bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing Rural Tourism Experiences: What Can We Learn from the Azores Region?
Authors: Batista Maria da Graça , Castanho Rui Alexandre , Sousa Áurea , Couto Gualter , Pimentel Pedro
Published: June 2023

This research paper focused on tourists’ experiences after engaging in a rural tourism experience, the activities developed during that period, and the relevant factors they considered when planning the holidays. We collected data in the Azores, a region known to implement rural tourism. Therefore, the collected data were analyzed using mainly summary statistics, graphical representations, and exploratory data analysis methods, including the nonlinear (categorical) principal component analysis (CatPCA). The CatPCA’s objective is the same as that of the principal component analysis (PCA). We found that the landscape, adventure-related activities, and local gastronomy were some of the reasons tourists choose the Azores as a destination. The rural living experience and the local population’s welcoming traits were mentioned as factors that make tourists want to return to the Azores on holidays. Moreover, rural tourism in the Azores offers a unique opportunity to connect with the region’s rich cultural heritage. The islands have a long history shaped by centuries of settlement and the blending of various cultures, resulting in a distinct Azorean identity.
Coating of Layer-by-Layer Assembly Based on Chitosan and CMC: Emerging Alternative for Quality Maintenance of Citrus Fruit
Authors: Niu Chenyu , Liu Lingling , Farouk Amr , Chen Cunkun , Ban Zhaojun
Published: June 2023

Citrus fruits are susceptible to microbial infection during storage and transportation, leading to weight loss, quality deterioration and even physiological decay. In this study, a layer-by-layer (LbL) self-assembly edible coating based on chitosan and Sodium carboxymethyl cellulose (CMC) was prepared using electrostatic deposition. Postharvest citrus fruits (Citrus reticulate cv. ‘Chunxiang’) were coated either with the LbL coating, which exhibited an increased transmission rate of water vapor, or with single chitosan coating. The data of some physiological indexes of citrus coated with LbL coating and single coating were compared after being stored at 13 ± 2 °C and at relative humidity (RH) at 80–85% (shelf-life condition) for 10 days. Results demonstrated that the LbL deposited coating was effective at maintaining morphological and microstructural attributes, increasing the surface brightness, firmness and the content of titratable acid and ascorbic acid, as well as reducing the weight loss after storage by about 0.8%. Results in the present study indicated that the LbL edible coating could have the potential to maintain postharvest citrus quality during storage.
Stable Isotopic Evaluation of Recharge into a Karst Aquifer in a Glaciated Agricultural Region of Northeastern Wisconsin, USA
Authors: Luczaj John A. , Konrad Amber , Norfleet Mark , Schauer Andrew
Published: June 2023

Ground water contamination from septic systems and the application of dairy cattle manure has been a long-standing problem in rural northeastern Wisconsin, especially in areas with thin soils over karstified Silurian dolostone bedrock, where as many as 60% of the wells show evidence of fecal contamination. We present the results of a citizen science supported water-isotope study in Kewaunee County, Wisconsin to evaluate aquifer recharge processes in the critical zone and to demonstrate the viability of time-series stable isotope data as a supplement to traditional water quality indicators in a contamination-prone aquifer. A meteoric water line was also constructed for Green Bay, Wisconsin, providing reasonable isotopic ranges for aquifer recharge events. Volunteer homeowners collected water samples from their domestic wells for a period of ~14 months to provide a measure of long-term isotopic variation in produced water and to determine whether event-driven responses could be identified using δ18O and δ2H isotopic values. Three shallower wells with a prior history of contamination exhibited significant seasonal variation, while the deepest well with the greatest soil thickness (above bedrock) showed less variation. For moderate precipitation events, the shallowest well showed as much as 5–13% of produced water coming from direct recharge, with smaller contributions for deeper wells. Our case study provides a clear example of how citizen science can collect useful time-series isotopic data to support groundwater recharge studies.
Flexible Co(II)-and Ni(II)-Based Cationic 2D Metal–Organic Frameworks Based on a Charge-Neutral (O,O)-Donor Bridge
Authors: Demakov Pavel A. , Kovalenko Konstantin A. , Lavrov Alexander N. , Fedin Vladimir P.
Published: June 2023

Two new metal–organic frameworks based on highly flexible 1,4-diazabicyclo[2.2.2]octane N,N′-dioxide (odabco) ligands were successfully synthesized and characterized. Their crystallographic formulae are [M(DMF)2(odabco)2](ClO4)2·dioxane, where M2+ = Co2+ (1) and Ni2+ (2), and DMF is N,N-dimethylformamide. The title compounds possess cationic 2D coordination networks filled with perchlorate anions and dioxane solvent molecules in the interlayer space, with 20% solvent accessible volume. Carbon dioxide adsorption measurements for desolvated samples 1a and 2a gave 511 m2/g and 377 m2/g specific surface areas, respectively, revealing the first example of gas adsorption properties in the structure based on a flexible odabco bridge, despite the presence of large counteranions within the positively charged network. Magnetization measurements for 1, 1a, 2 and 2a reveal their paramagnetic nature to be in a reasonable agreement with crystal structures, and almost no solvent dependence of the magnetization characteristics. A decrease in the effective magnetic moment observed at low temperatures is attributed mostly to zero-field level-splitting in the octahedral Ni2+ and Co2+ ions.
A Review on the Fabrication and Mechanical Characterization of Fibrous Composites for Engineering Applications
Authors: Ashrith H. S. , Jeevan T. P. , Xu Jinyang
Published: June 2023

