Articles de revues : « Air-rock interaction »

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Knight, Rosemary, et Ana Abad. « Rock/water interaction in dielectric properties : Experiments with hydrophobic sandstones ». GEOPHYSICS 60, n^o 2 (mars 1995) : 431–36. http://dx.doi.org/10.1190/1.1443780.

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The dielectric constant of a partially saturated sandstone varies as a function of the level of water saturation. Experimental data indicate that rock/water interaction, at low saturations, has a large effect on the measured dielectric response. To theoretically predict the dielectric constant of the rock/water/air system, this rock/water interaction must be accounted for by including the effect of the water wetting the rock solid. Alternatively, if the rock/water interaction can be eliminated, a three‐component (dry rock, water, and air) mixing law can be used to model the dielectric behavior. In this laboratory study, a chemical treatment is used to change four water‐wet sandstones into hydrophobic sandstones. In three hydrophobic samples the rock/water interaction, seen in the data for the water‐wet samples, is eliminated and the dielectric constant of the partially saturated sandstones can be simply modeled as a dry rock/water/air system. This experimental study illustrates the importance of the chemical state of the rock surfaces in determining the dielectric behavior of sandstones.

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Fan, Yong Tao, Zhi Qiang Huang, De Li Gao, Qin Li et Hai Yan Zhu. « Study on the Mechanism of the Impactor-Bit-Rock Interaction Using 3D FEM Analysis ». Advanced Materials Research 189-193 (février 2011) : 2280–84. http://dx.doi.org/10.4028/www.scientific.net/amr.189-193.2280.

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To reveal the mechanism of the impactor-bit-rock interaction in geophysical prospecting percussion drilling, considering the coupling effect of the static pressure, impact force and rotary cutting, constructing the physical model of the impactor-bit-rock interaction, and using the finite element methods (FEM), three-dimensional (3D) model of the impactor-bit-rock interaction is established. Using the finite element analysis software (ANSYS/LS-DYNA), the 3D FEM analysis of the impactor-bit-rock interaction is carried out when compressed air pressure is 0.8 MPa, 0.9 MPa, 1.0 MPa, 1.1 MPa and 1.2 MPa respectively. The results show that: the energy transmission efficiency when piston impacts bit under different air pressure is not high and it should be improved further, bit can not fragment rock until it is impacted by piston, it is found that the best air pressure is 1.0 MPa when the impactor and bit are used to drill granite according to the volume of the fragmented rock and the depth of the crater, the speed and displacement on the radial direction of the piston which should be reduce even eliminate are very harmful. The results are further useful to extend the applications of the geophysical prospecting impactor and hammer bit.

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Deng, Huafeng, Yinchai Zhang, Yongyan Zhi, Lingling Duan, Jianlin Li, Xushu Sun et Xiaoliang Xu. « Sandstone Dynamical Characteristics Influenced by Water-Rock Interaction of Bank Slope ». Advances in Civil Engineering 2019 (19 mars 2019) : 1–11. http://dx.doi.org/10.1155/2019/3279586.

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During the long-term reservoir operation, the seismic capability and dynamic response characteristics of the bank slope are of great importance to its safety evaluation content. Aimed at typical bank slopes, considering reservoir water level fluctuation and soaking-air drying cyclic interaction, an experiment has been designed and conducted. In addition, the cyclic loading test with different stress amplitudes was carried out in different water-rock cycles. The laboratory results indicate that (1) during the immersion-air dry circulation process, the damping ratio and damping coefficient of sandstone gradually increased while the dynamic elastic modulus decreased. It is obvious that the dynamic elastic modulus of sandstone decreases dramatically during the immersion-air dry circulation process, especially in the first six periods. Also, its variation curve fits with the logarithmic curve. (2) When the cyclic load stress amplitude increases from 10 MPa to 35 MPa, the damping ratio and coefficient of the rock sample gradually decreased while dynamic elastic modulus increased. each dynamic parameter shows a more obvious variation trend when the stress amplitude is lower than 25 MPa. (3) During the water-rock interaction process, the closely knit microstructure of rock gradually becomes loose and porous, which resulted in the degradation of macroscopic physical and mechanical properties of sandstone. (4) In the analysis of the seismic response of the bank slope, the actual water-rock interaction process and the seismic level of the bank slope should be more considered. To find out further accurate reflection in the earthquake resistance and dynamic response of the bank slope, it is necessary to select the reasonable dynamic parameter to carry out seismic research.

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Dongarr�, G., et S. Francofonte. « Quality of rainwater : A geochemical process of water-air-rock-life interaction ». Environmental Geology 25, n^o 3 (avril 1995) : 149–55. http://dx.doi.org/10.1007/bf00768544.

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Zhang, Yinchai, Huafeng Deng, Wei Wang, Lingling Duan, Yongyan Zhi et Jianlin Li. « The Dynamic Response Law of Bank Slope under Water-Rock Interaction ». Advances in Civil Engineering 2018 (7 août 2018) : 1–10. http://dx.doi.org/10.1155/2018/1306575.

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During the reservoir operation process, the long-term security and stability of the bank slope is affected by dynamic response characteristics of its seismic action directly. Aimed at the typical bank slope existing in the actual reservoir environment, an experiment considering reservoir water level fluctuation and soaking-air-drying cyclic water-rock interaction has been designed and conducted while the cyclic loading test was performed in different water-rock cycles. Research results indicate the following: Firstly, in the process of water-rock interaction, the dynamic characteristics of sandstone show evident degradation trend, with the increase of the damping ratio and Poisson’s ratio and decrease of dynamic elastic modulus, and the former six water-rock cycle degradation effects are particularly obvious. Secondly, the numerical analog computation analysis of dynamic response in typical bank slope shows that as the water-rock interaction period is increased, the dynamic response of the slope hydro-fluctuation belt zone increases gradually, while the other parts weaken. Thirdly, under the long-term water-rock interaction process, the hydro-fluctuation belt zone gradually becomes a “soft layer” which is sensitive to the earthquake effect and dynamic response, resulting in a direct influence on long-term seismic performance of the bank slope. Therefore, it is necessary to make better protection for the bank slope hydro-fluctuation belt zone.

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Huang, Jin, Qingxiang Shui, Daguo Wang, Yuhao Shi, Xiaosheng Pu, Wenzhe Wang et Xuesong Mao. « Study on Temperature Distribution Law of Tunnel Portal Section in Cold Region Considering Fluid–Structure Interaction ». Sustainability 15, n^o 19 (6 octobre 2023) : 14524. http://dx.doi.org/10.3390/su151914524.

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The design of tunnels in cold regions contributes greatly to the feasibility and sustainability of highways. Based on the heat transfer mechanism of the tunnel surrounding rock–lining–air, this paper uses FEPG software to carry out secondary excavation and development, then the air heat convection calculation model is established by using a three-dimensional extension of the characteristic-based operator-splitting (CBOS) finite-element method and the explicit characteristic–Galerkin method. By coupling with the heat conduction model of the tunnel lining and surrounding rock, the heat conduction-thermal convection fluid–structure interaction finite-element calculation model of tunnels in cold regions is established. Relying on the Qinghai Hekashan tunnel project, the temperature field of the tunnel portal section is calculated and studied by employing the fluid–structure interaction finite-element model and then compared with the field monitoring results. It is found that the calculated values are basically consistent with the measured values over time, which proves the reliability of the model. The calculation results are threefold: (1) The temperature of the air, lining, and surrounding rock in the tunnel changes sinusoidally with the ambient temperature. (2) The temperature of each layer gradually lags behind, and the temperature variation amplitude of the extreme value of the layer temperature gradually decreases with the increase in the radial distance of the lining. (3) In the vicinity of the tunnel entrance, the lining temperature of each layer remains unchanged, and the temperature gradually decreases or increases with the increase in the depth. The model can be used to study and analyze the temperature field distribution law of the lining and surrounding rock under different boundary conditions, and then provide a calculation model with both research and practical value for the study of the temperature distribution law of tunnels in cold regions in the future.

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Yuan, Wenhua, Ke Hong, Run Liu, Lianjie Ji et Long Meng. « Numerical Simulation of Coupling Support for High-Stress Fractured Soft Rock Roadway in Deep Mine ». Advances in Civil Engineering 2022 (17 mai 2022) : 1–10. http://dx.doi.org/10.1155/2022/7221168.

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Aiming at the difficulties during the support of high-stress fractured soft rock roadway in deep mine, a comprehensive surrounding rock management method of bolt-net-cable-grout coupling support is proposed and the mechanism of interaction between coupling support and surrounding rock is analyzed by numerical simulation. The effectiveness of the coupling support is proved by an application in the east wing return-air roadway in the Qingdong Coal Mine of Huaibei Mining Group. The results show that the surrounding rock plastic zone near the sidewall and floor of high-stress fractured soft rock roadway is larger than that near the roadway roof, and its distribution range can be reduced by using the coupling support. And, the coupling support can improve the reliability of roadway support and the stability of surrounding rock by reducing the axial stress of anchor bolts, the stress concentration of surrounding rock caused by anchor bolt, the roadway surface displacement, and deep displacement of surrounding rock.

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Li, Erqiang, Yanqing Wei, Zhanyang Chen, Paul Archbold et Brian Mullarney. « Experimental Study on Tensile Characteristics of Layered Carbonaceous Slate Subject to Water–Rock Interaction and Weathering ». Sustainability 15, n^o 1 (3 janvier 2023) : 885. http://dx.doi.org/10.3390/su15010885.

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The transverse isotropy of rock masses formed by sedimentation is a common stratum environment in engineering, and the physical–mechanical properties can degrade due to water–rock interaction (WRI) and natural weathering, which potentially lead to the instability or collapse of tunneling, slopes and mining. Taking the carbonaceous slate of the Muzhailing tunnel as the research object, two types of specimens, which include oven-drying (instant drying in oven after fabrication) and natural air-drying (static weathering for 60 days after fabrication) were prepared, respectively, after which Brazilian tests were carried out and the tensile properties were analyzed under the two conditions. The experimental results showed that the two kinds of carbonaceous slate all show brittle failure, but the mechanical response such as failure displacement and peak load is obviously different. The tensile strength of the specimens is significantly all affected by the bedding, while the cleavage failure patterns of the two kinds are affected to different degrees. The softening coefficient of the natural air-drying specimen is 0.11–0.13, which implies that WRI and natural weathering play a vital role in the course of rock failure but have little influence on the transverse isotropy tensile property of bedding. Moreover, the mechanisms of specimen failure subject to WRI and 60 days’ weathering were explained by the SEM technique, which analyzed the micro-components and observes the process of specimen deterioration due to physicochemical reaction, the gradual development of cracks and erosion by weathering.

