With the increasingly customized product requirements of customers, the manufactured products have the characteristics of multi-variety and small-batch production. A high-quality production scheduling scheme can reduce energy consumption, improve production capacity and processing quality of the enterprise. The high-dimensional many-objective green flexible job shop scheduling problem (Ma-OFJSSP) urgently needs to be solved. However, the existing optimization method are difficult to effectively optimize the Ma-OFJSSP. This study proposes a many-objective flexible job shop scheduling model. An optimization method SV-MA is designed to effectively optimize the Ma-OFJSSP model. The SV-MA memetic algorithm combines an improved strength Pareto evolution method (SPEA2) and the variable neighborhood search method. To effectively distinguish the better solutions and increase the selection pressure of the non-dominated solutions, the fitness calculation method based on the shift-based density es... [more]

In this article, the previously unrecognized contributions of Pierre Duhem and Ladislavus Natanson in thermodynamics are shown. The mathematical remodelling of a few of their principal ideas is taken into consideration, despite being neglected in the literature. To emphasize these ideas in an appropriate epistemological order, it would be crucial to first revalue and reconstruct some underrepresented parts of the proceedings process through which Duhem and Natanson created their thermodynamics. Duhem and Natanson’s scientific works are against the background of modern continuum mechanics, presenting relevant approaches. In line with the long-held beliefs of many French and Polish researchers, the article mentions that Duhem and Natanson’s ideas dated back to one century ago. Both scientists were qualified in the same Royal Way, which in this case includes chemistry, mechanic of fluid and solid, electro-chemistry, thermodynamics, electrodynamics, and relativistic and quantum mechanics.... [more]

Power generation technologies are essential for modern economies. Modal Analysis (MA) is advanced but well-established method for monitoring of structural integrity of critical assets, including power ones. Apart from classical MA, the Operational Modal Analysis approach is widely used in the study of dynamic properties of technical objects. The principal reasons are its advantages over the classical approach, such as the lack of necessity to apply the excitation force to the object and isolate it from other excitation sources. However, for industrial facilities, the operational excitation rarely takes the form of white noise. Especially in the case of rotating machines, the presence of rotational speed harmonics in the response signals causes problems with the correct identification of the modal model. The article presents a hybrid approach where combination of results of two Operational Modal Analyses and Experimental Modal Analysis is performed to improve the models’ quality. The pr... [more]

The inconsistent irradiance, temperature, and unexpected behavior of the weather affect the output of photovoltaic (PV) systems, classified as partial or complex partial shading conditions. Under these circumstances, obtaining the maximum output power from PV systems becomes problematic. This paper proposes a population-based optimization model, the horse herd optimization algorithm (HOA), inspired by natural behavior, to solicit the maximum power under partial or complex partial shading conditions. It is an intelligent strategy inspired by the surprise pounce-chasing style of the horse herd model. The proposed technique outperforms the standard in different weather conditions, needs less computational time, and has a fast convergence speed and zero oscillations after reaching a power point’s maximum limit. A performance comparison of the HOA is achieved with conventional techniques, such as “perturb and observe” (P&O), the bio-inspired adaptive cuckoo search optimization (ACS), partic... [more]

To mitigate the fast-growing demand of electrical energy, the use of renewable energy resources, e.g., solar and wind, can offer an environmentally friendly and sustainable solution. Due to their intermittent nature, the grid connected operation of renewable energy resources provides a better performance compared to the standalone operation. However, the massive penetration of power electronic inverter/converter-interfaced renewable resources in power systems introduces new issues, such as voltage and frequency instabilities, because of their inherent low inertia properties. As a consequence, these issues may lead to serious problems, such as system blackouts. Therefore, there is an immediate demand to solve these new issues and ensure the normal performance of the power system with the large penetration of renewable energy resources. To achieve this, grid connected inverters/converters are designed to address these problems and behave as synchronous generators, which is possible with... [more]

