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Copyright of Journal of Shenzhen University Science & Engineering is the property of Editorial Department of Journal of Shenzhen University Science & Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study delves into the formation mechanisms of unconventional oil reservoirs located within the Carboniferous strata of the geologically intricate Hudson Oilfield, situated in the Tarim Basin, integrating extensive geological survey data with a sophisticated, physically simulated cross-sectional model specifically constructed for this study. This integrated approach enables a detailed examination of the distribution of interlayers and their profound effects on reservoir heterogeneity, as well as the non-equilibrium dynamics at the oil-water interface. Key findings reveal that randomly distributed calcareous interlayers significantly increase reservoir compartmentalization, raising heterogeneity indices by 30%, while oil-water interface inclinations exceeding 100 m were observed in 20% of the studied reservoirs, along with lateral hydrocarbon reversals, challenging traditional knowledge. Variations in porosity and permeability have led to a 45% discrepancy in estimations of recoverable reserves, underscoring the complexity of these systems. Advanced simulation techniques have improved the accuracy of predicting unconventional reservoir characteristics by 25% over conventional geological methods, highlighting the importance of incorporating reservoir instability and the complexity of interlayer structures into the analysis of unconventional hydrocarbon systems. These findings significantly advance our understanding of Carboniferous unconventional reservoir evolution, offering new perspectives on the role of these factors and informing more effective exploration strategies and enhanced efficiency in hydrocarbon recovery processes. [ABSTRACT FROM AUTHOR]

Salinity intrusion is one of the most pressing threats to unconfined coastal aquifers, and its simulation is of great importance for groundwater research and management. This study compared the performances of two computational fluid dynamics (CFD) software applications, ANSYS Fluent 2022 R2 and COMSOL Multiphysics 5.6, in simulating the transport of saltwater in a pilot-scale experimental setup, which was built to recreate two boundary conditions of unconfined aquifers with homogeneous stratigraphy. The experiments were performed until the saline wedge reached a quasi-steady-state condition. Sequential photographs and image analysis were required to record the movement of the saline toe and the saline wedge location. The maximum toe length was achieved under the head-controlled boundary condition, with a toe length of 1.6 m after 7 h of the experiment, and 1.65 m and 1.79 m for the COMSOL and ANSYS Fluent simulations, respectively. The findings evidence that the flux-controlled condition produced a better representation of the saline wedge than the head-controlled condition, indicating good agreement between the CFD simulations and the experimental data. Recommendations for future research include CFD simulations of real coastal aquifers and coupling fluid dynamics with other processes such as land subsidence. [ABSTRACT FROM AUTHOR]

This study delves into the formation mechanisms of unconventional oil reservoirs located within the Carboniferous strata of the geologically intricate Hudson Oilfield, situated in the Tarim Basin, integrating extensive geological survey data with a sophisticated, physically simulated cross-sectional model specifically constructed for this study. This integrated approach enables a detailed examination of the distribution of interlayers and their profound effects on reservoir heterogeneity, as well as the non-equilibrium dynamics at the oil-water interface. Key findings reveal that randomly distributed calcareous interlayers significantly increase reservoir compartmentalization, raising heterogeneity indices by 30%, while oil-water interface inclinations exceeding 100 m were observed in 20% of the studied reservoirs, along with lateral hydrocarbon reversals, challenging traditional knowledge. Variations in porosity and permeability have led to a 45% discrepancy in estimations of recoverable reserves, underscoring the complexity of these systems. Advanced simulation techniques have improved the accuracy of predicting unconventional reservoir characteristics by 25% over conventional geological methods, highlighting the importance of incorporating reservoir instability and the complexity of interlayer structures into the analysis of unconventional hydrocarbon systems. These findings significantly advance our understanding of Carboniferous unconventional reservoir evolution, offering new perspectives on the role of these factors and informing more effective exploration strategies and enhanced efficiency in hydrocarbon recovery processes.

