bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance Validation of High-Speed Motor for Electric Turbochargers Using Various Test Methods
Authors: Lee Tae-Woo , Hong Do-Kwan
Published: July 2023

As environmental regulations on automotive exhaust gas are gradually strengthened to cope with climate change, internal combustion engines, including those in hybrid electric vehicles, are continuously being downsized. Supercharging technologies are essential to compensate for the reduced engine power. One of the supercharging technologies, the turbocharger, has a response delay in the low-speed region, which is known as turbo lag. Various technologies have emerged to reduce turbo lag. Recently, electric supercharging technologies capable of reducing turbo lag using high-speed motors have been developed and commercialized. However, they are difficult to obtain for high-speed motors because of the cost of load performance test equipment. For this reason, many previous studies have compared analysis and experiment results under no-load conditions, or they have estimated performance in the high-speed region from results at low speed with light loads. This makes it difficult to know exactly how the performance of the motor is affected under loads applied to an actual system. In this study, performance test evaluation was conducted using a high-speed torque sensor, eddy current brake, and inertial dynamometer. Input/output power and efficiency were calculated using the measured voltage, current and output side torque and speed, and the results were compared.
Experimental Analysis of an Innovative Electrical Battery Thermal Management System
Authors: Cattani Luca , Malavasi Matteo , Bozzoli Fabio , D’Alessandro Valerio , Giammichele Luca
Published: July 2023

The aim of the present work is to develop and test an innovative cooling system for the thermal management of batteries for electric vehicles (EVs). At present, the technology most used for electric propulsion is based on lithium-ion cells. The power supply unit must often deliver a large amount of power in a short time, forcing the batteries to produce a considerable amount of heat. This leads to a high working temperature that can cause a sharp decrease in the battery performance or even a malfunction. Moreover, their working outside of the prescribed temperature range (20–40 °C) or with a significant temperature gradient across the battery meaningfully accelerates their aging or breakage. In this case, a battery thermal management system (BTMS) is necessary to allow the batteries to work as efficiently as possible. In the present work, a pulsating heat pipe with a three-dimensional structure is proposed as cooling technology for a battery pack. At first the performance of the proposed PHP is evaluated in a dedicated experimental setup under different boundary conditions and a wide spectrum of power input values. Then the PHP is tested by applying, as load at the evaporator section, heat power distribution corresponding to three different discharging processes of a battery. These tests, directly referring to an applicative case, show that the proposed 3D PHP has an optimal cooling ability and the possibility to offer a powerful solution for electrical battery thermal management.
Single-Wire Transmission Methods: Justification of a Single-Wire Resonant Power Transmission System
Authors: Bolshev Vadim , Yuferev Leonid , Vinogradov Alexander , Bukreev Alexey
Published: July 2023

Electricity supply as well as the provision of other forms of resources is one of the foundations of efficient agriculture. However, due to the reduction in the number of people living in rural settlements, there have been a large number of power lines with considerable lengths supplying small loads, hence resulting in an increase in power supply efficiency. A single-wire power transmission is an option for reducing the capital cost of power line construction by utilizing fewer conductors and fittings and lighter power transmission towers while lowering operational expenses. This paper considers the possible methods for single-wire energy transmission via the analysis of information sources such as Yandex and Google search engines; Scopus and Google Scholar scientific databases; and Cyber Leninka, eLIBRARY.ru, Elsevier, Springer, IEEE Xplore, and IGI Global electronic libraries. The conducted review revealed four alternatives: a single-wire earth return (SWER) system, a single-wire balanced line (B-Line), resonant wireless power transmission (SWPT) system, and a resonant single-wire power transmission system. The latter is of particular interest due to the lack of comprehensive and detailed information describing this technology, although it has distinct characteristics because of the peculiarities of the resonant mode of operation. The paper provides a comprehensive review of all existing published materials on the topic of “resonant systems for the transmission of electrical energy along a single wire”. The study covers the history of development and the structure of this system; describes its features, advantages, and the problems of using it; and the experience and fields of its application.
Photovoltaic Energy Forecast Using Weather Data through a Hybrid Model of Recurrent and Shallow Neural Networks
Authors: Castillo-Rojas Wilson , Medina Quispe Fernando , Hernández César
Published: July 2023

In this article, forecast models based on a hybrid architecture that combines recurrent neural networks and shallow neural networks are presented. Two types of models were developed to make predictions. The first type consisted of six models that used records of exported active energy and meteorological variables as inputs. The second type consisted of eight models that used meteorological variables. Different metrics were applied to assess the performance of these models. The best model of each type was selected. Finally, a comparison of the performance between the selected models of both types was presented. The models were validated using real data provided by a solar plant, achieving acceptable levels of accuracy. The selected model of the first type had a root mean square error (RMSE) of 0.19, a mean square error (MSE) of 0.03, a mean absolute error (MAE) of 0.09, a correlation coefficient of 0.96, and a determination coefficient of 0.93. The other selected model of the second type showed lower accuracy in the metrics: RMSE = 0.24, MSE = 0.06, MAE = 0.10, correlation coefficient = 0.95, and determination coefficient = 0.90. Both models demonstrated good performance and acceptable accuracy in forecasting the weekly photovoltaic energy generation of the solar plant.
Custom-Designed Pre-Chamber: Investigating the Effects on Small SI Engine in Active and Passive Modes
Authors: Sementa Paolo , Tornatore Cinzia , Catapano Francesco , Di Iorio Silvana , Vaglieco Bianca Maria
Published: July 2023

