Analysis of Fatigue Calculation Methods for Variable Loading Stationary Operating Modes to Validate Domestic CAE Software — APM StructFEM

The paper introduces the results of studying the possibilities and accuracy of numerical solutions of fatigue strength in the domestic software product APM StructFEM and in the well-known ANSYS software, as well as the results of analytical calculations for similar cases. The analysis of the accuracy of the obtained solutions is carried out on the example of the analysis of a section of the pipeline, for different variants of loadings and for a combination of these loadings. The areas of the most effective solutions obtained for various methods of reducing the operating variable modes to sinusoidal loading are determined. The study is caused by the implementation in the Russian Federation of an import substitution program in the field of strategic technologies, which can rightfully include computer solutions for engineering analysis.

Multi-Objective Nonlinear Programming Model for Reducing Octane Number Loss in Gasoline Refining Process Based on Data Mining Technology

To simultaneously reduce automobile exhaust pollution to the environment and satisfy the demand for high-quality gasoline, the treatment of fluid catalytic cracking (FCC) gasoline is urgently needed to minimize octane number (RON) loss. We presented a new systematic method for determining an optimal operation scheme for minimising RON loss and operational risks. Firstly, many data were collected and preprocessed. Then, grey correlative degree analysis and Pearson correlation analysis were used to reduce the dimensionality, and the major variables with representativeness and independence were selected from the 367 variables. Then, the RON and sulfur (S) content were predicted by multiple nonlinear regression. A multi-objective nonlinear optimization model was established with the maximum reduction in RON loss and minimum operational risk as the objective function. Finally, the optimal operation scheme of the operating variable corresponding to the sample with a RON loss reduction greater than 30% in 325 samples was solved in Python.

Pengaruh Operating Leverage dan Struktur Modal terhadap Kinerja Keuangan pada Perusahaan Go Publik Sektor Property Dan Real Estate

The company's financial performance is a benchmark for the success of managers in running a company. This study aims to determine the effect of operating leverage and capital structure partially or simultaneously on financial performance in the Go Public Company Property and Real Estate Sector. The sampling technique in this study is to use purposive sampling. Data analysis method in this study uses multiple regression analysis which is used to determine the effect of independent variables on the dependent variable together (F test) and partially (t test) and R2 test (coefficient of determination) carried out to find out how much influence the operating variable leverage (DOL) and capital structure (DER) on financial performance variables (ROA). From the t test results it is known that the variable operating leverage (DOL) and capital structure variables (DER) with a significance value of 0.044 and 0.015

Reliability Analysis of Forest Machines Due to FMEA Method

The article deals with the research of operational reliability of forest felling machines with the method FMEA (Failure Mode and Effect Analysis) and its implementation for observed machines in the organization. Forwarders 810D by John Deere were chosen for this research. The research was realized in real operational conditions. Application of the FMEA method allows flexibility in case of unexpected situations and optimization of human potential abilities. FMEA tool is a tool preventing outages operational reliability and preventive tool for ensuring the maintenance of facilities. This paper explores and verifies the operational reliability theory in practical real-world conditions, resulting in a reduction in operating (variable) costs, minimization of failures and readiness and increased performance of observed machines.

A review on thermochemical treatment of biomass: Pyrolysis of olive mill wastes in comparison with other types of biomass

Each year, a great quantity of olive oil is produced by the unit mill of trituration. This activity generates two by-products named olive mill wastewater and olive mill solid waste representing major potential waste and environmental problem. However, there is growing interest in pyrolysis as a technology to treat wastes to produce valuable oil, char and gas products. The major important aim of waste pyrolysis is to produce liquid fuel or bio-oil, which is easy to store, transport and can be an alternative to energy source. The key influence on the product yield is the type of biomass feedstock and operating parameters (especially temperature and heating rate). It is important to investigate the effect of variables on response yield and impulse about their optimization. This study reviews operating variable from existing literature on olive mill wastes (OMSW and OMWW) in comparison with various types of biomass. The major operating variables include type of feedstock, final temperature of pyrolysis, heating rate and particle size. The scale of this paper is to analyse the influence of operating parameters on production of pyrolysis bio-oil, char and gaseous products.

Flue gases thermal emission concentration during waste biomass combustion in small combustion device with manual fuel supply

he aim of the experiments is determination of emission concentrations in the observed substances produced in exhaust gas during combustion of various mixtures of waste biomass compacted samples. The samples were pressed into the form of briquettes with a diameter of 65 mm. During the actual measurements the following parameters were monitored: emissions of carbon dioxide (CO₂), carbon monoxide (CO), nitrogen oxides (NO_x) and flue gas temperature depending on the excess air coefficient. Measurements of emission parameters were carried out in storage heater fireplace with nominal heat output of 8 kW. During the measurements high concentrations of carbon monoxide in excess of the value of 5,000 mg/m³ were determined, especially in the samples of waste from corn cleaning and wheat straw. The results show an excess air factor optimum adjustment on value 3, where the combustion device achieves optimum parameters of CO and NO_x emissions. The results of emission measurements confirmed that the excess air is a very important operating variable which affects both monitored emissions concentrations and the combustion temperature in the fireplace.

Ultrahigh-Temperature Continuous Reactors Based on Electrothermal Fluidized Bed Concept

Authors introduce an ultrahigh-temperature (i.e., 2500–3000 °C) continuous fluidized bed furnace, in which the key operating variable is specific electrical resistance of the bed. A correlation has been established to predict the specific electrical resistance for the natural graphite-based precursors. Fluid dynamics models have been validated with the data from a fully functional prototype reactor. Data collected demonstrated that the difference between the calculated and measured values of specific resistance is approximately 25%; due to chaotic nature of electrothermal fluidized bed processes, this discrepancy was deemed acceptable. Optimizations proposed allow producing natural graphite-based end product with the purity level of 99.98 + wt. %C for battery markets.

Influence of engine operating variable on combustion to reduce exhaust emissions using various biodiesels blend

This study focused mainly on the behavior of biodiesel operated under various operating conditions.