bluuebunny/crossref_metadata_2025 huggingface dataset:
Heat-Transfer Mechanisms in a Solar Cooking Pot with Thermal Energy Storage
Authors: Vanierschot Maarten , Mawire Ashmore
Published: March 2023

This paper presents a detailed analysis of the heat-transfer mechanisms in a solar cooking pot with thermal energy storage using computational fluid dynamics (CFD). The vast majority of studies on solar cookers have been experimentally performed using local temperature measurements with thermocouples. Therefore, the heat-transfer mechanisms can only be studied using lumped capacitance models as the detailed profiles of temperature and heat fluxes inside the cooker are missing. CFD is an alternative modelling technique to obtain this detailed information. In this study, sunflower oil is used as both cooking fluid and energy storage medium. Comparison of the model with the available experimental data shows that the deviation is within the measurement accuracy of the latter. Hence, despite some assumptions, such as axisymmetry and an estimation of the heat transfer parameters to the ambient, the model is able to describe the involved physical processes accurately. It is shown that, initially, the main heat-transfer mechanism is conduction from the cooker’s bottom towards the thermal energy storage (TES). This heats up the oil near the bottom of the TES, creating convective plumes, which significantly enhance the heat transfer. In equilibrium, about 79% of the incoming solar flux goes towards heating up the TES. The heat is further transferred to the pot, where convective plumes also appear much later in time. However, the heat transfer to the pot is much smaller, with an average heat-transfer coefficient of 1.6 Wm−2K−1 compared to 7.5 Wm−2K−1 for the TES. After two hours of charging, the oil reaches a temperature of 397 K in the TES and 396 K in the cooking pot. Moreover, the temperature distribution in the cooker is quasi-uniform. During the charging period, the storage efficiency of the TES is about 29%. With the results in this study, solar cooking pots with TES can be further optimized towards efficiently transmitting the heat form the solar radiation to the food to be cooked.
A Mini-Review of Current Activities and Future Trends in Agrivoltaics
Authors: Klokov Alexander , Loktionov Egor , Loktionov Yuri , Panchenko Vladimir , Sharaborova Elizaveta
Published: March 2023

Agrivoltaics (Agri-PV, AV)—the joint use of land for the generation of agricultural products and energy—has recently been rapidly gaining popularity, as it can significantly increase income per unit of land area. In a broad sense, AV systems can include converters of solar energy, and also energy from any other local renewable source, including bioenergy. Current approaches to AV represent the evolutionary development of agroecology and integrated PV power supply to the grid, and can result in nearly doubled income per unit area. AV could provide a basis for a revolution in large-scale unmanned precision agriculture and smart farming which will be impossible without on-site power supply, reduction of chemical fertiliser and pesticides, and yield processing on site. These approaches could dramatically change the logistics and the added value production chain in agriculture, and so reduce its carbon footprint. Utilisation of decommissioned solar panels in AV could halve the cost of the technology and postpone the need for bulk PV recycling. Unlike the mainstream discourse on the topic, this review feature focuses on the possibilities for AV to become more strongly integrated into agriculture, which could also help in resolution of relevant legal disputes (considered as neither rather than both components).
Investigations on Bi Doped Cu2Se Prepared by Solid State Reaction Technique for Thermoelectric Applications
Authors: Purushottam Bhat Chaithanya , Anusha  , Ani Aninamol , Shanubhogue U. Deepika , Poornesh P. , Rao Ashok , Chattopadhyay Saikat
Published: March 2023

The influence of Bi doping on the structural and thermoelectric properties of Cu2Se is presented in this work. Cu2−xBixSe (x = 0.00, 0.004, 0.008, 0.012) samples were prepared using conventional solid-state reaction techniques. According to room temperature XRD results, Cu2−xBixSe samples have a monoclinic crystal structure. Doping Bi to the Cu site acts as a donor, lowering the hole concentration, except for the sample with x = 0.004. The resistivity of the Cu2−xBixSe sample increases with an increase in Bi content. Seebeck coefficient data confirm that the holes are the charge carriers in Cu2−xBixSe samples. At 700 K, the Cu1.988Bi0.012Se sample has the highest power factor of 1474 μWm−1K−2, showing great potential in developing high-performance Cu2Se based thermoelectric materials.
3D Numerical Analysis of a Phase Change Material Solidification Process Applied to a Latent Thermal Energy Storage System
Authors: Porto Tulio R. N. , Lima João A. , Andrade Tony H. F. , Delgado João M. P. Q. , Lima António G. B.
Published: March 2023

