Problem Of Low Utilization Rate Research Articles

Numerical Simulation Study on The Ultimate Water Head of Artificial Dam in Coal Mine Underground Reservoir

In order to improve the problem of low utilization rate of groundwater in the process of coal mine production, some mining areas in northwest China use the goaf of the working face as a water storage space, and establish underground reservoirs to realize water retention mining. In order to solve the problem of the stability of the artificial dam of the underground reservoir, this paper takes the underground reservoir of the 51103 working face of Guojiawan Coal Mine as the engineering background, and uses the FLAC3D numerical simulation software to establish the artificial dam model, and the experimental results show that when the head height is 26m, the maximum tensile stress inside the dam is 1.264MPa, which is still lower than the limit of the tensile strength of the concrete, until the water pressure increases to 27m, the maximum tensile stress inside the dam is 1.290MPa, which is greater than the limit of the tensile strength of the concrete, so the ultimate head height of the artificial dam is 26m.

Insights into hydrophobic (meth)acrylate polymers as coating for slow-release fertilizers reduce nutrients leaching

To solve the problem of low utilization rate of conventional fast water-soluble release fertilizers and to minimize their negative impact on the environment, slow-release fertilizers (SRF) have emerged as sustainable...

Design optimization and experiment of corn U-shaped fertilization device

Aiming at the problems of low utilization rate of corn fertilizer, low precision of fertilization ratio, and time-consuming and laborious topdressing in the later stage, an U-shaped fertilization device with uniform fertilizer mechanism was designed. The device was mainly composed of uniform fertilizer mixing mechanism, fertilizer guide plate and fertilization plate. Compound fertilizer was applied on both sides and slow/controlled release fertilizer was applied at the bottom to form an U-shaped distribution of fertilizer around corn seeds. Through theoretical analysis and calculation, the structural parameters of the fertilization device were determined. Through the simulated soil tank test, the quadratic regression orthogonal rotation combination design was carried out on the main factors affecting the spatial stratification effect of fertilizer. The optimal parameters were obtained as follows: the stirring speed of the stirring structure was 300 r/min, the bending angle of the fertilization tube was 165°, and the operating speed of the fertilization device was 3 km/h. The results of bench verification test showed that under the optimized stirring speed and bending angle, the fertilizer particles were stirred evenly, and the average values of fertilizer flowing out of the fertilization tubes on both sides were 299.5 g and 297.4 g, respectively. The average fertilizer amounts of the three fertilizer outlets were 200.4 g, 203.2 g and 197.7 g, respectively, which met the agronomic requirements of 1:1:1 fertilization, and the variation coefficients of fertilizer amounts on both sides of the fertilizer pipe and each layer were less than 0.1% and 0.4%, respectively. The simulation results of the optimized U-shaped fertilization device can achieve the expected U-shaped fertilization effect around corn seeds. The results of field experiment showed that the U-shaped fertilization device could realize the U-shaped proportional application of fertilizer in soil. The distance between the upper end of fertilization on both sides and the distance between the base fertilizer and the surface were 87.3–95.2 mm and 197.8–206.0 mm, respectively. The transverse distance between the fertilizers on both sides was 84.3–99.4 mm, and the error with the designed theoretical fertilization was within 10 mm. Compared with the traditional side fertilization method, the number of corn roots increased by 5–6, the root length increased by 30–40 mm, and the yield increased by 9.9–14.8%.

Optimization of Apron Support Vehicle Operation Scheduling Based on Multi-Layer Coding Genetic Algorithm

Operation scheduling of apron support vehicles is an important factor affecting aircraft support capability. However, at present, the traditional support methods have the problems of low utilization rate of support vehicles and low support efficiency in multi-aircraft support. In this paper, a vehicle scheduling model is constructed, and a multi-layer coding genetic algorithm is designed to solve the vehicle scheduling problem. In this paper, the apron support vehicle operation scheduling problem is regarded as a Resource-Constrained Project Scheduling Problem (RCPSP), and the support vehicles and their support procedures are adjusted via the sequential sorting method to achieve the optimization goals of shortening the support time and improving the vehicle utilization rate. Based on a specific example, the job scheduling before and after the optimization of the number of support vehicles is simulated using a multi-layer coding genetic algorithm. The results show that compared with the traditional support scheme, the vehicle scheduling time optimized via the multi-layer coding genetic algorithm is obviously shortened; after the number of vehicles is optimized, the support time is further shortened and the average utilization rate of vehicles is improved. Finally, the optimized apron support vehicle number configuration and the best scheduling scheme are given.