This paper suggests a heat recovery concept that is based on preheating/precooling the cold/hot fresh outside air by means of the relatively hot/cold exhaust air in winter/summer weather conditions. To investigate the feasibility of such a concept, an experimental setup is established to simulate conditions similar to an All-Air HVAC system. The prototype consists of a 6.7-m3 air-conditioned chamber by means of a split unit of 5.3-kW capacity. The heat recovery module consists of a duct system that is used to reroute the exhaust air from a conditioned chamber to flow through the fin side of a fin-and-tube heat exchanger of crossflow type. At the same time, outside, fresh air is flowing through the tube side of the fin-and-tube heat exchanger. A parametric study is performed to assess the amount of heat that can be recovered by varying the mass flow rates on both the duct and heat exchanger sides. The results show that up to 200 W of power can be saved for an exhaust flow rate of 0.1 kg... [more]

In this paper, a method of efficient hydrogen production using low-power electrolysis based on pre-magnetic polarization was proposed in order to improve the rate of hydrogen production by water electrolysis, with reduced energy consumption, molecular polarity, and stress−strain characteristics of distilled water under the condition of a pre-magnetic field. By constructing a microphysical model of hydrogen proton energy-level transition and a macroscopic mathematical model corresponding to magnetization vector-polarization hydrogen proton concentration in the pre-magnetic field, the ionic conductivity, electrolyte current density, interelectrode voltage, and hydrogen production efficiency under a varying magnetic field were qualitatively and quantitatively analyzed. In addition, an adjustable pre-magnetic polarization hydrolyzing hydrogen production test platform was set up to verify the effectiveness of the proposed method. The repeated test results, within a magnetic field strength r... [more]

Marine−terrestrial transitional Permian shales occur throughout South China and have suitable geological and geochemical conditions for shale gas accumulation. However, the Permian shales have not made commercial exploitation, which causes uncertainly for future exploration. In this study, high-pressure methane (CH4) adsorption experiments were carried out on the Permian shales in the Lower Yangtze area, and the influences of total organic carbon (TOC) content and temperature on adsorption parameters were investigated. The characteristics and main controlling factors of methane storage capacity (MSC) of the Permian shales are discussed. The results show that the maximum adsorption and the adsorbed phase density of these Permian samples are positively correlated with TOC contents but negatively correlated with temperatures. The pores of organic matter in shale, especially a large number of micropores and mesopores, can provide important sites for methane storage. Due to underdeveloped p... [more]

The results of numerical simulations of transient heat transfer in the barrel wall of a 35 mm caliber cannon for a single shot and the sequences of seven shots and sixty shots for chosen barrel steels are presented. It was assumed that the cannon barrel was made of one of the three types of steel: 38HMJ (1.8509), 30HN2MFA and DUPLEX (1.4462). To model the thermal phenomena in the barrel, the barrel wall material was assumed to be homogeneous and the inner surface of the barrel had no protective chromium or nitride layer. The calculations were made for temperature-dependent thermophysical parameters, i.e., thermal conductivity, specific heat and thermal expansion (in the range from RT up to 1000 °C) of the selected barrel steels. A barrel with a total length of 3150 mm was divided into 6 zones (i = 1, …, 6) and in each of them, the heat flux density was calculated as a function of time q˙i(t) on the inner surface of the barrel. Using lumped parameter methods, an internal ballistic code... [more]

This paper presents a sliding mode fuzzy control approach for industrial robots at their static and near static speed (linear velocities less than 5 cm/s). The extended Kalman filter with its covariance resetting is used to translate the coordinates from Cartesian to joint angle space. The translated joint angles are then used as a reference signal to control the industrial robot dynamics using a sliding mode fuzzy controller. The stability and robustness of the proposed controller is proven using an appropriate Lyapunov function in the presence of parameter uncertainty and unknown dynamic friction. The proposed controller is simulated on a 6-DOF industrial robot, namely the Universal Robot-UR5, considering the maximum allowable joint torques. It is observed that the proposed controller can successfully control UR5 under uncertainties in terms of unknown dynamic friction and parameter uncertainties. The tracking performance of the proposed controller is compared with that of the slidin... [more]