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FEINBURG, GRIGORY, et KONSTANTIN CHERNY. « PHYSICAL PROPERTIES OF SALT ROCKS, WHICH ARE FORMING SPECIFIC PARAMETERS OF AIR ENVIRONMENT ». News of the Tula state university. Sciences of Earth 1, n^o 1 (2023) : 67–80. http://dx.doi.org/10.46689/2218-5194-2023-1-1-67-80.

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The article discusses the main physical and chemical properties of salt rocks - alkali metal chlorides of sodium, potassium, magnesium - halite, sylvinite, carnallite, which form the specific parameters of the air environment of rock-salt and potash mines, including underground speleohospitals, as well as special salt rooms - "salt caves" or speleoclimatic chambers used for therapeutic and recreational purposes. The data of long-term field observations by the authors for slow current (for visual observation and instrumental fixation) natural phenomena - the interfacial interaction of moist air with the polymineral salt surface of natural rocks are presented.

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Wan, Fa, et Zhong-Ming Jiang. « Seepage and Heat Transfer Characteristics of Gas Leakage under the Condition of CAES Air Reservoir Cracking ». Geofluids 2021 (27 juillet 2021) : 1–18. http://dx.doi.org/10.1155/2021/5182378.

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The contradiction between supply and demand of energy leads to more and more attention on the large-scale energy storage technology; Compressed Air Energy Storage (CAES) technology is a new energy storage technology that is widely concerned in the world. The research of coupled heat transfer and seepage in fractured surrounding rocks is the necessary basis to evaluate the operation safety and effectiveness of CAES. Current studies point to the possibility of cracking in concrete liner seals, but the thermodynamic processes and leakage characteristics of compressed air in the presence of cracking and the heat transfer characteristics of seepage have not been addressed and reported. In order to investigate the leakage, the gas seepage and heat transfer law in fractured rock when the hard rock CAES gas reservoir seal cracks, the COMSOL fracture Darcy module, and the non-Darcy Forchheimer model are used as the constitutive seepage. The global ODE is used to calculate the thermodynamic process of compressed air in gas storage with coupled seepage and heat transfer process. The pressure and temperature of compressed air are obtained as the unsteady boundary of the seepage heat transfer model. A program for calculating the seepage and heat transfer characteristics of fractured surrounding rock in the CAES gas reservoir is established. On this basis, with the proposed Suichang CAES cavern as the background, the seepage and heat transfer characteristics of the fractured surrounding rock of the gas storage are studied. The results showed that when there are fewer cracks in the lining and surrounding rock of the air reservoir, the air pressure decreases due to a small amount of air leakage after 30 operation cycles, and the leakage rate of each cycle is 0.7% of the gas storage capacity, but it still meets the engineering requirements. If the plant is operating under these conditions, the charging rate will need to be increased by 1.2 kg/s per cycle charging stage. In the discharging and power generation phase, the high-pressure air that previously percolated into the rock mass cracks could flow back into the air storage through the lining cracks. Therefore, it is incorrect and unreliable to consider the gas which flows out from the inner surface of the lining as unusable. When the lining crack width is less than 0.3 mm, the seepage flow is Darcy flow and the non-Darcy effect can be ignored; when the lining crack width is greater than 0.5 mm, the non-Darcy effect of seepage cannot be ignored. The gas velocity in the surrounding rock fracture medium is on the order of 0.01 m/s with an influence range of over 100 m, and the gas velocity in the pore medium is on the order of 10-6 m/s with an influence range of 50 m. The findings of this study contribute to a better understanding of the interaction between the thermodynamic properties of compressed air and the seepage heat transfer process in compressed air storage underground reservoirs, as well as the gas leakage process in the event of liner seal cracking.

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Ďuriš, Lukáš, Josef Aldorf et Karel Vojtasík. « Final Lining Behaviour in Extremely Low Temperatures / Chování Definitivního Ostění Při Extrémně Nízkých Teplotách ». Transactions of the VŠB – Technical University of Ostrava, Civil Engineering Series 12, n^o 2 (1 décembre 2012) : 32–40. http://dx.doi.org/10.2478/v10160-012-0015-5.

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Abstract Design of a tunnel lining is complex task. The tunnel lining structure works in close interaction with the surrounding rock mass. The value of the load depends on geotechnical circumstances, primary lining, shape and size of opening, construction technology and as well on the temperature distribution in a lining that is determined by climatic conditions. The article deals with the temperatures in the tunnel lining that are brought about by air temperature changes in tunnel space and a constant temperature inside the rock mass. This problem is solved making use of temperature records in tunnel, on the inner and outer surface of the tunnel lining and in rock mass measured at a motorway Tunnel Klimkovice. These records are analyzed and submit to FE model of the tunnel lining so that the lining temperature state is converted for a lining stress state.

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Chee, Sheau Chien, Belladonna Maulianda Hidayat, Dzeti Farhah Mohshim, Zahidah Md Zain, Ivy Ching Hsia Chai, Norazleenawati Borhan, Hasnol Hady Ismail et Matt Adam. « Evaluation of anionic and non-ionic surfactant performance for Montney shale gas hydraulic fracturing fluids ». Journal of Petroleum Exploration and Production Technology 11, n^o 4 (avril 2021) : 1973–91. http://dx.doi.org/10.1007/s13202-021-01143-z.

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AbstractHydraulic fracturing is often used in unconventional shale reservoirs, and 50%–95% of the injected hydraulic fracturing fluid remains in the formation due to the capillary effect. This phenomenon has been observed in the Montney shale formation, Canada, where the flowback water recovery is generally less than 25%. Surfactant is one of the hydraulic fracturing fluid additives for reducing surface tension and capillary forces to facilitate water flowback recovery. Surfactant loss due to adsorption by the reservoir rocks reduces the chemical’s efficiency, and this causes water retention in the formation and reduces water flowback recovery. The compatibility of surfactant with reservoir rock is critical to minimize surfactant adsorption on the rock surface because this diminishes the primary function of the surfactant hydraulic fracturing fluid additive and to ensure cost-effectiveness. This study evaluates surfactant efficiency to improve flowback recovery for the Montney shale formation based on IFT, surface tension, and adsorption. This study evaluates surfactant performance and performs a fluid–fluid interaction experiment and fluid-rock compatibility investigation. Several commercial surfactants are screened for low interfacial tension and surface tension. Further analysis is carried out by evaluating the fluid-rock compatibility using the static soaking test at reservoir pressure and temperature. The pre-soaking and post-soaking test fluids were analyzed for water composition, liquid–liquid interfacial tension, surface tension, and pH. Results showed that the selected surfactant is a critical determiner of the hydraulic fracturing fluid performance. SOLOTERRA 938 is an anionic surfactant that has good compatibility with Montney shale formation. Unlike other non-ionic surfactants, SOLOTERRA 938 retains the interfacial tension and surface tension after seven days of interaction with reservoir rock. The interfacial tension remained unchanged at 0.1 mN/m. The surface tension decreased from 28.4 to 27.5 mN/m with air and from 21.7 to 20.8 mN/m with hydrocarbon because surfactant behavior changes with pH change. The surfactant concentration was measured using high-pressure liquid chromatography, and the loss was 12% after seven days of interaction with the reservoir rock (from 0.1 to 0.088wt%). The adsorption calculated based on the concentration volume showed a low value of between 0.43 and 0.97 mg/g rock.

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MITRA, MALA, et D. P. BHATTACHARYYA. « ESTIMATION OF UPWARD MUON ENERGY SPECTRA IN THE EARTH INDUCED BY DIFFUSE MUON NEUTRINOS EMITTED FROM THE ATMOSPHERIC, GALACTIC AND ACTIVE GALACTIC NUCLEAR SOURCES ». International Journal of Modern Physics A 13, n^o 02 (20 janvier 1998) : 209–21. http://dx.doi.org/10.1142/s0217751x98000081.

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The energy spectra of upward muons in the Earth emitted by atmospheric, galactic and AGN diffuse muon neutrinos incident on the Earth have been estimated using the standard formulation developed by Gaisser based on charge–current interactions in rock along with the QED-based energy loss formulation. The derived primary-cosmic-nucleus–air interaction yield neutrino-induced muon spectrum in the vertical direction is in accord with the recent data available from MACRO, IMB, KAMIOKA and BAKSAN underground experiments for energies below 3 GeV. The TeV muon energy spectra initiated by atmospheric, galactic and AGN diffuse muon neutrinos of Stecker et al. and Szabo and Protheroe have also been estimated. The estimated atmospheric neutrino-induced muon fluxes at 0° and 89° above 2 TeV energy do not cross the observed upper limit detected by Meyer using the underground Frejus muon detector.

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Guo, Ruiping, Jason Martino et David Dixon. « Fully coupled thermohydraulic modelling of the sealing bulkheads and adjacent rock in a full-scale underground test ». Canadian Geotechnical Journal 42, n^o 5 (1 octobre 2005) : 1318–29. http://dx.doi.org/10.1139/t05-049.

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The Tunnel Sealing Experiment (TSX) was a two-phase international project funded by Canada, Japan, France, and the United States. The first phase was pressurizing the TSX chamber to 4 MPa to investigate the ability of clay and concrete bulkheads to reduce hydraulic flows. The second phase involved circulating heated water through the chamber to evaluate the influence of elevated temperature on the performance of the bulkheads and adjacent rock. A numerical analysis to simulate thermohydraulic evolution of the bulkheads and surrounding rock of the TSX was conducted to help in understanding the physical test process and the interaction between heat and pore pressure evolutions. The simulated rock temperature matched the measured data quite well; however the simulated bulkhead temperatures were greater than the measured temperatures. The difference may have been caused by entrapped air or formation of microchannels in the chamber sand, which would decrease the amount of heat reaching the bulkheads. The simulated thermally induced pore pressure increase in the clay bulkhead reasonably matched the measured data for the saturated portion. The difference in magnitude between simulated and measured rock pore pressures indicates that thermo hy draulic simulation should be coupled with a mechanical component when the stiffness of the media is large and hydraulic conductivity is low.Key words: numerical modelling, Tunnel Sealing Experiment, nuclear waste management, hydraulic head, thermal conduction, thermal convection.

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Yoshikawa, Akihiro, Ryutaro Goto, Chiaki I. Yasuda et Akira Asakura. « Size and sex bias in air-exposure behavior during low tide of the intertidal hermit crab Clibanarius virescens (Krauss, 1843) (Decapoda : Anomura : Diogenidae) ». Journal of Crustacean Biology 40, n^o 2 (4 janvier 2020) : 152–55. http://dx.doi.org/10.1093/jcbiol/ruz096.

