bluuebunny/crossref_metadata_2025 huggingface dataset:
A Tunable Microstrip Bandpass Filter with Two Concurrently Tuned Transmission Zeros
Authors: Magnuski Mirosław , Wójcik Dariusz , Surma Maciej , Noga Artur
Published: March 2022

In this paper, an electrically small tunable microstrip bandpass filter with two concurrently tuned transmission zeros (TZs) is presented. The filter consists of two coupled resonators and varactors as tuning elements. An application of a multipath coupling network results in TZs on both sides of the passband. The filter controlled by a single voltage has a wide tuning range from 370 MHz to 800 MHz and a low insertion loss ranging from 1.9 dB to 3.4 dB. To achieve high attenuation in the stopband, two sections of the designed filter were cascaded. Both one-section and two-section filters were validated by measurements. The obtained results are in a very good agreement with simulations.
‘Should I Turn on My Video Camera?’ The Students’ Perceptions of the use of Video Cameras in Synchronous Distant Learning
Authors: Sederevičiūtė-Pačiauskienė Živilė , Valantinaitė Ilona , Asakavičiūtė Vaida
Published: March 2022

One of the challenges teachers and students face in online synchronous learning is not turning on their video cameras. The reasons are multitasking, being concerned about the background, psychological barriers, and poor internet connection. In this study, social presence theory (SPT) was employed as the theoretical lens to understand the possible impacts of video cameras in synchronous online learning. Social presence allows individuals to make personal characteristics visible to the community. Students experience greater levels of trust and rapport because of verbal and nonverbal cues that occur when video cameras are turned on in video conferencing. The use of video cameras in synchronous distant learning creates intimacy and immediacy, leading to teacher–learner social presence, which leads to dialog. The phenomenographic study was carried out to analyze the students’ perceptions of the phenomena. The eighty-two first-year undergraduate and doctoral students took part in the study. It showed that students perceive a video camera as a tool for cooperation, as well as for self-discipline and self-control. The students relate the use of video cameras with quality studies, the ability to interact, and to be a part of the process. They feel less inclined to participate when their cameras are off. That leads to the weaker student–teacher relationship, which is achieved with a higher social presence. It is essential to see one other to strengthen students’ motivation, sense of belonging, and community in the courses for first-year students who are still developing learning habits and social networks.
Design and Analysis of Anti-Noise Parameter-Variable Zeroing Neural Network for Dynamic Complex Matrix Inversion and Manipulator Trajectory Tracking
Authors: Zhou Peng , Tan Mingtao , Ji Jianbo , Jin Jie
Published: March 2022

Dynamic complex matrix inversion (DCMI) problems frequently arise in the territories of mathematics and engineering, and various recurrent neural network (RNN) models have been reported to effectively find the solutions of the DCMI problems. However, most of the reported works concentrated on solving DCMI problems in ideal no noise environment, and the inevitable noises in reality are not considered. To enhance the robustness of the existing models, an anti-noise parameter-variable zeroing neural network (ANPVZNN) is proposed by introducing a novel activation function (NAF). Both of mathematical analysis and numerical simulation results demonstrate that the proposed ANPVZNN model possesses fixed-time convergence and robustness for solving DCMI problems. Besides, a successful ANPVZNN-based manipulator trajectory tracking example further verifies its robustness and effectiveness in practical applications.
Hybridizing of Whale and Moth-Flame Optimization Algorithms to Solve Diverse Scales of Optimal Power Flow Problem
Authors: Nadimi-Shahraki Mohammad H. , Fatahi Ali , Zamani Hoda , Mirjalili Seyedali , Oliva Diego
Published: March 2022

The optimal power flow (OPF) is a practical problem in a power system with complex characteristics such as a large number of control parameters and also multi-modal and non-convex objective functions with inequality and nonlinear constraints. Thus, tackling the OPF problem is becoming a major priority for power engineers and researchers. Many metaheuristic algorithms with different search strategies have been developed to solve the OPF problem. Although, the majority of them suffer from stagnation, premature convergence, and local optima trapping during the optimization process, which results in producing low solution qualities, especially for real-world problems. This study is devoted to proposing an effective hybridizing of whale optimization algorithm (WOA) and a modified moth-flame optimization algorithm (MFO) named WMFO to solve the OPF problem. In the proposed WMFO, the WOA and the modified MFO cooperate to effectively discover the promising areas and provide high-quality solutions. A randomized boundary handling is used to return the solutions that have violated the permissible boundaries of search space. Moreover, a greedy selection operator is defined to assess the acceptance criteria of new solutions. Ultimately, the performance of the WMFO is scrutinized on single and multi-objective cases of different OPF problems including standard IEEE 14-bus, IEEE 30-bus, IEEE 39-bus, IEEE 57-bus, and IEEE118-bus test systems. The obtained results corroborate that the proposed algorithm outperforms the contender algorithms for solving the OPF problem.
Methods of Handling the Cup Plant (Silphium perfoliatum L.) for Energy Production
Authors: Witaszek Kamil , Herkowiak Marcin , Pilarska Agnieszka A. , Czekała Wojciech
Published: March 2022

