bluuebunny/crossref_metadata_2025 huggingface dataset:
Virtual Land and Water Flows and Driving Factors Related to Livestock Products Trade in China
Authors: Zhou Meina , Wang Junying , Ji Hao
Published: July 2023

Agricultural trade, which involves the exchange of virtual water and land resources, can effectively regulate the allocation of resources among countries while enhancing the well-being of resource-rich and resource-poor nations. China’s animal products trade market concentration is greater, and the livestock industry consumes more water than other agricultural sectors. In order to alleviate the pressure on China’s domestic water and land resources and to ensure that Chinese residents have access to animal products, this article examines the trade situation and drivers of virtual water and land resources related to Chinese animal products trade. This study used the heat equivalent method to measure the virtual water and land flows of the import and export of beef, pork, and mutton from 1992 to 2018, which is followed by the gravity model to investigate the factors impacting China’s flow of virtual land and water related to livestock products trade. We found that the economic development and the agricultural resources of exporters, as well as China’s agricultural employment rates, have a stable beneficial impact on China’s livestock imports. The population of importing nations, China’s cultivated land area, and the livestock production index of importers and exporters have a positive impact on the export of livestock products from China. Our results remain robust following a series of additional tests.
Geographical Patterns and Influencing Mechanisms of Digital Rural Development Level at the County Scale in China
Authors: Li Tianyu , Wang Shengpeng , Chen Pinyu , Liu Xiaoyi , Kong Xiang
Published: July 2023

Digital rural development has become an emerging dynamic force for high-quality rural development in China. This paper constructs the “environmental-economic-social” analysis framework for digital rural development, analyzes the spatial variation of the digital rural development level (DRDL) in Chinese counties in 2020, and conducts the factor detection and interaction detection of its influencing factors. It is found that: (1) digital rural development has its own unique spatial differentiation mechanism, which can be analyzed from three dimensions: environmental system, economic system, and social system, which play a fundamental role, decisive role, and a magnifying effect on digital rural development, respectively. (2) The DRDL in China’s counties has significant spatial distribution, spatial correlation, and spatial clustering characteristics. The DRDL in general shows a decreasing distribution trend from coastal to inland regions, and the overall differences in DRDL mainly come from intra-regional differences rather than inter-regional differences. The rural infrastructure digitalization dimension has stronger spatial correlation while the spatial correlation of the rural governance digitalization dimension is weaker. There are obvious hotspot and coldspot areas in the DRDL, with large differences between the coldspot and hotspot areas of different sub-dimensions. (3) The spatial divergence of the DRDL is closely related to geographical elements and is the result of the combined effect of several geographical factors. The factor detection results show that the dominant factors within the four regions are significant different. The interaction detection results show that the driving force of the two-factor interaction is stronger than that of the single-factor interaction and that the interaction among the factors further deepens the spatial differentiation of the DRDL.
The Interaction between Language Skills and Cross-Cultural Competences in Bilingual Programs
Authors: Amor María Isabel , Tinedo-Rodríguez Antonio-Jesús , Osuna-Rodríguez Mercedes
Published: July 2023

Language and culture are intrinsically intertwined, and culture should not be considered as an expendable fifth skill in language teaching. Bilingual programs are expected to be a key element to enhance culture learning and to develop intercultural competence due to the extensive use of the L2. This study aimed at exploring the effects of bilingual programs for the development of the formerly mentioned skills in language learners. It also sought to contrast students’ insights with teachers’ perceptions on the implementation of bilingual programs and their effects on students’ language and culture learning. The sample consisted of 136 students and 35 Spanish teachers. The results should be carefully interpreted as they showed that there is no significant difference between the perception of bilingual and non-bilingual students in their development of intercultural competence and culture learning. Additionally, content teachers usually adhere to narratives of resistance towards CLIL programs. We concluded that the current implementation of bilingual programs should be specifically addressed. In this regard, it is important to focus on teacher training and to foster exchange programs for teachers and students. Moreover, addressing the availability of human and material resources is essential.
Prevalence of High-Risk HPV Subtypes and Efficacy of the HPV Vaccine in Preventing Cervical Epithelial Lesions: Survey and Insights from a German Study
Authors: Abbas Mahmoud , de Jonge Jan , Bettendorf Olaf
Published: July 2023