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Abstract Many species of the hermit crab Clibanarius (Diogenidae) live on rocky shores of tropical and warm temperate regions. Some of these species are known to climb out from tidal pools onto rock surfaces exposed to air during low tide. The ecological significance of this behavior, however, remains unclear. We investigated the differences between air-exposed and non-air-exposed Clibanarius virescens (Krauss, 1843) in relation to their body size, sex, and infestation by three species of parasitic bopyrid isopods. Our generalized additive model (GAM) analyses showed a significant effect of the “smoothing factor” of the interaction between body size and sex for the occurrences of the “air-exposure behavior.” The presence of the ectoparasitic isopods did not affect the air-exposure behavior. Females of C. virescens showed a more distinct trend than in males, whereas air-exposure in both sexes had a peak in approximately 3.0–4.0 mm shield size (comparatively larger size in females, and middle-size in males) and decreased after this size range. Intraspecific and/or interspecific competition for shells may be intense in hermit crabs of this size range because of size overlap, and the individuals that carry suitable shells may avoid such competition by actively escaping from tide pools at low tide.

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Bergman, Douglas, Jose Bellido, Vitor de Souza, Ralph Engel, Zane Gerber, JiHyun Kim, Eric Mayotte et al. « Testing the Compatibility of the Depth of the Shower Maximum Measurements performed at Telescope Array and the Pierre Auger Observatory ». EPJ Web of Conferences 283 (2023) : 02008. http://dx.doi.org/10.1051/epjconf/202328302008.

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The Telescope Array and the Pierre Auger Observatory estimate the composition of ultra-high-energy cosmic rays by observing the distribution of depths of air-shower maxima, X max. Both experiments directly observe the longitudinal development of air showers using fluorescence telescopes with surface particle detectors used in conjunction to provide precision in determining air-shower geometry. The two experiments differ in the details of the analysis of events, so a direct comparison of X max distributions is not possible. The Auger – Telescope Array Composition Working Group presents their results from a technique to compare X max measurements from Auger with those of Telescope Array. In particular, the compatibility of the first two moments of the X max distributions of Auger with the data from the Black Rock Mesa and Long Ridge detectors of the Telescope Array is tested for energies above 1018.2 eV. Quantitative comparisons are obtained using air-shower simulations of four representative species made using the Sibyll 2.3d high-energy interaction model. These are weighted to fit the fractional composition seen in Auger data and reconstructed using the Telescope Array detector response and analysis methods.

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Kolesnyk, Valerii, Artem Pavlychenko, Olena Borysovska, Yurii Buchavyi et Daria Kulikova. « Justification of the method of dust emissions localization on mobile crushing and sorting complexes of quarries with the use of air-and-water ejectors ». E3S Web of Conferences 168 (2020) : 00029. http://dx.doi.org/10.1051/e3sconf/202016800029.

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Rock mass transloading from bunkers to conveyors or from conveyors to conveyors in quarries is accompanied by intense releases of dust into the atmosphere, which is a significant danger to the environment. The regularities of the interaction process between dust particles and droplets of a liquid (water) in polluted air flow are determined. It is established that when the pressure of compressed air is changed from 0.1 to 0.4 MPa (approximately in the range of 1 to 4 atm.), the average size of droplets decreases from 26 to 9 microns. Justification of the localization method of dust emissions into the atmosphere, arriving from the units of dust formation in crushing and sorting complexes of quarries, is done with the use of air-and-water ejectors − irrigators with highly efficient water use, sprayed with separate nozzles. Variants of air-and-water ejectors placement on dust formation sources are grounded. The choice of the optimal mode of air-and-water ejectors operation depends on the characteristic sizes of the formed dust particles, which are determined by the parameters of the crushing and sorting equipment in the quarry. Reducing dust emissions within the sanitary protection zone of the quarries prevents its dispersion in the adjacent zone.

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Zhang, Wenping. « Feasibility Analysis of Drilling with Liquid Nitrogen in High Temperature Geothermal Wells ». Academic Journal of Science and Technology 6, n^o 1 (29 mai 2023) : 119–24. http://dx.doi.org/10.54097/ajst.v6i1.8914.

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The main costs of developing geothermal processes are concentrated in the project of drilling, accounting for more than 70% of the total budget. Inspired by thermal stimulation technology，a new concept of drilling with liquid nitrogen was presented in this paper. The main objective of this paper is to investigate the effect of rapid cooling on bit-rock interaction and the feasibility of drilling with liquid nitrogen. Through the hardness test experiment results, it showed that the thermal stress caused by rapid cooling can reduce the resistance of indenter invades the rock. Then the micro-bit drilling experiment results indicated that liquid nitrogen can eliminate the thermal damage and enhance the wear resistance, which is the main factor affected the life and footage per bit in geothermal drilling. The negative effect is that liquid nitrogen increase the rock failure resistance slightly and need about 8% more mechanical specific energy compared with drilling with air, but the increase about 8% in mechanical specific energy is affordable to drilling engineers. All these results showed that drilling with liquid nitrogen is beneficial to improve the life and footage per bit, reduce non-production time and reduce drilling costs, it is a promising technology in geothermal engineering.

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Sinner, Alejandro G., et Joan Ferrer i Jané. « Rock Sanctuaries, Sacred Landscapes, and the Making of the Iberian Pantheon ». Religions 13, n^o 8 (9 août 2022) : 722. http://dx.doi.org/10.3390/rel13080722.

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Sanctuaries are common spaces of interaction between humankind and the gods. In many religious systems, mountains and other elevated topographical features are known to have formed part of these privileged spaces of communication. It is not surprising that open-air and, in many cases, rock sanctuaries are the cultic spaces par excellence among the pre-Roman peoples of the Iberian Peninsula. In this article, we offer a more nuanced picture of these architectonically humble but culturally rich sacred spaces by studying the Palaeohispanic inscriptions recorded in rock sanctuaries located in the territories of the Iberian peoples (fourth–first centuries BCE). Special attention will be paid to the corpus of inscriptions in Cerdanya (Pyrénées-Orientales and Catalonia), where more than 150 texts have so far been identified. After a brief introduction contextualizing the Rock Sanctuaries, the Iberian language, and the epigraphic habit of its speakers, the first section of our article analyses the characteristics that enable us to interpret most of these inscriptions as religious and votive formulations. The second half of the paper discusses what these inscriptions can reveal about the Iberian pantheon and how these rock sanctuaries formed a consolidated religious landscape that was to survive the Roman conquest. The reinterpretation of the Celtiberian sanctuary of Peñalba de Villastar will be fundamental to put forward the hypothesis that, while Iberian and Celtiberian places of worship and pantheons had points of contact, they were mostly dissociated from each other prior to the Roman arrival.

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Khari, Mahdy, Khairul Anuar Kassim et Payman Alimohammadi. « Response of Single and Grouped Pile Subjected to Lateral Load in Cohesionless Soil ». Applied Mechanics and Materials 773-774 (juillet 2015) : 1397–401. http://dx.doi.org/10.4028/www.scientific.net/amm.773-774.1397.

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Piles are generally required to transfer load from a superstructure through weak or compressible strata, or through water, on to stiffer and less compressible soils and rock. The pile behavior is very important in Soil-Pile interaction (as known Kinematic Interaction) so that grouped and single pile behavior differs owing to the impacts of the pile-to-pile interaction. In this research presents a series of experimental investigations carried out on single and group pile subjected to monotonic lateral loadings. The aluminum model piles were tested in the different relative densities in Johor Bahru sand. The sand samples were prepared by using the newly designed Mobile Pluviator adopted the air pluviation method. The different configurations of model pile groups for embedded length-to-diameter ratio equal to 32 into loose and dense sand spacing from 3 to 6 pile diameter (D) were conducted. The ultimate lateral load is increased 53% in increasing of s/d from 3 to 6 owing to effects of sand relative density. A ratio of s/D more than 6d is large enough to eliminate the pile-to-pile interaction and the group effects. It may be more in the loose sand.

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AFANASEV, Pavel. « Analysis of shock wave parameters at the explosive cavity wall during refraction of detonation waves through the air and water ». Sustainable Development of Mountain Territories 15, n^o 3 (30 septembre 2023) : 505–15. http://dx.doi.org/10.21177/1998-4502-2023-15-3-505-515.

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Introduction. Drilling and blasting operations are carried out in various mining and geological conditions. The pressure transmitted from the detonation wave into the rock is an important factor affecting the parameters of the borehole network. At the same time, the calculation of the parameters of shock waves in engineering practice is not accompanied by the analysis of changes in the detonation wave parameters when passing to the rock. At decomposition of the explosive inside the borehole, the movement of the detonation wave along its surface is characterized by normal and sliding incidence. At the moment of initiation, at the initial stage, the incidence of the detonation wave on the borehole surface is normal; later, when the detonation wave propagates along the surface, a sliding interaction occurs. This sliding motion is the main one, since the detonation wave front proper, which moves along the borehole, does not have a strong surface curvature. Refraction of the detonation wave is not always possible directly into the rock, since the medium near the explosive can be surrounded by an air or aquatic medium. Therefore, it is necessary to take into account possible options for the performance of drilling and blasting operations: a radial air gap and the presence of water between the explosive and the rock. As a rule, the occurrence of an air gap shows up in case of intense fracturing of the massif, the use of hoses of a smaller diameter than the drilled borehole. The presence of water between the explosive and the rock depends on the rate of water inflow into the borehole and can be also due to breaching the charging technology, when charging of the borehole under the water column is neglected. The presence of inert media, such as water and air, change the detonation pressure and the velocity of detonation products acting on the rock; therefore, it is necessary to analyze the parameters of the explosive cavity wall for various types of refraction of the detonation waves and on the basis of such analysis, substantiate your choice of the characteristics of the explosive. Research methods and materials. Assessment of the detonation wave parameters is based on the hydrodynamic theory of detonation with the calculation of the indicators of gaseous explosion products using the method proposed by L.V. Landau and K.P. Stanyukovich. Estimation of stress wave parameters in the massif is based on the solution of the Riemann problem of the breakdown of an arbitrary discontinuity when the detonation products (DP) refract into different media (Fig. 1). In the first case, the “DP – rock” is considered; in the second case, the “DP – air medium – rock” and in the third one, the “DP – aquatic medium – rock”. Discussion of research results. It was revealed: when a detonation wave is refracted through an aquatic medium into siltstone, the pressure values on the explosive cavity wall will be higher than without an iner t medium. Thus, for acoustically softer rocks, the presence of an inert medium (water) leads to an increase in pressure, and hence to an increase in the brisance of the explosion. In acoustically harder rocks, this result is not recorded. The analysis of the data obtained showed that the parameters of the detonation waves refracted into different inert media differ significantly both in pressures and in par ticle velocities in such media. Conclusive statements. 1. When a detonation wave passes into an acoustically hard medium, the values of the pressure transmission ratios increase in the presence or absence of an intermediate inert medium, and the mass velocity transmission ratios decrease. Thus, there is a redistribution of the destruction character in favour of the wave action in relation to the quasi-static one. 2. When a detonation wave is refracted through an aquatic medium, the pressure in acoustically soft rocks increases. For acoustically hard rocks, no pressure increase is recorded. 3. The highest values of the ratio of pressure transmission into the rock are achieved at the detonation velocity of EEM about 4,000-4,500 m/s. 4. The choice of an explosive for assessing the impact on the massif should be based on the estimation of the initial parameters recorded on the explosive cavity wall, since you can choose the following characteristics of impact on the massif: “hard” – wave or “soft” – quasi-static. The initial values of mass velocities can be used for assessing the collapse of the rock, and the pressure values for assessing the shear (regrinding) zones. Conclusions. 1. The article presents the results of research on estimating the parameters of shock waves on the explosive cavity wall when the sliding detonation wave is refracted into the rock. 2. It is shown that the choice of an explosive for assessing the impact on the rock mass should be based on the calculation of the initial parameters recorded on the explosive cavity wall taking into account the character of the detonation wave refraction through inert media. 3. It is ascertained that when a detonation wave is refracted through the aquatic medium in an acoustically “softer” rock (siltstone), the stresses arising on the explosive cavity wall will be higher than in the absence of an aquatic medium. Thus, in acoustically “soft” rocks, an increase in stresses is recorded due to an inert medium; for acoustically “hard” rocks, there is no increase in stress. The air medium always reduces the stress on the explosive cavity wall. Results. The results of the research can be useful for design and scientific organizations that validate the explosives used by the companies of the mineral resource complex and also for those engaged in mining operations and improvement of the blasted rock mass quality.

