bluuebunny/crossref_metadata_2025 huggingface dataset:
Architecture of the decision-making system concerned to the management of repair of the motor-vehicle transport at the large-scale enterprise
Authors: Egorov S Ya , Kalach A V , Salih H S , Zatonsky A V , Felker M N
Published: May 2021

Architecture of the system for support of the decision-making for the transport vehicles enterprise providing the balance between reliability and costs. This allows providing a decision-making person with reliable and qualitative information concerning consequences of the choice between this or that kind of repair. Technical realization of this approach is implemented with the use of 1C-accounting software.
Optimization of the number of pumping stations when tracing distribution lines of the external fire-fighting water supply system
Authors: Kalach A V , Cherepanov E A , Dmitriev E V , Akulov A Yu
Published: May 2021

New graphical algorithms of planning, optimal deployment of the pumps for the external firefighting are proposed and mathematical models of optimization when constructing external various water-supply pipeline networks for fire hydrants in a separate community that does not involve highways or special roads are also presented.
Methods for prediction of the avalanche danger
Authors: Kalach A V , Solovyov A S , Karpov S L , Martinovich N V , Kalyuzhina G S
Published: May 2021

The work considers methods for the prediction of the avalanche danger. It shown that for the local forecasts the most efficient way is to simulate snow mass by the particles dynamics technique. Basin on this model it is possible to predict the critical parameters for the avalanche sliding, the character of motion of snow mass, the force and energy of its impact on the movable and immovable obstacles with different shape and, hence, a destructive avalanche ability.
Support technologies for management of the land flood protection
Authors: Kalach A V , Arifullin E Z , Nicheporchuk V V , Kalach E V , Oblienko A V
Published: May 2021

The problems of management for the safety of territories are considered as well as their application with the landfloods as an example. Model of organization of the informational resources is proposed. Models of decision-making in the conditions of uncertainty are described as well as the architecture of information-analytical systems allowing integration of the new technologies for digitization of economics.
Analysis of the compensation equation for rational aggregation functions
Authors: Ledeneva T M , Umuvakin V M
Published: May 2021

The compensation equation is the law of conservation of a certain quantity with respect to a given class of admissible transformations. This paper discusses approaches to the construction of a compensating function for rational aggregation functions, including those with the associativity property.
Analytical model for calculating the effectiveness of the modified access control subsystem of the information security system against unauthorized access in automated systems
Authors: Batskih A V , Bulgakov O M , Drovnikova I G , Krisilov A V
Published: May 2021

The paper considers an analytical model for calculating the performance indicator of the access control subsystem of the information protection system against unauthorized access in an automated system, the use of which allows to significantly simplify the calculation and increase its accuracy. The dynamics of subsystem functioning is described using a stochastic Petri net using the Laplace transform. Using the example of the standard information protection system against unauthorized access “Strazh NT 4.0”, the results of calculations of probabilistic and temporal characteristics of the model “Starting the PC and identifying the user” are presented, which describes the functioning of the access control subsystem when it is modified by implementing additional authentication based on the regular user keyboard handwriting recognition. Obtaining analytical dependencies of transition probabilities between the states of a modified subsystem allows optimizing its operation and verifying compliance with the requirements for the probability of performing functional tasks in a given time, while increasing the overall level of security of the automated system.
About building a basis surface in inverse kinetic problems for non-break processes of diene polymerization
Authors: Gizzatova E R , Ismagilova A S , Podvalny S L
Published: May 2021

The work contains a mathematical description of diene polymerization with a neodym-based Ziegler-Natta catalysts. The resulting system of differential equations was reduced from infinite to finite by the method of moments. For this, the basis of nonlinear parametric functions was searched with a method allowing obtain expressions that reflect the kinetics of the polymerization process. The obtained basis of two functions enables us to construct a surface containing local regions of the minimum of the objective function which define the starting points for search of optimum kinetic constant values.
Image texture model based on energy features
Authors: Lyasheva M M , Lyasheva S A , Shleymovich M P
Published: May 2021

In information processing and control systems based on computer vision technologies, it is necessary to provide an effective indicative representation of images for their subsequent analysis. One of the widely used approaches is based on the construction of texture models. In this paper, the description of the texture using energy features is considered. The proposed model is a set of weights of image pixels reflecting their significance from the point of view of image perception. The significance of the pixel is estimated using the energy of the coefficients of the orthogonal discrete multiresolution wavelet transform. The paper presents expressions for calculating pixel weights and shows that the resulting texture models can be used to classify images.
Development of a cloud SaaS service for a comprehensive research of polymerization processes
Authors: Miftakhov E , Mustafina S , Mikhailova T , Podvalny S
Published: May 2021