This review focuses on the fabrication and mechanical characterization of fibrous composites for engineering applications. Fibrous composites are materials composed of two or more distinct phases, with fibers embedded in a matrix. The properties of these materials depend on the properties of both the fibers and the matrix, as well as the way they are combined and fabricated. The various fabrication methods, along with the process parameters, used to manufacture synthetic and natural fibrous composites for engineering applications, including hand lay-up, compression molding, resin transfer molding, additive manufacturing, etc., are discussed. The mechanical characterization of fibrous composites, including their strength, stiffness, and toughness of both synthetic and natural fibrous composites are discussed. The advantages and disadvantages of fiber reinforcement are discussed, along with their influence on the resulting mechanical characteristics of the composites. It can be observed that the mechanical properties of fibrous composites can be tailored by controlling various factors, such as the fiber orientation, fiber volume fraction, and matrix type. Although fibrous composites offer significant advantages, several challenges hinder their widespread use in engineering applications. These challenges include high manufacturing costs, limited design guidelines, and difficulties in predicting their mechanical behavior under various loading conditions. Therefore, despite their unique properties, these challenges must be overcome for fibrous composites to realize their full potential as high-performance materials.
Effects of Gamma Radiation Doses on the AC Electrical Properties of Epoxy Reinforced with Nano-Silica Composites
Authors: Abusaleh Batool A. , Elimat Ziad M. , Alzubi Ruba I. , Juwhari Hassan K.
Published: June 2023

This study reports the effects of gamma radiation on the AC electrical properties of epoxy nano-silica composite sheets with an average thickness of 3 mm. Epoxy reinforced with different nano-silica concentrations of 0, 5, 10, and 15 wt.%. The epoxy nano-silica composites were exposed to different gamma radiation dosages of 1, 3, and 5 kGy. The data were analyzed before and after gamma irradiation and the results showed that the AC electrical properties of the gamma-irradiated epoxy nano-silica composites varied from those of the non-irradiated samples. We found that there were significant changes in the impedance, dielectric constant, dielectric loss, and AC electrical conductivity values of the epoxy nano-silica composites after irradiation, and the AC electrical conductivity and dielectric constant values of the nano-silica composites were enhanced by exposing the samples to gamma radiation because more free electrons were released inside the epoxy nano-silica composites. The AC electrical properties, such as impedance, dielectric constant, dielectric loss, and electrical conductivity, of the epoxy nano-silica composites were studied and discussed before and after gamma radiation with different dosages. We found that these AC electrical properties marginally increased with increasing doses of gamma irradiation.
A Robust Approach to Multimodal Deepfake Detection
Authors: Salvi Davide , Liu Honggu , Mandelli Sara , Bestagini Paolo , Zhou Wenbo , Zhang Weiming , Tubaro Stefano
Published: June 2023

The widespread use of deep learning techniques for creating realistic synthetic media, commonly known as deepfakes, poses a significant threat to individuals, organizations, and society. As the malicious use of these data could lead to unpleasant situations, it is becoming crucial to distinguish between authentic and fake media. Nonetheless, though deepfake generation systems can create convincing images and audio, they may struggle to maintain consistency across different data modalities, such as producing a realistic video sequence where both visual frames and speech are fake and consistent one with the other. Moreover, these systems may not accurately reproduce semantic and timely accurate aspects. All these elements can be exploited to perform a robust detection of fake content. In this paper, we propose a novel approach for detecting deepfake video sequences by leveraging data multimodality. Our method extracts audio-visual features from the input video over time and analyzes them using time-aware neural networks. We exploit both the video and audio modalities to leverage the inconsistencies between and within them, enhancing the final detection performance. The peculiarity of the proposed method is that we never train on multimodal deepfake data, but on disjoint monomodal datasets which contain visual-only or audio-only deepfakes. This frees us from leveraging multimodal datasets during training, which is desirable given their lack in the literature. Moreover, at test time, it allows to evaluate the robustness of our proposed detector on unseen multimodal deepfakes. We test different fusion techniques between data modalities and investigate which one leads to more robust predictions by the developed detectors. Our results indicate that a multimodal approach is more effective than a monomodal one, even if trained on disjoint monomodal datasets.
Characterization of Lung Inflammatory Response to Aspergillus fumigatus Spores
Authors: Bouyssi Alexandra , Déméautis Tanguy , Trecourt Alexis , Delles Marie , Agostini Fany , Monneret Guillaume , Glehen Olivier , Wallon Martine , Persat Florence , Devouassoux Gilles , Bentaher Abderrazzak , Menotti Jean
Published: June 2023