Copyright of Journal of Ceramics / Taoci Xuebao is the property of Journal of Ceramics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Significance] Dolomite is a common carbonate rock and servers as an important reservoir for oil and gas. In the Sichuan Basin marine carbonate successions, for example, approximately 96% of the proved gas reserves are in dolomite reservoirs. Thus, studies of the dolomitization process, and how pores originate in dolomite, have made significant progress. However, how dolomitization affects the development of pores is still argued. [Methods] By summarizing the main theoretical viewpoints of pore origin, combined with the results of various replacement experimental simulations, this study explains the formation and evolution of pores during dolomitization and suggests lines of future research on pore origin. [Progress] The pores in dolomite are either inherited from its precursor limestone, or they have resulted from the dissolution of calcite during or after dolomitization. Dolomitization might increase, maintain or reduce reservoir porosity, depending on the environment, residence time and nature of the dolomitizing fluids. [Conclusions and Prospects] Replacement observations in experimental simulations imply that replacement is a micro-process of dissolution, migration and precipitation, accompanied by the formation of new pores that act as a channel for fluid and ion exchange to maintain the reaction. The molar volume of minerals does not influence the formation of pores. This is determined by relative solubility: that is, if the dissolution of reactants is greater than the precipitation of products, pore volume increases. The whole replacement process is accompanied by the formation of new pores, but they are mainly micropores, and their contribution to the effective porosity of a reservoir remains to be further evaluated. [ABSTRACT FROM AUTHOR]

A modeling method with the fractal structure to describe the elastic-viscous-plastic properties of materials is proposed in this paper. Moreover, the solution can be obtained without solving the corresponding infinite order differential equation. Then, a model (L-R model) to characterize the elastic-viscous-plastic properties of materials with complex infinite order fractal structure was established based on this modeling method. The mechanical properties are described by the constitutive relationship of spring (elasticity), adhesive pot (viscosity), and plastic body (plasticity) elements by MATLAB/Simulink. The three-element model is connected in series and parallel according to the rules of the Bingham model. Then, the Bingham model is used as the original model to set and iterate according to the fractal theory. And the solution of the corresponding infinite order differential equation for describing elastic-viscous-plastic of materials can be obtained directly without solving the complex differential equation of the model. To verify the reliability of this modeling method and its solution results, cyclic load experiments were carried out on five materials with different fractal structures, steel, slate, coal, red sandstone, and salt rock. Comparing the experimental results with the solution results, it indicated that the established model can effectively describe the material’s performance of the elastic-viscous-plastic properties. [ABSTRACT FROM AUTHOR]

Soil salt accumulation is a widespread problem leading to diminished crop yield and threatening food security in many regions of the world. The soil salinization problem is particularly acute in areas that lack adequate soil water drainage and where a saline shallow water table (WT) is present. In this study, we present laboratory‐scale column experiments, extending over a period of more than 400 days that focus on the processes contributing to soil salinization. We specifically examine the combined impact of soil compaction, surface water application model and water quality on salt dynamics in the presence of a saline shallow WT. The soil columns (60 cm height and 16 cm diameter) were packed with an agricultural soil with bulk densities of 1.15 and 1.34 g/cm−3 for uncompacted and compacted layers, respectively, and automatically monitored for water content, salinity and pressure. Two surface water compositions are considered: fresh (deionized, DI) and saline water (~3.4 mS/cm). To assess the sensitivity of compaction on salt dynamics, the experiments were numerically modelled with the HYDRUS‐1D computer program. The results show that the saline WT led to rapid salinization of the soil column due to capillarity, with the salinity reaching levels much higher than that at the WT. However, compaction layer provided a barrier that limited the downwards moisture percolation and solute transport. Furthermore, the numerical simulations showed that the application of freshwater can temporarily reverse the accumulation of salts in agricultural soils. This irrigation strategy can help, in the short‐term, alleviate soil salinization problem. The soil hydraulic properties, WT depth, water quality, evaporation demand and the availability of freshwater all play a role in the practicability of such short‐term solutions. The presence of a saline shallow WT would, however, rapidly reverse these temporary measures, leading to the recurrence of topsoil salinization. [ABSTRACT FROM AUTHOR]

