The Mathematical Models of the Operation Process for Critical Production Facilities Using Advanced Technologies

The paper presents data on the problems of monitoring and diagnosing the technical conditions of critical production facilities, such as torpedo ladle cars, steel ladles. The accidents with critical production facilities, such as torpedo ladle cars, lead to losses and different types of damages in the metallurgical industry. The paper substantiates the need for a mathematical study of the operation process of the noted critical production facilities. A Markovian graph has been built that describes the states of torpedo ladle cars during their operation. A mathematical model is presented that allows determining the optimal frequency of diagnostics of torpedo ladle cars, which, in contrast to the existing approaches, take into account the procedures for preventive diagnostics of torpedo ladle cars, without taking them out of service. Dependence of the utilization coefficient on the period of diagnostics of PM350t torpedo ladle cars was developed. The results (of determining the optimal period of diagnostics for PM350t torpedo ladle cars) are demonstrated. The system for automated monitoring and diagnosing the technical conditions of torpedo ladle cars, without taking them out of service, has been developed and described.

Research on Irrigation Water Efficiency of Guizhou Province Based on SFA

The measurement of farmland irrigation water efficiency is an important part of the evaluation of agricultural water saving. Since the method of econometrics research on the relationship between input and output was introduced to the evaluation of irrigation water efficiency, it has provided a new perspective for evaluating irrigation water efficiency. This study takes Guizhou in southwest China as an example, using the SFA method to calculate the technical efficiency of food production and irrigation water from 2011 to 2018, and compares the technical efficiency of irrigation water with the measured irrigation water effective utilization coefficient analysis. The analysis shows that: (1) Guizhou’s multi-year average irrigation water technical efficiency value is 0.730, and the difference between cities is large. 20.8% of the urban irrigation water technical efficiency is lower than the average level, and there is a large water saving potential; (2) The correlation coefficient between the irrigation water technical efficiency calculated by the SFA method and the measured irrigation water effective utilization coefficient is 0.804, which is highly positively correlated, and the simulation calculation validity is 70.6%; (3) The SFA method can provide an effective reference for the study of the change trend of the effective utilization coefficient of farmland irrigation water in the absence of measured data.

Applied Systems Theory: Wind Turbine Output Power Prediction based on Wind Energy Utilization Coefficient

The output power of a wind turbine is the most critical variable reflecting the operating status of the turbine. To improve the interpretability of the prediction model, a segmented output power method based on wind energy utilization coefficient is established. First, the wind energy conversion system of the wind turbine is given, and the SCADA data of a wind turbine is visually analyzed. Then it is proposed to separate the data into three groups according to different operating regions of wind turbines: the Maximum Power Point Tracking region, the rotator speed control region, and the power control region. In the Maximum Power Point Tracking region, wind energy utilization coefficient is found by a fitted cubic polynomial of the tip speed ratio. In the rotator speed control region, a modeling method for determining wind energy utilization coefficient through dynamic labels is designed. In the power control region, the output power is kept at the rated value. Finally, the 3 models are connected so that time-series data can be handled. The SCADA data of a 2.1MW wind turbine is used to verify the above models. The performance of these models is given in the form of Root Mean Square Error, indicating that the output power predicted by this method has good accuracy.The segmented output power model based on wind energy utilization coefficient can simulate the operation process of wind turbines, and has good accuracy and interpretability.

Nutrient stock in the forest component in a crop-livestock-forest integration system in Central Brazil

Integrated systems are sustainable alternatives, where agricultural, forestry, and/or livestock components occupy a given area through consortium, rotation, or succession. Considering this importance, this work had as objective to quantify the stock of above-ground biomass (wood, leaves, bark, and branches) of 6 years Eucalyptus urograndis in a crop-livestock-forest integration system (CLFS). It also involved calculation of the nutrient utilization in biomass conversion through the Biological Utilization Coefficient (BUC) and design of different export scenarios of these nutrients through the harvest in order to calculate the reduction in the demand for inputs. Nutrient stock was determined from the biomass sampled in the field and from the plant tissue analysis. It is verified that the highest concentrations of macronutrients are present in wood component, except for Ca. The concentration gradient of micronutrients was: Leaves> Fe> Mn> B> Cu> Zn; Branches and Bark: Fe> Mn > B> Zn> Cu; and wood: Mn > Fe > Zn > Cu > B. Considering BUC conversion rate decline, it presented the following order: S> P> Mg> Ca> N> K for macronutrients and B> Cu> Zn> Fe> Mn for micronutrients. The most appropriate export scenario was to harvest only timber component to minimize the nutritional export. The nutritional dynamics within the eucalyptus are altered according to the diametric structure of the trees. The nutritional elements are concentrated in different compartments according to the availability and need of the plants.