LNG (Liquefied Natural Gas) vaporizing stations are usually built in the cities and towns, and the BOG (Boiled Off Gas) pressurizing system is a very important element. In the pressurizing system, the severe vibration of the low-temperature reciprocating compressor may lead to a failure of the pipeline system and the equipment. Therefore, this paper analyzes the stress and pressure pulsation of the BOG compressor piping system in the LNG vaporizing station. The beam model was used to establish the pipe model. The static, harmonic and modal analysis were carried out based on the plane-wave theory and the pressure-fluctuation theory, and the influence factors of support spacing, the settlement of the fulcrum foundation, pipe pressure and elbow angle were analyzed. The main conclusions are as follows: (1) the unbalanced excited force caused by pressure pulsation greatly affects the stress of the exhaust pipe and compressor outlet pipe, and has less influence on the stress of the suction p... [more]

The demand for heating in cold regions drives up carbon emissions every year. In order to achieve China’s carbon neutrality target by 2060, CO2 emissions in the cold regions must be reduced. In this paper, using Design Builder software, a simulation model of residential buildings in severe cold regions was created, and the most appropriate parameter design scheme for carbon emission reduction of residential buildings in severe cold regions was derived by simulating the experimental data of the original parameter design scheme and the changed parameter design scheme, as well as the calculation of carbon dioxide emission reduction rate. In order to make the comparison of the results easier, no change was made in the selection of the changed scheme for the external insulation material, foamed polystyrene panels. The results show that the most suitable parameter scheme for houses in severe cold regions is 85 mm thick foamed polystyrene panels for exterior walls, 200 mm thick foamed polysty... [more]

The development of many intelligent technologies, such as artificial intelligence and the Internet of Things, has brought new opportunities for water industry intelligence. Based on intelligent pressure regulation technology, this paper built an intelligent management platform, designed an intelligent pressure-regulating device, and combined both to form an intelligent pressure-regulating vehicle (IPRV). The IPRV has the functions of developing a pressure-regulating scheme, equipment selection, pressure reduction potential analysis, etc. It can bring convenience to the field test of the water supply network. In the field test, an intelligent pressure-regulating device was used to obtain the network data in the pilot site called S-cell. After utilizing the intelligent management platform to analyze the measured data, the water usage pattern and pressure reduction potential of the S-cell were obtained, and an optimal pressure-regulating strategy was formulated. The water pressure at the... [more]

The Polish economy is facing a huge challenge regarding the future of energy in Poland. The current energy system is very inefficient, it consumes huge resources that, like countries with high energy efficiency, could be allocated to the development of low-carbon and renewable energy networks. At the moment, the Polish energy sector, related to the coal monoculture, lacks electricity and the entire transmission system is obsolete. The solution may be distributed energy, which can ultimately satisfy energy supplies in less urbanized areas and in rural areas, while guaranteeing the sustainable development of these areas. In order to take up the challenge of better understanding and explaining such a complex reality, it was decided that the research framework of this article will be distributed energy in the region. The aim of the article is to ensure energy security in the conditions of innovative, ecological and open to competition regional energy using local energy resources. Currently... [more]

Phasor measurement units (PMUs) are a key part of electrical power systems, providing the dynamic monitoring and control of electrical units and impacting overall operation and synchronization of a network if not properly designed. This paper investigates the use of a phase-locked loop (PLL)-based algorithm for PMUs (to accurately find the magnitude, phase, and frequency) in a three-phase system. Various PLLs are reported in the literature, ranging from the very basic to advanced, capable of dealing with normal and abnormal grid behavior and mainly used for the control of grid-connected converters. In this paper, a number of PLLs were utilized to perform PMU functions, and a benchmarking study has been investigated to analyze the developed PLL-driven PMUs under various grid conditions (such as unbalanced faults, harmonics, and frequency variations). The simulation and experimental results were provided to support the performance capabilities and suggested limitations. In addition, the... [more]

