bluuebunny/crossref_metadata_2025 huggingface dataset:
Ischemic-Hemorrhagic Stroke in New Onset Type 1 Diabetes Mellitus with Diabetic Ketoacidosis in a Two-Year-Old Toddler: The First Reported Case in Indonesia
Authors: Halim Anita , Harsono Felicia , Orlin Sisilia , Octavius Gilbert Sterling
Published: December 2023

Cerebral edema accounts for 90% of intracerebral complications in diabetic ketoacidosis (DKA). Stroke has been reported to account for 10% of intracerebral complications of DKA in children. It may be underrecognized because its presentation may be subtle. This case report aims to raise awareness of stroke presentation and risk factors in pediatric DKA. A previously healthy two-year-old female presented to the emergency department one day before admission with loss of consciousness and was diagnosed with DKA. The recognition of left hemiparesis was on the 9th day of hospitalization. After 14 days of hospitalization, the patient had recurrent seizures. Computed tomography and angiography revealed subacute ischemic transformative to subacute hemorrhagic stroke. During the follow-up, the symptoms of hemiparesis improved with routine physiotherapy, with some partial palsy of the third cranial nerve remaining. Risk factors for stroke in the patient were the severity of dehydration during DKA, younger age of onset, delayed DKA treatment, and iron deficiency anemia. Suspicion of stroke is necessary even if a subtle neurologic deficit occurs.
Healthcare in Asymmetrically Smart Future Environments: Applications, Challenges and Open Problems
Authors: Dowdeswell Barry , Sinha Roopak , Kuo Matthew M. Y. , Seet Boon-Chong , Hoseini Ali Ghaffarian , Ghaffarianhoseini Amirhosein , Sabit Hakilo
Published: December 2023

The Internet of Medical Things (IoMT) offers promising ways to meet healthcare needs of patients recovering in their own homes and other environments. Interconnected and resilient smart systems offer innovative and cost-effective ways of supporting patients by capitalizing on available devices and networking infrastructure. However, future environments will not be uniformly smart, and there will be asymmetries where our environments’ (home, work, etc.) resources and capabilities differ. Technological solutions will need to adapt to such asymmetries and provide high-quality service and equitable healthcare. This article presents a systematic mapping study that explores opportunities and challenges in building next-generation IoMT smart systems for future environments. The study spans academic literature published in the decade from 2011 to 2021, profiling it from three distinct perspectives: Smart Systems, Future Environments, and Tech-Assisted Health. Each perspective was explored via a Domain Expert-Driven Systematic Mapping protocol to establish where the research is focused and to identify research gaps. From an initial search of 495 studies, 113 were mapped to a set of predefined ontology classes, spanning 6 strategic focus categories. The mapping identified sensing technologies for medical vitals and sensor fusion technologies to combine measurements for more complex analysis, cloud platforms, and connectivity challenges; health conditions that have received the most attention in healthcare smart systems; issues and opportunities in handling large data volumes in integrated smart systems; as well as security and privacy challenges. We find that future middleware frameworks will require a greater degree of interoperability and maturity to fully deliver value. Promising middleware and integration frameworks will require significant adaption and refinement to coexist effectively with current healthcare technologies. Privacy and security are critical factors in healthcare but are currently poorly supported by IoT infrastructures, especially across multiple environments.
Automated Hyperparameter Tuning in Reinforcement Learning for Quadrupedal Robot Locomotion
Authors: Kim MyeongSeop , Kim Jung-Su , Park Jae-Han
Published: December 2023

In reinforcement learning, the reward function has a significant impact on the performance of the agent. However, determining the appropriate value of this reward function requires many attempts and trials. Although many automated reinforcement learning methods have been proposed to find an appropriate reward function, their proof is lacking in complex environments such as quadrupedal locomotion. In this paper, we propose a method to automatically tune the scale of the dominant reward functions in reinforcement learning of a quadrupedal robot. Reinforcement learning of the quadruped robot is very sensitive to the reward function, and recent outstanding research results have put a lot of effort into reward shaping. In this paper, we propose an automated reward shaping method that automatically adjusts the reward function scale appropriately. We select some dominant reward functions, arrange their weights in a certain unit, and then calculate their gait scores so that we can select the agent with the highest score. This gait score was defined to reflect the stable walking of the quadrupedal robot. Additionally, quadrupedal locomotion learning requires reward functions of different scales depending on the robot’s size and shape. Therefore, we evaluate the performance of the proposed method on two different robots.
A 87 dB SNR and THD+N 0.03% HiFi Grade Audio Preamplifier
Authors: Kok Chiang Liang , Chia Kai Jing , Siek Liter
Published: December 2023