The techniques for releasing thermal energy accumulated in periods of high availability to meet the demand in periods of low energy supply contribute to the continuity of the cycles involved in thermodynamic processes. In this context, phase change materials are capable of absorbing and releasing large amounts of energy in relatively short periods of time and under specific operating conditions. However, phase change materials have low thermal conductivity and need to be coupled with high-thermal-conductivity materials so that the heat flux can be intensified and the energy absorption and release times can be controlled. This work aims to numerically study the solidification process of a phase change material inserted into a triplex tube heat exchanger with finned copper walls to intensify the thermal exchange between the phase change material and the cooling heat transfer fluid, water, that will receive the energy accumulated in the material. This work proposes the 3D numerical modeling of the triplex tube heat exchanger with finned walls and meets the need for numerical models that allow for the analysis of the full geometry of the latent heat thermal energy storage system and the thermal and fluid dynamic phenomena that are influenced by this geometry. Results of the temperature, liquid fractions and velocity fields during phase transformations are presented, analyzed and validated with experimental data, presenting average errors of below 5%. The total material discharge time was approximately 168 min, necessary for the complete solidification of the phase change material, with water injected into the triplex tube heat exchanger at a flow rate of 8.3 L/min and a temperature of 68 °C. The solidification process occurred more slowly in the same direction as the length of the triplex tube heat exchanger, and from 80% of the material in the solid state, the difference between the solidification time for z = 0 and z = 480 mm was 30 min. The fluid dynamic conditions developed in the latent heat thermal energy storage system promoted a maximum negative heat flux of −6423 w/m2 to the annular internal surface and −742 w/m2 to the annular external surface, representing a heat removal process nine times less intense on the external surface. The total energy released to the cooling heat transfer fluid was 239.56 kJ/kg.
Energy Harvesting Technologies and Devices from Vehicular Transit and Natural Sources on Roads for a Sustainable Transport: State-of-the-Art Analysis and Commercial Solutions
Authors: De Fazio Roberto , De Giorgi Mariangela , Cafagna Donato , Del-Valle-Soto Carolina , Visconti Paolo
Published: March 2023

The roads we travel daily are exposed to several energy sources (mechanical load, solar radiation, heat, air movement, etc.), which can be exploited to make common systems and apparatus for roadways (i.e., lighting, video surveillance, and traffic monitoring systems) energetically autonomous. For decades, research groups have developed many technologies able to scavenge energy from the said sources related to roadways: electromagnetism, piezoelectric and triboelectric harvesters for the cars’ stress and vibrations, photovoltaic modules for sunlight, thermoelectric solutions and pyroelectric materials for heat and wind turbines optimized for low-speed winds, such as the ones produced by moving vehicles. Thus, this paper explores the existing technologies for scavenging energy from sources available on roadways, both natural and related to vehicular transit. At first, to contextualize them within the application scenario, the available energy sources and transduction mechanisms were identified and described, arguing the main requirements that must be considered for developing harvesters applicable on roadways. Afterward, an overview of energy harvesting solutions presented in the scientific literature to recover energy from roadways is introduced, classifying them according to the transduction method (i.e., piezoelectric, triboelectric, electromagnetic, photovoltaic, etc.) and proposed system architecture. Later, a survey of commercial systems available on the market for scavenging energy from roadways is introduced, focusing on their architecture, performance, and installation methods. Lastly, comparative analyses are offered for each device category (i.e., scientific works and commercial products), providing insights to identify the most promising solutions and technologies for developing future self-sustainable smart roads.
Energy Management Strategies for Hybrid Loaders: Classification, Comparison and Prospect
Authors: Liu Jichao , Liang Yanyan , Chen Zheng , Chen Wenpeng
Published: March 2023

As one of the effective and crucial ways to achieve the energy saving and emission reduction of loaders, hybrid technology has attracted the attention of many scholars and manufacturers. Selecting an appropriate energy management strategy (EMS) is essential to reduce fuel consumption and emissions for hybrid loaders (HLs). In this paper, firstly, the application status of drivetrain configuration of HLs is presented. Then, the working condition characteristics of loaders are analyzed. On the basis of this, the configurations of HLs are classified, and the features and research status of each configuration are described. Next, taking the energy consumption optimization of HLs as the object, the implementation principle and research progress of the proposed rule strategy and optimization strategy are compared and analyzed, and the differences of existing EMSs and future development challenges are summarized. Finally, combining the advantages of intelligent control and optimal control, the future prospective development direction of EMSs for HLs is considered. The conclusions of the paper can be identified in two points: firstly, although the existing EMSs can effectively optimize the energy consumption of HLs, the dependence of the strategy on the mechanism model and the vehicle parameters can reduce the applicability of the strategy to heterogeneous HLs and the robustness to a complex working condition. Secondly, combining the advantages of intelligent control and optimal control, designing an intelligent EMS not depending on the vehicle analytical model will provide a new method for solving the energy consumption optimization problem of HL.
Tritium Extraction from Lithium–Lead Eutectic Alloy: Experimental Characterization of a Permeator against Vacuum Mock-Up at 450 °C
Authors: Papa Francesca , Venturini Alessandro , Martelli Daniele , Utili Marco
Published: March 2023

Tritium extraction is one of the key open issues toward the development of the WCLL BB (Water-Cooled Lithium–Lead Breeding Blanket) of EU DEMO reactors, and different technologies have been proposed to address it. Among them, the Permeator Against Vacuum (PAV) has promising features, but it has never been tested in a relevant environment. This work presents the first experimental results ever obtained for a PAV mock-up. The experiments were carried out at ENEA Brasimone R.C. with the TRIEX-II facility on a mock-up characterized by a shell and tube configuration and using niobium as a membrane material. The experimental campaign was carried out with LiPb flowing at about 450 °C and 1.2 kg/s, while the hydrogen partial pressure was varied in the range 170–360 Pa. The characterization of the PAV performance was conducted by measuring the hydrogen partial pressure drop across the mock-up and the hydrogen permeated flux through a leak detector calibrated with an external hydrogen calibration cylinder. Moreover, the permeated flux was confirmed by a pressurization test performed measuring the pressure increase on the vacuum side of the PAV. The results constitute the first verification of the possibility to operate a PAV in flowing LiPb and to quantify its capabilities.
Intelligent Forecasting and Optimization in Electrical Power Systems: Advances in Models and Applications
Authors: Dudek Grzegorz , Piotrowski Paweł , Baczyński Dariusz
Published: March 2023