The article is devoted to the description of the network architecture of the developed cloud SaaS service for the implementation of a comprehensive study of polymerization processes. The main problem of using local software systems for such tasks is briefly voiced. The main methods and mathematical approaches that allow solving the direct problem of predicting the main molecular characteristics of the produced polymer product for various loading modes of the reaction system and the inverse problem of identifying some of the unknown kinetic parameters are considered. Methods and approaches to the development of algorithms and software are considered separately. As part of the cloud service being developed, a three-tier architecture for accessing data and computing resources is described in detail, the main tasks of each level and the advantages of using this approach are described. The hardware and system requirements for the computing nodes of the developed network application have been written out.
Suspended particle transport process modeling based on 2D and 3D models
Authors: Chistyakov A E , Protsenko E A , Kuznetsova I Y , Nikitina A V
Published: May 2021

In this paper, suspended particles transport mathematical model is proposed and investigated. The considered model includes the following factors: the aquatic environment movement; variable density depending on the suspension concentration; multicomponent suspension; change in the bottom geometry as suspension sedimentation result. The 3D diffusion-convection equation approximation based on splitting schemes into 2D and one-dimensional problems. In the paper, convective and diffusive transfer operators’ discrete analogs in the case of partial fullness of the cells are used. Based on the fullness function, the calculated area geometry is described. The difference scheme, which is linear combination of the Upwind and Standard Leapfrog difference schemes with weight coefficients obtained from the condition of minimizing the approximation error, is used. This scheme is designed to solve the impurity transfer problem at large grid Peclet numbers. Based on the results of numerical experiments, conclusions are drawn about the advantages of the 3D model of suspended particle transport over the 2D model. The results of numerical experiments on modeling the multicomponent suspension deposition are presented.
Effect of edible coating application by spraying method on the quality of red chili during storage
Authors: Wibowo C , Haryanti P , Wicaksono R
Published: May 2021

After being harvested, fruits continue their physiological activity, such as transpiration and respiration, which leads to deterioration. The main problem on maintaining the quality of fresh fruit and vegetables is regarding the shelf life. They have short shelf life due to the metabolism still occurs. Therefore, additional treatments are required to prolong the shelf life. Application of edible coating is one of a promising treatments. The coating is known for its ability to prevent moisture loss and create a barrier for gas exchange to give protection from fruits decay by applying it directly to the fruit surface. This experimental study used Completely Randomized Design with two factors. The first factor is the type of starch used for coatings consisting Canna edulis starch, potato starch and sweet potato starch, and the second factor is the variation of nozzle diameter consisting 0.6 mm, 1.0 mm and 1.5 mm. The parameters observed in this study comprised of color parameter (L-, a-, and b-value), ascorbic acid and moisture content, and firmness. The result obtained from this study were analyzed using the F test and continued with the Duncan Multiple Range Test. The result showed that the main material for producing edible coating gave a contribution on the alteration of red chili during storage. Moreover, the differences of diameter of nozzle sprayer also influence the adhering of the edible coating on the surface of the agricultural product. Based on the present research, the selected treatment combination application of an edible coating for red chilies was using of edible film made from sweet potato starch that sprayed with a with a diameter of 0.6 mm nozzle sprayer.
Volatile compounds profile of some Indonesian shallot varieties
Authors: Indrasari Siti D , Arofah Desi , Kristamtini  , Sudarmaji  , Handoko Dody D
Published: May 2021

Shallot, Allium ascolanicum L., is one of the leading horticultural commodities that are widely cultivated in Indonesia. Shallot is a commonly used seasoning for various types of dishes. This study aimed to determine the volatile compounds profile of some raw Indonesian shallot varieties. Four shallots varieties (Bima Brebes, Biru Lancor, Saptosari, and Filipin) were analyzed the volatile component profiles using Solid-Phase Microextraction (SPME)-Gas Chromatography-Mass Spectroscopy (GCMS). The GCMS analysis detected 104 types of volatile compounds in which the major volatile compounds were disulfides, sulfur-containing, thiophenes, and diverse functional groups. The most abundant volatile compound groups in the Bima Brebes variety were sulfur-containing compounds (40.61%), followed by diverse functional groups (28.43%) and disulfide (17.51%). In the Biru Lancor variety, the major volatile compounds were disulfide (44.68%), followed by sulfur-containing (30.90%) and thiophenes (8.80%). The most abundant volatile groups in the Saptosari variety were sulfur-containing (57.06%), followed by disulfide (22.68%) and thiophenes (9.19%). In the Filipin variety, the major volatile compound groups were disulfide (53.80%), followed by thiophenes (15.70%), and sulfur-containing (10.55%). The most abundant volatile compounds in all shallots volatiles were dipropyl disulfide, 1-methylethyl propyl disulfide, (E)-1-(prop-1-en-1-yl)-2-propyldisulfane, and propyl mercaptan.
The implementation of rice’s Good Agricultural Practices (GAP) in Panarukan-Situbondo
Authors: Yekti G. I. A. , Suryaningsih Y.
Published: May 2021