This paper presents a significant contribution to high-fidelity audio technology through the comprehensive design and implementation of an advanced audio-grade preamplifier integrated with a high-performance digital-to-analog converter (DAC). The versatility of the digital section allows seamless integration of audio sources from Universal Serial Bus (USB), Bluetooth, or Sony-Philips Digital interface (SPDIF). In addition, the preamplifier accommodates various analog sources, offering flexibility to users. The unique architecture features an innovative resistor network-based DAC and precision components in the analog section, paving the way for achieving unparalleled audio fidelity. The measured distortion values are remarkably low, with a total harmonic distortion plus noise (THD+N) of only 0.03%. Furthermore, the system exhibits a signal-to-noise ratio (SNR) of 87 dB, comparable to industry benchmark. The hardware design sections went into meticulous details, providing an in-depth exploration of each block of the project. The inclusion of test and measurement data from the actual prototype enhances the credibility of the proposed work. This research not only showcases the theoretical operation of the preamplifier and DAC stage but also validates the practical implementation through many rounds of testing and validation. Our proposed work contributes to the field of high-fidelity audio by presenting a novel solution that is comparable to industry standards. The design’s adaptability to many different audio sources, coupled with robust performance metrics, positions it as a benchmark in the field of audio reproduction. The measurement results and findings presented in this paper are poised to influence future advancements in HiFi audio technology.
Assessment of the Robustness of the European Gas System to Massive Gas Outages and Evaluation of the Effect of Increased Energy Efficiency on the Security of Gas Coverage in Different Countries
Authors: Rqiq Yassine , Luciani Laureana , Aranda Juan , Ballestin Victor
Published: December 2023

The aim of this paper is to simulate the European natural gas system in extreme situations and to determine its weaknesses in terms of demand coverage. An assessment has also been made of the targets set for existing energy efficiency regulations and their effects on the coverage of future natural gas demand. This document assesses the potential for energy efficiency improvements associated with European countries and the effect of such improvements on the lessening of the natural gas demand. Once the efficiency improvement potential has been identified, the results of demand coverage in various scenarios of natural gas supply cut-off via pipelines were studied. The expected result reflects the study of the effect of the presumed demand reduction, due to the improvement of energy efficiency, on the self-sufficiency of the natural gas network and the improvement of energy coverage for EU countries. To carry out this study, an evaluation of the current infrastructures was developed, the existing resources were optimized, and the independence of the system was quantified in relation to the current situation of natural gas consumption at the European level. The proposed model has resulted in improvements in the coverage of the demand of certain countries and has detected those with systems that are not robust enough to face extreme crisis situations. The main conclusions are that the natural gas system has improved considerably from 2009 to the present, and that, in the event of massive gas cuts, there is a real risk of being unable to cover the natural gas demand of several countries with a very high dependence on gas from Russia.
Research on the Influence of Pantograph Catenary Contact Loss Arcs and Zero-Crossing Stage on Electromagnetic Disturbance in High-Speed Railway
Authors: Yang Yixuan , Cao Hefei , Zhang Mingzhi , Su Zhiguo , Hu Man , Jin Mengzhe , Liu Shanghe
Published: December 2023

During train travel, various factors, such as body vibration, uneven contact lines, and hard spots on carbon sliding plates and over electric neutral zones, often lead to brief separation between the pantograph and the contact line, i.e., the pantograph catenary contact loss phenomenon. With the continuous increase in train speed and traction power, the probability of pantograph catenary contact loss occurrences rises with a gradual increase in the energy of electromagnetic radiation, making the pantograph catenary arc a primary source of interference affecting the electromagnetic safety of high-speed railways. Understanding the mechanism, characteristics, and influencing factors of electromagnetic interference caused by pantograph catenary contact loss discharges is of utmost importance for analyzing and resolving on-site equipment interference faults. Our analysis of the physical process of pantograph catenary contact loss reveals that when the distance between the pantograph and catenary is significant and the duration is lengthy, high-voltage breakdown occurs within the pantograph catenary gap as it comes close again after the complete extinguishing of the arc. To investigate the electromagnetic radiation characteristics resulting from high-voltage breakdown discharge arcs in the pantograph catenary contact loss process, we established a laboratory test platform for assessing the electromagnetic disturbance characteristics of high-voltage pantograph discharge. We designed a test procedure utilizing fixed-gap breakdown discharge to evaluate the impact of the arc zero-crossing stage on electromagnetic radiation disturbances. Our research indicates that when the pantograph catenary spacing remains constant, an increase in voltage level leads to an elevation in the current within the discharge circuit, resulting in an increased intensity of impulse radiation generated during pantograph catenary contact loss events. During the moment of gap breakdown, the antenna records the highest amplitude of electromagnetic radiation. Also, during the steady-state arc ignition phase of the pantograph catenary gap, the zero-crossing stage generates pulsed discharge currents within the circuit, accompanied by substantial electromagnetic radiation. As the arc current increases, the zero-crossing time shortens, and the pulse current during the zero-crossing process decreases, accompanied by a reduction in the excited electromagnetic radiation. These observations reveal novel characteristics of electromagnetic radiation disturbances during steady-state arc ignition. The outcomes of our study provide valuable insights that can contribute to our understanding of the characteristics and influencing factors of electromagnetic radiation in pantograph catenary contact loss discharges and offer theoretical guidance for the resolution of pantograph catenary contact loss interference faults.
Optimal Configuration of Hybrid Energy Storage Capacity in a Grid-Connected Microgrid Considering Laddering Carbon Trading and Demand Response
Authors: Xu Zhanpeng , Chen Fuxin , Yang Xuefan , Lu Qinfen
Published: December 2023