The airway exposure to Aspergillus fumigatus spores (AFsp) is associated with an inflammatory response, potentially leading to allergic and/or chronic pulmonary aspergillosis. The aim of our study is to better understand the host response, first in vitro, then in vivo, following the chronic exposure of mice to AFsp. We investigated the inflammatory response to AFsp in cell mono- and co-culture systems with murine macrophages and alveolar epithelial cells. The mice were subjected to two intranasal instillations using 105 AFsp. Their lungs were processed for inflammatory and histopathological analyses. In cell culture, the gene expressions significantly increased for TNF-α, CXCL-1, CXCL-2, IL-1β, IL-1α and GM-CSF in macrophages, with these increases being limited for TNF-α, CXCL-1 and IL-1α in epithelial cells. In co-culture, increases in the TNF-α, CXCL-2 and CXCL-1 gene expressions were observed to be associated with increased protein levels. The in vivo lung histological analyses of mice challenged by AFsp showed cellular infiltrates in the peribronchial and/or alveolar spaces. A Bio-Plex approach on the bronchoalveolar lavage revealed significant increases in the protein secretion of selected mediators of the challenged mice compared to the unchallenged mice. In conclusion, the exposure to AFsp resulted in a marked inflammatory response of macrophages and epithelial cells. These inflammatory findings were confirmed in mouse models associated with lung histologic changes.
Effects of Arbuscular Mycorrhizal Fungi on Robinia pseudoacacia L. Growing on Soils Contaminated with Heavy Metals
Authors: Zhao Liuhui , Yang Tao , Zhou Jinxing , Peng Xiawei
Published: June 2023

Arbuscular mycorrhizal fungi (AMF) have been shown to assist plants in increasing metal tolerance and accumulation in heavy metal (HM)-contaminated soils. Herein, a greenhouse pot experiment was conducted to assess the interactions of growth substrates (S1, S2, and S3, respectively) with various HM contamination and nutrient status sampling from a typical contaminated soil and tailings in Shuikoushan lead/zinc mining in Hunan province, China, and AMF inoculation obtained from plants in uncontaminated areas (Glomus mosseae, Glomus intraradices, and uninoculated, respectively) on the biomass and uptake of HMs and phosphorus (P) by the black locust plant (Robinia pseudoacacia L.). The results indicated that the inoculation with AMF significantly enhanced the mycorrhizal colonization of plant roots compared with the uninoculated treatments, and the colonization rates were found to be higher in S1 and S2 compared with S3, which were characterized with a higher nutrient availability and lead concentration. The biomass and heights of R. pseudoacacia were significantly increased by AMF inoculation in S1 and S2. Furthermore, AMF significantly increased the HM concentrations of the roots in S1 and S2 but decreased the HM concentrations in S3. Shoot HM concentrations varied in response to different AMF species and substrate types. Mycorrhizal colonization was found to be highly correlated with plant P concentrations and biomass in S1 and S2, but not in S3. Moreover, plant biomass was also significantly correlated with plant P concentrations in S1 and S2. Overall, these findings demonstrate the interactions of AMF inoculation and growth substrates on the phytoremediation potential of R. pseudoacacia and highlights the need to select optimal AMF isolates for their use in specific substrates for the remediation of HM-contaminated soil.
Investigating Functional Impairment in Chronic Low Back Pain: A Qualitative Study from the Patients and Specialists’ Perspectives
Authors: Cuomo Arturo , Marinangeli Franco , Magni Alberto , Petrucci Emiliano , Vittori Alessandro , Cascella Marco
Published: June 2023

Prompt and appropriate treatment of chronic low back pain (cLBP) is of the utmost importance for preventing relevant disability, high burden of disease, and increasing costs for the healthcare system. Recently, the concept of functional impairment has been associated with any type of chronic pain, and mounting attention has been paid to extending the aims of treatment beyond mere pain remission, including restoration of working capacity, everyday functioning, mobility, and quality of life. Nevertheless, a shared definition of functionality is still lacking. Notably, different specialists involved in the treatment of cLBP such as general practitioners, orthopedists, pain therapists, and physiatrists, and patients themselves have different opinions on what “functional impairment” actually means. On these premises, a qualitative interview study was performed to investigate how the concept of “functionality” is interpreted by different specialists involved in the management of cLBP, and by patients. Overall, all different specialists agreed that functionality should be assessed in clinical practice. However, in spite of several instruments available for evaluating functionality, no homogeneity of behavior is observable.
Video Consensus and Radical Prostatectomy: The Way to Chase the Future?
Authors: Esperto Francesco , Cacciatore Loris , Tedesco Francesco , Brassetti Aldo , Testa Antonio , Raso Gianluigi , Iannuzzi Andrea , Papalia Rocco , Scarpa Roberto Mario
Published: June 2023

In the age of information, new platforms are consulted by patients to acquire consciousness about medical treatments. The aim of this study was to assess the level of understanding and feasibility of video consensus (VC) administration in patients scheduled for radical prostatectomy (RP), comparing it with standard informed consensus (SIC). According to the European Association of Urology Patient Information, we set up a video content for RP that was translated in Italian and implemented with information about possible perioperative and postoperative complications, days of hospitalization etc. From 2021 to 2022, all patients undergoing RP at our institution were prospectively included in this study. Patients received an SIC and after that, a VC about RP. After two consensuses were administered, patients received a preformed Likert 10 scale and STAI questionnaires. On the RP dataset, 276 patients were selected and 552 questionnaires for both SIC and VC were evaluated. Out of these, the median age was 62 years (IQR 60–65). Patients reported a higher overall satisfaction for VC (8.8/10) compared to the traditional informed consent (6.9/10). Therefore, VC may play a role in the future of surgery, improving the consciousness and satisfaction of patients and reducing preoperative anxiety.
“Location, Location, Location”: Fluctuations in Real Estate Market Values after COVID-19 and the War in Ukraine Based on Econometric and Spatial Analysis, Random Forest, and Multivariate Regression
Authors: Gabrielli Laura , Ruggeri Aurora Greta , Scarpa Massimiliano
Published: June 2023