A modern power system is a complex network of interconnected components, such as generators, transmission lines, and distribution subsystems, that are designed to provide electricity to consumers in an efficient and reliable manner [...]
New Advancements in Heat and Mass Transfer: Fundamentals and Applications
Authors: Yu Guojun , Liu Huihao , Xu Huijin
Published: March 2023

Heat and mass transfer, widely involved in various energy systems, has great impacts on the safety, efficiency, as well as performance of these systems [...]
DC Transformers in DC Distribution Systems
Authors: Chen Yangfan , Zhang Yu
Published: March 2023

With the rapid development of power electronics technology and its successful application, many demonstration projects of medium/low-voltage DC (M-LVDC) distribution systems have been constructed. The DC transformer (DCT) is the key equipment in the M-LVDC distribution system for interconnecting the MVDC and LVDC buses. In this paper, the characteristics of DCTs are summarized. The existing topologies of DCTs are analyzed, and the relevant control strategies are researched, including steady-state control, transient control, and cascaded control. The engineering application examples of DCTs are introduced by interpreting the medium and low-voltage DC distribution system demonstration project in Wujiang City, Suzhou. Finally, the challenges faced by the DCT are given, and the future development trend is predicted. This perspective provides a constructive basis for DCTs and an important reference for M-LVDC distribution systems.
Review: Heterojunction Tandem Solar Cells on Si-Based Metal Oxides
Authors: Fara Laurentiu , Chilibon Irinela , Craciunescu Dan , Diaconu Alexandru , Fara Silvian
Published: March 2023

PV technology offers a sustainable solution to the increased energy demand especially based on mono- and polycrystalline silicon solar cells. The most recent years have allowed the successful development of perovskite and tandem heterojunction Si-based solar cells with energy conversion efficiency over 28%. The metal oxide heterojunction tandem solar cells have a great potential application in the future photovoltaic field. Cu2O (band gap of 2.07 eV) and ZnO (band gap of 3.3 eV) are very good materials for solar cells and their features completely justify the high interest for the research of tandem heterojunction based on them. This review article analyzes high-efficiency silicon-based tandem heterojunction solar cells (HTSCs) with metal oxides. It is structured on six chapters dedicated to four main issues: (1) fabrication techniques and device architecture; (2) characterization of Cu2O and ZnO layers; (3) numerical modelling of Cu2O/ZnO HTSC; (4) stability and reliability approach. The device architecture establishes that the HTSC is constituted from two sub-cells: ZnO/Cu2O and c-Si. The four terminal tandem solar cells contribute to the increased current density and conversion efficiency. Cu2O and ZnO materials are defined as promising candidates for high-efficiency solar devices due to the morphological, structural, and optical characterization emphasized. Based on multiscale modelling of PV technology, the electrical and optical numerical modelling of the two sub-cells of HTSC are presented. At the same time, the thermal stability and reliability approach are essential and needed for an optimum operation of HTSC, concerning the cell lifetime and degradation degree. Further progress on flexible HTSC could determine that such advanced solar devices would become commercially sustainable in the near future.
Enhancing User Engagement in Local Energy Initiatives Using Smart Local Energy Engagement Tools: A Meta Study
Authors: Gupta Rajat , Zahiri Sahar , Morey Johanna
Published: March 2023

Deploying smart local energy engagement tools (SLEETs) in local energy projects enables users to better observe and control energy, and potentially become active participants in local energy management. Using a cross-project approach, this paper examines the prevalence, effectiveness and inclusiveness of 84 SLEETs deployed in 72 local energy projects in the UK from 2008 to 2018. An original framework for the characterisation of SLEETs was employed, which grouped them into seven types and characterised them in terms of their level of interaction and interface design. Our study shows that information-driven tools were the most popular in community energy groups, while digital energy platforms or interaction tools with numeric interfaces were the most popular in smart local energy system (SLES) initiatives. In contrast, interaction tools with visual interfaces, and tools offering control were found to be less popular. Spatial analysis revealed that SLEETs were mostly deployed in areas with grid constraints (technology), active community energy groups (people) and engaged local authorities (policy). Effective SLEETs were found to stimulate engagement amongst people (social engagement), and between people and technology (operation and control), while inclusive SLEETs enabled the inclusion of vulnerable and low-income households. The acceptance and implementation of SLES initiatives can be enhanced by creating effective and inclusive SLEETs that align with local users’ requirements and are supported by local stakeholders in order to foster trust. In future, there is a need to develop appropriate metrics (key performance indicator) or scoring methods to measure the prevalence, effectiveness, and inclusiveness of SLEETs in a consistent manner.
Acceleration-Insensitive Pressure Sensor for Aerodynamic Analysis
Authors: Szczerba Zygmunt , Szczerba Piotr , Szczerba Kamil , Pytel Krzysztof
Published: March 2023