The level of dependence of farmers on chemical fertilizers and pesticides on rice plants can lead to soil nutrient degradation and pest resistance. Also, excessive use of chemicals in rice can leave a residue in the production of rice, thus affecting the food security of rice as a staple food of Indonesian society. Related to this, the government has begun to promote programs related to food safety, one of which is good cultivation techniques or often known as Good Agriculture Practices (GAP). The purpose of this study was to analyze the implementation of GAP for rice in Panarukan-Situbondo. Determination of respondents using a simple random sampling method as many as 60 respondents from two villages, Peleyan and Sumberkolak. While the analysis uses descriptive analysis with a questionnaire assisted. The results showed that the level of implementation of rice’s GAP was at a medium level (66.65%). The highest GAP aspects are in the aspect of nursery and planting, and the two lowest aspects are conservation and soil cultivation, as well as integrated pest and disease protection aspects.
Triple helix as an empowerment strategy for labor fishermen: a proposed model through action research study
Authors: Budiarti Laeli , Setyorini Christina Tri , Susilowati Dewi , Warsidi  , Sukardi Purnama , Jannah Miftahul
Published: May 2021

Labor Fishermen poverty has been an issue for a long time. Several factors cause fishermen poverty, environmental conditions of resources, culture, and structural. The purpose of this paper is to propose a community empowerment model, especially labor that the government can carry out in collaboration with universities and industry. The model formulated in this paper is compiled by conducting a study of the fishermen’s life in the village of Menganti Cilacap. In-depth interviews with fishermen and the village government are done to collect the data. An analysis was conducted to identify fishermen’s needs through government cooperation with universities and industries related to fishermen. The Triple Helix strategy, in this case, is carried out by researchers from Jenderal Soedirman University (university), the Menganti regional government, and the Department of Industry, Trade and Cooperatives (government), and the Mina Sidat Bersatu Cooperative (Industry). Implementing the triple helix strategy is expected to produce real breakthroughs that can be applied directly to improve labor fishermen’s welfare.
The factors contributing to the sustainability of agribusiness MSMEs in Sukoharjo Regency during the Covid-19 pandemic
Authors: Khomah I , Setyowati N , Harisudin M , Adi R K , Qonita A
Published: May 2021

MSMEs play a significant role as one of the elements that encourage the national economy and the Indonesian government highly supports the development of competitive and innovative MSMEs. Making innovation is one of the MSMEs’ efforts to survive during the Covid-19 pandemic because innovation and technology development can generate a creative industry. Technology development can support business activities but MSME players are also challenged with the Covid-19 pandemic today. However, the challenge can turn into an opportunity if they can take the advantage of using technology for online marketing. Competitive MSME players can improve their performance, which can keep their existence and contribute to their business sustainability. This research aims to investigate the factors influencing the sustainability of agribusiness MSMEs in Sukoharjo Regency during the Covid-19 pandemic. This research applied SEM analytical method with SmartPLS 3.0 software. The respondents taking part in this study were 120 agribusiness MSMEs operating in Sukoharjo Regency. The results of the research signify that the factors affecting the sustainability of agribusiness MSMEs in Sukoharjo Regency include the external environment, MSME players’ perception, and infrastructure/technology utilization.
Antioxidant activity of kecombrang preserving powder using foam mat drying method
Authors: Naufalin R , Erminawati  , Wicaksono R , Febryani A T , Latifasari N
Published: May 2021

Food production is one of the easily damaged products, both in processing and during product storage. Therefore, to prevent damage made preservative powders from natural ingredients. One of them is obtained from the flowers of the kecombrang (Etlingera elatior). Kecombrang plant flowers contain bioactive components, namely, alkaloids, polyphenols, flavonoids, and essential oils. This study used a reasonably practical drying, namely foam-mat drying technique. This study aims to determine the best formulation in making kecombrang flower preservative powder using the foam mat drying method. This study used a randomized block design (RBD). The factors studied included maltodextrin concentration and drying temperature. The concentration of maltodextrin consists of three levels, namely 5%, 10%, and 15%, and the temperature consists of three levels, namely 50°C, 60°C, and 70°C. The variables observed were qualitative and quantitative analyses. The best treatment results qualitatively and quantitatively, namely at the drying temperature treatment of 50°C and 5% maltodextrin concentration with a water content value of 5.92%, antioxidant activity value 61.77%, total phenol levels 2.12 mg TAE / g, total flavonoid levels 0.13 mg TAE/g. The qualitative test shows that kecombrang flower preservative powder contains phenolic compounds, flavonoids, steroids, tannins, saponins, and alkaloids.
A comparison of the effectiveness banana stem sap and virgin coconut oil on diabetic wound healing
Authors: Sari Yunita , Isworo Atyanti , Upoyo Arif Setyo , Sumeru Annas , Kurniawan Dhadhang Wahyu , Sutrisna Eman
Published: May 2021

Banana stem sap (BSS) and virgin coconut oil (VCO) is usually used for wound care treatment. However, to date, no study has been conducted to compare the effectiveness of these two therapies. Therefore, this study aimed to compare the effectiveness of BSS and VCO on diabetic wound healing in rats. Male Wistar rats were randomly divided into 3 groups depending on the formulation used on the wound: BSS, VCO, and control-treated with film dressing. The tissue samples were obtained on days 4, and 14. The wound size, the presence of necrotic tissue, level of inflammation, level of fibroblast, and re-epithelialization were assessed. On day 10, wounds in the BSS group were the smallest compared with other groups. The necrotic tissue and level of inflammation in the BSS group were also less as compared with other groups. The re-epithelialization in BSS group was also the most advance compared with other groups. Our study showed that the ability of BSS in accelerating wound healing is better than VCO and film dressing. We recommend nurses and clinician in Indonesia to use BSS to treat diabetic ulcer.
Diversity of Introduced Species of Fishes in Penjalin Reservoir Central Java Indonesia
Authors: Setyaningrum N , Sugiharto  , Susatyo P
Published: May 2021

