bluuebunny/crossref_metadata_2025_split huggingface dataset:
Response surface methodology for optimization of medium components for extracellular protease production by Enterococcus faecalis InaCC B745
Authors: Rohmatussolihat  , Lisdiyanti P , Sari M N , Sukara E 
Published: May 2021

Abstract

Enterococcus faecalis InaCC B745 was isolated from dadih, a traditional fermented milk from Bukittinggi, West Sumatra. Previous study shows that the lactic acid bacteria was able to produce protease. In this study, protease production was optimized using response surface methodology (RSM) with central composite design (CCD). The total of four variables and five-level combinations namely: 0-4% (w/v) of skim milk, 0-2 % (w/v) of yeast extract, 0-2 % (w/v) of glucose, and 0-2 % (w/v) of CaCO3. Statistical analysis showed that the production of protease by E. faecalis InaCC B745 is significantly influenced by skim milk, yeast extract, glucose, and CaCO3, combination of skim milk and yeast extract. The final concentrations of the optimized medium were 3% (w/v) skim milk, 1.5 % (w/v) yeast extract, 0.89 % (w/v) glucose, and 1.5 % (w/v) CaCO3. Under these conditions, the model predicted of protease activity was 60.637 U/ml or around 57.3% increased.
Improvement of yogurt quality from mushrooms and nuts by the addition of Amyloproteolytic from Lactobacillus satsumensis EN38-32
Authors: Khusniati T , Widiawati A , Yuningtyas S , Sulistiani  
Published: May 2021

Abstract
Yogurt made from the vegetable is good for human health. This study focused on improving the quality of yogurt from mushrooms and nuts with the addition of amyloproteolytic enzymes from L. satsumensis EN38-32. Pasta flour juice from oyster mushroom (Pleurotus ostreatus), button mushroom (Agaricus bisporus), soybean (Glycine soja), and mung bean (Vigna radiata) were used to make yogurt with milk yogurt as a comparison. The α-amylase activity was measured by the DNS method, while the protease activity was measured by formol titration. Reducing sugar was detected by the Bernfeld method, while degraded protein by titration. The AOAC method measured total acid and proximate analysis. The results showed that the increase in reducing sugar and the increase in total acid in oyster yogurt, button yogurt, and soygurt with and without the addition of amyloproteolytic enzyme from L. satsumensis EN38-32 was lower than that in mung bean yogurt with each value of 0.0169% and 0.0770% (p <0.01). Carbohydrate (11.30%) and protein (1.12%) in oyster yogurt were higher than button yogurt, while carbohydrate (13.95%) and protein (3.15%) in soygurt were higher than in mung bean yogurt. Based on its nutritional content, soygurt was the best yogurt compared to the others.
Kinematics motility of friesian-holstein sperm sexing in l-ascorbic acid treatments
Authors: Maulana T , Afiati F , Gunawan M , Kaiin E M 
Published: May 2021

AbstractThe study aimed to examine the kinematics motility and recovery rates of frozen-thawed Friesian Holstein bull sexing semen in the addition of l-ascorbic acid treatment. Semen collected from Friesian Holstein bulls with the minimum standard of sperm motilities for sexing sperm (60%), and abnormality (<20%) used for this study. Semen was diluted with final concentration 300x106 sperm/ml in Brackett-Oliphant (BO) medium. The sperms were sorted using the BSA column method. Sexing sperm were extended with Tris egg yolk (TEY) extender in addition L-Ascorbic Acid (LA) 0%, 0.25%, 0.5%, and 0.75% before freezing process. Frozen sexing semen was thawed for the kinematics motility evaluation with parameter; Tmot, Pmot, VAP, VCL, VSL, LIN, ALH, BCF, DAP, DCL and DAP using CASA system also recovery-rate evaluation. The results showed kinematics motility evaluation for 0.75% TEY-LA had lowest value (P<0.05) in Tmot, Pmot, velocity and distance compared to control group, 0.25% and 0.5% TEY-LA. The recovery rate 0.5% TEY-LA had highest values between among all treatment in X and Y frozen sexing semen. In conclusion, the addition of 0.5% l-ascorbic acid to tris egg yolk extender could be advantageous tool to improve the kinematics motility and increased recovery rates of Friesian Holstein sexing sperm.
Simulation of Fuel Cell Power Generation System Based on AMESim
Authors: Jiang Xue , Tao Yufei , Tang Chuanjun , Zhao Hongwei , Li Weilin 
Published: May 2021

