The Determinant Factors of Earnings Persistence

The purpose of this research is to provide empirical evidence about the effect of operating cash flow, sales volatility, cash flow volatility, operating cycle, and book tax difference on earnings persistence. The company used in this research is manufacturing company listed in Indonesia Stock Exchange (IDX) from 2016 until 2020. Samples of this research were selected based on the purposive sampling method and resulted in 43 companies, therefore the data used for this research amounting to 215 data. The data obtained from these samples were analyzed using multiple regression method. The result of this research show that operating cycle have influence on earnings persistence. While operating cash flow, sales volatility, cash flow volatility, and book tax difference have no influence on earnings persistence.

The search for baseline events for assessing the safety of nuclear refueling operations at nuclear power plants

The relevance of the topic of the safety of nuclear refueling operations is associated with the specificity of exploitation of RBMK units. One of the most hazardous, from the perspective of accidents at modern nuclear power plants, is the process of nuclear fuel reloading. The operations on rearrangement of fuel cartridges entail the risk of fuel damage, and thus, the likelihood of the release of radioactive substances exceeding the permissible limits. The process of reloading RBMK, if the reactor is at full capacity, consists of the vast number of complex operations characterized by a range parameters. Non-observance of the criteria for carrying out operations, or if the parameter values exceed permissible limits, with high probability leads to an accident. This article explores the possibility of application of formalized approach towards determination of the baseline events that may cause accidents for the purpose of the development of essential protection instruments. The formal approach would allow detecting the excessiveness in protection instruments on the existing blocks, as well as revealing the accident situations that cannot be prevented using these protection instruments. The author formulated systemic approach towards comprehensive assessment of the accident rate of structurally complex systems. Adaptation of this method relative to REM allows systematizing the search for baseline vents that entail uncontrolled situations, as well as optimizing the protection instruments that would ultimately enhance reliability of the system, simplify the exploitation process, and reduce the time of operating cycle of the controller for processing of the protection.

ОБЛІКОВО-АНАЛІТИЧНИЙ ІНСТРУМЕНТАРІЙ УПРАВЛІННЯ ОБОРОТНИМ КАПІТАЛОМ ПІДПРИЄМСТВ В УМОВАХ ГЛОБАЛЬНИХ ВИКЛИКІВ

Global challenges cause many social and economic transformations in the economic entities activities, especially related to current assets, including disruptions in the inventories supply, increasing receivables due to breach of payment discipline of counterparties due to reduced sales of their own products during quarantine measures, reduced consumer solvency, devaluation of fiat money, etc., which makes it impossible to repay the debt on time, and the growth of receivables leads to the inability to repay their own accounts payable. The aim of the research is improvement the methodology and organization of accounting, analysis and audit of enterprise current assets in the face of global challenges. The subject of the research is the process of current assets formation and usage of PJSC "FED". The methods of the research: observation, comparison, analysis, generalization and formalization, rationing, forecasting. The hypothesis of the research: improving the process of accounting, analysis and internal audit of current assets will increase the efficiency of their formation and usage. The statement of basic materials. For increasing the efficiency of the process of current assets formation and usage in the context of global challenges, a conceptual approach to their accounting and analysis has been developed. The forecasting of current assets value of PJSC "FED" for the next two years was carried out with the help of trend analysis, as a result of which it was determined that the value of current assets will increase. For optimization the inventories formation and usage, the ABC-analysis has been implemented, which makes possible to accurately calculate the required volumes of purchases by different product groups; to exclude from the nomenclature illiquid positions, which makes possible to release cash frozen in these goods, reduce warehousing costs, increase inventory turnover; ensure sales growth. To improve the system of accounting for receivables at PJSC "FED" it is proposed to open six sub-accounts to account 38 "Provision for doubtful debts", as well as to improve analytical accounting by introducing groups of debtors in terms of non-repayment of receivables. Differentiation of ways to increase the efficiency of current assets formation and usage depending on the stage of the operating cycle is proposed. Also it is proposed to conduct current assets internal audit, which will verify the security of current assets, compliance with the rules and requirements of their accounting, documentation, reliability of information. The originality and practical significance of the research: originality lies in the development of methodological principles of production enterprise current assets accounting and analysis, identifying the lack of sources of own working capital. The conclusions and proposals obtained as a research results can be used in the practice of the production enterprise of PJSC "FED" to improve the efficiency of current assets accounting, analysis and audit. Conclusions. The proposed measures will help to improve the efficiency of current assets formation and usage, in particular, to reduce accounts receivable and improve the inventories formation quality