This paper presents a method for preparing a pressure sensor that is insensitive to acceleration along with experimental evidence of its efficacy in aerodynamic analysis. A literature review and preliminary studies revealed the undesirable effect of acceleration on sensors that are located on moving elements, as evidenced by deviations from actual pressure values for piezoresistive pressure sensors that are made using MEMS technology. To address this, the authors developed a double-membrane sensor geometry that eliminated this imperfection; a method of implementing two solo pressure sensors as a new geometry-designed sensor was also proposed. Experimental tests of this suggested solution were conducted; these measurements are presented here. The results indicated that this new sensor concept could be used to measure the dynamic pressures of rotating and moving objects in order to obtain measurement results that are more reliable and closer to the true values that are derived from aerodynamic analyses. The published results confirm the reliability of the proposed device.
Directional Dependency of Relative Permeability in Vugular Porous Medium: Experiment and Numerical Simulation
Authors: Song Shihan , Di Yuan , Guo Wanjiang
Published: March 2023

Carbonate reservoirs are a highly heterogeneous type of reservoir characterized by the presence of a large amount of vugs and pores. During two-phase displacement, the two-phase flow regime in the vugs might be gravity segregated. The distribution pattern of two-phase fluid in the vugs would accelerate the water flow in downward and horizontal directions, meanwhile decelerating in an upward direction, resulting in a different oil recovery ratio. This gives rise to the question of whether the relative permeability should be modeled as a directional dependent in a vugular porous medium since it is usually treated as an isotropic quantity. In this study, via both experiment and numerical simulation, we demonstrate that the relative permeability of vugular porous medium is dependent on the angle between the flow direction and the horizontal plane and should be considered for oil recovery estimation for carbonate reservoirs. Using the transmissibility-weighted upscaling method and a single-vug model, the relative permeability curves for different flow directions are obtained by numerical simulation. A directional relative permeability model for a vugular porous medium is also proposed.
Production of Low-Mercury Solid Fuel by Mild Pyrolysis Process
Authors: Dziok Tadeusz
Published: March 2023

Mercury is considered one of the most harmful ecotoxic elements. A main source of its anthropogenic emissions is fuel combustion. For fuels with a high mercury content, costly methods are required to remove mercury from the flue gases. The solution to this problem is to remove mercury from the fuel before combustion. This can be achieved by a mild pyrolysis process. Solid fuel samples with relatively high mercury content were examined. These included waste (refuse-derived fuel, paper, sewage sludge, and rubber), waste wood biomass (hornbeam leaves, pine and spruce bark), and six coal. The mild pyrolysis process was performed at 300 °C in an argon flow of 500 cm3/min. The residence time was 30 min. Proximate and ultimate analysis (including mercury content) was conducted for raw fuels and chars. The process allowed a significant reduction in mercury content from 36 to 97%. Mercury was most easily removed from biomass and waste with the most difficult being from coal. The effectiveness of mercury removal was determined by the type of fuel and its mercury content. The mercury content in the obtained chars was 0.05–3.4 µg Hg/MJ. The use of such chars will meet current EU emission standards and those to be introduced in the future.
New Electrogenic Microorganism Citrobacter sp. Isolated from Microbial Fuel Cell and Bacterial Characteristics Determination
Authors: Jimenez Pacheco Hugo Guillermo , Portocarrero Banda Abdel Alejandro , Vilca Cayllahua Eric Ivan , Miranda Ramos Lilia Mary , Alvarez Tohalino Victor Ludgardo , Del Carpio Beltran Herbert Jesús , Delgado Sarmiento Pavel Kewin
Published: March 2023

The generation of energy through the transformation of polluting waste is a widely explored field and offers advances in green technologies. One of the promising technologies is Microbial Fuel Cells (MFCs). These cells can contain electroactive microorganisms that transform organic waste into electricity by transferring electrons from their metabolism. In this study, a new bacterium capable of producing electricity from the waste of the poultry sector and using copper electrodes, called Av_G1, was identified and isolated. It is phylogenetically related to Citrobacter freundii and Citrobacter Murlinae. This new strain was identified molecularly, biochemically, and phylogenetically; its physiological and morphological characteristics were also studied through a Scanning Electron Microscope (SEM). Biochemical determination was performed using Simmons Citrate Agar, Lysine Iron Medium (L.I.A.), Motility/Ornithine Test, Methyl Red indicator, Enzymes: oxidase and catalase, and Gram stain test. The phylogenetic inference was deduced by bioinformatics tools (MEGA X, JalView, Clustal Omega) and the genetic databases The Ribosomal Database Project—RDP and the National Center for Biotechnology Information (NCBI). A maximum current potential of 0.645 V, a maximum current density of 168.72 ± 14.07 mA/m2, and a power density of 31.05 mW/m2 were recorded. During the monitoring, the physicochemical parameters were taken: pH, Oxide Reduction Potential (ORP), Dissolved Oxygen (DO), conductivity, Total Solids (TDS), and average temperature were recorded. Therefore, the present study shows a new Gram-negative electrogenic bacterium, which can be used for electrochemical processes and applied in MFC with copper electrodes.
Reversible Impacts of a Cold Spell on Forest Cover, Tree Growth and Carbohydrates in Mediterranean Pine and Oak Forests
Authors: Camarero Jesús Julio , Colangelo Michele , Valeriano Cristina , Pizarro Manuel
Published: March 2023