Background: Historically, cervical cytology has been the standard method for detecting dysplastic cervical changes. However, extensive research has established that human papillomavirus (HPV) infection is a primary cause of these changes, necessitating a shift in screening and preventive strategies towards the molecular detection of high-risk HPV subtypes. To combat HPV infection, prophylactic vaccines have been developed, including the nonavalent, quadrivalent, and bivalent vaccines. An essential criterion for an effective HPV vaccine is to provide comprehensive coverage against the most prevalent high-risk HPV types associated with cervical cancer, ensuring optimal efficacy in preventing cervical lesions. Long-term protection against these types is crucial for effective prevention strategies; Material and Methods: A cohort of 210,510 women’s samples was included in the analysis conducted within one year of implementing a screening program in Germany. The screening program involved the molecular detection of high-risk HPV subtypes, targeting specific age groups. The cohort comprised 63,710 women below 35 years of age and 146,800 women aged 35 years and above. The selection of high-risk HPV subtypes followed the guidelines provided by Becton-Dickinson. This study focused exclusively on cases with a documented history of vaccination, which were categorized into two main groups: Group I consisted of vaccinated individuals under 35 years old (12,765 cases), while Group II comprised vaccinated individuals aged 35 years and above (296 cases); Results: The HPV types HPV56/59/66 were found to be widely distributed across all age groups, with certain age groups exhibiting a higher incidence compared to HPV16 and HPV18. Similarly, HPV35/39/69, along with HPV31 and HPV45, were also observed to have a broad distribution among women. The incidence of high-grade squamous intraepithelial lesions (HSIL), including both CIN2 and CIN3, varied between 0.076% and 0.5% across all age groups, regardless of the individuals’ vaccination status; Aim of the study: Our study provides valuable insights into the distribution, incidence, and prevalence of various high-risk HPV subtypes, including HPV56/59/66, HPV33/58, HPV35/39/68, and HPV45, in relation to precancerous cervical lesions. These subtypes are not adequately covered by the currently available HPV vaccines. Addressing the discrepancies between the prevalent HPV subtypes and existing vaccines is crucial in developing an ideal HPV vaccine that offers comprehensive protection. Tailoring screening programs and vaccination strategies to the local distribution of HPV subtypes is essential for effective prevention. By raising awareness and implementing targeted preventive measures, including vaccination, we can significantly reduce the incidence of precancerous and cancerous cervical lesions.
Experimental Study on Cementless PET Mortar with Marble Powder and Iron Slag as an Aggregate
Authors: Khan Shahid Ullah , Rahim Abdur , Md Yusoff Nur Izzi , Khan Ammad Hassan , Tabassum Saadia
Published: July 2023

There has been an increase in plastic production during the past decades, yet the recycling of plastic remains relatively low. Incorporating plastic in concrete can mitigate environmental pollution. The use of waste polyethylene terephthalate (PET) bottles as an aggregate weakens properties of concrete. An alternative is to use PET bottles as a binder in the mortar. The PET binder mixed with sand results in weak mortar. Marble and iron slag can enhance PET mortar properties by preventing alkali reactions. This study examines the mechanical and durability properties of PET mortar with different mixes. The mixes were prepared as plastic and marble (PM); plastic and iron slag (PI); plastic, sand, and marble (PSM); plastic, iron slag, and marble (PIM); and plastic, sand, and iron slag (PSI). PM with 30–45% plastic content had increased compressive and flexural strength up to 35.73% and 20.21%, respectively. PI with 30–35% plastic content showed strength improvements up to 29.19% and 5.02%, respectively. However, at 45% plastic content, strength decreased by 8.8% and 27.90%. PSM, PIM, and PSI specimens had nearly double the strength of ordinary Portland cement (OPC) mortar. The durability of PET mortar in chemical solutions, mainly 5% HCl and 20% NaOH, indicate that mass decreased after 3, 7, and 28 days. All specimens showed good resistance to HCl and NaCl solutions compared to OPC mortar. However, its resistance to NaOH is low compared to OPC mortar. PET mortar without cement showed higher strength and durability than cement mortar, making it suitable for paver tiles, drainage systems, and roads.
Recent Advances in the Synthesis and Application of Vacancy-Ordered Halide Double Perovskite Materials for Solar Cells: A Promising Alternative to Lead-Based Perovskites
Authors: Murugan Santhosh , Lee Eun-Cheol
Published: July 2023

Lead-based halide perovskite materials are being developed as efficient light-absorbing materials for use in perovskite solar cells (PSCs). PSCs have shown remarkable progress in power conversion efficiency, increasing from 3.80% to more than 25% within a decade, showcasing their potential as a promising renewable energy technology. Although PSCs have many benefits, including a high light absorption coefficient, the ability to tune band gap, and a long charge diffusion length, the poor stability and the toxicity of lead represent a significant disadvantage for commercialization. To address this issue, research has focused on developing stable and nontoxic halide perovskites for use in solar cells. A potential substitute is halide double perovskites (HDPs), particularly vacancy-ordered HDPs, as they offer greater promise because they can be processed using a solution-based method. This review provides a structural analysis of HDPs, the various synthesis methods for vacancy-ordered HDPs, and their impact on material properties. Recent advances in vacancy-ordered HDPs are also discussed, including their role in active and transport layers of solar cells. Furthermore, valuable insights for developing high-performance vacancy-ordered HDP solar cells are reported from the detailed information presented in recent simulation studies. Finally, the potential of vacancy-ordered HDPs as a substitute for lead-based perovskites is outlined. Overall, the ability to tune optical and electronic properties and the high stability and nontoxicity of HDPs have positioned them as a promising candidate for use in photovoltaic applications.
Structural and Thermal Examinations of Polyamide Modified with Fly Ash from Biomass Combustion
Authors: Caban Renata , Gnatowski Adam
Published: July 2023