This paper presents a designed experimental simulation scheme for dynamic air gap eccentricity (DAGE) faults in permanent magnet synchronous generator (PMSG), along with the testing of their electromechanical characteristics. Unlike previous studies, this paper proposes and applies an experimental device setting scheme that enables accurate and convenient calibration of the DAGE fault degree, offering a novel solution for practical DAGE simulation. The experimental unit measures the electromechanical characteristics of the PMSG before and after the DAGE fault, taking into account the influence of load. The mechanical parameter considered is the stator vibration, while the electrical parameter is the circulating current parallel branches (CCPB) inside the stator winding. The characteristic frequencies of stator vibration and CCPB under the DAGE fault are analyzed based on the experimental results and verified through theoretical calculations and finite element analysis (FEA). The findings demonstrate the effectiveness of the proposed DAGE experimental device. Moreover, DAGE failure increases the strength of stator vibration and introduces new frequency components, namely fr and 2f ± fr. Under normal operation, the PMSG exhibits no CCPB. However, DAGE faults cause CCPB with frequency components of f ± fr. Moreover, the severity of the fault degree positively correlates with larger root‐mean‐square (RMS) values and characteristic frequency amplitudes of stator vibration and CCPB. Furthermore, the amplitude of stator vibration and CCPB decreases with increasing load. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The article theoretically analyzes the relevant knowledge of shot put in the shot put sports training of colleges and universities. The fractional differential equations are used to analyze the influence of the initial speed and the shot situation on the performance of the shot put. We obtain the joint angles of each stage of the shot throw through experimental design, time-consuming, final speed, limb displacement, shot-put shot speed, height, angle, and other kinematic parameters, and the shot-put motion trajectory of the picture stroke of the relevant action characteristics.

On the basis of analyzing the fluid phase behavior during the transformation from gas reservoir to gas storage, a mathematical model and an experimental simulation method are established to describe the oil-gas phase behavior during the whole injection- production process of gas storage. The underground gas storage in the Liaohe Shuang 6 gas reservoir with oil rim is taken as a typical example to verify the reliability and accuracy of the mathematical model and reveal characteristics and mechanisms of fluid phase behavior. In the gas injection stage of the gas storage, the phase behavior is characterized by mainly evaporation and extraction and secondarily dissolution and diffusion of gas in the cap to oil in the oil rim of the reservoir; the gas in gas cap increases in light component content, decreases in contents of intermediate and heavy components, and increases in density and viscosity. The oil of the ring decreases in content of heavy components, increases in contents of light and intermediate components, decreases in density and viscosity, and increases in volume factor and solution gas oil ratio. In the stable operation stage of periodic injection-production of gas storage, the phase behavior shows that the evaporation and extraction capacity of injection gas in the cap to oil rim is weakened step by step, the phase behavior gradually changes into dissolution and diffusion. The gas in gas cap decreases in content of intermediate components, increases in content of light components slowly, and becomes lighter; but changes hardly in density and viscosity. The oil in the oil rim increases in content of heavy components, decreases in content of intermediate components, rises in density and viscosity, and drops in volume factor and solution gas oil ratio.

In the framework of future decarbonization of the energy industry, the safe and effective storage of hydrogen is an important approach to add to a climate-friendly energy system. Until the development of sufficiently large electrical storage systems, the storage of hydrogen in the order of GWh to TWh is envisaged in salt caverns or porous geological formations with a gas-tight covering of salt or claystone. In order to calculate gas losses from these H 2 storage facilities, the H 2 diffusivity of the storage and cap rocks must be known. To determine the hydrogen diffusion rates in these rocks, an experimental set-up was designed, constructed and tested. The set-up comprises two gas chambers, separated by the rock sample under investigation with an exposed area of approximately 7 cm2. The driving force for gas migration through the rock sample from the hydrogen-containing feed gas chamber to the hydrogen-free permeate chamber is the chemical potential (concentration) gradient. With respect to hydrogen migration behaviour, hydrogen breakthrough times and hydrogen diffusion coefficients were determined for dry and wet Bentheimer sandstone, Werra rock salt and Opalinus clay samples. Breakthrough times varied between less than 1 h and 843 h. Based on concentration changes at the permeate side, hydrogen diffusion coefficients were derived ranging from 10−9 to 10−8 m2/s. The differences between the materials and the effect that wetted or water-saturated samples have higher hydrogen retention due to closed pores and microcracks were clearly shown. The experimental set-up proves to be a suitable approach to determine site-specific rock characteristics such as hydrogen diffusion coefficients and breakthrough times for natural geomaterials. • An experimental setup to investigate hydrogen diffusion in rock samples was designed. • Hydrogen diffusion coefficients and breakthrough times were successful determined. • First results for sandstone, rock salt, claystone samples were generated. • Site-specific studies of hydrogen migration in geomaterial for storage is possible. [ABSTRACT FROM AUTHOR]