In this research, the authors aim to detect the marginal appreciation of construction and neighbourhood characteristics of property prices at three different time points: before the COVID-19 pandemic, two years after the first COVID-19 alert but before the War in Ukraine, and one year after the outbreak of the War. The marginal appreciations of the building’s features are analysed for a pilot case study in Northern Italy using a Random Forest feature importance analysis and a Multivariate Regression. Several techniques are integrated into this study, such as computer programming in Python language, multi-parametric value assessment techniques, feature selection procedures, and spatial analysis. The results may represent an interesting ongoing monitoring of how these anomalous events affect the buyer’s willingness to pay for specific characteristics of the buildings, with particular attention to the location features of the neighbourhood and accessibility.
Evidence of Global Convergence: Perspectives for Economic and Territory Planning in Times of the COVID-19 Pandemic
Authors: Martinho Vítor João Pereira Domingues
Published: June 2023

Governments and international organizations have implemented efforts to promote the convergence of socioeconomic indicators between countries. The structural funds adopted by the European Union institutions are examples of policy instruments implemented to promote convergence in the GDP (gross domestic product) among the member states. Nonetheless, these policy measures are dependent on several internal and external factors, making these efforts vulnerable to exogenous shocks such as those associated with the global financial crisis and the COVID-19 pandemic. From this perspective, this research aims to analyze the convergence trends over the last few years and assess the respective implications of the pandemic on this framework. For that, statistical information from the World Bank for the GDP per capita was considered for the period 2006–2021 for all countries and organized for each group of levels of income and each world region. These data were analyzed through panel data approaches, considering the developments in convergence theory. The results show that the signs of convergence are different for each level of income and each region, highlighting the idea of clubs of convergence. On the other hand, the pandemic disturbed the trends of convergence verified worldwide, but nonetheless, it seems to be on a smaller scale than the global financial crisis. In any case, these findings should be confirmed in future research with more recent data.
The Dark Side of Nosocomial Infections in Critically Ill COVID-19 Patients
Authors: Biondo Carmelo , Ponzo Elena , Midiri Angelina , Ostone Giuseppe Bernardo , Mancuso Giuseppe
Published: June 2023

Coronavirus disease 2019 (COVID-19) is a potentially serious acute respiratory infection caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Since the World Health Organization (WHO) declared COVID-19 a global pandemic, the virus has spread to more than 200 countries with more than 500 million cases and more than 6 million deaths reported globally. It has long been known that viral respiratory tract infections predispose patients to bacterial infections and that these co-infections often have an unfavourable clinical outcome. Moreover, nosocomial infections, also known as healthcare-associated infections (HAIs), are those infections that are absent at the time of admission and acquired after hospitalization. However, the impact of coinfections or secondary infections on the progression of COVID-19 disease and its lethal outcome is still debated. The aim of this review was to assess the literature on the incidence of bacterial co-infections and superinfections in patients with COVID-19. The review also highlights the importance of the rational use of antibiotics in patients with COVID-19 and the need to implement antimicrobial stewardship principles to prevent the transmission of drug-resistant organisms in healthcare settings. Finally, alternative antimicrobial agents to counter the emergence of multidrug-resistant bacteria causing healthcare-associated infections in COVID-19 patients will also be discussed.
Synthesis, Spectroscopic, and Thermal Analyses of 2-Oxo-1,2-dihydroquinolin-8-yl 4-chlorobenzoate
Authors: Becerra Diana , Rojas Hugo , Castillo Juan-Carlos
Published: June 2023

The 2-oxo-1,2-dihydroquinolin-8-yl 4-chlorobenzoate was synthesized in good yield using a triethylamine-mediated O-acylation reaction between 8-hydroxyquinolin-2(1H)-one and 4-chlorobenzoyl chloride in acetonitrile at room temperature. This methodology is notable for its clean reaction profile and straightforward procedure. The 2-oxoquinoline derivative was characterized using spectroscopic, spectrometric, and thermal analyses, enabling a comprehensive understanding of its molecular structure and thermal properties.
Microstructures and Mechanical Properties of Al-Zn-Mg-Cu Alloys under Multi-Directional Severe Strain and Aging
Authors: Wei Chunhua , Lei Zhixin , Du Sijie , Chen Rongyou , Yin Yutang , Niu Chenglin , Xu Zhengbing
Published: June 2023

