bluuebunny/crossref_metadata_2025 huggingface dataset:
Development and evaluation of authigenic acid system in high-temperature carbonate reservoirs
Authors: Xu Zhipeng , Qi Ning , Zhang Zehui , Han Zizhao , Su Xuhang
Published: May 2021

Acidizing the carbonate reservoirs with the conventional acidizing liquid system always causes fast acid-rock reaction and short acidizing distance, and the productivity of oil wells is not significantly improved. The key to improve the acidizing effect in the deep carbonate reservoirs is to optimize the retardation performance of the acid system. The authigenic acid system provides the excellent retardation performance and long acid-rock reaction due to its characteristics of slow and continuous acid generation. Here, an authigenic acid system with the performance of stable and continuous acid generation at high temperature was developed with halide salt, carbonyl compounds and esters. The authigenic acid system provides the excellent acid generation performance, with 12.9% hydrochloric acid generated after reaction at 90°C for 6 hours and 18.9% hydrochloric acid generated after reaction at 150°C for 6 hours. Comparison of hydrochloric acid, viscous acid and authigenic acid by experiments of static corrosion in rock cores shows the longer acid-rock reaction time of the authigenic acid than that of the conventional acids. At 150°C, N80 steel sheet is corroded in the authigenic acid system at the rate of 0.984 gm·−2·h−1, which is lower than the industrial first-class standard and indicates excellent corrosion inhibition performance. Comparison of the acid-rock reaction kinetic equation of hydrochloric acid, authigenic acid in the carbonate rocks shows that the authigenic acid has the acid-rock reaction rate which is an order of magnitude lower than that of the conventional acid and has the better retardation performance, and it can be used to solve the difficulties in the deep acidizing of high-temperature reservoirs.
Study on the wellbore temperature distribution characteristics during foam drilling
Authors: Zhang Xiaoning , Li Lingdong , Zhang Jianli , Ming Ruiqing , Duan Luyi , Wang Guangtai
Published: May 2021

In view of the specific properties of foam drilling fluids, a wellbore temperature calculation model during foam drilling has been established in this study, considering the Joule-Thomson influence, heat generation by pressure drop of nozzle, frictional heating between drill bit and formation, and frictional heating during foam flow. In addition, the solution of this model is solved by coupling method. Through calculation with examples, the results show that at the shallow well section, the foam temperature in annulus is higher than the formation temperature, and at the deep well section, the foam temperature is lower than the formation temperature. With the increase of liquid injection rate and gas injection rate, the foam temperature in annulus at the downhole and in coiled tube decreases, and the foam temperature in annulus at the wellhead increases. The foam injection temperature has a significant influence on the foam temperature. Increasing the injection temperature can improve the foam stability at the downhole.
High efficiency extraction technology and application of bedding directional long borehole along in Coal Roadway
Authors: Zhu Shikui , Xu Rui , Sun Dongling , Zhang Yongjiang , Cao Jianjun , Niu Xingang
Published: May 2021

In view of the occurrence conditions of coal seam groups in most mining areas in China, the protective layer mining mode is mainly adopted to carry out gas treatment in regional coal seam. In this paper, based on the pressure relief mining of the protective layer, the principle, type and geological conditions of the co-mining mode of the protective layer coal and gas under the condition of coal seam group are analyzed. In Taoyuan Coal Mine, there are some problems such as frequent handling, low efficiency, difficult to control the drilling track, poor drainage effect, etc. The directional long drilling hole is used instead of bottom drainage roadway to reduce the moving time of drilling rig. According to the coal seam characteristics of Taoyuan Coal Mine, the directional drilling rig and other equipment suitable for Taoyuan Coal Mine are selected, and the directional long drilling technology is studied, A total of 13 directional long boreholes have been constructed in the inner section of II 8223 machine roadway, with a total length of 2336m, a lower screen pipe of 2249m, a cumulative coal slag discharge of 480.17t, and an equivalent diameter of 442mm. By January 14, 2020, 78577m3 has been pumped by directional long boreholes, with an average pumping concentration of 15% ~ 100%, and an average net pumping volume of 0.05m3/min ~ 0.40m3/min. It saves the construction of floor drainage roadway, reduces the amount of drilling work for gas control, saves 6 million yuan of gas control investment in the inner section of II 8223 machine roadway, shortens the time for reaching the standard of drainage for 2 ~ 3 months, effectively alleviates the tension of mine production replacement, and realizes safe, economic and efficient mining.
Numerical simulation of gas-water two-phase seepage flow based on level set method
Authors: Zhai Shuo , Geng Shaoyang , Jing Min
Published: May 2021