In order to enhance the carbon emission reduction capability and economy of the microgrid, a capacity optimization configuration method considering laddered carbon trading and demand response is proposed for a grid-connected microgrid consisting of photovoltaic, battery and hydrogen storage devices. Combined with the mathematical model and system structure of each unit in the microgrid, the integrated operation control strategy is determined in this paper. A demand response model containing three load types is developed to reduce the stress on the storage and generation side. A carbon-trading mechanism is introduced into the operating costs to establish a configuration model with annual overall profit and power supply reliability as the optimization objectives. The non-dominated sorting genetic algorithm II is used to optimize the capacity of each unit, and the effectiveness of this model is verified by taking a microgrid in a region in Northwest China as an example to analyze the impacts of ladder carbon trading and demand response on the configuration results and system operation.
The Energy Storage Technology Revolution to Achieve Climate Neutrality
Authors: Badea Ioana-Cristina , Șerban Beatrice-Adriana , Anasiei Ioana , Mitrică Dumitru , Olaru Mihai , Rabin Andrey , Ciurdaș Mariana
Published: December 2023

The intensive exploitation and usage of fossil fuels has led to serious environmental consequences, including soil, water, and air pollution and climate changes, and it has compromised the natural resources available for future generations. In this context, identifying new energy storage technologies can be considered a sustainable solution to these problems, with potential long-term effects. In this work, were analyzed different alternatives that can be suitable for replacing non-renewable sources, where hydrogen, wave, wind, or solar energies were considered. Although they have numerous advantages in terms of usage and substantially reducing the environmental impact, this paper is focused on lithium-ion batteries, whose high performance and safety during operation have made them attractive for a wide range of applications. The study of potential replacement technologies and the technical requirements for the main materials used is the starting point in reducing the environmental footprint, without affecting the technical capabilities, followed by the transition toward economic circularity and climate neutrality.
Just Transition in Biofuel Development towards Low-Carbon Economy: Multi-Actor Perspectives on Policies and Practices in Indonesia
Authors: Djatmika Prija , Listiningrum Prischa , Sumarno Theresia B. , Mahira Dararida F. , Sianipar Corinthias P. M.
Published: December 2023

Justice and sustainability are the foundation of fair and equitable biofuel development. Policies and practices are consequently necessary to support a just transition towards a low-carbon economy. Therefore, this study aimed to understand multi-actor perspectives on policies and practices relevant to the just transition in biofuel development. Applying a socio-legal approach based on the JUST framework, this study focused on the Indonesian biofuel industry, which is primarily driven by crude palm oil (CPO) production. This study also added comparative perspectives from Thailand’s biofuel industry. The primary data were gathered from in-depth interviews and focus group discussions (FGDs), while the secondary data were from research, policy, and other government archives. Based on the results, oil palm plantations in Indonesia and Thailand are crucial for macroeconomic development. However, smallholder farmers in Indonesia, especially independent ones that do not join farmer groups, remain marginalised by the current regulations. In fact, many benefits from biofuel practices and policies accumulate disproportionately towards large corporations, while marginalised groups bear the costs. The Indonesian Sustainable Palm Oil (ISPO) certification that should induce market accessibility and competitiveness has not fully reached most rural farmers. Furthermore, various overlapping regulations and perplexing data differences exist from multiple ministries and administrative levels. Thus, palm oil stakeholders in Indonesia demand a dedicated institution for integrated regulation and monitoring of the industry, similar to the National Palm Oil Policy Committee in Thailand. The myriad of legal, political, socio-economic, and justice issues thus necessitates all hands on deck to ensure a just transition for all stakeholders of the Indonesian biofuel industry.
Numerical Simulation Study on the Dynamics of Bluff-Body Flames under Oxygen-Lean Conditions
Authors: Deng Fuquan , Zhao Minwei , Qin Shunchuang , Wang Zhaokun , Xie Yongliang , Zheng Hongtao , Liu Xiao , Zhang Feng
Published: December 2023

As modern aeroengine combustors advance towards high temperatures, afterburners are inevitably affected by diminished oxygen content in incoming flows, thus affecting combustion efficiency, instability, and flammability limits. In this study, the dynamic combustion characteristics of V-shaped bluff body-stabilised diffusion flames were investigated using a large eddy simulation method with an oxygen mass fraction range of 14–23% and temperatures ranging from 900 to 1100 K. The results show the significant effects of oxygen content and inflow temperature on the flame/flow behaviours downstream of the bluff-body flame holder. In a separated shear layer, two distinct modes of flow/flame shedding are observed when varying the oxygen content and inflow temperature. The results show that BVK instability governs the far-field wake flow/flame features, whereas the oxygen concentration and temperature significantly affect their oscillation amplitudes. In addition, variations in the incoming oxygen content and temperature shift the axial position of the transition from KH instability to BVK instability. Finally, a spectral analysis is conducted to investigate the characteristics of pressure and heat release pulsations under different scenarios. This study highlights the importance of oxygen content on the combustion dynamics of bluff body-stabilised diffusion flames at various temperatures, which is essential for optimising combustion efficiency and stability in practical applications.
Current Status and Future Directions of Building Information Modeling for Low-Carbon Buildings
Authors: Liu Hui , Chen Yaru , Hu Youwen , Wang Zhenyu , Liu Chunlu
Published: December 2023