Power Transformer Voiceprint Operation State Monitoring Considering Sample Unbalance

The voiceprint characteristics of transformers are closely related to the operating conditions, but there is currently a lack of effective research on the voiceprint characteristics of transformers during operation. First of all, this article collects three operating conditions of load, light load, and no load on the basis of the transformer voiceprint signal acquisition platform. Secondly, in view of the characteristics of the transformer’s voiceprint, the 50Hz frequency multiplier component amplitude is extracted to form a feature vector, which solves the problem of low utilization rate of common feature extraction information. Finally, in view of the problem of transformer voiceprint failure and sample imbalance caused by fewer abnormal samples, a pattern recognition based on the RUSBoost algorithm is proposed. The algorithm has good recognition accuracy and applicability for transformer voiceprint samples with imbalance problems. The research results provide effective support for the monitoring and identification of the mechanical condition of transformers with sample unbalanced voiceprints, and the analysis of the operating conditions can effectively eliminate the errors that may be caused by their own different operating conditions.

Optimization and feedback control system of dilution rate for 1,3-propanediol in two-stage fermentation: A theoretical study.

In utilizing glycerol to produce 1,3-propanediol by microbial fermentation, the problems of low utilization rate and poor production performance need to be addressed. Based on the analysis of a mathematical model for 1,3-propanediol production from glycerol by Klebsiella pneumoniae, this study theoretically investigated the effects of the dilution rate and the initial glycerol concentration in a two-stage fermentation process and the feasibility of applying the feedback control methods. First, the optimal operation conditions of initial glycerol concentration and dilution rate were obtained. Through the use of feedback control theory, a control strategy for dilution rate was designed and optimized to shorten the settling time (time required for fermentation to reach stability) from 60.92 to 36.68 h for the first reactor, and from 53.66 to 22.68 h for the second reactor. In addition, the yield of 1,3-propanediol in both two reactors reached up to 0.5g·g-1 . The simulation results indicated that the feedback control strategy for dilution rate increased the product concentration, reduced the residual glycerol in the fermentation broth, and greatly improved the performance of the fermentation. A feeding strategy of automatic control for dilution rate has been established and will be applied as an effective guiding scheme in automatic continuous fermentations for production of 1,3-propanediol.

A Knowledge Graph System for the Maintenance of Coal Mine Equipment

With the rapid development of coal mine intelligent technology, the complexity of coal mine equipment has been continuously improved and the equipment maintenance resources have been continuously enriched. The traditional coal mine equipment maintenance knowledge management technology can no longer meet the current needs of equipment maintenance knowledge management, and the problems of low utilization rate, poor interoperability, and serious loss of knowledge have gradually emerged. It is urgent to study new knowledge system construction and knowledge management application technology for large-scale coal mine equipment maintenance resources. Knowledge graph is a technical method to describe the relationship between things in the objective world by using a graph model. It can effectively solve the problem of knowledge dynamic mining and management under large-scale data. Therefore, this paper focuses on the establishment of a coal mine equipment maintenance knowledge graph system by using knowledge graph technology. The main research contents are as follows: Firstly, based on the current situation that there is no unified basic knowledge system in the field of coal mine equipment maintenance, this paper establishes the coal mine equipment maintenance ontology (CMEMO) to effectively solve the problem that there are no unified representation, integration, and sharing of coal mine equipment maintenance knowledge in this field and provide support for the construction of coal mine equipment maintenance knowledge graph. Then, aiming at the problem that the traditional named-entity recognition method has a poor recognition effect and relies too much on artificial feature design, this paper proposes a named-entity recognition model for coal mine equipment maintenance based on neural network (BERT-BiLSTM-CRF) and applies the model to the coal mine equipment maintenance data set for verification. The experimental results show that, under the same data set, the entity recognition effect of this model is more leading than that of other models. Finally, through demand analysis and architecture design, combined with the constructed ontology model of coal mine equipment maintenance field, the entity identification of coal mine equipment maintenance is completed based on the BERT-BiLSTM-CRF model and the Django application framework is used to build the coal mine equipment maintenance knowledge graph system to realize the functions of each module of the knowledge graph system.

Microstructure and properties of laser cladding turning machining scrap

Focusing on the problems of low utilization rate and high cost of laser cladding material, recycled turning machining scrap were used as cladding material to prepare 30CrMnSi laser cladding layer on the surface of 30CrMnSi substrate. The microstructure, hardness, corrosion resistance and wear resistance of 30CrMnSi cladding layer and 30CrMnSi substrate were investigated. Results show that the microstructure of 30CrMnSi cladding layer and 30CrMnSi substrate is mainly dendritic structure and martensite structure respectively, meanwhile, the substrate material presents more pores. The hardness of the laser cladding layer is higher than that of the substrate material due to the fast heating and fast cooling characteristics, and the corrosion resistance of the laser cladding layer is higher than that of the substrate material due to the higher hardness and lower porosity. Therefore, the method adopted in this paper perfectly meets the requirements of green manufacturing and saving resources.