The mechanism of gas-water two-phase percolation was previously characterized based on percolation experiments. However, the changes in the gas-water interface and the volume fraction of the two phases in the process of gas-water percolation in porous media cannot be accurately described by experiments. This paper uses core casting thin sections and AutoCAD software to establish a digital core. Based on the idea of level set, a two-dimensional gas-water seepage model in microscopic pores is established. The finite element numerical simulation software is used to solve the model to describe the gas. The changes of the water two-phase interface are visually displayed. At the same time, Darcy’s law is used to compare the relative permeability curve obtained from the gas-water two-phase seepage experiment with the relative permeability curve obtained from the gas-water two-phase seepage finite element simulation. The results show that the gas-water two-phase seepage experiment and the gas-water two-phase seepage finite element numerical simulation have basically the same characterization of the seepage ability of porous media. There is obvious fingering phenomenon in the process of gas flooding, and the gas preferentially passes through the large pore throat. The smaller the pore throat, the greater the velocity of gas passing through the pore throat. The gas-water two-phase interface change described by the numerical simulation of the gas-water two-phase flow based on the digital core is more reliable.
Study on Open-pit Mine Slope Stability Based on Improved TOPSIS Method
Authors: Sun Zhongqi , Li Jiangteng
Published: May 2021

In order to evaluate the slope instability risk of open-pit mine more accurately, this paper establishes a slope instability risk evaluation model based on Improved TOPSIS method according to the hierarchical holographic modeling method and entropy method. In this paper, the hierarchical holographic modeling method is used to establish the evaluation index system of open-pit slope stability, and 11 main indexes which have great influence on the stability are selected. The weights of 11 main indexes are calculated by using entropy method, and then applied to TOPSIS method. Finally, the positive and ideal solution distances of 5 typical open-pit slopes are calculated and the destabilization risk of 5 open-pit slopes is reasonably evaluated. The evaluation results were compared with those of other evaluation models to verify their rationality. The results show that the slope evaluation method based on improved TOPSIS can effectively evaluate the slope stability, which provides a new method for determining the high risk slope and effectively rating the slope risk.
Research of Reinforcement Deployment Mechanism of Automatic Sampler for Lunar Sample Return Mission
Authors: Liu Deyun , Zeng Ting , Wang Lusi , Mo Guidong , Li Jun , Sun Qichen , Gong Junshan
Published: May 2021

Chang’E-5 detector has successfully completed the lunar sample return mission, and accomplished the first extraterrestrial object drilling sampling detection of China. The deploying process is a key point for the whole mission and the design of the deployment mechanism is significantly important for the system. Compared to traditional deployment, low gravity surface operation and heavy load is the characteristics of this mission. In this paper, a design of reinforcement deployment mechanism suitable for lunar low gravity environment, large load condition is proposed. In this scheme, the planetary force augmentation and fulcrum separation method is adopted, the arm of force is introduced to achieve large load driving by small torque, and the design parameters are determined. The performance of the deployment mechanism is vindicated by dynamic simulation analysis and experimental verification. The research results demonstrate that the deployment mechanism can meet the demand of driving large load with small torque. The deployment mechanism designed based on this scheme has been employed by Chang’E-5 detector and performed perfectly on the moon.
Research on Application of Lattice Anchor System Design and Construction Monitoring in Slope Protection
Authors: Li Jianhua , Hu Da , Li Lianguo , Li Chungang
Published: May 2021

This article focuses on the application of lattice anchor system in high slope protection. According to the engineering geological characteristics of the slope of the site, combined with the requirements of the layout of the slope of the site, the slope is permanently supported by the combined support system of lattice anchor rods, nets, and soil spray. The example takes the slope under the arc failure mode as the research object to carry out the parameter design calculation, and conducts real-time monitoring during and after the construction. Calculation and monitoring analysis show that it is feasible for concrete lattice anchor system to be used in slope reinforcement projects, and the stable bearing capacity of lattice anchor system is higher, which has higher construction safety and better effect.
Study on the Characteristics of Underground Space in Wulong, Chongqing
Authors: Li Wei , Zhang Ruigang , Chen Fei , Zhou Dan , Liu Zhen
Published: May 2021

Comprehensive study of urban underground space status, efficiently configuring urban underground space resources to serve urban construction. This article selects the integrated analytical system of two levels of engineering geology, hydrological geology, environmental geology and human activities, and draws the weight value of the factor factor weight and the corresponding layer superimposed by one item by item. Sexual distribution. Choosing Chongqing Wulong is a research area, constructs 4 first-level indicators and 11 secondary indicators comprehensive evaluation system, and the factor weight value and adaptation map shows that Wulong Research Area should focus on environmental geological conditions, urban underground space division 3 A total of 12 pieces of zones, and the evaluation results can provide reference for the construction of Wulong city.
Identification of Interlayer Distribution of Marine Sandstone Based on Four-dimensional Well Test Technology
Authors: Li Ke , Li Yao , Zhang Peng , Wang Kai , Tang Chenyang , Tang Jing
Published: May 2021

