bluuebunny/crossref_metadata_2025 huggingface dataset:
Calculation and Management of Water Supply and Demand under Land Use/Cover Changes in the Yarmouk River Basin Governorates in Jordan
Authors: Shammout Maisa’a W.
Published: July 2023

This paper presents the calculation and management of water supply and demand under land use/cover changes in the Yarmouk River Basin in Jordan for the years 1997, 2007 and 2017. It aims to analyze and link the changes in the land classes with the water resources supply demand as the groundwater is unable to meet the inhabitants demand, necessitating land management practices. The method includes deriving land use/cover maps using the supervised classification, identifying basin governorates, cities and villages, calculating the basin governorates’ inhabitants, water demand, supply of internal wells, water loss, and actual water consumption. The results showed an increase in the urban area by 3.01%, while forests, rain-fed vegetables and crops declined by 1.57% and 1.09%, respectively. Urbanization appears mainly at the expense of rangelands, an important change affecting water supply from internal wells due to increased pumping to balance population demand. Although it is decreasing per capita, the water demand is high. Changing land use practices, securing inter-basin water resources, and calculating water losses is a challenge of great importance that can manage water shortages and increase actual consumption. This research is important in order to understand the supply demand situation and to aid a wide range of users, water-managers, land-planners and decision-makers.
Forest in Mozambique: Actual Distribution of Tree Species and Potential Threats
Authors: Joaquim-Meque Eugénia , Lousada José , Liberato Margarida L. R. , Fonseca Teresa F.
Published: July 2023

In recent decades, there has been a perception that the Mozambican forests have been threatened with massive exploitation for commercialization, deforesting vast areas, leading to desertification and contributing to the extinction of some forest species. The present research summarizes the official information obtained by monitoring the country’s natural resources over time and identifying the major types of existing forests in Mozambique. The main objective is to elucidate on the current state of Mozambican forests, analyze change and trends, and characterize the actual distribution of forest species in Mozambique to verify the sustainability of forest resources and their composition. It is a case study of the qualitative descriptive type, with data obtained through a bibliographic research method focusing on scientific articles on the type of forest species existing in Africa and Mozambique and data from official sources of the forests. Various types of forests were identified, such as mopane, mercrusse, semi-deciduous, miombo, and semi-evergreen, including the gallery forest. Forest species with particular relevance were highlighted, such as Afzelia quanzensis, Swartzia madagascariensis, Pterocarpaus angolensis, Combretum imberbe, and Millettia stuhalmannii. Major threats to these natural resources were identified and reported, including anthropogenic activity associated with traditional practices of illegal logging or due to the valuation of other goods of primary necessity, lack of protection and conservation measures, and impacts resulting from climate change. The Munza district is presented as a case study, carrying out a characterization of the forest in this district and identifying the main threats in the study area from 2015 to 2020.
Predicting Dominant Genotypes in Norovirus Seasons in Japan
Authors: Suzuki Yoshiyuki
Published: July 2023

Human noroviruses are an etiological agent of acute gastroenteritis. Since multiple genotypes co-circulate every season changing their proportions, it may be desirable to develop multivalent vaccines by formulating genotype composition of seed strains to match that of dominant strains. Here, performances of the models for predicting dominant genotypes, defined as the two most prevalent genotypes, were evaluated using observed genotype frequencies in Japan and genomic sequences for GI and GII strains. In the null model, genotype proportions in the target season were predicted to be the same as those in the immediately preceding season. In the fitness model, genotype proportions were predicted taking into account the acquisition of novel P-types through recombination and genotype-specific proliferation efficiency, as well as herd immunity to VP1 assuming the duration (d) of 0–10 years. The null model performed better in GII than in GI, apparently because dominant genotypes were more stable in the former than in the latter. Performance of the fitness model was similar to that of the null model irrespective of the assumed value of d. However, performance was improved when dominant genotypes were predicted as the union of those predicted with d = 0–10, suggesting that d may vary among individuals.
Sleep Disturbances in Panic Disorder with Comorbid Complex PTSD: A Possible Relationship and Different Psychopathology?
Authors: Carbone Elvira Anna , Menculini Giulia , de Filippis Renato , D’Angelo Martina , Zebi Leonardo , Steardo Luca
Published: July 2023