Abstract
Fuel cell has become the main power source of the fuel cell electric vehicle due to its advantages of high ideal energy conversion efficiency, low noise, high reliability and maintainability. The fuel cell power generation system is an integrated system including the fuel cell stack. Its physical model covers many subjects such as electricity, thermodynamics, hydrodynamics and electrochemistry, which makes it difficult to change the simulation of fuel cell power generation system. In order to study the characteristics of fuel cell system, the model of proton exchange membrane fuel cell system is set up using AMESim. The model mainly includes fuel cell stack, gas supply subsystem, cooling subsystem and DC/DC converter. On this basis, the characteristics of fuel cell stack and its subsystems under dynamic conditions are analyzed.
Simulation research on the flow field performance of the supersonic separator for natural gas
Authors: Lv Jin 
Published: May 2021

Abstract
The separation of natural gas dehydration and de-heavy-hydrocarbons is an important part of natural gas treatment, the main purpose of which is to prevent liquid water in the later processing, transportation and storage of natural gas, and to prevent acidic gas dissolving in free water which will cause the corrosion of pipelines and equipment. This paper introduces a new type of natural gas separation technology— supersonic gas-liquid separation technology. Based on the working principle of supersonic gas liquid separator, using relevant theories such as fluid mechanics, gas dynamics and thermodynamics, the structure of Laval nozzle was mainly optimized and the flow field of the separator was simulated through ANSYS software, the distribution of the characteristic parameters such as pressure, velocity, temperature of shrink segment, throat, expansion segment of the supersonic cyclone separator nozzle were studied in this paper. The results show that the design of the nozzle structure meets the needs of low temperature, can make the water vapor in natural gas condense into small droplets and separate out, so as to achieve the goal of natural gas dehydration. Then, comparing the different design methods of Laval nozzle, the most reasonable design scheme is selected to improve the separation efficiency of the separator.
Analysis of injection pressure
Authors: Ding Xiangnan 
Published: May 2021

Abstract
In the daily production of water injection wells, oil pressure is a very important production parameter. According to the existing theory, oil pressure plus liquid column pressure is the injection pressure at the bottom of the well, but this theory is contradictory to some production phenomena. This paper analyzes this problem and concludes that pump pressure is the decisive factor of injection energy, which can better explain the practical problems in water injection production.
Application of Molecular Simulation Technology in Improving Oil Recovery
Authors: Feng Zhen , Xu Jianping , Ren Zongxiao , Ma Rui 
Published: May 2021

Abstract
With the continuous development of oil exploitation, the research on the oil industry has gradually shifted from macro to micro. Molecular simulation technology has attracted wide attention due to its advantages of saving costs, shortening the experimental period, and realizing the limit simulation conditions that are almost impossible under physical experimental conditions. Petroleum workers use molecular model to study the effects of different properties on adsorption and desorption. The results show that the adsorption capacity of CH4 increases with the increase of pore size and pressure, and decreases with the increase of temperature and water content. The interaction between clay minerals and CO2 was discussed, and various reactions formed after CO2 was inserted into clay minerals were discussed. Exploring the adsorption and aggregation behavior of surfactants on the interface and analyzing the influence of various properties of surfactants on oil displacement effect are helpful to optimize surfactants and improve oil displacement efficiency. Scientific research on microscopic seepage of polymer flooding has been carried out, and a large number of studies have been carried out on light hydrocarbon diffusion, polymer viscoelasticity and diffusion properties of small molecules in pores, which makes the evaluation of oil displacement effect more accurate. The application of molecular simulation technology in the above studies has obtained the properties that cannot be extracted from many macro experiments, which provides an effective method for the study of theoretical mechanism and better guides the actual production.
Study on the applicability of sand control fracturing technology in Lamadian oilfield
Authors: Kong Jie 
Published: May 2021