Microstructure is a significant factor that influences the mechanical properties of alloys. The effect of multiaxial forging (MAF) and subsequent aging treatment on the precipitated phases of Al-Zn-Mg-Cu alloy remains unclear. Therefore, an Al-Zn-Mg-Cu alloy was processed by means of solid solution and aging treatment, and MAF and aging treatment in this work, and the composition and distribution of precipitated phases were characterized in detail. The MAF results for dislocation multiplication and grain refinement were found. The high density of dislocation greatly accelerates the nucleation and growth of precipitated phases. Thus, the GP-zones almost transform into precipitated phases during subsequent aging. The MAF and aging alloy has more precipitated phases than the solid solution and aging treated alloy. The precipitates on the grain boundary are coarse and discontinuously distributed due to dislocation and grain boundary promoting the nucleation, growth and coarsening of the precipitates. The hardness, strength, ductility and microstructures of the alloy have been studied. Without compromising the ductility much, the MAF and aging alloy has higher hardness and strength, with values of 202 HV and 606 MPa, respectively, and an appreciable ductility of 16.2%.
Reassessment of the Matrix Composition of Co-Re-Cr-Based Alloys for Particle Strengthening in High-Temperature Applications and Investigation of Suitable MC-Carbides
Authors: Seif Eugen , Rösler Joachim
Published: June 2023

This study reassesses the optimum matrix composition of Co-Re-Cr-based alloys for strengthening by MC-type carbides. It is found that the composition of Co-15Re-5Cr is ideally suited for this purpose as it allows the solution of the carbide-forming elements such as Ta, Ti, Hf, and C within a matrix consisting entirely of fcc-phase (typically at 1450 °C), having a high solubility for these elements, while precipitation heat treatment (typically at 900–1100 °C) occurs in a hcp-Co matrix, displaying a much lower solubility. In the case of the monocarbides TiC and HfC, this was investigated and achieved for the first time in Co-Re-based alloys. TaC and TiC emerged as suitable particles in Co-Re-Cr alloys for creep applications due to a large population of nano-sized particle precipitation, which is not the case for the mainly coarse HfC. Both Co-15Re-5Cr-xTa-xC and Co-15Re-5Cr-xTi-xC exhibit a formerly unknown maximum solubility close to x = 1.8 at.%. Therefore, further research on the particle-strengthening effect and the governing creep mechanisms of carbide-strengthened Co-Re-Cr alloys should focus on alloys with the following compositions: Co-15Re-5Cr-1.8Ta-1.8C and Co-15Re-5Cr-1.8Ti-1.8C
Insight into the Latest Medical Applications of Nanocellulose
Authors: Ghilan Alina , Nicu Raluca , Ciolacu Diana E. , Ciolacu Florin
Published: June 2023

Nanocelluloses (NCs) are appealing nanomaterials that have experienced rapid development in recent years, with great potential in the biomedical field. This trend aligns with the increasing demand for sustainable materials, which will contribute both to an improvement in wellbeing and an extension of human life, and with the demand to keep up with advances in medical technology. In recent years, due to the diversity of their physical and biological properties and the possibility of tuning them according to the desired goal, these nanomaterials represent a point of maximum interest in the medical field. Applications such as tissue engineering, drug delivery, wound dressing, medical implants or those in cardiovascular health are some of the applications in which NCs have been successfully used. This review presents insight into the latest medical applications of NCs, in the forms of cellulose nanocrystals (CNCs), cellulose nanofibers (CNFs) and bacterial nanocellulose (BNC), with an emphasis on the domains that have recently experienced remarkable growth, namely wound dressing, tissue engineering and drug delivery. In order to highlight only the most recent achievements, the presented information is focused on studies from the last 3 years. Approaches to the preparation of NCs are discussed either by top-down (chemical or mechanical degradation) or by bottom-up (biosynthesis) techniques, along with their morphological characterization and unique properties, such as mechanical and biological properties. Finally, the main challenges, limitations and future research directions of NCs are identified in a sustained effort to identify their effective use in biomedical fields.
The Effects of Tricalcium-Silicate-Nanoparticle-Containing Cement: In Vitro and In Vivo Studies
Authors: Ezawa Naho , Akashi Yoshihiko , Nakajima Kei , Kokubun Katsutoshi , Furusawa Masahiro , Matsuzaka Kenichi
Published: June 2023

A tricalcium-silicate-nanoparticle-containing cement (Biodentine) was developed to overcome the disadvantages of existing mineral trioxide aggregate (MTA) dental materials. This study aimed at evaluating the effects of Biodentine on the osteogenic differentiation of human periodontal ligament fibroblasts (HPLFs) in vitro and the healing of furcal perforations created experimentally in rat molars in vivo, in comparison to MTA. The in vitro studies performed the following assays: pH measurement using a pH meter, the release of calcium ions using a calcium assay kit, cell attachment and morphology using SEM, cell proliferation using a coulter counter, marker expression using quantitative reverse transcription polymerase chain reaction (qRT-PCR) and cell mineralized deposit formation using Alizarin Red S (ARS) staining. In the in vivo studies, MTA and Biodentine were used to fill the rat molar perforations. Rat molars were processed at 7, 14 and 28 days for analysis of inflammatory processes using hematoxylin and eosin (HE) staining, immunohistochemical staining of Runx2 and tartrate-resistant acid phosphate (TRAP) staining. The results demonstrate that the nanoparticle size distribution of Biodentine is critical for osteogenic potential at an earlier stage compared to MTA. Further studies are required to elucidate the mechanism of action of Biodentine in osteogenic differentiation.
Measurement and In-Depth Analysis of Higher Harmonic Generation in Aluminum Alloys with Consideration of Source Nonlinearity
Authors: Jeong Hyunjo , Shin Hyojeong , Zhang Shuzeng , Li Xiongbing
Published: June 2023