Influence of limiting the duration of the armature winding current on the operating indicators of a linear pulse electromechanical induction type converter

Introduction. Linear pulse electromechanical converters of induction type (LPECIT) are used in many branches of science and technology as shock-power devices and electromechanical accelerators. In them, due to the phase shift between the excitation current in the inductor winding and the induced current in the armature winding, in addition to the initial electrodynamic forces (EDF) of repulsion, subsequent EDF of attraction also arise. As a result, the operating indicators of LPECIT are reduced. The purpose of the article is to increase the performance of linear pulse electromechanical induction-type converters when operating as a shock-power device and an electromechanical accelerator by limiting the duration of the induced current in the armature winding until its polarity changes. Methodology. To analyze the electromechanical characteristics and indicators of LPECIT, a mathematical model was used, in which the solutions of equations describing interrelated electrical, magnetic, mechanical and thermal processes are presented in a recurrent form. Results. To eliminate the EDF of attraction between the LPIECIT windings, it is proposed to limit the duration of the induced current in the armature winding before changing its polarity by connecting a rectifier diode to it. It was found that when the converter operates as a shock-power device without limiting the armature winding current, the value of the EDF pulse after reaching the maximum value decreases by the end of the operating cycle. In the presence of a diode in the armature winding, the efficiency criterion, taking into account the EDF pulse, recoil force, current and heating temperature of the inductor winding, increases. When the converter operates as an electromechanical accelerator without limiting the armature winding current, the speed and efficiency decrease, taking into account the kinetic energy and voltage of the capacitive energy storage at the end of the operating cycle. In the presence of a diode in the armature winding, the efficiency criterion increases, the temperature rise of the armature winding decreases, the value of the maximum efficiency increases, reaching 16.16 %. Originality. It has been established that due to the limitation of the duration of the armature winding current, the power indicators of the LPECIT increase when operating as a shock-power device and the speed indicators when the LPECIT operates as an electromechanical accelerator. Practical value. It was found that with the help of a rectifier diode connected to the multi-turn winding of the armature, unipolarity of the current is ensured, which leads to the elimination of the EDF of attraction and an increase in the performance of the LPECIT.

Influence of the Final Ratio on the Consumption of an Electric Vehicle under Conditions of Standardized Driving Cycles

Electric vehicles must improve their electric drive system efficiency and effectively use their limited energy to become a viable means of transportation. As such, these technologies have undergone substantial improvements from their initial conception. More efficient powertrains, together with improved storage technologies, have enabled more extended autonomy. However, from an engineering perspective, these systems are still a key area of research and optimization. This work presents a powertrain optimization methodology, developing energy savings and improving the performance of the electric vehicle by focusing on the differential. The proposed methodology includes a study of the dynamics of the electric vehicle and the generation of a mathematical model that represents it. By simulating the vehicle and varying the final ratio of the differential, a significant optimization for energy savings is obtained by developing a standardized driving cycle. In this case, NEDC, WLTC-2, and WLTC-3 test cycles are used. The results show that a short ratio improves performance, even if this implies a larger torque from the prime mover. Depending on the operating cycle used, an energy-saving between 3% and 8% was registered. An extended energy autonomy and an increment in the life-cycle of the batteries are expected in real driving scenarios.

Control of characteristics of closed gas turbine plants of submarines propulsion complexes