Background: Several studies have shown the possible link between trauma and sleep disturbances, particularly in anxiety disorders. This issue could be because sympathetic hyperarousal is central to both disorders, probably caused by a dysregulation of the noradrenergic system. This study aimed to establish if the comorbidity with complex post-traumatic stress disorder (cPTSD) is associated with sleep disturbances in panic disorder (PD) and if the presence of poor sleep quality is associated with a higher psychopathological burden. Methods: Participants (N = 211) with PD completed the International Trauma Questionnaire concerning their most troubling experience, the Hamilton Anxiety Rating Scale (HAM-A), and the Pittsburgh Sleep Quality Index (PSQI) to assess anxiety symptoms and sleep disturbances, respectively. Results: The sample was divided into two subgroups based on the presence of cPTSD. No significant differences emerged in the bivariate analyses for what concerns sociodemographic features. As for the scores of the psychopathological scales, the analysis highlighted statistically significant differences between the subgroups. Subjects with cPTSD reported significantly higher HAM-A total scores. As for the disturbances in self-organization (DSO) and PSQI scores, these were all significantly higher in the cPTSD subsample. At the logistic regression, the presence of cPTSD was inserted as the dependent variable, while the PSQI scores of the subscales evaluating subjective sleep quality, sleep duration, sleep efficacy, and the use of hypnotics were used as independent variables. The presence of cPTSD was significantly associated with the PSQI subscores for subjective sleep quality and use of hypnotics. Conclusions: Patients with PD exhibit more severe sleep disturbances and a higher anxiety burden when experiencing prolonged trauma. Therapeutic advances are needed in this field to target these symptomatologic domains.
Novel Biomarkers for Atherosclerotic Disease: Advances in Cardiovascular Risk Assessment
Authors: Jigoranu Raul-Alexandru , Roca Mihai , Costache Alexandru-Dan , Mitu Ovidiu , Oancea Alexandru-Florinel , Miftode Radu-Stefan , Haba Mihai Ștefan Cristian , Botnariu Eosefina Gina , Maștaleru Alexandra , Gavril Radu-Sebastian , Trandabat Bogdan-Andrei , Chirica Sabina Ioana , Haba Raluca Maria , Leon Maria Magdalena , Costache Irina-Iuliana , Mitu Florin
Published: July 2023

Atherosclerosis is a significant health concern with a growing incidence worldwide. It is directly linked to an increased cardiovascular risk and to major adverse cardiovascular events, such as acute coronary syndromes. In this review, we try to assess the potential diagnostic role of biomarkers in the early identification of patients susceptible to the development of atherosclerosis and other adverse cardiovascular events. We have collected publications concerning already established parameters, such as low-density lipoprotein cholesterol (LDL-C), as well as newer markers, e.g., apolipoprotein B (apoB) and the ratio between apoB and apoA. Additionally, given the inflammatory nature of the development of atherosclerosis, high-sensitivity c-reactive protein (hs-CRP) or interleukin-6 (IL-6) are also discussed. Additionally, newer publications on other emerging components linked to atherosclerosis were considered in the context of patient evaluation. Apart from the already in-use markers (e.g., LDL-C), emerging research highlights the potential of newer molecules in optimizing the diagnosis of atherosclerotic disease in earlier stages. After further studies, they might be fully implemented in the screening protocols.
Urine Parameters in Patients with COVID-19 Infection
Authors: Morello Maria , Amoroso Dominga , Losacco Felicia , Viscovo Marco , Pieri Massimo , Bernardini Sergio , Adorno Gaspare
Published: July 2023

A urine test permits the measure of several urinary markers. This is a non-invasive method for early monitoring of potential kidney damage. In COVID-19 patients, alterations of urinary markers were observed. This review aims to evaluate the utility of urinalysis in predicting the severity of COVID-19. A total of 68 articles obtained from PubMed studies reported that (i) the severity of disease was related to haematuria and proteinuria and that (ii) typical alterations of the urinary sediment were noticed in COVID-19-associated AKI patients. This review emphasizes that urinalysis and microscopic examination support clinicians in diagnosing and predicting COVID-19 severity.
The Roles of Coenzyme A Binding Pocket Residues in Short and Medium Chain Acyl-CoA Synthetases
Authors: Meng Yu , Ingram-Smith Cheryl , Ahmed Oly , Smith Kerry
Published: July 2023

Short- and medium-chain acyl-CoA synthetases catalyze similar two-step reactions in which acyl substrate and ATP bind to form an enzyme-bound acyl-adenylate, then CoA binds for formation of the acyl-CoA product. We investigated the roles of active site residues in CoA binding in acetyl-CoA synthetase (Acs) and a medium-chain acyl-CoA synthetase (Macs) that uses 2-methylbutyryl-CoA. Three highly conserved residues, Arg193, Arg528, and Arg586 of Methanothermobacter thermautotrophicus Acs (AcsMt), are predicted to form important interactions with the 5′- and 3′-phosphate groups of CoA. Kinetic characterization of AcsMt variants altered at each of these positions indicates these Arg residues play a critical role in CoA binding and catalysis. The predicted CoA binding site of Methanosarcina acetivorans Macs (MacsMa) is structurally more closely related to that of 4-chlorobenzoate:coenzyme A ligase (CBAL) than Acs. Alteration of MacsMa residues Tyr460, Arg490, Tyr525, and Tyr527, which correspond to CoA binding pocket residues in CBAL, strongly affected CoA binding and catalysis without substantially affecting acyl-adenylate formation. Both enzymes discriminate between 3′-dephospho-CoA and CoA, indicating interaction between the enzyme and the 3′-phosphate group is important. Alteration of MacsMa residues Lys461 and Lys519, located at positions equivalent to AcsMt Arg528 and Arg586, respectively, had only a moderate effect on CoA binding and catalysis. Overall, our results indicate the active site architecture in AcsMt and MacsMa differs even though these enzymes catalyze mechanistically similar reactions. The significance of this study is that we have delineated the active site architecture with respect to CoA binding and catalysis in this important enzyme superfamily.
Effects of Dietary Supplemental Chlorogenic Acid and Baicalin on the Growth Performance and Immunity of Broilers Challenged with Lipopolysaccharide
Authors: Lv Huiyuan , Li Peng , Wang Zhiming , Gao Mingkun , Li Guang , Nie Wei , Xiao Lei , Lv Zengpeng , Guo Yuming
Published: July 2023