Harmonic generation measurement is recognized as a promising tool for inspecting material state or micro-damage and is an ongoing research topic. Second harmonic generation is most frequently employed and provides the quadratic nonlinearity parameter (β) that is calculated by the measurement of fundamental and second harmonic amplitudes. The cubic nonlinearity parameter (β2), which dominates the third harmonic amplitude and is obtained by third harmonic generation, is often used as a more sensitive parameter in many applications. This paper presents a detailed procedure for determining the correct β2 of ductile polycrystalline metal samples such as aluminum alloys when there exists source nonlinearity. The procedure includes receiver calibration, diffraction, and attenuation correction and, more importantly, source nonlinearity correction for third harmonic amplitudes. The effect of these corrections on the measurement of β2 is presented for aluminum specimens of various thicknesses at various input power levels. By correcting the source nonlinearity of the third harmonic and further verifying the approximate relationship between the cubic nonlinearity parameter and the square of the quadratic nonlinearity parameter (β∗β), β2≈β∗β, the cubic nonlinearity parameters could be accurately determined even with thinner samples and lower input voltages.
Experimental Study on Compressive and Flexural Performance of Lightweight Cement-Based Composites Reinforced with Hybrid Short Fibers
Authors: Dang Cong-Thuat , Pham My , Dinh Ngoc-Hieu
Published: June 2023

This paper aims to experimentally study the compressive and flexural characteristics of cement-based composites developed for fabricating thin, lightweight, and high-performance components of buildings. Expanded hollow glass particles with a 0.25–0.5 mm particle size were used as lightweight fillers. Hybrid fibers made of amorphous metallic (AM) and nylon fibers were used to reinforce the matrix with a total volume fraction of 1.5%. The primary test parameters included the expanded glass-to-binder (EG/B) ratio, the fiber volume content ratio, and the length of the nylon fibers in the hybrid system. The experimental results demonstrate that the EG/B ratio and the volume dosage of the nylon fibers exhibited insignificant effects on the compressive strength of the composites. Additionally, the utilization of nylon fibers with a longer length of 12 mm resulted in a slight compressive strength reduction of approximately 13% compared to that of the 6 mm nylon fibers. Further, the EG/G ratio exhibited an insignificant effect on the flexural behavior of lightweight cement-based composites in terms of their initial stiffness, strength, and ductility. Meanwhile, the increasing AM fiber volume fraction in the hybrid system from 0.25% to 0.5% and 1.0% improved flexural toughness by 42.8% and 57.2%, respectively. In addition, the nylon fiber length significantly affected the deformation capacity at the peak load and the residual strength in the post-peak stage.
Use of Geopolymer and Carbon Fiber-Reinforced Polymer for Repairing Reinforced Concrete Deck Soffit
Authors: Li Yeou-Fong , Hao Guo-Wei , Syu Jin-Yuan , Chen Bian-Yu , Lee Wei-Hao , Tsai Ying-Kuan
Published: June 2023

This study aimed to assess the feasibility of utilizing geopolymer for repairing reinforced concrete beams. Three types of beam specimens were fabricated: benchmark specimens without any grooves, rectangular-grooved beams, and square-grooved beams. The repair materials employed included geopolymer material, and epoxy resin mortar, while carbon fiber sheets were used as reinforcement in select cases. The repair materials were applied to the rectangular and square-grooved specimens, with the carbon fiber sheets attached to the tension side of the specimens. To evaluate the flexural strength of the concrete specimens, a third-point loading test was conducted. The test results indicated that the geopolymer exhibited higher compressive strength and shrinkage rate compared to the epoxy resin mortar. Furthermore, the specimens reinforced with carbon fiber sheets demonstrated even greater strength than the benchmark specimens. In terms of flexural strength under cyclic third-point loading tests, the carbon fiber-reinforced specimens exhibited the ability to withstand over 200 cycles of repeated loading at 0.8 times the ultimate load. In contrast, the benchmark specimens could only withstand seven cycles. These findings highlight that the use of carbon fiber sheets not only enhances compressive strength but also improves resistance to cyclic loading.
Speed Regulation and Optimization of Sensorless System of Permanent Magnet Synchronous Motor
Authors: Zhang Yan , Lu Huacai , Li Minghu , Liu Xiang
Published: June 2023