Reservoir compartment is one of the important influence factors of fluid flow in the reservoir, and it is of great significance to carry out the research on reservoir compartment understanding and characterization for the research and development of residual oil distribution in the middle and late stages of an oil field. However, how the reservoir compartment is distributed, the current method is mainly throughout open heads, rock hearts, logging, and other information to explain, but this method is limited to blocks. Because of this problem, we use the four-dimensional test well method to calculate the distribution of the oil deposit formation coefficient based on the test well pressure data, and then use pressure denoising technology to make the data smoother, and the resulting two-pair curve plate is clearer, the layout can be used to explain the distribution of the compartments in the work area. This method requires only test pressure data and is suitable for multiple workspaces. This is of great guiding significance to the development of sea-phase sandstone inter-layer reservoirs.
Research on the Forecast Means of Large-Scale Multi-Branch Fracturing Capacity
Authors: Jiandong Liu
Published: May 2021

In order to effectively improve the economic benefits of large-scale fracturing of the single well in tight reservoirs, avoid investment risks and raise development effects, research on the forecast means of large-scale multi-branch fracturing capacity is carried out. Large-scale fracturing has high costs and high investment risks, it is necessary to conduct relatively accurate forecast for the capacity after fracturing to reduce investment risks. On the basis of the single-well capacity data of 78 large-scale fracturing wells that have been put into production in the Hailar Basin, the geological, development and engineering factors affecting capacity were deeply analyzed and summarized. According to different applicable conditions, the theoretical derivation and polynomial linear regression methods are used; two different capacity forecast models of tight reservoir are given. These two forecast models are used, the error of capacity forecast results after fracturing is less than 15%, and the accuracy can meet the actual application requirements of the mine, therefore, this forecast method provides a powerful technical support for the promotion of large-scale fracturing technology and reducing economic risks.
Effects of long-term sand mixing ameliorating measures on soil salinity characteristics of saline-alkali land in northern Shaanxi
Authors: He Lirong , Luo Yuhu
Published: May 2021

To explore different mix sand measures of saline-alkali land improvement effect for a long time, this study in northern shaanxi dingbian county saline-alkali soil as the research object, combined with field experiment and indoor test methods in the wild, analysis and improvement of saline-alkali soil salt and 1 ~ 6 years change characteristics of organic matter, reveal different mix sand thickness of heavy saline-alkali soil salt content and organic matter distribution. The results showed that the overall soil salt content in saline-alkali land did not change regularly with the change of sediment mixing amount or improvement years. There is no significant difference between different thickness (proportion) sand mixing measures on saline-alkali land improvement benefits. As time goes by, the soil salt content in the whole soil layer of saline-alkali land is not significantly changed by sand mixing treatment, but the soil salt content in arable layer is decreasing year by year, and the improvement benefit is significant in the short term. In conclusion, the long-term sand mixing improvement measures are beneficial to the improvement of the cultivated layer of saline-alkali land, thus reducing the salt damage suffered by crops in the process of growth and development, etc., the effects of sand mixing treatment on soil microorganisms and enzyme activities remain to be further explored.
Study on the relationship between well pattern and artificial fracture configuration in tight reservoir
Authors: Zhang Qingchao
Published: May 2021

In order to summarize the relationship between reasonably well pattern and artificial fracture in Fuyu reservoir which using the vertical well development, we determined the fracture network scale of overlay channel and a single channel sand body on the basis of the fracture network fracturing test and the downhole microseismic fracture monitoring data and annulus testing data. The reasonable fracture network sizes of different sand bodies were obtained by establishing a typical well fracture-matrix model and applying numerical simulation of the production of 16 different fracture networks in 5 years. Under the premise of established reasonable scale of the fracture network, it provides reference for the reasonably well pattern in the new area with similar reserves in geological conditions by the comparing of the 5-year oil production in 6 different well spacing.
Development status and trend analysis of anti-icing semisubmersible drilling platform
Authors: Yang Hu , Li Zhuo , Zhu Chenghua
Published: May 2021

In order to speed up the development of Arctic resources, it is the focus of polar drilling equipment research and development to develop a new anti-ice drilling platform which adapts to the harsh environment of polar regions and reduces the construction and operation costs. By briefly analyzing the structure of the existing antiice drilling platform, the design points of the anti-ice semi-submersible drilling platform are obtained, and the development status of the anti-ice semi-submersible drilling platform is analyzed. Finally, the development trend of the anti-ice semi-submersible drilling platform structure is summarized.
Research Progress on Vegetation Ecological Restoration of Abandoned Land in Coal Mine Area
Authors: Ye Shenglan
Published: May 2021

The large-scale mining of coal mines produces a large amount of abandoned idle land, which seriously damages the ecological environment and causes severe environmental pollution. Among them, waste coal gangue takes up a lot of land. A large number of abandoned land remediation and restoration in coal mining areas have also been carried out at home and abroad. Among them, vegetation ecological restoration has special advantages in the restoration of coal gangue abandoned land. Therefore, this paper analyzes the characteristics of coal gangue wasteland and the feasibility of plant growth, discusses the methods and application progress of vegetation restoration, and proposes prospects for the future research work on the restoration and utilization of wasteland in coal mining areas.
Research on the Impact of Income Gap on Environmental Pollution Based on Balanced Panel Data of 48 Countries
Authors: Luo Li , Ma Xiaoming
Published: May 2021