This work shows the results of an experimental campaign carried out in two spark ignition engines, a small optical research engine and its commercial counterpart, using a turbulent ignition system (pre-chamber) specifically designed for small engines. Advanced optical techniques and conventional methods were used to study the combustion process under various operating conditions. The pre-chamber operated actively in the research engine and passively in the commercial engine. Results showed that the pre-chamber configuration resulted in an increase in indicated mean effective pressure (IMEP) and a decrease in the coefficient of variation (CoV) of IMEP. These improvements compensated for challenges such as slow methane combustion rate, poor lean burn capability, and air displacement. In addition, the pre-chamber configuration exhibited lower fuel consumption and specific exhaust emissions compared to the standard ignition system. The novelty of this work lies in the successful implementation of the turbulent ignition system as a retrofit solution for SI engines, showing improved combustion efficiency and lower emissions. The study goes beyond previous efforts by demonstrating the benefits of the pre-chamber configuration in small engines without requiring extensive modifications. The results provide valuable insights into the automotive industry’s pursuit of engine optimization and highlight the significance of innovative approaches for spark ignition engines in contributing to sustainable mobility.
A Study on the Spatial Distribution and Gradient Transfer of Atmospheric Pollution Intensive Industries Such as the Thermal Power Industry in Hebei Province
Authors: Zhou Jingkun , Tian Juan , Wang Xiaoyan , Bai Xu
Published: July 2023

Owing to a long-term, extensive development model and inadequate industrial development planning, cases of atmospheric environment pollution frequently occur in Hebei province. By using such approaches as the Spatial Gini Coefficient, the Herfindahl–Hirschman Index and location entropy, this paper analyzes the spatial-distribution characteristics of atmospheric pollution-intensive industries such as the thermal power industry in Hebei province. As shown, atmospheric pollution-intensive industries, such as the thermal power industry in Hebei province, excessively cluster. As industrial agglomeration continuously intensifies, the spatial imbalance becomes increasingly prominent. Taking the number of days with excellent air quality as a benchmark, this paper divides prefecture-level cities of Hebei province into four types of industrial management and designs targeted strategies for the optimization of atmospheric pollution-intensive industries, such as the thermal power industry. In terms of policies, Type I and Type II cities are advised to strengthen the transfer of atmospheric pollution-intensive industries such as the thermal power industry, and Type III and Type IV cities are advised to improve capacities in atmospheric self-purification and green-technology innovation in a bid to help government departments to scientifically manage atmospheric pollution-intensive industries such as the thermal power industry.
Hybrid Energy Storage System Taking Advantage of Electric Vehicle Batteries for Recovering Regenerative Braking Energy in Railway Station
Authors: Jafari Kaleybar Hamed , Golnargesi Mostafa , Brenna Morris , Zaninelli Dario
Published: July 2023

Nowadays, nations are moving toward the electrification of the transportation section, and the widespread development of EV charging stations and their infrastructures supplied by the grid would strain the power grid and lead to overload issues in the network. To address this challenge, this paper presents a method for utilizing the braking energy of trains in railway stations to charge EVs located in strategic areas like park-and-ride regions close to railway stations improving energy efficiency and preventing grid overload. To validate the feasibility of the proposed system, a metro substation in Milan city is considered as a case study located in outskirts of the city and contains large number of parking space for vehicles. Three different scenarios are evaluated including DC fast charging station, AC low charging station and collaborative hybrid energy storage based AC charging station as EV charging station type. The results are studied for different EV population number, charging rate and the contractual power grid. Meanwhile, the possibility of proposed system in participating as V2G technology and taking advantage of the EV’s batteries to provide ancillary support to accelerating trains is investigated regarding peak shaving objective. The results indicated that the suggested interconnected system operates effectively when a significant quantity of EVs are parked at the station. However, the results revealed that the performance of the proposed system is notably influenced by other factors and a limited number of EVs during the early morning and late evening periods. Overall, this study confirms the feasibility of energy transfer between two types of transportation means in intermodal areas.
Real-Time Carbon Emissions Monitoring of High-Energy-Consumption Enterprises in Guangxi Based on Electricity Big Data
Authors: Zhou Chunli , Lin Xiqiao , Wang Renhao , Song Bowei
Published: July 2023