Climate extremes such as cold spells are becoming more frequent as climate variability increases. However, few studies have evaluated the impacts of winter cold spells on forest cover, tree growth and leaf and sapwood non-structural carbohydrate (NSC) concentrations. We analyzed changes in tree cover using remote sensing data and compared the radial growth of coexisting and defoliated Pinus halepensis trees and non-defoliated P. halepensis and Pinus pinaster trees. We also compared NSC concentrations in leaves and sapwood of defoliated and non-defoliated P. halepensis and Quercus ilex trees. In January 2021, a rapid drop in temperatures led to minimum values (−21.3 °C) in eastern Spain and triggered canopy defoliation in several planted (P. halepensis) and native (Q. ilex) tree species. The cold spell led to a decrease in forest cover in the most defoliated stands and reduced radial growth of defoliated P. halepensis and sapwood NSC concentrations in P. halepensis and Q. ilex, particularly starch. Prior to the cold spell, defoliated P. halepensis trees significantly (p < 0.05) grew more (2.73 ± 1.70 mm) in response to wetter winter conditions than non-defoliated P. halepensis (2.29 ± 1.08 mm) and P. pinaster (1.39 mm) trees. Those P. halepensis individuals which grew faster at a young age were less resilient to the winter cold spell in later years. The study stands showed a high recovery capacity after the cold spell, but the Mediterranean drought-avoiding P. halepensis was the most affected species.
A Deep Learning Approach to Detect Failures in Bridges Based on the Coherence of Signals
Authors: Bono Francesco Morgan , Radicioni Luca , Cinquemani Simone , Benedetti Lorenzo , Cazzulani Gabriele , Somaschini Claudio , Belloli Marco
Published: March 2023

Structural health monitoring of civil infrastructure, such as bridges and buildings, has become a trending topic in the last few years. The key factor is the technological push given by new technologies that permit the acquisition, storage, processing and visualisation of data in real time, thus assessing a structure’s health condition. However, data related to anomaly conditions are difficult to retrieve, and, by the time those conditions are met, in general, it is too late. For this reason, the problem becomes unsupervised, since no labelled data are available, and anomaly detection algorithms are usually adopted in this context. This research proposes a novel algorithm that transforms the intrinsically unsupervised problem into a supervised one for condition monitoring purposes. Considering a bridge equipped with N sensors, which measure static structural quantities (rotations of the piers) and environmental parameters, exploiting the relationships between different physical variables and determining how these relationships change over time can indicate the bridge’s health status. In particular, this algorithm involves the training of N models, each of them able to estimate the quantity measured via a sensor by using the others’ N−1 measurements. Hence, the system can be represented by the ensemble of the N models. In this way, for each sensor, it is possible to compare the real measurement with the predicted one and evaluate the residual between the two; this difference can be addressed as a symptom of changes in the structure with respect to the condition regarded as nominal. This approach is applied to a real test case, i.e., Candia Bridge in Italy, and it is compared with a state-of-the-art anomaly detector (namely an autoencoder) in order to validate its robustness.
Insights into How Vietnamese Retailers Utilize Social Media to Facilitate Knowledge Creation through the Process of Value Co-Creation
Authors: Trim Peter R. J. , Lee Yang-Im , Vu An
Published: March 2023

Social media usage is a direct result of Internet connectivity and is gaining increased prominence in business-to-consumer (B2C), business-to-business (B2B), and consumer-to-business (C2B) relationship building, which is allowing marketers to devise and implement digital marketing strategies that are perceived as enhancing a customer’s well-being. Through the process of utilizing social media (SM) to share information with consumers, marketers are affording themselves with the concept of value co-creation and ensuring that the development of knowledge is given priority. To explain how this happens in an emerging economy, in-depth personal interviews were undertaken with the owners of five retail fashion companies in Vietnam. The findings indicate that fashion retail companies in Vietnam are deploying digital marketing strategies that deliver perceived enhanced value to consumers through the process of value co-creation. This highlights the advantage of using SM in relation to increasing retail staff’s ability to convert information into usable resources such as intelligence and knowledge. By achieving knowledge conversion, retail staff fulfill the role of ‘knowledge broker’ and ‘knowledge connector’, and identify how organizational intervention, such as new operating structures, can help to deliver perceived enhanced value to customers.
Developing a Virtual World for an Open-House Event: A Metaverse Approach
Authors: Samarnggoon Keattikorn , Grudpan Supara , Wongta Noppon , Klaynak Konlawat
Published: March 2023