Reconciling economic development with ecological environmental protection has always been a hot issue of the whole society. However, existing studies only consider the impact of per capita income on environmental pollution, while ignoring the existence of income gap and its possible impact on environmental pollution. Therefore, the paper focuses on the specific analysis of the relationship between income gap and environmental pollution in 48 countries and revising the EKC theory. The empirical analysis results show that: there is an M-shaped relationship between the income gap and the per-capita carbon emissions, and the three turning points are 0.27, 0.36 and 0.52; there is an N-shaped relationship between the per-capita income and the per-capita carbon emissions, and the two turning points are 5218.65 and 13766.50 international dollars; the per-capita carbon emissions increases significantly as the per-capita energy consumption increases; and there is a significant negative relationship between the urbanization rate and the per-capita carbon emissions, which provide theoretical reference for the government to formulate corresponding policy measures.
Investigation, Evaluation and Countermeasures of Flood Disaster in Rural Grassroots in Plain Area
Authors: Guangming He , Hou Xiangdong , Liu Xiangjun , Wang Xunshi , Zhang You , Wang Weilin
Published: May 2021

In view of the complex causes of flood disasters at the grass-roots level in the plains and the difficulty of defense, this study proposes a point-to-surface flood disaster survey and evaluation method in the plains: First, the villages in the plains are divided into low-lying villages based on the causes of the disaster. And the villages affected by river floods; secondly, the two types of villages are used as the unit to investigate the basic situation of village flood disasters, starting from the three-level flood control and drainage system of the drainage system in the village, the main drainage canal outside the village, and the middle and small rivers to complete the investigation of the flood disaster; The calculation methods of the village’s critical rainfall index, critical rainfall index and river flood control capacity are put forward to quantitatively assess the village’s flood disaster risk and engineering flood control and drainage capacity; finally, corresponding countermeasures are proposed from the engineering and non-engineering perspectives based on the investigation situation, which is for plain areas. Flood disaster prevention work provides a reference.
Research on Lightweight Convolutional Neural Network in Garbage Classification
Authors: Yaqing Gu , Ge Bing
Published: May 2021

With the rapid development of society, more and more garbage consumables are produced. How to better recycle and use “garbage” has become a widespread concern. In this paper, a lightweight garbage classification model (GroupAtten_ MobileNet, GA_MobileNet) is designed based on the convolutional neural network ResNet-50. Reduce the amount of Params, FLOPs and memory consumption by using deep convolution and group convolution; use the channel attention mechanism to increase the accuracy of the model; Use the model fine-tuning method to further reduce the model’s Params, FLOPs, and memory consumption. This paper divides the recyclable garbage into 6 categories. Through an experimental comparison on the garbage data set, it is found that the amount of GA_MobileNet Params proposed in this paper is 280 times less than ResNet-50; the FLOPs amount is reduced by 31.7 times; the accuracy rate Increased by about 3.1%; operating time reduced by 50%;At the same time, compared with the same type of lightweight models Mobile Netv 2, Squeeze Net and shuffle Net V1 also has a clear advantage. Finally, it is concluded that GA_MobileNet is a garbage classification model suitable for lightweight convolutional neural networks, which is suitable for recycling of garbage, protecting the environment and benefiting the country and the people.
Research on the Diffusion of Harmful Gases from Ships Based on Gaussian Plume Model
Authors: Qin Cuihong , Zhang Wei , Wang Zheng
Published: May 2021

After a harmful gas diffusion accident occurs on ships, grasping the harmful gas diffusion behavior and possible impact range is the key to emergency rescue. In this paper, a Gaussian plume model is used to construct a simulation system for the diffusion of harmful gases from ships, and four comparative experiments are designed. The simulation is realized based on MATLAB platform programming. Under the conditions of different geographical locations, time periods and meteorological conditions when the accident occurs, the distribution of harmful gas diffusion concentration and the range of influence are analyzed. This work may provide a scientific basis for evacuation and emergency response plan formulation in the water area surrounding the accident.
An Empirical Analysis of the Impact of Environmental Decentralization on Environmental Governance in China
Authors: Pan Xiaoli , Ma Xiaoming
Published: May 2021

Environmental problems are particularly prominent in the context of carbon neutrality. The root cause of the environmental dilemma lies in the system. Therefore, this article discusses whether China is an environmental federalist country based on the perspective of environmental management system changes, and portrays China based on the two dimensions of environmental management system and fiscal decentralization. Changes in the system of environmental decentralization. With the help of environmental affairs responsibilities, the overall environmental decentralization is divided into administrative decentralization, monitoring decentralization, and supervision decentralization. The number of environmental protection agencies and the coverage of environmental protection agencies are used to calculate the Chinese-style environmental decentralization index during 1993-2015. The current environment in the western region Decentralization is still at a relatively low level. Through empirical analysis, the results show that the level of environmental governance is negatively correlated with environmental decentralization, which reflects the strengthening of the degree of centralization under the framework of environmental decentralization in China, such as the implementation of vertical management reform of environmental protection agencies, which will further improve local governments. Environmental governance level.
Research on global carbon emission flow and unequal environmental exchanges among regions
Authors: Guo Lixia , Ma Xiaoming
Published: May 2021