The aim of the study was to determine the possibilities of using cup plants (Silphium perfoliatum L.) to generate energy. The energy balances of the combustion and anaerobic digestion were compared. The research showed that cup plants could be used as a raw material for solid fuel and for anaerobic digestion. An energy balance simulation showed that electricity could be generated through the anaerobic digestion of cup plants. The following amounts could be generated in the anaerobic digestion process: 1069 kWhe from 1 Mg of the raw material fragmented with an impact mill, 738.8 kWhe from 1 Mg of the raw material extruded at a temperature of 150 °C, and as much as 850.1 kWhe from 1 Mg of the raw material extruded at 175 °C. The energy balance of the combustion of biofuel in the form of cup plant pellets showed that 858.28 kWht could be generated from 1 Mg of the raw material. The combustion of solid biofuel generated a relatively low amount of heat in comparison with the expected amount of heat from a biogas-powered cogeneration system due to the high energy consumption of the processes of drying and agglomeration of the raw material for the production of pellets.
A Resistor-Network Model of Dickson Charge Pump Using Steady-State Analysis
Authors: Aloqlah Abdullah S. , Alhawari Mohammad
Published: March 2022

This paper presents a new average behavioral model, named a resistor-network (RN) model, that accurately predicts the electrical characteristics of the Dickson charge pump (DCP) circuit in the slow-switching limit and the fast-switching limit regions based on steady-state analysis. The RN model describes the steady-state behavior of a single-stage DCP using a network of resistors, which can then be cascaded to model N-stage DCP, taking into account the top- and bottom-plate parasitic capacitances. The RN model provides a comprehensive insight into various design parameters of the DCP, including the input/output current, output voltage, load characteristics, losses caused by parasitics, and power efficiency. Simulation results show that the proposed RN model accurately predicts the output voltage and power efficiency of the DCP over a wide range of switching frequencies, from 0.1 Hz to 1 GHz, with an error of less than 2% at the maximum power efficiency. The RN model provides designers with a simple and effective model to design DCP quickly and efficiently for a broad spectrum of applications, including energy harvesting and flash memory applications.
Smart Electric Vehicle Charging in the Era of Internet of Vehicles, Emerging Trends, and Open Issues
Authors: Rimal Bhaskar , Kong Cuiyu , Poudel Bikrant , Wang Yong , Shahi Pratima
Published: March 2022

The Internet of Vehicles (IoV), where people, fleets of electric vehicles (EVs), utility, power grids, distributed renewable energy, and communications and computing infrastructures are connected, has emerged as the next big leap in smart grids and city sectors for a sustainable society. Meanwhile, decentralized and complex grid edge faces many challenges for planning, operation, and management of power systems. Therefore, providing a reliable communications infrastructure is vital. The fourth industrial revolution, that is, a cyber-physical system in conjunction with the Internet of Things (IoT) and coexistence of edge (fog) and cloud computing brings new ways of dealing with such challenges and helps maximize the benefits of power grids. From this perspective, as a use case of IoV, we present a cloud-based EV charging framework to tackle issues of high demand in charging stations during peak hours. A price incentive scheme and another scheme, electricity supply expansion, are presented and compared with the baseline. The results demonstrate that the proposed hierarchical models improve the system performance and the quality of service (QoS) for EV customers. The proposed methods can efficiently assist system operators in managing the system design and grid stability. Further, to shed light on emerging technologies for smart and connected EVs, we elaborate on seven major trends: decentralized energy trading based on blockchain and distributed ledger technology, behavioral science and behavioral economics, artificial and computational intelligence and its applications, digital twins of IoV, software-defined IoVs, and intelligent EV charging with information-centric networking, and parking lot microgrids and EV-based virtual storage. We have also discussed some of the potential research issues in IoV to further study IoV. The integration of communications, modern power system management, EV control management, and computing technologies for IoV are crucial for grid stability and large-scale EV charging networks.
Advances in Power Quality Analysis Techniques for Electrical Machines and Drives: A Review
Authors: Gonzalez-Abreu Artvin-Darien , Osornio-Rios Roque-Alfredo , Jaen-Cuellar Arturo-Yosimar , Delgado-Prieto Miguel , Antonino-Daviu Jose-Alfonso , Karlis Athanasios
Published: March 2022

The electric machines are the elements most used at an industry level, and they represent the major power consumption of the productive processes. Particularly speaking, among all electric machines, the motors and their drives play a key role since they literally allow the motion interchange in the industrial processes; it could be said that they are the medullar column for moving the rest of the mechanical parts. Hence, their proper operation must be guaranteed in order to raise, as much as possible, their efficiency, and, as consequence, bring out the economic benefits. This review presents a general overview of the reported works that address the efficiency topic in motors and drives and in the power quality of the electric grid. This study speaks about the relationship existing between the motors and drives that induces electric disturbances into the grid, affecting its power quality, and also how these power disturbances present in the electrical network adversely affect, in turn, the motors and drives. In addition, the reported techniques that tackle the detection, classification, and mitigations of power quality disturbances are discussed. Additionally, several works are reviewed in order to present the panorama that show the evolution and advances in the techniques and tendencies in both senses: motors and drives affecting the power source quality and the power quality disturbances affecting the efficiency of motors and drives. A discussion of trends in techniques and future work about power quality analysis from the motors and drives efficiency viewpoint is provided. Finally, some prompts are made about alternative methods that could help in overcome the gaps until now detected in the reported approaches referring to the detection, classification and mitigation of power disturbances with views toward the improvement of the efficiency of motors and drives.
Vibration Reduction System with a Linear Motor: Operation Modes, Dynamic Performance, Energy Consumption
Authors: Orkisz Paweł , Sapiński Bogdan
Published: March 2022