In recent years, with the intensification of climate change, the development of low-carbon buildings (LCBs) has gained great momentum, and building information modeling (BIM) is perceived as the most promising path. However, systematic integration, review, and analysis of research in the field of BIM for LCBs has been lacking, which may hinder the potential of BIM in assisting the achievement of the goal of LCBs. Therefore, this study explores the current research status of BIM for LCBs and the directions for further investigation. A hybrid literature review method was utilized, which consisted of quantitative and qualitative analyses. Firstly, a quantitative bibliometric analysis was conducted on 158 studies searched from the Web of Science core collection. The most influential institutions, journals, studies, and keywords were identified. The most often used terms were BIM, life-cycle assessment (LCA), design, construction, digital technologies (DTs), life cycle, and integration. Secondly, a systematic qualitative analysis was conducted of 117 carefully selected studies to identify the research focus of different stages (e.g., design, construction, operation, and demolition) of BIM for LCBs. The results showed that studies pertaining to BIM for LCBs mostly took a whole life-cycle perspective, followed by a focus on the design stage, while the volumes of studies focusing on BIM for LCBs in the operation and demolition stages were relatively small. Currently, research focuses on how the latest methods and technologies can be utilized to help reduce carbon dioxide emissions over the life cycle of a building, e.g., BIM-LCA and BIM combined with DTs. Lastly, the challenges and prospects of integrating BIM with LCA and emerging DTs for LCBs are discussed in depth. Five topics, such as BIM-based interdisciplinary collaboration and improving and validating the BIM integrated sustainability calculation models, are proposed as future research trends. This study points out the current research hotspots and future research trends in the field and builds a solid starting point for scholars who want to devote themselves to this field. For practitioners in LCBs, the research findings could serve as a practical reference for better understanding the potential of BIM for LCBs so as to take full advantage of BIM to more effectively realize the goal of LCBs.
Characterization and Analysis of Mechanical Vibrations in Photovoltaic Modules Transported by Road in Spain
Authors: Cuenca Jose , Alonso-Garcia M. Carmen , Balenzategui Jose Lorenzo
Published: December 2023

Large deployment of photovoltaic (PV) installation worldwide demands reliability assurance of the systems to maintain the confidence in the markets. With the diversity of PV applications, it is essential the detection of circumstances that can be the root of failure mechanisms, such as transportation and installation of the modules. They are one of the main sources of induced vibrations, which, in its turn, can provoke defects and damages in the PV modules. In this work, we have measured and analyzed tri-axial accelerations and mechanical vibration that photovoltaic crystalline modules withstand during transportation by road, including loading and unloading operations. We have also analyzed the natural oscillation frequencies, the resonance phenomena and the highest impacts. It is concluded that a proper fastening of the load inside the truck is necessary and that high impacts during loading and unloading should be avoided. Packing the modules to reduce vibrations is also recommendable. Several solutions to perform this are proposed.
Non-Intrusive Reduced-Order Modeling Based on Parametrized Proper Orthogonal Decomposition
Authors: Li Teng , Pan Tianyu , Zhou Xiangxin , Zhang Kun , Yao Jianyao
Published: December 2023

A new non-intrusive reduced-order modeling method based on space-time parameter decoupling for parametrized time-dependent problems is proposed. This method requires the preparation of a database comprising high-fidelity solutions. The spatial bases are extracted from the database through first-level proper orthogonal decomposition (POD). The algebraic relationship between the time trajectory/parameter positions and the projection coefficient is described by the linear superposition of the second-level POD bases (temporal bases) and the second-level projection coefficients (parameter-dependent coefficients). This decomposition strategy decouples the space-time parameter effects, providing a stable foundation for fast predictions of parametrized time-dependent problems. The mappings between the parameter locations and the parameter-dependent coefficients are approximated as Gaussian process regression (GPR) models. The accuracy and efficiency of the PPOD-ROM are demonstrated through two numerical examples: flows past a cylinder and turbine flows with a clocking effect.
A Low-Complexity Double Vector Model Predictive Current Control for Permanent Magnet Synchronous Motors
Authors: Dong Hongliang , Zhang Yi
Published: December 2023

Compared to the conventional finite control set model predictive control (FCS-MPC), the double vector model predictive current control (DVMPCC) for permanent magnet synchronous motors (PMSMs) has a better steady-state performance without significantly increasing the switching frequency. However, determining optimal vectors with their dwell times requires a high computational burden. A low-complexity DVMPCC in the steady state was proposed in this study to address this problem. Firstly, the operating state of the motor was judged according to the speed error. During steady-state operation, the first optimal active vector was selected from three candidate vectors adjacent or identical to the active vector applied in the previous control period, reducing the number of comparisons by half. Next, the second optimal vector was selected from the other two active vectors, and the zero vector, the second optimal vector with the duty cycle, was determined according to the deadbeat condition of the q-axis current and cost function minimization. Finally, simulation and experimental results proved that the proposed low-complexity DVMPCC for surface-mounted permanent magnet synchronous motors is practical and feasible.
Thermo-Economic Analysis and Multi-Objective Optimization of a Poly-Generation System Based on Solid Oxide Fuel Cell/Gas Turbine/Multi-Effect Distillation and Absorption Chiller Using Biogas as Fuel
Authors: Liu Yang , Yu Xuechao , Lu Haozheng , Tian Chongyi
Published: December 2023

