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Made available in DSpace on 2022-04-28T19:45:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 During its 13 years of non-continuous operation, the Osamu Utsumi Mine has generated serious environmental impacts. This mining complex is now attempting to decommission this uranium mine to reduce its environmental liabilities. As part of a hydrogeological analysis of the old Osamu Utsumi Mine pit area, a geophysical investigation was carried out along each front of the mine pit using electrical resistivity tomography and a dipole–dipole array. The lithology described in each front, the physical access, and data from monitoring wells also contributed to the geophysical interpretation and, hence, the hydrogeological analysis. The field results and geochemical data from monitoring wells enabled us to distinguish areas where water was flowing through fractures in the massif and areas with more acidic water, with electrical resistivity values less than 15 Ω m. Geosciences and Exact Sciences Institute (IGCE) São Paulo State University (UNESP, 24-A Ave, 1515, Bela Vista Federal University of Paraná (UFPR), XV de Novembro Str, 1299, Downtown Geosciences and Exact Sciences Institute (IGCE) São Paulo State University (UNESP, 24-A Ave, 1515, Bela Vista

This study investigated the dynamic displacement and dissolution of $$\hbox {CO}_{2}$$ in porous media at 313 K and 6/8 MPa. Gaseous ( $$\hbox {gCO}_{2}$$ ) at 6 MPa and supercritical $$\hbox {CO}_{2 }(\hbox {scCO}_{2}) $$ at 8 MPa were injected downward into a glass bead pack at different flow rates, following upwards brine injection. The processes occurring during $$\hbox {CO}_{2}$$ drainage and brine imbibition were visualized using magnetic resonance imaging. The drainage flow fronts were strongly influenced by the flow rates, resulting in different gas distributions. However, brine imbibition proceeded as a vertical compacted front due to the strong effect of gravity. Additionally, the effects of flow rate on distribution and saturation were analyzed. Then, the front movement of $$\hbox {CO}_{2}$$ dissolution was visualized along different paths after imbibition. The determined $$\hbox {CO}_{2}$$ concentrations implied that little $$\hbox {scCO}_{2}$$ dissolved in brine after imbibition. The dissolution rate was from $$10^{-8}$$ to $$10^{-9}\, \hbox {kg}\, \hbox {m}^{-3} \, \hbox {s}^{-1}$$ and from $$10^{-6}$$ to $$10^{-8}\, \hbox {kg}\, \hbox {m}^{-3} \, \hbox {s}^{-1}$$ for $$\hbox {gCO}_{2}$$ at 6 MPa and $$\hbox {scCO}_{2 }$$ at 8 MPa, respectively. The total time for the $$\hbox {scCO}_{2}$$ dissolution was short, indicating fast mass transfer between the $$\hbox {CO}_{2}$$ and brine. Injection of $$\hbox {CO}_{2}$$ under supercritical conditions resulted in a quick establishment of a steady state with high storage safety.

In this paper, based on the field test of No.S3012 working face of Shan Mushu Coal Mine in Sichuan Coal Group, monitoring the abutment pressure and gas drainage flow during the mining process, studying the change law of the abutment pressure and gas drainage flow of the coal seam, and using the numerical simulation method research on the evolution of abutment pressure and displacement of coal seam during the mining process. The results shown that: with the advance of coal mining face, the abutment pressure of coal seam can be divided into stress decreasing area, stress increasing area and original stress area, and the stress state of coal seam and the pore, crack structure and permeability of coal body are obviously changed. With the advance of the mining face, the abutment pressure in front and back of the coal mining face is the moving abutment pressure, and the coal mining face to be in the pressure relief area, the front abutment pressure peak value deep into the coal body 5–10 m, the influence scope reaches the front coal mining face to 90–100 m, this area is the stress increasing area. And the evolution law of the roof displacement of goaf is similar to the elliptical with the axial ratio changes, when the ratio is close to 1, the roof subsidence affected area is similar to the shape of “O”.

Noises generated in automobile compartments can be controlled by utilizing sound absorption and insulation materials such as polyurethane foams. Polyurethane foams are synthesized by varying polymeric methylene diphenyl diisocyanate (MDI) content for exploring the effect of high functional isocyanate on cellular and acoustic properties. The use of polymeric MDI affects polyurethane matrix modulus and drainage flow rate of the foams, and it also has strong effects on cell structure and air flow resistance (AFR). The highest sound absorption coefficient is achieved at the optimum amount of the polymeric MDI. Therefore, the optimum amount of polymeric MDI content is recommended to achieve not only high sound absorption coefficient but also high transmission loss from the polyurethane foams.