Abstract
At present, the proportion of water drive fractured wells is as high as 85.8%, and the proportion of repeated wells is as high as 47.7%. In view of this reality, the potential tapping objects are gradually transferred to isolated sand body, river channel edge and top of thick oil layer. Due to the limited fracture length ratio of conventional fracturing, the potential tapping effect is poor. Therefore, the sand body fracturing method is adopted for this section, that is, increasing the fracturing scale and improving the production degree of oil layer by increasing the fracture length ratio. According to the statistics of the effect of sand control fracturing well, combined with the sand body development characteristics, connectivity characteristics and injection production relationship, the influencing factors of sand control fracturing effect are analyzed, and the applicability of sand control fracturing technology in Lamadian oilfield is clarified.
Storage and transportation technology solutions selection for large-scale hydrogen energy utilization scenarios under the trend of carbon neutralization
Authors: Pan Weiwei , Wan Tian , Han Yang , Liu Shengzhi , Fu Jiang 
Published: May 2021

Abstract
This paper mainly introduces the main pain point of China’s civil hydrogen energy supply chain - the problem of storage and transportation, and analyzes the safety, economy and scale effect and other issues of the existing hydrogen energy storage and transportation, compares with other storage and transportation technology solutions, and comprehensively screens out the storage and transportation technology solution mainly based on liquid hydrogen technology. The liquid hydrogen technology solution has significant advantages over the existing compressed hydrogen system in terms of safety, economy and scale effect, especially for future large-scale hydrogen energy application scenarios. In addition, the future hydrogen energy storage and transportation system based on liquid hydrogen technology can help improve the overall utilization efficiency of country’s renewable energy, promote the country’s energy transition, promote the electrification of the country’s transportation sector, and help achieve China’s carbon emission reduction 2030/2060 target.
Calculating control area and reserves of single well by triangulation method
Authors: Xing Jishuang 
Published: May 2021

Abstract
The arithmetic average method is a conventional method to calculate the geological reserves. However, it ignores the influence of heterogeneity in the block, especially the faults. The calculated single well controlled reserves are often quite different from the actual status, which can’t guide the development actions accurately. Therefore, it is necessary to introduce a more accurate calculation method. The triangular network method introduced in this article can improve the accuracy when calculating the control area of single well in fault area, support to evaluate the control reserves of single well, and reflect the changes of geological reserves near each well point accurately.
Research on Lightning Protection Verification Based on Three-dimensional Model of Substation
Authors: Hu Junhui , Li Zan , Jing Tian , Hong Min , Hu Mingxun , Xu Wenjie 
Published: May 2021

Abstract
In the past, the lightning protection design of substations was carried out by manual calculation. The joint protection of multiple lightning rods and the joint protection of lightning rods of unequal height brought a huge amount of work to the calculation, which was low in efficiency and prone to errors. At the same time, the lightning protection design based on two-dimensional drawings cannot visually display the real lightning protection situation, and cannot reflect the correctness of the lightning protection results during the blueprint review process. The review experts need to repeat calculations to demonstrate. Computer simulation and calculation of lightning protection in substations can not only greatly improve work efficiency, but also visually verify the feasibility of the design scheme through the visual display of the three-dimensional design model of the substation. This thesis mainly studies the realization method and process of lightning protection design based on 3D software, and gradually realizes 3D visualization of lightning protection area and completes lightning protection verification.
Research on Key Technologies of Intelligent Control Switches in Distribution Networks
Authors: Guo Fusheng , Zhou Weihan , Wang Yongqing , Su Yongzhi , Wu Weiping , Li Weichao 
Published: May 2021