Global carbon emissions have become a huge problem, which greatly accelerates the process of global warming. However, the flow and exchange of carbon emissions caused by international trade has further increased the difficulty of determining carbon emissions responsibilities and advancing world’s emission reductions. Based on the multi-regional input-output (MRIO) model, this study analysed the flow and outsourcing of carbon emissions among six regions of the world in 2014, and applied the regional environmental inequality (REI) index to measure the unequal environmental exchanges among regions. We found that global carbon emissions reached nearly 35Gt, of which more than 20% were outsourced to other regions. Especially developed regions, such as EU 28, USA and Japan, had significantly higher consumption-based carbon emissions than production-based carbon emissions. The unequal environmental exchanges mainly occurred between developed regions and underdeveloped regions. This paper can help to distinguish emission responsibilities of various regions of the world, and contribute to world emission reduction policies.
Research on Dispatch Optimization of Self-owned Power Plant under High New Energy Penetration
Authors: Chen Zhenhuan , Yang Zan , Yang Chunxiang , Zhang Bolin , Zhang Tianrui , Zhang Tianyu
Published: May 2021

Considering that self-owned power plant (SPP) can accommodate more new energy generation, this paper proposes a joint dispatch optimization method of SPP. First, two market patterns of SPP considering its load characteristics were established. Then, a self-optimization model of SPP was built with the goal of minimizing SPP operating costs, and a joint optimization model of both SPP and the grid was constructed with the goal of minimizing total system operating costs which comprehensively considered the constraints of SPP interests, unit generation capacity, new energy accommodation requirement and grid security in optimizing the output of SPP and grid-connected units. Next, the optimization models were solved by NSGA-II algorithm. Finally, a comparative case-study on the two models was carried out, and the results showed that SPP can help to accommodate more new energy and reduce system operating costs.
Analysis of Electrical Parameters of Generator Motor No-load Operation Fault
Authors: Shen Yubo , Zhou Hongyi , Han Siwei , Li Zhibin , Zhou Meng , Kong Fanrong , Zhao Xiangyu , Yao Xuyang
Published: May 2021

In the context of my country’s full effort to build pumped storage power stations, my country has the ability to independently research and develop pumped storage power stations, and has set a development goal to manufacture pumped storage units with larger single-unit capacity and higher speed. Generator motors play an important role in the safe and stable operation of power systems, and have a significant impact on power grids and power stations. This paper establishes a physical model of the damping winding of the generator motor, simulates the change of electrical parameters when a short-circuit fault occurs in the no-load operation of the generator motor, and obtains and analyzes the change rule, which has great theoretical and practical significance.
Research on multi-objective optimal scheduling strategy of photovoltaic and energy storage based on dynamic programming
Authors: Liu Hanghang , Wang Yuanyuan , Liu Sentao , Liu Qi , Xie Yun , Ma Xiaoyi
Published: May 2021

The multi-objective model of the electric vehicle and wind power in the load control is established, which stabilizes the peak and valley difference of load and electric vehicle charging and discharging cost. Considering the electric vehicle battery available capacity and charge discharge power constraints, as well as the genetic algorithm for nonlinear programming, this paper analyzes the influence of peak load difference on stabilizing the load fluctuation and improving the return of electric vehicle users. Finally, through the example analysis results show that the multi-objective model can be more optimized through the reasonable price in the electric vehicle charging and discharging and genetic algorithm for nonlinear programming and considering the peak and valley load difference, and the results curve is presented.
Concept and Key Technology Analysis of Electric Pump-Fed Liquid Propellant Rocket Engine
Authors: Liu Yang , Yang Jiangang , He Yuanbo , Ni Zheng , Wu Yue
Published: May 2021

Electric pump-fed liquid propellant rocket engine is an engine that uses electric pumps for propellant supply and cooling cycle. The engine breaks through the traditional pressurization mode of using inert gas to squeeze the propellant or gas-driven turbo pump, and has the advantages of simple system, light structure, high reliability and easy implementation of thrust adjustment. This study introduces the composition, working principle and technical advantages of the electric pump-fed liquid propellant rocket engine, evaluates the factors affecting the mass of the supply system with sensitivity analysis method, and analyses the key technologies of the electric pump-fed rocket engine.
Challenges with the Ultimate Energy Density with Li-ion Batteries
Authors: Fang Haoyu
Published: May 2021