Engineering and industrial applications, such as heat exchangers, cooling systems, and solar collectors, require designs that optimize heat transfer rates and enhance thermal performance. Corrugated tubes present a viable solution for these applications. In this study, an experimental simulation method was employed to examine the thermo-fluid characteristics of air flow through a one-start horizontally spiraled corrugated tube under turbulent forced convection. A parametric investigation was carried out for various configurations of spirally corrugated tubes subjected to uniform heat flux. Three distinct types of spirally corrugated tubes were investigated: Continuous corrugated tubes with 6mm pitch, continuous corrugated tubes with 18mm pitch, and interrupted corrugated tubes with 6mm pitch. Additionally, a smooth tube was examined for comparison. All tubes were fabricated from copper, and the corrugations were created through cold forming. The effects of air velocity and wall heat flux on flow and heat transfer rates were analyzed, with five air velocities (ranging from 2.5 to 4.5m/s) and six surface heat fluxes (ranging from 5,000 to 10,000W/m2 ) considered. Results revealed that the average Nusselt number for the interrupted corrugated tube was 72.5% higher than the smooth tube, 63.5% higher than the corrugated tube with an 18mm pitch, and 12.5% greater than the corrugated tube with a 6mm pitch. [ABSTRACT FROM AUTHOR]

For a forest ecosystem severely damaged by an earthquake, it is necessary to experimentally simulate and analyze the forest ecosystem restoration process and investigate the forest ecosystem selfrestoration ability. The finite element strength reduction method in the quasi-static method is used to calculate the slope static safety factor of the forest ecosystem, with the connection of the plastic zone and the non-convergence of the calculation results set as the judgment criteria for stability imbalance. When the sliding body has suddenly increased displacement with the plastic zone connected, it means imbalanced slope of the forest ecosystem in the area, and the forest ecosystem restoration ability should be analyzed. The simulated experimental environment was set up by constructing an open-top box, and the observation time was set to 14 months. Experimental simulation revealed that with the passage of time, the final number of the experimental forest ecosystem species was about twice that of the initial number. The final aboveground biomass and underground biomass were about three times of the original, and the soil microbial biomass carbon contents at soil depths of 10 cm - 20 cm and 20 cm - 30 cm were 187.64 w/mg•g-1 and 147.62 w/mg•g-1, respectively, at most, after 14 months. That was, the experimental forest ecosystem is amid gradual restoration at a relatively fast speed. [ABSTRACT FROM AUTHOR]

Copyright of Journal of China University of Petroleum is the property of China University of Petroleum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Groundwater age and groundwater residence time contain important information about groundwater circulation and evolutionary processes, and have been widely used in the study of groundwater circulation patterns in basins.In this paper, we simulated a three-stage flow system model through a multi-stage groundwater flow system demonstrator, and simulated the groundwater age distribution and groundwater residence time distribution based, and found that the bottom of the basin, the downstream of the regional flow, and the basin retention area responded the latest.The local flow system in the shallow part has relatively low concentration values after stabilization, the intermediate flow system is also relatively low compared to the regional flow system in the deep part, and the stagnant zone has relatively large concentration values due to salt accumulation.The groundwater age distribution curves are single-peaked, and the circulation time of the regional flow system is greater than that of the intermediate flow system than that of the local flow system.The residence time distribution monitored in the discharge zones shows that different levels of recharge will produce early, middle and late peaks, and the peaks correspond exactly to the level of the groundwater flow system.It can be judged from the peaks in the discharge zones that the groundwater is recharged from the local, intermediate or regional flow system, and thus the source of contaminants can be determined.The present research results have some significance for the evolution of groundwater circulation and the improvement of groundwater flow system theory.

The increase in metal consumption of industrial production and in the volume of consumption of finished metal products determines the relevance of the development and research of energy-efficient technological processes aimed at reducing costs by reducing the number of operations while maintaining the performance characteristics of the product. In mechanical engineering, the problems of producing blanks with increased dimensional and geometric accuracy and complex configuration are solved by using the widespread method of investment casting. In mechanical engineering, the increase in the use of such a technological approach to producing blanks is hindered by a number of physical phenomena associated with the thermal expansion of investment and ceramic materials, which leads to an increase in the final cost of the product. A significant number of defect-forming factors can be eliminated by applying an innovative solution, which consists in the formation of porous removable patterns by compact compositions based on waxy materials. This method solves the problem of material shrinkage and increases the crack resistance of ceramic molds, which can significantly reduce the share of machining of blanks in the total number of technological operations. Technical tests of the new method made it possible to determine the reason why at present it is not possible to completely get rid of machining of castings. The problem is mainly in the elastic response of the compacted material of the investment composition, which in some cases affects the increase in the size of compacts. This article examines the effect of the initial packing of spherical-shaped elements simulating one- and two-component investment compositions on the stress-strain state of a powder body subjected to unilateral compaction in a rigid cylindrical matrix to technologically reasonable density values. The results of the experiment are presented in the form of stress-strain relations. Preferred conditions for the formation of compacts with minimum values of the elastic response of the compacted material are considered. [ABSTRACT FROM AUTHOR]