The decreased diversity of fish is partly due to the introduction of fish or foreign species into the waters. The impact of this entry is relatively vast, not only damaging the environment and genetic but also disturbing the indigenous species and spreading disease and parasites to the fish. This study aimed to analyze the fish diversity of introduced species and indigenous species captured in Penjalin Reservoir and the correlation between biodiversity and water quality. The method included a survey with five Stations of sampling. The present study caught 539 fish, consisted of seven families, ten breeds, and 11 species (six introduced and five indigenous). The diversity of introduced species was higher than that of the indigenous. The captured introduced fish were Oreochromis niloticus, Oreochromis sp, Oxyeletris marmorata, Clarias gariepinus, Cyprinus carpio, and Poecilia reticulata. The similarity index of fish diversity was almost equal across Stations. The O. marmorata species had the highest relative abundance and dominated Penjalin Reservoir. The diversity of introduced species was positively correlated with the parameters of depth, pH, and free CO2 in the center of the reservoir, while the Total Suspended Solid (TSS) of the indigenous species was in the inlet of the Garung river. The significance of the present research is to promote the conservation of fish resources and to maintain a balanced ecosystem, especially the existence of introduced species and indigenous species in the waters of Penjalin Reservoir.
Composition and diversity of macroalgae community in the coast of Karang Bolong, Nusakambangan Island
Authors: Widyartini Dwi Sunu , Hernayanti  , Edy Prabowo Romanus
Published: May 2021

Karang Bolong Beach is a beach located at the eastern tip of the island of Nusakambangan Cilacap. Karang Bolong Beach has a substrate type in the coral and composite substrate (fragment coral, rock, and sand). Therefore, a lot of seaweed grows there. This research aims to determine the macroalgae community on different substrates at Karang Bolong Beach, Cilacap. This is done to explore and use seaweed as a source of bioethanol. The research method used was a survey method - sampling using transects with a random process. The research variables included the macroalgae community in terms of species diversity and abundance on different substrates. The main parameters observed were the number of species and the number of individuals for each species. Supporting parameters consist of current velocity, nitrate content, turbidity, depth, tides, salinity, temperature, and pH. The data obtained were analyzed using Primer-7 to determine the diversity and density of each macroalgae species. The results showed 11 species of macroalgae consisting of Amnasia glomerata, Caulerpa mexiana, Chaetomorpha crasa, Dictyota ciliolata, Eucheuma serna, Gracilaria arcuata. Gracilaria gigas, Laurencia subopposita, Padina australis, Rhodymenia sp., and Ulva rigida. On the coral substrate, there were eight species, and on the composite substrate, six species. Four of these species are found in both substrate types. The diversity of species on the coral substrate varies from low to moderate. The highest abundance on composite substrates dominated by Padina australis biomass with a weight of 431 g.m−2. On coral substrate dominated by Gracilaria gigas with a value of 275.33 g.m−2. The community is in an unstable condition due to ecological pressures.
Screening of microfungi from spent mushroom for decolorizing and removing heavy metals from batik effluent and its toxicity
Authors: Dewi Ratna Stia , Hana
Published: May 2021

The concentrated colors and heavy metals contained in batik waste. Therefore, decolorization and removal of heavy metals is required. The purpose of this study was to screening microfungi for decolorizing and removing heavy metals from batik effluent, and obtaining information about the toxicity of the treatment results. Obtained 3 genera isolated from spent mushrooms, namely Penicillium sp., Aspergillus sp., Trichoderma sp. The superior microfungi for decolorizing and removing heavy metals from batik effluent is Penicillium sp., and its isolate can reduce the toxicity after the treatment results.
Investigation of total organic matter [TOM] content during high and low water in inter-tidal zone sediment at Teluk Penyu Coast, Cilacap, Indonesia
Authors: Haryono F E D , Illahi Z Y , Dewi R
Published: May 2021

Sediment is composed of organic and inorganic particles. Accumulation of organic particles in the sediments is known as organic matter. The present of sediment in the tidal zone and the existence of organic matter accumulation in sediment is influenced by oceanographic pattern. Tide is an important influence as transporting the sediments in the coastal waters, the tides can generate currents that move a mass of water and carry suspended solid material, and become as one of the factors that play a role of organic matter transfer, both to sediment transport and sediment deposition. The purpose of this study is to determine the content and differences of Total Organic Matter [TOM] in sediments during high and low water in a tidal area at Teluk Penyu Cilacap, Indonesia. The LOI (Loss On Ignition) method is carried out to analyze the content of [TOM] in the sediment. The average content of [TOM] in 100 g of sediment during high water was obtained 3.72% and 5.86% when low water. Statistically, tidal patterns at the time of the study were not cause to the difference of the TOM content [p<0.05]. Existence of organic matter in tidal zone sediment plays and important role as a food source for bacterial decomposing organism.
Energy Efficiency Calculation and Air Handling Unit Design Based on Cooling Load Capacity at MASTEK Mosque
Authors: Harsito Catur , Satiya Permana Ariyo Nurachman , Sihta Finda
Published: May 2021