A poly-generation system for cooling, heating, power, and fresh water is proposed, based on SOFC/GT/MED and an absorption chiller, with biogas as fuel. The performance of the system under the designed condition is analyzed using energy, exergy, and economic methods. An efficiency of 69.02% for comprehensive energy utilization and 35.56% for exergy are demonstrated by simulation results under the designed condition. A freshwater production of 469.93 kg/h is achieved, and a cost rate of 22.51 USD/h is incurred by the system. The effects of various parameters on the system characteristics are examined. Multi-objective optimization methods are employed to determine the final optimum operating condition that yields the best results in two schemes with different objectives. In comparison to the initial design, the optimization of the first scheme results in a 4.58% increase in the comprehensive energy utilization rate and a 2.02% increase in the exergy efficiency. However, the cost rate of the entire system increases by 0.63 USD/h. On the other hand, the optimization of the second scheme leads to a 19.51 kW decrease in the total energy output, a 276.38 kg/h increase in the freshwater production rate, and a 0.42 USD/h decrease in the cost rate of the entire system.
MPPT Strategy of Waterborne Bifacial Photovoltaic Power Generation System Based on Economic Model Predictive Control
Authors: Tang Minan , Li Jinping , Qiu Jiandong , Guo Xi , An Bo , Zhang Yaqi , Wang Wenjuan
Published: December 2023

At present, the new energy industry represented by photovoltaics has become the main force to realize the optimization of China’s energy structure and the goal of “double carbon”; with the absence of land resources, the waterborne bifacial photovoltaic has ushered in a new opportunity. Therefore, in order to address the problem that the maximum power point tracking (MPPT) of photovoltaics (PV) could not take into account, the dynamic economic performance in the control process, an economic model predictive control (EMPC), is proposed in this work to realize the MPPT of the waterborne bifacial PV power generation system. Firstly, the model of the bifacial PV module is constructed by combining the ray-tracing irradiance model and considering the effect of water surface albedo on the irradiance absorbed by the module. Secondly, the EMPC controller is designed based on the state-space model of the system to maximize the power generation as the economic performance index, and to solve the optimal input variables time by time to achieve a rolling optimization with the operational requirements of the system itself as the constraints. Thirdly, the MATLAB/Simulink (R2022a) simulation experimental results verify that the EMPC strategy could be utilized to achieve MPPT of the waterborne bifacial PV power generation system, according to the changes of environment. Finally, it is also demonstrated that the bifacial PV power generation system that employed the EMPC strategy outperformed the traditional MPPT algorithm, with respect to both output power tracking velocity and accuracy, and the power generation could be improved by about 6% to 14.5%, which significantly enhances the system’s dynamic process economics.
Design Optimization of Induction Motors with Different Stator Slot Rotor Bar Combinations Considering Drive Cycle
Authors: Mahmouditabar Farshid , Baker Nick J.
Published: December 2023

In this paper, a sequential Taguchi method for design optimization of an induction motor (IM) for an electric vehicle (EV) is presented. First, a series of empirical and mathematical relationships is systematically applied to reduce the number of possible stator slot rotor bar (SSRB) combinations. Then, the admissible optimal combinations are investigated and compared using finite element (FE) simulation over the NEDC driving cycle, and the three best combinations are selected for further analysis. Each topology is optimized over the driving cycle using the k-means clustering method to calculate the representative working points over the NEDC, US06, WLTP Class 3, and EUDC driving cycles. Then, using the Design of Experiment (DOE)-based Taguchi method, a multi-objective optimization is carried out. Finally, the performance of the optimized machines in terms of robustness against manufacturing tolerances, magnetic flux density distribution, mechanical stress analysis, nominal envelope curve and efficiency map is carried out to select the best stator slot rotor bar combination. It is also found that the K-means clustering method is not completely robust for the design of electric machines for electric vehicle traction motors. The method focuses on regions with high-density working points, and it is possible to miss the compliant with the required envelope curve.
Concentration of CO2 in the Local Working Area during the Joint Operation of a Gas Infrared Heater and an Air-Exchange System
Authors: Borisov Boris Vladimirovich , Kuznetsov Geniy Vladimirovich , Maksimov Vyacheslav Ivanovich , Nagornova Tatiana Aleksandrovna , Salikhov Felix Yurievich
Published: December 2023