The objective of this study was to investigate the effects of dietary supplemental chlorogenic acid and baicalin (CAB) on the growth performance and immunity of broilers challenged with lipopolysaccharide (LPS). This study was designed as a factorial arrangement of 2 dietary CAB treatments × 2 LPS treatments. Birds challenged with or without LPS were fed with a basic diet (CON) and (LPS), the level of CAB diet containing 500 mg/kg CAB(CAB) and (CAB + LPS). The feeding trial lasted for 42 days. Results showed that there was a negative effect on average daily weight gain (ADG) and average body weight of broilers during the animal trial with LPS challenge. The levels of diamine oxidase (DAO), lysozyme (LYZ), immunoglobulin G (IgG), and IgA in the serum, the contents of IL-1β and TNF-α in the spleen were elevated with LPS treated. Additionally, LPS treatment tended to reduce the jejunal villi height (VH) and total superoxide dismutase (T-SOD) in the serum. Dietary supplemental 500 mg/kg CAB increased the body weight and ADG and improved the feed conversion ratio (FCR) during the trial period. In addition, dietary 500 mg/kg CAB elevated the ratio of VH to crypt depth in the jejunum and reduced the content of protein carbonyl. Beyond that, the levels of IgG and IgA in the serum and transforming growth factor (TGF-β) in the spleen were up-regulated with 500 mg/kg CAB supplementation. In conclusion, dietary CAB was beneficial for growth performance and immunity of broilers challenged with lipopolysaccharide.
A Hydraulic Reciprocating Rod Seal’s Life Evaluation Method Incorporating Failure Mechanism Analysis and Test Observation Data
Authors: Duan Xiaochuan , Liu Di , Wang Shaoping , Shang Yaoxing
Published: July 2023

Reciprocating rod seals are widely used in hydraulic systems. Their useful life and reliability affect that of the system. Degradation modeling is necessary to evaluate the useful life of the seal. Seal wear is one of the important forms of hydraulic reciprocating rod seal degradation, yet it is difficult to measure through direct methods. Because seal wear determines the leakage of the seal, we therefore consider the seal leakage as the performance degradation index. Furthermore, the degradation of the seal is always associated with random effects, which cannot be considered by theoretical failure mechanism analysis. Hence, stochastic processes are applied to consider the random effects. Considering the error between the measured value and its real degradation state caused by the measurement environment or other factors, we introduce the measurement error term into the Wiener process model and develop the corresponding Wiener process life prediction model. Finally, the failure mechanism analysis and test measurement data are fused to predict the life cycle of the hydraulic reciprocating rod seals. The effectiveness of the proposed method is verified by comparing the predicted degradation and the experimental observations.
Analysis of the Load-Bearing Characteristics of Gas-Extruded Membrane Bearings Based on the Alternating Direction Implicit Method
Authors: Li Dongming , Wang Feng , Ma Ruize , Guo Weidong , Shan Ziyi , Zhao Kuipeng
Published: July 2023

In this study, a novel gas-extruded membrane bearing was developed, and an optimization algorithm was applied to solve a Reynolds equation that describes the load-bearing characteristics of this bearing. This was effective in improving the solution rate of the Reynolds equation, significantly reducing the difficulty of obtaining a solution, avoiding high programming difficulty, and achieving a high solution accuracy. Through a comparative analysis, the error in the accuracy of the alternating implicit difference method was addressed, and the traditional finite element method for solving the same model was verified, with an average error of 2% reached to verify its applicability. The algorithm was also used to analyze the load-bearing capacity of the gas-extruded membrane bearing. This revealed not only a positive correlation of the average load-bearing capacity of the gas-extruded membrane bearing with the frequency and amplitude of vibration but also a negative correlation with radial clearance, with the cut-off frequency reaching 19 Khz. The load-bearing capacity of the gas-extruded membrane bearing proposed in this paper reached 1.28 N, which indicated an error of 3.28% with the theoretical approach. To sum up, this research provides an important reference for the design and manufacture of novel gas-extruded membrane bearings.
Investigation on Tooth Surface Wear of Cycloid Drives Considering Tooth Profile Modifications
Authors: Li Xuan , Yang Haidong , Niu Weilong , Guo Ran , Sun Lining
Published: July 2023

Cycloid drives are widely used in various mechanical systems due to their high reduction ratio, compact size, and high efficiency. Tooth surface wear is a major problem that affects the reliability and durability of cycloid drives. However, compared to the research on the wear of involute gears, the prediction of tooth surface wear in cycloid drives is relatively limited and less extensive. To fill this gap, the theoretical wear model of the tooth surface of cycloid-pin gear pairs is proposed based on the Hertz contact theory and Archard’s formula, with consideration of tooth profile modifications. Firstly, the loaded tooth contact analysis model is established to determine the relative sliding velocity and tooth contact stress. Secondly, the calculation steps of single tooth surface wear are presented within one gear mesh cycle. With this, the effects of the tooth profile modifications, the operating conditions such as output torque, input speed, and the assembly eccentricity on the wear depth within one gear mesh cycle are investigated. This study gives a deeper understanding of the tooth surface wear mechanisms of cycloid drives and could be employed to assist gear design and to improve the wear resistance.
Numerical and Machine-Aided Experimental Models for Simulating the 3D Compliance of a Toothbrush
Authors: Cirelli Marco , Cellupica Alessio , D’Angelo Luca , Mazur Marta , Valentini Pier Paolo
Published: July 2023

