The study provides a deeper insight into Slovenian mountaineers’ and excursionists’ habits regarding food safety knowledge, food handling practices, and hygiene on expeditions. The objective of the study is to identify gaps in food safety knowledge and food handling practice at home and during mountaineers’ activities. Data were collected using an anonymous online questionnaire (n = 330) and eight semi-structured interviews. The research participants take most of their food with them when they set off, mountaineers more often than excursionists (p < 0.05, p = 0,000). Few interviewees indicated that it is important to them that food is safe while consuming it. Almost 90% of mountaineers and excursionists believe they can identify food safety by smell and taste. Significantly more mountaineers prioritise food enjoyment over hygiene compared to excursionists (p < 0.05, p = 0.001). Mountaineers also feel that they are more resistant to foodborne diseases and are much less concerned a... [more]

In modern industrial systems, high-dimensional process data provide rich information for process monitoring. To make full use of local information of industrial process, a distributed robust dictionary pair learning (DRDPL) is proposed for refined process monitoring. Firstly, the global system is divided into several sub-blocks based on the reliable prior knowledge of industrial processes, which achieves dimensionality reduction and reduces process complexity. Secondly, a robust dictionary pair learning (RDPL) method is developed to build a local monitoring model for each sub-block. The sparse constraint with l2,1 norm is added to the analytical dictionary, and a low rank constraint is applied to the synthetical dictionary, so as to obtain robust dictionary pairs. Then, Bayesian inference method is introduced to fuse local monitoring information to global anomaly detection, and the block contribution index and variable contribution index are used to realize anomaly isolation. Finally,... [more]

A cold-flow lab-scale cross-flow fluidized bed classifier was simulated using the CFD software Barracuda VR®. The purpose of the study was to identify the most suitable drag model and make the model adjustments that provide the best representation of the flow situation in the classifier when comparing the results with the experimental data. Two particle types were used in the simulations and in the experiments: zirconia (median diameter 69 µm, skeletal density 3830 kg/m3) and steel (290 µm, 7790 kg/m3). Ten different cases, with different solids loading values, were investigated: three with pure zirconia particles, three with pure steel particles, and four with a mixture of zirconia (28%) and steel (72%). Several different drag models were tried out in the simulations. However, none of the available models were able to predict the classification efficiency observed in experiments with their default settings. Although most of the drag models correctly predicted the inversely proportiona... [more]

Coal spontaneous combustion is one of the most severe and constant hazards in the coal industry. Understanding the mechanisms is the basis for effective hazard control in the coal-producing process. This paper investigated two types of oxidized coal samples from the re-mining faces of an underground coal mine. Proximate analysis, elemental analysis, surface analysis, temperature-programmed experiments, and differential scanning calorimetry analysis were conducted to study the spontaneous combustion characteristics. Various reaction mechanism functions were adopted to calculate the kinetic parameters, and multiple linear regression was performed to simulate the reaction behavior. The results show that the thermal decomposition of the oxidized coal followed a two-stage reaction model. The first stage reaction occupied smaller apparent activation energy and promoted the second stage reaction, dominating the heat production. Therefore, significant prevention measures for coal spontaneous c... [more]

The review assesses the Hoshin Kanri process from the point of view of theory and practice implementations in different organizations. There are several adaptations of Hoshin Kanri and a wide range of tools used in each organization. This review aims to determine which and how companies have implemented the afore-mentioned methodology into their strategic management. The PRISMA statement was the framework for the present research. The structure for this study was obtained through a review of articles from two of the most important databases (Scopus and Web of Science). The review focuses on three parts: the theoretical basis of the methodology, a bibliometric overview of the selected articles, and practical insight into the implementation of Hoshin Kanri within the case-study organizations. Since the study’s purpose is to determine not only the companies where Hoshin Kanri was implemented but also the reasons and results of those implementations, therefore, 26 journal articles covering... [more]

Powder coatings represent an environmentally friendly VOC-free alternative to widely used solvent-borne zinc-rich coatings, with economic and ecological benefits. In particular, powder coatings have several advantageous properties, such as chemical resistance and mechanical strength. However, the performance and characteristics of polyester-based zinc-containing powder coatings remain unknown. In this study, the corrosion performance of polyester powder coatings containing up to 80% zinc is compared. Electrochemical and salt-spray testing results indicate that coatings formulated with 80% zinc demonstrate superior anti-corrosive properties than coatings with lower zinc dosages. Two distinct behavioral phases of the coating with 80% zinc were observed by measurements of open circuit potential (OCP) and polarization resistance (Rp) during immersion tests—a phase indicative of a barrier effect and a phase consistent with galvanic protection. The evolution of the coating was further charac... [more]