The study aimed to present the features of a 2-DOF vibration reduction system (VRS) equipped with a linear electrodynamic motor in passive, semi-active and active mode. At first, the VRS model was formulated. Then, simulation tests of the VRS were conducted to distinguish its most advantageous features in each mode and to analyze dynamic performance and energy consumption. Next, the VRS was experimentally tested to evaluate its effectiveness in each mode for the assumed excitations and to compare tests results against simulation data. In active mode, a sliding mode algorithm was employed for motor control, while in semi-active mode, the equivalent damping coefficient analysis was used.
Combustion Performance and Low NOx Emissions of a Dimethyl Ether Compression-Ignition Engine at High Injection Pressure and High Exhaust Gas Recirculation Rate
Authors: Youn Inmo , Jeon Joonho
Published: March 2022

Dimethyl ether (DME) is a promising alternative to diesel for compression-ignition (CI) engines used in various industrial applications. However, the high nitrogen oxide (NOx) emissions of DME combustion have restricted its use. The primary cause of high NOx emissions is a high combustion temperature. In this study, a high exhaust gas recirculation (EGR) rate was used when testing a common-rail direct injection CI engine suitable (with minor modifications) for a passenger car. A modified fuel supply system created high injection pressure during evaluation of combustion performance. The physical and chemical properties of DME were the principal determinants of the ignition delay, combustion speed, and heat release rate. Although a high injection pressure accelerated formation of the fuel-air mixture and the combustion speed, combustion performance deteriorated with increased NOx emissions. An increased EGR rate affected combustion and the NOx concentration. A high EGR rate effectively reduced NOx formation and emission under low-temperature combustion conditions. Also, the good DME combustion characteristics were maintained when the EGR rate was high, unlike for an ultra-low sulfur diesel engine.
Traditional Town Houses in Kyoto, Japan: Present and Future
Authors: Iba Chiemi , Hokoi Shuichi
Published: March 2022

Climate change is an important issue that affects energy consumption, causes health problems, such as heat stroke, and requires urgent countermeasures. Serious health problems, including cardiac arrest, often occur in winter in traditional residences in Japan. Cooling-heating energy is required to maintain a healthy thermal environment. Although energy efficiency standards for buildings have been introduced worldwide to reduce energy consumption and various passive energy-saving methods are being investigated, traditional residences still face difficulties in conducting renovations because of various restrictions, such as the conservation of historical or aesthetic values. In this study, these issues and their appropriate countermeasures were investigated for a traditional townhouse in Kyoto, Japan, “Kyo-machiya” (including its new form “Heisei-no-Kyo-machiya”). The potential of reducing heating and cooling loads was examined by conducting numerical analysis considering residents’ lifestyles. Field surveys of the indoor environment were conducted in both summer and winter. It was revealed that by optimizing the times and positions of opening and closing the windows and indoor partitions, the indoor air flow could be adjusted from both thermal comfort (cooling in summer) and discomfort (cold drafts in winter) perspectives, leading to improving the indoor environment without using energy.
A Review on the Enhancement of Mechanical and Tribological Properties of MCrAlY Coatings Reinforced by Dispersed Micro and Nanoparticles
Authors: Zakeri Ali , Bahmani Elnaz , Ramazani Ali
Published: March 2022

The application of metal-matrix composite coatings for protecting and improving the service life of sliding components has demonstrated to have the potential of meeting the requirements of a diverse range of engineering industries. Recently, a significant body of research has been devoted to studying the mechanical and tribological performance of dispersion-strengthened MCrAlY coatings. These coatings belong to a class of emerging wear-resistant materials, offering improved properties and being considered as promising candidates for the protection of engineering structural materials exposed to tribological damage, especially at elevated temperature regimes. This paper attempts to comprehensively review the different reinforcements used in the processing of MCrAlY-based alloys and how they influence the mechanical and tribological properties of the corresponding coatings. Furthermore, the major fabrication techniques together with their benefits and challenges are also reviewed. Discussion on the failure mechanisms of these coatings as well as the main determining factors are also included. In addition, a comprehensive survey of studies and investigations in recent times are summarized and elaborated to further substantiate the review.
Multi-Agent-Based Coordinated Control of ABS and AFS for Distributed Drive Electric Vehicles
Authors: Zhang Niaona , Wang Jieshu , Li Zonghao , Li Shaosong , Ding Haitao
Published: March 2022