One of the most discussed topics in toothbrush design is identifying the contact force exerted by the bristles on the teeth. Each bristle must generate a contact force to ensure tooth cleaning without damaging it. Numerical simulation is a very powerful tool for understanding the influence of design parameters (bristle shape and materials). This paper proposes a flexible multibody model to efficiently simulate the 3D compliance of a toothbrush. Each bristle is modeled using a discrete, flexible approach. The contact between the bristles and the target surface is established using the penalty contact method. An experimental test bench with a Universal Robot and a flat, transparent surface is set up. Validation is provided by comparing the reaction forces of the toothbrush with the reaction forces acquired by the load cells mounted on the end effector of the Robot. The results demonstrate the accuracy of estimating normal and tangential forces in various operating situations. The discrete flexible multibody technique has also demonstrated its viability in evaluating the displacement of the bristles when the toothbrush’s base body is put through a specified motion, even when it is exposed to a sudden change in direction. As a result, the model can be effectively utilized to assess how well various brush classes remove dental plaque. Therefore, the suggested model could provide guidance for holistic modeling and advancements in toothbrush design to boost their effectiveness for thorough cleaning.
Efficient Red Kite Optimization Algorithm for Integrating the Renewable Sources and Electric Vehicle Fast Charging Stations in Radial Distribution Networks
Authors: Alshareef Sami , Fathy Ahmed
Published: July 2023

The high penetration of renewable energy resources’ (RESs) and electric vehicles’ (EVs) demands to power systems can stress the network reliability due to their stochastic natures. This can reduce the power quality in addition to increasing the network power losses and voltage deviations. This problem can be solved by allocating RESs and EV fast charging stations (FCSs) in suitable locations on the grid. So, this paper proposes a new approach using the red kite optimization algorithm (ROA) for integrating RESs and FCSs to the distribution network through identifying their best sizes and locations. The fitness functions considered in this work are: reducing the network loss and minimizing the voltage violation for 24 h. Moreover, a new version of the multi-objective red kite optimization algorithm (MOROA) is proposed to achieve both considered fitness functions. The study is performed on two standard distribution networks of IEEE-33 bus and IEEE-69 bus. The proposed ROA is compared to dung beetle optimizer (DBO), African vultures optimization algorithm (AVOA), bald eagle search (BES) algorithm, bonobo optimizer (BO), grey wolf optimizer (GWO), multi-objective multi-verse optimizer (MOMVO), multi-objective grey wolf optimizer (MOGWO), and multi-objective artificial hummingbird algorithm (MOAHA). For the IEEE-33 bus network, the proposed ROA succeeded in reducing the power loss and voltage deviation by 58.24% and 90.47%, respectively, while in the IEEE-69 bus it minimized the power loss and voltage deviation by 68.39% and 93.22%, respectively. The fetched results proved the competence and robustness of the proposed ROA in solving the problem of integrating RESs and FCSs to the electrical networks.
An Innate Moving Frame on Parametric Surfaces: The Dynamics of Principal Singular Curves
Authors: Chu Moody T. , Zhang Zhenyue
Published: July 2023

This article reports an experimental work that unveils some interesting yet unknown phenomena underneath all smooth nonlinear maps. The findings are based on the fact that, generalizing the conventional gradient dynamics, the right singular vectors of the Jacobian matrix of any differentiable map point in directions that are most pertinent to the infinitesimal deformation of the underlying function and that the singular values measure the rate of deformation in the corresponding directions. A continuous adaption of these singular vectors, therefore, constitutes a natural moving frame that carries indwelling information of the variation. This structure exists in any dimensional space, but the development of the fundamental theory and algorithm for surface exploration is an important first step for immediate application and further generalization. In this case, trajectories of these singular vectors, referred to as singular curves, unveil some intriguing patterns per the given function. At points where singular values coalesce, curious and complex behaviors occur, manifesting specific landmarks for the function. Upon analyzing the dynamics, it is discovered that there is a remarkably simple and universal structure underneath all smooth two-parameter maps. This work delineates graphs with this interesting dynamical system and the possible new discovery that, analogous to the double helix with two base parings in DNA, two strands of critical curves and eight base pairings could encode properties of a generic and arbitrary surface. This innate structure suggests that this approach could provide a unifying paradigm in functional genetics, where all smooth surfaces could be genome-sequenced and classified accordingly. Such a concept has sparked curiosity and warrants further investigation.
Exact Solution of Non-Homogeneous Fractional Differential System Containing 2n Periodic Terms under Physical Conditions
Authors: Seddek Laila F. , Ebaid Abdelhalim , El-Zahar Essam R. , Aljoufi Mona D.
Published: July 2023

This paper solves a generalized class of first-order fractional ordinary differential equations (1st-order FODEs) by means of Riemann–Liouville fractional derivative (RLFD). The principal incentive of this paper is to generalize some existing results in the literature. An effective approach is applied to solve non-homogeneous fractional differential systems containing 2n periodic terms. The exact solutions are determined explicitly in a straightforward manner. The solutions are expressed in terms of entire functions with fractional order arguments. Features of the current solutions are discussed and analyzed. In addition, the existing solutions in the literature are recovered as special cases of our results.
Applying Neural Networks to Recover Values of Monitoring Parameters for COVID-19 Patients in the ICU
Authors: Celada-Bernal Sergio , Pérez-Acosta Guillermo , Travieso-González Carlos M. , Blanco-López José , Santana-Cabrera Luciano
Published: July 2023