The rate of development growth in Indonesia has resulted in an increase of energy demand. In addition, most power generation systems still use fossil fuels of nearly 50%, in other words this fuel can run out within the next 18 years. The electricity needs in the building come from the use of lighting, computers, office equipment, heating, ventilation, air conditioning and also air conditioning systems (AHU). This paper aims to investigate energy efficiency based on cooling load capacity to reduce energy use and design an air conditioning system. A well-designed HVAC system will have a great impact on indoor air conditions. Room comfortability will be realized throughout the year and also the outside environment if cared for properly according to the procedures of the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) Handbook of Fundamentals. Mastek Mosque required 167,151,241 Btu/h. The ducting design for central air conditioning systems uses 12 x 8 pipes for the main ducting and 10 x 6 for the ducting suction with 12 nozzles and 10 x 6 and 10 x 8 return ducting sizes. This system has the advantages of efficient, silent cooling and increased comfort for prayer.
Forecasting the amount of rainfall in West Kalimantan using Generalized Space-time Autoregressive model
Authors: Utami R , Nurhayati N , Maryani S
Published: May 2021

The generalized space-time autoregressive or GSTAR is a space-time model which can be used to analyze time-series data in several locations considered to be correlated. In this research, the GSTAR model is applied to forecast the amount of rainfall in West Kalimantan, especially at Sintang Station, Melawi Station, and Ketapang Station. The data used for modeling is data of the amount of rainfall for the period January 2013-December 2017, while the data used for model validation is data for the period January 2018-December 2018. The spatial weights used are uniform weights, inverse distance weights, and normalized cross-correlation weights, and the estimation method used is the ordinary least square or OLS estimation. The best model is selected based on the smallest RMSE (root mean square error). The results showed that all spatial weights gave the same good GSTAR(1:1) model because they had almost the same RMSE value. Thus, this model can be used to forecast the amount of rainfall for the period January 2019-December 2019. The forecast results show that for Sintang Station and Melawi Station, the highest amount of rainfall is estimated to occur in March 2019 and the lowest will occur in August 2019. Meanwhile, for Ketapang Station, the highest amount of rainfall is estimated to occur in January 2019 and the lowest will occur in September 2019.
Implementation of autoregressive integrated moving average model to predict total electron content from GPS satellite receiver in Bandung
Authors: Yuniati Marifatul Nur , Sugandha Agus
Published: May 2021

Total electron content (TEC) or free-electron content that is in the ionosphere layer can disrupt telecommunication and navigation systems. This study discusses forecasting the daily average value of total electron content (TEC) during March 2019. The method used in this forecast is the autoregressive integrated moving average (ARIMA) model with the Box-Jenkins approach. The research results show that the best ARIMA model is ARIMA (1,1,1)with an MSE 2.453. The results showed that the daily average predicted TEC value increased every day and the maximum TEC value occurred in the 86th period (86thday) which was 18.4991 TECU (1 TECU =1016electrons / m2).
Increased reliability over current relay (ocr) as a transformer protection with non-cascade coordination patterns
Authors: Prasetijo Hari , Fadli Ari , Priswanto  , Herry Purnomo Widhiatmoko
Published: May 2021

Protection using Over Current Relays (OCR) with cascade coordination patterns is commonly used in 20 kV primary distribution networks to protect transformers from phase to phase fault currents. To anticipate a large fault current, the OCR feeder is equipped with an instant time setting. The problem occurs when the OCR feeder or PMT feeder fails to work then the transformer will be at risk because it is burdened with the fault current for a relatively long time. This study will discuss the use of a non-cascade pattern for the coordination of OCR feeders and incoming OCR in a primary distribution system supplied by a 60 MVA transformer, 150/20 kV from the substation by the calculation method. OCR feeders use very inverse (VI) characteristics and OCR inverses use standard inverse (SI) characteristics. A large feeder fault current is obtained by determining the 3 phase fault current upstream of the feeder as 7 x the nominal current (In) of the transformer. The result is that when the PMT feeder fails to work, the incoming OCR cascade coordination pattern will work with a time of 1.05 seconds. Meanwhile, if we use a non-cascade pattern the incoming OCR will work in the time setting of 0.3 seconds. Work time difference of (1.05 - 0.3 = 0.75 s) shows an increase in protection reliability and reduces the risk of damage to the transformer.
Study on measures of preventing and reducing silting of old hydropower stations in high sediment content reservoir area
Authors: Zhou Heng , Zhang Xinguo , Liu Jing , Lu Xi , Sun Haitao , Di Shengjie
Published: May 2021