Real-time carbon emissions monitoring at the enterprise level is a crucial tool in shifting macrolevel carbon peak and carbon neutrality plans toward micro-level implementations. This study extends the existing CO2 emissions accounting framework to enterprise emissions monitoring. We analyze the correlation mechanism between electricity consumption and CO2 emissions by industries, calculate the electricity–CO2 coefficients, and finally model an enterprise-level real-time carbon emissions monitoring method based on electricity big data. Taking Guangxi region as a sample, the results show that (1) the proportion of electricity-related emissions is on the rising stage in Guangxi, with 441 g CO2/KWh emitted from electricity consumption in 2020, (2) the carbon emissions from the energy-intensive industries account for over 70% of the whole society, and they all have high electricity–CO2 coefficients, far exceeding the industry average of 1129 g/kWh, and (3) the monitoring method is applied to 1338 enterprises from over 40 industries. The emission characteristics reflect the regional and industrial heterogeneity. This enterprise-level monitoring method aims to optimize the carbon emissions calculation method toward higher temporal and spatial resolutions, so as to provide an important numerical basis for promoting carbon emission reduction and sustainable development.
An Overview of Active Control Techniques for Vortex Rope Mitigation in Hydraulic Turbines
Authors: Shtork Sergey , Suslov Daniil , Skripkin Sergey , Litvinov Ivan , Gorelikov Evgeny
Published: July 2023

This review addresses the current state of research into active control and suppression of vortex rope in hydroturbines under off-design operating conditions. Only active control methods that can be “switched on” when required under off-design operating conditions are considered in this work. The review focuses on air addition into the flow, as well as various auxiliary fluid jets. It includes all the best practices for vortex rope suppression in numerical and experimental studies. It can be inferred from the review that a modern flow control system should be comprehensive, designed for a specific hydroturbine geometry, and obtain feedback from the flow. Injecting ~2% of air from the impeller fairing cone appears optimal for suppressing pressure pulsations without significant efficiency loss. The cost of air injection is rarely estimated, but the use of an automatic venting system can minimize overheads and potentially improve efficiencies at low gas contents. Fluid jets ranging from 3% to 12% of the main flow rate can efficiently suppress pressure pulsations, but their high energy requirements limit their use. Azimuthal perturbation of the flow appears promising as it does not require significant energy loss, but practical implementation remains challenging as one needs to accurately know the system dynamics and be capable of real-time manipulation of the flow.
WRF Parameterizations of Short-Term Solar Radiation Forecasts for Cold Fronts in Central and Eastern Europe
Authors: Mierzwiak Michał , Kroszczyński Krzysztof , Araszkiewicz Andrzej
Published: July 2023

The solar power industry is a rapidly growing sector of renewable energy, and it is crucial that the available energy is accurately forecast. Using numerical weather prediction models, we can forecast the global horizontal irradiance on which the amount of energy produced by photovoltaic systems depends. This study presents the forecast effects for one of the most challenging weather conditions in modelling, occurring in central and eastern Europe. The dates of the synoptic situations were selected from 2021 and 2022. Simulations were carried out for 18 days with a cold front and, in order to verify the model configuration, for 2 days with a warm front, 2 days with an occlusion front and 2 days with a high pressure situation. Overall, 24 forecasts were made for each of the three parameterizations of the Weather Research and Forecasting model. The data were compared with the values measured in situ at the station performing the actinometric measurements belonging to Germany’s National Meteorological Service. This paper presents the spatial distribution of the global horizontal irradiance parameters for several terms to explain the differences between the results of the different simulations.
High Brightness Ce:Nd:YAG Solar Laser Pumping Approach with 22.9 W/m2 TEM00-Mode Collection Efficiency
Authors: Vistas Cláudia R. , Liang Dawei , Costa Hugo , Catela Miguel , Garcia Dário , Tibúrcio Bruno D. , Almeida Joana
Published: July 2023

A compact side-pumped solar laser design using a Ce:Nd:YAG laser medium is here proposed to improve the TEM00-mode solar laser output performance, more specifically the beam brightness. The solar laser performance of the Ce:Nd:YAG laser head was numerically studied by both ZEMAX® v13 and LASCADTM v1 software. Maximum multimode laser power of 99.5 W was computed for the 4.1 mm diameter, 34 mm length grooved rod, corresponding to a collection efficiency of 33.2 W/m2. To extract TEM00-mode solar laser, symmetric and asymmetric optical resonators were investigated. For the 4.1 mm diameter, 34 mm length grooved rod, maximum TEM00-mode solar laser collection efficiency of 22.9 W/m2 and brightness figure of merit of 62.4 W were computed using the symmetric optical resonator. While, for the asymmetric optical resonator, the maximum fundamental mode solar laser collection efficiency of 16.1 W/m2 and brightness figure of merit of 37.3 W were numerically achieved. The asymmetric resonator offered a TEM00-mode laser power lower than the one obtained using the symmetric resonator; however, a collimated laser beam was extracted from the asymmetric resonator, unlike the divergent TEM00-mode laser beam provided by the symmetric resonator. Nevertheless, using both optical resonators, the TEM00-mode Ce:Nd:YAG solar laser power and beam brightness figure of merit were significantly higher than the numerical values obtained by the previous Nd:YAG solar laser considering the same primary concentrator.
A Binary Archimedes Optimization Algorithm and Weighted Sum Method for UFLS in Islanded Distribution Systems Considering the Stability Index and Load Priority
Authors: Mohd Rosli Hazwani , Mokhlis Hazlie , Mansor Nurulafiqah Nadzirah , Md Sapari Norazliani , Halim Syahirah Abd , Wang Li , Sulaima Mohamad Fani
Published: July 2023