From the moment a patient is admitted to the hospital, monitoring begins, and specific information is collected. The continuous flow of parameters, including clinical and analytical data, serves as a significant source of information. However, there are situations in which not all values from medical tests can be obtained. This paper aims to predict the medical test values of COVID-19 patients in the intensive care unit (ICU). By retrieving the missing medical test values, the model provides healthcare professionals with an additional tool and more information with which to combat COVID-19. The proposed approach utilizes a customizable deep learning model. Three types of neural networks, namely Multilayer Perceptron (MLP), Long/Short-Term Memory (LSTM), and Gated Recurrent Units (GRU), are employed. The parameters of these neural networks are configured to determine the model that delivers the optimal performance. Evaluation of the model’s performance is conducted using metrics such as Root Mean Square Error (RMSE), Mean Absolute Percentage Error (MAPE), and Mean Absolute Error (MAE). The application of the proposed model achieves predictions of the retrieved medical test values, resulting in RMSE = 7.237, MAPE = 5.572, and MAE = 4.791. Moreover, the article explores various scenarios in which the model exhibits higher accuracy. This model can be adapted and utilized in the diagnosis of future infectious diseases that share characteristics with Coronavirus Disease 2019 (COVID-19).
On a Fast Hough/Radon Transform as a Compact Summation Scheme over Digital Straight Line Segments
Authors: Nikolaev Dmitry , Ershov Egor , Kroshnin Alexey , Limonova Elena , Mukovozov Arseniy , Faradzhev Igor
Published: July 2023

The Hough transform, interpreted as the discretization of the Radon transform, is a widely used tool in image processing and machine vision. The primary way to speed it up is to employ the Brady–Yong algorithm. However, the accuracy of the straight line discretization utilized in this algorithm is limited. In this study, we propose a novel algorithm called ASD2 that offers fast computation of the Hough transform for images of arbitrary sizes. Our approach adopts a computation scheme similar to the Brady–Yong algorithm but incorporates the best possible line discretization for improved accuracy. By employing the Method of Four Russians, we demonstrate that for an image of size n×n where n=8q and q∈N, the computational complexity of the ASD2 algorithm is O(n8/3) when summing over O(n2) digital straight line segments.
Thermal Responses and the Energy Spectral of Diatomic Molecules Using Nikiforov–Uvarov Methodology
Authors: Roshanzamir Muhammad
Published: July 2023

The parametric Nikiforov–Uvarov approach and the Greene–Aldrich approximation scheme were used to achieve approximate analytical solutions to the Schrödinger equation, involving an interaction of the modified deformed Hylleraas potential mixed linearly with the improved Frost–Musulin diatomic molecular potential. For each ℓ-state, the energy spectra and normalized wave functions were generated from the hypergeometric function in the closed form. The thermal properties of such a system, including the vibrational partition function, vibrational mean energy, vibrational mean free energy, vibrational specific heat capacity, and vibrational entropy, were then calculated for the selected diatomic molecules using their experimental spectroscopic parameters. Furthermore, the peculiar conditions of this potential were evaluated, and their energy eigenvalues were calculated for the purpose of comparison. The acquired results were found to be in reasonable agreement with those reported in the literature.
Three-Dimensional Cellular Automaton for Modeling of Self-Similar Evolution in Biofilm-Forming Bacterial Populations
Authors: Sarukhanian Samvel , Maslovskaya Anna , Kuttler Christina
Published: July 2023

Bacterial populations often form colonies and structures in biofilm. The paper aims to design suitable algorithms to simulate self-similar evolution in this context, specifically by employing a hybrid model that includes a cellular automaton for the bacterial cells and their dynamics. This is combined with the diffusion of the nutrient (as a random walk), and the consumption of nutrients by biomass. Lastly, bacterial cells divide when reaching high levels. The algorithm computes the space-time distribution of biomass under limited nutrient conditions, taking into account the collective redistribution of nutrients. To achieve better geometry in this modified model approach, truncated octahedron cells are applied to design the lattice of the cellular automaton. This allows us to implement self-similar realistic bacterial biofilm growth due to an increased number of inner relations for each cell. The simulation system was developed using C# on the Unity platform for fast calculation. The software implementation was executed in combination with the procedure of surface roughness measurements based on computations of fractional dimensions. The results of the simulations qualitatively correspond to experimental observations of the population dynamics of biofilm-forming bacteria. Based on in silico experiments, quantitative dependencies of the geometrical complexity of the biofilm structure on the level of consumed nutrients and oxygen were revealed. Our findings suggest that the more complex structure with a fractal dimension of the biofilm boundaries (around 2.6) corresponds to a certain range of nutrient levels, after which the structure degenerates and the biofilm homogenizes, filling the available space provided and tending towards a strictly 3D structure. The developed hybrid approach allows realistic scenario modeling of the spatial evolution of biofilm-forming bacterial populations and specifies geometric characteristics of visualized self-similar biofilm bacterial structures.
Borel Chain Conditions of Borel Posets
Authors: Xiao Ming
Published: July 2023