This paper presents the results of examinations of the structure and crystallinity of polyamide (PA6) modified with fly ash from biomass combustion in a fluidized-bed boiler. Composites based on a PA6 matrix were examined. They contained 5, 10, and 15 wt% fly ash. Fourier-transform infrared with attenuated total reflectance spectroscopy (FTIR-ATR) was used to identify the characteristic functional groups present in the chemical structure of polyamide and composites based on its matrix. Structural analysis was performed using a differential scanning calorimeter (DSC) and microscopic examinations. Analysis of the values of thermal effects determined using the DSC technique allowed for the evaluation of the degree of crystallinity of the materials studied. Polyamide is usually considered to be a two-phase system consisting of crystalline and amorphous regions. The addition of the filler in the form of fly ash reduced the degree of crystallinity of the studied specimens. Based on the FTIR-ATR spectra and the recorded DSC curves, it was found that the α-phase was the dominant crystalline phase in the studied materials. Microscopic examinations were conducted to analyze the microstructure of the materials, providing information on the distribution and shape of the filler particles. Most of the particles ranged in size from a few to tens of micrometers. Furthermore, the use of scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDS) allowed for the analysis of the distribution of chemical elements in selected filler particles.
Polymeric Biocomposite Based on Thermoplastic Polyurethane (TPU) and Protein and Elastomeric Waste Mixture
Authors: Nituica Mihaela , Oprea Ovidiu , Stelescu Maria Daniela , Sonmez Maria , Georgescu Mihai , Alexandrescu Laurentia , Motelica Ludmila
Published: July 2023

Polymeric biocomposites based on TPU/recycled TPUW/mixed leather and SBR rubber waste unmodified/modified with polydimethylsiloxane/PE-g-MA in different percentages were made via the mixing technique on a Plasti-Corder Brabender mixer with an internal capacity of 350 cm3. The waste, which came from the shoe industry, was cryogenically ground with the help of a cryogenic cyclone mill at micrometric sizes and different speeds. For the tests, standard plates of 150 × 150 × 2 mm were obtained in a laboratory-scale hydraulic press via the method of compression between its plates, with well-established parameters. The biocomposites were tested physico-mechanically and rheologically (MFI) according to the standards in force on polymer-specific equipment, also via FT-IR spectroscopy and microscopy, as well as via differential scanning calorimetry—DSC. Following the tests carried out, according to the standard for use in the footwear industry, at least two samples present optimal values (of interest) suitable for use in the footwear industry by injection or pressing in forming moulds.
Analysis of Mechanical Properties and Failure Mechanism of Lightweight Aggregate Concrete Based on Meso Level
Authors: Al-sayed Safwan , Wang Xi , Peng Yijiang
Published: July 2023

The relationship between the macroscopic mechanical properties of lightweight aggregate concrete and its microstructure is a hot topic in the discipline of concrete materials. It is very meaningful to provide an efficient numerical analysis method to conduct a meso-level analysis. This study proposes an automatic dissection algorithm and adapts the calculation program of the base force element method to conduct a non-linear damage analysis. In the numerical simulation, three groups of 100 mm × 100 mm × 100 mm specimens were selected for the uniaxial compression experiment and uniaxial tensile experiment, respectively. The average tensile strength of the numerical simulation for the uniaxial compression test was 21.86 MPa. The stress–strain softening curve, stress contour plot, strain contour plot, and damage plot of the light aggregate concrete were also analyzed. These research results provide data for analyzing the failure mechanism of light aggregate concrete and reveal the failure mechanism of light aggregate concrete. At the same time, the reliability of the proposed algorithm is verified. Our aim is to provide a more efficient and accurate analysis of meso-damage in lightweight aggregate concrete, which benefits industries involved in production, construction, and structural engineering.
Fabrication of mm-Scale Complementary Split Ring Resonators, for Potential Application as Water Pollution Sensors
Authors: Viskadourakis Zacharias , Fanourakis George , Tamiolakis Evangelos , Theodosi Anna , Katsara Klytaimnistra , Vrithias Nikolaos Rafael , Tsilipakos Odysseas , Kenanakis George
Published: July 2023

Rectangular, millimeter-scale complementary split ring resonators were fabricated, employing the so-called Computer Numerical Control method, combined with a home-built mechanical engraver. Their electromagnetic performance was thoroughly investigated with respect to their dimensions in the frequency regime between 2 and 9 GHz via combining experiments and corresponding theoretical simulations, wherein a considerably effective consistency was obtained. Moreover, their sensing response was extensively investigated against various aqueous solutions enriched with typical fertilizers used in agriculture, as well as detergents commonly used in every-day life. Corresponding experimental results evidently establish the capability of the studied metasurfaces as potential sensors against water pollution.
The Use of a Radial Basis Function Neural Network and Fuzzy Modelling in the Assessment of Surface Roughness in the MDF Milling Process
Authors: Szwajka Krzysztof , Zielińska-Szwajka Joanna , Trzepieciński Tomasz
Published: July 2023