In this paper, an embedded multichannel capillary porous system (EM-CPS) was designed and fabricated with 304 stainless steel using the laser ablation method. The EM-CPS revealed its excellent ability to wick liquid lithium to its surface effectively. The interaction between Li-prefilled EM-CPS and plasma was studied, and the results showed that the surface temperature decreased by ~140 °C compared with the results of the experiment of EM-CPS without lithium filling. Additionally, EM-CPS displayed a better heat transfer performance and stronger radiation loss of the vapor cloud than the traditional woven tungsten-based meshes. In addition, the drift of the lithium vapor cloud center was found during plasma irradiation and led to a decrease in the intensity of the Li 670.78 nm emission line detected by the spectrometer at the observation point. When the thermal load deposited on the sample surface is reinforced by increasing the magnetic field, the rise in surface temperature is restrai... [more]

The direct activation of diluted CO2 in argon was studied in a co-axial dielectric barrier discharge (DBD) reactor powered by photovoltaic energy. The influence of the initial CO2 and argon concentration on the CO2 decomposition to form CO was investigated using a copper-based catalyst in the discharge zone. It was observed that the CO2 conversion was higher at lower CO2 concentrations. The presence of the diluent gas (argon) was also studied and it was observed how it has a high influence on the decomposition of CO2, improving the conversion at high argon concentrations. At the highest observed energy efficiency (1.7%), the CO2 conversion obtained was 40.2%. It was observed that a way to enhance the sustainability of the process was to use photovoltaic energy. Taking into account a life cycle assessment approach (LCA), it was estimated that within the best-case scenario, it would be feasible to counterbalance 97% of the CO2 emissions related to the process.

Improving the performance of flame holders has been a key focus of research on ramjet combustors. The plasma actuator has the potential to improve the ignition performance by manipulating the flow field of the flame holder. In this study, a plasma-actuated flame holder was designed. The aim of this study is to improve the performance of ramjet combustor by applying plasma discharge to the flame holder. The aerodynamic effects and ignition performance of the flame holder were investigated. The results demonstrated that the induced jet direction of the surface arc discharge was perpendicular to the actuator. The induced jet dissipated faster at lower pressures. The aerodynamic actuation intensity and jet area increased with the number of channels of surface arc discharges. Increasing discharge frequencies can increase the discharge times and jet height. The aerodynamic effects under a microsecond pulse duration were better than those under a nanosecond pulse duration. Actuators installed... [more]

From a thermodynamic perspective, the present study has been performed to investigate the effect of SiO2 level in agglomerated fluxes on the element transfer behavior of essential elements, by applying CaF2-Na2O-SiO2 agglomerated fluxes with varying SiO2 contents. Element transfer behavior is quantified by the Δ value. The impact of SiO2 and heat input upon element transfer behavior is interpreted. Additionally, a possible thermodynamic approach to predict high basicity flux O potential and weld metal composition is proposed and evaluated. It is revealed that the consideration of the gas-slag-metal equilibrium is able to place constraints on the transfer behaviors (of O, Si, and Mn) and formation of gases. In submerged arc welding metallurgy, the empirically determined basicity index models proposed by Tuliani have been applied for more than 50 years to predict flux O potential and weld metal oxygen content. However, it is well known by welding practitioners that the flux basicity inde... [more]

The MDAO framework has become an essential part of almost all fields, apart from mechanical, transportation, and aerospace industries, for efficient energy conversion or otherwise. It enables rapid iterative interaction among several engineering disciplines at various fidelities using automation tools for design improvement. An advanced framework from low to high fidelity is developed for ducted and unducted turbomachinery blade designs. The parametric blade geometry tool is a key feature which converts low-fidelity results into 3D blade shapes and can readily be used in high-fidelity multidisciplinary simulations as part of an optimization cycle. The geometry generator and physics solvers are connected to DAKOTA, an open-source optimizer with parallel computation capability. The entire cycle is automated and new design iterations are generated with input parameter variations controlled by DAKOTA. Single- and multi-objective genetic algorithm and gradient method-based optimization case... [more]

This study aims to address the issues of volatile energy access to the active distribution network (ADN), which are the difficulty of frequency regulation, the increased voltage deviation of the ADN, the decrease in operational security and stability, etc. In this study, a two-stage majorization configuration model is established to identify and understand how volatility energy affects a hybrid energy storage system (HESS). The ADN and HESS with lead-acid batteries and supercapacitors (SC) are examined using day forecast data for wind, solar, and load. In this planning stage, the integrated cost, network loss, and node voltage deviation are considered as optimal objectives in a multi-objective optimization model, while the revised multi-objective optimization particle swarm approach is used to solve the initial value of capacity configuration. In the operation stage, optimizing objectives like wind output power fluctuations, the frequency deviation of HESS is used to solve the modified... [more]