Clothianidin loaded TA/Fe (III) controlled-release granules: improve pesticide bioavailability and alleviate oxidative stress

Neonicotinoid insecticides have been widely used due to their excellent systemic activity and high insecticidal activity, but the problems of low utilization rate and environmental risk have attracted widespread attention. Controlled-release technology is an approach to realize the efficient utilization of pesticides and reduce environmental pressure. In this study, clothianidin (CLO) controlled-release granules (CLO@GR- TA (tannic acid)/Fe (III)) were prepared with TA/Fe (III) coordination chelate as the coating material. These granules exhibited the core-shell structure with 500–1200 µm of particle size, and had obvious release performance and hydrolysis behavior of coating materials. Pot experiments by root application showed that the CLO@GR-TA/Fe (III) showed balanced and lasting control efficacy to broad bean aphids. The plants have a stronger capacity for absorption and enrichment and a higher utilization rate of CLO for CLO@GR-TA/Fe (III), than those for 10% suspension concentrate (SC). One of the hydrolysates of coating materials, TA, a polyphenolic antioxidant, could improve the bioaccumulation amount and alleviating the oxidative stress response of CLO in plants. Our study illustrates that the controlled-release granules base on TA have efficient controlled-release properties and free radical scavenging performance that may eventually be used as pesticide carriers and antioxidants in the field of plant protection.

Design and experimental research of test platform for characterizing a thermoelectric generator based on STM32

In order to solve the problem of low utilization rate of industrial low-grade thermal energy and actively implement the national policy of energy conservation and emission reduction, a low-temperature differential Thermoelectric generator device is designed and implemented based on the thermoelectric effect. According to the basic heat flow method of thermodynamics, the vertical installation sequence of the instrument is determined, and the simulated heat source is carried out in the laboratory. DJR-G type silicon rubber heater is used as the heating device, the fin radiator is used as the radiator and combined with the insulation layer to build the Thermoelectric generator test platform. STM32 microcontroller is the main control core of the instrument; tec1-12708t200 thermoelectric module is the power generation carrier; the main output characteristic parameters of the instrument are displayed on LCD in real time, and the change curve of the output parameters is monitored on the upper computer in real time. The experimental data show that when the load resistance is 2.5 Ω, it matches the equivalent resistance, and its output power reaches the maximum value; when the cold end of the Thermoelectric generator device is effectively cooled, its output power will increase by 0.1W. The conclusion shows that the instrument can effectively realize the Thermoelectric generator function and improve the utilization rate of low-grade thermal energy.

Study on comprehensive utilization technology of low concentration coal bed methane

Aiming at the problems of low utilization rate and serious environmental pollution caused by low concentration coal bed methane emission in a coal mine, the utilization technology of low concentration coal bed methane was studied by means of field investigation and theoretical calculation, and the technical solution of comprehensive utilization of low concentration coal bed methane combining regenerative oxidation and cryogenic liquefaction was obtained, which realized the “coal and gas are co-mined and shared” and constructed the virtuous cycle development of “use to promote pumping, pumping to promote safety”. The research shows that: the low concentration coal bed methane with concentration of about 5% is converted into high temperature flue gas by regenerative oxidation, and the heat energy is extracted to realize the heating in the mining area; the coal bed methane with concentration of more than 35% is purified and liquefied into LNG product by cryogenic liquefaction, so as to realize long-distance transportation. The technology improves the utilization rate of coal bed methane in the mining area and eliminates the burning of coal for heating. The annual utilization of pure gas is 53.38 million m3, generating economic benefits of 211 million yuan and reducing CO2 equivalent by 767,000 t. The safety, economic and environmental benefits are remarkable. This technology has practical significance to improve the utilization rate of gas and promote the realization of the goal of zero gas emission.

Antibacterial Performance of a Gold-Loaded g-C3 N4 Nanocomposite System in Visible Light-Dark Dual Mode.