Wood-based composites are increasingly used in the industry not only because of the shortage of solid wood, but above all because of the better properties, such as high strength and aesthetic appearance compared to wood. Medium-density fiberboard (MDF) is a wood-based composite that is widely used in the furniture industry. In this work, an attempt was made to predict the surface roughness of the machined MDF in the milling process based on acceleration signals from an industrial piezoelectric sensor installed in the cutting zone. The surface roughness parameter Sq was adopted for the evaluation and measurement of surface roughness. The surface roughness prediction was performed using a radial basis function (RBF) artificial neural network (ANN) and a Takagi–Sugeno––Kang (TSK) fuzzy model with subtractive clustering. In the research, as inputs to the ANNs and fuzzy model, the kinematic parameters of the cutting process and selected measures of the acceleration signal were adopted. At the output, the values of the surface roughness parameter Sq were obtained. The results of the experiments show that the surface roughness is influenced not only by the kinematic parameters of the cutting, but also by the vibrations generated during the milling process. Therefore, by combining information on the cutting kinematics parameters and vibration, the accuracy of the surface roughness prediction in the milling process of MDF can be improved. The use of TSK fuzzy modelling based on the subtractive clustering method for integrating the information from many acceleration signal measurements in the examined range of cutting conditions meant the surface roughness was predicted with high accuracy and high reliability. With the help of two tested artificial intelligence tools, it is possible to estimate the surface roughness of the workpiece with only a small error. When using a radial neural network, the root mean square error for estimating the value of the Sq parameter was 0.379 μm, while the estimation error based on fuzzy logic was 0.198 μm. The surface of the sample made with the cutting parameters vc = 76 m/min and vf = 1200 mm/min is characterized by a less concentrated distribution of ordinate densities, compared to the surface of the sample cut with lower feed rates but at the same cutting speed. The most concentrated distribution of ordinate density (for the cutting speed vc = 76 m/min) is characterized by the surface, where the feed rate value was vf = 200 mm/min, with 90% of the material concentrated in the profile height of 28.2 μm. When using an RBF neural network, the RMSE of estimating the value of the Sq parameter was 0.379 μm, while the estimation error based on fuzzy logic was 0.198 μm.
The Flexural Strength Prediction of Carbon Fiber/Epoxy Composite Using Artificial Neural Network Approach
Authors: Phunpeng Veena , Saensuriwong Karunamit , Kerdphol Thongchart , Uangpairoj Pichitra
Published: July 2023

There is a developing demand for natural resources because of the growing population. Alternative materials have been developed to address these shortages, concentrating on characteristics such as durability and lightness. By researching composite materials, natural materials can be replaced. It is vital to consider the mechanical properties of composite materials when selecting them for a specific application. This study aims to measure the flexural strength of carbon fiber/epoxy composites. However, the cost of forming these composites is relatively high, given the expense of composite materials. Consequently, this study seeks to reduce molding costs by predicting flexural strength. Conducting many tests for each case is costly; therefore, it is necessary to discover an economical method. To accomplish this, the flexural strength of carbon fiber/epoxy composites was investigated using an artificial neural network (ANN) technique to reduce the expense of material testing. The output parameter investigated was flexural strength, while input parameters included ply orientation, manufacturing, width, thickness, and graphite filler percentage. The scope alternative was determined by identifying the values of variables that substantially affect the flexural strength. The prediction of flexural strength was deemed acceptable if the mean squared error (MSE) value was less than 0.001, and the coefficient of determination (R2) was greater than or equal to 0.95. The obtained results demonstrated an MSE of 0.003039 and an R2 value of 0.95274, indicating a low prediction error and high prediction accuracy for all flexural strength data. Thus, the outcomes of this study provide accurate predictions of flexural strength in the composite materials.
Effects of Cu, Zn Doping on the Structural, Electronic, and Optical Properties of α-Ga2O3: First-Principles Calculations
Authors: Zeng Hui , Wu Meng , Cheng Meijuan , Lin Qiubao
Published: July 2023

The intrinsic n-type conduction in Gallium oxides (Ga2O3) seriously hinders its potential optoelectronic applications. Pursuing p-type conductivity is of longstanding research interest for Ga2O3, where the Cu- and Zn-dopants serve as promising candidates in monoclinic β-Ga2O3. However, the theoretical band structure calculations of Cu- and Zn-doped in the allotrope α-Ga2O3 phase are rare, which is of focus in the present study based on first-principles density functional theory calculations with the Perdew–Burke–Ernzerhof functional under the generalized gradient approximation. Our results unfold the predominant Cu1+ and Zn2+ oxidation states as well as the type and locations of impurity bands that promote the p-type conductivity therein. Furthermore, the optical calculations of absorption coefficients demonstrate that foreign Cu and Zn dopants induce the migration of ultraviolet light to the visible–infrared region, which can be associated with the induced impurity 3d orbitals of Cu- and Zn-doped α-Ga2O3 near the Fermi level observed from electronic structure. Our work may provide theoretical guidance for designing p-type conductivity and innovative α-Ga2O3-based optoelectronic devices.
Motor Current-Based Degradation Modeling for Tool Wear Hybrid Prognostics in Turning Process
Authors: Gavahian Atefeh , Mechefske Chris K
Published: July 2023

For many machines with turning process systems, the application of economical indirect Tool Condition Monitoring (TCM) is enhanced by utilizing internal encoder spindle motor current signals. In this study, we proposed a novel approach to extract the total harmonic distortion (THD) feature associated with the metal cutting frequency of a specific working tool in the time domain. Our method entailed the application of filtered variational mode decomposition (VMD) combined with envelope analysis to demodulate the motor current signal and define TCM features based on the THD of odd harmonics, which are more related to the motor structure. These features serve as inputs for a hybrid prognostics technique, employing the Geometric Brownian Motion (GBM) to stochastically model the degradation process along with a deep learning transformer-based framework called the time series Transformer (TST) to improve the life prediction. Finally, to validate our approach, we conducted experiments based on 36 sets of tool run-to-wear data extracted from a CNC machine operating under turning process conditions using two different tools. Finally, we compared the degradation models based on the extracted odd-THD and even-THD features.
Dynamics of a Discrete Leslie–Gower Model with Harvesting and Holling-II Functional Response
Authors: Zhang Chen , Li Xianyi
Published: July 2023