Retaining gob-side entryways and the stability of gas drainage boreholes are two essential techniques in the co-extraction of coal and gas without entry pillars (CECGWEP). However, retained entryways located in deep coal mines are hard to maintain, especially for constructing boreholes in confined spaces, owing to major deformations. Consequently, it is difficult to drill boreholes and maintain their stability, which therefore cannot guarantee the effectiveness of gas drainage. This paper presents three measures for conducting CECGWEP in deep mines on the basis of effective space in retained entryways for gas drainage. They are combinations of retaining roadways and face-lagging inclined boreholes, retaining roadways and face-advancing inclined boreholes, and retaining roadways and high return airway inclined boreholes. Several essential techniques are suggested to improve the maintenance of retained entryways and the stabilization of boreholes. For the particular cases considered in this study, two field trials have verified the latter two measures from the results obtained from the faces 1111(1) and 11112(1) in the Zhuji Mine. The results indicate that these models can effectively solve the problems in deep mines. The maximum gas drainage flow for a single hole can reach 8.1 m3/min and the effective drainage distance can be extended up to 150 m or more.

Geological storage of $$\hbox {CO}_{2}$$ in deep saline aquifers is achieved by injecting $$\hbox {CO}_{2}$$ into the aquifers and displacing the brine. Although most of the brine is displaced, some residual groundwater remains in the rock pores. We conducted experiments to investigate factors that influence how much of this residual water remains after $$\hbox {CO}_{2}$$ is injected. A rock sample was saturated with brines of two different salts. Supercritical $$\hbox {CO}_{2}$$ was injected into the samples at aquifer temperature and pressure, and the displaced water and water–gas mixtures were collected and measured. The results show that deionized water drains more completely than either of the two brines, and NaCl brine drains more completely than $$\hbox {CaCl}_{2}$$ brine. The ranking of the irreducible water saturation at the end of the experiment is deionized $$\hbox {water}

Dense observations and numerical experiments were carried out to estimate the modification of mesoscale circulation, particularly cold drainage wind. It was confirmed that nocturnal drainage flow can develop on clear calm summer day and change due to orographical forcing and the heterogeneity of heat flux induced by the discontinuity of land-use. The temperature of nocturnal drainage flow at Sungji Valley, Busan Korea, tended to increase as it passed over the urban surface due to anthropogenic heat. The increase in temperature reached 2.9 K at night. The roughness associated with the exchange of momentum flux alone and the pass of nocturnal drainage flow is important for modifying the characteristics of flow Numerical simulations carried out under various surface conditions showed good agreement with the observations. Urban heat fluxes from the surface during the day are fundamental causes of the changes in the urban mesoscale circulation. In addition, the impact of a discontinuity of surface heat flux on mesoscale flow modification tends to be greater at night than during the day because the direction of urban surface heat fluxes at night is different from that in rural areas. In addition, the criterion to estimate the increase in temperature nocturnal drainage flow was also proposed, and provided results that generally agreed with the numerical results.

The subsurface total drainagequantity is one of the most importantindicators for the drainage policy of watermanagement. The methods of estimationof the subsurface total drainage quantityunder unsteady state drainage flow maybe different in consideration of the timeduration of the process and in relation tothe type, quality and quantity of the data used.

The variations of Σθ and ΣΦ in the drainage flow in the Brush Creek valley of western Colorado are investigated using data from Doppler acoustic sodars and instrumented towers. The data were obtained on two experimental nights during the 1984 ASCOT field study. There is good agreement between the Σ variations derived from low-level observations of the sodars and those derived from the towers located throughout the valley. The observed hourly average Σθ and ΣΦ in the nocturnal drainage flow are about 20 ° to 25 ° and 5 °, respectively; these values are much larger than those generally observed over flat terrain during nighttime stable conditions. After sunrise (about 0600 MST), as the valley warms and the flow direction changes to up-valley, these parameters increase sharply to their peak values at about 0800 MST and then decrease to their normal daytime values after about two hours.

1. The experience of constructing watertight film facings on the first stage of the Great Stavropol Canal showed the expediency of their use on large canals for repair works. 2. On-site observations confirmed the high seepage-control effectiveness of film facings on damaged stretches of the canal. The effect of the repair measures were expressed in a reduction of the specific volume of drainage flow within 17–30%. 3. The length of the reconstructed stretch when performing works under the protection of temporary cofferdams should be set from 100 to 500 m. With a greater length of the section, repair costs increase, the draining process is complicated, and the fulfillment of works in the time alloted for repair is hampered.

This paper presents an analysis of nocturnal drainage flows in a mountainous coastal environment where the elevation of the terrain is comparable with the elevation of the marine temperature inversion. The analysis traces the initiation, evolution, and breakup of the drainage flow using acoustic sounder facsimile data and tethered sonde measurements of wind and temperature. Conditions addressed include (1) opposing seabreeze flow ranging from 2 to 8m s-1, (2) aiding flow, and (3) large-scale and drainage-induced subsidence. The effect of deep marine temperature inversions pervades the observations, as seen in deeper, more stratified echo layers, weaker drainage, and delayed destruction of the inversion in the morning.