Aiming at the problems of speed overshoot, slow convergence and poor anti-interference in the control of permanent-magnet synchronous motors (PMSMs) without a position sensor, a pulse vibration high-frequency signal injection method for a permanent-magnet synchronous motor with an improved sliding mode control was designed. Firstly, the improved approach rate function is combined with the improved non-singular fast terminal sliding mode surface to design the non-singular fast terminal sliding mode controller (NFTSMC), which is used in the speed loop to improve the speed convergence ability and reduce its overshoot. Secondly, in order to eliminate the influence of the band-pass filter on the system bandwidth in the traditional high-frequency injection method, a pulse vibration high-frequency signal injection method that injects high-frequency voltage signals and synchronous current signals into the d^ axis of the estimated two-phase rotation coordinate system d^q^ and the αβ axis of the two-phase stationary coordinate system αβ was designed to estimate the motor position and speed to achieve sensorless control. Finally, the above control strategy was compared with the speed loop PI and the traditional sliding mode controller (SMC) of the speed loop, respectively. The simulation and experimental results show that whether it is a no-load variable speed or fixed speed loading, the above control strategy can effectively reduce the speed overshoot, accelerate the speed convergence and improve the load capacity of the system.
Determination of the Magnetic Intermediate Permeability of Special Materials Based on FEM-Simulation and Hall-Sensor Measurement
Authors: Denk Frank , Hofbauer Tobias
Published: June 2023

This document presents the process flow and the experimental conditions for calculating the static magnetic intermediate permeability of a specimen with a dedicated geometrical contour and surface for simulation parameter of metal detection systems. In this case, intermediate is explained and defined as probes with a magnetic permeability between 10 and 1000. An analysis of recent and current measurement standards as well as similar simulation principles leads to the contribution value of this new hybrid process flow. To calculate the permeability value in a first step, an electromagnetic circuit was constructed and excited with a defined electrical DC current with a dedicated tolerance for generating a static approximated homogenic magnetic field in a defined air gap space sector. Additionally, to the H-field generation part double copper coil, two magnetic ferrite cylinders with known permeability were used. The electrical and magnetic circuit has been modeled by an Ansys FEM Electronic Desktop software; the solver is magnetic static. Specifically, the simulated magnetic field distribution of the airgap was evaluated by using different Hall sensor elements with different tolerances. Subsequently, the electromagnetic circuit was expanded by implementing different cylindrical and cube shaped probes on a defined position inside the air gap sector with homogenic magnetization. Moreover, based on the analysis of the air gap structure without the probes, a detailed 3D-FEM model of the air gap magnetic field with special probes was established, which provides the environmental field distribution of the probes. The simulation models were compared with the corresponding Hall sensor measurements, which proved the high accuracy experimental validity of the models established in this paper. Finally, some key features related to parameter variations in the electromagnetic circuit were extracted, which can significantly reflect the characteristics of the robustness of the measurement principle. The main findings reported in this paper will be beneficial for magnetic parameter settings in electromagnetic simulation.
Global Boundedness in a Logarithmic Keller–Segel System
Authors: Liu Jinyang , Tian Boping , Wang Deqi , Tang Jiaxin , Wu Yujin
Published: June 2023

In this paper, we propose a user-friendly integral inequality to study the coupled parabolic chemotaxis system with singular sensitivity under the Neumann boundary condition. Under a low diffusion rate, the classical solution of this system is uniformly bounded. Our proof replies on the construction of the energy functional containing ∫Ω|v|4v2 with v>0. It is noteworthy that the inequality used in the paper may be applied to study other chemotaxis systems.
Axiomatic Foundations of Anisotropy-Based and Spectral Entropy Analysis: A Comparative Study
Authors: Boichenko Victor A. , Belov Alexey A. , Andrianova Olga G.
Published: June 2023

An axiomatic development of control systems theory can systematize important concepts. The current research article is dedicated to the investigation and comparison of two axiomatic approaches to the analysis of discrete linear time-invariant systems affected by external random disturbances. The main goal of this paper is to explore axiomatics of an anisotropy-based theory in comparison with axiomatics of a spectral entropy approach in detail. It is demonstrated that the use of the spectral entropy approach is mathematically rigorous, which allows one to prove that the minimal disturbance attenuation level in terms of an anisotropy-based control theory provides the desired performance that is not only for ergodic signals. As a result, axiomatics of the spectral entropy approach allows one to rigorously prove that anisotropy-based controllers can be used to guarantee the desired disturbance attenuation level, not only for stationary random sequences, but also for a wider set of input random signals.
Real-Time Trajectory Planning for Hypersonic Entry Using Adaptive Non-Uniform Discretization and Convex Optimization
Authors: Ma Jiarui , Chen Hongbo , Wang Jinbo , Zhang Qiliang
Published: June 2023

This paper introduces an improved sequential convex programming algorithm using adaptive non-uniform discretization for the hypersonic entry problem. In order to ensure real-time performance, an inverse-free precise discretization based on first-order hold discretization is adopted to obtain a high-accuracy solution with fewer temporal nodes, which would lead to constraint violation between the temporal nodes due to the sparse time grid. To deal with this limitation, an adaptive non-uniform discretization is developed, which provides a search direction for purposeful clustering of discrete points by adding penalty terms in the problem construction process. Numerical results show that the proposed method has fast convergence with high accuracy while all the path constraints are satisfied over the time horizon, thus giving potential to real-time trajectory planning.
Optimization of Asset and Liability Management of Banks with Minimum Possible Changes
Authors: Peykani Pejman , Sargolzaei Mostafa , Botshekan Mohammad Hashem , Oprean-Stan Camelia , Takaloo Amir
Published: June 2023