The concept of a metaverse, a virtual world that offers immersive experiences, has gained widespread interest in recent years. Despite the hype, there is still a gap in its practical application, especially in the realm of education. This study presents the design and implementation of a metaverse tailored to the needs of education. The goal of this paper is to demonstrate the feasibility of such a system and evaluate its effectiveness. It is crucial to understand the architecture and implementation of a metaverse to effectively customise it for educational purposes. To assess user experience, a field study was conducted, collecting data through questionnaires and qualitative feedback. The results show that users were pleased with the features, player experience, and ease of use.
Market Crashes and Time-Translation Invariance
Authors: Gluzman Simon
Published: March 2023

The general framework for quantitative technical analysis of market prices is revisited and extended. The concept of a global time-translation invariance and its spontaneous violation and restoration is introduced and discussed. We find that different temporal patterns leading to some famous crashes (e.g., bubbles, hockey sticks, etc.) exhibit analogous probabilistic distributions found only in the time series for the stock market indices. A number of examples of crashes are presented. We stress that our goal here is to study the crash as a particular phenomenon created by spontaneous time-translation symmetry breaking/restoration. We ask only “how to calculate and interpret the probabilistic pattern which we encounter in the day preceding crash, and how to calculate the typical market reactions to shock?”.
Physico-Chemical Study of Curcumin and Its Application in O/W/O Multiple Emulsion
Authors: Opustilová Kristýna , Lapčíková Barbora , Lapčík Lubomír , Gautam Shweta , Valenta Tomáš , Li Peng
Published: March 2023

Curcuma is a world-renowned herb known for its immense health benefits. In this study, physicochemical analyses were performed on the curcumin standard sample and curcumin multiple emulsions. The emulsions were analysed for thermal and structural stability for 21 days. Confocal laser microscopy (CLSM) was performed in order to observe the emulsion encapsulation. Modulated differential scanning calorimetry (MDSC) and HPLC methods revealed a variety of curcuminoids (curcumin, demethoxycurcumin, bisdemethoxycurcumin, and cyclocurcumin) in the investigated curcumin standard. In addition, the MDSC method was found to be suitable and comparable to HPLC for determining the curcuminoid substances. The analysis of the curcumin release revealed a value of 0.18 w.% after 14 days as the equilibrium value. Furthermore, an increase in the sizes of the emulsions was observed at the end of the 21-day study. The emulsion stability index (ESI) was used to measure the stability of multiple emulsions. The ESI reached 55.8% between 7 and 21 days later. Nano droplets of the oil phase loaded with dispersed curcumin particles captured inside the water-based carboxymethylcellulose micelles were clearly observed by CLSM.
Effect of Sodium Hyaluronate on Antioxidant and Anti-Ageing Activities in Caenorhabditis elegans
Authors: Lin Qianmin , Song Bingbing , Zhong Yingxiong , Yin Huan , Li Ziyu , Wang Zhuo , Cheong Kit-Leong , Huang Riming , Zhong Saiyi
Published: March 2023

As an acidic polysaccharide, the formation of Hyaluronic acid (HA) is typically Sodium Hyaluronate (SH) for knee repair, oral treatment, skincare and as a food additive. Nevertheless, little information is available on the anti-ageing activity of SH as a food additive. Therefore, we treated C. elegans with SH, then inferred the anti-aging activity of SH by examining the lifespan physiological indicators and senescence-associated gene expression. Compared with the control group, SH (800 μg/mL) prolonged the C. elegans’ lifespans in regular, 35 °C and H2O2 environment by 0.27-fold, 0.25-fold and 1.17-fold. Simultaneously, glutathione peroxidase (GSH-Px), antioxidant enzyme superoxide dismutase (SOD) and catalase (CAT) were increased by 8.6%, 0.36% and 167%. However, lipofuscin accumulation, reactive oxygen species (ROS) and malondialdehyde (MDA) were decreased by 36%, 47.8–65.7% and 9.5–13.1%. After SH treatment, athletic ability was improved and no impairment of reproductive capacity was seen. In addition, SH inhibited the blocking effect of age-1 and up-regulated gene levels involving daf-16, sod-3, gst-4 and skn-1. In conclusion, SH provides potential applications in anti-ageing and anti-oxidation and regulates physiological function.
Determination by ICP-MS of Essential and Toxic Trace Elements in Gums and Carrageenans Used as Food Additives Commercially Available in the Portuguese Market
Authors: Azevedo Rui , Oliveira Ana , Almeida Agostinho , Gomes Lígia
Published: March 2023

Gums and carrageenans are food additives widely used in food preparations to improve texture and as viscosifiers. Although they are typically added in small amounts, nowadays people tend to use more and more pre-prepared food. In this work, the content of a wide panel of trace elements in commercial products were analyzed. Carrageenans and gums (n = 13) were purchased in the Portuguese market and were from European suppliers. Samples were solubilized by closed-vessel microwave-assisted acid digestion and analyzed by ICP-MS. Globally, the content of essential trace elements decreased in the following order: Fe (on average, on the order of several tens of µg/g) > Mn > Zn > Cr > Cu > Co > Se > Mo (typically < 0.1 µg/g), while the content of non-essential/toxic trace elements decreased in the following order: Al > Sr > Rb > As > Li > Cd > Pb > Hg. The consumption of these food additives can significantly contribute to the daily requirements of some essential trace elements, namely Cr and Mo. The toxic trace elements Cd, As, Pb, and Hg were below the EU regulatory limits in all analyzed samples. Additional research is needed to define the potential risk of introducing toxic trace elements into food products through the use of these additives.
Comparison of Physico-Chemical Properties, Phytochemical Compositions and Sensory Characteristics of Wheat Breads Enriched with Coriander Seed Powder
Authors: Özcan Mehmet Musa
Published: March 2023