Due to the continual fusion reaction, the sun generates tremendous energy. This solar energy is freely available and can be extracted by installing a large-scale solar power plant. Therefore, such PV solar plants are key contributors to cutting the energy deficit in remote areas. This study focused on predicting a 10-year performance analysis of a large-scale solar power plant by using 1 year of real-time data from the Quaid-e-Azam Solar Park (QASP) situated in Bahawalpur, Pakistan. For the purpose of prediction, the ARIMA model was developed using Python, which is one of the best tools in machine learning. Since ARIMA is a statistical technique for prediction, by using the developed model through Python, we predicted the values of the performance ratio (PR), production amount (MWh), and plan of array (POA) of the solar plant for the next 10 years using 1 year of real-time data. This machine learning prediction technique is very effective and efficient, compared with other traditional... [more]

Although constructing a dam can bring significant economic and social benefits to a region, it can be catastrophic for the population living downstream when it breaks. Given the dynamic and nonlinear characteristics of dam deformation, the traditional dam prediction model has been unable to meet the actual engineering demands. Consequently, this paper advocates for a novel method to solve this issue. The proposed method is based on the optimization of improved chicken swarm (ICSO) and support vector machine (SVM). To begin with, the mean square error is used as the objective function, and then, we apply the improved chicken swarm algorithm to iterate continuously, and finally, the optimal SVM parameters are obtained. Through the modeling and simulation experiments of a nonlinear system, the validity of the improved chicken swarm algorithm to optimize an SVM model has been verified. Based on the horizontal displacement monitoring data of FengMan Dam, this paper analyzed the influencing... [more]

The hydrodynamic characteristics of a rod-shaped squirmer swimming near a wall were studied numerically using the immersed boundary-lattice Boltzmann method in the swimming Reynolds number range of 0.1 ≤ Res ≤ 2.0, where the number of assembled squirmers was 2 ≤ i ≤ 4 and the distance between two adjacent assembled squirmers was 0.75 d ≤ s ≤ 1.5 d (d is the diameter of a single squirmer). The effect of Res, i and s on the swimming mode of the squirmer was explored. The results showed that there are four swimming modes after the first collision between the rod-shaped squirmer and the wall. There are also four swimming modes when Res changes from 0.1 to 2.0. Puller, pusher and neutral squirmers showed different swimming modes when i changed, and the effect degree of the flow at the previous moment on the squirmer’s motion was different for different values of i. The change in s only affected the trajectory of the squirmer without changing its motion mode. Puller, pusher and neutral squir... [more]

The paper studies a new distributed control method to solve the economic dispatch problem (EDP) under directed topology based on consensus protocol. Electrical equipment is closely related to frequency, and the frequency of each generator varies independently during operation. Therefore, it hinders the realization of economic dispatch. To solve the problem, we combine a frequency regulator with a consensus protocol, which eliminates the effect of frequency variation on the designed consensus algorithm. Meanwhile, considering the problem of excessive communication cost and low computational efficiency in large-scale power systems, an event-triggered mechanism is introduced into the designed algorithm. Furthermore, in order to overcome the unexpected loss of communication links, the time-varying topology mechanism is employed to develop the distributed economic dispatch (DED) algorithm to improve the robustness. Then, the stability of the above algorithm is proved by graph theory and con... [more]

Carbon Capture and Storage (CCS) technology has attracted increasing attention as global climate change accelerates. Carbon dioxide removal processes under development include pressure swing adsorption (PSA) and chemical absorption using amine solvents. In this paper, an ammonia solvent, which is relatively inexpensive and has good material properties, was used instead of amines in the carbon dioxide removal process simulation as a chemical absorption method. This simulation used the eNRTL thermodynamics model which has the advantage of predicting ions in the liquid phase in Aspen Plus. A case study (Case Study 1) was conducted to verify the validity of the thermodynamic model. The purpose of this research was to find the operating conditions to eliminate more than 90% of the carbon dioxide contained in the flue gas from coal-fired power stations, and to lower heat duty and operating cost conditions. A second case study (Case Study 2) was conducted to find the operating conditions by c... [more]

Unmanned aerial vehicle edge networks (UENs) can reduce the cache load of the core network and improve system performance to provide users with efficient content services. However, the time-varying characteristics of content popularity in UENs lead to a low accuracy of popularity prediction, and the capacity limitations of wireless channel conditions lead to a lower cache hit rate than the rates of traditional fiber-optic-based cache strategies. Therefore, this paper proposes the discrete artificial bee colony cache strategy of UENs (DABCCSU). First, the information−dynamics−dissemination model of UENs (IDDMU) is established to deduce the coupling relationship between the channel capacity and the service probability in IDDMU. The influence of the service probability change on the content dissemination process is discussed, and the content popularity in UENs is predicted by the state iteration matrix. Then, the discrete artificial bee colony cache (DABCC) optimization algorithm is propo... [more]