In order to manage electric vehicles (EVs) connected to charging grids, this paper presents an orderly charging approach based on the EVs’ optimal time-of-use pricing (OTOUP) demand response. Firstly, the Monte Carlo approach is employed to anticipate charging power by developing a probability distribution model of the charging behavior of EVs. Secondly, a scientific classification of the load period is performed using the fuzzy clustering approach. Then, a matrix of demand price elasticity is developed to measure the link between EV charging demand and charging price. Finally, the charging scheme is optimized by an adaptive genetic algorithm from the distribution network and EV user viewpoints. This paper describes how to implement the method presented in this paper in an IEEE-33-bus distribution network. The simulation results reveal that, when compared to fixed price and common time-of-use pricing (CTOUP), the OTOUP charging strategy bears a stronger impact on reducing peak−valley d... [more]

This article provides the results of the first attempt to substantiate the rates of energy consumption and energy savings during the well-drilling process. It is proposed to accept the electrical energy consumption rate as a planned indicator of consumption of resources in the production of a unit of work of a specified quality. For a comprehensive assessment of the efficiency of use of energy resources during production of similar or substitute work, we determined specific energy consumption (designed, planned, actual), which includes direct consumption of all energy types in the production of a unit of work for basic and auxiliary production and operational needs, including from the consumption volume of mentioned resources and energy supply. Classification of consumption rates of electrical energy according to its action period and size scale has been proposed. The composition and amount of energy consumption rates during well-drilling have been described. The technological, expedit... [more]

This paper presents a novel dynamic deep learning architecture integrated with Lyapunov control to address the timing latency and constraints of deep learning. The dynamic component permits the network depth to increase or decrease depending on the system complexity/nonlinearity evaluated through the parameterized complexity method. A correlation study between the parameter tuning effect on the error is also made thus causing a reduction in the deep learning time requirement and computational cost during the network training and retraining process. The control Lyapunov function is utilized as an input cost function to the DNN in order to determine the system stability. A relearning process is triggered to account for the introduction of disturbances or unknown model dynamics, therefore, eliminating the need for an observer-based approach. The introduction of the relearning process also allows the algorithm to be applicable to a wider array of cyber−physical systems (CPS). The intellige... [more]

For the construction of transport infrastructure (including pipeline bridges for oil and gas transportation) in the conditions of the Far North, it is necessary to improve modern regulatory and technological base for using the fiber-reinforcing polymers. It is necessary to conduct searching research to determine the conditions and shapes of application of the fiber-reinforced polymer (FRP) in the load-bearing structures of bridges and pipelines through barriers. One such searching research is the study of the use of a suspension hybrid bridge with a superstructure of FRP. For this purpose, the calculations of finite-element models of pedestrian suspension bridges were performed and their aerodynamic stability was investigated on the section models in a wind tunnel. The novelty of the study consists in the proposed additions to the structure of the bridge, and the permissible geometric of the cross-sections of the superstructure were established for ensuring aerodynamic stability. Final... [more]

Optimal planning of renewable energy generator (REG) units helps to meet future power demand with improved flexibility. Hence, this paper proposes a grid-oriented genetic algorithm (GOGA) based on a hybrid combination of a genetic algorithm (GA) and a solution using analytical power flow equations for optimal sizing and placement of REG units in a power system network. The objective of the GOGA is system loss minimization and flexibility improvement. The objective function expresses the system losses as a function of the power generated by different generators, using the Kron equation. A flexibility index (FI) is proposed to evaluate the improvement in the flexibility, based on the voltage deviations and system losses. A power flow run is performed after placement of REGs at various buses of the test system, and system losses are computed, which are considered as chromosome fitness values. The GOGA searches for the lowest value of the fitness function by changing the location of REG un... [more]