Rainfall is critical for financial viability in ranching, yet droughts are becoming more common. The USDA Pasture, Rangeland, and Forage rain‐index insurance program seek to reduce drought‐related financial risks. Using the DRIR‐R model, we test the investment impact of rainfall‐index insurance with two randomized control simulations, one with a general population and one with professional ranchers. We find no evidence of direct impacts of rainfall‐index insurance on herd size or drought adaptation investments. These findings support the idea that the rain‐index insurance policy limits moral hazard in a way that reduces the likelihood of overgrazing that could intensify drought stress. [ABSTRACT FROM AUTHOR]

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In high-voltage cables, because of the close fit of their internal structures, interface pressure is generated between conductor and insulator, which affects the performance of the cable. Studies on the calculation and testing of the interfacial pressure of cable conductors are scarce because of the lack of a unified formula and the difficulty of direct measurement. As such, in this study, we devised two methods for calculating and measuring the interface pressure of cable conductors. In the first, we used two physical experimental methods. We used the friction between cable components to perform the calculation and create an experimental method for determining cable conductor interface pressure; on the basis of the equation of the pressure inside and outside a thick-walled cylinder using elasticity mechanics, we calculated the interface pressure on the basis of the measurement of the strain state of the inner and outer diameters of each layer of the cable under different assembly and stripping conditions. We verified the effectiveness of the methods through physical tests and simulations using a YJLW03 1 × 1200 high-voltage cable. Then, we used simulation software ANSYS and SolidWorks to calculate the interface pressure. With different simulation settings, we obtained results regarding interface pressure. Lastly, these simulated values were individually compared with two physical tests, and the error was calculated. Results obtained in the ANSYS environment showed that interface pressure values determined by the geometric interference normal stress, geometric interference pressure, contact interference normal stress, and contact interference pressure methods were 39.75, 36.84, 5.76, and 36.57 MPa, respectively. In SolidWorks software, we used the contact-stress and X-axis normal stress methods. Results were all 37.36 MPa. Then, simulation results and experimental results were compared, and error was calculated. The comparison showed that the X-axis orthogonal stress method was the most accurate. Errors between the X-axis orthogonal stress method and the two physical experiments were 1.5% and 0.48%. Through the above simulation and physical experiments, we determined the interface pressure between conductors and insulators in a high-voltage power cable. We obtained the cable interface pressure value through two kinds of physical experiments, and these two methods were clearly reliable. Simulation experiments showed that using SolidWorks software to simulate this problem obtained better results. Research results provide technical support and reference for the calculation and measurement of cable interface pressure and the optimization of cable performance. [ABSTRACT FROM AUTHOR]

Experimental simulation of cerebrovascular system would be very beneficial tool to evaluate millions of human body cascade sequence. The Circle of Willis (CoW) recently named Cerebral Arterial Circle (CAC) is a main loop structure of cerebral circulatory system which positioned at the cranium base. In this research, we investigate cerebral artery flow pattern in cerebral arteries including afferent, Willisian, and efferent arteries of CAC emphasizing on communicating and connecting arteries which are main routes in CAC and as a risky sites when autoregulation is occurred in terminal parts of middle cerebral arteries (MCAs) by PMMA (Polymethyl methacrylate) chip and high quality camera which depict Sequential images. This novelty study analyze flow pattern in CAC that have been challenging subject area for many years which have investigated by scientists yet, because flow pattern in CAC indicate complication progression. This research tries to construct new platform in cerebral circulation analyzing method by reliable experimental in-vitro approach. The outcomes of this study demonstrate that communicating arteries especially anterior communicating artery (ACoA) is main artery in CAC flow distribution. [ABSTRACT FROM AUTHOR]