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Zhang, Hao, Zaiqiang Hu, Xingzhou Chen et Hongru Li. « Formation Mechanism and Stability Analysis of the Hejia Landslide ». Advances in Materials Science and Engineering 2021 (26 décembre 2021) : 1–11. http://dx.doi.org/10.1155/2021/1372621.

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The existing research data show that, after reservoir impoundment, due to the repeated rise and fall of water level and water-rock interaction, the mechanical parameters of landslide are reduced, which will have an adverse effect on the stability of landslide. Therefore, sufficient attention must be paid to the stability of slope after reservoir impoundment. Hejia landslide is the largest landslide near the bank of Miaojiaba hydropower station, and its stability plays an important role in the normal operation of the hydropower station. Through field investigation and analysis of regional geological conditions, it is concluded that Hejia landslide is a large-scale landslide, through long-term sliding-bending deformation; it is generated from the external hard rock with thick layers and sliding zone for layered soft rock; the formation mechanism of landslide is as follows: (1) high-steep and hard-soft layered slope is the slope structure condition that caused the large landslide; (2) the existence of thick soft rock belt provides material conditions for the formation of slip surface; (3) certain air conditions provide displacement space for the separation and disintegration of the sliding body, and the landslide is stable at present. Numerical analysis results show that reservoir impoundment will adversely affect the stability of landslide. In order to ensure the normal operation of power station, certain engineering measures must be taken to treat Hejia landslide. After taking measures, years of monitoring data show that the deformation of Hejia landslide tends to be stable, and the current operation is normal, indicating that the engineering treatment measures are reasonable and feasible.

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Yuningsih, Euis Tintin. « HOST ROCK AND MINERALIZED ORES GEOCHEMISTRY OF BANTARHUNI VEIN, ARINEM DEPOSIT, WEST JAVA – INDONESIA ». Bulletin of Scientific Contribution 14, n^o 3 (26 janvier 2017) : 223. http://dx.doi.org/10.24198/bsc.vol14.yr2016.art10964.

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There are closed spatial relationship between the different phases, the different metallic minerals, the precious-metals bearing minerals, the volcanic host rock and the plutonic intrusions of the Arinem vein system. Nine samples from Bantarhuni vein including four samples from quartz-sulfide vein from different stages and level, and five samples from altered host rock were analyzed geochemically by Induced Couple Plasma (ICP) and Induced Couple Plasma Mass Spectrometer (ICP-MS) to identified the geochemical characteristics of Bantarhuni vein system. The geochemical data obtained from the quartz-sulfide vein and altered host rock of the Bantarhuni vein is mostly similar to those obtained from Arinem vein samples. Some samples from the alteration zone have contents similar to the less altered Jampang Formation and andesitic Miocene and Pliocene intrusions rocks, with a little depletion and enrichment for some oxides. The abundance of ore and gangue minerals vary among each stage of mineralization of Bantarhuni vein. The REE in the Arinem and Bantarhuni veins considered to have been extracted by water/rock interaction between hydrothermal solution and country rocks. Some REE pattern of the mineralized Bantarhuni vein show irregularly pattern and this is could be due to high content of sulfide minerals in the samples, or due to analytical error during sample dissolution. The gold and silver contents in the Arinem and Bantarhuni veins vary very much and there is relatively low Au and Ag concentrations occur in samples from any alteration zone. There is no correlation found between gold and other major ore elements except for Ag. The highest content of Au is having low ΣREE. Keywords : Bantarhuni vein, Geochemical, quartz-sulfide vein, water-rock interaction. Terdapat hubungan spasial antara fase yang berbeda, mineral logam yang berbeda, mineral yang mengandung logam mulia, batuan induk (host rock) vulkanik dan intrusi plutonik dalam sistem urat Arinem. Sembilan sampel dari urat Bantarhuni yang terdiri dari empat sampel dari urat kuarsa-sulfida dari stages dan kedalaman yang berbeda, dan lima sampel dari host rock yang terubah dianalisis secara geokimia degan Induced Couple Plasma (ICP) dan Induced Couple Plasma Mass Spectrometer (ICP-MS) untuk mengidentifikasi karakteristik geokimia dari sistem urat Bantarhuni. Data analisis geokimia yang diperoleh dari urat kuarsa-sulfida dan batuan induk terubah dari urat Bantarhuni sebagian besar sama dengan yang diperoleh dari sampel urat Arinem. Beberapa sampel dari zona alterasi memiliki kandungan mirip dengan Formasi Jampang yang terubah lemah dan batuan intrusi andesit berumur Miosen dan Pliosen, dicirikan dengan sedikit pengurangan dan pengayaan untuk beberapa oksida. Kelimpahan bijih dan mineral gang bervariasi di dalam setiap tahap mineralisasi di urat Bantarhuni. REE di urat Arinem dan Bantarhuni kemungkinan diekstraksi dengan adanya interaksi air/batuan antara fluida hidrothermal dan batuan sampingnya. Beberapa pola REE dari urat Bantarhuni yang termineralisasi menunjukkan pola yang tidak teratur dan hal ini kemungkinan disebabkan oleh tingginya kandungan mineral sulfida dalam sampel, atau karena kesalahan pada saat analisis dalam pelarutan sampel. Kandungan emas dan perak dalam urat Arinem dan Bantarhuni sangat bervariasi dan konsentrasi Au dan Ag pada sampel dari setiap zona alterasi relatif rendah. Tidak ada korelasi ditemukan antara emas dan unsur bijih utama lainnya kecuali dengan Ag. Sampel dengan kandungan Au tertinggi adalah sampel yang memiliki ΣREE rendah. Kata kunci: Urat Bantarhuni, geokimia, urat kuarsa-sulfida, interaksi air-batuan.

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Charpentier, D., R. Mosser-Ruck, M. Cathelineau et D. Guillaume. « Oxidation of mudstone in a tunnel (Tournemire, France) : consequences for the mineralogy and crystal chemistry of clay minerals ». Clay Minerals 39, n^o 2 (juin 2004) : 135–49. http://dx.doi.org/10.1180/0009855043920126.

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AbstractThe excavation of a tunnel through a mudstone formation provides an opportunity to examine the effects of the modification of the physical and chemical environment on the rock. The mineralogical and chemical consequences of hydration-dehydration cycles and of oxidation have been evaluated in the case of the Toarcian mudstone formation at the Tournemire experimental site (France). Studies by X-ray diffraction and tansmission electron microscopy of both altered and preserved samples show that the introduction of air and condensed water causes the oxidation of pyrite and the subsequent generation of acid and sulphate-rich waters at the micron scale, in the local environment of pyrites. The fluid-clay particle interactions around the oxidized pyrites induce: (1) a statistical enrichment in Si of the I-S clay minerals; (2) an increase in the Fe(III)/Fe total ratio in some of the I-S particles; and (3) the dissolution of illite layers in mixed-layer I-S. These evolutions are consistent with the results of numerical modelling which reproduced the interaction between the clay particles and the acid water.

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Shyrin, Leonid, Rostislav Yehorchenko et Мykola Sergienko. « SPECIFICS OF DIAGNOSTICS OF TECHNICAL CONDITION OF TRANSPORT AND TECHNOLOGICAL SYSTEM “MINING GAS PIPELINE – MINE WORKING” ». Geoengineering, n^o 6 (30 novembre 2021) : 28–37. http://dx.doi.org/10.20535/2707-2096.6.2021.241823.

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The purpose of the paper is to analyze a deformation mechanism of the mine degassing pipelines to forecast their spatial changes in terms of intensification of underground mining of coal-gas seams. Methodology. The paper deals with expert assessment of the available approaches to diagnostics of technical condition of mine degassing pipelines, which are constructed within the in-seam underground mine workings with the floor rocks prone to heaving. The results of scheduled surveying measurements of technical condition of in-seam development workings have helped identify the potentially hazardous zones of rock mass deformation and indices of changes in spatial location of section degassing pipelines mounted in those mine workings. To determine the operating modes of a degassing pipeline under such operating conditions, a computer model of interaction of the elements of transport-technological system “mine gas pipeline – mine working” has been developed Findings. Diagnostics of technical conditions of the mine gas transmission lines and examination of their dismantled components have helped understand that deflections, mainly resulting in water accumulation zones, intensive corrosion of internal pipe walls, and mechanical depositions of coal and rock dust take place right within the flange connection areas. Formation of such zones is argued by health of the degassing pipeline as well as mine air inflow. Availability of internal corrosion, water accumulations, and mine air inflow decreases substantially capacity of the underground gas transmission line inclusive of qualitative characteristics of the captured methane-air mixture and efficiency of MDS on the whole. Originality. New approaches to diagnostics of technical condition of mine degassing gas pipeline in difficult mining and geological conditions of development of gas-bearing coal seams are substantiated and it is offered to consider indicators of their functioning as interacting in space and time transport-technological system "mine gas pipeline - mining". Practical implications. The operational parameters of mine degassing systems notes that the equipment performance with the least underpressure losses created by vacuum pipes requires that the degassing pipeline should have minimum hydraulic resistance of the gas transmission network. Pipeline aeration from the mine workings and water accumulations should be prevented by means of qualitative hermetic sealing of its flange connections as well as the pipeline straightness with the corresponding pitches. Consequently, the basic requirements for operating mine degassing pipelines involve their design profile, tightness of flange connections of pipes as well as operative control of the facility health.

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Nurhikmah, M. Ramli, Sufriadin et A. Saputra. « Water Chemical Analysis of Surface Water Runoff from Iron Ore Mine Void at Tanjung – Bone, South Sulawesi. » IOP Conference Series : Earth and Environmental Science 1272, n^o 1 (1 décembre 2023) : 012035. http://dx.doi.org/10.1088/1755-1315/1272/1/012035.