This study proposes an under-frequency load-shedding (UFLS) scheme based on a binary Archimedes Optimization Algorithm (BAOA) and the Weighted Sum Method (WSM) to maintain the stability of an islanded distribution system. These methods consider stability indices and load priorities to ensure effective load shedding during frequency deviations. The BAOA determines the optimal load shedding based on the stability index and power mismatch that minimizes the impact on critical loads while maintaining system stability in an islanded distribution system. The WSM determines the rank of the load to be shed based on four criteria: the load priority, the load category, the stability index, and the load size. Each load is assigned a weight based on its priority. These weight variables determine the order in which loads are shed during frequency deviations. The effectiveness of the proposed UFLS was tested on an 11 kV Malaysian distribution network with two mini hydro distributed generation systems. A comparative study was conducted based on five result outputs, including the number of loads shed, the size of the loads shed, the frequency undershoot, the frequency overshoot, and the time taken to achieve a stable frequency in three cases: base load, peak load, and peak load with photovoltaics (PV). The proposed UFLS showed the best results for 11 of 15 outputs (73.3%) for islanding events and 9 of 15 outputs (60%) for overloading events. The voltage profile and stability index, also, were improved after the proposed UFLS was applied.
Russian Arctic Mineral Resources Sustainable Development in the Context of Energy Transition, ESG Agenda and Geopolitical Tensions
Authors: Dmitrieva Diana , Solovyova Victoria
Published: July 2023

The Arctic region is well-known as a source of energy and mineral resources. Developing these resources by means of responsible practices could provide the world’s economy with strategically and critically important types of minerals. As a result, the role of the Arctic’s resource potential and the approaches used to develop it are gradually changing. In current conditions, it is crucial to strike a balance between existing needs and long-term demand for traditional energy sources or critical materials, such as rare and rare-earth minerals. Achieving this balance will result in sustainable growth, meeting ESG agenda targets while considering national security priorities, and devising novel approaches to sustainable project financing. However, there is controversy between existing strategies and plans based on low-carbon development and reality, which creates new macroeconomic and geopolitical obstacles that need to be overcome. The primary goal of this research is to substantiate the necessity of transforming the Russian Arctic’s mineral resource exploration in the context of global and national changes. The article presents a comprehensive analysis of the contemporary trends and tendencies influencing the exploration of the Arctic’s resources, as well as a general vision of the current situation in the energy sector. Research methods include content analysis and synthesis, generalization, decomposition, elements of strategic analysis, planning and forecasting, statistical methods, econometric modeling methods, and scenario planning. An upgraded concept of sustainable development based on six key components is proposed and discussed. Recommendations are provided on how to improve the existing system of long-term planning and forecasting to reduce the high level of macroeconomic and geopolitical uncertainty. The role of Russian Artic resources is determined in light of the shift in resource use.
Experimental Study of the Transient Behavior of a Wind Turbine Wake Following Yaw Actuation
Authors: Micheletto Derek , Fransson Jens H. M. , Segalini Antonio
Published: July 2023

Wind tunnel experiments were performed to investigate the response of a wind turbine model immersed in a replicated atmospheric boundary layer to dynamic changes in the yaw angle. Both the flow field in the wake and the operating properties of the turbine, namely its thrust force, torque, and angular velocity, were monitored during repeated yaw maneuvers for a variety of yaw angles. It was observed that the characteristic time scale of the transient experienced by the turbine scalar quantities was one order of magnitude larger than that of the yaw actuation and depended primarily on the inertia of the rotor and the generator. Furthermore, a Morlet wavelet analysis of the thrust signal showed a strong peak at the rotation frequency of the turbine, with the transient emergence of high activity at a lower frequency during the yaw maneuver. The insights provided by the proper orthogonal decomposition analysis performed on the wake velocity data enabled the development of a simple reduced-order model for the transient in the flow field based on the stationary states before and after the yaw maneuver. This model was then further improved to require only the final state, extending its applicability to any arbitrary wind farm as a dynamical surrogate of the farm behavior.
Investigation on Invasion Depth of Fracturing Fluid during Horizontal Fracturing in Low-Permeability Oil Reservoirs with Experiments and Mathematical Models
Authors: Zhao Haopeng , Zhang Yuan , Hu Jinghong
Published: July 2023