Analysis of Factors Influencing Effective Utilization Coefficient of Irrigation Water in the Manas River Basin

The factors influencing the effective utilization coefficient of irrigation water are not understood well. It is usually considered that this coefficient is lower in areas with large-scale irrigation. With this background, we analyzed the effective utilization coefficient of irrigation water using the analytic hierarchy process using data from 2014 to 2019 in Shihezi City, Xinjiang. The weights of the influencing factors on the effective utilization coefficient of irrigation water in different irrigation areas were analyzed. Predictions of the coefficient’s values for different years were made by understanding the trends based on the grey model. The results show that the scale of the irrigation area is not the only factor determining the effective utilization coefficient of irrigation water. Irrigation technology, organizational integrity, crop types, water price management, local economic level, and channel seepage prevention are the most critical factors affecting the effective use of irrigation water. The grey model prediction results show that the effective utilization coefficient of farmland irrigation water will continuously increase and reach 0.7204 in 2029. This research can serve as a reference for government authorities to make scientific decisions on water-saving projects in irrigation districts in terms of management, operation, and investment.

Functional state dynamics in cross-country skiers in the summer and autumn preparatory phase

Background and Study Aim. To study changes in the functional state of professional Russian cross country skiers in the course of the preparatory phase and their effects on their competition ratings. Materials and methods. In this study we examined 10 cross-country skiers. The functional state was assessed through a maximal load bicycle ergometer test, coordination and special performance tests. Concentrations of lactate and cortisol were checked in the blood plasma of participants. Results. The training effects on general physical preparedness and special physical preparation in September in comparison with June were observed as an increased number of pull-ups on a pull-up bar (by 14%) and decreased time of the roller ski test (by 4%). In autumn higher systolic (by 11%) and diastolic (by 10%) arterial blood pressure levels, higher levels of plasma lactate and cortisol (by 48% and 64%, respectively) were detected (p<0.05). At anaerobic threshold the following increased: total performance capacity (by 13%), oxygen consumption (by 14%), watt pulse (by 5%), respiratory minute volume, oxygen utilization coefficient, and oxygen pulse (by 15%) (p<0.05-0.01) at rest before the ergometer test. In September upon completion of the ergometer test we observed an increase of oxygen pulse (by 7%), watt pulse (by 10%), and oxygen utilization coefficient (by 24%) (p<0.05). In autumn at the 5th minute of recovery after the ergometer test the heart rate recovered 11% faster, blood lactate – 29% faster, and the oxygen utilization rate increased by 15% (p<0.05-0.01). In June no statistically significant correlations were found between the studied indicators. In autumn statistically significant correlations appeared between indicators of the cardiorespiratory system, physical performance, and coordination test time. Conclusions. The package program for the summer-autumn training period contributes to the improvement of the functional status of the cross-country skiers and to the development of physical power, endurance, increased strength of the upper limbs, increased speed of movement on roller skis, faster and more complete recovery of physiological and biochemical parameters.

Calculation and Analysis of Effective Utilization Coefficients of Farmland Irrigation Water in Guizhou Province

Effective utilization coefficient of farmland irrigation water is an important index for water-saving level evaluation. Tracked calculation of effective utilization coefficients of farmland irrigation water as well as quantitative and qualitative analyses in terms of its scientificity and rationality have a guiding role in sustainable development of water-saving irrigation. This paper sets out to calculate the effective utilization coefficients of farmland irrigation water in Guizhou Province in 2019 and evaluate rationality of the results. More than that, some internal factors influencing utilization coefficients are also investigated, and relevant proposals are put forward, in a view to providing technical support for water-saving irrigation planning and scientific water distribution.

Расчет аэродинамических характеристик ветроэнергетической установки с лопастями в виде вращающихся цилиндров

The results of studies on determining the speed of a wind power plant and calculating the wind energy utilization coefficient of a rotating cylinder constant cross-section with a smooth surface are presented. With the help of experimental and theoretical methods, studies of the main aerodynamic characteristics the efficiency of a wind power plant with blades in the form of rotating cylinders were carried out. The changes in the aerodynamic parameters of the flow were 2 m/s and higher. The results showed that the value of the wind energy utilization coefficient decreases with an increase in the speed of the incoming flow. It is experimentally established that the value of the speed a wind power plant decreases with an increase in the Reynolds number.