The formation of local areas in large buildings with regulated thermal conditions is an urgent task. The use of gas infrared heaters for this purpose raises questions on the utility of an air-exchange system and the monitoring of the combustion product concentration. In this study, the modeling of heat transfer processes on premises with a gas infrared heater and an air-exchange system was conducted. The carbon dioxide concentration in the local working area when using a light-type gas infrared heater was determined. The regularities of current formation for circulating air and combustion products on the premises at various air-exchange rates were analyzed. The profiles of CO2 temperatures and concentrations in the local working areas on the left and right of the equipment model are shown. The article makes a conclusion about the influence of air velocity from the air-exchange system based on average values of carbon dioxide concentration on the premises and in the local working area. The possibility of increasing the temperature in the local working area without exceeding the permissible CO2 concentrations (less than 1000 ppm) has been identified. The formulated approach allows us to predict the available modes of the air-exchange system to create the highest possible comfort heating parameters while maintaining an acceptable degree of air pollution from combustion products.
Double-Side Feeding and Reactive Power Compensation Using the Railway Interline Power Flow Controller
Authors: Martins António Pina , Morais Vítor Alves
Published: December 2023

This paper gives an overview of the operating characteristics of the railway interline power flow controller (RIPFC) regarding the capability of transferring active power between two sections of an electrified railway line separated by a neutral zone and proposes its use for compensating the power factor at the substation instead of regulating the voltage level at the neutral zone. The basic analysis is based on simplified steady-state models for the energy supply architecture, while detailed time-domain simulations are used for more realistic tests. The paper mainly focus on active power balancing between two neighbouring substations and the global losses in the system. Other functionalities of the RIPFC system are also analysed, like reactive power compensation at the substations. The paper presents the main operating principles of the system, shows results for some representative scenarios (generic and reduced) and discusses the results. The most relevant conclusions are related to substation active power balancing and peak shaving, power factor compensation in the substation, voltage stability at the neutral zone and system power losses.
A Dynamic Multiple Reaction Monitoring Analytical Method for the Determination of Fungicide Residues in Drinking Water
Authors: Arvanitidis Aggelos , Adamidis George S. , Parlakidis Paraskevas , Gikas Georgios D. , Alexoudis Christos , Vryzas Zisis
Published: December 2023

The extensive use of fungicides causes their continuous release into the environment through spraying, soil seepage, leaching, and runoff. It has been observed that their residues can be found in foods and a variety of environmental compartments, such as wastewater, lakes, rivers, sediments, drinking water sources (groundwater and surface water), treated water, and drinking water. A sensitive GC-MS/MS, using dynamic multiple reaction monitoring, an analytical method was developed to determine 10 fungicides (azoxystrobin, boscalid, captan, cyproconazole, cyprodinil, hexaconazole, metalaxyl, myclobutanil, paclobutrazol, and prochloraz) in drinking water. A solid-phase extraction method for sample preparations and validations was performed according to SANTE 2019 guidelines. All fungicides demonstrated mild or medium matrix effects (ME) ranging from 40.1% to 11.2%. Their recoveries ranged between 60% and 110%. The limits of detection were equal to or higher than 0.01 μg/L. The method was employed on 18 drinking water samples collected from public taps in Northern Evros, Greece, distributed in six sampling sites. Azoxystrobin, boscalid, cyproconazole, cypronidil, metalaxyl, and paclobutrazol mean concentrations did not surpass the allowable limit of 0.1 μg/L set by EU in any sampling site. Hexaconazole mean concentrations were higher than 0.1 μg/L in one sampling site, while prochloraz mean concentration showed limit exceedances in all sampling sites. Captan was not detected in any sampling site, and myclobutanil mean concentrations demonstrated exceedances of the permissible limit in four sampling sites. The presence of fungicide residues in the studied area is mainly due to the occasional point-sources pollution and preferential flow. Additionally, through the use of water, the risk of pesticides to human health was assessed for two different age groups. The sum of the hazard quotient values in each of the studied drinking water was less than unity. Consequently, the acute risk assessment procedure regards the examined drinking water as safe. Nevertheless, as prochloraz carcinogenic risk values were higher than the safe limit suggested by USEPA for both age groups, the existence of prochloraz residues raises concerns about chronic toxicity.
Sicilian Whey: Utilization of Ricotta Whey in the Production of Value-Added Artisanal Beers
Authors: Pasta Catia , Caccamo Margherita , Petriglieri Rosario , Difalco Antonio , Farina Giovanni , Belvedere Giovanni , Marino Giovanni , Marino Vita Maria , Garavaldi Anna , Musi Valeria , Alcaine Samuel D.
Published: December 2023

Scotta is an underutilized whey by-product of ricotta making. In this study, we investigated the utilization of scotta in beer production. To understand the quality of regional scotta, samples from eight Sicilian ricotta makers were analyzed for pH, total protein, fat, lactose, titratable acidity, % salt, total plate count, lactic acid bacteria counts, and minerals. Overall, the samples had low amounts of residual protein and fat. The average lactose content was 4.81 g/100 mL ± 0.52 g, with a pH of 6.12 ± 0.17 and a salt content of 1.05% ± 0.24. The majority of lactic acid bacteria counts were below the limit of detection. The total plate counts were more variable, ranging between 102 to 103 CFU/mL, suggesting occasional post-processing contamination during handling. Scotta was then used to replace some of the water and sugar in the production of two beer styles: (i) a Gose, a salty and acidified German beer style, and (ii) a sweet milk stout. A trained panel used for sensory analysis found that these prototypes fit within the sensory profiles of commercial beers of these styles. This work highlights opportunities to upcycle dairy by-products into novel fermented beverages that would be appealing to consumers.
Impacts of Mask Wearing and Leakages on Cyclic Respiratory Flows and Facial Thermoregulation
Authors: Barari Kian , Si Xiuhua , Xi Jinxiang
Published: December 2023