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Abstract The main problem in open-pit mining activities is the remaining mine openings as voids after mining activities end. The interaction between rock, water and air can cause dissolved rock chemical elements to cause polluted water. A study of this phenomenon was carried out in a void in the Tanjung area. An abandoned iron ore mine left a void with a depth of 13 meters. Furthermore, around the void existed two stockpiles of mined ore. Therefore, the void and the stockpiles may act as pollutant sources that can reduce surface water quality. In the rainy season, the water from the void flows out as a runoff downstream through a tributary. This study is intended to analyze the chemical concentration of runoff water from the void. Field observation was done to identify rock formation, and measured pH, turbidity, total dissolved solids (TDS), and electrical conductivity(EC) of water on site, and collected 10 water samples from the river and tributary. Field data was completed with laboratory chemical analysis for water major elements of K+, Na+, Ca2+, Mg2+, Cl−, SO4 2−, CO3 2− and HCO3. The results of the analysis of the TDS test with a minimum value of 4 mg/l and a maximum of 607 mg/l. turbidity value 0 to 21.4 NTU, pH value 2.9 to 8.2, EC value 165.6 ms/cm to 316 ms/cm. Plotting the concentration of the major elements into Trilinear Piper Diagram shows that water is as CaMgSO4 water type based on their major elements. Changes in water quality at voids, stockpiles and areas around the mine indicate that potential water pollution is generated from existing stockpiles.

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Sing, R. K., C. Sawmliana et P. Hembram. « Designing controlled blasting in the vicinity of sensitive structures in an iron mine in India : A case study ». Journal of Mining and Metallurgy A : Mining 59, n^o 1 (2023) : 1–13. http://dx.doi.org/10.5937/jmma2301001s.

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This paper presents a case study at an Indian iron ore mine where controlled blast patterns were meticulously planned after conducting a few trial blasts for conducting blasts near numerous sensitive structures. A new screening plant for the mine had to be constructed on a hilly terrain in the vicinity of many sensitive structures such as residential huts, gas stations, gas storage facilities, structures of the existing screening plant, mine water reservoirs, etc. The test blasts were conducted at selected locations of the hilly terrain with varying geometric parameters in order to understand the results of the interaction between rock and explosives in the area. The effects of blasting, i.e., ground vibration, air overpressure, rock flight, etc., were evaluated and measured. Based on the results the results of test blasting and vibration data analyses from various iron ore mines in India with similar topographic conditions, three blasting zones were distinguished: critical, semi-critical and non-critical have been defined considering the nearness and sensitiveness of different structures. For each zone, the blasting parameters were developed, i.e., load, spacing, number of holes, blast charge per delay, type of explosive, etc. Using the developed controlled blasting patterns, development work near sensitive structures progresses safely. The developed controlled blasting patterns and methods can be used as AIDS for similar work in the absence of adequate scientific evaluation results.

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Phillips, Natasha, Ian Moffat, Alex Mackay et Brian G. Jones. « The Sedimentary Context of Open-Air Archaeology : A Case Study in the Western Cape’s Doring River Valley, South Africa ». Soil Systems 7, n^o 1 (10 mars 2023) : 25. http://dx.doi.org/10.3390/soilsystems7010025.

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Despite the wealth of Late Pleistocene archaeology that exists across southern Africa’s open landscape, it is routinely neglected in favour of rock shelter (re)excavation, biasing interpretation of human–environment interaction. This is compounded by the scarcity of open-air studies that use geoarchaeological methods to investigate the history and processes involved in their formation. The open-air archaeology of the Doring River Valley is an example of this, despite nearly a decade of dedicated study and publication. Consequently, there remains a limited and untested understanding of the valley’s formation history. This paper rectifies this by providing a sedimentary context for the surface archaeology exposed across one of the Doring River Valley’s artefact-baring localities, Uitspankraal 7 (UPK7). Characterisation, particle size, mineralogical, morphometric, and geophysical analysis of UPK7′s sand mantle resulted in the identification of four artefact-bearing sedimentary units, the aeolian and pedogenic processes involved in their formation, and their proposed order of deposition. This provides a stratigraphic, taphonomic, and environmental context against which chronometric dating and an analysis of the taphonomic, spatio-temporal, and technological composition of UPK7′s surface archaeology can be compared. This work is the first vital step towards understanding the depositional and behavioural history of a landscape, irrespective of context type.

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Hammami Abidi, Jamila, Boutheina Farhat, Abdallah Ben Mammou et Naceur Oueslati. « Characterization of Recharge Mechanisms and Sources of Groundwater Salinization in Ras Jbel Coastal Aquifer (Northeast Tunisia) Using Hydrogeochemical Tools, Environmental Isotopes, GIS, and Statistics ». Journal of Chemistry 2017 (2017) : 1–20. http://dx.doi.org/10.1155/2017/8610894.

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Groundwater is among the most available water resources in Tunisia; it is a vital natural resource in arid and semiarid regions. Located in north-eastern Tunisia, the Metline-Ras Jbel-Raf Raf aquifer is a mio-plio-quaternary shallow coastal aquifer, where groundwater is the most important source of water supply. The major ion hydrochemistry and environmental isotope composition (δ18O, δ2H) were investigated to identify the recharge sources and processes that affect the groundwater salinization. The combination of hydrogeochemical, isotopic, statistical, and GIS approaches demonstrates that the salinity and the groundwater composition are largely controlled by the water-rock interaction particularly the dissolution of evaporate minerals and the ion exchange process, the return flow of the irrigation water, agricultural fertilizers, and finally saltwater intrusion which started before 1980 and which is partially mitigated by the artificial recharge since 1993. As for the stable isotope signatures, results showed that groundwater samples lay on and around the local meteoric water line LMWL; hence, this arrangement signifies that the recharge of the Ras Jbel aquifer is ensured by recent recharge from Mediterranean air masses.

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Sohn, Jung Min, Ji Woo Kim et Sang Ho Kim. « Experimental and Numerical Studies on Fluid-Structure Interaction for Underwater Drop of a Stone-Breaking Crusher ». Journal of Marine Science and Engineering 10, n^o 1 (29 décembre 2021) : 30. http://dx.doi.org/10.3390/jmse10010030.

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There are many methods for crushing seabed rock such as a using a free-falling crusher, blasting, and chemical liquid expansion. Blasting and chemical liquid expansion can lead to environmental destruction, noise pollution, and civil complaints. Therefore, a free-falling crusher is generally recommended for use. Understanding the characteristics of a crusher in water and the impact force on the ground is helpful for designing a crusher and dredge work. In this study, drop tests of 50 and 70 ton crusher models that were scaled down by 15 times were investigated. The tests were conducted in a water basin by the Research Institute of Medium and Small Shipbuilding (RIMS) in Korea. Four water depths were considered with different falling locations: water surface and air. Moreover, a numerical study on Fluid-Structure Interaction (FSI) analysis for a free-falling crusher was conducted by applying the Arbitrary Lagrangian-Eulerian (ALE) element and the Grüneisen Equation of State (EoS) to fluid models. The crusher and ground were modeled as Lagrangian elements to estimate the impact force on the ground. Before comparing the crusher model, a free-falling sphere model was used to develop FSI technologies by comparing past Computational Fluid Dynamics (CFD) and experimental results. Moreover, the recommended mesh size and fluid domain for FSI analysis are provided to achieve good results via convergence tests. Comparison between experimental and numerical methods demonstrated a similar tendency such that impact force increased at a higher depth. Certain numerical results agree with average values of experimental results; however, multiple numerical cases exhibit a moderate difference. This is because of angular rotation between the crusher and ground when the crusher hits the ground during experiments.

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Taran, Yu A., G. V. Ryabinin, B. G. Pokrovski, I. N. Nazhalova et N. A. Malik. « MINERAL WATERS OF THE AVACHINSKY DEPRESSION, KAMCHATKA ». Bulletin of Kamchatka Regional Association «Educational-Scientific Center». Earth Sciences, n^o 2(50) (30 juin 2021) : 22–39. http://dx.doi.org/10.31431/1816-5524-2021-2-50-22-39.

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Saline waters (up to 22 g/l) were tapped by deep (to 3000 m) wells at the foot of active volcanoes Avachinsky and Koryaksky, within Avachinsky depression. Temperature of waters was ~ 60°C in the western part and cold in the eastern part, closer to the Pacific coast. In this paper we present the literature and our own data on chemical and isotopic composition of these waters. The waters are of the Na-Cl type with extremely low abundances of sulfate and magnesium, high concentration of calcium and surprisingly high concentration of strontium. The waters contain about 50 ml/l of gas where methane and nitrogen are main components (~ 70 vol% and 30 vol%, respectively) and also presents H2S (~ 30 ml/l) and very low concentrations of CO2 (< 0.5 vol%). The N2/Ar ratio, as a rule, is higher than the air ratio, i.e., the non-atmospheric nitrogen presents. We discuss the possible options of the water-rock interaction, responsible for the chemical composition of waters, and offer a conceptual model of the proposed basin of mineral waters that includes the distribution of deep temperatures, the location of the possible sources of heat mineralized solutions.

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Gabbanelli, F., M. Mattioli-Belmonte, F. Giantomassi, L. Rimondini, C. Viticchi, G. Biagini, P. Torricelli, A. F. Gualtieri, I. G. Lesci et R. Giardino. « Exploring the Damage Limitation Possibilities of Mineral Fibres for Future Integrated Solutions : An in Vitro Study ». International Journal of Artificial Organs 26, n^o 1 (janvier 2003) : 73–79. http://dx.doi.org/10.1177/039139880302600111.

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Owing to their possible carcinogenic effect, asbestos and other silica derivatives have been identified as priority substances for risk reduction and prevention of pollution. Neutralisation procedures have thus become a topical research subject in many European and American countries. In the present study, silica derivatives (asbestos-containing and asbestos substitutes like slag wool, rock wool, cement asbestos) were fully impregnated with an epoxy resin according to the procedure used for the in situ impregnation with viscous polymeric media, which penetrate and cement the fibres in place and reduce the risk of their dispersion in air. Untreated and treated samples were used to investigate their in vitro interaction with a human continuous epithelial cell line (NCTC 2544 keratinocytes) and test the resin's efficiency in passivating the surface activity of the fibrous particulate. SEM and morpho-quantitative data evidenced that impregnation with the epoxy resin modifies the mineral fibres' bioactivity (reduction of cell adhesion and decreased spread/round cell ratio) and demonstrated the value of in vitro cell testing after passivation as a risk-assessment procedure. These tests could be used for the rapid determination of the level of passivation of new synthetic mineral fibrous materials subjected to resin impregnation.