For water conservancy projects that have been built on rivers with high sediment concentration, the sediment deposition is the primary problem affecting safe operation. Based on a large hydropower station already built on the Yellow River, combined with model test, simulation analysis and other methods, this paper proposes that the effective method to solve the sediment problem is to use the newly built desilting tunnel to arrange the water diversion power generation system, and give the measures to solve the siltation of power generation hole and surge chamber involved in this method. The engineering practice shows that the siltation prevention and reduction measures mentioned in this paper can effectively solve the siltation problem of the old hydropower station in the high sediment content reservoir area.
Research on Diagnosis and Treatment of Abnormal Temperature Fault of Hydro-generator in Hydropower Station
Authors: Yu Yang
Published: May 2021

Electric power as the main energy source in the world today, hydropower is an important part of electric energy in China. As the core equipment of hydroelectric power generation, hydro-generator will inevitably cause fault during operation, and abnormal temperature is one of the main faults. When failure occurs, timely and accurately find out the reasons and take effective solutions can minimize the damage caused by the failure. This article expatiates on the malfunctions and causes of common abnormal temperature of hydro-generator, and proposes measures to distinguish and solve the faults, so as to effectively solve the abnormal temperature problems of hydro-generator and ensure the safe and stable operation.
Uncertainty Evaluation of Wind Speed Sensor in Automatic Weather Station
Authors: Yang Zhen , Zhang Husheng , Wang Qiang , Li Cuicui , Xu Wenlong , Chen Shengyuan
Published: May 2021

Uncertainty is a description of the degree of uncertainty of measurement results affected by measurement errors. This article completes the repeatability test of the verification results according to “JJG (Meteorology) 004-2011 Automatic Weather Station Wind Speed and Direction Sensor Verification Regulations”. The author establishes a mathematical model to determine the source of uncertainty, calculates the uncertainty components item by item, and completes the analysis of the verification results of the anemometer standard device. This helps to ensure the reliability of the observation data of the meteorological wind speed sensor.
Study of Hydraulic Disturbance of Pumped Storage Unit
Authors: Li Gaohui , Wu Xumin , Cui WeiJie , Qiu WeiXin , Zhou Tianchi
Published: May 2021

The analysis of hydraulic disturbance is an important part of the analysis of the hydraulic transient process of a hydropower station. This paper introduces the relationship between the grid-connected operation mode of the power station and the hydraulic disturbance by the power station system, and performs simulation calculations under the same boundary conditions according to the hydraulic disturbance test cases, and predicts the extreme control conditions which provides the basis for the safe operation of the power station. It also provides reference for the design and calculation of similar projects.
The Study on Hydrodynamic Characteristics of Qianhai Bay in Shenzhen
Authors: Yang Yugui , Gao Shiyou , Tong Xiaolei
Published: May 2021

Based on the fixed-point observation data in Qianhai Bay of Shenzhen in May 2020, the horizontal and vertical distribution characteristics of tidal current, wave in summer near Qianhai Bay of Shenzhen are analyzed. The results show that the correlation coefficient of high and low tide level between the Qianhai Bay and Chiwan hydrological station is 0.98. The former Bay is dominated by irregular semidiurnal tidal current, which basically rotates anticlockwise. Due to the special shape of Qianwan Bay, the average velocity in the bay is small, but the maximum velocity of flood tide is 0.48m/s, the maximum velocity of ebb tide is 0.45m/s, the possible maximum velocity is 0.64m/s at the bay mouth. The average wave height is 0.07m, the normal wave direction is southwest West (WSW), and the average period is 2.9s.
Multi-time-scale nested optimal scheduling model for cascaded hydropower reservoirs
Authors: Shen Keyan , Qin Hui , Zhou Jianzhong
Published: May 2021

As more hydropower plants are in operation, it is difficult to balance the medium-and long-term benefits with the short-term benefits when developing an optimal scheme for power generation from cascaded hydropower reservoirs. And traditional models have difficulty making full use of the latest runoff forecast information. To overcome these problems, a multi-time-scale nested optimal scheduling model for cascaded hydropower reservoirs is developed. This model analyzes the level-by-level control strategy and rolling update mechanism between upper and lower level submodels. An efficient algorithm for solving the model is also given. In this study, the model is applied to four cascaded hydropower reservoirs located at the Yangtze River. The case study shows that the developed model can better coordinate the medium- and long-term benefits with the short-term benefits, make full use of the latest forecast information, and enhance the power generation efficiency of the cascaded hydropower reservoirs. Compared with the results of the existing scheduling model, the total power generation from the proposed model is improved under the same boundary conditions.
Characteristics of NDVI Temporal and Spatial Variation in the Source Area of the Yangtze River and Its Response to Hydrothermal Conditions
Authors: Dai Xitong , Yao Liqiang , Yuan Zhe , Sun Keke
Published: May 2021