A vehicle with a four-channel anti-lock braking system (ABS) has poor safety and stability when braking on a low-adhesion road or off-road. In view of this situation, this paper proposes a multi-objective optimization coordinated control method for ABS and AFS based on multi-agent model predictive control (MPC). Firstly, the single-wheel control method is adopted to establish the single-wheel equation based on the slip rate and the stability equation of the centroid yaw based on AFS. The four wheels and the centroid are regarded as agents. The mathematical model of distributed drive electric vehicles based on graph theory and the coordinated control of AFS and ABS is established to reduce the dimension of the model. Secondly, on the basis of the multi-agent theory, an integrated coordinated control method for AFS and ABS based on distributed model predictive control (DMPC) is proposed to realize the ideal values of the vehicle’s slip rate, yaw rate, and sideslip angle, and improve the braking safety and handling stability of the vehicle. Then, to solve the problems of high levels of resource consumption, low real-time performance, and complex implementation in the optimization of the DMPC solution, a prediction solution method using a discrete simplified dual neural network (SDNN) is proposed to balance the computational efficiency and system dynamic performance. Finally, a hardware-in-the-loop (HIL) test bench is built to test the effectiveness of the proposed method under the conditions of a low-adhesion road and an off-road.
Metagenomic Analysis of the Long-Term Synergistic Effects of Antibiotics on the Anaerobic Digestion of Cattle Manure
Authors: Wolak Izabela , Czatzkowska Małgorzata , Harnisz Monika , Jastrzębski Jan Paweł , Paukszto Łukasz , Rusanowska Paulina , Felis Ewa , Korzeniewska Ewa
Published: March 2022

The conversion of cattle manure into biogas in anaerobic digestion (AD) processes has been gaining attention in recent years. However, antibiotic consumption continues to increase worldwide, which is why antimicrobial concentrations can be expected to rise in cattle manure and in digestate. This study examined the long-term synergistic effects of antimicrobials on the anaerobic digestion of cattle manure. The prevalence of antibiotic resistance genes (ARGs) and changes in microbial biodiversity under exposure to the tested drugs was investigated using a metagenomic approach. Methane production was analyzed in lab-scale anaerobic bioreactors. Bacteroidetes, Firmicutes, and Actinobacteria were the most abundant bacteria in the samples. The domain Archaea was represented mainly by methanogenic genera Methanothrix and Methanosarcina and the order Methanomassiliicoccales. Exposure to antibiotics inhibited the growth and development of methanogenic microorganisms in the substrate. Antibiotics also influenced the abundance and prevalence of ARGs in samples. Seventeen types of ARGs were identified and classified. Genes encoding resistance to tetracyclines, macrolide–lincosamide–streptogramin antibiotics, and aminoglycosides, as well as multi-drug resistance genes, were most abundant. Antibiotics affected homoacetogenic bacteria and methanogens, and decreased the production of CH4. However, the antibiotic-induced decrease in CH4 production was minimized in the presence of highly drug-resistant microorganisms in AD bioreactors.
Machine Learning-Enhanced Play Fairway Analysis for Uncertainty Characterization and Decision Support in Geothermal Exploration
Authors: Holmes R. Chadwick , Fournier Aimé
Published: March 2022

Geothermal exploration has traditionally relied on geological, geochemical, or geophysical surveys for evidence of adequate enthalpy, fluids, and permeability in the subsurface prior to drilling. The recent adoption of play fairway analysis (PFA), a method used in oil and gas exploration, has progressed to include machine learning (ML) for predicting geothermal drill site favorability. This study introduces a novel approach that extends ML PFA predictions with uncertainty characterization. Four ML algorithms—logistic regression, a decision tree, a gradient-boosted forest, and a neural network—are used to evaluate the subsurface enthalpy resource potential for conventional or EGS prospecting. Normalized Shannon entropy is calculated to assess three spatially variable sources of uncertainty in the analysis: model representation, model parameterization, and feature interpolation. When applied to southwest New Mexico, this approach reveals consistent enthalpy trends embedded in a high-dimensional feature set and detected by multiple algorithms. The uncertainty analysis highlights spatial regions where ML models disagree, highly parameterized models are poorly constrained, and predictions show sensitivity to errors in important features. Rapid insights from this analysis enable exploration teams to optimize allocation decisions of limited financial and human resources during the early stages of a geothermal exploration campaign.
A Closed Form Selected Mapping Algorithm for PAPR Reduction in OFDM Multicarrier Transmission
Authors: Carcangiu Sara , Fanni Alessandra , Montisci Augusto
Published: March 2022