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Sprunt, Eve S., Tony B. Mercer et Nizar F. Djabbarah. « Streaming potential from multiphase flow ». GEOPHYSICS 59, n^o 5 (mai 1994) : 707–11. http://dx.doi.org/10.1190/1.1443628.

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In trying to understand the affect of electrokinetics on the spontaneous potential (SP) log, the focus has generally been on the solid‐brine streaming potential. Within the accuracy of the measurements, the streaming‐potential coupling coefficient is shown to be independent of the permeability of the rock. The solid‐brine streaming potential is of much smaller magnitude than the electrostatic potentials from gas‐liquid and liquid‐liquid flow. Air bubbles were found to increase the streaming potential coupling coefficient by more than two orders of magnitude over the value for single‐phase brine flow. Thus, two‐phase gas‐liquid flow is more likely to have a significant impact on the SP log than is single phase liquid flow. Two‐phase oil‐brine flow may also produce a larger electrokinetic potential than single‐phase flow. The magnitude of the electrokinetic potential caused by oil‐brine flow will depend on the composition of the oil and the brine. Trace materials can have a major impact on the electrokinetic potential of hydrocarbons. In a system with multiphase flow, the solid‐liquid interaction is probably the smallest component of the electrokinetic potential.

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Spence, C., P. D. Blanken, J. D. Lenters et N. Hedstrom. « The Importance of Spring and Autumn Atmospheric Conditions for the Evaporation Regime of Lake Superior ». Journal of Hydrometeorology 14, n^o 5 (1 octobre 2013) : 1647–58. http://dx.doi.org/10.1175/jhm-d-12-0170.1.

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Abstract Feedbacks between ice extent and evaporation have long been suspected to be important for Lake Superior evaporation because it is during autumn and winter when latent heat fluxes are highest. Recent direct measurements of evaporation made at the Stannard Rock Lighthouse have provided new information on the physical controls on Lake Superior evaporation, in particular that evaporation can react within hours to days to a change in synoptic conditions. However, the large heat capacity of the lake creates a strong seasonal cycle of energy storage and release. There is a complex interaction among heat storage, evaporation, and ice cover that is highly dependent on atmospheric conditions in the spring and autumn “shoulder seasons.” Small changes in conditions in November and March caused by synoptic-scale events can have profound impacts on annual evaporation, the extent of ice cover, and the length of the ice-covered period. Early winter air temperatures in November and December dictate the nature of ice formation and much of the winter evaporative flux. Decreased ice cover, by itself, does not necessarily lead to enhanced annual evaporation losses. Rather, a combination of low ice cover and warm spring air temperatures, leading to an early breakup, can significantly lengthen the next evaporation season and cause greater cumulative water loss the subsequent year. The influence of individual synoptic events on annual evaporation is notable enough that the research community should ensure that their role is properly captured in numerical models to provide sound predictions of future Laurentian Great Lakes evaporation regimes.

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Sun, Faxiao, Feng Zhang, Xiaoya Ma, Zhaoqian Gong, Yicai Ji et Guangyou Fang. « Research on Ultra-Low-Frequency Communication Based on the Rotating Shutter Antenna ». Electronics 11, n^o 4 (15 février 2022) : 596. http://dx.doi.org/10.3390/electronics11040596.

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This paper proposes a rotating shutter antenna that can directly generate 2FSK signals in the ULF band and it is expected to be used as the transmitter for magnetic induction (MI) underground communication systems. The antenna was modeled using ANSYS Maxwell and the magnetic field distribution was simulated. The results show that the interaction between the high-permeability shutter and the mutual cancellation of magnets decreased the transmitting magnetic moment of the antenna. A prototype antenna was manufactured and the time and frequency properties of the measured Bz field were the same as the simulated results, while the magnitude of the measured signal was larger. The propagation characteristics of the antenna in air–soil–rock were simulated using FEKO and the results show that the signal strength was greater than 1 fT at a depth of 450 m from the antenna whose magnetic moment as 1 Am2. The relationship between different magnetic components and azimuth could be used to enhance the signal strength. The formula of the Bz field was derived using the measured magnitude versus distance and the path loss was also analyzed. Finally, the 2FSK modulation property of the antenna was verified by indoor communication experiments with a code rate of 12.5 bps in the ULF band.

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Bulat, A. F., T. V. Bunko, I. Ye Kokoulin, I. О. Yashchenko et V. V. Ponomarenko. « Simulation of dynamic phenomena in the ventilation network due to sudden gas outburst ». Geo-Technical mechanics, n^o 152 (2020) : 22–31. http://dx.doi.org/10.15407/geotm2020.152.022.

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An increase in the pace of cleaning and preparatory work, a transition to deeper horizons, a high concentration of machines and mechanisms in places where minerals are excavated and transported increase the likelihood of one of the most difficult and dangerous types of underground accidents - sudden outbursts of coal, rock and gas. In the event of a sudden outburst, the air distribution existing in the ventilation network experiences a sharp dynamic effect, leading to a violation of the stability of the ventilation of the workings close to the center of the outburst and the overturning of the air flow in them. The methane released in this case forms an atmosphere dangerous for humans in the adjacent workings. The size of the gas contamination zone depends on many factors: the intensity of the outburst, the ventilation scheme of the mine, the presence of ventilation facilities, their number, and others, and can become the object of special studies, including the study of the outburst process itself and its interaction with the ventilation network. The specificity of the occurrence of an oytburst as a type of accidents does not allow obtaining statistical and experimental results directly during its course, which greatly complicates the study of this process. In this regard, the most acceptable research method that allows assessing the results of the interaction of the outburst with the ventilation network and, guided by them, to develop effective measures to eliminate its consequences and restore the normal functioning of the mine, is the simulation method using a PC. The article analyzes the stages of changes in the mining-geological and mining-technical conditions preceding the occurrence of the outburst, the stage of the outburst, the calculation formulas are given, by which it is possible to evaluate the configuration and dynamics of the development of the zone polluted with methane as a result of the outburst. The results of modeling the gas-dynamic manifestations of the outburst and its effect on the state of mine ventilation are of great importance in ventilation calculations in emergency modes in order to use the possibilities of ventilation effects on an emergency, limit emergency zones and increase the effectiveness of eliminating the consequences of an accident.

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Li, Xu, Ming Tian, Biao Shen, Chuan Yang, Qian Huang et Sayyara Koxmak. « Research on the influence of heat release from cement hydration on the mechanical properties of casing ». Journal of Physics : Conference Series 2729, n^o 1 (1 mars 2024) : 012009. http://dx.doi.org/10.1088/1742-6596/2729/1/012009.

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Abstract In order to study the influence of cement hydration heat release on the mechanical properties of casing, this paper calculates the wellbore temperature and pressure field based on the mathematical model of steady-state heat conduction of casing-cement ring-formation rock, establishes a mathematical model for the mechanical evaluation of cement hydration heat release and casing interaction, and performs finite element calculation and experimental simulation of the effect of cement hydration heat release on casing loss, and the results show that the results show: Along the axial direction of the wellbore, the maximum stress on the entire cement ring occurs in the lower position of the cement ring, and the maximum deformation on the casing occurs in the middle position. The axial stress variation range of the middle part of the casing is 50MPa, and the strain is 0.12%; The axial stress variation range of the outer ring is 235MPa, and the strain is 0.09%; The circumferential stress of the middle part varies from 500MPa to 0.255%. It is found that the stress and strain in the middle part of cement sheath are large, and yield is prone to occur. Under the action of cement hydration heat release, the long-axis elliptical deformation of (7.15∼31.8) mm occurs in the casing, that is, a large ovality is produced, which weakens the collapse strength of the casing. Two repeated tests showed that under the cement hydration heat release condition at the casing loss position, the temperature change of 60°C caused the increase of axial force of casing column and the increase of annular air pressure, which caused the non-uniform deformation of casing under the composite load of external extrusion and compression axial force.

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Riechelmann, S., D. Buhl, A. Schröder-Ritzrau, D. F. C. Riechelmann, D. K. Richter, H. B. Vonhof, J. A. Wassenburg, A. Geske, C. Spötl et A. Immenhauser. « The magnesium isotope record of cave carbonate archives ». Climate of the Past 8, n^o 6 (20 novembre 2012) : 1849–67. http://dx.doi.org/10.5194/cp-8-1849-2012.

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Abstract. Here we explore the potential of magnesium (δ26Mg) isotope time-series data as continental climate proxies in speleothem calcite archives. For this purpose, a total of six Pleistocene and Holocene stalagmites from caves in Germany, Morocco and Peru and two flowstones from a cave in Austria were investigated. These caves represent the semi-arid to arid (Morocco), the warm-temperate (Germany), the equatorial-humid (Peru) and the cold-humid (Austria) climate zones. Changes in the calcite magnesium isotope signature with time are compared against carbon and oxygen isotope records from these speleothems. Similar to other proxies, the non-trivial interaction of a number of environmental, equilibrium and disequilibrium processes governs the δ26Mg fractionation in continental settings. These include the different sources of magnesium isotopes such as rainwater or snow as well as soil and host rock, soil zone biogenic activity, shifts in silicate versus carbonate weathering ratios and residence time of water in the soil and karst zone. Pleistocene stalagmites from Morocco show the lowest mean δ26Mg values (GDA: −4.26 ± 0.07‰ and HK3: −4.17 ± 0.15‰), and the data are well explained in terms of changes in aridity over time. The Pleistocene to Holocene stalagmites from Peru show the highest mean value of all stalagmites (NC-A and NC-B δ26Mg: −3.96 ± 0.04‰) but only minor variations in Mg-isotope composition, which is consistent with the rather stable equatorial climate at this site. Holocene stalagmites from Germany (AH-1 mean δ26Mg: −4.01 ± 0.07‰; BU 4 mean δ26Mg: −4.20 ± 0.10‰) suggest changes in outside air temperature was the principal driver rather than rainfall amount. The alpine Pleistocene flowstones from Austria (SPA 52: −3.00 ± 0.73‰; SPA 59: −3.70 ± 0.43‰) are affected by glacial versus interglacial climate change with outside air temperature affecting soil zone activity and weathering balance. Several δ26Mg values of the Austrian and two δ26Mg values of the German speleothems are shifted to higher values due to sampling in detrital layers (Mg-bearing clay minerals) of the speleothems. The data and their interpretation shown here highlight the potential but also the limitations of the magnesium isotope proxy applied in continental climate research. An obvious potential lies in its sensitivity for even subtle changes in soil-zone parameters, a hitherto rather poorly understood but extremely important component in cave archive research. Limitations are most obvious in the low resolution and high sample amount needed for analysis. Future research should focus on experimental and conceptual aspects including quantitative and well-calibrated leaching and precipitation experiments.