Challenges with the energy density with Li-ion batteries are reviewed. At present, Li-ion batteries are widely used in electronic equipment and electric vehicles, but the energy density is not high. It is important to find out the limitations of the energy density with Li-ion batteries. This essay will start the research with the structure of Li-ion batteries, study the chemistry behind Li-ion batteries and give a summary of the limitations of each battery part which affect energy density. In conclusion, it is the chemistry behind batteries that limits the energy density.
Similarity criteria and scale effect for physical simulation of coal and gas outburst
Authors: Che Yuheng
Published: May 2021

Based on the dimensional unity, analyzed mechanics, adsorption, desorption and seepage characteristics in the process of outburst by equation analysis method. Combining the existing experimental condition, proposed similarity model which could be more similar to practice and theory, and researched scale effect of outburst physical simulation. Analyzed the geometry size influences release area size, elastic energy, gas energy, broken power and throwing power in the process of outburst. Improved similar material of coal and gas outburst, considering seepage characteristic. The results show that realizing the consistency of the stress ratio scale and the gas pressure ratio is the key in the outburst similarity model. Scale effect plays an important role in the occurrence and development of outburst. In terms of energy contribution, gas can contribute more energy to outburst than elastic energy. Refer to energy dissipation, broken work is more than 95 % in outburst energy, and throwing work is only a small part in outburst energy.
Mechanical response and energy dissipation characteristics of granite under low velocity cyclic impact
Authors: Hu Nan , Li Changhong , Xiao Yonggang , Hou Zhiqiang , Qiao Chen
Published: May 2021

In the process of metal ore blasting mining, the surrounding rock in the middle and far area will still be affected by the stress wave generated by the explosion, resulting in the damage and strength reduction of surrounding rock. The fracture process of rock under cyclic impact load is a process of energy absorption and dissipation. The research on the mechanical properties and energy dissipation law of surrounding rock under low velocity cyclic impact has a good reference for the research on the damage law of rock under weak impact environment. In this paper, the granite samples collected from Sanshandao Gold Mine in Laizhou City, Shandong Province were subjected to cyclic impact tests by using a 50 mm diameter split Hopkinson pressure bar (SHPB) test device. The stress-strain evolution law and energy dissipation law of the specimen in the process of damage and fracture are mainly studied. The results show that the dynamic process of a large number of void defects (such as voids, dislocations, microcracks, etc.) in granite under cyclic impact load is strengthened, and the damaged core is formed and propagated, leading to tensile fracture; With the accumulation of strain energy, the damage situation intensifies, and then affects the stress propagation, so that the ratio of incident energy to reflected energy increases linearly with the accumulation of strain energy, and the ratio of transmitted energy also decreases linearly.
Research Progress on the Law of Nitrogen Transfer and Transformation in Sediment
Authors: Ye Shenglan , Shu Xiaoxiao , Xie Xiao
Published: May 2021

The eutrophication of closed and semi-closed landscape water bodies such as lakes and rivers is one of the typical environmental problems in cities. The bottom sludge formed under long-term eutrophic water is prone to re-release of nitrogen and phosphorus elements and cause secondary pollution. While effectively intercepting and controlling external pollution, attention should be paid to the secondary release of internal pollutants. Analyzing the nitrogen exchange of eutrophic sediments in sediments-overlying water-plants and the release of internal nitrogen in sediments is conducive to the wider application and promotion of plant ecological restoration technology in sewage treatment projects.
Removal of Nitrate from Wastewater with Polymer-Enhanced Ultrafiltration (PEUF)
Authors: Li Xue , He Li , Liao Xingsheng , Song Yuhao , Huang Chaoguang , Luo Kun , Pang Ya
Published: May 2021

Polymer-enhanced ultrafiltration (PEUF) is an advanced technology for the efficient separation of heavy metal ions and organic matter from outlet water. The removal of nitrate ions from wastewater via PEUF was investigated using polyethyleneimine(PEI) and cationic polyacrylamide(CPAM). When the concentration of NO3
- was 20 mg/L, the dosage of PEI/CPAM was 0.1 wt%, the best rejection were obtained, rejection of NO3
- were 92.8% and 80.2%, respectively, and rejection of PEI and CPAM were 92.3% and 83.3%, respectively. Effect of pH value on NO3
- rejection was obvious, rejection of NO3
- decreased sharply with the increase of pH value. However, there was no obvious changes on the PEI rejection. The PEUF process was considered to be more suitable for nitrate rejection using PEI as a polymer reagent.
Calculation and analysis of the amount of secondary component products of NOXand SO2on metal oxide surface based on Drifts simulation: A case study of vehicle exhausts emission
Authors: Jia Lijun , Liang bo , Li Cheng , Zhu Kai , Han Wenye , Guan Jie , Gao Guilan , Li Yingjie
Published: May 2021