Nowadays, the demand for communication multi-carriers’ channels, where the sub-channels are made mutually independent by using orthogonal frequency division multiplexing (OFDM), is widespread both for wireless and wired communication systems. Even if OFDM is a spectrally efficient modulation scheme, due to the allowed number of subcarriers, high data rate, and good coverage, the transmitted signal can present high peak values in the time domain, due to inverse fast Fourier transform operations. This gives rise to high peak-to-average power ratio (PAPR) with respect to single carrier systems. These peaks can saturate the transmitting amplifiers, modifying the shape of the OFDM symbol and affecting its information content, and they give rise to electromagnetic compatibility issues for the surrounding electric devices. In this paper, a closed form PAPR reduction algorithm is proposed, which belongs to selected mapping (SLM) methods. These methods consist in shifting the phases of the components to minimize the amplitude of the peaks. The determination of the optimal set of phase shifts is a very complex problem; therefore, the SLM approaches proposed in literature all resort to iterative algorithms. Moreover, as this calculation must be performed online, both the computational cost and the effect on the bit rate (BR) cannot be established a priori. The proposed analytic algorithm finds the optimal phase shifts of an approximated formulation of the PAPR. Simulation results outperform unprocessed conventional OFDM transmission by several dBs. Moreover, the complementary cumulative distribution function (CCDF) shows that, in most of the packets, the proposed algorithm reduces the PAPR if compared with randomly selected phase shifts. For example, with a number of shifted phases U=8, the CCFD curves corresponding to the analytical and random methods intersect at a probability value equal to 10−2, which means that in 99% of cases the former method reduces the PAPR more than the latter one. This is also confirmed by the value of the gain, which, at the same number of shifted phases and at the probability value equal to 10−1, changes from 2.09 dB for the analytical to 1.68 dB for the random SLM.
Effect of Ignition Energy and Hydrogen Addition on Laminar Flame Speed, Ignition Delay Time, and Flame Rising Time of Lean Methane/Air Mixtures
Authors: Nguyen Minh Tien , Luong Van Van , Pham Quoc Thai , Phung Minh Tung , Do Phu Nguu
Published: March 2022

A series of experiments were performed to investigate the effect of ignition energy (Eig) and hydrogen addition on the laminar burning velocity (Su0), ignition delay time (tdelay), and flame rising time (trising) of lean methane−air mixtures. The mixtures at three different equivalence ratios (ϕ) of 0.6, 0.7, and 0.8 with varying hydrogen volume fractions from 0 to 50% were centrally ignited in a constant volume combustion chamber by a pair of pin-to-pin electrodes at a spark gap of 2.0 mm. In situ ignition energy (Eig ∼2.4 mJ ÷ 58 mJ) was calculated by integration of the product of current and voltage between positive and negative electrodes. The result revealed that the Su0 value increases non-linearly with increasing hydrogen fraction at three equivalence ratios of 0.6, 0.7, and 0.8, by which the increasing slope of Su0 changes from gradual to drastic when the hydrogen fraction is greater than 20%. tdelay and trising decrease quickly with increasing hydrogen fraction; however, trising drops faster than tdelay at ϕ = 0.6 and 0.7, and the reverse is true at ϕ = 0.8. Furthermore, tdelay transition is observed when Eig > Eig,critical, by which tdelay drastically drops in the pre-transition and gradually decreases in the post-transition. These results may be relevant to spark ignition engines operated under lean-burn conditions.
Entrained Flow Plasma Gasification of Sewage Sludge–Proof-of-Concept and Fate of Inorganics
Authors: Vishwajeet  , Pawlak-Kruczek Halina , Baranowski Marcin , Czerep Michał , Chorążyczewski Artur , Krochmalny Krystian , Ostrycharczyk Michał , Ziółkowski Paweł , Madejski Paweł , Mączka Tadeusz , Arora Amit , Hardy Tomasz , Niedzwiecki Lukasz , Badur Janusz , Mikielewicz Dariusz
Published: March 2022

Sewage sludge is a residue of wastewater processing that is biologically active and consists of water, organic matter, including dead and living pathogens, polycyclic aromatic hydrocarbons, and heavy metals, as well as organic and inorganic pollutants. Landfilling is on the decline, giving way to more environmentally friendly utilisation routes. This paper presents the results of a two-stage gasification–vitrification system, using a prototype-entrained flow plasma-assisted gasification reactor along with ex situ plasma vitrification. The results show that the use of plasma has a considerable influence on the quality of gas, with a higher heating value of dry gas exceeding 7.5 MJ/mN3, excluding nitrogen dilution. However, dilution from plasma gases becomes the main problem, giving a lower heating value of dry gas with the highest value being 5.36 MJ/mN3 when dilution by nitrogen from plasma torches is taken into account. An analysis of the residues showed a very low leaching inclination of ex-situ vitrified residues. This suggests that such a system could be used to avoid the problem of landfilling significant amounts of ash from sewage sludge incineration by turning inorganic residues into a by-product that has potential use as a construction aggregate.
Effective Volt/var Control for Low Voltage Grids with Bulk Loads
Authors: Schultis Daniel-Leon
Published: March 2022

This paper investigates the voltage and reactive power control problem in low voltage grids with connected prosumers and bulk loads. The X(U) local control, which maintains the voltage at the feeders’ ends within a predefined band, and its combination with Q-Autarkic customer plants are the most effective and reliable strategies in grids with high prosumer share. However, these strategies may need adaptations to guarantee voltage limit compliance when bulk loads, such as electric vehicle parking garages and community-owned photovoltaic systems, are connected to the low voltage feeders. This paper extends the X(U) local control concept to involve bulk loads in Volt/var control and investigates the resulting load flows in different real low voltage grids. The results show that the extended control arrangement reliably removes all voltage limit violations by deteriorating the effectiveness of the original X(U) local control arrangement: reactive power flows and equipment loading within the low voltage grids are increased.
Relative Assessment of Biochemical Constituents and Antioxidant Potential of Fermented Wheat Grains Using Bacillus subtilis KCTC 13241
Authors: Ilyas Muhammad Zahaib , Lee Ju Kyong , Ali Muhammad Waqas , Tariq Sana , Nadeem Muhammad
Published: March 2022

