The gob side entry retaining with high water material is often used in coal mines. To study the stress evolution characteristics of surrounding rock and asymmetric support control technology of gob side entry retaining with high water material, the evolution law of stress and deformation of surrounding rock in gob side entry retaining during working face mining is studied by theoretical analysis, numerical simulation and field measurement. According to the stress variation of overlying strata during the mining process of the working face, the mechanical models before and after the basic roof fracture were established respectively. The stress and deformation of the filling body and the roof on the side of the filling body are larger, and the stress and deformation of the solid coal and the roof on the side of solid coal are smaller. The maximum stress is at 3 m away from the roadway. The first weighting step distance is 40 m and the periodic weighting step distance is 30 m. Based on the stress and deformation characteristics of the roadway surrounding, the roadway surrounding support is divided into filling bodyside, solid coal side, and middle part of roadway roof. The asymmetric support technology of "filling body+ double row hydraulic prop+ I-beam+ high-strength pretension anchor cable+ high-strength bolt" is proposed. The field engineering practice shows that the surrounding rock control effect of asymmetric support technology with high water material is good., Qiyuan Shan, Yongli Liu, Tao Li and Zhupeng Jin., and Obsahuje bibliografii
The astrogeodetic method of detailed geoid determination need astronomical observations of longitude and latitude. Together with GPS observations it may be used to vertical deflections determination. In the article the portable system for automatic determination of astrogeodetic vertical deflection components developed at AGH University of Science and Technology is described. The design, main error sources, and preliminary results of the test measurements are presented., Jacek Kudrys., and Obsahuje bibliografii
The known vertical deflection values can be utilised to increase geoid’s accuracy. One of the methods of vertical deflection components (ξ, η) determination is to compare astronomic and geodetic coordinates. Presently it is easy possible to obtain geodetic coordinates with high accuracy from GPS observation. In the article the methods of astronomical CCD observation with aid of two different optical systems are discussed. Project realisation is in preliminary stage and there are no results available yet., Jacek Kudrys., and Obsahuje bibliografické odkazy
An occurrence of tetra-coordinated aluminum in altered coal and low temperature coal ashes was investigated. As altered coal a sample from the Lazy mine (Upper Silesian Coal Basin) was tested, further, low-temperature ashes from different coals were prepared and measured. During preparation the selected coal samples were intensively air-oxidized; 27Al MAS NMR spectra of obtained ashes were then acquired and compared against those for initial coals. A reference wood ash and Al standards were used for identification of Al-forms. It was found that chemical shift at 4 ppm with coals corresponds to that for triaquo-hydroxo-diphenoxido-aluminum(III) complex (THDA), further, the shift at 72 ppm with altered coal and resulting ashes agrees with that for Al tetra-coordinated with oxygen. So, in the presence of coal organics the tetra-coordinated Al is formed under low temperature conditions, because during low temperature ashing the THDA complex is transformed to Al tetra-coordinated with oxygen only at 350 °C. A similar process occurred in the case of oxidation of coal substance under low temperature conditions in the nature at temperatures below 150 °C., Pavel Straka., and Obsahuje bibliografii
The parameters determine waves energy in shallow water zone that pronounces the crucial influence on abrasion of both natural and artificially paved banks. The effort to re-development of the relations was found as absolutely necessary for waves energy calculations. Substantial benefit of the work is found not only in enabling the use of computers while avoiding time-consuming and difficult application of diagrams, but namely in recent recognition that the calculation results showed a risk of underestimate the real impact of wind-induced waves. In some cases, the calculations respecting the above standard produce lower values of waves height and time-period and thus also lower values of wave energy., Tamara Spanilá and Karel Jahoda., and Obsahuje bibliografické odkazy
This paper reports the possibilities of using FTIR spectroscopy and simultaneous thermogravimetry and differential thermal analysis for examination of the structural order of four Czech kaolinite samples (Jimlikov, Sedlec, Olomucany and Unanov deposits) and one kaolinite standard KGa-1b from Georgia deposit obtained from the Source Clays Repository of The Clay Minerals Society (USA). FTIR spectroscopy was used for the classification of the degree of structural order of kaolinite samples by empirical (IR-E) and numerical (IR-N) classification. Differential thermal analysis was used for the determination of the kaolinite disorder degree according to decomposition peak temperature obtained from DTA curves. The resulting trend of decrease in orderliness is: KGA-1b (with the best orderliness) > Jimlikov > Sedlec > Olomucany > Unanov (with the worst orderliness)., Lenka Vaculíková, Eva Plevová, Silvie Vallová and Ivan Koutník., and Obsahuje bibliografii
The character of soil cover in anthropogenically affected areas was determined on the basis of soil morphology, particle size distribution, soil chemical properties, soil organic matter properties and mineralogy of clay fraction. The degree of anthropogenic influence was variable in the individual soil profiles. This is probably the first time that data on hot-wate rextractable carbon distribution in soil profile were obtained from the territory of Prague., Anna Žigová, Martin Šťastný, Jana Krejčová and Pavel Hájek., and Obsahuje bibliografické odkazy
Catalytic test reaction of methylbutynol (MBOH) conversion was applied to investigation of natural clays and non-clay minerals from Jordanian (bentonite, kaolinite, diatomite, zeolit e) and Russian (palygorskite, kaolinite, hydromica) deposits as well as H-ZSM-5. Palygorskite and kaolinite containing samples have shown the highest catalytic activity. Conversionove r Jordanian clay minerals decreased in the order: zeolite > bentonite > red kaolinite > white kaolinite > diatomite that agreed to change of acidity, surface area of samples. Sufficient deactivation was observed for H-ZSM-5, kaolinite and hydromica due to adsorption of secondary product in micropores of raw minerals. Products of both acidic and basic pathways of test reaction were formed indicating the presence of acid and basic sites on clays surface, apart from acidic catalyst H-ZSM-5. Theyield ratio of acidic to basic products was above the unity for zeolite, bentonite, red kaolinite, and palygorskite; equal to unity for diatomite and hydromica, and less then unity for white kaolinite. It was observed for kaolinite containing sample that high activation temperature increased conversion of MBOH owing to fo rmation of additional basic sites as a result of mineral dehydroxylation. Rise of montmorillonite content from 30 to 80 % provided 91-97 % of MBOH conversion., Lyudmila Novikova, Larisa Belchinskaya, Frank Roessner and Murad Alsawalha., and Obsahuje bibliografické odkazy
Magnetotelluric (MT) and audio-magnetotelluric (AMT) methods were applied to clarify the deep geological structure in a coal-mining area in Kushiro, southeastern Hokkaido, Japan. These methods are effective in surveying to deep. Onedimensional inversion was applied to the measurement data obtained in the MT and AMT surveys to estimate the resistivity distributions in the study area. In addition, the one-dimensional inversion method was improved to obtain accurate results by including a smoothing factor and Akaike’s Bayesian information criterion. The inversion method revealed that the lowresistivity zones at depths between 100 and 120 m below sea level correspond with the Yubetsu coal-bearing formation and clay layer, and the thickness of Cretaceous strata was estimated to be more than 4000 m. Finally, the dip of the Osotsunai fault was estimated., Hisafumi Asaue, Misahito Sasahara, Toru Yoshinaga, Yuzo Obara, Kagemi Ushida and Hiroyuki Matsumoto., and Obsahuje bibliografii