During hydraulic fracturing treatment, huge quantities of gel are pumped into the formation to initiate the fracture, maintain it open and transport the proppant. The fracture dimensionless conductivity (Fcd) is a key parameter to optimize the fracturing design, to estimate the productivity Index (PI) and the folds of increase (FOI). However, these parameters are affected by the gel residues which decrease the fracture conductivity; thus, the proppant cleanup is a very important step to avoid additional damage caused by fracturing fluid due to high gel concentration and the extended time of gel staying in the fracture before cleanup. Throughout the life of Hassi Messaoud, Algeria field, hydraulic fracturing technique has been aggressively used mainly in four producing formations in the Cambrian, with hard formation characteristics, an average permeability range and low reservoir pressure (0.15–0.45 psi/ft) and high stress value between 6000 and 9000 psi. In this paper, an experimental simulation is applied using a self-made cell to determine the effect of different parameters on the fracture conductivity under various bottom-hole conditions where different variables were used: effect of Proppant type, guar gel concentration, temperature, breaker concentration and closure pressure at extended time. An important drop in fracture conductivity was observed varied between 10 and 80% under stresses at interval of 2000 psi and 8000 psi, gel concentration up to 200 lb/1000 gal at extended time and temperature. [ABSTRACT FROM AUTHOR]

The pressure–temperature (P‐T) path of blueschist is usually applied to understanding the evolution of the subducted oceanic crust. Garnet plays a key role in calculating the metamorphic conditions, but sometimes it is absent in the blueschists. Nevertheless, the high‐P experimental simulation may serve as a useful tool to constrain the P‐T conditions. In the middle of the Longmu Co‐Shuanghu Suture, North Tibet, blueschist blocks embedded in the marble were discovered, where garnet is abundant in the core but absent in the marble‐contacting margin. These two kinds of blueschist contain similar mineral assemblage (glaucophane, epidote, and phengite) and show comparable basaltic character. Pseudosection modelling was applied to the garnet‐bearing blueschist that calculated the peak metamorphic condition of ca. 1.9 GPa and 530°C. As for the garnet‐absent blueschist, experiments (1.2–2.3 GPa and 500–800°C) were performed on the designed mixture of 93 wt% basalt and 7 wt% calcite. The results show that the total Fe content in the glaucophane and barroisite is positively correlated with the pressure but not with temperature, which could be regarded as a geobarometer. Accordingly, the peak condition was constrained at 2.3 GPa and 500–600°C. Therefore, the equivalent metamorphic conditions of the blueschists indicate that the Palaeo‐Tethys oceanic crust subducted into at least 70 km. Furthermore, both the experiments and the T‐X (CaCO3) pseudosection, constructed based on basaltic lithology, support that the absence of garnet in the blueschist is predominantly caused by the mixing of calcite. In summary, this study provides a valid attempt in exploring metamorphic conditions by experiment simulation, and evaluates the profound influence of the interaction between the basaltic crust and overlying carbonate‐bearing sediments in the subduction zone. [ABSTRACT FROM AUTHOR]

Traditional mathematics learning always paid excessive attention to the memorisation and repeated practice of theoretical knowledge and ignored guidance on learning method, resulting in bad learning outcome and insufficient problem-solving ability. Based on the theory of ‘chunks’ and ‘objective’, this paper analyses the mathematics learning process from the perspective of experimental simulation, designs a mathematics learning process based on ‘chunk-objective’, and simulates it. The data show that the learning mode is scientific and effective, which can help students learn better according to cognitive rules, thus forming their knowledge structure and improving their ability to solve problems.

LED light sources, and powerful multichip light sources in particular, are currently widely used for lighting household and industrial premises. With an increase in power, the amount of heat increases as well, which leads to an increase in the temperature of semiconductor crystals and, accordingly, to a decrease in the reliability of LEDs and a change in their photometric characteristics. Therefore, when developing the design of LED lighting devices, special attention is paid to thermal management. Since the early 2000s, heat pipes have been widely used to efficiently remove heat from powerful electronic components. They do not require power for moving the working fluid and are most suitable for use in LED luminaires. In this study, the authors carry out a computer simulation of a cooling system based on heat pipes, which is then used to design and test a powerful compact LED lamp with a thermal load of up to 100 W. Heat pipes with a length of 150 mm are used to remove heat from the LED light source to the heat exchanger rings located concentrically around it. The heat exchanger rings are cooled by natural convection of the ambient air. The results of computer modeling of the temperature field of the developed cooling system show that at a power of the LED light source of 140.7 W, the temperature of the LED matrix case is 60.5В°C, and the experimentally measured temperature is 61.3В°C. The experimentally determined thermal power of the LED matrix is 91.5 W. The p-n junction temperature is 79.6В°C. The total thermal resistance of the cooling system is 0.453В°C/W. The obtained results indicate the effectiveness of the developed design.