Recently, Christian Cortés García proposed and studied a continuous modified Leslie–Gower model with harvesting and alternative food for predator and Holling-II functional response, and proved that the model undergoes transcritical bifurcation, saddle-node bifurcation and Hopf bifurcation. In this paper, we dedicate ourselves to investigating the bifurcation problems of the discrete version of the model by using the Center Manifold Theorem and bifurcation theory, and obtain sufficient conditions for the occurrences of the transcritical bifurcation and Neimark–Sacker bifurcation, and the stability of the closed orbits bifurcated. Our numerical simulations not only illustrate corresponding theoretical results, but also reveal new dynamic chaos occurring, which is an essential difference between the continuous system and its corresponding discrete version.
On a Fekete–Szegö Problem Associated with Generalized Telephone Numbers
Authors: Breaz Daniel , Wanas Abbas , Sakar Fethiye , Aydoǧan Seher
Published: July 2023

One of the important problems regarding coefficients of analytical functions (i.e., Fekete–Szegö inequality) was raised by Fekete and Szegö in 1933. The results of this research are dedicated to determine upper coefficient estimates and the Fekete–Szegö problem in the class WΣ(δ,λ;ϑ), which is defined by generalized telephone numbers. We also indicate some specific conditions and consequences of results found by us.
Euler–Darboux–Poisson Equation in Context of the Traveling Waves in a Strongly Inhomogeneous Media
Authors: Melnikov Ioann , Pelinovsky Efim
Published: July 2023

The existence of traveling waves in an inhomogeneous medium is a vital problem, the solution of which can help in modeling the wave propagation over long distances. Such waves can be storm waves or tsunami waves in the seas and oceans. The presence of solutions in the form of traveling waves indicates that the wave propagates without reflection and, therefore, can transfer energy over long distances. Traveling waves within the framework of the 1D variable-coefficient wave equation exist only for certain configurations of an inhomogeneous medium, some of which can be found by transforming the original equation to the Euler–Darboux–Poisson equation. The solution of the last equation for certain parameter values is expressed in elementary functions, which are the sum of waves running in opposite directions. The mathematical features of such a transformation are discussed in this paper.
Distributional Chaos and Sensitivity for a Class of Cyclic Permutation Maps
Authors: Zhao Yu , Anwar Waseem , Li Risong , Lu Tianxiu , Mo Zhiwen
Published: July 2023

Several chaotic properties of cyclic permutation maps are considered. Cyclic permutation maps refer to p-dimensional dynamical systems of the form φ(b1,b2,⋯,bp)=(up(bp),u1(b1),⋯,up−1(bp−1)), where bj∈Hj (j∈{1,2,⋯,p}), p≥2 is an integer, and Hj (j∈{1,2,⋯,p}) are compact subintervals of the real line R=(−∞,+∞). uj:Hj→Hj+1(j=1,2,…,p−1) and up:Hp→H1 are continuous maps. Necessary and sufficient conditions for a class of cyclic permutation maps to have Li–Yorke chaos, distributional chaos in a sequence, distributional chaos, or Li–Yorke sensitivity are given. These results extend the existing ones.
Optimization Based Layer-Wise Pruning Threshold Method for Accelerating Convolutional Neural Networks
Authors: Ding Yunlong , Chen Di-Rong
Published: July 2023

Among various network compression methods, network pruning has developed rapidly due to its superior compression performance. However, the trivial pruning threshold limits the compression performance of pruning. Most conventional pruning threshold methods are based on well-known hard or soft techniques that rely on time-consuming handcrafted tests or domain experience. To mitigate these issues, we propose a simple yet effective general pruning threshold method from an optimization point of view. Specifically, the pruning threshold problem is formulated as a constrained optimization program that minimizes the size of each layer. More importantly, our pruning threshold method together with conventional pruning works achieves a better performance across various pruning scenarios on many advanced benchmarks. Notably, for the L1-norm pruning algorithm with VGG-16, our method achieves higher FLOPs reductions without utilizing time-consuming sensibility analysis. The compression ratio boosts from 34% to 53%, which is a huge improvement. Similar experiments with ResNet-56 reveal that, even for compact networks, our method achieves competitive compression performance even without skipping any sensitive layers.
Optimizing a Multi-Layer Perceptron Based on an Improved Gray Wolf Algorithm to Identify Plant Diseases
Authors: Bi Chunguang , Tian Qiaoyun , Chen He , Meng Xianqiu , Wang Huan , Liu Wei , Jiang Jianhua
Published: July 2023