vegetation cover change monitoring is the basis of regional resources and environmental carrying capacity research. Based on the data set MODIS-NDVI 2001∼2018, this paper analyzes the spatial and temporal characteristics of annual NDVI in the Yangtze River source area by using maximum synthesis method and various statistical methods. The effects of surface hydrothermal conditions on space and time were discussed. The results show that:1) the NDVI of the source area of the Yangtze River shows a significant increase trend, and only some areas of Dongyuan NDVI show a downward trend. In spatial distribution, the vegetation coverage in the source area of the Yangtze River is mainly low and medium vegetation coverage, the vegetation coverage increases gradually from northwest to southeast, and the vegetation coverage of Yushu Tibetan Autonomous region is generally higher than that of Hercynian Mongolian Tibetan Autonomous region. At above 4000 m, the vegetation coverage increases more obviously with the increase of altitude. 2) precipitation in the source area of the Yangtze River decreases gradually from southeast to northwest, the low value area is located in the north of the source area of the Yangtze River, and the high value area is located in the eastern part of the Yushu Tibetan Autonomous region. However, the spatial trend of annual mean temperature and precipitation in the source area of the Yangtze River is opposite. The precipitation tendency rate in the source area of the Yangtze River shows obvious spatial difference, the precipitation in the south source generally shows a decreasing trend, and the precipitation in the north source generally shows an increasing trend. The southwest source and east source NDVI of 3) Yangtze River source area are negatively correlated with precipitation, while NDVI and temperature are positively correlated in most areas of the Yangtze River source area, and the effect of temperature on interannual variation is stronger than that of temperature. With the increase of temperature and precipitation, the NDVI also shows an increasing trend in spatial distribution, but precipitation has a stronger effect on the spatial heterogeneity of NDVI. From this we can see that the influence of hydrothermal conditions on the interannual variation of NDVI depends on the temperature, while the effect on spatial distribution mainly depends on the precipitation.
Relationship between chloride diffusion coefficient and ASTM C1202 electric flux under different environments and durability evaluation
Authors: Dong Wenxiu , Zhou Ming
Published: May 2021

The relationship of the diffusion coefficient and charge passed is developed employing the analysis of the traditional model and 244 groups of experimental data. The differences in the types of concrete were considered to determine the variation coefficient of the diffusion coefficient in the models. Results revealed that the different environmental conditions of the concrete chloride diffusion coefficient cannot be described solely by the existing maturity method. Reasonably good agreement is observed between the experimental and computational model of this paper, thus indicating that the proposed prediction model can be successfully used to estimate the chloride diffusion coefficient. An example of a durability assessment is performed to verify the applicability of the concrete durability assessment method. The concrete durability assessment method can control the durability quality and direction of the production of concrete.
Case analysis of in-situ stress coal and gas outburst and prevention countermeasures
Authors: Wang ZHonghua
Published: May 2021

The coal and gas dynamic disasters in Fengcheng mining area are serious. There are currently 6 pairs of coal and gas outburst mines. In view of the increase in the proportion of in-situ stress-oriented outbursts in the mining area as the mining depth increases, the establishment of classified disaster control measures is proposed. Stereo gas drainage system, and proposed to explore the use of deep hole pre-splitting blasting, roof strike long drilling, hydraulic reaming, hydraulic fracturing and other new technical measures. It is of great significance to safe and efficient production in mining areas.
Influence of rare earth elements on microstructure and strengthening mechanisms of Mg-12Gd-3Y-0.5Zr magnesium alloy
Authors: Yang Xiaoming
Published: May 2021

Mechanical properties of Mg-12Gd-3Y-0.5Zr (GW123K) including tensile strength and isothermal fatigue limit were tested by MTS810 system. Experimental results show that it has higher mechanical properties at different temperatures than other magnesium alloys without rare earth elements addition. Influence of rare earth elements on its microstructure and strengthening mechanisms are disscussed in this paper. SEM and TEM analysis indicates that rare earth elements additon leads to grain refinement and restricts grain boundary sliding and fatigue crack propogation.
Ba, Co modified activated clay and their adsorption performance characterization
Authors: Yang Jie , Wang Yajun , Tian Changan , Lai Shikang , Liu Yang , Si Xiaoqiang , Zhang Qing
Published: May 2021

A series of modified activated clay composite materials were prepared by solvothermal method. The modified samples were tested and characterized by a series of instrument methods. The modified activated clay materials with good adsorption effect, simple process and low cost were synthesized by doping different metal ions. The adsorption properties of the modified activated clay materials were investigated. The results show that the (Ba, Co)-activated clay modified samples can be used as adsorbents to remove Congo red organic dye wastewater, and the activity is greatly improved compared with the activated clay, the adsorption capacity is greatly enhanced. The particle size is small, and it has good thermal stability. When the initial Congo red concentration is 100 mg/L and the adsorption time is 140 minutes, the maximum adsorption capacity of Ba-activated clay is 371 mg/g, and that of Co-activated clay is 338 mg/g.
Research on Anti-reflection Measures of Hydraulic Reaming of Low Permeability Soft Coal Seam in Goutou Coal Mine
Authors: Reng Feng
Published: May 2021