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Wachowicz, Jan, Jacek Marian Łączny, Sebastian Iwaszenko, Tomasz Janoszek et Magdalena Cempa-Balewicz. « Modelling of Underground Coal Gasification Process Using CFD Methods / Modelowanie Procesu Podziemnego Zgazowania Węgla Kamiennego Z Zastosowaniem Metod CFD ». Archives of Mining Sciences 60, n^o 3 (1 septembre 2015) : 663–76. http://dx.doi.org/10.1515/amsc-2015-0043.

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Abstract The results of model studies involving numerical simulation of underground coal gasification process are presented. For the purpose of the study, the software of computational fluid dynamics (CFD) was selected for simulation of underground coal gasification. Based on the review of the literature, it was decided that ANSYS-Fluent will be used as software for the performance of model studies. The ANSYS- -Fluent software was used for numerical calculations in order to identify the distribution of changes in the concentration of syngas components as a function of duration of coal gasification process. The nature of the calculations was predictive. A geometric model has been developed based on construction data of the georeactor used during the researches in Experimental Mine “Barbara” and Coal Mine “Wieczorek” and it was prepared by generating a numerical grid. Data concerning the georeactor power supply method and the parameters maintained during the process used to define the numerical model. Some part of data was supplemented based on the literature sources. The main assumption was to base the simulation of the georeactor operation on a mathematical models describing reactive fluid flow. Components of the process gas and the gasification agent move along the gasification channel and simulate physicochemical phenomena associated with the transfer of mass and energy as well as chemical reactions (together with the energy effect). Chemical reactions of the gasification process are based on a kinetic equation which determines the course of a particular type of equation of chemical coal gasification. The interaction of gas with the surrounding coal layer has also been described as a part of the model. The description concerned the transport of thermal energy. The coal seam and the mass rock are treated as a homogeneous body. Modelling studies assumed the coal gasification process is carried out with the participation of separately oxygen and air as a gasification agent, under the specific conditions of the georeactor operations within the time interval of 100 hours and 305 hours. The results of the numerical solution have been compared with the results of experimental results under in-situ conditions.

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Cao, Jiansheng, Changming Liu et Wanjun Zhang. « Response of rock-fissure seepage to snowmelt in Mount Taihang slope-catchment, North China ». Water Science and Technology 67, n^o 1 (1 janvier 2013) : 124–30. http://dx.doi.org/10.2166/wst.2012.542.

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The complex physiographic and hydrogeological systems of mountain terrains facilitate intense rock-fissure seepages and multi-functional ecological interactions. As mountain eco-hydrological terrains are the common water sources of river basins across the globe, it is critical to build sufficient understanding into the hydrological processes in this unique ecosystem. This study analyzes infiltration and soil/rock-fissure seepage processes from a 65 mm snowfall/melt in November 2009 in the typical granitic gneiss slope catchment in the Taihang Mountains. The snowfall, snowmelt and melt-water processes are monitored using soil-water time-domain reflectometry (TDR) probes and tipping bucket flowmeters. The results suggest that snowmelt infiltration significantly influences soil/rock water seepage in the 0–100 cm soil depth of the slope-catchment. It is not only air temperature that influences snowmelt, but also snowmelt infiltration and rock-fissure seepage. Diurnal variations in rock-fissure seepage are in close correlation with air temperature (R2 > 0.7). Temperature also varies with soil/rock water viscosity, which element in turn influences soil/rock water flow. Invariably, water dynamics in the study area is not only a critical water supply element for domestic, industrial and agricultural uses, but also for food security and social stability.

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Gabrovšek, Franci. « How do caves breathe : The airflow patterns in karst underground ». PLOS ONE 18, n^o 4 (3 avril 2023) : e0283767. http://dx.doi.org/10.1371/journal.pone.0283767.

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Caves and their surrounding fracture systems in the vadose zone of karst regions host a unique atmospheric environment. Understanding the airflow patterns in caves is critical to understanding the properties of the subsurface atmosphere and the chemical interactions between air, water, and rock. The most common driver of airflow in caves is the density difference between the subsurface and the outside air, known as the chimney effect. Observations show that seasonal airflow patterns in caves also depend on the geometry of passages. In this work, I present and use a numerical model of a passage embedded and thermally coupled to a rock mass to study the relationship between the airflow pattern and passage geometry. As the outside air enters the subsurface, it approaches thermal equilibrium with the rock mass along a characteristic relaxation length. This determines the temperature and density contrast between the inside and outside air, and the resulting pressure difference, which drives the airflow. In passages with non-uniform outlines and/or cross-sections, the relaxation length may depend on the flow direction, resulting in different airflow velocities in cold and warm periods for the same absolute temperature difference between the massif and the external temperature. In a passage with a V-shaped longitudinal profile, the airflow is triggered by instability which causes the feedback between the relaxation length and airflow velocity. The airflow pattern can also be altered by snow and ice. Heat transfer in the rock and the thermal inertia of the rock also change the relaxation lengths and cause hysteresis in the curve presenting the airflow velocity vs. temperature difference.

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Bazgaou, Abderrahim, Hicham Fatnassi, Rachid Bouharroud, Rachid Tiskatine, Ahmed Wifaya, Hassan Demrati, Lahcen Bammou, Ahmed Aharoune et Lahcen Bouirden. « CFD Modeling of the Microclimate in a Greenhouse Using a Rock Bed Thermal Storage Heating System ». Horticulturae 9, n^o 2 (1 février 2023) : 183. http://dx.doi.org/10.3390/horticulturae9020183.

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The rock bed heating system is a more cost-effective concept for storing thermal energy use in greenhouses at night during the cold winter season. This system is considered an environmentally friendly solution compared to conventional heating systems that rely on fossil fuels. Despite the abundance of research on thermal energy-based heating systems, only limited work on climate modeling in greenhouses using rock bed heat storage systems has been reported. To fill this research gap, this study aims to simulate the microclimate in a greenhouse equipped with a rock bed heating system using computational fluid dynamics (CFD) models. User-defined functions have been implemented to account for the interactions between the plants and the air within the greenhouse. Crop rows and rock bed blocks have been considered as porous media with their dynamic and thermal proprieties. The model’s accuracy was approved by comparing simulated and experimental climate parameter data from the greenhouse. The model’s ability to predict temperature, humidity, and air velocity fields in the greenhouse as well as in the rock bed system during both phases of energy storage and restitution was demonstrated. The thermal, dynamic, and hygric fields were accurately replicated with this numerical model. The growing zone had a vertical temperature gradient between the ground and the greenhouse roof, as well as high humidity. The distribution of temperature fields along the rock bed blocks showed a significant temperature gradient between the air inlet and outlet in the blocks during the two phases of heat storage and restitution. As a result, the model could be useful for sensitivity studies to improve the performance of this thermal storage heating system.

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Mineev, Serhii P., Serhii А. Kurnosov, Serhii Yu Makeiev et Leonid А. Novikov. « Geoenvironmental aspects of mine methane emissions ». Journal of Geology, Geography and Geoecology 31, n^o 3 (25 septembre 2022) : 521–28. http://dx.doi.org/10.15421/112248.

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The purpose of the work is to reveal the regularities of the influence of the gaseous phase on the process of filtering carbonated liquid and to characterize the physi-cochemical processes during the implementation of the method of reducing mine methane emissions. The development of minerals can be accompanied by the release of a large amount of methane into the mined-out space. This leads to atmospheric air pollution and consequently to ecological disturbances. This causes methane emissions to the mined-out space and to the surface of the earth cause by the filtration processes of gases and liquids in the rocks. The intensity of fluid filtration through crack and pore systems depends on the content and properties of the fluids and the reservoir properties of the rocks. It is known that methane release to the atmosphere can be observed after mines have been mothballed. This is a problem for many countries around the world where coal and oil and gas fields are being exploited. Investment in methane production and utilization projects is therefore important. Research on fluids filtration processes allow for the development of effective methane recovery methods, and ways to reduce methane emission speed. The result is the reduced air pollution and an improved environmental situation. The paper presents the filtration properties of rocks with different structures and textures. Filtration of carbonated liquid (water-methane) in fractures and pores is considered. It found that an increase in methane concentration in the carbonated liquid leads to a decrease in the phase permeability coefficient for water and an increase for methane. This character of change in phase permeability leads to methane accumulation in crack and pores. The dependence of the average carbonated liquid filtration rate in a rectilinear fracture on the methane concentration and the fracture axis angle of inclination is obtained. The average ascending filtration speed of the carbonated liquid is determined to be greater than the average descending filtration speed. This is due to the effect of the ejection force that acts on the gas bubbles in the liquid. The authors propose a method of blocking methane seepage by physicochemical treatment of the rock mass. The methane blocking effect is achieved by creating a gas-tight zone in areas with a high risk of methane migration to the ground surface. The result is a reduction in methane emissions to the mined-out space and the environment. When the method is realized, the solid product of the polymer solution enters cracks with a disclosure greater than 6 μm or pore channels with an average diameter of 6 μm. At the same time, the water released by the destabi- lization of the polymer solution blocks the methane in small cracks and pores. In pore channels with an average diameter of less than 25 μm, there is a sharp increase in the dynamic viscosity of the polymer solution. This effect is due to an increase in the intermolecular interaction forces between the polymer solution and the walls of the filtration channels. Coagulation and destabilization of the polymer solution in cracks and pores is due to the separation of large agglomerates of macromolecules.

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Huang, Yi, Zhongwei Wu, Xiaoming Sun, Yan Wang, Guiyong Shi, Wei Zhai et Yao Guan. « He-Ar Isotopes and Trace Gas Compositions of Fluid Inclusions in Massive Sulphides from the Yushui Copper-Polymetallic Deposit, South China : Metallogenic Implications ». Minerals 9, n^o 5 (29 avril 2019) : 258. http://dx.doi.org/10.3390/min9050258.