High antioxidant levels in food are gradually becoming popular because of enhanced risk of oxidative stress in humans. Bread wheat is rich in vital antioxidants, but a major portion of its bioactive compounds are not available to humans. This study was conducted with the aim to fulfill the antioxidants and nutrients gap between the available and potential levels of wheat grains through fermentation by Bacillus subtilis KCTC 13241. In this experiment, the whole wheat grains were used by keeping in consideration the importance of minerals and to measure an increase in their availability after fermentation. The antioxidants and nutritional potential of different wheat varieties was determined by DPPH (2,2-diphenyl-1-picryl- hydrazyl) and ABTS (3-ethyl-benzothiazo- line-6-sulfonic acid) radical scavenging assays as well as by the concentration of amino acids, flavonoids, minerals, carbohydrates and phenolic compounds. Different wheat varieties were showed different free radical scavenging potential after fermentation, which was significantly higher with respect to their corresponding unfermented wheat varieties. The highest nutritional and free radical scavenging potential was found in a fermented wheat variety, named Namhae, and this combination is highly useful for cereal-based food industries.
Bioethanol Production from Spent Sugar Beet Pulp—Process Modeling and Cost Analysis
Authors: Vučurović Damjan , Bajić Bojana , Vučurović Vesna , Jevtić-Mučibabić Rada , Dodić Siniša
Published: March 2022

Global economic development has led to the widespread use of fossil fuels, and their extensive use has resulted in increased environmental pollution. As a result, significantly more attention is being paid to environmental issues and alternative renewable energy sources. Bioethanol production from agro-industrial byproducts, residues, and wastes is one example of sustainable energy production. This research aims to develop a process and cost model of bioethanol production from spent sugar beet pulp. The model was developed using SuperPro Designer® v.11 (Intelligen Inc., Scotch Plains, NJ, USA) software, and determines the capital and production costs for a bioethanol-producing plant processing about 17,000 tons of spent sugar beet pulp per year. In addition, the developed model predicts the process and economic indicators of the analyzed biotechnological process, determines the share of major components in bioethanol production costs, and compares different model scenarios for process co-products. Based on the obtained results, the proposed model is viable and represents a base case for further bioprocess development.
Bio-Based Processes for Material and Energy Production from Waste Streams under Acidic Conditions
Authors: Cetecioglu Zeynep , Atasoy Merve , Cenian Adam , Sołowski Gaweł , Trček Janja , Ugurlu Aysenur , Sedlakova-Kadukova Jana
Published: March 2022

The revolutionary transformation from petrol-based production to bio-based production is becoming urgent in line with the rapid industrialization, depleting resources, and deterioration of the ecosystem. Bio-based production from waste-streams is offering a sustainable and environmentally friendly solution. It offers several advantages, such as a longer operation period, less competition for microorganisms, higher efficiency, and finally, lower process costs. In the current study, several bio-based products (organic acids, biomethane, biohydrogen, and metal leachates) produced under acidic conditions are reviewed regarding their microbial pathways, processes, and operational conditions. Furthermore, the limitations both in the production process and in the scale-up are evaluated with future recommendations.
Biosynthesis of Guanidinoacetate by Bacillus subtilis Whole-Cell Catalysis
Authors: Yan Kun , Tian Rongzhen , Zhang Linpei , Lv Xueqin , Liu Long , Liu Yanfeng
Published: March 2022

Guanidinoacetate (GAA) is a naturally occurring amino acid derivative and the direct precursor of creatine, which is widely used in feed additives and the pharmaceutical industry. The current industrial synthesis of GAA is based on chemical methods, which limits the application of GAA. Here, a biological approach is developed for food safety GAA production via whole-cell biocatalysis by the generally regarded as safe (GRAS) bacterium Bacillus subtilis. First, we introduced a heterologous arginine: glycine amidinotransferase (AgaT) from Amycolatopsis kentuckyensis into B. subtilis and optimized its expression level using strategies including: promoter optimization, ribosome binding site (RBS) and N-terminal coding sequence (NCS) screening. In order to alleviate the waste of arginine and the inhibition of AgaT by ornithine, we optimized the natural ornithine cycle in B. subtilis. At the same time, the first gene in the glycine degradation pathway was knocked out. After optimization using these strategies, the titer of GAA was 4.26 g/L with a productivity of 0.21 g/L/h in 20 h, which provides a new method for the biosynthesis of GAA.
Acoustic Characterization and Modeling of Silicone-Bonded Cocoa Crop Waste Using a Model Based on the Gaussian Support Vector Machine
Authors: Puyana-Romero Virginia , Iannace Gino , Cajas-Camacho Lilian Gisselle , Garzón-Pico Christiam , Ciaburro Giuseppe
Published: March 2022