Semiconductor photocatalysis technology, which can kill pathogenic microorganisms in a green and broad-spectrum way, is a new research field with great application potential. Due to the dependence on light, semiconductor materials have the problems of low utilization rate of sunlight and inactivation under dark conditions. A simple Au-loaded g-C3 N4 (Au/g-C3 N4 ) nanocomposites was studied. Under dark conditions, the antibacterial efficiency of 1.2 % Au/g-C3 N4 reached 99.1 % relative to 105 CFU (Colony-FormingUnits)/mL E. coli. Under light conditions, the antibacterial efficiency of 0.9 % Au/g-C3 N4 reached 94.1 % relative to 107 CFU/mL E. coli. The influence of contact time, Au loading and bacterial concentration on its antibacterial performance under dark conditions was discussed in detail. Through photoelectrochemistry, SEM, TEM and reactive oxygen species (ROS) detection the microscopic charge behaviour was revealed in the system, and a light-dark dual-mode antibacterial mechanism was proposed.

Experimental study and reflection on peacetime and wartime reconstruction of large general hospitals in public health emergencies.

To propose the architectural layout for the big general hospital in the face of public health emergencies, we analyzed the conditions, methods, problems and countermeasures for the reconstruction of the isolation ward from the existing medical building layout of a general hospital. The affected areas met the requirements of isolation ward in the reconstruction, and realized the corresponding partition and separation of people. But the cost of occupying the medical room should be concerned. General hospital should be alerted to potential risks of public health emergencies. The characteristics of different construction types, defects, and the function of the hospital should be considered in the construction, rebuilding, and expansion of the hospital, which shouldnot only meet the needs of the development of the hospital daily usage but also consider dealing with emergent public health events. We can adopt the reasonable layout, including setting up a firewall-like device between the channel and the floor, an ordinary ward at ordinary times, and an independent space for emergency by pulling down the gate. This strategy can not only avoid the problem of low utilization rate of the space occupied by the corresponding area in the ward for diseases spread by air and droplets, maximizing the efficiency of the medical site, but also avoid the problem of emergency response to the temporary reconstruction.

Small and Medium-sized Ship Exhaust Heat Recovery Device Based on Vortex Tube Effect Verification

With the continuous development of China’s economy, the number of Chinese ships has increased year by year. The problem of low utilization rate of waste heat energy of diesel exhaust in existing small and medium-sized ships has become increasingly prominent, and the distillation method in marine desalination has high energy consumption and large equipment volume. Reverse osmosis is a serious pollution. Based on this, we designed a small and medium-sized ship exhaust heat and lightening device based on vortex tube effect. Compared with the traditional lightening technology, the design advantages of this work are reflected in the following three aspects: 1) designing the vortex tube cold and heat separation effect, achieving the step utilization of the exhaust air, reducing the power consumption; 2) the device is small in size and can save The internal space of the ship; 3) The desalination process is simple, there is no influent pretreatment process, and the environmental pollution of the chemical agent is reduced; 4) The device can provide a negative pressure environment for the exhaust port of the diesel engine, reduce the exhaust back pressure of the diesel engine, and improve the working efficiency of the diesel engine.

Application of Reverse Car-seeking in Large Underground Parking Lot Based on A Star Algorithm: A Real Case

In order to solve the problems of low utilization rate of large parking lots and low efficiency of parking turnover, it is proposed to use A-star algorithm to plan the shortest path for finding a car, and run it in Android system to realize reverse car-searching. By analyzing the current situation of large underground parking lot barriers, A-star algorithm converts the starting point to the destination route into the corresponding parking space to the destination parking space path, calculates the optimal path and provides real-time path car navigation for the vehicle owner. According to the path searched by the A-star algorithm in the Android system, the time spent by the user to blindly search for the vehicle is largely saved, and the parking space utilization rate and the parking turnover rate are effectively improved. Therefore, the research has certain application value in the large parking lots.

Analysis on utilization of Beijing local roads using taxi GPS data

Local roads play an important role in increasing city mobility, and bringing convenience for citizens. In this paper, the utilization of Beijing local roads is analyzed using taxi GPS data for the first time. We evaluate the utilization of Beijing local roads quantitatively from different perspectives, with the aim to answer two questions: 1. Is there a problem of low utilization rate of local roads in Beijing? 2. If yes, which parts of Beijing are worse? To quantify utilization rate of local roads we propose detour ratio R index. With this index, we perform analysis from different perspectives, including comparison between Beijing and New York City, and efforts to figure out areas with low local road utilization rate. The results show that Beijing does have the problem of low utilization rate of local roads, and areas with low local road utilization rate are concentrated in Zhichunlu (▪), Muxidi (▪), Shuangjing (▪), and Liuliqiao (▪) regions. The paper concludes with some policy suggestions regarding how to improve the utilization of local roads. This study offers significant insight that can help understand the urban road construction better, improve traffic condition and human life quality.