We study the coarse classification of partial orderings using chain conditions in the context of descriptive combinatorics. We show that (unlike the Borel counterpart of many other combinatorial notions), we have a strict hierarchy of different chain conditions, similar to the classical case.
Examining the Bilateral Relationship between Mexico and South Korea through the Trade in Value-Added Perspective, 2000–2021
Authors: Morales-López Rodrigo , Quintana-Romero Luis , Mun Nam Kwon , Oh Inhye
Published: July 2023

This article examines the trade relationship between Mexico and South Korea through the lens of trade in value-added perspective. Using the global input–output model, we dissect gross exports into their value-added components to analyze the sectors benefiting most from value-added generation in both countries. To do this, we use the multiregional input–output matrices developed by the Asian Development Bank (ADB). The results show a growing bilateral relationship between 2000 and 2021, with South Korea having a stronger position by generating a larger share of value-added linked to the bilateral relationship. Nevertheless, the gap has narrowed over time. Notably, South Korean exports to Mexico have substantially contributed to value-added generation in technology-based manufacturing sectors such as machinery, equipment, electronics, electrical, and optical products. Similarly, Mexico’s mining sector increasingly relies on exports to South Korea for value-added generation. The trends observed in this study’s findings persist even amidst the reconfiguration of Global Value Chains, indicating that a free trade agreement between Mexico and South Korea has the potential to further enhance value-added generation.
Numerical Simulation Analysis of Temperature Distribution of NbC-Reinforced Ti-Based Composite Coating by Laser Cladding
Authors: Hu Zhiguo , Li Chonggui , Tian Dachuan , Li Xintong , Wang Jinqian , Xu Zhenhai , Sun Xiaoguang
Published: July 2023

In this article, three-dimensional numerical modeling of the laser cladding process by Ansys was proposed. The three-dimensional Gaussian heat source model was used to simulate the actual laser heat source to analyze the temperature distribution of the molten pool. The temperature distribution of the molten pool of TiAlSi + NbC coatings within different process parameters was obtained by simulation. To obtain finer simulation results, the thermophysical properties of TiAlSi + NbC powder and TiAlSi + NbC alloy were investigated, respectively. The temperature selection judgment mechanism, which is used to distinguish the powder and alloy elements, was built. The results showed that the laser power and laser scanning speed play a vital role in the temperature distribution along with the track width and the depth of the molten pool. The simulation values of the width and depth of the cladding layer under different processing parameters were obtained by using the temperature selection judgment mechanism and fitting. The results showed that the track width and depth had a positive correlation with the laser power, whereas they had a negative correlation with the laser scanning speed.
Internal Hydroforming of Large Stainless-Steel Eggshells from Stepped Preforms
Authors: Tang Yinhui , Zhang Jian , Zhan Ming , Jiao Huifeng , Cheng Peng , Dai Mingqiang
Published: July 2023

The internal hydroforming of large stainless-steel eggshells from a stepped preform is investigated in this paper. The nominal major and minor axes of the eggshell were 1537 and 1070 mm, respectively. The stepped preform was fabricated from thin-walled (1.9 mm thick) stainless-steel sheets and comprised twelve conical segments inscribed inside the target eggshell. The preform was then hydroformed, and its wall thickness and shape were measured. The yield load distribution and material hardening of the hydroforming process were investigated analytically. Nonlinear finite-element analyses were employed to further investigate hydroforming behaviors and the effect of weld lines on hydroforming. The experimental, numerical, and analytical results were consistent. The results confirm that, during the hydroforming process, considerable springback occurs for large eggshells, which greatly affects forming precision. However, this effect can be reduced by accounting for the strengthening effect of weld lines.
Effect of Laser Power on the Recrystallization Temperature of an Additively Manufactured IN718
Authors: Son Deuk Hyun , Kim In Soo , Choi Baig-Gyu , Do Jeonghyeon , Choi Yoon Suk , Jung Joong Eun
Published: July 2023

Over the past few decades, there has been much research on additive manufacturing in both the academic and the industrial spheres to overcome the limitations of conventional manufacturing methods, thereby enabling the production of complex designs for improved performance. To achieve this purpose, it is crucial to meticulously set suitable laser parameters within the context of microstructural characteristics, including type and fraction of defects, texture development, residual stress, and grain size, etc. In the present study, we focused on recrystallization behavior, a type of relaxation process for accumulated thermal stress during the L-PBF process, as a function of laser power applied on the L-PBF process. The laser power has significant effects on the amount of recrystallized grain, directly related to the recrystallization temperature. Within the range of laser power used in this study, a downward trend was observed in the recrystallization temperature as the laser power increased from 370 W to 390 W. This trend suggests that higher laser power leads to a faster cooling rate, influenced by the volume of melt pool as well as the amount of heat dissipation from the melt pool, resulting in higher thermal stress during the process.
A Pretreatment of Refractory Gold Ores Containing Sulfide Minerals to Improve Gold Leaching by Ammonium Thiosulfate: A Model Experiment Using Gold Powder and Arsenic-Bearing Sulfide Minerals
Authors: Mhandu Takunda Joseph , Park Ilhwan , Jeon Sanghee , Hamatsu Sohta , Elakneswaran Yogarajah , Ito Mayumi , Hiroyoshi Naoki
Published: July 2023