Modelling and simulation is presented for a finned cross-flow heat exchanger with the aim to heat cold air to be fed to air conditioning batteries for marine purposes. The model employed in this paper is finalized to simulate the dynamic behavior of air and water temperatures fed to the air conditioning batteries operating in cold environments, in order to predict possible troubles owing to the change in input parameters, such as unwanted flow rate variations due to system malfunctions. In the investigated model, heat balance equations are presented and discretized by Laplace transform, which has the advantage to easily account for the different structures of heaters used for the purpose of validation. The model was implemented in the Matlab-Simulink environment for its high capacity of dealing with dynamic systems. The results of the model are satisfactory, as the dynamic behavior of the air stream temperature is correctly reproduced, as compared to experimental data, providing a suit... [more]

In this study, a novel smart efficiency tracking (SET) algorithm for GaN-based LLC resonant converter for quick battery charging of light electric vehicles is proposed. Conventional frequency modulation (FM) method, single pulse width modulation method (S-PWM) and discontinuous operation mode method (DOM) are used to track the converter efficiency which varies for different loading conditions during the battery charging process. First, the charging modes are explained to define the efficiency variation clearly. Then, the theoretical background of GaN-based LLC resonant converter is presented and the details of design study are given. Third, the principles of three different switching control strategies, the modeling study and the simulation results are put forward. Finally, the details of the implementation of three different switching strategies are presented for the validation of the study. Furthermore, the implementation of the design and its impact on battery charging are discussed... [more]

This paper concerns the start-up process of a hydrostatic transmission with a fixed displacement pump, with particular emphasis on dynamic surplus pressure. A numerically controlled transmission using a proportional directional valve was analysed by simulation and experimental verification. The transmission is controlled by the throttle method, and the variable resistance is the throttling gap of the proportional spool valve. A mathematical description of the gear start-up process was obtained using a lumped-parameters model based on ordinary differential equations. The proportional spool valve was described using a modified model, which significantly improved the performance of the model in the closed-loop control process. After assuming the initial conditions and parameterization of the equation coefficients, a simulation of the transition start-up was performed in the MATLAB−Simulink environment. Simulations and experimental studies were carried out for control signals of various sh... [more]

Pakistan is facing an energy crisis and is also severely affected by climate change. Moreover, Pakistan is not doing well as far as health outcome indicators are concerned. The causal nexus among energy, environment, and health outcomes is well-established in literature. Besides, financial development also grabs the attention of health outcome literature as financial development can play a significant role in improving health outcomes. Thus, this study was conducted to test the causal nexus among energy consumption, environmental degradation, financial development, and health outcomes in the case of Pakistan. This study proxies health outcomes with life expectancy and infant mortality. Time series data have been analyzed through different econometric techniques, such as unit root tests, cointegration techniques, causality techniques, and cointegration regressions. Moreover, this study not just discovers the causal direction among variables but also determines the strength of causality... [more]

Failure mode, effects and criticality analysis (FMECA) is a well-known reliability analysis tool for recognizing, evaluating and prioritizing the known or potential failures in system, design, and process. In conventional FMECA, the failure modes are evaluated by using three risk factors, severity (S), occurrence (O) and detectability (D), and their risk priorities are determined by multiplying the crisp values of risk factors to obtain their risk priority numbers (RPNs). However, the conventional RPN has been considerably criticized due to its various shortcomings. Although significant efforts have been made to enhance the performance of traditional FMECA, some drawbacks still exist and need to be addressed in the real application. In this paper, a new FMECA model for risk analysis is proposed by using an integrated approach, which introduces Z-number, Rough number, the Decision-making trial and evaluation laboratory (DEMATEL) method and the VIsekriterijumska optimizacija i KOmpromisn... [more]