THE EFFECT OF TEMPERATURE OF ROCKS ON MICROCLIMATIC CONDITIONS IN LONG GATE ROADS AND GALLERIES IN COAL MINES

2014 ◽  
Vol 59 (1) ◽  
pp. 189-216 ◽  
Author(s):  
Janusz Cygankiewicz ◽  
Józef Knechtel
Keyword(s):  
Rock Mass ◽  
Coal Extraction ◽  
Effect Of Temperature ◽  
Coal Oxidation ◽  
Temperature Changes ◽  
Air Stream ◽  
Finite Differences Method ◽  
Microclimatic Conditions ◽  
Rock Mass Fracturing

Abstract The aim of this study was to examine the effect of the temperature of surrounding rocks on enthalpy and temperature of air flowing along several model mine workings. Long workings surrounded by non- -coal rocks as well longwall gates surrounded by coal were taken into consideration. Computer-aided simulation methods were used during the study. At greater depths the amount of moisture transferred into a mine working from the rock mass is two orders of magnitude smaller than the moisture that comes from external (technological) sources, mainly from coal extraction-related processes, therefore in the equation describing temperature changes only the terms representing the flux of heat from rocks were included. The model workings, for calculation purposes, were divided into sections, 50 m in length each. For each of the sections temperature of its ribs and temperature and stream of enthalpy of air flowing along it were calculated with the use of the finite differences method. For workings surrounded by non-coal rocks two variant calculations were carried out, namely with or without technological sources of heat. For coal surrounded workings (longwall gates) a new method for determination of heat from coal oxidation was developed, based on the findings by Cygankiewicz J. (2012a, 2012b). Using the results of a study by J.J. Drzewiecki and Smolka (1994), the effects of rock mass fracturing on transfer of heat into the air stream flowing along a working were taken into account.

TDR technique for estimating the intensity of effective non rainfall

2014 ◽  
Vol 28 (1) ◽  
pp. 23-37 ◽  
Author(s):  
Grzegorz Janik ◽  
Wojciech Skierucha ◽  
Marek Błaś ◽  
Mieczysław Sobik ◽  
Małgorzata Albert ◽  
...  
Keyword(s):  
Water Flux ◽  
Temperature Drop ◽  
Soil Surface ◽  
Temperature Correction ◽  
Effect Of Temperature ◽  
Temperature Changes ◽  
Diurnal Dynamics ◽  
Moisture Contents ◽  
Diurnal Distribution

Abstract The objective of this paper is to present a method for determining diurnal distribution of the intensity of effective non rainfall water flux. It was found that the application of TDR technique for the determination of diurnal dynamics of effective non rainfall water flux requires temperature correction of sensed volumetric moisture contents. Without temperature correction the error of estimated non rainfall water flux can be as much as 26%. In addition, the effect of temperature changes on the soil surface was determined in 0.5, 1, 2, 3, 4, and 5 hours periods. It was found that the intensity of effective non rainfall water flux was determined to the greatest extent by the rate of temperature drop during the period of 3 h preceding the non rainfall water flux determination. The agreement of non rainfall water flux calculated with the method proposed and that obtained by the collector was better for dew than for hoarfrost periods.

Evolution of Microclimatic Conditions in Paskov Mine / Ewolucja Warunków Mikroklimatycznych W Kopalni Paskov

2012 ◽  
Vol 57 (4) ◽  
pp. 1045-1055
Author(s):  
Pavel Zapletal ◽  
Pavel Prokop ◽  
Vítězslav Košňovský
Keyword(s):  
Coal Mining ◽  
Mining Activity ◽  
Mining Engineering ◽  
Special Program ◽  
Main Subject ◽  
Coal Basin ◽  
Research Activities ◽  
Microclimatic Conditions ◽  
Technical University

Abstract The main subject of this paper focuses on scientific and research activities conducted in the Institute of Mining Engineering and Safety of the VŠB-Technical University of Ostrava. Cooperation between the VŠB-Technical University of Ostrava and OKD A.S., the only representative of coal mining in the Ostrava-Karviná coal basin, has recently begun to develop again. This paper describes an example discussed in a certain study, which has been undertaken for the Paskov mine, OKD a.s., dealing specifically with the evolution of microclimate parameters in mines that depend on the progress of mining activity at deeper levels over a period of several years. To this end, a special program, aimed at determination of the necessary refrigerating capacity, was established at the VŠB-Technical University of Ostrava.

