage of assessing deposits according to the methods of A.M. Nechaya and B.Yu. Wendelstein, N.V. Mancheva, based on a comprehensive interpretation of BK (BKZ) - NGK and BK (BKZ) - NGK - PS. Results. The following pairs of parameters have a significant positive correlation: porosity coefficient and resistivity of rocks, porosity coefficient and relative resistivity of rocks, porosity coefficient and bulk density, porosity coefficient and mineralogical density, porosity coefficient and density of saturated rocks, rock resistivity and relative rock resistance, rock resistivity and bulk density, rock resistivity and mineralogical density, rock resistivity and saturated rock density, rock relative resistivity and bulk density, rock relative resistivity and mineralogical density, rock relative resistivity and saturated rock density, bulk density and mineralogical density, bulk density and density of saturated rocks, mineralogical density and density of saturated rocks.A dependence of porosity on resistance is observed, which indicates the presence of hydrocarbons in the reservoir rocks, i.e. with an increase in porosity, resistance increases, which is also observed in the graphs.Having studied the distribution of indicators in the Yuzhno-Kharbizhinsky area along one horizon, it can be concluded that these indicators differ very slightly, which indicates the homogeneity of the reservoir properties. Qualitative indicators remain unchanged. Similar performance can be expected in the Eastern section. The presence of industrial accumulations of hydrocarbon raw materials is assessed as highly probable

A Study of Piezoresistivity of Graphite Cement Mortar Specimen Embedded Double Electrodes by a Series Connected AC Circuit

Cement mortar shows piezoresistivity after being mixed with small amount of graphite, thus the resistivity of the material will changed with stress. In this study, specimens embedded double electrodes which made of cement based material with small amount of graphite (3 wt.% of cement) are used in the experiments of one-time loading and cyclic loading, and the relative resistivity are measured by a series connected AC circuit. The results show that the specimens’ piezoresistivity goes down while the stress increases, and different curves of piezoresistivity can be observed in experiments with different loading methods. The relative resistivities of the specimen show a similar change as strain.

Identification and Characterization of Phase Transformations by the Resistivity Measurements in Mg-RE-Mn Alloys

The response of the relative resistivity changes to the isochronal annealing was measured in MgSc, MgScMn and MgYNdScMn alloys. The derivatives of the annealing curves were fitted by Gaussian functions to determine and separate the temperature ranges of the phase transformations taking place. The Austin-Rickett kinetics is argued to justify this procedure for diffusion driven transformations. TEM observation verified the conclusions drawn from the procedure.

Combinatorial Optimization of Low Electrical Resistivity Pd-based Thin Film Metallic Glass

In order to optimize low electrical resistivity compositions of Pd-based thin film metallic glass (TFMG), Combinatorial arc plasma deposition (CAPD) was employed. A Pd-based continuous compositionally-graded thin film was deposited using CAPD in the experiments. To deposit the composition-grade of the Pd-rich thin film, the number of shots and the plasma strength were controlled. The deposited thin film was separated into 1,089 samples for measurements. The thickness, composition, phase and relative resistivity of these samples were measured respectively. And three amorphous CAPD samples exhibiting low relative resistivity were selected. To determine whether these were TFMG compositions, their compositions were reproduced on sputter-deposited samples and their Tg and Tx were measured. It was found that the sample of Pd81Cu5Si14 at.% showed the lowest absolute resistivity (60 μΩ·cm) and the largest temperature range of supercooled liquid region (SCLR) i.e., 60 K among all samples. The resistivity was 19% lower than conventional Pd-based TFMG and SCLR was two and half times as large. The tensile strength was higher than the conventional TFMG and the Young's modulus was lower than the conventional one.

NUMERICAL ANALYSIS OF RELATIVE RESISTIVITY FOR A HORIZONTALLY LAYERED EARTH

The method of calculating the relative resistivity, which is the ratio of the apparent resistivity to the resistivity of the upper layer, for a multiple‐layered earth is given by means of the expansion of the kernel function according to a complete system of normalized orthogonal polynomials. The method, which includes estimation of the accuracy to be expected, is illustrated by application to a three‐layer earth.