Multistage fracturing in horizontal well has become one of the important techniques for the efficient development of low-permeability sandstone reservoirs. In multistage hydraulic fractured horizontal wells (MHFHWs), the depth of fracturing fluid invasion into the formation is a key parameter evaluating the imbibition enhancement after fracturing. However, few studies have been conducted on the invasion depth of fracturing fluids combining experiments and mathematical models under high-pressure differences in MHFHWs. Therefore, in this work, a mathematical model with experimental validation is proposed for evaluating the fracturing fluids invasion under high pressure. We first conducted a series of displacement experiments under different pressure differences to obtain the breakthrough time and invasion velocity. All core samples are taken from the block X of Xinjiang oilfield. A mathematical model of fracturing fluid injection was then established, considering the two-dimensional filtration of fracturing fluid. Then, the calculated invasion velocity was validated against the experimental data. Afterward, the invasion depth and invasion volume were determined for this typical horizontal well. Results show that at the end of 72 min, the invasion depth reaches 1.516 m when measured by core experiments and 1.434 m when calculated by the proposed model. The total invasion volume of all fracturing stages is estimated as 21,560.05 m3 and the actual total fluid volume injected is 24,019.6 m3. The paper formed a scientific and reasonable evaluation method of fracturing fluid invasion depth during the fracturing of horizontal wells, which provides solid theoretical support for the effective evaluation of fracturing to improve oil recovery.
Sound Absorbing Properties of Selected Green Material—A Review
Authors: Jang Eun-Suk
Published: July 2023

Noise pollution is often overlooked and invisible, but it significantly impacts the quality of human life. One of the most straightforward solutions to mitigate noise pollution is by using sound-absorbing materials. Recently, research trends to develop sound absorbing green materials, typically derived from agricultural by-products, have witnessed an uptick. This paper summarizes the sound-absorbing properties of various green materials found in the literature, including coconut fiber, kenaf fiber, rice bran, rice husk, rice straw, Hanji (a traditional Korean paper), tea-leaf fiber, mandarin peel, pineapple-leaf fiber, corn husk, peanut shell, sugar palm trunk, yucca gloriosa fiber, fruit stones, wood barks, flax fiber, and nettle fiber. Natural fibers can be made by compressing the raw material or manufacturing them into fibrous materials or composites. The key variables that determine sound absorption performance are the thickness and density of the green material, as well as the presence of an air back cavity. Generally, thicker materials exhibit better sound absorption performance in the low- and mid-frequency range. Moreover, higher density is associated with better sound absorption performance at the same thickness. Additionally, increasing the distance between the sound-absorbing material and the air back cavity enhances sound absorption performance at low frequencies. Thus, these physical variables, rather than the specific materials used, primarily influence sound absorption capabilities. Therefore, various green materials, such as fibers, granules, and porous materials, can be effective sound absorbers if their thickness, density, and air back cavity are properly controlled.
Combining Traditional Ecological Knowledge and Scientific Observations to Support Mangrove Restoration in Madagascar
Authors: Ravaoarinorotsihoarana Lalao Aigrette , Ratefinjanahary Ismael , Aina Celestin , Rakotomahazo Cicelin , Glass Leah , Ranivoarivelo Lantoasinoro , Lavitra Thierry
Published: July 2023

Local communities play a key role in ecosystem restoration due to their invaluable traditional ecological knowledge. While community-led mangrove restoration has been practiced in Madagascar for decades, the factors influencing the success of the restoration remains understudied. Despite the extensive local knowledge, the complexity of factors influencing restoration success requires outside technical expertise. This study aimed to investigate the drivers of mangrove restoration success in southwest Madagascar. The survival rate of mangroves planted from 2015 to 2022, including Rhizophora mucronata, Bruguiera gymnorrhiza, and Ceriops tagal was assessed using the sampling methods for tree planting inventory with circular plots. R version 4.2.2 was used for descriptive statistics analysis. The correlation between the survival rate and plantation density, species composition, and number of participants was assessed using a Principal Component Analysis. As a result, the mean survival rate of the 440,990 planted mangroves, with a density of 4628 ± 317 trees/ha−1 was 82.5 ± 1.8%. Our study showed that plantation density and species composition are not correlated with survival rate. However, the survival rate is inversely correlated with the number of participants. The findings of this paper showed that both traditional ecological knowledge and scientific observations are vital to informing mangrove reforestation.
Development of Gluten-Free Functional Bread Adapted to the Nutritional Requirements of Celiac Patients
Authors: Peñalver Rocío , Ros Gaspar , Nieto Gema
Published: July 2023