The sustainable management of waste from agricultural crops represents an urgent challenge. One possible solution considers waste as possible secondary raw materials for specific uses. Among these, the use of agricultural waste as a product for the assembly of panels for the sound absorption of living environments represents a particularly suitable solution. In this study, the acoustic properties of the cocoa pod husk were evaluated, using silicone as a binder. Different proportions of materials and thicknesses were evaluated. A Support Vector Machine (SVM)-based model with a Gaussian kernel was then used to predict the acoustic performance of composite materials. The results obtained suggest the adoption of this material for the acoustic correction of living environments and this methodology for the prediction of the acoustic behavior of materials.
Numerical Simulation Analysis of Fire Hazard from Leakage and Diffusion of Vinyl Chloride in Different Atmospheric Environments
Authors: Liu Yuchuan , Wang Jian
Published: March 2022

In this paper, using the numerical simulation analysis software MATLAB and Fire Dynamics Simulation (FDS), the corresponding gas leakage diffusion model and turbulence leakage diffusion module were used to study the diffusion law and fire hazard of vinyl chloride monomer after leakage in different atmospheric environments. The concentration distribution results for vinyl chloride diffusion obtained by numerical simulation were compared and analyzed. The fire hazard area of leakage diffusion is defined by the hot fire concentration of vinyl chloride gas, and the influence of the gas-phase oxidation reaction of vinyl chloride on leakage diffusion is also discussed. The conclusion shows that as the atmospheric environment stabilizes, the peak concentration of vinyl chloride leakage and the diffusion area decrease correspondingly, the fire risk area gradually shrinks, the fire risk decreases, the affected area gradually expands, and the toxicity risk increases. When it is not in a stable state, the formaldehyde derived from the gas-phase oxidation reaction aggregates together with vinyl chloride to form a mixed gas cloud. Although the scope of influence is reduced, the concentration of harmful gases in the area is higher, and the fire risk of the mixed gas is increased.
Numerical Study of Particle Margination in a Square Channel Flow with Red Blood Cells
Authors: Oh Dongig , Ii Satoshi , Takagi Shu
Published: March 2022

Red blood cells flow near the axis in a small vessel, known as axial accumulation. This causes a region called the cell-free layer, which does not contain red blood cells near the wall. Then, small particles such as platelets come out to the cell-free layer. This phenomenon is called platelet margination. In this study, related to this phenomenon, direct numerical simulations were conducted using the immersed boundary method. The effects of the shear rate, channel size, and hematocrit value were investigated on the pressure-driven flow in a straight tube with a square cross-section. The simulation results indicated that the margination rate, which is the ratio of the distance traveled in the flow direction to the margination distance in the wall direction, is independent of the shear rate. The effect of the channel size on platelet margination was found to be well scaled by introducing a dimensionless parameter, which included the shear rate and effective area of the particle movement. It was also found that the margination rate varied nonlinearly with the tube hematocrit. This was due to the volume exclusion effect of red blood cells, which facilitated or hindered the motion of particles depending on the hematocrit. The relationship between the stable position of the particles near the corner and the width of the cell-free layer was also found. Furthermore, velocity fluctuations normalized by wall shear rate in a cross-section collapsed to one curve in the presented simulations. This indicates that the lateral force acting on the particles increases linearly with the shear rate.
Maternal Protein Restriction and Post-Weaning High-Fat Feeding Alter Plasma Amino Acid Profiles and Hepatic Gene Expression in Mice Offspring
Authors: Miyoshi Moe , Saito Kenji , Jia Huijuan , Kato Hisanori
Published: March 2022

Maternal undernutrition during pregnancy is closely associated with epigenetic changes in the child, and it affects the development of obesity throughout the child’s life. Here, we investigate the effect of fetal low protein exposure and post-weaning high-fat consumption on plasma amino acid profiles and hepatic gene expression. Mother C57BL/6J mice were fed a 20% (CN) or 9% (LP) casein diet during pregnancy. After birth, the male offspring of both these groups were fed a high-fat diet (HF) from 6 to 32 weeks. At 32 weeks, the final body weight between the two groups remained unchanged, but the LP-HF group showed markedly higher white fat weight and plasma leptin levels. The LP-HF group exhibited a significant increase in the concentrations of isoleucine, leucine, histidine, phenylalanine, serine, and tyrosine. However, no differences were observed in the lipid content in the liver. According to the hepatic gene expression analysis, the LP-HF group significantly upregulated genes involved in the chromatin modification/organization pathways. Thus, maternal low protein and a post-weaning high-fat environment contributed to severe obesity states and changes in gene expression related to hepatic chromatin modification in offspring. These findings provide novel insights for the prevention of lifestyle-related diseases at the early life stage.
Discrimination of the Red Jujube Varieties Using a Portable NIR Spectrometer and Fuzzy Improved Linear Discriminant Analysis
Authors: Qi Zuxuan , Wu Xiaohong , Yang Yangjian , Wu Bin , Fu Haijun
Published: March 2022