Elevated face temperature due to mask wearing can cause discomfort and skin irritation, making mask mandates challenging. When thermal discomfort becomes intolerable, individuals instinctively or unknowingly loosen or remove their facemasks, compromising the mask’s protective efficacy. The objective of this study was to numerically quantify the microclimate under the mask and facial thermoregulation when wearing a surgical mask with different levels of misfit. An integrated ambient–mask–face–airway computational model was developed with gaps of varying sizes and locations and was validated against complementary experiments. The low Reynolds number (LRN) k-ω turbulence model with porous media was used to simulate transient respiratory flows. Both skin convective heat transfer and tissue heat generation were considered in thermoregulation under the facemask, besides the warm air exhaled from the body and the cool air inhaled from the ambient. The results of this study showed that when wearing a surgical mask with a perfect fit under normal breathing, the temperature at the philtrum increased by 4.3 °C compared to not wearing a mask. A small gap measuring 0.51 cm2 (gap A) at the nose top resulted in 5.6% leakage but reduced the warming effect by 28% compared to zero gap. Meanwhile, a gap of 4.3 cm2 (R1L1) caused 42% leakage and a 62% reduction in the warming effect. Unique temporospatial temperature profiles were observed at various sampling points and for different gap sizes, which correlated reasonably with the corresponding flow dynamics, particularly close to the gaps. The temperature change rate also exhibited patterns unique to the gap site and sampling point, with distinctive peaks occurring during the inspiratory–expiratory flow transitions. These results have the significant implications that by using the temporospatial temperature profiles at several landmark points, the gap location can potentially be pinpointed, and the gap size and leakage fractions can be quantified.
Visualization of the Two-Phase Flow Behavior Involved in Enhanced Dense Phase Carbon Dioxide Pasteurization by Means of High-Speed Imaging
Authors: Hoferick Ratka , Schönherr Holger , Barbe Stéphan
Published: December 2023

This research explores the two-phase flow behavior involved in enhanced dense phase carbon dioxide inactivation of E. coli DH5α, which has been shown to possess a high microbial reduction efficiency of up to 3.7 ± 0.4 log. We present an experiment in which the liquid sample was pressurized with liquid carbon dioxide to 8.2 MPa and, after saturation, was forced to flow through a mini tube. An experimental setup was developed to visualize the flow patterns (plug, slug and churn flows) occurring in the mini tube by means of high-speed imaging. The values of the wall shear stress were estimated within the mini tube with the help of the gas slug velocities (8–9 m/s) and were compared with threshold shear stress values reported for the disruption of fresh E. coli cells. The results suggest that the preliminary pressurization phase may cause a substantial destabilization of the cell wall of E. coli DH5α.
Sorption Isotherms and Thermodynamic Characteristics of Gelatin Powder Extracted from Whitefish Skin: Mathematical Modeling Approach
Authors: Fikry Mohammad , Benjakul Soottawat , Al-Ghamdi Saleh , Mittal Ajay , Nilsuwan Krisana , Fulleros Ronnel , Dabbour Mokhtar
Published: December 2023

Moisture adsorption and desorption isotherms of gelatin extracted from whitefish skin powder (FSGP) at different temperatures across a wide range of water activity were determined along with their thermodynamic properties. Nine mathematical models were utilized for fitting the experimental data and simulating the adsorption and desorption behavior. The thermodynamic properties were determined and fitted to the experimental data. The results showed that Peleg and GAB models were the best fit for FSGP. The energies involved in the adsorption and desorption process of FSGP indicated a stronger dependence on equilibrium moisture content (Xe). When Xe decreased, there was a consistent trend of increasing thermodynamic properties. Both the moisture adsorption and desorption behaviors of FSGP were, therefore, non-spontaneous processes. Linear correlations between the changes in enthalpy and entropy for adsorption and desorption were observed, indicating the presence of enthalpy–entropy compensation for FSGP. For preserving FSGP quality, it should be stored with Xw ≤ 8 (gw/gdm, d.b.) at temperatures below 53 °C and an RH of 50% to avoid it becoming rubbery. These findings are crucial for providing insight into the optimal drying and storage conditions.
Oyster Peptide-Zinc Complex Ameliorates Di-(2-ethylhexyl) Phthalate-Induced Testis Injury in Male Mice and Improving Gut Microbiota
Authors: Lu Zhen , Huang Qianqian , Chen Fujia , Li Enzhong , Lin Haisheng , Qin Xiaoming
Published: December 2023