The use of thiosulfate to extract gold from refractory ores is promising because of its non-toxicity and high selectivity. Sulfide minerals (i.e., pyrite, arsenopyrite, chalcopyrite), major gold carriers in refractory gold ores, however, hinder gold extraction due to the high consumption of a lixiviant. In this study, a new method to improve gold extraction from sulfide bearing gold ores is proposed based on the model experiments using a mixture of gold powder and arsenopyrite-bearing sulfide (HAsBS) ore. The effects of HAsBS ore on gold leaching in ammonium thiosulfate solutions were investigated, and it was found that gold extraction in the presence of HAsBS ore was suppressed because of the unwanted decomposition of thiosulfate on the surface of sulfide minerals. To improve gold extraction in the presence of the sulfide minerals, this study investigated the effects of the pretreatment of HAsBS ore using ammonium solutions containing cupric ions and confirmed that HAsBS ore was oxidized in the pretreatment and its surface was covered by the oxidation products. As a result, thiosulfate consumption was minimized in the subsequent gold leaching step using ammonium thiosulfate, resulting in an improvement in gold extraction from 10% to 79%.
Influence of B4C Particle Size on the Microstructure and Mechanical Properties of B4C/Al Composites Fabricated by Pressureless Infiltration
Authors: Liu Yao , Peng Haokai , Wei Longjun , Peng Hao , Ma Donglin , Leng Yongxiang
Published: July 2023

To investigate the effect of B4C particle size on the microstructure and mechanical properties of B4C/Al composites, and to provide theoretical guidance for the subsequent thermal processing of composites, B4C/Al composites with varying B4C particle sizes (0.2 µm, 0.5 µm, 1 µm, 10 µm) were fabricated using pressureless infiltration. The microstructure of the composites was characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM), while the mechanical properties were analyzed by hardness test, three-point bending and high temperature compression. The results indicated that Al3BC and AlB2 were the primary interfacial reaction products in B4C/Al composites, and interface reaction could be alleviated with increasing particle size. B4C/Al composites with larger B4C particle sizes exhibited a relatively uniform and discrete distribution of B4C, while those with smaller B4C particle sizes showed agglomeration of B4C. The Vickers hardness and peak flow stress of B4C/Al composites gradually decreased with the increase of B4C particle size, while the bending strength, flexural modulus, and fracture toughness tended to increase. In addition, when B4C particle size was 10 µm, the composites displayed optimal comprehensive performance with the lowest peak flow stress (150 MPa) and the highest fracture toughness (12.75 MPa·m1/2).
Comparative Analysis of Amino Acid and Biogenic Amine Compositions of Fermented Grape Beverages
Authors: Nokhoijav Erdenetsetseg , Guba Andrea , Vadadokhau Uladzislau , Tőzsér József , Győri Zoltán , Kalló Gergő , Csősz Éva
Published: July 2023

Amino acids and biogenic amines are important components of food and beverages. In grape-derived products such as wine and wine vinegar, they can have different origins and can influence the odor and taste of the products. Their concentration is influenced by the grape variety, vintage, and winemaking process. In our study, we carried out an LC-MS-based comparative analysis of 22 grape-derived beverages, including three different wine types and four wine vinegar samples from the Tokaj region in Hungary. The concentrations of 23 amino acids and 10 biogenic amines were examined, and the differences among the sample types were analyzed. The differences in the concentrations of some metabolites between Aszú–Furmint pairs originating from the same wineries and year provide information on the effect of botrytized grape on wine composition. Our data can provide further evidence on how the production process shapes the metabolite content of beverages and highlight the nutritional value of wine vinegar.
Metabolites Potentially Derived from Gut Microbiota Associated with Podocyte, Proximal Tubule, and Renal and Cerebrovascular Endothelial Damage in Early Diabetic Kidney Disease in T2DM Patients
Authors: Balint Lavinia , Socaciu Carmen , Socaciu Andreea Iulia , Vlad Adrian , Gadalean Florica , Bob Flaviu , Milas Oana , Cretu Octavian Marius , Suteanu-Simulescu Anca , Glavan Mihaela , Ienciu Silvia , Mogos Maria , Jianu Dragos Catalin , Ursoniu Sorin , Dumitrascu Victor , Vlad Daliborca , Popescu Roxana , Petrica Ligia
Published: July 2023

Complications due to type 2 diabetes mellitus (T2DM) such as diabetic kidney disease (DKD) and cerebral small vessel disease (CSVD) have a powerful impact on mortality and morbidity. Our current diagnostic markers have become outdated as T2DM-related complications continue to develop. The aim of the investigation was to point out the relationship between previously selected metabolites which are potentially derived from gut microbiota and indicators of endothelial, proximal tubule (PT), and podocyte dysfunction, and neurosonological indices. The study participants were 20 healthy controls and 90 T2DM patients divided into three stages: normoalbuminuria, microalbuminuria, and macroalbuminuria. Serum and urine metabolites were determined by untargeted and targeted metabolomic techniques. The markers of endothelial, PT and podocyte dysfunction were assessed by ELISA technique, and the neurosonological indices were provided by an ultrasound device with high resolution (MYLAB 8-ESAOTE Italy). The descriptive statistical analysis was followed by univariable and multivariable linear regression analyses. In conclusion, in serum, arginine (sArg), butenoylcarnitine (sBCA), and indoxyl sulfate (sIS) expressed a biomarker potential in terms of renal endothelial dysfunction and carotid atherosclerosis, whereas sorbitol (sSorb) may be a potential biomarker of blood–brain barrier (BBB) dysfunction. In urine, BCA and IS were associated with markers of podocyte damage, whereas PCS correlated with markers of PT dysfunction.
A Flexible Supercapacitor Based on Niobium Carbide MXene and Sodium Anthraquinone-2-Sulfonate Composite Electrode
Authors: Wang Guixia , Yang Zhuo , Nie Xinyue , Wang Min , Liu Xianming
Published: July 2023