Asset-Liability Management (ALM) of banks is defined as simultaneous planning of all bank assets and liabilities under different conditions and its purpose is to maximize profits and minimize the risks in banks by optimizing the parameters in the balance sheet. Most of the studies `and proposed models in the ALM field are based on an objective function that maximizes bank profit. It is not easy to apply changes in these models in order to reach the optimal values of the parameters in the balance sheet. In this article, an attempt has been made to propose a linear model using constraints to achieve optimal values of balance sheet parameters using ALM objectives and considering balance sheet, system and regulatory constraints. It has also been tried to design the model according to the most possible mode and with the least changes and to minimize the size of the balance sheet. The analysis of the model presented in this article has been conducted using the parameters of the balance sheet and income statement of one of the famous Iranian banks. The results obtained from the proposed model show that the values of cash and receivables from banks and other credit institutions have decreased by 30% and increased by 200%, respectively, compared to the actual values of these parameters. Also, Total Income, Operating Income and Non-Operating Income have grown by 30% compared to the actual values of these parameters. Also, the values of a number of parameters are estimated to be zero after optimization. According to the results, it is obvious that the performance of bank managers, especially in the management of bank assets, is significantly different from the optimal values of the balance sheet, and the results obtained from the proposed model can help the management of banks as much as possible.
Safety and Efficacy of Corneal Cross-Linking in Patients Affected by Keratoconus: Long-Term Results
Authors: Knutsson Karl Anders , Genovese Paola Noemi , Paganoni Giorgio , Ambrosio Oriella , Ferrari Giulio , Zennato Arianna , Caccia Michela , Cataldo Madeleine , Rama Paolo
Published: June 2023

The present study evaluated the effectiveness and safety of corneal collagen cross-linking (CXL). A total of 886 eyes with progressive keratoconus were enrolled in a retrospective cohort study in a tertiary care university hospital. CXL was performed using a standard epithelium-off Dresden protocol. Visual outcomes, maximum keratometry (Kmax), demarcation line measurements, and complications were recorded. Visual outcomes and keratometric data were analyzed in a subgroup comprising 610 eyes. Uncorrected distance visual acuity (UDVA) improved from 0.49 ± 0.38 LogMAR to 0.47 ± 0.39 LogMAR (p = 0.03, n = 610) three years after the procedure, while corrected distance visual acuity (CDVA) improved from 0.15 ± 0.14 LogMAR to 0.14 ± 0.15 LogMAR (p = 0.007, n = 610). A significant reduction of Kmax from 56.28 ± 6.10 to 54.98 ± 6.19 (p < 0.001, n = 610) was observed three years after CXL. In five eyes (0.82%, 5/610) keratoconus progression continued after CXL. Three eyes were retreated successfully with documented refractive and topographic stability after five years. In the 35 eyes that completed 10 years of follow-up, mean visual acuity and topographic parameters remained stable. In conclusion, CXL is a safe and effective treatment for avoiding keratoconus progression. Long-term data are encouraging, supporting a high safety profile for this procedure.
Conformational State of Fenamates at the Membrane Interface: A MAS NOESY Study
Authors: Khodov Ilya A. , Belov Konstantin V. , Huster Daniel , Scheidt Holger A.
Published: June 2023

The present work analyzes the 1H NOESY MAS NMR spectra of three fenamates (mefenamic, tolfenamic, and flufenamic acids) localized in the lipid–water interface of phosphatidyloleoylphosphatidylcholine (POPC) membranes. The observed cross-peaks in the two-dimensional NMR spectra characterized intramolecular proximities between the hydrogen atoms of the fenamates as well as intermolecular interactions between the fenamates and POPC molecules. The peak amplitude normalization for an improved cross-relaxation (PANIC) approach, the isolated spin-pair approximation (ISPA) model, and the two-position exchange model were used to calculate the interproton distances indicative of specific conformations of the fenamates. The results showed that the proportions of the A+C and B+D conformer groups of mefenamic and tolfenamic acids in the presence of POPC were comparable within the experimental error and amounted to 47.8%/52.2% and 47.7%/52.3%, respectively. In contrast, these proportions for the flufenamic acid conformers differed and amounted to 56.6%/43.4%. This allowed us to conclude that when they bind to the POPC model lipid membrane, fenamate molecules change their conformational equilibria.
Saline Retention and Permeability of Nanofiltration Membranes Versus Resistance and Capacitance as Obtained from Impedance Spectroscopy under a Concentration Gradient
Authors: Pérez Miguel-Ángel , Gallego Silvia , Palacio Laura , Hernández Antonio , Prádanos Pedro , Carmona Francisco Javier
Published: June 2023

Impedance spectroscopy has been widely used for the study of the electrical properties of membranes for their characterization. The most common use of this technique is the measure of the conductivity of different electrolyte solutions to study the behavior and movement of electrically charged particles inside the pores of membranes. The objective of this investigation was to observe if there is a relation present between the retention that a nanofiltration membrane possesses to certain electrolytic solutions (NaCl, KCl, MgCl2, CaCl2, and Na2SO4) and the parameters that are obtained through IS measurements of the active layer of the membrane. To achieve our objective, different characterization techniques were performed to obtain the permeability, retention, and zeta potential values of a Desal-HL nanofiltration membrane. Impedance spectroscopy measurements were performed when a gradient concentration was present between both sides of the membrane to study the variation that the electrical parameters had with the time evolution.