In order to quickly, nondestructively, and effectively distinguish red jujube varieties, based on the combination of fuzzy theory and improved LDA (iLDA), fuzzy improved linear discriminant analysis (FiLDA) algorithm was proposed to classify near-infrared reflectance (NIR) spectra of red jujube samples. FiLDA shows performs better than iLDA in dealing with NIR spectra containing noise. Firstly, the portable NIR spectrometer was employed to gather the NIR spectra of five kinds of red jujube, and the initial NIR spectra were pretreated by standard normal variate transformation (SNV), multiplicative scatter correction (MSC), Savitzky-Golay smoothing (S-G smoothing), mean centering (MC) and Savitzky-Golay filter (S-G filter). Secondly, the high-dimensional spectra were processed for dimension reduction by principal component analysis (PCA). Then, linear discriminant analysis (LDA), iLDA and FiLDA were applied to extract features from the NIR spectra, respectively. Finally, K nearest neighbor (KNN) served as a classifier for the classification of red jujube samples. The highest classification accuracy of this identification system for red jujube, by using FiLDA and KNN, was 94.4%. These results indicated that FiLDA combined with NIR spectroscopy was an available method for identifying the red jujube varieties and this method has wide application prospects.
Irradiance Nowcasting by Means of Deep-Learning Analysis of Infrared Images
Authors: Niccolai Alessandro , Orooji Seyedamir , Matteri Andrea , Ogliari Emanuele , Leva Sonia
Published: March 2022

This work proposes and evaluates a method for the nowcasting of solar irradiance variability in multiple time horizons, namely 5, 10, and 15 min ahead. The method is based on a Convolutional Neural Network structure that exploits infrared sky images acquired through an All-Sky Imager to estimate the range of possible values that the Clear-Sky Index will possibly assume over a selected forecast horizon. All data available, from the infrared images to the measurements of Global Horizontal Irradiance (necessary in order to compute Clear-Sky Index), are acquired at SolarTechLAB in Politecnico di Milano. The proposed method demonstrated a discrete performance level, with an accuracy peak for the 5 min time horizon, where about 65% of the available samples are attributed to the correct range of Clear-Sky Index values.
Extremal Solutions of Generalized Caputo-Type Fractional-Order Boundary Value Problems Using Monotone Iterative Method
Authors: Derbazi Choukri , Baitiche Zidane , Abdo Mohammed S. , Shah Kamal , Abdalla Bahaaeldin , Abdeljawad Thabet
Published: March 2022

The aim of this research work is to derive some appropriate results for extremal solutions to a class of generalized Caputo-type nonlinear fractional differential equations (FDEs) under nonlinear boundary conditions (NBCs). The aforesaid results are derived by using the monotone iterative method, which exercises the procedure of upper and lower solutions. Two sequences of extremal solutions are generated in which one converges to the upper and the other to the corresponding lower solution. The method does not need any prior discretization or collocation for generating the aforesaid two sequences for upper and lower solutions. Further, the aforesaid techniques produce a fruitful combination of upper and lower solutions. To demonstrate our results, we provide some pertinent examples.
Torrefaction and Densification of Wood Sawdust for Bioenergy Applications
Authors: Alizadeh Peyman , Tabil Lope G. , Adapa Phani K. , Cree Duncan , Mupondwa Edmund , Emadi Bagher
Published: March 2022

In this study, wood sawdust as waste residue from wood processing mills was pretreated using torrefaction to improve fuel properties and densified to facilitate transportation. Sawdust was torrefied in a fixed bed reactor using inside temperatures (IT) of 230, 260 and 290 °C for 15, 30 and 45 min, residence time. Due to the low calorific value of the treatments, the outside temperature (OT) of the fixed bed reactor was used instead for a fixed duration of 45 min, which resulted in an increase in energy value by 40% for the most severe conditions. The mechanical strength of the pellets was enhanced by adding 20% binder (steam-treated spruce sawdust) to biochar, which improved the pellet tensile strength by 50%. Liquid by-products from the torrefaction process contained furfural and acetic acid, which can be separated for commercial uses. Thermochemical analysis showed better fuel properties of OT torrefied samples such as high fixed carbon (52%), low volatiles (41%) and lower oxygen contents (27%) compared to IT torrefied samples (18, 77 and 43%, respectively). Low moisture uptake of torrefied pellets compared to raw pellets, along with other attributes such as renewability, make them competent substitutes to fossil-based energy carriers such as coal.
A Review of Various Fast Charging Power and Thermal Protocols for Electric Vehicles Represented by Lithium-Ion Battery Systems
Authors: Makeen Peter , Ghali Hani A. , Memon Saim
Published: March 2022

Despite fast technological advances, the worldwide adoption of electric vehicles (EVs) is still hampered mainly by charging time, efficiency, and lifespan. Lithium-ion batteries have become the primary source for EVs because of their high energy density and long lifetime. Currently, several methods intend to determine the health of lithium-ion batteries fast-charging protocols. Filling a gap in the literature, a clear classification of charging protocols is presented and investigated here. This paper categorizes fast-charging protocols into the power management protocol, which depends on a controllable current, voltage, and cell temperature, and the material aspects charging protocol, which is based on material physical modification and chemical structures of the lithium-ion battery. In addition, each of the charging protocols is further subdivided into more detailed methodologies and aspects. A full evaluation and comparison of the latest studies is proposed according to the underlying parameterization effort, the battery cell used, efficiency, cycle life, charging time, and increase in surface temperature of the battery. The pros and cons of each protocol are scrutinized to reveal possible research tracks concerning EV fast-charging protocols.