The lubricating property of mold slag is significant to determine the surface quality of strands. To investigate the friction property of mold slag in the mold, the friction coefficient of the crystalline slag and glassy slag at high temperatures was measured through using a friction and wear testing machine. An edible oil was selected to simulate the lubrication behavior of liquid slag. The results show that during raising temperature from 25 °C, the friction coefficient of slag will increase due to the surface softening. The surface sintering will obviously reduce the friction coefficient of crystalline slag at around 800 °C. The friction coefficient of glassy slag is smaller than that of crystalline slag. The equivalent friction coefficient of liquid slag is below 0.2. The measured friction coefficient can be applied in mathematical models of friction.

Copyright of Journal of Petrochemical Universities / Shiyou Huagong Gaodeng Xuexiao Xuebao is the property of Journal Editorial Department Of Liaoning Shihua University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Third body wear of arthroplasty bearing materials can occur when hard particles such as bone, bone cement or metal particles become trapped between the articulating surfaces. This can accelerate overall implant wear, potentially leading to early failure. With the development of novel bearing materials and coatings, there is a need to develop and standardise test methods which reflect third body damage seen on retrieved implants. Many different protocols and approaches have been developed to replicate third body wear in the laboratory but there is currently no consensus as to the optimal method for simulating this wear mode, hence the need to better understand existing methods. The aim of this study was to review published methods for experimental simulation of third body wear of arthroplasty bearing materials, to discuss the advantages and limitations of different approaches, the variables to be considered when designing a method and to highlight gaps in the current literature. The methods were divided into those which introduced abrasive particles into the articulating surfaces of the joint and those whereby third body damage is created directly to the articulating surfaces. However, it was found that there are a number of parameters, for example the influence of particle size on wear, which are not yet fully understood. The study concluded that the chosen method or combination of methods used should primarily be informed by the research question to be answered and risk analysis of the device.

The fragmentation of coal produces abundant coal gases and is presumed to be the defining characteristic of coal and gas outbursts. Knowing the mechanism of these catastrophic hazards is one of the most important breakthroughs in mining geology. In the outburst process, coal spallation represents a unique failure type and typically leaves behind a spallation area (with a series of fracture textures) in the coal seam. Revealing its features and formation mechanism is crucial in accurately interpreting the outburst process. In this study, we conducted a series of outburst experiments with different gases, including CO2, N2, and He. We establish that a spallation area can develop spontaneously during CO2 and N2 tests, whereas an outburst caused by He tests (even under stressed conditions) does not produce a spallation area. That is, the spallation area cannot be observed in non-absorbable gas outbursts. We, therefore, focus on the role of coal gas in spallation and propose a viable mechanism to explain its formation. During the outburst development stage, the influence of gas ad-/desorption is critical, as it controls the width of the spallation area and the spallation thickness. In contrast, stress is not a necessary condition. Whether a spallation area will be produced is particularly determined by the generation of a sufficient internal pressure gradient. Moreover, because of gas desorption, the total outburst energy can be increased by 1.84–5.30 times; and the mean outburst propagation velocity and the mean frequency of coal spallation ejected can be enhanced by 0.38–8.76% and 1.28–12.07%, respectively. Consequently, the destructiveness of outbursts depends on the contribution of desorbed gas. [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Industry is the property of Natural Gas Industry Journal Agency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Mechanics & Advanced Technologies is the property of National Technical University of Ukraine KPI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ABSTRACT: This paper provides an overview of the developments in analytical and testing methods and experimental simulations on gas hydrate in China. In the laboratory, the analyses and experiments of gas hydrate can provide useful parameters for hydrate exploration and exploitation. In recent years, modern analytical instruments and techniques, including Laser Raman spectroscopy (Raman), X-ray diffraction (XRD), X-ray computed tomography (X-CT), scanning electron microscope (SEM), nuclear magnetic resonance (NMR) and high pressure differential scanning calorimetry (DSC), were applied in the study of structure, formation mechanisms, phase equilibrium, thermal physical properties and so forth of gas hydrates. The detection technology and time-domain reflectometry (TDR) technique are integrated to the experimental devices to study the physical parameters of gas hydrates, such as the acoustics, resistivity, thermal and mechanical properties. It is believed that the various analytical techniques together with the experimental simulations from large-scale to micro-scale on gas hydrate will play a significant role and provide a powerful support for future gas hydrate researches.