Threshold Determination for Sharing Bus Rapid Transit–Exclusive Lanes with Conventional Buses

Sharing bus rapid transit (BRT) exclusive lanes with conventional buses is being considered to solve the problem of low utilization rate of BRT-exclusive lanes. However, the quantitative conditions and threshold that determine when to share need to be study. This paper took the common section of BRT and conventional bus lines as its research object. Practical investigation was conducted to analyze shared characteristics from multiple perspectives and explore influencing factors and mechanisms for sharing implementation. Based on the survey results, analytical models were established to quantify the influencing factors from three perspectives of road section, intersection, and bus stop. We selected departure volume of conventional buses as a threshold index and then summarized the constraints and the calculation process of sharing threshold. Finally, numerical examples of different scenarios were used to verify the feasibility and effectiveness of the method. The operation efficiency of the road section on exclusive lanes was the constraint on the lower limit of the shared threshold, while the upper limit was constrained by queuing probability or bus operation time under different intersections and stop spacing, which can provide reference for the shared setting of exclusive bus lanes.

Numerical Simulation of Marine Internal Wave Dynamics Based on Functional Analysis

Liu, H., 2018. Numerical simulation of marine internal wave dynamics based on functional analysis. In: Liu, Z.L. and Mi, C. (eds.), Advances in Sustainable Port and Ocean Engineering. Journal of Coastal Research, Special Issue No. 83, pp. 12–16. Coconut Creek (Florida), ISSN 0749-0208.For the low utilization rate of marine resources and little understanding of the dynamics of some marine resources, it is necessary to study the dynamic numerical simulation of ocean waves. The current method has a problem of low utilization rate. In this paper, a numerical simulation of marine internal wave power based on functional analysis is presented. The method firstly combines the solving method of N-S equation to establish the theoretical problem of water wave power numerical tank and the interaction between water particles is expressed through the nucleon function. The concept of particle density is introduced to realize the incompressibility of the fluid and the numerical simulation analysis of the wave power in the ocean is carried out by using functional analysis.The experimental results show that this method can be used effectively in marine resources.

Strategies for improving the management efficiency of scientific research instruments and equipments

Objective To explore the strategies of promoting professional guidance, building a shared platform and effective performance evaluation, as well as dealing the problems of low utilization rate and repeated purchase of scientific research instruments and equipment faced by colleges and universities at the present stage, to provide further reference for the management of scientific research projects and equipment in Colleges and universities. Methods Taking A University as an example, identify and analyze the problems existing in the management efficiency of scientific instruments and equipment. proposed possible solutions based on relevant experience at home and abroad. Results Universities represented by A University are facing the main problems of low utilization rate of scientific research instruments and equipment and repeated purchases. Preliminary results have been achieved in solving these problems by promoting professional guidance, building a shared platform and effective performance evaluation. Conclusions The management of scientific research instruments and equipment in Colleges and universities needs to constantly innovate management methods and optimize the allocation of resources, promote the opening and sharing of scientific research instruments and equipment, enhance the efficiency of scientific research instruments and equipment management, and strengthen the management of scientific research funds. Key words: University; Scientific research; Asset management

Research on Power-Balance Control Strategy of CHB Multilevel Inverter Based on TPWM

Against to the problems of low utilization rate of DC-side voltage of Cascaded H-bridge (CHB) multi-level inverter Carrier Disposition (CD) modulation strategy and unbalanced output power of each cascaded H-bridge units, a power balanced based In-Phase Disposition Trapezoidal Pulse Width Modulation (IPD-TPWM) strategy is proposed in this article. By selecting an appropriate trapezoidal wave triangulation rate $\delta $ , the modulation strategy can greatly increase the amplitude of the CHB inverter output voltage fundamental wave while ensuring the waveform quality of output phase voltage, and realize the power-balance of H-bridge units within a full modulation ratio range by changing the arrangement of triangular carriers in the vertical direction while using the carrier segment in the half carrier period of the IPD-TPWM strategy as the basic unit. Therefore, it has solved the problem of low utilization rate of DC-side voltage and unbalanced output power of each unit. At the same time, the Total Harmonic Distortion (THD) of output line voltage of the modulation strategy is lower than that of IPD-SPWM strategy in the whole modulation degree, which effectively improves the quality waveform of the output line voltage, and can be conveniently used in N-level CHB inverters. Moreover, the working stress of all the unit switching tubes is the same, the heat dissipation distribution is uniform, the switching loss is effectively reduced, and the service life and system reliability are improved. Finally, the Matlab/Simulink simulation model and experimental platform are established to verify the validity and practicality of the modulation strategy.