Подводная техника особенно нужна при работе и снабжении подводными судами объектов на Арктическом шельфе вдоль Северного морского пути, связанного с преодолением ледовых полей. Среди различных типов энергетических установок для подводной техники перспективны замкнутые газотурбинные установки (ЗГТУ), способные в одноконтурном варианте работать на углеводородных типах топлива. В качестве окислителя можно использовать воздух, который на судах можно хранить в сжатом виде. В этом случае не нужна специальная береговая инфраструктура, ограничивающая дальность плавания подводной техники. За основу базовой схемы ЗГТУ принят газотурбинный двигатель (ГТД) с регенерацией (Р) теплоты, как более экономичный по сравнению с ГТД простого цикла, и схемы которого характерны для микрогазотурбинных двигателей. Также рассмотрены ЗГТУ с турбокомпрессорным утилизатором (ТКУ) и регенерацией теплоты как более экономичные и обладающие удельной мощностью в 1,3…1,5 раза большей, чем в ЗГТУ с Р. Определены характеристики ЗГТУ на переменных режимах, так как подводная техника используется при исследовательских, технологических и транспортных работах при частичных нагрузках и различных видах нагружения. Для улучшения экономичности ЗГТУ на режимах частичного нагружения предложено применить регулируемый сопловой аппарат (РСА) в свободной силовой турбине. На частичных нагрузках посредством РСА можно перераспределить теплоперепад между турбинами, изменить расход газа через турбины, приблизить регулирование к количественному типу. При этом наблюдается увеличение эффективного КПД относительно других способов регулирования при уменьшении мощности двигателя и рост начальной температуры газа, который приближает параметры рабочего цикла двигателя к номинальным значениям. Underwater equipment is especially needed when operating and supplying objects by submarines on the Arctic shelf along the Northern Sea Route associated with ice fields overcoming. Among the various types of power plants for underwater equipment, closed gas turbine plants (CGTP) are promising, capable of operating in a single-circuit version on hydrocarbon types of fuel. Air can be used as an oxidizing agent, which can be stored compressed on ships. In this case, there is no need for a special coastal infrastructure that limits the range of navigation of underwater equipment. A gas turbine engine (GTE) with heat regeneration (R) is adopted as the basis for the basic scheme of CGTP, as it is more economical in comparison with a simple cycle GTE, and the schemes of which are typical for microgas turbine engines. Also considered are CGTP with a turbocompressor utilizer (TCU) and heat regeneration as more economical and having a specific power 1.3...1.5 times higher than in CGTP with R. The characteristics of CGTP in variable modes are determined, since underwater equipment is used in research, technological and transport works at partial modes and various types of loading. To improve the efficiency of CGTP in partial loading modes, it is proposed to use a variable area nozzle (VAN) in a free power turbine. At partial loads, by means of VAN, it is possible to redistribute the heat drop between the turbines, change the gas flow rate through the turbines, and bring the regulation closer to the quantitative type. At the same time, there is an increase in the effective efficiency relative to other control methods with a decrease in engine power and an increase in the initial gas temperature, which brings the parameters of the engine operating cycle closer to the nominal values.

Finite element simulation of residual stresses and failure mechanism of plasma sprayed thermal barrier coatings considering real interface

In order to increase the efficiency of gas turbine engines, which are used for propulsion and electricity generation, the turbine inlet temperature (TIT) has to be as high as possible. Using Thermal Barrier Coatings (TBC) allows the metallic internal components to operate at elevated temperature near to its melting temperature. Thermally growing oxide induces cracks formation in the top coat that may lead to complete failure TBC due to spallation. This research aims at investigating the development of the stresses and critical cites that have possibility of crack nucleation due to thermal mismatch during operating cycle of a typical plasma sprayed TBC. A true finite element model was developed based on a scanning electron microscope image taking the advantage of a commercial finite element package (ABAQUS) and image processing techniques. The model including the effect of creep on all layers and plastic deformation of BC, TGO and substrate. The results show that unlike common unit cell models in literature, a better understanding can be achieved by having a model based in an SEM image that represents the real geometry.

Neutronic Analysis of The SMART Modular Reactor Fuel Using SRAC 2006

Neutronic analysis of The SMART modular reactor fuel using SRAC 2006 has been carried out. Electrical energy is important today because the need is increasing along with the increase in human population, advanced technology and the economy. On the other hand, there are demands from the community for the clean, efficient and consistent energy. This is the reason why nuclear power plants are considered as one of the candidates for electrical energy suppliers in Indonesia in particular. This study evaluates a SMART reactor with Gadolinium as the burnable absorber material. The two kinds of fuel assembly were analyzed using the SRAC 2006 code system with the JENDL 4.0 as nuclear data library. This study aims to observe the neutronic characteristics of the fuel assembly designs according to the reference used. The results of the study show that of all types of fuel assemblies used can reach criticality at the beginning of the operating cycle and last up to 3 till 5 years when it finally reaches subcritical condition. Another parameter observed is the conversion ratio value, which from this study is in accordance with the characteristics of the conversion ratio for thermal reactors.