In this paper, the micro reactions of SO2and NOxin the metal oxides (Fe2O3, MgO, MnO2, Al2O3, ZnO, Cuo, SiO2and Cr2O3) from vehicle exhaust are studied by diffuse reflectance infrared spectroscopy (DRIFTS). The amount of secondary component in PM2.5is analyzed by observing the synergistic or antagonistic effects of different gases on the surface of different metal oxides. The results show that when SO2and NO2coexist, the formation of sulfate is greatly promoted on the surface of Fe2O3metal particles, and the intermediate sulfite is formed at the initial stage and then rapidly oxidized to sulfate. Under the condition of oxygen enrichment, the total species content of secondary components of fine particles formed on the surface of metal oxides is Cr2O3> Fe2O3> MgO > MnO2> Al2O3> ZnO > CuO > SiO2. because Cr2O3has a strong ability to adsorb and activate acid gas, so the content of surface species generated in the micro reaction is more than that of other metal oxides; the metal oxides containing iron, magnesium and manganese can more effectively convert SO2into sulfate in the presence of NOx, but the sulfate generated on the surface of Cr2O3, CuO and Al2O3decreases, which leads to the difference of metal oxide activity It is caused by the change of metal surface properties. This result has a certain guiding significance for the reaction of SO2and NOxto metal oxides emitted by motor vehicles in the atmosphere.
Enhancing the Production of Bioplastics for Sustainable Recycling and Biodegradation-Short Review
Authors: Abioye Abiodun A. , Afolalu Sunday A. , Yusuf Omolola O. , Emetere Moses E. , Ongbali Samson O. , Arubayi Ofome C , Imade Kenneth I. , Olayinka Ayotunde
Published: May 2021

The shift from the production and utilization of synthetic non-plastics to bio-based plastics is on the high side. To curb the environmental nuisances, the synthetic plastics have presented over time. Consequently, it is required to consider some factors that can be manipulated or adjusted to facilitate the biodegradation process. The factors that determine the rate of biodegradation of bio-based and fossil-based plastic and the features of biodegradable plastics are highlighted in this review. This is projected to secure a sustainable bio-plastic synthesis and catalyze bio-recycling and biodegradation strategies.
Recent Advancements in the Development of Nanofluid Technology in Heat Transfer Applications
Authors: Oyeleke O.O. , Ohunakin O.S. , Adelekan D.S. , Atiba O.E. , Nkiko M.O. , Jatinder G.
Published: May 2021

The development of nanofluid technology has created a niche and instigated a new area of novel researches into the enhancement of heat transmittance and transport properties of conventional working fluids with various nanoparticle types in various heat exchange applications, due to the poor thermal performance of conventional fluids. From the development of single nanofluids, to hybrid nanofluids, to the use of surface active agents and stabilizers in ensuring homogenous dispersion and chemical stability, to the use of turbulence promoters with nanofluid, all these were presented as novel developments arising from continuous investigations and study into the heat enhancement performance of different nanoparticle morphology, size, volumetric concentration etc. Thus the subject of this review work is to provide a key insight into the recent advances in the development and utilization of nanotechnology in enhancing heat transfer and transport properties by summarizing progress in the made in the development of nanofluids for the last five years.
Hydrophobic Nanoparticles-Silica from Natural Sands with TMCS as Media
Authors: Munasir  , Safitri Irna Indah
Published: May 2021

The purpose of this research is to synthesize hydrophobic silica nanoparticles (NPS). Modified mixtures of trimethylchlorosilane (TMCS) and NPS are the focus of the analysis of the nature of hydrophobicity. 0.5g of silicon dioxide (SiO2) powder was mixed with TMCS, then coated on a glass substrate using the spin-coating method. Furthermore, the glass was put in a heating oven for one hour, at 65°C. In addition to the hydrophobicity test, morphological analyses using SEM (scanning electron microscopy) were also carried out. The contact angle of 115.6° indicates a hydrophobic nature. The presence of homogeneous NPS SiO2 in the TMCS solution affects the hydrophobic quality of glass surfaces coated with NPS.
Book-Share (BS) Apps using the Android System
Authors: Latif A , Marsujitullah  , Letsoin S M A , Budiasto J
Published: May 2021

Information technologies including information systems play an important role to support education systems specifically in remote area such as Papua. However, based on World’s most literate Nations (WMLN) study found that Indonesia is the second-least literate nation in the World. This study focuses on the empowering of open source android software to facilitate students or teachers to borrow, share or exchange books. The system consists of two modules, i.e. the Backend as a Service (BaaS) is obtained through firebase web service, and client android system. The findings may be helpful for both borrowers and owners using this application in selecting, borrowing, reviewing, applying, adding book profile, and viewing. To end this, the application also able in displaying maps and routes, private messages as well as notification.
Assessing The Quality of Lapors! Using E-Govqual Theory in User’s Perspective
Authors: Safitri E. M. , Suryanto T.L.M. , Faroqi A. , Mukhlis I.R.
Published: May 2021