Metaheuristic optimization algorithms play a crucial role in optimization problems. However, the traditional identification methods have the following problems: (1) difficulties in nonlinear data processing; (2) high error rates caused by local stagnation; and (3) low classification rates resulting from premature convergence. This paper proposed a variant based on the gray wolf optimization algorithm (GWO) with chaotic disturbance, candidate migration, and attacking mechanisms, naming it the enhanced gray wolf optimizer (EGWO), to solve the problem of premature convergence and local stagnation. The performance of the EGWO was tested on IEEE CEC 2014 benchmark functions, and the results of the EGWO were compared with the performance of three GWO variants, five traditional and popular algorithms, and six recent algorithms. In addition, EGWO optimized the weights and biases of a multi-layer perceptron (MLP) and proposed an EGWO-MLP disease identification model; the model was tested on IEEE CEC 2014 benchmark functions, and EGWO-MLP was verified by UCI dataset including Tic-Tac-Toe, Heart, XOR, and Balloon datasets. The experimental results demonstrate that the proposed EGWO-MLP model can effectively avoid local optimization problems and premature convergence and provide a quasi-optimal solution for the optimization problem.
Cost of Ownership of Spare Parts under Uncertainty: Integrating Reliability and Costs
Authors: Durán Orlando , Afonso Paulo , Jiménez Víctor , Carvajal Katty
Published: July 2023

In capital-intensive organizations, decisions regarding capital costs play an important role due to the significant amount of investment required and the expected return on investment. Spare parts management is crucial to those ends, as spare parts management can constitute a significant portion of OPEX. Companies must implement a trade-off analysis between stock levels and assets’ availability. Decision-making supports mechanisms such as the Level of Repair Analysis (LORA), Integrated Logistics Systems (ILS), and life-cycle costing (LCC) models have been developed to aid in equipment selection, implementation, and decommissioning. Nowadays, these mechanisms appear to be integrated with risk-management models and standards. This paper proposes a long-term costing model that integrates a capacity analysis, reliability functions, and risk considerations for the cost management of logistics activities, particularly in MRO structures. The model is built upon Time-Driven Activity-Based Costing (TD-ABC) and incorporates the volume of activities generated by MRO needs. It also addresses uncertainty through the integration of a cost-at-risk model. By integrating spare parts, activity-based cost models, and risk measurement through Monte Carlo simulation, this study offers powerful insights into optimizing spare parts logistics activities. The proposed model is a novel approach to include the risk of cost in spare parts management, and its matrix-activity-based structure makes possible the development of sophisticated mathematical models for costing and optimization purposes in different domains.
Buckling of Cracked Euler–Bernoulli Columns Embedded in a Winkler Elastic Medium
Authors: Loya José Antonio , Santiuste Carlos , Aranda-Ruiz Josué , Zaera Ramón
Published: July 2023

This work analyses the buckling behaviour of cracked Euler–Bernoulli columns immersed in a Winkler elastic medium, obtaining their buckling loads. For this purpose, the beam is modelled as two segments connected in the cracked section by a mass-less rotational spring. Its rotation is proportional to the bending moment transmitted through the cracked section, considering the discontinuity of the rotation due to bending. The differential equations for the buckling behaviour are solved by applying the corresponding boundary conditions, as well as the compatibility and jump conditions of the cracked section. The proposed methodology allows calculating the buckling load as a function of the type of support, the parameter defining the elastic soil, the crack position and the initial length of the crack. The results obtained are compared with those published by other authors in works that deal with the problem in a partial way, showing the interaction and importance of the parameters considered in the buckling loads of the system.
Marine Biomaterials: Hyaluronan
Authors: Abdel-Rahman Rasha. M. , Abdel-Mohsen A. M.
Published: July 2023

The marine-derived hyaluronic acid and other natural biopolymers offer exciting possibilities in the field of biomaterials, providing sustainable and biocompatible alternatives to synthetic materials. Their unique properties and abundance in marine sources make them valuable resources for various biomedical and industrial applications. Due to high biocompatible features and participation in biological processes related to tissue healing, hyaluronic acid has become widely used in tissue engineering applications, especially in the wound healing process. The present review enlightens marine hyaluronan biomaterial providing its sources, extraction process, structures, chemical modifications, biological properties, and biocidal applications, especially for wound healing/dressing purposes. Meanwhile, we point out the future development of wound healing/dressing based on hyaluronan and its composites and potential challenges.
Carbohydrate-Containing Low Molecular Weight Metabolites of Microalgae
Authors: Stonik Valentin A. , Stonik Inna V.
Published: July 2023

Microalgae are abundant components of the biosphere rich in low molecular weight carbohydrate-containing natural products (glycoconjugates). Glycoconjugates take part in the processes of photosynthesis, provide producers with important biological molecules, influence other organisms and are known by their biological activities. Some of them, for example, glycosylated toxins and arsenicals, are detrimental and can be transferred via food chains into higher organisms, including humans. So far, the studies on a series of particular groups of microalgal glycoconjugates were not comprehensively discussed in special reviews. In this review, a special focus is given to glycoconjugates’ isolation, structure determination, properties and approaches to search for new bioactive metabolites. Analysis of literature data concerning structures, functions and biological activities of ribosylated arsenicals, galactosylated and sulfoquinovosylated lipids, phosphoglycolipids, glycoside derivatives of toxins, and other groups of glycoconjugates was carried out and discussed. Recent studies were fundamental in the discovery of a great variety of new carbohydrate-containing metabolites and their biological activities in defining the role of microalgal viral infections in regulating microalgal blooms as well as in the detection of glycoconjugates with potent immunomodulatory properties. Those discoveries support growing interest in these molecules.
Evaluation and Performance of a Positive Airway Pressure Device (CPAP-AirFlife™): A Randomized Crossover Non-Inferiority Clinical Study in Normal Subjects
Authors: Tinoco Héctor A. , Perdomo-Hurtado Luis , Henao-Cruz Joismer A. , Escobar-Serna José F. , Jaramillo-Robledo Oscar , Aguirre-Ospina Oscar D. , Hurtado-Hernández Mateo , Lopez-Guzman Juliana
Published: July 2023