Celiac patients suffer from nutritional deficiencies before and during the maintenance of a gluten-free diet; this is due to non-fortified, mostly processed foods that are high in saturated fat and deficient in minerals typically present in wheat. A literature search was carried out to determine the deficiencies of these patients in calcium, iron, fiber, folic acid, omega-3, vitamin B12 and vitamin D. Different formulations of gluten-free bread enriched with olive extract (hydroxytyrosol of natural (HXTO) and synthetic (HXTS) origin), acerola extract, citrus extract, spinach extract, calcium, iron and linseed were used. Antioxidant capacity, nutritional composition, folates, minerals, color and pH were studied, and a microbiological study and sensory analysis were conducted to assess organoleptic quality. These studies were carried out on days 0, 4, 7 and 11 to study their evolution. The results of the HXTS bread showed a higher antioxidant capacity, higher antimicrobial capacity and higher fiber content, as well as higher amounts of minerals. It also showed higher consumer acceptability, even relative to commercial gluten-free bread. The HXTO bread showed higher antimicrobial capacity than the control (C), higher fiber content and higher mineral content, but had lower antimicrobial capacity than HTXS bread. It also had better sensory acceptability than C but was worse than HXTS bread. Taking into account the physicochemical and organoleptic characteristics, the HXTS sample is the most suitable for enriching the diet of celiac patients.
Numerical Simulations of the NREL Phase VI Wind Turbine with Low-Amplitude Sinusoidal Pitch
Authors: Akbarzadeh Amir , Borazjani Iman
Published: July 2023

Currently, most wind turbine performance analyses and simulations are performed assuming constant pitch and yaw angles during each rotation. Nevertheless, induced vibration or rotor imbalance can affect the pitch or yaw angle within each rotation. In this study, the effects of low-amplitude sinusoidal pitch angle oscillations of the blade on the performance of a wind turbine was investigated numerically by comparing it against the baseline (without pitch variations). Large eddy simulations were performed in which the motion of blades was handled by the curvilinear immersed boundary (CURVIB) method. The grid resolution was increased near the moving immersed boundaries using dynamic overset grids to resolve rotating blades. It was found that low-amplitude (up to 3 degrees) sinusoidal oscillations in the pitch angle negligibly affected the mean torque but increased its fluctuations and created distinct features in the wake of the turbine. In fact, the turbine’s mean torque at wind speed of 15 m/s decreases from 1245 N.m to 1223 N.m, while its fluctuation (standard deviation) increases from 2.85 N.m to 7.94 N.m, with a dynamic pitch of 0.5 degrees and frequency of 3.6 Hz.
Study on the Variation Law of the Main Mechanical Properties in the Processing of Longjing Tea
Authors: Li Chen , Wang Xiaoyong , Zhang De , Chen Yuqiong , Jiang Xinfeng , Ni Dejiang
Published: July 2023

Fresh tea leaves, both single bud and one leaf with a bud, were used as the test materials in this study. The variation in the main mechanical properties, such as texture and tensile properties, during the processing of Longjing tea was examined by using texture profile analysis (TPA) and stress–strain tensile tests. The plasticity showed a trend of first increasing and then decreasing during the processing, whereas the elasticity displayed the opposite tendency. The flexibility reached a maximum during the fixing stage and then slowly declined with a relatively small change. Initially, the maximum force dropped down and then gradually elevated later.Both the tensile strength and the fracture strain indicated an upward movement at the beginning and then a downfall afterward. The elastic modulus changed little before the final panning stage, then raised significantly. The correlation analysis revealed that the flexibility of tea leaves was highly positively correlated with water content. At water content of 30% and 50%, the plasticity and flexibility of tea leaves reached a clear peak and the maximum force was at a low level, which is suitable for the shaping of Longjing tea. The results also demonstrated that the main mechanical properties of different tender materials change differently during the processing. The research findings can provide parameters for optimizing the mechanical design and processing technology of Longjing tea.
Fabrication of ɛ-Polylysine-Loaded Electrospun Nanofiber Mats from Persian Gum–Poly (Ethylene Oxide) and Evaluation of Their Physicochemical and Antimicrobial Properties
Authors: Souri Zahra , Hedayati Sara , Niakousari Mehrdad , Mazloomi Seyed Mohammad
Published: July 2023

In the present study, electrospun nanofiber mats were fabricated by mixing different ratios (96:4, 95:5, 94:6, 93:7, and 92:8) of Persian gum (PG) and poly (ethylene oxide) (PEO). The SEM micrographs revealed that the nanofibers obtained from 93% PG and 7% PEO were bead-free and uniform. Therefore, it was selected as the optimized ratio of PG:PEO for the development of antimicrobial nanofibers loaded with ɛ-Polylysine (ɛ-PL). All of the spinning solutions showed pseudoplastic behavior and the viscosity decreased by increasing the shear rate. Additionally, the apparent viscosity, G′, and G″ of the spinning solutions increased as a function of PEO concentration, and the incorporation of ɛ-PL did not affect these parameters. The electrical conductivity of the solutions decreased when increasing the PEO ratio and with the incorporation of ɛ-PL. The X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectra showed the compatibility of polymers. The antimicrobial activity of nanofibers against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was investigated, and the samples loaded with ɛ-PL demonstrated stronger antimicrobial activity against S. aureus.
Thymol@activated Carbon Nanohybrid for Low-Density Polyethylene-Based Active Packaging Films for Pork Fillets’ Shelf-Life Extension
Authors: Giannakas Aris E. , Karabagias Vassilios K. , Moschovas Dimitrios , Leontiou Areti , Karabagias Ioannis K. , Georgopoulos Stavros , Karydis-Messinis Andreas , Zaharioudakis Konstantinos , Andritsos Nikolaos , Kehayias George , Avgeropoulos Apostolos , Proestos Charalampos , Salmas Constantinos E.
Published: July 2023