Consideration of the temperature factor of atmospheric air when determining standard consumption of fuel and energy resources for train traction

2018 ◽  
Vol 77 (6) ◽  
pp. 375-381
Author(s):  
K. M. Popov
Keyword(s):  
Statistical Processing ◽  
Specific Consumption ◽  
Energy Resources ◽  
Effect Of Temperature ◽  
Influence Coefficient ◽  
Specific Work ◽  
Specific Flow ◽  
Temperature Changes ◽  
Work Area ◽  
Physical Laws

Abstract. Influence of air temperature on the consumption of fuel and energy resources (FER) on train traction is due to a number of physical laws. The extent of this effect is specified in the Rules for Traction Settlement (RTS). At the same time, when rationing FER consumption for train traction, a specialized methodical base is used, which involves a different approach to accounting for the effect of temperature on FER consumption for train traction. At the same time in different documents of this base, the effects of low temperature on the absolute and specific consumption of fuel and energy resources on train traction are taken into account in a different way, which is due to the lack of consensus among specialists on the way this factor is taken into account. Specialists of JSC “VNIIZhT” carried out an analysis of a significant amount of driver’s routes data, results of which showed that the dependence of the specific flow rate on temperature, on the basis of which the corresponding influence coefficient is determined, needs to be periodically updated. In addition, when technically standardizing the consumption of fuel and energy resources (for the locomotive crew work site), the temperature effect coefficients need to be calculated for a specific work area and direction of motion on it, while using the average network coefficient values will lead to errors. When calculating additional flow of fuel and energy from the effect of temperature for electric multiple units (EMU), the equations of regression dependencies should be used, obtained by statistical processing of data on temperature changes and specific consumption of fuel and energy resources for EMU and determined for each series of EMU when working on a particular suburban area.

Contribution to the determination of relative increment of internal energy at low deformation of cross-linked rubber

1980 ◽  
Vol 45 (8) ◽  
pp. 2315-2318 ◽  
Author(s):  
Vladimír Pollák ◽  
Andrej Romanov
Keyword(s):  
Internal Energy ◽  
Vinyl Acetate ◽  
Temperature Changes ◽  
Relative Increment ◽  
Poly Ethylene ◽  
Small Deformations

The relative charge of the internal energy, fU/f, during deformation of cross-linked elastomers, poly(ethylene-co-propylene) and poly(ethylene-co-vinyl acetate), was determined at various temperatures. Anomalies in the dependence of fU/f on relative dilatation in the region of small deformations ( 35%) are to a large extent besides other factors due to the sensibility of the formula used to calculate fU/f to temperature changes.

Flow Behaviors of High Acyl Gellan Aqueous Solutions as Affected by Temperature, and Calcium and Gellan Concentrations

2008 ◽  
Vol 4 (5) ◽  
Author(s):  
Yiqun Huang ◽  
Pawan Singh Takhar ◽  
Juming Tang ◽  
Barry G Swanson
Keyword(s):  
Shear Rate ◽  
Aqueous Solutions ◽  
Apparent Viscosity ◽  
Flow Resistance ◽  
Effect Of Temperature ◽  
Temperature Changes ◽  
Influence Of Temperature ◽  
Rheological Behaviors ◽  
Low Concentrations ◽  
Influence Of Temperature On

Rheological behaviors of high acyl (HA) gellan are not well understood partially because of its relatively late commercialization compared to low acyl gellan. The objective of this study was to investigate the effect of temperature (5-30 °C), calcium (0, 1 and 10 mM) and gellan concentrations (0.0044-0.1000% w/v) on the flow behaviors of high acyl gellan aqueous solutions using rheological tests. Gellan solutions with 0 or 1 mM added Ca++ exhibited shear thinning behavior at gellan concentrations above 0.0125%. The influence of temperature on apparent viscosity (shear rate, 100 s-1) of gellan solutions can be described with an Arrhenius relationship. The apparent viscosity of gellan solution at low concentrations was more sensitive to temperature changes. The addition of Ca++ led to a decrease in flow resistance for a dilute gellan solution (<0.0125%), but an increased resistance for a relatively concentrated gellan solution (>0.0125%).

Cortical reaction as an egg quality indicator in artificial reproduction of pikeperch, Sander lucioperca

2012 ◽  
Vol 24 (6) ◽  
pp. 843 ◽  
Author(s):  
Daniel Żarski ◽  
Sławomir Krejszeff ◽  
Katarzyna Palińska ◽  
Katarzyna Targońska ◽  
Krzysztof Kupren ◽  
...  
Keyword(s):  
Quality Evaluation ◽  
Egg Quality ◽  
Effect Of Temperature ◽  
Artificial Reproduction ◽  
Female Fish ◽  
Sander Lucioperca ◽  
Embryo Survival ◽  
Hormonal Stimulation ◽  
Cortical Reaction

The aim of this study was to investigate the process of the cortical reaction in eggs of pikeperch, Sander lucioperca (L.), as well as the application of microscopic assessment of this process in egg quality evaluation. The analysis was carried out with eggs obtained from 10 females by artificial reproduction, in which hormonal stimulation with hCG was applied. Subsequently, each sample of eggs (separately from each female fish) was analysed. The analysis included observation of the cortical reaction and the process of egg swelling, and determination of the effect of temperature (12, 14 and 16°C) and the presence of spermatozoa on the cortical reaction. The results indicate that the cortical reaction in pikeperch eggs is quite violent, resulting in visible deformation of eggs between 3 and 5 min after activation. No effect of temperature or the presence of spermatozoa on the cortical reaction was observed. A strong correlation was recorded for the percentage of egg deformations observed and embryo survival rate. The described method of determination of pikeperch egg quality (based on egg deformation rate between 3 and 5 min after activation) may be highly useful, both in scientific research (where high-quality eggs are required) and in hatchery practice.

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