In this study, the physico-chemical properties, polyphenol and fatty acid profiles and sensory evaluations of breads made from wheat flour and coriander seed powder mixtures were investigated. The oil yields of breads with coriander were identified between 0.11% (control) and 1.25% (with 30% coriander). The highest and lowest L* values were observed in the control and bread with 30% added coriander, respectively. The addition of coriander caused an increase in a* and b* (except for the bread with 30% added coriander) values of breads. Total phenol and flavonoid values of the coriander bread samples were recorded between 43.13 (control) and 64.01 mg GAE/100 g (with 30% coriander) to 72.62 (control) and 130.71 mg/100 g (with 30% coriander), respectively. The antioxidant capacity values of breads produced by adding coriander at different levels were determined between 0.45 (control) and 1.32 mmol/kg (with 30% coriander). In general, the quantitative values of phenolic constituents of the bread samples with added coriander powder were low compared to the control (except catechin and rutin). Gallic acid, 3,4-dihydroxybenzoic acid, catechin and rutin were found at the highest amounts in bread samples, followed by caffeic acid, syringic acid and p-coumaric acids in descending order. Gallic acid and 3,4-dihydroxybenzoic acid amount values of bread samples were between 11.51 mg/100 g (with 30% coriander) and 45.21 (control), and 16.41 mg/100 g (with 10% coriander) and 29.39 mg/100 g (with 20% coriander), respectively. Additionally, the catechin and rutin contents of wheat breads produced by adding coriander seed powder at different concentrations were between 37.43 (with 10% coriander) and 70.12 mg/100 g (with 20% coriander), and 6.76 mg/100 g (with 10% coriander) and 29.45 mg/100 g (with 30% coriander powder), respectively. The phenolic components of the breads gradually decreased in parallel with the increase in the coriander concentration. The oleic and linoleic acid results of the oils of bread samples produced by adding coriander seed powder were between 23.15% (control) and 62.45% (with 30% coriander), and 26.67% (with 30% coriander) and 52.20% (control), respectively. In addition, with the increase in coriander concentration, the increase in the oleic acid contents of bread oils compared to the control and the decrease in the linoleic acid result gave the bread functionality for human health. In general, among the coriander bread samples, the bread sample with a 30% concentration of coriander powder was the most appreciated.
Evaluation of Preharvest Melatonin on Soft Rot and Quality of Kiwifruit Based on Principal Component Analysis
Authors: Peng Junsen , Zhu Shouliang , Lin Xin , Wan Xuan , Zhang Qin , Njie Alagie , Luo Dengcan , Long Youhua , Fan Rong , Dong Xiaoqing
Published: March 2023

Botryosphaeria dothidea is the source of the deadly kiwifruit disease known as soft rot. In order to explore the role of melatonin in regulating the postharvest quality and disease resistance of kiwifruit at different growth and development stages, in this study, we applied melatonin at different concentrations to kiwifruit at the young fruit, expansion, and late expansion stages to assess its effect on fruit resistance to B. dothidea, minimize soft rot, and maintain postharvest fruit quality. The results showed that melatonin significantly suppressed the mycelial growth of B. dothidea, with 1.0 mmol/L melatonin inhibiting it by up to 50%. However, 0.1–0.3 mmol/L melatonin had the best control over soft rot. Furthermore, spraying MT during kiwifruit growth can successfully increase fruit weight; preserve postharvest fruit firmness; reduce respiration intensity in the early stages of storage; delay the rise in soluble solids, while maintaining a high titratable acid content to ensure suitable solid acid ratio; increase total phenol, flavonoid, chlorophyll, carotenoid, and ascorbic acid contents; and delay the rise in soluble sugar contents in the late stages of storage. These results have a positive effect on maintaining the nutritional composition of kiwifruit. However, the effects on weight loss, dry matter content, and soluble protein content were not significant. In addition, the results of the principal component analysis demonstrated that 0.3 mmol/L MT increased kiwifruit’s resistance to soft rot while preserving postharvest fruit quality.
Gene-by-Sex Interactions: Genome-Wide Association Study Reveals Five SNPs Associated with Obesity and Overweight in a Male Population
Authors: Kyrgiafini Maria-Anna , Sarafidou Theologia , Giannoulis Themistoklis , Chatziparasidou Alexia , Christoforidis Nikolaos , Mamuris Zissis
Published: March 2023