Abstract
With the development and widespread application of high-power power electronics technology, there is an interaction between distribution network voltage and reactive power and power quality. It is prone to operating over-voltage and closing inrush when closing, and reignition often occurs during opening. The voltage is too high, which far exceeds the voltage and insulation performance that the equipment can withstand, resulting in damage to the equipment. In response to the above problems, this article proposes an intelligent control switch closing and opening strategy to reduce the impact on the equipment during the reactive power compensation switching process. Considering the different dispersion of the intelligent control switch, the process of closing the parallel capacitor is simulated, and the effect of the intelligent control switch on the overvoltage and inrush current limitation is compared, which proves that the strategy is effective.
Bidding strategy of wind-solar hybrid generation system in the spot market considering bidding deviation penalty
Authors: You Daning , Liu Hanghang , Si Juncheng , Zhou Lei , Sun Mingyu , Jiang Ting 
Published: May 2021

Abstract
In recent years, as State Grid Shandong Electric Power Company is one of the key pilot construction units of the new strategy of “realizing the coordination and interaction of source network, load and storage”, renewable energy power generation systems have gradually changed from a subsidy object to an independent bidding subject when participating in the spot power market of Shandong Province. The uncertainty of renewable energy output and spot market price leads to the loss caused by bidding deviation when participating in the power market competition, and the income drops significantly. The good complementarity of wind and solar energy can reduce the fluctuation of renewable energy output and promote renewable energy consumption. First, the joint output probability distribution of a wind-solar hybrid generation system is simulated based on Copula function. Then, aimed at maximizing the bidding profit of the wind-solar hybrid generation system in spot market, a two-stage mixed integer stochastic optimization bidding model considering bidding deviation penalty is established. The conditional value at risk theory is used to evaluate the risk of renewable energy and electricity price forecast deviation, and the optimal bidding strategy is obtained.
Effectiveness of bacterial sulfidation flotation for the separation of malachite: Impact of pH, sulfide concentration and sulfidation time
Authors: Wang Xu , Chen Yaozong , Song Zibo , Liu Mengfei , Gan Min , Zhu Jianyu , Chen Daixiong 
Published: May 2021

Abstract
Previous research paid less attention on the mechanism and application of bacterial sulfidation in mineral flotation. In this study, sulfate reducing bacteria strains reduce sulfate to produce sulfides, which are used as sulfidizing reagents for malachite. Then, the system influence factors such as pH, sulfides concentration and sulfidation time are controlled. The results showed that the most suitable conditions of malachite bacterial sulfidation system were pH of 9.0, sulfide concentration of 140mg/L and sulfidation time of 15mins. For further study, SEM and FTIR were used to perform of sulfide film formed on the surface of malachite. The result of sulfide film on the malachite surface is compact, and the malachite flotation properties are greatly improved after bacterial sulfidation.
Research on Forecast of Water Demand in Jinzhou Based on Grey Model
Authors: You Kun , Kang Ning , Fu Jinxiang , Gao Yujia , Qian Weiyi , Wang Juliang 
Published: May 2021

Abstract
According to the related requirements of water demand prediction in Jinzhou, and based on the current situation of water resource carrying capacity in Jinzhou from 2011 to 2017 and the grey model, the water demand from 2021 to 2025 was predicted, and the grey GM(1,1) model of ecological water demand, virtual aquatic yield, residential water consumption and urban public water consumption was established. The results showed that the regional water demand showed a trend of slow increase, among which the urban public water demand had a larger growth space, while the ecological water demand and virtual aquatic production had a smaller growth range. The accuracy of the grey forecast model is more than 90%, It can provide a new way to forecast the main water use and total water demand.
Study On Water Injection Effect of New Reservoir For Petroleum Energy Development
Authors: Wang Chunrui 
Published: May 2021