Τhe replacement of food packaging additives and preservatives with bio-based antioxidant/antibacterial compounds has been a common practice in recent years following the trend of bioeconomy and nanotechnology. Such bio-additives are often enclosed in nanocarriers for a controlled release process. Following this trend in this work, a thymol (TO)-rich activated carbon (AC) nanohybrid was prepared and characterized physicochemically with various techniques. This TO@AC nanohybrid, along with the pure activated carbon, was extruded with low-density polyethylene (LDPE) to develop novel active packaging films. The codenames used in this paper were LDPE/xTO@AC and LDPE/xAC for the nanohybrid and the pure activated carbon, respectively. X-ray diffractometry, Fourier-transform infrared spectroscopy, and scanning electron microscopy measurements showed high dispersity of both the TO@AC nanohybrid and the pure AC in the LDPE matrix, resulting in enhanced mechanical properties. The active film with 15 wt.% of the TO@AC nanohybrid (LDPE/15TO@AC) exhibited a 230% higher water/vapor barrier and 1928% lower oxygen permeability than the pure LDPE film. For this active film, the highest antioxidant activity referred to the DPPH assay (44.4%), the lowest thymol release rate (k2 ≈ 1.5 s−1), and the highest antibacterial activity were recorded, resulting in a 2-day extension of fresh pork fillets’ shelf-life.
Combined Effects of Particle Size and Dough Improvers on Improving the Quality of Purple-Colored Whole Wheat Bread
Authors: Avarzed Enkhtungalag , Kweon Meera
Published: July 2023

Consumers’ interest in healthy products is increasing. However, the production of excellent-quality whole wheat bread (WWB) faces challenges due to the reduced gluten functionality and varied particle sizes of whole wheat flour (WWF). This study aimed to explore the enhancement of purple-colored WWB quality by controlling the particle size of WWF and using dough improvers. Six purple-colored WWFs were obtained using an ultra-centrifugal mill with different sieve openings (0.5 and 1.0 mm) and rotor speeds (6000, 10,000, and 14,000 rpm). The average particle diameter (d50) of the smaller particle size group (S) and the larger particle size group (L) based on the sieve opening ranged from 115 to 258 μm and 294 to 492 μm, respectively. Group S demonstrated higher water absorption, damaged starch, and gluten strength compared to group L. Additionally, group S exhibited a greater bread volume and height compared to group L. Among the tested dough improvers (vital wheat gluten, vitamin C, enzymes, and emulsifiers), vital wheat gluten was the most effective in improving the quality of purple-colored WWB. The improvement effect was significantly greater in group S than in group L. These findings suggest that controlling the particle size of purple-colored WWFs and utilizing dough improvers can result in superior-quality WWB.
Analysing Civilian Video Footage for Enhanced Scientific Understanding of the 2011 Tohoku Earthquake and Tsunami, Japan, with Implications for PNG and Pacific Islands
Authors: Mcdonough-Margison Caitlin , Hinchliffe Graham , Petterson Michael G.
Published: July 2023

Approximately 70% of global tsunamis are generated within the pan Pacific Ocean region. This paper reports on detailed analysis of civilian video footage from the 2011 Tohoku earthquake, Japan. Comprehensive scientific analysis of tsunami video footage can yield valuable insights into geophysical processes and impacts. Civili22an video footage captured during the 2011 Tohoku, East Honshu, Japan tsunami was critically examined to identify key tsunami processes and estimate local inundation heights and flow velocity in Kesennuma City. Significant tsunami processes within the video were captured and orientated in ArcGIS Pro to create an OIC (Oriented Imagery Catalogue). The OIC was published to ArcGIS Online, and the oriented imagery was configured into an interactive website. Flow velocity was estimated by quantifying the distance and time taken for an object to travel between two known points in the video. Estimating inundation height was achieved by taking objects with known or calculable dimensions and measuring them against maximum local inundation height observations. The oriented imagery process produced an interactive Experience Builder app in ArcGIS Online, highlighting key tsunami processes captured within the video. The estimations of flow velocity and local inundation height quantified during video analysis indicate flow speeds ranging from 2.5–4.29 m/s and an estimated maximum local run-up height of 7.85 m in Kesennuma City. The analysis of civilian video footage provides a remarkable opportunity to investigate tsunami impact in localised areas of Japan and around the world. These data and analyses inform tsunami hazard maps, particularly in reasonably well-mapped terrains with remote access to landscape data. The results can aid in the understanding of tsunami behaviours and help inform effective mitigation strategies in tsunami-vulnerable areas. The affordable, widely accessible analysis and methodology presented here has numerous applications, and does not require highly sophisticated equipment. Tsunamis are a significant to major geohazard globally including many Pacific Island states, e.g., Papua New Guinea, Solomon Islands, and Tonga. Video footage geoscientific analysis, as here reported, can benefit tsunami and cyclone storm surge hazards in the Pacific Islands region and elsewhere.
The Paradox of Sexual Dysfunction Observed during Pregnancy
Authors: Daescu Ana-Maria Cristina , Navolan Dan-Bogdan , Dehelean Liana , Frandes Mirela , Gaitoane Alexandru-Ioan , Daescu Andrei , Daniluc Razvan-Ionut , Stoian Dana
Published: July 2023