According to the C5 coal seam of gully head coal mine complex geological conditions Poor permeability gas pressure is big Coal seam gas content is high Soft coal extraction from standard time is long, etc., combined with high pressure water jet force reaming technology principle and characteristics of the gully head coal mine is put forward using the method of integration of bottom hole drill wear layer expansion technical measures to increase coal seam permeability, and within the scope of the field to carry out the experimental study. In soft coal seam through field experiment research shows that the drilling construction process, through the integration of enlarging anti-reflection technology measures, can effectively improve the exposed area of a single layer of bore, change of coal seam and the stress distribution state of joints, thus improve the wear layer drilling drainage concentration and smoke volume, shorten the wear layer drilling extraction from standard time to the success of the test for the mine and similar mine to improve coal seam permeability is to provide the basis.
Research on characteristics of coal and gas outburst in deep mines
Authors: Wang ZHonghua
Published: May 2021

The single B4 coal seam mined in Fengcheng mining area is a gently inclined medium-thick coal seam, with high gas pressure and high content, soft coal seam, low air permeability, and serious coal and outburst disasters. According to the gas occurrence characteristics of Fengcheng mining area, the characteristics and laws of 186 outburst accidents in the mining area are statistically analyzed, and the characteristics of in-situ stress coal and gas outburst are obtained. It provides theoretical guidance for the prevention and control of gas dynamic disasters in mining areas, which is of great significance to safe and efficient production in mining areas.
Experimental investigation of dynamic shear behavior of typical silt sand in Rudong Offshore Wind Farm
Authors: Xiao Xian-bo , Xu Hai-yan , Yang Xiao-nan , Xu Xue-yong
Published: May 2021

The dynamic properties of typical silt sand in offshore wind farm are closely related to the stability of offshore wind farm foundations. This study investigates the dynamic behavior of typical silt sand in Rudong offshore wind farm of Jiangsu province based on dynamic triaxial testing and resonant column testing. Specifically, the dynamic properties including dynamic modulus, damping ratio, dynamic strength, dynamic strain, dynamic pore water pressures and stress-strain relationship of the silt sand are studied. It is found that the accumulated strain and pore pressure continuously increase with the increased cyclic number, which eventually leads to liquefaction failure. Soil specimen with a higher confining pressure is more likely to reach liquefaction with a lower number of loading cycles. It is also found that the Hardin-Drnevich model can be used to reflect the mechanism of the effect of confining pressure on the dynamic behavior of the silt sand. The dynamic shear modulus and damping ratio decrease and increase exponentially with the increase of shear strain, respectively.
Adaptability Analysis for Sand Proppant to Conglomerate Oil Reservoir in Well-block MA 131 of Xinjiang Oil Field
Authors: Chen Ang , Zhang Zhao , Tang Wei , Wang Lei , Yu Huiyong
Published: May 2021

SRV (Simulated Reservoir Volume) in horizontal well is a main instrument for exploiting dense conglomerate oil reservoir in Ma Lake. The expenses of proppant are about 25% to 30% of the total SRV costs. In order to reduce costs and improve efficiency, it is inevitable to replace ceramic proppant with quartz sand, because the price of quartz sand is significantly lower than ceramic proppant. With Well-block Ma 131 as an object, this paper analyzes post-SRV production result of the existing alternative sand well; creates simple fracture and curved fracture model based on features of conglomerate oil reservoir; plots required conductivity of the target area through simulation and calculation; and analyzes adaptability of sand proppant to the target area based on conductivity data of sand proppant. The results indicate that the required conductivity of Well-block Ma 131 changes within 10 and 35 D·cm; quartz sand can accommodate production demands completely when closure pressure is low; and required conductivity can be realized through improving sanding concentration when the closure stress is high.
Sediment Transport and Diffusion in the Yellow River Estuary in 2018 Based on Numerical Analysis
Authors: Liangchao Ma , Caodong Jiang , Dongfeng Li , Hongwu Zhang , Zihao Li
Published: May 2021

As the river with the highest sediment concentration in the world, the Yellow River carries a huge amount of sediment in the Yellow River estuary every year. The Yellow River estuary extends and forms a forward extension zone of land-sea interaction. It is of great significance to fully understand the movement and diffusion law of the sediment from the Yellow River to the sea and keep the balance of scouring and silting. A two-dimensional mathematical model from Luokou to the Yellow River estuary and Bohai Bay was established, and the diffusion law of sediment movement in the Yellow River flood and dry season was obtained by simulation calculation. The influencing factors of sediment movement and diffusion mainly include flood magnitude, sea level tide fluctuation and tidal current direction. The analysis of the movement range and diffusion rate of sediment under different conditions provides a reference basis for the control of the sand bar in the Yellow River estuary and the balance of scouring and silting in the lower reaches of the Yellow River.
Research on Biological Protection Engineering Construction on Downstream Levee of the Yellow River
Authors: Zhanjun Yuan , Feng Zhang
Published: May 2021

As an integral part of flood control engineering system, biological protection measures have always been attached great importance to by management units at all levels. Taking the calculation of the width of the breaktide belt in the lower reaches of the Yellow River as an example, this paper studies the great role of the protection works in ensuring the safety of the Yellow River project protection and the construction of water ecological civilization.