MXene-based composites have been widely used in electric energy storage device. As a member of MXene, niobium carbide (Nb2C) is a good electrode candidate for energy storage because of its high specific surface area and electronic conductivity. However, a pure Nb2C MXene electrode exhibits limited supercapacitive performance due to its easy stacking. Herein, sodium anthraquinone-2-sulfonate (AQS) with high redox reactivity was employed as a tailor to enhance the accessibility of ions and electrolyte and enhance the capacitance performance of Nb2C MXene. The resulting Nb2C–AQS composite had three-dimensional porous layered structures. The supercapacitors (SCs) based on the Nb2C–AQS composite exhibited a considerably higher electrochemical capacitance (36.3 mF cm−2) than the pure Nb2C electrode (16.8 mF cm−2) at a scan rate of 20 mV s−1. The SCs also exhibited excellent flexibility as deduced from the almost unchanged capacitance values after being subjected to bending. A capacitance retention of 99.5% after 600 cycles was observed for the resulting SCs, indicating their good cycling stability. This work proposes a surface modification method for Nb2C MXene and facilitates the development of high-performance SCs.
Photodegradation of Tropaeolin O in the Presence of Ag-Doped ZnO Nanoparticles
Authors: Bailon-Ruiz Sonia J. , Cedeño-Mattei Yarilyn , Torres-Torres Kerianys , Alamo-Nole Luis
Published: July 2023

Azo dyes such as Tropaeolin O have diverse applications in the textile, food, and biomedical industries. However, their recalcitrant properties make them toxic substances in surface waters. Nanocatalysts are photoactive nanoparticles that generate reactive oxygen species to destroy organic compounds. Moreover, the presence of dopant agents in the nanoparticles’ crystalline structure efficiently enhances photocatalytic activity. Ag-doped ZnO nanoparticles were prepared in ethylene glycol at 197 °C and characterized by UV-Vis absorption, photoluminescence, high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDX), and electron diffraction (ED). The particles were mainly spherical with a size of ~10 nm, a hexagonal structure, and an elemental composition of 56.2% Zn, 37.8% O, and 5.9% Ag. The particles evidenced a broad absorption peak in the UV region and two emission peaks. Absorption analysis indicates that 92% and 58% of Tropaeolin O were degraded using 100 and 50 ppm of Ag-doped ZnO nanoparticles, respectively, during the first 550 min. Ion chromatograms selected using quadrupole time-of-flight liquid chromatography-mass spectrometry (QTOF-LC-MS) indicate a complete Tropaeolin O degradation (295.04 m/z) during the first 330 min. Initially, the nanocatalyst attacks the electron-rich groups (-OH and -NH), generating the 277.03 m/z [M-OH]+ and 174.02 m/z (molecule rupture on the azo group). In addition, small oxidized fragments 167.03 m/z and 114.03 m/z confirm the nanoparticles’ photocatalytic capacity, and oxidized chains indicate the tropaeolin’s opening rings (including phtalic acids) and mineralization.
Bioprospecting of a Thermostable L-Methioninase from Alcaligenes aquatilis BJ-1 in Agro-Industrial Waste
Authors: Javia Bhumi , Gadhvi Megha , Vyas Suhas , Dudhagara Pravin , Shyu Douglas J. H. , Chen Yih-Yuan , Dudhagara Dushyant
Published: July 2023

L-methioninase is an enzyme that has recently gained significant interest in the scientific community because of its potential as a targeted therapy for cancer. This study aims to isolate and identify extremophilic bacteria that could produce L-methioninase and to access the enzymatic potential of isolated bacteria under stress conditions, specifically in agro-industrial waste. In this study, a rare marine bacterium, Alcaligenes aquatilis BJ-1, exhibited the highest specific activity of 4.61 U/mg at an optimum pH of 8.3. The L-methioninase was purified 4.3-fold and 7.15-fold by acetone precipitation and Sephadex G-100 gel filtration chromatography, which revealed a molecular weight of 46 kDa. In addition, agriculture waste materials such as cottonseed oil cake had the highest L-methioninase production. Moreover, A. aquatilis BJ-1 can tolerate and produce enzymes in the presence of 10% NaCl, 6% KCl, and 4% MgSO4. Similarly, substrates such as L-asparagine, L-glutamine, L-alanine, and L-tyrosine were found suitable to increase enzyme production. The strain produced L-methioninase in the presence of various heavy metals. Maximum enzyme activity was found in Zn2+ at 0.1% (2.52 U/mL), Li2+ at 0.03% (2.90 U/mL), and Ni2+ at 0.01% (2.78 U/mL), as compared to the control (2.23 U/mL) without metal. Enzyme production was also observed at a high temperature (60 °C), with the produced enzymes possessing antioxidant properties. In addition, no hemolytic activity was observed. The results indicate that A. aquatilis BJ-1 is an appropriate bacterium for metal bioremediation procedures in unfavorable circumstances.