Di-(2-ethylhexyl) phthalate (DEHP) is a widely used plasticizer, which can cause damage to male reproductive organs, especially the atrophy of the testis. Meanwhile, DEHP can also lead to a decrease in testicular zinc content, but the role of zinc remains unclear. This study aims to prepare oyster peptide-zinc complex (OPZC) to alleviate DEHP-induced reproductive damage in mice. OPZC was successfully obtained through electron microscopy, X-ray diffraction, and thermogravimetric analysis, with stable structure and high water-solubility. Low dose oyster peptide-zinc complex (OPZCL) significantly reduced the reproductive damage caused by DEHP in mice. Further research had shown that OPZCL restored the content of serum hormones and the activity of oxidative stress kinases to normal, while also normalizing testicular zinc and selenium levels. In addition, it also recovered the disorder of gut microbiota, reduced the proportion of Bacteroides, increased the abundance of Ligilactobacillus, and restored the proportion of Acidobacteriota, Chloroflexi, and Proteobacteria. Therefore, OPZCL can relieve the reproductive damage caused by DEHP in mice by restoring testicular zinc homeostasis and the composition of intestinal microbiota, indicating that OPZCL has a potential protective effect on male reproductive health.
Leuconostoc citreum: A Promising Sourdough Fermenting Starter for Low-Sugar-Content Baked Goods
Authors: Roșca Maria-Florina , Păucean Adriana , Man Simona Maria , Chiș Maria Simona , Pop Carmen R. , Pop Anamaria , Fărcaș Anca C.
Published: December 2023

This review highlights Leuconostoc citreum’s promising possibilities as a proficient mannitol producer and its potential implications for sugar reduction, with a focus on its use in sourdough-based baked good products. Mannitol, a naturally occurring sugar alcohol, has gained popularity in food items due to its low calorie content and unique beneficial qualities. This study summarizes recent research findings and investigates the metabolic pathways and culture conditions that favor increased mannitol production by Leuconostoc citreum. Furthermore, it investigates the several applications of mannitol in baked goods, such as its function in increasing texture, flavor and shelf life while lowering the sugar content. Sourdough-based products provide an attractive niche for mannitol integration, as customer demand for healthier and reduced-sugar options increases.
Hypoglycemic Effect of Edible Fungi Polysaccharides Depends on Their Metabolites from the Fermentation of Human Fecal Microbiota
Authors: Yu Rongxuan , Luo Jianming , Liu Liu , Peng Xichun
Published: December 2023

Edible fungi polysaccharides are widely sourced and have various physiological activities, including hypoglycemic. Current studies mainly focus on the hypoglycemic activity of polysaccharides themselves, while the strength of the hypoglycemic activity of edible fungi polysaccharides from different sources remained elusive. This study compared the hypoglycemic activity of different edible fungi polysaccharides after in vitro fermentation by fecal bacteria, combined with non-targeted metabolomics and 16S rDNA analysis, to screen out potential key metabolites related to the hypoglycemic activity. The results show that the fermentation supernatants of all four edible fungi polysaccharides significantly increased the glucose consumption and glycogen synthesis of IR-HepG2, also up-regulated the level of hexokinase and down-regulated the level of phosphoenolpyruvate carboxylase. All fermentation supernatants could alleviate the insulin resistance of IR-HepG2 cells by regulating the expression levels of genes related to the IRS-1/PI3K/Akt signaling pathway. Gingerglycolipid A, sphinganine 1-phosphate, matricin, tricarballylic acid, N-carbamoylputrescine, nomega-acetylhistamine, tyramine, and benzamide could be considered as potential key metabolites to evaluate the hypoglycemic effects. Their levels were strongly positively correlated with the abundance of Candidatus_Stoquefichu, Faecalibacterium, Coprococcus, Bacteroides, Eubacterium_ventriosum_group, Anaerostipes, Parabacteroides, and Agathobacter. These metabolites and microorganisms are closely related to the hypoglycemic activity of edible fungi polysaccharides.
The Evaluation of Roasted Lentils (L. culinaris L.) Quick Meals as An Alternative to Meat Dishes
Authors: Ozolina Kristine , Beitane Ilze , Radenkovs Vitalijs , Straumite Evita , Valdovska Anda , Muizniece-Brasava Sandra
Published: December 2023

Despite the health-promoting benefits, the consumption of lentils in East Europe is low, attracting researchers’ interest in solving the problem. The aim of this study was to develop an alternative to animal proteins for nutrient-dense plant-based quick meals using roasted lentils as the primary raw material, performing sensory analysis, and evaluating the content of amino acids, minerals, and vitamins. The consumption of legumes in Latvia is also low, even though most respondents associate the use of legumes with a healthy choice. Roasted lentil quick meals can deliver 15.6% and 26.2% of the reference intake for protein. Furthermore, one-third of the amino acids (AAs) are essential AAs. AA values in prepared quick meals make them promising alternatives to meat products. One portion of ready-roasted lentils with Bolognese sauce provided above 15% of the daily reference intake of thiamin and vitamin B9. One portion of a ready-quick meal of tomato soup with roasted lentils and roasted lentils with Bolognese sauce provided 20.3% and 25.6% of iron, according to daily reference intake. Further studies on the bioavailability of quick meals must be conducted to claim they can replace meat nutritionally.