Background and Objectives: During the COVID-19, the demand for non-invasive ventilatory support equipment significantly increased. In response, a novel non-invasive ventilatory support model called CPAP-AirFlife™ was developed utilizing existing technologies. This model offers technological advantages, including an aerosol-controlled helmet suitable for high-risk environments such as ambulances. Additionally, it is cost-effective and does not require medical air, making it accessible for implementation in low-level hospitals, particularly in rural areas. This study aimed to assess the efficacy of CPAP-AirFlife™ by conducting a non-inferiority comparison with conventional ventilation equipment used in the Intensive Care Unit. Materials and Methods: A clinical study was conducted on normal subjects in a randomized and sequential manner. Parameters such as hemoglobin oxygen saturation by pulse oximetry, exhaled PCO2 levels, vital signs, and individual tolerance were compared between the CPAP-AirFlife™ and conventional equipment. The study population was described in terms of demographic characteristics and included in the analysis. Results: It was shown that the CPAP-AirFlife™ was not inferior to conventional equipment in terms of efficacy or tolerability. Hemoglobin oxygen saturation levels, exhaled PCO2 levels, vital signs, and individual tolerance did not significantly differ between the two models. Conclusions: The findings suggest that CPAP-AirFlife™ is a practical and cost-effective alternative for non-invasive ventilatory support. Its technological advantages, including the aerosol-controlled helmet, make it suitable for high-risk environments. The device’s accessibility and affordability make it a promising solution for implementation in low-level hospitals, particularly in rural areas. This study supports using CPAP-AirFlife™ as a practical option for non-invasive ventilatory support, providing a valuable contribution to respiratory care during the COVID-19 pandemic and beyond.
Modern and Non-Invasive Methods of Fat Removal
Authors: Piłat Patrycja , Szpila Gabriela , Stojko Michał , Nocoń Jakub , Smolarczyk Joanna , Żmudka Karol , Moll Martyna , Hawranek Michał
Published: July 2023

Adipocytes accumulate triacylglycerols as an energy store, thereby causing an increase in the adipose tissue volume. Weight gain can be prevented through damage to the adipocyte structure or an increase in the body’s metabolic rate. Commonly used methods to disintegrate the cell membrane of adipocytes include injection lipolysis, cryolipolysis, ultrasonic lipolysis, radiofrequency lipolysis, laser lipolysis, carboxytherapy, and lipolysis using an electromagnetic field. The names of these methods suggest which substances are being used, and their main advantages are a very low invasiveness, as well as effectiveness. However, new discoveries in medicine, along with individuals’ desire to improve their appearance, have resulted in numerous studies on more ways of reducing body fat. Great potential is seen in beige adipocytes, which can be transformed, i.e., “recruited” from white adipocytes, or synthesized de novo; they also show thermogenic properties. One of the stimuli inducing the formation of beige adipocytes is cold and B3-adrenergic stimulation. Based on these findings, the researchers created, for example, cooling clothing. Additionally, curcumin and natural anthocyanins have proven to be helpful in the treatment of obesity and diabetes, by stimulating the secretion of glucagon-like peptide-1, and inducing the formation of beige adipocytes. Another study showed that the conversion of white adipose tissue is indirectly influenced by interleukin-6 secreted by the muscles, the expression of which is increased in people actively exercising. Moreover, there is potential in adenosine analogs, fenoldopam, rhubarb, the herbal extract Ephedra sinica Stapf, electroacupuncture simulation, and the drug CBL-514. Despite knowledge and experience, the ideal method for a quick and noticeable, but safe and non-invasive reduction of body fat has not been found yet. The research conducted nowadays may bring us closer to the development of a universal method, and turn out to be a breakthrough in the fight against overweight and obesity.
A Rare Case of Orbital Castleman Disease with Overlapping IgG4-Related Disease
Authors: Liu Li-Ching , Chen Yann-Guang , Liu Nien-Tzu , Chen Yi-Hao , Chien Ke-Hung
Published: July 2023