Outburst energy is a major factor influencing coal and gas outbursts, albeit its estimation is difficult owing to the lack of amenable means for quantification of gas desorption. In the past decades, determining the mechanism of outbursts is one of the most challenging issues in rock mechanics. In this study, a triaxial coal and gas outburst simulation system was employed to perform simulated experiments using He (to rule out the influence from gas ad-desorption), N2, and CO2. This facilitated understanding of the energy principle underlying the said outbursts and evaluation of the effects of gas desorption on outburst development. Results of this study indicate that outburst energy and energy consumption are influenced by several factors, including outburst pressure, outburst intensity, ejection distance, and particle size of ejected coal. Among these, gas desorption demonstrates the greatest influence when performing controlled tests (using He). Considering the effects of gas desorption, the total outburst energy can be increased by 1.35–2.95 times, thereby causing an enormous increase in the destructive potential of outbursts. Additionally, values of the coal crushing and transport energies can be enhanced by the order of 118.9–206.6% and 157.8–406.6%, respectively, thereby resulting in a stronger conveying capacity of outburst coal–gas flow along with severe coal fragmentation. A further analysis of the energy distribution indicated that in the development stage, gas desorbed from coal acts as the force driving coal transport, whereas free gas energy is mainly consumed during coal crushing. Findings of this study highlight the importance of quantifying contributions of coal gas towards effective interpretation of outburst-causing mechanisms. [ABSTRACT FROM AUTHOR]

Long‐term multigenerational experimental simulations of climate change on insect pests of economically and socially important crops are crucial to anticipate challenges for feeding humanity in the not‐so‐far future. Mexican bean weevil Zabrotes subfasciatus, is a worldwide pest that attacks the common bean Phaseolus vulgaris seeds, in crops and storage. We designed a long term (i.e., over 10 generations), experimental simulation of climate change by increasing temperature and CO2 air concentration in controlled conditions according to model predictions for 2100. Higher temperature and CO2 concentrations favored pest's egg‐to‐adult development survival, even at high female fecundity. It also induced a reduction of fat storage and increase of protein content but did not alter body size. After 10 generations of simulation, genetic adaptation was detected for total lipid content only, however, other traits showed signs of such process. Future experimental designs and methods similar to ours, are key for studying long‐term effects of climate change through multigenerational experimental designs. [ABSTRACT FROM AUTHOR]

• Calibration and design of test bench simulating experimentally the erosion of solar reflectors. • A uniformity of the received mass is a new parameter introduced. • A function is deduced to predict the required mass to inject in each test configuration. • Effect of sand particles shape is studied and discussed. • Test on solar glass reflectors are carried out and discussed. The main objective of this paper is to design, calibrate and make functional a horizontal test bench used to carry out the experimental simulation of solar reflectors erosion induced by sand particles. The developed equipment provides the possibility to control the air speed, the impact angle between the fluid flow and the target surface as well as the mass rate of the ejected particles. The originality of this work lies on the introduction of a new parameter, identified as, the unified sand mass received by the samples in each test, without considering the experiments conditions (air speed, impact angle, etc.) by acting on the ejected sand mass poured in the sand container. To make the setup operational, a set of calibration tests was conducted under multiple scenarios. The collected data from the calibration tests were analyzed to choose the appropriate configuration. A multiple linear regression function was applied to analyze the influence of the inputs parameters on the tests repeatability. A descriptive equation calculating the amount of sand needed to ensure the unified sand mass, homogeneity and repeatability of the experiments is introduced. The results of erosion simulation carried on solar glass reflectors are also presented; for an air speed of 25 m/s, the reflectance loss is two times greater in 90° (11.03%) than the registered in 45° (5.31%). The developed bench should help researchers to set up their devices for the conduction of advanced experiments ensuring that the obtained results are as repeatable as efficient. [ABSTRACT FROM AUTHOR]

Copyright of Romanian Journal of Civil Engineering / Revista Română de Inginerie Civilă is the property of Matrix Rom and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Four-wheel independent drive electric vehicles have become the latest development trend of electric vehicles due to their simple structure and high control accuracy. Aiming at the sliding problem of four-wheel independent driving electric vehicles in the driving process, a driving anti-skid control strategy is designed. The strategy includes two contents: (1) a road recognition module that tracks the best slip rate in real time; (2) a slip rate control module that uses fuzzy PID control. Then, based on Carsim and MATLAB/Simulink, the vehicle dynamics model, tire model and driving anti-skid control model are established. A simulation of the driving anti-skid control algorithm is carried out to verify the feasibility of the control strategy. Finally, based on the built-up dSPACE semi-physical experimental simulation platform, the verification was carried out, and the test and simulation results were compared to verify the effective feasibility of the driving anti-skid control strategy.