LAPOR! Is an e-govemment project that is used to manage the aspirations and complaints of the Indonesian people with online system. This information system is expected to minimize the gap between citizens and the government in carrying out various aspects of government. According to the results of a survey conducted by the Indonesian Internet Service Providers Association (APJII) in 2017 LAPOR!’s users still around 0.2% of the total population of Indonesia, 143.26 million. Applications that were booming in 2013-2014 are now neglected in 2019. In addition to the policy changes that underpin the implementation of the information system, LAPOR! declared not as effective and efficient as before. Complaints about public services in LAPOR! now many are neglected and the follow-up is not as intensive as it once was under the supervision of UKP4. The application of a service-based information system requires continuous measurement of an information system evaluation. The measurement results are needed to overhaul the better implementation steps. This study uses an e-govqual approach with quantitative methods that are supported by qualitative data. Quantitative methods were carried out using SPSS 24 and Smart PLS 3. Qualitative data used were interviews with several key informants. The results of this study found that the biggest key to success in implementing LAPOR! is the content and appearance of Information factor.
Decision Tree C 4.5 Algorithm for Classification of Poor Family Scholarship Recipients
Authors: Kustiyahningsih Y , Khotimah B K , Anamisa D R , Yusuf M , Rahayu T , Purnama J
Published: May 2021

The poor family scholarship program is a scholarship program by Lamongan District Education Office. This scholarship is given to underprivileged students for study costs at university. The many indicators of scholarship determination result in difficulties education office in making objective decisions. The purpose is to determine the classification of scholarship recipients using the decision tree C4.5 algorithm. This algorithm has the advantage of speed informing and reading models, high accuracy, flexibility, and processing discrete and continuous data. The contribution of this research is to classify poor family scholarship participants with the C 4.5 algorithm without pruning, pre pruning, and post pruning methods. This study uses 460 data and for each attribute, it is calculated using the gain ratio formula to produce trees and decision rules. Based on the scenario that has been done the accuracy value generated after pruning is better than without pruning. The classification process using scenario post pruning technique is used as a reference for the classification of new registrants because it has the highest accuracy of 85.55%.
xtended Technology Acceptance Model (TAM) for “Desa Digital” Mobile Application Users: A Literature Study
Authors: As’adi M , Dewi A C , Andy R , Zaman A N
Published: May 2021

The sustainability of Industry 4.0 has now entered into the tourism sector or Tourism 4.0. However, the existence of information technology as a provider has not been widely used in the context of Tourism 4.0 in Indonesia. Recent mobile technology, the application namely “Desa Digital” requires an in-depth evaluation of an intention to use and actual system usage. Hence, this study uses a Technology Acceptance Model (TAM) to understand the intention to use and actual system usage for “Desa Digital” mobile application users in Indonesia. A literature study is conducted in identifying variables that are important on the acceptance model. Furthermore, this paper identifies social presence, perceived enjoyment, perceived ease of use, perceived usefulness, perceived compatibility, and attitude toward use influencing intention to use and actual system usage.
Mobile Support in Ubiquitous Learning Systems
Authors: Amaliyah Yuli , Widat Faizatul , Zamroni  , Agusmiati Sinta , Sa’diyah Hasan Halimatus , Hindia Maimunatul , Utami Alfania Diah
Published: May 2021

The very rapid development of technology requires us to keep pace with the times as it develops. These technological advances have made everything more modern, practical and efficient. This study aims to determine our perceptions of the use of mobile devices as a learning system. The existence of this mobile device makes the learning system more practical, besides that it can also be used anywhere. This research uses a qualitative approach with case studies. The results showed that: the impact of mobile devices is very influential and helps a lot in the learning system, the learning process becomes easier, and also broad. Through mobile devices students are easier to memorize and can be done at any time and can be applied everywhere.
THD Analysis on a Single Phase 7-Level Diode Clamped MLI with LC Filter Based on Multicarrier Anti-Phase SPWM Technique
Authors: Rusdi Muhamad , Ponadi Acep , Hardiantono Damis , Haryanto Sumbung Frederik
Published: May 2021

Inverter is an electronic device which is an important part to convert DC-AC energy. Increased use of renewable energy as a substitute for fossil energy that is running low encourages the increased performance of the inverter. Multilevel inverter offer many advantages for improving the performance of an inverter system. Diode Clamped Multilevel Inverter are explored with 7-level circuits that are analyzed and simulated specifically on the quality of the output ie the amount of harmony. The power switch control technique uses Anti-Phase SPWM with multicarrier. Further to maximize damping harmonics, LC filter is applied and researched. This research is using PSpice A / D Lite to simulate a system that worked. The results obtained harmonic attenuation reached 3.93% after LC filter.
Optimum Distance Planning of Wireless Sensor Network Using Linear Regression Method
Authors: Ubaidillah Achmad , Alfita Riza , Shoiman Wahyudi Mohammad
Published: May 2021

This research is very important to know the performance and capability of ESP-01 as a sensor node in network planning using Wireless Sensor Network (WSN). The optimal distance between nodes is obtained from the recording using the wireshark application. The linear regression method is used to build distance forecasting systems with packet loss and delay metrics. Observation is done by simulation using Network Simulator and direct measurement using wireshark. The results showed that the recommended optimal distance is 34 meters with a good category network quality.