In this paper, a manufacturing process for a single-server permutation Flow Shop Scheduling Problem with sequence dependant, disjoint setups and makespan minimization is considered. The full problem is divided into two levels, and the lower level, aimed at finding an optimal order of setups for a given fixed order of jobs, is tackled. The mathematical model of the problem is presented along with a solution representation. Several problem properties pertaining to the problem solution space are formulated. The connection between the number of feasible solutions and the Catalan numbers is demonstrated and a Dynamic Programming-based algorithm for counting feasible solution is proposed. An elimination property is proved, which allows one to disregard up 99.99% of the solution space for instances with 10 jobs and 4 machines. A refinement procedure allowing us to improve the solution in the time required to evaluate it is shown. To illustrate how the properties can be used, two solving metho... [more]

This article aims to review, analyze, and classify the published research applications of the Data Envelopment Analysis (DEA) window analysis technique. The number of filtered articles included in the study is 109, retrieved from 79 journals in the web of science (WoS) database during the period 1996−2019. The papers are classified into 15 application areas: energy and environment, transportation, banking, tourism, manufacturing, healthcare, power, agriculture, education, finance, petroleum, sport, communication, water, and miscellaneous. Moreover, we present descriptive statistics related to the growth of publications over time, the journals publishing the articles, keyword terms used, length of articles, and authorship analysis (including institutional and country affiliations). To the best of the authors knowledge, this is the first survey reviewing the literature of the DEA window analysis applications in the 15 areas mentioned in the paper.

In view of the problems associated with the poor stability of coal walls, coal slide and leakage of top-coal at the tunnel excavation working face under a soft and extra-thick coal roof, the surrounding rock at the tunnel excavation working face must be strengthened. The theoretical analysis of rock pressure, numerical simulation and other methods were comprehensively used to study the coal-wall-slicing mechanism. Given the characteristics of a soft and extra-thick coal roof, the combined supporting technology of “coal wall water injection + metal roof frame” is proposed. The findings show that in the process of roadway excavation, the coal−rock junctions of the wall and the middle part of the roof are weak areas that are prone to spalling and therefore need to be strengthened. Laboratory tests determined the moisture content of the coal body during tunneling to provide data for the parameter design of coal wall water injection. Safe and efficient excavation of the roadway was ensured... [more]

The marine ecosystem is one of the richest sources of biologically active compounds, such as enzymes, among which seaweed is one of the most diverse marine species and has a rich diversity of bacteria that produce different enzymes. Among these, the bacteria-derived xylanase enzyme has many applications in the fruit juice, paper, and baking industries; so, to consider the economic value of the xylanase enzyme and the isolation and identification of xylanase-producing bacteria is of particular importance. In this study, specimens of the alga Ulva flexuosa species were collected from the coasts of Bandar Abbas and Qeshm Island. The bacteria coexisting with the algae were isolated using a nutrient agar medium. The bacteria producing the xylanase enzyme were then screened by a specific solid culture medium containing xylan, and the activity of the xylanase enzyme isolated from the bacteria was measured using a xylan substrate. The bacteria with the highest enzymatic activity were selected... [more]

Water pollution is a severe health concern. Several studies have recently demonstrated the efficacy of various approaches for treating wastewater from anthropogenic activities. Wastewater treatment is an artificial procedure that removes contaminants and impurities from wastewater or sewage before discharging the effluent back into the environment. It can also be recycled by being further treated or polished to provide safe quality water for use, such as potable water. Municipal and industrial wastewater treatment systems are designed to create effluent discharged to the surrounding environments and must comply with various authorities’ environmental discharge quality rules. An effective, low-cost, environmentally friendly, and long-term wastewater treatment system is critical to protecting our unique and finite water supplies. Moreover, this paper discusses water pollution classification and the three traditional treatment methods of precipitation/encapsulation, adsorption, and membra... [more]

Under the dual−carbon goal, the research on energy conservation and emission reduction of new energy vehicles has once again become a current hotspot, and plug−in hybrid electric vehicles (PHEVs) are the first to bear the brunt. In order to improve the fuel economy of PHEV, an adaptive energy management strategy is designed on the basis of the intelligent prediction of driving cycles. Firstly, according to the vehicle dynamics model, the optimal control objective function of PHEV is established, and the relationship between vehicle fuel consumption and driving cycle is analyzed. Secondly, the initial weights and threshold of the backpropagation (BP) neural network are optimized using the particle swarm optimization (PSO) algorithm, and a PSO−BP neural network vehicle velocity prediction controller is established. Thirdly, combined with the approximate equivalent consumption minimization strategy (ECMS) algorithm to calculate the optimal initial equivalent factor in the prediction time... [more]

The development of drug resistance to presently available synthetic medicines leads us to investigate naturally produced small bioactive molecules to treat drug-resistant diseases, such as cancer and other diseases [...]