Obesity is a chronic health problem associated with severe complications and with an increasing prevalence in the Western world. Body-fat composition and distribution are closely associated with obesity, but the human body’s composition is a sexually dimorphic trait, as differences between the two sexes are evident even from fetal life. The effect of sex hormones contributes to this phenomenon. However, studies investigating gene-by-sex interactions for obesity are limited. Therefore, the aim of the present study was to identify single-nucleotide polymorphisms (SNPs) associated with obesity and overweight in a male population. A genome-wide association study (GWAS) that included 104 control, 125 overweight, and 61 obese subjects revealed four SNPs associated with overweight (rs7818910, rs7863750, rs1554116, and rs7500401) and one SNP (rs114252547) associated with obesity in males. An in silico functional annotation was subsequently used to further investigate their role. Most of the SNPs were found in genes regulating energy metabolism and homeostasis, and some of them were expression quantitative trait loci (eQTL). These findings contribute to the understanding of the molecular mechanisms underlying obesity-related traits, especially in males, and pave the road for future research toward the improvement of the diagnosis and therapy of obese individuals.
Inverse Comorbidity between Down Syndrome and Solid Tumors: Insights from In Silico Analyses of Down Syndrome Critical Region Genes
Authors: Fosu Kwadwo , Quarshie Jude Tetteh , Sarpong Kwabena Amofa Nketia , Aikins Anastasia Rosebud
Published: March 2023

An inverse comorbidity has been observed between Down syndrome (DS) and solid tumors such as breast and lung cancers, and it is posited that the overexpression of genes within the Down Syndrome Critical Region (DSCR) of human chromosome 21 may account for this phenomenon. By analyzing publicly available DS mouse model transcriptomics data, we aimed to identify DSCR genes that may protect against human breast and lung cancers. Gene expression analyses with GEPIA2 and UALCAN showed that DSCR genes ETS2 and RCAN1 are significantly downregulated in breast and lung cancers, and their expression levels are higher in triple-negative compared to luminal and HER2-positive breast cancers. KM Plotter showed that low levels of ETS2 and RCAN1 are associated with poor survival outcomes in breast and lung cancers. Correlation analyses using OncoDB revealed that both genes are positively correlated in breast and lung cancers, suggesting that they are co-expressed and perhaps have complementary functions. Functional enrichment analyses using LinkedOmics also demonstrated that ETS2 and RCAN1 expression correlates with T-cell receptor signaling, regulation of immunological synapses, TGF-β signaling, EGFR signaling, IFN-γ signaling, TNF signaling, angiogenesis, and the p53 pathway. Altogether, ETS2 and RCAN1 may be essential for the development of breast and lung cancers. Experimental validation of their biological functions may further unravel their roles in DS and breast and lung cancers.
Association of Multiple Cardiovascular Risk Factors with Musculoskeletal Function in Acute Coronary Syndrome Ward Inpatients
Authors: Parisotto Gabriel , Reis Luis Felipe Fonseca , Junior Mauricio Sant’Anna , Papathanasiou Jannis , Lopes Agnaldo José , Ferreira Arthur Sá
Published: March 2023

This study explored the association of multiple risk factors with musculoskeletal function in adults hospitalized for acute coronary syndrome. Sixty-nine inpatients (55 ± 6 years; 67% male) admitted to the cardiology ward within <12 h were assessed regarding stress, smoking, alcoholism, hypertension, diabetes mellitus, and obesity. The musculoskeletal function was assessed by predicted values of handgrip strength of the dominant hand (HGS-D%) and maximal inspiratory and expiratory pressures (MIP% and MEP%, respectively). After adjustment by age and sex, drinking habits showed the strongest linear association with the total number of cardiovascular disease risk factors [standardized ß, p-value] (ß = 0.110, p < 0.001), followed by smoking load (ß = 0.028, p = 0.009). Associations were also observed for HGS-D% with mean blood pressure (ß = 0.019 [0.001; 0.037], p = 0.048); MIP% with mean blood pressure (ß = 0.025 [0.006; 0.043], p = 0.013); and MEP% with drinking habits (ß = 0.009 [0.002; 0.016], p = 0.013) and body mass index (ß = 0.008 [0.000; 0.015], p = 0.035). Peripheral and respiratory muscle strength must be interpreted in the context of its association with cardiovascular disease risk factors in adults hospitalized for acute coronary syndrome.
Doctors’ Professional and Personal Reflections: A Qualitative Exploration of Physicians’ Views and Coping during the COVID-19 Pandemic
Authors: Adams G. Camelia , Reboe-Benjamin Monique , Alaverdashvili Mariam , Le Thuy , Adams Stephen
Published: March 2023

Numerous studies have examined the risks for anxiety and depression experienced by physicians during the COVID-19 pandemic. Still, qualitative studies investigating physicians’ views, and their discovered strengths, are lacking. Our research fills this gap by exploring professional and personal reflections developed by physicians from various specialties during the pandemic. Semi-structured interviews were conducted with physicians practicing in the province of Saskatchewan, Canada, during November 2020–July 2021. Thematic analysis identified core themes and subthemes. Seventeen physicians, including nine males and eight females, from eleven specialties completed the interviews. The pandemic brought to the forefront life’s temporality and a new appreciation for life, work, and each other. Most physicians found strength in values, such as gratitude, solidarity, and faith in human potential, to anchor them professionally and personally. A new need for personal fulfilment and hybrid care emerged. Negative feelings of anger, fear, uncertainty, and frustration were due to overwhelming pressures, while feelings of injustice and betrayal were caused by human or system failures. The physicians’ appreciation for life and family and their faith in humanity and science were the primary coping strategies used to build adaptation and overcome negative emotions. These reflections are summarized, and implications for prevention and resilience are discussed.