Abstract
Oilfield has gone through the stages of self injection production, water injection development and three times of chemical agent injection development. At present, it has entered the late development stage of high water cut, and the production and new exploration reserves have decreased significantly. As a potential resource of high water cut later development, SA0 formation reservoir has a certain oil and gas abundance. However, because of its poor physical properties and strong water sensitivity, SA0 formation reservoir in Oilfield has great difficulties in water injection development. This set of reservoir was not developed in the early development of Oilfield. With the improvement of development technology and the increasing demand of recoverable reserves, the development of SA0 formation reservoir becomes more and more important. However, there is no in-depth study on the specific characteristic parameters of the reservoir and the feasibility of water injection development, which restricts the development of this set of reservoir. Therefore, this paper explores the feasibility of waterflooding development of lithologic and physical properties of SA0 formation reservoir in Development Zone. Laboratory experiments and field practice show that SA0 formation reservoir is a low permeability and highly sensitive reservoir. 3% concentration of anti swelling agent can effectively inhibit the expansion and migration of clay minerals, and play the purpose of protecting the reservoir. In the field test, through adding clay stabilizer to perforate and complete the well with flow limiting method, a high liquid production capacity has been achieved. At the initial stage, the average daily oil production of a single well is more than 1.50t. The production performance of oil wells is quite different, the liquid production layers are concentrated, and most of them are dry layers. A certain understanding has been obtained in the waterflooding development of SA0 formation in development zone of Oilfield.
Research on simulation of energy consumption of ground water-source heat pump air conditioning system in plant factory
Authors: Yang Gukun , Shi Huixian , Xu DeTian , Shen Zheng , Zhang Zhonghua , Shen Haowen , Wang Zijing 
Published: May 2021

Abstract
The study of low-cost energy supply methods for large plant factories in China is of great significance to promote the healthy and steady development of large greenhouses. Aiming at the problems of high cost, poor stability, chaotic production management, and no indicator of long-term operation energy consumption in the operation of large plant factories, this paper analyzes long-term operation data by studying the heating situation of Chongming plant factory to improve plant factory regulation methods for the purpose of energy saving and cost reduction. A plant factory model was constructed using TRNSYS to simulate typical annual energy supply throughout the year to obtain cooling and heating energy consumption. The simulation results show that the annual peak heat load of the plant factory is 1502.6 kW and the peak cooling load is 913.8 kW. The annual energy consumption of the whole plant factory is 3799.12 GJ for cooling and 4468.34 GJ for heating, and the annual energy consumption of the whole plant factory is 8267.46 GJ. A8 and its three surrounding greenhouses A6, A7, and A10 can be used as a single zone for energy supply. This zone takes advantage of the structural characteristics of the building to reduce energy consumption. The simulation shows that the ground source heat pump system is sufficient to supply the energy consumption of these four greenhouses and even to achieve the optimal temperature conditions for growing vegetables inside them.
Design of simulation platform for chassis engine driven generating system
Authors: An Shu , Wu Jie , Yin Zhiyong , Ren Xiaokun 
Published: May 2021

Abstract
With the development of equipment on-vehicles, the chassis engine driven generating technique is paid more and more attention in the mobile operation vehicles. Based on the analysis of engine driven power generating working principle, this paper designs a simulation platform for chassis engine driven generating system, mainly including the following four parts, such as engine chassis simulation mechanism, engine driven generator, electric energy transducer and testing and displaying system. With this platform, power generating experiments under different working conditions can be performed such as parking power generation, traveling power generation, section speed regulation power generation and load increase and decrease. The result of the experiment proves that the power output from this simulation platform can meet the demand for electric requirement from the equipment, and has good static and dynamic characteristics, which can provide certain reference value for the design of vehicle chassis engine driven generating system.