Multicentric Castleman disease (MCD) is a systemic lymphoproliferative disorder that can lead to mass lesions in various body parts, including the lungs, kidneys, and extranodal sites. Meanwhile, orbital Castleman disease is extremely rare. Immunoglobulin G4-related disease (IgG4-RD) is a recently recognized fibroinflammatory disorder and is characterized by the formation of tumor-like lesions with lymphoplasmacytic infiltrates, which are enriched in IgG4-positive plasma cells and may present with a characteristic storiform pattern of fibrosis to variable degrees. In this study, we report a case of a 67-year-old Taiwanese man with a 7-year history of bilateral eyelid swelling and proptosis. Orbital magnetic resonance imaging revealed soft tissue lesions in the bilateral intraconal region, demonstrating strong enhancement in the lacrimal glands, and extension into the bilateral infraorbital foramen, suggesting an orbital lymphoproliferative disease. The histopathological results of the intraorbital tumor excision were suggestive of a plasma-cell-predominant mixed-cell variant of MCD. However, the patient also showed definitive signs of IgG4-RD, including lacrimal gland enlargement and histopathological results of plasmacytosis, fibrosis, and germinal centers, with an increased ratio of IgG4 cells and elevated serum IgG4 levels. This case suggests a potential interacting pathway between these two disease entities that needs further studies.
Integration of Metabolome and Transcriptome Reveals the Major Metabolic Pathways and Potential Biomarkers in Response to Freeze-Stress Regulation in Apple (Malus domestica)
Authors: Yu Yifei , Wu YaJing , Liu Wenfei , Liu Jun , Li Ping
Published: July 2023

Freezing stress is the main factor affecting the normal growth and distribution of plants. The safe overwintering of a perennial deciduous plant is a crucial link to ensuring its survival and yield. However, little is known about the molecular mechanism of its gene regulation metabolites as related to its freeze-tolerance. In order to enhance our comprehension of freeze-tolerance metabolites and gene expression in dormant apple trees, we examined the metabolic and transcriptomic differences between ‘Ralls’ and ‘Fuji’, two apple varieties with varying degrees of resistance to freezing. The results of the freezing treatment showed that ‘Ralls’ had stronger freeze-tolerance than ‘Fuji’. We identified 302, 334, and 267 up-regulated differentially accumulated metabolites (DAMs) and 408, 387, and 497 down-regulated DAMs between ‘Ralls’ and ‘Fuji’ under −10, −15, and −20 °C treatment, respectively. A total of 359 shared metabolites were obtained in the upward trend modules, of which 62 metabolites were associated with 89 pathways. The number of up-regulated genes accounted for 50.2%, 45.6%, and 43.2% of the total number of differentially expressed genes (DEGs), respectively, at −10, −15, and −20 °C. Through combined transcriptome and metabolome analysis, we identified 12 pathways that included 16 DAMs and 65 DEGs. Meanwhile, we found that 20 DEGs were identified in the phenylpropanoid biosynthesis pathway and its related pathways, involving the metabolism of p-Coumaroyl-CoA, 7, 4′-Dihydroxyflavone, and scolymoside. These discoveries advance our comprehension of the molecular mechanism underlying apple freeze-tolerance and provide genetic material for breeding apple cultivars with enhanced freeze-tolerance.
Experimental Study on Critical Parameters Degradation of Nano PDSOI MOSFET under TDDB Stress
Authors: Gao Tianzhi , Yang Jianye , Liu Hongxia , Lu Yong , Liu Changjun
Published: July 2023

In today’s digital circuits, Si-based MOS devices have become the most widely used technology in medical, military, aerospace, and aviation due to their advantages of mature technology, high performance, and low cost. With the continuous integration of transistors, the characteristic size of MOSFETs is shrinking. Time-dependent dielectric electrical breakdown (TDDB) is still a key reliability problem of MOSFETs in recent years. Many researchers focus on the TDDB life of advanced devices and the mechanism of oxide damage, ignoring the impact of the TDDB effect on device parameters. Therefore, in this paper, the critical parameters of partially depleted silicon-on-insulator (PDSOI) under time-dependent dielectric electrical breakdown (TDDB) stress are studied. By applying the TDDB acceleration stress experiment, we obtained the degradation of the devices’ critical parameters including transfer characteristic curves, threshold voltage, off-state leakage current, and the TDDB lifetime. The results show that TDDB acceleration stress will lead to the accumulation of negative charge in the gate oxide. The negative charge affects the electric field distribution. The transfer curves of the devices are positively shifted, as is the threshold voltage. Comparing the experimental data of I/O and Core devices, we can conclude that the ultra-thin gate oxide device’s electrical characteristics are barely affected by the TDDB stress, while the opposite is true for a thick-gate oxide device.
Investigation on Wire Electrochemical Discharge Micro-Machining
Authors: Kong Weijing , Liu Ziyu , Zhang Rudong , Zeng Yongbin
Published: July 2023

With the development of MEMS, the machining demand and requirements for difficult-to-machine metal micro parts are getting higher. Microelectric discharge machining is an effective method to process difficult-to-machine metals. However, the recast layer caused by high temperatures in microelectric discharge machining affects the properties of machined materials. Here, we propose the wire electrochemical discharge micro-machining (WECDMM) and develop a new electrolyte system, which removes the recast layer. In this study, the mechanism of WECDMM was elucidated. The electrolyte was optimized through a comparison experiment, and NaNO3-glycol solution was determined as the best electrolyte. The influences of key process parameters including the conductivity of the electrolyte, pulse voltage, pulse-on time and wire feed rate were analyzed on the slit width, standard deviation, the radius of fillet at the entrance of the slit and roughness. Typical microstructures were machined, which verified the machining ability of WECDMM.