The aim of this study is to analyze the evolution of sexual function throughout pregnancy and highlight the predicting factors of sexual dysfunction in pregnant women. Our study included 144 participants, aged 16 to 45. Patients were evaluated three times during pregnancy by filling out the Female Sexual Function Index (FSFI) and the Body Exposure in Sexual Activities Questionnaire (BESAQ). At the time of the last evaluation, we asked patients to also fill out Beck’s Depression Inventory (BDI-II) and a questionnaire regarding their psychological status and relationship satisfaction. We observed that the FSFI lubrication, satisfaction, and pain domains and the FSFI total score significantly decreased from the 1st to the 3rd evaluation. We observed that an increase in BDI score and the presence of abortion in the patient’s history increase the risk of developing female sexual dysfunction (FSD). Higher BMIs were found to be a protective factor against FSD, as was being unmarried. The relationship satisfaction score was found to be an independent predictor of FSD. These findings support previous studies that indicate that pregnancy and postpartum sexuality are multifaceted phenomena and that psycho-social factors have a greater impact on sexuality than biological factors.
Defining Physician–Nurse Efforts toward Collaboration as Perceived by Medical Students
Authors: Dahlawi Hanan H. , Al obaidellah May M. , Rashid Najwa Abdur , Alotaibi Amal A. , Al-Mussaed Eman M. , Cheung Mary Mae M. , Abuaish Sameera , Cordero Mary Anne Wong
Published: July 2023

Collaboration between physicians and nurses is essential to healthcare delivery and is associated with high-quality patient care, greater patient satisfaction, and better health outcomes. Hence, it is imperative that doctors and nurses have a particular set of interprofessional collaboration skills. This descriptive cross-sectional study assessed how medical students in the pre-clinical and clinical years perceived attitudes toward collaboration between physicians and nurses in a hospital setting. The Jefferson Scale of Attitude toward Physician–nurse Collaboration (JSAPNC) was reverse-translated into Arabic for the current study. The results showed a total JSAPNC mean score of 46.55, lower than other medical students in other universities. In general, the results of the study showed no significant difference in the total JSAPNC score among medical students when analyzed according to age, clinical exposure, and year level, except in the two factors of JSAPNC: shared education and teamwork (p = 0.038) and caring as opposed to curing (p = 0.043). The findings of this study suggest the necessity of integrating interprofessional education (IPE) across the medical school curriculum because, as future physicians, medical students would be well equipped to treat their patients in partnership with their nursing colleagues.
Lessons for Medical and Health Education Learned from the COVID-19 Pandemic
Authors: Gardanova Zhanna , Belaia Olga , Zuevskaya Svetlana , Turkadze Klavdiya , Strielkowski Wadim
Published: July 2023

Our paper analyzes lessons for medical education and health education stemming from the experience gained in the course of the COVID-19 pandemic. Moreover, it tackles the issue of the social health and psychological wellbeing of medical students involved in online education during the COVID-19 pandemic. The paper systematizes up-to-date data on how medical schools and universities have adapted to the conditions of the COVID-19 pandemic and implemented novel effective solutions for the learning process, such as transitioning from traditional in-person classes to online learning, incorporating virtual simulations and telemedicine experiences for clinical training, and collaborating with health authorities to provide support in testing and contact tracing efforts. The paper contains an analysis of various aspects of medical education, such as the changes in practical classes, the impact of the pandemic on the formation of communication skills, methods for assessing students’ knowledge and skills, and many others. It also considers case studies related to the implementation of educational programs, methodologies, and novel digital technologies in a pandemic. Additionally, the paper features an empirical study that is based on the results of our own survey that was carried out with the help of a snowball convenient sampling that involved 710 medical students between 19 and 25 years of age (56% females and 44% males) from 4 Russian regions (Moscow, Krasnodar, Kazan, and Saint Petersburg). We applied the correlation between stress scores, anxiety scores, factors of stress, and strategies for coping with stress and various economic and demographic variables (age, environment, and gender) that were analyzed using the chi-square test. Our results demonstrate that over 85% of the students in our sample yielded an above-average vulnerability to stress due to the COVID-19 restrictions. At the same time, around 61% of the students experienced severe anxiety during online education in the COVID-19 pandemic. The important factors leading to stress and anxiety were the fear of getting infected and social distancing, and the best strategy to deal with stress and increase wellbeing was self-control. Through a comprehensive review of the literature and empirical estimations, our paper identifies key areas of improvement, including curriculum adaptation, technology integration, faculty development, student support, and interprofessional collaboration. The proposed recommendations aim at strengthening medical education systems and preparing healthcare professionals to effectively navigate future pandemics.