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The Yushui ore deposit, located in the middle section of the Yong’an-Meixian Hercynian depression, is a medium-sized Cu-polymetallic massive sulphide deposit in Eastern Guangdong Province, South China. This deposit is characterized by unusually high copper grade (up to 50–60 wt. % Cu). Other metallic elements, such as lead, zinc and silver, are also economically important in the Yushui ore bodies. The aim of this study was to apply N2–Ar–He systematics, together with organic gases (light-hydrocarbon tracers), to constrain the origin and evolution of ore-forming fluids. The helium-argon isotopes and trace gas compositions of fluid inclusions trapped within metal sulphide minerals were measured for a number of bonanza ores from the Yushui deposit. The noble gas concentrations in the studied samples vary over one to two orders of magnitude (4He: 2.27–160.00 × 10−5 cm3 STP g−1; 3He: 0.53–34.88 × 10−12 cm3 STP g−1; 40Ar: 6.28–37.82 × 10−7 cm3 STP g−1; 36Ar: 1.25–10.40 × 10−9 cm3 STP g−1). Our data show a narrow range of 3He/4He ratios from 0.006 to 0.056 Ra (~0.026 Ra on average, n = 8), which are considerably lower than the modern atmospheric end-member value; whereas the 40Ar/36Ar ratios (ranging from 333.76 to 501.68, with an average of 397.53) are significantly greater than that of air-saturated water. Most of the bornite samples have somewhat higher 3He/4He ratios of trapped fluids when compared to chalcopyrite. Overall, these He-Ar results are well within the range of crustal reservoir, thus implying a predominantly crustal source (originated from Caledonian basement) for ore-forming solutions, with little contribution from mantle-derived fluids. Analysis of the N2–Ar–He composition in Cu-rich sulphides indicates that the Yushui ore-forming fluids were probably derived from formation water (or basinal hot brines). Moreover, organic gas species identified in sulphide-hosted fluid inclusions are mainly composed of C1–C4 alkanes, while the concentrations of unsaturated olefins and aromatic hydrocarbons are very low. In particular, most chalcopyrite samples with relatively low 3He/4He ratios (0.006–0.016 Ra) and 40Ar*/4He values (0.0002–0.0012) are generally characterized by very high CO2/CH4 ratios (~60–102). All these suggest that main-stage Cu-Ag metallogenic processes might have not been affected by high-temperature magmatic activities or superimposed by strong metamorphic overprinting, although some chalcopyrite-rich ores appear to be influenced by later stage hydrothermal processes. In summary, neither magmatic input nor convecting seawater has played an important role in the formation of Yushui copper-polymetallic deposit. The massive sulphide ore bodies were products of water–rock interaction between metal-bearing basinal brines and the host sedimentary strata.

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Djuniwati, S., H. B. Pulunggono et Suwarno . « The Effect of Organic Matter (Centrosema pubescens) and Rock Phosphate Application on the Activity of Phosphatase and P Fraction of Latosol Soil in Darmaga, Bogor ». Jurnal Ilmu Tanah dan Lingkungan 9, n^o 1 (1 avril 2007) : 10–15. http://dx.doi.org/10.29244/jitl.9.1.10-15.

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One of the problems of acid soils such as Latosol is very low in P-availabi/ity due to high P-j'vcation in those soils. Sincesoils is deficiency of P, adaptation of plants and microorganisms to overcome deficiency of P in soil is by producing phosphatase. Phosphatase. is an enzyme that able to catalize transformation of organic P to inorganic P, and produced by plant roots, residual of plants and microorganisms. Organic mailer as a source of P besides N and energy formicroorganisms, and then rock phosphate as an alternative P fertilizer were used in this research. The objective of theresearch was to study the effect of organic matter (Centrocema pubescent) and rock phosphate application on phosphataseactivity and P fraction of Latosol soil from Darmaga, Bogor. The experiment was designed by completely randomized designwith two factors and three replications. The first factor was application of organic matter with the rate of 0, 2.5, and 5 %, and the second factor was application of rock phosphate with the rate of 0, 20, and 40 ppm P. Soil equivalent to four hundred grams of oven dried soil, organic matter, and rock phosphate were mixed based on the treatments of the experiment, and were placed in plastic pots, and then were incubated for 8 weeks period After incubation period, the soil were air dried and analyzed for phosphatase activity, available P, and organic and inorganic P. The result showed that organic mailer increased activities of acid and alkaline phosphatase, organic and inorganic-P of soil. On the other hand, rocle phosphate increased inorganic P but decreased activities of acid phosphatase,. Application of organic matter or rock phosphate on activity of acid phosphatase was higher (2.3-2.6 times) than on alkaline phosphatase. There was no effect of combinationbetween organic matter and rock phosphate on the activity of phosphatase and organic/inorganic P. Combination betweenorganic matter and rock phosphate Significantly affected available P. In each rates of rock phosphate given, the increasing rate of organic matter increased available P in their interactions, on the contrary, in each rates of organic matter, the increasing rate of rock phosphate did not affect available P in their interactions. However it was tended to decrease in therate of 40 ppm P.

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Antoro, Pedri, et Nelvia Nelvia. « PERTUMBUHAN PADI GOGO DI MEDIUM ULTISOL DENGAN PEMBERIAN CAMPURAN FOSFAT ALAM DAN COCOPEAT PADA DUA KONDISI KADAR AIR ». Jurnal Solum 15, n^o 2 (30 août 2018) : 60. http://dx.doi.org/10.25077/jsolum.15.2.60-65.2018.

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The main problem of upland rice cultivation in Ultisol are fixation of P, solubility and saturation of Al are the height and water content is low. The research aim to study the effect of interaction of application of mixture of cocopeat with rock phosphate (RP) on growth of upland rice in Ultisols medium at two water content condition. The research was conducted at the Green House of the Faculty of Agriculture, University of Riau, Pekanbaru from February to July 2017. This research in form factorial experiment was arranged in a completely randomized design. The first factor was mixture of RP with cocopeat consist of 7 levels (0, 30, 45 and 60 kg P2O5/ha each dose + cocopeat dose 10 tons/ha and 30, 45 and 60 kg P2O5/ha without cocopeat). The second factor was water content consists of 2 levels (field capacity and 25% under field capacity), each combination repeated 3 times. The results show the application of rock phosphate dose of 30 kg P2O5/ha + 10 tons cocopeat/ha or without cocopeat increased the growth of upland rice include plant high, number of maximum tiller and productive tiller and dry weight of straw compared to without RP both on the field capacity and 25% below field capacity condition, the increasing of RP dose to 45-60 kg P2O5/ha tended to increase each parameter.Key words : rock phosphate, water content, cocopeat, upland rice.

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Nikolaev, Aleksandr. « The effect of methane emission on air distribution in potash mine production units ». Izvestiya vysshikh uchebnykh zavedenii Gornyi zhurnal 6 (15 septembre 2021) : 87–97. http://dx.doi.org/10.21440/0536-1028-2021-6-87-97.

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Introduction. It has been found that due to light gas (including methane) emission in rooms under development, there develops an additional natural draught between the mine workings. The calculation has shown that methane emission from the rock mass conditions the low value of the additional natural draught. However, even minor additional natural draught interacting with a thermal drop of pressure caused by temperature rise in the conveyor shaft changes the direction of the delivery air stream. While in up the dip blocks and panels the resultant natural draught promotes ventilation, in the down the dip production units it prevents air circulation in the required direction. Research methods. The methods and results of calculating the value and direction of the natural draught for real panels of potash mines at the Upper Kama potash deposit under various conditions have been presented together with the simulation observations of methane distribution in the room with a point source of emission. Results. Model analysis has shown that even under the low amount of gas emission out of the point source in the blind room (of a hole drilled in the roof), the concentration of gas in the gas-air mixture entering the belt heading reaches 2%. Conclusions. To ensure the safety of mining and reduce the risk of emergency when calculating the volume of air required to ventilate the production units, the dynamics of methane emission out of the rock mass should be taken into account as well as its further distribution across the mine workings.

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Nikolaev, Aleksandr. « The effect of methane emission on air distribution in potash mine production units ». Izvestiya vysshikh uchebnykh zavedenii Gornyi zhurnal 6 (15 septembre 2021) : 87–97. http://dx.doi.org/10.21440/0536-1028-2021-6-87-97.

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Introduction. It has been found that due to light gas (including methane) emission in rooms under development, there develops an additional natural draught between the mine workings. The calculation has shown that methane emission from the rock mass conditions the low value of the additional natural draught. However, even minor additional natural draught interacting with a thermal drop of pressure caused by temperature rise in the conveyor shaft changes the direction of the delivery air stream. While in up the dip blocks and panels the resultant natural draught promotes ventilation, in the down the dip production units it prevents air circulation in the required direction. Research methods. The methods and results of calculating the value and direction of the natural draught for real panels of potash mines at the Upper Kama potash deposit under various conditions have been presented together with the simulation observations of methane distribution in the room with a point source of emission. Results. Model analysis has shown that even under the low amount of gas emission out of the point source in the blind room (of a hole drilled in the roof), the concentration of gas in the gas-air mixture entering the belt heading reaches 2%. Conclusions. To ensure the safety of mining and reduce the risk of emergency when calculating the volume of air required to ventilate the production units, the dynamics of methane emission out of the rock mass should be taken into account as well as its further distribution across the mine workings.

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Esmaeilzadeh, Pouriya, Zahra Fakhroueian, Alireza Bahramian et Sharareh Arya. « Influence of ZrO₂ Nanoparticles Including SDS and CTAB Surfactants Assembly on the Interfacial Properties of Liquid-Liquid, Liquid-Air and Liquid-Solid Surface Layers ». Journal of Nano Research 21 (décembre 2012) : 15–21. http://dx.doi.org/10.4028/www.scientific.net/jnanor.21.15.

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This work investigates the effects of nanometric (5-8 nm) ZrO2 nanoparticles on adsorption of two surfactants, SDS (sodium dodecyl sulfate) and C12TAB (dodecyl trimethyl ammonium bromide) into oil/water, air/water and solid/water interfaces. Increasing the concentration of nanoparticles reduces the interfacial tension and surface tension of SDS at low surfactant concentration (< cmc) but it has a minor effect on interfacial and surface tension of C12TAB. Repulsive columbic interactions between SDS molecules and nanoparticles can cause the higher adsorption of surfactant at the oil/water interface. Adsorption of both surfactants on carbonate rock increases by adding nanoparticles to the system. This possibly happened because of the formation of surfactant-nanoparticle negatively charged aggregates that tend to adsorb on positively charged surface layer of carbonate rock. ZrO2 nanoparticles are surface active at the oil/water interface too, as the results of interfacial tension indicate they can decrease the n-heptane/water IFT about 14 units.

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Thornbush, MJ, et SE Thornbush. « Professor Geikie’s 1880 paper, ‘Rock-weathering, as illustrated in Edinburgh Churchyards’, in Proceedings of the Royal Society of Edinburgh, Vol. 10, pages 518–532 : Contribution to weathering and cross-disciplinary necrogeography within physical geography ». Progress in Physical Geography : Earth and Environment 42, n^o 5 (23 août 2018) : 667–76. http://dx.doi.org/10.1177/0309133318793575.

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This Classics Revisited paper examines the contribution of Geikie’s seminal paper, presented to The Royal Society of Edinburgh in 1880, to physical geography as part of geomorphology, weathering, and necrogeography. From this standpoint, physical geography is approached as interdisciplinary, housing geomorphology and cross-disciplinary and applied research in the areas of climate and the environment affecting urban settings. Mortuary evidence is specifically addressed here, as Geikie presented observations and discussion of older churchyards situated in Edinburgh, Scotland. His emphasis permitted a focus on rock-air interactions of funerary remains carved from calcareous materials, sandstones and flagstones, and granites. The former (marbles and limestones) represent the main content of the paper, with an emphasis on superficial solution, internal disintegration, and curvature and fracture affecting calcareous rocks. Geikie’s areas of research interest are still prevalent in the literature today and can be construed as a pioneering work, representing a formative part of rock weathering affected by both climatic and environmental geomorphology in an urban setting.

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